Orientador: Maria Marluce dos Santos Vilela / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-10T20:47:23Z (GMT). No. of bitstreams: 1 Toro_AdyleiaAparecidaDalboContrera_D.pdf: 3459466 bytes, checksum: a2a86bc660c9851dab70414f47dc5420 (MD5) Previous issue date: 2008 / Resumo: INTRODUÇÃO: A infecção pelo HIV desencadeia diversificadas e extensas alterações no mecanismo de defesa do pulmão, o que se traduz em maior número de infecções por germes habituais ou oportunistas e processos imunológicos diversos como a pneumonia intersticial linfocítica (PIL), a hiperplasia linfóide (HLP) ou neoplasias. A infecção simultânea do HIV e do EBV pode aumentar o risco de HLP/ PIL. OBS.: O resumo na integra poderá ser visualizado no link ou texto completo da tese digital / Abstract: BACKGROUND: Pulmonary Lymphoid Hyperplasia (PLH) / Lymphoid Interstitial Pneumonitis (LIP) complex is common in HIV infected children. It may reflect a particular response to HIV from a developing immune system, and is also related to exposure to Epstein-Barr virus (EBV). Note: the complete abstract is avaiable with the link or full eletronic digital theses or dissertations / Doutorado / Pediatria / Doutor em Saude da Criança e do Adolescente

O Epstein-Barr vírus (EBV) é a única espécie humana pertencente ao gênero Lymphocryptovirus. A transmissão ocorre através da saliva contaminada e geralmente ainda na infância. Nosso estudo analisou 165 amostras clínicas de pacientes, portadores de HIV, em tratamento com antiretrovirais, atendidos no Sistema Hospitalar do Sistema Penitenciário do Estado de São Paulo. Nosso enfoque foi pesquisar o EBV nas células mononucleares do sangue periférico, através das técnicas de PCR, Nested-PCR e seqüenciamento de nucleotídeos. Os resultados obtidos, indicaram que 11,51% (19) das amostras analisadas, apresentaram-se positivas para o EBV. Essas 19 amostras, foram seqüenciadas com primers específicos para a região da EBNA-1 (Epstein Barr Nuclear Antigen 1). As amostras foram alinhadas com o auxílio do DNASTAR. Ao alinharmos as amostras, encontramos uma troca de base (de G para A) em 7 amostras e essa troca não alterou a conformação da proteína EBNA-1. Na análise filogenética de nossas sequências com as depositadas no GenBank, foi possível observar dois grupos, que representam tipo 1 e o tipo 2 do EBV. 100% das amostras estudadas por nós foram identificadas como pertencentes ao grupo que caracteriza o tipo 2. Sendo assim, as 7 amostras que apresentaram a troca sugerem a origem um novo subtipo. / The Epstein-Barr Virus (EBV) is the only species to the genus Lymphocriptovirus that infects humans. One of the possible route for its transmission thought by contamined saliva and usually occurs in the childhood. This study analysed 165 clinical samples from HIV infected patients, treated by HARRT, attended in the Hospitalar System in the Penitentiary System from Sao Paulo State. The aim of this study was to search EBV in peripheral blood mononuclear cells by PCR, Nested-PCR and sequencing analysis. The results showed 11,51% of the analysed samples, positive for EBV. This samples, was sequenced with specifics primers from the EBNA-1 (Epstein Barr Nuclear Antigen 1) region. The samples were aligned by DNASTAR program. The aligned sequences showed the base conversion G to A in seven samples. This conversion caused no alteration in the EBNA-1 protein conformation. In the phylogenetic analysis the studied sequences with the sequences from GenBank was possible to observe two groups represented with type 1 and type 2 from EBV. 100% the samples studied was identified with the group characterized by the type 2 to EBV. So the seven samples showed the conversion, suggesting the origin of the one new subtype.

Orientadores: Laura Sterian Ward, Alfio José Tincani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T20:17:52Z (GMT). No. of bitstreams: 1 Almeida_JacquelineFatimaMartins_M.pdf: 2198135 bytes, checksum: 94a76c347fc27e9b1fc05d077aa728a0 (MD5) Previous issue date: 2014 / Resumo: Agentes biológicos causadores de neoplasias humanas têm sido alvo de pesquisas científicas nos últimos anos, especialmente os vírus, considerados responsáveis pela causa de cerca de 20% de todos os tipos de cânceres em geral. No entanto os mecanismos pelos quais estes vírus causam tumores variam dependendo do tipo de sua espécie, da célula alvo e de fatores que concernem ao hospedeiro. Os herpes vírus, como o Herpes Simplex Virus tipo 2 (HSV-2), Epstein-Barr vírus (EBV), Citomegalovirus (CMV) e Herpesvirus Humano tipo 8 (HHV-8) têm sido associados com diversas neoplasias malignas e também com doenças autoimunes tireoidianas. O objetivo do nosso trabalho foi verificar a presença da infecção destes herpes vírus em nódulos tireoidianos benignos e malignos procurando indícios de uma possível associação com tumores tireoidianos. Foram coletadas amostras de tecido tumoral tireoidiano e soro de 153 portadores de nódulos de tireoide (136 mulheres e 17 homens, 46±15 anos) incluindo 65 tumores benignos (48 bócios, 17 adenomas foliculares e 09 portadores de doença tireoidiana autoimunes sendo 02 doenças de Graves e 07 Hashimotos) e 79 tumores malignos (78 carcinomas papilíferos e 01 carcinoma folicular). Também obtivemos 75 tecidos tireoidianos normais extraídos do lobo contralateral da lesão em 75 tumores. Foi realizada análise sorológica por ELISA para detecção de anticorpos dos herpes vírus e foi realizada análise da Carga Viral por PCR em Tempo Real. Quarenta e cinco (29,4%) pacientes (45/153) possuíam anticorpos anti-HSV2; 83,7% anti-CMV (128/153); 98% anti-EBV (150/153) e nenhum paciente possuía anticorpos anti-HHV8, o que é compatível com as estimativas esperadas na população brasileira. As concentrações de anticorpos anti-EBV foi, em média maior do que o do HSV-2 e do que o do CMV (p<0,0001). Os herpes vírus HSV-2, CMV e HHV-8 não foram encontrados em nenhum tecido tireoidiano da população estudada. No entanto, encontramos sequências de DNA do EBV em 20 amostras de tecidos tireoidianos (04 bócios, 03 DAIT e 13 CP). Embora a carga viral média fosse de 1068 cópias/µg nos casos malignos e de 374 cópias/µg nos casos benignos, esta diferença não se mostrou estatisticamente significante. Foram encontrados também 6/75 (8%) casos positivos para a infecção por EBV nos tecidos normais. A carga viral foi, em média, maior nos tumores (126,5 cópias/µg) do que em seus respectivos tecidos normais (93 cópias/µg; p=0,0207). Não houve correlação entre a presença de EBV e as características clínicas ou de evolução dos pacientes. Embora, para melhor compreensão de seus mecanismos de ação, sejam necessários novos estudos moleculares e microbiológicos, a presença da alta carga viral do EBV nos tecidos tumorais tireoidianos em relação aos tecidos normais correspondentes sugere que este vírus pode exercer um papel no desenvolvimento de nódulos tireoidianos / Abstract: Biological agents that cause human cancers have been the subject of scientific research in recent years, especially viruses considered to be responsible for the cause of about 20% of all cancers in general. Although the mechanisms of latent infection and carcinogenesis vary depending on the particular virus, target cells, and host factors. Herpesviruses, such as Human Simplex Virus type 2 (HSV-2), Epstein - Barr virus (EBV), Cytomegalovirus (CMV) and Human Herpes Virus type 8 (HHV-8) have been associated with human malignancies and also with thyroid autoimmunity. We aimed to analyze the presence of these viruses in benign and malignant thyroid nodules looking for evidence of a possible association with thyroid tumors. Serum and thyroid specimens were prospectively collected from 153 thyroid nodule patients (136 females and 17 males, aged 46±15 years) including 78 papillary thyroid cancers (PTC), 01 follicular thyroid cancer (FTC), 17 follicular adenomas and 48 goiters. We used ELISA to screen all patients for the presence of the viruses and a real-time quantitative PCR (qPCR) technique to analyze thyroid tissues viral load on antibody-positive patients. Forty-five (29.4%) patients (45/153) presented anti-HSV2 antibodies; 83.7% anti-CMV (128/153); 98% ani-EBV (150/153) e no patient presented antibodies anti-HHV8, which would be expected to be found in Brazilian population in general. In both malignant and benign groups the medians of antibodies anti-EBV were higher than HSV-2 and CMV medians (p<0,0001). There was no evidence of the presence of HSV-2, CMV and HHV-8 in the population studied. Nevertheless we found EBV¿s DNA sequences in 20 thyroid tissue samples. Even though the average malignant viral load was 1068 copies/µg in 13 cases and 374 copies/µg in 7 benign cases, there was no statistically significant difference between groups. We also found 6 (8%) positive cases for EBV viral load out of 75 normal tissues. In paired test the viral load median was higher in tumors (126.5 copies/µg) than in their respective normal tissues (93 copies/µg; p=0.0207). We did not find any association among the presence of EBV and/or its viral load and any clinical or pathological feature. Althought molecular studies are needed to a better comprehension of the mechanisms underlying the relation between EBV and thyroid nodules, the presence of high EBV copy numbers in thyroid tumors, especially in PTC cases, in comparison with normal tissues, suggests that this virus may play a role in the development of thyroid nodules / Mestrado / Clinica Medica / Mestra em Clínica Médica

One out of several distinguishing features of multiple sclerosis (MS) is the epidemiological variation of geographic distribution. Population-based studies on the prevalence and incidence of MS in Sweden have previously been performed only in Göteborg. Another feature of MS is the clinical variation between individuals. To a large extent data on the clinical characteristics of MS come from studies on cases frequenting MS clinics and therefore, may be biased. Also rare are population-based studies of the consequences of MS-related incapacity on socio­economic factors. As for MS aetiology, both environment and genes are involved. Human herpesviruses are often the main suspected environmental aetiological agents. Our aim was to estimate the prevalence of MS in Västerbotten County for 1 January 1990, the incidence during a 10-year period 1988-97, and the prevalence 31 December 1997; and also to present detailed clinical data including onset symptoms and the disability distribution for the latter two MS populations. Furthermore, we wanted to estimate the prevalence of sick leave, professional assistance, and housing; and also, to study the risk factors for sick leave. In order to investigate the association between MS and human herpesviruses, samples were identified in two regional population-based serumbank registers. This linkage identified samples collected from before MS-onset in 73 MS cases and after MS onset in 161 cases The prevalence and incidence populations were identified through multiple sources. Diagnostic ascertainment, the reliability of clinical data, and additional information were assured from a questionnaire with follow-up interview and neurological examination. The onset adjusted crude prevalence of MS was 125/100,000 (95% CI: 112-140) in January 1990, and 154/100,000 (95% Cl: 139-170) in December 1997. The increase was mainly attributable to a higher incidence than mortality. The crude incidence rate 1988-97 was 5.2/100,000 (95% CI: 4.4-6.2). The disability distribution in the 1997 prevalence population in Västerbotten was compared to the disability distribution in a Canadian MS population, which has been used for publications on the natural history of MS. One difference from the Canadian studies appears to be the better recognition of cases with more benign disease. Nevertheless almost half of prevalent MS cases aged 18-64 years were fully sick-listed, and one-fourth of all prevalent cases received professional assistance. High disability level was the strongest predictor for sick leave. All MS cases showed signs of past Epstein-Barr virus (EBV) infection. High activity to EBV (EBNA-1 but not VCA) and human herpesvirus 6 (HHV-6) significantly (borderline significance for HHV-6) increased the risk to develop MS. These estimates show that Västerbotten County is a high risk area for MS. Both incidence and prevalence were significantly higher when compared to estimates from Göteborg. The comparison with the Canadian MS population shows that MS might be a slightly more benign disease than previously recognized. Still, the consequences of MS regarding socio-economic aspects are considerable. We suggest that EBV is a prerequisite for the development of MS. Individuals that will develop MS exhibit an altered immune response against the EBV virus characterised by high activities to EBNA-1 in the absence of high VCA activities, this being most pronounced in the five-year period preceding MS onset. A pathogenetic role is suggested for EBV and remains possible also for HHV-6. / digitalisering@umu

Le virus d'Epstein-Barr (EBV), est un gamma herpes virus exclusivement humain qui infecte près de 95% de la population adulte. EBV établit un cycle de latence dans les cellules B mémoires et les cellules épithéliales. EBV entre périodiquement dans une réplication lytique avec sécrétion des virions dans la salive. L’infection EBV est associée à l’apparition de lymphomes, de cancers et de maladies auto-immunes. Les conditions favorisant le développement de ces pathologies restent mal connues mais l’immunodépression et potentiellement l’activation des lymphocytes B nécessaire à la réplication d’EBV jouent un rôle clé.Nous avons examiné l’association entre activation des cellules B dans le compartiment systémique et le contrôle sur le réservoir de l’EBV. Deux situations cliniques d’activation chronique des cellules B ont été explorées ; le syndrome de Gougerot-Sjögren et la mastite subclinique dans le contexte de l’infection par le VIH.Dans ce travail de thèse, nous avons tout d’abord développé une PCR en temps réel pour la quantification de l'ADN de EBV ciblant la région répétée BamHI-W du génome. Le travail de validation de la technique a permis d’évaluer précisément le gain de sensibilité comparativement à une qPCR LMP2 (cible unique). L’impact des variations de répétition de la séquence BamHI-W suivant les souches et isolats EBV a également été analyse.Dans un deuxième travail, nous avons montré que, la mastite subclinique était fréquente au cours de l’allaitement et qu’elle était un facteur indépendant associé à une augmentation de l'excrétion EBV par le lait maternel. Cette sécrétion est associée localement à l’inflammation et à l’excrétion du VIH ce qui témoigne de phénomène de synergie entre les deux virus. Nous avons également démontré que l'ADN EBV dans le lait maternel peut être résistant à la DNase et que le virus était est probablement encapsidé dans le lait, donc potentiellement infectieux.Enfin, bénéficiant d’un accès aux prélèvements de la cohorte ASSESS nous avons recherché de possible anomalie du contrôle de l’infection EBV dans le compartiment sanguin au cours du syndrome de Gougerot-Sjögren primaire dans lequel les lésions glandulaires salivaires et lacrymales sont associées à la présence d’EBV. Nous avons démontré que le réservoir EBV et la réplication EBV dans le compartiment systémique sont bien contrôlées au cours du syndrome de Gougerot-Sjögren primaire. La réponse anticorps contre l’antigène précoce d’EBV (EA) n'était pas associée à une augmentation de l'ADN de EBV.Ce travail de thèse, souligne le lien entre l'activation des lymphocytes B, l'inflammation chronique et le contrôle sur le réservoir d’EBV. Dans la glande mammaire le contrôle de l’infection EBV est perturbé en cas de mastite subclinique. Au contraire dans le syndrome de Gougerot-Sjögren l’infection reste bien contrôlée dans le compartiment sanguin malgré l’activation des lymphocytes B et la présence renforcée du virus dans les lésions glandulaires. / TEpstein-Barr virus (EBV), an ubiquitous human gammaherpesvirus affects 95% of adult human population and establishes a lifelong latency in memory B cells periodically entering into lytic replication with further propagation in oropharyngeal epithelia and shedding through saliva. Latent EBV infection is associated with lymphomas, carcinomas and autoimmune diseases. Although the conditions favoring the development of these pathologies are not completely understood, the immunosuppression and B cell activations play an important role in EBV-associated diseases.We examined the control over the EBV reservoir in a diseases associated with B cell activation. Two clinical situations associated with altered B cell activation were explored: primary Sjogren’s syndrome and subclinical mastitis in HIV-infected mothers.Primarily, we developed an in-house real-time PCR for EBV DNA quantification targeting the repetitive BamHI-W region of EBV DNA. The validation analyses enabled to evaluate the gain in sensitivity of the BamHI-W test relative to single repeat LMP2 qPCR. The impact of the variations in BamHI-W reiteration on EBV DNA quantification was further assessed on different EBV strains and clinical samples.In a second study, we showed that subclinical mastitis was common during breastfeeding, and it was an independent factor associated with increased EBV breast milk shedding. This secretion was associated with local inflammation and HIV shedding, reflecting synergy between the two viruses. We have also demonstrated that breast milk EBV DNA may be resistant to DNase, and the virus was probably encapsidated in the breast milk and thus potentially infectious.Finally, with an access to ASSESS cohort we looked for possible abnormal control over EBV infection in the blood compartment in primary Sjögren's syndrome, where salivary and lacrimal gland lesions were shown to be associated with the local activation of EBV. We have demonstrated that in primary Sjogren's syndrome EBV reservoir and replication in the systemic compartment are well controlled. The antibody response against EBV early antigen (EA) was not associated with increased DNA EBV.This thesis points out the link between the activation of B cells, chronic inflammation and control over the reservoir of EBV. In the mammary gland disturbed control of EBV infection is linked with subclinical mastitis. In contrast, in primary Sjogren’s syndrome EBV infection remains well controlled in the blood compartment despite the activation of B cells and the increased presence of the virus in glandular lesions.

Orientadores: Sandra Cecília Botelho Costa, Sandra Helena Alves Bonon / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T11:43:36Z (GMT). No. of bitstreams: 1 Peigo_MurilodeFreitas_M.pdf: 1466925 bytes, checksum: 094e2cd00645843fd5fa2c56ca66c2d5 (MD5) Previous issue date: 2012 / Resumo: O Lúpus Eritematoso Sistêmico (LES) é uma patologia sistêmica do tecido conjuntivo, que se apresenta de maneira variada na dependência do órgão afetado, da gravidade de seu acometimento e da idade do paciente, tendo influência de fatores raciais, de padrões imunológicos e ambientais. Pacientes lúpicos têm grande predisposição para desenvolver infecções graças à imunossupressão induzida pela própria doença como pelo uso de vários medicamentos em seu tratamento. Infecções causadas por herpesvírus, principalmente o Citomegalovírus Humano (CMV) e o Epstein-Barr (EBV), têm sido implicadas em várias doenças autoimunes graves, incluindo o LES. A reativação dos herpesvírus 6 e 7 (HHV-6 e HHV-7) geralmente ocorre em pacientes imunodeprimidos, mas seus papéis ainda são pouco estudados. As infecções por herpesvírus têm influência tanto no início do processo autoimune quanto na exacerbação da progressão da doença. A identificação de pacientes com alto risco de desenvolver doença pelos herpesvírus pode ser realizada utilizando técnicas de detecção de infecção ativa, como a Reação em Cadeia da Polimerase (Nested-PCR) e a detecção do antígeno pp65 do CMV (Antigenemia). Dependendo do caso, estes pacientes podem receber tratamento com antivirais. Diante do exposto, os objetivos deste estudo foram: monitorizar os pacientes com LES em relação à infecção ativa por CMV, EBV, HHV-6 e HHV-7, utilizando as técnicas de Nested-PCR e de antigenemia, bem como avaliar o impacto clínico dessas infecções. Foram incluídos neste trabalho, amostras de sangue de 71 pacientes em seguimento no Departamento de Reumatologia da Faculdade de Ciências Médicas ¿ UNICAMP, com diagnóstico de LES confirmado, sendo que 20/71 (28%) estavam com o lúpus ativo (SLEDAI ? 8) e 51/71 (72%) dos pacientes não tinham atividade lúpica (SLEDAI < 8). Das amostras de sangue pesquisadas, 10/71 (14%) foram positivas para os herpesvírus estudados, sendo que 90% destes pacientes com infecção ativa apresentavam o lúpus em atividade (p?0,006). Infecção ativa pelo CMV ocorreu em 4 pacientes (5,6%). HHV-7 foi detectado em 4 amostras (5,6%). Dois outros pacientes apresentaram dupla infecção por CMV e HHV-7 (2,8%). Infecção ativa pelo EBV e HHV-6 não foi detectada em nenhuma das amostras analisadas. Dois pacientes foram a óbito, sendo que um deles evoluiu com sepse de foco pulmonar (provável doença por CMV) e o outro com sepse por Psedomonas aeruginosa. Diante dos resultados obtidos, podemos observar que a infecção ativa pode ocorrer nos pacientes com LES, principalmente naqueles com a doença em atividade. Poucos estudos têm avaliado o impacto destas infecções no cuidado diário dos pacientes com LES. Acreditamos que este trabalho seja pioneiro e será de fundamental importância, contribuindo com este grupo de pacientes. Entretanto, futuros estudos deverão ser implementados com um número maior de pacientes e de coletas/paciente, principalmente naqueles com LES em atividade, que foram demonstrados com aqueles com fator de risco aumentado / Abstract: Systemic lupus erythematosus (SLE) is a connective tissue systemic pathology that presents itself in several ways, depending on the organ affected, the seriousness of the disease and patient¿s age, being influenced by racial factors, immunologic and environmental patterns. SLE patients have great predisposition to develop infections due to the immunosuppression induced by the disease itself and by the use of medicine in the treatment. Infections caused by herpesvirus, especially Human Cytomegalovirus (CMV) and Epstein-Barr (EBV), have been developed into several serious autoimmune diseases, including SLE. Herpesvirus 6 and 7 (HHV-6 and HHV-7) reactivation generally occurs in immunodepressed patients, but their roles are unclear. Herpesvirus infections have influence both on the beginning of the autoimmune process and on the aggravation of the disease progression. The patients that present high risks of developing herpesvirus related diseases can be identified using active infection detection techniques, such as the Nested polymerase chain reaction (Nested-PCR) and the CMV pp65 antigen detection (antigenemia). Depending on the case, the patients can receive treatment with antivirals. Face to the exposed, the objectives of this study were: to monitor the patients with SLE with regard to active infection by CMV using Nested-PCR and antigenemia techniques, and EBV, HHV-6, HHV-7 in serum, as well as to evaluate the clinic impact to these infections. There were included in this work blood samples of 71 patients that are being treated at the Department of Rheumatology, Faculty of Medical Sciences ¿ University of Campinas - UNICAMP, with a confirmed SLE diagnosis, given that 20/71 (28%) had active lupus (SLEDAI ? 8) and 51/71 (72%) of the patients didn¿t present lupic activity (SLEDAI < 8). Considering the blood samples researched, 10/71 (14%) were positive for the studied herpesvirus, and 90% of the patients with active infection presented lupus in activity (p ? 0,006). Active infection by CMV was observed in 4 patients (5,6%). HHV-7 was detected in 4 samples (5,6%). Two other patients presented double infection by CMV and HHV-7 (2,8%). Active infection by EBV and HHV-6 was not detected in any of the analyzed samples. Two patients have deceased, whose conditions developed into pulmonary sepsis (probable disease by CMV) and into Psedomonas aeruginosa sepsis, respectively. After analyzing the achieved results, we observe that active infection can appear in patients with SLE, especially in those with the disease in activity. Few studies have evaluated the impact of these infections on the daily care of patients with SLE. In this sense, we believe that this work is pioneer and that it will be of fundamental importance, contributing to this group of patients. However, future studies should be implemented, with a larger number of patients and samples, especially those with SLE in activity, which are the ones with increased risk factor as shown / Mestrado / Clinica Medica / Mestre em Clinica Medica

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.

Le virus Epstein-Barr (VEB) est un pathogène opportuniste qui a la capacité d’immortaliser les lymphocytes B et de provoquer une prolifération maligne, appelée syndrome lymphoprolifératif post-transplantation (SLP), chez les individus immunodéprimés. A l’intérieur de ce groupe, les personnes à plus haut risque sont les enfants, puisqu’ils sont à risque de développer une infection primaire par le VEB pendant leur régime d’immunosuppression post-greffe. Dans le but de développer un anticorps préventif, notre laboratoire s’est attardé au rôle du cycle lytique du VEB dans le développement du SLP. À cette fin, le premier objectif du présent projet vise à fournir la preuve expérimentale de l’existence ou non d’une phase réplicative productive pendant l’infection aiguë des lymphocytes B sanguins. Un examen des événements qui se déroulent au tout début de l’infection par le VEB tant au niveau de la réplication virale qu’au niveau de l’expression des gènes lytiques précoces et tardifs a révélé l’existence d’une phase réplicative productive pendant l’infection aiguë. Ceci a permis de justifier l’élaboration, dans notre laboratoire, d’un anticorps chimère (murin-humain) neutralisant, dirigé contre la protéine gp350 située sur l’enveloppe virale. Le deuxième objectif, quant à lui, vise à fournir la preuve expérimentale de la capacité neutralisante de cet anticorps chimère. Des essais de caractérisation in vitro ont démontré une capacité de reconnaissance de la protéine cible, notamment la gp350, et une capacité de neutralisation du virus par l’anticorps chimère. L’anticorps chimère anti-gp350 pourra faire l’objet d’essais précliniques in vivo en vue d’évaluer sa capacité à reconnaître le virus et à prévenir l’apparition de tumeurs de type SLP chez les souris SCID. Il pourrait être éventuellement utilisé, par la suite, comme traitement préemptif contre les tumeurs dans l’espoir de mieux gérer les patients à risque de développer un SLP. / Epstein-Barr virus (EBV) is an opportunistic pathogen in immunocompromised transplant patients. In these patients EBV infection can lead to malignant B-cell lymphoproliferation, called post-transplant lymphoproliferative disease (PTLD). This thesis project aimed to investigate the role of lytic EBV infection in the genesis of PTLD. The first experimental objective was to provide in vitro proof that EBV could induce productive replication upon acute in vitro infection of B cells. Data obtained through study of viral DNA replication and transcription during the first 96 hours post-infection indicate that lytic infection does occur. These results provided justification for proceeding to the second experimental objective which involved the characterization of an anti-gp350 human-mouse chimeric antibody for its capacity to recognize and neutralize EBV. Results showed that this antibody did possess neutralization activity. Further study of this anti-gp350 chimeric antibody in SCID mice is necessary in order to evaluate its in vivo efficacy against PTLD.

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

<p>Patients with rheumatoid arthritis (RA) are at increased risk of developing malignant lymphoma, although details about this association remain unclear. The aims of this thesis were to investigate risk factors for lymphoma in patients with RA and to characterize these lymphomas regarding subtype, presence of Epstein-Barr virus (EBV), clinical manifestations and prognosis. </p><p>The Swedish hospital discharge register and the cancer register were used to identify RA patients with lymphoma. Two case-control studies were performed, one smaller including RA patients with lymphoma hospitalised in Uppsala health care region 1964-1983 (n=41) and one larger study of hospitalised RA patients with lymphoma in Sweden 1964-1995 (n=378). RA patients from the same cohorts, but without lymphoma, were matched as controls. Medical records for cases and controls were scrutinized for exposure information. The lymphoma tissues were reclassified according to the WHO classification, and presence of EBV was analysed by EBER in situ hybridisation.</p><p>The most important risk factor for lymphoma development was high RA disease activity. No association was determined between treatment with traditional disease modifying drugs, non-steroidal anti-inflammatory drugs, aspirin, peroral and intra-articular corticosteroids and lymphoma risk. Diffuse large B-cell lymphoma (DLBCL) was more frequent in RA patients than in lymphoma patients in the general population and displayed stronger association with RA disease activity than other lymphoma subtypes. RA patients with DLBCL had increased extranodal involvement and more advanced lymphoma stage at presentation than DLBCL patients in general, and the prognosis was poor. </p><p>A further subdivision of DLBCL into germinal centre (GC) and non-GC subtypes by the expression patterns of CD10, bcl-6 and IRF-4 showed a predominance of the non-GC subtype. This suggested peripheral activated B-cells as the cells of origin in these lymphomas. </p><p>The presence of EBV was low in lymphomas in RA patients (12%). </p>