Analysis of Epstein-Barr Virus Infections in Lymphoma Cell Lines.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3906-3906
Author(s):  
Cord C. Uphoff ◽  
Sabine A. Denkmann ◽  
Hans G. Drexler

Abstract Epstein-Barr virus (EBV, human herpesvirus type 4) is ubiquitously distributed in all human populations, reaching infection rates of more than 90%. EBV is known to infect B- lymphocytes and mucosal epithelium cells and to establish latent or productive infections. The virus is the causative agent of infectious mononucleosis and closely associated with the endemic form of Burkitt lymphoma (BL). EBV has also been associated with various lymphoid and epithelial malignancies, such as Hodgkin, T-cell, and AIDS-related lymphomas, and lymphoepithelioma-like carcinomas of several organs. In vitro, B- lymphocytes are transformed by EBV into permanent lymphoblastoid cell lines (B-LCL). We investigated the EBV infection status of primate cell lines by PCR (406 human, 4 monkey). This method detects EBV genomes integrated into the eukaryotic chromosomes, non-integrated EBV episomes, and linear genomes of active EBV particles. The analyses revealed that 38/410 cell lines contain the EBV genome. All EBV+ cell lines were established from B- lineage leukemia/lymphoma cells (13/52 B-non-Hodgkin cell lines, 10/13 BL cell lines, 2/2 hairy cell leukemia cell lines, 1/6 plasma cell leukemia/myeloma cell lines) or are B-LCLs (9/9), natural killer cells (2/2), and one monkey cell line. No cell lines from other tissues were found to be EBV+. To further examine the production of EBV particles in the PCR+ cell lines, we analyzed the expression of the BZLF1 protein by Western blotting applying a ZEBRA monoclonal antibody. The cell lines were analyzed untreated as well as treated with the phorbol ester TPA for 3 days to induce the lytic phase of the EBV infection. Four cell lines exhibited a BZLF1 specific band a priori; after stimulation with TPA, 4 further cell lines expressed BZLF1 protein to various extents. To distinguish between linear DNA of herpesviruses (DNA form of active viruses) and covalently closed circles of episomal DNA, we performed Gardella gels applying crude lysates from cell cultures. Except for cell line NAMALWA and its subclones, DG-75, DOHH-2, and OCI-LY19 (all EBV-PCR+ cell lines) showed at least one band of episomal genomes. Some cell lines showed two episomal bands pointing to a double infection or to mutated episomes. The amount of linear DNA does not correlate with the number of episomes. Southern blots of genomic DNA revealed different genotypes of EBV, except for those cell lines which were established with B95-8 virus particles. To determine distribution of EBV genomes in single cells, we established a fluorescence in situ hybridization (FISH) method with a Cy3-labeled cosmid clone containing a genomic EBV fragment. The method showed for various cell lines that only a few cells contain high amounts of EBV genomes (several hundred) whereas the vast majority harbors only a few genomes in the nuclei. FISH appears to be superior to other methods, allowing for EBV analysis at the single cell level to determine the cellular permissiveness. In summary, we could show that EBV is constitutively produced in a few B-lymphoma derived cell lines and can be induced in several other cell lines. These cell lines represent valuable tools for further investigation into the biology of EBV infection.

2003 ◽  
Vol 77 (7) ◽  
pp. 4139-4148 ◽  
Author(s):  
Honglin Chen ◽  
Lindsey Hutt-Fletcher ◽  
Liang Cao ◽  
S. Diane Hayward

ABSTRACT STAT3 and STAT5 are constitutively activated and nuclear in nasopharyngeal carcinoma (NPC) cells. In normal signaling, STATs are only transiently activated. To investigate whether Epstein-Barr virus (EBV), and in particular the protein LMP1, contributes to sustained STAT phosphorylation and activation in epithelial cells, we examined STAT activity in two sets of paired cell lines, HeLa, an EBV-converted HeLa cell line, HeLa-Bx1, the NPC-derived cell line CNE2-LNSX, and an LMP1-expressing derivative, CNE2-LMP1. EBV infection was associated with a significant increase in the tyrosine-phosphorylated forms of STAT3 and STAT5 in HeLa-Bx1 cells. This effect correlated with LMP1 expression, since phosphorylated STAT3 and STAT5 levels were also increased in CNE2-LMP1 cells relative to the control CNE2-LNSX cells. No change was observed in STAT1 or STAT6 phosphorylation in these cell lines, nor was there a significant change in the levels of total STAT3, STAT5, STAT1, or STAT6 protein. Tyrosine phosphorylation allows the normally cytoplasmic STAT proteins to enter the nucleus and bind to their recognition sequences in responsive promoters. The ability of LMP1 to activate STAT3 was further established by immunofluorescence assays in which coexpression of LMP1 in transfected cells was sufficient to mediate nuclear relocalization of Flag-STAT3 and by an electrophoretic mobility shift assay which showed that LMP1 expression in CNE2-LNSX cells was associated with increased endogenous STAT3 DNA binding activity. In addition, the activity of a downstream target of STAT3, c-Myc, was upregulated in HeLa-Bx1 and CNE2-LMP1 cells. A linkage was established between interleukin-6 (IL-6)- and LMP1-mediated STAT3 activation. Treatment with IL-6 increased phosphorylated STAT3 levels in CNE2-LNSX cells, and conversely, treatment of CNE2-LMP1 cells with IL-6 neutralizing antibody ablated STAT3 activation and c-Myc upregulation. The previous observation that STAT3 activated the LMP1 terminal repeat promoter in reporter assays was extended to show upregulated expression of endogenous LMP1 mRNA and protein in HeLa-Bx1 cells transfected with a constitutively activated STAT3. A model is proposed in which EBV infection of an epithelial cell containing activated STATs would permit LMP1 expression. This in turn would establish a positive feedback loop of IL-6-induced STAT activation, LMP1 and Qp-EBNA1 expression, and viral genome persistence.


1993 ◽  
Vol 177 (2) ◽  
pp. 295-304 ◽  
Author(s):  
N Burdin ◽  
C Péronne ◽  
J Banchereau ◽  
F Rousset

Interleukin 10 (IL-10) is a pleiotropic factor that enhances proliferation of activated human B lymphocytes and induces them to secrete high amounts of immunoglobulins. Here we show that several human B cell lines were able to constitutively secrete human (h)IL-10. Whereas none of the pre-B nor the plasmocytic cell lines tested produced hIL-10, 25 of the 36 tested mature B cell lines (lymphoblastoid and Burkitt lymphoma cell lines) secreted hIL-10. Moreover, 24 of these 25 hIL-10-producing B cell lines contained the Epstein-Barr virus (EBV) genome, suggesting a relationship between hIL-10 production by human B cell lines and EBV expression. Accordingly, whereas polyclonal activation via triggering of surface immunoglobulins or CD40 antigen induced highly purified normal human B lymphocytes to produce only low (0.3-0.4 ng/ml) but significant amounts of hIL-10, EBV infection induced them to secrete high amounts of hIL-10 (4-9 ng/ml). Furthermore, addition of exogenous hIL-10, simultaneously to EBV infection, potentiated cell proliferation, whereas a blocking anti-IL-10 antiserum inhibited it. Thus, hIL-10 produced by infected human B lymphocytes appears to be involved in the mechanisms of EBV-induced B cell proliferation.


mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Lisa Grossman ◽  
Chris Chang ◽  
Joanne Dai ◽  
Pavel A. Nikitin ◽  
Dereje D. Jima ◽  
...  

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.


2019 ◽  
Vol 51 (6) ◽  
pp. 197-207
Author(s):  
Meimei Lai ◽  
Qiongdan Wang ◽  
Yutian Lu ◽  
Xi Xu ◽  
Ying Xia ◽  
...  

Epstein-Barr virus (EBV) is a widespread human virus that establishes latent infection, potentially leading to tumors, hematological disorders, and other severe diseases. EBV infections are associated with diverse symptoms and affect various organs; therefore, early diagnosis and treatment are crucial. B cell receptor (BCR) repertoires of B cell surface immunoglobulins have been widely studied for their association with various infectious diseases. However, the specific genetic changes that modulate the BCR repertoires after an EBV infection are still poorly understood. In this study, we employed high-throughput sequencing (HTS) to investigate the diversity of BCR repertoires in an EBV-transformed lymphoblastic cell line (LCL). Compared with the noninfected control B cell line, the LCL exhibited a decrease in overall BCR diversity but displayed an increase in the expansion of some dominant rearrangements such as IGHV4-31/IGHJ4, IGHV4-59/IGHJ4, IGHV5-51/IGHJ3, and IGHV3-74/IGHJ3. A higher frequency of occurrence of these rearrangement types was confirmed in patients with EBV infection. Interestingly, the IGHV3-74 rearrangement was only detected in EBV-infected children, suggesting that our experimental observations were not coincidental. In addition, we identified a highly dominant consensus motif, CAR(xRx)YGSG(xYx)FD, in complementarity-determining region 3 (CDR3) sequences of the heavy chain in the LCL. Our findings demonstrated the utility of HTS technology for studying the variations in signature motifs of the BCR repertoires after EBV infection. We propose that the analysis of BCR repertoire sequences represents a promising method for diagnosing early EBV infections and developing novel antibody- and vaccine-based therapies against such infections.


2013 ◽  
Vol 94 (3) ◽  
pp. 497-506 ◽  
Author(s):  
Do Nyun Kim ◽  
Min Koo Seo ◽  
Hoyun Choi ◽  
Su Yeon Kim ◽  
Hee Jong Shin ◽  
...  

Epstein–Barr virus (EBV) is a herpesvirus associated with lymphomas and carcinomas. While EBV-associated epithelial cell lines are good model systems to investigate the role of EBV in carcinoma, only a few cell lines are available as they are hard to acquire. A greater variety of naturally EBV-infected cell lines which are derived from tumour patients are needed to represent various features of EBVaGC. We characterized cell line YCCEL1, established from a Korean EBVaGC patient, to ascertain whether it can be used to study the roles of EBV in EBVaGC. The expression of EBV genes and cell surface markers was examined by in situ hybridization, RT-PCR, Western blot analysis, immunofluorescence assay and Northern blot analysis. EBV episomal status was analysed by Southern blotting and real-time PCR. This cell line expressed EBV nuclear antigen 1 (EBNA1) and latent membrane protein 2A (LMP2A), but not EBNA2, LMP2B nor LMP1. The majority of the lytic proteins were not detected in YCCEL1 cells either before or after treatment with 12-O-tetradecanoylphorbol-13-acetate. YCCEL1 cells expressed BART microRNAs (miRNAs) at high level but did not express BHRF1 miRNAs. YCCEL1 cells expressed cytokeratin, but not CD21 and CD19, suggesting CD21-independent EBV infection. The latent EBV gene and EBV miRNA expression pattern of YCCEL1 cells closely resembled that of general EBVaGC cases. Our results support the value of YCCEL1 cells as a good model system to study the role of EBV in gastric carcinogenesis.


2000 ◽  
Vol 74 (2) ◽  
pp. 735-743 ◽  
Author(s):  
Andrew J. Aguirre ◽  
Erle S. Robertson

ABSTRACT Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are human gammaherpesviruses associated with numerous malignancies. Primary effusion lymphoma or body cavity-based lymphoma is a distinct clinicopathological entity that, in the majority of cases, manifests coinfection with KSHV and EBV. In previous analyses, we have characterized the EBV in the BC-1 and BC-2 cell lines as potential intertypic recombinants of the EBV types 1 and 2. In order to examine the infectious and transforming capacities of KSHV and the intertypic EBV recombinants from the BC-1 and BC-2 cell lines, viral replication was induced in these cell lines and fresh human primary B lymphocytes were infected with progeny virus. The transformed clones were analyzed by PCR and Western blotting. All analyzed clones were infected with the intertypic progeny EBV but had no detectable signal for progeny KSHV. Additionally, primary B lymphocytes incubated with viral supernatant containing KSHV alone showed an unsustained initial proliferation, but prolonged growth or immortalization of these cells in vitro was not observed. We also show that the EBV recombinants from BC-1 were less efficient than the EBV recombinants from BC-2 in the ability to maintain the transformed phenotype of the infected human B lymphocytes. From these findings, we conclude that the BC-1 and BC-2 intertypic EBV recombinants can immortalize human primary B lymphocytes, albeit at different levels of efficiency. However, the KSHV induced from BC-1 and BC-2 alone cannot transform primary B cells, nor can it coinfect EBV-positive B lymphocytes under our experimental conditions with B lymphocytes from EBV-seropositive individuals. These results are distinct from those in one previous report and suggest a possible requirement for other factors to establish coinfection with both viral agents.


1971 ◽  
Vol 7 (3) ◽  
pp. 375-379 ◽  
Author(s):  
German Beltran ◽  
James W. Northington ◽  
Eduardo Leiderman ◽  
William J. Mogabgab ◽  
Walter J. Stuckey

2021 ◽  
Vol 49 (18) ◽  
pp. 10657-10676
Author(s):  
Evelyne Manet ◽  
Hélène Polvèche ◽  
Fabrice Mure ◽  
Paulina Mrozek-Gorska ◽  
Florian Roisné-Hamelin ◽  
...  

Abstract Epstein-Barr virus (EBV) is a human herpesvirus associated with human cancers worldwide. Ex vivo, the virus efficiently infects resting human B lymphocytes and induces their continuous proliferation. This process is accompanied by a global reprogramming of cellular gene transcription. However, very little is known on the impact of EBV infection on the regulation of alternative splicing, a pivotal mechanism that plays an essential role in cell fate determination and is often deregulated in cancer. In this study, we have developed a systematic time-resolved analysis of cellular mRNA splice variant expression during EBV infection of resting B lymphocytes. Our results reveal that major modifications of alternative splice variant expression appear as early as day 1 post-infection and suggest that splicing regulation provides—besides transcription—an additional mechanism of gene expression regulation at the onset of B cell activation and proliferation. We also report a role for the viral proteins, EBNA2 and EBNA-LP, in the modulation of specific alternative splicing events and reveal a previously unknown function for EBNA-LP—together with the RBM4 splicing factor—in the alternative splicing regulation of two important modulators of cell proliferation and apoptosis respectively, NUMB and BCL-X.


Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1619-1623 ◽  
Author(s):  
S Doi ◽  
H Ohno ◽  
E Tatsumi ◽  
Y Arita ◽  
H Kamesaki ◽  
...  

Abstract A novel cell line, FL-18, was established from the pleural effusion of a patient with follicular small cleaved cell lymphoma. At the same time, an Epstein-Barr virus (EBV) nuclear antigen (EBNA)-positive cell line, FL-18-EB, was established from the EBV-infected culture of the same pleural effusion cells. Both cell lines had the same monoclonal surface immunoglobulin (IgG kappa), and they had the same karyotype as that of the fresh pleural effusion cells in which a reciprocal translocation between the long arm of chromosomes 14 and 18 [t(14;18)(q32;q21)] was detected. Gene rearrangement analysis of immunoglobulin heavy-chain gene (JH) and kappa light-chain gene (J kappa) showed the same rearranged configuration in the two cell lines; however, some morphological and phenotypic differences were found. The FL-18-EB cells, which were morphologically similar to common EBNA- positive lymphoblastoid cell lines of normal B cell origin at the initial phase of culture, were larger than the FL-18 cells and contained multinucleated giant cells. The FL-18 cells lacked cytoplasmic immunoglobulin and were positive for common acute lymphoblastic leukemia antigen (CALLA), whereas the FL-18-EB cells had cytoplasmic immunoglobulin and were negative for CALLA. Thus, the phenotype of FL-18-EB seems to be a result of a shift by EBV infection to a more mature stage in the B cell differentiation pathway than that of FL-18. The paired availability of EBV-free and EBV-infected cell lines of a neoplastic clone is unique and valuable in considering EBV infectibility of neoplastic B cells and resultant phenotypic changes.


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