Fig. 1.

Schematic overview of ex vivo phagocytosis assay. Pneumonia is induced in mice via oropharyngeal aspiration of Pseudomonas aeruginosa (PsA) or LPS. Bronchoalveolar lavage (BAL) cells are then collected and incubated with pHrodo-PsA ex vivo to evaluate phagocytosis. pHrodo-PsA only fluoresces within the acidified phagosome of neutrophils; adherent bacteria remain nonfluorescent. Upon flow cytometric analysis, neutrophils are identified via Ly6G staining and assessed for pHrodo-PsA positivity.