CD4-positive, CD25-positive regulatory T cell (Treg)

CD4-positive, CD25-positive regulatory T cells (Tregs) are a specialized subpopulation of T lymphocytes essential for maintaining immune homeostasis and peripheral self-tolerance. Characterized by high surface expression of CD25 (IL-2 receptor alpha chain) and the master transcription factor FOXP3, these cells suppress excessive or autoreactive immune responses through the secretion of anti-inflammatory cytokines, such as IL-10 and TGF-beta, and direct cell-to-cell contact. In the context of oncology, tumors often recruit or induce Tregs to create an immunosuppressive microenvironment, thereby effectively evading the host's anti-tumor immunity and promoting cancer progression. Conversely, a deficiency in Treg number or functional capacity is a primary driver of various autoimmune and inflammatory diseases, including rheumatoid arthritis, type 1 diabetes, and graft-versus-host disease. Therapeutic interventions targeting Tregs aim to either selectively deplete them using monoclonal antibodies like daclizumab to enhance anti-cancer immunity or pharmacologically expand and induce them using low-dose interleukin-2 or rapamycin to restore immune tolerance.

Other names

Regulatory T cellTregCD4+ CD25+ TregCD4+ CD25+ FoxP3+ T cellSuppressor T cell

Therapeutic strategies involve the selective depletion of regulatory T cells via antibody-dependent cellular cytotoxicity or receptor blockade to enhance anti-tumor immunity in oncology, or the pharmacological expansion and induction of these cells via IL-2 signaling and mTOR inhibition to restore immune tolerance in autoimmune conditions.