(A) Kinetic analysis of clodronate liposome (clodronate; 350 μg/dose, 2 doses) treatment for S. pneumoniae infection after RSV infection. (B) The number of interstitial and resident alveolar macrophages and dendritic cells in the lung of control liposome-treated and clodronate liposome–treated naive mice or mice on day 8 after RSV infection. (C) Changes in the survival rate and (D) body weight of clodronate-treated or control (liposome)-treated mice infected with S. pneumoniae. (E) S. pneumoniae loads in the BAL fluid from clodronate-treated mice infected with S. pneumoniae. (F) Representative H&E-stained lung tissue sections from clodronate-treated mice on day 1 after S. pneumoniae infection. Scale bars: 200 μm (upper), 50 μm (lower). (G) Numbers of inflammatory cells in the BAL fluid from each treatment group on day 1 after S. pneumoniae infection. (H) The levels of IFN-γ in the BAL fluid from each treatment group on day 1 after S. pneumoniae infection. The data are expressed as mean ± SEM; n = 10 (C and D), n = 4–6 (except for C and D). Representative results from 2 independent experiments are shown. The following statistical tests were used: 1-way ANOVA (B, E, G, and H) and Gehan-Breslow-Wilcoxon test (C). *P < 0.05; **P < 0.01; ****P < 0.0001.