Anitviral Activity of Thioaptamers Against West Nile Virus

描述：由于病毒与宿主大分子机制的密切相互作用以及病毒在细胞内的复制，抗病毒药物的开发已被证明是困难的。因此，很少有抗病毒药物能够进入商业市场。特别是，抗病毒药物在对付新出现疾病和/或潜在生物武器的病毒方面取得的成功非常有限。我们对抗病毒药物的设计采取了合理的方法，并设计了用于抗病毒药物的硫核酸适体。适配体是从随机或高序列多样性文库中选择的核酸分子，它们与目标（如蛋白质）紧密结合的能力。然后使用称为体外选择的迭代过程来丰富与目标高亲和力的物种文库。利用硫代寡核苷酸适配体的组合选择，我们选择了一种二硫代适配体（XBY-6），它选择性地结合转录因子NF-kB，目的是利用该硫代适配体调节宿主对感染的免疫反应。此外，我们还发现了第二个二硫化适配体XBY-S2，它选择性地与另一个转录因子Activator Protein 1结合。使用NIAID B类病原体西尼罗病毒作为黄病毒模型系统，我们发现XBY-6和XBY-S2可以调节西尼罗病毒在小鼠模型中的致命攻击，并保护50-80%的小鼠免于死亡。本次合作申请的目的是阐明XBY-6和XBY-S2的作用机制，优化XBY-6和XBY-S2在小鼠体内的抗病毒活性，并进行安全性和有效性的临床前试验。

(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.