Transcriptional reactivation of murine cytomegalovirus ie gene expression by 5-aza-2'-deoxycytidine and trichostatin A in latently infected cells despite lack of methylation of the major immediate-early promoter.
We have used a spleen explant model to investigate mechanisms of murine cytomegalovirus latency and reactivation. Induction of immediate-early (ie) gene expression occurs in explants after approximately 9 days in culture and virus reactivation follows induction of ie gene expression with kinetics similar to that of productive infection in vitro. This occurs independently of TNF receptor signalling. Treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine and the histone deacetylase inhibitor trichostatin A results in more rapid induction of ie gene expression and reactivation of virus. Despite these results, which suggest a role for DNA methylation in maintenance of viral latency, we find that the major immediate-early promoter/enhancer is not methylated in latently infected mice. Our results support the hypothesis that latency is maintained by epigenetic control of ie gene expression, and that induction of ie gene expression leads to reactivation of virus, but suggest that these are not controlled by DNA methylation.
Hummel
Mary
M
Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.|Transplant Division, Department of Surgery, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Yan
Shixian
S
Transplant Division, Department of Surgery, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Li
Zhigao
Z
Transplant Division, Department of Surgery, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
Varghese
Thomas K
TK
Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, USA.
Abecassis
Michael
M
Department of Microbiology and Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.|Transplant Division, Department of Surgery, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019175:DNA Methylation; D004279:DNA, Viral / Q000737:chemistry; D000077209:Decitabine; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D017781:Genes, Immediate-Early / Q000187:drug effects*; D006877:Hydroxamic Acids / Q000494:pharmacology*; D017874:Immediate-Early Proteins / Q000096:biosynthesis; D051379:Mice; D023421:Models, Animal; D018146:Muromegalovirus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic; D011533:Proviruses / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D014158:Transcription, Genetic; D014775:Virus Activation / Q000187:drug effects*
D004279:DNA, Viral; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; D017874:Immediate-Early Proteins; C012589:trichostatin A; D000077209:Decitabine; D001374:Azacitidine