γδ T cells in infection and autoimmunity

Standing at the interface of innate and adaptive immune, γδ T cells play important pathophysiologic roles in infection, autoimmunity, and tumorigenesis. Recent studies indicate that γδ T cells could be categorized into IFN-γ⁺ and IL-17⁺ subsets, both of which possess select TCR usages, bear unique surface markers and require different cytokine signaling to maintain the homeostasis. In addition, as the major innate IL-17 producers, γδ T cells are increasingly appreciated for their involvement in various acute infections and injuries. This review will summarize the characteristics of IFN-γ⁺ (γδ T-IFN-γ) and IL-17⁺ γδ T cells (γδT17) and discuss their distinct pathogenic functions in different disease models.