scholarly journals Extracellular Vesicles in Epstein-Barr Virus’ Life Cycle and Pathogenesis

2019 ◽  
Vol 7 (2) ◽  
pp. 48 ◽  
Author(s):  
Mengmeng Zhao ◽  
Asuka Nanbo ◽  
Lichun Sun ◽  
Zhen Lin

Extracellular vesicles (EVs), including exosomes and microvesicles, are evolutionarily conserved phospholidpid membrane-bound entities secreted from most eukaryotic cell types. They carry bioactive cargos such as protein and nucleic acids derived from their cells of origin. Over the past 10 years, they have been attracting increased attention in many fields of life science, representing a new route for intercellular communication. In this review article, we will discuss the current knowledge of both normal and virally modified EVs in the regulation of Epstein-Barr virus (EBV)’s life cycle and its associated pathogenesis.

2019 ◽  
Vol 6 (5) ◽  
Author(s):  
Peiling Zhang ◽  
Chen Zeng ◽  
Jiali Cheng ◽  
Jing Zhou ◽  
Jia Gu ◽  
...  

Abstract Background High loads of Epstein-Barr virus (EBV) in peripheral blood mononuclear cells (PBMCs) can be indicative of a broad spectrum of diseases, ranging from asymptomatic infection to fatal cancers. Methods We retrospectively investigated the EBV-infected cell types in PBMCs among 291 patients. Based on EBV-infected cell types, the clinical features and prognoses of 93 patients with EBV-associated (EBV+) T/natural killer (NK)–cell lymphoproliferative diseases (LPDs) T/NK-LPDs) were investigated over a 5-year period. Results Although B-cell-type infection was found in immunocompromised patients and patients with asymptomatic high EBV carriage, infectious mononucleosis, EBV+ B-cell LPDs and B-cell lymphomas, T-cell, NK-cell or multiple-cell-type infection in immunocompetent hosts were highly suggestive of EBV+ T/NK-LPDs, EBV+ T/NK-cell lymphomas, and aggressive NK-cell leukemia. Patients with non–B-cell infection had a poorer prognosis than those with B-cell-type infection. In our cohort, 79.6% of patients with EBV+ T/NK-LPDs were >18 years old, and NK cells were identified as EBV-infected cell type in 54.8%. Nearly half of patients with EBV+ T/NK-LPDs had genetic defects associated with immunodeficiency. However, hemophagocytic lymphohistiocytosis, and not genetic defects, was the only parameter correlated with poor prognosis of EBV+ T/NK-LPDs. Conclusions Determination of EBV-infected cell types among PBMCs is a valuable tool for the differential diagnosis of EBV+ hematological diseases. In this study, determination of Epstein-Barr virus-infected cell types in peripheral blood mononuclear cells of 291 patients with high Epstein-Barr virus loads were retrospectively investigated, which indicate it is a valuable tool for Epstein-Barr virus-associated hematological diseases.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hyojin Song ◽  
Yoojoo Lim ◽  
Hogune Im ◽  
Jeong Mo Bae ◽  
Gyeong Hoon Kang ◽  
...  

2004 ◽  
Vol 78 (10) ◽  
pp. 4983-4992 ◽  
Author(s):  
Gregory K. Hong ◽  
Henri-Jacques Delecluse ◽  
Henri Gruffat ◽  
Thomas E. Morrison ◽  
Wen-Hai Feng ◽  
...  

ABSTRACT The switch from the latent to the lytic form of Epstein-Barr virus (EBV) infection is mediated by expression of the viral immediate-early (IE) proteins, BZLF1 (Z) and BRLF1 (R). An EBV early protein, BRRF1 (Na), is encoded by the opposite strand of the BRLF1 intron, but the function of this nuclear protein in the viral life cycle is unknown. Here we demonstrate that Na enhances the R-mediated induction of lytic EBV infection in 293 cells latently infected with a recombinant EBV (R-KO) defective for the expression of both R and Na. Na also enhances R-induced lytic infections in a gastric carcinoma line (AGS) carrying the R-KO virus, although it has no effect in a Burkitt lymphoma line (BL-30) stably infected with the same mutant virus. We show that Na is a transcription factor that increases the ability of R to activate Z expression from the R-KO viral genome in 293 cells and that Na by itself activates the Z promoter (Zp) in EBV-negative cells. Na activation of Zp requires a CRE motif (ZII), and a consensus CRE motif is sufficient to transfer Na responsiveness to the heterologous E1b promoter. Furthermore, we show that Na enhances the transactivator function of a Gal4-c-Jun fusion protein but does not increase the transactivator function of other transcription factors (including ATF-1, ATF-2, and CREB) known to bind CRE motifs. Na expression in cells results in increased levels of a hyperphosphorylated form of c-Jun, suggesting a mechanism by which Na activates c-Jun. Our results indicate that Na is a transcription factor that activates the EBV Zp IE promoter through its effects on c-Jun and suggest that Na cooperates with BRLF1 to induce the lytic form of EBV infection in certain cell types.


2013 ◽  
Vol 94 (12) ◽  
pp. 2750-2758 ◽  
Author(s):  
Yi-Ru Liu ◽  
Sheng-Yen Huang ◽  
Jen-Yang Chen ◽  
Lily Hui-Ching Wang

Elevated levels of antibodies against Epstein–Barr virus (EBV) and the presence of viral DNA in plasma are reliable biomarkers for the diagnosis of nasopharyngeal carcinoma (NPC) in high-prevalence areas, such as South-East Asia. The presence of these viral markers in the circulation suggests that a minimal level of virus reactivation may have occurred in an infected individual, although the underlying mechanism of reactivation remains to be elucidated. Here, we showed that treatment with nocodazole, which provokes the depolymerization of microtubules, induces the expression of two EBV lytic cycle proteins, Zta and EA-D, in EBV-positive NPC cells. This effect was independent of mitotic arrest, as viral reactivation was not abolished in cells synchronized at interphase. Notably, the induction of Zta by nocodazole was mediated by transcriptional upregulation via protein kinase C (PKC). Pre-treatment with inhibitors for PKC or its downstream signalling partners p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) abolished the nocodazole-mediated induction of Zta and EA-D. Interestingly, the effect of nocodazole, as well as colchicine and vinblastine, on lytic gene expression occurred only in NPC epithelial cells but not in cells derived from lymphocytes. These results establish a novel role of microtubule integrity in controlling the EBV life cycle through PKC and its downstream pathways, which represents a tissue-specific mechanism for controlling the life-cycle switch of EBV.


2018 ◽  
Vol 9 ◽  
Author(s):  
Andrzej Górski ◽  
Ryszard Międzybrodzki ◽  
Ewa Jończyk-Matysiak ◽  
Beata Weber-Dąbrowska ◽  
Natalia Bagińska ◽  
...  

2015 ◽  
Vol 89 (10) ◽  
pp. 5200-5203 ◽  
Author(s):  
David G. Meckes

Exosomes are small vesicles secreted from cells that participate in intercellular communication events. Accumulating evidence demonstrates that host exosome pathways are hijacked by viruses and that virally modified exosomes contribute to virus spread and immune evasion. In the case of tumor viruses, recent findings suggest that alterations in normal exosome biology may promote the development and progression of cancer. These studies will be discussed in the context of our current knowledge of Epstein-Barr virus (EBV)-modified exosomes.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qian-Ying Zhu ◽  
Sisi Shan ◽  
Jinfang Yu ◽  
Si-Ying Peng ◽  
Cong Sun ◽  
...  

AbstractEpstein-Barr virus (EBV) is associated with a range of epithelial and B cell malignancies as well as autoimmune disorders, for which there are still no specific treatments or effective vaccines. Here, we isolate EBV gH/gL-specific antibodies from an EBV-infected individual. One antibody, 1D8, efficiently neutralizes EBV infection of two major target cell types, B cells and epithelial cells. In humanized mice, 1D8 provides protection against a high-dose EBV challenge by substantially reducing viral loads and associated tumor burden. Crystal structure analysis reveals that 1D8 binds to a key vulnerable interface between the D-I/D-II domains of the viral gH/gL protein, especially the D-II of the gH, thereby interfering with the gH/gL-mediated membrane fusion and binding to target cells. Overall, we identify a potent and protective neutralizing antibody capable of reducing the EBV load. The novel vulnerable site represents an attractive target that is potentially important for antibody and vaccine intervention against EBV infection.


2018 ◽  
Author(s):  
Romina C. Vargas-Ayala ◽  
Antonin Jay ◽  
Hector Hernandez-Vargas ◽  
Audrey Diederichs ◽  
Alexis Robitaille ◽  
...  

AbstractHistone modifier lysine (K)-specific demethylase 2B(KDM2B) plays a role in hematopoietic cells differentiation and its expression appears to be deregulated in certain cancers of hematological and lymphoid origins. We have previously found that KDM2B gene is differentially methylated in cell lines derived from the Epstein-Barr virus (EBV) associated endemic Burkitt’s lymphomas (eBL) compared to EBV negative sporadic BL cells. However, whether KDM2B plays a role in eBL development has never been previously demonstrated. Oncogenic viruses have been shown to hijack the host cell epigenome to complete their life cycle and to promote the transformation process by perturbing cell chromatin organization. Here we investigated whether EBV would alter KDM2B levels to enable its life cycle and promote B-cells transformation. We show that infection of B-cells with EBV leads to down-regulation of KDM2B levels. We also show that LMP1, one of the main EBV transforming proteins, induces increased DNMT1 recruitment to KDM2B gene and augments its methylation. By altering KDM2B levels and performing chromatin immunoprecipitation in EBV infected B-cells, we were able to show that KDM2B is recruited to the EBV gene promoters and inhibits their expression. Furthermore, forced KDM2B expression in immortalized B-cells led to altered mRNA levels of some differentiation-related genes. Our data show that EBV deregulates KDM2B levels through an epigenetic mechanism and provide evidence for a role of KDM2B in regulating virus and host cell gene expression, warranting further investigations to assess the role of KDM2B in the process of EBV-mediated lymphomagenesis.IMPORTANCE. In Africa, Epstein-Barr virus infection is associated with endemic Burkitt lymphoma, a pediatric cancer. The molecular events leading to its development are poorly understood compared to the sporadic Burkitt lymphoma. In a previous study, by analyzing the DNA methylation changes in endemic compared to sporadic Burkitt lymphomas cell lines, we identified several differential methylated genomic positions in proximity of genes with a potential role in cancer, among them the KDM2B gene. KDM2B encodes a histone H3 demethylase already shown to be involved in some hematological disorders. However, whether KDM2B plays a role in the development of Epstein-Barr virus-mediated lymphoma has never been investigated before. In this study we show that Epstein-Barr virus deregulates KDM2B expression and describe the underlying mechanisms. We also reveal a role of the demethylase in controlling viral and B-cells genes expression, thus highlighting a novel interaction between the virus and the cellular epigenome.


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