CD4+ T helper lymphocytes that express interleukin-17 (Th17 cells) have critical roles in mouse models of autoimmunity, and there is mounting evidence that they also influence inflammatory processes in humans. Genome-wide association studies in humans have linked genes involved in Th17 cell differentiation and function with susceptibility to Crohns disease, rheumatoid arthritis, and psoriasis1-3. Thus, the pathway towards differentiation of Th17 cells and, perhaps, of related innate lymphoid cells with similar effector functions4, 5, is an attractive target for therapeutic applications. Mouse and human Th17 cells are distinguished by expression of the retinoic acid receptor-related orphan nuclear receptor RORt, which is required for induction of IL-17 transcription and for the manifestation of Th17-dependent autoimmune disease in mice6. By performing a chemical screen with an insect cell-based reporter system, we identified the cardiac glycoside digoxin as a specific inhibitor of RORt transcriptional activity. Digoxin inhibited murine Th17 cell differentiation without affecting differentiation of other T cell lineages and was effective in delaying the onset and reducing the severity of autoimmune disease in mice. At high concentrations, digoxin is toxic for human cells, but non-toxic synthetic derivatives, 20,22-dihydrodigoxin-21,23-diol (Dig(dhd)) and digoxin-21-salicylidene (Dig(sal)), specifically inhibited induction of IL-17 in human CD4+ T cells. Using these small molecule compounds, we demonstrated that RORt is imporant for the maintenance of IL-17 expression in mouse and human effector T cells. These data suggest that derivatives of digoxin can be used as chemical probes for development of RORt-targeted therapeutic agents that attenuate inflammatory lymphocyte function and autoimmune disease.
Digoxin and its derivatives suppress TH17 cell differentiation by antagonizing RORγt activity.
Treatment
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we used a mouse model of T-ALL through the overexpression of the intarcellular transcriptionally active part of Notch1 (N1-IC). This model faithfully recapitulates the major characteristics of the human disease. Comparison of the leukemic cells from peripheral tumors(thymoma) of this mouse model to normal thymic cells Double Positive (DP) for the markers CD4 and CD8 that express very low levels of Notch1 showed major expression changes in pathways controlling the transition from physiology to disease. Further correlation of the data to ChIP-Seq data from the same cell populations led us to identify a hitherto unknown antagonism of the Notch1 oncogenic pathway and the polycomb complex (PRC2) in leukemia. Importantly exome sequencing in primary samples from human patients with T-ALL revealed that the PRC2 complex is frequently mutated and inactivated, further supporting the tumor suppressor role of the complex in this disease.
Genetic inactivation of the polycomb repressive complex 2 in T cell acute lymphoblastic leukemia.
Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Regulation of transcriptional elongation in pluripotency and cell differentiation by the PHD-finger protein Phf5a.
Specimen part, Cell line
View SamplesArsenic contamination of drinking water occurs globally and is associated with numerous diseases including skin, lung, and bladder cancers, and cardiovascular disease. The mechanisms behind arsenic's effects remain unclear, but recent research indicates that aresnic acts along sex-specific lines and may be an endocrine disruptor. The objective of this study was to evaluate the nature of gene expression chagnes among males and females exposed to arsenic contaminated water in Bangladesh at high and low dose exposures.The median wAs concentration for the low exposure group was 103 g/L for males and 117 g/L for females (range 50200 g/L). For the high exposure group, the median wAs concentration was 355 g /L for males (range 250-500 g /L) and 434 g/L for females (range 2321000 g /L). The PBMCs of males with high exposure compared to those with low exposure there were 534 differentially expressed genes (p <0.05); and for females with high exposure relative to low exposure there were 645 differentially expressed genes (p <0.05) in PBMCs of females.
Sex-specific patterns and deregulation of endocrine pathways in the gene expression profiles of Bangladeshi adults exposed to arsenic contaminated drinking water.
Sex, Specimen part
View SamplesReversing gene expression signatures in relapsed patient may restore chemosensitivity.
Epigenetic reprogramming reverses the relapse-specific gene expression signature and restores chemosensitivity in childhood B-lymphoblastic leukemia.
Specimen part, Disease, Disease stage, Cell line, Treatment
View SamplesThe gastrointestinal tract of mammals is inhabited by hundreds of distinct species of commensal microorganisms that exist in a mutualistic relationship with the host. The process by which the commensal microbiota influence the host immune system is poorly understood. We show here that colonization of the small intestine of mice with a single commensal microbe, segmented filamentous bacterium (SFB), is sufficient to induce the appearance of CD4+ T helper cells that produce IL-17 and IL-22 (Th17 cells) in the lamina propria. SFB adhere tightly to the surface of epithelial cells in the terminal ileum of mice with Th17 cells but are absent from mice that have few Th17 cells. Colonization with SFB was correlated with increased expression of genes associated with inflammation, anti-microbial defenses, and tissue repair, and resulted in enhanced resistance to the intestinal pathogen Citrobacter rodentium. Control of Th17 cell differentiation by SFB may thus establish a balance between optimal host defense preparedness and potentially damaging T cell responses. Manipulation of this commensal-regulated pathway may provide new opportunities for enhancing mucosal immunity and treating autoimmune disease.
Induction of intestinal Th17 cells by segmented filamentous bacteria.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Neuropilin 1 is expressed on thymus-derived natural regulatory T cells, but not mucosa-generated induced Foxp3+ T reg cells.
Specimen part
View SamplesPhf5a regulates transcription elongation in mouse embryonic stem cells (ESCs), through regulation of the Paf1 complex.
Regulation of transcriptional elongation in pluripotency and cell differentiation by the PHD-finger protein Phf5a.
Specimen part, Cell line
View SamplesDendritic cells (DC) serve a key function in host defense, linking innate detection of microbes to the activation of pathogen-specific adaptive immune responses. Whether there is cell-intrinsic recognition of HIV-1 by host innate pattern-recognition receptors and subsequent coupling to antiviral T cell responses is not yet known. DC are largely resistant to infection with HIV-1, but facilitate infection of co-cultured T-helper cells through a process of trans-enhancement. We show here that, when DC resistance to infection is circumvented, HIV-1 induces DC maturation, an antiviral type I interferon response and activation of T cells. This innate response is dependent on the interaction of newly-synthesized HIV-1 capsid (CA) with cellular cyclophilin A (CypA) and the subsequent activation of the transcription factor IRF3. Because the peptidyl-prolyl isomerase CypA also interacts with CA to promote HIV-1 infectivity, our results suggest that CA conformation has evolved under opposing selective pressures for infectivity versus furtiveness. Thus, a cell intrinsic sensor for HIV-1 exists in DC and mediates an antiviral immune response, but it is not typically engaged due to absence of DC infection. The virulence of HIV-1 may be related to evasion of this response, whose manipulation may be necessary to generate an effective HIV-1 vaccine.
A cryptic sensor for HIV-1 activates antiviral innate immunity in dendritic cells.
Specimen part
View SamplesiTreg cells from Tbmc mLN mice treated with one week of 1% Oral Ova were compared to Total Treg from WT mice.
Neuropilin 1 is expressed on thymus-derived natural regulatory T cells, but not mucosa-generated induced Foxp3+ T reg cells.
Specimen part
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