Efficient adenoviral gene transfer to early venous bypass grafts: comparison with native vessels.
OBJECTIVE
Gene therapy may provide new approaches to reduce vein graft failure following coronary or peripheral bypass surgery. The aim of this study was to investigate the relative efficacy of intraoperative adenoviral gene transfer to vein grafts, comparing transgene expression in vein grafts with that in matched native vessels in the same animal. In addition, we assessed the impact of bypass grafting on the cellular targets of gene transfer.


METHODS
New Zealand White rabbits underwent interposition bypass grafting of the carotid artery, using the ipsilateral external jugular vein, which was infected with an adenovirus expressing beta-galactosidase immediately prior to bypass grafting (n = 16). The contralateral native jugular vein (n = 16) and carotid artery (n = 8) were infected concurrently with the same adenoviral preparation. After 3, 7 or 14 days, beta-galactosidase protein expression was quantified by ELISA, and specific cell types expressing beta-galactosidase were identified by X-Gal staining and by immunohistochemistry.


RESULTS
After 3 days, endothelial cells were efficiently transduced in all vessels; medial smooth muscle cells were transduced infrequently. In contrast to jugular veins after gene transfer, endothelium in vein grafts showed expression of VCAM-1 and ICAM-1, and intense inflammation with CD18+ leukocytes. Transgene expression in vein grafts at day 3 was maintained at levels approximately 50% of that in ungrafted jugular veins, but continued to decrease through day 7.


CONCLUSIONS
Although vascular injury in early venous bypass grafts reduces gene transfer efficacy, significant transgene expression is maintained for at least 7 days. These findings have important implications for intraoperative gene transfer strategies in vein grafts.
Channon
K M
KM
Department of Medicine, Duke University Medical Center, Box 3060, Durham, NC 27710, USA.
Fulton
G J
GJ
Gray
J L
JL
Annex
B H
BH
Shetty
G A
GA
Blazing
M A
MA
Peters
K G
KG
Hagen
P O
PO
George
S E
SE
D000256:Adenoviridae; D000818:Animals; D016893:Carotid Stenosis / Q000628:therapy*; D004730:Endothelium, Vascular / Q000201:enzymology; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D007150:Immunohistochemistry; D007601:Jugular Veins / Q000637:transplantation*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D011817:Rabbits; D013997:Time Factors; D001616:beta-Galactosidase / Q000235:genetics
D001616:beta-Galactosidase