HSV INDUCED RNA DEGRADATION AND PATHOGENESIS

单纯疱疹病毒(HSV)可导致多种眼部疾病 人类从自限性树突状上皮角膜炎， 结膜炎、睑缘炎到坏死性基质角膜炎。单纯疱疹病毒 角膜炎是美国非外伤性失明的主要原因， 每年约有500,000例确诊病例。此外，单纯疱疹病毒通常 会导致唇疱疹、生殖器溃疡，并且是病毒传播的主要原因。 脑炎。 单纯疱疹病毒和其他嗜神经性疱疹病毒的生命周期 通过周围部位感染的裂解阶段，在此期间所有病毒 基因表达，以及神经元感染的潜伏期，在 其中的基因表达极其有限。在Lytic和Lytic之间的切换 然而，人们对潜伏感染知之甚少。它的一个标志是 嗜神经性疱疹病毒具有关闭大分子的能力 在它们感染的细胞中合成。已显示为1型单纯疱疹病毒(HSV- 1)导致这种关闭的基因是UL41的产物 被称为病毒粒子宿主关闭蛋白或VHS的基因。它的结构和 尽管最近的研究表明，VHS的功能尚不清楚 单纯疱疹病毒2型、水痘-带状疱疹病毒、猪伪狂犬病VHS的同源物 病毒和马疱疹病毒，这表明VHS可能是必要的 嗜神经性生命周期。 以HSV-1作为模式系统，这项建议的目标是 探讨VHS蛋白的作用机制和功能 体内和体外宿主大分子合成的关闭。对这件事 将引入结尾、无意义、缺失和替换突变 进入VHS的开放阅读框架。这些突变对人类健康的影响 然后，蛋白质降解宿主和病毒mRNAs的能力将被 通过体外表达/降解试验和体内跟踪检测 将这些突变引入病毒基因组的背景中。 由此产生的突变体也将接受测试，以确定它们是否有能力建立、 维持并重新激活神经元中的病毒潜伏期。努力还将 被要求评估负责细胞特异性mRNA的结构域 并将这种活性与发病机制联系起来。更好的 了解VHS蛋白的功能结构域及其在体内的作用 急性和潜伏感染单纯疱疹病毒基因表达的调节 细胞将进一步深入了解单纯疱疹病毒 在其宿主的一生中持续存在。

Herpes simplex virus (HSV) can cause a variety of ocular diseases in humans ranging from self-limiting dendritic epithelial keratitis, conjunctivitis, and blepharitis to necrotizing stromal keratitis. HSV keratitis is a leading cause of non-traumatic blindness in the US, with approximately 500,000 cases diagnosed each year. In addition, HSV commonly causes cold sores, genital sores, and is a leading cause of viral encephalitis. The lifecyles of HSV and other neurotropic herpesviruses are characterized by a lytic phase of infection at peripheral sites during which all virus genes are expressed, and a latent phase of infection in neurons, during which gene expression is extremely limited. The switch between lytic and latent infection, however, is poorly understood. One hallmark of the neurotropic herpesviruses is their ability to shut off macromolecular synthesis in the cells they infect. It has been shown for HSV type 1 (HSV- 1) that the gene responsible for this shut off is the product of the UL41 gene known as the virion host shutoff protein or vhs. The structure and function of vhs is not understood although recent work has demonstrated homologs of vhs in HSV-2, varicella zoster virus, swine pseudorabies virus, and equine herpesvirus, suggesting that vhs may be necessary for a neurotropic lifecycle. Using HSV-1 as a model system, the objectives of this proposal are to investigate the mechanisms of action and functions of the vhs protein in the shutoff of host macromolecular synthesis in vitro and in vivo. To this end, nonsense, deletion, and substitution mutations will be introduced into the open reading frame of vhs. The effects of these mutations upon the ability of the protein to degrade host and viral mRNAs will then be measured by in vitro expression/degradation assays and in vivo following introduction of these mutations into the context of the viral genome. Resulting mutants will also be tested for their ability to establish, maintain, and reactivate from viral latency in neurons. Efforts will also be made to assess domains which are responsible for cell-specific mRNA degradation and to correlate this activity with pathogenesis. A better understanding of the functional domains of the vhs protein and its role in the regulation of HSV gene expression in acutely and latently infected cells will allow further insight into the mechanism by which HSV can persist for the lifetime of its host.