Control of T Helper Cell Differentiation--in Search of Master Genes

Abstract

Naïve T helper (T H 0) cells can differentiate into one of two distinct populations: T H 1 and T H 2. Each population is characterized by the expression of specific cytokines and their ability to participate in cell-mediated or humoral immune responses. Recent efforts at identifying the molecular mechanisms through which T H 0 cells become T H 1 or T H 2 cells have been promising. A number of transcription factors, including GATA-3 and T-bet, have been identified that promote the differentiation of T H 0 cells and the maintenance of the differentiated cell phenotype. Dong and Flavell review recent findings on proteins that control the fate of T H 0 differentiation, whether by promotion or inhibition, and discuss the role of epigenesis in the differentiation process.