CD4+CD25- conventional T cell (Tconv)

CD4+CD25- conventional T cells (Tconv) are a primary subset of helper T lymphocytes that play a central role in orchestrating the adaptive immune response. Unlike regulatory T cells (Tregs), which express high levels of CD25 and the transcription factor FoxP3, conventional T cells are characterized by the absence of these markers in their resting state and their ability to proliferate and secrete pro-inflammatory cytokines upon activation (NIH, 2024). They recognize antigens presented by MHC class II molecules on antigen-presenting cells, leading to their differentiation into various effector subsets (e.g., Th1, Th2, Th17) that direct the immune system to combat pathogens or tumors. In many diseases, the balance between Tconv and Tregs is disrupted; for instance, Tconv activity is often suppressed by Tregs in the tumor microenvironment, while their overactivity can lead to autoimmune disorders (PubMed). Consequently, Tconv cells are a major focus of therapeutic strategies, including checkpoint inhibition to enhance their anti-tumor activity and immunosuppressive agents to dampen their response in inflammatory conditions (StatPearls, 2024).

Other names

TconvT responderTrespEffector CD4+ T cellHelper T cellCD4+CD25- T cell

Therapeutic agents modulate these cells through several mechanisms: inhibition of the T cell receptor (TCR) complex (e.g., anti-CD3 antibodies), inhibition of calcineurin-dependent signaling (e.g., cyclosporine), blockade of the mTOR pathway (e.g., sirolimus), or inhibition of immune checkpoints such as PD-1 and CTLA-4 to enhance effector function (NIH, 2024; PubMed).