scholarly journals Epstein-Barr virus lytic replication induces ACE2 expression and enhances SARS CoV-2 pseudotyped virus entry in epithelial cells

2021 ◽  
Author(s):  
Dinesh Verma ◽  
Trenton Mel Church ◽  
Sankar Swaminathan
Keyword(s):  
Epithelial Cells ◽  
Epstein Barr Virus ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Spike Protein ◽  
Cell Surface Expression ◽  
Pseudotyped Virus ◽  
Virus Surface ◽  
Barr Virus ◽  
Epstein Barr

Understanding factors that affect the infectivity of SARS CoV-2 is central to combatting COVID-19. The virus surface spike protein of SARS CoV-2 mediates viral entry into cells by binding to the ACE2 receptor on epithelial cells and promoting fusion. We find that Epstein-Barr virus (EBV) induces ACE2 expression when it enters the lytic replicative cycle in epithelial cells. By using VSV particles pseudotyped with the SARS CoV-2 spike protein, we show that lytic EBV replication enhances ACE2-dependent SARS CoV-2 pseudovirus entry. We find that the ACE2 promoter contains response elements for Zta, an EBV transcriptional activator that is essential for EBV entry into the lytic cycle of replication. Zta preferentially acts on methylated promoters, allowing it to reactivate epigenetically silenced EBV promoters from latency. By using promoter assays, we show that Zta directly activates methylated ACE2 promoters. Infection of normal oral keratinocytes with EBV leads to lytic replication in some of the infected cells, induces ACE2 expression and enhances SARS CoV-2 pseudovirus entry. These data suggest that subclinical EBV replication and lytic gene expression in epithelial cells, which is ubiquitous in the human population, may enhance the efficiency and extent of SARS CoV-2 infection of epithelial cells by transcriptionally activating ACE2 and increasing its cell surface expression. Importance SARS CoV-2, the coronavirus responsible for COVID-19, has caused a pandemic leading to millions of infections and deaths worldwide. Identifying the factors governing susceptibility to SARS CoV-2 is important in order to develop strategies to prevent SARS CoV-2 infection. We show that Epstein-Barr virus, which infects and persists in >90% of adult humans, increases susceptibility of epithelial cells to infection by SARS CoV-2. EBV, when it reactivates from latency or infects epithelial cells, increases expression of ACE2, the cellular receptor for SARS CoV-2, enhancing infection by SARS CoV-2. Inhibiting EBV replication with antivirals may therefore decrease susceptibility to SARS CoV-2 infection.

scholarly journals Interaction sites of the Epstein–Barr virus Zta transcription factor with the host genome in epithelial cells

2021 ◽  
Vol 3 (11) ◽  
Author(s):  
Anja Godfrey ◽  
Kay Osborn ◽  
Alison J. Sinclair
Keyword(s):  
Transcription Factor ◽  
B Cells ◽  
Epithelial Cells ◽  
Binding Sites ◽  
Epstein Barr Virus ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Barr Virus ◽  
Epstein Barr ◽  
The Impact

Epstein–Barr virus (EBV) is present in a state of latency in infected memory B-cells and EBV-associated lymphoid and epithelial cancers. Cell stimulation or differentiation of infected B-cells and epithelial cells induces reactivation to the lytic replication cycle. In each cell type, the EBV transcription and replication factor Zta (BZLF1, EB1) plays a role in mediating the lytic cycle of EBV. Zta is a transcription factor that interacts directly with Zta response elements (ZREs) within viral and cellular genomes. Here we undertake chromatin-precipitation coupled to DNA-sequencing (ChIP-Seq) of Zta-associated DNA from cancer-derived epithelial cells. The analysis identified over 14 000 Zta-binding sites in the cellular genome. We assessed the impact of lytic cycle reactivation on changes in gene expression for a panel of Zta-associated cellular genes. Finally, we compared the Zta-binding sites identified in this study with those previously identified in B-cells and reveal substantial conservation in genes associated with Zta-binding sites.

scholarly journals CD8+ immunodominance among Epstein-Barr virus lytic cycle antigens directly reflects the efficiency of antigen presentation in lytically infected cells

2005 ◽  
Vol 201 (3) ◽  
pp. 349-360 ◽  
Author(s):  
Victoria A. Pudney ◽  
Alison M. Leese ◽  
Alan B. Rickinson ◽  
Andrew D. Hislop
Keyword(s):  
T Cell ◽  
Epstein Barr Virus ◽  
Cd8 T Cell ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
E Proteins ◽  
Barr Virus ◽  
Infected Cells ◽  
Epstein Barr ◽  
L Proteins

Antigen immunodominance is an unexplained feature of CD8+ T cell responses to herpesviruses, which are agents whose lytic replication involves the sequential expression of immediate early (IE), early (E), and late (L) proteins. Here, we analyze the primary CD8 response to Epstein-Barr virus (EBV) infection for reactivity to 2 IE proteins, 11 representative E proteins, and 10 representative L proteins, across a range of HLA backgrounds. Responses were consistently skewed toward epitopes in IE and a subset of E proteins, with only occasional responses to novel epitopes in L proteins. CD8+ T cell clones to representative IE, E, and L epitopes were assayed against EBV-transformed lymphoblastoid cell lines (LCLs) containing lytically infected cells. This showed direct recognition of lytically infected cells by all three sets of effectors but at markedly different levels, in the order IE > E ≫ L, indicating that the efficiency of epitope presentation falls dramatically with progress of the lytic cycle. Thus, EBV lytic cycle antigens display a hierarchy of immunodominance that directly reflects the efficiency of their presentation in lytically infected cells; the CD8+ T cell response thereby focuses on targets whose recognition leads to maximal biologic effect.

scholarly journals Antibodies to gp350/220 Enhance the Ability of Epstein-Barr Virus To Infect Epithelial Cells

2006 ◽  
Vol 80 (19) ◽  
pp. 9628-9633 ◽  
Author(s):  
Susan M. Turk ◽  
Ru Jiang ◽  
Liudmila S. Chesnokova ◽  
Lindsey M. Hutt-Fletcher
Keyword(s):  
B Cells ◽  
Nasopharyngeal Carcinoma ◽  
Epithelial Cells ◽  
Epstein Barr Virus ◽  
Lytic Cycle ◽  
Virus Envelope ◽  
Barr Virus ◽  
High Risk Populations ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) is a persistent, orally transmitted herpesvirus that replicates in B cells and epithelial cells and is associated with lymphoid and epithelial malignancies. The virus binds to CD21 on B cells via glycoprotein gp350/220 and infects efficiently. Infection of cultured epithelial cells has not typically been efficient but can occur in the absence of gp350/220 and CD21 and in vivo is thought to be important to the development of nasopharyngeal carcinoma. We report here that antibodies to gp350/220, which inhibit EBV infection of B cells, enhance infection of epithelial cells. The effect is not mediated by Fc receptor binding but is further enhanced by antibody cross-linking, which may patch gp350/220 in the virus envelope. Saliva from EBV-seropositive individuals has similar effects that can be reversed by depletion of antibody. The results are consistent with a model in which gp350/220 interferes with the access of other important players to the epithelial cell surface. The results may have implications for the development of nasopharyngeal carcinoma in high-risk populations in which elevated titers of antibody to EBV lytic cycle proteins are prognostic.

scholarly journals The BFRF1 Gene of Epstein-Barr Virus Encodes a Novel Protein

2000 ◽  
Vol 74 (7) ◽  
pp. 3235-3244 ◽  
Author(s):  
Antonella Farina ◽  
Roberta Santarelli ◽  
Roberta Gonnella ◽  
Roberto Bei ◽  
Raffaella Muraro ◽  
...  
Keyword(s):  
Cell Lines ◽  
Epstein Barr Virus ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Particle Identification ◽  
Early Gene ◽  
Cell Fractionation ◽  
Barr Virus ◽  
F Region ◽  
Epstein Barr

ABSTRACT Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The BamHI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in theBamHI F region (BFRF1). Histidine and glutathione S-transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 MAb recognizes a doublet migrating at 37 to 38 kDa in cells extracts from EBV-infected cell lines following lytic cycle activation and in an EBV-negative cell line (DG75) transfected with a plasmid expressing the BFRF1 gene. Northern blot analysis allowed the detection of a major transcript of 3.7 kb highly expressed in EBV-positive lytic cycle-induced cell lines. Treatment with inhibitors of viral DNA polymerase, such as phosphonoacetic acid and acyclovir, reduced but did not abolish the transcription ofBFRF1, thus indicating that BFRF1 can be classified as an early gene. Cell fractionation experiments, as well as immunolocalization by immunofluorescence microscopy, immunohistochemistry, and immunoelectron microscopy, showed that BFRF1 is localized on the plasma membrane and nuclear compartments of the cells and is a structural component of the viral particle. Identification of BFRF1 provides a new marker with which to monitor EBV infection and might help us better understand the biology of the virus.

scholarly journals Epstein–Barr virus origin of lytic replication mediates association of replicating episomes with promyelocytic leukaemia protein nuclear bodies and replication compartments

2006 ◽  
Vol 87 (5) ◽  
pp. 1133-1137 ◽  
Author(s):  
Wolfgang Amon ◽  
Robert E. White ◽  
Paul J. Farrell
Keyword(s):  
Gene Expression ◽  
Epstein Barr Virus ◽  
Lytic Replication ◽  
Nuclear Bodies ◽  
Lytic Cycle ◽  
Promyelocytic Leukaemia ◽  
Late Gene ◽  
Barr Virus ◽  
Pml Nuclear Bodies ◽  
Epstein Barr

Epstein–Barr virus (EBV) establishes a latent persistence from which it can be reactivated to undergo lytic replication. Late lytic-cycle gene expression is linked to lytic DNA replication, as it is sensitive to the same inhibitors that block lytic replication, and it has recently been shown that the viral origin of lytic replication (ori lyt) is required in cis for late-gene expression. During the lytic cycle, the viral genome forms replication compartments, which are usually adjacent to promyelocytic leukaemia protein (PML) nuclear bodies. A tetracycline repressor DNA-binding domain–enhanced green fluorescent protein fusion was used to visualize replicating plasmids carrying a tetracycline operator sequence array. ori lyt mediated the production of plasmid replication compartments that were associated with PML nuclear bodies. Plasmids carrying ori lyt and EBV itself were visualized in the same cells and replicated in similar regions of the nucleus, further supporting the validity of the plasmids for studying late-gene regulation.

scholarly journals Evidence for DNA Hairpin Recognition by Zta at the Epstein-Barr Virus Origin of Lytic Replication

2010 ◽  
Vol 84 (14) ◽  
pp. 7073-7082 ◽  
Author(s):  
Andrew J. Rennekamp ◽  
Pu Wang ◽  
Paul M. Lieberman
Keyword(s):  
Dna Replication ◽  
Inverted Repeat ◽  
Epstein Barr Virus ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Productive Infection ◽  
Dna Hairpin ◽  
Barr Virus ◽  
Early Protein ◽  
Epstein Barr

ABSTRACT The Epstein-Barr virus immediate-early protein (Zta) plays an essential role in viral lytic activation and pathogenesis. Zta is a basic zipper (b-Zip) domain-containing protein that binds multiple sites in the viral origin of lytic replication (OriLyt) and is required for lytic-cycle DNA replication. We present evidence that Zta binds to a sequence-specific, imperfect DNA hairpin formed by an inverted repeat within the upstream essential element (UEE) of OriLyt. Mutations in the OriLyt sequence that are predicted to disrupt hairpin formation also disrupt Zta binding in vitro. Restoration of the hairpin rescues the defect. We also show that OriLyt DNA isolated from replicating cells contains a nuclease-sensitive region that overlaps with the inverted-repeat region of the UEE. Furthermore, point mutations in Zta that disrupt specific recognition of the UEE hairpin are defective for activation of lytic replication. These data suggest that Zta acts by inducing and/or stabilizing a DNA hairpin structure during productive infection. The DNA hairpin at OriLyt with which Zta interacts resembles DNA structures formed at other herpesvirus origins and may therefore represent a common secondary structure used by all herpesvirus family members during the initiation of DNA replication.

scholarly journals Epstein-Barr Virus WZhet DNA Can Induce Lytic Replication in Epithelial Cells in vitro, although WZhet Is Not Detectable in Many Human Tissues in vivo

Intervirology ◽  
2009 ◽  
Vol 52 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Julie L. Ryan ◽  
Richard J. Jones ◽  
Sandra H. Elmore ◽  
Shannon C. Kenney ◽  
George Miller ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Epstein Barr Virus ◽  
Lytic Replication ◽  
Human Tissues ◽  
Barr Virus ◽  
Epstein Barr

scholarly journals Inhibition of the Epstein–Barr virus lytic cycle by Zta-targeted RNA interference

2004 ◽  
Vol 85 (6) ◽  
pp. 1371-1379 ◽  
Author(s):  
Yao Chang ◽  
Shih-Shin Chang ◽  
Heng-Huan Lee ◽  
Shin-Lian Doong ◽  
Kenzo Takada ◽  
...  
Keyword(s):  
Rna Interference ◽  
Epstein Barr Virus ◽  
Disease Risk ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Viral Gene ◽  
Barr Virus ◽  
Ebv Reactivation ◽  
Epstein Barr

Epstein–Barr virus (EBV) reactivation into the lytic cycle plays certain roles in the development of EBV-associated diseases, so an effective strategy to block the viral lytic cycle may be of value to reduce the disease risk or to improve the clinical outcome. This study examined whether the EBV lytic cycle could be inhibited using RNA interference (RNAi) directed against the essential viral gene Zta. In cases of EBV reactivation triggered by chemicals or by exogenous Rta, Zta-targeted RNAi prevented the induction of Zta and its downstream genes and further blocked the lytic replication of viral genomes. This antiviral effect of RNAi was not likely to be mediated by activation of the interferon pathway, as phosphorylation of STAT1 was not induced. In addition, novel EBV-infected epithelial cells showing constitutive activation of the lytic cycle were cloned; such established lytic infection was also suppressed by Zta-targeted RNAi. These results indicate that RNAi can be used to inhibit the EBV lytic cycle effectively in vitro and could also be of potential use to develop anti-EBV treatments.

scholarly journals The Epstein–Barr virus lytic cycle activator Zta interacts with methylated ZRE in the promoter of host target gene egr1

2009 ◽  
Vol 90 (6) ◽  
pp. 1450-1454 ◽  
Author(s):  
James Heather ◽  
Kirsty Flower ◽  
Samine Isaac ◽  
Alison J. Sinclair
Keyword(s):  
Epstein Barr Virus ◽  
Target Gene ◽  
Distal Part ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Viral Gene ◽  
Reporter Construct ◽  
Barr Virus ◽  
Epstein Barr ◽  
Host Target

Activation of the host gene egr1 is essential for the lytic replication of Epstein–Barr virus (EBV). egr1 is activated by Zta (BZLF1, ZEBRA). Zta interacts directly with DNA through a series of closely related Zta-response elements (ZREs). Here we dissect the mechanism used by Zta to interact with the egr1 promoter and identify a weak interaction with egr1ZRE that is dependent on the distal part of egr1ZRE. Furthermore, we demonstrate that the ability of Zta to interact with egr1ZRE is enhanced at least tenfold by methylation. The ability of Zta to transactivate a reporter construct driven by the egr1 promoter can be enhanced by methylation. As the ability of Zta to interact with a methylated ZRE in the EBV genome correlates with its ability to activate the expression of the endogenous viral gene BRLF1, this suggests that Zta may also have the capability to overturn epigenetic control of egr1.

scholarly journals B Cell Receptor-Responsive miR-141 Enhances Epstein-Barr Virus Lytic Cycle via FOXO3 Inhibition

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Yan Chen ◽  
Devin N. Fachko ◽  
Nikita S. Ivanov ◽  
Rebecca L. Skalsky
Keyword(s):  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Cell Receptor ◽  
Lytic Replication ◽  
B Cell Receptor ◽  
Lytic Cycle ◽  
Cross Linking ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT Antigen recognition by the B cell receptor (BCR) is a physiological trigger for reactivation of Epstein-Barr virus (EBV) and can be recapitulated in vitro by cross-linking of surface immunoglobulins. Previously, we identified a subset of EBV microRNAs (miRNAs) that attenuate BCR signal transduction and subsequently dampen lytic reactivation in B cells. The roles of host miRNAs in the EBV lytic cycle are not completely understood. Here, we profiled the small RNAs in reactivated Burkitt lymphoma cells and identified several miRNAs, such as miR-141, that are induced upon BCR cross-linking. Notably, EBV encodes a viral miRNA, miR-BART9, with sequence homology to miR-141. To better understand the functions of these two miRNAs, we examined their molecular targets and experimentally validated multiple candidates commonly regulated by both miRNAs. Targets included B cell transcription factors and known regulators of EBV immediate-early genes, leading us to hypothesize that these miRNAs modulate kinetics of the lytic cascade in B cells. Through functional assays, we identified roles for miR-141 and EBV miR-BART9 and one specific target, FOXO3, in progression of the lytic cycle. Our data support a model whereby EBV exploits BCR-responsive miR-141 and further mimics activity of this miRNA family via a viral miRNA to promote productive lytic replication. IMPORTANCE EBV is a human pathogen associated with several malignancies. A key aspect of lifelong virus persistence is the ability to switch between latent and lytic replication modes. The mechanisms governing latency, reactivation, and progression of the lytic cycle are only partly understood. This study reveals that specific miRNAs can act to support the EBV lytic phase following BCR-mediated reactivation triggers. Furthermore, this study identifies a role for FOXO3, commonly suppressed by both host and viral miRNAs, in modulating progression of the EBV lytic cycle.

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