Figure 1. Effect of flagellin on mucus secretion and lung inflammatory response induced by P. aeruginosa infection.

C57BL/6 female mice were infected for 24 hours with wild type P. aeruginosa strain (PAK) or its flagellin-deficient mutant (ΔFliC), (5 × 10⁶ CFU), as indicated in Material and Methods. (A) Shows muc5ac expression in lungs of PAK-infected compared to ΔFliC-infected mice and (B) Shows muc2 expression in lungs of PAK- and ΔFliC-infected mice. (C) Shows muc5b expression in lungs of PAK- and ΔFliC-infected mice. (D) Shows histological analysis with Alcian blue staining of the lung. The photographs were taken using a 40× magnification. The arrows point to mucus producing cells as stained by the blue (Alcian blue-positive cells). (E) Shows the number of Alcian blue-positive cells that were calculated from 3 independent experiments (5 mice in each group). (F) Shows bacteria amounts (CFU) in the lung detected 24 h following infection with 5 × 10⁶ CFU of either PAK- or ΔFliC. (G) Compares PMN influx in the lung of PAK- and ΔFliC-infected mice. (H) Shows the amount of KC pro-inflammatory cytokine produced in the lung of mice (n = 5), 24 h post-infection with 5 × 10⁶ CFU. nd  =  no detected, ns =  not significant. ***P<0,001, **P<0.01 when comparing to PBS; &&& P<0.001, && P<0.01 when comparing ΔFliC to PAK infected lungs.