Invasion of Epithelial Cells and Proteolysis of Cellular Focal Adhesion Components by Distinct Types of Porphyromonas gingivalis Fimbriae
Porphyromonas gingivalis fimbriae are classified into six types (types I to V and Ib) based on the fimA genes encoding FimA (a subunit of fimbriae), and they play a critical role in bacterial interactions with host tissues. In this study, we compared the efficiencies of P. gingivalis strains with di...
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Published in | Infection and Immunity Vol. 74; no. 7; pp. 3773 - 3782 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Society for Microbiology
01.07.2006
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Subjects | |
Online Access | Get full text |
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Summary: | Porphyromonas gingivalis fimbriae are classified into six types (types I to V and Ib) based on the fimA genes encoding FimA (a subunit of fimbriae), and they play a critical role in bacterial interactions with host tissues. In this study, we compared the efficiencies of P. gingivalis strains with distinct types of fimbriae for invasion of epithelial cells and for degradation of cellular focal adhesion components, paxillin, and focal adhesion kinase (FAK). Six representative strains with the different types of fimbriae were tested, and P. gingivalis with type II fimbriae (type II P. gingivalis) adhered to and invaded epithelial cells at significantly greater levels than the other strains. There were negligible differences in gingipain activities among the six strains; however, type II P. gingivalis apparently degraded intracellular paxillin in association with a loss of phosphorylation 30 min after infection. Degradation was blocked with cytochalasin D or in mutants with fimA disrupted. Paxillin was degraded by the mutant with Lys-gingipain disrupted, and this degradation was prevented by inhibition of Arg-gingipain activity by Nα-p-tosyl-L-lysine chloromethyl ketone. FAK was also degraded by type II P. gingivalis. Cellular focal adhesions with green fluorescent protein-paxillin macroaggregates were clearly destroyed, and this was associated with cellular morphological changes and microtubule disassembly. In an in vitro wound closure assay, type II P. gingivalis significantly inhibited cellular migration and proliferation compared to the cellular migration and proliferation observed with the other types. These results suggest that type II P. gingivalis efficiently invades epithelial cells and degrades focal adhesion components with Arg-gingipain, which results in cellular impairment during wound healing and periodontal tissue regeneration. |
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Bibliography: | http://iai.asm.org/ ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Editor: V. J. DiRita Corresponding author. Mailing address: Department of Oral Frontier Biology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-Osaka 565-0871, Japan. Phone: 81-6-6879-2976. Fax: 81-6-6876-8455. E-mail: amanoa@dent.osaka-u.ac.jp. Present address: Division of Bacteriology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan. |
ISSN: | 0019-9567 1098-5522 |
DOI: | 10.1128/IAI.01902-05 |