中文摘要：

目的：通过在小鼠病毒性心肌炎动物模型研究短双链小干扰RNA（small interfering RNA,siRNA）对病毒感染和复制的抑制作用,研究RNAi在治疗病毒性疾病的可行性。方法：利用质粒载体将siRNA转染至HeLa细胞和Balb-c小鼠后感染病毒,荧光显微镜观察GFP表达量观察细胞内质粒转染效率和持续时间,通过病毒致细胞病变作用（CPE）保护实验病毒空斑形成实验检测病毒受抑制程度,动物模型中观察动物死亡率和易感组织病理变化评价siRNA的保护作用。结果：在HeLa细胞中针对CVB3 2B区的siRNA能显著抑制柯萨奇病毒B3的感染和复制,抑制率可达90%。动物模型中siRNA质粒可改善动物存活率（30%）,并降低易感脏器中病毒含量,减轻病理反应。结论：针对CVB3基因组2B区的siRNA在病毒性心肌炎动物模型中具有保护作用。

英文摘要：

Objective：To investigate the inhibition of coxsackievirus B3（CVB3）in animal myocarditis by plasmid-dilivered short hairpin RNAs and to evaluate the prevention of viral production.Method：Plasmid-directed siRNA was transfected into HeLa cells by Lipofectamine LTX.The cells were infected by CVB3 24 hours later.Antiviral activities of these plasmid were detected by observing cytopathic effect（CPE）,plaque reduction assay.Animal myocarditis model was prepared and plasmid was transfected by Entranster in vivo 2 hours later.Results：In HeLa cells the renduction of viral titer by the plasmid siRNA 2B was 90%.The reductions motality for mice injected intraperitoneally with plasmid-siRNA 2B had been improved by 30%.The pathology of cardioc musle in animal transfected by pasmid siRNA-2B was lighter than that in animal transfected by plasmid siRNA-non.Conclusion：siRNA-2B designed and synthesized in this study has certain antiviral activity,which can inhibit CVB3 infection in HeLa and provides a possibility for further research.