Removal of Cif catalytic activity decreases recovered CFU counts and increases the amount of 15-epi-lipoxin A4 (LXA4) detected in an acute pneumonia model. A: immunoblot of Cif from PA14 and PA14-CifD129S in the absence (1:4 sample dilution) and presence (1:20 sample dilution) of an epoxide inducer. Blots generated at the same time and processed in parallel. B: ratio of recovered CFUs at 24 h postinfection to input CFUs from LH of mice treated with PA14 or PA14-CifD129S (n = 4 experiments, 4–6 mice for each treatment group/experiment; significance calculated using a 1-tailed exact Wilcoxon-Mann-Whitney test from the R package coin.). The gray box indicates those mice where no CFUs were detected. C: representative plots from BALF samples gated on live CD45+CD11b+ markers. Thin-lined black boxes indicate the CD11c+F4/80+ macrophage population, with the percent of parent gate indicated above the black box; thick-lined black boxes indicate the F4/80−CD11c− population displayed in D. D: representative plots from BALF samples gated on live CD45+CD11b+CD11c−F4/80− markers. Black inset boxes indicate the Ly6G+Ly6Cint neutrophil population, with the percent of parent gate indicated below the black box. E: counts of live CD45+CD11b+CD11c−F4/80− macrophages/ml BALF. Not significant (ns), P > 0.05. F: counts of live CD45+CD11b+CD11c−F4/80−Ly6G+Ly6Cint neutrophils/ml BALF. G: percent of parent gates (live CD45+CD11b+CD11c−F4/80−) composed of neutrophils (Ly6G+Ly6Cint). E-G: n = 2 experiments, 4–6 mice for each treatment group/experiment; F and G: ns, P ≥ 0.2. H: background-subtracted levels of 15-epi LXA4 detected in BALF from mice treated with PBS, PA14, or PA14-CifD129S (n = 4 experiments, 4–6 mice for each treatment group/experiment; ns, P ≥ 0.2.). E–H: black bars, medians; significance calculated using a Kruskal-Wallis Rank Sum test followed by a multiple-comparisons test in the R package “pgirmess.”