Displaying High-affinity Ligands on Adeno-associated Viral Vectors Enables Tumor Cell-specific and Safe Gene Transfer
Displaying High-affinity Ligands on Adeno-associated Viral Vectors Enables Tumor Cell-specific and Safe Gene Transfer
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DOI：
10.1038/mt.2012.186
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发表时间：
2013-01-01
影响因子：
12.4
通讯作者：
Buchholz, Christian J.
中科院分区：
文献类型：
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作者：
Muench, Robert C.;Janicki, Hanna;Buchholz, Christian J.
腺相关病毒（AAV）基因转移载体在临床试验中表现出良好的治疗效果，近年来受到越来越多的关注。然而，由于其广泛的向性，它们在体内基因治疗中的巨大潜力只能部分地被利用。目前的细胞表面靶向策略将载体向性扩展到转导自然感染效率低的细胞类型，但未能限制或完全重新定向AAV的向性。假设这种限制可以通过为天然受体盲的AAV载体配备高亲和力配体来克服，我们将设计的锚蛋白重复序列蛋白（DARPin）展示为在AAV衣壳上的VP 2融合蛋白，所述AAV衣壳被消融用于天然初级受体结合。这些第二代靶向载体证明了在单一培养物和混合培养物中区分靶细胞和非靶细胞的尚未实现的效率。此外，DARPin-AAV载体将自杀基因精确地递送到肿瘤组织，并显著减少肿瘤生长而不引起致命的肝毒性。后者导致用具有未修饰衣壳的常规AAV载体处理的动物死亡，所述未修饰衣壳在肝组织中积累并且未能影响肿瘤生长。这种新的靶向平台将是需要限制性和细胞类型特异性体内基因递送的翻译方法的关键。
Gene transfer vectors derived from the adeno-associated virus (AAV) have recently received increasing attention due to substantial therapeutic benefit in several clinical trials. Nevertheless, their great potential for in vivo gene therapy can only be partially exploited owing to their broad tropism. Current cell surface targeting strategies expanded vector tropism towards transduction of cell types that are inefficiently infected naturally, but failed to restrict or fully re-direct AAV's tropism. Hypothesizing that this limitation can be overcome by equipping natural receptor-blinded AAV vectors with high-affinity ligands, we displayed designed ankyrin repeat proteins (DARPin) as VP2 fusion proteins on AAV capsids ablated for natural primary receptor binding. These second generation targeting vectors demonstrated an as of yet unachieved efficiency to discriminate between target and non-target cells in mono- and mixed cultures. Moreover, DARPin-AAV vectors delivered a suicide gene precisely to tumor tissue and substantially reduced tumor growth without causing fatal liver toxicity. The latter caused death in animals treated with conventional AAV vectors with unmodified capsids, which accumulated in liver tissue and failed to affect tumor growth. This novel targeting platform will be key to translational approaches requiring restricted and cell type-specific in vivo gene delivery.