title: An efficient route to the production of an IgG-like bispecific antibody.
abstract: Production of IgG-form bispecific antibody (BsAb-IgG) by co-expressing two antibodies in transfected cells is often inefficient owing to the unwanted pairing between the component heavy and light chains. We have developed an efficient method for the production of a novel IgG-like BsAb by using the natural dimerization mechanism between IgG heavy and light chains. Two single-chain Fv (scFv) of different specificity are fused to the constant domain of human kappa chain (C(L)) and the first constant domain of human heavy chain (C(H1)), to form two polypeptides, (scFv)(1)-C(L) and (scFv)(2)-C(H1)-C(H2)-C(H3), respectively. Co-expression of the two polypeptides in mammalian cells results in the formation of a covalently linked IgG-like hetero-tetramer, Bs(scFv)(4)-IgG, with dual specificity. Our approach yields a homogeneous bispecific IgG-like antibody product with each molecule containing four antigen binding sites, two for each of its target antigens. A Bs(scFv)(4)-IgG was prepared using two scFv antibodies each directed against a different epitope of a vascular endothelial growth factor receptor, the kinase insert domain-containing receptor (KDR). The Bs(scFv)(4)-IgG is capable of simultaneously binding to the two epitopes on the receptor. Further, the Bs(scFv)(4)-IgG also retains the antigen-binding efficacy and biological activity of its component antibodies.
authors.affiliation: Department of Molecular and Cell Biology, ImClone Systems Incorporated, 180 Varick Street, New York, NY 10014, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Zuo
authors.forename: X
authors.initials: X
authors.lastname: Jimenez
authors.forename: L
authors.initials: L
authors.lastname: Witte
authors.forename: Z
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D018033:Antibodies, Bispecific / Q000096:biosynthesis* / Q000276:immunology; D000918:Antibody Specificity; D005822:Genetic Vectors; D006801:Humans; D007128:Immunoglobulin Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000276:immunology; D008969:Molecular Sequence Data
chemical_list: D018033:Antibodies, Bispecific; D007128:Immunoglobulin Fragments; D007074:Immunoglobulin G