Unnatural Amino Acid Incorporation onto Adenoviral (Ad) Coat Proteins Facilitates Chemoselective Modification and Retargeting of Ad Type 5 Vectors
Unnatural Amino Acid Incorporation onto Adenoviral (Ad) Coat Proteins Facilitates Chemoselective Modification and Retargeting of Ad Type 5 Vectors
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DOI：
10.1128/jvi.00118-11
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发表时间：
2011-08-01
影响因子：
5.4
通讯作者：
Carrico, Isaac Sheridan
中科院分区：
文献类型：
--
作者：
Banerjee, Partha Sarathi;Ostapchuk, Philomena;Carrico, Isaac Sheridan
腺病毒载体的表面修饰可以提高组织选择性靶向，减弱免疫原性，并使粒子生物分布成像，从而显着提高治疗潜力。目前，表面工程受到多种因素的限制，包括对病毒适应性的影响，功能的有限访问或对修饰位点的不完全控制。在这里，我们报告了一个两步标记过程，涉及一个独特的反应性非天然氨基酸，叠氮基高丙氨酸（Aha），随后高度特异性的化学修饰的初始代谢位置。由于腺病毒的遗传修饰是不必要的，载体生产非常简单。Aha掺入证明对病毒产生或所得颗粒的感染性没有明显影响。表面暴露的叠氮化物的“点击”化学改性是高度选择性的，允许连接广泛的功能。用叶酸（一种已知的癌症靶向部分）修饰人5型腺病毒（hAd5），以叶酸受体依赖性方式使鼠乳腺癌细胞（4T1）的感染增加了20倍。这项研究表明，掺入非天然氨基酸可以提供一个灵活的，直接的途径，选择性的化学修饰的腺病毒载体。
Surface modification of adenovirus vectors can improve tissue-selective targeting, attenuate immunogenicity, and enable imaging of particle biodistribution, thus significantly improving therapeutic potential. Currently, surface engineering is constrained by a combination of factors, including impact on viral fitness, limited access to functionality, or incomplete control over the site of modification. Here, we report a two-step labeling process involving an initial metabolic placement of a uniquely reactive unnatural amino acid, azidohomoalanine (Aha), followed by highly specific chemical modification. As genetic modification of adenovirus is unnecessary, vector production is exceedingly straightforward. Aha incorporation demonstrated no discernible impact on either virus production or infectivity of the resultant particles. "Click" chemical modification of surface-exposed azides was highly selective, allowing for the attachment of a wide range of functionality. Decoration of human adenovirus type 5 (hAd5) with folate, a known cancer-targeting moiety, provided an similar to 20-fold increase in infection of murine breast cancer cells (4T1) in a folate receptor-dependent manner. This study demonstrates that incorporation of unnatural amino acids can provide a flexible, straightforward route for the selective chemical modification of adenoviral vectors.