Figure 5. A BM-derived CD11c⁺ cell population is required for IL-18 secretion in response to Mtb.

(A–G) Percentage of IFN-γ⁺ cells among total lung CD3^–NK1.1⁺ (A, C, and E) and CD3⁺CD8⁺ (B, D, and F) cells and serum IL-18 levels (G) of straight WT or Il18^–/– (A and B) and CD11cDTR BM chimeras (C and D) as well as DTX- and PBS-treated CD11cDTR mixed BM chimeras (E and F) 24 hours after injection of 1 × 10⁸ CFU Mtb H37Rv. (H) Percentage of GFP⁺ cells among total viable splenocytes 24 hours after i.v. or i.t. injection of 1 × 10⁸ CFU Mtb H37Rv or Mtb H37Rv–GFP into naive B6 mice. (I) Uptake of Mtb H37Rv–GFP by individual splenic DC subsets (CD11c⁺MHC-II⁺CD4⁺, CD11c⁺MHC-II⁺CD8⁺, or CD11c⁺MHC-II⁺CD4^–CD8^–) 24 hours after i.v. or i.t. delivery of 1 × 10⁸ CFU. Results are presented as individual data points (A–G) or as pooled data (mean ± SEM) and representative FACS plots (H and I) of 8 to 10 (A–G) or 4 to 6 (H and I) mice per group from 2 (H and I) or 3 (A–G) pooled, independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, by 1-way ANOVA. Mtb-GFP, Mtb H37Rv–GFP; PI, propidium iodide.