Programmed Cell Death Protein 1 (PD-1), also known as CD279, is a 288- amino acid type I transmembrane protein expressed on the surface of activated T cells, B cells, and myeloid cells. As an immune checkpoint receptor, PD-1 plays a crucial role in downregulating immune responses and promoting self-tolerance by suppressing T-cell inflammatory activity. PD-1 binds its ligands, PD-L1 and PD-L2, leading to inhibition of T-cell proliferation, cytokine production, and cytotoxic activity.

Human PD-1 is a key target in immuno-oncology and autoimmune disease research. Therapeutic blockade of the PD-1/PD-L1 pathway has shown significant clinical benefits in multiple cancer types by restoring anti-tumor immune responses.

PD-1 Information