Figure 1.

Cigarette smoke (CS) increases lung bacterial burden. (A) Total number of BAL cells (n = 6), (B) cell differential (n = 6), and (C–E) percentage of resident macrophages (CD11b^lo/F4/80⁺/CD11c^hi) (n = 3) (C), recruited macrophages (CD11b⁺/F4/80⁺/CD11c⁻/CD206⁻/CCR2⁺/Ly6C⁺) (n = 3) (D), and early inflammatory monocytes (CCR2⁺/Ly6C^hi) (n = 3) (E) from air- and CS-exposed mice (16 cigarettes/d for 10 d). (F) Lung macrophage NOX2 (NADPH oxidase 2)-derived reactive oxygen species (ROS) generation (n = 6) and (G) lung colony-forming units (cfu) from air- and CS-exposed mice infected with vehicle or Streptococcus pneumoniae (10⁷ cfu for 48 h, strain A66.1, type 3) (n = 5). (H) Cell differential, total number (n = 7–8), (I) lung macrophage NOX2-derived ROS generation (n = 5), and (J) lung colony-forming units from mice treated with control or clodronate liposomes and infected with vehicle or S. pneumoniae (n = 7–8). *P < 0.05; **P < 0.001; ***P < 0.0001. Values shown represent means ± SEM. Two-tailed t test statistical analysis was used for A, G, and J. Mann-Whitney U statistical analysis was used for C–E. One-way ANOVA followed by Tukey’s multiple comparison test was performed on B, F, H, and I. Results from A, B, F, and G were repeated at least five times; C–E were conducted once with representative plots of three shown, and H–J were repeated three times. BALC = BAL cells; Clod = clodronate; FITC = fluorescein isothiocyanate; Lymph = lymphocyte; Mac = macrophage/monocyte; PMN = polymorphonuclear neutrophil; S.p. = Streptococcus pneumoniae.