| Project/Area Number |
09470085
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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 |
Virology
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| Research Institution | Osaka University |
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Principal Investigator |
YAMANISHI Koichi Osaka University Medical School, Professor, 医学部, 教授 (10029811)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEDA Kazuhiko Osaka University Medical School, Assistant Professor, 医学部, 助手 (70294072)
ISEGAWA Yuji Osaka University Medical School, Assistant Professor, 医学部, 助手 (20184583)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 1998: ¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 1997: ¥9,300,000 (Direct Cost: ¥9,300,000)
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| Keywords | HHV 6 / variant / full sequence / glycoprotein / neutralizing antibody / chemokine / chemokine receptor / signal transduction / 糖蛋白 / gH / 中和抗体 |
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| Research Abstract |
Two variants of Human herpesvirus 6 (HHV-6) have been distinguished based on differences in those properties. We have determined the complete DNA sequence of HHV-6 strain HST, the causing agent of exanthem subitum, which belongs of variant B. Thus 114 potential open reading frames were identified within the 161573-bp contiguous sequence of the entire HHV-6 genome, as well as some genes with remarkable differences in amino acid identity that may lead to characteristic differences of two variants. Also, we have carried out typing of 14 different strains belonging to HHV-6A or B by PCR using variant-specific primers.
The U12 gene is expressed late in infection from a spliced mRNA. The U12 gene was cloned, and the protein was expressed in K562 cells. U12 functionally encoded a calcium-mobilizing receptor for b-chemokines such as RANTES, MIP-1a, MIP-1b, and MCP-1 but not for the a-chemokine IL-8.
The U83 gene is expressed late in cells infected with HHV-6B. The recombinant U83 was expressed and purified from supernatant of transfected cos-7 cells. The U83 protein induced transient calcium mobilization and exhibited an efficient chemotaxis activity for monocytic cell line THP-1 cells.
HHV-6 gHs from strain U1102 and strain HST were expressed in a T7-vaccinia virus transient expression system. OHV3 reacted with HST gH, but not with U1102 gH, in an immunoprecipitation and an indirect immunofluorescence assays. In addition, OHV3 reacted with chimeric gHs, formed between U1102 gH and HST gH, containing amino acids 272 to 422 of HST gH. Sequence comparison between U1102 and HST showed seven amino acid differences in this region. Site-specific mutations were introduced into these positions and then reactivity against OHV3 was investigated. The argenine at position 389 of HST gH was shown to be a determinant of the HHV-6B-specific reactivity of OHV3.
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