The lack of mouse models permitting the specific ablation of tissue-resident macrophages and monocyte-derived cells complicates understanding of their contribution to tissue integrity and to immune responses. Here we use a new model permitting diphtheria-toxin (DT)-mediated depletion of those cells and in which dendritic cells are spared. We showed that the myeloid cells of the mouse ear skin dermis are dominated by a population of melanin-laden macrophages, called melanophages, that has been missed in most previous studies. By using gene expression profiling, DT-mediated ablation and parabiosis, we determined their identity including their similarity to other skin macrophages, their origin and their dynamics. Limited information exist on the identity of the skin cells responsible for long-term tattoo persistence. Benefiting of our knowledge on melanophages, we showed that they are responsible for retaining tattoo pigment particles through a dynamic process which characterization has direct implications for improving strategies aiming at removing tattoos.
Unveiling skin macrophage dynamics explains both tattoo persistence and strenuous removal.
Specimen part, Treatment
View SamplesThe aim of the dataset was to study on a genome-wide level the impact of Lat deficiency on gene expression in resting and activated CD4+ T cells
Quantitative proteomics analysis of signalosome dynamics in primary T cells identifies the surface receptor CD6 as a Lat adaptor-independent TCR signaling hub.
Specimen part
View SamplesPsoriasis is a chronic inflammatory skin disease of unknown etiology. Although macrophages and dendritic cells (DCs) have been proposed to drive the psoriatic cascade, their largely overlapping phenotype hampered studying their respective role. Topical application of Imiquimod, a Toll-like receptor 7 agonist, induces psoriasis in patients and psoriasiform inflammation in mice. We showed that daily application of Imiquimod for 14 days recapitulated both the initiation and the maintenance phase of psoriasis. Based on our ability to discriminate Langerhans cells (LCs), conventional DCs, monocytes, monocyte-derived DCs and macrophages in the skin, we characterized their dynamics during both phases of psoriasis. During the initiation phase, neutrophils infiltrated the epidermis whereas monocytes and monocyte-derived DCs were predominant in the dermis. During the maintenance phase, LCs and macrophage numbers increased in the epidermis and dermis, respectively. LC expansion resulted from local proliferation, a conclusion supported by transcriptional analysis. Continuous depletion of LCs during the course of Imiquimod treatment aggravated chronic psoriatic symptoms as documented by an increased influx of neutrophils and a stronger inflammation. Therefore, by developing a mouse model that mimics the human disease more accurately, we established that LCs play a negative regulatory role during the maintenance phase of psoriasis.
Dynamics and Transcriptomics of Skin Dendritic Cells and Macrophages in an Imiquimod-Induced, Biphasic Mouse Model of Psoriasis.
Specimen part, Treatment
View SamplesPlasmacytoid dendritic cells wre isolated from cutaneous lymph nodes of control C57BL/6 mice and used for microarray analysis.
Comparative genomics analysis of mononuclear phagocyte subsets confirms homology between lymphoid tissue-resident and dermal XCR1(+) DCs in mouse and human and distinguishes them from Langerhans cells.
Specimen part
View SamplesNumerous CD11b+ myeloid cells are present within the dermis. They are very heterogeneous and can be divided in dermal DCs, tissue monocytes and tissue macrophages. At steady state, only CD11b+ DC migrate from the dermis to the skin draining lymph nodes whereas upon DNFB-induced inflammation, CD11b+ DC as well as dermal monocytes migrated to the lymph nodes. The objective of this study was to use gene expression profiling to rigorously identify the different subsets of dermal CD11b+ myeloid cells at steady state and upon inflammation and to characterize their functional potential.
Origins and functional specialization of macrophages and of conventional and monocyte-derived dendritic cells in mouse skin.
Sex, Age, Specimen part
View SamplesDendritic cells (DC) are the most potent antigen-presenting cells of the immune system. In lymph nodes (LN), they are also believed to dispose of apoptotic cells, a critical function usually achieved by macrophages (M) in other tissues. We report a population of tolerogenic M located in the T cell zone of LN. T zone M (TZM) are long lived M seeded after birth and slowly replaced by blood monocytes. We show that TZM but not DC act as the only professional scavengers clearing apoptotic cells in the LN T cell zone. Importantly, we demonstrate that TZM prevent the capture of apoptotic cells by DC and the associated potential noxious activation of T cell immunity. We thus propose a new model in which efferocytosis and T cell activation are uncoupled processes handled by TZM and DC respectively.
T Cell Zone Resident Macrophages Silently Dispose of Apoptotic Cells in the Lymph Node.
Specimen part
View SamplesIntestinal macrophages rely on the constant replenishment by bone marrow derived Ly6Chigh monocytes in the adult organism. The developmental path from monocytes towards intestinal macrophages locally in the tissue is defined by the loss of Ly6C and acquisition of MHCII and CX3CR1 expression. We used microarray analysis to further characterise this local differentiation process.
Tissue-specific differentiation of colonic macrophages requires TGFβ receptor-mediated signaling.
Sex, Specimen part
View SamplesCD103+CD11b+ dendritic cells (DC) are unique to the intestine, but the factors governing their differentiation are unclear. Here we show that transforming growth factor receptor 1 (TGF beta 1) has an indispensable, cell intrinsic role in the development of these cells. Deletion of Tgfbr1 results in markedly fewer intestinal CD103+CD11b+ DCs and a reciprocal increase in the CD103CD11b+ DC subset. Transcriptional profiling identifies markers that define the CD103+CD11b+ DC lineage, including CD101, TREM1 and Siglec-F, and shows that the absence of CD103+CD11b+ DCs in CD11c-Cre.Tgfbr1fl/fl mice reflects defective differentiation from CD103CD11b+ intermediaries, rather than an isolated loss of CD103 expression. The defect in CD103+CD11b+ DCs is accompanied by reduced generation of antigen-specific, inducible FoxP3+ regulatory T (Treg) cells in vitro and in vivo, and by reduced numbers of endogenous TH17 cells in the intestinal mucosa. Thus, TGF beta 1 mediated signalling may explain the tissue-specific development of these unique DCs.
TGFβR signalling controls CD103<sup>+</sup>CD11b<sup>+</sup> dendritic cell development in the intestine.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reconstruction of gene regulatory networks reveals chromatin remodelers and key transcription factors in tumorigenesis.
Specimen part, Cell line
View SamplesThe mechanistic links between transcription factors and the epigenetic landscape, which coordinate the deregulation of gene networks during cell transformation are largely unknown. We used an isogenic model of stepwise tumorigenic transformation of human primary cells to monitor the progressive deregulation of gene networks upon immortalization and oncogene-induced transformation. By combining transcriptome and epigenome data for each step during transformation and by integrating transcription factor (TF) - target gene associations, we identified 142 Tfs and 24 chromatin remodelers/modifiers (CRMs), which are preferentially associated with specific co-expression paths that originate from deregulated gene programming during tumorigenesis. These Tfs are involved in the regulation of divers processes, including cell differentiation, immune response and establishment/modification of the epigenome. Unexpectedly, the analysis of chromatin state dynamics revealed patterns that distinguish groups of genes, which are not only co-regulated but also functionally related. Further decortication of TF targets enabled us to define potential key regulators of cell transformation, which are engaged in RNA metabolism and chromatin remodelling. Our study suggests a direct implication of CRMs in oncogene-induced tumorigenesis and identifies new CRMs involved in this process. This is the first comprehensive view of gene regulatory networks that are altered during the process of stepwise human cellular tumorigenesis in a virtually isogenic system.
Reconstruction of gene regulatory networks reveals chromatin remodelers and key transcription factors in tumorigenesis.
Specimen part, Cell line
View Samples