Single cell RNAseq of immune cells from human palatine tonsils
Palatine tonsils are secondary lymphoid organs that are strategically positioned in the oropharynx to secure a first line of defense against oral pathogens. Specialized immune-interacting fibroblasts, generally termed fibroblastic reticular cells (FRC), underpin distinct microenvironments within lymphoid organs to compartmentalize and direct the efficient interaction and activation of immune cells. As a particular anatomical property, palatine tonsils harbor a reticular-shaped lymphoepithelium that generates an antigen sampling zone in the crypts. Here, we have employed single cell transcriptomics to unveil the molecular identity of tonsillar immune cells. We found that PI16+ RCs interact with activated macrophages via the OSM-OSMR pathway and thereby shape particular immune cell environments of inflamed lymphoid tissues.