Figure 5

IL-12- and myeloid iNOS expression in the lungs of Mtb-infected mice. IL-12 mRNA expression in total lung homogenate as determined by qPCR (A,B) and iNOS expression assessed by flow cytometry in (C) alveolar macrophages (AM) and (D) inflammatory macrophages and dendritic cells (iM/DC) in the lungs of mice infected with Beijing-1585 (black bars), EAI-1627 (open bars) or H37Rv (grey bars) are compared to uninfected control mice (HC, striped bars). (A) IL-12p35 expression levels are lower in the Beijing-1585 group compared to the EAI-1627 and H37Rv group. (B) IL-12p40 expression is induced in EAI-1627- and H37Rv-infected mice, and reached its peak for both strains at 14 dpi with higher expression in the H37Rv group. Beijing-1585 does not induce any notable expression of either IL-12p35 or IL-12p40 at all time points evaluated. (C) Only AM in the lungs of H37Rv-infected mice at 3,7 and 14 dpi show iNOS expression levels higher than observed in uninfected control mice. (D) also iM/DC in H37Rv-infected mice show higher iNOS expression than iM/DC in the lungs of mice from the Beijing-1585 or EAI-1627 group at all time points evaluated. N = 6 mice per group per time point, *p < 0.05, **p < 0.01, ***p < 0.001 after Bonferroni correction. For experiments depicted in this figure, iM/DC were defined as CD11b^highCD11c^highMHC-II⁺ cells and AM were defined as CD11b^intCD11c⁺F4/80⁺CD200R⁺ cells (gating strategies: Fig. S4A), based on a distinct panel of antibodies. Population frequencies through this gating were highly comparable to those in Fig. 4 (Fig. S4B).