Figure 5.

Flagellin treatment before P. aeruginosa infection dampens lung inflammation in wild-type and cystic fibrosis pigs. (A–D) Lung sections were stained 24 hours after infection with hematoxylin and eosin. Images are shown of PBS-treated and infected pig (PBS–PAK) (A and B) and flagellin-treated and infected pig (Flagellin–PAK) (C and D). (E) Wild-type pigs (n = 5) received a bronchial administration of 0.012-mg/kg FliC_Δ174–400 or PBS and were infected or not with 10 ml of a 10⁷-cfu/ml suspension of the P. aeruginosa strain PAK 24 hours later. The inflammatory response was evaluated 24 hours after infection. CCL20 and CXCL8 gene expression amounts were evaluated by using quantitative PCR analysis. Gene expression is shown relative to the PBS-treated, noninfected group. Data were analyzed by two-way ANOVA, using flagellin administration and P. aeruginosa infection as factors, which was followed by a Tukey HSD post hoc test. (F) Quantitative PCR analysis of precision-cut lung slices from newborn CFTR^+/+ and CFTR^−/− piglets treated or not with 100-ng/ml FliC_Δ174–400 for 24 hours and later infected with the P. aeruginosa strain PAK (multiplicity of infection = 0.2) for 0, 0.5, 1, 2, and 5 hours. Gene expression is shown relative to the mock group (nontreated and noninfected samples). Intergroup differences were analyzed by two-way ANOVA using time and treatment as factors, which was followed by a Tukey HSD post hoc test. Data are representative of three experiments. Scale bars: A and C, 500 μm; B and D, 50 μm.