Effect of high mobility group box 1 on Toll-like receptor 9 in B cells in myeloperoxidase-ANCA-associated vasculitis.

Abstract

High mobility group box 1 (HMGB1) played pathogenic role in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Recent findings demonstrated that Toll-like receptor 9 (TLR9) was involved in B cell tolerance breaking of autoimmune disease, including AAV. Here, we investigated the effect of HMGB1 on TLR9 in B cells of AAV. In the present work, patients with myeloperoxidase (MPO)-AAV in active stage were recruited. Intracellular TLR9 expression in various B cell subpopulations of the whole blood was detected by flow cytometry and the correlation with clinical data was analysed. Our results showed that intracellular TLR9 expression in B cells, memory B cells and plasmablasts correlated with erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP). In particular, TLR9 expression in plasma cells correlated with ESR, CRP, serum creatinine, eGFR, and Birmingham Vasculitis Activity Score. To further explore the effect of HMGB1 on B cell, peripheral blood mononuclear cells (PBMCs) from AAV patients were isolated. After stimulated with HMGB1, TLR9 expression in various B cell subpopulations and proliferation ratio of live B cells were analysed by flow cytometry. We found that TLR9 expression in plasma cells and the proliferation ratio of live B cells by HMGB1 stimulation were significantly upregulated compared with the control group. Therefore, TLR9 expression in plasma cells was associated with disease activity of MPO-AAV. HMGB1 could enhance TLR9 expression in plasma cells and B cell proliferation. These indicated a role of HMGB1 on TLR9 in B cells in MPO-AAV, which would provide potential clues for intervention strategies.

• Authors: Chen Wang, Hui Deng, Yan Gong, Ran You, Min Chen, Ming-Hui Zhao
• Journal: Autoimmunity (Autoimmunity) Vol. 53 Issue 1 Pg. 28-34 (02 2020) ISSN: 1607-842X [Electronic] England
• PMID: 31790283 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• HMGB1 Protein
• TLR9 protein, human
• Toll-Like Receptor 9
• Peroxidase

Topics

• Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis (diagnosis, etiology, metabolism)
• Autoimmune Diseases
• Autoimmunity
• B-Lymphocyte Subsets (immunology, metabolism)
• B-Lymphocytes (immunology, metabolism)
• Biomarkers
• HMGB1 Protein (genetics, metabolism)
• Humans
• Immunophenotyping
• Leukocytes, Mononuclear (immunology, metabolism)
• Lymphocyte Activation (immunology)
• Peroxidase (metabolism)
• Toll-Like Receptor 9 (genetics, metabolism)