No description available.

No description available.

Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease. HTLV-1 Related Endogenous Sequence (HRES-1), a human endogenous retrovirus, produces 2 retroviral-like Gag capsid proteins (p8 and p15) that share significant sequence homology to the U1-subunit of the small ribonucleoprotein complex (U1sn-RNP), an autoantigen of lupus. The central hypothesis is that molecular mimicry between HRES-1 and U1sn-RNP serves as a priming event in SLE via the production of cross-reactive autoantibodies. Anti-HRES-1/U1sn-RNP serological responses in subjects with SLE and comparison populations were characterized. An overlapping peptide set mapping the HRES-1 p8 and p15 proteins was used. SLE subjects produce IgG to several regions of HRES-1. Healthy subjects or those with RA, HIV-1 infection, or HTLV-1-infection produced no significant anti-HRES-1 IgG. Anti-HRES-1 antibodies deposited in the kidneys of patients with SLE glomerulonephritis were identified. Our data suggests that HRES-1 plays a role in SLE by means of a molecular mimicry mechanism with U1sn-RNP.

Submitted by Pós Imunologia (ppgimicsufba@gmail.com) on 2017-02-20T18:12:18Z No. of bitstreams: 1 OLIVEIRA RC-2015.pdf: 1350637 bytes, checksum: b7f46beea8a9ab0be171a19ce556fa7f (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-06-14T13:28:00Z (GMT) No. of bitstreams: 1 OLIVEIRA RC-2015.pdf: 1350637 bytes, checksum: b7f46beea8a9ab0be171a19ce556fa7f (MD5) / Made available in DSpace on 2017-06-14T13:28:00Z (GMT). No. of bitstreams: 1 OLIVEIRA RC-2015.pdf: 1350637 bytes, checksum: b7f46beea8a9ab0be171a19ce556fa7f (MD5) / Fapesb / O lúpus eritematoso sistêmico (LES) é uma doença reumática autoimune que pode acometer uma em cada 1.700 mulheres brasileiras. Trata-se de doença cuja etiologia se fundamenta na associação da predisposição genética dos pacientes com fatores ambientais e hormonais, perda da tolerância imunológica e propagação da autorreatividade inata e adaptativa, resultando em manifestações clínicas complexas e multivariadas. Diversos aspectos associados com a atividade do LES, especialmente a doença renal presente em importante proporção dos pacientes, têm sido objeto de intensa investigação. Entre estes, a participação de autoanticorpos e a contribuição de componentes bioativos como citocinas e hormônios na nefrite lúpica ocupam posição de destaque. Objetivo: No presente estudo foi investigada a participação dos anticorpos anti-dsDNA totais e de alta avidez, antinucleossomo (ANuA) e hiperprolactinemia na atividade do LES e nas suas manifestações clínicas com destaque para Artropatia de Jaccoud, usando como população alvo mulheres lúpicas residentes na Bahia. Material e Métodos: Cento e quarenta e duas mulheres portadoras de LES foram investigadas para a prevalência e níveis de anticorpos anti-dsDNA totais, anticorpos anti-dsDNA de alta avidez e ANuA, além de hiperprolactinemia. Adicionalmente, foram testadas as correlações dos níveis destes componentes com a atividade da doença e suas associações com as manifestações clínicas mais prevalentes nestas pacientes. Autoanticorpos antinucleares foram determinados por testes de imunofluorescência indireta e ELISA. Níveis séricos de prolactina e citocinas foram determinados por imunoensaios de captura de antígeno, enquanto os níveis de C3 e C4 foram determinados por imunonefelometria. Os níveis de creatinina e proteinúria foram medidos por métodos colorimétricos e a atividade lúpica avaliada com o protocolo SLEDAI-2K. Testes de estatística univariada foram usados nas análises dos resultados. Resultados: Os níveis de anticorpos anti-dsDNA de alta avidez e de anti-dsDNA totais se correlacionaram diretamente com os níveis de anticorpos antinucleossomo, sendo esta correlação mais forte com os primeiros. Correlações significativas entre os níveis de C3, C4, VHS, proteinúria e SLEDAI foram observadas com os níveis de anticorpos anti-dsDNA de alta avidez e, exceto proteinúria, com os níveis de ANuA. Os níveis de anticorpos anti-dsDNA totais se correlacionaram apenas com os níveis de C3 e SLEDAI, porém de forma menos significativa que os anticorpos anti-dsDNA de alta avidez e ANuA. Pacientes com artropatia de Jaccoud apresentaram níveis mais altos de anticorpos antidsDNA totais e IL-6. Hiperprolactinemia leve a moderada foi encontrada em 19,7% das pacientes, observando-se níveis séricos de prolactina mais altos nas pacientes com comprometimento renal, além de existir correlação entre os níveis séricos deste hormônio com os níveis de creatinina sérica e proteinúria. Adicionalmente, existiu uma aparente supressão da produção de anticorpos anti-RNP- 70 em pacientes lúpicas hiperprolactinêmicas com fenômeno de Raynaud. Conclusões: Anticorpos anti-dsDNA constituem-se em importantes biomarcadores de doença ativa em pacientes portadoras de LES residentes na Bahia, podendo complementar o diagnóstico da artropatia de Jaccoud nestas pacientes, além de sugerir a presença de comprometimento renal quando são de alta avidez e detectados conjuntamente com proteinúria e baixos níveis de C3. Por outro lado, a presença de uma hiperprolactinemia leve a moderada pode ser verificada nestas mulheres, cujo envolvimento na doença renal lúpica foi demonstrado neste estudo, além de inibir a produção de anticorpos anti- RNP-70. / Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease that affect one in 1,700 Brazilian women. This disease is associated with a genetic predisposition of the patients and has the contribution of hormonal and environmental factors. Lupus' patients have a loss of immune tolerance, resulting in uncontrolled autoimmune reactivity and complex and multivariate clinical manifestations. Various aspects associated with the activity of SLE, especially kidney disease, have been the subject of intense investigation. Among these, the participation of autoantibodies and the contribution of bioactive components such as cytokines and hormones occupy a prominent position in these studies. Objective: The present study investigated in SLE women who lived in Bahia (Brazil), the participation of total and high avidity dsDNA, antinucleosome antibodies (ANuA) and hyperprolactinemia in the activity of this disease and its clinical manifestations, especially arthropathy of Jaccoud. Material and Methods: One hundred and forty-two women with SLE were investigated for the presence of hyperprolactinemia and prevalence and levels of total and high avidity anti-dsDNA antibodies and ANuA. Correlations among these components with biomarkers of lupus activity and their associations with the most prevalent clinical manifestations in the patients were also tested. Indirect fluorescent antibody test and ELISA determined antinuclear autoantibodies. Capture immunoassays measured prolactin and cytokine levels while C3 and C4 levels were determined by immunonephelometric tests. Creatinine levels and proteinuria were measured by colorimetric methods and lupus activity assessed with the SLEDAI-2K protocol. Descriptive statistical tests were used in the analyses of the results. Results: The levels of both high avidity and total anti-ds DNA antibodies correlated directly with the levels of antinucleosome antibodies, but this correlation was stronger with dsDNA antibodies of high avidity. Significant correlations among the levels of C3, C4, ESR, proteinuria and SLEDAI were observed with the levels of anti-dsDNA antibodies of high avidity and, except proteinuria, with ANuA levels. The levels of total anti-dsDNA antibodies correlated only with levels of C3 and SLEDAI, but these correlations were lesser than those of high avidity dsDNA antibodies and ANuA. Patients with Jaccoud arthropathy presented higher levels of dsDNA antibodies and IL-6, whereas mild to moderate hyperprolactinemia was found in 19.7% of the lupus patients. Higher serum levels of prolactin were demonstrated in patients with kidney disease, as well as there was a correlation between the levels of this hormone with their serum levels of creatinine and urine protein. In addition, hyperprolactinemia seems to inhibit the production of anti-RNP-70 autoantibodies. CONCLUSIONS: Antibodies to dsDNA are important biomarkers of active disease in SLE patients from Bahia and the increase in dsDNA antibody levels can complement the diagnosis of Jaccoud’s arthropathy. In addition, high avidity dsDNA autoantibodies are a good laboratory evidence of renal impairment in lupus patients when they are detected together with proteinuria and low levels of C3. On the other hand, the presence of a mild to moderate hyperprolactinaemia can be seen in lupus women whose involvement in lupus kidney disease and inhibition of the production of RNP-70 autoantibodies was demonstrated in this study.

No description available.

L'expression génique est régulée à de nombreuses étapes de la vie cellulaire. La synthèse des protéines ou traduction, étape ultime de cette expression, est finement régulée. Elle comporte trois phases: l'initiation, l'élongation et la terminaison. L'initiation commence par l'établissement de la sous-unité ribosomique 40S sur cet ARNm qu'elle balaye ensuite jusqu'au codon initiation. Pour cela, des facteurs canoniques sont impliqués. Parmi eux, le facteur eIF3 interagit directement avec celle-ci. Au cours de mes travaux, j'ai étudié dans une première partie l'interaction putative entre le facteur eIF3 et la petite sous-unité ribosomique 40S. Le ribosome est constitué par deux types d'entités : des protéines ribosomiques et l'ARNr. Le facteur eIF3, contient au moins 13 sous-unités, dont deux possèdent un RRM, et sont potentiellement capables de lier cet ARNr via leur RRM: p44 et p116. eIF3p44 a montré auparavant qu'elle pouvait lier l'ARNr 18S. J'ai effectué un criblage d'une banque de fragments de cet ARNr pour identifier un site de liaison de p44 sur la sous-unité 40S. Les ARNm néo-synthétisés sont transportés et localisés afin de permettre l'expression des protéines au moment opportun et en un lieu précis de la cellule. Dans une deuxième partie, j'ai étudié des interactions impliquées dans le contrôle de l'initiation de la traduction d'un ARNm localisé chez la levure S. cerevisiae pendant son transport : l'ARNm ASH1. Il est régulé par Khd1p, protéine à trois domaines KH, qui lie directement un de ses éléments de localisation. Cette interaction est abolie par la phosphorylation de Khd1p lorsque l'ARNm est correctement localisé.

La biogenèse des ribosomes est un processus complexe qui implique la production et l'assemblage de 4 ARN et d'environ 80 protéines. Chez l'Homme, la production des deux sous-unités ribosomiques débute dans le nucléole par la synthèse par l'ARN polymérase I d'un long transcrit contenant les séquences des ARN ribosomiques 5.8S, 18S et 25S, qui s'associe de manière co-transcriptionnelle à des protéines ribosomiques et à des facteurs d'assemblage. Le quatrième ARN ribosomique, l'ARNr 5S est transcrit séparément par l'ARN polymérase III, et s'associe avec les protéines ribosomiques Rpl5 et Rpl11 en dehors du ribosome. Ce sous-complexe, appelé particule 5S, est ensuite intégré au sein de la grande sous-unité. La particule 5S est également impliquée dans le contrôle de la prolifération cellulaire. En effet, en cas de dé-régulation de la biogenèse du ribosome, la particule 5S s'accumule dans le nucléoplasme et interagit directement avec l'ubiquitine-ligase MDM2, provoquant la stabilisation du suppresseur de tumeur p53. L'objectif principal de ma thèse est d'étudier le rôle des facteurs d'assemblage Rpf2 et Rrs1 dans la biogenèse du ribosome. Ces protéines assurent deux fonctions distinctes : elles sont requises pour l'association de la particule 5S avec la sous-unité pré-60S, et stimulent la transcription des ARNr par l'ARN polymérase I. Elles sont donc impliquées dans deux événements fondamentaux qui conditionnent les capacités de prolifération cellulaire. La combinaison d'études structurales par cristallographie aux rayons X, et d'études d'interactions protéine-ARN in vitro et in vivo, m'ont permis de mieux appréhender le rôle du complexe Rpf2/Rrs1 dans l'intégration de la particule 5S et dans la maturation de la grande sous-unité. J'ai également étudié le rôle du complexe Rpf2/Rrs1 dans la régulation de la transcription des ARNr, en caractérisant ses interactions avec la polymérase I. / Ribosome Biogenesis is a complex process that requires the production and the correct assembly of the 4 rRNA with more than 80 proteins. Ribosome biogenesis starts by the transcription of a pre-RNA precursor in the nucleolus. Three of the four ribosomal RNAs, the 5.8S, 18S, and 25S rRNAs, are cotranscribed as a single 35S precursor by polymerase I. This precursor is cotranscriptionally modified, folded, cleaved, and assembled with both ribosomal proteins and non-ribosomal factors to generate the mature ribosomes. The fourth rRNA, the 5S rRNA, is transcribed by RNA polymerase III and is assembled into the 5S particle, containing ribosomal proteins Rpl5 and Rpl11, prior to its incorporation into preribosomes. In mammals, the 5S RNP is also a central regulator of the homeostasis of the tumor suppressor p53 The main objective of my thesis was to understand the precise roles of the two assembly factors Rpf2 and Rrs1 in ribosome biogenesis. These proteins have two distinctive functions : Rpf2 and Rrs1 are required for the 5S particle incorporation into the large subunit, and stimulate the rRNA transciption by polymerase I. Using a combination of structural studies by X-Ray crystallography and biochemical approaches as in vitro and in vivo methods to study proteins-RNA interactions, I was able to uncover the function of the Rpf2/Rrs1 dimer in the maturation of the large subunit through the recruitment of the 5S particle. I also studied the function of Rpf2 and Rrs1 in the rRNA transcription regulation, by characterizing physical connection with polymerase I subunits.

<p>Patients with systemic lupus erythematosus (SLE) have elevated levels of interferon (IFN)-α in blood and IFN-α-producing cells in tissues. In the present thesis, we investigate the mechanisms behind the upregulated IFN-α-production in SLE and also show that the IFN-α system is activated in primary Sjögren’s syndrome (pSS), with IFN-α-producing cells in the major affected organ, the salivary glands. The IFN-α is a type I IFN, a family of cytokines counteracting especially viral infections, by acting directly on infected cells, and via many immunomodulatory effects. The latter may also contribute to autoimmune processes.</p><p>The type I IFNs are usually produced upon recognition of microbial structures. In SLE, however, DNA-containing immune complexes (ICs) that induce IFN-α production are found. Many autoantibodies in SLE and pSS are directed to nucleic acids or to DNA/RNA-binding proteins. We show that also RNA in complex with autoantibodies from SLE or pSS patients (RNA-IC) induces IFN-α-production. The RNA could be either in the form of RNA-containing material released from apoptotic or necrotic cells or as a pure RNA-containing autoantigen, the U1 small nuclear ribonucleoprotein particle. </p><p>The IFN-α-production induced by RNA-IC occurred in plasmacytoid dendritic cells (PDCs), also termed natural IFN-producing cells (NIPCs), via binding to Fcγ-receptor IIa, endocytosis and triggering of Toll-like receptors (TLRs), probably TLR7 and TLR9. The RNA-IC may also have other effects, and we found that they induce prostaglandin E2 (PGE2) production in monocytes and tumor necrosis factor (TNF)-α in both monocytes and NIPC/PDC. The PGE2 downregulated the IFN-α induction in NIPC/PDC, and the IFN-α induction was increased in monocyte-depleted cell cultures. </p><p>The findings presented in this thesis aids in the understanding of the mechanisms behind the activated IFN-α system in SLE and other autoimmune diseases, and shows that also pSS is one of these diseases.</p>

Patients with systemic lupus erythematosus (SLE) have elevated levels of interferon (IFN)-α in blood and IFN-α-producing cells in tissues. In the present thesis, we investigate the mechanisms behind the upregulated IFN-α-production in SLE and also show that the IFN-α system is activated in primary Sjögren’s syndrome (pSS), with IFN-α-producing cells in the major affected organ, the salivary glands. The IFN-α is a type I IFN, a family of cytokines counteracting especially viral infections, by acting directly on infected cells, and via many immunomodulatory effects. The latter may also contribute to autoimmune processes. The type I IFNs are usually produced upon recognition of microbial structures. In SLE, however, DNA-containing immune complexes (ICs) that induce IFN-α production are found. Many autoantibodies in SLE and pSS are directed to nucleic acids or to DNA/RNA-binding proteins. We show that also RNA in complex with autoantibodies from SLE or pSS patients (RNA-IC) induces IFN-α-production. The RNA could be either in the form of RNA-containing material released from apoptotic or necrotic cells or as a pure RNA-containing autoantigen, the U1 small nuclear ribonucleoprotein particle. The IFN-α-production induced by RNA-IC occurred in plasmacytoid dendritic cells (PDCs), also termed natural IFN-producing cells (NIPCs), via binding to Fcγ-receptor IIa, endocytosis and triggering of Toll-like receptors (TLRs), probably TLR7 and TLR9. The RNA-IC may also have other effects, and we found that they induce prostaglandin E2 (PGE2) production in monocytes and tumor necrosis factor (TNF)-α in both monocytes and NIPC/PDC. The PGE2 downregulated the IFN-α induction in NIPC/PDC, and the IFN-α induction was increased in monocyte-depleted cell cultures. The findings presented in this thesis aids in the understanding of the mechanisms behind the activated IFN-α system in SLE and other autoimmune diseases, and shows that also pSS is one of these diseases.

The thesis focuses on issues of the procedures in the terminal manoeuvring area (TMA) at regional airports. The goal is to provide a complex study of possible implementation of instrumental arrivals, departures and approaches on the basis of the requirements of the Performance Based Navigation (PBN) at a particular regional airport in the Czech Republic (Kunovice airport). The simulative evaluation of the operational impacts caused by the suggested changes in TMA Brno and CTR Kunovice is also a part of the thesis. The last section is focused on providing a generic methodology describing the process of design and evaluation of PBN procedures.