Cell-intrinsic PD-L1 signaling drives immunosuppression by myeloid-derived suppressor cells through IL-6/Jak/Stat3 in PD-L1-high lung cancer

Background Some patients with non-small-cell lung cancer (NSCLC) benefit from immune checkpoint inhibitors (ICIs) despite programmed death-ligand 1 (PD-L1) expression. To address the mechanism of ICI resistance in PD-L1-positive NSCLC, we investigated the role of tumor-cell-intrinsic function of PD-L1 in interleukin (IL)-6-mediated immunosuppression. Methods Cohorts of NSCLC patients treated with ICI and public datasets were analyzed. PD-L1-overexpressing and PD-L1-knockdown NSCLC cells were submitted to RNA-seq, in vitro analyses, chromatin immunoprecipitation-qPCR, CUT&Tag, and biochemical assays. Human myeloid-derived suppressor cells (MDSCs) sorted from peripheral blood mononuclear cells were…