title: Persistence of a repressed Epstein-Barr virus genome in Burkitt lymphoma cells made resistant to 5-bromodeoxyuridine.
abstract: The P3HR-1 line of human lymphoblastoid cells that is Epstein-Barr virus positive was made resistant to 5-bromodeoxyuridine. Epstein-Barr virus-associated antigens, but not virus particles, were produced in P3HR-1(BU) cells maintained on 5-bromodeoxyuridine. However, virus particles did appear within 4 days after removal of the drug. Thymidine kinase activity was limited to P3HR-1(BU) cells producing viral antigen, whereas all control P3HR-1 cells showed thymidine kinase activity regardless of viral antigen synthesis. Cellular DNA in most P3HR-1(BU) cells was made via pathways that did not involve thymidine kinase. In cells having a pathway that involved thymidine kinase, a second DNA of density 1.71 g/cm(3), corresponding to Epstein-Barr virus, was detected.IT WAS CONCLUDED THAT: (a) a repressed Epstein-Barr virus genome persists in P3HR-1(BU) cells that do not contain thymidine kinase, with activation of the viral genome being accompanied by productive infection and the appearance of enzyme, and (b) thymidine kinase activity in P3HR-1(BU) cells could be used as a marker for viral genome expression.
mesh_terms: D000818:Animals; D000956:Antigens, Viral; D001345:Autoradiography; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002051:Burkitt Lymphoma / Q000276:immunology*; D002460:Cell Line; D002478:Cells, Cultured; D004279:DNA, Viral / Q000096:biosynthesis; D005455:Fluorescent Antibody Technique; D006041:Goats; D006564:Herpesviridae / Q000276:immunology*; D004854:Herpesvirus 4, Human / Q000201:enzymology / Q000276:immunology; D006801:Humans; D007106:Immune Sera; D008854:Microscopy, Electron; D013045:Species Specificity; D013937:Thymidine Kinase / Q000378:metabolism; D014316:Tritium; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral; D007106:Immune Sera; D014316:Tritium; D013937:Thymidine Kinase; D001973:Bromodeoxyuridine