Transduction of CD34+ enriched cord blood and Gaucher bone marrow cells by a retroviral vector carrying the glucocerebrosidase gene

One promising strategy for gene therapy of Gaucher disease involves ex vivo retroviral transduction of autologous hematopoietic stem cells. Studies in small animals have demonstrated that this approach provides a life-long supply of the glucocerebrosidase (GC) enzyme. Human application has developed to the stage of a clinical trial. In this study, we describe development of a high titer amphotropic producer line for the vector, MFG-GC, and explore transduction of CD34+ cells from various human sources. Higher than three times the normal levels of glucocerebrosidase activity in non-transduced cells were achieved following transduction of CD34+ cells obtained from bone marrow or cord blood from normal donors. The improvement in enzyme activity in Gaucher marrow was about 40-fold above deficient levels. We examined the timing and stepwise effect of multiple rounds of infection and evaluated post-infection expansion of cells in two different cytokine mixtures. Transduction efficiency was determined using immunocytochemistry and Southern blot hybridization.