Adenosine deaminase-transduced hematopoietic stem cells (National Human Genome Research Institute )

CD34+ cells were enriched using Isolex 300i. CD34+ cells were placed in culture with flt3 ligand (300 ng/mL), stem cell factor (50 ng/mL), and MGDF (50 ng/mL). After 2 days of prestimulation, half the cells were transduced with the GCsap-M-ADA vector and half were transduced with the MND-ADA vector. Each vector included the identical ADA cDNA but slightly different vector backbones.