The interplay between regulatory T cells and metabolism in immune regulation

Regulatory T cells (Tregs) are crucial for peripheral tolerance and are intimately involved in immunological diseases and cancer. Recent studies have highlighted a key role for Tregs in metabolic disorders, for instance as they accumulate in the adipose tissue to protect against obesity-related inflammation and insulin resistance. Conversely, the generation and immunosuppressive functions of Tregs are influenced by both systemic and cellular metabolism. The nutritional status as well as metabolic cues such as those provided by leptin impinge upon the proliferation of Tregs. In addition, the mTOR-dependent lipid metabolism has a crucial role in programming the activity of Tregs under steady-state conditions as well as upon activation. This review discusses the intricate interaction between Tregs and metabolism, focusing on the roles of Tregs in systemic and local metabolic circuitries as well as on the regulation of Treg abundance and function by metabolic signals.