Neutrophil depletion ameliorates lung inflammation and prolongs survival. (A) Neutrophil depletion or G-CSF neutralization resulted in increased survival of MTB-infected Card9^−/− mice, Kaplan-Meier curves, and log-rank test. (B) Giemsa staining of infected lungs 24 d p.i. showed that granulocyte depletion ameliorated lung inflammation. (C) PMN depletion limited parenchyma infiltration with MPO⁺ cells. (D) PMN depletion reduced circulating levels of MPO and (E) PMN numbers (n = 4–6). Data are representative of one (G-CSF) or two (Gr-1) independent experiments (n = 5–10; 24 and 21 d p.i., respectively). Two-way ANOVA and Bonferroni method were applied for statistical analyses. Bars: (B) 2.5 mm; (C) 100 µm. **, P < 0.01; ***, P < 0.001.