MESOTHELIAL CELL-MEDIATED GENE-THERAPY - FEASIBILITY OF AN EX-VIVO STRATEGY

We have developed a model system in the rat to test the feasibility of recombinant protein expression by genetically modified peritoneal mes othelial cells following autologous peritoneal implantation. Rat prima ry peritoneal mesothelial cells, isolated from parietal peritoneum by enzymatic digestion, were stably transduced (using a Moloney murine le ukemia virus (MoMLV)-derived retroviral vector, BAG, expressing the Es cherichia coil lacZ gene) to mark the cells with a reporter protein (b eta-galactosidase, beta-gal). Such transduced mesothelial cells, tagge d with DiO, a fluorescent lipophilic dye used for long-term tracing of transplanted cells, were then reseeded on the denuded peritoneal surf ace of syngeneic recipients. Dio-labeled, BAG-transduced mesothelial c ells were observed to repopulate the denuded areas and remain attached there for > 90 days. Moreover, these genetically modified mesothelial cells continued to express the reporter gene product in vivo (ie beta -gal activity was present for at least 1 month). Our result demonstrat e the feasibility of ex vivo gene therapy using peritoneal mesothelial cells.