Monoclonal antibody against angiotensin-converting enzyme: its use as a marker for murine, bovine, and human endothelial cells.

Abstract

A monoclonal antibody was prepared against rat angiotensin-converting enzyme (ACE). By selection for antibody binding to endothelial cells of bovine rather than rat origin a reagent was obtained that has broad cross-species binding properties and that can at the same time serve as a useful marker for the surface of endothelial cells. The IgM-producing clone that was established, .alpha.-ACE 3.1.1, was grown in ascites form to yield ascites fluid that binds selectively to immobilized ACE at a > 1:10,000 dilution. By use of enzyme-linked immunosorbent assays, immunofluorescence histology and flow cytometry, the presence of ACE on endothelial cells of murine, bovine and human origin was demonstrated. By means of a fluorescence-activated cell sorter (FACS-IV) viable endothelial cells were selectively isolated from a mixture of endothelial cells and fibroblasts. The antibody should be useful not only for the selection and in vitro cultivation of endothelial cells but also as a tool for the identification and pharmacological study of ACE.