Mn administration increases infiltration of Th17 cells in the lung. BMT were performed as shown in Figure 1A. (A) Numbers of donor CD4⁺ T cells, CD8⁺ T cells, and CD11b⁺Ly6G⁺ neutrophils per lung were enumerated on day 14 after after BMT and shown as means ± SE. (n = 4-5 per group). (B) CD3⁺ CD4⁺ cells were sorted and their expression of Ifng, Il4, Foxp3, Il17a, Rorc, and Tgfb3 messenger RNA were determined by quantitative PCR method. (C-G) Mononuclear cells harvested on day 14 after BMT were stained for CD3, CD4, CD8, and intracellular IFN-γ and IL-17A. The gating strategies of staining (C), frequencies (D), and absolute numbers (E) of CD4⁺ IL-17A⁺ T cells, and frequencies (F) and absolute numbers (G) of IFN-γ⁺ CD4⁺ T cells are shown. Data of Syn controls (white bars), Mn-treated Syn (light gray bars), Allo controls (dark gray bars), and Mn-treated Allo (black bars) from one of 5 to 6 independent experiments are shown as means ± standard error. (H,I) Allogeneic recipient mice were intraperitoneally injected with 1 × 10⁷ of heat-killed C albicans on the day of BMT. The frequencies (H) and absolute numbers (I) of IL-17A⁺ CD4⁺ T cells in Allo controls (dark gray bars) and C albicans-treated Allo (black bars) mice are shown. Data from 1 of 2 independent experiments are shown as means ± standard error. *P < .05; **P < .01. n.d., not detected.