EX-VIVO GENE-THERAPY PREVENTS CHRONIC GRAFT VASCULAR-DISEASE IN CARDIAC ALLOGRAFTS

Objective: We hypothesized that ex vivo hyperbaric transfection of ant isense oligodeoxynucleotides for blockade of intercellular adhesion mo lecule-1, an important mediator of cell adhesion and T-cell costimulat ion, would reduce chronic graft vascular disease in cardiac allografts . Methods: PVG hearts underwent ex vivo transfection with antisense, r everse antisense intercellular adhesion molecule-1 oligodeoxynucleotid e (80 mu mol/L), or saline solution at 3 atm pressure for 45 minutes a t 4 degrees C and were transplanted heterotopically into ACI recipient s with or without treatment with intercellular adhesion molecule-1 (1A 29) or leukocyte function associated antigen-1 (WT.1) monoclonal antib odies. Transfection efficiency was confirmed with fluorescein isothioc yanate-labeled oligodeoxynucleotides and fluorescent microscopy, Effic acy of intracellular adhesion molecule-1 blockade was assessed with th e use of immunohistochemistry. Graft reperfusion injury was evaluated at 6 to 24 hours by neutrophil infiltration (myeloperoxidase [MPO]), c ardiac edema (%wt/wt), and histologic injury (percent contraction band necrosis), Grafts from recipients treated with cyclosporine A (5 mg/k g per day, days 0 to 9) were scored for chronic graft vascular disease on postoperative day 90 ranging from 0 (no involvement) to 4 (>50% va scular occlusion), Results: Transfection was highly efficient (fluores cein isothiocyanate-labeled oligodeoxynucleotides in 48% +/- 5% of tot al myocardial nuclei) and effective at blocking intracellular adhesion molecule-1 expression (positive area in allografts taken on postopera tive day 3 was reduced from 100% +/- 0% to 52% +/- 14%, n = 4), Blocka de with antisense oligodeoxynucleotides versus monoclonal antibodies w as less effective at preventing reperfusion injury while more effectiv e at reducing chronic graft vascular disease (score 0.98 +/- 0.48, p < 0.05). Reverse antisense oligodeoxynucleotides and vector control (an tisense oligodeoxynucleotide infusion without pressure) groups failed to demonstrate this beneficial effect, Conclusion: Hyperbaric transfec tion of antisense oligodeoxynucleotides proved highly efficient, effec tive at blockade of intracellular adhesion molecule-1, and demonstrate d a sequence-specific reduction in chronic graft vascular disease. Thi s highly targeted alteration of donor organ immunogenicity may have an important future role in clinical immunosuppressive strategies.