Abstract
β-Globin locus control region (LCR) sequences have been widely used for the regulated expression of the human β-globin gene in therapeutic viral vectors. In this study, we compare the expression of the human β-globin gene from either the HS2/HS3 β-globin LCR or the HS40 regulatory element from the α-globin locus in the context of foamy virus (FV) vectors for the genetic correction of β-thalassemia. Both regulatory elements expressed comparable levels of human β-globin in a murine erythroleukemic line, whereas in murine hematopoietic stem cells the HS40.β vector proved more efficient in β-globin expression and correction of the β-thalassemia phenotype. Following transplantation in the Hbb th3/+ mouse model, the expression efficiency by the two vectors was similar, whereas the HS40.β vector achieved relatively more stable transgene expression. In addition, in an ex vivo assay using CD34+ cells from thalassemic patients, both vectors achieved significant human β-globin expression and restoration of the thalassemic phenotype as evidenced by enhanced erythropoiesis and decreased apoptosis. Our data suggest that FV vectors with the α-globin HS40 element can be used as alternative but equally efficient vehicles for human β-globin gene expression for the genetic correction of β-thalassemia.
Original language | English (US) |
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Pages (from-to) | 303-311 |
Number of pages | 9 |
Journal | Gene therapy |
Volume | 19 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2012 |
Externally published | Yes |
Bibliographical note
Funding Information:We thank Dr G Stamatoyannopoulos, Q Li and D Emery from the University of Washington (Seattle, WA) for the HS40 plasmid; Dr N Anagnou for providing the Hbbth3/+ mice; and Drs E Gouseti, S Grafako and A Kattamis (Children’s Hospital, Agia Sofia, Athens, Greece) for providing b-thalassemia patient samples. The work was supported from an EU grant (CONSERT LSHB-CT-2004-005242) and a grant from the Greek GSRT (PENED 603).
Keywords
- HS40
- foamy virus
- thalassemia
- β-globin