Neutralizing Antibody and Soluble ACE2 Inhibition of a Replication-Competent VSV-SARS-CoV-2 and a Clinical Isolate of SARS-CoV-2

Cell Host Microbe. 2020 Sep 9;28(3):475-485.e5. doi: 10.1016/j.chom.2020.06.021. Epub 2020 Jul 3.

Abstract

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.

Keywords: ACE2; COVID19; SARS-CoV-2; VSV; antibody; coronavirus; neutralizing; serum; surrogate assay.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin-Converting Enzyme 2
  • Animals
  • Antibodies, Neutralizing / blood*
  • Antibodies, Viral / blood*
  • Betacoronavirus / genetics
  • Betacoronavirus / immunology*
  • Betacoronavirus / physiology
  • COVID-19
  • Chlorocebus aethiops
  • Coronavirus Infections / genetics
  • Coronavirus Infections / immunology
  • Coronavirus Infections / therapy*
  • Coronavirus Infections / virology
  • Green Fluorescent Proteins / genetics
  • Host Microbial Interactions / immunology
  • Humans
  • Immunization, Passive
  • Neutralization Tests
  • Pandemics
  • Peptidyl-Dipeptidase A / immunology*
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / therapy*
  • Pneumonia, Viral / virology
  • SARS-CoV-2
  • Spike Glycoprotein, Coronavirus / genetics
  • Spike Glycoprotein, Coronavirus / immunology
  • Vero Cells
  • Vesicular stomatitis Indiana virus / genetics
  • Vesicular stomatitis Indiana virus / immunology
  • Virus Internalization
  • Virus Replication

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Spike Glycoprotein, Coronavirus
  • enhanced green fluorescent protein
  • spike protein, SARS-CoV-2
  • Green Fluorescent Proteins
  • Peptidyl-Dipeptidase A
  • ACE2 protein, human
  • Angiotensin-Converting Enzyme 2

Supplementary concepts

  • COVID-19 serotherapy