Project description:The ontogeny of human Langerhans cells (LCs) remains poorly characterized, in particular the nature of LC precursors and the factors that may drive LC differentiation. Through a systematic transcriptomic analysis of TSLP-activated dendritic cells (DCs), we unexpectedly identified markers that have been associated with a skin-homing potential as well as with a LC phenotype. We performed transcriptomic analysis of TSLP-activated blood DCs, as compared to freshly purified, Medium-, and TNF-activated DCs. Among TSLP up-regulated genes, we identified molecules associated with skin homing, LC phenotype, and LC function, as determined by a literature-based survey. Conversely, genes not expressed in LCs were not found among TSLP-induced genes. Further experiments showed that TGF-? synergized with TSLP leading to the differentiation of blood BDCA-1+ DCs into bona fide Birbeck granule-positive LCs. The ontogeny of human Langerhans cells (LCs) remains poorly characterized, in particular the nature of LC precursors and the factors that may drive LC differentiation. Through a systematic transcriptomic analysis of TSLP-activated dendritic cells (DCs), we unexpectedly identified markers that have been associated with a skin-homing potential as well as with a LC phenotype. We performed transcriptomic analysis of TSLP-activated blood DCs, as compared to freshly purified, Medium-, and TNF-activated DCs. Among TSLP up-regulated genes, we identified molecules associated with skin homing, LC phenotype, and LC function, as determined by a literature-based survey. Conversely, genes not expressed in LCs were not found among TSLP-induced genes. Further experiments showed that TGF-? synergized with TSLP leading to the differentiation of blood BDCA-1+ DCs into bona fide Birbeck granule-positive LCs. Dendritic cells (DC) were purified from the blood of healthy human donors. Each replicate comes from a different donor. There are 6 freshly purified samples (Control_0h), 4 DC samples cultured during 6h with no additional stimulus than the medium (Control_6h), 5 samples cultured during 6h with recombinant TSLP (Thymic Stromal Lymphopoietin at 20 ng/uL) (TSLP_6h) and 3 samples cultured during 6h with recombinant TNF (Tumor necrosis factor at 20 ng/mL) (TNF_6h).
Project description:The ontogeny of human Langerhans cells (LCs) remains poorly characterized, in particular the nature of LC precursors and the factors that may drive LC differentiation. Through a systematic transcriptomic analysis of TSLP-activated dendritic cells (DCs), we unexpectedly identified markers that have been associated with a skin-homing potential as well as with a LC phenotype. We performed transcriptomic analysis of TSLP-activated blood DCs, as compared to freshly purified, Medium-, and TNF-activated DCs. Among TSLP up-regulated genes, we identified molecules associated with skin homing, LC phenotype, and LC function, as determined by a literature-based survey. Conversely, genes not expressed in LCs were not found among TSLP-induced genes. Further experiments showed that TGF-β synergized with TSLP leading to the differentiation of blood BDCA-1+ DCs into bona fide Birbeck granule-positive LCs. The ontogeny of human Langerhans cells (LCs) remains poorly characterized, in particular the nature of LC precursors and the factors that may drive LC differentiation. Through a systematic transcriptomic analysis of TSLP-activated dendritic cells (DCs), we unexpectedly identified markers that have been associated with a skin-homing potential as well as with a LC phenotype. We performed transcriptomic analysis of TSLP-activated blood DCs, as compared to freshly purified, Medium-, and TNF-activated DCs. Among TSLP up-regulated genes, we identified molecules associated with skin homing, LC phenotype, and LC function, as determined by a literature-based survey. Conversely, genes not expressed in LCs were not found among TSLP-induced genes. Further experiments showed that TGF-β synergized with TSLP leading to the differentiation of blood BDCA-1+ DCs into bona fide Birbeck granule-positive LCs.
Project description:Langerhans cells (LCs) are antigen presenting cells residing in the epidermis. Due to the difficulties with obtaining sufficient quantities of LCs for functional studies, many controversies exist about their origin and function. To gain insights into the molecular mechanisms underpinning LC biology and to elucidate how similar they are to a classical tissue resident DCs of myeloid origin, we undertook a whole transcriptome analysis of human skin migratory CD1a+ LCs and CD11c+ DDCs, stimulated with an epidermal pro-inflammatory cytokine, TNF-α and TSLP over a time course of 24h. RNA was extracted from 250,000 human skin migratory CD1a+ LCs and CD11c+ DDCs stimulated in culture with 25ng/ml of TNF-α or 15ng/ml TSLP for 0, 2, 8 and 24h. RNA concentration and integrity was determined with an Agilent Bioanalyser (RIN of 7.0 or above) and gene expression analysis was carried out using the Human Genome U-219 Affymetrix platform by ARK-Genomics Centre, The Roslin Institute, Edinburgh. Expression data were normalised using the Robust Multichip Average (RMA) package. 2,334 transcripts regulated by exposure of skin DCs to TNF-α were identified with Bayesian Estimation of Temporal Regulation, a cut-off threshold 0.05 , for genes showing ≥ 1.5 fold difference between the maximum gene expression level and time 0 control in log2(x) RMA normalised gene expression. The interactive 3D diagram presenting the transcriptomic networks in human skin DCs can be viewed at: http://www.macrophages.com/LC_vs_DC. The model of IRF-GRN can be vieved at : http://www.virtuallyimmune.org/irf-grn/
Project description:Langerhans cells (LCs) are antigen presenting cells residing in the epidermis. Due to the difficulties with obtaining sufficient quantities of LCs for functional studies, many controversies exist about their origin and function. To gain insights into the molecular mechanisms underpinning LC biology and to elucidate how similar they are to a classical tissue resident DCs of myeloid origin, we undertook a whole transcriptome analysis of human skin migratory CD1a+ LCs and CD11c+ DDCs, stimulated with an epidermal pro-inflammatory cytokine, TNF-α over a time course of 24h. RNA was extracted from 250,000 human skin migratory CD1a+ LCs and CD11c+ DDCs stimulated in culture with 25ng/ml of TNF-α for 0, 2, 8 and 24h. RNA concentration and integrity was determined with an Agilent Bioanalyser (RIN of 7.0 or above) and gene expression analysis was carried out using the Human Genome U-219 Affymetrix platform by ARK-Genomics Centre, The Roslin Institute, Edinburgh. Expression data were normalised using the Robust Multichip Average (RMA) package. 2,334 transcripts regulated by exposure of skin DCs to TNF-α were identified with Bayesian Estimation of Temporal Regulation, a cut-off threshold 0.05 , for genes showing ≥ 1.5 fold difference between the maximum gene expression level and time 0 control in log2(x) RMA normalised gene expression. The interactive 3D diagram presenting the transcriptomic networks in human skin DCs can be viewed at: http://www.macrophages.com/LC_vs_DC RNA was extracted from 250,000 human skin migratory CD1a+ LCs and DDCs stimulated in culture with 25ng/ml of TNF-α for 0, 2, 8 and 24h. RNA concentration and integrity was determined with an Agilent Bioanalyser (RIN of 7.0 or above) and gene expression analysis was carried out using the Human Genome U-219 Affymetrix platform by ARK-Genomics Centre, The Roslin Institute, Edinburgh. Expression data were normalised using the Robust Multichip Average (RMA) package. 2,334 transcripts regulated by exposure of skin DCs to TNF-α were identified with Bayesian Estimation of Temporal Regulation, a cut-off threshold 0.05 , for genes showing ≥ 1.5 fold difference between the maximum gene expression level and time 0 control in log2(x) RMA normalised gene expression. *submitter cannot locate the CEL files
Project description:Tissue-resident macrophages (TRMs) are critical for tissue homeostasis/repair. We previously showed that dermal TRMs produce CCL24 which mediates their interaction with IL-4 producing eosinophils, required to maintain their M2-like properties in the TH1 environment of the Leishmania major infected skin. Here, we unveil another layer of TRM self-maintenance involving production of TSLP, an alarmin typically characterized as epithelial cell-derived. Both TSLP signaling and IL-5+ innate lymphoid cell 2 (ILC2s) were shown to maintain dermal TRM numbers and promote infection. Single cell RNA sequencing identified the dermal TRMs as the sole source of TSLP and CCL24. Generation of Ccl24-cre mice permitted specific labeling of dermal TRMs, as well as interstitial TRMs from other organs. Genetic ablation of TSLP from dermal TRMs reduced the number of dermal TRMs and ameliorated infection. Here, we show that by orchestrating localized type 2 circuitries with ILC2s and eosinophils, dermal TRMs are self-maintained as a replicative niche for L. major.
Project description:Langerhans cells (LCs) in the epidermis promote immune homeostasis, efficiently activating tolerogenic and immunogenic T cell responses. To understand genomic programming in human Langerhans cells we performed whole transcriptome (bulk RNA-seq and single cell RNA-seq) profiling and analysis of H3K4Me3 and H3K27Ac histone modifications across LC genome in primary human cells from 6 independent donors. Primary LCs were either unstimulated and stimulated with TNF-alpha. Additionally we performed a CRISPR editing experiment for IRF4
Project description:Langerhans cell histiocytosis (LCH) is a disease characterized by the accumulation of eponymous CD1a+ Langerin+ Langerhans-cell (LC)-like dendritic cells (DC) of largely unknown origin. Here we have performed comparative transcriptome analysis of highly purified CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations and disease courses and three major human dendritic cell lineages: epidermal Langerhans cells, myeloid dendritic cells (mDC1) and plasmacytoid dendritic cells (pDC) in order to investigate the relationship between LCH cells and naturally occurring dendritic cells. Data obtained indicate that LCH cells form a distinct DC entity. Furthermore, we have identified transcripts that are uniquely expressed by LCH cells in comparison to LC, mDC1, and pDC, and induce LCH-specific features in human DC. Primary cells were isolated from peripheral blood (mDC1 and pDC), skin (epidermal Langerhans cells) and CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations. RNA was isolated from these cells ex vivo.
Project description:The exit of antigen-presenting cells (APC) and lymphocytes from inflamed skin to afferent lymph is vital for the initiation and maintenance of dermal immune responses. How such exit is achieved and how cells transmigrate the distinct endothelium of lymphatic vessels is however unknown. Here we show that inflammatory cytokines trigger activation of dermal lymphatic endothelial cells (LEC) leading to expression of the key leukocyte adhesion receptors ICAM-1, VCAM-1 and E-selectin, as well as a discrete panel of chemokines and other potential regulators of leukocyte transmigration. Furthermore, we show that both ICAM-1 and VCAM-1 are induced in the dermal lymphatic vessels of mice exposed to skin contact hypersensitivity where they mediate lymph node trafficking of DC via afferent lymphatics. Lastly, we show that TNF_-stimulates both DC adhesion and transmigration of dermal LEC monolayers in vitro and that the process is efficiently inhibited by ICAM-1 and VCAM-1 adhesion-blocking mAbs. These results reveal a CAM-mediated mechanism for recruiting leukocytes to the lymph nodes in inflammation and highlight the process of lymphatic transmigration as a potential new target for anti-inflammatory therapy. Experiment Overall Design: Global gene expression profile of normal dermal lymphatic endothelial cells cultured in media alone (no TNF) compared to that of normal dermal lymphatic endothelial cells stimulated with TNFalpha, 1 ng/ml for 48h.Triplicate biological samples were analyzed from human lymphatic endothelial cells (3 x controls; 3 x TNF treated) and a single sample analyzed from mouse lymphatic endothelial cells (1 x controls; 1 x TNF treated).
Project description:Langerhans cells (LC) coordinate immune homeostasis at the human epidermis, proficent in initiating immunogenic and tolerogenic immune responses. To investigate the transcriptomic mediators of human LC immunogenic vs tolerogenic immune responses, we performed single cell RNA-sequencing of migratory LCs extracted from epidermal sheets stimulated with or without TNF.
Project description:Transcriptomic profiling of sheep skin lymph DC subsets after 16h in vitro culture in medium or stimulated by non replicative Canine Adenovirus serotype 2 Reference design: total enriched lymph dendritic cells- Biological replicates: 4 sheep (70958, 50274, 30066, 11261)- Samples: FACS sorted CD103 -type and CD11b type cultured in medium or with CAV2