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为构建含日本血吸虫抱雌沟蛋白(SjGCP)完整ORF的核酸疫苗,评估该核酸疫苗在小鼠体内诱导抗血吸虫感染的免疫保护效果及其保护机制,将编码日本血吸虫大陆株抱雌沟蛋白基因ORF片段克隆到真核表达载体pVAX1中,用重组质粒pVAX1-SjGCP三次肌肉注射BALB/c小鼠,攻击感染血吸虫尾蚴,攻击感染后第42天剖杀小鼠冲虫,计算减虫率及肝和粪便的减卵率,评估其免疫保护效果。用流式细胞术(FCM)检测第3次免疫后小鼠淋巴细胞亚群CD4+、CD8+占总淋巴细胞的百分比及细胞因子IL-4、IFN-γ表达水平,探讨核酸疫苗的免疫机制。结果显示,小鼠经pVAX1-SjGCP质粒免疫后诱导了31.9%的减虫率,以及47.85%、68.04%的肝减卵率和粪便减卵率,与PBS组差异显著;pVAX1-SjGCP免疫组淋巴细胞亚群CD4+、CD8+百分比增加,细胞因子IFN-γ及特异性IgG水平提高,与pVAX1组差异显著。结果表明,血吸虫抱雌沟蛋白基因DNA疫苗能够诱导宿主细胞免疫和体液免疫应答,产生Th1/Th2型混合的细胞免疫反应,具有一定的抗血吸虫感染的免疫保护效果。
To construct a nucleic acid vaccine containing the complete ORF of Schistosoma japonicum female sporozoite protein (SjGCP), the immunological protective effect and protection mechanism of the nucleic acid vaccine against schistosoma infection in mice were evaluated. The gene encoding female genitalium ORF fragment was cloned into the eukaryotic expression vector pVAX1. BALB / c mice were intramuscularly injected with the recombinant plasmid pVAX1-SjGCP three times to challenge the infected cercariae of Schistosoma japonicum. On the 42nd day after infection, the mice were killed and the worm reduction rate and liver And droppings of excrement to assess their immune protective effect. Flow cytometry (FCM) was used to detect the level of CD4 +, CD8 +, total lymphocytes and IL-4 and IFN-γ in mice after the third immunization, and to explore the immune mechanism of the vaccine. The results showed that mice immunized with pVAX1-SjGCP induced a worm reduction rate of 31.9% and a rate of 47.85% and 68.04% respectively, which was significantly different from that of the PBS group The percentage of CD4 + and CD8 + increased, the level of cytokine IFN-γ and specific IgG increased, which was significantly different from pVAX1 group. The results showed that the DNA vaccine of Schistosoma japonicum containing female genitalium DNA induced host cell immune response and humoral immune response, resulting in Th1 / Th2 mixed cellular immune response, with a certain degree of immune protection against infection by schistosome.