Patent ID: 8252727

Claim:
A method for producing a variant Fc region polypeptide having a desired modified effector function, the method comprising: (a) producing a library of variant Fc molecules from Fc nucleic acids each encoding a CH2 domain and/or a CH3 domain, the domains encoded in the context of an intact antibody or a fragment thereof, wherein the variant Fc molecules are generated by: (i) hybridizing nucleic acids encoding a first CH2 domain and nucleic acids encoding a second CH2 domain and/or hybridizing nucleic acids encoding a first CH3 domain and nucleic acids encoding a second CH3 domain from the Fc nucleic acids, and (ii) extending the resulting hybridized nucleic acids using a polymerase; (b) expressing the library to produce variant Fc region polypeptides; (c) screening the library of variant Fc region polypeptides to identify an expressed variant Fc region polypeptide having a modified effector function; and (d) repeating steps (a) through (c) one or more times until the expressed variant Fc region polypeptide has acquired the desired modified effector function.