| Co-Investigator(Kenkyū-buntansha) |
MATSUURA Yoshifumi Keio university, School of Medicine, Assistant, 医学部, 助手 (90317157)
HASEGAWA Hirotoshi Keio university, School of Medicine, Instructor, 医学部, 助手 (00218455)
JINNO Hiromitsu Keio university, School of Medicine, Instructor, 医学部, 助手 (20216261)
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| Research Abstract |
There are many hepatopathies that may be candidates for gene therapy. Gene therapy needs a vector that is carried together with its genes into a target cell or organ. Desirable vectors should be extremely safe, have good transfection efficiency, and demonstrate a high specificity for their target. In 1992, Kuroda et al. reported on the large amount of HBsAg envelope L particles that could be synthesized in yeast cells. HBV envelope L particles overproduced by yeast are hollow nanoparticles(average diameter 80nm) displaying the pre-S1 peptide indispensable for human liver-specific infection. Either a GFP(green fluorescence protein)-expression plasmid or a fluorescent dye(calcein) was incorporated into L particles by electroporation, and directly used for the transfection of various cells in vitro. Either GFP- or calcein-derived fluorescence was observed only in human liver-derived cells such as NuE and HepG2 not but WiDr and A431. We transplanted human hepatocellular carcinoma cells and human colon cancer cells subcutaneously in nude rats or nude mice. L particles with. GFP-expression plasmide or carcein were infected into the tumor-bearing nude rats or mice through tail vein. After 7 days, fluorescence was observed specifically in the subcutaneous heptocellular carcinoma, but not was observed in the subcutaneous colon cancer, brain, heart, lung, liver, spleen, kidney, adrenal gland, intestine, or muscle of rats or mice. When the human clotting factor IX gene, a therapeutic gene for hemophilia B, was transferred into the xenograft model by the L particles, therapeutic factor IX levels were obtained in the plasma for at least 1 month. In conclusion, HBsAg L particles showed a specific recognition ability for human-derived liver tissue and demonstrated a transgenie ability in an in vivo system.
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