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Methylation of Epstein–Barr virus Rta promoter in EBV primary infection, reactivation and lymphoproliferation
Author(s) -
Germi Raphaële,
Guigue Nicolas,
Lupo Julien,
Semenova Touyana,
Grossi Laurence,
Vermeulen Odile,
Epaulard Olivier,
de Fraipont Florence,
Morand Patrice
Publication year - 2016
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.24524
Subject(s) - lytic cycle , epstein–barr virus , methylation , mononucleosis , virology , dna methylation , cpg site , biology , viral load , virus , gene silencing , gammaherpesvirinae , bzlf1 , epigenetics , virus latency , viral replication , immunology , herpesviridae , gene , viral disease , genetics , gene expression
During Epstein–Barr virus (EBV) latency, the EBV genome is largely silenced by methylation. This silencing is overturned during the switch to the lytic cycle. A key event is the production of the viral protein Zta which binds to three Zta‐response elements (ZRE) from the Rta promoter (Rp), two of which (ZRE2 and ZRE3) include three CpG motifs methylated in the latent genome. The bisulphite pyrosequencing reaction was used to quantify the methylation of ZRE2, ZRE3a, and ZRE3b in EBV‐positive cell lines and in ex vivo samples of EBV‐related diseases, in order to assess whether the level of methylation in these ZREs could provide additional information to viral DNA load and serology in the characterization of EBV‐associated diseases. In PBMC from two patients with infectious mononucleosis, over time Rp became increasingly methylated whereas EBV load decreased. In tonsil from patients with chronic tonsillitis, the methylation was less than in EBV‐associated tumors, regardless of the viral load. This was even more striking when only the ZRE3a and ZRE3b were considered since some samples presented unbalanced profiles on ZRE2. EBV reactivation in cell culture showed that the reduction in the overall level of methylation was closely related to the production of unmethylated virions. Thus, an assessment of the level of methylation may help to better characterize EBV replication in PBMC and in biopsies with high EBV load, during infectious mononucleosis and EBV‐associated cancers. J. Med. Virol. 88:1814–1820, 2016 . © 2016 Wiley Periodicals, Inc.