Aberrant H3K4me3 modification of immune response genes in CD4+ T cells of patients with systemic lupus erythematosus.

BACKGROUND: Increasing evidence has highlighted the significant role of histone modifications in pathogenesis of systemic lupus erythematosus (SLE). However, few studies have comprehensively analyzed trimethylation of histone H3 lysine 4 (H3K4me3) features at specific immune gene loci in SLE patients. METHODS: We conducted H3K4me3 chromatin immunoprecipitation sequencing (ChIP-seq) on CD4+ T cells from SLE patients and healthy controls (HC). Differential H3K4me3 peaks were identified, followed by enrichment analysis. We integrated online RNA-seq and DNA methylation datasets to explore the relationship between H3K4me3 modification, DNA methylation and gene expression. We validated several upregulated peak regions by ChIP-qPCR and confirmed their impact on gene expression using RT-qPCR. Finally, we investigated the impact of H3K4 methyltransferases KMT2A on the expression of immune response genes. RESULTS: we identified 147 downregulated and 2701 upregulated H3K4me3 peaks in CD4+ T cells of SLE. The upregulated peaks primarily classified as gained peaks and enriched in immune response genes such as FCGR2A, C5AR1, SERPING1 and OASL. Genes with upregulated H3K4me3 and downregulated DNA methylations in the promoter were highly expressed in SLE patients. These genes, including OAS1, IFI27 and IFI44L, were enriched in immune response pathways. The IFI44L locus also showed increased H3K27ac modification, chromatin accessibility and chromatin interactions in SLE. Moreover, knockdown of KMT2A can downregulate the expression of immune response genes in T cells. CONCLUSION: Our study uncovers dysregulated H3K4me3 modification patterns in immune response genes loci, which also exhibit downregulated DNA methylation and higher mRNA expression in CD4+ T cells of SLE patients.

The transcription factor ZEB2 drives the formation of age-associated B cells.

Age-associated B cells (ABCs) accumulate during infection, aging, and autoimmunity, contributing to lupus pathogenesis. In this study, we screened for transcription factors driving ABC formation and found that zinc finger E-box binding homeobox 2 (ZEB2) is required for human and mouse ABC differentiation in vitro. ABCs are reduced in ZEB2 haploinsufficient individuals and in mice lacking Zeb2 in B cells. In mice with toll-like receptor 7 (TLR7)-driven lupus, ZEB2 is essential for ABC formation and autoimmune pathology. ZEB2 binds to +20-kb myocyte enhancer factor 2b (Mef2b)'s intronic enhancer, repressing MEF2B-mediated germinal center B cell differentiation and promoting ABC formation. ZEB2 also targets genes important for ABC specification and function, including Itgax. ZEB2-driven ABC differentiation requires JAK-STAT (Janus kinase-signal transducer and activator of transcription), and treatment with JAK1/3 inhibitor reduces ABC accumulation in autoimmune mice and patients. Thus, ZEB2 emerges as a driver of B cell autoimmunity.

CircPTPN22 modulates T-cell activation by sponging miR-4689 to regulate S1PR1 expression in patients with systemic lupus erythematosus.

BACKGROUND: Circular RNAs are involved in autoimmune disease pathogenesis. Our previous study indicated that circPTPN22 is involved in autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis, but the underlying mechanisms remain unclear. METHODS: First, the expression of circPTPN22 was detected by real-time PCR and western blotting. After overexpression or knockdown of circPTPN22, the proliferation of Jurkat cells was detected by the CCK-8 assay, and the apoptosis of Jurkat cells was detected by flow cytometry. In addition, the relationship between circPTPN22-miR-4689-S1PR1 was confirmed by bioinformatic analyses, fluorescence in situ hybridization assays, RNA-binding protein immunoprecipitation, and dual luciferase reporter assays. RESULTS: We found that circPTPN22 expression was downregulated in the PBMCs of SLE patients compared to those of healthy controls. Overexpression of circPTPN22 increased proliferation and inhibited apoptosis of Jurkat T cells, whereas knockdown of circPTPN22 exerted the opposite effects. CircPTPN22 acts as a miR-4689 sponge, and S1PR1 is a direct target of miR-4689. Importantly, the circPTPN22/miR-4689/S1PR1 axis inhibited the secretion of TNF-α and IL-6 in Jurkat T cells. CONCLUSIONS: CircPTPN22 acts as a miR-4689 sponge to regulate T-cell activation by targeting S1PR1, providing a novel mechanism for the pathogenesis of SLE.

Impaired dynamic X-chromosome inactivation maintenance in T cells is a feature of spontaneous murine SLE that is exacerbated in female-biased models.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a highly female-biased systemic autoimmune disease, but the molecular basis for this female bias remains incompletely elucidated. B and T lymphocytes from patients with SLE and female-biased mouse models of SLE exhibit features of epigenetic dysregulation on the X chromosome which may contribute to this strong female bias. We therefore examined the fidelity of dynamic X-chromosome inactivation maintenance (dXCIm) in the pathogenesis of two murine models of spontaneous lupus-NZM2328 and MRL/lpr-with disparate levels of female-bias to determine whether impaired dXCIm contributes to the female bias of disease. METHODS: CD23+ B cells and CD3+ T cells were purified from age-matched C57BL/6 (B6), MRL/lpr, and NZM2328 male and female mice, activated in vitro, and processed for Xist RNA fluorescence in situ hybridization, H3K27me3 immunofluorescence imaging, qPCR, and RNA sequencing analyses. RESULTS: The dynamic relocalization of Xist RNA and the canonical heterochromatin mark, H3K27me3, to the inactive X chromosome was preserved in CD23+ B cells, but impaired in activated CD3+ T cells from the MRL/lpr model (p < 0.01 vs. B6), and even more impaired in the heavily female-biased NZM2328 model (p < 0.001 vs. B6; p < 0.05 vs. MRL/lpr). RNAseq of activated T cells from NZM2328 mice revealed the female-biased upregulation of 32 X-linked genes distributed broadly across the X chromosome, many of which have roles in immune function. Many genes encoding Xist RNA-interacting proteins were also differentially expressed and predominantly downregulated, which may account for the observed mislocalization of Xist RNA to the inactive X chromosome. CONCLUSIONS: Although evident in T cells from both the MRL/lpr and NZM2328 models of spontaneous SLE, impaired dXCIm is more severe in the heavily female-biased NZM2328 model. The aberrant X-linked gene dosage in female NZM2328 mice may contribute towards the development of female-biased immune responses in SLE-prone hosts. These findings provide important insights into the epigenetic mechanisms contributing to female-biased autoimmunity.

Incident racial discrimination predicts elevated C-Reactive protein in the Black Women's experiences Living with Lupus (BeWELL) study.

INTRODUCTION: Racial discrimination is a distinct health threat that increases disease risk among Black Americans. Psychosocial stress may compromise health through inflammatory mechanisms. This study examines incident experiences of racial discrimination and changes in the inflammatory biomarker C-reactive protein (CRP) over a two-year period among Black women with systemic lupus erythematosus (SLE)-an inflammatory autoimmune disease sensitive to psychosocial stress and characterized by stark racial inequities in outcomes. METHODS: Data are from the Black Women's Experiences Living with Lupus (BeWELL) Study. Participants (n = 380) from metropolitan Atlanta, Georgia were enrolled from April 2015 to May 2017. Incident racial discrimination was assessed bi-annually via self-report using the Experiences of Discrimination measure. CRP was assessed annually over a two-year period. Latent change score analyses modeled longitudinal within-person associations between incident racial discrimination and change in log-transformed CRP from baseline to Year 2. RESULTS: Incident experiences of racial discrimination were associated with elevated log-CRP across the two-year study period (b = 0.039, SE = 0.017, 95% CI: 0.006, 0.071). For each domain of incident racial discrimination experienced, CRP increased 3.98%. CONCLUSION: This study contributes to growing evidence on the biological consequences of racism and is the first to document an association between incident racial discrimination and changes in inflammation among Black women with SLE. Racial inequities in SLE outcomes and other diseases driven by inflammatory pathways may be explained in part through experiences of racial discrimination.

Increased Serum Interleukin 10 Levels Are Associated with Increased Disease Activity and Increased Risk of Anti-SS-A/Ro Antibody Positivity in Patients with Systemic Lupus Erythematosus.

Interleukin 10 (IL-10) plays a role in inflammation and cell-type responses. The anti-SS-A/Ro antibody contributes to leucopenia, and cutaneous and neonatal lupus. OBJECTIVES: To evaluate the association between serum IL-10 levels and autoantibodies, disease activity and organ involvement in systemic lupus erythematosus (SLE) patients. PATIENTS AND METHODS: We studied 200 SLE patients and 50 controls. We analyzed organ involvement, disease activity, serum IL-10 and interleukin-6 (IL-6) levels, and antinuclear and antiphospholipid antibody profiles. RESULTS: Serum IL-10 and IL-6 levels were higher in SLE patients than in controls (all p < 0.00001). Serum IL-10 levels were positively correlated with IL-6 (p < 0.00001), CRP (p < 0.00001), fibrinogen (p = 0.003), and ESR (p < 0.00001), and negatively correlated with hemoglobin (p = 0.0004) and lymphocytes (p = 0.01). Serum IL-6 levels were positively correlated with CRP (p < 0.00001), fibrinogen (p = 0.001), and ESR (p < 0.00001); and negatively correlated with hemoglobin (p = 0.008) and lymphocytes (p = 0.03). Elevated serum IL-10 levels were associated with an increased risk of anti-SS-A/Ro antibody positivity (p = 0.03). Elevated serum IL-6 levels were associated with an increased risk of heart (p = 0.007) and lung (p = 0.04) involvement. CONCLUSIONS: In SLE patients, increased serum IL-10 levels were associated with increased disease activity and risk of anti-SS-A/Ro antibody positivity.

Current Progress in Treating Systemic Lupus Erythematosus Using Exosomes/MicroRNAs.

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease associated with impaired organ functions that can seriously affect the daily life of patients. Recent SLE therapies frequently elicit adverse reactions and side effects in patients, and clinical heterogeneity is considerable. Mesenchymal stromal cells (MSCs) have anti-inflammatory, tissue repair, and immunomodulatory properties. Their ability to treat autoimmune diseases largely depends on secreted extracellular vesicles, especially exosomes. The effects of exosomes and microRNAs (miRNAs) on SLE have recently attracted interest. This review summarizes the applications of MSCs derived from bone marrow, adipocyte tissue, umbilical cord, synovial membrane, and gingival tissue, as well as exosomes to treating SLE and the key roles of miRNAs. The efficacy of MSCs infusion in SLE patients with impaired autologous MSCs are reviewed, and the potential of exosomes and their contents as drug delivery vectors for treating SLE and other autoimmune diseases in the future are briefly described.

The Role of B Cell and T Cell Glycosylation in Systemic Lupus Erythematosus.

Glycosylation is a post-translational modification that affects the stability, structure, antigenicity and charge of proteins. In the immune system, glycosylation is involved in the regulation of ligand-receptor interactions, such as in B-cell and T-cell activating receptors. Alterations in glycosylation have been described in several autoimmune diseases, such as systemic lupus erythematosus (SLE), in which alterations have been found mainly in the glycosylation of B lymphocytes, T lymphocytes and immunoglobulins. In immunoglobulin G of lupus patients, a decrease in galactosylation, sialylation, and nucleotide fucose, as well as an increase in the N-acetylglucosamine bisector, are observed. These changes in glycoisolation affect the interactions of immunoglobulins with Fc receptors and are associated with pericarditis, proteinuria, nephritis, and the presence of antinuclear antibodies. In T cells, alterations have been described in the glycosylation of receptors involved in activation, such as the T cell receptor; these changes affect the affinity with their ligands and modulate the binding to endogenous lectins such as galectins. In T cells from lupus patients, a decrease in galectin 1 binding is observed, which could favor activation and reduce apoptosis. Furthermore, these alterations in glycosylation correlate with disease activity and clinical manifestations, and thus have potential use as biomarkers. In this review, we summarize findings on glycosylation alterations in SLE and how they relate to immune system defects and their clinical manifestations.

ANA-specific antibodies, ANA patterns, anti-ds-DNA results, and clinical diagnosis: a laboratory and clinical audit.

The diagnosis of systemic autoimmune diseases (SAID) is challenging, due to overlapping features with other non-immune disorders. Anti-nuclear antibodies (ANA)/anti-cellular antibodies are the sensitive screening tests but anti-double-stranded-deoxyribonucleic acid-antibody (anti-ds-DNA) and ANA-specific antibodies are specific for SAID. We aimed to look at ANA-specific antibodies in our patients and correlated them with ANA patterns, anti-ds-DNA, and clinical diagnosis for proper interpretation and better patient management cost-effectively. A retrospective data analysis of 641 patients was done (1st of February 2019 to 31st of July 2021) who were tested for ANA-specific antibodies at the Immunology Department of Indus Hospital and Health Network. ANA and anti-ds-DNA results and clinical diagnosis were also analyzed for ANA-specific antibody-positive patients. Descriptive data were presented in mean ± standard deviation and frequency percentages whereas inferential data were analyzed with a chi-square test for association between ANA-specific antibodies status, ANA, anti-ds-DNA, and clinical features. ANA-specific antibodies test revealed positivity for at least one autoantibody in 245 (38.2%) patients. Of these, ANA was tested in 206 patients reactive for ANA-specific antibodies and found positive in 195 (95%) as compared to negative (< 0.001). Speckled and homogenous were predominant ANA patterns in ANA-specific antibody-positives (56% and 42% respectively). Multiple ANA patterns were found in 18 patients most commonly with systemic lupus erythematosus (SLE) and mixed connective tissue disorder (MCTD). Anti-SSA were the most common ANA-specific antibodies (50%) and were mostly found in sera with speckled (61/97) and homogenous (38/97) patterns and associated mostly with SLE (48%) and Sjogren's syndrome (86%). Among ANA-negative patients, anti-SSA were the most common antibodies (n = 5). Anti-ds-DNA was found in 66% of SLE patients along with another ANA-specific antibody. This study showed that testing for ANA-specific antibodies cannot be gated on ANA patterns. Also, there is a redundancy of these antibodies with various clinical diagnoses. Moreover, they are useful in making a diagnosis in ANA-negative patients as well with clinical suspicion.

LncRNA IL21-AS1 interacts with hnRNPU protein to promote IL21 overexpression and aberrant differentiation of Tfh cells in systemic lupus erythematosus.

BACKGROUND: The aberrant differentiation of T follicular helper (Tfh) cells plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanism of regulating Tfh cells differentiation remains unclear. Long noncoding RNAs (lncRNAs) act as important regulators in the processes of innate and adaptive immune response. Whether lncRNAs are involved in regulating Tfh cell differentiation and autoimmune responses need to be further identified. METHODS: The characters and functions of human IL21-AS1 and its mouse homologous lncRNA (mIl21-AS) were investigated by a series of biochemical assays and cell transfection assay. mIl21-AS1 regulating humoral immune response in vivo was explored by keyhole limpet haemocyanin (KLH) and chronic graft versus host disease (cGVHD) model. RESULTS: Human IL21-AS1 and its mouse homologous lncRNA (mIl21-AS) were identified and cloned. We uncovered that IL21-AS1 was highly expressed in CD4+ T cells of SLE patients and Tfh cells, which promoted differentiation of Tfh cells. Mechanistically, IL21-AS1 bound heterogeneous nuclear ribonucleoprotein U and recruited acetyltransferases CREB-binding protein to the promoter of IL21, leading to the transcriptional activation of IL21 and Tfh cells differentiation through increasing Histone H3 acetylation level on IL21 promoter. Moreover, Tfh proportion and antibodies production were significantly increased in mIl21-AS knock-in mice immunized with KLH. mIl21-AS1 overexpression also exacerbated the lupus-like phenotype in cGVHD mice model. CONCLUSIONS: Our results demonstrate that IL21-AS1 activates IL21 transcription via epigenetic mechanism to promote germinal centre response, adding insight into the molecular regulation of autoimmune pathogenesis and providing a novel target for SLE treatment.

Evaluation of anifrolumab safety in systemic lupus erythematosus: A meta-analysis and systematic review.

Objectives: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, and type I interferon plays an important role in its pathogenesis. Anifrolumab is a new strategy for the treatment of systemic lupus erythematosus. It could antagonize the activity of all type 1 interferons by binding with type I interferon receptor subunit 1. The aim of our study was to evaluate the safety of anifrolumab in patients with moderate to severe SLE (excluding patients with active severe lupus nephritis or central nervous system lupus). Methods: Four databases (Embase, Cochrane, PubMed, Web of Science) were systematically searched from inception until December 2021 for randomized controlled trials (RCTs) evaluating the safety of anifrolumab versus placebo in SLE patients. Then, the incidence of adverse events in each study was aggregated using meta-analysis. Results: A total of 1160 SLE patients from four RCTs were included in the analysis. Serious adverse events were less common in the anifrolumab group than in the placebo group (RR: 0.76, 95% CI: 0.59-0.98, p<0.03). The most common adverse events included upper respiratory tract infection (RR: 1.48, 95% CI: 1.13-1.94, P=0.004), nasopharyngitis (RR: 1.66, 95% CI: 1.25-2.20, P=0.0004), bronchitis (RR: 1.96, 95% CI: 1.32-2.92, P=0.0009), and herpes zoster (RR: 3.40, 95% CI: 1.90-6.07, P<0.0001). Conclusion: Anifrolumab is considered a well-tolerated option for the treatment of SLE patients with good safety. Systematic Review Registration: https://inplasy.com, identifier 202230054.

Decreased Jumonji Domain-Containing 3 at the Promoter Downregulates Hematopoietic Progenitor Kinase 1 Expression and Cytoactivity of T Follicular Helper Cells from Systemic Lupus Erythematosus Patients.

T follicular helper (Tfh) cells are overactivated in systemic lupus erythematosus (SLE) patients and contribute to excessive immunity. Hematopoietic progenitor kinase 1 (HPK1), as an inhibitor of T cells, is underexpressed in SLE Tfh cells and consequently induces autoimmunity. However, the reason for downregulation of HPK1 in SLE Tfh cells remains elusive. By combining chromatin immunoprecipitation with quantitative polymerase chain reaction assays, it was found that histone H3 lysine 27 trimethylation (H3K27me3) at the HPK1 promoter in SLE Tfh cells elevated greatly. We also confirmed jumonji domain-containing 3 (JMJD3) binding at the HPK1 promoter in SLE Tfh cells reduced profoundly. Knocking down JMJD3 in normal Tfh cells with siRNA alleviated enrichments of JMJD3, H3K4me3, and mixed-lineage leukemia (MLL) 1 at the HPK1 promoter and increased H3K27me3 number in the region. HPK1 expression was lowered, while Tfh cell proliferation activity, IL-21 and IFNγ secretions in the supernatants of Tfh cells, and IgG1 and IgG3 concentrations in the supernatants of Tfh-B cell cocultures all upregulated markedly. In contrast, elevating JMJD3 amount in SLE Tfh cells by JMJD3-overexpressed plasmid showed opposite effects. The abundances of H3K4me3 and MLL1 at the HPK1 promoter in SLE Tfh cells were greatly attenuated. Our results suggest that deficient JMJD3 binding at the promoter dampens HPK1 expression in SLE Tfh cells, thus making Tfh cells overactive, and ultimately results in onset of SLE.

MX2: Identification and systematic mechanistic analysis of a novel immune-related biomarker for systemic lupus erythematosus.

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multiple organs. However, the current SLE-related biomarkers still lack sufficient sensitivity, specificity and predictive power for clinical application. Thus, it is significant to explore new immune-related biomarkers for SLE diagnosis and development. Methods: We obtained seven SLE gene expression profile microarrays (GSE121239/11907/81622/65391/100163/45291/49454) from the GEO database. First, differentially expressed genes (DEGs) were screened using GEO2R, and SLE biomarkers were screened by performing WGCNA, Random Forest, SVM-REF, correlation with SLEDAI and differential gene analysis. Receiver operating characteristic curves (ROCs) and AUC values were used to determine the clinical value. The expression level of the biomarker was verified by RT‒qPCR. Subsequently, functional enrichment analysis was utilized to identify biomarker-associated pathways. ssGSEA, CIBERSORT, xCell and ImmuCellAI algorithms were applied to calculate the sample immune cell infiltration abundance. Single-cell data were analyzed for gene expression specificity in immune cells. Finally, the transcriptional regulatory network of the biomarker was constructed, and the corresponding therapeutic drugs were predicted. Results: Multiple algorithms were screened together for a unique marker gene, MX2, and expression analysis of multiple datasets revealed that MX2 was highly expressed in SLE compared to the normal group (all P < 0.05), with the same trend validated by RT‒qPCR (P = 0.026). Functional enrichment analysis identified the main pathway of MX2 promotion in SLE as the NOD-like receptor signaling pathway (NES=2.492, P < 0.001, etc.). Immuno-infiltration analysis showed that MX2 was closely associated with neutrophils, and single-cell and transcriptomic data revealed that MX2 was specifically expressed in neutrophils. The NOD-like receptor signaling pathway was also remarkably correlated with neutrophils (r >0.3, P < 0.001, etc.). Most of the MX2-related interacting proteins were associated with SLE, and potential transcription factors of MX2 and its related genes were also significantly associated with the immune response. Conclusion: Our study found that MX2 can serve as an immune-related biomarker for predicting the diagnosis and disease activity of SLE. It activates the NOD-like receptor signaling pathway and promotes neutrophil infiltration to aggravate SLE.

Sex-based comparison of CD4+ T cell DNA methylation in lupus reveals proinflammatory epigenetic changes in men.

Systemic lupus erythematosus (SLE) is more common in women than men, but the disease is more severe when it affects men. Lupus CD4+ T cells demonstrate dysregulated DNA methylation patterns. The purpose of this study was to investigate genome-wide CD4+ T cell differential DNA methylation between men (n = 12) and women (n = 10) with SLE. DNA methylation was evaluated using the Infinium MethylationEPIC array, and differences between male versus female SLE patients were calculated with probe-wise linear regressions with adjustment for age and disease activity. We identified 198 hypomethylated and 108 hypermethylated CpG sites in CD4+ T cells isolated from male compared to female SLE patients, annotated to 201 and 102 genes, respectively. A great proportion of these genes were related to apoptosis and immune functions. Among differentially methylated genes, CASP10, which is involved in the extrinsic apoptotic pathway, and multiple genes involved in T cell function and differentiation such as ELAVL1, UHRF1, and SMAD2, were hypomethylated in men compared to women with SLE. Importantly, network analysis of differentially methylated genes revealed a pattern consistent with increased activation of ROCK, PP2A, PI3K, and ERK1/ERK2 in men compared to women with SLE. These data provide epigenetic evidence suggesting activation of key T cell pathways in men compared to women with SLE and shed new light into possible mechanisms underlying increased SLE disease severity in men.

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.

Cell activation, PD-1 expression and in vitro cytokine production in patients with juvenile systemic lupus erythematosus.

BACKGROUND: Juvenile systemic lupus erythematosus (jSLE) is known to be more severe and with a higher frequency of renal and central nervous system impairment when compared to systemic lupus erythematosus in adults. The study of immunological characteristics of jSLE patients might help to envisage better treatment strategies to reduce the burden of the disease. OBJECTIVE: To characterize peripheral lymphocytes, assessing activation markers, and PD-1 expression on T cells; to evaluate in vitro cytokine expression upon stimulation in jSLE patients and age-matched controls. METHODOLOGY: Eighteen jSLE patients on low disease activity and 25 matched healthy adolescents were evaluated for immune activation and PD-1 expression on peripheral blood lymphocytes by flow cytometry. Twenty-one cytokines were assessed by X-MAP technology after in vitro stimulation of peripheral blood with phytohemagglutinin. RESULTS: jSLE patients had lower numbers of CD4 T, CD8 T, B, and NK cells; higher central memory CD8 T cell percentages were noted in jSLE adolescents in comparison with controls (p = 0.014). B cells subsets showed a higher percentage of exhausted memory subset than controls (p = 0.014). The expression of PD-1 on CD4 T and CD8 T cells did not show relevant changes in jSLE adolescents. After stimulation of peripheral blood, cell supernatant of jSLE patients showed a trend to lower concentrations of IL-10 (p=0.080) and higher concentrations of IL-23 (p = 0.063) than controls. CONCLUSIONS: jSLE patients on low disease activity maintain lymphopenia of all subsets, with a B cell profile of exhaustion. Upon in vitro stimulation, peripheral blood cell supernatant showed a shift to IL-23, suggesting a role of inhibitors of this cytokine as another potential therapeutic target for those patients.

ALKBH5 Expression could Affect the Function of T Cells in Systemic Lupus Erythematosus Patients: A Case-control Study.

BACKGROUND: N6-methyladenosine (m6A) modification is widespread in eukaryotic mRNA, regulated by m6A demethylase, AlkB homolog 5 (ALKBH5). However, the role of m6A in systemic lupus erythematosus (SLE) is still obscure. We explored ALKBH5 expression in SLE patients and its effects on T cells. METHODS: 100 SLE patients and 110 healthy controls were recruited to investigate the expression of ALKBH5 in peripheral blood mononuclear cells (PBMCs). An additional 32 SLE patients and 32 health controls were enrolled to explore the expression of ALKBH5 in T cells. Then we explored the function of ALKBH5 in T cells by lentivirus. RESULTS: The expressions of ALKBH5 were downregulated in both PBMCs and T cells in SLE patients (all P<0.05). In PBMCs: ALKBH5 mRNA levels were associated with a complement C4 level in plasma (P<0.05). In T cells: ALKBH5 mRNA levels were downregulated in SLE patients with low complement levels, high antidsDNA, anti-Sm, anti-RNP, and proteinuria compared with those without, respectively (all P<0.05); ALKBH5 mRNA levels were negatively related with SLE disease activity index score, erythrocyte sedimentation rate, and anti-dsDNA levels (all P<0.05), and positively correlated with complement C3 and C4 level (all P<0.05). Functionally, the overexpression of ALKBH5 promoted apoptosis and inhibited the proliferation of T cells (all P<0.05). CONCLUSION: ALKBH5 expression is downregulated in SLE patients and could affect the apoptosis and proliferation of T cells, but the exact mechanism still needs to be further explored.