Regulatory T cells and Programmed Cell Death Protein 1 positive CD4+ T cells (Tregs and PD-1+ CD4+ T cells)

Regulatory T cells (Tregs) and Programmed Cell Death Protein 1 positive (PD-1+) CD4+ T cells are critical cellular subsets involved in immune regulation and peripheral tolerance. Tregs, primarily identified by the expression of CD4, CD25, and the master transcription factor Foxp3 (UniProt Q9BZS1), function to suppress excessive immune activation and prevent autoimmune diseases (Sakaguchi et al., 2020, Nature Reviews Immunology). PD-1+ CD4+ T cells are helper T cells expressing the inhibitory checkpoint receptor PD-1 (UniProt Q15116), which often signifies a state of activation or exhaustion following chronic antigen exposure. In the context of oncology, these populations frequently accumulate within the tumor microenvironment, where they contribute to an immunosuppressive milieu that facilitates tumor evasion from the immune system. Therapeutic interventions, such as PD-1 inhibitors like Nivolumab and Pembrolizumab, aim to reinvigorate effector T cell function, although the presence of PD-1 on Tregs themselves can lead to complex outcomes, including the potential enhancement of Treg-mediated suppression (Kamada et al., 2019, PNAS). Understanding the balance and interaction between these populations is essential for optimizing cancer immunotherapy and managing immune-related adverse events.

Other names

TregsRegulatory T-lymphocytesPD-1 positive CD4+ T cellsFoxp3+ CD4+ T cellsCD4+CD25+Foxp3+ T cells

Modulation of immune cell activity through Programmed Cell Death Protein 1 (PD-1) blockade and the depletion or functional inhibition of Regulatory T cells (Tregs) to restore anti-tumor immunity (Kamada et al., 2019, PNAS).