Serum BLC/CXCL13 concentrations and renal expression of CXCL13/CXCR5 in patients with systemic lupus erythematosus and lupus nephritis

Moesin deficiency leads to lupus-like nephritis with accumulation of CXCL13-producing patrolling monocytes

Moesin is a member of the ezrin-radixin-moesin (ERM) family of proteins that link plasma membrane proteins to the cortical cytoskeleton and thus regulate diverse cellular processes. Mutations in the human moesin gene cause a primary immunodeficiency called X-linked moesin-associated immunodeficiency (X-MAID), which may be complicated by an autoimmune phenotype with kidney involvement. We previously reported that moesin-deficient mice exhibit lymphopenia similar to that of X-MAID and develop a lupus-like autoimmune phenotype with age. However, the mechanism through which moesin defects cause kidney pathology remains obscure. Here, we characterized immune cell infiltration and chemokine expression in the kidney of moesin-deficient mice. We found accumulation of CD4+ T and CD11b+ myeloid cells and high expression of CXCL13, whose upregulation was detected before the onset of overt nephritis. CD4+ T cell population contained IFN-γ-producing effectors and expressed the CXCL13 receptor CXCR5. Among myeloid cells, Ly6Clo patrolling monocytes and MHCIIlo macrophages markedly accumulated in moesin-deficient kidneys and expressed high CXCL13 levels, implicating the CXCL13-CXCR5 axis in nephritis development. Functionally, Ly6Clo monocytes from moesin-deficient mice showed reduced migration toward sphingosine 1-phosphate. These findings suggest that moesin plays a role in regulating patrolling monocyte homeostasis, and that its defects lead to nephritis associated with accumulation of CXCL13-producing monocytes and macrophages.

Myasthenia gravis and five autoimmune diseases: a bidirectional Mendelian randomization study

BACKGROUND

The association between myasthenia gravis (MG) and other autoimmune diseases is well established. In this study, we aimed to investigate the causal effects between MG and five other autoimmune diseases, including autoimmune thyroid disease (AITD), multiple sclerosis (MS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and type 1 diabetes (T1DM).

METHODS

We conducted a bidirectional Mendelian randomization (MR) study by using seven published genome-wide association studies (GWAS), including MG (1873 patients versus 36,370 controls), AITD (autoimmune hypothyroidism) (22,997 patients versus 175,475 controls), AITD (autoimmune hyperthyroidism) (962 patients versus 172,976 controls), MS (47,429 patients versus 68,374 controls), RA (14,361 patients versus 43,923 controls), SLE (4222 patients versus 8431 controls), and T1DM (9266 patients versus 15,574 controls). We used the inverse-variance-weighted (IVW) method, weighted-median (WM) estimator, MR-Egger regression, and MR PRESSO in our analyses. We also carried out detailed sensitivity analyses for each direction using the aforementioned methods.

RESULTS

When MG was treated as the exposure, MR evidence suggested a causal relationship between MG and T1DM, SLE, AITD (both hypothyroidism and hyperthyroidism), and MS (excluding RA). Using the IVW method, we found that MG was associated with increased risk of T1DM (OR = 1.94; 95% CI, 1.16-3.26; p = 0.012), SLE (OR = 1.47; 95% CI, 1.02-2.13; p = 0.04), AITD (hypothyroidism) (OR = 1.31; 95% CI, 1.02-1.68; p = 0.039), AITD (hyperthyroidism) (OR = 1.55; 95% CI, 1.15-2.09; p = 0.004), and MS (OR = 1.46; 95% CI, 1.01-2.09; p = 0.041). When MG was treated as the outcome, MR evidence suggested that RA, T1DM, and SLE were causal factors in MG. Using the IVW method, we found that the risk of MG increased with exposure to RA (OR = 1.21; 95% CI, 1.08-1.37; p = 0.002), T1DM (OR = 1.09; 95% CI, 1.02-1.16; p = 0.006), and SLE (OR = 1.12; 95% CI, 1.02-1.23; p = 0.018).

CONCLUSIONS

This study demonstrated a causal relationship between MG and several other autoimmune diseases. Our results supported a bidirectional causal association between MG and SLE/T1DM. Our findings also provided reliable evidence that MG is associated with increased risk of AITD. Meanwhile, we also showed that RA is a possible causal driver of MG risk.

Noninvasive biomarkers for lupus nephritis

Lupus nephritis (LN) is one of the most severe clinical manifestations of systemic lupus erythematosus (SLE). Notably, the clinical manifestations of LN are not always consistent with the histopathological findings. Therefore, the diagnosis and activity monitoring of this disease are challenging and largely depend on invasive renal biopsy. Renal biopsy has side effects and is associated with the risk of bleeding and infection. There is a growing interest in the development of novel noninvasive biomarkers for LN. In this review, we summarize most of the LN biomarkers discovered so far by correlating current knowledge with future perspectives. These biomarkers fundamentally reflect the biological processes of kidney damage and repair during disease. Furthermore, this review highlights the role of urinary cell phenotype detection in the diagnosis, monitoring, and treatment of LN and summarizes the limitations and countermeasures of this test.

BAFFR expression in circulating T follicular helper (CD4+CXCR5+PD-1+) and T peripheral helper (CD4+CXCR5-PD-1+) cells in systemic lupus erythematosus

BACKGROUND

Circulating T follicular helper (cTfh) and T peripheral helper (Tph) subpopulations are shown to be higher in systemic lupus erythematosus (SLE) patients and have been involved in promoting extrafollicular B cell responses. However, a possible association with the B cell activating factor (BAFF), a cytokine mainly related to B cell responses and disease activity in SLE, has not been investigated. Therefore, this study aimed to evaluate the association of cTfh and Tph subpopulations with the BAFF system expression and clinical activity in SLE patients.

METHODS

This study included 43 SLE patients and 12 healthy subjects (HS). The identification of cTfh (CD4+CXCR5+PD-1+), Tph (CD4+CXCR5-PD-1+) cells, expression of membrane-bound BAFF (mBAFF), BAFFR, TACI, BCMA, and intracellular IL-21 was performed by flow cytometry. Serum levels of IL-21, CXCL13, and BAFF were analyzed using ELISA. The SLEDAI-2K score was used to evaluate disease activity in SLE patients.

RESULTS

Compared with HS, SLE patients showed a significantly increased percentage of cTfh and Tph cells, higher in patients with clearly active disease. SLE patients had markedly higher IL-21-producing cTfh and Tph cells than HS. Both subpopulations were positively correlated with the disease activity in SLE patients. Tph cells were negatively correlated with CD19+CXCR5+ B cells and positively correlated with CD19+CXCR5- B cells. A low expression of mBAFF and their receptors TACI and BCMA was found on cTfh and Tph cells in SLE patients and HS. However, SLE patients with clearly active disease showed decreased expression of BAFFR on cTfh and Tph subpopulations than patients with mildly active/nonactive disease. Serum IL-21, CXCL13, and BAFF levels were higher in SLE patients than in HS. Levels of CXCL13 were correlated with disease activity. Non-significant correlations were observed among T cell subpopulations and IL-21, CXCL13, and BAFF levels.

CONCLUSIONS

This study emphasizes the importance of cTfh and Tph cells in SLE pathogenesis. Besides the importance of IL-21, our results suggest that BAFFR could play a role in cTfh and Tph subpopulations in the autoimmunity context.

Decipher the Immunopathological Mechanisms and Set Up Potential Therapeutic Strategies for Patients with Lupus Nephritis

Lupus nephritis (LN) is one of the most severe complications in patients with systemic lupus erythematosus (SLE). Traditionally, LN is regarded as an immune complex (IC) deposition disease led by dsDNA-anti-dsDNA-complement interactions in the subendothelial and/or subepithelial basement membrane of glomeruli to cause inflammation. The activated complements in the IC act as chemoattractants to chemically attract both innate and adaptive immune cells to the kidney tissues, causing inflammatory reactions. However, recent investigations have unveiled that not only the infiltrating immune-related cells, but resident kidney cells, including glomerular mesangial cells, podocytes, macrophage-like cells, tubular epithelial cells and endothelial cells, may also actively participate in the inflammatory and immunological reactions in the kidney. Furthermore, the adaptive immune cells that are infiltrated are genetically restricted to autoimmune predilection. The autoantibodies commonly found in SLE, including anti-dsDNA, are cross-reacting with not only a broad spectrum of chromatin substances, but also extracellular matrix components, including α-actinin, annexin II, laminin, collagen III and IV, and heparan sulfate proteoglycan. Besides, the glycosylation on the Fab portion of IgG anti-dsDNA antibodies can also affect the pathogenic properties of the autoantibodies in that α-2,6-sialylation alleviates, whereas fucosylation aggravates their nephritogenic activity. Some of the coexisting autoantibodies, including anti-cardiolipin, anti-C1q, anti-ribosomal P autoantibodies, may also enhance the pathogenic role of anti-dsDNA antibodies. In clinical practice, the identification of useful biomarkers for diagnosing, monitoring, and following up on LN is quite important for its treatments. The development of a more specific therapeutic strategy to target the pathogenic factors of LN is also critical. We will discuss these issues in detail in the present article.

Long non-coding RNA maternally expressed gene 3, miR-125a-5p, CXCL13, and NF-kB in patients with immune thrombocytopenia

The main aim of this study was to assess the expression level of circulating long non-coding RNA maternally expressed gene 3 (lncRNA-MEG3), microRNA (miR-125a-5P), the chemokine C-X-C motif ligand13 (CXCL13), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) in immune thrombocytopenia (ITP) cases and to study its relation to the disease severity and treatment response. This case-control study included 45 patients newly diagnosed as ITP and 45 healthy subjects. We assessed complete blood count, antinuclear antibodies, hepatitis B and C virus serology, lncRNA-MEG3, miR-125a-5P, and CXCL13 expression in serum by real-time PCR and NF-kb protein by ELISA. In ITP patients compared to control, lncRNA-MEG3 was significantly increased, and miRNA-125a-5P was decreased, and this was associated with higher CXCL13 and NF-kB levels (P < 0.001, for all).There was a significant negative correlation between platelet count and lncRNA-MEG3, CXCL13, and NF-kb, while a positive correlation with miR-125a-5p in ITP patients. Patients who responded to steroids had significantly higher miR-125a-5p (P = 0.016) and significantly lower lncRNA-MEG3 (P < 0.001), CXCL13 (P = 0.005), and NF-kb (p = 0.002). Based on the ROC curves, lncRNA-MEG3 displayed the highest area under the curve (AUC) in the identification of organ bleeding (AUC = 0.805), the response to steroids (AUC = 0.853), and the need for splenectomy (AUC = 0.75).

Transcription factor Fli-1 impacts the expression of CXCL13 and regulates immune cell infiltration into the kidney in MRL/lpr mouse

OBJECTIVE

Friend leukaemia virus integration 1 (Fli-1) regulates chemokine/cytokine expression and thus plays an important role in the development of lupus nephritis. Chemokine CXC ligand 13 (CXCL13) is a chemokine that promotes the formation of ectopic lymphoid structures and has been reported to be associated with the pathogenesis of lupus nephritis. The relationship between Fli-1 and CXCL13 is unknown. This study aims to elucidate whether Fli-1 impacts CXCL13 expression and contributes to the progression of lupus-like nephritis in adult MRL/lpr mouse.

METHODS

Serum CXCL13 levels were measured in adult wild-type (WT) MRL/lpr mice and Fli-1 heterozygote knockout (Fli-1^+/-) MRL/lpr mice (4 months old or older) using ELISA. Renal mRNA expression (CXCL13 and related molecules) was measured using real-time PCR method. Kidneys were removed, stained and evaluated using a pathology scoring system. The grade of CXCL13 or CXC-chemokine receptor type 5 (CXCR5)-positive immune cell infiltration into the kidney was evaluated using immunostaining with anti-CXCL13 or anti-CXCR5 antibodies. We also used immunofluorescence staining with CXCL13- and CD11b-specific antibodies to detect the infiltration of CXCL13/CD11b double-positive immune cells.

RESULTS

Serum CXCL13 levels in Fli-1^+/- MRL/lpr mice were significantly lower than that in WT MRL/lpr mice (545.5 and 960.5 pg/mL, p=0.02). Renal expression of CXCL13 mRNA and SRY-related HMG box4 (Sox4) (an important factor for B-cell development) levels were significantly lower in Fli-1^+/- MRL/lpr mice. Renal histology scores in WT MRL/lpr mice revealed significantly increased glomerular inflammation. Despite similar interstitial immune cell infiltration into the kidney, the number of CXCL13- and CXCR5-positive cells was significantly lower in Fli-1^+/- MRL/lpr mice than in WT mice. Furthermore, immunofluorescence staining revealed that Fli-1^+/-MRL/lpr mice had significantly fewer CXCL13/CD11b double-positive immune cells.

CONCLUSION

Fli-1 regulates renal Sox4 mRNA expression and infiltration of CXCR5-positive cells as well as CXCL13/CD11b double-positive immune cells into the kidney, which affects CXCL13 expression and lupus-like nephritis.

CXCL13-CXCR5 axis: Regulation in inflammatory diseases and cancer

Chemokine C-X-C motif ligand 13 (CXCL13), originally identified as a B-cell chemokine, plays an important role in the immune system. The interaction between CXCL13 and its receptor, the G-protein coupled receptor (GPCR) CXCR5, builds a signaling network that regulates not only normal organisms but also the development of many diseases. However, the precise action mechanism remains unclear. In this review, we discussed the functional mechanisms of the CXCL13-CXCR5 axis under normal conditions, with special focus on its association with diseases. For certain refractory diseases, we emphasize the diagnostic and therapeutic role of CXCL13-CXCR5 axis.

The CXCL13/CXCR5 Immune Axis in Health and Disease—Implications for Intrathecal B Cell Activities in Neuroinflammation

The chemokine C-X-C- ligand 13 (CXCL13) is a major B cell chemoattractant to B cell follicles in secondary lymphoid organs (SLO) that proposedly recruits B cells to the cerebrospinal fluid (CSF) during neuroinflammation. CXCR5, the cognate receptor of CXCL13, is expressed on B cells and certain T cell subsets, in particular T follicular helper cells (Tfh cells), enabling them to follow CXCL13 gradients towards B cell follicles for spatial proximity, a prerequisite for productive T cell–B cell interaction. Tfh cells are essential contributors to B cell proliferation, differentiation, and high-affinity antibody synthesis and are required for germinal center formation and maintenance. Circulating Tfh cells (cTfh) have been observed in the peripheral blood and CSF. Furthermore, CXCL13/CXCR5-associated immune activities organize and shape adaptive B cell-related immune responses outside of SLO via the formation of ectopic lymphoid structures in inflamed tissues, including the central nervous system (CNS). This review summarizes the recent advances in our understanding of the CXCL13/CXCR5 immune axis and its role in vaccination, autoimmunity, and infection with a special focus on its relevance for intrathecal B cell activities in inflammatory CNS diseases.

Efficiency of Disease and Disease Activity Diagnosis Models of Systemic Lupus Erythematosus Based on Protein Array Analysis

Background

Systemic lupus erythematosus (SLE) has become increasingly common in the clinic and requires complicated evidence of both clinical manifestations and laboratory examinations. Additionally, the assessment and monitoring of lupus disease activity are challenging. We hope to find efficient biomarkers and establish diagnostic models of SLE.

Materials and Methods

We detected and quantified 40 proteins using a quantitative protein array of 76 SLE patients and 21 healthy controls, and differentially expressed proteins were screened out by volcano plot. Logistic regression analysis was used to recognize biomarkers that could be enrolled in the disease diagnosis model and disease activity diagnosis model, and a receiver operating characteristic (ROC) curve was drawn to evaluate the efficiency of the model. A nomogram was depicted for convenient and visualized application of our models in the clinic. Decision curves and clinical impact curves were also plotted to validate our models.

Results

The protein levels of TNF RII, BLC, TNF RI, MIP-1b, eotaxin, MIG, MCSF, IL-8, MCP-1, and IL-10 showed significant differences between patients with SLE and healthy controls. TNF RII and MIP-1b were included in the SLE diagnosis model with logistic regression analysis, and the value of the area under the ROC curve (AUC) was 0.914 (95% confidence interval (CI), 0.859-0.969). TNF RII, BLC, and MIP-1b were enrolled in the disease activity diagnosis model, and the AUC value was 0.823 (95% CI 0.729-0.916). Both of the models that we established showed high efficiency. Additionally, the three protein biomarkers contained in the disease activity distinguish model provided additional benefit to conventional biomarkers in predicting active lupus.

Conclusions

The disease diagnosis model and disease activity diagnosis model that we developed based on protein array chip results showed high efficiency in differentiating patients with SLE from healthy controls and recognizing SLE patients with high disease activity, and they have also been validated. This implied that they might greatly benefit clinical decisions and the treatment of SLE.

CD11c+ T-bet+ CD21hi B Cells Are Negatively Associated With Renal Impairment in Systemic Lupus Erythematosus and Act as a Marker for Nephritis Remission

Lupus nephritis (LN) is one of the most common manifestations of systemic lupus erythematosus (SLE), characterized by abnormal B cell activation and differentiation to memory or plasma effector cells. However, the role of these cells in the pathogenesis of LN is not fully understood, as well as the effect of induction therapy on B cell subsets, possibly associated with this manifestation, like aged-associated B cells (ABCs). Consequently, we analyzed the molecules defining the ABCs subpopulation (CD11c, T-bet, and CD21) through flow cytometry of blood samples from patients with lupus presenting or not LN, following up a small sub-cohort after six months of induction therapy. The frequency of ABCs resulted higher in LN patients compared to healthy subjects. Unexpectedly, we identified a robust reduction of a CD21^hi subset that was almost specific to LN patients. Moreover, several clinical and laboratory lupus features showed strong and significant correlations with this undefined B cell subpopulation. Finally, it was observed that the induction therapy affected not only the frequencies of ABCs and CD21^hi subsets but also the phenotype of the CD21^hi subset that expressed a higher density of CXCR5. Collectively, our results suggest that ABCs, and more importantly the CD21^hi subset, may work to assess therapeutic response since the reduced frequency of CD21^hi cells could be associated with the onset of LN.

Role of the CXCL13/CXCR5 Axis in Autoimmune Diseases

CXCL13 is a B-cell chemokine produced mainly by mesenchymal lymphoid tissue organizer cells, follicular dendritic cells, and human T follicular helper cells. By binding to its receptor, CXCR5, CXCL13 plays an important role in lymphoid neogenesis, lymphoid organization, and immune responses. Recent studies have found that CXCL13 and its receptor CXCR5 are implicated in the pathogenesis of several autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, primary Sjögren’s syndrome, myasthenia gravis, and inflammatory bowel disease. In this review, we discuss the biological features of CXCL13 and CXCR5 and the recent findings on the pathogenic roles of the CXCL13/CXCR5 axis in autoimmune diseases. Furthermore, we discuss the potential role of CXCL13 as a disease biomarker and therapeutic target in autoimmune diseases.

Circulating C-X-C Motif Ligand 13 as a Biomarker for Early Predicting Efficacy of Subcutaneous Immunotherapy in Children With Chronic Allergic Rhinitis

BACKGROUND

C-X-C motif ligand 13 (CXCL13) and B cell-activating factor (BAFF) are proven to be involved in inflammatory diseases, but their role in allergic rhinitis (AR) remains unclear. The aim of this study was to investigate the role of serum CXCL13 and BAFF in AR and their clinical values as objective biomarkers to predict the efficacy of subcutaneous immunotherapy (SCIT).

METHODS

We prospectively recruited 90 children with AR treated with SCIT and collected their serum specimens before SCIT. One-year follow-up was conducted for all patients, and they were categorized into effective and ineffective groups based on efficacy. The serum concentrations of CXCL13 and BAFF were detected and compared between the two groups. A validation cohort of 52 responders and 26 non-responders were further assessed for both cytokines and serum CXCL13 and BAFF levels were assayed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Eighty children completed the follow-up schedule, and 56 children were categorized into the effective group and 24 children into the ineffective group. The serum levels of CXCL13 in the effective group were clearly higher than those in the ineffective group (P < 0.05). Receiver operating characteristic (ROC) curves revealed the potential values of CXCL13 as a biomarker in predicting the response of SCIT. Further, in the validation cohort, ELISA results demonstrated that serum CXCL13 levels were increased in responders than non-responders (P < 0.05). ROC curves showed good accuracy of serum CXCL13 in predicting the efficacy of SCIT.

CONCLUSION

Our discovery-validation study demonstrated that circulating CXCL13 might serve as a novel biomarker to predict the outcome of SCIT in childhood AR. The findings indicated that CXCL13 was involved in the pathological mechanisms of AR and made help to the fundamental therapeutic mechanism of SCIT.

CXCL13 Neutralization Attenuates Neuropsychiatric Manifestations in Lupus-Prone Mice

Neuropsychiatric lupus (NPSLE), the nervous system presentation of systemic lupus erythematosus (SLE), remains challenging to treat due to its unclear pathogenesis and lack of available targeted therapies. A potential contributor to disease progression is brain tertiary lymphoid structures (TLS); these ectopic lymphoid follicles that can develop tissue-targeted antibodies have recently been described in the MRL/lpr lupus mouse strain, a classic model for studying NPSLE. The brains of MRL/lpr mice show a significant increase of CXCL13, an important chemokine in lymphoid follicle formation and retention that may also play a role in the disease progression of NPSLE. The aim of the present study was to inhibit CXCL13 and examine the effect of this intervention on lymphoid formation and the development of neurobehavioral manifestations in lupus mice. Female MRL/lpr mice were injected with an anti-CXCL13 antibody, an IgG1 isotype-matched antibody, or PBS either three times a week for 12 weeks intraperitoneally (IP) starting at 6-8 weeks of age, or continuously intracerebroventricularly (ICV) with an osmotic pump over a two-week period starting at 15 weeks of age. Cognitive dysfunction and depression-like behavior were assessed at the end of treatment. When treatment was delivered IP, anti-CXCL13 treated mice showed significant improvement in cognitive function when compared to control treated mice. Depression-like behavior was attenuated as well. Furthermore, mice that received anti-CXCL13 by the ICV route showed similar beneficial effects. However, the extent of lymphocyte infiltration into the brain and the general composition of the aggregates were not substantively changed by anti-CXCL13 irrespective of the mode of administration. Nevertheless, analysis of brain gene expression in anti-CXCL13 treated mice showed significant differences in key immunological and neuro-inflammatory pathways that most likely explained the improvement in the behavioral phenotype. Our results indicate that CXCL13 affects the behavioral manifestations in the MRL/lpr strain and is important to the pathogenesis of murine NPSLE, suggesting it as a potential therapeutic target.

An interactive single cell web portal identifies gene and cell networks in COVID-19 host responses

Numerous studies have provided single-cell transcriptome profiles of host responses to SARS-CoV-2 infection. Critically lacking however is a data mine that allows users to compare and explore cell profiles to gain insights and develop new hypotheses. To accomplish this, we harmonized datasets from COVID-19 and other control condition blood, bronchoalveolar lavage, and tissue samples, and derived a compendium of gene signature modules per cell type, subtype, clinical condition, and compartment. We demonstrate approaches to interacting with, exploring, and functional evaluating these modules via a new interactive web portal ToppCell (http://toppcell.cchmc.org/). As examples, we develop three hypotheses: (1) alternatively-differentiated monocyte-derived macrophages form a multicelllar signaling cascade that drives T cell recruitment and activation; (2) COVID-19-generated platelet subtypes exhibit dramatically altered potential to adhere, coagulate, and thrombose; and (3) extrafollicular B maturation is driven by a multilineage cell activation network that expresses an ensemble of genes strongly associated with risk for developing post-viral autoimmunity.

Serum, but Not Saliva, CXCL13 Levels Associate With Infiltrating CXCL13+ Cells in the Minor Salivary Gland Lesions and Other Histologic Parameters in Patients With Sjögren's Syndrome

Recent studies suggest that elevated CXCL13 serum levels in patients with primary Sjögren’s syndrome (pSS) associate with minor salivary gland (MSG) histologic features, disease severity, as well as high-risk status for non-Hodgkin lymphoma (NHL) development and NHL itself. In contrast, limited discriminative value of CXCL13 saliva levels has been reported. Prompt by these reports, we sought to validate the clinical utility of CXCL13 by investigating potential correlations of serum and saliva levels with MSG histopathologic [including CXCL13+-cell number, severity of infiltrates and germinal center (GC) formation], serologic and clinical parameters, as well as NHL. CXCL13 levels were evaluated in paired serum and saliva specimens of 45 pSS patients (15 with NHL; pSS-associated NHL: SSL), 11 sicca-controls (sicca-complaining individuals with negative MSG biopsy and negative autoantibody profile), 10 healthy individuals (healthy-controls) and 6 non-SS-NHLs. CXCL13+-cells were measured in paired MSG-tissues of 22 of pSS patients studied (including 7 SSLs) and all sicca-controls. CXCL13 serum levels were significantly increased in pSS and SSL patients compared to sicca- and healthy-controls and were positively correlated with the CXCL13+-cell number and biopsy focus-score. Serum CXCL13 was significantly higher in pSS patients with GCs, rheumatoid factor, hypocomplementemia, high disease activity, NHL and in high-risk patients for NHL development. CXCL13 saliva levels were significantly increased in SSL patients (compared to non-SS-NHLs), patients with GCs and in high-risk for NHL patients. Univariate analysis revealed that CXCL13 serum, but not saliva, levels were associated with lymphoma, an association that did not survive multivariate analysis. Conclusively, our findings confirm that serum, but not saliva, levels of CXCL13 are associated with histologic, serologic and clinical features indicative of more severe pSS.

Association of the CXCL9-CXCR3 and CXCL13-CXCR5 axes with B-cell trafficking in giant cell arteritis and polymyalgia rheumatica

OBJECTIVE

B-cells are present in the inflamed arteries of giant cell arteritis (GCA) patients and a disturbed B-cell homeostasis is reported in peripheral blood of both GCA and the overlapping disease polymyalgia rheumatica (PMR). In this study, we aimed to investigate chemokine-chemokine receptor axes governing the migration of B-cells in GCA and PMR.

METHODS

We performed Luminex screening assay for serum levels of B-cell related chemokines in treatment-naïve GCA (n = 41), PMR (n = 31) and age- and sex matched healthy controls (HC, n = 34). Expression of chemokine receptors on circulating B-cell subsets were investigated by flow cytometry. Immunohistochemistry was performed on GCA temporal artery (n = 14) and aorta (n = 10) and on atherosclerosis aorta (n = 10) tissue.

RESULTS

The chemokines CXCL9 and CXCL13 were significantly increased in the circulation of treatment-naïve GCA and PMR patients. CXCL13 increased even further after three months of glucocorticoid treatment. At baseline CXCL13 correlated with disease activity markers. Peripheral CXCR3+ and CXCR5+ switched memory B-cells were significantly reduced in both patient groups and correlated inversely with their complementary chemokines CXCL9 and CXCL13. At the arterial lesions in GCA, CXCR3+ and CXCR5+ B-cells were observed in areas with high CXCL9 and CXCL13 expression.

CONCLUSION

Changes in systemic and local chemokine and chemokine receptor pathways related to B-cell migration were observed in GCA and PMR mainly in the CXCL9-CXCR3 and CXCL13-CXCR5 axes. These changes can contribute to homing and organization of B-cells in the vessel wall and provide further evidence for an active involvement of B-cells in GCA and PMR.

Implicating Gene and Cell Networks Responsible for Differential COVID-19 Host Responses via an Interactive Single Cell Web Portal

Numerous studies have provided single-cell transcriptome profiles of host responses to SARS-CoV-2 infection. Critically lacking however is a datamine that allows users to compare and explore cell profiles to gain insights and develop new hypotheses. To accomplish this, we harmonized datasets from COVID-19 and other control condition blood, bronchoalveolar lavage, and tissue samples, and derived a compendium of gene signature modules per cell type, subtype, clinical condition, and compartment. We demonstrate approaches to probe these via a new interactive web portal (http://toppcell.cchmc.org/COVID-19). As examples, we develop three hypotheses: (1) a multicellular signaling cascade among alternatively differentiated monocyte-derived macrophages whose tasks include T cell recruitment and activation; (2) novel platelet subtypes with drastically modulated expression of genes responsible for adhesion, coagulation and thrombosis; and (3) a multilineage cell activator network able to drive extrafollicular B maturation via an ensemble of genes strongly associated with risk for developing post-viral autoimmunity.

The CXCL13 chemokine serves as a potential biomarker to diagnose systemic lupus erythematosus with disease activity

The aim of our study was to assess the regulatory response of the chemokine CXCL13 in the serum of systemic lupus erythematosus (SLE) patients with disease activity and to evaluate its influence on the inflammatory process in SLE. Serum samples from 97 SLE patients, 49 non-SLE patients (23 patients with other autoimmune diseases and 26 patients with rheumatoid arthritis) and 50 healthy controls were analyzed for the concentration of CXCL13 using ELISA. The results indicated that the serum levels of CXCL13 were significantly higher in SLE patients than in non-SLE patients and healthy controls (p < 0.001). Moreover, the level of CXCL13 decreased as the level of anti-dsDNA IgG decreased after treatment between the anti-dsDNA-positive SLE patients and the anti-dsDNA-negative SLE patients. In addition, serum CXCL13 levels were correlated with SLEDAI in different activities of SLE, renal involvement and active LN. Furthermore, the level of CXCL13 was positively related to the SLEDAI, level of anti-dsDNA IgG, level of ESR and RAI of high-avidity IgG ANAs (HA IgG ANAs). Additionally, statically analysis revealed that CXCL13 would be a best diagnostic value for determining the disease activity of SLE due to its moderate sensitivity (93.5%), specificity (95%), PPV (98.6%), NPV (79.2%) and OR(95%CI,250(30.303-1000)), at a cut-off level of 15.27 pg/mL. First, we indicated that CXCL13 was elevated in SLE patients regardless of the presence or absence of anti-dsDNA IgG ANAs. Furthermore, HA IgG ANAs might affect the circulation of CXCL13. Therefore, the chemokine CXCL13 might be a risk factor influencing the inflammatory process in SLE.

Frontiers of Autoantibodies in Autoimmune Disorders: Crosstalk Between Tfh/Tfr and Regulatory B Cells

Balance of Tfh/Tfr cell is critically important for the maintenance of immune tolerance, as evidenced by the fact that T follicular helper (Tfh) cells are central to the autoantibodies generation through providing necessary help for germinal center (GC) B cells, whereas T follicular regulatory (Tfr) cells significantly inhibit autoimmune inflammation process through restraining Tfh cell responses. However, signals underlying the regulation of Tfh and Tfr cells are largely undefined. Regulatory B cells (Bregs) is a heterogeneous subpopulation of B cells with immunosuppressive function. Considerable advances have been made in their functions to produce anti‐inflammatory cytokines and to regulate Th17, Th1, and Treg cells in autoimmune diseases. The recent identification of their correlations with dysregulated Tfr/Tfh cells and autoantibody production makes Bregs an important checkpoint in GC response. Bregs exert profound impacts on the differentiation, function, and distribution of Tfh and Tfr cells in the immune microenvironment. Thus, unraveling mechanistic information on Tfh-Breg and Tfr-Breg interactions will inspire novel implications for the establishment of homeostasis and prevention of autoantibodies in diverse diseases. This review summarizes the dysregulation of Tfh/Tfr cells in autoimmune diseases with a focus on the emerging role of Bregs in regulating the balance between Tfh and Tfr cells. The previously unsuspected crosstalk between Bregs and Tfh/Tfr cells will be beneficial to understand the cellular mechanisms of autoantibody production and evoke a revolution in immunotherapy for autoimmune diseases.

Immunologic responses to antifibrotic treatment in IPF patients

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease limited to the lungs. Immunological dysregulation may significantly participate in the pathophysiology of IPF. The immunological responses to nintedanib therapy in IPF patients were investigated for the first time in this study.

MATERIALS AND METHODS

Fifty IPF patients (median age (IQR) 69 (65-75) years; 38 males), were selected retrospectively. Flowcytometry analysis were performed to phenotype immunological biomarkers in peripheral blood from IPF patients after 1 year of antifibrotic therapy and a group of healthy volunteers.

RESULTS

Before starting antifibrotic treatment, IPF patients showed increased CD1d+CD5+ (p = 0.0460), Treg (p = 0.0354), T effector (CD25^highCD127^high) (p = 0.0336), central cells (CD4⁺CD45RA^-) (p = 0.0354), effector cells (CD4⁺CD45RA⁺) (p = 0.0249) and follicular cell percentages (p = 0.0006), notably Tfh1 (p = 0.0412) and Tfh17 (p = 0.0051) cell percentages, in respect with healthy controls (HC). After nintedanib therapy, Breg (p = 0.0302), T effector (p = 0.0468), Th17.1 (p = 0.0146) and follicular cells (p = 0.0006), notably Tfh1 (p = 0.0006) and Tfh17 (p = 0.0182) cell percentages, were significantly decreased. In the logistic regression, Tfh panel showed a significant area under the receiver operating characteristics curve (AUROC) to distinguish IPF than HC (90.5%), as well as t0 and t1 (99.3%).

CONCLUSION

In conclusion, the immunological results obtained in this study demonstrate that nintedanib significantly helps to restore immunological responses in IPF patients. These findings will be useful in the search for biomarkers predictive of response to antifibrotic treatment.

Immunotherapies application in active stage of systemic lupus erythematosus in pregnancy: A case report and review of literature

BACKGROUND

Pregnancy in the setting of systemic lupus erythematosus can worsen the condition from the stable to active stage, with quality of life and fertility desire being particular concerns. Pregnancy in the active stage of systemic lupus erythematosus (ASLE), although rare and complicated to manage, can be treated favorably with immunotherapies ifs used properly. Here we report such a success case.

CASE SUMMARY

A 31-year-old primigravida patient, diagnosed with SLE seven years ago, was induced ASLE after a cold at 21 + weeks. The patient’s vital signs on presentation were normal. Her laboratory exam was remarkable for significant proteinuria, liver and renal dysfunction, and low C3 and C4 levels. Infectious work-up was negative. The patient was diagnosed with ASLE. She was given immunosuppressive agents (methylprednisolone, gamma globulin and azathioprine etc.) and plasma adsorption therapy, monitoring blood pressure every 8 h, fetal heart rate twice a day, and liver and renal function at least twice a week. Successful maternal and fetal outcomes are presented here.

CONCLUSION

Child-bearing in ASLE has become more promising, even for this difficult case of ASLE with multiple organ damage. Thorough antepartum counseling, cautious maternal-fetal monitoring, and multi-organ function monitoring by multidisciplinary specialties are keys to favorable pregnancy outcomes.

Regulation of mRNA stability by RBPs and noncoding RNAs contributing to the pathogenicity of Th17 cells

Th17 cells remain one of the most important subsets of T cells in numerous autoimmune and chronic inflammatory diseases. Posttranscriptional regulation (PTR), especially mRNA stability, has recently emerged as an important mechanism that controls the fate of Th17 cells. This review summarizes the current knowledge on RNA-binding proteins (RBPs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) that induce mRNA stability changes and their roles in mediating the differentiation, proliferation, function, and migration of Th17 cells. In addition, we summarize the role of RNA modifications and nonsense-mediated mRNA decay (NMD) in Th17 cells. Ongoing research will help to identify practical applications for the regulation of mRNA stability and provide potential targets to prevent and treat Th17-related autoimmune diseases.

Increased peripheral helper T cells type 17 subset correlates with the severity of psoriasis vulgaris

Recently, a new subgroup of T cells, named peripheral helper T (Tph) cells, has been implicated in autoimmune pathogenesis. An imbalance of Tph cell subsets influences the severity of immune-related diseases. However, the characteristics and roles of Tph cell subsets in psoriasis remain unknown. Programmed cell death 1-positive, chemokine C-X-C receptor (CXCR) 5-negative Tph cells can be divided into 3 subgroups based on differential expression of chemokine CXCR3 and chemokine C-C receptor (CCR) 6. CXCR3⁺CCR6^- Tph cells are classified as Tph1, CXCR3^-CCR6^- Tph cells are classified as Tph2, and CXCR3^-CCR6⁺ Tph cells are classified as Tph17. In this study, conditions of circulating Tph cell subsets and CD4⁺CXCR5⁺ follicular helper T (Tfh) cells in 27 patients with psoriasis and 13 healthy individuals were detected by flow cytometry. The level of plasma chemokine C-X-C ligand (CXCL) 13 was measured by enzyme-linked immunosorbent assay. The correlations between the above indexes and disease severity were explored. In the peripheral blood of patients with psoriasis, Tph17 cells had an activated, proliferative phenotype; the quantity of the cells correlated with disease severity. Plasma CXCL13 levels were elevated in psoriasis and associated with disease severity and the frequency of Tph17 cells. CD4⁺CXCR5⁺ Tfh cells were increased in patients and positively correlated with disease severity, the frequency of Tph17 cells, and plasma CXCL13 levels. Our results suggest that Tph17 cells and the CXCL13/CXCR5 axis may be involved in the pathogenesis of psoriasis and represent new immunotherapeutic targets for treating psoriasis.

CXCL13 plasma levels function as a biomarker for disease activity in patients with chronic lymphocytic leukemia

The chemoattractant CXCL13 organizes the cellular architecture of B-cell follicles and germinal centers. During adaptive immune responses, CXCL13 plasma concentrations transiently increase and function as a biomarker for normal germinal center activity. Chronic lymphocytic leukemia (CLL) cells express high levels of CXCR5, the receptor for CXCL13, and proliferate in pseudofollicles within secondary lymphoid organs (SLO). Given the morphologic and functional similarities between normal and CLL B-cell expansion in SLO, we hypothesized that CXCL13 plasma concentrations would correlate with CLL disease activity and progression. We analyzed CXCL13 plasma concentrations in 400 CLL patients and correlated the findings with other prognostic markers, time to treatment (TTT), CCL3 and CCL4 plasma concentrations, and in vivo CLL cell proliferation. We found that CXCL13 plasma concentrations were higher in CLL patients with active and advanced stage disease, resulting in a significantly shorter TTT. Accordingly, high CXCL13 levels correlated with other markers of disease activity and CCL3 levels. Higher CLL cell birth rates in vivo also associated with higher CXCL13 plasma concentrations. Interestingly, elevated CXCL13 plasma levels normalized during ibrutinib therapy, and increased in ibrutinib resistance patients. Collectively, these studies emphasize the importance of CXCL13 in crosstalk between CLL cells and the SLO microenvironment.

Association Between Systemic Lupus Erythematosus and Myasthenia Gravis: Coincidence or Sequelae?

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease and myasthenia gravis (MG) is an organ-specific autoimmune disease, both may exhibit positive anti-nuclear antibodies and a female preponderance. They may have similar features and can coexist in a patient or precede one another.

This review article is based on electronic searches using PubMed as the primary database. Most of the articles used for this review were published in the last ten years with the exception of seven articles which were from 1995-2009. No guidelines have been followed. A total of 55 research articles were found related to the topic of this review article, and further scanning was done to eliminate some articles that did not meet the criteria.

The coexistence of autoimmune diseases has been reported in many cases. The prevalence of a second autoimmune disease is higher among patients with a primary diagnosis of autoimmune disease than the general population. The prevalence of SLE in MG patients or vice-versa is greater than the general population. The association has been hypothesized to many mechanisms: thymectomy resulting in loss of central tolerance and generation of autoantibodies, regulatory T cell dysfunction, the dysregulated function of Fas receptor (CD95), anti-malarial drugs directly affecting the neuromuscular junction, the role of chemokine CXCL13 and GM-CSF in the pathogenesis. The association is rare, and the presence of one should be closely followed for further progression into other diseases. More research work needs to be done for a clear conclusion.

Activated circulating T follicular helper cells and skewing of T follicular helper 2 cells are down-regulated by treatment including an inhaled corticosteroid in patients with allergic asthma

BACKGROUND

CXCR5⁺ T follicular helper (T_FH) cells primarily promote B cells to produce an antigen-specific antibody through germinal centers (GCs). T_FH cells exist in circulation, and circulating(c) T_FH2 cells, a subset of cT_FH cells, are able to help naïve B cells produce IgE in healthy individuals. Conversely, IL-10-producing regulatory B (Breg) cells inhibit an accelerated immune response.

METHODS

We investigated the roles of cT_FH cells and cBreg cells based on a T_H2 response in patients with atopic asthma (AA). Thirty-two patients with AA and 35 healthy volunteers (HV) were enrolled. We examined cT_FH cells including their subsets, their expression of ICOS and PD-1, and cBreg cells by flow cytometry and their associations with clinical biomarkers. Plasma levels of CXCL13, which is a counterpart of CXCR5, were also measured using ELISA.

RESULTS

In patients with AA, cT_FH2 cells were increased and cT_FH1 cells were decreased compared with those in HV. The expression levels of ICOS on cT_FH and their subset cells were elevated and Breg cells were greatly decreased. The plasma levels of CXCL13 in patients with AA were significantly elevated and correlated well with the cT_FH2/cBreg ratio. These cells were examined in 10 patients AA before and after inhaled corticosteroid (ICS) treatment. Interestingly, the percentages and numbers of T_FH2 and ICOS⁺ cT_FH cells declined after ICS treatment together with improvements in symptoms and clinical biomarkers.

CONCLUSIONS

The percentages and numbers of cT_FH2 and ICOS⁺ cT_FH cells might be useful as biomarkers of T_H2 typed airway inflammation in patients with AA.

Neopterin and CXCL-13 in Diagnosis and Follow-Up of Trypanosoma brucei gambiense Sleeping Sickness: Lessons from the Field in Angola

Human African Trypanosomiasis may become manageable in the next decade with fexinidazole. However, currently stage diagnosis remains difficult to implement in the field and requires a lumbar puncture. Our study of an Angolan cohort of T. b. gambiense-infected patients used other staging criteria than those recommended by the WHO. We compared WHO criteria (cell count and parasite identification in the CSF) with two biomarkers (neopterin and CXCL-13) which have proven potential to diagnose disease stage or relapse. Biological, clinical, and neurological data were analysed from a cohort of 83 patients. A neopterin concentration below 15.5 nmol/L in the CSF denoted patients with stage 1 disease, and a concentration above 60.31 nmol/L characterized patients with advanced stage 2 (trypanosomes in CSF and/or cytorachia higher than 20 cells) disease. CXCL-13 levels below 91.208 pg/mL denoted patients with stage 1 disease, and levels of CXCL-13 above 395.45 pg/mL denoted patients with advanced stage 2 disease. Values between these cut-offs may represent patients with intermediate stage disease. Our work supports the existence of an intermediate stage in HAT, and CXCL-13 and neopterin levels may help to characterize it.

Clinical Research on Prognostic Evaluation of Subjects With IPF by Peripheral Blood Biomarkers, Quantitative Imaging Characteristics and Pulmonary Function Parameters

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is an irreversible and progressive fatal interstitial lung disease with a poor prognosis. The aim of this study is to investigate the predictive value of combined blood biomarkers, pulmonary function and quantitative monitoring by computer-aided diagnosis (CAD) system in IPF patients.

METHODS

Pulmonary baseline function and pathological features of 126 patients with IPF were analyzed using spirometry and chest X-ray. Patients were divided into survival group and non-survival group after 5 years follow-up. The relationships the levels of peripheral blood biomarkers, quantitative imaging characteristics and pulmonary function were analyzed between the two groups.

RESULTS

The baseline level of serum Krebs von den Lungen-6 (KL-6) and C-X-C motif chemokine 13 (CXCL13) were moderately or highly correlated with annual changes in forced vital capacity (FVC), carbon monoxide diffusing capacity (DLCO), total lung capacity (TLC), total interstitial lung disease (ILD) lesions, and the volume changes of reticular. The baseline level of serum KL-6 was higher than the cut-off value of 800.0U/ml and baseline level of serum CXCL13 was higher than the cut-off value of 62.0pg/ml. IPF patients with baseline levels of serum KL-6 and CXCL13 lower than the cut-off value had longer median survival time.

CONCLUSIONS

Serum KL-6 and CXCL13 may be predictive biomarkers for the outcomes of patients with IPF patients and their baseline levels were related to the progression of pulmonary function and quantitative monitoring by CAD system.

Aberrant populations of circulating T follicular helper cells and regulatory B cells underlying idiopathic pulmonary fibrosis

Background

T follicular helper (Tfh) cells have been identified as a new category of helper T cells, which express CXCR5 on their surface and induce the production of antigen-specific antibodies. Many investigations have found morbid proliferation and/or activation of Tfh cells in systemic autoimmune and allergic diseases. It is also known that Tfh cells are regulated by regulatory B (Breg) cells in the deteriorating such diseases. Recently, CXCL13, a ligand of CXCR5, has been reported to increase in the peripheral blood and lungs of patients with idiopathic pulmonary fibrosis (IPF). This study aimed to investigate the involvement of Tfh cells and Breg cells in IPF.

Methods

Peripheral blood samples were obtained from 18 patients with IPF. We isolated heparinized peripheral blood mononuclear cells and investigated the proportions of Breg cells, Tfh cells, PD-1⁺ICOS⁺ Tfh cells (activated form of Tfh cells), and the Tfh-cell subsets by flow cytometry. These cell profiles were compared with those of 21 healthy controls. Furthermore, we investigated the correlations between profiles of lymphocytes and lung physiology.

Results

The median proportions of Tfh cells per total CD4⁺ T cells and of PD-1⁺ICOS⁺ proportion of Tfh cells per total Tfh cells was significantly more in the IPF patients (20.4 and 5.2%, respectively) compared with healthy controls (15.4 and 2.1%, respectively; p = 0.042 and p = 0.004, respectively). The proportion of Tfh2 cells per total Tfh cells was significantly higher and the proportion of Tfh17 was smaller in the IPF patients than healthy controls. The percentage of Breg cells to total B cells was significantly decreased in the IPF patients (median, 8.5%) compared with that in the controls (median, 19.7%; p < 0.001). The proportion of Breg cells was positively correlated with the annual relative change in diffusing capacity of the lungs for carbon monoxide in the IPF patients (r = 0.583, p = 0.018).

Conclusion

Proliferation and activation of Tfh cells and a decrease in Breg cells were observed in the peripheral blood of patients with IPF. The profile of the Tfh-cell subset also changed. Specific humoral immunity aberration would likely underlie complicated pathophysiology of IPF.

Heightened TLR7/9-Induced IL-10 and CXCL13 Production with Dysregulated NF-ҝB Activation in CD11chiCD11b+ Dendritic Cells in NZB/W F1 Mice

Systemic lupus erythematosus (SLE) is a chronic, multifactorial autoimmune disease that predominantly affects young females. Dysregulation of different immune cell populations leads to self-tolerance breakdown and subsequent multiple organ damage as the disease develops. Plasmacytoid dendritic cells (pDCs) are potent producers of type I interferon (IFN), while myeloid dendritic cells (mDCs) are more specialized in antigen presentations. We have previously reported that bone-marrow (BM)-derived pDCs from the murine lupus model New Zealand black/white F1 (BWF1) possess abnormalities. Therefore, this study continues to investigate what aberrant properties peripheral pDCs and mDCs possess in BWF1 and how they mediate SLE progression, by comparing their properties in pre-symptomatic and symptomatic mice. Results showed that CD11c^hiCD11b⁺ myeloid DCs expanded during the disease state with down-regulation of co-stimulatory molecules and major histocompatibility complex class II molecules (MHC II), but their capacity to stimulate T cells was not hampered. During the disease state, this subset of mDCs displayed heightened toll-like receptors 7 and 9 (TLR 7/9) responses with increased interleukin 10 (IL-10) and C-X-C motif chemokine ligand 13 (CXCL13) expressions. Moreover, the expressions of myeloid differentiation primary response 88 (Myd88) and nuclear factor kappa B subunit 1 (Nfkb1) were higher in CD11c^hiCD11b⁺ DCs at the disease stage, leading to higher nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 phosphorylation activity. In summary, we reported aberrant phenotypic properties with enhanced TLR7/9 responses of CD11c^hiCD11b⁺ DCs in SLE mediated by aberrant NF-κB signaling pathway. Our findings add additional and novel information to our current understanding of the role of DCs in lupus immunopathogenesis. Lastly, molecular candidates in the NF-κB pathway should be exploited for developing therapeutic targets for SLE.

Increased circulating CXCL13 levels in systemic lupus erythematosus and rheumatoid arthritis: a meta-analysis

OBJECTIVES

CXC ligand 13 (CXCL13) is known as B cell chemotactic factor (BLC), promoting the migration of B lymphocytes by communicating with its receptor CXCR5, which can be regarded as part of pathogenesis of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). This meta-analysis was to evaluate the circulating CXCL13 levels in SLE and RA.

METHODS

All articles were respectively gathered from PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) (by the end of 10 April 2019). According to random effects model, standardized mean difference (SMD) and 95% confidence interval (CI) of CXCL13 levels in SLE and RA were calculated by Stata 12.0 software.

RESULTS

Totally, 15 studies were selected (981 SLE patients and 380 healthy controls, 332 RA patients and 147 healthy controls). SLE and RA patients were significantly increased in circulating CXCL13 levels (SMD = 1.851, 95% CI 0.604-3.098; SMD = 1.801, 95% CI = 1.145-2.457). Subgroup analyses showed that SLE patients from the Chinese group and systemic lupus erythematosus disease activity index (SLEDAI) score ≥ 6 group had higher circulating CXCL13 levels (SMD = 2.182, 95% CI 0.135-4.229; SMD = 0.767, 95% CI 0.503-1.030). However, there were no significant changes in CXCL13 concentrations in SLE patients from the English and SLEDAI score < 6 group. Similarly, subgroup analyses presented that RA patients from different classifications showed higher circulating CXCL13 levels. There was no publication bias.

CONCLUSIONS

This meta-analysis demonstrated increased circulating CXCL13 concentrations in SLE and RA patients. Circulating CXCL13 levels may act as biomarkers and therapy targets in the diagnosis and treatment of SLE and RA.Key Point• First, CXC ligand 13 (CXCL13) is closely related to the pathogenesis of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), Second, this study may provide novel therapeutic targets for the treatment of SLE and RA patients. This meta-analysis provides a comprehensive analysis of circulating CXCL13 levels in patients with SLE and RA and also explores related influencing factors.

Increased Circulating CXCL10 in Non-Segmental Vitiligo Concomitant with Autoimmune Thyroid Disease and Alopecia Areata

Background

Vitiligo is a common acquired pigmentary disease caused by destruction of epidermal melanocytes in underlying autoimmune response. Few studies have been focused on the role of chemokines in non-segmental vitiligo (NSV) concomitant with autoimmune thyroid disease (AITD) and alopecia areata (AA).

Objective

The aim of this study was to determine the best serum biomarker for predictive role in the progression of vitiligo and to evaluate the influence of AA and/or AITD on vitiligo by using the biomarker.

Methods

This prospective cohort study recruited 45 NSV patients: 14 without either AITD or AA, 12 with AITD, 11 with AA, and 8 with both AITD and AA. Serum levels of CXCL1, CXCL8, CXCL9, CXCL10, CXCL12, CXCL13, and CXCL16 were analyzed by ELISA. CXCR3 mRNA expression was detected on PBMCs by RT-PCR. Improvement was evaluated using repigmentation scales.

Results

Serum CXCL10 levels, along with the expression of CXCR3 mRNA were higher in NSV patients with AITD or AA alone than in those without AITD or AA. Moreover, serum CXCL10 levels, along with the expression of CXCR3 mRNA were higher in NSV patients with both AITD and AA than in those with AITD or AA alone. Poorer repigmentation was observed in NSV patients with both AA and AITD than in those with AA or AITD alone.

Conclusion

CXCL10 could be a biomarker to predict the progression of NSV. Dermatologists should pay much attention to those NSV patients concomitant with AITD and/or AA, for comorbidity might lead to more active autoimmune reaction.

CXCL13 and Its Receptor CXCR5 in Cancer: Inflammation, Immune Response, and Beyond

It is well-established that the chemokine C-X-C motif ligand 13 (CXCL13) and its receptor, the G-protein coupled receptor (GPCR) CXCR5, play fundamental roles in inflammatory, infectious and immune responses. Originally identified as a B-cell chemoattractant, CXCL13 exerts important functions in lymphoid neogenesis, and has been widely implicated in the pathogenesis of a number of autoimmune diseases and inflammatory conditions, as well as in lymphoproliferative disorders. Current evidence also indicates that the CXCL13:CXCR5 axis orchestrates cell-cell interactions that regulate lymphocyte infiltration within the tumor microenvironment, thereby determining responsiveness to cytotoxic and immune-targeted therapies. In this review, we provide a comprehensive perspective of the involvement of CXCL13 and its receptor in cancer progression. Studies in recent years postulated novel roles for this chemokine in controlling the cancer cell phenotype, and suggest important functions in the growth and metastatic dissemination of solid tumors. Carcinogens have been found to induce CXCL13 production, and production of this chemokine within the tumor milieu has been shown to impact the proliferation, migration, and invasive properties of cancer cells. Thus, the complex networks of cellular interactions involving tumoral CXCL13 and CXCR5 integrate to promote cancer cell autonomous and non-autonomous responses, highlighting the relevance of autocrine and paracrine interactions in dictating the cancer phenotype. Dissecting the molecular and signaling events regulated by CXCL13 and how this chemokine dynamically controls the interaction between the cancer cell and the tumor microenvironment is key to identify novel effectors and therapeutic targets for cancer treatment.

Plasma IL-5 but Not CXCL13 Correlates With Neutralization Breadth in HIV-Infected Children

Children may be the optimal target for HIV vaccine development as they generate substantially more frequent and more potent broadly HIV neutralizing antibodies (bnAbs) than adults. Development of a biomarker that correlates with neutralization breadth in this group could function as a powerful tool to facilitate the development of an HIV vaccine. Previously, we observed that this preferential ability in HIV-infected children over adults to generate bnAbs is associated with an enrichment of circulating follicular helper T-cells (TFH) with an effector phenotype, and the presence of IL-21 secreting HIV-specific TFH within lymphoid tissue germinal centers (GC). In adults, bnAbs development has been linked with high plasma levels of CXCL13, a chemoattractant for CXCR5-expressing TFH cells to the lymph node GC. We sought to test this relationship in HIV-infected children, but found no association between neutralization breadth and plasma levels of CXCL13, or with the Th2 cytokines IL-4 and IL-13, or the TFH associated factor Activin A. However, we did find an unexpected association between plasma IL-5 levels and bnAb development in these children. Importantly, although CXCL13 correlated with total circulating TFH cells, it was not associated with effector TFH. Additionally, raised CXCL13 expression was associated with a lower CD4 percentage, higher viral load and a loss of immune function, implying it is associated with progressive disease rather than HIV-specific GC activity in these subjects. Taken together, our data suggests that IL-5 should be evaluated further as a candidate plasma biomarker for HIV neutralization breadth and for monitoring vaccine responses in the pediatric age group.

Epoxyeicosatrienoic Acid Analog EET-A Blunts Development of Lupus Nephritis in Mice

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disorder that causes life threatening renal disease and current therapies are limited with serious side-effects. CYP epoxygenase metabolites of arachidonic acid epoxyeicosatrienoic acids (EETs) demonstrate strong anti-inflammatory and kidney protective actions. We investigated the ability of an orally active EET analog, EET-A to prevent kidney injury in a mouse SLE model. Twenty-weeks old female NZBWF1 (SLE) and age-matched NZW/LacJ (Non SLE) were treated with vehicle or EET-A (10 mg/kg/d, p.o.) for 14 weeks and urine and kidney tissues were collected at the end of the protocol. SLE mice demonstrated marked renal chemotaxis with 30-60% higher renal mRNA expression of CXC chemokine receptors (CXCR) and CXC chemokines (CXCL) compared to Non SLE mice. In SLE mice, the elevated chemotaxis is associated with 5-15-fold increase in cytokine mRNA expression and elevated inflammatory cell infiltration in the kidney. SLE mice also had elevated BUN, serum creatinine, proteinuria, and renal fibrosis. Interestingly, EET-A treatment markedly diminished renal CXCR and CXCL renal mRNA expression in SLE mice. EET-A treatment also reduced renal TNF-α, IL-6, IL-1β, and IFN-γ mRNA expression by 70-80% in SLE mice. Along with reductions in renal chemokine and cytokine mRNA expression, EET-A reduced renal immune cell infiltration, BUN, serum creatinine, proteinuria and renal fibrosis in SLE mice. Overall, we demonstrate that an orally active EET analog, EET-A prevents renal injury in a mouse model of SLE by reducing inflammation.

Activated T-Follicular Helper 2 Cells Are Associated With Disease Activity in IgG4-Related Sclerosing Cholangitis and Pancreatitis

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) and autoimmune pancreatitis (AIP) are characterized by an abundance of circulating and tissue IgG4-positive plasma cells. T-follicular helper (Tfh) cells are necessary for B-cell differentiation into plasma cells. We aimed at elucidating the presence and phenotype of Tfh cells and their relationship with disease activity in IgG4-SC/AIP.

The correlational research among serum CXCL13 levels, circulating plasmablasts and memory B cells in patients with systemic lupus erythematosus: A STROBE-compliant article

We investigated whether serum CXC ligand 13 protein (CXCL13) levels correlate with the circulating plasmablasts and memory B-cells alteration in systemic lupus erythematosus (SLE) patients. The diagnostic use of CXCL13 concentrations in active lupus was also analyzed.A total of 36 SLE patients and 18 healthy controls were included. Serum CXCL13 levels were examined by enzyme-linked immunosorbent assay. The frequency and absolute count of circulating plasmablasts and memory B cells were analyzed by flow cytometry. Receiver operating characteristic curves (ROC curves) were generated to analyze the utility of serum CXCL13 level and plasmablasts frequency as tools for the recognition of active SLE.Elevation of serum CXCL13 levels, higher plasmablasts frequency, and reduction of memory B-cells count were observed in SLE patients, compared with healthy controls. Interestingly, correlational analyses showed not only significantly positive association between CXCL13 levels and SLE Disease Activity Index (SLEDAI) or plasmablasts frequency, but an inverse correlation between CXCL13 concentration and memory B-cell count. ROC curves showed that serum CXCL13 level and plasmablasts frequency were practical in identifying active disease from overall SLE patients, with considerable accuracy.Serum CXCL13 levels correlate with the alteration of plasmablasts and memory B cells in SLE. CXCL13 may be used as a practical tool in judgment of active SLE.

T Follicular Helper Cells As a New Target for Immunosuppressive Therapies

Over the past decade, antibody-mediated (humoral) rejection has been recognized as a common cause of graft dysfunction after organ transplantation and an important determinant for graft loss. In humoral alloimmunity, T follicular helper (Tfh) cells play a crucial role, because they help naïve B cells to differentiate into memory B cells and alloantibody-producing plasma cells within germinal centers. In this way, they contribute to the induction of donor-specific antibodies, which are responsible for the humoral immune response to the allograft. In this article, we provide an overview of the current knowledge on the effects of immunosuppressive therapies on Tfh cell development and function, and discuss possible new approaches to influence the activity of Tfh cells. In addition, we discuss the potential use of Tfh cells as a pharmacodynamic biomarker to improve alloimmune-risk stratification and tailoring of immunosuppression to individualize therapy after transplantation.

Advancing Point-of-Care (PoC) Testing Using Human Saliva as Liquid Biopsy

Salivary diagnostics is an emerging field for the encroachment of point of care technology (PoCT). The necessity of the development of point-of-care (PoC) technology, the potential of saliva, identification and validation of biomarkers through salivary diagnostic toolboxes, and a broad overview of emerging technologies is discussed in this review. Furthermore, novel advanced techniques incorporated in devices for the early detection and diagnosis of several oral and systemic diseases in a non-invasive, easily-monitored, less time consuming, and in a personalised way is explicated. The latest technology detection systems and clinical utilities of saliva as a liquid biopsy, electric field-induced release and measurement (EFIRM), biosensors, smartphone technology, microfluidics, paper-based technology, and how their futuristic perspectives can improve salivary diagnostics and reduce hospital stays by replacing it with chairside screening is also highlighted.

Re-Examining Neutrophil Participation in GN

Significant advances in understanding the pathogenesis of GN have occurred in recent decades. Among those advances is the finding that both innate and adaptive immune cells contribute to the development of GN. Neutrophils were recognized as key contributors in early animal models of GN, at a time when the prevailing view considered neutrophils to function as nonspecific effector cells that die quickly after performing antimicrobial functions. However, advances over the past two decades have shown that neutrophil functions are more complex and sophisticated. Specifically, research has revealed that neutrophil survival is regulated by the inflammatory milieu and that neutrophils demonstrate plasticity, mediate microbial killing through previously unrecognized mechanisms, demonstrate transcriptional activity leading to the release of cytokines and chemokines, interact with and regulate cells of the innate and adaptive immune systems, and contribute to the resolution of inflammation. Therefore, neutrophil participation in glomerular diseases deserves re-evaluation. In this review, we describe advances in understanding classic neutrophil functions, review the expanded roles of neutrophils in innate and adaptive immune responses, and summarize current knowledge of neutrophil contributions to GN.

Upregulation of (C-X-C motif) Ligand 13 (CXCL13) Attenuates Morphine Analgesia in Rats with Cancer-Induced Bone Pain

Background

The aim of this study was to investigate the role of chemokine (C-X-C motif) ligand 13 (CXCL13) in morphine tolerance in rats with cancer-induced bone pain (CIBP).

Material/Methods

We established a rat CIBP model and a rat CIBP-morphine tolerance (BM) model. BM rats were intrathecally administered rmCXCL13, neutralizing anti-CXCL13, and normal saline, while the control group rats underwent a sham operation and were injected with normal saline. The morphine analgesia was assessed by measuring mechanical withdrawal threshold (MWT) and mechanical withdrawal duration (MWD) at various time points. The co-expressions of CXCL13 and NeuN were measured by immunofluorescence double-staining. CXCL13 protein and mRNA expressions were detected by Western blot and quantitative real-time polymerase chain reaction (RT-qPCR), respectively.

Results

Compared to the sham-operation (S) group, the BM group showed obviously decreased MWT and increased MWD on Day 9 after CIBP, but obviously increased MWT and decreased MWD on Day 3 after morphine administration; subsequently, the MWT was decreased and MWD was increased (all P<0.05). In comparison with the S+saline group, increased MWT and decreased MWD were observed in BM rats on Day 3 after anti-CXCL13 administration, and obviously decreased MWT and increased MWD were found in BM rats on Day 3 after rmCXCL13 administration (all P<0.05).

Conclusions

Up-regulated CXCL13 has a negative role in morphine analgesia in relief of CIBP, which may provide a new target for the management of CIBP.

Phenotype and function of CXCR5+CD45RA-CD4+ T cells were altered in HBV-related hepatocellular carcinoma and elevated serum CXCL13 predicted better prognosis

The present study reveals an immunological characterization of circulating and tumor-infiltrating T follicular helper cells (Tfh), namely CXCR5⁺CD45RA⁻CD4⁺ T cells, and their related cytokines in hepatitis B virus-related hepatocellular carcinoma (HCC) patients. In HCC patients, circulating Tfh cells showed a CCR7⁺ and/or ICOS⁺ phenotype with increased Th2-like cells and decreased Th1-like and Th17-like subsets. Although the bulk frequency of circulating Tfh cells was not altered in HCC patients, the frequency of infiltrated CXCR5⁺CD45RA⁻CD4⁺ CD3⁺cells was higher in tumor than in para-tumor tissues, and Th1-like cells were the predominant phenotype. Circulating Tfh cells in HCC patients were defective in the production of IL-21 in vitro, which was in accordance with lower IL-21 levels in tumor tissues than in para-tumor tissues. Serum CXCL13 was increased in HCC patients and associated with recurrence-free survival after hepatectomy. This was confirmed in an additional HCC cohort of 111 patients with up to 5 years follow-up. Immunohistochemical staining indicated that the percentage of CXCR5⁺ or CXCL13⁺ cells was higher in poorly differentiated than in well-differentiated tumors. In conclusion, patients with HBV-related HCC showed altered phenotypes and impaired function of Tfh cells or subpopulations. CXCL13 could be a potential biomarker for predicting recurrence in HCC patients after hepatectomy.

Long non-coding RNA MEG3 inhibits microRNA-125a-5p expression and induces immune imbalance of Treg/Th17 in immune thrombocytopenic purpura

BACKGROUND

The imbalance of Treg/Th17 cells is an important pathogenic factor for immune thrombocytopenic purpura (ITP). We previously reported miR-125a-5p targeted CXCL13 and participated in the process of ITP. In the present study, the role of miR-125a-5p in regulating Treg/Th17 ratio and its potential molecular mechanism were investigated.

METHOD

A total of 30 adults with ITP and 30 healthy subjects were included. MEG3 expression in peripheral blood derived CD4+ T cells from ITP patients and healthy subjects were detected by real-time PCR. In vitro experiments, the effects of inhibiting or overexpressing MEG3 on the expression of miR-125a-5p, Foxp3 and ROTγt in CD4+ T cells were investigated.

RESULTS

MEG3 expression was increased in CD4+ T cells of patients with ITP. Dexamethasone decreased MEG3 expression level of CD4+ T cells in vitro. MEG3 directly interacted with miR-125a-5p and MEG3 overexpression inhibited miR-125a-5p expression in CD4+ T cells exposed to dexamethasone. MEG3 down-regulation or miR-125a-5p overexpression promoted Foxp3 expression and inhibited RORγt expression.

CONCLUSION

MEG3 interacted with miR-125a-5p and inhibited its expression, and MEG3/miR-125a-5p contributed to induce immune imbalance of Treg/Th17 in ITP.