中文摘要：

目的 研究RNA编辑酶腺苷酸脱氨酶（adenosine deaminase acting on RNA,ADAR1）对新型肠道病毒71型（enterovirus 71,EV71）感染及变异的影响。方法 运用RNAi技术筛选ADAR1基因沉默稳定细胞株,通过MTT分析病毒感染后细胞活力变化、噬斑形成分析病毒滴度及细胞对病毒的敏感性,以及Western blot测定病毒蛋白表达水平等,分析ADAR1对EV71感染的影响。由于ADAR1介导的RNA编辑可使基因形成A-G或T-C突变,为确定ADAR1影响EV71感染是否与其编辑EV71基因组导致病毒变异有关,对EV71流行区EV71的突变特征进行分析;并利用EV71感染ADAR1基因沉默细胞,通过对病毒基因组测序分析,研究ADAR1是否直接编辑EV71基因组。结果 ADAR1基因沉默后,与对照细胞相比,病毒感染细胞的存活率下降更快,并形成更多、更大的噬斑。病毒感染细胞中的VP1蛋白和细胞培养基上清中的病毒滴度均明显增加。EV71突变特征分析表明,虽然A-G和T-C之间的变异是病毒突变的主要类型,但EV71感染实验初步证明,ADAR1并不直接编辑EV71病毒基因组。结论 ADAR1可能具有抗EV71感染的作用,但ADAR1可能并不直接编辑EV71基因组。

英文摘要：

Objective To identify the role of RNA-editing enzyme ADAR1 （adenosine deaminase acting on RNA） in EV71 infection and virus mutation. Methods RNAi technology was applied to establish ADAR1 knock-down stable cell lines. Then the cells were served to evaluate the role of ADAR1 in EV71 infection by MTT assay for detecting virus-induced cell viability, virus plaque assay for quantification of the virus titer and the cellular susceptibility to the virus, and Western blot for virus protein expressions. ADAR1-mediated RNA editing can result in the genetic A-G and T-C mutations. To further determine whether the effects of ADAR1 on EV71 infection were correlated with ADAR1- mediated EV71 RNA editing and therefore increased the viral mutations during the infection, the characteristics of EV71 mutation were analyzed based on the different full-length viral genomesfrom epidemic regions. The viral genome was also sequenced from the infected ADAR1 knock-down cells. Results After ADAR1 knock-down, the cell viability decreased quickly after the virus infection,and formed much more and larger sizes of plaques than the control cells. The virus capsid protein VP1 expressions and virus titer in the ceils culture media were both increased in ADAR1 knock- down cells. Statistic analysis showed that A-G and T-C mutations were the major mutations of EV71, which were believed to be the hot sites for RNA-editing. However, the results of viral RNA genomic sequencing data indicated that ADAR1 did not edit EV71 genome directly. Conclusions ADAR1 was a restriction factor for controlling EV71. However,ADAR1 does not directly edit EV71 genome.