This invention relates to a gene recombination antibodies composition with higer complement-dependent cell cytotoxicity than human IgG1 antibody and human IgG3 antibody, the polypeptide of CH2 domain of Fc region in human IgG1 antibody is substituted by the polypeptide corresponding to the same site of amino acid sequence of human IgG3 antibody of EU Index from Kabat et.al. a DNA, which encodes the said antibody molecular or the heavy chain constant region of the said antibody molecular contained in the said gene recombination antibodies compositon a transform, obtained from introducing the said DNA into a host cell a production method of gene recombination antibodies compositon by using the said transform and a medicine, which comprises the said gene recombination antibodies composition as the effective ingredient.本發明係關於顯示較人類IgG1抗體及人類IgG3抗體更高補體依存性細胞傷害活性之基因重組抗體組成物,係將人類IgG1抗體所含Fc區中之CH2功能域(domain)之多胜肽,置換為相當於由Kabat等人於EUIndex之人類IgG3抗體之相同位置的胺基酸序列組成的多胜肽;係關於編碼該基因重組抗體組成物所含抗體分子或該抗體分子之重鏈恆定區的DNA;關於將該DNA導入宿主細胞所得之轉形體;關於使用該轉形體的基因重組抗體組成物之生產方法;及關於含有該基因重組抗體組成物為有效成分之醫藥。
