Cell surface alterations induced by vaccinia and Newcastle disease viruses (38486)

A comparison was made of HEp-2 cell surface changes induced by NDV or vaccinia virus infection. Three parameters were examined as a function of time after infection: the kinetics of hemadosorption and the appearance of concanavalin (con A) binding sites, and alterations in electrophoretic mobility of single cells. The kinetics of appearance of con A binding sites was strikingly similar for both virus infections, whereas hemadsorption preceded NDA synthesis and followed vaccinia synthesis. These data suggest that in the vaccinia-infected cell the hemadsorption and con A binding sites are different. NDV infection or exposure of sham-infected cells to bacterial neuraminidase significantly reduced their anodal mobilities. This also occurred after enzyme treatment of vaccinia-infected cells. Measurements of the sialic acid content of NDV or sham-infected cells before and after neuraminidase treatment indicated the exposure to the enzyme or NDV materially reduced the sialic acid content of cells. Vaccinia-infected cells contained considerably more sialic acid than did normal cells. For the vaccinia-infected cell a change in surface properties as detected by hemadsorption or increased con A binding was not reflected in a change in electrophoretic mobility.