T cells and monocyte-derived myeloid cells mediate immunotherapy-related hepatitis in a mouse model

•Pdcd1-/- mouse can be utilized as a model for immune checkpoint inhibitor-mediated liver injury.•Single-cell immune transcriptional profiling revealed a landscape of molecular pathways responding to inhibition of PD1, CTLA4 and IDO1.•We identified a subset-specific T cell activation signature and common IFNγ signature.•Monocyte-derived macrophages coordinate the T cell response to immune checkpoint inhibitors.