Il7rKO Single Cell

The immune system must distinguish pathogens from innocuous dietary antigens, but the precise mechanisms and cellular actors involved are unclear. Here, we demonstrate that RORγt-lineage antigen-presenting cells (APCs) expressing the Autoimmune Regulator (Aire) gene – referred to as RORγt eTACs – are required for oral tolerance. Using lineage tracing and single-cell sequencing, we show that RORγt eTACs are of a myeloid-derived lineage and establish consensus identities for all RORγt-lineage APCs. We found that RORγt eTACs, but not type 3 innate lymphoid cells, are necessary and sufficient for oral tolerance induction. Upon depletion of RORγt eTACs, mice fail to develop food-specific Tregs and display severe delayed-type hypersensitivity responses. These findings establish RORγt eTACs as critical mediators of oral tolerance and suggest novel targets to modulate immune tolerance. We obtained lymph nodes (mesenteric,cervical, inguinal, axillary, brachial, and para-aortic) from WT and IL7rKO mice and FACS-sorted tdTmt+ MHCII+ cells for subsequent scRNA-seq.