| Project/Area Number |
13557181
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
矯正・小児・社会系歯学
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| Research Institution | OSAKA UNIVERSITY |
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Principal Investigator |
AMANO Atsuo DOS, PhD, Graduate School of Dentistry, Professor, 大学院・歯学研究科, 教授 (50193024)
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| Co-Investigator(Kenkyū-buntansha) |
KUBONIWA Masae DDS, PhD, Graduate School of Dentistry, Instructor, 大学院・歯学研究科, 助手 (00303983)
NAKAGAWA Ichiro DDS, PhD, Graduate School of Dentistry, Assistant Professor, 大学院・歯学研究科, 講師 (70294113)
OKAHASHI Nobuo PhD, Graduate School of Dentistry, Associate Professor, 大学院・歯学研究科, 助教授 (40150180)
秋山 茂久 大阪大学, 歯学部・附属病院, 助手 (00283797)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 2002: ¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 2001: ¥9,400,000 (Direct Cost: ¥9,400,000)
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| Keywords | Porphyromonas gingivalis / Genotype / Genotyping / DNA vaccine / Polymerase chain reaction / fimbriae / fimA / fimA / 遺伝子多型 / 線毛遺伝子fimA / 遺伝子診断 / 遺伝子診断法 / ヒト上皮細胞 |
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| Research Abstract |
Adult periodontitis is a highly destructive chronic inflammatory disease resulting from the complex actions of a small subset of periodontal bacteria Among them, Porphyromonas girigivalis has been characterized as a bona fide periodontal pathogen.
This microorganism has been frequently detected in patients with periodontitis, while it reportedly occurs at a tower frequency in periodontally healthy individuals without marked gingival inflammation. There may be diversities in virulence among the organisms harbored by individuals who are periodontally healthy and those with periodontitis. However, it is still unknown whether periodontitis can develop only in the presence of virulent strain(s) of P. gingivalis, or if other host factors, such as genetic background and environmental stress, may have a determining influence in the initiation of the disease in individuals infected by the organism.
The fimA gene of Porphyromonas gingivalis, encoding fimbrillin (a subunit protein of fimbriae) was
… More
classified into six genotypes (types I-V & Ib) among the strains, and the genotypes were previously shown to be related with adult periodontitis in the natural population. Here, virulence heterogeneity among the different fimA strains was examined using a *ouse abscess model and cultured epithelial cells. Bacterial suspensions of thirteen P. gingivalis strains representing sixfimA types were subcutaneously injected to female BALB/c mice, and serum sialic acid concentration was assayed as a quantitative of inflammatory parameter. Infection of P. gingivalis strains to epithelial cells was also examined. Type II fimA oraganisms most significantly increased serum sialic acid concentration, and clearly showed other infectious symptoms in a mouse model,allowed by types Tb, IV and V strains. Whereas, types I and III strains caused weak host responses.
The type II strain invaded epithelial cells significantly greater than the other strains. Accompanied with the invasion of epithelial cells, degradations of paxillin and FAK proteins and loss of their phosphorylation were markedly observed. The invasion and degradation of the proteins by type I and III strains were less than those of the type II strain. The fimA mutants of type II strains clearly lost their infectious abilities both in a mouse model and culture epithelial cells. These findings suggest that fimA genotypic variation is a determinant of virulence of P. gingivalis.
Periodontitis Less
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