埃博拉病毒和甲型流感病毒在microRNA水平上与宿主相互作用的研究
发布时间：2018-09-19 13:14
【摘要】：RNA病毒种类繁多,比较常见的RNA病毒有埃博拉病毒、甲型流感病毒、中东呼吸综合症冠状病毒以及登革病毒等。近几年来这些RNA病毒的爆发和流行对人类健康已经构成严重的威胁,尤其是最近西非爆发的埃博拉病毒致死率已经达到40%。在RNA病毒感染过程中病毒和宿主都会通过编码一些小分子来调节对方,其中包括microRNA分子。MicroRNA作为一类小片段的RNA分子具有重要的调节作用,通常一个microRNA可以同时调节上百个基因的表达,这种高效的调节方式常常被病毒加以利用并辅助其感染。虽然已知很多microRNA都能够参与病毒感染的过程,但是对其发挥作用的具体机制仍然不是十分清楚。为了研究RNA病毒感染过程中microRNA发挥的作用,分别对埃博拉病毒和甲型流感病毒进行分析研究。在埃博拉病毒中,利用生物信息学的方法对埃博拉病毒基因组序列进行分析,发现在病毒基因组中含有一段潜在的microRNA编码序列。进一步利用埃博拉病毒感染者血清的RNA-Seq数据对预测的序列进行验证并结合体外实验验证结果,发现该预测的序列能够编码出两条成熟的microRNA分子并分别命名为Zebov-miR-1-5p和Zebov-miR-1-3p。其中Zebov-miR-1-5p的序列与人内源性has-miR-155-5p的序列具有相似性,而且能够有效抑制宿主细胞中KPNA1基因的表达。KPNA1作为入核辅助因子能够调节STAT1的信号传递功能,埃博拉病毒通过此途径抑制干扰素信号释放并最终逃逸宿主细胞对病毒感染的免疫监视。与埃博拉病毒不同,在甲型流感病毒感染中,病毒并不能编码任何microRNA分子,但是被感染的宿主细胞中,部分microRNA的表达会随着病毒复制的增加而逐渐降低。通过荧光素酶报告实验表明,表达降低的microRNA中,miR-23a能够靶向于流感病毒基因组的PA、PB1以及PB2中的部分序列。流感病毒聚合酶相关基因的表达下降能够抑制病毒在宿主体内的复制速度。利用miR-23a的这个特性在流感病毒感染的小鼠中注射miR-23a可以用于改善流感病毒对小鼠的感染程度。结合以上两种RNA病毒与microRNA之间的调控关系,分析认为不同的RNA病毒在其感染过程中具有不同的调节方式。其中既有通过主动编码microRNA逃逸宿主的免疫监视,也有利用宿主表达的microRNA调节自身复制速度以延长感染时间。因此RNA病毒在利用microRNA的方式上存在不同的策略,通过不同的策略在宿主与病毒感染过程中达到一个平衡并有利于病毒的扩增和传播。当对RNA病毒的这些调节方式深入研究后,我们就可以利用病毒感染中的这些特点有针对性地设计出药物以干扰病毒的感染过程。
[Abstract]:RNA viruses include Ebola virus, influenza A virus, Middle East Respiratory Syndrome coronavirus and dengue virus. The outbreaks and epidemics of these RNA viruses have posed a serious threat to human health in recent years, especially since the recent outbreak of Ebola in West Africa has led to a mortality rate of 40 per cent. In the process of RNA infection, both the virus and the host regulate each other by encoding small molecules, including microRNA molecules. MicroRNAs play an important role as a class of small fragments of RNA molecules. Usually, a single microRNA regulates the expression of hundreds of genes at the same time. Although many microRNA are known to be involved in the process of viral infection, the mechanism of its role is still unclear. In order to study the role of microRNA in the process of RNA infection, Ebola virus and influenza A virus were analyzed. In Ebola virus, the genome sequence of Ebola virus was analyzed by bioinformatics, and a potential microRNA coding sequence was found in the genome of Ebola virus. The predicted sequence was further verified by RNA-Seq data from the sera of Ebola virus infected patients and combined with the results of in vitro experiments. It was found that the predicted sequence could encode two mature microRNA molecules named Zebov-miR-1-5p and Zebov-miR-1-3p., respectively. The sequence of Zebov-miR-1-5p is similar to that of human endogenous has-miR-155-5p, and it can effectively inhibit the expression of KPNA1 gene in host cells. KPNA1 can regulate the signal transduction function of STAT1 as an auxiliary factor. In this way, Ebola virus inhibits the release of interferon signals and eventually escapes host cells from immune surveillance of virus infection. Unlike the Ebola virus, the virus does not encode any microRNA molecules in influenza A infection, but the expression of microRNA in infected host cells decreases with the increase of viral replication. The results of luciferase report showed that the down-expressed microRNA could target the PA,PB1 of influenza virus genome and some sequences of PB2. Decreased expression of influenza virus polymerase-related genes can inhibit the replication of the virus in the host. The use of this characteristic of miR-23a can be used to improve the degree of influenza virus infection in mice by injecting miR-23a into mice infected with influenza virus. According to the regulatory relationship between the two RNA viruses and microRNA, it is concluded that different RNA viruses have different regulation modes in the process of infection. Both immune surveillance of host by active coding of microRNA and microRNA expressed by host adjusts the rate of self-replication to prolong infection time. Therefore, RNA virus has different strategies in the way of using microRNA, through different strategies in the host and virus infection process to achieve a balance and conducive to the expansion and transmission of the virus. When the regulation of RNA virus is deeply studied, we can use these characteristics of virus infection to design drugs to interfere with the infection process of the virus.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R373
，
本文编号：2250230
[Abstract]:RNA viruses include Ebola virus, influenza A virus, Middle East Respiratory Syndrome coronavirus and dengue virus. The outbreaks and epidemics of these RNA viruses have posed a serious threat to human health in recent years, especially since the recent outbreak of Ebola in West Africa has led to a mortality rate of 40 per cent. In the process of RNA infection, both the virus and the host regulate each other by encoding small molecules, including microRNA molecules. MicroRNAs play an important role as a class of small fragments of RNA molecules. Usually, a single microRNA regulates the expression of hundreds of genes at the same time. Although many microRNA are known to be involved in the process of viral infection, the mechanism of its role is still unclear. In order to study the role of microRNA in the process of RNA infection, Ebola virus and influenza A virus were analyzed. In Ebola virus, the genome sequence of Ebola virus was analyzed by bioinformatics, and a potential microRNA coding sequence was found in the genome of Ebola virus. The predicted sequence was further verified by RNA-Seq data from the sera of Ebola virus infected patients and combined with the results of in vitro experiments. It was found that the predicted sequence could encode two mature microRNA molecules named Zebov-miR-1-5p and Zebov-miR-1-3p., respectively. The sequence of Zebov-miR-1-5p is similar to that of human endogenous has-miR-155-5p, and it can effectively inhibit the expression of KPNA1 gene in host cells. KPNA1 can regulate the signal transduction function of STAT1 as an auxiliary factor. In this way, Ebola virus inhibits the release of interferon signals and eventually escapes host cells from immune surveillance of virus infection. Unlike the Ebola virus, the virus does not encode any microRNA molecules in influenza A infection, but the expression of microRNA in infected host cells decreases with the increase of viral replication. The results of luciferase report showed that the down-expressed microRNA could target the PA,PB1 of influenza virus genome and some sequences of PB2. Decreased expression of influenza virus polymerase-related genes can inhibit the replication of the virus in the host. The use of this characteristic of miR-23a can be used to improve the degree of influenza virus infection in mice by injecting miR-23a into mice infected with influenza virus. According to the regulatory relationship between the two RNA viruses and microRNA, it is concluded that different RNA viruses have different regulation modes in the process of infection. Both immune surveillance of host by active coding of microRNA and microRNA expressed by host adjusts the rate of self-replication to prolong infection time. Therefore, RNA virus has different strategies in the way of using microRNA, through different strategies in the host and virus infection process to achieve a balance and conducive to the expansion and transmission of the virus. When the regulation of RNA virus is deeply studied, we can use these characteristics of virus infection to design drugs to interfere with the infection process of the virus.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R373
，
本文编号：2250230
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