Figure 5.

Lung myeloid cell subsets in naive and pneumococcal polysaccharide conjugate-vaccinated mice infected with pneumococcus alone or coinfected with influenza virus and pneumococcus. The mice were inoculated intranasally (i.n.) with phosphate-buffered saline (PBS) or 10 plaque-forming units of PR8 influenza and then 1 week later, challenged i.n. with 2 × 10⁶ colony-forming units of A66.1 S. pneumoniae. Lung cell subsets were analyzed 48 hours later by flow cytometry as described in “Material and Methods” section. The cells were defined as follows: neutrophils, Ly6G⁺CD11b⁺F4/80⁻; dendritic cells, CD11c⁺F4/80⁻Ly6G⁻; alveolar macrophages, F4/80⁺CD11c⁺CD11b⁻Ly6G⁻; monocytes/tissue macrophages, CD11b⁺F4/80⁺Ly6G⁻. Each group consisted of 5–7 mice. The data represent means ± SD. *P < .05, **P < .01, ***P < .001, ****P < .0001.