Fig. 4

Macrophage Lkb1-deficient mice have a reduced capacity to produce TNFα in the lung upon infection with non-encapsulated S. pneumoniae, whilst bacterial outgrowth and neutrophil influx are unaltered. Mice were inoculated intranasally with approximately 1 × 10⁸ colony-forming units (CFUs) of Spneu D39Δcps and euthanized 5 h thereafter for determination of bacterial loads (CFUs per milliliter) in the lung (A), total number of neutrophils (CD11c^negLy6G^pos) and alveolar macrophages (AMs), and fractional contribution of “classic” AMs (cAMs) (CD11c^posSiglecF^highCD11b^neg) and “non-classic” AMs (ncAMs) (CD11c^posSiglecF^lowCD11b^pos) in BALF (B) and cytokine and chemokine (TNFα, IL-6, CXCL1, CXCL2 and MPO) levels in BALF (C). Data are shown as bar graphs with mean ± SD representing 7 mice per group. Bacterial loads (A) and cytokine levels (C) of Stk11-ΔM mice were compared to littermate controls using the Mann–Whitney U test, and cells counts (B) were compared by student’s t-test. *P < 0.05