Mechanisms of Early Growth Response Factor 1 (Egr-1) Induction by HSV-1 Lytic Inf

描述（由申请人提供）：1型单纯疱疹病毒（HSV-1）裂解性感染引起的疾病范围从简单的唇疱疹到危险的角膜炎和致命的脑炎。许多实验室正在广泛研究病毒与宿主细胞之间的相互作用。我们的数据表明，HSV-1可以迅速诱导多功能转录因子早期生长反应-1（Egr-1）的表达在角膜细胞裂解感染。Egr-1作为许多信号级联的汇聚点起作用，并且已知在调节炎症、细胞增殖和凋亡中起重要作用。Western印迹分析显示，Egr-1在Vero和兔角膜细胞系SIRC中不存在，但从感染后24小时（hpi）开始检测到蛋白质，并且与用于感染的病毒的量成正比。用表达EGFP的重组病毒感染，然后通过免疫荧光研究发现，Egr 1仅在感染的细胞内表达。逆转录聚合酶链反应（RT-PCR）分析表明，Egr-1 mRNA的转录早在1 hpi，并不需要从头病毒基因的表达，因为紫外线灭活病毒启动Egr 1转录，但未能产生蛋白质。染色质免疫沉淀（ChIP）试验表明，NFkB和cAMP反应元件结合蛋白（CREB）诱导HSV-1感染，并在感染后招募到Egr-1启动子。总的来说，这些结果表明Egr-1在HSV-1裂解性感染后被有效诱导，并且可能在眼部病毒复制和疾病进展中起关键作用。本研究将通过以下几个方面进一步研究HSV-1感染诱导Egr 1表达的机制，并探讨Egr 1在HSV-1复制中的作用。具体目标1。了解病毒感染如何诱导Egr 1表达。在这个目标中，我们将检查是否需要细胞的病毒结合、病毒基因表达、病毒复制或以上所有来启动Egr 1转录/翻译。具体目标2。确定控制Egr 1转录的机制。在这个目标中，我们将研究调控Egr 1转录的途径。具体目标3。探讨Egr 1对HSV-1基因表达和复制的影响。我们发表的数据表明，Egr 1的过表达与ICP 22内含子结合，抑制ICP 4和ICP 22的转录。在这个目标中，我们将使用DNAzyme通过感染消除Egr 1表达，并检查消除是否会影响HSV-1基因的表达和复制。我们的近期目标是在路易斯安那大学门罗（乌尔姆）建立一个积极的研究计划，这样学生就可以学习病毒学，因为我们的实验室是乌尔姆和路易斯安那州东北部唯一致力于病毒研究的研究计划。长期的使命是确定控制病毒基因表达和复制的调节机制，以开发用于治疗这种毁灭性和严重的病毒性疾病的新的治疗方案。 公共卫生相关性：单纯疱疹病毒-1（HSV-1）原发性和复发性感染可导致角膜瘢痕形成，是美国和发达国家失明的主要原因。我们发现，HSV-1感染迅速诱导角膜细胞中一种重要的多功能蛋白Egr-1的表达。本研究的完成将有助于阐明HSV-1介导Egr 1表达的分子机制，并有助于开发新的策略来预防HSV-1的病毒复制和致盲。

DESCRIPTION (provided by applicant): Herpes simplex virus type-1 (HSV-1) lytic infection causes diseases ranging from simple cold sores to dangerous keratitis and lethal encephalitis. The interaction between virus and host cells is being investigated extensively by many laboratories. Our data demonstrated that HSV-1 can rapidly induce the expression of multi-functional transcriptional factor early growth response-1 (Egr-1) during lytic infection in corneal cells. Egr-1 functions as a convergence point for many signaling cascades and is known to play an important role in regulating inflammation, cell proliferation and apoptosis. Western blot analyses showed that Egr-1 was absent in Vero and rabbit corneal cell line SIRC but the protein was detected starting from 24 hours post infection (hpi) and was directly proportional to the amount of virus used for infection. Infection with recombinant virus expressing EGFP followed by immunofluorescent studies revealed that Egr1 was expressed only within the infected cells. Reverse transcriptase polymerase chain reaction (RT-PCR) analyses indicated that Egr-1 mRNA was transcribed as early as 1 hpi and did not require de novo viral gene expression since UV inactivated virus initiated the Egr1 transcription but failed to produce protein. Chromatin Immunoprecipitation (ChIP) assays demonstrated that NFkB and cAMP response element binding protein (CREB) was induced by HSV-1 infection and recruited to the Egr-1 promoter upon infection. Collectively, these results suggest that Egr-1 is efficiently induced upon HSV-1 lytic infection and may play a key role in the viral replication and the disease progression in eyes. In this project, we will further identify the mechanisms that induced the Egr1 expression by HSV-1 infection and investigate the roles of Egr1 on HSV-1 replication through the following Specific Aims. Specific Aim 1. To understand how viral infection induced Egr1 expression. In this Aim, we will examine if viral binding of the cells, viral gene expression, viral replication, or all of the above were required to initiate Egr1 transcription/translation. Specific Aim 2. To determine the mechanism that controlled the transcription of Egr1. In this Aim, we will investigate the pathways that regulated Egr1 transcription. Specific Aim 3. To evaluate the effect of Egr1 on HSV-1 gene expression and replication. Our published data showed that overexpression of Egr1 bound to ICP22 intron and inhibited transcription of ICP4 and ICP22. In this aim, we will use DNAzyme to eliminate Egr1 expression by infection and check if the elimination can affect HSV-1 gene expression and replication. Our immediate goal is to establish an active research program at the University of Louisiana Monroe (ULM) so the students can study Virology since our laboratory is the only research program at ULM and Northeast Louisiana dedicating to virus research. The long-term mission is to identify the regulatory mechanisms controlling viral gene expression and replication to develop novel therapeutic protocols for treatment of this devastating and severe viral disease. PUBLIC HEALTH RELEVANCE: Herpes Simplex Virus -1 (HSV-1) primary and recurrent infection may result in scarring of the cornea and is the leading cause of blindness in US and the developed world. We showed that HSV-1 infection rapidly induced the expression of an important multifunctional protein Egr-1 in corneal cells. The completion of this proposal will shed light on the molecular mechanism of HSV-1 mediated Egr1 expression and assist to develop new strategy to prevent viral replication and blindness caused by HSV-1.