Humanized antibodies to ca215

Abstract

Provided herein are humanized forms of murine RP215 monoclonal antibodies and methods of using the same. These humanized RP215 monoclonal antibodies were characterized in terms of their respective affinity and specificity to the corresponding tumor-associated antigen, CA215, and shown to be comparable to those of murine RP215.

1 . A recombinant expression system which comprises a nucleotide sequence encoding a humanized monoclonal antibody (mAb) or antigen-binding fragment thereof that reacts specifically with a CA215, and
 that binds to the CA215 with an affinity substantially equivalent to that of RP215,   which mAb comprises the CDR regions inherent in one of the heavy chain variable regions set forth in SEQ ID NOS:24-26 and in one of the light chain variable regions set forth in SEQ ID NO:28 or 29 according to the numbering system of either Kabat or Clothia;   said encoding nucleotide sequence operably linked to a heterologous promoter.   
     
     
         2 . The expression system of  claim 1 , wherein in said mAb or fragment:
 a) the CDR1 region of the heavy chain is DYWMH (SEQ ID NO:1); and   b) the CDR2 region of the heavy chain is AIDTSDSYTRYAQKFQG (SEQ ID NO:2) or GIDTSDSYTRYAQKFQG (SEQ ID NO:3); and   c) the CDR3 region of the heavy chain is SIYD (SEQ ID NO:4); and   d) the CDR1 region of the light chain is KSSQSLLNSSNQKSYLA (SEQ ID NO:5); and   e) the CDR2 region of the light chain is FASTRES (SEQ ID NO:6); and   f) the CDR3 region of light chain is QGHYSTPST (SEQ ID NO:7).   
     
     
         3 . A recombinant expression system which comprises a nucleotide sequence encoding an mAb or antigen-binding fragment thereof which comprises the variable regions of
 VH1 (SEQ ID NO:24)+VL1 (SEQ ID NO:28); VH1 (SEQ ID NO:24)+VL2 (SEQ ID NO:29);   VH2 (SEQ ID NO:25)+VL1 (SEQ ID NO:28); VH2 (SEQ ID NO:25)+VL2 (SEQ ID NO:29);   VH3 (SEQ ID NO:26)+VL1 (SEQ ID NO:28); or VH3 (SEQ ID NO:26)+VL2 (SEQ ID NO:29);   said encoding nucleotide sequence operably linked to a heterologous promoter.   
     
     
         4 . The expression system of  claim 1  which encodes a complete antibody. 
     
     
         5 . The expression system of  claim 1  which encodes a single-chain antibody. 
     
     
         6 . The expression system of  claim 3  which encodes a complete antibody. 
     
     
         7 . The expression system of  claim 3  which encodes a single-chain antibody. 
     
     
         8 . Recombinant host cells or immortalized cells that produce an mAb or antigen-binding fragment thereof that reacts specifically with a CA215, and
 that binds to the CA215 with an affinity substantially equivalent to that of RP215,   which mAb comprises the CDR regions inherent in one of the heavy chain variable regions set forth in SEQ ID NOS:24-26 and in one of the light chain variable regions set forth in SEQ ID NO:28 or 29 according to the numbering system of either Kabat or Clothia.   
     
     
         9 . The cells of  claim 8 , wherein in said mAb or fragment:
 a) the CDR1 region of the heavy chain is DYWMH (SEQ ID NO:1); and   b) the CDR2 region of the heavy chain is AIDTSDSYTRYAQKFQG (SEQ ID NO:2) or GIDTSDSYTRYAQKFQG (SEQ ID NO:3); and   c) the CDR3 region of the heavy chain is SIYD (SEQ ID NO:4); and   d) the CDR1 region of the light chain is KSSQSLLNSSNQKSYLA (SEQ ID NO:5); and   e) the CDR2 region of the light chain is FASTRES (SEQ ID NO:6); and   f) the CDR3 region of light chain is QGHYSTPST (SEQ ID NO:7).   
     
     
         10 . The cells of  claim 8  that are contained in a transgenic non-human animal or transgenic plant. 
     
     
         11 . A method to produce a humanized mAb or fragment that reacts specifically with CA215 which method comprises culturing the cells of  claim 8  and recovering said mAb or fragment. 
     
     
         12 . Recombinant host cells or immortalized cells that produce an mAb or antigen-binding fragment which comprises the variable regions of
 VH1 (SEQ ID NO:24)+VL1 (SEQ ID NO:28); VH1 (SEQ ID NO:24)+VL2 (SEQ ID NO:29);   VH2 (SEQ ID NO:25)+VL1 (SEQ ID NO:28); VH2 (SEQ ID NO:25)+VL2 (SEQ ID NO:29);   VH3 (SEQ ID NO:26)+VL1 (SEQ ID NO:28); or VH3 (SEQ ID NO:26)+VL2 (SEQ ID NO:29).   
     
     
         13 . The cells of  claim 12  that are contained in a transgenic non-human animal or transgenic plant. 
     
     
         14 . A method to produce a humanized mAb or fragment that reacts specifically with CA215 which method comprises culturing the cells of  claim 12  and recovering said mAb or fragment.