The Ebola virus VP35 protein functions as a type IIFN antagonist
The Ebola virus VP35 protein functions as a type IIFN antagonist
复制标题
DOI：
10.1073/pnas.220398297
复制
发表时间：
2000-10-24
影响因子：
11.1
通讯作者：
Palese, P
中科院分区：
文献类型：
--
作者：
Basler, CF;Wang, XY;Palese, P
已经开发了一种测定法，其允许鉴定起I型IFN拮抗剂作用的分子。使用这种检测方法，我们已经确定了埃博拉病毒编码的I型IFN反应抑制剂，埃博拉病毒VP 35蛋白。该测定依赖于流感病毒突变体，流感delNS 1病毒的特性，其缺乏NS 1 ORF，因此不产生NS 1蛋白。当细胞被流感delNS 1病毒感染时，会产生大量的I型IFN。因此，流感delNSl病毒复制较差。然而，编码干扰I型IFN诱导的抗病毒功能的蛋白质（例如甲型流感病毒NS 1蛋白或单纯疱疹病毒蛋白ICP 34.5）的质粒的高效瞬时转染挽救了流感delNS 1病毒的生长。当表达单个埃博拉病毒蛋白的质粒转染到Madin达比犬肾细胞中时，埃博拉病毒VP 35蛋白增强流感delNS 1病毒生长超过100倍。VP 35随后显示阻断双链RNA和病毒介导的IFN刺激的应答元件报告基因的诱导，并阻断双链RNA和病毒介导的IFN-P启动子的诱导。因此，埃博拉病毒VP 35可能抑制埃博拉病毒感染细胞中I型IFN的诱导，并且可能是体内埃博拉病毒毒力的重要决定因素。
An assay has been developed that allows the identification of molecules that function as type I IFN antagonists. Using this assay, we have identified an Ebola virus-encoded inhibitor of the type I IFN response, the Ebola virus VP35 protein. The assay relies on the properties of an influenza virus mutant, influenza delNS1 virus, which lacks the NS1 ORF and, therefore, does not produce the NS1 protein. When cells are infected with influenza delNS1 virus, large amounts of type I IFN are produced. As a consequence, influenza delNS1 virus replicates poorly. However, high-efficiency transient transfection of a plasmid encoding a protein that interferes with type I IFN-induced antiviral functions, such as the influenza A virus NS1 protein or the herpes simplex virus protein ICP34.5, rescues growth of influenza delNS1 virus. When plasmids expressing individual Ebola virus proteins were transfected into Madin Darby canine kidney cells, the Ebola virus VP35 protein enhanced influenza delNS1 virus growth more than 100-fold. VP35 subsequently was shown to block double-stranded RNA- and virus-mediated induction of an IFN-stimulated response element reporter gene and to block double-stranded RNA- and virus-mediated induction of the IFN-P promoter. The Ebola virus VP35 therefore is likely to inhibit induction of type I IFN in Ebola virus-infected cells and may be an important determinant of Ebola virus virulence in vivo.