Melbourne Dental School

Oral Biology

The research in the Oral Biology Research Group is directed towards the understanding of oral diseases at the microbial, molecular and immunological level, with a view to the development of novel, effective and specific prevention and treatment strategies. To this end, we have developed within our laboratories a unique interdisciplinary approach utilising state of the art technology. The Oral Biology Research Group has an established international reputation in several research areas with substantial funding from the National Institutes of Health (USA), National Health and Medical Research Council and industry. The research is conducted by a multi-disciplinary team of highly qualified scientists and post-graduate students who are involved in local and international collaborations with strong industry links. The Oral Biology Research Group is a founding member of the CRC for Oral Health Science and a member of the Bio21 Molecular Science and Biotechnology Institute (www.bio21.com.au). Both staff and students have won several national and international awards.

Academic Staff:

Professor

Principal Research Fellow

Senior Research Fellows

Research Fellows

Research Assistants

Laboratory Manager

Technical Officer

Research Activities:

Current areas of major research within the Group include:-

  1. The proteomic analysis of oral bacterial pathogens. We are using 2D-gel electrophoresis, multidimensional LC and mass spectrometry analyses to identify outer membrane associated proteins and antigens of Porphyromonas gingivalis, Treponema denticola and Tanerella forsythia, the bacteria associated with periodontitis. We are also investigating the effect of environmental conditions including growth as a biofilm and iron availability on bacterial protein expression. This work will enable us not only to identify novel antigenic proteins that may be used for the development of vaccines against these bacteria but will also help us to understand the role of a variety of bacterial proteins in their virulence and physiology.
  2. Development of periodontal disease vaccines. We have already identified a number of potential vaccine candidates from P. gingivalis. These identified peptides and proteins have been shown to induce protection in animal models of disease. We are currently identifying T-cell and B-cell epitopes for peptide-based vaccine approach, as well as developing recombinant protein and DNA vaccine strategies.
  3. Characterisation of novel P. gingivalis cell surface proteinase/adhesins. We have a strategic research program to characterize the novel extracellular proteinase/adhesin complexes of P. gingivalis and determine their role in pathogenesis using animal models. Using a combination of genetic and protein approaches including insertional gene inactivation, site-directed mutagenesis, protein cross-linking and mass spectrometric analyses we are determining the structure, function and secretion of these unique cell surface proteins. Using a series of isogenic mutants we have already determined that these proteins are the major virulence factors of the bacterium.
  4. Transcriptome analysis of oral bacterial pathogens. We are analyzing the effects of growth as a bacterial biofilm and the growth in a polymicrobial biofilm on gene expression by Porphyromonas gingivalis and Treponema denticola using DNA microarray analysis. These bacteria cause disease by growing as a consortium withTanerella forsythiain a polymicrobial biofilm. There is a degree of cooperativity between these bacteria that we are investigating by transcriptome analysis. These projects include the development of novel culture techniques for these Gram-negative obligate anaerobes.
  5. Characterisation of biomineralising peptides and proteins. Casein phosphopeptides (CPP) stabilise amorphous calcium phosphate as (CPP-ACP) and have been demonstrated to be anticariogenic in our laboratory. The CPP-ACP substantially increase the levels of calcium and phosphate in dental plaque thereby depressing enamel demineralisation and facilitating remineralisation. The motif responsible for stabilisation of amorphous calcium phosphate has been identified using synthetic phosphopeptides as -Ser(P)-Ser(P)-Ser(P)-Glu-Glu-. This technology has been patented and developed commercially by industry partners. It is now commercially available world-wide in sugar-free gum (Recaldent and Xtracare) and in professional oral care products (Tooth Mousse and MI paste). The three dimensional structure of the CPP are currently under investigation using 2-D NMR and computerised molecular modelling. Further proteins involved in biomineralisation and the development of biomimetics are also under investigation.
  6. The development of novel antimicrobial peptides from biological sources. We have recently isolated and characterised a novel antimicrobial peptide from casein. This peptide is active against a range of oral bacteria and has little similarity with known antimicrobial peptides. We are currently investigating the mechanism of action of this peptide and have synthesized and tested the 21 residue phosphorylated peptide corresponding to the active region. The three dimensional structure of the peptide is currently under investigation using 2-D NMR. We are also bioprospecting for further novel bioactive peptides using a range of novel approaches.

Teaching Activities:

Undergraduate

The Oral Biology Research Group has involvement in the teaching of Oral Biology, Biochemistry, Microbiology and Immunolgy to undergraduate dental students.

Postgraduate

The Research Group offers a wide range of graduate and post-graduate programs including Bachelor of Science (Hons), Master of Science, Graduate Diplomas and PhDs. There are currently 12 PhD and BSc(Hons) students in the Section of Oral Biology.
Dr Paul Veith analysing the proteome of the oral bacterial pathogen Treponema denticola on the Bruker Ultraflex TOF/TOF mass spectrometer. Roselind Lam, PhD student, studying gene expression using Real Time PCR analysis.

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