44 research outputs found

    Decreased CD8+ T cell response to Epstein-Barr virus infected B cells in multiple sclerosis is not due to decreased HLA class I expression on B cells or monocytes

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    Background: Patients with multiple sclerosis (MS) have a decreased frequency of CD8(+) T cells reactive to their own Epstein-Barr virus (EBV) infected B cells. We have proposed that this might predispose to the development of MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system. The decreased CD8(+) T cell response to EBV results from a general CD8(+) T cell deficiency and also a decreased proportion of EBV-specific T cells within the total CD8(+) T cell population. Because decreased HLA class I expression on monocytes and B cells has been reported in MS and could influence the generation and effector function of EBV-specific CD8(+) T cells, the present study was undertaken to measure the expression of HLA molecules on B cells and monocytes in patients with MS

    The design of the instrument control unit and its role within the data processing system of the ESA PLATO Mission

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    PLATO1 is an M-class mission of the European Space Agency's Cosmic Vision program, whose launch is foreseen by 2026. PLAnetary Transits and Oscillations of stars aims to characterize exoplanets and exoplanetary systems by detecting planetary transits and conducting asteroseismology of their parent stars. PLATO is the next generation planetary transit space experiment, as it will fly after CoRoT, Kepler, TESS and CHEOPS; its objective is to characterize exoplanets and their host stars in the solar neighbors. While it is built on the heritage from previous missions, the major breakthrough to be achieved by PLATO will come from its strong focus on bright targets, typically with mvv<=8. The prime science goals characterizing and distinguishing PLATO from the previous missions are: the detection and characterization of exoplanetary systems of all kinds, including both the planets and their host stars, reaching down to small, terrestrial planets in the habitable zone; the identification of suitable targets for future, more detailed characterization, including a spectroscopic search for biomarkers in nearby habitable exoplanets (e.g. ARIEL Mission scientific case, E-ELT observations from Ground); a full characterization of the planet host stars, via asteroseismic analysis: this will provide the Community with the masses, radii and ages of the host stars, from which masses, radii and ages of the detected planets will be determined

    Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

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    Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates

    An interaction map of circulating metabolites, immune gene networks, and their genetic regulation

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    Background: Immunometabolism plays a central role in many cardiometabolic diseases. However, a robust map of immune-related gene networks in circulating human cells, their interactions with metabolites, and their genetic control is still lacking. Here, we integrate blood transcriptomic, metabolomic, and genomic profiles from two population-based cohorts (total N = 2168), including a subset of individuals with matched multi-omic data at 7-year follow-up. Results: We identify topologically replicable gene networks enriched for diverse immune functions including cytotoxicity, viral response, B cell, platelet, neutrophil, and mast cell/basophil activity. These immune gene modules show complex patterns of association with 158 circulating metabolites, including lipoprotein subclasses, lipids, fatty acids, amino acids, small molecules, and CRP. Genome-wide scans for module expression quantitative trait loci (mQTLs) reveal five modules with mQTLs that have both cis and trans effects. The strongest mQTL is in ARHGEF3 (rs1354034) and affects a module enriched for platelet function, independent of platelet counts. Modules of mast cell/basophil and neutrophil function show temporally stable metabolite associations over 7-year follow-up, providing evidence that these modules and their constituent gene products may play central roles in metabolic inflammation. Furthermore, the strongest mQTL in ARHGEF3 also displays clear temporal stability, supporting widespread trans effects at this locus. Conclusions: This study provides a detailed map of natural variation at the blood immunometabolic interface and its genetic basis, and may facilitate subsequent studies to explain inter-individual variation in cardiometabolic disease.Peer reviewe
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