Monoclonal antibodies against five structural components of measles virus. I. Characterization of antigenic determinants on nine strains of measles virus.

Monoclonal antibodies against five structural proteins of measles virus were used to determine the degree of antigenic variation within these proteins amongst nine strains of measles virus (four fresh wild-type isolates, two vaccine and two laboratory strains, and a strain derived from a case of subacute sclerosing panencephalitis) giving lytic infections in cell culture. The major surface proteins showed limited variations in their epitopes between the nine strains. No variations in the fusion (F) protein and only three variations in the hemagglutinin (H) protein epitopes were detected by radioimmune precipitation assay and other serological tests using a panel of 11 monoclonal antibodies against each protein. These antibody panels consisted of at least nine and six different binding groups for the H and F proteins, respectively. The two innermost proteins, the nucleocapsid and polymerase proteins, also appeared to be antigenically stable as no variation was detected between strains using in each case a panel of six hybridomas. In sharp contrast, the epitopes on the matrix (M) protein of different strains showed extensive variation in their reactivity with the nine anti-M monoclonal antibodies. The possible use of M protein epitopic markers in classification of measles virus strains is discussed.