Fig 3.

Loss of flagellar motility causes reduced caspase-1 activation. BMDC from C57BL/6 mice were infected with the indicated genotype of P. aeruginosa at an MOI of 50. Bacteria were gated out based on scatter controls, and the percentage of active caspase-1⁺ cells was determined. (A) Representative flow cytometry dot plot for the BMDC gating scheme (i) and gated populations analyzed for caspase-1 and CD45 expression (ii, iii, and iv). The dot plots are representative of BMDC infected with wild-type PA14 (ii) or the motAB motCD (iii) or popB (iv) mutant. (B and C) Quantitative analysis of the percentage of caspase-1⁺ cells following infection of BMDC with the indicated wild-type or isogenic mutant strains of P. aeruginosa in the absence (B) or presence (C) of ATP. Data are representative of at least two independent experiments (B and C, n ≥ 5) and expressed as means ± standard deviations. ***, P ≤ 0.001. (D) Macrophages were uninfected (i) or infected with wild-type PA14 (ii and v) or the motABmotCD (iii and vi) or popB (iv) mutant at an MOI of 50 for 2 h. Cells were stained for active caspase-1 (with FAM-YVAD-FLICA) and DNA (with DAPI). Images were acquired at magnifications of ×20 (i to iv) and ×63 (v and vi). Images are representative of at least two independent experiments.