Project description:Proteomic analysis of cytokines in unstimulated oropharyngeal secretions. Epstein-barr virus (EBV) is a type 1 carcinogen which causes many cancers in humans. Here we explored the cytokine involvement of the EBV replication process in the oropharynx. Cytokine interactomic profiles were geneerated to understand the involved signalling pathways in HIV infected group and the healthy group. Proteome profilers were used to understand the major cytokine expression levels that are related to infection and immune regulation. We analyzed unstimulated oropharyngeal samples (UOPS) from 42 healthy subjects and 72 HIV positive subjects using the R & D Proteome Profiler array panels. No techinical replicates were performed. 14 samples in HIV group without therapy (NHAART group); 58 HIV patients with highly active antiretroviral therapy (HAART group); 42 samples in healthy group
Project description:Proteomic analysis of cytokines in unstimulated oropharyngeal secretions. Epstein-barr virus (EBV) is a type 1 carcinogen which causes many cancers in humans. Here we explored the cytokine involvement of the EBV replication process in the oropharynx. Cytokine interactomic profiles were geneerated to understand the involved signalling pathways in HIV infected group and the healthy group. Proteome profilers were used to understand the major cytokine expression levels that are related to infection and immune regulation.
Project description:Epstein-Barr virus (EBV) causes infectious mononucleosis, triggers multiple sclerosis and is associated with 200,000 cancers/year. EBV colonizes the B-cell compartment and periodically reactivates, inducing expression of 80 viral proteins. Yet much remains unknown about how EBV remodels host cells and dismantles key antiviral responses. We therefore created a proteomic map of EBV-host and EBV-EBV interactions in B-cells undergoing EBV replication, uncovering conserved herpesvirus versus EBV-specific host cell targets. The EBV-encoded G-protein coupled receptor BILF1 associated with MAVS and the UFM1 E3 ligase UFL1. Whereas UFMylation of 14-3-3 proteins drives RIG-I/MAVS signaling, BILF1-directed MAVS UFMylation instead triggered MAVS packaging into mitochondrial-derived vesicles and lysosomal proteolysis. In the absence of BILF1, EBV replication activated the NLRP3 inflammasome, which impaired viral replication and triggered pyroptosis. Our results provide a viral protein interaction network resource, reveal a UFM1-dependent pathway for selective degradation of mitochondrial cargo and highlight BILF1 as a novel therapeutic target.
Project description:The human gamma herpesvirus Epstein-Barr virus, infects most adults and is an important contributor to the development of many types of cancer. Essential contributions of viral genes to replication are known but the potential contributions of cell genes to viral replication are less well delineated. A key player is the viral protein Zta (BZLF1, ZEBRA, Z). This sequence-specific DNA-binding protein can disrupt viral latency by driving the transcription of target genes and by interacting with the EBV lytic origin of replication. Here we used an unbiased approach to identify the Zta-interactome in cells derived from a Burkitt’s lymphoma. Isolating Zta and associated proteins from Burkitt’s lymphoma cells undergoing EBV replication, followed by Tandem Mass Tag (TMT) mass spectrometry resulted in the identification of forty-four viral and cellular proteins in the Zta interactome. Of these two were known targets of Zta. The association of Zta with Hsc70 and the contribution that Hsc70 plays to EBV replication mirrors a contribution from HSP70 family members to the replication of other herpesviruses. Conversely, the association of Zta with NFATc2 has no known parallels for other herpesviruses. Zta attenuates the activity of an NFAT-dependent promoter, which shows a potential for dampening the expression of genes regulated by calcium-dependent signal transduction. Indeed, Zta has the ability to affect a feed-back loop limiting its own expression, which would aid viral replication by preventing the toxic effects of Zta overexpression.
Project description:Epstein Barr virus (EBV) replication contributes to multiple human diseases, including infectious mononucleosis, nasopharyngeal carcinoma, B-cell lymphomas, and oral hairy leukoplakia. We performed systematic quantitative analyses of temporal changes in host and EBV proteins during lytic replication to gain novel insights into virus-host interactions, using conditional Burkitt lymphoma models of type I and II EBV infection. We quantified profiles of >8000 cellular and 69 EBV proteins, including >500 plasma membrane proteins, providing temporal views of the lytic B-cell proteome and EBV virome. Our approach revealed EBV-induced remodelling of cell cycle, innate and adaptive immune pathways, including upregulation of the complement cascade and proteasomal degradation of the B-cell receptor complex, conserved between EBV types I and II. Cross-comparison with proteomic analyses of human cytomegalovirus infection and of a Kaposi sarcoma associated herpesvirus immunoevasin identified host factors targeted by multiple herpesviruses. Our results provide an important resource for studies of EBV replication.
Project description:Epstein Barr virus (EBV) replication contributes to multiple human diseases, including infectious mononucleosis, nasopharyngeal carcinoma, B-cell lymphomas, and oral hairy leukoplakia. We performed systematic quantitative analyses of temporal changes in host and EBV proteins during lytic replication to gain novel insights into virus-host interactions, using conditional Burkitt lymphoma models of type I and II EBV infection. We quantified profiles of >8000 cellular and 69 EBV proteins, including >500 plasma membrane proteins, providing temporal views of the lytic B-cell proteome and EBV virome. Our approach revealed EBV-induced remodelling of cell cycle, innate and adaptive immune pathways, including upregulation of the complement cascade and proteasomal degradation of the B-cell receptor complex, conserved between EBV types I and II. Cross-comparison with proteomic analyses of human cytomegalovirus infection and of a Kaposi sarcoma associated herpesvirus immunoevasin identified host factors targeted by multiple herpesviruses. Our results provide an important resource for studies of EBV replication.
Project description:MicroRNAs (miRNAs) are a class of small RNA molecules previously known to function as post-transcriptional regulators in multiple cellular processes. Here, we show that a human cellular miRNA, hsa-miR-155, can regulate the latent replication origin (oriP) of Epstein-Barr virus (EBV) by competing with Epstein-Barr nuclear antigen 1 (EBNA-1) for direct binding to the dyad symmetry (DS) sequence on the oriP, and thus regulate the function of the DNA replication origin. When this direct binding was abolished by introducing a mutation into the hsa-miR-155 or DS sequence, replication resumed. Furthermore, endogenous hsa-miR-155 could target specifically to the EBV genomic replication origin in EBV type I-latently infected cells and regulate the viral DNA replication. Our discovery represents a hitherto undiscovered and important function of miRNA for the control of DNA replication, and demonstrates a probable mechanism of how this can be achieved using the latent replication origin of EBV.
Project description:Epstein-Barr virus (EBV) has a lifelong latency period after initial infection. Rarely, however, when the EBV immediate early gene BZLF1 is expressed by a specific stimulus, the virus switches to the lytic cycle to produce progeny viruses. We found that EBV infection reduced levels of various ceramide species in gastric cancer cells. As ceramide is a bioactive lipid implicated in the infection of various viruses, we assessed the effect of ceramide on the EBV lytic cycle. Treatment with C6-ceramide (C6-Cer) induced an increase in the endogenous ceramide pool and increased production of the viral product as well as BZLF1 expression. Treatment with the ceramidase inhibitor ceranib-2 induced EBV lytic replication with an increase in the endogenous ceramide pool. The glucosylceramide synthase inhibitor Genz-123346 inhibited C6-Cer-induced lytic replication. C6-Cer induced ERK1/2 and CREB phosphorylation, c-JUN expression, and accumulation of the autophagosome marker LC3B. Treatment with MEK1/2 inhibitor U0126 or autophagy initiation inhibitor 3-MA suppressed C6-Cer-induced EBV lytic replication. In contrast, the autophagosome-lysosome fusion inhibitor chloroquine induced BZLF1 expression. Transfection with siCREB reduced ERK1/2 phosphorylation and C6-Cer-induced BZLF1 expression. On the other hand, siJUN transfection did not affect BZLF1 expression. Our results show that increased endogenous ceramide and glycosyl ceramide (GlyCer) following C6-Cer treatment induce EBV lytic replication in gastric cancer cells via ERK1/2 and CREB phosphorylation and autophagosome accumulation.
Project description:Epstein-Barr virus (EBV) reactivation in latently infected B cells is essential for persistent infection and B cell receptor (BCR) activation is a physiologically relevant stimulus for EBV reactivation. Post-translational modifications, such as phosphorylation and ubiquitination, are known to be regulated by antigen binding to BCR within minutes. However, a detailed understanding of the signaling alterations at later time when EBV is being actively replicated remains elusive. To gain insights into BCR activation-mediated reprogramming of the cellular environment in both Akata-BX1 (EBV+) and Akata-4E3 (EBV-) B cells, we utilized a 3-plex stable isotope labeling by amino acid in cell culture (SILAC)-based quantitative proteomic approach to monitor the dynamic changes of protein ubiquitination during the course of immunoglobulin G (IgG) cross-linking of BCRs. We observed temporal alterations in the level of ubiquitination on approximately 150 sites in both Akata-BX1 (EBV+) and Akata-4E3 (EBV-) B cells post-IgG cross-linking compared with no cross-linking controls, with the majority of protein ubiquitination down-regulated. Our analysis revealed that IgG cross-linking plays a major role in the regulation of protein ubiquitination in both EBV+ and EBV- B cells. Bioinformatic analyses of up-regulated ubiquitination events revealed significant enrichment of proteins involved in RNA processing. Among the down-regulated ubiquitination events are proteins enriched in apoptosis and the ubiquitin-proteasome pathway. The comparative and quantitative studies provide a foundation for further understanding how BCR activation regulates cellular protein ubiquitination and how EBV utilizes or subverts BCR engagement-mediated changes to facilitate viral replication.
Project description:Both Human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) are associated with an increased risk of malignancies. People living with HIV frequently have EBV reactivation and develop EBV-associated B-cell malignancies. In this study, we aimed to uncover the involvement of HIV-1 and EBV co-existence in the development of B-cell malignancies. We studied two viral transcriptional activators (HIV-1 Tat and EBV Zta) and their possible interaction since they both have cell-penetration domains and can be found simultaneously in the blood or cells of people with HIV. We found that Tat and Zta directly bound each other in human B cells, T cells, and blood serum. Using RNA-sequencing, we found that combined Tat and Zta action in B cells differed from a simple combination of two proteins. A subset of genes, activated by Tat or Zta alone, that trigger an immune response and antigen presentation in B cells, remained unchanged when two proteins were combined. B cells, treated or transfected with Tat and Zta, exhibited a substantial decrease in HLA-ABC (MHC class I) expression, a critical component of the antigen processing and presentation pathway. HLA-ABC downregulation induced by Tat and Zta interaction conferred protection against cytotoxic T cell recognition of EBV-infected B cells. Tat and Zta interaction was also observed in serum from an HIV-positive individual. To conclude, we demonstrated for the first time the direct interaction between HIV-1 Tat and EBV Zta; this interaction can bring about immune evasion of EBV-infected or transformed B cells.