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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Beta2-agonista como imunomodulador da resposta inflamatória pulmonar crônica induzida em camundongos sensibilizados com ovoalbumina / Beta2-agonist as immunomodulator of chronic lung inflammatory response induced in mice sensitized with ovalbumin

Kasahara, David Itiro 31 January 2005 (has links)
Estudamos o efeito do tratamento com salbutamol em dois regimes: diário (DS) e administrado a intervalos de 96 horas (IS) em camundongos balb/c sensibilizados com injeções intraperitoneais de uma solução de ovoalbumina (OVA) adsorvida em hidróxido de alumínio, e desafiada com inalações de ovoalbumina a 1%. O grupo controle SAL recebeu injeções i.p. de salina e desafios inalatórios de sallina. A partir do 34o dia, os animais OVA foram tratados com salbutamol via inalatória 10 mg/ml durante 15 minutos nos dois regimes descritos. Os animais foram sacrificados no 60o dia, que corresponde a 48 horas após o último desafio antigênico. Após os camundongos serem anestesiados com pentobarbital sódico via i.p., eles foram traqueostomizados e entubados e sacrificados com secção da Aorta abdominal. Então, procedeu-se com a coleta do lavado broncoalveolar para a quantificação de leucócitos. Coletamos os tecidos pulmonares para a avaliação do processo inflamatório por quantificação de células linfomononucleares (LMN) e eosinófilos EPO+, essa última com marcação citoquímica. Além disso, estudamos a influência do tratamento adrenérgico sobre o IgE anafilático. O modelo de inflamação (grupo OVA) produziu significativo aumento do número de células totais, de eosinófilos e de neutrófilos observados na avaliação de lavado broncoalveolar. Além disso, houve nesse grupo processo inflamatório na parede de vias aéreas, caracterizada por um infiltrado linfomononuclear e com presença de eosinófilos. O nosso processo de indução de inflamação também recrutou eosinófilos para o septo alveolar. O tratamento com salbutamol diário produziu uma queda significativa do processo inflamatório no BAL, principalmente de neutrófilos e eosinófilos, enquanto que o tratamento intermitente produziu redução significativa apenas de neutrófilos. O tratamento com salbutamol a cada 96 horas (IS) promoveu uma queda significativa de células LMN quantificadas no septo alveolar, mas não atingindo valores do grupo salina (NS). Ambos os tratamentos com salbutamol produziu redução significativa de células EPO+ no parênquima pulmonar (P < 0,05). Apesar das alterações no processo celular, o salbutamol não influenciou na expressão de anticorpos IgE anafiláticos a OVA. Assim, podemos concluir que o salbutamol apresenta atividade imunomoduladora, observada por redução de eosinófilos no BAL e no parênquima pulmonar, apesar de não atingir valores semelhantes aos animais do grupo salina / We studied the effects of salbutamol treatment in two regimen: diary (DS) and at interval of 96 hours (IS) in ovalbumin sensitized (OVA) balb/c mice. The control group (NS) received i.p. injections and aerosol challenge with normal saline. Starting at day 34 the OVA animals were treated with 10mg/ml salbutamol by inhalation during 15 minutes per day in both regimen: DS and IS. The mice were sacrificed at day 60 that corresponded the fourthly eight hours after last OVA and/or salbutamol exposure. At experimental day, mice were anesthetized with i.p. injection of sodium pentobarbital, tracheostomized, entubed and the abdominal aorta sectioned. We followed with collecting of bronchoalveolar lavage (BAL) and lungs to histopathology studies. In the BAL, total cells and differential leukocytes were quantified, while in the lung sections, the EPO+ and LMN in airways wall and parenchyma septa were evaluated. Also, we sampled the blood to evaluate the effects of salbutamol on anaphylactic IgE antibodies expression. The inflammatory model (OVA animals) produced a significant increase of BAL total cells, BAL eosinophils and neutrophils, and LMN cells and EPO+ eosinophils in the airways and in the parenchyma. Diary salbutamol treatment decrease significantly BAL eosinophils and neutrophils, while the IS group showed a diminution of BAL neutrophils and LMN cells in the alveolar septum. Both salbutamol treatments produced significant decline of EPO+ cells in the lung parenchyma. Despite the changes in the cellular patterns, the salbutamol did not affect the IgE antibodies expression. So, we can concluded that salbutamol present an immunomodulatory activity observed by reduction of eosinophils in the BAL and lung parenchyma, but did not achieve the values of saline control group
42

Transcriptional Regulation By Nuclear Receptor Homodimers Binding To The Direct Repeat Motif DR1 : Investigations In An in vitro Transcription System Derived From Rat Liver Nuclear Extracts

Harish, S 02 1900 (has links)
Nuclear receptors (NRs) are important transcription factors involved in the regulation of a variety of physiological processes such as embryonic development, cell differentiation and homeostasis (for review, see Mangelsdorf et al., 1995 TenBaum and Baniahrned, 1997). In contrast to membrane bound receptors, they bind small lipophilic ligands and function in the nucleus as ligand-modulated transcription factors. The ligands for nuclear receptors include steroids (glucocorticoids, progestins, mineralocorticoids, androgens and estrogens), vitamin D3, retinoids, thyroid hormone, prostaglandins, farnesoids etc. Several other nuclear receptors are classified as orphan receptors for which no ligand has yet been identified. More than 300 nuclear receptors have now been identified and together these proteins comprise the single largest family of metazoan transcription factors, the nuclear receptor superfamily. Recently, a unified nomenclature has been evolved (nuclear receptor nomenclature committee, 1999), a summary of which is presented in Table 1.
43

Does the Protein Aggregation State Affect the Digestibility and Safety of Foods?

Lassé, Moritz January 2013 (has links)
This thesis explores the complex relationship between food protein structure and digestibility. Food proteins are important nutrients that play a central role in controlling the textural properties of many foods. Processing of food proteins may alter the protein aggregate structure and digestibility. The degree of protein aggregation during food processing depends on the denaturing conditions and the presence of other food components. Sugars and lipids may contribute to protein glycation and protein cross-linking via the Maillard reaction. Furthermore, amino acid residues of food proteins may be chemically modified during processing, thereby influencing both the structure and the nutritional value of proteins. An in vitro digestibility assay was used to investigate the relationship between protein aggregate structure and protein digestibility. Raw and boiled egg whites were exposed to a wide range of conditions: pH 2 - 12, in the presence and absence of 200 mM NaCl. It was found that pH and NaCl treatment prior to in vitro digestion resulted in significantly different protein ultrastructures, but did not markedly influence protein digestibility under the tested conditions. Raw egg white was less digestible than boiled egg white under all test conditions. The inclusion of Maillard reaction partners caused protein cross-linking concurrent with a decrease in digestibility. The digestibility decreased with the reactivity of the Maillard reaction partner and with increasing heating time. Proteomic analysis, using tandem mass spectrometry, of raw and heated egg white showed an increase in hydrothermally induced amino acid modifications. In the presence of glucose and methylglyoxal, a Maillard reaction specific increase in arginine modification to hydroimidazolone was observed with increasing heating times. The observed modifications are likely to contribute to a change in the nutritional quality of egg white. Aggregation kinetics of the major egg white protein, ovalbumin, were studied by dynamic light scattering, small angle X-ray scattering, and transmission electron microscopy. Shape determination was only possible for ordered aggregates, but not for disordered aggregates. Prior to heating, ovalbumin molecules in the presence of water and glucose repelled each other in concentrated solution. The presence of NaCl shielded electrostatic repulsion, leading to early onset dimerisation and disordered aggregation upon heating. Methylglyoxal treated ovalbumin formed more ordered aggregates. The scattering of these structures was able to be fitted to cylindrical shape models showing an increase of cylinder length with time while the cylinder diameter remained near constant over 24 hours of heating. In addition, food protein derived amyloid fibril aggregates were characterised. Amyloid fibrils are a common ordered protein fold that has been linked to neurodegenerative diseases. In the recent literature, amyloid fibrils have been proposed as new functional macromolecules in proteinaceous foods because of their desirable textural properties. Food fibrils formed from whey, egg white, soy bean and kidney bean protein were tested to establish whether they are protease resistant or display toxicity to human Caco-2 cells (a model intestinal cell line). The food fibrils were compared to insulin amyloid fibrils, a well characterised amyloid system. It was shown that the food fibrils displayed some resistance towards in vitro hydrolysis and were not found to be toxic. This work contributes to the understanding of food protein aggregation and digestibility under relevant conditions. It highlights the relationship of aggregate structure and digestibility and the particular role of the Maillard reaction. Moreover, evidence is provided that food protein derived amyloid fibrils may be safe ingredients in consumables. These findings may contribute to optimising industrial food processes and creating safe new food products.
44

Pathways of paternal antigen presentation to initiate antigen-specific immune responses in pregnancy.

Moldenhauer, Lachlan January 2008 (has links)
The fetus and its placenta, collectively called the conceptus, are semi-allogeneic to the mother, as they express transplantation antigens of paternal origin. Foreign tissues generally experience immunological rejection by the host immune system; however in a normal healthy pregnancy the conceptus does not undergo immune attack. Emerging evidence indicates the conceptus avoids rejection through a number of mechanisms including the induction of active maternal immune tolerance specific for paternal antigens. However, the mechanisms responsible for establishing this tolerance remain undefined, including the timing of the first encounter with paternal antigen and the cellular processes by which paternal antigen is presented to the maternal immune system. Exposure to paternal transplantation antigens occurs in two waves: initially in the context of male seminal fluid at conception, and secondly after placental trophoblast invasion of maternal tissues in mid-gestation pregnancy. Therefore the aim of this research was to evaluate the female immune response to paternal antigens in seminal fluid and those associated with the conceptus. The mechanisms of antigen presentation, the impact of the cytokine environment and the consequences of T cell activation on pregnancy were also investigated. A transgenic system using ovalbumin (OVA) as the model paternal antigen was established. The transgenic Act-mOVA mouse expresses OVA constitutively and ubiquitously under a B-actin promoter and OVA was shown to be present in seminal fluid and in the fetal and placental tissue of sired progeny. The OVA-reactive CD8+ OT-I and CD4+ OT-II T cells were employed to gauge the relative amount of OVA antigen presented, with the strength of the maternal immune response quantified based upon the extent of T cell proliferation, as assessed by CFSE dye-dilution. Utilising bone marrow chimeric mice, it was demonstrated that upon insemination by an Act-mOVA male, seminal fluid-derived OVA was processed and indirectly presented by maternal bone marrow-derived antigen presenting cells to induce activation and proliferation of the CD8+ OT-I T cells within the uterinedraining para-aortic lymph nodes of the female. Likewise, OT-II T cells were responsive to MHC class II-restricted presentation of seminal fluid OVA. Post-implantation conceptus-derived OVA was detected within peripheral lymph nodes and the spleen where it was presented via the MHC class I and class II-restricted pathways to induce systemic proliferation of both OT-I and OT-II T cells. Furthermore, as gestation advanced the extent of OVA presentation and hence T cell proliferation intensified. Conceptus-derived OVA was still presented systemically until 20 days pp. The impact of the uterine cytokine environment was assessed to determine its influence on seminal OVA antigen processing and presentation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a key factor in regulating the leukocyte population of the female reproductive tract. GM-CSF-deficient female mice were unable to process and present seminal fluid OVA as effectively or efficiently as their wildtype counterparts, as assessed by their reduced capacity to drive OT-I and OT-II T cell proliferation following insemination by an Act-mOVA male. Finally, with highly-reactive OVA-specific T cells activated in response to seminal and conceptus OVA antigen, it was of interest to determine the effect of OT-I T cell activation on fetal survival and pregnancy success. It was found that OT-I T cells activated in vivo to paternal OVA antigen in the context of seminal fluid and pregnancy were not deleterious to pregnancy outcomes. However the transfer of cytotoxic OT-I T cells generated in vitro in the presence of an IL-2 into female mice carrying OVA-expressing conceptuses was detrimental to fetal survival. Collectively these experiments demonstrated that the initial exposure to paternal antigen, and hence the first opportunity to develop paternal antigen-specific tolerance, occurs at insemination. Paternal antigen is presented to the maternal T cell repertoire throughout gestation and may play a role in maintaining immune tolerance during pregnancy. The processing and presentation of paternal-derived antigen is chiefly performed by female bone marrow-derived antigen presenting cells. The cytokine environment of the mated female reproductive tract is critical in allowing optimal antigen processing and presentation, to generate an immune response consistent with maternal immune tolerance of the conceptus. / Thesis (Ph.D.) - University of Adelaide, School of Paediatrics and Reproductive Health, 2008
45

A modulação da resposta imune na colite experimental induzida por TNBS em camundongos da linhagem BALB/c: efeitos da tolerância oral e da transferência adotiva de células dendríticas CD11c+ / A modulation of the immune response in TNBS-induced experimental colitis in BALB/c mice: effects of oral tolerance and the adotive transfer of dendritic cells CD11c+

Paiatto, Lisiery Negrini [UNESP] 31 August 2017 (has links)
Submitted by LISIERY NEGRINI PAIATTO null (lisy_paiatto@hotmail.com) on 2017-10-23T19:38:26Z No. of bitstreams: 1 DISSERTAÇÃO LISIERY NEGRINI PAIATTO.pdf: 2873819 bytes, checksum: 5b03d17f06d1cc030a85241da7535ae7 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-10-26T12:04:52Z (GMT) No. of bitstreams: 1 paiatto_ln_me_rcla.pdf: 2873819 bytes, checksum: 5b03d17f06d1cc030a85241da7535ae7 (MD5) / Made available in DSpace on 2017-10-26T12:04:52Z (GMT). No. of bitstreams: 1 paiatto_ln_me_rcla.pdf: 2873819 bytes, checksum: 5b03d17f06d1cc030a85241da7535ae7 (MD5) Previous issue date: 2017-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A quebra da tolerância imunológica a antígenos próprios é um mecanismo gerador comum às respostas imunes deletérias. Várias estratégias têm sido propostas para modular respostas autoimunes, entre as quais se destacam a administração oral de antígenos relacionados à doença, a transferência adotiva de células tolerogênicas e/ou o tratamento com citocinas reguladoras. Nesse contexto, tem sido mostrado que a ingestão de antígenos proteicos presentes na dieta pode gerar efeitos indiretos sobre o sistema imune do hospedeiro, caracterizados pela supressão da resposta imune a proteínas antigenicamente não relacionadas, conhecidos como supressão bystander. O presente projeto teve por objetivo analisar os efeitos indiretos da tolerância oral induzida pela ingestão de ovalbumina (OVA) e a transferência adotiva de células dendríticas isoladas de animais tolerantes a OVA (tDC) na colite induzida por TNBS em camundongos. Os resultados mostraram que o tratamento de camundongos com OVA por via oral, antes ou após a indução da colite e a transferência adotiva de tDC, foram capazes de reduzir sinais da doença, tais como a perda de peso, bem como preservar parcialmente a integridade do tecido colônico, quando comparados aos animais colíticos não tratados com OVA (controles). A supressão bystander relacionada ao consumo de OVA foi associada à expansão da frequência de células T reguladoras (regs) e de células T secretoras de interleucina (IL) -10, possíveis mecanismos de regulação das manifestações clínicas da colite induzida por TNBS. As DC obtidas de animais tolerantes a OVA apresentaram expressão aumentada de CD80, compatível com perfil tolerogênico. A transferência dessa população de células para animais colíticos foi capaz de reduzir os sinais clínicos e histológicos da colite, mimetizando os efeitos da tolerância oral. A transferência adotiva de tDC levou a redução da frequência de células Th17, redução de secreção de IL-17 e IL-9 e aumento de secreção de IL-10 e IL-4 in vitro. Até onde é de nosso conhecimento, não existem dados na literatura mostrando o efeito da tolerância oral e a transferência adotiva de tDC no tratamento de colite. / The breakdown of immune tolerance to self antigens is a common mechanism for deleterious immune responses. Several interventions have been proposed to modulate autoimmune responses, such as oral administration of disease-related antigens, adoptive transfer of tolerogenic cells and/or treatment with regulatory cytokines. In this context, it has been demonstrated that the ingestion of protein antigens can generate indirect effects on the immune system of the host, characterized by suppression of the immune response to antigenically unrelated proteins, known as bystander suppression. The present project aims to analyze the indirect effects of oral tolerance induced by ovalbumin (OVA) and by adoptive transfer of tolerant dendritic cells (tDC) in TNBS induced colitis in mice. Our results showed that the treatment of oral OVA mice before or after induction of colitis and the adductive transfer of tDC were able to reduce the signs of the disease, such as weight loss, as well as partially preserve the integrity of the Compared to non-OVA treated animals (controls). The bystander suppression related to OVA consumption appears to favor the expansion of regulatory (regs) T and interleukin (IL)-10 secreting T cells responsible for reducing the clinical manifestations of TNBS-induced colitis. On the other hand, DC obtained from OVA-tolerant animals showed increased expression of CD80. Administration of this cells population to colitic animals was able to reduce the clinical and histological signs of colitis, possibly by reducing Th17 cells, reduction of secretion of Il-17 and IL-9 and augment of IL-10 and IL-4. To the best of our knowledge, there are no data in the literature showing the effect of oral tolerance and the adoptive transfer of tDC in the treatment of colitis. / FAPESP: 2013/20258-2
46

Tolerância cruzada no modelo de inflamação pulmonar alérgica experimental. / Cross-tolerance in a model of experimental allergic lung inflammation.

Bianca Balbino 02 December 2014 (has links)
A tolerância pode ser considerada um dos pilares da imunologia. Sabe-se que a tolerância a um antígeno pode gerar tolerância a outro antígeno não relacionado, fenômeno conhecido como tolerância cruzada. Neste trabalho caracterizamos a tolerância cruzada utilizando a OVA como tolerógeno e extrato de Blomia tropicalis (Bt) ou Hemocianina de Keyhole limpet (KLH) como alérgenos. Verificamos que é possível reproduzir o fenômeno da tolerância cruzada neste modelo de inflamação alérgica induzida tanto pelo KLH quanto pela Bt, com diminuição do infiltrado inflamatório no pulmão, eosinófilos, IgE total e produção de muco. Ainda, a estratégia de utilizar a tolerância cruzada terapeuticamente, i.é., após a sensibilização com KLH, a indução de tolerância cruzada não foi capaz de prevenir a resposta alérgica. Em conjunto, nossos dados mostram que a tolerância à OVA modifica as respostas alérgicas tanto à Bt quanto ao KLH no modelo de inflamação pulmonar experimental de forma profilática, mas que a tolerância cruzada não é eficiente em animais já sensibilizados. / Tolerance is among the Immunology pillars. Experimental data indicate that tolerance towards an antigen can promote tolerance to an unrelated antigen, a phenomenon known as cross-tolerance. Here we sought to characterize cross tolerance using OVA as a tolerogen and Blomia tropicalis (Bt) extract or Keyhole limpet Hemocianina (KLH) as allergens. We found that cross tolerance can be reproduced in the model of allergic lung disease induced by KLH or Bt, with less inflammatory infiltrate in the lung, eosinophils, total IgE and mucus production. Using cross tolerance therapeutically, i.e., after KLH sensitization, was not effective, since the allergic lung response was not modulated. Altogether, our data shows that OVA tolerance modulate allergic lung disease induced either by Bt or KLH when used as prophylactic model, however cross tolerance is ineffective in sensitized animals.
47

Beta2-agonista como imunomodulador da resposta inflamatória pulmonar crônica induzida em camundongos sensibilizados com ovoalbumina / Beta2-agonist as immunomodulator of chronic lung inflammatory response induced in mice sensitized with ovalbumin

David Itiro Kasahara 31 January 2005 (has links)
Estudamos o efeito do tratamento com salbutamol em dois regimes: diário (DS) e administrado a intervalos de 96 horas (IS) em camundongos balb/c sensibilizados com injeções intraperitoneais de uma solução de ovoalbumina (OVA) adsorvida em hidróxido de alumínio, e desafiada com inalações de ovoalbumina a 1%. O grupo controle SAL recebeu injeções i.p. de salina e desafios inalatórios de sallina. A partir do 34o dia, os animais OVA foram tratados com salbutamol via inalatória 10 mg/ml durante 15 minutos nos dois regimes descritos. Os animais foram sacrificados no 60o dia, que corresponde a 48 horas após o último desafio antigênico. Após os camundongos serem anestesiados com pentobarbital sódico via i.p., eles foram traqueostomizados e entubados e sacrificados com secção da Aorta abdominal. Então, procedeu-se com a coleta do lavado broncoalveolar para a quantificação de leucócitos. Coletamos os tecidos pulmonares para a avaliação do processo inflamatório por quantificação de células linfomononucleares (LMN) e eosinófilos EPO+, essa última com marcação citoquímica. Além disso, estudamos a influência do tratamento adrenérgico sobre o IgE anafilático. O modelo de inflamação (grupo OVA) produziu significativo aumento do número de células totais, de eosinófilos e de neutrófilos observados na avaliação de lavado broncoalveolar. Além disso, houve nesse grupo processo inflamatório na parede de vias aéreas, caracterizada por um infiltrado linfomononuclear e com presença de eosinófilos. O nosso processo de indução de inflamação também recrutou eosinófilos para o septo alveolar. O tratamento com salbutamol diário produziu uma queda significativa do processo inflamatório no BAL, principalmente de neutrófilos e eosinófilos, enquanto que o tratamento intermitente produziu redução significativa apenas de neutrófilos. O tratamento com salbutamol a cada 96 horas (IS) promoveu uma queda significativa de células LMN quantificadas no septo alveolar, mas não atingindo valores do grupo salina (NS). Ambos os tratamentos com salbutamol produziu redução significativa de células EPO+ no parênquima pulmonar (P < 0,05). Apesar das alterações no processo celular, o salbutamol não influenciou na expressão de anticorpos IgE anafiláticos a OVA. Assim, podemos concluir que o salbutamol apresenta atividade imunomoduladora, observada por redução de eosinófilos no BAL e no parênquima pulmonar, apesar de não atingir valores semelhantes aos animais do grupo salina / We studied the effects of salbutamol treatment in two regimen: diary (DS) and at interval of 96 hours (IS) in ovalbumin sensitized (OVA) balb/c mice. The control group (NS) received i.p. injections and aerosol challenge with normal saline. Starting at day 34 the OVA animals were treated with 10mg/ml salbutamol by inhalation during 15 minutes per day in both regimen: DS and IS. The mice were sacrificed at day 60 that corresponded the fourthly eight hours after last OVA and/or salbutamol exposure. At experimental day, mice were anesthetized with i.p. injection of sodium pentobarbital, tracheostomized, entubed and the abdominal aorta sectioned. We followed with collecting of bronchoalveolar lavage (BAL) and lungs to histopathology studies. In the BAL, total cells and differential leukocytes were quantified, while in the lung sections, the EPO+ and LMN in airways wall and parenchyma septa were evaluated. Also, we sampled the blood to evaluate the effects of salbutamol on anaphylactic IgE antibodies expression. The inflammatory model (OVA animals) produced a significant increase of BAL total cells, BAL eosinophils and neutrophils, and LMN cells and EPO+ eosinophils in the airways and in the parenchyma. Diary salbutamol treatment decrease significantly BAL eosinophils and neutrophils, while the IS group showed a diminution of BAL neutrophils and LMN cells in the alveolar septum. Both salbutamol treatments produced significant decline of EPO+ cells in the lung parenchyma. Despite the changes in the cellular patterns, the salbutamol did not affect the IgE antibodies expression. So, we can concluded that salbutamol present an immunomodulatory activity observed by reduction of eosinophils in the BAL and lung parenchyma, but did not achieve the values of saline control group
48

Estudo da mecânica oscilatória e do remodelamento de tecido pulmonar periférico em modelo de inflamação alérgica em cobaias: efeitos da inibição da óxido nítrico sintase induzida / Oscillatory mechanics and periphery lung tissue remodeling study in an allergic inflammation model in guinea pigs: effects of inducible nitric oxide synthase inhibition

Cláudia Miranda Starling 01 December 2008 (has links)
INTRODUÇÃO: A importância do parênquima pulmonar na piora funcional da asma tem sido recentemente investigada. Embora a ativação da enzima óxido nítrico sintase induzida (iNOS) amplifique a responsividade e o remodelamento das vias aéreas induzidos pela inflamação crônica, seu efeito no parênquima pulmonar não foi previamente estudado. OBJETIVO: Avaliar a influência do óxido nítrico derivado da iNOS na mecânica pulmonar, na inflamação e no processo de remodelamento no tecido pulmonar periférico de cobaias com inflamação pulmonar alérgica. MÉTODOS: Os animais foram submetidos a sete inalações com doses crescentes de ovalbumina (1~5 mg/mL) ou soro fisiológico por 4 semanas. As cobaias receberam 1400-W (inibidor específico de iNOS, intraperitoneal) ou veículo por 4 dias, iniciando 30 minutos antes da sétima inalação. Após 72h da sétima inalação, os animais foram anestesiados, exsanguinados e fatias de tecido pulmonar periférico foram retiradas e suspensas em banho orgânico de Krebs, e a resistência e elastância tecidual foram avaliadas em condição basal e após desafio com ovalbumina. Após, as fatias de tecido pulmonar periférico foram submetidas à avaliação histopatológica. RESULTADOS: Os animais expostos às inalações com ovalbumina apresentaram valores maiores de porcentagem de aumento da resistência e da elastância tecidual em relação ao basal após desafio com ovoalbumina no banho (p<0.05). Houve aumento no número de eosinófilos (p<0.001), nas células iNOS positivas (p<0.001), na deposição de fibras elásticas e colágenas (p<0.05), na densidade de actina (p<0.05) e na expressão de 8-epi-PGF2a (p<0.001) no septo alveolar. A administração de 1400-W reduziu todos estes parâmetros funcionais e morfológicos (p<0.05). CONCLUSÕES: Neste modelo experimental, o bloqueio específico da iNOS atenuou a constrição, a inflamação e o remodelamento no parênquima pulmonar. Estas alterações podem estar relacionadas aos efeitos do óxido nítrico na modulação da via do estresse oxidativo. O presente estudo sugere que a inibição específica da iNOS pode amplificar as estratégias terapêuticas utilizadas na abordagem de doenças inflamatórias crônicas pulmonares. / INTRODUCTION: The importance of lung parenchyma in functional asthma impairment has been recently addressed. Although the inducible nitric oxide synthase (iNOS) activation amplifies chronic inflammation-induced airway responsiveness and remodeling, its effect on lung parenchyma has not been previously investigated. OBJECTIVE: To evaluate the influence of iNOSderived NO in the pulmonary mechanics, inflammation, and remodeling processes in peripheral lung tissue of guinea pigs with pulmonary allergic inflammation. METHODS: Animals were submitted to seven ovalbumin exposures with increasing doses (1~5 mg/mL) or saline for 4 weeks. The guinea pigs received 1400-W (iNOS-specific inhibitor, intraperitoneal) or vehicle for 4 days, beginning 30 minutes before the 7th inhalation. At 72h after the 7th inhalation, animals were anesthetized, exsanguinated and peripheral lung tissue strips were retreat and suspended in a Krebs organ bath, and the tissue resistance and elastance were evaluated at baseline condition and after ovalbumin challenge. After that, strips were submitted to histopathological evaluation. RESULTS: The ovalbumin-exposed animals presented greater values of percentage of increase of tissue resistance and elastance related to baseline after ovalbumin challenge in the bath (p<0.05). There were increase in the number of eosinophils (p<0.001) and iNOSpositive cells (p<0.001), in collagen and elastic fiber deposition (p<0.05), in actin density (p<0.05) and in 8-epi-PGF2a expression (p<0.001) in the alveolar septa. The 1400-W administration reduced all these functional and morphological parameters (p<0.05). CONCLUSIONS: In this experimental model, the iNOS-specific blockage attenuated constriction, inflammation, and remodeling in the lung parenchyma. These alterations may be related to NO effects in the modulation of the oxidative stress pathway. The present study suggests that specific iNOS inhibition can amplify the therapeutics strategies used in the management in chronic inflammatory lung diseases.
49

Efeitos do ácido linoléico conjugado (CLA) cis-9 trans-11 na resposta imune à ovalbumina

Zidirich, Victor Eustáquio Tostes 18 March 2011 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-15T12:20:21Z No. of bitstreams: 1 victoreustaquiotosteszidirich.pdf: 1142000 bytes, checksum: 2b246de219ef265a66f3c21f0381b817 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-07-19T15:50:40Z (GMT) No. of bitstreams: 1 victoreustaquiotosteszidirich.pdf: 1142000 bytes, checksum: 2b246de219ef265a66f3c21f0381b817 (MD5) / Made available in DSpace on 2016-07-19T15:50:40Z (GMT). No. of bitstreams: 1 victoreustaquiotosteszidirich.pdf: 1142000 bytes, checksum: 2b246de219ef265a66f3c21f0381b817 (MD5) Previous issue date: 2011-03-18 / O ácido linoléico conjugado, do inglês “Conjugated Linoleic Acid” (CLA) é uma mistura de isômeros de posição e geométricos do ácido linoléico (C18:2 n-6), comumente encontrado em maiores concentrações na carne bovina e em produtos lácteos de ruminantes. Numerosas atividades biológicas têm sido atribuídas aos isômeros C18:2 cis-9, trans-11(c9t11) e ao C18:2 trans-10, cis-12 (t10c12) dentre as quais destacam-se: propriedades anticarcinogênica, antiaterogênica, antiobesogênica, incluindo aumento da massa magra em animais, retardo do aparecimento de diabetes tipo II e também nas respostas imunes humoral e celular. O presente trabalho focou na utilização do c9t11 na dieta em camundongos da linhagem BALB/c, avaliando efeitos na resposta imune humoral como a produção anticorpos específicos para ovalbumina (OVA), bem como a síntese de citocinas e respostas à hipersensibilidade tardia (HTT). O trabalho mostrou que o CLA na dieta reduziu efeitos nas respostas de HTT em 24 horas nos animais e estes apresentaram altos níveis de Ac anti- IgG1 e supressão no perfil Th1 de citocinas como IFN-γ e TNF-α. Com base nesses resultados foi possível perceber que o CLA foi um importante fator no controle do processo inflamatório do modelo e que seu uso poderia ser considerado como uma importante intervenção profilática para muitas doenças de natureza inflamatória. / Conjugated Linoleic Acid (CLA) is a mixture of positional and geometrical isomers of linoleic acid (C18:2 n-6), commonly found in high concentrations in bovine meat and lacteous products from ruminants. Numerous biological activities have been attributed to C18:2 cis-9, trans-11(c9t11) and C18:2 trans-10, cis-12 (t10c12) isomers, among which anti-carcinogenic, anti-aterogenic, anti-obesity properties must be highlighted, including increase of thin mass in animals, delay in type II diabetes emergence and also in humoral and cellular immune responses. This work focused on the use of c9t11 in the diet of BALB/c mice, evaluating effects on humoral immune response by means of production of ovalbumin (OVA) specific antibodies, cytokine production and responses to delayed type hypersensitivity (DTH). The results showed that using CLA in the diet of BALB/c mice decreased effects on DTH responses in a 24h period after animals had been challenged. They exhibited high levels of Ab anti-IgG1 and suppression of Th1 profile cytokines such as IFN-γ and TNF-α. Based on these results, it was possible to say that CLA was an important factor of control in the inflammatory process of the model and that its use could be considered as an important prophylactic intervention for many diseases of inflammatory nature.
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Characterization of the Mucosal and Systemic Immune Responses Following Virus Vector-Based Gene Delivery into the Colonic Mucosa

Safroneeva , Ekaterina January 2009 (has links)
While adenovirus (Ad) vectors have been shown to elicit potent antigen-specific T cell responses, the kinetics and nature of antigen-specific mucosa! and systemic T-cell responses has rarely been examined, especially following mucosal administration of Ad-based vectors. In the present studies, the phenotypic and functional characterization of antigen-specific CD8+ T cell responses following intrarectal (i.r.) vaccination with an Ad vector expressing Gallus gallus ovalbumin (OVA) was conducted. The frequencies of OVA-specific CD8+ T cells was maximal at 2 weeks post-vaccination in all tissues examined and then declined, demonstrating normal expansion and contraction kinetics. CD8+ T cells induced in the course of immunization exhibited phenotypic characteristics of effector memory T cells including up-regulation of the cell surface molecules CD43, CD44 and a low level of expression of CD127 at both local and systemic sites. While the discordance between the number of tetramer-reactive and cytokine-producing OVA-specific CD8+ T cells was observed, CD8+ T cells appeared to be fully functional in vivo. Upon secondary antigen exposure, the CD8+ T cell population expanded dramatically, particularly at the mucosa! surfaces. In addition, the CD8+ T cell response generated in the course of i.r. priming protected mice from intravaginal (i. vag.) vaccinia virus one month after immunization, thus underscoring the importance of inducing a tissue-resident effector memory T cell subset for protection against pathogens at mucosal surfaces. In developing future vaccines for mucosal diseases, the induction of a tissue-resident effector memory T cell subset should be one of the immunization objectives. Lentiviral vectors represent an attractive mode of genetic vaccination. Most commonly used, vesicular stomatitis virus glycoprotein (VSVG)-pseudotyped lentiviral vectors do not efficiently infect epithelial cells from the apical side, and, therefore, are not suitable as mucosa! vaccines. In the present studies, Ebola Zaïre strain glycoprotein (EboZ)-pseudotyped lentiviral vectors, which have been previously used to deliver transgene to the lung epithelium, were delivered i.r. and evaluated as a mucosal booster vaccine. Rectal delivery of EboZ-pseudotyped lentiviral vectors expressing β-galactosidase (β-gal) had resulted in low, but detectable levels of β-gal expression 2 weeks after administration. When delivered on its own, EboZ-pseudotyped lentivirus did not prime detectable antigen-specific immune response. However, when delivered i.r. 30 days after i.r. Adβ-gal immunization, a significant enlargement (boost) of β-gal-specific CD8+ T cell responses, especially in the colonic lamina propria (LP), was observed as compared to the delivery of EboZ-pseudotyped vector encoding different transgenes or VSVG-pseudotyped lentivirus expressing β-gal. When these animals were i. vag. challenged with vaccinia virus expressing β-gal, a dramatic expansion of β-gal-specific CD8+ T cells, especially in the vaginal tract, was observed. In addition, this prime and boost strategy protected the mice from i. vag. vaccinia virus challenge. Therefore, i.r. Ad-based priming followed by i.r. EboZ-pseudotyped lentiviral boosting was an effective strategy for eliciting protective mucosal CD8+ T cell responses. / Thesis / Doctor of Philosophy (PhD)

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