Specific phenotypic restoration of an attenuated virus by knockout of a host resistance gene
Specific phenotypic restoration of an attenuated virus by knockout of a host resistance gene
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DOI：
10.1073/pnas.100415697
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发表时间：
2000-05-23
影响因子：
11.1
通讯作者：
Virgin, HW
中科院分区：
文献类型：
--
作者：
Leib, DA;Machalek, MA;Virgin, HW
为了制造疾病，病毒必须进入宿主，在宿主组织中局部繁殖，从进入部位传播，并克服或逃避宿主免疫反应。在这一感染过程的每个阶段，特定的微生物和宿主基因决定了病毒的最终毒力。遗传学方法已经确定了许多病毒基因，这些基因在毒力中发挥关键作用，并被推定为针对宿主固有和获得性免疫反应的特定成分。然而，还没有正式的证据表明毒力基因在体内针对宿主途径中的特定蛋白质。基于细胞培养研究，已提出单纯疱疹病毒1型基因ICP34.5(感染细胞蛋白)通过否定干扰素诱导的双链RNA依赖的蛋白激酶R或PKR的抗病毒功能而增强神经毒力[Chou，J，，Chen，J，J，Gross，M.&Roizman，B.(1995)过程。纳特尔，阿卡德。SCI，USA 92,10516-10520]，在此，我们证明了通过缺失ICP34.5而减毒的病毒在PKR基因缺失的宿主中表现出野生型复制和毒力。我们发现，通过使用额外的宿主和病毒突变体，毒力的恢复是针对ICP34.5和PKR的。利用重组病毒感染宿主防御基因零突变的动物，为鉴定微生物毒力基因的体内机制和靶点提供了一种正式的遗传测试方法。
To produce disease, viruses must enter the host, multiply locally in host tissues, spread from the site of entry, and overcome or evade host immune responses. At each stage in this infectious process, specific microbial and host genes determine the ultimate virulence of the virus. Genetic approaches have identified many viral genes that play critical roles in virulence and are presumed to target specific components of the host innate and acquired immune response. However, formal proof that a virulence gene targets a specific protein in a host pathway in vivo has not been obtained. Based on cell culture studies, it has been proposed that the herpes simplex virus type 1 gene ICP34.5 (ICP, infected cell protein) enhances neurovirulence by negating antiviral functions of the IFN-inducible double-stranded RNA-dependent protein kinase R or PKR [Chou, J,, Chen, J,J,, Gross, M. & Roizman, B. (1995) Proc. Natl, Acad. Sci, USA 92, 10516-10520], Herein, we show that a virus that has been attenuated by deletion of ICP34.5 exhibits wild-type replication and virulence in a host from which the PKR gene has been deleted. We show that restoration of virulence is specific to ICP34.5 and PKR by using additional host and viral mutants. The use of recombinant viruses to infect animals with null mutations in host defense genes provides a formal genetic test for identifying in vivo mechanisms and targets of microbial virulence genes.