HCV is remarkable at disrupting human immunity to establish chronic infection. The accumulation of Treg cells at the site of infection and upregulation of inhibitory signaling pathways (such as T-cell Ig and mucin domain protein-3 (Tim-3) and galectin-9 (Gal-9)) play pivotal roles in suppressing antiviral effector T (Teff) cells that are essential for viral clearance. While Tim-3/Gal-9 interactions have been shown to negatively regulate Teff cells, their role in regulating Treg cells is poorly understood. To explore how Tim-3/Gal-9 interactions regulate HCV-mediated Treg-cell development, here we provide pilot data showing that HCV-infected human hepatocytes express higher levels of Gal-9 and TGF-β, and upregulate Tim-3 expression and regulatory cytokines TGF-β/IL-10 in co-cultured human CD4+ T cells, driving conventional CD4+ T cells into CD25+Foxp3+ Treg cells. Additionally, recombinant Gal-9 protein can transform TCR-activated CD4+ T cells into Foxp3+ Treg cells in a dose-dependent manner. Importantly, blocking Tim-3/Gal-9 ligations abrogates HCV-mediated Treg-cell induction by HCV-infected hepatocytes, suggesting that Tim-3/Gal-9 interactions may regulate human Foxp3+ Treg-cell development and function during HCV infection.

HCV is remarkable at disrupting human immunity to establish chronic infection. The accumulation of Treg cells at the site of infection and upregulation of inhibitory signaling pathways (such as T-cell Ig and mucin domain protein-3 (Tim-3) and galectin-9 (Gal-9)) play pivotal roles in suppressing antiviral effector T (Teff) cells that are essential for viral clearance. While Tim-3/Gal-9 interactions have been shown to negatively regulate Teff cells, their role in regulating Treg cells is poorly understood. To explore how Tim-3/Gal-9 interactions regulate HCV-mediated Treg-cell development, here we provide pilot data showing that HCV-infected human hepatocytes express higher levels of Gal-9 and TGF-β, and upregulate Tim-3 expression and regulatory cytokines TGF-β/IL-10 in co-cultured human CD4+ T cells, driving conventional CD4+ T cells into CD25+Foxp3+ Treg cells. Additionally, recombinant Gal-9 protein can transform TCR-activated CD4+ T cells into Foxp3+ Treg cells in a dose-dependent manner. Importantly, blocking Tim-3/Gal-9 ligations abrogates HCV-mediated Treg-cell induction by HCV-infected hepatocytes, suggesting that Tim-3/Gal-9 interactions may regulate human Foxp3+ Treg-cell development and function during HCV infection.

Tim-3 has been linked to several inflammatory diseases by regulation on both adaptive and innate immunities. Here, we assessed the augmented expression of Tim-3 in brain tissue of ischemia-reperfusion mice and PBMCs of ischemic stroke (IS) patients. The augmented expression of Tim-3 significantly correlated with abnormal lipid levels. In vitro studies showed that plasma from ischemic stroke patients induced Tim-3 expression in THP- 1 cells. More importantly, our results revealed a significant correlation of Tim-3 expression on CD4 + T cells with systemic IL-17 in patients with ischemic stroke. Consistently, we also found a positive correlation of Tim-3 expression on CD14 + monocytes and serum TNF-a in IS patients. Collectively, augmented expression of Tim-3 may play an important role in the pathogenesis of ischemic stroke by regulation of proinflammatory cytokines. Further studies will give us new insights on the pathogenesis of ischemic stroke and potentially provide a new target at the medical therapy.

Purpose. The present work hypothesized that proteolytic dissolution of intervertebral discs could induce biomechanical change comparable to the change observed in natural disc degeneration. A method to do such could be utilized for in vitro research where intersample differences in geometry and chemical makeup render it difficult to compare and aggregate results into generalized conclusions. Methods. Forty-one bovine coccygeal intervertebral discs were isolated with individual functional spinal units. Samples were loaded in three modes: compression/tension, flexion/extension, and axial rotation. The anulus fibrosus of each disc was injected with 200µl trypsin or fetal bovine serum (control) and incubated for an allotted period: 30 minute, 60 minutes, or 180 minutes. Mechanical loading was repeated and the load-displacement responses before and after treatment were compared as were the differences between each time group. Results. Significant change was observed in the discs' total range (stiffness), low range (laxity), and hysteresis. Changes in load-displacement response were observed to be correlated with both treatment and time. Conclusions. Enzymatic degeneration of intervertebral discs shows promise as a means to further understanding of disc mechanics in varying levels of degeneration. In virtually all cases, the trypsinized discs exhibited the increased joint laxity and decreased stiffness that is associated with early stage, natural disc degeneration.

Les œuvres de l'écrivain française Lydie Salvayre et des cinéastes américains Tim Burton et Terry Gilliam présentent une même dénonciation de la société du simulacre à travers une esthétique grotesque. Ils contestent dans leurs œuvres la pratique de la novlangue, celle du politiquement correct et le mélange de la réalité avec la fiction. Le fonctionnement dialectique du grotesque et sa capacité à procurer un vertige étonnant lui permet de rendre visible ces contradictions. La modification de l'imaginaire par la société de consommation et du simulacre les préoccupent particulièrement, car les auteurs observent que la transformation des signes en simples signifiants, dont le postmodernisme illustre le fonctionnement, conduisent l'individu à avoir un rapport déformé à la réalité, à la conscience historique et au symbole. Le grotesque est cette esthétique qui leur permet de former des mélanges dans leurs œuvres en préservant l'identité des signifiés et de restaurer ainsi un rapport à l'Histoire et au symbole. Le grotesque est cette esthétique qui permet le mélange sans équivalence, car elle donne à voir les contraires et leur confère du sens. Les auteurs lient leurs œuvres grotesques au mythe, cette fiction particulière qui permet d'avoir un rapport instinctif à la connaissance par le biais d'images particulièrement fortes. Le grotesque, dans sa dimension anthropologique et ontologique, réhabilite en définitive des fictions qui échappent aux problématiques du simulacre. / The works of Lydie Salvayre, American movie directors Tim Burton and Terry Gilliam present a similar criticism of a society of simulacrum, by their use of the aesthetically grotesque. In their work, they question the use of newspeak, of the politically correct, and the mixing of reality and fiction. The dialectical working of the grotesque and its ability to produce an astonishing sense of vertigo enables it to bring out these contradictions. They are particularly concerned by the extent to which a society of consumption and simulacrum has modified the imaginary. These autors have observed that the transformation of signs into mere signifiers, something the workings of which are demonstrated in postmodernism, leads the individual to have a distorted relationship with reality, historical awareness and the symbol. The grotesque is that aesthetic form which allows them to make mixes in their work whilst preserving the meaning of the signified and which thereby allows them to restore a relationship to history and the symbol. The grotesque is that esthetic form which allows them to make mixes with no equivalent, since it shows opposites whilst conferring sense on them. The autors link their grotesque works to myth, that kind of fiction which enables us to have a instinctive relationship to knowledge by the means of particularly strong images. When all is said and done, the grotesque, in its anthropological and ontological dimension, reinstates a fiction which avoids the problems of simulacrum.

Made available in DSpace on 2016-03-15T19:45:39Z (GMT). No. of bitstreams: 1 Julia de Carvalho Almeida Oliveira.pdf: 1471970 bytes, checksum: 7c2fd2ccef5deb9f9389258efcdffdb9 (MD5) Previous issue date: 2012-08-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabajo tiene como objetivo presentar, a la luz de la concepción bakhtiniana del lenguaje, el diálogo intersemiótico entre la novela del portugués José Saramago, As Intermitencias da morte (2005), y la animación producida por Tim Burton, A Noiva cadáver (2005). En él se examinarán, por medio de los estudios comparativos, La muerte carnavalizada en ambos textos con el fin de identificar cómo se produce El proceso de carnavalización. Así, el estudio no se detiene en la similitud temática de las obras, sino también en la postura ideológica de sus autores y la visión del mundo que se puede ver en los relatos de ficción. El trabajo propone un ejercicio analítico entre los sistemas de signos diferentes, en que será posible conocer lãs particularidades de cada texto artístico y sus modos de producción. Para ello, se utilizará como referencial bibliográfico, así como el principio dialógico bakhtiniano, los estudios, sobre todo, de Mikhail Bakhtin, sobre los conceptos de carnavalización y grotesco. / O presente trabalho visa a apresentar, à luz da concepção bakhtiniana de linguagem, o diálogo intersemiótico entre o romance do português José Saramago, As Intermitências da morte (2005), e a animação produzida por Tim Burton, A Noiva cadáver (2005). Examinar-se-á, por meio dos estudos comparados, a morte carnavalizada em ambos os textos, a fim de identificar como ocorre o processo de carnavalização. Desse modo, o estudo não se deterá apenas à semelhança temática das obras, mas, também, no posicionamento ideológico de seus autores e na visão de mundo que pode ser observada nas narrativas ficcionais. O trabalho propõe um exercício de análise entre diferentes sistemas sígnicos, em que será possível conhecer as especificidades de cada texto artístico, além de seus modos de produção. Para tanto, serão utilizados como referencial bibliográfico, além do princípio dialógico bakhtiniano, os estudos, sobretudo, de Mikhail Bakhtin acerca dos conceitos de carnavalização e grotesco.

Ebola virus (EBOV) is a member of the Filoviridae family of highly pathogenic viruses that cause severe hemorrhagic fever and is the causative agent of the 2014 West Africa outbreak. Currently, there are no approved filovirus vaccines or treatments to combat these sporadic and deadly epidemics. One target for EBOV antiviral therapy is to block viral entry into host cells. Recently, phosphatidylserine (PtdSer) receptors, primarily known for their involvement in the clearance of dying cells, were shown to mediate entry of enveloped viruses including filoviruses. The PtdSer receptors, T-cell immunoglobulin mucin domain-1 (TIM-1) and family member TIM-4, serve as filovirus receptors, significantly enhancing EBOV entry. TIM-dependent virus uptake occurs via apoptotic mimicry by binding to PtdSer on the surface of virions through a conserved PtdSer binding pocket within the amino terminal IgV domain. TIM-4 is expressed on antigen presenting cells (APCs), including macrophages and dendritic cells (DCs), which are critical in early EBOV infection. My studies are the first to define the molecular details of virion/TIM-4 interactions and establish the importance of TIM-4 for EBOV infection of murine resident peritoneal macrophages. In addition, previous work has utilized only in vitro models to establish the importance of the TIM proteins in EBOV entry. My studies are the first to demonstrate the importance of TIM-1 and TIM-4 for in vivo EBOV pathogenesis and to confirm them as relevant targets of future filovirus therapeutics. Macrophage phenotypes can vary greatly depending upon chemokine and cytokine signals from their microenvironment. Historically, macrophages have been classified into two major subgroups: classically activated macrophages (M1) and alternatively activated macrophages (M2). Macrophages are a critical early target of EBOV infection and my work primarily focused on interferon gamma-stimulated (M1) macrophages since this treatment profoundly inhibited EBOV infection of human and murine macrophages. Interferon gamma treatment blocked EBOV replication in macrophages, reducing viral RNA levels in a manner similar to that observed when cultures were treated with the protein synthesis inhibitor, cycloheximide. Microarray studies with interferon gamma-treated human macrophages identified more than 160 interferon-stimulated genes. Ectopic expression of a select group of these genes inhibited EBOV infection. These studies provide new potential avenues for antiviral targeting as these genes that have not previously appreciated to inhibit infection of negative strand RNA viruses including EBOV. In addition and most exciting, using MA-EBOV, we found that murine interferon gamma, when administered either 24 hours before or after infection, protects lethally challenged mice and significantly reduces morbidity. Our findings suggest that interferon gamma, an FDA-approved drug, may serve as a novel and effective prophylactic or treatment option.

Streptococcus thermophilus est la bactérie lactique la plus utilisée après Lactococcus lactis dans l’industrie laitière pour la fabrication de yaourts et de fromages. Il s’agit du seul streptocoque à avoir le statut de bactérie GRAS (Generally Recognized As Safe). Malgré de récentes études montrant sa capacité à survivre dans le tractus digestif humain et des effets santé intéressants, le statut probiotique de S. thermophilus reste l’objet d’interrogations. Ainsi, les objectifs de cette thèse ont été (i) d’approfondir les connaissances sur la capacité de survie de S. thermophilus en conditions digestives humaines simulées, grâce, en particulier, au système dynamique multi-compartimenté TIM (TNO gastro-intestinal model) et (ii) d’identifier des gènes de S. thermophilus spécifiquement activés dans des conditions complexes comme l’environnement digestif, à l’aide de la technologie R-IVET (Recombinase-based In Vivo Expression Technology) basée sur l’excision d’un gène rapporteur. Le système R-IVET est composé d’un vecteur plasmidique portant la recombinase cre démunie de son promoteur et d’une cassette chromosomique composée d’un gène marqueur entouré de sites loxP reconnus par Cre. Ainsi, dans un premier temps, nous avons implanté la technologie R-IVET chez S. thermophilus LMD-9. Sa fonctionnalité a été testée et validée in vitro et dans le tractus digestif de la souris. Puis, l’étude de la survie de quatre souches de S. thermophilus dans le système TIM a montré que trois d’entre elles étaient plus résistantes que la quatrième, très sensible aux stress gastro-intestinaux. Ces résultats confirment donc que la survie de S. thermophilus dans l’environnement digestif est souche-dépendante. Ils montrent également que la survie de S. thermophilus est influencée par la matrice alimentaire, celle-ci étant plus importante en lait fermenté qu’en lait liquide. Enfin, dans un troisième temps, nous avons construit une première banque génomique R-IVET, en clonant en amont de cre des fragments d’ADN génomiques provenant de LMD-9. Cette banque a été testée uniquement en conditions gastriques simulées dans le TIM. Puis, après avoir optimisé notre outil chez S. thermophilus en améliorant la méthode d’identification des gènes activés, une seconde banque R-IVET a été testée dans l’ensemble du tractus gastro-intestinal (TIM) et en système batch en présence du microbiote intestinal. Ces expériences nous ont permis de mettre en évidence, pour la première fois, des gènes de S. thermophilus spécifiquement activés dans les différents compartiments digestifs de l’homme. Ce travail de thèse contribue ainsi à approfondir les connaissances sur le comportement de cette bactérie dans le tractus gastro-intestinal humain. A moyen terme, ces travaux devraient permettre d’identifier des marqueurs de survie de S. thermophilus et de mieux comprendre son activité métabolique dans l’environnement digestif, facilitant la sélection de souches dans la perspective de développement d’aliments fonctionnels. / Streptococcus thermophilus is the lactic acid bacterium most commonly used after Lactococcus lactis in the dairy industry for the production of yogurt and cheese. It is the only streptococcus strain to have the GRAS status (Generally Recognized As Safe). Despite recent studies showing its ability to survive through the human digestive tract and valuable health effects, the probiotic status of S. thermophilus remains questioned. Thus, the objectives of this pHD work were (i) to increase knowledge on the survival of S. thermophilus in human digestive environment, by using the dynamic multi-compartmental TIM system (TNO gastro-intestinal model) and (ii) to identify the genes from S. thermophilus that are specifically activated in complex digestive environment using the R-IVET technology (Recombinase-based In Vivo Expression Technology). R-IVET is based on the excision of a reporter gene and consists of a plasmid vector carrying the promoterless recombinase cre and a chromosomal cassette composed of a marker gene flanked by loxP recognized by Cre. First, we introduced the R-IVET technology in S. thermophilus LMD-9. Its functionality was tested and validated in vitro and in the mice digestive tract. Then, the survival of four S. thermophilus strains was investigated in the TIM system and we showed that 3 of these strains were more resistant than the other one, very sensitive to gastrointestinal stresses. These results strengthen the idea that the survival of S. thermophilus is strain-dependent. We also highlighted that the survival of S. thermophilus was influenced by the food matrix, being higher in fermented compared to liquid milk. Lastly, we constructed a first genomic R-IVET library, by cloning upstream of cre genomic DNA fragments from LMD-9. This library was tested only in gastric condition (TIM). After optimization of our tool in S. thermophilus (improvement of the method allowing identification of the activated genes), a second R-IVET library was tested throughout the gastrointestinal system (TIM) and in batch system including intestinal microbiota. By identifying bacterial genes specifically activated in human digestive conditions, this work contributes to extend our knowledge on the behavior of S. thermophilus in the human gastrointestinal tract. This could open up opportunities in determining survival markers for S. thermophilus and better describing its metabolic activity in the human gut, then facilitating the selection of strains that can be included in functional foods.

Les lymphocytes T cytotoxiques (CTLs) présents au niveau des tumeurs reconnaissent des antigènes présentés par les cellules cancéreuses, mais ne parviennent pas à induire le rejet de ces tumeurs chez les patients cancéreux. Cette observation a amené les immunologistes à étudier les différents mécanismes d'immunosuppression induits par les tumeurs qui permettent aux cellules cancéreuses d'échapper à la reconnaissance et à la destruction immunitaires. L'un des mécanismes contribuant à la résistance des tumeurs aux réponses immunitaires est le recrutement de lymphocytes T CD4+ régulateurs (Tregs). Les Tregs s'accumulent au niveau des sites tumoraux et jouent un rôle important dans la suppression des réponses immunitaires dirigées contre les cellules tumorales. Dans ce travail de thèse, nous rapportons que des épitopes tumoraux dérivés des protéines NY-ESO-1 et TRAG-3 stimulent à la fois des lymphocytes T CD4+ auxiliaires (Th) et des Tregs chez des patients porteurs de mélanome. Grâce à une analyse clonotypique, nous démontrons que, contrairement aux cellules CD4+ Th, les TCR des Tregs dirigés contre NY-ESO-1 et TRAG-3 sont retrouvés à la fois dans le répertoire des Tregs naturels (CD4+CD25high) et dans celui des cellules T CD4+ classiques/Th (CD4+CD25-), au niveau des PBMCs des patients. Cette observation suggère que le recrutement des Tregs spécifiques d'antigènes tumoraux se fait en partie par la conversion des cellules T CD4+ classiques suite à leur stimulation chronique par des antigènes de tumeurs. / Cytotoxic T lymphocytes (CTLs) present in tumors recognize tumor antigens presented by cancer cells but fail to induce tumor rejection in patients. This observation has led immunologists to study the different mechanisms of tumor-induced immunosuppression that allow cancer cells to escape from recognition and destruction by the immune system. One of the mechanisms contributing to tumor resistance to immune responses is the recruitment of CD4+ regulatory T cells (Tregs). Tregs accumulate at tumor sites and play an important role in suppressing immune responses against tumor cells. In this thesis, we report that tumor epitopes derived from the proteins NY-ESO-1 and TRAG-3 stimulate both CD4+ T helper cells (Th) and Tregs in patients with metastatic melanoma. Through clonotypic analysis, we show that, within PBMCs of melanoma patients, tumor antigen-specific Tregs, but not Th cells, share a common TCR usage with naturally-occuring Tregs (CD4+CD25high) and Th cells (CD4+CD25-), suggesting that their recruitment occurs through the peripheral conversion of CD4+CD25- T cells upon chronic antigen exposure. The second part of this thesis consists of the study of inhibitory receptors expressed by CTLs directed against tumor antigens which, upon engagement by their ligands presented on the surface of tumor cells, activate negative regulatory pathways. Here, we report that tumor-induced CTLs directed against a peptide derived from NY-ESO-1 in melanoma patients upregulate the expression of the inhibitory receptors PD-1, Tim-3 and BTLA. Additionaly, the co-expression of PD-1 with Tim-3 and/or BTLA defines populations of dysfunctional tumor antigen-specific CTLs.

A história de dois programas infantis de grande repercussão no Brasil, Vila Sésamo (TV Cultura-TV Globo/1972) e Rá Tim Bum (TV Cultura/1990), indica quais são as características da produção educativa brasileira. Eles apresentam um conflito estrutural entre o método de planejamento educacional, de origem norte-americana, e o repertório cultural dos produtores e do público-alvo. A representação deslocada de infância, relações sociais e Educação dos programas educativos comprometeriam seu impacto sobre o público-alvo. Buscando estabelecer quais os critérios mais adequados para programas educativos nacionais, sugere-se a incorporação da perspectiva de Paulo Freire sobre Comunicação e Educação pelas produções brasileiras. Para Freire, o processo educativo se desenvolve a partir do repertório cultural do educando e o estimula a transformar seu ambiente. Num momento de consolidação da democracia na América Latina, entende-se educar através da televisão como construção simbólica e prática da cidadania, onde produtores e receptores dialogam e se reconhecem como sujeitos do mesmo processo social. Planejar programas com estes propósitos requer a criação de parâmetros a partir da prática da produção cultural no país e da realidade objetiva do público-alvo. Este trabalho sugere critérios básicos para futuras produções de produtos educativos dirigidos às crianças brasileiras, em contraposição ao condicionamento para o consumo proposto pelos programas importados, tidos equivocadamente como educativos. / The history of two children programs of strong impact in Brazil, Vila Sésamo (TV Cultura-TV Globo/1972) and Rá Tim Bum (TV Cultura/1990), points out what the Brazilian educational production characteristics are. They show a structural conflict between the educational planning method of Northern American origin and the producers’ and target audience’s cultural background. Aimed at establishing the most adequate criteria for national educational programs, it is suggested that Paulo Freire’s perspective on Communication and Education by the Brazilian productions be incorporated. To Freire, the educational process starts from the learner’s cultural background and it stimulates him/her to transform his/her environment. At a democracy consolidation moment in Latin America, education through television is understood as symbolic and practical construction of citizenship, where producers and viewers dialogue and recognize themselves as agents in the same social process. Planning programs for educational purposes requires the creation of parameters departing from the country’s cultural production practice and from the target audience’s objective reality. This dissertation suggests basic criteria for making future educational products aimed at Brazilian children, which are opposed to the consumerism conditioned by imported programs mistaken as educational.