| Project/Area Number |
16591053
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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 |
Pediatrics
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| Research Institution | Kitasato University |
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Principal Investigator |
NAKAYAMA Tetsuo Kitasato University, Kitasato Institute for Life Sciences, Professor, 北里生命科学研究所・杏林大学 (60129567)
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| Co-Investigator(Kenkyū-buntansha) |
FUJINO Motoko Kitasato University, Kitasato Institute for Life Sciences, Research Associate, 北里生命科学研究所, 助手 (30317185)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Measles virus wild strains / Measles virus vaccine strain / N protein / P protein / L protein / Mini-genome assay / Replication・transcription / 麻疹ウイルス 野生株 / 麻疹ウイルス ワクチン株 |
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| Research Abstract |
【Background】Wild-type measles virus strains are classified into 23 genotypes but there is limited information on the characteristics of circulating wild types. Measles virus is believed to be fragile in heat and the AIK-C vaccine strain has unique characteristics of temperature sensitivity (ts). 【Objective】Several strains of Chicago-type D3 and D5 grew well at 39 C with similar growth rate at 33-37 C. Objective of this study is to investigate the molecular bases of high efficiency of virus growth at 39 C of non-ts wild type viruses. 【Materials and Methods】Mvi/Tokyo.JPN/99-Y [Chicago-type D3], Mvi/Tokyo.JPN/2000-KA[D5], Mvi/Tokyo.JPN/87-K[D3], Edmonston wild type and AIK-C vaccine strain were used. We developed mini-genome assay for the analysis of measles virus replication and transcription. Recombinant N and P expression plasmids were constructed to identify the critical domain(s) for non-ts characteristics. Mini-genome competition assay was performed using P protein fragment expression plasmids to investigate the binding domains of P protein.【Results and Discussion】Mini-genome assay was performed at 32 C and 39 C and homologous combination of the N and P expression plasmids derived from Mvi/Tokyo.JPN/99-Y or Mvi/Tokyo.JPN/2000-KA showed high levels of luciferase activity at 32 C or 39C. Whereas, homologous combination of the AIK-C strain showed no luciferase activity at 39 C. N0 binding domain of the P protein derived from Mvi/Tokyo.JPN/99-Y was critical domain for high virus growth at 39 C and homologous combination of N protein tail domain and P protein X domain was also responsible for additional N-P interaction from the results of mini-genome assay using chimerical expression plasmids. Luciferase activity was inhibited by the addition of P protein 376 amino acids from N0 binding domain to coiled coil region. This region is critical region responsible for high virus growth at 39C and N-P-L binding.
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