U.S. patent application number 17/212165 was filed with the patent office on 2021-10-07 for anti hla-g specific antibodies.
The applicant listed for this patent is Invectys SA. Invention is credited to Julien CAUMARTIN, Thierry HUET, Pierre LANGLADE DEMOYEN, Maria LOUSTAU, Maria WEHBE.
Application Number | 20210309748 17/212165 |
Document ID | / |
Family ID | 1000005669665 |
Filed Date | 2021-10-07 |
United States Patent
Application |
20210309748 |
Kind Code |
A1 |
LANGLADE DEMOYEN; Pierre ;
et al. |
October 7, 2021 |
ANTI HLA-G SPECIFIC ANTIBODIES
Abstract
The present invention relates to antibodies, or antigen-binding
fragments thereof, directed against human leukocyte antigen-G
(HLA-G) protein and raised against an immunogenic peptide derived
from the .alpha.3 domain of HLA-G protein. The invention further
relates to the immunogenic peptide, and methods for producing said
anti-HLA-G specific antibodies.
Inventors: |
LANGLADE DEMOYEN; Pierre;
(Neuilly-sur-Seine, FR) ; HUET; Thierry; (Nogent
sur Marne, FR) ; CAUMARTIN; Julien; (Le Vesinet,
FR) ; LOUSTAU; Maria; (Paris, FR) ; WEHBE;
Maria; (Montigny-le-Bretonneux, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Invectys SA |
Paris |
|
FR |
|
|
Family ID: |
1000005669665 |
Appl. No.: |
17/212165 |
Filed: |
March 25, 2021 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16306267 |
Nov 30, 2018 |
|
|
|
PCT/EP2017/063503 |
Jun 2, 2017 |
|
|
|
17212165 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07K 7/50 20130101; A61P
35/00 20180101; C07K 2317/33 20130101; C07K 2317/34 20130101; C07K
2317/76 20130101; C07K 2317/92 20130101; C07K 2317/622 20130101;
C07K 16/2833 20130101; C07K 7/08 20130101; A61P 31/12 20180101 |
International
Class: |
C07K 16/28 20060101
C07K016/28; C07K 7/08 20060101 C07K007/08; A61P 31/12 20060101
A61P031/12; A61P 35/00 20060101 A61P035/00; C07K 7/50 20060101
C07K007/50 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 3, 2016 |
EP |
16305650.0 |
Claims
1.-5. (canceled)
6. An anti-HLA-G antibody or an antigen-binding fragment thereof,
wherein the antibody or antigen-binding fragment comprises: (a) a
heavy chain variable region (VH), which comprises a heavy chain
complementary determining region 1 (HC CDR1) of SEQ ID NO: 23, a
heavy chain complementary determining region 2 (HC CDR2) of SEQ ID
NO: 25, and a heavy chain complementary determining region 3 (HC
CDR3) of SEQ ID NO: 27; and (b) a light chain variable region (VL),
which comprises a light chain complementary determining region 1
(LC CDR1) of SEQ ID NO: 15, a light chain complementary determining
region 2 (LC CDR2) of sequence KVS and a light chain complementary
determining region 3 (LC CDR3) of SEQ ID NO: 18.
7. The antibody or antigen-binding fragment of claim 6, wherein the
VH comprises SEQ ID NO: 67 and the VL comprises SEQ ID NO: 65.
8. The antibody or antigen-binding fragment of claim 6, wherein the
antibody or antigen-binding fragment is chimeric or humanized.
9. A nucleic acid comprising a nucleotide sequence encoding an
antibody heavy chain variable region (VH), an antibody light chain
variable region (VL) or both, of the antibody or antigen-binding
fragment of claim 1.
10. A vector, comprising the nucleic acid of claim 9.
11. A host cell comprising the vector of claim 10.
12. A method for producing an anti-HLA-G monoclonal antibody,
comprising culturing the host cell of claim 11 under conditions
allowing for expression of the antibody.
13. A conjugate comprising the antibody or antigen-binding fragment
of claim 1, linked to a cytotoxic agent.
14. A method for treating a cancer or a viral infection, the method
comprising administering to the subject the antibody or
antigen-binding fragment of claim 1.
15. (canceled)
16. (canceled)
17. The antigen-binding fragment of claim 1, wherein the
antigen-binding fragment is a Fv, a dsFv, a scFv, a Fab, a Fab', or
a F(ab').sub.2.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/306,267, filed on Nov. 30, 2018, which is a
U.S. National Phase of International Patent Application filed under
35 U.S.C. 371, of PCT/EP2017/063503, filed Jun. 2, 2017, which
claims priority to EP Patent Application No. 16305650.0, filed on
Jun. 3, 2016, all of which are herein incorporated by reference in
their entirety.
[0002] The present invention relates to antibodies, or
antigen-binding fragments thereof, raised against an immunogenic
peptide derived from the .alpha.3 domain of human leukocyte antigen
G (HLA-G) protein.
INCORPORATION OF THE SEQUENCE LISTING
[0003] The instant application contains a sequence listing of the
text file submitted electronically herewith and is hereby
incorporated by reference in its entirety: a computer readable
format copy of the Sequence Listing (filename:
INVE_001_02US_SeqList_ST25.txt, date recorded Mar. 25, 2021, file
size 45,281 bytes).
TECHNICAL BACKGROUND
[0004] In cancer, one major immune escape mechanism is the
expression of inhibitory molecules on the cell surface impairing T
cell signaling. Many of these inhibitory molecules are considered
as Immune Check Points (ICP) and refer to numerous inhibitory
pathways first demonstrated to maintain self-tolerance and to
modulate the duration and amplitude of physiological immune
responses within peripheral tissues to avoid collateral tissue
damages.
[0005] HLA-G was recently identified as an ICP molecule, which
inhibits the effector functions of infiltrating immune cell subsets
through the interaction with its specific receptors and is
frequently upregulated in tumor cells (Carosella et al., 2015).
[0006] Furthermore, HLA-G can also be neo-expressed and/or
up-regulated in pathological conditions such as viral infections,
auto-immune and inflammatory diseases or after
allo-transplantation. For instance, viruses such as HCMV (Human
Cytomegalovirus), HSV-1 (Herpes Virus Simplex), RABV (Rabies
Virus), HCV (hepatitis C Virus), IAV (Influenza A Virus) and HIV-1
(Human Immunodeficiency Virus type I) seem to up-regulate the
expression of HLA-G to prevent infected cells from being recognized
and attacked by CTL and NK cells. HLA-G can also control the CD8 T
cell response against HIV-infected cells by directing CD8 cells to
apoptosis and by affecting their cytotoxic properties (Tripathi and
Agrawal, 2007).
[0007] HLA-G is a non-classical MHC class I molecule that was first
identified in choriocarcinoma cells. MHC class I antigens comprise
the classical antigens HLA-A, HLA-B and HLA-C, which exhibit three
extracellular globular domains (.alpha..sub.1, .alpha..sub.2 and
.alpha..sub.3) associated with .beta.2-microglobulin (.beta.2M), as
well as the non-classical antigens HLA-E, HLA-F and HLA-G.
[0008] Unlike classical MHC class I molecules, HLA-G is
characterized by (i) a limited polymorphism, (ii) a
tissue-restricted expression, and (iii) differs as well by its
functions.
[0009] The eight exon gene coding for HLA-G molecules spans 4.4 kb
on chromosome 6 (Geraghty et al., 1987; Ellis et al., 1990). Exons
2, 3 and 4 encode the .alpha..sub.1, .alpha..sub.2 and
.alpha..sub.3 extracellular domains, respectively. The primary RNA
transcript can be alternatively spliced, resulting in the
expression of seven isoforms, four of which are membrane-bound
(HLA-G1, HLA-G2, HLA-G3 and HLA-G4), and three are soluble (HLA-G5,
HLA-G6 and HLA-G7). HLA-G1 and HLA-G5 are the most prominent
isoforms described, in part likely because of limited HLA-G
reagents such as antibodies. Their structures are typical of
classical HLA class I molecule: a heavy chain composed of three
extracellular globular domains non-covalently associated to
.beta.2-Microglobulin (.beta.2M) and a peptide, while the other
isoforms are shorter, lacking one or two globular domains of the
heavy chain, and without .beta.2M association.
[0010] The immuno-inhibitory activity of HLA-G takes place through
specific binding to three inhibitory receptors: leukocyte
immunoglobulin-like receptor B1 (LILRB1/ILT2/CD85j), LILRB2
(ILT4/CD85d) and KIR2DL4 (or CD158d).
[0011] Through the interaction with these receptors, and opposite
to classical MHC class I molecules, HLA-G acts as a down-regulator
of the immune system's main functions, and neither stimulatory
functions nor responses directed against allogenic HLA-G have been
reported to date (Carosella et al., 2008a).
[0012] In a similar manner to other MHC class I molecules, LILRB
receptors interact with the .alpha.3 domain of HLA-G. The LILRB1
receptor is expressed on B cells, some T cells, some NK cells and
on all APCs (monocytes and dendritic cells), whereas LILRB2
expression is restricted to the myeloid lineage and only expressed
on monocytes and dendritic cells.
[0013] LILRB1 and LILRB2 receptors bind a wide range of classical
MHC molecules through the .alpha.3 domain/.beta.2M complex or only
the .alpha.3 domain respectively. Indeed, LILRB1 binds only
.beta.2M-associated HLA-G complexes, whereas LILRB2 recognizes both
.beta.2M-associated and .beta.2M-free HLA-G molecules as well as
truncated .alpha.1-.alpha.3 domain isoforms.
[0014] HLA-G is the ligand of highest affinity for LILRB2 receptor
as compared to classical MHC class I molecules. The higher affinity
of HLA-G for LILRB1 and LILRB2 receptors is particularly
illustrated by the fact that HLA-G displayed at the surface of
tumor cells is capable of engaging the LILRB1 and/or LILRB2
receptors even if classical MHC class I molecules are also
expressed at their surface. This preferential interaction of HLA-G
for LILRB receptors is sufficient to inhibit the cytolytic
functions of immune effector cells.
[0015] LILRB1 and 2 receptors do not bind the same HLA-G forms and
present a higher affinity for HLA-G multimers than monomeric
structures (HoWangYin et al., 2012). This higher affinity of LIRB
receptors for HLA-G was demonstrated to be related to the presence
of aromatic amino acids Phe195 and Tyr197 within the .alpha.3
domain of HLA-G that are not present in classical MHC class I
molecules.
[0016] The relevance of HLA-G expression as an escape mechanism
employed by tumor cells to inhibit effector cells has been widely
demonstrated (Loustau et al., 2013). Several approaches targeting
HLA-G with the goal of mediating tumor cell rejection have been
developed (Carosella et al., 2008b; Yan, 2011). Few anti-HLA-G
antibodies have been generated, and only one blocking antibody is
available (87G) (Blaschitz et al., 2000; Menier et al., 2003). This
monoclonal antibody, 87G, interacts with the .alpha.1 domain of the
heavy chain of HLA-G associated to .beta.2M. Even though it has
been described as capable of neutralizing HLA-G, and therefore
restoring tumor rejection in vitro and in vivo (Agaugue et al.,
2011), its applicability is compromised as HLA-G is frequently
expressed as a .beta.2M-free full length molecule or truncated
isoforms. These various isoforms can also bind the LILRB2
inhibitory receptor.
[0017] HLA-G immunization has been remarkably difficult, yielding
few specific antibodies. The reasons for this failure to generate
neutralizing antibodies have been elucidated. In
kidney-transplanted patients, it was demonstrated that the presence
of HLA-G does not favor antibody production (Qiu et al., 2006).
Recent in vitro studies have confirmed that HLA-G/LILRB1
interaction impairs B-cell maturation and antibody production in
humans (Naji et al., 2014). HLA-G is also known to exert a
tolerogenic function in mice, a species commonly used to generate
monoclonal antibodies (Favier et al., 2001). HLA-G interacts with
the PIR-B receptor, which is expressed in murine B-cells and which
is functionally homologous to human LILRB1 and LILRB2 (Liang et
al., 2002). HLA-G/PIR-B interaction would lead to B-cell inhibition
thus preventing antibody production in mice.
[0018] A monoclonal antibody apparently directed to the .alpha.3
domain of classical MHC class I molecules, named TP25.99 has been
developed (Tanabe et al., 1992). However, others have shown that it
does not bind the .alpha.3 domain of HLA-G (Desai et al., 2000; Moy
et al., 2000). This discrepancy could be explained by the
hydrophobic characteristic of HLA-G .alpha.3 domain that is
unfavorable to antibody generation.
[0019] While the international patent application WO2014/072534
proposes a method for generating and developing anti-HLA-G
antibodies by DNA immunization with the complete .alpha.3 domain of
HLA-G, there is still a need for anti-HLA-G antibodies which
recognize all HLA-G isoforms and exhibit an improved specificity
with respect to HLA-G.
SUMMARY OF THE INVENTION
[0020] The inventors have now succeeded in circumventing the
difficulties for generating specific anti-HLA-G antibodies, by
designing an immunogenic peptide from the .alpha.3 domain of HLA-G
protein.
[0021] The first object of the invention is an isolated peptide
consisting of sequence X1-THHPVFDYEATLR-X2 (SEQ ID NO: 49), wherein
X1 is absent, Cysteine, Valine, or is a sequence selected from the
group consisting of KTHV (SEQ ID NO: 50) or CKTHV (SEQ ID NO: 51),
and X2 is absent or Cysteine.
[0022] Such a peptide is useful as an immunogen for producing
antibodies specific for the .alpha.3 domain of HLA-G protein
isoforms, preferably monoclonal antibodies.
[0023] A further object of the invention is an anti-HLA-G antibody,
preferably a monoclonal antibody, which specifically recognizes the
peptide as defined herein.
[0024] The antibody may be a full-length antibody, an
antigen-binding fragment thereof, or a bispecific antibody.
[0025] A further object of the invention is a composition
comprising such antibody and a pharmaceutically acceptable
carrier.
[0026] Another subject of the invention is a nucleic acid
comprising a nucleotide sequence encoding an antibody heavy chain
variable region (VH), an antibody light chain variable region (VL)
or both, of the antibody as defined herein.
[0027] A vector, preferably an expression vector, comprising said
nucleic acid is also provided.
[0028] A host cell comprising the nucleic acid or the vector is
further described.
[0029] Methods for producing anti-HLA-G antibodies are further
provided. In a preferred embodiment is disclosed a method for
producing an anti-HLA-G monoclonal antibody, comprising culturing
the host cell comprising said nucleic acid or said vector under
conditions allowing for expression of the antibody.
[0030] The antibody, nucleic acid or vector expressing said
antibody, is particularly useful in treating a cancer or a viral
infection.
[0031] A further subject of the invention is the use of the
anti-HLA-G antibody described herein, in an in vitro diagnostic
method for detecting or monitoring HLA-G in a biological
sample.
[0032] Diagnostic kits comprising said antibody are further
encompassed.
FIGURE LEGENDS
[0033] FIG. 1A-FIG. 1C. Design of the immunogen, immunization and
generation of anti-HLA-G antibodies. FIG. 1A. Amino acid sequence
alignment of human HLA-G protein with HLA-E, A2, B7, B44, and CW3.
The sequence alignment is provided for the three immunoglobulin
domains of HLA-G: .alpha.1, .alpha.2, and .alpha.3. Residues
highlighted in gray represent the differences with HLA-G. The
regions in the .alpha.3 domain involved in LILRB1/2 binding are
highlighted with black double-headed arrows. Amino acid sequence of
the HLA-G specific PC-1 peptide is underlined and shown in bold.
FIG. 1B. Generation of anti-HLA-G antibodies in immunized mice.
Representative flow cytometric histograms of anti-HLA-G serum
reactivity from an immunized BALB/c mouse (dark black lines/dark
gray histograms) and from a non-immunized control mouse (light gray
lines and histograms). Dashed lines denote the threshold above
which signals are considered positive. Sera were prepared, diluted,
and incubated with HLA-G5-coated beads and then incubated with a
FITC-conjugated goat anti-mouse IgG secondary antibody.
Fluorescence was analyzed by flow cytometry. Four dilutions of
serum are shown. FIG. 1C. The reactivity of R4C-C3 (diamond
symbols/dotted line) and R5C-D8 (circle symbols/dashed line) scFv
antibodies to biotin-coupled PC1 peptide was assessed by ELISA.
ScFv antibodies were serially diluted and tested by direct ELISA
using biotin-PC1 coated on streptavidin microplates. Non-HLA-G
biotinylated peptide was used as control (square and triangle
symbols/thick lines).
[0034] FIG. 2A. Nucleotide and amino acid sequences of the .kappa.
light chain variable region of 15E7. The positions of
"Complementary Determining Regions" (CDR1, CDR2 and CDR3), as well
as those of "Framework Regions" (FR1, FR2, FR3 and FR4) of the
antibody are displayed. FIG. 2B. Sequence alignment of the amino
acid sequences of the .kappa. light chain variable region of 15E7
and the corresponding mouse germinal amino acid gene. The amino
acids in the sequence of 15E7 .kappa. light chain which are
different from the germline sequences are shown in bold. The
positions of CDRs are indicated.
[0035] FIG. 3A. Nucleotide and amino acid sequences of the heavy
chain variable region of 15E7. The positions of CDR1, CDR2 and CDR3
sequences, as well as those of FR of the antibody are displayed.
FIG. 3B. Sequence alignment of the amino acid sequences of the
heavy chain variable region of 15E7 and the corresponding mouse
germinal amino acid gene. The amino acids in the sequence of 15E7
heavy chain which are different from the germline sequences are
shown in bold. The positions of CDRs are indicated.
[0036] FIG. 4A. Nucleotide and amino acid sequences of the .kappa.
light chain variable region of the scFv R4C-C3. The positions of
CDR1, CDR2 and CDR3 sequences, as well as those of FR of the scFv
are displayed. FIG. 4B. Sequence alignment of the amino acid
sequences of the .kappa. light chain variable region of scFv R4C-C3
and the corresponding mouse germinal amino acid gene. The amino
acids in the sequence of the scFv R4C-C3 .kappa. light chain which
are different from the germline sequences are shown in bold. The
positions of CDRs are indicated.
[0037] FIG. 5A. Nucleotide and amino acid sequences of the heavy
chain variable regions of the scFv antibody R4C-C3. The positions
of CDR1, CDR2 and CDR3 sequences, as well as those of FR of the
scFv antibody are displayed. FIG. 5B. Sequence alignment of the
amino acid sequences of the heavy chain variable regions of scFv
antibody R4C-C3 and the corresponding mouse germinal amino acid
gene. The amino acids in the sequence of the scFv antibody R4C-C3
heavy chain that are different from the germline sequences are
shown in bold. The positions of CDRs are displayed.
[0038] FIG. 6A. SDS-PAGE analysis of 15E7 monoclonal antibody. Lane
1: molecular weight markers--sequentially from top to down, 75 kDa,
50 kDa, 37 kDa, 25 kDa and 20 kDa. Lane 2: mouse IgG as control.
Lane 3: 15E7 monoclonal antibody. Proteins were separated by
SDS-PAGE and colored with Coomassie brilliant blue FIG. 6B. Kinetic
analysis of the binding of the 15E7 monoclonal antibody to the PC-1
peptide using the Blitz biolayer interferometry system. The 15E7
monoclonal antibody was immobilized to AR2G chips by amino
coupling. Various concentrations of PC-1 peptide/BSA (from 5 to 600
nM) were incubated with 15E7 coupled to the biosensor surface.
Analysis started at time point 30 seconds for a duration of 120
seconds (association phase) after which only buffer was incubated
for 100 seconds to record the dissociation of PC-1/BSA from 15E7.
Left side of the dotted line (at 150 seconds) shows the association
kinetics, whereas the right side indicates the dissociation phase.
The upper line corresponds to the binding of 15E7 to the highest
concentration of peptide (600 nM) and the lower line to the lowest
concentration of peptide (5 nM). The binding was proportional to
the peptide concentration (intermediate lines).
[0039] FIG. 7A-FIG. 7C. Dose dependent binding of the monoclonal
antibody 15E7 to its targets: cPC-1 peptide (FIG. 7A); HLA-G5
recombinant protein (FIG. 7B) or HLA-G6 recombinant protein (both
proteins without .beta.2M association) (FIG. 7C). Various serial
concentrations of 15E7 were used to determine a dose-dependent
binding activity. The binding detection was carried out by flow
cytometry using a PE-conjugated goat anti-mouse antibody. Binding
is represented as a percentage of positive labeled beads with 15E7
compare to the staining with the isotype control (IgG2a). EC.sub.50
of 15E7 was evaluated at 2 ng/mL on cPC-1 peptide, at 28 ng/mL on
HLA-G5 and at 120 ng/mL on HLA-G6 proteins. Measurements were
performed in triplicate (n=3); error bars indicate SD. Dark lines
represent the binding of 15E7 to ligands coated beads while gray
lines represent the binding of 15E7 to control beads [beads coated
with a mutated peptide (FIG. 7A) or uncoupled beads (FIG. 7B and
FIG. 7C)].
[0040] FIG. 8. Dose dependent binding of the anti-HLA-G monoclonal
antibody 15E7 to .beta.2M-free HLA-G1 expressed on K562 cell
surface. Various concentrations (0-80 .mu.g/mL) of 15E7 were used
to determine the specific dose-dependent binding activity of 15E7
on HLA-G1 positive cells (K562-G1) vs. HLA-G negative control cells
(K562-PV). The detection of 15E7 was carried out by flow cytometry
using a PE-conjugated goat anti-mouse antibody. 15E7 exhibits a
dose-dependent binding on the target K562-G1 cells (black line),
whereas no binding was detected on the control cell line K562-PV
(gray line).
[0041] FIG. 9A-FIG. 9C. Flow cytometry analysis of surface HLA-G
antigens on untreated or acid-treated K562-G1 and K562-PV cells
(FIG. 9A, FIG. 9B) and JEG-3 cells (FIG. 9C). Surface HLA-G
antigens were analyzed by following mAbs: MEM-G/9 (specific to
native HLA-G complex), anti-h.beta.2M and 15E7. Histograms: light
gray: Unstained; gray: isotype controls (IgM for the anti-NM, IgG2a
for the 15E7 mAb and IgG1 for the 4H84); dark gray; indicated
antibody.
[0042] FIG. 10. The 15E7 monoclonal antibody binds specifically to
HLA-G and not to classical MHC class I molecules. These binding
assays assessing the specificity of 15E7 were performed using
lymphoma cell lines (LCL DES, LCL BRO and RPMI8866) expressing
human classical MHC class I molecules at their surface but not
HLA-G, and analyzed by flow cytometry. 15E7 was used at a final
concentration of 20 .mu.g/mL. Binding is represented as a
percentage of positive stained cells with 15E7 in comparison to the
isotype control (IgG2a). K562-G1 and K562-PV cells were used as
positive and negative controls, respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0043] HLA-G therapeutic and diagnostic antibodies are lacking due
to HLA-G tolerogenic functions on B cell maturation and antibody
secretion. The inventors managed to bypass this inhibition by using
a peptide derived from the HLA-G-.alpha.3 domain, which was able to
induce anti-HLA-G specific antibodies.
[0044] The present invention provides anti-HLA-G monoclonal
antibodies that bind specifically to HLA-G and which exhibit many
desirable characteristics. Indeed, the anti-HLA-G antibodies
generated strongly bind to either recombinant or endogenous HLA-G
proteins in absence of cross-reactivity with classical MHC class I
molecules.
[0045] The invention also relates to the use of such antibodies in
order to restore the immune system resulting from pathological
expression of HLA-G on the surface of some of the patient's cells.
Accordingly, the antibodies are suitable for use in order to treat
or alleviate a condition diagnosed in patients, when said condition
takes advantage of the down-regulation of the immune system in a
patient, due to the presence of HLA-G proteins. Antibodies of the
invention may also be used for diagnostic or monitoring a condition
in a patient.
Definitions
[0046] An antibody "specifically binds" to a target antigen if it
binds with greater affinity, avidity, more readily, and/or with
greater duration than it binds to other substances. "Specific
binding" or "preferential binding" does not necessarily require
(although it can include) exclusive binding. Generally, but not
necessarily, reference to binding means preferential binding. The
affinity of the binding is defined by association and dissociation
rate constants, or K.sub.D (equilibrium dissociation). Typically,
specifically binding when used with respect to an antibody refers
to an antibody that specifically binds to ("recognizes") its
target(s) with an affinity (K.sub.D) value less than 10.sup.-8M,
e.g., less than 10.sup.-9M or 10.sup.-10 M. A lower K.sub.D value
represents a higher binding affinity (i.e., stronger binding) so
that a K.sub.D value of 10.sup.-9M indicates a higher binding
affinity than a K.sub.D value of 10.sup.-8M.
[0047] Within the context of the present invention, "HLA-G protein
binding" by antibodies or antigen-binding fragments of the
invention means that the antibodies or antigen-binding fragments of
the invention recognize HLA-G protein isoforms exhibiting .alpha.3
domain or found associated with an .alpha.3 domain, while being
further found associated or not associated with
.beta.2-microglobulin protein or fragment thereof.
[0048] By "associated", it is meant a close (non-covalent)
interaction between the considered domains or domains and proteins.
Such an interaction can be achieved by the formation of hydrogen
bonds, or van der Waals interactions, or ionic bonds.
[0049] By "specific binding" properties of the antibodies of the
invention or antigen-binding fragments thereof it is meant that the
antibodies or antigen-binding fragments thereof directly bind to
the .alpha.3 domain of HLA-G protein to the exclusion of other
domains of the HLA-G protein or to the exclusion of binding to
other human proteins, in particular to the exclusion of binding to
other HLA proteins. The binding capacity may be measured by
determination of the binding affinity for the .alpha.3 domain of
HLA-G protein, according to conventional tests known in the art of
the invention, in particular the binding affinity can be assayed by
ELISA, or Western Blot analysis. According to a specific
embodiment, "specific binding" means that the interaction between
the antibodies or antigen-binding fragments of the invention and
the .alpha.3 domain of HLA-G protein through such a specific
binding is more stable than interaction between the antibodies or
antigen-binding fragments of the invention and other human
proteins, or other HLA-G domains or other HLA proteins. Stability
can be appreciated by comparing the persistence over time, or under
competition conditions, of the antigen-antibody complex and, in
particular, by measuring the dissociation constant of the
antibodies recognizing the .alpha.3 domain of the HLA-G
protein.
[0050] A "blocking antibody" is an antibody that inhibits the
interaction of HLA-G proteins with any or all of its receptors,
e.g. LILRB1 receptor and/or LILRB2 receptor. Therefore, by
"blocking", it is typically meant that the biological function
subsequent to binding between HLA-G proteins through an .alpha.3
domain and their receptors is abolished or strongly diminished in
the presence of antibodies or antigen-binding fragments of the
invention. The biological function referred to in this context is
the immuno-inhibitory activity of HLA-G proteins exhibiting an
.alpha.3 domain, as disclosed herein and assessed in the
literature. Accordingly, it can be said that the antibodies or
antigen-binding fragments are antagonist agents of HLA-G proteins,
or antagonist agents of the effect(s) of HLA-G proteins having an
.alpha.3 domain, because interfering with the activity of such
HLA-G proteins and/or opposing to its activity at least in part or
completely, directly or indirectly. Preferably the decrease in the
interaction, i.e. binding, with any or all HLA-G receptors, is at
least 20%, more preferably at least 30%, more preferably at least
40%, more preferably at least 50%, more preferably at least 60%,
more preferably at least 70%, more preferably at least 80%, more
preferably at least 90%, and most preferably 100%. Activity may be
measured by binding assays known in the art.
[0051] The terms "Kabat numbering", "Kabat definitions and "Kabat
labeling" are used interchangeably herein. These terms, which are
recognized in the art, refer to a system of numbering amino acid
residues that are more variable (i.e., hypervariable) than other
amino acid residues in the heavy and light chain variable regions
of an antibody, or an antigen binding portion thereof (Kabat et al.
1971; Kabat, et al. 1991).
[0052] As used herein, the term "CDR" refers to the Complementarity
Determining Region within antibody variable sequences. There are
three CDRs in each of the variable regions of the heavy chain and
the light chain, which are designated CDR1, CDR2 and CDR3, for each
of the variable regions. The term "CDR set" as used herein refers
to a group of three CDRs that occur in a single variable region
capable of binding the antigen. The exact boundaries of these CDRs
have been defined differently according to different systems. The
system described by Kabat (Kabat et al., Sequences of Proteins of
Immunological Interest (National Institutes of Health, Bethesda,
Md. (1987) and (1991)) not only provides an unambiguous residue
numbering system applicable to any variable region of an antibody,
but also provides precise residue boundaries defining the three
CDRs. These CDRs may be referred to as Kabat CDRs. Chothia and
coworkers (Chothia et al, 1987 and Chothia et al., 1989) found that
certain sub-portions within Kabat CDRs adopt nearly identical
peptide backbone conformations, despite having great diversity at
the level of amino acid sequence.
[0053] By "antigen-binding fragment" of an antibody of the
invention, it is meant a part of an antibody, i.e. a molecule
corresponding to a portion of the structure of the antibody of the
invention that exhibits antigen-binding capacity for the .alpha.3
domain of HLA-G proteins. In a particular embodiment, said fragment
exhibits substantially the same antigen-binding capacity for said
domain as the antigen-binding capacity of the antibody having a
full antibody structure. The antigen-binding capacity can be
determined by measuring the affinity of the antibody and of the
considered antigen-binding fragment to the targeted antigen.
[0054] Antigen-binding fragments of antibodies encompass fragments
which comprise the hypervariable domains designated CDRs or part(s)
thereof encompassing the recognition site for the immunogenic
peptide. Each Light and Heavy chain (respectively VL and VH) of a
four-chain immunoglobulin has three CDRs, designated VL-CDR1,
VL-CDR2, VL-CDR3 and VH-CDR1, VH-CDR2, VH-CDR3, respectively. Thus
the invention relates to fragments of antibodies of the invention
(antigen-binding fragments), which comprise or consist in all or a
selection of CDRs among VL-CDR1, VL-CDR2, VL-CDR3 and VH-CDR1,
VH-CDR2 and VH-CDR3 or functional portions thereof, i.e. portions
that exhibit the desired binding capacity, preferably with a high
affinity, for the .alpha.3 domain of HLA-G proteins.
[0055] The term "monoclonal antibody" refers to an antibody that is
derived from a single clone, including any eukaryotic, prokaryotic,
or phage clone, and not the method by which it is produced. It is
thus not limited to antibodies produced through hybridoma
technology.
[0056] By "polyclonal serum" it is meant a serum comprising a
heterogeneous population of many different antibodies or fragments
thereof raised against a specific antigen, which are therefore
specific for a number of distinct antigenic determinants found on
said specific antigen.
[0057] As used herein, a "chimeric antibody" refers to an antibody
in which a portion of the heavy and/or light chain is identical
with or homologous to corresponding sequences in antibodies derived
from a particular species or belonging to a particular antibody
class or subclass, while the remainder of the chain(s) is(are)
identical with or homologous to corresponding sequences in
antibodies derived from another species or belonging to another
antibody class or subclass, as well as fragments of such
antibodies, as long as they exhibit the desired biological activity
As used herein, "humanized antibody" is a subset of "chimeric
antibodies."
[0058] "Humanized" forms of non-human (e.g., murine) antibodies are
chimeric antibodies that contain minimal sequence derived from
non-human immunoglobulin. In one embodiment, a humanized antibody
is a human immunoglobulin (recipient antibody) in which residues
from a hypervariable region (HVR) of the recipient are replaced by
residues from of an HVR of a non-human species (donor antibody)
such as mouse, rat, rabbit or non-human primate having the desired
specificity, affinity, and/or capacity for its targets. In some
instances, residues of Complementarity-Determining Regions of the
human immunoglobulin are replaced by corresponding non-human
residues. Furthermore, humanized antibodies may comprise residues
that are not found in the recipient antibody or in the donor
antibody. These modifications may be made to further refine
antibody performance, such as binding affinity. In general, a
humanized antibody will comprise substantially all of at least one,
and typically two, variable domains, in which all or substantially
all of the hypervariable loops correspond to those of a non-human
immunoglobulin sequence, and all or substantially all of the
framework regions (FR) are those of a human immunoglobulin
sequence, although the FR regions may include one or more
individual FR residue substitutions that improve antibody
performance, such as binding affinity, isomerization,
immunogenicity, and the like. The number of these amino acid
substitutions in the FR is typically no more than 6 in the H chain,
and no more than 3 in the L chain. The humanized antibody
optionally will also comprise at least a portion of an
immunoglobulin constant region (Fc), typically that of a human
immunoglobulin.
[0059] A "human antibody" is one that possesses an amino-acid
sequence corresponding to that of an antibody produced by a human
and/or has been made using any of the techniques for making human
antibodies known in the art, including phage-display libraries.
This definition of a human antibody specifically excludes a
humanized antibody comprising non-human antigen-binding
residues.
[0060] The "percent identity" of two amino acid sequences may be
determined using the algorithm of Karlin and Altschul, 1990, as
modified in Karlin and Altschul, 1993. Such an algorithm is
incorporated into the NBLAST and XBLAST programs (version 2.0) of
Altschul, et al. 1990. BLAST protein searches can be performed with
the XBLAST program, score=50, wordlength=3 to obtain amino acid
sequences homologous to the protein molecules of interest. Where
gaps exist between two sequences, Gapped BLAST can be utilized as
described in Altschul et al., 1997. When utilizing BLAST and Gapped
BLAST programs, the default parameters of the respective programs
(e.g., XBLAST and NBLAST) can be used.
[0061] "Conservative substitutions" will produce molecules having
functional and chemical characteristics similar to those of the
molecule from which such modifications are made. For example, a
"conservative amino acid substitution" may involve a substitution
of an amino acid residue with another residue such that there is
little or no effect on the polarity or charge of the amino acid
residue at that position. Desired amino acid substitutions (whether
conservative or non-conservative) can be determined by those
skilled in the art. For example, amino acid substitutions can be
used to identify important residues of the molecule sequence, or to
increase or decrease the affinity of the molecules described
herein. Variants comprising one or more conservative amino acid
substitutions can be prepared according to methods for altering
polypeptide sequence known to one of ordinary skill in the art such
as are found in references which compile such methods, e.g.
Molecular Cloning: A Laboratory Manual, J. Sambrook, et al., eds.,
Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring
Harbor, N.Y., 1989, or Current Protocols in Molecular Biology, F.
M. Ausubel, et al., eds., John Wiley & Sons, Inc., New York.
Conservative substitutions of amino acids include substitutions
made amongst amino acids within the following groups: (a) M, I, L,
V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g)
E, D.
[0062] The terms "subject," "individual," and "patient" are used
interchangeably herein and refer to a mammal being assessed for
treatment and/or being treated. Subjects may be human, but also
include other mammals, particularly those mammals useful as
laboratory models for human disease, e.g. mouse, rat, rabbit, dog,
etc.
[0063] The term "treatment" or "treating" refers to an action,
application or therapy, wherein a subject, including a human being,
is subjected to medical aid with the purpose of improving the
subject's condition, directly or indirectly. Particularly, the term
refers to reducing incidence, or alleviating symptoms, eliminating
recurrence, preventing recurrence, preventing incidence, improving
symptoms, improving prognosis or combination thereof in some
embodiments. The skilled artisan would understand that treatment
does not necessarily result in the complete absence or removal of
symptoms. For example, with respect to cancer, "treatment" or
"treating" may refer to slowing neoplastic or malignant cell
growth, proliferation, or metastasis, preventing or delaying the
development of neoplastic or malignant cell growth, proliferation,
or metastasis, or some combination thereof.
The Immunogenic Peptide
[0064] The inventors designed an immunogenic peptide to develop
anti-HLA-G antibodies specific for HLA-G with no cross-reactivity
toward classical MHC class I molecules.
[0065] HLA-G amino acid sequence differs from other MHC class I
molecules (HLA-E, A2, B7, B44 and CW3) as shown in FIG. 1A.
Variations in amino acids of the MHC class I sequences compare to
the sequence of HLA-G are highlighted in gray, showing many
hotspots within the different domains. Particularly, a highly
specific sequence for HLA-G was identified within the .alpha.3
domain at position 194-197. This portion of HLA-G .alpha.3 domain
encompasses amino acids essential for the interaction between HLA-G
and its receptors (FIG. 1A).
[0066] On this basis, the inventors have designed an immunogenic
peptide that consists of sequence X1-THHPVFDYEATLR-X2 (SEQ ID NO:
49), wherein X1 is absent, Cysteine, Valine, or is a sequence
selected from the group consisting of KTHV (SEQ ID NO: 50) or CKTHV
(SEQ ID NO: 51), and X2 is absent or Cysteine.
[0067] In a preferred embodiment, the peptide is circular and
consists of a sequence:
TABLE-US-00001 a. (SEQ ID NO: 52) CTHHPVFDYEATLRC, b. (SEQ ID NO:
53) CKTHVTHHPVFDYEATLRC,
wherein a disulfide bond links the N-term and C-term Cysteine
residues.
[0068] In another preferred embodiment, the peptide is linear and
consists of a sequence selected from the group consisting of:
TABLE-US-00002 (SEQ ID NO: 54) THHPVFDYEATLR; (SEQ ID NO: 55)
THHPVFDYEATLRC; (SEQ ID NO: 56) VTHHPVFDYEATLRC; (SEQ ID NO: 57)
VTHHPVFDYEATLR; (SEQ ID NO: 58) CTHHPVFDYEATLR; (SEQ ID NO: 59)
KTHVTHHPVFDYEATLR; (SEQ ID NO: 60) KTHVTHHPVFDYEATLRC and (SEQ ID
NO: 61) CKTHVTHHPVFDYEATLR.
[0069] The peptide may be produced by any technique known in the
art, e.g. chemical synthesis or by recombination.
[0070] It is also provided a nucleic acid that encodes said
peptide.
[0071] The invention also concerns a vector for the cloning and/or
for the expression of the nucleic acid, especially a plasmid
suitable for cloning and/or expressing in a host cell. According to
a particular embodiment, regulation sequences for transcription and
expression may be added. The recombinant expression vectors
typically contain a nucleic acid encoding the sequence to express,
operably linked to a promoter, either constitutive or inducible.
The vectors can be suitable for replication and integration in
prokaryotes, eukaryotes, or both. Typical vectors contain
transcription and translation terminators, initiation sequences,
and promoters useful for regulation of the expression of the
nucleic acid encoding said immunogenic peptide. The vectors
optionally contain generic expression cassettes containing at least
one independent terminator sequence, sequences permitting
replication of the cassette in both eukaryotes and prokaryotes,
i.e., shuttle vectors, and selection markers for both prokaryotic
and eukaryotic systems.
[0072] As described in greater details below, the immunogenic
peptide is useful for producing anti-HLA-G antibodies by
immunization.
The Anti-HLA G Antibodies
[0073] The present invention relates to an antibody or an
antigen-binding fragment thereof which specifically binds the
immunogenic peptide defined above.
[0074] The anti-HLA-G antibodies of the invention all recognize the
.alpha.3 domain of HLA-G proteins. In a specific embodiment, the
antibody or antigen-binding fragment thereof specifically binds the
.alpha.3 domain of HLA-G proteins having a conformation as
naturally found in cells expressing HLA-G. In other words, such an
antibody or antigen-binding fragment thereof of the invention
recognizes a specific epitope of the .alpha.3 domain of HLA-G as
naturally found in cells expressing HLA-G.
[0075] It is a purpose of the invention to produce specific
anti-HLA-G antibodies for the HLA-G isoforms encompassing an
.alpha.3 domain, or recognizing HLA-G isoforms associated with an
.alpha.3 domain. Accordingly, when referring to binding to a HLA-G
protein, the invention especially relates to binding to a HLA-G
isoform that exhibits an .alpha.3 domain.
[0076] In a particular embodiment, it is provided antibodies, or
antigen-binding fragments thereof, which recognize the soluble
forms of HLA-G.
[0077] In another embodiment, it is provided antibodies, or
antigen-binding fragments thereof, which recognize the
membrane-anchored forms of HLA-G.
[0078] In a most preferred embodiment, the antibodies of the
present invention recognize the immunogenic peptide, either in
linear form or in circular form, as well as HLA-G protein in
soluble form and HLA-G protein at the cell surface (i.e. in natural
conformation).
[0079] As mentioned above, HLA-G protein can be found under several
structural (or three dimensional) forms, which are commonly called
isoforms. HLA-G1 and HLA-G5 are respectively membrane-bound or
secreted HLA-G proteins that are found associated or not with the
.beta.2-microglobulin protein. By contrast, HLA-G2, HLA-G3 and
HLA-G4 are membrane-bound HLA-G protein isoforms not exhibiting
concomitantly all of the .alpha.2 and .alpha.3 domains. HLA-G1
isoform can also be found as a dimeric form at the cell surface.
HLA-G6 and HLA-G7 are secreted HLA-G protein isoforms also not
exhibiting concomitantly all of the .alpha.2 and .alpha.3
domains.
[0080] Advantageously, the anti-HLA-G antibodies of the invention
recognize all isoforms of HLA-G exhibiting an .alpha.3 domain.
[0081] In a preferred embodiment, an antibody or an antigen-binding
fragment thereof of the invention binds at least one or several of
the HLA-G protein isoforms selected amongst: HLA-G1, HLA-G2, HLA-G5
and HLA-G6 (monomeric and dimeric isoforms).
[0082] In a particular embodiment, the anti-HLA-G antibodies of the
invention recognize HLA-G proteins, whether they are associated
with the .beta.2-microglobulin protein, or not.
[0083] The .beta.2-microglobulin protein which, in some cases, can
be found associated to HLA-G protein, is however not systematically
present in all isoforms of the HLA-G protein. As detailed above,
the presence of an associated .beta.2-microglobulin protein is also
not necessary to enable the binding of an HLA-G protein to the
LILRB2 inhibitory receptor.
[0084] Within the context of the invention, ".beta.2-microglobulin
free HLA-G protein" therefore relates to HLA-G protein that is not
associated with .beta.2-microglobulin protein. By
".beta.2-microglobulin free truncated HLA-G protein isoform" or
".beta.2-microglobulin free truncated HLA-G protein isoform
exhibiting an .alpha.3 domain", reference is made to an HLA-G
protein not exhibiting all the domains that may be found in an
HLA-G protein, and not associated with .beta.2-microglobulin
protein.
[0085] In a particular embodiment of the invention, the antibodies
or antigen-binding fragments thereof specifically bind the .alpha.3
domain when present in HLA-G, in particular in
.beta.2-microglobulin free HLA-G, i.e., the .beta.2-microglobulin
free HLA-G exhibiting an .alpha.3 domain or the
.beta.2-microglobulin free truncated HLA-G exhibiting an .alpha.3
domain.
[0086] In a particular embodiment, it is provided antibodies, or
antigen-binding fragments thereof, which bind the .alpha.3 domain
of HLA-G protein when this protein is under a monomeric or dimeric
form.
[0087] According to a particular embodiment, an antibody or an
antigen-binding fragment thereof of the invention both binds the
.alpha.3 domain of a HLA-G protein when said protein is under a
monomeric and/or a dimeric form, and binds the .alpha.3 domain when
present in a HLA-G protein, whether the .beta.2-microglobulin
protein is associated, or not associated.
[0088] For purposes of illustration of specific embodiments of the
invention, antigen-binding fragments of an antibody that contains
the variable domains comprising the CDRs of said antibody encompass
Fv, dsFv, scFv, Fab, Fab', F(ab')2 which are well defined with
reference to Kabat and also Roitt I. et al (Fundamental and Applied
Immunology MEDSI/McGraw-Hill). Fv fragments consist of the VL and
VH domains of an antibody associated together by hydrophobic
interactions; in dsFv fragments, the VH:VL heterodimer is
stabilized by a disulphide bond; in scFv fragments, the VL and VH
domains are connected to one another via a flexible peptide linker
thus forming a single-chain protein. Fab fragments are monomeric
fragments obtainable by papain digestion of an antibody; they
comprise the entire L chain, and a VH-CH1 fragment of the H chain,
bound together through a disulfide bond. The F(ab')2 fragment can
be produced by pepsin digestion of an antibody below the hinge
disulfide; it comprises two Fab' fragments, and additionally a
portion of the hinge region of the immunoglobulin molecule. The
Fab' fragments are obtainable from F(ab')2 fragments by cutting a
disulfide bond in the hinge region. F(ab')2 fragments are divalent,
i.e. they comprise two antigen-binding sites, like the native
immunoglobulin molecule; on the other hand, Fv (a VH-VL dimer
constituting the variable part of Fab), dsFv, scFv, Fab, and Fab'
fragments are monovalent, i.e. they comprise a single
antigen-binding site.
[0089] In a most preferred embodiment, it is provided scFv
fragments.
[0090] Fragments that comprise or consist in VH-CDR3 and/or VL-CDR3
or functional portions thereof are especially preferred when CDR3
regions appear to be determinant in antigen recognition
specificity. Particular antigen-binding fragments comprise CDR1,
CDR2 and CDR3 domains of a VH and/or a VL of an antibody.
[0091] These antigen-binding fragments of the invention can be
combined together to obtain multivalent antigen-binding fragments,
such as diabodies, tribodies or tetrabodies. These multivalent
antigen-binding fragments are also part of the present
invention.
[0092] Bispecific or multispecific antibodies are also encompassed,
which are capable of simultaneously binding two different epitopes,
on the same or on different antigens. Bispecific or multispecific
antibodies can be obtained by different biochemical methods such as
chemical conjugation of two antibodies, fusion of two antibody
producing cell lines, or genetic approaches resulting in
recombinant bispecific or multispecific antibody molecules.
[0093] In a particular embodiment of the invention, antibodies of
the invention are monoclonal antibodies. The invention therefore
also relates to monoclonal antibodies, meaning that a composition
of these antibodies comprises antibodies that are identical, in
terms of antigen-binding specificity and, accordingly, in terms of
variable region composition.
[0094] In a further embodiment of the invention, antibodies or
antigen-binding fragments thereof are provided as a polyclonal
serum or are purified from a polyclonal serum.
[0095] According to the invention, the antibody may be a non-human
mammalian antibody, e.g. a murine antibody, or a chimeric antibody.
In a preferred embodiment, the antibody may be humanized. In a
particular embodiment, human antibodies are encompassed.
[0096] In another embodiment, the invention also relates to a
construct which comprises an antibody according to any of the
definition provided herein or an antigen-binding fragment thereof,
wherein said antibody or antigen-binding fragment thereof is
conjugated with a functionally different molecule.
[0097] A construct of the invention may be either a fusion protein
or a conjugate resulting from any suitable form of attachment
including covalent attachment, grafting, chemical bonding with a
chemical or biological group or a molecule, such as a protective
group or a molecule suitable for protection against proteases
cleavage in vivo, for improvement of stability and/or half-life of
the antibody or antigen-binding fragment, with a biologically
active molecule, especially a therapeutic active ingredient, e.g. a
toxin or a cytotoxic agent, a vector (including especially a
protein vector) suitable for targeting the antibody or
antigen-binding fragment to specific cells or tissues of the human
body, or with a label, e.g. a radioelement, or with a linker,
especially when fragments of the antibody are used.
[0098] Examples of preferred antibodies, or antigen-binding
fragments thereof, are described hereafter.
[0099] In a particular embodiment, it is provided an anti-HLA-G
antibody which comprises: [0100] (a) a heavy chain variable region
(VH), which comprises a heavy chain complementary determining
region 1 (HC CDR1) of SEQ ID NO: 8, and/or a heavy chain
complementary determining region 2 (HC CDR2) of SEQ ID NO: 10,
and/or a heavy chain complementary determining region 3 (HC CDR3)
of SEQ ID NO: 12; and/or [0101] (b) a light chain variable region
(VL), which comprises a light chain complementary determining
region 1 (LC CDR1) of SEQ ID NO: 2, and/or a light chain
complementary determining region 2 (LC CDR2) of sequence KVS and/or
a light chain complementary determining region 3 (LC CDR3) of SEQ
ID NO: 5.
[0102] Preferably such antibody comprises: [0103] (a) a heavy chain
variable region (VH), which comprises a heavy chain complementary
determining region 1 (HC CDR1) of SEQ ID NO: 8, a heavy chain
complementary determining region 2 (HC CDR2) of SEQ ID NO: 10, and
a heavy chain complementary determining region 3 (HC CDR3) of SEQ
ID NO: 12; and/or [0104] (b) a light chain variable region (VL),
which comprises a light chain complementary determining region 1
(LC CDR1) of SEQ ID NO: 2, a light chain complementary determining
region 2 (LC CDR2) of sequence KVS and a light chain complementary
determining region 3 (LC CDR3) of SEQ ID NO: 5.
[0105] Still preferably such antibody may comprise: [0106] (a) a
heavy chain variable region (VH) which comprises SEQ ID NO: 64 or a
homologous sequence showing more than 80%, preferably more than
90%, still preferably more than 95% identity with SEQ ID NO: 64
and/or [0107] (b) a light chain variable region (VL), which
comprises SEQ ID NO: 63 or a homologous sequence showing more than
80%, preferably more than 90%, still preferably more than 95%
identity with SEQ ID NO: 63.
[0108] In a particular embodiment, the homologous sequence differs
only by constitutive substitutions of amino acids.
[0109] In another embodiment, the homologous sequence is a
humanized sequence.
[0110] In a particular aspect, the antibody is a full-length
immunoglobulin G which comprises two heavy chains, including
variable region (VH) comprising SEQ ID NO: 64; and two light
chains, including variable region (VL), comprising SEQ ID NO: 63.
Such antibody is named 15E7 and is described in greater details in
the Experimental section.
[0111] In another particular embodiment, it is provided an antibody
which comprises: [0112] (a) a heavy chain variable region (VH),
which comprises a heavy chain complementary determining region 1
(HC CDR1) of SEQ ID NO: 23, and/or a heavy chain complementary
determining region 2 (HC CDR2) of SEQ ID NO: 25, and/or a heavy
chain complementary determining region 3 (HC CDR3) of SEQ ID NO:
27; and/or [0113] (b) a light chain variable region (VL), which
comprises a light chain complementary determining region 1 (LC
CDR1) of SEQ ID NO: 15, and/or a light chain complementary
determining region 2 (LC CDR2) of sequence KVS, and/or a light
chain complementary determining region 3 (LC CDR3) of SEQ ID NO:
18.
[0114] Preferably such antibody comprises: [0115] (a) a heavy chain
variable region (VH), which comprises a heavy chain complementary
determining region 1 (HC CDR1) of SEQ ID NO: 23, a heavy chain
complementary determining region 2 (HC CDR2) of SEQ ID NO: 25, and
a heavy chain complementary determining region 3 (HC CDR3) of SEQ
ID NO: 27; and/or [0116] (b) a light chain variable region (VL),
which comprises a light chain complementary determining region 1
(LC CDR1) of SEQ ID NO: 15, a light chain complementary determining
region 2 (LC CDR2) of sequence KVS, and a light chain complementary
determining region 3 (LC CDR3) of SEQ ID NO: 18.
[0117] Still preferably such antibody may comprise: [0118] (a) a
heavy chain variable region (VH) which comprises SEQ ID NO: 67 or a
homologous sequence showing more than 80%, preferably more than
90%, still preferably more than 95% identity with SEQ ID NO: 67;
and/or [0119] (b) a light chain variable region (VL), which
comprises SEQ ID NO: 65 or a homologous sequence showing more than
80%, preferably more than 90%, still preferably more than 95%
identity with SEQ ID NO: 65.
[0120] In a particular embodiment, the homologous sequence differs
only by constitutive substitutions of amino acids.
[0121] In another embodiment, the homologous sequence is a
humanized sequence.
[0122] In a preferred aspect, it is provided a scFv which comprises
a heavy chain variable region (VH) comprising SEQ ID NO: 67 and a
light chain variable region (VL), comprising SEQ ID NO: 65. Such
scFv fragment is named R4C-C3 and is described in greater details
in the Experimental section.
[0123] In another particular embodiment, it is provided an antibody
which comprises: [0124] (a) a heavy chain variable region (VH),
which comprises a heavy chain complementary determining region 1
(HC CDR1) of SEQ ID NO: 23, and/or a heavy chain complementary
determining region 2 (HC CDR2) of SEQ ID NO: 25, and/or a heavy
chain complementary determining region 3 (HC CDR3) of SEQ ID NO:
27; and/or [0125] (b) a light chain variable region (VL), which
comprises a light chain complementary determining region 1 (LC
CDR1) of SEQ ID NO: 15, and/or a light chain complementary
determining region 2 (LC CDR2) of sequence KVS, and/or a light
chain complementary determining region 3 (LC CDR3) of SEQ ID NO:
20.
[0126] Preferably such antibody comprises: [0127] (a) a heavy chain
variable region (VH), which comprises a heavy chain complementary
determining region 1 (HC CDR1) of SEQ ID NO: 23, a heavy chain
complementary determining region 2 (HC CDR2) of SEQ ID NO: 25, and
a heavy chain complementary determining region 3 (HC CDR3) of SEQ
ID NO: 27; and/or [0128] (b) a light chain variable region (VL),
which comprises a light chain complementary determining region 1
(LC CDR1) of SEQ ID NO: 15, a light chain complementary determining
region 2 (LC CDR2) of sequence KVS, and a light chain complementary
determining region 3 (LC CDR3) of SEQ ID NO: 20.
[0129] Still preferably such antibody may comprise: [0130] (a) a
heavy chain variable region (VH) which comprises SEQ ID NO: 67 or a
homologous sequence showing more than 80%, preferably more than
90%, still preferably more than 95% identity with SEQ ID NO: 67;
and/or [0131] (b) a light chain variable region (VL), which
comprises SEQ ID NO: 66 or a homologous sequence showing more than
80%, preferably more than 90%, still preferably more than 95%
identity with SEQ ID NO: 66.
[0132] In a particular embodiment, the homologous sequence differs
only by constitutive substitutions of amino acids.
[0133] In another embodiment, the homologous sequence is a
humanized sequence.
[0134] In another aspect, it is provided a scFv which comprises a
heavy chain variable region (VH) comprising SEQ ID NO: 67 and a
light chain variable region (VL), comprising SEQ ID NO: 66. Such
scFv fragment is named R5C-D8.
[0135] The sequences of the variable regions of the antibodies are
listed in the sequence listing, and described as follows.
TABLE-US-00003 VL .kappa. chain of antibody 15E7: FR1: (SEQ ID NO:
1) DVLMTQIPFSLPVSLGDQASISCRSS CDR1: (SEQ ID NO: 2) QSIVHRSGNTY FR2:
(SEQ ID NO: 3) LEWYLQKPGQSPKLLIY CDR2: KVS FR3: (SEQ ID NO: 4)
NRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYC CDR3: (SEQ ID NO: 5) FQGSHLPPT
FR4: (SEQ ID NO: 6) FGGTTLEIK VH chain of antibody 15E7: FR1: (SEQ
ID NO: 7) QVQLQQPGAELVRPGSSVKLSCKAS CDR1: (SEQ ID NO: 8) GYTFTDYW
FR2: (SEQ ID NO: 9) MDWVKQRPGQGLEWIGT CDR2: (SEQ ID NO: 10)
IYPSDSST FR3: (SEQ ID NO: 11)
HYNQEFKGKATMTVDKSSSTAYMHLSSLTSEDSAVYYC CDR3: (SEQ ID NO: 12)
AREGLAGVFYFDY FR4: (SEQ ID NO: 13) WGQGTTLTVSS VL .kappa. chain of
scFv R4C-C3 FR1: (SEQ ID NO: 14) DVLMTQTPLSLPVSLGDQASISCRSS CDR1:
(SEQ ID NO: 15) QSLVHSNGNTY FR2: (SEQ ID NO: 16) LHWYLQKPGQSPKLLIY
CDR2: KVS FR3: (SEQ ID NO: 17) NRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFC
CDR3: (SEQ ID NO: 18) SQSTHFPPT FR4: (SEQ ID NO: 19) FGGGTKLEII VL
.kappa. chain of scFv R5C-D8 FR1: (SEQ ID NO: 14)
DVLMTQTPLSLPVSLGDQASISCRSS CDR1: (SEQ ID NO: 15) QSLVHSNGNTY FR2:
(SEQ ID NO: 16) LHWYLQKPGQSPKLLIY CDR2: KVS FR3: (SEQ ID NO: 17)
NRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFC CDR3: (SEQ ID NO: 20)
SQSTHVPPT FR4: (SEQ ID NO: 21) FGAGTKLELK VH chain of scFv's R4C-C3
& R5C-D8 FR1: (SEQ ID NO: 22) QVQLKQSGPQLVRPGASVKIPCKAS CDR1:
(SEQ ID NO: 23) GYSFTNYW FR2: (SEQ ID NO: 24) MHWVKQRPGQGLEWIGM
CDR2: (SEQ ID NO: 25) IAPSDSDS FR3: (SEQ ID NO: 26)
RLNQNFKDKATLTVDKSSSTAYMQLSSPTSEDSAVYYC CDR3: (SEQ ID NO: 27)
AREGVTMITTGLDY FR4: (SEQ ID NO: 28) WGQGTTLTVSS
[0136] Additional antibodies (named N27F12 and N38F4) and scFv
(named 3157-057-R6B-C10, 3157-057-R6B-G3 and 3157-057-R6B-H10) have
been produced. The sequences of the variable regions of said
additional antibodies and scFv are listed in the sequence listing,
and described as follows.
TABLE-US-00004 VL .kappa. chain of antibody N27F12: FR1: (SEQ ID
NO: 68) ENVLTQSPAIMAASLGEKVTMTCSAS CDR1: (SEQ ID NO: 69) SSVSSNF
FR2: (SEQ ID NO: 70) LHWYQQKSGTSPKLWIY CDR2: GTS FR3: (SEQ ID NO:
71) NLASGVPARFSGSGTGISYSLTVSNMEAENDAAYYC CDR3: (SEQ ID NO: 72)
QQWNAYPFT FR4: (SEQ ID NO: 21) FGAGTKLELK VH chain of antibody
N27F12: FR1: (SEQ ID NO: 73) EVKLEESGGGLVQPGGSMKLSCVAS CDR1: (SEQ
ID NO: 74) GFTFSSYW FR2: (SEQ ID NO: 75) LSWVRQSPEKGLEWVAE CDR2:
(SEQ ID NO: 76) VRLKSDNYAT FR3: (SEQ ID NO: 77)
SYAESVKGKFTISRDDANSRLYLQMNSLRPEDTGIYYC CDR3: (SEQ ID NO: 78) TTGDY
FR4: (SEQ ID NO: 13) WGQGTTLTVSS VL .kappa. chain of antibody
N38F4: FR1: (SEQ ID NO: 79) DVVMTQIPLSLPVSLGDQASISCRSS CDR1: (SEQ
ID NO: 80) QSLVNSNGNTL FR2: (SEQ ID NO: 16) LHWYLQKPGQSPKLLIY CDR2:
KVS FR3: (SEQ ID NO: 17) NRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFC CDR3:
(SEQ ID NO: 81) SQSTHVPWT FR4: (SEQ ID NO: 82) FGGGTKLEIK VH chain
of antibody N38F4: FR1: (SEQ ID NO: 73) EVKLEESGGGLVQPGGSMKLSCVAS
CDR1: (SEQ ID NO: 83) GLTFSSYW FR2: (SEQ ID NO: 84)
MSWVRQSPEKGLEWVAE CDR2: (SEQ ID NO: 85) IRLRSDNYVK FR3: (SEQ ID NO:
86) QYADSVKGRFTISRDDSKGRLYLQMNRLRGDDTGIYFC CDR3: (SEQ ID NO: 78)
TTGDY FR4: (SEQ ID NO: 13) WGQGTTLTVSS VL .kappa. chain of scFv
3157-057-R6B-C10 and 3157-057-R6B-G3 FR1: (SEQ ID NO: 14)
DVLMTQTPLSLPVSLGDQASISCRSS CDR1: (SEQ ID NO: 87) QTIVHSNGNTY FR2:
(SEQ ID NO: 3) LEWYLQKPGQSPKLLIY CDR2: KVS FR3: (SEQ ID NO: 4)
NRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYC CDR3: (SEQ ID NO: 88)
FQGSHVPPT FR4: (SEQ ID NO: 82) FGGGTKLEIK VH chain of scFv
3157-057-R6B-C10 FR1: (SEQ ID NO: 89) EVQLQQSGAELVKPGTSVKLSCKAS
CDR1: (SEQ ID NO: 90) GYTFTRNW FR2: (SEQ ID NO: 91)
ITWVRLRPGQGLEWIGD CDR2: (SEQ ID NO: 92) IYPGDAST FR3: (SEQ ID NO:
93) HYNGKFKNKATLTVDTSSSTAYLQVSSLTSEDSAVYYC CDR3: (SEQ ID NO: 94)
AREQVQFAMFFDV FR4: (SEQ ID NO: 95) WGTGATVTVSS VH chain of scFv
3157-057-R6B-G3 FR1: (SEQ ID NO: 96) QVQLQQPRAELVKPGASVKMSCKAS
CDR1: (SEQ ID NO: 97) GYTFARYW FR2: (SEQ ID NO: 98)
ISWLKLRPGQGLEWIGD CDR2: (SEQ ID NO: 99) IYPGDDST FR3: (SEQ ID NO:
100) HYNGKFKNKATLTVDTSTSTAYIQLSSLTSEDSAVYYC CDR3: (SEQ ID NO: 94)
AREQVQFAMFFDV FR4: (SEQ ID NO: 95) WGTGATVTVSS VL .kappa. chain of
scFv 3157-057-R6B-H10 FR1: (SEQ ID NO: 14)
DVLMTQTPLSLPVSLGDQASISCRSS CDR1: (SEQ ID NO: 101) QSIVHSNGNTY FR2:
(SEQ ID NO: 3) LEWYLQKPGQSPKLLIY CDR2: KVS FR3: (SEQ ID NO: 4)
NRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYC CDR3: (SEQ ID NO: 88)
FQGSHVPPT FR4: (SEQ ID NO: 82) FGGGTKLEIK VH chain of scFv
3157-057-R6B-H10 FR1: (SEQ ID NO: 7) QVQLQQPGAELVRPGSSVKLSCKAS
CDR1: (SEQ ID NO: 8) GYTFTDYW FR2: (SEQ ID NO: 9) MDWVKQRPGQGLEWIGT
CDR2: (SEQ ID NO: 10) IYPSDSST FR3: (SEQ ID NO: 102)
HYNQEFKGKATMTVDKSSSTAYMHLGSLTSEDSAVYYC
CDR3: (SEQ ID NO: 12) AREGLAGVFYFDY FR4: (SEQ ID NO: 13)
WGQGTTLTVSS
[0137] The present disclosure also provides antibody variants of
the above preferred antibodies, with improved biological properties
of the antibody, such as higher binding affinity. Amino acid
sequence variants of the antibody can be prepared by introducing
appropriate nucleotide changes into the antibody nucleic acid, or
via peptide synthesis. Such modifications include, for example,
deletions from, and/or insertions into and/or substitutions of,
residues within the amino acid sequences of the antibody. Any
combination of deletion, insertion, and substitution is made to
achieve the final construct, provided that the final construct
possesses the desired characteristics. Nucleic acid molecules
encoding amino acid sequence variants of the antibody can be
prepared by a variety of methods known in the art. These methods
include, but are not limited to, oligonucleotide-mediated (or
site-directed) mutagenesis, PCR mutagenesis, and cassette
mutagenesis of an earlier prepared variant or a non-variant
(natural) version of the antibody. In one embodiment, the
equilibrium dissociation constant (K.sub.D) value of the antibodies
of the invention is less than 10.sup.-8M, particularly less than
10.sup.-9M or 10.sup.-10 M. The binding affinity may be determined
using techniques known in the art, such as ELISA or biospecific
interaction analysis, or other techniques known in the art.
[0138] Any of the antibodies described herein can be examined to
determine their properties, such as antigen-binding activity,
antigen-binding specificity, and biological functions, following
routine methods.
[0139] Any of the antibodies described herein can be modified to
contain additional non-proteinaceous moieties that are known in the
art and readily available, e.g., by pegylation, glycosylation, and
the like. Modifications that can enhance serum half-life are of
interest.
Production of the Anti-HLA-G Antibodies by Immunization
[0140] In an aspect of the invention, the immunogenic peptide
described above may be useful as an immunogen for producing
antibodies specific for the .alpha.3 domain of a HLA-G protein.
[0141] For illustration purposes, the antibodies or fragments
thereof of the invention may thus be obtained through immunization
of a mammal, in particular a rodent, especially mice or rats, with
an immunogenic peptide as described above. It can be concluded that
various mammal genotypes are suitable for implementing the present
invention through immunization of a mammal.
[0142] Immunization protocols may encompass priming and boosting
steps, as described in greater details below.
[0143] The invention thus also relates to a method of production of
an antibody or an antigen-binding fragment thereof according to the
present invention, which comprises
a. Administering to a non-human animal, the immunogenic peptide as
described above, b. Recovering from sera or plasma samples obtained
from the animals the elicited antibodies and checking their
specificity for the .alpha.3 domain of HLA-G protein, and; c.
Optionally, cloning the recovered antibodies, and d. Optionally,
preparing antigen-binding fragments from the recovered
antibodies.
[0144] Administration, recovery of generated antibodies or
antigen-binding fragments and subsequent cloning can be achieved
through conventional methods in the art. Characterization methods
prior to cloning using for example advanced sequencing methods are
also well known in the art.
[0145] The preparation of antigen-binding fragments from the
recovered antibodies can also be achieved through conventional
methods in the art, in particular through high-throughput synthesis
technologies.
[0146] Host animals for antibodies or antigen-binding fragments
production can be mammals to the exclusion of the human, especially
rodents, in particular mice.
[0147] According to a particular embodiment, the method of
production disclosed herein also involves a step of sacrificing the
host animals used for the production of the antibodies of the
invention. According to a particular embodiment, the method of
production of an antibody or an antigen-binding fragment thereof
according to the present invention encompasses the concomitant
administration, in step a., of an adjuvant, the latter being
defined as any ingredient, in particular compound, that acts to
assist, accelerate, prolong or enhance antigen-specific immune
responses when used in combination with administrated antigen(s) or
immunogenic antigen fragment(s). Adjuvants are well known in the
art of immunization (or vaccination) and immune-therapy.
[0148] According to a particular embodiment, administration
according to step a. of the above-disclosed method is performed
using a prime-boost immunization protocol implying a first
administration (prime immunization or prime administration) of
active immunogenic agents, and then at least one further
administration (boost immunization or boost administration) that is
separated in time from the first administration within the course
of the immunization protocol. Boost immunizations encompass one,
two, three or more administrations.
[0149] In a particular embodiment, the used prime-boost
immunization protocol is either a homologous or a heterologous
immunization protocol, meaning that the administered active,
immunogenic, ingredients (e.g. antibodies or fragments) are
respectively the same in the prime and boost administrations, or
different.
[0150] In a particular embodiment, administration of active,
immunogenic, ingredients in step a. of the above-mentioned method,
including when a prime administration is performed and/or when a
boost immunization is performed, is made concomitantly with an
adjuvant, for example a Freund's adjuvant. Adjuvants are substances
well known in the art.
[0151] In a specific embodiment, adjuvant administration is
performed at both prime and boost immunizations, in particular when
polypeptides or immunogenic fragments thereof are used for
immunization.
[0152] Details of an immunization protocol that may be used as is
or serve as a basis to design an immunization protocol aimed at
producing antibodies or antigen-binding fragments thereof using
immunization are given in the Example section below.
[0153] In another embodiment, the mammal is immunized with a
nucleic acid or vector that encodes said immunogenic peptide, e.g.
by means of DNA immunization.
[0154] Several delivery methods for DNA immunization are commonly
available, such as intramuscular or intradermal injection of the
nucleic acid or vector in saline solution, which delivers the DNA
to the extracellular spaces. This method may be assisted by
"electroporation", which uses electrical stimulation of biological
tissues to transiently permeabilize cell(s) membrane(s).
Alternatively, "gene-gun delivery" may be used, which involves
bombarding the skin with plasmid-coated gold particles by employing
ballistic devices, which enables DNA delivery directly into cell(s)
cytoplasm. Alternatively, "needle free devices" may be used which
rely on compressed to force the plasmid DNA into cells in the
epidermis and dermis.
[0155] For polyclonal antibody preparation, serum is obtained from
an immunized non-human animal and the antibodies present therein
isolated by well-known techniques. The serum may be affinity
purified using the immunogenic peptide set forth above linked to a
solid support so as to obtain anti HLA-G antibodies.
[0156] In an alternate embodiment, lymphocytes from a non-immunized
non-human mammal are isolated, grown in vitro, and then exposed to
the immunogen in cell culture. The lymphocytes are then harvested
and the fusion step described below is carried out.
[0157] For monoclonal antibodies, the next step is the isolation of
splenocytes from the immunized non-human mammal and the subsequent
fusion of those splenocytes with an immortalized cell in order to
form an antibody-producing hybridoma, as described in Harlow et
al., 1988; Hammerling, et al, 1981.
[0158] Alternatively, monoclonal antibodies of the invention, or
fragments thereof, can be prepared using any other known
techniques, including the use of recombinant, and phage display
technologies, or a combination thereof.
[0159] Recombinant production of the monoclonal antibodies or
fragments thereof involves expressing nucleic acids that encode the
antibodies or fragments thereof in suitable host cells, as
described below.
Recombinant Production of the Anti-HLA-G Antibodies
[0160] The invention also relates to a nucleic acid molecule
encoding an antibody or an antigen-binding fragment thereof of the
invention, as disclosed herein.
[0161] In particular it is provided a nucleic acid comprising a
nucleotide sequence encoding an antibody heavy chain variable
region (VH), an antibody light chain variable region (VL) or both,
of the anti-HLA-G antibody as described above.
[0162] Nucleotide sequences of the CDRs herein described can be
easily designed or sequenced.
[0163] For illustration purposes, the nucleotide sequences of the
light and heavy chain variable regions of monoclonal antibody 15E7
are SEQ ID NO: 35 and SEQ ID NO: 38, shown in FIGS. 2A and 3A,
respectively.
[0164] Nucleotide sequence of the light chain variable region of
scFv R4C-C3 is SEQ ID NO: 41 shown in FIG. 4A while the R4C-C3
heavy chain nucleotide sequence, namely SEQ ID NO: 46, is shown in
FIG. 5A.
[0165] It is further described a method for producing recombinant
antibodies, or fragments thereof. Nucleic acids encoding heavy and
light chains of the antibodies of the invention are inserted into
expression vectors. The light and heavy chains can be cloned in the
same or different expression vectors. The DNA segments encoding
immunoglobulin chains are operably linked to control sequences in
the expression vector(s) that ensure the expression of
immunoglobulin polypeptides. Such control sequences include a
signal sequence, a promoter, an enhancer, and a transcription
termination sequence. Expression vectors are typically replicable
in the host organisms either as episomes or as an integral part of
the host chromosomal DNA. Commonly, expression vectors will contain
selection markers, e.g., tetracycline or neomycin, to permit
detection of those cells transformed with the desired DNA
sequences.
[0166] In one example, both the heavy and light chain coding
sequences are included in one expression vector. In another
example, each of the heavy and light chains of the antibody is
cloned into an individual vector. In the latter case, the
expression vectors encoding the heavy and light chains can be
co-transfected into one host cell for expression of both chains,
which can be assembled to form intact antibodies either in vivo or
in vitro. Alternatively, the expression vector encoding the heavy
chain and that encoding the light chain can be introduced into
different host cells for expression each of the heavy and light
chains, which can then be purified and assembled to form intact
antibodies in vitro.
[0167] The antibodies as described herein, or fragments thereof,
may be produced in prokaryotic or eukaryotic expression systems,
such as bacteria, yeast, filamentous fungi, insect, and mammalian
cells. It is not necessary that the recombinant antibodies of the
invention be glycosylated or expressed in eukaryotic cells;
however, expression in mammalian cells is generally preferred.
Examples of useful mammalian host cell lines are human embryonic
kidney line (293 cells), baby hamster kidney cells (BHK cells),
Chinese hamster ovary cells/- or +DHFR (CHO, CHO-S, CHO-DG44,
Flp-in CHO cells), African green monkey kidney cells (VERO cells),
and human liver cells (Hep G2 cells).
[0168] Mammalian tissue cell culture is preferred to express and
produce the polypeptides because a number of suitable host cell
lines capable of secreting intact immunoglobulins have been
developed in the art, and include the CHO cell lines, various Cos
cell lines, HeLa cells, preferably myeloma cell lines, or
transformed B-cells or hybridomas.
[0169] Expression vectors for these cells can include expression
control sequences, such as an origin of replication, a promoter,
and an enhancer, and necessary processing information sites, such
as ribosome binding sites, RNA splice sites, polyadenylation sites,
and transcriptional terminator sequences. Preferred expression
control sequences are promoters derived from immunoglobulin genes,
SV40, adenovirus, bovine papillomavirus, cytomegalovirus and the
like.
[0170] The vectors containing the polynucleotide sequences of
interest (e.g., the heavy and light chain encoding sequences and
expression control sequences) can be transferred into the host cell
by well-known methods, which vary depending on the type of cellular
host. For example, calcium phosphate treatment or electroporation
may be used for other cellular hosts. (See generally Sambrook et
al., Molecular Cloning: A Laboratory Manual (Cold Spring Harbor
Press, 2nd ed., 1989). When heavy and light chains are cloned on
separate expression vectors, the vectors are co-transfected to
obtain expression and assembly of intact immunoglobulins.
[0171] Host cells are transformed or transfected with the vectors
(for example, by chemical transfection or electroporation methods)
and cultured in conventional nutrient media (or modified as
appropriate) for inducing promoters, selecting transformants, or
amplifying the genes encoding the desired sequences.
[0172] Once expressed, the antibodies of the present invention, or
fragments thereof, can be further isolated or purified to obtain
preparations that substantially homogeneous for further assays and
applications. Standard protein purification methods known in the
art can be used. For example, suitable purification procedures may
include fractionation on immunoaffinity or ion-exchange columns,
ethanol precipitation, high-performance liquid chromatography
(HPLC), sodium dodecyl sulfate polyacrylamide gel electrophoresis
(SDS-PAGE), ammonium sulfate precipitation, and gel filtration (see
generally Scopes, Protein Purification, Springer-Verlag, N.Y.,
1982). Substantially pure immunoglobulins of at least about 90 to
95% homogeneity are preferred, and 98 to 99% or more homogeneity
most preferred, for pharmaceutical uses.
Phage Display Methods
[0173] Antibodies with the desired binding characteristics can also
be produced using phage display libraries and screening.
[0174] In certain phage display methods, repertoires of VH and VL
genes are separately cloned by polymerase chain reaction (PCR) and
recombined randomly in phage libraries, which can then be screened
for antigen-binding phage as described in Winter et al., Ann. Rev.
Immunol., 12: 433-455 (1994). Phages typically display antibody
fragments, either as single-chain Fv (scFv) fragments or as Fab
fragments. Libraries from immunized sources provide high-affinity
antibodies to the immunogen without the requirement of constructing
hybridomas. Alternatively, the naive repertoire can be cloned
(e.g., from human) to provide a single source of antibodies to a
wide range of non-self and also self-antigens without any
immunization. Finally, naive libraries can also be made
synthetically by cloning non-rearranged V-gene segments from stem
cells, and using PCR primers containing random sequence to encode
the highly variable CDR3 regions and to accomplish rearrangement in
vitro.
Therapeutic Uses
[0175] The anti HLA-G antibodies or antigen-binding fragments
thereof, nucleic acids encoding such antibodies or fragments, or
vectors expressing the same, are useful in treating pathologies
such as cancer or carcinogenic diseases as well as related or
associated diseases or conditions, when these pathologies are
associated with a tumor escape mechanism involving HLA-G. More
generally the anti-HLA-G antibodies or antigen-binding fragments
thereof are useful in treating pathologies involving inappropriate
expression of HLA-G proteins in a host.
[0176] More specifically, it is herein described a method for
treating a cancer or a viral infection, which method comprises
administering a composition comprising an anti-HLA-G antibody or an
antigen-binding fragment thereof, nucleic acids encoding such
antibodies or fragments, or vectors expressing the same, in a
patient in need thereof.
[0177] The anti-HLA-G antibodies or antigen-binding fragments
thereof may be used as the sole active ingredient, or in
combination with another treatment method, such as chemotherapy
treatment, radiotherapy treatment, or another immunotherapy
treatment including therapeutic vaccination.
[0178] The anti-HLA-G antibodies described here, alone or combined
with other therapies, are useful to counteract the immune escape
mechanisms related to HLA-G and boost the overall antitumor effect
and benefit cancer patients.
[0179] In a particular embodiment, the antibodies, or
antigen-binding fragments thereof, of the invention, may be
blocking antibodies. "Blocking antibodies", or "neutralizing
antibodies", refer to antibodies which inhibit HLA-G binding to at
least leukocyte immunoglobulin-like receptor B1 (LILRB1/ILT2/CD85j)
or LILRB2 (ILT4/CD85 d).
[0180] According to a particular embodiment, binding between at
least one or several of the following HLA-G protein isoforms:
HLA-G1, HLA-G2, HLA-G5 or HLA-G6 and their receptors recognized by
the .alpha.3 domain is prevented.
[0181] In a specific embodiment, an antibody or an antigen-binding
fragment thereof of the invention blocks the binding of a HLA-G
protein exhibiting an .alpha.3 domain to at least one of LILRB1 or
LILRB2 receptors, in particular blocks the binding of said HLA-G
protein to both LILRB1 and LILRB2 receptors.
[0182] In another embodiment, the antibodies, or antigen-binding
fragments thereof, of the invention, may be conjugated to a
cytotoxic agent. In some aspects, such a construction (also named
antibody-drug conjugate or ADC) further comprises at least one
spacer or linker, which can be a peptide linker or a non-peptide
linker. Such linkers may be cleavable or not cleavable. Several
ways of linking the antibody to the cytotoxic agents are known to
the skilled person. ADCs are typically produced by conjugating the
cytotoxic agent to the antibody through the side chains of either
surface-exposed lysines or free cysteines generated through
reduction of interchain disulfide bonds.
[0183] The cytotoxic agent or cytotoxin can be any molecule known
in the art that inhibits or prevents the function of cells and/or
causes destruction of cells (cell death), and/or exerts
anti-neoplastic/anti-proliferative effects. A number of classes of
cytotoxic agents are known to have potential utility in ADC
molecules. These include, but are not limited to, amanitins,
auristatins, daunomycins, doxorubicins, duocarmycins, dolastatins,
enediynes, lexitropsins, taxanes, puromycins, maytansinoids, vinca
alkaloids, tubulysins and pyrrolobenzodiazepines. Toxins, including
plant toxins and bacterial toxins, may be used as a cytotoxic
agent, e.g. tetanus or diphtheria toxins, ricin, saponin, endotoxin
A, etc.
[0184] In a particular embodiment, the antibodies, or
antigen-binding fragments thereof, of the invention, may be
conjugated to a radionucleide.
[0185] In still another embodiment, the antibodies, or
antigen-binding fragments thereof, of the invention, may be
engineered (e.g. modified or chimerized) so that they comprise a Fc
region that promotes antibody-dependent cell-mediated toxicity
(ADCC), or complement dependent cytotoxicity (CDC). Many Fc
variants have already been described for that purpose, e.g. Lazar
et al, 2006; Moore et al, 2010.
[0186] Such antibodies or conjugates are useful in treating
cancer.
[0187] Cancer refers to any type of cancer, and may be preferably
chosen from bladder cancer, kidney cancer, urogenital cancer and
melanoma. Other non-limitative examples of cancer diseases or
neoplastic conditions, are leukemia, basal cell carcinoma, breast
cancer, malignant mesothelioma, actinic keratosis, clear cell renal
carcinoma, retinoblastoma, spinous cell carcinoma, in situ
carcinoma, colorectal cancer, ovarian carcinoma, cutaneous T cell
lymphoma, endometrial adenocarcinoma, classical Hodgkin lymphoma,
lung carcinoma, cutaneous B cell lymphoma, gastric cancer,
ampullary cancer, biliary cancer, pancreatic ductal adenocarcinoma,
esophageal squamous cell carcinoma, hydatidiform moles.
[0188] During viral infections, up regulation of HLA-G expression
forms a part of the strategy used by some viruses to escape
destruction by the immune system.
[0189] Non-limitative examples of viral infections which can be
treated according to the present invention are HIV infection,
rabies virus infection or hepatitis B or hepatitis C virus
infection, as well as an infection by HCMV (Human Cytomegalovirus),
HSV-1 (Herpes Virus Simplex), or IAV (Influenza A Virus).
[0190] In another aspect, the present invention provides a
composition, e.g. a pharmaceutical composition, containing an
antibody or fragment thereof, as defined herein, formulated
together with a pharmaceutical carrier. As used herein,
"pharmaceutical carrier" includes any and all solvents, dispersion
media, coatings, antibacterial and antifungal agents, isotonic and
absorption delaying agents, and the like that are physiologically
compatible. Preferably, the carrier is suitable for intravenous,
intramuscular, subcutaneous, parenteral, spinal or epidermal
administration (e.g. by injection or infusion).
[0191] A composition of the present invention can be administered
by a variety of methods known in the art. The route and/or mode of
administration will vary depending upon the desired results. The
selected dosage level will depend upon a variety of factors
including the route of administration, the age, sex, weight,
condition, general health and prior medical history of the patient
being treated, etc. For example, the antibody of the invention can
be administrated at a dosage of 0.2-20 mg/kg from 3 times/week to 1
time/month.
[0192] In another aspect, the medicament or vaccine is a
composition comprising a nucleic acid encoding said antibody or
fragment, or a vector containing said nucleic acid.
[0193] The vector may advantageously be a viral vector, e.g.
selected from the group consisting of retroviral vectors,
lentivirus vectors, adenovirus vectors, vaccinia virus vectors, pox
virus vectors, measles virus vectors and adenovirus-associated
vectors.
[0194] The nucleic acid, vector or composition can be administered
directly or they can be packaged in liposomes or coated onto
colloidal gold particles prior to administration. In a particular
embodiment, the nucleic acid that encodes the antibody of the
invention can be administered in a naked form.
[0195] For genetic immunization, the vaccine compositions are
preferably administered intradermally, subcutaneously,
intramuscularly, into the tumors or in any types of lymphoid organs
by injection or by gas driven particle bombardment, and are
delivered in an amount effective to stimulate an immune response in
the host organism. In a preferred embodiment of the present
invention, administration comprises an electroporation step, also
designated herein by the term "electrotransfer", in addition to the
injection step.
[0196] The nucleic acids may also be administered ex vivo to
lymphoid or myeloid cells using liposomal transfection, particle
bombardment or viral transduction (including co-cultivation
techniques).
[0197] The treated cells are then reintroduced back into the
subject to be immunized.
[0198] In still another aspect, the immunogenic peptide, a nucleic
acid encoding said peptide, or a vector expressing said peptide, is
used for in vivo production of anti-HLA-G antibodies in a
patient.
Diagnostic Methods and Kits
[0199] The invention also provides means suitable for in vitro
detecting HLA-G proteins or monitoring or diagnosing a health
status or a pathologic condition, as well as means for monitoring
or diagnosing a health status or pathologic condition, involving in
a patient susceptible of presenting such a status or condition.
[0200] In a particular embodiment, the condition is a cancer or a
viral infection.
[0201] In particular, the invention relates to an in vitro method
for detecting HLA-G protein in a sample and/or monitoring or
diagnosing a health status or pathologic condition through the
analysis of a sample previously obtained from a patient susceptible
of presenting a specific health status or having a pathologic
condition, said method comprising: [0202] a. Contacting the sample
with antibodies or antigen-binding fragment thereof as disclosed
herein, under conditions enabling the formation of immune
complexes, and [0203] b. Detecting in vitro the resulting immune
complexes formed between said antibodies or antigen-binding
fragments thereof and HLA-G protein.
[0204] According to a particular embodiment, the present invention
enables the in vitro detection of HLA-G protein in a sample, for
example a sample previously obtained from a patient susceptible of
being pregnant, or a sample obtained from a patient having
undergone organ or tissue or cell transplantation(s). As a result,
the monitoring of a health status can be performed, i.e. a
physiological status that does not necessarily involve the presence
of a pathologic condition. Subsequent diagnosis of the presence or
absence of a pathologic condition can therefore also be
performed.
[0205] When the sample has been previously obtained from a patient
susceptible of presenting a pathologic condition, subsequent
monitoring or diagnosis of such a pathologic condition may also be
performed. In a particular embodiment, pathologic conditions
referred to are those disclosed above.
[0206] The invention also relates to a kit for an in vitro assay or
diagnostic method as disclosed above, said kit comprising:
a. An antibody or antigen-binding fragment thereof as disclosed
herein, b. Reagent(s) appropriate for the formation of immune
complex(es) between the antibody of (a)., or antigen-binding
fragment thereof and the sample to assay; c. Optionally, reagent(s)
appropriate for detecting the formation of the immune complex(es)
of step b.
[0207] The detection of HLA-G protein may be achieved by any
technique known in the art, such as immunohistochemistry or
detection in liquid-phase such as an ELISA assay. According to a
particular embodiment, there is provided a kit comprising: (a) a
support having an immobilized anti-HLA-G antibody bound thereto,
wherein the anti-HLA-G antibody is an antibody of the invention;
and (b) a mobile anti-HLA-G antibody (which binds to another
epitope of the HLA G protein) having a reporter molecule bound
thereto. The reporter molecule may be any molecule which is
detectable in a quantitative or nearly quantitative manner. For
example, a reporter molecule may be a colorimetric agent, a
fluorometric agent, a radioisotope, or an enzymatic agent having a
detectable end-point.
[0208] The method according to the invention may optionally
comprise the step of measuring HLA-G by comparing the quantity of
label detected in the biological sample with an HLA-G standard.
[0209] The method according to the invention involves a biological
sample. Such a sample may be selected from, but is not limited to a
tissue sample, e.g. a tumor tissue sample, a blood sample, a medium
contacting a tissue sample, and a medium contacting a cell, for
example when isolated cells are used, amniotic fluid, a medium
contacting an embryo. The inventive method may be used to diagnose
or detect an HLA-G indicative condition. In this embodiment, a
control value for an HLA-G indicative condition can be compared
with the quantity of HLA-G found in the sample. Certain conditions
may be indicated if HLA-G is low or absent, while others may be
indicated by increased levels of HLA-G. One skilled in the art
could easily determine the indicative levels useful in diagnosing a
condition. Such HLA-G indicative conditions may include, but are
not limited to pre-eclampsia, increased risk of pre-eclampsia,
adverse fetal outcome, increased risk of adverse fetal outcome,
cancer, or increased risk of cancer development.
[0210] Soluble HLA-G (sHLA-G) has also been reported as a biomarker
for embryo quality in human in vitro fertilization (IVF). In a
particular embodiment, the antibodies of the invention are thus
useful to monitor the presence of HLA-G protein in embryo culture
supernatants (ES), in order to assess the likelihood of success of
implantation in a context of an IVF.
[0211] The present invention, thus generally described above, will
be understood more readily by reference to the following examples,
which are provided by way of illustration and are not intended to
be limiting of the instant invention.
Abbreviations
APC: Antigen Presenting Cell
ATCC: American Type Culture Collection
.beta.2M: Beta-2-Microglobulin
BSA: Bovine Serum Albumin
CDR: Complementarity-Determining Regions
CFA: Complete Freund's Adjuvant
CTL: Cytotoxic T Lymphocytes
CTLA-4: Cytotoxic T-Lymphocyte-associated Antigen 4
DC: Dendritic Cell
[0212] DIC: diisopropylcarbodiimide
DNA: DeoxyriboNucleic Acid
DMEM: Dulbecco's Modified Eagle Medium
ELISA: Enzyme-Linked ImmunoSorbent Assay
EC: Effective Concentration
FACS: Fluorescence-Activated Cell Sorting
FCS: Fetal Calf Serum
FITC: Fluorescein IsoThioCyanate
FR: Framework Region
[0213] h: hour
HAT: Hypoxanthine-Aminopterin-Thymidine
HES: HydroxyEthyl Starch
HLA: Human Leukocyte Antigen
HPLC: Liquid Chromatography High Performance
HRP: HorseRadish Peroxidase
ICP: Immune Check Point
ID: IDentity
IFA: Incomplete Freund's Adjuvant
IgG: Immunoglobulin G
ILT-2: Immunoglobulin-Like Transcript 2
ILT-4: Immunoglobulin-Like Transcript 4
IMDM: Iscove's Modified Dulbecco's Media
IP: IntraPeritoneally
[0214] IPTG: Isopropyl .beta.-D-1-thiogalactopyranoside
IV: IntraVenous
IVF: In Vitro Fertilization
KDa: Kilo Dalton
[0215] KIR2DL4: Killer cell Immunoglobulin like Receptor 2 Ig
Domains and Long cytoplasmic tail 4
KLH: Keyhole Limpet Hemocyanin
LILRB1: Leukocyte Immunoglobulin Like Receptor B1
LILRB2: Leukocyte Immunoglobulin Like Receptor B2
M: Molar
MEM: Minimal Essential Medium
MHC: Major Histocompatibility Complex
[0216] mL: milliLiters NK: Natural Killer cell
nM: NanoMolar
OD: Optical Density
ON: Overnight
PAGE: PolyAcrylamide Gel Electrophoresis
PBS: Phosphate Buffered Saline
PC-1: Peptide Constrained-1
PCR: Polymerase Reaction Chain
[0217] PD-1: Programmed cell Death protein 1 PD-L1: Programmed cell
Death Ligand 1
PE: PhycoErythrin
PIR-B: Paired Immunoglobulin-Like Receptor B
PS: Penicillin/Streptomycin
RNA: RiboNucleic Acid
RPM: Revolutions Per Minute
RT: Room Temperature
SB: Super Broth
[0218] scFv: single-chain Variable Fragment
SDS: Sodium Dodecyl Sulfate
Sec: Seconds
SEQ: SEQuence
[0219] sHLA-G: soluble HLA-G
TBS: Tris Buffered Saline
TMB: TetraMethylBenzidine
UV: Ultra Violet
V: Volume
[0220] VH: Variable Heavy chain VL: Variable Light chain
.mu.L: MicroLiters
Examples
Materials and Methods
[0221] Peptide Synthesis
[0222] The PC-1 peptide [VTHHPVFDYEATLRC (SEQ ID NO:56)] used to
generate monoclonal antibodies was synthesized by Fmoc standard
chemistry using DIC as an activator on a Syro from MultiSynTech and
subsequently purified by reverse phase HPLC (RP-HPLC).
[0223] The PC1 peptide was analyzed by Liquid chromatography--Mass
spectrometry (LCMS).
[0224] Preparation of the Immunogen
[0225] The PC1 peptide was coupled to KLH via the side chain
C-terminal cysteine as follows: 5 mg of peptide were used for
conjugation. KLH protein (77600, ThermoFisher, Paris, France),
dissolved in PBS, was activated with the sulfo-MBS linker (22312,
ThermoFisher, Paris, France). Free linker was removed by dialysis.
Peptide dissolved in PBS was incubated with activated KLH. Free
peptide was removed by dialysis. The PC-1-KLH complex was dissolved
in PBS 1.times. (pH7.2) and stored at -20.degree. C.
[0226] Mice Immunization
[0227] Two different mouse strains (C57BL/6J and BALB/cJ),
purchased from Janvier laboratories (Le Genest-St-Isle, France) and
bred at Pasteur Institute animal facility (Paris, France), were
used for immunization. Mice were 7 weeks old upon the first
immunogen injection. They were intraperitoneally (IP) immunized
with an emulsion of 50 .mu.g of PC-1 peptide conjugated to KLH
mixed with Complete Freund's Adjuvant (CFA F5881; Sigma, Lyon,
France) (v/v), followed 10 days after by 1 IP injection with 50
.mu.g of PC-1-KLH mixed with Incomplete Freund's Adjuvant (IFA;
F5506; Sigma, Lyon, France) and then 3 injections with 25 .mu.g of
the PC-1-KLH/IFA at day 20, 30 and 185 after the first
injection.
[0228] The PC1-KLH/CFA or IFA emulsion was prepared by vortex for
30 minutes at RT in the dark. The antibody response was monitored
in plasma, from blood obtained by retro-orbital bleeding of
immunized mice, by flow cytometry (FACS) and ELISA analyses (as
described below).
[0229] Generation of Hybridomas
[0230] Mice were boosted intravenously (IV) with the immunogen 3
days before euthanasia. Spleens were harvested and splenocytes were
purified for subsequent fusions with the immortalized myeloma cell
line sp2/0-Ag14 in order to obtain antibody-producing hybridomas.
The fusions were performed using polyethylene glycol based standard
protocol (Kohler, G., C. Milstein. Continuous cultures of fused
cells secreting antibody of predefined specificity. Nature, 1975.
256(5517): p. 495-'7). The resulting hybridomas were then cultured
in a selective DMEM medium supplemented with L-Glutamine (4 mM),
heat inactivated FCS (20%), HAT
(Hypoxanthine-Aminopterin-Thymidine, 1.times.), HES (HydroxyEthyl
Starch 130, 2%) and Penicillin/Streptomycin (1%). Hybridomas were
allowed to grow for 7 to 14 days in the selection medium for colony
formation and antibody production. The production of antibodies
that specifically recognize the linear and circular PC-1 peptide
was assessed by ELISA and flow cytometry analysis respectively.
Positive hybridomas were cloned and grown in order to identify
single-cell-derived clones secreting monoclonal antibodies of
interest.
Phage Display Technology
[0231] Construction of the Anti-HLA-G Single-Chain Antibody Gene
Library
[0232] Spleen of each animal was sampled after the last boost in
order to isolate RNA using the Tri Reagent kit (Molecular Research
Center Inc., Cincinnati, USA) according to the manufacturer's
instructions. RNA was reverse transcribed by RT-PCR and the
resulting cDNA was amplified by PCR using primers intended for the
amplification of DNA encoding murine VH, VL.kappa. and VL.lamda..
PCR products were first cloned in the pGEM.RTM.-T easy vector
(Promega, Madison, Wis.), according to the manufacturer's
instructions, yielding to two antibody gene sub-libraries encoding
either the heavy (VH) or the light (VLk+VL.lamda.) chain.
[0233] Construction of the single-chain antibody (scFv) library was
performed as follows: firstly, the VL (VLk and VL.lamda.) PCR
products were cloned into the phagemid vector pTH; Secondly, the VH
PCR products were cloned into pTH containing the VLk or VL.lamda.
repertoire. The cloning site contains a (Gly.sub.4Ser).sub.3 linker
sequence flanked by the restriction enzyme sites for VH and VL
cloning followed by a hexahistidine tag and a c-myc tag. Plasmids
and phagemids were grown in E. coli XL1-Blue MRF' bacteria
(Stratagene, Amsterdam, Netherlands). Transformed bacteria
containing the scFv gene library were harvested and
plasmids/phagemids from the library were isolated using the
Nucleobond Plasmid Midi Kit (Macherey-Nagel; Duren, Germany)
according to the manufacturer's instructions, then aliquoted and
stored at -80.degree. C.
[0234] The size of the final scFv library was constituted of
1.2.times.10.sup.7 clones containing approximately 93% full-size
inserts as determined by PCR. The bacteria library was then
packaged as phages/scFv library using helper phages M13KO7. The
phages/scFv were produced at 30.degree. C. and 250 rpm for 16 h.
Cells were pelleted by centrifugation and the supernatant
containing the phages was precipitated using polyethylene glycol
procedure. The precipitated phages were resuspended, filtered
through a 0.45 .mu.M filter and stored at 4.degree. C. before phage
titration.
[0235] Screening the Library
[0236] The screening of the phage/scFv library was performed using
1 .mu.g/mL of biotinylated-PC1 peptide coated on streptavidin ELISA
high capacity plates (15501, Piece). Five rounds of panning with
increasing stringency (2, 4, 8 and 15 washes for each successive
round of panning) were applied. Free HLA-G PC1 peptide (10 .mu.g/mL
in TBS-Tween 20 0.1%) was used as a competitor for Phages/scFv
elution. For the recovery and amplification of the selected phages,
an exponentially growing E. coli culture was infected with the
eluted phage suspension after each round of panning.
[0237] To assess the reactivity of the selected phages, a
phage-ELISA using biotinylated HLA-G PC1 peptide as antigen was
performed after each round of panning. After the first and second
round of panning, the signal was at the same level as the
background; the signal increased to threefold the background after
the fourth round of panning. According to the phage display
technology, such signal increase corresponds to enrichment in
specific binders. The phagemid DNA was extracted from the library
after the fifth round of panning. 96 clones were isolated and
produced on deep well microtiter plate (Maxisorp, Nunc, Danemark).
Supernatants, containing phage particles, were tested by
phage-ELISA method and 6 PC1-specific binders were identified
(R4C-C3, R4C-B1, R4C-F2, R4C-F1, R4C-F12 and R5C-D8) and
sequenced.
[0238] scFv Production
[0239] For protein expression, phagemid DNA isolated from the
identified positive binders were transformed into the
non-suppressor E. coli strain HB2151. Single colonies randomly
chosen from the selected plates were inoculated into 5 mL of SB
medium (Super Broth) supplemented with carbenicillin and glucose
(1%). The cultures were incubated overnight under agitation at
37.degree. C., and then transferred to a larger-scale SB cultures
(500 .mu.L of culture were transferred to 500 mL of fresh SB
medium). Expression of the target proteins was induced by adding 1
mM IPTG (Isopropyl .beta.-D-1-thiogalactopyranoside) when the
cultures reached an OD.sub.600 of 1. Cells were grown overnight
(ON) at 16.degree. C., and then harvested by centrifugation. The
scFvs were extracted and purified using a nickel column (Ni-NTA
spin column, Qiagen, Valencia, Calif.) according to the
manufacturer's instructions.
Flow Cytometry Analysis
[0240] Cell Lines
[0241] K562 cells are human leukemia cells purchased from ATCC
(American Type Culture Collection CCL-243). K562-G1 and K562-PV
were obtained by nucleofection of K562 wild-type cells with either
a HLA-G1 encoding vector or the corresponding mock vector,
respectively. These cell lines were cultured in IMDM medium
supplemented with 10% heat-inactivated FCS and 1%
Penicillin/Streptomycin.
[0242] The lymphoblastoid cell lines, LCL-DES, LCL-BRO and
RPMI8866, expressing classical MHC Class I molecules but not HLA-G
were kindly gifted by D. Wiels (Institut Gustave Roussy, Villejuif,
France). These cells were cultured in RPMI 1640 medium supplemented
with 10% heat-inactivated FCS, 1% penicillin/streptomycin, 10 mM
sodium pyruvate and 200 g/L D-glucose.
[0243] Bioplex Beads, Receptors and Monoclonal Antibodies
[0244] Bioplex beads (MC10028-01 and MC10062-01) were purchased
from Bio-Rad (Marnes-la-Coquette, France), and PE-conjugated mouse
IgG1 (Clone P.3.6.8.2.1. 12-4714) from eBiosciences (Paris;
France), and FITC-conjugated rat IgG2a from BD Biosciences (clone:
R35-95 553929, Le Pont de Claix; France).
[0245] HLA-G6 and HLA-G5 Protein Production
[0246] Coding sequences for .alpha.1.alpha.3 domains of HLA-G6 and
.alpha.1.alpha.2.alpha.3 domains of HLA-G5 genes were cloned in
pAcGP67 baculovirus transfer vector. Genetic constructions and
plasmid amplifications of the pAcGP67 baculovirus vectors
containing the different inserts were produced by Genecust
(Luxembourg). Plasmids were amplified in DH5 bacteria hosts in
Proteople facility at Institut Pasteur (Paris, France). Transfer
vectors and AcMNPV linearized DNA (BaculoGold.TM. from BD) were
co-transfected into Spodoptera frugiperda (Sf9) cells allowing
recombination between homologous sites, transferring the inserts
from the transfer vector to the AcMNPV DNA. Recombinant viruses
coding for each protein were produced and used to infect Sf9 cells
producing then the recombinant proteins.
[0247] Once recombinant proteins were expressed, cells were lysed
and the lysate was added to an immobilized StrepTactin affinity
resin column. After several wash steps to remove non-specifically
bound proteins, bound StrepTag proteins were eluted with 2.5 mM
desthiobiotin. Purified eluted proteins were analyzed by SDS-PAGE
to validate the presence of HLA-G5, and were then aliquoted and
stored at -20.degree. C.
[0248] Coupling of Bioplex Beads
[0249] Bioplex beads were coated with the recombinant HLA-G5,
HLA-G6 proteins or with the synthetic circular cPC-1 peptide
(CTHHPVFDYEATLRC, SEQ ID NO: 52) following standard amine coupling
chemistry procedure using the kit provided by Bio-Rad
(Marnes-la-Coquette; France) according to supplier's instructions.
As specificity (negative) controls, uncoupled beads or beads coated
with a mutated peptide CTHHPVADAEATLRC (SEQ ID NO: 62) were used
respectively.
[0250] The circular cPC-1 peptide was designed to mimic the
conformational structure of VTHHPVFDYEATLRC (SEQ ID NO: 56) amino
acids region at positions 189-203 within the .alpha.3 domain of
HLA-G determined by previous crystallography studies (Clements et
al., 2005). Conformational mimicry was obtained by replacing the
N-terminal Valine residue of the PC-1 peptide with a Cysteine
residue resulting in the formation of a disulfide bond between the
N- and C-terminal Cysteine residues.
[0251] Analysis of Anti-HLA-G Sera and Monoclonal Antibodies
[0252] Detection of specific anti-HLA-G antibodies in sera of
immunized mice or in supernatants of clonogenic hybridomas cell
culture was assessed by flow cytometry. Flow cytometry was carried
out first using HLA-G5, HLA-G6 and cPC-1 peptide coated beads.
[0253] Beads were incubated with different dilutions of sera or
cell culture supernatants containing monoclonal antibodies for 1 h
at RT, then washed twice and incubated for 30 min at RT with
PE-conjugated goat anti-mouse IgG antibody (405307, Biolegend,
USA). Flow cytometry analyses were performed using LSR FORTESSA
(Beckton Dickinson, Le Pont-de-Claix, France); data were analyzed
with FlowJo X software (Tree star, Ashland, USA). To determine the
percentage of positive stained beads, electronic gates were set to
exclude 99% of the fluorescent beads with the isotype control.
Thus, positive stained beads were defined as those with staining
intensity higher than those exhibited by 99% of the isotype
control.
[0254] ELISA Assay
[0255] 96-well microplates were coated with the PC-1 peptide at 1
.mu.g/mL in PBS (100 .mu.L/well), incubated overnight at RT and
then blocked with 150 .mu.L/well of PBS-dried skimmed milk for 1 h
at RT. After one wash with PBS tween 0.05%, dilutions of sera or
monoclonal antibodies were added (50 .mu.L/well) for 2h at RT.
Plates were washed three times and peroxidase (HRP) conjugated goat
anti-Mouse IgG was added at 1/10000 in PBS-tween 0.05%, 1% BSA (50
.mu.L/well) for 1 h at RT. After three washes, plates were stained
with TMB substrate (KPL, Gaithersburg, USA) and read at
OD.sub.450.
[0256] For phage display, HLA-G PC1 free peptide or coupled to BSA
were coated onto 96-well microtiter plates (Maxisorp, Nunc,
Danemark). Detection was assessed using an anti-histidine tag
antibody (Qiagen, Courtaboeuf, France).
Additional Characterization of the Monoclonal Antibody 15E7
[0257] Isotyping
[0258] The 15E7 isotype was determined by ELISA assay using the
Clonotyping Southern kit, (Clinisciences, Nanterre, France)
according to the manufacturer's instructions. Briefly, plates were
coated with a capture antibody (specific for each isotype)
overnight at 4.degree. C., and then washed twice with PBS 0.05%
Tween. Plates were then allowed to warm at RT and the hybridoma
supernatant containing the 15E7 monoclonal antibody was added for 1
h at RT. HRP-conjugated anti-isotype secondary antibodies, provided
in the kit, were used at 1/2000. Plates were stained with TMB
substrate (Eurobio/KPL, Gaithersburg, USA) and read at
OD.sub.450.
[0259] Production of the 15E7 Monoclonal Antibody
[0260] The 15E7 hybridoma was grown in vivo as ascites in mice.
After sufficient growth to produce the desired monoclonal antibody,
ascites fluids containing the monoclonal antibody were purified.
Purification was achieved by chromatography using a standard
protein A-sepharose column. Elution fractions containing the 15E7
were pooled, dialyzed, and concentrated as needed. Concentration
was determined at OD.sub.280 with an UV scan and adjusted at 2
mg/mL.
[0261] Determination of the Binding Affinity (BLITZ Technology)
[0262] Binding affinity and binding kinetics were determined by the
BLITZ technology. The 15E7 monoclonal antibody was covalently
linked to a biosensors chip AR2G (Pall ForteBio) via primary amines
using standard amine coupling chemistry. Binding was measured by
incubating the chip coupled to 15E7 with different concentrations
of the PC-1 peptide coupled to BSA. The antigen-antibody
association kinetics was followed for 120 seconds and the
dissociation kinetics was followed for 100 seconds. The association
and dissociation curves fit to 1:1.
Example 1: Production of Anti-HLA-G Antibodies in Mice
[0263] Design of the Immunogen
[0264] The inventors designed a highly HLA-G specific peptide
corresponding to the .alpha.3 amino acid region 189-203 of HLA-G,
referenced as "Peptide Constrained: PC-1" (FIG. 1A; in bold and
underlined), and used it to immunize mice.
TABLE-US-00005 PC-1 sequence: (SEQ ID NO: 56) VTHHPVFDYEATLRC
[0265] PC-1 immunogen is expected to generate therapy-suitable
anti-HLA-G monoclonal antibodies specific for HLA-G
.alpha.3-containing isoforms independently of .beta.2M
association.
[0266] Immunization, Hybridoma Generation and scFv Production
[0267] The immunization protocol using the PC-1 peptide coupled to
KLH is described in Materials and Methods section. C57BL/6 and
BALB/c mice were used for peptide immunization.
[0268] Briefly, mice were intraperitoneally primed with PC-1-KLH
conjugate in CFA and boosted with 4 IP in IFA. Sera from immunized
mice were collected at different time points along the immunization
procedure and were tested using Bioplex-HLA-G5, HLA-G6 and cPC-1
coupled beads. For each experiment, positive and negative controls
were set up to determine the specific affinity of polyclonal
antibodies obtained. Sera were considered positive if HLA-G-peptide
beads showed a peak shift in FACS in comparison to those labelled
with sera from non-immunized mice.
[0269] When BALB/c and C57BL/6 mice were immunized with PC-1-KLH
peptide, significant levels of anti-HLA-G IgG antibodies were
detected in sera after each IP boost. FIG. 1B shows the staining of
HLA-G5-coated beads obtained in the presence of serum collected
from an immunized Balb/c mouse and a non-vaccinated control mouse.
Anti-HLA-G antibodies were significantly detected in a
dose-dependent manner even at the lowest doses of serum (dilution
1/1000). No specific binding was detected using control uncoupled
beads (data not shown). Mice with the highest anti-HLA-G antibody
titers were used for hybridoma generation or for phage display.
[0270] Fusions were done as described in Materials and Methods
section. ELISA positive hybridomas were subsequently cloned and
confirmed again by ELISA to detect the clones of interest producing
anti-HLA-G monoclonal antibodies.
[0271] Phage display process was carried out as detailed in
Material and Methods. The reactivity of scFv clones R4C-C3, R4C-B1,
R4C-F2, R4C-F1 and R5C-D8 to HLA-G peptides was assessed by ELISA.
The R4C-C3 and R5C-D8 clones showed a high reactivity to
Biotin-coupled PC1 peptide (FIG. 1C). R4C-C3 reacted with HLAG
protein isoforms.
[0272] The hybridoma clone 15E7 and the scFv clones R4C-C3 were
selected for further analysis.
Example 2: Genetic Characterization of the Mouse Monoclonal
Antibody 15E7 and scFv R4C-C3
[0273] The cDNA sequences encoding the light and heavy chain
variable regions of the monoclonal antibody 15E7 and the R4C-C3
scFv were obtained using standard PCR and DNA sequencing
methods.
[0274] Monoclonal Antibody 15E7
[0275] The nucleotide and amino acid sequences of the light chain
variable region of 15E7 are shown in FIG. 2A.
[0276] The nucleotide and amino acid sequences of the heavy chain
variable region of 15E7 are shown in FIG. 3A.
[0277] The greatest variability in the light and heavy chains is
located mainly within the hypervariable regions called
Complementarity-Determining Regions (CDRs) which define the
specificity of the antibody. Analysis of the 15E7 VL and VH
sequences led to the CDR1, CDR2 and CDR3 regions delineation of the
light and heavy chains respectively as shown in FIGS. 2A and 3A.
The sequence of the 15E7 .kappa. light chain was compared to the
known mouse germline immunoglobulin light chain sequences (FIG.
2B). The 15E7 light chain utilizes a VL segment from mouse germline
IGKV1-117 and a JK segment from mouse germline IGKJ1.
[0278] The comparison of the 15E7 heavy chain (.gamma.) sequence to
the known mouse germline immunoglobulin heavy chain sequences
demonstrated that the 15E7 heavy chain utilizes a VH segment from
mouse germline IGHV1-61, a JH segment from mouse germline IGHJ2 and
a DH segment from mouse germline IGHD4-1 (FIG. 3B).
[0279] These amino acid sequence comparisons highlight the strong
homology of the heavy (93.1%) and the light (94.6%) chain sequences
of 15E7 with the corresponding mouse germlines. Variations in the
sequence of the light chain are distributed throughout FR1 and FR4,
as well as in CDR1 and CDR3 regions (FIG. 2B), while variations in
the sequence of the heavy chain are mostly confined to CDR regions
and FR3 (FIG. 3B). Thus, these results demonstrate that the 15E7
monoclonal antibody is a mouse IgG that has undergone an affinity
maturation process and has acquired a strong specificity/affinity
for a specific HLA-G epitope.
[0280] The scFv Clone R4C-C3
[0281] The nucleotide and amino acid sequences of the light chain
variable regions of the scFv R4C-C3 is shown in FIG. 4A.
[0282] The R4C-C3 heavy chain nucleotide and amino acid sequences
as shown in FIG. 5A. The VL and VH sequences of scFv R4C-C3 were
analyzed and the CDRs regions of the light and heavy chains were
delineated as depicted in FIGS. 4A and 5A.
[0283] The sequences of the scFv R4C-C3 .kappa. light chains were
compared to the known mouse germline immunoglobulin light chain
sequences. This alignment demonstrated that the scFv R4C-C3 light
chain utilizes a VL segment from mouse germline IGKV1-110 and a JK
segment from mouse germline IGKJ1. The sequence alignments between
scFv R4C-C3 and its corresponding mouse germline segments are shown
in FIGS. 4B and 5B.
[0284] The comparison of the scFv heavy chain (.gamma.) sequence to
the known mouse germline immunoglobulin heavy chain sequences
demonstrated that this chain utilizes a VH segment from mouse
germline IGHV1S126, a JH segment from mouse germline IGHJ2 and a DH
segment from mouse germline IGHD2-12. The sequence alignment
between scFv R4C-C3 VH and the corresponding mouse germlines are
shown in FIG. 5B. These amino acid alignments revealed that the
sequences of light and the heavy chains of scFv R4C-C3 are 96.4%
and 82.8% homologous to the germlines sequences. Variations in the
light chain sequences are mainly located in the CDR3 regions (FIG.
4B), while variations in the heavy chain sequence are distributed
throughout FR1, FR2, FR3 and all CDRs (FIG. 5B). The high mutation
rate in the sequence of the heavy chain proves that scFv R4C-C3 has
undergone an affinity maturation process and acquired a strong
affinity for the HLA-G derived peptide.
Example 3: Characterization of Anti-HLA-G Monoclonal Antibody
15E7
[0285] Protein Analysis
[0286] The 15E7 monoclonal antibody was analyzed by SDS-PAGE gel
electrophoresis (FIG. 6A). The heavy chain molecular weight is
around 50 kDa and light chain around 25 kDa. Having two copies of
each, the molecular weight of 15E7 is estimated to 150 kDa
confirming that the monoclonal antibody 15E7 belongs to the murine
IgG 2a class.
[0287] Isotyping and Affinity Determination
[0288] The isotype of 15E7 was assessed by ELISA. 15E7 isotype was
determined to be IgG2a. The affinity of 15E7 was assessed by the
BLITZ technology as described in the Materials and Methods section.
Representative data are shown in FIG. 6B. Various concentrations of
the PC-1 peptide conjugated to BSA ranging from 5 to 600 nM were
incubated with the 15E7 coupled to the biosensor chip. For each
concentration, the association (k.sub.a) and dissociation (k.sub.d)
rates were measured and used to calculate the affinity constant
K.sub.D (k.sub.a/k.sub.d), evaluated here as 1.57 nM.
[0289] Specificity to HLA-G Proteins and Peptides
[0290] In order to determine the reactivity of 15E7 with the HLA-G5
and G6 protein and cPC-1 peptide, a flow cytometry based titration
was performed.
[0291] 15E7 antibody was titrated by serial dilution on
h.beta.2M-free HLA-G5; HLA-G6 and cPC-1 peptide coated beads as
well as on their negative counterparts (uncoupled beads or beads
coated with a mutated peptide). Results depicted in FIGS. 7A, 7B
and 7C show that 15E7 strongly binds to the cPC-1 peptide with an
EC.sub.50 value of 2 ng/mL, to the recombinant HLA-G5 protein with
an EC.sub.50 value of 28 ng/mL and to the recombinant protein
HLA-G6 with an EC.sub.50 of 120 ng/mL, respectively. This analysis
demonstrated the ability of 15E7 to bind specifically different
.beta.2M-free HLA-G isoforms.
[0292] The ability of 15E7 to bind .beta.2M-free HLA-G1 isoform
expressed on cell surface was also assessed. Indeed, K562-G1
expressing the HLA-G1 free isoform and K562-PV cells were incubated
with serial dilutions of 15E7 antibody and specific binding was
analyzed by flow cytometry in comparison to the isotype control
(IgG2a). Results depicted in FIG. 8 show that 15E7 specifically
binds to K562-G1 cells but not to K562-PV cells with an EC.sub.50
value of 5.0 .mu.g/mL.
[0293] A mild acid treatment releases cell surface .beta.2M
molecules leaving HLA class I free heavy chains attached to the
cell surface (Polakova et al., 1993; Storkus et al., 1993). The
expression of HLA-G antigens on untreated and pH3.0 treated K562-G1
cells was analyzed by flow cytometry using MEM-G/9 mAb directed to
native HLA-G/.beta.2M complexes. In addition, a mAb directed
against human .beta.2m was used to control the experiment and
validate the release of the latter. MEM-G/9 mAb as well as the
anti-.beta.2M mAb bind to untreated K562-G1 cells, however, acid
treatment reduced their binding. By contrast, marking by 15E7 mAb
increased demonstrating that it recognizes .beta.2M free HLA-G
heavy chains (FIG. 9A). K562-PV cells were used as negative control
(FIG. 9B).
[0294] The same experiments were conducted on JEG-3 cells
expressing the endogenous HLA-G1/.beta.2M complex. 15E7 mAb didn't
bind untreated JEG-3 cells, however the staining increased after
acid treatment while the staining of MEM-G/9 and anti-.beta.2M mAb
dropped to near background values (FIG. 9C).
[0295] These results confirm that the 15E7 Mab recognizes the
immunogenic cPC-1 peptide and an epitope expressed on cell surface
HLA-G in the absence of .beta.2M.
[0296] No Cross-Reactivity Towards Classical MHC Class I
Molecules
[0297] As mentioned above, one of the main concerns in developing
an anti-HLA-G monoclonal antibody was to obtain highly specific
antibodies for HLA-G with no cross-reactivity towards classical MHC
class I (MHC-I) molecules. The specificity of 15E7 to HLA-G and its
absence of cross-reactivity with classical MHC-I molecules were
evaluated by flow cytometry using different human MHC-I positive
cell lines, which do not express HLA-G.
[0298] Indeed, human lymphoma cell lines (LCL-DES, LCL-BRO and
RPMI8866), expressing human classical MHC-I molecules but not HLA-G
on their surface were stained with a fixed concentration of 15E7
(20 .mu.g/mL; 133 nM). This concentration was used since 80% of
K562-G1 cells were stained and no unspecific binding with the
isotype control was detected at this dosage. K562-G1 and K562-PV
cells were used as positive and negative controls, respectively.
FIG. 10 shows that 15E7 strongly binds to HLA-G1 expressing cells
(K562-G1) whereas HLA-G negative cells expressing classical MHC-I
molecules were not stained. It demonstrates that 15E7 monoclonal
antibody is specific to HLA-G proteins and does not present any
cross-reactivity against classical MHC class I molecules.
Discussion
[0299] The present work, shows how to produce anti-HLA-G antibodies
based on a HLA-G peptide immunization approach. The peptide (PC-1)
used for immunization was designed to be highly specific for HLA-G
in comparison with classical MHC class I molecules and contains
amino acids involved in the interaction of full length HLA-G with
its receptors LILRB1 and LILRB2. The inventors showed that, despite
the hydrophobic properties of this HLA-G .alpha.3 region, it was
possible to develop anti-HLA-G monoclonal antibodies using
different technologies, fusion (generation of hybridomas) and phage
display.
[0300] The anti-HLA-G antibodies described above are capable of
recognizing several isoforms of HLA-G. These antibodies bind to
endogenous cell surface .beta.2M-free HLA-G1. As they do not
cross-react with classical MHC class I molecules these HLA-G
specific antibodies could be used for diagnostic and therapeutic
purposes.
REFERENCES
[0301] Agaugue S, Carosella E D, Rouas-Freiss N. Role of HLA-G in
tumor escape through expansion of myeloid-derived suppressor cells
and cytokinic balance in favor of Th2--versus Th1/Th17. Blood 2011;
117: 7021-31. [0302] Altschul S F, Gish W, Miller W, Myers E W,
Lipman D J. Basic local alignment search tool. J Mol Biol 1990;
215:403-10. [0303] Altschul S F, Madden T L, Schaffer A A, Zhang J,
Zhang Z, Miller W, Lipman D J. Gapped BLAST and PSI-BLAST: a new
generation of protein database search programs. Nucleic Acids Res
1997; 25:3389-402. [0304] Blaschitz A, Hutter H, Leitner V, Pilz S,
Wintersteiger R, Dohr G, Sedlmayr P. Reaction patterns of
monoclonal antibodies to HLA-G in human tissues and on cell lines:
a comparative study. Hum Immunol 2000; 61: 1074-85. [0305]
Carosella E D, et al., HLA-G: from biology to clinical benefits.
Trends Immunol 2008; 29:125-32. [0306] Carosella E D, et al.,
Beyond the increasing complexity of the immunomodulatory HLA-G
molecule. Blood 2008; 111:4862-70. [0307] Carosella E D, et al.,
HLA-G: An Immune Checkpoint Molecule. Adv Immunol 2015; 127:33-144.
[0308] Clements C S, Kjer-Nielsen L, Kostenko L, Hoare H L,
Dunstone M A, Moses E, Freed K, Brooks A G, Rossjohn J, McCluskey
J. Crystal structure of HLA-G: a nonclassical MHC class I molecule
expressed at the fetal-maternal interface. Proc Natl Acad Sci USA
2005; 102: 3360-5. [0309] Desai S A, et al., Structural relatedness
of distinct determinants recognized by monoclonal antibody TP25.99
on beta 2-microglobulin-associated and beta 2-microglobulin-free
HLA class I heavy chains. J Immunol 2000; 165:3275-83. [0310] Ellis
S A, Palmer M S, McMichael A J. Human trophoblast and the
choriocarcinoma cell line BeWo express a truncated HLA Class I
molecule. J Immunol 1990; 144: 731-5. [0311] Favier, B., HoWangYin
K Y, Wu J, Caumartin J, Daouya M, Horuzsko A, Carosella E D,
LeMaoult J. Tolerogenic function of dimeric forms of HLA-G
recombinant proteins: a comparative study in vivo. PLoS One 2011;
6: e21011. [0312] Geraghty D E, Koller B H, Orr H R A human major
histocompatibility complex class I gene that encodes a protein with
a shortened cytoplasmic segment. Proc Natl Acad Sci USA 1987. 84:
9145-9. [0313] HoWangYin K Y, Loustau M, Wu J, Alegre E, Daouya M,
Caumartin J, Sousa S, Horuzsko A, Carosella E D, LeMaoult J.
Multimeric structures of HLA-G isoforms function through
differential binding to LILRB receptors. Cell Mol Life Sci 2012;
69:4041-9 [0314] Karlin S, Altschul S F. Methods for assessing the
statistical significance of molecular sequence features by using
general scoring schemes. Proc Natl Acad Sci USA 1990; 87:2264-8.
[0315] Karlin S, Altschul S F. Applications and statistics for
multiple high-scoring segments in molecular sequences. Proc Natl
Acad Sci USA 1993; 90:5873-7. [0316] Lazar G A, Dang W, Karki S,
Vafa O, Peng J S, Hyun L, Chan C, Chung H S, Eivazi A, Yoder S C,
Vielmetter J, Carmichael D F, Hayes R J, Dahiyat B I. Engineered
antibody Fc variants with enhanced effector function. Proc Natl
Acad Sci USA. 2006; 103: 4005-4010. [0317] Liang S, Baibakov B,
Horuzsko A. HLA-G inhibits the functions of murine dendritic cells
via the PIR-B immune inhibitory receptor. Eur J Immunol 2002; 32:
2418-26. [0318] Menier C, et al., Characterization of monoclonal
antibodies recognizing HLA-G or HLA-E: new tools to analyze the
expression of nonclassical HLA class I molecules. Hum Immunol 2003;
64:315-26. [0319] Moore G L, Chen H, Karki S, Lazar G A. Engineered
Fc variant antibodies with enhanced ability to recruit complement
and mediate effector functions. MAbs. 2010 March-April; 2(2):181-9.
[0320] Moy F J, et al., Analysis by NMR spectroscopy of the
structural homology between the linear and the cyclic peptide
recognized by anti-human leukocyte antigen class I monoclonal
antibody TP25.99*. J Biol Chem 2000; 275:24679-85. [0321] Naji A,
et al., Binding of HLA-G to ITIM-bearing Ig-like transcript 2
receptor suppresses B cell responses. J Immunol 2014; 192:1536-46.
[0322] Polakova K, Karpatova M, Russ G. Dissociation of beta
2-microglobulin is responsible for selective reduction of HLA class
I antigenicity following acid treatment of cells. Mol Immunol 1993;
30:1223-30. [0323] Qiu J, et al., Soluble HLA-G expression and
renal graft acceptance. Am J Transplant 2006; 6:2152-6. [0324]
Storkus W J, Zej H J, Salter R D, Lotze M T. Identification of
T-cell epitopes: rapid isolation of class I-presented peptides from
viable cells by mild acid elution. J Immunother Emphasis Tumor
Immunol 1993; 14: 94-103. [0325] Tanabe M, Sekimata M, Ferrone S,
Takiguchi M. Structural and functional analysis of monomorphic
determinants recognized by monoclonal antibodies reacting with the
HLA class I alpha 3 domain. J Immunol 1992; 148:3202-9. [0326]
Tripathi P, Agrawal S. The role of human leukocyte antigen E and
Gin HIV infection. AIDS 2007; 21:1395-404 [0327] Yan W H, HLA-G
expression in cancers: potential role in diagnosis, prognosis and
therapy. Endocr Metab Immune Disord Drug Targets 2011; 11:76-89
Sequence CWU 1
1
104126PRTMus musculus 1Asp Val Leu Met Thr Gln Ile Pro Phe Ser Leu
Pro Val Ser Leu Gly1 5 10 15Asp Gln Ala Ser Ile Ser Cys Arg Ser Ser
20 25211PRTMus musculus 2Gln Ser Ile Val His Arg Ser Gly Asn Thr
Tyr1 5 10317PRTMus musculus 3Leu Glu Trp Tyr Leu Gln Lys Pro Gly
Gln Ser Pro Lys Leu Leu Ile1 5 10 15Tyr436PRTMus musculus 4Asn Arg
Phe Ser Gly Val Pro Asp Arg Phe Ser Gly Ser Gly Ser Gly1 5 10 15Thr
Asp Phe Thr Leu Lys Ile Ser Arg Val Glu Ala Glu Asp Leu Gly 20 25
30Val Tyr Tyr Cys 3559PRTMus musculus 5Phe Gln Gly Ser His Leu Pro
Pro Thr1 569PRTMus musculus 6Phe Gly Gly Thr Thr Leu Glu Ile Lys1
5725PRTMus musculus 7Gln Val Gln Leu Gln Gln Pro Gly Ala Glu Leu
Val Arg Pro Gly Ser1 5 10 15Ser Val Lys Leu Ser Cys Lys Ala Ser 20
2588PRTMus musculus 8Gly Tyr Thr Phe Thr Asp Tyr Trp1 5917PRTMus
musculus 9Met Asp Trp Val Lys Gln Arg Pro Gly Gln Gly Leu Glu Trp
Ile Gly1 5 10 15Thr108PRTMus musculus 10Ile Tyr Pro Ser Asp Ser Ser
Thr1 51138PRTMus musculus 11His Tyr Asn Gln Glu Phe Lys Gly Lys Ala
Thr Met Thr Val Asp Lys1 5 10 15Ser Ser Ser Thr Ala Tyr Met His Leu
Ser Ser Leu Thr Ser Glu Asp 20 25 30Ser Ala Val Tyr Tyr Cys
351213PRTMus musculus 12Ala Arg Glu Gly Leu Ala Gly Val Phe Tyr Phe
Asp Tyr1 5 101311PRTMus musculus 13Trp Gly Gln Gly Thr Thr Leu Thr
Val Ser Ser1 5 101426PRTMus musculus 14Asp Val Leu Met Thr Gln Thr
Pro Leu Ser Leu Pro Val Ser Leu Gly1 5 10 15Asp Gln Ala Ser Ile Ser
Cys Arg Ser Ser 20 251511PRTMus musculus 15Gln Ser Leu Val His Ser
Asn Gly Asn Thr Tyr1 5 101617PRTMus musculus 16Leu His Trp Tyr Leu
Gln Lys Pro Gly Gln Ser Pro Lys Leu Leu Ile1 5 10 15Tyr1736PRTMus
musculus 17Asn Arg Phe Ser Gly Val Pro Asp Arg Phe Ser Gly Ser Gly
Ser Gly1 5 10 15Thr Asp Phe Thr Leu Lys Ile Ser Arg Val Glu Ala Glu
Asp Leu Gly 20 25 30Val Tyr Phe Cys 35189PRTMus musculus 18Ser Gln
Ser Thr His Phe Pro Pro Thr1 51910PRTMus musculus 19Phe Gly Gly Gly
Thr Lys Leu Glu Ile Ile1 5 10209PRTMus musculus 20Ser Gln Ser Thr
His Val Pro Pro Thr1 52110PRTMus musculus 21Phe Gly Ala Gly Thr Lys
Leu Glu Leu Lys1 5 102225PRTMus musculus 22Gln Val Gln Leu Lys Gln
Ser Gly Pro Gln Leu Val Arg Pro Gly Ala1 5 10 15Ser Val Lys Ile Pro
Cys Lys Ala Ser 20 25238PRTMus musculus 23Gly Tyr Ser Phe Thr Asn
Tyr Trp1 52417PRTMus musculus 24Met His Trp Val Lys Gln Arg Pro Gly
Gln Gly Leu Glu Trp Ile Gly1 5 10 15Met258PRTMus musculus 25Ile Ala
Pro Ser Asp Ser Asp Ser1 52638PRTMus musculus 26Arg Leu Asn Gln Asn
Phe Lys Asp Lys Ala Thr Leu Thr Val Asp Lys1 5 10 15Ser Ser Ser Thr
Ala Tyr Met Gln Leu Ser Ser Pro Thr Ser Glu Asp 20 25 30Ser Ala Val
Tyr Tyr Cys 352714PRTMus musculus 27Ala Arg Glu Gly Val Thr Met Ile
Thr Thr Gly Leu Asp Tyr1 5 102811PRTMus musculus 28Trp Gly Gln Gly
Thr Thr Leu Thr Val Ser Ser1 5 1029275PRTHomo sapiens 29Gly Ser His
Ser Met Arg Tyr Phe Ser Ala Ala Val Ser Arg Pro Gly1 5 10 15Arg Gly
Glu Pro Arg Phe Ile Ala Met Gly Tyr Val Asp Asp Thr Gln 20 25 30Phe
Val Arg Phe Asp Ser Asp Ser Ala Cys Pro Arg Met Glu Pro Arg 35 40
45Ala Pro Trp Val Glu Gln Glu Gly Pro Glu Tyr Trp Glu Glu Glu Thr
50 55 60Arg Asn Thr Lys Ala His Ala Gln Thr Asp Arg Met Asn Leu Gln
Thr65 70 75 80Leu Arg Gly Tyr Tyr Asn Gln Ser Glu Ala Ser Ser His
Thr Leu Gln 85 90 95Trp Met Ile Gly Cys Asp Leu Gly Ser Asp Gly Arg
Leu Leu Arg Gly 100 105 110Tyr Glu Gln Tyr Ala Tyr Asp Gly Lys Asp
Tyr Leu Ala Leu Asn Glu 115 120 125Asp Leu Arg Ser Trp Thr Ala Ala
Asp Thr Ala Ala Gln Ile Ser Lys 130 135 140Arg Lys Cys Glu Ala Ala
Asn Val Ala Glu Gln Arg Arg Ala Tyr Leu145 150 155 160Glu Gly Thr
Cys Val Glu Trp Leu His Arg Tyr Leu Glu Asn Gly Lys 165 170 175Glu
Met Leu Gln Arg Ala Asp Pro Pro Lys Thr His Val Thr His His 180 185
190Pro Val Phe Asp Tyr Glu Ala Thr Leu Arg Cys Trp Ala Leu Gly Phe
195 200 205Tyr Pro Ala Glu Ile Ile Leu Thr Trp Gln Arg Asp Gly Glu
Asp Gln 210 215 220Thr Gln Asp Val Glu Leu Val Glu Thr Arg Pro Ala
Gly Asp Gly Thr225 230 235 240Phe Gln Lys Trp Ala Ala Val Val Val
Pro Ser Gly Glu Glu Gln Arg 245 250 255Tyr Thr Cys His Val Gln His
Glu Gly Leu Pro Glu Pro Leu Met Leu 260 265 270Arg Trp Lys
27530275PRTHomo sapiens 30Gly Ser His Ser Leu Lys Tyr Phe His Thr
Ser Val Ser Arg Pro Gly1 5 10 15Arg Gly Glu Pro Arg Phe Ile Ser Val
Gly Tyr Val Asp Asp Thr Gln 20 25 30Phe Val Arg Phe Asp Asn Asp Ala
Ala Ser Pro Arg Met Val Pro Arg 35 40 45Ala Pro Trp Met Glu Gln Glu
Gly Ser Glu Tyr Trp Asp Arg Glu Thr 50 55 60Arg Ser Ala Arg Asp Thr
Ala Gln Ile Phe Arg Val Asn Leu Arg Thr65 70 75 80Leu Arg Gly Tyr
Tyr Asn Gln Ser Glu Ala Gly Ser His Thr Leu Gln 85 90 95Trp Met His
Gly Cys Glu Leu Gly Pro Asp Gly Arg Phe Leu Arg Gly 100 105 110Tyr
Glu Gln Phe Ala Tyr Asp Gly Lys Asp Tyr Leu Thr Leu Asn Glu 115 120
125Asp Leu Arg Ser Trp Thr Ala Val Asp Thr Ala Ala Gln Ile Ser Glu
130 135 140Gln Lys Ser Asn Asp Ala Ser Glu Ala Glu His Gln Arg Ala
Tyr Leu145 150 155 160Glu Asp Thr Cys Val Glu Trp Leu His Lys Tyr
Leu Glu Lys Gly Lys 165 170 175Glu Thr Leu Leu His Leu Glu Pro Pro
Lys Thr His Val Thr His His 180 185 190Pro Ile Ser Asp His Glu Ala
Thr Leu Arg Cys Trp Ala Leu Gly Phe 195 200 205Tyr Pro Ala Glu Ile
Thr Leu Thr Trp Gln Gln Asp Gly Glu Gly His 210 215 220Thr Gln Asp
Thr Glu Leu Val Glu Thr Arg Pro Ala Gly Asp Gly Thr225 230 235
240Phe Gln Lys Trp Ala Ala Val Val Val Pro Ser Gly Glu Glu Gln Arg
245 250 255Tyr Thr Cys His Val Gln His Glu Gly Leu Pro Glu Pro Val
Thr Leu 260 265 270Arg Trp Lys 27531275PRTHomo sapiens 31Gly Ser
His Ser Met Arg Tyr Phe Phe Thr Ser Val Ser Arg Pro Gly1 5 10 15Arg
Gly Glu Pro Arg Phe Ile Ala Val Gly Tyr Val Asp Asp Thr Gln 20 25
30Phe Val Arg Phe Asp Ser Asp Ala Ala Ser Gln Arg Met Glu Pro Arg
35 40 45Ala Pro Trp Ile Glu Gln Glu Gly Pro Glu Tyr Trp Asp Gly Glu
Thr 50 55 60Arg Lys Val Lys Ala His Ser Gln Thr His Arg Val Asp Leu
Gly Thr65 70 75 80Leu Arg Gly Tyr Tyr Asn Gln Ser Glu Ala Gly Ser
His Thr Val Gln 85 90 95Arg Met Tyr Gly Cys Asp Val Gly Ser Asp Trp
Arg Phe Leu Arg Gly 100 105 110Tyr His Gln Tyr Ala Tyr Asp Gly Lys
Asp Tyr Ile Ala Leu Lys Glu 115 120 125Asp Leu Arg Ser Trp Thr Ala
Ala Asp Met Ala Ala Gln Thr Thr Lys 130 135 140His Lys Trp Glu Ala
Ala His Val Ala Glu Gln Leu Arg Ala Tyr Leu145 150 155 160Glu Gly
Thr Cys Val Glu Trp Leu Arg Arg Tyr Leu Glu Asn Gly Lys 165 170
175Glu Thr Leu Gln Arg Thr Asp Ala Pro Lys Thr His Met Thr His His
180 185 190Ala Val Ser Asp His Glu Ala Thr Leu Arg Cys Trp Ala Leu
Ser Phe 195 200 205Tyr Pro Ala Glu Ile Thr Leu Thr Trp Gln Arg Asp
Gly Glu Asp Gln 210 215 220Thr Gln Asp Thr Glu Leu Val Glu Thr Arg
Pro Ala Gly Asp Gly Thr225 230 235 240Phe Gln Lys Trp Ala Ala Val
Val Val Pro Ser Gly Gln Glu Gln Arg 245 250 255Tyr Thr Cys His Val
Gln His Glu Gly Leu Pro Lys Pro Leu Thr Leu 260 265 270Arg Trp Glu
27532275PRTHomo sapiens 32Gly Ser His Ser Met Arg Tyr Phe Tyr Thr
Ser Val Ser Arg Pro Gly1 5 10 15Arg Gly Glu Pro Arg Phe Ile Ser Val
Gly Tyr Val Asp Asp Thr Gln 20 25 30Phe Val Arg Phe Asp Ser Asp Ala
Ala Ser Pro Arg Glu Glu Pro Arg 35 40 45Ala Pro Trp Ile Glu Gln Glu
Gly Pro Glu Tyr Trp Asp Arg Asn Thr 50 55 60Gln Ile Tyr Lys Ala Gln
Ala Gln Thr Asp Arg Glu Ser Leu Arg Asn65 70 75 80Leu Arg Gly Tyr
Tyr Asn Gln Ser Glu Ala Gly Ser His Thr Leu Gln 85 90 95Ser Met Tyr
Gly Cys Asp Val Gly Pro Asp Gly Arg Leu Leu Arg Gly 100 105 110His
Asp Gln Tyr Ala Tyr Asp Gly Lys Asp Tyr Ile Ala Leu Asn Glu 115 120
125Asp Leu Arg Ser Trp Thr Ala Ala Asp Thr Ala Ala Gln Ile Thr Gln
130 135 140Arg Lys Trp Glu Ala Ala Arg Glu Ala Glu Gln Arg Arg Ala
Tyr Leu145 150 155 160Glu Gly Glu Cys Val Glu Trp Leu Arg Arg Tyr
Leu Glu Asn Gly Lys 165 170 175Asp Lys Leu Glu Arg Ala Asp Pro Pro
Lys Thr His Val Thr His His 180 185 190Pro Ile Ser Asp His Glu Ala
Thr Leu Arg Cys Trp Ala Leu Gly Phe 195 200 205Tyr Pro Ala Glu Ile
Thr Leu Thr Trp Gln Arg Asp Gly Glu Asp Gln 210 215 220Thr Gln Asp
Thr Glu Leu Val Glu Thr Arg Pro Ala Gly Asp Arg Thr225 230 235
240Phe Gln Lys Trp Ala Ala Val Val Val Pro Ser Gly Glu Glu Gln Arg
245 250 255Tyr Thr Cys His Val Gln His Glu Gly Leu Pro Lys Pro Leu
Thr Leu 260 265 270Arg Trp Glu 27533274PRTHomo sapiens 33Gly Ser
His Ser Met Arg Tyr Phe Cys Thr Ala Val Ser Arg Pro Gly1 5 10 15Arg
Gly Glu Pro His Phe Ile Ala Val Gly Tyr Val Asp Asp Thr Gln 20 25
30Phe Val Arg Phe Asp Ser Asp Asp Glu Ser Pro Arg Gly Glu Pro Arg
35 40 45Ala Pro Trp Val Glu Arg Lys Gly Pro Glu Tyr Trp Asp Arg Glu
Thr 50 55 60Gln Lys Tyr Lys Pro Gln Ala Gln Thr Asp Arg Val Ser Leu
Arg Asn65 70 75 80Leu Arg Gly Tyr Tyr Asn Gln Ser Glu Ala Gly Ser
His Ile Ile Arg 85 90 95Met Tyr Gly Cys Asp Val Gly Pro Asp Gly Arg
Leu Leu Arg Gly Tyr 100 105 110Asp Gln His Ala Tyr Asp Gly Lys Asp
Tyr Ile Ala Leu Asn Glu Asp 115 120 125Leu Arg Ser Trp Thr Ala Ala
Asn Thr Ala Ala Gln Ile Thr Gln Arg 130 135 140Lys Trp Glu Ala Ala
Arg Glu Ala Glu Gln Leu Arg Ala Tyr Leu Glu145 150 155 160Gly Leu
Cys Val Glu Trp Leu Arg Arg Tyr Leu Lys Asn Gly Lys Glu 165 170
175Thr Leu Gln Gly Ala Glu His Pro Lys Thr His Val Thr His His Pro
180 185 190Val Ser Asp His Glu Ala Thr Leu Arg Cys Trp Ala Leu Gly
Phe Tyr 195 200 205Pro Ala Glu Ile Thr Leu Thr Trp Gln Trp Asp Gly
Glu Asp Gln Thr 210 215 220Gln Asp Thr Glu Leu Val Glu Thr Arg Pro
Ala Gly Asp Gly Thr Phe225 230 235 240Gln Lys Trp Ala Ala Val Val
Val Pro Ser Gly Glu Glu Gln Arg Tyr 245 250 255Thr Cys His Val Gln
His Glu Gly Leu Pro Glu Pro Leu Thr Leu Arg 260 265 270Trp
Glu34275PRTHomo sapiens 34Gly Ser His Ser Met Arg Tyr Phe Tyr Thr
Ala Met Ser Arg Pro Gly1 5 10 15Arg Gly Glu Pro Arg Phe Ile Thr Val
Gly Tyr Val Asp Asp Thr Leu 20 25 30Phe Val Arg Phe Asp Ser Asp Ala
Thr Ser Pro Arg Lys Glu Pro Arg 35 40 45Ala Pro Trp Ile Glu Gln Glu
Gly Pro Glu Tyr Trp Asp Arg Glu Thr 50 55 60Gln Ile Ser Lys Thr Asn
Thr Gln Thr Tyr Arg Glu Asn Leu Arg Thr65 70 75 80Ala Ala Arg Tyr
Tyr Asn Gln Ser Glu Ala Gly Ser His Ile Ile Gln 85 90 95Arg Met Tyr
Gly Cys Asp Val Gly Pro Asp Gly Arg Leu Leu Arg Gly 100 105 110Tyr
Asp Gln Asp Ala Tyr Asp Gly Lys Asp Tyr Ile Ala Leu Asn Glu 115 120
125Asp Leu Ser Ser Trp Thr Ala Ala Asp Thr Ala Ala Gln Ile Thr Gln
130 135 140Arg Lys Trp Glu Ala Ala Arg Val Ala Glu Gln Asp Arg Ala
Tyr Leu145 150 155 160Glu Gly Leu Cys Val Glu Ser Leu Arg Arg Tyr
Leu Glu Asn Gly Lys 165 170 175Glu Thr Leu Gln Arg Ala Asp Pro Pro
Lys Thr His Val Thr His His 180 185 190Pro Ile Ser Asp His Glu Ala
Thr Leu Arg Cys Trp Ser Leu Gly Phe 195 200 205Tyr Pro Ala Glu Ile
Thr Leu Thr Trp Gln Arg Asp Gly Glu Asp Gln 210 215 220Thr Gln Asp
Thr Glu Leu Val Glu Thr Arg Pro Ala Gly Asp Arg Thr225 230 235
240Phe Gln Lys Trp Ala Ala Val Val Val Pro Ser Gly Glu Glu Gln Arg
245 250 255Tyr Thr Cys His Val Gln His Glu Gly Leu Pro Lys Pro Leu
Thr Leu 260 265 270Arg Trp Glu 27535336DNAMus musculus 35gatgttttga
tgacccaaat tccattctcc ctgcctgtca gtcttggaga tcaagcctcc 60atctcttgca
gatctagtca gagcattgta catagaagtg gaaacaccta tttagagtgg
120tacctgcaga agccaggcca gtctccaaag ctcctgatct acaaagtttc
caaccgattt 180tctggggtcc cagacaggtt cagtggcagt ggatcaggga
cagatttcac actcaagatc 240agcagagtgg aggctgagga tctgggagtt
tattactgct ttcaaggttc acatcttcct 300ccgacgttcg gtggaggcac
cacgctggaa atcaaa 33636100PRTMus musculus 36Asp Val Leu Met Thr Gln
Thr Pro Leu Ser Leu Pro Val Ser Leu Gly1 5 10 15Asp Gln Ala Ser Ile
Ser Cys Arg Ser Ser Gln Ser Ile Val His Ser 20 25 30Asn Gly Asn Thr
Tyr Leu Glu Trp Tyr Leu Gln Lys Pro Gly Gln Ser 35 40 45Pro Lys Leu
Leu Ile Tyr Lys Val Ser Asn Arg Phe Ser Gly Val Pro 50 55 60Asp Arg
Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile65 70 75
80Ser Arg Val Glu Ala Glu Asp Leu Gly Val Tyr Tyr Cys Phe Gln Gly
85 90 95Ser His Val Pro 1003712PRTMus musculus 37Trp Thr Phe Gly
Gly Gly Thr Lys Leu Glu Ile Lys1 5 1038360DNAMus musculus
38caggtccaac tgcagcagcc tggggctgaa ctggtgaggc ctgggtcttc agtgaagctg
60tcctgcaagg cttctggcta caccttcacc gactactgga tggattgggt gaagcagagg
120cctggacaag gccttgaatg gattggtacc atttaccctt ctgatagttc
aactcactac 180aatcaagagt tcaagggcaa ggccacaatg actgtagaca
aatcctccag cacagcctac 240atgcatctca gcagcctgac atctgaggac
tctgcggtct attactgtgc aagagaggga 300ctagctgggg tgttctactt
tgactactgg ggccaaggca ccactctcac agtctcctca 3603998PRTMus musculus
39Gln Val Gln Leu Gln Gln Pro Gly Ala Glu Leu Val Arg Pro Gly Ser1
5 10 15Ser Val Lys Leu Ser Cys
Lys Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 20 25 30Trp Met Asp Trp Val
Lys Gln Arg Pro Gly Gln Gly Leu Glu Trp Ile 35 40 45Gly Asn Ile Tyr
Pro Ser Asp Ser Glu Thr His Tyr Asn Gln Lys Phe 50 55 60Lys Asp Lys
Ala Thr Leu Thr Val Asp Lys Ser Ser Ser Thr Ala Tyr65 70 75 80Met
Gln Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Tyr Cys 85 90
95Ala Arg4015PRTMus musculus 40Tyr Phe Asp Tyr Trp Gly Gln Gly Thr
Thr Leu Thr Val Ser Ser1 5 10 1541336DNAMus musculus 41gatgttttga
tgacccaaac tccactctcc ctgcctgtca gtcttggaga tcaagcctcc 60atctcttgca
gatctagtca gagccttgta cacagtaatg gaaacaccta tttacattgg
120tacctgcaga agccaggcca gtctccaaag ctcctgatct acaaagtctc
caaccgattt 180tctggggtcc ctgacaggtt cagtggcagt ggatcaggga
cagatttcac actcaagatc 240agcagagtgg aggctgagga tctgggagtt
tatttctgct ctcaaagtac acattttcct 300ccgacgttcg gtggaggcac
caagctggaa atcata 33642100PRTMus musculus 42Asp Val Val Met Thr Gln
Thr Pro Leu Ser Leu Pro Val Ser Leu Gly1 5 10 15Asp Gln Ala Ser Ile
Ser Cys Arg Ser Ser Gln Ser Leu Val His Ser 20 25 30Asn Gly Asn Thr
Tyr Leu His Trp Tyr Leu Gln Lys Pro Gly Gln Ser 35 40 45Pro Lys Leu
Leu Ile Tyr Lys Val Ser Asn Arg Phe Ser Gly Val Pro 50 55 60Asp Arg
Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile65 70 75
80Ser Arg Val Glu Ala Glu Asp Leu Gly Val Tyr Phe Cys Ser Gln Ser
85 90 95Thr His Val Pro 1004312PRTMus musculus 43Trp Thr Phe Gly
Gly Gly Thr Lys Leu Glu Ile Lys1 5 1044372DNAMus musculus
44gatgttttga tgacccaaac tccactctcc ctgcctgtca gtcttggaga tcaagcctcc
60atctcttgca gatctagtca gagccttgta cacagtaatg gaaacaccta tttacattgg
120tacctgcaga agccaggcca gtctccaaag ctcctgatct acaaagtttc
caaccgattt 180tctggggtcc cagacaggtt cagtggcagt ggatcaggga
cagatttcac actcaagatc 240agcagagtgg aggctgagga tctgggagtt
tatttctgct ctcaaagtac acatgttcct 300cccacgttcg gtgctgggac
caagctggag ctgaaacggg ctgatgctgc accaactgta 360tccgcggccg ca
3724512PRTMus musculus 45Leu Thr Phe Gly Ala Gly Thr Lys Leu Glu
Leu Lys1 5 1046363DNAMus musculus 46caggtgcagc tgaagcagtc
tgggcctcag ctggttaggc ctggggcttc agtgaagata 60ccctgcaagg cttctggtta
ctcattcacc aactactgga tgcactgggt gaagcagagg 120cctggacaag
gtcttgagtg gattggcatg attgctcctt ccgatagtga tagtaggtta
180aatcagaatt tcaaggacaa ggccacattg actgtagaca aatcctccag
cacagcctac 240atgcaactca gcagcccgac atctgaggac tctgcggtct
attactgtgc aagagaggga 300gttacaatga taacgacggg ccttgactac
tggggccaag gcaccactct cacagtctcc 360tca 3634798PRTMus musculus
47Gln Val Gln Leu Gln Gln Pro Gly Ala Glu Leu Val Lys Pro Gly Ala1
5 10 15Ser Val Lys Ile Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Ser
Tyr 20 25 30Trp Met Asn Trp Val Lys Gln Arg Pro Gly Gln Gly Leu Glu
Trp Ile 35 40 45Gly Glu Ile Asp Pro Ser Asp Ser Tyr Thr Asn Asn Asn
Gln Lys Phe 50 55 60Lys Asp Lys Ala Thr Leu Thr Val Asp Lys Ser Ser
Ser Thr Ala Tyr65 70 75 80Met Gln Leu Ser Ser Leu Thr Ser Glu Asp
Ser Ala Val Tyr Tyr Cys 85 90 95Ala Arg488PRTMus musculus 48Pro Thr
Ile Val Thr Ile Val Thr1 54915PRTArtificial SequenceImmunogenic
peptideMISC_FEATURE(1)..(1)Xaa at position 1 is absent, cysteine or
valineMISC_FEATURE(15)..(15)Xaa at position 15 is absent or
cysteine 49Xaa Thr His His Pro Val Phe Asp Tyr Glu Ala Thr Leu Arg
Xaa1 5 10 15504PRTArtificial Sequencefragment of immunogenic
peptide 50Lys Thr His Val1515PRTArtificial Sequencefragment of
immunogenic sequence 51Cys Lys Thr His Val1 55215PRTArtificial
Sequenceimmunogenic peptide 52Cys Thr His His Pro Val Phe Asp Tyr
Glu Ala Thr Leu Arg Cys1 5 10 155319PRTArtificial
Sequenceimmunogenic peptide 53Cys Lys Thr His Val Thr His His Pro
Val Phe Asp Tyr Glu Ala Thr1 5 10 15Leu Arg Cys5413PRTHomo sapiens
54Thr His His Pro Val Phe Asp Tyr Glu Ala Thr Leu Arg1 5
105514PRTHomo sapiens 55Thr His His Pro Val Phe Asp Tyr Glu Ala Thr
Leu Arg Cys1 5 105615PRTHomo sapiens 56Val Thr His His Pro Val Phe
Asp Tyr Glu Ala Thr Leu Arg Cys1 5 10 155714PRTHomo sapiens 57Val
Thr His His Pro Val Phe Asp Tyr Glu Ala Thr Leu Arg1 5
105814PRTArtificial Sequenceimmunogenic peptide 58Cys Thr His His
Pro Val Phe Asp Tyr Glu Ala Thr Leu Arg1 5 105917PRTHomo sapiens
59Lys Thr His Val Thr His His Pro Val Phe Asp Tyr Glu Ala Thr Leu1
5 10 15Arg6018PRTHomo sapiens 60Lys Thr His Val Thr His His Pro Val
Phe Asp Tyr Glu Ala Thr Leu1 5 10 15Arg Cys6118PRTArtificial
Sequenceimmunogenic peptide 61Cys Lys Thr His Val Thr His His Pro
Val Phe Asp Tyr Glu Ala Thr1 5 10 15Leu Arg6215PRTArtificial
Sequencemutant peptide 62Cys Thr His His Pro Val Ala Asp Ala Glu
Ala Thr Leu Arg Cys1 5 10 1563111PRTMus musculus 63Asp Val Leu Met
Thr Gln Ile Pro Phe Ser Leu Pro Val Ser Leu Gly1 5 10 15Asp Gln Ala
Ser Ile Ser Cys Arg Ser Ser Gln Ser Ile Val His Arg 20 25 30Ser Gly
Asn Thr Tyr Leu Glu Trp Tyr Leu Gln Lys Pro Gly Gln Ser 35 40 45Pro
Lys Leu Leu Ile Tyr Lys Val Ser Asn Arg Phe Ser Gly Val Pro 50 55
60Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile65
70 75 80Ser Arg Val Glu Ala Glu Asp Leu Gly Val Tyr Tyr Cys Phe Gln
Gly 85 90 95Ser His Leu Pro Pro Thr Phe Gly Gly Thr Thr Leu Glu Ile
Lys 100 105 11064120PRTMus musculus 64Gln Val Gln Leu Gln Gln Pro
Gly Ala Glu Leu Val Arg Pro Gly Ser1 5 10 15Ser Val Lys Leu Ser Cys
Lys Ala Ser Gly Tyr Thr Phe Thr Asp Tyr 20 25 30Trp Met Asp Trp Val
Lys Gln Arg Pro Gly Gln Gly Leu Glu Trp Ile 35 40 45Gly Thr Ile Tyr
Pro Ser Asp Ser Ser Thr His Tyr Asn Gln Glu Phe 50 55 60Lys Gly Lys
Ala Thr Met Thr Val Asp Lys Ser Ser Ser Thr Ala Tyr65 70 75 80Met
His Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Tyr Cys 85 90
95Ala Arg Glu Gly Leu Ala Gly Val Phe Tyr Phe Asp Tyr Trp Gly Gln
100 105 110Gly Thr Thr Leu Thr Val Ser Ser 115 12065112PRTMus
musculus 65Asp Val Leu Met Thr Gln Thr Pro Leu Ser Leu Pro Val Ser
Leu Gly1 5 10 15Asp Gln Ala Ser Ile Ser Cys Arg Ser Ser Gln Ser Leu
Val His Ser 20 25 30Asn Gly Asn Thr Tyr Leu His Trp Tyr Leu Gln Lys
Pro Gly Gln Ser 35 40 45Pro Lys Leu Leu Ile Tyr Lys Val Ser Asn Arg
Phe Ser Gly Val Pro 50 55 60Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr
Asp Phe Thr Leu Lys Ile65 70 75 80Ser Arg Val Glu Ala Glu Asp Leu
Gly Val Tyr Phe Cys Ser Gln Ser 85 90 95Thr His Phe Pro Pro Thr Phe
Gly Gly Gly Thr Lys Leu Glu Ile Ile 100 105 11066112PRTMus musculus
66Asp Val Leu Met Thr Gln Thr Pro Leu Ser Leu Pro Val Ser Leu Gly1
5 10 15Asp Gln Ala Ser Ile Ser Cys Arg Ser Ser Gln Ser Leu Val His
Ser 20 25 30Asn Gly Asn Thr Tyr Leu His Trp Tyr Leu Gln Lys Pro Gly
Gln Ser 35 40 45Pro Lys Leu Leu Ile Tyr Lys Val Ser Asn Arg Phe Ser
Gly Val Pro 50 55 60Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe
Thr Leu Lys Ile65 70 75 80Ser Arg Val Glu Ala Glu Asp Leu Gly Val
Tyr Phe Cys Ser Gln Ser 85 90 95Thr His Val Pro Pro Thr Phe Gly Ala
Gly Thr Lys Leu Glu Leu Lys 100 105 11067121PRTMus musculus 67Gln
Val Gln Leu Lys Gln Ser Gly Pro Gln Leu Val Arg Pro Gly Ala1 5 10
15Ser Val Lys Ile Pro Cys Lys Ala Ser Gly Tyr Ser Phe Thr Asn Tyr
20 25 30Trp Met His Trp Val Lys Gln Arg Pro Gly Gln Gly Leu Glu Trp
Ile 35 40 45Gly Met Ile Ala Pro Ser Asp Ser Asp Ser Arg Leu Asn Gln
Asn Phe 50 55 60Lys Asp Lys Ala Thr Leu Thr Val Asp Lys Ser Ser Ser
Thr Ala Tyr65 70 75 80Met Gln Leu Ser Ser Pro Thr Ser Glu Asp Ser
Ala Val Tyr Tyr Cys 85 90 95Ala Arg Glu Gly Val Thr Met Ile Thr Thr
Gly Leu Asp Tyr Trp Gly 100 105 110Gln Gly Thr Thr Leu Thr Val Ser
Ser 115 1206826PRTMus musculus 68Glu Asn Val Leu Thr Gln Ser Pro
Ala Ile Met Ala Ala Ser Leu Gly1 5 10 15Glu Lys Val Thr Met Thr Cys
Ser Ala Ser 20 25697PRTMus musculus 69Ser Ser Val Ser Ser Asn Phe1
57017PRTMus musculus 70Leu His Trp Tyr Gln Gln Lys Ser Gly Thr Ser
Pro Lys Leu Trp Ile1 5 10 15Tyr7136PRTMus musculus 71Asn Leu Ala
Ser Gly Val Pro Ala Arg Phe Ser Gly Ser Gly Thr Gly1 5 10 15Ile Ser
Tyr Ser Leu Thr Val Ser Asn Met Glu Ala Glu Asn Asp Ala 20 25 30Ala
Tyr Tyr Cys 35729PRTMus musculus 72Gln Gln Trp Asn Ala Tyr Pro Phe
Thr1 57325PRTMus musculus 73Glu Val Lys Leu Glu Glu Ser Gly Gly Gly
Leu Val Gln Pro Gly Gly1 5 10 15Ser Met Lys Leu Ser Cys Val Ala Ser
20 25748PRTMus musculus 74Gly Phe Thr Phe Ser Ser Tyr Trp1
57517PRTMus musculus 75Leu Ser Trp Val Arg Gln Ser Pro Glu Lys Gly
Leu Glu Trp Val Ala1 5 10 15Glu7610PRTMus musculus 76Val Arg Leu
Lys Ser Asp Asn Tyr Ala Thr1 5 107738PRTMus musculus 77Ser Tyr Ala
Glu Ser Val Lys Gly Lys Phe Thr Ile Ser Arg Asp Asp1 5 10 15Ala Asn
Ser Arg Leu Tyr Leu Gln Met Asn Ser Leu Arg Pro Glu Asp 20 25 30Thr
Gly Ile Tyr Tyr Cys 35785PRTMus musculus 78Thr Thr Gly Asp Tyr1
57925PRTMus musculus 79Asp Val Val Met Thr Gln Ile Pro Leu Ser Leu
Pro Val Ser Leu Gly1 5 10 15Asp Gln Ala Ser Ile Ser Cys Arg Ser 20
258011PRTMus musculus 80Gln Ser Leu Val Asn Ser Asn Gly Asn Thr
Leu1 5 10819PRTMus musculus 81Ser Gln Ser Thr His Val Pro Trp Thr1
58210PRTMus musculus 82Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys1 5
10838PRTMus musculus 83Gly Leu Thr Phe Ser Ser Tyr Trp1 58417PRTMus
musculus 84Met Ser Trp Val Arg Gln Ser Pro Glu Lys Gly Leu Glu Trp
Val Ala1 5 10 15Glu8510PRTMus musculus 85Ile Arg Leu Arg Ser Asp
Asn Tyr Val Lys1 5 108638PRTMus musculus 86Gln Tyr Ala Asp Ser Val
Lys Gly Arg Phe Thr Ile Ser Arg Asp Asp1 5 10 15Ser Lys Gly Arg Leu
Tyr Leu Gln Met Asn Arg Leu Arg Gly Asp Asp 20 25 30Thr Gly Ile Tyr
Phe Cys 358711PRTMus musculus 87Gln Thr Ile Val His Ser Asn Gly Asn
Thr Tyr1 5 10889PRTMus musculus 88Phe Gln Gly Ser His Val Pro Pro
Thr1 58925PRTMus musculus 89Glu Val Gln Leu Gln Gln Ser Gly Ala Glu
Leu Val Lys Pro Gly Thr1 5 10 15Ser Val Lys Leu Ser Cys Lys Ala Ser
20 25908PRTMus musculus 90Gly Tyr Thr Phe Thr Arg Asn Trp1
59117PRTMus musculus 91Ile Thr Trp Val Arg Leu Arg Pro Gly Gln Gly
Leu Glu Trp Ile Gly1 5 10 15Asp928PRTMus musculus 92Ile Tyr Pro Gly
Asp Ala Ser Thr1 59338PRTMus musculus 93His Tyr Asn Gly Lys Phe Lys
Asn Lys Ala Thr Leu Thr Val Asp Thr1 5 10 15Ser Ser Ser Thr Ala Tyr
Leu Gln Val Ser Ser Leu Thr Ser Glu Asp 20 25 30Ser Ala Val Tyr Tyr
Cys 359413PRTMus musculus 94Ala Arg Glu Gln Val Gln Phe Ala Met Phe
Phe Asp Val1 5 109511PRTMus musculus 95Trp Gly Thr Gly Ala Thr Val
Thr Val Ser Ser1 5 109625PRTMus musculus 96Gln Val Gln Leu Gln Gln
Pro Arg Ala Glu Leu Val Lys Pro Gly Ala1 5 10 15Ser Val Lys Met Ser
Cys Lys Ala Ser 20 25978PRTMus musculus 97Gly Tyr Thr Phe Ala Arg
Tyr Trp1 59817PRTMus musculus 98Ile Ser Trp Leu Lys Leu Arg Pro Gly
Gln Gly Leu Glu Trp Ile Gly1 5 10 15Asp998PRTMus musculus 99Ile Tyr
Pro Gly Asp Asp Ser Thr1 510038PRTMus musculus 100His Tyr Asn Gly
Lys Phe Lys Asn Lys Ala Thr Leu Thr Val Asp Thr1 5 10 15Ser Thr Ser
Thr Ala Tyr Ile Gln Leu Ser Ser Leu Thr Ser Glu Asp 20 25 30Ser Ala
Val Tyr Tyr Cys 3510111PRTMus musculus 101Gln Ser Ile Val His Ser
Asn Gly Asn Thr Tyr1 5 1010238PRTMus musculus 102His Tyr Asn Gln
Glu Phe Lys Gly Lys Ala Thr Met Thr Val Asp Lys1 5 10 15Ser Ser Ser
Thr Ala Tyr Met His Leu Gly Ser Leu Thr Ser Glu Asp 20 25 30Ser Ala
Val Tyr Tyr Cys 3510318PRTartificialImmunogenic
peptideMISC_FEATURE(18)..(18)Xaa at position 18 is absent or
cysteine 103Lys Thr His Val Thr His His Pro Val Phe Asp Tyr Glu Ala
Thr Leu1 5 10 15Arg Xaa10419PRTartificialImmunogenic
peptideMISC_FEATURE(19)..(19)Xaa at position 19 is absent or
cysteine 104Cys Lys Thr His Val Thr His His Pro Val Phe Asp Tyr Glu
Ala Thr1 5 10 15Leu Arg Xaa
* * * * *