ETV5 promotes lupus pathogenesis and follicular helper T cell differentiation by inducing osteopontin expression.

Follicular helper T (TFH) cells mediate germinal center reactions to generate high affinity antibodies against specific pathogens, and their excessive production is associated with the pathogenesis of systemic autoimmune diseases such as systemic lupus erythematosus (SLE). ETV5, a member of the ETS transcription factor family, promotes TFH cell differentiation in mice. In this study, we examined the role of ETV5 in the pathogenesis of lupus in mice and humans. T cell-specific deletion of Etv5 alleles ameliorated TFH cell differentiation and autoimmune phenotypes in lupus mouse models. Further, we identified SPP1 as an ETV5 target that promotes TFH cell differentiation in both mice and humans. Notably, extracellular osteopontin (OPN) encoded by SPP1 enhances TFH cell differentiation by activating the CD44-AKT signaling pathway. Furthermore, ETV5 and SPP1 levels were increased in CD4+ T cells from patients with SLE and were positively correlated with disease activity. Taken together, our findings demonstrate that ETV5 is a lupus-promoting transcription factor, and secreted OPN promotes TFH cell differentiation.

Liver X receptor controls follicular helper T cell differentiation via repression of TCF-1.

Liver X receptor (LXR) is a critical regulator of cholesterol homeostasis that inhibits T cell receptor (TCR)-induced proliferation by altering intracellular sterol metabolism. However, the mechanisms by which LXR regulates helper T cell subset differentiation remain unclear. Here, we demonstrate that LXR is a crucial negative regulator of follicular helper T (Tfh) cells in vivo. Both mixed bone marrow chimera and antigen-specific T cell adoptive cotransfer studies show a specific increase in Tfh cells among LXRß-deficient CD4+ T cell population in response to immunization and lymphocytic choriomeningitis mammarenavirus (LCMV) infection. Mechanistically, LXRß-deficient Tfh cells express augmented levels of T cell factor 1 (TCF-1) but comparable levels of Bcl6, CXCR5, and PD-1 in comparison with those of LXRß-sufficient Tfh cells. Loss of LXRß confers inactivation of GSK3ß induced by either AKT/Extracellular signal-regulated kinase (ERK) activation or Wnt/ß-catenin pathway, leading to elevated TCF-1 expression in CD4+ T cells. Conversely, ligation of LXR represses TCF-1 expression and Tfh cell differentiation in both murine and human CD4+ T cells. LXR agonist significantly diminishes Tfh cells and the levels of antigen-specific IgG upon immunization. These findings unveil a cell-intrinsic regulatory function of LXR in Tfh cell differentiation via the GSK3ß-TCF1 pathway, which may serve as a promising target for pharmacological intervention in Tfh-mediated diseases.

A single-centre retrospective study of factors affecting steroid-free remission of immunoglobulin G4-related disease conducted in South Korea: A notable outcome after complete resection.

OBJECTIVES: Few studies have examined factors affecting steroid-free remission (SFR) in patients with immunoglobulin G4-related disease (IgG4-RD). The aim of this study was to investigate clinical factors affecting SFR in IgG4-RD. METHODS: The medical records of 68 patients who met the 2020 revised comprehensive diagnostic criteria for IgG4-RD were reviewed retrospectively. SFR was defined as remission maintained for at least 6 months without corticosteroids. Cox regression analysis was performed to examine the associations between SFR and various clinical factors. The relapse rate after SFR was examined using the log-rank test. RESULTS: After a median follow-up of 36 months, 30.9% (21/68) of patients with IgG4-RD achieved SFR. Multivariate Cox regression analysis revealed that IgG4-RD diagnosed by complete resection rather than by common diagnostic procedures was the only factor positively associated with SFR (hazard ratio, 7.41; 95% confidence interval, 2.23-24.60; P = .001). Furthermore, relapse after attainment of SFR was significantly less common in the group that underwent complete resection than in the group that did not undergo complete resection (log-rank P = .006). CONCLUSIONS: Patients with IgG4-RD diagnosed by complete resection had a higher likelihood of achieving SFR and a lower rate of relapse after attaining SFR.

Predictors for future development of systemic lupus erythematosus in Korean Sjögren's syndrome patients.

OBJECTIVE: This study determined the impact of demographic factors, clinical manifestations, disease activity, and serological tests at baseline on future SLE development in Sjögren's syndrome (SS) patients. METHODS: This retrospective study assessed 1,082 SS patients without other autoimmune diseases at baseline who visited our hospital between January 2012 and March 2021. We analyzed demographic features, extra-glandular manifestations (EGMs), clinical indices, and laboratory values at baseline between the two groups divided per future SLE development (SS/SLE group vs SS group). The probability and predictors of SLE development in SS patients were estimated using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: The median follow-up duration was 1083.5 days. Forty-nine patients (4.5%) developed SLE that met the 2012 Systemic Lupus International Collaborating Clinics or 2019 EULAR/ACR classification criteria. The baseline EULAR SS disease activity index (ESSDAI) score was significantly higher in the SS/SLE group (p < .001). The SS/SLE group had more lymphadenopathy and renal involvement (p = .015 and p = .017, respectively). Shorter SS disease duration (<3 years) (hazard ratio [HR] = 2.12, p = .0328), high ESSDAI (HR = 8.24, p < .0001), leukopenia (HR = 4.17, p = .0005), thrombocytopenia (HR = 3.38, p = .0059), hypocomplementemia (HR = 29.06, p<.0001), and positive for anti-dsDNA (HR = 13.70, p < .0001), anti-ribonucleoprotein (RNP) (HR = 3.82, p = .0027), and anti-ribosomal P (HR = 6.70, p = .0002) at baseline were SLE development predictors in SS patients. CONCLUSION: Shorter disease duration and higher disease activity of SS at baseline may be risk factors for future SLE development. Serologic predictors of SLE development are hypocomplementemia, leukopenia, thrombocytopenia, and positivity for anti-dsDNA, anti-RNP, and anti-ribosomal P antibodies. If the above factors are observed, close monitoring will be necessary during the follow-up period, considering the possibility of future SLE development.

Kynurenine pathway can be a potential biomarker of fatigue in primary Sjögren's syndrome.

OBJECTIVES: Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease with low quality of life caused by various constitutional symptoms and glandular dysfunction. Although fatigue is one of the most frequent symptoms in pSS, its aetiology or biomarkers are poorly elucidated. We investigated potential relationship between severity of fatigue and the kynurenine pathway in pSS. METHODS: Clinical data and blood samples of 81 patients were obtained from a prospective cohort for pSS and compared with age- and sex-matched healthy controls (HC). Severity of fatigue was defined according to the fatigue domain scores in the ESSPRI. Potential biomarkers related to the kynurenine pathway were determined using ELISA. RESULTS: Of the total, 44 patients were defined as the "severe fatigue (ESSPRI fatigue ≥ 5)" group, whereas 37 as the "less fatigue (ESSPRI fatigue < 5)". Serum tryptophan levels in the severe fatigue group were significantly lower while those of kynurenine were higher. Serum interferon gamma, IDO1, and quinolinic acid levels were mostly higher in the less fatigue group. Kynurenine/tryptophan ratios were distinctly higher in the severe fatigue group than both HC and the less fatigue group (p < 0.001). This ratio showed a strong degree of positive correlation (r = 0.624, p < 0.001) with severity of fatigue in pSS while the other markers showed fair degrees of correlation. CONCLUSIONS: Serum markers related to the kynurenine pathway, especially the kynurenine/tryptophan ratio, may be associated with severity of fatigue in pSS. These results can provide guidance for further investigations on fatigue in pSS.

Mesenchymal Stem/Stromal Cell-Based Therapies in Systemic Rheumatic Disease: From Challenges to New Approaches for Overcoming Restrictions.

Systemic rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis, are chronic autoimmune diseases affecting multiple organs and tissues. Despite recent advances in treatment, patients still experience significant morbidity and disability. Mesenchymal stem/stromal cell (MSC)-based therapy is promising for treating systemic rheumatic diseases due to the regenerative and immunomodulatory properties of MSCs. However, several challenges need to be overcome to use MSCs in clinical practice effectively. These challenges include MSC sourcing, characterization, standardization, safety, and efficacy issues. In this review, we provide an overview of the current state of MSC-based therapies in systemic rheumatic diseases, highlighting the challenges and limitations associated with their use. We also discuss emerging strategies and novel approaches that can help overcome the limitations. Finally, we provide insights into the future directions of MSC-based therapies for systemic rheumatic diseases and their potential clinical applications.

Characterization and outcomes of 414 patients with primary SS who developed haematological malignancies.

OBJECTIVE: To characterize 414 patients with primary SS who developed haematological malignancies and to analyse how the main SS- and lymphoma-related features can modify the presentation patterns and outcomes. METHODS: By January 2021, the Big Data Sjögren Project Consortium database included 11 966 patients fulfilling the 2002/2016 classification criteria. Haematological malignancies diagnosed according to the World Health Organization (WHO) classification were retrospectively identified. RESULTS: There were 414 patients (355 women, mean age 57 years) with haematological malignancies (in 43, malignancy preceded at least one year the SS diagnosis). A total of 376 (91%) patients had mature B-cell malignancy, nearly half had extranodal marginal zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT lymphoma) (n = 197), followed by diffuse large B-cell lymphoma (DLBCL) (n = 67), nodal MZL lymphoma (n = 29), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (n = 19) and follicular lymphoma (FL) (n = 17). Rates of complete response, relapses and death were 80%, 34% and 13%, respectively, with a 5-year survival rate of 86.5% after a mean follow-up of 8 years. There were significant differences in age at diagnosis (younger in MALT, older in CLL/SLL), predominant clinical presentation (glandular enlargement in MALT lymphoma, peripheral lymphadenopathy in nodal MZL and FL, constitutional symptoms in DLBCL, incidental diagnosis in CLL/SLL), therapeutic response (higher in MALT lymphoma, lower in DLBCL) and survival (better in MALT, nodal MZL and FL, worse in DLBCL). CONCLUSION: In the largest reported study of haematological malignancies complicating primary SS, we confirm the overwhelming predominance of B-cell lymphomas, especially MALT, with the salivary glands being the primary site of involvement. This highly-specific histopathological scenario is linked with the overall good prognosis with a 5-year survival rate of nearly 90%.

Biologic retention rate and efficacy in patients with cluster-based phenotypes of ankylosing spondylitis: data from a Korean national biologics registry.

OBJECTIVES: Patients with ankylosing spondylitis (AS) have a heterogenic disease course and treatment response. Cluster-based phenotypes are useful for predicting AS disease course. Here, we compared drug retention and clinical efficacy of biologic disease-modifying anti-rheumatic drugs (bDMARDs) in AS patients with cluster A and cluster B phenotypes. METHODS: AS patients enrolled in the Korean College of Rheumatology BIOlogics registry were divided into cluster A (axial symptoms predominant) and cluster B (both axial and peripheral symptoms). Retention of bDMARDs was measured using Kaplan-Meier curve and Cox regression analyses. Clinical efficacy (BASDAI50, ASAS20, ASAS40, ASDAS inactive state, and clinically important improvement/major improvement of ASDAS) at 1-year follow-up was measured by logistic regression analysis. Also, propensity score (PS)-matched analyses were conducted. RESULTS: 1600 AS patients (1468 for cluster A, 132 for cluster B) were included. Kaplan-Meier curve analysis revealed that the drug retention rate was lower in cluster B patients (p=0.03). PS-matched analyses showed that the hazard ratio (HR) for drug discontinuation was signi cantly higher in cluster B patients (HR=1.568; 95% con dence interval =1.055-2.329). The odds ratio for BASDAI50 at 1-year was comparable between cluster A and cluster B patients in PS-matched and multivariate logistic regression analyses. A similar result was obtained in other clinical efficacy assessments. CONCLUSIONS: The drug retention rate was lower in cluster B patients than in cluster A patients; clinical efficacy was comparable between the two groups at 1-year follow-up. These results may help predict drug retention and clinical efficacy in AS patients.

Longitudinal analysis of symptom-based clustering in patients with primary Sjogren's syndrome: a prospective cohort study with a 5-year follow-up period.

BACKGROUND: Sjogren's syndrome (SS) is a heterogenous disease with various phenotypes. We aimed to provide a relevant subclassification based on symptom-based clustering for patients with primary (p) SS. METHODS: Data from patients in a prospective pSS cohort in Korea were analysed. Latent class analysis (LCA) was performed using patient reported outcomes, including pain, fatigue, dryness, and anxiety/depression. Clinical and laboratory differences between the classes were analysed. Latent transition analysis (LTA) was applied to the longitudinal data (annually for up to 5 years) to assess temporal stability of the classifications. RESULTS: LCA identified three classes among 341 patients with pSS (i.e., 'high symptom burden', 'dryness dominant', 'low symptom burden'). Each group had distinct laboratory and clinical phenotypes. LTA revealed that class membership remained stable over time. Baseline class predicted future salivary gland function and damage accrual represented by a Sjogren's syndrome disease damage index. CONCLUSION: Symptom-based clustering of heterogenous patients with primary Sjogren's syndrome provided a relevant classification supported by temporal stability over time and distinct phenotypes between the classes. This clustering strategy may provide more homogenous groups of pSS patients for novel treatment development and predict future phenotypic evolvement.

Niclosamide suppresses the expansion of follicular helper T cells and alleviates disease severity in two murine models of lupus via STAT3.

BACKGROUND: Autoantibody production against endogenous cellular components is pathogenic feature of systemic lupus erythematosus (SLE). Follicular helper T (TFH) cells aid in B cell differentiation into autoantibody-producing plasma cells (PCs). The IL-6 and IL-21 cytokine-mediated STAT3 signaling are crucial for the differentiation to TFH cells. Niclosamide is an anti-helminthic drug used to treat parasitic infections but also exhibits a therapeutic effect on autoimmune diseases due to its potential immune regulatory effects. In this study, we examined whether niclosamide treatment could relieve lupus-like autoimmunity by modulating the differentiation of TFH cells in two murine models of lupus. METHODS: 10-week-old MRL/lpr mice were orally administered with 100 mg/kg of niclosamide or with 0.5% methylcellulose (MC, vehicle) daily for 7 weeks. TLR7 agonist, resiquimod was topically applied to an ear of 8-week-old C57BL/6 mice 3 times a week for 5 weeks. And they were orally administered with 100 mg/kg of niclosamide or with 0.5% MC daily for 5 weeks. Every mouse was analyzed for lupus nephritis, proteinuria, autoantibodies, immune complex, immune cell subsets at the time of the euthanization. RESULTS: Niclosamide treatment greatly improved proteinuria, anti-dsDNA antibody levels, immunoglobulin subclass titers, histology of lupus nephritis, and C3 deposition in MRL/lpr and R848-induced mice. In addition, niclosamide inhibited the proportion of TFH cells and PCs in the spleens of these animals, and effectively suppressed differentiation of TFH-like cells and expression of associated genes in vitro. CONCLUSIONS: Niclosamide exerted therapeutic effects on murine lupus models by suppressing TFH cells and plasma cells through STAT3 inhibition.

Short-chain fatty acid butyrate induces IL-10-producing B cells by regulating circadian-clock-related genes to ameliorate Sjögren's syndrome.

OBJECTIVES: Sjögren's syndrome (SS) is an autoimmune disease caused by inflammation of the exocrine gland. The pathological hallmark of SS is the infiltration of lymphocytes into the salivary glands. Increased infiltration of T and B cells into salivary glands exacerbates symptoms of SS. Several recent studies have identified the role of gut microbiota in SS. Butyrate, one of the metabolites of the gut microbiota, regulates T cells; however, its effects on B cells and SS remain unknown. This study determined the therapeutic effect of butyrate on regulating B cells in SS. METHODS: Various concentrations of butyrate were intraperitoneally injected three times per week in NOD/ShiLtJ (NOD) mice, the prototype animal model for SS, and observed for more than 10 weeks. Whole salivary flow rate and the histopathology of salivary glands were investigated. Human submandibular gland (HSG) cells and B cells in mouse spleen were used to confirm the anti-inflammatory and immunomodulatory effects of butyrate. RESULTS: Butyrate increased salivary flow rate in NOD mice and reduced inflammation of salivary gland tissues. It also regulated cell death and the expression of circadian-clock-related genes in HSG cells. Butyrate induced B cell regulation by increasing IL-10-producing B (B10) cells and decreasing IL-17-producing B cells, through the circadian clock genes RAR-related orphan receptor alpha and nuclear receptor subfamily 1 group D member 1. CONCLUSION: The findings of this study imply that butyrate may ameliorate SS via reciprocal regulation of IL-10- and IL-17-producing B cells.

Renal function deterioration is an independent mortality determinant in Koreans diagnosed with lupus nephritis.

OBJECTIVE: To evaluate the predictors of mortality, mortality rate, and causes of death in patients with lupus nephritis (LN) depending on final renal function. METHODS: The cohort included 401 Korean patients diagnosed with LN between 1985 and 2019. We retrospectively analyzed the clinical and laboratory indices, treatment response, and the final renal function. The final renal function was defined by the last stable level of eGFR measured in an out-patient department more than 3 times before death occurred and was categorized into five groups depending on CKD stage. RESULTS: The median follow-up time after the diagnosis of LN was 131 months. No difference in baseline demographic characteristics and laboratory findings was found except for the proportion of Hb less than 10 mg/dl and baseline eGFR (p = 0.011 and 0.037). We found no significant differences in therapeutic parameters, but all the response parameters including treatment response at 6 months (p = 0.004) and 12 months (p = 0.004), time to remission (p < 0.001), final renal response (p < 0.001), and the final renal function (p < 0.001) differed significantly between the two groups. In multivariate Cox proportional hazards analysis, the final renal function was an independent risk factor predicting mortality. The main causes of death were infection and SLE flare. Contrary to existing knowledge, SLE flare also triggered mortality in a few patients with LN progressed to end-stage renal disease (ESRD). Only two cases of mortality occurred in the kidney transplantation (KT) group (n = 25) with a median follow-up period of 224 months. The overall mortality rates calculated using the Kaplan-Meier method were 6.8%, 10.3%, 19.7%, and 28.0% at 5, 10, 20, and 30 years, respectively. CONCLUSION: Renal function deterioration was an independent determinant of mortality in Korean patients with LN. SLE flare also caused mortality in patients with LN who required maintenance dialysis, suggesting the benefit of KT on lupus activity and survival.

Hypergammaglobulinaemia predicts glandular and extra-glandular damage in primary Sjögren's syndrome: results from the KISS cohort study.

OBJECTIVES: To investigate whether temporal changes in immunoglobulin (Ig) levels and persistent hypergammaglobulinaemia cause glandular and extra-glandular damage in patients with primary Sjögren's syndrome (pSS). METHODS: Cumulative demographics and clinical and serological data from pSS patients in the Korean Initiative pSS cohort were evaluated. Persistent hypergammaglobulinaemia was defined as mean IgG levels of ≥1600 mg/dL over 3 years. Salivary gland damage was assessed by measuring salivary flow impairment, and lacrimal gland damage was assessed by examining ocular structural abnormalities. Solid organ damage included neurological and pleuropulmonary damage, renal impairment and lymphoproliferative disease. Independent predictors of glandular and extra-glandular damage in the third year were identified by logistic regression. RESULTS: Of 256 patients with pSS (median age, 55 years; 98% female), 47% had hypergammaglobulinaemia at baseline. IgG levels fell during the first 2 years in patients with hypergammaglobulinaemia at baseline, but not in those with normal IgG levels. Changes in IgG levels were associated with hydroxychloroquine and glucocorticoids. In the third year of follow-up, salivary flow impairment and solid organ damage were present in 71% and 9% of patients, respectively. After adjusting for age and medication use, persistent hypergammaglobulinaemia was associated with salivary flow impairment and solid organ damage in the third year. Patients in whom IgG fell by more than 80 mg/dL from baseline over 2 years showed less solid organ damage. CONCLUSIONS: Persistent hypergammaglobulinaemia was associated with salivary gland and solid organ damage. Decreased IgG may attenuate progression to solid organ dysfunction.

Influence of the age at diagnosis in the disease expression of primary Sjögren syndrome. Analysis of 12,753 patients from the Sjögren Big Data Consortium.

OBJECTIVES: To analyse how the main components of the disease phenotype (sicca symptoms, diagnostic tests, immunological markers and systemic disease) can be driven by the age at diagnosis of primary Sjögren's syndrome (pSS). METHODS: By January 2021, the participant centres had included 12,753 patients from 25 countries that fulfilled the 2002/2016 classification criteria for pSS. The age at diagnosis was defined as the time when the attending physician confirmed fulfilment of the criteria. Patients were clustered according to age at diagnosis. 50 clusters with more than 100 observations (from 27 to 76 years) were used to study the influence of the age at diagnosis in the disease expression. RESULTS: There was a consistent increase in the frequency of oral dryness according to the age at diagnosis, with a frequency of <90% in patients diagnosed at the youngest ages and >95% in those diagnosed at the oldest ages. The smooth curves that best fitted a linear model were the frequency of dry mouth (adjusted R2 0.87) and the frequency of abnormal oral tests (adjusted R2 0.72). Therefore, for each 1-year increase in the age at diagnosis, the frequency of dry mouth increased by 0.13%, and the frequency of abnormal oral diagnostic tests by 0.11%. There was a consistent year-by-year decrease in the frequency of all autoantibodies and immunological markers except for cryoglobulins. According to the linear models, for each 1-year increase in the age at diagnosis, the frequency of a positive result decreased by 0.57% (for anti-Ro antibodies), 0.47% (for RF) and 0.42% (for anti-La antibodies). The ESSDAI domains which showed a more consistent decrease were glandular and lymph node involvement (for each 1-year increase in the age at diagnosis, the frequency of activity decreased by 0.18%), and constitutional, cutaneous, and haematological involvements (the frequency decreased by 0.09% for each 1-year increase). In contrast, other domains showed an ascending pattern, especially pulmonary involvement (for each 1-year increase in the age at diagnosis, the frequency of activity increased by 0.22%), and peripheral nerve involvement (the frequency increased by 0.09% for each 1-year increase). CONCLUSIONS: The influence of the age at diagnosis on the key phenotypic features of pSS is strong, and should be considered critical not only for designing a personalised diagnostic approach, but also to be carefully considered when analysing the results of diagnostic tests and immunological parameters, and when internal organ involvement is suspected at diagnosis.

Metformin Augments Anti-Inflammatory and Chondroprotective Properties of Mesenchymal Stem Cells in Experimental Osteoarthritis.

Mesenchymal stem cells (MSCs) can protect against cartilage breakdown in osteoarthritis (OA) via their immunomodulatory capacities. However, the optimization strategy for using MSCs remains challenging. This study's objective was to identify the in vivo effects of metformin-stimulated adipose tissue-derived human MSCs (Ad-hMSCs) in OA. An animal model of OA was established by intra-articular injection of monosodium iodoacetate into rats. OA rats were divided into a control group and two therapy groups (treated with Ad-hMSCs or metformin-stimulated Ad-hMSCs). Limb nociception was assessed by measuring the paw withdrawal latency and threshold. Our data show that metformin increased IL-10 and IDO expression in Ad-hMSCs and decreased high-mobility group box 1 protein, IL-1ß, and IL-6 expression. Metformin increased the migration capacity of Ad-hMSCs with upregulation of chemokine expression. In cocultures, metformin-stimulated Ad-hMSCs inhibited the mRNA expression of RUNX2, COL X, VEGF, MMP1, MMP3, and MMP13 in IL-1ß-stimulated OA chondrocytes and increased the expression of TIMP1 and TIMP3. The antinociceptive activity and chondroprotective effects were greater in OA rats treated with metformin-stimulated Ad-hMSCs than in those treated with unstimulated Ad-hMSCs. TGF-ß expression in subchondral bone of OA joints was attenuated more in OA rats treated with metformin-stimulated Ad-hMSCs. Our findings suggest that metformin offers a promising option for the clinical application of Ad-hMSCs as a cell therapy for OA.

Metabolic abnormalities exacerbate Sjögren's syndrome by and is associated with increased the population of interleukin-17-producing cells in NOD/ShiLtJ mice.

BACKGROUND: Sjögren's syndrome (SS) is an autoimmune disease mediated by lymphocytic infiltration into exocrine glands, resulting in progressive lacrimal and salivary destruction and dysfunctional glandular secretion. Metabolic syndrome influences the immune system. To investigate its relationship with metabolic abnormalities, we evaluated the pathogenesis of SS and the immune cell populations in non-obese diabetic NOD/ShiLtJ mice with type 1 diabetes (T1D). METHODS: To induce metabolic abnormalities, streptozotocin (STZ)-a glucosamine-nitrosourea compound that destroys pancreatic ß cells, resulting in T1D-was injected into NOD/ShiLtJ mice. The blood glucose level was measured to evaluate induction of T1D. The severity of SS was assessed by determining the body weight, salivary flow rate, and histologic parameters. The expression levels of proinflammatory factors in the salivary glands, lacrimal gland, and spleen were quantified by real-time PCR. The populations of various T- and B-cell subtypes in the peripheral blood, spleen, and salivary glands were assessed by flow cytometry. RESULTS: Induction of T1D in NOD/ShiLtJ mice increased both the severity of SS and the levels of proinflammatory cytokines in the salivary glands compared to the controls. Furthermore, the number of interleukin-17-producing immune cells in the peripheral blood, spleen, and salivary glands was increased in STZ- compared to vehicle-treated NOD/ShiLtJ mice. CONCLUSIONS: Metabolic abnormalities play an important role in the development of SS.

Myeloid-derived suppressor cells therapy enhance immunoregulatory properties in acute graft versus host disease with combination of regulatory T cells.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) play a critical role in modulating the immune response and promoting immune tolerance in models of autoimmunity and transplantation. Regulatory T cells (Tregs) exert therapeutic potential due to their immunomodulatory properties, which have been demonstrated both in vitro and in clinical trials. Cell-based therapy for acute graft-versus-host disease (aGVHD) may enable induction of donor-specific tolerance in the preclinical setting. METHODS: We investigated whether the immunoregulatory activity of the combination of MDSCs and Tregs on T cell and B cell subset and alloreactive T cell response. We evaluated the therapeutic effects of combined cell therapy for a murine aGVHD model following MHC-mismatched bone marrow transplantation. We compared histologic analysis from the target tissues of each groups were and immune cell population by flow cytometric analysis. RESULTS: We report a novel approach to inducing immune tolerance using a combination of donor-derived MDSCs and Tregs. The combined cell-therapy modulated in vitro the proliferation of alloreactive T cells and the Treg/Th17 balance in mice and human system. Systemic infusion of MDSCs and Tregs ameliorated serverity and inflammation of aGVHD mouse model by reducing the populations of proinflammatory Th1/Th17 cells and the expression of proinflammatory cytokines in target tissue. The combined therapy promoted the differentiation of allogeneic T cells toward Foxp3 + Tregs and IL-10-producing regulatory B cells. The combination treatment control also activated human T and B cell subset. CONCLUSIONS: Therefore, the combination of MDSCs and Tregs has immunomodulatory activity and induces immune tolerance to prevent of aGVHD severity. This could lead to the development of new clinical approaches to the prevent aGVHD.

The establishment of a rheumatoid arthritis primate model in Macaca fascicularis.

BACKGROUND: Rheumatoid arthritis (RA) is a long-term autoimmune disorder that mostly affects the joints and leads to the destruction of cartilage. An RA model in non-human primates is especially useful because of their close phylogenetic relationship to humans in terms of cross-reactivity to compounds developed using modern drug technologies. METHODS: We used a collagen-induced arthritis (CIA) model in Macaca fascicularis. CIA was induced by the immunization of chicken type II collagen. Swelling was measured as the longitudinal and transverse axes of 16 proximal interphalangeal joints. RESULTS: A new system for visual evaluation was created, with a perfect score of 16. Individual behavioral analysis was also conducted. Serum was collected once a week after the first immunization. Blood chemistry and inflammatory cytokine parameters were higher in the CIA group than in the wild type group. CONCLUSION: In conclusion, we established CIA in M. fascicularis, and the results can be used for drug evaluation models.

Metformin enhances the immunomodulatory potential of adipose-derived mesenchymal stem cells through STAT1 in an animal model of lupus.

OBJECTIVES: Mesenchymal stem cells (MSCs) are considered potential therapeutic agents for treating autoimmune disease because of their immunomodulatory capacities and anti-inflammatory effects. However, several studies have shown that there is no consistency in the effectiveness of the MSCs to treat autoimmune disease, including SLE. In this study, we investigated whether metformin could enhance the immunoregulatory function of MSCs, what mechanism is relevant, and whether metformin-treated MSCs could be effective in an animal lupus model. METHODS: Adipose-derived (Ad)-MSCs were cultured for 72 h in the presence of metformin. Immunoregulatory factors expression was analysed by real-time PCR and ELISA. MRL/lpr mice weekly injected intravenously with 1 × 106 Ad-MSCs or metformin-treated Ad-MSCs for 8 weeks. 16-week-old mice were sacrificed and proteinuria, anti-dsDNA IgG antibody, glomerulonephritis, immune complex, cellular subset were analysed in each group. RESULTS: Metformin enhanced the immunomodulatory functions of Ad-MSCs including IDO, IL-10 and TGF-ß. Metformin upregulated the expression of p-AMPK, p-STAT1 and inhibited the expression of p-STAT3, p-mTOR in Ad-MSCs. STAT1 inhibition by siRNA strongly diminished IDO, IL-10, TGF-ß in metformin-treated Ad-MSCs. As a result, metformin promoted the immunoregulatory effect of Ad-MSCs by enhancing STAT1 expression, which was dependent on the AMPK/mTOR pathway. Administration of metformin-treated Ad-MSCs resulted in significant disease activity improvement including inflammatory phenotype, glomerulonephritis, proteinuria and anti-dsDNA IgG antibody production in MRL/lpr mice. Moreover, metformin-treated Ad-MSCs inhibited CD4-CD8- T-cell expansion and Th17/Treg cell ratio. CONCLUSION: Metformin optimized the immunoregulatory properties of Ad-MSCs and may be a novel therapeutic agent for the treatment of lupus.

Epidemiological profile and north-south gradient driving baseline systemic involvement of primary Sjögren's syndrome.

OBJECTIVE: To characterize the systemic phenotype of primary Sjögren's syndrome at diagnosis by analysing the EULAR-SS disease activity index (ESSDAI) scores. METHODS: The Sjögren Big Data Consortium is an international, multicentre registry based on worldwide data-sharing cooperative merging of pre-existing databases from leading centres in clinical research in Sjögren's syndrome from the five continents. RESULTS: The cohort included 10 007 patients (9352 female, mean 53 years) with recorded ESSDAI scores available. At diagnosis, the mean total ESSDAI score was 6.1; 81.8% of patients had systemic activity (ESSDAI score ≥1). Males had a higher mean ESSDAI (8.1 vs 6.0, P < 0.001) compared with females, as did patients diagnosed at <35 years (6.7 vs 5.6 in patients diagnosed at >65 years, P < 0.001). The highest global ESSDAI score was reported in Black/African Americans, followed by White, Asian and Hispanic patients (6.7, 6.5, 5.4 and 4.8, respectively; P < 0.001). The frequency of involvement of each systemic organ also differed between ethnic groups, with Black/African American patients showing the highest frequencies in the lymphadenopathy, articular, peripheral nervous system, CNS and biological domains, White patients in the glandular, cutaneous and muscular domains, Asian patients in the pulmonary, renal and haematological domains and Hispanic patients in the constitutional domain. Systemic activity measured by the ESSDAI, clinical ESSDAI (clinESSDAI) and disease activity states was higher in patients from southern countries (P < 0.001). CONCLUSION: The systemic phenotype of primary Sjögren's syndrome is strongly influenced by personal determinants such as age, gender, ethnicity and place of residence, which are key geoepidemiological players in driving the expression of systemic disease at diagnosis.