Wang Q, Dong B, Firrman J, Wu W, Roberts S, Moore A R, Liu L S, Chin M P S, Diao Y, Kost J, Xiao W
School of Biomedical Sciences, Huaqiao University, Quanzhou, Fujian, China.
Sol Sherry Thrombosis Research Center, Temple University, Philadelphia, PA, USA.
Gene Ther. 2016 Jul;23(7):597-605. doi: 10.1038/gt.2016.34. Epub 2016 Apr 11.
The canine is the most important large animal model for testing novel hemophilia A (HA) treatment. It is often necessary to use canine factor VIII (cFIII) gene or protein for the evaluation of HA treatment in the canine model. However, different biological properties between cFVIII and human FVIII (hFVIII) indicated that the development of novel HA treatment may require careful characterization of non-human FVIII. To investigate whether the data obtained using cFVIII can translate to HA treatment in human, we analyzed the differential biological properties of canine heavy chain (cHC) and light chain (cLC) by comparing with human heavy chain (hHC) and light chain (hLC). The secretion of cHC was 5-30-fold higher than hHC, with or without light chains (LCs). cHC+hLC group exhibited ~18-fold increase in coagulation activity compared with hHC+hLC delivery by recombinant adeno-associated viral vectors. Unlike hHC, the secretion of cHC was independent of LCs. cLC improves the specific activity of FVIII by two- to threefold compared with hLC. Moreover, the cLC, but not cHC, contributes to the higher stability of cFVIII. Our results suggested that the cFVIII expression results in the canine model should be interpreted with caution as the cHC secreted more efficiently than hHC and cLC exhibited a more active and stable phenotype than hLC.
犬类是测试新型血友病A（HA）治疗方法的最重要的大型动物模型。在犬类模型中评估HA治疗方法时，通常需要使用犬类因子VIII（cFIII）基因或蛋白质。然而，cFVIII与人类FVIII（hFVIII）之间不同的生物学特性表明，新型HA治疗方法的开发可能需要仔细表征非人类FVIII。为了研究使用cFVIII获得的数据是否可以转化为人类的HA治疗，我们通过与人类重链（hHC）和轻链（hLC）比较，分析了犬类重链（cHC）和轻链（cLC）的差异生物学特性。无论有无轻链（LC），cHC的分泌都比hHC高5至30倍。与通过重组腺相关病毒载体递送hHC+hLC相比，cHC+hLC组的凝血活性提高了约18倍。与hHC不同，cHC的分泌不依赖于LC。与hLC相比，cLC使FVIII的比活性提高了两到三倍。此外，cLC而非cHC有助于提高cFVIII的稳定性。我们的结果表明，由于cHC的分泌效率高于hHC，且cLC表现出比hLC更活跃和稳定的表型，因此在犬类模型中cFVIII表达的结果应谨慎解读。
