Herpes Simplex Virus Egress from Cells and Spread into Neuronal Axons

描述（由申请方提供）：1型和2型单纯疱疹病毒（HSV）是常见的人类病毒，在感觉神经节中建立终身潜伏期，并定期重新激活以再次感染粘膜组织。虽然许多HSV感染是相对良性的，但角膜的HSV感染可能具有严重后果。HSV眼部感染触发角膜基质（通常为免疫豁免组织）中的炎性病理，产生称为疱疹基质角膜炎（HSK）的疾病。HSK经常涉及数月或数年的复发性感染，由从神经节到眼睛的再激活和顺行传播周期产生。随着时间的推移，反复感染引起的角膜炎症会产生严重的疤痕和失明。在美国，每年有50，000例新发和复发的HSK病例，HSV仍然是导致失明的主要传染性原因。HSV与其宿主共同进化，使病毒有数百万年的时间研究神经系统。在神经元轴突中，HSV搭便车在运动蛋白上，运动蛋白沿着沿着微管高速公路从神经节中的神经细胞体向上皮中的轴突尖端快速移动。这种快速的轴突运输对于HSV的存活是必不可少的，以允许病毒在面对完全致敏的宿主时产生 免疫力，并传播到其他宿主。两种HSV膜蛋白：gE/gI和US 9参与劫持轴突运输机制。gE/gI和US 9将作为我们的“分子手柄”来研究人们对HSV在神经元轴突中转运的机制知之甚少。目的1研究HSV gE/gI和US 9如何促进病毒结构成分的轴突转运。我们发现，HSV突变体缺乏的gE/gI和US 9完全阻断运输病毒糖蛋白和衣壳进入远端轴突。提出了两种机制来解释如何gE/gI和US 9促进轴突运输。加载机制表明，gE/gI和US 9在神经元细胞体中的功能是将HSV结构蛋白分类并加载到微管马达上。衔接子机制表明，gE/gI和US 9在轴突中的功能是将病毒蛋白拴在驱动蛋白马达上。目标2将涉及努力鉴定gE/gI和US 9中促进装载或适配器功能的排序基序。我们有突变的gE分子，可以让我们区分这两种机制。目的3将通过以下方式研究哪些驱动蛋白马达参与HSV轴突运输：i）对轴突中的荧光细胞货物分子进行成像以确定这些分子是否与HSV蛋白共定位，ii）驱动蛋白的shRNA沉默和iii）使用涉及分裂驱动蛋白的新方法。这些研究将大大推进我们对HSV如何在神经元轴突中导航的理解，并提供重要的新信息，可用于设计更好的药物或疫苗。

DESCRIPTION (provided by applicant): Herpes simplex viruses types 1 and 2 (HSV) are common human viruses that establish lifelong latency in sensory ganglia and reactivate periodically to reinfect mucosal tissues. While many HSV infections are relatively benign, HSV infections of the cornea can have serious consequences. HSV ocular infections trigger inflammatory pathology in the corneal stroma, normally an immunoprivileged tissue, producing a disease known as herpes stromal keratitis (HSK). HSK frequently involves recurring infections, over months or years, produced by cycles of reactivation and anterograde spread from ganglia to the eye. Over time, inflammation in the cornea caused by repeated reinfections can produce significant scarring and blindness. There are ¿ 50,000 new and recurrent cases of HSK every year in the U.S. and HSV remains the leading infectious cause of blindness. HSV coevolved with its host, allowing millions of years in which the virus has studied the nervous system. In neuronal axons, HSV hitchhikes on motor proteins that move rapidly along microtubule highways from nerve cell bodies in ganglia toward axon tips in epithelium. This fast axonal transport is essential for HSV survival, to allow virus production in the face of fully primed host immunity, and spread to other hosts. Two HSV membrane proteins: gE/gI and US9 are involved in hijacking axon transport machinery. gE/gI and US9 will serve us as "molecular handles" to investigate the poorly understood mechanisms by which HSV is transported in neuronal axons. Aim 1 will investigate how HSV gE/gI and US9 promote axonal transport of viral structural components. We showed that an HSV mutant lacking both gE/gI and US9 was completely blocked in transport of viral glycoproteins and capsids into distal axons. Two mechanisms are proposed to explain how gE/gI and US9 promote axonal transport. The Loading mechanism suggests that gE/gI and US9 function in neuronal cell bodies to sort and load HSV structural proteins onto microtubule motors. The Adaptor mechanism suggests that gE/gI and US9 function in axons to tether viral proteins onto kinesin motors. Aim 2 will involve efforts to identfy sorting motifs in gE/gI and US9 that promote either loading or adaptor functions. We have mutant gE molecules that may allow us to distinguish between these two mechanisms. Aim 3 will investigate which kinesin motors are involved in HSV axonal transport by: i) imaging fluorescent cellular cargo molecules in axons to determine if these are colocalized with HSV proteins, ii) shRNA silencing of kinesins and iii) using a new approach involving split kinesins. Together these studies will substantially advance our understanding of how HSV navigates in neuronal axons and provide important new information that can be used to design better drugs or vaccines.