Submitted by Maike Costa (maiksebas@gmail.com) on 2017-09-06T13:04:43Z No. of bitstreams: 1 arquivoptotal.pdf: 2877352 bytes, checksum: 9e31e912377c0a68df303843bc0368bc (MD5) / Made available in DSpace on 2017-09-06T13:04:43Z (GMT). No. of bitstreams: 1 arquivoptotal.pdf: 2877352 bytes, checksum: 9e31e912377c0a68df303843bc0368bc (MD5) Previous issue date: 2016-08-12 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Inflammatory Bowel Disease (IBD) is characterized as an uncontrolled chronic inflammation of the intestinal mucosa and mainly includes two pathologies: Crohn's disease and ulcerative colitis. Accordingly, the local immune system remains compromised and the intestine intensely inflamed, due to an inability of decreasing inflammatory responses. Complementary and alternative medicines have been of great interest for the treatment of IBD, with the aim to improve the side effects of commonly used drugs. Goat whey present oligosaccharides and conjugated linoleic acid with different functional properties, but also an effect on intestinal incipient modulation. This thesis was divided into two studies: the first being goat whey ability in preventing intestinal inflammation in an inflammation model induced by acetic acid in rats, evaluated by comparing it with a standard sulfasalazine medicine used in the treatment of DII; in the second study, the anti-inflammatory effect of the whey colitis model induced by 2,4-dinitrobenzenesulfonic acid in mice. In the first, the pre-treatment with goat whey (1, 2 and 4 g. Kg-1) and sulfasalazine (250 mg. Kg-1) improved the inflammatory markers (myeloperoxidase, leukotriene B4 and pro-inflammatory cytokines) and oxidative stress (total content of glutathione and malondialdehyde) in colonic tissue of rats. Histological and immunohistochemical evaluation of colonic tissue showed cytoarchitecture preservation and reduction in COX-2 expression, respectively, as well as iNOS and MMP-9 in conjunction with an increase in SOCs-1 expression. The results suggest that goat whey exerted a preventive effect against intestinal damage induced by acetic acid, showing similar efficacy to sulfasalazine, and thus is a potential treatment for human inflammatory bowel disease. In the second model, we used the best dose of the first to conduct different analyses. In the second model with a different inducing agent of IBD was used to dose goat whey that Showed better results in improving of intestinal inflammation the previous study. This study, there was also an improvement of intestinal damage in the group of animals, confirmed by evaluating colonic inflammation and colonic gene expression of pro-inflammatory markers IL-6, IL-1β, IL-17,TNF-α, iNOS, ICAM- 1, MMP-9, regulators of intestinal epithelial integrity (MUC-2, MUC-3, occludin and ZO-1) and supressor of cytokine signaling (SOCS-1). The anti-inflammatory properties of the goat whey were demonstrated by an in vitro study on murine macrofhages line Raw 264 and CMT-93 cells derived from murine rectum carcinoma which promoted a significant reduction in nitric oxide production and IL-6. Thus, goat whey shown as an innovative product in the prevention and control of intestinal inflammation in murine models. / A Doença Inflamatória Intestinal (DII), caracterizada por apresentar uma inflamação crônica não controlada na mucosa intestinal, engloba, principalmente, duas patologias: a Colite Ulcerativa e a Doença de Crohn. Nestas, o sistema imunológico local permanece cronicamente ativado e o intestino intensamente inflamado, devido a uma incapacidade do organismo para a diminuição das respostas inflamatórias. Terapias alternativas e complementares tem sido de grande interesse para o tratamento das DII, com o objetivo de melhorar os efeitos secundários dos fármacos comumente utilizados. O soro de leite caprino apresenta na sua composição oligossacarídeos e ácido linoleico conjugado com propriedades funcionais, mas ainda insipiente como efeito na modulação intestinal. A presente tese foi dividida em dois estudos: no primeiro, foi avaliada a capacidade do soro de leite de cabra em prevenir a inflamação intestinal no modelo de inflamação induzida por ácido acético em ratos, comparando com um fármaco padrão, a sulfassalazina utilizada no tratamento da DII; no segundo, foi estudado o efeito anti-inflamatório do soro de leite no modelo de colite induzido por ácido 2,4-dinitrobenzeno sulfônico em camundongos. O pré-tratamento com soro de leite caprino (1, 2 e 4 g. Kg-1) e sulfassalazina (250 mg. Kg-1) melhorou os marcadores inflamatórios (mieloperoxidase, leucotrieno B4 e citocinas pró-inflamatórias) e de estresse oxidativo (conteúdo total de glutationa e malondialdeido) no tecido colônico dos animais. A avaliação histológica e imunohistoquímica do tecido colônico revelaram, respectivamente, uma preservação da citoarquitetura e redução na expressão de COX-2, iNOS e MMP-9, em conjunto com um aumento da expressão de SOCs-1. Os resultados sugerem que o soro caprino exerceu um efeito preventivo contra o dano intestinal induzida por ácido acético, mostrando uma eficácia semelhante à mostrada por sulfassalazina, sendo, portanto, um potencial tratamento para a doença inflamatória intestinal humana. No segundo modelo, com diferente agente indutor da DII, utilizou-se a dose de soro de leite caprino que mostrou melhor resultado na melhora da inflamação do estudo anterior. Neste estudo, também houve uma melhora do dano intestinal no grupo dos animais, confirmado pela avaliação do processo inflamatório colônico, e expressão gênica do cólon dos marcadores pró-inflamatórios IL-6, IL-1β, IL-17, TNF-α, iNOS, ICAM- 1, MMP-9, reguladores da integridade intestinal epitelial (MUC-2 e MUC-3, ocludina e ZO-1) e supressor de sinalização de citocinas (SOCS-1). As propriedades anti-inflamatórias do soro foram evidenciadas no estudo in vitro em células Raw 264 de macrófagos de murinos e CMT-93 derivada de células de carcinoma retal de murinos, em que promoveu uma redução significativa da produção de óxido nítrico e IL-6. Dessa forma, o soro de leite caprino, mostra-se como um produto inovador na prevenção e controle inflamação intestinal em modelos murinos.

O trato gastrointestinal é um sítio de alta exposição antigênica, por isso requer a presença de mecanismos de regulação imunológica mediada por linfócitos T reguladores e T auxiliares produtores de IL-17 (Th17) na mucosa intestinal. Se houvera falha na indução desses mecanismos, pode ocorrer o desequilíbrio das populações de bactérias comensais da microbiota intestinal, denominado de disbiose, geralmente associado à ruptura da barreira intestinal e translocação de bactérias ou LPS para o sangue. Neste sentido, alguns estudos têm evidenciado a importância dos linfócitos Th17 no intestino, já que estas células tem a capacidade de manter a integridade da barreira intestinal e, como conseqüência controlar a colonização e translocação bacteriana. Em adição, em pacientes e animais diabéticos têm sido observada a correlação de altos níveis de LPS circulantes e resistência à insulina. Baseado nessas evidências, nosso objetivo foi avaliar o papel da citocina IL-17 no controle das alterações inflamatórias e metabólicas no modelo de diabetes do tipo 2 (DM2). Para isso, foram utilizados camundongos C57BL/6 selvagens (WT) ou deficientes do receptor da citocina IL-17 (IL-17R-/-) submetidos à dieta controle (DN), composta por 10% de gorduras, 70% de carboidratos e 20% de proteínas ou à dieta hiperlipídica (DH), composta por 60% de gorduras, 20% de carboidratos e 20% de proteínas. Nossos dados demonstraram que a deficiência do receptor de IL-17 protegeu os animais contra a obesidade, mas os mesmos desenvolveram maior hiperglicemia e hiperinsulinemia decorrente da resistência à insulina. Além disso, foi verificada a hiperplasia das ilhotas pancreáticas, anormalidades na arquitetura e intenso infiltrado inflamatório no intestino (íleo) dos animais IL-17R-/- comparados aos WT após DH. Esse fato parece estar correlacionado a um defeito da migração de neutrófilos para a mucosa intestinal, uma vez que foi detectada reduzida expressão gênica da quimiocina CXCL-1 e do receptor CXCR-2 no íleo desses animais. De maneira interessante, as populações de neutrófilos (CD11b+Ly6G+) e de macrófagos anti-inflamatórios (CD11b+CX3CR1+) mostraram-se aumentadas nos linfonodos mesentéricos dos animais IL-17R-/- após DH. Em seguida, foi constatada maior translocação bacteriana no sangue tanto de animais IL-17R-/- submetidos à DN como DH. Entretanto, a análise metagenômica do gene 16S revelou a prevalência de bactérias Bacteroidetes e Proteobacterias, principais representantes de bactérias gram-negativas, somente nas fezes dos animais IL-17R-/- submetidos à DH. Em conjunto, estes dados indicam que o eixo IL-17/IL-17R é importante na manutenção da homeostase intestinal e na regulação das alterações inflamatórias e metabólicas associadas ao DM2 / The gastrointestinal tract is a high antigenic exposure site, so it requires the presence of immune regulation mechanisms mediated by regulatory T lymphocytes and IL-17- producing T helper lymphocytes (Th17) in the intestinal mucosa. If there is a failure in the induction of these mechanisms, may occur the imbalance in the populations of commensal bacteria of the intestinal microbiota, called dysbiosis, generally associated with the break of the intestinal barrier and translocation of bacteria or their products like LPS into the blood. In this regard, some studies have evidenced the importance of Th17 lymphocytes in the intestine, since these cells have the ability to maintain the integrity of the intestinal barrier, and consequently controlling the colonization and bacterial translocation. In addition, in patients and diabetic animals have been observed correlation between high circulating levels of LPS and insulin resistance. Based on this evidence, our objective was to evaluate the role of IL-17 cytokine in the control of inflammatory and metabolic changes in the type 2 diabetes (T2DM). For this reason, were used C57BL/6 wild-type mice (WT) or lacking of IL-17 cytokine receptor (IL-17R-/-) mice undergoing to the control diet (ND) comprising 10% fat, 70% carbohydrate and 20% protein or high fat diet (DH), comprising 60% fat, 20% carbohydrates and 20% protein. These data demonstrate that IL-17 receptor deficiency protected the animals against obesity, but these mice developed hyperglycemia and hyperinsulinemia due to insulin resistance. Furthermore, we verified a hyperplasia of the pancreatic islets, abnormalities in architecture and intense inflammation in the intestine (ileum) of IL-17R-/- animals undergoing DH compared to WT. This appears to be correlated to a defect in the neutrophil migration to the intestinal mucosa, since was detected reduced gene expression of the CXCL-1 chemokine and CXCR-2 receptor in the ileum of these animals. Interestingly, the populations of neutrophils (CD11b+Ly6G+) and antiinflammatory macrophages (CD11b+CX3CR1+) were shown to be increased in the mesenteric lymph nodes of IL-17R-/- animals after DH. Later, it was found more bacterial translocation in blood, both in IL-17R-/- mice with ND or DH. However, the metagenomic analyzes of the 16S gene revealed increased of Proteobacteria and Bacteroidetes phyla, the main representatives of gram-negative bacteria, only in the faeces of IL-17R-/- mice underwent DH. Together, these data indicate that IL-17/IL-17R axis is important in maintaining intestinal homeostasis and the regulation of inflammatory and metabolic alterations associated to T2DM

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Campylobacter jejuni e Campylobacter coli sÃo importantes agentes etiolÃgicos de doenÃa diarrÃica na populaÃÃo mundial. A infecÃÃo por Campylobacter sp. à usualmente identificada por cultivo microbiolÃgico que leva aproximadamente 72 horas para identificaÃÃo do gÃnero. Nosso objetivo principal foi pesquisar a prevalÃncia de C. jejuni e C. coli em populaÃÃo infantil, com idade entre 2-36 meses, da Ãrea urbana de Fortaleza/CE, Brasil, em estudo do tipo epidemiolÃgico observacional caso-controle, utilizando, como ferramenta de detecÃÃo, a reaÃÃo em cadeia da polimerase (PCR). Outros objetivos consistiram em: investigar o impacto nutricional da infecÃÃo (casos) ou da colonizaÃÃo (controles) por Campylobacter sp.; determinar a presenÃa de trÃs genes de virulÃncia para a toxina citoletal distensora (CDT) de C. jejuni e avaliar a ocorrÃncia de inflamaÃÃo intestinal nas infecÃÃes causadas por Campylobacter sp. A populaÃÃo estudada consistiu de 83 casos e 83 controles, sendo os casos, crianÃas com histÃrico de diarrÃia nos 14 dias pregressos à seleÃÃo para o estudo. Foram avaliados parÃmetros sÃcio-econÃmicos atravÃs de questionÃrio epidemiolÃgico. Medidas antropomÃtricas foram coletadas para determinaÃÃo de escores-z no intuito de avaliar o perfil nutricional das crianÃas. A detecÃÃo de Campylobacter nas amostras congeladas foi realizada por ensaio imuno-enzimÃtico (ELISA) e PCR. Pela PCR tambÃm investigamos a presenÃa dos genes cdtA, cdtB e cdtC da CDT de C. jejuni. A avaliaÃÃo da inflamaÃÃo intestinal foi realizada pela pesquisa de lactoferrina fecal (LFF), atravÃs de ELISA semiquantitativa. Foi detectado, por PCR, C. jejuni em 9,6% dos casos (8/83) e 7,2% dos controles (6/83). C. coli foi detectado em 6,0% dos casos (5/83) e 1,2% dos controles (1/83). Os genes cdtA, cdtB e cdtC foram encontrados em 50% das amostras hipO+ (7/14). Houve diferenÃa significativa (p<0,05) dos escores WAZ e WHZ entre casos e controles portadores de C. jejuni, sendo que casos portadores apresentaram mÃdia inferior de WAZ e WHZ, quando comparados com os controles portadores. No grupo Casos, os portadores de C. jejuni apresentavam valor mÃdio de WHZ inferior ao valor mÃdio apresentado pelos casos nÃo-portadores. Mais de 80,0% das crianÃas estudadas apresentaram inflamaÃÃo intestinal caracterizada por elevados nÃveis de LFF, independente da presenÃa de diarrÃia e Campylobacter sp. Em conclusÃo, nossos achados corroboram dados da literatura cientÃfica relacionados à prevalÃncia de C. jejuni e C. coli na populaÃÃo infantil, existÃncia de portadores assintomÃticos e associaÃÃo entre a detecÃÃo do microorganismo e desnutriÃÃo. AlÃm disso, nossos dados apontam para ocorrÃncia de variabilidade genÃtica dentre as cepas de C. jejuni detectadas na populaÃÃo estudada em relaÃÃo à presenÃa ou ausÃncia dos genes de CDT. / Campylobacter jejuni and Campylobacter coli are important etiologic agents of worldwide diarrheal disease. Campylobacter sp. infection is usually identified by a 72 hour microbiological culture that identifies the genus of the responsible organism. Our main goal was to investigate the prevalence of C. jejuni and C. coli in children, aged 2-36 months, from urban Fortaleza, CE, Brazil, in an observational epidemiological case-control study using, as a tool of detection, the polymerase chain reaction (PCR). Our other goals were to investigate the nutritional impact of infection (cases) or colonization (controls) for Campylobacter sp., to determine the presence of three virulence genes of C. jejuni cytolethal distending toxin (CDT), and to evaluate the occurrence of inflammation in intestinal infections caused by Campylobacter sp. The study population consisted of 83 cases and 83 controls, where the cases consisted of children with a history of diarrhea in the 14 days prior to selection for the study. We assessed socioeconomic parameters through an epidemiological questionnaire. Anthropometric measurements were collected to determine z-score parameters for assessing the nutritional status of the children. Detection of Campylobacter from frozen samples was performed by enzyme-linked immunosorbent assay (ELISA) and PCR. Also, using PCR technology, we investigated the presence of C. jejuni genes cdtA, cdtB and cdtC. Intestinal inflammation was assessed by semi-quantitative ELISA detection of fecal lactoferrin (LFF). PCR technology detected C. jejuni in 9.6% of the cases (8/83) and 7.2% of the controls (6/83), while C. coli was detected in 6.0% of the cases (5/83) and 1.2% of the controls (1/83). CDT genes were found in 50% of hipO+ samples (7/14). There was a significant difference (p <0.05) in the weight for age z-scores (WAZ) and the weight for height z-scores (WHZ) between case and control carriers of C. jejuni, where case carriers showed lower average WAZ and WHZ than control carriers. Moreover, in the case group, carriers of C. jejuni showed a lower WHZ average than that of non-carrier cases of C. jejuni. More than 80.0% of the children studied had intestinal inflammation characterized by high levels of LFF regardless of the presence of diarrhea and Campylobacter sp. In conclusion, our findings corroborate data in the scientific literature related to the prevalence of C. jejuni and C. coli in pediatric populations, the existence of asymptomatic carriers and an association between the detection of the microorganism and malnutrition. In addition, our data suggest a genetic variability among the strains of C. jejuni detected in the study population, related to presence o absence of CDT genes.

Contexte : La malnutrition aiguë sévère (MAS) est un problème majeur de santé publique dans lemonde et affecte 17 millions d’enfants âgés de moins de 5 ans. La MAS induit une perte de poidsrapide, souvent associée à une dysfonction entérique environnementale (DEE). La DEE se caractérisepar une augmentation de l’inflammation, de la perméabilité intestinale, une diminution de la taille des villosités et de l’absorption des nutriments. La DEE peut ainsi limiter l’efficacité des protocolesde stabilisation et de re-nutrition chez l’enfant dénutri.L’objectif de cette thèse a été de développer un modèle de dénutrition avec entéropathie pour évaluer des laits thérapeutiques enrichis en nutriments ciblant la fonction de barrière intestinale.Résultats : Lors de la phase de développement du modèle, plusieurs approches ont été testées comme la restriction calorique, le régime hypoprotéiné, l’utilisation de lipopolysaccharides et de l’indométacine. Seule la combinaison d’un gavage quotidien d’indométacine pendant une semaine chez des souris dénutries par un régime pauvre en protéines a permis de développer un retard de croissance associé à une entéropathie. Suite à la validation de ce modèle, nous avons évalué la supplémentation du lait thérapeutique F-75 avec de la glutamine, de la leucine, de la gomme arabique et des levures séléniées. La glutamine et la leucine améliorent la fonction de barrière intestinale. Dans nos conditions expérimentales, l’enrichissement du lait thérapeutique avec la glutamine et la leucine combinés a eu des effets limités sur la fonction de barrière. La gomme arabique et les levures séléniées ont des propriétés prébiotiques et probiotiques et exercent des effets bénéfiques sur la barrière intestinale. L’enrichissement du lait thérapeutique avec l’association de ces deux composés permet d’inhiber l’inflammation intestinale et d’augmenter l’abondance de bactéries bénéfiques comme Faecalibacterium prausnitzii.Conclusion : Les travaux réalisés au cours de cette thèse ont permis de développer un nouveau modèle de dénutrition avec entéropathie. Le lait thérapeutique enrichi en gomme arabique et levures séléniées exerce des effets bénéfiques sur la fonction de barrière intestinale dans notre modèle. / Background : Severe acute malnutrition (SAM) is a global health issue affecting 17 million children under the age of 5. SAM induces rapid weight loss and is often associated with environmental enteric dysfunction (EED). EED is characterized by intestinal hyperpermeability and inflammation, villus blunting and nutrient malabsorption. EED might, therefore, limit stabilization and re-nutrition protocol efficacy. Objectives : This thesis aimed to develop an undernutrition model with enteropathy to evaluate the effect of a therapeutic milk enriched with nutrients on gut barrier function. Results : During preclinical model development, several approaches were tested: calorie restriction, low-protein diet, use of lipopolysaccharides and indomethacin. Only daily indomethacin gavage during one week in protein-energy undernourished mice induced growth faltering associated with enteropathy. After preclinical model validation, we evaluated the effect of therapeutic milk supplemented with glutamine, leucine, gum arabic and/or selenium-enriched yeast on gut barrier function. Glutamine and leucine induce beneficial effects on gut barrier function. In ourexperimental conditions, therapeutic milk enriched with a combination of glutamine and leucine had a limited impact on this parameter. Gum arabic and selenium-enriched yeasts have prebiotic and probiotic properties on gut barrier function. Therapeutic milk supplemented with gum arabic and selenium-enriched yeast inhibited intestinal inflammation and enhanced specific bacteria abundance such as Faecalibacterium prausnitzii.Conclusion : The studies conducted during this thesis permitted to develop a new model of undernutrition with enteropathy. Therapeutic milk enriched with arabic gum and selenium-enriched yeast triggered beneficial effects on gut barrier function in our preclinical model.

<p>Intestinal microbiota are key determinants of gut homeostasis and affect various gut physiological and immune processes. Co-evolution has enabled the host and intestinal microbes to exist in a mutualistic relationship. However, interactions between the host and its intestinal microbiota exist in a delicate balance between mutualism and pathogenicity. Maintenance or disruption of this balance depends on a complex interplay between the microbiota and the host, as well as other gut luminal factors, including diet, that are poorly understood. The main goal of this thesis has been to study the host-gut luminal interactions that regulate gut physiology and immunity. In particular, <strong>Chapter 2</strong> centers on investigating the effect of perturbing the intestinal barrier using a non-steroidal inflammatory drug on host-microbial and dietary interactions in a mouse model of gluten sensitivity. I demonstrated that indomethacin-induced increase in intestinal permeability is associated with altered intestinal microbiota composition, systemic antibody development against intestinal bacteria and a shift in immune responses to the dietary antigen, gluten. <strong>Chapter 3</strong> focuses on investigating whether modulation of the intestinal microbiota can affect the host’s susceptibility to intestinal injury. I used mice with defective intracellular bacterial receptor signaling because discrimination between commensals and pathogens is, in part, achieved by a family of receptors that recognize conserved bacterial components. I demonstrated that the microbiota with which these mice are colonized influences the expression of RegIII-γ, a type of antimicrobial peptide, and susceptibility to intestinal injury. To gain further insight on the effect of microbiota on antimicrobial peptides, in <strong>Chapter 4</strong> we conducted a combination of gnotobiotic and <em>in-vitro</em> experiments where we identified that specific components of the microbiota differentially regulate RegIII expression. Further examination showed that <em>MyD88 a</em>nd <em>Ticam1 </em>genes, which are signaling adaptor proteins of pattern recognition receptors, are essential regulators of microbial–induced RegIII expression by intestinal epithelial cells. Collectively, the work presented in this thesis provides novel insight on the bi-directional interaction between the host and the gut luminal content as well as of potential beneficial effects of microbiota-modulating strategies in maintaining homeostasis and preventing disease.</p> / Doctor of Philosophy (Medical Science)

T-Helfer-9-(Th9-)Zellen produzieren große Mengen Interleukin-(IL-)9 und lösen bei Wurm- und Tumorerkrankungen protektive Immunantworten aus. Sie sind aber auch maßgeblich an der Pathogenese chronisch entzündlicher Darmerkrankungen beteiligt. Im Widerspruch zu diesen entzündungsauslösenden Eigenschaften steht ihre Rolle bei der Erzeugung von Toleranz gegenüber allogenen Transplantaten. Diese gegensätzlichen inflammatorischen Eigenschaften deuten eine bisher nicht untersuchte funktionelle Heterogenität an. In vitro-differenzierte allo-reaktive Th9-Zellen zeigten sich in ihrer Gesamtheit pro-inflammatorisch. Dies äußerte sich nach Transfer in recombination activating gene-defiziente (Rag-/-) Mäuse durch einen akut einsetzenden Gewichtsverlust mit intestinaler Entzündung und durch die Abstoßung allogener Hauttransplantate. Mittels Einzelzell-Genexpressionsanalyse wurden zwei Th9-Subpopulationen identifiziert, die sich vor allem in ihrer CD96-Expression unterschieden (CD96low versus CD96high Th9-Zellen). Die differenzielle Expression von CD96 spiegelte sich auch im inflammatorischen Potenzial der Zellen wider. Während der Transfer von CD96low Th9-Zellen in Rag-/- Mäuse einen Gewichtsverlust mit Darmentzündung sowie die Transplantatzerstörung verursachte, zeigten CD96high-rekonstituierte Tiere kaum Entzündungsanzeichen im Transplantat bzw. im Darm. Dementsprechend verloren sie auch kein Gewicht. Es zeigte sich, dass CD96low Th9-Zellen ein höheres Potenzial zur Produktion von IL-4 und IL-9 sowie zur Expansion besaßen als CD96high Th9-Zellen. Eine Blockade von CD96 in vivo stellte die inflammatorischen Eigenschaften von CD96high Th9-Zellen wieder her, wodurch die funktionelle Relevanz der CD96-Expression unterstrichen wurde. Diese Daten belegen, dass es sich bei Th9-Zellen um eine funktionell heterogene Zellpopulation handelt. Weiterhin zeigen sie, dass CD96 – ein Molekül mit bislang unklarer Funktion in CD4+ T-Zellen – die Aktivität von Th9-Zellen negativ beeinflusst. / T helper 9 (Th9) cells are potent producers of interleukin(IL-)9 driving host immunity against worm infections and tumors. Furthermore, they are predominantly involved in the pathogenesis of chronic inflammatory bowel diseases. However, they also induce tolerance in allogeneic transplantation, which contrasts with their pro-inflammatory properties. These observations indicate a functional heterogeneity of Th9 cells not examined so far. Total in vitro differentiated allo-reactive Th9 cells injected into recombination activating gene-deficient (Rag-/-) mice caused weight loss, intestinal inflammation and rejection of allogenic skin grafts which proofed their inflammatory character. However, using single cell profiling, two subsets of Th9 cells mainly differing in their CD96 expression were identified (CD96low versus CD96high Th9 cells). Transfer of CD96low Th9 cells into Rag-/- mice induced severe weight loss, intestinal inflammation and graft destruction. In contrast, transfer of CD96high Th9 cells did cause neither weight loss nor resulted in graft rejection. Transcriptional profiling revealed a higher IL-9 and IL-4 expression potential as well as an increased expansion capacity in CD96low Th9 cells compared to CD96high Th9 cells. Blockade of CD96 in vivo restored the inflammatory properties of CD96high Th9 cells demonstrating, that expression of CD96 controls effector functions in Th9 cells. Thus, Th9 cells are heterogeneous in function. Moreover, this study suggests an inhibitory role for the co-signaling receptor CD96 – a molecule with so far unknown function in CD4+ T cells – in Th9 cells.

This thesis investigates how air pollution, both natural and anthropogenic, affects changes in the proximal small intestine and ileum microbiota profile, as well as intestinal barrier integrity, histological changes, and inflammation. APO-E KO mice on a high fat diet were randomly selected to be exposed by whole body inhalation to either wood smoke (WS) or mixed vehicular exhaust (MVE), with filtered air (FA) acting as the control. Intestinal integrity and histology were assessed by observing expression of well- known structural components tight junction proteins (TJPs), matrix metallopeptidase-9 (MMP-9), and gel-forming mucin (MUC2), as well known inflammatory related factors: TNF-α, IL-1β, and toll-like receptor (TLR)-4. Bacterial profiling was done using DNA analysis of microbiota within the ileum, utilizing 16S metagenomics sequencing (Illumina miSeq) technique. Overall results of this experiment suggest that air pollution, both anthropogenic and natural, cause a breach in the intestinal barrier with an increase in inflammatory factors and a decrease in beneficial bacteria. This evidence suggests the possibility of air pollution being a potential causative agent of intestinal disease as well as a possible contributing mechanism for induction of systemic inflammation.