Dissertations / Theses: 'Epstein-Barr Virus Burkitt's Lymphoma'

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MUNDO, LUCIA. "Infectious agents and cancer: A look into EBV pathways involved in the transition from infection to lymphomagenesis." Doctoral thesis, Università di Siena, 2017. http://hdl.handle.net/11365/1012697.

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Epidemiological and biological studies have conclusively proved that infectious agents are among the main causes of cancer worldwide. Approximately 18% of all human cancer have been linked to persistent infections from RNA or DNA viruses that include Epstein-Barr virus (EBV), human papilloma virus and Human T-lymphotropic virus type 1. Although each virus has its own specific mechanism for promoting carcinogenesis, the most common outcome for virus-induced reprogramming is genomic instability, including accumulation of mutations, aberrations and DNA damage. The progression to cancer as result of infection is usually a rare event and when it occurs it requires years to decades from the initial infection to tumour development. EBV, classified as class I carcinogen by WHO for its ability of transforming B-cell and functioning as oncogenic factor, is one of the many factors that can be linked to human malignancies. It is estimated that it accounts for more than 200,000 cases of cancer each year and that 1.8% of all cancer deaths are due to EBV. Here, we described several molecular mechanisms underlying the virus-induced carcinogenesis, expecially in Burkitt’s and Plasmablastic lymphoma. We performed RNA-Seq on 20 eBL cases from Uganda and we showed that the mutational and viral landscape of eBL is more complex than previously reported. First, we found the presence of other herpesviridae family members in 8 cases (40%), in particular human herpesvirus 5 and human herpesvirus 8 and confirmed their presence by immunohistochemistry in the adjacent non-neoplastic tissue. Second, we identified a distinct latency program in EBV involving lytic genes in association with TCF3 activity. Third, by comparing the eBL mutational landscape with published data on sporadic Burkitt lymphoma (sBL), we detected lower frequencies of mutations in MYC, ID3, TCF3 and TP53, and a higher frequency of mutation in ARID1A in eBL samples. Recurrent mutations in two genes not previously associated with eBL were identified in 20% of tumors: RHOA and cyclin F (CCNF). We also observed that polyviral samples showed lower numbers of somatic mutations in common altered genes in comparison to sBL specimens, suggesting dual mechanisms of transformation, mutation versus virus driven in sBL and eBL respectively. We also identified a subset of cellular and viral microRNAs differentially expressed between Epstein-Barr-positive and Epstein-Barr-negative Burkitt lymphoma cases. Of these, we characterized the effects of viral BART6-3p on regulation of cellular genes. In particular, we analyzed the IL-6 receptor genes (IL-6Rα and IL-6ST), PTEN and WT1 expression for their possible relevance to Burkitt lymphoma. By means of immunohistochemistry, we observed a down-regulation of the IL-6 receptor and PTEN specifically in Epstein-Barr-positive Burkitt lymphoma cases, which may result in the impairment of key cellular pathways and may contribute to malignant transformation. On the contrary, no differences were observed between Epstein-Barr-positive and Epstein-Barr-negative Burkitt lymphoma cases for WT1 expression. The oncogenic role of EBV was also investigated in Plasmablastic lymphoma. Our analysis revealed a non-canonical latency program with the partial expression of some proteins characterizing latency II and the activation of an abortive lytic cycle. We also performed microRNAs expression profiling through next generation sequencing to investigate the cellular and viral pattern of Plasmastic lymphoma. We identify a subset of viral miRNAs differentially expressed and showed an important role of EBV-miRNAs-Bart-19 in affecting many cellular pathways including lipid metabolism and cell proliferation. Finally, we considered the fact EBV might have contributed to lymphomagenesis in more samples than those remaining EBV positive by exploting a “hit and run” mechanism. We investigated a total of 10 cases and we found that all the samples (n=6) diagnosed as EBV negative by immunohistochemistry and EBER-ISH demonstrated the presence of EBV-microRNAs and EBV genome. This points at the possibility that EBV might have contributed to lymphomagenesis in all our patients, and propose microRNAs detection as the most specific and sensitive tool to recognize EBV vestiges. Collectively, our preliminary results point at an active role for the Epstein-Barr virus in lymphomagenesis and suggest new possible mechanisms used by the virus in determining dysregulation of the host cell physiology. Moreover, our data would have considerable implications for EBV-related diseases control and development of novel EBV-detection strategies.

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2

Donati, Daria. "Malaria, B lymphocytes and Epstein-Barr virus : emerging concepts on Burkitt's lymphoma pathogenesis /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-403-1/.

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3

Kaymaz, Yasin. "Genomic and Transcriptomic Investigation of Endemic Burkitt Lymphoma and Epstein Barr Virus." eScholarship@UMMS, 2017. https://escholarship.umassmed.edu/gsbs_diss/914.

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Endemic Burkitt lymphoma (eBL) is the most common pediatric cancer in malaria-endemic equatorial Africa and nearly always contains Epstein-Barr virus (EBV), unlike sporadic Burkitt Lymphoma (sBL) that occurs with a lower incidence in developed countries. Despite this increased burden the study of eBL has lagged. Additionally, while EBV was isolated from an African Burkitt lymphoma tumor 50 years ago, however, the impact of viral variation in oncogenesis is just beginning to be fully explored. In my thesis research, I focused on investigating molecular genetics of the endemic form of this lymphoma with a particular emphasis on the role of the virus and its variation in pathogenesis using novel sequencing and bioinformatic strategies. First, we sought to understand pathogenesis by investigating transcriptomes using RNA sequencing (RNAseq) from 30 primary eBL tumors and compared to sBL tumors. BL tumor samples were prospectively obtained from 2009 until 2012 in Kenya. Within eBL tumors, minimal expression differences were found based on anatomical presentation site, in-hospital survival rates, and EBV genome type; suggesting that eBL tumors are homogeneous without marked subtypes. The outstanding difference detected using surrogate variable analysis was the significantly decreased expression of key genes in the immunoproteasome complex in eBL tumors carrying type 2 EBV compared to type 1 EBV. Secondly, in comparison to previously published pediatric sBL specimens, the majority of the expression and pathway differences were related to the PTEN/PI3K/mTOR signaling pathway and was correlated most strongly with EBV status rather than the geographic designation. Moreover, the common mutations were observed significantly less frequently in eBL tumors harboring EBV type 1, with mutation frequencies similar between tumors with EBV type 2 and without EBV. In addition to the previously reported genes, we identified a set of new genes mutated in BL. Overall, these suggested that EBV, particularly EBV type 1, supports BL oncogenesis alleviating the need for particular driver mutations in the human genome. Second, we sought to comprehensively define sequence variations of EBV across the viral genome in eBL tumor cells and normal infections, and correlate variations with clinical phenotypes and disease risk. We investigated the whole genome sequence of EBV from primary tumors (N=41) and plasma from eBL patients (N=21) as well as EBV in the blood of healthy children (N=29) within the same malaria endemic region. We conducted a genome wide association analysis study with viral genomes of healthy kids and BL kids. Furthermore, we found that the frequencies of EBV types among healthy kids were at equal levels while they were skewed in favor of type 1 (70%) among eBL kids. To pinpoint the fundamental divergence between viral genome subtypes, type 1 and type 2, we constructed phylogenetic trees comparing to all public EBV genomes. The pattern of variation defined the substructures correlated with the subtypes. This investigation not only deciphers the puzzling pathogenic differences between subtypes but also helps to understand how these two EBV types persist in the population at the same time. Overall, this research provides insight into the molecular underpinning of eBL and the role of EBV. It further provides the groundwork and means to unravel the complexity of EBV population structure and provide insight into the viral variation that may influence oncogenesis and outcomes in eBL and other EBV-associated diseases. In addition, genomic and mutational analyses of Burkitt lymphoma tumors identify key differences based on viral content and clinical outcomes suggesting new avenues for the development of prognostic molecular biomarkers and therapeutic interventions.

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Kaymaz, Yasin. "Genomic and Transcriptomic Investigation of Endemic Burkitt Lymphoma and Epstein Barr Virus." eScholarship@UMMS, 2007. http://escholarship.umassmed.edu/gsbs_diss/914.

Full text

Abstract:

Endemic Burkitt lymphoma (eBL) is the most common pediatric cancer in malaria-endemic equatorial Africa and nearly always contains Epstein-Barr virus (EBV), unlike sporadic Burkitt Lymphoma (sBL) that occurs with a lower incidence in developed countries. Despite this increased burden the study of eBL has lagged. Additionally, while EBV was isolated from an African Burkitt lymphoma tumor 50 years ago, however, the impact of viral variation in oncogenesis is just beginning to be fully explored. In my thesis research, I focused on investigating molecular genetics of the endemic form of this lymphoma with a particular emphasis on the role of the virus and its variation in pathogenesis using novel sequencing and bioinformatic strategies. First, we sought to understand pathogenesis by investigating transcriptomes using RNA sequencing (RNAseq) from 30 primary eBL tumors and compared to sBL tumors. BL tumor samples were prospectively obtained from 2009 until 2012 in Kenya. Within eBL tumors, minimal expression differences were found based on anatomical presentation site, in-hospital survival rates, and EBV genome type; suggesting that eBL tumors are homogeneous without marked subtypes. The outstanding difference detected using surrogate variable analysis was the significantly decreased expression of key genes in the immunoproteasome complex in eBL tumors carrying type 2 EBV compared to type 1 EBV. Secondly, in comparison to previously published pediatric sBL specimens, the majority of the expression and pathway differences were related to the PTEN/PI3K/mTOR signaling pathway and was correlated most strongly with EBV status rather than the geographic designation. Moreover, the common mutations were observed significantly less frequently in eBL tumors harboring EBV type 1, with mutation frequencies similar between tumors with EBV type 2 and without EBV. In addition to the previously reported genes, we identified a set of new genes mutated in BL. Overall, these suggested that EBV, particularly EBV type 1, supports BL oncogenesis alleviating the need for particular driver mutations in the human genome. Second, we sought to comprehensively define sequence variations of EBV across the viral genome in eBL tumor cells and normal infections, and correlate variations with clinical phenotypes and disease risk. We investigated the whole genome sequence of EBV from primary tumors (N=41) and plasma from eBL patients (N=21) as well as EBV in the blood of healthy children (N=29) within the same malaria endemic region. We conducted a genome wide association analysis study with viral genomes of healthy kids and BL kids. Furthermore, we found that the frequencies of EBV types among healthy kids were at equal levels while they were skewed in favor of type 1 (70%) among eBL kids. To pinpoint the fundamental divergence between viral genome subtypes, type 1 and type 2, we constructed phylogenetic trees comparing to all public EBV genomes. The pattern of variation defined the substructures correlated with the subtypes. This investigation not only deciphers the puzzling pathogenic differences between subtypes but also helps to understand how these two EBV types persist in the population at the same time. Overall, this research provides insight into the molecular underpinning of eBL and the role of EBV. It further provides the groundwork and means to unravel the complexity of EBV population structure and provide insight into the viral variation that may influence oncogenesis and outcomes in eBL and other EBV-associated diseases. In addition, genomic and mutational analyses of Burkitt lymphoma tumors identify key differences based on viral content and clinical outcomes suggesting new avenues for the development of prognostic molecular biomarkers and therapeutic interventions.

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Amoroso, Richard Benjamin Couture. "Studies on the expression and function of Epstein-Barr virus encoded microRNAs in Burkitt lymphoma." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/3694/.

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Epstein-Barr virus (EBV) encodes at least 40 microRNAs (miRNAs), an important class of negative regulators that control gene expression through posttranscriptional mechanisms. However the contribution of these EBV-encoded miRNAs to the pathogenesis of virus-associated lymphomas remains poorly understood. Using newly-developed PCR assays, we first quantified the levels of viral BHRF1 and BART miRNAs in a range of EBV-positive cell lines. We show for the first time that all three BHRF1 miRNAs are abundantly expressed in Wp-restricted Burkitt lymphoma (BL) cells, but not Latency I BL cells lacking detectable Cp- or Wp-initiated EBNA transcripts. In contrast to some earlier reports, we also detected robust expression of BART miRNAs in B cell lines, although there was wide variation between individual miRNAs in a given cell. Analysis of BHRF1 and BART transcription, both in latent and lytic infection, suggested that maturation may be a key step in regulating steady-state miRNA levels. We also successfully generated lentiviral systems to express the BHRF1 miRNAs and developed reporter constructs to measure BHRF1 miRNA-dependent repression \(in\) \(vivo\). While attempts to identify BHRF1 miRNA-induced changes on the BL transcriptome were inconclusive, our data suggest that the BHRF1 miRNAs are insufficient to affect BL cell growth and cell survival.

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Boyce, Andrew John. "Epstein-Barr virus genome loss from endemic Burkitt lymphoma and its effect on cell phenotype." Thesis, University of Birmingham, 2009. http://etheses.bham.ac.uk//id/eprint/4731/.

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Epstein-Barr virus (EBV), a B cell growth-transforming human herpesvirus, is linked to several human malignancies, in particular endemic Burkitt lymphoma (eBL). Though always present in this tumour, EBV‟s role remains unclear since, in most cases, viral gene expression is restricted to the viral genome maintenance protein, EBNA1 and the non-coding EBERs, BARTs and BART-derived microRNAs (Latency I infection). This study first asked whether EBV was required for continued BL growth in vitro by screening a panel of Latency I BL cell lines for EBV-loss clones. Such clones were isolated from 5/12 BL lines tested. In each case these cells proved to be more sensitive to apoptosis than their EBV-positive counterparts, an effect which could be reversed by reinfection with a recombinant EBV. Cellular gene expression profiling of EBV-positive and EBV-loss clones on four BL backgrounds revealed transcriptional differences but none that were common to all four tumours. To examine the responsible viral function, a doxycycline-regulated vector was used to express EBNA1 and EBERs at physiologic and supra-physiologic levels in EBV-loss cells on two BL backgrounds. Contrary to previous reports, neither EBNA1 nor EBERs conferred apoptosis resistance, a result which implicates the BARTs or BART-derived microRNAs as novel anti-apoptotic effectors.

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Leung, Yuen-ying, and 梁婉瑩. "Effects of histone deacetylase and proteasome inhibitors on Epstein-barr virus-positive Burkitt lymphoma and lymphoblastoid cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/207474.

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Burkitt lymphoma (BL) was the first tumor found to be strongly associated with Epstein-Barr virus (EBV). Almost 100% of the lymphoma cells are cycling, necessitating dose- and time-intense multi-agent chemotherapy regimens to achieve a cure of the disease. Whilst standard risk BL can be cured with this approach, high risk BL with leukaemic and CNS disease has significantly inferior survival. The intensive chemotherapy regimen causes considerable toxicity to the patients and relapse of BL is largely incurable. Thus, novel therapeutic approaches for high risk and relapsed BL are needed. Histone deacetylase inhibitors (HDACis) represent a novel class of drugs with potent anti-cancer effect in a wide range of malignancies. In the first part of this study, we tested HDACis of different classes for their ability to inhibit cell proliferation and activate the lytic cycle of EBV in a panel of EBV-positive BL cells of different latent viral gene expression patterns (type I, Wp-restricted and type III latency with highly restrictive, partial and full spectrum of EBV latent gene expression, respectively). Different HDACis could inhibit proliferation of EBV-positive BL cells in a time- and dose-dependent manner but only weakly activate the viral lytic cycle indicating that the drugs’ cytotoxic effect is independent of the EBV lytic cycle. Of note, BL cells of Wp-restricted or type III latency were more resistant to killing by HDACis than those of latency I, suggesting a possible link between relative resistance to the drug and expression of the latent viral genes. Bortezomib, a proteasome inhibitor, may have synergistic action with HDACis on lymphoid malignancies. We hypothesized that Bortezomib could potentiate the killing of EBV-positive BL cells by HDACis. In the second part, we tested the effect of combination of a FDA-approved HDACi, suberoylanilide hydroxamic acid (SAHA) and Bortezomib in the same panel of BL cells and also EBV-transformed lymphoblastoid cell lines (LCLs) which represent an in-vitro model of EBV-associated post-transplant lymphoproliferative disorder (PTLD). Interestingly, combination of SAHA and Bortezomib significantly enhanced the killing of BL cells of Wp-restricted or type III latency. Furthermore, the resistance to either SAHA or Bortezomib alone in contrast to synergistic killing by the combination of the two drugs could be observed in LCLs which also have the type III latency pattern. Compared with either drug alone, combination of SAHA and Bortezomib induced enhanced apoptosis in Wp-restricetd BL cells and LCLs as shown by the increase in the percentage of annexin V-positive cell, sub-G1 population and the proteolytic cleavage of apoptotic markers including PARP, caspase-3 and -9. The drug combination hyper-acetylated histone and induced cell cycle arrest. Combination of SAHA and Bortezomib was further shown to suppress the growth of BL xenograft in nude mice. In conclusion, our data indicated that expression of partial or full spectrum of viral latent genes in EBV-positive BL cells of Wp-restricted or type III latency confers resistance of the tumor cells to cytotoxic effect of HDACis. Bortezomib could potentiate SAHA-induced apoptosis of both BL cells and LCLs and might overcome mechanism of drug resistance.
published_or_final_version
Paediatrics and Adolescent Medicine
Master
Master of Philosophy

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Rao, Sieta Padmaja. "Zebularine reactivates silenced E-cadherin but unlike 5-Azacytidine does not induce switching from latent to lytic Epstein-Barr virus infection in Burkitt's lymphoma Akata cells /." [S.l.] : [s.n.], 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000253262.

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Imreh, Marta P. "Modulation of cellular and viral functions in Epstein-Barr virus infected cells /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-171-3.

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Cherdoud-Chelouah, Sonia. "Rôle fonctionnel de la protéine de latence EBNA-LP exprimée dans les cellules de lymphome de Burkitt infectées par la souche P3HR1 du virus d’Epstein-Barr." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA11T023.

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Notre équipe à montré que les cellules de lymphome de Burkitt (LB) infectées par le variant P3HR1 du virus d’Epstein Barr (EBV) sont plus résistantes à l’apoptose que les cellules de LB EBV(-) ou infectées par la souche sauvage. Le variant P3HR1 porte une délétion de son génome à l’origine de l’expression d’une forme tronquée d’EBNA-LP (EBNA-LPt). Nous avons étudié le rôle fonctionnel d’EBNA-LPt dans les cellules de LB infectées par le variant P3HR1. Nous avons, dans un premier temps, identifié par une étude protéomique ses partenaires cellulaires et viraux. Nous avons ainsi confirmé l’interaction entre EBNA-LPt et la PP2A, déjà établie par notre équipe, et montré qu’elle forme également des complexes avec d’autres protéines impliquées dans de nombreux processus cellulaires, notamment dans l’apoptose et dans la régulation transcriptionnelle. Nous avons ensuite, par une étude du transcriptome, montré le rôle de régulateur transcriptionnel des deux formes d’EBNA-LP exprimées de façon stable dans les cellules de LB EBV(-). En effet, nous avons montré que les deux formes d’EBNA-LP sont capables de réguler l’expression des gènes cellulaires indépendamment du contexte viral. Certains de ces gènes sont communs aux deux formes d’EBNA-LP, d’autres sont spécifiques de chaque forme. Nous avons constaté que le domaine Y1Y2 est indispensable à la surexpression, par EBNA-LP, du gène cellulaire codant pour la protéine ID1 qui est impliquée dans la stabilisation de la LMP1 et dans l’immortalisation cellulaire. Nous avons également remarqué que certains gènes sont régulés de la même façon en présence d’EBNA-LP seule ou dans un contexte viral complet. Enfin et pour mieux comprendre les mécanismes de résistance à l’apoptose dans les cellules de LB infectées par la souche P3HR1, nous avons élargi notre étude du transcriptome à des cellules traitées ou non par un inducteur de l’apoptose, la cycloheximide. Nos résultats préliminaires montrent que les voies de signalisation des récepteurs au TNF (TNFR1 et 2) sont rapidement et fortement induites dans les cellules sensibles alors qu’elles sont faiblement et tardivement induites dans les cellules résistantes. Cette étude montre également que la voie de signalisation JNK est probablement activée de façon très précoce dans les cellules sensibles contrairement aux cellules résistantes
Our group has previously shown that Burkitt’s lymphoma (BL) cells infected by the P3HR1 variant of Epstein-Barr virus (EBV) are more resistant to apoptotsis than EBV (-) BL cells or cells infected by wild-type EBV. The genome of the P3HR1 variant carries a deletion responsible for the expression of a truncated form of EBNA-LP (tEBNA-LP). We studied the functional role of tEBNA-LP in BL cells infected by the P3HR1 variant. A proteomic study allow us to identify cellular and viral partners of tEBNA-LP. These results confirmed the interaction between tEBNA-LP and PP2A, already established by our group, and showed that tEBNA-LP can form complexes with other proteins involved in many cellular processes including apoptosis and regulation of transcription. We have then demonstrated by a transcriptomic study, the transcriptional regulatory role of both forms of EBNA-LP stably expressed in EBV(-) BL cell lines. Indeed, we showed that both forms of EBNA-LP can regulate the expression of cellular genes independently of viral context. Some of these genes are common to both forms of EBNA-LP, others are specific to each form. We found that Y1Y2 domaine of EBNA-LP is essential to overexpression of the cellular gene encoding ID1 protein which is involved in LMP1 stabilization and cellular mmortalization. We also noted that some genes are similarly regulated in the presence of EBNA-LP alone or in the presence of viral genome. Finally, to better undertand the mecanisms of resistance to apoptosis in BL cell lines infected by the P3HR1 variant we extended our transcriptomic analysis to cell lines treated or not with an apoptosis inducer, cycloheximide. Our preliminary results show that TNF receptors signaling pathways (TNFR1 and 2) are rapidly and strongly induced in sensitive cell lines while being weakly and belatedly induced in the resistant cell lines. This study also shows that the JNK signaling pathway is probably activated very early in the sensitive cells in contrast to resistant cell lines

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Movassagh, Mercedeh J. "Comprehensive Computational Assessment And Evaluation of Epstein Barr virus (EBV) Variations, miRNAs, And EBERs in eBL, AML And Across Cancers." eScholarship@UMMS, 2019. https://escholarship.umassmed.edu/gsbs_diss/1022.

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Viruses are known to be associated with 20% of human cancers. Epstein Barr virus (EBV) in particular is the first virus associated with human cancers. Here, we computationally detect EBV and explore the effects of this virus across cancers by taking advantage of the fact that EBV microRNAs (miRNAs) and Epstein Barr virus small RNAs (EBERs) are expressed at all viral latencies. We identify and characterize two sub-populations of EBV positive tumors: those with high levels of EBV miRNA and EBERS expression and those with medium levels of expression. Based on principal component analysis (PCA) and hierarchical clustering of viral miRNAs across all samples we observe a pattern of expression for these EBV miRNAs which is correlated with both the tumor cell type (B cell versus epithelial cell) and with the overall levels of expression of these miRNAs. We further investigated the effect of the levels of EBV miRNAs with the overall survival of patients across cancers. Through Kaplan Meier survival analysis we observe a significant correlation with levels of EBV miRNAs and lower survival in adult AML patients. We also designed a machine learning model for risk assessment of EBV in association with adult AML and other clinical factors. Our next aim was to identify targets of EBV miRNAs, hence, we used a combination of previously known methodologies for miRNA target detection in addition to a multivariable regression approach to identify targets of these viral miRNAs in stomach cancer. Finally, we investigate the variations across EBV subtype specific EBNA3C gene which interacts with the host immune system. Preliminary data suggests potential regional variations plus higher pathogenicity of subtype 1 in comparison to subtype 2 EBV. Overall, these studies further our understanding of how EBV manipulates the tumor microenvironment across cancer subtypes.

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Kiss, Csaba. "Analysis of viral and cellular gene expression patterns in cells latently infected with EBV by suppression subtractive hybridization /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-707-x.

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Sompallae, Ramakrishna Rao. "In silico analysis of pathways targeted by EBV infection and malignant transformation." Stockholm : Karolinska institutet, 2009. http://diss.kib.ki.se/2009/978-91-7409-693-4/.

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Coy, Joanna Lucy. "Epstein Barr nuclear antigen 1 induced lymphoma in transgenic mice." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241746.

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CALENDER, ALAIN. "Pathogenese des lymphomes malins non hodgkiniens : donnees generales et contribution experimentale centree sur la biologie cellulaire et moleculaire du lymphome de burkitt et des lymphomes folliculaires." Lyon 1, 1991. http://www.theses.fr/1991LYO1M040.

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Peh, Suat-Cheng. "The pattern of Epstein-Barr virus infections in lymphoma of Malaysians." Thesis, University of Leicester, 2002. http://hdl.handle.net/2381/29407.

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Previous studies of the pattern of lymphoma in multi-ethnic West Malaysian population have shown a high frequency of EBV association in childhood Hodgkin's lymphoma (HL) and adult NK/T-cell lymphomas, with a predilection of the former in Indians and the latter in Chinese. This thesis aims to expand knowledge of the EBV association pattern in childhood non-Hodgkin's lymphoma (NHL), Burkitt's lymphoma (BL), ethnic predilection and virus subtype pattern for Malaysian patients. The childhood NHL pattern is similar to other parts of the world. BL, lymphoblastic lymphoma and diffuse large cell lymphoma (predominantly CD30- positive, ALK-positive anaplastic large cell type) form the 3 major groups of the disease. The difference in subtype composition results in different overall EBV association rates for T- and B-cell lymphomas when compared to the adults, being 3x higher in the B-cell lymphomas in children and the reverse for T-cell lymphomas. The frequency of BL in West Malaysian children is not higher and in the malaria endemic state of Sabah the pattern of lymphoma is similar to other Asian series. The low incidence of jaw presentation, more common abdominal and lymph node disease, and EBV association rate of 33% are features of sporadic BL. Using a sensitive nested-PCR test on 38 lymphomas, 14 nasopharyngeal carcinomas, 12 reactive lymph nodes and tonsils, only EBV type A was identified. This was irrespective of the anatomical sites of the biopsy material, age group, sex and ethnicity of the patients. EBV was identified in sequential biopsies of EBV associated lymphomas, and continued to be absent in non-EBV associated cases, supporting the probable pathogenetic role of the virus. In conclusion, EBV type A is the prevalent subtype of virus present in Malaysian patients. East-West differences in lymphoma pattern are less distinct in children. BL is of the sporadic type and the predilection of EBV associated T- NHL to Chinese is again reflected in Malaysian children, supporting the notion that ethnic Chinese are at risk of developing EBV-associated cancers.

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Patton, John Thomas Jr. "Identifying and Targeting Immune Escape Mechanisms in Epstein-Barr Virus-Driven Lymphoproliferative Disease." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461074032.

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Ito, Yoshinori, Jun-ichi Kawada, and Hiroshi Kimura. "EPSTEIN-BARR VIRUS-ASSOCIATED LYMPHOID MALIGNANCIES : THE EXPANDING SPECTRUM OF HEMATOPOIETIC NEOPLASMS." Nagoya University School of Medicine, 2013. http://hdl.handle.net/2237/18466.

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Shen, Lijun, and 沈立軍. "Immune escape mechanisms in EBV-associated nasal NK/T-Cell lymphoma." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31244713.

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20

Hinke, Juliane Elisabeth [Verfasser], and Judith [Akademischer Betreuer] Dierlamm. "Die Integration des Epstein-Barr-Virus : Zytogenetische Lokalisation viraler Integrationsloki in EBV-positiven Zelllinien des Burkitt-Lymphoms / Juliane Elisabeth Hinke. Betreuer: Judith Dierlamm." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2013. http://d-nb.info/1031280324/34.

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Baarle, Debbie van. "Viro-immunological studies on the role of Epstein-Barr virus in the development of AIDS-related non-Hodgkin's lymphoma." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2000. http://dare.uva.nl/document/57552.

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Tao, Qian. "Cellular localization and gene expression of epstein-barr virus in non-neoplastic nasal mucosa and nasal lymphoma /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17538828.

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23

Kinch, Amelie. "Posttransplant Lymphoproliferative Disorders : Studies of Epstein-Barr Virus, Regulatory T Cells and Tumor Origin." Doctoral thesis, Uppsala universitet, Infektionssjukdomar, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-234130.

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Epstein-Barr virus (EBV) infects almost all humans and establishes lifelong latency in B cells. Posttransplant lymphoproliferative disorder (PTLD) is a rare but serious complication after transplantation triggered by immunosuppression and often related to EBV infection. The aim of this thesis was to study the role of EBV in relation to clinical and histological features of PTLD, regulatory T cells (Tregs), and donor or recipient origin of PTLD. EBV surveillance after allogeneic hematopoietic stem cell transplantation (allo-HSCT) showed that EBV reactivations were common, but that symptomatic EBV disease (including PTLD) only occurred in the high-risk group (unrelated or mismatched related grafts, reduced-intensity conditioning). A threshold of 1000 copies/ml plasma distinguished EBV disease from asymptomatic reactivations. In a population-based cohort of 135 PTLDs/lymphomas after solid organ transplantation (SOT) almost half were EBV–. EBV+ PTLDs were associated with B cell phenotype, non-germinal center subtype of diffuse large B cell lymphoma (DLBCL), early-onset, graft involvement, antithymocyte globulin treatment, and younger age. EBV– PTLDs were associated with T cell phenotype, bone marrow involvement, and hepatitis C. Most PTLDs displayed few or no intratumoral Tregs with the marker FoxP3, possibly due to heavy immunosuppression. Half of both FoxP3+ and FoxP3– PTLDs were EBV+. FoxP3+ PTLDs were associated with B cell phenotype and hepatitis C. All PTLDs for which tumor origin could be determined were recipient-derived and half of them were EBV+. Eight of twelve recipient-derived graft PTLDs were disseminated outside the graft. T cell PTLD and hepatitis C were independently associated with inferior overall survival, whereas subtype of DLBCL, FoxP3-expression, and EBV-status did not influence survival. In conclusion, monitoring of EBV DNAemia in high-risk patients after allo-HSCT and pre-emptive therapy is valuable for prevention of PTLD. Use of antithymocyte globulin increases the risk for EBV+ PTLDs after allo-HSCT and SOT. With long follow-up time, a large proportion of PLTDs after SOT are EBV– with a different clinical presentation. Tregs are rare in PTLD and do not affect survival. The vast majority of PTLDs after SOT is of recipient origin. Graft PTLDs are more likely recipient-derived if disseminated. EBV-status is not associated with intratumoral Tregs or PTLD of recipient origin.

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Davies, Gillian Lucy. "Investigation into the contribution of the Epstein Barr virus nuclear antigen 1 to the pathogenesis of Hodgkin's lymphoma." Thesis, Birmingham City University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479110.

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Duc, Touyana. "Caractérisation moléculaire et sérologique de l'infection à Epstein-Barr virus chez les patients porteurs du VIH souffrant d'un lymphome." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAV074.

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En 2016, les lymphoproliférations malignes [lymphome malin non hodgkinien (LNH) et lymphome de Hodgkin (LH)] restent un problème majeur chez les patients porteurs du VIH (PPVIH) car chaque année de 1 à 6 % de ces patients développent des lymphomes. Ces pathologies apparaissent actuellement comme une des principales causes de mortalité chez les PPVIH.Le virus d’Epstein-Barr (EBV), connu de longue date pour son pouvoir immortalisant des lymphocytes B et les propriétés oncogènes de certaines de ses protéines, apparait comme un cofacteur favorisant plus ou moins important de ces lymphomes chez les PPVIH. Quand le virus est présent dans la cellule tumorale ; on parle de cancer associé à l’EBV.Une des questions toujours en suspens est de savoir si la quantification de l’ADN viral EBV (charge virale) et le profil sérologique EBV dans le sang des PPVIH peuvent aider à mieux comprendre la physiopathologie de ces lymphomes et à mieux prendre en charge les PPVIH qui en souffrent.Ce travail de thèse effectuée en co-tutelle entre l’université de Grenoble-Alpes et l’université médicale d’Irkoutsk vise à contribuer à répondre à cette question.La partie bibliographique de cette thèse synthétise (i) les connaissances actuelles sur l’épidémiologie et la physiopathologie des LH (synthèse non publiée en français) et sur le rôle de l’EBV dans les LNH chez les PPVIH (article publié en russe dans « Siberian Medical Journal » en 2015); (ii) les études publiées sur la mesure de la charge virale et la sérologie EBV chez les PPVIH.La partie expérimentale de cette thèse est constituée de trois articles. Le premier article publié dans Journal of Clinical Microbiology en 2016 rapporte la démonstration que l’utilisation d’un standard international développé par l’OMS peut améliorer la précision de la mesure de la charge virale EBV dans le sang. Le deuxième article en cours d’écriture concerne les résultats préliminaires d’une étude de cohorte mise en place par l’ANRS qui suit des PVVIH atteints de LH. Dans cette étude, l’objectif principal était de savoir si la charge virale et la sérologie EBV lors de la découverte du LH pouvaient constituer des marqueurs pronostiques de cette maladie comme cela été décrit dans des LH survenant chez des patients non infectés par le VIH. Nos résultats préliminaires ne vont pas dans ce sens et ces marqueurs ne semblent donc pas utiles pour une amélioration de la prise en charge des LH chez les PPVIH. Le troisième article publié en russe en 2015 dans « HIV infection and Iimmunosuppressive Disorders » décrit l’épidémiologie des lymphomes chez PPVIH de l’Université Médicale d’Irkoutsk. Il montre une importante augmentation des LNH chez les PPVIH entre 2000 et 2014 liée à une épidémie VIH non contrôlée dans cette région de Russie
In 2016, malignant lymphoproliférations [non Hodgkin's (NHL) and Hodgkin's lymphomas (HL)] remain a major concern in patients living with HIV (PLHIV), that each year 1-6% of these patients develop lymphomas. Lymphomas are the major cause of mortality in this population.Epstein-Bar Virus (EBV), long known for his immortalizing B cells power and oncogenic properties of some of its proteins, emerges as a cofactor favoring lymphoproliferations, more or less important, depending on the type of lymphoproliferation.One of the outstanding questions is whether the molecular and/or serological characterizations of EBV infection may help to better understand the pathophysiology of these diseases and better manage patients suffering from HIV-associated lymphomas.This dissertation under joint supervision between the University Grenoble Alpes and Irkutsk State Medical University aims to answer this question.The literature review of this thesis summarizes: (i) the role of EBV in LNH development in PLHIV (article published in Russian journal “Siberian Medical Journal” in 2015) and the current knowledge on the epidemiology and pathophysiology of Hodgkin's lymphoma (non published in French); (ii) published studies on the EBV viral load and serological evolutions in PLHIV.The experiments consist of three articles. The first article published in Journal of Clinical Microbiology in 2016, reports the demonstration that the application of international standard EBV developed by WHO can improve the quantification of EBV viral load in whole blood. The second study (in writing for publication) contains preliminary results of French National Agency for Research of HIV and hepatitis cohort study investigating PLHIV suffering from Hodgkin's lymphoma. The study focuses on whether the EBV viral load and serology of newly diagnosed lymphoma could provide prognostic information for this disease, as has been described in HIV-negative patients with HL. Our preliminary results don’t support this hypothesis; than EBV markers don’t can be used for best management of HL in PLHIV. The third study published in Russian Journal “HIV infection and Immunosuppressive disorders” (2015) describes the epidemiology of HIV-associated lymphoma in Irkutsk Oblast. The article shows that non-Hodgkin lymphoma incidence rates in PLHIV during 2007-2014 are probably due to HIV epidemic non-controlled in this Russian region

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Huang, Yen-Lin. "Analyse des altérations oncogéniques associées aux lymphomes NK/T de type nasal." Thesis, Paris Est, 2009. http://www.theses.fr/2009PEST0052.

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Dans les pays occidentaux, les lymphomes T périphériques et NK représentent environ 10% des lymphomes non-Hodgkiniens. Le lymphome NK/T de type nasal est l'une des entités de présentation extra-ganglionnaire les plus fréquentes, en Asie, et en Amérique Centrale et du Sud. Il survient classiquement dans la sphère nasopharyngée avec une prédilection pour les adultes jeunes. Morphologiquement, la tumeur est souvent angiocentrique avec une invasion de la paroi des vaisseaux par les cellules tumorales d'aspect variable. Ces lymphomes ont le plus souvent une origine NK avec un phénotype CD3+ (cytoplasmique), CD5-, CD56+, CD4-/CD8-, expression des molécules cytotoxiques et absence de réarrangement des gènes des récepteurs T. Le virus d'Epstein-Barr est présent dans la quasi-totalité des cellules tumorales dans sa forme clonage épisomale, avec une latence de type II, suggérant son rôle dans l'oncogenèse. A côté des mutations fréquentes des gènes FAS et TP53 (p53) et des méthylations de TP73 et CDKN2A (p16), des délétions du bras long du chromosome 6q sont fréquemment observées. Très récemment, des méthylations et des mutations des gènes suppresseurs de tumeur PRDM1, ATG5, et AIM1 localisés en 6q21 ont été retrouvées dans les lignées de lymphome NK/T de type nasal. Nous avons réalisé une analyse combinée du profil d'expression génique et du profil génomique par hybridation comparative sur puces, d'échantillons tumoraux de lymphome NK/T de type nasal (n=9) et de lignées, comparés à celle de lymphocytes NK normaux et de lymphomes T périphériques, sans autre spécificité (PTCL, NOS). Nous avons identifié la signature moléculaire particulière du lymphome NK/T de type nasal caractérisée par un haut niveau des trascrits de marqueurs de cellules NK et de molécules cytotoxiques, notamment de granzyme H dans les lymphomes NK/T de type nasal comparé aux PTCL, NOS. Par immunohistochimie, nous avons validé l'expression "spécifique" de granzyme H par les cellules tumorales du lymphome NK/T de type nasal, qui pourrait constituer un nouveau marqueur de ces lymphomes. Comparé aux cellules NK normales, le lymphome NK/T de type nasal a une signature plus proche des cellules NK activées que des NK au repos et sur-expriment des gènes associés à la biologie vasculaire, des gènes induits par l'EBV, et PDGFRA. Nous avons confirmé l'expression protéique de PDGFRAa et de sa forme phosphorylée, et montré in vitro la sensibilité de la lignée tumorale MEC04 à l'imatinib mesytale. La dérégulation des voies de signalisation AKT, JAK-STAT et NF-kB, suggérée par les analyses bioinformatiques, a été corroborée par la mise en évidence d'une expression nucléaire des formes phosphorylées d'AKT, de STAT3 et de RelA dans les lymphomes NK/T de type nasal. De plus, plusieurs gènes dérégulés dans ces voies moléculaires sont localisés dans des régions altérées de manière récurrente par des gains ou des pertes (AKT3 (1q44), IL6R (1q21.3), CCL2 (17q12), TNFRSF21 (6p12.3)). En plus de l'activation constitutive de STAT3 confirmée par l'expression nucléaire de phospho-STAT3, l'inhibition de croissance et l'augmentation de la mort cellulaire des cellules de la lignée MEC04 résultant de l'inhibition de STAT3 conforte le rôle de STAT3 dan la lymphomagenèse du lymphome NK/T nasal. L'analyse intégrée a également mis en évidence la dérégulation du gène suppresseur de tumeur HACE1 en 6q21, confirmée par RT-PCR quantitative. Bien que les mécanismes exacts conduisant à l'activation de plusieurs voies moléculaires, de même qu'à la dérégultaion de HACE1 ne soient pas déterminés, nos résultats identifient plusieurs voies oncogéniques impliquées dans le lymphome NK/T de type nasal ainsi que de nouveaux biomarqueurs diagnostiques - comme granzyme H - et des cicles thérapeutiques d'intérêt. L'étude en cours du profil d'expression des microARNs pourrait apporter un éclairage sur les mécanismes impliqués dans certaines voies identifiées
In Western countries, mature natural killer (NK)- and T-cell lymphomas account for 15% to 20% of aggressive lymphomas and around 10 % of all non-Hodgkin lymphomas. This number is higher in Asia, with 25% in Japan and 39% in Taiwan. Among those T- and NK-cell lymphomas with primary extranodal presentation, extranodal NK/T-cell lymphoma of nasal type (nasal NKTCL) is one of the most common entities in Asian, Central and South American populations. It classically arises in the nasal region showing a predilection for young adults with male predominance. This tumor morphologically exhibits an angiocentric and angio destructive growth pattern, admixed with polymorphous non-neoplastic infiltrates. Most tumor cells have a cytoplasmic CD3+, CD5-, CD56+, CD4-/CD8- phenotype with expression of cytotoxic granule-associated proteins and without rearrangement of T-cell receptors genes. Killer immunoglobulin-like receptors have been reproted to be expressed in a subset of this lymphoma and its expression might be associated with prognosis. Epstein-Barr virus is present in virtually all neoplastic cells in its clonal episomal form with type II latency program, implying a role in oncogenesis. Although the results were variable between different studies, methylations of TP73 (p73) and CDKN2A (p16) and mutations of FAS and TP53 (p53) were frequently found in nasal NKTCL. Genomic alterations have also been reported in nasal NKTCL with frequent deletion in chromosome 6q. A very recent study also identified both methylations and mutations of three putative tumor suppressor genes PRDM, ATG5, and AIM1 mapping to del6q21 in nasal NKTCL cell times. We performed integrative gene expression profiling and array-based comparative genomic hybridization analyses of nasal NKTCL tumors as well as tumour-derived cell lines, compared to that of normal NK cells and peripheral T-cell lymphomas, not otherwise specified (PTCL, NOS). We identified the distinctive molecular signature of nasal NKTCL with high transcript levels for NK-cell markers ans cytotoxic molecules, especially granzyme H in nasal NKTCL compared to PTCL, NOS. By immunohistochemistry, we validated expression of grnzyme H which appears a novel sensitive biomarker of nasal NKTCL. Compared to normal NK cells, nasal NKTCL tumors were closer to activated than resting cells and overexpressed several genes related to vascular biology, EBV-induced genes and PDGFRA. Notably, we confirmed the expression of PDGFRa and its phosphorylated form at the protein level, and in vitro the MEC04, nasal NKTCL-cell line, was sensitive to imatinib mesylate. Deregulation of the AKT, JAK-STAT and NF-kB pathways suggested by bioinformatical analysis, was corroborated by nuclear expression of phosphorylated AKT, STAT3 and RelA in nasal NKTCL, and several deregulated genes in these pathways mapped to regions of recurrent copy number aberrations (AKT3 (1q44), IL6R (1q21.3), CCL2 (17q12), TNFRSF21 (6p12.3)). In addition to constitutive activation of STAT3 as confirmed by the demonstration of phosphorylated STAT3 in the nuclei of neoplastic nasal NKTCL cells, growth inhibition and cell death of nasal NKTCL cells induced by STAT3 inhibition implied the role of STAT3 in the nasal NK/T-cell lymphomagenesis. Integrative analysis and qRT-PCR analysis also evidenced deregulation of another tumor suppressor HACE1 in the frequently deleed 6q21 region. Although the exact mechanism of activation of several pathways as well as that of HACE1 deregulation remains to be determined, our studies highlight emerging oncogenic pathways in nasal NKTCL and identify novel diagnostic and therapeutic targets. The ongoing investigation of microRNA expression profiling might shed light in a better understanding of the pathogenesis of nasal NKTCL and especially of the activation of oncogenic pathways. Connectivity map analysis may also help to depict other targeted therapies useful to improve the prognosis of this agressive lymphoma

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Pujals, Anaïs. "Etude des mécanismes de résistance à l’apoptose induits par le virus d’Epstein-Barr et mise en place de nouvelles stratégies thérapeutiques pour le traitement des lymphomes B." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA11T054/document.

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Résumé en français : Notre équipe étudie les mécanismes de l’apoptose induite par la nutline-3, une molécule capable de se fixer sur MDM2 et d’activer la p53, dans différents types de lymphomes associés au virus d’Epstein-Barr (EBV) comme le lymphome de Burkitt (LB) ou syndromes lymphoprolifératifs post-transplantation (PTLD). Nos résultats montrent que la nutline-3 induit l’apoptose des cellules de LB EBV (-) alors que les cellules EBV (+) en latence de type III sont résistantes. Mon travail de thèse a consisté à étudier les mécanismes impliqués dans ce phénomène de résistance afin de mettre en place des stratégies pour les contourner. Une première étude initiée par les résultats d’une analyse transcriptomique, effectuée après traitement avec la nutline-3 de deux lignées qui ne diffèrent que par leur statut EBV, nous a permis de montrer que : 1) l’autophagie est induite en réponse au traitement dans les cellules EBV (+) en latence de type III ; 2) ces cellules expriment fortement Bécline-1 et présentent une activation constitutive de l’autophagie ; 3) l’autophagie contribue à la résistance de ces cellules à l’apoptose. Par ailleurs, nos résultats indiquent que la protéine anti-apoptotique Bcl-2 est également impliquée dans la résistance de ces cellules et que l’utilisation d’ABT-737, un inhibiteur de Bcl-2, restaure leur sensibilité à la nutline-3. L’efficacité de ce composé a donc été évaluée in vivo, seul ou en combinaison avec des traitements conventionnels (Cyclophosphamide pour le LB et Rituximab pour les PTLD). Les résultats obtenus lors de ces études pré-cliniques montrent que : 1) ABT-737 réduit considérablement la croissance tumorale et augmente la survie de souris xénogreffées avec des cellules d’une lignée lymphoblastoïde (LCL, utilisées comme modèle pour les PTLD) alors qu’il n’a pas d’effets chez les souris xénogreffées avec une lignée de LB ; 2) la combinaison BT-737/Cyclophosphamide permet de limiter la croissance tumorale durant le traitement mais n’améliore pas la survie des souris xénogreffées avec une lignée de LB ; 3) l’association ABT-737/Rituximab est très efficace et induit une rémission complète chez 70% des souris xénogreffées avec la lignée de LCL
- Résumé en anglais : Our team is working on the mechanisms of apoptosis induced by nutlin-3, a small molecule which binds to MDM2 and activates p53, in different lymphomas associated with Epstein-Barr virus such as Burkitt lymphoma (BL) or Post-transplant lymphoproliferative disorder (PTLD). Our results show that nutlin-3 strongly induce apoptosis in EBV (-) cells whereas EBV (+) latency III cells are much more resistant. The aim of my PhD project was to study the mechanisms involved in the resistance of EBV (+) latency III cells to apoptosis and to develop new therapeutic strategies to bypass these mechanisms. A transcriptomic analysis was realized after treatment with nutlin-3 of two cell lines which only differs by their EBV status. Based on the results obtained, a study was performed which allow us to show that: 1) autophagy is induced after nutlin-3 treatment in EBV (+) latency III cells; 2) these cells strongly expressed beclin-1 and present a constitutively high level of autophagy; 3) autophagy is involved in the resistance of apoptosis observed in these cells. Furthermore, our results demonstrate that Bcl-2 also contributes to the resistance of EBV (+) latency III cells and that treatment with ABT-737, a Bcl-2 inhibitor, restores their susceptibility to nutlin-3 treatment. We thus assessed the efficiency of this compound in vivo, in monotherapy or associated with conventional treatments (Cyclophosphamide for BL and Rituximab for PTLD). Results obtained during these pre-clinical studies show that: 1) ABT-737 reduces tumor growth and increase the overall survival of mice xenografted with a lymphoblastoïd cell line (LCL, used as a model for PTLD studies) but has no effects on mice xenografed with BL cell lines; 2) the association ABT-737/Cyclophosphamide reduces tumor growth during treatment but doesn’t improve the overall survival of mice xenografed with BL cell lines; 3) the association ABT-737/Rituximab is very efficient and induces 70% of complete remission in mice xenografted with LCL

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Delecluse, Henri-Jacques. "L'intégration dans le génome cellulaire comme mode de persistance lors de la latence virale : l'exemple des herpèsvirus d'Epstein-Barr et de Marek." Lyon 1, 1995. http://www.theses.fr/1995LYO1T130.

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Winter, Sarah. "Identification and characterization of new genetic defects involved in Epstein-Barr virus immune response and T-cell proliferation Loss of RASGRP1 in humans impairs T-cell expansion leading to Epstein-Barr virus susceptibility RASGRP1 is a negative factor of EOMES expression in T cells in association with an exhausted phenotype IL-27RA deficiency in humans, a new cause of susceptibility to Epstein-Barr virus infection Association of bi-allelic loss-of-function mutations in PIK3CD and TNFRSF9 causes fatal chronic active Epstein-Barr virus infection with T-cell lymphoproliferation." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCB180.

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L'infection par le virus d'Epstein-Barr (EBV) touche plus de 90% de la population mondiale et est dans la majorité des cas asymptomatique dans l'enfance. Certains individus, souvent à l'adolescence, développent une primo-infection symptomatique appelée mononucléose infectieuse. L'EBV peut également entraîner chez des individus immunodéprimés des désordres lymphoprolifératifs, des lymphomes ou syndromes d'activation lymphohistiocytaire. Depuis une trentaine d'années plusieurs déficits immunitaires primitifs entraînant une susceptibilité particulière à l'infection par l'EBV ont été identifiés ; parmi ceux-ci figurent les déficits en SAP, XIAP, ITK, MAGT1, CTPS1, CD27 ou CD70. Leur caractérisation a permis de mettre en évidence de nouveaux mécanismes immunitaires impliqués dans la réponse anti-EBV. L'objectif de ce travail a donc été d'identifier de nouveaux défauts génétiques entraînant une susceptibilité particulière à l'infection par l'EBV. Au sein de deux familles consanguines, trois patients ont développé des lymphomes B liés à l'EBV ainsi que des épisodes de lymphoproliférations également liées à ce virus. Deux mutations homozygotes dans RASGRP1 entraînant un stop prématuré, A638GfsStoXp16 et S314X ont été respectivement identifiées par séquençage d'exome (WES) chez ces deux familles. Sur le plan immunologique ces patients sont caractérisés par une lymphopénie CD4+, un défaut de cellules T naïves, une accumulation de cellules T effectrices mémoires et une absence de cellules MAIT et iNKT. RASGRP1 est une protéine de la famille des facteurs d'échange nucléotidiques fortement exprimée dans les lymphocytes T et NK. Elle active la petite protéine G Ras qui elle-même va activer la cascade des kinases Raf-MEK-ERK (ou cascade des MAP kinases). L'analyse des cellules du patient ou de cellules de contrôles sains dans lesquelles l'expression de RASGRP1 a été inhibée par RNA interférents a permis de mettre en évidence le rôle fondamental de RASGRP1 dans la prolifération lymphocytaire T et l'expression de gènes impliqués dans cette prolifération tels que CTPS1, PCNA ou RECQL4. A l'inverse, RASGRP1 semble être un régulateur négatif du facteur de transcription EOMES impliqué dans la différenciation des lymphocytes T. EOMES est retrouvé surexprimé dans les lymphocytes T en l'absence de RASGRP1, pouvant expliquer le phénotype effecteur mémoire et sénescent des lymphocytes des patients déficients en RASGRP1. Au sein d'une autre famille consanguine, chez deux patients ayant développé une primo-infection à l'EBV symptomatique, dont l'un a nécessité un traitement par anti-CD20 et corticoïdes, a été identifiée une mutation homozygote non-sens dans IL27RA entraînant un codon stop précoce (G96X) et une absence d'expression protéique dans les cellules T des patients. IL-27RA code pour la sous-unité alpha du récepteur à l'IL-27 impliqué dans la prolifération des lymphocytes T et le développement Th1 des lymphocytes CD4+ via la cascade des JAKs/STATs. Dans les lymphocytes T des patients, l'activation de la voie JAK/STAT par l'IL-27 est complètement abolie et l'IL-27 n'augmente pas leur prolifération en réponse à une stimulation anti-CD3 (au contraire des cellules contrôles issues de donneurs sains). De plus, un défaut fonctionnel de la voie Th1 est retrouvé chez un des deux patients. Ces résultats démontrent que la voie dépendante de l'IL-27RA est déficiente chez ces deux patients et que ce défaut génétique rend vraisemblablement compte de leur immunodéficience. La description de ces deux nouveaux déficits immunitaires caractérisés par une susceptibilité à l'EBV a permis de confirmer le rôle fondamental dans l'étape de prolifération et d'expansion des lymphocytes T au cours de la réponse immune anti-EBV, mais également de mettre en évidence de nouveaux mécanismes et facteurs impliqués dans cette étape
Epstein-Barr virus (EBV) is a gamma-herpes virus that infects 90% of humans without any symptoms in most cases. Some individuals, mostly adolescents, can develop infectious mononucleosis. In immunocompromised individuals, EBV can lead to lymphoproliferative disorders, lymphomas or virus-associated hemophagocytic syndrome. In the past 30 years, several primary immunodeficiencies associated with a high risk to develop EBV-associated disorders have been identified, including SAP, XIAP, ITK, MAGT1, CTPS1, CD27 or CD70 deficiencies. Their characterization has highlighted specific pathways required for efficient immunity to EBV. The objective of this work was to identify new genetic defects associated to a peculiar susceptibility to EBV infection. In two consanguineous families 3 patients developed EBV-associated B cell lymphomas and other EBV-associated lymphoproliferative disorders. By while exome sequencing (WES) we identified two homozygous mutations in RASGRP1 leading to a premature stop codon (A638GfsX16 and S314X). Immunologically these patients presented with CD4+ lymphopenia, low number of naïve T cells and absence of MAIT and iNKT cells. RASGRP1 codes for a diacylglycerol-regulated exchange factor preferentially expressed in T and NK cells, which acts as an activator of the small G protein RAS and the downstream RAF-MEK-ERK kinases cascade (or MAP kinases pathway). Analysis of patients' T cells or control T cells in which RASGRP1 expression was downregulated by short-hairpin RNA technique has highlighted the crucial role of RASGRP1 in T cell proliferation and in the expression of genes known to be involved in cell proliferation or replication such as CTPS1, PCNA or RECQL4. Furthermore, RASGRP1 seems to be a negative regulator of the transcription factor EOMES involved in T cell differentiation. EOMES was found overexpressed in T cells in the absence of RASGRP1. This might explain the skewed effector-memory and exhausted phenotype observed in RASGRP1-deficient patients. In another large consanguineous family two patients developed symptomatic EBV primary infection requiring for one or them anti-CD20 and corticosteroids treatment. Homozygous nonsense mutation leading to a premature stop codon in IL-27RA (G96X) was identified by exome sequencing. No protein expression could be detected in patients' cells. IL-27RA codes for the subunit of IL-27 receptor involved T cell proliferation and Th1 CD4+ development through JAKs/STATs pathway. Stimulation of patients' T cells with IL-27 led to absent JAK/STAT activation pathway and did not enhance their proliferation after anti-CD3 stimulation (contrary to healthy control T cells). Furthermore, Th1 functional defect was found in one patient. These results demonstrate that IL-27RA pathway is deficient is these two patients and that this genetic defect causes their immunodeficiency. Characterization of these two new primary immunodeficiencies associated with a high susceptibility to EBV infection has confirmed the crucial role of T cell proliferation and activation in EBV immune response but has also highlighted new pathways involved in T cell expansion

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Pujals, Anaïs. "Etude des mécanismes de résistance à l'apoptose induits par le virus d'Epstein-Barr et mise en place de nouvelles stratégies thérapeutiques pour le traitement des lymphomes B." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00767146.

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Notre équipe étudie les mécanismes de l'apoptose induite par la nutline-3, une molécule capable de se fixer sur MDM2 et d'activer la p53, dans différents types de lymphomes associés au virus d'Epstein-Barr (EBV) comme le lymphome de Burkitt (LB) ou syndromes lymphoprolifératifs post-transplantation (PTLD). Nos résultats montrent que la nutline-3 induit l'apoptose des cellules de LB EBV (-) alors que les cellules EBV (+) en latence de type III sont résistantes. Mon travail de thèse a consisté à étudier les mécanismes impliqués dans ce phénomène de résistance afin de mettre en place des stratégies pour les contourner. Une première étude initiée par les résultats d'une analyse transcriptomique, effectuée après traitement avec la nutline-3 de deux lignées qui ne diffèrent que par leur statut EBV, nous a permis de montrer que : 1) l'autophagie est induite en réponse au traitement dans les cellules EBV (+) en latence de type III ; 2) ces cellules expriment fortement Bécline-1 et présentent une activation constitutive de l'autophagie ; 3) l'autophagie contribue à la résistance de ces cellules à l'apoptose. Par ailleurs, nos résultats indiquent que la protéine anti-apoptotique Bcl-2 est également impliquée dans la résistance de ces cellules et que l'utilisation d'ABT-737, un inhibiteur de Bcl-2, restaure leur sensibilité à la nutline-3. L'efficacité de ce composé a donc été évaluée in vivo, seul ou en combinaison avec des traitements conventionnels (Cyclophosphamide pour le LB et Rituximab pour les PTLD). Les résultats obtenus lors de ces études pré-cliniques montrent que : 1) ABT-737 réduit considérablement la croissance tumorale et augmente la survie de souris xénogreffées avec des cellules d'une lignée lymphoblastoïde (LCL, utilisées comme modèle pour les PTLD) alors qu'il n'a pas d'effets chez les souris xénogreffées avec une lignée de LB ; 2) la combinaison BT-737/Cyclophosphamide permet de limiter la croissance tumorale durant le traitement mais n'améliore pas la survie des souris xénogreffées avec une lignée de LB ; 3) l'association ABT-737/Rituximab est très efficace et induit une rémission complète chez 70% des souris xénogreffées avec la lignée de LCL

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Klibi, Manel. "Remaniement nucléaire dans les lymphocytes B provoqué par les virus EBV et VIH-1." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA11T090/document.

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Le lymphome de Burkitt (BL) est due dans 80% des cas à une translocation chromosomique t(8;14)(q24;q32). Cette translocation marque l’évènement initial de la transformation maligne d’une cellule B normale, par délocalisation de l’oncogène CMYC à proximité du locus du gène codant pour la chaîne lourde d’immunoglobuline IGH par le mécanisme de réparation de l’ADN NHEJ durant l’hypermutation somatique (SMH). La probabilité de cette translocation est inversement proportionnelle à la distance qui sépare les loci portés par les deux chromosomes. La translocation (8;14) (q24;q32) qui apparaît durant les étapes de différentiation des lymphocytes B est encore plus importante chez les patients infectés par le virus Epstein-Barr (EBV) et le virus de l’immunodéficience humaine (VIH-1). L’objectif de notre étude est de déterminer les origines possibles de la translocation t(8;14) (q24;q32)dans les lymphocytes B normaux humains. Nous nous sommes intéressés tout d’abord à la dynamique de la localisation nucléaire des loci IGH et CMYC dans les lymphocytes B activés. Nous avons particulièrement étudié l’impact des virus EBV et VIH-1 sur l’organisation des gènes IGH et CMYC.Nous avons utilisé la technique d’hybridation in situ à fluorescence FISH pour la détection de CMYC (8q24) et IGH (14q32). Dans les lymphocytes B naïfs, CMYC est localisé du côté de la périphérie nucléaire, en revanche IGH est central, les deux loci sont complétement distants dans le noyau.L’activation des lymphocytes B induisait une augmentation de la colocalisation IGH-CMYC. La proximité physique entre les deux loci augmente la probabilité de leur translocation durant la SHM et favorise la t(8;14) (q24;q32) dans les lymphocytes B. Nous avons montré que les virus EBV et VIH-1ont un effet important sur la délocalisation IGH-CMYC dans les lymphocytes B. Nous avons aussi déterminé une molécule virale VIH-1 qui intervenait aussi dans la dérégulation de la localisation nucléaire des gènes IGH et CMYC. Nous avons déterminé deux mécanismes différents et indépendants impliqués dans la dynamique des loci IGH et CMYC : le premier mécanisme intervient dans le processus de développement normal des lymphocytes B, et le deuxième mécanisme dépend des virus ainsi que des molécules virales (particulièrement la Tat-HIV-1)
Eighty percent of Burkitt's lymphomas (BL) cases bear translocation t(8;14)(q24;q32). Thistranslocation is the initial event in malignant transformation of normal B-cell and derives from nonhomologousend joining of the oncogene CMYC to the immunoglobulin heavy chain locus IGH duringSomatic Hypermutation (SHM) of IGH. The probability of this translocation is inversely proportionalto the distance between the loci of involved chromosomes. The translocation t(8;14)(q24;q32) occursduring normal development of B-lymphocytes and more probable in patients infected with Epstein-Barr virus (EBV) and the human immunodeficiency virus (HIV-1).The subject of this study was to determine the possible origin of the translocation t(8;14)(q24;q32) inhuman normal B-lymphocytes. We followed the dynamics of the nuclear localization of IGH andCMYC genes in activated B-lymphocytes. We payed particular attention to the impact of EBV andHIV-1 viruses on dynamics of both IGH and CMYC. We applied Fluorescence in situ hybridization(FISH) for detection of CMYC (8q24) and IGH (14q32). In naïve B-cells CMYC is mainly localized inthe periphery of nucleus, whereas IGH is preferentially localized in the nuclear centre, i.e. these lociare distanced by a radius of cell nucleus. Activated B-lymphocytes displayed dramatic increase ofnumber of cells with colocalized IGH and CMYC. Close physical proximity of CMYC to IGH duringSHM amplifies the probability of occurance of translocation t(8;14)(q24;q32) in human Blymphocytes.Interestingly, we observed even more pronounced impact of EBVand HIV-1onproximity of IGH and CMYC. Finaly, among the molecules of HIV-1 we revealed those which possessthe most regulative role on dynamics of both IGH and CMYC. Our results suggest about twoindependent mechanisms of IGH and CMYC dynamics: the first is appropriate for normal developmentof B-lymphocytes and the second depends on virus and viral molecules, such as transactivator of viraltranscription HIV Tat

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Schreck, Sabine. "Tumour cell induced leukocyte migration in Hodgkin Lymphoma (HL) : prognostic impact of T-cell subsets, B-cells and Epstein-Barr virus (EBV)-infection in HL." kostenfrei, 2008. http://d-nb.info/989353001/34.

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Kriel, Raymond Frank. "An investigation of Epstein-Barr Virus (EBV) latency type and MYC gene aberrations in plasmablastic lymphoma diagnosed at Groote Schuur Hospital, Cape Town, South Africa." Master's thesis, Faculty of Health Sciences, 2020. http://hdl.handle.net/11427/32714.

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Introduction: Plasmablastic lymphoma (PBL) is a rare, aggressive, AIDS-associated non-Hodgkin lymphoma. The pathogenesis of PBL is incompletely understood, however association with the Epstein-Barr virus (EBV) and the MYC gene, have been identified as important pathogenic mechanisms. Aims and objectives: To characterise the EBV latency in a cohort of patients diagnosed with PBL at Groote Schuur Hospital (GSH), by means of immunohistochemistry. To determine MYC gene aberrations using fluorescent in situ hybridisation (FISH). Materials and methods: The cohort comprised PBL cases diagnosed from 2005-2017. EBER ISH was used to confirm EBV infection. Manual immunohistochemistry using three monoclonal antibodies for EBV latent proteins, (EBNA1, EBNA2 and LMP1) was used to determine the latency type. Manual MYC FISH was performed on all PBL cases using a dual colour break apart rearrangement probe. Results: Forty-nine cases of PBL were included in this study. Forty-one cases were positive for EBER ISH. Thirty-seven (78.7%) cases showed HIV/EBV coinfection. Latency 0 was observed in 29 (70.7%) cases, latency 1 in 8 (19.5%) and latency 2 in 4 (9.8%) cases. MYC FISH was performed on all 49 PBL cases, of which 30 (61.2%) yielded a result. MYC was intact in 11 (36.7%), translocated in 8 (26.7%) and 11 (36.7 %) cases showed copy number variations. Conclusion: Our research demonstrated 37 (90.2%) of the EBV positive PBL cases showed a restricted latency pattern of 0 or 1. Furthermore we found that MYC gene aberrations consisting of translocations and copy number variations occurred in 19 cases (63.3%) , with copy number variations being higher than cited in current literature. Our study is also the first to investigate PBL EBV latency in SA. An uncommon finding was the existence of MYC gene aberrations in HIV positive, EBV negative PBL cases.

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David, Amandine. "Coopération de voies oncogéniques dans la lymphomagenèse B dépendante de MYC : rôle de NF-kB." Limoges, 2014. https://aurore.unilim.fr/theses/nxfile/default/433795c0-3079-41a8-a828-9bc555d10da9/blobholder:0/2014LIMO310D.pdf.

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Lorsqu’il infecte les lymphocytes B, le virus d’Epstein-Barr (EBV) est en latence III correspondant à l’expression de l’ensemble des gènes viraux dont celui codant LMP1 qui active la voie NF-κB. L’EBV est associé à divers lymphomes dont le lymphome de Burkitt (LB). Le LB est un lymphome agressif caractérisé par la translocation et la surexpression du gène c-myc. Dans le LB, l’EBV exprime son programme de latence I sans expression de LMP1, ni activation de NF-κB. NF-κB peut être toxique dans les cellules de LB. C-Myc est aussi surexprimé dans les Lymphomes B diffus à grandes cellules (DLBCL), parmi lesquelles le sous-type ABC (cellule B activée) présente une activation constitutive de NF-κB. Ces situations différentes dans deux lymphomes distincts soulèvent la question de la compatibilité et/ou de la coopération entre c-Myc et NF-κB. L’objectif du travail est de tester si NF-κB coopère avec c-Myc dans le LB et les ABC-DLBCL. Dans le LB, nos résultats montrent que c- Myc réprime, grâce au facteur CTCF, les protéines de la latence-III de l’EBV pour aboutir à la latence I caractéristique de ce lymphome. Bien qu’au long terme c-Myc inhibe LMP1 et donc NF-κB, nous montrons que la coexistence de la latence-III avec c-Myc augmente la prolifération, la survie et le métabolisme des lymphocytes B. NF-κB joue un rôle majeur dans cet effet coopératif. L’utilisation du modèle murin λc-Myc confirme in vivo l’importance du signal NF-κB dans les étapes précoces du LB au travers de la stimulation du TLR9. Dans les ABC-DLBCL, nous montrons que l’activation continue du récepteur CD40, inducteur de NF-κB, en présence de la dérégulation de c-Myc est responsable in vivo de l’agressivité de ce lymphome. Bien que les histoires oncogéniques du LB et des ABC-DLBCL soient différentes, elles impliquent les mêmes voies oncogéniques (i. E. C-Myc et NF-κB via EBV, TLR9 ou CD40) et leur distinction tient probablement à la temporalité d’action de NF-κB : précoce et transitoire dans le LB et constitutif tout au long du processus transformant dans les ABC-DLBCL.

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SCHUSTER, LAZARUS CATHERINE. "Interaction de steroides glucocorticoides et antiglucocorticoides au cours du mecanisme d'induction des antigenes precoces du virus d'epstein-barr dans des cellules de lymphome de burkitt." Université Louis Pasteur (Strasbourg) (1971-2008), 1991. http://www.theses.fr/1991STR13183.

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L'etude du mecanisme d'action de steroides glucocorticoides (dexamethasone, dxm) et antiglucocorticoides (ru486) a ete entreprise sur deux lignees de cellules de lymphome de burkitt infectees de maniere latente par le virus d'epstein-barr (ebv). La lignee daudi repond aux glucocorticoides par une augmentation de l'expression des antigenes precoces (ea) de l'ebv alors que la lignee raji n'est pas sensible a ces hormones. De plus, ces cellules repondent au facteur de croissance tgf-beta par une augmentation de la synthese des ea. L'action du tgf-beta est egalement inhibee par l'antiglucocorticoide ru486. Dans un premier temps, nous avons entrepris une etude des sites de liaison specifiques des glucocorticoides et des antiglucocorticoides dans ces cellules. L'impact de la dxm et du ru486 a ete compare avec celle du tgf-beta sur la transcription des ea. Les resultats presentes permettent de conclure de la maniere suivante: (i) les glucocorticoides et le tgf-beta stimulent tous deux la transcription de genes precoces de l'ebv au niveau de sequences de regulation cibles des facteurs trans-activateurs viraux, eb1 et r. (ii) les glucocorticoides agissent directement sur le genome viral grace a l'existence d'une sequence de regulation caracteristique (erg); cette derniere est fonctionnelle independamment de la presence d'elements specifiques de la cellule ou du virus. (iii) le ru486 bloque l'action de la dxm au niveau de la transcription alors qu'il inhibe l'action du tgf-beta au niveau post-transcriptionnel. L'effet antiproliferatif de l'antiglucocorticoide ru486 a ete etudie dans la lignee daudi dont la croissance n'est pas modifiee par les glucocorticoides. L'impact du ru486 sur les parametres de croissance et sur la tumorigenicite de ces cellules a ete analysee

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Ayoubian, Mohammad Hiresh [Verfasser], and Eckart [Akademischer Betreuer] Meese. "Differential loading of the Argonaute complex in Epstein-Barr Virus (EBV)-infected cell lines derived from diffuse large B-cell lymphoma (DLBCL) / Mohammad Hiresh Ayoubian ; Betreuer: Eckart Meese." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1173703217/34.

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Mayrink, Graziela Toledo Costa. "Expressão do vírus Epstein-Barr em células tumorais do Linfoma de Hodgkin Clássico: correlação com fatores desfavoráveis e sobrevida." Universidade Federal de Juiz de Fora (UFJF), 2016. https://repositorio.ufjf.br/jspui/handle/ufjf/4795.

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Introdução: A associação entre Linfoma de Hodgkin clássico e o status tumoral do vírus Epstein- Barr é bem definida. Entretanto, a expressão da positividade do vírus Epstein-Barr nas células de Reed-Sternberg/Hodgkin e o impacto dessa relação na sobrevida do Linfoma de Hodgkin clássico permanecem controversos e apresentam resultados conflitantes em estudos de diversas regiões do mundo. Considera-se essencial o entendimento fisiopatogênico desse vírus no prognóstico dos pacientes com Linfoma de Hodgkin clássico. Objetivo: Correlacionar o status do vírus Epstein Barr com os fatores de risco desfavoráveis e fatores prognósticos do Linfoma de Hodgkin clássico em uma população brasileira. Métodos: A positividade do vírus Epstein-Barr foi determinada pelo método de Hibridização in situ para o ácido ribonucleico viral e pela imuno-histoquímica para proteína de membrana latente viral 1. A revisão histopatológica das amostras e a análise dos testes de identificação foram realizadas por uma hematopatologista experiente. Avaliou-se o impacto prognóstico do status do vírus Epstein-Barr em 29 pacientes com Linfoma de Hodgkin clássico. Os fatores prognósticos do Escore Prognóstico Internacional para estadio avançado e os fatores de risco desfavoráveis instituídos pelo Grupo Alemão de Estudos em Hodgkin para estadio limitado foram correlacionados com o status viral nas células tumorais. Para as associações entre presença do vírus Epstein-Barr e outras variáveis categóricas, aplicaram-se os testes de Qui-quadrado ou exato de Fisher. A Sobrevida Global e a Sobrevida Livre de Eventos foram analisadas pelo método de Kaplain-Meier e Modelo de Regressão Proporcional de Cox. Resultados: A média de idade ao diagnóstico foi 33 anos. O status do vírus Epstein-Barr nas células tumorais foi positivo em 37,9%. As células tumorais positivas para o vírus foram mais frequentes em pacientes com idade maior que 45 anos, sem diferença estatística. O subtipo celularidade mista foi o mais frequente (p = 0,02) e o tamanho de efeito desse teste foi de moderada magnitude. Na análise univariada, as sobrevidas Livre de Eventos e Global não apresentaram significância estatística para idade, sexo, estadio clínico, hemoglobina, leucocitose, linfocitopenia, albumina, envolvimento nodal, sintomas B, doença extranodal e doença Bulky entre os pacientes positivos e negativos para o vírus Epstein-Barr (p > 0,05). Os pacientes positivos apresentaram maior Sobrevida Livre de Eventos quando comparados aos pacientes negativos, embora a diferença não apresentasse significância (p = 0,07). Na análise multivariada, a positividade ao vírus Epstein-Barr não demonstrou fator prognóstico significante. Conclusões: Apesar do status do vírus Epstein-Barr nas células tumorais não ter revelado associação com fatores prognósticos adversos e não ter influenciado a Sobrevida Global e a Sobrevida Livre de Eventos, observou-se uma associação positiva entre a presença desse vírus e o subtipo celularidade mista, demonstrando uma relação com o subtipo histológico de pior prognóstico.
Introduction: The association between classical Hodgkin’s Lymphoma and tumor Epstein-Barr virus status is well established. However, the expression of Epstein-Barr virus presence in Hodgkin/Reed-Sternberg cells and its prognosis remains controversial and presentes conflicting results in studies worldwide. Understanding the pathophysiological role of this virus in the prognosis of patients with classical Hodgkin’s Lymphoma is essential. Objective: The aim of this study is to correlate the clinical outcome with Epstein-Barr virus status in a Brazilian population. Methods: Epstein-Barr virus positivity was determined by in situ hybridization for Epstein-Barr virus-encoded ribonucleic acid and immunohistochemistry for viral latent membrane protein-1. The histopathology review and the analysis of identification tests were performed by an hematopathologist expert. The prognostic impact of Epstein-Barr virus status in 29 patients with classical Hodgkin’s Lymphoma was evaluated. Prognostic factors from International Prognostic Score to advanced stage and risk factors from German Hodgkin Study Group to limited stage were correlated with tumor cells Epstein-Barr virus status. In order to determine associations between the presence of Epstein-Barr virus and other categorical variables, Chi-square or Fisher's exact tests were applied. Overall and event-free survivals were analyzed with Kaplan-Meier method and Cox proportional hazards regression models. Results: The mean age at diagnosis was 33 years. Tumor cells Epstein-Barr virus status was positive in 37.9%. Epstein-Barr virus-positive classical Hodgkin’s Lymphoma was more frequent in patients older than 45 years, with no statistical difference. Mixed cellularity histological subtype was more common in Epstein-Barr virus-related tumor cells (p = 0.02) and its effect-size index was medium. Univariate analysis, event-free survival and overall survival were not significantly associated to age, sex, clinical stage, hemoglobin, leukocytes, lymphocytes, albumin, nodal involvement, B symptoms, extranodal disease and Bulky disease in Epstein-Barr virus-positive and negative patients (p > 0.05). Epstein-Barr virus-positive patients had longer event free survival when compared to Epstein-Barr virus-negative ones, even though the difference was not statistically significant (p = 0.07). In multivariate analysis, Epstein Barr virus positivity was not a significant prognostic factor. Conclusions: Although the Epstein-Barr virus status in tumor cells was not associated with adverse prognostic factors and did not influence the overall and event-free survivals, a positive association between the presence of Epstein-Barr virus and Mixed-cellularity subtype was noticed.

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Bahri, Racha. "Séquençage du génome complet du virus d’Epstein-Barr dans des prélèvements issus de lymphomes T angio-immunoblastiques." Thesis, Limoges, 2017. http://www.theses.fr/2017LIMO0106.

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Le virus d’Epstein-Barr (EBV) est un herpèsvirus humain qui infecte plus de 90% de la population mondiale. Il est décrit comme associé à plusieurs pathologies cancéreuses humaines comme les carcinomes nasopharyngés et gastriques et divers lymphomes, comme le lymphome de Burkitt, les lymphomes NK/T et certains lymphomes de Hodgkin. Le lymphome T angio-immunoblastique (LTAI), un cancer des cellules T folliculaires helper TFH, contient souvent des cellules B porteuses de l’EBV. Mais jusqu’à présent le rôle de l’EBV dans la pathogenèse de cette maladie reste inconnu. Dans ce contexte, notre travail avait pour objectif de déterminer si l’EBV associé au LTAI présentait une particularité laissant envisager son rôle dans cette pathologie. Pour ce faire, nous avons étudié la séquence complète de l’EBV au sein d’échantillons de LTAI et comparé les résultats à ceux obtenus pour d’autres lymphomes (B, NK/T) ainsi qu’aux séquences publiées. Le séquençage a tout d’abord été réalisé sur 7 lignées cellulaires positives pour l’EBV, afin de valider la technique, et a ensuite été appliqué aux échantillons d’adénopathies de 40 patients atteints de syndrome lymphoprolifératif, parmi lesquels 20 souffraient de LTAI. L’enrichissement en génome viral a été réalisé par capture à l’aide de sondes spécifiques du génome de l’EBV. Ensuite les librairies ont été synthétisées et séquencées sur les plateformes Illumina MiSeq et NextSeq. Dans un deuxième temps, nous avons réalisé l’assemblage de novo des reads et déterminé la séquence complète du virus majoritaire dans chaque échantillon. Les données obtenues ont été analysées bioinformatiquement. D’une manière intéressante, le virus a été trouvé clonal ou quasi-clonal dans les LTAI alors que les lymphocytes B étaient dans la plupart des cas polyclonaux. En outre, le profil de mutations trouvé présentait des similitudes avec ce qui était trouvé pour les autres lymphomes associés à l’EBV, notamment au niveau des épitopes cibles des cellules de l’immunité suggérant un processus de sélection de la souche virale identique à celui d’une tumeur clonale associée à l’EBV. Ceci pourrait jouer un rôle important dans l’échappement au système immunitaire du virus dans ce contexte multicellulaire complexe. La présence de cellules B polyclonales avec un EBV clonal dans un compartiment T tumoral clonal pourrait relever d’une double sélection tumorale, endogène T et exogène EBV clonal, et pourrait suggérer l’existence de cross-talk entre les cellules B-T
More than 90% of the world's population is infected by Epstein-Barr virus (EBV), a human herpesvirus. EBV is thought to be implicated in the pathogenesis of several human malignancies including epithelial tumors such as nasopharyngeal and gastric carcinomas as well as lymphoproliferative diseases such as Burkitt's lymphoma, NK/T lymphomas and some Hodgkin lymphomas. In angioimmunoblastic T-cell lymphoma (AITL), a peripheral neoplasm of follicular helper T (TFH) cells, a recurrent finding is the presence of EBV-positive B lymphocytes at the beginning of the disease. However, whether this EBV infection of B cells plays a role in AITL pathogenesis remains unclear. In this context, our work aimed to determine if the EBV associated with the AITL presented an oncogenic profile allowing us to consider its role in this pathology. To do this, we sequenced the whole EBV genomes in AIL samples and compared the results to those obtained for other lymphomas (B, NK / T) as well as to previously published sequences. Sequencing was first performed on 7 EBV-positive cell lines to validate the technique, and then was applied to lymphadenopathy specimens from 40 patients with lymphoproliferative disease, of whom 20 had AITL. Enrichment of the viral genome was performed by capture using specific EBV genome probes. The libraries were synthesized and sequenced on Illumina MiSeq and NextSeq platforms. In a second step, we performed de novo assembly and determined the sequence of the virus in each sample. The data obtained were analyzed bioinformatically. Interestingly, the virus was found to be clonal or quasi-clonal in AITL, while B cells were in some cases polyclonal. In addition, the mutational pattern was similar to other EBV-associated lymphomas, especially at the level of the target epitopes of immune cells suggesting a process of selection of the viral strain identical to that of a clone tumor associated with EBV. This could play an important role in the virus escape from the immune system in this context. The presence of polyclonal B cells with clonal EBV in a clonal tumor T cell compartment could be a dual tumor selection; or that is endogenous T and exogenous clonal EBV, and could therefore suggest the existence of a cross-talk between B-T cells

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Hamdi, Leila. "Recherche de facteurs de risque immunologiques associés au lymphome hodgkinien de l’enfant." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA114844/document.

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Le risque de LH est augmenté en cas de déficit immunitaire acquis ou inné. Les déficits immunitaires innés associés à un risque accru de LH, sont les DICV (Déficit Immunitaire Commun Variable), XLP (Syndrome lymphoprolifératif lié au chromosome X) et ALPS (Syndrome lymphoprolifératif Autoimmun). L’objectif de notre travail était d’évaluer la prévalence de ces déficits immunitaires chez des enfants atteints de LH. Nous avons reçu, 395 prélèvements de patients atteints de LH au diagnostic. L’âge médian de la population étudiée est de 13 ans, allant de 3 à 18 ans. Le sex-ratio M/F est de 1.1. Il augmente à 3 au dessous de l’âge de 10 ans. Parmi les biopsies (n=84) qui ont été relues, 87% sont de type scléro-nodulaires (SN), 7% à cellularité mixte (CM) et 6% non spécifié. L’EBV est détecté in situ dans 23% des cas de LH. Les patients atteints de LH-EBV+ sont significativement plus jeunes que ceux atteints de LH-EBV- (p=3.10-4). Ce sont plus fréquemment des garçons que des filles (63% ; M/F : 1,7) et fréquemment de sous-type CM (40%). Enfin, ils ont une charge virale EBV significativement plus élevée (p=3.10-3) que les enfants qui ont un LH-EBV-.Parmi les 83 premiers enfants analysés, un immunophénotypage approfondi a montré une diminution de la population lymphocytaire par rapport aux témoins et une lymphopénie B fréquente (31 patients sur 83 soit 37% des patients). La lymphopénie B était corrélée aux facteurs pronostiques connus du LH. Dans un cas parmi les 31, une baisse des immunoglobulines a été mise en évidence ce qui est évocateur de DICV. Nous avons montré que dans les autres cas, les lymphopénies se corrigeaient à distance de la maladie. La recherche de profil cytokinique associé à ces lymphopénies (TGF, BAFF, IL-7) n’a pas permis de mettre en évidence de mécanisme physiopathologique simple pour expliquer ces lymphopénies. Nous émettons l’hypothèse qu’elles sont liées à l’exposition au contact des cellules tumorales à des signaux favorisant l’apopotose.En ce qui concerne la recherche d’autres déficits immunitaires innés, aucun cas évocateur de XLP n’a été mis en évidence sur la base de la quantification des lymphocytes NKT. Cinq cas parmi les 83 (6%) avaient une expansion de lymphocytes T DN (Lymphocytes TCRαβ CD4-CD8-) dans le sang périphérique. Des dosages de Fas ligand et d’IL-10 plasmatiques ont permis d’exclure un ALPS. Au total, nous n’avons pas pu affirmer de défaut qualitatif des sous-populations lymphocytaires évoquant les déficits immunitaires de type XLP et ALPS. Seule une lymphopénie B avec baisse des IgG est évocatrice de DICV. Nous avons étendu l’analyse à l’ensemble des patients (395patients) avec un contrôle à distance du diagnostic pour ceux qui étaient anormaux. Nous avons identifié 4 patients potentiellement atteints de DICV, 1,5%. Parallèlement, nous avons recherché un déficit de la réponse T anti-EBV par cytomètrie de flux et l’Elispot. L’étude de la réponse T anti-EBV par la cytométrie de flux, a montré une tendance vers une baisse de la production d’IL-2 par les CD4 et les CD8 de patients avec une charge virale EBV élevée en réponse à une stimulation par des peptides EBV en présence de lignées autologues. L’étude de la réponse T anti EBV par la technique d’ELISPOT sur 9 patients n’a pas montré globalement de déficit du contrôle de l’EBV sauf pour une jeune patiente de 10 ans ayant une charge virale EBV très élevée sans réponse T anti-EBV efficace. Les résultats que nous avons obtenus restent à approfondir, ce qui permettra d’enrichir les connaissances actuelles sur cette pathologie
Hodgkin’s Lymphoma (HL) is one of the most frequent lymphomas occurring in childhood. In young children, there is a high predominance in boys and frequent association with Epstein-Barr Virus (EBV). Cohort studies have shown that patients affected by several immune deficiency syndromes - e.g. X-linked lymphoproliferative syndrome (XLP), functional deficit of Fas/FasL pathway and common variable immunodeficiency (CVID) - are risk factors of HL. We intend to search for qualitative and quantitative immune deficiencies as susceptibility factors to child's HL in a prospective study related to Euronet –PHL C1 protocol. Eighty-three patients at diagnosis of HL have been analysed. Median age of the study population is 13 years, (5-18 years). Gender-ratio M/F is 1.1 with a larger male predominance before the age of 10 (gender-ratio of 3). The search for a defect of NKT population that would be suggesting of XLP was negative in all patients. A moderate expansion of circulating TCRαβ+ double negative cells (DNT) has been detected in 5 patients. This expansion has been further explored in the hypothesis of a defect of Fas/FasL pathway by plasmatic quantification of Fas ligand and Il-10. This led to the exclusionof the diagnosis of ALPS. An unexpected high frequency of B-cell lymphopenia has been detected in 31 out of 83 patients (37%). Peripheral B cell lymphopenia was associated with the following poor prognostic factors: advanced stages (p<0.04), low hemoglobin (p<0.06) and B symptoms (p<0.01). B-cell lymphopenia was not statistically correlated with morphology (subtype, amount of tumor cells and necrosis). Remarkably, B-lymphocytic counts were significantly higher in patients with in situ EBV (<0.05).Only a B lymphopenia with low IgG level suggesting DICV was detected. We extended the analysis to all the 395 patients included in the protocol EURONET, so we identified 4 patients with CVID. These cases will be further explored by molecular analyses. In parallel, the specific T-cells response against EBV was studied by flow cytometry in 15 patients and ELISPOT assay in 9 patients with HL. Flow cytometry , suggested a decrease in production of IL-2 by CD4 T cells in patients with high EBV viral load in response to EBV latent and lytic-cycle peptides and autologous lymphoblatoid cells lines compared to controls or patients with LH-EBV-. The ELISPOT-IFNγ assay was used to determine the frequency of T cells that produced IFNγ in response to peptides. One patient demonstrated inappropriate EBV-specific T-cell IFNγ production (<10 IFNγ secreted T cells and >1,000 EBV copies per 250000 PBMCs). These cases will be further explored by molecular analyses.Our findings confirm the known epidemiological data of HL now mainly associated to NS subtype in children and adolescents and EBV status in HL at this age. We show that peripheral B cell lymphopenia in paediatric and adolescent HL patients is frequent and associated with poor prognosis factors. We confirm the association between CVID and HL

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Tanaka, Paula Yurie. "Detecção do vírus de Epstein-Barr (EBV), expressão de FOXP3 e avaliação da carga viral para EBV como marcadores prognósticos nos linfomas relacionados à AIDS." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5167/tde-30102012-133435/.

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Introdução: Pacientes com infecção pelo HIV têm risco aumentado para o desenvolvimento de linfomas não-Hodgkin de células B comparado à população geral. Dentre os mecanismos que podem estar relacionados a esta patologia, encontra-se a reativação do vírus de Epstein-Barr secundária a imunossupressão. O papel do sistema imune para desenvolvimento de tumores é citado há longa data, e seu equilíbrio é mantido pelos linfócitos T regulatórios, cujo principal regulador e marcador é o fator de transcrição FOXP3. Neste estudo, avaliamos a presença de EBER e FOXP3 em amostras diagnósticas, além da carga viral para o vírus de Epstein-Barr em pacientes com linfomas relacionados à Aids a fim de avaliar e correlacionar os resultados como marcadores prognósticos nesta população. Métodos: Análise prospectiva da carga viral para Epstein-Barr no plasma e em células mononucleares do sangue periférico em 15 pacientes com linfomas relacionados à Aids acompanhados no Serviço de Hematologia do Instituto de Infectologia Emílio Ribas e do Hospital das Clínicas/Instituto do Câncer do Estado de São Paulo da Faculdade de Medicina da Universidade de São Paulo. As mensurações foram realizadas para cada paciente por reação da cadeia de polimerase em tempo real ao diagnóstico, término do tratamento e três meses após o término do tratamento. Dois grupos controles constituídos de 26 pacientes infectados pelo HIV em uso de anti-retroviral e sem diagnóstico de linfoma ou infecção oportunista e 30 indivíduos saudáveis também foram analisados para comparação da carga viral para o vírus de Epstein-Barr. Amostras coletadas por biópsia para o diagnóstico de linfoma foram submetidas a análise imuno-histoquímica para FOXP3 e para EBER por hibridização in situ. Resultados: 13 pacientes eram do sexo masculino e dois do sexo feminino, dos quais 14 foram tratados com quimioterapia e um com radioterapia de sistema nervoso central. Nove de 15 pacientes (60%) completaram o tratamento proposto e obtiveram remissão completa. A mediana da carga viral para o vírus de Epstein-Barr antes do tratamento foi 13 cópias/106 nas células mononucleares do sangue periférico (1-1472 cópias/106) e 70 cópias/mL (0-24900 cópias/mL) no plasma. Após o tratamento foi de 0,5/106 (0-109,5) e indetectável no plasma, com diminuição significativa da carga viral em células mononucleares do sangue periférico (p=0,022) e no plasma (p=0,003) ao término do tratamento em comparação ao diagnóstico. Nos pacientes em remissão completa, a carga viral para o vírus de Epstein-Barr diminuiu tanto no plasma como em células mononucleares do sangue periférico na maioria dos casos. A hibridização in situ para EBER resultou positiva em 7/15 (46,7%) casos, sendo significativamente superior no grupo de pacientes com linfomas relacionados a AIDS com mais de um sítio extralinfonodal comprometido (p=0,041) e com linfócitos T CD4 <100 células/L (p=0,026). A expressão de FOXP3 foi negativa em 15/15 (100%) dos pacientes com ARL. Conclusões: A expressão de EBER foi positiva em 7/15 (46,7%) dos pacientes com linfomas relacionados à Aids e superior de forma significativa nos pacientes com estádio mais avançado do linfoma e maior grau de imunossupressão. Observou-se diminuição estatisticamente significativa da mediana de carga viral para o vírus de Epstein-Barr em células mononucleares do sangue periférico (p=0,022) e plasma (p=0,003) após o tratamento do linfoma em comparação aos valores do diagnóstico em pacientes que atingiram remissão completa, o que poderia ser considerado um marcador prognóstico de resposta a terapia
Introduction: Patients with HIV infection have increased risk for development of non-Hodgkins lymphoma compared to general population. Among mechanisms that could be related to this disease is the reactivation of Epstein-Barr virus infection secondary to immunosuppression. The role of immune system in development of tumors was reported a long time ago, and balance of this system is maintained by regulatory T cells; FOXP3 transcription factor is the main regulator and marker of these cells. In this study we evaluated the presence of EBER and FOXP3 in diagnostic samples, and also viral load of Epstein-Barr virus in patients with Aids-related lymphoma to evaluate and correlate the results as prognostic markers in this population. Methods: Prospective analysis of viral load of Epstein-Barr virus in plasma and peripheral blood mononuclear cells from 15 patients with Aids-related lymphoma treated at Instituto de Infectologia Emílio Ribas and Hospital das Clínicas/Instituto do Câncer do Estado de São Paulo da Faculdade de Medicina da Universidade de São Paulo. Viral load measures were performed by real time polymerase chain reaction at diagnosis of lymphoma, completion of treatment and three months afterwards. Two control groups composed by 26 HIV-positive patients in use of HAART and without diagnosis of lymphoma or opportunistic infection and 30 healthy persons were also analyzed for viral load comparison. Biopsy samples performed to lymphoma diagnosis were submitted to immunohistochemistry for FOXP3 and in situ hybridization to EBER. Results: 13 patients were male and two females, 14 were treated with chemotherapy and one with radiotherapy of central nervous system. Nine of 15 patients (60%) completed treatment achieving complete remission. Median viral load of Epstein-Barr virus before treatment was 13 copies/106 in peripheral blood mononuclear cells (1-1472 copies/106) and 70 copies/mL (0-24900 copies/mL) in plasma. After treatment it was 0,5/106 (0-109,5) and not detectable in plasma, with significant decrease of viral load in peripheral blood mononuclear cells (p=0,022) and in plasma (p=0,003) after treatment compared to diagnosis. In patients with complete remission, viral load decreased in the majority of cases. In situ hybridization for EBER was positive in 7/15 (46,7%), and significant higher in the group of patients with Aids-related lymphoma with more than one extra nodal site (p=0,041) and CD4 T-cells <100 cells/L (p=0,026). FOXP3 expression was negative in 15/15 (100%) of patients with ARL. Conclusions: EBER expression was positive in 7/15 (46,7%) of patients with Aids-related lymphoma and significantly higher in patients with advanced stages of lymphoma and higher degree of immunosuppression. Significant decrease in median viral load of Epstein-Barr virus was observed in peripheral blood mononuclear cells (p=0,022) and plasma (p=0,003) after lymphoma treatment compared to diagnosis in patients that achieved complete remission, what could be considered a prognostic marker of response to therapy

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41

Barel, Monique. "Structure et fonctions de gp 140 : le recepteur pour le fragment c3d du troisieme composant du complement et pour le virus d'epstein-barr present a la surface des lymphocytes b humains." Paris 6, 1987. http://www.theses.fr/1987PA066143.

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Bouzid, Makhlouf. "Polymorphisme génétique du virus d'Epstein-Barr en Afrique du Nord : étude dans le carcinome du rhinopharynx, la maladie de Hodgkin et les lymphomes malins non-Hodgkiniens." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10111.

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L'infection quasi mondiale de l'homme par le virus d'epstein-barr (ebv) contraste avec, la restriction geographique de certaines pathologies qui lui sont associees, l'incidence et la distribution en fonction de l'age variant pour une meme maladie a travers le monde. Cette situation complexe suggere l'existence de differentes souches d'ebv, specifiques de regions geographiques ou de certaines pathologies. Le carcinome du rhinopharynx (npc) est une des pathologies associees a l'ebv, qui se caracterise par une incidence intermediaire en afrique du nord en affectant deux tranches d'age de la population : la premiere de 10 a 24 ans et la deuxieme de 45 a 55 ans. La maladie de hodgkin (mdh) est une autre pathologie associee a l'ebv relativement frequente en afrique du nord, ou elle predomine chez l'enfant alors qu'elle affecte les adultes dans les pays industrialises. Nos resultats dans l'analyse genotypique du virus d'epstein-barr implique dans le npc, dans la mdh ou present dans la population saine ebv-positive, ont montre que la souche d'ebv associee au npc d'afrique du nord est de type a/f/wi/xho1kept/h1h2, donc completement differente de celle associee au npc asiatique, de type a/f/wi/xho1lost/h. La meme souche de npc algerien est retrouvee dans les deux pics d'age et associee aux differents stades cliniques de la maladie. Cependant un autre type d'infection est associe a la maladie de hodgkin, qui se caracterise : premierement, par une coinfection avec le type a et le type b d'ebv, et deuxiemement, par le genotype h. Nos resultats ont montre aussi qu'en algerie le genotype h est dominant dans la population generale, dans les lcls etablies avec le virus oropharynge de patients npc ou d'individus sains ebv-positifs, dans la salive de personnes atteintes de npc ou de mdh. L'ensemble de ces resultats soutient l'hypothese d'une specificite pathologique du virus d'epstein-barr en afrique du nord.

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Souza, Eni Maria de [UNIFESP]. "Avaliação da expressão do vírus de Epstein-Barr e metaloproteinase 9 nas células de Hodgkin-Reed-Sternberg e correlação com os parâmetros clínicos e evolutivos em pacientes com Linfoma de Hodgkin clássico no Brasil." Universidade Federal de São Paulo (UNIFESP), 2010. http://repositorio.unifesp.br/handle/11600/9024.

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Made available in DSpace on 2015-07-22T20:49:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-24. Added 1 bitstream(s) on 2015-08-11T03:26:30Z : No. of bitstreams: 1 Publico-429a.pdf: 1596515 bytes, checksum: 2107c026687c3e2ecc62f0a5fffa1409 (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:30Z : No. of bitstreams: 2 Publico-429a.pdf: 1596515 bytes, checksum: 2107c026687c3e2ecc62f0a5fffa1409 (MD5) Publico-429b.pdf: 1614171 bytes, checksum: d98715f7a666adc5ceb185cce978000e (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:30Z : No. of bitstreams: 3 Publico-429a.pdf: 1596515 bytes, checksum: 2107c026687c3e2ecc62f0a5fffa1409 (MD5) Publico-429b.pdf: 1614171 bytes, checksum: d98715f7a666adc5ceb185cce978000e (MD5) Publico-429c.pdf: 1500700 bytes, checksum: 77791620b06c9404d28496c4f4ca3dc3 (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:30Z : No. of bitstreams: 4 Publico-429a.pdf: 1596515 bytes, checksum: 2107c026687c3e2ecc62f0a5fffa1409 (MD5) Publico-429b.pdf: 1614171 bytes, checksum: d98715f7a666adc5ceb185cce978000e (MD5) Publico-429c.pdf: 1500700 bytes, checksum: 77791620b06c9404d28496c4f4ca3dc3 (MD5) Publico-429d.pdf: 1826591 bytes, checksum: 70c3dc706cb97372e3f26a7452c01208 (MD5)
O Linfoma de Hodgkin clássico (LHC) é caracterizado pela presença de uma pequena população de células grandes mono ou multinucleadas, denominadas células de Hodgkin-Reed-Sternberg (HRS), circundadas por uma grande massa inflamatória de células não neoplásicas. O vírus Epstein-Barr (EBV) está associado ao Linfoma de Hodgkin em cerca de 50% dos casos. O diagnóstico do LH EBV relacionado é possível por meio da identificação de proteínas virais nas células HRS. Os métodos considerados ideais para essa identificação são as reações de imuno-histoquímica utilizando anticorpos antiproteína latente de membrana (LMP1) e hibridação in situ com uma sonda para o RNA viral (EBER). A LMP-1 é considerada um oncogene clássico. Foi demonstrado que a LMP-1 pode controlar a expressão do gene da metaloproteinase 9 (MMP-9), em linhagem de células C33A. A MMP-9 é um membro da família das endopeptidases que facilita a invasão tumoral e metástases pela degradação do estroma extracelular. Objetivos: avaliar se a expressão da MMP-9 está relacionada ao status do EBV no tumor e se houve impacto na sobrevida livre de eventos (SLE) e sobrevida global (SG) em pacientes com LHC. Casuística e Métodos: foram examinados 97 pacientes com LHC. Todos os pacientes foram submetidos a protocolos de tratamentos equivalentes (MOPPABV ou ABVD). O diagnóstico histopatológico foi revisto e o subtipo classificado de acordo com a OMS. Reações de imuno-histoquímica para LMP-1 e MMP-9 e hibridação in situ para EBER foram realizadas. Resultados: A presença do EBV foi identificada em 52,5% dos casos. Houve uma maior prevalência do subtipo histológico celularidade mista em pacientes EBV positivos (P = 0,005). Não houve diferença na positividade do EBV em relação à faixa etária, sexo, estádio da doença ou pela presença de sintomas B. A presença do EBV no LHC não influenciou a SLE (P = 0,38) ou a SG (P = 0,80) com uma mediana de acompanhamento de 71 meses. A expressão da MMP-9 ocorreu em 87,6% dos casos estudados. Não houve diferença de casos positivos e negativos em relação ao status do EBV (P = 0,59). Quando avaliada a intensidade da expressão da MMP-9 nos casos positivos também não observamos correlação com a presença do EBV (P = 0,62). Não houve diferença entre o resultado da MMP-9 e os parâmetros: subtipo histológico, estádio, presença de sintomas B, idade e sexo. Não houve influência da MMP-9 na SLE (P = 0,98) e SG (P = 0,60). Conclusões: Demonstramos que a prevalência do LH relacionado ao EBV na população estudada é de 52,5%, e que a presença do vírus não altera a evolução clínica, SLE e SG de pacientes tratados uniformemente. Concluímos ainda que a MMP-9 é fortemente expressa nas células HRS. Não há correlação entre a expressão de MMP-9 e o status do EBV. Nem a SG nem a SLE foram influenciadas pela expressão dessa enzima.
Clinical and histological features of classical Hodgkin lymphoma (cHL) are primarily due to the effects of cytokines, enzymes and chemokines produced by Hodgkin-Reed-Sternberg (HRS) cells and their surrounding inflammatory cells in response to signals triggered by etiological factors such as Epstein-Barr virus (EBV). Matrix metalloproteinase-9 (MMP-9) has been associated with poorer survival in patients with aggressive non-Hodgkin lymphomas. In EBV-related cancers the expression of viral latent membrane protein 1 (LMP1) correlates with an increased MMP-9 expression. In this study, we evaluated the prognostic relevance of MMP-9 expression and EBV status in HRS cells in patients with cHL in Brazil. Material and Methods: We selected 97 patients with cHL. Patients were included if they had: 1) > 18 years, 2) Undergone similar chemotherapy protocols, 3) Paraffin blocks available for review and for EBV and MMP-9 detection and 4) Clinical, epidemiological and laboratorial parameters available. Results: EBV was detected in 52.5% of all cases. MMP-9 expression positivity was found in 87.6% of all cases. There was no correlation between MMP-9 expression and EBV status. Response to treatment and relapse rate were independent of MMP-9 expression and EBV status. When stratified according to chemotherapy protocol used or disease stage, we still did not find any difference. MMP-9 positivity did not influence overall survival and event free survival. Conclusion: MMP-9 are expressed in the majority of HRS cells and did not correlated with EBV status or survival. The consistent MMP-9 expression in HRS cells makes this enzyme a potential target for therapy.
TEDE
BV UNIFESP: Teses e dissertações

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Baecklund, Eva. "Associations Between Rheumatoid Arthritis and Malignant Lymphomas." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5928.

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Liang, Chih-Lung, and 梁熾龍. "Regulation of Epstein-Barr Virus Gene Promoters in Type I Burkitt's Lymphoma Cells." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/84968235770041886428.

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博士
國立陽明大學
微生物暨免疫學研究所
89
Abstract Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus associated with many diseases including Burkitt掇 lymphoma (BL). In BL cells, EBV remains in a latent stage and can be induced to enter into lytic cycle by TGF-b. However, the mechanism of TGF-b-induced activation is not understood. In EBV-infected BL cells, the viral gene expression is limited only to oncogenic EBV-encoded nuclear antigen 1 (EBNA 1) gene, which is directed from a latent promoter Qp. EBV lytic cycle can be induced upon activation of a promoter Zp of BZLF 1 gene, which encodes Zta, a latent-to-lytic switching protein. By examining the regulation of both Qp and Zp in EBV latently infected BL cells by TGF-b here we present a functional analysis of TGF-b-induced lytic cycle of EBV. Yeast one-hybrid screen analysis revealed that Smad4 binds the -50 to -37 sequence of Qp. Sequence analysis also reveals a Smad4 binding element (SBE) located between -49 and -45 of Qp. Transient expression of Qp reporter construct in two EBV(+) BL cell lines, Rael and WW2, showed that Qp activity is repressed in response to the TGF-b reatment. This repression involves the interaction of Smad3/Smad4 complex and a transcriptional repressor, TGIF, as determined by co-immunoprecipitation and co-transfection with Qp and its SBE-site-specific mutant construct. In contrast, co-transfection experiments indicated that Zp is synergistically activated by Smad3/Smad4 and c-Jun/c-Fos, specifically in response to TGF-b treatment. TGF-b treatment of Rael cells results in a production of infectious EBV, which infects EBV(-) CA46 cells in vitro. These results suggest a mechanism of TGF-b induction of EBV lytic cycle through interaction of TGF-b effectors with the key viral genes and also suggest a role of TGF-b in EBV-associated diseases. Furthermore, yeast one 臿ybrid screen analysis using the ?0 to ?0 of Qp as the bait, a cDNA clone coding for a cellular transcriptional factor, HIV-EP2 was identified. However, the role of HIV-EP2 in Qp activity requires further investigation.

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Pinkert-Leetsch, Diana. "Funktionelle Analysen deregulierter Signalwege transformierter B-Lymphozyten - Das Epstein-Barr-Virus-Onkogen LMP1." Doctoral thesis, 2007. http://hdl.handle.net/11858/00-1735-0000-0006-AC5E-2.

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Die Entstehung verschiedener Tumorentitäten kann häufig mit einer vorliegenden Virusinfektion korreliert werden. So lässt sich beispielsweise ein Zusammenhang zwischen der Infektion mit den zur Gruppe der Herpesviren gehörenden Epstein-Barr-Viren (EBV) und der Entwicklung von Burkitt-Lymphomen, Hodgkin-Lymphomen sowie Nasopharynx-Karzinomen herstellen. Für die Transformation einer mit EBV infizierten humanen B-Zelle ist die Expression des Latenten Membranproteins 1 (LMP1) des Epstein-Barr-Virus essentiell. LMP1 ist ein Membranprotein mit einem funktionellen C-terminus, das Homologien zu den Tumornekrosefaktoren (TNF)- und Toll-like-Rezeptoren aufweist. Im Zusammenspiel mit anderen viralen Faktoren trägt LMP1 durch die von ihm aktivierten Signalwege (z.B. NF-κB, JNK, p38) zur Immortalisierung und malignen Entartung von EBV-infizierten Zellen bei. Einer dieser Signalwege ist der Jak/STAT-Signalweg. Da dessen EBV-abhängige Aktivierung bislang nur unzureichend geklärt ist, ist es Zielsetzung dieser Arbeit, die durch das Epstein-Barr-Virus vermittelte Aktivierung des Jak/STAT-Signalweges in Burkitt-Lymphomzellen näher zu untersuchen. Als Negativregulatoren des Jak/STAT-Signalweges sind hierbei die SOCS-Moleküle (Suppressor of Cytokine Signaling) von Bedeutung. Von besonderem Interesse sind dabei die Mechanismen der Aktivierung von SOCS3 durch LMP1 und dem damit verbundenen möglichen Einfluss auf den transformierten Zustand einer Zelle. In dieser Arbeit konnte gezeigt werden, dass in den untersuchten Burkitt-Lymphomzellen das exprimierte virale Onkoprotein LMP1 des Epstein-Barr-Virus ausreichend ist, den Jak/STAT-Signalweg zu aktivieren und SOCS3 zu induzieren. Die Aktivierung des Jak/STAT-Signalweges wird indirekt, das heißt über EBV-abhängig aktivierte Zytokinsignalwege, reguliert. Eine zusätzliche direkte Aktivierung durch eine Interaktion von Komponenten des Jak/STAT-Signalweges mit LMP1 kann derzeit jedoch nicht völlig ausgeschlossen werden.

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Lo, San-Ren, and 羅聖能. "Survival factor interference in Epstein-Barr virus-positive Burkitt’s lymphomas." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/8rk4x9.

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碩士
國立成功大學
生物化學研究所
92
Epstein-Barr virus (EBV), a world-wide human herpes virus, is highly associated with an increasing number of tumors and lymphoid diseases, such as Burkitt’s lymphoma (BL), nasopharyngeal carcinoma (NPC), Hodgkin’s disease, and infectious mononucleosis, and is able to establish life-long persistent infection. The EBV induced pathogenesis is strongly associated with viral proteins that contribute to cell immortalization and immune evasion. Previous studies have shown that disruptions of these viral proteins result in inhibitions of viral replication or transforming abilities, suggesting that these proteins are potential candidates as therapeutic targets. EBV nuclear antigen 1 (EBNA1) is required for maintenance of latent EBV infection and is essential for EBV-associated malignancies. It has been shown that disruption of EBNA1 causes apoptosis in EBV-positive BL cells, suggesting that EBNA1 serves as a survival factor in these cells. EBNA1 may, therefore, play a pivotal role in the onset, progression or maintenance of BL. Efficient inhibition of EBNA1’s function would likely prove useful in the therapy of EBV associated malignancies. Using an effective DNA vector-based siRNA expression system and efficient active siRNA screening strategy, we have identified two extremely potent siRNA molecules that can effectively trigger sequence-specific inhibition of EBNA1 expression. Transient co-transfection of target and siRNA-expression vectors into BHK and HEK293 cells caused a more than 90% reduction in EBNA1 production in both western blot and immunohistochemistry. It was further confirmed by fluorescent image that EGFP-carry cells as siRNA-expressing cells showed no EBNA1 detected by immunostaining. In addition, EBNA1 can transactivate promoter transcription in an orip-dependent way BHK and HEK293 cells. When we co-transfect siRNA-expressing vectors and reporter plamids into EBNA1 stable line, siA1-3 also inhibits reporter activity about 50%. Furthermore, we have successfully developed two viral vector, adenoviral and retroviral vectors, expect to achieve the best transfection efficiency.

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48

Chang, Kung-Chao, and 張孔昭. "The Role of Epstein-Barr Virus in Pathogenesis of Hodgkin Lymphoma." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/74949272896376841533.

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博士
國立成功大學
臨床醫學研究所
97
Hodgkin lymphoma (HL) is one of the most important human malignancies. It has been recognized since 1832 by Dr. Thomas Hodgkin, an English pathologist, and thereafter referred to as Hodgkin “disease” for more than 150 years. In contrast to other human lymphomas, in which the tumor cells are the main populations of the tumor constituents, the tumor cells of HL, called “Hodgkin (H)/Reed-Sternberg (RS)” cells, account usually for less than 10% of tumor bulk against an inflammatory background. The enigmatic RS cells are unique in their abundant cytoplasm and characteristic bilobed nuclei with eosinophilic prominent nucleoli, imparting an “owl-eye” appearance. The viral inclusion-like morphology puzzled pathologists and led to the finding of HL association with Epstein-Barr virus (EBV). The association of HL with EBV, however, is variable in different geographic regions. My thesis is therefore designed to explore the association of HL with EBV at different time period. Furthermore, the enigmatic pathogenesis of RS cells is investigated, especially its potential association with EBV. In my first period of study, we tried to clarify the EBV association with HL in Taiwan and Vietnam, a country popular for EBV infection. By comparing pathologic features and EBV status detected by in situ hybridization in 99 HL cases diagnosed between 1996-2007 with 74 HL diagnosed from 1982-1995, we found that EBV association rate in Taiwan HL was about 50% and more frequently found in old patients with non-nodular sclerosis type. There were an increased frequency of nodular sclerosis subtype, decreased frequency of the mixed cellularity subtype, and significant decrease in EBV positivity rates among the nodular sclerosis and lymphocyte depleted subtypes in the period of 1996-2007, as compared to that of 1982-1995, that is, there were shifts in the frequency of histologic subtype and EBV association of HL in Taiwan over the last decade, with a trend closer to that seen in Western countries and Japan. Interestingly, the association rate of EBV in Vietnamese childish HL cases is nearly 100%, including nodular lymphocyte-predominant (NLP) subtype, which always shows no association with EBV in Western HL cases. The high incidence of EBV in these cases of HL is correlated with an earlier mean age of presentation of primary EBV infection, i.e. infectious mononucleosis, at 5.3 years old, in this patient population, compared to an average of 15-19 years old reported in developed countries. Our study demonstrates that in an area with an earlier mean age of onset of EBV infection, nearly all cases of pediatric HL, including all histological patterns, may be related to EBV infection. It implies an important role for environmental factors in the pathogenesis of HL. In the second stage of study, we tried to investigate the mechanism underlying the characteristic multinucleated RS cells. Since endoplasmic reticulum (ER) stress has been found to induce aberrant, cytoplasmic cyclin A expression, which will interact with Cdk2 to induce centrosome overduplication, leading to nuclear hyperdiploidy, we tested whether the aberrant expression of cyclin A is related to the RS morphology of HL cells. We found, by immunohistochemistry on 34 cases of HL, that aberrantly cytoplasmic expression of cyclin A, a cell cycle regulator, was associated with RS cell morphogenesis in both EBV-positive and -negative HL cases. In vitro, EBV-LMP1 induced cytoplasmic expression of cyclin A with an increase of multinucleated cell morphology in an EBV-negative HL cell line, L-428. Therefore, the aberrant expression of cyclin A is commonly associated with RS cell morphology in HL, probably through LMP1 signaling or other similar mechanisms in EBV-negative cases. We also demonstrate for the first time that the majority of HL cases expressed survival (GRP78 and XBP1) but not death (CHOP and ASK1) signals of endoplasmic reticulum (ER) stress in all histologic subtypes of HL and in both EBV-positive and –negative cases at a similar level. LMP1 transfection increased expression of GRP78 and XBP1 in L-428 cell line. Although, expression of ER signals did not bear prognostic significance, it may rescue HL cells from stress-induced cell death. Thus, surviving ER stress may be involved in the pathogenesis of HL. My PhD study therefore successfully finished the epidemiology of the association of EBV with HL in Taiwan and in Vietnam, and proposed a theory or mechanism to explain the characteristic RS morphology of HL.

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49

Naidoo, Sharlene. "Laboratory diagnosis of Epstein Barr Virus in diffuse large B cell lymphoma." Thesis, 2017. https://hdl.handle.net/10539/24731.

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A dissertation submitted to the Faculty of Health Sciences, University of Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in the branch of Anatomical Pathology. 21 July 2017.
Aims and objectives The study design aimed to assess and validate various laboratory techniques in the detection of EBV in HIV positive patients with diffuse large B cell lymphoma. The sensitivity and specificity of each technique was determined, as was the presence of an asymptomatic (latent) or lytic phase infection and the viral strain. DLBL samples occurring in HIV seropositive patients were used as a vehicle for these laboratory procedures which included chromogenic in situ hybridisation (EBER), immunohistochemistry (EBNA 2, LMP 1), real time PCR, (EBNA 1, LMP 2 and BZLF 1) and nested PCR (EBNA 2). Materials and Methods 46 cases of previously diagnosed DLBL from HIV positive individuals were identified and retrieved from the archives of the Department of Anatomical Pathology of the University of Witwatersrand and NHLS. All in-situ hybridisation, immunohistochemical and PCR laboratory procedures were carried out in accordance with the Standard Operating Procedures of the Anatomical Pathology Molecular Laboratory, using appropriate negative and positive controls throughout. Ethical clearance was obtained (M140273). Results/Conclusion A 20% frequency of EBV in HIV positive DLBL cases was established. All EBV infections were found to be in the lytic phase, with an almost equal distribution of latency patterns II and III and an equal distribution of EBV strains 1 and 2. EBER in situ hybridisation was confirmed to be the most sensitive and reliable method of viral detection, and the presence of the BZLF 1 gene determined by real time PCR was found to be a reliable indicator of a lytic infection.
LG2018

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50

Niller, Hans Helmut [Verfasser]. "Wie verursacht das Epstein-Barr-Virus Tumore? : ein neues molekulares Modell der Entstehung des Burkitt-Lymphoms / vorgelegt von Hans Helmut Niller." 2003. http://d-nb.info/1001962540/34.

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