Reduction of monocyte adhesion to xenogenic tissue by endothelialization: an adhesion molecule and time-dependent...

Great interest has been shown for the seeding of autologous endothelial cells on prosthetic materials. We investigated the inflammatory and immunogenic properties of xenogeneic tissue before and after seeding with cultured human great saphenous vein endothelial cells in vitro. Adhesion of monocytes to xenogeneic tissue with or without endothelium and the endothelial cell expression of E-selectin, intercellular adhesion molecule 1, vascular adhesion molecule 1, and major histocompatibility complex class II antigens were investigated 1, 3, and 7 days after seeding. Both monocyte adhesion and endothelial adhesion molecule expression were relatively high 1 day after seeding and were significantly lowered after 3 to 7 days. There was no difference between monocyte adhesion and adhesion molecule expression on viable or nonviable xenogeneic tissue. Monocyte adhesion and adhesion molecule expression increased after interleukin-1 beta or interferon-gamma stimulation of the endothelial cells. The results suggest that human endothelial cells exhibit an early proinflammatory and immunogenic activity immediately after seeding. Three and 7 days after seeding, the endothelialized surface is less adhesive for monocytes as compared with nonendothelialized tissue. These findings have implications when cultured or intraoperatively recruited endothelial cells are used clinically.