| Project/Area Number |
16390204
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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 |
Gastroenterology
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| Research Institution | Department of Neurology and Neurological Science, Tokyo medicak and Dental University |
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Principal Investigator |
YOKOTA Takanori Tokyo medicak and Dental University, Department of Neurology and Neurological Science, Associate Professor, 大学院・医歯学総合研究科, 助教授 (90231688)
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| Co-Investigator(Kenkyū-buntansha) |
AKARI Hirofumi National Institute of Biomedical Innovation, Tsukuba Primate Research Center, 霊長類医科学研究センター, 研究リーダー (20294671)
ENOMOTO Nobuyuki University of Yamanashi, Department of Internal Medicine, School of Medicine, 医学工学総合研究部, 教授 (20251530)
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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 |
¥14,300,000 (Direct Cost: ¥14,300,000)
Fiscal Year 2005: ¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 2004: ¥7,400,000 (Direct Cost: ¥7,400,000)
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| Keywords | RNA interference / siRNA / cationic vector / Hepatitis C / tamarin / marmoset / GBV-B / interferon / インターフェロン / HCV |
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| Research Abstract |
We synthesized the siRNA oligonucleotides targeting to the of GBV-B genome which is different from that of the corresponding sequence of HCV genome by only two nucleotides. This site was selected from 5' untranslated region, the most conservative region in the GBV-B/HCV genome, making the siRNA resistant to the mutation of the virus. For the delivery of the siRNA to the liver, we have developed a cationic liposome, LIC-101, which consists of new novel cationic lipid analogue.
The five marmosets were used in this study. The 1.0, 2.5 and 5.0mg/kg of siRNA to GBV-B formulated by LIC-101 were slowly administered from the saphenous vein of the marmosets for three days. On the second day, GBV-B virus particles were directly injected to the liver. We could observe the dramatic and dose-dependent effect of the GBV-B siRNA/LIC101 to inhibit the replication GBV-B virus ; The 5.0mg/kg siRNA/LIC-101 completely suppressed the replication of GBV-B for more than 4 months after inoculation of the virus, even though the siRNA was injected for only three days. Unexpectedly, the control siRNA/LIC-101also can delay the virus replication. Since the control siRNA/LIC-101 induced the serum interferons α and γ, this delay of virus replication by the control siRNA/LIC-101 on the viral replication should be caused by an anti-viral effect of the induced interferons. In contrast, GBV-B siRNA/LIC-101 induced much less interferons than the control siRNA/LIC-101. Therefore, inhibitory effect of GBV-B siRNA/LIC-101 was considered to include those by both siRNA and interferons. Since synthetic siRNA formulated with lipid vectors is recognized through toll-like receptors located in the endosomal membrane and activates immune system in a sequence dependent manner.
In conclusion, we succeeded to inhibit replication of GBV-B in liver of monkey with siRNA. We are trying the new method to suppress interferon response to escape the side effect.
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