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。一个简单的预防性抗病毒策略 保护天真的人免受感染。在未来，当疫苗应该可用时， 抗病毒药物对于没有产生适当免疫应答的个体是必不可少的。抗病毒药物， 病毒进入宿主细胞已被证明对广泛的病毒性疾病有效。融合/Fusion CoV（包括SARS-CoV-2）的形成过程是由病毒包膜糖蛋白（S）介导的。一致行动 受体结合结构域和融合结构域是融合所必需的。在病毒附着（和摄取）后， 在某些情况下），大规模的构象重排发生在融合结构域中， 一种将蛋白质重折叠直接与膜融合结合的结构。这种结构的形成可以 被融合抑制肽（C-末端七肽重复或HRC肽）靶向， S.我们已经发现，脂质与抑制剂的缀合 肽将肽引导至细胞膜并增加抗病毒功效。类似脂肽可预防 感染的几种病毒（麻疹，尼帕，副流感，流感），并可以通过管理 气道。治疗是有效的，其中一些甚至在感染后几天。此外，我们还表明， 通过用β-氨基酸残基周期性替换α-氨基酸残基来修饰HRC肽的骨架， 氨基酸残基产生α/β-肽，其保留抗病毒效力（针对HIV或副流感病毒）， 对蛋白水解有很强的抵抗力。我们最近合成了一种HRC脂肽，它对SARS和 CoV 2和MERS活病毒在体外，阻断SARS-CoV 2在人气道组织中的传播， 在直接接触的雪貂之间传播SARS-CoV-2。在此，我们建议将脂质联合收割机 缀合和骨架修饰策略，以产生有效的SARS-CoV 2感染抑制剂， 在体内显示出很长的半衰期。 1.优化SARS-CoV-2 HRC肽融合抑制剂的抗病毒效力和生物利用度 理性分子工程α/β-脂肽候选物的抗病毒功效将在 在真实病毒感染和人气道模型中进行定量体外测定。 2.评价新型骨架修饰的α/β-脂肽融合抑制剂对以下疾病的保护作用： SARS-CoV-2感染仓鼠。骨架修饰的S-25的体内生物分布和毒性分析 CoV-2 α/β-脂肽融合抑制剂和体内效力和耐药机制的评估将奠定 为安全有效的SARS CoV-2融合抑制剂预防冠状病毒奠定了基础， 疗法

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.