Single cell ATAC-seq study of Lung epithelial cells with Il33 KO cells

Epithelial cells are charged with protection at barrier sites, but whether this normally beneficial response might sometimes become dysfunctional still needs definition. Here we identify a pattern of imbalance marked by basal epithelial cell growth and differentiation that replaces normal airspaces in a mouse model of progressive post-viral lung disease due to Sendai virus. Single-cell and lineage-tracing technologies identify a distinct subset of basal epithelial stem cells (basal- ESCs) that extend into gas-exchange tissue to form long-term bronchiolar-alveolar remodeling regions. Moreover, this cell subset is selectively expanded by crossing a cell growth and survival checkpoint linked to the nuclear-localized alarmin IL-33 that is independent of IL-33-receptor signaling and instead connected to autocrine chromatin accessibility. This mechanism creates an activated stem-progenitor cell lineage with potential for physiological or pathological function. Thus, conditional loss of Il33 gene function in basal epithelial cells disrupts homeostasis of the epithelial barrier at skin and gut sites but also markedly attenuates post-viral disease in the lung based on down-regulation of remodeling and inflammation. We thereby identify a basal-ESC strategy to deploy innate-immune machinery that appears to overshoot the primordial goal of self- defense. The findings reveal new targets to stratify and correct chronic and often deadly post-viral disease. Overall design: This dataset consists of 2 10x Genomics scATAC-seq libraries, including WT sample and Il33KO sample.