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Notes: Abstract. The aim of the present investigation was to study the expression of specific α/β T cell receptor (TCR) gene products in relation to some microbiological and immunological features of advanced destructive periodontitis, 21 individuals with advanced periodontal disease (diseased group) and 16 age- and sex-matched healthy subjects (healthy group) were recruited. Following a clinical examination of the diseased group, the 3 deepest interproximal sites in the upper and lower premolar- or molar segments (i.e., 12 sites in each individual) were selected for further analysis. Samples from the subgingival microbiota were obtained from the pocket of the selected sites and were prepared for a microbiological examination. The gingival tissue at one of the selected sites was also biopsied. Each excised soft tissue specimen was divided into 2 equal portions. One portion of the biopsy was prepared for histometric and morphometric analyses. The 2nd portion was snap frozen and prepared for immunohistochemical analysis, A sample of peripheral blood was obtained from each individual of the diseased and the healthy group and prepared for immunohistochemical analysis. The selected sites of the diseased group harbored varying numbers of microorganisms which have been associated with periodontal disease. The excised gingival tissue contained inflammatory lesions with substantial numbers of lymphocytes and plasma cells including T- and B-cells and a TCR Vα/β gene repertoire dominated by Vβ 17. The TCR profile of the lesion, however, differed markedly from that of the circulating blood of the diseased subjects. While only minor differences were observed between the blood samples of the diseased and the healthy subjects regarding the TCR genes, CD5, HLA-DR and CD5+CD19 positive cells occurred in higher proportions in the blood samples of the subjects susceptible to periodontal disease than in healthy controls. It may be suggested that (i) TCR Vα/Vβ expression in peripheral blood samples of subjects with periodontal disease does not differ from that of healthy individuals, and (ii) the periodontal lesion expresses a unique TCR repertoire in which the Vβ 17 gene dominates.

Notes: The most frequent pathogen in haematogenously acquired kidney infections in humans is Staphylococcus aureus. In order to characterize in situ the immunological patterns of septic nephritis we developed a murine model of this disease. A single intravenous injection of S. aureus producing toxic shock syndrome toxin-1 resulted in high frequency of inflammatory kidney lesions. Histopathologically, both focal and diffuse inflammatory infiltrates were seen in kidney cortex and medulla. Immunohistochemical evaluation revealed high numbers of Mac-1+ phagocytic cells as well as CD4+- and CD8+-lymphocytes. The expansion of lymphocytes carrying T-cell receptor Vβ chain 4, 7, and 11 families in the kidney was observed. Our results suggest that the haematogenously acquired kidney infection by superantigen-producing staphylococci leads to migration, in situ activation and expansion of responding T-lymphocyte subsets.

Notes: The aim of the present study was to analyse possible differences in immunological features between patients with primary and secondary Sjögren's syndrome (SS). Ten patients with primary SS and 10 patients with secondary SS also suffering from rheumatoid arthritis, were identified according to established criteria for SS. Ten healthy, age-matched women served as controls. The authors analysed the phenotypic characteristics of lymphocytes in peripheral blood as well as in focal inflammatory infiltrates of minor salivary gland biopsies. Functional analyses of T lymphocytes were performed after stimulation with mitogens and antigen. B cell activity was determined at the single cell level by spontaneous and mitogen induced immunoglobulin production. Serum levels of IL-4, IL-6 and IFN-γ were also analysed. Patients with primary SS displayed a significantly higher degree of salivary gland inflammation and reduced salivary flow than did patients with secondary SS. Decreased in vitro T cell responses to antigen and mitogens were evident in both patient groups. The CD4/CD8 ratios in both peripheral blood and salivary gland lesions were significantly lower in primary SS compared with secondary SS patients. Polyclonal B cell activation, measured as the frequency of spontaneous immunoglobulin producing cells, was most prominent in primary SS, whereas a diminished response to poke-weed mitogen (PWM), a T cell dependent B cell mitogen, was more pronounced in secondary SS. The results reveal certain immunological aberrations in the whole group of patients with SS. In addition, the authors demonstrated distinct differences in immune dysfunction between patients with primary and secondary SS, indicating that they may constitute separate entities.

Notes: Hyaluronanreceptor (CD44) has been shown to be involved in lymphocyte homing during normal leucocyte circulation and during leucocyte extravasation into sites of tissue inflammation. In addition, interaction with CD44 molecule induces T-cell activation and production of cytokines, such as interferon-γ. In this study we have examined what influence interaction with the CD44 receptor would have on collagen II-induced arthritis in mice. Mice were immunized with rat collagen II and administered with injections of a monoclonal anti-CD44 antibody. Seventeen days after the outbreak of the disease, all of the anti-CD44 treated animals remained clinically healthy, whereas 37% of the controls displayed arthritis (P〈0.001). Ten days later the prevalence of arthritis was 26% and 65% (P〈0.05), respectively. Furthermore, the severity of the arthritis was significantly ameliorated by the anti-CD44 treatment. Serum levels of interferon-γ were significantly higher in collagen II immunized animals having been treated with anti-CD44, compared to the controls. Delayed-type hypersensitivity (DTH) response was significantly decreased in the anti-CD44 treated animals, indicating a functional suppression of T cells. In contrast, T cell independent experimental inflammation was not affected by the administration of CD44 antibodies. Our results suggest that interaction with CD44 down-regulates T lymphocyte/monocyte mediated inflammatory reaction, possibly by triggering of interferon-γ release.

Notes: The importance of the MHC class II region for the development of septic arthritis was studied in a murine model of haematogenously induced Staphylococcus aureus arthritis. In the first experiment MHC class II deficient mice (Aβ−/−) and their heterozygous (Aβ+/−) littermates were intravenously inoculated with a single dose of toxic shock syndrome toxin-1 producing S. aureus LS-1 strain. The results demonstrate that the expression of class II MHC molecules increases the prevalence and severity of arthritis. To analyse the impact of MHC class II haplotypes on the disease onset and progression the authors used congenic C3H.NB, C3H.Q and C3H/HeJ mice in the second set of experiments. The results show that C3H/HeJ mice developed the highest frequency and the most severe course of arthritis compared with C3H.NB and C3H.Q animals. Immunohistochemical analysis of arthritic joints revealed equal number of macrophages, CD4+ and CD8+ lymphocytes in the inflamed synovia in all the congenic mice. In contrast, the number of MHC class II expressing cells was higher in the arthritic joints of C3H/HeJ mice compared with the congenic strains (P〈0.001). Furthermore, serum levels of proarthrtitogenic cytokines, such as tumour necrosis factor and interleukin-6 were higher in C3H/HeJ group. This study indicates that MHC class II expression is necessary for the development of S. aureus arthritis in mice and that different MHC class II haplotypes confer varying susceptibility for development of joint inflammation induced by staphylococci.

Notes: The effect of combined antibiotic and corticosteroid treatment on the course of haematogenously acquired Staphylococcus aureus nephritis was studied. Mice were given a single injection of S. aureus producing toxic shock syndrome toxin-1 in a dose capable of inducing a high frequency of inflammatory kidney lesions and divided into three groups according to a treatment regimen. In all untreated animals inflammatory infiltrates were seen in kidney cortex and medulla with high frequencies of glomerular (90%) and tubular damage (50%) as well as fibrotic changes (50%). The treatment with antibiotics alone reduced significantly only the occurrence of focal inflammatory infiltrates. In contrast, the mice treated with a combination of antibiotics and corticosteroids displayed in 64% of cases normal histological kidney appearance and a significant decrease in occurrence of glomerular (P〈0.01) and tubular (P〈0.05) lesions. Immunohistochemically, the combined treatment resulted in a more pronounced decrease in numbers of CD4, IL-2R (four to fivefold) and CD8 positive cells in kidney inflammatory lesions compared to antibiotics only treated group. Thus, glucocorticoids in association with antibiotics are shown to improve the outcome of septic murine nephritis, possibly due to suppression of kidney infiltrating T cells.

Notes: Inclusion body myositis (IBM) is a chronic, progressive inflammatory myopathy. The inflammatory infiltrates are dominated by T cells, which frequently invade muscle fibres. The present study was performed to characterize the usage of the variable (V)segment of the T-cell receptor of muscle infiltrating cells in IBM. Using the reverse transcriptase polymerase chain reaction (RT-PCR) technique the authors analysed the expression of 22 Vα and 24 Vβ families in muscle tissue from six patientswith IBM displaying intense inflammatory cell infiltration. The following Vα/Vβ families appeared in at least 50% of the patients: Vα1, 5, 7, 15, 16, 17, 20, 21, 22 and Vβ3, 5.2, 8, 12, 14, 22. In all patients Vα7, 16 and Vβ8 wereexpressed in muscle tissue. Furthermore, in two of the patients peripheral blood lymphocytes (PBL) were investigated in parallel. There was a restricted usage of Vα and Vβ families in muscle in comparison to PBL, indicating a selective homing orlocal proliferation of T lymphocytes in the inflammatory lesions in IBM.

Notes: Our objective was to investigate the patterns of proliferation and differentiation of infiltrating cells in inflammatory myopathies. Immunohistochemical staining was performed on muscle biopsy specimens from 18 patients with inclusion body myositis, polymyositis and dermatomyositis using monoclonal and polyclonal antibodies.An abundance of cells were TNF-α+ (4–8%), ICAM-1+ (7–65%). IFN-γ+ (3–6%), and Ki-67+ (4–8%). It was shown that 70% of the Ki-67+ cells were Ki-67+CD3+ cells. Very few mononuclear cells were IL-2R+. MHC-I expression was found on nearly all muscle fibres in all cases, while MHC-II expression was found on occasional muscle fibres in 1/3 of cases. Analysis of repeated biopsies from four IBM patients after prednisolone treatment showed no change in the proportions of TNF-α, ICAM-1, IFN-γ or Ki-67 positive cells. In inflammatory myopathies there is an intense proliferation and differentiation of inflammatory cells in situ, indicating a local stimulation of the inflammatory process.

Notes: The temporomandibular joint (TMJ) in spontaneously arthritic MRL lpr/lpr (MRL/1) mice has been histologically analysed. After decalcification and standardized preparation of the joint tissue, histological sections were examined for presence of synovial hypertrophy, synovial villi, pannus tissue, erosions, cysts and signs of periarticular inflammation. In 12 of 13 TMJs examined, histopathological changes indicating a state of arthropathy were found. The most prevalent finding was synovial proliferation, which was frequently detected at the insertion of the synovial membrane to the bone. Two or more signs of inflammatory involvement including synovial proliferation, pannus tissue and bone erosion were seen in 5 mice with a predominance among the oldest mice (〉5 months of age). No lymphocytic cell infiltration was found in the analyzed synovial tissues of the TMJ. In contrast, lymphocytes were observed in the vicinity of periarticular blood vessels and tendons. It is concluded that the TMJ is frequently involved in the arthritic disease of autoimmune MRL/1 mice.

Notes: Although it has been documented that exogenous antigens of microbial origin are involved in the induction of the local inflammatory responses in human adult periodontitis (AP), endogeneous antigens may contribute to the chronicity of this common disease. In this study, we used the enzyme-linked immunospot (ELISPOT) test to enumerate antibody-secreting cells to human collagen Types 1-VI by cells isolated from the gingivae and peripheral blood of AP patients. Analyses of dissociated cells from gingivae of 39 AP patients revealed the presence of high numbers of cells that secrete antibodies to Type I collagen, and to a lesser extent, Type III. Although the majority of such cells produced specific antibodies of the IgG class, IgA- and IgM- anti-collagen -secreting cells were also detected. When compared to the total antibody-producing cells, the numbers of cells forming specific antibodies to collagen Type I were surprisingly high. In contrast, anti-collagen antibody-producing cells were rarely detected in the peripheral blood of patients with adult periodontal disease and only low levels of anti-collagen antibodies were present in the serum. The finding of local production of anti-collagen antibodies in AP suggests that autoimmunity may contribute to the pathogenesis of this common disease.