ANTI HLA-G SPECIFIC ANTIBODIES
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 a3 domain of HLA-G protein. The invention further relates to the immunogenic peptide, and methods for producing said anti-HLA-G specific antibodies. A particular embodiment refers to the monoclonal antibody with the arbitrary designation 15E7 for which the sequence is provided. Also a anti-HLA-G single-chain antibody gene library was generated and six specific binders were identified from that library.
1 .- 16 . (canceled)
17 . An isolated peptide consisting of sequence X1-THHPVFDYEATLR-X2 (SEQ ID NO: 49) or KTHVTHHPVFDYEATLR-X2 (SEQ ID NO: 103) or CKTHVTHHPVFDYEATLR-X2 (SEQ ID NO: 104), wherein X1 is absent, or is cysteine, or is valine, and X2 is absent or is cysteine.
18 . The peptide of claim 17 , wherein the peptide is
(a) circular and consists of a sequence CTHHPVFDYEATLRC (SEQ ID NO: 52) or CKTHVTHHPVFDYEATLRC (SEQ ID NO: 53), wherein a disulfide bond links the N-term and C-term Cysteine residues; or
(b) is linear and consists of:
(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;
or
(SEQ ID NO: 61)
CKTHVTHHPVFDYEATLR.
19 . An anti-HLA-G antibody which specifically recognizes the peptide as defined in claim 17 .
20 . The antibody of claim 19 , wherein the antibody is a monoclonal antibody.
21 . The antibody of claim 19 , wherein the antibody is a full-length antibody, an antigen-binding fragment thereof or a bispecific antibody.
22 . The antibody of claim 19 , wherein the antibody is a scFv (single-chain variable fragment).
23 . The antibody of claim 19 , comprising:
(a) a heavy chain variable region (VH), comprising 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
(b) a light chain variable region (VL), comprising 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.
24 . The antibody of claim 19 comprising
(a) a heavy chain variable region (VH) comprising SEQ ID NO: 64 or a homologous sequence showing more than 80% identity with SEQ ID NO: 64; and/or
(b) a light chain variable region (VL), comprising SEQ ID NO: 63 or a homologous sequence showing more than 80% identity with SEQ ID NO: 63.
25 . The antibody of claim 19 , wherein the antibody is a full-length immunoglobulin G comprising 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.
26 . The antibody of claim 19 , wherein the antibody is selected from the group consisting of a mouse antibody, a chimeric antibody, a humanized antibody, and a human antibody.
27 . 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 of claim 19 .
28 . A vector comprising the nucleic acid of claim 27 .
29 . A host cell comprising the nucleic acid of claim 27 .
30 . A method for producing an anti-HLA-G monoclonal antibody, comprising culturing the host cell of claim 29 under conditions allowing for expression of the antibody.
31 . A conjugate comprising the antibody of claim 19 , linked to a cytotoxic agent.
32 . A method for treating a cancer or a viral infection in a subject in need thereof, comprising administering to the subject in need thereof the antibody of claim 19 .
33 . A method for treating a cancer or a viral infection in a subject in need thereof, comprising administering to the subject in need thereof the conjugate of claim 31 .
34 . An in vitro diagnostic method for detecting or monitoring HLA-G in a biological sample, comprising contacting said biological sample with the antibody of claim 19 .
35 . A diagnostic kit comprising the antibody of claim 19 .