title: Single variable domain antibody as a versatile building block for the construction of IgG-like bispecific antibodies.
abstract: Bispecific antibodies (BsAb) have been traditionally utilized to redirect cytotoxic effector cells and agents to kill tumor cells expressing the target antigens. Recently a new concept is emerging to develop BsAb that simultaneously block the functions of two tumor-associated targets, eg., growth factor receptors, for enhanced antitumor efficacies. Broad clinical applications of BsAb have been, and still are, significantly hampered by the difficulty in producing the materials in sufficient quantity and quality by traditional approaches. Here we describe a recombinant approach for the production of an Fc domain-containing, IgG-like tetravalent BsAb, using a single variable domain (sVD) antibody as a versatile building block. In this method, a sVD of a defined specificity is genetically fused to either the N-terminus of the light chain or the C-terminus of the heavy chain of a functional IgG antibody of a different specificity. A model BsAb was constructed using a sVD to mouse platelet derived growth factor receptor alpha and a conventional IgG antibody to mouse platelet derived growth factor receptor beta. The BsAb were expressed in mammalian cells and purified to homogeneity by a one-step Protein A affinity chromatography. Further, the BsAb retained the antigen binding specificity and the receptor neutralizing activity of both of its parent antibodies. Importantly, the BsAb inhibited the activation of both its target receptors in tumor cells stimulated by both platelet derived growth factor AA and BB, whereas the parent monospecific antibody only inhibited the activation of a single receptor stimulated by its cognate ligand. This format of BsAb should be readily applicable to the production of other BsAb recognizing any pairs of antigens.
authors.affiliation: Department of Antibody Technology, Department of Cell Engineering and Expression, ImClone Systems Incorporation, 180 Varick Street, New York, NY 10014, USA. juqun.shen@imclone.com
authors.forename: Juqun
authors.initials: J
authors.lastname: Shen
authors.forename: Marie Danielle
authors.initials: MD
authors.lastname: Vil
authors.forename: Xenia
authors.initials: X
authors.lastname: Jimenez
authors.forename: Haifan
authors.initials: H
authors.lastname: Zhang
authors.forename: Michelle
authors.initials: M
authors.lastname: Iacolina
authors.forename: Venkat
authors.initials: V
authors.lastname: Mangalampalli
authors.forename: Paul
authors.initials: P
authors.lastname: Balderes
authors.forename: Dale L
authors.initials: DL
authors.lastname: Ludwig
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000818:Animals; D018033:Antibodies, Bispecific / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D000915:Antibody Affinity / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D000077214:Becaplermin; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D004591:Electrophoresis, Polyacrylamide Gel; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics* / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000235:genetics / Q000276:immunology; D007700:Kinetics; D051379:Mice; D008958:Models, Molecular; D010766:Phosphorylation / Q000187:drug effects; D010982:Platelet-Derived Growth Factor / Q000737:chemistry / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D014162:Transfection
chemical_list: D018033:Antibodies, Bispecific; D007074:Immunoglobulin G; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D011993:Recombinant Fusion Proteins; C075278:platelet-derived growth factor A; D000077214:Becaplermin; D020796:Receptor, Platelet-Derived Growth Factor alpha; D020797:Receptor, Platelet-Derived Growth Factor beta