Epithelial endoplasmic reticulum stress orchestrates a protective IgA response II

Immunoglobulin A (IgA) is the major secretory immunoglobulin isotype at mucosal surfaces where it regulates microbial commensalism and excludes luminal factors from contacting intestinal epithelial cells (IEC). IEC endoplasmic reticulum (ER) stress induces a polyreactive IgA response which protects from small intestinal inflammation. IEC ER stress causes expansion and activation of peritoneal B1b cells independent of microbiota and T cells that culminates in increased lamina propria and luminal IgA. Xbp1dIEC mice exhibit IEC ER stress by conditional deletion of X-box-binding protein 1 (XBP1). Here we examine single-cell transcriptomes of peritoneal cavity cells of germ-free Xbp1dIEC mice (KO) compared to littermate controls (WT). Single-cell gene expression profiles of peritoneal cavity cells of 10-week-old germ-free Xbp1dIEC and WT mice were generated using a droplet-based system (10X Genomics Chromium).