Regulatory T cells and broader immune compartment (Tregs)

Regulatory T cells (Tregs) are a specialized subpopulation of T cells, typically defined by the expression of CD4, CD25, and the master transcription factor FOXP3, which play a critical role in maintaining immune homeostasis and self-tolerance (Sakaguchi et al., 2008, Cell). The broader immune compartment refers to the complex network of innate and adaptive immune cells, including effector T cells, B cells, and myeloid-derived suppressor cells, which interact to dictate the overall inflammatory or immunosuppressive state of a tissue. In oncology, the infiltration of Tregs into the tumor microenvironment is a major mechanism of therapeutic resistance, as these cells suppress anti-tumor effector T cell activity (Fontenot et al., 2003, Nature Immunology). Consequently, many modern immunotherapies, such as CTLA-4 inhibitors, aim to modulate this compartment by depleting Tregs or blocking their suppressive signals. In contrast, for autoimmune diseases and organ transplantation, the therapeutic goal is often to expand or stabilize the Treg population to prevent tissue destruction (Vignali et al., 2008, Nature Reviews Immunology). Because this entry describes a heterogeneous cell population and a systemic environment rather than a single protein or receptor, it is classified as a biological system rather than a discrete molecular drug target. Monitoring the balance of these cells through biomarkers like CD127 and Helios is essential for assessing treatment efficacy and potential toxicity (Josefowicz et al., 2012, Annual Review of Immunology).

Other names

TregsSuppressor T cellsImmune microenvironmentRegulatory T-lymphocytesT-reg cells

Therapeutic modulation of the immune compartment involves the depletion of suppressive regulatory T cells to enhance anti-tumor immunity, the expansion of these cells to treat autoimmune diseases, or the blockade of inhibitory checkpoints to restore effector T cell function.