以往的研究表明非甲基化胞嘧啶鸟嘌呤二核苷酸为基元构成的特定结构是一种很有希望的候选疫苗佐剂。为了研究增加CpG基元的汉坦病毒核蛋白基因疫苗的免疫作用,在本实验中,将重组真核表达质粒pcDNA3.1+S(ISS)直接肌注免疫BALB/c 小鼠,分别用ELISA法检测血清特异性抗体的变化,MTT法检测T细胞增殖反应,以及用ELISA kit检测免疫鼠脾细胞上清液中细胞因子IL 4和IFN γ的动态变化,从而了解免疫鼠的体液免疫反应和细胞免疫反应。结果显示pcDNA3.1+S(ISS)接种组的小鼠血清抗体水平、T细胞增殖反应以及细胞因子IFN γ的产生水平较对照组pcDNA3.1+S和空载体pcDNA3.1+接种组的要高。而细胞因子IL 4 较对照组却无明显变化。由此可见,增加CpG基元的质粒能够增强其所诱导的免疫反应,可用于那些需要借助强有力细胞免疫来清除病原体的疫苗研制中。

Bacterial and synthetic DNA containing CpG dinucleotides in specific sequence contexts are being tested as immune adjuvants in many disease settings. To study the immune responses induced by the CpG-enhanced plasmid DNA vector encoding hantavirus nucleiocapsid protein. BALB/c mice were immunized three times by intramuscular inoculations of the recombinant eukaryotic expression vector pcDNA3.1+S(ISS) at 2-wk intervals. To evaluate the humoral and cellular immune responses, antigen-specific lymphocyte proliferation and antibody production were assayed by MTT method and ELISA,respectively. In addition,the level of interleukin-4 and interferon-γ in the splenic lymphocytic cultured supernatant were detected with ELISA kit at various times. We found that the group immunized with pcDNA3.1+S(ISS) had more Ab response against NP compared with the control group over the period, specially at 35d and 42d,after the primary immunization. The antibody mean titre of the group immunized with pcDNA3.1+S(ISS) was increased to a