FIG 12.

Egr-1 deficiency leads to increased nitric oxide production and enhanced bacterial intracellular levels in neutrophils and macrophages in response to P. aeruginosa infection. Wild-type (+/+) and Egr-1-deficient (−/−) neutrophils (A to D) and BMMs (E to H) were infected with P. aeruginosa 8821 for various durations. The NO₂− levels in cell lysates (A and E) and supernatants (B and F) were determined at 6 h. The P. aeruginosa neutrophils or macrophages were infected for 1 h and lysed for phagocytosis assay (C and G). The CFU data represent the number of internalized bacteria within 1 h (n = 6 ± SEM; *, P < 0.05). The P. aeruginosa-infected neutrophils or macrophages were infected for 3 h and lysed for bacterial killing assay (D and H). The intracellular killing efficiency was calculated as the number of CFU after 1 h minus the number of CFU after 3 h of infection (1 h CFU − 3 h CFU) (n = 6 ± SEM; *, P < 0.05; **, P < 0.01).