Characterization of the antigenic determinant on HSB-2 cells shared with myelin-associated glycoprotein (MAG) using monoclonal antibodies.

The existence of cross-antigenicity between myelin-associated glycoprotein (MAG) and natural killer cells has been reported previously. In this study, we have characterized the antigenic determinant on HSB-2 cells which is shared with MAG using two types of mouse monoclonal anti-MAG antibodies, one recognizing the peptide molecule (IgG-P) and the other recognizing the carbohydrate molecule of MAG (IgM-C). Enzyme-linked immunosorbent assay (ELISA) revealed that IgM-C was absorbed by cell homogenate of HSB-2, and some bands were stained by IgM-C on the immunoblot of HSB-2 cell homogenate, while IgG-P was not absorbed by HSB-2 cell homogenate and no band was stained by IgG-P on the immunoblot of HSB-2 cell homogenate. Therefore it is suggested that the shared antigenic determinant between MAG and HSB-2 cells is not in the peptide molecule but in the carbohydrate molecule.