Isolation and Preliminary Characterization of a Novel scFv against SARS-CoV-2 : an Experimental and Computational Analysis.

Abstract

Background: Since the initial outbreak, the SARS-CoV-2 virus has continued to circulate and mutate, resulting in the emergence of new viral sublineages. Due to the lack of effective protection and therapeutic measures against these new variants, the virus is able to further evolve and diversify. This study aimed to screen a phage antibody library to identify monoclonal antibodies in single-chain variable fragment (scFv) format that target the Receptor Binding Domain (RBD) of different SARS-CoV-2 strains. The newly discovered scFv has the potential for use as a diagnostic or therapeutic option against SARS-CoV-2.

Methods: The RBD protein was produced, purified, and used as an antigen during biopanning. Six rounds of panning enriched RBD-specific phages and the binding affinity of binders were monitored by polyclonal phage ELISA. Subsequently, monoclonal phage ELISA was employed to identify specific binders. After sequence confirmation, the reactivity of the isolated anti-RBD scFv was evaluated. Additionally, bioinformatics tools determined the interaction between selected scFv and SARS-CoV-2 strains.

Results: The ELISA analysis demonstrated that the expressed RBD retains its structural integrity and effectively interacts with antibodies present in the sera of COVID-19 patients. Through screening a phage display library, a strong-binding scFv for RBD was discovered, which can effectively neutralize SARS-CoV-2 and its novel variants.

Conclusion: The findings of this study have led to the discovery of a novel scFv that effectively neutralizes SARS-CoV-2 strains, offering immense potential for research and therapy purposes.