Uchida Naoya, Fujita Atsushi, Hsieh Matthew M, Bonifacino Aylin C, Krouse Allen E, Metzger Mark E, Donahue Robert E, Tisdale John F
1 Molecular and Clinical Hematology Branch, National Heart Lung and Blood Institutes/National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland, MD.
2 Hematology Branch, National Heart Lung and Blood Institutes/National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland, MD.
Hum Gene Ther Clin Dev. 2017 Sep;28(3):136-144. doi: 10.1089/humc.2017.029. Epub 2017 Apr 17.
Steady state bone marrow (BM) is the preferred hematopoietic stem cell (HSC) source for gene therapy in sickle cell disease (SCD) due to the recognized risk of vaso-occlusive crisis during granulocyte colony-stimulating factor mobilization. We previously established clinically relevant HSC gene transfer in the rhesus model following transplantation of mobilized peripheral blood (PB) CD34 cells transduced with lentiviral vectors. In this study, we examined steady state bone marrow (BM) in the rhesus competitive repopulation model and demonstrate similar gene marking in vitro and in vivo, as compared with mobilized PB CD34 cells. We then evaluated PB and steady state BM in subjects with SCD and observed a higher frequency of CD34 cells when compared with controls, likely due to enhanced hematopoiesis. However, CD34 cell counts were reduced in both the PB and BM in patients treated with hydroxyurea, and hydroxyurea treatment strongly inhibited iPS cell generation from SCD subjects. Our data support that steady state BM is a useful HSC source for SCD gene therapy with similar transduction. The lower CD34 percentages observed with hydroxyurea treatment warrants withholding hydroxyurea temporarily prior to harvesting HSCs. Our results are important for the design of gene targeting strategies for SCD.
由于在粒细胞集落刺激因子动员期间存在公认的血管闭塞性危机风险，稳态骨髓（BM）是镰状细胞病（SCD）基因治疗中首选的造血干细胞（HSC）来源。我们之前在用慢病毒载体转导的动员外周血（PB）CD34细胞移植后，在恒河猴模型中建立了临床相关的HSC基因转移。在本研究中，我们在恒河猴竞争性再增殖模型中检测了稳态骨髓（BM），并证明与动员的PB CD34细胞相比，在体外和体内具有相似的基因标记。然后我们评估了SCD患者的PB和稳态BM，发现与对照组相比，CD34细胞频率更高，这可能是由于造血增强所致。然而，接受羟基脲治疗的患者的PB和BM中的CD34细胞计数均降低，并且羟基脲治疗强烈抑制了SCD患者诱导多能干细胞的产生。我们的数据支持稳态BM是SCD基因治疗中具有相似转导作用的有用HSC来源。羟基脲治疗观察到的较低CD34百分比值得在收获HSCs之前暂时停用羟基脲。我们的结果对于SCD基因靶向策略的设计很重要。
