ALLOANTIGENICITY OF HUMAN ENDOTHELIAL-CELLS .4. DERIVATION, CHARACTERIZATION, AND UTILIZATION OF GONADAL VEIN ENDOTHELIA TO CONTROL ENDOTHELIAL ALLOANTIGENICITY DURING LYMPHOCYTE-ENDOTHELIAL INTERACTIONS

Most previous studies to evaluate endothelial cell-T lymphocyte intera ctions have used human peripheral blood as a source of T lymphocytes a nd human umbilical vein endothelial cells as a source of endothelia. I mplicit in this experimental system are allogeneic lymphocyte endothel ial interactions, which are largely ignored. To overcome this problem, we isolated gonadal vein endothelial cells (GVEC) along with matched splenic macrophages and T lymphocytes from cadaveric donors, thus prov iding a completely autologous series of cells for experimentation. Fir st, GVEC were analyzed for morphology, surface phenotype, and cytokine mRNA expression, and found to be indistinguishable from human umbilic al vein endothelial cells. Using this system, we observed that irradia ted GVEC were able to promote a 2- to 8-fold increase in the prolifera tion of matched autologous splenic T cells after PHA stimulation. This indicates that the costimulator activity of endothelial cells reporte d by others is an intrinsic property of endothelial cells, and is not a consequence of endothelial alloantigens. We also used this system to assess the relative abilities of GVEC and macrophages obtained from t he same donor to stimulate the proliferation of purified allogeneic CD 3(+) PBL. We found the following hierarchy of alloantigenicity in this experimental system: splenic macrophages > IFN-gamma-treated GVEC muc h greater than untreated GVEC = TNF alpha-treated GVEC. These studies demonstrate that allogeneic macrophages are intrinsically more antigen ic than endothelial cells derived from the same donor. Furthermore, th ey illustrate the utility of this experimental system to obtain data r egarding lymphocyte-endothelial interactions that are otherwise unobta inable.