Current status of retroviral vector mediated gene transfer into human hematopoietic stem cells

Genetic modification of hematopoietic stem cells (HSCs) has been proposed as a treatment strategy for a variety of hematologic diseases, tracking marked cells or conferring resistance to chemotherapeutic agents. Despite early enthusiasm, the results of clinical studies involving gene transfer into HSCs has not resulted in therapeutic benefits for the vast majority of treated patients. This review describes the limitations and advances that have been made in the areas of gene transfer vectors, identification of the appropriate HSCs to target for genetic modifications and the methods used to perform gene transfer.