Programmed cell death protein 1 receptor (PD-1)

Programmed cell death protein 1 receptor (PD‑1) is a transmembrane protein expressed primarily on the surface of activated T cells and B cells. It functions as an immune checkpoint that downregulates immune responses by binding its ligands PD-L1 or PD-L2. This interaction suppresses T-cell inflammatory activity and promotes self-tolerance by inhibiting T-cell proliferation and cytokine production. While this mechanism prevents autoimmunity under normal conditions, it can also allow cancer cells to evade immune surveillance. Therapeutic antibodies targeting the PD‑1 pathway block this inhibitory signal to reactivate antitumor immunity in various cancers[1][2][4][6].

Other names

CD279PDCD1Programmed death-1 receptorProgrammed cell death 1 receptor

Immune checkpoint inhibition (blockade of PD‑1/PD‑L1 interaction to enhance T-cell activation and antitumor immunity)[1][4]