Made available in DSpace on 2014-06-11T19:26:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-23Bitstream added on 2014-06-13T20:55:08Z : No. of bitstreams: 1 ferreira_ls_me_arafcf.pdf: 537259 bytes, checksum: 4756eac4f37ae0739a8b59e969ac32a1 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / A esporotricose é uma micose de distribuição universal cujo agente é o fungo termodimórfico Sporothrix schenckii. A forma mais comum da doença é a linfocutânea, que compromete pele, tecido subcutâneo e gânglios linfáticos regionais. Os principais constituintes da parede celular de S. schenckii são compostos peptídeo-polissacarídicos contendo ramnose, manose e galactose. Estes compostos se arranjam na parede celular de modo a formar duas subcamadas distintas na forma leveduriforme do fungo, uma das quais, a mais interna e fixa delas, é denominada como peptídeo-polissacarídeo da parede celular (PPC) e foi utilizada como antígeno neste estudo, juntamente com a levedura termo-inativada (SSTI). Os antígenos liberados pelo fungo participam diretamente do processo de escape do sistema imune e também servem como alvos para a eliminação do mesmo por anticorpos ou ligação a receptores presentes em células da imunidade inata, como os macrófagos. Nossos resultados mostraram que o PPC induz citocinas de padrão inflamatório de forma mais pronunciada que o SSTI, que por sua vez induziu maior liberação de IL-10. Sugerimos também que no modelo experimental utilizado a IL-10 não atua provocando supressão da resposta proliferativa dos esplenócitos, e que a IL-4 atua apenas na fase de resolução da infecção, não sendo induzida como forma de escape imunológico pelo fungo. Também mostramos que os antígenos testados são capazes de induzir a liberação de IL-17 em culturas de esplenócitos, num perfil semelhante àquela das citocinas Th1 / Sporotrichosis is a micotic infection of universal distribution, which is caused by dimorphic fungus Sporothrix schenckii. It usually happens as a lymphocutaneous disease, compromising skin, subcutaneous tissues and regional lymphatic nodules. Major constituents of S. schenckii cell wall are peptido-polysaccharide complexes containing rhamnose, mannose and galactose. These complexes are organized in two distinct layers in the fungus yeast cell wall, of which the inner one is called cell wall peptido-polysaccharide (PPC), being used as antigen in this study, along with the heat-killed yeast (SSTI). Antigens released by the fungus directly participate in evasion of the immune system, also serving as targets for fungus elimination by binding of antibodies or innate immune cells like macrophages. Our results showed that PPC induces inflammatory cytokines in a more pronounced way when compared to SSTI, which induced higher levels of IL-10. We also suggest that, in the animal model used, IL-10 doesn’t act as a suppressor of splenocyte proliferative response, and that IL-4 play a role at the resolution phase of the infection, being not induced as a means of immunologic escape by the fungus. Also, we showed that the assayed antigens are capable of inducing IL-17 secretion in splenocyte cultures, in a fashion close to that of Th1 cytokines

Orientador: Iracilda Zeppone Carlos / Banca: Angela Maria Victoriano de Campos Soares / Banca: Eduardo Bagagli / Resumo: A esporotricose é uma micose de distribuição universal cujo agente é o fungo termodimórfico Sporothrix schenckii. A forma mais comum da doença é a linfocutânea, que compromete pele, tecido subcutâneo e gânglios linfáticos regionais. Os principais constituintes da parede celular de S. schenckii são compostos peptídeo-polissacarídicos contendo ramnose, manose e galactose. Estes compostos se arranjam na parede celular de modo a formar duas subcamadas distintas na forma leveduriforme do fungo, uma das quais, a mais interna e fixa delas, é denominada como peptídeo-polissacarídeo da parede celular (PPC) e foi utilizada como antígeno neste estudo, juntamente com a levedura termo-inativada (SSTI). Os antígenos liberados pelo fungo participam diretamente do processo de escape do sistema imune e também servem como alvos para a eliminação do mesmo por anticorpos ou ligação a receptores presentes em células da imunidade inata, como os macrófagos. Nossos resultados mostraram que o PPC induz citocinas de padrão inflamatório de forma mais pronunciada que o SSTI, que por sua vez induziu maior liberação de IL-10. Sugerimos também que no modelo experimental utilizado a IL-10 não atua provocando supressão da resposta proliferativa dos esplenócitos, e que a IL-4 atua apenas na fase de resolução da infecção, não sendo induzida como forma de escape imunológico pelo fungo. Também mostramos que os antígenos testados são capazes de induzir a liberação de IL-17 em culturas de esplenócitos, num perfil semelhante àquela das citocinas Th1 / Abstract: Sporotrichosis is a micotic infection of universal distribution, which is caused by dimorphic fungus Sporothrix schenckii. It usually happens as a lymphocutaneous disease, compromising skin, subcutaneous tissues and regional lymphatic nodules. Major constituents of S. schenckii cell wall are peptido-polysaccharide complexes containing rhamnose, mannose and galactose. These complexes are organized in two distinct layers in the fungus yeast cell wall, of which the inner one is called cell wall peptido-polysaccharide (PPC), being used as antigen in this study, along with the heat-killed yeast (SSTI). Antigens released by the fungus directly participate in evasion of the immune system, also serving as targets for fungus elimination by binding of antibodies or innate immune cells like macrophages. Our results showed that PPC induces inflammatory cytokines in a more pronounced way when compared to SSTI, which induced higher levels of IL-10. We also suggest that, in the animal model used, IL-10 doesn't act as a suppressor of splenocyte proliferative response, and that IL-4 play a role at the resolution phase of the infection, being not induced as a means of immunologic escape by the fungus. Also, we showed that the assayed antigens are capable of inducing IL-17 secretion in splenocyte cultures, in a fashion close to that of Th1 cytokines / Mestre

Due to the intrauterine environment required to maintain pregnancy it may be that neonatal animals are born type-2 immune response (IR) biased, which consequently may increase susceptibility to certain infectious and immune mediated diseases, such as allergy. Recently, the prevalence of both allergic and autoimmune diseases has increased, leading to the development of the hygiene hypothesis. The hypothesis states that lack of early environmental stimulus leading to inappropriate development and bias in IR, may contribute to this increase. The objectives of this thesis, therefore, were to: (a) Determine the IR bias of neonatal pigs. (b) Investigate the effect of heat-killed Escherichia coli, lipopolysaccharide (LPS) and muramyl dipeptide (MDP) on the IR phenotype and the frequency of allergy in pigs sensitized to the egg white allergen ovomucoid (Ovm). (c) Establish IR phenotypes of pigs allergic or clinically tolerant to Ovm. Immune response bias was determined using an established phenotyping protocol and compared between two groups of pigs, (A) and (B). A difference in IR bias was observed. Bias in IR was not consistently towards type-2. Increase in indicators of type-1 IR, were greater in A and the frequency of type-2 IR correlates were greater in B. It’s likely that unidentified environmental variables may have induced this change, although etiology was not pursued. Treatment with heat-killed Escherichia coli, LPS and MDP had an effect on IR bias and frequency of allergy. Muramyl dipeptide-treatments promoted type-2 bias and were associated with increased frequency of allergy. Pre-treatment with E. coli did not affect allergic frequency, but did elicit the production of a relatively balanced allergen-specific IR phenotype. Lipopolysaccharide-pre-treatment was associated with decreased frequency of allergy. Correlates of an allergic IR phenotype in pigs were also established. The measurement of allergen-specific IgG, IgG1 and/or IgE activity and evaluation of late-phase intradermal skin tests were proposed to be useful in identifying allergic IR phenotypes. This thesis emphasizes the importance of considering the potential for variation in IR in terms of pig health and experimental reproducibility. Further, given the physiological similarities of pigs and humans, these findings may be extended to studies of food allergy in humans. / NSERC, OMAFRA, Ontario Pork, AllerGen NCE