Novel polypeptides involved in immune response

Abstract

Novel polypeptides which comprise a receptor-ligand pair involved in T-cell activation are disclosed. Nucleic acid molecules encoding said polypeptides, and vectors and host cells for expressing same are also disclosed. The polypeptides, or agonists and antagonists thereof, are used to treat T-cell mediated disorders.

1 - 31 . (canceled) 
     
     
         32 . An antibody or fragment thereof which binds to a B7RP1 polypeptide as set forth in  FIG. 12A  (SEQ ID NO:17) or a mature form thereof. 
     
     
         33 . An antibody or fragment thereof which binds to a B7RP1 polypeptide as set forth in  FIG. 3A  (SEQ ID NO:12) or a mature form thereof. 
     
     
         34 . An antibody or fragment thereof which specifically binds to a mature form of a B7RP1 polypeptide as set forth in  FIG. 3A  (SEQ ID NO:12) or  FIG. 12A  (SEQ ID NO:17). 
     
     
         35 . The antibody or fragment of  claim 34  which binds to a membrane-associated form of a B7RP1 polypeptide as set forth in  FIG. 3A  (SEQ ID NO:12) or  FIG. 12A  (SEQ ID NO:17). 
     
     
         36 . The antibody or fragment of  claim 34  which binds to a soluble form of a B7RP1 polypeptide as set forth in  FIG. 3A  (SEQ ID NO:12) or  FIG. 12A  (SEQ ID NO:17). 
     
     
         37 . The antibody or fragment of  claim 34  which binds to an extracellular domain, or fragment thereof, of a B7RP1 polypeptide as set forth in  FIG. 3A  (SEQ ID NO:12) or  FIG. 12A  (SEQ ID NO:17). 
     
     
         38 . The antibody or fragment of  claim 32  which partially or completely blocks the binding of B7RP1 to CRP1. 
     
     
         39 . The antibody or fragment of  claim 32  which increases B7RP-1 mediated T cell costimulatory activity. 
     
     
         40 . The antibody or fragment of  claim 32  which decreases B7RP-1 mediated T cell costimulatory activity. 
     
     
         41 . The antibody or fragment of  claim 32  which partially or completely inhibits B7RP-1 mediated T cell costimulatory activity. 
     
     
         42 . An antibody or fragment thereof which binds to a polypeptide, or a mature form thereof, encoded by the nucleotide sequence as set forth in  FIG. 3A  (SEQ ID NO: 11) or  FIG. 12A  (SEQ ID NO: 16). 
     
     
         43 . An antibody or fragment which binds to a soluble form of B7RP1, wherein the soluble form of B7RP1, or a mature form thereof, is encoded by the nucleic acid as set forth in  FIG. 12A  (SEQ ID NO:16). 
     
     
         44 . The antibody of  claims 32  or  43  which is a monoclonal antibody. 
     
     
         45 . The antibody of  claims 32  or  43  which is selected from a chimeric antibody, a single chain antibody, a bispecific antibody, a CDR-grafted antibody or a humanized antibody. 
     
     
         46 . The antibody of  claims 32  or  43  which is a human antibody. 
     
     
         47 . A pharmaceutical composition comprising the antibody of  claims 32  or  43  and a carrier, diluent, and/or excipient.