PD-1 aborts the activation trajectory of autoreactive CD8 T cells to prohibit their acquisition of effector functions.

Anti-PD-1 therapy can induce eradication of tumors and immune-related adverse events (irAEs) in humans and model animals. However, how anti-PD-1 therapy modifies cellular phenotypes of CD8 T cells to destroy tumors and damage self-tissues remains to be clarified. Here we performed single cell mRNA expression profiling of autoreactive CD8 T cells under or beyond PD-1 suppression in target tissues and reconstructed their activation trajectory.