Systems biology demonstrates the predominant role of circulating interferon-alpha in primary Sjögren's syndrome and a genetic association with the class II HLA DQ locus
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ABSTRACT: Primary Sjögren’s syndrome (pSS) is the second most frequent systemic autoimmune disease, affecting 0.1% of the general population. No specific immunomodulatory drug has demonstrated efficacy for this disease, and no biomarker is available to identify patients at risk of developing systemic complications. To characterize the molecular and clinical variability across pSS patients, we integrated transcriptomic, proteomic, cellular and genetic data with clinical phenotypes in a cohort of 351 pSS patients. Unbiased global transcriptomic analysis revealed an IFN gene signature as the strongest driver of transcriptomic variability. The resulting stratification was replicated in three independent cohorts. As transcriptomic analysis did not discriminate between type I and II interferons, we applied digital ELISA to find that the IFN transcriptomic signature was driven by circulating IFNɑ protein levels. This cytokine, detectable in 75% of patients, was significantly associated with clinical and immunological features of disease activity at enrollment, and with increased frequency of systemic complications during the 5-year follow-up. Genetic analysis revealed a significant association between IFNɑ protein levels and an MHC-II HLA-DQ locus and anti-SSA antibody. Additional cellular analysis revealed that the polymorphism acts through upregulation of HLA II molecules on conventional DCs. Our unbiased analysis thus identified the predominance of IFNα as driver of pSS variability, and revealed an association with HLA gene polymorphisms.
Project description:Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by infiltration of the exocrine glands and prominent B cell hyperactivity. Considering the key role of monocytes in promoting B cell hyperactivity, we performed RNA-sequencing analysis of CD14+ monocytes from patients with pSS, non-Sjögren’s sicca (nSS), and healthy controls (HC). We demonstrated that the transcriptomic profile of pSS patients is enriched in intermediate and non-classical monocyte profiles, and confirmed the increased frequency of non-classical monocytes in pSS patients by flow-cytometry analysis. Weighted gene co-expression network analysis identified four molecular signatures in monocytes from pSS patients, functionally annotated for processes related with translation, IFN-signaling, and toll like receptor signaling. Systemic and local inflammatory features significantly correlated with the expression of these signatures. Furthermore, genes highly associated with clinical features in pSS were identified as hub-genes for each signature. Unsupervised hierarchical cluster analysis of the hub-genes identified four clusters of nSS and pSS patients, each with distinct inflammatory and transcriptomic profiles. One cluster showed a significantly higher percentage of pSS patients with higher prevalence of anti-SSA autoantibodies, interferon score, and erythrocyte sedimentation rate compared to the other clusters. Finally, we showed that the identified transcriptomic differences in pSS monocytes were induced in monocytes of healthy controls by exposure to serum of pSS patients. Representative hub-genes of all four signatures were partially inhibited by interferon-a/b receptor blockade, indicating that the circulating inflammatory mediators, including type I interferons have a significant contribution to the altered transcriptional profile of pSS-monocytes. Our study suggests that targeting key circulating inflammatory mediators, such as type I interferons, could offer new insights into the important pathways and mechanisms driving pSS, and holds promise for halting immunopathology in Sjögren’s Syndrome.
Project description:Analysis of targets organs might help to get new insights into the pathogenesis of autoimmune diseases. We used global gene expression profiling of minor salivary glands to identify distinct patterns of gene expression in patients with primary Sjögrens syndrome (pSS), a frequent and prototype systemic autoimmune disease. Gene expression signature allowed to distinguish most patients with pSS from healthy controls
Project description:In this comprehensive study, the authors have developed concise models integrating clinical, genomic and transcriptomic features to predict intrinsic resistance to anti-PD1 Immune Checkpoint Blockade (ICB) treatment in individual tumors. It's important to note that their validation was performed in smaller, independent cohorts, constrained by data availability. The authors have developed two Logistic Regression based models for Ipilimumab treated and Ipilimumab naive patients with metastatic melanoma. The main predictive features for the Ipilimumab treated patients are MHC-II HLA, LDH at treatment initiation and the presence of lymph node metastases (LN met), chosen using forward selection methodology. The main predictive features for the Ipilimumab naive patients are tumor heterogeneity, tumor ploidy and tumor purity, chosen using forward selection methodology.
Please note that in these models, the output ‘1’ means progressive disease (PD) and ‘0’ means non-PD. The original GitHub repository can be accessed at https://github.com/vanallenlab/schadendorf-pd1
Project description:Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by lymphocytic infiltration of the exocrine glands and prominent B cell hyperactivity. B cells are crucial in the pathophysiology of pSS through several mechanisms, including cytokine production, exocrine gland destruction, and autoantibody secretion. Considering the central role of B cells we performed RNA-sequencing analysis of circulating CD19+ B cells from patients with pSS, non-Sjögren’s sicca (nSS), and healthy controls (HC).
Project description:Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by lymphocytic infiltration of the exocrine glands. Conventional dendritic cells (cDCs)-2 play a critical role in T and B cell activation, leading to germinal centre formation and autoantibody production. To understand the mechanisms underlying cDC2 dysregulation in pSS we performed RNA-sequencing analysis and functional validation on circulating cDC2s from pSS, non-Sjögren’s sicca (nSS) patients and healthy controls (HC). Two independent cohorts were established to identify reproducible dysregulated signatures, which included the interferon (IFN), toll-like receptors (TLR) signaling and antigen processing and presentation pathways. We confirm by flow cytometry that pSS-cDC2s were less efficient to degrade BSA but more efficient to uptake BSA both linked with the presence of anti-SSA antibodies. As the majority of the SSA+ pSS patients exhibit an IFN-signature, we tested whether IFNα priming would influence cDC2s antigen-uptake and processing. IFNα priming increased cDC2s uptake capacity, but not antigen processing. Additionally, pSS-cDC2s showed an increased uptake capacity of apoptotic salivary gland epithelial cells. Finally, pSS-cDC2s increased the proliferation of HC CD4+ T cells and the expression of CXCR3 and CXCR5 on the proliferating HC CD4+ T cells, contributing to T cell migration into the inflamed salivary glands. Here we provide the first in-depth molecular characterization of pSS-cDC2s and show that the transcriptomic and functional alterations observed in pSS-cDC2s are linked to IFN-signature. In view of its role in pSS immunopathology, delineating the molecular networks that drive cDC2s holds promise for targeting these cells in pSS.
Project description:CCR9+ Tfh-like pathogenic T helper (Th) cells are elevated in patients with primary Sjögren’s syndrome (pSS) and indicated to play a role in pSS immunopathology. CCR9+, CXCR5+ and CCR9-CXCR5- (double negative, DN) Th cells from blood of 7 healthy controls (HC) and 7 pSS patients were FACS sorted and RNA sequencing was performed. Our aim is to delineate the CCR9+ Th cell-specific transcriptome to study the molecular dysregulation of these cells in pSS patients. Transcriptomic analysis of circulating CCR9+ Th cells reveals CCR9-specific pathways involved in effector T cell function, equally expressed in pSS patients and HC. Given the increased numbers of CCR9+ Th cells in the blood and inflamed glands of pSS patients and presence of inflammatory stimuli to activate these cells this suggests that CCR9-specific functions, such as cell recruitment upon CCL5 secretion, could significantly contribute to immunopathology in pSS.
Project description:Primary Sjögren’s syndrome (pSS) is a chronic systemic autoimmune disease characterized by typical autoantibody production and lymphocytic-mediated exocrine gland damage. Interstitial lung disease (ILD) is a common complication of pSS and can be associated with a poor prognosis. However, the pathogenesis of ILD in pSS is still unclear. In this study, we used RNA sequencing to investigate the gene-expression profile of the minor salivary glands (MSGs) from 36 patients with ILD-pSS and 128 patients with non-ILD-pSS. In the remarkably enriched chemokine-mediated signaling pathway, CXCR2 was found to be significantly elevated in both MSG and plasma from pSS patients with versus without ILD (p < 0.001). Furthermore, the CXCR2 expression level in MSG and plasma was significantly associated with the diffusing capacity of the lungs for carbon monoxide, erythrocyte sedimentation rate, and EULAR Sjögren’s Syndrome Disease Activity Index in ILD-pSS. Therefore, with its potential role in ILD progression in patients with pSS and its strong association with clinical manifestations of the disease, CXCR2 may serve as a useful index for disease activity in ILD associated with pSS.
Project description:Fibrotic changes in the myocardium and cardiac arrhythmias represent fatal complications in rheumatic disease systemic sclerosis (SSc), however the underlying mechanisms remain elusive. Fos-related antigen-2 (Fosl-2) has been implicated in development of organ fibrosis. Mice overexpressing Fosl-2 (Fosl-2tg) showed interstitial cardiac fibrosis, disorganized connexin43/40 in intercalated discs and deregulated expression of genes controlling conduction system. Fosl-2tg mice developed higher heart rate (HR), prolonged QT intervals, arrhythmias with prevalence of premature ventricular contractions, ventricular tachycardias, II-degree atrio-ventricular blocks and reduced HR variability. Following stimulation with isoproterenol Fosl-2tg mice showed impaired HR response. To assess the role of inflammation in cardiac fibrosis we used Rag2-/-Fosl-2tg mice lacking T/B cells. These mice showed no myocardial fibrosis and ECG abnormalities. Transcriptomics analysis of cardiac Rag-2-/-Fosl-2wt/Rag2-/-Fosl-2tg/Fosl-2tg fibroblasts revealed that systemic inflammation triggered fibrotic and arrhythmogenic alterations while Fosl-2-overexpression mediated profibrotic signature. In human cardiac fibroblasts FOSL-2-overexpression enhanced myofibroblast signature under proinflammatory or profibrotic stimuli. These results demonstrate that under immunofibrotic conditions activator protein 1 transcription factor component Fosl-2 exaggerates myocardial fibrosis, arrhythmias and aberrant response to stress.
Project description:Primary Sjögren’s syndrome (pSS) is a chronic systemic autoimmune disease characterized by exocrine glands damage and extraglandular manifestations. To identify potential biomarkers for the early diagnosis of pSS and further investigate the potential mechanisms in progression of the disease, we combined our previous RNA- sequencing study and four microarrays data to conduct integrative transcriptome analyses in salivary glands (SGs) between the pSS and non-pSS. Differential gene expression analysis, gene co-expression network analysis and pathway analysis were conducted to detect hub gene, which was subsequently validated in peripheral blood. Correlation analysis, single-gene Gene Set Enrichment Analysis (GSEA) and receiver operating characteristic (ROC) curve were applied to investigate the role of ICOS in pSS and its classification capacity for pSS.
Project description:Primary Sjögren’s syndrome (pSS) is a chronic autoimmune disease characterized by abnormal immune cell activation. This study aimed to investigate differentially expressed long non-coding RNA (lncRNA) in peripheral blood mononuclear cells (PBMCs) in patients with pSS to identify lncRNAs that affect pSS pathogenesis. Transcriptome sequencing detected 38096 lncRNAs and 50869 mRNAs in PBMCs from patients with pSS and healthy individuals. The differentially expressed mRNAs underwent functional enrichment analysis. A protein interaction relationship (PPI) and ceRNA network was constructed. LncRNA expression in patients with pSS and controls was determined using RT-PCR. 1180 lncRNAs and 640 mRNAs were differentially expressed in pSS patients (fold change > 2 in healthy persons). The PPI network was constructed with 640 mRNAs and a ceRNA network with four key lncRNAs (GABPB1-AS1, PSMA3-AS1, LINC00847 and SNHG1). A co-expression relationship was found between GABPB1-AS1 and several upregulated mRNAs (IFI44, IFI44L, IFI6, and EPSTI1). RT-PCR revealed that GABPB1-AS1 and PSMA3-AS1 were significantly upregulated 3.0- and 1.4-fold in the pSS group, respectively. In patients with pSS, the GABPB1-AS1 expression level was positively correlated with B cell and IgG levels. GABPB1-AS1 expression levels are positively correlated with B cell levels and may be involved in the pathogenesis of pSS.