Tristetraprolin (TTP, encoded by Zfp36) regulates the mRNA stability of several important cytokines. Due to the critical role of this RNA-binding protein in the control of inflammation, TTP deficiency leads to the spontaneous development of a complex inflammatory syndrome. So far, this phenotype has been largely attributed to dysregulated production of TNF and IL-23 by myeloid cells such as macrophages or dendritic cells. Here, we generated mice with conditional deletion of TTP in keratinocytes. These mice developed exacerbated inflammation in the imiquimod-induced psoriasis model. Furthermore, these mice progressively developed a spontaneous pathology with systemic inflammation, psoriatic-like skin lesions and dactylitis. Finally, we provide evidence that keratinocyte-derived TNF productin drives the different pathological features. In summary, these findings expand current views on the initiation of psoriasis and related arthritis by revealing the keratinocyte-intrinsic role of TTP.
Tristetraprolin expression by keratinocytes controls local and systemic inflammation.
Specimen part, Treatment
View SamplesThe goal of this study was to identify the transcriptional mechanisms involved in the activation of the immune system by QS-21, a triterpene glycoside purified from the bark of Quillaja saponaria which has adjuvant activity in vivo. Saponins represent a promising class of vaccine adjuvant. Together with the TLR4-ligand MPL, QS-21 is part of the Adjuvant System AS01, a key component of the Malaria and Zoster candidate vaccines that display demonstrated clinical efficacy. However, the mechanism of action of QS-21 in this liposomal formulation is poorly understood. Upon intra-muscular immunisation, we observed that QS-21 rapidly accumulated in CD169+ resident macrophages of the draining lymph node where it elicited a local innate immune response. Depletion of these cells abrogated QS-21-mediated innate cell recruitment to the lymph node, dendritic cell (DC) phenotypic maturation as well as the adjuvant effect on T cell and antibody responses to co-administered antigens. DCs rather than lymph node-resident macrophages were directly involved in T cell priming by QS-21 as revealed by the decrease in antigen-specific T cell response in Batf3/ mice. Further analysis showed that the adjuvant effect of QS-21 depended on the integration of Caspase-1 and MyD88 pathways, at least in part through the local release of HMGB1. Taken together, this work unravels the key role of lymph node sentinel macrophage in controlling the adjuvant effect of a molecule proven to improve vaccine response in humans
Central Role of CD169<sup>+</sup> Lymph Node Resident Macrophages in the Adjuvanticity of the QS-21 Component of AS01.
Specimen part
View SamplesWe derived gene set signature for GSEA investigation study from primary cell culture derived from healthy patients. Cells were exposed or not to cytokine for 24H before RNA collection and microarray analysis
Selective inhibition of TGF-β1 produced by GARP-expressing Tregs overcomes resistance to PD-1/PD-L1 blockade in cancer.
Specimen part, Treatment
View SamplesWhile blood transcriptional profiling has improved diagnosis and understanding of disease pathogenesis of adult tuberculosis (TB), no studies applying gene expression profiling of children with TB have been described so far. In this study, we have compared whole blood gene expression in childhood TB patients, as well as in healthy latently infected (LTBI) and uninfected (HC) children in a cohort of Warao Amerindians in the Delta Amacuro in Venezuela. We identified a 116-gene signature set by means of random forest analysis that showed an average prediction error of 11% for TB vs. LTBI and for TB vs. LTBI vs. HC in our dataset. Furthermore, a minimal set of only 9 genes showed a significant predictive value for all previously published adult studies using whole blood gene expression, with average prediction errors between 17% and 23%. Additionally, a minimal gene set of 42 genes with a comparable predictive value to the 116-gene set in both our dataset and the previously published literature cohorts for the comparsion of TB vs. LTBI vs. HC was identified. In order to identify a robust representative gene set that would hold stand among different ethnic populations, we selected ten genes that were highly discriminative between TB, LTBI and HC in all literature datasets as well as in our dataset. Functional annotation of these ten genes highlights a possible role for genes involved in calcium signaling and calcium metabolism as biomarkers for active TB. These ten genes were validated by quantitative real-time polymerase chain reaction in an additional cohort of 54 Warao Amerindian children with LTBI, HC and non-TB pneumonia. Decision tree analysis indicated that five of the ten genes were sufficient to diagnose 78% of the TB cases correctly with 100% specificity. We conclude that our data justify the further exploration of our signature set as biomarkers to diagnose childhood TB. Furthermore, as the identification of different biomarkers in ethnically distinct cohorts is apparent, it is important to cross-validate newly identified markers in all available cohorts.
A predictive signature gene set for discriminating active from latent tuberculosis in Warao Amerindian children.
Sex, Age
View SamplesWe previously showed that severe liver diseases are characterized by expansion of liver progenitor cells (LPC), which correlates with disease severity. However, the origin and role of LPC in liver physiology and in the hepatic response to injury remains a contentious topic. We have now used genetic lineage tracing of Hnf1-expressing biliary duct cells to assess their contribution to LPC expansion and hepatocyte generation during normal liver homeostasis, and following different types of liver injury. We found that ductular reaction cells in human cirrhotic livers express HNF1. However, HNF1 expression was not present in newly generated EpCAM-positive hepatocytes. Using a tamoxifen-inducible Hnf1CreER/R26RYFP/LacZ mouse, we show that there is no contribution of the biliary epithelium to hepatocyte turnover during liver homeostasis in healthy mice. Moreover, after loss of liver mass, Hnf1+ LPC did not contribute to hepatocyte regeneration. We also assessed the contribution of Hnf1+ cells following acute and repeated liver injury. All animal models showed expansion of LPC, as assessed by immunostaining and gene expression profile of sorted YFP-positive cells. A contribution of Hnf1+ LPC to hepatocyte generation was not detected in animal models of liver injury with preserved hepatocyte regenerative potential such as acute acetaminophen, carbon tetrachloride injury, or chronic diethoxycarbonyl-1,4-dihydro-collidin (DDC)-diet. However, in mice fed with choline-deficient ethionine-supplemented (CDE)-diet, which causes profound hepatocyte damage and arrest, a small number of hepatocytes were derived from Hnf1+ cells. Conclusion: Hnf1+ cells do not participate in hepatocyte turnover in the healthy liver or during liver regeneration after partial hepatectomy. After liver injury, LPC arise from the biliary duct epithelium, which gives rise to a limited number of hepatocytes only when hepatocyte regeneration is compromised.
The biliary epithelium gives rise to liver progenitor cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide promoter methylation analysis in neuroblastoma identifies prognostic methylation biomarkers.
Treatment
View Samples8 neuroblastoma (NB) cell lines (CLB-GA, IMR-32, SH-SY5Y, N206, CHP-902R, LAN-2, SK-N-AS, SJNB-1) were profiled on the Affymetrix HGU-133plus2,0 platform before and after treatment with DAC (2'-deoxy-5-azacytidine) to investigate the influence on expression after inhibiting DNA-methylation
Genome-wide promoter methylation analysis in neuroblastoma identifies prognostic methylation biomarkers.
Treatment
View SamplesWhen grown on solid substrates, different microorganisms often form colonies with very specific morphologies. Whereas the pioneers of microbiology often used colony morphology to discriminate between species and strains, the phenomenon has not received much recent attention. In this study, we use a genome-wide assay in the model yeast Saccharomyces cerevisiae to identify all genes that affect colony morphology. We show that several major signaling cascades, including the MAPK, TORC, SNF1 and RIM101 pathways play a role, indicating that morphological changes are a reaction to changing environments. Other genes that affect colony morphology are involved in protein sorting and epigenetic regulation. Interestingly, the screen reveals only few genes that are likely to play a direct role in establishing colony morphology, one notable exception being FLO11, a gene encoding a cell-surface adhesin that has already been implicated in colony morphology, biofilm formation, and invasive and pseudohyphal growth. Using a series of modified promoters to tune FLO11 expression, we confirm the central role of Flo11 and show that differences in FLO11 expression result in distinct colony morphologies. Together, our results provide a first comprehensive looks at the complex genetic network that underlies the diversity in the morphologies of yeast colonies.
Identification of a complex genetic network underlying Saccharomyces cerevisiae colony morphology.
No sample metadata fields
View SamplesInteractions between Chronic Lymphocytic Leukemia B-cells (CLL B-cells) and the microenvironment (ME) play a major function in the physiopathology of CLL. Extracellular vesicles (EVs) (composed of exosomes and microparticles) have been shown to play an important role in cell communication. EVs, purified by ultracentrifugation from bone marrow mesenchymal stromal cells (BM-MSC) culture, were added to CLL B-cells. Microarray study highlighted 805 differentially expressed genes between CLL-B-cells cultured with and without EVs. Of these, CCL3/4, EGR1/2/3, MYC (involved in BCR pathway) were increased while pro-apoptotic genes like HRK were decreased. We showed for the first time the potential of EVs alone to induce gene expression modifications in CLL B-cell, notably in BCR and apoptosis pathways. We concluded that a substantial part of communication between CLL B-cells and BM-ME is mediated through EV.
Extracellular vesicles of bone marrow stromal cells rescue chronic lymphocytic leukemia B cells from apoptosis, enhance their migration and induce gene expression modifications.
Specimen part, Subject
View SamplesEndocycle is an alternative cell cycle during which the DNA is replicated in the absence of cytokinesis, resulting in cellular endopolyploidy. The endocycle is frequenctly observed in plant species that grow under extreme conditions. Thus, endopolyploidy has been postulated to be a mechanism facilitating adaptive growth.
A Spatiotemporal DNA Endoploidy Map of the Arabidopsis Root Reveals Roles for the Endocycle in Root Development and Stress Adaptation.
Specimen part
View Samples