PD-L1 methylation restricts PD-L1/PD-1 interactions to control cancer immune surveillance
Changsheng Huang, Shengxiang Ren, Yaqi Chen, Anyi Liu, Qi Wu, Tao Jiang, Panjing Lv, Da Song, Fuqing Hu, Jingqing Lan, Li Sun, Xue Zheng, Xuelai Luo, Qian Chu, Keyi Jia, Yan Li, Jun Wang, Caicun Zou, Junbo Hu, Guihua Wang
Abstract
Immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) or programmed cell death 1 ligand 1 (PD-L1) have enabled some patients with cancer to experience durable, complete treatment responses; however, reliable anti-PD-(L)1 treatment response biomarkers are lacking. Our research found that PD-L1 K162 was methylated by SETD7 and demethylated by LSD2. Furthermore, PD-L1 K162 methylation controlled the PD-1/PD-L1 interaction and obviously enhanced the suppression of T cell activity controlling cancer immune surveillance. We demonstrated that PD-L1 hypermethylation was the key mechanism for anti-PD-L1 therapy resistance, investigated that PD-L1 K162 methylation was a negative predictive marker for anti-PD-1 treatment in patients with non-small cell lung cancer, and showed that the PD-L1 K162 methylation:PD-L1 ratio was a more accurate biomarker for predicting anti-PD-(L)1 therapy sensitivity. These findings provide insights into the regulation of the PD-1/PD-L1 pathway, identify a modification of this critical immune checkpoint, and highlight a predictive biomarker of the response to PD-1/PD-L1 blockade therapy.