Augmentation of transgene expression in cold-preserved organs using vascular endothelial growth factor...

Adenovirus-mediated gene transfer has been widely used in gene therapy for congenital metabolic, cardiovascular, and malignant diseases. It has been reported that a gene transfer technique into transplanted organs may suppress rejection reactions and inhibit preservation injury. However, the magnitude of transgene expression in organs preserved at a cold temperature remains to be determined. In this study, we compared the transgene expression using vascular endothelial growth factor receptor (VEGFR)-mediated adenoviral vector at cold versus warm temperatures alone and combined with hyperbaric oxygen in cold-preserved organs. The transgene expression by porcine endothelial cells transduced with adenoviral vector was significantly higher after a 24 hour-incubation at warm temperature than after a 1 hour-incubation with warm or cold temperature. Moreover, the transgene expression of after a 1-hour incubation at cold temperature was significantly lower than a 1-hour incubation at warm temperature. The VEGFR-mediated adenoviral vector augmented transgene expression during a 1-hour incubation at cold temperature compared to the control vector. A/J skin graft survival in C3H mice was significantly prolonged compared to control or standard vector with CTLA4Ig cDNA using VEGFR-mediated adenoviral vector with CTLA4Ig cDNA in a 1-hour cold preservation. Furthermore, combined use of VEGFR-mediated adenoviral vector with CTLA4Ig cDNA plus FK506 showed an augmented effect on graft prolongation. It is concluded that adenovirus-mediated gene transfer in 1-hour cold-preserved organ is difficult compared to that in the warm condition. However, VEGFR-mediated gene transfer can augment the transgene expression in 1-hour cold-preserved organs, followed by the effective suppression of rejection reactions in allogeneic transplantation.