Virion Sialic Acid and HSV Ocular Infection

描述（由申请人提供）：单纯疱疹病毒是美国因传染病导致失明的主要原因。目前有几种抗病毒药物被批准用于治疗HSV角膜炎，但它们的使用存在问题，一些感染难以治疗。这些抗病毒药物也不能消除潜伏性感染，复发性感染导致大多数致盲性角膜炎。作用于病毒体本身以防止附着或进入细胞的策略是尚未充分研究的可行策略。我们先前描述了几种肽，其在低微摩尔浓度下通过灭活溶液中的病毒体、抑制进入并在用肽预处理的细胞中诱导抗性状态来抑制HSV感染。这些肽在眼睛中也几乎没有毒性。最近，我们描述了一种抑制HSV-1感染的肽TAT-C，初步数据表明TAT-C与病毒包膜蛋白上的唾液酸结合。最近发表的第二个关键发现是，一种或多种HSV-1进入蛋白上的唾液酸是有效进入细胞所必需的。这些发现使我们提出了一个总体假设，即TAT-C通过与一种或多种进入蛋白上的唾液酸结合来抑制HSV融合，并且这种结合干扰了进入过程中唾液酸介导的步骤。本提案中的实验旨在检验这一假设，并将通过四个具体目标来完成。1)检验TAT-C和唾液酸参与融合前进入步骤的假设。2)检验TAT-C或从gB、gD和/或gH/gL中去除唾液酸改变蛋白质功能的假设。3)检验TAT-C或唾液酸去除改变gB、gD和/或gH/gL的结构或稳定性的假设。4)检验唾液酸对体内感染至关重要以及TAT-C具有体内疗效和对潜伏期的影响的假设。这些研究将增加我们对病毒粒子唾液酸在HSV-1感染中的作用的理解，并可能导致新的抗病毒治疗策略的发展。公共卫生相关性：我们描述的研究，将确定如何唾液酸对HSV-1包膜糖蛋白影响眼部疾病和他们在病毒进入发挥的作用。我们还将测试结合唾液酸的肽阻断HSV-1感染的机制。这些研究将为HSV-1进入提供新的见解，并可能导致新型抗病毒药物的开发。

DESCRIPTION (provided by applicant): Herpes simplex virus is the leading cause of blindness due to infectious disease in the United States. Several antivirals are currently approved for treating HSV keratitis but there are problems with their use and some infections are refractory to treatment. These antivirals also cannot eliminate latent infection and recrudescent infections cause the majority of the blinding keratitis. Strategies that act on virions themselves to prevent attachment or entry into cells are viable strategies that have not been adequately studied. We previously described several peptides that inhibit HSV infection at low micromolar concentrations by inactivating virions in solution, inhibiting entry, and inducing a state of resistance in cells pre-treated with the peptides. These peptides also show little if any toxicity in the eye. Recently, we described a peptide, TAT-C, that inhibits HSV-1 infection and preliminary data suggests TAT-C binds to sialic acids on viral envelope proteins. A second critical finding recently published, is that sialic acids on one or more HSV-1 entry proteins are required for efficient entry into cells. These findings lead us to propose the overall hypothesis that TAT-C inhibits HSV fusion by binding to sialic acids on one or more entry proteins and that this binding interferes with a sialic acid mediated step in the entry process. The experiments in this proposal are designed to test this hypothesis and will be accomplished through four specific aims. 1) Test the hypothesis that TAT-C and sialic acids are involved in an entry step prior to fusion. 2) Test the hypothesis that TAT-C or removal of sialic acids from gB, gD, and/or gH/gL alters the function of the proteins. 3) Test the hypothesis that TAT-C or sialic acid removal alters the structure or stability of gB, gD, and/or gH/gL. 4) Test the hypothesis that sialic acids are critical for in vivo infection and that TAT-C has in vivo efficacy and the effect on latency. These studies will increase our understanding of the role of virion sialic acids in HSV-1 infection and could lead to the development of novel antiviral strategies for therapy. PUBLIC HEALTH RELEVANCE: We describe studies that will determine how sialic acids on HSV-1 envelope glycoproteins affect ocular disease and the role they play in viral entry. We will also test the mechanism whereby a peptide that binds sialic acid blocks HSV-1 infection. The studies will provide new insights into HSV-1 entry and could lead to the development of novel antivirals.