| Project/Area Number |
08457082
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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 |
寄生虫学(含医用動物学)
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| Research Institution | NAGOYA CITY UNIVERSITY |
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Principal Investigator |
OHTA Nobuo Nagoya City University, Medical Zoology, Professor, 医学部, 教授 (10143611)
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| Co-Investigator(Kenkyū-buntansha) |
ITOH Makoto Aichi Medical University, Parasitology, Associate Professor, 助教授 (90137117)
MARUYAMA Haruhiko Nagoya City University, Medical Zoology, Associate Professor, 医学部, 助教授 (90229625)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1998: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | Schistosomiasis / Plasmodium chabaudi / Strongyloides venezuelensis / cytokine / Nitric oxide / Th1 / Th2 / host-parasite interaction / tumor rejection / Schistosoma mansoni / UV♀1 / 宿主・寄生虫相互作用 / Schistosoma japonicum / Plasmodium chaboudi / 感染感受性 / 虫卵肉芽腫 / Leishmania major / IgGサブクラス / RL♂1 |
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| Research Abstract |
This study was conducted to uncover effects of helminth-driven immunomodulation on concurrent infections of other unrelated parasites in mice. Murine hosts infected with Schistosoma mansoni are thought to be in Th2-dominant situation, which might have detectable effects for the bio-defence system. Results in this study suggest that schistosome-driven Th2 response induced strong protective immunity against Strongyloides venezuelensis infection. On the other hand, S.mansoni infection did not have any detectable effects on Leishmania major infection for which Th1 response is hightly protective in particular mice strains. C57BL/6 mice are resistant against L.major through induction of Th1-dominant response, however, these mice were still resistant even in concomitant infection of S.mansoni. Schistosome-driven Th2 response seemed to impair killer T cell response in mice implanted with UV*1 fibrosarcoma cells. Unexpected results were observed in case of Plasmodium chabaudi infection in A/J mice, which is highly susceptible to P.chabaudi infection. When A/J mice were infected with S.mansoni, parasitemia was significantly suppressed, and moreover, no mice died of malaria, while all A/J mice infected with P.chabaudi alone died within 7 days. Together with these results, we conclude that schistosome infection could have deep effects on the bio-defence system of infected hosts, although the effects are highly heterogenous. Such effects are determined not only by host-schistosome interaction, but also by parasite-parasite interaction. The complicated mechanisms for determining the bio-defence system in infected hosts are involved in disease susceptibility of host population, and eradication of particular parasites might provide unexpected risk of another infective disease.
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