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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.
1

A sinalização via NOD2-RIP2 modula a imunidade adaptativa contra Leishmania infantum / NOD2-RIP2-mediated signaling contributes to shape adaptive immunity in visceral leishmaniasis

Nascimento, Manuela Sales Lima 04 April 2016 (has links)
Células produtoras de IFN-? e IL-17A são envolvidas na proteção contra infecção por Leishmania infantum (L. infantum). Ainda não está claro como o sistema imune coordena, ou o parasito manipula, o balanço entre Th1 e Th17 durante a leishmaniose visceral (LV). Utilizando RNAseq, PCR array e citometria de fluxo, nós demonstramos que, enquanto o padrão Th1 é altamente induzido, o perfil Th17 é inibido durante a infecção por L. infantum, e que as células B compõem uma fonte importante de IL-17A nesse modelo. Usando animais Nod2-/- e Rip2-/- nós caracterizamos essa via como um regulador negativo de células Th17 na LV. Por outro lado, a potente indução de Th1 foi dependente da sinalização via NOD2-RIP2 em células dendríticas CD8??+XCR1+, o que foi crucial para produção de IL-12 através da fosforilação de p38 e JNK. Como consequência, camundongos Nod2-/- e Rip2-/- tiveram defeito na resposta Th1, aumento de Th17, e maiores cargas parasitárias comparado com camundongos WT. Juntos, os dados mostram que a via de NOD2-RIP2 desempenha um papel importante na modulação da resposta imune adaptativa e promove proteção contra LV causada por L. infantum / IFN-? and IL-17A-producing cells are described to be related to protection against Leishmania infantum (L. infantum) infection. How the immune system coordinates, or the parasite manipulates, the balance between Th1 and Th17 during visceral leishmaniasis (VL) is still unknown. We showed here that Th17 is suppressed during L. infantum infection and B cells are an important source of IL-17A in this model. By using Nod2-/- and Rip2-/- mice we characterized this pathway as a negative regulator for Th17 cells in VL. On the other hand, the high level of Th1 induction was dependent on the NOD2-RIP2 signaling in CD8?+XCR1+ dendritic cells (DCs), which was crucial for IL-12 production through the phosphorylation of p38 and JNK. As a consequence, Nod2-/- and Rip2-/- mice showed a Th1 defective response, more Th17, and higher parasite loads compared to WT mice. Together, the data demonstrate that NOD2-RIP2 signaling pathway plays a role in shaping adaptive immunity and promotes protection against VL caused by L. infantum
2

Efeito imunomodulador e atividade antimicrobiana de heterofucanas de Sargassum filipendula

Telles, Cinthia Beatrice da Silva 26 June 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T20:01:31Z No. of bitstreams: 1 CinthiaBeatriceDaSilvaTelles_TESE.pdf: 1798517 bytes, checksum: 1ec7c34c6f828ce70bd877620c9ebb47 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-31T22:29:14Z (GMT) No. of bitstreams: 1 CinthiaBeatriceDaSilvaTelles_TESE.pdf: 1798517 bytes, checksum: 1ec7c34c6f828ce70bd877620c9ebb47 (MD5) / Made available in DSpace on 2016-05-31T22:29:14Z (GMT). No. of bitstreams: 1 CinthiaBeatriceDaSilvaTelles_TESE.pdf: 1798517 bytes, checksum: 1ec7c34c6f828ce70bd877620c9ebb47 (MD5) Previous issue date: 2015-06-26 / Macroalgas marinhas constituem uma fonte extremamente rica de compostos bioativos, dentre eles, polissacar?deos sulfatados. Sargassum filipendula (SF), alga pertencente ? ordem Phaeophycea, ? fonte de heterofucanas conhecidas pela capacidade de modular uma s?rie de fun??es biol?gicas. Considerando a necessidade de encontrar f?rmacos mais eficientes no combate a infec??es microbianas, as heterofucanas de SF foram avaliadas como agentes imunomoduladores e antimicrobianos. As heterofucanas SF0.5V, SF0.7V e SF1.0V apresentaram uma forte atividade imunomoduladora intensificando a libera??o de ?xido n?trico (NO) por macr?fagos murinos (RAW 264.7), bem como, por macr?fagos originados de mon?citos prim?rios humanos. Al?m disso, quando macr?fagos humanos foram infectados por Leishmania infantum e tratados com SF0.5V, SF0.7V e SF1.0V ocorreu um aumento significativo na libera??o extracelular de NO. Como a citotoxicidadede de macrof?gos contra a forma intracelular de leishmanias ? mediada pela produ??o de NO, avaliamos a atividade leishmanicida sobre a forma amastigota intracelular de L. infantum e observamos que macr?fagos infectados e tratados com SF0.5V, SF0.7V e SF1.0V se tornaram menos suscept?veis ? infec??o. As heterofucanas que se mostraram com capacidade de induzir a atividade anti-leishmania tamb?m apresentaram melhor taxa de produ??o de NO, por?m os dados de correla??o levaram a observa??o que este n?o ? o principal mecanismo de a??o das fucanas de SF no combate a esse protozo?rio. A heterofucana SF0.5V tamb?m apresentou atividade inibit?ria da forma??o de biofilme (~ 50%) frente a bact?ria Staphylococcus epidermidis. J? SF0.7V e 1.0V inibiram quase que totalmente a replica??o do protozo?rio Trichomonas vaginalis. Resultados como esse refletem o espectro de a??o desses polissacar?deos sulfatados obtidos de SF e mostram o seu potencial como agentes imunomoduladores e microbicidas. / Fucans, sulphated polysaccharides that contain L-fucose in its constitution, obtained from species of Phaeophyceae of the Sargassum kind, display several biological activities. Heterofucans from Sargassum filipendula are bioactive molecules that contain strong antiproliferative and antioxidant activity. However, their immunomodulatory and antimicrobial activities have not yet been examined. In this context, the aim of this research was to evaluate the heterofucans as for their immunomodulatory capacity and antimicrobial action against Leishmania infantum, Trichomonas vaginalis, Staphylococcus epidermidis and Klebsiella pneumonia (KPC). The five heterofucans obtained from S. filipendula show activities that are distant as stimulants of the immune system and microbial agent. The SF0.5V, SF0.7V amd SF1.0V heterofucans were capable of acting in the activation of murine and human macrophages. In addition to that, SF0.5V has shown antibiofilm activity of S. epidermides and SF0.7V and 1.0V almost completely inhibited the survival of the protozoan T. vaginalis. Results such as this one, reflect the broad range of action of the sulphated polysaccharides obtained from seaweeds, especially from the species S.filipendula
3

A sinalização via NOD2-RIP2 modula a imunidade adaptativa contra Leishmania infantum / NOD2-RIP2-mediated signaling contributes to shape adaptive immunity in visceral leishmaniasis

Manuela Sales Lima Nascimento 04 April 2016 (has links)
Células produtoras de IFN-? e IL-17A são envolvidas na proteção contra infecção por Leishmania infantum (L. infantum). Ainda não está claro como o sistema imune coordena, ou o parasito manipula, o balanço entre Th1 e Th17 durante a leishmaniose visceral (LV). Utilizando RNAseq, PCR array e citometria de fluxo, nós demonstramos que, enquanto o padrão Th1 é altamente induzido, o perfil Th17 é inibido durante a infecção por L. infantum, e que as células B compõem uma fonte importante de IL-17A nesse modelo. Usando animais Nod2-/- e Rip2-/- nós caracterizamos essa via como um regulador negativo de células Th17 na LV. Por outro lado, a potente indução de Th1 foi dependente da sinalização via NOD2-RIP2 em células dendríticas CD8??+XCR1+, o que foi crucial para produção de IL-12 através da fosforilação de p38 e JNK. Como consequência, camundongos Nod2-/- e Rip2-/- tiveram defeito na resposta Th1, aumento de Th17, e maiores cargas parasitárias comparado com camundongos WT. Juntos, os dados mostram que a via de NOD2-RIP2 desempenha um papel importante na modulação da resposta imune adaptativa e promove proteção contra LV causada por L. infantum / IFN-? and IL-17A-producing cells are described to be related to protection against Leishmania infantum (L. infantum) infection. How the immune system coordinates, or the parasite manipulates, the balance between Th1 and Th17 during visceral leishmaniasis (VL) is still unknown. We showed here that Th17 is suppressed during L. infantum infection and B cells are an important source of IL-17A in this model. By using Nod2-/- and Rip2-/- mice we characterized this pathway as a negative regulator for Th17 cells in VL. On the other hand, the high level of Th1 induction was dependent on the NOD2-RIP2 signaling in CD8?+XCR1+ dendritic cells (DCs), which was crucial for IL-12 production through the phosphorylation of p38 and JNK. As a consequence, Nod2-/- and Rip2-/- mice showed a Th1 defective response, more Th17, and higher parasite loads compared to WT mice. Together, the data demonstrate that NOD2-RIP2 signaling pathway plays a role in shaping adaptive immunity and promotes protection against VL caused by L. infantum
4

Entwicklung von Mikrosatellitenmarkern für populationsgenetische Untersuchungen bei Leishmania infantum

Hertweck, Sebastian 20 January 2005 (has links)
Leishmania infantum ist für einen beträchtlichen Teil der viszeralen Leishmaniosen weltweit verantwortlich. Die allgemein anerkannte Methode zu Klassifizierung wie auch zur Identifizierung von Leishmanien ist die Isoenzymanalyse. Speziell für L. infantum reicht das Auflösungsvermögen dieser Methodik allerdings nicht aus, da mehr als 80 % der analysierten Stämme dem prädominanten Zymodem MON-1 angehören. In dieser Arbeit wurden Primerpaare für die Amplifikation von 15 unabhängigen Mikrosatelliten entwickelt. Das verwendete Protokoll zur Erstellung einer angereicherten genetischen Bibliothek ist leicht für andere Leishmanienspezies adaptierbar. Die Marker wurden an 13 Stämmen des L. donovani-Komplexes getestet mit Schwerpunkt auf L. infantum MON-1. Die berechneten Dendrogramme entsprachen weitestgehend den Ergebnissen früherer, auf genotypischen Methoden basierenden phylogenetischen Studien. In Abhängigkeit von Zymodem und Spezies wurden unterschiedlich hohe Anteile heterogener Allele beobachtet. Das ist der erste Satz von unabhängigen Mikrosatellitenmarkern entwickelt speziell für L. infantum, der groß genug für phylogenetische Anwendungen ist. Für jedem untersuchten Stamm wurde ein eigener Multilocus-Genotyp beobachtet, was diese Methode zu einem wichtigen Werkzeug für epidemiologische und populationsgenetische Untersuchungen macht. / Leishmania infantum is responsible for a large proportion of visceral leishmaniasis all over the world. The universally accepted standard method for characterizing and identification of Leishmania is the isoenzyme analysis. Especially for L. infantum, this procedure lacks of discriminative power because the predominant zymodeme MON-1 is represented by more than 80 % of the analysed isolates. In this study, PCR assays amplifying 15 independent microsatellites were developed using a method to create highly enriched libraries that can easily be adapted for other species of Leishmania. The panel of markers was tested for 13 strains of the L. donovani complex with main emphasis on L. infantum MON-1. The calculated dendrograms corresponded to the results of former phylogenetic investigations based on genotypic methods. Depending of zymodeme and species, different degrees of allelic heterozygosity were observed. This is the first set of independent microsatellite markers especially developed for L. infantum, which is large enough for phylogenetic applications. An unique multi locus genotype is produced for each analysed isolate what makes this approach to a powerful tool for epidemiological and population genetic investigations.

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