| Project/Area Number |
14570468
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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 |
Gastroenterology
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| Research Institution | Osaka University |
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Principal Investigator |
TAKEHARA Tetsuo Osaka University Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (70335355)
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| Co-Investigator(Kenkyū-buntansha) |
TOYAMA Takashi Osaka University Hospital, Medical Staff, 医学部附属病院, 医員(臨床研究)
HIRAMATSU Naoki Osaka University Graduate School of Medicine, Assistant Professor, 医学系研究科, 寄附講座教員 (30362700)
石田 永 大阪大学, 医学部附属病院, 医員(臨床研究)
大川 和良 大阪大学, 医学部附属病院, 医員(臨床研究)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | natural killer cell / natural killer T cell / cancer / liver / α-galactosyl ceramide / interleukin-12 / interferon α / innate immunity / tumor / 腫瘍 / 肝癌 / α-GalCer / CDld / IFN_γ / 抗腫瘍免疫 |
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| Research Abstract |
Innate immune response serves as a first line of defense against carcinogenesis. Since lives contain lots of innate immune effector cells, such as NKT cells and NK cells, innate immune response may be especially important to elicit anti-tumor immunity in the liver. In the present study, we investigated anti-tumor effect elicited by administration of αGalCer or innate cytokine genes against liver tumors in mice. Administration of αGalCer, a ligand for Va14 NKT cell receptor, completely suppressed the growth of BNL hepatoma cells disseminated in the liver of syngeneic mice. αGalCer administration rapidly activated hepatic NKT cells followed by a prolonged activation of NK cells. In vivo depletion of NK cells by anti-asialo GM1 antibody completely abrogated the therapeutic effect. Injection of naked plasmid DNA encoding either IFNα gene or pIL-12 gene, but not mock plasmid, efficiently activated hepatic NK cells for 1 week and completely eradicated hepatic metastasis of CT-26 colon tumor cells. The rejection is dependent on the presence of NK cells, since in vivo depletion of NK cells by injecting asialoGM1 antibody abolished the anti-tumor activity of both gene therapies. The mice that had been protected from hepatic tumor by both therapies were challenged with subcutaneous inoculation of original tumor cells. αGalCer-or pIL-12-injected mice completely rejected re-challenged tumor cells, and pIFNa-injected mice did partially. The present study revealed that injection of αGalCer and innate cytokine genes such as IL-12 and IFNα protect from hepatic metastasis in a NKT cell or NK cell dependent manner. Furthermore, tumor rejection provoked by activation of innate immune cells efficiently induced acquired immune response against original tumor cells.
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