ABSTRACT
The attraction of marrow progenitor cells as targets for gene therapy is that they are easily accessible, they can be readily manipulated ex vivo and, in principle, successful transfer into a single self-renewing stem cell is sufficient to repopulate an entire patient with modified cells. Gene marking of clonogenic malignant cells in bone marrow can readily be demonstrated ex vivo. Gene expression was also detected in normal progenitor cells. The marker gene was also present and expressed in the mature progeny of these progenitor cells for 18 months or longer. One of the major concerns about any use of long-lived marrow progenitor cells for retrovirus-mediated gene transfer or therapy is that insertional mutagenesis would occur. Retrovirus-mediated gene transfer may be increased in efficiency by coculture of the target cells with the vector producer line rather than with the supernatant derived therefrom.
