TRANSDUCTION OF MOBILIZED PERIPHERAL-BLOOD CD34+ CELLS WITH THE GLUCOCEREBROSIDASE CDNA

Gaucher disease (GD), the most common human lysosomal storage disorder, results from a genetic deficiency of the enzyme glucocerebrosidase (GC). The cloning of human GC cDNA, the benefits of allogeneic bone marrow transplantation and the success of enzyme replacement therapy support the feasibility of gene therapy as an approach to a cure for GD. We report the transfer of the GC gene to mobilized human peripheral blood (PB) CD34+ cells obtained from patients primed with granulocyte colony-stimulating factor and/or chemotherapy. A tenfold enrichment of CD34+ cells was achieved using an avidin-biotin immunoadsorption technique. Prestimulation of the CD34+ cells with cytokines, followed by infection for 5 days with a supernatant containing the MFG-GC retroviral vector, resulted in enzyme activity up to 2.5-times greater than non-infected and lac-Z infected controls. Southern blot hybridization of DNA from these cells demonstrated a transduction efficiency of 10-30%. These studies show that the GC gene is transferred efficiently to mobilized PB CD34+ cells by the MFG-GC retroviral vector and results in expression of enzyme activity in the population of cells capable of bone marrow reconstitution. These results advance the development of gene therapy for GD.