A class of large polysaccharides contains the antigenic determinants for the cytotoxic antibodies in a conventional syngeneic anti-F9 serum as well as a monoclonal antibody prepared against F9 cells.
The molecular natures of the antigenic targets detected by cytotoxic antibodies in both a monoclonal antibody (ECMA-3) made against F9 cells and a conventional mouse anti-F9 serum were investigated. Both of the antibodies precipitated a class of high molecular weight polysaccharides from Nonidet P40 lysates of F9 cells. These molecules were labeled by radioactive galactose and fucose but only poorly by amino acids; in addition, they were fairly resistant to pronase and the digest still had a molecular weight of 70 K or more. Even after extensive pronase digestion the polysaccharides inhibited the cytotoxic activities of the antibodies, suggesting that the antigenic targets reside on the carbohydrate portion. This class of polysaccharides was shown to be a minor component of the characteristic large polysaccharides of F9 cells.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology*; D051379:Mice; D011134:Polysaccharides / Q000276:immunology*; D013724:Teratoma / Q000276:immunology
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D000939:Epitopes; D011134:Polysaccharides