Optimization of recombinant adeno-associated viral vectors for human beta-globin gene transfer and transgene expression.
Therapeutic levels of expression of the beta-globin gene have been difficult to achieve with conventional retroviral vectors without the inclusion of DNase I-hypersensitive site (HS2, HS3, and HS4) enhancer elements. We generated recombinant adeno-associated viral (AAV) vectors carrying an antisickling human beta-globin gene under the control of either the beta-globin gene promoter/enhancer or the erythroid cell-specific human parvovirus B19 promoter at map unit 6 (B19p6) without any enhancer, and tested their efficacy in a human erythroid cell line (K-562) and in primary murine hematopoietic progenitor cells (c-kit(+)lin()). We report here that (1) self-complementary AAV serotype 2 (scAAV2)-beta-globin vectors containing only the HS2 enhancer are more efficient than single-stranded AAV (ssAAV2)-beta-globin vectors containing the HS2+HS3+HS4 enhancers; (2) scAAV2-beta-globin vectors recombine with scAAV2-HS2+HS3+HS4 vectors after dual-vector transduction, leading to transgene expression; (3) scAAV2-beta-globin as well as scAAV1-beta-globin vectors containing the B19p6 promoter without the HS2 enhancer element are more efficient than their counterparts containing the HS2 enhancer/beta-globin promoter; and (4) scAAV2-B19p6-beta-globin vectors in K-562 cells, and scAAV1-B19p6-beta-globin vectors in murine c-kit(+)lin() cells, yield efficient expression of the beta-globin protein. Thus, the combined use of scAAV vectors and the parvovirus B19 promoter may lead to expression of therapeutic levels the beta-globin gene in human erythroid cells, which has implications in the use of these vectors in gene therapy of beta-thalassemia and sickle cell disease.
Maina
Njeri
N
Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.
Zhong
Li
L
Li
Xiaomiao
X
Zhao
Weihong
W
Han
Zongchao
Z
Bischof
Daniela
D
Aslanidi
George
G
Zolotukhin
Sergei
S
Weigel-Van Aken
Kirsten A
KA
Rivers
Angela E
AE
Slayton
William B
WB
Yoder
Mervin C
MC
Srivastava
Arun
A
D000818:Animals; D002460:Cell Line; D000229:Dependovirus / Q000235:genetics*; D004742:Enhancer Elements, Genetic / Q000235:genetics; D015870:Gene Expression; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics*; D005914:Globins / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D051379:Mice; D016732:Parvovirus B19, Human; D011401:Promoter Regions, Genetic / Q000235:genetics; D014161:Transduction, Genetic; D019076:Transgenes / Q000235:genetics*
D005914:Globins