Monoclonal antibodies to E92, an endothelial cell surface antigen.

Abstract

Two hybridoma-derived monoclonal antibodies have been developed that react with an antigen of molecular weight 92,000 daltons on the surface of human endothelial cells. Cultured human umbilical vein endothelial cells were used for immunization, but the antigen is present on arterial, venous and capillary endothelium, as determined by biotin-avidin immunoperoxidase staining of tissue sections. With this technique, other cell types in the tissues which were examined were not reactive, except for scattered fibroblasts and histiomonocytic cells, trophoblastic cells of the placenta, and benign immature mesenchymal cells in a renal cystadenocarcinoma. By cytofluorography, the antibodies were found to be unreactive with granulocytes, T lymphocytes, B lymphocytes, and the majority of monocytes. Fibroblasts were reactive with the antibodies, but the fluorescence tracings indicated a lower density of antigen on these cells than on endothelial cells. Immunoreactivity of fibroblasts could be decreased by treatment of...