Experiments were designed to evaluate the efficiency of antegrade compared to retrograde vascular gene transfection of donor lungs used for transplantation. Rat donor lungs (n = 5/group) were transduced with an adenoviral vector encoding for β-galactosidase (AdβGal), either antegrade in the pulmonary artery (Group A, 3 x 108 pfu, Group B, 3 x 109 pfu) or retrograde into the pulmonary vein (Group C, 3 x 108 pfu), immediately after pneumoplegia. After storage at 4°C for 1 h, the transduced lungs were transplanted orthotopically in syngeneic animals. The lungs were assessed for transgene expression by ELISA and X-Gal-staining at day 7 after operation. Inflammation was graded based on the extent of inflammatory cell infiltration. Transgene expression was similar between Groups A (1.7 ± 0.7 ng/mg protein) and B (2.1 ± 1.0 ng/mg protein). With retrograde delivery, there was a four-fold (8.3 ± 2.6 ng/mg protein) increase (P < 0.05) in transgene expression compared to either group A or B. In all groups, pneumocytes were transduced most frequently. The degree of inflammation correlated positively with the extent of transgene expression (r = 0.75, P < 0.01). The efficiency of vascular gene delivery to transplanted lungs can be improved by retrograde delivery of the vector via the pulmonary vein. Transgene expression predominates in pneumocytes following both antegrade and retrograde delivery. The severity of inflammation in the transplanted lung appears to correlate with the extent of transgene expression.
Bibliographical noteFunding Information:
Acknowledgements This work was supported by the Mayo Clinic and Foundation, Rochester, Minnesota and the Bruce and Ruth Rappaport Program in Vascular Biology. The skillful technical assistance from Sandra Severson and Sharon Guy is gratefully acknowledged. Dr. Anders Jeppsson was a visiting scientist supported by grants from Sahlgrenska University Hospital, University of Gothenburg, The Foundation for Medical Research and Education (SMFS), Assar Gabrielsson Foundation, Gunnar, Arvid and Elisabeth Nilsson Foundation, Swedish Medical Society, Swedish Medical Research Council and Gothenburg Medical Society.
- Gene transfer
- Lung transplantation