title: Synergistic Neutralization of Pertussis Toxin by a Bispecific Antibody In Vitro and In Vivo.
abstract: Bispecific antibodies are a rapidly growing class of therapeutic molecules, originally developed for the treatment of cancer but recently explored for the treatment of autoimmune and infectious diseases. Bordetella pertussis is a reemerging pathogen, and several of the key symptoms of infection are caused by the pertussis toxin (PTx). Two humanized antibodies, hu1B7 and hu11E6, bind distinct epitopes on PTx and, when coadministered, mitigate disease severity in murine and baboon models of infection. Here we describe the generation of a bispecific human IgG1 molecule combining the hu1B7 and hu11E6 binding sites via a knobs-in-holes design. The bispecific antibody showed binding activity equivalent to that of the antibody mixture in a competition enzyme-linked immunosorbent assay (ELISA). A CHO cell neutralization assay provided preliminary evidence for synergy between the two antibodies, while a murine model of PTx-induced leukocytosis definitively showed synergistic neutralization. Notably, the bispecific antibody retained the synergy observed for the antibody mixture, supporting the conclusion that synergy is due to simultaneous blockade of both the catalytic and receptor binding activities of pertussis toxin. These data suggest that a hu1B7/hu11E6 bispecific antibody is a viable alternative to an antibody mixture for pertussis treatment.
authors: McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA.
authors: Ellen K
authors: EK
authors: Wagner
authors: Department of Biochemistry, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA.
authors: Xianzhe
authors: X
authors: Wang
authors: Proteomics Facility, The University of Texas at Austin, Austin, Texas, USA.
authors: Andre
authors: A
authors: Bui
authors: McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA maynard@che.utexas.edu.|Department of Biochemistry, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA.
authors: Jennifer A
authors: http://orcid.org/0000-0002-0363-8486
authors: JA
authors: Maynard
mesh_terms: D000818:Animals; D018033:Antibodies, Bispecific / Q000276:immunology* / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000276:immunology; D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism / Q000627:therapeutic use; D001666:Binding Sites, Antibody; D001886:Bordetella pertussis / Q000276:immunology; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004357:Drug Synergism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D009500:Neutralization Tests; D037342:Pertussis Toxin / Q000276:immunology*; D014917:Whooping Cough / Q000276:immunology / Q000517:prevention & control / Q000628:therapy*
chemical_list: D018033:Antibodies, Bispecific; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000939:Epitopes; D007074:Immunoglobulin G; D037342:Pertussis Toxin