Genetic Manipulation of Hematopoietic Stem Cells

The development of recombinant DNA technology and gene delivery systems has made possible the genetic manipulation of hematopoietic cells. Use of this technology in transplantation medicine is being increasingly felt both in diagnostic and therapeutic applications. The fact that a relatively small number of hematopoietic stem cells normally supports an individual’s blood cell production through an entire lifespan has made these cells attractive targets for gene manipulation. Genetic modification of stem cells, may confer on all of their mature blood cell progeny, and for extended periods of time, the desired therapeutic genetic alteration. Thus, if an individual is deficient in a given gene product, and the defective gene has been cloned, then transduction and expression of a normal copy in reinfused hematopoietic cells of this individual might allow for correction of the defect. If the gene product can reach all sites in the patient where it is required, for example through normal vascular access of blood, such a manipulation should correct the gene deficiency and result in clinical benefit to the patient.