HUMANIZED IMMUNOGLOBULIN REACTING WITH α4β7 INTEGRIN

PROBLEM TO BE SOLVED: To provide an improved therapeutic approach for inflammatory bowel diseases. SOLUTION: This isolated nucleic acid is provided by comprising a nucleotide sequence encoding a humanized immunoglobulin light chain or its antigen-binding fragments. The humanized immunoglobulin light chain or its antigen-binding fragments comprises the complementarity-deciding regions (CDR1, CDR2 and CDR3) of light chains of a murine Act-1 monoclonal antibody, and the complementarity-deciding regions comprise amino acid sequences shown by the light chains:CDR1, amino acids 44 to 59 of sequence number:12, CDR2, amino acids 75 to 81 of the sequence number:12, and CDR3, amino acids 114 to 122 of the sequence number:12. A light chain-framing region is derived from the light chain (sequence number:8) of GM607'CL antibody, isoleucine at the second position of the Kabat is exchanged with valine, and as a result, the light chain or an antibody comprising its antigen-binding fragments selectively binds with the α4β7 integrin. COPYRIGHT: (C)2011,JPO&INPIT