Reduced Binding between Omicron B.1.1.529 and the Human ACE2 Receptor in a Surrogate Virus Neutralization Test for SARS-CoV-2

Viruses. 2023 May 30;15(6):1280. doi: 10.3390/v15061280.

Abstract

The current gold standard assay for detecting neutralizing antibodies (NAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the conventional virus neutralization test (cVNT), which requires infectious virus and a biosafety level 3 laboratory. Here, we report the development of a SARS-CoV-2 surrogate virus neutralization test (sVNT) that, with Luminex technology, detects NAbs. The assay was designed to mimic the virus-host interaction and is based on antibody blockage between the human angiotensin-converting enzyme 2 (hACE2) receptor and the spike (S) protein of the Wuhan, Delta, and Omicron (B.1.1.529) variants of SARS-CoV-2. The sVNT proved to have a 100% correlation with a SARS-CoV-2 cVNT regarding qualitative results. Binding between the hACE2 receptor and the S1 domain of the B.1.1.529 lineage of the Omicron variant was not observed in the assay but between the receptor and an S1 + S2 trimer and the receptor binding domain (RBD) in a reduced manner, suggesting less efficient receptor binding for the B.1.1.529 Omicron variant. The results indicate that the SARS-CoV-2 sVNT is a suitable tool for both the research community and the public health service, as it may serve as an efficient diagnostic alternative to the cVNT.

Keywords: ACE2; Omicron; SARS-CoV-2; antibody-mediated blockage; receptor binding domain; spike.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin-Converting Enzyme 2*
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19* / diagnosis
  • Humans
  • Neutralization Tests
  • SARS-CoV-2 / genetics
  • Spike Glycoprotein, Coronavirus / genetics

Substances

  • Angiotensin-Converting Enzyme 2
  • Antibodies, Neutralizing
  • Spike Glycoprotein, Coronavirus
  • Antibodies, Viral
  • spike protein, SARS-CoV-2

Supplementary concepts

  • SARS-CoV-2 variants

Grants and funding

This research was funded by the Swedish Research Council (VR: 2018-02569), the European Union’s Horizon 2020 research innovation program (Grant no. 874735 (VEO)), and the SciLifeLab Pandemic Preparedness projects (LPP1-007 and REPLP1:005).