Flash Talk & Poster Presentation 18th International Symposium on Dendritic Cells 2026

RORγt+ Dendritic Cells are a distinct lymphoid-derived lineage (#108)

Patrick Fernandes Rodrigues 1 2 , Shitong Wu 2 , Tihana Trsan 2 , Bishan Bhattarai 2 , Santosh K. Panda 2 , Jose Luis Facchi 2 , Marina Cella 2 3 , Marco Colonna 2 3
  1. Institute of experimental immunology UZH, Zürich, ZüRICH, Switzerland
  2. Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
  3. Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA

The induction of immune tolerance to dietary antigens and commensal microbiota relies on peripherally induced RORγt+ regulatory T cells (pTregs). While specialized RORγt+ antigen-presenting cells (APCs) have been implicated in this process, the developmental origin and specification of tolerogenic APCs that drive pTreg induction remain poorly defined. Here, we identify RORγt+ dendritic cells (DCs) as a distinct lymphoid-derived lineage whose development is essential for intestinal immune homeostasis. Using lineage tracing, single-cell transcriptomics, and in vitro and in vivo differentiation assays, we delineate a developmental trajectory originating from bone marrow resident Rorc(t)+ progenitors. These include a RORγt+ innate lymphoid progenitor (RILP), which generates both type 3 innate lymphoid cells (ILC3s) and RORγt+ DCs, and a pre-RORγt+ DC precursor committed exclusively to the RORγt+ DC lineage. Differentiation assays demonstrate that RORγt+ DCs arise predominantly from IL-7R+ lymphoid progenitors, which efficiently generate this lineage in culture and upon adoptive transfer, whereas myeloid progenitors show minimal potential. These findings establish RORγt+ DCs within the lymphoid branch of hematopoiesis. We further show that RORγt+ DC development is controlled by a defined transcriptional and epigenetic program. A cis-regulatory enhancer located +7kb downstream of the Rorc locus is required for the generation of both RILPs and pre-RORγt+ DCs, while its accessibility is regulated by the repressors REV-ERBα and REV-ERBβ. Downstream, the transcription factors PRDM16 and PU.1 enforce lineage commitment and enable progression into mature RORγt+ DC subsets. Disruption of this developmental program selectively abrogates RORγt+ DC differentiation, resulting in reduced pTreg induction and skewing toward T helper 2 responses. In contrast, selective loss of ILC3s does not recapitulate these defects, identifying RORγt+ DCs as the critical tolerogenic APC lineage. Together, these findings define an enhancer-driven developmental pathway linking lymphoid lineage specification to immune tolerance, positioning RORγt+ DCs as specialized regulators of intestinal homeostasis.