Infiltration Of Salivary Glands Research Articles

Efficacy of BAFF inhibition and B-cell depletion in non-obese diabetic mice as a spontaneous model for Sjögren’s disease

IntroductionThe therapeutic interest of targeting B-cell activating factor (BAFF) in Sjögren’s disease (SjD) can be suspected from the results of two phase II clinical trials but has not been evaluated...

Age-associated B cell infiltration in salivary glands represents a hallmark of Sjögren's-like disease in aging mice.

Sjögren's disease (SjD), characterized by circulating autoantibodies and exocrine gland inflammation, is typically diagnosed in women over 50years of age. However, the contribution of age to SjD pathogenesis is unclear. C57BL/6 female mice at different ages were studied to investigate how aging influences the dynamics of salivary gland inflammation. Salivary glands were characterized for immune cell infiltration, inflammatory gene expression, and saliva production. At 8months, gene expression of several chemokines involved in immune cell trafficking was significantly elevated. At this age, age-associated B cells (ABCs), a unique subset of B cells expressing the myeloid markers CD11b and/or CD11c, were preferentially enriched in the salivary glands compared to other organs like the spleen or liver. The salivary gland ABCs increased with age and positively correlated with increased CD4 T follicular helper cells. By 14months, lymphocytic foci of well-organized T and B cells spontaneously developed in the salivary glands. In addition, the mice progressively developed high titers of serum autoantibodies. A subset of aged mice developed salivary gland dysfunction mimicking SjD patients. Our data demonstrates that aging is a significant confounding factor for SjD. Thus, aged female C57BL/6 mice are more appropriate and a valuable preclinical model for investigating SjD pathogenesis and novel therapeutic interventions.

Pulmonary Manifestations of Sjögren's Disease.

Sjögren's disease (SjD) is a chronic, progressive autoimmune condition of exocrine and extraglandular tissues. It can present with isolated disease characterized by lymphocytic infiltration of salivary or lacrimal glands, but in approximately one-third of the patients, lymphocytic infiltration extends beyond exocrine glands to involve extraglandular organs such as the lungs. Pulmonary complications have been reported to occur between 9 and 27% of patients with SjD across studies. Respiratory manifestations occur on a spectrum of severity and include airways disease, interstitial lung disease, cystic lung disease, and lymphoma. Lung involvement can greatly affect patients' quality of life, has a major impact on the overall prognosis, and frequently leads to alteration in the treatment plans, highlighting the importance of maintaining a high index of clinical suspicion and taking appropriate steps to facilitate early recognition and intervention.

Role of Matra Basti and Akshitarpan in the Management of Sjogren’s Syndrome W.S.R Vatadhikya Vatarakta: A Case Study

Sjögren’s syndrome, characterized by lymphocytic infiltration of salivary and lacrimal glands leading to glandular fibrosis and exocrine failure with Clinical manifestations of keratoconjunctivitis sicca, resulting from inadequate lubrication due to inflammatory infiltration of lacrimal glands, and xerostomia, manifesting as a dry mouth. In Ayurveda patient’s symptomatic representation can be correlated with vataadhkiya vatarakta. In the present case report, a 50-year-old female Lucy Chaudhary from Noida, Uttar Pradesh with complaints of dry eyes, dry mouth and pain in multiple joints with generalized weakness for the past three years. Previously she had taken allopathic treatment, but she did not have any relief. The patient was managed with Panchkarma procedures including Matra Basti and Akshi Tarpan for 16 days with an interval of 8 days. The therapy got its effective results in treating Sjögren's syndrome which depicts that Ayurveda therapeutic protocols can be successfully adopted in the case of Sjögren's syndrome.

High Prevalence of Vulvar and Hepatic Manifestations in a Series of 18 Histiocytosis with Brafdel Mutations

Introduction L-group histiocytosis (Erdheim-Chester disease (ECD) and Langerhans-cell histiocytosis (LCH)) are multi-system diseases characterized by histiocyte infiltration in several organs. These histiocytes frequently harbor activating somatic mutations of the MAP Kinase pathway. Many of these mutations are frequently associated with a specific phenotype: BRAF V600Emutated ECD patients have more frequently cardiac and vascular involvements, MAP2K1 mutated ECD patients may exhibit overt Rosai-Dorfman Disease (RDD) component, and ALK-mutated patients have a high prevalence of neurological involvement. Our objective was to describe characteristics of patients with histiocytosis and a particular BRAF-deletion mutation. Methods We performed a retrospective multi-center study. Patients were identified through the Histiocytosis national referral center pathology laboratory in Ambroise-Paré Hospital (Boulogne-Billancourt) in which all suspected diagnosis of histiocytosis samples are sent for proofreading and sequencing. Samples are sequenced with a specific panel next generation sequencing. We identified patients with BRAFdel mutations and contacted the centers for clinical, morphological, and biological datas. Results Twenty-four patients with a BRAFdel mutation were identified. Data were available for 18 of them. Most patients (n=17) had LCH (one with an ECD component) and one had an ECD. Median age at diagnosis was 50 years (IQR 35-78). The most frequent manifestations were hepatic (n=8, 44%) and vulvar (8/10 female gender patients, 80%). Other manifestations were cystic interstitial lung disease (n=6), lytic bone lesions (n=7), diabetes insipidus (n=6), panhypopituitarism (n=3), pachymeningitis (n=2), long bone osteosclerosis (n=1), perirenal infiltration (n=1), salivary gland infiltration (n=1) and digestive track infiltration (n=1). Hepatic manifestation was sclerosing cholangitis in all patients, and 5/6 patients had histiocytic infiltration in liver biopsy. All patients with sclerosing cholangitis had biological cholestasis, elevated aminotransferases, and hyperbilirubinemia. No patient had cirrhosis. Hepatic MRI, when performed, always showed cholangitis (5/5). PET-scan showed liver abnormalities in 4/6 patients (heterogenous liver uptake or uptake in biliary ducts). First line treatments included vinblastine (n=5), aracytine (n=1), methotrexate (n=1), cladribine (n=1) and cobimetinib (n=1). Nine patients did not receive any treatment. Two patients received cobimetinib, that resulted in partial remission and stable disease at 6 months. After a median follow-up of 43 (IQR 11-315 months), one patient had died from unknown cause. Conclusion BRAF-deletion mutations in histiocytoses are associated with a specific LCH pattern with high prevalence of hepatic and vulvar involvements. These manifestations should be carefully screened in these patients.

An immuno-lipidomic signature revealed by metabolomic and machine-learning approaches in labial salivary gland to diagnose primary Sjögren's syndrome.

Assessing labial salivary gland exocrinopathy is a cornerstone in primary Sjögren's syndrome. Currently this relies on the histopathologic diagnosis of focal lymphocytic sialadenitis and computing a focus score by counting lym=phocyte foci. However, those lesions represent advanced stages of primary Sjögren's syndrome, although earlier recognition of primary Sjögren's syndrome and its effective treatment could prevent irreversible damage to labial salivary gland. This study aimed at finding early biomarkers of primary Sjögren's syndrome in labial salivary gland combining metabolomics and machine-learning approaches. We used a standardized targeted metabolomic approach involving high performance liquid chromatography coupled with mass spectrometry among newly diagnosed primary Sjögren's syndrome (n=40) and non- primary Sjögren's syndrome sicca (n=40) participants in a prospective cohort. A metabolic signature predictive of primary Sjögren's syndrome status was explored using linear (logistic regression with elastic-net regularization) and non-linear (random forests) machine learning architectures, after splitting the data set into training, validation, and test sets. Among 126 metabolites accurately measured, we identified a discriminant signature composed of six metabolites with robust performances (ROC-AUC = 0.86) for predicting primary Sjögren's syndrome status. This signature included the well-known immune-metabolite kynurenine and five phospholipids (LysoPC C28:0; PCaa C26:0; PCaaC30:2; PCae C30:1, and PCaeC30:2). It was split into two main components: the first including the phospholipids was related to the intensity of lymphocytic infiltrates in salivary glands, while the second represented by kynurenine was independently associated with the presence of anti-SSA antibodies in participant serum. Our results reveal an immuno-lipidomic signature in labial salivary gland that accurately distinguishes early primary Sjögren's syndrome from other causes of sicca symptoms.

Targeting alarmin release reverses Sjogren's syndrome phenotype by revitalizing Ca2+ signalling.

Primary Sjogren's syndrome (pSS) is a systemic autoimmune disease that is embodied by the loss of salivary gland function and immune cell infiltration, but the mechanism(s) are still unknown. The aim of this study was to understand the mechanisms and identify key factors that leads to the development and progression of pSS. Immunohistochemistry staining, FACS analysis and cytokine levels were used to detect immune cells infiltration and activation in salivary glands. RNA sequencing was performed toidentify the molecular mechanisms involved in the development of pSS. The function assays include in vivo saliva collection along with calcium imaging and electrophysiology on isolated salivary gland cells in mice models of pSS. Western blotting, real-time PCR, alarmin release, and immunohistochemistry was performed to identify the channels involved in salivary function in pSS. We provide evidence that loss of Ca2+ signaling precedes a decrease in saliva secretion and/or immune cell infiltration in IL14α, a mouse model for pSS. We also showed that Ca2+ homeostasis was mediated by transient receptor potential canonical-1 (TRPC1) channels and inhibition of TRPC1, resulting in the loss of salivary acinar cells, which promoted alarmin release essential for immune cell infiltration/release of pro-inflammatory cytokines. In addition, both IL14α and samples from human pSS patients showed a decrease in TRPC1 expression and increased acinar cell death. Finally, paquinimod treatment in IL14α restored Ca2+ homeostasis that inhibited alarmin release thereby reverting the pSS phenotype. These results indicate that loss of Ca2+ signaling is one of the initial factors, which induces loss of salivary gland function along with immune infiltration that exaggerates pSS. Importantly, restoration of Ca2+ signaling upon paquinimod treatment reversed the pSS phenotype thereby inhibiting the progressive development of pSS.

PSMC6 induces immune cell infiltration and inflammatory response to aggravate primary Sjögren's syndrome.

Increasing evidence suggests that immune cell infiltration is involved in primary Sjögren's syndrome (pSS), while the underlying molecular mechanisms remain elusive. Herein, this study aims to explore the key molecular mechanism in immune cell infiltration in pSS based on Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were obtained, followed by weighted gene co-expression network analysis to acquire the pSS-related module genes. Moreover, pSS-related DEGs and module genes were intersected. Additionally, the correlation between key genes and immune cell infiltration was analyzed by CIBERSORT algorithm. Furthermore, pSS mouse models were established to explore the effects of PSMC6 on immune cell infiltration and inflammatory responses in pSS. A total of 51 DEGs and 334 key module genes were involved in the occurrence of pSS. The immune cell infiltration was correlated with pSS, and PSMC6, highly expressed in pSS samples, may be the key immune gene. In vivo animal experiments demonstrated that PSMC6 was upregulated in pSS, and PSMC6 knockdown could reduce lymphocytic infiltration in salivary glands and lacrimal glands and the levels of related inflammatory factors in the pSS and increase the proportion of Treg cells. Collectively, PSMC6 could induce immune cell infiltration and inflammatory responses to promote the occurrence of pSS, providing us with a potential therapeutic target for treating pSS.

Anticeramide Improves Sjögren’s Syndrome by Blocking BMP6-Induced Th1

T-cell dysfunction has been shown to play an important role in the pathogenesis of Sjögren’s syndrome (SS). In recent studies, the increased expression of BMP6 has been reported to be related to SS. However, the roles that BMP6 plays in immune homeostasis in the development of SS as well as the downstream signals activated by BMP6 remain unclear. In this study, we investigated the effects and molecular mechanisms of BMP6 on naive CD4+ T cells, showing that BMP6 could upregulate interferon (IFN)–γ secretion from CD4+ T cells through a ceramide/nuclear factor–κB pathway, with no effect on T-cell activation or proliferation. Moreover, an in vivo study showed that anticeramide treatment (myriocin) for an SS animal model (NOD/LtJ mice) could significantly decrease the IFN-γ expression and Th1 frequency in the salivary glands and suppress the inflammation infiltration in salivary glands and maintain the salivary flow rates, both of which reflect SS-like symptoms. This study identifies a promising target that could effectively attenuate the abnormal state of CD4+ T cells and reverse the progression of SS.

Low-dose interleukin-2 can improve salivary secretion but not lymphocyte infiltration of salivary glands in a murine model of Sjögren’s syndrome

Introduction/aimEffects of low-dose interleukin-2 (IL-2) on the exocrine glandular glands of Sjögren’s syndrome are unknown. The aim of this study was to investigate the effects of low-dose IL-2 on salivary gland structure and function in a murine model of Sjögren’s syndrome.Materials and methodsNon-obese diabetic/Ltj (NOD) mice were used as the animal model of Sjögren’s syndrome, and low-dose IL-2 or phosphate buffered saline was administered subcutaneously from 5 weeks of age, while ICR mice were used as controls. Some mice were sacrificed at 9 weeks of age, while the other mice that continued to receive treatment were sacrificed at 23 weeks. We determined the salivary flow rate of mice every 3 weeks during the intervention. After the mice were sacrificed, one submandibular gland was removed for pathological evaluation, while the other submandibular gland was used to measure the levels of 25 cytokines by Luminex technology. Cervical lymph nodes and spleens were examined by flow cytometry for the proportions of CD8+ T cells and Treg cells.ResultsThe results showed that the salivary flow rate of NOD mice was slower than that of control-group mice, and there were more pathological changes in the submandibular gland. The levels of many cytokines in the submandibular gland were elevated. The proportion of CD8+ T cells in the cervical lymph nodes and spleens was increased; however, the proportion of Treg cells was decreased. After treatment with IL-2, the exocrine function of the salivary glands of mice was improved. IL-2 also promoted the proliferation of Treg cells in the cervical lymph nodes and spleens, but it did not alter the extent of lymphocyte infiltration in the submandibular gland. The levels of cytokines in the submandibular glands, as well as the proportion of CD8+ T cells in the cervical lymph nodes and spleens, were unchanged significantly after IL-2 treatment.ConclusionOur results demonstrate that treatment with low-dose IL-2 improves the secretory function of the exocrine glands of mice with Sjögren’s syndrome, but it does not reverse the structural damage of the exocrine glands.

In Vivo Generation of SSA/Ro Antigen-Specific Regulatory T Cells Improves Experimental Sjögren's Syndrome in Mice.

Sjögren's syndrome (SS) is a systemic autoimmune disease, and T cells play an important role in the initiation and perpetuation of the disease. In this study, we developed an immunotherapy for NOD/LtJ mice with SS-like symptoms by combining a transient depletion of CD4+ T cells with the administration of autoantigen-specific peptide Ro480. NOD/LtJ mice were treated with single anti-CD4 monoclonal antibody (mAb) followed 2 days later by a series of 6 intraperitoneal injections of Ro480-494 every other day. Salivary flow rates were determined pre- and posttreatment once a week. Mice were euthanized 6 weeks after the initial anti-CD4 mAb treatment, salivary glands (SGs) were collected for analyses of histologic disease scores and inflammatory cell infiltration, polymerase chain reaction determination of genes was conducted, and flow cytometry analysis including major histocompatibility complex class II tetramer staining of immune cells was performed. In addition, adoptive transfer of Treg cells was administrated to investigate the function of the newly generating Treg cells in vivo. The combination of anti-CD4 mAb with autoantigen-specific peptide Ro480 generated SSA/Ro antigen-specific Treg cells in vivo, which can suppress interferon-γ production of CD4+ T cells and inflammation infiltration in SGs and maintain the function of SGs. Our findings provide a new approach to generating antigen-specific Treg cells in vivo for SS treatment, which may have implications for potential therapy for patients with SS.

Diagnostic Performances of Ultrasound Evaluation of Major Salivary Glands According to the 2019 Outcome Measures in Rheumatology Ultrasound Scoring System.

To evaluate the diagnostic performance of ultrasound examination of the salivary glands (US-SG) according to the 2019 Outcome Measures in Rheumatology (OMERACT) US scoring system for Sjögren's syndrome (SS). The present work was a retrospective study based on a multicentric cohort with SS/sicca syndrome. The American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) 2016 classification criteria for SS (a score of ≥4 without ocular staining score), the American-European Consensus Group (AECG) 2002 classification criteria, and clinician experts were considered as reference standards for diagnosis of SS. An OMERACT score of ≥2 according to 2 independent readers defined the diagnosis of SS based on US-SG assessment. Diagnostic performances and interobserver reproducibility of US-SG were assessed. Forty-two patients fulfilling the ACR/EULAR 2016 criteria for SS were compared to 30 control subjects with sicca syndrome. Twenty-five patients were diagnosed as having SS according to US-SG evaluation, and they were more frequently observed in the SS group (52.5%) than in the control group (10.0%) (P < 0.001). US-SG showed an area under the curve (AUC) of 0.751 (95% confidence interval [95% CI] 0.621, 0.882) for the diagnosis of SS (ACR/EULAR 2016 classification). The inclusion of US-SG in the ACR/EULAR 2016 classification improved sensitivity (91.5% versus 89.4%) with limited decrease of specificity (96.0% versus 100%) and with an AUC of 0.975 (95% CI 0.945, 1.00). Similar results were observed when US-SG was included in the AECG 2002 classification criteria. Interobserver reproducibility of a score of ≥2 according to the 2019 OMERACT US scoring system for SS diagnosis was good (κ=0.73 [95% CI 0.64, 0.81]). Histologic lymphocyte infiltration of the minor salivary glands was associated with the OMERACT grading of US-SG. The present study confirms the good specificity of the 2019 OMERACT US classification measures of US-SG for the diagnosis of SS and its feasibility in daily practice.

Imaging Activated-T-Lymphocytes in the Salivary Glands of Patients with Sjögren's Syndrome by 99mTc-Interleukin-2: Diagnostic and Therapeutic Implications.

Background: Sjögren’s syndrome (SS) is a progressive autoimmune disease characterized by local mononuclear cell infiltration of the salivary and lachrymal glands. Labial biopsy demonstrates local infiltration by Th1 cells that produce pro-inflammatory cytokines, such as interleukin-2 (IL2). The aim of this study was to assess the utility of 99mTc-labelled-IL2 (99mTc-IL2) in evaluating in vivo the extent and severity of lympho-mononuclear cell infiltration in the salivary glands of patients with SS. Methods: We investigated 48 patients with primary SS and 27 control subjects using 99mTc-IL2 scintigraphy. Furthermore, in a subgroup of 30 patients, we also performed 99mTc-pertechnetate scintigraphy (99mTcO4−) for evaluation of the salivary gland function. Results: 99mTc-IL2 uptake in the salivary glands of SS patients was higher than in the control subjects (1.30 ± 0.16 vs. 0.83 ± 0.08 for parotids and 1.36 ± 0.15 vs. 1.16 ± 0.07 for submandibular glands; p < 0.0001). The salivary gland uptake of 99mTc-IL2 in patients with a longer history of disease was lower compared with the recently diagnosed patients. A significant direct correlation was found between the uptake of 99mTc-IL2 and histology. Conclusions: 99mTc-IL2 scintigraphy showed that the degree of lymphocytic infiltration of major salivary glands is variable in patients with different disease durations. Patients with a high 99mTc-IL2 uptake could be efficiently treated with immuno-modulatory drugs and the efficacy of treatment could be followed-up by 99mTc-IL2 scintigraphy.

Sjögren's Syndrome-Related Organs Fibrosis: Hypotheses and Realities.

Sjögren’s syndrome (SS) is a systemic chronic autoimmune disorder characterized by lymphoplasmacytic infiltration of salivary glands (SGs) and lacrimal glands, causing glandular damage. The disease shows a combination of dryness symptoms found in the oral cavity, pharynx, larynx, and vagina, representing a systemic disease. Recent advances link chronic inflammation with SG fibrosis, based on a molecular mechanism pointing to the epithelial to mesenchymal transition (EMT). The continued activation of inflammatory-dependent fibrosis is highly detrimental and a common final pathway of numerous disease states. The important question of whether and how fibrosis contributes to SS pathogenesis is currently intensely debated. Here, we collect the recent findings on EMT-dependent fibrosis in SS SGs and explore clinical evidence of multi-organ fibrosis in SS to highlight potential avenues for therapeutic investigation.

Sirolimus therapy restores the PD-1+ICOS+Tfh:CD45RA-Foxp3high activated Tfr cell balance in primary Sjögren’s syndrome

BackgroundPrimary Sjögren’s syndrome (pSS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands. The current study was performed to investigate the roles of follicular helper T (Tfh) and follicular regulatory T (Tfr) subsets in patients with pSS, and to evaluate the effects of sirolimus on these cells. MethodsLevels of circulating Tfh and Tfr subsets in 58 pSS patients and 26 healthy controls (HC) were determined by flow cytometry. These T cell subsets were also analyzed in 12 patients before and after treatment with sirolimus. Clinical features and correlations with follicular T cells were analyzed systematically. The discriminative ability of the cells and ratios was evaluated based on the area under the receiver operating characteristic curves. ResultsPatients with pSS had higher percentage and absolute number of PD-1+ICOS+Tfh cells, while lower percentage and absolute number of Tfr, activated regulatory T (aTreg) cells, and CD45RA-Foxp3high activated Tfr cells. Furthermore, increased number of PD-1+ICOS+Tfh cells was associated with B cells, while decreased numbers of Tfr and their subsets was strongly associated with aTreg cells in pSS patients. Also, the higher proportion of PD-1+ICOS+Tfh cells was positively correlated with higher level of autoantibodies, ESR, IgG, cytokines (IL-2, IL-4, IL-10, IL-17, IFN-γ, TNF-α, IL-21 and sIL-2αR), and disease activity. Unexpectedly, the elevated PD-1+ICOS+Tfh:CD45RA-Foxp3high activated Tfr ratio had the greatest ability to discriminate between pSS and HC, and sirolimus therapy restored the PD-1+ICOS+Tfh cells:CD45RA-Foxp3high activated Tfr ratio, and controlled disease activity. ConclusionThe novel ratio of PD-1+ICOS+Tfh to CD45RA-Foxp3high activated Tfr cells can effectively discriminate the pSS patients from controls, and Tfr cell subsets may resemble Treg cell lineages. Furthermore, the PD-1+ICOS+Tfh cells can be used as a biomarker of disease activity and to verify the therapeutic effects of sirolimus in pSS.

Umbilical cord mesenchymal stem cells alleviate Sjögren's syndrome and related pulmonary inflammation through regulating Vγ4+ IL-17+ T cells.

BackgroundSince gamma delta (γδ) T cells are involved in various autoimmune diseases, we aimed to verify whether γδ T cells participate in the pathogenesis of Sjögren’s syndrome (SS) and related pulmonary inflammation, and also aimed to evaluate the effects of umbilical cord mesenchymal stem cells (MSCs) on SS-related pulmonary inflammation and the γδ T cells.MethodsThe saliva flow rates of female non-obese diabetic (NOD/Ltj) mice were measured. Histopathologic analysis was performed in salivary glands (SG) and lung tissues. The levels of γδ T cells and their subsets in the peripheral blood, spleen, and lung were examined by flow cytometry. The purified γδ T cells were adoptively transferred into NOD/Ltj mice. MSC transplantation was performed in 8-week-old NOD/Ltj mice.ResultsThe results showed lymphocytic infiltration in SG and lacrimal glands (LG), and reduction of saliva flow rates in 8-week NOD/Ltj mice. The levels of γδ T cells decreased in peripheral blood, but increased in the lung of 8- and 12-week-old NOD/Ltj mice. The proportions and numbers of Vγ4+ T cells and Vγ4+ IL-17A+ T cells increased in the lung, but decreased in peripheral blood of 8-week-old NOD/Ltj mice. Notably, transfer of γδ T cells decreased the rate of saliva flow, as well as aggravated the pathological changes in the lung. The transplantation of MSCs increased saliva flow rate and alleviated pathological injury in the SG and lung. The frequencies of Vγ4+ T cells and Vγ4+ IL-17A+ T cells in the lung and spleen significantly decreased after MSC treatment. Our results demonstrated that γδ T cells and Vγ4+ T cells contribute to the pathogenesis of SS and SS-related pulmonary inflammation. In addition, MSCs relieved SS and SS-related pulmonary inflammation through suppressing Vγ4+ IL-17A+ T cells.ConclusionsPeripheral Vγ4+ T cells infiltrate into the lung in SS mice, and aggravate the symptoms of SS and SS-related pulmonary inflammation by secreting IL-17A. Meanwhile, lymphocyte infiltration could be reversed by MSC transplantation, which indicates the potential of MSCs in the treatment of SS and SS-related pulmonary inflammation patients.

CD163+ M2 Macrophages Promote Fibrosis in IgG4-Related Disease Via Toll-like Receptor 7/Interleukin-1 Receptor-Associated Kinase 4/NF-κB Signaling.

ObjectiveIgG4‐related disease (IgG4‐RD) is a fibro‐inflammatory condition that can affect multiple organs. We previously demonstrated that TLR7‐transgenic C57BL/6 mice showed elevated serum IgG1 levels and inflammation with fibrosis in the salivary glands (SGs), lungs, and pancreas. Moreover, we observed extensive Toll‐like receptor 7 (TLR‐7)–positive CD163+ M2 macrophage infiltration in SGs from IgG4‐RD patients. We undertook this study to examine the fibrotic mechanism via the TLR‐7 pathway.MethodsGene expression in SGs from human TLR7‐transgenic mice and IgG4‐RD patients was analyzed using DNA microarrays. We extracted the common up‐regulated TLR‐7–related genes in SGs from TLR7‐transgenic mice and IgG4‐RD patients. Finally, we investigated the interaction between CD163+ M2 macrophages and fibroblasts before and after stimulation with the TLR‐7 agonist loxoribine.ResultsIn TLR7‐transgenic mice and IgG4‐RD patients, IRAK3 and IRAK4 were significantly overexpressed. Real‐time polymerase chain reaction validated the up‐regulation of only IRAK4 in IgG4‐RD patients compared with the other groups (P < 0.05). Interleukin‐1 receptor–associated kinase 4 (IRAK4) was strongly detected in and around germinal centers in SGs from patients with IgG4‐related dacryoadenitis and sialadenitis alone. Double immunofluorescence staining showed that IRAK4‐positive cells were mainly colocalized with CD163+ M2 macrophages in SGs (P < 0.05). After stimulation with loxoribine, CD163+ M2 macrophages exhibited significantly enhanced expression of IRAK4 and NF‐κB and increased supernatant concentrations of fibrotic cytokines. Finally, we confirmed that the number of fibroblasts was increased by culture with the supernatant of CD163+ M2 macrophages following stimulation with loxoribine (P < 0.05).ConclusionCD163+ M2 macrophages promote fibrosis in IgG4‐RD by increasing the production of fibrotic cytokines via TLR‐7/IRAK4/NF‐κB signaling.

A Link Between Mitochondrial Dysfunction and the Immune Microenvironment of Salivary Glands in Primary Sjogren's Syndrome.

BackgroundPrimary Sjogren’s syndrome (pSS) is a slowly progressive, inflammatory autoimmune disease characterized by lymphocytic infiltration into salivary and lacrimal glands. It becomes more recognized that morphology alterations of epithelial mitochondria are involved in altered cellular bioenergetics in pSS patients. The integrated analysis of the mitochondrial role in the pathogenesis and aberrant immune microenvironment in pSS remains unknown.MethodsThe mitochondria-related genes and gene expression data were downloaded from the MitoMiner, MitoCarta, and NCBI GEO databases. We performed novel transcriptomic analysis and constructed a network between the mitochondrial function and immune microenvironment in pSS-salivary glands by computer-aided algorithms. Subsequently, real-time PCR was performed in clinical samples in order to validate the bioinformatics results. Histological staining and transmission electron microscopy (TEM) were further studied on labial salivary gland samples of non-pSS and pSS patients characterized for mitochondria-related phenotypic observation in the different stages of the disease.ResultsThe bioinformatic analysis revealed that the expression of several mitochondria-related genes was altered in pSS. Quantitative real-time PCR showed that four hub genes, CD38, CMPK2, TBC1D9, and PYCR1, were differentially expressed in the pSS clinical samples. These hub genes were associated with the degree of immune cell infiltration in salivary glands, the mitochondrial respiratory chain complexes, mitochondrial metabolic pathway in gluconeogenesis, TCA cycle, and pyruvate/ketone/lipid/amino acid metabolism in pSS. Clinical data revealed that the gene expression of fission (Fis1, DRP1, and MFF) and fusion (MFN1, MFN2, and OPA1) was downregulated in pSS samples, consistent with the results from the public validation database. As the disease progressed, cytochrome c and Bcl-2 proteins were regionally distributed in salivary glands from pSS patients. TEM revealed cytoplasmic lipid droplets and progressively swollen mitochondria in salivary epithelial cells.ConclusionOur study revealed cross talk between mitochondrial dysfunction and the immune microenvironment in salivary glands of pSS patients, which may provide important insights into SS clinical management based on modulation of mitochondrial function.

Ruxolitinib inhibits IFNγ-stimulated Sjögren's salivary gland MSC HLA-DR expression and chemokine-dependent T cell migration.

Sjögren's disease (SjD) is a systemic autoimmune disease characterized by focal lymphocytic infiltrate of salivary glands (SGs) and high SG IFNγ, both of which are associated with elevated lymphoma risk. IFNγ is also biologically relevant to mesenchymal stromal cells (MSCs), a SG resident cell with unique niche regenerative and immunoregulatory capacities. In contrast to the role of IFNγ in SjD, IFNγ promotes an anti-inflammatory MSC phenotype in other diseases. The objective of this study was to define the immunobiology of IFNγ-exposed SG-MSCs with and without the JAK1 & 2 inhibitor, ruxolitinib. SG-MSCs were isolated from SjD and controls human subjects. SG-MSCs were treated with 10 ng/ml IFNγ +/- 1000 nM ruxolitinib. Experimental methods included flow cytometry, RNA-sequencing, chemokine array, ELISA and transwell chemotaxis experiments. We found that IFNγ promoted expression of SG-MSC immunomodulatory markers, including HLA-DR, and this expression was inhibited by ruxolitinib. We confirmed the differential expression of CXCL9, CXCL10, CXCL11, CCL2 and CCL7, initially identified with RNA sequencing. SG-MSCs promoted CD4+ T cell chemotaxis when pre-stimulated with IFNγ. Ruxolitinib blocks chemotaxis through inhibition of SG-MSC production of CXCL9, CXCL10 and CXCL11. These findings establish that ruxolitinib inhibits IFNγ-induced expression of SG-MSC immunomodulatory markers and chemokines. Ruxolitinib also reverses IFNγ-induced CD4+ T cell chemotaxis, through inhibition of CXCL9, -10 and -11. Because IFNγ is higher in SjD than control SGs, we have identified SG-MSCs as a plausible pathogenic cell type in SjD. We provide proof of concept supporting further study of ruxolitinib to treat SjD.

Clinical and laboratory characteristics of lymphoproliferative diseases in primary Sjogren's syndrome associated with anticentromere antibodies

Purpose of the study. To study the characteristics and frequency of lymphomas in patients with Sjogren's disease (SD) and anticentromere antibodies (ACA); to evaluate the predictors of the development of lymphoproliferative diseases (LPD) in this group of patients. Material and methods. Over the period from 1998 till 2019, 131 ACA-positive patients were under medical supervision at the Research Institute of Rheumatology named after Nasonova V.A. Isolated SD was diagnosed in 82 patients (62.6%), isolated limited form of SSc — in 12 patients (9.2%), combination of SD and limited form of SSc — in 37 patients (28.2%). Lymphoproliferative diseases (LPD) were diagnosed in 20 ACA-positive patients: in 15 — with SD, in 5 — with SD and SSc; no lymphomas were found in the group of patients with isolated SSc. All lymphomas were diagnosed on the basis of histological, immunohistochemical and PCR examination with of B-cell clonality determination in the tissue, and were classified on the base of haematopoietic and lymphoid tissue tumors classification by the World Health Organization. Further analysis included 15 ACA-positive patients with isolated SD and lymphomas. Results. In our study, 18.3% of patients with isolated ACA-positive SD were diagnosed with LPD, represented by MALT lymphomas of the salivary glands (subsequent transformation into aggressive diffuse large B-cell lymphoma (DLBCL) was noted in one patient) in most cases. The course of SD before the diagnosis of LPD was characterized by a gradual progression of dental manifestations of SD with the development of late stages of parenchymal parotitis, severe xerostomia, and significant enlargement of the salivary glands with a minimum number of systemic manifestations of the disease. Significant enlargement of salivary glands, severe infiltration of minor salivary glands, severe xerostomia, decreased level of C4-complement component, monoclonal secretion, low content of CD19+B-cells in peripheral blood, positive B-cell clonality in biopsy material were the main signs of LPD in this study. When diagnosing MALT lymphomas, a focal damage of the salivary glands with no signs of dissemination, no symptoms of B-cell intoxication, and minimal changes in laboratory assessment were found in patients with ACA-positive SD. Conclusion. The natural course of ACA-positive SD and the absence of pathogenetic therapy at an early stage contribute to the development of salivary gland lymphomas in the first 10 years of the disease. Persistent enlargement of the salivary glands in SD, especially in the presence of other predictors of lymphoproliferation, is a direct indication for biopsy followed by the research to exclude the presence of lymphoma.