Length of Epstein-Barr virus termini as a determinant of epithelial cell clonal emergence.
Ontology highlight
ABSTRACT:
SUBMITTER: Moody CA
PROVIDER: S-EPMC165260 | biostudies-literature | 2003 Aug
REPOSITORIES: biostudies-literature
Publications
Length of Epstein-Barr virus termini as a determinant of epithelial cell clonal emergence.
Moody Cary A CA Scott Rona S RS Su Tao T Sixbey John W JW
Journal of virology 20030801 15
Reiterated terminal sequences of Epstein-Barr virus (EBV) DNA are numerically heterogeneous among infectious virions, providing a viral measure of clonality in infected cells. After in vitro infection, carcinoma cells bearing EBV episomes with fewer terminal repeats (TRs) proliferated faster. In single-cell clones, TR number varied inversely to the quantity of latent membrane protein 2A (LMP2A) transcripts whose unspliced precursors cross joined TRs. Thus, EBV clonality may reflect selection for ...[more]
Similar Datasets
Project description:The Epstein-Barr virus (EBV) is associated with angioimmunoblastic T cell lymphoma (AITL), a peripheral T lymphoma of poor prognosis in at least 90% of cases. The role of EBV in this pathology is unknown. Using next-generation sequencing, we sequenced the entire EBV genome in biopsies from 18 patients with AITL, 16 patients with another EBV-associated lymphoma, and 2 controls. We chose an EBV target capture method, given the high specificity of this technique, followed by a second capture to increase sensitivity. We identified two main viral strains in AITL, one of them associated with the mutations BNRF1 S542N and BZLF1 A206S and with mutations in the EBNA-3 and LMP-2 genes. This strain was characterized in patients with short post-diagnosis survival. The main mutations found during AITL on the most mutated latency or tegument genes were identified and discussed. We showed that the virus was clonal in all the AITL samples, suggesting that it may be involved in this pathology. Additionally, EBV was latent in all the AITL samples; for one sample only, the virus was found to be latent and probably replicative, depending on the cells. These various elements support the role of EBV in AITL.
| S-EPMC9221046 | biostudies-literature
Project description:The main target cells for Epstein-Barr virus (EBV) infection and persistence are B lymphocytes, although T and NK cells can also become infected. In this paper, we characterize the EBV present in 21 pediatric and adult patients who were treated in France for a range of diseases that involve infection of T or NK cells. Of these 21 cases, 5 pediatric patients (21%) and 11 adult patients (52%) were of Caucasian origin. In about 30% of the cases, some of the EBV genomes contain a large deletion. The deletions are different in every patient but tend to cluster near the BART region of the viral genome. Detailed investigation of a family in which several members have persistent T or NK cell infection by EBV indicates that the virus genome deletions arise or are selected independently in each individual patient. Genome sequence polymorphisms in the EBV in these T or NK cell diseases reflect the geographic origin of the patient and not a distinct type of EBV (the 21 cases studied included examples of both type 1 and type 2 EBV infection). Using virus produced from type 1 or type 2 EBV genomes cloned in bacterial artificial chromosome (BAC) vectors, we demonstrate infection of T cells in cord blood from healthy donors. Our results are consistent with transient infection of some T cells being part of normal asymptomatic infection by EBV in young children. IMPORTANCE EBV contributes to several types of human cancer. Some cancers and nonmalignant lymphoproliferative diseases involving T or NK cells contain EBV. These diseases are relatively frequent in Japan and China and have been shown sometimes to have deletions in the EBV genome in the disease cells. We identify further examples of deletions within the EBV genome associated with T or NK cell diseases, and we provide evidence that the virus genomes with these deletions are most likely selected in the individual cases, rather than being transmitted between people during infection. We demonstrate EBV infection of cord blood T cells by highly characterized, cloned EBV genomes and suggest that transient infection of T cells may be part of normal asymptomatic infection by EBV in young children.
| S-EPMC9215254 | biostudies-literature
Project description:Reduced IRF4 expression promotes lytic phenotype in Type 2 EBV-infected B cells
| PRJNA794826 | ENA
Project description:Epstein-Barr virus (EBV) is an important human dsDNA virus, which has been shown to be associated with several malignancies including about 10% of gastric carcinomas. How EBV enters an epithelial cell has been an interesting project for investigation. "Cell-in-cell" infection was recently reported an efficient way for the entry of EBV into nasopharynx epithelial cells. The present approach was to explore the feasibility of this mode for EBV infection in gastric epithelial cells and the dynamic change of host inflammatory reaction. The EBV-positive lymphoblastic cells of Akata containing a GFP tag in the viral genome were co-cultured with the gastric epithelial cells (GES-1). The infection situation was observed under fluorescence and electron microscopies. Real-time quantitative PCR and Western-blotting assay were employed to detect the expression of a few specific cytokines and inflammatory factors. The results demonstrated that EBV could get into gastric epithelial cells by "cell-in-cell" infection but not fully successful due to the host fighting. IL-1β, IL-6 and IL-8 played prominent roles in the cellular response to the infection. The activation of NF-κB and HSP70 was also required for the host antiviral response. The results imply that the gastric epithelial cells could powerfully resist the virus invader via cell-in-cell at the early stage through inflammatory and innate immune responses.
| S-EPMC6599502 | biostudies-literature
Project description:Northern blot analysis of the Epstein-Barr virus DNA polymerase mRNA identified two discrete sizes of virally encoded polymerase transcripts, 5.08 kb detected in strains P3HR1, Raji, W-91, and FF-41 and 3.7 kb detected solely in the prototype B95-8 strain. 3' S1-nuclease mapping and analysis of cDNA sequence generated by RNA-based PCR demonstrated that the 3.7-kb polymerase mRNA from B95-8 terminates 484 base pairs downstream of the open reading frame in a region of the genome remarkable for its lack of an apparent polyadenylylation signal. Moreover, between the cleavage point and the poly(A) tract of the cDNAs are a series of inserted nucleotides, mostly adenosine and uridine residues of unknown origin. A similar analysis of the 3' terminus of the 5.0-kb mRNA from the other cell lines revealed that polyadenylylation occurs 1.4 kb downstream of the B95-8 terminus. This region is deleted in B95-8, which accounts for the alternate upstream terminus used in B95-8. Like the 3.7-kb terminus, the 5.0-kb terminus lacks a canonical polyadenylylation signal, but contains a rarely used UAUAAA sequence 32 bp upstream of the poly(A) tail. These results indicate that the mRNA encoded by the Epstein-Barr virus DNA polymerase gene is polyadenylylated at two different termini without the use of canonical signals, raising the possibility of involvement of a virus-encoded factor in 3' processing of this message.
| S-EPMC45665 | biostudies-other
Project description:Epstein-Barr virus (EBV) is a human herpesvirus that causes infectious mononucleosis and contributes to both B-cell and epithelial-cell malignancies. EBV-infected epithelial cell tumors, including nasopharyngeal carcinoma (NPC), are largely composed of latently infected cells, but the mechanism(s) maintaining viral latency are poorly understood. Expression of the EBV BZLF1 (Z) and BRLF1 (R) encoded immediate-early (IE) proteins induces lytic infection, and these IE proteins activate each other's promoters. ΔNp63α (a p53 family member) is required for proliferation and survival of basal epithelial cells and is over-expressed in NPC tumors. Here we show that ΔNp63α promotes EBV latency by inhibiting activation of the BZLF1 IE promoter (Zp). Furthermore, we find that another p63 gene splice variant, TAp63α, which is expressed in some Burkitt and diffuse large B cell lymphomas, also represses EBV lytic reactivation. We demonstrate that ΔNp63α inhibits the Z promoter indirectly by preventing the ability of other transcription factors, including the viral IE R protein and the cellular KLF4 protein, to activate Zp. Mechanistically, we show that ΔNp63α promotes viral latency in undifferentiated epithelial cells both by enhancing expression of a known Zp repressor protein, c-myc, and by decreasing cellular p38 kinase activity. Furthermore, we find that the ability of cis-platinum chemotherapy to degrade ΔNp63α contributes to the lytic-inducing effect of this agent in EBV-infected epithelial cells. Together these findings demonstrate that the loss of ΔNp63α expression, in conjunction with enhanced expression of differentiation-dependent transcription factors such as BLIMP1 and KLF4, induces lytic EBV reactivation during normal epithelial cell differentiation. Conversely, expression of ΔNp63α in undifferentiated nasopharyngeal carcinoma cells and TAp63α in Burkitt lymphoma promotes EBV latency in these malignancies.
| S-EPMC8601603 | biostudies-literature
Project description:Epstein-Barr virus (EBV) is a human oncogenic virus that causes several types of tumor, such as Burkitt's lymphoma and nasopharyngeal carcinoma (NPC). NPC tumor cells are clonal expansions of latently EBV-infected epithelial cells. However, the mechanisms by which EBV transforms the nasopharyngeal epithelium is hampered, because of the lack of good in vitro model to pursue oncogenic process. Our primary nasopharyngeal epithelial cell cultures developed pseudostratified epithelium at the air-liquid interface, which was susceptible to EBV infection. Using the highly sensitive RNA in situ hybridization technique, we detected viral infection in diverse cell types, including ciliated cells, goblet cells, and basal cells. EBV-encoded small RNA-positive cells were more frequently detected in the suprabasal layer than in the basal layer. We established the most physiologically relevant EBV infection model of nasopharyngeal epithelial cells. This model will advance our understanding of EBV pathogenesis in the development of NPC.
| S-EPMC7564236 | biostudies-literature
Project description:Whether the human tumor virus, Epstein-Barr Virus (EBV), promotes breast cancer remains controversial and a potential mechanism has remained elusive. Here we show that EBV can infect primary mammary epithelial cells (MECs) that express the receptor CD21. EBV infection leads to the expansion of early MEC progenitor cells with a stem cell phenotype, activates MET signaling and enforces a differentiation block. When MECs were implanted as xenografts, EBV infection cooperated with activated Ras and accelerated the formation of breast cancer. Infection in EBV-related tumors was of a latency type II pattern, similar to nasopharyngeal carcinoma (NPC). A human gene expression signature for MECs infected with EBV, termed EBVness, was associated with high grade, estrogen-receptor-negative status, p53 mutation and poor survival. In 11/33 EBVness-positive tumors, EBV-DNA was detected by fluorescent in situ hybridization for the viral LMP1 and BXLF2 genes. In an analysis of the TCGA breast cancer data EBVness correlated with the presence of the APOBEC mutational signature. We conclude that a contribution of EBV to breast cancer etiology is plausible, through a mechanism in which EBV infection predisposes mammary epithelial cells to malignant transformation, but is no longer required once malignant transformation has occurred.
| S-EPMC4972522 | biostudies-literature
Project description:UnlabelledThe Epstein-Barr virus (EBV) encodes its own microRNAs (miRNAs); however, their biological roles remain elusive. The commonly used EBV B95-8 strain lacks a 12-kb genomic region, known as BamHI A rightward transcripts (BART) locus, where a number of BART miRNAs are encoded. Here, bacterial artificial chromosome (BAC) technology was used to generate an EBV B95-8 strain in which the 12-kb region was fully restored at its native locus [BART(+) virus]. Epithelial cells were stably infected with either the parental B95-8 virus or the BART(+) virus, and BART miRNA expression was successfully reconstituted in the BART(+) virus-infected cells. Microarray analyses of cellular gene expression identified N-myc downstream regulated gene 1 (NDRG1) as a putative target of BART miRNAs. The NDRG1 protein was barely expressed in B cells, highly expressed in epithelial cells, including primary epithelial cells, and strongly downregulated in the BART(+) virus-infected epithelial cells of various origins. Although in vitro reporter assays identified BART22 as being responsible for the NDRG1 downregulation, EBV genetic analyses revealed that BART22 was not solely responsible; rather, the entire BART miRNA cluster 2 was responsible for the downregulation. Immunohistochemical analyses revealed that the expression level of the NDRG1 protein was downregulated significantly in EBV-positive nasopharyngeal carcinoma specimens. Considering that NDRG1 encodes an epithelial differentiation marker and a suppressor of metastasis, these data implicate a causative relationship between BART miRNA expression and epithelial carcinogenesis in vivo.ImportanceEBV-related epithelial cancers, such as nasopharyngeal carcinomas and EBV-positive gastric cancers, encompass more than 80% of EBV-related malignancies. Although it is known that they express high levels of virally encoded BART miRNAs, how these miRNAs contribute to EBV-mediated epithelial carcinogenesis remains unknown. Although a number of screenings have been performed to identify targets of viral miRNAs, many targets likely have not been identified, especially in case of epithelial cell infection. This is the first study to use EBV genetics to perform unbiased screens of cellular genes that are differentially expressed in viral miRNA-positive and -negative epithelial cells. The result indicates that multiple EBV-encoded miRNAs cooperatively downregulate NDRG1, an epithelial differentiation marker and suppressor of metastasis. The experimental system described in this study should be useful for further clarifying the mechanism of EBV-mediated epithelial carcinogenesis.
| S-EPMC4325718 | biostudies-literature
Project description:BackgroundHuman herpesvirus-8 (HHV8) is a lymphotropic virus associated with different lymphoproliferative disorders, including primary effusion lymphoma (PEL), multicentric Castleman's disease (MCD), diffuse large B-cell lymphomas, not otherwise specified, and the rare entity known as germinotropic lymphoproliferative disorder (GLPD). In PELs and GLPD the neoplastic cells also contain Epstein-Barr virus (EBV). In addition, occasional cases with atypical and overlapping features among these entities have been recognised, suggesting that the spectrum of the HHV8-related lesions may not be fully characterised.AimsHere, we report two cases of lymphoproliferative disorder associated with HHV8 and EBV that further expand the spectrum of HHV8/EBV-positive lymphoproliferative disease.Methods and resultsCase 1 represented HHV8/EBV-positive extracavitary nodal PEL followed by pleural PEL. The striking characteristic of this case was the almost focal and intrasinusoidal localisation of the neoplastic cells and the association with Castleman's disease features. In the second case, we found the entire spectrum of HHV8-related disorders, i.e. MCD, GLPD, and PEL, coexisting in the same lymph node, underlining the variability, possible overlap and evolution among these entities. Both cases were well analysed with immunohistochemistry, determination of the EBV latency programme, and molecular analysis for clonality of immnoglobulin genes. In both patients, the disease followed an unexpected indolent course, both being still alive after 8 and 12 months, respectively.ConclusionOur findings represent further evidence of the overlap among HHV8/EBV-positive lymphoproliferative disorders, and underline a grey zone that requires further study; they further confirm the experimental evidence that lytic EBV replication influences HHV8-related tumorigenesis.
| S-EPMC9293042 | biostudies-literature