HSV INDUCED RNA DEGRADATION AND PATHOGENESIS

单纯疱疹病毒（HSV）可引起多种眼部疾病， 人类从自限性树突状上皮角膜炎， 结膜炎和睑缘炎到坏死性角膜基质炎。HSV 角膜炎是美国非创伤性失明的主要原因， 每年确诊约50万例。此外，HSV通常 导致唇疱疹，生殖器溃疡，是病毒性疾病的主要原因， 脑炎 HSV和其他嗜神经性疱疹病毒的生命周期特征如下： 通过在外周部位感染的裂解期，在此期间，所有病毒 基因的表达，以及神经元感染的潜伏期， 这种基因的表达非常有限。裂解和 然而，人们对潜伏感染知之甚少。 一个标志的 嗜神经性疱疹病毒是它们关闭大分子 在它们感染的细胞中合成。已显示对于HSV 1型（HSV-1）， 1)负责这种关闭的基因是UL 41的产物， 这种基因被称为病毒体宿主关闭蛋白或VHS。结构和 尽管最近的研究表明， HSV-2、水痘带状疱疹病毒、猪伪狂犬病中vhs同源物 病毒和马疱疹病毒，这表明VHS可能是必要的， 亲神经性生命周期 使用HSV-1作为模型系统，本提案的目标是 研究vhs蛋白的作用机制和功能 在体内外阻断宿主大分子的合成。本 将引入末端、无义、缺失和取代突变 进入VHS的开放阅读框架。这些突变对 蛋白质降解宿主和病毒mRNA的能力将被 通过体外表达/降解测定和体内以下测定来测量 将这些突变引入病毒基因组的背景中。 还将测试所得突变体的建立， 维持并重新激活神经元中的病毒潜伏期。 还将努力 评估负责细胞特异性mRNA的结构域 降解，并将这种活性与发病机制相关联。更好的 了解vhs蛋白的功能结构域及其在 急性和潜伏感染HSV基因表达调控 细胞将允许进一步深入了解HSV可以 在宿主的生命周期中持续存在。

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.