Antigen-presenting properties of human vascular endothelial cells: inhibition by anti-HLA-DR antisera.

Human vascular endothelial cells (EC) separated from the umbilical vein are capable of presenting antigen to in-vivo-sensitized T cells, leading to an immunoproliferative response to various antigens in vitro. Optimal T-cell response was only observed when the EC donor shared both HLA-D/DR determinants with the T-cell donor. The T-cell response normally observed when using antigen-pulsed EC was significantly and specifically inhibited by xeno- and allo-antisera reacting with the HLA-DR molecules. Moreover, antibodies reacting with the native antigen determinats (rubella virus) also appeared capable of inhibiting the response elicited by primed T cells to antigen-pulsed EC.