| Project/Area Number |
07670282
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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 School of Medicine |
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Principal Investigator |
YAMASHITA Keizo Nagasaki University School of Medicine, Assistant, 医学部, 助手 (00239964)
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| Co-Investigator(Kenkyū-buntansha) |
YANO Akihiko Chiba University School of Medicine, Professor, 医学部, 教授 (20135122)
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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 |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Toxoplasma gondii / mouse / protective immunity / strain-specific antigen / stage-specific antigen / CD8^+ T cells / macrophage / gamma interferon / 活性化マクロファージ / トキソプラズマ / T細胞 / 放射線処理 |
|---|
| Research Abstract |
Toxoplasma godii (Tx)-specific CD8^+ T cells are one of the principal effector populations in the protection against lethal toxoplasmic infection in mice. To understand the mechanism underlying the CD8^+ T cell-mediated protection, we generated Tx-infected cell-specific CD8^+ T cell line that was cytolytic for Tx-infected, MHC-matched target cells. Parasite number was counted by PCR-based enumeration of the copy number of Toxoplasma SAG-1 gene. The parasites did not reduce in number even when 80% of the infected target cells were lysed by Tx-specific CD8^+ T cells. In contrast, parasites reduced by 90% when infected target cells were co-cultured with Tx-specific CD8^+ T cells in the presence of gamma IFN-activated bone marrow macrophages. This reduction was not dependent with the specificity of the effector CD8^+ T cells ; parasite also reduced in number when infected target cells were lysed by allo-antigen specific CD8^+ T cells. Furthermore, parasites did not proliferate nor reduce in number in gamma IFN-activated macrophages after infection. These results indicated that, although intrahost-cell parasites remaine viable after CD8^+ T cell-mediated host cell lysis, they are killed by IFN-activated macrophages. The precise mechanisms under which intrahost-cell parasites are killed by gamma IFN-activated macrophages are now under investigation.
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