Epstein-Barr Virus (EBV) nuclear antigen 3C inhibits expression of COBLL1 and the ADAM28-ADAMDEC1 locus via interaction with the histone lysine demethylase KDM2B

Epstein-Barr virus nuclear antigen 3C (EBNA3C) is a well-defined repressor of host gene expression in B cells transformed by Epstein-Barr virus (EBV) that cooperates with various cellular factors. It is established that EBNA3C interacts with the cellular factor RBPJ (RBP-Jκ or CBF1) through two distinct motifs: the TFGC motif, also called the homology domain (HD) motif, and the VWTP motif. In this study, we investigated the role of each motif in EBNA3C transcriptional repression activity by using two novel recombinant viruses with single RBPJ interaction motifs mutated (EBNA3C HDmut and EBNA3C W227S). Infection of primary B cells with either of these recombinant EBVs led to the successful establishment of lymphoblastoid cell lines (LCLs). Gene expression analysis showed that full repression of EBNA3C target genes is not achieved by EBNA3C HDmut compared to that with EBNA3C W227S or the EBNA3C wild type (WT). Focusing on the well-characterized EBNA3C-repressed genes COBLL1, ADAM28, and ADAMDEC1, we investigated the mechanism of EBNA3C-mediated transcriptional repression. Chromatin immunoprecipitation (ChIP) analysis indicated that EBNA3C HDmut is still able to recruit Polycomb proteins BMI1 and SUZ12 to COBLL1 as efficiently as EBNA3C WT does, leading to the full deposition of the repressive histone mark H3K27me3. However, we found that the activation-associated chromatin mark H3K4me3 is highly enriched at EBNA3C target genes in LCLs expressing EBNA3C HDmut. We show here that EBNA3C interacts with the histone lysine demethylase KDM2B and that this interaction is important for H3K4me3 removal and for the EBNA3C-mediated repression of COBLL1 and the ADAM28-ADAMDEC1 locus. IMPORTANCE EBV is a virus associated with human cancers and is well known for its ability to transform B lymphocytes into continuously proliferating lymphoblastoid cell lines. EBNA3C is considered an oncoprotein and has been shown to be essential for B cell transformation by EBV. EBNA3C is well characterized as a viral transcription factor, but very little is known about its mechanisms of action. In the present study, we demonstrate that removal of the activating histone mark H3K4me3 and deposition of the repressive mark H3K27me3 by EBNA3C on COBLL1 are achieved by at least two distinct mechanisms. Furthermore, we discovered that EBNA3C interacts with the lysine demethylase KDM2B and that this interaction is important for its transcriptional repressive function. The findings in this study provide new insights into the mechanism used by the oncoprotein EBNA3C to repress cellular target genes

Research Priorities for Children's Nursing in Ireland: A Delphi Study

This paper is a report of a study which identified research priorities for children's nursing in an acute care setting in Ireland. A limited number of studies have examined research priorities for children's nursing. This study was undertaken against the backdrop of significant proposed changes to the delivery of of children's healthcare. A three round Delphi survey design was used to identify and rate the importance of research priorities for children's nursing. In round 1 participants were asked to identify five of the most important research priorities for children's nursing. Participants in round 2 were asked to rate the importance of each of each research priority on a seven point Likert scale. In round 3 participants were presented with the mean scoreof each research priority from the second questionaire, and again asked to consider the importance of each topic on a 7 point Likert scale. The aim was to reach a consensus on the priorities. The top three priorities identified were recognition and care of the deteriorating child, safe transfer of the critically ill child between acute health care facilities, and the child and families perceptions of care at end-of life. The wide variation of priorities reflects the scope of care delivery of children's nurses and mirrors many global care concerns in caring for children