Programmed cell death 1 ligand 1 (CD274)

Plays a crucial role in induction and maintenance of immune tolerance to self. As a ligand for the inhibitory receptor PDCD1/CD279, modulates the activation threshold of T-cells and restricts T-cell effector response (PubMed:11015443).

The PDCD1/CD279-mediated inhibitory pathway is exploited by tumors to attenuate anti-tumor immunity and facilitate tumor survival (PubMed:28813417, PubMed:28813410). Through a yet unknown activating receptor, may costimulate T-cell subsets that predominantly produce interleukin-10 (IL10) (PubMed:10581077).