Mn stimulates macrophage expression of cytokines related to Th17 differentiation. Lung macrophages were sorted as DAPI⁻ F4/80⁺ CD45^high CD11b^low CD11c^high cells on days 7 and 14 after BMT. Sorting strategies (A) for lung macrophages are shown. Expressions of Il6 (B), Il1b (C), and Il23 (D) messenger RNA in macrophages sorted from Syn controls (white bars), Mn-treated Syn mice (light gray bars), Allo controls (dark gray bars), and Mn-treated Allo mice (black bars) were quantitated by real-time PCR method. Representative data from 3 independent experiments are shown as means ± standard error. (E-F) Levels of IL-6 and TNF-α in the protein extracts from recipients’ lungs on days 7 and 14 are shown as means ± standard error. (G-H) B6D2F1 mice were transplanted from B6-CD45.1⁺ mice. The donor (CD45.1⁺CD45.2⁻) and host (CD45.1⁻CD45.2⁺) neutrophils and macrophages from recipients’ lungs were analyzed on days 7 (G,H) and 14 (H), and representative dot plots (G) and host chimerism (H) are shown. (n = 3-5 per group). *P < .05. n.d., not detected.