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1.
J Autoimmun ; 39(1-2): 64-8, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22309821

ABSTRACT

Several lines of evidence indicate that salivary gland epithelial cells (SGEC) play an important role in the pathogenesis of primary Sjogren's syndrome (SS). Normal SGEC have been shown to possess functional estrogen receptors, however, the estrogenic response of SGEC in patients with SS has not been previously assessed. To address this issue, we comparatively tested cultured non-neoplastic SGEC lines from SS patients (SS-SGEC, n = 8) and from disease controls (control-SGEC, n = 12) in a standard estrogenic inhibition assay of cytokine-induced adhesion molecule expression, where the modulation of the expression of constitutive and interferon-gamma (IFNγ)-induced CD54/ICAM.1 molecules following treatment with 17ß-estradiol (E2) was evaluated by flow cytometry. Similarly high ICAM.1 expression was induced by IFNγ in control-SGEC and SS-SGEC lines. E2-treatment did not modify the constitutive ICAM.1 expression in either control-SGEC or SS-SGEC lines. In line with previous results, E2-pretreatment of control-SGEC was found to impede significantly the IFNγ-induced upregulation of ICAM.1 (p = 0.003). However, such inhibition was not observed in the SS-SGEC lines (p = 0.55). Such aberrant response of SS-SGEC to estrogens did not appear to associate with altered expression of estrogen receptor (ER) proteins, as no discernible differences could be revealed by immunoblotting and immunohistochemistry in the patterns or the intensity of ERα and ERß (ERß1- and ERß2-isoforms) protein expression in SGEC lines or minor salivary gland tissues between SS patients and disease controls. The deficient estrogenic responsiveness of SS-SGEC likely represents a manifestation of the intrinsic epithelial activation that characterizes SS and possibly indicates the perturbation of the immunoregulatory potential of estrogens in SS-epithelia.


Subject(s)
Epithelial Cells/metabolism , Estradiol/pharmacology , Salivary Glands, Minor/cytology , Salivary Glands, Minor/metabolism , Sjogren's Syndrome/metabolism , Cell Adhesion Molecules/biosynthesis , Cell Line , Humans , Intercellular Adhesion Molecule-1/biosynthesis , Interferon-gamma/metabolism , Receptors, Estrogen/metabolism , Sjogren's Syndrome/immunology
3.
Arthritis Rheum ; 61(8): 1121-9, 2009 Aug 15.
Article in English | MEDLINE | ID: mdl-19644909

ABSTRACT

OBJECTIVE: Myocardium and coronary arteries can occasionally be affected in patients with systemic necrotizing vasculitides; however, such involvement has not been systematically assessed using cardiovascular magnetic resonance imaging (MRI). METHODS: Magnetic resonance angiography and contrast-enhanced MRI were applied for the assessment of coronary arteries (the left anterior descending [LAD], left circumflex [LCx], and right coronary artery [RCA]) and myocardium, respectively, in 39 patients with vasculitis who were asymptomatic for cardiac disease (16 with microscopic polyangiitis [MPA], 11 with Wegener's granulomatosis [WG], 9 with Churg-Strauss syndrome [CSS], and 3 with polyarteritis nodosa [PAN]). Data were compared with age-matched disease-control patients with rheumatoid arthritis (n = 20) or systemic lupus erythematosus (n = 13), and with healthy control individuals with normal coronaries (n = 40). RESULTS: Patients with MPA, WG, and PAN (but not with CSS) were found to display significantly increased maximal diameters of coronary arteries compared with healthy controls (for MPA and WG; P < 0.001 for LAD and RCA, and P < 0.01 for LCx) and with both disease-control groups (for only MPA; P < 0.01 for LAD and RCA, and P < 0.05 for LCx). Fusiform coronary aneurysms were detected in patients with MPA (4/16) and PAN (2/3), whereas coronary ectasias were evident in patients with MPA (14/16) and WG (2/11). The presence of myocardial necrosis (by assessment of late gadolinium-enhanced images) was identified only in patients with MPA (2/16) and CSS (3/8 studied). CONCLUSION: Cardiovascular MRI assessment of patients with systemic vasculitis revealed coronary ectatic disease in the majority of patients with MPA and PAN, as well as in several patients with WG. Myocardial necrosis can be detected in MPA and CSS.


Subject(s)
Churg-Strauss Syndrome/pathology , Coronary Artery Disease/pathology , Coronary Vessels/pathology , Granulomatosis with Polyangiitis/pathology , Magnetic Resonance Imaging/methods , Myocardial Infarction/pathology , Polyarteritis Nodosa/pathology , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/complications , Arthritis, Rheumatoid/pathology , Churg-Strauss Syndrome/complications , Contrast Media/administration & dosage , Coronary Aneurysm/etiology , Coronary Aneurysm/pathology , Coronary Artery Disease/etiology , Dilatation, Pathologic/etiology , Dilatation, Pathologic/pathology , Female , Gadolinium DTPA/administration & dosage , Granulomatosis with Polyangiitis/complications , Humans , Image Enhancement/methods , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/pathology , Male , Middle Aged , Myocardial Infarction/etiology , Polyarteritis Nodosa/complications
4.
Int J Cardiol ; 131(2): e54-5, 2009 Jan 09.
Article in English | MEDLINE | ID: mdl-17707931

ABSTRACT

This case report emphasizes the application of a combined CMR protocol for the diagnosis of acute myocardial inflammation and fibrosis in CSS.


Subject(s)
Churg-Strauss Syndrome/diagnosis , Contrast Media , Magnetic Resonance Imaging , Myocarditis/diagnosis , Aged , Churg-Strauss Syndrome/complications , Female , Humans , Magnetic Resonance Imaging/methods , Myocarditis/complications
5.
Eur Neurol ; 59(3-4): 159-63, 2008.
Article in English | MEDLINE | ID: mdl-18230873

ABSTRACT

BACKGROUND/AIMS: To determine the efficacy of infliximab combined with weekly methotrexate in drug-naive recent-onset dermatomyositis and polymyositis. METHODS: A multicentre open-label controlled trial was conducted. Disease activity was assessed using patient's and physician's disease activity assessment, manual muscle testing (MMT), handheld dynamometry, and serum CK. The primary objective was to assess the efficacy using MMT after a period of 26 weeks. RESULTS: The study was terminated prematurely because of a low inclusion rate and a high drop-out rate due to disease progression and the occurrence of an infusion reaction. The few patients who did reach the primary endpoint showed improvement in all aspects studied. CONCLUSION: Infliximab combined with weekly methotrexate might be safe and well tolerated in a small subgroup of patients with drug-naive recent-onset myositis. At present, we do not advocate the use of this treatment because treatment response cannot be predicted beforehand.


Subject(s)
Antibodies/therapeutic use , Antirheumatic Agents/therapeutic use , Dermatomyositis/drug therapy , Methotrexate/therapeutic use , Polymyositis/drug therapy , Tumor Necrosis Factor-alpha/immunology , Adolescent , Adult , Aged , C-Reactive Protein/metabolism , Drug Therapy, Combination , Evaluation Studies as Topic , Female , Follow-Up Studies , Humans , Middle Aged , Time Factors , Treatment Outcome
6.
Arthritis Rheum ; 56(12): 3977-88, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18050195

ABSTRACT

OBJECTIVE: To evaluate the expression profile of infiltrating macrophages and dendritic cells (DCs) as well as of interleukin-18 (IL-18) and IL-12 in the minor salivary gland (MSG) lesions of patients with Sjögren's syndrome (SS), and to assess the relationship of these factors with disease parameters. METHODS: Macrophages, DCs, T cells, B cells, proIL-18, mature IL-18, and IL-12 were detected by single- and double-labeling immunohistochemistry in MSG specimens from 21 patients with primary SS (13 of 21 tested for IL-12), 7 patients with secondary SS, and 9 disease control patients. Expression profiles were assessed for correlations with various disease parameters, including adverse predictors of lymphoma development. RESULTS: MSGs from patients with SS (but not from disease controls) manifested increased infiltration by macrophages and DCs, strong expression of IL-18 by macrophages (particularly in B cell-rich areas and in germinal center-like structures in primary SS), and expression of IL-12 by mononuclear cell infiltrates. In primary SS, high infiltration by macrophages correlated with SG enlargement (P = 0.01). The DC infiltration rate correlated positively with the macrophage infiltration rate (P = 0.04), occurrence of SG enlargement (P = 0.03), and presence of C4 hypocomplementemia (P = 0.05), and inversely with serum C4 complement levels (P = 0.001). The rate of infiltration by IL-18-expressing cells correlated positively with biopsy focus scores (P < 0.001), larger infiltrates of macrophages (P = 0.01), DCs (P = 0.01), and B cells (P = 0.02), and SG enlargement (P = 0.02), and negatively with serum C4 complement levels (P = 0.02). The rate of infiltration by IL-12-expressing cells correlated inversely with that by IL-18-expressing cells (P = 0.001), biopsy focus scores (P = 0.003), and SG enlargement (P = 0.01), and positively with serum C4 complement levels (P = 0.05). CONCLUSION: In patients with primary SS, infiltration of the SG by macrophages and DCs and expression of IL-18 and IL-12 appear to play active roles in the expansion and organization of infiltrative injuries and have a correlation with certain predictors of lymphoma development.


Subject(s)
Dendritic Cells/pathology , Interleukin-12/metabolism , Interleukin-18/metabolism , Lymphoma/etiology , Macrophages/pathology , Sjogren's Syndrome/complications , Sjogren's Syndrome/metabolism , Adult , Aged , Aged, 80 and over , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Biopsy , Cell Movement , Dendritic Cells/metabolism , Female , Humans , Lymphoma/immunology , Macrophages/immunology , Macrophages/metabolism , Male , Middle Aged , Risk Factors , S100 Proteins/metabolism , Salivary Glands, Minor/metabolism , Salivary Glands, Minor/pathology , Sjogren's Syndrome/pathology
7.
Clin Exp Immunol ; 147(3): 497-503, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17302899

ABSTRACT

Toll-like receptors (TLR) play an essential role in the activation of both innate and adaptive immune responses. Salivary gland epithelial cells (SGEC) may participate in the development of glandular inflammatory reactions that characterize primary Sjögren's syndrome (pSS). In this study we sought to assess the expression and function of several TLR molecules in cultured non-neoplastic SGEC obtained from pSS patients and disease controls. Long-term cultured non-neoplastic SGEC derived from pSS patients (SS-SGEC) and disease controls (control-SGEC), as well as the monocytic cell line THP-1 (positive control cell line), were examined by reverse transcription-polymerase chain reaction (RT-PCR) analysis and quantitative real-time PCR for mRNA expression of TLR1, -2, -3 and -4 molecules. TLR function was assessed by the induction of the expression (flow cytometry) of the immunoregulatory molecules CD54/intercellular adhesion molecule-1 (ICAM-1), CD40, CD86/B7 x 2, major histocompatibility complex (MHC) class I and MHC class II following treatment with the TLR ligands: Staphylococcus aureus peptidoglycan (TLR2), the synthetic dsRNA analogue polyinosinic:cytidylic acid (TLR3) and Escherichia coli lipopolysaccharide (TLR4). SGEC were found to express functional TLR2, -3 and -4 molecules, as attested by dose-dependent up-regulation of surface ICAM-1, CD40 and MHC-I expression (as well as of reciprocal TLR mRNA) following treatment with the respective TLR-ligands. SS-SGEC lines displayed significantly higher constitutive expression of TLR1 (P=0 x 0027), TLR2 (P=0 x 01) and TLR4 (P=0 x 03) mRNA compared to control-SGEC. This study demonstrates that cultured SGEC express functional TLR molecules; the high constitutive TLR expression by SS-SGEC is probably suggestive of the intrinsic activation of epithelial cells in pSS and further supports the role of this type of tissue in pathogenesis of the disorder.


Subject(s)
Salivary Glands/immunology , Sjogren's Syndrome/immunology , Toll-Like Receptors/biosynthesis , Up-Regulation/immunology , Cell Line , Cells, Cultured , Epithelial Cells/immunology , Humans , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Toll-Like Receptors/genetics , Toll-Like Receptors/immunology
10.
J Clin Rheumatol ; 10(4): 162-8, 2004 Aug.
Article in English | MEDLINE | ID: mdl-17043505

ABSTRACT

BACKGROUND: : Infliximab at the dose of 5 mg/kg per infusion has been shown effective for the treatment of active spondyloarthropathies. It is not clear if the 5 mg/kg is required in most patients. OBJECTIVE: : To evaluate the long-term efficacy and safety of infliximab at the lower dose of 3 mg/kg in patients with active and refractory ankylosing spondylitis (AS) and psoriatic arthritis (PsA). METHODS: : Thirty patients were enrolled in a 78-week, single-center, prospective, open-label pilot study, including 16 patients with severe and active AS and 14 patients with active and refractory PsA. Infliximab (3 mg/kg, in combination with a stable dose of methotrexate was administered intravenously at 0, 2 and 6 weeks, and q8 weeks thereafter (schedule-A) and the improvement of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI; for AS patients) and Patient Global Assessment of Disease Activity (PDA; for PsA patients) was monitored at baseline and at every visit (primary variables). Patients who did not respond sufficiently at 14 weeks, as well as patients who relapsed at any time during follow-up, received infliximab every 4 weeks (treatment schedule-B). Three different statistical approaches (per-protocol, last observation carried forward and by intention-to-treat) were applied. RESULTS: : Ten patients discontinued treatment for various reasons, including 3 (10.0%) because of allergic reactions. Twenty patients (66.7%, 9 with AS and 11 with PsA) had completed 78 weeks of treatment (schedule-A, 11 patients; schedule-B, 9 patients). Of these patients, 18 (90.0%) showed optimal response (improvement >/=50%), including 13 (65.0%) with improvement >/=70%. ASsessments in AS (ASAS) 50% was attained by 7/9 AS patients (77.8%). At 78 weeks of treatment, statistically significant improvement of indices of disease activity, function and quality of life was observed by all statistical approaches applied. CONCLUSIONS: : Infliximab at 3 mg/kg every 8 weeks or, if needed, every 4 weeks appears to be an effective and rather safe treatment of patients with active and refractory AS and PsA after 78 weeks of treatment.

12.
Rheumatology (Oxford) ; 42(2): 357-61, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12595636

ABSTRACT

OBJECTIVE: To evaluate whether autoantibodies in the absence of rheumatic diseases increase the risk of mortality among very elderly subjects who are otherwise in good functional condition. METHODS: Autoantibodies were measured in 1987 in 156 elderly nursing home residents (median age 84 yr) who were followed subsequently over 14.6 yr. RESULTS: Eleven subjects had anticardiolipin antibodies, 30 had rheumatoid factor and 19 had antibodies to single-stranded DNA (ssDNA). Other autoantibodies were more rare. During follow-up, 144 subjects died. Adjusting for age as a time-dependent covariate, the hazard ratio for death was 0.71 [95% confidence interval (CI) 0.38-1.32] for anticardiolipin antibodies, 0.93 (95% CI 0.60-1.41) for rheumatoid factor, 1.08 (95% CI 0.65-1.79) for antibodies to ssDNA, and 0.99 (95% CI, 0.70-1.41) for any autoantibody. Hazard ratios were similar when adjusted also for sex and clinical conditions. CONCLUSION: Our results exclude the possibility that the autoantibodies evaluated increase substantially the risk of death among very elderly subjects in good functional condition.


Subject(s)
Aging/immunology , Autoantibodies/blood , Aged , Aged, 80 and over , Antibodies, Anticardiolipin/blood , Antibodies, Antinuclear/blood , Cohort Studies , DNA, Single-Stranded/immunology , Female , Follow-Up Studies , Humans , Male , Proportional Hazards Models , Rheumatoid Factor/blood , Risk Factors , Survival Analysis , Survival Rate
13.
Clin Exp Immunol ; 127(2): 386-92, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11876766

ABSTRACT

CD40 has been identified in an expanding list of haematopoietic and non-haematopoietic cells and has received an increased interest based on its role in a variety of cell-mediated responses and its potential to participate in the pathogenesis of chronic inflammatory disorders. Sjögren's syndrome (SS) is an autoimmune exocrinopathy, which is characterized by chronic lymphocytic infiltration of exocrine glands and aberrant activation of epithelial tissues. We studied the expression of CD40 protein in cultured non-neoplastic salivary gland epithelial cell (SGEC) lines as well as in minor SG biopsies obtained from 17 SS patients and 12 controls. Immunocytochemical and flow cytometric analyses had revealed the occurrence of constitutively expressed CD40 molecules on the surface of long-term cultured SGEC lines, which could be further induced by interferon-gamma (IFN-gamma) and IL-1beta cytokines, but not tumour necrosis factor-alpha (TNF-alpha), IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) or IFN-alpha. Triggering of SGEC through CD40 enhanced the surface expression of the adhesion molecule intercellular adhesion molecule-1 (ICAM-1)/CD54, but not MHC class I and class II (HLA-DR) molecules. Spontaneous CD40 expression was significantly higher in SGEC lines derived from SS patients, compared with controls (P < 0.001), which is suggestive of their intrinsically activated status. In SG biopsies, CD40 was constitutively expressed by lymphocytes, ductal epithelial cells and endothelial cells but not by other glandular cell types, such as acinar cells, myoepithelial cells and fibroblasts. In addition, CD40L staining was also detected in 30--50% of the infiltrating lymphocytes in the biopsies of SS patients. Our findings indicate the immunoregulatory potential of SGEC and lend further support to a model of intrinsic activation in salivary epithelia in SS, whereby these cells actively participate in the induction and maintenance of lymphocytic infiltrates of patients.


Subject(s)
Autoimmune Diseases/metabolism , CD40 Antigens/biosynthesis , Gene Expression Regulation , Salivary Ducts/metabolism , Salivary Glands/metabolism , Sjogren's Syndrome/metabolism , Autoimmune Diseases/genetics , Autoimmune Diseases/pathology , Biopsy , CD40 Antigens/genetics , CD40 Ligand/biosynthesis , CD40 Ligand/genetics , Cells, Cultured/drug effects , Cells, Cultured/metabolism , Cytokines/pharmacology , Endothelium/drug effects , Endothelium/metabolism , Endothelium/pathology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Epithelial Cells/pathology , Female , Gene Expression Regulation/drug effects , HLA Antigens/biosynthesis , HLA Antigens/genetics , Humans , Intercellular Adhesion Molecule-1/biosynthesis , Intercellular Adhesion Molecule-1/genetics , Lymphocytes/drug effects , Lymphocytes/metabolism , Lymphocytes/pathology , Male , Salivary Ducts/drug effects , Salivary Ducts/pathology , Salivary Glands/drug effects , Salivary Glands/pathology , Sjogren's Syndrome/genetics , Sjogren's Syndrome/pathology
15.
J Autoimmun ; 17(2): 141-53, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11591123

ABSTRACT

Sjogren's syndrome (SS) is an exocrinopathy characterized by T cell infiltrates, salivary gland epithelial cell (SGEC) apoptosis and high Fas and FasL expression. To address the participation of T cell-derived cytokines and of Fas apoptotic pathway in SS glandular lesions, we utilized non-neoplastic SGEC lines established from SS patients and controls. Possibly attesting to their intrinsic activation, cell lines derived from SS patients displayed significantly higher constitutive Fas and FasL than controls. Surface co-expression of Fas and FasL was not associated with spontaneous fratricide apoptosis. SGEC were resistant to anti-Fas-mediated apoptosis (possibly owing to the constitutive expression of anti-apoptotic proteins cFLIP and Bcl-2), but became sensitive after protein or RNA synthesis inhibition. IFN-gamma and TNF-alpha were able to upregulate surface Fas and FasL, whereas IL-1beta downregulated surface FasL. IFN-gamma (but not several other cytokines) reduced the survival of SGEC in a dose- and time-dependent manner and induced Fas/FasL-mediated apoptosis, directly and via anoikia. Dexamethasone inhibited the upregulation of Fas and FasL by IFN-gamma and the induction of SGEC apoptosis and detachment by anti-Fas mAb or IFN-gamma. Our findings indicate the injurious role of IFN-gamma for the salivary epithelia of SS patients through the induction of Fas-mediated apoptosis and anoikia.


Subject(s)
Cytokines/metabolism , Epithelial Cells/immunology , Epithelial Cells/pathology , Salivary Glands/immunology , Salivary Glands/pathology , Sjogren's Syndrome/pathology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , fas Receptor/biosynthesis , Antibodies, Monoclonal/metabolism , Apoptosis/drug effects , Apoptosis/immunology , Cell Division , Cells, Cultured , Dexamethasone/pharmacology , Dose-Response Relationship, Immunologic , Epithelial Cells/drug effects , Fas Ligand Protein , Humans , Interferon-gamma/pharmacology , Membrane Glycoproteins/biosynthesis , Membrane Glycoproteins/immunology , Salivary Glands/drug effects , Sjogren's Syndrome/immunology , fas Receptor/immunology , fas Receptor/metabolism
16.
Clin Exp Immunol ; 124(1): 126-33, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11359451

ABSTRACT

ICAM.1 (CD54) is a surface protein expressed on epithelial and other nonhematopoietic cells upon activation and is known to play an important role in the stimulation of T cells by the provision of cellular adhesion and costimulatory support. Sjogren's syndrome (SS) is an autoimmune exocrinopathy, which is characterized by chronic lymphocytic infiltration of exocrine glands and aberrant activation of epithelial tissues. To address the contribution of ICAM.1 in the pathogenesis of SS, the expression of this protein was studied by immunohistochemistry and flow cytometry in minor salivary gland (SG) biopsies as well as in cultured SG epithelial cell (SGEC) lines obtained from 18 SS patients and 16 controls. In biopsies from SS patients (but not controls), strong ICAM.1 was expressed by infiltrating mononuclear cells (52%) and by a significant proportion of periacinar myoepithelial cells (18%). In addition, a patchy pattern of moderate ICAM.1 expression was detected in 31% of ductal epithelia of SS patients. These ICAM.1-expressing epithelial and myoepithelial cells were observed throughout glandular tissues and were not confined in areas proximal to lymphoid infiltrates. In support to an intrinsic activation profile of SGEC in SS, long-term cultured non-neoplastic SGEC lines derived from SS patients displayed significantly upregulated spontaneous expression of ICAM.1, compared to controls (P < 0.05). The high expression of ICAM.1 protein by the salivary epithelium of SS patients is likely suggestive of its important role in the pathogenesis of the disorder. Further, our results support a model of intrinsic activation of salivary epithelial and myoepithelial cells in SS, whereby these cells actively participate in the induction and maintenance of lymphocytic infiltrates of patients.


Subject(s)
Autoimmune Diseases/pathology , Intercellular Adhesion Molecule-1/biosynthesis , Monocytes/metabolism , Salivary Glands, Minor/pathology , Sjogren's Syndrome/pathology , Biopsy , Cells, Cultured , Epithelial Cells/metabolism , Humans , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/pathology , Lymphocyte Function-Associated Antigen-1/analysis , Sjogren's Syndrome/complications
17.
J Immunol ; 166(5): 3107-13, 2001 Mar 01.
Article in English | MEDLINE | ID: mdl-11207262

ABSTRACT

B7 molecules expressed on classic APC play a critical role in the regulation of immune responses by providing activation or inhibitory signals to T cells, through the ligation with CD28 or CTLA4 receptors, respectively. We have recently described the expression of B7 molecules by the salivary gland epithelial cells (SGEC) of patients with Sjögren's syndrome (also termed autoimmune epithelitis). The role of such expression needs to be clarified. Thus, in the present study, we sought to address the existence and function of B7.2 proteins on cultured nonneoplastic SGEC lines derived from Sjögren's syndrome patients. The occurrence of B7.2 proteins on SGEC was verified by flow cytometry, immunocytochemistry, immunoprecipitation, and immunoblotting. The assessment of several cell lines in costimulation assays had revealed that the constitutive expression of B7.2 molecules is sufficient to provide costimulatory signals to anti-CD3-stimulated T cells. SGEC-derived costimulation induced IL-2-dependent proliferation of CD4(+) T cells, which was associated with low production of IL-2, but probably also with the secretion of yet undefined autocrine T cell growth factor(s). B7.2 proteins expressed by SGEC were found to display distinctive binding properties denoted by the functional interaction with CD28 receptor and reduced binding to CTLA4. Finally, the detection of a functional soluble form of B7.2 protein in cell-free culture supernatants of both SGEC and EBV-transformed B cell lines is demonstrated. These findings imply a critical role for epithelial cells in the regulation of local immune responses in the salivary glands.


Subject(s)
Antigens, CD/biosynthesis , Antigens, Differentiation/metabolism , CD28 Antigens/metabolism , Down-Regulation/immunology , Epithelial Cells/immunology , Epithelial Cells/metabolism , Immunoconjugates , Membrane Glycoproteins/biosynthesis , Salivary Glands, Minor/immunology , Salivary Glands, Minor/metabolism , Abatacept , Animals , Antigen-Presenting Cells/immunology , Antigen-Presenting Cells/metabolism , Antigens, CD/genetics , B7-2 Antigen , CD4-Positive T-Lymphocytes/immunology , CHO Cells , CTLA-4 Antigen , Cell Line, Transformed , Cell-Free System/immunology , Cells, Cultured , Cricetinae , Humans , Interleukin-2/physiology , Lymphocyte Activation , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/genetics , Protein Binding/immunology , Signal Transduction/immunology , Transfection
19.
Clin Exp Immunol ; 121(3): 551-6, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10971524

ABSTRACT

The aim of this study was to investigate the immunogenicity of four synthetic peptides, representing linear B cell epitopes of the human La/SSB autoantigen: 145-164 aa (p1), 289-308 aa (p2), 301-318 aa (p3) and 349-364 aa (p4), in rabbits. New Zealand White rabbits were immunized with each of the above peptides attached in four copies on tetrameric sequential oligopeptide carriers (SOC) in duplicate. Control immunizations were also performed (one rabbit each, immunized with Freud's complete adjuvant alone or with the SOC carrier alone). Animals were bled at regular intervals and sera were analysed for anti-La/SSB activity by ELISA assays using as antigen the various synthetic peptides, as well as the whole La/SSB protein. Four months after the last immunization, the animals were killed and peripheral blood mononuclear and spleen cells were co-cultured with either the peptides, the SOC carrier, or 27 peptides, covering the entire length of the human La/SSB molecule (23 amino acids long, overlapping by eight residues to each other). A specific, IgG, anti-peptide antibody response was detected, initially directed against the priming peptide, and subsequently expanded to the other La/SSB synthetic peptides. The antibody titres remained high, even 4 months after the last immunization. Sera from rabbits immunized with either p2 or p3 reacted also with the whole La/SSB protein, as was demonstrated by ELISA and immunoblot assays. No reactivities against either Ro60 or Ro52 autoantigen were found. Rabbit spleen cell reacted not only with the epitope used for the immunization but also with other La/SSB peptides. Immunization of rabbits with the major human La/SSB B cell antigenic determinants, linked to SOC carrier, induces strong and sustained antibody and T cell responses against multiple epitopes of the human La/SSB protein. Thus, La/SSB B cell linear epitopes are probably capable also of functioning as T cell epitopes, in this experimental animal.


Subject(s)
Autoantigens/immunology , Immunoglobulin G/biosynthesis , Ribonucleoproteins/immunology , T-Lymphocytes/immunology , Amino Acid Sequence , Animals , Antibody Specificity , Autoantigens/administration & dosage , Autoantigens/genetics , Cross Reactions , Epitopes/administration & dosage , Epitopes/genetics , Epitopes/immunology , Humans , Immunization , In Vitro Techniques , Lymphocyte Activation , Molecular Sequence Data , Peptide Fragments/administration & dosage , Peptide Fragments/genetics , Peptide Fragments/immunology , Rabbits , Ribonucleoproteins/administration & dosage , Ribonucleoproteins/genetics , SS-B Antigen
20.
Article in English | MEDLINE | ID: mdl-10882215

ABSTRACT

Sjögren's syndrome (SS) is a chronic autoimmune disorder of the exocrine glands of unknown aetiology, which is typically associated with focal lymphocytic infiltrates of glandular tissues and autoantibody responses against the Ro(SSA) and La(SSB) ribonucleoproteins. In almost one-third of patients disease involves various extraglandular sites, whereas approximately 5% of patients may also develop malignant B-cell lymphoma. In addition, features of SS are frequently encountered (5-20%) in patients with several other autoimmune rheumatic diseases, and in several respects these 'secondary' forms may be distinct from SS found alone (primary-SS), as well as from each other. The correct diagnosis and management of SS may require consideration from various specialists. Differential diagnosis includes adverse effects of drugs, sarcoidosis, lipoproteinaemias, age-related atrophy, chronic graft-versus-host disease, lymphomas, amyloidosis and infection by human immunodeficiency virus or hepatitis C virus. Based on the sequential application of the validated European classification criteria for SS, a practical algorithm for diagnosis is presented. Despite progress in the understanding of the broad clinicopathological spectrum of the entity, its treatment remains largely empirical and symptomatic. To date, the decision for systemic therapeutic intervention is primarily based on the severity of extraglandular manifestations.


Subject(s)
Sjogren's Syndrome/diagnosis , Sjogren's Syndrome/therapy , Diagnosis, Differential , Humans , Immune System/physiopathology , Lymphoproliferative Disorders/etiology , Sjogren's Syndrome/complications , Sjogren's Syndrome/immunology
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