DataSheet1_Chimeric Mice Engrafted With Canine Hepatocytes Exhibits Similar AAV Transduction Efficiency to Hemophilia B Dog.PDF

Adeno-associated virus (AAV) mediated gene therapy has been successfully applied in clinical trials, including hemophilia. Novel AAV vectors have been developed with enhanced transduction and specific tissue tropism. Considering the difference in efficacy of AAV transduction between animal models and patients, the chimeric xenograft mouse model with human hepatocytes has unique advantages of studying AAV transduction efficiency in human hepatocytes. However, it is unclear whether the results in humanized mice can predict AAV transduction efficiency in human hepatocytes. To address this issue, we studied the AAV transduction efficacy in canine hepatocytes in both canine hepatocyte xenografted mice and real dogs. After administration of AAV vectors from different serotypes into canine hepatocyte xenograft mice, AAV8 induced the best canine hepatocyte transduction followed by AAV9, then AAV3, 7, 5 and 2. After administration of AAV/cFIX (cFIX-opt-R338L) vectors in hemophilia B dogs, consistent with the result in chimeric mice, AAV8 induced the highest cFIX protein expression and function, followed by AAV9 and then AAV2. These results suggest that mice xenografted with hepatocytes from different species could be used to predict the AAV liver transduction in real species and highlight this potential platform to explore novel AAV variants for future clinical applications.

腺相关病毒 (Adeno-associated virus, AAV) 介导的基因治疗已成功应用于包括血友病在内的多项临床试验。目前已开发出具备更高转导效能与组织特异性嗜性的新型AAV载体。鉴于动物模型与患者体内AAV转导功效存在差异，搭载人肝细胞的嵌合异种移植小鼠模型在研究人肝细胞中AAV转导效率方面具备独特优势。然而，目前尚不清楚人源化小鼠的实验结果能否预测人肝细胞内的AAV转导效率。为解决这一问题，我们分别在犬肝细胞异种移植小鼠与真实犬只中探究了AAV在犬肝细胞中的转导功效。将不同血清型的AAV载体注入犬肝细胞异种移植小鼠体内后，AAV8对犬肝细胞的转导效果最佳，其次为AAV9，随后依次为AAV3、7、5与2。在血友病B型犬体内注射AAV/cFIX（cFIX-opt-R338L）载体后，其结果与嵌合小鼠实验一致：AAV8诱导产生的cFIX蛋白表达量与活性均最高，其次为AAV9，随后为AAV2。本研究结果表明，移植异种肝细胞的小鼠模型可用于预测真实物种体内的AAV肝脏转导效果，同时凸显了该平台在探索新型AAV变体以用于未来临床应用方面的潜力。