Highly selective radioisotope modification to enable adenovirus tracking in vivo

描述（由申请人提供）：基于哺乳动物病毒的治疗剂在遗传疾病、癌症治疗和疫苗开发方面具有巨大潜力。腺病毒（Ad）在这些应用中起主导作用，因为它极其有效地递送遗传有效载荷，具有大的转基因能力，能够感染分裂和静止细胞，并且几乎不造成插入诱变的风险。随着基于腺病毒的治疗方法的成熟，理解和操纵生物分布在提高疗效中起着关键作用已经变得显而易见。我们的长期目标是开发技术，使直接和选择性的修改哺乳动物病毒的成像试剂。该提案的目的是开发用PET试剂修饰腺病毒的高度特异性化学方法。我们的中心假设是，化学选择性反应将允许灵活的修改与PET试剂没有显着的影响，无论是生物分布或活力。这种方法所需的特异性无法通过传统的蛋白质化学获得。我们已经开发了一种两步标记方案，需要非天然氨基酸和/或糖的代谢放置，然后使用“点击”化学或施陶丁格连接进行精确选择性的化学修饰。这项研究的基本原理是，一旦开发出一种简便灵活的成像平台，它将加速Ad的转化研究，预计它将广泛适用于其他病毒。

DESCRIPTION (provided by applicant): Therapeutics based upon mammalian viruses have tremendous potential in the context of genetic disease, cancer therapy and vaccine development. Adenovirus (Ad) plays a leading role in these applications as it is delivers genetic payloads extremely efficiently, has large transgene capacity, is able to infect both dividing and quiescent cells, and poses little risk for insertional mutagenesis. As adenovirus based therapeutics mature it has become obvious that understanding and manipulating biodistribution plays a critical role in increasing efficacy. Our long-term goal is the development of techniques that allow the straightforward and selective modification of mammalian viruses with imaging reagents. The objective of this proposal is to develop highly specific chemical approaches to adenovirus modification with PET reagents. Our central hypothesis is that chemoselective reactions will allow flexible modification with PET reagents without significant impact on either biodistribution or viability. The specificity required for this approach cannot be accessed with traditional protein chemistry. We have developed a two-step labeling protocol requiring the metabolic placement of unnatural amino acids and/or sugars followed by exquisitely selective chemical modification using either "click" chemistry or the Staudinger Ligation. The rationale for the proposed research is once a facile and flexible imaging platform has been developed it will accelerate translational studies with Ad and, as it is expected be broadly applicable, other viruses.