Augmented Th1 differentiation in recipients given IL-17^−/− donor cells. (A,B) Serum levels of IFN-γ and TNF-α of recipients given WT or IL-17^−/− donor spleen cells 5 days after HCT. (C) Mesenteric lymph nodes (MLN) and spleen cells of the recipients given WT or IL-17^−/− donor cells were stained for H-2^b, CD4, CD8, and intracellular IFN-γ, 13 days after HCT. Gated H-2^b+ cells are shown in IFN-γ versus CD4 or CD8. The percentage of IFN-γ⁺ cells is shown beside the gating boxes. One representative of 4 recipients in each group is shown. (D,E) Means (± SE) of the percentages of IFN-γ⁺ CD4⁺ or CD8⁺ donor T cells in MLN and spleen.