Anitviral Activity of Thioaptamers Against West Nile Virus

（修订摘要）描述：由于病毒与宿主大分子机制的密切相互作用和病毒的细胞内复制，抗病毒剂的开发已被证明是困难的。因此，很少有抗病毒剂进入商业市场。特别地，抗病毒剂针对作为新兴疾病和/或潜在生物武器的病毒的成功非常有限。我们采用合理的方法设计了抗病毒药物，并设计了用于抗病毒药物的硫代适体。适体是从随机或高序列多样性文库中选择的核酸分子，其具有紧密结合目标靶标（如蛋白质）的能力。然后使用称为体外选择的迭代过程来富集文库中对靶标具有高亲和力的物种。使用硫代磷酸酯寡核苷酸适体的组合选择，我们选择了选择性结合转录因子NF-κ B的二硫代适体（XBY-6），目的是使用该硫代适体来调节宿主对感染的免疫应答。此外，我们发现第二个二硫代适体XBY-S2选择性结合另一种转录因子激活蛋白1。使用NIAID B类病原体西尼罗病毒作为黄病毒的模型系统，我们发现XBY-6和XBY-S2将调节小鼠模型中西尼罗病毒的另外的致死性攻击，并保护50-80%的小鼠免于死亡。本次合作资助申请的目的是阐明XBY-6和XBY-S2的作用机制，优化XBY-6和XBY-S2在小鼠中的抗病毒活性，并进行临床前安全性和有效性测试。

(Revised Abstract) DESCRIPTION: Developmental of antiviral agents has proved to be difficult due to the close interactions of viruses with host macromolecular machinery and intracellular replication of viruses. As such, few antiviral agents have made it to the commercial marketplace. In particular, antiviral agents have met with very limited success against viruses that are emerging diseases and/or potential biological weapons. We have taken a rational approach to the design of antiviral agents, and designed thioaptamers for use of antiviral agents. Aptamers are nucleic acid molecules that have been selected from random or high-sequence diversity libraries on their ability to tightly bind to the target (such as a protein) of interest. An iterative process known as in vitro selection is then used to enrich the library for species with high affinity to the target. Using combinatorial selection of phosphorothioate oligonucleotide aptamers, we have selected a dithioated aptamer (XBY-6) that selectively binds transcription factor NF-kB with the aim of using this thioaptamer to modulate the host immune response to infection. In addition, we have found that a second dithioated aptamer XBY-S2, that selectively binds to another transcription factor, Activator Protein 1. Using the NIAID Category B pathogen West Nile virus as a model system for flaviviruses we have found that XBY-6 and XBY-S2 will modulate an otherwise lethal challenge of West Nile virus in the mouse model and protect 50-80% of mice from death. The objective of this cooperative grant application is to elucidate the mechanism(s) of action of XBY-6 and XBY-S2, optimize the antiviral activity of XBY-6 and XBY-S2 in mice, and undertake preclinical testing for safety and efficacy.