Monoclonal antibodies against the extracellular domain of the erbB-2 receptor function as partial ligand agonists

摘要: In this paper we describe the isolation and characterization of four monoclonal antibodies (FRP5, FSP16, FWP51, FSP77) which specifically recognize human erbB-2 protein. All epitopes on extracellular domain receptor FRP5 FSP16 compete with one another for binding while FWP51 FSP77 each a different epitope. The effects protein have been analyzed. Two erbB-2-expressing cell lines, SKBR3 breast tumor cells HC11 R111 cells, were examined. express approximately 1 x 10(6) molecules protein/cell; clone mouse mammary epithelial derived by transfection expression plasmid, contain 10-fold less than cells. Treatment two lines FRP5, led to rapid increase in phosphotyrosine content Three antibodies, FSP77, stimulated turnover Binding did not stimulate DNA synthesis Thus, erbB-2-specific behave as partial ligand agonists. examined their upon growth was inhibited 90% following long term treatment FSP77.