An AAV Dual Vector Strategy Ameliorates the Stargardt Phenotype in Adult Abca4-/- Mice
An AAV Dual Vector Strategy Ameliorates the Stargardt Phenotype in Adult Abca4-/- Mice
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DOI：
10.1089/hum.2018.156
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发表时间：
2019-05-01
影响因子：
4.2
通讯作者：
MacLaren, Robert E.
中科院分区：
文献类型：
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作者：
McClements, Michelle E.;Barnard, Alun R.;MacLaren, Robert E.
最近在美国批准了用于治疗遗传性视网膜变性的第一种腺相关病毒（AAV）载体，证实了这种方法用于治疗许多其他疾病。一个主要的限制因素仍然是AAV转基因的大小限制在5 kb以下。Stargardt病是最常见的复发性遗传性失明形式，由ABCA 4突变引起，ABCA 4是编码ATP结合盒转运蛋白家族成员4的基因，其编码序列长度为6.8 kb。双载体方法增加了AAV基因治疗的能力，但代价是靶蛋白水平大幅降低，这可能不足以实现治疗效果。在这里，我们表明，双载体重组的功效取决于两个转基因之间的DNA重叠的长度。通过优化重组，全长ABCA 4蛋白在Abca 4（-/-）小鼠的光感受器外节中以足以减少双视黄酸形成并校正自体荧光表型的水平表达。这些观察结果支持在未来的临床试验中使用AAV基因疗法治疗Stargardt病的双载体方法。
The recent approval in the United States of the first adeno-associated viral (AAV) vector for the treatment of an inherited retinal degeneration validates this approach for the treatment of many other diseases. A major limiting factor continues to be the size restriction of the AAV transgene at under 5 kb. Stargardt disease is the most prevalent form of recessively inherited blindness and is caused by mutations in ABCA4, the gene that codes for ATP-binding cassette transporter protein family member 4, which has a coding sequence length of 6.8 kb. Dual vector approaches increase the capacity of AAV gene therapy, but at the cost of substantially reduced levels of target protein, which may be insufficient to achieve a therapeutic effect. Here we show that the efficacy of recombination of dual vectors is dependent on the length of DNA overlap between two transgenes. With optimized recombination, full-length ABCA4 protein is expressed in the photoreceptor outer segments of Abca4(-/-) mice at levels sufficient to reduce bisretinoid formation and correct the autofluorescent phenotype. These observations support a dual vector approach in future clinical trials using AAV gene therapy to treat Stargardt disease.