Current Gene Therapy

Ignacio Anegon
Director INSERM UMR 1064-Center for Research in Transplantation and Immunology
CHU de Nantes. 30, boulevard
Nantes
France

Back

Safety Concerns Related to Hematopoietic Stem Cell Gene Transfer Using Retroviral Vectors

Author(s): Peter Haviernik, Kevin D. Bunting.

Abstract:

Endogenous retroviruses have developed efficient methods during their life cycle for stable integration into the host genome. Because of this ability, retroviral vectors were designed with the goal of gene transfer into hematopoietic stem cells (HSCs). The ability to genetically modify HSCs provides a vehicle for durable expression of potentially therapeutic transgenes in all lineages of mature blood cells for the lifetime of the patient. Combined with bone marrow transplant, retroviral gene transfer has many potential applications for a wide range of blood diseases. Advances in the development of oncoretroviral vectors based on murine leukemia viruses (MLV) and more recent development of human immunodeficiency virus (HIV)-based vectors have greatly increased the gene transfer efficiency. Optimization of methods for gene transfer using MLV-based vectors has substantially improved marking levels in mice, with lower levels in large animals and in human clinical trials. With advances in gene transfer technology has also come renewed concern about insertional mutagenesis and activation of oncogenes. Advanced techniques for integration site analysis combined with sequence comparison using mouse and human genome databases has now made it possible to begin to understand the spectrum of possible integration sites for both MLV- and HIV-based vectors. Furthermore, other studies have shown positive and negative dosage-dependent effects of transgene expression in mouse and human cells. Therefore, vector design and safety testing are at the forefront of the field of gene therapy and this review discusses recent developments.

Keywords: hematopoietic stem cell, retroviral vector, gene therapy, replication-competent retrovirus, insertional mutagenesis

Order Reprints Order Eprints Rights & PermissionsPrintExport

Article Details

VOLUME: 4
ISSUE: 3
Year: 2004
Page: [263 - 276]
Pages: 14
DOI: 10.2174/1566523043346174
Price: $58