@article {Evangelou2102951, author = {Konstantinos Evangelou and Dimitris Veroutis and Koralia Paschalaki and Periklis G. Foukas and Nefeli Lagopati and Marios Dimitriou and Angelos Papaspyropoulos and Bindu Konda and Orsalia Hazapis and Aikaterini Polyzou and Sophia Havaki and Athanassios Kotsinas and Christos Kittas and Athanasios G. Tzioufas and Laurence de Leval and Demetris Vassilakos and Sotirios Tsiodras and Barry R. Stripp and Argyris Papantonis and Giovanni Blandino and Ioannis Karakasiliotis and Peter J Barnes and Vassilis G. Gorgoulis}, title = {Pulmonary infection by SARS-CoV-2 induces senescence accompanied by an inflammatory phenotype in severe COVID-19: possible implications for viral mutagenesis}, elocation-id = {2102951}, year = {2022}, doi = {10.1183/13993003.02951-2021}, publisher = {European Respiratory Society}, abstract = {Background SARS-CoV-2 infection of the respiratory system can progress to a multi-systemic disease with aberrant inflammatory response. Cellular senescence promotes chronic inflammation, named as senescence-associated secretory phenotype (SASP). We investigated whether COVID-19 disease is associated with cellular senescence and SASP.Methods Autopsy lung tissue samples from 11 COVID-19 patients and 43 age-matched non-COVID controls with similar comorbidities were analysed by immunohistochemistry for SARS-CoV-2, markers of senescence and key SASP cytokines. Virally-induced senescence was functionally recapitulated in vitro, by infecting epithelial Vero-E6 cells and a three-dimensional alveosphere system of alveolar type 2 (AT2) cells with SARS-CoV-2 strains isolated from COVID-19 patients.Results SARS-CoV-2 was detected by immunocytochemistry and electron microscopy predominantly in AT2 cells. Infected AT2 cells expressed the angiotensin-converting-enzyme 2 (ACE2) and exhibited increased senescence (p16INK4A and SenTraGorTM positivity) and IL-1β and IL-6 expression. In vitro, infection of Vero-E6 cells with SARS-CoV-2 induced senescence (SenTraGorTM), DNA damage (γ-H2AX) and increased cytokine (IL-1β, IL-6, CXCL8) and Apolipoprotein B mRNA-editing (APOBEC) enzyme expression. Next-generation-sequencing analysis of progenies obtained from infected/senescent Vero-E6 cells demonstrated APOBEC-mediated SARS-CoV-2 mutations. Dissemination of the SARS-CoV-2-infection and senescence was confirmed in extra-pulmonary sites (kidney and liver) of a COVID-19 patient.Conclusions We demonstrate that in severe COVID-19, AT2 cells infected by SARS-CoV-2 exhibit senescence and a proinflammatory phenotype. In vitro, SARS-CoV-2 infection induces senescence and inflammation. Importantly, infected senescent cells may act as a source of SARS-CoV-2 mutagenesis mediated by APOBEC enzymes. Therefore, SARS-CoV-2-induced senescence may be an important molecular mechanism of severe COVID-19, disease persistence and mutagenesis.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/early/2022/01/20/13993003.02951-2021}, eprint = {https://erj.ersjournals.com/content/early/2022/01/20/13993003.02951-2021.full.pdf}, journal = {European Respiratory Journal} }