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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.
211

Analyse génétique d'une stérilité hybride chez Arabidopsis thaliana / Genetic analysis of an hybrid sterility in Arabidopsis thaliana

Simon, Matthieu 18 December 2015 (has links)
Un objectif central de la biologie évolutive est la compréhension des mécanismes qui conduisent à la formation de nouvelles espèces. Les stérilités hybrides constituent un type de barrières reproductives pouvant mener à la spéciation. Ce travail dissèque les bases génétiques d’une stérilité mâle observée chez l'hybride entre deux accessions naturelles d'Arabidopsis thaliana, Shahdara et Mr-0, lorsque Shahdara est le parent femelle. Par des approches génétiques et cytologiques, nous montrons que deux phénomènes interviennent dans cette stérilité. D'une part le cytoplasme de Shahdara induit une stérilité mâle cytoplasmique (CMS), en interaction avec plusieurs locus nucléaires. D'autre part, une létalité pollinique est due à plusieurs locus distorteurs de ségrégation (pollen killers). La stérilité de l'hybride résulte d'une liaison génétique entre les déterminants nucléaires de la CMS et les pollen killers. L'un des pollen killers a été localisé dans un intervalle de 70 Kb qui contient également des éléments nécessaires à la restauration de la CMS. Ce locus est complexe et présente de nombreuses variations structurales, notamment au niveau de gènes PPR. Ces résultats suggèrent que deux types de conflits génomiques, les distorteurs de ségrégation et la CMS, pourraient coévoluer dans des populations naturelles et conduire à l’élaboration de barrières reproductives au sein d'une même espèce. / Species differentiation and the underlying genetics of reproductive isolation are central topics in evolutionary biology. Hybrid sterility is one kind of reproductive barrier that can lead to differentiation between species. Here, we analyze the complex genetic basis of the intraspecific hybrid male sterility that occurs in offspring of two distant natural strains of Arabidopsis thaliana, Shahdara and Mr-0, with Shahdara as the female parent. Using genetic approaches as well as cytological observation of pollen viability, we demonstrate that this particular hybrid sterility results from two causes of pollen mortality. First, the Shahdara cytoplasm induces gametophytic cytoplasmic male sterility controlled by several nuclear loci. Second, several segregation distorters leading to allele-specific pollen abortion (pollen killers) operate in the hybrids. The complete sterility of the hybrid with the Shahdara cytoplasm results from the genetic linkage of the two causes of pollen mortality, i.e. CMS nuclear determinants and pollen killers. One pollen killer was localized in a 70 Kb interval which also contains restorer alleles for the CMS. This locus is complex and harbors many structural variations, particularly at PPR genes. Our results suggest that two types of genomic conflicts, CMS and segregation distorters, may coevolve in natural populations and contribute to reproductive isolation, and possibly to speciation.
212

Humanized Mice as Models to study Human Innate Immunity and Immunotherapies / Les souris humanisées comme modèles d'étude de l'immunité innée humaine et des immunothérapies

Lopez-Lastra, Silvia 17 February 2017 (has links)
Les modèles animaux ont largement contribué à notre compréhension de l’immunologie humaine et des mécanismes pathologiques associés au développement des maladies. Cependant, les modèles murins ne permettent pas de reproduire toute la complexité des pathologies humaines. Les souris à système immunitaire humain (HIS), par leur capacité à récapituler l’hématopoïèse humaine et à être infectées par des pathogènes humains, constituent une solution de choix pour combler ce fossé inter-espèce. Après greffe de cellules souches hématopoïétiques humaines, des souris hôtes sévèrement immunodéprimées permettent un haut niveau de développement du système hémato-lymphoïde humain tout au long de leur vie. Cependant, certains types cellulaires, comme les cellules lymphoïdes innées, ne parviennent pas à se différencier et à fonctionner normalement dans les modèles murins HIS actuels. Ici, nous décrivons le développement d’un modèle souris HIS original, nommé BRGSF, montrant une amélioration de la maturation, de la fonction et de l’homéostasie des cellules natural killer (NK) humaines et des autres ILCs. De plus, en récapitulant les différentes étapes du développement des ILCs humaines, ce modèle souris BRGSF nous a permis d’identifier pour la première fois un précurseur d’ILC (ILCP) présent à la fois dans notre modèle HIS ainsi que dans le sang périphérique et plusieurs organes lymphoïdes et non-lymphoïdes humains. Cette population circulante d’ILCPs pourrait constituer un substrat pour la production d’ILCs matures dans les tissus périphériques en réponse à des stress environnementaux, inflammatoires et/ou infectieux. Dans une seconde partie de ce travail de thèse, nous avons utilisé ces souris BRGS afin de tester l’efficacité de deux immunothérapies reposant sur les lymphocytes innés pour le traitement d’un carcinome colorectal exprimant EGFR et muté pour KRAS. La première approche a consisté en la co-administration des cellules NK dérivées de sang de cordon ombilical et d'anticorps monoclonal cetuximab afin de promouvoir le mécanisme de cytotoxicité cellulaire dépendante des anticorps (ADCC) contre la tumeur. La seconde stratégie a reposé sur l’injection de nanobodies VHH combinant l’inhibition de l’EGFR et l’activation spécifique du récepteur Vγ9Vδ2 des cellules T effectrices. Les résultats de cette étude soulignent l’importance des modèles murins HIS pour la compréhension du développement des lymphocytes innés humains et pour mieux les mettre à profit dans les thérapies anti-tumeurs / Animal models have extensively contributed to our understanding of human immunobiology and to uncover the underlying pathological mechanisms occurring in the development of the disease. However, mouse models do not always reproduce the genetic complexity inherent in human disease conditions. Human immune system (HIS) mouse models that are susceptible to human pathogens and can recapitulate human hematopoiesis provide one means to bridge the interspecies gap. Severely immunodeficient host mice support life-long, high level human hematolymphoid development after engraftment with human hematopoietic stem cells (HSC). However, the differentiation and function of some blood cell types, including innate lymphoid cells (ILCs), is poorly characterized in current HIS mice. Here we describe the development of a novel HIS mouse model, named BRGSF, which demonstrate enhanced maturation, function and homeostasis of human natural killer (NK) cells and other ILCs. Furthermore, the BRGSF-based HIS mouse model recapitulated the developmental stages of human ILCs. We could identify for the first time an ILC precursor (ILCP) population that is present both in HIS mice and in human peripheral blood as well as in several lymphoid and non-lymphoid human tissues. This circulating human ILCP population may provide a substrate to generate mature ILCs in tissues in response to environmental stressors, inflammation and infection. In a second part of the thesis we used BRGS immunodeficient mice to assess two innate lymphocyte-based immunotherapeutic approaches for treating EGFR-expressing KRAS-mutated colorectal carcinoma in vivo. The first model used a combination of umbilical cord blood (UCB)-derived NK cells and the monoclonal antibody cetuximab to promote antibody dependent cell cytotoxicity (ADCC) against the tumors. In a second model, we evaluated the therapeutic suitability of novel bispecific VHH constructs that combine inhibition of the EGFR with the target-specific activation of effector Vγ9Vδ2-T cells. These studies highlight the utility for HIS-based mouse models to understand human innate lymphocyte development and to harness these potent effectors for anti-tumor therapies.
213

NK cell alloreactivity against KIR-ligand-mismatched HLA-haploidentical tissue derived from HLA haplotype-homozygous iPSCs. / HLAハプロタイプホモ接合型iPS細胞に由来するKIRリガンド不適合HLA半合致組織に対するNK細胞のアロ反応性

Ichise, Hiroshi 24 November 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第20758号 / 医科博第81号 / 新制||医科||6(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 江藤 浩之, 教授 三森 経世, 教授 杉田 昌彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
214

Population dynamics and distribution of northern Norwegian killer whales in relation to wintering herring

Kuningas, Sanna January 2014 (has links)
The northern Norwegian killer whale (Orcinus orca) is an important predator but little is known about its population dynamics, particular in response to changes in its main prey, the highly dynamic Norwegian spring spawning (NSS) herring (Clupea harengus). The main aims of this thesis were to estimate killer whale population parameters, to explore the future viability of the population, and to explore the response of this predator to changes in distribution and abundance of its main prey over the last 25 years. Population size was estimated as ~ 700 individuals, taking heterogeneity of capture probabilities into account and correcting for unmarked animals. Apparent survival rates of 0.974 (SE = 0.006) for adult males and 0.984 (SE = 0.006) for adult females were estimated accounting for temporary emigration, transience and trap-dependency. Temporary emigration was greater for males than females. Calving intervals ranged from 3 to 14 years (mean = 5.06); equivalent to 0.197 calves per mature female per year. Future viability of the killer whale population was evaluated under various plausible scenarios. The baseline scenario using the best available information predicted a viable population and indicated that the population may be increasing size. Analysis of data on naval sonar activity, killer whale sightings and herring abundance showed that naval sonar activity appeared to have a negative effect on killer whale presence during a period of low prey availability. A time lag of four years was found between the first sign of NSS herring changing its distribution and reduced killer whale presence inside the fjord system. Analysis of energy budgets showed that killer whales spent more time travelling/foraging in 2005/06 than the 1990s. The fjord system was inferred to be a preferred habitat for killer whales when there was a higher density of NSS herring in this area compared to offshore area.
215

Social associations, relatedness and population genetic structure of killer whales (Orcinus orca) in Iceland

Tavares, Sara B. January 2017 (has links)
In killer whales, fish- versus mammal-eating ecological differences are regarded as key ecological drivers of sociality, but the potential influence of specific target prey characteristics remains unclear. This thesis aimed to study the social patterns and dynamics of Icelandic killer whales feeding upon herring, a schooling prey that undergoes frequent changes in distribution and school size. I used a multi-disciplinary approach combining photo-identification and genetic data to understand the sociality, role of kinship and genetic differentiation within the population. Individuals sighted in summer-spawning and overwintering herring grounds during at least five separate days (N = 198) were considered associated if photographed within 20 seconds of each other. Photo-identified individuals were genotyped (N = 61) for 22 microsatellites and mitochondrial DNA control region (611 bp). The population had weak but non-random associations, fission-fusion dynamics at the individual level and seasonal patterns of preferred associations. The society was significantly structured but not hierarchically. Social clusters were highly diverse and, whilst kinship was correlated with association, it was not a prerequisite for social membership. Indeed, some cluster members had different mitochondrial haplotypes, representing separate maternal lineages. Individuals with different observed movement patterns were genetically distinct, but associated with each other. No sex-biased dispersal or inbreeding was detected. This study revealed that the Icelandic population has a multilevel society without clear hierarchical tiers or nested coherent social units, different from the well-studied salmon- (‘residents') and seal-eating populations in the Northeast Pacific. In the Icelandic population kinship drives social structure less strongly than in residents. These findings suggest effective foraging on schooling herring in seasonal grounds promotes the formation of flexible social groupings which can include non-kin. Killer whale sociality may be strongly influenced by local ecological context, such as the characteristics of the specific target prey (e.g., predictability, biomass, and density) and subsequent foraging strategies of the population.
216

Evaluation von KIR-Liganden Inkompatibilität bei unverwandten Knochenmark-/ Stammzelltransplantationen / Role of KIR ligand incompatibility in hematopoietic stem cell transplantation using unrelated donors

Martin, Hilmar 17 July 2005 (has links) (PDF)
We performed a retrospective study in 185 patients with myelogenous leukemias who had received hematopoietic cells from unrelated donors. The aim of this study was to answer the question wether the benefit of KIR ligand incompatibility seen in haploidentical tranplantations can also be seen using unrelated donors. We could not detect a significant difference in survival between patients with a KIR ligand incompatibility and those with either fully matched or partially mismatched unrelated donors in this patient cohort. / In der Therapie von Leukämien ist die Knochenmark- bzw. Stammzelltransplantation eine tragende Säule. Für den Transplantationserfolg ist eine Übereinstimmung der Haupthistokompatibilitätsantige (HLA-Antigene der Klassen I und II) zwischen Spender und Empfänger von zentraler Bedeutung. Diese Notwendigkeit ergibt sich aus der sogenannten MHC-Restriktion in der T-Zellrezeptorerkennung. Ob auch NK-Zellrezeptoren und deren Liganden in der Spenderauswahl berücksichtigt werden sollten, ist bisher unzureichend untersucht. Insbesondere trifft das für die KIR-Rezeptoren zu, die wie die T-Zellrezeptoren ebenfalls HLA-Antigene als Liganden besitzen. Velardi et al. haben 2002 erstmalig gezeigt, daß in der Therapie myeloischer Leukämien die Transplantation von Blutstammzellen verwandter Spender mit KIR-Liganden-Inkompatibilität von klinischem Vorteil ist. Ob KIR-Liganden-Inkompatibilität auch bei Knochenmark-/ Stammzelltransplantationen Unverwandter Bedeutung erlangen könnte, war zu Studienbeginn offen und blieb auch infolge diskrepanter Untersuchungsergebnisse von verschiedenen Arbeitsgruppen im Verlauf der Studie widersprüchlich. Im Rahmen dieser Arbeit wurde diese Fragestellung, die auch Teil einer internationalen Studie war, an 185 Spender-Empfänger-Paaren retrospektiv untersucht. Dabei wurde bei den Paaren einerseits die KIR-Liganden-Kompatibilität auf der Grundlage der HLA-C-Supertypen erschlossen (nach Velardi et al.). Andererseits konnte sie im internationalen Studienprogramm direkt aus dem KIR-Genotyp des Spenders und dem HLA-C-Supertyp des Empfängers ermittelt werden. Die Untersuchungen ergaben folgende Resultate: bei Vorliegen von KIR-Liganden-Inkompatibilität hat die Verwendung von ATG als Bestandteil der GvHD-Prophylaxe keinen Einfluß auf das klinische Ergebnis. Die Vermutungen von Giebel et al. wurden damit nicht gestützt. Die Bestimmung des KIR-Liganden-Status mit Hilfe der Rückschlußmethode allein aus dem HLA-Typ ist unzuverlässig. Für eine exakte Differenzierung ist die gleichzeitige KIR-Genotypisierung erforderlich. KIR-Liganden-Inkompatibilität ist bei unverwandten Knochenmark-/ Stammzelltransplantationen nicht von klinischem Vorteil. Auch ein gezieltes Aussuchen HLA-C-inkompatibler Spender auf der Grundlage einer KIR-Genotypisierung stellt derzeit keine therapeutische Option dar.
217

Natural Killer Cells for Therapy of Leukemia

Suck, Garnet, Linn, Yeh Ching, Tonn, Torsten 05 August 2020 (has links)
Clinical application of natural killer (NK) cells against leukemia is an area of intense investigation. In human leukocyte antigen-mismatched allogeneic hematopoietic stem cell transplantations (HSCT), alloreactive NK cells exert powerful anti-leukemic activity in preventing relapse in the absence of graft-versus-host disease, particularly in acute myeloid leukemia patients. Adoptive transfer of donor NK cells post-HSCT or in non-transplant scenarios may be superior to the currently widely used unmanipulated donor lymphocyte infusion. This concept could be further improved through transfusion of activated NK cells. Significant progress has been made in good manufacturing practice (GMP)-compliant large-scale production of stimulated effectors. However, inherent limitations remain. These include differing yields and compositions of the end-product due to donor variability and inefficient means for cryopreservation. Moreover, the impact of the various novel activation strategies on NK cell biology and in vivo behavior are barely understood. In contrast, reproduction of the thirdparty NK-92 drug from a cryostored GMP-compliant master cell bank is straightforward and efficient. Safety for the application of this highly cytotoxic cell line was demonstrated in first clinical trials. This novel ‘off-theshelf’ product could become a treatment option for a broad patient population. For specific tumor targeting chimeric-antigen-receptor-engineered NK-92 cells have been designed.
218

Caractérisation de l'activité fonctionnelle et métabolique des cellules NK en situation de stress nutritionnels : approche expérimentale in vitro et in vivo / Characterization of functional and metabolic activity of NK cells by nutritional stress : experimental approach in vitro and in vivo

Lamas, Bruno 27 June 2012 (has links)
Les cellules Natural Killer (NK), actrices majeures de la vigilance anti-tumorale, sont modulées par des facteurs nutritionnels et métaboliques. L'inhibition de leur activité favorise le développement tumoral. Un régime alimentaire hypercalorique induisant l'obésité est un facteur de risque de développer un cancer du sein. Au niveau du micro-environnement tumoral mammaire, la biodisponibilité en certaines molécules contrôle non seulement les cellules néoplasiques mais, également les cellules immunes infiltrées. Ainsi, la leptine, sécrétée à forte concentration par les adipocytes mammaires, pourrait favoriser la croissance tumorale et altérer les cellules NK. L'arginine fortement consommée par les cellules tumorales et les cellules suppresseurs dérivées des myéloïdes pourrait faire défaut aux cellules NK. L'objectif de cette thèse est de caractériser les activités fonctionnelles et métaboliques des cellules NK en situation de stress nutritionnel. Dans un premier temps, nous avons exploré, in vivo, l'impact d'un régime hypercalorique sur l'activité des cellules NK et sur le développement tumoral mammaire. Ensuite, nous avons cherché à identifier les potentielles altérations fonctionnelles des cellules NK en mimant, in vitro, les conditions retrouvées au niveau du micro-environnement tumoral telles que la présence de concentration élevée en leptine et la déplétion en arginine. Des souris Balb-c "nude" femelles ont été soumises à un régime hypercalorique (HC) versus une diète normo-calorique (NC) pendant 6 mois. Au bout de 5 mois, des cellules tumorales mammaires (MCF-7 ; groupes NCT et HCT) ou le véhicule (groupes NC et HC) ont été implantés au niveau de la quatrième paire de glandes mammaires. Sous régime HC, le développement tumoral s'accompagne d'une perte de masse grasse, de masse maigre et de poids corporel avec un volume et un poids de tumeur augmentés. Cette diète induit au niveau tumoral une sur-expression des ARNm d'enzymes impliquées dans la glycolyse et une sous-expression des acteurs du cycle de Krebs. Sous régime HC, l'expression de la caspase 3 clivée et des récepteurs des oestrogènes β et de la progestérone est réduite alors que celle du Ki67 est accrue. Les cellules NK des souris HC ont une cytotoxicité diminuée. Bien que la présence de tumeur stimule l'activité lytique des cellules NK, la cytotoxicité de ces cellules reste inférieure dans le groupe HCT comparativement à celle du groupe NCT. La leptine stimule, in vitro, de façon dose-dépendante l'activité métabolique des cellules NK. A fortes concentrations, elle active leur cytotoxicité vis-à-vis des cellules cibles MDA-MB-231. Cet effet passe par une stimulation de l'expression de TRAIL et de l'IFN-γ par les cellules NK. En revanche, vis-à-vis des cellules cibles MCF7, les cellules NK présentent une activité lytique réduite en présence de fortes concentrations de leptine, probablement en lien avec une réduction de l'expression de la perforine. En réponse à une déplétion en arginine dans le milieu de culture, la prolifération et la cytotoxicité des cellules NK sont abaissées. L'altération de la reconnaissance des cellules cibles par les récepteurs NKp46 et NKp30, la moindre transmission du signal activateur par la chaine ζ et la faible production d'IFN-γ peuvent expliquer l'inhibition de la cytotoxicité des cellules NK. Ainsi, un apport énergétique élevé favorise le développement tumoral mammaire notamment eninhibant la cytotoxicité des cellules NK. De plus, la leptine à fortes concentrations stimule ou réduit, in vitro, la cytotoxicité des cellules NK selon la nature des cellules cancéreuses mammaires cibles. Une déplétion en arginine, in vitro, quant à elle, inhibe la prolifération et la cytotoxicité des cellules NK. Ces travaux contribuent à mieux comprendre l'impact du micro-environnement sur la réponse antitumorale des cellules NK. / Natural killer (NK) cells are critical mediators of anti-tumor immunity. A high-calorie diet inducing obesity is associated with breast cancer development. NK cells are modulated by dietary and metabolic factors and a decrease in their lytic activity promotes mammary tumor development. In the breast microenvironment, high concentration of leptin can be secreted by mammary adipocytes and thereby could stimulate tumor growth and control immune cells. Arginine, strongly consumed by tumor and myeloid-derived suppressor cells, could be lacking to NK cells. The aim of this work is to characterize the functional and metabolic activities of NK cells in response to nutritional stress. Initially, we explored in vivo the impact of a high-calorie diet on NK cells activity and mammary tumor development. Then, we identified potential functional alterations in NK cells by mimicking the conditions found in the tumor microenvironment such as the presence of high leptin concentration and arginine depletion. Female Balb-c nude mice were fed a high-caloric diet (HC) versus a standard caloric diet (SC) for 6 months. After five months, mammary tumor cells (MCF-7, SCT, HCT) or MatrigelTM (SC, HC) were implanted into the fourth mammary fat pads. The tumor development in HC diet-fed mice was associated with a decrease in body weight, body fat and lean mass and an increase in volume and weight of tumors. This diet induced tumor over-expression, at the transcriptional level, of enzymes involved in glycolysis and a down-expression of citrate cycle actors. Protein tumor levels of cleaved caspase 3, estrogen β and progesterone receptors were reduced while Ki67 was increased in the HC diet-fed mice. NK cell cytotoxicity of HC diet-fed mice was reduced. Although the presence of tumor stimulated NK cell lytic activity, this later was lower in the HCT group compared to the one of SCT mice. In vitro, leptin stimulated, in dose-dependent manner, the metabolic activity of NK cells. High leptin concentrations enhanced NK cell cytotoxicity against the MDA-MB-231 target cells. This phenomenon involved the increase of expression of TRAIL and IFN-γ in NK cells. However, against the MCF-7 target cells, NK cell lytic activity was reduced in the presence of high concentrations of leptin, probably in link to the decreased perforin expression. NK cell proliferation and cytotoxicity were impaired in response to arginine depletion. This inhibition of NK cell cytotoxicity could be linked to a low target cells recognition by NKp46 and NKp30, a reduced activating signal transmission by ζ chain and a low production of IFN-γ. Thus, high energy intake promotes mammary tumor development in particular by inhibiting NK cell cytotoxicity. In vitro, high leptin concentrations stimulate or reduce NK cell cytotoxicity according to the breast cancer cell targets. Furthermore, arginine depletion inhibits NK cell proliferation and cytotoxicity in vitro. These findings provide insight into the microenvironment impacts on NK cell antitumor response in tumor development.
219

Caractérisation des variations fonctionnelles des cellules NK entre deux lignées murines

Mullins-Dansereau, Victor 08 1900 (has links)
No description available.
220

Perfil fenotípico e funcional de células Natural Killers induzido por ligantes de receptores Toll-like e células T CD8+ antígeno-específicas em indivíduos expostos e não infectados por HIV-1 / Phenotypic and functional profile of Natural Killer cells induced by Toll-like receptors ligands and antigen-specific CD8+ T cells in HIV-1 exposed uninfected individuals

Lima, Josenilson Feitosa de 14 March 2014 (has links)
Introdução: A resistência a infecção pelo HIV-1 depende de fatores virais, genéticos e imunológicos do hospedeiro, incluindo os componentes da resposta imune inata e adaptativa. As células Natural Killer (NK) e as células T CD8+ são as principais células efetoras que medeiam atividade citotóxica contra células transformadas ou infectadas, que exercem importante papel protetor nos indivíduos expostos e não infectados por HIV-1 (ENI). Objetivo: Avaliar a expressão de receptores de ativação e inibição/exaustão nas células NK e T CD8+, e a capacidade das células NK em secretar citocinas e componentes citotóxicos após estimulação via receptores Toll-like (TLRs), e a resposta de células T CD8+ a peptídeos da Gag do HIV-1 em indivíduos ENI e seus parceiros infectados por HIV-1. Resultados: No grupo ENI foi observado aumento da frequência de células NK CD56bright que expressam moléculas de ativação NKG2D e CD95 na população CD56dim, enquanto no grupo HIV-1 foi mais prevalente a expressão de MIC A/B em ambas populações de células NK, com redução da expressão de NKG2D na população CD56dim. Além disto, foi observado expansão da população de células NK CD56dim que expressam CD94, NKG2C e principalmente de CD57 foi mais prevalente nos indivíduos ENI, com correlação positiva com títulos de anticorpos IgG anti-citomegalovírus humano. Nos indivíduos ENI foi observado que a ativação via TLR-3, TLR-7 ou TLR-7/8 foi capaz de potencializar a expressão de marcadores de desgranulação e de citotoxicidade, CD107a e granzima B, principalmente na população CD56dim, e de IFN-y e TNF nas populações CD56bright e CD56dim. Além disto, somente o grupo ENI, foi detectado aumento da freqüência de células NK secretoras de CD107a, granzima B, IFN-y e TNF, após estimulação com acetato de miristato de forbol e ionomicina. A frequência de expressão de alelos de KIR (killer cell immunoglobulin-like receptors) foi similar entre os grupos analisados. Elevada frequência de células T CD8+ CD38+ e CD8+PD-1+ (programmed cell death protein 1) foi detectado nos grupos ENI e HIV-1, cuja alteração foi observada em todas as fases de maturação celular. Os indivíduos ENI mostraram presença de resposta antígeno-específica de células T CD8+ secretoras de CD107a, granzima B, IFN-y e TNF, semelhante ao grupo HIV-1. Conclusão: Os resultados mostraram que no grupo ENI, as células NK expressam um perfil de ativação, com potente resposta aos estímulos de resposta inata e células NK com perfil de memória. Presença de células TCD8+ antígeno-específica foi evidenciada no grupo ENI, com perfil semelhante, mas de menor magnitude ao detectado no grupo infectado por HIV. Em conjunto, os achados mostraram que no grupo ENI a resposta inata está potencialmente ativa, e que em associação a resposta T CD8+ antígeno-específica podem contribuir para a resistência a infecção pelo HIV-1 / Introduction: Resistance to human immunodeficency virus 1 (HIV-1) is dependent on viral, genetic and immunological host factors, including components of innate and adaptive immune response. Natural Killers cells (NK) and CD8+ T cells are main effectors cells mediating cytotoxic role against transformed or infected cells, playing a crucial role in HIV-1 exposed uninfected individuals (EU). Aim: To evaluate the expression of activation and inhibitory/exhaustion receptors on NK cells and CD8+ T-cells, and to determine the NK cells ability to cytokines and cytotoxic molecules secretion upon Toll-like receptors (TLRs) pathway activation as well as CD8+ T-cells response to HIV Gag peptides in EU individuals and HIV-1 infected partner. Results: Increased frequency of NK CD56bright cells expressing NKG2D and CD95 on CD56dim cells have been observed in EU group, while HIV-1 group was more prevalent MIC A/B expression in both NK cells subsets, with reduced expression of NKG2D in CD56dim cells. Moreover, expansion of NK CD56dim cells expressing CD94, NKG2C, and CD57 was prevalent on ENI group, which positive correlation with anti-human cytomegalovirus IgG serum titers. EU individuals showed that TLR-3, TLR-7 or TLR-7/8 pathway activation was able to enhance CD107a and granzyme B expression in CD56dim cells, and IFN-y and TNF expressions levels in both CD56bright and CD56dim NK cells. Moreover, only in EU group, high frequency of NK cells expressing CD107a, granzyme B, IFN-y and TNF were detected upon phorbol myristate acetate and ionomicyn stimulation. Frequency of KIR alleles (killer cell immunoglobulin-like receptors) was similar between groups. High frequency of CD8+CD38+ and CD8+PD-1+ (programmed cell death protein 1) T-cells were observed in EU and HIV-1 groups, in all stages of cellular differentiation. EU subjects showed presence of antigen-specific response by CD8+ T-cells secreting CD107a, granzyme B, IFN-y and TNF similar to HIV-1 group. Conclusion: The results showed that NK cells in EU subjects express activating profile, with potent ability to innate immune stimuli, as well as NK cells with memory profile. Presence of antigen-specific CD8+ T-cells was detected in EU group, with similar profile, but in less magnitude than HIV-1 group. Taken together, the findings showed an enhanced innate immune response in EU subjects, in association with antigen-specific CD8+ T-cell response can contribute to resistance to HIV-1 infection

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