Fig. 5.
Blockade of endogenous IFN-β dampens bacterial clearance, reduces generation of proresolving lipid mediators, and delays the resolution of lung inflammation. Female C57BL/6 mice were first injected with a rat anti-mouse IFN-β mAb or rat IgG (both at 50 ng/g b.w., i.p.) followed by intratracheal instillation of 5 × 106 live E. coli. Mice were killed at the indicated times and lung tissue E. coli content (A), lavage fluid neutrophil number (B), and monocyte/macrophage number (C), the percentage of annexin-V positive neutrophils (identified as Ly6G-positive cells) (D), the percentage of macrophages with apoptotic bodies (E), lavage fluid protein (F), 15-epi-LXA4 (G), and RvD1 levels (H) were determined. Results are means ± SEM (n = 4 mice for E. coli plus IgG; n = 6 mice per group for the other groups). *P < 0.05, **P < 0.01, ***P < 0.001 (Dunn’s multiple contrast hypothesis test).