Transcriptional regulatory networks in Th17 cell differentiation.

Upon encountering antigen in the context of antigen presenting cells, naïve CD4(+) T cells undergo differentiation into effector T helper (Th) cells, which can secrete high levels of cytokines and other immunomodulators to mediate host defense and tissue inflammation. During the past three years, the immunology field has witnessed an explosion of research advances in the biology of Th17 cells, the most recently described subset of T helper cells, which play crucial roles in host immunity and inflammation. Here we review emerging data on transcriptional regulatory networks that govern the differentiation program of Th17 cells, and focus on how the orphan nuclear receptor RORgammat coordinates this process in concert with diverse cytokine-induced transcription factors.