Note: Descriptions are shown in the official language in which they were submitted.
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79735-11D1
IMMUNOSUPPRESSIVE POLYPEPTIDES AND NUCLEIC ACIDS
CROSS-REFERENCES TO RELATED APPLICATIONS
This is a divisional application of Canadian Patent Application Serial No.
2,703,263, filed
on October 15, 2008.
This application claims priority to and benefit of U.S. Provisional Patent
Application
Serial No. 60/984,631, filed on November 1, 2007, and U.S. Provisional Patent
Application Serial
No. 61/051,215, filed on May 7, 2008.
COPYRIGHT NOTIFICATION
Pursuant to 37 C.F.R. 1.71(e), Applicants note that a portion of this
disclosure contains
material which is subject to copyright protection. The copyright owner has no
objection to the facsimile
reproduction by anyone of the patent document or patent disclosure, as it
appears in the Patent and
Trademark Office patent file or records, but otherwise reserves all copyright
rights whatsoever.
FIELD OF THE INVENTION
This invention relates generally to novel polypeptides that bind CD80 and/or
CD86,
nucleic acid encoding such polypeptides, and methods of making and using such
polypeptides and nucleic
acids. Specifically, the subject matter of this divisional application relates
to CTLA-4 polypeptide of
SEQ ID NO:50 and related polypeptides such as recombinant fusion protein
dimers thereof, sequence
variants thereof, and nucleic acids encoding the polypeptides, fusions and
variants. It should be understood
that the expression -the invention" or the like encompasses the subject matter
of both the parent and this
divisional application.
BACKGROUND OF THE INVENTION
T cells play a major role in the initiation and regulation of immune
responses. For
complete activation of T cells to occur, at least two distinct signaling
events are required. A first signal is
produced by the interaction of T cell receptors (TCR) expressed on T cells
with specific antigens (Ag)
presented in the context of major histocompatibility complex (MHC) molecules
expressed on antigen-
presenting cells (APCs). A second (co-stimulation) signal results from the
interaction between
co-stimulatory ligands expressed on APCs and their corresponding receptors
expressed on T cells.
A dominant co-stimulation pathway involves the interaction between the CD80
(B7-1 or B7.1) and
CD86 (B7-2 or B7.2) ligands expressed on APCs with CD28 and CTLA-4 (also known
as CD152)
expressed mainly on T cells. CTLA-4 (cytotoxic 1-lymphocyte antigen 4) and
CD28 serve as receptors for
the CD80 and CD86 ligands.
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Positive signaling is mediated through the CD28 receptor. Binding of the CD80
and/or CD86 ligand(s) to CD28 lowers the threshold of T cell activation by
promoting the
formation of immunological synapses (Viola A. et al., Science 283:680-682
(1999)).
Additionally, CD28 co-stimulation activates or enhances the production of
factors central
to T cell proliferation and survival, such as interleukin-2 (IL-2), NF-KB, and
Bc1-XL
(Norton S. D. et at., J. Immunol. 149:1556-1561 (1992); Vella A. T. et al., J.
Immunol.
158: 4714-4720 (1997)). In vivo, CD28-deficient mice are severely
immunocompromised
and show poor antigen-specific T cell responses (Green, J. M. etal., Immunity
1:501-508
(1994)). T cell anergy or tolerance may result when T cells are activated in
the absence of
the costimulatory signal.
Negative signaling is mediated through the CTLA-4 receptor. The CD80 and
CD86 ligands each bind with high avidity to CTLA-4 and counterbalance
immunoproliferative responses derived from CD28 signaling. Potential
mechanisms of
CTLA-4 signaling include competitive binding of co-stimulatory molecules
CD80/CD86
(Masteller, E. M. et al., J. Immunol. 164:5319 (2000)), inhibition of TCR
signaling by
induction of phosphatases to the immunosynapse (Lee K. M. et al., Science
282:2263
(1998)), and disruption of the immunological synapse (Pentcheva-Hoang T. et
al.,
Immunity 21:401 (2004); Chikuma S. et al., J. Exp. Med 197:129 (2003);
Schneider H. et
al., Science 313: 1972 (2006)). In vivo, CTLA-4 deficient mice show profound
autoimmune phenotypes characterized by massive tissue infiltration and organ
destruction
(Waterhouse P. et al., Science 270:985 (1995)).
Therapeutic agents designed to antagonize the CD80/CD86 co-stimulation
pathway, such as soluble human CTLA-4-Ig, hold promise for the treatment of
autoirnmune diseases and disorders. The present invention provides
advantageous
molecules having improved abilities to modulate or suppress signaling through
the
CD80/CD86 co-stimulation pathway and methods of using such molecules for
selected
and differential manipulation of T cell responses. Such molecules are of
beneficial use in
a variety of applications as discussed in detail below.
SUMMARY OF THE INVENTION
In a first aspect, the invention provides an isolated or recombinant CTLA-4
polypeptide comprising a polypeptide sequence which differs from the
polypeptide
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sequence of the extracellular domain of human CTLA-4 shown in SEQ ID NO:159 in
up
to 15 amino acid residues, wherein the isolated or recombinant CTLA-4
polypeptide has
an ability to bind CD80 or CD86 or an extracellular domain of either and/or
has an ability
to suppress or inhibit an immune response.
A polypeptide according to the first aspect of the invention may have at least
90%
sequence identity, or at least 95%, at least 96%, at least 97%, at least 98%,
or at least 99%
sequence identity, to the polypeptide sequence of SEQ ID NO:36. A polypeptide
according to the first aspect of the invention may comprise the polypeptide
sequence of
SEQ ID NO:36.
A polypeptide according to the first aspect of the invention may have at least
90%
sequence identity, or at least 95%, at least 96%, at least 97%, at least 98%,
or at least 99%
sequence identity, to the polypeptide sequence of SEQ ID NO:50. A polypeptide
according to the first aspect of the invention may comprise the polypeptide
sequence of
SEQ ID NO:50.
A polypeptide according to the first aspect of the invention may have an
ability to
bind human CD80 or human CD86 or an extracellular domain of either.
A polypeptide according to the first aspect of the invention may comprise a
polypeptide sequence that is 124 amino acid residues in length.
A polypeptide according to the first aspect of the invention may comprise one
amino acid substitution at an amino acid position selected from the group
consisting of
amino acid positions corresponding to position 50, 54, 55, 56, 64, 65, 70, or
85 relative to
SEQ ID NO:159.
A polypeptide according to the first aspect of the invention may comprise two,
three, or four amino acid substitutions at amino acid positions selected from
the group
consisting of amino acid positions corresponding to position 50, 54, 55, 56,
64, 65, 70, or
85 relative to SEQ ID NO:159.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 70 relative to SEQ ID NO:159, such as the
substitution S70F.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution
at position 104 relative to SEQ ID NO:159, such as the substitution L104E.
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A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 30 relative to SEQ ID NO:159, such as the
substitution T3ON/D/A
or the substitution T3ON.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 64 relative to SEQ ID NO:159, such as the
substitution S64P.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 50 relative to SEQ ID NO:159, such as the
substitution A50M.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 54 relative to SEQ ID NO:159, such as the
substitution M54IC/V or
the substitution M54K.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 65 relative to SEQ ID NO:159, such as the
substitution I65S.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 56 relative to SEQ ID NO:159, such as the
substitution N56D.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 55 relative to SEQ ID NO:159, such as the
substitution G55E.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at positions 85 relative to SEQ ID NO:159, such as the
substitution M85A.
A polypeptide of the first aspect of the invention may comprise an amino acid
substitution at position 24 relative to SEQ ID NO:159, such as the
substitution A24E/S or
the substitution A24E.
A polypeptide of the first aspect of the invention may have a binding affinity
for
CD86 or an extracellular domain thereof that is about equal to or greater than
the binding
affinity of a monomeric human CTLA-4 extracellular domain for CD86 or CD86
extracellular domain.
A polypeptide of the first aspect of the invention may have a binding affinity
for
CD80 or an extracellular domain thereof that is greater than the binding
affinity of a
monomeric human CTLA-4 extracellular domain for CD80 or CD80 extracellular
domain.
A polypeptide of the first aspect of the invention may have an ability to
suppress
an immune response.
A polypeptide of the first aspect of the invention may have an ability to
inhibit T
cell activation or T cell proliferation.
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In a second aspect, the invention provides an isolated or recombinant
polypeptide
multimer comprising at least two polypeptides of the first aspect of the
invention.
In a third aspect, the invention provides an isolated or recombinant fusion
protein
comprising (a) a polypeptide according to the first aspect of the invention,
and (b) a
second polypeptide, wherein the second polypeptide is an 1g Fc polypeptide,
and wherein
the fusion protein has an ability to bind CD80 and/or CD86 or an extracellular
domain of
either or both, and/or an ability to modulate or regulate an immune response.
In a fourth aspect, the invention provides an isolated or recombinant dimeric
fusion
protein comprising two monomeric fusion proteins according to the third aspect
of the
invention.
In a fifth aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a nucleotide sequence that encodes a polypeptide of the first
aspect of the
invention, a multimer of the second aspect of the invention, a fusion protein
of the third
aspect of the invention, or a dimeric fusion protein of the fourth aspect of
the invention.
In a sixth aspect, the invention provides a vector comprising a nucleic acid
of the
fifth aspect of the invention.
In a seventh aspect, the invention provides an isolated or recombinant host
cell
comprising a polypeptide of the first aspect of the invention, a multimer of
the second
aspect of the invention, a fusion protein of the third aspect of the
invention, a dimeric
fusion protein of the fourth aspect of the invention, a nucleic acid of the
fifth aspect of the
invention, and/or a vector of the sixth aspect of the invention.
In an eighth aspect, the invention provides a pharmaceutical composition
comprising a pharmaceutically acceptable excipient, pharmaceutically
acceptable carrier,
or pharmaceutically acceptable diluent and one or more of the following: a
polypeptide of
the first aspect of the invention, a multimer of the second aspect of the
invention, a fusion
protein of the third aspect of the invention, a dimeric fusion protein of the
fourth aspect of
the invention, a nucleic acid of the fifth aspect of the invention, a vector
of the sixth aspect
of the invention, and/or a host cell of the seventh aspect of the invention.
In a ninth aspect, the invention provides a method for suppressing an immune
response, said method comprising contacting a B7-positive cell with an
effective amount
of at least one of: a polypeptide of the first aspect of the invention, a
multimer of the
second aspect of the invention, a fusion protein of the third aspect of the
invention, a
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dimeric fusion protein of the fourth aspect of the invention, a nucleic acid
of the fifth
aspect of the invention, a vector of the sixth aspect of the invention, and/or
a host cell of
the seventh aspect of the invention, to suppress an immune response, wherein
an immune
response is thereby suppressed.
In a tenth aspect, the invention provides a polypeptide of the first aspect of
the
invention, a multimer of the second aspect of the invention, a fusion protein
of the third
aspect of the invention, a dimeric fusion protein of the fourth aspect of the
invention, a
nucleic acid of the fifth aspect of the invention, a vector of the sixth
aspect of the
invention, and/or a host cell of the seventh aspect of the invention, for use
in suppressing
an immune response.
In an eleventh aspect, the invention provides the use of a polypeptide of the
first
aspect of the invention, a multimer of the second aspect of the invention, a
fusion protein
of the third aspect of the invention, a dimeric fusion protein of the fourth
aspect of the
invention, a nucleic acid of the fifth aspect of the invention, a vector of
the sixth aspect of
the invention, and/or a host cell of the seventh aspect of the invention, in
the manufacture
of a medicament for suppressing an immune response.
= In a twelfth aspect, the invention provides a conjugate comprising a
polypeptide of
the first aspect of the invention, a multimer of the second aspect of the
invention, a fusion
protein of the third aspect of the invention, or a dimeric fusion protein of
the fourth aspect
of the invention, and a non-polypeptide moiety covalently attached to such
polypeptide,
multimer, fusion protein, or dimeric fusion protein, wherein said conjugate
has an ability
to suppress an immune response.
Other aspects of the invention are described below.
In another aspect, the invention provides an isolated or recombinant
polypeptide
comprising a polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
sequence identity to at least one polypeptide sequence selected from the group
consisting
of SEQ ID NOS:1-73, wherein the polypeptide binds CD80 or CD86 or an
extracellular
domain (ECD) of either, and/or has an ability to suppress or inhibit an immune
response.
In another aspect, the invention provides an isolated or recombinant
polypeptide
comprising a polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
sequence identity to at least one polypeptide sequence selected from the group
consisting
of SEQ ID NOS:1-73, wherein the polypeptide has a binding affinity for a human
CD86
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extracellular domain or human CD80 extracellular domain that is about equal to
or greater
than the binding affinity of a human CTLA-4 extracellular domain for the human
CD86
extracellular domain or human CD80 extracellular domain, respectively, and
wherein the
polypeptide optionally has an ability to suppress an immune response. Some
such
polypeptides have a binding affinity for the human CD86 extracellular domain
that is
greater than the binding affinity of the human CTLA-4 extracellular domain for
the human
CD86 extracellular domain. Some such polypeptides have a binding affinity for
the
human CD80 extracellular domain that is greater than the binding affinity of
the human
CTLA-4 extracellular domain for the human CD80 extracellular domain.
In another aspect, the invention provides an isolated or recombinant mutant
CTLA-
4 polypeptide comprising a polypeptide sequence which (a) differs from the
polypeptide
sequence of the extracellular domain of human CTLA-4 shown in SEQ ID NO:159 in
no
more than 10, 9, 8, 7, or 6 amino acid residues (e.g., no more than 1, 2, 3,
4, 5, 6, 7, 8 , 9,
or 10 amino acid residues), and (b) comprises at least one amino acid
substitution at an
amino acid position corresponding to position 50, 54, 55, 56, 64, 65, 70, or
85 relative to
SEQ ID NO:159, wherein the mutant CTLA-4 polypeptide has an ability to bind
CD80 or
CD86 or an extracellular domain of either, and/or has an ability to suppress
or inhibit an
immune response.
In another aspect, the invention provides an isolated or recombinant
polypeptide
which comprises a polypeptide sequence comprising (i) at least 95%, 96%, 97%,
98%,
99%, or 100% sequence identity to a polypeptide sequence selected from the
group
consisting of SEQ ID NOS:1-73 and (ii) a phenylalanine residue at an amino
acid position
corresponding to position 70 of said polypeptide sequence selected from the
group
consisting of SEQ ID NO:1-73, wherein the polypeptide has an ability to bind
CD80
and/or CD86 or an extracellular domain of either or both, and/or has an
ability to suppress
or inhibit an immune response.
In another aspect, the invention provides an isolated or recombinant mutant
CTLA-
4 polypeptide that binds CD80 and/or CD86 and/or an extracellular domain of
either or
both, and/or is capable of suppressing an immune response, wherein said
polypeptide
comprises a polypeptide sequence which (a) differs from the polypeptide
sequence of
human CTLA-4 extracellular domain polypeptide shown in SEQ ID NO:159 in no
more
than 10, 9, 8, 7, or 6 amino acid residues (e.g., no more than 1, 2, 3, 4, 5,
6, 7, 8 , 9, or 10
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amino acid residues), and (b) comprises at least one amino acid substitution,
wherein said
at least amino acid substitution comprises S70F, wherein amino acid residue
positions are
numbered according to SEQ ID NO:159.
In another aspect, the invention provides an isolated or recombinant mutant
CTLA-
4 polypeptide comprising a polypeptide sequence which (a) differs from the
polypeptide
sequence of the extracellular domain of human CTLA-4 shown in SEQ ID NO:159 in
no
more than 11, 10, 9, 8, 7, or 6 amino acid residues (e.g., no more than 1,2,
3, 4, 5, 6, 7, 8,
9, 10, or 11 amino acid residues), and (b) comprises at least one amino acid
substitution at
an amino acid residue position corresponding to position 24, 30, 32, 50, 54,
55, 56, 64, 65,
70, or 85 relative to SEQ ID NO:159, wherein the mutant CTLA-4 polypeptide has
an
ability to bind CD80 or CD86 or an extracellular domain of either, and/or has
an ability to
suppress or inhibit an immune response.
In another aspect, the invention provides an isolated or recombinant
polypeptide
comprising a polypeptide sequence which (a) differs from the polypeptide
sequence shown
in SEQ ID NO:31 in no more than 10, 9, 8, 7, or 6 amino acid residues (e.g.,
no more than
1, 2, 3,4, 5, 6,7, 8 , 9, or 10 amino acid residues), and (b) comprises at
least one of the
following: a methionine residue at a position corresponding to position 50 of
SEQ ID
NO:31, a lysine residue at a position corresponding to position 54 of SEQ ID
NO:31, a
glutamic acid residue at a position corresponding to position 55 of SEQ ID
NO:31, a
proline residue at a position corresponding to position 64 of SEQ ID NO:31, a
serine
residue at a position corresponding to position 65 of SEQ ED NO:31, a
phenylalanine
residue at a position corresponding to position 70 of SEQ ID NO:31, wherein
amino acid
residue positions are numbered according to SEQ ID NO:31, and the polypeptide
binds
CD80 and/or CD86 and/or an ECD of either or both, and/or inhibits an immune
response.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer comprising two monomeric fusion proteins linked via at least one
disulfide bond
formed between two cysteine residues present in each monomeric mutant fusion
protein,
wherein each monomeric fusion protein comprises (a) a polypeptide comprising a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity
to at
least one polypeptide sequence selected from the group consisting of SEQ ID
NOS:1-73
and (b) an Ig Fc polypeptide, wherein the fusion protein dimer has an ability
to bind CD80
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and/or CD86, and/or CD80-Ig and/or CD86-Ig, and/or has an ability to inhibit
or suppress
an immune response.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer comprising two monomeric fusion proteins, each such monomeric fusion
protein
comprising a polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
sequence identity to at least one polypeptide sequence selected from the group
consisting
of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222, wherein the polypeptide
binds
CD80 and/or CD86 and/or an extracellular domain thereof and/or suppresses an
immune
response, or a complementary polynucleotide sequence thereof.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer comprising two monomeric fusion proteins, wherein each monomeric fusion
protein
comprises: (1) a polypeptide comprising a polypeptide sequence which differs
from a
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73 in
no more
than 10, 9, 8, 7, or 6 amino acid residues (e.g., no more than 1, 2, 3,4, 5,
6, 7, 8 , 9, or 10
amino acid residues), and wherein the amino acid residue in the polypeptide
sequence at
position 41, 50, 54, 55, 56, 64, 65, 70, or 85 is identical to the amino acid
residue at the
corresponding position of said selected polypeptide sequence, and (2) an Ig Fc
polypeptide, wherein the fusion protein dimer binds CD80 and/or CD86, and/or
inhibits an
immune response.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer comprising two monomeric fusion proteins, wherein each monomeric fusion
protein
comprises: (1) a mutant CTLA-4 extracellular domain polypeptide comprising a
polypeptide sequence which (i) differs from the polypeptide sequence of the
extracellular
domain of human CTLA-4 shown in SEQ ID NO:159 in no more than 10, 9, 8, 7, or
6
amino acid residues (e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8 , 9, or 10
amino acid residues),
and (ii) comprises at least one amino acid substitution at an amino acid
position
corresponding to position 50, 54, 55, 56, 64, 65, 70, or 85 relative to the
polypeptide
sequence of SEQ ID NO:159; and (2) an Ig Fc polypeptide, wherein the fusion
protein
dimer binds CD80 and/or CD86, and/or suppresses or inhibits an immune
response. Some
such fusion protein dimers comprise one or more substitutions at amino acid
positions
relative to SEQ ID NO:159 selected from the group consisting of A50M, M54K,
G55E,
N56D, S64P, I65S, and S70F; and (2) an Ig Fc polypeptide, which Ig Fc
polypeptide
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optionally is IgG2 Fc polypeptide, wherein the mutant CTLA-4-Ig dimer binds
hCD80
and/or hCD86, and/or suppresses or inhibits an immune response.
In another aspect, the invention provides an isolated or recombinant
polypeptide
comprising a polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
sequence identity to a polypeptide sequence selected from the group consisting
of SEQ ID
NO:26, SEQ ID NO:36, SEQ ID NO:38, SEQ ID NO:50, and SEQ ID NO:56, wherein the
polypeptide (i) binds CD80 and/or CD86 or an extracellular domain of either or
both,
and/or (ii) suppresses an immune response.
In another aspect, the invention provides an isolated or recombinant
polypeptide
comprising a polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
sequence identity to a polypeptide sequence selected from the group consisting
of SEQ ID
NOS:74-79, 197-200, 205-214, and 219-222, wherein the polypeptide (i) binds
CD80
and/or CD86 or an extracellular domain of either or both, (ii) binds a CD80-Ig
fusion
protein and/or CD86-Ig fusion protein, and/or (iii) suppresses an immune
response.
Also provided is an isolated or recombinant fusion protein dimer comprising
two
monomeric fusion proteins linked via at least one disulfide bond formed
between two
cysteine residues present in each monomeric mutant fusion protein, wherein
each
monomeric fusion protein comprises (a) a polypeptide comprising a polypeptide
sequence
having at least 95% identity to at least one polypeptide sequence selected
from the group
consisting of SEQ ID NO:79, SEQ ID NO:197, SEQ ID NO:198, SEQ ID NO:199, and
SEQ ID NO:200 and (b) an Ig Fc polypeptide, wherein the fusion protein dimer
has (i) an
ability to bind CD80 and/or CD86 and/or an extracellular domain of CD80 and/or
CD86,
(ii) an ability to bind CD80-Ig and/or CD86-Ig, and/or (iii) has an ability to
inhibit or
suppress an immune response.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence that encodes a polypeptide comprising a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99% or 100% sequence
identity to at least one polypeptide sequence selected from the group
consisting of SEQ ID
NOS:1-79, 197-200, 205-214, and 219-222, wherein the polypeptide binds CD80
and/or
CD86 and/or an extracellular domain of either or both, and/or has an ability
to suppress an
immune response, or a complementary polynucleotide sequence thereof.
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In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence that encodes a fusion protein comprising
a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99% or 100% sequence
identity to at least one polypeptide sequence selected from the group
consisting of SEQ ID
NOS: 74-79, 197-200, 205-214, and 219-222, wherein the polypeptide binds CD80
and/or
CD86 and/or an extracellular domain thereof and/or suppresses an immune
response, or a
complementary polynucleotide sequence thereof.
In another aspect, the invention provides an isolated of recombinant nucleic
acid
comprising: (a) a polynucleotide sequence having at least 95%, 96%, 97%, 98%,
99% or
100% sequence identity to at least one polynucleotide sequence selected from
the group
consisting of SEQ ID NOS:80-158, 201-204, 223, and 224; (b) a complementary
polynucleotide sequence of (a); or (c) a fragment of any polynucleotide
sequence of (a) or
(b), wherein the nucleic acid encodes a polypeptide that binds CD80 and/or
CD86 and/or
an extracellular domain of either or both, and/or has an ability to suppress
or inhibit an
immune response.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide which
comprises a
polypeptide sequence (a) which differs from a polypeptide sequence selected
from the
group consisting of SEQ ID NOS:1-73 in no more than 10, 9, 8, 7, or 6 amino
acid
residues (e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8 , 9, or 10 amino acid
residues), and (b)
wherein the amino acid residue in the polypeptide sequence at position 41, 50,
54, 55, 56,
64, 65, 70, or 85 is identical to the amino acid residue at the corresponding
position of said
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73,
wherein
the polypeptide binds CD80 and/or CD86 and/or an extracellular domain of
either or both,
and/or inhibits an immune response, or a complementary polynucleotide sequence
thereof.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide comprising a
polypeptide sequence which (a) differs from the polypeptide sequence of the
extracellular
domain of human CTLA-4 shown in SEQ ID NO:159 in no more than 10, 9, 8, 7, or
6
amino acid residues (e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8 , 9, or 10
amino acid residues),
and (b) comprises at least one amino acid substitution at an amino acid
position
corresponding to position 50, 54, 55, 56, 64, 65, 70, or 85 relative to SEQ ID
NO:159,
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wherein said polypeptide has an ability to bind CD80 and/or CD86 and/or an
extracellular
domain of either, and/or has an ability to suppress or inhibit an immune
response, or a
complementary polynucleotide sequence thereof.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide comprising a
polypeptide sequence having (i) at least 95%, 96%, 97%, 98%, 99%, or 100%
identity to a
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73 and
(ii) a
phenylalanine residue at an amino acid position corresponding to position 70
of said
polypeptide sequence selected from the group consisting of SEQ ID NO:1-73,
wherein the
polypeptide binds hCD80 and/or hCD86 or an LCD thereof and/or inhibits an
immune
response, wherein said amino acid substitution optionally comprises S70F, or a
complementary polynucleotide sequence thereof.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a recombinant polypeptide
dimer
comprising two polypeptides, wherein each such polypeptide comprises a
polypeptide
sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity to a
sequence
selected from the group consisting of SEQ ID NOS:1-73, wherein the dimer binds
hCD80
and/or hCD86 and/or inhibits an immune response, or a complementary
polynucleotide
sequence thereof.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a fusion protein comprising
(a) a
polypeptide comprising a polypeptide sequence that has at least 95%, 96%, 97%,
98%,
99%, or 100% identity to at least one polypeptide sequence selected from the
group
consisting of SEQ ID NOS:1-73, and (b) an Ig polypeptide, wherein the fusion
protein
binds CD80 and/or CD86, and/or has an ability to suppress an immune response,
or a
complementary polynucleotide sequence thereof.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide comprising a
polypeptide sequence which (a) differs from the polypeptide sequence shown in
SEQ ID
NO:31 in no more than 10, 9, 8, 7, or 6 amino acid residues (e.g., no more
than 1, 2, 3, 4,
5, 6, 7, 8 , 9, or 10 amino acid residues), and (b) comprises at least one of
the following: a
methionine residue at a position corresponding to position 50 of SEQ ID NO:31,
a lysine
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residue at a position corresponding to position 54 of SEQ ID NO:31, a glutamic
acid
residue at a position corresponding to position 55 of SEQ ID NO:31, a proline
residue at a
position corresponding to position 64 of SEQ ID NO:31, a serine residue at a
position
corresponding to position 65 of SEQ ID NO:31, a phenylalanine residue at a
position
corresponding to position 70 of SEQ ID NO:31, wherein amino acid residue
positions are
numbered according to SEQ ID NO:31, and wherein the polypeptide binds CD80
and/or
CD86, and/or inhibits an immune response, or a complementary polynucleotide
sequence
thereof.
In another aspect, the invention provides an expression vector comprising: (i)
a
first polynucleotide sequence that encodes a first polypeptide comprising a
polypeptide
sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity to at least
one
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73,
wherein
said first polypeptide binds human CD86 and/or human CD80 and/or an
extracellular
domain of either or both, and/or suppresses an immune response, and (ii) a
second
polynucleotide sequence that encodes a second polypeptide comprising a hinge
region, a
CH2 domain, and a CH3 domain of an immunoglobulin (1g) polypeptide, which Ig
polypeptide is optionally human IgG2 Fc polypeptide.
In another aspect, the invention provides an isolated or recombinant host cell
transfected with a nucleic acid encoding a fusion protein, the nucleic acid
comprising: (i) a
first nucleotide sequence encoding a first polypeptide comprising a
polypeptide sequence
having at least 95%, 96%, 97%, 98%, 99%, or 100% identity to at least one
polypeptide
sequence selected from the group consisting of SEQ ID NOS:1-73, wherein said
first
polypeptide has an ability to bind human CD86 and/or human CD80 and/or an
extracellular domain of either or both, and/or has an ability to suppress an
immune
response; and (ii) a second nucleotide sequence encoding a second polypeptide
comprising
a hinge region, a CH2 domain, and a CH3 domain of an immunoglobulin (Ig)
polypeptide,
which Ig polypeptide is optionally human IgG2 Fc polypeptide, wherein the host
cell is
capable of expressing the fusion protein.
In another aspect, the invention provides a method of suppressing an immune
response, said method comprising contacting a B7-positive cell with an
effective amount
of at least one polypeptide, conjugate, nucleic acid, vector, or cell of the
invention to
suppress an immune response, wherein an immune response is thereby suppressed.
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In another aspect, the invention provides a method of modulating the
interaction of
T cells expressing CD28 and/or CTLA-4 with B7-positive cells, the method
comprising
contacting B7-positive cells with an effective amount of at least one
polypeptide,
conjugate, nucleic acid, vector, or cell of the invention to modulate the
interaction of B7-
positive cells with CD28-positive T cells and/or CTLA-4-positive T cells,
wherein the
interaction of B7-positive cells with CD28-positive T cells and/or CTLA-4-
positive T cells
is modulated.
In another aspect, the invention provides a method of inhibiting the
interaction of
CD28-positive T cells and/or CTLA-4-positive T cells with B7-positive cells,
the method
comprising contacting B7-positive cells with an effective amount of at least
one
polypeptide, conjugate, nucleic acid, vector, or cell of the invention,
wherein the =
interaction of CD28-positive T cells and/or CTLA-4-positive T cells with B7-
positive cells
is inhibited.
In another aspect, the invention provides a method of inhibiting the
interaction of
CD28-positive T cells with B7-positive cells in a subject, said method
comprising
administering to a subject an effective amount of at least one polypeptide,
conjugate,
nucleic acid, vector, or cell of the invention, wherein the interaction of
endogenous CD28-
positive T cells with endogenous B7-positive cells in the subject is
inhibited.
In another aspect, the invention provides a method of treating a subject
having an
immune system disease or disorder modulated by interaction of endogenous T
cells with
endogenous cells expressing CD80 and/or CD86, said method comprising
administering to
a subject in need of such treatment a therapeutically effective amount of at
least one
polypeptide, conjugate, nucleic acid, vector, or cell of the invention,
wherein interaction(s)
between endogenous T cells and endogenous cells expressing said CD80 and/or
said
CD86 is inhibited, thereby treating the immune system disease or disorder in
the subject.
In another aspect, the invention provides a method of inhibiting rejection of
a
tissue or organ transplant from a donor by a recipient subject, the method
comprising
administering to the recipient subject in need thereof a therapeutically
effective amount of
at least one polypeptide, conjugate, nucleic acid, vector, or cell of the
invention, thereby
inhibiting rejection of the tissue or organ transplant by the recipient
subject.
In another aspect, the invention provides a method of making a fusion protein,
the
method comprising: (I) culturing a host cell transformed with a nucleic acid
in a culture
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medium, wherein the nucleic acid comprises (i) a first nucleotide sequence
that encodes a
polypeptide having at least 95%, 96%, 97%, 98%, 99%, or 100% identity to a
polypeptide
sequence of any of SEQ ID NOS:1-73, which polypeptide binds CD86 and/or CD80,
and/or
an extracellular domain of either CD86 or CD80, and (ii) a second nucleotide
sequence
encoding an Ig polypeptide comprising a hinge region, CH2 domain, and CH3
domain,
whereby the nucleic acid is expressed and a fusion protein is produced; and
(2) recovering the
fusion protein.
Also provided is a method of producing a polypeptide comprising introducing
into a population of cells a nucleic acid of the invention, wherein the
nucleic acid is
operatively linked to a regulatory sequence effective to produce the
polypeptide encoded by
the nucleic acid; culturing the cells in a culture medium to produce the
polypeptide; and
isolating the polypeptide from the cells or culture medium.
Also provided are compositions which comprise a molecule of the invention
(e.g., mutant CTLA-4 molecule) and an excipient, carrier, or diluent. Also
included are
pharmaceutical compositions comprising a molecule of the invention and a
pharmaceutically
acceptable and an excipient, carrier, or diluent.
Specific aspects of the invention include:
- an isolated or recombinant fusion protein dimer comprising two monomeric
fusion proteins linked via at least one disulfide bond formed between two
cysteine residues
present in each monomeric fusion protein, wherein each monomeric fusion
protein comprises
(a) a polypeptide comprising a polypeptide sequence which differs from SEQ ID
NO:50 in no
more than 6 amino acid residues and which includes residues at positions 24,
30, 32, 41, 50,
54, 55, 56, 64, 65, 70, 85, 104 and 106 that are identical to the amino acid
residues at the
corresponding positions in SEQ ID NO:50 and (b) an Ig Fc polypeptide, and
wherein the
fusion protein dimer binds human CD80 or human CD86 or an extracellular domain
of either
and has a greater ability to suppress an immune response than a LEA29Y-Ig
fusion protein
dimer, wherein the LEA29Y-Ig fusion protein dimer comprises two monomeric
LEA29Y-Ig
fusion proteins each comprising the polypeptide sequence of SEQ ID NO:166;
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- an isolated or recombinant nucleic acid comprising a polynucleotide sequence
that encodes the monomeric fusion protein of the fusion protein dimer of the
invention; and
- the fusion protein dimer of the invention, for use in: (i) inhibiting or
suppressing an immune response in a mammal; (ii) the treatment of an immune
system
disease or disorder; or (iii) the treatment of tissue or organ transplant
rejection in a mammal.
Additional aspects of the invention are described below.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 is a schematic diagram of the plasmid expression vector pCDNA
mutant CTLA-4-Ig, which comprises a nucleotide sequence encoding a mutant CTLA-
4-Ig
fusion protein. In Figure 1, each mutant CTLA-4-Ig fusion protein comprises a
mutant
CTLA-4 ECD polypeptide of the invention fused at its C-terminus to the N-
terminus of a
human IgG2 (hIgG2) Fc polypeptide.
Figures 2A-2D are schematic diagrams of exemplary hCD80-Ig, hCD86-Ig,
LEA29Y-Ig, and hCTLA-4-IgG2 fusion proteins, respectively. The signal peptide,
extracellular domain (ECD), linker (if any), and Ig Fc domain of each fusion
protein are
shown schematically. The amino acid residues present at the junctions between
the signal
peptide, ECD, linker (if any), and Ig Fc are also shown. The signal peptide of
each fusion
protein is typically cleaved during processing and thus the secreted (mature)
fusion protein
typically does not contain the signal peptide sequence. Figure 2D presents a
schematic
diagram of a human CTLA-4-IgG2 ("hCTLA-4-Ig02") fusion protein comprising a
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human CTLA-4 extracellular domain (liCTLA-4 ECD-) covalently fused at its C-
terminus to the N-terminus of a human IgG2 polypeptide. The predicted
polypeptide
sequence of this hCTLA-4-IgG2 fusion protein is shown in SEQ ID NO:161 and
comprises the following segments: hCTLA-4 signal peptide (amino acid residues
1-37).
hCTLA-4 ECD polypeptide (amino acid residues 38-161), and human IgG2 Fc
polypeptide (amino acid residues 162-389). No linker (e.g., no amino acid
residue(s)) is
included between the C-terminus of the hCTLA-4 ECD polypeptide and the N-
terminus of
the human IgG2 Fc. The human IgG2 Fc polypeptide comprises a hinge, CH2
domain,
and CH3 domain of human IgG2. In Figure 2D, the amino acid residues at the
junctions
between these various segments are shown. Specifically, the last four amino
acid residues
of the signal peptide, the first five and last five amino acid residues of the
hCTLA-4 ECD
polypeptide, and the first five and last five amino acid residues of the human
IgG2 Fc
polypeptide are shown.
The signal peptide is typically cleaved during processing and thus the
secreted
fusion protein (mature fusion protein) of hCTLA-4-IgG2 does not typically
contain the
signal peptide sequence. The polypeptide sequence of the mature or secreted
form of this
hCTLA-4-IgG2 fusion protein is shown in SEQ ID NO:162. The sequence of the
hCTLA-
4 ECD polypeptide comprises amino acid residues 1-124 of SEQ ID NO:162, and
the
sequence of human Ig02 Fc polypeptide comprises amino acid residues 125-352 of
SEQ
ID NO:162. In another aspect, this mature hCTLA-4 Ig fusion protein does not
include
the C-terminal lysine (K) residue and thus comprises amino acid residues 1-351
of SEQ
ID NO:162.
The mature hCTLA-4-IgG2 fusion protein, which has a total of 352 amino acids,
comprises amino acid residues 38-389 of the polypeptide sequence of the full-
length WT
hCTLA-4 protein shown in SEQ ID NO:160, and begins with the amino acid
sequence:
methionine-histidine-valine-alanine. If desired, the amino acids of the mature
form can be
numbered beginning with the Met of the Met-His-Val-Ala sequence, designating
Met as
the first residue (e.g., the ECD comprises amino acid residues numbered 1-
124), as in SEQ
ID NO:162. A mature hCTLA-4IgG2 dimer is the form of the fusion protein
typically
used in the assays of the Examples described infra, unless stated otherwise. A
DNA
sequence encoding the hCTLA-4-IgG2 fusion protein, which comprises the hCTLA-4
ECD fused to the hIgG2 Fc polypeptide, is shown in SEQ ID NO:163.
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Figure 3 represents SDS/PAGE analyses of the following proteins: molecular
weight markers of various mass (kilodaltons (kDa) (lane 1); an exemplary
mutant CTLA-
4-Ig fusion protein of the invention based on clone D3 (i.e., D3-IgG2) (lane
2); an
exemplary mutant CTLA-4-Ig fusion protein based on clone D4 (i.e., D4-IgG2)
(lane 3);
and the Orencia (Abatacept) fusion protein (lane 4) (Bristol-Myers Squibb
Co.,
Princeton, NJ).
Figure 4 presents an elution profile of an exemplary mutant CTLA-4-Ig fusion
protein of the invention (i.e., D3-IgG2) from SEC analysis, demonstrating that
mutant
CTLA-4-Ig fusion proteins of the invention are homogenous in size when
purified from
transiently-transfected COS cells.
Figure 5 shows a typical BiacoreTm analysis of the binding of the following
fusion
proteins to hCD86-Ig: Orencia fusion protein, LEA29Y-Ig, and D3-IgG2. The
dissociation phase of the analysis begins at the time marked by the arrow. The
Orencia
fusion protein, which is composed of the wild-type human CTLA-4 ECD
polypeptide
fused to a mutant IgG1 Fe domain polypeptide, effectively serves as a wild-
type human
CTLA-4-Ig control. A mutant CTLA-4-Ig fusion protein of the invention, such as
D3-
IgG2, which has a higher avidity binding to CD86-Ig than the Orencia fusion
protein has
a slower rate of dissociation from CD86-Ig than the Orencia protein.
Figure 6 is a graphical representation of the results of PBMC proliferation
inhibition assays (with anti-CD3 antibody stimulation) involving exemplary
mutant
CTLA-4-Ig fusion proteins of the invention (D3-04-IgG2, D3-11-IgG2, D3-12-
IgG2, D3-
14-IgG2). These assays show that mutant CTLA-4-Ig fusion proteins of the
invention are
significantly more potent than Orencia and LEA29Y-Ig in inhibiting T cell
proliferation
in vitro.
Figure 7 is a graphical representation of CD4+ T cell proliferation inhibition
assays
(with anti-CD3 stimulation and hB7.2-dependent costimulation) involving an
exemplary
set of mutant CTLA-4-Ig fusion proteins of the invention. The Orencia and
LEA29Y-Ig
fusion proteins were included as controls for comparison.
Figure 8 is a graphical representation of PBMC proliferation inhibition assays
(with PPD antigen stimulation) involving an exemplary set of mutant CTLA-4-Ig
fusion
proteins of the invention. Orencia and LEA29Y-Ig were included as controls
for
comparison.
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Figure 9 is a graphical representation of one-way mixed lymphocyte reaction
(MLR) proliferation inhibition assays involving an exemplary mutant CTLA-4-Ig
fusion
protein of the invention ¨ D3-IgG2. The Orencia and LEA29Y-Ig fusion proteins
were
included as controls for comparison.
Figure 10 is a schematic diagram showing the structure of an exemplary mutant
CTLA-4-Ig fusion protein of the invention. Two identical monomeric mutant CTLA-
4-Ig
fusion proteins are shown schematically, each comprising a mature mutant CTLA-
4 ECD
fused at its C-terminus to the N-terminus of a human IgG2 Fc polypeptide. Each
human
IgG2 polypeptide includes an IgG2 hinge, CH2 domain, and CH3 domain. Exemplary
amino acid residues present at the junctions between the ECD and Ig Fc
polypeptides are
also shown. The amino acid residues at the junctions between these components
may
differ depending upon the mutant CTLA-4 ECD polypeptide sequence and/or Ig
polypeptide sequence. The dimeric fusion protein results from the formation of
at least
one disulfide bond between cysteine residues at analogous positions in the two
monomers.
The cysteine (C) residues potentially involved in forming disulfide bonds
between the two
monomers are marked with asterisks. The signal peptide of each monomeric
fusion
protein is typically cleaved during processing and thus the secreted (mature)
fusion protein
typically does not include the signal peptide sequence.
Figure 11 is a graphical representation of CD4+ T cell proliferation assays
(with
anti-CD3 stimulation and hB7.2-dependent costimulation) involving hCTLA-4-
IgG2,
Orencia and LEA29Y-Ig fusion proteins.
Figures 12A-12F present an alignment of the polypeptide sequence of the wild-
type human CTLA-4 extracellular domain (designated in the figure as
"hCTLA4ECD''),
the polypeptide sequence of the LEA29Y polypeptide (designated in the figure
as
"LEA29YECD"), and the polypeptide sequences of exemplary mutant CTLA-4 ECD
polypeptides of the invention. The clone names of these mutant CTLA-4 ECD
polypeptides of the invention are indicated at the left. Amino acid residues
that are
identical to those in the wild-type human CTLA-4 ECD are indicated with a
period (.).
Figure 13 presents a BLOSUM62 matrix.
Figures 14A-14D show exemplary alignments and alignment scores determined by
manual calculation for two amino acid sequences.
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Figures 15A-15B show pharmacokinetic (PK) profiles for Orencia0 fusion
protein,
human CTLA-4-IgG2, and representative mutant CTLA-4-IgG2 fusion proteins of
the
invention administered at 1 ms.,,/kg as a single (A) intravenous (IV) bolus or
(B)
subcutaneous (SC) injection in rats.
DETAILED DESCRIPTION OF THE INVENTION
DEFINITIONS
It is also to be understood that the terminology used herein is for the
purpose of
describing particular embodiments only and is not intended to be limiting.
Unless defined
otherwise, all technical and scientific terms used herein have the same
meaning as
commonly understood by one of ordinary skill in the art to which the invention
pertains.
The terms "nucleic acid" and "polynucleotide" are used interchangeably to
refer to
a polymer of nucleic acid residues (e.g., deoxyribonucleotides or
ribonucleotides) in either
single- or double-stranded form. Unless specifically limited, the terms
encompass nucleic
acids containing known analogues of natural nucleotides that have similar
binding
properties as the reference nucleic acid and are metabolized in a manner
similar to
naturally-occurring nucleotides. Unless otherwise indicated, a particular
nucleic acid
sequence also implicitly encompasses conservatively modified variants thereof
(e.g.,
degenerate codon substitutions) and complementary nucleotide sequences as well
as the
sequence explicitly indicated. Specifically, degenerate codon substitutions
may be
achieved by generating sequences in which the third position of one or more
selected (or
all) codons is substituted with mixed-base and/or deoxyinosine residues
(Batzer et al.,
Nucleic Acid Res. 19:5081 (1991); Ohtsuka et al., J. Biol. Chem. 260:2605 2608
(1985);
and Cassol et al. (1992); Rossolini et al., Mol. Cell. Probes 8:91 98 (1994)).
The term
nucleic acid or polynucleotide is used interchangeably with cDNA or mRNA
encoded by a
gene.
The term "Rene" broadly refers to any nucleic acid segment (e.g., DNA)
associated
with a biological function. A gene may include a coding sequence and/or
regulatory
sequence required for their expression. A gene may also include non-expressed
DNA
nucleic acid segment(s) that, e.g., form recognition sequences for other
protein(s) (e.g.,
promoter, enhancer, or other regulatory region). A gene can be obtained from a
variety of
sources, including cloning from a source of interest or synthesizing from
known or
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predicted sequence information, and may include one or more sequences designed
to have
desired parameters.
The terms "polypeptide," "peptide," and "protein" are used interchangeably to
refer to a polymer of amino acid residues. The terms apply to amino acid
polymers in
which one or more amino acid residue is an artificial chemical mimetic of a
corresponding
naturally occurring amino acid, as well as to naturally occurring amino acid
polymers and
non-naturally occurring amino acid polymers. As used herein, the terms
encompass amino
acid chains of any length, including full-length proteins (i.e., antigens),
wherein the amino
acid residues are linked by covalent peptide bonds.
Numbering of a given amino acid polymer or nucleic acid polymer "corresponds
to" or is "relative to" the numbering of a selected amino acid polymer or
nucleic acid
polymer when the position of any given polymer component (e.g., amino acid,
nucleotide,
also referred to generically as a "residue") is designated by reference to the
same or an
equivalent position in the selected amino acid or nucleic acid polymer, rather
than by the
actual numerical position of the component in the given polymer. Thus, for
example, the
numbering of a given amino acid position in a given polypeptide sequence
corresponds to
the same or equivalent amino acid position in a selected polypeptide sequence
used as a
reference sequence.
An "equivalent position" (for example, an "equivalent amino acid position" or
"equivalent nucleic acid position" or "equivalent residue position") is
defined herein as a
position (such as an amino acid position or nucleic acid position or residue
position) of a
test polypeptide (or test polynucleotide) sequence which aligns with a
corresponding
position of a reference polypeptide (or reference polynucleotide) sequence,
when aligned
(preferably optimally aligned) using an alignment algorithm as described
herein. The
equivalent amino acid position of the test polypeptide sequence need not have
the same
numerical position number as the corresponding position of the test
polypeptide.
Likewise, the equivalent nucleic acid position of the test polynucleotide
sequence need not
have the same numerical position number as the corresponding position of the
test
polynucleotide.
A "mutant" polypeptide comprises a polypeptide sequence that differs in one or
more amino acid residues from the polypeptide sequence of a parent or
reference
polypeptide (such as, e.g., a wild-type (WT) polypeptide sequence). In one
aspect, a
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mutant polypeptide comprises a polypeptide sequence which differs from the
polypeptide
sequence of a parent or reference polypeptide in from about 1%, 2%, 3%, 4%,
5%, 6%,
7%. 8%. 9%, 10%, 11%, 12%, 13%, 14%, 15%. 20%, 30% 40%, 50% or more of the
total
number of residues of the parent or reference polypeptide sequence. In another
aspect, a
mutant polypeptide comprises a polypeptide sequence that has at least about
50%, 60%,
70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,
98%, or 99% sequence identity to the polypeptide sequence of a parent or
reference
polypeptide. In another aspect, a mutant polypeptide comprises a polypeptide
sequence
that differs from the polypeptide sequence of a parent or reference
polypeptide in from 1
to 100 or more amino acid residues (e.g., 1, 2. 3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14,15, 16,
17, 18, 19, 20 or more amino acid residues). A mutant polypeptide may comprise
a
polypeptide sequence that differs from the polypeptide sequence of a parent or
reference
polypeptide by, e.g., the deletion, addition, or substitution of one or more
amino acid
residues (e.g., 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20 or more
amino acid residues) of the parent or reference polypeptide, or any
combination of such
deletion(s), addition(s), and/or substitution(s). The reference or parent
polypeptide may
itself be a mutant polypeptide.
A "mutant" nucleic acid comprises a nucleotide sequence that differs in one or
more nucleic acid residues from the nucleotide sequence of a parent or
reference nucleic
acid (such as a WT nucleic acid). In one aspect, a mutant nucleic acid
comprises a
nucleotide sequence which differs from the nucleotide sequence of a parent or
reference
nucleic acid in from about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%,
13%,
14%, 15%, 20%, 30% 40%, 50% or more of the total number of residues of the
parent or
reference nucleotide sequence. In another aspect, a mutant nucleic acid
comprises a
nucleotide sequence that has at least about 50%, 60%, 70%, 80%, 85%, 86%, 87%,
88%,
89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to
the
nucleotide sequence of a parent or reference nucleic acid. In another aspect,
a mutant
nucleic acid comprises a nucleotide sequence that differs from the nucleotide
sequence of
a parent or reference nucleic acid in from 1 to 100 or more nucleotide
residues (e.g., 1, 2,
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more
nucleotide residues). A
mutant nucleic acid may comprise a nucleotide sequence that differs from that
of a parent
or reference nucleic acid by, e.g., the deletion, addition, or substitution of
one or more
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nucleotide residues (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20 or
more nucleotide residues) of the parent or reference nucleic acid, or any
combination of
such deletion(s), addition(s), and/or substitution(s). A mutation in a nucleic
acid may also
result from an alternative splicing_ or truncation of nucleotides or errors in
processing or
cleavage of nucleotides. The reference or parent nucleic acid may itself be a
mutant
nucleic acid.
"Naturally occurring" as applied to an object means the object is found in
nature
as distinct from being artificially produced by man. "Non-naturally occurring"
as applied
to an object means the object is not naturally occurring (i.e., that the
object cannot be
found in nature). For example, a non-naturally occurring polypeptide refers to
a
polypeptide that has been prepared by man, such as, for example, by being
synthesized in
vitro or prepared artificially.
A "subsequence" or "fragment" of a sequence of interest is any portion of the
entire sequence, up to but not including the entire sequence of interest.
A nucleic acid, protein or other component is "isolated" when it is partially
or
completely separated from components with which it is normally associated
(other
proteins, nucleic acids, cells, synthetic reagents, etc.). On a molar basis,
an isolated
species is more abundant than other species in a composition. For example, an
isolated
species may comprise at least about 50%, 70%, 80%, 85%, 90%, 91%, 92%, 93%,
94%,
95%, 96%, 97%, 98%, 99%, or 100% (on a molar basis) of all macromolecular
species
present. Preferably, the species of interest is purified to essential
homogeneity (i.e.,
contaminant species cannot be detected in the composition by conventional
detection
methods). Purity and homogeneity can be determined using a number of
techniques well
known in the art, such as agarose or polyacrylamide gel electrophoresis of a
protein or
nucleic acid sample, followed by visualization upon staining. If desired, a
high-resolution
technique, such as high performance liquid chromatography (HPLC) or a similar
means
can be utilized for purification of the material.
The term "purified" as applied to nucleic acids or polypeptides generally
denotes a
nucleic acid or polypeptide that is essentially free from other components as
determined
by analytical techniques well known in the art (e.g., a purified polypeptide
or
polynucleotide forms a discrete band in an electrophoretic gel,
chromatographic eluate,
and/or a media subjected to density gradient centrifugation). For example, a
nucleic acid
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or polypeptide that gives rise to essentially one band in an electrophoretic
gel is "purified."
A purified nucleic acid or polypeptide is at least about 50% pure, usually at
least about
75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%,
99.7%, 99.8% or more pure (e.g., percent by weight on a molar basis).
In a related sense, the invention provides methods of enriching compositions
for
one or more molecules of the invention, such as one or more polypeptides or
polynucleotides of the invention. A composition is enriched for a molecule
when there is
a substantial increase in the concentration of the molecule after application
of a
purification or enrichment technique. A substantially pure polypeptide or
polynucleotide
will typically comprise at least about 55%, 60%, 70%, 80%, 85%, 90%, 91%, 92%,
93%,
94%, 95%, 96%, 97%, 98, 99%, 99.5% or more by weight (on a molar basis) of all
macromolecular species in a particular composition.
A nucleic acid or polypeptide is "recombinant" when it is artificial or
engineered,
or derived from an artificial or engineered protein or nucleic acid.
The term "recombinant" when used with reference to a cell typically indicates
that
the cell replicates a heterologous nucleic acid or expresses a polypeptide
encoded by a
heterologous nucleic acid. Recombinant cells can comprise genes that are not
found
within the native (non-recombinant) form of the cell. Recombinant cells also
include
those that comprise genes that are found in the native form of the cell, but
are modified
and re-introduced into the cell by artificial means. The term also encompasses
cells that
comprise a nucleic acid endogenous to the cell that has been modified without
removing
the nucleic acid from the cell; such modifications include those obtained by
gene
replacement, site-specific mutation, and related techniques known to those of
ordinary
skill in the art. Recombinant DNA technology includes techniques for the
production of
recombinant DNA in vitro and transfer of the recombinant DNA into cells where
it may be
expressed or propagated, thereby producing a recombinant polypeptide.
A "recombinant expression cassette" or simply an "expression cassette" is a
nucleic acid construct, generated recombinantly or synthetically, with nucleic
acid
elements that are capable of effecting expression of a structural gene in
hosts compatible
with such sequences. Expression cassettes include at least promoters and
optionally
transcription termination signals. Typically, the recombinant expression
cassette includes
a nucleic acid to be transcribed (e.g., a nucleic acid encoding a desired
polypeptide) and a
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promoter. Additional factors necessary or helpful in effecting expression may
also be
used as described herein. For example, an expression cassette can also include
nucleotide
sequences that encode a signal sequence that directs secretion of an expressed
protein from
the host cell. Transcription termination signals, enhancers, and other nucleic
acid
sequences that influence gene expression, can also be included in an
expression cassette.
An "exogenous" nucleic acid," "exogenous DNA segment," "heterologous
sequence," or "heterologous nucleic acid," as used herein, is one that
originates from a
source foreign to the particular host cell, or, if from the same source, is
modified from its
original form. Thus, a heterologous gene in a host cell includes a gene that
is endogenous
to the particular host cell, but has been modified. Modification of a
heterologous sequence
in the applications described herein typically occurs through the use of
directed molecular
evolution methods. Thus, the terms refer to a DNA segment which is foreign or
heterologous to the cell, or homologous to the cell but in a position within
the host cell
nucleic acid in which the element is not ordinarily found. Exogenous nucleic
acids or
exogenous DNA are expressed to yield exogenous polypeptides.
A "vector" may be any agent that is able to deliver or maintain a nucleic acid
in a
host cell and includes, for example, but is not limited to, plasmids (e.g.,
DNA plasmids),
naked nucleic acids, viral vectors, viruses, nucleic acids complexed with one
or more
polypeptide or other molecules, as well as nucleic acids immobilized onto
solid phase
particles. Vectors are described in detail below. A vector can be useful as an
agent for
delivering or maintaining an exogenous gene and/or protein in a host cell. A
vector may
be capable of transducing, transfecting, or transforming a cell, thereby
causing the cell to
replicate or express nucleic acids and/or proteins other than those native to
the cell or in a
manner not native to the cell. A vector may include materials to aid in
achieving entry of
a nucleic acid into the cell, such as a viral particle, liposome, protein
coating, or the like.
Any method of transferring a nucleic acid into the cell may be used; unless
otherwise
indicated, the term vector does not imply any particular method of delivering
a nucleic
acid into a cell or imply that any particular cell type is the subject of
transduction. The
present invention is not limited to any specific vector for delivery or
maintenance of any
nucleic acid of the invention, including, e.g., a nucleic acid encoding a
mutant CTLA-4
polypeptide of the invention or a fragment thereof (e.g., mutant CTLA-4 ECD)
that binds
CD80 and/or CD86 or a fragment thereof (e.g., a CD80 ECD or CD86 ECD).
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The term "expression vector" typically refers to a nucleic acid construct or
sequence, generated recombinantly or synthetically, with a series of specific
nucleic acid
elements that permit transcription of a particular nucleic acid in a host
cell. The
expression vector typically includes a nucleic acid to be transcribed operably
linked to a
promoter. The term "expression" includes any step involved in the production
of the
polypeptide including, but not limited to, transcription, post-transcriptional
modification,
translation, post-translational modification, and/or secretion.
A "signal peptide" is a peptide (or amino acid) sequence that typically
precedes a
polypeptide of interest and is translated in conjunction with the polypeptide
and directs or
facilitates the polypeptide to the secretory system. A signal peptide is
typically covalently
attached or fused to the amino terminus of the polypeptide of interest and
facilitates
secretion of the polypeptide of interest from a host cell. The signal peptide
is typically
cleaved from the polypeptide of interest following translation.
The term "encoding" refers to the ability of a nucleotide sequence to code for
one
or more amino acids. The term does not require a start or stop codon. An amino
acid
sequence can be encoded in any one of six different reading frames provided by
a
polynucleotide sequence and its complement.
The term "control sequence" is defined herein to include all components, which
are
necessary or advantageous for the expression of a polypeptide of the present
invention.
Each control sequence may be native or foreign to the nucleotide sequence
encoding the
polypeptide. Such control sequences include, but are not limited to, a leader,
polyadenylation sequence, propeptide sequence, promoter, signal peptide
sequence, and
transcription terminator. At a minimum, a control sequence includes a
promoter, and
transcriptional and translational stop signals. The control sequences may be
provided with
linkers for the purpose of introducing specific restriction sites facilitating
ligation of the
control sequences with the coding region of the nucleotide sequence encoding a
polypeptide.
The term "coding sequence" refers to a nucleotide sequence that directly
specifies
the amino acid sequence of its protein product. The boundaries of the coding
sequence are
generally determined by an open reading frame (ORF), which may begin with the
ATG
start codon.
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A nucleic acid is "operably linked" with another nucleic acid sequence when it
is
placed into a functional relationship with another nucleic acid sequence. For
instance, a
promoter or enhancer is operably linked to a coding sequence if it directs
transcription of
the coding sequence. Operably linked means that the DNA sequences being linked
are
typically contiguous and, where necessary to join two protein coding regions,
contiguous
and in reading frame. However, since enhancers generally function when
separated from
the promoter by several kilobases and intronic sequences may be of variable
lengths, some
polynucleotide elements may be operably linked but not contiguous.
A "host cell" is any cell that is susceptible to transformation with a nucleic
acid.
"Substantially the entire length of a polynucleotide sequence" or
"substantially the
entire length of a polypeptide sequence" refers to at least about 50%. 60%,
70%, 75%,
80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,
99%, 99.5% or more of the length of a polynucleotide sequence or polypeptide
sequence,
respectively.
An "antigen" refers to a substance that reacts with the product(s) of an
immune
response stimulated by a specific immunogen. See, e.g., JULIUS CRUSE ET AL.,
ATLAS OF
IMMUNOLOGY 60 (1999); RICHARD COICO ET AL., IMMUNOLOGY: A SHORT COURSE 27-30
(5th ed. 2003). An immune response may comprise a humoral response and/or a
cell-
mediated immune response (e.g., cytotoxic T lymphocytes (CTLs)). Products of
an
immune response may include antibodies and/or CTLs. Antigens are typically
macromolecules (e.g., polypeptides, nucleic acids, complex carbohydrates,
phospholipids,
polysaccharides) that are foreign to the host; that portion of the antigen
known as the
antigenic determinant reacts with (e.g., binds to) the product(s) of the
immune response,
such as an antibody or a specific T cell receptor on a T lymphocyte. An
antigen may, but
not necessarily, induce an immune response as well as react with the
product(s) of the
immune response. "Antigenicity" refers the state or property of being
antigenic ¨ i.e.,
having the properties of an antigen. Specificity of an antigen may be shown in
the relation
of an antigen to its antibody or vice versa; an antigen typically reacts in a
highly specific
fashion with its corresponding antibody and not with the same degree of
specificity with
other antibodies evoked by the immunogen. An "antigenic amount" is an amount
of an
antigen that detectably reacts with the product(s) of an immune response
stimulated by a
specific immunogen.
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An "immunogen" is a substance that is capable of inducing an immune response
rather than immunological tolerance. See, e.g., JULIUS CRUSE ET AL., supra at
60-61;
RICHARD COICO, supra at 27-30. Immunogens also reacts with (e.g., bind) the
product(s)
of the induced immune response that has or have been specifically induced
against them.
Thus, all immunogens are antigens. "Immunogenicity" refers the state Or
property of
being immunogenic ¨ i.e., having the properties of an immunogen. An
"immunogenic
amount" is an amount of an immunogen that is effective to induce a detectable
an immune
response. An immunogen may elicit a strong immune response in a subject, such
as at
least partial or complete protective immunity to at least one pathogen.
An "immunomodulator" or "immunomodulatory" molecule, such as an
irnmunomodulatory polypeptide or nucleic acid, modulates an immune response.
By
"modulation" or "modulating" an immune response is intended that the immune
response
is altered. For example, "modulation" of or "modulating" an immune response in
a
subject generally means that an immune response is stimulated, induced,
inhibited,
decreased, suppressed, increased, enhanced, or otherwise altered in the
subject. Such
modulation of an immune response can be assessed by means known to those
skilled in the
art, including those described below. An "immunosuppressor" or
"immunosuppressant" is
a molecule, such as a polypeptide or nucleic acid, which suppresses an immune
response.
As used herein, an "antibody" (abbreviated "Ab") refers to an immunoglobulin
protein (abbreviated "Ig"), whether natural or wholly or partially
synthetically produced.
The term includes all derivatives thereof that maintain specific binding
ability to an
antigen. The term also covers any protein having a binding domain that is
homologous or
largely homologous to an immunoglobulin binding domain. Such proteins may be
derived
from natural sources, or partly or wholly synthetically produced. An antibody
may be
monoclonal or polyclonal. An antibody may be a member of any immunoglobulin
class,
including any of the five human classes: IgA (which includes subclasses IgAl
and IgA2),
IgD, IgE, IgG (which includes subclasses IgGl, IgG2, IgG3, and IgG4), and IgM.
Antibodies comprise paired heavy and light polypeptide chains, and each such
chain is
composed of individual immunoglobulin domains. Each chain includes a constant
(C)
region and a variable (V) region. A typical antibody structural unit comprises
a tetramer.
Each tetramer is composed of two identical pairs of polypeptide chains, each
pair having
one -light" (about 25 kDa) and one "heavy" chain (about 50-70 kDa). Heavy
chains exist
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in five major types (y, .43, a, and z) depending on the antibody class and
contain about
450-600 amino acid residues. Light chains are of two major types (X and ic)
and contain
about 230 amino acid residues. As an example, an IgG antibody is a tetrameric
protein
comprising two heavy chains and two light chains. Each IgG heavy chain
contains four
immunoglobulin domains linked in the following order from the N-terminus to
the C-
terminus: VH-CH1-CH2-CH3 (also sometimes abbreviated as VH-CHI-CH2-CH3). These
abbreviations refer to the heavy chain variable domain, heavy chain constant
domain 1,
heavy chain constant domain 2, and heavy chain constant domain 3),
respectively. A
heavy chain may also be referred to by antibody class, such as, e.g., Cyl,
which represents
the first constant domain of the gamma (7) heavy chain of IgG antibody. Each
IgG light
chain comprises two immunoglobulin domains linked in the following order from
N- to C-
terminus: VH-CL, wherein VH and CL refer to the light chain variable domain
and light
chain constant domain, respectively.
The variable region of an antibody, which typically comprises about 100 to 110
or
more amino acids at the N-terminus of each polypeptide chain, includes the
antigen
binding determinants and thus is primarily responsible for antigen recognition
and
specificity. The greatest degree of amino acid sequence variability between
antibodies is
found in the variable region. Most sequence variability occurs in the
complementarity
determining regions (CDRs) located in the variable region. There are a total
of six CDRs,
three CDRs in each heavy chain and three CDRs in each light chain, which
together form
the antigen-binding site. The heavy chain CDRs are designated as VH CDR1, VH
CDR2,
and VH CDR3 while the light chain CDRs are designated as VL CDR1, VL CDR2, and
VL
CDR3. The region located outside the CDRs is termed the framework (FR) region.
Framework regions of different antibodies may vary in amino acid residues, but
the degree
of amino acid variability is not nearly as great as that which exists between
the variable
regions of different antibodies. In many instances, the framework regions
provide a stable
or constant scaffold for the amino acid diversity presented by the CDRs.
The term "antibody fragment" refers to any derivative of an antibody that is
less
than full-length. Examples of antibody fragments include, but are not limited
to, e.g., the
antigen binding fragment (Fab) containing VH-CH! and VH-CL, the variable
fragment (Fv)
containing VI{ and VL, the single chain variable fragment (scFv) containing VH
and VL
linked together in one chain, as well as other V region fragments, such as
Fab', F(ab)?,
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F(ab').), dsFv diabody, Fc, and Fd polypeptide fragments. See Scott, T.A. and
Mercer,
El., CONCISE ENCYCLOPEDIA: BIOCHEMISTRY AND MOLECULAR BIOLOGY (de Gruyter, 3d
ed. 1997), and Watson, J.D. et al., RECOMBINANT DNA (2d ed. 1992) (hereinafter
"Watson").
An antibody fragment may be produced by any means known in the art. For
instance, the antibody fragment may be enzymatically or chemically produced by
fragmentation of an intact antibody or it may be recombinantly produced from a
gene
encoding the partial antibody sequence. For example, fragments of antibodies
can be
produced by digestion with a peptidase. For example, pepsin digests an
antibody below
the disulfide linkages in the hinge region to produce F(ab'),, a dimer of a
Fab fragment
which itself is a light chain joined to VH-CH1 by a disulfide bond. The F(ab')
2 may be
reduced under mild conditions to break the disulfide linkage in the hinge
region thereby
converting the (Fab')-, dimer into an Fab' monomer. The Fab' monomer is
essentially a
Fab fragment with part of the hinge region. See FUNDAMENTAL IMMUNOLOGY, W.E.
Paul,
ed., Raven Press, N.Y. (1993) for a more detailed description of antibodies
and antibody
fragments. While various antibody fragments are defined in terms of the
digestion of an
intact antibody, one of skill will appreciate that such Fab fragments may be
synthesized de
novo either chemically or by utilizing recombinant DNA methodology. Thus, the
term
also includes antibody fragments either produced by the modification of whole
antibodies
or synthesized de novo using recombinant DNA methodologies.
Alternatively, the antibody fragment may be wholly or partially synthetically
produced. The antibody fragment may optionally be a single chain antibody
fragment.
Alternatively, the fragment may comprise multiple chains that are linked
together, for
instance, by disulfide linkages. The fragment may also optionally be a
multimolecular
complex. A functional antibody fragment will typically comprise at least about
50 amino
acids and more typically will comprise at least about 200 amino acids.
An Fc region or domain of an immunoglobulin or antibody molecule (also termed
an Ig Fc polypeptide or Fc polypeptide) corresponds largely to the constant
region of the
immunoglobulin heavy chain, and is responsible for various functions,
including the
antibody's effector function(s). For example, the Ig Fc region of IgG molecule
comprises
the immunoglobulin domains CH2 and CH3 and the N-terminal hinge region leading
into
CH2. The hinge region is a portion of the heavy chain between Fc and CH1
containing
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the inter-heavy chain disulfide binds and gives flexibility to the antibody
molecule. The
constant domains of the Fc region interact with cells of the immune system. Fc
receptors
are proteins that bind the Fc region of antibodies. One significant family of
Fc receptors
for the IgG antibody class includes the Fc gamma receptors (FcyR). The binding
of
antibodies to Fc receptors on cells mediates a number of antibody functions.
Different
IgG subclasses exhibit different affinities for Fc gamma receptors. In
general, IgG1 and
IgG3 bind to the receptors with a greater affinity than IgG2 and IgG4. Fc
receptors are
expressed on a variety of cells, including, e.g., B cells. monocytes,
dendritic cells,
neutrophils, and certain lymphocytes. Binding of an Ig Fc to its receptor
brings these
effector cells to sites of the bound antigen, resulting ultimately in
signaling and immune
responses, including B cell activation, inflammatory responses, cytotoxic
responses, and
phagocytic responses.
An Ig Fc fusion is a molecule comprising one or more polypeptides (or one or
more small molecules) operably linked to an Fc region of an immunoglobulin or
antibody.
See, e.g., Chamow et al., 1996, Trends Biotechnol. 14:52-60. Accordingly, an
Ig Fc
fusion protein is a molecule comprising one or more polypeptides operably
linked to an Ig
Fc region. An Ig Fc fusion protein may comprise, for example, the Fc region of
an
antibody (which facilitates effector functions and pharmacokinetics) and the
binding
region or binding domain of a receptor protein or ligand protein or other
protein or
fragment thereof. The binding region or binding domain mediates recognition of
the
target receptor or ligand (comparable to that of antibody variable region of
an antibody for
an antigen). An Ig Fc region may be linked indirectly or directly to one or
more
polypeptides or small molecules (fusion partners). Various linkers known in
the art and as
described in greater detail below can be used to link an Ig Fc to a fusion
partner to
generate an Ig Fc fusion. An Ig Fc fusion protein typically comprises an Ig Fc
region
covalently linked directly or indirectly to at least one polypeptide, which
polypeptide
typically binds a target ligand or receptor.
Monoclonal or polyclonal antibodies can be prepared any technique known in the
art can be used (see, e.g., Kohler & Milstein, Nature 256:495 497 (1975);
Kozbor et al.,
Immunology Today 4: 72 (1983); Cole et al., pp. 77 96 in Monoclonal Antibodies
and
Cancer Therapy (1985)). Techniques for the production of single chain
antibodies (U.S.
Pat. No. 4,946,778) can be adapted to produce antibodies to polypeptides of
the invention.
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In addition. transgenic mice or other organisms, including mammals, may be
used to
express humanized antibodies. Phage display technology can be used to identify
antibodies and heteromeric Fab fragments that specifically bind to selected
antigens (see,
e.g., McCafferty et al.. Nature 348:552 554 (1990); Marks et al.,
Biotechnology 10:779
783 (1992)).
The term "epitope" refers to an antigenic determinant capable of specific
binding
to a part of an antibody. Epitopes usually consist of chemically active
surface groupings
of molecules such as amino acids or sugar side chains and usually have
specific 3-
dimensional structural characteristics, as well as specific charge
characteristics.
Conformational and nonconformational epitopes are distinguished in that the
binding to
the former but not the latter is lost in the presence of denaturing solvents.
A "specific binding affinity" between two molecules, e.g., a ligand and a
receptor,
means a preferential binding of one molecule for another. The binding of
molecules is
typically considered specific if the equilibrium binding association constant
(e.g., KA) is
about 1 x 102 M-1 to about 1 x 1013 M-1 or greater, including about 104 to
1013 M-1, about
106 to 1012 M-1, about 108 M-1 to 1011 M-1 or about 108 to 1010 M-1. Values of
KA for the
binding interaction between an antigen and an antibody typically range from
about 105 M-1
to about 1012 M-1, usually about 107 M-1 to about 1011 M-1, and often about
108 M-1 to
about 1010 M-1. KA (Mr') is determined by calculating ka/kd, where ka is the
association
rate constant and kd is the disassociation rate constant. The units of ka and
kd are M-1 s-1
and s-1, respectively. The equilibrium dissociation constant, KD, is the
reciprocal of KA.
KD = kd/ka. For the reaction A + B <=> AB (representing a single ligand
binding to a
single protein of interest (e.g., receptor)), KD is equal to ([A][13])/[AB].
Non-limiting
examples of well-known techniques for measuring binding affinities and/or
avidities of
molecules include, e.g., BiacoreTm technology (GE Healthcare) as discussed
elsewhere
herein, isothermal titration microcalorimetry (MicroCal LLC, Northampton, MA
USA).
ELISA, and fluorescence activated cell sorting (FACS) methods. For example,
FACS or
other sorting methods may be used to select for populations of molecules (such
as for
example, cell surface-displayed ligands) that specifically bind to the
associated binding
pair member (such as a receptor, e.g., a soluble receptor). Ligand-receptor
complexes
may be detected and sorted e.g., by fluorescence (e.g., by reacting the
complex with a
fluorescent antibody that recognizes the complex). Molecules of interest that
bind an
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associated binding pair member (e.g., receptor) are pooled and re-sorted in
the presence of
lower concentrations of receptor. By performing multiple rounds sorting in the
presence
of decreasing concentrations of receptor (an exemplary concentration range
being on the
order of 10-6 M down to 10-13 M, i.e., 1 micromolar 0..tM) down to 1 nanomolar
(nM), or
less (e.g., 10-11M or 10-12M), depending on the nature of the ligand-receptor
interaction),
populations of the molecule of interest exhibiting specific binding affinity
for the receptor
may be isolated.
The phrase "specifically (or selectively) binds" to an antibody or
"specifically (or
selectively) immunoreactive with," when referring to a protein, refers to a
binding reaction
that is determinative of the presence of the protein in a heterogeneous
population of
proteins and other biologics. Thus, under designated immunoassay conditions,
the
specified antibodies bind to a particular protein at least two times the
background and do
not substantially bind in a significant amount to other proteins present in
the sample.
Specific binding to an antibody under such conditions may require an antibody
that is
selected for its specificity for a particular protein. A variety of
immunoassay formats may
be used to select antibodies specifically immunoreactive with a particular
protein. For
example, solid-phase ELISA immunoassays are routinely used to select
antibodies
specifically immunoreactive with a protein (see, e.g., Harlow & Lane,
Antibodies, A
Laboratory Manual (1988), for a description of immunoassay formats and
conditions that
can be used to determine specific immunoreactivity). Usually, a specific or
selective
reaction will be at least twice background signal or noise and more typically
more than 10
to 100 times background.
The term "cytokine" includes, e.g., but is not limited to, interleukins,
interferons
(IFN), chemokines, hematopoietic growth factors, tumor necrosis factors (TNF),
and
transforming growth factors. In general, these are small molecular weight
proteins that
regulate maturation, activation, proliferation, and differentiation of cells
of the immune
system.
The term "screening" describes, in general, a process that identifies optimal
molecules of the present invention, such as, e.g., including polypeptides of
the invention,
and related fusion proteins comprising the same, and nucleic acids encoding
all such
molecules. Several properties of the respective molecules can be used in
selection and
screening, for example, an ability of a respective molecule to induce or alter
a desired
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immune response in a test system or in an in vitro, ex vivo, or in vivo
application.
"Selection" is a form of screening in which identification and physical
separation are
achieved simultaneously by expression of a selection marker, which, in some
genetic
circumstances, allows cells expressing the marker to survive while other cells
die (or vice
versa). Screening markers include, for example, luciferase, beta-galactosidase
and green
fluorescent protein, reaction substrates, and the like. Selection markers
include drug and
toxin resistance genes, and the like. Another mode of selection involves
physical sorting
based on a detectable event, such as binding of a ligand to a receptor,
reaction of a
substrate with an enzyme, or any other physical process which can generate a
detectable
signal either directly (e.g., by utilizing a chromogenic substrate or ligand)
or indirectly
(e.g., by reacting with a chromogenic secondary antibody). Selection by
physical sorting
can by accomplished by a variety of methods, including, but not limited to,
e.g., y FACS
in whole cell or microdroplet formats.
Because of limitations in studying primary immune responses in vitro, in vivo
studies are particularly useful screening methods. In some such studies, a
polynucleotide
or polypeptide of the invention is first introduced to a test subject (e.g., a
mammal, such as
an animal), and an induced immune response is subsequently studied by
analyzing the
type of immune response in the immunized animal (e.g., antibody production in
the
immunized animal's serum, proliferation of T cells), or by studying the
quality or strength
of the induced immune response in the immunized animal (e.g., induced antibody
titer
level).
The term "subject" as used herein includes, but is not limited to, an organism
or
animal, including mammals and non-mammals. A mammal includes, e.g., but is not
limited to, a human, non-human primate (e.g., baboon, orangutan, monkey,
gorilla),
mouse, dog, pig, cow, goat, cat, rabbit, rat, guinea pig, hamster, horse,
sheep, or other non-
human mammal. A non-mammal includes, e.g., but is not limited to, a non-
mammalian
invertebrate and non-mammalian vertebrate, such as a bird (e.g., a chicken or
duck) or a
fish.
The term "pharmaceutical composition" refers to a composition suitable for
pharmaceutical use in a subject, including an animal or human. A
pharmaceutical
composition typically comprises an effective amount of an active agent and a
carrier,
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excipient, or diluent. The carrier, excipient, or diluent is typically a
pharmaceutically
acceptable carrier, excipient or diluent, respectively.
The term "effective amount" refers to a dosage (or dose) or amount of a
substance
sufficient to produce a desired result. The desired result may comprise an
objective or
subjective improvement in the recipient of the dosage or amount. For example,
the
desired result may comprise a measurable, detectable or testable induction,
promotion,
enhancement or modulation of an immune response in a subject to whom a dosage
or
amount of a particular antigen or immunogen (or composition thereof) has been
administered. A dosage (or dose) or amount of an immunogen sufficient to
produce such
result can be described as an "immunogenic" dosage (or dose) or amount.
A "prophylactic treatment" is a treatment administered to a subject who does
not
display signs or symptoms of, or displays only early signs or symptoms of, a
disease,
pathology, or disorder, such that treatment is administered for the purpose of
preventing or
decreasing the risk of developing the disease, pathology, or disorder. A
prophylactic
treatment functions as a preventative treatment against a disease, pathology,
or disorder, or
as a treatment that inhibits or reduces further development or enhancement of
a disease,
pathology or disorder. A "prophylactic activity" is an activity of an agent
that, when
administered to a subject who does not display signs or symptoms of, or who
displays only
early signs or symptoms of, a pathology, disease, or disorder, prevents or
decreases the
risk of the subject developing the pathology, disease, or disorder. A
"prophylactically
useful" agent (e.g., nucleic acid or polypeptide) refers to an agent that is
useful in
preventing development of a disease, pathology, or disorder, or useful in
inhibiting or
reducing further development or enhancement of a disease, pathology or
disorder.
A "therapeutic treatment" is a treatment administered to a subject who
displays
symptoms or signs of pathology, disease, or disorder, in which treatment is
administered
to the subject for the purpose of diminishing or eliminating those signs or
symptoms. A
"therapeutic activity" is an activity of an agent that eliminates or
diminishes signs or
symptoms of pathology, disease or disorder when administered to a subject
suffering from
such signs or symptoms. A "therapeutically useful" agent means the agent is
useful in
decreasing, treating, or eliminating signs or symptoms of a disease,
pathology, or disorder.
Generally, the nomenclature used herein and many of the laboratory procedures
in
cell culture, molecular genetics, molecular biology, nucleic acid chemistry,
and protein
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chemistry described below are well known and commonly employed by those of
ordinary
skill in the art. Standard techniques, such as described in Sambrook et al.,
Molecular
Cloning - A Laboratory Manual (2nd Ed.), Vols. 1-3, Cold Spring Harbor
Laboratory,
Cold Spring Harbor, New York, 1989 (hereinafter "Sambrook") and CURRENT
PROTOCOLS
IN MOLECULAR BIOLOGY, F. M. Ausubel et al., eds., Current Protocols, a joint
venture
between Greene Publishing Associates, Inc. and John Wiley & Sons, Inc. (1994,
supplemented through 1999) (hereinafter "Ausubel"), are used for recombinant
nucleic
acid methods, nucleic acid synthesis, cell culture methods, and transgene
incorporation,
e.g., electroporation, injection, gene gun, impressing through the skin, and
lipofection.
Generally, oligonucleotide synthesis and purification steps are performed
according to
specifications. The techniques and procedures are generally performed
according to
conventional methods in the art and various general references that are
provided
throughout this document. The procedures therein are believed to be well known
to those
of ordinary skill in the art and are provided for the convenience of the
reader.
Various additional terms are defined or otherwise characterized herein.
MOLECULES AND METHODS OF THE INVENTION
The present invention provides molecules and methods for treating diseases,
disorders, and conditions of the immune system, including, e.g., those in
which
modulation of the immune system (e.g., T-cell dependent immune responses) is
desirable.
Molecules of the invention (e.g., polypeptides of the invention, conjugates of
the
invention, soluble fusion proteins of the invention, nucleic acids encoding
such
polypeptides or fusion proteins) are useful for the treatment of immune system
diseases,
disorders, and conditions in which immunosuppression is desirable, including,
e.g., but not
limited to, the treatment of autoimmune diseases, disorders, and conditions,'
immunoproliferative diseases, graft-related disorders, and treatment methods
involving
tissue, cell, organ, or graft transplantation from a donor to a recipient
where suppression of
an immune response in the recipient against the donor tissue, cell, organ, or
graft is
desirable.
In one aspect, the invention provides novel mutant CTLA-4 molecules having
improved properties compared to a CTLA-4 molecule, such as the wild-type human
CTLA-4 polypeptide ("hCTLA-4") or a fragment thereof that binds CD80 and/or
CD86,
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such as the extracellular domain of human CTLA-4 ("hCTLA-4 ECD"). As discussed
in
greater detail below, a variety of mutagenesis and screening strategies were
used to make
and identify novel mutant CTLA-4 molecules that bind CD80 and/or CD86. In
particular,
such strategies were used to make and identify CTLA-4 mutant molecules having
improved binding avid ities for CD80 (B7-1) and/or CD86 (B7-2), as compared to
human
CTLA-4 ("hCTLA-4"), and/or having improved binding affinities for CD80 and/or
CD86,
as compared to the hCTLA-4 ECD. Mutant CTLA-4 molecules of the invention that
bind
endogenous CD80 and/or CD86 ligands expressed on antigen-presenting cells
effectively
inhibit or block the interaction of these ligands with the endogenous CD28
receptor, which
is expressed on the surface of T cells. As a result, the costimulatory signal
critical for T
cell activation provided by the interaction of the T cell surface receptor
CD28 with the B7
molecules (i.e., CD80 and CD86) is inhibited or blocked. Such T cells are not
optimally
activated and have reduced capacities for proliferation.
In instances where signaling between a CD80 or CD86 ligand and a CD28 receptor
is blocked, T cells are not optimally stimulated to become active and thus are
not
optimally induced to proliferate. Similarly, in instances where the signaling
between a
CD80 or CD86 ligand and a CD28 receptor is inhibited, activation and
proliferation of T
cells is inhibited. In one aspect, the invention provides mutant CTLA-4
molecules that
function as antagonists to CTLA-4 signaling. In another aspect, the invention
provides
mutant CTLA-4 molecules that function as antagonists to CD28 signaling,
thereby
suppressing or blocking T cell-dependent immune responses; such molecules
function as
immunosuppressive agents. In yet another aspect, the invention provides mutant
CTLA-4
molecules that bind both CD80 and CD86, but which have higher binding avidity
for
CD86 than for CD80, and therefore inhibit CD86-dependent costimulation to a
greater
extent than CD80-dependent costimulation. All such mutant CTLA-4 molecules of
the
invention are expected to be useful for the treatment of diseases, disorders,
or conditions
in which immunosuppression is desirable or would be of benefit.
A human CTLA-4-Ig fusion protein and a specific mutant CTLA-4-Ig fusion
protein ¨ both developed by Bristol-Myers Squibb Co. (Princeton, NJ) ¨ have
been shown
to be effective in treating certain immune-related diseases or conditions. The
Orencia
fusion protein (also known as Abatacept ("ABA")) (Bristol-Myers Squibb Co.
(Princeton,
NJ)) is a soluble recombinant dimeric fusion protein consisting of two
identical
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monomeric immunoglobulin (1g) fusion proteins covalently linked together by a
disulfide
bond formed between a cysteine residue present in each monomeric fusion
protein.
ORENCIA is a registered trademark of Bristol-Myers Squibb Company. Each
monomeric
Ig fusion protein of the Orencia dimer consists of the extracellular domain
of human
CTLA-4 (SEQ ID NO:159) fused at its C-terminus to the N-terminus of a specific
mutant
IgG1 Fc polypeptide (SEQ ID NO:186). The complete polypeptide sequence of each
such
monomeric fusion protein is shown in SEQ ID NO:164. The Orencia dimer is
produced
in a mammalian expression system and has an apparent molecule weight of 92
kDa. It is
believed that the two monomeric Ig fusion proteins of the Orencia dimer are
covalently
linked together by a single disulfide bond formed between the cysteine residue
at position
120 of each hCTLA-4-mutant IgG1 monomer and that no disulfide bonds are formed
between the two mutant IgG I Fc polypeptides.
The Orencia dimer is a selective costimulation modulator that inhibits T cell
activation by binding to CD80 and CD86 and thus blocking interaction with
CD28. The
Orencia dimer is currently approved for the treatment of human adults
suffering from
moderate to severe rheumatoid arthritis (RA). Additional information about the
Orencia
dimer and its clinical indications and effectiveness is provided on the
worldwide web at
orencia.com and bms.com.
As noted above, each fusion protein monomer of the Orencia dimer contains a
human CTLA-4 extracellular domain. Human CTLA-4 is a membrane protein that is
transiently expressed on T cells. The full-length protein sequence of WT full-
length
hCTLA-4 is shown in SEQ ID NO:160, and a nucleic acid sequence encoding WT
full-
length hCTLA-4 is shown in SEQ ID NO:194. Human CTLA-4 includes a signal
peptide
(SP), extracellular domain (ECD), transmembrane domain (TD), and cytoplasmic
domain
(CD, covalently linked together in that order (e.g., the C-terminus of the SP
is covalently
linked to the N-terminus of the ECD, the C-terminus of the ECD is covalently
linked to
the N-terminus of the TD, and the C-terminus of the TD is covalently linked to
the N-
terminus of the CD). The WT hCTLA-4 ECD polypeptide typically comprises
residues
38-161 of the full-length hCTLA-4 protein sequence (SEQ ID NO:160) and
typically is
124 amino acid residues in length. This hCTLA-4 ECD polypeptide sequence is
shown in
SEQ NO:159. The signal peptide (SP) of the full-length hCTLA-4 protein,
which
typically comprises amino acid residues 1-35 or 1-37 of SEQ ID NO:160, is
cleaved
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during processing. See. e.g., Harper et al., J. Immunol. 147(3):1037-1044
(1991). The
human CTLA-4 signal peptide sequence comprising amino acid residues 1-35 or 1-
37 of
the hCTLA-4 protein is shown in SEQ ID NO:182 or SEQ ID NO:216, respectively.
Whether the signal peptide sequence is that shown in SEQ ID NO:182 or SEQ ID
NO:216,
when the signal peptide is cleaved, the mature hCTLA-4 protein typically
begins with the
methionine residue at amino acid position 38 of the full-length hCTLA-4
protein sequence
shown in SEQ ID NO:160. Thus, even if the hCTLA-4 signal peptide sequence is
that of
SEQ ID NO:182, which comprises amino acid residues 1-35 of the hCTLA-4
protein, the
resulting mature secreted hCTLA-4 protein begins with the methionine that is
at position
38 of the full-length hCTLA-4 protein. The lysine (K) and alanine (A) residues
at
positions 36 and 37, respectively, of the full-length hCTLA-4 protein are not
present in the
mature hCTLA-4 protein and are believed to be cleaved from the mature hCTLA-4
protein
during processing. The amino acid residues of the mature hCTLA-4 protein
sequence thus
are typically numbered beginning with the methionine residue present at
position 38 of the
full-length hCTLA-4 protein as the first amino acid (i.e., occupying position
1);
accordingly, the histidine residue occupies amino acid position 2 in the
mature hCTLA-4
protein, etc. Each monomer of the Orencia dimer includes the hCTLA-4 ECD
polypeptide sequence shown in SEQ ID NO:159. In the full-length WT hCTLA-4
protein,
the signal peptide comprises amino acid residues 1-37, the extracellular
domain (ECD)
comprises amino acid residues 38-161, the transmembrane domain (TD) comprises
amino
acid residues 162-182, and the cytoplasmic domain (CD) comprises amino acid
residues
183-223 of SEQ ID NO:160. The mature domain (MD) of the hCTLA-4 protein
typically
comprises amino acid residues 36-223, or in some instances, amino acid
residues 37-223
or 38-223 of SEQ ID NO:160.
The nucleic acid of SEQ ID NO:194 comprises a nucleic acid sequence encoding
signal peptide sequence (nucleotide residues 1-111), a nucleic acid sequence
encoding
hCTLA-4 ECD (nucleotide residues 112-483), a nucleic acid sequence encoding
the
hCTLA-4 transmembrane and cytoplasmic domains (nucleotide residues 484-669);
the last
3 C-terminal nucleotides are the TGA stop codon.
Belatacept (also known as "LEA29Y-Ig," "LEA-Ig," or "A29YL104E-Ig")
(Bristol-Myers Squibb Co. (Princeton, NJ)) is a soluble recombinant dimeric
protein
composed of two identical Ig fusion proteins covalently linked together by a
disulfide
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bond formed between a cysteine residue in each monomeric fusion protein. Each
monomeric fusion protein is composed of a mutant CTLA-4 extracellular domain
polypeptide fused at its C-terminus to the N-terminus of a specific mutant
IgG1
polypeptide. The polypeptide sequence of the mutant CTLA-4 ECD differs from
the
polypeptide sequence of WT human CTLA-4 ECD by two mutations, specifically a
substitution of a tyrosine for the alanine at position 29 (abbreviated as the
substitution
A29Y) and a substitution of a glutamine for the leucine at position 104
(abbreviated as the
substitution L104E), wherein amino acid residues in the human CTLA-4 ECD are
numbered with the methionine at the N-terminus representing the amino acid at
position 1.
Each monomer of Belatacept includes the mutant IgG1 Fc polypeptide sequence
shown in
SEQ ID NO:186; this mutant IgG1 Fc polypeptide is identical to the mutant IgG1
Fc
polypeptide included in the Orencia fusion protein. Belatacept monomeric
fusion
protein thus differs from each Orencia monomeric fusion protein by two amino
acids.
The polypeptide sequence of each such monomeric fusion protein in Belatacept
is shown
in SEQ ID NO:166. The name "LEA29Y-Ig" thus reflects the fact that each
monomeric
fusion protein of the Belatacept dimer is composed of a mutant CTLA-4 ECD
which
differs from the human CTLA-4 ECD polypeptide sequence by two the mutations
L104E
and A29Y. Belatacept has been shown to bind CD86 about 4 times more avidly and
to
bind CD80 about 2 times more avidly than the Orencia dimer (Larson et al.,
Amer. J.
Transplant. 5:443-453, 444 (2005). Belatacept has been shown to be up to about
10 times
more potent than the Orencia dimer in inhibiting T cell activation in vitro
and to have
improved in vivo immunosuppressive potency compared to the Orencia protein as
shown
by its increased ability to inhibit T cell-dependent antibody responses and
its improved
prolongation of renal allograft survival in clinical trials involving non-
human primates.
Id. Additional information about Belatacept and its clinical indications and
effectiveness
is provided on the worldwide web at bms.com.
In one aspect, the invention provides mutant CTLA-4 molecules, including novel
soluble recombinant mutant CTLA-4-Ig fusion proteins described herein, which
have a
binding avidity for CD86 that is greater than the binding avidity of the
Orencia dimer
(dimeric hCTLA-4-Ig) for CD86. The invention also provides mutant CTLA-4
molecules,
including novel soluble recombinant dimeric mutant CTLA-4-Ig fusion proteins,
which
have a binding avidity for CD80 that is about equal to or greater than the
binding avidity
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of the Orencia dimer for CD80. In yet another aspect, the invention provides
mutant
CTLA-4 molecules, including novel soluble recombinant mutant CTLA-4-Ig fusion
proteins, which have a greater ability to suppress one or more immune
responses (e.g., T
cell-dependent immune responses) than Orencia (Abatacept). Mutant CTLA-4
molecules of the invention having one or more improved properties compared to
the
Orencia dimer are expected to more potent and thus more effective, useful,
and
advantageous than the Orencia dimer in treating diseases, disorders, or
conditions in
which immunosuppression is desirable, including those diseases, disorders, or
conditions
for which the Orencia dimer is approved and/or has been shown to provide
clinical
benefit, such as autoimmune diseases, including, e.g., rheumatoid arthritis
and psoriasis.
In another aspect, the invention provides mutant CTLA-4 molecules, including
novel soluble recombinant mutant CTLA-4-Ig fusion proteins described herein,
which
have a binding avidity for CD86 that is greater than the binding avidity of
Belatacept
(LEA29Y-Ig) for CD86. The invention also provides mutant CTLA-4 molecules,
including novel soluble recombinant mutant CTLA-4-Ig fusion proteins described
herein,
which have a binding avidity for CD86 that is greater than the binding avidity
of
Belatacept for CD86. In another aspect, the invention provides mutant CTLA-4
molecules, including novel soluble recombinant mutant CTLA-4-Ig fusion
proteins
described herein, which have a greater ability to suppress one or more immune
responses
(e.g., T cell-dependent immune responses) than Belatacept. Mutant CTLA-4
molecules of
the invention having one or more improved properties compared to Belatacept
are
expected to more potent than Belatacept and thus more effective, useful, and
advantageous
than Belatacept in treating diseases, disorders, or conditions in which
immunosuppression
is desirable, including those diseases, disorders, or conditions for which the
Belatacept
fusion protein has been shown to provide clinical benefit, such as renal
allograft survival
in non-human primates.
The safety, tolerability, pharmacokinetics, immunogenicity, and clinical
efficacy of
a molecule of the invention, such as a mutant CTLA-4 molecule of the
invention, (e.g.,
mutant CTLA-4 ECD polypeptide or soluble mutant CTLA-4-Ig fusion protein as
described in detail below) in a subject having an immune disease or disorder
(e.g.,
rheumatoid arthritis, multiple sclerosis, psoriasis, etc.) to whom a
particular dose of the
molecule is administered in a particular manner (e.g., parenteral,
intravenous, or
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subcutaneous administration) can be determined using methodologies comparable
to those
employed in clinical trials for Orencia involving similar subjects. See,
e.g., the
worldwide website addresses at bms.com and orencia.com. For example, the
degree to
which a mutant CTLA-4 molecule of the invention (e.g., soluble mutant CTLA-4-
Ig) is
effective in reducing in subjects having rheumatoid arthritis (RA) the
progression of joint
damage, in alleviating the signs and symptoms of RA, including pain reduction,
can be
evaluated using methodologies similar to those employed in the Orencia
clinical trials
involving RA patients.
The safety, tolerability, pharmacokinetics, immunogenicity, and clinical
efficacy of
a molecule of the invention (e.g., mutant CTLA-4 ECD polypeptide or soluble
mutant
CTLA-4-Ig fusion protein as described in detail below) in a subject in which
immunosuppression is desirable (e.g., a subject undergoing tissue, cell,
organ, or graft
transplantation from a donor) and to whom a particular dose of the molecule is
administered in a particular manner (e.g., parenteral, intravenous, or
subcutaneous
administration) can be determined using methodologies comparable to those
employed in
clinical trials for Belatacept involving similar subjects. See, e.g., the
worldwide website
address bms.com. For example, the degree to which a mutant CTLA-4 molecule of
the
invention (e.g., soluble mutant CTLA-4-Ig) is effective in reducing in kidney
or renal
transplant rejection in a recipient patient undergoing kidney or renal
transplantation can be
evaluated using methodologies similar to those employed in the Belatacept
clinical trial
involving patients undergoing kidney or renal transplantation.
Molecules and methods of the invention and other aspects of the invention are
discussed in additional detail below.
POLYPEPTIDES OF THE INVENTION
The present invention provides novel polypeptides, collectively referred to as
"polypeptides of the invention." The term "polypeptides of the invention" is
intended to
include variants and/or derivatives of the polypeptide sequences disclosed
herein.
Polypeptides of the invention include recombinant non-naturally occurring or
mutant
CTLA-4 polypeptides that bind CD80 and/or CD86 and/or that inhibit or suppress
immune
responses. Polypeptides of the invention include recombinant fusion proteins
comprising
a mutant CTLA-4 polypeptide of the invention, and include monomeric and dimer
forms
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of such fusion proteins. Polypeptides of the invention include multimers
comprising one
or more mutant CTLA-4 polypeptides of the invention. The invention also
includes
conjugates comprising one or more mutant CTLA-4 polypeptides of the invention.
Some
polypeptides of the invention are soluble polypeptides. For example, as
described in more
detail below, the invention includes soluble fusion proteins comprising a
mutant CTLA-4
ECD polypeptide linked to a different polypeptide (such as, e.g., an
immunoglobulin
polypeptide, such as, e.g., an ig Fc polypeptide) that enhances solubility of
the mutant
CTLA-4 ECD polypeptide.
As discussed in greater detail below, in one aspect of the invention, a
variety of
mutagenesis and screening strategies were used to make and identify novel
polypeptides
that bind CD80 and/or CD86. In particular, such strategies were used to make
and identify
novel polypeptides having improved abilities to bind CD80 and/or CD86,
including novel
mutant CTLA-4 polypeptides having improved binding affinities or avidities for
CD80
and/or CD86. Polypeptides of the invention that bind CD80 and/or CD86 ligands
expressed on antigen-presenting cells interfere with or block the interaction
of these
ligands with the CD28 receptors expressed on T cells. As a result, the T cell
costimulatory
signal provided by the interaction of the T cell surface receptor CD28 with
the B7
molecules (i.e., CD80 and CD86) is inhibited or blocked. Such polypeptides are
believed
useful in the prophylactic and therapeutic treatment of diseases, disorders,
and conditions
in which modulation of the immune system (e.g., T cell responses) is of
benefit.
Mutant CTLA-4 Polypeptides
In one aspect, the invention provides isolated or recombinant polypeptides
which
each comprise a polypeptide sequence that has at least 75%, 80%, 85%, 86%,
87%, 88%,
89%, 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%,
96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, or 100% sequence identity to
at least
one polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73
(e.g.,
SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID
NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11,
SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ
lD NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID
NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27,
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SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ
ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID
NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43,
SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ ID NO:48, SEQ
ID NO:49, SEQ ID NO:50, SEQ ID NO:51, SEQ ID NO:52, SEQ II) NO:53, SEQ ID
NO:54, SEQ ID NO:55, SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:59,
SEQ ID NO:60, SEQ ID NO:61, SEQ ID NO:62, SEQ ID NO:63, SEQ ID NO:64, SEQ
ID NO:65, SEQ ID NO:66, SEQ ID NO:67, SEQ ID NO:68. SEQ ID NO:69, SEQ ID
NO:70, SEQ ID NO:71, SEQ ID NO:72, and SEQ ID NO:73), wherein the polypeptide
binds CD80 and/or CD86 or a polypeptide fragment of CD80 and/or CD86 (or an
ECD of
either or both), and/or modulate or regulate an immune response. Some such
polypeptides, such as each of those set forth in SEQ ID NOS:1-73, are
described as
secreted or mature mutant CTLA-4 ECD polypeptides. The mutant CTLA-4 ECD
polypeptides set forth in each of SEQ ID NO:1-73 do not include a signal
peptide; it has
been cleaved during processing, thereby producing the mature or secreted
polypeptide. A
polypeptide fragment of CD80 may comprise, e.g., an extracellular domain
polypeptide of
a CD80 polypeptide, such as, e.g., human CD80 ECD polypeptide ("hCD80 ECD"). A
polypeptide fragment of CD86 may comprise, e.g., an extracellular domain
polypeptide of
a CD86 polypeptide, such as, e.g., human CD86 ECD polypeptide ("hCD86 ECD-).
Some such polypeptides bind a mammalian CD80 and/or CD86 or polypeptide
fragment
thereof, such as, e.g., a mammalian CD80 or CD86 ECD. Some such polypeptides
bind
WT human CD80 ("hCD80") and/or WT human CD86 ("hCD86") or a polypeptide
fragment thereof, such as, e.g., hCD80 ECD or hCD86 ECD. In some such methods,
at
least one immune response is suppressed or inhibited.
Some such polypeptides have a binding affinity or avidity for hCD80 or a
fragment
thereof (e.g., hCD80 ECD) that is at least about equal to or greater than the
binding
affinity or avidity of the hCTLA-4 ECD polypeptide for hCD80 or a fragment
thereof,
respectively. The predicted full-length hCD80 polypeptide sequence, which
includes a
signal peptide. ECD, transmembrane domain, and cytoplasmic domain covalently
linked
together in that order, is set forth in SEQ ID NO:195. The signal peptide
comprises amino
acid residues 1-34, the ECD comprises amino acid residues 35-242, the
transmembrane
domain comprises amino acid residues 243-263, and the cytoplasmic domain
comprises
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amino acid residues 264-288 of SEQ ID NO:195. The polypeptide sequence of the
hCD80
ECD is shown in SEQ ID NO:174. The nucleic acid sequence shown in SEQ ID
NO:173
encodes the WT human CD80 signal peptide (at N-terminus) and human CD80 ECD.
Some such polypeptides have a binding affinity or avidity for hCD86 or a
fragment
thereof (e.g., hCD86 ECD) that is at least about equal to or greater than the
binding
affinity or avidity of the hCTLA-4 ECD polypeptide for hCD86 or a fragment
thereof
(e.g., ECD), respectively. The predicted full-length hCD86 polypeptide
sequence, which
includes a signal peptide, ECD, transmembrane domain, and cytoplasmic domain
covalently linked together in that order, is set forth in SEQ ID NO:175, and
an exemplary
nucleic acid encoding the predicted full-length hCD86 polypeptide sequence is
shown in
SEQ ID NO:176. The polypeptide sequence of the hCD86 ECD is shown in SEQ ID
NO:180. Some such polypeptides have a binding affinity or avidity for hCD86
that is at
least about equal to or greater than the binding affinity or avidity of the
LEA29Y ECD
polypeptide having the sequence set forth in SEQ ID NO:168 for hCD86.
Exemplary
polypeptides of the invention that have binding affinities or binding
avidities for hCD86 or
hCD86 ECD that are at least equal to or greater than those of hCTLA-4 ECD and
LEA29Y ECD (also termed "A29YL104E" or "L104EA29Y" ECD) for hCD86 or hCD86
ECD, respectively, include, e.g., but are not limited to, those comprising a
polypeptide
sequence having at least 95%, 96%, 97%, 98%, 99% or 100% sequence identity to
the
sequence of any of SEQ ID NOS:4, 10-12, 15, 17, 24,26, 28, 35, and 61. See,
e.g., Table
5 in Example 4. The data presented in Table 5 reflect a monomeric interaction
between a
representative CTLA-4-Ig and monomeric CD86 ECD. The term LEA29Y (or
A29YL104E or L104EA29Y), if not otherwise indicated, refers to LEA29Y ECD (or
A29YL104E or L104EA29Y ECD).
Some such polypeptides comprise a polypeptide sequence having an amino acid
length about equal to the amino acid length of the human CTLA-4 extracellular
domain.
Such polypeptides may be described as mutant CTLA-4 ECD polypeptides. Some
such
mutant CTLA-4 ECD polypeptides comprise a polypeptide sequence that is about
110
amino acids to about 138 amino acid residues, about 112 to about 136 amino
acid residues,
about 114 to about 134 amino acid residues, about 116 to about 132 amino acid
residues,
about 118 to about 130 amino acid residues, about 119 to about 129 amino acid
residues,
about 120 to about 128 amino acid residues, about 121 to about 127 amino acid
residues,
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about 122 to about 126 amino acid residues, about 123 to about 125 amino acid
residues in
length. Some such mutant CTLA-4 ECD polypeptides comprise a sequence that is
124
amino acid residues in length. Exemplary polypeptides include, e.g., but are
not limited
to, a polypeptide comprising a polypeptide sequence having at least 90%, 91%,
92%, 93%,
94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to at least one
polypeptide
sequence selected from the group consisting of SEQ ID NOS:1-73, wherein such
polypeptide binds CD80 and/or CD86 (or an ECD of either or both).
Some such polypeptides described above, including, e.g., those isolated or
recombinant polypeptides which each comprising a polypeptide sequence having
at least
75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,
98%, 99%, 99.5%, or 100% sequence identity to at least one polypeptide
sequence
selected from the group of SEQ ID NOS:1-73 and which bind CD80 and/or CD86
and/or
an ECD thereof, have an ability to modulate or regulate an immune response.
One or
more of a variety of immune responses may be modulated or regulated by such
polypeptides of the invention, including, but not limited to, e.g., T cell
activation or
proliferation, cytokine synthesis or production (e.g., production of TNF-a,
IFN-y, IL-2,
etc.), induction of various activation markers (e.g., CD25, IL-2 receptor,
etc.), synthesis or
production of inflammatory molecules, inflammation, joint swelling, joint
tenderness,
pain, stiffness, serum levels of C-reactive protein, anti-collagen antibody
production,
and/or T cell-dependent antibody response(s)). In some instances, such a
polypeptide has
a greater ability to suppress or inhibit at least one such immune response
than hCTLA-4 or
hCTLA-4 ECD.
For example, some such polypeptides are capable of inhibiting T cell
activation or
T cell proliferation in in vitro assays. Examples 4-9 set forth below, for
example,
demonstrate the ability of representative fusion proteins of the invention
comprising a
representative mutant CTLA-4 ECD polypeptide sequence, such as those described
herein,
to inhibit T cell proliferation in vitro. Some such polypeptides are capable
of inhibiting or
suppressing an immune response in a subject in vivo, such as through the
administration of
a therapeutically or prophylactically effective amount of at least one such
polypeptide to a
subject needing immunosuppressive therapy. Some such polypeptides are expected
to be
useful in a variety of applications, including, e.g., but not limited to,
prophylactic and/or
therapeutic methods for treating immune system diseases, disorders, and
conditions in
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which immunomodulation is desirable, as discussed in greater detail infra.
Such
polypeptides are expected to be useful in prophylactic and/or therapeutic
methods for
inhibiting or suppressing an immune response in a subject (e.g., in the in
vivo treatment of
immune system diseases or disorders of mammals, such as e.g., humans, in which
immunoinhibition or immunosuppression is desirable), methods for inhibiting
rejection of
a tissue or organ transplant from a donor by a recipient (e.g., by a mammal,
such as, e.g., a
human), and other methods described elsewhere herein.
Additionally or alternatively, some such polypeptides have an ability to
suppress or
inhibit an immune response that is at least about equal to or greater than the
ability of
hCTLA-4 or hCTLA-4 ECD to suppress or inhibit one or more types of immune
responses. For example, some such polypeptides have an ability to inhibit T
cell
activation or proliferation in in vitro and/or in vivo assays and/or
applications, such as
those described above and in greater detail below, which is at least about
equal to or
greater than the ability of hCTLA-4 or hCTLA-4 ECD to inhibit T cell
activation or
proliferation in such applications. Additionally, some such polypeptides have
an ability to
inhibit or suppress an immune response (e.g., T cell activation or
proliferation, cytokine
production, T cell-dependent antibody response) that is greater than the
ability of a
LEA29Y polypeptide ¨ a specific mutant CTLA-4 ECD comprising the polypeptide
sequence shown in SEQ ID NO:168 ¨ to inhibit or suppress an immune response.
Examples 4-9 set forth below, for example, compare the ability of
representative fusion
proteins of the invention comprising a mutant CTLA-4 ECD polypeptide sequence
of the
invention to inhibit T cell proliferation in vitro relative to the ability of
a fusion protein
comprising the hCTLA-4 ECD or LEA29Y polypeptide to inhibit T cell
proliferation in
vitro. Such molecules are expected to be of beneficial use in a variety of
therapeutic
applications, including treatment of autoimmune diseases and disorders, and
prophylactic
and therapeutic methods for inhibiting rejection of organ, cell, or tissue
graft
transplantation.
Some such polypeptides may differ from one another by, e.g., an amino acid
deletion, addition and/or substitution. An amino acid substitution may be a
conservative
or non-conservative substitution. See, e.g., the section entitled "Sequence
Variation."
In another aspect, the invention also provides isolated or recombinant
polypeptides
which each comprise a polypeptide sequence having at least 95%, 96%, 97%, 98%,
99%,
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or 100% sequence identity to at least one polypeptide sequence selected from
the group
consisting of SEQ ID NOS:1-73, wherein the polypeptide binds a monomeric hCD80
or
monomeric hCD86 or an ECD of either or both. Some such polypeptides have (1) a
binding affinity for monomeric hCD86 that is about equal to or greater than
the binding
affinity of monomeric hCTLA-4 or an LEA29Y polypeptide for monomeric hCD86 or
an
ECD thereof, and (2) a binding affinity for monomeric hCD80 that is about
equal to or
greater than the binding affinity of monomeric hCTLA-4 for monomeric hCD80.
The
LEA29Y polypeptide comprises the polypeptide sequence of SEQ ID NO:168.
Further,
some such polypeptides have a greater ability to suppress one or more immune
responses
described herein (e.g., T cell activation/proliferation, cytokine
synthesis/production,
induction of activation markers, production of inflammatory molecules,
inflammation,
anti-collagen Ab production, T cell-dependent Ab response) than monomeric
hCTLA-4,
monomeric hCTLA-4 ECD, or LEA29Y polypeptide.
The invention also provides isolated or recombinant polypeptides which each
comprise a polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
sequence identity to at least one polypeptide sequence selected from the group
consisting
of SEQ ID NOS:1-73, wherein the polypeptide has a binding affinity for a hCD86
ECD or
hCD80 ECD that is about equal to or greater than the binding affinity of a
hCTLA-4 ECD
for the hCD86 ECD or hCD80 ECD, respectively. Some such polypeptides have a
binding affinity for the hCD86 ECD that is greater than the binding affinity
of the hCTLA-
4 ECD (SEQ ID NO:159) or the LEA29Y polypeptide (SEQ ID NO:168) for the hCD86
ECD. Some such polypeptides have a binding affinity for the hCD80 ECD that is
greater
than the binding affinity of the hCTLA-4 ECD for the hCD80 ECD. Some such
polypeptides have an ability to suppress an immune response, in some
instances, a greater
ability to suppress one or more immune responses, including those described
above and
throughout, than the hCTLA-4 ECD or the LEA29Y polypeptide.
In another aspect, the invention provides an isolated or recombinant CTLA-4
polypeptide variant comprising a polypeptide sequence which (a) which differs
from a
polypeptide sequence of human CTLA-4 ECD shown in SEQ ID NO:159 in no more
than
15 amino acid residues, no more than 14 amino acid residues, no more than 13
amino acid
residues, no more than 12 amino acid residues, no more than 11 amino acid
residues, no
more than 10 amino acid residues, no more than 9 amino acid residues, no more
than 8
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amino acid residues, no more than 7 amino acid residues, no more than 6 amino
acid
residues, no more than 5 amino acid residues (e.g., no more than 1, 2, 3, 4,
5, 6, 7, 8, 9, 10,
11, 12, 13, or 14 amino acid residues). and (b) wherein the amino acid residue
at position
24, 30, 32, 39, 41, 50, 54, 55, 56, 64, 65, 70, 85, 104 or 106 of the hCTLA-4
ECD
polypeptide sequence (SEQ ID NO:159) is substituted with a different amino
acid residue
in the CTLA-4 polypeptide variant sequence, wherein amino acid residue
positions of the
CTLA-4 polypeptide variant are numbered according to SEQ ID NO:159, and
wherein the
CTLA-4 polypeptide variant has an ability to bind CD80 or CD86 or an
extracellular
domain or fragment of either, and/or has an ability to suppress or inhibit an
immune
response. Some such variants comprise one or more (e.g., one, two, three,
four, five, six,
seven, eight, nine, ten, eleven, twelve, thirteen, fourteen or fifteen) amino
acid
substitutions selected from the group consisting of A24E, A24S, S25A, G27H,
K28N,
T3ON, T30D, T30A, V32I, Q39K, Q39E, D41G, D41N, D41S, A50M, A50G, M54K,
M54E, M54V, G55E, G55K, N56D, D63K, S64P, 165S, 165F, 165T, S70F, M85A, M85V,
M85A, L104E, L104D, and 1106M, 1106F, and 1106L.
In another aspect, the invention provides an isolated or recombinant mutant
CTLA-
4 polypeptide comprising a polypeptide sequence which (a) differs from the
polypeptide
sequence of the extracellular domain of human CTLA-4 shown in SEQ ID NO:159 in
no
more than 12 amino acid residues (e.g., no more than 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, or 12
amino acid residues), and (b) comprises two, three, four, five, six, seven,
eight, nine, ten,
eleven, or 12 amino acid substitutions selected from the group consisting of
amino acid
positions corresponding to amino acid positions 24, 30, 32, 50, 54, 55, 56,
64, 65, 70, and
104 of SEQ ID NO:159, wherein amino acid positions of the mutant CTLA-4
polypeptide
are numbered according to SEQ ID NO:159, and wherein the mutant CTLA-4
polypeptide
has an ability to bind CD80 or CD86 or an extracellular domain or fragment of
either,
and/or has an ability to suppress or inhibit an immune response. Exemplary
amino acid
substitutions in these positions include, but are not limited to, conservative
amino acid
substitutions of the amino acid residues present in WT hCTLA-4 ECD and/or
A24S/E
(that is, A24S or A24E), T3ON/D/A (that is, T3ON or T3OD or T30A), V32I/L/MN,
A50M/G. M54EN/K, G55E/K/R, N56D/A, S64P/M/C, I65S/T/FN, S70F/Y/W,
L104E/M, or any combination of substitutions thereof.
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In another aspect, the invention provides isolated or recombinant polypeptides
(e.g.. mutant CTLA-4 ECD polypeptides) which each comprise a polypeptide
sequence (a)
which differs from a polypeptide sequence selected from the group consisting
of SEQ ID
NOS:1-73 in no more than 14, 13, 12, 11, 10, 9, 8, 7, 6, 5,4, 3, 2, or 1 amino
acid
residue(s), and (b) wherein the amino acid residue in the polypeptide sequence
at amino
acid residue position 41, 50, 54, 55, 56, 64, 65, 70, or 85 is identical to
the amino acid
residue at the corresponding position of said selected polypeptide sequence
(e.g., a
= polypeptide selected from SEQ ID NOS:1-73), wherein the polypeptide binds
CD80
and/or CD86 and/or an extracellular domain of either or both, and/or inhibits
an immune
response(s). In some instances, the polypeptide differs from the selected
polypeptide (e.g.,
selected from SEQ ID NOS:1-73) in no more than 10, 9, 8, 7, or 6 amino acid
residues
(e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid residues), but
the amino acid
occupying one or more of amino acid residue positions 41, 50, 54, 55, 56, 64,
65, 70, and
85 is identical to the amino acid residue included at that position in the
selected
polypeptide sequence (e.g., one selected from SEQ NOS:1-73) and is not deleted
or
substituted with another amino acid. Some such polypeptides comprise a
polypeptide
sequence which differs from the selected polypeptide sequence in no more than
10, 9, 8, 7,
or 6 amino acid residues (e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10
amino acid
residues) and which includes amino acid residues at one or more of amino acid
residue
positions 24, 30, 32, 41, 50, 54, 55, 56, 64, 65, 70, 85, 104 and 106 that are
identical to the
amino acid residues at the corresponding positions in the selected polypeptide
sequence.
Such polypeptides can differ from the selected polypeptide sequence by amino
acid
deletion(s), addition(s), and/or amino acid substitution(s) at a position(s)
that are not
specified as having an amino acid identical to that of the selected sequence.
Such
polypeptides having a binding affinity or avidity for hCD86 or a fragment
thereof (e.g.,
hCD86 ECD) that is at least about equal to or greater than the binding
affinity or avidity of
the hCTLA-4 ECD or LEA29Y polypeptide for hCD86 or a fragment thereof (e.g.,
ECD),
respectively, are included. Some such polypeptides have a binding affinity or
avidity for
hCD80 or a fragment thereof (e.g., hCD80 ECD) that is at least about equal to
or greater
than the binding affinity or avidity of the hCTLA-4 ECD polypeptide for hCD80
or a
fragment thereof, respectively. Some such polypeptides comprise a polypeptide
sequence
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having a length about equal to the amino acid length of the hCTLA-4 ECD, e.g.,
118-130,
119-129, 120-128, 121-127, 122-126, 123-125, or 124 amino acid residues in
length.
Some such polypeptides are capable of suppressing one or more of a variety of
immune responses, including, e.g.. T cell activation, T cell proliferation,
cytokine
synthesis or production (e.g., production of TNF-a, IFN-y, IL-2), induction of
activation
markers (e.g., CD25, IL-2 receptor), inflammation, production of inflammatory
molecules,
anti-collagen Ab production, and/or T cell-dependent Ab response(s)). Some
such
polypeptides have a greater ability to inhibit one or more such immune
responses than
hCTLA-4, hCTLA-4 ECD polypeptide, or LEA29Y polypeptide. For example, some
such
polypeptides are capable of inhibiting T cell activation or T cell
proliferation in in vitro
assays. Examples 4-9, e.g., compare the ability of representative fusion
proteins of the
invention comprising a mutant CTLA-4 ECD polypeptide sequence of the invention
to
inhibit T cell proliferation in vitro relative to the ability of a fusion
protein comprising the
hCTLA-4 ECD or LEA29Y polypeptide to do so. Some such polypeptides are capable
of
inhibiting or suppressing an immune response in a subject in vivo, such as
through the
administration of a therapeutically or prophylactically effective amount of at
least one
such polypeptide to a subject needing immunosuppressive therapy. Such
polypeptides are
expected to be useful in a variety of applications, including, e.g., but not
limited to,
prophylactic and/or therapeutic methods for treating immune system diseases,
disorders,
and conditions in which suppression of an immune response is desirable,
including, e.g.,
prophylactic and/or therapeutic methods for treating autoimmune diseases and
disorders,
methods for inhibiting rejection of a tissue or organ transplant from a donor
by a recipient
(e.g., by a mammal, such as, e.g., a human), and other methods described
elsewhere
herein.
In another aspect, the invention provides isolated or recombinant polypeptides
(e.g., mutant CTLA-4 ECD polypeptides) which each comprise a polypeptide
sequence
which (a) differs from the polypeptide sequence of the extracellular domain of
human
CTLA-4 shown in SEQ ID NO:159 in no more than 10 amino acid residues, no more
than
9 amino acid residues, no more than 8 amino acid residues, no more than 7,
amino acid
residues, no more than 6 amino acid residues, no more than 5 amino acid
residues, no
more than 4 amino acid residues, no more than 3 amino acid residues, no more
than 2
amino acid residues, or no more than 1 amino acid residue (e.g., no more than
1, 2, 3, 4, 5,
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6, 7, 8, 9, or 10 amino acid residues), and (b) comprises at least one amino
acid
substitution at an amino acid residue position corresponding to position 50,
54, 55, 56, 64,
65, 70, or 85 relative to the polypeptide sequence of SEQ ID NO:159, wherein
the
polypeptide binds hCD80 and/or hCD86 and/or an ECD of either or both, and/or
inhibits
an immune response (e.g., T cell activation or proliferation, cytokine
synthesis or
production (e.g., production of TNF-a, IFN-y, IL-2), induction of activation
markers (e.g.,
CD25, IL-2 receptor), inflammation, production of inflammatory molecules, anti-
collagen
Ab production, and/or T cell-dependent Ab response), such as in in vitro
and/or in vivo
methods and/or assays as described in greater detail below. Some such
polypeptides
comprise a polypeptide sequence that is 124 amino acid residues in length.
Some such
polypeptides comprise 2, 3, 4, 5, or 6 amino acid substitutions at positions
relative to the
polypeptide sequence set forth in SEQ ID NO:159 selected from the group
consisting of
amino acid residue position 50, 54, 55, 56, 64, 65, 70, and 85. Some such
polypeptides
further comprise an amino acid substitution at an amino acid residue position
corresponding to position 104 and/or 30 relative to SEQ ID NO:159. Some such
polypeptides comprise at least one amino acid substitution relative to SEQ ID
NO:159 at
position 70 (optionally S70F), position 64 (optionally S64P), position 50
(optionally
A50M/G, e.g.. A50M, A50G), position 54 (optionally M54K/V, e.g., M54K),
position 65
(optionally I65S), position 56 (optionally N56D), position 55 (optionally
G55E/K, e.g.,
G55E, G55K), position 85 (optionally M85A), and/or position 24 (optionally
A24E/S,
e.g., A24E). Any such polypeptide may further comprise an amino acid
substitution
relative to SEQ ID NO:159 at position 104 (optionally L104E/D, e.g., L104E),
position 30
(optionally T3ON/D/A, e.g., T3ON, T3OD, or T30A), and/or position 32
(optionally V32I).
In some instances, the polypeptide comprises one or more substitutions at
amino acid
positions relative to SEQ ID NO:159 selected from the group consisting of
A50M, M54K,
G55E, N56D, S64P, 165 S. and S70F. Some such polypeptides exhibit a binding
affinity
for CD86 (e.g., hCD86) or CD86 ECD (e.g., hCD86 ECD) that is about equal to or
greater
than the binding affinity of a monomeric hCTLA-4 ECD for CD86 or CD86 ECD,
respectively. Some such polypeptides exhibit a binding affinity for CD80
(e.g., hCD80) or
CD80 ECD (e.g., hCD80 ECD) that is greater than the binding affinity of a
monomeric
hCTLA-4 ECD for CD80 or CD80 ECD, respectively.
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Some such polypeptides have an ability to suppress or inhibit one or more
immune
responses (e.g., T cell activation or proliferation, cytokine production,
etc.), such as in
vitro and/or in vivo. Some such polypeptides inhibit one or more such immune
responses
to a greater degree than hCTLA-4, hCTLA-4 ECD, or LEA29Y polypeptide. Such
polypeptides are expected to be of beneficial use in a variety of therapeutic
applications,
including prophylactic and/or therapeutic methods for treating autoimmune
diseases and
disorders, or prophylactic and/or therapeutic methods for inhibiting organ,
cell, or tissue
graft transplantation rejection.
In another aspect, the invention provides isolated or recombinant polypeptides
(e.g., mutant CTLA-4 ECD polypeptides) which each comprise a polypeptide
sequence
which (a) differs from the polypeptide sequence of the extracellular domain of
human
CTLA-4 shown in SEQ ID NO:159 in no more than 6 amino acid residues (e.g., no
more
than 1, 2, 3, 4, 5, or 6 amino acid residues), and (b) comprises one or more
substitutions at
amino acid positions relative to SEQ ID NO:159 selected from the group
consisting of
A50M, M54K, G55E, N56D, S64P, 165S, and S70F, wherein the polypeptide binds
hCD80 and/or hCD86 or an extracellular domain of either or both, and/or
inhibits an
immune response (e.g., T cell activation or proliferation, cytokine synthesis
or production,
induction of activation markers, production of inflammatory molecules,
inflammation,
joint swelling or tenderness, pain, stiffness, serum levels of C-reactive
protein, anti-
collagen Ab production, and/or T cell-dependent Ab response, etc.) in in vitro
assays
and/or in vivo methods. Such polypeptides are expected to be useful in
treating a subject
suffering from a disease, disorder, or condition in which immunosuppressive
therapy
would be of benefit, including, e.g., therapeutic and prophylactic methods for
treating
autoimmune diseases and disorders, and prophylactic and therapeutic methods
for
inhibiting organ, cell, or tissue graft transplantation.
The invention also includes an isolated or recombinant polypeptide which
comprises a polypeptide sequence comprising (i) at least 95%, 96%, 97%, 98%,
99%, or
100% sequence identity to any polypeptide sequence selected from the group
consisting of
SEQ ID NOS:1-73 and (ii) a phenylalanine residue at an amino acid position
corresponding to position 70 of said polypeptide sequence selected from the
group
consisting of SEQ ID NO:1-73, wherein the polypeptide binds hCD80 and/or hCD86
or an
extracellular domain thereof and/or inhibits an immune response (e.g., T cell
activation or
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proliferation, cytokine synthesis or production, induction of activation
markers, production
of inflammatory molecules, inflammation, joint or tenderness, pain, stiffness,
serum levels
of C-reactive protein, anti-collagen Ab production, and/or T cell-dependent Ab
response,
etc.) in in vitro assays and/or in vivo methods. Some such polypeptides
comprise one or
more of the following relative to the selected sequence: a glutamic acid
residue at an
amino acid position corresponding to position 24; an asparagine residue at an
amino acid
position corresponding to position 30; an isoleucine residue at an amino acid
position
corresponding to position 32; a methionine residue at an amino acid position
corresponding to position 50; a lysine residue at an amino acid position
corresponding to
position 54; a glutamic acid residue at an amino acid position corresponding
to position
55; an aspartic acid residue at an amino acid position corresponding to
position 56; a
proline residue at an amino acid position corresponding to position 64; a
serine residue at
an amino acid position corresponding to position 65; and a glutamic acid
residue at an
amino acid position corresponding to position 104. Such polypeptides are
expected to be
of beneficial use in a variety of applications, including methods for treating
autoimmune
diseases and disorders, and methods for inhibiting organ, cell or tissue graft
transplantation.
For example, in one non-limiting aspect, the invention includes an isolated or
recombinant polypeptide (e.g., mutant CTLA-4 ECD) which comprises a
polypeptide
sequence comprising (i) at least 95%, 96%, 97%, 98%, 99%, or 100% identity to
the
polypeptide sequence of SEQ ID NO:24 and (ii) a phenylalanine residue at an
amino acid
position corresponding to position 70 of the polypeptide sequence of SEQ ID
NO:24,
wherein the polypeptide binds hCD80 and/or hCD86 and/or an ECD of either or
both,
and/or inhibits an immune response in vitro and/or in vivo. The polypeptide
may comprise
at least one of the following relative to SEQ ID NO:24: a glutamic acid
residue at position
24; an asparagine residue at position 30; an isoleucine residue at position
32; a methionine
residue at position 50; a lysine residue at position 54; a glutamic acid
residue at position
55; an aspartic acid residue at position 56; a proline residue at position 64;
a serine residue
at position 65; and a glutamic acid residue at position 104.
The invention also includes an isolated or recombinant polypeptide (e.g.,
mutant
CTLA-4 ECD polypeptide) that binds hCD80 and/or hCD86 (and/or an ECD of either
or
both) and/or inhibits an immune response (as described above), e.g., in vitro
and/or in
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vivo, wherein the polypeptide comprises a polypeptide sequence which (a)
differs from the
polypeptide sequence of human CTLA-4 ECD polypeptide shown in SEQ ID NO:159 in
no more than 6 amino acid residues, and (b) comprises at least one amino acid
substitution, wherein said at least amino acid substitution comprises S70F,
wherein amino
acid residue positions are numbered according to SEQ ID NO:159. The
polypeptide may
further comprise at least one amino acid substitution selected from the group
consisting of
A24E, T3ON, V32I, D41G, A50M, M54K, G55E, N56D, S64P, I65S, M85A, L104E, and
1106F. Such polypeptides believed useful in a variety of applications,
including methods
for treating autoimmune diseases and disorders, and methods for inhibiting
organ, cell,
tissue, or graft transplantation.
The invention also includes an isolated or recombinant polypeptide comprising
a
polypeptide sequence which (a) differs from the polypeptide sequence shown in
SEQ ID
NO:31 in no more than 6 amino acid residues, and (b) comprises at least one of
the
following: a methionine residue at a position corresponding to position 50 of
SEQ ID
NO:31, a lysine residue at a position corresponding to position 54 of SEQ ID
NO:31, a
glutamic acid residue at a position corresponding to position 55 of SEQ ID
NO:31, a
proline residue at a position corresponding to position 64 of SEQ ID NO:31, a
serine
residue at a position corresponding to position 65 of SEQ ID NO:31, a
phenylalanine
residue at a position corresponding to position 70 of SEQ ID NO:31, wherein
amino acid
residue positions are numbered according to SEQ ID NO:31, and the polypeptide
binds
CD80 and/or CD86 and/or an ECD of either or both, and/or inhibits an immune
response
as described above in vitro and/or in vivo. The polypeptide may comprise a
glutamic acid
residue at a position corresponding to position 104, an asparagine acid
residue at a position
corresponding to position 30, and/or an isoleucine residue at a position
corresponding to
position 32 of SEQ ID NO:31. Such polypeptides believed useful in a variety of
applications, including methods for treating rheumatic diseases and disorders,
and
methods for inhibiting organ, cell or tissue graft transplantation.
In another aspect, the invention provides an isolated or recombinant
polypeptide
which comprises a polypeptide sequence comprising (i) at least 95%, 96%, 97%,
98%, or
99% sequence identity to a polypeptide sequence selected from the group
consisting of
SEQ ID NOS:36-46 and 55, and (ii) a ,glutamic acid residue at an amino acid
position 55
of said selected polypeptide sequence, wherein the polypeptide binds CD80
and/or CD86
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or an extracellular domain of either or both and/or suppresses an immune
response.
Immune responses that can be suppressed include, e.g., T cell activation or
proliferation,
cytokine synthesis or production (e.g., production of TNF-a, IFN-y, IL-2),
induction of
activation markers (e.g., CD25, IL-2 receptor), inflammation, production of
inflammatory
molecules, anti-collagen Ab production, and/or T cell-dependent Ab response).
Such
polypeptide sequence may further comprise a phenylalanine residue at amino
acid position
70. Such polypeptide sequence may further comprise a proline residue at
position 64
and/or an asparagine residue at position 30. Such polypeptide sequence may
further
comprise a methionine residue at position 50 and/or a lysine residue at
position 54.
In another aspect, the invention provides an isolated or recombinant
polypeptide
which comprises a polypeptide sequence comprising (i) at least 95%, 96%, 97%,
98%, or
99% sequence identity to a polypeptide sequence selected from the group
consisting of
SEQ ID NOS:28, 30, 36-46, 55-57, and 65-73, and (ii) a glutamic acid residue
at an amino
acid position 55 of said selected polypeptide sequence, wherein the
polypeptide binds
CD80 and/or CD86 or an extracellular domain of either or both and/or
suppresses an
immune response, such as T cell activation or proliferation, cytokine
synthesis or
production (e.g., production of TNF-a, IFN-y, IL-2), induction of activation
markers (e.g.,
CD25, IL-2 receptor), inflammation, production of inflammatory molecules, anti-
collagen
Ab production, and/or T cell-dependent Ab response. Such polypeptide sequence
may
further comprise a phenylalanine residue at amino acid position 70. Such
polypeptide
sequence may further comprise a proline residue at position 64 and/or an
asparagine
residue at position 30. Such polypeptide sequence may further comprise a
methionine
residue at position 50 and/or a lysine residue at position 54.
Any polypeptide of the invention described above may further include a peptide
that facilitates secretion of said polypeptide. Thus, in one aspect, the
invention provides
an isolated or recombinant polypeptide comprising (a) any polypeptide as
described above
(e.g., a mutant CTLA-4 ECD described above), and (b) a peptide that
facilitates secretion
of the expressed polypeptide from a host cell. The peptide is optionally a
signal peptide.
The C-terminus of the signal peptide is typically covalently linked to the N-
terminus of the
polypeptide. The signal peptide may comprise an amino acid sequence having at
least
90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to
the amino acid sequence of SEQ ID NO:182 or SEQ ID NO:216. The signal peptide
may
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comprise an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%,
96%,
97%, 98%, 99%, or 100% identity to an amino acid sequence comprising amino
acid
residues 1-35, 1-36, or 1-37 of SEQ ID NO:160.
Any polypeptide of the invention described above may further comprise a
transmembrane domain and/or cytoplasmic domain. Thus, in one aspect, the
invention
provides an isolated or recombinant polypeptide comprising (a) any polypeptide
of the
invention described above (e.g., a mutant CTLA-4 ECD described above), and (b)
a
transmembrane domain. Such protein may optionally further comprise a signal
peptide as
described above, wherein the C-terminus of the signal peptide is covalently
linked to the
N-terminus of the polypeptide of the invention. The C-terminus of the signal
peptide is
typically covalently linked to the N-terminus of the transmembrane domain. The
C-
terminus of the transmembrane domain is typically covalently linked to the N-
terminus of
the cytoplasmic domain. In some instances, the transmembrane domain comprises
an
amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,
98%,
99%, or 100% identity to an amino acid sequence comprising amino acid residues
162-182
of SEQ ID NO:160. In some instances, the cytoplasmic domain comprises an amino
acid
sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or
100% identity to an amino acid sequence comprising amino acid residues 183-223
of SEQ
ID NO:160. Any of the above-described polypeptides may comprise one or more of
the
amino acid residues that are glycosylated or pegylated.
The invention also includes isolated or recombinant polypeptide multimers
comprising two or more polypeptides, wherein at least one of the polypeptides
of the
multimer is a mutant CTLA-4 polypeptide of the invention as described herein
(e.g., a
mutant CTLA-4 ECD or mutant CTLA-4-Ig). Such a multimer comprises at least one
polypeptide of the invention and may further comprise at least one additional
polypeptide
that need not be a polypeptide of the invention. For example, the multimer may
comprise
at least one polypeptide of the invention and at least one other polypeptide
which may be,
e.g., a wild-type polypeptide (e.g., hCTLA-4 ECD or hCTLA-4-Ig) and/or at
least other
mutant polypeptide (such as a mutant polypeptide that is not a polypeptide of
the
invention). Some or all of the polypeptides in the multimer (or multimeric
polypeptide)
may be identical to one another, or, in some instances, all polypeptides in
the multimer
may be different from one another. In some instances, the polypeptide multimer
is a dimer
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comprising two polypeptides of the invention, which optionally may be
identical
polypeptides (i.e., homodimer) or different polypeptides (i.e., heterodimer).
In some
instances, the polypeptide multimer is a tetramer comprising four polypeptides
of the
invention. The tetramer can comprise four identical polypeptides (i.e.,
homotetramer) or
any combination of four polypeptides of the invention such that at least one
polypeptide is
not identical to the other three polypeptides (i.e., heterotetramer). The
invention also
includes a tetramer comprising four identical WT CTLA-4 ECD polypeptides
(e.g.,
hCTLA-4 ECD) or four identical WT CTLA-4-Ig (e.g., hCTLA-4-Ig). In some
instances,
the multimer is capable of binding CD80 and/or CD86 (or an ECD of either or
both)
and/or suppressing or inhibiting an immune response in in vitro and/or in vivo
methods
(e.g., T cell proliferation or activation, cytokine production, etc.). Some
such multimers
have a greater ability to suppress or inhibit an immune response in vitro
and/or in vivo
than hCTLA-4 or hCTLA-4-Ig (e.g., hCTLA-4-IgG2 or Orencia protein). The
polypeptides of the multimers may be linked together, such as by covalent
linkages, such
as via disulfide bonds between one or more cysteine residues in the one or
more
polypeptides.
Some such tetramers of the invention comprise a structure schematically
similar to
that of an antibody, but in which the variable domains of the antibody are
each replaced
with any mutant CTLA-4 ECD polypeptide of the invention described herein. The
heavy
chain of an antibody comprises a heavy chain variable domain (VH) fused to an
immunoglobulin (Ig) CH1 domain (e.g., IgG2 CH1), which is fused to a hinge.
The hinge
is fused to an Ig CH2 domain (e.g., IgG2 CH2), which is fused to an Ig CH3
domain (e.g.,
IgG2 CH3). The light chain of an antibody comprises a light chain variable
domain (VL)
fused to an Ig C kappa (CO or C lambda (CA) domain. Two heavy chains and two
light
chains are covalently linked together by one or more disulfide bonds formed
via cysteine
residues in the heavy and light chains. The invention includes a mutant CTLA-4
tetramer
in which each of the variable domains of the heavy and light chains is
replaced with a
mutant CTLA-4 ECD polypeptide of the invention. Thus, such tetramer comprises
two
light chains and two heavy chains. Each light chain comprises a mutant CTLA-4
ECD
polypeptide fused to an Ig C,, or C) domain. Each heavy chain comprises a
mutant CTLA-
4 ECD fused to an Ig CH1 domain (e.g., IgG2 CHI), which is fused to a hinge.
The hinge
is fused to an Ig CH2 domain (e.g., IgG2 CH2), which is fused to an Ig CH3
domain (e.g.,
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IgG2 CH3). The two heavy chains and two light chains are covalently linked
together by
one or more disulfide bonds formed via cysteine residues in the heavy and
light chains.
Such tetramer may be described as a CTLA-4-Ig tetramer. Methods for
constructing such
CTLA-4-Ig tetramer are known and would be understood by those of ordinary
skill in the
art. A tetrameric CD4-Ig construct, which comprises a CD4 polypeptide and
which
neutralizes primary HIV type 1 isolates, is described in Allaway, G.P. et al.,
AIDS Res.
Hum. Retroviruses 11(5):533-9 (1995). The tetramer can comprise four identical
four
mutant CTLA-4 ECD polypeptides or any combination of four mutant CTLA-4 ECD
polypeptides of the invention such that at least one mutant CTLA-4 ECD is not
identical to
the other three mutant CTLA-4 ECD polypeptides. Some such tetramers are
capable of
binding CD80 and/CD86 with a higher binding avidity than hCTLA-4 (or hCTLA-4-
Ig).
Some such tetramers are capable of suppressing or inhibiting an immune
response; in
some instances, such a tetramer has a greater ability to suppress or inhibit
an immune
response in in vitro assays or in vivo applications (e.g., T cell
proliferation or activation,
cytokine production, etc) than hCTLA-4 or hCTLA-4-Ig (e.g., hCTLA-4-IgG2 or
Orencia ). Multimers of the invention are expected to be of beneficial use in
a variety of
applications, including methods for treating autoimmune diseases and
disorders, and
methods for inhibiting organ, cell, or tissue graft transplantation.
The invention also includes an isolated or recombinant conjugate multimers
comprising two or more conjugates, wherein at least one of the conjugates is a
conjugate
of the invention which comprises a mutant CTLA-4 polypeptide of the invention
(e.g., a
mutant CTLA-4 ECD or mutant CTLA-4-Ig). Some or all of the conjugates in the
multimer may be identical to one another, or all conjugates in the multimer
may be
different from one another. In some instances, the conjugate multimer is a
dimer
comprising two conjugates or a tetramer comprising four conjugates of the
invention.
Some such conjugate multimers are capable of binding CD80 and/CD86 (or an ECD
of
either or both) and/or suppressing or inhibiting an immune response in vitro
and/or in vivo.
Conjugate molecules in multimers may be linked together, such as by covalent
linkages,
such as via disulfide bonds between one or more cysteine residues in the one
or more
conjugates.
The invention includes an isolated or recombinant polypeptide dimer comprising
any two polypeptides of the invention described above (e.g., mutant CTLA-4 ECD
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described above), wherein the dimer has a binding avidity for human CD86 or an
extracellular domain thereof that is about equal to or greater than the
binding avidity of a
dimer comprising two human CTLA-4 extracellular domains for human CD86 or an
extracellular domain thereof, respectively.
The invention includes isolated or recombinant polypeptide dimers comprising
two
polypeptides of the invention described above (e.g., mutant CTLA-4 ECD
described
above), wherein the dimer has a binding avidity for hCD80 or an ECD thereof
that is about
equal to or greater than the binding avidity of a dimer comprising two hCTLA-4
ECD
polypeptides (SEQ ID NO:159) for hCD80 or an ECD thereof, respectively. For
example,
in a non-limiting aspect, the dimer may comprise two polypeptides, wherein
each
polypeptide comprises a polypeptide sequence having at least 95%, 96%, 97%,
98%, 99%,
or 100% identity to a sequence selected from the group consisting of SEQ ID
NOS:1-73,
and each polypeptide binds hCD80 and/or hCD86 and/or inhibits an immune
response. In
another non-limiting aspect, the dimer may comprise two polypeptides, wherein
each
polypeptide differs from the polypeptide sequence of the hCTLA-4 ECD (SEQ ID
NO:159) in no more than 6 amino acid residues and comprises at least one
substitution at
an amino acid position relative to SEQ ID NO:159 selected from the group
consisting of
A50M, M54K, G55E, N56D, S64P, I65S, and S70F; and which polypeptide optionally
further comprises the substitution L104E, and each polypeptide binds hCD80
and/or
hCD86 and/or inhibits an immune response.
In some instances, the dimer has a binding avidity for hCD80 or an ECD thereof
that is about equal to or greater than the binding avidity of a dimer
comprising two
hCTLA-4 ECD polypeptides for hCD80 or an ECD thereof, respectively. In some
instances, the dimer has a binding avidity for hCD86 or an ECD thereof that is
greater than
the binding avidity of a dimer comprising two LEA29Y polypeptides for hCD86 or
an
ECD thereof, respectively, wherein each LEA29Y polypeptide comprises the
polypeptide
sequence shown in SEQ ID NO:168. In some instances, the dimer dissociates from
binding hCD86 or an ECD thereof at a rate that is less than the rate at which
a dimer
comprising two hCTLA-4 ECD polypeptides dissociates from binding hCD86 or an
ECD
thereof, respectively. In some instances, the dimer dissociates from binding
hCD86 or an
ECD thereof at a rate that is less than the rate at which a dimer comprising
two LEA29Y
polypeptides dissociates from binding hCD86 or an ECD thereof, respectively,
wherein
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each LEA29Y polypeptide comprises the polypeptide sequence shown in SEQ ID
NO:168.
In some instances, the dimer associates with hCD86 or an ECD thereof at a rate
that is greater than the rate at which a dimer comprising two hCTLA-4 ECD
polypeptides
associates with hCD86 or an ECD thereof, respectively. In some instances, the
dimer
associates with hCD86 or an ECD thereof at a rate that is greater than the
rate at which a
dimer comprising two LEA29Y polypeptides associates with hCD86 or an ECD
thereof,
respectively, wherein each LEA29Y polypeptide comprises the polypeptide
sequence
shown in SEQ ID NO:168.
In some instances, such dimer comprising a mutant CTLA-4 ECD has a greater
ability to suppress an immune response (e.g., T cell activation or
proliferation, cytokine
production, etc.) than a dimer comprising two human CTLA-4 extracellular
domains or
two LEA29Y polypeptides.
Some such dimers have a CD86 equilibrium dissociation constant (KD) that is
less
than the CD86 equilibrium dissociation constant (KD) of a dimer comprising two
hCTLA-
4 ECD polypeptides or two LEA29Y polypeptides. Some such dimers have a CD86
equilibrium dissociation constant (KD) that is less than the CD86 equilibrium
dissociation
constant (KD) of a dimer comprising two LEA29Y polypeptides, each LEA29Y
polypeptide comprising the polypeptide sequence set forth in SEQ ID NO:168.
Some such multimers comprising at least two polypeptides of the invention
(e.g., a
dimer comprising two mutant CTLA-4 ECD polypeptides of the invention) have an
enhanced ability to suppress an immune response compared to a multimer of full-
length
hCTLA-4 of the same valency (i.e., a multimer comprising the same number of
full-length
CTLA-4 polypeptides). Some such multimers comprising at least two polypeptides
of the
invention have an enhanced ability to suppress an immune response compared to
a
multimer of hCTLA-4 ECCD of the same valency (i.e., a multimer comprising the
same
number of hCTLA-4 ECD polypeptides).
Any polypeptide of the invention described above may further comprise an
additional polypeptide sequence that enhances solubility, such as an
immunoglobulin (Ig)
polypeptide sequence, thereby forming, e.g., a soluble fusion protein, as
discussed in
greater detail infra. Each polypeptide of a polypeptide multimer may further
comprise an
additional polypeptide sequence that enhances solubility, such as an Ig
polypeptide
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sequence, thereby forming, e.g., a soluble fusion protein. Thus, for example,
each
polypeptide of a dimer comprising two or more polypeptides of the invention,
as described
above, may further comprise an additional polypeptide sequence that enhances
solubility,
such as an Ig polypeptide sequence, thereby forming, e.g., a soluble fusion
protein.
Such polypeptides and dimers of the invention are expected to be of beneficial
use
in a variety of applications, including methods for treating autoimmune
diseases and
disorders, and methods for inhibiting organ, cell, or tissue graft
transplantation.
As discussed previously, the mature hCTLA-4 protein sequence typically begins
with the methionine residue at amino acid position 38 of the full-length hCTLA-
4 protein
sequence shown in SEQ ID NO:160, and the amino acid residues of the mature
hCTLA-4
protein sequence are typically numbered beginning with this methionine residue
as the
first amino acid (i.e., occupying amino acid position 1).
Some mutant CTLA-4 polypeptides of the invention (including monomeric and
dimeric fusion proteins and multimeric polypeptides) include at least one
amino acid
substitution at an amino acid position corresponding to an amino acid position
in the
mature hCTLA-4 protein sequence that is outside the classical hCTLA-4/hB7-2
binding
interface (see, e.g., Schwartz et al., Nature 410:604-608 (2001)), including,
but not limited
to, for example, any of amino acid positions 24, 41, 54, 55, 56, 64, 65, 70,
and 85. In
general, one of ordinary skill in the art would not have predicted that an
amino acid
substitution at any of the above-mentioned positions (24, 41, 54, 55, 56, 64,
65, 70, and/or
85) or any combination of one or more substitutions selected from the group of
positions
24, 41, 54, 55, 56, 64, 65, 70, and 85 would have an ability to enhance the
binding affinity
or avidity of hCTLA-4 for hB7-2, would have an enhanced ability to inhibit the
interaction
of CD28-positive with B7-2-positive cells, or would provide a greater ability
to suppress
or inhibit an immune response than, e.g., hCTLA-4 ECD or hCTLA-4-Ig (e.g., T
cell
activation or proliferation, cytokine synthesis or production, induction of
activation
markers, synthesis or production of inflammatory molecules, anti-collagen
antibody
production, T cell-dependent antibody response, and the like). Further, one of
ordinary
skill in the art would not have predicted that a particular amino acid
substitution(s) or
combination of particular amino acid substitutions described herein at any of
the above-
mentioned positions (24, 41, 54, 55, 56, 64, 65, 70, and/or 85) or any
combination of such
positions would have ability to enhance the binding affinity or avidity of
hCTLA-4 for
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hB7-2, have an enhanced ability to inhibit the interaction of CD28-positive
with B7-2-
positive cells, or provide a greater ability to suppress or inhibit an immune
response than,
e.g., hCTLA-4 ECD or hCTLA-4-Ig.
Mutant CTLA-4 Fusion Proteins
The invention also provides novel isolated and recombinant fusion proteins
which
comprise a first polypeptide that is at least one of the polypeptides of the
invention
described above and throughout (such as a mutant CTLA-4 polypeptide of the
invention,
such as, e.g., a mutant CTLA-4 ECD polypeptide) linked or fused to a second
polypeptide,
thereby forming a fusion protein. The second polypeptide typically facilitates
secretion or
expression of the first polypeptide. Exemplary mutant CTLA-4 ECD polypeptides
include
those comprising sequences identified as SEQ ID NOS:1-73. The invention
includes
fusion proteins comprising immunoglobulin (Ig) domains, such as Ig Fc domains,
fused or
attached to biological active moieties of the invention, such as mutant CTLA-4
polypeptides of the invention. Fusion proteins of the invention are believed
useful as
prophylactic and/or therapeutic agents for the prophylactic and/or therapeutic
treatment of
a variety of immune system diseases and disorders and conditions in
immunomodulation
and/or immunosuppression is of benefit, in diagnostic assays, and for the
preparation of
medicaments or agents having immunomodulating and/or immunosuppressive
activities or
properties as discussed in greater detail elsewhere herein.
Fusion proteins of the invention comprising a mutant CTLA-4 polypeptide and an
Ig polypeptide (e.g., Ig Fc) are typically termed mutant CTLA-4-Ig fusion
proteins. Any
of the fusion proteins of the invention, including monomeric and dimeric
fusion proteins
of the invention described in greater detail below and in the Examples, may
comprise as Ig
polypeptide, such as, e.g., an Ig Fc polypeptide, as described herein and
elsewhere above
and below. The second polypeptide may be linked directly to the first
polypeptide. For
example, the N-terminus of the second polypeptide (e.g., an Ig polypeptide,
such as an Ig
Fc polypeptide) may be covalently fused directly to the C-terminus of the
first polypeptide
of the invention (e.g., mutant CTLA-4 ECD polypeptide). Alternatively, the
second
polypeptide may be linked indirectly to the first polypeptide, such as where a
linker amino
acid sequence comprising 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more amino acid
residues is
included between the first and second polypeptides. In instances in which a
linker is
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=
included, the N-terminus of the amino acid linker sequence is typically
covalently fused to
the C-terminus of the first polypeptide (e.g., mutant CTLA-4 ECD), and the N-
terminus of
the second polypeptide (e.g., an Ig polypeptide, such as an Ig Fc) is
typically covalently
fused to the C-terminus of the amino acid linker sequence.
In some instances, the second polypeptide comprises at least a portion of an
Ig
polypeptide, such as, e.g., one or more domains of an Ig heavy chain constant
region. The
second polypeptide may comprise as a hinge region, CH2 domain, and CH3 domain
of an
Ig polypeptide. In some instances, the second polypeptide comprises an Fc
domain of a
WT Ig polypeptide (i.e., WT Ig Fc polypeptide), such as, e.g., an Fc domain of
a WT
human Ig polypeptide (i.e., WT human Ig Fc polypeptide). As discussed
elsewhere, the Ig
polypeptide may be from various species, including, e.g., mammal, e.g., human,
mouse,
non-human primate (e.g., monkey, gorilla), cat, dog, horse, etc., and can be
from various
classes (e.g., IgG, IgM, IgE, etc.) and subclasses (e.g., for IgG include
IgGl, IgG2, IgG4,
etc.), and may comprise an Fc domain or portion of any such Ig polypeptide.
The amino
acid and nucleic acid sequences of Ig polypeptides of such various species are
known in
the art.
In one aspect, the invention provides novel isolated or recombinant fusion
proteins
which each comprise an isolated or recombinant mutant CTLA-4 polypeptide of
the
invention described above (e.g., mutant CTLA-4 ECD) covalently linked or
fused, either
directly or indirectly (via an amino acid linker sequence), at its C-terminus
to the N-
terminus of an Ig Fc polypeptide, i.e., the Fc domain of an Ig polypeptide.
Any of the
fusion proteins of the invention, including monomeric and dimeric mutant CTLA-
4-Ig
fusion proteins of the invention described in greater detail below and in the
Examples,
may comprise as Ig Fc polypeptide as described herein and elsewhere above and
below.
An Ig Fc polypeptide typically comprises the hinge region, CH2 domain and CH3
domain
of the Ig polypeptide. The Ig Fc polypeptide may be derived from various
species,
including, e.g., human, mouse, primate, etc., and may comprise a wild-type Ig
Fc
polypeptide (e.g., WT IgG I, IgG2, or IgG4). Exemplary human IgG Fc
polypeptides
include, e.g., but are not limited to, human IgG 1, human IgG2, human IgG4,
etc. The
polypeptide sequence of exemplary human IgG I Fc is set forth in SEQ ID
NO:185. The
polypeptide sequences of exemplary human IgG2 Fc polypeptides are set forth in
SEQ ID
NOS:184 and 218, respectively. Alternatively, the Ig Fc polypeptide may
comprise a
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mutant Ig polypeptide. For example, a mutant igG1 Fc in which one or more
cysteine
residues have been substituted with another amino acid (e.g., a serine
residue), thereby
eliminating, one or more disulfide bonds formed between two Ig chains, or in
which one or
more proline residues is substituted with another amino acid (e.g., proline)
to reduce
effector function (reduced Fc receptor binding), may be included in a mutant
CTLA-4-Ig
fusion protein. The polypeptide sequence of an exemplary mutant IgG1 Fc
polypeptide is
shown in SEQ ID NO:186. The invention includes an isolated or recombinant
fusion
protein, such as a mutant CTLA-4-Ig dimer or mutant CTLA-4-Ig monomer, which
comprises at least one recombinant mutant CTLA-4 polypeptide described above
linked at
its C-terminus to the N-terminus of a recombinant Ig Fc polypeptide comprising
an amino
acid sequence having at least 95%, 96%, 97%. 98%, 99%, or 100% identity to an
amino
acid sequence selected from the group consisting of SEQ ID NOS:184 (human IgG2
Fc
polypeptide), 185 (human IgG1 Fc polypeptide), 186 (mutant IgG1 Fc
polypeptide), and
218 (human IgG2 Fc polypeptide without C-terminal lysine (K) residue).
In one aspect, the predicted polypeptide sequence of a mutant CTLA-4-Ig fusion
protein of the invention comprises the following segments: a signal peptide
sequence
which facilitates secretion of the fusion protein (e.g., hCTLA-4 signal
peptide (SEQ ID
NO:182 or SEQ ID NO:216)); a mutant CTLA-4 ECD polypeptide, which mutant CTLA-
4 ECD polypeptide typically, but not necessarily, comprises from about 118 to
130 amino
acid residues, and usually about 124 amino acid residues in length; and an Ig
Fc
polypeptide. Exemplary mutant CTLA-4 ECD polypeptides include those described
above and below. In some instances, no amino acid linker sequence is included
between
the C-terminus of the mutant CTLA-4 ECD polypeptide and the N-terminus of the
human
Ig Fc polypeptide; that is, the C-terminus of a mutant CTLA-4 ECD polypeptide
is
covalently fused directly to the N-terminus of the Ig Fc polypeptide in the
mutant CTLA-
4-Ig fusion protein. If desired, however, a mutant CTLA-4-Ig may include a
linker (e.g.,
one or more amino acid residues) between the C-terminus of the mutant CTLA-4
ECD
polypeptide and the N-terminus of the human Ig Fc polypeptide. The signal
peptide of a
predicted monomeric mutant CTLA-4-Ig fusion protein of the invention is
typically
cleaved from the N-terminus of the mutant CTLA-4 Ig fusion protein during
processing
and thus the mature or secreted form of a mutant CTLA-4-Ig fusion protein of
the
invention does not usually include a signal peptide sequence. A fusion protein
dimer
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comprising two such monomeric mutant CTLA-4-Ig fusion proteins is typically
formed
during cellular processing by the creation of covalent disulfide bonds between
(1) cysteine
residues in the mutant CTLA-4 ECD and igG2 Fc of one such monomeric fusion
protein
and (2) cysteine residues in the mutant CTLA-4 ECD and IgG2 Fc of the second
(typically, but not necessarily identical) monomeric fusion protein.
The invention includes dimeric fusion proteins (also termed fusion protein
dimer)
which each comprise two monomeric fusion proteins of the invention. The dimer
may
comprise two identical or different monomeric fusion proteins. The dimeric
fusion protein
is formed by a linkage(s) between the two monomeric fusion proteins. A dimeric
fusion
protein comprising two such monomeric fusion proteins is typically formed
during cellular
processing by the generation of covalent disulfide bonds between cysteine
residues in one
monomeric fusion protein and cysteine residues in the second monomeric fusion
protein.
Thus, in some instances, a mutant CTLA-4-Ig fusion protein of the invention is
expressed
as a dimer comprising two monomeric fusion proteins of the invention.
In one aspect, the invention provides an isolated or recombinant dimeric
mutant
CTLA-4-Ig fusion protein comprising two monomeric fusion proteins, wherein
each
monomeric fusion protein comprises a mutant CTLA-4 ECD polypeptide of the
invention,
as described in detail above and further below, fused at its C-terminus to an
Ig Fe
polypeptide. The dimer is formed during cellular processing by the generation
of covalent
disulfide bonds between cysteine residues in the mutant CTLA-4 ECD and Ig Fc
of one
monomeric fusion protein and cysteine residues in the mutant CTLA-4 ECD and Ig
Fc of
the second monomeric fusion protein. The two monomeric fusion proteins
typically, but
not necessarily, comprise identical sequences. The secreted or mature form of
a mutant
CTLA-4-Ig fusion protein does not include a signal peptide, as the signal
peptide is
typically cleaved from the N-terminus of the protein during processing. The
predicted
mutant CTLA-4-Ig fusion includes a signal peptide, the C-terminus of which is
typically
covalently linked to the N-terminus of the mutant CTLA-4-Ig protein. The N-
terminus of
each monomer of a mature mutant CTLA-4-Ig fusion protein typically comprises a
methionine (M).
As a non-limiting example, the invention provides dimeric fusion proteins
comprising two monomeric CTLA-4-Ig fusion proteins, wherein each monomeric
mutant
CTLA-4-Ig fusion protein comprises a mutant CTLA-4 ECD polypeptide linked at
its C-
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terminus to the N-terminus of an Ig Fc polypeptide, wherein the mutant CTLA-4
ECD
polypeptide comprises a polypeptide sequence selected from any of SEQ ID NOS:1-
73.
In some such dimeric fusion proteins, the two monomeric fusion proteins are
covalently
linked together by a covalent disulfide bond formed during cellular processing
between a
cysteine residue at position 120 in each CTLA-4 mutant ECD polypeptide
sequence.
Alternatively, or in addition, the two monomeric fusion proteins are
covalently linked
together by a covalent disulfide bond formed between one or more cysteine
residues in the
Ig Fc polypeptide of the first monomeric fusion protein and one or more
cysteine residues
in the Ig Fc polypeptide of the second monomeric fusion protein. The monomeric
fusion
proteins may be linked together by multiple disulfide bonds (e.g., one, two,
three, four, or
more disulfide bonds) formed during cellular processing between cysteine
residues present
in their respective Ig Fc polypeptides. In some instances, each monomeric
fusion protein
is comprised of the same Ig Fc polypeptide (e.g., human IgG2 Fc, as shown in,
e.g., SEQ
ID NO:184 or 218), and covalent disulfide bond(s) may be generated during
cellular
processing between cysteine residues at equivalent positions in each Ig Fc
polypeptide.
An exemplary mutant CTLA-4 ECD polypeptide is the D3-12 mutant CTLA-4
ECD polypeptide comprising the polypeptide sequence of SEQ ID NO:11. An
exemplary
mutant CTLA-4-Ig fusion protein of the invention is the D3-12 mutant CTLA-4
ECD
polypeptide covalently linked or fused directly (no linker) at its C-terminus
to the N-
terminus of the human IgG2 Fc polypeptide shown in SEQ ID NO:218, thereby
forming
the D3-12-IgG2 fusion protein shown in SEQ ID NO:205, or covalently linked or
fused
directly (no linker) at its C-terminus to the N-terminus of the human IgG2 Fc
polypeptide
shown in SEQ ID NO:184, thereby forming the D3-12-IgG2 fusion protein shown in
SEQ
ID NO:74. The sequence of SEQ ID NO:74 differs from that of SEQ ID NO:205 by
one
residue ¨ i.e., an additional lysine residue is present at the C-terminus of
SEQ ID NO:74.
We have found experimentally by liquid chromatography mass spectrometry (LCMS)
analysis, or the like, that a mature CTLA-4-Ig fusion protein made in CHO
cells by
transfecting an expression vector comprising a nucleotide sequence encoding a
mutant
CTLA-4 ECD, such as, e.g., the D3-12 ECD polypeptide sequence shown in SEQ ID
NO:11, and the hIgG2 Fc polypeptide shown in SEQ ID NO:184 does not typically
include the predicted C-terminal lysine (K) residue, as would be expected
based on the
hIgG2 Fc sequence shown in SEQ ID NO:184.
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For example, the nucleotide sequence of SEQ ID NO:153 encodes the hCTLA-4
signal peptide and D3-12-IgG2 fusion protein and includes the stop codon TAA
at its C-
terminus. The codon AAA, which codes for a lysine residue, immediately
precedes the
stop codon TAA in the sequence of SEQ ID NO:153. The predicted polypeptide
sequence
of a mature D3-12-IgG2 fusion protein produced by transfecting an expression
vector
comprising the nucleotide sequence of SEQ ID NO:153 into CHO cells is shown in
SEQ
ID NO:74. The signal peptide is absent in the mature form of the D3-12-IgG2
fusion
protein, as it has been cleaved during processing to form the mature fusion
protein.
However, we have found, based on LCMS analysis, that in such instance the
mature D3-
12-IgG2 does not typically include the predicted C-terminal lysine residue, as
would be
expected based on the nucleotide sequence of SEQ ID NO:153. Rather, the
resulting
mature D3-12-IgG2 polypeptide sequence produced by such method is that shown
in SEQ
ID NO:205. The C-terminal lysine of the IgG2 Fe polypeptide is believed to be
cleaved
during processing or prior to secretion.
It is believed that production of D3-12-IgG2 protein using another mammalian
cell
line by transfection of such vector comprising the nucleotide sequence of SEQ
ID NO:153
into such mammalian cell (e.g., COS cells and the like) would produce a
similar D3-12-
IgG2 fusion protein lacking the predicted C-terminal lysine residue by virtue
of analogous
processing or secretion machinery.
The dimeric D3-12-IgG2 fusion protein comprises two such D3-12-IgG2
monomers linked together by one or more disulfide bonds formed during cellular
processing by the generation of covalent disulfide bonds between cysteine
residues. D3-
12-IgG2 and other fusion proteins of the invention can be made, e.g., by using
methods set
forth in Example 3. For example, a nucleic acid sequence encoding a D3-12
polypeptide
(e.g., SEQ ID NO:90) can be cloned into the IgG2 Fe fusion vector, mammalian
cells can
be transfected with the vector, and the resultant fusion protein can be
expressed (typically
in dimeric form), purified, and evaluated as described in Example 3.
Another exemplary mutant CTLA-4 ECD polypeptide is the D3-54 mutant CTLA-
4 ECD polypeptide comprising the polypeptide sequence of SEQ ID NO:36, and an
exemplary mutant CTLA-4-Ig fusion protein comprises the D3-54 mutant CTLA-4
ECD
polypeptide covalently linked or fused directly (no linker) at its C-terminus
to the N-
terminus of the hIgG2 Fe polypeptide shown in SEQ ID NO:218 (without the C-
terminal
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lysine), thereby forming the D3-54-IgG2 fusion protein shown in SEQ ID NO:211,
or
covalently linked or fused directly (no linker) at its C-terminus to the N-
terminus of the
hIgG2 Fc polypeptide shown in SEQ ID NO:184 (with the C-terminal lysine),
thereby
forming the D3-54-IgG2 fusion protein shown in SEQ ID NO:197. As discussed
above,
experimental analysis indicates that the mature D3-54-IgG2 fusion protein made
in CHO
cells does not typically include the predicted C-terminal lysine residue. The
C-terminal
lysine of hIgG2 Fc is believed to be cleaved during processing or prior to
secretion,
resulting in the D3-54-IgG2 fusion protein sequence shown in SEQ ID NO:211.
Further,
as noted above, D3-29-IgG2 can be made by using methods of Example 3. The
dimeric
D3-54-IgG2 fusion protein comprises two D3-54-IgG2 monomers linked together by
one
or more disulfide bonds formed during cellular processing by the generation of
covalent
disulfide bonds between cysteine residues. The nucleic acid sequence shown in
SEQ ID
NO:201 encodes the fusion proteins shown in SEQ ID NOS:197 and 211.
Other fusion proteins of the invention can similarly comprise a mutant CTLA-4
ECD polypeptide linked or fused to hIgG2 (SEQ ID NO:218 or184). Exemplary
mature
mutant CTLA-4-IgG2 fusion proteins of the invention include, e.g., the
polypeptide
sequences of each of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222. Each of
the
polypeptide sequences of SEQ ID NOS:74-79, 197-200, 220, and 222 includes a C-
terminal lysine residue; this C-terminal lysine residue is typically cleaved
during
processing or prior to secretion, resulting in the polypeptide sequences
without the C-
terminal lysine shown in SEQ ID NOS:205-210, 211-214, 219, and 221,
respectively.
Figure 10 is a schematic diagram showing an exemplary configuration or
structure
of an exemplary mutant CTLA-4-IgG2 fusion protein of the invention. Two
identical
monomeric mutant CTLA-4-IgG2 fusion proteins are shown schematically, each
comprising a mature mutant CTLA-4 ECD polypeptide covalently linked at its C-
terminus
to the N-terminus of a human IgG2 Fc polypeptide. Each human IgG2 polypeptide
includes a human IgG2 hinge, CH2 domain, and CH3 domain. Exemplary amino acid
residues present at the junctions between the ECD and Ig Fc polypeptides are
also shown.
The amino acid residues at the junctions between these components may differ
depending
upon the mutant CTLA-4 ECD polypeptide sequence and/or Ig polypeptide
sequence.
This dimeric mutant CTLA-4-IgG2 fusion protein results from the formation of
at least
one disulfide bond between cysteine residues at analogous positions in the two
mutant
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CTLA-4-1gG2 fusion protein monomers. The cysteine (C) residues potentially
involved in
forming disulfide bonds between the two monomers are marked with asterisks.
The signal
peptide of each monomeric fusion protein is typically cleaved during
processing and thus
the secreted (mature) fusion protein typically does not include the signal
peptide sequence.
The polypeptide sequence of the human IgG2 polypeptide, which comprises the
hinge,
CH2 domain, and CH3 domain of human IgG2, is shown in SEQ ID NO:184. In an
alternative aspect, the polypeptide sequence of the human IgG2 polypeptide,
which
comprises the hinge, CH2 domain, and CH3 domain of human IgG2, is shown in SEQ
ID
NO:218; in this instance, the IgG2 polypeptide does not include the C-terminal
lysine (K)
residue, as compared to the sequence of SEQ ID NO:184.
The properties of mutant CTLA-4-Ig fusion proteins of the invention, described
in
detail elsewhere, may be compared to the properties of one or more reference
Ig fusion
proteins, such as, e.g., hCTLA-4-IgG1, hCTLA-4-IgG2, Orencia fusion protein,
and
LEA29Y-Ig. Properties that may be compared include, e.g., ability to bind CD80
and/or
CD86 (and/or CD80-Ig and/or CD86-Ig), and/or ability to inhibit or suppress an
immune
response (e.g., T cell activation or proliferation, cytokine production,
etc.). The mature
hCTLA-4-IgG1 fusion protein typically exists in solution as a hCTLA-4-IgG1
fusion
protein dimer comprising two identical monomeric hCTLA-4-IgG1 proteins, each
monomeric hCTLA-4-IgG1 fusion protein comprising a hCTLA-4 ECD polypeptide
(SEQ
ID NO:159) linked to an IgG1 Fc polypeptide. The mature hCTLA-4-IgG2 fusion
protein
typically exists in solution as an hCTLA-4-IgG2 fusion protein dimer
comprising two
identical monomeric hCTLA-4-IgG2 proteins, each monomeric hCTLA-4-IgG2 fusion
protein (SEQ ID NO:162) comprising an hCTLA-4 ECD polypeptide (SEQ ID NO:159)
linked to an IgG2 Fc polypeptide. The mature Orencia fusion protein is a
fusion protein
dimer comprising two identical monomeric Orencia fusion proteins, each
monomeric
fusion protein (SEQ ID NO:164) comprising a hCTLA-4 ECD polypeptide (SEQ ID
NO:159) linked to a specific mutant IgG1 polypeptide (SEQ ID NO:186). The
mature
LEA29Y-Ig fusion protein typically exists in solution as a LEA29Y-Ig fusion
protein
dimer comprising two identical monomeric LEA29Y-Ig fusion proteins, each
monomeric
LEA29Y-Ig fusion protein (SEQ ID NO:166) comprising a specific mutant CTLA-4
ECD
polypeptide (SEQ ID NO:168) linked to a specific mutant IgG1 polypeptide (SEQ
ID
NO:186). It is believed that the two fusion protein monomers of the Orencia
dimer are
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covalently linked together by a single disulfide bond formed between the
cysteine residue
at position 120 of each hCTLA-4-mutant IgG1 monomer and that no disulfide
bonds are
formed between the two mutant IgG1 Fc polypeptides.
Some mutant CTLA-4 fusion proteins bind CD80 (e.g., hCD80) and/or CD86 (e.g.,
hCD86). Some such mutant CTLA-4-Ig fusion proteins bind a CD80-Ig fusion
protein
and/or a CD86-Ig fusion protein. Exemplary CD80-Ig fusion proteins include the
hCD80-
mIg fusion protein (SEQ ID NO:225), which comprises a human CD80 ECD linked to
a
murine Ig Fc polypeptide; and the hCD80-hIgG1 fusion protein (SEQ ID NO:171),
which
comprises the sequence of hCD80 ECD linked to human IgG1 Fc polypeptide.
Exemplary
CD86-Ig fusion proteins include the hCD86-mIg fusion protein (SEQ ID NO:226),
which
comprises an hCD86 ECD (SEQ ID NO:180) linked to a murine Ig Fc polypeptide;
and
the mature hCD86-hIgG1 fusion protein (SEQ ID NO:178), which comprises the
sequence
of hCD86 ECD (SEQ ID NO:180) linked to the human IgG1 Fc polypeptide (SEQ ID
NO:185). Exemplary nucleic acid sequences encoding hCD86-mIg and hCD80-mIg
fusion proteins are shown in SEQ ID NOS:227 and 228, respectively.
In one aspect, the invention provides an isolated or recombinant fusion
protein
comprising (a) a polypeptide comprising a polypeptide sequence that has at
least 80%,
85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%. 98%, 99%, 99.5%, or 100% sequence
identity to at least one polypeptide sequence selected from the group
consisting of SEQ ID
NOS:1-73, and (b) an Ig Fc polypeptide (e.g., hIgG2 Fc), wherein the fusion
protein binds
CD80 and/or CD86, and/or CD80-Ig and/or CD86-Ig fusion protein, and/or
exhibits an
ability to inhibit or suppress an immune response. The Ig Fc polypeptide may
comprise a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity
to a
polypeptide sequence selected from the group of SEQ ID NO:184, 185, 186, and
218. In
some instances, the C-terminus of the polypeptide of (a) is covalently linked
to the N-
terminus of the Ig Fc polypeptide of (b). Some such mutant CTLA-4-Ig fusion
proteins
bind a mammalian CD80 and/or CD86 (e.g., hCD80 and/or hCD86), and/or a CD80-Ig
and/or CD86-Ig fusion protein. A CD80-Ig may comprise, e.g., a human CD80 ECD
linked to an Ig Fc (e.g., hCD80-Ig). In one embodiment, an hCD80-Ig is a human
CD80
ECD linked to a human Ig Fc (hCD80-hIg); in another embodiment, an hCD80-Ig is
a
human CD80 ECD linked to a murine Ig Fc (hCD80-mIg). In one embodiment, an
hCD86-Ig is a human CD86 ECD linked to a human Ig Fc (hCD86-hIg); in another
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embodiment, an hCD86-Ig is a human CD86 ECD linked to a murine Ig Fc (hCD86-
mIg).
Some such fusion proteins have an ability to inhibit or suppress one or more
of a variety of
immune responses, such as, e.g., T cell activation, T cell proliferation,
cytokine synthesis
or production (e.g., production of TNF-a, IFN-y, IL-2), induction of
activation markers
(e.g., CD25, IL-2 receptor) or inflammatory molecules, inflammation, anti-
collagen Ab
production, and/or T cell-dependent Ab response(s) in in vitro and/or in vivo
assays and/or
methods. Such fusion proteins are expected to be of beneficial use in a
variety of
applications, including methods for treating immune system diseases and
disorders (e.g.,
autoimmune diseases), and methods for inhibiting organ, cell, or tissue graft
transplantation, as discussed below.
In another aspect, the invention provides an isolated or recombinant mutant
CTLA-
4-Ig fusion protein dimer comprising two monomeric mutant CTLA-4-Ig fusion
proteins
linked via at least one disulfide bond formed between two cysteine residues
present in
each monomeric mutant CTLA-4-Ig fusion protein. Each mutant CTLA-4-Ig fusion
protein monomer comprises: (a) a mutant CTLA-4 ECD polypeptide comprising a
polypeptide sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,
98%,
99%, 99.5%, or 100% sequence identity to at least one polypeptide sequence
selected from
the group consisting of SEQ ID NOS:1-73, and (b) an Ig Fc polypeptide (e.g.,
hIgG2 Fc),
wherein the fusion protein dimer binds CD80 and/or CD86. and/or CD80-Ig and/or
CD86-
Ig, and/or exhibits an ability to inhibit or suppress an immune response. In
some
instances, the C-terminus of the polypeptide of (a) is covalently linked or
fused to the N-
terminus of the Ig Fc polypeptide of (b). The Ig Fc polypeptide may comprise a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity
to a
polypeptide sequence selected from the group consisting of SEQ ID NO:184-186
and 218.
In some instances, the fusion protein dimer is formed by a covalent disulfide
bond
between a cysteine residue at amino acid position 120 of each mutant CTLA-4
ECD
polypeptide sequence, or at an amino acid position corresponding to position
120 in each
mutant CTLA-4 ECD polypeptide sequence relative to the hCTLA-4 ECD polypeptide
sequence shown in SEQ ID NO:159. Some such fusion protein dimers have an
ability to
inhibit or suppress one or more of a variety of immune responses, such as,
e.g., T cell
activation, T cell proliferation, cytokine synthesis or production (e.g.,
production of TNF-
a, EFN-y, IL-2), induction of activation markers (e.g., CD25, IL-2 receptor)
or
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inflammatory molecules, inflammation, anti-collagen Ab production, and/or T
cell-
dependent Ab response(s) in in vitro and/or in vivo assays and/or methods.
Such fusion
protein dimers are expected to be of beneficial use in a variety of
applications, including
methods for treating immune system diseases and disorders (e.g., autoimmune
diseases),
and methods for inhibiting organ, cell, or tissue graft transplantation, as
discussed below.
Some such mutant CTLA-4-Ig fusion protein monomers have binding affinities for
hCD86 or hCD86 ECD that are at least equal to or greater than those of hCTLA-4
ECD
and LEA29 for hCD86 or hCD86 ECD, respectively. See, e.g., Table 5 in Example
4.
The mutant CTLA-4 ECD polypeptide present in some such dimeric and monomeric
fusion proteins comprises a polypeptide sequence having an amino acid length
about equal
to the amino acid length of the hCTLA-4 ECD. For example, some such mutant
CTLA-4
ECD polypeptides comprise a polypeptide sequence that is about 110 to 138, 112
to 136,
114 to 134, 116 to 132, 118 to 130, 119 to 129, 120 to 128, 121 to 127, 122 to
126, or 123
to 125 amino acid residues in length. Some such mutant CTLA-4 ECD polypeptides
comprise a sequence of 124 amino acid residues. Exemplary mutant CTLA-4 ECD
polypeptides include, e.g., but are not limited to, those comprising a
polypeptide sequence
having at least 95%, 96%, 97%, 98%, 99% or 100% sequence identity to at least
one
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73,
wherein
such mutant CTLA-4 ECD polypeptide binds CD80 and/or CD86 (or an ECD of either
or
both), and/or has an ability to inhibit an immune response.
Some such mutant CTLA-4-Ig fusion protein dimers have a binding avidity for
hCD86 and/or hCD86-Ig that is at least about equal to or greater than the
binding avidity
of a hCTLA-4-Ig fusion protein dimer (e.g., hCTLA-4-IgG2 or hCTLA-4-IgG1
dimer),
Orencia dimer, and/or LEA29Y-Ig dimer for hCD86 and/or hCD86-I2,
respectively.
Some such fusion protein dimers have a binding avidity for hCD86 and/or hCD86-
mIg
that is 2-10 times (2x-10x), 5-10 times (5x-10x), 10-20 times (10x-20x), 20-40
times (20x-
40x), or more than 40 times (>40x) greater than the binding avidity of Orencia
dimer for
hCD86 and/or hCD86-mIg. See, e.g., exemplary dimeric fusion proteins of the
invention
in Table 3 below. Alternatively or additionally, some such fusion protein
dimers have a
binding avidity for hCD80 and/or hCD80-Ig that is at least about equal to or
greater than
the binding avidity of a hCTLA-4-Ig dimer (e.g., hCTLA-4-IgG2 or hCTLA-4-IgG1
dimer), Orencia dimer, and/or LEA29Y-Ig dimer for hCD80 and/or hCD80-Ig,
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respectively. Some such fusion protein dimers have a binding avidity for hCD80
and/or
hCD80-mIg that is 0.5-2 times (0.5x-2x), 2-4 times (2x-4x), or more than 2
times (>2x)
greater than the binding avidity of Orencia dimer for hCD86 and/or hCD86-mIg.
See,
e.g., exemplary dimeric fusion proteins of the invention in Table 4 below.
Some such mutant CTLA-4-Ig fusion protein dimers dissociate from binding
hCD86 and/or hCD86-Ig at a rate that is less than the rate at which a hCTLA-4-
Ig dimer
(e.g., hCTLA-4-IgG2 or hCTLA-4-IgG1 dimer), Orencia dimer, and/or LEA29Y-Ig
dimer dissociates from binding hCD86 and/or hCD86-Ig, respectively. Some such
fusion
proteins associate with or bind to hCD86 and/or hCD86-Ig at a rate that is at
least equal to
or greater than the rate at which an hCTLA-4-Ig dimer (e.g., hCTLA-4-IgG2 or
hCTLA-4-
IgG1 dimer), Orencia dimer, and/or LEA29Y-Ig dimer associates with hCD86
and/or
hCD86-Ig, respectively. For some such fusion protein dimers, the equilibrium
dissociation constant (KD) for the binding reaction between CD86 (or CD86-Ig)
and the
fusion protein dimer of the invention is less than the equilibrium
dissociation constant
(KD) for the binding reaction between CD86 (or CD86-Ig) and an hCTLA-4-Ig
dimer (e.g.,
hCTLA-4-IgG2 or hCTLA-4-IgG1 dimer), Orencia dimer, and/or LEA29Y-Ig dimer.
See, e.g., exemplary fusion protein dimers of the invention in Table 3. For
some such
fusion protein dimers, the equilibrium dissociation constant (KD) for the
binding reaction
between CD80 (or CD80-Ig) and the fusion protein dimer of the invention is
about equal
to or less than the equilibrium dissociation constant (KD) for the binding
reaction between
CD80 (or CD80-Ig) and a hCTLA-4-Ig dimer (e.g., hCTLA-4-IgG2 or hCTLA-4-IgG1
dimer), Orencia dimer, or LEA29Y-Ig dimer. See, e.g., exemplary fusion
protein dimers
of the invention in Table 4.
Some such mutant CTLA-4-Ig fusion protein dimers have an ability to inhibit or
suppress an immune response (e.g., inhibit T cell activation or proliferation,
inhibit
cytokine production, etc.) that is at least about equal to or greater than the
ability of a
hCTLA-4-Ig dimer (e.g., hCTLA-4-IgG2 or hCTLA-4-IgG1 dimer), Orencia dimer,
and/or LEA29Y-Ig dimer to inhibit or suppress said immune response,
respectively. For
example, some such fusion protein dimers are capable of inhibiting T cell
activation or T
cell proliferation in in vitro assays. Examples 4-9 set forth below, for
example,
demonstrate the ability of representative fusion protein dimers of the
invention comprising
a representative mutant CTLA-4 ECD polypeptide sequence to inhibit T cell
proliferation
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in vitro. Some such dimers are capable of inhibiting or suppressing an immune
response
in a subject in vivo, such as through the administration of a therapeutically
or
prophylactically effective amount of at least one such dimer to a subject
needing
immunosuppressive therapy. Some such fusion protein dimers are expected to be
useful in
a variety of applications, including, e.g., but not limited to, in
prophylactic and/or
therapeutic methods for inhibiting or suppressing an immune response in a
subject
suffering from an immune system disease or disorder in which immunosuppression
is
desirable (e.g., autoimmune diseases) and methods for inhibiting rejection of
a tissue, cell,
or organ transplant from a donor by a recipient.
Some such dimers have varied abilities to modulate or suppress signaling
through
CD28, since they have different comparative binding avidities for CD80 and
CD86. Such
dimers are useful in applications in which differential manipulation of T cell
responses is
desirable, including therapeutic and prophylactic methods for treating immune
system
diseases and disorders, such as, e.g., immunodeficiency diseases and disorders
(e.g., RA,
MS, psoriasis, etc.). Exemplary dimeric fusion proteins comprising
polypeptides of the
invention having some of the above-described differential CD80/CD86 binding
avidities
and immunoinhibitory properties are shown hi Example 4.
Some such mutant CTLA-4-Ig dimers have an ability to suppress or inhibit an
immune response that is at least about equal to or greater than the ability of
the hCTLA-4
protein or a hCTLA-4-Ig dimer to suppress or inhibit one or more types of
immune
responses. For example, some such dimers have an ability to inhibit T cell
activation or
proliferation in in vitro and/or in vivo assays and/or applications, such as
those described
above and below, which is at least about equal to or greater than the ability
of the hCTLA-
4 protein or a hCTLA-4-Ie dimer (e.g., Orencia , hCTLA-4-Ig02 dimer, or hCTLA-
4-
IgG1 dimer) to inhibit T cell activation or proliferation in such
applications. Additionally,
some such dimers have an ability to inhibit or suppress an immune response
(e.g., T cell
activation or proliferation, cytokine production, T cell-dependent antibody
response) that
is greater than the ability of a LEA29Y-Ig dimer to inhibit or suppress an
immune
response. Examples 4-9, e.g., compare the ability of representative dimeric
fusion proteins
of the invention comprising a mutant CTLA-4 ECD polypeptide sequence of the
invention
to inhibit T cell proliferation in vitro relative to the ability of dimeric
hCTLA-4-IgG2,
Orencia , and LEAY29-Ig to inhibit T cell proliferation in vitro. See, e.g.,
Tables 6-9
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=
below. Some such dimers have both an ability to bind hCD80 and/or hCD86 (or
hCD80-
Ig and/or hCD86-Ig) and an ability to inhibit or suppress an immune response
in an in
vitro and/or in vivo assays and/or applications, such as those described above
and in
greater detail below (e.g., an in vivo method in which in a therapeutically or
prophylactically effective amount of at least one such dimer is administered).
Some such
dimers have a binding avidity for hCD80 and/or hCD86 (or hCD80-Ig and/or hCD86-
Ig)
that is at least about equal to or greater than the binding avidity of hCTLA-4
protein, a
dimeric hCTLA-4-Ig (e.g., hCTLA-4-IgG2, OrenciaC)) or dimeric LEA29Y-Ig for
hCD80
and/or hCD86 (or hCD80-Ig and/or hCD86-Ig), respectively, and an ability to
inhibit an
immune response that is at least equal to or greater than the ability of hCTLA-
4 protein, a
dimeric hCTLA-4-Ig (e.g., hCTLA-4-IgG2, OrenciaC)) or dimeric LEA29Y-Ig to
inhibit
an immune response. Such mutant CTLA-4-Ig fusion protein dimers are expected
to be
useful in a variety of applications, including, e.g., prophylactic and/or
therapeutic methods
for treating immune system diseases, disorders, and conditions, as discussed
in greater
detail infra.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer (e.g., mutant CTLA-4-Ig fusion protein dimer) comprising two identical
monomeric
fusion proteins (e.g., two monomeric mutant CTLA-4-Ig fusion proteins),
wherein each
such monomeric fusion protein comprises a polypeptide sequence having at least
90%,
90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%,
97%, 97.5%, 98%, 98.5%, 99%, 99.5%, or 100% identity to a polypeptide sequence
selected from the group consisting of SEQ ID NOS:74-79, 197-200, 205-214, and
219-
222, wherein the dimer binds CD80 and/or CD86 (and/or a CD80-Ig and/or CD86-
Ig, such
as hCD80-mIg and/or hCD86-mIg, respectively), and/or has an ability to inhibit
an
immune response, including those described above and further below. Each of
the
polypeptide sequences set forth in SEQ ID NOS:74-79, 197-200, 205-214, and 219-
222 is
a mature mutant CTLA-4 ECD fused at its C-terminus to the N-terminus of an
IgG2 Pc
polypeptide, and each such sequence may be termed a mutant CTLA-4-Ig fusion
protein.
The polypeptide sequence of each of SEQ ID NOS:74-79, 197-200, 220, and 222 is
identical to SEQ ID NOS:205-214, 219, and 221, except that each of SEQ ID
NOS:74-79,
197-200, 220, and 222 includes a lysine at the C-terminus.
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In another aspect, the invention provides an isolated or recombinant fusion
protein
monomer comprising a polypeptide sequence having at least 90%, 90.5%, 91%,
91.5%,
92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%,
98.5%, 99%, 99.5%, or 100% identity to a polypeptide sequence comprising amino
acid
residues 1-351 of any of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222,
wherein the
fusion protein binds CD80 and/or CD86 (and/or a CD80-Ig and/or CD86-Ig, such
as
hCD80-mIg and/or hCD86-mIg, respectively), and/or has an ability to inhibit an
immune
response, including those described above and further below.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer comprising two identical monomeric fusion proteins, wherein each such
monomeric
fusion protein comprises a polypeptide sequence having at least 90%, 91%, 92%,
93%,
94%, 95%, 96%, 97%, 98%, 99% or 100% identity to a polypeptide sequence
comprising
amino acid residues 1-351 of any of SEQ ID NOS:74-79, 197-200, 205-214, and
219-222,
wherein said fusion protein dimer protein binds CD80 and/or CD86 (and/or a
CD80-Ig
and/or CD86-Ig, such as hCD80-mIg and/or hCD86-mIg, respectively), and/or has
an
ability to inhibit an immune response, including those described above and
further below.
Also provided is a mutant monomeric CTLA-4-Ie fusion protein comprising a
polypeptide sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,
98%,
99% or 100% identity to a polypeptide sequence selected from the group
consisting of
SEQ ID NOS:74-79, 197-200, 205-214, and 219-222, wherein said monomeric fusion
protein binds CD80 and/or CD86 (and/or a CD80-Ig and/or CD86-Ig, such as hCD80-
mIg
and/or hCD86-mIg, respectively), and/or has an ability to inhibit an immune
response.
Some such fusion protein monomers and dimers have an ability to inhibit or
suppress one
or more immune responses, including, e.g., T cell activation or proliferation,
cytokine
synthesis or production (e.g., production of TNF-a... IFNI', IL-2), induction
of activation
markers (e.g., CD25, IL-2 receptor), inflammation, anti-collagen Ab
production, and/or T
cell-dependent Ab response(s)) in in vitro and/or in vivo assays and/or
methods (e.g., in
vivo in a subject suffering from a disease, disorder, or condition in which
immunosuppressive therapy would be of benefit and to whom a therapeutically
effective
amount of such dimeric fusion protein is administered as discussed in greater
detail
below). Such fusion protein monomers and dimers are expected to be useful in a
variety
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of applications, including therapeutic and/or prophylactic methods for
treating immune
system diseases, including those discussed below.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer (e.g., mutant CTLA-4-Ig fusion protein dimer) comprising two monomeric
fusion
proteins (e.g., monomeric mutant CTLA-4-Ig fusion protein), wherein each such
monomeric fusion protein comprises: (1) a polypeptide (e.g., mutant CTLA-4
extracellular
domain polypeptide) which comprises a polypeptide sequence which differs from
a
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73 in
no more
than 6 amino acid residues (e.g., no more than 1, 2, 3, 4, 5, or 6 amino acid
residues), and
wherein the amino acid residue in the polypeptide sequence at position 41, 50,
54, 55, 56,
64, 65, 70, or 85 is identical to the amino acid residue at the corresponding
position of said
selected polypeptide sequence (e.g., a polypeptide selected from SEQ ID NOS:1-
73), and
(2) an Ig Fe polypeptide (e.g., IgG2 Fe), wherein the fusion protein dimer
binds CD80
and/or CD86 (and/or CD80-Ig and/or CD86-Ig), and/or inhibits an immune
response (e.g.,
T cell activation or proliferation, cytokine production, induction of
activation markers or
inflammatory molecules, anti-collagen Ab production, T cell-dependent Ab
responses,
etc.) in in vitro and/or in vivo assays and/or methods as discussed in detail
below. The
invention also includes an isolated or recombinant monomeric fusion protein as
described
above which binds CD80 and/or CD86 (and/or CD80-Ig and/or CD86-Ig) and/or
induces
an immune response in vitro or in vivo. In the fusion protein dimer, the two
monomeric
fusion proteins (e.g., mutant CTLA-4-Ig monomer) are optionally covalently
linked
together by one or more disulfide bonds via cysteine residues in each monomer,
and the
two monomers are typically identical to one another. In some instances, the
mutant
CTLA-4 ECD polypeptide in such fusion protein dimer or monomer differs from
the
selected polypeptide (e.g., selected from SEQ ID NOS:1-73) in no more than 6
amino acid
residues, but the amino acid occupying position 41, 50, 54, 55, 56, 64, 65,
70, or 85 is
identical to the amino acid residue included at that position in the selected
polypeptide
sequence; that is, an amino acid residue at such position cannot be deleted or
substituted.
Some such mutant CTLA-4 ECD polypeptides in such a fusion protein comprise a
polypeptide sequence which differs from the selected polypeptide sequence by
no more
than 6 amino acid residues and which includes amino acid residues at positions
24, 30, 32,
41, 50, 54, 55, 56, 64, 65, 70, 85, 104 and 106 that are identical to the
amino acid residues
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at the corresponding positions in the selected polypeptide sequence. Such
mutant CTLA-4
ECD polypeptide can differ from the selected polypeptide sequence by amino
acid
deletion(s), addition(s), and/or amino acid substitution(s). An amino acid
substitution may
be a conservative or non-conservative substitution. See, the "Sequence
Variation"
section. Some such dimeric fusion proteins have a binding avidity for hCD86 or
hCD86-
Ig that is at least about equal to or greater than the binding avidity of
hCTLA-4, dimeric
hCTLA-4-Ig, dimeric LEA29Y-Ig, or Orencia protein for hCD86 or hCD86-Ig,
respectively. Some such monomeric fusion proteins have a binding affinity or
avidity for
hCD86, hCD86-Ig, or hCD86 ECD that is at least about equal to or greater than
the
binding affinity or avidity of the monomeric hCTLA-4, monomeric hCTLA-4-Ig, or
monomeric LEA29Y-Ig for hCD86, hCD86-Ig, or hCD86 ECD, respectively.
Alternatively or additionally, some such dimeric fusion proteins have a
binding avidity for
hCD80 or hCD80-Ig that is at least about equal to or greater than the avidity
of hCTLA-4
or hCTLA-4-Ig for hCD80, respectively. Alternatively or additionally, some
such
monomeric fusion proteins have a binding affinity or avidity for hCD80, hCD80-
Ig, or
hCD80 ECD that is at least about equal to or greater than the binding affinity
or avidity of
monomeric hCTLA-4 or monomeric hCTLA-4-Ig for hCD80, hCD80-Ig, or hCD80 ECD,
respectively. In some instances, the mutant CTLA-4 ECD polypeptide in such
fusion
protein dimer or monomer comprises a polypeptide sequence having a length
about equal
to the amino acid length of the hCTLA-4 ECD, e.g., from about 118-130, 119-
129, 120-
128, 121- 127, 122-126, 123-125, or 124 amino acid residues in length. The N-
terminus of
the Ig Fc polypeptide (e.g., IgG2 Fc, IgG1 Fc, IgG4 Fc, or a mutant IgG Fc
that reduces
effector function or Fc receptor binding) may be covalently linked or fused
directly or
indirectly (via a linker comprising, e.g., from 1-10 amino acid residues) to
the C-terminus
of the mutant CTLA-4 ECD polypeptide. The Ig Fc polypeptide may comprise a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% sequence
identity to a polypeptide sequence selected from the group consisting of SEQ
ID
NOS:184-186 and 218, e.g., any of SEQ ID NO:184, 185, 186, and 218.
Some such mutant CTLA-4-Ig fusion protein dimers and monomers are capable of
suppressing one or more of a variety of immune responses, including, e.g., T
cell
activation, T cell proliferation, cytokine synthesis or production (e.g.,
production of TNF-
a, IFN-y, IL-2), induction of activation markers (e.g., CD25, IL-2 receptor)
or
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inflammatory molecules, inflammation. anti-collagen Ab production, and/or T
cell-
dependent Ab response(s). Some such mutant CTLA-4-Ig dimers have a greater
ability to
inhibit one or more such immune responses than hCTLA-4, dimeric hCTLA-4-Ig, or
dimeric LEA29Y-Ig. Examples 4-9, e.g., provide data comparing the ability of
representative dimeric fusion proteins of the invention comprising a mutant
CTLA-4 ECD
polypeptide of the invention to inhibit T cell proliferation in vitro relative
to the ability of
a dimeric hCTLA-4-Ig or dimeric LEA29Y-Ig to do so. Some such mutant CTLA-4-Ig
monomers have a greater ability to inhibit one or more such immune responses
than
monomeric hCTLA-4, monomeric hCTLA-4-Ig, or monomeric LEA29Y-Ig. Some such
monomers and dimers are capable of inhibiting or suppressing an immune
response in a
subject in vivo, such as through the administration of a therapeutically or
prophylactically
effective amount of at least one such polypeptide to a subject needing
immunosuppressive
therapy. Such fusion proteins are expected to be of beneficial use in a
variety of
applications, including methods for treating a disease, disorder, or condition
in which
immunosuppressive therapy would be of benefit, such as prophylactic and/or
therapeutic
methods for treating autoimmune diseases and disorders, and methods for
inhibiting organ,
cell, or tissue graft transplantation.
In another aspect, the invention provides an isolated or recombinant protein
dimer
(e.g., mutant CTLA-4-Ig fusion protein dimer) comprising two monomeric fusion
proteins
(e.g., two monomeric mutant CTLA-4-Ig fusion proteins), wherein each such
monomeric
fusion protein comprises: (1) a mutant CTLA-4 extracellular domain (ECD)
polypeptide
comprising a polypeptide sequence which (a) differs from a polypeptide
sequence selected
from the group consisting of SEQ ID NOS:1-73 in no more than 6 amino acid
residues
(e.g., no more than 1, 2, 3, 4, 5, or 6 amino acid residues), and (b)
comprises at least one
amino acid substitution at an amino acid position corresponding to position
50, 54, 55, 56,
64, 65, 70, or 85 relative to the polypeptide sequence of SEQ ID NO:159; and
(2) an Ig Fc
polypeptide, wherein the fusion protein dimer binds CD80 and/or CD86 (and/or
CD80-Ig
and/or CD86-Ig), and/or inhibits an immune response (e.g., T cell activation
or
proliferation, cytokine production, induction of activation markers,
inflammation, anti-
collagen antibody production, T cell-dependent antibody response, etc.) in in
vitro and/or
in vivo assays and/or methods as described in greater detail below. The
invention also
includes an isolated or recombinant monomeric fusion protein, as described
above, which
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binds CD80 and/or CD86 (and/or CD80-Ig and/or CD86-Ig) and/or induces an
immune
response in vitro or in vivo. In some instances. CD80 is hCD80 and CD86 is
hCD86. In
the fusion protein dimer, the two monomeric fusion proteins (e.g., mutant CTLA-
4-Ig
monomer) are optionally covalently linked together by one or more disulfide
bonds via
cysteine residues in each monomer, and the two monomers are typically
identical to one
another. The N-terminus of the Ig Fc polypeptide (e.g., IgG2 Fc, IgG1 Fc, IgG4
Fc, or a
mutant IgG Fc that reduces effector function or Fc receptor binding) may be
covalently
linked or fused directly or indirectly (via a linker comprising, e.g., from 1-
10 amino acid
residues) to the C-terminus of the mutant CTLA-4 ECD polypeptide. The Ig Fc
polypeptide may comprise a polypeptide sequence having at least 95%, 96%, 97%,
98%,
99%, or 100% sequence identity to a polypeptide sequence selected from the
group
consisting of SEQ ID NOS:184-186 and 218.
Some such fusion protein dimers or monomers comprise a mutant CTLA-4 ECD
polypeptide which comprises a polypeptide sequence having a length about equal
to the
amino acid length of the hCTLA-4 ECD, e.g., 118-130, 119-129, 120-128, 121-
127, 122-
126, or 123-125 amino acid residues in length. Some such mutant CTLA-4 ECD
polypeptides in such fusion protein dimer or monomer comprise a polypeptide
sequence
that is 124 amino acid residues in length. Some such mutant CTLA-4-ECD
polypeptides
comprise 2, 3, 4, 5, or 6 amino acid substitutions at positions relative to
the sequence set
forth in SEQ ID NO:159 selected from the group consisting of position 50, 54,
55, 56, 64,
65, 70, and 85. Some such mutant CTLA-4 ECD polypeptides further comprise an
amino
acid substitution at a position corresponding to position 104 and/or 30
relative to SEQ ID
NO:159. Some such mutant CTLA-4 ECD polypeptides comprise at least one amino
acid
substitution relative to SEQ ID NO:159 at position 70 (optionally S70F),
position 64
(optionally S64P), position 50 (optionally A50M), position 54 (optionally
M54K/V, e.g.,
M54K), position 65 (optionally I65S), position 56 (optionally N56D), position
55
(optionally G55E), position 85 (optionally M85A), and/or position 24
(optionally A24E/S,
e.g., A24E). Any such mutant CTLA-4 ECD polypeptide may further comprise an
amino
acid substitution relative to SEQ ID NO:159 at position 104 (optionally
LIO4E/D, e.g.,
L104E), position 30 (optionally T3ON/D/A, e.g., T3ON, T30D, or T30A), and/or
position
32 (optionally V321). Some such mutant CTLA-4 ECD polypeptides comprise at
least one
substitution at an amino acid position relative to SEQ ID NO:159 selected from
the group
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consisting of A50M, M54K, G55E, N56D, S64P, I65S, and S70F. Some such mutant
CTLA-4 ECD polypeptides comprise 2, 3, 4, 5, or 6 substitutions at amino acid
positions
relative to SEQ ID NO:159 selected from the group consisting of A50M, M54K,
G55E,
N56D, S64P, I65S, and S70F.
Some such mutant CTLA-4-Ig dimers exhibit a binding avidity for CD86 (e.g.,
hCD86) or dimeric CD86-Ig (e.g., hCD86-Ig) that is about equal to or greater
than the
binding avidity of hCTLA-4 protein, dimeric hCTLA-4-Ig (e.g., CTLA-4-IgG1 or
CTLA-
4-IgG2), OrenciaO protein, or dimeric LEA29Y-Ig for CD86 or dimeric CD86-Ig,
respectively. Some such dimers have a binding avidity for CD80 (e.g., hCD80)
or dimeric
CD80-Ig (e.g., hCD80-Ig) that is greater than the binding avidity of hCTLA-4,
a dimeric
hCTLA-4-Ig, Orencia protein, and/or dimeric LEAY29-Ig for CD80 or dimeric
CD80-
Ig, respectively.
Some such mutant CTLA-4-Ig monomers exhibit a binding affinity or avidity for
CD86 (e.g., hCD86) or CD86-Ig (e.g., hCD86-Ig) that is about equal to or
greater than the
binding affinity or avidity of monomeric hCTLA-4, monomeric hCTLA-4-Ig, or
monomeric LEA29Y-Ig for CD86 or CD86-Ig, respectively. Some such monomers have
a
binding affinity or avidity for CD80 (e.g., hCD80) or CD80-Ig (e.g., hCD80-Ig)
that is
greater than the binding affinity or avidity of monomeric hCTLA-4 or monomeric
hCTLA-4-Ig (e.g., monomeric CTLA-4-IgG1 or CTLA-4-IgG2) for CD80 or dimeric
CD80-Ig, respectively.
Some such mutant CTLA-4-Ig dimers and monomers have an ability to suppress or
inhibit one or more immune responses, including those described above and
throughout
(e.g., T cell activation or proliferation, cytokine production, induction of
activation
markers, inflammation, anti-collagen antibody production, T cell-dependent
antibody
responses), in in vitro and/or in vivo assays and/or methods (e.g., in vivo in
a subject
suffering from a disease, disorder, or condition in which immunosuppressive
therapy
would be of benefit and to whom a therapeutically effective amount of at least
one such
mutant CTLA-4-Ig dimer is administered). Some such mutant CTLA-4-Ig dimers
inhibit
one or more such immune responses to a greater degree than hCTLA-4, a dimeric
hCTLA-
4-Ig (e.g., dimeric CTLA-4-IgG1 or CTLA-4-IgG2), OrenciaO protein, and/or
dimeric
LEAY29-Ig. Some such mutant CTLA-4-Ig monomers inhibit one or more such immune
responses to a greater degree than monomeric hCTLA-4, monomeric hCTLA-4-Ig,
and/or
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monomeric LEAY29-1g. Such mutant CTLA-4-Ig dimers and monomers are expected to
be of beneficial use in a variety of applications, including methods for
treating
autoimmune diseases and disorders, and methods for inhibiting organ, cell, or
tissue graft
transplantation.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer (e.g., mutant CTLA-4-Ig fusion protein dimer) comprising two monomeric
fusion
proteins (e.g., monomeric mutant CTLA-4-Ig fusion protein), wherein each such
monomeric fusion protein comprises: (1) a polypeptide (e.g., mutant CTLA-4
extracellular
domain) comprising a polypeptide sequence which (i) has at least 95%, 96%,
97%, 98%,
99%, or 100% sequence identity to any polypeptide sequence selected from the
group
consisting of SEQ ID NOS:1-73 and (ii) includes a phenylalanine residue at an
amino acid
position corresponding to position 70 of said polypeptide sequence selected
from the
group consisting of SEQ ID NO:1-73; and (2) an Ig Fc polypeptide (e.g., IgG2
Fc, IgG1
Fc, IgG4 Fc, or a mutant IgG Fc that reduces effector function or Fc receptor
binding),
wherein the fusion protein dimer binds CD80 (e.g., hCD80) and/or CD86 (e.g.,
hCD86)
(and/or CD80-Ig, e.g., hDC80-Ig, and/or CD86-Ig, e.g., hCD86-Ig), and/or has
an ability
to inhibit an immune response in vitro or in vivo. The invention also includes
an isolated
or recombinant monomeric fusion protein as described above which binds CD80
hCD80) and/or CD86 (e.g., hCD86) (and/or CD80-Ig, e.g., hDC80-Ig, and/or CD86-
Ig,
e.g., hCD86-Ig) and/or induces an immune response in vitro or in vivo. In some
instances,
the Ig Fc polypeptide comprises a sequence having at least 95%, 96%, 97%, 98%,
99%, or
100% sequence identity to a polypeptide sequence selected from the group
consisting of
SEQ ID NOS:184-186 and 218. The N-terminus of the Ig Fc polypeptide may be
covalently linked or fused directly or indirectly (via a linker comprising,
e.g., from 1-10
amino acids) to the C-terminus of the mutant CTLA-4 ECD polypeptide.
In some such mutant CTL-4-Ig dimers or monomers, the mutant CTLA-4 ECD
polypeptide comprises one or more of the following relative to said selected
polypeptide
sequence: a glutamic acid residue at an amino acid position corresponding to
position 24;
an aspara,gine residue at an amino acid position corresponding to position 30;
an isoleucine
residue at an amino acid position corresponding to position 32; a methionine
residue at an
amino acid position corresponding to position 50; a lysine residue at an amino
acid
position corresponding to position 54; a glutamic acid residue at an amino
acid position
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corresponding to position 55; an aspartic acid residue at an amino acid
position
corresponding to position 56; a proline residue at an amino acid position
corresponding to
position 64; a serine residue at an amino acid position corresponding to
position 65; and a
glutamic acid residue at an amino acid position corresponding to position 104.
For
example, some such mutant CTLA-4 ECD polypeptides in such mutant CTLA-4-Ig
dimers
or monomers comprise a polypeptide sequence comprising (i) at least 95%, 96%,
97%,
98%, 99%, or 100% sequence identity to the polypeptide sequence of SEQ ID
NO:24 and
(ii) a phenylalanine residue at an amino acid position corresponding to
position 70 of the
polypeptide sequence of SEQ ID NO:24, wherein the fusion protein dimer binds
hCD80
and/or hCD86 (and/or hCD80-Ig and/or hCD86-Ig), and/or inhibits an immune
response in
in vitro and/or in vivo assays and/or methods. Some such mutant CTLA-4 ECD
polypeptides in such mutant CTLA-4-Ig dimers or monomers comprises one or more
of
the following relative to SEQ ID NO:24: a glutamic acid residue at position
24; an
asparagine residue at position 30; an isoleucine residue at position 32; a
methionine
residue at position 50; a lysine residue at position 54; a glutamic acid
residue at position
55; an aspartic acid residue at position 56; a proline residue at position 64;
a serine residue
at position 65; and a glutamic acid residue at position 104.
Some such mutant CTLA-4-Ig dimers exhibit a binding avidity for CD86 (e.g.,
hCD86) or dimeric CD86-Ig (e.g., hCD86-Ig) that is about equal to or greater
than the
binding avidity of hCTLA-4, dimeric hCTLA-4-Ig, Orencia protein, or dimeric
LEA29Y-Ig for CD86 or dimeric CD86-Ig, respectively. Some such dimers have a
binding avidity for CD80 (e.g., hCD80) or dimeric CD80-Ig (e.g., hCD80-Ig)
that is
greater than the binding avidity of hCTLA-4, a dimeric hCTLA-4-Ig, or Orencia
protein
for CD80 or dimeric CD80-Ig, respectively.
Some such mutant CTLA-4-Ig monomers exhibit a binding affinity or avidity for
CD86 (e.g., hCD86) or CD86-Ig (e.g., hCD86-Ig) that is about equal to or
greater than the
binding affinity or avidity of monomeric hCTLA-4, monomeric hCTLA-4-Ig, and/or
monomeric LEA29Y-Ig for CD86 or CD86-Ig, respectively. Some such monomers have
a
binding affinity or avidity for CD80 (e.g., hCD80) or CD80-Ig (e.g., hCD80-Ig)
that is
greater than the binding affinity or avidity of monomeric hCTLA-4 or monomeric
hCTLA-4-Ig for CD80 or dimeric CD80-Ig, respectively.
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Some such mutant CTLA-4-Ig dimers and monomers have an ability to suppress or
inhibit one or more immune responses (e.g., T cell activation or
proliferation, cytokine
production, induction of activation markers, inflammation, anti-collagen Ab
production, T
cell-dependent Ab responses), in in vitro and/or in vivo assays and/or methods
(e.g., in
vivo in a subject suffering from an immune system disease, disorder, or
condition in which
immunosuppressive therapy would be of benefit and to whom a therapeutically
effective
amount of at least one such mutant CTLA-4-Ig dimer is administered). Some such
mutant
CTLA-4-Ig dimers have an ability to suppress or inhibit one or more such
immune
responses to a greater degree than hCTLA-4, a dimeric hCTLA-4-Ig (e.g.,
dimeric CTLA-
4-IgG1 or CTLA-4-IgG2), Orencia protein, and/or dimeric LEAY29-Ig. Some such
mutant CTLA-4-Ig monomers have an ability to suppress or inhibit one or more
such
immune responses to a greater degree than monomeric hCTLA-4, monomeric hCTLA-4-
Ig, and/or monomeric LEAY29-Ig. Such mutant CTLA-4-Ig dimers and monomers are
expected to be of beneficial use in a variety of therapeutic and/or
prophylactic methods for
treating diseases or disorders in which immunosuppressive treatment would be
of benefit,
including, e.g., methods for treating autoimmune diseases and methods for
inhibiting
rejection of organ, cell, or tissue graft transplant.
In yet another aspect, the invention provides an isolated or recombinant
fusion
protein dimer (e.g., mutant CTLA-4-Ig fusion protein dimer) comprising two
monomeric
fusion proteins (e.g., monomeric mutant CTLA-4-Ig fusion proteins), wherein
each such
monomeric fusion protein comprises: (1) a polypeptide (e.g., mutant CTLA-4
extracellular
domain) comprising a polypeptide sequence which (a) differs from the
polypeptide
sequence of the human CTLA-4 extracellular domain polypeptide shown in SEQ ID
NO:159 in no more than 6 amino acid residues, and (b) comprises at least one
amino acid
substitution, wherein said at least amino acid substitution comprises S70F,
wherein amino
acid residue positions are numbered according to SEQ ID NO:159; and (2) an IgG
Fc
polypeptide (e.g., IgG2 Fe, IgG1 Fc, IgG4 Fe, or a mutant IgG Fe that reduces
effector
function or Fe receptor binding), wherein said dimer binds hCD80 and/or hCD86
(and/or
hCD86-Ig and/or hCD86-Ig), and/or inhibits an immune response (e.g., T cell
activation or
proliferation, cytokine production, induction of activation markers,
inflammation, anti-
collagen antibody production, T cell-dependent antibody response, etc.) in in
vitro and/or
in vivo assays and/or methods as discussed in detail below. The invention also
includes an
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isolated or recombinant monomeric fusion protein as described above which
binds CD80
(e.g., hCD80) and/or CD86 (e.g., hCD86) (and/or CD80-Ig, e.g., hDC80-Ig,
and/or CD86-
Ig, e.g., hCD86-Ig) and/or induces an immune response in vitro or in vivo. The
Ig Fc
polypeptide may comprise a sequence having at least 95%, 96%, 97%, 98%, 99%,
or
100% identity to a polypeptide sequence selected from the group consisting of
SEQ ID
NOS:184-186 and 218. The N-terminus of the Ig Fc polypeptide may be covalently
linked
or fused directly or indirectly (via a linker comprising, e.g., from 1-10
amino acids) to the
C-terminus of the mutant CTLA-4 ECD polypeptide. In some such mutant CTLA-4-Ig
dimers or monomers, the mutant CTLA-4 ECD polypeptide further comprises at
least one
amino acid substitution selected from the group consisting of A24E, T3ON,
V32I, D41G,
A50M, M54K, G55E, N56D, S64P, 165S, M85A, L104E, and 1106F. In some such
mutant CTLA-4-Ig dimers or monomers, the mutant CTLA-4 ECD polypeptide further
comprises the substitution L104E and/or two, three, or four additional
substitutions
selected from the group of substitutions: T3ON, V32I, A50M, M54K, G55E, N56D,
S64P,
and I65S.
Some such dimers have a binding avidity for CD86 (e.g., hCD86) or dimeric
CD86-1g (e.g., hCD86-Ig) that is about equal to or greater than the binding
avidity of
hCTLA-4, dimeric hCTLA-4-Ig, and/or Orencia0 protein for CD86 or dimeric CD86-
Ig,
respectively. Some such dimers have a binding avidity for CD80 (e.g., hCD80)
or dimeric
CD80-Ig (e.g., hCD80-Ig) that is greater than the binding avidity of hCTLA-4,
a dimeric
hCTLA-4-1g, and/or Orencia0 for CD80 or dimeric CD80-Ig, respectively. Some
such
monomers exhibit a binding affinity or avidity for CD86 (e.g., hCD86) or CD86-
Ig (e.g.,
hCD86-Ig) that is about equal to or greater than the binding affinity or
avidity of
monomeric hCTLA-4, monomeric hCTLA-4-Ig, or monomeric LEA29Y-Ig for CD86 or
CD86-Ig, respectively. Some such monomers have a binding affinity or avidity
for CD80
(e.g., hCD80) or CD80-Ig (e.g., hCD80-Ig) that is greater than the binding
affinity or
avidity of monomeric hCTLA-4 or monomeric hCTLA-4-Ig for CD80 or dimeric CD80-
Ig, respectively.
Some such mutant CTLA-4-1g dimers and monomers have an ability to suppress or
inhibit one or more immune responses (e.g., T cell activation or
proliferation, cytokine
production, induction of activation markers, inflammation, anti-collagen
antibody
production, T cell-dependent antibody responses), in in vitro and/or in vivo
assays and/or
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methods (e.g., in vivo in a subject suffering from a disease, disorder, or
condition in which
immunosuppressive therapy would be of benefit and to whom a therapeutically
effective
amount of at least one such mutant CTLA-4-Ig, dimer is administered). Some
such dimers
have an ability to suppress or inhibit one or more such immune responses to a
greater
degree than hCTLA-4, a dimeric hCTLA-4-Ig (e.g., dimeric CTLA-4-IgG1 or CTLA-4-
IgG2), Orencia protein, and/or dimeric LEAY29-Ig. Some such monomers have an
ability to suppress or inhibit one or more such immune responses to a greater
degree than
monomeric hCTLA-4, monomeric hCTLA-4-Ig, and/or monomeric LEAY29-Ig. Such
mutant CTLA-4-Ig dimers and monomers are expected to be of beneficial use in a
variety
of therapeutic and/or prophylactic methods for treating diseases or disorders
in which
immunosuppressive treatment would be of benefit, including, e.g., methods for
treating
autoimmune diseases and disorders and methods for inhibiting organ or tissue
graft
transplantation.
In another aspect, the invention provides an isolated or recombinant fusion
protein
dimer (e.g., mutant CTLA-4-Ig fusion protein dimer) comprising two monomeric
fusion
proteins (e.g., mutant CTLA-4-Ig fusion protein), wherein each such monomeric
fusion
protein comprises: (1) a polypeptide (e.g., mutant CTLA-4 extracellular
domain)
comprising a polypeptide sequence which (a) differs from the polypeptide
sequence of
SEQ ID NO:31 in no more than 6 amino acid residues, and (b) comprises at least
one of
the following: a methionine residue at a position corresponding to position 50
of SEQ ID
NO:31, a lysine residue at a position corresponding to position 54 of SEQ ID
NO:31, a
glutamic acid residue at a position corresponding to position 55 of SEQ ID
NO:31, a
proline residue at a position corresponding to position 64 of SEQ ID NO:31, a
serine
residue at a position corresponding to position 65 of SEQ ID NO:31, a
phenylalanine
residue at a position corresponding to position 70 of SEQ ID NO:31, wherein
amino acid
residue positions are numbered according to SEQ ID NO:31; and (2) an Ig Fc
polypeptide,
wherein said dimer binds hCD80 and/or hCD86 (and/or hCD86-Ig and/or hCD86-Ig),
and/or inhibits an immune response. The invention also includes an isolated or
recombinant monomeric fusion protein as described above which binds CD80
(e.g.,
hCD80) and/or CD86 (e.g., hCD86) (and/or CD80-Ig, e.g., hDC80-Ig, and/or CD86-
Ig,
e.g., hCD86-Ig) and/or induces an immune response in vitro or in vivo. The Ig
Fc
polypeptide may comprise a IgG2 Fc, IgG1 Fc, IgG4 Fc, or a mutant IgG Fc that
reduces
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effector function or Fc receptor binding. The IR Fc polypeptide may comprise a
sequence
having at least 95%, 96%, 97%, 98%, 99%, or 100% identity to a polypeptide
sequence
selected from the group consisting of SEQ ID NOS:184-186 and 218. The N-
terminus of
the Ig Fc polypeptide may be covalently linked or fused directly or indirectly
(via a linker
comprising, e.g., from 1-10 amino acids) to the C-terminus of the mutant CTLA-
4 ECD
polypeptide. In some such dimers or monomers, the mutant CTLA-4 ECD
polypeptide
comprises a glutamic acid residue at a position corresponding to position 104,
an
asparagine acid residue at a position corresponding to position 30, and/or an
isoleucine
residue at a position corresponding to position 32 of SEQ ID NO:31.
Some such dimers have a binding avidity for CD86 (e.g., hCD86) or dimeric
CD86-Ig (e.2., hCD86-Ig) that is about equal to or greater than the binding
avidity of
hCTLA-4 protein, dimeric hCTLA-4-Ig, Orencia0 protein, and/or dimeric LEAY29-
Ig for
CD86 or dimeric CD86-Ig, respectively. Some such dimers have a binding avidity
for
CD80 (e.g., hCD80) or dimeric CD80-Ig (e.g., hCD80-Ig) that is greater than
the binding
avidity of hCTLA-4, dimeric hCTLA-4-Ig, and/or Orencia protein for CD80 or
dimeric
CD80-Ig, respectively. Some such monomers exhibit a binding affinity or
avidity for
CD86 (e.g., hCD86) or CD86-Ig (e.g., hCD86-Ig) that is about equal to or
greater than the
binding affinity or avidity of monomeric hCTLA-4, monomeric hCTLA-4-Ig, or
monomeric LEA29Y-Ig for CD86 or CD86-Ig, respectively. Some such monomers have
a
binding affinity or avidity for CD80 (e.g., hCD80) or CD80-Ig (e.g., hCD80-Ig)
that is
greater than the binding affinity or avidity of monomeric hCTLA-4 or monomeric
hCTLA-4-Ig for CD80 or dimeric CD80-Ig, respectively.
Some such mutant CTLA-4-Ig dimers and monomers have an ability to suppress or
inhibit one or more immune responses (e.g., T cell activation or
proliferation, cytoldne
production, induction of activation markers, inflammation, anti-collagen
antibody
production, T cell-dependent antibody responses) in vitro and/or in vivo as
discussed in
detail below. Some such dimers have an ability to suppress one or more such
immune
responses to a greater degree than hCTLA-4, a dimeric hCTLA-4-Ig, Orencia
protein,
and/or dimeric LEAY29-Ig. Some such monomers have an ability to suppress or
inhibit
one or more such immune responses to a greater degree than monomeric hCTLA-4
or a
monomeric hCTLA-4-Ig. Such mutant CTLA-4-Ig dimers and monomers are expected
to
be of beneficial use in a variety of therapeutic and/or prophylactic methods
for treating
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immune system diseases or disorders in which immunosuppressive treatment would
be of
benefit (e.g., autoimmune diseases and disorders and methods for inhibiting
organ or
tissue graft transplantation).
Any such dimeric or monomeric mutant CTLA-4-Ig fusion protein dimer or
monomer described above may further include a peptide that facilitates
secretion of the
fusion protein from a host cell. The peptide is optionally a signal peptide.
The C-terminus
of the signal peptide is typically covalently linked to the N-terminus of a
fusion protein.
The signal peptide may comprise an amino acid sequence having at least 90%,
91%, 92%,
93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence
of
SEQ ID NO:182 or SEQ ID NO:216. The signal peptide may comprise an amino acid
sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or
100% identity to an amino acid sequence comprising amino acid residues 1-35, 1-
36, or 1-
37 of SEQ ID NO:160. Furthermore, as discussed below, any such monomeric or
dimeric
mutant CTLA-4-Ig fusion protein described above may comprise one or more of
the
amino acid residues that are glycosylated or pegylated.
The invention also provides a mature/secreted mutant CTLA-4-IgG2 fusion
protein
that is 352 amino acids in length and comprises a mutant CTLA-4 ECD
polypeptide
comprising 124 amino acid residues and a human IgG2 Fc polypeptide comprising
228
amino acid residues. Exemplary mutant CTLA-4 ECD polypeptides include those
polypeptides comprising sequences identified by any of SEQ ID NOS:1-73.
Exemplary
mutant CTLA-4-IgG2 fusion proteins include those comprising a polypeptide
sequence
identified by any of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222. If
desired, the
amino acids of a mature mutant CTLA-4-IgG2 fusion protein can be numbered
beginning
with the first amino acid residue of the mutant CTLA-4-IgG2 (i.e., the first
residue of the
mutant CTLA-4 ECD polypeptide). In some aspects, the first residue of the
mutant
CTLA-4-IgG2 fusion protein (or mutant CTLA-4 ECD) is methionine and thus the
numbering of amino acids of the mutant CTLA-4-IgG2 fusion protein (or mutant
CTLA-4
ECD) would begin with methionine (designated as amino acid residue 1).
The invention also includes isolated or recombinant multimeric fusion proteins
comprising two or more mutant CTLA-4-Ig fusion proteins described above. In
some
instances, the multimer is a fusion protein dimer comprising two mutant CTLA-4-
Ig
fusion proteins, which may be identical fusion proteins (i.e., homodimer) or
different
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fusion proteins (i.e., heterodimer). In some instances, the multimer is a
tetrameric fusion
protein, which comprises four mutant CTLA-4-ECD polypeptides of the invention.
The
tetramer can comprise four identical mutant CTLA-4 ECD polypeptides (i.e.,
homotetramer) or any combination of four mutant CTLA-4 ECD polypeptides of the
invention such that all four mutant CTLA-4 ECD polypeptides are not identical
(i.e.,
heterotetramer). Some such multimers bind CD80 and/CD86 (and/or hCD80-Ig
and/or
hCD86-Ig) and/or suppress or inhibit an immune response.
The invention includes soluble forms of any of the polypeptides, fusion
proteins,
and multimers described above. Also included are soluble forms on the
conjugate of the
invention described below. Soluble molecules of the invention ¨ e.g., soluble
polypeptides, dimeric fusion proteins, monomeric fusion proteins, multimers,
and
conjugates of the invention ¨ are not linked or joined or bound to a cell.
Some such
soluble molecules may be in solution or are capable of circulating, e.g., in a
fluid (e.g., in a
subject's body). A signal peptide may typically be used to facilitate
secretion of such a
molecule, but the signal peptide is cleaved during secretion of the molecule
from a host
cell. Thus, in most instances, a soluble molecule, such as a soluble
polypeptide, dimeric
fusion protein, monomeric fusion protein, or multimer, does not include a
signal peptide.
As discussed above, a mutant CTLA-4 extracellular domain polypeptide of the
invention
can be linked to an Ig molecule, including, e.g., a portion of an Ig
polypeptide, such as,
e.g., an Ig Fc polypeptide, which results in a soluble fusion protein. Thus,
in one aspect,
the invention includes soluble mutant CTLA-4-Ig fusion proteins which comprise
any
mutant CTLA-4 ECD polypeptide of the invention as described herein fused or
linked to
at least a portion of an Ig polypeptide, such as, e.g., a wild-type Ig Fc
(e.g., human IgG2
Fc) or mutant Ig Fc polypeptide. Such soluble mutant CTLA-4-Ig fusion proteins
may be
monomeric or dimeric fusion proteins and include those mutant CTLA-4-Ig fusion
protein
monomers and dimers described in detail above and elsewhere, including in the
Examples
below. As described in detail above and elsewhere herein, some such soluble
monomeric
and dimeric fusion proteins may have an ability to bind CD80 and/or CD86
and/or an
ability to suppress or inhibit an immune response (e.g., T cell activation or
proliferation) in
in vitro and/or in vivo applications.
Such soluble molecules of the invention are expected to be of particular
benefit in
a variety of applications, including, e.g., therapeutic and prophylactic
methods for treating
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immune system diseases and disorders (e.g., autoimmune diseases) and
prophylactic and
therapeutic methods for inhibiting cell, organ or tissue graft
transplantation. Soluble
molecules of the invention ¨ e.g., soluble recombinant mutant CTLA-4 ECD
polypeptides,
monomeric and dimeric mutant CTLA-4-Ig fusion proteins, mutant CTLA-4 ECD
conjugates, mutant CTLA-4-Ig conjugates, multimers comprising mutant CTLA-4
ECD
polypeptides or mutant CTLA-4-Ig, multimers comprising mutant CTLA-4
conjugates or
mutant CTLA-4-Ig conjugates of the invention ¨ which bind CD80 and/or CD86,
when
administered to a subject in a therapeutically or prophylactically effective
amount, inhibit
the interaction between endogenous CD80 and/or CD86 and endogenous CD28,
thereby
suppressing in the subject an immune system response or immune system attack
on the
subject's healthy body tissues, organs, and/or cells. In instances where a
subject is the
recipient of healthy body tissues, organs, and/or cells from a donor (e.g.,
such as where the
subject recipient has received a donor tissue graft or cell or organ
transplant), such soluble
molecules inhibit the interaction between endogenous CD80 and/or CD86 and
endogenous
CD28, thereby inhibiting a harmful response or attack by the subject's immune
system on
the healthy body tissues, organs, or cells donated to the subject by the
donor. By
suppressing an immune system response or attack on healthy body tissues, the
side effects
(e.g., pain, joint inflammation, etc.) associated with such immune system
response or
attack on healthy tissues, organs, or cells in the subject can be decreased,
and the damage
resulting from such a response or attack can be retarded or prevented.
Methods for measuring binding affinities and avidities of polypeptides of the
invention described above, including, e.g., mutant CTLA-4 ECD polypeptides,
dimeric
and monomeric mutant CTLA-4-Ig fusion proteins, and multimers of the invention
would
be known to those of ordinary skill in the art and include, e.g., but are not
limited to,
Biacorei'm technology (GE Healthcare), isothermal titration microcalorimetry
(MicroCal
LLC, Northampton, MA), ELISA, binding affinity phage display methods, and FACS
methods. Biacore methods are described in detail in Example 4 below. FACS or
other
sorting methods are described in greater detail above and elsewhere herein.
Methods for
measuring binding avidities of polypeptides of the invention to hCD80 and/or
hCD86 by
phage ELISA are described in Example 2 below.
Methods for detecting and measuring T cell responses induced by molecules of
the
invention (including, e.g., mutant CTLA-4 ECD polypeptides, dimeric and
monomeric
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mutant CTLA-4-Ig fusion proteins, and multimers of the invention) are well
known to
those skilled in the art. T cell activation is commonly characterized by
physiological
events including, e.g., T cell-associated cytokine synthesis (e.g., IFN-y
production) and
induction of activation markers (e.g., CD25, IL-2 receptor). CD4+ T cells
recognize their
immunogenic peptides in the context of MHC class II molecules, whereas CD8+ T
cells
recognize their immunogenic peptides in the context of MHC class I molecules.
Exemplary methods for assessing and measuring the ability of molecules of the
invention
described above to inhibit or suppress T cell activation and/or T cell
proliferation or to
block signaling through CD86 and/or CD80 are described in Examples 5-8 and
elsewhere
herein.
Polypeptides, monomeric and dimeric fusion proteins, and multimers of the
invention, including those discussed above, optionally further comprise an
additional
amino acid, such as a methionine, added to the N-terminus and/or a peptide tag
for
purification or identification. Polypeptides of the invention, including those
discussed
above, optionally further comprise a polypeptide purification subsequence,
such as, e.g., a
subsequence is selected from an epitope tag, a FLAG tag, a polyhistidine
sequence, and a
GST fusion.
In addition, as discussed in greater detail below, the invention includes
isolated,
recombinant, or synthetic nucleic acids encoding all polypeptides, fusion
proteins, and
multimers of the invention described above and in additional detail below.
Sequence Identity
As discussed above, in one aspect, the invention includes an isolated or
recombinant polypeptide which comprises a polypeptide sequence having at least
85%,
86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%,
or 100% sequence identity to a polypeptide sequence selected from the group
consisting of
SEQ ID NOS:1-73, wherein the polypeptide binds CD80 or CD86 or an
extracellular
domain of either and/or has an ability to suppress or inhibit an immune
response. In
another aspect, as described in detail below, the invention provides an
isolated or
recombinant nucleic acid comprising a polynucleotide sequence that encodes a
polypeptide comprising a polypeptide sequence having at least 75%, 80%, 85%,
86%,
87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or
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100% sequence identity to at least one polypeptide sequence selected from the
group
consisting of SEQ ID NOS:1-73, wherein the polypeptide has an ability to bind
CD80
and/or CD86 and/or an ECD thereof, and/or has an ability to suppress an immune
response, or a complementary polynucleotide sequence thereof.
The degree to which a sequence (polypeptide or nucleic acid) is similar to
another
provides an indication of similar structural and functional properties for the
two
sequences. Accordingly, in the context of the present invention, sequences
that have a
similar sequence to any given exemplar sequence are a feature of the present
invention.
Sequences that have percent sequence identities as defined below are a feature
of the
invention. A variety of methods of determining sequence relationships can be
used,
including manual alignment and computer assisted sequence alignment and
analysis. A
variety of computer programs for performing sequence alignment are available,
or can be
produced by one of skill.
As noted above, the sequences of the nucleic acids and polypeptides employed
in
the subject invention need not be identical, but can be substantially
identical to the
corresponding sequence of a nucleic acid of the invention or polypeptide of
the invention,
respectively. For example, polypeptides of the invention can be subject to
various
changes, such as one or more amino acid insertions, deletions, and/or
substitutions, either
conservative or non-conservative, including where, e.g., such changes might
provide for
certain advantages in their use, such as, in their therapeutic or prophylactic
use or
administration or diagnostic application. The nucleic acids of the invention
can also be
subject to various changes, such as one or more substitutions of one or more
nucleic acids
in one or more codons such that a particular codon encodes the same or a
different amino
acid, resulting in either a silent variation (e.g., mutation in a nucleotide
sequence results in
a silent mutation in the amino acid sequence, e.g., when the encoded amino
acid is not
altered by the nucleic acid mutation) or non-silent variation, one or more
deletions of one
or more nucleic acids (or codons) in the sequence, one or more additions or
insertions of
one or more nucleic acids (or codons) in the sequence, cleavage of or one or
more
truncations of one or more nucleic acids (or codons) in the sequence. The
nucleic acids
can also be modified to include one or more codons that provide for optimum
expression
in an expression system (e.g., bacterial or mammalian), while, if desired,
said one or more
codons still encode the same amino acid(s). Such nucleic acid changes might
provide for
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certain advantages in their therapeutic or prophylactic use or administration,
or diagnostic
application. The nucleic acids and polypeptides can be modified in a number of
ways so
long as they comprise a sequence substantially identical (as defined below) to
a sequence
in a respective nucleic acid or polypeptide of the invention.
The term "identical" or "identity," in the context of two or more nucleic acid
or
polypeptide sequences, refers to two or more sequences that are the same or
have a
specified percentage of amino acid residues or nucleotides that are the same,
when
compared and aligned for maximum similarity, as determined using the sequence
comparison algorithm described below or by visual inspection. The "percent
sequence
identity" ("% identity") of a subject sequence to a reference (i.e. query)
sequence means
that the subject sequence is identical (i.e., on an amino acid-by-amino acid
basis for a
polypeptide sequence, or a nucleotide-by-nucleotide basis for a polynucleotide
sequence)
by a specified percentage to the query sequence over a comparison length.
The percent sequence identity (-% sequence identity" or "% identity") of a
subject
sequence to a query sequence can be calculated as follows. First, the optimal
alignment of
the two sequences is determined using a sequence comparison algorithm with
specific
alignment parameters. This determination of the optimal alignment may be
performed
using a computer, or may be manually calculated, as described below. Then, the
two
optimally aligned sequences are compared over the comparison length, and the
number of
positions in the optimal alignment at which identical residues occur in both
sequences are
determined, which provides the number of matched positions. The number of
matched
positions is then divided by the total number of positions of the comparison
length (which,
unless otherwise specified, is the length of the query sequence), and then
multiplying the
result by 100, to yield the percent sequence identity of the subject sequence
to the query
sequence.
With regard to polypeptide sequences, typically one sequence is regarded as a
"query sequence" (for example, a polypeptide sequence of the invention) to
which one or
more other sequences, i.e., "subject sequence(s)" (for example, sequences
present in a
sequence database) are compared. The sequence comparison algorithm uses the
designated alignment parameters to determine the optimal alignment between the
query
sequence and the subject sequence(s). When comparing a query sequence against
a
sequence database, such as, e.g., GENBANK database (Genetic Sequence Data
Bank;
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U.S. Department of Health and Human Services) or GENESEQ database (Thomson
Derwent; also available as DGENE database on STN), usually only the query
sequence
and the alignment parameters are input into the computer; optimal alignments
between the
query sequence and each subject sequence are returned for up to a specified
number of
subject sequences.
1. Determining the Optimal Alignment
Two polypeptide sequences are "optimally aligned" when they are aligned using
defined parameters, i.e., a defined amino acid substitution matrix, gap
existence penalty
(also termed gap open penalty), and gap extension penalty, so as to arrive at
the highest
similarity score possible for that pair of sequences. The BLOSUM62 matrix
(Henikoff
and Henikoff (1992) Proc. Natl. Acad. Sci. USA 89(22):10915-10919) is often
used as a
default scoring substitution matrix in polypeptide sequence alignment
algorithms (such as
BLASTP, described below). The gap existence penalty is imposed for the
introduction of a
single amino acid gap in one of the aligned sequences, and the gap extension
penalty is
imposed for each residue position in the gap. Unless otherwise stated,
alignment
parameters employed herein are: BLOSUM62 scoring matrix, gap existence penalty
= 11,
and gap extension penalty = 1. The alignment score is defined by the amino
acid positions
of each sequence at which the alignment begins and ends (e.g., the alignment
window),
and optionally by the insertion of a gap or multiple gaps into one or both
sequences, so as
to arrive at the highest possible similarity score.
While optimal alignment between two or more sequences can be determined
manually (as described below), the process is facilitated by the use of a
computer-
implemented alignment algorithm such as BLAST (National Library of Medicine),
e.g.,
BLASTP for polypeptide sequences and BLASTN for nucleic acid sequences,
described in
Altschul et al. (1997) Nucleic Acids Res. 25:3389-3402, and made available to
the public
through various sources, such as the National Center for Biotechnology
Information
(NCBI) website. When using a computerized BLAST interface, if the option
exists to use
a "low complexity filter", this option should be turned off (i.e., no filter).
The optimal alignment between two polypeptide sequences can also be determined
by a manual calculation of the BLASTP algorithm (i.e., without aid of a
computer) using
the same alignment parameters specified above (matrix = BLOSUM62, gap open
penalty
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11, and gap extension penalty = 1). To begin, the two sequences are initially
aligned by
visual inspection. An initial alignment score is then calculated as follows:
for each
individual position of the alignment (i.e., for each pair of aligned
residues), a numerical
value is assigned according to the BLOSUM62 matrix (Figure 13). The sum of the
values
assigned to each pair of residues in the alignment is the alignment score. If
the two
sequences being aligned are highly similar, often this initial alignment
provides the highest
possible alignment score. The alignment with the highest possible alignment
score is the
optimal alignment based on the alignment parameters employed.
Examples of the manual calculation of alignment scores for two sequences are
provided in Figures 14A-14D. Figure 14A shows is the calculation of an
alignment score
for an arbitrary alignment (alignment 14A) of a "query" sequence, identified
herein as
residues 39-53 of the human CTLA-4 ECD sequence (SEQ ID NO:159), and a
"subject"
sequence, identified herein as residues 40-54 of D3 (SEQ ID NO:61). The
numerical value
assigned by the BLOSUM62 matrix for each aligned pair of amino acids is shown
beneath
each position in the alignment.
Figure 14B shows the alignment score for the optimal alignment of the same two
sequences. To aid in visualization, each identical pair of amino acids in the
alignment is
shown in boldface. The alignment in Figure 14B (alignment 14B) below results
in the
highest possible alignment score (the sum of the values shown beneath each
aligned
position) of these two sequences; any other alignment of these two sequences,
with or
without gaps, would result in a lower alignment score.
In some instances, a higher alignment score might be obtained by introducing
one
or more gaps into the alignment. Whenever a gap is introduced into an
alignment, a Rap
open penalty is assigned, and in addition a gap extension penalty is assessed
for each
residue position within that gap. Therefore, using the alignment parameters
described
above (including gap open penalty = 11 and gap extension penalty = 1), a gap
of one
residue in the alignment would correspond to a value of - (11+(1 x 1)) = -12
assigned to
the gap; a gap of two residues would correspond to a value of - (11+(2 x 1)) =
-13
assigned to the gap, and so on. This calculation is repeated for each new gap
introduced
into the alignment.
The following is an example, which demonstrates how introduction of a gap into
an alignment can result in a higher alignment score, despite the gap penalty.
Figure 14C
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shows an alignment (alignment 14C) of a "query" sequence, identified herein as
residues
39-53 of the human CTLA-4 ECD sequence (SEQ ID NO:159), and a -subject"
sequence,
identified herein as residues 41-55 of D3 (SEQ ID NO:61), but in this instance
with amino
acids 49-50 deleted. Alignment 14C, which is the best possible alignment
without
introduction of any gaps, results in an alignment score of 34.
The alignment in Figure 14D (alignment 14D) shows the effect of the
introduction
of a two-residue gap in the lower sequence on the alignment score. Despite the
total gap
penalty of 13 (the gap open penalty of 11, and 2 times the gap extension
penalty of 1), the
overall alignment score of the two sequences increases to 43. Alignment D
below results
in the highest possible alignment score, and is thus the optimal alignment of
these two
sequences; any other alignment of these two sequences (with or without gaps)
would result
in a lower alignment score.
It is to be understood that the examples of sequence alignment calculations
described above, which use relatively short sequences, are provided for
illustrative
purposes only. In practice, the alignment parameters employed (BLOSUM62
matrix, gap
open penalty = 11, and gap extension penalty = 1) are generally intended for
polypeptide
sequences 85 amino acids in length or longer. The NCBI website provides the
following
alignment parameters for sequences of other lengths, which are suitable for
computer-
aided as well as manual alignment calculation, using the same procedure as
described
above. For sequences of 50-85 amino acids in length, optimal parameters are
the
BLOSUM80 matrix (Henikoff and Henikoff, supra), gap open penalty = 10, and gap
extension penalty = 1. For sequences of 35-50 amino acids in length, optimal
parameters
are the PAM70 matrix (Dayhoff, M.O., Schwartz, R.M. & Orcutt, B.C. (1978) "A
model
of evolutionary change in proteins" in Atlas of Protein Sequence and
Structure, vol. 5,
suppl. 3, M.O. Dayhoff (ed.), pp. 345-352, Natl. Biomed. Res. Found.,
Washington, DC.),
gap open penalty = 10, and gap extension penalty = 1. For sequences of less
than 35
amino acids in length, optimal parameters are PAM30 matrix (Dayhoff, M.O.,
supra), gap
open penalty = 9, and gap extension penalty = 1.
2. Calculating Percent Identity
Once the sequences are optimally aligned, the percent identity of the subject
sequence relative to the query sequence is calculated by counting the number
of positions
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in the optimal alignment which contain identical residue pairs, divide that by
the number
of residues in the comparison length (also termed the comparison window),
which, unless
otherwise specified, is the number of residues in the query sequence, and
multiplying the
resulting number by 100. Referring back to the alignments above, in each
example the
sequence designated as the query (upper) sequence is 15 amino acids in length.
In
alignment B, 12 pairs of aligned amino acid residues (shown in boldface) are
identical in
the optimal alignment of the query sequence (upper) with the subject sequence
(lower).
Thus, this particular subject sequence has (12/15) x 100 = 80% identity to the
entire length
of the 15-residue query sequence; in other words, the subject sequence in
alignment B has
at least 80% amino acid sequence identity to the query sequence. In alignment
D, 11 pairs
of amino acid residues (shown in boldface) in the optimal alignment are
identical; thus this
particular subject sequence has (11/15) x 100 = 73.3% identity to the entire
length of the
15-residue query sequence; in other words, the subject sequence in alignment D
has at
least 73% amino acid sequence identity to the query sequence.
As applied to polypeptides, the term "substantial identity" (or -substantially
identical") typically means that when two amino acid sequences (i.e. a query
sequence and
a subject sequence) are optimally aligned using the BLASTP algorithm (manually
or via
computer) using appropriate parameters described above, the subject sequence
has at least
70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,
97%, 98%, 99%, 99.5% or 100% amino acid sequence identity to the query
sequence. In
some instances, the substantial identity exists over a comparison length of at
least 100
amino acid residues, such as, e.g., at least 110, 115, 118, 119, 120, 121,
122, 123, 124,
125, 130, 135, 140, 145, 150, 200, 250, 300, 345, 346, 347, 348, 349, 350,
351, 352, 353,
354, 355, 356, 357, 358, 359, 360, 375, 400, 450, or 500 amino acid residues.
Similarly, as applied in the context of two nucleic acid sequences, the term
substantial identity (or substantially identical) means that when two nucleic
acid sequences
(i.e. a query and a subject sequence) are optimally aligned using the BLASTN
algorithm
(manually or via computer) using appropriate parameters described below, the
subject
sequence has at least about 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%,
96%, 97%, 98%, 99%, 99.5% or 100% nucleic acid sequence identity to the query
sequence. Parameters used for nucleic acid sequence alignments are: match
reward 1,
mismatch penalty -3, gap existence penalty 5, gap extension penalty 2
(substitution
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matrices are not used in the BLASTN algorithm). In some instances, substantial
identity
exists over a comparison length of at least 300 nucleotide residues, e.g., at
least 330, 345,
354, 357, 360, 363, 366, 369, 362, 365, 375, 390, 405, 420, 435, 450, 600,
750, 900, 1035,
1038, 1041, 1044, 1047, 1050, 1053, 1056, 1059, 1062, 1065, 1068, 1071, 1074,
1077,
1080, 1200, 1350, or 1500 nucleotide residues.
Other sequence alignment programs known in the art can be used. The ALIGN
program produces an optimal global (overall) alignment of the two chosen
protein or
nucleic acid sequences using a modification of the dynamic programming
algorithm
described by Myers and Miller CABIOS 4:11-17 (1988). The ALIGN program
typically,
although not necessary, is used with weighted end-gaps. If gap opening and gap
extension
penalties are available, they are often set between about -5 to -15 and 0 to -
3, respectively,
more preferably about -12 and -0.5 to -2, respectively, for amino acid
sequence
alignments, and -10 to -20 and -3 to -5, respectively, more commonly about -16
and -4,
respectively, for nucleic acid sequence alignments. The ALIGN program is
further
described in Pearson et al., Proc. Natl. Acad. Sci. USA 85:2444-48 (1988), and
Pearson et
al., Meth. Enzymol. 18:63-98 (1990).
Alternatively, and particularly for multiple sequence analysis (i.e.,
comparison of
more than three sequences), the CLUSTALW program (described in, e.g., Thompson
et
al., Nucl. Acids Res. 22:4673-4680 (1994)) can be used. The CLUSTALW program
is an
algorithm suitable for multiple DNA and amino acid sequence alignments
(Thompson et
al., Nucl. Acids Res. 22:4673-4680 (1994)). CLUSTALW performs multiple
pairwise
comparisons between groups of sequences and assembles them into a multiple
alignment
based on homology. In one aspect, Gap open and Gap extension penalties are set
at 10
and 0.05, respectively. Alternatively or additionally, the CLUSTALW program is
run
using "dynamic" (versus "fast") settings. Typically, nucleotide sequence
analysis with
CLUSTALW is performed using the BESTFIT matrix, whereas amino acid sequences
are
evaluated using a variable set of BLOSUM matrixes depending on the level of
identity
between the sequences (e.g., as used by the CLUSTALW version 1.6 program
available
through the San Diego Supercomputer Center (SDSC) or version W 1.8 available
from
European Bioinformatics Institute, Cambridge, UK). Preferably, the CLUSTALW
settings are set to the SDSC CLUSTALW default settings (e.g., with respect to
special
hydrophilic gap penalties in amino acid sequence analysis). The CLUSTALW
program is
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further described in, e.g., Higgins et al., CABIOS 8(2):189-91 (1992),
Thompson et al.,
Nucleic Acids Res. 22:4673-80 (1994), and Jeanmougin et al., Trends Biochem.
Sci.
2:403-07 (1998).
In an alternative format, the identity or percent identity between a
particular pair of
aligned amino acid sequences refers to the percent amino acid sequence
identity that is
obtained by CLUSTALW analysis (e.g., version W 1.8), counting the number of
identical
matches in the alignment and dividing such number of identical matches by the
greater of
(i) the length of the aligned sequences, and (ii) 96, and using the following
default
ClustalW parameters to achieve slow/accurate pairwise alignments ¨ Gap Open
Penalty:10; Gap Extension Penalty:0.10; Protein weight matrix:Gonnet series;
DNA
weight matrix: TUB; Toggle Slow/Fast pairwise alignments = SLOW or FULL
Alignment.
Another useful algorithm for determining percent identity or percent
similarity is
the FASTA algorithm, which is described in Pearson et al., Proc Natl. Acad.
Sci. USA
85:241111 (1988) and Pearson, Methods Enzymol. 266:227-258 (1996). Typical
parameters
used in a FASTA alignment of DNA sequences to calculate percent identity are
optimized,
BL50 Matrix 15: -5, k-tuple = 2; joining penalty = 40, optimization = 28; gap
penalty = -
12, gap length penalty = -2; and width = 16.
Other suitable algorithms include the BLAST and BLAST 2.0 algorithms, which
facilitate analysis of at least two amino acid or nucleotide sequences, by
aligning a
selected sequence against multiple sequences in a database (e.g., GenSeq), or,
when
modified by an additional algorithm such as BL2SEQ, between two selected
sequences.
Software for performing BLAST analyses is publicly available through the
National
Center for Biotechnology Information (NCBI) (worldwide website address
ncbi.nlm.nih.gov). The BLAST algorithm involves first identifying high scoring
sequence
pairs (HSPs) by identifying short words of length W in the query sequence,
which either
match or satisfy some positive-valued threshold score T when aligned with a
word of the
same length in a database sequence. T is referred to as the neighborhood word
score
threshold (Altschul et al., supra). These initial neighborhood word hits act
as seeds for
initiating searches to find longer HSPs containing them. The word hits are
extended in
both directions along each sequence for as far as the cumulative alignment
score can be
increased. Cumulative scores are calculated using, for nucleotide sequences,
the
parameters M (reward score for a pair of matching residues; always > 0) and N
(penalty
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score for mismatching residues; always <0). For amino acid sequences, a
scoring matrix
is used to calculate the cumulative score. Extension of the word hits in each
direction are
halted when: the cumulative alignment score falls off by the quantity X from
its maximum
achieved value; the cumulative score goes to zero or below, due to the
accumulation of
one or more negative-scoring residue alignments; or the end of either sequence
is reached.
The BLAST algorithm parameters W, T, and X determine the sensitivity and speed
of the
alignment. The BLASTN program (for nucleotide sequences) can be used with a
word
length (W) of 11, an expectation (E) of 10, M.5, N.-4 and a comparison of both
strands.
For amino acid sequences, the BLASTP program (e.g., BLASTP 2Ø14; Jun-29-
2000) can
be used with a word length of 3 and an expectation (E) of 10. The BLOSUM62
scoring
matrix (see Henikoff & Henikoff, (1989) Proc. Natl. Acad. Sci. USA 89:10915)
uses
alignments (B) of 50, expectation (E) of 10, M=5, N=-4, and a comparison of
both strands.
Again, as with other suitable algorithms, the stringency of comparison can be
increased
until the program identifies only sequences that are more closely related to
those in the
sequence listing herein (e.g., a polypeptide comprising a polypeptide sequence
having at
least 85, 90, 91, 92, 93, 49, 95, 96, 97, 98, 99%, or 100% identity to a
polypeptide
sequence selected from SEQ ID NOS:1-79, 197-200, 205-214, and 219-222; or
nucleic
acid comprising a nucleotide sequence having at least 85. 90, 91, 92, 93, 49,
95, 96, 97,
98, 99%, or 100% identity to a nucleotide sequence selected from any of SEQ ID
NOS:80-
158, 201-204, 223, and 224, or a complementary nucleotide sequence thereof.
The BLAST algorithm also performs a statistical analysis of the similarity or
identity between two sequences (see, e.g., Karlin & Altschul, (1993) Proc.
Natl. Acad. Sci.
USA 90:5873-5787). One measure of similarity or identity provided by the BLAST
algorithm is the smallest sum probability (P(N)), which provides an indication
of the
probability by which a match between two nucleotide or amino acid sequences
would
occur by chance. For example, a nucleic acid is considered similar to a
reference sequence
if the smallest sum probability in a comparison of the test nucleic acid to
the reference
nucleic acid is less than about 0.2, such as less than about 0.01 or less than
about 0.001.
BLAST program analysis also or alternatively can be modified by low complexity
filtering programs such as the DUST or SEG programs, which are preferably
integrated
into the BLAST program operations (see, e.g., Wootton et al., Comput. Chem.
17:149-63
(1993), Altschul et al., Nat. Genet. 6:119-29 (1991), Hancock et al., Comput.
Appl. Biosci.
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10:67-70 (1991), and Wootton et al., Meth. Enzymol. 266:554-71 (1996)). In
such
aspects, if a lambda ratio is used, useful settings for the ratio are between
0.75 and 0.95,
including between 0.8 and 0.9. If gap existence costs (or gap scores) are used
in such
aspects, the gap existence cost typically is set between about -5 and -15,
more typically
about -10, and the per residue gap cost typically is set between about 0 to -
5, such as
between 0 and -3 (e.g., -0.5). Similar gap parameters can be used with other
programs as
appropriate. The BLAST programs and principles underlying them are further
described
in, e.g., Altschul et al., J. Mol. Biol. 215:403-10 (1990). Karlin and
Altschul, Proc. Natl.
Acad. Sci. USA 87:2264-68 (199) (as modified by Karlin and Altschul, Proc.
Natl. Acad.
Sci. USA 90:5873-77 (1993)), and Altschul et al., Nucl. Acids Res. 25:3389-
3402 (1997).
Another example of a useful algorithm is incorporated in PILEUP software. The
PILEUP program creates a multiple sequence alignment from a group of related
sequences
using progressive, pair-wise alignments to show relationship and percent
sequence identity
or percent sequence similarity. PILEUP uses a simplification of the
progressive alignment
method of Feng & Doolittle (1987) J. Mol. Evol. 35:351-360, which is similar
to the
method described by Higgins & Sharp (1989) CABIOS 5:151-153. The program can
align
up to 300 sequences, each of a maximum length of 5,000 nucleotides or amino
acids. The
multiple alignment procedure begins with the pairwise alignment of the two
most similar
sequences, producing a cluster of two aligned sequences. This cluster is then
aligned to
the next most related sequence or cluster of aligned sequences. Two clusters
of sequences
are aligned by a simple extension of the pairwise alignment of two individual
sequences.
The final alignment is achieved by a series of progressive, pairwise
alignments. The
program is run by designating specific sequences and their amino acid or
nucleotide
coordinates for regions of sequence comparison and by designating the program
parameters. Using PILEUP, a reference sequence is compared to other test
sequences to
determine the percent sequence identity (or percent sequence similarity)
relationship using
specified parameters. Exemplary parameters for the PILEUP program are: default
gap
weight (3.00), default gap length weight (0.10), and weighted end gaps. PILEUP
is a
component of the GCG sequence analysis software package, e.g., version 7.0
(Devereaux
et al. (1984) Nucl. Acids Res. 12:387-395).
Other useful algorithms for performing identity analysis include the local
homology algorithm of Smith and Waterman (1981) Adv. Appl. Math. 2:482, the
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homology alignment algorithm of Needleman and Wunsch (1970) J. Mol. Biol.
48:443,
and the search for similarity method of Pearson and Lipman (1988) Proc. Natl.
Acad. Sci.
USA 85:2444. Computerized implementations of these algorithms (e.g., GAP,
BESTFIT,
FASTA and TFASTA) are provided in the Wisconsin Genetics Software Package
Release
7.0, Genetics Computer Group, 575 Science Dr., Madison, WI.
Sequence Variation
As discussed above, in one aspect, the invention provides an isolated or
recombinant mutant CTLA-4 extracellular domain polypeptide which comprises a
polypeptide sequence which (a) differs from a polypeptide sequence selected
from the
group consisting of SEQ ID NOS:1-73 in no more than 6 amino acid residues
(e.g., no
more than 1, 2, 3, 4, 5, or 6 amino acid residues), wherein the mutant CTLA-4
ECD
polypeptide binds CD80 and/or CD86 and/or an extracellular domain of either or
both,
and/or inhibits an immune response. Such amino acid substitution(s) include
conservative
amino acid substitution(s).
As a non-limiting example, a polypeptide of the invention may have a
polypeptide
sequence which differs from SEQ D NO:1 in a total of up to 6 amino acids
(which may
be a combination of amino acid substitutions, deletions, and/or insertions,
including those
described above). In some instances, none, some, or all of the substitutions
are
substitutions according to a substitution group defined below.
Amino acid substitutions in accordance with the invention may include, but are
not
limited to, one or more conservative amino acid substitutions. A conservative
amino acid
residue substitution typically involves exchanging a member within one
functional class of
amino acid residues for a residue that belongs to the same functional class
(identical amino
acid residues are considered functionally homologous or conserved in
calculating percent
functional homology). Conservative substitution tables providing functionally
similar
amino acids are well known in the art. One example is provided in Table 1,
which sets
forth six exemplary groups containing amino acids that may be considered
"conservative
substitutions" for one another.
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Table 1. Conservative Amino Acid Residue Substitution Groups
1 Alanine (A) Glycine (G) Serine (S) Threonine (T)
2 Aspartic acid (D) Glutamic acid (E)
3 Asparagine (N) Glutamine (Q)
4 Arainine (R) Lysine (K) Histidine (H)
Isoleucine (I) Leucine (L) Methionine (M) Valine (V)
6 Phenylalanine (F) Tyrosine (Y) Tryptophan (W)
5 Other substitution groups of amino acids can be envisioned. For example,
amino
acids can be grouped by similar function or chemical structure or composition
(e.g., acidic,
basic, aliphatic, aromatic, sulfur-containing). For example, an Aliphatic
grouping may
comprise: Glycine (G), Alanine (A), Valine (V), Leucine (L), Isoleucine (I).
Other
*groups containing amino acids that are considered conservative substitutions
for one
another include: Aromatic: Phenylalanine (F), Tyrosine (Y), Tryptophan (W);
Sulfur-
containing: Methionine (M), Cysteine (C); Basic: Arginine (R), Lysine (K),
Histidine (H);
Acidic: Aspartic acid (D), Glutamic acid (E); Non-polar uncharged residues,
Cysteine (C),
Methionine (M), and Proline (P); Hydrophilic Uncharged Residues: Serine (S),
Threonine
(T). Asparagine (N), and Glutamine (Q). See also Creighton (1984) Proteins, W
.H.
Freeman and Company, for additional groupings of amino acids. Listing of a
polypeptide
sequence herein, in conjunction with the above substitution groups, provides
an express
listing of all conservatively substituted polypeptide sequences.
More conservative substitutions exist within the amino acid residue classes
described above, which also or alternatively can be suitable. Conservation
groups for
substitutions that are more conservative include: valine-leucine-isoleucine,
phenylalanine-
tyrosine, lysine-arginine, alanine-valine, and asparagine-glutamine. Thus, for
example, in
one particular aspect, the invention provides an isolated or recombinant
polypeptide
comprising a polypeptide sequence which has at least 90, 91, 92, 93, 94, 95,
96, 97, 98, or
99% identity to SEQ ID NO:1 (or any of SEQ ID NOS:1-79, 197-200, 205-214, and
219-
222) and which differs from the sequence of SEQ ID NO:1 by mostly (e.g., at
least 50%,
60%, 70%, 75%, 80%, 90% ), if not entirely, by such more conservative amino
acid
substitutions.
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Additional groups of amino acids substitutions that also can be suitable can
be
determined using the principles described in. e.g., Creighton (1984) PROTEINS:
STRUCTURE
AND MOLECULAR PROPERTIES (2d Ed. 1993), W.H. Freeman and Company. In some
aspects, at least 33%, 50%. 60%, 70%, or more (e.g., at least 75%, 80%, 90%,
95%, 96%,
97% or more) of the substitutions in an amino acid sequence variant comprise
substitutions of one or more amino acid residues in a polypeptide sequence of
the
invention with residues that are within the same functional homology class (as
determined
by any suitable classification system, such as those described above) as the
amino acid
residues of the polypeptide sequence that they replace.
Conservatively substituted variations of a polypeptide sequence of the present
invention include substitutions of a small percentage, typically less than
10%, 9%, 8%,
7%, or 6% of the amino acids of the polypeptide sequence, or more typically
less than 5%,
4%, 3%, 2%, or 1%, of the amino acids of the polypeptide sequence, with a
conservatively
selected amino acid of the same conservative substitution group.
The invention includes polypeptides that comprise amino acid variations of a
polypeptide sequence of the invention described herein. As discussed above, in
one
aspect, the invention provides isolated or recombinant polypeptides (e.g.,
mutant CTLA-4
polypeptides, such as, e.g., mutant CTLA-4 ECD polypeptides) which each
comprise a
polypeptide sequence having at least 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%,
91%,
92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 100% sequence identity to at
least one polypeptide sequence selected from the group consisting of SEQ ID
NOS:1-73,
wherein the polypeptide binds CD80 and/or CD86 or a polypeptide fragment of
CD80
and/or CD86 (or an ECD of either or both), and/or suppresses an immune
response. Such
polypeptides may vary by one or more amino acid deletions, additions, or
substitutions,
including one or more conservative or non-conservative substitutions,
provided, however,
that the polypeptides possess the described functional properties. In a
particular aspect,
the invention provides polypeptide variants that comprise conservatively
modified
variations of any such polypeptide described herein, such as, e.g., one
comprising a
polypeptide sequence selected from the group of SEQ ID NOS:1-73.
As also discussed above, in another aspect, the invention provides isolated or
recombinant fusion proteins (e.g., mutant CTLA-4-Ig fusion proteins) which
each
comprise a polypeptide sequence having at least 75%, 80%, 85%, 86%, 87%, 88%,
89%.
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90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 100% sequence
identity to at least one polypeptide sequence selected from the group
consisting of SEQ ID
NOS:74-79, 197-200, 205-214, and 219-222, wherein the fusion protein binds
CD80
and/or CD86 (and/or CD80-Ig and/or CD86-Ig), and/or suppresses an immune
response.
Such fusion proteins may vary by one or more amino acid deletions, additions,
or
substitutions, including one or more conservative or non-conservative
substitutions,
provided, however, that the fusion proteins possess the described functional
properties. In
a particular aspect, the invention provides polypeptide variants that comprise
conservatively modified variations of any such fusion protein described
herein, such as,
e.g., one comprising a polypeptide sequence selected from the group of SEQ ID
NOS:74-
79, 197-200, 205-214, and 219-222.
Also provided are polypeptide variants of any isolated or recombinant
polypeptide
of the invention described above or elsewhere herein, wherein the amino acid
sequence of
the polypeptide variant differs from the respective polypeptide sequence of
the reference
polypeptide by one or more conservative amino acid residue substitutions,
although non-
conservative substitutions are sometimes permissible or even preferred
(examples of such
non-conservative substitutions are discussed further herein). For example, the
sequence of
the polypeptide variant can vary from a mutant CTLA-4 polypeptide sequence by
one or
more substitutions of amino acid residues in the mutant CTLA-4 ECD polypeptide
sequence with one or more amino acid residues having similar weight (i.e., a
residue that
has weight homology to the residue in the respective polypeptide sequence that
it
replaces). The weight (and correspondingly the size) of amino acid residues of
a
polypeptide can significantly impact the structure of the polypeptide. Weight-
based
conservation or homology is based on whether a non-identical corresponding
amino acid
is associated with a positive score on one of the weight-based matrices
described herein
(e.g., BLOSUM50 matrix; PAM250 matrix).
Similar to the above-described functional amino acid classes, naturally
occurring
amino acid residues can be divided into weight-based conservations groups
(which are
divided between "strong" and "weak" conservation groups). The eight commonly
used
weight-based strong conservation groups are Ser Thr Ala, Asn Glu Gln Lys, Asn
His Gln
Lys, Asn Asp Glu Gln, Gln His Arg Lys, Met ile Leu Val, Met Ile Leu Phe, His
Tyr, and
Phe Tyr Trp. Weight-based weak conservation groups include Cys Ser Ala, Ala
Thr Val,
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Ser Ala Gly, Ser Thr Asn Lys, Ser Thr Pro Ala, Ser Gly Asn Asp, Ser Asn Asp
Glu Gln
Lys, Asn Asp Glu Gin His Lys, Asn Glu Gin His Arg Lys, Phe Val Leu Ile Met,
and His
Phe Tyr. Some versions of the CLUSTAL W sequence analysis program provide an
analysis of weight-based strong conservation and weak conservation groups in
the output
of an alignment, thereby offering a convenient technique for determining
weight-based
conservation (e.g., CLUSTAL W provided by the SDSC, which typically is used
with the
SDSC default settings). In some aspects, at least 33%, 50%, 60%, 70%, 80%, or
90% of
the substitutions in such polypeptide variant comprise substitutions wherein a
residue
within a weight-based conservation replaces an amino acid residue of the
polypeptide
sequence that is in the same weight-based conservation group. In other words,
such a
percentage of substitutions are conserved in terms of amino acid residue
weight
characteristics.
The sequence of a polypeptide variant can differ from a mutant CTLA-4
polypeptide of the invention by one or more amino acid substitutions with one
or more
amino acid residues having a similar hydropathy profile (i.e., that exhibit
similar
hydrophilicity) to the substituted (original) residues of the mutant CTLA-4
polypeptide. A
hydropathy profile can be determined using the Kyte & Doolittle index, the
scores for each
naturally occurring amino acid in the index being as follows: I (+4.5). V
(+4.2), L (+3.8),
F (+2.8). C (+2.5), M (+1.9); A (+1.8), G (-0.4), T (-0.7), S (-0.8), W (-
0.9), Y (-1.3), P (-
1.6), H (-3.2); E (-3.5), Q (-3.5), D (-3.5), N (-3.5), K (-3.9), and R (-4.5)
(see, e.g., U.S.
Patent No. 4,554,101 and Kyte & Doolittle, J. Molec. Biol. 157:105-32 (1982)
for further
discussion). At least 75%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97% 98%,
99%,
or 100% of the amino acid residues in the variant polypeptide sequence that
are not
identical to the corresponding residues in the identical or functionally
homologous mutant
CTLA-4 polypeptide sequence disclosed herein ("most related homolog"), which
homolog
may be selected from any of SEQ ID NOS:1-73, exhibit less than a +/-2 change
in
hydrophilicity, including less than a +/-1 change in hydrophilicity and less
than a +/-0.5
change in hydrophilicity with respect to the non-identical amino acid residue
at the
corresponding position in the most related homolog. The variant polypeptide
may exhibit
a total change in hydrophilicity with respect to its most related homolog
selected from the
group of SEQ ID NOS:1-73, of less than about 150, less than about 100, and/or
less than
about 50 (e.g., less than about 30, 20. or 10).
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Examples of typical amino acid substitutions that retain similar or identical
hydrophilicity include arginine-lysine substitutions, glutamate-aspartate
substitutions,
serine-threonine substitutions, glutamine-asparagine substitutions, and valine-
leucine-
isoleucine substitutions. Algorithms and software, such as the GREASE program
available through the SDSC, provide a convenient way for quickly assessing the
hydropathy profile of an amino acid sequence. Because a substantial proportion
(e.g., at
least about 33%), if not most (at least 50%) or nearly all (e.g., about 65,
80, 90, 95, 96, 97,
98, 99%) of the amino acid substitutions in the sequence of a polypeptide
variant often
will have a similar hydropathy score as the amino acid residue that they
replace in the
(reference) polypeptide sequence, the sequence of the polypeptide variant is
expected to
exhibit a similar GREASE program output as the polypeptide sequence. For
example, in a
particular aspect, a polypeptide variant of SEQ ID NO:61 may be expected to
have a
GREASE program (or similar program) output that is more like the GREASE output
obtained by inputting the polypeptide sequence of SEQ ID NO:61 than that
obtained by
using a WT CTLA-4 polypeptide (e.g., hCTLA-4), which can be determined by
visual
inspection or computer-aided comparison of the graphical (e.g., graphical
overlay/alignment) and/or numerical output provided by subjecting the test
variant
sequence and SEQ ID NO:1 to the program.
The conservation of amino acid residues in terms of functional homology,
weight
homology, and hydropathy characteristics, also apply to other polypeptide
sequence
variants provided by the invention, including, but not limited to, e.g.,
polypeptide
sequence variants of a polypeptide sequence selected from the group consisting
of SEQ ID
NOS:1-79197-200, 205-214, and 219-222.
In a particular aspect, the invention includes at least one such polypeptide
variant
comprising an amino acid sequence that differs from a recombinant polypeptide
sequence
selected from the group of SEQ ID NOS:1-79, 197-200, 205-214, and 219-222,
wherein
the amino acid sequence of the variant has at least one such amino acid
residue
substitution selected according to weight-based conservation or homology or
similar
hydropathy profile as discussed above. Such polypeptide variants described
above
typically have an ability to bind CD80 and/or CD86 and/or an ability to
suppress at least
one type of immune response as described above and in greater detail below in
the
Examples.
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Signal Peptide Sequences
Polypeptides of the invention can also further comprise any suitable number
and
type of additional amino acid sequences, such as one or more peptide
fragments. In one
embodiment, such a polypeptide of the invention further comprises a signal
peptide.
Generally, the signal peptide directs the recombinant polypeptide to the
endoplasmic
reticulum when the recombinant polypeptide is expressed in an animal cell. A
signal
sequence that directs organelle trafficking and/or secretion of at least a
portion of the
polypeptide upon expression in a cell may be included. Such sequences are
typically
present in the immature (i.e., not fully processed) form of the polypeptide,
and are
subsequently removed/degraded by cellular proteases to arrive at the mature
form of the
protein. For example, a mutant CTLA-4 polypeptide or fusion protein of the
invention can
include any suitable signal sequence or combinations of signal sequences that
direct the
polypeptide to intracellular compartments, such as a sequence that directs the
polypeptide
to be transported (e.g., translocated) into (e.g., such that the protein is
processed by and
released from) the endoplasmic reticulum or secretory pathway (e.g., the ER,
golgi, and
other secretory related organelles and cellular compartments), the nucleus,
and/or which
directs the polypeptide to be secreted from the cell, translocated in a
cellular membrane, or
target a second cell apart from the cell the protein is secreted from. In this
respect, the
polypeptide can include an intracellular targeting sequence (or "sorting
signal") that
directs the polypeptide to an endosomal and/or lysosomal compartment(s) or
other
compartment rich in MHC II to promote CD4+ and/or CD8+ T cell presentation and
response, such as a lysosomal/ endosomal-targeting sorting signal derived from
lysosomal
associated membrane protein 1 (e.g., LAMP-1 - see, e.g., Wu et al. Proc. Natl.
Acad. Sci.
USA 92:1161-75 (1995) and Ravipraskash et al., Virology 290:74-82 (2001)), a
portion or
homolog thereof (see, e.g., U.S. Patent No. 5,633,234), or other suitable
lysosomal,
endosomal, and/or ER targeting sequence (see, e.g., U.S. Patent No.
6,248,565). In some
aspects, it may desirable for the intracellular targeting sequence to be
located near or
adjacent to a proven /identified epitope sequence(s) within the polypeptide,
which can be
identified by techniques known in the art, thereby increasing the likelihood
of T cell
presentation of polypeptide fragments that comprise such epitope(s). Such
polypeptides
may be expressed from an isolated, recombinant, or synthetic DNA or RNA
delivered to a
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host cell by one or more of the nucleotide transfer vectors, including, e.g.,
one or more of
the gene transfer vectors, described further herein.
The polypeptide may comprise a signal sequence that directs the polypeptide to
the
endoplasmic reticulum (ER) (e.g., facilitates ER translocation of the
polypeptide) when
the polypeptide is expressed in a mammalian cell. The polypeptide can comprise
any
suitable ER-targeting sequence. Many ER-targeting sequences are known in the
art.
Examples of such signal sequences are described in U.S. Patent No. 5,846,540.
Commonly employed ER/secretion signal sequences include the yeast alpha factor
signal
sequence, and mammalian viral signal sequences such as herpes virus gD signal
sequence.
Exemplary signal peptides for E. coli production include the STII or Ipp
signal sequences
of E. coli. Further examples of signal sequences are described in, e.g., U.S.
Patent Nos.
4,690,898, 5,284,768, 5,580,758, 5,652,139, and 5,932,445. Suitable signal
sequences can
be identified using skill known in the art. For example, the SignalP program
(described in,
e.g.. Nielsen et al. (1997) Protein Engineering 10:1-6), which is publicly
available through
the Center for Biological Sequence Analysis at the worldwide website address
designated
cbs.dtu.dk/services/SignalP, or similar sequence analysis software capable of
identifying
signal-sequence-like domains can be used. Related techniques for identifying
suitable
signal peptides are provided in Nielsen et al., Protein Eng. 10(1):1-6 (1997).
Sequences
can be manually analyzed for features commonly associated with signal
sequences, as
described in, e.g., European Patent Application (Appn) No. 0 621 337, Zheng
and
Nicchitta (1999) J. Biol. Chem. 274(51): 36623-30, and Ng et al. (1996) J.
Cell Biol.
134(2):269-78.
Additional Aspects
Any polypeptide of the invention (including any fusion protein of the
invention)
may be present as part of a larger polypeptide sequence, such as occurs upon
the addition
of one or more domains or subsequences for stabilization or detection or
purification of
the polypeptide. Such domains or subsequences may be covalently fused to the
polypeptide of the invention, as one of skill would readily understand and be
able to
construct. A polypeptide purification subsequence may include, e.g., an
epitope tag, a
FLAG tag, a polyhistidine sequence, a GST fusion, or any other
detection/purification
subsequence or "tag" known in the art. These additional domains or
subsequences either
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have little or no effect on the activity of the polypeptide of the invention,
or can be
removed by post synthesis processing steps such as by treatment with a
protease, inclusion
of an intein, or the like.
Any polypeptide of the invention (including any fusion protein of the
invention)
may also comprise one or more modified amino acid. The modified amino acid may
be,
e.g., a glycosylated amino acid, a PEGylated amino acid, a farnesylated amino
acid, an
acetylated amino acid, a biotinylated amino acid, an amino acid conjugated to
a lipid
moiety, and/or an amino acid conjugated to an organic derivatizing agent. The
presence of
modified amino acids may be advantageous in, for example, (a) increasing
polypeptide
serum half-life and/or functional in vivo half-life, (b) reducing polypeptide
antigenicity or
immunogenicity, (c) increasing polypeptide storage stability, (d) increasing
bioavailability,
(e) decreasing effector function, and/or (f) decreasing or inhibiting
undesired self-
association (e.g., aggregate formation) between two or more molecules of the
invention
(such as between two or more fusion protein dimers of the invention). Amino
acid(s) are
modified, for example, co-translationally or post-translationally during
recombinant
production (e.g., N-linked glycosylation at N-X-S/T motifs during expression
in
mammalian cells) or modified by synthetic means.
Polypeptides of the invention (including fusion proteins of the invention)
described
herein can be further modified in a variety of ways by, e.g., post-
translational modification
and/or synthetic modification or variation. For example, polypeptides or
fusion proteins
of the invention may be suitably glycosylated, typically via expression in a
mammalian
cell. For example, in one aspect, the invention provides glycosylated
polypeptides that are
capable of binding CD86 and/or CD80, and/or have an ability to suppress an
immune
response (e.g., T cell proliferation or activation) as described elsewhere
herein, wherein
each said glycosylated polypeptide comprises a polypeptide sequence having at
least 92%,
93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to a sequence selected from
the
group consisting of SEQ ID NOS:1-79, 197-200, 205-214, and 219-222.
The polypeptides of the invention can be subject to any number of additional
forms
suitable of post translational and/or synthetic modification or variation. For
example, the
invention provides protein mimetics of the polypeptides of the invention.
Peptide
mimetics are described in, e.g., U.S. Patent No. 5,668,110 and the references
cited therein.
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In another aspect, a polypeptide or fusion protein of the invention can be
modified
by the addition of protecting groups to the side chains of one or more the
amino acids of
the polypeptide or fusion protein. Such protecting groups can facilitate
transport of the
polypeptide or fusion protein through membrane(s), if desired, or through
certain tissue(s),
for example, by reducing the hydrophilicity and increasing the lipophilicity
of the
polypeptide or fusion protein. Examples of suitable protecting groups include
ester
protecting- groups, amine protecting groups, acyl protecting groups, and
carboxylic acid
protecting groups, which are known in the art (see, e.g., U.S. Patent No.
6,121,236).
Synthetic fusion proteins of the invention can take any suitable form. For
example, the
fusion protein can be structurally modified from its naturally occurring
configuration to
form a cyclic peptide or other structurally modified peptide.
Polypeptides of the invention also can be linked to one or more
nonproteinaceous
polymers, typically a hydrophilic synthetic polymer, e.g., polyethylene glycol
(PEG),
polypropylene glycol, or polyoxyalkylene, using techniques well known in the
art, such as
described in, e.g., U.S. Patent Nos. 4,179,337, 4,301,144, 4,496,689,
4,640,835,
4,670,417, and 4,791,192, or a similar polymer such as polyvinylalcohol or
polyvinylpyrrolidone (PVP).
The invention includes conjugates comprising at least one polypeptide of the
invention (e.g., mutant CTLA-4 ECD polypeptide, dimeric or monomeric mutant
CTLA-
4-12, multimeric mutant CTLA-4 ECD polypeptide, multimeric mutant CTLA-4-Ig)
and a
non-polypeptide moiety. The term "conjugate" (or interchangeably "conjugated
polypeptide") is intended to indicate a heterogeneous (in the sense of
composite or
chimeric) molecule formed by the covalent attachment of one or more
polypeptide(s) to
one or more non-polypeptide moieties. The term "covalent attachment" means
that the
polypeptide and the non-polypeptide moiety are either directly covalently
joined to one
another, or else are indirectly covalently joined to one another through an
intervening
moiety or moieties, such as a bridge, spacer, or linkage moiety or moieties
using an
attachment group present in the polypeptide. Preferably, the conjugate is
soluble at
relevant concentrations and conditions, i.e., soluble in physiological fluids,
such as blood.
Examples of conjugated polypeptides of the invention include glycosylated
and/or
PEGylated polypeptides. The term "non-conjugated polypeptide" may be used
about the
polypeptide part of the conjugate. Such a conjugate typically binds CD80
(e.g., hCD80)
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and/or CD86 (e.g., hCD86) and/or an extracellular domain of either or both
(including
hCD80-Ig and/or hCD86-Ig), and/or has an ability to inhibit an immune
response. Such
an immune response can comprise, but is not limited to, e.g., T cell
activation or
proliferation, cytokine synthesis/production, induction of activation markers,
production of
inflammatory molecules, inflammation, anti-collagen Ab production, and/or T
cell-
dependent Ab response. Exemplary polypeptides include those having at least
95%, 96%,
97%, 98%, 99%, or 100% identity to a sequence selected from the group of SEQ
ID NOS:
1-79, 197-200, 205-214, and 219-222.
The term "non-polypeptide moiety" is intended to indicate a molecule that is
capable of conjugating to an attachment group of a polypeptide of the
invention. Preferred
examples of such molecule include polymer molecules, sugar moieties,
lipophilic
compounds, or organic derivatizing agents. When used in the context of a
conjugate as
described herein it will be understood that the non-polypeptide moiety is
linked to the
polypeptide part of the conjugate through an attachment group of the
polypeptide.
The term "polymer molecule" is defined as a molecule formed by covalent
linkage
of two or more monomers, wherein none of the monomers is an amino acid
residue, except
where the polymer is human albumin or another abundant plasma protein. The
term
"polymer" may be used interchangeably with the term "polymer molecule".
An N-glycosylation site has the sequence N-X-S/T/C, wherein X is any amino
acid
residue except proline, N is asparagine and S/T/C is either serine, threonine
or cysteine,
preferably serine or threonine, and most preferably threonine.
An "0-glycosylation site" comprises the OH-group of a serine or threonine
residue.
The term "attachment group" is intended to indicate an amino acid residue
group
of the polypeptide capable of coupling to the relevant non-polypeptide moiety,
such as a
polymer molecule or a sugar moiety. Non-limiting examples of useful attachment
groups
and some corresponding non-polypeptide moieties are provide in Table 2 below.
35
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Table 2. Useful attachment groups and examples of corresponding non-
polypeptide moieties
Attachment Amino acid Examples of non- Examples of Reference
group polypeptide conjugation
moieties method!
activated PEG
-NH, N-terminus, Lys Polymer, e.g., PEG mPEG-SPA Nektar Inc. 2003
inPEG2-NHS Catalog; see also
mPEG2- Nektar
butyrAL Therapeutics,
2005-06 Catalog
-COOH C-terminus, Asp, Polymer,
e.g., PEG mPEG-Hz Nektar, Inc.
Glu 2003 Catalog;
Sugar moiety /n vitro coupling see also Nektar
Therapeutics
2005-06 Catalog
-SH Cys Polymer, e.g., PEG niPEG-
VS Nektar Inc. 2003
mPEG2-MAL Catalog; Nektar
(mPEG- Therapeutics
maleimide) 2005-2006
Sugar moiety Catalog;
/n vitro coupling Delgado et al.,
Critical Reviews
in Therapeutic
Drug Carrier
Systems
9(3,4):249-304
(1992)
-OH Ser, Thr, OH- Sugar moiety /n vivo 0-linked
glycosylation
-CONH2 Asn as part of an Sugar moiety In
vivo N-
N-glycosylation glycosylation
site
Aromatic Phe, Tyr, Trp Sugar moiety In vitro coupling
residue
-CONN, Gin Sugar moiety in vitro coupling Yan
and Wold,
Biochemistry,
1984, Jul 31;
23(16): 3759-65
Aldehyde Oxidized Polymer, e.g., PEGylation Andresz et al.,
Ketone carbohydrate PEG, 1978, Makromol.
PEG-hydrazide Chem. 179:301;
WO 92/16555,
WO 00/23114
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Attachment Amino acid Examples of non- Examples of
Reference
group polypeptide conjugation
moieties method /
activated PEG
Guanidino Arg Sugar moiety In vitro coupling Lundblad and
Noyes, Chemical
Reagents for
Protein
Modification,
CRC Press Inc.
Boca Raton, FI
Imidazole ring His Sugar moiety In vitro coupling As for
guanidine
For in vivo N-glycosylation, the term "attachment group" is used in an
unconventional way to indicate the amino acid residues constituting an N-
glycosylation
site (with the sequence N-X-S/T/C, wherein X is any amino acid residue except
proline, N
is asparagine and S/T/C is either serine, threonine or cysteine, preferably
serine or
threonine, and most preferably threonine). Although the asparagine residue of
the N-
glycosylation site is the one to which the sugar moiety is attached during
glycosylation,
such attachment cannot be achieved unless the other amino acid residues of the
N-
glycosylation site is present. Accordingly, when the non-polypeptide moiety is
a sugar
moiety and the conjugation is to be achieved by N-glycosylation, the term
"amino acid
residue comprising an attachment group for the non-polypeptide moiety" as used
in
connection with alterations of the amino acid sequence of the polypeptide of
the invention
is to be understood as one, two or all of the amino acid residues constituting
an N-
glycosylation site is/are to be altered in such a manner that either a
functional N-
glycosylation site is introduced into the amino acid sequence, removed from
said sequence
or a functional N-glycosylation site is retained in the amino acid sequence
(e.g., by
substituting a serine residue, which already constitutes part of an N-
glycosylation site,
with a threonine residue and vice versa).
The term "introduce" (i.e., an "introduced" amino acid residue, "introduction"
of
an amino acid residue) is primarily intended to mean substitution of an
existing amino acid
residue for another amino acid residue, but may also mean insertion of an
additional amino
acid residue.
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The term "remove" (i.e., a "removed" amino acid residue, "removal" of an amino
acid residue) is primarily intended to mean substitution of the amino acid
residue to be
removed for another amino acid residue, but may also mean deletion (without
substitution)
of the amino acid residue to be removed.
The term "amino acid residue comprising an attachment group for the non-
polypeptide moiety" is intended to indicate that the amino acid residue is one
to which the
non-polypeptide moiety binds (in the case of an introduced amino acid residue)
or would
have bound (in the case of a removed amino acid residue).
By removing and/or introducing amino acid residues comprising an attachment
group for the non-polypeptide moiety it is possible to specifically adapt the
polypeptide of
the invention so as to make the molecule more susceptible to conjugation to
the non-
polypeptide moiety of choice, to optimize the conjugation pattern (e.g., to
ensure an
optimal distribution of non-polypeptide moieties on the surface of the
polypeptide and
thereby, e.g., effectively shield epitopes and other surface parts of the
polypeptide without
significantly impairing the function thereof). For instance, by introduction
of attachment
groups, the polypeptide is altered in the content of the specific amino acid
residues to
which the relevant non-polypeptide moiety binds, whereby a more efficient,
specific
and/or extensive conjugation is achieved. By removal of one or more attachment
groups it
is possible to avoid conjugation to the non-polypeptide moiety in parts of the
polypeptide
in which such conjugation is disadvantageous, e.g., to an amino acid residue
located at or
near a functional site of the polypeptide (since conjugation at such a site
may result in
inactivation or reduced CD80- or CD86-binding or reduced immunosuppressive
activity of
the resulting conjugate). Further, it may be advantageous to remove an
attachment group
located close to another attachment group.
The amino acid residue comprising an attachment group for a non-polypeptide
moiety, whether an existing residue or a removed or introduced residue, is
selected on the
basis of the nature of the non-polypeptide moiety and, in some instances, on
the basis of
the conjugation method to be used. For instance, when the non-polypeptide
moiety is a
polymer molecule, such as a polyethylene glycol (PEG) or polyalkylene oxide
(POA)
derived molecule, amino acid residues capable of functioning as an attachment
group may
be selected from the group consisting of cysteine, lysine (and/or the N-
terminal amino
group of the polypeptide), aspartic acid, glutamic acid, histidine and
arginine. When the
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non-polypeptide moiety is a sugar moiety, the attachment group is an in vivo
or in vitro N-
or 0-glycosylation site, preferably an N-glycosylation site.
In some instances, in the mutant CTLA-4 polypeptide part of a conjugate of the
invention, attachment groups located at or near the receptor binding sites are
removed,
such as by substitution of the amino acid residue comprising such group. In
some
instances, amino acid residues comprising an attachment group for a non-
polypeptide
moiety, such as cysteine or lysine, are often not introduced at or near the
receptor binding
site of the mutant CTLA-4 polypeptide.
A mutant CTLA-4 polypeptide of the invention can be modified so as to shield
and
thereby modify or destroy or otherwise inactivate an epitope present in the
mutant CTLA-
4 polypeptide, by conjugation to a non-polypeptide moiety. Epitopes of mutant
CTLA-4
polypeptides may be identified by use of methods known in the art, also known
as epitope
mapping, see e.g., Romagnoli et al., J. Biol. Chem. 380(5):553-9 (1999),
DeLisser HM,
Methods Mol Biol, 1999, 96:11-20, Van de Water et al., Clin. Imrnunol.
Immunopathol.
85(3):229-35 (1997), Saint-Remy JM, Toxicology 119(1):77-81 (1997).
The exact number of attachment groups available for conjugation and present in
the mutant CTLA-4 polypeptide is dependent on the effect desired to be
achieved by
conjugation. The effect to be obtained is, e.g., dependent on the nature and
degree of
conjugation (e.g., the identity of the non-polypeptide moiety, the number of
non-
polypeptide moieties desirable or possible to conjugate to the polypeptide,
where they
should be conjugated or where conjugation should be avoided, etc.). For
instance, if
reduced immunogenicity is desired, the number (and location of) attachment
groups
should be sufficient to shield most or all epitopes. This is normally obtained
when a
greater proportion of the mutant CTLA-4 polypeptide is shielded. Effective
shielding of
epitopes is normally achieved when the total number of attachment groups
available for
conjugation is in the range of 1-6 attachment groups, e.g., 1-5, such as in
the range of 1-3,
such as 1, 2, or 3 attachment groups.
Functional in vivo half-life can be dependent on the molecular weight of the
conjugate, and the number of attachment groups needed for providing increased
half-life
thus depends on the molecular weight of the non-polypeptide moiety in
question. Some
such conjugates comprise 1-6, e.g., 1-5, such as 1-3, e.g., 1, 2, or 3 non-
polypeptide
moieties each having a molecular weight of about 100-2000 Daltons (Da), such
as about
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200 Da, about 300 Da, about 400 Da. about 600 Da. about 900 Da, about 1000 Da,
or
about 2-40 kDa, such as about 2 kDa, about 5 kDa. about 12 kDa, about 15 kDa,
about 20
kDa, about 30 kDa, about 40 kDa, or about 60 kDa.
In the conjugate of the invention, some, most, or substantially all
conjugatable
attachment groups are occupied by the relevant non-polypeptide moiety.
The conjugate of the invention may exhibit one or more of the following
improved
properties: (a) increased serum half-life and/or functional in vivo half-life,
(b) reduced
antigenicity or immunogenicity, (c) increased storage stability, (d) increased
bioavailability, (e) decreased effector function, or (f) decreased or
inhibited self-
association (e.g., decreased aggregate formation) between two or more
molecules of the
invention. For example, the conjugate may exhibit a reduced immunogenicity as
compared to hCTLA-4 or as compared to the corresponding non-conjugated
polypeptide,
e.g., a reduction of at least 10%, such as a reduction of at least of 25%,
such as a reduction
of at least of 50%, e.g., a reduction of at least 75% compared to the non-
conjugated
polypeptide or compared to a hCTLA-4. The conjugate may exhibit an increased
functional in vivo half-life and/or increased serum half-life as compared to a
reference
molecule, such as hCTLA-4 or as compared to the corresponding non-conjugated
polypeptide. Particular preferred conjugates are such conjugates where the
ratio between
the functional in vivo half-life (or serum half-life) of said conjugate and
the functional in
vivo half-life (or serum half-life) of said reference molecule is at least
1.25, such as at least
1.50, such as at least 1.75, such as at least 2, such as at least 3, such as
at least 4, such as at
least 5, such as at least 6, such as at least 7, such as at least 8. The half-
life is conveniently
determined in an experimental animal, such as rat or monkey, and may be based
on
intravenously or subcutaneously administration. In a further aspect, the
conjugate may
exhibit an increased bioavailability as compared to a reference molecule such
as an
hCTLA-4 or a corresponding non-conjugated polypeptide.
The polymer molecule to be coupled to the polypeptide may be any suitable
polymer
molecule, such as a natural or synthetic homopolymer or heteropolymer,
typically with a
molecular weight in the range of 300-100,000 Da, such as 300-20,000 Da, more
preferably in
the range of 500-10,000 Da, even more preferably in the range of 500-5000 Da.
Examples of homopolymers include a polyol (i.e. poly-OH), a polyamine (i.e.
poly-
NH2) and a polycarboxylic acid (i.e. poly-COOH). A heteropolymer is a polymer.
which
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comprises one or more different coupling groups, such as, e.g., a hydroxyl
group and an
amine group. Examples of suitable polymer molecules include polymer molecules
selected
from the group consisting of polyalkylene oxide (PAO), including polyalkylene
glycol
(PAG), such as polyethylene glycol (PEG) and polypropylene glycol (PPG),
branched PEGs,
poly-vinyl alcohol (PVA), poly-carboxylate, poly-(vinylpyrolidone),
polyethylene-co-maleic
acid anhydride, polystyrene-co-malic acid anhydride, dextran including
carboxymethyl-
dextran, or any other biopolymer suitable for reducing immunogenicity and/or
increasing
functional in vivo half-life and/or serum half-life. Another example of a
polymer molecule is
human albumin or another abundant plasma protein. Generally, polyalkylene
glycol-derived
polymers are biocompatible, non-toxic, non-antigenic, non-immunogenic, have
various
water solubility properties, and are easily excreted from living organisms.
PEG is the prefeiTed polymer molecule to be used, since it has only few
reactive
groups capable of cross-linking compared, e.g., to polysaccharides such as
dextran, and the
like. In particular, monofunctional PEG, e.g., monomethoxypolyethylene glycol
(mPEG), is
of interest since its coupling chemistry is relatively simple (only one
reactive group is
available for conjugating with attachment groups on the polypeptide).
Consequently, the risk
of cross-linking is eliminated, the resulting polypeptide conjugates are more
homogeneous
and the reaction of the polymer molecules with the polypeptide is easier to
control. When
the molecule is PEGylated, it usually comprises 1, 2, 3, 4, or 5 polyethylene
glycol (PEG)
molecules. Each PEG molecule can have a molecular weight of about 5 kDa (kilo
Dalton)
to 100 kDa, including, e.g., about 10 kDa, about 12 kDa, about 20 kDa, about
40 kDa.
Suitable PEG molecules are available from Shearwater Polymers, Inc. and Enzon,
Inc. and
may be selected from SS-PEG, NPC-PEG, aldehyde-PEG, mPEG-SPA, mPEG-SCM,
mPEG-BTC, SC-PEG, tresylated mPEG (US 5,880,255), or oxycarbonyl-oxy-N-
dicarboxyimide-PEG (US 5,122,614).
In one aspect, the invention provides an isolated or synthetic conjugate
comprising:
(a) a polypeptide of the invention (e.g., mutant CTLA-4 ECD polypeptide,
dimeric or
monomeric mutant CTLA-4-Ig, multimeric mutant CTLA-4 ECD polypeptide,
multimeric
mutant CTLA-4-Ig); and (b) at least one non-polypeptide moiety, such as, e.g.,
1-10, 1-9,
1-8, 1-7, 1-7, 1-6, 1-5, 1-4, 1-3, 1, 2, or 3 non-polypeptide moieties
attached to the
polypeptide, wherein the conjugate binds CD80 (e.g., hCD80) and/or CD86 (e.g.,
hCD86)
and/or an extracellular domain of either or both (including hCD80-Ig and/or
hCD86-Ig),
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and/or has an ability to induce an immune response (e.g., T cell-dependent
immune
response). Exemplary polypeptides include those having at least 92%, 93%, 94%,
95%,
96%, 97%, 98%, 99%, or 100% identity to a polypeptide sequence selected from
the group
of SEQ ID NOS: 1-79, 197-200, 205-214, and 219-222. In some instances, the
conjugate
comprises one non-polypeptide moiety. In some instances, the conjugate
comprises two,
three, four or more non-polypeptide moieties. In some instances, the amino
acid sequence
of the polypeptide of the conjugate further comprises one or more
substitutions which each
introduce an attachment group for the non-polypeptide moiety (e.g., by
substitution of an
amino acid residue of the polypeptide sequence with a different residue which
comprises
an attachment group for the non-polypeptide moiety, or by insertion into the
polypeptide
sequence of an additional amino acid residue which comprises an attachment
group for the
non-polypeptide moiety).
A conjugate can comprise two or more polypeptides of the invention. In some
instances, a non-polypeptide moiety is covalently attached to either or both
such
polypeptides. If the conjugate comprises two or more identical polypeptides of
the
invention, the same type and number of non-polypeptide moieties are typically
attached to
each such polypeptide, usually in the same manner to the corresponding
attachment
group(s) on each polypeptide. As noted above, the non-polypeptide moiety can
comprise,
e.g., a sugar molecule, which optionally can be attached to an N-
,glycosylation site, or a
polymer, such as, e.g., a polyethylene glycol moiety. The polyethylene glycol
moiety can
be covalently attached to a cysteine residue or lysine residue of the
polypeptide of the
invention. In some instances, the polyethylene glycol moiety is covalently
attached to the
N-terminal amino group of the polypeptide. A conjugate comprising a mutant
CTLA-4-Ig
of the invention may be described as a mutant CTLA-4-Ig conjugate of the
invention.
Multimers of conjugates are also included. Multimeric conjugates include two
or more
conjugates, wherein at least one conjugate is a conjugate of the invention
comprising at
least one polypeptide of the invention. The conjugates in a multimeric
conjugate can be,
but need not be, identical to one another.
As discussed above, polypeptides of the invention, including fusion proteins
of the
invention, can commonly be subject to glycosylation. Polypeptides and fusion
proteins of
the invention can further be subject to (or modified such that they are
subjected to) other
forms of post-translational modification including, e.g., hydroxylation, lipid
or lipid
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derivative-attachment, methylation, myristylation, pegylation,
phosphorylation, and
sulfation. Other post-translational modifications that a polypeptide or fusion
protein of the
invention can be rendered subject to include acetylation, acylation, ADP-
ribosylation,
arnidation, covalent attachment of flavin, covalent attachment of a heme
moiety, covalent
attachment of a nucleotide or nucleotide derivative, covalent attachment of
phosphotidylinositol, cross-linking, cyclization, disulfide bond formation,
demethylation,
formylation, GPI anchor formation, iodination, oxidation, proteolytic
processing,
prenylation, racemization, selenoylation, arginylation, and ubiquitination.
Other common
protein modifications are described in, e.g., Creighton, supra, Seifter et
al., Meth.
Enzymol. 18:626-646 (1990), and Rattan et al., Ann. NY Acad. Sci. 663:48-62
(1992).
Post-translational modifications for polypeptides or fusion proteins expressed
from nucleic
acids in host cells vary depending what kind of host or host cell type the
peptide is
expressed in. For instance, glycosylation often does not occur in bacterial
hosts such as E.
coli and varies considerably in baculovirus systems as compared to mammalian
cell
systems. Accordingly, when glycosylation is desired (which usually is the case
for most
polypeptides of the present invention), a polypeptide or fusion protein should
be expressed
(produced) in a glycosylating host, generally a eukaryotic cell (e.g., a
mammalian cell or
an insect cell). Modifications to the polypeptide or fusion protein in terms
of post-
translational modification can be verified by any suitable technique,
including, e.g., x-ray
diffraction, NMR imaging, mass spectrometry, and/or chromatography (e.g.,
reverse phase
chromatography, affinity chromatography, or GLC).
The polypeptide or fusion protein also or alternatively can comprise any
suitable
number of non-naturally occurring amino acids (e.g., 13 amino acids) and/or
alternative
amino acids (e.g., selenocysteine), or amino acid analogs, such as those
listed in the
MANUAL OF PATENT EXAMINING PROCEDURE 2422 (7th Revision ¨ 2000), which can
be
incorporated by protein synthesis, such as through solid phase protein
synthesis (as
described in, e.g., Merrifield, Adv. Enzymol. 32:221-296 (1969) and other
references cited
herein). A polypeptide or fusion protein of the invention can further be
modified by the
inclusion of at least one modified amino acid. The inclusion of one or more
modified
amino acids may be advantageous in, for example, (a) increasing polypeptide or
fusion
protein serum half-life, (b) reducing polypeptide or fusion protein
antigenicity, or (c)
increasing polypeptide or fusion protein storage stability. Amino acid(s) are
modified, for
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example, co-translationally or post-translationally during recombinant
production (e.g., N-
linked glycosylation site at N-X-S/T motifs during expression in mammalian
cells) or
modified by synthetic means. Non-limiting examples of a modified amino acid
include a
glycosylated amino acid, a sulfated amino acid, a prenylated (e.g.,
famesylated,
geranylgeranylated) amino acid, an acetylated amino acid, an acylated amino
acid, a
PEGylated amino acid, a biotinylated amino acid, a carboxylated amino acid, a
phosphorylated amino acid, and the like. References adequate to guide one of
skill in the
modification of amino acids are replete throughout the literature. Example
protocols are
found in Walker (1998) Protein Protocols on CD-ROM Humana Press, Towata, NJ.
The
modified amino acid may be selected from a glycosylated amino acid, a
PEGylated amino
acid, a farnesylated amino acid, an acetylated amino acid, a biotinylated
amino acid, an
amino acid conjugated to a lipid moiety, and an amino acid conjugated to an
organic
derivatizing agent.
The invention further provides polypeptides (including fusion proteins) having
the
above-described characteristics that further comprise additional amino acid
sequences that
impact the biological function (e.g., immunogenicity, targeting, and/or half-
life) of the
polypeptide (or fusion protein).
A polypeptide or fusion protein of the invention may further include a
targeting
sequence other than, or in addition to, a signal sequence. For example, the
polypeptide or
fusion protein can comprise a sequence that targets a receptor on a particular
cell type
(e.g., a monocyte, dendritic cell, or associated cell) to provide targeted
delivery of the
polypeptide to such cells and/or related tissues. Signal sequences are
described above, and
include membrane localization/anchor sequences (e.g., stop transfer sequences,
GPI
anchor sequences), and the like.
A particularly useful fusion partner for a polypeptide of the invention
(including a
fusion protein of the invention) is a peptide sequence that facilitates
purification of the
polypeptide, e.g., a polypeptide purification subsequence. A polynucleotide of
the
invention may comprise a coding sequence fused in-frame to a marker amino acid
sequence that, e.g., facilitates purification of the encoded polypeptide. Such
purification
facilitating peptide domains or polypeptide purification subsequences include,
but are not
limited to, metal chelating peptides, such as histidine-tryptophan modules
that allow
purification on immobilized metals, such as a hexa-histidine peptide or other
a
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polyhistidine sequence, a sequence encoding such a tag is incorporated in the
pQE vector
available from QIAGEN, Inc. (Chatsworth, California), a sequence which binds
glutathione (e.g., glutathione-S-transferase (GST)), a hemagglutinin (HA) tag
(corresponding to an epitope derived from the influenza hemagglutinin protein;
Wilson et
al., Cell 37:767 (1984)), maltose binding protein sequences, the FLAG epitope
utilized in
the FLAGS extension/affinity purification system (Immunex Corp, Seattle,
WA)(commercially available FLAG epitopes also are available through Kodak (New
Haven, Connecticut)), an E-epitope tag (E-tag), thioredoxin (TRX), avidin, and
the like.
Purification-facilitating epitope tags have been described in the art (see,
e.g., Whitehorn et
al., Biotechnology 13:1215-19 (1995)). A polypeptide can include an e-his tag,
which
may comprise a polyhistidine sequence and an anti-e-epitope sequence
(Pharmacia
Biotech Catalog); e-his tags can be made by standard techniques. The inclusion
of a
protease-cleavable polypeptide linker sequence between the purification domain
and the
polypeptide is useful to facilitate purification. The histidine residues
facilitate purification
on EVIIAC (immobilized metal ion affinity chromatography (IIVIAC), as
described in
Porath et al. Protein Expression and Purification 3:263-281(1992)), while the
enterokinase
cleavage site provides a method for separating the polypeptide from the fusion
protein.
pGEX vectors (Promega; Madison, WI) can also be used to express foreign
polypeptides
as fusion proteins with glutathione S-transferase (GST). In general, such
fusion proteins
are soluble and can easily be purified from lysed cells by adsorption to
ligand-agarose
beads (e.g., glutathione-agarose in the case of GST-fusion) followed by
elution in the
presence of free ligand. Additional examples of polypeptide purification
facilitating
subsequences and the use thereof for protein purification are described in,
e.g., Int'l Patent
Appn Publ. No. WO 00/15823. After expression of the polypeptide of interest
and
isolation thereof by such fusion partners or otherwise as described above,
protein refolding
steps can be used, as desired, in completing configuration of the mature
polypeptide.
A fusion protein of the invention also can include one or more additional
peptide
fragments or peptide portions which promote detection of the fusion protein.
For example,
a reporter peptide fragment or portion (e.g., green fluorescent protein (GFP),
p-
galactosidase, or a detectable domain thereof) can be incorporated in the
fusion protein.
Additional marker molecules that can be conjugated to the polypeptide of the
invention
include radionuclides, enzymes, fluorophores, small molecule ligands, and the
like. Such
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detection-promoting fusion partners are particularly useful in fusion proteins
used in
diagnostic techniques discussed elsewhere herein.
In another aspect, a polypeptide of the invention can comprise a fusion
partner that
promotes stability of the polypeptide, secretion of the polypeptide (other
than by signal
targeting), or both. For example, the polypeptide can comprise an
immunoglobulin (Ig)
domain, such as an IgG polypeptide comprising an Fc hinge region, a CH2
domain, and a
CH3 domain, that promotes stability and/or secretion of the polypeptide.
The fusion protein peptide fragments or peptide portions can be associated in
any
suitable manner. The various polypeptide fragments or portions of the fusion
protein may
be covalently associated (e.g., by means of a peptide or disulfide bond). The
polypeptide
fragments or portions can be directly fused (e.g., the C-terminus of an
antigenic or
immunogenic sequence of the invention can be fused to the N-terminus of a
purification
sequence or heterologous immunogenic sequence). The fusion protein can include
any
suitable number of modified bonds, e.g., isosteres, within or between the
peptide portions.
Alternatively or additionally, the fusion protein can include a peptide linker
between one
or more polypeptide fragments or portions that includes one or more amino acid
sequences
not forming part of the biologically active peptide portions. Any suitable
peptide linker
can be used. Such a linker can be any suitable size. Typically, the linker is
less than about
30 amino acid residues, less than about 20 amino acid residues, and/or less
than 10 amino
acid residues. The linker predominantly may comprise or consist of neutral
amino acid
residues. Suitable linkers are generally described in, e.g., U.S. Patent Nos.
5,990,275,
6,010,883, 6,197,946, and European Patent Application 0 035 384. If separation
of
peptide fragments or peptide portions is desirable a linker that facilitates
separation can be
used. An example of such a linker is described in U.S. Patent No. 4,719,326.
"Flexible"
linkers, which are typically composed of combinations of glycine and/or serine
residues,
can be advantageous. Examples of such linkers are described in, e.g.,
McCafferty et al.,
Nature 348:552-554 (1990), Huston et al., Proc. Natl. Acad. Sci. USA 85:5879-
5883
(1988), Glockshuber et al., Biochemistry 29:1362-1367 (1990), and Cheadle et
al.,
Molecular Immunol. 29:21-30 (1992), Bird et al., Science 242:423-26 (1988),
and U.S.
Patent Nos. 5,672,683, 6,165,476, and 6,132,992.
The use of a linker also can reduce undesired immune response to the fusion
protein created by the fusion of the two peptide fragments or peptide
portions, which can
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result in an unintended MI-IC I and/or MHC II epitope being present in the
fusion protein.
In addition to the use of a linker, identified undesirable epitope sequences
or adjacent
sequences can be PEGylated (e.g., by insertion of lysine residues to promote
PEG
attachment) to shield identified epitopes from exposure. Other techniques for
reducing
immunogenicity of the fusion protein of the invention can be used in
association with the
administration of the fusion protein include the techniques provided in U.S.
Patent No.
6,093,699.
Making Polypeptides
Recombinant methods for producing and isolating polypeptides of the invention
(including fusion proteins of the invention) are described below. In addition
to
recombinant production, the polypeptides may be produced by direct peptide
synthesis
using solid-phase techniques (see, e.g., Stewart et al. (1969) Solid-Phase
Peptide
Synthesis, W.H. Freeman Co, San Francisco; Merrifield (1963) J. Am. Chem. Soc
85:2149-2154). Peptide synthesis may be performed using manual techniques or
by
automation. Automated synthesis may be achieved, for example, using Applied
Biosystems 431A Peptide Synthesizer (Perkin Elmer, Foster City, Calif.) in
accordance
with the instructions provided by the manufacturer. For example, subsequences
may be
chemically synthesized separately and combined using chemical methods to
provide
mutant CTLA-4 polypeptides or functional fragments thereof. Alternatively,
such
sequences may be ordered from any number of companies that specialize in
production of
polypeptides. Most commonly, polypeptides of the invention are produced by
expressing
coding nucleic acids and recovering polypeptides, e.g., as described below.
The invention provides methods for producing polypeptides (including fusion
proteins) of the invention. One such method comprises introducing into a
population of
cells any nucleic acid described herein, which is operatively linked to a
regulatory
sequence effective to produce the encoded polypeptide, culturing the cells in
a culture
medium to produce the polypeptide, and isolating the polypeptide from the
cells or from
the culture medium. An amount of nucleic acid sufficient to facilitate uptake
by the cells
(transfection) and/or expression of the polypeptide is utilized. The culture
medium can be
any described herein and in the Examples. Additional media are known to those
of skill in
the art. The nucleic acid is introduced into such cells by any delivery method
described
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herein, including, e.g., injection, needleless injection device, gene gun,
electroporation
(e.g., DNA electroporation device, Inovio Biomedical Corp. (San Diego)),
transdermal
delivery, passive uptake, etc. The nucleic acid of the invention may be part
of a vector,
such as a recombinant expression vector, including a DNA plasmid vector, viral
vector, or
any vector described herein. The nucleic acid or vector comprising a nucleic
acid of the
invention may be prepared and formulated as described herein, above, and in
the
Examples below. Such a nucleic acid or expression vector may be introduced
into a
population of cells of a mammal in vivo, or selected cells of the mammal
(e.g., tumor
cells) may be removed from the mammal and the nucleic acid expression vector
introduced ex vivo into the population of such cells in an amount sufficient
such that
uptake and expression of the encoded polypeptide results. Or, a nucleic acid
or vector
comprising a nucleic acid of the invention is produced using cultured cells in
vitro. In one
aspect, the method of producing a polypeptide of the invention comprises
introducing into
a population of cells a recombinant expression vector comprising any nucleic
acid
described herein in an amount and formula such that uptake of the vector and
expression
of the polypeptide will result; administering the expression vector into a
mammal by any
introduction/delivery format described herein; and isolating the polypeptide
from the
mammal or from a byproduct of the mammal. Suitable host cells, expression
vectors,
methods for transfecting host cells with an expression vector comprising a
nucleic acid
sequence encoding a polypeptide of the invention, cell cultures, and
procedures for
producing and recovering such polypeptide from a cell culture are described in
detail
below in the section entitled "Nucleic Acids of the Invention." Additional
methods of
production are discussed in the Examples, infra.
As noted above, polypeptides of the invention (which includes fusion proteins
of
the invention) can be subject to various changes, such as one or more amino
acid or
nucleic acid insertions, deletions, and substitutions, either conservative or
non-
conservative, including where, e.g., such changes might provide for certain
advantages in
their use, e.g., in their therapeutic or prophylactic use or administration or
diagnostic
application. Procedures for making variants of polypeptides by using amino
acid
substitutions, deletions, insertions, and additions are routine in the art.
Polypeptides and
variants thereof having the desired ability to bind CD80 and/or CD86, or a
fragment
thereof (e.g., ECD) or an ability to suppress an immune response in vitro or
in vivo as
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described in detail elsewhere herein are readily identified by assays known to
those of skill
in the art and by the assays described herein. See, e.g., assays presented in
the Examples
below.
The nucleic acids of the invention, discussed in greater detail infra, can
also be
subject to various changes, such as one or more substitutions of one or more
nucleic acids
in one or more codons such that a particular codon encodes the same or a
different amino
acid, resulting in either a conservative or non-conservative substitution, or
one or more
deletions of one or more nucleic acids in the sequence. The nucleic acids can
also be
modified to include one or more codons that provide for optimum expression in
an
expression system (e.g., mammalian cell or mammalian expression system),
while, if
desired, said one or more codons still encode the same amino acid(s).
Procedures for
making variants of nucleic acids by using nucleic acid substitutions,
deletions, insertions,
and additions, and degenerate codons, are routine in the art, and nucleic acid
variants
encoding polypeptides having the desired properties described herein (e.g., an
ability to
bind CD80 and/or CD86, and/or suppress an immune response in vitro or in vivo)
are
readily identified using the assays described herein. Such nucleic acid
changes might
provide for certain advantages in their therapeutic or prophylactic use or
administration, or
diagnostic application. In one aspect, the nucleic acids and polypeptides can
be modified
in a number of ways so long as they comprise a nucleic acid or polypeptide
sequence
substantially identical to the nucleic acid sequence of a respective mutant
CTLA-4
polypeptide-encoding nucleic acid or mutant CTLA-4 polypeptide of the
invention,
respectively.
NUCLEIC ACIDS OF THE INVENTION
The invention provides isolated or recombinant nucleic acids (also referred to
herein as polynucleotides), collectively referred to as "nucleic acids of the
invention" (or
"polynucleotides of the invention"), which encode polypeptides of the
invention. Nucleic
acids of the invention, including all described below, are useful in
recombinant production
(e.g., expression) of polypeptides of the invention, typically through
expression of a
plasmid expression vector comprising a sequence encoding the polypeptide or
fragment
thereof; as therapeutics; as prophylactics; as diagnostic tools; as diagnostic
probes for the
presence of complementary or partially complementary nucleic acids (including
for
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detection of a wild-type CTLA-4 nucleic acid). For example, nucleic acids of
the
invention, including all described below, are useful because they encode
polypeptides that
are useful in suppressing or inhibiting an immune response (e.g., T cell
activation, T cell
proliferation, cytokine synthesis or production (e.g., production of TNF-a,
IFN-7, IL-2),
induction of activation markers (e.g., CD25, IL-2 receptor), inflammation,
anti-collagen
antibody production, and/or T cell-dependent antibody response) in vitro
and/or in vivo
applications, including, e.g., prophylactic and/or therapeutic methods for
treating immune
system diseases, disorders, and conditions in which suppression of an immune
response is
desirable (e.g., methods for treating autoimmune diseases and disorders and
methods for
inhibiting rejection of a tissue, cell, or organ transplant from a donor by a
recipient).
Nucleic acids of the invention can also be incorporated into expression
vectors useful for
gene therapy, DNA vaccination, and immunosuppressive therapy. Additional uses
of the
nucleic acids and vectors of the invention comprising such nucleic acids are
described
elsewhere herein.
In one aspect, the invention provides an isolated or recombinant nucleic acid
comprising a nucleotide sequence encoding any polypeptide (including any
fusion protein,
etc.) of the invention described above in the section entitled "Polypeptides
of the
Invention" and elsewhere herein. The invention also provides an isolated or
recombinant
nucleic acid comprising a nucleotide sequence encoding a combination of two or
more of
any polypeptides (including any fusion proteins) of the invention described
above and
elsewhere herein. Also included is a nucleic acid that encodes any polypeptide
of the
invention, such as, e.g., a mutant CTLA-4 ECD polypeptide or mutant CTLA-4-Ig
fusion
protein, which comprises a sequence of codons substantially optimized for
expression in a
mammalian host, such as a human.
For example, in one aspect, the invention provides an isolated or recombinant
nucleic acid comprising a polynucleotide sequence that encodes a polypeptide
comprising
a polypeptide sequence that has at least 75%, 80%, 85%, 86%, 87%, 88%, 89%,
90%,
91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 100% sequence identity
to
at least one polypeptide sequence selected from the group consisting of SEQ ID
NOS:1-
73, or a complementary polynucleotide sequence thereof, wherein the
polypeptide binds
CD80 and/or CD86 or a polypeptide fragment of CD80 and/or CD86 (e.g., an
extracellular
domain of CD80 and/or CD86), and/or suppress an immune response in vitro
and/or in
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vivo, or a complementary polynucleotide sequence thereof. Additional details
regarding
the functional properties and characteristics of such polypeptides are
discussed above in
"Polypeptides of the Invention." Some such nucleic acids encode a polypeptide
comprising a polypeptide sequence having an amino acid length about equal to
the amino
acid length of the hCTLA-4 ECD; as, e.g., 110-138, 112-132, 118-130,119-129,
120-128,
121-127, 122-126, 123-125, or 124 amino acid residues. Exemplary nucleic acids
which
encode the mutant CTLA-4 ECD polypeptides comprising the sequences set forth
in SEQ
BD NOS:1-73, but are not limited to, e.g., nucleic acids having nucleotide
sequences set
forth in SEQ ID NOS:80-152, respectively. For example, an exemplary nucleic
acid
encoding the polypeptide shown in SEQ ID NO:1 (clone D3-1) is the nucleic acid
shown
in SEQ ID:80. Also included are fragments of any such nucleic acids, wherein
such
fragment encodes a polypeptide that binds CD80 and/or CD86 and/or an ECD of
either or
both, and/or has an ability to suppress an immune response.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide (e.g., mutant
CTLA-4
ECD polypeptide) which comprises a polypeptide sequence (a) which differs from
a
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73 in
no more
than 6 amino acid residues (e.g., no more than 1, 2, 3, 4, 5, or 6 amino acid
residues), and
(b) wherein the amino acid residue in the polypeptide sequence at position 41,
50, 54, 55,
56, 64, 65, 70, or 85 is identical to the amino acid residue at the
corresponding position of
said polypeptide sequence selected from the group consisting of SEQ ID NOS:1-
73,
wherein the polypeptide binds CD80 and/or CD86 and/or an extracellular domain
of either
or both, and/or inhibits an immune response in vitro and/or in vivo, or a
complementary
polynucleotide sequence thereof. That is, the amino acid residue at such
position 41, 50,
54, 55, 56, 64, 65, 70, or 85 in such selected polypeptide sequence is not
deleted or
substituted. Some such nucleic acids encode polypeptides comprising a sequence
which
differs from the selected polypeptide sequence by no more than 6 amino acid
residues and
which includes amino acid residues at 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
and/or 14
positions selected from amino acid positions 24, 30, 32, 41, 50, 54, 55, 56,
64, 65, 70, 85,
104 and 106 that are identical to the amino acid residues at the corresponding
positions in
the selected polypeptide sequence. Such polypeptides can differ from the
selected
polypeptide sequence by amino acid deletion(s), addition(s), and/or amino acid
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substitution(s). An amino acid substitution may be a conservative or non-
conservative
substitution. Exemplary conservative substitutions are discussed in the
section entitled
-Sequence Variation." Some such polypeptides comprise a sequence having a
length of
about 118-130, 119-129, 120-128, 121- 127, 122-126, 123-125, or 124 amino acid
residues. Additional details of the functional properties and characteristics
of such
polypeptides are discussed above. Exemplary nucleic acids include, but are not
limited to,
e.g., those comprising nucleotide sequences set forth in SEQ ID NOS:80-152.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide (e.g., mutant
CTLA-4
ECD) comprising a polypeptide sequence which (a) differs from the polypeptide
sequence
of the extracellular domain of human CTLA-4 shown in SEQ ID NO:159 in no more
than
6 amino acid residues, and (b) comprises at least one amino acid substitution
at an amino
acid position corresponding to position 50, 54, 55, 56, 64, 65, 70, or 85
relative to the
polypeptide sequence of SEQ ID NO:159, wherein the polypeptide binds hCD80
and/or
hCD86 and/or an ECD of either or both, and/or inhibits an immune response in
vitro
and/or in vivo, or a complementary polynucleotide sequence thereof. Some such
nucleic
acids encode polypeptides comprising 2, 3, 4, 5, or 6 amino acid substitutions
at positions
relative to the sequence set forth in SEQ ID NO:159 selected from the group
consisting of
position 50, 54, 55, 56, 64, 65, 70, and 85. Some such nucleic acids encoding
polypeptides further comprising an amino acid substitution at a position
corresponding to
position 104 and/or 30 relative to SEQ 1D NO:159. Some such nucleic acids
encode
polypeptides comprising at least one amino acid substitution relative to SEQ
ID NO:159 at
position 70 (e.g., S70F), position 64 (e.g., S64P), position 50 (e.g., A50M),
position 54
(e.g., M54KN), position 65 (e.g., I65S), position 56 (e.g., N56D), position 55
(e.g.,
G55E), position 85 (e.g., M85A), and/or position 24 (e.g., A24E). Any such
polypeptide
may further comprise an amino acid substitution relative to SEQ ID NO:159 at
position
104 (optionally L104E/D, e.g., L104E), position 30 (e.g., T3ON/D/A), and/or
position 32
(e.g., V32I). Some such nucleic acids encode polypeptides comprising one or
more
substitutions at amino acid positions relative to SEQ ID NO:159 selected from
the group
consisting of A50M, M54K, G55E, N56D, S64P, I65S, and S70F. Some such encoded
polypeptides comprise a sequence having an amino acid length of about 118-130,
119-
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129, 120-128, 121- 127, 122-126, 123-125, or 124 amino acid residues.
Additional details
of the functional properties and characteristics of such polypeptides are
discussed above.
The invention also provides an isolated or recombinant nucleic acid comprising
a
polynucleotide sequence which encodes a polypeptide (e.g., mutant CTLA-4 ECD)
comprising a polypeptide sequence comprising (i) at least 95%, 96%, 97%, 98%,
99%, or
100% identity to any polypeptide sequence selected from the group consisting
of SEQ ID
NOS:1-73 and (ii) a phenylalanine residue at an amino acid position
corresponding to
position 70 of said polypeptide sequence selected from the group consisting of
SEQ ID
NO:1-73, wherein the polypeptide binds hCD80 and/or hCD86 or an ECD thereof
and/or
inhibits an immune response, or a complementary polynucleotide sequence
thereof. Some
such nucleic acids encode polypeptides comprising one or more of the following
relative
to the selected sequence: a glutamic acid residue at an amino acid position
corresponding
to position 24; an asparagine residue at an amino acid position corresponding
to position
30; an isoleucine residue at an amino acid position conesponding to position
32; a
methionine residue at an amino acid position corresponding to position 50; a
lysine residue
at an amino acid position corresponding to position 54; a glutamic acid
residue at an
amino acid position corresponding to position 55; an aspartic acid residue at
an amino acid
position corresponding to position 56; a proline residue at an amino acid
position
corresponding to position 64; a serine residue at an amino acid position
corresponding to
position 65; and a glutamic acid residue at an amino acid position
corresponding to
position 104. Some such nucleic acids encode polypeptides comprising a
polypeptide
sequence having a length of about 118-130, 119-129, 120-128, 121- 127, 122-
126, 123-
125, or 124 amino acid residues. Additional details of the functional
properties and
characteristics of such polypeptides are discussed above.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide (e.g., mutant
CTLA-4
ECD) comprising a polypeptide sequence which (a) differs from the polypeptide
sequence
of human CTLA-4 ECD polypeptide shown in SEQ ID NO:159 in no more than 6 amino
acid residues, and (b) comprises at least one amino acid substitution, wherein
said at least
one amino acid substitution is S70F, wherein amino acid residue positions are
numbered
according to SEQ ID NO:159, wherein the polypeptide that binds hCD80 and/or
hCD86
(and/or an ECD of either or both) and/or inhibits an immune response, or a
complementary
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polynucleotide sequence thereof. Some such nucleic acids encode a polypeptide
that
further comprises at least one amino acid substitution selected from the group
consisting
of A24E, T3ON, V321, D41G, A50M, M54K, G55E, N56D, S64P, 165S, M85A, L104E,
and 1106F. Some such nucleic acids encode polypeptides comprising a
polypeptide
sequence having a length of about 118-130, 119-129, 120-128, 121- 127,122-126,
123-
125, or 124 amino acid residues. Additional details of the functional
properties and
characteristics of such polypeptides are discussed above.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a polypeptide (e.g., mutant
CTLA-4
ECD) comprising a polypeptide sequence which (a) differs from the polypeptide
sequence
shown in SEQ lD NO:31 in no more than 6 amino acid residues. and (b) comprises
at least
one of the following: a methionine residue at a position corresponding to
position 50 of
SEQ .ED NO:31, a lysine residue at a position corresponding to position 54 of
SEQ ID
NO:31, a glutamic acid residue at a position corresponding to position 55 of
SEQ ID
NO:31, a proline residue at a position corresponding to position 64 of SEQ ID
NO:31, a
serine residue at a position corresponding to position 65 of SEQ ID NO:31, a
phenylalanine residue at a position corresponding to position 70 of SEQ ID
NO:31,
wherein amino acid residue positions are numbered according to SEQ ID NO:31,
and
wherein the polypeptide binds CD80 and/or CD86 and/or an ECD of either or
both, and/or
inhibits an immune response, or a complementary polynucleotide sequence
thereof. Some
such encoded polypeptides comprise a glutamic acid residue at a position
corresponding to
position 104, an asparagine acid residue at a position corresponding to
position 30, and/or
an isoleucine residue at a position corresponding to position 32 of SEQ ID
NO:31. Some
such nucleic acids encode polypeptides comprising a polypeptide sequence
having a
length of about 118-130, 119-129, 120-128, 121- 127, 122-126, 123-125, or 124
amino
acid residues. Additional details of the functional properties and
characteristics of such
polypeptides are discussed above.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence having at least 80%, 85%, 86%, 87%, 88%,
89%,
90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 100% identity to
at
least one polynucleotide sequence selected from the group consisting of SEQ ID
NOS:80-
158, 201-204, 223, and 224, or a complementary polynucleotide sequence
thereof,
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wherein the nucleic acid encodes a polypeptide that binds hCD80 and/or hCD86
and/or an
ECD of either or both, and/or suppresses an immune response, or a
complementary
polynucleotide sequence thereof. Exemplary nucleic acids comprising
polynucleotide
sequences identified by SEQ ID NOS:80-15S encode exemplary polypeptides
comprising
polypeptide sequences identified by SEQ ID NOS:1-79, respectively. Exemplary
nucleic
acids comprising polynucleotide sequences identified by SEQ ID NOS:201-204
encode
exemplary polypeptides comprising polypeptide sequences identified by SEQ ID
NOS:197-200, respectively.
In another aspect, the invention includes an isolated or recombinant nucleic
acid
comprising: (a) a polynucleotide sequence having at least 95%, 96%, 97%, 98%,
99%, or
100% identity to an RNA polynucleotide sequence, wherein the RNA
polynucleotide
sequence comprises a DNA sequence selected from the group consisting of SEQ ID
NOS: 80-158, 201-204, 223, and 224 in which all of the thymine nucleotide
residues in the
DNA sequence are replaced with uracil nucleotide residues; (b) a complementary
polynucleotide sequence of (a); or (c) a fragment of any polynucleotide
sequence of (a) or
(b), wherein the nucleic acid encodes a polypeptide that (i) binds CD80 and/or
CD86
and/or an ECD of either or both, and/or (ii) has an ability to suppress an
immune response
in vitro or in vivo (e.g., T cell activation or proliferation, cytokine
synthesis or production
(e.g., production of TNF-a, IFNI', IL-2), induction of activation markers
(e.g., CD25, IL-2
receptor), inflammation, anti-collagen antibody production, and/or T cell-
dependent
antibody response), or a polynucleotide sequence thereof.
The invention includes an isolated or recombinant nucleic acid encoding any
multimer of any polypeptide of the invention described above (e.g., dimer,
tetramer, etc.).
A discussed in greater detail elsewhere, a dimer comprising two polypeptides
of the
invention (including two fusion proteins) is typically formed during cellular
processing by
the generation of one or more covalent disulfide bonds between cysteine
residue(s) in one
polypeptide and cysteine residue(s) in the second polypeptide. Other multimers
may be
similarly formed. For example, in a non-limiting aspect, the invention
provides an
isolated or recombinant nucleic acid comprising a polynucleotide sequence
which encodes
a recombinant polypeptide dimer comprising two polypeptides, wherein each such
polypeptide comprises a polypeptide sequence having at least 95%, 96%, 97%,
98%, 99%,
or 100% identity to a sequence selected from the group consisting of SEQ ID
NOS:1-73,
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wherein the dimer binds hCD80 and/or hCD86 and/or inhibits an immune response,
or a
complementary polynucleotide sequence thereof. Also included is an isolated or
recombinant nucleic acid comprising a polynucleotide sequence which encodes a
polypeptide dimer comprising two polypeptides, wherein each such polypeptide
differs
from the polypeptide sequence of the hCTLA-4 ECD (SEQ ID NO:159) in no more
than 6
amino acid residues and comprises at least one substitution at an amino acid
position
relative to SEQ ID NO:159 selected from the group consisting of A50M, M54K,
G55E,
N56D, S64P, 165S, and S70F; and which polypeptide optionally further comprises
the
substitution L104E, wherein said dimer binds hCD80 and/or hCD86 and/or
inhibits an
immune response, or a complementary polynucleotide sequence thereof.
Additional
details of the functional properties of such dimers are discussed above.
The invention also provides an isolated or recombinant nucleic acid encoding
any
fusion protein of the invention, including any multimeric fusion protein of
the invention
(e.g., dimers, tetramers, etc.). In one aspect, the invention provides an
isolated or
recombinant nucleic acid comprising a polynucleotide sequence which encodes a
fusion
protein comprising (a) a polypeptide comprising a polypeptide sequence that
has at least
80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 100%
identity to at least one polypeptide sequence selected from the group
consisting of SEQ ID
NOS:1-73, and (b) an Ig polypeptide, wherein the fusion protein binds CD80
and/or
CD86 (and/or CD80-Ig and/or CD86-1g), and/or has an ability to suppress an
immune
response, or a complementary polynucleotide sequence thereof. The Ig
polypeptide may
comprise an Ig Fc polypeptide, including, e.g., an Ig Fc polypeptide
comprising a
polypeptide sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity
to a
polypeptide sequence selected from the group consisting of SEQ ID NOS:184-186
and
218. A dimeric fusion protein comprising two such monomeric fusion proteins is
typically
formed during cellular processing by the generation of covalent disulfide
bonds between
cysteine residues in one monomeric fusion protein and cysteine residues in the
second
monomeric fusion protein. Other multimers may be similarly formed. Additional
details
of the functional properties and characteristics of such fusion proteins are
discussed above.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a protein dimer (e.g.,
mutant CTLA-
4-Ig dimer) comprising two monomeric fusion proteins (e.g., monomeric mutant
CTLA-4-
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Ig), each monomeric fusion protein comprising.: (a) a polypeptide (e.g.,
mutant CTLA-4
ECD) comprising a polypeptide sequence having at least 90%, 91%, 92%, 93%,
94%,
95%, 96%, 97%, 98%, 99%, 99.5%. or 100% identity to at least one polypeptide
sequence
selected from the group consisting of SEQ ID NOS:1-73, and (b) an Ig
polypeptide,
wherein the fusion protein dimer binds CD80 and/or CD86 (and/or CD80-Ig and/or
CD86-
Ig), and/or has an ability to inhibit or suppress an immune response, or a
complementary
polynucleotide sequence thereof. The two monomeric fusion proteins, upon
expression,
are linked together via at least one disulfide bond formed between two
cysteine residues
present in each monomeric mutant CTLA-4-Ig fusion protein. The Ig polypeptide
may
comprise an Ig Fc polypeptide, including, e.g., an Ig Fc polypeptide
comprising a
sequence having at least 95%, 96%, 97%, 98%, 99%, or 100% identity to a
sequence
selected from the group consisting of SEQ ID NOS:184-186 and 218. In some
instances,
the C-terminus of the polypeptide of (a) is covalently linked or fused to the
N-terminus of
the Ig Fc polypeptide of (b). Additional details of the functional properties
and
characteristics of such dimers are discussed above.
A stop codon (e.g., tga) is typically included at the C-terminus of each
nucleic acid
sequence when the sequence is included in an expression vector for expression
of a protein
of interest. For example, each of the nucleotide sequences of the invention
encoding a
mutant CTLA-4 polypeptide or mutant CTLA-4 fusion protein may optionally
further
include a stop codon at the C terminus, such as TAA. A different stop codon
may be
substituted for the TAA, such as a TGA stop codon. A nucleic acid sequence
encoding a
wild-type fusion protein (e.g., hCTLA-4-Ig, hCD86-Ig, etc.) may also include a
stop
codon at its C-terminus. Each of the nucleotide sequences may optionally
further includes
at the N-terminus a nucleotide sequence encoding a signal peptide to
facilitate secretion of
a mutant CTLA-4 polypeptide or fusion protein.
Exemplary mutant CTLA-4-Ig fusion protein dimers include those comprising
polypeptide sequences shown in SEQ ID NOS:74-79, 197-200, 205-214, and 219-
222.
Exemplary nucleic acids encoding the mutant CTLA-4 Ig fusion proteins of SEQ
ID
NOS:74-79, 197-200, 220 and 222 are set forth in SEQ ID NO:153-158, 201-204,
and
223-224, respectively. The fusion protein sequences of SEQ ID NOS:205-210, 211-
214,
219, and 221 are identical to the protein sequences of SEQ ID NOS:74-79, 197-
200, 220,
and 222, respectively, except that the protein sequences of SEQ ID NOS:205-210
do not
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include the C-terminal lysine (K) residue; as explained above, it is believed
that the
predicted C-terminal lysine residue, which is encoded by the AAA codon
immediately
preceding the TAA stop codon of each such polynucleotide sequence, is cleaved
from the
resulting fusion protein during processing or secretion. The nucleic acid
sequences of
SEQ ID NOS:153-158, 201-204, and 223-224 encode the fusion protein sequences
of SEQ
ID NOS:74-79, 197-200, 220, and 222, respectively, each of which after
cleavage/loss of
the C-terminal K residue results in the fusion protein sequences shown in SEQ
ID
NOS:205-210, 211-214, 219, and 221, respectively.
Each of the polynucleotide sequences SEQ ID NOS:153-158, 201-204, and 223-
224 also includes at its N-terminus a nucleotide sequence encoding the signal
peptide
shown in SEQ ID NO:181 or 215, which signal peptide is ultimately cleaved to
form the
mature fusion protein. Nucleotide residues 1-111 of each of the polynucleotide
sequences
of SEQ ID NOS:153-158, 201-204, and 223-224, as counted from the N-terminus of
each
such polynucleotide sequence (nucleotide residues 1-111 are set forth in SEQ
ID NO:215),
encode the 37-amino acid residue WT hCTLA-4 signal peptide shown in SEQ ID
NO:216,
which signal peptide is ultimately cleaved upon expression of the mature
mutant CTLA-4
fusion protein monomer or dimer; thus, for each of the nucleic acid sequences
of SEQ ID
NOS:153-158, 201-204, and 223-224, the first codon encoding the first amino
acid residue
(methionine) of the mature IgG2 fusion protein is composed of nucleotide
residues 112-
114 of said nucleotide sequence. As noted above, in some instances, the signal
peptide
sequence may comprise only amino acid residues 1-35 as shown in SEQ ID NO:182
and
the nucleotide sequence encoding this 35-amino acid residue signal peptide is
shown in
SEQ ID NO:181. Nevertheless, the encoded lysine (K) and alanine (A) residues
at
positions 36 and 37, respectively (encoded by the two codons AAA-GCC), are not
present
in the resulting mature mutant CTLA-4-Ig fusion protein and are believed
cleaved from
the mature mutant CTLA-4-Ig fusion protein during processing. The mature
mutant
CTLA-4 protein sequence typically begins with the methionine residue present
at amino
acid residue position 38 of the encoded mutant CTLA-4-Ig fusion protein.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a fusion protein dimer
(e.g., mutant
CTLA-4-Ig dimer) comprising two identical monomeric fusion proteins (e.g.,
monomeric
mutant CTLA-4-Ig), wherein each such monomeric fusion protein comprises a
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polypeptide sequence haying at least 95%, 96%, 97%, 98%, 99% or 100% identity
to a
polypeptide sequence selected from the group consisting of SEQ ID NOS:74-79,
197-200,
205-214, and 219-222, wherein the fusion protein dimer binds CD80 and/or CD86
(and/or
a CD80-Ig and/or CD86-Ig), and/or has an ability to inhibit an immune
response, or a
complementary polynucleotide sequence thereof. Also provided is an isolated or
recombinant nucleic acid encoding such monomeric fusion protein which binds
CD80
and/or CD86 (and/or a CD80-Ig and/or CD86-1g, and/or has an ability to inhibit
an
immune response. Exemplary mutant CTLA-4-Ig fusion protein dimers include
those
comprising polypeptide sequences shown in SEQ ID NOS:74-79, 197-200, 220, and
222;
exemplary nucleic acids encoding such mutant CTLA-4 Ig fusion proteins, which
are
expressed as mutant CTLA-4-Ig fusion protein dimers, include those comprising
polynucleotide sequences shown in SEQ ID NOS:153-158, 201-204, and 223-224,
respectively. Additional exemplary mutant CTLA-4-Ig fusion protein dimers
comprise the
polypeptide sequences of SEQ ID NOS:205-210, 211-214, 219, and 222, which are
expressed as fusion protein dimers; these fusion proteins lack the C-terminal
lysine residue
because it is typically cleaved during processing or prior to secretion.
Exemplary nucleic
acids encoding these fusion protein sequences with the C-terminal lysine (the
lysine is
cleaved subsequently) include the polynucleotide sequences of SEQ ID NOS:153-
158,
201-204, and 223-224, respectively.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a fusion protein, wherein
said fusion
protein comprises a polypeptide sequence having at least 95%, 96%, 97%, 98%,
99% or
100% identity to a polypeptide sequence selected from the group consisting of
SEQ ID
NOS:74-79, 197-200, 205-214, and 219-222, wherein the fusion protein binds
CD80
and/or CD86 (and/or a CD80-Ig and/or CD86-Ig), and/or has an ability to
inhibit an
immune response, or a complementary polynucleotide sequence thereof.
In another aspect, the invention includes an isolated or recombinant nucleic
acid
comprising a nucleotide sequence having at least 95%, 96%, 97%, 98%, 99% or
100%
sequence identity to a polynucleotide sequence selected from the group
consisting of SEQ
ID NOS:153-158, 201-204, and 223-224, wherein such nucleic acid encodes a
mutant
CTLA-4-Ig protein dimer binds CD80 and/or CD86 (and/or a CD80-Ig and/or CD86-
Ig),
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and/or has an ability to inhibit an immune response, or a complementary
polynucleotide
sequence thereof.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a fusion protein dimer
(e.g., mutant
CTLA-4-Ig dimer) comprising two monomeric fusion proteins (e.g., monomeric
mutant
CTLA-4-Ig), wherein each such monomeric fusion protein comprises: (1) a
polypeptide
(e.g.. mutant CTLA-4 ECD) which comprises a polypeptide sequence which differs
from a
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73 in
no more
than 6 amino acid residues, and wherein the amino acid residue in the
polypeptide
sequence at position 41, 50, 54, 55, 56, 64, 65, 70, or 85 is identical to the
amino acid
residue at the corresponding position of said selected polypeptide sequence
(e.g., a
polypeptide selected from SEQ ID NOS: -73), and (2) an Ig Fe polypeptide,
wherein the
dimer binds CD80 and/or CD86 (and/or CD80-Ig and/or CD86-Ig), and/or inhibits
an
immune response, or a complementary polynucleotide sequence thereof.
Additional
details of the functional properties and characteristics of such dimers are
discussed above.
Also provided is a recombinant or isolated nucleic acid comprising a
nucleotide sequence
which encodes such a monomeric fusion protein which binds CD80 and/or CD86
(and/or
CD80-Ig and/or CD86-Ig) and/or has an ability to inhibit an immune response.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
comprising a polynucleotide sequence which encodes a fusion protein dimer
(e.g., mutant
CTLA-4-1g dimer) comprising two monomeric fusion proteins (e.g., two monomeric
mutant CTLA-4-Ig), wherein each such monomeric fusion protein comprises: (1) a
mutant
CTLA-4 extracellular domain polypeptide comprising a polypeptide sequence
which (a)
differs from a polypeptide sequence selected from the group consisting of SEQ
ID NOS:1-
73 in no more than 6 amino acid residues, and (b) comprises at least one amino
acid
substitution at an amino acid position corresponding to position 50, 54, 55,
56, 64, 65, 70,
or 85 relative to the polypeptide sequence of SEQ ID NO:159; and (2) an Ig
polypeptide,
wherein the fusion protein dimer binds CD80 and/or CD86 (and/or CD80-Ig and/or
CD86-
Ig), and/or inhibits an immune response, or a complementary polynucleotide
sequence
thereof. Additional details of the functional properties and characteristics
of such dimers
are discussed above. The 1g polypeptide may comprise an Ig Fc polypeptide,
including,
e.g., an Ig Fe polypeptide comprising a sequence having at least 90%, 91%,
92%, 93%,
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94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a sequence selected from the
group
consisting of SEQ ID NOS:184-186 and 218. Some such polypeptides of (a)
comprise at
least one substitution at an amino acid position relative to SEQ ID NO:159
selected from
the group consisting of A50M, M54K, G55E, N56D, S64P, I65S, and S70F. Some
such
polypeptides of (a) further comprise an amino acid substitution relative to
SEQ ID NO:159
at position 104 (e.g., L104E/D), position 30 (e.g., T3ON/D/A), and/or position
32
(e.g.,V32I). Also provided is a recombinant or isolated nucleic acid encoding
such
monomeric fusion protein which binds CD80 and/or CD86 (and/or CD80-Ig and/or
CD86-
Ig) and/or has an ability to inhibit an immune response.
In another aspect, the invention includes an isolated or recombinant nucleic
acid
encoding a fusion protein dimer (e.g., mutant CTLA-4-Ig dimer) comprising two
monomeric fusion proteins (e.g., monomeric mutant CTLA-4-Ig), wherein each
such
monomeric fusion protein comprises: (1) a polypeptide (e.g., mutant CTLA-4
ECD)
comprising a polypeptide sequence which (i) has at least 92%, 93%, 94%, 95%,
96%,
97%, 98%, 99%, or 100% identity to a polypeptide sequence selected from the
group
consisting of SEQ ID NOS:1-73 and (ii) includes a phenylalanine residue at an
amino acid
position corresponding to position 70 of said polypeptide sequence selected
from the
group consisting of SEQ ID NO:1-73; and (2) an Ig polypeptide, wherein the
fusion
protein dimer binds CD80 and/or CD86 (and/or CD80-Ig and/or CD86-Ig), and/or
has an
ability to inhibit an immune response, or a complementary polynucleotide
sequence
thereof. The encoded Ig polypeptide may comprise an Ig Fe polypeptide
comprising a
polypeptide sequence having at least 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%,
or
100% identity to a polypeptide sequence selected from the group consisting of
SEQ ID
NOS:184-186 and 218. Some such encoded dimers comprise one or more of the
following
relative to said selected polypeptide sequence of (1)(i): a Glu residue at a
position
con-esponding to position 24; an Asn at a position corresponding to position
30; an Ile
residue at a position corresponding to position 32; a Met residue at a
position
corresponding to position 50; a Lys residue at a position corresponding to
position 54; a
Glu residue at a position corresponding to position 55; an Asp residue at a
position
corresponding to position 56; a Pro residue at a position corresponding to
position 64; a
Ser residue at an amino acid position corresponding to position 65; and a Glu
residue at a
position corresponding to position 104. Additional details of the functional
properties and
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characteristics of such dimers are discussed above. Also provided is a
recombinant or
isolated nucleic acid comprising a nucleotide sequence which encodes such a
monomeric
fusion protein which binds CD80 and/or CD86 (and/or CD80-Ig and/or CD86-Ig)
and/or
has an ability to inhibit an immune response.
In another aspect, the invention includes an isolated or recombinant nucleic
acid
encoding fusion protein dimer (e.g., mutant CTLA-4-Ig dimer) comprising two
monomeric fusion proteins (e.g., monomeric mutant CTLA-4-Ig), wherein each
such
monomeric fusion protein comprises: (1) a polypeptide (e.g., mutant CTLA-4
ECD)
comprising a polypeptide sequence which (a) differs from the polypeptide
sequence of the
human CTLA-4 ECD polypeptide shown in SEQ ID NO:159 in no more than 6 amino
acid
residues, and (b) comprises at least one amino acid substitution, wherein said
at least
amino acid substitution comprises S70F, wherein amino acid residue positions
are
numbered according to SEQ ID NO:159; and (2) an IgG Fc polypeptide, wherein
said
dimer binds hCD80 and/or hCD86 (and/or hCD86-Ig and/or hCD86-Ig), and/or
inhibits an
immune response, or a complementary polynucleotide sequence thereof. The Ig Fc
polypeptide may comprise a sequence having at least 95%, 96%, 97%, 98%, 99%,
or
100% identity to a polypeptide sequence selected from the group consisting of
SEQ ID
NOS:184-186 and 218. The encoded polypeptide of (1) may further comprise at
least one
amino acid substitution selected from the group consisting of A24E, T3ON,
V32I, D41G,
A50M, M54K, G55E, N56D, S64P, I65S, M85A, L104E, and 1106F. Additional details
of
the functional properties and characteristics of such dimers are discussed
above. Also
provided is a recombinant or isolated nucleic acid comprising a nucleotide
sequence which
encodes such a monomeric fusion protein which binds CD80 and/or CD86 (and/or
CD80-
Ig and/or CD86-Ig) and/or has an ability to inhibit an immune response.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
encoding fusion protein dimer (e.g., mutant CTLA-4-1g dimer) comprising two
monomeric fusion proteins (e.g., monomeric mutant CTLA-4-Ig), wherein each
such
monomeric fusion protein comprises: (1) a polypeptide (e.g., mutant CTLA-4
ECD)
comprising a polypeptide sequence which (a) differs from the polypeptide
sequence of
SEQ ID NO:31 in no more than 6 amino acid residues, and (b) comprises at least
one of
the following: a methionine residue at a position corresponding to position 50
of SEQ ID
NO:31, a lysine residue at a position corresponding to position 54 of SEQ ID
NO:31, a
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glutamic acid residue at a position corresponding to position 55 of SEQ ID
NO:31, a
proline residue at a position corresponding to position 64 of SEQ ID NO:31, a
serine
residue at a position corresponding to position 65 of SEQ ID NO:31, a
phenylalanine
residue at a position corresponding to position 70 of SEQ ID NO:31, wherein
amino acid
residue positions are numbered according to SEQ ID NO:31; and (2) an Ig
polypeptide,
wherein said dimer binds hCD80 and/or hCD86 (and/or hCD86-Ig and/or hCD86-Ig),
and/or inhibits an immune response, or a complementary polynucleotide sequence
thereof.
The Ig polypeptide may comprise an Ig Fc polypeptide, including, e.g., an Ig
Fc
polypeptide comprising a sequence having at least 95%, 96%, 97%, 98%, 99%, or
100%
identity to a sequence selected from the group consisting of SEQ ID NOS:184-
186 and
218. In some such dimers or monomers, the polypeptide of (1) comprises a
glutamic acid
residue at a position corresponding to position 104, an asparagine acid
residue at a position
corresponding to position 30, and/or an isoleucine residue at a position
corresponding to
position 32 of SEQ ID NO:31. Additional details of the functional properties
and
characteristics of such dimers are discussed above. Also provided is a
recombinant or
isolated nucleic acid comprising a nucleotide sequence which encodes such a
monomeric
fusion protein which binds CD80 and/or CD86 (and/or CD80-Ig and/or CD86-Ig)
and/or
has an ability to inhibit an immune response.
Also included in the invention are fragments of any such nucleic acids of the
invention described above, wherein such fragments encode a polypeptide that
binds
hCD80 and/or hCD86 and/or an ECD of either or both, and/or has an ability to
suppress or
inhibit an immune response. Many fragments of these nucleic acids will express
polypeptides that bind hCD80 and/hCD86 or an ECD thereof, or suppress an
immune
response, which properties can be readily identified with reasonable
experimentation.
Nucleotide fragments typically comprise at least 250, 300, 400, 500, 600, 700,
800, 900,
950, 1000 or more nucleotide bases.
The invention includes an isolated or recombinant nucleic acid that encodes a
protein comprising a signal peptide and a polypeptide of the invention (which
includes a
dimeric or monomeric fusion protein of the invention), such as a mutant CTLA-4
ECD
polypeptide or mutant CTLA-4-Ig fusion protein of the invention, that binds
CD80 and/or
CD86 and/or suppresses an immune response in in vitro or in vivo assays and/or
methods
as described in detail elsewhere herein. The encoded signal peptide sequence,
which
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directs secretion of the mature polypeptide through a prokaryotic or
eukaryotic cell
membrane, is typically covalently linked to the amino terminus of said
polypeptide. A
variety of signal peptides can be used, including, e.g., the signal peptide
sequence set forth
in SEQ ID NO:182, which is encoded by, e.g., the nucleotide sequence shown in
SEQ ID
NO:181, or the signal peptide sequence set forth in SEQ ID NO:216, which is
encoded by,
e.g., the nucleotide sequence shown in SEQ ID NO:215. The invention also
include an
isolated or recombinant nucleic acid which encodes a protein comprising a
signal peptide,
mutant CTLA-4 ECD polypeptide, transmembrane domain, and/or cytoplasmic domain
as
discussed detail above.
The signal peptide sequence of the full-length human CTLA-4 protein can be
used
to direct expression or secretion of a recombinant mutant CTLA-4 ECD
polypeptide or
mutant CTLA-4-Ig fusion protein of the invention. In one aspect, the signal
peptide (SP)
of the hCTLA-4 protein comprises amino acid residues 1-37 of the hCTLA-4
protein; this
signal peptide sequence is shown in SEQ ID NO:216. In this instance, the
mature
hCTLA-4 protein typically begins with the methionine residue at position 38,
and the
amino acid residues of the mature hCTLA-4 protein are numbered accordingly
beginning
with this methionine residue being designated as the first amino acid (i.e.,
occupying
position 1). Thus, a signal peptide comprising the peptide sequence shown in
SEQ ID
NO:216 can be fused or linked to the amino (N) terminus of a mutant CTLA-4 ECD
polypeptide or mutant CTLA-4-Ig fusion protein of the invention, such as by a
covalent
linkage, so as to facilitate expression or secretion of the mutant CTLA-4 ECD
polypeptide
or mutant CTLA-4-Ig fusion protein, respectively. An exemplary nucleic acid
comprising
a nucleotide sequence that encodes the hCTLA-4 signal peptide sequence of SEQ
ID
NO:216 is set forth in SEQ ID NO:215.
When the signal peptide sequence of SEQ ID NO:216 is fused to linked to the N-
terminus of a mutant CTLA-4 ECD polypeptide or mutant CTLA-4-Ig fusion
protein,
upon expression or secretion of said polypeptide or fusion protein, the signal
peptide is
cleaved; the resulting mature mutant CTLA-4 ECD polypeptide or mature mutant
CTLA-
4-Ig fusion protein typically begins with the methionine residue at position
38, and the
amino acid residues of the mature mutant CTLA-4 ECD polypeptide or mature
mutant
CTLA-4-Ig fusion protein are numbered accordingly beginning with this
methionine
residue being designated as the first amino acid (i.e., occupying position 1).
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The invention includes an isolated or recombinant polypeptide comprising a
signal
peptide (e.g., SEQ ID NO:216) and a mutant CTLA-4 ECD polypeptide (e.g., a
sequence
selected from the group of SEQ ID NOS:1-73), wherein the signal peptide is
covalently
linked to the N-terminus of the mutant CTLA-4 ECD polypeptide. Also included
is an
isolated or recombinant polypeptide comprising a signal peptide (e.g., SEQ ID
NO:216)
and a mutant CTLA-4-Ig (e.g., a sequence selected from the group of SEQ ID
NOS:74-79,
197-200, 205-214, and 219-222), wherein the signal peptide is covalently
linked to the N-
terminus of the mutant CTLA-4-Ig. Also provided is an isolated or recombinant
nucleic
acid comprising a nucleotide sequence (e.g., SEQ ID NO:215) encoding a signal
peptide
(e.g., SEQ NO:216) and a nucleotide sequence encoding a mutant CTLA-4 ECD
polypeptide (e.g., a sequence selected from the group of SEQ ID NOS:1-73) or a
mutant
CTLA-4-Ig fusion protein (e.g., a sequence selected from the group of SEQ ID
NOS:74-
79, 197-200, 205-214, and 219-222).
In an alternative aspect, the signal peptide of the full-length hCTLA-4
protein
comprises residues 1-35 of the full-length hCTLA-4 protein; this signal
peptide comprises
the peptide sequence shown in SEQ 1D NO:182. In this instance, the two amino
acid
residues lysine (K) and alanine (A) at positions 36 and 37, respectively, of
the hCTLA-4
protein are nevertheless typically absent from the mature secreted hCTLA-4
protein as
determined by protein sequencing. Thus, the resulting mature hCTLA-4 protein
similarly
begins with the methionine residue at position 38, and the amino acid residues
of the
mature hCTLA-4 protein are numbered accordingly beginning with this methionine
residue at position 38 of the hCTLA-4 protein being designated as the first
amino acid of
the mature hCTLA-4 protein. Because amino acid residues lysine (K) and alanine
(A) at
positions 36 and 37, respectively, of the full-length hCTLA-4 protein are not
present in the
resulting mature hCTLA-4 protein, it is believed they have been cleaved from
the mature
hCTLA-4 protein during processing. An exemplary nucleic acid comprising a
nucleotide
sequence that encodes the hCTLA-4 signal peptide sequence (SEQ ID NO:182) is
shown
in SEQ ID NO:181.
A signal peptide comprising the peptide sequence shown in SEQ ID NO:182 can
be fused or linked to the N-terminus of a mutant CTLA-4 ECD polypeptide or
mutant
CTLA-4-Ig fusion protein of the invention, such as by a covalent linkage, so
as to
facilitate expression or secretion of the mutant CTLA-4 ECD polypeptide Or
mutant
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CTLA-4-Ig fusion protein, respectively. When the signal peptide sequence of
SEQ ID
NO:182 is fused or linked to the N-terminus of a mutant CTLA-4 ECD polypeptide
or
mutant CTLA-4-Ig fusion protein, upon expression or secretion of the
polypeptide or
fusion protein, the signal peptide is cleaved; the resulting mature mutant
CTLA-4 ECD
polypeptide or mature mutant CTLA-4-Ig fusion protein nevertheless typically
begins with
the methionine residue at position 38, and the amino acid residues of the
mature mutant
CTLA-4 ECD polypeptide or mature mutant CTLA-4-Ig fusion protein are numbered
accordingly beginning with this methionine residue being designated as the
first amino
acid (i.e., occupying position 1). Because amino acid residues lysine (K) and
alanine (A)
at positions 36 and 37, respectively, of the full-length hCTLA-4 protein are
not present in
the resulting mature mutant CTLA-4 ECD polypeptide or mature mutant CTLA-4-Ig
fusion protein, it is believed they have been cleaved from said mutant CTLA-4
ECD
polypeptide or mutant CTLA-4-Ig fusion protein during processing.
The invention includes an isolated or recombinant polypeptide comprising a
signal
peptide (e.g., SEQ ID NO:182) and a mutant CTLA-4 ECD polypeptide (e.g., a
sequence
selected from the group of SEQ ID NOS:1-73), wherein the signal peptide is
covalently
linked to the N-terminus of the mutant CTLA-4 ECD polypeptide. Also included
is an
isolated or recombinant polypeptide comprising a signal peptide (e.g., SEQ ID
NO:182)
and a mutant CTLA-4-Ig (e.g., a sequence selected from the group of SEQ ID
NOS:74-79,
197-200, 205-214, and 219-222), wherein the signal peptide is covalently
linked to the N-
terminus of the mutant CTLA-4-Ig. Also provided is an isolated or recombinant
nucleic
acid comprising a nucleotide sequence (e.g., SEQ ID NO:181) encoding a signal
peptide
(e.g., SEQ NO:182) and a nucleotide sequence encoding a mutant CTLA-4 ECD
polypeptide (e.g., a sequence selected from the group of SEQ ID NOS:1-73) or a
mutant
CTLA-4-Ig fusion protein (e.g., a sequence selected from the group of SEQ ID
NOS:74-
79, 197-200, 205-214, and 219-222).
A nucleic acid of the invention can further comprise one or more suitable
additional nucleotide sequences. For example, given that a polypeptide of the
invention
(which includes a fusion protein of the invention) can comprise one or more
additional
polypeptide sequences, such as, e.g., a polypeptide purification subsequence
(such as, e.g.,
a subsequence is selected from an epitope tag, a FLAG tag, a polyhistidine
sequence, and
a GST fusion), signal peptide sequence, etc., the invention includes nucleic
acids that
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encode all such polypeptides comprising such additional sequences. Exemplary
signal
peptides, which upon expression are typically covalently linked to the N-
terminal of a
polypeptide of the invention, are discussed above. For example, a nucleic acid
encoding a
polypeptide sequence of any of SEQ ID NOS:1-79, 197-200, 205-214, and 219-222
can
further comprise a nucleic acid encoding a signal peptide, such as the signal
peptide
sequence of SEQ ID NO:182, such as, e.g., the nucleotide sequence set forth in
SEQ ID
NO:181, or the signal peptide sequence set forth in SEQ ID NO:216, which is
encoded by,
e.g., the nucleotide sequence shown in SEQ ID NO:215. Such nucleotide
sequences can
be directly fused together, in appropriate reading frame, such that the
resulting nucleic
acid comprises a nucleotide sequence encoding a signal peptide of the
invention and a
nucleotide sequence encoding a polypeptide of the invention.
A nucleic acid of the invention can be isolated by any suitable technique, of
which
several are known in the art. An isolated nucleic acid of the invention (e.g.,
a nucleic acid
that is prepared in a host cell and subsequently substantially purified by any
suitable
nucleic acid purification technique) can be re-introduced into a host cell or
re-introduced
into a cellular or other biological environment or composition wherein it is
no longer the
dominant nucleic acid species and is no longer separated from other nucleic
acids.
Nearly any isolated or recombinant nucleic acid of the invention can be
inserted in
or fused to a suitable larger nucleic acid molecule (including e.g., but not
limited to, a
chromosome, a plasmid, an expression vector or cassette, a viral genome, a
gene sequence,
a linear expression element, a bacterial genome, a plant genome, or an
artificial
chromosome, such as a mammalian artificial chromosome (MAC), or the yeast and
bacterial counterparts thereof (i.e., a YAC or a BAC) to form a recombinant
nucleic acid
using standard techniques. As another example, an isolated nucleic acid of the
invention
can be fused to smaller nucleotide sequences, such as promoter sequences,
immunostimulatory sequences, and/or sequences encoding other amino acids, such
as
other antigen epitopes and/or linker sequences to form a recombinant nucleic
acid.
In some instances, a recombinant or synthetic nucleic acid may be generated by
chemical synthesis techniques applied outside of the context of a host cell
(e.g., a nucleic
acid produced through polymerase chain reaction (PCR) or chemical synthesis
techniques,
examples of which are described further herein).
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Nucleic acids encoding polypeptides (including fusion proteins) of the
invention
can have any suitable chemical composition that permits the expression of a
polypeptide
of the invention or other desired biological activity (e.g., hybridization
with other nucleic
acids). The polynucleotides of the invention can be in the form of RNA or in
the form of
DNA, and include mRNA, cRNA, recombinant or synthetic RNA and DNA, and cDNA.
The nucleic acids of the invention are typically DNA molecules, and usually
double-
stranded DNA molecules. However, single-stranded DNA, single-stranded RNA,
double-
stranded RNA, and hybrid DNA/RNA nucleic acids or combinations thereof
comprising
any of the nucleotide sequences of the invention also are provided. A nucleic
acid of the
invention can include any suitable nucleotide base, base analog, and/or
backbone (e.g., a
backbone formed by, or including, a phosphothioate, rather than
phosphodiester, linkage,
e.g., DNA comprising a phosphothioate or phosphorothioate backbone). A nucleic
acid of
the invention, if single-stranded, can be the coding strand or the non-coding
(i.e., antisense
or complementary) strand. In addition to a nucleotide sequence encoding a
polypeptide of
the invention (e.g., nucleotide sequence that comprise the coding sequence of
a mutant
CTLA-4 ECD polypeptide or mutant CTLA-4-Ig), the polynucleotide of the
invention can
comprise one or more additional coding nucleotide sequences, so as to encode,
e.g., a
fusion protein, targeting sequence (other than a signal sequence), or the like
(more
particular examples of which are discussed further herein), and/or can
comprise non-
coding nucleotide sequences, such as introns, terminator sequence, or 5'
and/or 3'
untranslated regions, which regions can be effective for expression of the
coding sequence
in a suitable host, and/or control elements, such as a promoter (e.g.,
naturally occurring or
recombinant or shuffled promoter).
Modifications to a nucleic acid are particularly tolerable in the 3rd position
of an
mRNA codon sequence encoding such a polypeptide. In particular aspects, at
least a
portion of the nucleic acid comprises a phosphorothioate backbone,
incorporating at least
one synthetic nucleotide analog in place of or in addition to the naturally
occurring
nucleotides in the nucleic acid sequence. Also or alternatively, the nucleic
acid can
comprise the addition of bases other than guanine, adenine, uracil, thymine,
and cytosine.
Such modifications can be associated with longer half-life, and thus can be
desirable in
nucleic acids vectors of the invention. Thus, in one aspect, the invention
provides
recombinant nucleic acids and nucleic acid vectors (discussed further below),
which
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nucleic acids or vectors comprise at least one of the aforementioned
modifications, or any
suitable combination thereof, wherein the nucleic acid persists longer in a
mammalian host
than a substantially identical nucleic acid without such a modification or
modifications.
Examples of modified and/or non-cytosine, non-adenine, non-guanine, non-
thymine
nucleotides that can be incorporated in a nucleotide sequence of the invention
are provided
in, e.g., the MANUAL OF PA ________________________________________ IENT
EXAMINING PROCEDURE 2422 (7th Revision ¨ 2000).
It is to be understood that a nucleic acid encoding at least one of the
polypeptides
of the invention (which includes a fusion protein of the invention), including
those
described above and elsewhere herein, is not limited to a sequence that
directly codes for
expression or production of a polypeptide of the invention. For example, the
nucleic acid
can comprise a nucleotide sequence which results in a polypeptide of the
invention
through intein-like expression (as described in, e.g., Colson and Davis (1994)
Mol.
Microbiol. 12(3):959-63, Duan et al. (1997) Cell 89(4):555-64, Perler (1998)
Cell 92(1):1-
4, Evans et al. (1999) Biopolymers 51(5):333-42, and de Grey, Trends
Biotechnol.
18(9):394-99 (2000)), or a nucleotide sequence which comprises self-splicing
introns (or
other self-spliced RNA transcripts), which form an intermediate recombinant
polypeptide-
encoding sequence (as described in, e.g., U.S. Patent No. 6,010,884). The
nucleic acid
also or alternatively can comprise sequences which result in other splice
modifications at
the RNA level to produce an mRNA transcript encoding the polypeptide and/or at
the
DNA level by way of trans-splicing mechanisms prior to transcription
(principles related
to such mechanisms are described in, e.g., Chabot, Trends Genet. (1996)
12(11):472-78,
Cooper (1997) Am. J. Hum. Genet. 61(2):259-66, and Hertel et al. (1997) CUM
Opin.
Cell. Biol. 9(3):350-57). Due to the inherent degeneracy of the genetic code,
several
nucleic acids can code for any particular polypeptide of the invention. Thus,
for example,
any of the particular nucleic acids described herein can be modified by
replacement of one
or more codons with an equivalent codon (with respect to the amino acid called
for by the
codon) based on genetic code degeneracy. Other nucleotide sequences that
encode a
polypeptide having the same or a functionally equivalent sequence as a
polypeptide
sequence of the invention can also be used to synthesize, clone and express
such
polypeptide.
In general, any of the nucleic acids of the invention can be modified to
increase
expression in a particular host, using the techniques exemplified herein with
respect to the
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above-described nucleic acids encoding a polypeptide of the invention (e.g.,
nucleic acids
encoding mutant CTLA-4 ECD or mutant CTLA-4-Ig). Any of the nucleic acids of
the
invention as described herein may be codon optimized for expression in a
particular
mammal (normally humans). A variety of techniques for codon optimization are
known in
the art. Codons that are utilized most often in a particular host are called
optimal codons,
and those not utilized very often are classified as rare or low-usage codons
(see, e.g.,
Zhang, S. P. et al. (1991) Gene 105:61-72). Codons can be substituted to
reflect the
preferred codon usage of the host, a process called "codon optimization" or
"controlling
for species codon bias." Optimized coding sequence comprising codons preferred
by a
particular prokaryotic or eukaryotic host can be used to increase the rate of
translation or
to produce recombinant RNA transcripts having desirable properties, such as a
longer half-
life, as compared with transcripts produced from a non-optimized sequence.
Techniques
for producing codon-optimized sequences are known (see, e.g., E. et al. (1989)
Nuc. Acids
Res. 17:477-508). Translation stop codons can also be modified to reflect host
preference.
For example, preferred stop codons for S. cerevisiae and mammals are UAA and
UGA
respectively. The preferred stop codon for monocotyledonous plants is UGA,
whereas
insects and E. coli prefer to use UAA as the stop codon (see, e.g., Dalphin.
M.E. et al.
(1996) Nuc. Acids Res. 24:216-218). The arrangement of codons in context to
other
codons also can influence biological properties of a nucleic acid sequences,
and
modifications of nucleic acids to provide a codon context arrangement common
for a
particular host also is contemplated by the inventors. Thus, a nucleic acid
sequence of the
invention can comprise a codon optimized nucleotide sequence, i.e., codon
frequency
optimized and/or codon pair (i.e., codon context) optimized for a particular
species (e.g.,
the polypeptide can be expressed from a polynucleotide sequence optimized for
expression
in humans by replacement of "rare" human codons based on codon frequency, or
codon
context, such as by using techniques such as those described in Buckingham et
al. (1994)
Biochimie 76(5):351-54 and U.S. Patent Nos. 5,082,767. 5,786,464, and
6,114,148).
Nucleic acids of the invention can be modified by truncation or one or more
residues of the C-terminus portion of the sequence. Additional, a variety of
stop or
termination codons may be included at the end of the nucleotide sequence as
further
discussed below.
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One or more nucleic acids of the invention may be included in a vector, cell,
or
host environment in which a coding nucleotide sequence of the invention is a
heterologous
gene.
Polynucleotides of the invention include polynucleotide sequences that encode
any
polypeptide of the invention (or polypeptide fragment thereof) which binds
CD80 and/or
CD86 and/or suppresses an immune response, polynucleotides that hybridize
under at least
stringent conditions to one or more such polynucleotide sequences described
herein,
polynucleotide sequences complementary to any such polynucleotide sequences,
and
variants, analogs, and homologue derivatives of all of the above. A coding
sequence
refers to a nucleotide sequence encodes a particular polypeptide or a domain,
subsequence,
region, or fragment of said polypeptide. A coding sequence may code for a
mutant
CTLA-4 polypeptide or fragment thereof having a functional property, such as
the ability
to bind CD80 and/or CD86 and/or inhibit or suppress an immune response. A
nucleic acid
of the invention may comprise a respective coding sequence of a mutant CTLA-4
polypeptide of the invention, and variants, analogs, and homologue derivatives
thereof.
Nucleic acids of the invention can also be found in combination with typical
compositional formulations of nucleic acids, including in the presence of
carriers, buffers,
adjuvants, excipients, diluents, and the like, as are known to those of
ordinary skill in the
art.
Unless otherwise indicated, a particular nucleic acid sequence described
herein
also implicitly encompasses conservatively modified variants thereof (e.g.,
degenerate
codon substitutions) and complementary sequences and as well as the sequence
explicitly
indicated. Specifically, degenerate codon substitutions may be achieved by
generating
sequences in which the third position of one or more selected (or all) codons
is substituted
with mixed-base and/or deoxyinosine residues (Batzer et al. (1991) Nucl. Acid
Res.
19:5081; Ohtsuka et al. (1985) J. Biol. Chem. 260:2605-2608; Cassol et al.
(1992);
Rossolini et al. (1994) Mol. Cell. Probes 8:91-98).
Nucleic Acid Hybridization
As noted above, the invention includes nucleic acids that hybridize to a
target
nucleic acid of the invention, such as, e.g., a polynucleotide selected from
the group
consisting of SEQ ID NOS:80-158, 201-204, 223, and 224 or a complementary
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polynucleotide sequence thereof, wherein hybridization is over substantially
the entire
length of the target nucleic acid. The hybridizing nucleic acid may hybridize
to a
nucleotide sequence of the invention, such as, e.g., that of SEQ ID NO:80,
under at least
stringent conditions or under at least high stringency conditions. Moderately
stringent,
stringent, and highly stringent hybridization conditions for nucleic acid
hybridization
experiments are known. Examples of factors that can be combined to achieve
such levels
of stringency are briefly discussed herein.
Nucleic acids "hybridize" when they associate, typically in solution. Nucleic
acids
hybridize due to a variety of well-characterized physico-chemical forces, such
as hydrogen
bonding, solvent exclusion, base stacking and the like. An extensive guide to
the
hybridization of nucleic acids is found in P. Tijssen (1993) LABORATORY
TECHNIQUES IN
BIOCHEMISTRY AND MOLECULAR BIOLOGY--HYBRIDIZATION WITH NUCLEIC ACID PROBES,
vol. 24, part I, chapter 2, "Overview of principles of hybridization and the
strategy of
nucleic acid probe assays," (Elsevier, NY) (hereinafter "Tijssen"), as well as
in Ausubel,
supra, flames and Higgins (1995) GENE PROBES 1, IRL Press at Oxford University
Press,
Oxford, England (Hames and Higgins 1) and Hames and Higgins (1995) GENE PROBES
2,
IRL Press at Oxford University Press, Oxford, England (Flames and Higgins 2)
provide
details on the synthesis, labeling, detection and quantification of DNA and
RNA,
including oligonucleotides.
An indication that two nucleic acid sequences are substantially identical is
that the
two molecules hybridize to each other under at least stringent conditions. The
phrase
"hybridizing specifically to," refers to the binding, duplexing, or
hybridizing of a molecule
only to a particular nucleotide sequence under stringent conditions when that
sequence is
present in a complex mixture (e.g., total cellular) DNA or RNA. "Bind(s)
substantially"
refers to complementary hybridization between a probe nucleic acid and a
target nucleic
acid and embraces minor mismatches that can be accommodated by reducing the
stringency of the hybridization media to achieve the desired detection of the
target
polynucleotide sequence.
"Stringent hybridization wash conditions" and "stringent hybridization
conditions"
in the context of nucleic acid hybridization experiments, such as Southern and
northern
hybridizations, are sequence dependent, and are different under different
environmental
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parameters. An extensive guide to hybridization of nucleic acids is found in
Tijssen
(1993), supra, and in Hames and Higgins 1 and Hames and Higgins 2, supra.
Generally, high stringency conditions are selected such that hybridization
occurs at
about 5 C or less than the thermal melting. point (T.) for the specific
sequence at a
defined ionic strength and pH. The T. is the temperature (under defined ionic
strength
and pH) at which 50% of the test sequence hybridizes to a perfectly matched
probe. In
other words, the T. indicates the temperature at which the nucleic acid duplex
is 50%
denatured under the given conditions and its represents a direct measure of
the stability of
the nucleic acid hybrid. Thus, the T. corresponds to the temperature
corresponding to the
midpoint in transition from helix to random coil; it depends on length,
nucleotide
composition, and ionic strength for long stretches of nucleotides. Typically,
under
"stringent conditions," a probe will hybridize to its target subsequence, but
to no other
sequences. "Very stringent conditions" are selected to be equal to the T,õ for
a particular
probe.
The T., of a DNA-DNA duplex can be estimated using equation (1): T. ( C) =
81.5 C + 16.6 (logioM) + 0.41 (%G + C) ¨ 0.72 (%f) ¨ 500/n, where M is the
molarity of
the monovalent cations (usually Na+), (%G + C) is the percentage of guanosine
(G) and
cytosine (C) nucleotides, (%f) is the percentage of formalize and n is the
number of
nucleotide bases (i.e., length) of the hybrid. See Rapley, R. and Walker, J.M.
eds.,
MOLECULAR BIOMETHODS HANDBOOK (1998), Humana Press, Inc. (hereinafter Rapley
and
Walker), Tijssen (1993), supra. The T. of an RNA-DNA duplex can be estimated
using
equation (2): T., ( C) = 79.8 C + 18.5 (logioM) + 0.58 (%G + C) ¨ 11.8(%G +
C)2 ¨0.56
(%f) ¨ 820/n. where M is the molarity of the monovalent cations (usually Na+),
(%G + C)
is the percentage of guanosine (G) and cytosine (C ) nucleotides, (%f) is the
percentage of
formamide and n is the number of nucleotide bases (i.e., length) of the
hybrid. Id.
Equations 1 and 2 above are typically accurate only for hybrid duplexes longer
than about
100-200 nucleotides. Id. The T. of nucleic acid sequences shorter than 50
nucleotides
can be calculated as follows: T., ( C) = 4(G + C) + 2(A + T), where A
(adenine), C, T
(thymine), and G are the numbers of the corresponding nucleotides.
In general, non-hybridized nucleic acid material is removed by a series of
washes,
the stringency of which can be adjusted depending upon the desired results, in
conducting
hybridization analysis. Low stringency washing conditions (e.g., using higher
salt and
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lower temperature) increase sensitivity, but can product nonspecific
hybridization signals
and high background signals. Higher stringency conditions (e.g., using lower
salt and
higher temperature that is closer to the hybridization temperature) lower the
background
signal, typically with only the specific signal remaining. Addition useful
guidance
concerning such hybridization techniques is provided in, e.g., Rapley and
Walker, supra
(in particular, with respect to such hybridization experiments, part I,
chapter 2, "Overview
of principles of hybridization and the strategy of nucleic acid probe
assays"), Elsevier,
New York, as well as in Ausubel, supra, Sambrook, supra, Watson, supra, Hames
and
Higgins (1995) GENE PROBES 1, IRL Press at Oxford Univ. Press, Oxford,
England, and
Hames and Higgins (1995) GENE PROBES 2, IRL Press, Oxford Univ. Press, Oxford,
England.
Exemplary stringent (or regular stringency) conditions for analysis of at
least two
nucleic acids comprising at least 100 nucleotides include incubation in a
solution or on a
filter in a Southern or northern blot comprises 50% formalin (or formamide)
with 1
milligram (mg) of heparin at 42 C, with the hybridization being carried out
overnight. A
regular stringency wash can be carried out using, e.g., a solution comprising
0.2x SSC
wash at about 65 C for about 15 minutes (see Sambrook, supra, for a
description of SSC
buffer). Often, the regular stringency wash is preceded by a low stringency
wash to
remove background probe signal. A low stringency wash can be carried out in,
for
example, a solution comprising 2x SSC at about 40 C for about 15 minutes. A
highly
stringent wash can be carried out using a solution comprising 0.15 M NaC1 at
about 72 C
for about 15 minutes. An example medium (regular) stringency wash, less
stringent than
the regular stringency wash described above, for a duplex of, e.g., more than
100
nucleotides, can be carried out in a solution comprising lx SSC at 45 C for 15
minutes.
An example low stringency wash for a duplex of, e.g., more than 100
nucleotides, is
carried out in a solution of 4-6x SSC at 40 C for 15 minutes. For short probes
(e.g., about
10-50 nucleotides), stringent conditions typically involve salt concentrations
of less than
about 1.0 M Na + ion, typically about 0.01 to 1.0 M Na + ion concentration (or
other salts) at
pH 7.0 to 8.3, and the temperature is typically at least about 30 C. Stringent
conditions
can also be achieved with the addition of destabilizing agents such as
formamide.
Exemplary moderate stringency conditions include overnight incubation at 37 C
in
a solution comprising 20% formalin (or formamide), 0.5x SSC, 50 mM sodium
phosphate
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(pH 7.6), 5x Denhardt's solution, 10% dextran sulfate, and 20 mg/ml denatured
sheared
salmon sperm DNA, followed by washing the filters in lx SSC at about 37-50 C,
or
substantially similar conditions, e.g., the moderately stringent conditions
described in
Sambrook, supra, and/or Ausubel, supra.
High stringency conditions are conditions that use, for example, (1) low ionic
strength and high temperature for washing, such as 0.015 M sodium
chloride/0.0015 M
sodium citrate/0.1% sodium dodecyl sulfate (SDS) at 50 C, (2) employ a
denaturing agent
during hybridization, such as formamide, for example, 50% (v/v) formamide with
0.1%
bovine serum albumin (BSA)/0.1% Fico11/0.1% polyvinylpyrrolidone (PVP)/50 mM
sodium phosphate buffer at pH 6.5 with 750 mM sodium chloride, 75 mM sodium
citrate
at 42 C, or (3) employ 50% formamide, 5x SSC (0.75 M NaCl, 0.075 M sodium
citrate),
50 mM sodium phosphate (pH 6.8), 0.1% sodium pyrophosphate, 5x Denhardt's
solution,
sonicated salmon sperm DNA (5014/m1), 0.1% SDS, and 10% dextran sulfate at 42
C,
with washes at (i) 42 C in 0.2x SSC, (ii) at 55 C in 50% formamide and (iii)
at 55 C in
0.1x SSC (preferably in combination with EDTA).
In general, a signal to noise ratio of 2x or 2.5x-5x (or higher) than that
observed for
an unrelated probe in the particular hybridization assay indicates detection
of a specific
hybridization. Detection of at least stringent hybridization between two
sequences in the
context of the present invention indicates relatively strong structural
similarity or
homology to, e.g., the nucleic acids of the present invention.
As noted, "highly stringent" conditions are selected to be about 5 C or less
lower
than the thermal melting point (Tm) for the specific sequence at a defined
ionic strength
and pH. Target sequences that are closely related or identical to the
nucleotide sequence
of interest (e.g., "probe") can be identified under highly stringency
conditions. Lower
stringency conditions are appropriate for sequences that are less
complementary. See, e.g.,
Rapley and Walker; Sambrook, all supra.
Comparative hybridization can be used to identify nucleic acids of the
invention,
and this comparative hybridization method is a preferred method of
distinguishing nucleic
acids of the invention. Detection of highly stringent hybridization between
two nucleotide
sequences in the context of the present invention indicates relatively strong
structural
similarity/homology to, e.g., the nucleic acids provided in the sequence
listing herein.
Highly stringent hybridization between two nucleotide sequences demonstrates a
degree of
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similarity or homology of structure, nucleotide base composition, arrangement
or order
that is greater than that detected by stringent hybridization conditions. In
particular,
detection of highly stringent hybridization in the context of the present
invention indicates
strong structural similarity or structural homology (e.g., nucleotide
structure, base
composition, arrangement or order) to, e.g., the nucleic acids provided in the
sequence
listing herein. For example, it is desirable to identify test nucleic acids
that hybridize to
the exemplar nucleic acids herein under stringent conditions.
Thus, one measure of stringent hybridization is the ability to hybridize to a
nucleic
acid of the invention (e.g., a nucleic acid comprising a polynucleotide
sequence selected
from the group consisting of SEQ ID NOS:80-158, 201-204, 223, and 224, or a
complementary polynucleotide sequence thereof) under highly stringent
conditions (or
very stringent conditions, or ultra-high stringency hybridization conditions,
or ultra-ultra
high stringency hybridization conditions). Stringent hybridization (including,
e.g., highly
stringent, ultra-high stringency, or ultra-ultra high stringency hybridization
conditions) and
wash conditions can easily be determined empirically for any test nucleic
acid.
For example, in determining highly stringent hybridization and wash
conditions,
the hybridization and wash conditions are gradually increased (e.g., by
increasing
temperature, decreasing salt concentration, increasing detergent concentration
and/or
increasing the concentration of organic solvents, such as formalin, in the
hybridization or
wash), until a selected set of criteria is met. For example, the hybridization
and wash
conditions are gradually increased until a probe comprising one or more
nucleic acid
sequences selected from the group consisting of SEQ ID NOS:80-158, 201-204,
223, and
224 and complementary polynucleotide sequences thereof, binds to a perfectly
matched
complementary target (again, a nucleic acid comprising at least one nucleic
acid sequences
selected from the group consisting of SEQ ID NOS:80-158, 201-204, 223, and 224
or
complementary polynucleotide sequences thereof), with a signal to noise ratio
that is at
least 2.5x, and optionally 5x or more as high as that observed for
hybridization of the
probe to an unmatched target. The unmatched target may comprise a nucleic acid
corresponding to, e.g., a CTLA-4 polypeptide-encoding nucleic acid sequence.
Usually, the hybridization analysis is carried out under hybridization
conditions
selected such that a nucleic acid comprising a sequence that is perfectly
complementary to
the a disclosed reference (or known) nucleotide sequence (e.g., SEQ ID NO:80)
hybridizes
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with the recombinant antigen-encoding sequence (e.g., a nucleotide sequence
variant of
the nucleic acid sequence of SEQ ID NO:80) with at least about 5, 7, or 10
times higher
signal-to-noise ratio than is observed in the hybridization of the perfectly
complementary
nucleic acid to a nucleic acid that comprises a nucleotide sequence that is at
least about 80
or 90% identical to the reference nucleic acid. Such conditions can be
considered
indicative for specific hybridization.
The above-described hybridization conditions can be adjusted, or alternative
hybridization conditions selected, to achieve any desired level of stringency
in selection of
a hybridizing nucleic acid sequence. For example, the above-described highly
stringent
hybridization and wash conditions can be gradually increased (e.g., by
increasing
temperature, decreasing salt concentration, increasing detergent concentration
and/or
increasing the concentration of organic solvents, such as formalin, in the
hybridization or
wash), until a selected set of criteria are met. For example, the
hybridization and wash
conditions can be gradually increased until a desired probe, binds to a
matched
complementary target, with a signal-to-noise ratio that is at least about
2.5x, and
optionally at least about 5x (e.g., about 10x, about 20x, about 50x, about
100x, or even
about 500x), as high as the signal-to-noise ration observed from hybridization
of the probe
to a nucleic acid not of the invention, such as a nucleic acid encoding WT
CTLA-4 ECD
polypeptide.
Making and Modifying Nucleic Acids
Nucleic acids of the invention can be obtained and/or generated by application
of
any suitable synthesis, manipulation, and/or isolation techniques, or
combinations thereof.
Exemplary procedures are described infra. For example, polynucleotides of the
invention
are typically produced through standard nucleic acid synthesis techniques,
such as solid-
phase synthesis techniques known in the art. In such techniques, fragments of
up to about
100 bases usually are individually synthesized, then joined (e.g., by
enzymatic or chemical
ligation methods, or polymerase mediated recombination methods) to form
essentially any
desired continuous nucleic acid sequence. The synthesis of the nucleic acids
of the
invention can be also facilitated (or alternatively accomplished), by chemical
synthesis
using, e.g., the classical phosphoramidite method, which is described in,
e.g., Beaucage et
al. (1981) Tetrahedron Letters 22:1859-69, or the method described by Matthes
et al.
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(1984) EMBO J. 3:801-05, e.g., as is typically practiced in automated
synthetic methods.
The nucleic acid of the invention also can be produced by use of an automatic
DNA
synthesizer. Other techniques for synthesizing nucleic acids and related
principles are
described in, e.g., Itakura et al., Annu. Rev. Biochem. 53:323 (1984), Itakura
et al.,
Science 198:1056 (1984), and Ike et al., Nucl. Acid Res. 11:477 (1983).
Conveniently, custom made nucleic acids can be ordered from a variety of
commercial sources, such as The Midland Certified Reagent Company
(mcrc@oligos.com), the Great American Gene Company (worldwide website address
genco.com), ExpressGen Inc. (worldwide website address expressgen.com), Operon
Technologies Inc. (Alameda, CA). Similarly, custom peptides and antibodies can
be
custom ordered from any of a variety of sources. e.g., PeptidoGenic
(pkim@ccnet.com),
HTI Bio-products, Inc. (worldwide website address htibio.com), and BMA
Biomedicals
Ltd. (U.K.), Bio.Synthesis, Inc.
Certain nucleotides of the invention may also be obtained by screening cDNA
libraries using oligonucleotide probes that can hybridize to or PCR-amplify
polynucleotides which encode the polypeptides of the invention. Procedures for
screening
and isolating cDNA clones and PCR amplification procedures are well known to
those of
skill in the art; exemplary procedures are described infra (see, e.g.,
procedures described
in the Examples below). Such techniques are described in, e.g., Berger and
Kimmel,
"Guide to Molecular Cloning Techniques," in Methods in Enzymol. Vol. 152,
Acad.
Press, Inc., San Diego, CA ("Berger"); Sambrook, supra; and Ausubel, supra.
Some
nucleic acids of the invention can be obtained by altering a naturally
occurring backbone,
e.g., by mutagenesis, in vitro recombination (e.g., shuffling), or
oligonucleotide
recombination. In other cases, such polynucleotides can be made in silico or
through
oligonucleotide recombination methods as described in the references cited
herein.
Recombinant DNA techniques useful in modification of nucleic acids are well
known in the art (e.g., restriction endonuclease digestion, ligation, reverse
transcription
and cDNA production. and PCR). Useful recombinant DNA technology techniques
and
principles related thereto are provided in, e.g., Mulligan (1993) Science
260:926-932,
Friedman (1991) THERAPY FOR GENETIC DISEASES, Oxford University Press, Ibanez
et al.
(1991) EMBO J. 10:2105-10, Ibanez et al. (1992) Cell 69:329-41 (1992), and
U.S. Patent
Nos. 4,440,859, 4,530,901, 4,582,800, 4,677,063, 4,678,751, 4.704,362,
4,710,463,
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4,757,006, 4,766,075, and 4,810,648, and are more particularly described in
Sambrook et
al. (1989) MOLECULAR CLONING: A LABORATORY MANUAL, Cold Spring Harbor Press,
and the third edition thereof (2001), Ausubel et al. (1994-1999), Current
Protocols in
Molecular Biology, Wiley Interscience Publishers (with Greene Publishing
Associates for
some editions), Berger, supra, and Watson, supra.
Modified Coding Sequences
Where appropriate, nucleic acids of the invention can be modified to increase
or
enhance expression in a particular host by modification of the sequence with
respect to
codon usage and/or codon context, given the particular host(s) in which
expression of the
nucleic acid is desired. Codons that are utilized most often in a particular
host are called
optimal codons, and those not utilized very often are classified as rare or
low-usage
codons (see. e.g., Zhang, S. P. et al. (1991) Gene 105:61-72). Codons can be
substituted
to reflect the preferred codon usage of the host, a process called "codon
optimization" or
"controlling for species codon bias."
Optimized coding sequence comprising codons preferred by a particular
prokaryotic or eukaryotic host can be used to increase the rate of translation
or to produce
recombinant RNA transcripts having desirable properties, such as a longer half-
life, as
compared with transcripts produced from a non-optimized sequence. Techniques
for
producing codon-optimized sequences are known (see, e.g., Murray, E. et al.
(1989) Nucl.
Acids Res. 17:477-508). Translation stop codons can also be modified to
reflect host
preference. For example, preferred stop codons for S. cerevisiae and mammals
are UAA
and UGA respectively. The preferred stop codon for monocotyledonous plants is
UGA,
whereas insects and E. coli prefer to use UAA as the stop codon (see, e.g.,
Dalphin, M.E.
et al. (1996) Nucl. Acids Res. 24:216-218, for discussion). The arrangement of
codons in
context to other codons also can influence biological properties of a nucleic
acid
sequences, and modifications of nucleic acids to provide a codon context
arrangement
common for a particular host also is contemplated by the inventors. Thus, a
nucleic acid
sequence of the invention can comprise a codon optimized nucleotide sequence,
i.e.,
codon frequency optimized and/or codon pair (i.e., codon context) optimized
for a
particular species (e.g., the polypeptide can be expressed from a
polynucleotide sequence
optimized for expression in humans by replacement of "rare" human codons based
on
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codon frequency, or codon context, such as by using techniques such as those
described in
Buckingham et al. (1994) Biochimie 76(5):351-54 and U.S. Patent Nos.
5,082,767,
5,786,464, and 6,114,148). For example, the invention provides a nucleic acid
comprising
a nucleotide sequence variant of SEQ ID NO:80, wherein the nucleotide sequence
variant
differs from the nucleotide sequence of SEQ ID NO:80 by the substitution of
"rare"
codons for a particular host with codons commonly expressed in the host, which
codons
encode the same amino acid residue as the substituted "rare" codons in SEQ ID
NO:80.
VECTORS, VECTOR COMPONENTS. AND EXPRESSION SYSTEMS
The present invention also includes recombinant constructs comprising one or
more of the nucleic acids of the invention as broadly described above. Such
constructs
may comprise a vector, such as a plasmid, a cosmid, a phage, a virus, a viral
particle, a
virus-like particle, a bacterial artificial chromosome (BAC), a yeast
artificial chromosome
(YAC), or the like, or a non-replicating vector, such as a liposome, naked or
conjugated
DNA, DNA-microparticle, into which at least one nucleic acid sequence of the
invention
has been inserted, in a forward or reverse orientation. In a particular aspect
of this
embodiment, the construct further comprises one or more regulatory sequences,
including,
for example, a promoter, operably linked to a nucleic acid sequence of the
invention (e.g.,
nucleic acid encoding an isolated or recombinant mutant CTLA-4 ECD polypeptide
or
dimeric or monomeric mutant CTLA-4-Ig). Large numbers of suitable vectors and
promoters are known to those of skill in the art and are commercially
available. In some
instances, a vector, such as, e.g., a virus or virus-like particle, may also
or alternatively
include one or more polypeptides of the invention such as, e.g., incorporated
into the coat
of the virus or virus-like particle. Vectors can be useful as delivery agents
for the delivery
or administration to a subject of exogenous genes or proteins. Vectors of the
present
invention, including those described herein, are useful as delivery agents for
the delivery
or administration of nucleic acids and/or polypeptides of the invention.
General texts that describe molecular biological techniques useful herein,
including
the use of vectors, promoters, and many other relevant topics, include Berger,
supra,
Sambrook (1989), supra, and Ausubel, supra. Examples of techniques sufficient
to direct
persons of skill through in vitro amplification methods, including the
polymerase chain
reaction (PCR) the ligase chain reaction (LCR), QD-replicase amplification and
other
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RNA polymerase mediated techniques (e.g., NASBA), e.g., for the production of
the
homologous nucleic acids of the invention are found in Berger. Sambrook, and
Ausubel,
all supra, as well as Mullis et al. (1987) U.S. Patent No. 4,683,202; PCR
Protocols: A
Guide to Methods and Applications (Innis et al., eds.) Academic Press Inc. San
Diego, CA
(1990) ("Innis"); Arnheim & Levinson (October 1, 1990) C&EN 36-47; The Journal
Of
NIH Research (1991) 3:81-94: (Kwoh et al. (1989) Proc. Natl. Acad. Sci. USA
86:1173-
1177; Guatelli et al. (1990) Proc. Natl. Acad. Sci. USA 87:1874-1878; Lomeli
et al.
(1989) J. Clin. Chem. 35:1826-1831; Landegren et al. (1988) Science 241:1077-
1080; Van
Brunt (1990) Biotechnology 8:291-294; Wu and Wallace (1989) Gene 4:560-569;
Barringer et al. (1990) Gene 89:117-122, and Sooknanan and Malek (1995)
Biotechnology
13:563-564.
PCR generally refers to a procedure wherein minute amounts of a specific piece
of
nucleic acid (e.g., RNA or DNA) are amplified by methods well known in the art
(see,
e.g., U.S. Pat. No. 4,683.195 and the other references cited above).
Generally, sequence
information from the ends of the region of interest or beyond is used for
design of
oligonucleotide primers. Such primers will be identical or similar in sequence
to the
opposite strands of the template to be amplified. The 5' terminal nucleotides
of the
opposite strands may coincide with the ends of the amplified material. PCR may
be used
to amplify specific RNA or specific DNA sequences, recombinant DNA or RNA
sequences, DNA and RNA sequences from total genomic DNA, and cDNA transcribed
from total cellular RNA, bacteriophage or plasmid sequences, etc. PCR is one
example,
but not the only example, of a nucleic acid polymerase reaction method for
amplifying a
nucleic acid test sample comprising the use of another (e.g., known) nucleic
acid as a
primer. Improved methods of cloning in vitro amplified nucleic acids are
described in
Wallace et al., U.S. Pat. No. 5.426,039. Improved methods of amplifying large
nucleic
acids by PCR are summarized in Cheng et al. (1994) Nature 369:684 685 and the
references cited therein, in which PCR amplicons of up to 40 kilobases (kb)
are generated.
One of skill will appreciate that essentially any RNA can be converted into a
double-
stranded DNA suitable for restriction digestion, PCR expansion and sequencing
using
reverse transcriptase and a polymerase. See Ausubel, Sambrook, and Berger, all
supra.
The nucleic acids of the present invention can be incorporated into any one of
a
variety of vectors, e.g., expression vectors, for expressing a polypeptide,
including, e.g., a
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polypeptide of the invention. Expression vectors compatible with prokaryotic
host cells
may be used; such prokaryotic expression vectors are known in the art and
commercially
available. Such vectors include, but are not limited to, e.g., BLUESCRIPT
vector
(Stratagene), T7 expression vector (Invitrogen), pET vector (Novagen), and
similar
prokaryotic vectors.
Expression vectors compatible with eukaryotic host cells may alternatively be
used; such eukaryotic expression vectors are known in the art and commercially
available.
Such vectors include, but are not limited to, e.g., pCMV vectors (e.g.,
Invitrogen), pIRES
vector (Clontech), pSG5 vector (Stratagene), pCDNA3.1 (Invitrogen Life
Technologies),
pCDNA3 (Invitrogen Life Technologies), Ubiquitous Chromatin Opening Element
(UCOE) expression vector (Millipore), and similar eukaryotic expression
vectors. The
UCOETm vector is typically used for protein production in mammalian cells
(e.g., CHO
cells). According to Millipore, the UCOE114 expression technology thwarts
transgene
silencing and provides stable high-level gene expression without respect to
the site of
chromosomal integration. See Millipore website at worldwide web address
millipore.com.
An exemplary UCOE expression vector into which, for example, a nucleic acid of
the
invention can be incorporated is the UCOE expression vector named CET1019AS-
puro-
Seel, which is available for licensing from Millipore. Information about the
UCOE
expression vector CET1019AS-puro-SceI can be found in, e.g., John Wynne,
"UCOETm
Technology Maximizes Protein Expression," BioProcess International 4(7):104-
105
(July/August 2006) (RP1725EN00) (available at worldwide web address
millipore.com/bibliography/techl/rp1725en00); additional information about
this vector
and licensing of this vector from Millipore can be found the Millipore
website, including
at, e.g., worldwide web addresses millipore.com/company/cp3/ucoe_licensing and
millipore.com/techpublications/techlips1013en00. Thus, for example, a DNA
sequence
encoding a mutant CTLA-4 ECD (e.g., SEQ ID NO:36 or SEQ ID NO:50) fused to a
DNA
sequence encoding an IgG2 Fc polypeptide (e.g., SEQ ID NO:184). resulting in
the DNA
sequence of SEQ ID NO:201 is inserted into a UCOE CET1019AS vector (Millipore)
and
the resulting DNA plasmid can be used for transfections of host cells.
Expression vectors include chromosomal, nonchromosomal and synthetic DNA
sequences, e.g., derivatives of SV40, bacterial vectors (e.g., S. typhimurium,
S. typhi, S.
flexneri, Listeria monocytogenes, B. anthracis); plasmids; bacterial plasmids;
phage DNA;
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baculovirus; yeast plasmids; vectors derived from combinations of plasmids and
phage
DNA; viral DNA or RNA vectors, including, e.g., vaccinia virus, adeno-
associated virus
(AAV), adenovirus, Semliki-Forest virus (e.g., Notka et al., Biol. Chem.
380:341-52
(1999), pox virus (e.g., MVA), alphavirus (e.g., Venezuelan equine
encephalitis virus
(VEE), Western equine encephalitis virus (WEE), Eastern equine encephalitis
virus
(EEE)), vesicular stomatitis virus (VSV), fowl pox virus, pseudorabies, herpes
simplex
viruses, retroviruses, and many others. Any vector that transduces genetic
material into a
cell, and, if replication is desired, which is replicable and viable in the
relevant host can be
used. Viral and bacterial vectors serving as delivery vehicles can be
attenuated;
attenuation should be sufficient to decrease if not eliminate induction of
undesirable
disease symptoms. Figure 1 is a schematic diagram of an exemplary plasmid
expression
vector pCDNA mutant CTLA-4-Ig which encodes a mutant CTLA-4-Ig of the
invention.
Additional details regarding suitable expression vectors are provided below,
including in
the Examples.
A vector of the invention comprising a nucleic acid sequence of the invention
as
described herein, as well as an appropriate promoter or control sequence, can
be employed
to transform an appropriate host to permit the host to express the protein.
Examples of
appropriate expression hosts include: bacterial cells, such as E. coli,
Streptomyces, and
Salmonella typhimurium; fungal cells, such as Saccharomyces cerevisiae, Pichia
pastoris,
and Neurospora crassa; insect cells such as Drosophila and Spodoptera
frugiperda;
mammalian cells, such as Chinese Hamster Ovary (CHO) (e.g., CHO-K1), COS
(e.g.,
COS-1, COS-7), baby hamster kidney (BHK), and Human Embryonic Kidney (HEK)
(e.g., HEK 293), Bowes melanoma cells, and plant cells. It is understood that
not all cells
or cell lines need to be capable of producing fully functional polypeptides of
the invention
or fragments thereof. The invention is not limited by the host cells employed.
Additional
details regarding suitable host cells are provided below.
In bacterial systems, a number of expression vectors may be selected depending
upon the use intended for the desired polypeptide or fragment thereof. For
example, when
large quantities of a particular polypeptide or fragments thereof are needed
for the
induction of antibodies, vectors which direct high level expression of fusion
proteins that
are readily purified may be desirable. Such vectors include, but are not
limited to,
multifunctional E. coli cloning and expression vectors such as BLUESCRIPT
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(Stratagene), in which nucleotide coding sequence of interest (e.g.,
nucleotide sequence
encoding a recombinant mutant CTLA-4-Ig) may be ligated into the vector in-
frame with
sequences for the amino-terminal Met and the subsequent 7 residues of beta-
galactosidase
so that a hybrid protein is produced; pIN vectors (Van Heeke & Schuster (1989)
J. Biol.
Chem. 264:5503-5509); pET vectors (Novagen, Madison WI); and the like.
Similarly, in the yeast Saccharomyces cerevisiae, a number of vectors
comprising
constitutive or inducible promoters such as alpha factor, alcohol oxidase, and
PGH may be
used for production of the polypeptides of the invention. For reviews, see
Ausubel, supra,
Berger, supra, and Grant et al. (1987) Meth. Enzymol. 153:516-544.
In mammalian host cells, a number of expression systems, such as viral-based
systems, may be utilized. In cases where an adenovirus is used as an
expression vector, a
coding sequence is optionally ligated into an adenovirus
transcription/translation complex
consisting of the late promoter and tripartite leader sequence. Insertion in a
nonessential
El or E3 region of the viral genome results in a viable virus capable of
expressing a
polypeptide of interest in infected host cells (Logan and Shenk (1984) Proc.
Natl. Acad.
Sci. USA 81:3655-3659). In addition, transcription enhancers, such as the Rous
sarcoma
virus (RSV) enhancer, are used to increase expression in mammalian host cells.
A vector, e.g., expression vector, or polynucleotide of the invention can
comprise
one or more expression control sequences. An expression control sequence is
typically
associated with and/or operably linked to a nucleic acid sequence of the
invention, such as
a nucleic acid encoding a recombinant mutant CTLA-4 ECD polypeptide or
recombinant
mutant CTLA-4- Ig fusion protein. An expression control sequence is typically
a
nucleotide sequence that promotes, enhances, or controls expression (typically
transcription) of another nucleotide sequence. Suitable expression control
sequences that
may be employed include a promoter, including a constitutive promoter,
inducible
promoter, and/or repressible promoter, an enhancer for amplifying expression,
an initiation
sequence, a termination translation sequence, a splicing control sequence, and
the like.
When a nucleic acid of the invention is included in a vector, the nucleic acid
is
typically operatively linked to an appropriate transcription control sequence
(promoter) to
direct mRNA synthesis. Promoters exert a particularly important impact on the
level of
recombinant polypeptide expression. Any suitable promoter can be utilized.
Examples of
suitable promoters include the cytomegalovirus (CMV) promoter with or without
the first
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intron (intron A), the HIV long terminal repeat promoter, the phosphoglycerate
kinase
(PGK) promoter, Rous sarcoma virus (RSV) promoters, such as RSV long terminal
repeat
(LTR) promoters, SV40 promoters, mouse mammary tumor virus (MMTV) promoters,
HSV promoters, such as the Lap2 promoter or the herpes thymidine kinase
promoter (as
described in, e.g., Wagner et al. (1981) Proc. Natl. Acad. Sci. 78:144-145),
promoters
derived from SV40 or Epstein Barr virus, adeno-associated viral (AAV)
promoters, such
as the p5 promoter, metallothionein promoters (e.g., the sheep metallothionein
promoter or
the mouse metallothionein promoter (see, e.g.. Palmiter et al. (1983) Science
222:809-
814), the human ubiquitin C promoter, E. coli promoters, such as the lac and
trp
promoters, phaf,re lambda PL promoter, and other promoters known to control
expression
of genes in prokaryotic or eukaryotic cells (either directly in the cell or in
viruses which
infect the cell). Promoters that exhibit strong constitutive baseline
expression in
mammals, particularly humans, such as CMV promoters, such as the CMV immediate-
early promoter (described in, e.g., U.S. Patent Nos. 5,168,062, 5,385,839,
5,688,688, and
5,658,759), and promoters having substantial sequence identity with such CMV
promoters, can be employed. Recombinant promoters having enhanced properties,
such as
in 1nel Pat. Publ. No. WO 02/00897, may also be used.
A promoter that is operably linked to a nucleic acid of the invention for
expression
of the nucleic acid can have any suitable mechanism of action. Thus, the
promoter can be,
for example, an "inducible" promoter, (e.g., a growth hormone promoter,
metallothionein
promoter, heat shock protein promoter, ElB promoter, hypoxia induced promoter,
radiation inducible promoter, or adenoviral MLP promoter and tripartite
leader), an
inducible-repressible promoter, a developmental stage-related promoter (e.g.,
a globin
gene promoter), or a tissue specific promoter (e.2., a smooth muscle cell a-
actin promoter,
myosin light-chain lA promoter, or vascular endothelial cadherin promoter).
Suitable
inducible promoters include ecdysone and ecdysone-analog-inducible promoters.
Ecdysone-analog-inducible promoters are commercially available, e.g., through
Stratagene
(La Jolla, CA). If desired, a nucleic acid of the invention can be induced by
using an
inducible on- and off-gene expression system. Examples of such on- and off-
gene
expression systems include the Tet-OnTm Gene Expression System and Tet-Off'
Gene
Expression System, respectively (Clontech, Palo Alto, CA; see, e.g., Clontech
Catalog
2000, pg. 110-111 for a detailed description of each such system). The
inducible promoter
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can be any promoter that is up- and/or downreaulated in response to an
appropriate signal.
Additional inducible promoters include arabinose-inducible promoters, a
steroid-inducible
promoters (e.g., a glucocorticoid-inducible promoters), as well as pH, stress,
and heat-
inducible promoters.
The promoter can be, and often is, a host-native promoter, or a promoter
derived
from a virus that infects a particular host (e.g., a human beta actin
promoter, human EFloc
promoter, or a promoter derived from a human AAV operably linked to the
nucleic acid of
interest), particularly where strict avoidance of gene expression silencing
due to host
immunological reactions to sequences that are not regularly present in the
host is of
concern. A bi-directional promoter system (as described in, e.g., U.S.
5,017,478) linked to
multiple nucleotide sequences of interest can also be utilized.
Other suitable promoters and principles related to the selection, use, and
construction of suitable promoters are provided in, e.g., Werner (1999) Mamm
Genome
10(2):168-75, Walther et al. (1996) J. Mol. Med. 74(7):379-92. Novina (1996)
Trends
Genet. 12(9):351-55, Hart (1996) Semin. Oncol. 23(1):154-58, Gralla (1996)
Curr. Opin.
Genet. Dev. 6(5):526-30, Fassler et al. (1996) Methods Enzymol 273:3-29.
Ayoubi et al.
(1996), 10(4) FASEB J 10(4):453-60, Goldsteine et al. (1995) Biotechnol. Annu.
Rev.
1:105-28, Azizkhan et al. (1993) Crit. Rev. Eukaryot. Gene Expr. 3(4):229-54,
Dynan
(1989) Cell 58(1):1-4, Levine (1989) Cell 59(3):405-8, and Berk et al. (1986)
Annu. Rev.
Genet. 20:45-79, as well as U.S. Patent No. 6,194,191. Other suitable
promoters can be
identified by use of the Eukaryotic Promoter Database (release 68) (available
at the
worldwide website address epd.isb-sib.ch/) and other similar databases, such
as the
Transcription Regulatory Regions Database (TRRD) (version 4.1) (available at
the
worldwide website address bionet.nsc.ru/tiTd/) and the transcription factor
database
(TRANSFAC) (available at the worldwide website address
transfac.gbf.de/TRANSFAC/index.html).
As an alternative to a promoter, particularly in RNA vectors and constructs, a
vector or nucleic acid of the invention can comprise one or more internal
ribosome entry
sites (IRESs), IRES-encoding sequences, or RNA sequence enhancers (Kozak
consensus
sequence analogs), such as the tobacco mosaic virus omega prime sequence.
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A vector or polynucleotide of the invention can include an upstream activator
sequence (UAS), such as a Ga14 activator sequence (see, e.g., U.S. Patent No.
6,133.028)
or other suitable upstream regulatory sequence (see, e.g., U.S. No.
6,204,060).
A vector or polynucleotide of the invention can include a Kozak consensus
sequence that is functional in a mammalian cell. The Kozak sequence can be a
naturally
occurring or modified sequence, such as the modified Kozak consensus sequences
described in U.S. Patent No. 6,107,477.
Specific initiation signals can aid in efficient translation of a coding
sequence of
the invention, such as a mutant CTLA-4 ECD polypeptide-encoding nucleotide
sequence.
Such signals can be included in a vector of the invention. These signals can
include, e.g.,
the ATG initiation codon and adjacent sequences. In cases where a coding
sequence, its
initiation codon. and upstream sequences are inserted into an appropriate
expression
vector, no additional translational control signals may be needed. However, in
cases
where only a coding sequence (e.g., a mature protein coding sequence), or a
portion
thereof is inserted, exogenous nucleic acid transcriptional control signals
including the
ATG initiation codon must be provided. Furthermore, the initiation codon must
be in the
correct reading frame to ensure transcription of the entire insert. Exogenous
transcriptional elements and initiation codons can be of various origins ¨
both natural and
synthetic. The efficiency of expression can be enhanced by the inclusion of
enhancers
appropriate to the cell system in use (see, e.g., Scharf et al., Results
Probl. Cell. Differ.
20:125-62 (1994); and Bittner et al., Meth. Enzymol. 153:516-544 (1987)).
Suitable
enhancers include the Rous sarcoma virus (RSV) enhancer and the RTE enhancers
described in U.S. Patent No. 6,225,082.
The skilled artisan will recognize that the introduction of a start codon
(ATG) to
the 5' end of a particular nucleotide sequence of interest usually results in
the addition of
an N-terminal methionine to the encoded amino acid sequence when the sequence
is
expressed in a mammalian cell (other modifications may occur in bacterial
and/or other
eukaryotic cells, such as introduction of an formyl-methionine residue at a
start codon).
For expression of a nucleic acid of the invention in eukaryotic cells, a start
codon and a
nucleotide sequence encoding a signal peptide are typically be included at the
5' end of a
nucleic acid sequence of the invention (e.g., SEQ ID NO:80), and a termination
codon is
typically included at the C terminus of the nucleic acid (e.g., SEQ ID NO:80).
An
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exemplary signal peptide sequence is the hCTLA-4 signal peptide sequence (SEQ
ID
NO:182); the nucleic acid sequence encoding the tissue plasminogen activator
signal
peptide is shown in SEQ ID NO:181. Another exemplary signal peptide sequence
is the
hCTLA-4 signal peptide sequence (SEQ ID NO:216), which is encoded by the
nucleic
acid sequence shown in SEQ ID NO:215.
Termination sequences are discussed in detail below.
Such elements can be included in the vector construct of choice. Upon
expression, the polypeptide variant encoded by the nucleic acid (e.g., SEQ ID
NO:80) will
initially include an N-terminal methionine residue and the signal peptide
sequence.
However, the N-terminal methionine and signal peptide sequence will be cleaved
upon
secretion, thereby generating the encoded polypeptide (e.g., SEQ ID NO:1).
The expression level of a nucleic acid of the invention (or a corresponding
polypeptide of the invention can be assessed by any suitable technique.
Examples include
Northern Blot analysis (discussed in, e.g., McMaster et al., Proc. Natl. Acad.
Sci. USA
74(11):4835-38 (1977) and Sambrook, WI-a), reverse transcriptase-polymerase
chain
reaction (RT-PCR) (as described in, e.g., U.S. 5,601,820 and Zaheer et al.,
Neurochem.
Res. 20:1457-63 (1995)), and in situ hybridization techniques (as described
in, e.g., U.S.
Patent Nos. 5,750,340 and 5,506,098). Quantification of proteins also can be
accomplished by the Lowry assay and other protein quantification assays (see,
e.g.,
Bradford, Anal. Biochem. 72:248-254 (1976); Lowry et al., J. Biol. Chem.
193:265
(1951)). Western blot analysis of recombinant polypeptides of the invention
obtained
from the lysate of cells transfected with polynucleotides encoding such
recombinant
polypeptides is another suitable technique for assessing levels of recombinant
polypeptide
expression.
A vector, e.g., expression vector, or polynucleotide of the invention can
comprise a
ribosome-binding site for translation initiation and a transcription-
terminating region. A
suitable transcription-terminating region is, for example, a polyadenylation
sequence that
facilitates cleavage and polyadenylation of an RNA transcript produced from a
DNA
sequence. Any suitable polyadenylation sequence can be used, including a
synthetic
optimized sequence, as well as the polyadenylation sequence of BGH (Bovine
Growth
Hormone), human growth hormone gene, polyoma virus, TK (Thymidine Kinase), EBV
(Epstein Barr Virus), rabbit beta globin, and the papillomaviruses, including
human
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papillomaviruses and BPV (Bovine Papilloma Virus). Suitable polyadenylation
(polyA)
sequences also include the SV40 (human Sarcoma Virus-40) polyadenylation
sequence
and the BGH polyA sequence. Such polyA sequences are described in. e.g.,
Goodwin et
al. (1998) Nucleic Acids Res. 26(12):2891-8, Schek et al. (1992) Mol. Cell.
Biol.
12(12):5386-93, and van den Hoff et al. (1993) Nucleic Acids Res. 21(20:4987-
8.
Additional principles related to selection of appropriate polyadenylation
sequences are
described in, e.g., Levitt et al. (1989) Genes Dev. 1989 3(7):1019-1025, Jacob
et al. (1990)
Crit. Rev. Eukaryot. Gene Expr. 1(1):49-59, Chen et al. (1995) Nucleic Acids
Res.
23(14):2614-2620, Moreira et al. (1995) EMBO J. 14(15):3809-3819, Carswell et
al.
(1989) Mol. Cell. Biol. 9(10):4248-4258.
A vector or polynucleotide of the invention can further comprise site-specific
recombination sites, which can be used to modulate transcription of a
nucleotide sequence
of interest, as described in, e.g., U.S. Patent Nos. 4,959,317, 5,801,030 and
6,063,627,
European Patent Application No. 0 987 326 and Int'l Patent App. Publ. No. WO
97/09439.
A vector or polynucleotide of the invention can also comprise a nucleic acid
encoding a secretion/localization sequence, to target polypeptide expression
to a desired
cellular compartment, membrane, or organelle, or to direct polypeptide
secretion to the
periplasmic space or into the cell culture media. Such sequences are known in
the art, and
include secretion leader peptides or signal peptides, organelle targeting
sequences (e.g.,
nuclear localization sequences, ER retention signals, tnitochondrial transit
sequences,
chloroplast transit sequences), membrane localization/anchor sequences (e.g.,
stop transfer
sequences, GPI anchor sequences), and the like. Polynucleotides of the
invention can be
fused, for example, in-frame to such a nucleic acid encoding a secretion
and/or
localization sequence. Polypeptides expressed by such polynucleotides of the
invention
may include the amino acid sequence corresponding to the secretion and/or
localization
sequence(s).
In addition, a vector or polynucleotide of the invention can comprise one or
more
selectable marker nucleotide sequences or genes to provide a phenotypic trait
for selection
of transformed host cells, such as dihydrofolate reductase resistance,
neomycin resistance,
G418 resistance, puromycin resistance, and/or blasticidin resistance for
eukaryotic cell
culture, or such as tetracycline or ampicillin resistance in E. coli.
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A vector or polynucleotide of the invention can also comprise an origin of
replication useful for propagation in a microorganism. The bacterial origin of
replication
(On) utilized is preferably one that does not adversely affect gene expression
in
mammalian cells. Examples of useful origin of replication sequences include
the fl phage
on, RK2 oriV, pUC on, and the pSC101 on. Origin of replication sequences
include the
ColEI on and the p15 (available from plasmid pACYC177, New England Biolab,
Inc.),
alternatively another low copy on sequence (similar to p15) can be desirable
in some
contexts. The nucleic acid in this respect desirably acts as a shuttle vector,
able to
replicate and/or be expressed in both eukaryotic and prokaryotic hosts (e.g.,
a vector
comprising an origin of replication sequences recognized in both eukaryotes
and
prokaryotes).
The invention includes a naked DNA or RNA vector, including, for example, a
linear expression element (as described in, e.g., Sykes and Johnston (1997)
Nat Biotech
17:355-59), a compacted nucleic acid vector (as described in, e.g., U.S.
Patent No.
6,077,835 and/or Int'l Pat. App. Pub!. No. WO 00/70087), a plasmid vector such
as
pCDNA3.1, pBR322, pUC 19/18, or pUC 118/119, a "midge" minimal-sized nucleic
acid
vector (as described in, e.g., Schakowski et al. (2001) Mol. Ther. 3:793-800)
or as a
precipitated nucleic acid vector construct, such as a CaPO4 precipitated
construct (as
described in, e.g., Int'l Patent Appn WO 00/46147, Benvenisty and Reshef
(1986) Proc.
Natl. Acad. Sci. USA 83:9551-55, Wigler et al. (1978), Cell 14:725, and Coraro
and
Pearson (1981) Somatic Cell Genetics 7:603), comprising a nucleic acid of the
invention.
For example, the invention provides a naked DNA plasmid comprising SEQ ID
NO:80
operably linked to a CMV promoter or CMV promoter variant and a suitable
polyadenylation sequence. Naked nucleotide vectors and the usage thereof are
known in
the art (see, e.g., U.S. Pat. Nos. 5,589,466 and 5,973,972).
A vector of the invention typically is an expression vector that is suitable
for
expression in a bacterial system, eukaryotic system, mammalian system, or
other system
(as opposed to a vector designed for replicating the nucleic acid sequence
without
expression, which can be referred to as a cloning vector). For example, in one
aspect, the
invention provides a bacterial expression vector comprising a nucleic acid
sequence of the
invention (e.g., nucleic acid sequence encoding a recombinant mutant CTLA-4-
Ig).
Suitable vectors include, for example, vectors which direct high level
expression of fusion
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proteins that are readily purified (e.g., multifunctional E. coli cloning and
expression
vectors such as BLUESCR1PT (Stratagene), pIN vectors (Van Heeke & Schuster, J.
Biol.
Chem. 264:5503-5509 (1989); pET vectors (Novagen, Madison WI); and the like).
While
such bacterial expression vectors can be useful in expressing particular
polypeptides of the
invention, glycoproteins of the invention are preferably expressed in
eukaryotic cells and
as such the invention also provides eukaryotic expression vectors.
The expression vector can be a vector suitable for expression of the nucleic
acid of
the invention in a yeast cell. Any vector suitable for expression in a yeast
system can be
employed. Suitable vectors for use in, e.g., Saccharomyces cerevisiae include,
e.g.,
vectors comprising constitutive or inducible promoters such as alpha factor,
alcohol
oxidase and PGH (reviewed in Ausubel, supra, Berger, supra, and Grant et al.,
Meth.
Enzymol. 153:516-544 (1987)). Usually, the expression vector will be a vector
suitable
for expression of a nucleic acid of the invention in an animal cell, such as
an insect cell
(e.g.. a SF-9 cell) or a mammalian cell (e.g., a CHO cell, 293 cell, HeLa
cell, human
fibroblast cell, or similar well-characterized cell). Suitable mammalian
expression vectors
are known in the art (see, e.g., Kaufman, Mol. Biotechnol. 16(2):151-160
(2000), Van
Craenenbroeck, Eur. J. Biochem. 267(18):5665-5678 (2000), Makrides, Protein
Expr.
Purif. 17(2):183-202 (1999), and Yarranton, Curr. Opin. Biotechnol. 3(5):506-
511
(1992)). Suitable insect cell plasmid expression vectors also are known
(Braun,
Biotechniques 26(6):1038-1040:1042 (1999)).
An expression vector typically can be propagated in a host cell, which may be
a
eukaryotic cell (such as a mammalian cell, yeast cell, or plant cell) or a
prokaryotic cell,
such as a bacterial cell. Introduction of a nucleic acid vector or expression
vector into the
host cell (e.g., transfection) can be effected by calcium phosphate
transfection (see, e.g.,
calcium phosphate co-precipitation method of Graham et al., Virology 52:456-
457
(1973)), DEAE-Dextran mediated transfection, electroporation, gene or vaccine
gun,
injection, lipofection and biolistics or other common techniques (see, e.g.,
Kriegler, GENE
TRANSFER AND EXPRESSION: A LABORATORY MANUAL, Stockton Press (1990); see
Davis,
L., Dibner, M., and Battey, I., BASIC METHODS IN MOLECULAR BIOLOGY (1986) for
a
description of in vivo, ex vivo, and in vitro methods). Cells comprising these
and other
vectors of the invention form an important part of the invention.
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In one aspect, the invention provides an expression vector comprising: (i) a
first
polynucleotide sequence that encodes a first polypeptide comprising a
polypeptide
sequence having at least 95%, 96% 97%, 98%, 99%, or 100% sequence identity to
at least
one polypeptide sequence selected from the group consisting of SEQ ID NOS:1-
73,
wherein said first polypeptide binds human CD86 and/or human CD80 and/or an
extracellular domain of either or both, and/or suppresses an immune response,
and (ii) a
second polynucleotide sequence that encodes a second polypeptide comprising a
hinge
region, a CH2 domain, and a CH3 domain of an immunoglobulin (Ig) polypeptide.
The Ig
polypeptide is optionally a human Ig Fc polypeptide (e.g., IgGl, IgG2, IgG4,
etc.) or a
mutant Ig Fc polypeptide. (e.g., an Ig Fc polypeptide in which one or more
cysteine
residues have been substituted with another amino acid (e.g., a serine
residue), thereby
eliminating one or more disulfide bonds formed between two Ig chains, or in
which one or
more proline residues is substituted with another amino acid (e.g., proline)
to reduce
effector function (reduced Fc receptor binding). In another aspect, the
invention provides
an expression vector comprising a nucleotide sequence encoding a fusion
protein having at
least 95%, 96%, 97%, 98%. 99%, or 100% sequence identity to at least one
polypeptide
sequence selected from the group consisting of SEQ ID NOS: 74-79, 197-200, 205-
214,
and 219-222.
Additional nucleic acids provided by the invention include cosmids. Any
suitable
cosmid vector can be used to replicate, transfer, and express the nucleic acid
sequence of
the invention. Typically, a cosmid comprises a bacterial oriV, an antibiotic
selection
marker, a cloning site, and either one or two cos sites derived from
bacteriophage lambda.
The cosmid can be a shuttle cosmid or mammalian cosmid, comprising a SV40 oriV
and,
desirably, suitable mammalian selection marker(s). Cosmid vectors are further
described
in, e.g., Hohn et al. (1988) Biotechnology 10:113-27.
Nucleic acids of the invention can be included in and/or administered to a
host or
host cell in the form of a suitable delivery vehicle (i.e., a vector). The
vector can be any
suitable vector, including chromosomal, non-chromosomal, and synthetic nucleic
acid
vectors, or other vectors described above, and may include any combination of
the above-
described expression elements and/or other transfection-facilitating and/or
expression-
promoting sequence elements. Examples of such vectors include viruses,
bacterial
plasmids, phages, cosmids, phagemids, derivatives of SV40, baculovirus, yeast
plasmids,
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vectors derived from combinations of plasmids and phage DNA, and viral nucleic
acid
(RNA or DNA) vectors, polylysine, and bacterial cells.
Delivery of a recombinant DNA sequence of the invention can be accomplished
with a naked DNA plasmid or plasmid associated with one or more transfection-
enhancing
agents, as discussed further herein. The plasmid DNA vector can have any
suitable
combination of features. Plasmid DNA vectors may comprise a strong
promoter/enhancer
region (e.g., human CMV, RSV, SV40, SL3-3, MMTV, or HIV LTR promoter), an
effective poly(A) termination sequence, an origin of replication for plasmid
product in E.
coli, an antibiotic resistance gene as selectable marker, and a convenient
cloning site (e.g.,
a polylinker). A particular plasmid vector for delivery of the nucleic acid of
the invention
in this respect is shown in Figure 1; the construction and features of this
vector are
described in the Examples below.
In another aspect, the invention provides a non-nucleic acid vector comprising
at
least one nucleic acid or polypeptide of the invention. Such a non-nucleic
acid vector
includes, e.g., but is not limited to, a recombinant virus, a viral nucleic
acid-protein
conjugate (which, with recombinant viral particles, may sometimes be referred
to as a viral
vector), or a cell, such as recombinant (and usually attenuated) Salmonella,
Shigella,
Listeria, and Bacillus Calmette-Guerin (BCG) bacterial cells. Thus, for
example, the
invention provides a viral vector, insect vector, bacterial vector, or plant
vector comprising
a nucleic acid of the sequence of the invention. Any suitable viral, insect,
plant, or
bacterial vector can be used in this respect and a number are known in the
art. A viral
vector can comprise any number of viral polynucleotides, alone (a viral
nucleic acid
vector) or more commonly in combination with one or more (typically two,
three, or
more) viral proteins, which facilitate delivery, replication, and/or
expression of the nucleic
acid of the invention in a desired host cell.
In one aspect, intracellular bacteria (e.g., Listeria monocytogenes) can be
used to
deliver a nucleic acid of the invention. An exemplary bacterial vector for
plasmid DNA
delivery of one or more nucleic acids of the invention is Listeria monocyto
genes
(Lieberman et al., Vaccine 20;2007-2010 (2002)).
The invention includes recombinant or isolated viral vectors that have been
modified to comprise one or more nucleic acids or polypeptides of the
invention. A viral
vector may include a polynucleotide comprising all or part of a viral genome,
a viral
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protein/nucleic acid conjugate, a virus-like particle (VLP), a vector similar
to those
described in U.S. Patent No. 5,849,586 and Intl Patent App. Pub!. No. WO
97/04748, or
an intact virus particle comprising one or more viral nucleic acids, and the
viral vector is
typically engineered to include at least one nucleic acid and/or polypeptide
of the
invention. A viral vector (i.e., a recombinant virus) can comprise a wild-type
viral particle
or a modified viral particle, particular examples of which are discussed
below. Numerous
viruses are typically used as vectors for the delivery of exogenous nucleic
acids, including
at least one nucleic acid of the invention, such as a nucleic acid encoding a
mutant CTLA-
4 ECD or mutant CTLA-4-Ig described herein. Such vectors include recombinantly
modified enveloped or non-enveloped DNA and RNA viruses, typically selected
from
baculoviridiae, parvoviridiae, picomoviridiae, herpesveridiae, poxviridae,
adenoviridiae,
or picornnaviridiae. Viral vectors may be wild-type or may be modified by
recombinant
nucleic acid techniques to be replication deficient, replication competent, or
conditionally
replicating.
The viral vector can be a vector that requires the presence of another vector
or
wild-type virus for replication and/or expression (i.e., a helper-dependent
virus), such as
an adenoviral vector amplicon. Typically, such viral vectors comprise a wild-
type viral
particle, or a viral particle modified in its protein and/or nucleic acid
content to increase
transgene capacity or aid in transfection and/or expression of the nucleic
acid (examples of
such vectors include the herpes virus/AAV amplicons). The viral genome may be
modified to include inducible promoters that achieve replication or expression
only under
certain conditions.
The viral vector can be derived from or comprise a virus that normally infects
animals, preferably vertebrates, such as mammals, including, e.g., humans.
Suitable viral
vector particles in this respect, include, for example, adenoviral vector
particles (including
any virus of or derived from a virus of the adenoviridae), adeno-associated
viral vector
particles (AAV vector particles) or other parvoviruses and parvoviral vector
particles,
papillomaviral vector particles, Semliki-Forest viral vector, flaviviral
vectors, picomaviral
vectors, alphaviral vectors, herpes viral vectors, pox virus vectors,
retroviral vectors,
including lentiviral vectors. Examples of such viruses and viral vectors are
provided in,
e.g., Fields Virology, supra, Fields et al., eds., VIROLOGY, Raven Press,
Ltd., New York
(3rd ed., 1996 and 4th ed., 2001), ENCYCLOPEDIA OF VIROLOGY, R.G. Webster et
al., eds.,
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Academic Press (2nd ed., 1999), FUNDAMENTAL VIROLOGY, Fields et al., eds.,
Lippincott-
Raven (3rd ed., 1995), Levine, "Viruses," Scientific American Library No. 37
(1992),
MEDICAL VIROLOGY, D.O. White et al., eds.. Academic Press (2nd ed. 1994), and
INTRODUCTION TO MODERN VIROLOGY, Dimock, NJ. et al., eds., Blackwell
Scientific
Publications, Ltd. (1994).
Viral vectors that can be employed with nucleic acids of the invention and the
methods described herein include adeno-associated virus vectors, which are
reviewed in,
e.g., Carter (1992) Curr. Opinion Biotech. 3:533-539 (1992) and Muzcyzka
(1992) Cuff.
Top. Microbiol. Immunol. 158:97-129 (1992). Additional types and aspects of
AAV
vectors are described in, e.g., Buschacher et al., Blood 5(8):2499-504,
Carter, Contrib.
Microbiol. 4:85-86 (2000), Smith-Arica. Curr. Cardiol. Rep. 3(1):41-49 (2001),
Taj, J.
Biomed. Sci. 7(4):279-91 (2000), Vigna et al., J. Gene Med. 2(5):308-16
(2000),
Klimatcheva et al., Front. Biosci. 4:D481-96 (1999), Lever et al., Biochem.
Soc. Trans.
27(6):841-47 (1999), Snyder, J. Gene Med. 1(3):166-75 (1999), Gerich et al.,
Knee Surg.
Sports Traumatol. Arthrosc. 5(2):118-23 (1998), and During, Adv. Drug Deliv.
Review
27(1):83-94 (1997), and U.S. Patent Nos. 4,797,368, 5,139,941, 5,173,414,
5,614,404,
5,658,785, 5,858,775, and 5,994,136, as well as other references discussed
elsewhere
herein). Adeno-associated viral vectors can be constructed and/or purified
using the
methods set forth, for example, in U.S. Patent No. 4,797,368 and Laughlin et
al., Gene
23:65-73 (1983).
Alphavirus vectors can be gene delivery vectors in other contexts. Alphavirus
vectors are known in the art and described in, e.g., Carter (1992) Curr
Opinion Biotech
3:533-539, Schlesinger Expert Opin. Biol. Ther. (2001) 1(2):177-91, Polo et
al., Dev. Biol.
(Basel). 2000;104:181-5, Wahlfors et al., Gene Ther. (2000) 7(6):472-80õ Intl
Pat. App.
Publ. Nos. WO 01/81609, WO 00/39318, WO 01/81553. WO 95/07994, WO 92/10578.
Another advantageous group of viral vectors are the herpes viral vectors.
Examples are described in, e.g., Lachmann et al., CUM Opin. Mol. Ther. (1999)
1(5):622-
32, Fraefel et al., Adv. Virus Res. (2000) 55:425-51, Huard et al.,
Neuromuscul. Disord.
(1997) 7(5):299-313, Frenkel et al., Gene Ther. (1994) Suppl 1:S40-6, U.S. Pat
Nos.
6,261,552 and 5,599,691.
Retroviral vectors, including lentiviral vectors, also can be advantageous
gene
delivery vehicles in particular contexts. There are numerous retroviral
vectors known in
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the art. Examples of retroviral vectors are described in. e.g., Miller, Cun-
Top Microbiol.
Immunol. (1992) 158:1-24, Weber etal., CUM Opin. Mol. Ther. (2001) 3(5):439-
53, Hu et
al., Pharmacol. Rev. (2000) 52(4):493-511, Kim et al., Adv. Virus Res. (2000)
55:545-63.
Palu et al., Rev. Med. Virol. (2000) 10(3):185-202, Takeuchi et al., Adv. Exp.
Med. Biol.
(2000) 465:23-35, U.S. Pat. Nos. 6,326,195, 5,888,502, 5,580,766, and
5,672,510.
Baculovirus vectors are another advantageous group of viral vectors,
particularly
for the production of polypeptides of the invention. The production and use of
baculovirus
vectors is known (see, e.g., Kost, Curr. Opin. Biotechnol. 10(5):428-433
(1999); Jones,
CUIT. Opin. Biotechnol. 7(5):512-516 (1996)). Where the vector is used for
therapeutic
uses, the vector will be selected such that it is able to adequately infect
(or in the case of
nucleic acid vectors transfect or transform) target cells in which the desired
therapeutic
effect is desired.
Adenoviral vectors also can be suitable viral vectors for gene transfer.
Adenoviral
vectors are well known in the art and described in, e.g., Graham et al. (1995)
Mol.
Biotechnol. 33(3):207-220, Stephenson (1998) Clin. Diagn. Virol. 10(2-3):187-
94, Jacobs
(1993) Clin Sci (Lond). 85(2):117-22, U.S. Pat Nos. 5,922,576, 5,965,358 and
6,168.941
and International Patent Applications WO 98/22588, WO 98/56937, WO 99/15686,
WO
99/54441, and WO 00/32754. Adenoviral vectors, herpes viral vectors, and
Sindbis viral
vectors, useful in the practice of the invention and suitable for organismal
in vivo
transduction and expression of nucleic acids of the invention, are generally
described in,
e.g., Jolly (1994) Cancer Gene Therapy 1:51-64. Latchman (1994) Molec.
Biotechnol.
2:179-195, and Johanning et al. (1995) Nucl. Acids Res. 23:1495-1501.
The virus vector may be replication-deficient in a host cell. Adeno-associated
virus (AAV) vectors, which are naturally replication-deficient in the absence
of
complementing adenoviruses or at least adenovirus gene products (provided by,
e.g., a
helper virus, plasmid, or complementation cell), are included. By "replication-
deficient" is
meant that the viral vector comprises a genome that lacks at least one
replication-essential
gene function. A deficiency in a gene, gene function, or gene or genomic
region, as used
herein, is defined as a deletion of sufficient genetic material of the viral
genome to impair
or obliterate the function of the gene whose nucleic acid sequence was deleted
in whole or
in part. Replication-essential gene functions are those gene functions that
are required for
replication (i.e., propagation) of a replication-deficient viral vector. The
essential gene
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functions of the viral vector particle vary with the type of viral vector
particle at issue.
Examples of replication-deficient viral vector particles are described in,
e.g., Marconi et
al., Proc. Natl. Acad. Sci. USA 93(21):11319-20 (1996), Johnson and Friedmann,
Methods
Cell Biol. 43 (pt. A):211-30 (1994), Tirniryasova et al., J. Gene Med.
3(5):468-77 (2001),
Burton et al., Stem Cells 19(5):358-77 (2001), Kim et al., Virology 282(1):154-
67 (2001),
Jones et al., Virology 278(1):137-50 (2000). Gill et al., J. Med. Virol.
62(2):127-39
(2000). Other replication-deficient vectors are based on simple MLV vectors
(Miller et al.
(1990) Mol. Cell Biol. 10:4239; Kolberg (1992) J. NIH Res. 4:43, and Cometta
et al.
(1991) Hum. Gene. Ther. 2:215). Canary pox vectors are advantageous in
infecting human
cells but being naturally incapable of replication therein (i.e., without
genetic
modification).
The basic construction of recombinant viral vectors is well understood in the
art
and involves using standard molecular biological techniques such as those
described in,
e.g., Sambrook et al., MOLECULAR CLONING: A LABORATORY MANUAL (Cold Spring
Harbor Press 1989) and the third edition thereof (2001), Ausubel et al.,
CURRENT
PROTOCOLS IN MOLECULAR BIOLOGY (Wiley Interscience Publishers 1995), and
Watson,
supra, and several of the other references mentioned herein. For example,
adenoviral
vectors can be constructed and/or purified using the methods set forth, for
example, in
Graham et al., Mol. Biotechnol. 33(3):207-220 (1995), U.S. Patent No.
5,965,358,
Donthine et al., Gene Ther. 7(20):1707-14 (2000), and other references
described herein.
Adeno-associated viral vectors can be constructed and/or purified using the
methods set
forth, for example, in U.S. Patent No. 4,797,368 and Laughlin et al., Gene
23:65-73
(1983). Similar techniques are known in the art with respect to other viral
vectors,
particularly with respect to herpes viral vectors (see e.g., Lachman et al.,
Curr. Opin. Mol.
Ther. 1(5):622-32 (1999)), lentiviral vectors, and other retroviral vectors.
In general, the
viral vector comprises an insertion of the nucleic acid (for example, a wild-
type adenoviral
vector can comprise an insertion of up to 3 KB without deletion), or, more
typically,
comprises one or more deletions of the virus genome to accommodate insertion
of the
nucleic acid and additional nucleic acids, as desired, and to prevent
replication in host
cells.
Non-viral vectors, such as, e.g., DNA plasmids, naked nucleic acids, and
nucleic
acid complexed with a delivery vehicle such as a liposome, also can be
associated with
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molecules that target the vector to a particular region in the host (e.g., a
particular organ,
tissue, and/or cell type). For example. a nucleotide can be conjugated to a
targeting
protein, such as a viral protein that binds a receptor or a protein that binds
a receptor of a
particular target (e.g., by modification of the techniques in Wu et al., J.
Biol. Chem.
263(29):14621-24 (1988)). Targeted cationic lipid compositions are known (see,
e.g.,
U.S. 6,120,799). Other techniques for targeting genetic constructs are
provided in Int'l
Pat. App. Publ. No. WO 99/41402.
Expression Hosts
The present invention also provides engineered host cells transduced,
transfected
or transformed with a vector of the invention (e.g., a cloning vector or
expression vector)
or a nucleic acid of the invention. The engineered host cells can be cultured
in
conventional nutrient media modified as appropriate for activating promoters,
selecting
transformants, or amplifying the nucleic acid of interest. The culture
conditions, such as
temperature, pH, and the like, are those previously used with the host cell
selected for
expression, and will be apparent to those skilled in the art and in the
references cited
herein, including, e.g., Freshney (1994) Culture of Animal Cells, a Manual of
Basic
Technique, 3rd ed., Wiley - Liss, New York and the references cited therein.
Polypeptides
of the invention encoded by such vectors or nucleic acids of the invention are
expressed in
such host cells and can be isolated by standard techniques. For example,
polypeptides
released into the cell culture can be isolated from the culture by
ultracentrifugation or
similar techniques.
The polypeptides of the invention can be produced in a variety of expression
hosts,
including, but not limited to, animal cells, such as mammalian cells (e.g.,
CHO cells),
including human and non-human primate cells, and in non-animal cells, such as
plants,
yeast, fungi, bacteria, and the like. Examples of suitable expression hosts
include bacterial
cells, such as E. coli, Streptomyces, and Salmonella typhimurium; fungal
cells, such as
Saccharomvces cerevisiae, Pichia pastoris, and Neurospora crassa; insect cells
such as
Drosophila and Spodoptera frugiperda; mammalian cells, such as CHO (e.g., CHO-
K1),
COS (e.g., COS-1, COS-7), BHK, and HEK (e.g., HEK 293) cells, Bowes melanoma
cells, and plant cells. As noted above, the invention is not limited by the
host cells
employed. In addition to Sambrook, Berger and Ausubel, all supra, details
regarding cell
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culture are found in, e.g., Payne et al. (1992) Plant Cell and Tissue Culture
in Liquid
Systems John Wiley & Sons, Inc. New York, NY; Gamborg and Phillips (eds.)
(1995)
Plant Cell, Tissue and Organ Culture; Fundamental Methods Springer Lab Manual,
Springer-Verlag (Berlin Heidelberg NY); Atlas & Parks (eds.) The Handbook of
Microbiological Media (1993) CRC Press, Boca Raton, FL. Such host cells can be
adapted to growth in serum-free, protein-free medium, animal component-free
medium,
such as, e.g., a chemically defined (CD) medium (such as, e.g., CD OptiCHOTm
(Invitrogen, #12681) using procedures known in the art.
The invention provides a cell(s) comprising any one or more of the nucleic
acids,
vectors, or other constructs of the invention (e.g., a construct expressing a
mutant CTLA-4
ECD or mutant CTLA-4-Ig) described herein or any combination thereof. Also
included
is a cell comprising one or more of any of the polypeptides, antibodies, or
fusion proteins,
or other constructs of the invention described herein, or any combination of
one or more of
these. A cell of the invention is typically an isolated or recombinant cell
and may
comprise a host cell. Such a cell, e.g., recombinant cell, may be modified by
transformation, transfection, and/or infection with at least one nucleic acid,
vector, or
other construct of the invention. Such a cell can be a eukaryotic cell (e.g.,
mammalian,
yeast, or plant cell) or a prokaryotic cell (e.g., bacterial cell) and can be
transformed with
any such construct of the invention using a variety of known methods,
including, e.g.,
calcium phosphate transfection (see, e.g., calcium phosphate co-precipitation
method),
DEAE-Dextran mediated transfection, electroporation (Irving et al., Cell
64;891-901
(1991)), gene or vaccine gun, injection, lipofection and biolistics or other
common
techniques as noted above. See also Inovio Biomedical Corp. electroporation
methods
and technology at the worldwide website address inovio.com.
A host cell strain is optionally chosen for its ability to modulate the
expression of
the inserted sequences or to process the expressed protein in the desired
fashion. Such
modifications of the protein include, but are not limited to, acetylation,
carboxylation,
glycosylation, phosphorylation, lipidation and acylation. Different host cells
such as E.
coli, Bacillus sp., yeast, or mammalian cells, such as CHO, HeLa, BHK, MDCK,
HEK
293, WI38, etc. have specific cellular machinery and characteristic mechanisms
for such
post-translational activities and may be chosen to ensure the correct
modification and
processing of the introduced foreign protein.
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A nucleic acid of the invention can be inserted into an appropriate host cell
(in
culture or in a host organism) to permit the host to express a protein of
interest (e.g.,
mutant CTLA-4 ECD or mutant CTLA-4-Ig). Any suitable host cell can be
transformecUtransduced by the nucleic acids of the invention. Examples of
appropriate
expression hosts include: bacterial cells, such as E. coli, Streptonivces.
Bacillus sp., and
Salmonella typlzimurium; fungal cells, such as Saccharomyces cerevisiae,
Pichia pastoris,
and Neurospora crassa; insect cells such as Drosophila and Spodoptera
frugiperda;
mammalian cells such as Vero cells, HeLa cells, CHO cells (e.g., CHO-K1), COS
cells,
WI38 cells, NIH-3T3 cells (and other fibroblast cells, such as MRC-5 cells),
MDCK cells,
KB cells, SW-13 cells, MCF7 cells, BHK cells, HEK-293 cells, Bowes melanoma
cells,
and plant cells, etc.
The present invention also provides host cells that are transduced,
transformed or
transfected with at least one nucleic acid or vector of the invention. As
discussed above, a
vector of the invention typically comprises a nucleic acid of the invention.
Host cells are
genetically engineered (e.g., transduced, transformed, infected, or
transfected) with the
vectors of the invention, which may be, e.g., a cloning vector or an
expression vector. The
vector may be in the form of a plasmic', a viral particle, a phage, attenuated
bacteria, or
any other suitable type of vector. Host cells suitable for transduction and/or
infection with
viral vectors of the invention for production of the recombinant polypeptides
of the
invention and/or for replication of the viral vector of the invention include
the above-
described cells. Examples of cells that have been demonstrated as suitable for
packaging
of viral vector particles are described in, e.g., Polo et al., Proc. Natl.
Acad. Sci.
96(8):4598-603 (1999), Farson et al., J. Gene Med. 1(3):195-209 (1999),
Sheridan et al.,
Mol. Ther. 2(3):262-75 (2000), Chen et al., Gene Ther. 8(9):697-703 (2001),
and Pizzaro
et al., Gene Ther. 8(10):737-745 (2001). For replication-deficient viral
vectors, such as
AAV vectors, complementing cell lines, cell lines transformed with helper
viruses, or cell
lines transformed with plasmids encoding essential genes, are needed for
replication of the
viral vector.
The engineered host cells can be cultured in conventional nutrient media
modified
as appropriate for activating promoters, selecting transformants, or
amplifying the gene of
interest. Host cells can be cultured in serum-containing medium or serum-free
medium.
Host cells can be cultured in a serum-free, protein-free, animal component-
free medium,
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including, e.g., a chemically defined medium (e.g., CD OptiCHOTNI (Invitrogen,
#12681)).
The cell culture medium can be supplemented, if desired, with supplements
known to
those of skill, such as, e.g., one or more amino acid(s). such L-glutamine
(e.g.. 2% v/v 200
mM L-glutamine (Invitrogen, #25031)). The culture conditions, such as
temperature, pH,
and the like, are those previously used with the host cell selected for
expression, and will
be apparent to those skilled in the art and in the references cited herein,
including, e.g.,
ANIMAL CELL TEcHNoLoGy, Rhiel et al., eds.. (Kluwer Academic Publishers 1999),
Chaubard et al., Genetic Eng. News 20(18) (2000), Hu et al., ASM News 59:65-68
(1993),
Hu et al., Biotechnol. Prog. 1:209-215 (1985), Martin et al., Biotechnol.
(1987), Freshney,
CULTURE OF ANIMAL CELLS: A MANUAL OF BASIC TECHNIQUE, 4th ed., (Wiley, 2000),
Mather, INTRODUCTION TO CELL AND TISSUE CULTURE: THEORY AND TECHNIQUE,
(Plenum Press, 1998), Freshney, CULTURE OF IMMORTALIZED CELLS, 3rd ed., (John
Wiley
& Sons, 1996), CELL CULTURE: ESSENTIAL TECHNIQUES. Doyle et al., eds. (John
Wiley &
Sons 1998), and GENERAL TECHNIQUES OF CELL CULTURE, Harrison et al., eds.,
(Cambridge Univ. Press 1997).
The nucleic acid also can be contained, replicated, and/or expressed in plant
cells.
Techniques related to the culture of plant cells are described in, e.g., Payne
et al. (1992)
PLANT CELL AND TISSUE CULTURE IN LIQUID SYSTEMS John Wiley & Sons, Inc. New
York, NY; Gamborg and Phillips (eds.) (1995) PLANT CELL, TISSUE AND ORGAN
CULTURE: FUNDAMENTAL METHODS SPRINGER LAB MANUAL, Springer-Verlag (Berlin
Heidelberg New York) and Plant Molecular Biology (1993) R.R.D. Croy (ed.) Bios
Scientific Publishers, Oxford, U.K. ISBN 0 12 198370 6. Cell culture media in
general
are set forth in Atlas and Parks (eds.) THE HANDBOOK OF MICROBIOLOGICAL MEDIA
(1993) CRC Press, Boca Raton, FL.
For lone-term, high-yield production of recombinant proteins, stable
expression
systems can be used. For example, cell lines that stably express a polypeptide
of the
invention can be transduced with expression vectors comprising viral origins
of replication
and/or endogenous expression elements and a selectable marker gene. Following
the
introduction of the vector, cells in the cell line may be allowed to grow for
1-2 days in an
enriched media before they are switched to selective media. The purpose of the
selectable
marker is to confer resistance to selection, and its presence allows growth
and recovery of
cells that successfully express the introduced sequences. For example,
resistant clumps of
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stably transformed cells can be proliferated using tissue culture techniques
appropriate to
the cell type. Serum-free media are readily available (e.g., JRH Biosciences,
SAFC
Biosciences, Sigma-Aldrich Corporation, worldwide web at sigmaaldrich.com).
Serum-
free media or conditioned medium (e.g., growth medium previously harvested
from
untransfected or naïve cell cultures) may be preferred for protein production
or cell-
banking in some instances.
The invention includes immortalized cells or cell lines comprising one or more
polypeptides (including, e.g., dimeric or monomeric fusion proteins and
multimeric
polypeptides), conjugates, nucleic acids, or vectors or the invention.
Host cells transformed with an expression vector and/or polynucleotide are
optionally cultured under conditions suitable for the expression and recovery
of the
encoded protein from cell culture. The polypeptide or fragment thereof
produced by such
a recombinant cell may be secreted, membrane-bound, or contained
intracellularly,
depending on the sequence and/or the vector used. Expression vectors
comprising
polynucleotides encoding mature polypeptides of the invention can be designed
with
signal sequences that direct secretion of the mature polypeptides through a
prokaryotic or
eukaryotic cell membrane. Such signal sequences are typically incorporated
into the
vector such that the signal sequence is expressed at the N-terminus of the
polypeptide of
the invention. Principles related to such signal sequences are discussed
elsewhere herein.
Polypeptide Production and Recovery
Following transduction of a suitable host strain and growth of the host strain
to an
appropriate cell density, the selected promoter is induced by appropriate
means (e.g.,
temperature shift or chemical induction) and cells are cultured for an
additional period.
Cells are typically harvested by centrifugation, disrupted by physical or
chemical means,
and the resulting crude extract retained for further purification. Microbial
cells employed
in expression of proteins can be disrupted by any convenient method, including
freeze-
thaw cycling, sonication, mechanical disruption, or use of cell lysing agents,
or other
methods, which are well know to those skilled in the art.
As noted, many references are available for the culture and production of many
cells, including cells of bacterial, plant, animal (especially mammalian) and
archebacterial
origin. See e.g., Sambrook, Ausubel, and Berger (all supra), as well as
Freshney (1994)
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Culture of Animal Cells, a Manual of Basic Technique, Third edition, Wiley-
Liss, New
York and the references cited therein; Doyle and Griffiths (1997) Mammalian
Cell
Culture: Essential Techniques, John Wiley and Sons, NY; Humason (1979) Animal
Tissue
Techniques, fourth edition W.H. Freeman and Company; and Ricciardelli, et al.,
(1989) In
vitro Cell Dev. Biol. 25:1016 1024. For plant cell culture and regeneration,
Payne et al.
(1992) Plant Cell and Tissue Culture in Liquid Systems, John Wiley & Sons,
Inc. New
York, N.Y.; Gamborg and Phillips (eds.) (1995) Plant Cell, Tissue and Organ
Culture;
Fundamental Methods Springer Lab Manual, Springer-Verlag (Berlin Heidelberg
New
York) and Plant Molecular Biology (1993) R. R. D. Croy, Ed. Bios Scientific
Publishers,
Oxford, U.K. ISBN 0 12 198370 6. Cell culture media in general are set forth
in Atlas and
Parks (eds.) The Handbook of Microbiological Media (1993) CRC Press, Boca
Raton, Fla.
Additional information for cell culture is found in available commercial
literature such as
the Life Science Research Cell Culture Catalogue (1998) from Sigma-Aldrich,
Inc. (St.
Louis, Mo.) ("Sigma-LSRCCC") and, e.g., the Plant Culture Catalogue and
supplement
(1997) also from Sigma-Aldrich, Inc (St. Louis, Mo.) ("Sigma-PCCS").
Polypeptides of the invention can be recovered and purified from recombinant
cell
cultures by any of a number of methods well known in the art, including
ammonium
sulfate or ethanol precipitation, acid extraction, anion or cation exchange
chromatography,
phosphocellulose chromatography, hydrophobic interaction chromatography,
affinity
chromatography (e.g., using any of the tagging systems noted herein),
hydroxylapatite
chromatography, and lectin chromatography. Protein refolding steps can be
used, as
desired, in completing configuration of the mature protein. Finally, high
performance
liquid chromatography (HPLC) can be employed in the final purification steps.
In
addition to the references noted supra, a variety of purification methods are
well known in
the art, including, e.g., those set forth in Sandana (1997) Bioseparation of
Proteins,
Academic Press. Inc.; and Bollag et al. (1996) Protein Methods, 2<sup>nd</sup>
Edition Wiley-
Liss, NY; Walker (1996) The Protein Protocols Handbook Humana Press, NJ,
Harris and
Angal (1990) Protein Purification Applications: A Practical Approach IRL Press
at
Oxford, Oxford, England; Harris and Angal Protein Purification Methods: A
Practical
Approach 1RL Press at Oxford, Oxford, England; Scopes (1993) Protein
Purification:
Principles and Practice 3<sup>rd</sup> Edition Springer Verlag, NY; Janson and Ryden
(1998)
Protein Purification: Principles, High Resolution Methods and Applications,
Second
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Edition Wiley-VCH, NY; and Walker (1998) Protein Protocols on CD-ROM Humana
Press, NJ.
One of skill would understand that fusion proteins of the invention (e.g.,
mutant
CTLA-4-Ig fusion protein) can be made by a variety of methods described
herein,
including , e.g., those set forth in Example 1 for making LEA29Y-Ig. For
example, in
place of the LEA29Y-encoding nucleic acid, a nucleic acid sequence encoding a
mutant
CTLA-4 ECD polypeptide of the invention (e.g., D3-54 polypeptide) can be
cloned into
the IgG2 Fc fusion vector to produce a vector encoding the mutant CTLA-4-Ig
fusion
protein (e.g., D3-54-IgG2), stable CHO-Kl cells expressing such mutant CTLA-4-
Ig
fusion protein can be made by transfecting such cells with the mutant CTLA-4-
Ig fusion
protein-encoding vector, and the resultant mutant CTLA-4-Ig fusion protein
(e.g.. D3-54-
IgG2) can be expressed (typically in dimeric form) and purified as described
in Example
1.
In vitro Expression Systems
Cell-free transcription/translation systems can also be employed to produce
recombinant polypeptides of the invention or fragments thereof using DNAs
and/or RNAs
of the present invention or fragments thereof. Several such systems are
commercially
available. A general guide to in vitro transcription and translation protocols
is found in
Tymms (1995) IN VITRO TRANSCRIPTION AND TRANSLATION PROTOCOLS: METHODS IN
MOLECULAR BIOLOGY, Volume 37, Garland Publishing, New York.
METHODS OF THE INVENTION
Polypeptides (includin2, e.g., dimeric and monomeric fusion proteins and
multimeric polypeptides), conjugates, compositions, nucleic acids, vectors,
and cells of the
invention exhibit a variety of properties and characteristics and are believed
useful in a
variety of applications, including, but not limited to, e.2., in prophylactic
or therapeutic
methods for treating a variety of immune system diseases, disorders and
conditions in
which modulation or regulation of the immune system and immune system
responses may
be of benefit. For example, polypeptides, conjugates, compositions, nucleic
acids, vectors,
and cells of the invention that have an ability to bind CD80 and/or CD86 or an
ECD of
either or both and/or an ability to inhibit an immune response are believed to
be useful in
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prophylactic and/or therapeutic methods for inhibiting or suppressing an
immune response
in a subject, methods for inhibiting rejection of a tissue, cell, or organ
transplant from a
donor by a recipient, and other methods described elsewhere herein. Some such
polypeptides, conjugates, compositions, nucleic acids, vectors, and cells of
the invention
are expected to be useful in methods for method of modulating or inhibiting
the interaction
of T cells expressing CD28 and/or CTLA-4 with B7-positive cells.
In one aspect, therapeutic or prophylactic methods of the invention involve
administering to a subject an effective amount of at least one such
polypeptide (including,
e.g., fusion protein, multimer, etc.), conjugate, composition, nucleic acid,
vector, and/or
cell to suppress or inhibit an immune response. In a therapeutic context, the
subject is
typically one inflicted with an immune system disease, disorder, or condition,
and
administration is conducted to prevent further progression of the disease,
disorder or
condition. For example, administration of a molecule of the invention to a
subject
suffering from an immune system disease (e.g., autoimmune disease) can result
in
suppression or inhibition of such immune system attack or biological responses
associated
therewith. By suppressing this immune system attack on healthy body tissues,
the
resulting physical symptoms (e.g., pain, joint inflammation, joint swelling or
tenderness)
resulting from or associated with such attack on healthy tissues can be
decreased or
alleviated, and the biological and physical damage resulting from or
associated with the
immune system attack can be decreased, retarded, or stopped.
In a prophylactic context, the subject may be one inflicted with, susceptible
to, or
believed to present an immune system disease, disorder or condition, and
administration is
typically conducted to prevent progression of the disease, disorder or
condition, inhibit or
alleviate symptoms, signs, or biological responses associated therewith,
prevent bodily
damage potentially resulting therefrom, and/or maintain or improve the
subject's physical
functioning.
In one aspect, the invention provides a method of modulating the interaction
of T
cells expressing CD28 and/or CTLA-4 with B7-positive cells, the method
comprising
contacting B7-positive cells with at least one of the following in an
effective amount to
modulate the interaction of B7-positive cells with CD28-positive T cells
and/or CTLA-4-
positive T cells: (1) a polypeptide of the invention (e.g., mutant CTLA-4-ECD
polypeptide or dimeric or monomeric mutant CTLA-4-Ig fusion protein); (2) a
multimer
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comprising one of more polypeptides of the invention (e.g., a dimer comprising
any two
such polypeptides or a tetramer comprising any four such polypeptides); (3) a
conjugate
comprising at least one polypeptide of the invention; (4) a nucleic acid of
the invention
(e.g., a nucleic acid encoding a polypeptide of the invention); (5) a vector
comprising a
nucleic acid of the invention or encoding a polypeptide of the invention; (6)
a cell or
population of cells comprising a polypeptide, nucleic acid, conjugate, and/or
vector of the
invention; and/or (7) composition of the invention, wherein the interaction of
B7-positive
cells with CD28-positive T cells and/or CTLA-4-positive T cells is modulated.
Typically,
the modulatory effect is an inhibitory effect such that the interaction of B7-
positive cells
with CD28-positive T cells and/or CTLA-4-positive T cells is inhibited. In
some instances,
the B7-positive cells are antigen-presenting cells (APCs). In some such
methods, the
interaction of B7-2-positive cells (e.g., APCs expressing B7-2 (CD86)) with
CD28-
positive T cells is inhibited. In some such methods, the interaction of B7-1-
positive cells
(e.g., APCs expressing B7-1 (CD80)) with CD28-positive T cells is inhibited.
In another aspect, the invention provides a method of inhibiting the
interaction of
CD28-positive T cells and/or CTLA-4-positive T cells with B7-positive cells,
the method
comprising contacting B7-positive cells (e.g., B7-1- positive cells and/or B7-
2-positive
cells) with at least one of the following molecules or components of the
invention in an
effective amount to inhibit the interaction of CD28-positive T cells and/or
CTLA-4-
positive T cells with B7-positive cells: (1) a polypeptide of the invention
(e.g., mutant
CTLA-4-ECD polypeptide or dimeric or monomeric mutant CTLA-4-Ig fusion
protein);
(2) a multimer comprising one of more polypeptides of the invention (e.g., a
dimer
comprising any two such polypeptides or a tetramer comprising any four such
polypeptides); (3) a conjugate comprising at least one polypeptide of the
invention; (4) a
nucleic acid of the invention (e.g., a nucleic acid encoding a polypeptide of
the invention);
(5) a vector comprising a nucleic acid of the invention or encoding a
polypeptide of the
invention; (6) a cell or population of cells comprising a polypeptide, nucleic
acid,
conjugate, and/or vector of the invention; and/or (7) composition of the
invention, wherein
the interaction of CD28-positive T cells and/or CTLA-4-positive T cells with
B7-positive
cells is inhibited. In some instances, the B7-positive cells are APCs. In some
instances,
the interaction of CD28-positive T cells with hB7-1-positive cells and/or hB7-
2-positive
cells is inhibited. In some such methods, inhibition of the interaction of
CD28-positive T
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cells with hB7-1-positive cells and/or hB7-2-positive cells results in
suppression or
inhibition of one or more of the following: T cell activation or
proliferation, cytokine
synthesis or production (e.g., production of TNF-a, IFN-7, IL-2), induction of
various
activation markers (e.g., CD25, IL-2 receptor), inflammation, joint swelling
or tenderness,
serum level of C-reactive protein, anti-collagen antibody production, and/or T
cell-
dependent antibody response(s).
In some such methods, at least one such molecule or component of the invention
is
administered to a subject in an effective amount to inhibit the interaction of
endogenous
CD28-positive T cells with endogenous B7-1-positive cells and/or B7-2-positive
cells in
the subject. In some such methods, the interaction of endogenous CD28-positive
T cells
with endogenous B7-positive cells expressing B7-2 (CD86) or B7-1 (CD80) is
inhibited.
In some instances, the B7-positive cells are APCs which express B7-2 or B7-1,
and the
interaction of B7-2 or B7-1 with CD28-positive T cells is inhibited. In some
instances, the
interaction of both B7-2 and B7-1 expressed on APCs with CD28-positive T cells
is
inhibited.
In another aspect, the invention provides a method of suppressing an immune
response in vitro or in vivo. The method comprises contacting a B7-positive
cells with at
least one of the following molecules or components of the invention in
effective amount to
suppress an immune response: (1) a polypeptide of the invention (e.g., mutant
CTLA-4-
ECD polypeptide or dimeric or monomeric mutant CTLA-4-Ig fusion protein); (2)
a
multimer comprising one of more polypeptides of the invention (e.g., a dimer
comprising
any two such polypeptides or a tetramer comprising any four such
polypeptides); (3) a
conjugate comprising at least one polypeptide of the invention; (4) a nucleic
acid of the
invention (e.2., a nucleic acid encoding a polypeptide of the invention); (5)
a vector
comprising a nucleic acid of the invention or encoding a polypeptide of the
invention; (6)
a cell or population of cells comprising a polypeptide, nucleic acid,
conjugate, and/or
vector of the invention; and/or (7) composition of the invention, wherein an
immune
response is thereby suppressed. One or more immune responses may be
suppressed,
including, e.g., T cell response, T cell proliferation or activation, cytokine
synthesis or
production, inflammation, joint swelling or tenderness, serum level of C-
reactive protein,
anti-collagen antibody production, and/or T cell-dependent antibody
response(s). In such
methods comprising contacting a B7-positive cell with a polypeptide of the
invention, the
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polypeptide binds B7- l (e.g., human B7-1) expressed on B7-positive cells,
and/or binds
B7-2 (e.g., human B7-2) expressed on B7-positive cells. In some instances, the
B7-
positive cells are APCs. In some instances, an immune response is suppressed
in vitro,
such as in, e.g., an in vitro assay, including those described in detail
elsewhere herein (see,
e.g., the Examples below). In some instances, an immune response is suppressed
in vivo
in a subject to whom an effective amount to suppress an immune response is
administered,
such as, e.g., in the therapeutic or prophylactic treatment methods (e.g.,
method of treating
rheumatic disease, such as rheumatoid arthritis, or other autoimmune disease)
discussed in
detail elsewhere herein.
In another aspect, the invention provides a method of suppressing an immune
response in a subject (e.g., mammal, such as a human). The method comprises
administering to a subject in need thereof with at least one of the following
molecules or
components of the invention in a therapeutically or prophylactically effective
amount
(e.g., therapeutically or prophylactically effective dose) which suppresses an
immune
response in the subject: (1) a polypeptide of the invention (e.g., mutant CTLA-
4-ECD
polypeptide or dimeric or monomeric mutant CTLA-4-1g fusion protein); (2) a
multimer
comprising one of more polypeptides of the invention (e.g., a dimer comprising
any two
such polypeptides or a tetramer comprising any four such polypeptides); (3) a
conjugate
comprising at least one polypeptide of the invention; (4) a nucleic acid of
the invention
(e.g., a nucleic acid encoding a polypeptide of the invention); (5) a vector
comprising a
nucleic acid of the invention or encoding a polypeptide of the invention; (6)
a cell or
population of cells comprising a polypeptide, nucleic acid, conjugate, and/or
vector of the
invention; and/or (7) composition of the invention, wherein an immune response
is thereby
suppressed in the subject.
In another aspect, the invention provides a method of treating a subject
having an
immune system disease or disorder modulated by interaction of endogenous T
cells with
endogenous cells expressing CD80 and/or CD86. The method comprises
administering to
a subject in need of such treatment a therapeutically effective amount of: (1)
a polypeptide
of the invention (e.g., mutant CTLA-4-ECD polypeptide or dimeric or monomeric
mutant
CTLA-4-Ig fusion protein); (2) a multimer comprising one of more polypeptides
of the
invention (e.g., a dimer comprising any two such polypeptides or a tetramer
comprising
any four such polypeptides); (3) a conjugate comprising at least one
polypeptide of the
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invention; (4) a nucleic acid of the invention (e.g., a nucleic acid encoding
a polypeptide
of the invention); (5) a vector comprising a nucleic acid of the invention or
encoding a
polypeptide of the invention; (6) a cell or population of cells comprising a
polypeptide,
nucleic acid, conjugate, and/or vector of the invention; and/or (7)
composition of the
invention, thereby treating the immune system disease or disorder in the
subject. If the
subject is a human, CD80 is human CD80, CD86 is human CD86, and CD28 is human
CD28. In some such methods, interaction between endogenous T cells expressing
CD28
and endogenous cells expressing CD86 and/or endogenous cells expressing CD80
is
inhibited.
It is believed that a variety of immune system diseases or disorders,
including
rheumatic or autoimmune system disease or disorder, may be effectively treated
using one
or more of the molecules of the invention disclosed herein, such as, e.g., a
mutant CTLA-4
ECD polypeptide (e.g., any of SEQ ID NOS:1-73, such as, e.g., D3-54 (SEQ ID
NO:36),
D3-69 (SEQ ID NO:50), or D3-27 (SEQ ID NO:24) mutant CTLA-4 ECD), or a fusion
protein thereof (e.g., D3-54-1g02 (SEQ ID NO:197 or 211), D3-69-12G2 (SEQ ID
NO:199 or 213), D3-29-IeG2 (SEQ ID NO:79 or 210)). The immune system disease
or
disorder may be or involve, e.g., but is not limited to, Addison's Disease,
Allergy,
Alopecia Areata, Alzheimer's, Antineutrophil cytoplasmic antibodies (ANCA)-
associated
vasculitis, Ankylosing Spondylitis, Antiphospholipid Syndrome (Hughes
Syndrome),
arthritis, Asthma, Atherosclerosis, Atherosclerotic plaque, autoimmune disease
(e.g.,
lupus, RA, MS, Graves' disease, etc.), Autoimmune Hemolytic Anemia, Autoimmune
Hepatitis, Autoimmune inner ear disease, Autoimmune Lymphoproliferative
syndrome,
Autoimmune Myocarditis, Autoimmune Oophoritis, Autoimmune Orchitis,
Azoospermia,
Behcet's Disease, Berger's Disease, Bullous Pemphigoid, Cardiomyopathy,
Cardiovascular disease, Celiac Sprue/Coeliac disease, Chronic Fatigue Immune
Dysfunction Syndrome (CFIDS), Chronic idiopathic polynetnitis, Chronic
Inflammatory
Demyelinating, Polyradicalneuropathy (CIPD), Chronic relapsing polyneuropathy
(Guillain-Barre syndrome), Churg-Strauss Syndrome (CSS), Cicatricial
Pemphigoid, Cold
Agglutinin Disease (CAD), COPD, CREST syndrome, Crohn's disease, Dermatitis,
Herpetiformus, Dennatomyositis, diabetes, Discoid Lupus, Eczema, Epidermolysis
bullosa acquisita, Essential Mixed Cryoglobulinemia, Evan's Syndrome,
Exophthalmos,
Fibromyalgia, Goodpasture's Syndrome, graft-related disease or disorder,
Graves'
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Disease, GVHD, Hashimoto's Thyroiditis, Idiopathic Pulmonary Fibrosis,
Idiopathic
Thrombocytopenia Purpura (ITP), IgA Nephropathy, immunoproliferative disease
or
disorder (e.g., psoriasis), Inflammatory bowel disease (MD), Insulin Dependent
Diabetes
Mellitus (IDDM), Interstitial lung disease, juvenile diabetes, Juvenile
Arthritis, juvenile
idiopathic arthritis (JIA), Kawasaki's Disease, Lambert-Eaton Myasthenic
Syndrome,
Lichen Planus, lupus, Lupus Nephritis, Lymphoscytic Lypophisitis, Meniere's
Disease,
Miller Fish Syndrome/acute disseminated encephalomyeloradiculopathy, Mixed
Connective Tissue Disease, Multiple Sclerosis (MS), muscular rheumatism,
Myalgic
encephalomyelitis (ME), Myasthenia Gravis, Ocular Inflammation, Pemphigus
Foliaceus,
Pemphigus Vulgaris, Pernicious Anaemia, Polyarteritis Nodosa, Polychondritis,
Polyglandular Syndromes (Whitaker's syndrome), Polymyalgia Rheumatica,
Polymyositis, Primary Againmaglobulinemia, Primary Biliary
Cirrhosis/Autoimmune
cholangiopathy, Psoriasis, Psoriatic arthritis, Raynaud's Phenomenon, Reiter's
Syndrome/Reactive arthritis, Restenosis, Rheumatic Fever, rheumatic disease,
Rheumatoid
Arthritis, Sarcoidosis, Schinides syndrome, Scleroderma, Sjorgen's Syndrome,
Solid-
organ transplant rejection (kidney, heart, liver, lung, etc.), Stiff-Man
Syndrome, Systemic
Lupus Erythematosus (SLE), systemic scleroderma, Takayasu Arteritis, Temporal
Arteritis/Giant Cell Arteritis, Thyroiditis, Type 1 diabetes, Type 2 diabetes,
Ulcerative
colitis, Uveitis, Vasculitis, Vitiligo, Wegener's Granulomatosis, and
preventing or
suppressing an immune response associated with rejection of a donor tissue,
cell, graft, or
organ transplant by a recipient subject. Graft-related diseases or disorders
include graft
versus host disease (GVDH), such as associated with bone marrow
transplantation, and
immune disorders resulting from or associated with rejection of organ, tissue,
or cell graft
transplantation (e.g., tissue or cell allografts or xenografts), including,
e.g., grafts of skin,
muscle, neurons, islets, organs, parenchymal cells of the liver, etc. With
regard to a donor
tissue, cell, graft or solid organ transplant in a recipient subject, it is
believed such
molecules of the invention disclosed herein (e.g., mutant CTLA-4 ECD
polypeptide or
mutant CTLA-4-Ig fusion protein) may be effective in preventing acute
rejection of such
transplant in the recipient and/or for long-term maintenance therapy to
prevent rejection of
such transplant in the recipient (e.g., inhibiting rejection of insulin-
producing islet cell
transplant from a donor in the subject recipient suffering from diabetes).
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The invention include,' any such mutant CTLA-4 ECD polypeptide or mutant
CTLA-4-1g fusion protein of the invention for use in suppressing an immune
response
associated with at least one of the above immune system diseases or disorders.
Also
provided is the use of any such mutant CTLA-4 ECD polypeptide or mutant CTLA-4-
Ig
fusion protein of the invention in the manufacture of a medicament for
suppressing an
immune response with at least one of the above immune system diseases or
disorders.
An effective amount of a molecule of the invention, such as, e.g., a mutant
CTLA-
4 ECD polypeptide (e.g., D3-54, D3-69, D3-29, D3-56. D3-75) or an Ig fusion
protein
comprising a mutant CTLA-4 ECD polypeptide of the invention (e.2., D3-54-IgG2,
D3-
69-IgG2, D3-29-IgG2, D3-56-IgG2, D3-75-IgG2, respectively), for suppressing an
immune response in a subject or treating an immune system disease or disorder
modulated
by interaction of endogenous T cells with endogenous cells expressing CD80
and/or CD86
in a subject in the methods described herein may comprise from about 0.0001
milligrams
per kilogram (mg/kg) weight of the subject to about 200 milligrams per
kilogram (mg/kg)
body weight of the subject, such as, e.g., from about 0.001 milligrams per
kilogram
(mg/kg) body weight of the subject to about 100 milligrams per kilogram
(mg/kg) weight
of the subject, or, e.g., from about 0.001 mg/k2 weight of the subject to at
least about
0.005, 0.01, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2,
3, 4, 5, 6, 7, 8, 9, 10,
25, 50, or 75 mg/kg body weight of the subject. One or more immune responses
may be
suppressed in the subject, including, e.g., T cell response. T cell activation
or proliferation,
cytokine synthesis or production (e.g., production of TNF-a, IFN-y, IL-2,
etc.), induction
of various activation markers (e.g.. CD25, IL-2 receptor, etc.), synthesis or
production of
inflammatory molecules, inflammation, joint swelling, joint tenderness, pain,
stiffness,
serum levels of C-reactive protein, anti-collagen antibody production, and/or
T cell-
dependent antibody response(s)). An effective amount of a molecule or
component of the
invention for suppressing an immune response may be an amount that suppresses
an
immune response or a symptom or sign thereof by a detectable or measurable
amount.
The immune response may be partially or completely suppressed. An effective
amount for
treating an immune system disease or disorder may be an amount that relieves,
lessens, or
alleviates at least one symptom or biological response or effect associated
with the disease
or disorder, prevents progression of the disease or disorder, or improves
physical
functioning of the subject.
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An effective amount of a molecule or component of the invention for modulating
or inhibiting the interaction of T cells expressing CD28 and/or CTLA-4 with B7-
positive
cells may be an amount that modulates or inhibits the binding between B7-
positive cells
and CD28-positive and/or CTLA-4-positive T cells, respectively. Such binding
interaction(s) may be may be partially or completely modulated or inhibited.
In some such methods, a mutant CTLA-4-Ig fusion protein dimer of the invention
is administered to the subject in a therapeutically or prophylactically
effective amount (or
dose) sufficient to suppress an immune response, treat an immune system
disease or
disorder modulated by interaction of T cells with B7-expressing cells, or
modulate or
inhibit the interaction of T cells expressing CD28 and/or CTLA-4 with B7-
positive cells.
The fusion protein dimer administered is typically a soluble Ig fusion protein
dimer. In
some such methods, the effective amount or dose of the fusion protein dimer of
the
invention comprises from about 0.001 milligrams per kilogram (mg/kg) body
weight of
the subject to about 200 milligrams per kilogram (mg/kg) body weight of the
subject (such
as, e.g., a human) or from about 0.001 mg/kg to about 300 mg/kg body weight of
the
subject. For example, the effective amount or dose of the fusion protein dimer
may
comprise from about 0.001 mg/kg body weight of the subject to at least about
0.005, 0.01,
0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3,4, 5, 10, 25, 30,
40, 50, 60, 75, 80, 90,
100, 125, 150, 175, 200, 225, 250, or 300 mg/kg body weight of the subject
(such as, e.g.,
human, including an adult human). In some instances, the effective amount or
dose is
from about 0.001 milligrams (mg) to about 50 milligrams per kilogram (kg) body
weight
of the subject, including, but not limited to, e.g., from about 0.01 mg/kg to
about 100
mg/kg body weight of the subject (e.g., human), from about 0.01 mg/kg to about
50 mg/kg
body weight of the subject, or from about 0.01 mg/kg to about 25 mg/kg weight
of the
subject; for example, about 0.05 mg/kg, 0.075 mg/kg, 0.1 mg/kg, 0.15 mg/kg,
0.2 mg/kg,
0.25 mg/kg, 0.3 mg/kg, 0.5 mg/kg, 0.75 mg/kg, 1 mg/kg, 1.5 mg/kg, 2 mg/kg, 2.5
mg/kg,
3 mg/kg, 5 mg/kg, about 10 mg/kg, 20 mg/kg, 25 mg/kg, 50 mg/kg, 75 mg/kg or
100
mg/kg body weight of the subject (e.g., adult human patient) is administered
to the subject.
In some instances, the effective amount or dose of the fusion protein dimer is
from about 2
to 10 mg/kg, about 3 to 10 mg/kg, about 3 to 5 mg/kg, about 5 to 10 mg/kg, 0.1
to 5
mg/kg, about 0.05 to 1.0 mg/kg, about 0.05 to 3 mg/kg, about 0.05 to 2.0
mg/kg, about
0.05 to 1.0 mg/kg, about 0.1 to 2.0 mg/kg, about 0.1 to 3.0 mg/kg, about 0.1
to 0.5 mg/kg,
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about 0.1 to 0.8 mg/kg, about 0.1 to 0.6 mg/kg, about 0.01 mg/kg to about 0.05
mg/kg,
about 0.01 mg/kg to about 0.1 mg/kg, about 0.01 mg/kg to about 0.05 mg/kg,
about 0.01
mg/kg to about 1 mg/kg, about 0.01 to about 5 mg/kg, about 0.01 mg/kg to about
3 mg/kg,
about 0.05 mg/kg to about 2.5 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about
0.1 mg/kg
to about 5 mg/kg, about 0.2 to 1 mg/kg, about 0.2 to 0.6 mg/kg, about 0.2 to
0.5 mg/kg
about 0.3 to 1 mg/kg, about 0.3 to 0.6 mg/kg, about 0.3 to 0.5 mg,/kg weight
of a subject.
In some instances, the effective amount or dose is less than about 500 mg for
a subject
weighing less than 60 kg (e.g., less than about 100 mg, 75 mg, 50 mg, 25 mg,
12.5 mg. or
mg), less than about 750 mg for a subject weighing between 60-100 kg (e.g.,
less than
10 about 150 mg, 100 mg, 75 mg, 37.5 mg, or 20 mg), or less than about 1000
mg for a
subject weighing more than 100 kg (e.g., less than about 500 mg, 100 mg, 50
mg, 25 mg,
or 10 mg).
In another aspect, in some such methods of the invention, a mutant CTLA-4-Ig
fusion protein of the invention is administered to the subject in a
therapeutically or
prophylactically effective amount or dose that is, e.g., sufficient to
suppress an immune
response, treat an immune system disease or disorder modulated by interaction
of T cells
with B7-expressing cells, or modulate or inhibit the interaction of T cells
expressing CD28
and/or CTLA-4 with B7-positive cells. The effective amount or dose of the
fusion protein,
which is usually a soluble fusion protein, can comprise from about 0.001 mg/kg
to about
300 mg/kg, about 0.001 mg/kg to about 200 mg/kg, or about 0.001 mg/kg to about
300
mg/kg body weight of the subject (e.g., human). In one aspect, the effective
amount or
dose of the fusion protein comprises from about 0.001 mg/kg to at least about
0.005, 0.01,
0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3,4, 5, 10, 25, 30,
40, 50, 60, 75, 80, 90,
100, 125, 150, 175, 200, 225, 250, or 300 mg/kg body weight of the subject. In
another
aspect, the effective amount or dose is from about 0.01 mg/kg to about 100
mg/kg, from
about 0.01 mg/kg to about 50 mg/kg, or from about 0.01 mg/kg to about 25 mg/kg
weight
of the subject. Exemplary doses or amounts include about 0.05 mg/kg, 0.075
mg/kg, 0.1
mg/kg, 0.15 mg/kg, 0.2 mg/kg, 0.25 mg/kg, 0.3 mg/kg, 0.5 mg/kg, 0.75 mg/kg, 1
mg/kg,
1.5 mg/kg, 2 mg/kg, 2.5 mg/kg, 3 mg/kg, 5 mg/kg, about 10 mg/kg, 20 mg/kg, 25
mg/kg,
50 mg/kg, 75 mg/kg, and 100 mg/kg body weight of the subject (e.g., adult
human). In
another aspect, the effective amount or dose of the fusion protein is from
about 2 to 10
mg/kg, about 3 to 10 mg/kg, about 3 to 5 mg/kg, about 5 to 10 mg/kg, 0.1 to 5
mg/kg,
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about 0.05 to 1.0 mg/kg, about 0.05 to 3 mg/kg, about 0.05 to 2.0 mg/kg, about
0.05 to 1.0
mg/kg, about 0.1 to 2.0 mg/kg, about 0.1 to 3.0 mg/kg, about 0.1 to 0.5 mg/kg,
about 0.1
to 0.8 mg/kg, about 0.1 to 0.6 mg/kg, about 0.01 mg/kg to about 0.05 mg/kg,
about 0.01
mg/kg to about 0.1 nigikg, about 0.01 me/kg to about 0.05 mg/kg, about 0.01
mg/kg to
about 1 mg/kg, about 0.01 to about 5 mg/kg, about 0.01 mg/kg to about 3 mg/kg,
about
0.05 mg/kg to about 2.5 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.1
mg/kg to
about 5 mg/kg, about 0.2 to 1 me/kg, about 0.2 to 0.6 mg/kg, about 0.2 to 0.5
me/kg about
0.3 to 1 mg/kg, about 0.3 to 0.6 mg/kg, about 0.3 to 0.5 mg/kg weight of a
subject. In
some aspects, the effective amount or dose is less than about 500 mg for a
subject
weighing less than 60 kg (e.g., less than about 100 mg, 75 mg, 50 mg, 25 mg,
12.5 mg. or
10 me), less than about 750 mg for a subject weighing between 60-100 kg (e.g.,
less than
about 150 mg, 100 mg, 75 mg, 37.5 mg, or 20 mg), or less than about 1000 mg
for a
subject weighing more than 100 kg (e.g., less than about 500 mg, 100 mg, 50
mg, 25 mg,
or 10 mg).
The effective amount or dose of a nucleic acid, vector, composition, and/or
cell of
the invention sufficient to similarly suppress an immune response or modulate,
treat an
immune system disease or disorder modulated by interaction of T cells with B7-
expressing
cells, or modulate or inhibit the interaction of T cells expressing CD28
and/or CTLA-4
with B7-positive cells can be determined. For example, if a vector encoding
such a fusion
protein dimer of the invention is to be administered to the subject, one
skilled in the art
can readily determine the amount of the vector to be administered such that a
desired
therapeutically or prophylactically effective amount of the fusion protein
dimer is likely
produced in the subject.
Exemplary fusion protein dimers of the invention include any of those
described in
detail above and herein, including, e.g., a fusion protein dimer comprising
two identical
fusion protein monomers, wherein each fusion protein monomer comprises a
mutant
CTLA-4 ECD polypeptide of the invention fused at its C-terminus to the N-
terminus of an
Ig Fc polypeptide (e.g., IgG2 Fc, IgG I, IgG4 or mutant Ig Fc polypeptide
which reduces
effector function). An exemplary mutant CTLA-4 ECD polypeptide is one
comprising a
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73. An
exemplary fusion protein dimer is one comprising two fusion protein monomers,
wherein
each fusion protein monomer comprises a polypeptide sequence selected from the
group
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consisting of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222. Typically, the
two
monomeric fusion proteins in a dimeric fusion protein are covalently linked
together via at
least one disulfide bond formed between cysteine residue(s) present in each
monomer.
In any of the methods described above, the molecule or component of the
invention (e.g., polypeptide (including, e.g., dimeric or monomeric fusion
protein or
polypeptide multimer), conjugate, nucleic acid, vector, composition, and/or
cell of the
invention) may be administered to the subject as a composition. The
composition
typically comprises at least one such molecule or component and an excipient,
carrier, or
diluent. The composition may comprise a pharmaceutical composition comprising
at least
one such molecule or component and a pharmaceutically acceptable excipient,
carrier, or
diluent (e.g., PBS). The pH of compositions of the invention typically ranges
from about
pH 6.0 to about pH 9.0, including, e.g., from about pH 6.5 to about pH 8.5,
usually from
about pH 7.0 to about pH 8Ø In one aspect, the pH of compositions of the
invention
typically ranges from about pH 3 to about pH 10, from about pH 4 to about pH
10, from
about pH 5 to about pH 9, from about pH 6 to about pH 9, from about pH 5.5 to
about pH
8.5, from about pH 6.0 to about pH 6.7, from about pH 6.0 to about pH 6.5,
from about pH
6.2 to about pH 8.7, from about pH 6.5 to about pH 7.5, from about pH 6.2 to
about pH
7.0, from about pH 6.3 to about pH 6.8, from about pH 6.4 to about pH 6.8, and
about pH
7.0 to about pH 7.4. In one aspect, a composition comprising at least one such
molecule
or component of the invention, such as, e.g., a mutant CTLA-4-Ig fusion
protein, has a pH
of pH 5.5, pH 6.0, pH 6.1, pH 6.2, pH 6.3, pH 6.4, pH 6.5, pH 6.6, pH 6.7, pH
6.8, pH 6.9,
pH 7.0, pH 7.1, pH 7.2, pH 7.3, pH 7.4, pH 7.5, pH 7.6, pH 7.7, pH 7.8, pH
7.9, pH 8.0,
pH 8.1, pH 8.2, pH 8.3, pH 8.4, pH 8.5, pH 8.6, pH 8.7, pH 8.8, pH 8.9, pH
9.0, pH 9.1,
pH 9.2, pH 9.3, pH 9.4, pH 9.5, pH 9.6, pH 9.7, pH 9.8, pH, 9.9, or pH 10Ø
Some
compositions of the invention include one or more salts (e.g., sodium
chloride, sodium
phosphate, calcium chloride, and the like), one or more buffers (e.g., HEPES,
sodium
citrate, sodium phosphate (e.g., Na,HPO4/Na3PO4), succinate, tartrate,
fumarate,
gluconate, oxalate, lactate, acetate, tris(hydroxymethyl)aminomethane (Tris),
and the like),
one, two three, four, five, or more saccharides or sugars (e.g., sucrose,
mannose, maltose,
trehalose, dextrose, and the like), and/or one, two, three, four or more
polyalcohols or
sugar alcohols (e.g., mannitol, sorbitol, glycol, glycerol, arabitol,
erythritol, xylitol, ribitol,
lactitol, and the like). One, two three, four, five, or more monosaccharides,
disaccharides
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and/or polysaccharides can be included in the composition. The composition of
the
invention may comprise any concentration of such molecule or component
effective to
suppress an immune response when administered to the subject. For example, in
some
such methods (including, e.g., methods in which inununosuppression is
desirable, such as,
but not limited, to, e.g., treatment of rheumatoid arthritis or similar immune
disorders, Or
for inhibiting rejection of a tissue, cell, graft, or organ transplant from a
donor by a
recipient subject), a pharmaceutical composition comprising a pharmaceutically
acceptable carrier, excipient, or diluent and a fusion protein dimer of the
invention is
administered to the subject (e.g., parentally, subcutaneously, intravenously,
intramuscularly, etc.), wherein the pharmaceutical composition comprises a
fusion protein
dimer of the invention at a concentration of from about 0.001 mg/ml to about
200 mg/ml,
about 0.001 mg/ml to about 300 mg/ml, about 0.01 mg/ml to about 200 mg/ml,
about 0.01
mg/ml to about 250 mg/ml, about 0.1 mg/m1 to about 200 mg/ml, about 0.001
mg/ml to
about 100 mg/ml, about 0.001 mg/m1 to about 90 mg/ml, about 0.01 mg/ml to
about 90
mg/ml, about 0.01 mg/ml to about 75 mg/ml, about 0.1 to about 80 mg/ml, about
0.1 to
about 75 mg/ml, about 0.1 to about 60 mg/ml, about 0.1 to about 50 mg/ml,
about 0.1 to
about 40 mg/ml, about 0.1 to about 30 mg/nil, about 1 to about 90 mg/ml, about
1 to about
80 mg/ml, about 1 to about 75 mg/ml, about 1 to about 60 mg/ml, about 1 to
about 50
mg/ml, about 1 to about 40 mg/ml, about 1 to about 30 mg/ml, about 1 to about
20 mg/ml,
about 1 to about 10 mg/ml, about 1 to about 5 mg/ml, about 5 to about 90
mg/ml, about 5
to about 80 mg/ml, about 5 to about 75 mg/ml. about 5 to about 60 mg/ml. about
5 to
about 50 mg/ml, about 5 to about 40 mg/ml, about 5 to about 30 mg/ml, about 5
to about
20 mg/ml, about 5 to about 10 mg/ml, about 1 to about 5 mg/ml, about 10 to
about 75
mg/ml, about 25 mg/ml to about 75 mg/ml, about 30 mg/ml to about 60 mg/ml,
about 25
to about 50 mg/ml, about 50 mg/ml to about 100 mg/ml, including, e.g., about 1
mg/ml, 5
mg/ml, 10 mg/ml, about 15 mg/ml, about 25 mg/ml, about 30 mg/ml, about 40
mg/ml,
about 50 ms.,/ml, about 60 mg/ml, about 70 mg/ml, about 80 mg/ml, about 90
mg/ml, or
100 mg/ml. Other concentrations are contemplated. In some methods of the
invention
described herein, including some therapeutic or prophylactic methods, a volume
of any
such composition (e.g., pharmaceutical composition) comprising a fusion
protein of the
invention in a range of about 0.01 milliliter (m1) to about 10 ml, about 0.01
ml to about 5
ml, about 0.1 ml to about 5 ml, about 0.5 ml to about 2m1, about 1 ml to about
2 ml,
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including, e.g., a volume of 0.01 ml, 0.025 ml, 0.05 ml, 0.1m1, 0.2 ml. 0.3
ml, 0.4 ml, 0.5
ml, 0.75 ml, 1 ml, 2m1, 3m1, 4 ml, 5 ml. 10 ml. 20m1, 25 ml, 50 ml, 75 ml, 100
ml, 200 ml,
250 ml, 300 ml, 500 ml, 1000 ml, etc. is administered to a subject via a
single i.v., S.C.,
i.m., or i.p. injection. Further details of exemplary compositions of the
invention are
discussed elsewhere herein.
The effective amount or dose of a molecule of the invention that is
administered to
a particular subject may vary depending upon, e.g., the disease, disorder, or
condition
being treated, the potency of the particular mutant CTLA-4 molecule of the
invention (i.e.,
its efficacy) (e.g., a mutant CTLA-4-Ig fusion protein dimer of the invention)
to be
administered, the mode of administration of the molecule, and the subject's
individual
ability to tolerate a specific amount of the particular molecule. For example,
in a method
for suppressing an immune response in a subject having rheumatoid arthritis
(RA) or a
method for treating RA, the effective amount or dose of a mutant CTLA-4-Ig
dimer of the
invention (e.g., D3-29-IGg2, D3-54-IgG2, D3-56-IgG2, D3-69-IgG2, D3-75-IgG2,
etc.) to
be administered to the subject can be determined based on a variety of
factors, including
the potency of the mutant CTLA-4-Ig dimer, the mode of administration of the
dimer,
and/or the severity of the subject's symptoms or signs of rheumatoid
arthritis. In one
aspect, an effective amount or dose of a particular mutant CTLA-4-Ig dimer of
the
invention can be determined by comparing the potency of such mutant CTLA-4-Ig
dimer
with that of the Orencia dimer. Doses of the Orencia dimer effective for
treating
rheumatoid arthritis and related disorders are known in the art. For example,
the Orencia
dimer is typically administered intravenously to a human suffering from
rheumatoid
arthritis in a dose of about 10 mg Orencia per kilogram (kg) body weight of
the human.
A mutant CTLA-4-Ig dimer of the invention that is about "X" times more potent
than
Orencia can be administered (e.g., intravenously, subcutaneously, or in
another manner
described herein) to a human suffering from rheumatoid arthritis in a dose
that is about
"X" times less than the Orencia dimer dose to achieve a therapeutic effect
(e.g.,
suppressing an immune response) that is approximately equivalent to that of
the Orencia
dimer. If a greater therapeutic effect is desired, a proportionally increased
amount or dose
of the mutant CTLA-4-Ig dimer can be readily determined and administered to
the human.
In any of the methods described herein, the molecule or component of the
invention (e.g., a polypeptide (including, e.g., dimeric or monomeric fusion
protein or
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polypeptide multimer), conjugate, nucleic acid, vector, composition, and/or
cell of the
invention) can be administered parentally, subcutaneously, or intravenously,
or as
described elsewhere herein. The molecule or component of the invention may be
administered in a therapeutically effective amount one, two, three or four
times per month,
two times per week, biweekly (every two weeks), or bimonthly (every two
months).
Administration may last for a period of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or
12 months or
longer (e.g., one, two, three, four or more years, including for the life of
the subject).
Any of the methods described herein may further comprise administering to the
subject an effective amount of at least one additional therapeutic or
immunosuppressive
agent or compound. Thus, for example, the invention provides a method of
suppressing an
immune response comprising administering to a subject in need thereof (1) an
effective
amount of at least one first immunosuppressive agent, wherein each such first
immunosuppressive agent is a polypeptide, nucleic acid, vector, composition,
and/or cell
of the invention, and (2) an effective amount of at least one second
immunosuppressive
agent, wherein an immune response in the subject is suppressed.
A variety of additional therapeutic or immunosuppressive agents (that are not
molecules of the invention) may be used or administered in conjunction with a
molecule
of the invention (e.g., polypeptide, nucleic acid, vector, composition, and/or
cell of the
invention). Such agents include, e.g., a disease-modifying anti-rheumatic drug
(DMARD)
(such as, e.g., methotrexate (MTX), cytoldne antagonist (e.g., IL-2 or IL-6
antagonist),
steroidal compound (e.g., corticosteroid, glucocosteroid, e.g., prednisone or
methylprednisone), non-steroidal compound, sodium or magnesium salicylate,
ibuprofen,
acetylsalicylic acid, acetaminophen, antibody, biological agent that blocks
synthesis of an
production anti-inflammatory cytokine, Raptiva efalizumab, anti-inflammatory
agent or
compound, and non-steroidal anti-inflammatory drug (NSA1D). Such additional
therapeutic or immunosuppressive agent can be administered to the subject in a
pharmaceutical composition comprising the additional agent and a
pharmaceutically
acceptable excipient or carrier. The effective amount or dose of the agent to
be
administered will depend upon the specific agent. Some such agents are
currently used in
immunosuppressive therapies and appropriate dosages can be determined by based
upon
the disease, disorder or condition being treated and the subject's ability to
tolerate specific
amounts or doses, and the agent's immunosuppressive effectiveness. Exemplary
doses for
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immunosuppressive agents described above which are not molecules of the
invention are
known. The additional immunosuppressive agent that is not a molecule of the
invention
can be administered simultaneously with or before or after administration of
the molecule
of the invention (e.g., mutant CTLA-4-Ig fusion protein).
A treatment regimen, including, e.g., dose, schedule of administration, method
of
administration (e.g., intravenous injection, subcutaneous injection, etc.) and
pharmaceutical composition comprising at least one such molecule or component
of the
invention may vary depending upon the disease, disorder or condition to be
treated. One
or more such molecules or components of the invention may be administered to a
subject;
each such molecule or component need not be administered in the same
pharmaceutical
formulation, by the same administration methods, in the same amount, or by the
same
dosing frequency schedule.
In some such methods, for example, about 1 ml of a pharmaceutical composition
comprising a pharmaceutically acceptable excipient, carrier, or diluent and a
concentration
of a fusion protein dimer of the invention of about 50 mg/ml is administered
subcutaneously to a subject (e.g., adult human) in need of immunosuppression
(e.g., a
subject suffering from rheumatoid arthritis). Such initial dose is 50 mg of
fusion protein
dimer. For a subject having a body weight of 100 kg, this initial dose
corresponds to 0.5
mg fusion protein dimer per kg body weight of the subject. A second of the
same amount
is administered subcutaneously at one or two weeks after the first dose.
Further doses are
administered subcutaneously every week, biweekly, or once per month, or more
or less
frequently as necessary. Such compositions and administration formats are
believed
useful, for example, for treating a human suffering from rheumatoid arthritis
or another
immune disorder in which immunosuppression is desirable or for inhibiting
rejection of a
tissue, cell, graft, or organ transplant from a human donor by a human
recipient.
Methods of Treating Rheumatoid Arthritis
Rheumatoid arthritis is one of the most common systemic inflammatory
autoimmune diseases and is estimated to affect 1-2% of the adult population.
See, e.g.,
Dipiro, J.T., Rheumatoid arthritis, in PHARMACOTHERAPY: A PATHOPHYS1OLOGIC
APPROACH, 1671-1682 (Talbert, R.T. et al. eds., McGraw-Hill, New York, 6th ed.
2005).
The disease is characterized by synovial membrane hyperplasia and infiltration
of
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inflammatory cells, including activated T cells. Activated T cells play a
pivotal role in the
progression of rheumatoid arthritis by stimulating a variety of cell types to
produce
proinflammatory cytokines, such as IL-1, IL-6, and TNF-alpha, autoantibodies,
and matrix
metalloproteinases (Hoffman, R.W., Front. Biosci. 6:1369-1378 (2001); Choy,
E.K. et al.,
N. Engl. J. Med 344:907-916 (2001)). The strong contribution of T cells to the
progression of rheumatoid arthritis makes T cell activation a rational target
for therapeutic
intervention. Such inflammatory molecules are believed to cause the
inflammatory
response, tissue damage (e.g., joint damage), and pain associated with
rheumatoid arthritis.
Co-stimulation of T cells mediated by interactions between CD28 receptor and
CD80 and/or CD86 ligand(s) is essential for the activation of most T cells
(Riley, J.L. et
al., Blood 105:13-21(2005)). Therapeutic or prophylactic agents that
antagonize the
CD80/CD86 ¨ CD28 co-stimulation pathway, such as the Orencia (Abatacept)
fusion
protein, which is a soluble dimeric hCTLA-4-Ig fusion protein, have been shown
to be
clinically effective in the treatment of rheumatoid arthritis (Kremer, J.M. et
al., Ann.
Intern. Med. 144:865-876 (2006); Genovese, M.C. et al., N. Engl. J. Med.
353:1114-1123
(2005)). Abatacept is believed to exert immunosuppressive function by binding
to CD80
and/or CD86 ligands on antigen-presenting cells when administered to a subject
(e.g.,
adult human) in vivo in a therapeutically or prophylactically effective
amount, thus
preventing the interaction of either or both of these ligands with the CD28
receptor on T
cells.
Abatacept is presently approved to treat adult human patients with moderately
to
severely active RA who have had an inadequate response to one or more DMARDs,
such
as methotrexate or TNF antagonists. Abatacept is administered to an adult RA
patient at a
dose of 10 mg/kg body weight of the subject by intravenous infusion. Following
the first
dose, second and third doses of 10 mg/kg of the fusion protein are
administered to the
subject at two and four weeks, respectively, after the first dose. Subsequent
doses are
administered every four weeks (i.e., once per month). Intravenous infusion of
Abatacept
is believed necessary to deliver the high dose level required to obtain
desirable efficacy in
rheumatoid arthritis therapy.
Other current therapies for rheumatoid arthritis include the administration of
non-
specific immunosuppressive agents, such as methotrexate, and steroidal and non-
steroidal
anti-inflammatory drugs. Additionally, biologic agents are approved that
target specific
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pro-inflammatory cytokines, such as TNF-o. (e.g.. Remicade infliximab.
EnbrelO
entaercept, Humira adalimumab) and IL-1 (e.g., Kineret anakinra). However,
many of
these therapies have significant side effects ¨ some of which are toxic ¨
particularly when
administered over a long time period.
Despite the availability of various therapies, significant unmet need exists
for the
treatment of RA. For example, 60% of human RA patients who have failed
previous
DMARD treatment and 80% of human RA patients who have failed previous anti-TNF
therapy did not achieve an ACR50 scores after treatment with Orencia for 6
months
(Kremer J.M. et al., Ann. Intern. Med. 144:865-876 (2006); Genovese, M.C. et
al., N.
Engl. J. Med. 353:1114-11 (2005)). Dose response studies using Abatacept and
Belatacept (LEA29Y-Ig) fusion protein in the treatment of RA in adults
indicated that
efficacy was dose-dependent and was not saturated at the highest dose levels
tested
(Kremer, J.M. et al., N. Engl. J. Med. 349:1907-1915(2003); Moreland, L.W. et
al.,
Arthrit. Rheum. 46:1470-1479 (2002)).
A soluble dimeric mutant CTLA-4-Ig of the invention having a higher binding
avidity to hCD80 and/or hCD86 than Abatacept is expected to be able to exert
more potent
immunosuppressive effects than Abatacept when administered to a subject with
RA. Such
a mutant CTLA-4-Ig binds a similar number of CD80 and/or CD86 li.gands at a
lower
concentration than Abatacept.
A mutant CTLA-4-Ig with a higher binding avidity to CD80 or CD86 and slower
dissociation rate from CD80 or CD86, respectively, has a longer residence time
on such
ligand. This longer residence time is expected to be associated with higher
efficacy in
vivo. It is believed that such a mutant CTLA-4-Ig may be effective in
therapeutically or
prophylactically treating a subject with RA at a dose that is lower than the
Abatacept.
That is, it is believed that such a mutant CTLA-4-Ig may achieve a degree of
efficacy
equivalent to that of Abatacept when administered to the RA subject at a dose
that is less
than that of the Abatacept dose of 10 mg/kg body weight of the subject. The
invention
provides soluble dimeric mutant CTLA-4-Ig fusion proteins of varied binding
avidities to
hCD80 and/or hCD86. Soluble dimeric mutant CTLA-4-Ig fusion proteins that have
substantially higher binding avidities to hCD86 than Abatacept may a degree of
efficacy
equivalent to that of Abatacept when administered to the RA subject at a dose
that is
substantially less than that of Abatacept. Administration of a lower dose of
such a mutant
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CTLA-4-Ig may allow a more convenient method of administration (e.g.,
subcutaneous
injection) to be used than is currently used for administration of Abatacept
(intravenous
injection).
It is also believed that a soluble mutant CTLA-4-Ig fusion protein of the
invention
with a higher immunosuppressive potency than Abatacept or Belatacept fusion
protein
would enable a higher level of efficacy to be obtained in the treatment of RA
patients. A
more immunosuppressive mutant CTLA-4-Ig is expected to be able to alleviate
symptoms
associated with RA and inhibit progressive of the deleterious physical effects
of RA more
effectively than Abatacept. Such a mutant CTLA-4-Ig can be formulated in a
pharmaceutically acceptable diluent, excipient, or carrier (e.g., PBS) at a
concentration
ranging from of 0.1 ¨ 200 mg/nil. Treatment of a subject with RA can be
accomplished by
administering to the subject a therapeutically or prophylactically effective
amount (dose)
of the mutant CTLA-4-Ig by subcutaneous injection or intravenous infusion at
an
appropriately determined dosing frequency (e.g., initial dose following by one
dose 2 to 4
times per month, one dose per month, or one dose every two months). The dose
would
depend upon the severity of the subject's disease or symptoms. For example, an
amount
or dose of a mutant CTLA-4-Ig of no more than about 10 mg/kg (including e.g.,
about 1
mg/kg, 0.5 mg/kg, 0.25 mg/kg, 1 mg/kg, 2 mg/kg, 3 mg/kg, 4 mg/kg, 5 mg/kg, 6
mg/kg, 7
mg/kg, 8 mg/kg, or 9 mg/kg) body weight of the subject may be administered. A
more
immunosuppressive mutant CTLA-4-Ig may allow for a less frequent dosing
schedule
(e.g., once very two months) than the dosing schedule typically used with
Abatacept.
Alternatively, an amount or dose of a mutant CTLA-4-Ig greater than about 10
mg/kg
weight of the subject (e.g., from about 10 ma/kg to about 100 mg/kg, from
about 10 mg/kg
to about 25 mg/kg, about 10 mg/kg to about 50 mg/kg, about 10 mg/kg to about
75 mg/kg,
etc., including, e.g., about 15 mg/kg, 20 mg/kg, 30 mg/kg, 40 mg/kg, 50 ma/kg,
60 g/kg,
70 mg/kg, 75 mg/kg, 80 mg/kg, 90 mg/kg, 100 mg/kg) may be administered to a
subject
with RA if the subject's disease condition and/or symptoms warrants such
amount or dose.
The effective amount or dose of a mutant CTLA-4-Ig dimer of the invention for
treating RA in a human suffering therefrom can be determined based on various
factors,
such as the potency of the mutant CTLA-4-Ig dimer, the mode of administration
of the
dimer, and/or the severity of the subject's symptoms or signs of rheumatoid
arthritis. For
example, an effective amount or dose of a mutant CTLA-4-Ig dimer of the
invention can
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be ascertained by comparing the potency of such dimer to that of the Orencia0
dimer and
determining the amount or dose of the mutant CTLA-4-Ig dimer that would yield
the
desired immunosuppressive effect compared to Orencia0 (e.g., an improved or
approximately equivalent effect) based on amount or dose of Orencia that
would
typically be administered to a human subject exhibiting similar symptoms or
signs of RA.
In one embodiment, for example, the invention provides a method of treating
rheumatoid arthritis in a subject in need of such treatment, the method
comprising
administering to the subject an effective amount of a soluble dimeric mutant
CTLA-4-Ig
fusion protein of the invention by, e.g., intravenous or subcutaneous
injection. The
effective amount or dose may comprise from about 0.001 milligrams (mg) to
about 10
milligrams per kilogram (kg) body weight of the subject, including, but not
limited to, e.g.,
from about 0.01 mg/kg to about 10 mg/kg weight of the subject, from about 0.05
mg/kg,
0.1 mg/kg, 0.2 mg/kg, 0.25 mg/kg, 0.3 mg/kg, 0.5 mg/kg, 1 mg/kg, 2 mg/kg, 5
mg/kg, 6
mg/kg, 7 mg/kg, 8 mg/kg, 9 mg/kg, or 10 mg/kg body weight of the adult human
patient is
administered to the subject. In some instances, the effective amount or dose
is from about
2 to 10 mg/kg, about 3 to 10 mg/kg, about 3 to 5 mg/kg, about 5 to 10 mg/kg,
0.1 to 5
mg/kg weight, about 0.05 to 1.0 mg/kg, about 0.05 to 3 mg/kg weight, about
0.05 to 2.0
mg/kg, about 0.05 to 1.0 mg/kg, about 0.05 to 2.0 mg/kg, about 0.1 to 2.0
mg/kg, about
0.1 to 3.0 mg/kg, about 0.1 to 0.5 mg/kg, about 0.1 to 0.8 mg/kg, about 0.1 to
0.6 mg/kg,
about 0.2 to 1 mg/kg, about 0.2 to 0.6 mg/kg, about 0.2 to 0.5 mg/kg about 0.3
to 1 mg/kg,
about 0.3 to 0.6 mg/kg, about 0.3 to 0.5 mg/kg weight of a subject. In some
instances, the
effective amount or dose is less than about 500 mg for a subject weighing less
than 60 kg
(e.g., less than about 100 mg, 75 mg, 50 mg, 25 mg, or 12.5 mg), less than
about 750 mg
for a subject weighing between 60-100 kg (e.g., less than about 150 mg, 100
mg, 75 mg,
37.5 mg. or 20 mg), or less than about 1000 mg for a subject weighing more
than 100 kg
(e.g., less than about 500 mg, 100 mg, 50 mg, 25 mg, or 10 mg). Following the
first dose,
subsequent equivalent doses are administered at intervals of 1, 2, 4, 8, 10,
12, 14, or 16
weeks. Subsequent dosing frequency can be determined as needed.
Such a mutant CTLA-4-Ig fusion may be formulated with a pharmaceutically
acceptable excipient, carrier, or diluent to produce a pharmaceutical
composition suitable
for administration to a subject (e.g., mammal, including a human). The
concentration of
the fusion protein in the composition may range from about 0.01 mg/ml to about
300
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mg/ml or from about 0.01 mg/ml to about 200 mg/ml, including, but not limited
to, e.g.,
from about 0.1 mg/ml to about 300 mg/ml, from about 0.1 mg/ml to about 200
mg/ml,
about 0.1 mg/ml to about 100 mg/ml, about 0.5 mg/ml to about 100 mg/ml, about
0.5
mg/ml to about 50 mg/ml, about 1 to about 100 mg/ml, about Ito about 75 mg/ml,
about 5
to about 75 mg/ml, about 10 to about 75 mg/ml, about 10 to about 60 mg/ml,
about 25 to
about 60 mg/ml, about 30 to about 60 mg/ml, about 25 to about 50 mg/ml, about
40 to
about 50 mg/ml, about 25 mg/ml, or about 50 mg/ml. Other compositions,
including those
discussed above and below, are also contemplated.
Such treatment is expected to reduce one or more signs and/or symptoms
associated with rheumatoid arthritis, such as, e.g., inflammation, joint
tenderness, joint
swelling, pain, and stiffness, in the subject. Such treatment may reduce the
further
progression of the disease in the patient. For example, such treatment may
reduce the
progression of structural damage in the patient. Such treatment may improve
physical
functioning of the subject.
Methods of Inhibiting Tissue, Cell, Graft, or Organ Transplantation Rejection
In another aspect, the invention provides a method of inhibiting rejection of,
or
suppressing an immune response associated with, a tissue, cell, skin graft, or
organ
transplant from a donor by a recipient subject, the method comprising
administering to the
recipient subject a therapeutically effective amount of one or more of the
following: (1) a
polypeptide of the invention (e.g., mutant CTLA-4-ECD polypeptide or dimeric
or
monomeric mutant CTLA-4-1g fusion protein); (2) a multimer comprising one of
more
polypeptides of the invention (e.g., a dimer comprising any two such
polypeptides or a
tetramer comprising any four such polypeptides); (3) a conjugate comprising at
least one
polypeptide of the invention; (4) a nucleic acid of the invention (e.g., a
nucleic acid
encoding a polypeptide of the invention); (5) a vector comprising a nucleic
acid of the
invention or encoding a polypeptide of the invention; (6) a cell or population
of cells
comprising a polypeptide, nucleic acid, conjugate, and/or vector of the
invention; and/or
(7) a composition of the invention, thereby inhibiting rejection of the
tissue, cell, skin
graft, or organ transplant by the recipient subject. The donor and recipient
may be the
same species or different species. The donor or recipient may be a mammal,
such as a
human, non-human primate (e.g., monkey, gorilla), sheep, cat, dog, pig, cow,
horse, etc.
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In some such methods, the polypeptide, conjugate, vector, and/or cell of the
invention is
administered to the recipient subject prior to, simultaneously with, or after
tissue, cell, skin
graft, or organ transplantation. The effective amount typically comprises from
about
0.001 mg/kg weight of the subject to about 200 mg/kg body weight of the
subject. In
some such methods, for example, the effective amount comprises from about
0.001
milligrams per kilogram (mg/kg) weight of the subject to at least about 0.005,
0.01, 0.05,
0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 10, 25, 50, 75,
100, 125, 150, 175,
200, 225, 250, or 300 milligrams per kilogram (mg/kg) body weight of the
subject. In
some such methods, the effective amount comprises from about 0,001 milligrams
per
kilogram (mg/kg) weight of the subject to at least about 0.005, 0.01, 0.05,
0.1, 0.2, 0.5, 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 25, 50, or 75 milligrams per kilogram (mg/kg)
body weight of
the subject. The polypeptide, conjugate, nucleic acid, vector, and/or cell of
the invention
may be administered to the recipient subject during, prior to, or immediately
after the
transplantation. Alternatively or additionally, such molecule of the invention
may be
administered one or more hours after transplantation, on the day following
transplantation,
and/or daily thereafter, or at least once per week, at least once every two
weeks, or at least
one per month after transplantation, as necessary, for up to 12, 24, or 36 or
more months
or longer as needed. The organ transplant may involve any organ, such as,
e.g., a kidney,
liver, heart, or lung.
The effective amount or dose of a mutant CTLA-4 molecule of the invention
(e.g.,
mutant CTLA-4-Ig fusion protein dimer) to be administered to an organ, tissue,
or cell
transplant recipient subject so as to inhibit transplant rejection (or
suppress an immune
response associated with such transplant) is typically determined based on the
potency of
such molecule, mode of administration, the type of transplantation (e.g.,
cell, tissue,
organ), the subject's history, and/or the severity of the transplant recipient
subject's
symptoms or signs of an immune response(s) suggestive of transplant rejection.
For
example, an effective amount or dose of a mutant CTLA-4-Ig dimer of the
invention (e.g.,
D3-29-IGg2, D3-54-IgG2, D3-56-IgG2, D3-69-IgG2, D3-75-IgG2 dimer, etc.) can be
determined by comparing the potency of such dimer with that of the Belatacept
dimer.
Effective doses of Belatacept useful for preventing or suppressing an immune
response
associated with kidney/renal transplantation are known. For example,
Belatacept is
administered by intravenous infusion to a human following kidney
transplantation in the
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human from a kidney donor in an amount or dose of about 5 mg or 10 mg per
kilogram
body weight of the human per month. A mutant CTLA-4-Ig dimer of the invention
that is
about "X" times more potent than Belatacept can be administered (e.g.,
intravenously,
subcutaneously, or in another manner described herein) to a human who has had
kidney
transplant in an amount or dose that is about "X" times less than the
Belatacept dose to
achieve a therapeutic effect (e.g., suppressing an immune response)
approximately
equivalent to that of Belatacept. If a greater therapeutic effect is desired,
a proportionally
increased amount or dose of the CTLA-4-Ig fusion protein dimer of the
invention can be
determined and administered.
In another aspect, the invention provides a method of treating tissue, cell,
or organ
transplant rejection (e.g., solid organ transplant rejection (e.g., kidney,
liver, lung, heart,
etc.)) in a subject who receives such tissue, cell, or organ from a donor, the
method
comprising administering to the recipient a therapeutically effective amount
of at least one
polypeptide, conjugate, nucleic acid, vector, ancUor cell of the invention,
thereby inhibiting
rejection of the donor tissue, cell, or organ transplant by the recipient
subject. The
polypeptide, conjugate, nucleic acid, vector, and/or cell of the invention can
be
administered to the subject prior to, simultaneously with, or after cell,
tissue or organ
transplantation.
In one aspect, the invention provides a method of inhibiting rejection of
islet cell
transplantation from a donor in a recipient subject in need thereof, the
method comprising
administering to the subject an effective amount or dose of a mutant CTLA-4
molecule of
the invention (e.g., mutant CTLA-4-Ig fusion protein) prior to, simultaneously
with, or
after transplantation of islet cell(s) from the pancreas of a donor into the
subject. The
subject (e.g., human) typically suffers from diabetes (e.g., IDDM) and such
method is
useful in treating a subject diagnosed with or suffering from diabetes. Islet
transplantation
procedures are known in the art. Typically, islets are removed from the
pancreas of a
deceased organ donor, purified and processed, and implanted into a recipient
subject
suffering from diabetes. After transplantation, the beta cells in the islets
begin to make
and release insulin, thereby reducing the recipient subject's need for
insulin.
In such methods of inhibiting transplant rejection, the mutant CTLA-4 molecule
of
the invention (e.g., mutant CTLA-4-Ig) can be formulated with a
pharmaceutically
acceptable excipient, carrier, or diluent to produce a pharmaceutical
composition suitable
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for administration to a subject (e.g., mammal, including a human). Some such
methods
comprise administration of a pharmaceutical composition comprising a
pharmaceutically
acceptable excipient, carrier, or diluent and a mutant CTLA-442 dimer of the
invention
having a concentration of from about 0.01 mg/ml to about 300 mg/ml or about
0.01 mg/ml
to about 200 mg/ml, including, but not limited to, e.g., from about 0.1 mg/ml
to about 300
mg/ml, from about 0.1 mg/ml to about 200 mg/ml, about 0.1 mg/m1 to about 100
mg/ml.
about 0.5 mg/ml to about 100 mg/ml, about 0.5 mg/ml to about 50 mg/ml, about 1
to about
100 mg/ml, about 1 to about 75 mg/ml, about 5 to about 75 mg/ml, about 10 to
about 75
mg/ml, about 10 to about 60 mg/ml, about 25 to about 60 mg/ml, about 30 to
about 60
mg/ml, about 25 to about 50 mg/ml, about 40 to about 50 mg/ml, about 25 mg/ml,
or about
50 mg/ml. Other compositions, including those discussed above and below, are
also
contemplated.
Methods of Inhibiting an Immune Response
In another aspect, the invention includes the use of a polypeptide (including,
e.g., a
dimeiic or monomeric fusion protein or multimeric polypeptide), conjugate,
nucleic acid,
vector, or cell of the invention for the manufacture of a medicament for
inhibiting or
suppressing an immune response in a mammal (e.g., human or non-human primate).
Immune responses that may be suppressed include, e.g., T cell activation or
proliferation,
cytokine synthesis or production, induction of activation markers, synthesis
or production
of inflammatory molecules, inflammation, anti-collagen Ab production, T cell-
dependent
Ab response.
The invention also includes the use of a polypeptide (including, e.g., a
dimeric or
monomeric fusion protein or multimeric polypeptide), conjugate, nucleic acid,
vector, or
cell of the invention for the manufacture of a medicament for the treatment of
an immune
system disease or disorder. The immune system disease or disorder may be one
that is
mediated by interaction of T cells with CD80-positive cells and/or CD86-
positive cells in
a mammal. The immune system disease or disorder may be an immune system
disease or
disease, such as a rheumatic disease or disorder or an autoinimune disease or
autoinimune
disorder. Such immune system disease or disorder may be or involve, e.g., but
is not
limited to, Addison's Disease, Allergy, Alopecia Areata, Alzheimer's.
Antineutrophil
cytoplasmic antibodies (ANCA)-as sociated vasculitis, Ankylosing Spondylitis,
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Antiphospholipid Syndrome (Hughes Syndrome), arthritis, Asthma,
Atherosclerosis,
Atherosclerotic plaque, autoimmune disease (e.g., lupus, RA, MS, Graves'
disease, etc.),
Autoimmune Hemolytic Anemia, Autoimmune Hepatitis, Autoimmune inner ear
disease,
Autoimmune Lymphoproliferative syndrome, Autoimmune Myocarditis, Autoimmune
Oophoritis, Autoimmune Orchitis, Azoospermia, Behcet's Disease, Behcet's
syndrome,
Berger's Disease, Bullous Pemphigoid, Cardiomyopathy, Cardiovascular disease,
Celiac
Sprue/Coeliac disease, Chronic Fatigue Immune Dysfunction Syndrome (CFIDS),
Chronic
idiopathic polyneuritis, Chronic Inflammatory Demyelinating,
Polyradicalneuropathy
(CIPD), Chronic relapsing polyneuropathy (Guillain-Barr6 syndrome), Churg-
Strauss
Syndrome (CSS), Cicatricial Pemphigoid, Cold Agglutinin Disease (CAD), COPD,
CREST syndrome, Crohn's Disease, Dermatitis, Herpetiformus, Dermatomyositis,
diabetes, Discoid Lupus, Eczema, Epidermolysis bullosa acquisita, Essential
Mixed
Cryoglobulinemia, Evan's Syndrome, Exophthalmos, Fibromyalgia, Goodpasture's
Syndrome, graft-related disease or disorder, Graves' Disease, GVHD,
Hashimoto's
Thyroiditis, Idiopathic Pulmonary Fibrosis, Idiopathic Thrombocytopenia
Purpura (ITP),
IgA Nephropathy, immunoproliferative disease or disorder (e.g., psoriasis),
Inflammatory
bowel disease (IBD), Insulin Dependent Diabetes Mellitus (IDDM), Interstitial
lung
disease, juvenile diabetes, Juvenile Arthritis, juvenile idiopathic arthritis
(JIA),
Kawasaki's Disease, Lambert-Eaton Myasthenic Syndrome, Lichen Planus, lupus,
Lupus
Nephritis, Lymphoscytic Lypophisitis, Meniere's Disease, Miller Fish
Syndrome/acute
disseminated encephalomyeloradiculopathy, Mixed Connective Tissue Disease,
Multiple
Sclerosis (MS), muscular rheumatism, Myalgic encephalomyelitis (ME),
Myasthenia
Gravis, Ocular Inflammation, Pemphigus Foliaceus, Pemphigus Vulgaris,
Pernicious
Anaemia, Polyarteritis Nodosa, Polychondritis, Polyglandular Syndromes
(Whitaker's
syndrome), Polymyalgia Rheumatica, Polymyositis, Primary Agammaglobulinemia,
Primary Biliary Cirrhosis/Autoimmune cholangiopathy, Psoriasis, Psoiiatic
arthritis,
Raynaud's Phenomenon, Reiter's Syndrome/Reactive arthritis, Restenosis,
Rheumatic
Fever, rheumatic disease, Rheumatoid Arthritis, Sarcoidosis, Schmidt's
syndrome,
Scleroderma, Sjorgen's Syndrome, Solid-organ transplant rejection (kidney,
heart, liver,
lung, etc.), Stiff-Man Syndrome, Systemic Lupus Erythematosus (SLE), systemic
sclerodenna, Takayasu Arteritis, Temporal Arteritis/Giant Cell Arteritis,
Thyroiditis, Type
I diabetes, Type 2 diabetes, Ulcerative colitis, Uveitis, Vasculitis,
Vitiligo, Wegener's
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Ciranulomatosis, and preventing or suppressing an immune response associated
with
rejection of a donor tissue, cell, graft, or organ transplant by a recipient
subject.
The invention also provides for the use of a polypeptide, conjugate, nucleic
acid,
vector, or cell of the invention for the manufacture of a medicament for
inhibiting
interaction of CD80-positive cells and/or CD86-positive cells with CD28-
positive and/or
CTLA-4-positive T cells. In another aspect, the invention includes the use of
a
polypeptide, conjugate, nucleic acid, vector, or cell of the invention for the
manufacture of
a medicament for the treatment of a tissue or organ transplant rejection
(e.g., solid organ
transplant rejection (e.g., kidney, lung, liver, heart, etc.)) in a mammal.
Assessing Immune Responses
Immune responses suppressed by a polypeptide, nucleic acid, vector, virus,
pseudovirus, VLP, or composition of the invention can be measured by any
suitable
technique. Examples of useful techniques in assessing humoral immune responses
include
flow cytometry, immunoblotting assays, immunohistochemistry assays,
immunoprecipitation assays, radioimmunoassays (RIA), and enzyme immunoassays.
Enzyme immunoassays include enzyme-linked immunoflow assays (ELIFA) and enzyme-
linked immunosorbent assays (ELISA), including sandwich ELISA and competitive
ELISA assays. HPLC and capillary electrophoresis (CE) also can be utilized in
immunoassays to detect complexes of antibodies and target substances. General
guidance
performing such techniques and related principles are described in, e.g.,
Harlow and Lane
(1988) ANTIBODIES, A LABORATORY MANUAL, Cold Spring Harbor Publications, New
York, Hampton R et al. (1990) SEROLOGICAL METHODS A LABORATORY MANUAL, APS
Press, St. Paul Minn., Stevens (1995) CLINICAL IMMUNOLOGY AND SEROLOGY: A
LABORATORY PERSPECTIVE, CRC press, Bjerrum (1988) HANDBOOK OF IMMUNOBLOTTING
OF PRO EEINS. V01.2, Zoa (1995) DIAGNOSTIC IMMUNOPATHOLOGY: LABORATORY
PRACTICE AND CLINICAL APPLICATION, Cambridge University Press, Folds (1998)
CLINICAL DIAGNOSTIC IMMUNOLOGY: PROTOCOLS IN QUALITY ASSURANCE AND
STANDARDIZATION, Blackwell Science Inc., Bryant (1992) LABORATORY IMMUNOLOGY &
SEROLOGY 3rd edition, W B Saunders Co., and Maddox D E et al. (1983) J. Exp.
Med.
158:1211. Guidance with respect to ELISA techniques and related principles are
described in, e.g., Reen (1994) Methods Mol. Biol. 32:461-6, Goldberg et al.
(1993) Cliff.
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Opin. Immunol. 5(2):278-81, Voller et al. (1982) Lab. Res. Methods Biol. Med.
5:59-81,
Yolken et al. (1983) Ann. NY Acad. Sci. 420:381-90, Vaughn et al. (1999) Am.
J. Trop.
Med. Hy.c.r. 60(4):693-8, and Kuno et al. (1991) J. Virol. Methods 33(1-2):101-
13.
Guidance with respect to flow cytometry techniques is provided in, e.g.,
Diamond (2000)
IN LIVING COLOR : PROTOCOLS IN FLOW CYTOMETRY AND CELL SORTING, Springer
Verlag,
Jaroszeki (1998) FLOW CYTOMETRY PROTOCOLS, 1st Ed., Shapiro (1995) PRACTICAL
FLOW CYTOMETRY, 3rd edition, Rieseberg et al. (2001) Appl. Microbiol.
Biotechnol. 56(3-
4):350-60, Scheffold and Kern (2000) J. Clin. Immunol. 20(6):400-7, and
McShany
(1994) Clin. Microbiol. Rev. (4):576-604.
Cytotoxic and other T cell immune responses also can be measured by any
suitable
technique. Examples of such techniques include ELISpot assay (particularly.
IFN-gamma
ELISpot), intracellular cytokine staining (ICC) (particularly in combination
with FACS
analysis), CD8+ T cell tetramer staining/PACS, standard and modified T cell
proliferation
assays, chromium release CTL assay, limiting dilution analysis (LDA), and CTL
killing
assays. Guidance and principles related to T cell proliferation assays are
described in, e.g.,
Plebanski and Burtles (1994) J. Immunol. Meth. 170:15, Sprent et al. (2000)
Philos. Trans.
R. Soc. Lond. B Biol. Sci. 355(1395):317-22 and Messele et al. (2000) Clin.
Diagn. Lab.
Immunol. 7(4):687-92. LDA is described in, e.g., Shan-ock et al. (1990)
Immunol. Today
11:281-286. ELISpot assays and related principles are described in, e.g.,
Czerinsky et al.
(1988) J. Immunol. Meth. 110:29-36, Olsson et al. (1990) J. Clin. Invest.
86:981-985,
Schmittel et al. (2001) J. Immunol. Meth. 247(1-2):17-24, Ogg and McMichael
(1999)
Immunol. Lett. 66(1-3):77-80, Schmittel et al. (2001) J. Immunol. Meth. 247(1-
2):17-24,
Kurane et al. (1989) J. Exp. Med. 170(3):763-75. Chain et al. (1987) J.
Immunol. Meth.
99(2):221-8, Czerkinsky et al. (1988) J. Immunol. Meth. 110:29-36. and U.S.
Patent Nos.
5,750,356 and 6,218,132. Tetramer assays are discussed in, e.g., Skinner et
al. (2000) J.
Immunol. 165(2):613-7. Other T cell analytical techniques are described in
Hanel et al.
(1999) Scand. J. Immunol. 49(6):649-54 and Parish et al. (1983) J. Immunol.
Meth. 58(1-
2):225-37.
T cell activation also can be analyzed by measuring CTL activity or expression
of
activation antigens such as IL-2 receptor, CD69 or HLA-DR molecules.
Proliferation of
purified T cells can be measured in a mixed lymphocyte reaction (MLR) assay;
such
assays are well-known in the art.
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ELISpot assays measure the number of T-cells secreting a specific cytokine,
such
as IFN-7 or TNF-a, which serves as a marker of T-cell effectors. Cytokine-
specific
ELISA kits are commercially available (e.g., an 1PN-7-specific ELISPot is
available
through R&D Systems, Minneapolis, MN).
Additional methods for assessing and measuring the ability of molecules of the
invention (e.g., polypeptides of the invention, including, e.g., soluble
mutant CTLA-4-Ig
fusion proteins of the invention) to suppress or inhibit T cell activation
and/or T cell
proliferation are described in Examples 5-8 in the Examples section below.
Methods of Administration
In any of the methods described herein, an injectable pharmaceutical
composition
comprising a suitable pharmaceutically acceptable excipient or carrier (e.g.,
PBS) and an
effective amount of a molecule of the invention, such as a polypeptide (e.g.,
mutant
CTLA-4 ECD or monomeric, dimeric, or multimeric mutant CTLA-4-Ig) or conjugate
of
the invention, can be administered parenterally, intramuscularly,
intraperitoneally,
intravenously, subdermally, transdermally, subcutaneously, or intradermally to
a host.
Alternatively, biolistic protein delivery techniques (vaccine gun delivery)
can be used
(examples of which are discussed elsewhere herein). Any other suitable
technique also
can be used. Polypeptide administration can be facilitated via liposomes. Any
such
delivery technique can be used to deliver a polypeptide or conjugate of the
invention in
conjunction with any therapeutic or prophylactic method described herein.
While the following discussion is primarily directed to nucleic acids, it will
be
understood that it applies equally to nucleic acid vectors of the invention. A
nucleic acid
of the invention or composition thereof can be administered to a host by any
suitable
administration route. In some aspects of the invention, administration of the
nucleic acid
is parenteral (e.g., subcutaneous (s.c.), intramuscular (i.m.), or intradermal
(i.d.)), topical,
or transdeimal. The nucleic acid can be introduced directly into a tissue,
such as muscle,
by injection using a needle or other similar device. See, e.g., Nabel et al.
(1990), supra;
Wolff et al. (1990) Science 247:1465-1468), Robbins (1996) Gene Therapy
Protocols,
Humana Press, NJ, and Joyner (1993) Gene Targeting: A Practical Approach, IRL
Press,
Oxford, England, and U.S. Patent Nos. 5,580,859 and 5,589,466. Other methods
such as
"biolistic" or particle-mediated transformation (see, e.g., U.S. Patent Nos.
4,945,050 and
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5,036,006, Sanford et al., J. Particulate Sci. Tech. 5:27-37 (1987). Yang et
al., Proc. Natl.
Acad. Sci. USA 87:9568-72 (1990), and Williams et al., Proc. Natl. Acad. Sci.
USA
88:2726-30 (1991)). These methods are useful not only for in vivo introduction
of DNA
into a subject, such as a mammal, but also for ex vivo modification of cells
for
reintroduction into a mammal (which is discussed further elsewhere herein).
For standard gene gun administration, the vector or nucleic acid of interest
is
precipitated onto the surface of microscopic metal beads. The microprojectiles
are
accelerated with a shock wave or expanding helium gas, and penetrate tissues
to a depth of
several cell layers. For example, the AccelTM Gene Delivery Device
manufactured by
Agacetus, Inc. Middleton WI is suitable for use in this embodiment. The
nucleic acid or
vector can be administered by such techniques, e.g., intramuscularly,
intradermally,
subdermally, subcutaneously, and/or intraperitoneally. Additional devices and
techniques
related to biolistic delivery Int'l Patent Appn. Pub!. Nos. WO 99/2796, WO
99/08689,
WO 99/04009, and WO 98/10750, and U.S. Patent Nos. 5,525,510, 5,630,796,
5,865,796,
and 6,010,478.
The nucleic acid can be administered in association with a transfection-
facilitating
agent, examples of which were discussed above. The nucleic acid can be
administered
topically and/or by liquid particle delivery (in contrast to solid particle
biolistic delivery).
Examples of such nucleic acid delivery techniques, compositions, and
additional
constructs that can be suitable as delivery vehicles for the nucleic acids of
the invention
are provided in, e.g., U.S. Patent Nos. 5,591,601, 5,593,972, 5,679,647,
5,697,901,
5,698,436, 5,739,118, 5,770,580, 5,792,751, 5,804,566, 5,811,406, 5,817,637,
5,830,876,
5,830,877, 5,846,949, 5,849,719, 5,880,103, 5,922,687, 5,981,505, 6,087,341,
6,107,095,
6,110,898, and Int'l Pat. Appn. Pub!. Nos. WO 98/06863, WO 98/55495, and WO
99/57275.
Alternatively, the nucleic acid can be administered to the host by way of
liposome-
based gene delivery. Exemplary techniques and principles related to liposome-
based gene
delivery is provided in, e.g., Debs and Zhu (1993) WO 93/24640; Mannino and
Gould-
Fogerite (1988) BioTechniques 6(7):682-691; Rose U.S. Pat No. 5,279,833;
Brigham
(1991) WO 91/06309; Brigham et al. (1989) Am. J. Med. Sci. 298:278-281; Nabel
et al.
(1990) Science 249:1285-1288; Hazinski et al. (1991) Am. J. Resp. Cell Molec.
Biol.
4:206-209; and Wang and Huang (1987) Proc. Natl. Acad. Sci. USA 84:7851-7855),
and
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Feigner et al. (1987) Proc. Nat! Acad. Sci. USA 84:7413-7414). Suitable
liposome
pharmaceutically acceptable compositions that can be used to deliver the
nucleic acid are
further described elsewhere herein.
Any amount of nucleic acid of the invention can be used in the methods of the
invention. For example, sufficient nucleic acid may be formulated in a
pharmaceutically
acceptable excipient or carrier and administered to a subject such that the
encoded
polypeptide or conjugate is produced in the subject in an amount believed
effective to, for
example, suppress immune response in the subject, inhibit interaction between
endogenous B7-positive cells and CD28-positive cells in the subject, or
inhibit rejection of
a tissue, cell, organ, or graft transplant. In one format, where the nucleic
acid is
administered by injection, about 50 micrograms (n) to 100 mg nucleic acid is
administered. In one exemplary application, to suppress an immune response, a
pharmaceutical composition comprising PBS and an amount of a DNA vector that
encodes
an effective amount of a mutant CTLA-4 polypeptide is administered by
injection or
electroporation or other suitable delivery method (e.g., gene gun, impressing
through the
skin, and lipofection) to a subject in need of treatment (e.g., a subject
suffering from an
immune system disease or disorder in which immunosuppressive treatment is
desirable).
An exemplary vector is shown in Figure 1.
The amount of DNA plasmid for use in the methods of the invention where
administration is via a gene gun, e.g., is often from about 100 to about 1000
times less
than the amount used for direct injection (e.g., via standard needle
injection). Despite
such sensitivity, at least about 1 i.tg of the nucleic acid may be used in
such biolistic
delivery techniques.
RNA or DNA viral vector systems can be useful for delivery nucleic acids
encoding polypeptides of the invention. Viral vectors can be administered
directly to a
subject in vivo or they can be used to treat cells in vitro and the modified
cells are
administered to the subject in an ex vivo format. Useful viral vectors include
those
discussed above, such as adeno-associated, adenoviral, retroviral, lentivirus,
and herpes
simplex virus vectors. With such viral vectors, a nucleic acid of the
invention can be
readily transferred into target cells and tissues of the subject.
Additionally, with the
retrovirus, lentivirus, and adeno-associated virus gene transfer methods, a
nucleic acid of
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the invention can be integrated into the host genome may be possible, thereby
resulting in
continuing expression of the inserted nucleic acid.
Delivery of a viral vector of the invention comprising at least one nucleic
acid of
the invention to a subject is believed capable of suppressing an immune
response in the
subject to whom the vector is administered. Optionally, some prophylactic
and/or
therapeutic methods of the invention are practiced with a dosage of a suitable
viral vector
sufficient to inhibit a detectable immune response. Any suitable viral vector
comprising a
nucleic acid of the invention, in any suitable concentration, can be used to
suppress the
immune response. For example, to the subject host can be administered a
population of
retroviral vectors (examples of which are described in, e.g., Buchscher et al.
(1992) J.
Virol. 66(5) 2731-2739, Johann et al. (1992) J. Virol. 66 (5):1635-1640
(1992),
Sommerfelt et al., (1990) Virol. 176:58-59, Wilson et al. (1989) J. Virol.
63:2374-2378,
Miller et al., J. Virol. 65:2220-2224 (1991), Wong-Staal et al.,
PCT/US94/05700,
Rosenburg and Fauci (1993) in FUNDAMENTAL ImMuNOLOGY, THIRD EDITION Paul (ed.)
Raven Press, Ltd., New York and the references therein), an AAV vector (as
described in.
e.g., West et al. (1987) Virology 160:38-47, Kotin (1994) Human Gene Therapy
5:793-
801, Muzyczka (1994) J. Clin. Invest. 94:1351, Tratschin et al. (1985) Mol.
Cell. Biol.
5(11):3251-3260, U.S. Patent Nos. 4,797,368 and 5,173,414, and Int'l Patent
Appn Publ.
No. WO 93/24641), or an adenoviral vector (as described in, e.g., Berns et al.
(1995) Ann.
NY Acad. Sci. 772:95-104; Ali et al. (1994) Gene Ther. 1:367-384; and Haddada
et al.
(1995) Curr. Top. Microbiol. Immunol. 199 ( Pt 3):297-306), such that
immunosuppressive levels of expression of the nucleic acid included in the
vector result,
thereby resulting in the desired immunosuppressive response. Other suitable
types of viral
vectors are described elsewhere herein (including alternative examples of
suitable
retroviral, AAV, and adenoviral vectors).
Suitable infection conditions for these and other types of viral vector
particles are
described in, e.g., Bachrach et al., J. Virol., 74(18), 8480-6 (2000), Mackay
et al., J. Virol.,
19(2), 620-36 (1976), and FIELDS VIROLOGY, supra. Additional techniques useful
in the
production and application of viral vectors are provided in, e.g., "Practical
Molecular
Virology: Viral Vectors for Gene Expression" in METHODS IN MOLECULAR BIOLOGY,
vol.
8, Collins, M. Ed., (Humana Press 1991), VIRAL VECTORS: BASIC SCIENCE AND GENE
THERAPY, 1st Ed. (Cid-Arregui et al., Eds.) (Eaton Publishing 2000), "Viral
Expression
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Vectors," in CURRENT TOPICS IN MICROBIOLOGY AND IMMUNOLOGY, Oldstone et al.,
Eds.
(Springer-Verlag, NY, 1992), and "Viral Vectors" in CURRENT COMMUNICATIONS IN
BIOTECHNOLOGY, Gluzman and Hughes, eds. (Cold Spring Harbor Laboratory Press,
1988).
The toxicity and therapeutic efficacy of vectors or viruses that include one
or more
molecules of the invention are determined using standard pharmaceutical
procedures in
cell cultures or experimental animals. One can determine the MLD50 (the
minimum dose
lethal to 50% of the population) and/or the ED50 (the dose therapeutically
effective in 50%
of the population) using procedures presented herein and those otherwise known
in the art.
See also S. Plotkin and W. Orenstein, VACCINES (W. B. Saunders Co. 1999 3d
ed.) for
suggested doses for known viral vaccines. Nucleic acids, polypeptides,
proteins, fusion
proteins, transduced cells and other formulations of the present invention can
be
administered in an amount determined, e.g., by the MLD50 of the formulation,
and the
side-effects thereof at various concentrations, as applied to the mass and
overall health of
the patient. Thus, for example, the invention provides a method of inducing an
immune
response by administering a dose equal or greater to the ED50 of a
pharmaceutically
acceptable composition comprising a population of virus-like particles or
viruses (e.g.,
attenuated or replication-deficient virus) that comprises a polypeptide or
nucleic acid of
the invention. Administration can be accomplished via single dose or divided
doses
(either by co-administration, serial administration, or combinations thereof).
Administration techniques and protocols are described in, e.g., Plotkin
(VACCINES) supra
and other references cited herein. In a related sense, techniques for
assessing dosage of
the nucleic acid, polypeptide, vector, and cell compositions effective for
inducing
immunity are described in, e.g., European Patent Appn No. 1 156 333 and
references cited
therein.
The viral vector can be targeted to particular tissues, cells, and/or organs
of a
subject, e.g., mammal. Examples of such vectors are described above. For
example, the
viral vector or nucleic acid vector can be used to selectively deliver the
nucleic acid
sequence of the invention to monocytes, dendritic cells, cells associated with
dendritic
cells (e.g., keratinocytes associated with Langerhans cells), T-cells, and/or
B-cells. The
viral vector can be a replication-deficient viral vector. The viral vector
particle also can be
modified to reduce host immune response to the viral vector, thereby achieving
persistent
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gene expression. Such "stealth- vectors are described in, e.g.. Martin, Exp.
Mol. Pathol.
66(1):3-7 (1999), Croyle et al., J. Virol. 75(10):4792-801 (2001), Rollins et
al., Hum.
Gene Ther. 7(5):619-26 (1996), Ikeda et al., J. Virol. 74(10):4765-75 (2000),
Halbert et
al., J. Virol. 74(3):1524-32 (2000), and Int'l Patent Appn Publ. No. WO
98/40509.
Alternatively or additionally, the viral vector particles can be administered
by a strategy
selected to reduce host immune response to the vector particles. Strategies
for reducing
immune response to the viral vector particle upon administration to a host are
provided in,
e.g., Maione et al., Proc. Natl. Acad. Sci. USA 98(11):5986-91 (2001), Morral
et al., Proc.
Natl. Acad. Sci. USA 96(22):2816-21 (1999), Pastore et al., Hum. Gene Then
10(11):1773-81 (1999), Morsy etal., Proc. Natl. Acad. Sci. USA 95(14):7866-71
(1998),
Joos etal., Hum. Gene Ther. 7(13):1555-66 (1996), Kass-Eisler et al., Gene
Ther.
3(2):154-62 (1996), U.S. Patent Nos. 6,093,699, 6,211,160, 6,225,113, U.S.
Patent
Application Pub!. No. 2001-0066947A1.
The skin and muscle are generally preferred targets for administration of the
polypeptides, conjugates, nucleic acids, and vectors of the invention, by any
suitable
technique. Thus, the delivery of a polypeptide, conjugate, nucleic acid, or
vector of the
invention into or through the skin of a subject (e.g., mammal), is a feature
of the invention.
Such molecules of the invention can be administered in a pharmaceutically
acceptable
injectable solution into or through the skin, e.g., intramuscularly, or
intraperitoneally.
Administration can also be accomplished by transdermal devices, or, more
typically,
biolistic delivery of the polypeptide, conjugate, nucleic acid, and/or vector
to, into, or
through the skin of the subject or into exposed muscle of the subject.
Transdermal devices
provided by the invention, described elsewhere herein, for example, can be
applied to the
skin of a host for a suitable period such that sufficient transfer of a
polynucleotide and/or
vector to the subject occurs, thereby suppressing an immune response in the
subject or
inhibiting rejection of a graft, cell, or tissue transplant. Muscular
administration is more
typically facilitated by injection of a liquid solution comprising a
polypeptide,
polynucleotide, or vector of the invention. Particular cells that can be
targeted include
dendritic cells, other APCs, B cells, monocytes, T cells (including T helper
cells), and
cells associated with such immune system cells (e.g., keratinocytes or other
skin cells
associated with Langerhans cells). Targeting of vectors and nucleic acids of
the invention
is described elsewhere herein. Such targeted administration can be performed
with nucleic
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acids or vectors comprising nucleic acids operably linked to cell and/or
tissue-specific
promoters, examples of which are known in the art.
The polynucleotide of the invention can be administered by any suitable
delivery
system, such that expression of a recombinant polypeptide occurs in the host
resulting in
an suppression of an immune response, inhibition of interaction between B7-
positive cells
and CD28-positive, or inhibition of tissue, cell, organ, or graft transplant
rejection. For
example, an effective amount of a population of bacterial cells comprising a
nucleic acid
of the invention can be administered to a subject, resulting in expression of
a recombinant
mutant CTLA-4 polypeptide of the invention, and suppression of an immune
response in
the subject. Bacterial cells developed for mammalian gene delivery are known
in the art.
Administration of a polynucleotide or vector of the invention to a subject is
facilitated by application of electroporation to an effective number of cells
or an effective
tissue target, such that the nucleic acid and/or vector is taken up by the
cells, and
expressed therein, resulting in production of a recombinant polypeptide of the
invention
therein and subsequent suppression of an immune response in the subject.
PRODUCTION AND PURIFICATION METHODS
The invention further provides methods of making and purifying the
polypeptides,
nucleic acids, vectors, and cells of the invention. In one aspect, the
invention provides a
method of making a recombinant polypeptide of the invention by introducing a
nucleic
acid of the invention into a population of cells in a culture medium,
culturing the cells in
the medium (for a time and under conditions suitable for desired level of gene
expression)
to produce the polypeptide, and isolating the polypeptide from the cells,
culture medium,
or both. The nucleic acid is typically operatively linked to a regulatory
sequence effective
to express the polypeptide encoded by the nucleic acid.
The polypeptide can be isolated from cell lysates, cell supernatants, and/or
cell
culture medium a variety of suitable techniques known in the art, including,
e.g., various
chromatography of cell lysates and/or cell supernatants. For example, the
polypeptide can
be isolated from cell lysates and/or cell culture medium by first
concentrating the culture
medium using centrifugal filters (Amicon), alternatively, by precipitating the
polypeptides
with ammonium sulfate or polyethylene glycol and then resuspending the
polypeptides in
PBS or other suitable buffers. The polypeptide can then be purified using
either size-
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exclusion chromatography on Sephacryl S-400 column (Amersham Biosciences) as
described in, e.g., Hjorth, R. and J. Moreno-Lopez, J. Virol. Methods 5:151-
158 (1982), or
another affinity chromatography, or by centrifugation through 20-60% sucrose
gradients
as described in, e.g., Konish et al., Virology 188:714-720 (1992). Fractions
containing the
desired polypeptides can be identified by ELISA or SDS-PAGE followed by
protein silver
stain and immunoblotting. The desired fractions are pooled and further
concentrated.
Sucrose in gradient centrifugation fractions can be removed using PD-10 column
(Amersham Biosciences) gel filtration. Additional purification techniques
include those
described in the Examples below and hydrophobic interaction chromatography
(Diogo, M.
M, et al., J. Gene Med. 3:577-584 (2001)), and any other suitable technique
known in the
art.
Any suitable purification technique that is known in the art can also be used.
Polypeptide purification methods known in the art include those set forth in,
e.g., Sandana
(1997) BIOSEPARATION OF PROTEINS, Academic Press, Inc., Bollag et al. (1996)
PROTEIN
METHODS, 2nd Edition Wiley-Liss, NY, Walker (1996) THE PROTEIN PROTOCOLS
HANDBOOK Humana Press, NJ, Han-is and Angal (1990) PROTEIN PURIFICATION
APPLICATIONS: A PRACTICAL APPROACH IRL Press at Oxford, Oxford, England,
Scopes
(1993) PROTEIN PURIFICATION: PRINCIPI ES AND PRACTICE 3rd Edition Springer
Verlag,
NY, Janson and Ryden (1998) PROTEIN PURIFICATION: PRINCIPLES, HIGH RESOLUTION
METHODS AND APPLICATIONS, Second Edition Wiley-VCH, NY; and Walker (1998)
PROTEIN PROTOCOLS ON CD-ROM Humana Press, NJ. Cells suitable for polypeptide
production are known in the art and are discussed elsewhere herein (e.g., Vero
cells, 293
cells, BHK, CHO (e.g., CHO-K1), and COS cells can be suitable). Cells can be
lysed by
any suitable technique including, e.g., sonication, microfluidization,
physical shear,
French press lysis, or detergent-based lysis.
In one aspect, the invention provides a method of purifying a polypeptide of
the
invention, which comprises transforming a suitable host cell with a nucleic
acid of the
invention (e.g., a recombinant nucleic acid that encodes a recombinant
polypeptide
comprising the polypeptide sequence of SEQ ID NO:1) in the host cell (e.g., a
CHO cell or
293 cell), lysing the cell by a suitable lysis technique (e.g., sonication,
detergent lysis, or
other appropriate technique), and subjecting the lysate to affinity
purification with a
chromatography column comprising a resin that includes at least one novel
antibody of the
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invention (usually a monoclonal antibody of the invention) or antigen-binding
fragment
thereof, such that the lysate is enriched for the desired polypeptide (e.g., a
polypeptide
comprising the polypeptide sequence of SEQ ID NO:1).
In another aspect, the invention provides a method of purifying such target
polypeptides, which method differs from the above-described method in that a
nucleic acid
comprising a nucleotide sequence encoding a fusion protein that comprises a
polypeptide
of the invention (e.g., SEQ ID NO:1) and a suitable tag (e.g., an e-
epitope/his tag), and
purifying the polypeptide by immunoaffinity, lentil-lectin affinity column
chromatography, immobilized metal affinity chromatography (IMAC), or metal-
chelating
affinity chromatography (MCAC) enrichment techniques. Additional purification
methods are disclosed elsewhere herein.
In another aspect, the invention provides a method of producing a polypeptide
of
the invention, which method comprises introducing into a population of cells a
recombinant expression vector comprising a nucleic acid of the invention,
culturing the
cells in a culture medium under appropriately sufficient conditions for
expression of the
nucleic acid from the vector and production of the polypeptide encoded by the
nucleic
acid, and isolating the polypeptide from the cells, culture medium, or both.
The cells
chosen are based on the desired processing of the polypeptide and based on the
appropriate vector (e.g., E. coli cells are preferred for bacterial plasmids,
whereas 293
cells are preferred for mammalian shuttle plasmids and/or adenoviruses,
particularly El-
deficient adenoviruses).
In yet another aspect, the invention includes a method of producing a
polypeptide,
the method comprising: (a) introducing into a population of cells a
recombinant expression
vector comprising at least one nucleic acid of the invention the encodes a
polypeptide of
the invention; (b) administering the expression vector into a mammal; and (c)
isolating the
polypeptide from the mammal or from a byproduct of the mammal.
A polypeptide of the invention can also be produced by culturing a cell or
population of cells of the invention (which, e.g., have been transformed with
a nucleic acid
of the invention that encodes such polypeptide) under conditions sufficient
for expression
of the polypeptide and recovering the polypeptide expressed in or by the cell
using
standard techniques known in the art.
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In another aspect, the invention provides a method of producing a polypeptide
of
the invention, which comprises (a) introducing into a population of cells a
nucleic acid of
the invention, wherein the nucleic acid is operatively linked to a regulatory
sequence
effective to produce the polypeptide encoded by the nucleic acid; (b)
culturing the cells in
a culture medium to produce the polypeptide; and (c) isolating the
polypeptide from
the cells or culture medium. Also included is a cultured cell into which has
been
introduced a vector of the invention (e.g., an expression vector of the
invention).
Also included is a method of producing a polypeptide of the invention which
comprises introducing a nucleic acid encoding said polypeptide into a
population of cells
in a medium, which cells are permissive for expression of the nucleic acid,
maintaining the
cells under conditions in which the nucleic acid is expressed, and thereafter
isolating the
polypeptide from the medium.
In another aspect, the invention provides a method of making a fusion protein.
The
method comprises; (1) culturing a host cell transformed with a nucleic acid in
a culture
medium, wherein the nucleic acid comprises: (i) a first nucleotide sequence
that encodes a
polypeptide having at least 95% identity to a polypeptide sequence selected
from the
group consisting of SEQ ID NOS:1-73, which polypeptide binds CD86 and/or CD80,
and/or an extracellular domain of either CD86 or CD80, and (ii) a second
nucleotide
sequence encoding an Ig Fc polypeptide comprising a hinge region, CH2 domain,
and
CH3 domain, whereby the nucleic acid is expressed and a fusion protein is
produced; and
(2) recovering the fusion protein. Any Ig Fc polypeptide may be any employed,
including
e.g., an IgG1 Fc, IgG2 Fc, IgG4 Fc, or mutant Ig Fc polypeptide. In some such
methods,
the nucleic acid further comprises a third nucleotide sequence that encodes a
secretory or
signal peptide operably linked to the fusion protein, and the fusion protein
is secreted from
the host cell as a disulfide-bonded fusion protein dimer comprising identical
first and
second fusion proteins, and the disulfide-bonded fusion protein dimer is
recovered from
the culture medium. In some such methods, the disulfide-bonded fusion protein
dimer is
formed via a covalent disulfide bond between a cysteine residue of the first
fusion protein
and a cysteine residue of the second fusion protein. In some such methods, the
fusion
protein is recovered from the culture medium, host cell, or host cell
periplasm.
In another aspect, the invention provides an isolated or recombinant nucleic
acid
molecule comprising a nucleotide sequence which encodes (i) a first
polypeptide
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comprising a polypeptide sequence having at least 95% sequence identity to at
least one
polypeptide sequence selected from the group consisting of SEQ ID NOS:1-73,
wherein
the first polypeptide binds CD80 and/or CD86 and/or an extracellular domain of
either or
both. and (ii) a second polypeptide comprising a comprising a hinge region,
CH2 domain,
and CH3 domain of an IgG polypeptide. The second polypeptide may comprise any
suitable Ig polypeptide discussed elsewhere herein, including, e.g., that
comprising the
polypeptide sequence of SEQ ID NO:184 or SEQ ID NO:218.
In another aspect, the invention provides a method of making a soluble fusion
protein dimer. The method comprises culturing a host cell transformed with an
expression
vector comprising a nucleotide sequence that encodes a soluble fusion protein
dimer of the
invention. Exemplary fusion proteins include those comprising the polypeptide
sequence
of any of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222. The vector includes
a
nucleotide sequence that facilitates expression of the fusion protein (e.g., a
nucleotide
sequence encoding a signal peptide). The fusion protein is secreted from the
host cell as a
disulfide-bonded fusion protein dimer comprising two identical fusion
proteins, and the
disulfide-bonded fusion protein dimer is recovered from the culture medium. In
some
such methods, the disulfide-bonded fusion protein dimer is formed via a
covalent disulfide
bond between a cysteine residue on each fusion protein. The fusion protein
dimer is
typically recovered from the culture medium, host cell, or host cell
periplasm. Example
12 provides an exemplary procedure for creating a stably transfected cell line
expressing a
mutant CTLA4-Ig fusion protein of the invention, producing the mutant CTLA4-Ig
fusion
protein, and the purifying the mutant fusion protein from culture.
In addition to recombinant production, the polypeptides of the invention may
be
produced by direct peptide synthesis using solid-phase techniques (see, e.g.,
Stewart et al.
(1969) SOLID-PHASE PEPTIDE SYNTHESIS, W.H. Freeman Co, San Francisco and
Merrifield
J. (1963) J. Am. Chem. Soc. 85:2149-2154). Peptide synthesis may be performed
using
manual techniques or by automation. Automated synthesis may be achieved, for
example,
using Applied Biosystems 431A Peptide Synthesizer (Perkin Elmer, Foster City,
Calif.) in
accordance with the instructions provided by the manufacturer. For example,
subsequences may be chemically synthesized separately and combined using
chemical
methods to produce a polypeptide of the invention or fragments thereof.
Alternatively,
synthesized polypeptides may be ordered from any number of companies that
specialize in
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production of polypeptides. Most commonly, polypeptides of the invention are
produced
by expressing coding nucleic acids and recovering polypeptides, e.g., as
described above.
The invention includes a method of producing a polypeptide of the invention
comprising introducing a nucleic acid of the invention, a vector of the
invention, or a
combination thereof, into an animal, such as a mammal (including, e.g., rat,
nonhuman
primate, bat, marmoset, pig, or chicken), such that a polypeptide of the
invention is
expressed in the animal, and the polypeptide is isolated from the animal or
from a
byproduct of the animal. Isolation of the polypeptide from the animal or
animal byproduct
can be by any suitable technique, depending on the animal and desired recovery
strategy.
For example, the polypeptide can be recovered from sera of mice, monkeys, or
pigs
expressing the polypeptide of the invention. Transgenic animals (including the
aforementioned mammals) comprising at least one nucleic acid of the invention
are
provided by the invention. The transgenic animal can have the nucleic acid
integrated into
its host genome (e.g., by an AAV vector, lentiviral vector, biolistic
techniques performed
with integration-promoting sequences, etc.) or can have the nucleic acid in
maintained
epiclu-omosomally (e.g., in a non-integrating plasmid vector or by insertion
in a non-
integrating viral vector). Epichromosomal vectors can be engineered for more
transient
gene expression than integrating vectors. RNA-based vectors offer particular
advantages
in this respect.
COMPOSITIONS
The invention further provides novel and useful compositions comprising at
least
one component of the invention, such as, e.g., at least one polypeptide
(including, e.g.,
fusion proteins and multimeric polypeptides), conjugate, nucleic acid, vector,
virus, virus-
like particle (VLP), and/or cell of the invention, or any combination thereof
and a carrier,
excipient, or diluent. The carrier, excipient or diluent may be a
pharmaceutically
acceptable carrier, excipient, or diluent. Such a composition can comprise any
suitable
amount of any suitable number of polypeptides, conjugates, nucleic acids,
vectors, viruses,
VLPs, and/or cells of the invention. Also provided are pharmaceutical
compositions
comprising at least one polypeptide, conjugate, nucleic acid, vector, virus,
VLP, and/or
cell, or any combination thereof, and a pharmaceutically acceptable carrier,
excipient, or
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diluent. Such compositions are useful in the methods of the invention
described herein,
including, e.g., methods of suppressing immune responses.
For example, in one non-limiting embodiment, the invention provides a
composition comprising an excipient, diluent, or carrier and at least one such
polypeptide
of the invention (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more polypeptides),
such as a mutant
CTLA-4 ECD polypeptide (e.g., any of SEQ ID NOS:1-73) or mutant CTLA-4-Ig
fusion
protein (e.g., any of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222),
wherein the at
least one polypeptide is present in the composition in an amount effective to
suppress an
immune response, including, e.g., an immune response(s) involved in transplant
rejection
and/or autoinu-nunity, inhibit rejection of a donated tissue, cell, or organ
transplant, or
inhibit interaction of endogenous B7-positive cells with CD28-positive T cells
in a subject
to whom the composition is administered.
Also included is a pharmaceutical composition comprising a pharmaceutically
acceptable excipient, diluent, or carrier and an effective amount of one or
more such
components of the invention. The effective amount may be a therapeutically or
prophylactically effective amount or dose for use in a therapeutic or
prophylactic method
described elsewhere herein, such as a method of treating an autoimmune disease
or a
method of inhibiting rejection of a tissue, cell, graft, or organ transplant
from a donor by a
recipient subject.
The composition (or pharmaceutical composition) can be any non-toxic
composition that does not interfere with the immunosuppressive properties of
the
polypeptide, conjugate, nucleic acid, vector, virus, VLP, or cell of the
invention included
therein. The composition can comprise one or more excipients, diluents, or
carriers, and
the pharmaceutical composition comprises one or more pharmaceutically
acceptable
excipients, diluents, or carriers. A wide variety of acceptable carriers,
diluents, and
excipients are known in the art and can be included in the compositions and
pharmaceutical compositions of the invention. For example, a variety of
aqueous carriers
can be used, e.g., distilled or purified water, sterile saline, buffered
saline, such as
phosphate-buffered saline (PBS), and the like are advantageous in injectable
formulations
of the polypeptide, fusion proteins, conjugate, nucleic acid, vector, virus,
VLP, and/or cell
of the invention. Numerous suitable excipients, carriers, and diluents for
administration of
therapeutic proteins are known in the art. Such solutions are preferably
sterile and
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generally free of undesirable matter. Compositions may be sterilized by
conventional,
well-known sterilization techniques. Compositions of the invention may
comprise
pharmaceutically acceptable auxiliary substances, as required, to approximate
physiological conditions. Such substances include, e.g., pH adjusting agents,
buffering
agents, and tonicity adjusting agents, including, e.g., sodium acetate, sodium
ascorbate,
sodium chloride, potassium chloride, calcium chloride, sodium lactate, and the
like.
Compositions of the invention, including pharmaceutical compositions, can also
include
one or more components, such as diluents, fillers, salts, buffers,
surfactants, emulsifiers,
detergents (e.g., a nonionic detergent or emulsifier, such as Tween0-20.
Tween0-40,
Tween0-60, Tween0-80, pluronic F-68, and the like), stabilizers (e.g., sugars
or protein-
free amino acids), preservants, tissue fixatives, solubilizers, and/or other
materials,
suitable for inclusion in a pharmaceutically composition.
Examples of suitable components that may be used in the pharmaceutical
composition are described in, e.g., Berge et al., J. Pharm. Sci. 66(1):1-19
(1977), Wang
and Hanson, J. Parenteral. Sci. Tech. 42:S4-S6 (1988), U.S. Patent Nos.
6,165,779 and
6,225,289, and elsewhere herein. Pharmaceutical compositions also can include
preservatives (such as benzyl alcohol, sodium azide, m-cresol, etc.),
antioxidants, metal
chelators (such as methionine, EDTA, etc.), and/or other additives known to
those of skill
in the art. Examples of suitable pharmaceutically acceptable carriers for use
in the
pharmaceutical compositions are described in, e.g., Urquhart et al., Lancet
16:367 (1980),
Lieberman et al., PHARMACEUTICAL DOSAGE FORMS - DISPERSE SYSTEMS (2nd ed.,
Vol. 3,
1998), Ansel et al., PHARMACEUTICAL DOSAGE FORMS & DRUG DELIVERY SYSTEMS (7th
ed. 2000), Martindale, THE EXTRA PHARMACOPEIA (31st edition), Remington' S
PHARMACEUTICAL SCIENCES (16th-20th editions), THE PHARMACOLOGICAL BASIS OF
THERAPEUTICS, Goodman and Gilman, Eds. (9th ed. - 1996), WILSON AND GISVOLDS
TEXTBOOK OF ORGANIC MEDICINAL AND PHARMACEUTICAL CHEMISTRY, Delgado and
Remers, Eds. (10th ed. - 1998), and U.S. Patent Nos. 5,708,025 and 5,994,106.
Principles
of formulating pharmaceutically acceptable compositions are described in,
e.g., Platt, Clin.
Lab Med. 7:289-99 (1987), Aulton, PHARMACEUTICS: THE SCIENCE OF DOSAGE FORM
DESIGN, Churchill Livingstone (New York) (1988), EXTEMPORANEOUS ORAL LIQUID
DOSAGE PREPARATIONS, CSHP (1998), and "Drug Dosage," J. Kans. Med. Soc.
70(1):30-
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32 (1969). Additional pharmaceutically acceptable carriers particularly
suitable for
administration of vectors are described in, e.g., Int'l Patent Appn Publ. No.
WO 98/32859.
Compositions of the invention, including pharmaceutical compositions, can
include one or more aqueous carriers or excipients (including, e.g.,
pharmaceutically
__ acceptable carriers or excipients) and one or more components, such as one
or more
buffers, one or more salts, one or more detergents or emulsifiers, and/or one
or more
sugars. The buffer system is typically one suitable to maintain the pH of the
composition
within a range which is conducive to the stability of the molecule of the
invention present
in the composition (e.g., mutant CTLA-4-Ig). Exemplary buffers for use in the
__ composition include, but are not limited to, e.g., N-2-
hydroxyethylpiperazine-N'-2-
aminoethane sulfonic acid (HEPES) buffer, citrate buffer (e.g., disodium
citrate-trisodium
citrate mixture, sodium citrate-citric acid mixture, citric acid-trisodium
citrate mixture,
monosodium citrate-disodium citrate mixture, citric acid-monosodium citrate
mixture),
sodium phosphate buffer (e.g., disodium phosphate-trisodium phosphate mixture
__ (Na2HPO4/Na3PO4), sodium dibasic phosphate-sodium monobasic phosphate
mixture),
acetate buffer (e.g., acetic acid-sodium acetate mixture, acetic acid-sodium
hydroxide
mixture), histidine buffer, Tris buffer, Tris-maleate buffer, succinate buffer
(e.g., succinic
acid-sodium hydroxide mixture, succinic acid-monosodium succinate mixture,
succinic
acid-disodium succinate mixture, monosodium succinate-disodium succinate
mixture),
__ maleate buffer, imidazole buffer, tartrate buffer, fumarate buffer,
gluconate buffer, oxalate
buffer, lactate buffer, acetate buffer, and the like, or a combination of any
thereof (e.g.,
cocktail of citrate and acetate buffers, etc.). The concentration of buffer in
the
composition can be any that is appropriate for the molecule(s) of the
invention (e.g., a
mutant CTLA-4-Ig) included in the composition solution, such as, but not
limited to, e.g.,
__ in the range of from about I mM to about 100 mM, about 1 mM to about 50 mM,
about 5
mM to about 50 mM, or about 5 mM to about 25 mM, including, e.g., 1 mM, 5 mM,
10
mM, 15 mM, 20 mM, 25 mM, 30 mM, 40 mM, 50 mM (such as, e.g., 20 mM HEPES
buffer, 20 mM disodium citrate-trisodium citrate buffer, 20 mM succinate
buffer, etc.).
Exemplary salts for use in the composition include, but are not limited to,
e.g.,
__ water-soluble salts, including an organic salt or inorganic salt (e.g.,
water-soluble
inorganic salt), such as sodium chloride, magnesium chloride, sodium
bicarbonate,
potassium chloride, calcium chloride, and ammonium chloride, and the like, or
any
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pharmaceutically acceptable or physiologically compatible salt. Exemplary
concentrations
of salt in the composition solution include, but are not limited to, e.g., in
the range of from
about 1 mM to about 150 mM, about 10 mM to about 125 mM, or about 75 mM to
about
125 mM, including. e.g., 10 mM. 50 mM, 75mM, 100 mM, 125 mM, 150 mM (such as.
e.g., 100 mM NaC1).
Exemplary sugars or carbohydrates for use in the composition include, but are
not
limited to, e.g., sucrose, maltose, trehalose, dextrose, mannose, raffinose,
lactose, malto
dextrin, dextran, saccharose, etc., in a concentration range including, but
not limited to,
e.g., from about 0.1% to about 10% by weight sugar, about 1% to about 5% by
weight
sugar, or about 1% to about 3% by weight sugar, including e.g., 0.1%, 0.5%,
1%, 1.5%,
2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% by weight sugar (e.g., 2% by
weight
sucrose, 2% by weight trehalose, or 2% by weight mannose) based on the
composition.
Exemplary sugar alcohols for use in the composition include, but are not
limited to, e.g.,
mannitol, sorbitol, glycol, glycerol, arabitol, erythritol, xylitol, ribitol,
lactitol, and the like
in a concentration range including, but not limited to, e.g., from about 0.1%
to about 10%
by weight sugar alcohol, about 1-5%, about 1-3%, including e.g., 0.1%, 0.5%,
1%, 1.5%,
2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% by weight sugar alcohol based on
the
composition.
The osmolality of the compositions of the invention, including pharmaceutical
compositions, is typically similar to the serum osmolality of blood, which
ranges from
about 250 to about 350 milliosmoles per kilogram (m0Sm/kg) of water. The
concentration of salt in the composition is typically less than 125 mM. The
salt and sugar
concentrations may be adjusted or varied such that the osmolality of the
composition is
from about 250-350 mOSm/kg of water.
Exemplary detergents or emulsifiers for use in the composition include, but
are not
limited to, e.g., polysorbates, such as Tween0-20, Tween0-40, Tween -60,
Tween0-80,
or pluronic F-68 in a range including, but not limited to, e.g., from about
0.001% to about
0.2% by weight of a detergent or emulsifier based on the composition,
including, e.g.,
0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%,
0.02%, 0.03%, 0.04%, 0.05%, 0.075%, and 0.1% by weight of detergent or
emulsifier
(e.g., Tween0-20, Tween0-40, Tween0-60, Tween0-80, or pluronic F-68) based on
the
composition.
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Compositions of the invention, including pharmaceutical compositions, can
comprise a polymer, such as a PEG molecule, in a concentration sufficient to
reduce or
inhibit undesired association between two or more molecules of the invention,
such as,
e.g., two or more mutant CTLA-4-Ig fusion protein dimers of the invention. The
composition can comprise two or more different polymers (e.g., PEGs). The
polymer
(e.g., PEG molecule) typically has a molecular weight of from about 200 Da to
about 8000
Da (e.g., about 200, 300, 400, 600, 900, 1000, 1450, 3350, 4500, or 8000 Da,
available
from Dow Chemical). The addition of a polymer (e.g.. PEG molecule) to the
composition
is believed to reduce the formation of undesired aggregates, particularly
undesired
aggregates of two or more fusion protein dimers of the invention.
Compositions of the invention, including pharmaceutical compositions, can
include a cyclic oligosaccharide, such as a cyclodextrin Captisol
(Cydex)). In one
aspect, the composition comprises two or more different cyclic
oligosaccharides. The
addition of cyclic oligosaccharide(s) to the composition improves the
solubility, stability,
bioavailability, and/or dosing of active pharmaceutical ingredient(s) (e.g..
mutant CTLA-4
molecule).
The pH of a composition of the invention, including a pharmaceutical
composition,
can range from about pH 3 to about pH 10, from about pH 4 to about pH 10, from
about
pH 5 to about pH 9, from about pH 6 to about pH 9, from about pH 5.5 to about
pH 8.5,
from about pH 6.0 to about pH 6.7, from about pH 6.0 to about pH 6.5, from
about pH 6.2
to about pH 8.7, from about pH 6.5 to about pH 8.5. from about pH 6.5 to about
pH 7.5,
from about pH 6.2 to about pH 7.0, from about pH 6.3 to about pH 6.8, from
about pH 6.4
to about pH 6.8, from about pH 7.0 to about pH 8.0, and about pH 7.0 to about
pH 7.4. In
one aspect, compositions comprising a molecule of the invention, such as,
e.g., a mutant
CTLA-4-IgG2, have a pH of pH 5.0, pH 5.1, pH 5.2, pH 5.3, pH 5.4, 5.5, pH 5.6,
pH 5.7,
pH 5.8, pH 5.9, pH 6.0, pH 6.1, pH 6.2, pH 6.3, pH 6.4, pH 6.5, pH 6.6, pH
6.7, pH 6.8,
pH 6.9, pH 7.0, pH 7.1, pH 7.2, pH 7.3, pH 7.4, pH 7.5, pH 7.6, pH 7.7, pH
7.8, pH 7.9,
pH 8.0, pH 8.1, pH 8.2, pH 8.3, pH 8.4, pH 8.5, pH 8.6, pH 8.7, pH 8.8, pH
8.9, pH 9.0,
pH 9.1, pH 9.2, pH 9.3, pH 9.4, pH 9.5, pH 9.6, pH 9.7, pH 9.8, pH, 9.9, or pH
10Ø
In one aspect, the invention provides a composition of the invention
comprising an
excipient or carrier (including, e.g., a pharmaceutical composition comprising
a
pharmaceutically acceptable excipient or carrier) and an effective amount of
any CTLA-4
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polypeptide, multimer, dimer, conjugate, fusion protein, or fusion protein
dimer of the
invention described throughout and herein, and further comprising a buffer
capable of
maintaining the pH of the composition within the range of about pH 3 to about
pH 10,
water, optionally a non-ionic detergent, optionally a salt, and optionally a
sugar alcohol,
monosaccharide, disaccharide, or polysaccharide. Some such compositions are at
a
physiological pH. Some such compositions have a pH of from about 4 to about
7.5, about
5.0 to about 7.5, or from about 6.4 to about 6.6, including, e.g., about pH
6.5, about pH
7.4, or pH 7.5. Some such compositions comprise a buffer in a concentration of
from
about 1 mM to about 100 mM, about 1 mM to about 50 mM, about 5 mM to about 35
mM,
about 10 mM to about 25 mM, including, e.g., about 20 mM, 25mM, or 30 mM. Some
such compositions comprise a buffer selected from the group consisting of a
HEPES
buffer, citrate buffer, succinate buffer, acetate buffer, citrate buffer,
maleate buffer,
phosphate buffer, and Tris buffer. Some such compositions comprise a buffer is
selected
from the group consisting of a HEPES buffer, sodium citrate buffer, and sodium
succinate
buffer. For some such compositions, the pH is from about 6.0 to about 6.7 and
the buffer
is sodium succinate or sodium citrate. For some such compositions, the pH is
about 7.0 to
about 7.7 and the buffer is HEPES. Some such compositions further comprise a
sugar
alcohol or saccharide, wherein the saccharide is a monosaccharide,
disaccharide (e.g.,
sucrose or trehalose), or polysaccharide. Some such compositions comprise a
salt present
in a concentration of about 1 mM to about 50 mM, including, e.g., about 20 mM,
25 mM,
or 30 mM. Some such compositions comprise a non-ionic detergent, such as,
e.g., a non-
ionic detergent selected from the group consisting of from the group
consisting of
Tween -80, Tween -60, Tween10-40, Tween -20, or pluronic F-68.
In some such compositions (including pharmaceutical compositions) described in
the paragraph above, the polypeptide, multimer, dimer, conjugate, fusion
protein, or fusion
protein dimer is present at a concentration in the range of about 1 mg/ml
(weight/volume
or w/v) to about 200 mg/ml (w/v), about 25 mg/ml (w/v) to about 100 mg/ml
(w/v), about
50 mg/ml to about 300 mg/ml, optionally about in a range of about 50 mg/ml
(w/v) to
about 100 mg/ml (w/v). Some such compositions comprise an effective amount of
the
polypeptide, multimer, dimer, conjugate, fusion protein, or fusion protein
dimer of from
about 0.1 mg/kg to about 15 mg/kg, and the composition is administered to a
mammal
(e.g., human). Some such compositions comprise an effective amount of the
polypeptide,
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multimer, dimer, conjugate, fusion protein, or fusion protein dimer of from
about 0.5
mg/kg to about 10 mg/kg, and the composition is administered parenterally.
Some such
compositions comprise an effective amount of the polypeptide, multimer, dimer,
conjugate, fusion protein, or fusion protein dimer of from about 0.1 mg/kg to
about 5
mg/kg, and optionally about 0.5 mg/kg, and the composition is administered
subcutaneously. Some such compositions comprise an effective amount of the
polypeptide, multimer, dimer, conjugate, fusion protein, or fusion protein
dimer of from
about 5 mg/kg to about 15 mg/kg (optionally about 10 mg/kg), and the
composition is
administered intravenously. For some such compositions, the polypeptide,
multimer,
dimer, conjugate, fusion protein, or fusion protein dimer comprises an amino
acid
sequence having at least 95%, at least 96%, at least 97%, at least 98%, or at
least 99%
sequence identity to the amino acid sequence of SEQ ID NO:36. For some such
compositions, the polypeptide, multimer. dimer, conjugate, fusion protein, or
fusion
protein dimer comprises an amino acid sequence having at least 95%, at least
96%, at least
97%, at least 98%, or at least 99% sequence identity to the amino acid
sequence of SEQ
ID NO:50. Some such compositions are sterile and/or are isotonic to blood.
Some such
compositions are liquid compositions. Some such compositions are in a liquid
or a dried
form, wherein the dried form is selected from the group consisting of a
lyophilized form,
an air-dried form, and a spray-dried form.
In an exemplary aspect, the invention provides a pharmaceutical composition
comprising: (i) a CTLA-4-Ig fusion protein of the invention having a
concentration of
from about 1 mg/ml to about 300 mg/ml (e.g., about 1 mg/ml to about 100 mg/ml,
about
50 mg/ml or about 100 mg/ml, etc.) (optionally a dimeric fusion protein); (ii)
a buffer
having a buffering capacity of between about pH 5.0 and about pH 9.0 at a
concentration
of about 5 mM to about 50 rnM; (iii) a pharmaceutically acceptable diluent to
bring the
composition to a designated volume; (iv) a sugar at a concentration of about
0.5% to about
10% by weight sugar based on the composition; (v) a salt at a concentration of
about 1
mM to about 200 mM; (vi) optionally a non-ionic detergent (e.g., Tween -20,
Tween -
40, Tween0-60, Tween0-80, or pluronic F-68) at a concentration of about 0.01
mg/ml to
about 0.5 mg/ml, e.g., about 0.01 mg/ml to about 0.1 mg/m1; and (vii)
optionally a cyclic
oligosaccharide (e.g., cyclodextrin (Captisol ), wherein the pH of the
composition is in a
range of about pH 5.0 to about pH 8Ø Exemplary CTLA-4-Ig fusion protein of
the
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invention include those comprising a polypeptide sequence having at least 91%,
92%,
93%, 94%. 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to at least one
polypeptide sequence selected from the group consisting of SEQ ID NOS:74-79,
197-200,
205-214, and 219-222 (optionally, e.g., selected from the group consisting of
SEQ ID
NOS:197, 199, 211, and 213), wherein the fusion protein binds CD80 and/or CD86
and/or
an extracellular domain thereof and/or suppresses an immune response. Such
fusion
proteins may be in monomeric or dimeric form.
In another aspect, the invention provides a pharmaceutical composition
comprising: (i) a conjugate comprising a CTLA-4-Ig fusion protein of the
invention
(optionally a dimeric fusion protein) and a non-polypeptide moiety covalently
attached to
the fusion protein, said conjugate having a concentration of from about 1
mg/ml to about
300 mg/ml (e.g., about 1 mg/ml to about 100 mg/ml, about 50 mg/ml or about 100
mg/ml,
etc.): (ii) a buffer having a buffering capacity of between about pH 5.0 and
about pH 8.0 at
a concentration of about 5 mM to about 50 mM; (iii) a pharmaceutically
acceptable diluent
to bring the composition to a designated volume; (iv) a sugar at a
concentration of about
0.5% to about 10% by weight sugar based on the composition; (v) a salt at a
concentration
of about 1 mM to about 200 mM; and (vi) optionally a non-ionic detergent
(e.g., Tween -
20, Tween10-40, Tween -60, Tween -80, or pluronic F-68) at a concentration of
about
0.01 mg/ml to about 0.5 mg/ml, e.g., about 0.01 mg/ml to about 0.1 mg/ml,
wherein the
pH of the composition is in a range of about pH 5.0 to about pH 8Ø The
conjugate may
comprise one, two, three, four or more non-polypeptide moieties. Each non-
polypeptide
moiety may comprise a polymer (e.g., PEG or PAO) or a sugar moiety. In some
instances,
non-polypeptide moiety is a polymer molecule, such as a PEG molecule. The
polymer
molecule can have any desired molecular weight dependent on the desired
functional
effect (e.g., increased half life, decreased association between fusion
protein molecules,
etc.). In some instances, e.g., the polymer is a PEG having a molecular weight
of from
about 1 kDa to about 100 kDa Da (e.g., 1, 2, 2.5, 3, 5, 8, 10, 12, 20, 25, 30,
40, 60 kDa,
etc.). The non-polypeptide moiety (e.g., sugar moiety or polymer molecule) is
covalently
attached to an attachment group of an amino acid residue of the fusion protein
using
standard procedures as described above. Exemplary CTLA-4-Ig fusion proteins
include
those comprising a polypeptide sequence having at least 91%, at least 92%, at
least 93%,
at least 94%, least 95%, at least 96%, at least 97%, at least 98%, at least
99%, or 100%
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sequence identity to at least one polypeptide sequence selected from the group
consisting
of SEQ ID NOS:74-79, 197-200, 205-214, and 219-222 (optionally, e.g., selected
from the
group consisting of SEQ ID NOS:197, 199, 211, and 213), wherein the fusion
protein
binds CD80 and/or CD86 and/or an extracellular domain thereof and/or
suppresses an
immune response. Such fusion proteins may be in monomeric or dimeric form.
In another aspect, the invention provides a pharmaceutical composition
comprising: (a) a polypeptide comprising a polypeptide sequence having at
least about
94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to a polypeptide sequence
selected
from the group of SEQ ID NOS:1-73, such as, e.g., SEQ ID NOS:36 and 50,
wherein said
polypeptide is present in a concentration range of about 1 to about 200 mg/ml
(w/v); (b) a
buffer having a buffering capacity of between about pH 5.0 and about pH 8.0 at
a
concentration range of about 5 mM to about 50 mM; (c) a phan-naceutically
acceptable
diluent to bring the composition to a designated volume; (d) a sugar at a
concentration of
0.5% to 10% by weight; (e) a salt at a concentration of about 1 mM to about
200 mM; and
(f) optionally a detergent, wherein the pH is in a range of about pH 5.0 to
about pH 8Ø In
some such pharmaceutical compositions, (a) the polypeptide comprises the
polypeptide
sequence of SEQ ID NO:36 present in a concentration range of from about 50
mg/m1 to
about 100 mg/ml; (b) the buffer is HEPES buffer present at a concentration of
about 20
mM; (c) the pharmaceutically acceptable diluent is water; (d) the sugar is
sucrose or
trehalose at a concentration of 2% by weight; (e) the salt is sodium chloride
at a
concentration of about 100 mM; and (f) optionally a detergent selected from
the group
consisting of Tween -80, Tween -60, Tween0-40, Tween -20, or pluronic F-68 at
a
concentration less than or equal to about 0.1 mg/ml, wherein the pH of the
composition is
about pH 7.4. In another such compositions, (a) the polypeptide comprises the
polypeptide sequence of SEQ ID NO:50 present in a concentration range of from
about 50
mg/ml to about 100 mg/ml; (b) the buffer is sodium citrate buffer present at a
concentration of about 20 mM; (c) the pharmaceutically acceptable diluent is
water; (d)
the sugar is sucrose or trehalose at a concentration of 2% by weight; (e) the
salt is sodium
chloride at a concentration of about 100 mM; and (f) optionally a detergent
selected from
the group consisting of Tween -80, Tween -60, Tween -40, Tween -20, or
pluronic F-
68 at a concentration less than or equal to about 0.1 mg/ml, wherein the pH is
about pH
6.5.
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In another aspect, the invention provides a pharmaceutical composition
comprising: (a) a polypeptide comprising an amino acid sequence having at
least 96%, at
least 97%, at least 98%, or at least 99% sequence identity to the amino acid
sequence of
SEQ ID NO:36; and (b) HEPES or sodium citrate buffer (e.g., disodium citrate-
trisodium
citrate mixture, sodium citrate-citric acid mixture, citric acid-trisodium
citrate mixture,
monosodium citrate-di sodium citrate mixture, or citric acid-monosodium
citrate mixture).
Also provided is a pharmaceutical composition comprising: (a) a polypeptide
comprising an amino acid sequence having at least 97%, at least 98%, or at
least 99%
sequence identity to the amino acid sequence of SEQ ID NO:36; and (b) a
pharmaceutically acceptable excipient or a pharmaceutically acceptable
carrier, wherein
the composition has a pH from about 7 to about 8. Some such pharmaceutical
compositions have a pH of about 7.4 or 7.5. Some such pharmaceutical
compositions
comprise HEPES or sodium citrate buffer.
Also provided is a pharmaceutical composition comprising: (a) a polypeptide
comprising an amino acid sequence having at least 96%, at least 97%, at least
98%, or at
least 99% sequence identity to the amino acid sequence of SEQ ID NO:50; and
(b) sodium
citrate buffer (e.g., disodium citrate-trisodium citrate mixture, sodium
citrate-citric acid
mixture, citric acid-tris odium citrate mixture, monosodium citrate-disodium
citrate
mixture, or citric acid-monosodium citrate mixture).
Also provided is a pharmaceutical composition comprising: (a) a polypeptide
comprising an amino acid sequence having at least 97%, at least 98%, or at
least 99%
sequence identity to the amino acid sequence of SEQ ID NO:50; and (b) a
pharmaceutically acceptable excipient or a pharmaceutically acceptable
carrier, wherein
the composition has a pH from about 6 to about 7. Some such pharmaceutical
compositions have a pH of about 6.5. Some such pharmaceutical compositions
comprise
sodium citrate buffer.
In one exemplary aspect, the invention provides a pharmaceutical composition
comprising from about 1 mg/ml to about 300 mg/ml of a CTLA-4-Ig fusion protein
of the
invention (e.g., D3-54-IgG2) (e.g., about 1 mg/ml to about 100 mg/ml, e.g.,
about 50
mg/rn1 or about 100 mg/ml) which is typically expressed as a dimeric fusion
protein, in 20
mM HEPES buffer in water, 100 mM NaC1, 2% by weight sucrose based on the
composition, pH 7.4, optionally including a non-ionic detergent (e.g., Tween -
20,
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Tween0-40, Tween0-60, Tween0-80. or pluronic F-68) at a concentration of about
0.01
mg/ml to about 0.5 mg/ml, e.g., about 0.01 mg/ml to about 0.1 mg/ml, and
optionally
including a polyethylene glycol (PEG), such as a PEG molecule having a
molecular
weight of from about 200 Daltons (Da) to about 8000 Da (e.g., about 200, 300,
400, 600,
900, 1000, 1450, 3350, 4500, or 8000 Da, available from Dow Chemical). In
another
exemplary aspect, the invention provides a pharmaceutical composition
comprising from
about 1 mg/ml to about 300 mg/ml of a CTLA-4-Ig fusion protein of the
invention (e.g.,
D3-69-IgG2), which is typically expressed as a dimefic fusion protein, in 20
mM sodium
citrate buffer in water, 100 mM NaCl, 2% by weight sucrose based on the
composition,
pH 6.5, optionally including a non-ionic detergent (e.g., Tween0-20, Tween -
40,
Twe,en0-60, Tween0-80, or pluronic F-68) at a concentration of about 0.01
mg/m1 to
about 0.5 mg/ml, e.g., about 0.01 mg/ml to about 0.1 mg/ml, and optionally
including a
PEG molecule, such as a PEG molecule having a molecular weight of from about
200 Da
to about 8000 Da (e.g., about 200, 300, 400, 600, 900, 1000, 1450, 3350, 4500,
or 8000
Da, available from Dow Chemical).
The invention includes receptacles for containing a composition of the
invention
comprising a molecule of the invention (e.g., mutant CTLA-4 molecule, such as
a mutant
CTLA-4-Ig) and an excipient, diluent, or carrier. The composition may be a
pharmaceutical composition comprising a molecule of the invention and a
pharmaceutically acceptable excipient, diluent or carrier. Receptacles
include, but are not
limited to, e.g., vials (e.g., glass vial, such as a Type I glass vial),
autoinjectors, pen
injectors (fixed dose or variable dose), and pre-filled syringes, or other
suitable containers.
If desired, a receptacle can contain one or more pre-determined doses of the
molecule of
the invention effective to suppress an immune response or treat an immune
system disease
or disorder as described elsewhere herein. Some such receptacles are useful
for
administration of the composition contained therein to a subject suffering
from an immune
disease or disorder (e.g.. autoinjectors, pen injectors. pre-filled syringes,
etc.). Some such
receptacles allow for self-administration of the composition by the subject
(e.g., pen
injectors, autoinjectors, pre-filled syringes, etc.).
Also provided are stable compositions or formulations of a molecule (e.g.,
mutant
CTLA-4 ECD or mutant CTLA-4-Ig) of the invention, including pharmaceutically
acceptable compositions of a molecule of the invention with a pharmaceutically
acceptable
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carrier. In another aspect, the invention includes freeze-dried or lyophilized
compositions
or formulations. The term "freeze-dried" or "lyophilized" generally refers to
the state of a
substance which has been subjected to a drying procedure such as freeze-drying
or
lyophilization, where at least 50% of moisture has been removed. Pre-
lyophilization and
lyophilization procedures are well known in the art (see, e.g., LYOPHILIZATION
OF
BIOPHARMACEUTICALS, Vol. 2 of BIOTECHNOLOGY: PHARMACEUTICAL ASPECTS (Henry R.
Costantino et al. eds., 2004), U.S. 6,436,897, WO 06/104852), and would be
readily
understood by a skilled artisan. Any suitable lyophilization procedure can be
employed or
modified as appropriate by one skilled on the art in preparing the lyophilized
composition
of the invention. A freeze-dried, air-dried, spray-dried, or lyophilized
composition is
usually prepared from a liquid, such as a solution, suspension, emulsion, etc.
The liquid to
be freeze-dried, air-dried, spray-dried, or lyophilized typically includes all
of the
components (except the liquid, e.g., water) that are to be in the final
reconstituted liquid
composition. In this way, the freeze-dried, air-dried, spray-dried, or
lyophilized
composition will have the desired liquid composition (e.g., pharmaceutical
composition)
when reconstituted. Exemplary compositions of the invention, including
pharmaceutical
compositions, comprising a molecule of the invention (e.g., mutant CTLA-4-Ig
fusion
protein of the invention, such as, e.g., SEQ ID NO:197, 199, 211, or 213),
which are
described throughout this application, can be freeze-dried, air-dried, spray-
dried, or
lyophilized to produce a stable freeze-dried, air-dried, spray-dried, or
lyophilized
composition, respectively, by using standard procedures known in the art. See
e.g.,
exemplary procedures described in LYOPHILIZATION OF BIOPHARMACEUTICALS, supra.
For example, a container (e.g., vial, such as a glass vial) containing a
liquid
composition a molecule of the invention (e.g., mutant CTLA-4-Ig, fusion
protein of the
invention, such as, e.g., SEQ ID NO:197, 199, 211, or 213) to be lyophilized
can be
lyophilized by using standard procedures known by those of ordinary skill in
the art. See,
e.g., LYOPHILIZATION OF BIOPHARMACEUTICALS. supra. The lyophilized molecule of
the
invention (e.g., mutant CTLA-4-Ig of the invention) can subsequently be
reconstituted
with a liquid to generate a reconstituted liquid composition. Lyophilized
formulations are
typically reconstituted by the addition of an aqueous solution to dissolve the
lyophilized
formulation. Any suitable aqueous liquid or solution can be used to
reconstitute a
lyophilized formulation. A lyophilized formulation is often reconstituted
using sterile or
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distilled water, but solutions comprising carriers, excipients, diluents
buffers, and/or other
components, including those described throughout, can be used for
reconstitution.
In one aspect, the invention provides a pharmaceutical composition in
lyophilized
form, wherein the composition comprises from about 1 mg/ml to about 300 mg/ml
of a
CTLA-4-1g fusion protein of the invention, which is typically expressed as a
dimeric
fusion protein, in appropriate buffer (e.g., HEPES, disodium citrate-trisodium
citrate, etc.)
in water at a concentration to maintain the desired pH (e.g., about pH 6.0 to
about pH 7.5),
salt (e.g., 50 mM NaC1), sugar (e.g., 4-6% by weight sucrose based on the
composition),
and optionally including a non-ionic detergent (Tween0-20, Tween0-40, Tween0-
60,
Tween0-80, or pluronic F-68) at a concentration of about 0.01 mg/ml to about
0.5 mg/ml,
e.g., about 0.01 mg/ml to about 0.1 mg/ml (e.g., Tween0-20, Tween0-60, Tween0-
80, or
pluronic F-68). A lyphophilized form of a pharmaceutical typically includes a
lower salt
concentration and a higher sugar concentration compared to a non-lyophilized
liquid
composition.
.1ri one particular aspect, the Invention provides a stable lyophilized
composition
for therapeutic administration upon reconstitution with sterile water which
comprises a
therapeutically effective amount of a molecule of the invention and optionally
one or more
of the following pharmaceutically acceptable components: (a) a sugar or
saccharide, such
a sucrose, mannose, dextrose, or trehalose in an amount of from about 1% by
weight to
about 10% by weight; (b) a detergent or emulsifier, such as Tween -20, Tween0-
40,
Tween0-60, Tween -80, or pluronic F-68; (c) an isotonic agent or salt, such as
an
inorganic salt (e.g., sodium chloride) in a concentration of from 0 mM to
about 50 mM
(including, e.g., the concentrations set forth above; (d) a suitable buffer to
maintain the pH
of the composition within a range which is conducive to the stability of the
molecule; (e)
dispersing agent (e.g., in an amount sufficient for long-term dispersion of
the molecule of
the invention, such as, e g., from 0.001 w/v% to about 1.0 w/v%) (e.g.,
polysorbate, such
as Tween0-20, Tween0-40, Tween0-60, or Tween0-80, or pluronic F-68); and (0 a
stabilizer (e.g., saccharide, dextrans, low molecular weight (MW) PEG group,
such as
PEG having MW of from about 200 Da to about 8000 Da (e.g., 200, 300, 400, 600,
900,
1000, 1450, 3350, 4500, or 8000 Da) or preservative. In some such stable
lyophilized
compositions, the molecule of the invention is a recombinant or isolated
fusion protein of
the invention, such as a fusion protein comprising a polypeptide sequence
having at least
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95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence
identity to
at least one polypeptide sequence selected from the group consisting of SEQ ID
NOS:74-
79, 197-200, 205-214. and 219-222 (optionally, e.g., selected from the group
consisting of
SEQ ID NOS:197, 199, 211, and 213), wherein the fusion protein binds CD80
and/or
CD86 and/or an extracellular domain thereof and/or suppresses an immune
response.
Such fusion proteins may be in monomeric or dimeric form.
Exemplary amounts of each such component in the lyophilized composition
include those described above and herein. In one aspect, the buffer is
selected so as to
maintain the pH of the composition within a range of from about pH 3 to about
pH 8, from
about pH 4 to about pH 7.5. A lyophilized composition of the invention
comprising a
recombinant mutant CTLA-4-Ig fusion protein of the invention is typically
stable at -80
to +40 C and/or substantially maintains its biological activity for at least
one week, one or
more months (e.g., six months), one year, two years, three years, four years,
or more when
stored at ambient temperatures (e.g., about 22 C to about 30 C). Upon
reconstitution with
a liquid (e.g., sterile water for injection (WFI)), the lyophilized
composition is suitable for
administration (e.g., iv., s.c., parenteral, i.m., i.d., i.p., etc.) to a
subject (e.g., human).
The invention also provides a kit comprising a lyophilized or freeze-dried
composition comprising a lyophilized or freeze-dried molecule of the invention
(e.g.,
mutant CTLA-4-Ig fusion protein, such as, e.g., SEQ ID NO:197, 199, 211, or
213) in a
first container (e.g., vial, such as a glass vial) and instructions for
reconstituting the freeze-
dried or lyophilized composition using a liquid (e.g., sterile water, WFI, or
buffer).
Optionally, the kit further comprises a second container (e.g., vial, such as
a glass vial)
containing a sufficient amount of liquid (e.g., sterile water, WFI or buffer)
for
reconstitution of the lyophilized or freeze-dried composition into a liquid
composition. In
this instance, reconstitution is achieved by using a syringe to remove a
desired volume of
water from the second container and to introduce the water into the first
container. The
first container is then rocked gently to put the molecule of the invention
(e.g., fusion
protein) into solution. The kit may include a device(s) for reconstituting the
lyophilized or
freeze-dried composition and/or administering the reconstituted liquid
composition.
Exemplary devices include, but are not limited to, e.g., a two-component
mixing syringe,
dual-chambered syringe, and dual-chambered autoinjector. One component or
chamber
contains the lyophilized composition and the second component or chamber
contains the
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liquid for reconstitution. With such devices, reconstitution is typically
carried out just
prior to administration, and the reconstituted composition is usually
administered
parenterally (e.g., s.c., iv., i.m., i.d. injection).
The composition or pharmaceutical composition of the invention can comprise or
be in the form of a liposome. Suitable lipids for liposomal formulation
include, without
limitation, monoglycerides, diglycerides, sulfatides, lysolecithin,
phospholipids, saponin,
bile acids, and the like. Preparation of such liposomal formulations is
described in, e.g.,
U.S. Patent Nos. 4,837,028 and 4,737,323.
The form of the compositions or pharmaceutical composition can be dictated, at
least in part, by the route of administration of the polypeptide, conjugate,
nucleic acid,
vector, virus, VLP, or cell of interest. Because numerous routes of
administration are
possible, the form of the pharmaceutical composition and its components can
vary. For
example, in transmucosal or transdermal administration, penetrants appropriate
to the
barrier to be permeated can be included in the composition. Such penetrants
are generally
known in the art, and include, for example, for transmucosal administration,
detergents,
bile salts, and fusidic acid derivatives. In contrast, in transmucosal
administration can be
facilitated through the use of nasal sprays or suppositories.
A common administration form for compositions of the invention, including
pharmaceutical compositions, is by injection. Injectable pharmaceutically
acceptable
compositions typically comprise one or more suitable liquid carriers such as
water,
petroleum, physiological saline, bacteriostatic water, Cremophor ELTM (BASF,
Parsippany, NJ), PBS, or oils. Liquid pharmaceutical compositions can further
include
physiological saline solution, dextrose (or other sacchaiide solution),
alcohols (e.g.,
ethanol), polyols (polyalcohols, such as mannitol, sorbitol, etc.), or
glycols, such as
ethylene glycol, propylene glycol. PEG molecules, coating agents which promote
proper
fluidity, such as lecithin, isotonic agents, such as mannitol or sorbitol,
organic esters such
as ethyoleate, and absorption-delaying agents, such as aluminum monostearate
and
gelatins. The injectable composition can be in the form of a pyrogen-free,
stable, aqueous
solution. An injectable aqueous solution may comprise an isotonic vehicle such
as sodium
chloride, Ringer's injection solution, dextrose, lactated Ringer's injection
solution, or an
equivalent delivery vehicle (e.g., sodium chloride/dextrose injection
solution).
Formulations suitable for injection by intraarticular, intravenous,
intramuscular,
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intradermal, subderrnal, intraperitoneal, and subcutaneous routes, include
aqueous and
non-aqueous, isotonic sterile injection solutions, which can include solvents,
co-solvents,
antioxidants, reducing_ agents, chelating agents, buffers, bacteriostats,
antimicrobial
preservatives, and solutes that render the formulation isotonic with the blood
of the
intended recipient (e.g., PBS and/or saline solutions, such as 0.1 M NaCl),
and aqueous
and non-aqueous sterile suspensions that can include suspending agents,
solubilizers,
thickening agents, emulsifying agents, stabilizers, and preservatives.
The administration of a polypeptide, conjugate, nucleic acid, vector, virus,
pseudovirus, VLP or cell of the invention (or a composition comprising any
such
component) can be facilitated by a delivery device formed of any suitable
material.
Examples of suitable matrix materials for producing non-biodegradable
administration
devices include hydroxapatite, bioglass, aluminates, or other ceramics. In
some
applications, a sequestering agent, such as carboxymethylcellulose (CMC),
methylcellulose, or hydroxypropylmethylcellulose (HPMC), can be used to bind
the
particular component to the device for localized delivery.
A nucleic acid or vector of the invention can be formulated with one or more
poloxamers, polyoxyethylene/polyoxypropylene block copolymers, or other
surfactants or
soap-like lipophilic substances for delivery of the nucleic acid or vector to
a population of
cells or tissue or skin of a subject. See e.g., U.S. Pat. Nos. 6,149,922,
6,086,899, and
5,990,241.
Nucleic acids and vectors of the invention can be associated with one or more
transfection-enhancing agents. In some embodiments, a nucleic acid and/or
nucleic acid
vector of the invention typically is associated with one or more stability-
promoting salts,
carriers (e.g., PEG), and/or formulations that aid in transfection (e.g.,
sodium phosphate
salts, dextran carriers, iron oxide carriers, or biolistic delivery ("gene
gun") carriers, such
as gold bead or powder carriers). See, e.g., U.S. Patent No. 4,945,050.
Additional
transfection-enhancing agents include viral particles to which the nucleic
acid or nucleic
acid vector can be conjugated, a calcium phosphate precipitating agent, a
protease, a
lipase, a bipuvicaine solution, a saponin, a lipid (e.g., a charged lipid), a
liposome (e.g., a
cationic liposome), a transfection facilitating peptide or protein-complex
(e.g., a
poly(ethylenimine), polylysine, or viral protein-nucleic acid complex), a
virosome, or a
modified cell or cell-like structure (e.g., a fusion cell).
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Nucleic acids and vectors of the invention can also be delivered by in vivo or
ex
vivo electroporation methods, including, e.g., those described in U.S. Patent
Nos.
6,110,161 and 6,261,281, and Widera et al., J. of Immunol. 164:4635-4640
(2000).
Transdermal administration of a component of the invention (e.g., polypeptide,
conjugate, nucleic acid, vector, virus, VLP, and/or cell of the invention) can
be facilitated
by a transdermal patch comprising such component in any suitable composition
in any
suitable form. Such transdermal patch devices are provided by the invention.
For
example, such component can be contained in a liquid reservoir in a drug
reservoir patch
device, or, alternatively, the component can be dispersed throughout a
material suitable for
incorporation in a simple monolithic transdermal patch device. Typically, the
patch
comprises an immunosuppressive amount of at least one such component ¨ such as
an
amount effective to suppress an immune response in a subject contacted with
the patch.
Examples of such patch devices are known in the art. The patch device can be
either a
passive device or a device capable of iontophoretic delivery of at least one
such
component to the skin or tissue of the subject.
A composition, particularly a pharmaceutical composition, may comprise any
suitable dose of at least one such component of the invention (e.g.,
polypeptide, conjugate,
nucleic acid, vector, virus, VLP, and/or cell) sufficient to achieve the
desired
immunosuppressive response in a subject following administration. Proper
dosage can be
determined by any suitable technique and considerations for determining the
proper are
known in the art. In a simple dosage testing regimen, low doses of the
composition are
administered to a test subject or system (e.g., an animal model, cell-free
system, or whole-
cell assay system). Dosage is commonly determined by the efficacy of the
particular
component to be administered, the condition of the subject, the body weight of
the subject,
and/or target area of the subject to be treated. The size of the dose is also
determined by
the existence, nature, and extent of any adverse side-effects that accompany
the
administration of any such particular component in a particular subject.
Principles related
to dosage of therapeutic and prophylactic agents are provided in, e.g., Platt,
Clin. Lab
Med. 7:289-99 (1987), "Drug Dosage," J. Kans. Med. Soc. 70(1):30-32 (1969),
and other
references described herein (e.g., Remington's, supra).
By way of example, a therapeutically effective amount of a polypeptide of the
invention for an initial dosage for treating an autoimmune disease may
comprise from
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about 0.001 mg/kg body weight of the subject to about 100 mg/kg body weight of
the
subject, such as, e.g., from about 0.001 milligrams per kilogram (mg/kg) body
weight of
the subject to about 100 milligrams per kilogram (mg/kg) weight of the
subject, or, e.g.,
from about 0.001 mg/kg weight of the subject to at least about 0.005, 0.01,
0.025, 0.05,
0.1, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6. 7, 8, 9,
10, 20, 25, 30, 40, 50,
60, 70, 75, 80, 90, or 100 mg/kg body weight of the subject. Such dosage can
be by any
suitable protocol, e.g., such as administered daily, weekly, or biweekly, or
any
combination thereof (e.g., at about 0, 1, 2, 4, 5, 6, and 7 days, weekly
thereafter, or at
about 0, 1, 2, 4, and 6 weeks), followed by 1-, 2-, 3-month intervals, and by
any suitable
delivery method, such as, e.g., by electroporation or a subcutaneous (s.c.),
intramuscular
(i.m.), intravenous (i.v.), or intraperitoneal (i.p.), subden-nal,
transdennal, parenteral, or
intradennal (i.d.) injection. In some instances, a polypeptide of the
invention is typically
administered as a soluble polypeptide, such as, e.g., a fusion protein
comprising a mutant
CTLA-4 ECD polypeptide of the invention covalently linked to an Ig Fc
polypeptide. For
example, a pharmaceutical composition comprising a mutant CTLA-4-Ig fusion
protein of
the invention in a pharmaceutically acceptable carrier, diluent, or excipient
may be
administered by any appropriate route (e.g., intradermally, intravenously, or
subcutaneously) in an effective amount depending upon the autoimmune disease
(e.g.,
rheumatoid arthritis) or condition to be treated (e.g., to inhibit rejection
of a tissue, cell,
graft, or solid organ transplant from a donor by the recipient subject).
In one exemplary aspect, the invention provides a method of suppressing an
immune response in a subject in need thereof, comprising administering to the
subject a
pharmaceutical composition comprising, e.g., from about 1 mg/ml to about 300
mg/ml,
including from about 25 mg/ml to about 150 mg/ml (e.g., 50 or 100 mg/ml) of D3-
54-
IgG2 fusion protein in 20 mM HEPES buffer in water, 100 mM NaC1, 2% by weight
sucrose, pH 7.4, wherein the subject suffers from an autoirnmune disorder
(e.g.,
rheumatoid arthritis). In another exemplary aspect, the invention provides
method of
inhibiting rejection of a tissue, cell, graft or solid organ transplant from a
donor in a
recipient subject, comprising administering to the recipient subject a
pharmaceutical
composition comprising from about 25 mg/ml to about 100 ing/m1 (e.g., 50 or
100 mg/ml)
of D3-69-IgG2 fusion protein in 20 inM sodium citrate buffer in water, 100 mM
NaC1, 2%
by weight sucrose, pH 6.5.
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Also provided is a viral vector composition, which comprises a carrier or
excipient
and a viral vector of the invention. Pharmaceutical compositions comprising a
pharmaceutically acceptable carrier or excipient and a viral vector are also
provided. The
amount or dosage of viral vector particles or viral vector particle-encoding
nucleic acid
depends on: (1) the type of viral vector particle with respect to origin of
vector, including,
but not limited to, e.g., whether the vector is an alphaviral vector, Semliki-
Forest viral
vector, adenoviral vector, adeno-associated (AAV) viral vector, flaviviral
vector,
papillomaviral vector, and/or herpes simplex viral (HSV) vector, (2) whether
the vector is
a transgene expressing or recombinant peptide displaying vector, (3) the host,
and (4)
other considerations discussed above. Generally, with respect to gene transfer
vectors, the
pharmaceutically acceptable composition comprises at least about 1 x 102 viral
vector
particles in a volume of about 1 ml (e.g., at least about 1 x 102 to 1 x 108
particles in about
1 m1). Higher dosages also can be suitable (e.g., at least about 1 x 106,
about 1 x 108,
about 1 x 109, about 1 x 1010 particles/10.
The invention also provides a composition (including a pharmaceutical
composition) comprising an aggregate of two or more polypeptides or conjugates
of the
invention. Moreover, the invention provides a composition (including a
pharmaceutical
composition) comprising a population of one or more multimeric polypeptides or
multimeric conjugates of the invention. As noted above, pharmaceutical
compositions
include a pharmaceutically acceptable excipient, diluent, or canier.
KITS
The present invention also provides kits including one, two, three, or more of
the
polypeptides (e.g., mutant CTLA-4 ECD polypeptides, mutant CTLA-4-Ig fusion
proteins,
including dimeric fusion proteins), conjugates, nucleic acids, vectors, cells,
and/or
compositions of the invention. Kits of the invention optionally comprise: (1)
at least one
polypeptide (e.g., mutant CTLA-4-Ig fusion protein), conjugate, nucleic acid,
vector, VLP,
cell, and/or composition of the invention; (2) optionally at least one second
immunosuppressive agent (e.g., nonsteroidal anti-inflammatory agent,
methotrexate,
steroid, TNFa antagonist, etc.); (3) instructions for practicing any method
described
herein, including a therapeutic or prophylactic method and instructions for
using any
component identified in (1) or (2); (4) a container for holding the at least
one such
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component identified in (1) or (2); and/or (5) packaging materials. One or
more of the
polypeptides (e.g., mutant CTLA-4-Ig fusion protein), conjugates, nucleic
acids, vectors,
VLPs, cells, and/or compositions of the invention, optionally with one or more
second
immunosuppressive agents, can be packaged in packs, dispenser devices, and
kits for
administration to a subject, such as a mammal, including a human. An effective
amount
of each such polypeptide(e.g., mutant CTLA-4-Ig fusion protein), conjugate,
nucleic acid,
vector, VLP, cell, and/or composition of the invention or optional second
immunosuppressive agent (e.g., dose) for the indicated therapeutic or
prophylactic method
is indicated and one or more such doses is provided. The one or more
polypeptides (e.g.,
mutant CTLA-4-Ig fusion protein), conjugates, nucleic acids, vectors, and/or
cells
compositions, and, if desired, the optional second immunosuppressive agent,
may be
provided in powder (e.g., lyophilized) or liquid form, and may be formulated
with an
excipient or carrier (including, e.g., a pharmaceutically acceptable excipient
or carrier),
thereby forming a composition (including, e.g., pharmaceutical composition).
Packs or
dispenser devices that comprise one or more unit dosage forms are provided.
Typically,
instructions for administration of such components are provided with the
packaging, along
with a suitable indication on the label that the compound is suitable for
treatment of an
indicated condition.
EXAMPLES
The following examples further illustrate the invention, but should not be
construed as limiting its scope in any way.
EXAMPLE 1
This example provides a description of the methods for creating a LEA29Y-Ig
fusion protein, which was used as a control and for comparative purposes in
BiacoreTm
binding and cell-based activity assays.
Creation of DNA Plasmid Vector Encoding LEA29Y-Ig Fusion Protein.
This example describes the making of a DNA plasmid vector that encodes the
LEA29Y-Ig fusion protein. LEA29Y-Ig comprises a specific known mutant CTLA-4
ECD polypeptide, termed "LEA29Y" (or "LEA" or "L104EA29Y" or "A29YL104E"),
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which is covalently linked at its C-terminus to the N-terminus of a specific
mutant human
IgG1 Fc polypeptide. The LEA29Y polypeptide is a mutant CTLA-4 ECD polypeptide
comprising a polypeptide sequence that differs from the polypeptide sequence
of the
human CTLA-4 extracellular domain by two mutations ¨ an A29Y substitution and
a
L104E substitution ¨ where positions 29 and 104 are numbered by reference to
the
polypeptide sequence of the human CTLA-4 ECD polypeptide, with the first amino
acid
residue of human CTLA-4 designated as amino acid residue position 1. See U.S.
7,094,874. The plasmid vector pCDNA3.1-LEA, which includes a nucleotide
sequence
that encodes LEA29Y-Ig, was created to produce this fusion protein.
DNA encoding LEA29Y-Ig is created by PCR assembly using overlapping
oligonucleotides designed based on sequence homology to the nucleotide
sequence
encoding LEA29Y-Ig shown in SEQ ID NO:167. The oligonucleotides are designed,
made, and assembled using standard procedures well known by those of ordinary
skill in
the art and can include stop and start codons and restriction sites as
necessary. The PCR
amplification procedures employed are also well known in the art. See, e.g.,
Berger,
Ausubel, and Sambrook, all supra.
The oligonucleotides are assembled in a 100 p1 PCR reaction with 11.2.M
oligonucleotides, lx Taq buffer (Qiagen; #201225) and 200 RM dNTPs for 30
amplification cycles (94 C, 30 s; 60 C, 30 s; 72 C, 60 s). Amplified DNA is
purified by
QiaQuick PCR Spin Columns (Qiagen, Cat. #28104) and digested with restriction
enzymes Nhel and Sad!. The fragments were separated by agarose-gel
electrophoresis,
purified using Qiaquick Gel Extraction Kit (Qiagen, #28704) as per
manufacturer's
recommendation, and ligated into similarly digested plasmid pCDNA 3.1(+)
(Invitrogen,
Cat. #V790-20). Ligations are transformed into TOP10 E. coli cells (Qiagen,
Cat.
#C4040-10) as per manufacturer's recommendations. The resulting cells are
incubated
overnight at 37 C in LB medium containing 50 pg/ml carbenicillin with shaking
at 250
rpm and then used to make a maxiprep (Qiagen; #12362) stock of plasmid DNA
(referred
to hereinafter as plasmid vector pCDNA3.1-LEA).
The plasmid vector pCDNA3.1-LEA is identical to the plasmid vector pCDNA
mutant CTLA-4-IgG2 vector shown in Figure 1 except that the nucleic acid
sequence
encoding the mutant CTLA-4-IgG2 polypeptide has been replaced by a nucleic
acid
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sequence encoding the LEA29Y-Ig fusion protein. A nucleic acid encoding the
human
CTLA-4 signal peptide was included as the signal peptide-encoding nucleotide
sequence.
A nucleic acid sequence encoding the predicted LEA29Y-Ig fusion protein is
shown in SEQ ID NO:167. SEQ ID NO:167 includes the nucleotide sequence
encoding
the signal peptide (e.g., amino acid residues 1-37 of SEQ ID NO:165). The
polypeptide
sequences of the predicted LEA29Y-Ig and mature LEA29Y-Ig fusion protein
(without the
signal peptide) are shown in SEQ ID NOS:165 and 166, respectively. As
indicated in
Figure 2C, the predicted amino acid sequence of LEA29Y-Ig includes the
following
segments: the predicted signal peptide (amino acid residues 1-37), the LEA29Y
ECD
polypeptide (amino acid residues 38-161), linker (amino acid residue 162), and
a mutant
(modified) Fc domain of a human IgG1 polypeptide (amino acid residues 163-
394). The
amino acid residues at the junctions between these various segments are also
shown in
Figure 2C. Specifically, the last four amino acid residues of the signal
peptide, the first
five and last five amino acid residues of the LEA29Y ECD, the single linker
amino acid
residue (Q), and the first five and last five amino acid residues of the
mutant IgG1 Fc
polypeptide are shown.
The signal peptide is typically cleaved during processing and thus the
secreted
fusion protein (i.e., mature fusion protein) of LEA29Y-Ig does not usually
contain the
signal peptide sequence. The mature/secreted form of LEA29Y-Ig, which has a
total of
357 amino acids, comprises amino acid residues 38-394 (the full-length
sequence without
the signal peptide) of the predicted sequence shown in SEQ ID NO:165, and
begins with
the amino acid sequence: methionine-histidine-valine-alanine. SEQ ID NO:165
includes
the signal peptide (e.g., residues 1-37) at its N-terminus; the signal peptide
is typically
cleaved to form the mature protein shown in SEQ ID NO:166. If desired, the
amino acids
of the mature form can be numbered beginning with the Met of the Met-His-Val-
Ala
sequence, designating Met as the first residue (e.g., the ECD comprises amino
acid
residues numbered 1-124), as in the mature LEA29Y-Ig fusion protein having the
sequence shown in SEQ ID NO:166. In one aspect, the sequence of SEQ ID NO:165
or
166 does not include the C-terminal lysine residue; this residue may cleaved
during
processing or prior to secretion.
The protein sequence of the LEA29Y-Ig fusion protein is described in U.S.
7,094,874. Specifically, SEQ ID NO:4 of U.S. 7,094,874 shows a protein
sequence
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encoding the non-mature form of monomeric LEA29Y-Ig. In U.S. 7,094,874, the
LEA29Y-Ig fusion protein is termed "1-104EA29YIg." The mature LEA29Y-Ig fusion
protein comprising the sequence shown in SEQ ID NO:166 set forth herein
differs from
the fusion protein sequence shown in SEQ ID NO:4 in U.S. 7,094,874 because SEQ
ID
NO:4 of U.S. 7,094,874 includes a signal peptide (i.e., residues 1-26 of SEQ
ID NO:4).
This signal peptide is typically cleaved during processing and thus the mature
(secreted)
form of the LEA29Y-Ig fusion protein does not usually include the signal
peptide
sequence. SEQ ID NO:3 of U.S. 7,094,874 presents a nucleic acid sequence that
encodes
the L104EA29YIg fusion protein (i.e., LEA29Y-Ig).
LEA29Y-Ig typically exists in solution as a dimeric fusion protein comprising
two
identical monomeric fusion proteins. In this instance, each monomeric mature
LEA29Y-
Ig fusion protein comprises a LEA29Y ECD (SEQ ID NO:168) polypeptide fused at
its C-
terminus to the N-terminus of a mutant IgG1 Fc (SEQ ID NO:186). The two LEA29Y-
Ig
monomers are covalently linked together by disulfide bonds formed between
cysteine
residues in each monomer, thereby forming the LEA29Y-Ig fusion protein dimer.
The
LEA29Y-Ig dimer is the form of the fusion protein molecule used in the assays
described
in these Examples, unless explicitly stated otherwise.
Creation of Stable CHO-Kl Cell Line Expressing LEA29Y-Ig Fusion Protein.
A stable cell line was created to generate multi-milligram quantities of the
LEA29Y-Ig fusion protein discussed above.
Transfection of CHO-Kl Cells.
CHO-Kl cells were seeded at a density of 1 x 106 in T-175 flasks (BD Falcon,
#353112) containing 40 ml Growth Medium (DMEM/F12 medium (hivitrogen, #10565-
018) supplemented with 10% fetal bovine serum (FBS) (Hyclone, #SV30014.03) and
lx
PS (Penicillin + Streptomycin)(Invitrogen, #15140-122)). Cells were incubated
for 24
hours (hrs) at 37 C and then transfected with 10 i..(g Maxiprep plasmid DNA
(e.g., plasmid
vector encoding LEA29Y-Ig as described above) mixed with 60 I Fugene 6
(Roche,
#11814443001) as per the manufacturer's recommended conditions. Cells were
incubated
for 2 days (d) at 37 C in Growth Medium and then for 10 d in Selection Medium
(Growth
Medium containing 300 lag/m1 Geneticin (Invitrogen, #10131-027), changing the
media
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every 2 d. The medium was removed and cells were dispersed by addition of 3 ml
0.05%
trypsin (Invitrogen, Cat. #25300-054) and incubation at 37 C for 3 min.
Dispersed cells
were diluted into 10 ml Growth Medium and harvested by centrifugation at 1000
rpm for 5
mm at room temperature (RT) in a GH-3.8 rotor (Beckman Coulter, #360581).
After
discarding the supernatant, cells were suspended in 1 ml growth medium,
filtered through
40 pm membranes (BD Falcon, #352340), and adjusted to a density of I x 106
cells/ml.
Separation of Unique Clones.
Using a cell-sorter (Dako, MoFlo), live cells were individually dispersed into
96-
well culture plates (Sigma-Aldrich. #CLS-3596) containing 200 vl/well Growth
Medium
containing 25% Conditioned Medium (Growth Medium previously harvested from
untransfected (or naïve) cell cultures). After incubation at 37 C for 10-14 d,
cells were
dispersed by trypsin hydrolysis and transferred to new culture plates
containing 200
1.11/well Growth Medium. Cells were cultured at 37 C in Growth Medium until
cell
density reached 70% confluence (approximately 14 d, with medium changed every
7 d).
Identification of Desired Clones.
Clones expressing high levels of recombinant LEA29Y-Ig fusion protein were
identified by dot-blot and western analysis. For dot-blot analysis, 100 Ill of
medium was
harvested from each well of the 96-well culture plates and transferred to
nitrocellulose
membranes (Whatman, #10439388) as per the manufacturer's recommendations.
Membranes were washed twice with 200 ml PBST (PBST is phosphate-buffered
saline
(PBS) + 0.05% Tween -20) for 10 min at room temperature (RT) and then
incubated with
PBST containing 5% nonfat dry milk (EMD, #1.15363.0500) for 1 hour (hr) at RT.
Membranes were washed as described above and incubated for 1 hr at RT in 20 ml
PBST
containing horseradish peroxidase (HRP)-conjugated goat anti-human Ig antibody
(Vector
Labs, #BA-3000) diluted to 1:4000. Membranes were washed as described above
and
incubated for 1 hr at RT with PBST containing streptavidin-HRP reagent (BD
Biosciences, #554066) diluted 1:2000. Membranes were washed as described above
and
signals were detected using ECL Western Blot Detection Reagent (Amersham, Cat.
#RPN2132) as per the manufacturer's recommended conditions. Positive clones
identified
by high signal intensity (i.e., expressing high levels of fusion protein) were
dispersed by
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trypsin hydrolysis and transferred to 6-well culture plates (BD Falcon, Cat.
#353046)
containing 2 ml/well Growth Medium. After incubation at 37 C for 3-4 d, cells
were
dispersed by trypsin hydrolysis and transferred to T-75 flasks (BD Falcon,
Cat. #353136)
containing 20 ml Growth Medium. After incubation at 37 C for 2 d, 100 tl of
medium
was harvested and analyzed for protein expression levels by western analysis.
For western
analysis, equal amounts (15 ill) of medium from each cell culture was run
through 4-12%
Bis-Tris NuPAGE gels (Invitrogen, #NP0322BOX) in MES (MES is 2-(N-
morpholino)ethanesulfonic acid, pH 7.3) running buffer (Invitrogen, #NP0002)
as per the
manufacturer's recommended conditions. Proteins were transferred from gels to
nitrocellulose membranes (Invitrogen, Cat. #LC2001) by electro-transfer as per
the
manufacturer's recommended conditions. Membranes were processed as described
above
for dot-blotting and positive clones (expressing the fusion protein of
interest) were
identified by signal intensity and apparent molecular weight. Positive clones
were
dispersed by trypsin hydrolysis as described above and propagated in T-175
flasks
containing 40 ml Growth Medium.
Production and Purification of LEA29Y-Ig Fusion Protein.
Propagation of Roller Bottle Cultures.
A Stable CHO-K 1 cell line that had been transfected as described above with
nucleic acid encoding the fusion protein of interest was grown to confluence
in T-175
flasks containing 40 ml Growth Medium (DMEM/F-12 medium (Invitrogen, #10565-
018)
supplemented with 10% FBS (Hyclone #SV30014.03) and lx PS (Invitrogen, #15140-
122)). Cells were harvested by incubation in 3 ml 0.05% trypsin (Invitrogen,
Cat. #25300-
054) for 3 min at 37 C, diluted into 12 ml Growth Medium and then transferred
to roller
bottles (Corning, Cat. #431191) containing 250 ml Growth Medium. After
incubation of
roller bottle cultures at 37 C in a humidified rolling incubator for 2 d, the
media was
removed and replaced with 250 ml fresh Growth Medium. Cultures were incubated
for 2
d at 37 C and the medium was replaced with 250 ml UltraCHO Medium (UltraCHO
medium (BioWhittaker, Cat. #12-724) supplemented with 1/1000 EX-CYTE
(Serologicals
Proteins, Cat. #81129N) and lx PS). After incubation for 2 d at 37 C, the
media was
replaced with 250 ml fresh UltraCHO Medium. Cultures were incubated for 2 d at
37 C
and the medium was replaced with 250 ml Production Medium (DMEM/F-12 medium
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supplemented with 1/100x 1TSA (Life Technologies #51300-044), 1/1000x EX-CYTE
and
lx PS). During production, media was harvested and replaced with fresh
Production
Media every other day.
Protein Purification.
Production media from roller bottle cultures was clarified by centrifugation
at 2500
x g for 30 min at RT followed by filtration through 0.2 1.tM membranes (VWR.
Cat.
#73520-986). Media were concentrated 10-fold by tangential flow filtration
using 10 kDa
MWCO membranes (Millipore, Cat. #P3C010000) and then used for Protein-A
affinity
chromatography using a BioCad vision HPLC system. Ig-fusion protein was bound
to
Poros 20 Protein-A resin (Applied Biosystems, Cat. #1-5029-01) in PBS buffer,
washed
with the same buffer, eluted with 80 mM citric acid buffer (pH 4.0) containing
160 mM
sodium chloride and then neutralized by addition of 2M Tris base. The protein
solution
was finally dialyzed against 6 liters (I) PBS using 10 kDa MWCO membranes
(Pierce,
Cat. #PI66810).
EXAMPLE 2
This example describes exemplary methods used to create and screen libraries
of
CTLA-4 mutants for altered human CD80 and/or human CD86 binding activities by
phage
display.
Human CD80-Ig Fusion Protein.
Human CD80-Ig ("hCD80-Ig") and human CD86-Ig ("hCD86-Ig") fusion proteins
were used as ligands in phage panning and phage ELISA experiments to identify
mutant
CTLA-4 molecules that bind human CD80 ("hCD80") and/or human CD86 ("hCD86")
and/or an extracellular domain of either or both. Human CD80-Ig (also termed
"hB7.1-Ig"
or "hB7-1-Ig") and human CD86-Ig (also termed "hB2.1-Ig" or "hB2-1-Ig") fusion
proteins are available from R&D Systems (Minneapolis, MN).
A representative nucleic acid sequence encoding the predicted WT human CD80-
IgG1 fusion protein, which comprises the human CD80 signal peptide, human CD80
ECD,
and human IgG1 Fc, is shown in SEQ ID NO:172. The predicted and mature
polypeptide
sequences of the hCD80-IgG1 fusion protein are shown in SEQ ID NO:170 and SEQ
ID
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NO:171, respectively. The predicted fusion protein shown in SEQ ID NO:170
comprises
WT human CD80 ECD covalently fused at its C-terminus to the N-terminus of a
human
IgG1 Fc polypeptide and includes a signal peptide at its N-terminus. The
signal peptide is
typically cleaved to form the mature CD80-Ig fusion protein shown in SEQ ID
NO:171.
Human CD80-IgG1 is typically abbreviated herein as hCD80-Ig. As shown in
Figure 2A, the predicted amino acid sequence of the hCD80-Ig fusion protein
(also
designated "CD80-IgGl") includes the following segments: the predicted signal
peptide
(amino acid residues 1-34), human CD80 ECD (amino acid residues 35-242),
linker
(amino acid residues 243-245), and human IgG1 Fc polypeptide (amino acid
residues 246-
476). The amino acid residues at the junctions between these various segments
are shown
in Figure 2A. Specifically, the last four amino acid residues of the signal
peptide, the first
five and last five amino acid residues of the human CD80 ECD, the amino acid
residues of
the linker (GVT), and the first five and last five amino acid residues of the
human IgG1 Fc
polypeptide are shown. In the CD80-Ig fusion protein, three residues GVT are
present as
a cloning artifact (or linker) between the C-terminus of the CD80 ECD (which
ends with
the amino acid residues FPDN) and the N-terminus of the IgG1 Fc polypeptide
(which
begins with the amino acid residues PKSC). This GVT cloning artifact or linker
is shown
in the predicted and mature CD80-Ig polypeptide sequences shown in SEQ ID
NO:170
and 171, respectively.
The signal peptide is typically cleaved during processing and thus the
secreted
fusion protein (i.e., mature fusion protein) of hCD80-Ig does not usually
contain the signal
peptide. The mature/secreted form of hCD80-Ig, which has a total of 442 amino
acids,
comprises amino acid residues 35-476 (the full-length sequence without the
signal
peptide) of SEQ ID NO:170, and begins with the amino acid residue sequence:
valine-
isoleucine-histidine-valine. If desired, the amino acids of the mature form
can be
numbered beginning with the valine (Val) of the Val-Ile-His-Val sequence,
designating
Val as the first residue (e.g., the ECD comprises amino acid residues numbered
1-208), as
in the mature form of hCD80-Ig comprising the polypeptide sequence shown in
SEQ ID
NO:171.
The hCD80-Ig fusion protein typically exists in solution as a dimeric fusion
protein
comprising two identical monomeric mature hCD80-Ig fusion proteins. In this
instance,
each monomeric mature hCD80-Ig fusion protein (SEQ ID NO:171) comprises a
human
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CD80 ECD (SEQ ID NO:174) fused at its C-terminus to the N-terminus of a human
IgG1
Fc (SEQ ID NO:185). The two hCD80-Ig monomers are covalently linked together
by
disulfide bonds formed between cysteine residues in each monomer, thereby
forming the
hCD80-Iil fusion protein dimer. The hCD80-Ig fusion protein dimer is the form
of the
fusion protein molecule used in the assays described in these Examples, unless
explicitly
stated otherwise.
A representative nucleic acid encoding the predicted full-length human CD80
polypeptide is shown in SEQ ID NO:196. The nucleic acid sequence shown in SEQ
ID
NO:196 encodes the human CD80 signal peptide, ECD, transmembrane domain, and
cytoplasmic domain, and includes the TAA stop codon at the C-terminus.
Human CD86-Ig Fusion Protein.
A representative nucleic acid sequence encoding the predicted amino acid
sequence of human CD86-human IgG1 (typically abbreviated herein as "hCD86-Ig")
fusion protein is shown in SEQ ID NO:179. This nucleic acid sequence includes
a
nucleotide sequence encoding a signal peptide the mature human CD86-human IgG1
fusion protein. The predicted amino acid sequence of hCD86-Ig fusion protein
is shown
in SEQ ID NO:177, and an exemplary nucleic acid encoding the predicted hCD86-
Ig
fusion protein is shown in SEQ ID NO:179.
As shown in Figure 2B, the predicted amino acid sequence of the hCD86-Ig
fusion
protein includes the following segments: the predicted signal peptide (amino
acid residues
1-23), human CD86 extracellular domain (amino acid residues 24-243), linker
sequence
(amino acid residues 244-246), and human IgG1 Fc polypeptide (amino acid
residues 247-
477). The amino acid residues at the junctions between these various segments
are also
shown in Figure 2B. Specifically, the last four amino acid residues of the
signal peptide,
the first five and last seven amino acid residues of the human CD86 ECD, the
amino acid
residues of the linker (GVT), and the first five and last five amino acid
residues of the
human IgG1 Fc polypeptide are shown.
The CD86 signal peptide is typically cleaved from the predicted hCD86-Ig
polypeptide during processing and thus the secreted human CD86-Ig fusion
protein (i.e.,
mature fusion protein) does not usually include the signal peptide. The
mature/secreted
form of hCD86-Ig, which has a total of 454 amino acids, comprises amino acid
residues
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24-477 (the fill-length sequence without the signal peptide) of SEQ ID NO:177,
and
begins with the following amino acid residue sequence: alanine-proline-
leucine. If
desired, the amino acids of the mature fusion protein can be numbered
beginning with the
alanine residue (Ala) of the Ala-Pro-Leu sequence, designating Ala as the
first residue
(e.g., the ECD comprises amino acid residues numbered 1-218), as in the mature
form of
hCD86-Ig comprising the polypeptide sequence shown in SEQ ID NO:178. The
mature
fusion protein (SEQ ID NO:178) comprises a WT hCD86 ECD protein covalently
fused at
its C-terminus to the N-terminus of a hIgG1 Fc polypeptide.
The hCD86-Ig fusion protein typically exists in solution as a dimeric fusion
protein
comprising two identical monomeric mature hCD86-Ig fusion proteins. In this
instance,
each monomeric mature CD86-Ig fusion protein (SEQ ID NO:178) comprises a human
CD86 ECD (SEQ ID NO:180) fused at its C-terminus to the N-terminus of a human
IgG1
Fc (SEQ ID NO:185). The two hCD86-Ig monomers are covalently linked together
by
disulfide bonds formed between cysteine residues in each monomer, thereby
forming the
hCD86-Ig fusion protein dimer. The hCD86-Ig fusion protein dimer is the form
of the
fusion protein molecule used in the assays described in these Examples, unless
explicitly
stated otherwise.
In the CD86-Ig fusion protein (e.g., predicted and mature forms), three
residues
GVT are present as a cloning artifact (or linker) between the C-terminus of
the CD86 ECD
and the N-terminus of the IgG1 Fc polypeptide. In another aspect, the WT human
CD86
ECD protein comprises a polypeptide sequence comprising amino acid residues 1-
218 of
SEQ ID NO:180 (i.e., excluding the last two C-terminal amino acid residues at
the (PP)).
Orencia Fusion Protein.
As an additional control and for comparative purposes, a commercially
available
fusion protein known as the Orencia fusion protein (Bristol-Myers Squibb Co.,
Princeton, NJ) was purchased. The Orencia fusion protein is composed of the
WT
human CTLA-4 extracellular domain covalently fused at its C-terminus to the N-
terminus
of a specific mutant IgG1 Fc polypeptide. The Orencia protein is a dimeric
fusion
protein comprising two identical monomeric fusion proteins covalently linked
together by
disulfide bonds formed between cysteine residues present in each monomeric
fusion
protein. The polypeptide sequence of each mature Orencia fusion protein
monomer is
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shown in SEQ ID NO:164 and is composed of the following segments: a WT human
CTLA-4 extracellular domain (amino acid residues 1-124), linker sequence
(amino acid
residue 125), and a mutant IgG1 Fc polypeptide (amino acid residues 126-357).
Each
Orencia fusion protein monomer has a structure similar to that of the LEA29Y-
Ig fusion
protein monomer shown schematically in Figure 2C, except that the LEA29Y ECD
is
replaced with WT human CTLA-4 ECD, and no signal peptide is present in either
Orencia fusion protein monomer, because each monomer is a secreted or mature
fusion
protein. The polypeptide sequence of the non-mature form of an Orencia
monomer
(which includes a signal peptide) and a nucleic acid sequence encoding the non-
mature
form of an Orencia fusion protein monomer are shown in SEQ ID NO:8 and SEQ ID
NO:7. respectively, of U.S. 7,094,874. Methods of making and using the Orencia
fusion
protein are also disclosed in U.S. 7,094,874.
Creation of DNA Sequences Encoding Mutant CTLA-4 Polvpeptides.
Directed evolution methods were used to generate libraries of recombinant non-
naturally-occurring polynucleotides encoding recombinant mutant CTLA-4
extracellular
domain polypeptides. The protein and nucleotide sequences of a number of
naturally-
occurring mammalian CTLA-4 homologues are known. See, e.g., National Center
for
Biotechnology Information (NCBI). Sequence diversity identified in a variety
of
naturally-occurring mammalian CTLA-4 extracellular domain homologues was used
in
directed evolution methods to generate libraries of recombinant
polynucleotides encoding
mutant CTLA-4 ECD domain polypeptides. Directed evolution procedures include,
e.g.,
in vitro recombination and mutagenesis procedures as substantially described
in Stemmer,
Proc. Natl. Acad. Sci. USA 91:10747-10751 (1994); Chang et al., Nature Biotech
17:793-
797 (1999); Int'l Pat. Appn. Publ. No. WO 98/27230; and U.S. Pat. Nos.
6,117,679 and
6,537,776.
Creation of Libraries of DNA Sequences Encoding Mutant CTLA-4 Polypeptides.
Mutant DNA sequences encoding recombinant mutant CTLA-4 ECD polypeptides
were amplified from assembly reactions by PCR using forward and reverse
primers
designed based on sequence homology. The primers were designed, made, and
assembled
using standard procedures well known by those of ordinary skill in the art and
included
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stop and start codons and restriction sites as necessary. The PCR
amplification procedures
employed are also well known in the art. See, e.g., Berger, Ausubel, and
Sambrook, all
supra. Exemplary forward and reverse primers include, but are not limited, to
the
following: forward primer (5'-
CTATTGCTACGGCCGCTATGGCCMTKCACGTCGCTCAACCAGCCGTCGTACTC
GCGTCC-3') (SEQ ID NO:191) and reverse primer (5'-
GTGATGGTGATGGTGTGCGGCCGCATCAGA-3' ) (SEQ ID NO:192). 5 0 of
assembly reaction was used as template in a 100 0 PCR reaction with 1 M
forward and
reverse primers, Taq buffer (Qiagen; #201225) and 200 jiM dNTPs for 15
amplification
cycles (94 C 30 s; 50 C 30 s; 72 C 40 s). Amplified DNA encoding mutant CTLA-4
ECD polypeptides was digested with restriction enzymes (Sfi/ and Nod) and the
fragments
were separated by agarose-gel electrophoresis, purified using the Qiaquick Gel
Extraction
Kit (Qiagen, #28704) as per manufacturer's recommendation, and ligated into
similarly
digested phage-display vector pSB0124 (procedure similar to that described in
Chang et
al., Nature Biotech 17:793-797 (1999)). The resulting library ligation was
transformed by
electroporation into TOP10 E. coli cells (Invitroeen, Inc; #C4040-50)
following the
manufacturer's recommend conditions. Transformed cells were incubated in LB
(Luria
broth media) containing 50 p.g/mIcarbenicillin at 250 rpm overnight at 37 C
and then
used to make a maxiprep (Qiagen; #12362) stock of library DNA as per the
manufacturer's recommended conditions.
Screening of Phage Libraries Displaying Mutant CTLA-4 Polypeptides Having
Improved
Human CD80 and/or Human CD86 Binding Avidities
Generation of Phage Displaying Libraries of Mutant CTLA-4 Polypeptides.
Library DNA (e.g., a library of DNA sequences encoding CTLA-4 ECD mutants)
was transformed by electroporation into TG-1 E. coli cells (Stratagene;
#200123) as per
the manufacturer's recommended conditions. The culture was grown under
phagemid-
selection conditions (LB medium containing carbenicillin at 50 ii,g/m1) for 1-
2 generations,
infected with helper phage Ml 3K07 (at a multiplicity of infection level of 5-
10), and
incubated with shaking at 250 rpm overnight at 37 C under dual selection for
phagemid
(carbenicillin at 50 [ig/m1) and helper phage (kanamycin at 70 gimp. The
cultures were
clarified by centrifugation (6000 rpm, 15 mm, 4 C in a Sorvall 600TC rotor)
and phage
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particles were precipitated by incubating 32 ml culture supernatant with 8 ml
PEG/NaCI
solution (20% PEG-8000; 2.5 M NaCI) on ice for 30 min followed by
centrifugation (9500
rpm, 40 mm, 4 C in a Sorvall 600TC rotor). The phage pellet was suspended in 1
ml PBS
containing 1% BSA (bovine serum albumin, Sigma; #A7906), transfen-ed to a
microfuge
tube, and clarified by centrifugation (max speed, 5 min, RT in an Eppendorf
table-top
centrifuge).
Panning of CTLA-4 Mutant Plzage Libraries.
Pha2e libraries were panned in up to five rounds against hCD80-Ig or hCD86-Ig
fusion proteins using standard conditions. See, e.g., Lowman, et al.,
Biochemistry
12;30(45):10832-10838 (1991); Smith, G.P. et al., Chem. Rev. 97:391-410
(1997). Each
round of panning included: (a) binding of phage displaying mutant CTLA-4 ECD
polypeptides to hCD80-Ig or hCD86-Ig ligands; (b) removal of unbound phage;
(c) elution
of bound phage; and (d) amplification of eluted phage for the next round of
panning. An
aliquot of phage from each round was transduced into E. coli cells to obtain
individual
transductant colonies.
Identification of CTLA-4 Mutants having Improved Binding Avidities to Human
CD80 and/or Human CD86 by Phage ELISA.
Individual colonies obtained from each round of panning were inoculated into
96-
well culture plates (NUNC; #243656) containing 150 Ill/well of 2 x YT (yeast-
tryptone)
media containing 50 1g/m1 carbenicillin and incubated at 250 rpm overnight at
37 C. The
overnight cultures were used to inoculate deepwell blocks (Scienceware;
#378600001)
containing 600 pl/well of the same media. Cultures were incubated at 250 rpm
for 2 hrs at
37 C, infected with Ml 3K07 helper phage (multiplicity of infection (moi) 5-
10) and then
incubated at 250 rpm at overnight at 37 C under dual selection for phagemid
and helper
phage markers (carbenicillin at 50 ug/m1 and kanamycin at 70 ug/ml,
respectively).
Cultures were clarified by centrifugation at 4000 rpm for 20 min at 4 C in a
Beckman GH
3.8 rotor. ELISA plates (NUNC; #449824) were coated by addition of 50 gl/well
PBS
containing 10 ug/m1 hCD80-Ig or hCD86-Ig and incubated overnight at 4 C.
Plates were
washed three times with 200 ul/well PBST and blocked by addition of 200
u1/well PBS
containing 3% non-fat dry milk and incubation at RT for 1 hour (hr). 25
ul/well of phage
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supernatants from the deepwell block was transferred to ELISA plates
containing 25
p1/well 6 % non-fat dry milk and plates were incubated for 1 hr at room
temperature (RT).
Plates were washed three times with 200 1/well PBST and incubated with 50
p1/well
HRP-conjugated anti-M13 monoclonal antibody (GE Healthcare, #27-9421-01)
diluted
1:5000 in PBST containing 3% non-fat dry milk for 1 hr at RT. Plates were
washed three
times with 200 [tl/well PBST and signal was detected using a TMB substrate kit
(Pierce;
#34021) according to manufacturer's recommended conditions. Mutant CTLA-4 ECD
polypeptides exhibiting increased binding avidity to human CD80 and/or human
CD86 (as
measured by an increased avidity to hCD80-Ig and/or hCD86-Ig), compared to the
binding
avidity of human CTLA-4 to human CD80 and/or human CD86 (as measured by the
binding avidity of human CTLA-4 ECD to hCD80-Ig and/or hCD86-Ig), were
selected for
further analysis.
EXAMPLE 3
Creation of an IgG2 Fc Fusion Protein Vector.
A plasmid IgG2-Fc fusion protein expression vector was created to produce a
fusion protein comprising a mutant CTLA-4 ECD polypeptide of the invention and
human
IgG2 Fc polypeptide. DNA encoding the human IgG2 Fc polypeptide was generated
by
PCR amplification of human leukocyte cDNA (BD Biosciences, Cat. #HL4050AH)
using
forward primer (5'-AAGCTGTCACCGGTGGATCGATCCCGAACCCTGCCCTGAT
TCTGATGAGCGCAAATGTTGTGTCGAGTGCCCACCGT-3') (SEQ ID NO:189) and
reverse primer (5'- CAGAATTCATTATTTACCCGGAGACAGGGAGAGGCT
CTTCTG-3') (SEQ ID NO:190). The primers were designed, made, and assembled
using
standard techniques well known by those of ordinary skill in the art and
included stop and
start codons and restriction sites as necessary. The PCR amplification
procedures
employed are also well known in the art. See, e.g., Berger, Ausubel, and
Sambrook. all
supra. 50-10Ong of cDNA was used as template in a 100 p1 PCR reaction with 1
i_tM
forward and reverse primers, Taq buffer (Stratagene; #200435) and 200 IVI
dNTPs for 25
amplification cycles (94 C, 30 s; 55 C, 30 s; 72 C, 60 s). The PCR product was
purified
by QiaQuick PCR Spin Columns (Qiagen #28106) as per the manufacturer's
recommended conditions and digested with restriction enzymes Agel and EcoRl.
The
PCR digestion fragment was separated by agarose-gel electrophoresis and
purified using
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Qiaquick Gel Extraction Kit (Qiagen, #28704) as per the manufacturer's
recommended
conditions. A modified version of the pCDNA3.1-LEA vector (described above),
which
contains an AgeI restriction site in the CTLA-4 signal sequence (introduced as
a silent
mutation), may be digested with Agel and EcoRI and ligated to the fragment
mentioned
above. The ligation is transformed into One-shot TOP 10 E. coli cells
(Invitrogen Cat.
#C4040-03) as per the manufacturer's recommended conditions. Transformed cells
are
incubated in LB (Luria broth media) containing 50 i.ig/mlcarbenicillin at 250
rpm
overnight at 37 C and then used to make a maxiprep (Qiagen; #12362) stock of
plasmid
DNA as per the manufacturer's recommended conditions.
The resulting plasmid expression vector is designated as the pCDNA IgG2 Fc
fusion protein expression vector. This vector is identical to the pCDNA mutant
CTLA-4-
IgG2 plasmid vector shown in Figure 1 except that the nucleic acid sequence
encoding the
mutant CTLA-4 ECD polypeptide is removed. The nucleic acid sequence encoding
the
signal peptide in pCDNA IgG2 Fc fusion vector (which in Figure 1 can be any
suitable
signal peptide-encoding nucleotide sequence) is a nucleic acid encoding the
human
CTLA-4 signal peptide (SEQ ID NO:181 or SEQ ID NO:215). This IgG2 Fc fusion
vector does not include any nucleic acid encoding a mutant CTLA-4 ECD
polypeptide of
the invention or any other CTLA-4 ECD polypeptide.
Cloning of Nucleotide Sequences Encoding Mutant CTLA-4 Polypeptides into the
IgG2
Fc Fusion Vector.
To produce mutant CTLA-4 polypeptides as soluble Fc fusion proteins, DNA
sequences encoding mutant CTLA-4 ECD polypeptides identified as having
improved
binding avidities to human CD80 and/or human CD86 (as compared to the binding
avidity
of human CTLA-4-ECD to human CD80 and/or human CD86) from the phage library
screening were each cloned into the IgG2 Fc fusion protein vector described
above using,
e.g., the following procedure.
DNA sequences encoding mutant CTLA-4 ECD polypeptides exhibiting higher
binding avidities to hCD80-Ig and/or hCD86-Ig were first recovered from the
phage
display vector by PCR amplification using forward and reverse primers designed
based on
sequence homology to a number of nucleotide residues (e.g., 30-60 nucleotides)
at the N-
and C-termini of the mutant CTLA-4 ECD polypeptides and standard procedures
known
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in the art. See, e.g., procedures described in. e.g.. Berger. Ausubel, and
Sambrook, all
supra. For example, in one exemplary aspect, DNA sequences encoding mutant
CTLA-4
ECD polypeptides were recovered from the phage display vector by PCR
amplification
using forward primer (5'- GGAATACCGGTTTTTTGTAAAGCCATGCACGTCG
CTCAACCAGCCGTCGTACTC-3') (SEQ ID NO:191) and reverse primer (5'-
GGCACTCAGATCTACGTCATCGATCCCGAA-3') (SEQ ID NO:192). 10 nanograms
(ng) of plasmid DNA (phage display vector containing a mutant CTLA-4 ECD-
encoding
nucleotide sequence) was used as template in a 100 t1 PCR reaction with 1 i_tM
forward
and reverse primers described above, Taq buffer (Stratagene; #200435) and 200
[iM
dNTPs for 25 amplification cycles (94 C, 30 s; 55 C, 30 s; 72 C, 60 s). The
PCR product
was purified by QiaQuick PCR Spin Columns (Qiagen #28106) as per the
manufacturer's
recommended conditions and digested with restriction enzymes Agel and Clal.
The
fragments were separated by agarose-gel electrophoresis, purified using
Qiaquick Gel
Extraction Kit (Qiagen, #28704) as per the manufacturer's recommended
conditions. and
ligated into similarly digested plasmid IgG2 Fc Fusion vector. The ligation
was
transformed into One-shot TOP10 E. coli cells (Invitrogen Cat. #C4040-03) as
per the
manufacturer's recommended conditions. Transformed cells were incubated in LB
(Luria
broth media) containing 50 vg/mlcarbenicillin at 250 rpm overnight at 37 C and
then
used to make a maxiprep (Qiagen; #12362) stock of plasmid DNA as per the
manufacturer's recommended conditions.
The resulting plasmid expression vector, which comprises a nucleic acid
encoding
a mutant CTLA-4-IgG2 fusion protein of the invention, is designated as the
pCDNA
mutant CTLA-4 ECD IgG2 Fc plasmid expression vector. A schematic diagram of
this
vector is shown in Figure 1. This vector includes a Bla promoter; ampicillin
resistant
gene; pUC origin; SV40 polyadenylation (poly A) signal sequence; fl origin;
SV40
promoter; neomycin resistance gene; CMV promoter to facilitate expression of a
mutant
CTLA-4-Ig fusion protein of the invention (comprising, e.g., human CTLA-4
signal
peptide, mutant CTLA-4 ECD polypeptide, and human IgG2 Fc polypeptide); a
nucleic
acid sequence encoding a human CTLA-4 signal peptide (SEQ ID NO:181 or SEQ ID
NO:215); a nucleic acid sequence encoding a mutant CTLA-4 ECD polypeptide of
the
invention (including, but not limited to, e.g., a nucleotide sequence encoding
any one of
SEQ ID NOS:80-152); an exemplary nucleic acid sequence encoding a human IgG2
Fc
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polypeptide is shown in SEQ ID NO:183 or SEQ ID NO:217; and a bovine growth
hormone (bGH) poly A termination signal sequence. The nucleic acid sequence of
SEQ
ID NO:183 encodes the hIgG2 Fc polypeptide with the C-terminal lysine (K)
residue
(SEQ ID NO:184); the nucleic acid sequence of SEQ ID NO:217 encodes the hIgG2
Fc
polypeptide without the C-terminal lysine residue (SEQ ID NO:218).
The plasmid IgG2 Fc fusion protein vector can also be used to produce a human
CTLA-4-IgG2 ("hCTLA-4-Ig") fusion protein. In this instance, a nucleic acid
sequence
encoding human CTLA-4 ECD SEQ ID NO:193) is cloned into the plasmid IgG2
Fc
fusion protein vector using standard cloning procedures similar to those
described above
in place of the nucleotide sequence encoding the mutant CTLA-4 ECD. The hCTLA-
4-Ig
fusion protein typically exists in solution as a dimeric fusion protein
comprising two
identical monomeric mature hCTLA-4-Ig fusion proteins. In this instance, each
monomeric mature hCTLA-4-Ig fusion protein comprises a human CTLA-4 ECD (SEQ
ID NO:159) fused at its C-terminus to the N-terminus of a human IgG2 Fc (SEQ
ID
NO:218 or SEQ ID NO:184). The two hCTLA-4-Ig monomers are covalently linked
together by disulfide bonds formed between cysteine residues in each monomer,
thereby
forming the hCTLA-4-Ig fusion protein dimer. The mature hCTLA-4-Ig fusion
protein
dimer is the form of the fusion protein used in the assays described in these
Examples,
unless explicitly stated otherwise.
We have found experimentally that a human CTLA-4-Ig fusion protein or mutant
CTLA-4-Ig fusion protein made in CHO cells by transfecting an expression
vector
comprising a nucleotide sequence encoding the hCTLA-4-Ig or mutant CTLA-4-Ig
fusion
protein and the hIgG2 Fc polypeptide shown in SEQ ID NO:184 does not typically
include
the predicted C-terminal lysine (K) residue, as determined by LCMS analysis;
thus, the
hIgG2 Fc polypeptide sequence of a hCTLA-4-IgG2 or a mutant CTLA-4-IgG2 is
that
shown in SEQ ID NO:218, which hIgG2 Fc polypeptide sequence does not typically
include the C-terminal lysine residue as compared to the polypeptide sequence
shown in
SEQ ID NO:184.
Transient Transfection of COS Cells.
COS-7 cells were grown to 80-90% confluence in T-175 flasks containing 40 ml
Growth Medium (DMEM/F12 medium (Invitrogen, Cat. #10565-018) supplemented with
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10% FBS (Hyclone Cat. #SV30014.03) and lx PSG (penicillin, streptomycin and
s,,lutamine) (Invitrogen, Cat. #10378-016)). Immediately prior to transfection
of the cells
with a plasmid expression vector, the medium was removed and replaced with 35
ml
Expression Medium (OptiMem media (Gibco #51985) containing lx PSG). Plasmid
DNA
(10 lig) (e.g., a pCDNA mutant CTLA-4 ECD IgG2 Fc expression vector encoding a
mutant CTLA-4-IgG2 fusion protein of the invention) was mixed with FuGENE6
transfection reagent (Roche #11 815 075 001) in a 1:3 volume ratio and added
to 1 ml of
Growth Medium. This mixture was then added slowly to the T-175 flask and
swirled
gently to mix. After incubation at 37 C for 3 days, the media was harvested,
fresh
Expression Medium was added, and the cultures were incubated for an additional
3 d.
A similar procedure can be used to make COS-7 cells transfected with a similar
plasmid vector encoding human CTLA-4-IgG2 or a pCDNA3.1-LEA plasmid vector
encoding LEA29Y-Ig.
Purification of Proteins.
Supernatants from transfection cultures (e.g., comprising cells transfected
with a
pCDNA mutant CTLA-4 ECD IgG2 Fc vector encoding mutant CTLA-4-Ig fusion
protein) were clarified by centrifugation at 1000x g for 10 min at RT and
filtration through
0.2 p.m membranes (Nalgene, VWR #73520-982). Proteins were purified by Protein-
A
affinity chromatography using an AKTA Explorer HPLC system (GE Healthcare). A
mutant CTLA-4-Ig fusion protein was bound to Hitrap Protein A FF columns (GE
Healthcare, #17-5079-01) in PBS buffer, washed with the same buffer, eluted
with 100
mM citric acid buffer (pH 4.0), and then neutralized by addition of 1/10
volume of 2M
Tris base. The buffer in the protein solution was finally exchanged to PBS by
dialysis
using 10 kDa MWCO membranes (Pierce, Cat. #PI66810).
A similar procedure can be used to purify human CTLA-4-IgG2 or LEA29Y-Ig
fusion proteins.
Evaluation of Protein Quality.
SDS/PAGE Analysis.
The apparent molecular weight (MW) of a purified mutant CTLA-4-Ig fusion
protein of the invention was measured by SDS/PAGE analysis under non-reducing
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conditions. Under non-reducing conditions, a mutant CTLA-4-Ig fusion protein
of the
invention typically exists as a dimeric fusion protein comprising two
monomeric mutant
CTLA-4-Ig fusion proteins. In one aspect, the dimer is a homodimer comprising
two
identical mutant CTLA-4-Ig fusion protein monomers. In one aspect, each CTLA-4-
Ig
fusion protein monomer comprises a mature/secreted mutant CTLA-4 ECD fused at
its C-
terminus to the N-terminus of a human IgG2 Fc polypeptide. The two mutant CTLA-
4-Ig
monomers are covalently linked together by disulfide bonds formed between
cysteine
residues in each monomer. The homodimer is the form of the mutant fusion
protein
molecule of the invention typically described in these Examples, unless
explicitly stated
otherwise. The data shown in these Examples pertain to mutant CTLA-4-Ig fusion
protein
homodimers, unless explicitly stated otherwise.
SDS/PAGE analyses were performed as follows. 2 [tg of purified protein was
added to 20 tl LDS Sample Buffer (Invitrogen #NP0007) and run through NuPAGE 4-
12% Bis-Tris gels (Invitrogen #NP0321BOX) in lx MES sodium docecyl sulfate
(SDS)
/PAGE running buffer (Invitrogen #NP0002) following the manufacturer's
recommended
conditions. Gels were stained by incubation in 50 ml SimplyBlue SafeStain
(Invitrogen
#LC6060) for 1 hr with gentle agitation at RT. Gels were de-stained by two
incubations
with 200 ml water for 1 hr with gentle agitation at RT and processed in drying
buffer (Bio
RAD 161-0752) according to the manufacturer's recommended conditions.
A representative SDS/PAGE gel of two exemplary mutant CTLA-4-Ig fusion
protein homodimers of the invention (designated as clones D3 and D4) and the
Orencia
fusion protein, which serves as a comparative control, is presented in Figure
3. The D3-Ig
fusion protein dimer comprises two identical D3-Ig fusion protein monomers
that are
covalently linked by disulfide bonds formed between cysteine residues in each
D3-Ig
monomer. Each D3-Ig monomer comprises a mutant CTLA-4 ECD polypeptide (named
"D3") comprising the polypeptide sequence shown in SEQ ID NO:61 fused directly
(i.e.,
with no "linker" amino acid residue(s)) at its C-terminus to the N-terminus of
the hIgG2
Fc polypeptide shown in SEQ ID NO:218. The D4-Ig fusion protein dimer
similarly
comprises two identical D4-Ig monomers that are covalently linked by disulfide
bonds
formed between cysteine residues in each D3-Ig monomer. Each monomeric D4-IgG2
fusion protein comprises a mutant CTLA-4 ECD polypeptide (named "D4")
comprising
the polypeptide sequence shown in SEQ ID NO:62 fused directly (i.e., with no
"linker"
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amino acid residue(s)) at its C-terminus to the N-terminus of the hIgG2 Fc
polypeptide
sequence shown in SEQ ID NO:218.
As explained above, we have found experimentally that a mutant CTLA-4-Ig,
fusion protein made in CHO cells using a vector comprising a nucleotide
sequence
encoding the predicted hIgG2 Fc polypeptide shown in SEQ ID NO:184 does not
typically
include the predicted C-terminal lysine (K) residue, as determined by LCMS
analysis;
thus, the hIgG2 Fc polypeptide sequence of a mutant CTLA-4-IgG2 described
herein is
that shown in SEQ ID NO:218, which hIgG2 Fc polypeptide sequence does not
typically
include the C-terminal lysine residue, as compared to the polypeptide sequence
shown in
SEQ ID NO:184.
SDS/PAGE analyses were performed on all protein preparations to verify protein
quality in terms of apparent molecular weight, protein concentration, and
purity. The
results of the SDS/PAGE analyses were similar for all protein preparations.
From the
exemplary gel results shown in Figure 3, purified D3-IgG2 and D4-IgG2 fusion
protein
dimers have an apparent MW of approximately 80 kDa, which is consistent with
the
predicted MW of the exemplary homodimeric mutant CTLA-4-IgG2 fusion protein
structure depicted in Figure 10 (predicted MW = 78-79 kDa). (Purified mutant
CTLA-4-
IgG2 protein monomers typically have apparent MWs of 39-40 kDa.) The protein
bands
in the gel shown in Figure 3 have been stained with equivalent intensities;
this confirms
the accuracy of measuring protein concentration for different samples. As for
protein
purity, a lower MW band can be observed in Figure 3 at an apparent MW of
approximately 44 kDa, which is consistent with the predicted MW of a monomeric
IgG2
fusion protein. The relative intensity of this lower MW band is consistently
low and is
estimated to be less than 5% of the total protein.
Analogous SDS/PAGE analyses can be used to evaluate the purity of human
CTLA-4-IgG2 or LEA29Y-Ig fusion proteins produced using methods similar to
those
describe above.
Endotoxin Analysis.
Endotoxin levels of mutant CTLA-4 fusion proteins were measured using a QCL-
1000 limulus amoebocyte lysate assay kit (Cambrex #50-648U) following the
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manufacturers recommended conditions. The maximum endotoxin level for proteins
used
in cell-based assays was set at 10 endotoxin units (EU)/mg protein.
Analogous analyses can be used to measure the endotoxin levels of human CTLA-
4-IgG2 or LEA29Y-Ig protein preparations.
Size Exclusion Chromatography (SEC) Analysis.
Protein aggregation levels (including aggregation levels of mutant CTLA-4
polypeptides and control polypeptides) were measured by size exclusion
chromatography
using a Dionex BioLC system (Dionex). Protein (5 [(g) was run through a Tosoh
G3000Wx1 column (Tosoh Bioscience) in PBS running buffer using a 20 min
isocratic run
and detection by absorbance (A) at 214 nanometers (nm). The maximum level of
aggregation for protein used in further assays was set at 10%.
SEC analysis was performed on all protein preparations to verify protein
quality in
terms of protein aggregation levels. The results were similar for all protein
preparations
and a representative elution profile from an SEC analysis of a mutant CTLA-4-
Ig fusion
protein dimer (D3-Ig) is shown in Figure 4. The y-axis shows milliAbsorbance
units
(mAU); the x-axis shows elution time in minutes. The structure of the D3-Ig
dimer is
explained above in the "SDS/PAGE Analyses" section. This purified mutant CTLA-
4-Ig
dimer is largely homogeneous in size and does not contain high levels of
aggregated
species. Other mutant CTLA-4-Ig fusion proteins of the invention were
similarly analyzed
and showed similar results (data not shown). Purified mutant CTLA-4-Ig fusion
proteins
of the invention were found to be homogenous in size and did not contain high
levels
(>10%) of aggregated proteins. It is important to verify the aggregation
states of the
purified mutant CTLA-4-Ig fusion proteins of the invention because highly
aggregated
mutant CTLA-4-Ig fusion proteins may bind with higher avidity to human CD80
and/or
human CD86 molecules and thus may exhibit higher biological activity.
EXAMPLE 4
Measuring Binding Avidities of Mutant CTLA-4-Ig Fusion Proteins to Human CD80-
murine Ig (hCD80-mIg) and human CD86-murine Ig (hCD86-mI2) Fusion Proteins
Using
Surface Plasmon Resonance (SPR) (BiacoreThi Analysis).
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This example describes a procedure for screening mutant CTLA-4-Ig fusion
proteins for improved binding avidity to hCD80-mIg and/or hCD86-mIg ligands
using a
Biacore interaction analysis. In the nomenclature used to describe this type
of analysis,
the immobilized binding partner is referred to as the "ligand", and the
binding partner in
the mobile phase is referred to as the "analyte". Fusion proteins containing
an Ig domain
typically form dimeric structures in solution by virtue of strong association
between two Ig
domains. Unless indicated otherwise, such dimeric conformations are expected
to exist
for the fusion proteins described in this Example (i.e., mutant CTLA-4-Ig,
Orencia
fusion protein, LEA29Y-Ig, hCD80-mIg, and hCD86-mIg). The term "avidity"
typically
relates to the strength of binding between dimeric analytes (e.g., mutant CTLA-
4-Ig fusion
proteins) and dimeric ligands (e.g., hCD80-mIg or hCD86-mIg fusion proteins).
The
increases in binding avidity described for mutant CTLA-4-Ig fusion proteins
result from
increases in binding affinity between each CTLA-4 ECD domain and its
corresponding
ligand. The strength of binding avidity is typically described in terms of the
equilibrium
dissociation constant (KD), which describes the molar concentration of analyte
at which
50% of available ligand is bound at equilibrium.
In this screening method, Biacore sensor chips were derivatized with hCD80-mIg
or hCD86-mIg ligands and mutant CTLA-4-Ig fusion proteins in buffer were
allowed to
flow over the ligand-coated sensor chips. The ability of a mutant CTLA-4-Ig
fusion
protein molecule to bind to a specific binding partner (i.e., hCD80-mIg or
hCD86-mIg)
was evaluated. Control fusion proteins (i.e., human CTLA-4-IgG2 fusion
protein,
Orencia fusion protein, and mutant LEA29Y-Ig fusion protein) were also
allowed to
flow over the ligand-coated sensor chips and the abilities of these molecules
to bind to
hCD80-mIg or hCD86-mIg were similarly evaluated for comparison. Using the
Biacore
system, the association (lcon) and dissociation (lcoff) rate constant of a
protein of interest
binding to hCD80-mIg or hCD86-mIg ligands can be evaluated and used to
calculate the
equilibrium dissociation constant, KD. The human CTLA-4-IgG2 fusion protein,
which
comprises the WT human CTLA-4 ECD polypeptide fused to the human IgG2
polypeptide, can serve as a wild-type human CTLA-4-Ig "control". In addition
or
alternatively, because the Orencia fusion protein is composed of the WT human
CTLA-4
ECD polypeptide fused to a modified IgG1 Fc polypeptide, it also effectively
serves as a
wild-type human CTLA-4-Ig control for comparative purposes. Mutant CTLA-4-Ig
fusion
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proteins having increased binding avidities for hCD80-mIg and/or hCD86-mIg,
compared
to human CTLA-4-IgG2, Orencia fusion protein, and/or LEA29Y-Ig, were
identified.
As discussed in greater detail below, the increased binding avidity of a
mutant CTLA-4-Ig
fusion protein of the invention for hCD80-mIg and/or hCD86-mIg, as compared to
the
binding avidity of Orencia fusion protein (i.e., hCTLA-4-IgG1) and/or LEA29Y-
Ig for
hCD80-mIg and/or hCD86-mIg, was not due to differences between IgG2 present in
the
mutant CTLA-4-Ig molecules and the mutant 1gG1 present in the Orencia or
LEA29Y-Ig
molecules.
All BiacoreTm analyses were performed on a BiacoreTM 2000 system (GE
Healthcare) at room temperature (RT. 25 C). HBS-EP buffer (10 mM HEPES (pH
7.4),
150 mM NaC1, 3 mM EDTA, 0.005% surfactant P20) was used as the flow buffer for
all
experiments.
Standard Kinetic Assay.
The standard kinetic assay measures binding kinetics of dimeric ligand (e.g.,
hCD80-mIg fusion protein or hCD86-mIg fusion protein) coated to sensor chips
and
dimeric analytes (e.g., mutant CTLA-4-Ig fusion proteins of the invention) in
the mobile
phase. Rabbit anti-mouse IgG antibody (GE Healthcare, #BR-1005-14) was
immobilized
on CM5 sensor chips (GE Healthcare, #BR-1000-14) according to the
manufacturer's
protocol. Antibody was diluted to 30 lig/1711in immobilization buffer (10mM
sodium
acetate, pH 5.0 (BR-1003-51)). At a flow rate of 5 tl/minute, sensor chip CM5
was
activated with a 35 [t.1 injection of a mixture of 1-Ethy1-343-
dimethylaminopropyl]carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide
(NHS) (made by mixing equal volumes of 11.5 mg/ml EDC and 75 mg/ml NI-IS) (GE
Healthcare, #BR-1000-50), followed by a 35 RI injection of undiluted antibody.
Un-
reacted sites were quenched with 35 [L1 of 1M ethanolamine-HCL, pH 8.5 (GE
Healthcare,
#BR-1000-50). This procedure typically yielded 15.000 response units (RU) of
coupled
antibody. CTLA-4 ligands human CD80-murine Ig (hCD80-mIg) (Ancell, #510-820)
or
human CD86-murine Ig (hCD86-mIg) (Ancell, #509-820) were bound to antibody-
coated
sensor chips by injection of 10 111 or 16 1.1,1, respectively, ligand solution
(2 gAg/nril protein in
HBS-EP buffer [10mM HEPES pH 7.4, 150mM NaC1, 3 mM EDTA, 0.005% (v/v)
surfactant P-20, GE Healthcare, #BR-1001-88]) at a flow rate of 10 p1/min.
Ligand
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capture levels were typically 135-170 RU. Mutant CTLA-4-Ig proteins (or were
diluted in
HBS-EP buffer and flowed over ligand-coated sensor chips for 2 mm at 30
1/min,
followed by 5 mm incubation with HBS-EP buffer containing no protein at the
same flow
rate. For mutant CTLA-4-Ig fusion proteins having very slow dissociation rates
from
hCD86-mIg, kinetic assays were also conducted using longer dissociation times
(e.g., 20
min). Rmax signal levels for mutant CTLA-4-Ig proteins ranged from
approximately 70-
100 RU. Regeneration between cycles was performed by 3 min incubation with 10
mM
glycine buffer (pH 1.7) at 50 [d/min. New chips were subjected to 4-5 cycles
of
capture/binding/regeneration prior to use in actual experiments. Data from a
reference cell
containing rabbit anti-mouse IgG capture antibody alone was subtracted from
data
obtained from flow cells containing captured hCD80-mIg or hCD86-mIg.
Typically, 8
dilutions of mutant CTLA-4-Ig proteins ranging from 500 nM to 0.2 nM were
analyzed
against a blank reference (HBS-EP buffer alone).
Sensorgram traces from a typical Biacore analysis are shown in Figure 5. This
figure shows the response (RU) over time (in seconds (s)) generated by the
binding of the
following three fusion proteins to the hCD86-mIg fusion protein: (1) Orencia
fusion
protein (serving as a control and for comparison) (Bristol-Myers Squibb Co.;
see, e.g.,
Larson C.P. et al., Am. J. Trans. 5:443-453 (2005)); (2) LEA29Y-Ig fusion
protein (for
comparison); and (3) an exemplary mutant CTLA-4-Ig fusion protein of the
invention
designated "clone D3" (also termed D3-IgG2). The D3-IgG2 fusion protein
comprises
two identical monomeric fusion proteins that are covalently linked together by
one or
more disulfide bonds formed between cysteine residues in each monomer. See the
discussion in the "SDS/PAGE Analyses" section above. Each monomeric fusion
protein
comprises a mature mutant CTLA-4 ECD polypeptide shown in SEQ ID NO:159
covalently fused at its C-terminus to the N-terminus of the human IgG2
polypeptide
shown in EQ ID NO:184 or 218. Other dimeric fusion proteins of the invention
may
comprise structures similar to that of the dimeric D3-IgG2 fusion protein ¨
except that the
D3 mutant CTLA-4 ECD polypeptide of each monomeric fusion protein is replaced
by a
different mutant CTLA-4 ECD polypeptide.
The association phase reflects the binding between the analyte of interest and
the
ligand of interest. In Figure 5, the association phase for each analyte is
represented by the
curve at times prior to the time marked by the arrow and is characterized by
the binding of
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analyte (D3-IgG2, Orencia fusion protein, or LEA29Y-Ig) to the hCD86-mIg
ligand.
The rate at which an analyte associates with the hCD86-mIg ligand is reflected
in the
curve ¨ see, e.g., the sharp rate of increase in the response units beginning
at about 510
seconds.
The dissociation phase of the analysis begins at the time marked by the arrow
in
Figure 5. During the dissociation phase, the analyte and ligand dissociate
from their
bound conformation. In Figure 5, the rate at which an analyte dissociates from
the
hCD86-mIg ligand is represented by the decrease in response units (rate of
decrease of the
response units over time). Based on these data, the relative dissociation rate
constant
("off" rates, koff or kd) and association rate constants ("on" rates, kor, or
ka) can be
determined. The total avidity of the interaction can be described by the KD,
(koff)/ (koo).
Increased binding avidities are often manifested in slower dissociation rates.
If the slower
dissociation rate is accompanied by an equal, higher, or marginally slower
association rate,
such that the calculated equilibrium dissociation constant KD is lower, the
avidity will be
greater. In this case, a mutant CTLA-4-Ig fusion protein that has a binding
avidity for the
hCD86-mIg ligand that is greater than the binding avidity of the Orencia
fusion protein
for the same ligand will also have a slower dissociation rate from the ligand
than the
Orencia protein. A mutant CTLA-4-Ig fusion protein that has a binding avidity
for the
hCD86-mIg ligand that is greater than the binding avidity of LEA29Y-Ig for the
same
ligand will also have a slower dissociation rate from the ligand than LEA29Y-
Ig.
Figure 5 shows that the dissociation rate of LEA29Y-Ig from the hCD86-mIg
ligand is significantly slower than the dissociation rate of the Orencia
protein from the
same ligand. LEA29Y-Ig also has an association rate for binding to hCD86-mIg
similar to
that observed for the Orencia fusion protein. Thus, LEA29Y-Ig has a higher
avidity for
hCD86-mIg than does the Orencia protein. This finding is consistent with
previous
studies describing LEA29Y-Ig as having a higher binding avidity for the hCD86-
mIg
ligand than the Orencia fusion protein (Larson C.P. et al., Am. J. Trans.
5:443-453
(2005)). Figure 5 also shows that the mutant D3-IgG2 fusion protein of the
invention has
a slower dissociation rate from the hCD86-mIg ligand than either the Orencia
or
LEA29Y-Ig fusion protein. The D3-IgG2 fusion protein also has a similar (but
somewhat
faster) association rate for binding to hCD86-mIg ligand compared to the
association rates
of either the Orencia or LEA29Y-Ig fusion proteins for hCD86-mIg ligand.
Thus, the
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D3-IgG2 fusion protein exhibits a higher binding avidity for the hCD86-mIg
ligand than
either the Orencia or LEA29Y-Ig fusion protein. Therefore, the D3-IgG2 fusion
protein
is expected to bind to native CD86, including, e.g., CD86 as expressed in vivo
on APCs in
mammals, such as humans, with higher binding avidity. This view is further
supported by
the functional cell-based assays discussed in the Examples below.
Biacore analyses were performed using other mutant CTLA-4-Ig fusion proteins
of
the invention. In addition, Biacore analyses were performed using hCD80-mIg-
coated
sensor chips and mutant CTLA-4-Ig fusion proteins of the invention. The
dissociation
rates and binding avidities of these mutant molecules were determined and
compared to
the dissociation rates and binding avidities of the Orencia and LEA29Y-Ig
fusion
proteins. Representative results are shown in Tables 3 and 4 and discussed in
greater
detail below.
Standard Biacore Data Analyses.
After deletion of the regeneration and capture portions of the sensorgrams,
curves
were zeroed to a 5 s average of all curves approximately 10 s prior to sample
injection. A
blank curve was subtracted from each test curve. Data were analyzed by
BIAevaluation
software (v4.1, available from GE Healthcare) using the "Fit kinetics,
Simultaneous ka/ka"
function. The injection start time was defined as a time prior to the
association phase
where all curves were close to zero. Data selection for the association phase
began
approximately 10 s after the injection start time and ended approximately 10 s
prior to the
injection stop time. The injection stop time was defined as a time prior to
the appearance
of any signal spikes associated with the dissociation phase. The dissociation
phase was
selected to start 10 s after the injection stop time and included 280-295 s of
the 5 min
dissociation phase. The 1:1 Langmuir model describes the reaction A + B <=>
AB. This
model represents a single ligand binding to a single protein of interest
(e.g., receptor). The
1:1 Langmuir model from the BIAevaluation software was used to determine the
association rate constant (ka) and the dissociation rate constant (kd) and to
calculate the
equilibrium dissociation constant, KD. KD = kclika= KD = ([A] [13])4AB]. The
equilibrium
dissociation constant, KD, is equal to the inverse of the equilibrium
association constant,
KA. KD = 1/ KA. The rate equations for the reaction (analyte A plus ligand B
yielding
complex AB), where A = analyte injected, B = free ligand, and t = time, are:
d[B]/dt = -
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(ka [A][B] - kd [AB]) and d[AB]/dt = ka[A][B] - kd[AB]. Substituting R,
Biacore response
units (RU) at a given time, for [AB], Rmax-R for [B], and C (analyte
concentration) for
[A], the net rate expression in Biacore units is dR/dt = kaC(Rmax-R) ¨ kdR,
where R at tO
= 0, B[0] = Rmax, and AB[0] = 0 RU, with the total response = [AB] + RI. The
bulk shift
(RI) was set to zero, and Rmax, ka and kd were fit globally for all curves.
The standard kinetic assays and data analyses described above were performed
on
protein preparations of mutant CTLA-4-Ig fusion protein of the invention, as
well as
LEA29Y-Ig and Orencia fusion proteins. Tables 3 and 4 summarize the binding
data for
representative mutant CTLA-4-Ig fusion proteins of the invention.
Table 3 presents binding avidities of representative mutant CTLA-4-Ig fusion
proteins to hCD86-mIg, as measured by the standard Biacore assay described
above.
Specifically, Table 3 shows the name of each mutant CTLA-41g fusion protein;
the
sequence identification number (SEQ ID NO) corresponding to the polypeptide
sequence
of the monomeric mutant CTLA-4 ECD fusion protein; the equilibrium
dissociation
constant (KD (Molar (M)) determined based on the binding avidity of the mutant
protein to
the hCD86-mIg; and the binding avidity of each mutant CTLA-4-Ig to the hCD86-
mIg
relative to the binding avidity of the Orencia fusion protein to the hCD86-
mIg. This
relative binding avidity (shown in the far-right column) is shown as a fold
improvement in
binding avidity of the mutant fusion protein to the hCD86-mIg compared to the
binding
avidity of the Orencia fusion protein to the hCD86-mIg. Each mutant CTLA-4-Ig
fusion
protein of the invention in Table 3 typically exists in solution as a dimeric
fusion protein
comprising two identical monomeric fusion proteins, wherein each monomeric
protein
comprises a mutant CTLA-4 ECD polypeptide (e.g., named D1, D1T, D2, D3, D4,
etc.)
fused directly at its C-terminus to the N-terminus of an IgG2 Fe polypeptide
comprising
the sequence of SEQ ID NO:184 or 218. Each such dimeric mutant CTLA-4-1g can
be
made by using standard techniques known in the art. Alternatively, each such
dimeric
mutant CTLA-4-Ig fusion protein dinner can be made by using methods set forth
in
Example 3 above. Briefly, a nucleic acid sequence encoding a particular mutant
CTLA-4
ECD identified in Table 3 (e.g., a nucleic acid sequence encoding a mutant
CTLA-4 ECD
polypeptide sequence identified in Table 3) can be cloned into the IgG2 Fe
fusion vector,
mammalian cells can be transfected with the vector, and the resultant fusion
protein can be
expressed, purified, and evaluated as described in Example 3. An exemplary
nucleic acid
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sequence for each mutant CTLA-4 ECD is presented in the Sequence Listing
included
herewith. The Orencia fusion protein, which comprises two monomeric fusion
proteins,
each monomeric fusion protein comprising a wild-type human CTLA-4 ECD fused to
a
modified IgG1 Fc, serves as the reference, i.e., with the binding avidity to
hCD86-mIg set
to 1. The KD values for LEA29Y-Ig fusion protein and the human CTLA-4-Ig
fusion
protein are also shown. In addition, the fold improvement in hCD86-mIg binding
avidity
of the LEA29Y-Ig, compared to the hCD86-mIg binding avidity of the Orencia
protein is
also shown. The binding avidities of the CTLA-4-IgG2 and Orencia fusion
proteins for
hCD86-mIg are approximately equal, confirming that the differences between the
human
IgG2 polypeptide present in human CTLA-4-IgG2 and the modified IgG1 present in
the
Orencia protein contribute little, if at all, to the respective hCD86-mIg
binding affinities
of these molecules. As is discussed in greater detail in Example 5 below, we
have
confirmed that the differences in immunosuppressive functional activities
between mutant
CTLA-4-Ig polypeptides of the invention and the Orencia protein (or LEA29Y-
Ig)
cannot be attributed to their respective Ig Fc regions comprising different
IgG isotypes.
As shown in Table 3, representative mutant CTLA-4-Ig fusion proteins of the
invention have hCD86-mIg binding avidities that are: (1) at least about equal
to or greater
than the binding avidity of human CTLA-4-IgG2 ("hCTLA-4-IgG2") (which
comprises
two covalently linked monomeric fusion proteins, each such monomeric protein
comprising the human CTLA-4 ECD polypeptide fused to an IgG2 Fc polypeptide);
(2) at
least about equal to or greater than the binding avidity of the Orencia
protein to the
hCD86-mIg ligand; and/or (3) at least about equal to or greater than the
binding avidity of
the LEA29Y-Ig to the hCD86-mIg ligand. The fold improvement in binding avidity
to the
hCD86-mIg ligand relative to the binding avidity of the Orencia protein to
hCD86-mIg
is indicated for each CTLA-4-Ig mutant (4th column in Table 3).
A majority of mutant CTLA-4-Ig fusion proteins were found to have a rate of
dissociation from hCD86-mIg fusion protein that is slower than the rate of
dissociation of
the Orencia fusion protein from hCD86-mIg (data not shown). A number of the
mutant
CTLA-4-Ig fusion proteins were found to have a rate of association to hCD86-
mIg greater
than the rate of association of Orencia fusion protein to the same ligand
(data not
shown).
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All of the mutant CTLA-4-Ig fusion proteins shown in Table 3 had liCD86-mIg
equilibrium dissociation constants (1(0) that were lower than the hCD86-mIg
equilibrium
dissociation constant of human CTLA-4-IgG2 or Orencia fusion protein.
Furthermore,
most of the mutant CTLA-4-Ig fusion proteins shown in Table 3 had hCD86-mIg
equilibrium dissociation constants that were lower than hCD86-mIg equilibrium
constant
of LEA29Y-Ig.
All of the mutant CTLA-4-1g fusion proteins shown in Table 3 had binding
avidities for hCD86-mIg that are greater than the binding avidities of the
human CTLA-4-
IgG2 or Orencia fusion protein for hCD86-mIg (the calculated fold improvement
in
hCD86-mIg binding avidity relative to the Orencia fusion protein is shown the
4th
column of Table 3). Moreover, many of the mutant CTLA-4-Ig fusion proteins
shown in
Table 3 had binding avidities for hCD86-mIg that are greater than the binding
avidity of
LEA29Y-Ig for hCD86-mIg (4th column of Table 3).
A mutant CTLA-4-Ig of the invention that has a higher binding avidity to the
hCD86-mIg ligand than does the Orencia or LEA29Y-Ig fusion protein will
likely have
an increased in vivo immunosuppressive potency compared to the hCTLA-4-IgG2,
Orencia , or LEA29Y-Ig fusion protein, respectively, such as in, e.g.,
therapeutic and/or
prophylactic methods for suppressing an immune response in a subject (e.g., in
the in vivo
treatment of immune system diseases or disorders of mammals, such as e.g.,
humans, in
which immunoinhibition or immunosuppression is desirable), methods for
inhibiting
rejection of a tissue or organ transplant from a donor by a recipient (e.g.,
by a mammal,
such as, e.g., a human), and other methods described elsewhere herein.
Table 3.
SEQ ID NO* Binding Avidity
(e.g., of for hCD86-mIg
Fusion Protein hCD86-mIg. KD
mutant (Relative to
(dimer) (M)
CTLA-4 Orencia fusion
ECD) protein dimer)
Human CTLA-
162 3.95 x 10-9 1.32x
4-IgG2
Orencia fusion
164 5.23 x 10-9 1
protein dimer
LEA29Y-Ig 166 1.05 x l0 -5.23 x 10-1 5x ¨ 10x
58 2.65 x 10-9 ¨ 5.23 x 10-1 2x ¨ 10x
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D1T-IgG2 59 5.23x 104 - 2.62 x 10-1 10x - 20x
D2-IgG2 60 2.62x 10-1 - 1.31 x 10-1 20x - 40x
D3-IgG2 61 <1.31 x 10-1 >40x
D4-IgG2 62 2.65 x 10-9- 5.23 x 1010 2x - 10x
D5-1gG2 63 2.65 x 10-9 - 5.23 x 1040 2x- 10x
D6-IgG2 64 2.65 x 10-9 -5.23 x 10-10 2x - 10x
D20-402 65 2.62 x 1040 - 1.31 x 1040 20x - 40x
D21-IgG2 66 2.62 x 1040 - 1.31 x 1040 20x - 40x
D23-IgG2 67 <1.31 x 1040 >40x
D24-IgG2 68 <1.31 x 10-10 >40x
D26-IgG2 69 <1.31 x 10-1 > 40x
D27-IgG2 70 <1.31 x 104 >40x
D28-IgG2 71 <1.31 x 1040 >40x
D29-IgG2 72 <1.31 x 10-10 >40x
D31-4G2 73 2.62 x 1040 - 1.31 x 1010 20x - 40x
D3-1-I-gG2 1 <1.31 x 1040 >40x
D3-2-IgG2 2 2.62 x 104 - 1.31 x 10-10 20x - 40x
D3-3-IgG2 3 2.62 x 1040 - 1.31 x 1040 20x - 40x
D3-4-4G2 4 <1.31 x 10-10 > 40x
D3-5-IgG2 5 2.62x 104 - 1.31 x 1040 20x - 40x
D3-6-IgG2 6 2.62 x 1040 - 1.31 x 1040 20x - 40x
D3-7-IgG2 7 <1.31 x 10-10 >40x
D3-8-IgG2 8 2.62 x 104 - 1.31 x 104 20x - 40x
D3-9-IgG2 9 <1.31 x 10-10 >40x
D3-11-IgG2 10 <1.31 x 104 >40x
D3-12-IgG2 11 <1.31 x 10-10 >40x
D3-14-IgG2 12 <1.31 x 10-10 >40x
D3-15-4G2 13 <1.31 x 1040 >40x
D3-16-IgG2 14 <1.31 x 104 >40x
D3-17-IgG2 15 <1.31 x 1040 >40x
D3-19-IgG2 16 2.62 x 1040 - 1.31 x 104 20x - 40x
D3-20-IgG2 17 2.62 x 10-1 - 1.31 x 104 20x - 40x
D3-21-IgG2 18 2.62 x 1040 - 1.31 x 10-10 20x - 40x
D3-22-IgG2 19 2.62 x 10-10 - 1.31 x 1040 20x - 40x
D3-23-Ig02 20 2.62 x 104 - 1.31 x 100 20x - 40x
D3-24-462 21 2.62 x 10-10 - 1.31 x 1040 20x - 40x
D3-25-IgG2 22 2.62 x 10b0_ 1.31 x 1040 20x - 40x
'
D3-26-IgG2 23 2.62 x 10-1 - 1.31 x 104 20x - 40x
.
D3-27-IgG2 24 2.62 x 1040 - 1.31 x 10-1 20x - 40x
D3-28-IgG2 25 5.23x 1010 - 2.62 x 1010 10x - 20x
D3-29-IgG2 26 <1.31 x 1040 > 40x
D3-30-IgG2 27 2.62 x 1040 - 1.31 x 100 20x - 40x
D3-31-IgG2 28 <1.31 x 1040 > 40x _
D3-32-IgG2 29 <1.31 x 10-10 >40x
D3-33-402 30 <1.31 x 1040 >40x
D3-34-IgG2 31 2.62 x 10 - 1.31 x 1040 20x - 40x
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D3-39-IgG2 32 5.23 x 10-1 ¨ 2.62 x 10-10 10x ¨ 20x
D3-50-IgG2 33 2.62 x 10-10 ¨ 1.31 x 10-10 20x ¨ 40x
D3-52-IgG2 34 5.23 x 10-1 ¨2.62 x 10-10 10x ¨ 20x
D3-53-IgG2 35 <1.31 x 10-10 >40x
D3-54-IgG2 36 <1.31 x 10-1 >40x
D3-56-IgG2 38 <1.31 x 10-1 >40x
D3-62-IgG2 44 <1.31 x 10-10 >40x
D3-65-IgG2 47 <1.31 x 10-1 >40x
D3-66-IgG2 48 <1.31 x 10-1 >40x
D3-69-IgG2 50 <1.31 x 10-10 >40x
D3-70-IgG2 51 <1.31 x 10-1 > 40x
D3-71-IgG2 52 < 1.31 x 10-1 >40x
D3-72-IgG2 53 <1.31 x 10-10 > 40x
D3-73-IgG2 54 <1.31 x 10-1 >40x
D3-74-IgG2 55 <1.31 x 10-1 > 40x
D3-75-IgG2 56 <1.31 x 10 1 > 40x
D3-76-IgG2 57 <1.31 x 10-1 > 40x
*Note: The sequence identification numbers (SEQ ID NOS) shown in Table 3 for
human CTLA-4-IgG2, Orencia , and LEA29Y-Ig fusion proteins are those of the
polypeptide sequences of these Ig fusion proteins, respectively. The SEQ ID NO
shown in
Table 3 for each mutant CTLA-4-Ig fusion protein identifies the polypeptide
sequence of
the mutant CTLA-4 ECD of the identified mutant CTLA-4-Ig fusion protein. The
data
pertain to a mutant CTLA-4-Ig comprising a mutant CTLA-4 ECD (e.g., any of SEQ
ID
NOS:1-48 and 58-73) fused at its N-terminus to the C-terminus of the IgG2 Fc
polypeptide shown in SEQ ID NO:184 or 218. Methods for making such fusion
proteins
are known in the art and are described herein. However, as noted above, we
have found
experimentally that a mutant CTLA-4-Ig made in CHO cells using a vector
comprising a
nucleotide sequence encoding the predicted hIgG2 Fc polypeptide shown in SEQ
ID
NO:184 does not typically include the predicted C-terminal lysine (K) residue;
thus, the
hgG2 Fc polypeptide sequence of a mutant CTLA-4-IgG2 is that shown in SEQ ID
NO:218, which hIgG2 Fc polypeptide sequence does not include the C-terminal
lysine
residue as compared to the sequence shown in SEQ ID NO:184. Exemplary fusion
protein
sequences which do not include the C-terminal lysine residue are shown in SEQ
ID
NOS:205-214, 219, and 221.
Table 4 presents binding avidities of mutant CTLA-4-Ig fusion proteins to
hCD80-
mIg, as measured by the standard Biacore assay. Specifically, Table 4 shows
the clone
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name of a mutant CTLA-4-Ig fusion protein; the sequence identification number
(SEQ ID
NO) corresponding to the polypeptide sequence of the monomeric mutant CTLA-4
ECD
fusion protein; the equilibrium dissociation constant (KD (Molar (M)) for the
hCD80-mIg
ligand binding avidity assay; and the binding avidity of the mutant CTLA-4-Ie
fusion
protein to the hCD80-mIg ligand relative to the binding avidity of the Orencia
fusion
protein to the same ligand. For each mutant protein, the fold improvement in
binding
avidity to the hCD80-mIg ligand compared to the binding avidity of the Orencia
fusion
protein to the hCD80-mIg ligand is shown (4th column in Table 4). The Orencia
fusion
protein serves as the reference, i.e., with the binding avidity to hCD80-mIg
set to 1. The
mutant CTLA-4-Ig fusion proteins typically exist as dimeric fusion proteins in
solution.
As shown in Table 4, dimeric mutant CTLA-4-Ig fusion proteins of the invention
have
binding avidities to the hCD80-mIg ligand that are: (1) at least about equal
to or greater
than the binding avidity of human CTLA-4-IgG2; (2) at least about equal to or
greater than
the binding avidity of the Orencia fusion protein to the hCD80-mIg ligand;
and/or (3) at
least about equal to or greater than the binding avidity of the LEA29Y-Ig to
the hCD80-
mIg ligand. As discussed above, each dimeric mutant CTLA-4-Ig dimer can be
made by
using methods set forth in Example 3 above.
A number of mutant CTLA-4-Ig fusion proteins were found to have a rate of
dissociation from hCD80-mIg fusion protein that is about equal to or greater
than the rate
of dissociation of the Orencia fusion protein from the same ligand (data not
shown).
Some mutant CTLA-4-Ig fusion proteins were found to have a rate of association
to
hCD80-mIg about equal to or greater than the rate of association of Orencia
fusion
protein to the same ligand (data not shown).
Many mutant CTLA-4-Ig fusion proteins shown in Table 4 had hCD80-mIg
equilibrium dissociation constants (KD) that were lower than the hCD80-mIg
equilibrium
dissociation constant of human CTLA-4-IgG2 or Orencia fusion protein.
Furthermore,
several mutant CTLA-4-Ig fusion proteins shown in Table 4 had hCD80-mIg
equilibrium
dissociation constants that were at least about equal to the hCD80-mIg
equilibrium
constant of LEA29Y-Ig.
Many mutant CTLA-4-Ig fusion proteins shown in Table 4 had binding avidities
for hCD80-mIg that are greater than the binding avidities of human CTLA-4-IgG2
or
Orencia fusion protein for the same ligand (fold improvement in hCD80-mIg
binding
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avidity relative to the Orencia fusion protein is shown the 4th column).
Additionally,
several mutant CTLA-4-Ig fusion proteins shown in Table 4 had binding
avidities for
hCD80-mIg that are at least about equal to the binding avidity of LEA29Y-Ig
for the same
ligand.
A mutant CTLA-4-Ig of the invention that has a higher binding avidity to the
hCD80-mIg than does the hCTLA-4-IgG1, Orencia , or LEA29Y-Ig fusion protein
will
likely have an increased in vivo immunosuppressive potency compared to the
hCTLA-4-
IgG2, Orencia , or LEA29Y-Ig fusion protein, respectively, such as in, e.g.,
therapeutic
and/or prophylactic methods for suppressing an immune response in a subject
(e.g., in the
in vivo treatment of immune system diseases or disorders of mammals, such as
e.g.,
humans, in which immunoinhibition or immunosuppression is desirable), methods
for
inhibiting rejection of a tissue or organ transplant from a donor by a
recipient (e.g., by a
mammal, such as, e.g., a human), and other methods described elsewhere herein.
Table 4.
Binding Avidity
Fusion SEQ ID NO* for hCD80-mIg
Protein (e.g., of mutant hCD80-mIg KD (Relative to
(dimer) CTLA-4 ECD) (M) Orencia fusion
protein dimer)
hCTLA-4-
162 6.55 x 10-1 1.34x
IgG2
Orencia
fusion protein 164 8.77 x 10-1 1
dimer
LEA29Y-Ig 166 4.39x 10-1 - 2.19 x 10-1
2x - 4x
D1-IgG2 58 <4.39 x 1040 > 2x
D1T-IgG2 59 <4.39 x 10-1 > 2x
D2-IgG2 60 <4.39 x 10-1 > 2x
D3-IgG2 61 1.75 x I 0 -4.39 x 10-1
0.5x - 2x
D4-IgG2 62 1.75 x 10-9 -4.39 x 10-1
0.5x - 2x
D5-IgG2 63 1.75x 10-9- 4.39 x 104
0.5x - 2x
D6-IgG2 64 1.75 x 10-9 -4.39 x 104
0.5x - 2x
D20-IgG2 65 1.75 x 10-9 -4.39 x 10-1
0.5x - 2x
D21-I2G2 66 1.75 x 10 -4.39 x 10-1
0.5x - 2x
D23-IgG2 67 <4.39 x 10-1 > 2x
D24-I2G2 68 1.75 x i0 -4.39 x 10-1
0.5x - 2x
D26-IgG2 69 1.75 x 10-9 -4.39 x 10-1
0.5x - 2x
D27-IgG2 70 1.75 x l0 -4.39 4.39 x 10-
10 0.5x - 2x
D28-I2G2 71 1.75 x 10-9- 4.39 x 10-1
0.5x - 2x
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D29-1202 72 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D31-1202 73 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-1-IgG2 1 1.75x 10-9- 4.39 x 10-1 0.5x -
2x
D3-2-IgG2 2 1.75 x 10-9- 4.39 x 10-1 0.5x -
2x
D3-3-IgG2 3 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-4-IgG2 4 1.75x 10-9 - 4.39 x 10-10 0.5x -
2x
D3-5-IgG2 5 1.75 x 10-9 - 4.39 x 10-10 0.5x
- 2x
D3-6-IgG2 6 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-7-IgG2 7 1.75 x 109 -4.39 x 10-1 0.5x -
2x
D3-8-IgG2 8 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-9-IgG2 9 1.75 x 10-9 -4.39 x 1010 0.5x -
2x
D3-11-IgG2 10 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-12-IgG2 11 <4.39 x 10-1 > 2x
D3-14-IgG2 12 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-15-IgG2 13 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-16-IgG2 14 1.75 x 10-9 -4.39 x 104 0.5x -
2x
D3-17-IgG2 15 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-19-IgG2 16 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-20-IgG2 17 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-21-IgG2 18 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-22-IgG2 19 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-23-IgG2 20 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-24-IgG2 21 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-25-IgG2 22 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-26-IgG2 23 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-27-IgG2 24 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-28-IgG2 25 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-29-IgG2 26 1.75 x 10-9 -4.39 x 100 0.5x -
2x
D3-30-402 27 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-31-IgG2 28 < 4.39 x 10-10 >2x
D3-32-IgG2 29 1.75x 10-9 - 4.39 x 10-10 0.5x -
2x
D3-33-IgG2 30 1.75 x 10 -4.39 x 10-1 0.5x -
2x
D3-34-IgG2 31 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-39-1gG2 32 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-50-IgG2 33 1.75 x 10-9 -4.39 x 1040 0.5x -
2x
D3-52-IgG2 34 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-53-IgG2 35 <4.39 x 10-1 > 2x
D3-54-402 36 1.75 x 10-9 -4.39 x 10-10 0.5x -
2x
D3-56-IgG2 38 1.75 x 10-9 -4.39 x 10-1 0.5x -
2x
D3-62-IgG2 44 <4.39 x 10-1 > 2x
D3-65-IgG2 47 <4.39 x 10-1 > 2x
D3-66-402 48 <4.39 x 10-10 > 2x
D3-69-IgG2 50 <4.39 x 10-1 > 2x
D3-70-IgG2 51 <4.39 x 10-1 > 2x
D3-71-IgG2 52 <4.39 x 1040 > 2x
D3-72-IgG2 53 <4.39 x 10-10 > 2x
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D3-73-IgG2 54 <4.39 x 10-I > 2x
D3-74-IgG2 55 <4.39 x 104 > 2x
D3-75-IgG2 56 <4.39 x 10-1 > 2x
D3-76-IgG2 57 1.75 x 10-9 ¨4.39 x 10-1 0.5x - 2x
* Note: The SEQ ID NOS shown in Table 4 for human CTLA-4-IgG2, Orencia ,
and LEA29Y-Ig fusion proteins are those of the polypeptide sequences of these
fusion
proteins, respectively. The SEQ ID NO shown in Table 4 for each mutant CTLA-4-
Ig
fusion protein identifies the polypeptide sequence of the mutant CTLA-4 ECD of
the
identified mutant CTLA-4-Ig fusion protein. The data pertain to a mutant CTLA-
4-Ig
comprising a mutant CTLA-4 ECD (e.g., any of SEQ ID NOS:1-48 and 58-73) fused
at its
N-terminus to the C-terminus of the IgG2 Fc polypeptide shown in SEQ ID NO:184
or
218. However, we have found experimentally by LCMS analysis that a mutant CTLA-
4-
ig made in CHO cells using a vector comprising a nucleotide sequence encoding
the
predicted hIgG2 Fc polypeptide shown in SEQ ID NO:184 does not typically
include the
predicted C-terminal lysine (K) residue; thus, the hIgG2 Fc polypeptide
sequence of a
mutant CTLA-4-IgG2 is that shown in SEQ ID NO:218, which hIgG2 Fc polypeptide
sequence does not typically include the C-terminal lysine residue as compared
to the
sequence shown in SEQ ID NO:184. Exemplary fusion protein sequences that do
not
include the C-terminal lysine residue are shown in SEQ ID NOS:205-214, 219,
and 221.
Monomeric Kinetic Assays.
Further confirmation of binding properties of mutant CTLA-4-Ig fusion proteins
was obtained by monovalent kinetic binding assays. These assays measure the
binding
kinetics of a bivalent test protein (e.g., a dimeric mutant CTLA-4-Ig fusion
protein) coated
to sensor chips and monovalent ligand (papain-digested hCD86-mIg) in the
mobile phase.
Goat anti-human IgG antibody (Jackson ImmunoResearch, #109-005-098) was
coupled to
CM5 sensor chips according to the manufacturer's protocols, typically yielding
15,000
response units (RU). Ligand was captured by incubation of antibody-coated
sensor chips
with 10 tl of a 2 ig/m1 solution of dimeric mutant CTLA-4-Ig fusion proteins
in HBS-EP
buffer at a flow rate of 10 [il/min. Ligand capture levels were typically 25-
80 RU.
Monomeric hCD86-mIg ligands (created by papain digestion and protein-A
sepharose
adsorption of hCD86-mIg, as described in Hermanson, G.T. BIOCONJUGATE
TECHNIQUES,
Academic Press, 1996) were diluted in HBS-EP buffer and flowed through test
protein-
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coated sensor chips for 2 min at 30 pl/min, followed by 2 min incubation with
HBS-EP
buffer containing no protein at the same flow rate. Regeneration between
cycles was
performed by 3 min incubation with 10 mM glycine buffer (pH 1.7) at 30111/min.
Typically. 8 dilutions of monomeric analyte proteins ranging from 3000 nM to
0.2 nM
were analyzed against a blank reference (HBS-EP buffer alone) in duplicate.
Rmax signal
levels for binding to mutant CTLA-4-Ig proteins ranged from 10-60 RU.
For kinetic analysis, data from monomeric binding assays were selected as
described above except that association data selection began and ended 5 s
from the
injection start and stop times, and dissociation data selection started 5 s
after the injection
stop time, and typically included 1-60 s of the dissociation period. Such data
were also
analyzed for steady state equilibrium affinities using the BIAevaluation
software. Steady
state binding levels for each concentration (Responseeq ("Req") values) were
averaged
over 5-20 s range near the end of the sample injection using the BIAevaluation
"General
fit: average" function. Steady state affinity was determined from the Req vs.
concentration plot using the BIAevaluation software according to the formula
Req=KA x C
x Rmax/(KA x C x n+1), where C is the analyte concentration and n, the steric
interference
factor, is 1, and KD= 1/ KA. In some cases, substantial non-specific binding,
represented
by a residual flat R-value trace after dissociation, was observed. Such data
were corrected
by subtracting the residual R-values from the Req values. The Kro was then
calculated in
GraphPad Prism software (GraphPad Software, Inc.) using the "one site-specific
binding"
model.
This monomeric binding assay was performed on a subset of representative
mutant
CTLA-4-Ig proteins and the results are summarized in Table 5. Overall, the
degree of
improvement in hCD86 ECD binding to mutant CTLA-4-Ig fusion proteins relative
to
LEA29Y-Ig observed in the monomeric binding assays was similar to that
observed for
hCD86-mIg binding to mutant CTLA-4-Ig fusion proteins relative to LEA29Y-Ig in
the
standard kinetic assays. Such results support the conclusion that the observed
improvements in binding kinetics for the mutant proteins are due to real
improvements in
binding affinities of the mutant proteins (e.g., compared to Orencia and/or
LEA29Y-Ig
fusion proteins) and are not due to potential artifacts caused by higher
valency of
aggregated protein preparations.
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Table 5.
Binding Affinity
Fusion Protein SEQ ID NO Monomeric hCD86 ECD for Monomeric
(dimer) (e.g., of mutant KD (M) hCD86 ECD
CTLA-4 ECD) (Relative to
LEA29Y-Ig)
LEA29Y-Ig 166 1.68 x 10-6 1
D3-IgG2 61 <3.36 x 104 >5x
D3-4-IgG2 4 <3.36 x 10-7 >5x
D3-11-IgG2 10 <3.36 x 10-7 >5x
D3-12-IgG2 11 <3.36 x 10-7 >5x
D3-14-IgG2 12 <3.36 x 10-7 >5x
D3-17-IgG2 15 <3.36 x 10-7 >5x
D3-20-IgG2 17 8.4 x 10-7- 3.36 x 10-7 2x-5x
D3-27-IgG2 24 8.4 x 10-7- 3.36 x 10-7 2x-5x
D3-29-IgG2 26 <3.36 x 10-7 >5x
D3-31-IgG2 28 <3.36 x 10-7 >5x
D3-53-IgG2 35 <3.36 x 10-7 >5x
*Note: The SEQ ID NO shown in Table 5 for LEA29Y-Ig is that of the
polypeptide sequence of the LEA29Y-Ig fusion protein. The SEQ ID NO shown in
Table
5 for each mutant CTLA-4-Ig fusion protein identifies the polypeptide sequence
of the
mutant CTLA-4 ECD present in the identified mutant CTLA-4-Ig fusion protein.
The data
pertain to a mutant CTLA-4-Ig comprising a mutant CTLA-4 ECD (e.g., any of SEQ
ID
NOS:4, 10-12, 15, 17, 24, 26, 28, 35, and 61) fused at its N-terminus to the C-
terminus of
the IgG2 Fc polypeptide shown in SEQ ID NO:184 or 218. However, we have found
experimentally by LCMS analysis that a mutant CTLA-4-Ig made in CHO cells
using a
vector comprising a nucleotide sequence encoding the predicted hIgG2 Fc
polypeptide
shown in SEQ ID NO:184 does not typically include the predicted C-terminal
lysine (K)
residue; thus, the hIgG2 Fc polypeptide sequence of a mutant CTLA-4-IgG2 is
that shown
in SEQ ID NO:208, which hIgG2 Fc polypeptide sequence does not typically
include the
C-terminal lysine residue as compared to the sequence shown in SEQ ID NO:184.
Exemplary fusion protein sequences that do not include the C-terminal lysine
residue are
shown in SEQ ID NOS:205-214, 219, and 221. Exemplary fusion protein sequences
that
include the C-terminal lysine residue are shown in SEQ ID NOS:74-79, 197-200,
220, and
222.
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EXAMPLE 5
Measuring Biological Activity of CTLA-4 Mutants using Human PBMC Proliferation
Assays (Anti-CD3 Antibody Stimulation).
CTLA-4-Ig and particular variants thereof have been shown to be potent
inhibitors
of T cell proliferation in vitro (see, e.g., Larson et al., Am. J. Transplant.
5, 443). To
measure improved activity of mutant CTLA-4-Ig proteins in such assays, a
peripheral
blood mononuclear cell (PBMC) proliferation assay was developed.
Human blood (freshly collected from a donor program) was diluted with an equal
volume of PBS and fractionated to isolate PBMCs using a Histopaque (Sigma,
#10771)
Fico11 gradient as per the manufacturer's recommended conditions. PBMCs were
diluted
in Growth Medium (DMEM/F12 medium (Invitrogen, #10565-018) supplemented with
10% FBS (Hyclone #SV30014.03) and lx PSG (Invitrogen, #10378-016) and added to
96-
well culture plates (BD Biosciences, #353077) at a density of 1 x 105
cells/well. Test
compounds were serially diluted in Growth Medium and added to wells in
triplicate. Cell
proliferation was initiated by addition of mouse anti-human CD3 antibody (BD
Pharmingen: 555329) to a final concentration of 5 lig/ml. After incubation at
37 C for 2
days (d), 3H thymidine (GE Healthcare, #IRK758- 5 MCI) was added at 1
p.Ci/well and
plates were incubated at 37 C for an additional 16 hr. Cells were harvested
with a cell
harvester (FilterMate Omnifilter-96 Harvester) using the manufacturer's
recommended
conditions and measured for 3H thymidine incorporation using a scintillation
counter
(Wallac Trilux, #1450-421). The degree of 3H thymidine incorporation (3H
thymidine
uptake) is indicative of the degree of T cell proliferation. 3H-thymidine
incorporation is
measured by standard techniques. Proliferation of T cells is expressed as the
mean counts
per minute (cpm) of triplicate wells.
Cell proliferation data was analyzed with GraphPad Prism 5 software using a
non-
linear regression curve fit model (sigmoidal dose-response, variable slope)
and the least
squares fit method. The IC50 (also shown as IC50) parameters and their
associated 95%
confidence intervals from the results are reported (Table 6). Figure 6 shows
cell
proliferation curves from a representative PBMC proliferation assay (using
anti-CD3
antibody stimulation) involving a set of exemplary mutant CTLA-4-Ig fusion
proteins of
the invention ¨ i.e., D3-04-IgG2, D3-11-IgG2, D3-12-IgG2, and D3-14-IgG2
fusion
proteins. The graph is a plot of 3H thymidine incorporation (counts per minute
(cpm))
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versus protein concentration (nanoMolar (nM)). 3H thymidine incorporation (3H
thymidine
uptake), which is indicative of the degree of cell proliferation, is measured
by standard
techniques.
The Orencia and LEA29Y-Ig fusion proteins were included as controls for
comparison. These results demonstrate that mutant CTLA-4-Ig Ig fusion proteins
of the
invention have significantly higher potency or greater ability than the
Orencia and/or
LEA29Y-Ig fusion protein(s) in inhibiting or suppressing polyclonal T cell
activation or T
cell proliferation in vitro.
The PBMC proliferation assay was performed using other mutant CTLA-4-Ig
fusion proteins of the invention. Table 6 provides a summary of the data for a
representative set of mutant CTLA-4-Ig fusion proteins of the invention. Table
6 presents
comparisons of mean IC50 values (nanomolar (nM)) for exemplary mutant CTLA-4-
Ig
fusion proteins versus controls (Orencia , hCTLA-4-IgG2, and LEA29Y-Ig fusion
proteins) in the PBMC proliferation assay (with anti-CD3 antibody
stimulation). An IC50
value represents the concentration of a compound (e.g., mutant CTLA-4-Ig,
hCTLA-4-
IgG2, Orencia , or LEA29Y-Ig fusion protein) that is required for 50%
inhibition of T
cell proliferation in vitro. IC50 values from individual experiments were
averaged to
provide mean IC50 values, which were used for statistical analyses. A one-way
ANOVA
with post hoc Dunnett or Bonferroni test was used to compare mutant CLTA-4-Ig
fusion
proteins and hCTLA-4-IgG2 to the Orencia or LEA29Y-Ig fusion protein,
respectively
(C.W. Dunnett, New Tables for Multiple Comparisons with a Control, Biometrics
20(3):482-491 (Sept. 1964); Abdi, Herve, "The Bonferroni and Sidak corrections
for
multiple comparisons", in ENCYCLOPEDIA OF MEASUREMENT AND STATISTICS (N.J.
Salkind ed., Thousand Oaks, CA 2007); also available on the worldwide web at
the web
address utdallas.edu/¨herve/Abdi-Bonferroni2007-pretty.pdf.). Statistical
analysis of Ig
fusion protein composed of one of the following mutant CTLA-4 ECD polypeptides
¨
clones D24, D3-07, D3-15 and D3-16 ¨ was not performed as n = 1. The term "SD
(mean
log IC50)" represents the standard deviation in mean log IC50 values.
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Table 6. Summary of Data From Exemplary PBMC Proliferation Assays Using
Anti-CD3 Antibody Stimulation
Fusion Protein Mean IC50 Mean Log 1050 SD (Mean Log
(dimer) (nM) (nM) IC50) (nM)
Orencia fusion 5.16 0.71 0.51
protein dimer
hCTLA-4-IgG2 8.46 0.93 0.43
LEA29Y-Ig 0.481 -0.32 0.54
D3-4-IgG2 0.0512 -1 .27 0.45
D3-7-IgG2 0.12 -0.93 NA
D3-11-IgG2 0.0812 -1.07 0.40
D3-12-IgG2 0.061'2 -1.27 0.17
D3-14-IgG2 0.0712 -1.17 0.15
. D3-15-IgG2 0.21 -0.69 NA
D3-17-IgG2 0.0412 -1.36 0.37
D3-20-IgG2 0.071'2 -1.19 0.37
D3-26-IgG2 0.151 -0.83 0.49
D3-27-IgG2 0.1012 -1.00 0.41
D3-29-IgG2 0.071.2 -1.13 0.53
D3-30-IgG2 0.181 -0.74 0.35
D3-31-IgG2 0.0412 -1.42 0.25
D3-32-IgG2 0.101 -1.00 0.47
D3-33-IgG2 0.121 -0.94 0.69
D3-34-IgG2 0.411 -0.39 0.18
D3-39-IgG2 0.471 -0.33 0.21
D3-50-IgG2 0.351 -0.46 0.23
D3-52-IgG2 0.491 -0.31 0.20
D3-53-IgG2 0.0212 -1.69 0.24
D3-54-IgG2 0.171 -0.77 0.22
D3-56-IgG2 0.08' -1.08 0.20
D3-62-IgG2 0.0512 -1.29 0.23
D3-69-IgG2 0.051'2 -1.34 0.19
D3-70-IgG2 0.081 -1.10 0.10
D3-71-IgG2 0.05 -1.32 NA
D3-72-IgG2 0.0312 -1.54 0.19
D3-73-IgG2 0.231 -0.64 0.25
D3-75-IgG2 0.081 -1.11 0.33
D3-76-IgG2 0.131 -0.88 0.36
D3-IgG2 0.141 -0.85 0.13
D24-IgG2 0.12 -0.93 NA
The superscripts shown in Table 6 are as follows: 'Statistically different to
Orencia with p<0.05, as determined by 1 way ANOVA with post hoc Dunnett
test.
2Statistically different to LEA with p<0.05, as determined by 1 way ANOVA post
hoc
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Bonferroni test. The fusion proteins comprising D3-7, D3-15, D3-71 and D24
mutant
CTLA-4 ECDs were tested once and therefore no statistical comparison could be
performed. Note: The term "NA" in Table 6 means "not available".
Statistical analysis revealed that all of the mutant CTLA-4-Ig fusion proteins
that
were tested in at least two separate assays and are designated with the
superscript (1) (see
Table 6) were statistically superior in potency to the Orencia and hCTLA-4-
IgG2 fusion
proteins (p < 0.05) (i.e., have a greater ability to suppress or inhibit T
cell proliferation in
in vitro PBMC assays than the Orencia and hCTLA-4-IgG2 fusion proteins).
Those
designated with the superscript (2) (see Table 6) were also statistically
superior in potency
to the LEA29Y-Ig fusion protein (p < 0.05) (i.e., have a greater ability to
suppress or
inhibit T cell proliferation in in vitro PBMC assays than the LEA29Y-Ig fusion
protein),
as determined by one-way ANOVA with post hoc Dunnett and Bonferroni tests
discussed
supra. There was no statistical difference between human CTLA-4 fusion
proteins
comprising either the modified IgG1 Fe (as in Orencia ) or the wild-type IgG2
Fe (as in
hCTLA4-IgG2). This finding implies that the differences in functional
activities shown in
Table 6 between the mutant CTLA-4-Ig fusion proteins of the invention (which
each
comprise a human IgG2 Fe) and either Orencia or hCTLA4-IgG2 were as a direct
consequence of amino acid changes (i.e., amino acid substitutions) made in the
CTLA-4
ECD region. The differences in functional activities between these mutant CTLA-
4-Ig
fusion proteins of the invention and, for example, Orencia (which comprises a
modified
IgG1 Fe) were not due to differences in their respective Ig Fe polypeptide
sequences.
It is believed that given the increased abilities of mutant CTLA-4-Ig fusion
proteins of the invention to suppress or inhibit T cell proliferation in in
vitro assays as
compared to Orencia , LEA29Y-Ig, and/or hCTLA-4-IgG2 fusion proteins, such
mutant
proteins should also exhibit increased immunosuppressive potencies in in vivo
therapeutic
and/prophylactic methods as compared to Orencia , LEA29Y-Ig, and/or hCTLA-4-
IgG2
fusion proteins. Each such mutant CTLA-4-Ig fusion protein of the invention is
believed
to have a greater ability to suppress or inhibit T cell proliferation in in
vivo methods or
applications relative to Orencia , LEA29Y-Ig, and/or hCTLA-4-IgG2 fusion
proteins,
such as in, e.g., therapeutic and/or prophylactic methods for suppressing or
inhibiting an
immune response in a subject (e.g., in the in vivo treatment of immune system
diseases or
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disorders in a mammal, such as e.g., a human), methods for suppressing or
inhibiting
rejection of a tissue or organ transplant from a donor by a recipient (e.g.,
by a mammal,
such as e.g., a human), and/or other treatment or diagnostic methods described
elsewhere
herein.
Applying the same statistical analyses, we found no statistical difference
between
the Orencia fusion protein (comprising human CTLA-4 ECD-mutant IgGl) and
human
CTLA-4-IgG2. Thus, it is believed that the differences in the Ig domains of
these
molecules (i.e., the mutant IgG1 of the Orencia fusion protein and the human
IgG2 of
hCTLA-4-IgG2) did not affect the functionality of these molecules. See Figure
11. The
inhibition of proliferation observed with increasing doses of the Orencia
fusion protein
was not significantly different from that observed with CTLA-4-IgG2,
indicating that their
respective immunosuppressive activities are not biased according to their
different IgG
isotypes, but rather result from their hCTLA-4 ECD polypeptides. Thus, the
different
immunosuppressive activities between mutant CTLA-4-Ig polypeptides of the
invention
and Orencia fusion protein (or LEA29Y-Ig, since it contains the same Ig as in
the
Orencia protein) cannot be attributed to their respective Fc regions
comprising different
IRG isotypes.
The invention includes monomeric mutant CTLA-4 ECD proteins that have an
ability and, in some instances, a greater ability to suppress or inhibit T
cell activation or
proliferation than a monomeric human CTLA-4 protein or an extracellular domain
thereof.
Also provided are monomeric mutant CTLA-4 ECD fusion proteins that have an
ability
and, in some instances, a greater ability to suppress or inhibit T cell
activation or
proliferation than a monomeric hCTLA-4 Ig fusion protein or an extracellular
domain
thereof. Also included are mutant CTLA-4 ECD protein dimers that have an
ability and,
in some instances, a greater ability to suppress or inhibit T cell activation
or proliferation
than a dimer comprising two human CTLA-4 extracellular domains. Some mutant
CTLA-
4 ECD fusion protein dimers of the invention (e.g., mutant CTLA-4-ECD-Ig
fusion
protein dimers) have an ability and, in some instances, a greater ability to
suppress or
inhibit T cell activation or proliferation than a hCTLA-4-IgG2 fusion protein
dimer,
Orencia fusion protein dimer, and/or LEA29YIg fusion protein dimer.
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EXAMPLE 6
Measuring Biological Activity of Mutant CTLA-4-Ig Molecules Using Human CD4+ T
Cell Proliferation Assays.
Human CTLA-4-Ig and particular variants thereof have been shown to inhibit T
cell proliferation by blocking signaling of CD80 and CD86 though CD28 (Linsley
P.S.,
Immunity 1:793-801 (1994); Larson C. P. et al., Am. J. Transplant. 5:443-453
(2005)).
Because the mutant CTLA-4-Ig proteins of the invention are improved in binding
avidity
for the CD86-Ig ligand, a CD4+ T cell proliferation assay was developed to
measure
activity of the mutant CTLA-4-Ig proteins in blocking signaling through CD86.
Creation of DNA Sequence Encoding a Full-length Human CD86 Protein.
Plasmid pCDNA3.1 hB7.2 FL was created to encode the full-length human CD86
protein for expression on the surface of transfected cells. DNA encoding human
CD86
was generated by PCR amplification of cDNA derived from human leukocytes (BD
Biosciences, Cat# HL4050AH) using forward and reverse oligonucleotide primers
designed based on sequence homology to the CD86-encoding nucleotide sequence
set
forth in SEQ ID NO:176. The primers were designed, made, and assembled using
standard techniques well known by those of ordinary skill in the art and
included stop and
start codons and restriction sites as necessary. The PCR amplification
procedures
employed are also well known in the art. Such techniques are described in,
e.g., Berger,
Ausubel, and Sambrook, all supra. 50 nanogram (ng) cDNA was used as template
in a
100111 PCR reaction with 1 04 forward and reverse primers, Herculase
Polymerase buffer
(Stratagene; #600260) and 2001.11\4 dNTPs for 30 amplification cycles (94 C,
30 s; 50 C,
s; 72 C, 60 s). The PCR product was purified by QiaQuick PCR Spin Columns
25 (Qiagen #28106) and digested with restriction enzymes Kpnl and Nod.
Fragments were
separated by agarose-gel electrophoresis, purified using Qiaquick Gel
Extraction Kit
(Qiagen, #28704) as per manufacturer's recommendation, and ligated into
similarly
digested plasmid pCDNA 3.1(+) (Invitrogen, Cat. #V790-20). Ligations were
transformed
into TOP10 E. coli cells (Qiagen, Cat. #C4040-10) as per manufacturer's
30 recommendations. Transformed cells were incubated in LB (Luria broth
media)
containing 50 ug/m1 carbenicillin at 250 rpm overnight at 37 C and then used
to make a
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maxiprep (Qiagen; #12362) stock of plasmid DNA as per the manufacturer's
recommended conditions.
The predicted amino acid sequence of the full-length human CD86 protein is
shown in SEQ ID NO:175. In this sequence, amino acid residues 1-23 comprise
the
predicted signal sequence, amino acid residues 24-241 comprise the human CD86
extracellular domain, amino acid residues 242-270 comprise the transmembrane
domain,
and amino acid residues 271-329 comprise the cytoplasmic domain.
Creation of Stable Cell Lines Expressing Human CD86 on the Cell Surface.
HEK293 cells were grown to 80-90% confluence in T-75 flasks containing 20 ml
Growth Medium (DMEM/F12 medium (Invitrogen, Cat. #10565-018) supplemented with
10% FBS (Hyclone Cat.#5V30014.03) and lx PSG (Invitrogen, Cat. #10378-016)).
Cells were transfected with 10 lig plasmid DNA (pCDNA3.1 hB7.2 FL) mixed with
60 IA
Fugene 6 (ROCHE, #11814443001) as per the manufacturer's recommended
conditions.
Cells were incubated for 2 days (d) at 37 C in Growth Medium and further
incubated for
10 d at 37 C in Selection Medium (Growth Medium containing 300 tig/m1Geneticin
(Invitrogen, #1013]-027), changing the media every 2 d. To enable FACS
sorting,
transfected cells were stained with FITC-labeled anti-CD86 antibody (BD
Biosciences,
#555) as per the manufacturer's recommend conditions. Using a cell-sorter
(Dako,
MoFlo) gated for FITC signal, CD86-positive cells were individually sorted
into 96-well
culture plates (Sigma-Aldrich, #CLS-3596) containing 200111/well Growth Medium
containing 25% Conditioned Medium (Growth Medium previously harvested from
untransfected (or naive) cell cultures). After incubation at 37 C for 13-19 d,
cells were
dispersed by trypsin hydrolysis and transferred to 24-well culture plates
containing 0.5
ml/well of Growth Medium. After incubation at 37 C for 7 d, cells were
dispersed by
trypsin hydrolysis and transferred to T-75 flasks containing 20 ml Growth
Medium.
Final cell lines were selected based upon high levels of cell-surface CD86
expression as
measured by FACS analysis of FITC-labeled anti-CD86 antibody stained cells
using
FACS Caliber (BD Biosciences), as per the manufacturer's recommended
conditions.
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CD4+ T cell Proliferation Assays.
CD4+ T cells were enriched to >96% from human Buffy coat preps (Stanford
University Blood Center, Stanford, CA) using the EasySep Human CD4 Positive
Selection Kit (StemCell Technologies, #18052R) with a magnetic cell separator
(RoboSep, StemCell Technologies, #20000) following manufacturer's
recommendations.
Enriched CD4+ T cells were adjusted to a density of 1 x 106 cells/m1 in
Yssel's media
(Gemini Bio-Products, #400-102) supplemented with 10% FBS (Hyclone S
V30014.03)
and added to 96 well tissue culture plates at 50 pi/well. HEK293 cells
expressing
membrane-bound human CD86 were irradiated at 6000 rads (Stanford Research
Institute,
Menlo Park, CA), adjusted to 1 x 106 cells/ml in the same medium and added to
the
culture plates at 50 pi/well. Test compounds were serially diluted in the same
medium
and added to wells in triplicate. Cell proliferation was initiated by addition
of mouse
anti-human CD3 antibody (BD Pharmingen: 555329) to a final concentration of 5
p.g/ml.
After incubation at 37 C for 3 d, 3H thymidine (GE Healthcare, #TRK758-5MCI)
was
added at 1 uCi/well and plates were incubated at 37 C for an additional 18 hr.
Cells were
harvested using a cell harvester (Perkin Elmer Filter Harvester D961962) and
3H
thymidine was measured using a liquid scintillation counter (Wallac Trilux
1450) as per
the manufacturer's recommended conditions. Cell proliferation data were
analyzed with
GraphPad Prism 5 software using a variable slope equation (Y=Bottom + (Top-
Bottom)/(1+10^((LogIC50-X)(HillSlope))) to generate an IC50 for each test
compound.
The term "(LogIC50-X)(HillSlope)" is an exponent in the equation.
Figure 7 shows cell proliferation curves from representative CD4+ T cell
proliferation assays involving an exemplary set of mutant CTLA-4-Ig fusion
proteins of
the invention ¨ i.e., D3-04-IgG2, D3-11-IgG2, D3-12-IgG2, and D3-14-IgG2.
Orencia
and LEA29Y-Ig fusion proteins were included as controls for comparison. The
graph is a
plot of 3H thymidine incorporation (cpm) versus concentration (nM) of protein.
3H
thymidine incorporation is indicative of the degree of cell proliferation and
is measured by
standard techniques. These results demonstrate that mutant CTLA-4-Ig fusion
proteins of
the invention have significantly higher potency or greater ability than the
Orencia and/or
LEA29Y-Ig fusion proteins in inhibiting or suppressing CD86 co-stimulation in
vitro.
This CD4+ T cell proliferation assay was performed on a number of other mutant
CTLA-4-Ig fusion proteins of the invention. Table 7 provides a summary of the
data for a
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set of exemplary mutant CTLA-4-Ig fusion proteins of the invention. Table 7
presents
comparisons of mean IC50 values (nanomolar (nM)) for exemplary mutant CTLA-4-
Ig
fusion proteins versus reference controls (Orencia , LEA29Y-Ig, and human CTLA-
4-
IgG2 fusion proteins) using the CD4+ T cell proliferation assay. IC5Os from
individual
experiments were averaged to provide mean IC50 values, which were used for
statistical
analyses. The term "SD (mean log IC50)" represents the standard deviation in
mean log
IC50 values.
Table 7. Summary of Data From Exemplary CD4+ T Cell Proliferation Assays
Fusion Protein Mean IC50 (nM) Mean Log IC50 SD (Mean Log
(dimer) (nM) IC50) (nM) _
Orencia fusion 1.56 0.19 0.22
protein dimer
hCTLA-4-IgG2 2.24 0.35 0.28 ,
LEA29Y-Ig 0.211 -0.67 0.25
D3-02-IgG2 0.03 -1.56 NA
D3-03-IgG2 0.0412 -1.40 0.11
D3-04-IgG2 0.0312 -1.47 0.02
D3-06-IgG2 0.051 -1.32 0.03 _
D3-11-IgG2 0.0312 -1.52 0.07
D3-12-IgG2 0.041'2 -1.45 0.09
D3-14-IgG2 0.0412 -1.37 0.11
D3-15-1g02 0.021'2 -1.62 0.08
D3-17-IgG2 0.031'2 -1.47 0.11
D3-20-IgG2 0.0412 -1.40 0.11
D3-27-IgG2 0.0412 -1.37 0.10
D3-29-IgG2 0.04 " -1.36 0.13
D3-31-IgG2 0.0312 -1.58 0.21
D3-34-IgG2 0.051'2 -1.28 0.13 _
D3-39-IgG2 0.0512 -1.35 0.10 _
D3-50-IgG2 0.061'2 -1.23 0.24
D3-52-IgG2 0.071,2 -1.14 0.24
D3-53-IgG2 0.021'2 -1.70 0.25
D3-54-IgG2 0.0412 -1.40 0.12
D3-56-IgG2 0.041'2 -1.41 0.07
D3-62-IgG2 0.0412 -1.44 0.09
D3-65-IgG2 0.0612 -1.26 0.14
D3-69-IgG2 0.0312 -1.59 0.14
D3-70-IgG2 0.0512 -1.30 0.06
D3-71-IgG2 0.0412 -1.43 0.09
D3-72-IgG2 0.0312 -1.48 0.05
D3-73-IgG2 0.0612 -1.26 0.18
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D3-75-IgG2 0.03]2 -1.51 0.12
D2-IgG2 0.03" -1.52 0.18
D3-IgG2 0.0412 -1.45 0.17
The superscripts shown in Table 7 are as follows: 'Statistically different to
Orencia with p<0.05, as determined by 1 way ANOVA with post hoc Dunnett test.
Statistically different to LEA with p<0.05, as determined by 1 way ANOVA post
hoc
Bonferroni test. The fusion protein comprising the D3-02 mutant CTLA-4 ECD was
tested once and therefore no statistical comparison could be performed.
Statistical analysis revealed that all of the mutant CTLA-4-Ig fusion proteins
that
were tested in at least two separate assays and are designated with the
superscript (1) (see
Table 7) were statistically superior in potency to the Orencia and hCTLA-4-
IgG2 fusion
proteins (p < 0.05) (i.e., have a greater ability to suppress or inhibit T
cell proliferation in
in vitro CD4+ T cell assays than the Orencia and hCTLA-4-IgG2 fusion
proteins).
Those designated with the superscript (2) (see Table 7) were also
statistically superior in
potency to the LEA29Y-Ig fusion protein (p <0.05) (i.e., have a greater
ability to suppress
or inhibit T cell proliferation in in vitro CD4+ T cell assays than the LEA29Y-
Ig fusion
protein), as determined by one-way ANOVA with post hoc Dunnett and BonfeiToni
tests
discussed supra. There was no statistical difference between human CTLA-4
fusion
proteins comprising either the modified IgG1 Fc (as in Orencia ) or the wild-
type IgG2
Fc (as in hCTLA4-IgG2). This finding implies that the differences in
functional activities
shown in Table 7 between the mutant CTLA-4-Ig fusion proteins of the invention
(which
each comprise a human IgG2 Fc) and either Orencia or hCTLA4-IgG2 were as a
direct
consequence of amino acid changes (i.e., amino acid substitutions) made in the
CTLA-4
ECD region. The differences in functional activities between these mutant CTLA-
4-Ig
fusion proteins of the invention and, for example, Orencia (which comprises a
modified
IgG1 Fc) were not due to differences in their respective Ig Fc polypeptide
sequences.
It is believed that given the increased abilities of mutant CTLA-4-Ig proteins
of the
invention to suppress or inhibit CD86-mediated co-stimulation of T cells
(e.g., human T
cells) in in vitro assays as compared to Orencia , LEA29Y-Ig, and/or hCTLA-4-
IgG2
fusion proteins, such mutant proteins should also exhibit increased
immunosuppressive
potencies in in vivo therapeutic and/prophylactic methods or applications as
compared to
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Orencia , LEA29Y-Ig, and/or human CTLA-4-Ig fusion proteins (e.g., human CTLA-
4-
IgG2 ("hCTLA-4-IgG2")), respectively. In one aspect, mutant CTLA-4-Ig fusion
proteins
of the invention are believed to have a greater ability to suppress or inhibit
CD86-
mediated co-stimulation of T cells (e.g., human T cells) in in vivo methods or
applications
compared to Orencia , LEA29Y-Ig, and/or human CTLA-4-Ig (e.g., hCTLA-4-IgG2)
fusion proteins, respectively, such as in, e.g., therapeutic and/or
prophylactic methods for
suppressing or inhibiting an immune response in a subject (e.g., in the in
vivo treatment of
immune system diseases or disorders in e.g., a mammal, such as, e.g., a
human), methods
for suppressing or inhibiting rejection of a tissue or organ transplant from a
donor by a
recipient (e.g., by a mammal, such as, e.g., a human), and/or other treatment
or diagnostic
methods described elsewhere herein.
EXAMPLE 7
Measuring Biological Activity of Mutant CTLA-4-Ig Molecules Using Human PBMC
Proliferation Assays (Recall Antigen Stimulation).
The activation of memory T cells is an important aspect of autoimmunity
(Rogers
N.J., et al. Eur. J. Immunol 35:2909-2919 (2005)). To measure immunosuppres
sive
activity of mutant CTLA-4-Ig proteins in this respect, a peripheral blood
mononuclear cell
(PBMC) proliferation assay was developed using PPD antigen stimulation.
Human blood (freshly collected from a donor program) was diluted with an equal
volume of PBS and fractionated to isolate PBMCs using a Histopaque (Sigma,
#10771)
Ficoll gradient as per the manufacturer's recommended conditions. PBMCs were
diluted
in RPMI medium (Sigma, #R8758) supplemented with 10% FBS (Hyclone #
SV30014.03)
and lx PSG (penicillin, streptomycin and glutamine) (Invitrogen, #10378-016)
and added
to 96-well culture plates (BD Biosciences, #353077) at a density of 1 x 105
cells/well.
Test compounds were serially diluted in the same medium and added to wells in
quadruplicate. Cell proliferation was initiated by addition of PPD antigen
(purified protein
derivative from Mycobacterium tuberculosis, Mycos, #P-1000-001) to a final
concentration of 5 tg/ml. After incubation at 37 C for 5 d, 3H thymidine (GE
Healthcare,
CR1058-51\40) was added at 1 pEi/well and plates were incubated at 37 C for an
additional 18 hr. Cells were harvested with a cell harvester (FilterMate
Omnifilter-96
Harvester, Perkin Elmer) using the manufacturer's recommended conditions and
measured
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for 3H thymidine incorporation using a scintillation counter (Wallac Trilux,
#1450-421).
Cell proliferation data was analyzed with GraphPad Prism 5 software using a
non-linear
regression curve fit model (sigmoidal dose-response, variable slope) and the
least squares
fit method. The IC50 (or "IC50") parameters and their associated 95%
confidence
intervals are reported.
Figure 8 shows cell proliferation curves from representative PBMC
proliferation
assays involving a set of exemplary mutant CTLA-4-Ig fusion proteins of the
invention ¨
i.e., D3-IgG2, D3-12-IgG2, D3-17-IgG2, and D3-29-402 fusion proteins. Orencia
and
LEA29Y-Ig fusion proteins were included as controls for comparison. The graph
is a plot
of 3H thymidine incorporation (cpm) versus protein concentration (nM). 3H
thymidine
incorporation, which is indicative of the degree of cell proliferation, is
measured by
standard techniques. These results demonstrate that, in one aspect, mutant
CTLA-4-Ig
fusion proteins of the invention have significantly higher potency than
Orencia and/or
LEA29Y-Ig proteins in inhibiting or suppressing memory T cell proliferation in
vitro (e.g.,
mutant CTLA-4-Ig proteins have a greater ability than Orencia and/or LEA29Y-
Ig
proteins in inhibiting or suppressing memory T cell proliferation in vitro in
human PBMC
proliferation assays (recall antigen stimulation)).
This PBMC proliferation assay with PPD antigen stimulation was performed on a
number of other mutant CTLA-4-Ig fusion proteins of the invention. Table 8
provides a
summary of the data for a set of exemplary mutant CTLA-4-Ig fusion proteins of
the
invention. Table 8 presents comparisons of mean IC50 values (nanomolar (nM))
for
exemplary mutant CTLA-4-Ig fusion proteins versus reference controls (Orencia
and
LEA29Y-Ig fusion proteins) using the PBMC proliferation assay with recall
antigen
stimulation. 1050 values from individual experiments were averaged to provide
mean
IC50 values, which were used for statistical analyses. The term "SD (mean log
IC50)"
represents the standard deviation in mean log IC50 values.
Table 8. Summary of Data From Exemplary PBMC Proliferation Assays Using
PPD Antigen Stimulation
Fusion Protein Mean 1050 Mean Loa 1050 SD (Mean Log
(di mer) (nM) (nM) IC50) (nM)
Orencia fusion 5.92 0.67 0.37
protein dimer
LEA29Y-Ig 0.31 -0.71 0.53
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D3-IgG2 0.03 -1.49 NA
D3-12-IgG2 0.06 -1.27 0.17
D3-14-IgG2 0.07 -1.17 0.15
D3-17-IgG2 0.07 -1.24 0.25
D3-20-IgG2 0.13 -0.91 0.18
D3-27-IgG2 0.17 -0.84 0.30
D3-29-1g02 0.07 -1.16 0.18
D3-34-IgG2 0.51 -0.29 NA
D3-50-IgG2 0.28 -0.55 NA
D3-53-IgG2 0.05 -1.29 NA
D3-54-IgG2 0.01 -2.00 NA
D3-56-IgG2 0.01 -1.92 NA
D3-69-IgG2 0.01 -2.00 NA
D3-71-IgG2 0.01 -1.87 NA
D3-75-IgG2 0.01 -2.02 NA
D3-76-IgG2 0.01 -1.89 NA
Note: The term "NA" in Table 8 means "not available".
Statistical analyses revealed that all mutant CTLA-4-Ig fusion proteins tested
were
statistically superior in potency to both Orencia and LEA29Y-Ig fusion
proteins with p <
0.05, as determined by 1 way ANOVA with post hoc Dunnett and BonfeiToni tests,
respectively, discussed supra (e.g., the mutant CTLA-4-Ig fusion proteins have
a greater
ability than Orencia and/or LEA29Y-Ig fusion proteins in inhibiting or
suppressing
memory T cell proliferation in vitro in human PBMC proliferation assays
(recall antigen
stimulation)).
It is believed that given the increased abilities of mutant CTLA-4-Ig fusion
proteins of the invention to suppress or inhibit proliferation of memory T
cells (e.g.,
human memory T cells) in in vitro assays as compared to Orencia and/or LEA29Y-
Ig
fusion proteins, such mutant proteins should also exhibit increased
immunosuppressive
potencies in in vivo therapeutic and/or prophylactic methods or applications
as compared
to Orencia , LEA29Y-Ig, and/or human CTLA-4-Ig (e.g., human CTLA-4-IgG2)
fusion
proteins. In one aspect, mutant CTLA-4-Ig proteins of the invention are
believed to have a
greater ability to suppress or inhibit proliferation of memory T cells (e.g.,
human memory
T cells) in an in vivo method or application compared to Orencia , LEA29Y-Ig,
and/or
human CTLA-4-Ig (e.g., human CTLA-4-IgG2) fusion proteins, such as in, e.g.,
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therapeutic and/or prophylactic methods for suppressing or inhibiting an
immune response
in a subject (e.g., in the in vivo treatment of immune system diseases or
disorders in, e.g., a
mammal, such as, e.g., a human), methods for suppressing or inhibiting
rejection of a
tissue or organ transplant from a donor by a recipient (e.g., by a mammal,
such as, e.g., a
human), and/or other treatment or diagnostic methods described elsewhere
herein.
EXAMPLE 8
Measuring Biological Activity of Mutant CTLA-4-Ig Molecules Using Human MLR
(Mixed Lymphocyte Reaction) Assays.
CTLA-4-Ig and variants thereof are potent inhibitors of primary alloresponses
in
vitro (Vaughan, A. N. et al., J. Irnmunol. 165:3175-3181 (2000); Wallace P.
M., et al.,
Transplantation 58:602-610 (1994)). To measure improved activity of mutant
CTLA-4-Ig
proteins in such assays, a human mixed lymphocyte reaction (MLR) cell
proliferation
assay was developed.
Human blood (freshly collected from a human donor program) was diluted with an
equal volume of PBS and fractionated to isolate PBMCs using a Histopaque
(Sigma,
#10771) Ficoll gradient as per the manufacturer's recommended conditions. PBMC
from
one donor were diluted in RPMI medium (Sigma, #R8758) supplemented with 10%
FBS
(Hyclone # SV30014.03) and lx PSG (Invitrogen, #10378-016) and added to 96-
well
culture plates (BD Biosciences, #353077) at a density of 1 x 105 cells/well.
PBMC from a
different donor were irradiated at 2500 rads, diluted in the same media and
added to the
same plates at a density of 1 x 105 cells/well. Test compounds were serially
diluted in the
same medium and added to wells in quadruplicate. After incubation at 37 C for
5 d, 3H
thymidine (GE Healthcare, #TRI(758-5MCI) was added at 1 Xi/well and plates
were
incubated at 37 C for an additional 18 hr. Cells were harvested with a cell
harvester
(FilterMate Omnifilter-96 Harvester, Perkin Elmer) using the manufacturer's
recommended conditions and measured for 3H thymidine incorporation using a
scintillation counter (Wallac Trilux, #1450-421). Cell proliferation data was
analyzed
with GraphPad Prism 5 software using a non-linear regression curve fit model
(sigmoidal
dose-response, variable slope) and the least squares fit method. The IC50
parameters and
their associated 95% confidence intervals are reported.
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Figure 9 shows cell proliferation curves from representative MLR proliferation
assays involving an exemplary mutant CTLA-4-Ig fusion protein of the
invention: D3-
IgG2. Orencia and LEA29Y-Ig fusion proteins were included as controls for
comparison. The graph is a plot of 3H thymidine incorporation (cpm) versus
protein
concentration (nM). 3H thymidine incorporation, which is indicative of the
degree of cell
proliferation, is measured by standard techniques. These results demonstrate
that D3-IgG2
has significantly higher potency than Orencia and/or LEA29Y-Ig fusion
proteins in
inhibiting or suppressing primary allostimulation of T cells in vitro (e.g.,
D3-IgG2 has a
greater ability to suppress or inhibit primary allostimulation of T cell
proliferation in an in
vitro MLR assay than Orencia or LEA29Y-Ig fusion proteins).
This MLR assay was performed on a number of other mutant CTLA-4-Ig fusion
proteins of the invention. Table 9 provides a summary of the data for a set of
exemplary
mutant CTLA-4-Ig fusion proteins of the invention. Table 9 presents
comparisons of
mean IC50 values (nanomolar (nM)) for exemplary mutant CTLA-4-Ig fusion
proteins
versus reference controls (Orencia and LEA29Y-Ig fusion proteins) in the MLR
assay.
IC50 values from two separate experiments were averaged to provide mean IC50
values.
The term "SD (mean log IC50)" represents the standard deviation in mean log
IC50
values. The mean IC50 values for the mutant CTLA-4-Ig fusion proteins shown in
Table
9 were lower than the respective mean IC50 values of Orencia and LEA29Y-Ig
fusion
proteins.
In one aspect, the invention provides mutant CTLA-4-Ig fusion proteins that
are
believed to be superior in potency to Orencia and/or LEA29Y-Ig fusion
proteins (e.g.,
the mutant CTLA-4-Ig fusion proteins are believed to have a greater ability to
suppress or
inhibit primary allostimulation of T cell proliferation in an in vitro MLR
assay than
Orencia and/or LEA29Y-Ig fusion proteins).
It is believed that based on the expected enhanced abilities of mutant CTLA-4-
Ig
fusion proteins of the invention to suppress or inhibit primary
allostimulation of T cells
(e.g., human T cells) in in vitro assays as compared to Orencia and/or LEA29Y-
Ig fusion
proteins, such mutant proteins should also exhibit increased immunosuppressive
potencies
in in vivo therapeutic and/prophylactic methods or applications as compared to
Orencia
and/or LEA29Y-Ig fusion proteins.
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In one aspect, mutant CTLA-4-Ig fusion proteins of the invention have
significantly higher potency than Orencia , LEA29Y-Ig, and/or human CTLA-4-Ig
(e.g.,
human CTLA-4-IgG2) fusion proteins in inhibiting or suppressing primary
allostimulation
of T cells in vitro (e.g., mutant CTLA-4-Ig fusion proteins have a greater
ability to
suppress or inhibit primary allostimulation of T cell proliferation in an in
vitro MLR assay
than Orencia , LEA29Y-Ig, and/or human CTLA-4-Ig) fusion proteins. In one
aspect, a
mutant CTLA-4-Ig of the invention is believed to have a greater ability to
suppress or
inhibit primary allostimulation of T cells (e.g., human T cells) in an in vivo
method or
application compared to Orencia , LEA29Y-Ig, and/or human CTLA-4-Ig fusion
proteins, such as in, e.g., a therapeutic and/or prophylactic method of
suppressing or
inhibiting an immune response in a subject (e.g., in the in vivo treatment of
immune
system diseases or disorders in a mammal, such as e.g., a human), a method of
suppressing
or inhibiting rejection of a tissue or organ transplant from a donor by a
recipient (e.g., by a
mammal, such as e.g., a human), and/or other treatment or diagnostic methods
described
elsewhere herein.
Table 9. Summary of Data From Exemplary MLR Assays
Fusion Protein Mean IC50 Mean Log IC50 SD (Mean Log
(dimer) (nM) (nM) IC50) (nM)
Orencia fusion
protein dimer 12.53 1.05 0.23
LEA29Y-Ig 0.92 -0.19 0.48
D3-IgG2 0.06 -1.26 NA
D3-12-IgG2 0.09 -1.11 0.34
D3-14-IgG2 0.08 -1.20 0.43
D3-17-1g02 0.09 -1.15 0.43
D3-20-IgG2 0.14 -1.11 0.64
D3-27-IgG2 0.13 -1.29 0.86
D3-29-IgG2 0.11 -1.14 0.54
D3-34-IgG2 0.10 -1.09 0.39
D3-53-IgG2 0.02 -1.64 0.11
D3-54-IgG2 0.07 -1.13 NA
D3-56-IgG2 0.06 -1.23 NA
D3-69-IgG2 0.04 -1.41 NA
D3-71-IgG2 0.05 -1.32 NA
D3-75-IgG2 0.08 -1.11 NA
D3-76-IgG2 0.08 -1.11 NA
Note: The term "NA" in Table 9 means "not available".
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EXAMPLE 9
An adult human patient suffering from rheumatoid arthritis may be treated with
a
soluble mutant CTLA-4-Ig fusion protein as follows. A pharmaceutical
composition
comprising a soluble mutant CTLA-4-Ig fusion protein of the invention and a
.. pharmaceutically acceptable excipient or carrier (e.g., PBS) is prepared.
An exemplary
soluble mutant CTLA-4-Ig fusion protein comprises two identical monomeric
mutant
CTLA-4-Ig fusion proteins linked together by one or more disulfide bonds,
wherein each
such monomeric fusion protein comprises a mutant CTLA-4 ECD polypeptide of the
invention comprising a polypeptide sequence selected from any of SEQ ID NOS:1-
73
.. fused at its C-ten-ninus to the N-terminus of a human IgG2 Fc polypeptide.
Exemplary
fusion proteins include those comprising polypeptide sequences set forth in
any of SEQ ID
NOS:74-79, 197-200, 205-214, and 219-222. Such fusion proteins are typically
expressed
in dimeric form. The concentration of the fusion protein in the pharmaceutical
composition may be in a range of from about 0.05 mg/ml to about 200 mg/ml,
from about
.. 1 mg/ml to about 150 mg/ml, from about 25 mg/ml to about 120 mg/ml, from
about 1
mg/m1 to about 100 mg/ml, from about 25 mg/ml to about 100 mg/ml, from about
50
mg/nil to about 100 mg/ml, from about 50 mg/ml to about 75 mg/ml, from about
100
mg/ml to about 150 mg/ml, and the like. For example, the fusion protein
concentration in
the pharmaceutical composition may be about 1 mg/ml, 5 mg/ml, 10 mg/ml, 15
mg/ml, 25
.. mg/ml, 30 mg/ml, 40 mg/ml, 50 mg/ml, 60 mg/ml, 70 mg/ml, 80 mg/ml, 90
mg/ml, 100
mg/ml, 150 mg/ml, or 200 mg/ml. The pH of such pharmaceutical composition is
about
pH 4 to about pH 10, including about pH 5 to about pH 9, about pH 6.5 to about
pH 8.5,
preferably about pH 6.0 to pH 8.0, about 6.5 to pH 7.5, or about pH 7.0 to
about pH 8Ø
Treatment of the patient's rheumatoid arthritis is carried out by
administering a
.. therapeutically effective amount of the mutant CTLA-4-Ig to the patient
(e.g., effective
dose) by intravenous or subcutaneous injection. The site of injection may be,
e.g., the
patient's arm, torso, or leg. The effective dose of the mutant CTLA-4-Ig
fusion protein
administered is typically, but not limited to, e.g., from about 0.01 mg/kg to
about 100
mg/kg body weight of the adult human patient, such as, e.g., from about 0.01-
5.0 mg/kg,
.. about 0.01-3.0 mg/kg, about 0.05-2.5 mg/kg, about 0.1-2.0 mg/kg, about 0.1-
1.0 mg/kg,
about 0.01-0.05 mg/kg, about 0.5-1.5 mg/kg. about 1.0-4.0 mg/kg, about 1.0-3.0
mg/kg,
about 1.0-2.0 mg/kg, including, but not limited to, about 0.01 mg/kg, 0.05
mg/kg, 0.075
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mg/kg, 0.1 mg/kg, 0.15 mg/kg, 0.2 mg/kg, 0.25 mg,/k..cl, 0.3 mg/kg, 0.5 mg/kg,
0.75 mg/kg,
1 mg/kg, 1.25 mg/ml, 1.5 mg/kg, 2 mg/kg, 2.5 mg/kg, 3 mg/kg, 4 mg/kg, 5 mg/kg,
10
mg/kg, 20 mg/kg, 25 mg/kg, 50 mg/kg, 75 mg/kg, or 100 mg/kg body weight of the
patient
is administered to the patient. Alternatively, an effective amount or dose or
dose range
described in the "Methods of the Invention" section above may be used. The
dose of the
fusion protein to be administered is determined based on the potency of the
fusion protein
and/or the severity of the patient's symptoms or signs of rheumatoid
arthritis. The total
amount of mutant CTLA-4-Ig fusion protein administered to the patient may be,
e.g., from
about 0.01 mg to about 100 mg, typically from about 1 mg to 100 mg, from about
10 mg
to 100 mg, from about 10 mg to about 75 mg, or from about 10 to about 50 mg.
The
volume of pharmaceutical composition administered to the patient is determined
based
upon the concentration of fusion protein in the composition and the dose of
fusion protein
to be administered. For subcutaneous injection, one to two milliliters of the
pharmaceutical composition comprising the fusion protein is typically
administered per
injection. For intravenous injection, an appropriate volume of the
pharmaceutical
composition comprising the fusion protein can be administered.
Following injection of the initial dose, a second identical dose of the fusion
protein
may be administered to the patient subcutaneously (e.g., s.c. injection) or
intravenously
(e.g., i.v. injection) at, e.g., 1, 2, 3, or 4 weeks after the initial dose.
The dosing schedule
may be one dose every two weeks, one dose/month, one dose every two months,
etc.
depending, e.g., upon the patient's condition. Subsequent doses may be
administered
every four weeks or more or less frequently, as necessary. The frequency of
dosing may
vary depending upon the patient's condition and may depend upon the severity
of the
patient's symptoms or signs of rheumatoid arthritis.
In an exemplary aspect, an amount of a pharmaceutical composition comprising a
mutant CTLA-4-Ig fusion protein dimer of the invention (such as D3-29-IgG2, D3-
54-
IgG2, D3-56-IgG2, D3-69-IgG2, etc.) and a pharmaceutically acceptable
excipient
sufficient to provide a dose of the fusion protein dimer of about 0.5 mg/kg
body weight is
administered by subcutaneous injection to a human suffering from rheumatoid
arthritis
once per week or once per month, as needed, depending upon the patient's
condition and
response to the drug.
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In another exemplary aspect, an amount of a pharmaceutical composition
comprising a CTLA-4-Ig fusion protein dimer of the invention (such as D3-29-
IgG2, D3-
54-IgG2, D3-56-IgG2, D3-69-IgG2, etc.) and a pharmaceutically acceptable
excipient
sufficient to provide a dose of the fusion protein dimer of about 10 mg/kg is
administered
intravenously to a human suffering from rheumatoid arthritis once per week or
once per
month, as needed, depending upon the patient's condition and response to the
drug.
Standard i.v. procedures can be used for such administration. For example, the
pharmaceutical composition can be infused into the human with another fluid,
such as a
sterile saline solution, dextrose solution, or other isotonic solution, using
a standard
continuous intravenous drip through a standard intravenous access device.
Each above-described treatment method by s.c. or i.v. injection is expected to
reduce or alleviate one or more signs, symptoms, or biological responses
associated with
rheumatoid arthritis, such as, e.g., inflammation, joint tenderness, joint
swelling, pain,
tissue atrophy, and stiffness, in the patient. Such treatment may reduce
further progression
of the disease in the patient, particularly in the connective, muscular, and
skeletal tissues.
For example, such treatment may reduce the progression of damage to or
deterioration of
connective tissue, atrophy muscular tissue, bone, joints, cartilage, and/or
spinal column,
and the like in the patient. Additional clinical symptoms of the disease,
including damage
caused to the skin, central nervous system or organs, may also be lessened or
alleviated.
Such treatment may also improve physical functioning of the patient.
EXAMPLE 10
An adult human patient undergoing maintenance therapy for prevention of organ
transplant rejection may be treated with a soluble mutant CTLA-4-Ig fusion
protein as
follows. A pharmaceutical composition comprising a soluble mutant CTLA-4-Ig
fusion
protein of the invention and a pharmaceutically acceptable excipient or
carrier (e.g., PBS
or the like) is prepared. An exemplary soluble mutant CTLA-4-Ig fusion protein
comprises two identical monomeric mutant CTLA-4-Ig fusion proteins linked
together by
one or more disulfide bonds, wherein each such monomeric fusion protein
comprises a
mutant CTLA-4 ECD polypeptide of the invention comprising a polypeptide
sequence
selected from any of SEQ ID NOS:1-73 fused at its C-terminus to the N-terminus
of a
human IgG2 Fc polypeptide. Exemplary fusion proteins include those comprising
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polypeptide sequences set forth in any of SEQ ID NOS:74-79, 197-200, 205-214,
and 219-
222. The concentration of the fusion protein in the pharmaceutical composition
may be in
a range of from about 0.05 mg/ml to about 200 mg/ml, from about 1 mg/ml to
about 150
mg/ml, from about 25 mg/m1 to about 120 mg/ml, from about 1 mg/ml to about 100
mg/ml, from about 25 mg/ml to about 100 mg/ml, from about 50 mg/ml to about
100
mg/ml, from about 50 mg/ml to about 75 mg/ml, from about 100 mg/ml to about
150
mg/ml, and the like. For example, the fusion protein concentration in the
pharmaceutical
composition may be about 1 mg/ml, 5 mg/ml, 10 mg/ml, 15 mg/ml, 25 mg/ml, 30
me/ml,
40 mg/ml, 50 mg/ml, 60 mg/ml, 70 mg/ml, 80 mg/ml, 90 mg/ml, 100 mg/ml, 150
mg/ml,
or 200 mg/ml. The pH of such pharmaceutical composition is about pH 4 to about
pH 10,
including about pH 5 to about pH 9, about pH 6.5 to about pH 8.5, about pH 6.0
to pH 8.0,
about 6.5 to pH 7.5, or about pH 7.0 to about pH 8Ø
Maintenance therapy for prevention or suppression of organ transplant
rejection is
carried out by administering a therapeutically effective amount of the mutant
CTLA-4-Ig
to the patient (e.g., effective dose) who has received an organ transplant
(e.g., kidney
transplant) by intravenous or subcutaneous injection. The site of injection
may be, e.g.,
the patient's arm, torso, or leg. The effective dose of the mutant CTLA-4-Ig
fusion
protein administered is typically, but not limited to, e.g., from about 0.01
mg/kg to about
100 mg/kg body weight of the adult human patient, such as, e.g., from about
0.01-5.0
mg/kg, about 0.01-3.0 mg/kg, about 0.05-2.5 mg,/kg, about 0.1-2.0 mg/kg, about
0.1-1.0
mg/kg, about 0.01-0.05 mg/kg, about 0.5-1.5 mg/kg, about 1.0-4.0 mg/kg, about
1.0-3.0
mg/kg, about 1.0-2.0 mg/kg, including, but not limited to, about 0.01 mg/kg,
0.05 mg/kg,
0.075 mg/kg, 0.1 mg/kg, 0.15 me/kg, 0.2 mg/kg, 0.25 mg/kg, 0.3 mg/kg, 0.5
mg/kg, 0.75
mg/kg, 1 mg/kg, 1.25 mg/ml, 1.5 mg/kg, 2 mg/kg, 2.5 mg/kg, 3 mg/kg, 4 mg/kg, 5
mg/kg,
10 mg/kg, 20 mg/kg, 25 mg/kg, 50 mg/kg, 75 me/kg, or 100 mg/kg body weight of
the
patient is administered to the patient. Alternatively, an effective amount or
dose or dose
range described in the "Methods of the Invention" section above may be used.
The dose
of the fusion protein to be administered is determined based on the potency of
the fusion
protein and/or the severity of the patient's symptoms or signs of organ
transplant rejection.
The total amount of mutant CTLA-4-Ig fusion protein administered to the
patient may be,
e.g., from about 0.01 mg to about 100 mg, typically from about 1 mg to 100 mg,
from
about 10 mg to 100 mg, from about 10 mg to about 75 mg, or from about 10 to
about 50
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mg. The volume of pharmaceutical composition administered to the patient is
determined
based upon the concentration of fusion protein in the composition and the dose
of fusion
protein to be administered. The fusion protein can be administered on any day
post-
transplant, e.g., day 1, 4, 7, 14, 28, 56, 84, etc. post-transplant. For
subcutaneous
injection, one to two milliliters of the pharmaceutical composition is
typically
administered. For intravenous injection, an appropriate volume of the
pharmaceutical
composition comprising the fusion protein can be administered.
Following injection of the initial dose, a second identical dose of the fusion
protein
may be administered to the patient subcutaneously or intravenously at 1, 2, 3,
or 4 weeks
after the initial dose. The dosing schedule may be one dose every two weeks,
one
dose/month, one dose every two months, etc. depending, e.g., upon the
patient's condition.
Subsequent doses may be administered every four weeks or more or less
frequently, as
necessary, and continued, if desired, on a monthly basis. The frequency of
dosing may
vary depending upon the patient's condition and may depend upon the severity
of the
patient's symptoms or signs of organ transplant rejection.
Such treatment is expected to reduce or alleviate one or more signs, symptoms,
or
biological responses associated with organ transplant rejection, such as,
e.g., acute
rejection of the transplanted organ, chronic rejection of the transplanted
organ, decrease in
function of the transplanted organ, increase in serum creatinine levels in the
patient, and/or
increased infiltration of T cells into the transplanted organ. Such treatment
may reduce the
likelihood of rejection of the transplanted organ by the patient's immune
system.
EXAMPLE 11
Pharmacokinetic Assessment of Mutant CTLA-4-IgG2 Fusion Proteins in Rats.
The serum concentration of a therapeutic after external administration to a
living
organism greatly influences therapeutic efficacy, and is determined by
pharmacokinetic
(PK) evaluation. In the following procedure, PK profiles were assessed in rats
for
representative mutant CTLA-4-IgG2 test articles D3-29-1gG2, D3-54-1gG2, D3-56-
IgG2,
D3-69-1g,G2, and D3-75-IgG2 in comparison to both hCTLA-4-IgG2 and Orencia
fusion
protein test articles. The study design, and data generation and
interpretation are described
forthwith.
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In Life Study Design.
Weight-matched, male Hans Wistar rats were used after an acclimatization
period
of at least 5 days. Test article dosing volumes were calculated for individual
animals
based on their weight such that all received lmg/kg of test article. A typical
150 gram (g)
rat therefore received 150 41 dosing volume since every test article was
prepared at
I mg/ml in PBS. A single administration of a mutant CTLA-4-IgG2 test article
described
above, hCTLA-4IgG2, or Orencia fusion protein was delivered, either as an
intravenous
(i.v. or IV) bolus, or by the subcutaneous (abbreviated as "s.c." or "SC")
route. The study
size was sufficient for a minimum of four blood samplings of 300 pl per
timepoint, while
restricting the blood volume removed from any given rat to no more than 10%
total blood
volume. The blood sampling time course was either pre-dose, 5 minutes (min),
30 min, 2
hours (h), 4 h, 8 h, 1 day (d), 2 d, 3 d, 4 d, 6 d, 8 d, 10 d, 12 d, and 14 d
post-dose, or 5
min. 30 min, 2 h, 4 h, 8h, 1 d, 2 d, 3 d, 4 d, 6 d, 8d, 10 d,11 d, 12d, 13d,
14 d and 15 d
post-dose for i.v and s.c. administrations, respectively. Serum was prepared
from
individual blood samples, and tested by ELISA to quantify the presence of the
administered test article.
PK ELISA Method.
The mutant CTLA-4-IgG2, hCTLA-4IgG2, or Orencia fusion protein present in
the serum samples were bound to human CD80-murine IgG (described above) pre-
coated
onto microtiter plates. Detection was achieved by addition of a Horse Radish
Peroxidase
(HRP) conjugated goat anti-human IgG (Jackson ImmunoResearch #109-035-098).
Quantification was through the use of a chromogenic HRP substrate, 3,3' ,5,5'-
tetramethylbenzidine (TMB), plus hydrogen peroxide (Kem-En-Tec #4390A),
whereby
the reaction was stopped by addition of 0.2N sulphuric acid (H2SO4), and
optical
absorbance was measured at 450 nm by a spectrophotometer. Serum samples were
pre-
diluted 1/20 before addition to the ELISA plate such that matrix was
normalized to 5% rat
sera, and further diluted in 5% rat sera for a total of eight dilutions. The
concentration of
each diluted serum sample was quantified against a standard curve prepared
using
titrations of the same test article spiked into 5% rat sera. The standard
curve ranged from
10 to 0.078 ng/ml, and the accuracy range was determined to be from twice
background to
5 ng/ml in 5% rat sera. The quality of the standard curve was assessed by
quality controls
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(QC) of the same test article prepared in 5% rat sera at high, middle and low
concentrations of the standard curve accuracy range. The QC acceptance
criterion was for
the observed QC concentration to be within 20% of the expected QC
concentration. The
concentration of an individual unknown serum sample was generated by averaging
the
concentrations assigned to dilutions with optical densities (ODs) within the
accuracy range
of the standard curve. At least 4 individual serum samples were used to
calculate the
mean serum concentration at each nominal timepoint.
PK Parameters.
Figures 15A and 15B show PK profiles for Orencia fusion protein, hCTLA-4-
IgG2, and the mutant CTLA-4-IgG2 fusion proteins administered at 1 mg/kg as a
single
(A) intravenous (IV) bolus or (B) subcutaneous (SC) injection in rats. The
error bars
represent standard deviation of the mean (SD). The dashed line represents the
lower limit
of quantification for the ELISA (-3 ng/ml for test article in 100% sera). The
mean serum
concentration at each nominal timepoint after test article administration at
time 0 h
comprises the datapoints of the semi-log concentration-time profile in Figure
15.
The mean serum concentrations were used to generate PK parameters using
WinNonLin model 201 (i.v.-bolus input), or model 200 (extravascular input) for
the i.v.
(IV) or s.c. (SC) dosing routes, respectively. Table 10 summarizes the key PK
parameters
for s.c. and i.v. administration routes, respectively.
Table 10. Summary of PK Parameters for Orencia fusion protein, hCTLA-4-
IgG2, and Mutant CTLA-4-IgG2 Fusion Proteins Administered at 1 mg/kg as a
Single I.V. or S.C. Bolus to Rats
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Compound Route Cmax (ug/L) T1/2 (h) AUC (h*ng/L) CI (ml/h/kg) Vz (ml/kg)
Orencia SC 3.3 70.0 391 2.6
258.13
CTLA-4IgG2 SC 5.9 45.0 838 1.2
77.49
03-29 SC 4.6 11.2 650 1.5
24.90
D3-54 SC 4.5 23.6 528 1.9
64.52
D3-56 SC 7.4 23.7 1049 1.0
32.67
D3-69 SC 6.0 28.1 967 1.0
41.97
D3-75 SC 9.0 56.4 1204 0.8
67.59
Orencia IV 22.3 42.3 728 1.37
83.9
CTLA-4IgG2 IV 66.2 49.8 2483
0.40 29.0
D3-29 IV 43.0 33.0 912 1.10
52.2
D3-54 IV 20.6 39.4 1034 0.97
55.0
D3-56 IV 34.2 15.3 1822 0.55
12.1
D3-69 IV 81.9 83.0 2133 0.47
56.1
03-75 IV 30.1 65.4 2326 0.43
40.5
Cmax refers to the maximum serum concentration of test article. The terminal
half-life value (T1/2) is the time taken in hours for the concentration of
test article in the
serum to decline by half during the termination phase of the concentration-
time profile.
The area under the serum concentration-time curve (AUC) is quantified from
time zero to
infinity using the trapezoidal rule. The clearance (Cl) was calculated using
the equation
dose/AUC, whilst the volume of distribution (Vz) of the terminal phase was
calculated
using the equation Cl/k.
The bioavailability factor (F) for each compound is presented in Table 11, and
was
determined by calculating the AUC by the subcutaneous route/ AUC by the
intravenous
route.
Table 11. Bioavailability Comparison of Orencia Fusion Protein, hCTLA-4-1g2,
D3-29-IgG2, D3-54-IgG2, D3-56-IgG2, D3-69-IgG2, and D3-75-IgG2 Fusion
Proteins
Compound Bioavailability
Orencia 0.54
CTLA-4IgG2 0.34
D3-29 0.71
D3-54 0.51
D3-56 0.58
D3-69 0.45
D3-75 0.52
Human CTLA-4IgG2 and Orencia fusion protein displayed similar PK profiles
despite their difference in IgG frameworks, implying that the human IgG2 and
mutated
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human IgG1 Fc portions of these respective test articles have comparable PK
activity
when the functional domain is constant. By inference, any changes seen in PK
profile for
mutant CTLA-4-IgG2 fusion proteins as compared to Orencia fusion protein
should
therefore be attributable to differences in the functional domain, and not the
Fc portion.
For each mutant CTLA-4-IgG2 fusion protein, elimination was slow as suggested
by the long half-life values and large area under the curves. Half-lives
ranged from 11.2 to
56.4 hr for SC dosing, and from 15.3 to 83.0 hours (h) for IV dosing in
comparison to
Orencia fusion protein, which had a half-life of 70.0 or 42.3 hours when
administered by
SC or IV routes, respectively. AUC values for the mutant CTLA-4-IgG2 fusion
proteins
were on average superior to the Orencia fusion protein. After SC dosing the
mean was
879.5 +/- 281.6 h*kg*ng/L/mg as compared to 391h*kg*ng/L/mg for SC Orencia
fusion
protein, while an IV administration gave an average AUC of 1645.5 +1-
641.1h*kg*ng/L/mg as compared to 728h*kg*ng/L/mg for IV Orencia fusion
protein.
The volume of distribution was similar for both routes of administration in
that
mutant CTLA-4-IgG2 fusion proteins were distributed outside the serum but
inside the
extravascular fluid as suggested by the average value of 44.8 ml/kg, which is
above the
plasma reference volume of 30 ml/kg, and within the extracellular fluid
reference limit of
300 mllkg for a standard rat (Davies, B. et al., Pharm. Res. 10(7):1093-95
(1993)).
Bioavailability was also similar for the majority of the mutant CTLA-4-Ig02
fusion proteins, with an average of 0.6+/- 0.1, which compared favorably to
the 0.53
bioavailability of Orencia fusion protein.
Finally, Cmax was generally higher for the mutant CTLA-4-IgG2 fusion proteins
as compared to the Orencia fusion protein. Cmax values ranged from 4.5 to
9.3ug,/L for
SC dosing, and from 20.6 to 81.9ug/L for IV dosing in comparison to the
Orencia fusion
protein, which had a Cmax of 3.3 or 22.3ug/L when administered by SC or IV
routes,
respectively.
Overall, the PK data showed that all assessed mutant CTLA-4-IgG2 fusion
proteins typically had a non-inferior PK profile to the Orencia fusion
protein when
administered to rats at lmg/kg via SC Or IV routes, and that IgG1 or IgG2 Fe
portions
were comparable when the functional domain was constant.
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EXAMPLE 12
This example describes a method for creating a stably transfected cell line
for
expressing mutant CTLA4-Ig fusion proteins of the invention, using the cell
line for
routine laboratory scale production of the mutant CTLA4-Ig fusion protein, and
purifying
the mutant CTLA-4-Ig fusion proteins from cell expression media. Although this
example
specifically describes a method for creating a stably transfected CHO-Kl cell
line for
expressing the D3-54-IgG2 fusion protein, using such cell for laboratory scale
production
and purifying the protein from media, the methods described herein can be used
with any
mutant CTLA-4-Ig fusion protein of the invention and/or any appropriate cell
line
disclosed above.
Creation of Stably Transfected Cell Line.
Materials.
CHO-Kl naive (untransfected) cells: CHO-Kl cells adapted to serum-free
suspension growth in chemically-defined medium (Cell ID: M4-PeM-0436-112-01)
were
stored in liquid nitrogen vapor phase (Dewar MVE1536P). One vial of M4-PeM-
0436-
112-01 was thawed and cultured with CD OptiCHOTM medium (Invitrogen, #12681)
in
shake flasks. The cultures provided cells for transfection and conditioned
medium for
growth and cloning. All cultures were grown at 37 C, 5% CO2.
Plasmid: DNA encoding the D3-54 mutant CTLA-4 ECD fused to a human IgG2a
Fc region was inserted into the CET1019AS UCOE vector (Millipore) and the
resulting
plasmid CET1019AS-D3-54-IgG2 was used for all transfections.
Cell culture medium: CD Opti-CHO (Invitrogen #12681) chemically-defined
animal component-free medium, supplemented with 2% v/v 200 mM L-glutamine
(Invitrogen #25031), was used for all cultures.
Conditioned medium: Conditioned medium was obtained by cultivating the
parental CHO-K1 cell line in CD Opti-CHO medium. At cell counts > 5 x 105
cells/ml, the
cell culture was centrifuged and the conditioned medium supernatant was
sterile-filtered.
Conditioned medium was made fresh each day for use or stored at 2-8 C for up
to 7 days.
50% conditioned medium: Conditioned medium (above) combined with an equal
volume of fresh cell culture medium; made fresh each day it is used.
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Analytical Methods.
Cell count and viability determination were performed with a Cedex or Cedex
HiRes cell counter (Innovatis).
Initial screening of clones expressing the mutant CTLA-4-Ig fusion protein (D3-
54-IgG2) for production was performed by ELISA. ELISA plates were coated with
hCD80-murine Ig fusion protein overnight. The following day, samples to be
analyzed
were transferred to the ELISA plates at 50- and 200-fold dilutions in
duplicate. After two
hours incubation, anti-human IgG-HRP antibody was added and incubated for 30
minutes.
The plates were developed with TMB and read at 450nm. Raw optical densities
(OD)
were reported.
Quantitative determination of the D3-54-IgG2 fusion protein concentration was
performed by a Protein A HPLC method using a Poros A/20 column (ABI # 1-5024-
12).
Two buffers were used: Buffer A: 50 mM phosphoric acid, 150 mM potassium
chloride,
pH 7.6 0.1 and Buffer B: 50 mM phosphoric acid, 150 mM potassium chloride,
pH 2.5
0.1. Both buffers additionally had 5% isopropanol added. Equilibration and
wash after
sample injection was with 42% Buffer A and 58% Buffer B (pH 6.5). Elution was
a linear
gradient to 12% Buffer A and 88% Buffer B over 1 minute.
Procedure.
The naïve adherent CHO-Kl cells used for the creation of stable cell lines
used in
GMP production of D3-54-IgG2 fusion protein were adapted to suspension growth
in
chemically defined CD OptiCHOI'm medium. A vial of these naive CHO-KI cells
was
thawed and grown in 125 ml shake flasks containing CD OptiCHOTM medium to a
density
of 5 x 105 viable cells/ml. 2 x 106 viable cells were resuspended in 400 1 of
50%
conditioned medium and combined with 20 g plasmid DNA (D3-54-IgG2 in a
CET1019AS UCEO vector) in a cuvette. Electroporation was performed with a Gene
Xcell Pulser (BioRad) at 320 volts (V) with a square wave pulse length of 15
milliseconds
(ms). Duplicate transfections were performed and then the cells were pooled.
The pooled
cells were transferred to a T-25 flask containing 5 ml of 50% conditioned
medium and
incubated for two days.
Transfected cells were either directly dispensed into 96-well plates for
cloning or
cultured with antibiotic selection until a stable pool was obtained, and then
dispensed into
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96-well plates. Two days after electroporation, the culture was diluted to
1250 cells/ml in
conditioned medium containing 8 p g/m1 of puromycin for selection pressure.
The cells
were dispensed into 96-well plates at 2001.11 per well (250 cells/well). The
plates were
incubated for approximately 10 days to kill untransfected and transiently-
transfected cells.
After 10-12 days, every well in every plate was visually inspected to identify
wells with
single colonies. These wells were later re-inspected to verify they contained
single,
healthy colonies suitable for expansion into 24-well plates.
Two days after electroporation, the culture was centrifuged and resuspended in
50% conditioned medium containing 7 p g/ml of puromycin for selection
pressure. A
control flask was also inoculated with untransfected cells in the same medium.
Based on
on-going optimization studies, the puromycin concentration was increased to 8
jig/ml after
3 days. The stable pool was generated 10-12 days after selection, when all
cells in the
control flask died. Product expression in the stable pool was verified by
protein A HPLC
and culture viability was verified to be > 95%. The cells were serially
diluted in
conditioned medium without puromycin to a final density of 3.8 cells/ml. The
cells were
seeded onto 96-well plates at 200 11 per well (75 cells/plate or 0.8
cells/well).
After one day every well in every plate was visually inspected to identify
wells
with single cells or colonies. The next day, wells with single colonies of 2-4
cells were
selected. Any wells with more than two colonies were eliminated. A second
operator
verified the selections. The wells were later re-inspected to verify they
contained single,
healthy colonies suitable for expansion into 24-well plates
Clones from 96-well plates were expanded into 24-well plates containing 1 nil
of
conditioned medium per well with 8 g/m1 of puromycin. The entire contents of
the
selected wells from the 96-well plates with single colonies were transferred
to individual
wells in the 24-well plates. 200 1 was taken from each new well in the 24-
well plate to
wash the corresponding well in the 96-well plate and transferred back. For
backup, 200 Ml
of conditioned medium containing 8 g/m1 of puromycin was added back to each
well in
the 96-well plates.
After 1-3 days, each well in the 24-well plates was sampled and tested for D3-
54-
IgG2 expression by ELISA. Clones for further expansion were selected based on
the raw
ELISA OD values as well as demonstration of adequate growth.
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The top 35-40 clones, based on EL1SA and observable growth results were
expanded into T-25 flasks containing 5 ml of conditioned medium with 8 g/ml
of
puromycin. The entire contents of each of the selected wells from the 24-well
plates were
transferred to individual T-25 flasks. Residual cells in the wells were washed
with the
same medium and added to the corresponding T-25 flask. For backup, 1 ml of
conditioned
medium containing 8 ug/m1 of puromycin was added back to each well in the 24-
well
plates.
The number of clones was further reduced by selecting for clones with the
highest
productivity. Cells were resuspended in fresh medium at 1-2 x 105 viable
cells/ml and
seeded into T25 flasks (5 ml culture) or 125 ml shake flasks (12 ml culture).
The cultures
were incubated for 22-24 hours and then a final cell density and viability
determination
was made and a sample was taken for product concentration determination by
Protein A
HPLC. Productivity was calculated by dividing the total amount of protein
produced by
the total number of viable cells in the flask and dividing by the culture
duration. The units
were converted to picograms per cell per day or "pcd". Clones were ranked
according to
their pcd values, but clones that did not exhibit significant growth were
omitted. The top
clones were expanded to 125 ml shake flasks for cryopreservation and further
evaluation
of growth and productivity.
Clones to be further evaluated were seeded into 250 ml shake flasks at 1 x 105
viable cells/m1 in 50 ml fresh medium. When the cell density reached 1 x 106
viable
cells/ml, the culture was passaged into a new shake flask, again at 1 x 105
viable cells/ml
in 50 ml fresh medium. The passaging was repeated once more. During this third
passage, the culture was sampled daily for cell count, viability, and product
concentration
determination by Protein A HPLC.
The top clones expressing D3-54-IgG2 fusion protein based on the growth and
specific production rates were selected for subcloning. Subcloning was
performed by
limiting dilution as described in the section above for stable pools, with the
exception that
puromycin was not used at any time. Expansion, screening, and evaluation of
subclones
were also performed as described above.
Selected subclones were repeatedly passaged in shake flasks for approximately
90
days to evaluate production stability. At each passage, cells were seeded in
125 ml shake
flasks at 1 x 105 viable cells/ml in 25 ml fresh medium. The cultures were
passaged every
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3-4 days. Before each passage, the cell density and viability were measured
and a sample
was taken for product concentration determination by Protein A HPLC.
Selected clones and subclones were cryopre served from the time of ranking by
pcd
values to various points in the stability evaluation. Freezing medium was
freshly made
with 90% growth medium and 10% DMSO (Sigma). Cells from shake flask cultures
were
centrifuged and resuspended in freezing medium at densities ranging from 2 -
10 x 106
cells/ml. The cell suspension was dispensed in 1 ml aliquots into cryogenic
vials. The
cryogenic vials were placed in an isopropanol freezing containers and stored
at ¨80 C
overnight. The frozen vials were transferred to liquid nitrogen vapor phase
storage the
following day.
Production of Mutant CTLA4-IgG2 Fusion Proteins.
A cryovial containing 1 ml volume of CHO-Kl cells expressing D3-54-IgG2
fusion protein is thawed and grown in 125 ml shake flasks containing CD
OptiCHOTm
medium at 37 C and 5% CO) to a density of 5 x 105 viable cells/ml. Several
flasks are
combined to inoculate a wave bag at 1-2 x 105 cells/ml in a 5 or 10 L volume
of CD
OptiCHOrm medium with 4 mM glutamine. The wave bag culture is maintained in a
37 C
incubator supplemented with 5% CO, at a rocking platform setting of 18-22 rpm
and angle
of 8 degrees for equipment purchased from Sartorius Stedim Biotech. The
culture is
sampled daily for cell count, viability, nutrient level, metabolite profile
and expression
level of the mutant CTLA-4-IgG2 (i.e., D3-54-IgG2) using a Protein A HPLC
assay. The
culture is harvested when the viability declines to ¨50% typically 9-11 days
post
inoculation. The cell culture material is clarified by filtration using a
combination of
depth filtration and sterile filtration and either used immediately for
further processing or
stored at 2-8 C.
Purification of Mutant CTLA-4-IgG2 Fusion Proteins.
Mutant CTLA4-IgG2 fusion proteins (D3-54-IgG2) were purified by Protein-A
affinity chromatography using an AKTA Explorer HPLC system (GE Healthcare). A
mutant CTLA-4-Ig fusion protein (D3-54-IgG2) was bound to MabSelect Protein A
FF
columns (GE Healthcare, #17-5079-01) in PBS buffer (Invitrogen), loaded at
¨10mg/m1 of
chromatography media, washed with the same buffer, eluted with 100 mM citric
acid
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buffer (pH 4.0), and then neutralized by addition of 1/10 volume of 2M Tris
base. The
Protein A purified sample is further processed by diafiltration using a
tangential flow
filtration (TFF) system with a buffer exchange into 20mM Tris-C1, pH 7.5.
The buffer exchanged protein sample is further purified by anion exchange
chromatography on a Q-Sepharose column loaded at ¨10mg/rn1 loading density.
The
bound protein is eluted using a 20 column volume (CV) linear NaC1 gradient
from 0-
500mM NaC1 in 20 mM Tris-C1, pH 7.5. Major peak fractions are pooled and the
concentration is determined by measuring absorbance at 280 nm.
The protein purity is confirmed by SDS-PAGE analysis and the monomer content
is determined using a size exclusion-HPLC method. Samples are stored in
aliquots at 2-
8 C or at -20 C for extended periods prior to use.
While the foregoing invention has been described in some detail for purposes
of
clarity and understanding, it will be clear to one skilled in the art from a
reading of this
disclosure that various changes in form and detail can be made without
departing from the
true scope of the invention. It is understood that the materials, examples,
and
embodiments described herein are for illustrative purposes only and not
intended to be
limiting and that various modifications or changes in light thereof will be
suggested to
persons skilled in the art and are to be included within the spirit and
purview of this
application and scope of the appended claims. All publications, patent
applications,
patents, or other documents mentioned herein are incorporated by reference in
their
entirety for all purposes to the same extent as if each such individual
publication, patent,
patent application or other document were individually specifically indicated
to be
incorporated by reference herein in its entirety for all purposes and were set
forth in its
entirety herein. In case of conflict, the present specification, including
definitions, will
control.
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SEQUENCE LISTING IN ELECTRONIC FORM
In accordance with Section 111(1) of the Patent Rules, this description
contains a sequence listing in electronic form in ASCII text format
(file: 79735-11 Seq 12-APR-10 vl.txt).
A copy of the sequence listing in electronic form is available from the
Canadian Intellectual Property Office.
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