2007 Fiscal Year Final Research Report Summary
Study for gignipain-related adhesins of Periodontal pathogen, Porphyromonas gingivalis for its platelet aggregation activity
| Project/Area Number |
18592005
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Morphological basic dentistry
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| Research Institution | Nagasaki University |
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Principal Investigator |
NAITO Mariko Nagasaki University, Graduate School of Biomedical Sciences, Assistant Professor (20244072)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Eiko Nagasaki University, Graduate School of Biomedical Sciences, Assistant Professor (10176612)
YOSHIMURA Astutoshi Nagasaki University, Hospital of Medicine and Dentistry, Senior Assistant Professor (70253680)
OHARA Naoya National Institute of Infectious Diseases, Immunology, Chief (70223930)
NAKAYAMA Koji Nagasaki University, Graduate School of Biomedical Sciences, Professor (80150473)
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| Project Period (FY) |
2006 – 2007
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| Keywords | infectrion / bacteriology / P. gingivalis / platelet aggregation / Adhesin / Hgp44 |
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| Research Abstract |
The periodontal pathogen Porphyromonas gingivalis has the ability to aggregate human platelets. P. gingivalis is highly proteolytic, has major protainases, gingipains. The gingipain genes are consisting of N-terminal proteolytic domain and C-terminal adhesin domains. Gingipain derived adhesin, Hgp44 is the key molecule for P gingivalis-induced platelet aggregation in human platelet-rich plasma. The study of truncated recombinant Hgp44 protein shows that the active site is the N-terminal part (1-101 aa). This site is also important for Hgp44-induced erythrocyte aggregation. Hgp44 binds to glycophorin on human erythrocyte, also to human oral epithelial cells. The adhesin domains are also essential for gingipains to suppress of IL-8 induction from human oral epithelial cells. The receptor activator of nuclear factor-LIB (RANKL)-induced osteoclastogenesis from bone marrow is inhibited by one of adhesin domain, HbR. Furthermore the gingipains affect bacteria-host interactions and may directly promote apoptosis. We defined the complete genome sequence of strain ATCC 33277 that is the type strain of P gingivalis. The newly 4 genes find on genome of ATCC 33277 that encoded the adhesin domains of gignipains. Those genes lost the proteolytic domains. Some genes are also defined that transports gingipain to bacterial surface and controls expression of gignipains. Those transporters suggested the unique secretion system for gignipain. Those results indicates that gingipain derived adhesins has various biological activity in host cells. Such complex activity might to help the microorganism exist long in the niche. Clearly, a detailed knowledge of how gignipain, also its adhesin domain protein, regulates host cells will shed important light on the mechanism of tissue damage in gingivitis and may provide a pharmacological regimen to control the infection.
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