Efficient and persistent expression of beta-glucuronidase gene in CD34+ cells from human umbilical cord blood by retroviral vector.

We succeeded in efficiently transferring the beta-glucuronidase gene in a retroviral vector to human hematopoietic progenitor cells using a centrifugation enhancement protocol. The transduction efficiency in CFU-GM was highly variable (23-100%) with an average of 66.8%. In the case of BFU-E, efficiency was 83% and 76% in 2 separate experiments. In LTCIC (long-term culture-initiating cell), transduction efficiency were 20% and 50% in 2 experiments. The enzymatic activity of beta-glucuronidase in transduced cells were increased above the control level up to 5 wk. Considering that correction of the enzyme deficiency in a small number of hematopoietic cells can be therapeutic for the Sly disease mouse, our data provide encouragement that human trials of gene therapy based on transferring beta-glucuronidase gene to hematopoietic cells may be efficacious.