title: Preparation of human IgG and IgM monoclonal antibodies for MK-1/Ep-CAM by using human immunoglobulin gene-transferred mouse and gene cloning of their variable regions.
abstract: For antibody-based therapy of cancer, monoclonal antibodies (mAbs) of human origin are superior to mouse, mouse/human chimeric or humanized mAbs, because of their minimum immunogenicity to humans and their efficient collaboration with human effector cells. In the present study, human mAbs were prepared against a pancarcinoma antigen, MK-1 (Ep-CAM), using a genetically-engineered mouse (KM mouse) that contains the human immunoglobulin genes. Spleen cells from KM mice, immunized with recombinant MK-1, were fused with P3-U1 mouse myeloma cells. Of 44 anti-MK-1 clones analyzed, two were of IgG4 and the others of IgM clones. Although the two IgG4 clones were suggested to recognize the same antigenic determinant or two closely located determinants, their VK regions were encoded by different light-chain genes while their VH sequences were identical. The two IgG4 and one of the IgM clones tested revealed antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity, respectively, against MK-1-expressing cells in vitro, suggesting that these fully human mAbs produced against MK-1 and their V-region genes, which are applicable for the preparation of engineered antibody fragments that may be useful for antibody-based therapy of cancer.
authors.affiliation: Department of Biochemistry, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan. mokuroki@fukuoka-u.ac.jp
authors.forename: Motomu
authors.initials: M
authors.lastname: Kuroki
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yamada
authors.forename: Hirotomo
authors.initials: H
authors.lastname: Shibaguchi
authors.forename: Ken
authors.initials: K
authors.lastname: Hachimine
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Hirose
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Kinugasa
authors.forename: Isao
authors.initials: I
authors.lastname: Ishida
authors.forename: Masahide
authors.initials: M
authors.lastname: Kuroki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology* / Q000494:pharmacology; D000920:Antibody-Dependent Cell Cytotoxicity; D000951:Antigens, Neoplasm / Q000276:immunology*; D016466:CHO Cells; D015815:Cell Adhesion Molecules / Q000276:immunology*; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D006224:Cricetinae; D000071858:Epithelial Cell Adhesion Molecule; D018014:Gene Transfer Techniques; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology*; D007075:Immunoglobulin M / Q000235:genetics / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D013274:Stomach Neoplasms / Q000276:immunology / Q000628:therapy
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D011993:Recombinant Fusion Proteins