ABSTRACT
Genetically modified stem and progenitor cells have been shown to be potentially useful
tools for cell therapy. They can be modified to express a transgene of interest and they
offer the possibility of transgene expression at the site where the stem cells are grafted.
This has been achieved either by direct administration in tissues or after systemic
injection of the modified stem cells. More importantly, because of their ability to
differentiate into various cell lineages, they offer the additional potential of repairing and
regenerating tissues in response to disease or injury. Mesenchymal stem cells (MSCs)
represent some of the most promising stem cells. They are easily available from the bone
marrow, need relatively simple requirements for in vitro expansion, self-renew at high
proliferation rate, and can be easily transduced with stable long-term gene transfer
expression, properties that make them easier to use than hematopoietic stem cells.
Genetically, MSCs can repair damaged tissues (1-3). They also have per se potential
therapeutic effects as was shown for the degradation of the extracellular matrix in
experimental models of fibrosis (4,5) or the facilitation of the grafting of transplanted
bone marrow progenitor cells by providing a competent stroma (6). They have a well-
established ability to differentiate into the mesoderm lineage, which makes them
potentially useful in strategies aiming at targeting the kidney mesangium for instance.
