ABSTRACT
PD-L1 (programmed cell death 1 ligand 1 ) is an immunosuppressive ligand which mainly expressed on tumor cells, inhibiting the activation of T lymphocytes through binding with PD-1 (programmed cell death protein 1), thus leading to immune escape.PD-1/PD-L1 immune checkpoint blockade therapy, which established based on the above mechanism, gained success in the clinical treatment of solid tumors.Various kinds of PD-L1 posttranslational modifications were identified following the in-depth studies of PD-L1, including glycosylation, phosphorylation, ubiquitination, palmitoylation, et al.Meanwhile, multiple studies indicated that posttranslational modifications governs PD-LI-mediated immune escape through regulating the protein stability and physiological functions of PD-L1, which makes posttranslational modifications of PD-L1 turns into a new "entry" point of PD-L1 studies.Drugs targeting posttranslational modifications of PD-L1 exhibited favorable applicational prospects in immunotherapy at the same time.Regulating PD-L1-mediated immune escape through intervening PD-L1 posttranslational modifications becomes a new strategy for improving the efficacy of immunotherapy.In this review, we summarized the posttranslational modifications of PD-L1 and its applicational prospects in immunotherapy, hoping to provide theoretical supports for future studies focused on PD-L1.