Gene Therapy Program, Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Mol Genet Metab. 2011 Nov;104(3):395-403. doi: 10.1016/j.ymgme.2011.06.002. Epub 2011 Jun 12.
Gene transfer vectors based on adeno-associated virus 8 (AAV8) are highly efficient in liver transduction and can be easily administered by intravenous injection. In mice, AAV8 transduces predominantly hepatocytes near central veins and yields lower transduction levels in hepatocytes in periportal regions. This transduction bias has important implications for gene therapy that aims to correct metabolic liver enzymes because metabolic zonation along the porto-central axis requires the expression of therapeutic proteins within the zone where they are normally localized. In the present study we compared the expression pattern of AAV8 expressing green fluorescent protein (GFP) in liver between mice, dogs, and non-human primates. We confirmed the pericentral dominance in transgene expression in mice with AAV8 when the liver-specific thyroid hormone-binding globulin (TBG) promoter was used but also observed the same expression pattern with the ubiquitous chicken β-actin (CB) and cytomegalovirus (CMV) promoters, suggesting that transduction zonation is not caused by promoter specificity. Predominantly pericentral expression was also found in dogs injected with AAV8. In contrast, in cynomolgus and rhesus macaques the expression pattern from AAV vectors was reversed, i.e. transgene expression was most intense around portal areas and less intense or absent around central veins. Infant rhesus macaques as well as newborn mice injected with AAV8 however showed a random distribution of transgene expression with neither portal nor central transduction bias. Based on the data in monkeys, adult humans treated with AAV vectors are predicted to also express transgenes predominantly in periportal regions whereas infants are likely to show a uniform transduction pattern in liver.
基于腺相关病毒 8（AAV8）的基因转移载体在肝脏转导中非常高效，并且可以通过静脉注射轻松给药。在小鼠中，AAV8 主要转导中央静脉附近的肝细胞，而在门周区域的肝细胞中转导水平较低。这种转导偏向对于旨在纠正代谢性肝脏酶的基因治疗具有重要意义，因为沿门-中央轴的代谢区带需要在其正常定位的区域内表达治疗性蛋白。在本研究中，我们比较了在小鼠、狗和非人类灵长类动物中 AAV8 表达绿色荧光蛋白（GFP）的肝脏表达模式。我们证实，当使用肝脏特异性甲状腺激素结合球蛋白（TBG）启动子时，AAV8 在小鼠中转基因表达具有中央优势，但也观察到相同的表达模式与普遍存在的鸡β-肌动蛋白（CB）和巨细胞病毒（CMV）启动子，这表明转导区带不是由启动子特异性引起的。在注射 AAV8 的狗中也发现了主要的中央优势表达。相比之下，在食蟹猴和恒河猴中，AAV 载体的表达模式相反，即转基因表达在门区周围最强，而在中央静脉周围较弱或不存在。然而，注射 AAV8 的幼年恒河猴和新生小鼠表现出随机的转基因表达分布，既没有门区也没有中央区带的转导偏向。基于猴子的数据，接受 AAV 载体治疗的成年人类预计也主要在门周区域表达转基因，而婴儿则可能在肝脏中表现出均匀的转导模式。
