T Cells Recognizing a Peptide Contaminant Undetectable by Mass Spectrometry

Synthetic peptides are widely used in immunological research as epitopes to stimulate their cognate T cells. These preparations are never completely pure, but trace contaminants are commonly revealed by mass spectrometry quality controls. In an effort to characterize novel major histocompatibility complex (MHC) Class I-restricted β-cell epitopes in non-obese diabetic (NOD) mice, we identified islet-infiltrating CD8+ T cells recognizing a contaminating peptide. The amount of this contaminant was so small to be undetectable by direct mass spectrometry. Only after concentration by liquid chromatography, we observed a mass peak corresponding to an immunodominant islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)206-214 epitope described in the literature. Generation of CD8+ T-cell clones recognizing IGRP206-214 using a novel method confirmed the identity of the contaminant, further underlining the immunodominance of IGRP206-214. If left undetected, minute impurities in synthetic peptide preparations may thus give spurious results

Front Behav Neurosci

Cognitive impairment in Down syndrome (DS) has been linked to increased synaptic inhibition. The underlying mechanisms remain unknown, but memory deficits are rescued in DS mouse models by drugs targeting GABA receptors. Similarly, administration of epigallocatechin gallate (EGCG)-containing extracts rescues cognitive phenotypes in Ts65Dn mice, potentially through GABA pathway. Some developmental and cognitive alterations have been traced to increased expression of the serine-threonine kinase DYRK1A on Hsa21. To better understand excitation/inhibition balance in DS, we investigated the consequences of long-term (1-month) treatment with EGCG-containing extracts in adult mBACtgDyrk1a mice that overexpress Dyrk1a. Administration of POL60 rescued components of GABAergic and glutamatergic pathways in cortex and hippocampus but not cerebellum. An intermediate dose (60 mg/kg) of decaffeinated green tea extract (MGTE) acted on components of both GABAergic and glutamatergic pathways and rescued behavioral deficits as demonstrated on the alternating paradigm, but did not rescue protein level of GABA-synthesizing GAD67. These results indicate that excessive synaptic inhibition in people with DS may be attributable, in large part, to increased DYRK1A dosage. Thus, controlling the level of active DYRK1A is a clear issue for DS therapy. This study also defines a panel of synaptic markers for further characterization of DS treatments in murine models

Sélection, identification et caractérisation partielle d'antigènes du spermatozoïde du renard (Vulpes vulpes) en vue de leur utilisation dans un vaccin contraceptif

The aim of this work was to identify antigenic proteins on fox (Vulpes vulpes) spermatozoa, in order to develop a contraceptive vaccine. First, we obtained antisera directed against sperm surface proteins dy rabbit and fox immunisation, and by fox vasectomy. Using this sera for Western blotting, 7 highly antigenic proteins were selected. They were named P3, P4, P5, P8, P11 and P13. Out of these 7 proteins, 6 were microsequenced dy using Edman chemistry. Then, we obtained the cDNA encoding the 6 antigens by using RACE PCR or RT-PCR. Two PCR products were used as probes for the screening of a fox testis cDNA library realised in our lab. This manuscript describe a strategy which allowed the selection and the identification of sperm antigens. Many studies are necessary in order to determine the full sequence and properties of these antigens. The determination of specific epitopes and of adapted delivery system could allows their use in a contraceptive vaccine.L'objectif de ce travail est d'identifier des antigènes du spermatozoïde de renard (Vulpes vulpes), en vue de leur utilisation dans un vaccin contraceptif. Pour cela, nous avons produit des sérums reconnaissant des protéïnes de surface du spermatozoïde par immunisation de lapins et de renards et par vasectomie de renards. Ces sérums nous ont permis de sélectionner par Western blot 7 protéines particulièrement antigéniques, nommées P3, P4, P5, P8, P11 et P13. Le séquençages NH2 terminal de 6 de ces protéines a été réalisé, puis des fragments de l'ADN codant ces antigènes ont été amplifiés par RACE ou RT-PCR. Deux de ces fragments ont été utilisés comme sonde pour le criblage d'une banque d'ADNc de testicule de renard, que nous avons réalisée, permettant le séquençage de l'ADN codant les antigènes P8 et P13. Afin de caractériser ces antigènes, des sérums polyclonaux monospécifiques ont été produits chez la souris, permettant pour la protéine P5 l'étude de la spécificité d'espèce, de la spécificité d'organe, son immunolocalisation, et l'évaluation de l'effet des anticorps sur la mobilité des spermatozoïdes et sur la liaison à la zone pellucide. D'autre part, la caractérisation biochimique (recherche de glycosylation) a été réalisée pour les 7 antigènes. Les protéines P4 et P8 présentent de fortes homologies avec des protéines mitochondriales, respectivement la NADH deshydrogénase et la cytochrome-C oxydase. P13 présente une forte homologie avec la protéine spermatique humaine fibrousheatin 2. Les antigènes P3 et P7 sont des glycoprotéines dont la séquence déterminée par RACE PCR ne présente pas d'homologie importante avec des protéines connues, mais suggère qu'elles pourraient avoir une localisation membranaire. Le sérum dirigé contre la glycoprotéine P5 a permis d'établir que cette protéine inconnue ne semble pas spécifique d'espèce ou d'organe, mais que les anticorps dirigés contre cette protéine réduisent la liaison des spermatozoïdes à la zone pellicule. Ce travail présente une strarégie ayant permis la sélection et l'identification d'antigènes psermatiques. Différentes études ont encore nécessaires pour déterminer la séquence et les propriétés de ces antigènes. la recherche d'épitopes spécifiques et d'une formulation vaccinale adaptée pourrait permettre leur utilisation dans un vaccin contraceptif

Sélection, identification et caractérisation partielle d'antigènes du spermatozoïde du renard (Vulpes vulpes) en vue de leur utilisation dans un vaccin contraceptif

NANCY1-SCD Medecine (545472101) / SudocSudocFranceF

Perspectives on Cultural Integration of Immigrants

Chapitre 1This introduction, building on the recent economics of cultural transmission, introduces the main conceptual issues which are of relevance to the study of the cultural integration patterns of immigrants and of their interaction with market and non-market outcomes. More specifically, this chapter briefly discusses the different theories of cultural integration developed in the social sciences. This chapter documents in more detail the economic approach to the study of cultural integration and discuss the consequences of cultural integration in terms of its socio-economic impact on host countries

Cultural Integration of Immigrants in Europe

The concepts of cultural diversity and cultural identity are at the forefront of the political debate in many western societies. In Europe, the discussion is stimulated by the political pressures associated with immigration flows, which are increasing in many European countries. The imperatives that current immigration trends impose on European democracies bring to light a number of issues that need to be addressed. What are the patterns and dynamics of cultural integration? How do they differ across immigrants of different ethnic groups and religious faiths? How do they differ across host societies? What are the implications and consequences for market outcomes and public policy? Which kind of institutional contexts are more or less likely to accommodate the cultural integration of immigrants? All these questions are crucial for policy makers and await answers. This book aims to provide a stepping stone to the debate. Taking an economic perspective, this edited book presents a current, comparative picture of the process of cultural integration of immigrants across Europe. It documents the main economic debates on the causes and consequences of cultural integration of immigrants, and provides detailed descriptions of the cultural and economic integration process in seven main European countries, including France, Germany, Italy, Spain, Sweden, Switzerland, and the United Kingdom. It also compares the European context with the integration of immigrants in the United States. (Publisher's abstract

Cultural integration of immigrants in Europe

The concepts of cultural diversity and cultural identity are at the forefront of the political debate in many western societies. In Europe, the discussion is stimulated by the political pressures associated with immigration flows, which are increasing in many European countries. The imperatives that current immigration trends impose on European democracies bring to light a number of issues that need to be addressed. What are the patterns and dynamics of cultural integration? How do they differ across immigrants of different ethnic groups and religious faiths? How do they differ across host societies? What are the implications and consequences for market outcomes and public policy? Which kind of institutional contexts are more or less likely to accommodate the cultural integration of immigrants? All these questions are crucial for policy makers and await answers. This book aims to provide a stepping stone to the debate. Taking an economic perspective, this edited book presents a current, comparative picture of the process of cultural integration of immigrants across Europe. It documents the main economic debates on the causes and consequences of cultural integration of immigrants, and provides detailed descriptions of the cultural and economic integration process in seven main European countries, including France, Germany, Italy, Spain, Sweden, Switzerland, and the United Kingdom. It also compares the European context with the integration of immigrants in the United States. (Publisher's abstract

Glycoproteomics: a challenge (balance) to mass spectrometry acquisition and interpretation

International audienceGlycopeptide-based tandem-mass-spectrometry enables site-specific glycosylation analysis, allowing us to explore the glycomes and potential functions. While performing glycopeptides MS/MS, fragmentation can be complicated by the heterogeneous glycans and amino-acid combination, which is the first bottleneck. Several fragmentation modes, such as stepped-collision-energy (sce), and a hybrid of both electron transfer and collision-induced dissociation, were reported to have more potential to generate an informative spectrum(1, 2). Furthermore, the superimposition of fragments from peptides and glycans on a single spectrum is a major limitation for annotation and identification accuracy(3, 4). Hence, obtaining unambiguous interrogation depends on the quality of both acquisition and interpretation.We have performed MS/MS of tryptic peptides separated prior by reversed-phase chromatography on a Tribrid system(ThermoFisher Eclipse) with HCD followed by the aforementioned two fragmentation modes triggered by product-dependent (pd) ion of glycan. MS/MS spectra were searched against the UniProt database using Proteome Discoverer (PD) with the Byonic searching node, and the results were manually verified. Further validation was conducted by releasing glycans with a homemade glycosidase and mapping with a MALDI-TOF/TOF(Sciex 5800) system. Our analysis of N-glycosylated samples demonstrated that pd-EthcD didn’t improve the identifications compared to other methods.Moreover, several aspects require improvements during annotation and interrogation, regardless of the fragmentation types. Firstly, glycopeptide MS1-peaking can fail when performing a match-between-run chromatogram and spectrum alignment. Secondly, MS/MS peaks-fragments annotation may be misleading when one isotopic-cluster is simultaneously assigned to two fragments. Thirdly, filtering results by scores as a common proteomics workflow might not lead to confident identifications. For example, scores> 300 and DeltaMod scores> 10 are Byonic-defined thresholds for confident peptide-sequence-match and modification localization. However, manual reviewing of the identifications showed insufficient justifications.Eventually, we proposed a workflow combining glycan MALDI-MS-MS/MS analyses to improve the robustness of glycopeptide nanoLC-MS/MS spectrum annotation and identification. The complementary profiling was applied to the porcine Luteinizing hormone study

Successful use of ovident epithelial cell coculture for in vitro production of viable red deer (Cervus elaphus) embryos

International audienceTechniques for in vitro production (IVP) of viable embryos have been thoroughly developed in several domestic species in view to improve breeding efficiency. When applied to wild life, these techniques may also help the maintenance of biodiversity through amplification of sparse animals offspring and facilitation of genetic material exchange. During the successive steps of IVP, i.e. oocyte in vitro maturation (IVM), fertilization (IVF) and early embryo development (IVD) to the blastocyst stage, gametes and embryos are faced with unusual environment, including oxidative stress, known to be detrimental to their survival. In the present study, starting from methods developed in domestic species, we have adapted IVP to produce viable red deer embryos. In a first experiment, cumulus cells were removed from in vitro matured oocytes either before or after IVF. The presence of cumulus cells during IVF did not affect final cleavage or development rates. In a second experiment, in vitro matured oocytes were fertilized in the presence of cumulus cells and cultured in SOFaaBSA medium alone or in the presence of ovine oviduct epithelial cell (oOEC) monolayer. Whereas, oviduct cells did not improve the cleavage rate, they significantly increased the rate of embryos reaching the blastocyst stage (from 3 to 25% of total oocytes). Ten blastocysts from oOEC coculture were transferred after freezing and thawing to five recipient hinds and gave rise to three pregnancies. The three pregnant hinds gave birth to three live and normal calves