Host and Porphyromonas gingivalis proteinases in periodontitis: A biochemical model of infection and tissue destruction

Periodontitis is an excellent model of local tissue destruction due to the uncontrolled action of host and microbial proteinases. Although host enzymes are responsible for direct degradation of connective tissue, proteinases from the periodontopathogenic bacterium Porphyromonas gingivalis are able to activate the kallikrein/kinin cascade, disrupt coagulation, and activate complement-mediated chemotaxis. Since the hallmarks of adult onset of periodontitis include infection by this pathogen, bleeding, increased crevicular flow, and neutrophil accumulation, investigations of this disease at a biochemical level indicate a major role for bacterial proteinases in infections by P. gingivalis.