Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-09-26T14:57:43Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese - Aurora Del Carmen R. Soria.pdf: 1359045 bytes, checksum: 15293f7897fb65bcb5cac643cf5347fb (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-09-26T14:57:55Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese - Aurora Del Carmen R. Soria.pdf: 1359045 bytes, checksum: 15293f7897fb65bcb5cac643cf5347fb (MD5) / Made available in DSpace on 2017-09-26T14:57:55Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese - Aurora Del Carmen R. Soria.pdf: 1359045 bytes, checksum: 15293f7897fb65bcb5cac643cf5347fb (MD5) Previous issue date: 2015-12-18 / Tuberculosis demands today great sanitary importance due to it’s high prevalence and lethality. It possesses antimicrobial resistance and hits vulnerable populational groups. The Cytomegalovirus (CMV) and the Epstein-Barr virus (EBV), after initial exposure, are capable of establishing latency in the tissues, causing modulatory effects on the immune system, allowing protection against intercurrent infections, but enabling cancer and autoimmunity in individuals with a favorable genetic backround. This work is a controlled case study aiming to verify if the viral co-infection by EBV and CMV have any influence on the onset of Tuberculosis (TB). IgG and IgM serology were carried out for EBV and CMV, also viral genome research through the Polymerase Chain Reaction technique in real time on the plasma of TB patients, and controls (subjects that had interdomiciiary contact with index cases of TB). 68 patients participated, ages ranging from 18 to 36 years and 56 paired controls. It was observed that 100% of cases and controls had positive IgG for EBV; and that 100% of cases and 96,4% of controls were IgG positive for CMV. Therefore, in that small transversal sampling the high prevalence of infection by EBV and CMV was confirmed, but not an association between the infection/latency of the viruses and the occurrence of TB. Low presence of the viral genome on the plasma was verified: 7 occurrences in the cases (10,3%) and 9 in the controls (16,1%). Despite the numerical difference, maybe highliting a tendency, there was no statistical significance. It is important that this study continues, in this way, in a longitudinal cohort of exposed individuals (home infected), with higher “n” sampling, and a smaller populational age range, that houses more prevalence of seronegatives exposed to EBV and CMV, allowing observation of the contrast with seropositives. / A tuberculose se investe na atualidade de grande importância sanitária devido a sua alta prevalência e letalidade. Possui resistência e acomete grupos populacionais vulneráveis. O citomegalovírus (CMV) e o vírus Epstein Barr (EBV), após a aquisição inicial, são capazes de estabelecer latência nos tecidos, provocando efeitos modulatórios no sistema imune, podendo proteger de infecções intercorrentes, mas favorecendo o câncer e a autoimunidade em indivíduos com o background genético favorável. O presente trabalho é um estudo de caso controle com o objetivo de verificar se a coinfecção viral pelo EBV e CMV influencia no aparecimento da Tuberculose (TB). Procedeu-se à sorologia IgG e IgM para EBV e CMV, e à pesquisa do genoma viral por meio da técnica de Reação em Cadeia da Polimerase em tempo real no plasma de pacientes com TB e controles (indivíduos que tiveram contacto intradomiciliar com casos index de tuberculose). Participaram 68 pacientes com idade entre 18 a 36 anos e 56 controles pareados. Observou-se que 100% de casos e controles eram IgG positivos para EBV; 100% de casos e 96,4% de controles eram IgG positivos para o CMV, portanto, nessa pequena amostragem transversal, confirmou-se a alta prevalência da infecção pelo EBV e CMV, mas, não se observou associação entre a infecção/latência dos vírus e a ocorrência de tuberculose. Verificou-se baixa presença do genoma viral no plasma: 7 ocorrências nos casos (10,3%) e 9 ocorrências nos controles (16,1%). Apesar da diferença numérica, talvez mostrando uma tendência, não houve significância estatística. É muito importante a continuidade do estudo, desta feita em uma coorte longitudinal de indivíduos expostos (contactantes domiciliares), com maior “n” amostral, e faixa etária populacional menor, que comporte maior prevalência de expostos soronegativos para o EBV e CMV, permitindo observar contraste com expostos seropositivos.

Made available in DSpace on 2014-06-12T18:31:28Z (GMT). No. of bitstreams: 2 arquivo8027_1.pdf: 926372 bytes, checksum: e830629d4ed372e5353a6511714c0fab (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003 / O Vírus Epstein-Barr (VEB) pertence à família de Herpesviridae, tem distribuição mundial e, aproximadamente 90% da população adulta, mostra evidência de infecção passada. O VEB causa a mononucleose infecciosa e doenças linfoproliferativas em pacientes imunocomprometidos. O propósito deste estudo foi determinar a prevalência de anti-VEB IgG em crianças atendidas no Hospital das Clínicas da Universidade Federal de Pernambuco (UFPE). Foram detectados, pela técnica ELISA, anticorpos IgG contra o antígeno do capsídeo viral (VCA). O teste utilizado foi o Enzygnost EBV Kits (Virotech, Alemanha). Um total de 381 crianças, com idade variando entre 8 meses e 12 anos (idade média 6,2 anos), 224 (58,8%) do sexo masculino e 157 (41,2%) do sexo feminino, foram analisados. Os anticorpos anti-VEB foram detectados em 86,1%(328/381) das crianças. Esses resultados indicam que as crianças abaixo dos doze anos de idade foram infectadas pelo VEB, mostrando uma alta prevalência nessa área de Hospital das Clínicas / Recife. A idade, o número de adolescentes no domicílio e a freqüência escolar mostraram associação estatisticamente significativa com o VEB nos pacientes estudados

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), occurring in isolated attacks or progressive forms. Many observations implicate Epstein-Barr virus (EBV) in the pathogenesis of MS. With the relentless accumulation of evidence for a significant pathogenic role of EBV in MS, I believe it may be possible to prevent and cure MS by effectively controlling EBV infection. Currently, monoclonal antibodies (MAb) are used as therapeutics for a molecular targeted approach to slowing disease progression in MS. However, to my knowledge, there have been no antibodies targeted against EBV infection in any model of MS. The objective of this study is to determine whether or not a MAb against EBV could be a therapeutic target for EAE. In this study, I will propose an experiment that will examine the effects of intraperitoneal injection of MAb F-2-1 in 2-month-old new humanized BALB/c Rag2-/- ll2rg-/- (BRG) adult EBV/EAE male mice. My expected results suggest that mice with EBV/EAE + MAb F-2-1 may have an attenuated clinical disease course. Through immunohistochemical studies, I will also propose that MAb F-2-1 may decrease inflammation, demyelination and axonal loss in the CNS of mice with EAE. I believe that this novel treatments success would depend on MAb F-2-1’s ability to inhibit clonal expansion of EBV-infected autoreactive B cell in the CNS. Ultimately, my proposed experiment suggests that inhibition of virus-cell fusion of EBV to the B cell membrane might attenuate neuropathology in EAE. I hope that my prospective study highlights the importance of controlling EBV in patients with MS and provides grounds for optimism on how to successfully treat MS by controlling EBV infection. In conclusion, by proposing an alternative therapeutic approach, I hope that this hypothetical experiment will aid in future investigations that could further our knowledge on treatment and prevention of multiple sclerosis

Epstein-Barr Virus (EBV) is well known to manipulate the host ubiquitin machinery to facilitate its latent persistence and oncogenesis, exemplified by LMP1 signal transduction that activates multiple transcription factors, including NFκB, AP1, and IRF7/IRF4, which promote cell survival and outgrowth, and control immune response and inflammation. It is therefore vital to delineate the detailed mechanisms underlying LMP1 signal transduction for understanding EBV-mediated oncogenesis. p62 (also called SQSTM1, Sequestosome 1) is a ubiquitin sensor and a signal transducing adaptor that interacts with TRAF6 and facilitates the recruitment of ubiquitinated signal intermediators for the activation of NFκB and AP1 in diverse contexts. In turn, p62 is induced by NFκB. However, the interaction between p62 and EBV latency has never been studied. We have recently published interesting and important results, which imply a crucial role for p62 in EBV-mediated oxidative stress. In this study, we further show that p62 is upregulated in EBV latency, with the contribution of LMP1-mediated NFκB and AP1 activities. In turn, p62 participates in LMP1 signal transduction through its interaction with TRAF6, promoting TRAF6 ubiquitination. shRNA-mediated p62 depletion downregulates LMP1-TRAF6 interaction and TRAF6 ubiquitination, and significantly impairs AP1 activity; however, with no detectable effects on NFκB activity. These observations imply that TRAF6-p62 interaction differentiates LMP1 signaling to NFκB and AP1 activation. As a consequence, p62 depletion promotes etoposide-induced apoptosis. These findings identify p62 as a novel player in EBV LMP1 signaling to AP1 activation that is crucial for LMP1-mediated ROS production.

Purification of Epstein-Barr virus-associated deoxyribonuclease (EBV-DNase) from Raji and P3HR-1 cells treated with 12-0-tetradecanoylphorbol-13-acetate and sodium butyrate was performed by sequential ion-exchange column chromatography and fast protein liquid chromatography. The enzyme activity, protein concentration, yield, specific activity, purification profiles, and polypeptide patterns by electrophoretic analysis in each column purification step were determined. The characteristics of the partially isolated EBV-DNase were demonstrated by the enzyme activity, DNA binding affinity, and inhibition by the nasopharyngeal carcinoma patient sera and rabbit polyclonal antibodies against the partially purified EBV-DNase. A nonisotopic assay was developed as a new method in detecting the nuclease. EBV-DNase was purified to homogeneity by FPLC. The molecular weight of the EBV-DNase was 58 KDa as determined by sodium dodecylsulfate polyacrylamide gel electrophoresis, immunostaining, and radioimmunoprecipitation using nasopharyngeal carcinoma patient sera and rabbit polyclonal antibodies.

The dissertation investigates the wide class of Epstein zeta-functions in terms of uniform distribution modulo one of the ordinates of their nontrivial zeros. Main results are a proof of a Landau type theorem for all Epstein zeta-functions as well as uniform distribution modulo one for the zero ordinates of all Epstein zeta-functions asscoiated with binary quadratic forms. / Die vorliegende Arbeit untersucht, bei welchen Epsteinschen Zetafunktionen die Imaginärteile der nichttrivialen Nullstellen gleichverteilt modulo eins sind. Als zentrales Ergebnis wird dies für alle Epsteinschen Zetafunktionen, die durch binäre quadratische Formen gebildet werden, bewiesen. Außerdem wird unter anderem Landau's Theorem für alle Epsteinschen Zetafunktionen gezeigt.

Le virus Epstein-Barr (EBV) est un virus herpès oncogène causant la mononucléose infectieuse et est associé à différents types de cancer d'origine épithélial et lymphoïde. Nous avons précédemment démontré que EBV peut infecter et se répliquer dans les monocytes humains. Suite à cette infection, plusieurs fonctions importantes du monocyte s'en trouvent affectées, dont la phagocytose, la biosynthèse de prostaglandine E2 et la production de TNF-oc et d'IFN-a. Il est bien connu que l'IFN de type I (IFN-a/(3) est un puissant médiateur antiviral qui est rapidement sécrété par les cellules infectées lors des stades précoces de l'infection. OBJECTIFS Ce projet vise à caractériser le(s) mécanismes(s) affectant la production d'IFN-a par les monocytes humains infectés par le virus EBV en étudiant notamment la cascade d'activation des protéines JAKs et STATs. MÉTHODES Nous avons évalué l'effet de l'infection des monocytes humains par EBV sur l'activation des facteurs de transcription IRF-3 et IRF-7, sur les protéines de la cascade des JAKs-STATs Qakl, Tyk2, Statl et Stat2) ainsi que sur les protéines SOCS. RÉSULTATS L'activation des protéines IRF-3 et IRF-7 n'est pas affectée, puisqu'il a été possible d'observer une translocation nucléaire de ces facteurs de transcription suite à l'infection par EBV. Cependant, la boucle d'amplification de la voie des JAKs-STATs est supprimée suite à l'inhibition de la phosphorylation de Statl. Le mécanisme d'inhibition de la synthèse d'IFN-a par le virus EBV dans les monocytes humains implique l'activation de la protéine SOCS-3. CONCLUSION Ce projet permet d'approfondir nos connaissances sur les mécanismes immunosuppresseurs mis en œuvre par EBV afin de supprimer les fonctions monocytaires. / Epstein-Barr virus (EBV) is an oncogenic herpesvirus recognized as the causative agent of infectious mononucleosis and is associated with several human malignancies. We have recently provided evidences that human monocytes were permissive to EBV infection and replication. Following infection, EBV can affect various cellular functions of monocytes, such as phagocytosis, biosynthesis of prostaglandins E2 and production of TNF-a and IFN-a. The type I interferon System (IFN-a/p) represents an important elements of host defence against ail kinds of pathogens, mainly viruses. Following infection, virus-infected cells rapidly produce and secrete IFN-a/p. OBJECTIVES The present work aims to determine the mechanism affecting the IFN-a production by the EBV-infected monocytes, in particular by the study of the JAK-STAT pathway. METHODS We examined the effect of EBV infection in monocytes on IRF-3 and IRF-7 nuclear accumulation, on JAKs and STATs proteins activation (Jakl, Tyk2, Statl and Stat2), and on SOCS proteins expression. RESULTS The IRF-3 and IRF-7 activation is not affected, since it was possible to observe a nuclear translocation of these transcription factors following EBV infection. However, the positive-feedback loop of the JAK-STAT pathway was found to be affected by the inhibition of Statl phosphorylation. The mechanism of IFN-a inhibition in EBV-infected monocytes involves the SOCS-3 protein activation. CONCLUSION Further description of EBV inhibitory mechanisms on monocytes immune functions would certainly improve our understanding of the role of these cells in the early stages of EBV pathogenesis.

L’ADN dans nos cellules est exposé continuellement à des agents génotoxiques. Parmi ceux-ci on retrouve les rayons ultraviolets, les agents mutagènes chimiques d’origine naturelle ou synthétique, les agents radiomimétiques, et les dérivés réactifs de l’oxygène produits par les radiations ionisantes ou par des processus tels que les cycles métaboliques redox. Parmi les dommages infligés par ces agents, les plus dangereux sont les cassures simples- et double-brin de l’ADN qui brisent son intégrité et doivent être réparées immédiatement et efficacement afin de préserver la stabilité et le fonctionnement du génome. Dans la cellule, ces cassures sont formées et réparées au niveau de la chromatine, où l'environnement moléculaire et les évènements impliqués sont plus complexes et les systèmes expérimentaux appropriés pour leur exploration sont peu développés. L’objectif de ma recherche visait ainsi l’exploration de ces processus et le développement de nouveaux modèles qui nous permettraient d’étudier plus précisément la nature de la formation et de la réparation des cassures simple- et double-brin de l’ADN in vivo. J’ai utilisé comme modèle un minichromosome (l’episome du virus Epstein-Barr) d’environ 172 kb, qui possède toutes les caractéristiques de la chromatine génomique. Nous avons observé que la radiation gamma induit un changement conformationnel de l’ADN du minichromosome par la production d’une seule cassure double-brin (CDB) localisée de façon aléatoire. Une fois linéarisé, le minichromosome devient résistant à des clivages supplémentaires et par la radiation ionisante et par d’autres réactifs qui induisent des cassures, indiquant l’existence d’un nouveau mécanisme qui dépend de la structure chromatinienne et par lequel une première CSB dans le minichromosome confère une résistance à la formation d’autres cassures. De plus, la reformation des molécules d’ADN du minichromosome surenroulées après l’irradiation indique que toutes les cassures simple-brin (CSB) et CDB sont réparées et les deux brins fermés de façon covalente. Nos découvertes indiquent que la réparation par ligature d'extrémités d'ADN non homologues est le principal mécanisme responsable de la réparation des CDB, alors que la réparation des CSB est indépendante de la polymérase poly-ADP ribose-1 (PARP-1). La modélisation mathématique de la cinétique de réparation et le calcul des vitesses de réparation a révélé que la réparation des CSB est indépendante de la réparation des CDB, et représente l’étape limitante dans la réparation complète des minichromosomes. Globalement, nous proposons que puisque ce minichromosome est comparable en longueur et en topologie aux boucles d’ADN sous contrainte de la chromatine génomique in vivo, ces observations pourraient fournir une vision plus détaillée de la cassure et de la réparation de la chromatine génomique. / DNA in our cells is exposed continually to DNA-damaging agents. These include ultraviolet light, natural and man-made mutagenic chemicals, and reactive oxygen species generated by ionizing radiation or processes such as redox cycling by heavy metal ions and radio-mimetic drugs. Of the various forms of damage that are inflicted by these mutagens, the most dangerous are the single- and double-strand breaks (SSBs and DSBs) which disrupt the integrity of DNA and have to be repaired immediately and efficiently in order to preserve the stability and functioning of the genome. In the cell, induction and repair of strand breaks takes place in the context of chromatin where the molecular environment and the events involved are more complex and suitable experimental systems to explore them are much less developed. A major focus of my research was therefore aimed towards exploring these processes and developing new models which will allow us to look more precisely into the nature of induction and repair of SSBs and DSBs in DNA in vivo. We used as a model the naturally-occurring, 172 kb long Epstein-Barr virus (EBV) minichromosome which posses all the characteristics of genomic chromatin and is maintained naturally in Raji cells. Gamma-irradiation of cells induces one, randomly-located DSB and several SSBs in the minichromosome DNA, producing the linear form. The minichromosome is then resistant to further cleavage either by ionizing radiation or by other break-inducing reagents, suggesting the existence of a novel mechanism in which a first SSBs or DSBs in the minichromosome DNA results in a conformational change of its chromatin which confers insensitivity to the induction of further breaks. Supercoiled molecules of minichromosome DNA were reformed when cells were incubated after irradiation, implying that all SSBs and DSBs were repaired and both strands were covalently closed. Using specific inhibitors or siRNA depletion of repair enzymes, we found that Non Homologous End Joining was the predominant pathway responsible for DSB repair, whereas repair of SSBs was PARP-1 independent. We could also show clearly that topoisomerases I and II are not required for repair. Mathematical modeling of the kinetics of repair and calculation of rate constants revealed that repair of SSBs was independent of repair of DSBs and was the rate-limiting step in complete repair of minichromosomes. Overall, we propose that since this minichromosome is analogous in length and topology to the constrained loops which genomic chromatin is believed to form in vivo, these observations could provide more detailed insights into DNA breakage and repair in genomic chromatin.

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