INFLUENCE OF PERIODONTAL BACTERIA AND DISEASE STATUS ON V-BETA EXPRESSION IN T-CELLS

Some bacterial antigens such as S. aureus enterotoxins can selectively stimulate T cells that express specific V beta genes of the T cell an tigen receptor (TCR). The purpose of this study was to investigate whe ther or not periodontal bacteria could similarly alter the expression of V beta families within the TCR complex. Peripheral blood mononuclea r cells (PBMNCs) were isolated from 12 patients with early onset perio dontitis and 11 periodontally-healthy controls. PBMNCs were incubated in media alone, or co-cultured for 48 h with heat-inactivated A. actin omycetemcomitans, P. gingivalis, and P. intermedia. Expression of five VP 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 diffe rences in the number or direction of changes in samples from patients and controls. When compared to unstimulated controls, 18 significant i ncreases 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) upregulated expression of the five VP families studied. These d ata suggest that periodontal bacteria may alter vp expression within t he T cell receptor complex.