Fetal gene therapy of alpha-thalassemia in a mouse model.
Fetuses with homozygous alpha-thalassemia usually die at the third trimester of pregnancy or soon after birth. Hence, the disease could potentially be a target for fetal gene therapy. We have previously established a mouse model of alpha-thalassemia. These mice mimic the human alpha-thalassemic conditions and can be used as preclinical models for fetal gene therapy. We tested a lentiviral vector containing the HS 2, 3, and 4 of the beta-LCR, a central polypurine tract element, and the beta-globin gene promoter directing either the EGFP or the human alpha-globin gene. We showed that the GFP expression was erythroid-specific and detected in BFU-E colonies and the erythroid progenies of CFU-GEMM. For in utero gene delivery, we did yolk sac vessel injection at midgestation of mouse embryos. The recipient mice were analyzed after birth for human alpha-globin gene expression. In the newborn, human alpha-globin gene expression was detected in the liver, spleen, and peripheral blood. The human alpha-globin gene expression was at the peak at 3-4 months, when it reached 20% in some recipients. However, the expression declined at 7 months. Colony-forming assays in these mice showed low abundance of the transduced human alpha-globin gene in their BFU-E and CFU-GEMM and the lack of its transcript. Thus, lentiviral vectors can be an effective vehicle for delivering the human alpha-globin gene into erythroid cells in utero, but, in the mouse model, delivery at late midgestation could not transduce hematopoietic stem cells adequately to sustain gene expression.
Han
Xiao-Dong
XD
Cardiovascular Research Institute, Institute of Human Genetics and Department of Medicine, University of California, San Francisco, CA 94143, USA.
Lin
Chin
C
Chang
Judy
J
Sadelain
Michel
M
Kan
Y W
YW
D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D004622:Embryo, Mammalian / Q000196:embryology / Q000378:metabolism; D041905:Erythroid Cells / Q000378:metabolism; D005260:Female; D046128:Fetal Therapies; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D018014:Gene Transfer Techniques; D017930:Genes, Reporter / Q000235:genetics; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D008297:Male; D051379:Mice; D023421:Models, Animal; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics; D013997:Time Factors; D019076:Transgenes / Q000235:genetics; D015017:Yolk Sac / Q000098:blood supply / Q000378:metabolism; D017085:alpha-Thalassemia / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger