RNA interference is a natural antiviral mechanism that could be harnessed to combat SARS-CoV-2 infection by targeting and destroying the viral RNA. We identified potent lipophilic small interfering RNA (siRNA) conjugates targeting highly conserved regions of SARS-CoV-2 outside of the spike-encoding region capable of achieving ≥3-log viral reduction. Serial passaging studies demonstrated that a two-siRNA combination prevented development of resistance compared to a single siRNA approach. Viral resistance to single siRNA treatment occurred due to emergence of point mutations at critical positions required for siRNA-mediated target binding and cleavage, which led to a loss of siRNA efficacy. With a two-siRNA combination, emergence of mutations within the siRNA binding site was abolished. When delivered intranasally, two-siRNA combination protected Syrian hamsters from weight loss and lung pathology by viral infection upon prophylactic administration but not following onset of infection. Together, the data support potential utility of RNAi as a prophylactic approach with high resistance barrier to counteract SARS-CoV-2 emergent variants and complement vaccination. Most importantly, given that the siRNAs can be rapidly developed from a new pathogen sequence, this strategy has implications as a new type of preventive medicine that may protect against future coronavirus pandemics.

中文翻译：

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使用两种 siRNA 组合的 SARS-CoV-2 临床前模型中的高耐药屏障和预防性保护


RNA 干扰是一种天然的抗病毒机制，可以通过靶向和破坏病毒 RNA 来对抗 SARS-CoV-2 感染。我们确定了有效的亲脂性小干扰 RNA （siRNA） 偶联物，这些偶联物靶向刺突编码区之外的 SARS-CoV-2 高度保守区域，能够实现 ≥3-log 病毒还原。连续传代研究表明，与单一 siRNA 方法相比，双 siRNA 组合可防止耐药性的发展。病毒对单个 siRNA 处理的耐药性是由于在 siRNA 介导的靶标结合和切割所需的关键位置出现点突变，从而导致 siRNA 疗效丧失。使用 2-siRNA 组合，消除了 siRNA 结合位点内突变的出现。当鼻内给药时，双 siRNA 组合可在预防性给药时保护叙利亚仓鼠免受病毒感染的体重减轻和肺部病变，但在感染发作后则不然。总之，这些数据支持 RNAi 作为具有高耐药屏障的预防方法的潜在效用，以对抗 SARS-CoV-2 新出现的变体和补充疫苗接种。最重要的是，鉴于 siRNA 可以从新的病原体序列中快速开发，这种策略作为一种新型的预防药物具有意义，可以预防未来的冠状病毒大流行。