| Project/Area Number |
01870089
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
小児・社会系歯学
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| Research Institution | Osaka University Faculty of Dentistry |
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Principal Investigator |
OOSHIMA Takashi Osaka Univ. Facul. Dent., Associate Prof., 歯学部, 助教授 (80116003)
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| Co-Investigator(Kenkyū-buntansha) |
OGAWA Tomohiko Osaka Univ. Facul. Dent., Assistant., 歯学部, 助手 (80160761)
TAKADA Haruhiko Osaka Univ. Facul. Dent., Assistant Prof., 歯学部, 助教授 (30135743)
IZUMITANI Akira Osaka Univ. Facul. Dent., Assistant Prof., 歯学部附属病院, 講師 (70168277)
MORISAKI Ichijiro Osaka Univ. Facul. Dent., Associate Prof., 歯学部附属病院, 助教授 (30116115)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 1990: ¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1989: ¥6,300,000 (Direct Cost: ¥6,300,000)
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| Keywords | Streptococcus mutans / Glucosyltransferase / Oral passive immunization / Dental caries / Egg yolk antibody / Stroptococcus mutans / 受動免疫 |
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| Research Abstract |
The effect of polyclonal egg yolk antibodies (yIgG) raised against whole cells, cell-free (CF) glucosyltransferase (GTase), cell-associated (CA) GTase, surface protein antigen (PAc) of serotype c S. Mutans was examined in terms of in vitro inhibition of virulence-related factors of S. mutans and protection of S. mutans-infected rats against the development of dental caries. Hens (18 weeks old) were immunized with formalintreated whole cells, purified CF-GTase, CA-GTase or PAc together with Freund complete adjuvant. yIgG was purified by ammonium sulfate precipitation followed by DEAE-Sephacel column chromatography or fractional precipitation with ethanol. Purified yIgG was found to be a 220-kDa protein, which was dissociated into H and L chains upon addition of 2-mercaptoethanol. yIgG to whole cells gave a heavy aggregation of the organisms of S. mutans, while yIgG to CF-and CA-GTase specifically inhibited the enzymatic activity of these GTases, respectively. yIgG to CA-GTase and whole cells was found to suppress clearly the cell adherence of S. mutans to a glass surface. Specific-pathogen-free Sprague-Dawley rats that had been infected heavily and repeatedly with S. Mutans and fed diet #2000 induced severe dental caries, while rats fed diet #2000 containing>0.1% yIgG to CA-GTase resulted in a statistically significant reduction in dental plaque accumulation and caries development. Administration of yIgG to CF-GTase failed to protect against caries. These results clearly suggest that yIgG to S. mutants CA-GTase specifically inhibited a virulence factor of this organism, i. e. Insoluble glucan synthesizing CA-GTase, resulting in a significant drop in the development of dental caries.
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