scholarly journals Interpreting the Epstein-Barr Virus (EBV) Epigenome Using High-Throughput Data

Viruses ◽  
2013 ◽  
Vol 5 (4) ◽  
pp. 1042-1054 ◽  
Author(s):  
Aaron Arvey ◽  
Italo Tempera ◽  
Paul Lieberman
2020 ◽  
Vol 94 (21) ◽  
Author(s):  
Xiaofan Li ◽  
Ibukun A. Akinyemi ◽  
Jeehyun Karen You ◽  
Mohammad Ali Rezaei ◽  
Chenglong Li ◽  
...  

ABSTRACT Epstein-Barr virus (EBV) is one of nine human herpesviruses that persist latently to establish permanent residence in their hosts. Periodic activation into the lytic/replicative phase allows such viruses to propagate and spread, but can also cause disease in the host. This lytic phase is also essential for EBV to cause infectious mononucleosis and cancers, including B lymphocyte-derived Burkitt lymphoma and immunocompromise-associated lymphoproliferative diseases/lymphomas as well as epithelial cell-derived nasopharyngeal cell carcinoma. In the absence of anti-EBV agents, however, therapeutic options for EBV-related diseases are limited. In earlier work, we discovered that through the activities of the viral protein kinase conserved across herpesviruses and two cellular proteins, ATM and KAP1, a lytic cycle amplification loop is established, and disruption of this loop disables the EBV lytic cascade. We therefore devised a high-throughput screening assay, screened a small-molecule-compound library, and identified 17 candidates that impair the release of lytically replicated EBV. The identified compounds will (i) serve as lead compounds or may be modified to inhibit EBV and potentially other herpesviruses, and (ii) be developed into anticancer agents, as functions of KAP1 and ATM are tightly linked to cancer. Importantly, our screening strategy may also be used to screen additional compound libraries for antiherpesviral and anticancer drugs. IMPORTANCE Epstein-Barr virus, which is nearly ubiquitous in humans, is causal to infectious mononucleosis, chronic active EBV infection, and lymphoid and epithelial cancers. However, EBV-specific antiviral agents are not yet available. To aid in the identification of compounds that may be developed as antivirals, we pursued a mechanism-based approach. Since many of these diseases rely on EBV’s lytic phase, we developed a high-throughput assay that is able to measure a key step that is essential for successful completion of EBV’s lytic cascade. We used this assay to screen a library of small-molecule compounds and identified inhibitors that may be pursued for their anti-EBV and possibly even antiherpesviral potential, as this key mechanism appears to be common to several human herpesviruses. Given the prominent role of this mechanism in both herpesvirus biology and cancer, our screening assay may be used as a platform to identify both antiherpesviral and anticancer drugs.


Virology ◽  
2015 ◽  
Vol 474 ◽  
pp. 117-130 ◽  
Author(s):  
Rosemary J Tierney ◽  
Claire D Shannon-Lowe ◽  
Leah Fitzsimmons ◽  
Andrew I Bell ◽  
Martin Rowe

2010 ◽  
Vol 15 (9) ◽  
pp. 1107-1115 ◽  
Author(s):  
Scott Thompson ◽  
Troy Messick ◽  
David C. Schultz ◽  
Melvin Reichman ◽  
Paul M. Lieberman

Latent infection with Epstein-Barr virus (EBV) is a carcinogenic cofactor in several lymphoid and epithelial cell malignancies. At present, there are no small-molecule inhibitors that specifically target EBV latent infection or latency-associated oncoproteins. EBNA1 is an EBV-encoded sequence-specific DNA binding protein that is consistently expressed in EBV-associated tumors and required for stable maintenance of the viral genome in proliferating cells. EBNA1 is also thought to provide cell survival function in latently infected cells. In this work, the authors describe the development of a biochemical high-throughput screening (HTS) method using a homogeneous fluorescence polarization (FP) assay monitoring EBNA1 binding to its cognate DNA binding site. An FP-based counterscreen was developed using another EBV-encoded DNA binding protein, Zta, and its cognate DNA binding site. The authors demonstrate that EBNA1 binding to a fluorescent-labeled DNA probe provides a robust assay with a Z factor consistently greater than 0.6. A pilot screen of a small-molecule library of ~14,000 compounds identified 3 structurally related molecules that selectively inhibit EBNA1 but not Zta. All 3 compounds had activity in a cell-based assay specific for the disruption of EBNA1 transcription repression function. One of the compounds was effective in reducing EBV genome copy number in Raji Burkitt lymphoma cells. These experiments provide a proof of concept that small-molecule inhibitors of EBNA1 can be identified by biochemical HTS of compound libraries. Further screening in conjunction with medicinal chemistry optimization may provide a selective inhibitor of EBNA1 and EBV latent infection.


mBio ◽  
2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Rachel Hood Edwards ◽  
Aron R. Marquitz ◽  
Nancy Raab-Traub

ABSTRACTThe Epstein-Barr virus protein latent membrane protein 1 (LMP1) has two NF-κB activating domains within its intracellular carboxy terminus (carboxy-terminal activating region 1 [CTAR1] and CTAR2). LMP1-CTAR1 is required for B-lymphocyte transformation, is capable of transforming rodent fibroblasts, and uniquely activates phosphoinositol (PI3) kinase, the noncanonical NF-κB pathway, and expression of the epidermal growth factor receptor (EGFR). In this study, the effects of LMP1-CTAR1 on cellular gene expression were determined by high-throughput sequencing. Additionally, the binding of bcl3 was determined using chromatin immunoprecipitation (ChIP) and sequencing. LMP1-CTAR1 induced few changes in transcription with more genes showing decreased expression. Ingenuity pathway analysis indicated significant enrichment for genes involved in cancer and cellular movement, survival, growth, and proliferation pathways. ChIP in combination with high-throughput sequencing (ChIP-Seq) identified bcl3 binding for more than 2,000 genes in LMP1-CTAR1-expressing cells with more than 90% of the peaks at genes detected within the probable promoter region. Only a small subset of the genes with significant changes in expression had corresponding peaks in the bcl3 ChIP. However, both NFKB2 and PI3 kinase were identified in the bcl3 ChIP. Additionally, many of the predicted upstream regulators for the changes in expression were identified in the bcl3 ChIP. Analysis of the proteins in the NF-κB pathway revealed many changes identified by the high-throughput RNA sequencing (RNA-Seq) and bcl3 ChIP that would likely activate noncanonical NF-κB signaling and possibly inhibit canonical NF-κB signaling. These findings suggest that the two LMP1 signaling domains modulate their combined activity and that the bcl3 transcription factor is likely responsible for some of the unique effects of CTAR1 on cellular expression.IMPORTANCEThe Epstein-Barr virus protein latent membrane protein 1 (LMP1) has potent effects on cell growth. LMP1 has two regions, carboxy-terminal activating region 1 (CTAR1) and CTAR2, that distinctly activate NF-κB, a transcription factor complex involved in activation of important host genes. In this study, analysis of the effects on cellular gene expression revealed that CTAR1 significantly affected cellular expression in part through effects on a specific form of NF-κB. The data suggest that LMP1 can activate a distinct subset of host gene expression through its CTAR1 domain which in combination with other signaling effects induced by the CTAR2 domain likely affects cell movement, survival, and growth.


Author(s):  
C. M. Payne ◽  
P. M. Tennican

In the normal peripheral circulation there exists a sub-population of lymphocytes which is ultrastructurally distinct. This lymphocyte is identified under the electron microscope by the presence of cytoplasmic microtubular-like inclusions called parallel tubular arrays (PTA) (Figure 1), and contains Fc-receptors for cytophilic antibody. In this study, lymphocytes containing PTA (PTA-lymphocytes) were quantitated from serial peripheral blood specimens obtained from two patients with Epstein -Barr Virus mononucleosis and two patients with cytomegalovirus mononucleosis. This data was then correlated with the clinical state of the patient.It was determined that both the percentage and absolute number of PTA- lymphocytes was highest during the acute phase of the illness. In follow-up specimens, three of the four patients' absolute lymphocyte count fell to within normal limits before the absolute PTA-lymphocyte count.In one patient who was followed for almost a year, the absolute PTA- lymphocyte count was consistently elevated (Figure 2). The estimation of absolute PTA-lymphocyte counts was determined to be valid after a morphometric analysis of the cellular areas occupied by PTA during the acute and convalescent phases of the disease revealed no statistical differences.


Author(s):  
R. Stephens ◽  
K. Traul ◽  
D. Woolf ◽  
P. Gaudreau

A number of antigens have been found associated with persistent EBV infections of lymphoblastoid cells. Identification and localization of these antigens were principally by immunofluorescence (IF) techniques using sera from patients with nasopharyngeal carcinoma (NPC), Burkitt lymphoma (BL), and infectious mononucleosis (IM). Our study was mainly with three of the EBV related antigens, a) virus capsid antigen (VCA), b) membrane antigen (MA), and c) early antigens (EA) using immunoperoxidase (IP) techniques with electron microscopy (EM) to elucidate the sites of reactivity with EBV and EBV infected cells.Prior to labeling with horseradish peroxidase (HRP), sera from NPC, IM, and BL cases were characterized for various reactivities by the indirect IF technique. Modifications of the direct IP procedure described by Shabo and the indirect IP procedure of Leduc were made to enhance penetration of the cells and preservation of antigen reactivity.


2000 ◽  
Vol 111 (1) ◽  
pp. 239-246 ◽  
Author(s):  
Kenny I. K. Lei ◽  
Lisa Y.S. Chan ◽  
Wing Y. Chan ◽  
Philip J. Johnson ◽  
Y. M. Dennis Lo

1996 ◽  
Vol 21 (2) ◽  
pp. 123-126
Author(s):  
U. BALDARI ◽  
A. ASCARI RACCAGNI ◽  
B. CELLI ◽  
M. GIOVANNA RIGHINI

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