2002 Fiscal Year Final Research Report Summary
Investigation and characterization for the periodontopathic bacterial genes specifically expressing in vivo
| Project/Area Number |
13671901
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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 | Okayama University |
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Principal Investigator |
KOKEGUCHI Susumu Okayama University, Graduate School of Medicine and Dentistry, Associate Professor, 大学院・医歯学総合研究科, 助教授 (10144776)
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| Co-Investigator(Kenkyū-buntansha) |
SHINGAKI Ryuji Okayama University, Graduate School of Medicine and Dentistry, Instructor, 大学院・医歯学総合研究科, 助手 (40294417)
INOUE Tetsuyoshi Okayama University, Graduate School of Medicine and Dentistry, Instructor, 大学院・医歯学総合研究科, 助手 (20223258)
FUKUI Kazuhiro Okayama University, Graduate School of Medicine and Dentistry, Professor, 大学院・医歯学総合研究科, 教授 (70034171)
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| Project Period (FY) |
2001 – 2002
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| Keywords | periodontopathic bacteria / Porphyromonas gingivalis / Actinobacillus actinomycetemcomitans / in vivo-expressing / bacterial genes |
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| Research Abstract |
Pathogenic bacteria could express specific genes and its proteins under the specific growth condition or especially in vivo, which might be related to bacterial growth and pathogenicity. In this study, we aimed to investigate and characterize such specific genes and proteins of periodontopathic bacteria, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans expressing in vivo.
The major results of this study are as follows:
1)P. gingivalis expresses specific 53-kDa outer membrane protein(Ag53) which evokes strong humoral immune responses in evokes strong humoral immune responses in many patients with periodontal disease. Three sequences, RAAIRAS, YYLQ and MSPARR, were identified as major B-cell epitopes in Ag53, which might influence individual differences in antibody titer against Ag53.
2)A. actinomycetemcomitans express fimbriae in vivo that plays an important role in the ability of this bacterium to colonize teeth and other surfaces. The flp-1 gene encodes the major fimbriae protein component of A. actinomycetemcomitans. We compared flp-1 DNA sequences from 43 A. actinomycetemcomitans clinical isolates. DNA and predicted protein sequences were highly divergent in the C-terminus of the flp-1 protein that has been shown to be important for the bundling and adhesive properties of the fimbriae, suggesting that these diverse strains carry pathogenic potential.
3) Two genes encoding ferritin-like protein were identified in the upstream region of actX from A. actinomycetemcomitans which controls its growth and virulence. Two ferritin genes constituted a bicistronic operon and the accumulation of its mRNA was upregulated under aerobic conditions, suggested that the operon may have important roles in the adaptation of the bacteria to oxidative environmental changes.
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