Abstract
A cell line that normally supports the replication of herpes simplex virus types 1 and 2 became resistant to these viruses after transformation by simian adenovirus 7. Kinetic studies of the mechanism of resistance demonstrated that both herpesviruses were able to attach to the transformed cells and express some early genomic functions, as demonstrated by the presence of low levels of viral thymidine kinase. However, isopycnic centrifugation studies of the abortive system failed to detect viral deoxyribonucleic acid synthesis, whereas indirect immunofluorescent studies of viral proteins revealed that less than 10 per cent of the cells contained these viral macromolecules at any given time. Collectively the data suggest that after transformation by simian adenovirus 7 these cells are altered so as to render them resistant or incapable of supporting the growth of herpes simplex virus types 1 and 2. The results further suggest that the block occurs after viral absorption and prior to viral deoxyribonucleic acid synthesis.