Article Figures & Data
Figures
- FIG. 1.
Cigarette smoke exposure increases pulmonary bacterial burden and worsens clinical signs of pneumococcal pneumonia. Female BALB/c mice were exposed to room air (open bars) or cigarette smoke (CS) (solid bars) for 5 weeks, followed by an intratracheal challenge with live S. pneumoniae (104 CFU). (A) Lung homogenates were assessed for bacterial burdens at 24 and 48 h postinfection. (B) The clinical appearance was evaluated 6 h after infection and every 12 h thereafter, as described in Materials and Methods. (C) Core temperatures were taken at the time of euthanasia, and data are presented as changes from baseline (core temperature of mice that were not infected). Bars represent means ± standard errors of the means (n = 7 or 8 mice per group). *, P < 0.05 compared with air-exposed mice at the same time point, by ANOVA (A and C) and the Kruskal-Wallis test (B).
- FIG. 2.
Cytokine levels in lung homogenates obtained from mice following an intratracheal challenge with live S. pneumoniae. Female BALB/c mice were exposed to room air (open bars) or cigarette smoke (CS) (solid bars) for 5 weeks, followed by an intratracheal challenge with live S. pneumoniae (104 CFU). Homogenates were prepared from lungs removed from euthanized mice at 24 and 48 h postinfection and were assessed for IL-1β, IL-6, IL-10, MIP-2, and TNF-α as described in Materials and Methods. *, P < 0.05 versus air-exposed mice, by t test.
- FIG. 3.
Elevated neutrophil counts in cigarette smoke-exposed mice following intratracheal challenge with heat-killed S. pneumoniae. Leukocytes were obtained by bronchoalveolar lavage from mice exposed to room air (open bars) or cigarette smoke (CS) (solid bars) for 5 weeks, with no subsequent challenge (A) or 24 h (B) or 48 h (C) following an intratracheal challenge with heat-killed S. pneumoniae (106 CFU-equivalent dose). Differential counts were calculated by multiplying total cell counts by the percentages of lymphocytes (Lymph), neutrophils (PMN), and monocytes/macrophages (Mono/Mac) following differential staining. Bars represent means ± standard errors of the means (n = 4 to 6 mice per group for panel A and 7 or 8 mice per group for panels B and C). *, P < 0.05 by paired t test.
- FIG. 4.
Cytokine levels in lung homogenates obtained from mice following intratracheal challenge with heat-killed S. pneumoniae. Female BALB/c mice were exposed to room air (open bars) or cigarette smoke (CS) (solid bars) for 5 weeks, followed by an intratracheal challenge with S. pneumoniae (106 CFU). Lung homogenates were assessed for IL-1β, IL-6, IL-10, MIP-2, and TNF-α as described in Materials and Methods. *, P < 0.05 versus air-exposed mice, by t test.
- FIG. 5.
Cigarette smoke extract impairs complement-mediated phagocytosis of S. pneumoniae by AMs in vitro. (A) AMs were cultured overnight with medium alone (control) (open bar) or with medium containing 1% CSE (solid bars), and phagocytosis of S. pneumoniae opsonized with normal rat serum (NS), heat-inactivated rat serum (HIS), C3-deficient serum (C3-DS), or no serum (UNOP) or of IgG-coated microspheres (IgG-MS) was assessed as described in Materials and Methods. (B) Female BALB/c mice were exposed to room air (open bars) or cigarette smoke (CS) (solid bars) for 4 h, and AMs were recovered by lavage and cultured overnight. On the following day, phagocytosis of S. pneumoniae opsonized with normal rat serum (NS) or C3-deficient serum (C3-DS) was assessed. Data were normalized to their respective controls. Bars represent the means ± SEM for three to five experiments. *, P < 0.05 compared with control AMs, by ANOVA.
