Phenotypical and functional specialization of FOXP3+ regulatory T cells

TReg cells 'walk the line' by preventing autoimmunity while allowing the formation of protective antipathogen and antitumour immune responses.TReg cells can be divided, based on their expression of activation and homing receptors, into populations with distinct migratory, functional and homeostatic characteristics.TReg cells accumulate within both lymphoid and non-lymphoid tissues, and the proper localization of TReg cells is critical to their ability to function and maintain immune homeostasis in vivo.TReg cells use distinct molecular programmes to restrain TH1, TH2 and TH17 cell-mediated immune responses.TReg cells can alter their phenotype and function in response to molecular cues such as cytokines and vitamin metabolites that are present in the immune environment.The phenotypical and functional stability of TReg cells remains controversial, and different experimental systems have yielded conflicting results regarding the ability of TReg cells to convert to other pro-inflammatory T cell lineages.