PROCESS FOR PRODUCING HUMANIZED CHIMERA ANTIBODY

摘要

A process for the production of humanized chimera antibody, wherein the chimera antibody is produced easily without changing any of the amino acids of its mouse antibody variable region, which comprises the steps of: (1) constructing a cassette vector by inserting a cDNA coding for a heavy chain constant region of human antibody into an expression vector for animal cell use and establishing a cloning site in the upstream region of the heavy chain constant region of said cassette vector for inserting a cDNA which encodes a heavy chain variable region of nonhuman animal antibody; (2) digesting a cDNA coding for the heavy chain variable region of nonhuman animal antibody with restriction enzymes; (3) inserting said cDNA coding for the heavy chain variable region of nonhuman animal antibody into the cassette vector, using a synthetic DNA which comprises a base sequence corresponding to the 5'-end side of said heavy chain constant region of human antibody and a base sequence corresponding to the 3'-end side of said heavy chain variable region of nonhuman animal antibody and is possessed of the restriction enzyme recognition sites on both of its ends, thereby constructing a humanized chimera antibody heavy chain expression vector in which said cDNA coding for the heavy chain constant region of human antibody and said cDNA coding for the heavy chain variable region of nonhuman animal antibody are linked together through said synthetic DNA; (4) constructing a cassette vector by inserting a cDNA coding for a light chain constant region of human antibody into an expression vector for animal cell use and establishing a cloning site in the upstream region of the light chain constant region of said cassette vector for inserting a cDNA which encodes a light chain variable region of nonhuman animal antibody; (5) digesting a cDNA coding for the light chain variable region of nonhuman animal antibody with restriction enzymes; (6) inserting said cDNA coding for a light chain variable region of nonhuman animal antibody into the cassette vector using a synthetic DNA which comprises a base sequence corresponding to the 5'-end side of said light chain constant region of human antibody and a base sequence corresponding to the 3'-end side of said light chain variable region of nonhuman animal antibody and is possessed of the restriction enzyme recognition sites on both of its ends, thereby constructing a humanized chimera antibody light chain expression vector in which said cDNA coding for the light chain constant region of human antibody and said cDNA coding for the light chain variable region of nonhuman animal antibody are linked together through said synthetic DNA; (7) introducing these expression vectors into host cells to obtain a transformant; and (8) culturing said transformant in an appropriate culture medium, thereby allowing the transformant to produce and accumulate a humanized chimera antibody, and collecting said humanized chimera antibody from the resulting culture broth.