Project description:MicroRNAs are a class of non-coding short-chained RNAs that control cellular functions by downregulating their target genes. Recent research indicates that microRNAs play a role in the maintenance of gut homeostasis. miR-215 was found to be highly expressed in epithelial cells of the small intestine; however, the involvement of miR-215 in gut immunity remains unknown. Here, we show that miR-215 negatively regulates inflammation in the small intestine by inhibiting CXCL12 production. Mice lacking miR-215 showed high susceptibility to inflammation induced by indomethacin, accompanied by an increased number of Th17 cells in the lamina propria of the small intestine. Our findings support a promising perspective of targeting miR-215 to treat inflammatory conditions in the small intestine.
Project description:Interleukin 17 (IL-17) producing T helper 17 (Th17) cells are critical drivers of pathogenesis in a variety of autoimmune and inflammatory diseases. Strategies to mitigate excessive Th17 response thus remain an attractive target for immunotherapies. Here we report that Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) regulates IL-17 production by Th17 cells in human and mouse. Using CIP2A knock-out (KO) mice and siRNA-mediated CIP2A silencing in human primary CD4+ T cells, we demonstrated that CIP2A silencing results in a significant increase in IL-17 production. Interestingly, CIP2A deficient Th17 cells were characterized by increased strength and duration of STAT3 (Y705) phosphorylation. Genome-wide gene expression profile as well as the p-STAT3 (Y705) interactome of CIP2A deficient Th17 cells identified that CIP2A regulates the strength of the interaction between Acylglycerol kinase (AGK) and STAT3, and thereby, modulates STAT3 phosphorylation as well as expression of IL-17 in Th17 cells. Our results uncover the physiological function of CIP2A in Th17 cells and provides new opportunities for therapeutic intervention in Th17 cell mediated diseases.
Project description:Interferon-alpha (IFNα) plays a ciritical role in immune regulation, especially in tumor microenvironment. Our previous study has demonstrated that IFNα promoted immunosuppression formation in head and neck squamous cell carcinoma. To explore the mechanism underlying IFNα-induced immunosuppression, long noncoding RNA (lncRNA) sequece was conduted. We identified a novel IFNα-induced upregulated lncRNA, lncMX1-215 in HNSCC. It was mainly located in cell nucleus. Ectopic expression of lncMX1-215 markedly inhibited IFNα-induced immunosuppression molecules, programmed cell death 1 ligand 1(PD-L1) and galectin-9 expression, and vice versa. Subsequently, histone deacetylase (HDAC) inhibitors promoted the expression of PD-L1 and galectin-9. There were binding sites of H3K27 acetylation on PD-L1 and galectin-9 promoters. Mechanically, we find that lncMX1-215 directly interacted with GCN5, a known H3K27 acetylase to interrupt its binding to H3K27 acetylation. Clinically, negative correlations between lncMX1-215 and PD-L1, galectin-9 were observed. Finally, overexpression of lncMX1-215 suppressed the proliferation and metastasis capacity in vitro and in vivo in HNSCC. Our results suggest that lncMX1-215 negatively regulates immunosuppression through interrupting GCN5/H3K27ac in HNSCC and provides novel insights into immune checkpoint blockade treatment.
Project description:Purpose: To identify novel genes regulated by the aryl hydrocarbon receptor that influence human Th17 cell function. Methods: Naïve CD4 T cells from peripheral blood of six healthy human volunteers were cultured under four experimental conditions for three days: anti-CD3 and anti-CD28 antibodies (Media control), Media with Th17 conditions (IL-6, TGF-b, IL-1b, IL-23), Th17+FICZ and Th17+CH223191. Total RNA was extracted from each sample on day 3 and sequenced in a paired-end 2x50bp strategy on an Illumina HiSeq1500. A total of six donors were analyzed. Results: AhR activation with FICZ suppressed IL-17 production from human CD4 T cells and increased IL-22. AhR inhibition with CH223191 potently suppressed IL-22 and modestly increased IL-17 production. On day 3, the number of significantly regulated genes for each treatment were 975 (Th17), 88 (Th17+FICZ) and 142 (Th17+CH223191). 11 common genes were significantly regulated by all three treatments. One of these, GPR68, was investigated further in functional studies since its expression correlated with IL-22 production. Activation of GPR68 with a positive allosteric modulator suppressed IL-22 concentrations in human Th17 cell cultures. Conclusions: Our study demonstrates that GPR68 activation can negatively regulate IL-22 production from human CD4 T cells in the presence of an AhR agonist. RNA-seq is a powerful method to identify novel gene targets that regulate cytokines involved in chronic inflammatory diseases.
Project description:RORγt is well recognized as the lineage defining transcription factor for TH17 cell development. However, the cell-intrinsic mechanisms that negatively regulate TH17 cell development and autoimmunity remain poorly understood. Here we demonstrate that the transcriptional repressor REV-ERBa is exclusively expressed in TH17 cells, competes with RORγt for their shared DNA consensus sequence, and negatively regulates TH17 cell development via repression of genes traditionally characterized as RORγt-dependent, including Il17a. Deletion of REV-ERBa enhanced TH17-mediated pro-inflammatory cytokine expression, exacerbating experimental autoimmune encephalomyelitis (EAE) and colitis. Treatment with REV-ERB-specific synthetic ligands, which have similar phenotypic properties as RORγ modulators, suppressed TH17 cell development, was effective in colitis intervention studies, and significantly decreased the onset, severity, and relapse rate in several models of EAE without affecting thymic cellularity. Our results establish that REV-ERBa negatively regulates pro-inflammatory TH17 responses in vivo and identifies the REV-ERBs as potential targets for the treatment of TH17-mediated autoimmune diseases.
Project description:Comparison of gene expression in pterygium fibroblast cells after 24 h treatment with hsa-miR-215 mimic or non-specific oligonucleotide control 100nM miR-215 mimic (Thermo Scientific) or non-specific control oligonucleotides are added to cultured fibroblast cells for 24 hours
Project description:We identified a Mariner transposase helix-turn-helix (HTH) DNA-binding domain that was captured in the Caenorhabditis genus by a subset of F-box genes, which we refer to as F-box A2 genes. The origin of F-box A2 genes likely occurred through a single transposase capture event, followed by an increase in copy number. We focused on fbxa-215, a F-box A2 gene highly expressed in the C. elegans germline and embryos, and that localizes to germ granules in embryos. The HTH domain of FBXA-215 is required for fertility and displays predominantly a signature of purifying selection, highlighting the importance of this domain. As the HTH domain of FBXA-215 is related to the DNA-binding HTH domain of transposases, we reasoned that FBXA-215 may bind to DNA in C. elegans and thus regulate gene expression at the transcriptional level. We performed mRNA sequencing of young adults and embryos to test this, but found no clear deregulation of protein-coding genes and transposable elements upon complete deletion of fbxa-215.