Multiple subsets of regulatory T-cells

Regulatory T-lymphocytes play a central role in the immunological tolerance system. To date, existence of many different subpopulations of regulatory T-cells have been described. However, a number of questions related to the function, differentiation, and homeostasis of these subpopulations in a body remain unclear. Interactions between the previously discovered pairs of helper and regulatory T-lymphocytes require further study. The main topic is identification and establishment of the functions of regulatory memory cells. Interstitial migration of activated regulatory T-lymphocytes is also a promising direction. In this review, we summarized the main findings in multiple subsets of regulatory T-lymphocytes, discussed unclear data that will require further studies, and showed an application for regulatory T-lymphocytes in medicine.