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 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 .