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Intestinal immune activation in juvenile idiopathic arthritisArvonen, M. (Miika) 28 May 2013 (has links)
Abstract
The etiology of juvenile idiopathic arthritis (JIA) is still unknown but genetic and enviromental factors play role in the pathogenesis. The aim of the study was to detect endoscopic and immunohistological changes in the gut in JIA compared with the controls and potential correlation of mucosal immunological activation with clinical activity of JIA. JIA patients (n=26) and negative controls (n=71) suffering from gastrointestinal symptoms without significant gastrointestinal disease were recruited for the study. Positive controls were patients with cows milk protein sensitive enteropathy (n=24). The intraepithelial lymphocytes counts, cytotoxic (granzyme A, B) and gamma/delta T-cell count and HLA-DR antigens were evaluated by using immunohistochemistry and messenger RNA expression levels of important immune mediators were assessed with real time PCR (RT-PCR) from fresh frozen intestinal mucosal samples.
In JIA compared with negative controls, there was increased presence of lymphonodular hyperplasia and expression of HLA-DR antigens in abnormal mucosal cites, in crypts of the ileum. These changes were correlating with activity of JIA. In JIA compared with negative controls, there were found elevated granzyme B but decreased cytoprotective heat shock protein expression. The mRNA expression levels of anti- inflammatory mediators like TGFβ, IL10 and transcriptor factor of regulatory T-cells FOXP3, inversely correlated with activity of JIA. In conclusion, patients with JIA suffering from gastrointestinal symptoms display evidence of intestinal mucosal immune activation and there is an association between levels of mucosal immune alteration and clinical activity of JIA. These findings support the hypothesis that there is a link between the intestinal immune system and pathogenesis of juvenile idiopathic arthritis. In order to confirm these findings, more extensive series of JIA patients without gastrointestinal symptoms needs to be examined. / Tiivistelmä
Lastenreuman tautimekanismi on tuntematon. Geneettiset ominaisuudet ja ympäristötekijät ovat yhteydessä taudin syntyyn. Tutkimuksen tavoitteena oli selvittää, onko suolen limakalvolla endoskooppisia tai immunohistologisia muutoksia enemmän lastenreumassa kuin kontrolleilla, ja että liittyvätkö muutokset niveltaudin aktiivisuuteen. Tutkimukseen otettiin 26 suolioireista lastenreumapotilasta, 76 verrokkia joilla ei ollut autoimmuunisairautta sekä 24 viivästynyttä maitoallergiaa sairastavaa lasta, joille tehtiin suolen tähystystutkimus. Ohutsuolinäytteistä arvioitiin immunohistologisesti solunsisäisten lymfosyyttien, gamma/delta-positiivisten lymfosyyttien sekä sytotoksisten (grantsyymi-A ja -B) lymfosyyttien määrä. Lisäksi määritettiin immunohistologisesti ohutsuolen limakalvon epiteelisolujen HLA-DR- antigeenien ja epiteelisolua suojaavien lämpöshokkiproteiinien ilmenemistä sekä käänteis-PCR-menetelmällä keskeisten välttäjäaineiden lähetti-RNA-tasoja.
Tutkimuksessa lastenreumaa sairastavilla esiintyi enemmän suolen imukudoskertymää (lymfonodulaarinen hyperplasia) negatiiviseen verrokkiryhmään nähden sekä HLA-DR antigeenejä epätyypillisellä alueella ohutsuolen loppuosan limakalvon kryptassa. Nämä löydökset olivat yhteydessä lastenreuman aktiivisuuteen. Lastenreumassa oli verrokkeja enemmän sytotoksisia lymfosyyttejä ja vähemmän lämpöshokkiproteiineja. Tulehdusta suojaavat lähetti- RNA-tasot korreloivat käänteisesti lastenreumataudin aktiivisuuteen.
Väitöstutkimuksen suolioireisilla lastenreumapotilailla oli suolen limakalvolla muutoksia, jotka sopivat poikkeavaan antigeenien käsittelyyn. Nämä löydökset tukevat hypoteesia, että lastenreumassa suolen limakalvon immunologinen aktivaatio on yhteydessä taudin puhkeamiseen. Jotta tulokset voisi yleistää, tarvittaisiin jatkotutkimus, joka on tehty suolioireettomilla lastenreumapotilailla ja riittävällä otoskoolla.
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Caractérisation et influence des lymphocytes T CD4 anti-télomérase dans les cancers / Characterization and influence of CD4 T lymphocites specific of telomerase in cancersDosset, Magalie 03 December 2012 (has links)
L’histoire naturelle du cancer implique des interactions entre la tumeur et les mécanismes de défense de l’hôte, tout particulièrement avec le système immunitaire adaptatif. Ainsi la transformation de cellules normales en cellules malignes peut engendrer l’expression d’antigènes tumoraux reconnus par les lymphocytes T. Plusieurs sous-populations de lymphocytes T (LT) CD4 contrôlent les réponses antitumorales, parmi elles, les LT CD4 helper de type-1 (Th1) jouent un rôle activateur majeur de l’immunité à médiation cellulaire antitumorale. Ils deviennent actifs grâce à la reconnaissance des peptides de 15 à 20 acides aminés dérivés d’antigènes tumoraux et présentés par les molécules HLA de classe II. Ils sont nécessaires à l’induction et la fonction des cellules effectrices dirigées contre les tumeurs notamment les lymphocytes T CD8 cytotoxiques (CTL). De plus la présence de lymphocytes CD4 Th1 infiltrant les tumeurs est souvent associée à un bon pronostic chez les patients. A l’aide d’un modèle in vitro chez l’homme et in vivo chez des souris transgéniques HLA, nous avons identifié quatre nouveaux peptides CD4 dérivés de la télomérase (TERT) un antigène de tumeur exprimé dans la majorité des cancers humains. Ces peptides appelés «Universal Cancer Peptide, UCP» se lient à la majorité des allèles HLA-DR et sont capables d’activer spécifiquement les LT CD4 de type-1. Des LT CD4 circulants spécifiques des UCP sont naturellement détectables dans plusieurs cancers humains mais absents chez des individus sains. Des clones T CD4 spécifiques des UCP générés à partir des lymphocytes de patients, produisent de forts taux d’IFN, TNF, et d’IL-2, cytokines associées à la polarisation Th1. L’analyse par ELISPOT IFN, de LT CD4 anti-UCP circulants au sein d’une cohorte de 84 patients atteints de cancers bronchiques métastatiques a montré la présence naturelle de ces lymphocytes chez 38 % des patients. De plus un effet bénéfique de la présence de cette réponse sur la survie globale a été observé chez les patients ayant une réponse clinique objective après chimiothérapie (13 vs 10 mois, P< 003). In vivo, l’immunisation de souris transgéniques HLA-A2/HLA-DR1 (Tg A2/DR1) avec les peptides UCP stimule des réponses T CD4 spécifiques caractérisées par une polarisation Th1. Nous avons montré que la présence in vivo de LT CD4 anti-UCP est nécessaire pour l’induction de réponses CTL antitumorales efficaces. Ainsi chez des souris co-immunisées en présence d’un peptide UCP, on observe un accroissement en nombre et de la qualité des réponses CTL proportionnellement à l’aide délivrée par les LT CD4 anti-UCP. L’induction de LT CD4 anti-UCP s’accompagne également d’une activation des cellules dendritiques in vivo via un mécanisme impliquant CD40L, IFN et GM-CSF. Dans un modèle de mélanome transplantable chez les souris Tg A2/DR1 nos résultats ont montré qu’une vaccination thérapeutique comportant un peptide UCP favorise un meilleur recrutement de CTL fonctionnels dans les tumeurs et améliore ainsi l’efficacité antitumorale du vaccin. Ces résultats confirment le rôle antitumoral majeur des lymphocytes CD4 Th1 et soulignent l’intérêt clinique de stimuler des réponses T CD4 spécifiques d’antigènes tumoraux de relevance clinique comme TERT. / Recent advances in immunology have now validated the concept of cancer immunosurveillance and the leading role of adaptative T cell immunity. Until a few years ago, antitumor CD8 T cell responses have been the most studied due to their direct cytotoxic activity on tumor cells. On the other hand, study of antitumor CD4 T cell responses are even more challenging because of the heterogeneity and plasticity of the various CD4 T cells subpopulations described. Among them, CD4 T helper type-1 cells (Th1), mainly characterized by the production of IFN, control the activation of antitumor cellular immunity. Thus, stimulation of specific CD4 Th1 cells may have a major interest for the development of anticancer immunotherapies. During this research thesis, we characterized novel HLA class II epitopes derived from a relevant tumor antigen, telomerase (TERT), and studied their capacities to stimulate specific CD4 Th1 cell responses. Using a method based on predictive immunology, we identified 4 peptides derived from TERT, referred as « Universal Cancer Peptides » (UCPs), enable to bind the most commonly found HLA-DR alleles in human. Using HLA-A2/HLA-DR1 transgenic mouse model, we first evaluated the in vivo immunogenicity of these peptides. Immunization of mice with UCPs induces high avidity specific CD4 T cells. The study of their polarization showed that UCP-specific CD4 T cells do not produce IL-4, -5, -10 or -17 cytokines, excluding a Th1, Treg or Th17 differentiation. In contrast, we measured high amount of IFN and IL-2 which characterize a Th1 pattern. The study of helper role allow us to demonstrate that CD8 peptide-based vaccinations in presence of UCPs enhance the efficacy of tumor specific CTL responses. Indeed, the intensity of these responses is strongly correlated with that of UCP-specific CD4 T cells induced in vivo. Furthermore, the stimulation of UCP-specific CD4 T cells promotes activation and IL-12 release by dendritic cells through a mechanism that involves IFN, GM-CSF and CD40L. We also demonstrated the antitumor efficacy of UCPs during a therapeutic vaccination in mice, as well as their capacity to foster the recruitment of specific CD8 T cells at the tumor site. In addition, the presence of naturally occurring UCP-specific CD4 T cell responses was found in different types of cancers such as leukemia, lung, colorectal or renal cancers. A study conducted in a cohort of 84 metastatic lung cancer patients revealed a synergistic effect of spontaneous UCP-specific CD4 Th1 and chemotherapy-treatment. Altogether, this study provides further evidences that stimulation of antitumor CD4 Th1 cells is a powerful method to improve cancer vaccines and also highlights the interest of TERT-derived UCPs for the innovative monitoring of antitumor CD4 T cell responses
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The creation of novel humanized mouse models for the assessment of innovative immunotherapies and vaccine evaluation / La création du modèle "HUMAMICE" : le développement de souris humanisée pour évaluation des innovations en biothérapies, immunothérapies et les thérapies cellulairesZeng, Yang 04 October 2018 (has links)
Les modèles animaux jouent un rôle crucial dans les recherches précliniques, mais il existe plusieurs limites. Les états physiologiques et immunologiques chez les murins et les primates non humains sont radicalement différents à ceux de l'homme, en particulier la restriction du CMH, qui ne peut éliminer l'influence de la spécificité de l'espèce dans les expériences précliniques. Le but du travail était de générer un niveau plus élevé de souris transgéniques «HLA humanisées» qui pourraient imiter les réponses immunitaires humaines avec plus de précision et de fiabilité; à viser d’appliquer pour l'évaluation préclinique de la transplantation humaine, à l'identification de nouveaux épitopes et à l'évaluation des vaccins et des médicaments candidats. Dans la première partie. Nous rapportons d’une nouvelles souris transgéniques HLA immunodéficientes «HUMAMICE». Des souris HLA-A2+/+/DR1+/+/H-2-β2m-/-/IAβ-/-/Rag2-/-/IL-2rγ-/-/Perf-/- ont été établies, lesquelles exprimaient des molécules HLA humaines au lieu de H-2 murines et ne présentaient pas de lymphocytes murins. Ce statut immunodéficient a été inversé en transférant les cellules hPBMC HLA appariées fonctionnelles pour produisant ensuite des souris ayant un statut immuno-compétent avec un système immunitaire humain fonctionnel. L'immunisation du vaccin HBsAg a permis d'obtenir une production robuste et reproductible d'anticorpsspécifiques. En conclusion, ces résultats indiquent que le modèle hPBMC-HUMAMICE représente un modèle prometteur pour disséquer les réponses immunitaires humaines aux maladies humaines. Dans la seconde partie de cette étude, les souris HLA-A11+/+/DR1+/+/H-2-β2m-/-/IAβ-/- ont été établies. Cette nouvelle souche de souris possède une caractéristique restreinte par HLA-A11 et une capacité normale à répondre aux antigènes. L'immunisation de souris avec un vaccin recombinant HBsAg contre le VHB ou une protéine recombinante du VIH-1 a entraîné la génération de lymphocytes T cytotoxiques producteurs d'IFN-y et d'anticorps spécifiques. En outre, nous avons identifié deux épitopes restreints par HLA-A11 de la protéine GP EBOV et quatre de la protéine MERS-CoV S. En fin, ce modèle de souris HLA-A11/DR1 pourra faciliter l'identification des épitopes de lymphocytes cytotoxiques et auxiliaires restreints par le HLA-A11 dominants en Chine. Le modèle constituer un nouvel outil technique prometteur pour comprendre les mécanismes immunologiques et les nouveaux vaccins pour les populations d’Asie de l’Est. Durant cette thèse, nous avons créé deux modèles de souris humanisées novateurs et prometteurs portant une restriction HLA humaine qui pourraient servir de modèles d'infection pathogène et étudier les tumeurs, les mécanismes de transplantation et l'invention et l'évaluation des vaccins et des médicaments. / Animal models play critical roles in pre-clinical researches, while there are still several limitations. The physiological and immunological states in murine and non-human primates are radically district from those of mankind, especially the MHC restriction, which cannot eliminate the influence of species specificity in pre-clinical experiments.The aim of our work was to generate a higher level of “humanized” transgenic mice which could mimic human immune responses with more accuracy and reliability; furthermore, to apply the novel models in the evaluation of human transplantation, the identification of new epitopes, and the evaluation of candidate vaccines and drugs.In the first part of the study, novel immuno-deficient HLA transgenic mice "HUMAMICE" (HLA-A2+/+/DR1+/+/ H-2-β2m-/-/IAβ-/-/Rag2-/-/IL-2rγ-/-/Perf-/- mice) were established, which expressed human HLA molecules instead of murine H-2 and present no murine lymphocytes. This immuno-deficient status was reversed by transferring the functional HLA-matched hPBMCs and then producing mice with an immuno-competent status with a functional human immune system, led to high lymphocytes engraftment rates without GvHD. Immunization of HBsAg vaccine resulted in robust and reproducible production of specific antibodies. Inconclusion, these results indicated that the hPBMCs-HUMAMICE model represents a promising model to dissect human immune responses towards human diseases.In the second part of this study, the Chinese/East Asian HLA dominated HLA-A11/DR1(HLA-A11+/+/DR1+/+/H-2-β2m-/-/IAβ-/-) transgenic mouse strain was established. This novel mouse strain possesses HLA-restricted characteristic and a normal ability to respond to antigens. Immunization of mice with a recombinant HBV vaccine or a recombinant HIV-1 protein resulted in the generation of IFN-γ-producing cytotoxic T lymphocytes and specific antibodies. Furthermore, we identified two HLA-A11 restricted epitopes of EBOV GP protein and four of MERS-CoV S protein. Above all, HLA-A11/DR1 mice could facilitate the identification of Chinese dominant HLA-restricted CTL and Th epitopes and provide a new promising technical tool to understand immunological mechanisms and new vaccines.Taken together, we created two novel and promising humanize mouse models carrying human HLA restriction which could apply as pathogen infection models, and study tumors, transplantation mechanism, and the invention and evaluation of vaccines and drugs.
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[en] IS COERCIVENESS AN ESSENTIAL PROPERTY OF LAW? / [pt] É A COERCITIVIDADE UMA PROPRIEDADE ESSENCIAL DO DIREITO?30 August 2018 (has links)
[pt] A coercitividade é sem dúvidas um dos elementos mais salientes do direito. Não só o direito ordena a realização de condutas, mas também faz ameaças e autoriza o uso da força para fazer cumprir as suas ordens. Impostos, taxas, sequestro de bens, cassação de direitos e o encarceramento são práticas presentes em todos sistemas jurídicos paradigmáticos. Apesar da saliência da coerção nos sistemas jurídicos, a grande maioria dos filósofos do direito contemporâneos pensa que a coercitividade não é uma propriedade essencial do direito, isto é, não é uma propriedade que está presente em todas as circunstâncias nas quais o direito existe. O argumento geralmente utilizado por esses filósofos é o de que é possível haver direito sem coerção, pois é possível haver uma circunstância na qual haja somente indivíduos cooperativos. Nessa circunstância a introdução da coerção se torna desnecessária, pois tais indivíduos seguem o direito a despeito da coerção. Neste trabalho defendo que uma versão do argumento normalmente utilizado para defender essa tese - o argumento dos homens perplexos - não funciona. As objeções apresentadas pretendem mostrar que há coerção em uma circunstância na qual só existem homens perplexos e também que a instituição existente nessa circunstância não é uma instância genuína de direito. No curso deste trabalho esclareço o que é o homem perplexo e também faço algumas considerações sobre a coerção visando a dispersar algumas confusões. / [en] Coerciveness is doubtlessly one of law s most salient elements. Law not only orders the performance of conducts, but also makes threats and authorizes the use of force to enforce its orders. Taxes, fees, restraint of assets, revocation of rights and imprisonment are existing practices in all paradigmatic legal systems. Despite the salience of coercion in all legal systems, the great majority of contemporary legal philosophers think that coerciveness is not an essential property of law, that is, it is not a property present in all circumstances in which law exists. The argument normally used by those philosophers is that it is possible to have law without coercion, because it is possible to have a circumstance composed solely by cooperative subjects. In this circumstance, the introduction of coercion becomes unnecessary, for such subjects follow the law regardless of coercion. In this work, I argue that one version of the argument normally used by those philosophers to defend this thesis - the puzzled men argument - does not
work. The objections presented aim to show that there is coercion in a circumstance composed solely by puzzled men, and that the existing institution in this circumstance is not a genuine instance of law. During this work, I clarify what the puzzled man is and make some considerations about coercion aiming to
dispel some confusions.
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Etude de la réponse des lymphocytes T spécifiques de l’hormone humaine H2-relaxine et de modifications non-naturelles : perspectives pour la réduction de l’immunogénicité des protéines et peptides thérapeutiques / Study of the response of human hormone H2-relaxin-specific T-cells and non-natural modifications : perspectives for the reduction of the immunogenicity of therapeutic proteins and peptidesAzam, Aurélien 14 June 2018 (has links)
Ce projet a accompagné le développement pré-clinique de l'hormone humaine Relaxine-2 (Rln2) ayant induit des anticorps durant des essais cliniques, il est axée autour de 2 problématiques : (1) comprendre son immunogénicité, (2) étudier l’impact de modifications chimiques sur l’immunogénicité afin d'augmenter sa stabilité.Compte tenu du rôle des lymphocytes T CD4 dans les réponses immunitaires, la fréquence de cellules T spécifiques de la Rln2 dans un large panel de donneurs sains a été estimée et a permis d’expliquer le développement d’anticorps anti-Rln2. La cartographie des épitopes T a ensuite identifié les zones portant son immunogénicité. Puis, 6 modifications chimiques (acide aminé D, acide aminé isobutyrique, peptoïde, N-méthylation, C-méthylation et réduction de la liaison peptidique) utilisées pour augmenter la demi-vie ont été introduites à la plupart des positions d’un peptide hautement immunogène. La reconnaissance par des cellules T, la liaison aux molécules de présentation et la capacité à induire des lymphocytes T CD4 ont été étudiées pour les peptides analogues modifiés. La plupart des modifications se sont révélées être très efficaces pour minimiser les propriétés immunogéniques.Ce projet de thèse se situe donc à la croisée des chemins entre l’acquisition de connaissances nouvelles en immunologie et leur application dans des processus de conception et de gestion des risques de peptides thérapeutiques. / This project has accompanied the pre-clinical development of the human hormone Relaxin-2 (Rln2) that induced antibodies during clinical trials, it focuses on two issues: (1) to understand its immunogenicity, (2) to study the impact of unnatural modifications on immunogenicity to increase its stability.Given the role of CD4 T-cells in immune responses, the frequency of Rln2-specific T-cells in a large panel of healthy donors was estimated, and explained the development of anti-Rln2 antibodies. The T epitope mapping then identified the areas responsible for its immunogenicity. Then, 6 unnatural modifications (D amino acid, amino isobutyric acid, peptoid, N-methylation, C-methylation & reduced peptide bond) used to increase the half-life were introduced at most positions of a highly immunogenic peptide. T-cell recognition, binding to HLA molecules and the ability to induce CD4 T-cells were studied for modified analog peptides. Most of the modifications were very effective in minimizing immunogenic properties.This thesis project is at the crossroads between the acquisition of new knowledge in immunology and its application in the process of design & risk management of therapeutic peptides.
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La drosophile transgénique HLA-B27 : un nouveau modèle pour l'étude des spondyloarthrites / The transgenic Drosophila HLA-B27 : a new model for the study of spondyloarthritisGrandon, Benjamin 15 October 2018 (has links)
Les spondyloarthrites (SpA) sont des maladies inflammatoires chroniques articulaires qui se caractérisent par des atteintes de la colonne vertébrale et des articulations périphériques, en particulier des enthèses, souvent associées à des manifestations extra-articulaires telles que le psoriasis, l’uvéite, ou l’inflammation intestinale. Ces maladies complexes possèdent une forte composante génétique dominée par l'antigène HLA-B27 du complexe majeur d'histocompatibilité de classe I (CMH-I), présent chez plus de 80% des patients atteints de SpA. Découverte il y a 45 ans, l'association entre HLA-B27 et le développement des SpA reste inexpliquée. Plusieurs hypothèses ont été proposées pour expliquer cette association au niveau moléculaire. Cependant, la plupart se heurtent à des incohérences expérimentales qui semblent les invalider. Pour élucider les mécanismes moléculaires pathogènes liés au HLA-B27, nous avons utilisé une nouvelle approche. Drosophila melanogaster est un puissant modèle génétique qui a permis des avancées considérables dans la compréhension de nombreuses fonctions des cellules de métazoaires, ainsi que dans la description des processus cellulaires et moléculaires de nombreuses pathologies humaines. Nous avons établi plusieurs lignées de drosophiles transgéniques pour des formes d’HLA-B associées aux SpA ou pour une forme non associée à la maladie, ainsi que pour la chaîne invariante du CMH-I, la β2m humaine (hβ2m). L'expression des formes associées à la maladie, exclusivement en présence de la hβ2m, dans l'aile et dans l'œil de la drosophile conduit à l'apparition de deux phénotypes spécifiques. Mes résultats ont permis de mettre en évidence que le phénotype de perte des veines transversales de l’aile était associé à une perturbation de la signalisation par la voie des Bone Morphogenetic Protein (BMP). Cette perturbation est associée à une co-localisation de HLA-B27 avec le récepteur BMP de type I, Sax. Nos résultats préliminaires obtenus dans les cellules de patients atteints de SpA suggèrent l’existence d’une co-localisation analogue d’HLA-B27 avec le récepteur ALK2, orthologue de Sax. L'ensemble de nos résultats plaide en faveur d’un rôle pathogène de HLA-B27 passant par une dérégulation de la voie BMP à l’intersection des voies de l’ossification et de l’inflammation et pourrait donc s’appliquer à la physiopathologie des SpA. / Spondyloarthritis (SpA) is a chronic inflammatory rheumatic disorder characterized by joint manifestations affecting the spine, peripheral joints and entheses, as well as extra-articular manifestations such as psoriasis, uveitis, or intestinal inflammation. This complex disorder has a strong genetic component dominated by the HLA-B27 antigen of the major histocompatibility complex class I (MHC-I), which is present in more than 80% of SpA patients. Discovered 45 years ago, the association between HLA-B27 and SpA development remains unexplained. Several hypotheses have been proposed to explain this association at the molecular level, but all face experimental inconsistencies that seem to invalidate them. Therefore, it appeared to us essential to elaborate new and yet unexplored approaches in order to better understand the molecular role of HLA-B27 in SpA development. Drosophila melanogaster is a powerful genetic model that has led to considerable advances in understanding numerous functions of metazoan cells, as well as in describing the cellular and molecular processes of many human pathologies. To elucidate the molecular pathogenic mechanisms associated with HLA-B27, we have established several transgenic Drosophila lines for SpA-associated and non-associated of HLA-B alleles, as well as for the MHC-I invariant chain, the human 2-microglobulin (hβ2m). Expression of the HLA-B27 alleles, in the presence of hβ2m, in the Drosophila wing and eye led to two specific phenotypes. The crossveinless wing phenotype is due to a disturbance in the Bone Morphogenetic Protein (BMP) signaling pathway. Interestingly, this misregulation is associated with a co-localization of HLA-B27 and the BMP type I receptor named Sax. Our preliminary results obtained in SpA patient cells suggest that HLA-B27 also colocalizes with ALK2 receptor, which is ortholog to Sax. Altogether, our results suggest that the pathogenic role of HLA-B27 in SpA may depend on a BMP signaling misregulation at the crosstalk between ossification and inflammation.
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Presentation of insulin granule-derived peptides on HLA in Enterovirus-infected beta cells and type 1 diabetesMarinicova, Zuzana 11 September 2023 (has links)
Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by loss of insulin-producing beta cells resulting in life-long insulin deficiency. Beta cell destruction by autoreactive CD8+ effector T-cells is thought to be the main cause of loss of insulin output. Autoreactive T-cells are similarly to autoantibodies, which have been established as markers of risk and progression of the disease, directed towards autoantigens of T1D. These are most notably, insulin, 65 kDa glutamic acid decarboxylase (GAD65, also known as GAD2), insulinoma-associated protein 2 (IA2, also known as PTPRN or ICA512) or zinc transporter 8 (ZNT8). Most of the known T1D autoantigens are components of insulin secretory granules (SGs). T1D arises from an interplay of genetic and environmental factors, which are thought to act as triggers in susceptible individuals. Predisposing alleles in genetic loci for human leukocyte antigen (HLA) account for by far the highest contribution to the risk of disease development, followed by an array of polymorphisms thought to play a role in either immune cells or beta cells. Of environmental factors that potentially add to the risk of disease progression, the most evidence-supported are Enteroviruses (EVs). Most notably, their genome and viral proteins, as well as higher expression of cellular proteins involved in viral response were detected more often in blood and pancreata of patients with T1D than in healthy population. In addition, recent evidence from a large long-term observational study has implicated prolonged shedding of specifically species Enterovirus B in the stools of children as a risk factor in development of beta cell autoimmunity in children with high genetic risk of T1D. For these reasons, many researchers have studied the potential mechanisms of EV involvement in T1D pathogenesis. In our laboratory, we have investigated the effects of coxsackievirus B5 (CVB5) infection on murine insulinoma MIN6 cells. Previously, we have reported that glucose-stimulated translation of SG proteins can be carried out in a cap-independent manner and is not shut down as part of the early effects of CVB5 infection on MIN6 cells. We have also observed that mature forms of SG proteins are being degraded during viral infection. As intracellular protein degradation is one of the major pathways to supply peptides for presentation on HLA I for immune recognition, we hypothesized that concomitant production and degradation of SG proteins upon viral infection could lead to altered presentation of mainly peptides derived from insulin SG component proteins and potentially drive the response of autoreactive T-cells. To address this hypothesis, we aimed to identify appropriate conditions to study the impact of EV infection on antigen presentation of ECN90 cells. To that end, we established a panel of markers examined by SDS-PAGE and immunoblotting. Stage of viral infection was assessed based on the detection of the viral protein VP1 and cleavage of cellular factors such as eukaryotic translation initiation factor 4 G (eIF4G), poly(A)-binding protein (PABP1), polypyrimidine tract-binding protein 1 (PTBP1), poly (ADP-ribose) polymerase (PARP) and caspase 3, which is mediated by viral proteases. Furthermore, we assessed the levels of ICA512 and chromogranin A and their pro-forms to estimate the size of insulin SG stores, and the expression of HLA I and β2 microglobulin to confirm sufficient antigen presentation. Peptides presented on both HLA I and II were isolated by immunoaffinity purification and identified by liquid chromatography-tandem mass spectrometry analysis. About 500 unique HLA I-presented peptides were found on average per replicate and condition with purity of 89% (peptides predicted to bind HLA alleles expressed by ECN90 cells). The distribution of unique peptides presented by infected ECN90 cells significantly differed from those presented by control cells as 54 unique peptides were present only in all infected samples and none of uninfected and 13 peptides were only found in uninfected cells. In total, we identified 26 unique peptides from known T1D autoantigens associated with SGs (e.g. insulin, chromogranin A, ICA512) in both conditions. The majority of them were predicted to bind HLA I alleles B*40:01 and A*02:01, while two identified viral peptides were found to bind B*40:01 and A*03:01 alleles. Both of the viral peptides and almost half of the peptides originating from known T1D autoantigens have not been described before. In addition, on average 300 unique HLA II peptides were found per replicate and condition. Similarly to HLA I peptides, the distribution of unique peptides across infected and control cells differed as well, showing that antigen presentation was altered in infected cells. We identified two viral HLA II-eluted peptides and peptides originating from only two known T1D autoantigens, 35 originated from insulin and 157 from chromogranin A. As most of the newly identified HLA I peptides originating from T1D autoantigens and one peptide from viral proteins were restricted by the allele HLA-B*40:01, our further efforts were invested in the development of a recombinant disulfide-stabilized biotinylated peptide-receptive HLA molecule of this allele. This technology has been extensively validated, and will allow us to test the wide array of novel peptides identified by us for the ability to bind this allele, as well as asses frequencies and responses of specific T-cells in subject populations relevant for T1D.
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Jämförelse och utvärdering av FastQ B*27 direct och LAMP Human HLA-B27 direct detection KIT för HLA-B27 allel detektion : Två kit utvärderas mot nuvarande metod på Länssjukhuset Ryhov för utbyte av rutindiagnostik / Comparison and evaluation of FastQ B*27 direct and LAMP Human HLA-B27 direct detection KIT for HLA-B27 allele detectionSollerbrant, Hanna, Suleiman, Joude January 2024 (has links)
Autoimmunitet är ett tillstånd där kroppens immunsystem felaktigt attackerar och skadar sina egna vävnader och celler. HLA-B27 är en genvariation som kan kopplas till autoimmun sjukdom som ankyloserande spondylit med en prevalens på 2-4% i världens befolkning. Denna studie syftade till att utvärdera och jämföra två kit för HLA-B27 alleler mot den nuvarande metoden på Länssjukhuset Ryhov i Region Jönköpings län. De metodprinciper som användes var realtids-PCR samt LAMP. Totalt analyserades 37 avidentifierade blodprover med vardera av kiten samt med nuvarande metod. Resultatet visade en överensstämmelse med avseende på förväntade positiva och negativa resultat för HLA-B27 för de två kiten jämfört med nuvarande metoden. De tre metoderna/kiten detekterar de vanligaste HLA-B27 allelerna. Utifrån studiens resultat visade sig båda kiten vara effektiva, lättanvända samt ha stabila reagenser. Dessutom uppnådde båda kiten de IVD-krav som ställs inom EU. / Autoimmunity is a condition where the body's immune system mistakenly attacks and damages its own tissues and cells. HLA-B27 is a genetic variation that can be linked to autoimmune diseases such as ankylosing spondylitis, with a prevalence of 2-4% in the world’s population. This study aimed to evaluate and compare two kits for HLA-B27 alleles against the current method at Ryhov County Hospital in Region Jönköping County. The methodological principles used were real-time PCR and LAMP. A total of 37 anonymized blood samples were analyzed using each of the kits and the routine method. The results showed concordance with the expected positive and negative results for HLA-B27 between the two kits compared to the current method. The three methods/kits detect the most common HLA-B27 alleles. Based on the study’s results, both kits proved to be effective, user friendly, and have stable reagents. Additionally, both kits met the IVD requirements set within the EU.
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Development of a Surface-to-Air Missile T&E FederationLucas, Jason L., Kent, Robert A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper focuses on the development of the Surface-to-Air Missile Federation (SAM Fed), a Test and Evaluation (T&E) High Level Architecture (HLA) federation. The SAM Fed evolved from a legacy constructive real time/post mission hardware-in-the-loop (HITL) Surface-to-Air Missile (SAM) simulation. The process to transition from a standalone simulation to a distributed HLA federation as well as the problems experienced and lessons learned will be presented. This paper will also discuss the merit of standardizing internal federate interfaces to facilitate reuse.
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A correlation of genotype and phenotype in myositisChinoy, Hector January 2007 (has links)
Aims: To elucidate the aetiopathological mechanisms underlying the IIMs, through a combination of genotyping, serotyping and clinical phenotyping in a large cohort of Caucasian idiopathic inflammatory myopathy (IIM) patients. Methods: A cross-sectional study of prevalent IIM cases, ascertained through the Adult Onset Myositis Immunogenetic Collaboration, was performed. Cases were confirmed as possessing myositis according to Bohan and Peter (Bohan and Peter 1975a; Bohan and Peter 1975b). IIM clinical subtypes studied included polymyositis (PM), dermatomyositis (DM) and myositis associated with other connective tissue disease (myositis/CTD-overlap). Genotyping of major histocompatibility complex genes, including HLA-B, -DR, -DQ, tumour necrosis factor alpha (TNF-α), was performed using commercial kits. Serotyping of a comprehensive range of myositis specific/associated antibodies (MSA/MAAs) was undertaken. Results: Clinical subsets are described within the serological groupings, suggesting that the classification of the IIMs appears to be better served by the serotype than by the clinical subgrouping of disease. The IIMs possess HLA class I and II haplotype associations and genetic differences observed between PM and DM are accounted for by serological differences. The TNF-308A association is not independent of HLA class I, due to the strong LD within the MHC, but does form part of a haplotype with these factors. An absence of routinely tested for MSA/MAAs makes cancer associated myositis (CAM) more likely, especially in the DM subgroup. An antibody against a 155 and 140kDa doublet is associated with the development of CAM. Outcome measures in the IIMs show construct validity. HLA-DRB1*07 appears to predict a milder clinical phenotype with less disability. No convincing gene-environmental interaction was found capable of altering disease susceptibility or clinical phenotype. Conclusions: Myositis disease subtypes therefore appear to be defined by specific haplotypes acting as risk factors for the development of various MSAs and MAAs.
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