title: The role of the RgpA-Kgp proteinase-adhesin complexes in the adherence of Porphyromonas gingivalis to fibroblasts.
abstract: Porphyromonas gingivalis strains W50 and ATCC 33277 were shown to bind to cultured human fibroblast (MRC-5) cells using flow cytometry. As the concentration of P. gingivalis strain W50 cells was increased relative to the concentration of MRC-5 cells, the number of W50 cells bound per MRC-5 cell increased, as did the percentage of MRC-5 cells with bacteria bound. However, this relationship was only seen for P. gingivalis strain ATCC 33277 at low cell concentrations: at high bacterial cell concentrations strain ATCC 33277 auto-aggregated and binding to the MRC-5 cells decreased. Strain W50 was therefore chosen to study the role of the surface proteinase-adhesin complexes (RgpA-Kgp complexes) in binding to MRC-5 cells. P. gingivalis W50 cells treated with an inhibitor of the RgpA-Kgp complexes exhibited reduced binding to MRC-5 cells. The purified active and proteinase-inactive RgpA-Kgp complexes competitively inhibited binding of W50 to MRC-5 cells, and isogenic mutants of W50 lacking RgpA/B and Kgp displayed reduced binding. P. gingivalis W50 mutant cells lacking Kgp exhibited the lowest binding to MRC-5 cells, suggesting an important role for this proteinase and its associated adhesins in binding to fibroblasts.
authors.affiliation: Cooperative Research Centre for Oral Health Science, School of Dental Science, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 720 Swanston Street, Victoria 3010, Australia.
authors.forename: Rishi D
authors.initials: RD
authors.lastname: Pathirana
authors.affiliation: Cooperative Research Centre for Oral Health Science, School of Dental Science, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 720 Swanston Street, Victoria 3010, Australia.
authors.forename: Neil M
authors.initials: NM
authors.lastname: O'Brien-Simpson
authors.affiliation: Cooperative Research Centre for Chronic Inflammatory Diseases, Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Kumar
authors.initials: K
authors.lastname: Visvanathan
authors.affiliation: Cooperative Research Centre for Chronic Inflammatory Diseases, Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: John A
authors.initials: JA
authors.lastname: Hamilton
authors.affiliation: Cooperative Research Centre for Oral Health Science, School of Dental Science, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 720 Swanston Street, Victoria 3010, Australia.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Reynolds
mesh_terms: D018829:Adhesins, Bacterial / Q000187:drug effects / Q000378:metabolism*; D001422:Bacterial Adhesion; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000187:drug effects / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D005347:Fibroblasts / Q000382:microbiology; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D000080867:Gingipain Cysteine Endopeptidases; D006801:Humans; D008856:Microscopy, Fluorescence; D016966:Porphyromonas gingivalis / Q000378:metabolism*; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology
chemical_list: D018829:Adhesins, Bacterial; D000080867:Gingipain Cysteine Endopeptidases; D014107:Tosyllysine Chloromethyl Ketone; D003546:Cysteine Endopeptidases; D016650:Fluorescein-5-isothiocyanate