CD4+ FoxP3+ regulatory T cell (Treg)

CD4+ FoxP3+ regulatory T cells (Tregs) are a specialized subset of T lymphocytes essential for maintaining peripheral tolerance and preventing autoimmunity by suppressing the activity of effector T cells and other immune components (StatPearls, 2023). They are uniquely identified by the expression of the master transcription factor Forkhead Box P3 (FoxP3), which is vital for their development and suppressive function (UniProt P63313). In oncology, Tregs frequently infiltrate tumors and create an immunosuppressive microenvironment that allows cancer cells to evade detection and destruction by the immune system (PubMed: 28453704). Conversely, a deficiency in Treg number or function is a primary driver of autoimmune disorders like Type 1 Diabetes and IPEX syndrome. Therapeutic strategies involve modulating these cells through the IL-2 receptor (CD25) pathway; for instance, low-dose Aldesleukin is used to expand Tregs in autoimmune contexts, while antibodies like Ipilimumab or Mogamulizumab target Treg-associated markers to enhance anti-tumor immunity (NIH, 2022). Their role as a 'rheostat' of the immune system makes them a high-value target for both immune-oncology and transplant medicine.

Other names

Regulatory T cellsCD4+CD25+ regulatory T cellsSuppressor T cellsFoxP3+ T-regsCD4+CD25+highCD127low regulatory T cells

Drugs targeting this cell population either aim to expand their numbers and suppressive activity to treat autoimmune diseases and transplant rejection (e.g., low-dose IL-2, mTOR inhibitors), or deplete and inhibit them to overcome immune evasion in the tumor microenvironment (e.g., anti-CTLA-4 or anti-CCR4 antibodies).