Increase frequencies and numbers of Th17 cells during the induction of BM failure in the mouse. CByB6F1 mice were irradiated (5 Gy TBI) and injected with 5 × 10⁶ B6 LN cells. Three B6 LN mice as well as 3 controls (irradiated non–LN-injected, TBI-only) were killed at days 7, 10, 15, and 19 after LN injection. At each time point, BMMCs were stained with anti-CD4, anti-CD8 followed by intracellular IL-17, and IFN-γ antibody and examined by flow cytometry. Experiments are represented as mean ± SD. (A) Absolute numbers of CD4⁺ (top panel) and CD8⁺ (bottom panel) cells in the BM of B6 LN and control mice (TBI-only) at the indicated days after LN injection. (B) Representative flow cytometric analysis at day 15 of IFN-γ (top panels) and IL-17 (bottom panels) expression in CD4⁺ (left panels) and CD8⁺ (right panel) subsets, in TBI-only and LN B6 mice. The mean value of each group is indicated. (C) Absolute numbers of IL-17⁺ and IFN-γ⁺ cells in CD4⁺ (top panel) and CD8⁺ (bottom panel) compartment at the indicated days. Experiments are represented as mean plus or minus SD.