| Co-Investigator(Kenkyū-buntansha) |
MATSUI Masanori Saitama Medical School, Dept. of Microbiology, Associate professor, 医学部, 助教授 (50199741)
MORIYA Osamu Saitama Medical School, Dept. of Microbiology, Associate professor, 医学部, 助教授 (40049862)
MACHIDA Sanae Saitama Medical School, Dept. of Microbiology, Assistant, 医学部, 助手 (00219362)
UCHIDA Tetsuya National Institute of Infectious Diseases, Department of Safety Research on Blood and Biological Products, Chief investigator, 安全性研究部, 主任研究官 (50176690)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
1)Immunodominant HLA-A2-restricted CTL epitopes of hepatitis C virus were selected from 27 candidates to be linked on the surface of liposome. The peptide of aa132-140 showed the highest binding capacity to HLA-A2, ability to induce cytotoxicity and interferon-γ production.
2)The peptide 132-140 or the anthrax toxin (LF) containing aa132-140 as the fusion protein was linked on the surface of liposome. When compared, the former showed better ability in sensitization of the target cells, stimulation of memory T cells, and induction of CTL response by in vivo immunization.
3)This vaccine did not activate dendritic cells, but unexpectedly, could induce CTL which revealed cytotoxicity as well as production of interferon-γ.
4)For amplification of the potency of the vaccine, we have cloned mouse IL- 12, IL-23, and IL-27. The cDNAs were inserted into expression plasmid, adenovirus, and vaccinia virus vectors. When each plasmid was co-administered to mice with HCV DNA vaccine for priming, then fol
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lowed by injection of recombinant adenovirus for boosting, they exhibited marked amplification of CTL responses.
5)We sought for the mouse models of persistent virus infection. At first, mouse herpes simplex virus was tested, but it showed vigorous CTL response which was distinct from that is seen in HCV infection. Secondly, Plt mice which lack the gene of the chemokine 6Ckine were tested. When they were infected with vaccinia virus, they showed lower CTL response and the virus was detected for longer period compared to the control mice. Lastly, we tested T-bet knockout mice. T-bet is a transcription factor which regulates differentiation of Th1-type CD4^+ T cells and suppresses Th2 differentiation. These mice showed lower CTL response compared to Plt mice, and the viral persistence was more prominent. To pursue application of liposomal vaccine to the therapy of patients with chronic HCV infection, we are seeking for other viruses to be infected to T-bet knockout mice as the model of chronic hepatitis C..
6)We tried to develop the method to quantify the antigen-specific CD8^+ T cells which is easier to make and less expensive than the tetramer assay. We generated an antigen-presenting cell (APC) expressing HLA-A^*0201 coupled to the enhanced GFP, which delivered GFP to an antigen-specific T cell when pulsed with antigenic peptide. Unfortunately, this APC showed the sensitivity which was not sufficient for practical use. Less
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