Gene Transfer to Vein Graft Wall by HVJ-Liposome Method: Time Course and Localization of Gene Expression

Abstract Background . A novel gene transfer method using liposomes with a viral envelope of hemagglutinating virus of Japan (HVJ) has been reported to be very effective for gene transfection into somatic cells and might be applicable to improve the patency of vein grafts. The present study examined the time course and localization of gene expression to assess the feasibility of ex vivo gene transfer into the vein graft by the HVJ–liposome method. Methods . The HVJ–liposome complex containing either β-galactosidase plasmid DNA (deoxyribonucleic acid) or no genes (controls) (experiment 1) or fluorescein isothiocyanate–labeled oligonucleotides either with or without HVJ-liposomes (experiment 2) was infused into rabbit vein grafts and allowed to incubate before autologous transplantation to carotid arteries. Results . In experiment 1, all grafts incubated with β-galactosidase plasmid with HVJ-liposomes showed the blue staining of X-gal 7 days after operation, whereas the controls did not. The blue granules were present in the medial and adventitial tissue and were still present after 14 days. In experiment 2, many fluorescein isothiocyanate–labeled nuclei were observed in the graft wall 2 and 4 days after operation and remained present mainly in the media of HVJ-liposome–treated grafts after 7 and 14 days, when no fluorescein isothiocyanate activity was observed without HVJ–liposome treatment. Conclusions . These results demonstrated the feasibility of ex vivo transfection to the medial and adventitial tissue of the vein graft by the HVJ–liposome method and suggest the possibility of its clinical application to prevent vein graft failure.