Despite unprecedented global efforts to rapidly develop SARS-CoV-2 treatments, in order to reduce the burden placed on health systems, the situation remains critical. Effective diagnosis, treatment, and prophylactic measures are urgently required to meet global demand: recombinant antibodies fulfill these requirements and have marked clinical potential. Here, we describe the fast-tracked development of an alpaca Nanobody specific for the receptor-binding-domain (RBD) of the SARS-CoV-2 Spike protein with potential therapeutic applicability. We present a rapid method for nanobody isolation that includes an optimized immunization regimen coupled with VHH library E. coli surface display, which allows single-step selection of Nanobodies using a simple density gradient centrifugation of the bacterial library. The selected single and monomeric Nanobody, W25, binds to the SARS-CoV-2 S RBD with sub-nanomolar affinity and efficiently competes with ACE-2 receptor binding. Furthermore, W25 potently neutralizes SARS-CoV-2 wild type and the D614G variant with IC50 values in the nanomolar range, demonstrating its potential as antiviral agent.
【저자키워드】 immunology, Biochemistry, Molecular biology, Biotechnology, Cell Biology, 【초록키워드】 Treatment, SARS-CoV-2, Antiviral, spike, antibody, Diagnosis, health systems, immunization, IC50, Spike protein, ACE-2 receptor, Protein, nanobody, RBD, D614G variant, SARS-CoV-2 spike protein, therapeutic, nanobodies, Isolation, antiviral agent, alpaca, Critical, wild type, binding, Bacterial, regimen, prophylactic measures, density gradient centrifugation, prophylactic measure, E. coli, density gradient, situation, S RBD, applicability, centrifugation, neutralize, bind, selected, develop, include, required, reduce, global effort, monomeric, the SARS-CoV-2, 【제목키워드】 SARS-CoV-2, neutralization, potent, G614 variant, isolate, monomeric,