Transtracheal gene transfection of donor lungs prior to organ procurement increases transgene levels at reperfusion and following transplantation

Background: Gene therapy’s potential to modify donor organs to better withstand the process of transplantation has yet to be realized. To determine whether gene transfection is feasible to treat the early post-transplant injury of ischemia–reperfusion, we compared transfection of lungs in the donor prior to organ procurement with transfection of harvested ex vivo lungs in a rat single lung transplant model. Lewis rats (donor transfection [DT]; n = 4) underwent transtracheal adenoviral-mediated transfection with 10 9 plaque forming unit of the β-galactosidase reporter gene. Donor lungs were harvested following 6 hours of in vivo post-transfection ventilation, and then preserved for 6 hours at 4° C prior to left single-lung transplantation. Ex vivo transfection was performed following organ retrieval; lungs were then preserved at 4° C for 6 hours (EVT6h; n = 6) and 12 hours (EVT12h; n = 6) prior to transplantation. Lung transgene expression was measured by chemiluminescence at reperfusion, and at 2 hours following lung transplantation. Donor transfection lungs showed significantly higher levels of transgene expression as compared with EVT lungs at the time of reperfusion (DT = 3,408 ± 1,301 relative light units/mg protein; EVT6h = 218 ± 7; EVT12h = 213 ± 26; p < 0.02) and at 2 hours after lung transplantation (DT = 2900 ± 870; EVT6h = 62 ± 27; EVT12h = 123 ± 21; p < 0.005). Transgene expression measured in the heart, liver, kidney, and serum from DT rats demonstrated virtually no evidence of collateral transfection at 12 hours post-transfection (all