The difference between intraepithelial mast cells and lamina propria mast cells (ATAC-seq)

Type 2 immune responses are crucial for protection against helminth infections and for the maintenance of tissue homeostasis, yet the underlying mechanisms of immune activation remain incompletely understood. Here, we study the role of mast cells in type 2 immunity. While the number of lamina propria residing mast cells (termed LPMCs hereinafter) remained stable, intraepithelial mast cells (termed IEMCs hereinafter) markedly expanded during the course of type 2 responses. We uncovered a new type 2 response mechanism depending on the crosstalk between mast cells and epithelial cells, and defined the function of intraepithelial mast cells. H. polygyrus larvae were used to infect WT mice. After 14 days, IEMCs and LPMCs were sorted from infected intestinal epithelium and LP, respectively.