Regulatory T cell (CD4⁺CD25⁺Foxp3⁺) (Treg cell)

Regulatory T cells (Treg cells) are a distinct subset of CD4-positive T lymphocytes marked by high expression of CD25 (the alpha chain of the IL-2 receptor) and the transcription factor forkhead box P3 (Foxp3)[3][6][5]. They are thymus-derived ("natural" Tregs) or induced in the periphery ("induced" Tregs)[3]. Treg cells play an essential role in the maintenance of immune homeostasis by suppressing activation, proliferation, and cytokine production of autoreactive and effector T cells, mainly through cell-cell contact and release of suppressive mediators. Their activity is crucial for preventing autoimmunity, modulating inflammation, ensuring tolerance to self and transplanted tissues, and regulating responses to pathogens; however, excessive Treg activity can impair anti-tumor immunity and increase risk of infections[3][4][5][6]. Key functional and phenotypic markers include CD4, CD25, and Foxp3, as well as CTLA-4 and GITR[3][5][6][7]. Drugs such as rapamycin and low-dose IL-2 influence Treg function and are studied for their potential to treat autoimmune and inflammatory diseases[9][2][1][5].

Other names

Natural regulatory T cellnTreg cellCD4⁺CD25⁺ Treg cellFoxp3⁺ regulatory T cell

Expansion or induction of Treg cells (e.g., rapamycin increases Treg numbers); Modulation of Treg suppressive function (e.g., cytokines such as IL-2 or TGF-β induce Foxp3 expression); Inhibition of effector T cell proliferation and cytokine production through cell-cell contact, soluble mediators, and transcriptional repression