Project description:Fibroblastic reticular cells (FRCs) are heterogeneous. We use single cell RNA sequencing to identify subsets of FRCs in fat-associated lymphoid clusters (FALC) in the mesenteric adipose tissue
Project description:Fibroblastic reticular cells (FRCs) (CD45- Ter119-MADCAM1- CD21/35- CD31- PDPN-) from skin draining lymph nodes of Grem1-Cre-ERT2.cki; Rosa26-LSL-EYFP mice were sorted and subjected to bulk RNA-seq of Grem1 reporter + and Grem1 reporter - cells.
Project description:Lymph nodes (LNs) are essential hubs for the induction and regulation of immune responses. Immune activation, either systemic or local, is accompanied by the lymph node swelling response, which results in up to threefold expansion in volume. Increased immigration of immune cells via the blood vasculature causes the LN swelling response with retention of lymphocytes and myeloid cells in perivascular niches. The perivascular niche is supported by fibroblastic cells known as mural cells (vascular smooth muscle cells (VSMCs) and pericytes) and by perivascular reticular cells (PRCs) that connect the perivascular niche to the fibroblastic reticular cell (FRC) network. Here, we used high-resolution confocal microscopy, flow cytometry, single cell transcriptomics and cell fate mapping in mouse models to delineate VSMC and PRC phenotypes and differentiation during development in different LN entities.
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:Splenic white pulp (WP) structures are underpinned by fibroblastic stromal cells (FSCs) to facilitate splenic compartmentalization and execute efficient immune responses. Although distinct WP FSCs exhibit various molecular traits, the origin and the hierarchical differentiation of different cell subsets are not characterized. Here we showed, the organization of splenic WP and the differentiation of WP FSCs were governed by lymphotoxin beta receptor (LTβR) signaling pathway. Cell fate mapping analysis revealed that different WP fibroblastic stromal cells descend from a common perivascular LTβR-sensitive mesenchymal lymphoid organizer cells (mLTo) at prenatal stage. Moreover, embryonic mLTo cells required LTβR signaling to give rise to different WP stromal cell subsets, while the proliferation of these cells was devoid of LTβR signaling but followed the development of WP during ontogeny. Moreover, cell fate mapping from different time point indicated a consecutive commitment of mLTo cells initiated from the proximal region around the splenic artery. RNAseq and differentiation trajectory analysis of distinct FSCs showed that Ltbr-deficient cells and perivascular reticular cells (PRCs) from adult spleen exhibited a progenitor phenotype and revealed a closer hierarchical lineage with embryonic mLTo cells. Taken together, our results unveil that embryonic mLTo cells residing in the perivascular niches can give rise to different FSC populations in a LTβR-dependent manner during development.
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