Pseudomonas aeruginosa infection causes lysosomal dysfunction in the cystic fibrosis bronchial epithelium

Cystic fibrosis (CF) is a genetic disorder that causes chronic airway disease, leading to accelerated aging, inflammation, and susceptibility to opportunistic infections. Pseudomonas aeruginosa (PA) is prevalent in the CF lung, often multidrug-resistant, and affecting lung function decline, highlighting a need for alternative treatment strategies, such as host-directed therapeutics. The PA metabolite pyocyanin can induce senescence-associated β-galactosidase (SA-βgal), a lysosomal cell senescence marker. However, whether PA can induce cell senescence and therefore affect immune functions has not been studied. Using established airway epithelial culture models, we observed that PA infection increased SA-βgal activity and proinflammatory cytokines without increasing a comprehensive set of cell senescence markers. PA infection also resulted in lysosomal neutralization and decreased lysosome biogenesis, with the latter attenuated by rapamycin (RAPA), a senolytic and an established inhibitor of mTOR signaling. In conclusion, our study implies that PA infection does not induce cell senescence in the CF bronchial epithelium but disturbs lysosomal homeostasis, which can be attenuated by RAPA. These findings highlight lysosomal health as a promising therapeutic target in CF airways, especially as patients live longer yet remain susceptible to recurrent airway infections.