Polymicrobial Pathogenesis In A Murine Periodontitis Model.
Funder
National Health and Medical Research Council
Funding Amount
$235,500.00
Summary
Severe periodontal disease is a chronic inflammatory disease of the tooth's supporting tissues and is associated with specific pathogenic bacteria. The disease has a large economic burden and is a major public health problem. Three bacterial species have recently been shown to be closely associated with advanced periodontal disease in humans. One of these three bacterial species has been shown to produce periodontal disease in a mouse model of disease and the major proteins on the cell surface o ....Severe periodontal disease is a chronic inflammatory disease of the tooth's supporting tissues and is associated with specific pathogenic bacteria. The disease has a large economic burden and is a major public health problem. Three bacterial species have recently been shown to be closely associated with advanced periodontal disease in humans. One of these three bacterial species has been shown to produce periodontal disease in a mouse model of disease and the major proteins on the cell surface of this bacterium have been characterized. Further, in this mouse model it has been demonstrated that killed cells of the bacterium or the major surface proteins when used as a vaccine prevent development of disease. The purpose of the current proposal is to extend this work to include all three bacterial species that have been associated with disease in humans. The major surface proteins of all these bacterial species when grown together as high density polymicrobial complexes will be determined. Recent results have shown that in high-density, polymicrobial cultures bacteria communicate using signalling systems which can alter the expression of cell surface proteins associated with disease. The ability of the three bacterial species, when grown in polymicrobial culture, to cause periodontal disease in the mouse model will be determined. This will allow the determination of whether a single species and-or multispecies vaccine is capable of protecting against disease in this model. The significance of the work is that it will increase our understanding of the bacteria associated with periodontal disease and it may lead to the development of an effective vaccine to help prevent disease in humans.Read moreRead less
The RgpA-Kgp Proteinase-adhesin Complex And Virulence Of Porphyromonas Gingivalis
Funder
National Health and Medical Research Council
Funding Amount
$527,310.00
Summary
Periodontitis is a bacterial-associated inflammatory disease of the supporting tissues of the teeth which can result in tooth loss. The disease is a major public health problem with a large economic burden. A bacterium Porphyromonas gingivalis has now been identified as a major causative agent of chronic periodontitis. We have identified a major virulence factor of P. gingivalis. This virulence factor is a complex of proteins, encoded by two genes, and is involved in binding and destruction of h ....Periodontitis is a bacterial-associated inflammatory disease of the supporting tissues of the teeth which can result in tooth loss. The disease is a major public health problem with a large economic burden. A bacterium Porphyromonas gingivalis has now been identified as a major causative agent of chronic periodontitis. We have identified a major virulence factor of P. gingivalis. This virulence factor is a complex of proteins, encoded by two genes, and is involved in binding and destruction of host tissue. When used as a vaccine in animal models the protein complex protects against P. gingivalis infection. Animal protective sera recognises a segment of the protein complex involved in binding to host substrates. The aim of this project is to continue this work on the characterisation of this complex and its role in virulence in an approach to ultimately develop a defined vaccine against P. gingivalis based on this protein complex, in particular the sequences involved in binding. The expected outcome of this research is the further biochemical characterisation of the RgpA-Kgp protein complex and its role in virulence as well as development of a defined vaccine prepared using recombinant DNA and chemical synthesis techniques that protects against P. gingivalis infection in animal models of disease.Read moreRead less
Development Of An Immunotherapy Against Kgp Of Porphyromonas Gingivalis
Funder
National Health and Medical Research Council
Funding Amount
$495,710.00
Summary
Chronic periodontitis is an inflammatory disease of the supporting tissues of the teeth associated with specific bacteria, which results in the destruction of tooth support and ultimately leads to tooth loss. This project aims to develop an immunotherapy against the major virulence factor produced by bacteria associated with the disease. The immunotherapy will be evaluated in animal models of disease.
Relationship Between Periodontal Disease And Rheumatoid Arthritis
Funder
National Health and Medical Research Council
Funding Amount
$520,657.00
Summary
Periodontal (gum) disease and rheumatoid arthritis are two of the most common chronic inflammatory diseases affecting humans. These two diseases have remarkably similar patterns of tissue destruction. It is possible that individuals with chronic periodontitis may prime or predispose individuals prone to developing rheumatoid arthritis. Treatment of periodontal disease may help reduce the severity of rheumatoid arthritis.
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
Iron/hemin Transport Systems Of Porphyromonas Gingivalis
Funder
National Health and Medical Research Council
Funding Amount
$392,036.00
Summary
Periodontitis is a bacterial-associated disease of the supporting structures of the teeth and can result in tooth loss. The disease is classified as a major public health problem with an enormous economic burden. A bacterium, Porphyromonas gingivalis, has now been implicated as a major causative agent of periodontitis in adults. To survive and grow within humans pathogenic bacteria must be able to acquire essential elements, including iron. The human host has developed a variety of mechanisms to ....Periodontitis is a bacterial-associated disease of the supporting structures of the teeth and can result in tooth loss. The disease is classified as a major public health problem with an enormous economic burden. A bacterium, Porphyromonas gingivalis, has now been implicated as a major causative agent of periodontitis in adults. To survive and grow within humans pathogenic bacteria must be able to acquire essential elements, including iron. The human host has developed a variety of mechanisms to restrict the amount of iron available as a means of limiting the growth of bacterial pathogens. In response to this iron limitation Porphyromonas gingivalis has developed novel ways of obtaining this essential element. We have identified a novel iron transport system that P. gingivalis uses to obtain iron from the human host. A component of this transport system, FetB is a surface protein antigen. The aims of this project are to: i. Determine the mechanism by which this novel iron transport system functions by genetic manipulation of the organism using molecular biology techniques. ii. Determine how important this transport system is for the pathogenicity of the bacterium. iii. Prepare the FetB protein using recombinant DNA technology. iv. Test the recombinant FetB protein and another iron transport protein (Tlr) in animal models to determine their efficacy as a vaccine for periodontitis. The expected outcomes of this research are:- i. the understanding of how P. gingivalis transports iron. ii. an understanding of the importance of iron transport systems to the pathogenicity of the bacterium. iii. a P. gingivalis vaccine with efficacy in animals based on an iron transport protein(s).Read moreRead less
Cell Surface Protein Antigens Of Porphyromonas Gingivalis
Funder
National Health and Medical Research Council
Funding Amount
$339,634.00
Summary
Periodontitis is a bacterial-associated disease of the supporting structures of the teeth and can result in tooth loss. The disease is classified as a major public health problem with an enormous economic burden. A bacterium Porphyromonas gingivalis has now been identified as a major causative agent of periodontitis in adults. We have developed methods to rapidly identify all the surface protein antigens of P. gingivalis using mass spectrometry and then using recombinant DNA technology to expres ....Periodontitis is a bacterial-associated disease of the supporting structures of the teeth and can result in tooth loss. The disease is classified as a major public health problem with an enormous economic burden. A bacterium Porphyromonas gingivalis has now been identified as a major causative agent of periodontitis in adults. We have developed methods to rapidly identify all the surface protein antigens of P. gingivalis using mass spectrometry and then using recombinant DNA technology to express these recombinant antigens for testing in animal models of disease. The aim of this project is: (i) to rapidly identify cell surface protein antigens of P. gingivalis using novel techniques. (ii) prepare these antigens using recombinant DNA technology. (iii) use patient and healthy subject sera as well as animal antisera to screen the recombinant antigens for suitable candidates for an immunodiagnostic product and-or vaccine. (iv) test the recombinant antigens in animal models of disease in an approach to identify a candidate antigen for a vaccine. The expected outcomes of this research are that (i) we will develop techniques that can be used to characterise the cell surface antigens of any pathogenic bacterium. (ii) we will determine the organisation and the structure of the cell surface proteins of P. gingivalis. (iii) we will identify an abundant, unique and immunogenic protein of the P. gingivalis surface that will be a suitable candidate antigen for the development of a sensitive and specific immunodiagnostic. (iv) we will identify a cell surface antigen that when used as a vaccine in animals prevents disease caused by P. gingivalis.Read moreRead less