| Project/Area Number |
18390489
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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 | 一般 |
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| Research Field |
Morphological basic dentistry
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| Research Institution | Osaka University |
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Principal Investigator |
KAWABATA Shigetada Osaka University, Department of Oral and Molecular Microbiology, Professor (50273694)
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| Co-Investigator(Kenkyū-buntansha) |
TERAO Yutaka Osaka University, Department of Oral and Molecular Microbiology, Associate Professor (50397717)
NEKATA Masanobu Osaka University, Depoartment of Oral and Molecular Miaobiology, Assistant Professor (90444497)
SUMITOMO Tomoko Osaka University, Department of Oral and Molecular Microbiology, Assistant Professor (50423421)
OKAMOTO Shigefumi National Institute of Biomedical Innovation, Division of Biomedical Research, Researcher (50311759)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥16,940,000 (Direct Cost: ¥15,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2007: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2006: ¥12,000,000 (Direct Cost: ¥12,000,000)
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| Keywords | Streptococcus pyogenes / fibronectin-binding protein / FbaA / FbaB / group A streptococci / vaccine / cell-associated protein / potective antigen / フィブロネクチン結合タンパク / 菌体表層タンパク |
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| Research Abstract |
Background. Surface-associated fibronectin (Fn) -binding proteins of group A Streptococcus pyogenes play important roles in the bacterial invasion of epithelial cells. The aim of this study was to examine the functional domain and protective antigenicity of the Fn-binding proteins FbaA and FbaB.
Methods. To investigate the functional domain of FbaA or FbaB and their localization on S. pyogenes, a series of recombinant GST-truncated FbaA or FbaB proteins were employed for immunofluorescent microscopy, ligand blot, and Biacore analyses. Mice were immunized with the truncated proteins to determine the immunogenic domains that contribute to protection against S. pyogenes infection.
Results. Ligand blot and Biacore analyses revealed that the FbaA fragments harboring a proline-rich repeat domain (RD), but not the N- and C-terminal regions, possessed Fn-binding activity. Immunofluorescent microscopy findings showed that the N-terminus and RD were exposed to external regions, suggesting that the RD serves as an Fn-binding element on live organisms. Specific antibodies were efficiently induced in N-terminus- and RD-immunized mice and demonstrated bactericidal activity against S. pyogenes in vitro. FbaA-immunized mice survived significantly longer as compared to the GST-immunized group following infection with M1 and M49 strains expressing FbaA. In addition, FbaB-immunized mice also survived longer than control mice after challenge with M3 strain expressing FbaB.
Conclusion. The Fn-binding proteins, FbaA and FbaB, are potential vaccine candidates for S. pyogenes infection.
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