Fig. 6.

Proposed mechanism of antitumor effects of PLMDs plus RT. Schematic illustration shows tumor before (A) and after reoxygenation (B), reducing acidosis and ROS by PLMDs [30] resulting in PD-L1 down-regulation (B). PLMDs plus RT activated autophagy, ER stress, and enhanced DNA damage (C), inducing the release of DAMPs (D). In addition, remodeling of the immune tumor microenvironment using PLMDs plus RT reduced MDSCs and Tregs (E) while increasing the conversion of M2 to M1 macrophages (E) and increased infiltration of CTL in tumors (E), leading to apoptosis (F). PD-1, programmed death-1.