Project description:To gain a comprehensive understanding of gene regulation in CXCL4 and TLR8 signaling crosstalk, we treated primary human blood monocytes with CXCL4 and TLR8 ssRNA ligand ORN8L for 6 h and performed transcriptomic analysis via RNA-seq. We observed that CXCL4 interacted with TLR8 ssRNA ligand and triggered inflammatory cytokine storm including IL6, IL12p40, TNF and IFNβ, and pro-fibrotic gene expression and activated NLRP3 inflammasome leading to interleukin-1β (IL-1β) secretion and pyroptosis in human blood monocytes.
Project description:To gain a comprehensive understanding of gene regulation in CXCL4 and TLR8 signaling crosstalk, we treated primary human blood monocytes with CXCL4 and TLR8 ssRNA ligand ORN8L for 6 h and performed transcriptomic analysis via RNA-seq. We observed that CXCL4 interacted with TLR8 ssRNA ligand and triggered inflammatory cytokine storm including IL6, IL12p40, TNF and IFNβ, and pro-fibrotic gene expression and activated NLRP3 inflammasome leading to interleukin-1β (IL-1β) secretion and pyroptosis in human blood monocytes.
Project description:To investigate the function of RIPK3 in regulation of IFN response and inflammatory response in human monocytes stimulated with CXCL4 and TLR8, We blocks (CXCL4 + TLR8)-induced pyroptosis and RIPK3 activation using necrosulfonamide (NSA, 5 µM) and GSK'872 (10 µM) and measure gene expression genome-wide with RNA-seq.
Project description:Analyses of gene alterations of human Treg cells treated with or without TLR8 ligand using the Illumina whole-genome Human HT-12 BeadChips. The study will provide important information for the molecular signature changes during the reversal of human Treg suppression mediated by activation of TLR8 signaling.
Project description:The innate immune system is equipped with multiple receptors to detect microbial nucleic acids and induce type I interferon (IFN) to restrict viral replication. When dysregulated these receptor pathways induce inflammation in response to host nucleic acids and promote development and persistence of autoimmune diseases like Systemic Lupus Erythematosus (SLE). IFN production is regulated by the Interferon Regulatory Factor (IRF) transcription factor family of proteins that function downstream of several innate immune receptors such as Toll-like receptors (TLRs) and Stimulator of Interferon Genes (STING). Although both TLRs and STING activate the same downstream molecules, the pathway by which TLRs and STING activate IFN response are thought to be independent. Here we show that STING plays a previously undescribed role in human TLR8 signaling. Stimulation with the TLR8 ligands induced IFN secretion in primary human monocytes, and inhibition of STING reduced IFN secretion from primary monocytes from 8 healthy donors. We demonstrate that TLR8-induced IRF activity was reduced by STING inhibitors. Moreover, TLR8-induced IRF activity was blocked by inhibition or loss of IKKε, but not TBK1. Bulk RNA transcriptomic analysis supported a model where TLR8 induces transcriptional responses associated with SLE that can be downregulated by inhibition of STING. These data demonstrate that STING is required for full TLR8-to-IRF signaling and provide evidence for a new framework of crosstalk between cytosolic and endosomal innate immune receptors, which could be leveraged to treat IFN driven autoimmune diseases.
Project description:Human blood monocytes were differentiated over six days with either 100 ng/ml M-CSF or 1 umol/l CXCL4 In atherosclerotic arteries, blood monocytes differentiate to macrophages in the presence of growth factors like macrophage colony-stimulation factor (MCSF) and chemokines like platelet factor 4 (CXCL4). To compare the gene expression signature of CXCL4-induced macrophages with MCSF-induced macrophages or macrophages polarized with IFN-γ/LPS (M1) or IL-4 (M2), we cultured primary human peripheral blood monocytes for six days. mRNA expression was measured by Affymetrix gene chips and differences were analyzed by Local Pooled Error test, Profile of Complex Functionality and Gene Set Enrichment Analysis. 375 genes were differentially expressed between MCSF- and CXCL4-induced macrophages, 206 of them overexpressed in CXCL4 macrophages coding for genes implicated in the inflammatory/immune response, antigen processing/presentation, and lipid metabolism. CXCL4-induced macrophages overexpressed some M1 and M2 genes and the corresponding cytokines at the protein level, however, their transcriptome clustered with neither M1 nor M2 transcriptomes. They almost completely lost the ability to phagocytose zymosan beads. Genes linked to atherosclerosis were not consistently up- or downregulated. Scavenger receptors showed lower and cholesterol efflux transporters higher expression in CXCL4- than MCSF-induced macrophages, resulting in lower LDL content. We conclude that CXCL4 induces a unique macrophage transcriptome distinct from known macrophage types, defining a new macrophage differentiation that we propose to call M4. two MCSF samples and two CXCL4 samples