ADENOVIRUS-MEDIATED GENE-TRANSFER IN THE TRANSPLANT SETTING .1. CONDITIONS FOR EXPRESSION OF TRANSFERRED GENES IN COLD-PRESERVED HEPATOCYTES

Transplantation of genetically modified hepatocytes has been suggested as a therapeutic modality for impaired hepatocellular function. This study examined adenoviral mediated gene transfer to isolated hepatocyt es, under conditions mimicking clinical transplant preservation. Isola ted rat hepatocytes were infected using replication-defective adenovir al vectors with an expression cassette containing the beta-galactosida se gene driven by a CMV promoter. Hepatocytes were infected in suspens ion immediately after isolation, then either cultured or transplanted immediately into a syngeneic host. Gene transfer efficiency was assess ed by histochemical staining and FAGS analysis for the gene product. T he presence of viral DNA and mRNA, as well as viral-derived protein pr oduction, were assayed. Efficiency of gene transfer was examined as a function of several preservation conditions. Infection efficiency was best in cells preserved in UW solution, correlated directly with virus :hepatocyte ratio and with length of exposure to virus. Successful inf ection resulted in significant viral-derived protein production, persi sting for at least two weeks in culture. These results demonstrate the versatility of adenoviral vectors in accomplishing rapid and efficien t gene transfer into nondividing hepatocytes during cold preservation. Such genetically modified hepatocytes have potential use for immediat e transplantation, without the need for further manipulation.