Patent ID: 7183376

Claim:
An isolated or recombinant polypeptide variant of an extracellular domain of a wild-type primate B7-1 comprising a polypeptide sequence that has at least 95% identity to the polypeptide sequence of the extracellular domain of the wild-type primate B7-1 and differs from the polypeptide sequence of the extracellular domain of the wild-type primate B7-1 by the substitution of an amino acid other than alanine at an amino acid residue position corresponding to position 65 of the polypeptide sequence of wild-type human B7-1 (SEQ ID NO:278), wherein said polypeptide variant has a CTLA-4/CD28 binding affinity ratio greater than the CTLA-4/CD28 binding affinity ratio of the extracellular domain of the wild-type primate B7-1.