2型腺相关病毒载体介导正常人β珠蛋白基因在重型地贫流产胎儿造血细胞中的表达

Adeno-associated Virus Type 2-mediated Expression of the Normal Human β-globin Gene in Hematopoietic Cells of the Aborted β-thalassemia Major Fetus

目的:探讨2型重组腺相关病毒(recombin antadeno-associated virus 2,rAAV2)载体介导人β-珠蛋白基因转染地贫患者造血细胞治疗β-地中海贫血的可行性。方法:分离β41-42/β654杂合子型重型β-地贫流产胎儿造血细胞,经rAAV2-β-globin病毒转染(MOI=50)后移植入经X射线照射的BALB/c裸小鼠体内,分别于移植后14d、21d处死受体小鼠,RT-PCR及等位基因特异性PCR法检测人珠蛋白基因在受体小鼠体内的表达。结果:RT-PCR方法于3只受体小鼠骨髓样本中成功检测到人β-actin和人β-珠蛋白基因的表达,而21d处死的转染与对照小鼠外周血样本中未检测到人β-珠蛋白基因表达;等位基因特异性PCR方法在所有受体鼠体内同时检测到β41-42和β654突变基因,以及正常β-珠蛋白基因的表达,但rAAV2-β-globin转染组小鼠体内正常人β-珠蛋白基因表达水平明显高于对照组。结论:rAAV2可有效转染β41-42/β654杂合子型重型地中海贫血患者造血细胞,并通过exvivo途径介导β-珠蛋白转基因的体内表达,提高红系细胞内正常β-珠蛋白基因的表达水平。

Objective：To investigate the potential feasibility of rAAV2-mediated human β-globin gene transfer into autologous hematopoietic cells in gene therapy for β-thalassemia.Methods：Isolated human hematopoietic cells from aborted β-thalassemia major fetus of β41-42/β654 heterozygote were transfected or mock-transfectedd with rAAV2-β-globin （MOI=50） and transplanted in to NOD/SCID nude mice pretreated with X-ray through tail intravenous injection （IV）.Expression of rAAV2-mediated normal β-globin gene was detected by RT-PCR and allele-specific PCR respectively in all recipient mice on 14d or 21d post-transplanted.Results：The ex-pression of human β-actin and β-globin gene was observed in bone marrow of all recipients by RT-PCR, but not in peripheral blood of recipients detected on 21d.By allele-specific PCR, the expression of β41-42, β654 and normal β-globin gene was found in all transduced and mock-transduced recipient mice, and the elevated expression of normal β-globin gene was confirmed in transduced recipi-ents.Conclusion：Recombinant AAV2 vectors could efficiently introduce and express the β-globin transgene in human hematopoietic cells from β-thalassemia fetus of β41-42/β654 heterozygote in vivo, and significantly elevate the expression of β-chains in human erythroid cells in peripheral blood.