title: Novel bifunctional single-chain variable antibody fragments to enhance virolysis by complement: generation and proof-of-concept.
abstract: When bound to the envelope of viruses, factor H (FH), a soluble regulator of complement activation, contributes to the protection against a potent immune defense mechanism, the complement-mediated lysis (CML). Thus, removing FH from the surface renders viruses, such as HIV, susceptible to CML. For a proof of concept, we developed a construct consisting of recombinant bifunctional single-chain variable fragment (scFv) based on a monoclonal antibody against Friend murine leukemia virus (F-MuLV) envelope protein gp70, which was coupled to specific binding domains (short consensus repeats 19-20; SCR1920) of FH. We used Pichia pastoris as expression system in common shake flasks and optimized expression in high density bench top fermentation. Specific binding of recombinant scFv was proven by flow cytometry. The recombinant scFv-SCR significantly enhanced CML of F-MuLV in vitro implying that FH binding to the viral surface was impaired by the scFv-SCR. This novel concept to enhance virolysis may provide a new approach for antiviral treatment.
authors: Division of Virology, Innsbruck Medical University, Peter-Mayr-Straße 4b, 6020 Innsbruck, Austria.
authors: Georg
authors: 0000-0001-9680-2785
authors: G
authors: Huber
authors: Division of Virology, Innsbruck Medical University, Peter-Mayr-Straße 4b, 6020 Innsbruck, Austria.
authors: Zoltán
authors: Z
authors: Bánki
authors: Department of Biotechnology, VIBT, BOKU-University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria.
authors: Renate
authors: R
authors: Kunert
authors: Division of Virology, Innsbruck Medical University, Peter-Mayr-Straße 4b, 6020 Innsbruck, Austria.
authors: Heribert
authors: 0000-0002-4266-8397
authors: H
authors: Stoiber
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018033:Antibodies, Bispecific / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D017242:Complement Factor H / Q000276:immunology / Q000378:metabolism; D005285:Fermentation; D005622:Friend murine leukemia virus / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010843:Pichia; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D057127:Single-Chain Antibodies / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000276:immunology / Q000378:metabolism*
chemical_list: D018033:Antibodies, Bispecific; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; D014759:Viral Envelope Proteins; D017242:Complement Factor H