Characterization of Murine Intestinal Mesenchymal Stromal Cells

The intestinal mucosa contains numerous and diverse subsets of immune cells that play an essential role in tissue homeostasis, immunity, and inflammation. Immune cells are diffusely distributed throughout the intestinal lamina propria (LP) within a network of mesenchymal stromal cells (MSCs) that are increasingly recognized as regulators of epithelial as well as immune cell development and function^1,2. Despite this, our understanding of intestinal LP MSC ontogeny, heterogeneity, and function remains limited. To gain a better understanding of LP MSC heterogeneity, murine small intestinal and colon LP cell suspensions (after removal of the smooth muscle layer) were stained and flow cytometry sorted, removing epithelial (EPCAM+), endothelial (CD31+), lymphoid tissue associated (BP3+), hematopoietic (CD45+, Ter119+) and glial cells (NCAM^hi). Single cell RNA-seq on sorted cells was subsequently performed by DROPseq. Our preliminary results suggest that the LP MSC compartment comprises numerous specialized subsets, a result we are currently confirming by flow cytometry and whole mount immunohistochemical analysis. Future studies aim to assess the ontogeny of these subsets and the potential role of each subset in intestinal immune homeostasis and disease.