Regulatory T cells and effector T cells (Treg/Teff)

Regulatory T cells (Tregs) and effector T cells (Teffs) are distinct subsets of T lymphocytes that collectively maintain immunological homeostasis and mediate immune responses. Tregs, typically identified by the expression of CD4, CD25, and the master transcription factor Foxp3, function to suppress immune activation and maintain self-tolerance (Sakaguchi et al., 2008, Cell). Conversely, Teffs, which include CD4+ helper cells and CD8+ cytotoxic T cells, are responsible for identifying and eliminating pathogens or malignant cells through the secretion of pro-inflammatory cytokines and direct cytolytic activity (Pardoll, 2012, Nat Rev Cancer). In the context of oncology, an abundance of Tregs within the tumor microenvironment often leads to the suppression of Teffs, allowing for tumor escape from immune surveillance (Facciabene et al., 2012, Cancer Res). Conversely, in autoimmune diseases, a failure in Treg-mediated suppression or an over-activation of Teffs leads to the destruction of healthy tissues. Therapeutic interventions often target the balance between these two populations to restore health. For instance, checkpoint inhibitors like Ipilimumab block CTLA-4 to release Teffs from Treg-mediated inhibition, enhancing anti-tumor immunity (Pardoll, 2012, Nat Rev Cancer). Alternatively, low-dose Interleukin-2 (IL-2) is used to selectively expand Treg populations to treat inflammatory conditions and graft-versus-host disease (Malek, 2008, Annu Rev Immunol). Understanding the interplay between these cells is crucial for developing targeted immunotherapies that can either stimulate or dampen the immune system as needed.

Other names

TregsTeffsT-regulatory cellsT-effector cellsSuppressor T cellsCytotoxic T cellsHelper T cellsCD4+ CD25+ Foxp3+ cellsAntigen-specific T cells

Therapeutic agents modulate the Treg/Teff ratio by either depleting suppressive Tregs to enhance anti-tumor Teff activity or expanding Tregs to suppress pathogenic Teff activity in autoimmune disorders.