Lung macrophages exhibit biased expression of IL-10R. (A) IL-10R expression by immune cells in the lungs of memory mice shown as representative flow cytometry plots. (B) Quantification of IL-10R expression by lung immune cells in memory mice shown as MFI for each lineage (left), percent IL-10R⁺ for each lineage (middle), and the lineage composition of total IL-10R⁺ cells in the lungs (right). Data are compiled from three independent experiments (n = 12 mice). Boxes indicate interquartile range with a line drawn at the mean; whiskers indicate the minimum and maximum values. Statistical significance was determined by one-way ANOVA. (C) TNF-α production by lung macrophages in the primary (red) or secondary (blue) response shown in representative flow cytometry plots of intracellular cytokine staining (left, numbers denote percent TNF⁺) and MFI at 3 dpi from three to four mice/group (right). Data are representative of three independent experiments. (D) Kinetics of macrophage-derived TNF-α production determined by intracellular cytokine staining. Graphs show percentage and numbers of TNF-α⁺ lung macrophages. Data are representative of three independent experiments, with n = 3–4 mice per time point and condition. Statistical significance for MFI analysis was determined by Student’s t test, and for quantification of TNFα⁺ macrophage kinetics by two-way ANOVA. ****P ≤ 0.0001; ***P ≤ 0.001; **P ≤ 0.01; *P ≤ 0.05.