| Project/Area Number |
07670295
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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 | Kurume University |
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Principal Investigator |
FUKUMA Toshihide Kurume University, Parasitology, Professor., 医学部, 教授 (90125146)
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| Co-Investigator(Kenkyū-buntansha) |
HARA Tatsuru Kurume University, Parasitology, Research Associate, 医学部, 助手 (30238159)
ESHITA Yuki Kurume University, Parasitology, Lecturer., 医学部, 講師 (10082223)
井上 雅広 久留米大学, 医学部, 助手 (00232562)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Trypanosoma b.gambiense / VSG / VAT / expression switch / regulation of variation / Trypanosoma b. gambiense |
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| Research Abstract |
Bloodstream from of African trypanosomes protect and keep their population serially switching expression of the variant type (VAT)-specific surface glycoprotein (VSG) from one to another. The way of the VSG gene expression is fairly explained, however, the mechanism or regulatory system of the switching itself is unknown. We have been studying on the regulation of Trypanosoma b. brucei gambiense of Wellcome strain. For that purpose we raised monoclonal antibody against KUTat 1, and KUTat 2 and KUTat 3, derived from KUTat 1. When cloned KUTat 3 typanosomes were kept in in vitro culture for 3 months they were replaced by trypanosomes expressing VAT of KUTat 1 or original VAT.On the other hand, the cloned KUTat 1 trypanosomes kept their VAT for more than 6 months. To analyze the change of the ratio of the heterotype to homotype trypanosomes, we tried to apply immunofluorescence technique and immunotoxin. FACS could analyze up to the ratio of 1 : 10^3. Ricin A chain conjugated monoclonal antibody could give lethal effect on bloodstream froms however killed them taking longer times than 24 hrs. The results showed the limitation for determination of the ratio at realtime. The antibody affinity chromatography gave the best result to purify VSG from the surface of bloodstream trypanosomes and it was very useful to apply anti-cross active determinant of VSG,because it is available, regardless of VAT.The biotin labeling method revealed there were several proteins on the surface of bloodstream froms, besides VSG.The several proteins showed a phosphorylated pattern, though it was not affected by the stimulation with anti-VSG antibody. We could clone the VSG genes of metacyclic forms as well as bloodstream forms. The first increased population of bloodstream forms after transformation from metacyclics kept continuously to express metacyclic VSG.Those VSG genes might be a dominant group to be expressed fraquently.
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