Induction of cytotoxic lymphocyte response to hepatitis C virus using anthrax toxin-mediated antigen delivery system

我们研究了丙型肝炎病毒保护性抗原(PA)和重组致死因子(LF)表位诱导细胞毒性T淋巴细胞(CTL)的作用。融合蛋白(LMGYIPLVGA：#1)可诱导与编码核心表位的重组质粒DNA相似的CTL反应。这些结果表明PALF的抗原递送系统有可能成为丙型肝炎疫苗的候选疫苗。在肌肉、皮下和腹膜免疫途径的筛选中，肌内途径似乎更好。为了比较PALF#1体外冲击的巨噬细胞株J774A.1和常规PALF#1溶液的免疫效果，前者获得了较强的CTL应答。与抗原提呈细胞相比，树突状细胞比J774A.1更能有效地诱导CTL应答。吸附在乳胶小球上的PA和LF1免疫可引起较强的CTL反应。当PALF#L与抗CD40和GM-CSF联合作用时，CTL应答至少是PALF#1乳胶微球的2倍。PALF#1诱导的CTL可在表达核心蛋白的重组痘苗病毒感染后，内源性杀伤表达表位的靶细胞。这些结果表明，PA和LF表位的应用是一种有效的CTL疫苗的分子工具。这一抗原递送系统的研究结果可能为丙型肝炎疫苗开发的新途径提供一些有用的信息。

We have investigated the protective antigen (PA) and recombinant lethal factor (LF) expressing epitope of hepatitis C virus (HCV) to induce cytotoxic T lymphocytes (CTL). Fusion protein of LF with epitope of core region (LMGYIPLVGA : #1) induced CTL response comparable with recombinant plasmid DNA encoding the core epitope when immuinzed mice with PA.In addition to #1 epitope, CTL activity was detected in another core epitope (YLLPRRGPRL : #5). These results indicate that antigen delivery system of PALF may be useful as HCV vaccine candidate. In the route screening for immunization among the intramuscle, subcutis and intraperitoneum, intra- muscular route seems to be better. To compare the immunization condition between the J774 A.1, macrophage cell line, pulsed with PALF#1 ex vivo and conventional solution of PALF#1, strong- er CTL response was obtained in the former immunization protocol. When compared the antigen presenting cells, dendritic cells was more efficient to elicite CTL response than the application by J774 A.1. Immunization with PA and LF#1 adsorbed to latex beads elicited strong CTL response. When latex beads were treated with PALF#l together with anti-CD40 and GM-CSF, CTL response was at least 2-fold more efficiently than was PALF#1 latex beads. CTL induced by PALF#1 could kill the targets expressed the epitope endo- geneously after infection of recombinant vaccinia virus expressing core protein. These findings are indicating that application of PA and LF-epitope is an efficient molecular tool to use as CTL vaccine. The findings of this antigen delivery system may give us some useful informations for new approach concerning HCV vaccine development.