Involvement of apoptotic protease cascade for tissue destruction in Sjögren's syndrome.

Sjögren syndrome (SS) is an autoimmune disease characterized by diffuse lymphoid cell infiltrates in the salivary and lacrimal glands, resulting in symptoms of dry mouth and eyes due to insufficient secretion. Although it has been assumed that a combination of immunologic, genetic and environmental factors may play a key role in the development of autoimmune lesions in the salivary and lacrimal glands, little is known about the disease pathogenesis of SS in humans. We have identified the 120 kDa alpha-fodrin as an important autoantigen in the development of SS in both an animal model and SS patients, but the mechanism of alpha-fodrin cleavage leading to tissue destruction in SS remains unclear.

Mechanisms of neonatal tolerance induced in an animal model for primary Sjögren's syndrome by intravenous administration of autoantigen.

Neonatal exposure to autoantigen is believed to induce effective antigen-specific T-cell tolerance in experimental models of autoimmunity. We have identified 120 kDa alpha-fodrin autoantigen in an animal model for primary Sjögren's syndrome (SS), that has been determined as a candidate autoantigen in both an animal model and the patients with primary SS. We demonstrate here that neonatal injection of autoantigen induce relevant tolerance when treated with intravenous (i.

Autoantigen-specific CD4+CD28low T cell subset prevents autoimmune exocrinopathy in murine Sjögren's syndrome.

Organ-specific autoimmune exocrinopathy resembling Sjögren's syndrome (SS) that spontaneously develops in NFS/sld mutant mice thymectomized 3 day after birth is dependent on Th1-type CD4+ T cells. We previously reported that a cleavage product of 120-kDa alpha-fodrin may be an important autoantigen in the pathogenesis of SS in both an animal model and the patients. We demonstrate that in an animal model of SS with overt exocrinopathy, a unique CD4+ T cell subset expressing CD28low is dramatically increased in spleen cells before the disease onset, but that the CD4+ T cells of diseased mice were virtually all CD28high.

Severe destructive autoimmune lesions with aging in murine Sjögren's syndrome through Fas-mediated apoptosis.

When we evaluated the age-associated changes in autoimmune exocrinopathy in a NFS/sld murine model for primary Sjögren's syndrome (SS), severe destructive autoimmune lesions developed in the salivary and lacrimal glands in the aged mice, compared with those observed in the younger model. We detected a decreased secretion of saliva and tear flow in the aged group. A significant increase of TUNEL(+)-apoptotic epithelial duct cells in the salivary glands was detected in the aged SS animal model.

Treatment with anti-CD86 costimulatory molecule prevents the autoimmune lesions in murine Sjögren's syndrome (SS) through up-regulated Th2 response.

Intraperitoneal administration with anti-CD86 (B7.2) MoAb into the murine model for primary SS in NFS/sld mutant mice resulted in dramatically inhibitory effects on the development of autoimmune lesions, while no significant effects were observed when the mice were administered with anti-CD80 (B7.1) MoAb.

Estrogen deficiency accelerates autoimmune exocrinopathy in murine Sjögren's syndrome through fas-mediated apoptosis.

Estrogenic action has been suggested to be responsible for the strong female preponderance of autoimmune diseases, but the role of estrogens in the female has not been well characterized. We evaluated the effects of estrogen deficiency in a murine model for autoimmune exocrinopathy of Sjögren's syndrome (SS). Severe destructive autoimmune lesions developed in the salivary and lacrimal glands in estrogen-deficient mice, and these lesions were recovered by estrogen administration.

Requirement for splenic CD4+ T cells in the immune privilege of the anterior chamber of the eye.

Injection of antigen into the anterior chamber of the eye induces suppression of antigen-specific DTH, called anterior chamber-associated immune deviation (ACAID). It has been shown that the spleen is required for the induction of ACAID and detecting the ACAID-inducing signal from the eye. To examine the in vivo role of spleen cells, fractions of spleen cells were adoptively transferred into splenectomized mice.

Anti-120-kDa alpha-fodrin immune response with Th1-cytokine profile in the NOD mouse model of Sjögren's syndrome.

Our recent study suggested that the 120-kDa alpha-fodrin molecule may be an important autoantigen in the pathogenesis of Sjögren's syndrome, and anti-120-kDa alpha-fodrin antibodies have been detected in patients with Sjögren's syndrome. Here we have analyzed anti-120-kDa alpha-fodrin immune responses during development of spontaneous autoimmune sialadenitis in NOD mice as a model of Sjögren's syndrome. We found specific autoantibody production against 120-kDa alpha-fodrin, and its production correlated closely with autoimmune sialadenitis.

Analysis of T cell receptor Vbeta usage in the autoimmune sialadenitis of non-obese diabetic (NOD) mice.

The NOD mouse develops spontaneous autoimmune sialadenitis besides a well characterized T cell-mediated autoimmune insulitis. We used reverse transcriptase-polymerase chain reaction (RT-PCR) to analyse the repertoire of T cell receptor (TCR) Vbeta chain genes expressed in the isolated infiltrating cells from affected salivary glands. Immunohistochemical analysis showed that the vast majority of inflammatory infiltrates in the salivary glands were CD4+ Vbeta8+ and CD4+ Vbeta6+ T cells, whereas CD8+ T cells and B220+ B cells were fewer in number.

High incidence of autoimmune dacryoadenitis in male non-obese diabetic (NOD) mice depending on sex steroid.

The NOD mouse develops spontaneous autoimmune lesions in the lacrimal and salivary glands, besides a well characterized T cell-mediated autoimmune pancreatic beta cell lesion. We report unique pathological findings developed in the lacrimal glands as an autoimmune dacryoadenitis of NOD mice in contrast to those found in the salivary glands and pancreas. A high incidence of autoimmune lesions in the lacrimal glands was observed exclusively in male NOD mice at any age.

Identification of alpha-fodrin as a candidate autoantigen in primary Sjögren's syndrome.

It is unclear whether organ-specific autoantigens are critical for the development of primary Sjögren's syndrome (SS). A 120-kilodalton organ-specific autoantigen was purified from salivary gland tissues of an NFS/sld mouse model of human SS. The amino-terminal residues were identical to those of the human cytoskeletal protein alpha-fodrin.

Accelerated onset of age-related autoimmune lesions in MRL/+ mice by ovariectomy.

MRL/Mp +/+ (MRL/+) mice, not bearing the lpr gene, are known to have age-related autoimmune lesions in several organs such as pancreas, salivary and lacrimal glands at 30-weeks-old or more. In this study, MRL/+ mice were ovariectomized at 4-weeks-old, and their natural histories were analysed. Ovariectomy (Ovx) of MRL/+ mice led to marked acceleration of organ-specific autoimmune lesions exclusively in the salivary and lacrimal glands at 8-weeks-old or more, whereas no significant inflammatory change was observed in the pancreas.

Effector mechanism of experimental autoimmune sialadenitis in the mouse model for primary Sjögren's syndrome.

We have recently established a new animal model for primary Sjögren's syndrome in NFS/sld mutant mice thymectomized 3 days after birth (3dTX) bearing an autosomal recessive gene with sublingual gland differentiation arrest. In this study, we analyze developing mechanisms of experimental autoimmune sialadenitis (EAS) in the mouse model, focusing on local expressions of cytokine and cell adhesion molecule genes by reverse transcriptase-polymeric chain reaction (RT-PCR) and immunohistochemistry, kinetic analysis of splenic lymphocytes expressing activation markers, and I-Aq class-II molecules by flow cytometry (FACS). We found up-regulation of local cytokine genes (IL-1 beta, TNF-alpha, IL-2, IFN-gamma, IL-6, IL-10, IL-12p40) and cell adhesion molecule genes (ICAM-1, LFA-1, CD44, Mel-14) in the salivary glands from mice with EAS by RT-PCR, which were supported by immunohistochemistry.

Mechanism of the development of autoimmune dacryodenitis in the mouse model for primary Sjögren's syndrome.

To elucidate the mechanism of development in autoimmune lacrimal gland disease, we analyzed different aspects of autoimmune dacryoadenitis in a newly established mouse model for primary Sjögren's syndrome, focusing on the local expressions of cytokine genes, and the repertoire of T cell receptor (TCR) V beta genes transcribed within the inflammatory infiltration in the lacrimal glands. We found that the vast majority of inflammatory infiltration into the lacrimal glands were CD4+ V beta 8+ T cells. We detected the up-regulation of local cytokine genes (IL-1 beta, TNF-alpha, IL-2, IFN-gamma, IL-10, IL-12p40) in the lacrimal glands with very early inflammatory lesions by reverse transcriptase (RT)-PCR analysis.

In vivo role of IL-10 and IL-12 during development of Sjögren's syndrome in MRL/lpr mice.

Expression of local cytokine genes including interleukin 10 (IL-10) and IL-12 was analyzed in the salivary gland tissues of MRL/lpr mice with Sjögren's syndrome. We demonstrate a significant role of IL-10 and IL-12 in vivo during development of Sjögren's syndrome in MRL/lpr mice. IL-10 mRNA expression was detected before the onset of disease and was upregulated during the course of autoimmune sialadenitis by RT-PCR.

Expression of HLA-DR and cytokine genes on interferon-gamma-stimulated human salivary gland cell line.

Stimulation of a cultured human salivary gland (HSG) cell line by interferon (IFN)-gamma leads to HLA-DR gene expression concomitant with inflammatory cytokine genes such as IL-1 beta, tumor necrosis factor (TNF)-alpha, and IL-6 in vitro. IFN-gamma-induced HLA-DR mRNA expression was clearly detected at 2 h after the stimulation, and thereafter its level of gene expression increased until day 7 on HSG cells by reverse transcriptase (RT)-PCR. Immunofluorescence analysis revealed that cytoplasmic HLA-DR immunoreactivity was detected for the first time at 2 days after the stimulation, and its immunoreactivity increased gradually until day 7, while no immunoreactivity with HLA-DP and HLA-DQ was observed at any of the days.

Cytokine gene expression and autoantibody production in Sjögren's syndrome of MRL/lpr mice.

In an attempt to elucidate the mechanism of development of organ-specific autoimmune lesions resembling human Sjögren's syndrome of MRL/lpr mice, we have analyzed local cytokine gene expressions and organ-specific autoantibody production in vivo. We have demonstrated that a major proportion of T cells bearing CD4 and V(beta)8 molecules are essentially responsible for triggering the autoimmunity in the salivary glands of MRL/lpr mice. The local cytokine gene expressions including interferon(IFN)-gamma, IL-12(p40) mRNAs were observed during the course of murine Sjogren's syndrome in MRL/lpr autoimmune strain.

Immunopathological analysis of mucosal melanocyte distribution in the human lower lip of the elderly.

Mucosal melanocyte distribution in the human lower lip was analyzed immunopathologically using a wide selection of 195 surgical specimens. An age-related increase of mucosal melanocyte distribution was observed in the human lower lip by Fontana-Masson argentaffin stain and S-100 protein immunoreactivity. The mean number of mucosal melanocytes increased gradually with advancing age.

Prevention of adoptive transfer of murine Sjögren's syndrome into severe combined immunodeficient (SCID) mice by antibodies against intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1).

We have analysed the role of ICAM-1 and LFA-1 during development of autoimmune sialadenitis in MRL/lpr mice by direct analysis of RNA obtained from the salivary gland tissues, and the therapeutic effects with antibody administration on adoptive transfer system into SCID mice. The expression of cell adhesion molecules was assessed by using reverse transcriptase polymerase chain reaction (RT-PCR) and Southern blot analysis, and immunohistochemical analysis. Up-regulated expression of ICAM-1 mRNA was observed before the onset of inflammatory lesions in the salivary glands at 1 month and 2 months old, and thereafter LFA-1 mRNA was expressed within the typical inflammatory lesions, resembling human Sjögren's syndrome in MRL/lpr mice.

Biased T cell receptor V beta gene usage during specific stages of the development of autoimmune sialadenitis in the MRL/lpr mouse model of Sjögren's syndrome.

Objective: To analyze the repertoire of T cell receptor (TCR) V beta gene transcribed and expressed within the autoimmune lesions of the salivary gland in the MRL/lpr mouse model of Sjögren's syndrome.

Methods: Monoclonal antibodies (MAb) were used to determine the prevalence of selected V gene elements on T cell infiltrates from salivary glands of MRL/lpr mice. To analyze TCR V beta gene usage, we used reverse-transcriptase polymerase chain reaction (RT-PCR) and single-strand conformational polymorphism (SSCP) analyses.

Transfer of Sjögren's syndrome-like autoimmune lesions into SCID mice and prevention of lesions by anti-CD4 and anti-T cell receptor antibody treatment.

We describe the successful transfer of murine Sjögren's syndrome-like autoimmune lesions from MRL/lpr mice (H-2k) to severe combined immunodeficiency (SCID) mice (H-2d) and prevention of lesions by anti-CD4 and -T cell receptor V beta 8 antibody treatment. Mononuclear cells (1 x 10(6)) isolated from the inflamed submandibular salivary gland tissues of MRL/lpr mice were transferred intraperitoneally into SCID mice. Autoimmune lesions resembling those seen in Sjögren's syndrome developed in the salivary and lacrimal glands of SCID mice 8 weeks after the injection, whereas other organs did not show any lesion.

A new animal model for primary Sjögren's syndrome in NFS/sld mutant mice.

In this study, we report an established and characterized animal model for primary Sjögren's syndrome in NFS/sld mutant mice bearing an autosomal recessive gene with sublingual gland differentiation arrest. Significant inflammatory changes develop spontaneously in both the salivary and lacrimal glands of NFS/sld mutant mice thymectomized 3 days after birth without any immunization, whereas no significant inflammatory lesions were found in other organs or in nonthymectomized mice. This pathology resembles primary Sjögren's syndrome in humans, which involves the parotid, submandibular salivary, and lacrimal glands.

Pathogenesis of Sjögren's syndrome-like autoimmune lesions in MRL/lpr mice.

Sjögren's syndrome in humans is a chronic inflammatory disease with a presumed autoimmune etiology of the exocrine organs, involving in particular the salivary and lacrimal glands. The pathogenesis of this syndrome remains unclear, but the majority of infiltrating cells in the salivary glands are CD4+ T cells both in humans and rodents. Since many cytokines are involved in the development of T cell-mediated autoimmunity, local cytokine gene expression was analyzed in vivo using an animal model for Sjögren's syndrome in MRL/lpr mice.

Expressions of cytokine genes during development of autoimmune sialadenitis in MRL/lpr mice.

Local cytokine gene expression in vivo was analyzed by direct analysis of RNA obtained from salivary gland tissues of MRL/lpr mice with autoimmune sialadenitis. The expression of cytokine genes were assessed by the reverse-transcriptase polymerase chain reaction, and by immunohistochemical analysis. The expression of interleukin-1(IL-1)beta and tumor necrosis factor was detected before the onset of inflammatory lesions in the salivary glands of mice of 1 or 2 months of age, and IL-6 mRNA expression was clearly detected at the time of onset of typical autoimmune sialadenitis at 3 months of age in MRL/lpr mice, and was up-regulated with advancing age.