IADR Abstract Archives

Intracellular Fate of Porphyromonas gingivalis Protease/Adhesin Components in Epithelial Cells

Objectives: Porphyromonas gingivalis is an important pathogen associated with destructive periodontal disease and its cysteine proteases are recognised as major virulence factors. In a previous IADR meeting we showed that HRgpA, the heterodimeric arginine-specific cysteine protease/adhesin, which consists of a and b chains respectively, rapidly translocated into epithelial cells and entered the nuclei within 30-60 min. This occurred with both proteolytically active and inactive forms of HRgpA.

Methods: To understand the importance of the a and the b chains in the cell entry and nuclear localisation, KB cells were incubated with the recombinant proteins rRgpA a and rRgpAb (Slaney et al 2002 Periodontal Research; 37: 215-222). rRagB which is an outer membrane protein was used a negative control and HRgpA as a positive control. The cells were fixed, permeabilised and stained for immunofluoresence microscopy using specific antibodies to each of the components tested.

Results: After 1 hour of incubation, rRgpA a was able to enter the cells and was scattered diffusely within the cytoplasm but did not show the nuclear localisation typical of HRgpA, whereas rRgpAb localised around the nuclei of the cells. rRagB, however, showed no localisation. These results emphasise the importance of the adhesin component in targeting the nuclei of epithelial cells.

Conclusion: These observations may provide insight into the previously-reported localisation of whole viable P. gingivalis bacteria and lead to an enhanced understanding of the intracellular mechanism(s) of action of P. gingivalis protease.

Supported by grants from the Special Trustees of the Royal London Hospital, St Bartholomew’s Hospital and the MRC, UK.


IADR/PER General Session
2003 IADR/PER General Session (Goteborg, Sweden)
Goteborg, Sweden
2003
217
Microbiology / Immunology and Infection Control
  • Alsam, Asil  ( Clinical and Diagnostic Oral Sciences QMUL, London, N/A, England )
  • Scragg, M.a.  ( Clinical and Diagnostic Oral Sciences QMUL, London, N/A, England )
  • Slaney, Jennifer M.  ( Medical Microbiology QMUL, London, N/A, England )
  • Aduse-opoku, J  ( Medical Microbiology QMUL, London, N/A, England )
  • Williams, D.m.  ( Clinical and Diagnostic Oral Sciences QMUL, London, N/A, England )
  • Curtis, M.a.  ( Medical Microbiology QMUL, London, N/A, England )
    • Oral
    Cellular Microbiology
    06/26/2003