Monoclonal antibodies to damaged and regenerating vascular endothelium.

Monoclonal antibodies were raised by injecting mice with cultured bovine, porcine or human vascular endothelial cells, and tested in an in vitro model of endothelial damage and regrowth. Antibodies were identified which produced four distinct and reproducible immunoperoxidase staining patterns, and these were further characterized by Western blotting and I125 labelling. Antibodies which recognize damaged endothelial cells probably do so by reacting with intracellular antigens made accessible by increased membrane permeability. Other antibodies give a diffuse staining of intact cells, by reacting with a membrane component, or a "negative stain" pattern by reacting with extracellular matrix material. A small number of antibodies recognize new or spreading endothelium perhaps by recognizing selectively expressed antigens on these cells. Appropriate monoclonal antibodies may be useful in studying endothelial behaviour in vivo.