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方法在遗传疾病、癌症治疗和疫苗开发方面具有巨大的潜力。腺病毒（Ad）在这些应用中起着主导作用，因为它非常有效地传递遗传有效载荷，具有很大的转基因能力，能够感染分裂细胞和静止细胞，并且插入突变的风险很小。随着基于腺病毒的治疗方法的成熟，理解和控制生物分布在提高疗效方面起着至关重要的作用。我们的长期目标是开发一种技术，允许用成像试剂对哺乳动物病毒进行直接和选择性的修饰。本建议的目的是开发高度特异性的化学方法，用PET试剂修饰腺病毒。我们的中心假设是，化学选择性反应将允许灵活的修饰PET试剂，而不会对生物分布或生存能力产生重大影响。这种方法所需的特异性无法通过传统的蛋白质化学获得。我们开发了一种两步标记方案，要求代谢放置非天然氨基酸和/或糖，然后使用“点击”化学或Staudinger结扎进行精细的选择性化学修饰。拟议研究的基本原理是，一旦开发出一种简便灵活的成像平台，它将加速对Ad和其他病毒的转译研究，因为它有望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.