Innate sensor Dhx9 orchestrates TCR signaling and controls CD8 T cell immunity against viral infection [ATAC-Seq]

Nuclear sensor molecules of innate cells recognize pathogenic DNA or RNA to activate innate immunity and defense against bacteria and virus infection. Although some sensors exhibit their preliminary functions in T cells, it is still unclear about the underlying mechanism. Here we found a nuclear sensor-Dhx9, was enhanced its expression in effector CD8 T cells. T cell specific deletion of Dhx9 caused an impaired CD8 T cell expansion, memory formation and virus clearance. Mechanically, Dhx9 could directly regulate id2 transcription and in turn control effector CD8 T cell differentiation. Importantly, Dhx9 could bind to Lck protein, mediate Zap70 phosphorylation, and promoting TCR downstream signaling - ERK pathway to protect effector CD8 T cells from apoptosis. The DSRM and DEXDc-Helicase domain is required for Lck binding and Id2 transcription, respectively. Therefore, we revealed a novel regulatory mechanism that innate nuclear sensor regulates T cell fate and function through modulating adaptive pathways. Examination of wt and Dhx9 deficient CD8 T cells from the spleens 8 days post infection