• IMMUNE NETWORK
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• v.2 no.1
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• pp.41-48
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• 2002

Background: Viral antigens presented on the cell surface in association with MHC class I molecules are recognized by CD8+ T cells. MHC restricted peptides are important in eliciting cellular immune responses. As peptide antigens have a weak immunigenicity, pH-sensitive liposomes were used for peptide delivery to induce effective cytotoxic T lymphocyte (CTL) responses. In the previous study, as the HBx peptides could induce specific CTLs in vitro, we tested whether the HLA-A2/$K^b$ transgenic mice that were immunized by HBx-derived peptides could be protected from a viral challenge. Methods: HBx-peptides encapsulated by pH-sensitive liposomes were prepared. $A2K^b$ transgenic mice were immunized i.m. on days one and seven with the indicated concentrations of liposome-encapsulated peptides. Three weeks later, mice were infected with $1{\times}10^7pfu$/head of recombinant vaccinia virus (rVV)-HBx via i.p. administration. The ovaries were extracted from the mice, and the presence of rVV-HBx in the ovaries was analyzed using human TK-143B cells. IFN-${\gamma}$ secretion by these cells was directly assessed using a peptide-pulsed target cell stimulation assay with either peptide-pulsed antigen presenting cells (APCs), concanavalin A ($2{\mu}g/ml$), or a vehicle. To generate peptide-specific CTLs, splenocytes obtained from the immunized mice were stimulated with $20{\mu}g/ml$ of each peptide and restimulated with peptide-pulsed APC four times. The cytotoxic activity of the CTLs was assessed by standard $^{51}Cr$-release assay and intracellular IFN-${\gamma}$ assay. Results: Immunization of these peptides as a mixture in pH-sensitive liposomes to transgenic mice induced a good protective effect from a viral challenge by inducing the peptide-specific CD8+ T cells. Mice immunized with $50{\mu}g/head$ were much better protected against viral challenge compared to those immunized with $5{\mu}g$/head, whereas the mice immunized with empty liposomes were not protected at all. After in vitro CTL culture by peptide stimulation, however, specific cytotoxicity was much higher in the CTLs from mice immunized with $5{\mu}g/head$ than $50{\mu}g/head$ group. Increase of the number of cells that intracellular IFN-${\gamma}$ secreting cell among CD8+ T cells showed similar result. Conclusion: Mice immunized with XEPs within pH-sensitive liposome were protected against viral challenge. The protective effect depended on the amount of antigen used during immunization. XEP-3-specific CTLs could be induced by peptide stimulation in vitro from splenocytes obtained from immunized mice. The cytotoxic effect of CTLs was measured by $^{51}Cr$-release assay and the percentage of accumulated intracellular IFN-${\gamma}$ secreting cells after in vitro restimulation was measured by flow cytometric analysis. The result of $^{51}Cr$-release cytotoxicity test was well correlated with that of the flow cytometric analysis. Viral protection was effective in immunized group of $50{\mu}g/head$, while in the in vitro restimulation, it showed more spectific response in $5{\mu}g$/head group.

• Proceedings of the Microbiological Society of Korea Conference
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• 2009.05a
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• pp.98-98
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• 2009

• The Journal of Korean Medicine
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• v.20 no.3 s.39
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• pp.54-65
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• 1999

Objectives: Hepatoma is a very serious disease in Korea and vvorldwiclc. Hepatitis B vims (HBV) has proved the most significant cause of hepatoma. We canied out this study to investigate the effect of Acanthopanax sessilifloms on inhibiting cell proliferation and DNA synthesis in HepG2.2.15 cell line and on inhibiting phosphorilation of oncogene (MAP kinase) in NIT/3T3-HBx ceIl. Methods: To investigate the anti-cancer effect of Acanthopanax sessiliflorus, we did the CellTiter 96 Aqueous Non-radioactive Cell Proliferation assay (Promega); MTS/PMS assay, [$^3H$]-thymicline incorporation assay, and we measured the gene expression through westem blotting. Results: Acanthopanax sessiliflorus showed an inhibiting effect on the increase of HepG2.2.15 in the NTS/PMS assay. It also showed an inhibiting effect on DNA synthesis of HepG2.2.15 in the [$^3H$]-thymidine incorporation assay. Acanthopanax sessiliflorus showed an inhibiting effect of phosphorilation of MAP kinase in HBV - X genes. too. Conclusions: The results suggested that this herb had an anti cancer effect. We may discover an effective anti-cancer herb medicine through further studies on this herb medicine.