Mechanisms of the Periodontal Tissue Destruction by Periodontopathogenic Bacteria

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Some kinds of proteases produced by periodontopathogenic bacteria are considered to be the putative viruent factor of periodontal disease. We have already determined that Porphyromonas gingivalis, a probalbe periodontopathogenic bacterium in adult periodontitis, produces several types of proteases. This study describes the mechanisms of the periodontal tissue destruction by these virulent factors.Three kinds of proteases (Pase-B,Pase-C and Pase-S) which were active on BApNA were isolated and purified from the culture supernatant and vesicles. Polyclonal and monoclonal antibodies were prepared against Pase-S and Pase-C,respectively (pAb-PS,mAb-PC) and the immunological characteristics of these proteases were determined. Pase-S and Pase-B reacted with pAB-PS,but did not with mAB-PC,while Pase-C reacted with mAB-PC but did not with pAB-PS.mAB-PC only reacted with strains of P.gingivalis but did not with other putative periodontopathogenic bacteria which produced BApNA activity such as Bac … More teroides forsUthus and Treponema denticola. Different biological activities were also found in these proteases, that is, type I collagen was sensitive only for Pase-C,but type IV collagen was destroyed by all of these proteases. On the basis of substrate specificity, Pase-C resembles trypsin but Pase-B and Pase-S rather resemble clostripain.As the aggregating activity of the pathogenic bacterium is generally correlated with the bacterial adhesion to host tissues. In order to estimate the relationship between biological activities of possible virulent factors produced by P.gingivalis, statistical analyzes were performed by multiple regression analysis using the cell aggregating activity as the dependent variable and three arginine metabolizing enzyme activities, BApNA hydrolyzing enzyme, arginine carboxypeptidase and arginine deiminase, as explanatory variables. The results of these statistic analyzes suggested that BApNA hydrolyzing activity had the strongest positive relationship to the cell aggregating activity, while arginine deiminase activity showed a negative relationship. These results strongly suggest that Pase-C plays important roles in the adhesion to the periodontal tissues and their destruction. Less