| Project/Area Number |
13670250
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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 |
寄生虫学(含医用動物学)
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| Research Institution | Nagasaki University |
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Principal Investigator |
UEMURA Haruji Nagasaki University, Institute of tropical Medicine, Assistant Professor, 熱帯医学研究所, 講師 (60184975)
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| Co-Investigator(Kenkyū-buntansha) |
FUJII Shigeru Kansai Medical University, School of Medicine, Professor, 医学部, 教授 (60144482)
KANBARA Hiroji Nagasaki University, Institute of tropical Medicine, Professor, 熱帯医学研究所, 教授 (20029789)
YANAGI Tetsuo Nagasaki University, Institute of tropical Medicine, Assistant Professor, 熱帯医学研究所, 助手 (10174541)
NAKAZAWA Shusuke Nagasaki University, Institute of tropical Medicine, Assistant Professor, 熱帯医学研究所, 助手 (20180268)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2002: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Trans-sialidase / Trypanosoma / Chagas disease / African sleeping sickness / Cell invasion / GPI-anchor / Escape / シャガス病 / シアル酸 / 遺伝子ファミリー / シャガ病 |
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| Research Abstract |
The parasitic Trypanosomes can not synthesize sialic acid but express a unique enzyme, trans-sialidase (TS) in order to incorporate sialic acids on their surface. This enzyme has been shown to be important for parasite to survive in host defense environment and to invade to host cells. The TS are encoded by several gene families and its expression is strongly controlled by stage specific manor.
We have presented that TS and parasite surface sialic acids are essential for the African trypanosome Trypanosoma brucei, to protect the parasite from the digestive condition in the mud-gut of Tsetse flies. T.brucei expresses TS at the insect stage. The parasite lacking sialic acids due to a defective generation of GPI-anchored trans-sialidase could not survive in the intestine, but regained the ability to survive when sialylated by means of soluble trans-sialidase.
We also have shown that TS in T. cruzi is important for parasite escape from the paraitophorous vacuole (PV). T.cruzi trypomastigotes (TCT) and metacyclic trypomastigotes (MT) attached to and invaded mammalian host cells HeLa or CHO cells equally, but the former TCT escaped from the vacuole earlier than MT. The trypomastigote TS was expressed on the surface of metacyclic formed and used for cell invasion experiments. The transfected parasites could efficiently escaped from the PV and this result indicate that increased TS enzyme activity in TCT is important for efficient earlier exit from the PV to cytoplasm and subsequent differentiation into amastigotes.
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