Design of peptide entry inhibitors and delivery systems to target emerging henipa

副粘病毒引起重要的人类疾病，对全球疾病和死亡率有重大贡献。 两种人畜共患副粘病毒Hendra（HeV）和Nipah（NiV）由于其致命性而受到迫切关注。 和传染性。HeV和NiV通过结合细胞表面受体启动感染，并直接融合 进入细胞膜。受体结合分子（G）触发病毒融合蛋白（F）， 活性状态和F蛋白驱动融合的构象变化。七肽重复序列（HR）的分子模拟物 HeV F的区域可以阻止F达到融合就绪构象，并防止感染。我们发现 异源（副流感病毒3）肽作为抗HeV/NiV比同源肽更有效。 我们提出了一个独特的组合：（1）实验和结构分析的分子 融合和进入抑制机制，以设计最佳抑制剂;（2）动物模型研究，以测试 建议的抗病毒药物，以保护免受感染;（3）生物工程方法，以改善输送系统， 很有前途的抗病毒药物一个多学科的协作团队，带来独特的专业知识，协同研究： 1. HeV和NiV F蛋白的构象变化：设计有效肽的基础研究。 1.1同型和异型HRC融合抑制机制的结构分析 缩氨酸通过结合实验信息和我们的X射线晶体结构分析， 针对HPIV 3 F、HeV F和HPIV 3/HeV嵌合6 HB，将描述抑制肽的作用机制。 在结构和生物药理学上进行了探索。 1.2基于晶体结构数据的改进肽的设计和测试。 1.3 HPIV 3 HRC融合抑制抗性变体的分析。 2.肽在体内保护免受活病毒感染的有效性。有效的肽（目标1）将 在雪貂和猫模型中测试它们保护免受HeV和NiV感染的能力， 急性HeV/NiV感染。将讨论治疗以及暴露前和暴露后预防。 微/纳米粒子将被设计为提供最有前途的抑制剂的持续递送，以探索 持续释放可以改善体内抗病毒功效并提供临床策略的假设， 在危机情况下是可行的。目标2的反馈将直接导致目标1的新实验。 这些结果将导致：（1）对病毒融合、侵入和融合的分子机制有新的认识， 肽抑制剂的作用机制;（2）抗病毒药物的持续递送系统， 适用和临床相关;（3）体内抗病毒策略的验证，以及现实的 候选抗病毒肽。鉴于副粘病毒的重要性， 对人类健康的影响以及新平台的潜在广泛适用性， 这些新出现的人畜共患病病原体的临床/生物防御相关性。

Paramyxoviruses cause important human illnesses that contribute significantly to global disease and mortality. Two zoonotic paramyxoviruses, Hendra (HeV) and Nipah (NiV), are of urgent concern due to their lethal and transmissible nature. HeV and NiV initiate infection by binding to cell surface receptors, and fuse directly with the cell membrane to enter. The receptor-binding molecule (G) triggers the viral fusion protein (F) to its active state, and conformational changes in F protein drive fusion. Molecular mimics of the heptad repeat (HR) regions of HeV F can prevent F from reaching fusion-ready conformation, and prevent infection. We found that a heterologous (parainfluenza 3) peptide is more effective than the homologous peptide as an anti-HeV/NiV. We propose a distinctive combination of: (1) experimental and structural analysis of the molecular mechanisms of fusion and entry inhibition, to design optimal inhibitors; (2) animal model studies to test the proposed antivirals for protection from infection; (3) bioengineering approaches to improve delivery systems for promising antivirals. A multidisciplinary collaborative team, bringing unique expertise, synergizes to study: 1. Conformational changes in HeV and NiV F-protein: Basic research to design effective peptides. 1.1 Structural analysis of the mechanism of fusion inhibition by homotypic and heterotypic HRC peptides. By combining experimental information with analysis of our X-ray crystal structures of the 6HBs of HPIV3 F, HeV F and HPIV3/HeV chimeric 6HBs, the mechanism of action of inhibitory peptides will be explored structurally and biophysically. 1.2 Design and testing of improved peptides based on crystal structure data. 1.3 Analysis of HPIV3 HRC fusion inhibition-resistant variants. 2. Effectiveness of the peptides to protect from live viral infection in vivo. Effective peptides (aim 1) will be tested for their ability to protect against infection with HeV and NiV infection in the ferret and cat models of acute HeV/NiV infection. Treatment as well as pre- and post-exposure prophylaxis will be addressed. Micro/nanoparticles will be engineered to provide sustained delivery of the most promising inhibitors, to explore the hypothesis that sustained release can improve antiviral efficacy in vivo and provide a clinical strategy that would be feasible for crisis situations. Feedback from aim 2 will lead directly to new experiments in aim 1. The results will lead to: (1) New understanding about the molecular mechanisms of virus fusion, entry, and mechanisms of action of peptide inhibitors; (2) sustained delivery systems for antivirals that may be broadly applicable and clinically relevant; (3) validation of an antiviral strategy in vivo, and identification of realistic candidate antiviral peptides. The results will be significant in light of the importance of paramyxoviruses to human health and the potential broad applicability of the new platforms, in addition to the specific clinical/biodefense relevance of these emerging zoonotic pathogens.