Description
Plays a critical role in induction and maintenance of immune tolerance to self (PubMed: 11238124). As a ligand for the inhibitory receptor PDCD1/PD-1, modulates the activation threshold of T-cells and limits T-cell effector response (PubMed: 11238124). Through a yet unknown activating receptor, may costimulate T-cell subsets that predominantly produce interleukin-10 (IL10) (PubMed: 11015443, PubMed: 12719480). The PDCD1-mediated inhibitory pathway is exploited by tumors to attenuate anti-tumor immunity and escape destruction by the immune system, thereby facilitating tumor survival (PubMed: 12218188, PubMed: 27281199). The interaction with PDCD1/PD-1 inhibits cytotoxic T lymphocytes (CTLs) effector function (PubMed: 12218188). The blockage of the PDCD1-mediated pathway results in the reversal of the exhausted T-cell phenotype and the normalization of the anti-tumor response, providing a rationale for cancer immunotherapy (PubMed: 12218188)