title: Development of tetravalent, bispecific CCR5 antibodies with antiviral activity against CCR5 monoclonal antibody-resistant HIV-1 strains.
abstract: In this study, we describe novel tetravalent, bispecific antibody derivatives that bind two different epitopes on the HIV coreceptor CCR5. The basic protein formats that we applied were derived from Morrison-type bispecific antibodies: whole IgGs to which we connected single-chain antibodies (scFvs) via (Gly4Ser)n sequences at either the C or N terminus of the light chain or heavy chain. By design optimization, including disulfide stabilization of scFvs or introduction of 30-amino-acid linkers, stable molecules could be obtained in amounts that were within the same range as or no less than 4-fold lower than those observed with monoclonal antibodies in transient expression assays. In contrast to monospecific CCR5 antibodies, bispecific antibody derivatives block two alternative docking sites of CCR5-tropic HIV strains on the CCR5 coreceptor. Consequently, these molecules showed 18- to 57-fold increased antiviral activities compared to the parent antibodies. Most importantly, one prototypic tetravalent CCR5 antibody had antiviral activity against virus strains resistant to the single parental antibodies. In summary, physical linkage of two CCR5 antibodies targeting different epitopes on the HIV coreceptor CCR5 resulted in tetravalent, bispecific antibodies with enhanced antiviral potency against wild-type and CCR5 antibody-resistant HIV-1 strains.
authors.affiliation: Roche Diagnostics GmbH, Nonnenwald 2, D-82372 Penzberg, Germany. juergen_michael.schanzer@roche.com
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schanzer
authors.forename: Andreas
authors.initials: A
authors.lastname: Jekle
authors.forename: Junichi
authors.initials: J
authors.lastname: Nezu
authors.forename: Adriane
authors.initials: A
authors.lastname: Lochner
authors.forename: Rebecca
authors.initials: R
authors.lastname: Croasdale
authors.forename: Marianna
authors.initials: M
authors.lastname: Dioszegi
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Eike
authors.initials: E
authors.lastname: Hoffmann
authors.forename: Wilma
authors.initials: W
authors.lastname: Dormeyer
authors.forename: Jan
authors.initials: J
authors.lastname: Stracke
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schäfer
authors.forename: Changhua
authors.initials: C
authors.lastname: Ji
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Heilek
authors.forename: Nick
authors.initials: N
authors.lastname: Cammack
authors.forename: Michael
authors.initials: M
authors.lastname: Brandt
authors.forename: Pablo
authors.initials: P
authors.lastname: Umana
authors.forename: Ulrich
authors.initials: U
authors.lastname: Brinkmann
mesh_terms: D018033:Antibodies, Bispecific / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D015497:HIV-1 / Q000187:drug effects* / Q000276:immunology; D006801:Humans; D019713:Receptors, CCR5 / Q000276:immunology*
chemical_list: D018033:Antibodies, Bispecific; D019713:Receptors, CCR5