Principles of regulatory T cell function

Regulatory T (Treg) cells represent a distinct lineage of cells of the adaptive immune system indispensable for forestalling fatal autoimmune and inflammatory pathologies. The role of Treg cells as principal guardians of the immune system can be attributed to their ability to restrain all currently recognized major types of inflam-matory responses through modulating the activity of a wide range of cells of the innate and adaptive immune system. This broad purview over immunity and inflammation is afforded by the multiple modes of action Treg cells exert upon their diverse molecular and cellular targets. Beyond the suppression of autoimmunity for which they were originally recognized, Treg cells have been implicated in tissue maintenance, repair, and regeneration under physiologic and pathologic conditions. Herein, we discuss the current and emerging un-derstanding of Treg cell effector mechanisms in the context of the basic properties of Treg cells that endow them with such functional versatility.

Automated summary

Regulatory T (Treg) cells are essential cells of the adaptive immune system that prevent fatal autoimmune and inflammatory diseases. They restrain various types of inflammatory responses by modulating the activity of different cells in the immune system. In addition to their role in suppressing autoimmunity, Treg cells also play a part in tissue maintenance, repair, and regeneration. This article discusses the current understanding of Treg cell effector mechanisms and their functional versatility.