Gene transfer of alpha interferon into hematopoietic stem cells

Abstract

Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. IFN-α has been used in the management of leukemia, and gene transfer of the IFN-α gene into hematopoietic progenitor cells may have great potential for the treatment of chronic myelogenous leukemia (CML). Therefore, we examined the ability of adenovirus (Ad)-IFN-α gene construct to transfect normal bone marrow hematopoietic CD34 + stem cells and the production of IFN-α protein by these cells. Ad-cytomegalovirus (CMV) promoter-driven IFN-α at multiple doses was assessed to transfect highly purified CD34 + cells in liquid culture. Optimal transduction of CD34 + cells with the AdCMV-IFN-α construct was achieved using 120 plaque forming units (pfu). Flow cytometric determinations revealed that there was no significant difference in CD34 + cell viability for the 8 or 12-h transfection periods. Immunoassay of IFN-α produced by CD34 + cells shows that IFN-α levels increased several fold in transfected cells and this was not seen in CD34 + cells transfected with the heme oxygenase gene (HO-1). These in vitro data suggest that adenovirus-mediated gene transfer of IFN-α into hematopoietic stem cells can be achieved and that the IFN-α protein is produced by viable CD34 progenitor cells.