scholarly journals Visualization of Alternative Epstein-Barr Virus Expression Programs by Fluorescent In Situ Hybridization at the Cell Level

1999 ◽  
Vol 73 (6) ◽  
pp. 5064-5069 ◽  
Author(s):  
Anna Szeles ◽  
Kerstin I. Falk ◽  
Stephan Imreh ◽  
George Klein
Keyword(s):  
In Situ Hybridization ◽  
Cell Lines ◽  
Fluorescent In Situ Hybridization ◽  
Epstein Barr Virus ◽  
Type I ◽  
Type Iii ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) transforms human B lymphocytes into immortalized lymphoblastoid cell lines (LCLs). They regularly express six virally encoded nuclear proteins (EBNA1 to EBNA6) and three membrane proteins (LMP1, LMP2A, and LMP2B). In contrast, EBV-carrying Burkitt lymphoma (BL) cells in vivo and derived type I cell lines that maintain the BL phenotype express only EBNA1. During prolonged in vitro culturing, most EBV-carrying BL lines drift toward a more immunoblastic (type II or III) phenotype. Their viral antigen expression is upregulated in parallel. We have used fluorescent in situ hybridization to visualize viral transcripts in type I and III BL lines and LCLs. In type I cells, EBNA1 is encoded by a monocistronic message that originates from the Qp promoter. In type III cells, the EBNA1 transcript is spliced from a giant polycistronic message that originates from one of several alternative Wp or Cp promoters and encodes all six EBNAs. We have obtained a “track” signal with aBamHI W DNA probe that could hybridize with the polycistronic but not with the monocistronic message in two type III BL lines (Namalwa-Cl8 and MUTU III) and three LCLs (LCL IB4-D, LCL-970402, and IARC-171). A BamHI K probe that can hybridize to both the monocistronic and the polycistronic message visualized the same pattern in the type III BLs and the LCLs as the BamHI W probe. A positive signal was obtained with the BamHI K but not the BamHI W probe in the type I BL lines MUTU I and Rael. The RNA track method can thus distinguish between cells that use a type III and those that use a type I program. The former cells hybridize with both the W and the K probes, but the latter cells hybridize with only the K probe. Our findings may open the way for studies of the important but still unanswered question of whether cells with type I latency arise from immunoblasts with a full type III program or are generated by a separate pathway during primary infection.

scholarly journals Regulation of Epstein-Barr Virus Latency Type by the Chromatin Boundary Factor CTCF

2006 ◽  
Vol 80 (12) ◽  
pp. 5723-5732 ◽  
Author(s):  
Charles M. Chau ◽  
Xiao-Yong Zhang ◽  
Steven B. McMahon ◽  
Paul M. Lieberman
Keyword(s):  
Cell Lines ◽  
Epstein Barr Virus ◽  
Ctcf Binding ◽  
Ctcf Binding Site ◽  
Type I ◽  
Mrna Levels ◽  
Type Iii ◽  
Barr Virus ◽  
Chromatin Boundary ◽  
Epstein Barr

ABSTRACT Epstein Barr virus (EBV) can establish distinct latency types with different growth-transforming properties. Type I latency and type III latency can be distinguished by the expression of EBNA2, which has been shown to be regulated, in part, by the EBNA1-dependent enhancer activity of the origin of replication (OriP). Here, we report that CTCF, a chromatin boundary factor with well-established enhancer-blocking activity, binds to EBV sequences between the OriP and the RBP-Jκ response elements of the C promoter (Cp) and regulates transcription levels of EBNA2 mRNA. Using DNA affinity, electrophoretic mobility shift assay, DNase I footprinting, and chromatin immunoprecipitation (ChIP), we found that CTCF binds both in vitro and in vivo to the EBV genome between OriP and Cp, with an ∼50-bp footprint at EBV coordinates 10515 to 10560. Deletion of this CTCF binding site in a recombinant EBV bacterial artificial chromosome (BAC) increased EBNA2 transcription by 3.5-fold compared to a wild-type EBV BAC. DNA affinity and ChIP showed more CTCF binding at this site in type I latency cell lines (MutuI and KemI) than in type III latency cell lines (LCL3456 and Raji). CTCF protein and mRNA expression levels were higher in type I than type III cell lines. Short interfering RNA depletion of CTCF in type I MutuI cells stimulated EBNA2 mRNA levels, while overexpression of CTCF in type III Raji cells inhibited EBNA2 mRNA levels. These results indicate that increased CTCF can repress EBNA2 transcription. We also show that c-MYC, as well as EBNA2, can stimulate CTCF mRNA levels, suggesting that CTCF levels may contribute to B-cell differentiation as well as EBV latency type determination.

scholarly journals Elevated expression of c-myc in lymphoblastoid cells does not support an Epstein–Barr virus latency III-to-I switch

2001 ◽  
Vol 82 (12) ◽  
pp. 3051-3055 ◽  
Author(s):  
Alexander Pajic ◽  
Axel Polack ◽  
Martin S. Staege ◽  
Dimitry Spitkovsky ◽  
Barbara Baier ◽  
...  
Keyword(s):  
Cell Lines ◽  
Epstein Barr Virus ◽  
Type I ◽  
Barr Virus ◽  
Virus Latency ◽  
Elevated Expression ◽  
Established Cell ◽  
Epstein Barr

Epstein–Barr virus (EBV) transforms primary B cells in vitro. Established cell lines adopt a lymphoblastoid phenotype (LCL). In contrast, EBV-positive Burkitt’s lymphoma (BL) cells, in which the proto-oncogene c-myc is constitutively activated, do not express a lymphoblastoid phenotype in vivo. The two different phenotypes are paralleled by two distinct programmes of EBV latent gene expression termed latency type I in BL cells and type III in LCL. Human B cell lines were established from a conditional LCL (EREB2-5) by overexpression of c-myc and inactivation of EBV nuclear protein 2 (EBNA2). These cells (A1 and P493-6) adopted a BL phenotype in the absence of EBNA2. However, the EBV latency I promoter Qp was not activated. Instead, the latency III promoter Cp remained active. These data suggest that the induction of a BL phenotype by overexpression of c-myc in an LCL is not necessarily paralleled by an EBV latency III-to-I switch.

scholarly journals Host-cell-determined methylation of specific Epstein-Barr virus promoters regulates the choice between distinct viral latency programs.

1997 ◽  
Vol 17 (1) ◽  
pp. 364-377 ◽  
Author(s):  
B C Schaefer ◽  
J L Strominger ◽  
S H Speck
Keyword(s):  
Host Cell ◽  
Cell Lines ◽  
Epstein Barr Virus ◽  
Gene Promoter ◽  
Cpg Methylation ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Barr Virus ◽  
Epstein Barr

Epstein-Barr virus (EBV) is capable of adopting three distinct forms of latency: the type III latency program, in which six EBV-encoded nuclear antigens (EBNAs) are expressed, and the type I and type II latency programs, in which only a single viral nuclear protein, EBNA1, is produced. Several groups have reported heavy CpG methylation of the EBV genome in Burkitt's lymphoma cell lines which maintain type I latency, and loss of viral genome methylation in tumor cell lines has been correlated with a switch to type III latency. Here, evidence that the type III latency program must be inactivated by methylation to allow EBV to enter the type I or type II restricted latency program is provided. The data demonstrates that the EBNA1 gene promoter, Qp, active in types I and II latency, is encompassed by a CpG island which is protected from methylation. CpG methylation inactivates the type III latency program and consequently allows the type I or II latency program to operate by alleviating EBNA1-mediated repression of Qp. Methylation of the type III latency EBNA gene promoter, Cp, appears to be essential to prevent type III latency, since EBNA1 is expressed in all latently infected cells and, as shown here, is the only viral antigen required for activation of Cp. EBV is thus a pathogen which subverts host-cell-determined methylation to regulate distinct genetic programs.

scholarly journals Epstein-Barr Virus Induces Adhesion Receptor CD226 (DNAM-1) Expression during Primary B-Cell Transformation into Lymphoblastoid Cell Lines

mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Lisa Grossman ◽  
Chris Chang ◽  
Joanne Dai ◽  
Pavel A. Nikitin ◽  
Dereje D. Jima ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Epstein Barr Virus ◽  
Human Herpesvirus ◽  
Barr Virus ◽  
Ebv Infection ◽  
Cellular Aggregation ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) is a common human herpesvirus that establishes latency in B cells. While EBV infection is asymptomatic for most individuals, immune-suppressed individuals are at significantly higher risk of a form of EBV latent infection in which infected B cells are reactivated, grow unchecked, and generate lymphomas. This form of latency is modeled in the laboratory by infecting B cells from the blood of normal human donors in vitro. In this model, we identified a protein called CD226 that is induced by EBV but is not normally expressed on B cells. Rather, it is known to play a role in aggregation and survival signaling of non-B cells in the immune system. Cultures of EBV-infected cells adhere to one another in “clumps,” and while the proteins that are responsible for this cellular aggregation are not fully understood, we hypothesized that this form of cellular aggregation may provide a survival advantage. In this article, we characterize the mechanism by which EBV induces this protein and its expression on lymphoma tissue and cell lines and characterize EBV-infected cell lines in which CD226 has been knocked out. Epstein-Barr virus (EBV), an oncogenic herpesvirus, infects and transforms primary B cells into immortal lymphoblastoid cell lines (LCLs), providing a model for EBV-mediated tumorigenesis. EBV transformation stimulates robust homotypic aggregation, indicating that EBV induces molecules that mediate cell-cell adhesion. We report that EBV potently induced expression of the adhesion molecule CD226, which is not normally expressed on B cells. We found that early after infection of primary B cells, EBV promoted an increase in CD226 mRNA and protein expression. CD226 levels increased further from early proliferating EBV-positive B cells to LCLs. We found that CD226 expression on B cells was independent of B-cell activation as CpG DNA failed to induce CD226 to the extent of EBV infection. CD226 expression was high in EBV-infected B cells expressing the latency III growth program, but low in EBV-negative and EBV latency I-infected B-lymphoma cell lines. We validated this correlation by demonstrating that the latency III characteristic EBV NF-κB activator, latent membrane protein 1 (LMP1), was sufficient for CD226 upregulation and that CD226 was more highly expressed in lymphomas with increased NF-κB activity. Finally, we found that CD226 was not important for LCL steady-state growth, survival in response to apoptotic stress, homotypic aggregation, or adhesion to activated endothelial cells. These findings collectively suggest that EBV induces expression of a cell adhesion molecule on primary B cells that may play a role in the tumor microenvironment of EBV-associated B-cell malignancies or facilitate adhesion in the establishment of latency in vivo. IMPORTANCE Epstein-Barr virus (EBV) is a common human herpesvirus that establishes latency in B cells. While EBV infection is asymptomatic for most individuals, immune-suppressed individuals are at significantly higher risk of a form of EBV latent infection in which infected B cells are reactivated, grow unchecked, and generate lymphomas. This form of latency is modeled in the laboratory by infecting B cells from the blood of normal human donors in vitro. In this model, we identified a protein called CD226 that is induced by EBV but is not normally expressed on B cells. Rather, it is known to play a role in aggregation and survival signaling of non-B cells in the immune system. Cultures of EBV-infected cells adhere to one another in “clumps,” and while the proteins that are responsible for this cellular aggregation are not fully understood, we hypothesized that this form of cellular aggregation may provide a survival advantage. In this article, we characterize the mechanism by which EBV induces this protein and its expression on lymphoma tissue and cell lines and characterize EBV-infected cell lines in which CD226 has been knocked out.

scholarly journals Epstein-Barr virus-associated gastric carcinoma in Brazil: comparison between in situ hybridization and polymerase chain reaction detection

2012 ◽  
Vol 43 (1) ◽  
pp. 393-404 ◽  
Author(s):  
Marcos Antonio Pereira de Lima ◽  
Márcia Valéria Pitombeira Ferreira ◽  
Marcos Aurélio Pessoa Barros ◽  
Maria Inês de Moura Campos Pardini ◽  
Adriana Camargo Ferrasi ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
In Situ Hybridization ◽  
Gastric Carcinoma ◽  
Epstein Barr Virus ◽  
Polymerase Chain Reaction Detection ◽  
Chain Reaction ◽  
Barr Virus ◽  
Polymerase Chain ◽  
Epstein Barr

The impact of Epstein-Barr virus status on clinical outcome in diffuse large B-cell lymphoma

Blood ◽  
2007 ◽  
Vol 110 (3) ◽  
pp. 972-978 ◽  
Author(s):  
Sarah Park ◽  
Jeeyun Lee ◽  
Young Hyeh Ko ◽  
Arum Han ◽  
Hyun Jung Jun ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Progression Free Survival ◽  
B Cell Lymphoma ◽  
Free Survival ◽  
Barr Virus ◽  
Large B Cell Lymphoma ◽  
Epstein Barr

AbstractTo define prognostic impact of Epstein-Barr virus (EBV) infection in diffuse large B-cell lymphoma (DLBCL), we investigated EBV status in patients with DLBCL. In all, 380 slides from paraffin-embedded tissue were available for analysis by EBV-encoded RNA-1 (EBER) in situ hybridization, and 34 cases (9.0%) were identified as EBER-positive. EBER positivity was significantly associated with age greater than 60 years (P = .005), more advanced stage (P < .001), more than one extranodal involvement (P = .009), higher International Prognostic Index (IPI) risk group (P = .015), presence of B symptom (P = .004), and poorer outcome to initial treatment (P = .006). The EBER+ patients with DLBCL demonstrated substantially poorer overall survival (EBER+ vs EBER− 35.8 months [95% confidence interval (CI), 0-114.1 months] vs not reached, P = .026) and progression-free survival (EBER+ vs EBER− 12.8 months [95% CI, 0-31.8 months] vs 35.8 months [95% CI, 0-114.1 months], respectively (P = .018). In nongerminal center B-cell–like subtype, EBER in situ hybridization positivity retained its statistical significance at the multivariate level (P = .045). Nongerminal center B-cell–like patients with DLBCL with EBER positivity showed substantially poorer overall survival with 2.9-fold (95% CI, 1.1-8.1) risk for death. Taken together, DLBCL patients with EBER in situ hybridization+ pursued more rapidly deteriorating clinical course with poorer treatment response, survival, and progression-free survival.

Detection of Epstein–Barr virus in children's adenoids by in situ hybridization

2003 ◽  
Vol 1257 ◽  
pp. 157-160 ◽  
Author(s):  
L.H. Endo ◽  
E. Sakano ◽  
L.A. Camargo ◽  
D.R. Ferreira ◽  
G.A. Pinto ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Epstein Barr Virus ◽  
Barr Virus ◽  
Epstein Barr
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