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

在美国，疱疹病毒引起的失明是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，其抑制病毒胸苷 激酶来限制病毒DNA复制。但耐药性的出现和角膜缺乏坚强的 生物利用度使得开发替代疗法成为当务之急。我们最近发现 一种新的机制，通过该机制，疱疹病毒，例如单纯疱疹病毒1型（HSV-1）， 在角膜上皮中繁殖。我们已经证明，内质网（ER）定位的宿主蛋白， 环腺苷酸（cAMP）反应元件结合蛋白3（CREB 3）是必不可少的， HSV-1复制。我们的发现改变了目前的认识，即CREB 3只是HSV-1的细胞同源物 VP16。我们发现，它是一个重要的前病毒因子，可用于产生新的治疗方法 抗HSV感染。我们第一次证明了它通过化学伴侣4- 苯丁酸钠（Na-PBA）可减轻ER应激，降低CREB 3表达，抑制病毒 复制的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： 强有力的体内鼠数据表明Na-PBA的抗病毒功效和局部剂量安全性。由于高 与Na-PBA给药相关的钠负荷、其不适口性和不能充分渗透 通过角膜上皮局部给药，我们已经开发了各种无钠PBA 纳米制剂，以克服与口服和局部递送Na-PBA相关的限制。的目的 该R24申请旨在生成两种动物模型的临床前数据，以支持IND申请， 将PBA重新用于治疗眼部HSV感染。这将通过3个深思熟虑，详尽的具体 目标。在第一个目标中，我们将评估口服和局部给药的剂量依赖性药代动力学和安全性。 提供Na-PBA溶液和各种无钠PBA纳米制剂。此外，我们还将 确定Na-PBA和无钠PBA纳米制剂在小鼠中的口服和局部以及口服抗病毒功效。 眼部HSV-1感染的鼠模型。第二个目标将使用最有效的口头和局部 在豚鼠和家兔原发性和再活化模型中测试其安全性、PK和疗效 眼部HSV-1感染。最后的目的3，我们将考察Na-PBA和无钠PBA的潜力 制剂与现有的抗病毒疗法协同作用，以确定其作为附加模式的潜力， 现有的治疗。后者是可能的和重要的，因为PBA是一种罕见的药物，通过减轻ER 压力和帮助宿主细胞对病毒感染的反应，从而减少出现的机会 抵抗病毒的能力。我们组建了一个多学科团队，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必要的FDA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.