| Project/Area Number |
15591330
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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 |
General surgery
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TAKAYAMA Takuya The University of Tokyo, Institute of Medical Science, Research Associate, 医科学研究所, 助手 (10332579)
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| Co-Investigator(Kenkyū-buntansha) |
TAHARA Hideaki The University of Tokyo, Institute of Medical Science, Professor, 医科学研究所, 教授 (70322071)
TSUNODA Takuya The University of Tokyo, Institute of Medical Science, Lecturer, 医科学研究所, 講師 (30275359)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2004: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | denderitic cell / in vivo electroporation / Flt3L / IL-18 / chemokine / SLC / in vitro electroporation |
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| Research Abstract |
1)IN VIVO MOBILIZATION AND MATURATION OF DENDRITIC CELLS USING FLT3L GENE THERAPY
The clinical application of DCs induced from peripheral monocytes in vitro has been initiated as a promising immunological therapy against cancer. If the same type of immuno-stimulator could be achieved without in vitro manipulation, it might be very convenient in clinical settings. In this study, we performed systemic gene transfer of Flt3L using in vivo electroporation of Flt3L plasmid DNA (Flt3L-IVE) in pretibial muscles in order to determine the effects on DCs in situ. The number of DCs was significantly increased and showed highly co-stimulatory molecules expressions both in spleen and bone marrow after Flt3L-IVE compared to those of control groups. Immunohistochemical evaluation revealed that not only DCs but also CD8 and CD4 positive cells were significantly infiltrated into the local tumor site compared with those of control and remained in the tumor 21 days after a single Flt3L-IVE. However, anti-
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tumor effects of Flt3L-IVE were not significant in MCA205 established tumor. These results suggest that Flt3L gene transfer using in vivo electroporation could mobilize DCs into tumor site. Additional means to induce maturation of these DCs could have positive impact on anti-tumor effects of this strategy.
2)INDUCTION OF POTENT AND SYSTEMIC ANTITUMOR IMMUNITY USING INTRA-TUMORAL GENE TRANSFER OF IL-18 IN COMBINATION WITH FLT3L THERAPY
Interleukin-18 (IL-18), which induces IFN-γ production and enhances the cytolytic activity of NK cells, is considered to be a good candidate to be used for cancer immunotherapy. However, we have already found that treatment with systemic or local administration of IL-18 alone was not enough to induce a potent systemic anti-tumor immunity. On the other hand, we also have reported that dendritic cells (DCs) can capture tumor antigens from tumor cells killed by NK cells activated with IL-18 and efficiently induce tumor-specific CTL in vitro. In order to enhance the systemic anti-tumor response induced by local administration of IL-18 in vivo, we examined the effects o」 the combination therapy with IL-18 and Flt3 ligand (Flt3L). The mice received intra-dermal inoculation of MCA205 fibrosarcoma in the bilateral flanks. On day 5 and 12, mice were treated with in vivo electroporation (IVE) with DNA plasmids carrying cDNA of human Flt3L or EGFP to bilateral hind legs. As the combination therapy, some of the mice were also treated with intra-tumoral injection of adenoviral vector carrying IL-18 gene (Ad.IL-18) or EGFP gene (Ad.EGFP). In the treated tumors, significant anti-tumor effect was observed in mice treated with Ad.IL-18 alone and the ones treated with combination therapy of Flt3L-IVE and Ad.IL-18 when compared to those mice with control (p<0.01). The combination treatment with Ad.IL-18 resulted in the more potent anti-tumor response when compared to Flt3L-IVE treatment alone (p<0.01), and the complete eradication was observed more frequently (100% vs 33% : p<0.05) in mice treated with the combination therapy when compared to ones with Ad.IL-18 treatment alone. In the un-injected tumors, only the combination therapy showed significant anti-tumor. Lymphoid cells in regional lymph nodes of the mice treated with the combination therapy showed a significant cytolytic activity against MCA205. Moreover, cytolytic activity of the combination therapy against YAC-1 (NK target) was significantly higher than that of Ad.IL-18 treatment alone (p<0.05). These results suggested that local gene transfer of IL-18 combined with DCs mobilization in situ with Flt3L may enhance the anti-tumor effect and induce a potent systemic anti-tumor immunity. Less
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