Production of IL-17 by γδ T cells. Intracellular cytokine staining following influenza challenge demonstrates an increasing percentage of IL-17+
γδ T cells (A), even as the total population of γδ T cells expands (B) Percentage of IL-17+
αβ T cells is unchanged compared with naive mice (C) Challenge of γδ knockout mice results in lower levels of IL-17A and IL-17F message, expressed as fold change from naive, at 6 dpi (D). *, p = 0.03; **, p = 0.02, n = 8/time point.