Activated regulatory T cell (aTreg) (aTreg)

Activated regulatory T cells (aTregs), also known as effector regulatory T cells (eTregs), are a highly suppressive subset of CD4+ T lymphocytes characterized by the expression of the transcription factor FOXP3 and high levels of the IL-2 receptor alpha chain (CD25) [2, 3]. Unlike resting or naïve Tregs, aTregs are antigen-experienced and exhibit potent immunomodulatory activity through the secretion of inhibitory cytokines such as IL-10 and TGF-beta, as well as the expression of checkpoint molecules like CTLA-4 and TIGIT [7, 15]. In oncology, aTregs frequently infiltrate the tumor microenvironment, where they suppress anti-tumor immune responses and contribute to immune evasion, making them a primary target for depletion or functional inhibition [5, 14]. Conversely, in autoimmune diseases and transplantation, therapeutic strategies aim to expand or induce aTregs to restore immune tolerance and prevent tissue damage [8, 12]. Drugs such as ipilimumab and mogamulizumab target markers on these cells to reduce their numbers in cancer, while low-dose IL-2 is used to selectively expand them in inflammatory conditions [7, 9]. Although 'Activated regulatory T cells' refers to a cell population rather than a single molecule or receptor, it is a critical focal point for modern immunotherapy development [1, 16].

Other names

Effector regulatory T celleTregActivated TregSuppressor T cell (activated)

Regulatory T cell depletion, Regulatory T cell expansion, Inhibition of immunosuppressive activity, Blockade of inhibitory receptors