Antibody-based interventions against SARS-CoV-2 could limit morbidity, mortality, and possibly transmission. An anticipated correlate of such countermeasures is the level of neutralizing antibodies against the SARS-CoV-2 spike protein, which engages with host ACE2 receptor for entry. Using an infectious molecular clone of vesicular stomatitis virus (VSV) expressing eGFP as a marker of infection, we replaced the glycoprotein gene (G) with the spike protein of SARS-CoV-2 (VSV-eGFP-SARS-CoV-2) and developed a high-throughput-imaging-based neutralization assay at biosafety level 2. We also developed a focus-reduction neutralization test with a clinical isolate of SARS-CoV-2 at biosafety level 3. Comparing the neutralizing activities of various antibodies and ACE2-Fc soluble decoy protein in both assays revealed a high degree of concordance. These assays will help define correlates of protection for antibody-based countermeasures and vaccines against SARS-CoV-2. Additionally, replication-competent VSV-eGFP-SARS-CoV-2 provides a tool for testing inhibitors of SARS-CoV-2 mediated entry under reduced biosafety containment. Graphical Abstract Highlights • Vesicular stomatitis virus encoding the SARS-CoV-2 spike replicates to high titers • Virus propagation is enhanced by a truncation in the cytoplasmic tail of the spike • Neutralization can be assessed by BSL2 and BSL3 high-throughput assays • SARS-CoV-2- and VSV-SARS-CoV-2-based neutralization assays correlate Case, Rothlauf et al. generate a replication-competent vesicular stomatitis virus (VSV) expressing the SARS-CoV-2 spike and compare the neutralizing activity of antibodies with VSV-SARS-CoV-2 to fully infectious SARS-CoV-2. They show that VSV-SARS-CoV-2 is a useful BSL2 surrogate virus, as neutralization profiles strongly correlate with focus-reduction neutralization tests using SARS-CoV-2.
【저자키워드】 SARS-CoV-2, ACE2, coronavirus, COVID19, antibody, serum, VSV, Neutralizing, surrogate assay,