Transmembrane communication in cells chronically infected with measles virus

The transmembrane association of the measles virus hemagglutinin and hemolysin surface proteins with intracellular viral antigens was studied. Rabbit antisera monospecific for measles virus matrix and nucleocapsid proteins and a human antiserum containing specificities for both the hemagglutinin and hemolysin proteins were used to study the co-capping of these proteins in human Lu 106 cell-line, chronically infected with measles virus. Capping of the surface-associated envelope components was accompanied by co-capping of the matrix and nucleocapsid proteins, the latter being localized mainly within the inclusions. This demonstrated transmembrane communication between surface-associated envelope components and the intracellular measles virus matrix and nucleocapsid proteins. The results demonstrated the existence of a linkage between viral inclusions and viral proteins associated with cell membranes. In the presence of cytochalasin B (1--2 micrograms/ml), co-capping of the matrix protein was unchanged or slightly enhanced, whereas co-capping of the nucleocapsid protein decreased, indicating that actin filaments may mediate the communication between viral nucleocapsids and the cell membrane.