Glutaredoxin-1 Attenuates S-Glutathionylation of the Death Receptor Fas and Decreases Resolution of Pseudomonas aeruginosa Pneumonia

Rationale: The death receptor Fas is critical for bacterial clearance and survival of mice after Pseudomonas aeruginosa infection.Objectives: Fas ligand (FasL)–induced apoptosis is augmented by S-glutathionylation of Fas (Fas-SSG), which can be reversed by glutaredoxin-1 (Grx1). Therefore, the objective of this study was to investigate the interplay between Grx1 and Fas in regulating the clearance of P. aeruginosa infection.Methods: Lung samples from patients with bronchopneumonia were analyzed by immunofluorescence. Primary tracheal epithelial cells, mice lacking the gene for Grx1 (Glrx1−/−), Glrx1−/− mice treated with caspase inhibitor, or transgenic mice overexpressing Grx1 in the airway epithelium were analyzed after infection with P. aeruginosa.Measurements and Main Results: Patient lung samples positive for P. aeruginosa infection demonstrated increased Fas-SSG compared with normal lung samples. Compared with wild-type primary lung epithelial cells, infection of Glrx1−/− cells with P. aeruginosa sho...