Lymphocytic Infiltration Of Salivary Glands Research Articles

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.

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.

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.

Treatment of Sjögren's Syndrome with Mesenchymal Stem Cells: A Systematic Review.

Mesenchymal stem cells (MSCs) are ubiquitous in the human body. Mesenchymal stem cells were initially isolated from bone marrow and later from other organs such as fatty tissues, umbilical cords, and gingiva. Their secretory capacities give them interesting immunomodulatory properties in cell therapy. Some studies have explored the use of MSCs to treat Sjögren’s syndrome (SS), a chronic inflammatory autoimmune disease that mainly affects exocrine glands, including salivary and lacrimal glands, although current treatments are only palliative. This systematic review summarizes the current data about the application of MSCs in SS. Reports show improvements in salivary secretions and a decrease in lymphocytic infiltration in salivary glands in patients and mice with SS after intravenous or infra-peritoneal injections of MSCs. MSC injections led to a decrease in inflammatory cytokines and an increase in anti-inflammatory cytokines. However, the intrinsic mechanism of action of these MSCs currently remains unknown.

POS0790 RELATIONSHIPS BETWEEN SALIVA IMMUNOGLOBULINS FREE LIGHT CHAINS CONCENTRATION AND CLINICAL, IMMUNOLOGICAL, HISTOLOGICAL PARAMETERS IN PATIENT WITH PRIMARY SJOGREN’S SYNDROME

Background:Patients with primary Sjogren’s syndrome (pSS) exhibit biological signs of B cell activation such as serum polyclonal hypergammaglobulinaemia, increased levels of free light chains (FLC) and positivity for autoantibodies. B-cells may comprise up to 50% cells of lymphocytic infiltrates in salivary glands of patents with the disease. For that reasons measuring saliva B-cells products might have diagnostic value in pSS.Objectives:To evaluate relationships between saliva free light chains concentration and clinical, immunological, histological parameters in patient with pSS.Methods:Saliva and blood FLC concentrations were measured in patient with pSS (n = 24) and healthy volunteers (n = 11). Patients fulfilled the ACR/EULAR 2016 criteria of pSS. Saliva collected during assessment unstimulated salivary flow was used for analysis. Quantitative assessment of CD3+, CD4+, CD8+, CD20+, CD21+, CD68+, CD138+ cells was performed in minor salivary glands of 9 patient by immunohistochemistry. Cells quantity was calculated in 4 mm2 (area of section).Results:FLC concentration in saliva of pSS patients was higher than in healthy volunteers (p<0,01). Medians of saliva κ - and λ – free light chains concentrations in patients and healthy persons were 1,08 mg/L [25-;75- percentiles 0,58;1,91], 1,038 mg/L [0,55;2,03] and 0,36 mg/L [0,32; 0,54], 0,35 mg/L [0,21; 0,52] respectively. Median of saliva κ: λ chains ratio in pSS patient was 0,94 [0,6;1,5]. The ratio didn’t differ from healthy persons (p=0,24). Saliva κ – and λ – free light chain concentrations in patient with pSS correlated with patients age (rs= 0,51, p=0,033 and rs=0,43, p= 0,011, respectively) and unstimulated salivary flow (rs= -0,48, p=0,02 and rs=-0,49, p= 0,017, respectively). Concentration of κ – free light chain correlated with number of CD138+-cells (rs= 0,733, p=0,025). Interesting that saliva λ – free light chain concentration didn’t correlate with quantity of plasmatic cells.Conclusion:Measuring saliva FLC concentration might be offered as diagnostic marker of pSS. Concentration κ – free light chain can directly mirror the glands quantity of plasmatic cells.

Periodontal conditions in patients with Sjögren's syndrome: A meta-analysis

Sjögren's syndrome (SS) is a chronic autoimmune rheumatic disease characterized by a progressive lymphocytic infiltration of salivary glands, resulting in xerostomia and other oral diseases. The pathogenesis and mechanisms of SS on periodontal tissues are not well understood. Furthermore, results of two systemic reviews and meta-analyses in which compared periodontal parameters of patients with SS to healthy subjects were different. To determine whether periodontal conditions in SS were different from healthy controls, we re-examined the issue with a random-effect model, avoiding recruiting active controls and inadequate data conversion. Outcome measures included probing pocket depth (PPD), clinical attachment loss (CAL), plaque index (PI), and gingival index (GI). Recruited individuals comprised 198 patients with SS and 180 subjects for healthy controls. Quantitative analysis revealed higher PI (WMD = 0.76, 95% CI: 0.30, 1.23) and GI (WMD of total = 0.50, 95% CI: 0.01, 0.98) in SS patients who were not categorized into primary or secondary types of SS. PPD and CAL in SS patients was comparable with control subjects. However, heterogeneity was observed among included studies. Thus, results from this and previous analyses should be interpretated carefully, and a well-designed observational study regarding this issue should be conducted.

Interleukin-7/Interferon Axis Drives T Cell and Salivary Gland Epithelial Cell Interactions in Sjögren's Syndrome.

Primary Sjögren's syndrome (SS) is characterized by a lymphocytic infiltration of salivary glands (SGs) and the presence of an interferon (IFN) signature. SG epithelial cells (SGECs) play an active role in primary SS pathophysiology. We undertook this study to examine the interactions between SGECs and T cells in primary SS and the role of the interleukin-7 (IL-7)/IFN axis. Primary cultured SGECs from control subjects and patients with primary SS were stimulated with poly(I-C), IFNα, or IFNγ. T cells were sorted from blood and stimulated with IL-7. CD25 expression was assessed by flow cytometry. SG explants were cultured for 4 days with anti-IL-7 receptor (IL-7R) antagonist antibody (OSE-127), and transcriptomic analysis was performed using the NanoString platform. Serum IL-7 level was increased in patients with primary SS compared to controls and was associated with B cell biomarkers. IL7R expression was decreased in T cells from patients with primary SS compared to controls. SGECs stimulated with poly(I-C), IFNα, or IFNγ secreted IL-7. IL-7 stimulation increased the activation of T cells, as well as IFNγ secretion. Transcriptomic analysis of SG explants showed a correlation between IL7 and IFN expression. Finally, explants cultured with anti-IL-7R antibody showed decreased IFN-stimulated gene expression. These results suggest the presence of an IL-7/IFNγ amplification loop involving SGECs and T cells in primary SS. IL-7 was secreted by SGECs stimulated with type I or type II IFN and, in turn, activated T cells that secrete type II IFN. An anti-IL-7R antibody decreased the IFN signature in T cells in primary SS and could be of therapeutic interest.

Transcriptome Sequencing Reveals Potential Roles of ICOS in Primary Sjögren's Syndrome.

Primary Sjögren’s syndrome (pSS) is a chronic systemic autoimmune disease characterized by exocrine gland damage and extraglandular involvements. To identify potential biomarkers for the early detection of pSS and to further investigate the potential roles of the biomarkers in the progression of pSS, our previous RNA sequencing data and four microarray data of salivary glands (SGs) were combined for integrative transcriptome analysis between pSS and non-pSS. Differential gene expression analysis, gene co-expression network analysis, and pathway analysis were conducted to detect hub genes, which were subsequently investigated in peripheral blood mononuclear cell (PBMC) and plasma. Correlation analysis, single-gene Gene Set Enrichment Analysis, and receiver operating characteristic (ROC) curve were applied to investigate the potential function of the hub genes and their classification capacity for pSS. A total of 51 common up-regulated genes were identified among different pSS cohorts. A key module was found to be the most closely linked to pSS, which was significantly associated with inflammation-related pathways. Seven overlapped hub genes (ICOS, SELL, CR2, BANK1, MS4A1, ZC3H12D, and CCR7) were identified, among which ICOS was demonstrated to be involved in most crucial immune pathways. ICOS was up-regulated not only in SGs but also in PBMC and plasma in pSS, and the expression of ICOS was closely associated with lymphocytic infiltration in SGs and disease activity of pSS patients. It showed a strong classification capacity with classic clinical index in SGs (ROC curve 0.9821) and significant distinct discrimination in PBMC (ROC curve 0.9107). These findings are expected to gain a further insight into the pathogenesis of pSS and provide a promising candidate for the early detection of pSS.

Disruption of endothelial barrier function is linked with hyposecretion and lymphocytic infiltration in salivary glands of Sjögren's syndrome

Sjögren's syndrome (SS) is an inflammatory autoimmune disease that causes hyposecretion in salivary glands. Endothelial tight junctions (TJs) play crucial roles in salivation and barrier function of blood vessels. However, whether the alteration of endothelial TJs were involved in pathogenesis of SS was still unknown. Here, the ultrastructure and function of endothelial TJs in submandibular glands (SMGs) were detected by transmission electron microscopy and in vivo paracellular permeability assay in different aged NOD mouse model for SS. CFSE-labeled lymphocytes were injected into tail vein to trace the infiltration, while claudin-5 expression and distribution were detected by immunofluorescence, qRT-PCR, and western blot. Results showed that the stimulated salivary flow rate was gradually decreased and lymphocytic infiltration was found as age increased in 12- and 21-week-old NOD mice, but not 7-week-old NOD mice. Blood vessels were dilated, while endothelial TJ width and paracellular tracer transport were increased in 12-week-old NOD mice. Moreover, the injected CFSE-labeled lymphocytes were observed in SMGs of 12-week-old NOD mice. Claudin-5 level was increased and relocalized from the apical portion of neighboring endothelial cells to lateral membranes and cytoplasm in 12-week-old NOD mice. Additionally, the alteration of claudin-5 expression and distribution was further confirmed in labial salivary glands and bilateral parotid glands from SS patients. In cultured human microvessel endothelial cell line (HMEC-1), IFN-γ stimulation significantly increased claudin-5 expression. Taken together, we identified that the endothelial TJ barrier was disrupted and contributed to the development of salivary hyposecretion and lymphocytic infiltration in SS.

New Murine Model of Early Onset Autoimmune Thyroid Disease/Hypothyroidism and Autoimmune Exocrinopathy of the Salivary Gland

Sixty to seventy percent of IFN-γ(-/-) NOD.H-2h4 mice given sodium iodide (NaI)-supplemented water develop a slow onset autoimmune thyroid disease, characterized by thyrocyte epithelial cell (TEC) hyperplasia and proliferation (H/P). TEC H/P develops much earlier in CD28(-/-) mice and nearly 100% (both sexes) have severe TEC H/P at 4 mo of age. Without NaI supplementation, 50% of 5- to 6-mo-old CD28(-/-)IFN-γ(-/-) mice develop severe TEC H/P, and 2-3 wk of NaI is sufficient for optimal development of severe TEC H/P. Mice with severe TEC H/P are hypothyroid, and normalization of serum thyroxine levels does not reduce TEC H/P. Activated CD4(+) T cells are sufficient to transfer TEC H/P to SCID recipients. Thyroids of mice with TEC H/P have infiltrating T cells and expanded numbers of proliferating thyrocytes that highly express CD40. CD40 facilitates, but is not required for, development of severe TEC H/P, as CD40(-/-)IFN-γ(-/-)CD28(-/-) mice develop severe TEC H/P. Accelerated development of TEC H/P in IFN-γ(-/-)CD28(-/-) mice is a result of reduced regulatory T cell (Treg) numbers, as CD28(-/-) mice have significantly fewer Tregs, and transfer of CD28(+) Tregs inhibits TEC H/P. Essentially all female IFN-γ(-/-)CD28(-/-) NOD.H-2h4 mice have substantial lymphocytic infiltration of salivary glands and reduced salivary flow by 6 mo of age, thereby providing an excellent new model of autoimmune exocrinopathy of the salivary gland. This is one of very few models where autoimmune thyroid disease and hypothyroidism develop in most mice by 4 mo of age. This model will be useful for studying the effects of hypothyroidism on multiple organ systems.

Aging and Immunopathology in Primary Sjögren's Syndrome.

Sicca complaints (sensation of dry mouth and/or eyes) are present in about a quarter of the individuals above the age of 65 years old and are mainly due to medication. However, physiological changes that occur during aging might also lead to a diminished glandular function. These age-related changes are, at least in part, to be the consequence of decreased androgen levels. In addition to these physiological effects that occur during normal aging, sicca complaints can also be caused by Sjögren's syndrome (SS): a systemic auto-inflammatory disorder mainly affecting exocrine glands. Genetic factors, lowered levels of gonadal hormones and (viral) infections appear to contribute to the etiology of the syndrome. The incidence of SS is higher among aged individuals, which might be due to earlier diagnosis, as the onset of SS in an individual with age-related exocrine gland dysfunction lowers the threshold for sicca complaints. On the other hand, physiological aging might be considered as a risk factor for development of SS, resulting in a faster development of the syndrome. Differentiating physiological sicca complaints from SS in the elderly can be challenging, since apparently healthy individuals might present with auto-antibodies and lymphocytic infiltrates in salivary glands might be present as well. The drop in the level of androgens and estrogens upon aging, immunosenescence and pro-inflammatory features of the aging immune system may all contribute to the etiology of pSS in the elderly. In this review, we describe the physiological effects of aging and the influence of SS on exocrine gland morphology and function.

Physiopathologie du syndrome de Gougerot-Sjögren primitif

Primary Sgögren's syndrome (SSP) is one of the most common connective tissue disorder with an estimated prevalence between 0.6 and 1.7% of the general population. Lymphocytic infiltration of salivary gland is easily accessible favoring the diagnosis, and clinical and fundamental research. However, while many advances have been obtained in the recent decades, the pathophysiology of SSP remains unclear combining environmental factors with genetic predisposition. A central role tends to be attributed to salivary gland epithelial cells, originally designated as “innocent bystanders” and to B cells through the intervention of survey factors like BAFF. New T cells subsets are also carefully studied, particularly natural T regulatory and Th17 cells. They could indeed represent new therapeutic targets.

Th1 and Th2 polymorphisms in Sjögren's syndrome and rheumatoid arthritis

Sjogren's syndrome is characterized by T-cell infiltration of exocrine glands leading to parenchymal destruction and impaired glandular function. This process is orchestrated by cytokines, whose secretion can be regulated by genetic polymorphisms. The aim of this study was to investigate the influence of interleukin-6 -174G/C, interleukin-10 -1082G/A, tumor necrosis factor-α -308G/A, interferon-γ +874A/T gene polymorphisms in (RA) and secondary Sjögren's syndrome (sSS). A study sample that comprised of 138 Brazilian patients was divided into three groups: RA (n = 66), sSS (n = 20), and healthy controls - C (n = 52). Patients were subjected to Schirmer's test, unstimulated salivary flow rate, biopsy of minor salivary glands, and serological tests for diagnosing SS. Genomic DNA was obtained from saliva samples and submitted to genotyping. The association between genotypes/alelle frequency and SS susceptibility was tested, as well as their association with clinical features of SS. Tumor necrosis factorα (TNFα)-308GA polymorphisms differed significantly between AR, SS, and C patients (P = 0.008). IL-6 overall G carriers and TNFα A carriers had a higher risk of presenting SS (P = 0.021). IL-6 polymorphism distribution was also distinctive regarding lymphocytic infiltration at the minor salivary glands (P = 0.026) and Schirmer's test (P = 0.035). These results suggest that IL-6 -174GC and TNFα-308GA gene polymorphisms are associated with susceptibility to SS. Additionally, IL-6 polymorphism could influence lymphocytic infiltration of salivary glands and diminish lachrymal gland function.

CCX-CKR deficiency alters thymic stroma impairing thymocyte development and promoting autoimmunity

AbstractThe atypical chemokine receptor CCX-CKR regulates bioavailability of CCL19, CCL21, and CCL25, homeostatic chemokines that play crucial roles in thymic lymphopoiesis. Deletion of CCX-CKR results in accelerated experimental autoimmunity induced by immunization. Here we show that CCX-CKR deletion also increases incidence of a spontaneous Sjögren's syndrome-like pathology, characterized by lymphocytic infiltrates in salivary glands and liver of CCX-CKR−/− mice, suggestive of a defect in self-tolerance when CCX-CKR is deleted. This prompted detailed examination of the thymus in CCX-CKR−/− mice. Negatively selected mature SP cells were less abundant in CCX-CKR−/− thymi, yet expansion of both DP and immature SP cells was apparent. Deletion of CCX-CKR also profoundly reduced proportions of DN3 thymocyte precursors and caused DN2 cells to accumulate within the medulla. These effects are likely driven by alterations in thymic stroma as CCX-CKR−/− mice have fewer cTECs per thymocyte, and cTECs express the highest level of CCX-CKR in the thymus. A profound decrease in CCL25 within the thymic cortex was observed in CCX-CKR−/− thymi, likely accounting for their defects in thymocyte distribution and frequency. These findings identify a novel role for CCX-CKR in regulating cTEC biology, which promotes optimal thymocyte development and selection important for self-tolerant adaptive immunity.

Mesenchymal Stromal Cells Improve Salivary Function and Reduce Lymphocytic Infiltrates in Mice with Sjögren's-Like Disease

BackgroundNon-obese diabetic (NOD) mice develop Sjögren's-like disease (SS-like) with loss of saliva flow and increased lymphocytic infiltrates in salivary glands (SGs). There are recent reports using multipotent mesenchymal stromal cells (MSCs) as a therapeutic strategy for autoimmune diseases due to their anti-inflammatory and immunomodulatory capabilities. This paper proposed a combined immuno- and cell-based therapy consisting of: A) an injection of complete Freund's adjuvant (CFA) to eradicate autoreactive T lymphocytes, and B) transplantations of MSCs to reselect lymphocytes. The objective of this was to test the effectiveness of CD45−/TER119− cells (MSCs) in re-establishing salivary function and in reducing the number of lymphocytic infiltrates (foci) in SGs. The second objective was to study if the mechanisms underlying a decrease in inflammation (focus score) was due to CFA, MSCs, or CFA+MSCs combined.Methodology/Principal FindingsDonor MSCs were isolated from bones of male transgenic eGFP mice. Eight week-old female NOD mice received one of the following treatments: insulin, CFA, MSC, or CFA+MSC (combined therapy). Mice were followed for 14 weeks post-therapy. CD45−/TER119− cells demonstrated characteristics of MSCs as they were positive for Sca-1, CD106, CD105, CD73, CD29, CD44, negative for CD45, TER119, CD11b, had high number of CFU-F, and differentiated into osteocytes, chondrocytes and adipocytes. Both MSC and MSC+CFA groups prevented loss of saliva flow and reduced lymphocytic infiltrations in SGs. Moreover, the influx of T and B cells decreased in all foci in MSC and MSC+CFA groups, while the frequency of Foxp3+ (Treg) cell was increased. MSC-therapy alone reduced inflammation (TNF-α, TGF-β), but the combination of MSC+CFA reduced inflammation and increased the regenerative potential of SGs (FGF-2, EGF).Conclusions/SignificanceThe combined use of MSC+CFA was effective in both preventing saliva secretion loss and reducing lymphocytic influx in salivary glands.

Lack of B and T lymphocyte attenuator exacerbates autoimmune disorders and induces Fas-independent liver injury in MRL-lpr/lpr mice

MRL/Mp-Fas (lpr) (MRL-lpr) mice develop a systemic autoimmune disease and are considered to be a good model for systemic lupus erythematosus in humans. We have recently shown that mice lacking B and T lymphocyte attenuator (BTLA), an inhibitory co-receptor expressed mainly on lymphocytes, on a 129SvEv background spontaneously develop lymphocytic infiltration in multiple organs and an autoimmune hepatitis (AIH)-like disease. In this study, we investigated the role of BTLA in the pathogenesis of autoimmune diseases in MRL-lpr mice. We found that BTLA-deficient (BTLA(-/-)) MRL-lpr/lpr mice developed severe lymphocytic infiltration in salivary glands, lungs, pancreas, kidneys and joints as compared with BTLA-sufficient (BTLA(+/+)) MRL-lpr/lpr mice. In addition, although AIH-like disease was not found in BTLA(+/+) MRL-lpr/lpr mice, AIH-like disease was exacerbated in BTLA(-/-) MRL-lpr/lpr mice as compared with that in BTLA(-/-) 129SvEv mice. These results suggest that BTLA plays a protective role in autoimmune diseases in MRL-lpr mice and that AIH-like disease develops in BTLA(-/-) mice even in the absence of Fas-dependent signaling.

Pathogenesis of Sjögren's syndrome and therapeutic consequences

To summarize recent findings on new pathogenic mechanisms of interaction between genetic and environmental factors and between innate and adaptive immunity in primary Sjögren's syndrome and to reconcile pathogenesis and treatment by focusing on the crucial pathogenic steps that could be targeted by emerging therapies. Regarding genetic predisposition, the functional relevance of IRF5 and STAT4 gene polymorphisms in the activation of type I interferon pathways has been demonstrated. It has also been shown that the isolated stimulation of innate immunity in mice can result in dryness, which precedes lymphocytic infiltrates in salivary glands. In animal models, possible environmental triggers of the disease, such as oestrogen deficiency and/or infection by Epstein-Barr virus, can lead to innate immune followed by autoimmune epithelitis. The IFN-BAFF-B lymphocyte pathogenic axis is, therefore, targeted by numerous drugs currently in evaluation. The development of consensus disease activity scores and patient-related outcomes might help to initiate new controlled trials. The first positive randomized controlled trial with rituximab has been recently published. Hopefully, persistent and joint efforts by many teams to improve the knowledge on the pathogenesis of the disease may allow identification of new therapeutic targets in Sjögren's syndrome.

A role of immune response to M3 muscarinic acethylcholine receptor in the pathogenesis of Sjoegren's syndrome

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic infiltration of salivary glands, in which CD4(+) T cells are predominant. These infiltrating T cells play a crucial role in the generation of SS. Previous studies showed that autoantibodies and auto-reactive T cells against M3 muscarinic acethylcholine receptor (M3R) were detected in patients with SS. In this study, to reveal the pathological mechanisms underlying immune response against M3R, we tried to induce SS like sialoadenitis. M3R knockout (M3R(-/-)) mice were immunized with murine M3R peptides. Their splenocytes were isolated and transferred into Rag1 knockout (Rag1(-/-)) mice. Mononuclear cells infiltration was detected in salivary glands of Rag1(-/-) mice inoculated splenocytes of M3R(-/-) mice immunized with M3R peptides. Moreover we transferred CD3(+) cells from splenocytes of M3R(-/-) mice immunized with M3R peptides into Rag1(-/-) mice. In their salivary glands, mononuclear infiltration was also detected. These findings suggest that the immune response to M3R plays a crucial role in the generation of SS like sialoadenitis.

99mTc-IL2 scintigraphy for early detection of lymphocytic infiltration of salivary glands in patients with an autoimmune disease

99mTc-IL2 scintigraphy for early detection of lymphocytic infiltration of salivary glands in patients with an autoimmune disease

Cell Adhesion Molecules: A Selective Therapeutic Target for Alleviation of IDDM

Selective homing of autoreactive lymphocytes to the pancreatic islets of Langerhans is essential for triggering the cascade of molecular and cellular interactions which culminate in the specific destruction of the insulin-producing beta-cells. Based upon the sequential multistep model of lymphocyte adhesion to the endothelium, we investigated the possibility of preventing the progression of insulin-dependent diabetes mellitus (IDDM) by selectively blocking L-selectin and alpha 4-integrin homing receptors, which function at different stages of the adhesion process. Treatment of NOD mice with mAb specific for L-selectin or alpha 4-integrin resulted in a significant inhibition of lymphocytic infiltration (insulitis). Both spontaneous development and acute transfer of IDDM were completely prevented by administration of anti-alpha 4-integrin antibody and partially inhibited by anti-L-selectin antibody. The protective effect was of long duration. Interestingly, the autoimmune T cell responses to a panel of beta cell autoantigens and the lymphocytic infiltration of salivary glands (sialadenitis) appeared unaffected by anti-L-selectin or anti-alpha 4-integrin treatment. These data suggest that prevention of lymphocyte homing to the pancreatic islets may provide a selective target for prevention/treatment of IDDM in patients.