Project description:The lymph node is home to resident macrophage populations that are essential for healthy immune function and homeostasis. They are involved in multiple processes including the initiation of the local response to pathogens, halting viral and bacterial spread, and clearance of apoptotic cells, but the macrophage niche and factors that create it are largely undefined. Here we analyse fibroblastic reticular cells (FRCs) as an essential component of the lymph node macrophage niche using single-cell RNA-sequencing. Our analysis revealed that most reticular cell subsets within lymph nodes expressed master macrophage regulator CSF1. We further show that signalling through CSF1R was sufficient to support macrophage development, while in the presence of LPS, FRCs underwent a mechanistic switch and maintained support through CSF1R-independent mechanisms. Our data reveal a critically important role for FRCs in the creation of the parenchymal macrophage niche within LNs.
Project description:Secondary lymphoid organs are organized by fibroblastic reticular cells (FRCs), which direct immune cell positioning and support adaptive immunity. However, the mechanisms driving FRC subset differentiation remain unclear. To uncover signaling pathways involved in this process, we performed ATAC-seq on lymph node FRCs lacking Notch2. Our data reveal chromatin remodeling changes in the absence of Notch signaling.
Project description:Secondary lymphoid organs are structurally organized by fibroblastic reticular cells (FRCs), which support immune cell positioning and adaptive immune responses. However, the mechanisms driving the differentiation of FRCs into distinct functional subsets remain unclear. To investigate the role of Notch2 signaling in this process, we performed single-cell RNA sequencing (10x Genomics) on lymph node FRCs lacking Notch2 expression. Our dataset highlights how this pathway contributes to FRC differentiation.
Project description:Lymph node (LN) stromal cells, particularly fibroblastic reticular cells (FRCs), provide critical structural support and regulate immunity, tolerance and transport properties of LNs. In many tumors, LN metastasis is predictive of poor prognosis, however, stromal contribution to the evolving microenvironment of tumor draining LNs (TDLN) remains poorly understood. Here we present comparative transcriptional data of resting and TDLN FRCs after different time points of tumor drainage. FRCs were isolated from lymph nodes and FACS sorted based on the expression of CD45-, CD31- and PDPN+
Project description:Fibroblastic reticular cells (FRC) shape the organization of secondary lymphoid organs and actively promote the induction of immune responses by coordinating the interaction of innate and adaptive immune cells. However, the mechanisms underlying FRC functions during viral infections have remained largely unexplored. In the study, we combined FRC-specific genetic ablation of the type 1 IFN-alpha receptor (IFNAR) with high-dimensional transcriptomics analyses to elaborate the phenotypical alterations and functional consequences of impaired innate immunological sensing in FRC during lymph node-restricted viral infection
Project description:Acute GVHD is known to damage the structure of peripheral lymphoid organs. This study investigates how peripheral tolerance induction is affected by lymph node stroma damage in the context of graft-versus-host disease. Fibroblastic reticular cells (FRC) were flow sorted on day 7 post allo-BMT in mice developing acute GVHD, transplanted no GVHD-recipients or untransplanted control mice. The single miHA-mismatch female into male transplantation model was used (acute GVHD group: T-cell depleted bone marrow (TCDBM) + HY-specific TCR-transgenic MataHari CD8+ T cells into C57BL/6 male recipients; no GVHD group: TCDBM only).
