In:
European Respiratory Journal, European Respiratory Society (ERS), Vol. 60, No. 6 ( 2022-12), p. 2102725-
Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) utilises the angiotensin-converting enzyme 2 (ACE2) transmembrane peptidase as cellular entry receptor. However, whether SARS-CoV-2 in the alveolar compartment is strictly ACE2-dependent and to what extent virus-induced tissue damage and/or direct immune activation determines early pathogenesis is still elusive. Methods Spectral microscopy, single-cell/-nucleus RNA sequencing or ACE2 “gain-of-function” experiments were applied to infected human lung explants and adult stem cell derived human lung organoids to correlate ACE2 and related host factors with SARS-CoV-2 tropism, propagation, virulence and immune activation compared to SARS-CoV, influenza and Middle East respiratory syndrome coronavirus (MERS-CoV). Coronavirus disease 2019 (COVID-19) autopsy material was used to validate ex vivo results. Results We provide evidence that alveolar ACE2 expression must be considered scarce, thereby limiting SARS-CoV-2 propagation and virus-induced tissue damage in the human alveolus. Instead, ex vivo infected human lungs and COVID-19 autopsy samples showed that alveolar macrophages were frequently positive for SARS-CoV-2. Single-cell/-nucleus transcriptomics further revealed nonproductive virus uptake and a related inflammatory and anti-viral activation, especially in “inflammatory alveolar macrophages”, comparable to those induced by SARS-CoV and MERS-CoV, but different from NL63 or influenza virus infection. Conclusions Collectively, our findings indicate that severe lung injury in COVID-19 probably results from a macrophage-triggered immune activation rather than direct viral damage of the alveolar compartment.
Type of Medium:
Online Resource
ISSN:
0903-1936
,
1399-3003
DOI:
10.1183/13993003.02725-2021
DOI:
10.1183/13993003.02725-2021.Supp1
DOI:
10.1183/13993003.02725-2021.Shareable1
Language:
English
Publisher:
European Respiratory Society (ERS)
Publication Date:
2022
detail.hit.zdb_id:
639359-7
detail.hit.zdb_id:
1499101-9
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