Project description:Interaction of hematopoietic progenitors with the thymic stromal microenvironment induces them to proliferate, adopt the T cell fate, and asymmetrically diverge into multiple T lineages. Progenitors at various developmental stages are stratified among different regions of the thymus, implying that the corresponding microenvironments differ from one another, and provide unique sets of signals to progenitors migrating between them. The nature of these differences remains undefined. Here we use novel physical and computational approaches to characterize these stromal subregions, distinguishing gene expression in microdissected tissues from that of their lymphoid constituents. Using this approach, we comprehensively map gene expression in functionally distinct stromal microenvironments, and identify clusters of genes that define each region. Quite unexpectedly, we find that the central cortex lacks distinctive features of its own, and instead appears to function by sequestering unique microenvironments found at the cortical extremities, and modulating the relative proximity of progenitors moving between them. 4 to 6 weeks old male C57bl6/J were used for microdissection of 3 thymic cortical subregions and thymic medulla or for sorting cortical and medullary thymocytes. These samples were used for subsequent RNA purification, labeling and hybridization to Affymetrix arrays
Project description:Interaction of hematopoietic progenitors with the thymic stromal microenvironment induces them to proliferate, adopt the T cell fate, and asymmetrically diverge into multiple T lineages. Progenitors at various developmental stages are stratified among different regions of the thymus, implying that the corresponding microenvironments differ from one another, and provide unique sets of signals to progenitors migrating between them. The nature of these differences remains undefined. Here we use novel physical and computational approaches to characterize these stromal subregions, distinguishing gene expression in microdissected tissues from that of their lymphoid constituents. Using this approach, we comprehensively map gene expression in functionally distinct stromal microenvironments, and identify clusters of genes that define each region. Quite unexpectedly, we find that the central cortex lacks distinctive features of its own, and instead appears to function by sequestering unique microenvironments found at the cortical extremities, and modulating the relative proximity of progenitors moving between them.
Project description:Human T lymphogenesis includes emergence, migration and thymus-seeding of T lymphoid precursor, followed by T-lymphocytes commitment in thymus, which are largely unknown. Here, we perform single-cell RNA sequencing using cells isolated from human hemogenic/hematopoietic sites such as aorto-gonad-mesonephros (AGM), liver, and thymic primordia spanning embryonic and fetal stages. The transcriptional atlas of thymic primordia illustrates the cellular trajectory of early T-lymphocyte development. Further, thymic seeding progenitors in liver and unique T lymphoid progenitors in AGM at CS14, are first unveiled. We also reveal the stepwise-specification of thymic epithelial cells,and the potential cell-cell interactions between T-lymphocyte progenitors and stromal cells during thymus organogenesis. Our data provide new insights into T lymphogenesis, which prospectively directs the efficient regeneration of T- lymphocytes from pluripotent stem cells
Project description:B cell-interacting reticular cells (BRC) form transcriptionally and topologically stable immune-interacting microenvironments that direct efficient humoral immunity. While several immune niche factors have been elucidated, the cues sustaining BRC function and topology across activation states remain unclear. Here, we employed spatial transcriptome analysis of murine ingunal and mesenteric lymph nodes to examine co-localization of distinct BRC subsets and immune cells complementing BRC-immune cell interaction analysis. Spatial analysis supported predicted feedforward BRC-immune cell circuits that sustain topologically-organized, functional niches across inflammatory states, lymphoid organs and species.
Project description:Blood-stage malaria infection induces differentiation of several effector CD4 + T subsets including Tfh and Th1 cells. The cues and microarchitectural niches required in secondary lymphoid organs for their formation were previously uncharacterised. Here we used spatial transcriptomics to characterise the microarchitecture of mouse spleen before and during malaria infection, and mapping the spatial and molecular requirements of Tfh/Th1 differentiation.
Project description:Despite their key role in immunity our understanding of primary and secondary lymphoid stromal cell heterogeneity and ontogeny remains limited. Here, using genome-wide expression profiling and phenotypic and localization studies, we identify a functionally distinct subset of BP3-PDPN+PDGFRβ+/α+CD34+ stromal adventitial cells in both lymph nodes and thymus that is located within the perivascular niche surrounding PDPN-PDGFRβ+/α-Esam-1+ITGA7+ pericytes. In re-aggregate organ grafts adult CD34+ adventitial cells gave rise to multiple thymic and lymph node mesenchymal subsets including pericytes, FRC-, MRC- and FDC-like cells, the development of which was lymphoid environment dependent. During thymic ontogeny pericytes developed from a transient population of BP3-PDPN+PDGFRβ+/α+CD34-/lo anlage-seeding progenitors that subsequently up-regulated CD34 and we provide evidence suggesting that similar embryonic progenitors give rise to lymph node mesenchymal subsets. These findings extend the current understanding of lymphoid mesenchymal cell heterogeneity and highlight a role of the CD34+ vascular adventitia as a potential ubiquitous source of lymphoid stromal precursors in postnatal tissues. To comprehensively study the differences and similarities between mesenchymal stromal subsets in the thymus and lymph nodes, global gene expression analysis was performed on sorted PDPN-, BP-3-PDPN+ and BP-3+PDPN+ PDGFRb+ lymph node mesenchymal cells (LNMC) as well as PDPN- and BP-3-PDPN+ PDGFRb+ thymic mesenchymal cells (TMC) from 2 w old mice by microarray. Total RNA was prepared from TMC and LNMC (pooled inguinal, brachial and axillary LN) subsets sorted from 3 (TMC) and 10-11 (LNMC) 2 weeks old mice per experiment. Isolated RNA from 3 individual experiments was amplified and prepared for hybridization to the Affymetrix Mouse Gene 1.1 ST Array at a genomics core facility: Center of Excellence for Fluorescent Bioanalytics (KFB, University of Regensburg, Germany)
Project description:The thymic microenvironment is essential for proper differentiation and selection of thymocytes.Thymic involution in aged mice results in decreased T cell output and immune function. Here we use gene expression profiling of FACS sorted thymic stromal subsets to identify molecular mediators of thymocyte: stromal cell interactions, as well as gene expression changes thymic stromal subsets during early stages of thymic involution . We used microarrays to analyze gene expression differences between thymic stromal subsets from male C57BL/6J mice 1, 3, and 6 months of age.
Project description:Normal thymic T cell development is enabled by a stromal microenvironment most importantly composed of distinct epithelial cell populations in cortex and medulla. Their differentiation, growth and function require the expression of the transcription factor Foxn1. Direct targets of Foxn1 have, however, remained largely undefined. Utilizing newly created static and inducible genetic model systems, we now provide a genome wide map of Foxn1 target genes and the sequences bound by this master regulator. Foxn1 controls not only essential steps early in intrathymic lymphoid development including T cell lineage commitment but is also indispensable for later stages in T cell maturation such as the selection of CD4 and CD8 T cells. Thus, Foxn1 function critically choreographs both early and late events in thymic lympho-stromal cross-talk.
Project description:The thymic microenvironment is essential for proper differentiation and selection of thymocytes.Thymic involution in aged mice results in decreased T cell output and immune function. Here we use gene expression profiling of FACS sorted thymic stromal subsets to identify molecular mediators of thymocyte: stromal cell interactions, as well as gene expression changes thymic stromal subsets during early stages of thymic involution . We used microarrays to analyze gene expression differences between thymic stromal subsets from male C57BL/6J mice 1, 3, and 6 months of age. Thymic stromal subsets (cTEC, mTEClo, mTEChi, Sirpa-DC, Sirpa+DC, and fibroblasts) were isolated from two 1-, 3-, and 6- month old male C57BL/6J mice. After enzymatic digestion of the thymi, the stromal cells were FACS purified, and RNA was extracted, amplified, labeled and hybridized to Affymetrix mouse 430 2.0 arraysarrays. Raw data were uploaded to Gene Expression Commons for normalization. Both raw CEL and normalized datasets from the 36 samples are included. A model within Gene Expression Commons has been created for analyses/comparisons of these datasets, along with previously reported thymocyte subset datasets. The model within Gene Expression Commons thus contains 6 thymic stromal populations, each from mice 1, 3, and 6 months of age, with duplicates for each datset.
Project description:Multiple distinct cell types of the human lung and airways have been defined by single cell RNA sequencing (scRNAseq). Here we present a multi-omics spatial lung atlas to define novel cell types which we map back into the macro- and micro-anatomical tissue context to define functional tissue microenvironments. Firstly, we have generated single cell and nuclei RNA sequencing, VDJ-sequencing and Visium Spatial Transcriptomics data sets from 5 different locations of the human lung and airways. Secondly, we define additional cell types/states, as well as spatially map novel and known human airway cell types, such as adult lung chondrocytes, submucosal gland (SMG) duct cells, distinct pericyte and smooth muscle subtypes, immune-recruiting fibroblasts, peribronchial and perichondrial fibroblasts, peripheral nerve associated fibroblasts and Schwann cells. Finally, we define a survival niche for IgA-secreting plasma cells at the SMG, comprising the newly defined epithelial SMG-Duct cells, and B and T lineage immune cells. Using our transcriptomic data for cell-cell interaction analysis, we propose a signalling circuit that establishes and supports this niche. Overall, we provide a transcriptional and spatial lung atlas with multiple novel cell types that allows for the study of specific tissue microenvironments such as the newly defined gland-associated lymphoid niche (GALN).