Expression Pattern of the SARS-CoV-2 Entry Genes ACE2 and TMPRSS2 in the Respiratory Tract

Viruses. 2020 Oct 16;12(10):1174. doi: 10.3390/v12101174.


To address the expression pattern of the SARS-CoV-2 receptor ACE2 and the viral priming protease TMPRSS2 in the respiratory tract, this study investigated RNA sequencing transcriptome profiling of samples of airway and oral mucosa. As shown, ACE2 has medium levels of expression in both small airway epithelium and masticatory mucosa, and high levels of expression in nasal epithelium. The expression of ACE2 is low in mucosal-associated invariant T (MAIT) cells and cannot be detected in alveolar macrophages. TMPRSS2 is highly expressed in small airway epithelium and nasal epithelium and has lower expression in masticatory mucosa. Our results provide the molecular basis that the nasal mucosa is the most susceptible locus in the respiratory tract for SARS-CoV-2 infection and consequently for subsequent droplet transmission and should be the focus for protection against SARS-CoV-2 infection.

Keywords: ACE2; COVID-19; SARS-CoV-2; TMPRSS2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin-Converting Enzyme 2
  • Betacoronavirus / physiology*
  • COVID-19
  • Coronavirus Infections / genetics*
  • Coronavirus Infections / metabolism
  • Coronavirus Infections / virology
  • Epithelium / metabolism
  • Epithelium / virology
  • Gene Expression
  • Gene Expression Profiling
  • Humans
  • Nasal Mucosa / metabolism
  • Nasal Mucosa / virology
  • Pandemics
  • Peptidyl-Dipeptidase A / biosynthesis*
  • Peptidyl-Dipeptidase A / genetics
  • Pneumonia, Viral / genetics*
  • Pneumonia, Viral / metabolism
  • Pneumonia, Viral / virology
  • Respiratory System / metabolism
  • Respiratory System / virology
  • SARS-CoV-2
  • Serine Endopeptidases / biosynthesis*
  • Serine Endopeptidases / genetics
  • Virus Internalization*


  • Peptidyl-Dipeptidase A
  • ACE2 protein, human
  • Angiotensin-Converting Enzyme 2
  • Serine Endopeptidases
  • TMPRSS2 protein, human