Construction and selection of a library of scFv monoclonal antibodies against SARS-CoV-2 spike protein by phage display technology

Abstract

Antibodies against SARS-CoV-2 are critical molecules of the efforts to understand and fight the COVID-19 Pandemic. They play a central role in clearing the virus from infected patients. They are key reagents of rapid diagnostics. They are first-line treatments for hospitalized COVID-19 patients and are the main objective of COVID-19 vaccine development. The vaccines and therapeutic antibodies currently available were developed from the spike protein of SARS-CoV-2 variants circulated during the early stages of the Pandemic in 2020. With the emergence of new variants from mutations in the spike protein receptor (RBD) binding site, concerns have been raised about the impairment of neutralizing antibody responses and vaccination programs' effectiveness. In this context, this proposal's objective is the generation of monoclonal antibodies against the Brazilian variant P.1 spike protein for immunotherapy and prevention of COVID-19. So far, there are no antibodies against this new variant, and the development of a national input to combat the Pandemic is significant. The antibodies will be selected from a library of antibody fragments in the scFv format and selected against the spike protein using Phage display technology. After selection, the most reactive antibodies will be produced in the scFv-Fc form in HEK-293 mammalian cells using technology and knowledge acquired during a post-doctoral internship carried out by the applicant in Germany - Stuttgart University. Subsequently, these antibodies' functional characterization will be carried out, for example, the analysis of the antibodies' neutralizing potential to the virus and in silico analyzes to characterize the antigen-antibody interaction. This study will provide a database of neutralizing antibodies for SARS-CoV-2 that can contribute to the development of effective immunotherapies in the clinical management of patients with COVID-19 in the future. This proposal is part of the Institutional Research Development Plan of the Instituto Adolfo Lutz (PDIP) (Process: 17/50333-7). (AU)