Genetic marking and manipulation of hematopoietic progenitor cells using retroviral vectors

In the 5 years since the first human gene therapy studies began, more than 70 clinical protocols have been approved, and over 200 patients have received genetically modified cells. A high proportion of these protocols have made use of hematopoietic progenitor cells or their mature progeny. In this review, we discuss the progress and limitations of current clinical gene transfer studies using marrow-derived progenitor cells and describe how the technique is being applied to the treatment of single-gene disorders and to augment cancer immunotherapies. We also discuss the contribution made by gene marking studies.