mRNA-encoded Cas13 as a pan-respiratory antiviral

项目摘要 已知的感染人类的病毒有200多种，它们占全球死亡率的6.6%。我们有 针对10种病毒的大约91种药物和仅针对16种病毒的疫苗。 疫苗效力面临的挑战；在新城疫大流行期间已经清楚地证明了这一点。当期药物 发展的重点是小分子和中和抗体，这需要高剂量或频繁 重新给药以获得功能结果，也受到了抗原性变化的挑战。因此，它是至关重要的 以满足对更高效率和更广泛谱的抗病毒药物的需求。为了满足这一需求，我们提议 一种完全不同的抗病毒开发范式，一种由mRNA编码的可激活RNase，Cas13，作为一种 用于泛呼吸治疗的平台。Cas13代表一个可编程的RNase，它可以直接针对和 降解多种病毒信使或基因组RNA。合成的mRNA正被用来传递核糖核酸酶，因为它 允许瞬时、非病毒传递，与其他基因治疗载体1相比，安全性更高。vt.给出 用一种基于Cas13的单一信使核糖核酸编码的药物实现泛呼吸道结果不是微不足道的关键步骤 为了实现这一目标，可以通过关注传播中三种最具影响力的呼吸道病毒来实现， RSV、流感和SARS-CoV-2。到目前为止，我们的团队是第一个展示mrna编码的有效性的团队。 Cas13在体外和体内通过雾化吸入肺递送抗流感小鼠模型和SARS- 我们最近在《自然生物技术》杂志上发表了仓鼠模型中的CoV-2。为了实现一药多用 RSV、流感和SARS-CoV-2有一些重要的问题/挑战需要应对。因此，我们 将确定适合多种呼吸道病原体的Cas13菌种，并探讨其作用机制 针对每种病毒的Cas13的作用。我们还将展示单一药物对呼吸道合胞病毒、流感和SARS的疗效- CoV-2在小鼠和仓鼠模型中的体内应用，作为对单个病毒感染的治疗，在联合治疗期间 预防感染(流感和SARS-CoV-2)，并减少SARS-CoV-2的传播。

Project Summary There are over 200 viruses known to infect humans and they contribute to 6.6% of global mortality. We have approximately 91 drugs for 10 viral species and vaccines for only 16. Reassortment and antigenic changes pose challenges to vaccine efficacy; this has clearly been demonstrated during the COVID pandemic. Current drug development is focused on small molecules and neutralizing antibodies, which require high doses or frequent re-dosing to obtain functional outcomes and have also been challenged by antigenic changes. Thus, it is crucial to address the need for higher efficiency and broader spectrum antivirals. To address this need we are proposing an entirely different paradigm for antiviral development, an mRNA-encoded activatable RNase, Cas13, as a platform for a pan-respiratory treatment. Cas13 represents a programmable RNase that can directly target and degrade multiple viral messenger or genomic RNA. Synthetic mRNA is being used to deliver the RNase, as it allows for transient, non-viral delivery, with an improved safety profile over other gene therapy vectors1. Given achieving pan-respiratory results with a single mRNA-encoded Cas13 based drug is not trivial, critical steps towards that goal can be achieved by focusing on the three most impactful respiratory viruses in circulation, RSV, influenza and SARS-CoV-2. To date, our team was the first to demonstrate efficacy of mRNA-encoded Cas13 in vitro and in vivo via nebulizer-based lung delivery against influenza in the mouse model and SARS- CoV-2 in the hamster model in our recent publication in Nature Biotechnology. In order to achieve one drug for RSV, influenza and SARS-CoV-2 there are important questions/challenges that will need to be met. Thus, we will determine the optimal Cas13 species for multiple respiratory pathogens and investigate the mechanism of action of Cas13 for each virus. We will also demonstrate single drug efficacy against RSV, influenza and SAR- CoV-2 in vivo in mouse and hamster models, given as treatments for the individual viral infections, during co- infection (influenza and SAR-CoV-2), and to mitigate transmission of SARS-CoV-2.