Cryopreserved primate bone marrow cells can be used for retroviral-mediated gene transfer

Retroviral-mediated gene transfer into Rhesus monkey bone marrow cells, which were cryopreserved, stored, and then transduced at the time of thawing, was studied for potential application in gene therapy protocols. Albumin density gradient fractionation was used to define subpopulations of cryopreserved cells transduced by a murine retroviral vector. The transfer of the bacterial neomycin phosphotransferase gene into Rhesus monkey bone marrow that was cryopreserved and thawed was found to be preferential in a light-density population enriched for granulocyte-macrophage colony-forming units (CFU-GM). These results are similar to results obtained with freshly harvested bone marrow in which this population is enriched for CD34 antigen-positive cells, as well as for cells that were undergoing cell division. This method may be useful in enriching for transduced precursors in future gene transfer experiments in primates.