T H 17 Cell Differentiation Is Regulated by the Circadian Clock

Abstract

Lighting Up Immunity T H 17 cells are CD4 + T helper cells that produce the proinflammatory cytokine interleukin-17. In the intestines, T H 17 cells protect the host from fungal and bacterial infections, and their proinflammatory function is linked with autoimmune diseases including inflammatory bowel disease. Yu et al. (p. 727 ) show that the molecular circadian clock directly regulates the differentiation of T H 17 cells in the intestine, which suggest that both nutrition and light are important environmental factors that directly regulate the immune response.