Critical role of IL‐2 and TGF‐β in generation, function and stabilization of Foxp3+CD4+ Treg

Abstract
CD4+Foxp3+ Treg consist of two indistinguishable subsets induced in either the thymus or the periphery. In addition to their suppressive activities, IL-6 can convert natural Treg to pro-inflammatory IL-17-producing cells, but those induced with IL-2 and TGF-β remain Treg. Unlike mouse CD4+CD25 cells, which rapidly become polyclonal Foxp3+CD25+ Treg when activated appropriately with IL-2 and TGF-β, human T cells require multiple stimulations to become similar suppressor cells. See accompanying commentary: http://dx.doi.org/10.1002/eji.200738111