A Newly Engineered A549 Cell Line Expressing ACE2 and TMPRSS2 Is Highly Permissive to SARS-CoV-2, Including the Delta and Omicron Variants

Viruses. 2022 Jun 23;14(7):1369. doi: 10.3390/v14071369.

Abstract

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, causing surges, breakthrough infections, and devastating losses-underscoring the importance of identifying SARS-CoV-2 antivirals. A simple, accessible human cell culture model permissive to SARS-CoV-2 variants is critical for identifying and assessing antivirals in a high-throughput manner. Although human alveolar A549 cells are a valuable model for studying respiratory virus infections, they lack two essential host factors for SARS-CoV-2 infection: angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). SARS-CoV-2 uses the ACE2 receptor for viral entry and TMPRSS2 to prime the SARS-CoV-2 spike protein, both of which are negligibly expressed in A549 cells. Here, we report the generation of a suitable human cell line for SARS-CoV-2 studies by transducing human ACE2 and TMPRSS2 into A549 cells. We show that subclones highly expressing ACE2 and TMPRSS2 ("ACE2plus" and the subclone "ACE2plusC3") are susceptible to infection with SARS-CoV-2, including the delta and omicron variants. These subclones express more ACE2 and TMPRSS2 transcripts than existing commercial A549 cells engineered to express ACE2 and TMPRSS2. Additionally, the antiviral drugs EIDD-1931, remdesivir, nirmatrelvir, and nelfinavir strongly inhibit SARS-CoV-2 variants in our infection model. Our data show that ACE2plusC3 cells are highly permissive to SARS-CoV-2 infection and can be used to identify anti-SARS-CoV-2 drugs.

Keywords: A549; ACE2; EIDD-1931; SARS-CoV-2; TMPRSS2; delta and omicron variants; nirmatrelvir; remdesivir.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • A549 Cells
  • Angiotensin-Converting Enzyme 2* / genetics
  • Antiviral Agents / pharmacology
  • COVID-19*
  • Humans
  • Peptidyl-Dipeptidase A / metabolism
  • SARS-CoV-2 / genetics
  • Serine Endopeptidases / genetics
  • Spike Glycoprotein, Coronavirus / genetics
  • Spike Glycoprotein, Coronavirus / metabolism

Substances

  • Antiviral Agents
  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2
  • Peptidyl-Dipeptidase A
  • Angiotensin-Converting Enzyme 2
  • Serine Endopeptidases
  • TMPRSS2 protein, human

Supplementary concepts

  • SARS-CoV-2 variants

Grants and funding

This work was supported by the Department of Defense Award (W81XWH2110029) “COVID-19 Expansion for AIRe” to R.W.F. and a Ferring COVID-19 Investigational Grant to C.-W.C.