DEVELOPMENT OF A HIGH-TITER RETROVIRUS PRODUCER CELL-LINE CAPABLE OF GENE-TRANSFER INTO RHESUS-MONKEY HEMATOPOIETIC STEM-CELLS

Retroviral-mediated gene transfer into primitive hematopoietic cells has been difficult to achieve in large-animal models. We have developed an amphotropic producer clone that generates > 1010 recombinant retroviral particles (colony-forming units) per ml of culture medium. Autologous rhesus monkey boe-marrow cells were cocultured with either high (2 x 1010 colony-forming units/ml) or low (5 x 106 colony-forming units/ml) titer producer clones for 4-6 days and reinfused into sublethally irradiated animals. The proviral genome was detected in blood and bone-marrow from all three animals reconstituted with cells cocultured with the high-titer producer cells. In contrast, three animals reconstituted with bone marrow cocultured with the low-titer producer clone exhibited no evidence of gene transfer.