Flagellin from Pseudomonas aeruginosa increases the expression of the SARS-CoV2 entry protease TMPRSS2 in airway epithelial cells

In this report we showed that and its virulence factor flagellin (Fla-PA), a ligand of Toll-Like receptor 5 are able to increase TMPRSS2 expression in control and CF AEC. In contrast, no effect was observed with recombinant flagellin, used as an adjuvant in the clinical development of new vaccines against respiratory viruses. Considering the urgency of the health situation, this result is of major significance for patients with CRD (COPD, CF) which are frequently infected and colonized by during the course of the disease. In the general population, a ventilator-associated pneumonia in SARS-CoV-2 patients under intubation in intensive care units could be also deleterious and should be monitored with care.