Corneal neuropeptides and herpetic stromal keratitis

描述（由申请方提供）：单纯疱疹病毒-1（HSV-1）的角膜感染导致疱疹性角膜基质炎（HSK），这是全球感染性角膜失明的主要原因。尽管深入的研究和理解HSK的发病机制的实质性进展，这种情况的管理仍然是具有挑战性的。一个重要的障碍是我们对丰富的角膜神经纤维分泌的神经肽在HSK病变发展中的作用了解不足。缺乏这样的知识是一个重要的问题，因为众所周知，神经肽调节炎症和组织修复。本申请的目的是确定什么调节物质P（SP）神经肽水平在角膜后眼部HSV-1感染，以及如何SP与其受体NK 1 R的相互作用控制病毒载量和影响HSK病变的发展。我们将通过使用SP-/-和NK 1 R-/-小鼠在小鼠模型中探讨这些问题。我们最近报道，在没有复制病毒的情况下（临床期）阻断SP-NK 1 R相互作用可显著减少HSK病变的发展。然而，如SP- /-和NK 1 R-/-小鼠中所述，在角膜中活跃病毒复制期间（临床前阶段）缺乏SP-NK 1 R相互作用增强了HSK病变的严重性。我们的初步结果显示，延迟病毒清除和表皮生长因子（EGF），角膜伤口愈合因子，在NK 1 R-/-小鼠的水平降低。根据我们的初步结果，我们假设，SP，在HSV-1感染的角膜中产生的巨噬细胞和角膜神经，促进角膜组织修复和调节的流入，存活和参与病毒清除的先天免疫细胞的功能，因此，在活跃的病毒复制过程中，增强SP介导的作用，应减少严重的HSK病变的发展。提出了三个目标来解决我们的假设。在目的1中，将进行实验以确定角膜巨噬细胞和感觉神经元分别在HSK的临床前和临床期间在HSV-1感染的角膜中调节SP肽水平的作用。在目的2中，将进行实验以确定SP-NK 1 R相互作用是否通过促进HSV-1感染的角膜中树突状细胞（DC）、炎性单核细胞（IM）和自然杀伤（NK）细胞的迁移、存活和功能来调节角膜中的病毒载量。在目标3中，我们将确定是否增强SP介导的作用，在活跃的病毒复制期间，通过局部应用EGF单独，或结合结膜下给药的SP，调节严重的HSK病变的发展。这项研究产生的信息可以帮助开发新的药物策略，通过促进病毒清除和角膜组织修复来减少HSV-1诱导的慢性炎症。

DESCRIPTION (provided by applicant): Corneal infection with herpes simplex virus-1 (HSV-1) causes herpetic stromal keratitis (HSK), a leading cause of infection-induced corneal blindness worldwide. Despite intensive research and substantial progress in understanding the pathogenesis of HSK, the management of this condition continues to be challenging. One significant hurdle is our poor understanding of the role of neuropeptides, secreted by abundant corneal nerve fibers, in the development of HSK lesions. Lack of such knowledge is an important problem because neuropeptides are well known to regulate both inflammation and tissue repair. The objective of this application is to determine what regulates substance P (SP) neuropeptide levels in the cornea after ocular HSV-1 infection, and how SP interactions with its receptor NK1R control the viral load and affects the development of HSK lesions. We will approach these questions in a mouse model by using SP-/- and NK1R-/- mice. We recently reported that blocking SP-NK1R interactions in the absence of replicating virus (clinical period) significantly reduced the development of HSK lesions. However, lack of SP-NK1R interactions during active viral replication in the cornea (pre-clinical period), enhances the severity of HSK lesions, as noted in SP- /- and NK1R-/- mice. Our preliminary results showed delayed viral clearance and reduced levels of epidermal growth factor (EGF), a corneal wound healing factor, in NK1R-/- mice. On the basis of our preliminary results, we hypothesize that SP, produced in HSV-1 infected corneas by macrophages and corneal nerves, promotes corneal tissue repair and regulates the influx, survival, and function of innate immune cells involved in viral clearance therefore, enhancing SP-mediated effects during active viral replication should reduce the development of severe HSK lesions. Three aims are proposed to address our hypothesis. In aim 1, experiments will be carried out to determine the role of corneal macrophages and sensory neurons in regulating the levels of SP peptide in HSV-1 infected corneas during the pre-clinical and clinical periods of HSK, respectively. In aim 2, experiments will be carried out t determine whether SP-NK1R interactions regulate viral load in the cornea by promoting the migration, survival, and functions of dendritic cells (DCs), inflammatory monocytes (IM) and natural killer (NK) cells in HSV-1 infected cornea. In aim 3, we will determine whether enhancing SP-mediated effects during the active viral replication period through topical application of EGF alone, or in combination with subconjunctival administration of SP, modulates the development of severe HSK lesions. The information generated by this study could aid in the development of novel pharmaceutical strategies to reduce HSV-1 induced chronic inflammation by promoting viral clearance and corneal tissue repair.