Regulatory T cells in hepatic circadian rhythm

Regulatory T cells (Treg cells) are important to maintain self-tolerance. In tissues, Treg cells can perform non-classical functions, for example, they are implicated in regulating metabolic processes in the adipose tissue. Their function in the liver is less well understood. We found here that Treg cells are important to secure the peripheral hepatic circadian rhythm of core-clock regulators and clock-controlled genes. Undisturbed metabolism in the liver required the presence of Treg cells and was especially important in the early postnatal phase, a distinct time period at around day 10, when the liver had not fully matured and Treg cells proliferated and accumulated in the liver-tissue. Our findings highlight a critical role for Treg cells to establish and maintain liver homeostasis.