Polyspecific binding molecules and uses thereof

Abstract

The present invention relates to polyspecific binding molecules and particularly single-chain polyspecific binding molecules that include at least one single-chain T-cell receptor (sc-TCR) covalently linked through a peptide linker sequence to at least one single-chain antibody (sc-Ab). Further disclosed are methods and compositions for testing and using the molecules.

1 - 45 . (canceled) 
     
     
         46 . A method for preventing or treating a cancer in a mammal in which the cancer features pHLA-expressing tumor cells, the method comprising:
 a) administering to the mammal a single-chain polyspecific binding protein comprising at least one single-chain T-Cell receptor (sc-TCR) and at least one single-chain Fv (sc-Fv), wherein the sc-TCR specifically binds to a HLA complexed with a known peptide antigen on tumor cells and the sc-Fv specifically binds CD3 on the surface of immune cells, and wherein the sc-TCR comprises a V-β chain and a V-α chain covalently linked by a peptide linker and further comprises a C-β chain or fragment thereof fused to the C-terminus of the V-β chain;   b) forming a specific binding complex through the single-chain polyspecific binding protein interactions with the known peptide antigen HLA complex on the tumor cells and with the CD3 molecule on the immune cells sufficient to activate the immune cells; and   c) damaging or killing the tumor cells with the activated immune cells sufficient to prevent or treat the cancer in the mammal.   
     
     
         47 . (canceled) 
     
     
         48 . The method of  claim 46 , wherein the peptide linker links the C-terminus of the V-α chain to the N-terminus of the V-β chain. 
     
     
         49 . The method of  claim 46 , wherein the peptide linker comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 
     
     
         50 . The method of  claim 46 , wherein the peptide linker consists of between 5 and 25 amino acids. 
     
     
         51 . The method of  claim 46 , wherein the sc-TCR further comprises a TCR C-α chain or fragment thereof fused to the C-terminus of the V-α chain and the N-terminus of the peptide linker. 
     
     
         52 . The method of  claim 46 , wherein the sc-TCR and the sc-Fv are adjoined by a peptide linker. 
     
     
         53 . The method of  claim 52 , wherein the peptide linker adjoining the sc-TCR and the sc-Fv comprises the amino acids sequence of SEQ ID NO: 1 or SEQ ID NO: 4. 
     
     
         54 . The method of  claim 46 , wherein the sc-Fv is humanized. 
     
     
         55 . The method of  claim 46 , wherein a C-0 chain is a human C-0 chain. 
     
     
         56 . The method of  claim 46 , wherein the immune cells are cytotoxic T lymphocytes. 
     
     
         57 . The method of  claim 46 , wherein the tumor cells comprise HLA-A2-peptide antigen complexes and the peptide antigen is a peptide fragment of the human wild-type tumor suppressor protein p53 restricted by HLA-A2. 
     
     
         58 . The method of  claim 46 , wherein the tumor cells comprise HLA-A2-peptide antigen complexes and the peptide antigen is a peptide fragment of the HER-2 restricted by HLA-A2. 
     
     
         59 . The method of  claim 46 , wherein the mammal is a human.