Objectives: Cytosolic DNA-sensing pathway stimulation prompts type I IFN (IFN-I) production, but its role in systemic IFN-I pathway activation in primary SS (pSS) is poorly studied. Here we investigate the responsiveness of pSS monocytes and plasmacytoid dendritic cells (pDCs) to stimulator of interferon genes (STING) activation in relation to systemic IFN-I pathway activation and compare this with SLE.
Methods: Expression of DNA-sensing receptors cGAS, IFI16, ZBP-1 and DDX41, signalling molecules STING, TBK1 and IRF3, positive and negative STING regulators, and IFN-I-stimulated genes MxA, IFI44, IFI44L, IFIT1 and IFIT3 was analysed in whole blood, CD14+ monocytes, pDCs, and salivary glands by RT-PCR, monocyte RNA sequencing data, flow cytometry and immunohistochemical staining. Peripheral blood mononuclear cells (PBMCs) from pSS, SLE and healthy controls (HCs) were stimulated with STING agonist 2'3'-cGAMP. STING phosphorylation (pSTING) and intracellular IFNα were evaluated using flow cytometry.
Results: STING activation induced a significantly higher proportion of IFNα-producing monocytes, but not pDCs, in both IFN-low and IFN-high pSS compared with HC PBMCs. Additionally, a trend towards more pSTING+ monocytes was observed in pSS and SLE, most pronounced in IFN-high patients. Positive STING regulators TRIM38, TRIM56, USP18 and SENP7 were significantly higher expression in pSS than HC monocytes, while the dual-function STING regulator RNF26 was downregulated in pSS monocytes. STING was expressed in mononuclear infiltrates and ductal epithelium in pSS salivary glands. STING stimulation induced pSTING and IFNα in pSS and SLE pDCs.
Conclusion: pSS monocytes and pDCs are hyperresponsive to stimulation of the STING pathway, which was not restricted to patients with IFN-I pathway activation.
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http://dx.doi.org/10.1093/rheumatology/keac016 | DOI Listing |
Heliyon
October 2024
Department of Rheumatology and Immunology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Background: Primary Sjögren's syndrome (pSS) stands as a chronic autoimmune disease characterized by an elusive pathogenesis. The synergy of single-cell RNA sequencing and Mendelian randomization (MR) analysis provides an opportunity to comprehensively unravel the contributory role of monocytes/macrophages in the intricate pathogenesis of pSS.
Methods: Differentially expressed genes (DEGs) of various types of immune cells were analyzed after annotating single-cell RNA sequencing (scRNA-seq) data.
Arch Med Res
August 2024
Division of Rheumatology, School of Medicine, University of California at Los Angeles, California, USA.
Arthritis Rheumatol
August 2024
Junior Research Group for Translational Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany, Biomedical Research in End-Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany, and Department for Rheumatology and Immunology, Hannover Medical School, Hannover, Germany.
Objective: Systemic sclerosis (SSc) is a severe rheumatic disease causing fibrotic tissue rearrangement. Aberrant toll-like receptor (TLR) 8 transcripts in plasmacytoid dendritic cells (pDCs) were recently linked to SSc pathogenesis, which is at least partially mediated by increased type I interferon (IFN-I) responses. Here, we addressed the functional role of TLR8 signaling in different immune cell subsets of patients with SSc.
View Article and Find Full Text PDFJ Autoimmun
July 2024
Department of Clinical Laboratory, Peking University People's Hospital, Beijing, China. Electronic address:
J Autoimmun
July 2024
Department of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany; German Rheumatism Research Center (DRFZ), a Leibniz Gesellschaft, Berlin, Germany. Electronic address:
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