ACE2 and TMPRSS2 Expression and Localization in Cystic Fibrosis Lungs: Potential Role in SARS-CoV-2 Susceptibility

Abstract

COVID-19 results from infection by the SARS-CoV-2 virus and causes mild to severe illness. Clinical reports indicate that many severely ill patients present with co-morbidities including severe lung diseases. However, people with cystic fibrosis (pwCF) do not present increased susceptibility to severe COVID-19 outcomes which suggests the presence of protective mechanisms against severe SARS-CoV-2 infection. This project aims to provide an understanding of ACE2 and TMPRSS2 expression and localization, the key proteins involved in SARS-CoV-2 viral entry, in the CF lung to provide insight into potential protective mechanisms against COVID-19 susceptibility in pwCF. Immunohistochemistry and western blot analyses revealed a reduced expression of ACE2 and an increased expression of TMPRSS2 in CF bronchial and alveolar tissues. Our results suggest that changes in ACE2 and TMPRSS2 expression in CF bronchial and alveolar tissue may reduce the opportunity for SARS-CoV-2 entry into host cells and alter the preferred viral entry mechanism.