HUMAN ANTIBODIES AND PROTEINS
The present invention provides composite proteins, including antibodies, which show reduced immunogenicity. In particular, composite antibodies for use in humans are provided, in particular antibodies which have been modified to remove one or more T-cell epitopes. Methods for generating such proteins are also provided.
1 . A modified antibody or antigen-binding fragment thereof wherein the heavy and light chain variable regions of the modified antibody or antigen-binding fragment are each composed of two or more segments of amino acid sequence from one or more other antibodies or antigen-binding fragments, whereby the segments are neither whole CDRs nor framework regions.
2 - 36 . (canceled)
37 . A method for screening composite antibody variable regions comprising:
generating a library of genes encoding composite antibody variable regions derived from multiple segments of amino acid sequence of 2 to 31 amino acids long from other antibodies or antigen-binding fragments, wherein the multiple segments are neither whole CDRs nor whole framework regions;
screening the composite antibody variable regions to avoid T cell epitopes; and
expressing at least a portion of the library and screening the expressed antibody variable regions for binding to one or more antigens of interest.
38 . The method of claim 37 , wherein the multiple segments of amino acid sequence are derived from human antibodies.
39 . The method of claim 37 , wherein the expressed antibody variable regions form part of expressed antibodies.
40 . The method of claim 37 , wherein the expressed antibody variable regions form part of expressed antigen-binding fragments.
41 . The method of claim 40 , wherein the expressed antigen-binding fragments are selected from Fv's, Fab's, Fab2's, SCA's, single domain antibodies, and multimeric derivatives of each of these.
42 . A method for producing copies of a composite antibody variable region of interest comprising:
generating a library of genes encoding composite antibody variable regions derived from multiple segments of amino acid sequence of 2 to 31 amino acids long from other antibodies or antigen-binding fragments, wherein the multiple segments are neither whole CDRs nor whole framework regions;
screening the composite antibody variable regions to avoid T cell epitopes;
expressing at least a portion of the library and screening the expressed antibody variable regions for binding to one or more antigens of interest;
identifying an antibody variable region of interest; and
producing additional copies of the identified antibody variable region of interest.
43 . The method of claim 42 , wherein the multiple segments of amino acid sequence are derived from human antibodies.
44 . The method of claim 42 , wherein the additional copies of the identified antibody variable region of interest form part of produced antibodies.
45 . The method of claim 42 , wherein the additional copies of the identified antibody variable region of interest form part of produced antigen-binding fragments.
46 . The method of claim 45 , wherein the produced antigen-binding fragments are selected from Fv's, Fab's, Fab2's, SCA's, single domain antibodies, and multimeric derivatives of each of these.
47 . The method of claim 44 , wherein the produced antibodies comprise one or more regulatory T cell epitopes which suppress immune reactions.
48 . The method of claim 45 , wherein the produced antigen-binding fragments comprise one or more regulatory T cell epitopes which suppress immune reactions.