PMC:7025480 / 20203-21429 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/7025480","sourcedb":"PMC","sourceid":"7025480","source_url":"https://www.ncbi.nlm.nih.gov/pmc/7025480","text":"Since the previous data implied an involvement of the quorum sensing protein LasR, we again used further clinical CF isolates (CFI-V) and their counterparts with a targeted LasR mutation. In line with the reported importance of LasR in the expression of proteases (6) all LasR deficient CF isolates displayed significantly lower protease activity in CM (Figure 5A). In parallel, all CF isolates with functional LasR were able to suppress the induction of MX1 and OAS1 after RSV infection whereas their LasR deficient counterparts were not (Figure 5B). The most important proteases regulated by LasR are AprA, LasA, LasB, and PrpL. In order to investigate which LasR dependent protease is involved in the modulation of the antiviral response, we used strain PA14 and transposon mutants of PA14 with specific protease deficiency. We observed that even though all protease deficient mutants showed a decrease in total protease activity in CM (Figure 5C), only AprA-deficient PA14 was not able anymore to suppress the induction of antiviral genes MX1 and OAS1 (Figure 5D). These observations indicate that the LasR-regulated protease AprA degrades IFNλ, thereby blocking the induction of the antiviral response upon RSV infection.","tracks":[]}