Springer Protocols: Abstract: 12. Reducing the Genotoxic Potential of Retroviral Vectors

12. Reducing the Genotoxic Potential of Retroviral Vectors

By: Ali Ramezani³, Teresa S. Hawley⁴, Robert G. Hawley³

Abstract

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The recent development of leukemia in gene therapy patients with X-linked severe combined immunodeficiency disease because of retroviral vector insertional mutagenesis has prompted reassessment of the genotoxic potential of integrating vector systems. In this chapter, various strategies are described to reduce the associated risks of retroviral genomic integration. These include deletion of strong transcriptional enhancer-promoter elements in the retroviral long terminal repeats, flanking the retroviral transcriptional unit with enhancer blocking sequences and designing vectors with improved RNA $3^{\prime}$ end processing. Protocols are provided to evaluate the relative biosafety of the modified vectors based on their ability to immortalize hematopoietic progenitor cells and propensity to trigger clonal hematopoiesis or leukemogenesis following hematopoietic stem cell transplantation.

Affiliation(s): (3) Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC
(4) Flow Cytometry Core Facility, The George Washington, University Medical Center, Washington, DC

Book Title: Gene Therapy Protocols: Design and Characterization of Gene Transfer Vectors

Series: Methods in Molecular Biology | Volume: 434 | Pub. Date: Mar-07-2008 | Page Range: 183-203 | DOI: 10.1007/978-1-60327-248-3_12

Subject: Genetics/Genomics

Key Words: Gammaretroviral vectors - lentiviral vectors - insertional mutagenesis - genotoxicity - self-inactivating vectors - enhancer blocking sequences - post-transcriptional regulatory elements - RNA $3^{\prime}$ end processing

References

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