title: Latency and reactivation of Marek's disease virus in B lymphocytes transformed by avian leukosis virus.
abstract: The physical and biological state of the Marek's disease virus (MDV) genome in avian leukosis virus (ALV)-transformed cells is characterized using cell lines established from ALV tumours co-infected with the SB-1 strain of MDV. The MDV genome within the ALV-transformed cells was found to be methylated at 5' CpG 3' dinucleotides. Less than 2% of the tumour cells expressed MDV antigen and only one virus plaque that was characteristic of an MDV infection was noted when tumour cells were cocultured with fibroblasts permissive for a productive MDV infection. However, when methylation of the MDV genome was prevented by culturing the tumour cell lines in the presence of 5-azacytidine, both MDV antigen expression and viral replication increased. Based on these results, it appears that MDV resides within the ALV-transformed cells in a latent state and that MDV latency might be influenced, to some extent, by methylation of the MDV genome.
authors.affiliation: Jefferson Cancer Institute, Thomas Jefferson Medical College, Philadelphia, Pennsylvania 19107.
authors.forename: E F
authors.initials: EF
authors.lastname: Fynan
authors.forename: D L
authors.initials: DL
authors.lastname: Ewert
authors.forename: T M
authors.initials: TM
authors.lastname: Block
mesh_terms: D001355:Alpharetrovirus / Q000502:physiology*; D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D001402:B-Lymphocytes / Q000382:microbiology*; D002460:Cell Line; D002472:Cell Transformation, Viral / Q000502:physiology; D002642:Chick Embryo; D004279:DNA, Viral / Q000032:analysis / Q000187:drug effects; D008381:Herpesvirus 2, Gallid / Q000302:isolation & purification / Q000502:physiology*; D008745:Methylation / Q000187:drug effects; D017735:Virus Latency / Q000502:physiology*
chemical_list: D004279:DNA, Viral; D001374:Azacitidine