89 research outputs found

    Prevention of “Humanized” Diabetogenic CD8 T-Cell Responses in HLA-Transgenic NOD Mice by a Multipeptide Coupled-Cell Approach

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    OBJECTIVE: Type 1 diabetes can be inhibited in standard NOD mice by autoantigen-specific immunotherapy targeting pathogenic CD8+ T-cells. NOD.beta2m(null).HHD mice expressing human HLA-A2.1 but lacking murine major histocompatibility complex class I molecules develop diabetes characterized by CD8 T-cells recognizing certain autoantigenic peptides also targeted in human patients. These include peptides derived from the pancreatic beta-cell proteins insulin (INS1/2 A(2-10) and INS1 B(5-14)) and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP(265-273) and IGRP(228-236)). Hence, NOD.beta2m(null).HHD mice represent a model system for developing potentially clinically translatable interventions for suppressing diabetogenic HLA-A2.1-restricted T-cell responses. RESEARCH DESIGN AND METHODS: Starting at 4-6 weeks of age, NOD.beta2m(null).HHD female mice were injected intravenously with syngeneic splenocytes to which various admixtures of the four above-mentioned peptides were bound by the cross-linking agent ethylene carbodiimide (ECDI). RESULTS: Treatment with such cells bearing the complete cocktail of INS and IGRP epitopes (designated INS/IGRP-SPs) significantly inhibited diabetes development in NOD.beta2m(null).HHD recipients compared with controls receiving splenocytes coupled with an irrelevant HLA-A2.1-restricted Flu16 peptide. Subsequent analyses found syngeneic splenocytes bearing the combination of the two ECDI-coupled IGRPs but not INS peptides (IGRP-SPs or INS-SPs) effectively inhibited diabetes development in NOD.beta2m(null).HHD mice. This result was supported by enzyme-linked immunospot (ELISPOT) analyses indicating combined INS/IGRP-SPs diminished HLA-A2.1-restricted IGRP but not INS autoreactive CD8+ T-cell responses in NOD.beta2m(null).HHD mice. CONCLUSIONS: These data support the potential of a cell therapy approach targeting HLA-A2.1-restricted IGRP autoreactive CD8 T-cells as a diabetes intervention approach in appropriate human patients

    The effect of exercise training on the course of cardiac troponin T and i levels: Three independent training studies

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    With the introduction of high-sensitive assays, cardiac troponins became potential biomarkers for risk stratification and prognostic medicine. Observational studies have reported an inverse association between physical activity and basal cardiac troponin levels. However, causality has never been demonstrated. This study investigated whether basal cardiac troponin concentrations are receptive to lifestyle interventions such as exercise training. Basal high-sensitive cardiac troponin T ( cTnT ) and I ( cTnI ) were monitored in two resistance-type exercise training programs ( 12-week ( study 1 ) and 24-week ( study 2 ) ) in older adults ( ≥65 years ). In addition, a retrospective analysis for high sensitive troponin I in a 24-week exercise controlled trial in ( pre )frail older adults was performed ( study 3 ). In total, 91 subjects were included in the final data analyses. There were no significant changes in cardiac troponin levels over time in study 1 and 2 ( study 1: cTnT −0.13 ( −0.33–+0.08 ) ng/L/12-weeks, cTnI −0.10 ( −0.33–+0.12 ) ng/L/12-weeks; study 2: cTnT −1.99 ( −4.79–+0.81 ) ng/L/24-weeks, cTnI −1.59 ( −5.70–+2.51 ) ng/L/24-weeks ). Neither was there a significant interaction between training and the course of cardiac troponin in study 3 ( p = 0.27 ). In conclusion, this study provides no evidence that prolonged resistance-type exercise training can modulate basal cardiac troponin levels

    HLA-A*02:07 Is a Protective Allele for EBV Negative and a Susceptibility Allele for EBV Positive Classical Hodgkin Lymphoma in China

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    HLA-A2 protects from EBV+ classical Hodgkin lymphoma (cHL) in Western Europe, but it is unknown whether this protective effect also exists in the Chinese population. We investigated the association of HLA-A2 and specific common and well documented HLA-A2 subtypes with EBV stratified cHL patients (n = 161) from the northern part of China. Quantitative-PCR and sequence-based subtyping was performed to identify HLA-A2 positive samples and their subtypes. 67 (42%) of the cHL patients were EBV+. There were no significant differences in percentages of HLA-A2 positivity between cHL and controls (65% vs 66%) and between EBV+ and EBV− cHL patients (70% vs 61%). The frequency distribution of HLA-A2 subtypes was significantly different between EBV stratified cHL subgroups and controls. This difference was most striking for the HLA-A*02:07 type with a frequency of 38% in EBV+ cHL, 8% in EBV− cHL and 20% in controls. Significant differences were also observed for the HLA-A*02:07, HLA-A2 (non-02:07) and the A2-negative typings between EBV+ cHL vs controls (p = 0.028), EBV− cHL vs controls (p = 0.045) and EBV+ vs EBV− cHL cases (p = 2×10−5). In conclusion, HLA-A*02:07 is a predisposing allele for EBV+ cHL and a protective allele for EBV− cHL in the northern Chinese population

    Discriminating lymphomas and reactive lymphadenopathy in lymph node biopsies by gene expression profiling

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    <p>Abstract</p> <p>Background</p> <p>Diagnostic accuracy of lymphoma, a heterogeneous cancer, is essential for patient management. Several ancillary tests including immunophenotyping, and sometimes cytogenetics and PCR are required to aid histological diagnosis. In this proof of principle study, gene expression microarray was evaluated as a single platform test in the differential diagnosis of common lymphoma subtypes and reactive lymphadenopathy (RL) in lymph node biopsies.</p> <p>Methods</p> <p>116 lymph node biopsies diagnosed as RL, classical Hodgkin lymphoma (cHL), diffuse large B cell lymphoma (DLBCL) or follicular lymphoma (FL) were assayed by mRNA microarray. Three supervised classification strategies (global multi-class, local binary-class and global binary-class classifications) using diagonal linear discriminant analysis was performed on training sets of array data and the classification error rates calculated by leave one out cross-validation. The independent error rate was then evaluated by testing the identified gene classifiers on an independent (test) set of array data.</p> <p>Results</p> <p>The binary classifications provided prediction accuracies, between a subtype of interest and the remaining samples, of 88.5%, 82.8%, 82.8% and 80.0% for FL, cHL, DLBCL, and RL respectively. Identified gene classifiers include LIM domain only-2 (<it>LMO2</it>), Chemokine (C-C motif) ligand 22 (<it>CCL22</it>) and Cyclin-dependent kinase inhibitor-3 (<it>CDK3</it>) specifically for FL, cHL and DLBCL subtypes respectively.</p> <p>Conclusions</p> <p>This study highlights the ability of gene expression profiling to distinguish lymphoma from reactive conditions and classify the major subtypes of lymphoma in a diagnostic setting. A cost-effective single platform "mini-chip" assay could, in principle, be developed to aid the quick diagnosis of lymph node biopsies with the potential to incorporate other pathological entities into such an assay.</p

    Islet-Specific CTL Cloned from a Type 1 Diabetes Patient Cause Beta-Cell Destruction after Engraftment into HLAA2 Transgenic NOD/SCID/IL2RG Null Mice

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    Despite increasing evidence that autoreactive CD8 T-cells are involved in both the initiation of type 1 diabetes (T1D) and the destruction of beta-cells, direct evidence for their destructive role in-vivo is lacking. To address a destructive role for autoreactive CD8 T-cells in human disease, we assessed the pathogenicity of a CD8 T-cell clone derived from a T1D donor and specific for an HLA-A2-restricted epitope of islet-specific glucose-6-phosphatase catalytic-subunit related protein (IGRP). HLA-A2/IGRP tetramer staining revealed a higher frequency of IGRP-specific CD8 T-cells in the peripheral blood of recent onset human individuals than of healthy donors. IGRP(265-273)-specific CD8 T-cells that were cloned from the peripheral blood of a recent onset T1D individual were shown to secrete IFNγ and Granzyme B after antigen-specific activation and lyse HLA-A2-expressing murine islets in-vitro. Lytic capacity was also demonstrated in-vivo by specific killing of peptide-pulsed target cells. Using the HLA-A2 NOD-scid IL2rγ(null) mouse model, HLA-A2-restricted IGRP-specific CD8 T-cells induced a destructive insulitis. Together, this is the first evidence that human HLA-restricted autoreactive CD8 T-cells target HLA-expressing beta-cells in-vivo, demonstrating the translational value of humanized mice to study mechanisms of disease and therapeutic intervention strategies

    L'éducation à la citoyenneté dans des contextes de division: les défis au Québec et en Irlande du Nord

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    Ce texte propose un examen des particularités de la citoyenneté et de l’éducation à la citoyenneté au Québec et en Irlande du Nord, en comparant les concepts clés et les cadres théoriques qui sous-tendent l’éducation à la citoyenneté dans ces deux sociétés divisées dont l’une peut être décrite comme relativement paisible, et l’autre, comme se dégageant lentement d’un climat de violence politique. Les auteures examinent les théories pertinentes suivant une démarche multidisciplinaire pour cerner le concept de citoyenneté dans des sociétés où l’identité nationale fait l’objet de divergences de vues plus ou moins marquées. À partir de la documentation scientifique et de recherches antérieures, les auteures tentent de déterminer dans quelle mesure diverses dimensions de la citoyenneté trouvent écho dans les initiatives pédagogiques dans les deux sociétés étudiées. Elles examinent et comparent les programmes d’éducation à la citoyenneté dans les deux sociétés pour cerner les différences et les ressemblances entre les mesures éducatives prises pour promouvoir la citoyenneté et les relations communautaires paisibles dans l’une et l’autre société. Enfin, les auteures analysent le sens de la citoyenneté et la valeur de l’éducation à la citoyenneté aux fins de la stabilité sociale et politique dans des sociétés divisées.This article examines the characteristics of citizenship and citizenship education in Québec and Northern Ireland by comparing the key concepts and theoretical frameworks underlying citizenship education in these two divided societies, one of which can be relatively peaceful and the other slowly recovering from a climate of political violence. The authors use a multi-disciplinary process to examine relevant theories in order to identify the concept of citizenship in societies where the national identity is subject to varying degrees of division. Using existing scientific documentation, the authors attempt to determine the extent to which different dimensions of citizenship are reflected in the pedagogical initiatives of the two societies being studied. They examine and compare citizenship education programs in both societies to identify the similarities and differences in educational measures for promoting citizenship and peaceful community relations in each society. Finally, the authors analyse the meaning of citizenship and the value of citizenship education in divided societies for purposes of social and political stability.Este texto propone un examen de las particularidades de la ciudadanía y de la educación a la ciudadanía en Quebec y en Irlanda del Norte, comparando los conceptos clave y los cuadros teóricos subyacentes a la educación a la ciudadanía en esas dos sociedades divididas, una relativamente en paz, la otra alejándose lentamente de un clima de violencia política. Las autoras examinan las teorías pertinentes siguiendo un enfoque multidisciplinario con el fin de circunscribir el concepto de ciudadanía en sociedades en donde la identidad nacional es objeto de divergencias más o menos marcadas. A partir de la documentación científica y de investigaciones anteriores, las autoras tratan de determinar en qué medida las diversas dimensiones de la ciudadanía tiene un eco en las iniciativas pedagógicas en las dos sociedades estudiadas. Examinan y comparan los programas de educación a la ciudadanía en las dos sociedades con el fin de identificar diferencias y similitudes entre las medidas educativas adoptadas para promover la ciudadanía y las relaciones comunitarias pacíficas en dichas sociedades. Finalmente, las autoras analizan el significado de la ciudadanía y el valor de la educación a la ciudadanía para la estabilidad social y política en sociedades divididas
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