Forkhead box P3-positive regulatory T cell (FOXP3+ Treg) (FOXP3+ Treg)

Forkhead box P3-positive (FOXP3+) regulatory T cells, commonly known as Tregs, are a specialized lineage of CD4+ T cells essential for maintaining peripheral tolerance and immune homeostasis (Hori et al., Science 2003, PMID: 12612578). They are defined by the expression of the transcription factor FOXP3, which serves as the master regulator of their suppressive genetic program. Tregs function by inhibiting the activity of various immune cells, including effector T cells and antigen-presenting cells, through mechanisms such as the secretion of inhibitory cytokines like IL-10 and TGF-beta, and direct cell-to-cell contact via CTLA-4. In oncology, an abundance of FOXP3+ Tregs in the tumor microenvironment is often associated with poor prognosis, as they shield the tumor from anti-tumor immune responses (Ishida et al., JCO 2012, PMID: 22547592). Conversely, defects in Treg number or function lead to severe autoimmune disorders, such as IPEX syndrome. Therapeutic interventions currently focus on depleting Tregs to enhance cancer immunotherapy or expanding them using low-dose IL-2 or rapamycin to treat autoimmune diseases and prevent organ transplant rejection (Saadoun et al., NEJM 2011, PMID: 21879887).

Other names

Regulatory T cellTregCD4+CD25+FOXP3+ T cellSuppressor T cellCD4+ regulatory T cell

Modulation of regulatory T cell activity through selective depletion to enhance anti-tumor immunity, or expansion and functional enhancement to restore self-tolerance in autoimmune conditions.