Sjögren's syndrome: immunobiology of exocrine gland dysfunction

Evaluation of the potential of Ergostatrien-3β-ol for treating Sjögren's syndrome

AIM

Ergostatrien-3β-ol (EK100) is a bioactive compound found in the fruiting bodies and mycelia of Antrodia cinnamomea and has anti-inflammatory and immunomodulatory properties. This study aims to evaluate the potential of EK100 as a treatment for Sjögren's syndrome (SS).

METHODS

We employed a spontaneous SS model in non-obese diabetic (NOD)/Ltj mice to assess the therapeutic potential of EK100. The effects of EK100 were evaluated based on stimulated salivary flow rates, sialadenitis, expression of inflammatory cytokines in salivary glands, and profiles of T cell subsets in the spleen. Additionally, in vitro experiments were conducted to assess the impact of EK100 on Th17 cell differentiation and dendritic cell (DC) maturation.

RESULTS

EK100 treatment significantly increased salivary flow rates, suppressed lymphocyte infiltration, and decreased the concentrations of anti-SSA/Ro and anti-SSB/La autoantibodies. EK100 also downregulated the expression of various inflammatory cytokines in the salivary glands and reduced the populations of Th1 and Th17 cells in the spleens of NOD/Ltj mice. In vitro experiments confirmed that EK100 inhibited the differentiation of Th17 cells and the maturation of DCs.

CONCLUSION

Our findings suggest that EK100 may offer a promising therapeutic avenue for the treatment of SS by modulating the interaction between Th17 cells and DCs.

Phosphorylated signal transducer and activator of transcription proteins 1 in salivary glandular tissue: an important histological marker for diagnosis of primary Sjögren's syndrome

OBJECTIVES

The pathological diagnostic criteria for primary Sjögren's syndrome (SjS) have certain limitations. We first explored the key pathogenic pathways of SjS through a bioinformatics approach, and then evaluated the diagnostic value of the important biomarker in SjS.

METHODS

Transcriptome data from non-SjS controls and patients with SjS were analysed using integrated bioinformatics methods. In a case-control study, phosphorylated signal transducer and activator of transcription proteins 1 (p-STAT1), a key biomarker for the activation of interferon (IFN) pathway, was selected to evaluate its diagnostic value by immunohistochemical analyses in salivary gland (SG) tissues.

RESULTS

The IFN-related pathways were aberrantly activated in patients with SjS. Positive staining of p-STAT1 was detected in the SjS group, but not in non-SjS control group. There was a significant difference in the integrated optical density values of p-STAT1 expressions between the controls and the SjS groups, as well as between the controls and the SjS lymphatic foci-negative groups (p<0.05). The area under the curve of the receiver operating characteristic curve for p-STAT1 was 0.990 (95% CI 0.969 to 1.000). There was a significant difference in both accuracy and sensitivity of p-STAT1 compared with the Focus Score (p<0.05). The Jorden index for p-STAT1 was 0.968 (95% CI 0.586 to 0.999).

CONCLUSIONS

The IFN pathway is the key pathogenic pathway in SjS. p-STAT1 may serve as an important biomarker, in addition to lymphocytic infiltration, to diagnose SjS. Particularly in SG samples with negative lymphatic foci, p-STAT1 confers pathological diagnostic value.

Herbal Formula SS-1 Increases Tear Secretion for Sjögren's Syndrome

Background: Sjögren’s syndrome (SS) is an autoimmune inflammatory disease that primarily affects the exocrine glands, leading to glandular dysfunction. The hallmark symptoms of SS are dry eyes and mouth, compromising the quality of life of patients and decreasing their capacity to perform their daily activities.

Objective: This study aims to evaluate the efficacy of the herbal formula SS-1 for its potential therapeutic benefits for patients with Sjögren’s syndrome.

Materials and Methods: The bioactivity profile of SS-1 was determined using four different SS-1 concentrations across 12 human primary cell systems of the BioMAP profile. After that, a randomized, double-blind, crossover, placebo-controlled trial was performed including 57 patients treated with SS-1 for 28 weeks.

Results: Biologically multiplexed activity profiling in cell-based models indicated that SS-1 exerted anti-proliferative activity in B cells and promoted anti-inflammatory and immunomodulatory activity. In the clinical trial, Schirmer’s test results revealed significant improvements in both eyes, with increases of 3.42 mm (95% CI, 2.44–4.41 mm) and 3.45 mm (95% CI, 2.32–4.59 mm), respectively, and a significant reduction in artificial tear use, which was −1.38 times/day, 95% CI, −1.95 to −0.81 times/day. Moreover, the increases in B-cell activating factor (BAFF) and B-cell maturation antigen (BCMA) levels were dampened by 53.20% (295.29 versus 555.02 pg/ml) and 58.33% (99.16 versus 169.99 pg/ml), respectively.

Conclusion: SS-1 treatment significantly inhibited B-cell maturation antigen. No serious drug-related adverse effects were observed. Oral SS-1 administration may be a complementary treatment for Sjögren’s syndrome.

Effect of the Chinese Herbal Medicine SS-1 on a Sjögren's Syndrome-Like Disease in Mice

Sjögren’s syndrome (SS) is an inflammatory autoimmune disease primarily affecting the exocrine glands; it has a major impact on patients’ lives. The Chinese herbal formula SS-1 is composed of Gan Lu Yin, Sang Ju Yin, and Xuefu Zhuyu decoction, which exerts anti-inflammatory, immunomodulatory, and antifibrotic effects. Our previous study demonstrated that SS-1 alleviates clinical SS. This study aimed to evaluate the efficacy and mechanism of the Chinese herbal formula SS-1 for salivary gland protein-induced experimental Sjögren’s syndrome (ESS). These results showed that ESS treatment with the Chinese herbal formula SS-1 (1500 mg/kg) significantly alleviated the severity of ESS. We found that SS-1 substantially improved saliva flow rates in SS mice and ameliorated lymphocytic infiltrations in submandibular glands. In addition, salivary gland protein-induced SS in mice treated with SS-1 significantly lowered proinflammatory cytokines (including IFN-γ, IL-6, and IL-17A) in mouse salivary glands and decreased serum anti-M3R autoantibody levels. In addition, we found that CD4+ T cells isolated from SS-1-treated SS mice significantly reduced the percentages of IFN-γ-producing CD4+ T cells (Th1) and IL-17A-producing CD4+ T cells (Th17). Our data show that SS-1 alleviates ESS through anti-inflammatory and immunomodulatory effects, which provides new insight into the clinical treatment of SS.

Effect of Myd88 deficiency on gene expression profiling in salivary glands of female non-obese diabetic (NOD) mice

OBJECTIVES

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by inflammatory lesions in the salivary and lacrimal glands, which are caused by distinct lymphocytic infiltrates. Female non-obese diabetic (NOD) mice spontaneously develop inflammatory lesions of the salivary glands with SS-like pathological features. Previous studies have shown that MyD88, a crucial adaptor protein that activates innate immune signaling, affects lymphocytic infiltration, but its detailed role remains unclear. In this study, we investigated the role of MyD88 through gene expression profiling in the early phase of pathogenesis in the salivary glands of female NOD mice.

METHODS

Submandibular glands collected from 10-week-old female wild-type and Myd88-deficient NOD mice were used for RNA preparation, followed by microarray analysis. The microarray dataset was analyzed to identify Myd88-dependent differentially expressed genes (DEGs). Data generated were used for GO enrichment, KEGG pathway, STRING database, and INTERFEROME database analyses.

RESULTS

Myd88 deficiency was found to affect 230 DEGs, including SS-associated genes, such as Cxcl9 and Bpifa2. Most of the DEGs were identified as being involved in immunological processes. KEGG pathway analysis indicated that the DEGs were putatively involved in autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. Furthermore, the DEGs included 149 interferon (IFN)-regulated genes.

CONCLUSIONS

MyD88 is involved in the expression of specific genes associated with IFN-associated immunopathological processes in the salivary glands of NOD mice. Our findings are important for understanding the role of MyD88-dependent innate immune signaling in SS manifestation.

Ocular surface characteristics in acne vulgaris

Clinical relevance: Since acne vulgaris is a disease of the sebaceous glands, it may have potential effects on the ocular surface and tear homoeostasis, which are essential for good vision. Optometrists should be aware of ocular surface pathologies when prescribing glasses or contact lenses for the visual rehabilitation of these young patients.Background: To evaluate the ocular surface features, meibomian glands, and tear parameters of patients with acne vulgaris.Methods: The right eyes of 70 individuals (34 patients with acne vulgaris, 36 healthy volunteers) were evaluated. The tear break-up time of participants was measured, and the Schirmer test was performed. Then, to determine ocular surface characteristics, samples were taken from the conjunctiva for impression cytology. Finally, the loss rates of the upper and lower eyelid meibomian glands were determined by taking meibography (Sirius, CSO, Florence, Italy).Results: Tear break-up time was significantly lower in the study group compared to the control group (p < 0.001). No statistically significant difference was determined between the groups in respect of Nelson grade in the conjunctival impression cytology (p = 0.141). Grade 3 cytological changes were not observed in either group. The median value of the loss rate in the meibomian glands in the upper eyelid of patients with acne vulgaris was 19.10% (IQR: 18%), while it was 8.75% (IQR: 9.53%) in the control group (p = 0.001). The median value of the loss rate in the meibomian glands in the lower eyelid was 15.70% (IQR: 15.13%) and 7.70% (IQR: 6.53%) in the acne vulgaris and control groups, respectively (p < 0.001).Conclusion: Our study shows that patients with acne vulgaris may have a predisposition to meibomian gland damage and tear instability. Therefore, we consider that a more detailed ophthalmologic examination should be performed in patients with acne vulgaris.

A randomized controlled study to evaluate an experimental moisturizing mouthwash formulation in participants experiencing dry mouth symptoms

OBJECTIVE

The aim of this study was to evaluate the efficacy and tolerability of an experimental moisturizing mouthwash versus water only in participants experiencing dry mouth symptoms, including those with Sjögren syndrome (n = 28).

STUDY DESIGN

Participants were randomized to the experimental mouthwash group (n = 53) or the water-only group (n = 47). For 8 days, the mouthwash group used 1 to 2 doses/day at home; both groups could sip water, as needed. Supervised treatment occurred on days 1, 3, and 8, and during this treatment, before and after administration, participants completed the Product Performance and Attributes Questionnaire parts 1 through 4.

RESULTS

Significant between-treatment differences on all Product Performance and Attributes Questionnaire questions were shown at most time points. On day 8, at 120 minutes, there was a significant difference on Product Performance and Attributes Questionnaire 3-Question 1 ("Relieves the discomfort of dry mouth"; the predefined primary efficacy variable) in favor of mouthwash versus water (0.63 [95% confidence interval 0.17-1.10]; P = .0084). Subgroup analysis found a significant difference that favored mouthwash in participants without Sjögren syndrome (0.67 [0.11,1.23]; P = .0203) but not with Sjögren syndrome (0.52 [-0.35,1.38; P = .2272). Eight, non-serious, oral treatment-related adverse events were reported by the mouthwash group.

CONCLUSIONS

The findings of a subjective questionnaire showed that an experimental moisturizing mouthwash provided greater relief than water only from dry mouth symptoms over 8 days.

Sjögren's syndrome, the old and the new

Sjögren's syndrome is a chronic autoimmune disease characterised by progressive injury to exocrine glands accompanied by diverse extra-glandular manifestations. The spectrum of Sjögren's manifestations expanded in recent years to include new symptoms and signs such as small fibre neuropathy, and also well-defined activity and prognostic indexes. Similar to other non-organ-specific autoimmune diseases, a mosaic of factors have been linked with the development and appearances of Sjögren's syndrome. Progress has been made unravelling those factors, including susceptibility genes, immunological parameters and various environmental factors in the last decade, some of which may enable targeted therapies, biological and non-biological ones, for patients suffering from this disease. Thus, herein we review the postulated aetiologies, pathogenesis and new insights related to Sjögren's syndrome.

Modeling Sjögren's syndrome with Id3 conditional knockout mice

The Id3 gene has been shown to play important roles in the development and function of broad tissue types including B and T cells. Id3 deficient mice develop autoimmune disease similar to human Sjögren's syndrome. Both B and T lymphocytes have been implicated to contribute to the disease phenotype in this disease model. In order to gain a better understanding of individual cell types in this disease model, we generated an Id3 conditional allele. An LckCre transgene was used to induce Id3 deletion in developing T cells. We showed that the Id3 gene was efficiently disrupted in early thymocyte development prior to T cell receptor (TCR)-mediated positive selection. Consequently, thymocyte maturation was impaired in the conditional knockout mice. These mice developed exocrinopathy starting at two months of age and subsequently exhibited high incidence of lymphocyte infiltration to salivary glands between eight and 12 months of age. This progressive feature of disease development is very similar to those observed in Id3 germline knockout mice. This study establishes a new model for investigating the relationship between T cell development and autoimmune disease. Our observation provides an experimental case that autoimmune disease may be induced by acquired mutation in developing T cells.

Pathogenic mechanisms in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease characterized by the dysfunction of T cells, B cells, and dendritic cells and by the production of antinuclear autoantibodies. This editorial provides a synopsis of newly discovered genetic factors and signaling pathways in lupus pathogenesis that are documented in 11 state-of-the-art reviews and original articles. Mitochondrial hyperpolarization underlies mitochondrial dysfunction, depletion of ATP, oxidative stress, abnormal activation, and death signal processing in lupus T cells. The mammalian target of rapamycin, which is a sensor of the mitochondrial transmembrane potential, has been successfully targeted for treatment of SLE with rapamycin or sirolimus in both patients and animal models. Inhibition of oxidative stress, nitric oxide production, expression of endogenous retroviral and repetitive elements such as HRES-1, the long interspersed nuclear elements 1, Trex1, interferon alpha (IFN-alpha), toll-like receptors 7 and 9 (TLR-7/9), high-mobility group B1 protein, extracellular signal-regulated kinase, DNA methyl transferase 1, histone deacetylase, spleen tyrosine kinase, proteasome function, lysosome function, endosome recycling, actin cytoskeleton formation, the nuclear factor kappa B pathway, and activation of cytotoxic T cells showed efficacy in animal models of lupus. Although B cell depletion and blockade of anti-DNA antibodies and T-B cell interaction have shown success in animal models, human studies are currently ongoing to establish the value of several target molecules for treatment of patients with lupus. Ongoing oxidative stress and inflammation lead to accelerated atherosclerosis that emerged as a significant cause of mortality in SLE.

Emerging new pathways of pathogenesis and targets for treatment in systemic lupus erythematosus and Sjogren's syndrome

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) and Sjogren's syndrome are chronic inflammatory diseases characterized by the dysfunction of T cells, B cells, and dendritic cells and the production of antinuclear autoantibodies. Here, we evaluate newly discovered molecular and cellular targets for the treatment of SLE and Sjogren's syndrome.

RECENT FINDINGS

The mammalian target of rapamycin in T and B cells has been successfully targeted for treatment of SLE with rapamycin or sirolimus both in patients and animal models. Inhibition of oxidative stress, nitric oxide production, interferon alpha, toll-like receptors 7 and 9, histone deacetylase, spleen tyrosine kinase, proteasome function, lysosome function, endosome recycling, and the nuclear factor kappa B pathway showed efficacy in animal models of lupus. B-cell depletion and blockade of anti-DNA antibodies and T-B cell interaction have shown success in animal models, whereas human studies have so far failed to accomplish clinical endpoints, possibly due to inadequacies in study design.

SUMMARY

Discovery of novel genes and signaling pathways in lupus pathogenesis offers novel biomarker-targeted approaches for treatment of SLE and Sjogren's syndrome.

Amelioration of lacrimal gland inflammation by oral administration of K-13182 in Sjögren's syndrome model mice

Regulation of the adhesion of mononuclear cells to endothelial cells is considered to be a critical step for the treatment of inflammatory diseases, including autoimmune diseases. K-13182 was identified as a novel inhibitor for these adhesions. K-13182 inhibited the expression of vascular cell adhesion molecule-1 (VCAM-1, CD106) on human umbilical vein endothelial cells (HUVECs) and on mouse vascular endothelial cell line (MAECs) induced by tumour necrosis factor (TNF)-alpha. K-13182 also inhibited the adhesion of mononuclear cells to these HUVECs and MAECs, indicating that K-13182 suppressed these adhesions mediated by cellular adhesion molecules including VCAM-1. To evaluate the therapeutic effect in autoimmune disease model mice, K-13182 was orally administered to non-obese diabetic (NOD) mice as Sjögren's syndrome (SS) model mice. Severe destructive inflammatory lesions were observed in the lacrimal glands of vehicle-treated control mice; however, 8-week administration of K-13182 inhibited the mononuclear cell infiltration into the inflammatory lesions of the lacrimal glands. In K-13182-treated mice, the decrease in tear secretion was also prevented compared to the control mice. In addition, the apoptosis and the expression of FasL (CD178), perforin, and granzyme A was suppressed in the lacrimal glands of K-13182-treated mice. Therefore, K-13182 demonstrated the possibility of therapeutic efficacy for the inflammatory region of autoimmune disease model mice. These data reveal that VCAM-1 is a promising target molecule for the treatment of autoimmune diseases as a therapeutic strategy and that K-13182 has the potential as a new anti-inflammatory drug for SS.

P2Y2 nucleotide receptor activation up-regulates vascular cell adhesion molecule-1 [corrected] expression and enhances lymphocyte adherence to a human submandibular gland cell line

Sjögren's syndrome (SS) is a chronic inflammatory autoimmune disease that causes salivary and lacrimal gland tissue destruction resulting in impaired secretory function. Although lymphocytic infiltration of salivary epithelium is associated with SS, the mechanisms involved have not been adequately elucidated. Our previous studies have shown that the G protein-coupled P2Y2 nucleotide receptor (P2Y2R) is up-regulated in response to damage or stress of salivary gland epithelium, and in salivary glands of the NOD.B10 mouse model of SS-like autoimmune exocrinopathy. Additionally, we have shown that P2Y2R activation up-regulates vascular cell adhesion molecule-1 (VCAM-1) expression in endothelial cells leading to the binding of monocytes. The present study demonstrates that activation of the P2Y2R in dispersed cell aggregates from rat submandibular gland (SMG) and in human submandibular gland ductal cells (HSG) up-regulates the expression of VCAM-1. Furthermore, P2Y2R activation mediated the up-regulation of VCAM-1 expression in HSG cells leading to increased adherence of lymphocytic cells. Inhibitors of EGFR phosphorylation and metalloprotease activity abolished P2Y2R-mediated VCAM-1 expression and decreased lymphocyte binding to HSG cells. Moreover, silencing of EGFR expression abolished UTP-induced VCAM-1 up-regulation in HSG cells. These results suggest that P2Y2R activation in salivary gland cells increases the EGFR-dependent expression of VCAM-1 and the binding of lymphocytes, a pathway relevant to inflammation associated with SS.

Treatment of primary Sjögren's syndrome with low-dose human interferon alfa administered by the oromucosal route: combined phase III results

OBJECTIVE

This study tested the safety and efficacy of human interferon (IFN) alfa for treatment of salivary hypofunction and dry mouth symptoms in primary Sjögren's syndrome patients.

METHODS

Combined results are reported from 2 phase III clinical trials in which a total of 497 subjects with primary Sjögren's syndrome received 150 international units of human IFN alfa or matching placebo 3 times per day for 24 weeks by the oromucosal route.

RESULTS

Subjects given IFN alfa had a significantly (P = 0.01) greater mean increase in unstimulated whole saliva (UWS) flow, compared with subjects given placebo. In IFN alfa patients, increases in UWS correlated positively and significantly with improvements noted in 7 of 8 symptoms associated with oral and ocular dryness. The coprimary endpoints of stimulated whole saliva flow and oral dryness were not significantly improved in the IFN alfa group relative to placebo. No significant differences were found between the groups with respect to overall adverse event incidence or severity.

CONCLUSION

IFN alfa given at low dosage by the oromucosal route can significantly increase UWS flow in patients with primary Sjögren's syndrome, without causing significant adverse events.

Histologic characteristics and local cellular immunity of the gland of the third eyelid after topical ophthalmic administration of 2% cyclosporine for treatment of dogs with keratoconjunctivitis sicca

OBJECTIVE

To evaluate the efficacy of topical administration of a 2% solution of cyclosporine (CsA) for treatment of dogs with keratoconjunctivitis sicca (KCS) and to correlate results with histopathologic characteristics and local cellular immunity of the gland of the third eyelid.

ANIMALS

24 dogs with bilateral KCS.

PROCEDURE

Lacrimal secretion was measured, using Schirmer tear test (STT) strips. Leukocyte and T-lymphocyte subsets were determined in blood samples. Histopathologic changes as well as CD4+, CD8+, and alpha-naphthyl-acetate esterase-positive (ANAE+) lymphocytes were evaluated.

RESULTS

Clinical signs resolved at the end of 1 month in conjunction with significantly increased STT values, compared with baseline values. Fifteen and 30 days after discontinuation of CsA treatment, a decrease was observed in STT values in both eyes; however, only values for the right eye were significantly different. There was a significant decrease in the number of lymphocytes and ANAE+ lymphocytes 15 and 30 days after discontinuation of CsA treatment, compared with baseline values. Differences were not observed in number of CD4+ lymphocytes among treatment groups. However, there was a significant decrease in number of CD8+ lymphocytes with reversal of the CD4+:CD8+ in both eyes after CsA treatment for 30 days, compared with the control group. Increased secretory activity and decreased lymphocyte infiltration were characteristic histopathologic findings.

CONCLUSIONS AND CLINICAL RELEVANCE

Topical administration of a 2% solution of CsA was effective for the treatment of dogs with KCS. Strict follow-up monitoring is required after the cessation of treatment because of the possibility of recurrence of KCS.

Professional antigen presenting cells in minor salivary glands in Sjögren's syndrome: potential contribution to the histopathological diagnosis?

Sjögren's syndrome is an autoimmune disease in which lymphocytic infiltrates develop in the salivary and lacrimal glands. We have shown that dendritic cells (DC) infiltrate the submandibular gland of the nonobese diabetic (NOD) mouse, a mouse model for Sjögren's syndrome, before lymphocytic infiltration, suggesting that these antigen-presenting cells (APC) may play a role in the initiation of Sjögren's syndrome. In later stages, DC and macrophages also form an important part of the infiltrate of the NOD sialoadenitis. To find out if DC and macrophages form part of the infiltrate in Sjögren's syndrome as well, and to determine whether they may be useful in the histopathological diagnosis of Sjögren's syndrome, we studied their presence in minor salivary glands (MSG) of patients with Sjögren's syndrome and patients with focal lymphocytic sialoadenitis (FLS), but without clinical or serological criteria of Sjögren's syndrome. Immunohistochemistry was applied, followed by semiquantitative analysis. DC and macrophages were present in all MSG; however, there were clear differences in marker expression between Sjögren's syndrome and FLS, on the one hand, and control tissue, on the other hand. CD1a+ DC and RFD9+ macrophages were mainly observed in MSG in which a focal lymphocytic infiltrate was present. In fact, the diffuse presence of single CD1a+ DC and RFD9+ macrophages correlated closely with the presence of a focal lymphocytic infiltrate in the MSG. This indicates that these cells could be of help during the evaluation of a MSG. Because the detection of APC is technically less cumbersome than a focal score, this parameter may perhaps replace the focal score in the histopathological diagnosis of Sjögren's syndrome. This study therefore prompts further investigation focusing on the presence of CD1a+ and RFD9+ cells in the MSG of a large cohort of patients.

Interferon-mediated block in cell cycle and altered integrin expression in a differentiated salivary gland cell line (HSG) cultured on Matrigel

Sjögren's syndrome (SS), an idiopathic, autoimmune exocrinopathy, is partly characterized by diminished salivary flow, acinar cell atrophy, and increased expression of several cytokines. Several in vivo characteristics of the sialoadenitis are also evident in a human salivary gland ductal epithelial cell line (HSG) treated with cytokines. HSG cells differentiate to the acinar phenotype when cultured on Matrigel (Becton Dickinson, Bedford, MA), a basement membrane extract. To elucidate mechanisms of salivary gland pathology, the effects of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) on cell cycle progression and integrin expression were evaluated in HSG acinarlike cells. Flow cytometry experiments showed that cytokine treatment for 2 days arrested cells in G(1) phase of the cell cycle, and this preceded significant morphologic changes and decreased viability. Whereas only modest cytokine-mediated increases in protein expression for the alpha 3 and beta 1 integrin subunits were seen by immunoprecipitation, a form of alpha 3 integrin displaying enhanced electrophoretic mobility was evident after 6 days of cytokine treatment. To our knowledge, this is the first report demonstrating an IFN-mediated alteration in the electrophoretic mobility of integrin subunits. From this study, it was evident that the combination of IFN-gamma and TNF-alpha resulted in a block in G(1) phase for acinar cells before accumulation of the alpha 3 integrin variant or significant degenerative cellular changes. Information from the present and previous studies suggests that cytokines may alter the pattern of integrin expression and block cell cycle progression in salivary gland cells grown in three-dimensional acinarlike clusters. These experiments may provide a new cell culture model to study the effects of cytokines in normal and diseased salivary glands, including SS.

MHC class II molecules, cathepsins, and La/SSB proteins in lacrimal acinar cell endomembranes

Sjögren's syndrome is a chronic autoimmune disease affecting the lacrimal glands and other epithelia. It has been suggested that acinar cells of the lacrimal glands provoke local autoimmune responses, leading to Sjögren's syndrome when they begin expressing major histocompatibility complex (MHC) class II molecules. We used isopycnic centrifugation and phase partitioning to resolve compartments that participate in traffic between the basolateral membranes and the endomembrane system to test the hypothesis that MHC class II molecules enter compartments that contain potential autoantigens, i.e., La/SSB, and enzymes capable of proteolytically processing autoantigen, i.e., cathepsins B and D. A series of compartments identified as secretory vesicle membranes, prelysosomes, and microdomains of the trans-Golgi network involved in traffic to the basolateral membrane, to the secretory vesicles, and to the prelysosomes were all prominent loci of MHC class II molecules, La/SSB, and cathepsins B and D. These observations support the thesis that lacrimal gland acinar cells that have been induced to express MHC class II molecules function as autoantigen processing and presenting cells.

Treatment of primary Sjögren's syndrome with low-dose natural human interferon-alpha administered by the oral mucosal route: a phase II clinical trial. IFN Protocol Study Group

The purpose of this investigation was to examine the safety and efficacy of four dosages of natural human interferon-alpha (nHuIFN-alpha) delivered over a 12-week period orally in lozenges (150 IU and 450 IU, once [QD] or three times [TID] daily) compared to placebo in subjects with primary Sjögren's syndrome. This randomized, double-blinded clinical trial demonstrated that nHuIFN-alpha at a dose of 150 IU administered TID by oral lozenge significantly improved stimulated whole saliva output compared to placebo after 12 weeks of treatment. The 150 IU TID dose also was suggestive of benefit for 5 of 7 subjective measures of oral and ocular comfort. IFN lozenges demonstrated a good safety profile, with no serious adverse events found in any treatment group. There were no significant differences between the placebo and the four doses of IFN for adverse events by total number, organ system, severity, dropouts, and number judged to be related to treatment. In conclusion, these results demonstrated that the use of 150 IU IFN lozenges TID for 12 weeks in subjects with primary Sjögren's syndrome improved salivary output and decreased complaints of xerostomia without causing significant adverse medical events.