Fig. 1: Immune checkpoint activation in SNCs.

Stressed or damaged cells in a senescent state remain cell cycle arrested and produce a secretome enriched in immune modulatory factors that attract immune cells, including cytotoxic T cells that kill their target. Some SNCs escape clearance by inducing the checkpoint protein PD-L1, an event that involves autocrine SASP signaling, E2F transcriptional activity, and impaired proteasome activity. This rescue mechanism can be overcome by the administration of immune checkpoint inhibitors.