Periodontitis is a chronic inflammatory disease of the soft and hard supporting tissues of the teeth and is a major cause of tooth loss in adults. The local host response to periodontopathic bacteria results in the release of inflammatory mediators and cytokines. Since cytokines are indicative of effector functions, we compared the pattern of cytokine production in periodontal patients and healthy controls. Specifically, we investigated the simultaneous presence of cytokines produced by T helper (Th)l, Th 2, and inflammatory cells which could be involved in periodontitis. We also compared the expression of these cytokine mRNAs in healthy and diseased tissues. No significant differences were detected at the protein or mRNA levels of the cytokines in the systemic circulation of patients and controls. The surface markers CD 16 and CD56 were expressed on significantly fewer peripheral mononuclear cells of patients when compared to controls. γδ+ T cells were found in half of the diseased tissues, but in none of the healthy tissues of either patients or controls. Finally, significant differences were observed between healthy and inflamed gingival tissues in the cytokine mRNA profile. Expression of IL‐6 and IFN‐α mRNA was significantly higher in diseased tissues compared to healthy tissues in patients. J Periodontol 1996;67:515–522.

The adaptive immune system consists of humoral and cell-mediated immunity. T-lymphocytes are the key components of cell-mediated immunity. CD4+ helper T-lymphocytes facilitate B-cells to differentiate and produce specific antibodies, whereas CD8+ cytotoxic T-lymphocytes kill virally infected cells. Periodontal diseases have been associated with a variety of imbalances in the regulation of immune responses. Changes in the ratios of peripheral blood CD4+ and CD8+ T-lymphocytes, depressed proliferative responses of peripheral blood lymphocytes, and increased frequency of CD45RO+ memory T-lymphocytes in diseased tissues have been reported in individuals with various forms of periodontal disease. While some studies have shown an increased frequency of 'y+ T-cells in periodontal lesions, the role of y8+ T-cells in periodontal disease remains controversial. The ability of putative periodontopathic bacteria selectively to stimulate certain VP3-expressing T-cells is intriguing and could determine whether a CD4+ Th 1 or a CD4+ Th2 cell response is elicited. The prominence of a particular subset of helper T-cells within the periodontal lesion could be a reflection of the stage and activity of the disease, or the types of bacteria present. Regardless, longitudinal studies of the involvement of T-cell subsets and cytokines in periodontal disease are clearly needed.

Some bacterial antigens such as S. aureus enterotoxins can selectively stimulate T cells that express specific V beta genes of the T cell antigen receptor (TCR). The purpose of this study was to investigate whether or not periodontal bacteria could similarly alter the expression of V beta families within the TCR complex. Peripheral blood mononuclear cells (PBMNCs) were isolated from 12 patients with early onset periodontitis and 11 periodontally-healthy controls. PBMNCs were incubated in media alone, or co-cultured for 48 h with heat-inactivated A. actinomycetemcomitans, P. gingivalis and P. intermedia. Expression of five V beta families (V alpha beta 2, V beta 5, V beta 6, V beta 8, and V beta 12) was determined by use of monoclonal antibodies. Mean unstimulated expression of V alpha beta 2 and V beta 8 was significantly higher (p < 0.05) in patients than healthy controls. Co-culture with the three bacteria resulted in significant changes (increases or decreases) in V beta expression in 27% of the trials. There were no significant differences in the number or direction of changes in samples from patients and controls. When compared to unstimulated controls, 18 significant increases but no decreases in the percentage of cell expressing V alpha beta 2, V beta 5 or V beta 6 were noted following co-culture with P. intermedia. Overall, co-culture with P. intermedia significantly (p< 0.05) up-regulated expression of the five V beta families studied. These data suggest that periodontal bacteria may alter V beta expression within the T cell receptor complex.

Autophagy is an essential intracellular self-degradation system to maintain the homeostatic balance between the synthesis, degradation and recycling of cellular proteins and organelles. Recently, it is reported that autophagy is associated with systemic lupus erythematosus, rheumatoid arthritis and idiopathic pulmonary fibrosis. The association with autophagy and scleroderma (SSc) is also suspected, however, the role of autophagy in the pathogenesis of tissue fibrosis is still unclarified, and the association of which phase of scleroderma is largely unknown. Therefore, we investigated the role of autophagy in the pathogenesis of SSc by using skin and lung samples of bleomycin (BLM)-induced SSc murine model and human SSc skin. BLM or phosphate-buffered saline (PBS) was injected into shaved back of C3H/HeJ mice for 2 or 4 weeks. Also, we used skin samples of edematous phase SSc and those of sclerotic phase SSc. We carried out haematoxylin and eosin (HE) stain for evaluation of skin sclerosis and immunofluorescent stain by anti microtubule-associated protein 1 light chain 3 (LC3) antibody, which is the most common autophagy marker. We evaluated the number of LC3positive dots in fibroblasts in the mice samples (skin and lung) and the human skin samples (both edematous and sclerotic phase). There was no clear difference between the number of LC3-positive dots of skin samples from PBS mice and those from BLM mice qualitatively. We are currently investigating the number of LC3-positive dots of mice lung tissues and human skin samples in more numbers.