Cytolytic Effects of Mumps Virus in Tissue Cultures of Epithelial Cells. ∗

Summary

Upon inoculation of cultures of HeLa or monkey kidney epithelial cells with large amounts of several strains of mumps virus at various stages of chick embryo-adaptation lesions resembling “giant cells” were observed, which however were shown to be caused by a cytolytic property of the agents. This effect could not be maintained on serial passage when allantoically-adapted strains were employed. Cytolysis was specifically prevented by human mumps convalescent and post-vaccination sera but not, or to a lesser extent, by sera taken during the acute stage of the disease or prior to immunization. The cytolytic activity was found to be more resistant to ultraviolet light than the infectious property. The possible relation of the cytolytic effect to the hemolytic activity of the virus is discussed.