SARS-CoV-2 Reverse Genetics Reveals a Variable Infection Gradient in the Respiratory Tract

Cell. 2020 Jul 23;182(2):429-446.e14. doi: 10.1016/j.cell.2020.05.042. Epub 2020 May 27.

Abstract

The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.

Keywords: ACE2; COVID-19; SARS-CoV-2; infectious clone; nasal infection; neutralization assay; primary cells; reporter virus; respiratory tropism; reverse genetics.

Publication types

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

MeSH terms

  • Aged
  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Neutralizing / immunology
  • Betacoronavirus / genetics*
  • Betacoronavirus / immunology
  • Betacoronavirus / pathogenicity
  • Cell Line
  • Cells, Cultured
  • Chlorocebus aethiops
  • Coronavirus Infections / immunology
  • Coronavirus Infections / pathology*
  • Coronavirus Infections / therapy
  • Coronavirus Infections / virology*
  • Cystic Fibrosis / pathology
  • DNA, Recombinant
  • Female
  • Furin / metabolism
  • Humans
  • Immunization, Passive
  • Lung / metabolism
  • Lung / pathology
  • Lung / virology
  • Male
  • Middle Aged
  • Nasal Mucosa / metabolism
  • Nasal Mucosa / pathology
  • Nasal Mucosa / virology
  • Pandemics
  • Peptidyl-Dipeptidase A / metabolism
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / pathology*
  • Pneumonia, Viral / virology*
  • Respiratory System / pathology
  • Respiratory System / virology*
  • Reverse Genetics / methods*
  • Serine Endopeptidases / metabolism
  • Vero Cells
  • Virulence
  • Virus Replication

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • DNA, Recombinant
  • Peptidyl-Dipeptidase A
  • angiotensin converting enzyme 2
  • Serine Endopeptidases
  • TMPRSS2 protein, human
  • Furin

Supplementary concepts

  • COVID-19
  • COVID-19 serotherapy
  • severe acute respiratory syndrome coronavirus 2