Alleviation of ER stress as a translational strategy to curb ocular viral infections

在美国，疱疹病毒引起的感染性失明是导致视力丧失的主要原因。 一线治疗包括使用核苷类似物，如阿昔洛韦，它可以抑制病毒胸苷 用来限制病毒DNA复制的激酶。然而，出现了耐药性，缺乏坚韧的角膜 生物利用度使开发替代疗法成为当务之急。我们最近发现 以单纯疱疹病毒1型(HSV-1)为代表的疱疹病毒， 在角膜上皮细胞中繁殖。我们已经证明内质网(ER)定位的宿主蛋白 环腺苷3‘，5’-单磷酸(CAMP)反应元件结合蛋白3(CREB3)是 单纯疱疹病毒1型复制。我们的发现改变了目前的理解，即CREB3只是HSV-1的细胞同源物 VP16。我们表明，它是一种重要的促病毒因子，可以被利用来产生新的治疗方法。 抗单纯疱疹病毒感染。我们首次展示了它通过化学伴侣4- 苯丁酸钠(Na-PBA)，可缓解内质网应激，降低CREB3表达，抑制病毒感染 复制。PBA目前被批准用于治疗尿素循环障碍。我们的翻译结果得到以下支持 强有力的小鼠体内数据表明Na-PBA的抗病毒效果和局部剂量安全性。由于高企 与Na-PBA给药相关的钠负荷、不适食性和不能充分渗透 通过局部给药的角膜上皮，我们研制出了各种无钠的PBA。 纳米制剂，以克服与口服和局部注射Na-PBA相关的限制。目的 这个R24应用程序是在两个动物模型中生成临床前数据，这两个动物模型支持IND应用程序 改用PBA治疗眼部HSV感染这将通过3个深思熟虑的、详尽的具体措施来实现 目标。在第一个目标中，我们将评估剂量依赖的药代动力学，以及口服和局部用药的安全性。 提供Na-PBA溶液和各种无钠PBA纳米配方。此外，我们还将 测定Na-PBA和无钠PBA纳米制剂的口服和外用以及口服抗病毒效果 小鼠眼部HSV-1感染模型的建立。第二个目标是使用最有效的口腔和外用药物 S制剂，并在豚鼠和兔模型上进行安全性、PK和有效性的检测 眼部单纯疱疹病毒1型感染。最后目标3，我们将研究Na-PBA和无钠PBA的潜力 与现有抗病毒疗法协同作用的配方，以确定它们作为补充模式的潜力 现有的治疗方法。后者很可能也很重要，因为PBA是一种罕见的通过缓解ER起作用的药物 应激和帮助宿主细胞对病毒感染的反应，从而减少出现的机会 病毒抵抗力。我们已经组建了一个多学科的团队，包括科学家、临床医生、药物 开发和翻译专家，他们可以帮助我们浏览FDA的必要指南。PBA拥有 有可能很快成为现有眼部抗病毒药物的安全有效的替代品。

Infection-associated blindness caused by herpesviruses is a leading cause of vision loss in the United States. Frontline therapies include the use of nucleoside analogs such as acyclovir which inhibit the viral thymidine kinase to restrict viral DNA replication. However, emergence of drug resistance and lack of strong corneal bioavailability have made it an urgent priority to develop alternative therapeutics. We have recently discovered a new mechanism through which herpesviruses, exemplified by herpes simplex virus type-1 (HSV-1), propagate in the corneal epithelium. We have shown that endoplasmic reticulum (ER)-localized host protein cyclic adenosine 3′,5′-monophosphate (cAMP) response element-binding protein 3 (CREB3) is essential to HSV-1 replication. Our findings shift the current understanding that CREB3 is only a cellular homolog of HSV-1 VP16. We showed that it is an important pro-viral factor that can be exploited to generate novel therapeutics against HSV infections. We for the first time showed that its modulation via a chemical chaperone 4- phenylbutyrate sodium (Na-PBA), can alleviate, ER stress, reduce CREB3 expression and inhibit viral replication. PBA is currently approved to treat urea cycle disorder. Our translational results are supported by strong in vivo murine data that suggests antiviral efficacy and topical dosage safety of Na-PBA. Due to the high sodium burden associated with Na-PBA administration, its unpalatability, and inability to penetrate sufficiently through corneal epithelium upon topical administration, we have developed various sodium-free PBA nanoformulations to overcome limitations associated with oral and topical delivery of Na-PBA. The purpose of this R24 application is to generate preclinical data in two animal models that support an IND application for repurposing PBA to treat ocular HSV infection. This will be achieved via 3 well thought, exhaustive specific aims. In the first aim, we will evaluate dose-dependent pharmacokinetics, and safety of orally and topically delivered Na-PBA solution and various sodium-free PBA nanoformulations. Furthermore, we will also determine oral and topical, and oral antiviral efficacy of Na-PBA and sodium-free PBA nanoformulations in murine models of ocular HSV-1 infection. The second aim will use the most effective oral and topical formulation(s) and test their safety, PK, and efficacy in guinea pig and rabbit models of primary and reactivated ocular HSV-1 infection. Finally aim 3, we will investigate the potential of Na-PBA and sodium-free PBA formulations to synergize with existing antiviral therapies to determine their potential as an add-on modality to the existing treatment. The latter is likely and significant since PBA is a rare drug that works via alleviating ER stress and aiding the host cell’s response to viral infection, and thereby reducing the chance for emergence of viral resistance. We have assembled a multidisciplinary team including scientists, clinicians, drug development and translation experts who can help us navigate through requisite FDA guidelines. PBA has the potential to become a safe and efficacious alternative to existing ocular antivirals very quickly.