Tuning microenvironments: induction of regulatory T cells by dendritic cells.

The body requires the generation of regulatory T (Treg) cells to preserve its integrity. Each microenvironment is controlled by a specific set of regulatory elements that have to be finefrly and constantly tuned to maintain local homeostasis. These environments could be site specific, such as the gut environment, or induced by chronic exposure to microbes or tumors. Various populations of dendritic cells (DCs) are central to the orchestration of this control. In this review, we will discuss some new findings associating DCs from defined compartments with the induction of antigen-specific Treg cells.