Abstract
Cytokine responsiveness is a critical component of the ability of cells to respond to the extracellular milieu. Transcription factor-mediated regulation of cytokine receptor expression is a common mode of altering responses to the external environment. We identify the transcription factor Twist1 as a component of a STAT3-induced feedback loop that controls IL-6 signals by directly repressing Il6ra. Human and mouse T cells lacking Twist1 have an increased ability to differentiate into Th17 cells. Mice with a T cell-specific deletion of Twist1 demonstrate increased Th17 and T follicular helper cell development, early onset experimental autoimmune encephalomyelitis, and increased antigen-specific antibody responses. Thus, Twist1 has a critical role in limiting both cell-mediated and humoral immunity.