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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.
21

Health research with Manitoba First Nations. An investigation of gene variants affecting the Th17 immune pathway and the P2RX7 receptor.

Semple, Catlin 21 September 2016 (has links)
Introduction: Canadian First Nations experience a significantly higher rate of Mycobacterium tuberculosis (MTB) infection than non-Indigenous Canadians. Th17 cells are a subset of CD4+ T cells that are distinguished by their production of Interleukin-17A (IL-17A), an important cytokine for defense against mycobacteria. IL-17 is a primary contributor to the formation and stabilization of the lung granuloma, a biological containment vessel to protect the host from tuberculosis (TB). Past research with First Nations people has identified single nucleotide polymorphisms (SNPs) in the Th1 and Th2 immune pathways may affect their disease risk. However, SNPs in key Th17 related genes and the P2RX7 gene have not been explored in First Nations despite their important role against infectious diseases. Hypothesis: This research hypothesizes that distinct First Nations groups (Dene, Cree and Saulteaux) will have a different frequencies of SNPs in the key Th17 immunity related genes (IL-17A, IL-17AR, IL-23R, and IFN-γR) and the P2RX7 gene, as compared to a non-Indigenous Canadian group. Methods: SNP profiles (IL-17A rs2275913, IL-17RA rs4819554, IL-23R rs10889677, IFN-γR rs2234711 and P2RX7 rs3751143) were identified through literature research and the NCBI database was used for identifying gene motifs, primer locations and Restriction Enzyme cut sites. Polymerase Chain Reaction and Restriction Fragment Length Polymorphism analysis was performed on and visualized on agarose gel to determine specific allele frequencies. Four different Manitoba First Nations communities; the Northern Dene (Dene 1 N=69. Dene 2 N=52), Central Cree (N=46), and Southern Saulteaux (N=56), participated in this research and their SNP profiles were compared to a non-Indigenous Canadian cohort (N=99). Results: Allele frequencies for IL-17A were statistically different for every First Nation community when compared to the non-Indigenous cohort (Dene 1 p=0.0043, Dene 2 p=0.0000, Cree p=0.0001, Saulteaux p=0.0000). Allele frequencies for IL-17RA were statistically different for every First Nation community except Saulteaux when compared to the non-Indigenous cohort (Dene 1 p=0.0000, Dene 2 p=0.0028, Cree p=0.0000). Allele frequencies for IL-23R were statistically different for Dene 1 and Saulteaux community when compared to the non-Indigenous cohort (Dene 1 p=0.0002, Saulteaux p=0.0000). Allele frequencies for IFN-R were statistically different for Cree community when compared to the non-Indigenous cohort (Cree p=0.0026). Allele frequencies for P2RX7 were statistically different for both Dene communities when compared to the non-Indigenous cohort (Dene 1 p=0.0000, Dene 2 p=0.0000). Conclusions: An effective Th17 response is required to bring Th1 cells to infected tissues and to balance inflammatory responses. Functional SNPs may compromise an appropriate immune response and contribute to disease. This study demonstrate that the non-Indigenous population maintained a significantly different genetic profile when compared to the First Nations populations. / October 2016
22

Bioactive leishmanicidal alkaloid molecules from Galipea longiflora Krause with immunomodulatory activity

Calla-Magariños, Jacqueline January 2012 (has links)
According to WHO, leishmaniasis is endemic in 98 countries, and has been placed ninth in a global analysis of infectious diseases. Treatment of leishmaniasis is based on pentavalent antimonials but toxicity and developing resistance have been reported. Traditional medicine and scientific studies have shown that the extract of Galipea longiflora Krause (Evanta) exhibits antileishmanial activity. We hypothesized that the healing observed when using this plant might not only be due to the direct action on the parasite, but possibly to a parallel effect on the host immune response. We found that an alkaloid extract of Evanta (AEE) inhibited the growth of Leishmania braziliensis promastigotes while viability of eukaryotic cells was practically not affected. We also found that AEE interfered with polyclonal activation or Leishmania-specific re-stimulation of lymphocytes, as revealed by a reduction of in vitro cellular proliferation and IFN-g production. More important, AEE treatment of mice hosting L. braziliensis showed that AEE is able to control both inflammation and parasite load. Additionally, the healing process was improved when AEE and meglumine antimoniate were administered simultaneously. Dendritic cells (DCs) play a pivotal role in T-cell stimulation and polarization of naïve T cells. Therefore, we investigated if AEE could alter the activation of DCs and if allostimulatory DCs properties were altered if activated in the presence of AEE. DCs activated in the presence of AEE reduced the production of IL-12p40 and IL-23. When we analyzed the allostimulatory capacity of AEE-treated DCs, we found that allogeneic CD4+ T-cells secreted lower levels of IFN-γ. In conclusion, this thesis provides valuable insight into the effects of Evanta derived extract. The dual effect found for AEE, on Leishmania parasite and on the immune response, suggests that AEE may be useful in controlling the parasite burden and preventing over-production of inflammatory mediators and subsequently avoiding tissue damage. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Accepted. Paper 3: Submitted.</p>
23

Nouveaux phénotypes immunologiques et cliniques liés au déficit de la chaîne IL-12Rβ1

Ganne De Beaucoudrey, Ludovic 17 November 2008 (has links) (PDF)
L'axe IL-12-IFN-γ joue un rôle important dans l'immunité anti-mycobactérienne. J'ai identifié et étudié une cohorte de 137 patients présentant un déficit autosomique récessif complet d'IL12RB1 qui code la sous-unité β1 des récepteurs de l'IL-12 et de l'IL-23. Ces patients sont issus de 101 familles provenant de 30 pays. Ils présentent une grande diversité génétique avec 52 allèles mutants différents. Le phénotype cellulaire avec un défaut complet de réponse à l'IL-12 est homogène chez tous les patients. Les phénotypes cliniques sont eux très hétérogènes allant de l'absence d'infection jusqu'au décès. Il s'agit en grande majorité d'infections mycobactériennes (BCG, mycobactéries environnementales et tuberculose) et/ou à salmonelles. La candidose est aussi retrouvée associée à ce défaut chez un grand nombre de patients. L'axe IL-23-IL-17 participe à la différentiation et à l'activation des lymphocytes T CD4+ dits de type Th17. les cytokines et les mécanismes contrôlant la différentiation de ces cellules sont peu connus. J'ai étudié le développement des lymphocytes producteurs d'IL-17 chez des patients porteurs de défauts génétiques affectant la voie du TGF-β (patients TGFBR1, TGFBR2 et TGFB1), de l'IL-1β (patients IRAK4 et MYD88), de l'IL-6 (patients STAT3) et de l'IL-23 (patients IL12B et IL12RB1). Pour cela, j'ai quantifié la production et la sécrétion d'IL-17 dans deux modèles expérimentaux ex vivo et in vitro. Les patients IL12B-/- et IL12RB1-/-, et de façon plus drastique les patients STAT3-/- présentent une diminution des lymphocytes producteurs d'IL-17, ce qui suggère l'importance de ces molécules dans la différentiation et l'expansion des cellules Th17 in vivo
24

Interferon-γ promotes inflammation and development of T-cell lymphoma in HTLV-1 bZIP factor transgenic mice / インターフェロンγはHBZトランスジェニックマウスの炎症とTリンパ腫の発症を促進する

Mitagami, Yu 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第19628号 / 医科博第66号 / 新制||医科||5(附属図書館) / 32664 / 京都大学大学院医学研究科医科学専攻 / (主査)教授 髙折 晃史, 教授 浅野 雅秀, 教授 小柳 義夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
25

Rescue of host innate immunity in pigs infected with Nsp1ß mutant PRRSV

Shyu, Duan-Liang 14 October 2015 (has links)
No description available.
26

Interactions cellules NK – Cellules Dendritiques : importance de la coopération entre TLR3 et les Hélicases RLR dans l’initiation d'une réponse innée antivirale / NK cell – dendritic cell cross-talk : cooperation between TLR3 and RLR for the initiation of a potent innate antiviral response

Perrot, Ivan 30 September 2009 (has links)
Diverses études ont souligné le rôle prépondérant du dialogue entre les cellules NK et les cellules dendritiques au cours des réponses immunes. Cependant, les récepteurs impliqués dans ce processus restent incertains. Au cours de ce travail, nous nous sommes attachés à identifier les récepteurs mis en jeu lors de la reconnaissance virale à l’aide de modèles humains et murins. Pour cela, nous avons mimé l’infection virale en utilisant deux ARN bicaténaires synthétiques – poly(AU) et poly(IC) – et montré qu’ils sont tous deux capables d’activer TLR3 mais que seul poly(IC) engage les hélicases RIG-I et MDA5. Les deux ARN induisent l’activation des cellules NK au sein des PBMC humaines, mais seul poly(IC) induit la production d’IFN-gamma. Les DC myéloïdes (mDC) sont requises pour cette activation sans nécessité d’un contact cellulaire entre les cellules NK et les mDC. En outre, les IFN de type I et l’IL-12 secrétés par les DC sont respectivement nécessaires à l’initiation du potentiel lytique et à la production d’IFN-gamma. Poly(IC), au contraire de poly(AU), a une action synergique avec l’IL-12 produite par les mDC pour induire la production d’IFN-gamma en agissant directement sur les cellules NK. Enfin, l’activation conjointe de TLR3 et des hélicases RLR sur les mDC et RIG-I sur les cellules NK, nécessaire à la production d’IFN-gama en réponse à l’ARN bicaténaire, a été confirmée à l’aide de souris déficientes pour TLR3 et Cardif et d’un ligand spécifique de RIG-I. En conclusion, nous rapportons pour la première fois la nécessité pour un composé microbien d’engager deux familles de récepteurs sur deux populations cellulaires distinctes pour induire une réponse innée éfficace. / Crosstalk between NK cells and DC is critical for the response to the microbial mimic poly(IC) but the dsRNA receptors involved in each cell types remained to be defined. We show herein that two dsRNA, poly(AU) and poly(IC), similarly engaged TLR3 while only poly(IC) triggered the RIG-I and MDA-5 helicases. Both dsRNA triggered NK cell activation within PBMC but only poly(IC) induced IFN-gamma. mDC were required for NK cell activation by the two dsRNA, suggesting that they triggered at least TLR3 on mDC. DsRNA induction of cytolytic potential and IFN-gamma production in NK cells did not require contact with mDC but was dependent on the secretion of type I IFN and IL-12, respectively. Poly(IC) but not poly(AU) synergized with mDC-derived IL-12 for high IFN-gamma production by acting directly on NK cells. Finally, the requirement of TLR3 and the RLR on mDC and the involvement of the RIG-I but not TLR3 on NK cells for the production of IFN-gamma induced by dsRNA was confirmed using TLR3 and Cardif deficient mice and RIG-I specific activator. This cooperation was further confirmed using inactivated FLU virus infected-target cells both in human and mouse system demonstrating that NK cells were able to sense viral material by a direct transfer from infected cells likely through lytic immunological synapse without prior infection of NK cells. Thus, we report for the first time the requirement of cotriggering
27

Charakterizace vedlejší populace buněčné linie TRAMP-C2, myšího modelu karcinomu prostaty" / Characterisation of the cell line TRAMP-C2 side population, mouse model of prostate cancer

Žlabová, Anna January 2012 (has links)
Side population is a minor subpopulation (SP) of some cell lines, exporting staining dye Hoechst 33342 out of their cytoplasm. It is discussed as a possible source of "cancer stem cells", "tumour initiating cells" or "metastasis initiating cells". However, broad literature suggest, that stemness and other privileged properties of SP are very variable between different cell types, cell lines and stage of disease. Cell lines TRAMP are the only widely available murine models for testing of prostate cancer therapy. We noticed in literature a mention about existence of 1-2% of cells constituting side population, but detailed characteristic have not been described until now. In this diploma thesis, we worked on characterisation of SP of the TRAMP-C2 cell line in comparison to other cells (nonSP). In the first part, we compared stem properties of SP and nonSP. We started with checking the existence of SP by its verapamil sensitivity. Using mRNA analysis, we showed that neither SP nor nonSP have increased c-Kit expression and that there are no differences in Bmi-1 expression. We found that SP is heterogenic mixture of CD24-CD44-, CD24-CD44+ and CD24+CD44+ cells, while nonSP is almost solely CD24-CD44+. We documented that SP and nonSP returned back to original SP ratio during cultivation. Then we showed on...
28

Efeito do IFN-k e TNF-&alpha; sobre a expressão gênica de CYBB e processamento de seus transcritos. / The effect of IFN-g and TNF-&alpha; on CYBB gene expression and its transcripts processing.

Frazão, Josias Brito 19 March 2014 (has links)
O sistema NADPH oxidase humano é responsável pela geração de reativos intermediários do oxigênio e defeitos neste sistema resultam na Doença Granulomatosa Crônica (DGC). Nesta tese de doutorado, investigamos o efeito do IFN-g sobre eventos pós-transcricionais em pacientes com DGC ligada ao X, ocasionada por defeitos de splicing. Os dados obtidos sugerem que o uso do IFN-g in vitro interfere no processamento da mensagem causando aumento da expressão de transcritos do gene CYBB e NCF1 em células B-EBV de indivíduos sadios e pacientes DGC analisados. Observamos também que o IFN-g dimunui a expressão dos genes THOC4 NONO, SF3A1, SRRM1 e UPF3A e promove aumento de expressão de SRSF10, SNRPA1 e C2 em células B-EBV de paciente X-DGC secundária a defeitos de splicing. Identificamos que o IFN-g e o TNF-&alpha; aumentam a expressão das proteínas envolvidas no processo do splicing. Concluímos que o IFN-g aumenta a expressão de genes importantes para uma resposta eficiente do sistema imunológico, incluindo os do sistema NADPH oxidase, além de promover aumento da expressão de genes e de proteínas relacionados ao processo de splicing, que podem estar relacionados aos efeitos benéficos observados no uso do IFN-g em pacientes com DGC ligada ao X, ocasionada por defeitos de splicing. / The human phagocyte NADPH oxidase is responsible for the generation of reactive oxygen intermediates and defects in this system result in Chronic Granulomatous Disease (CGD). In this PhD Thesis, we investigated the effect of IFN-g on post-transcriptional events in normal individuals and patients with X-linked CGD, caused by splicing defects. The obtained data suggests that the use of IFN-g in vitro interferes in the message processing causing an increase of expression of CYBB and NCF1 gene transcripts in B-EBV cells of healthy individuals and analyzed CGD patients. We also observed that IFN-g decreases the expression of THOC4, NONO, SF3A1, SRRM1 and UPF3A, and increases the expression of SRSF10, SNRPA1 and C2 genes in cells from X-CGD patients, due to splicing defects. We identified that IFN-g and TNF-&alpha; induce expression of proteins involved in the splicing process. We conclude that IFN-g increases the expression of important genes for an effective immune response, including the NADPH oxidase system genes, and promotes augment of gene and protein expression related to the splicing process, which may be related to the beneficial effects related to the use of IFN-g in CGD patient caused by splicing defects.
29

Polimorfismo da interleucina-18 e do interferon gama na síndrome da lipodistrofia associada à terapia anti-retroviral em portadores do HIV-1 / Polymorphism of the interleukin-18 and interferon-gamma in antiretroviral-associated lipodystrophy syndrome in HIV-1-infected patients.

Castelar, Luciana 20 February 2009 (has links)
A introdução da terapia anti-retroviral de alta potência no tratamento da infecção pelo HIV reduziu significativamente as taxas de morbi-mortalidades relacionadas à imunodeficiência. Entretanto, o tratamento medicamentoso é acompanhado de vários efeitos colaterais, dentre eles, a síndrome da lipodistrofia (SL), caracterizada por alterações morfológicas e metabólicas. Apesar de sua patogenia não estar totalmente esclarecida, é sabido que aumento dos níveis de algumas citocinas inflamatórias estão relacionados com o desenvolvimento da SL. Diversos sítios polimórficos têm sido descritos por influenciarem a transcrição de genes, levando a variações nos níveis de produção de citocinas, como os da região promotora da interleucina-18 (IL-18 -607 C/A e IL-18 -137 C/G) e do gene do interferon gama (IFN- +874 T/A). Diante disso, esse estudo tipificou os polimorfismos da IL-18 e do IFN- em 88 pacientes portadores do HIV com a SL, em 79 portadores do HIV sem a SL, todos sob terapia anti-retroviral e em 133 indivíduos saudáveis, por meio da técnica de reação em cadeia da polimerase com iniciadores de seqüência específica. Este estudo foi aprovado pelo Comitê de Ética em Pesquisa. A presença do alelo -607A e do genótipo -607AA na IL-18 estava significativamente aumentada nos pacientes portadores do HIV com SL quando comparados aos sem a SL, conferindo susceptibilidade ao desenvolvimento da síndrome. De maneira oposta, o alelo -607C e o genótipo -607CC estavam significativamente aumentados em pacientes portadores do HIV sem SL quando comparados aos com a SL, conferindo proteção ao desenvolvimento da síndrome. Os haplótipos -137G/-607A and -137C/-607A, que comportam o alelo -607A, também estavam associados com a susceptibilidade à SL e o haplótipo -137G/-607C estava fortemente associado com proteção contra a SL. Nenhuma diferença significativa na distribuição alélica e genotípica da IL-18 -137 e do IFN- +874 foram observadas entre os grupos de pacientes e o grupo controle. Este é o primeiro estudo que avaliou o polimorfismo da IL-18 e do IFN- na SL e os resultados sugerem que a região promotora da IL-18 está associada com o desenvolvimento da SL em pacientes portadores do HIV. / The introduction of highly active antiretroviral therapy in the treatment of HIV infection significantly reduced the rates of morbidity and mortality related to immunodeficiency. However, the drug treatment is accompanied by various side effects, including the lipodystrophy syndrome (LD), characterized by morphological and metabolic changes. Although its pathogenesis is not totally clear, it is known that increased levels of some inflammatory cytokines are related to the development of LD. Several polymorphic sites have been described by influencing transcription of genes, leading the variations in the levels of cytokine production, such as the promoter region of interleukin-18 (IL-18 -607 C/A and IL-18 -137 C/G) and the interferon gamma gene (IFN- +874 T/A). Thus, this study typifies the polymorphism of the IL-18 and IFN- in 88 HIV-infected patients with LD, in 79 HIV-infected patients without LD, all under antiretroviral therapy and in 133 healthy controls, using the sequence-specific primers-polymerase chain reaction. This study was approved by the Ethics Committee at the place of study. The presence of -607A allele and -607AA genotype in IL-18 gene were significantly increased in HIV patients presenting LD as compared with HIV patients without LD, resulting in susceptibility to the development of LD. Conversely, the -607C allele and -607CC genotype were significantly increased in HIV patients without LD as compared with the HIV patients with LD, offering protection against LD. Haplotypes -137G/-607A and -137C/-607A, carrying the -607A allele, were also associated with susceptibility to LD. The haplotype -137G/-607C was strongly associated with protection against LD. No significant differences in IL-18 -137 and IFN- +874 genotype and allele distribution were observed in patients when compared to a control group. This is the first study evaluating the IL-18 and IFN- polymorphisms in LD and the results suggest that the promoter region of the IL-18 gene is associated with LD development in HIV-infected patients.
30

Polimorfismo da interleucina-18 e do interferon gama na síndrome da lipodistrofia associada à terapia anti-retroviral em portadores do HIV-1 / Polymorphism of the interleukin-18 and interferon-gamma in antiretroviral-associated lipodystrophy syndrome in HIV-1-infected patients.

Luciana Castelar 20 February 2009 (has links)
A introdução da terapia anti-retroviral de alta potência no tratamento da infecção pelo HIV reduziu significativamente as taxas de morbi-mortalidades relacionadas à imunodeficiência. Entretanto, o tratamento medicamentoso é acompanhado de vários efeitos colaterais, dentre eles, a síndrome da lipodistrofia (SL), caracterizada por alterações morfológicas e metabólicas. Apesar de sua patogenia não estar totalmente esclarecida, é sabido que aumento dos níveis de algumas citocinas inflamatórias estão relacionados com o desenvolvimento da SL. Diversos sítios polimórficos têm sido descritos por influenciarem a transcrição de genes, levando a variações nos níveis de produção de citocinas, como os da região promotora da interleucina-18 (IL-18 -607 C/A e IL-18 -137 C/G) e do gene do interferon gama (IFN- +874 T/A). Diante disso, esse estudo tipificou os polimorfismos da IL-18 e do IFN- em 88 pacientes portadores do HIV com a SL, em 79 portadores do HIV sem a SL, todos sob terapia anti-retroviral e em 133 indivíduos saudáveis, por meio da técnica de reação em cadeia da polimerase com iniciadores de seqüência específica. Este estudo foi aprovado pelo Comitê de Ética em Pesquisa. A presença do alelo -607A e do genótipo -607AA na IL-18 estava significativamente aumentada nos pacientes portadores do HIV com SL quando comparados aos sem a SL, conferindo susceptibilidade ao desenvolvimento da síndrome. De maneira oposta, o alelo -607C e o genótipo -607CC estavam significativamente aumentados em pacientes portadores do HIV sem SL quando comparados aos com a SL, conferindo proteção ao desenvolvimento da síndrome. Os haplótipos -137G/-607A and -137C/-607A, que comportam o alelo -607A, também estavam associados com a susceptibilidade à SL e o haplótipo -137G/-607C estava fortemente associado com proteção contra a SL. Nenhuma diferença significativa na distribuição alélica e genotípica da IL-18 -137 e do IFN- +874 foram observadas entre os grupos de pacientes e o grupo controle. Este é o primeiro estudo que avaliou o polimorfismo da IL-18 e do IFN- na SL e os resultados sugerem que a região promotora da IL-18 está associada com o desenvolvimento da SL em pacientes portadores do HIV. / The introduction of highly active antiretroviral therapy in the treatment of HIV infection significantly reduced the rates of morbidity and mortality related to immunodeficiency. However, the drug treatment is accompanied by various side effects, including the lipodystrophy syndrome (LD), characterized by morphological and metabolic changes. Although its pathogenesis is not totally clear, it is known that increased levels of some inflammatory cytokines are related to the development of LD. Several polymorphic sites have been described by influencing transcription of genes, leading the variations in the levels of cytokine production, such as the promoter region of interleukin-18 (IL-18 -607 C/A and IL-18 -137 C/G) and the interferon gamma gene (IFN- +874 T/A). Thus, this study typifies the polymorphism of the IL-18 and IFN- in 88 HIV-infected patients with LD, in 79 HIV-infected patients without LD, all under antiretroviral therapy and in 133 healthy controls, using the sequence-specific primers-polymerase chain reaction. This study was approved by the Ethics Committee at the place of study. The presence of -607A allele and -607AA genotype in IL-18 gene were significantly increased in HIV patients presenting LD as compared with HIV patients without LD, resulting in susceptibility to the development of LD. Conversely, the -607C allele and -607CC genotype were significantly increased in HIV patients without LD as compared with the HIV patients with LD, offering protection against LD. Haplotypes -137G/-607A and -137C/-607A, carrying the -607A allele, were also associated with susceptibility to LD. The haplotype -137G/-607C was strongly associated with protection against LD. No significant differences in IL-18 -137 and IFN- +874 genotype and allele distribution were observed in patients when compared to a control group. This is the first study evaluating the IL-18 and IFN- polymorphisms in LD and the results suggest that the promoter region of the IL-18 gene is associated with LD development in HIV-infected patients.

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