AI Article Synopsis

  • Scientists studied how certain immune cells respond to a signal that usually helps the body fight infections in people with a condition called primary Sjögren's syndrome (pSS).
  • They found that specific immune cells in pSS patients can produce more of a signaling molecule called IFNα when activated, even compared to healthy people.
  • The research suggests that these immune cells are very sensitive to the signal and may react strongly, not just in patients with high levels of this immune response.

Article Abstract

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.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9348764PMC
http://dx.doi.org/10.1093/rheumatology/keac016DOI Listing

Publication Analysis

Top Keywords

pss monocytes
16
ifn-i pathway
12
pathway activation
12
monocytes pdcs
12
pss sle
12
sting
11
pss
10
cytosolic dna-sensing
8
dna-sensing pathway
8
monocytes
8

Similar Publications

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.

View Article and Find Full Text PDF
Article Synopsis
  • Systemic sclerosis (SSc) is an autoimmune disease that is often overlooked compared to others like rheumatoid arthritis, and this study examines gene expression and immune cell profiles in patients with SSc.
  • * RNA sequencing data from 119 patients and healthy controls revealed 1,148 differentially expressed genes (DEGs) unique to SSc, indicating altered megakaryocyte processes and decreased neutrophil function.
  • * The findings point to shared pathogenic pathways in autoimmune diseases, specifically emphasizing megakaryocyte proliferation, and suggest potential new targets for SSc treatment.*
View Article and Find Full Text PDF

Toll-Like Receptor 8 is Expressed in Monocytes in Contrast to Plasmacytoid Dendritic Cells and Mediates Aberrant Interleukin-10 Responses in Patients With Systemic Sclerosis.

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 PDF
Article Synopsis
  • - The study explores the role of VNN2 expression in monocytes and its importance in diagnosing primary Sjögren's syndrome (pSS).
  • - Researchers used single-cell RNA sequencing and flow cytometry to analyze VNN2 levels in different monocyte types, finding that VNN2 is less expressed in pSS patients compared to healthy individuals.
  • - Findings indicate that lower levels of VNN2 monocytes are linked with specific clinical indicators, suggesting VNN2 could serve as a useful diagnostic marker for pSS.
View Article and Find Full Text PDF

Elevated unphosphorylated STAT1 and IRF9 in T and B cells of primary sjögren's syndrome: Novel biomarkers for disease activity and subsets.

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:

Article Synopsis
  • The study investigates how interferon (IFN) signaling pathways affect autoantibody production and symptoms in primary Sjögren's syndrome (pSS), aiming to improve diagnostics and personalized treatments.
  • Researchers analyzed samples from 34 pSS patients and 38 healthy donors, finding elevated IFN pathway molecules like STAT1, STAT2, and IRF9 in most T and B cells from patients, indicating heightened signaling activity.
  • Results suggest that high levels of STAT1 and IRF9 are linked to specific autoimmune features and can serve as biomarkers for disease severity and the presence of extraglandular symptoms in pSS patients.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!