8.A.23.5.1
Programmed cell death 1 ligand 1, PDL1, CD274, B7H1, PDCD1L1, or PDCD1LG1, of 290 aas and 2 TMSs, one N-terminal and one C-terminal. It plays a role in induction of immune tolerance to self. It plays a critical role in induction and maintenance of immune tolerance to self (Freeman et al. 2000, Burr et al. 2017, Mezzadra et al. 2017). As a ligand for the inhibitory receptor PDCD1/PD-1, it modulates the activation threshold of T-cells and limits T-cell effector responses. Several forms of PD-L1 exist expressed on the plasma membrane (mPD-L1), at the surface of secreted cellular exosomes (exoPD-L1), in cell nuclei (nPD-L1), or as a circulating, soluble protein (sPD-L1) (Bailly et al. 2021). The membrane, exosomal and soluble forms of PD-L1 are parts of the highly dynamic PD-1/PD-L1 signaling pathway. PD-L1 translocation to the plasma membrane enables tumor immune evasion through MIB2 ubiquitination (Yu et al. 2023).