Munetoshi Nakashima

Primary Sjögren's syndrome with antibodies to HTLV-I: clinical and laboratory features.

The prevalence of antibodies to human T lymphotropic virus type I (HTLV-I) was studied in patients with primary Sjögrens syndrome. Thirteen of 36 serum samples were positive by enzyme linked immunosorbent assay (ELISA) and particle agglutination assay for antibodies to HTLV-I and were confirmed by western blotting. The presence of antibodies to HTLV-I may signify an HTLV-I carrier state. These patients had a high occurrence of extraglandular manifestations such as uveitis, myopathy, and recurrent high fever compared with patients who did not have antibodies to HTLV-I. Patients with antibodies to HTLV-I had an increased spontaneous proliferation of peripheral blood mononuclear cells compared with those without the antibodies. The proportions of activated and memory T cells (HLA-DR+ CD3+, CD25+ CD3+, and CD29+ CD4+ cells) were higher in HTLV-I carriers than in non-carriers. The presence of antibodies to HTLV-I in some patients with primary Sjögrens syndrome suggests that HTLV-I may cause primary Sjögrens syndrome or its extraglandular manifestations, or both.

Interferon-alpha and dexamethasone inhibit adhesion of T cells to endothelial cells and synovial cells

We investigated whether interferon‐gamma (IFN‐γ), interferon‐alpha (IFN‐α) and glucocorticoids affected the adhesion of T cells to human umbilical endothelial cells or human synovial cells. About 30% of peripheral blood T cells could bind to unstimulated endothelial cells, but only a few T cells could bind to unstimulaled synovial cells. When both endothelial cells and synovial cells were cultured with recombinant IFN‐γ (rlFN‐γ), the percentage of T cell binding to both types of cells increased in a dose‐dependent manner. rIFN‐α and dexamethasone blocked the T cell binding to unstimulated endothelial cells. Furthermore, rIFN‐α and dexamethasone suppressed T cell binding to both endothelial cells and synovial cells stimulated by IKN‐γ, and also inhibited intercellular adhesion molecule‐ l (ICAM‐1) expression on both endothelial cells and synovial cells stimulated by 1 FN‐γ. These results suggest that IFN‐α and glucocorticoids may inhibit T cell binding to endothelial cells or synovial cells by modulating adhesion molecule expression on these cells.

Inhibitory effect of a new anti-rheumatic drug T-614 on costimulatory molecule expression, cytokine production, and antigen presentation by synovial cells.

The present study was undertaken to investigate the immunoregulatory effects of T-614 (3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne) on synovial cells in vitro. Synovial cells were cultured with T-614 in the presence or absence of various cytokines. After incubation, the costimulatory molecule expression on synovial cells and cytokine production in culture supernatants were analyzed by an indirect immunofluorescence method and enzyme-linked immunosorbent assay, respectively. We also examined the effect of T-614 on the function of synovial cells as antigen-presenting cells (APCs). The costimulatory molecules including CD54, CD58, and CD106 were constitutionally expressed on the surface of synovial cells. However, neither CD80 nor CD86 nor CD102 was found on the surface, and these costimulatory molecules could not be induced by any cytokines. T-614 itself did not affect the costimulatory molecule expression and cytokine production of unstimulated synovial cells. The stimulation of synovial cells with interferon-gamma (IFN-gamma), interleukin-1beta, or 12-O-tetradecanoyl phorbol 13-acetate enhanced the expression of costimulatory molecules and the proinflammatory cytokine production of these cells. Both the up-regulated expression of these costimulatory molecules and the enhanced production of proinflammatory cytokines were significantly inhibited by T-614. Autologous T cell proliferation in response to purified protein derivative by IFN-gamma-treated synovial cells was significantly suppressed by T-614. T-614 has considerable immunosuppressive effects on synovial cells by inhibiting the costimulatory molecule expression and cytokine production of these cells and the antigen-specific T cell proliferation mediated by the synovial cells. These results suggest that T-614 plays an important immunoregulatory role in rheumatoid synovial tissues.

Infection of human synovial cells by human T cell lymphotropic virus type I. Proliferation and granulocyte/macrophage colony-stimulating factor production by synovial cells.

The present study was performed to clarify the relationship between human T cell lymphotropic virus type I (HTLV-I) infection and chronic inflammatory arthropathy. To determine the ability of HTLV-I to infect synovial cells and the effect on synovial cell proliferation, synovial cells were cocultured with the HTLV-I-producing T cell lines (MT-2 or HCT-1). After coculture with HTLV-I-infected T cells, the synovial cells expressed HTLV-I-specific core antigens, and HTLV-I proviral DNA was detected from the synovial cells by polymerase chain reaction. These cocultured synovial cells with HTLV-I-infected T cells proliferated more actively than the synovial cells cocultured with uninfected T cells. This stimulatory effect of HTLV-I-infected T cells on synovial cell proliferation seems necessary to contact each other. After being cocultured with MT-2 cells, synovial cells proliferated more actively than control cells even after several passages. Furthermore, HTLV-I-infected synovial cells produced significant amounts of granulocyte/macrophage colony-stimulating factor. These results suggest that HTLV-I can infect synovial cells, resulting their active proliferation and may be involved in the pathogenesis of proliferative synovitis similar to that found in rheumatoid arthritis.

Expression of basic fibroblast growth factor in synovial tissues from patients with rheumatoid arthritis: detection by immunohistological staining and in situ hybridisation.

OBJECTIVE--The distribution and production of basic fibroblast growth factor (bFGF) was examined on the synovium from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS--The localisation of bFGF was determined by an immunohistochemical staining procedure using anti-bFGF monoclonal antibody. The expression of bFGF mRNA was detected by nonradioactive in situ hybridisation using bFGF antisense oligo DNA. RESULTS--The bFGF was found in the synovial lining cell, sublining stromal fibroblast-like cells, and vascular endothelial cells from patients with RA and OA. Little or no bFGF was found in non-inflamed synovium. Immunostaining of bFGF in the synovial cells was more extensive and intense in synovium of patients with RA than that of patients with OA. The nuclei of the synovial lining cell layer were also immunostained. These nuclear staining were more intense in the lining cell layer from RA patients with moderate or severe proliferation of synovial cells than in RA patients with mild proliferation. The bFGF mRNA was also detected in the synovial lining cell layer of the inflamed synovium. CONCLUSION--The synovial lining cells produced bFGF. The proliferation of synovial cells in the inflamed joints may be the results of stimulation by the bFGF in autocrine manner.

Mechanism of inhibitory effect of dextran sulfate and heparin on human T-cell lymphotropic virus type I (HTLV-I)-induced syncytium formation in vitro: role of cell-to-cell contact.

Cell-to-cell contact is usually essential for syncytium formation by HTLV-I-infected cell lines. The present study was undertaken to determine the inhibitory effect of polyanionic compounds, dextran sulfate and heparin, on HTLV-I-induced syncytium formation, as demonstrated by the fusion of HTLV-I-infected cells with target cells. These two compounds almost completely blocked syncytium formation in the early phase of the reaction at a concentration of 125 micrograms/ml, but dextran, as a control, did not inhibit it at concentrations up to 625 micrograms/ml. 50% inhibition of syncytium formation was detected at a concentration of 2 micrograms/ml of dextran sulfate 5000, 3 micrograms/ml of dextran sulfate 8000 and 8 micrograms/ml of heparin. The binding of radiolabeled HTLV-I-infected cells (HCT-1) to the target cells was inhibited by addition of dextran sulfate and heparin, and the inhibitory effects were concentration-dependent. No marked changes were detected in the expression of adhesion molecules on the virus-infected cells and target cells, and in the expression of envelope proteins on the virus-infected cells after exposing them to the polyanionic compounds. These results suggest that the blocking of cell-to-cell contact by polyanionic compounds, probably independent of surface adhesion molecules, is important for their inhibitory effect on HTLV-I-induced syncytium formation.

The contribution of SAA1 polymorphisms to Familial Mediterranean fever susceptibility in the Japanese population.

Background/Aims Familial Mediterranean Fever (FMF) has traditionally been considered to be an autosomal-recessive disease, however, it has been observed that substantial numbers of patients with FMF possess only 1 demonstrable MEFV mutation. The clinical profile of familial Mediterranean fever (FMF) may be influenced by MEFV allelic heterogeneity and other genetic and/or environmental factors. Methodology/Principal Findings In view of the inflammatory nature of FMF, we investigated whether serum amyloid A (SAA) and interleukin-1 beta (IL-1β) gene polymorphisms may affect the susceptibility of Japanese patients with FMF. The genotypes of the -13C/T SNP in the 5′-flanking region of the SAA1 gene and the two SNPs within exon 3 of SAA1 (2995C/T and 3010C/T polymorphisms) were determined in 83 Japanese patients with FMF and 200 healthy controls. The same samples were genotyped for IL-1β-511 (C/T) and IL-1 receptor antagonist (IL-1Ra) variable number of tandem repeat (VNTR) polymorphisms. There were no significant differences between FMF patients and healthy subjects in the genotypic distribution of IL-1β -511 (C/T), IL-1Ra VNTR and SAA2 polymorphisms. The frequencies of SAA1.1 allele were significantly lower (21.7% versus 34.0%), and inversely the frequencies of SAA1.3 allele were higher (48.8% versus 37.5%) in FMF patients compared with healthy subjects. The frequency of -13T alleles, associated with the SAA1.3 allele in the Japanese population, was significantly higher (56.0% versus 41.0%, p = 0.001) in FMF patients compared with healthy subjects. Conclusions/Significance Our data indicate that SAA1 gene polymorphisms, consisting of -13T/C SNP in the 5′-flanking region and SNPs within exon 3 (2995C/T and 3010C/T polymorphisms) of SAA1 gene, are associated with susceptibility to FMF in the Japanese population.

Expression of adhesion molecule ICAM-1 (CD54) in thyroid papillary adenocarcinoma

The expression of adhesion molecules in thyroid specimens from 10 cases of papillary adenocarcinoma, 5 cases of follicular adenoma and 3 normal thyroid specimens was examined by an immunohistochemical method. Thyroid epithelial cells from all cases of papillary adenocarcinoma expressed the intercellular adhesion molecule 1 (ICAM-1, CD54). The ICAM-1-positive staining in these was detected predominantly on the apical site of malignant thyroid epithelial cells. However, no ICAM-1 expression was detected on thyrocytes of adenoma, and normal thyroid tissues. Furthermore, thyroid epithelial cells in patients with thyroid tumor and normal thyroid tissue did not react with anti-LFA-1, anti-VLA-4, anti-VCAM-1 and anti-ELAM-1 monoclonal antibodies. It is speculated that ICAM-1 expression in thyroid papillary adenocarcinoma may have a functional significance.

Interleukin 4 increases human synovial cell expression of VCAM-1 and T cell binding.

OBJECTIVE--The effects were studied of interleukin 4 (IL-4) on T cell-synovial cell adhesion and on the expression of adhesion molecules on the surface of synovial fibroblast-like cells. METHODS--The adhesion of T cells toward the synovial cells were measured by 51chromium-labelled adhesion assay. The expression of adhesion molecules on synovial cells were analysed by flowcytometry. RESULTS--Stimulation of synovial cells with IL-4 increased T cell-synovial cells adhesion in a time- and dose-dependent manner. IL-4 considerably enhanced the expression of VCAM-1 on the surface of synovial cells, but not the expression of ICAM-1 and ELAM-1. The combination of IL-1 beta and IL-4 had no effect on the expression of ICAM-1 or VCAM-1 on the surface of synovial cells. The increased adhesion of T cells to IL-4 stimulated synovial cells was inhibited significantly by adding anti-VCAM-1 or anti-CD29 monoclonal antibody. Furthermore, anti-VLA-4 alpha or the combination of anti-VLA-4 alpha and anti-VCAM-1 antibodies blocked completely T-cell binding to IL-4 stimulated synovial cells. CONCLUSIONS--These results suggest that the increased adhesion of T cells to IL-4-stimulated synovial cells is mediated by VLA-4/VCAM-1 pathway.

Increased prevalence of MEFV exon 10 variants in Japanese patients with adult-onset Still's disease.

Autoinflammatory diseases include a large spectrum of monogenic diseases, e.g. familial Mediterranean fever (FMF), as well as complex genetic trait diseases, e.g. adult‐onset Stills disease (AOSD). In populations where FMF is common, an increased MEFV mutation rate is found in patients with rheumatic diseases. The aim of this study was to examine MEFV mutations in Japanese patients with AOSD. Genomic DNA was isolated from 49 AOSD patients and 105 healthy controls, and exons 1, 2, 3 and 10 of the MEFV gene genotyped by direct sequencing. MEFV mutation frequencies in AOSD patients were compared with controls. We found no significant difference in overall allele frequencies of MEFV variants between AOSD patients and controls. However, MEFV exon 10 variants (M694I and G632S) were significantly higher in AOSD patients than controls (6·1 versus 0%). In addition, there was no significant difference between MEFV variant carriers and non‐carriers with clinical manifestations, but the monocyclic clinical course of the AOSD disease phenotype was observed less frequently in patients without MEFV variants. AOSD patients had significantly higher frequencies of MEFV exon 10 mutations, suggesting that low‐frequency variants of MEFV gene may be one of the susceptibility factors of AOSD.