Extended β-globin locus control region elements promote consistent therapeutic expression of a γ-globin lentiviral vector in murine β-thalassemia
Extended β-globin locus control region elements promote consistent therapeutic expression of a γ-globin lentiviral vector in murine β-thalassemia
复制标题
DOI：
10.1182/blood-2004-03-0863
复制
发表时间：
2004-10-15
期刊：
影响因子：
20.3
通讯作者：
Persons, DA
中科院分区：
文献类型：
--
作者：
Hanawa, H;Hargrove, PW;Persons, DA
由于增加的胎儿血红蛋白降低β-地中海贫血和镰状细胞贫血的严重程度，使用自体干细胞靶向基因转移γ-珠蛋白基因的策略可能在治疗上有用。我们以前发现，γ-珠蛋白慢病毒载体利用β-珠蛋白启动子和β-珠蛋白基因座控制区（LCR）的元素，共1.7 kb可以纠正小鼠β-地中海贫血。然而，治疗的一致性受到染色体位置对载体表达的影响。相比之下，我们在此表明，接受用含有3.2 kb LCR序列的新载体转导的β-地中海贫血干细胞移植的大多数动物表达高水平的胎儿血红蛋白（17%-33%），平均载体拷贝数为1.3。这导致血红蛋白浓度平均增加26 g/L（2.6 g/dL），其他血液学参数改善增强。对接受移植的小鼠的次级脾集落的克隆红系细胞的分析表明，较大的LCR载体对稳定和多变的位置效应的抗性增加。对于位于基因内部的载体插入位点也观察到这种趋势，其中载体表达通常受到损害，与基因间位点相反，在基因间位点观察到更高水平的表达。这些数据强调了克服不利位置效应对于一致的治疗性珠蛋白载体表达的重要性。(C)2004年，美国血液学会。
Since increased fetal hemoglobin diminishes the severity of beta-thalassemia and sickle cell anemia, a strategy using autologous, stem cell-targeted gene transfer of a gamma-globin gene may be therapeutically useful. We previously found that a gamma-globin lentiviral vector utilizing the beta-globin promoter and elements from the beta-globin locus control region (LCR) totaling 1.7 kb could correct murine beta-thalassemia. However, therapeutic consistency was compromised by chromosomal position effects on vector expression. In contrast, we show here that the majority of animals that received transplants of beta-thalassemic stem cells transduced with a new vector containing 3.2 kb of LCR sequences expressed high levels of fetal hemoglobin (17%-33%), with an average vector copy number of 1.3. This led to a mean 26 g/L (2.6 g/dL) increase in hemoglobin concentration and enhanced amelioration of other hematologic parameters. Analysis-of clonal erythroid cells of secondary spleen colonies from mice that underwent transplantation demonstrated an increased resistance of the larger LCR vector to stable and variegating position effects. This trend was also observed for vector insertion sites located inside genes, where vector expression was often compromised, in contrast to intergenic sites, where higher levels of expression were observed. These data emphasize the importance of overcoming detrimental position effects for consistent therapeutic globin vector expression. (C) 2004 by The American Society of Hematology.