An engineered decoy receptor for SARS-CoV-2 broadly binds protein S sequence variants

Sci Adv. 2021 Feb 17;7(8):eabf1738. doi: 10.1126/sciadv.abf1738. Print 2021 Feb.

Abstract

The spike S of SARS-CoV-2 recognizes ACE2 on the host cell membrane to initiate entry. Soluble decoy receptors, in which the ACE2 ectodomain is engineered to block S with high affinity, potently neutralize infection and, because of close similarity with the natural receptor, hold out the promise of being broadly active against virus variants without opportunity for escape. Here, we directly test this hypothesis. We find that an engineered decoy receptor, sACE22v2.4, tightly binds S of SARS-associated viruses from humans and bats, despite the ACE2-binding surface being a region of high diversity. Saturation mutagenesis of the receptor-binding domain followed by in vitro selection, with wild-type ACE2 and the engineered decoy competing for binding sites, failed to find S mutants that discriminate in favor of the wild-type receptor. We conclude that resistance to engineered decoys will be rare and that decoys may be active against future outbreaks of SARS-associated betacoronaviruses.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Angiotensin-Converting Enzyme 2 / chemistry*
  • Angiotensin-Converting Enzyme 2 / genetics
  • Angiotensin-Converting Enzyme 2 / metabolism
  • Angiotensin-Converting Enzyme 2 / therapeutic use
  • Animals
  • COVID-19 Drug Treatment*
  • Cell Line
  • Chiroptera
  • Humans
  • Mutagenesis
  • Protein Domains
  • Protein Engineering*
  • SARS-CoV-2 / chemistry*
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / metabolism

Substances

  • ACE2 protein, human
  • Angiotensin-Converting Enzyme 2