Mechanism of VEE Attenuation

VEE衰减机制

• 批准号: 6511384
• 负责人: LAURA J WHITE
• 金额: $ 4.81万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6511384
• 关键词: Venezuelan equine encephalitis virus; attenuated microorganism; gene mutation; host organism interaction; interferons; laboratory mouse; virulence; virus genetics

DESCRIPTION: (Adapted from the Investigator's abstract): Venezuelan equine encephalitis virus (VEE) is an important equine and human pathogen. It periodically emerges in epidemics caused by highly virulent epizootic strains. Virulence determinants of the natural VEE strains are not well understood at the molecular level. In vaccine strains and laboratory attenuated strains, virulence determinants for mice have been mapped to El and E2 glycoproteins and the 5' untranslated region (utr). A single change at nucleotide 3 (nt3) of the 5' utr of the VEE genome (G to A substitution) introduced into a molecular clone of wild-type virulent VEE results in a virus that is completely attenuated in mice. The long-term goal is to determine the mechanisms by which specific mutations in the 5' utr of the VEE genome attenuates the virus, and to use the VEE system to elucidate the role of lFNAB in alphaviruses pathogenesis. We hypothesize that the nt3A mutation results in a virus with increased sensitivity to the antiviral actions of lFNaB due to increased levels of viral dsRNA replication intermediates, consequently (a) increasing induction of IFN-stimulated antiviral genes, (b) enhancing activation of IFN-induced antiviral proteins that require dsRNA as cofactor, or alternatively, (C) the nt3A mutant virus may be slower in inhibiting host protein synthesis, allowing continued synthesis of key antiviral activities. We will test these hypotheses in the context of the following specific questions: 1) What is the relative contribution of INFaB-induced antiviral pathways PKR and 2'-5' OAS/RNase L in the inhibition of replication of wild type compared to nt3A mutant VEE in vitro and in vivo? 2) Does the nt3A mutation affect the induction and/or the activation of downstream IFNaB effector mechanisms such as PKR, 2'-5' OAS, RNase L, and ADAR? and 3) What is the effectof the nt3A mutation on virus-induced host protein synthesis inhibition?

描述：（改编自调查员的摘要）：委内瑞拉马 脑炎病毒（VEE）是重要的马和人类病原体。它 周期性地出现在由高毒性的epizootic菌株引起的流行病中。 天然VEE菌株的毒力决定因素在 分子水平。在疫苗菌株和实验室衰减中， 小鼠的毒力决定因素已映射到EL和E2糖蛋白，以及 5'未翻译区域（UTR）。在核苷酸3（NT3）的单个变化 VEE基因组的5'UTR（g to替代）引入了分子 野生型毒物的克隆导致病毒完全 在小鼠中衰减。长期目标是确定该机制 VEE基因组5'UTR中的特异性突变会衰减病毒，并减轻 使用VEE系统阐明LFNAB在α病毒发病机理中的作用。 我们假设NT3A突变导致病毒随着增加而增加 由于病毒水平升高，对LFNAB的抗病毒作用的敏感性 dsRNA复制中间体，因此（a）增加诱导 IFN刺激的抗病毒基因，（b）增强IFN诱导的激活 需要dsRNA作为辅因子的抗病毒蛋白，或者（c） NT3A突变病毒在抑制宿主蛋白合成方面可能较慢，允许 继续合成关键抗病毒活性。我们将检验这些假设 在以下特定问题的背景下：1）相对是什么 Infab诱导的抗病毒途径PKR和2'-5'OAS/RNASE L的贡献 与NT3A突变体的体外相比，野生型复制的抑制作用 和体内？ 2）NT3A突变会影响诱导和/或 激活下游IFNAB效应器机制，例如PKR，2'-5'OAS， rnase l和adar？ 3）NT3A突变对 病毒诱导的宿主蛋白质合成抑制？