关键词: 多表位, 丙型肝炎病毒, DNA疫苗, 干扰素&gamma, 最低限度免疫定义基因表达,

Abstract:

Objective: To study the feasibility of hepatitis C virus (HCV)multi-epitope DNA vaccines prepared by minimalistic immunologically defined gene expression,and to clarify its potential application value in the field of DNA vaccines.Methods: A minimalistic immunologically defined gene expression DNA vaccine(1 346 bp) containing CMV promoter,HCV 1b subtype multi-epitope, and bovine growth hormone (BCG) polyA sequence was prepared by artificial synthesis and PCR methods,then it was named M-HCV-epi.A control DNA fragment,which structure gene was replaced by a DNA fragment without homologous to HCV,was prepared and named V-pcDNA3.1. A total of 12 ICQ mice were randomly divided into experimental group(n=6) and control group(n=6);the mice were subcutaneously injected with M-HCV-epi and V-pcDNA3.1 with the dosage of 20 μg,respectively.The levels of interferon-γ (IFN-γ) mRNA in spleen cells of the immunized mice were detected by QRT-PCR method. A total of 3 HCV 1b subtype epitope polypeptides and a control polypeptide were synthetically prepared.The levels of IFN-γ in culture supernatant of spleen cells were detected by ELISA method after the cells were stimulated with the polypeptides prepared above.Results: Compared with control group,the level of IFN-γ mRNA in spleen cells of the mice in experiment group was increased to (1.50±0.18) times(P<0.05); compared with control group,the level of IFN-γ in the culture supernatant of spleen cells of the mice in experiment group was increased (P<0.05).Conclusion: The HCV multi-epitope DNA vaccine with minimalistic immunologically defined gene expression can induce the cellular immune response,and may have application values in the field of DNA vaccines.

Key words: hepatitis C virus, minimalistic immunologically defined gene expression, muti-epitope, DNA vaccine, interferon γ.