title: Growth dynamics of a latent primate papovavirus.
abstract: The stumptailed macaque papovavirus strain HD was discovered in a persistently infected cell line of primate origin designated Vero 76 (K. Bosslet and G. Sauer, J. Virol. 25:596--607, 1978; W. Waldeck and G. Sauer, Nature [London] 269:171--173, 1977). In clonal derivatives of Vero 76 cells a minor and variable proportion of cells is engaged in the productive synthesis of the HD virus strain. A combination of immunofluorescence using simian virus 40 polyoma subgroup-specific antiserum and in situ hybridization with HD complementary RNA revealed that only those cells which harbor discernible amounts of HD DNA also contain the subgroup-specific antigen. Treatment with arabinofuranosylcytosine caused irreversible disappearance of the antigen, whereas actinomycin D, in contrast, reversibly inhibited both HD DNA replication and synthesis of the subgroup-specific antigen. The proportion of HD DNA and subgroup-specific antigen-synthesizing cells in Vero 76 clonal lines could be either decreased or increased by the mode of passaging of the cell cultures. When cell cultures were split every 3 to 7 days at a 1:4 ratio, the amount of HD DNA sequences as revealed by DNA-DNA reassociation and by the Southern blotting technique fell below the level of detection after only a few passages. Furthermore, expression of the viral subgroup-specific antigen was no longer discernible. However, viral DNA persists in such latently infected cells, because a change in the splitting protocol to a 2-week passaging rhythm led to reinitiation of both viral DNA replication and expression of the subgroup-specific antigen. The HD DNA is perpetuated in a restricted state in latently infected cells in an episomal, unintegrated form as shown by Southern blot analysis. This finding complies with the fact that HD DNA-free subclones could be derived from persistently infected clonal Vero 76 cells. Such subclones have lost the viral genomes, probably owing to segregation during cell division.
mesh_terms: D000818:Animals; D000956:Antigens, Viral; D002455:Cell Division; D002460:Cell Line; D002522:Chlorocebus aethiops; D002999:Clone Cells; D004261:DNA Replication / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology; D007700:Kinetics; D027383:Papillomaviridae / Q000254:growth & development*; D027382:Polyomaviridae; D014764:Viral Proteins / Q000096:biosynthesis; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000956:Antigens, Viral; D014764:Viral Proteins; D003609:Dactinomycin