FIG. 6.

Alveolar macrophages but not MTEC respond differently to infection with a translocon-positive versus a translocon-negative P. aeruginosa strain. (A) MTEC were differentiated at an air-liquid interface on Transwell inserts and then infected with 5 × 10⁴ CFU of ΔUT or pcrV bacteria. Bars indicate KC measured in supernatant by ELISA at 4 h.p.i. (means ± standard errors of the means) for 5 to 6 wells; the results are representative of 3 independent experiments and were comparable for MOIs between 0.1 and 10. Each well is plated with MTEC harvested from ca. one mouse trachea. (B) Alveolar macrophages were infected with ΔUT or pcrV bacteria (MOI 10), and secreted IL-1β was measured by ELISA at the indicated times postinfection. Bars indicate means ± standard deviations of the results for triplicate wells; the results are representative of two independent experiments.