Distribution of Lentiviral Vector Integration Sites in Mice Following Therapeutic Gene Transfer to Treat β-thalassemia
| Autor: | Olivier Negre, Maria Denaro, Troy Brady, Frederic D. Bushman, Charlotte Colomb, Keshet Ronen, Shannah Roth, Beatrix Gillet-Legrand, Nirav Malani, Yves Beuzard, Emmanuel Payen, Philippe Leboulch, Julian D. Down, Kathleen M. Hehir, Floriane Fusil |
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| Rok vydání: | 2011 |
| Předmět: |
Genetic Vectors
Spleen Locus (genetics) beta-Globins Biology Somatic evolution in cancer Viral vector Mice 03 medical and health sciences Negative selection 0302 clinical medicine Drug Discovery Genetics medicine Animals Molecular Biology Gene Chromatography High Pressure Liquid Bone Marrow Transplantation 030304 developmental biology Pharmacology 0303 health sciences HMGA2 Protein Lentivirus beta-Thalassemia Flow Cytometry Molecular biology Transplantation medicine.anatomical_structure 030220 oncology & carcinogenesis Molecular Medicine Original Article Bone marrow |
| Zdroj: | Molecular Therapy. 19:1273-1286 |
| ISSN: | 1525-0016 |
| Popis: | A lentiviral vector encoding β-globin flanked by insulator elements has been used to treat β-thalassemia (β-Thal) successfully in one human subject. However, a clonal expansion was observed after integration in the HMGA2 locus, raising the question of how commonly lentiviral integration would be associated with possible insertional activation. Here, we report correcting β-Thal in a murine model using the same vector and a busulfan-conditioning regimen, allowing us to investigate efficacy and clonal evolution at 9.2 months after transplantation of bone marrow cells. The five gene-corrected recipient mice showed near normal levels of hemoglobin, reduced accumulation of reticulocytes, and normalization of spleen weights. Mapping of integration sites pretransplantation showed the expected favored integration in transcription units. The numbers of gene-corrected long-term repopulating cells deduced from the numbers of unique integrants indicated oligoclonal reconstitution. Clonal abundance was quantified using a Mu transposon-mediated method, indicating that clones with integration sites near growth-control genes were not enriched during growth. No integration sites involving HMGA2 were detected. Cells containing integration sites in genes became less common after prolonged growth, suggesting negative selection. Thus, β-Thal gene correction in mice can be achieved without expansion of cells harboring vectors integrated near genes involved in growth control. |
| Databáze: | OpenAIRE |
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