[CD4(+)CD25(+) regulatory T cells and their function in maintaining transplantation tolerance].

This article reviews that as a functionally and phenotypically distict immunoregulatory T cell subpopulation, CD4(+)CD25(+) regulatory T cells can suppress the activation and proliferation of CD4(+)CD25(-) T cells and CD8(+) T cells and the production of IL-2 and IFN-gamma. These regulatory cells play an important role in allograft tolerance, although the mechanisms are not completely understood to date. CD4(+)CD25(+) regulatory T cells can be isolated, activated and expanded in vitro without loss of their immunoregulatory function. The suppressive function of activated CD4(+)CD25(+) cells is antigen non-specific. Ex vivo activated and expanded regulatory T cells have a perspective for practical use.