RT Journal Article SR Electronic T1 Antigenic modulation induced by monoclonal antibodies: antibodies to measles virus hemagglutinin alters expression of other viral polypeptides in infected cells. JF The Journal of Immunology JO J. Immunol. FD American Association of Immunologists SP 2618 OP 2621 VO 132 IS 5 A1 Fujinami, R S A1 Norrby, E A1 Oldstone, M B YR 1984 UL http://www.jimmunol.org/content/132/5/2618.abstract AB Polyclonal antibody to measles virus can have profound effects on external (outer plasma membrane) as well as internal (cytoplasmic) viral polypeptides expressed in infected cells. The process, termed "antibody-induced antigenic modulation," was further investigated by using monoclonal antibody to several viral polypeptides. Four monoclonal antibodies against the viral hemagglutinin had the ability to decrease the expression of the phosphoprotein, fusion, and membrane protein. A monoclonal antibody to the nucleocapsid protein did not cause these changes. The observed decreases were not due to preferential degradation of viral polypeptides as determined by pulse-chase experiments. Our results indicate that a specific signal to an epitope on the plasma membrane (monoclonal antibody measles virus hemagglutinin) can alter the expression of measles virus phosphoprotein and membrane protein, both polypeptides present in the cytoplasm of infected cells.