Engineering protease-resistant antiviral peptide inhibitors for SARS-CoV-2

目前还没有针对SARS-CoV-2的疫苗或治疗方法。一种简单的预防性抗病毒策略将 现在就保护天真的人不受感染。在未来，当疫苗应该可用时，一种预防性的 对于没有产生适当免疫反应的个人来说，抗病毒药物将是必不可少的。靶向抗病毒药物 病毒进入宿主细胞已被证明对多种病毒疾病有效。进入/融合 冠状病毒(包括SARS-CoV-2)的形成过程是由病毒包膜糖蛋白(S)介导的。协调一致的行动 由受体结合域和融合域进行融合所需。基于病毒附着(和感染 在某些情况下)，在融合结构域中发生大规模构象重排，驱动因素是 一种将蛋白质重折叠直接连接到膜融合的结构。这种结构的形成可以是 以融合抑制肽(C-末端七肽重复序列或HRC肽)为靶点，以防止适当的 S中HRC和HRN结构域的结合我们发现一种脂质与一种抑制性物质的结合 多肽将多肽导向细胞膜，增加抗病毒效果。类似脂肽预防 感染多种病毒(麻疹、尼帕、副流感、流感)，可通过 气道口。即使在感染几天后，治疗对其中一些也是有效的。此外，我们还展示了 通过周期性地将α-氨基酸残基替换为β-氨基酸残基来修饰HRC肽的骨架。 氨基酸残基产生α/β-肽，保持抗病毒效力(针对艾滋病毒或副流感)，但 高度耐蛋白质水解性。我们最近产生了一种HRC脂肽，它对两种SARS都有效- CoV2和MERS体外活病毒，阻断SARS-CoV2在人呼吸道组织中的传播，并抑制 SARS-CoV-2在直接接触的雪貂之间的传播。在这里，我们建议将脂类 接合和骨架修饰策略以产生有效的SARS-CoV2感染抑制剂， 在体内显示出很长的半衰期。 1.通过优化SARS-CoV-2 HRC多肽融合抑制剂的抗病毒效力和生物利用度 合理的分子工程。α/β-脂肽候选的抗病毒效果将在 在真实的病毒感染和人类呼吸道模型中进行体外定量分析。 2.评价新型骨架修饰的α/β-脂肽融合抑制剂对机体的保护作用 仓鼠感染SARS-CoV-2。骨架修饰S-的体内生物分布及毒性分析 冠状病毒-2α/β-脂肽融合抑制剂及其体内效力和耐药机制的评估 用于冠状病毒预防和控制的安全有效的SARS CoV-2融合抑制剂的基础 心理治疗。

No vaccines or treatments for SARS-CoV-2 are yet available. A simple prophylactic antiviral strategy would protect naïve individuals from infection now. In the future, when vaccines should be available, a prophylactic antiviral will be essential for individuals who do not mount a suitable immune response. Antivirals that target viral entry into the host cell have been proven effective against a wide range of viral diseases. The entry/fusion process for CoV (including SARS-CoV-2) is mediated by the viral envelope glycoprotein (S). Concerted action by the receptor-binding domain and the fusion domain is required for fusion. Upon viral attachment (and uptake in certain cases), large-scale conformational rearrangements occur in the fusion domain, driven by formation of a structure that couples protein refolding directly to membrane fusion. The formation of this structure can be targeted by fusion inhibitory peptides (C-terminal heptad repeat or HRC peptides) that prevent proper apposition of the HRC and HRN domains in S. We have found that conjugation of a lipid to an inhibitory peptide directs the peptide to cell membranes and increases antiviral efficacy. Analogous lipo-peptides prevent infection by several viruses (measles, Nipah, parainfluenza, influenza), and can be administered via the airway. Treatment is effective for some of these even several days after infection. In addition, we have shown that modifying the backbone of an HRC peptide via periodic replacement of α-amino acid residues with β- amino acid residues generates α/β-peptides that retain antiviral potency (toward HIV or parainfluenza) but are highly resistant to proteolysis. We recently generated an HRC lipopeptide that is effective against both SARS- CoV2 and MERS live viruses in vitro, blocks spread of SARS-CoV2 in human airway tissue, and inhibits transmission of SARS-CoV-2 between ferrets in direct contact. Here we propose to combine the lipid conjugation and backbone-modification strategies to generate potent inhibitors of SARS-CoV2 infection that display a long half-life in vivo. 1. Optimize the antiviral potency and bioavailability of SARS-CoV-2 HRC peptide fusion inhibitors via rational molecular engineering. Antiviral efficacy of α/β-lipopeptide candidates will be measured in quantitative in vitro assays, in authentic virus infection, and in a human airway model. 2. Evaluate the protection afforded by new backbone-modified α/β-lipopeptide fusion inhibitors against SARS-CoV-2 infection in hamsters. Analysis of in vivo biodistribution and toxicity of backbone modified S- CoV-2 α/β-lipopeptide fusion inhibitors and assessment of in vivo potency and resistance mechanisms will lay the foundation for a safe and effective SARS CoV-2 fusion inhibitor for coronavirus prevention and therapy.