Enhancement of mRNA Synthesis from Marek's Disease Virus Genome in the Lymphoblastoid Cell Line, MDCC-MSB1, by 5-Azacytidine

Marek's disease virus (MDV) DNA in latently infected lymphoblastoid cell lines is considerably methylated. A treatment of the MDV-derived lymphoblastoid cell line, MDCC-MSB1 (MSB1), with 5-azacytidine (5-AzC) resulted in a hypomethylation of MDV DNA and an increase in mRNA from certain portions of the MDV DNA. These results suggest methylation of MDV DNA as being one of the factors associated with a repression of transcription of MDV DNA in the lymphoblastoid cell line, MSB1.