Extended Data Fig. 6: Macrophage subsets in the lung, ex vivo M.tb killing by alveolar macrophages from CCR2KO mice, and role of IFN-γ in induction of memory alveolar macrophages.

(a & b) Representative dotplots of SiglecF⁺Ly6C⁻ alveolar macrophages (AM) gated on CD64⁺CD24⁻ macrophages in the airway and lung tissue at 2-wk post-PBS treatment or BCG vaccination, & Monocyte-derived (MDM) and interstitial (IM) macrophages in lung tissue were identified as SiglecF⁻Ly6C⁺ and SiglecF⁻Ly6C⁻, respectively. Total numbers of different macrophage subsets in the airway and lung tissues are presented in the bar graphs. (c) Mycobacterial killing capacity of airway AM from 5-wk BCG⁻vaccinated or PBS-treated CCR2KO animals was assessed by ex vivo killing assay. Total numbers of intracellular M.tb CFU were assessed at 24 hr after ex vivo infection. Each point represents biologically independent samples (*p = 0.0351). n = 3 wells/PBS; n = 4 wells/BCG. Data are presented as mean ± SEM. (d) Frequencies of TNF-producing airway AM (unstimulated-US vs stimulated -S) from PBS control, BCG-vaccinated or BCG-vaccinated/IFNγ-depleted animals (*p = 0.0031). n = 3 mice/group. Data are presented as mean ± SEM. and data in d are analyzed by one-way ANOVA for multiple comparison followed by Bonferroni’s test. Statistical analysis for data in c was determined by two-tailed t test.