scRNAseq of healthy and irradiated mouse parotid glands highlights crosstalk between immune and secretory cells during chronic injury

Translational frameworks to understand the chronic loss of salivary dysfunction that follows after clinical irradiation, and the development of regenerative therapies remain an unmet need. Advances in single cell (sc)RNAseq has made it possible to identify previously uncharacterized cell types within tissues and to uncover gene regulatory networks that mediate cell-cell communication and drive specific cell states. scRNAseq studies have been performed for virtually all major tissues including salivary glands; however, there are currently no scRNAseq studies on chronically irradiated salivary glands. Here, we present scRNAseq from control and irradiated parotid glands from mouse collected 10 months post-irradiation. We identify a previously uncharacterized population of epithelial cells in the gland defined by expression of Etv1, which could be a possible salivary precursor. Furthermore, our data suggests that CD8+ T-cells and secretory cells are the most transcriptionally affected during chronic injury with radiation, suggesting active immune involvement during chronic irradiation injury. Notably, scRNAseq of in vivo models of chronic IR injury has only been performed in liver, lung, and skin, and data is only publicly available for lung and skin. Thus, our study will also be an essential resource to better understand cell-specific responses to chronic irradiation in general. Overall design: irradiated and control parotig glands drom C3H mice were dissociated and analyzed by scRNAseq 10-months post-irradiation. SEURAT workflow for scRNAseq analysis was followed by differential expression between control and irradiated.