Development of antivirals for newly emerging pathogens Ebola and Marburg.

描述(申请人提供)：埃博拉病毒(EBOV)和马尔堡病毒(MARV)是构成丝状病毒科的包膜病毒的两个属。它们是最致命的人类病原体之一，导致严重的出血热，对埃博夫病毒-扎伊尔的死亡率高达90%。目前还没有疫苗或特定的抗病毒药物可供人类使用。我们建议将我们的基础研究成果应用于开发针对丝状病毒感染的新的抗病毒策略。这一建议是基于我们最近的发现，即将胆固醇基团连接到多肽融合抑制剂上产生3个主要优点：(1)增加效力，(2)将多肽与融合激活部位的病毒定位，(3)增强药代动力学特性。通过将序列优化和胆固醇标记相结合，我们建议开发在体外抑制丝状病毒的高效多肽融合抗病毒药物，并在相关的丝病毒感染动物模型中测试它们的治疗潜力。这些融合/进入抑制肽将被设计成“跟随”病毒到与细胞膜的融合部位，从而克服在细胞内隔间融合的病毒使用肽抑制剂的主要障碍。我们建议通过以下方法开发丝状病毒融合抑制物：目的1.设计和测试针对质膜的丝状病毒融合抑制肽，使用(A)生物物理分析引导的序列优化来增强多肽与靶序列的相互作用，以及(B)针对融合激活部位的膜靶向。目的2.在致死性感染的小鼠模型中，评估融合抑制剂对EBOV感染的保护作用。我们将确定(A)目标多肽的生物利用度，以及(B)在挑战实验中的有效性。因此，我们将获得有效性的原则证据，使我们能够选择具有最大体内潜力的多肽进行进展。这一提议的最重要的高度影响在于将为融合在内体中的包膜病毒建立概念验证。新策略将克服在细胞内融合的病毒使用多肽抗病毒药物的障碍，这些病毒包括正粘病毒(流感)、黄斑病毒(西尼罗河病毒、登革病毒)、冠状病毒(严重急性呼吸综合征)、阿雷纳病毒(Junin、Lassa)，所有这些病毒都共享类似的融合机制。 公共卫生相关性：丝状病毒(即埃博拉病毒和马尔堡病毒)是对人类的真正和明显的威胁，可以而且已经被武器化。我们将开发基于多肽的丝状病毒融合/进入抑制剂，这些多肽被设计为“跟随”病毒到其与细胞膜的融合部位。这项提议旨在为开发一种治疗方法奠定基础，因此本身具有临床意义，因为迫切需要治疗出血热和相关疾病。这一提议最重要的重大影响在于将为在内体中融合的包膜病毒建立概念验证，包括正粘病毒(流感)、黄斑病毒(西尼罗河病毒、登革病毒)、冠状病毒(严重急性呼吸综合征)、阿拉伯病毒(Junin、Lassa)，所有这些病毒都共享类似的融合机制。

DESCRIPTION (provided by applicant): Ebola viruses (EBOV) and Marburg virus (MARV) are two genera of enveloped viruses that constitute the family of Filoviridae. They are among the most lethal human pathogens, causing a severe hemorrhagic fever with mortality rates up to 90% for EBOV-Zaire. No vaccine or specific antiviral is available for human use. We propose to apply the results of our fundamental research to the development of a new antiviral strategy for filovirus infections. The proposal is based on our recent discovery that attachment of a cholesterol group to a peptide fusion inhibitor yields 3 major advantages: (1) increased potency, (2) localization of the peptide with the virus at the site of fusion activation, and (3) enhanced pharmacokinetic properties. By combining sequence optimization with cholesterol tagging, we propose to develop highly effective peptide fusion antivirals that inhibit filoviruses in vitro, and to test their therapeutic potential in a relevant animal model of filovirus infection. These fusion/entry inhibitory peptides will be designed to "follow" the virus to the site of fusion with the cell membrane, thus overcoming the major obstacle to the use of peptide inhibitors for viruses that fuse in intracellular compartments. We propose to develop filovirus fusion inhibitors by: Aim 1. Design and test filovirus fusion inhibitory peptides that are targeted to the plasma membrane, using (a) biophysical analysis-guided sequence optimization to enhance peptide interaction with the target sequence, and (b) membrane targeting to the site of fusion activation. Aim 2. Assess the effectiveness of the fusion inhibitors at protecting against EBOV infection in a murine model of lethal infection. We will determine (a) bioavailability of the targeted peptides, and (b) efficacy in challenge experiments. We will thereby obtain proof of principle for efficacy, allowing us to select peptides for advancement that have the most in vivo potential. The overarching high impact of this proposal lies in the proof-of-concept that will be established for enveloped viruses that fuse in the endosome. The new strategy would overcome the barrier to use of peptide antivirals for viruses that fuse in intracellular compartments, including orhomyxoviruses (influenza), flaviruses (West Nile virus, Dengue virus), coronaviruses (severe acute respiratory syndrome), arenaviruses (Junin, Lassa), all sharing a similar fusion machinery. PUBLIC HEALTH RELEVANCE: Filoviruses (i.e. Ebola and Marburg virus) are a real and clear threat to humans that can be and have been weaponized. We will develop filovirus fusion/entry inhibitors based on peptides that are designed to "follow" the virus to its site of fusion with the cell membrane. This proposal aims to lay the groundwork for developing a therapeutic and is therefore of clinical relevance in itself, since therapy for hemorrhagic fevers and associated diseases is urgently needed. The overarching high impact of this proposal lies in the proof-of-concept that will be established for enveloped viruses that fuse in the endosome, including orhomyxoviruses (influenza), flaviruses (West Nile virus, Dengue virus), coronaviruses (severe acute respiratory syndrome), arenaviruses (Junin, Lassa), all sharing a similar fusion machinery.