Townes Tim M
Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, School of Medicine, Birmingham, AL 35294, USA.
Hematology Am Soc Hematol Educ Program. 2008:193-6. doi: 10.1182/asheducation-2008.1.193.
Previous studies have demonstrated that sickle cell disease (SCD) can be corrected in mouse models by transduction of hematopoietic stem cells with lentiviral vectors containing anti-sickling globin genes followed by transplantation of these cells into syngeneic recipients. Although self-inactivating (SIN) lentiviral vectors with or without insulator elements should provide a safe and effective treatment in humans, some concerns about insertional mutagenesis persist. An ideal correction would involve replacement of the sickle globin gene (betaS) with a normal copy of the gene (betaA). We recently derived embryonic stem (ES) cells from a novel knockin mouse model of SCD and tested a protocol for correcting the sickle mutation by homologous recombination. Animals derived after gene replacement produced high levels of normal human hemoglobin (HbA), and the pathology associated with SCD was corrected. These experiments provided a foundation for similar studies in which our group collaborated with Rudolf Jaenisch's laboratory to correct SCD by gene replacement in iPS (induced pluripotent stem) cells derived by direct reprogramming of sickle skin fibroblasts. Corrected iPS cells were differentiated into hematopoeitic progenitors that were transplanted into irradiated sickle recipients. The transplanted animals produced high levels of normal human HbA, and the pathology of SCD was corrected. These proof-of-principle studies provide a foundation for the development of gene replacement therapy for human patients with SCD and other blood disorders.
先前的研究表明，在小鼠模型中，通过用含有抗镰状化珠蛋白基因的慢病毒载体转导造血干细胞，然后将这些细胞移植到同基因受体中，可以纠正镰状细胞病（SCD）。尽管带有或不带有绝缘子元件的自我失活（SIN）慢病毒载体应该能为人类提供一种安全有效的治疗方法，但对插入诱变的一些担忧依然存在。理想的纠正方法是用该基因的正常拷贝（βA）替换镰状珠蛋白基因（βS）。我们最近从一种新型的SCD基因敲入小鼠模型中获得了胚胎干细胞（ES），并测试了一种通过同源重组纠正镰状突变的方案。基因替换后产生的动物产生了高水平的正常人血红蛋白（HbA），与SCD相关的病理状态得到了纠正。这些实验为类似的研究奠定了基础，在这些研究中，我们小组与鲁道夫·雅尼施的实验室合作，通过对镰状皮肤成纤维细胞直接重编程衍生的诱导多能干细胞（iPS）进行基因替换来纠正SCD。经过纠正的iPS细胞分化为造血祖细胞，并移植到经辐射的镰状细胞受体中。移植后的动物产生了高水平的正常人HbA，SCD的病理状态得到了纠正。这些原理验证研究为开发针对人类SCD患者和其他血液疾病的基因替换疗法奠定了基础。
