No description available.

Les troubles bipolaires (TB) sont des troubles chroniques, multifactoriels et multi-systémiques avec une morbidité, mortalité et fardeau socio-économique très élevée. Mieux comprendre le fond génétique et les facteurs environnementaux déclencheurs permettra d'améliorer le diagnostic et la prise en charge thérapeutique. La dysimmunité semble être parallèle à l'apparition, la progression ainsi qu'au développement de comorbidités psychiatriques et somatiques. L'inflammation chronique et l'activation de la microglie sont des mécanismes liant potentiellement l'infection et le stress pendant l'enfance avec la survenue d'un TB, en particulier la plus sévère forme d'apparition précoce. Les variants génétiques des récepteurs de reconnaissance de motifs moléculaires, première ligne de défense immunitaire, pourraient participer à la résilience/vulnérabilité aux facteurs de risque environnementaux tôt au cours de la vie. Nous avons exploré cette possibilité en analysant les associations génétiques entre des acteurs centraux de la réponse immunitaire innée, TLR2, TLR4 et NOD2 et les TB, en testant aussi l'hétérogénéité entre les sous-groupes d'apparition précoce et tardive. Étant donné que l'activation de ces voies augmente la production d'oxyde nitrique (NO) et en vue de son rôle dans l'inflammation, le stress oxydatif et la neurotransmission ainsi que son dysfonctionnement dans les TB et suicide, nous avons analysé simultanément des variants génétiques des trois isoformes de NO-synthase (NOS) chez les patients avec antécédents de conduites suicidaires. Nous avons trouvé que les génotypes TLR4 rs1927914 AA et rs11536891 TT sont significativement plus fréquents chez les patients tandis que l'allèle NOD2 rs2066842 T est significativement plus fréquent chez les témoins suggérant une vulnérabilité génétique à l'exposition aux pathogènes dans les TB. En plus, l'association avec TLR4 est restreinte au sous-groupe à début précoce et le génotype TLR2 rs3804099 TT est significativement plus fréquent chez les patients à début précoce qu'à début tardif, confortant l'hypothèse que les facteurs génétiques ont un poids plus important dans les TB d'apparition précoce. Des associations entre NOS1, NOS2 et NOS3 et TB n'ont pas été observées mais NOS3 rs1799983 T à l'état homozygote a été associé aux tentatives de suicide violentes, chez les patients à début précoce, apportant une preuve supplémentaire de l'implication de variants de NOS3 (endothéliale) dans les conduites suicidaires. En étudiant l'effet de l'interaction entre les variants génétiques de TLR2/TLR4 et les antécédents d'abus dans l'enfance mesurées par le Childhood Trauma Questionnaire (CTQ) sur l'âge de début des TB, nous avons observé un effet combiné du génotype TLR2 rs3804099 T avec antécédents d'abus sexuels sur la détermination d'un âge plus précoce d'apparition des TB. Les effets de l'abus sexuel dans l'enfance sur l'âge d'apparition des TB peuvent être accrus chez les porteurs du génotype TLR2 rs3804099 TT potentiellement médié par des voies liés aux réponses inflammatoires. Nos résultats sont en faveur d'un modèle « multiple-hit » dans lequel une vulnérabilité génétique liée au système immunitaire contribuerait à des réponses anormales aux infections périnatales baissant le seuil pour les effets adverses des stress ultérieurs. La confirmation de ces données par réplication dans des cohortes indépendantes est nécessaire. La caractérisation de la sévérité de la maladie, des phénotypes immunitaires et du type, intensité, fréquence et moment de survenue des stress doivent être prévues dans les futures études. Le développement de modèles animaux pourra aussi permettre de mieux comprendre les mécanismes impliqués à travers la manipulation expérimentale de la génétique et des conditions environnementales. Ces approches pourraient permettre l'identification de biomarqueurs et de signes cliniques prodromiques bien que des nouvelles stratégies de prévention et des cibles thérapeutiques. / Bipolar disorders (BD) are chronic, multisystem and multifactorial disorders with significant lifetime morbidity, mortality and socioeconomic burden. Understanding its genetic background and triggering environmental factors should improve diagnosis and therapeutic management. Immune dysregulation seems to parallel its onset and progression as well as the development of psychiatric and other medical comorbidities. Chronic low-grade inflammation and microglia activation are thought to be important mechanisms linking infection and childhood trauma with BD, in particular the more severe early-onset subform. Genetic variations in pattern-recognition receptors, the first line of immune defence, may thus participate in one's resilience/vulnerability to environmental exposures, particularly early in life. We explored that possibility by investigating genetic associations between central players of innate immune protection, TLR2, TLR4 and NOD2 and BD, taking into account the potential genetic heterogeneity between the early- and late-onset subgroups. Given that the activation of these pathways increases the production of nitric oxide (NO), a potent innate immune effector, by immune cells and taking into consideration the role of NO in oxidative stress and neurotransmission as well as its dysfunction in both BD and suicide, we simultaneously analysed variants of the three isoforms of nitric oxide synthase (NOS) genes with suicidal behaviour in BD. We found TLR4 rs1927914 AA and rs11536891 TT genotypes to be significantly more prevalent in patients than in controls. We also found that NOD2 rs2066842 T allele carrier state may confer some protection against BD as it was more prevalent in controls. These results suggest a genetic vulnerability to pathogen exposure in BD. We also found that the referred association with TLR4 was restricted to the early-onset subgroup and that a TLR2 genotype (rs3804099 TT) was significantly more prevalent in early- than in late-onset patients comforting the hypothesis that genetic factors are of greater importance in early-onset BD. While associations between NOS1, NOS2 and NOS3 with BD were not observed, NOS3 rs1799983 T in homozygous state was associated with violent suicide attempts, seemingly restricted to the early-onset BD bringing further evidence for the potential involvement of endothelial NOS genetic variants in the susceptibility to suicidal behaviour. By investigating the effect of potential interaction between TLR2 and TLR4 and childhood abuses as measured by the Childhood Trauma Questionnaire (CTQ) on the age at onset of BD, we observed a combined effect of TLR2 rs3804099 TT genotype and childhood sexual abuse on determining an earlier age at onset of BD by means of a Kaplan-Meier survival curve. The effects of childhood sexual abuse on age at onset of BD may be amplified in TLR2 rs3804099 risk genotype carriers through immune-mediated pathways.Altogether the present results comfort a multiple-hit model in which immune-related genetic susceptibility contributes to abnormal responses to perinatal infectious insults establishing a lower threshold for subsequent stress-triggered events. Confirmation by replication in independent BD cohorts is warranted. Characteristics of illness severity, immune phenotypes and detailed annotation of type, intensity, frequency and time of stress exposure should be documented in future studies involving large cohorts. Additionally, the development of animal models in conformity with the presented model would facilitate better understanding of the precise mechanisms involved by allowing specific manipulation of genetic and environmental conditions. These approaches may allow the identification of both biological and clinical prodromal manifestations and consequently lead to preventive strategies and novel therapeutic targets.

During mitogen-induced transformation of human lymphocytes, phosphoglycerate kinase (PGK) exhibits new electrophoretic forms (pl=8.5-8.9). Electrophoresis and electrofocusing showed that the new forms are not due to expression of the autosomally linked isozyme found in semen (PGK-B; pl=9.7). The multiple electrophoretic forms are the result of protease modification of sex-linked PGK-A isozyme.When peripheral lymphocytes from young persons are stimulated in vitro with phytohemagglutinin, a selective increase in the levels of the glycolytic enzymes occurs concomitantly with blastogenesis. Human lymphocytes from a geriatric population were also subjected to mitogen stimulation. The initial levels of the enzymes were essentially identical in lymphocytes from young and old subjects as were mitogenfree cultured controls. However, during mitogen stimulation the cells from the old subjects failed to increase the glycolytic enzymes. This inability to activate glycolysis may be related to the decline in cell-mediated immunity which occurs with advancing age. Triosephosphate isomerase (TPI) has an increased thermolabile component in skin fibroblasts from patients with progeria (41.4 per cent)and Werner's syndrome (20.1 per cent) when compared with normal fibroblasts (0-3 per cent). The incorporation of various protease inhibitors failed to affect the percentages of heat-labile triosephosphate isomerases. The labile component appears to be identical to the deamidated form of the enzyme which accumulates in other aging cells. Isoelectric focusing demonstrated increased quantities of the deamidated TPI-A form in progeria and Werner's syndrome fibroblasts as compared to normal. The deamidated TPI-A was considerably more labile than the native TPI-B indicating the increased lability of triosephosphate isomerase in premature aging syndrome fibroblasts is due to an accumulation of the deamidated form of the enzyme. The levels of several proteases were found to be diminished in progeria fibroblast extracts as compared to normal. A deamidation mechanism of enzyme degradation plays a key role in the normal cellular catabolism of this enzyme and the mechanism for accumulation of defective forms in aging cells is apparently exacerbated by an impaired proteolytic capacity.

Mast cells are critical effectors of allergic disease that can be activated by numerous stimuli. We have examined mast cell control by the inflammatory cytokine, IL-33, as well as IgG. In the first study reported here, we found that the synthetic glucocorticoid, dexamethasone, potently and rapidly suppressed IL-33-induced cytokine production from murine bone marrow–derived and peritoneal mast cells, as well as human mast cells. Dexamethasone also antagonized IL-33-mediated enhancement of IgE-induced cytokine production and migration. Although dexamethasone had no effect on IL-33-induced phosphorylation of MAP kinases or NFκB p65 subunit, it antagonized AP-1 and NFκB-mediated transcriptional activity. Finally, intraperitoneal administration of dexamethasone completely abrogated IL-33-mediated peritoneal neutrophil recruitment and prevented plasma IL-6 elevation. These data demonstrate that steroid therapy may be an effective means of antagonizing the effects of IL-33 on mast cells in vitro and in vivo, acting partly by suppressing IL-33-induced NFκB and AP-1 activity. In the second study reported here, we found that Fcγ receptor crosslinkage activated the transcription factor Stat5B through a Fyn kinase-dependent pathway. We then showed that STAT5B is critical for IgG-induced cytokine production by mast cells but not macrophages. To expand these studies, we employed the K/BxN model of inflammatory arthritis, which has roles for mast cells and macrophages. In this model, Fyn or STAT5B deficiency only affected the arthritic flare that primarily depends on mast cell degranulation, without affecting the severity of the joint swelling. By contrast, Lyn kinase deficiency significantly exacerbated arthritis. These studies indicate a clinically relevant, lineage-restricted role for the Lyn/Fyn-STAT5 cascade. Collectively, our work demonstrates that mast cell activation by diverse stimuli can be suppressed by steroid intervention and selectively targeted by disrupting kinase-transcription factor pathways.

Dans les écosystèmes littoraux, l‘activité anthropique, mais aussi le contexte naturel induisent chez les organismes aquatiques des situations de « multistress ». Parmi les sources potentielles de perturbation, trois d‘entre elles ont été étudiées : contamination métallique, infection bactérienne et infestation parasitaire. Une approche intégrée de leurs interactions sur la réponse génétique, protéique, cellulaire et populationnelle chez la coque Cerastoderma edule et la palourde japonaise Ruditapes philippinarum a été entreprise sur le terrain et en laboratoire. In situ, un suivi de deux ans a été mené sur quatre populations de bivalves issues d‘environnements différents afin d‘estimer la santé des populations (paramètres de dynamique de population), de la mettre en rapport avec les niveaux de base des stress subis (métaux, parasites) et d‘évaluer les réponses adaptatives mises en place par les bivalves en termes de détoxication et de défenses immunitaires. Cette approche a permis de décrire un certain nombre de scenarii concernant les relations entre des populations de bivalves et leur environnement. En laboratoire, des expériences de co-infestation contrôlées (parasite trématode Himasthla elongata, bactérie Vibrio tapetis) en milieu indemne de métaux ou contaminé au cadmium ont été menées sur certaines de ces populations et montrent que la réponse des bivalves à ces agressions multiples dépend des espèces, des combinaisons subies, et ne se déduit pas intuitivement à partir des réponses « mono-stress », soulignant ainsi la notion d‘interactions. Malgré la complexité et la diversité de ces dernières, certains mécanismes semblent prédominer quelle que soit l‘espèce étudiée. Alors que l‘infestation par le parasite ne semble pas modulée par la présence du métal ou de la bactérie dans le milieu, la bioaccumulation métallique est fortement influencée par la présence d‘un ou plusieurs agents pathogènes. En plus de perturber l‘accumulation du polluant, la présence d‘organismes pathogènes interfère dans les mécanismes de détoxication cellulaire avec notamment une perturbation de la synthèse des métallothionéines (MT). Des travaux menés plus particulièrement sur la réponse des MT chez la coque exposée à un métal, à travers l‘expression de l‘isoforme Cemt1 et la synthèse de la protéine, confirment la complémentarité des observations (génétique et protéique) ainsi que la nécessité d‘observer les réponses des organismes à différentes échelles afin d‘avoir une vision globale des processus interactifs existants entre polluants et pathogènes. Des interactions fortes sont révélées au niveau génétique, protéique et immunitaire: « cadmium x trématode » chez la coque et « bactérie x trématode » chez la palourde. Enfin ces expériences, en parallèle du suivi in situ, mettent en évidence le rôle majeur de l‘histoire de vie dans la sensibilité des organismes aux interactions polluants-pathogènes. / In coastal ecosystems, man-mediated activity and natural context induce a ?multistress? situation in aquatic organisms. Amongst potential perturbation sources, three of them were studied: metal contamination, bacterial infection and parasite infestation. An integrated approach of their interactions on genetic, protein, cellular and population dynamics responses in the cockle (Cerastoderma edule) and the Manila clam (Ruditapes philippinarum) was undertaken through field and laboratory studies. A two-years monitoring was conducted in four bivalve populations from different environments to estimate the fitness of populations (parameters of population dynamics), in relation with the baseline levels of stressors (metals, parasites) and with the adaptive responses implemented by bivalves in terms of detoxification and immunity. This approach allowed describing different scenarii concerning the relationship between bivalve populations and their environment. In laboratory, co-infection experiments (trematode parasite Himasthla elongata, bacteria Vibrio tapetis) were conducted on these populations in controlled condition with or without metal contamination (cadmium). They showed that the response of bivalves to stress is species-dependent. Combinations were not intuitively deduced from the "mono - stress" responses underscoring the concept of interactions. Despite the complexity and diversity of these interactions, some mechanisms predominated regardless of the studied species. While parasite infestation was not modulated by the presence of metal or bacteria in the environment, metal bioaccumulation in turn was strongly influenced by the presence of one or several pathogens. Beyond disrupting the accumulation of pollutants, the presence of pathogens interfered with the cellular detoxification mechanisms including impairment of the metallothionein (MT) synthesis. A focus on the response of MT in cockles exposed to a metal through the expression of isoform Cemt1 and protein synthesis confirmed the complementary of these observations (gene and protein). They also highlighted the need to analyze responses at different scales to obtain an overview of existing interactive process between pollutants and pathogens. Strong interactions were found: ?Cd x parasite? in the cockle and" bacteria x parasite "in the clam, at the genetic, protein and immune levels. Finally, these experiments highlighted the important role of life history on the sensitivity of organisms to pollutant-pathogen interactions.

Orientador: Cláudia Regina Cavaglieri / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-22T09:26:18Z (GMT). No. of bitstreams: 1 Brunelli_DiegoTrevisan_M.pdf: 1612814 bytes, checksum: 8204a7a9c4c4548d04076ee08e2bb9dc (MD5) Previous issue date: 2013 / Resumo: Para melhorar a forma física, atletas geralmente enfrentam períodos intensos de estresse físico seguidos de uma diminuição no nível desse estresse com o intuito de gerar adaptações a nível celular. Por esse motivo, esforços extensos são realizados no intuito de quantificar objetivamente o fino balanço entre a intensidade do treinamento e a capacidade de tolerância do atleta, onde o monitoramento de diferentes variáveis durante uma temporada esportiva pode contribuir na modulação das cargas de treinamento. Dentre essas variáveis, destacam-se os parâmetros do sistema imunológico como um dos fatores importante na preparação do atleta durante a temporada esportiva, pois supressões temporárias da resposta imune às ameaças ambientais podem levar à ocorrência de infecções do trato respiratório superior (ITRS), o que pode influenciar drasticamente a preparação e a capacidade competitiva de atletas. Não foram observados estudos que realizaram o monitoramento da resposta imune de atletas adolescentes durante os diferentes períodos de uma temporada esportiva, principalmente quando engajados em esportes coletivos ou times esportivos, muito populares nesta faixa etária. Assim, o objetivo do presente estudo foi monitorar as respostas imunológicas, hormonais e a incidência de ITRS de atletas adolescentes de basquetebol durante duas temporadas esportivas. Na primeira temporada, as contagens leucocitárias, incidência de sintomas de ITRS e as mudanças das cargas de treinamento foram monitoradas antes (M1) e após 8 semanas (M2), equivalente ao período preparatório da temporada esportiva realizada no ano de 2010. Foram observadas: diminuições nos monócitos no M2 comparado ao M1(p = 0,004); cargas de treino da semana 6 foram maiores comparadas às semanas 1, 2, 4 e 8 (p < 0,05); Semanas 1 e 2 apresentaram maiores incidências de ITRS. Nossos resultados demonstraram que as variações nas cargas de treinamento semanal não se correlacionaram com as ocorrências de ITRS auto-reportadas, sugerindo assim que esta população pode ter uma resposta atenuada nas perturbações do sistema imune relacionadas ao exercício. Na segunda temporada, as respostas imunes, hormonais e a incidência de ITRS foram monitoradas antes (Pré-Temporada) e após 6 (Preparatório) e 20 semanas (Competitivo) da temporada esportiva realizada durante o ano de 2011. Foi observado: aumento significante (38%) na ocorrência de ITRS no período competitivo comparado ao preparatório; aumento significativo de monócitos (p=0,0054), cortisol (p=0,0002), TNF-? (p=0,0001) e PCR (p=0,0017) e diminuição da IL-10 (p=0,0077) no momento Competitivo comparado ao momento Pré-Temporada. Os resultados do presente estudo sugerem que o aumento das ocorrências de ITRS experimentadas por atletas adolescentes durante a etapa competitiva pode ser decorrente dos efeitos indesejados do processo inflamatório em resposta a possíveis microtraumas musculares, uma vez que as respostas imunológicas destes indivíduos parecem estar adaptadas aos diferentes períodos da temporada esportiva. Ainda, o estado inflamatório e catabólico evidenciado ao final da etapa competitiva não foram capazes de prejudicar no desempenho neuromuscular e funcional de atletas adolescentes de basquetebol / Abstract: To improve physical performance, athletes often use periods of heavy physical stress followed by a reduction in stress level to achieve specific adaptations at the cellular level. Therefore, extensive efforts are made to quantify objectively the fine balance between training intensity and athlete's tolerance, where monitoring of different variables during a sports season can contribute to the modulation of loads during the training process. Among these variables, we highlight the immune system parameters as important factors in the preparation of the athlete during the sports season because temporary suppressions of the immune response to environmental threats can lead to occurrence of episodes of upper respiratory tract infections symptoms (URTI), which can dramatically influence the preparation and competitive programs of an athlete. No studies were found that aimed to monitor the immunological responses for different training periods in adolescents athletes engaged on team sports, which are very popular in these age groups. Thus, the objective of this study was to evaluate the immune and hormonal responses and the occurrence of episodes of URTI in a group of adolescent male athletes during two basketball seasons. In the first season, the WBC counts, incidence of URTI symptoms and changes in training loads were monitored before (M1) and after 8 weeks (M2), equivalent to the preparatory period of the sports season held in 2010. There were found a significant decrease in monocytes at M2 compared to M1 (P = 0.004). There were no significant alterations in total leukocytes (P = 0.07), neutrophils (P = 0.07), or lymphocytes (P = 0.09). No significant changes in plasma concentrations of TNF-? (P = 0.30) or IL-6 (P = 0.90) were found. The weekly load from week 6 was higher when compared with weeks 1, 2, 4, and 8 (P < 0.05), and week 8 was the lowest when compared with week 5 (P < 0.05). Self-reported URI incidences were highest at weeks 1 and 2. Our results demonstrated that variations in weekly training load during the preparatory period were not correlated with changes in self-reported occurrence of URI incidences, suggesting that adolescent athletes may have an attenuated response to exercise-induced perturbations to the immune system. In the second season, the immune and hormonal responses and the incidence of URTI were monitored before (Pre-Season) and after 6 (Preparatory) and 20 weeks (Competitive) of the sports season held during the year 2011. There were found significant increase (38%) in the occurrence of URTI during the Competitive moment as compared to Preparatory. There were found significant increases in monocytes (p=0.0054), cortisol ((p=0.002), Tumor necrosis factor-? (p=0.0001) and C-reactive Protein (0.0017) in the Competitive moment as compared to Preparatory, as well as a decrease in interleukin-10 (p=0.0077) at the same moments of evaluation. The results of this study suggest that increased occurrence of URTI experienced by adolescent athletes during the competitive stage may be due to the unwanted effects of an inflammatory process in response to muscle micro-trauma since the immune responses of these individuals seems to be adapted to the different periods of the sports season. In addition, the inflammatory and catabolic states observed at the end of the competitive stage were not able to affect the neuromuscular and functional performances in adolescent basketball athletes / Mestrado / Atividade Fisica Adaptada / Mestre em Educação Física

Philosophiae Doctor - PhD / This study aimed to investigate the effects of commercially available natural (sugar cane molasses, white sugar and brown sugar) and artificial (Canderel, Equal, Natreen, Sweetex, Splenda and Swheet) sweeteners on various physiological systems. The artificial sweeteners tested in this study may be categorised into their respective groups based on their primary ingredient. The brands Canderel and Equal contain aspartame, Natreen and Sweetex consist of saccharin and Splenda and Swheet are composed of sucralose. The inclusion of artificial or natural sweeteners in the human diet has been continually debated and their implication in the development of certain diseases has raised concern regarding their safe use. Therefore, it is necessary that these food products be subjected to a battery of tests to determine adverse effects on human health. / South Africa

Orientador: Edgard Graner / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-28T00:41:43Z (GMT). No. of bitstreams: 1 Melo_EstevaoAzevedo_M.pdf: 1050744 bytes, checksum: b28d2d7f1bf1683ed75a9b3e47166ad2 (MD5) Previous issue date: 2015 / Resumo: A ácido graxo sintase (FASN) é a enzima responsável pela biossíntese endógena de ácidos graxos e apontada como uma oncoproteína metabólica, por favorecer a proliferação e sobrevivência das células tumorais nas quais sua expressão é elevada. Vários são os compostos capazes de inibir a atividade de FASN, dentre eles o orlistat (Xenical®), que possui efeitos antiproliferativos previamente mostrados em células de câncer de mama, próstata, boca e melanoma. O sistema imunológico apresenta um importante papel na prevenção e defesa do organismo contra neoplasias malignas. As células do sistema imune que se infiltram nos melanomas são produtoras de uma vasta gama de citocinas, dentre elas interleucina 12 (IL-12) e interferon gama (IFN-?) que favorecem uma resposta imune bem sucedida contra os tumores, porém, as células dos melanomas possuem capacidade de produzir interleucina 10 (IL-10) e fator de crescimento transformante beta (TGF-?), capazes de inibir as células imunocompetentes, favorecendo a progressão tumoral e disseminação metastática. O objetivo deste estudo foi avaliar a secreção das citocinas IL-10, IL-12, IFN-? e TGF-? pelas células de melanoma murino B16-F10 após tratamento com orlistat. Para isto, inicialmente determinou-se a dosagem de orlistat capaz de inibir a proliferação celular em 50% (IC50). Em seguida, as células foram tratadas por 24 e 48 horas, quando realizou-se a quantificação da secreção das citocinas por ELISA. Após 24 horas de tratamento, observou-se aumento da secreção de IL-10 e IL-12, no entanto, após 48 horas de tratamento não foi detectada diferenças estatisticamente significantes na secreção de ambas as citocinas, quando comparadas aos seus controles. IFN-? e TGF-? não foram detectáveis. Assim, os resultados desta pesquisa mostram que o tratamento com orlistat alterou a produção das citocinas IL-10 e IL-12, sugerindo que o tratamento promove um equilíbrio entre estas citocinas pró e anti-inflamatórias nas células estudadas / Abstract: Fatty acid synthase (FASN) is the enzyme responsible for the endogenous biosynthesis of fatty acids suggested as a metabolic oncoprotein by promoting proliferation and survival of cancer cells. Several compounds are known to inhibit FASN activity, including orlistat (Xenical®), which has antiproliferative effects in breast, prostate, and oral cancer as well as melanoma cells. Melanoma is an aggressive malignant tumor of melanocytes with high propensity for metastatic spread and resistant to chemotherapy. The immune system plays an important role in the prevention and defense against malignant neoplams. In fact, immune cells that infiltrate melanomas produce a wide range of cytokines, such as interleukin 12 (IL-12) and interferon gamma (IFN-?), which favor a successful immune response against the tumor. However, melanomas cells are able to produce interleukin 10 (IL-10) and transforming growth factor beta (TGF-?) and in turn inhibit immunocompetent cells, favoring tumor progression and metastatic spread. The aim of this research was to evaluate the effect of the FASN inhibitor orlistat on the secretion of the cytokines IL-10, IL-12, IFN-? and TGF-? by B16-F10 mouse melanoma cells. For this purpose, we first searched for the IC50 Of orlistat in B16-F10 cells. Then, cells were treated for 24 and 48 hours with the drug and the secretion of cytokines quantified by ELISA. After 24 hours of treatment the secretion of IL-10 and IL-12 was increased, however, after 48 hours there were no statistically significant changes in the secretion of both cytokines, compared to their controls. IFN-? and TGF-? were not detectable. Thus, the results of this study show that the treatment with orlistat change the production of IL-10 and IL-12, suggesting a balance between the secretion of pro- and anti-inflammatory cytokines / Mestrado / Estomatopatologia / Mestre em Estomatopatologia

O mecanismo de imunorregulação gerado pelo catabolismo do triptofano pela IDO protege o feto contra a resposta imunológica materna. Neste estudo, esse mecanismo foi em avaliado em gestantes imunossuprimidas e portadoras de transplante renal. Examinou-se a expressão da IDO e sua atividade nos compartimentos placentários de gestantes saudáveis e portadoras de transplante. Células produtoras de IDO e IFN-<font face=\"Symbol\">g foram imunolocalizadas na região vilosa e região decidual em ambos os grupos analisados, com mudanças no tipo celular envolvido nestas expressões nas gestantes transplantadas. Os níveis de IDO e sua atividade, assim como seus fatores de regulação NF-kB, IFN-<font face=\"Symbol\">g e IL-10 estavam diminuídos na região vilosa. No compartimento decidual a atividade enzimática da IDO estava aumentada nas gestantes transplantadas, mas não dos seus reguladores. Sendo assim, eixo de imunorregulação gerado por IDO-IFN-<font face=\"Symbol\">g na interface placentária de gestantes portadoras de transplante renal responde diferencialmente a insultos ocasionados pela utilização de imunossupressores durante a gestação. / The mechanism of immunoregulation generated by the catabolism of tryptophan by IDO protects the fetus against maternal immune response. In this study, this mechanism was evaluated in renal transplanted pregnant women and immunosuppressed. We examined the expression and activity of IDO in placental compartments of healthy pregnant women and patients with transplants. IDO and IFN-<font face=\"Symbol\">g producing cells were imunolocalizated in villous and decidual region in both groups analyzed, with changes in cell type involved in these expressions in pregnant patients transplanted. The levels and activity of IDO, as well as their regulatory factors NF-kB, IFN-<font face=\"Symbol\">g and IL-10 were decreased in the villous region. In the decidual compartment IDO activity was increased in pregnant women transplanted, but not their regulators. Thus, the axis of immunoregulation generated by IDO and IFN-<font face=\"Symbol\">g in placental interface of pregnant women with renal transplantation responds differently to insults caused by the use of immunosuppressive drugs during pregnancy.

Células dendríticas são importantes na interação dos sistemas imune inato e adaptativo, apresentando antígenos para linfócitos T CD4+ e CD8+ e induzindo respostas adaptativas contra estes. Elas são alvo de interesse no desenvolvimento de novas estratégias vacinais que visam o direcionamento de antígenos para as diferentes populações de DCs in vivo. Consiste na administração de anticorpos contra receptores da superfície da DC em fusão com o antígeno. Nós comparamos o direcionamento da proteína NS1 de DENV2 para as duas principais populações de DCs no baço, na presença de diferentes agonistas. Poly I:C é capaz de induzir as respostas de Linfócitos T CD8+ mais robustas, mas somente quando o antígeno é direcionado para a população de DCs CD8+DEC205+. Com CpG observamos resposta de células T CD8+ equivalente quando a proteína foi direcionada para qualquer uma das populações estudadas. Direcionamento com Poly I:C gerou proteção contra desafio por DENV2 quando NS1 é direcionada para a população de DCs DEC205+, sendo esta proteção dependente de Linfócitos T CD8+ e CD4+. / Dendritic Cells are critical in the interaction between innate and the adaptive immune system, presenting antigens to T lymphocytes and inducing adaptive immune responses against these. DCs are target for development of new vaccine strategies based on targeting antigens to different DCs populations in vivo. This consists on the administration of antibodies specific to DC surface endocytic receptor fused to an antigen. In this study, we evaluated the differences in adaptive responses when the NS1 protein from the DENV2 was directed to the two main populations of DCs in the spleen along with different agonistic molecules. Highest CD8+ T cell responses were seen when Poly I:C was used, but only when directed to the CD8+DEC205+ DC population. In the presence of agonist CpG we observed similar responses when the protein was targeted to either CD8+DEC205+ or CD8-DCIR2+ DCs. In the presence of Poly I:C, only targeting to the DEC205+ DCs was able to protect mice against a challenge with DENV2. This protection was dependent on both CD8+ and CD4+ T cell responses.