Background: Current methods of in vivo gene transfer into myocardium are limited by low efficiency. To improve in vivo gene transfer, a gene transfer method using hemagglutinating virus of Japan (HVJ) as a viral vector can be an alternative.
Methods and results: In vivo gene transfection of FITC-labeled oligonucleotide (F-ODN) and cDNA of beta-galactosidase (beta-gal) was examined with use of the HVJ liposome (H group) or without it (C group). In the H group, F-ODN or cDNA of beta-gal were complexed with liposomes, DNA binding nuclear protein (HMG1), and the viral protein coat of HVJ. After the harvest of donor rat hearts arrested by cardioplegia, the coronary artery was infused with the liposome gene complex. The hearts were transplanted into the abdomens of recipient rats and harvested 3 days after transplantation. Regarding F-ODN, the H group clearly showed FITC staining in the nuclei of the myocytes and endothelial cells in almost all layers of the myocardium as compared with the C group. Regarding the expression of beta-gal, the H group showed a clear expression of beta-gal on myocytes, whereas very low expression of beta-gal was seen in the C group.
Conclusions: The donor hearts were transfected with F-ODN and beta-gal gene in almost all layers of the myocardium as a result of coronary infusion of the HVJ liposome during cardioplegic arrest. Our method is seen as a novel in vivo gene transfer technique for the heart and may provide a new tool for both research and therapy of heart transplantation.