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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

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

Josias Brito Frazão 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-α 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-α 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.
22

Natural Killer Cells and Pre-B Acute Lymphoblastic Leukemia : Evidence for an Unconventional Cytotoxicity Pathway / Cellules Natural Killer et leucémies aiguës lymphoblastiques pré-B : éléments de preuve d’une voie de cytotoxicité non conventionnelle

Nicoletti, Simon 06 November 2017 (has links)
Les cellules Natural Killer (NK) représentent une population de cellules innées lymphoïdes aux fonctions anti-infectieuses et antitumorales. Les leucémies aiguës lymphoblastiques pré-B (LAL pré-B) constituent le cancer de l’enfant le plus fréquent et ont été décrites comme résistantes à la cytotoxicité médiée par les NK bien que les bases moléculaires demeurent inconnues.L’objectif de ces travaux a été de caractériser cette résistance. En développant un essai de cytotoxicité par cytométrie en flux et en utilisant des cellules effectrices activées in vitro, nous avons établi la sensibilité retardée des LAL pré-B à la cytotoxicité NK : initialement résistantes après 4h d’incubation, elles sont fortement tuées après 25h.Cette cytotoxicité est contact-dépendante mais ni la voie de l’exocytose des granules cytotoxiques ni celle des récepteurs de mort n’y contribuent. La mort cellulaire des cibles est de profil apoptotique mais indépendante des caspases ; la signalisation mitochondriale l’amplifie partiellement. Interférer avec les dérivés de l’oxygène par un antioxydant diminue la cytotoxicité. Nous montrons que les cellules NK de patients atteints de granulomatose septique chronique liée à l’X présentent un défaut de cette nouvelle cytotoxicité. Nous démontrons l’expression par les NK des composants clefs d’une NADPH oxydase distincte du complexe utilisé par les phagocytes. Nos travaux établissent l’existence d’une voie de cytotoxicité non conventionnelle et en définissent les principaux prérequis moléculaires. / Natural Killer (NK) cells are innate lymphoid cells with anti-infectious and anti-tumoral activities. Among neoplasia, pre-B acute lymphoblastic leukemias (pre-B ALL) represent the most common form of cancer in childhood and were shown to be resistant to NK cell mediated cytotoxicity although the mechanisms explaining this phenomenon are incompletely understood.In the present work, we investigated the relative immune resistance of pediatric pre-B ALL targets to activated NK cells. We developed a flow cytometry based cytotoxicity assay to assess the NK activity and the involvement of long term cytotoxic pathways. Although pre-B ALL blasts were strongly resistant at 4h, we found a considerable delayed NK killing at 25h.Further investigations revealed that cell contact was mandatory for efficient killing but also that neither the granule exocytosis nor the death receptor pathway were involved. Target cell death was caspase independent but mitochondria signaling amplified it. We then showed that NK cells from patients with X-linked chronic granulomatous disease could not kill efficiently ALL blasts and that NK cells expressed key components of a NADPH oxidase complex that was distinct from the phagocyte type. Our work reveals an uncharacterized effector pathway among cytotoxic lymphocytes and establishes key molecular requirements for this unconventional pathway.
23

Concomitant Gene Mutations of MBL and CYBB in Chronic Granulomatous Disease: Implications for Host Defense

Watkins, Casey, Saleh, Hana, Song, Eunkyung, Jaishankar, Gayatri Bala, Chi, David S., Misran, Niva, Peiris, Emma, Altrich, Michelle L., Barklow, Thomas, Krishnaswamy, Guha 01 January 2012 (has links)
Chronic granulomatous disease (CGD) is associated with defective function of the NADPH-oxidase system in conjunction with phagocytic defects which leads to granuloma formation and serious infectious complications. This is often associated with significant morbidity and mortality. The association of defective phagocyte function with other coincidental immune defects is unknown. Defects in innate pathways seen with CGD, including complement systems, and toll-like and dectin receptor pathways, have not been described before. We present the case of a 2-year old male patient hospitalized with recurrent pneumonia, a non-healing skin ulcer, necrotizing lung granulomas, and epididymo-orchitis. Defective neutrophil chemiluminescence was detected by dihydrorhodamine (DHR) testing. Further evaluation demonstrated characteristic molecular mutations of CYBB consistent with CGD. Immune evaluation demonstrated polyclonal hyperglobulinemia, but a greatly reduced mannose binding lectin (MBL) level. Six biallelic polymorphisms in MBL gene and its promoter were analyzed using Light Cycler™ Real-time PCR assay. The LXPA/LYPB haplotype of MBL was detected in our patient; the latter is the defective haplotype associated with low MBL levels. Due to the implications for innate immunity and the protection against bacterial, viral, and fungal infections provided by MBL, a deficiency of this protein may have disastrous consequences on the long term outcomes of CGD. MBL deficiency can also complicate other disorders affecting the immune system, significantly increasing the risk of infection in such patients. Further studies looking at the frequency and implications of MBL deficiency in CGD are needed.
24

Uma nova abordagem para o estudo dos defeitos genético-moleculares da doença granulomatosa crônica e análise de suas relações genótipo-fenótipo. / A new approach to study of molecular-genetic defects of chronic granulomatous disease and analysis of its genotype-phenotype relationships.

Oliveira Júnior, Edgar Borges de 30 September 2010 (has links)
A Doença Granulomatosa Crônica é uma imunodeficiência grave e rara, na qual os quadros infecciosos por bactérias e fungos, ocorrem predominantemente nas barreiras naturais do organismo. O defeito reside em mutações em um dos componentes do sistema NADPH oxidase. O dHPLC mostrou-se mais sensível que o SSCP, sendo eficaz na detecção de alterações em 100% dos casos. Identificamos sete mutações diferentes no gene CYBB, sendo quatro delas inéditas. São elas R226X; R290X; e C537R. Dentre as mutações inéditas identificamos: T302fsX46; c.141 +5 G> T; C185R; e H222L. Identificamos a mutação V25fsX51 no gene NCF1 em duas pacientes. Estabelecemos uma correlação entre genótipo e fenótipo clínico baseado em manifestações clínicas relevantes na DGC, nos fornecendo dados importantes de cada manifestação clínica e um índice de gravidade clínica (IGC) para cada tipo de mutação. Os resultados contribuem para a construção de estratégias que permitam a identificação dos defeitos genético-moleculares relacionados à DGC. / Chronic granulomatous disease is a primary immunodeficiency characterized by recurrent and severe infections, affecting the body barriers. In these patients, phagocytes present a failure in the respiratory burst caused by a deficiency of the NADPH oxidase system, and a microbicidal defect. Mutations affecting one of the components of the NADPH oxidase system. The dHPLC proved to be more sensitive to the SSCP, being effective in detecting changes in 100% of cases. We found seven different mutations, four of which are original. Are they R226X; R290X; and C537R. Among the unpublished mutations identified: T302fsX46; c. 141 + 5 G > T; C185R; and H222L. We identify the gene mutation V25fsX51 NCF1 in two patients. We have established a correlation between genotype and phenotype clinical relevant clinical manifestations based on DGC in providing important data from each clinical and clinical severity index (CSI) for each type of mutation. The results contribute to the construction of strategies enabling the identification of molecular genetic defects related to CGD.
25

Uma nova abordagem para o estudo dos defeitos genético-moleculares da doença granulomatosa crônica e análise de suas relações genótipo-fenótipo. / A new approach to study of molecular-genetic defects of chronic granulomatous disease and analysis of its genotype-phenotype relationships.

Edgar Borges de Oliveira Júnior 30 September 2010 (has links)
A Doença Granulomatosa Crônica é uma imunodeficiência grave e rara, na qual os quadros infecciosos por bactérias e fungos, ocorrem predominantemente nas barreiras naturais do organismo. O defeito reside em mutações em um dos componentes do sistema NADPH oxidase. O dHPLC mostrou-se mais sensível que o SSCP, sendo eficaz na detecção de alterações em 100% dos casos. Identificamos sete mutações diferentes no gene CYBB, sendo quatro delas inéditas. São elas R226X; R290X; e C537R. Dentre as mutações inéditas identificamos: T302fsX46; c.141 +5 G> T; C185R; e H222L. Identificamos a mutação V25fsX51 no gene NCF1 em duas pacientes. Estabelecemos uma correlação entre genótipo e fenótipo clínico baseado em manifestações clínicas relevantes na DGC, nos fornecendo dados importantes de cada manifestação clínica e um índice de gravidade clínica (IGC) para cada tipo de mutação. Os resultados contribuem para a construção de estratégias que permitam a identificação dos defeitos genético-moleculares relacionados à DGC. / Chronic granulomatous disease is a primary immunodeficiency characterized by recurrent and severe infections, affecting the body barriers. In these patients, phagocytes present a failure in the respiratory burst caused by a deficiency of the NADPH oxidase system, and a microbicidal defect. Mutations affecting one of the components of the NADPH oxidase system. The dHPLC proved to be more sensitive to the SSCP, being effective in detecting changes in 100% of cases. We found seven different mutations, four of which are original. Are they R226X; R290X; and C537R. Among the unpublished mutations identified: T302fsX46; c. 141 + 5 G > T; C185R; and H222L. We identify the gene mutation V25fsX51 NCF1 in two patients. We have established a correlation between genotype and phenotype clinical relevant clinical manifestations based on DGC in providing important data from each clinical and clinical severity index (CSI) for each type of mutation. The results contribute to the construction of strategies enabling the identification of molecular genetic defects related to CGD.
26

Caracterização clínica e genética de pacientes brasileiros com doença granulomatosa crônica e susceptibilidade mendeliana a infecções por micobactérias / Clinical and Genetic Characterization of Brazilian Patients with Chronic Granulomatous Disease and Mendelian Susceptibility to Mycobacterial Disease

Zurro, Nuria Bengala 29 November 2018 (has links)
Dentre pacientes com imunodeficiências primárias, existem aqueles com defeitos de fagócitos e outros componentes da imunidade inata. A doença granulomatosa crônica (DGC) é uma imunodeficiência primária (IDP) causada por mutações em um dos componentes protéicos, gp91-phox, p22-phox, p47-phox, p67-phox e p40-phox, da nicotinamida adenina dinucleotídeo fosfato (NADPH) dos fagócitos. Pacientes com DGC apresentam maior susceptibilidade a infecções, assim como hiperinflamação e reação adversa à vacinas como à do Bacilo Calmette-Guérin (BCG), como consequência da atividade microbicida defeituosa dos fagócitos. Por outro lado, a susceptibilidade mendeliana a micobactérias (MSMD) é uma condição que predispõe os pacientes a infecções pelo gênero Mycobacterium sp, levando a infecções graves e por vezes à morte. O objetivo deste trabalho foi realizar o diagnóstico clínico e a análise genético-molecular de pacientes brasileiros com DGC e MSMD. A explosão respiratória de granulócitos foi avaliada pelo ensaio de dihidrorodamina (DHR). A dosagem de citocinas do eixo IL-12/IFN-&#947 foi realizada mediante o ensaio de ELISA após estimulo com lisado de micobactérias (LM), proteína purifica (PPD) e BCG. O DNA genômico dos pacientes foi extraído, amplificado e sequenciado pelo método de Sanger e seqüenciamento completo de exoma. Durante o período de 2014-2018, 181 pacientes com histórico clínico sugestivo de DGC e 75 pacientes com diagnóstico sugestivo de MSMD foram encaminhados ao nosso laboratório. Após avaliação clínica e bioquímica dos pacientes, 23 deles foram diagnosticadas com DGC e 16 com MSMD. A análise genético-molecular permitiu identificar mutações em 14 pacientes com DGC, nove deles com DGC ligada ao cromossomo X (DGC-X) e 5 com DGC autossômica recessiva (DGC-AR). Identificamos mutações em 5 pacientes com MSMD, sendo três delas no receptor de IL-12 e duas no receptor da IL-17. / Among patients with primary immunodeficiencies, there are those with defects in phagocytes and other components of the innate immunity. Chronic granulomatous disease (CGD) is a primary immunodeficiency (PID) caused by mutations in one of the protein components, gp91-phox, p22-phox, p47-phox, p67-phox and p40-phox of the Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase of phagocytes. Patients with CDG are susceptible to infections, as well as hyperinflammation and adverse reactions to vaccines such as Bacilo Calmette-Guérin (BCG) as a consequence of defective phagocytes microbicidal activity. On the other hand, Mendelian susceptibility to mycobacterial diseases (MSMD) is a condition that predisposes patients to infections by the genus Mycobacterium sp , leading to serious infections and sometimes death. The main goal of this study was to perform the clinical diagnosis and genetic-molecular analysis of Brazilian patients with CDG and MSMD. The respiratory burst of granulocytes was evaluated by the dihydrorhodamine (DHR) assay. Cytokine dosing of IL-12 / IFN-&#947 axis was performed by the ELISA assay after stimulation with mycobacterium lysate (LM), purified protein (PPD) and BCG. Patients genomic DNA was extracted, amplified and sequenced by the Sanger method and whole exome sequencing. During the period of 2014 to 2018, 181 patients with a clinical history suggestive of CDG and 75 patients with a diagnosis suggestive of MSMD were referred to our laboratory. After clinical and biochemical evaluation, 23 of them were diagnosed with CDG and 16 with MSMD. Genetic-molecular analysis allowed the identification of mutations in 14 patients with CDG, of those 9 had X-linked DGC (X-CGD) and 5 had autosomal recessive CGD (AR-CGD). Mutations were identified in 5 MSMD patients, three in the IL-12 receptor and two in the IL-17 receptor.
27

An IL-4-dependent macrophage-iNKT cell circuit resolves sterile inflammation and is defective in mice with chronic granulomatous disease

Zeng, Melody Yue 03 February 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The immune system initiates tissue repair following injury. In response to sterile tissue injury, neutrophils infiltrate the tissue to remove tissue debris and subsequently undergo apoptosis. Proper clearance of apoptotic neutrophils in the tissue by recruited macrophages, in a process termed efferocytosis, is critical to facilitate the resolution of inflammation and tissue repair. However, the events leading to suppression of sterile inflammation following efferocytosis, and the contribution of other innate cell types are not clearly defined in an in vivo setting. Using a sterile mouse peritonitis model, we identified IL-4 production from efferocytosing macrophages in the peritoneum that activate invariant NKT cells to produce cytokines including IL-4 and IL-13. Importantly, IL-4 from macrophages functions in autocrine and paracrine circuits to promote alternative activation of peritoneal exudate macrophages and augment type-2 cytokine production from NKT cells to suppress inflammation. The increased peritonitis in mice deficient in IL-4, NKT cells, or IL-4Ra expression on myeloid cells suggested that each is a key component for resolution of sterile inflammation. The phagocyte NADPH oxidase, a multi-subunit enzyme complex we demonstrated to require a physical interaction between the Rac GTPase and the oxidase subunit gp91phox for generation of reactive oxygen species (ROS), is required for production of ROS within macrophage phagosomes containing ingested apoptotic cells. In mice with X-linked chronic granulomatous disease (X-CGD) that lack gp91phox, efferocytosing macrophages were unable to produce ROS and were defective in activating iNKT during sterile peritonitis, resulting in enhanced and prolonged inflammation. Thus, efferocytosis-induced IL-4 production and activation of IL-4-producing iNKT cells by macrophages are immunomodulatory events in an innate immune circuit required to resolve sterile inflammation and promote tissue repair.

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