Ex vivo and in vivo transduction of human vessels. (A) Human saphenous veins were removed from patients undergoing coronary bypass surgery and transferred immediately into culture dishes. The vessels were transduced with huCD105-LV and cultivated for 7-10 days before fixation and immunofluorescent staining. Cells were stained for human CD105 (left column) or for GFP (middle column), or were merged to display colocalization (right column). Arrows point to the luminal side of the vessel. (B) Mammarian arteries from patients requiring coronary bypass surgery were transplanted intraabdominally into the descending aorta of NOD Rag2^−/−IL-2Rγc^null mice. HuCD105-LV (3 × 10⁷ transducing units) was injected into the tail vein of transplanted mice at 2, 5, and 8 days after transplantation, and mice were sacrificed after 16 days. The transplanted artery was cryosectioned and prepared for immunofluorescence staining. The pictures were acquired by detecting fluorescence at 4 adjacent locations along the luminal endothelial layer of the transduced graft. Raw picture data were obtained by acquiring fluorescence in the GFP, the DAPI, and the Cy5 channel. The channels were merged using the Olympus Cell^M image acquiring and processing software. To obtain an overview of the entire stretch of the transduced endothelium, we assembled 4 pictures using Adobe Photoshop software (Adobe Systems, San Jose, CA). Hangover areas were filled with black color to generate a high-contrast background. Noise was reduced by balancing color levels equally for assembled pictures. The staining revealed CD105-positive cells lined up facing the lumen (orange arrows, top left), which were also positive for GFP (green arrows, top right). Colocalization is depicted in the merge (bottom, green arrows). Representative pictures are from 1 mouse, 3 mice transplanted.