Abstract：
RNA ligands of retinoic acid-inducible gene I (RIG-I) are a promising class of oligonucleotide therapeutics with broad potential as antiviral agents, vaccine adjuvants, and cancer immunotherapies. However, their translation has been limited by major drug delivery barriers, including poor cellular uptake, nuclease degradation, and an inability to access the cytosol where RIG-I is localized. Here this challenge is addressed by engineering nanoparticles that harness covalent conjugation of 5\'-triphospate RNA (3pRNA) to endosome-destabilizing polymers. Compared to 3pRNA loaded into analogous nanoparticles via electrostatic interactions, it is found that covalent conjugation of 3pRNA improves loading efficiency, enhances immunostimulatory activity, protects against nuclease degradation, and improves serum stability. Additionally, it is found that 3pRNA could be conjugated via either a disulfide or thioether linkage, but that the latter is only permissible if conjugated distal to the 5\'-triphosphate group. Finally, administration of 3pRNA-polymer conjugates to mice significantly increases type-I interferon levels relative to analogous carriers that use electrostatic 3pRNA loading. Collectively, these studies have yielded a next-generation polymeric carrier for in vivo delivery of 3pRNA, while also elucidating new chemical design principles for covalent conjugation of 3pRNA with potential to inform the further development of therapeutics and delivery technologies for pharmacological activation of RIG-I.
摘要：
视黄酸诱导型基因I(RIG-I)的RNA配体是一类有前途的寡核苷酸治疗剂,具有作为抗病毒剂的广泛潜力,疫苗佐剂，和癌症免疫疗法。然而,他们的翻译受到主要药物输送障碍的限制，包括细胞摄取差，核酸酶降解，并且无法进入RIG-I定位的细胞质。在这里，我们通过工程化纳米颗粒来解决这一挑战，该纳米颗粒利用5'-三磷酸RNA（3pRNA）与内体去稳定聚合物的共价缀合。与通过静电相互作用加载到类似纳米颗粒中的3pRNA相比，我们发现3pRNA的共价缀合提高了装载效率，增强免疫刺激活性，防止核酸酶降解，提高血清稳定性。此外,我们发现3pRNA可以通过二硫键或硫醚键缀合，但后者只有在与5'-三磷酸基团共轭的情况下才是允许的。最后,与使用静电3pRNA加载的类似载体相比，向小鼠施用3pRNA-聚合物缀合物显着增加了I型干扰素水平。总的来说，这些研究已经产生了用于体内递送3pRNA的下一代聚合物载体，同时还阐明了3pRNA共价缀合的新化学设计原理，有可能为RIG-I的药理激活的治疗和递送技术的进一步发展提供信息。本文受版权保护。保留所有权利。
