title: A new format of bispecific antibody: highly efficient heterodimerization, expression and tumor cell lysis.
abstract: Bispecific antibodies (BsAbs) have been considered as potential therapeutics for cancer. A major obstacle in the development of BsAb has been the difficulty in producing a heterodimer with two different arms and in sufficient quantity for clinical application by the traditional methods. We describe a new format of BsAb that consists of two single-chain variable fragment of antibodies (scFvs), one for human epidermal growth factor receptor 2 (HER2)/neu and the other for CD16, heterodimerized by a "knobs-into-holes" device from the CH3 domains of the human IgG1 Fc fragment. The two chains were functionally expressed in CHO cells and assembled into heterodimers with dual antigen-binding specificity. Compared with other types of engineered BsAbs expressed in mammalian cells, the yield of this BsAb was relatively high (12-14 mg/l). In vitro experiments demonstrated that the BsAb was able to recruit human peripheral blood mononuclear cells (PBMC) to kill SK-BR-3 cells more effectively than the commercial anti-HER2/neu antibody Herceptin (Roche, Shanghai). This new format of BsAb possesses properties that support its potential as a new antitumor agent.
authors.affiliation: Department of Molecular Immunology, Beijing Institute of Basic Medical Sciences, Taiping Road 27, Beijing 100850, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Xie
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
authors.forename: Ming
authors.initials: M
authors.lastname: Yu
authors.forename: Meiru
authors.initials: M
authors.lastname: Hu
authors.forename: Beifen
authors.initials: B
authors.lastname: Shen
mesh_terms: D000818:Animals; D018033:Antibodies, Bispecific / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D000912:Antibodies, Neoplasm / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D001943:Breast Neoplasms / Q000276:immunology; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D019281:Dimerization; D058851:GPI-Linked Proteins; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology*; D014162:Transfection
chemical_list: D018033:Antibodies, Bispecific; D000912:Antibodies, Neoplasm; D015703:Antigens, CD; D000970:Antineoplastic Agents; D058851:GPI-Linked Proteins; D007141:Immunoglobulin Fc Fragments; D007135:Immunoglobulin Variable Region; D018719:Erb-b2 Receptor Tyrosine Kinases; D017452:Receptors, IgG; C428200:FCGR3B protein, human