Th17 cells are found in lymphoid organs after BMT. Lethally irradiated (850 cGy) BALB/c mice were reconstituted with 5 × 10⁶ WT TCD-BM and 0.5 × 10⁶ CD4⁺ T cells. One representative staining for intracellular IFN-γ and IL-17 on CD4⁺ T cells from (A) untreated B6 mice (n = 5) and donor-derived CD4⁺ T cells from the MLN from mice with GVHD (B) on day 14 (n = 8) and (C) day 21 after BMT (n = 9). The absolute number of donor-derived CD4⁺ T cells expressing IL-17, IL-17F, or IL-22 in the (D-F) spleen, (G-I) MLN, and (J-L) PLN on days 7 (syngeneic n = 10; allogeneic n = 16), 14 (syngeneic n = 10; allogeneic n = 14), and 21 (syngeneic n = 5; allogeneic n = 14) after BMT. The mean and SD of each group is shown. Data represent 2 combined experiments. *P ≤ .05, **P ≤ .01, ***P ≤ .001.