Elevated expression of Toll-like receptor 7 and its correlation with clinical features in patients with primary Sjögren's syndrome.

BACKGROUND: The labial salivary glands (LSGs) are important for the diagnosis, evaluation of therapeutic efficacy, and genetic analyses of primary Sjögren's syndrome (pSS). In autoimmune diseases, the recognition of self nucleic acids and viral RNA and DNA through endogenous Toll-like receptor(TLR) triggers the production of type I IFN and pro-inflammatory cytokines, leading to the occurrence and progression of the disease. Here, we detected the expression of TLR7 in LSGs and analyse its correlation with clinical features and serum cytokines in pSS patients. METHODS: LSGs and serum samples were obtained from 56 pSS patients and 19 non-SS patients (non-pSS patients). The expression of TLR7 in the LSGs was evaluated with immunohistochemistry. The serum levels of interferon-α (IFN-α) and interleukin-6 (IL-6) were quantified by ELISA. Laboratory parameters were measured by clinical standard laboratory techniques. RESULTS: TLR7-positive cells in pSS were localized in the ductal epithelial cells and lymphocytes of LSGs. The expression of TLR7 was upregulated in pSS patients compared with controls. Patients with anti-Ro52 antibody positivity showed higher TLR7 levels than those who were negative but not those with anti-Ro60 and anti-SSB. TLR7 levels were positively associated with the levels of IgG, IgA, ANA, IL-6, IFN-α and serum globulin but were not associated with IgM, C3, C4, or rheumatoid factor (RF) in serum. CONCLUSION: TLR7 may be involved in the inflammatory response and the production of antibodies in pSS and plays an important role in local and systemic pSS manifestations. This research showed that TLR7 is involved in pSS pathogenesis.

Identification of ferroptosis-related diagnostic markers in primary Sjögren's syndrome based on machine learning / Identificación de marcadores diagnósticos relacionados con la ferroptosis en el síndrome de Sjögren primario basado en aprendizaje automático

Background: Primary Sjogren's syndrome (pSS) is a common autoimmune disorder that affects up to 0.3-3% of the global population. Ferroptosis has recently been identified to play a significant role in autoimmune diseases. However, the molecular mechanisms of ferroptosis in the initiation and progression of pSS remains unclear. Material and Methods: To investigate the molecular mechanisms underlying the occurrence and progression of pSS, we utilized a comprehensive approach by integrating data obtained from the Gene Expression Omnibus (GEO) database with data from the FerrDb database to identify the ferroptosis-related differentially expressed genes (DEGs). Furthermore, we implemented an innovative transcriptomic analysis method utilizing a computer-aided algorithm to establish a network between hub genes associated with ferroptosis and the immune microenvironment in pSS patients. Results: Our results revealed significant differences in the gene expression profiles of pSS samples compared to normal tissues, with 1,830 significantly up-regulated genes and 1,310 significantly down-regulated genes. In addition, our results showed a significant increase in the proportions of B cells and CD4+ T cells in pSS samples compared to normal tissues. AND then, our analysis revealed that a combination of six ferroptosis-related genes, including TBK1, SLC1A4, PIK3CA, ENO3, EGR1, and ATG5, could serve as optimal markers for the diagnosis of pSS. The combined analysis of these six genes accurately diagnosed the occurrence of pSS. Conclusions: This study offers valuable insights into the pathogenesis of pSS and highlights the importance of targeting ferroptosis-related DEGs, which suggests a novel treatment strategy for pSS.(AU)

[The proportion of CD19+CD25+ Bregs in peripheral blood and the expression of PD-1 and PD-L1 on cell surface in patients with systemic lupus erythematosus and their correlation with clinical indicators].

Objective To investigate the expression and clinical significance of PD-1 and its ligand PD-L1 in peripheral blood CD19+CD25+ regulatory B cells (Bregs) in patients with systemic lupus erythematosus (SLE). Methods Peripheral blood samples were collected from 50 patients and 41 healthy controls (HCs). The proportion of CD19+CD25+Bregs in peripheral blood as well as the expression of PD-1+B and PD-L1+B cells on CD19+CD25+/-B cells, were detected by flow cytometry. At the same time, clinical information, such as clinical manifestations and laboratory indexes, was collected from patients. CD4+T cells and CD19+B cells were isolated by immunomagnetic beads and co-cultured in vitro to detect the differentiation of Bregs. Results The proportion of CD19+CD25+Bregs in the peripheral blood of SLE patients was lower than that in HC, while the expression of PD-1 and PD-L1 on Bregs was higher than that in HCs. SLE patients with pleural effusion, arthritis, and elevated CRP had a higher frequency of Bregs compared to the corresponding negative group. SLE patients with decreased immunoglobulin M (IgM) and positive anti-ribonuclear protein (RNP) antibodies had a lower frequency of Bregs compared to the corresponding negative group. SLE patients with infection, fever, arthritis, and elevated immunoglobulin A (IgA) had a higher frequency of CD19+CD25+PD-1+ cells compared to the corresponding negative group. SLE patients with infection, fever, and elevated IgA had a higher frequency of CD19+CD25+PD-L1+ cells compared to the corresponding negative group. And activated CD4+T cells were beneficial to the expression of CD25 on CD19+B cells. Conclusion The peripheral blood CD19+CD25+ Bregs are decreased in SLE patients, while the expression of PD-1 and PD-L1 on cell surface is increased, which is correlated with clinical manifestations and laboratory parameters. Activation of CD4+T cells promotes the differentiation of Bregs.

Efficient delivery of the lncRNA LEF1-AS1 through the antibody LAIR-1 (CD305)-modified Zn-Adenine targets articular inflammation to enhance the treatment of rheumatoid arthritis.

BACKGROUNDS: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by synovial hyperplasia. Maintaining a balance between the proliferation and apoptosis of rheumatoid arthritis synovial fibroblasts (RASFs) is crucial for preventing the erosion of bone and cartilage and, ultimately, mitigating the progression of RA. We found that the lncRNA LEF1-AS1 was expressed at low levels in the RASFs and inhibited their abnormal proliferation by targeting PIK3R2 protein and regulating the PI3K/AKT signal pathway through its interaction with miR-30-5p. In this study, we fabricated a nano-drug delivery system for LEF1-AS1 using Zn-Adenine nanoparticles (NPs) as a novel therapeutic strategy against RA. METHODS: The expression levels of LEF1-AS1, miR-30-5p, PIK3R2, p-PI3K, and p-AKT were detected in the primary RASFs and a human fibroblast-like synovial cell line (HFLS). Zn-Adenine nanoparticles (NPs) were functionalized with anti-CD305 antibody to construct (Zn-Adenine)@Ab. These NPs were then loaded with LEF1-AS1 to form (Zn-Adenine)@Ab@lncRNA LEF1-AS1. Finally, the (Zn-Adenine)@Ab@lncRNA LEF1-AS1 NPs were locally injected into a rat model with collagen-induced arthritis (CIA). The arthritic injuries in each group were evaluated by HE staining and other methods. RESULTS: LEF1-AS1 was expressed at low levels in the primary RASFs. High expression levels of LEF1-AS1 were detected in the HFLS cells, which corresponded to a significant downregulation of miR-30-5p. In addition, the expression level of PIK3R2 was significantly increased, and that of p-PI3K and p-AKT were significantly downregulated in these cells. The (Zn-Adenine)@Ab@lncRNA LEF1-AS1 NPs significantly inhibited the proliferation of RASFs and decreased the production of inflammatory cytokines (IL-1ß, IL-6, TNF-α). Intra-articular injection (IAI) of (Zn-Adenine)@Ab@lncRNA LEF1-AS1 NPs significantly alleviated cartilage destruction and joint injury in the CIA-modeled rats. CONCLUSIONS: LEF1-AS1 interacts with miR-30-5p to inhibit the abnormal proliferation of RASFs by regulating the PI3K/AKT signal pathway. The (Zn-Adenine)@Ab NPs achieved targeted delivery of the loaded LEF1-AS1 into the RASFs, which improved the cellular internalization rate and therapeutic effects. Thus, LEF1-AS1 is a potential target for the treatment of RA.

The effect of PD-1/PD-L1 signaling axis on the interaction between CD19+B cells and CD4+T cells in peripheral blood of patients with systemic lupus erythematosus.

BACKGROUND: The defect of B cell self-tolerance and the continuous antigen presentation by T cells (TCs) mediated by autoreactive B cells (BCs) play a key role in the occurrence and development of systemic lupus erythematosus (SLE). PD-1/PD-L1 signaling axis negatively regulates the immune response of TCs after activation and maintains immune tolerance. However, the effect of PD-1/PD-L1 signaling axis on the interaction between CD19+B/CD4+TCs in the peripheral blood of patients with SLE has not been studied in detail. METHODS: PD-1/PD-L1 and Ki-67 levels in peripheral blood (PB) of 50 SLE patients and 41 healthy controls (HCs) were detected through flow cytometry, and then the expression of PD-1+/-cells and PD-L1+/-cells Ki-67 was further analyzed. CD19+B/CD4+TCs were separated for cell culture and the supernatant was collected to determine proliferation and differentiation of TCs. IL-10 and IFN-γ secretion in the supernatant was also determined using ELISA. RESULTS: The PD-1, PD-L1, and Ki-67 levels on CD19+B/CD4+TCs in patients with SLE were higher than HCs. In CD19+B/CD4+TCs of SLE patients, the proliferative activity of PD-L1+ cells was higher than that of PD-L1- cells, and the proliferative activity of PD-1+ cells was higher than that of PD-1- cells. In the system co-culturing CD19+B/CD4+TCs from HCs/SLE patients, activated BCs promoted TCs proliferation and PD-L1 expression among TCs. Addition of anti-PD-L1 to co-culture system restored the proliferation of TCs, and inhibited IL-10/IFN-γ level. The addition of anti-PD-L1 to co-culture system also restored Tfh and downregulated Treg in HCs. CONCLUSIONS: Axis of PD-1/PD-L1 on CD19+B/CD4+TCs in PB of SLE patients is abnormal, and cell proliferation is abnormal. In CD19+B/CD4+TCs of SLE patients, the proliferative activity of PD-L1+ and PD-1+ cells compared with PD-L1- and PD-1- cells in SLE patients, respectively. CD19+B/CD4+TCs in SLE patients can interact through PD-1/PD-L1.

Role of ceRNA network in inflammatory cells of rheumatoid arthritis. / CeRNAç½‘ç»œåœ¨ç±»é£Žæ¹¿å ³èŠ‚ç‚Žçš„ç‚Žç—‡ç»†èƒžä¸­çš„ä½œç”¨.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease caused by inflammatory cells. Various inflammatory cells involved in RA include fibroblast-like synoviocytes, macrophages, CD4+T-lymphocytes, B lymphocytes, osteoclasts and chondrocytes. The close interaction between various inflammatory cells leads to imbalance of immune response and disorder of the expression of mRNA in inflammatory cells. It helps to drive production of pro-inflammatory cytokines and stimulate specific antigen-specific T- and B-lymphocytes to produce autoantibodies which is an important pathogenic factor for RA. Competing endogenous RNA (ceRNA) can regulate the expression of mRNA by competitively binding to miRNA. The related ceRNA network is a new regulatory mechanism for RNA interaction. It has been found to be involved in the regulation of abnormal biological processes such as proliferation, apoptosis, invasion and release of inflammatory factors of RA inflammatory cells. Understanding the ceRNA network in 6 kinds of RA common inflammatory cells provides a new idea for further elucidating the pathogenesis of RA, and provides a theoretical basis for the discovery of new biomarkers and effective therapeutic targets.

Serological and clinical associations of autoantibodies in Chinese patients with new-onset systemic lupus erythematosus.

To study the clinical significance of autoantibodies in Chinese patients with new-onset systemic lupus erythematosus (SLE), we enrolled 526 new-onset patients who met the 1997 Updated American College of Rheumatology SLE Classification Criteria for a retrospective cohort study. Chi-square test and Wilcoxon rank-sum test were used to detect the relationship of autoantibodies with clinical manifestations and serological results respectively. Our results demonstrated that the positive rate of anti-ribosomal P protein (anti-P) antibody in female patients was higher than that in male patients (41.2% vs. 22%, P = 0.008). Patients with anti-SSB (43.95 ± 73.12 vs. 40.92 ± 75.75, P = 0.004; 63.93 ± 103.56 vs. 55.06 ± 120.84, P = 0.008 respectively) antibodies had higher levels of alanine aminotransferase (ALT) and aspartate transaminase (AST), whereas those with anti-P antibody (28.90 ± 25.70 vs. 50.08 ± 93.00, P = 0.014; 38.51 ± 48.19 vs. 69.95 ± 142.67, P = 0.047, respectively) had lower levels of them. Anti-dsDNA antibody (P = 0.021) was associated with pulmonary arterial hypertension (PAH). The patients with anti-Ro60 (P = 0.044), anti-P (P = 0.012) and anti-dsDNA (P = 0.013) antibodies were less likely to develop Interstitial lung disease. Anti-SmRNP antibody was correlated to lower prevalence of neuropsychiatric symptoms (P = 0.037), and patients with anti-centromere antibody (ACA) were more likely to develop serositis (P = 0.016).We identified five clusters of SLE-related autoantibodies, confirmed previously reported associations of autoantibodies, and discovered new associations.

Role of sPD-1 and sPD-Ls in the pathogenesis of connective tissue disease. / sPD-1和sPD-Lsåœ¨ç»“ç¼”ç»„ç»‡ç— å‘ç— æœºåˆ¶ä¸­çš„ä½œç”¨.

Membrane-bound programmed cell death-1 (mPD-1) and membrane-bound programmed cell death-ligands (mPD-Ls) have soluble forms, which are soluble programmed cell death-1 (sPD-1) and soluble programmed cell death-ligands (sPD-Ls) [including soluble programmed cell death-ligand 1 (sPD-L1) and soluble programmed cell death-ligand 2 (sPD-L2)]. sPD-1 and sPD-L2 are mainly produced by alternative splicing isoforms of PD-1 mRNA, while sPD-L1 is produced by matrix metalloproteinases (MMPs) cutting membrane-bound programmed cell death-ligand 1 (mPD-L1). sPD-1 and sPD-Ls play an important role in autoimmune regulation via blocking the mPD-1 /mPD-L1 pathway, while connective tissue disease (CTD) is a kind of disease caused by autoimmune reaction, and abnormal function of mPD-1/mPD-L1 can occur in the occurrence and development of many autoimmune diseases. Therefore, sPD-1 and sPD-Ls play an important role in the pathogenesis of CTD caused by autoimmune reaction via blocking the mPD-1 /mPD-L1 pathway. It is of great practical significance to understand clinical value of sPD-1 and sPD-Ls in various CTDs for improving the quality of life of patients and the underlying mechanism.

The effect of PD-1/PD-L1 signaling axis on the interaction between CD19+B cells and CD4+T cells in peripheral blood of patients with systemic lupus erythematosus

Abstract Background The defect of B cell self-tolerance and the continuous antigen presentation by T cells (TCs) mediated by autoreactive B cells (BCs) play a key role in the occurrence and development of systemic lupus erythematosus (SLE). PD-1/PD-L1 signaling axis negatively regulates the immune response of TCs after activation and maintains immune tolerance. However, the effect of PD-1/PD-L1 signaling axis on the interaction between CD19+B/CD4+TCs in the peripheral blood of patients with SLE has not been studied in detail. Methods PD-1/PD-L1 and Ki-67 levels in peripheral blood (PB) of 50 SLE patients and 41 healthy controls (HCs) were detected through flow cytometry, and then the expression of PD-1+/−cells and PD-L1+/−cells Ki-67 was further analyzed. CD19+B/CD4+TCs were separated for cell culture and the supernatant was collected to determine proliferation and differentiation of TCs. IL-10 and IFN-γ secretion in the supernatant was also determined using ELISA. Results The PD-1, PD-L1, and Ki-67 levels on CD19+B/CD4+TCs in patients with SLE were higher than HCs. In CD19+B/CD4+TCs of SLE patients, the proliferative activity of PD-L1+ cells was higher than that of PD-L1− cells, and the proliferative activity of PD-1+ cells was higher than that of PD-1− cells. In the system co-culturing CD19+B/CD4+TCs from HCs/SLE patients, activated BCs promoted TCs proliferation and PD-L1 expression among TCs. Addition of anti-PD-L1 to co-culture system restored the proliferation of TCs, and inhibited IL-10/IFN-γ level. The addition of anti-PD-L1 to co-culture system also restored Tfh and downregulated Treg in HCs. Conclusions Axis of PD-1/PD-L1 on CD19+B/CD4+TCs in PB of SLE patients is abnormal, and cell proliferation is abnormal. In CD19+B/CD4+TCs of SLE patients, the proliferative activity of PD-L1+ and PD-1+ cells compared with PD-L1− and PD-1− cells in SLE patients, respectively. CD19+B/CD4+TCs in SLE patients can interact through PD-1/PD-L1.

Correlation between peripheral blood lymphocyte subpopulations and primary systemic lupus erythematosus.

This study explored the correlation between peripheral blood CD3＋, CD3＋/CD4＋, CD3+/CD8+, CD4＋/CD8＋, CD3-/CD16+ CD56+, and CD3-CD19+ and disease activity of different subtypes of systemic lupus erythematosus (SLE). The percentages of CD3+, CD3+/CD4+, CD3+/CD8+, CD4+/CD8+, CD3-/CD16+ CD56+, and CD3-CD19+ in the peripheral blood of patients (n = 80) classified into lupus nephritis, blood involvement, and joint involvement and SLE in different active stages were detected by flow cytometry. Their correlations with baseline clinical experimental indicators of SLE patients' SLE disease activity index score (SLEDAI) and complement C3 were analyzed. The results showed that CD3+, CD3+/CD4+, and CD3+/CD8+ at baseline level were negatively correlated with SLEDAI scores. These were positively correlated with C3. In conclusion, T-lymphocyte subpopulations are closely related to SLE activity and can be used as reference indicators to evaluate the SLE activity.

Identification of key interferon-stimulated genes for indicating the condition of patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with highly heterogeneous clinical symptoms and severity. There is complex pathogenesis of SLE, one of which is IFNs overproduction and downstream IFN-stimulated genes (ISGs) upregulation. Identifying the key ISGs differentially expressed in peripheral blood mononuclear cells (PBMCs) of patients with SLE and healthy people could help to further understand the role of the IFN pathway in SLE and discover potential diagnostic biomarkers. The differentially expressed ISGs (DEISG) in PBMCs of SLE patients and healthy persons were screened from two datasets of the Gene Expression Omnibus (GEO) database. A total of 67 DEISGs, including 6 long noncoding RNAs (lncRNAs) and 61 messenger RNAs (mRNAs) were identified by the "DESeq2" R package. According to Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, those DEISGs were mainly concentrated in the response to virus and immune system processes. Protein-protein interaction (PPI) network showed that most of these DEISGs could interact strongly with each other. Then, IFIT1, RSAD2, IFIT3, USP18, ISG15, OASL, MX1, OAS2, OAS3, and IFI44 were considered to be hub ISGs in SLE by "MCODE" and "Cytohubba" plugins of Cytoscape, Moreover, the results of expression correlation suggested that 3 lncRNAs (NRIR, FAM225A, and LY6E-DT) were closely related to the IFN pathway. The lncRNA NRIR and mRNAs (RSAD2, USP18, IFI44, and ISG15) were selected as candidate ISGs for verification. RT-qPCR results showed that PBMCs from SLE patients had substantially higher expression levels of 5 ISGs compared to healthy controls (HCs). Additionally, statistical analyses revealed that the expression levels of these ISGs were strongly associated to various clinical symptoms, including thrombocytopenia and facial erythema, as well as laboratory indications, including the white blood cell (WBC) count and levels of autoantibodies. The Receiver Operating Characteristic (ROC) curve demonstrated that the IFI44, USP18, RSAD2, and IFN score had good diagnostic capabilities of SLE. According to our study, SLE was associated with ISGs including NRIR, RSAD2, USP18, IFI44, and ISG15, which may contribute to the future diagnosis and new personalized targeted therapies.

Patients with systemic lupus erythematosus show increased proportions of CD19+CD20- B cells and secretion of related autoantibodies.

BACKGROUND: At present, anti-CD20 monoclonal antibody treatments targeting systemic lupus erythematosus (SLE) are complex, variable, and often have disappointing outcomes. High levels of programmed cell death-1 (PD-1) and its ligands (PD-L1, PD-L2) or CD80/CD86 on B cell surfaces are markers of increased B cell activity. However, their expression levels on CD19+CD20+/- B cells and their clinical significance for SLE dynamics have not been carefully investigated. METHODS: Flow cytometry was used to detect the expression levels of PD-1, PD-L1, PD-L2, CD80, and CD86 on CD19+CD20+/- B cells in peripheral blood from SLE patients and healthy controls (HCs). The amount of anti-dsDNA and immunoglobin G (IgG) secreted by CD19+CD20+/- B cells was measured by enzyme-linked immunosorbent assay. RESULTS: CD19+CD20- B cell frequency was significantly higher in SLE patients than in HCs (P < 0.001), and was positively correlated with disease activity. In SLE patients, frequencies of PD-1, PD-L1, PD-L2, and CD86 on CD19+CD20- B cells were significantly higher than CD19+CD20+ B cells (P ≤ 0.002) and were significantly correlated with individual laboratory and clinically based parameters (P < 0.05). In vitro tests, we found that the levels of anti-dsDNA and IgG secreted by CD19+CD20- B cells from patients with SLE were significantly higher than the HC group (P < 0.05). CONCLUSIONS: We found abnormal frequency of CD19+CD20- B cells and increased expression of surface markers on these cells from SLE patients. And the CD19+CD20- B cells had the ability to proliferate and secrete anti-dsDNA and IgG. Additionally, our results suggested that CD19+CD20- B cells from SLE patients may be the activated B cells and caused poor efficacy of rituximab. Key Points • CD19+CD20- B cell frequencies were significantly higher in SLE patients. • Frequencies of PD-1 and its ligands on CD19+CD20- B cells increased significantly in SLE patients. • CD19+CD20- B cells in SLE patients had the ability to secrete anti-dsDNA and IgG. • CD19+CD20- B cells in SLE patients may be the activated B cells and caused poor efficacy of rituximab.

MiR-let-7d-3p regulates IL-17 expression through targeting AKT1/mTOR signaling in CD4+ T cells.

The aberrant expression of interleukin-17 (IL-17) has been reported in the pathogenesis of autoimmune diseases, such as primary Sjögren's syndrome (pSS). However, the detailed mechanism remains poorly understood. We aim to characterize the expression of IL-17 in pSS and analyze the detailed underlying mechanism. IL-17 and microRNA miR-let-7d-3p expression were assayed by quantitative real-time PCR and Western blot, and proliferation-related protein expression was measured by Western blot. Luciferase reporter assays were performed to detect the direct regulation of IL-17 by miR-let-7d-3p. Expression of miR-let-7d-3p was negatively correlated with the expression of IL-17 in patients with pSS. Besides, the AKT1/mTOR signaling pathway was found critical for miR-let-7d-3p-mediated IL-17 expression. Furthermore, miR-let-7d-3p targeted AKT1 to bridge the regulation of IL-17. Finally, we verified AKT1 co-expression could rescue IL-17 downregulation caused by miR-let-7d-3p. Our study revealed novel mechanism that how did IL-17 was exactly modulated by miR-let-7d-3p and the potential of miR-let-7d-3p-AKT1-mTOR-IL-17 signaling as therapeutic targets for autoimmune diseases.

[T follicular helper cells and their related molecules in rheumatoid arthritis: A review].

Abnormal T follicular helper (Tfh) cells in patients with rheumatoid arthritis (RA) is related to the occurrence and development of RA. At present, the mechanism of Tfh cells regulating RA is still unclear. In addition, Tfh cell surface molecules C-X-C motif chemokine receptor 5 (CXCR5), inducible costimulatory molecule (ICOS) and programmed death factor 1 (PD-1) and its secreted interleukin 21 (IL-21), B-cell lymphoma 6 (BCL6) have been shown to be involved in the development of RA. We mainly reviewied the mechanism of RA regulation from the perspective of Tfh cell surface molecules and their secreted factors, analyzed the effects of various molecules related to Tfh cells on RA, and explored the significance of each molecule in the clinical diagnosis of RA and the potential ways of treating RA with each molecule as a target.

[IgG4-related diseases: A comprehensive review].

IgG4-related disease (IgG4-RD) is an inflammatory disorder with slow progression in multiple organs, characterized by abundant infiltration of IgG4-positive plasmacytes and fibrosis in the involved organs. The precise pathogenic mechanism of IgG4-RD still remains unclear. Currently, the abnormal regulation of acquired immunity and adaptive immunity is considered as the main pathogenesis of IgG4-RD, and its clinical manifestations are diverse. IgG4-RD can affect any tissue and organ. Inflammatory pseudotumor and diffuse enlargement are the common manifestations, which are easily misdiagnosed as tumor or inflammation. The treatment of glucocorticoid-based drugs is effective. However, the symptoms of IgG4-RD are variable and the prognosis is poor. We mainly summarized the research progress in the pathogenesis, clinical features, diagnosis and treatment of IgG4-RD.

Berberine attenuates arthritis in adjuvant-induced arthritic rats associated with regulating polarization of macrophages through AMPK/NF-кB pathway.

Berberine (BBR) is a traditional folk medicine with excellent anti-inflammatory properties. This study aimed to investigate the anti-arthritic effects of BBR in adjuvant arthritis (AA) in rats and its regulatory role in the polarization of macrophages. Rats were immunized with Complete Freund's Adjuvant (CFA), and then BBR (40, 80, 160 mg/kg) was administered orally for 14 days. BBR significantly reduced paw swelling and arthritis global assessment as well as alleviated joint destruction and inflammatory cell infiltration. The index of the thymus and thymocyte proliferation were significantly reduced by BBR. Moreover, BBR treatment restrained the phagocytic function of macrophages and restored the balance of M1/M2 by reducing the levels of M1 cytokines (tumour necrosis factor-α, interleukin-1ß, and interleukin-6), increasing the levels of M2 cytokines (interleukin-10 and transforming growth factor-ß1), increasing the expression of arginase 1(Arg1) (M2 marker) and decreasing the expression of inducible nitric oxide synthase (iNOS) (M1 marker). BBR also downregulated the ratio of Th17/Treg cells. Further research on the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/nuclear factor κB (NF-κB) pathway found that BBR upregulated the activity of AMPK, while it downregulated the expression of phospho-RelA (p-p65), phospho-NF-kappa-B inhibitor alpha (p-IκBα) and cyclooxygenase (COX)-2. Therefore, our findings suggest BBR has significantly therapeutic effects in AA rats by regulating the polarization of macrophages through the AMPK/NF-кB pathway.

The role and clinical significance of programmed cell death- ligand 1 expressed on CD19+B-cells and subsets in systemic lupus erythematosus.

BACKGROUND: Programmed cell death-1 (PD-1) and programmed death-ligand 1 (PD-L1)-targeted therapies have enhanced T-cell response and demonstrated efficacy in the treatment of multiple cancers. However, the role and clinical significance of PD-L1 expression on CD19+ B-cells and their subsets, with particular reference to systemic lupus erythematosus (SLE), have not yet been studied in detail. OBJECTIVE: The present study aimed to investigate PD-L1 expression on CD19+ B-cells and their subsets, in addition to exploring its possible role in Tfh-cell activation and B-cell differentiation in SLE. METHODS: Frequencies of CD19+ B-cells, their subsets, PD-L1 and Tfh cells in the peripheral blood of SLE patients and healthy controls (HCs) were determined using cytometry. The clinical data of SLE patients were recorded in detail, and the correlation between their laboratory parameters, clinical parameters and disease activity indices was statistically analyzed. CD19+PD-L1+B-cells and CD19+PD-L1- B-cells were sorted and cultured with a stimulant, following which the supernatants were collected for immunoglobulin G and anti-double stranded DNA detection via enzyme-linked immunosorbent assay. RESULTS: In SLE patients, CD19+B-cells and partial subgroups were enriched in peripheral blood. Also, the observed increase in the frequency of CD19+PD-L1+B-cells was significantly associated with a higher disease activity index. An in vitro culture test demonstrated that the amounts of anti-dsDNA and immunoglobulin G secreted by the CD19+PD-L1+B-cells of SLE patients and HCs were vastly different. In addition, a strong correlation existed between the frequencies of CD19+PD-L1+B-cells and defined Tfh cells of SLE patients. CONCLUSION: This study demonstrated that the expression of CD19+PD-L1+B-cells in the peripheral blood of SLE patients was abnormal, and that disease-related laboratory parameters and clinical indicators were correlated. CD19+PD-L1+B-cells were enriched and played a critical role in activating the pathogenic T-cell and B-cell responses in patients with SLE.

Corrigendum: The Role of Estrogen Membrane Receptor (G Protein-Coupled Estrogen Receptor 1) in Skin Inflammation Induced by Systemic Lupus Erythematosus Serum IgG.

[This corrects the article DOI: 10.3389/fimmu.2017.01723.].

Role of Hepatic Deposited Immunoglobulin G in the Pathogenesis of Liver Damage in Systemic Lupus Erythematosus.

The onset of hepatic disorders in patients with systemic lupus erythematosus (SLE) is frequent; however, the etiology and liver pathogenesis of SLE remain unknown. In the present study, the role of hepatic deposited immunoglobulin G (IgG) in SLE-derived liver damage was investigated. From a retrospective analysis of the medical records of 404 patients with lupus and from experimental studies on mice models, we found that liver dysfunction is common in SLE and liver damage with IgG deposition spontaneously develops in lupus-prone mice. Liver injury was recreated in mice by injecting IgG from lupus serum intrahepatically. The inflammation intensity in the liver decreased with IgG depletion and the lupus IgG-induced liver inflammation in FcγRIII-deficient mice was comparatively low; while, inflammation was increased in FcγRIIb-deficient mice. Macrophages, Kupffer cells, natural killer cells, and their products, but not lymphocytes, are required for the initiation of SLE-associated liver inflammation. Blocking IgG signaling using a spleen tyrosine kinase (Syk) inhibitor suppressed the liver damage. Our findings provided evidence of spontaneously established liver damage in SLE. They also suggested that hepatic-deposited lupus IgG is an important pathological factor in the development of liver injury and that hepatic inflammation is regulated by the Syk signaling pathway. Thus, Syk inhibition might promote the development of a therapeutic strategy to control liver damage in patients with SLE.

[The Study of Protective Effect of Paeoniflorin on Lung Injury in MRL/lpr Mice].

OBJECTIVE: To investigate the protective effects of paeoniflorin on the lung injury in systemic lupus erythematosus with mouse model. METHODS: Ten wild type mice and 40 MRL/lpr mice were used in this study. MRL/lpr mice were randomly assigned to MRL/lpr group,MRL/lpr + dexamethasone (1.5 mg/kg) group,MRL/lpr + paeoniflorin (20 mg/kg) group,and MRL/lpr + paeoniflorin (40 mg/kg). The levels of malondialdehyde (MDA) , superoxide dismutase (SOD) ,catalase (CAT) ,glutathione peroxidase (GSH-Px) in serum were detected. The serum levesl of inflammatory cytokines were measured. Lung pathological changes were determined by HE staining. The protein level of phospho-phosphatidylinositol-3 kinase (P-PI3K),phospho-serine-threonine kinase B(P-Akt) ,phospho-nuclear factor kappa B (P-NF-κB),phospho-inhibitor of nuclear factor kappa Bα (P-IκBα) were detected by Western blot. RESULTS: Paeoniflorin decreased serum level of MDA and increased the levels of SOD,CAT,GSH-PX,and decreased the levels of inflammatory cytokines. Paeoniflorin improved lung pathological changes and inhibited the protein levels of P-PI3K,P-Akt,P-NF-κBp65,and P-IκBα in the lung tissue of MRL/lpr mice. CONCLUSION: Paeoniflorin may be beneficial for the prevention of lung injury in systemic lupus erythematosus.