Identification of RNase L-dependent, 3'-end-modified, viral small RNAs in Sindbis virus-infected mammalian cells.
Identification of RNase L-dependent, 3'-end-modified, viral small RNAs in Sindbis virus-infected mammalian cells.
复制标题
DOI：
10.1128/mbio.00698-13
复制
发表时间：
2013-11-19
期刊：
影响因子：
6.4
通讯作者：
Pfeffer S
中科院分区：
文献类型：
--
作者：
Girardi E;Chane-Woon-Ming B;Messmer M;Kaukinen P;Pfeffer S
小RNA在宿主-病原体相互作用中起关键作用。事实上，小RNA介导的沉默或RNA干扰（RNAi）是抗病毒免疫的最早形式之一。尽管它代表了许多生物体中对抗病毒的主要防御系统，但RNA干扰的抗病毒作用尚未在高等脊椎动物中得到明确证实。然而，众所周知，它们对病毒感染的反应依赖于宿主模式识别受体（PRR）对病毒RNA的识别，以触发干扰素途径的激活。在目前的工作中，我们报告存在一种新的小的非编码RNA群体产生的哺乳动物细胞后，RNA病毒感染。使用辛德毕斯病毒（SINV）作为原型虫媒病毒模型，我们分析了人类和非洲绿色猴细胞系中感染细胞的小RNA群体。在这里，我们提供的证据表明，存在离散的小RNA的病毒来源，不与RNA诱导的沉默复合物（RISC），这是高度表达和检测的北方印迹分析，并积累为21- 28个核苷酸（nt）的物种在感染过程中。我们报告说，细胞的抗病毒核糖核酸内切酶RNase L切割病毒基因组，反过来产生小RNA。令人惊讶的是，我们发现在SINV衍生的病毒小RNA（SvsRNA）的3′端核苷酸上存在修饰，这可能是其稳定性的起源。总之，我们的研究结果表明，稳定的修饰的小病毒RNA可能代表一种新的方式来调节宿主病毒感染后的相互作用。在持续的军备竞赛中，病毒必须应对宿主的抗病毒反应，才能成功地建立感染。在哺乳动物细胞中，宿主防御机制依赖于病毒RNA的识别，导致I型干扰素（IFN）的激活。反过来，许多干扰素刺激基因（ISG）的表达被诱导以抑制病毒复制。在这里，我们报告说，细胞质，干扰素诱导的，细胞内核糖核酸内切酶RNase L参与积累的一种新的小RNA人口的病毒来源。这些小RNA在SINV感染哺乳动物细胞后产生，并通过3′端修饰稳定。总之，我们的研究结果表明，在我们的系统中，RNA沉默对辛德毕斯病毒（SINV）没有活性，并可能为更好地理解一类新型小RNA介导的抗病毒反应开辟道路。
Small RNAs play a critical role in host-pathogen interaction. Indeed, small RNA-mediated silencing or RNA interference (RNAi) is one of the earliest forms of antiviral immunity. Although it represents the main defense system against viruses in many organisms, the antiviral role of RNAi has not been clearly proven in higher vertebrates. However, it is well established that their response to viral infection relies on the recognition of viral RNAs by host pattern recognition receptors (PRRs) to trigger activation of the interferon pathway. In the present work, we report the existence of a novel small noncoding RNA population produced in mammalian cells upon RNA virus infection. Using Sindbis virus (SINV) as a prototypic arbovirus model, we profiled the small RNA population of infected cells in both human and African green monkey cell lines. Here, we provide evidence for the presence of discrete small RNAs of viral origin that are not associated with the RNA-induced silencing complex (RISC), that are highly expressed and detected by Northern blot analysis, and that accumulate as 21- to 28-nucleotide (nt) species during infection. We report that the cellular antiviral endoribonuclease RNase L cleaves the viral genome, producing in turn the small RNAs. Surprisingly, we uncovered the presence of a modification on the 3′-end nucleotide of SINV-derived viral small RNAs (SvsRNAs) that might be at the origin of their stability. Altogether, our findings show that stable modified small viral RNAs could represent a novel way to modulate host-virus interaction upon SINV infection. In a continuous arms race, viruses have to deal with host antiviral responses in order to successfully establish an infection. In mammalian cells, the host defense mechanism relies on the recognition of viral RNAs, resulting in the activation of type I interferons (IFNs). In turn, the expression of many interferon-stimulated genes (ISGs) is induced to inhibit viral replication. Here we report that the cytoplasmic, interferon-induced, cellular endoribonuclease RNase L is involved in the accumulation of a novel small RNA population of viral origin. These small RNAs are produced upon SINV infection of mammalian cells and are stabilized by a 3′-end modification. Altogether, our findings indicate that in our system RNA silencing is not active against Sindbis virus (SINV) and might open the way to a better understanding of the antiviral response mediated by a novel class of small RNAs.