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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

Estudo de polimorfismos dos genes KIR e HLA em sangue de cordão umbilical e placentário de recém-nascidos a termo e pré-termo

Marquezotti, Fernanda January 2014 (has links)
Background. O nascimento pré-termo permanece sendo grande causa de mortalidade neonatal. A vulnerabilidade dos prematuros se dá principalmente pelas freqüentes intervenções médicas e por sua imaturidade imunológica. As infecções neonatais aumentam a probabilidade de complicações e prolongam o tempo de internação, aumentando o risco de mortalidade. A atividade das células Natural Killer (NK) em recém-nascidos prematuros está reduzida e associada com maior susceptibilidade a agentes infecciosos. As células NK são capazes de mediar a resposta do sistema imune inato contra células infectadas por vírus e células malignas transformadas, podendo provocar um ataque direto às células alvo. Os principais receptores das células NK são os KIR ou killer immunoglobulin-likereceptors que reconhecem moléculas de HLA classe I. Objetivo. Investigar o polimorfismo dos genes KIR e HLA de classe I nos recémnascidos pré-termos de muito baixo peso em comparação com recém-nascidos a termo. Métodos. Foram genotipados 154 recém-nascidos, 60 pré-termo e 94 a termo, para 16 genes KIR e seus ligantes HLA pelos métodos PCR SSO e PCR SSP, respectivamente. Resultados. Há diferença estatísticamente significativa (P<0.0001) entre recémnascidos pré-termo e a termo para o gene KIR2DS4, sendo menos freqüente no grupo de recém-nascidos pré-termos. Conclusões. A menor frequência do KIR2DS4 evidencia uma imunidade natural deficiente nesse grupo de recém-nascidos prematuros. / Background. Preterm birth remains a major a cause of neonatal mortality. Preterm infants are particularly vulnerable because of frequent medical intervention and an immature immune system. Neonatal infections increase the likelihood of complications and prolong hospital stay, increasing the risk of mortality. The activity of natural killer (NK) cells is reduced in preterm neonates and associated with increased susceptibility to infectious agents. NK cells are capable of mediating the innate immune response to virally infected cells and malignantly transformed cells, which might lead to a direct attack on target cells. Killer-cell immunoglobulin-like receptors (KIR) are the main NK cell receptors, and are known to recognize Human Leukocyte Antigen (HLA) class I molecules. Objective. To investigate polymorphisms of KIR and HLA class I genes in very low birth weight preterm neonates compared with full-term neonates. Methods. 154 neonates, 60 preterm and 94 full-term, were genotyped for 16 KIR genes and their HLA ligands by PCR-SSO and PCR-SSP respectively. Results. There was a statistically significant difference (P<0.0001) between preterm and full-term neonates for the KIR2DS4 gene, which was less frequent in preterm neonates. Conclusions. The lower frequency of KIR2DS4 indicates a deficient innate immune response in the group of preterm neonates.
2

Estudo de polimorfismos dos genes KIR e HLA em sangue de cordão umbilical e placentário de recém-nascidos a termo e pré-termo

Marquezotti, Fernanda January 2014 (has links)
Background. O nascimento pré-termo permanece sendo grande causa de mortalidade neonatal. A vulnerabilidade dos prematuros se dá principalmente pelas freqüentes intervenções médicas e por sua imaturidade imunológica. As infecções neonatais aumentam a probabilidade de complicações e prolongam o tempo de internação, aumentando o risco de mortalidade. A atividade das células Natural Killer (NK) em recém-nascidos prematuros está reduzida e associada com maior susceptibilidade a agentes infecciosos. As células NK são capazes de mediar a resposta do sistema imune inato contra células infectadas por vírus e células malignas transformadas, podendo provocar um ataque direto às células alvo. Os principais receptores das células NK são os KIR ou killer immunoglobulin-likereceptors que reconhecem moléculas de HLA classe I. Objetivo. Investigar o polimorfismo dos genes KIR e HLA de classe I nos recémnascidos pré-termos de muito baixo peso em comparação com recém-nascidos a termo. Métodos. Foram genotipados 154 recém-nascidos, 60 pré-termo e 94 a termo, para 16 genes KIR e seus ligantes HLA pelos métodos PCR SSO e PCR SSP, respectivamente. Resultados. Há diferença estatísticamente significativa (P<0.0001) entre recémnascidos pré-termo e a termo para o gene KIR2DS4, sendo menos freqüente no grupo de recém-nascidos pré-termos. Conclusões. A menor frequência do KIR2DS4 evidencia uma imunidade natural deficiente nesse grupo de recém-nascidos prematuros. / Background. Preterm birth remains a major a cause of neonatal mortality. Preterm infants are particularly vulnerable because of frequent medical intervention and an immature immune system. Neonatal infections increase the likelihood of complications and prolong hospital stay, increasing the risk of mortality. The activity of natural killer (NK) cells is reduced in preterm neonates and associated with increased susceptibility to infectious agents. NK cells are capable of mediating the innate immune response to virally infected cells and malignantly transformed cells, which might lead to a direct attack on target cells. Killer-cell immunoglobulin-like receptors (KIR) are the main NK cell receptors, and are known to recognize Human Leukocyte Antigen (HLA) class I molecules. Objective. To investigate polymorphisms of KIR and HLA class I genes in very low birth weight preterm neonates compared with full-term neonates. Methods. 154 neonates, 60 preterm and 94 full-term, were genotyped for 16 KIR genes and their HLA ligands by PCR-SSO and PCR-SSP respectively. Results. There was a statistically significant difference (P<0.0001) between preterm and full-term neonates for the KIR2DS4 gene, which was less frequent in preterm neonates. Conclusions. The lower frequency of KIR2DS4 indicates a deficient innate immune response in the group of preterm neonates.
3

Estudo de polimorfismos dos genes KIR e HLA em sangue de cordão umbilical e placentário de recém-nascidos a termo e pré-termo

Marquezotti, Fernanda January 2014 (has links)
Background. O nascimento pré-termo permanece sendo grande causa de mortalidade neonatal. A vulnerabilidade dos prematuros se dá principalmente pelas freqüentes intervenções médicas e por sua imaturidade imunológica. As infecções neonatais aumentam a probabilidade de complicações e prolongam o tempo de internação, aumentando o risco de mortalidade. A atividade das células Natural Killer (NK) em recém-nascidos prematuros está reduzida e associada com maior susceptibilidade a agentes infecciosos. As células NK são capazes de mediar a resposta do sistema imune inato contra células infectadas por vírus e células malignas transformadas, podendo provocar um ataque direto às células alvo. Os principais receptores das células NK são os KIR ou killer immunoglobulin-likereceptors que reconhecem moléculas de HLA classe I. Objetivo. Investigar o polimorfismo dos genes KIR e HLA de classe I nos recémnascidos pré-termos de muito baixo peso em comparação com recém-nascidos a termo. Métodos. Foram genotipados 154 recém-nascidos, 60 pré-termo e 94 a termo, para 16 genes KIR e seus ligantes HLA pelos métodos PCR SSO e PCR SSP, respectivamente. Resultados. Há diferença estatísticamente significativa (P<0.0001) entre recémnascidos pré-termo e a termo para o gene KIR2DS4, sendo menos freqüente no grupo de recém-nascidos pré-termos. Conclusões. A menor frequência do KIR2DS4 evidencia uma imunidade natural deficiente nesse grupo de recém-nascidos prematuros. / Background. Preterm birth remains a major a cause of neonatal mortality. Preterm infants are particularly vulnerable because of frequent medical intervention and an immature immune system. Neonatal infections increase the likelihood of complications and prolong hospital stay, increasing the risk of mortality. The activity of natural killer (NK) cells is reduced in preterm neonates and associated with increased susceptibility to infectious agents. NK cells are capable of mediating the innate immune response to virally infected cells and malignantly transformed cells, which might lead to a direct attack on target cells. Killer-cell immunoglobulin-like receptors (KIR) are the main NK cell receptors, and are known to recognize Human Leukocyte Antigen (HLA) class I molecules. Objective. To investigate polymorphisms of KIR and HLA class I genes in very low birth weight preterm neonates compared with full-term neonates. Methods. 154 neonates, 60 preterm and 94 full-term, were genotyped for 16 KIR genes and their HLA ligands by PCR-SSO and PCR-SSP respectively. Results. There was a statistically significant difference (P<0.0001) between preterm and full-term neonates for the KIR2DS4 gene, which was less frequent in preterm neonates. Conclusions. The lower frequency of KIR2DS4 indicates a deficient innate immune response in the group of preterm neonates.
4

Immunomodulation des fonctions effectrices des cellules NK par le contrôle des intéractions de leurs récepteurs inhibiteurs avec les molécules du complexe majeur d'histocompatibilité (CMH) de classe I / Immunomodulation of NK functions by the blockade of the interactions between their inhibitory receptors with their Major Histocompatibility Class I molécules ligands

Sola, Caroline 27 November 2013 (has links)
Les cellules Natural Killer (NK) sont des lymphocytes capables de tuer les cellules tumorales avec une expression altérée des molécules du Complexe Majeur d’Histocompatibilité (CMH) de classe I . Chez l’homme, cette reconnaissance de “l’absence du soi” est relayée par l’absence d’engagement des antigènes des leucocytes humains (HLA) par les récepteurs inhibiteurs des cellules NK. Chez l’homme, ces récepteurs inhibiteurs incluent les récepteurs KIR qui ont comme analogues fonctionnels chez les rongeurs les lectines Ly49. Certaines tumeurs échappent à la surveillance des NK en augmentant leur expression des molécules HLA. Donc, bloquer les interactions entre les molécules KIR et HLA est une stratégie anti-tumorale intéressante qu’INNATE PHARMA a décidé d’explorer en développant l’anticorps thérapeutique anti-KIR 1-7F9. Mais, ces interactions sont nécessaires pour l’acquisition des fonctions des NK, i.e leur éducation. De plus, elles sont impliquées dans la tolérance aux cellules du soi par les cellules NK. Anticiper la toxicité de 1-7F9, évaluer ses propriétés anti-tumorales et son impact sur l’éducation des NK étaient les objectifs de notre travail. Deux modèles murins ont été développées à ces fins. Le premier, est basé sur les souris B6 : les récepteurs inhibiteurs Ly49 C/I ont pour ligand les molécules H-2b. Le second modèle est basé sur des souris transgéniques pour un unique récepteur KIR et son ligand, en l’absence des molécules endogènes de CMH de classe I murines. Ces deux modèles ont montré que le blocage des récepteurs inhibiteurs n’altère pas la tolérance au soi des NK et est une stratégie anti-tumorale efficace qui n’altère pas la fonctionnalité des NK. / Natural Killer cells (NK cells) are lymphocytes able to kill tumors with aletered expression of Major Histocompatibility Complex (MHC) class I molecules. This “missing self” recognition is mediated by the lack of engagement of Human Leukocytes Antigens (HLA) with NK inhibitory receptors that include Killer Immunoglobulin like Receptors (or KIR) in humans. In rodents, the functional analogues of KIR are Ly49 lectins. Some tumors escape NK cell immune surveillance by increasing the expression of HLA molecules on their surface. So, blocking interactions between KIR and HLA molecules constitutes an interesting therapeutic strategy that INNATE PHARMA decided to explore, developing the anti-KIR monoclonal antibody 1-7F9. Nevertheless, these interactions are necessary for the acquisition of NK functional properties, i.e for their “education”. They are also involved in self-tolerance on educated NK cells. For the pre-clinical development of 1-7F9, it was necessary to anticipate anti-KIR mAb safety and toxicity, evaluate its anti-cancer potential and its impact on NK education. A first part of our work was performed in a surrogate B6 mouse model:Ly49 C/I inhibitory receptors have H-2b molécules as endogenous ligand. Their interactions were blocked with anti-Ly49 C/I monoclonal antibody. In a second part, we report the generation of transgenic mice expressing a single inhibitory KIR in the context of its HLA ligand and in absence of endogenous mouse MHC class I molecules. Both models showed that the blockade of NK inhibitory receptors interactions with their endogenous ligands did not break self tolerance, had a strong anti-tumor effect and did not abrogate NK functionality.
5

Importância dos genes KIR e dos genes de citocinas no Linfoma difuso de grandes células B / Importance of KIR genes and cytokine genes in diffuse large B cell lymphoma

Marangon, Amanda Vansan, 1985- 24 August 2018 (has links)
Orientadores: Carmino Antonio de Souza, Jeane Eliete Laguila Visentainer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T20:55:46Z (GMT). No. of bitstreams: 1 Marangon_AmandaVansan_D.pdf: 2274304 bytes, checksum: 433df5157fab3588b51689f24c4b86cf (MD5) Previous issue date: 2014 / Resumo: O Linfoma difuso de grandes células B (LDGCB) representa o subtipo mais prevalente de linfoma maligno não-Hodgkin, sendo responsável por 30-40% de todos os casos de LNH. O LDGCB não tem etiologia e patogênese bem definidas, porém o seu desenvolvimento parece estar relacionado a respostas imunes ineficazes, devido a frequente associação desse linfoma com estados de imunossupressão. Os fatores genéticos envolvidos no desenvolvimento e evolução da doença não são bem entendidos. Nesse contexto, o objetivo desse trabalho foi avaliar a influência dos genes KIR, dos ligantes HLA e do polimorfismo em genes de citocinas na susceptibilidade ou resistência ao desenvolvimento de LDGCB, bem como na evolução clínica e resposta ao tratamento. Para tanto, foram selecionados 112 pacientes com diagnóstico de LDGCB e 292 doadores de sangue e medula óssea como grupo controle. As tipificações dos genes KIR e dos ligantes HLA foram realizadas com a técnica de PCR-SSOP e a tipificação de citocinas foi realizada com a técnica PCR-SSP. As análises estatísticas foram realizadas pelo pacote estatístico "R" versão 3.0.2 para o programa Windows e os valores de P<0,05 foram considerados significativos. A distribuição dos genes KIR nos grupos estudados mostrou uma menor frequência do gene KIR2DL2 nos pacientes quando comparados aos controles (45,5% vs 58,1%; P=0,036), essa associação mostrou-se significativa também na combinação de KIR2DL2 com C1 (33,0%vs 45,9%; P=0,026) sugerindo um papel de proteção desse gene ao desenvolvimento de LDGCB. Em relação à evolução clínica da doença, os ligantes HLA-Bw4 e HLA-Bw4 80I foram mais frequentes nos pacientes com estádios mais avançados da doença (64,7% vs 40,9%; P=0,020 e 44,1% vs 25,0%; P=0,046, respectivamente) sugerindo que a presença desses ligantes pode ser fator de prognóstico ruim ao LDGCB. Em relação à resposta terapêutica, o gene KIR2DL3 foi associado positivamente ao tratamento do LDGCB, pois esse gene foi mais frequente nos indivíduos com resposta completa que nos indivíduos não respondedores (88,3% vs 71,0%; P=0,044). A respeito dos genes reguladores de citocinas, o genótipo IFN-gama-874/A:A foi associado positivamente ao LDGCB, sendo encontrado mais frequente nos pacientes que nos controles (50,9% vs 27,9%; P=0,001). Contrariamente os genótipos: IFN-gama-874/T:A, IL10-819/C:C e IL10-592/C:C foram menos frequentes nos pacientes que nos controles (P=0,001; P=0,025; P=0,025). Ademais, o genótipo IL10-1082/G:G foi relacionado a maior sobrevida livre de progressão. Os resultados encontrados sugerem que os genes KIR, os ligantes HLA e os genes de citocinas parecem ter envolvimento na proteção, susceptibilidade, evolução clínica e resposta ao tratamento do LDGCB / Abstract: Diffuse large B-cell lymphoma (DLBCL) is the most prevalent subtype of malignant non-Hodgkin lymphoma and affects approximately 30-40 % of all cases. The DLBCL has no clearly defined etiology and pathogenesis, but its development seems to be related to ineffective immune responses due to frequent association of lymphoma with immunosuppression. Genetic factors involved in the development and progression of the disease are not well understood. The aim of this study was to evaluate the influence of KIR genes, HLA ligands and cytokine polymorphisms in the susceptibility or resistance to the development of DLBCL, as well as influence in the clinical course and response to treatment. To this end, we selected 112 patients with DLBCL and 292 bone marrow donors as control group. The typing of KIR genes and HLA ligands were performed by PCR-SSOP and typing of cytokine genes was performed by PCR-SSP technique. Statistical analyzes were performed by the statistical package " R " version 3.0.2 for Windows program. P values < 0.05 were considered significant. The distribution of KIR genes in both groups showed a lower frequency of the KIR2DL2 gene in patients compared to controls (45.5% vs 58.1% P=0.036), this association was significant also in combination KIR2DL2 with C1 (33.0% vs 45.9%, P=0.026) suggesting a protective role of this gene to the development of DLBCL. Regarding the clinical course of the disease, HLA-Bw4 and HLA-Bw4 80I ligands were more frequent in patients with more advanced stages of the disease (64.7% vs 40.9%, P=0.020 and 44.1% vs 25 0%, P=0.046, respectively) suggesting that the presence of these ligands may be poor prognostic factor to DLBCL. In regard to treatment response, the KIR2DL3 gene was positively associated with the treatment of DLBCL, because this gene was more frequent in individuals with complete response than in nonresponders individuals (88.3% vs 71.0%, P=0.044 ). Regarding the cytokine genes , IFN -gamma-874/A genotype:A/A was positively associated with DLBCL, it was more frequently in patients than in controls (50.9% vs 27.9%, P=0.001). On other hand genotypes: IFNG -874 /T:A, IL10-819/C:C and IL10 -592 /C:C were less frequent in patients than in controls (P=0.001, P=0.025, P=0.025 respectively). Moreover, the genotype IL-1082/G:G was related to increased progression-free survival. The results suggest that the KIR genes, HLA ligands and cytokine genes seem to be involved in the protection, susceptibility, clinical course and response to treatment of DLBCL / Doutorado / Clinica Medica / Doutora em Clínica Médica

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