Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-27T18:12:44Z No. of bitstreams: 1 alyriateixeiradias.pdf: 10088679 bytes, checksum: 54e2cba2e92e9707b5c8813c456ca1cb (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-28T12:50:27Z (GMT) No. of bitstreams: 1 alyriateixeiradias.pdf: 10088679 bytes, checksum: 54e2cba2e92e9707b5c8813c456ca1cb (MD5) / Made available in DSpace on 2016-06-28T12:50:27Z (GMT). No. of bitstreams: 1 alyriateixeiradias.pdf: 10088679 bytes, checksum: 54e2cba2e92e9707b5c8813c456ca1cb (MD5) Previous issue date: 2012-03-01 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A esclerose múltipla (EM) é uma doença autoimune que acomete o sistema nervoso central (SNC) promovendo inflamação, desmielinização e subsequente comprometimento neurológico. A encefalomielite autoimune experimental (EAE) é o modelo animal mais amplamente utilizado para o estudo da EM, podendo ser induzida por uma grande diversidade de protocolos. Porém, o resultado da doença pode ser diferente em cada modelo, dependendo das características genéticas dos animais utilizados, da fonte e concentração do material antigênico e do modo de aplicação do antígeno, refletindo, em parte, a heterogeneidade encontrada nas diversas formas clínicas da EM. Portanto, devido à diversidade de modelos de indução de EAE, vários fatores relacionados à resposta imunológica, permanecem pouco conhecidos. O presente trabalho buscou avaliar a diferença entre duas concentrações antigênicas, utilizadas na indução, sobre o desenvolvimento clínico da EAE e em diversos parâmetros da resposta imunológica. Para isto, a EAE foi induzida em camundongos da linhagem C57BL/6, utilizando-se a glicoproteína mielínica de oligodendrócitos (MOG35-55), em duas concentrações diferentes (100 ou 300 μg do peptídeo MOG35-55) e mantendo-se as concentrações de Mycobacterium tuberculosis (4 mg/mL) e toxina pertussis (300 ng) constantes. Foi então acompanhado o curso clínico da doença, nos dois protocolos utilizados, durante um período de 58 dias. Além disso, parâmetros da resposta imunológica, como avaliação do infiltrado celular no cérebro e dosagem de citocinas e quimiocinas no SNC e linfonodos inguinais foram acompanhados no 7°, 10°, 14°, 21° e 58° dias após a indução. Observou-se que embora não tenha ocorrido diferença significativa entre os grupos de animais imunizados em relação à pontuação do escore clínico, ocorreram diferenças importantes entre estes dois protocolos no que diz respeito ao perfil de citocinas, quimiocinas e infiltrado celular no cérebro. O aumento das citocinas pró-inflamatórias e quimiocinas no SNC ocorreu de forma precoce no grupo imunizado com 100 μg do peptídeo MOG35-55, que também exibiu infiltrado celular precoce e mais intenso do que o grupo imunizado com 300 μg do peptídeo MOG35- 55. Além disso, o nível das quimiocinas CCL5 e CCL20 e das citocinas de perfil Th1 e Th17 foram, de forma geral, mais elevados no grupo imunizado com 100 μg do peptídeo MOG35-55. Os resultados sugerem que somente a variação na concentração antigênica do MOG35-55, no momento da indução, não é capaz de induzir diferentes cursos clínicos de EAE e que a concentração mais elevada do antígeno (300 μg do peptídeo MOG35-55) parece promover algum mecanismo regulador ou de tolerância, que deve ser melhor estudado. / Multiple sclerosis (MS) is an inflammatory autoimmune disease of central nervous system (CNS) that causes demyelination and neurological deficit. The experimental autoimmune encephalomyelitis (EAE) is the most common model for study this disease. The EAE can be induced by different protocols and the score of the disease is related to the genetic background of the animals, the concentration of antigen and the way of induction, reproducing the heterogeneity of the MS. Thus, due to the diversity of EAE induction, different factors related to immune response are still unclear. The aim of this study was evaluate the difference between two antigen concentrations in the development of EAE and the parameters of immune response. The EAE was induced in C57BL/6 female mice with the myelin oligodendrocyte glycoprotein (MOG35-55) in two different concentrations (100 or 300μg of MOG35-55), but keeping the same concentrations of Mycobacterium tuberculosis (4 mg/mL) and pertussis toxin (300 ng). The disease clinical signs were followed until the 58th day after induction in both protocols, and the immunological parameters, such as cellular infiltrate at brain and levels of cytokines and chemokines at CNS and lymph nodes, were evaluated at 7th, 10th, 14th, 21st and 58th days post induction. In relation to the clinical score, were not observed significant differences between the different protocols, however the cytokines, chemokines and cellular infiltrate profile at brain showed interesting results. The release of Th1 and Th17 cytokines and the CCL5 and CCL20 chemokines at CNS occurred early and more intense at 100μg MOG35-55 group, in accordance with the earlier and intense cellular infiltrate than 300μg MOG35- 55 group. In conclusion, the results suggest that only the differences in the MOG35-55 concentration at induction, is not capable of induce different clinical signs of EAE and that the 300 μg of MOG35-55 seems to promote a regulatory or tolerance mechanism that deserves further studies.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-20T18:17:08Z No. of bitstreams: 1 adrianakarlagaviosilva.pdf: 1087827 bytes, checksum: c5a343cea0fe929422a92846e99a422c (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:24:59Z (GMT) No. of bitstreams: 1 adrianakarlagaviosilva.pdf: 1087827 bytes, checksum: c5a343cea0fe929422a92846e99a422c (MD5) / Made available in DSpace on 2016-09-26T20:24:59Z (GMT). No. of bitstreams: 1 adrianakarlagaviosilva.pdf: 1087827 bytes, checksum: c5a343cea0fe929422a92846e99a422c (MD5) Previous issue date: 2010-03-26 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A Esclerose Múltipla (EM) é uma doença inflamatória, crônica e desmielinizante do sistema nervoso central (SNC). Embora ela seja, ainda, de etiologia desconhecida, é considerada uma doença auto-imune mediada por linfócitos T “helper” 1 (Th1) e T “helper” 17 (Th17) e com predominância em mulheres. Contudo, as bases para esta predominância ainda não estão bem elucidadas. Os primeiros sintomas da EM, normalmente, surgem após a maturidade sexual. Por outro lado, níveis elevados de hormônios sexuais durante o período de gravidez parecem reduzir os sinais e sintomas, os quais aumentam no período pós-parto. A Encefalomielite auto-imune experimental (EAE) é o modelo animal mais usado para estudar a EM. Assim, este estudo teve como objetivo avaliar os efeitos do tratamento com 17 β-Estradiol na prevenção da EAE murina. Os resultados indicaram que o tratamento com este hormônio melhorou o curso clínico da doença, diminuiu a concentração de citocinas pró-inflamatórias, como interferon-gama (IFN-γ), fator de necrose tumoral-alfa (TNF-α) e interleucina 17 (IL-17), e a infiltração de leucócitos no SNC, além de aumentar os níveis da interleucina 10 (IL-10). Houve, também, um aumento de linfócitos B no cérebro e baço dos animais submetidos ao tratamento. Portanto, o 17 β-Estradiol parece desempenhar um papel imunomodulador na EAE. / Multiple Sclerosis (ME) is an inflammatory, chronic and demyelinating disease of the central nervous system (CNS). Although the etiology of it is still unclear, it is considered a CD4+ T Helper-1-mediated and CD4+ T Helper-17-mediated autoimmune disease and the highest prevalence of it is in women. However, the basis for this prevalence isn´t still well clear. The first symptoms of ME, often, appear after sexual maturity. On the other hand, high levels of sexual hormones during pregnancy seems to low signs and symptoms, which to be high after childbirth. Experimental autoimmune encephalomyelitis (EAE) is an animal model to study ME. Therefore, the aim of this study was to investigate the effects of treatment with 17 β-Estradiol on murine EAE. Results indicated that the treatment with this hormone ameliorated the clinical course of the disease, decreased pró-inflammatory cytokines levels, like interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α) e interleucine 17 (IL-17), and infiltration of white blood cells on CNS, further on increased interleucine 10 (IL-10) levels. There was also an increased of B cells in brain and spleen of treated animals. In conclusion, 17 β-Estradiol may play an immunomodulatory role in EAE.

Le système nerveux central est un site particulier vis-à-vis du système immunitaire, en raison de la présence de la barrière hémato-encéphalique et de la barrière sang-liquide céphalorachidien. Les plexus choroïdes ont été considérés comme une voie d’entrée de certains lymphocytes dans le système nerveux central. Et le liquide céphalo-rachidien a été considéré comme une voie préférentielle de circulation des cellules immune au cours de la surveillance neuro-immunitaire de l’ensemble des compartiments cérébraux, puisque le LCR circule des ventricules, aux espaces sous-arachnoïdiens ainsi qu’aux velum et citernes internes. L’implication du système plexus choroïdes-liquide céphalorachidien dans l’infiltration cellulaire et la distribution des différents effecteurs immuns a été évaluée. Premièrement, nous avons analysé la relation entre le LCR et la répartition des différentes cellules immune au sein du système nerveux central, dans deux modèles d’encéphalite autoimmune expérimentale, utilisé comme modèle de la sclérose en plaque. Deuxièmement, nous avons recherché les partenaires moléculaires pouvant être impliqués dans la mise en place d’une inflammation, tels que les molécules d’adhésion exprimés par l’épithélium choroïdien, et les chimiokines pouvant être sécrétées dans le liquide céphalorachidien. Nos résultats identifient les plexus choroïdes comme une source de chimiokines sécrétées dans le liquide céphalorachidien, ce dernier orchestrant la distribution des différents effecteurs immunitaire au cours de l’inflammation / The central nervous system is an immunologically specialized site, because of the blood-brain barrier and the blood-cerebrospinal fluid barrier. The choroid plexuses had been considered as a preferential site for the entry of lymphocytes into the CNS. And the cerebrospinal fluid has been considered as a preferential pathway of circulation for immune cells during physiological neuroimmune surveillance, in all cerebral compartments, as the cerebrospinal fluid circulates from the ventricles to the subarachnoid spaces as well as the velum and internal cisterns. We evaluate the involvement of the choroid plexus-cerebrospinal fluid system in the cerebral infiltration and distribution of immune cells in CNS inflammation. First we realized a time course analysis of the different type of immune cell association with the CSF-containing compartments in two experimental autoimmune encephalomyelitis, models of multiple sclerosis. Secondly, we analyzed the molecular partners that could be involved in CNS inflammation development, such as adhesion molecules expressed on the choroid plexus, and chemokines secreted into the cerebrospinal fluid. Results identified the choroid plexuses as a source of chemokines, released into the cerebrospinal fluid that orchestrates the immune cell invasion during CNS inflammation

Experimental autoimmune encephalomyelitis (EAE) is the rodent model of multiple sclerosis (MS), a chronic autoimmune neuroinflammatory disease that has a devastating impact on various neurological functions of the patients. The hallmarks of both, MS and EAE, are neuroinflammation, demyelination and neuroaxonal degeneration. Various types of lymphoid and myeloid cells were shown to infiltrate the central nervous system and to participate in disease pathology. However, the role of eosinophil granulocytes has been less explored thus far. An early study showed that eosinophils infiltrate into the spinal cord of EAE mice and suggested their role in the disease progression. Recently, it was reported that eosinophils can play a protective role against EAE when mice are treated with an extract from helminths. Furthermore, it was shown that EAE development is not altered in mice deficient for interleukin-5, an important eosinophil pro-survival factor. Taken together, the role of eosinophils in EAE is currently unclear and needs to be investigated in detail. In the present study, we use the active model of EAE, whereby we immunized the C57BL/6 mouse strain with MOG35-55 peptide emulsified in the complete Freund’s adjuvant, in order to study a possible contribution of eosinophils to the disease pathology. Using the flow cytometry and RT-qPCR analysis of the spinal cord, we show that eosinophils infiltrate into the tissue in the course of EAE. The infiltration is likely driven by eosinophil chemoattractants, such as eotaxin-1, as the concentration of the latter was increased in the spinal cord during EAE, as shown on mRNA and protein level. Moreover, detailed flow cytometry analysis of spinal cord eosinophils revealed that they show signs of activation, namely an increase in CD11b and decrease in CCR-3 surface expression. Furthermore, we observed signs of degranulation of spinal cord eosinophils in EAE which was measured as a decrease of the side scatter parameter and an upregulation of CD63 surface expression. These data suggest a potential role of eosinophils in the pathology of EAE. In order to elucidate whether eosinophils are important for the disease development, eosinophil-deficient mice were subjected to EAE and the clinical development of the disease was observed. For this purpose, we used two independent models of eosinophil deficiency - ΔdblGATA1 and interleukin-5-depleted mice. ΔdblGATA1 mice are a genetically manipulated mouse strain bearing a deletion in GATA1 promoter that causes a specific depletion of eosinophils. Interestingly, clinical development of EAE was not affected in these mice when compared to their wild-type controls. As a next step, we depleted eosinophils by injecting wild-type mice with an antibody against the eosinophil pro-survival factor interleukin-5 in order to reduce eosinophil numbers in the effector phase of EAE. In accordance with the result from the experiment with ΔdblGATA1 mice, EAE progression was not altered in the eosinophil-depleted mice when compared to mice that were injected with an isotype control antibody. Further, we analyzed the neuroinflammation and demyelination in the spinal cord of 4ΔdblGATA1 mice subjected to EAE. Specifically, the infiltration of inflammatory cell populations, including CD4 and CD8 T cells, neutrophils and macrophages, was assessed by flow cytometry. In agreement with the unchanged clinical EAE development, inflammatory cell infiltration was not affected in ΔdblGATA1 mice. Furthermore, we analyzed expression of pro-inflammatory cytokines in the spinal cord of ΔdblGATA1 mice subjected to EAE in order to better characterize the inflammatory status. No significant changes were detected further confirming that eosinophils do not contribute to neuroinflammation in EAE. Finally, we assessed the demyelination in the spinal cord of ΔdblGATA1 EAE mice using luxol fast blue staining to detect myelin. In accordance with the unaffected clinical development and inflammatory status, we did not observe any difference in the spinal cord demyelination in ΔdblGATA1 mice when compared to their wild-type littermates. Taken together, although eosinophils infiltrate into the spinal cord of EAE mice and are activated and degranulate therein, they are dispensable for EAE development.

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The triggers for the development of multiple sclerosis (MS) have not been fully understood to date. One hypothesis proposes a viral etiology. Interestingly, viral proteins from human endogenous retroviruses (HERVs) may play a role in the pathogenesis of MS. Allelic variants of the HERV-K18 env gene represent a genetic risk factor for MS, and the envelope protein is considered to be an Epstein–Barr virus-trans-activated superantigen. To further specify a possible role for HERV-K18 in MS, the present study examined the immunogenicity of the purified surface unit (SU). HERV-K18(SU) induced envelope-specific plasma IgG in immunized mice and triggered proliferation of T cells isolated from these mice. It did not trigger phenotypic changes in a mouse model of experimental autoimmune encephalomyelitis. Further studies are needed to investigate the underlying mechanisms of HERV-K18 interaction with immune system regulators in more detail.

No description available.

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No description available.