Isolation and Characterization of Neutralizing Monoclonal Antibodies from a Large Panel of Murine Antibodies against RBD of the SARS-CoV-2 Spike Protein

Antibodies (Basel). 2024 Jan 5;13(1):5. doi: 10.3390/antib13010005.

Abstract

The COVID-19 pandemic, once a global crisis, is now largely under control, a testament to the extraordinary global efforts involving vaccination and public health measures. However, the relentless evolution of SARS-CoV-2, leading to the emergence of new variants, continues to underscore the importance of remaining vigilant and adaptable. Monoclonal antibodies (mAbs) have stood out as a powerful and immediate therapeutic response to COVID-19. Despite the success of mAbs, the evolution of SARS-CoV-2 continues to pose challenges and the available antibodies are no longer effective. New variants require the ongoing development of effective antibodies. In the present study, we describe the generation and characterization of neutralizing mAbs against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein by combining plasmid DNA and recombinant protein vaccination. By integrating genetic immunization for rapid antibody production and the potent immune stimulation enabled by protein vaccination, we produced a rich pool of antibodies, each with unique binding and neutralizing specificities, tested with the ELISA, BLI and FACS assays and the pseudovirus assay, respectively. Here, we present a panel of mAbs effective against the SARS-CoV-2 variants up to Omicron BA.1 and BA.5, with the flexibility to target emerging variants. This approach ensures the preparedness principle is in place to address SARS-CoV-2 actual and future infections.

Keywords: SARS-CoV-2; betacoronaviruses; mAb panel; neutralizing antibodies; pancoronavirus; pandemic preparedness.

Grants and funding

J.M. acknowledges funding by the German Research Foundation through CRC 1279. J.M. was further supported by the Ministry of Science, Research and the Arts of Baden-Württemberg as part of the new special funding line COVID-19, which is part of the measures to combat the Coronavirus SARS-CoV-2 pandemic in the field of medical research. A.S. and L.W. are part of the International Graduate School in Molecular Medicine Ulm. Takis is also grateful to Lazio Innova for the funding for the GENERAS project, which is part of the measures to combat the Coronavirus SARS-CoV-2 pandemic in the Lazio Region, Italy.