小鼠及家兔对丙型肝炎病毒多表位DNA疫苗免疫应答的研究

目的 探讨HCV复合多表位DNA疫苗的可行性。方法 把HCV多表位抗原基因PCX克隆到真核表达载体pREP9(RSV启动子）及pcDNA3(CMV启动子）中，构建真核表达载体pREP9/PCX及pcDNA3/PCX。将其肌肉注射免疫小鼠及家兔，检测特异性体液免疫和细胞免疫的水平，并观察免疫小鼠的安全性。结果 质粒pREP9/PCX及pcDNA3/PCX于免疫后第6wk和第10wk时，开始可检测到抗GZ-PCXIgG,随后抗体滴度逐渐升高，但水平较低持续时间较短，pcDNA3/PCX肌肉注射免疫家兔后，于第8wk开始出现特特抗体，至3个月后滴度升至1：3200随后也开始下降，免疫小鼠及家免可诱发针对GZ-PCX融合蛋白的迟发型超敏反应，并刺激淋巴细胞转化，免疫后小鼠的体重正常，肝脾脏未见明显肿大，具有良好的安全性。结论 HCV多表位基因可诱发特异性免疫应答且安全性。结论ＨＣＶ我表位基因可诱发特异性免疫应答且安全性好，为ＨＣＶ疫苗的研究提供一定的理论及实验依据。

Immunogenicity of a multiple epitope antigen gene of hepatitis C virus in mice and rabbits

Aim To explore the possibility of the multiple epitope DNA vaccines of hepatitis C virus (HCV). Methods A synthetic multiple epitope antigen gene PCX of HCV was cloned into vector pREP9(RSV promoter) and pcDNA3 (CMV promoter) to construct eukaryotic expression vectors pREP9/PCX and pcDNA3/PCX, then they were used to immunize mice and rabbits, the titer of specific humoral and cellular responses were detected and their safety were observed. Results In mice, specific anti-GZ-PCX antibody(IgG) was lower than 1: 1 000 and did not persist well. In rabbits, the highest titer of anti-GZ-PCX IgG reached at 1: 3 200 and remained for about one month. Delayed type hypersensitivity reactions (DTH)and proliferation response of peripheral lymphocytes were induced by GZ-PCX antigen. Body weights of immunized mice were normal and no obvious toxic reaction was observed. Conclusion The multiple epitope antigen gene of HCV could induce specific immune responses without obvious toxicity and it might be able to serve as an effective HCV vaccine candidate.