Efficient Gene Transfer to Hematopoietic Repopulating Cells Using Concentrated RD114-Pseudotype Vectors Produced by Human Packaging Cells

The use of alternative viral envelope proteins to pseudotype oncoretroviral vectors has contributed substantially to recent improvements in retroviral gene transfer to hematopoietic stem cells. The envelope protein of endogenous feline leukemia virus (RD114) has emerged as a particularly attractive candidate in this context. Initial studies of RD114-pseudotype vectors produced by FLYRD18 packaging cells have shown promise, but it has also been demonstrated that FLYRD18 produces soluble factors that interfere with stem cell maintenance.