Th17 cells: from precursors to players in inflammation and infection

Upon activation, naive CD41 T cells differentiate into different lineages of effector Th subsets. Each subset is characterized by its unique cytokine profile and biological functions. Th17, a newly described Th subset that produces IL-17, IL-17F and IL-22 in preference to other cytokines, has been shown to play an important role in clearing specific pathogens and in inducing autoimmune tissue inflammations. Over the last 2–3 years, significant progress has been made to understand the development and biological functions of Th17 subset. Transforming growth factor b (TGF) togethe