Molecular Characterization Of The Gingipains Of Porphyromonas Gingivalis
Funder
National Health and Medical Research Council
Funding Amount
$394,000.00
Summary
Chronic periodontitis is a bacteria-associated inflammatory disease of the supporting tissues of the teeth, which results in the destruction of tooth support and ultimately leads to tooth loss. The disease is a major public health problem with a large economic burden and has been associated with an increased risk of cardiovascular disease and pre-term birth and low birth weight. The bacterium Porphyromonas gingivalis has now been identified as a major pathogen in the development of chronic perio ....Chronic periodontitis is a bacteria-associated inflammatory disease of the supporting tissues of the teeth, which results in the destruction of tooth support and ultimately leads to tooth loss. The disease is a major public health problem with a large economic burden and has been associated with an increased risk of cardiovascular disease and pre-term birth and low birth weight. The bacterium Porphyromonas gingivalis has now been identified as a major pathogen in the development of chronic periodontitis. We have identified a major virulence factor of P. gingivalis which is an extracellular complex of proteins involved in binding and destroying host proteins. The aim of this proposal is to characterize the secretion, molecular processing and assembly of the cell surface complex using state-of-the-art proteomic techniques. This study will provide valuable insight into the molecular processes of a bacterial pathogen that leads to virulence. Detailed knowledge on the unique molecular events involved in secretion, processing and assembly of a major virulence factor will provide molecular targets for the development of specific inhibitors that may have utility as an adjunctive therapeutic and-or as part of a preventive regime or maintenance program for the control of chronic periodontitis. Further, the molecular insight that will result from this study will have broader application in the understanding of virulence factor processing of a Gram-negative pathogen that will provide paradigms for other bacterial pathogens.Read moreRead less
Porphyromonas Gingivalis Cysteine Proteinases In Modulation Of Cell-mediated Immune Response In Periodontitis
Funder
National Health and Medical Research Council
Funding Amount
$228,000.00
Summary
Chronic inflammatory diseases of the tissues supporting the teeth comprise some of the most widespread and common diseases to affect mankind. Recent research has indicated the major contributor to the most common form of destructive periodontal disease is the bacterium Porphyromonas gingivalis. This organism produces powerful enzymes which overcome the body's attempts to neutralise them. It is also known that the destructive phase of the disease is characterised by a change in the behaviour of t ....Chronic inflammatory diseases of the tissues supporting the teeth comprise some of the most widespread and common diseases to affect mankind. Recent research has indicated the major contributor to the most common form of destructive periodontal disease is the bacterium Porphyromonas gingivalis. This organism produces powerful enzymes which overcome the body's attempts to neutralise them. It is also known that the destructive phase of the disease is characterised by a change in the behaviour of the immune system cells which accumulate in the diseased tissues. This is manifest as a loss of protective immunity and replacement by ineffective or even tissue damaging responses. Critical in directing the pattern of behaviour of the immune system cells are the potent messenger molecules or cytokines which pass between cells. We have demonstrated that the bacterial proteinases can destroy a critical messenger molecule that instructs the defensive phagocytic cells to attack bacteria. These cells in return normally send a powerful signal back to the controlling T lymphocyte to amplify the protective signals. Associated bacterial molecules stimulate more secretion of messenger molecules which are paradoxically destroyed by the bacterial enzymes. This could cause chaos in the local tissue environment. Further, the bacterial proteinases can also eliminate some important surface molecules of T lymphocyte that are important in the activation process. The effect of this could produce impairment of T lymphocyte at periodontal sites. The planned research will define how the proteinases modulate T lymphocyte immune response. Further, the relation between the capacity of the bacterial enzymes to disrupt the vascular cells and the progression of periodontitis will also be determined.Read moreRead less