51 research outputs found
Effects of low-dose gestational tcdd exposure on behavior and on hippocampal neuron morphology and gene expression in mice
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a persistent and toxic environmental pollutant. Gestational exposure to TCDD has been linked to cognitive and motor deficits, and increased incidence of autism spectrum disorder (ASD) traits in children. Most animal studies of these neurodevelopmental effects involve acute TCDD exposure, which does not model typical exposure in humans.publishedVersio
CD4 T Cell Cytokine Differentiation: The B Cell Activation Molecule, OX40 Ligand, Instructs CD4 T Cells to Express Interleukin 4 and Upregulates Expression of the Chemokine Receptor, Blr-1
This report investigates the role of OX40 ligand (OX40L) and its receptor, OX40, expressed on activated B and T cells, respectively, in promoting the differentiation of T helper type 2 (Th2) CD4 T cells. These molecules are expressed in vivo by day 2 after priming with T cellâ dependent antigens. Their expression coincides with the appearance of immunoglobulin (Ig)G switch transcripts and mRNA for interleukin (IL)-4 and interferon (IFN)-Îł, suggesting that this molecular interaction plays a role in early cognate interactions between B and T cells. In vitro, we report that costimulation of naive, CD62Lhigh CD4 T cells through OX40 promotes IL-4 expression and upregulates mRNA for the chemokine receptor, blr-1, whose ligand is expressed in B follicles and attracts lymphocytes to this location. Furthermore, T cell stimulation through OX40 inhibits IFN-Îł expression in both CD8 T cells and IL-12âstimulated CD4 T cells. Although this signal initiates IL-4 expression, IL-4 itself is strongly synergistic. Our data suggest that OX40L on antigen-activated B cells instructs naive T cells to differentiate into Th2 cells and migrate into B follicles, where T cellâdependent germinal centers develop
Follicular helper T cells are required for systemic autoimmunity
Production of high-affinity pathogenic autoantibodies appears to be central to the pathogenesis of lupus. Because normal high-affinity antibodies arise from germinal centers (GCs), aberrant selection of GC B cells, caused by either failure of negative selection or enhanced positive selection by follicular helper T (TFH) cells, is a plausible explanation for these autoantibodies. Mice homozygous for the san allele of Roquin, which encodes a RING-type ubiquitin ligase, develop GCs in the absence of foreign antigen, excessive TFH cell numbers, and features of lupus. We postulated a positive selection defect in GCs to account for autoantibodies. We first demonstrate that autoimmunity in Roquinsan/san (sanroque) mice is GC dependent: deletion of one allele of Bcl6 specifically reduces the number of GC cells, ameliorating pathology. We show that Roquinsan acts autonomously to cause accumulation of TFH cells. Introduction of a null allele of the signaling lymphocyte activation molecule family adaptor Sap into the sanroque background resulted in a substantial and selective reduction in sanroque TFH cells, and abrogated formation of GCs, autoantibody formation, and renal pathology. In contrast, adoptive transfer of sanroque TFH cells led to spontaneous GC formation. These findings identify TFH dysfunction within GCs and aberrant positive selection as a pathway to systemic autoimmunity
Physics with the KLOE-2 experiment at the upgraded DANE
Investigation at a --factory can shed light on several debated issues
in particle physics. We discuss: i) recent theoretical development and
experimental progress in kaon physics relevant for the Standard Model tests in
the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum
Mechanics from time evolution of entangled kaon states, iii) the interest for
improving on the present measurements of non-leptonic and radiative decays of
kaons and eta/eta mesons, iv) the contribution to understand the
nature of light scalar mesons, and v) the opportunity to search for narrow
di-lepton resonances suggested by recent models proposing a hidden dark-matter
sector. We also report on the physics in the continuum with the
measurements of (multi)hadronic cross sections and the study of gamma gamma
processes.Comment: 60 pages, 41 figures; added affiliation for one of the authors; added
reference to section
Functional and phenotypic heterogeneity of Th17 cells in health and disease
Background
Th17 cells have nonredundant roles in maintaining immunity, particularly at mucosal surfaces. These roles are achieved principally through the production of cytokines and the recruitment of other immune cells to maintain the integrity of mucosal barriers and prevent the dissemination of microorganisms. Th17 cells are heterogeneous and exhibit a considerable degree of plasticity. This allows these cells to respond to changing environmental challenges. However, Th17 cells also play proâinflammatory roles in chronic autoimmune diseases. The trigger(s) that initiate these Th17 responses in chronic autoimmune diseases remain unclear.
Design
In this report, we provide an overview of studies involving animal models, patient data, genome wide association studies and clinical trials targeting ILâ17 for treatment of patients to gain a better understanding of the pathogenic roles of Th17 cells play in a range of autoimmune diseases.
Results
The report sheds light on likely triggers that initiate or perpetuate Th17 responses that promote chronic inflammation and autoimmunity. The divergent effects of tumour necrosis factor alpha blockade on Th17 cells in patients, is explored. Furthermore, we highlight the role of Th17 cells in inducing autoreactive B cells, leading to autoantibody production. Pathogenic bacterial species can change Th17 cell phenotype and responses. These findings provide insights into how Th17 cells could be induced to promoting autoimmune disease pathogenesis.
Conclusion
This article provides an overview of the distinct roles Th17 cells play in maintaining immunity at mucosal surfaces and in skin mucosa and how their functional flexibility could be linked with chronic inflammation in autoimmune rheumatic diseases
Philosophie des sciences et du langage <br>: Entretien avec Pierre Jacob (CNRS), réalisé par Peter Stockinger (INALCO, Paris).
Analyse du premier entretien avec le philosophe et chercheur en sciences cognitives Pierre JACOB.Pierre JACOB est directeur de recherche au CNRS et président de la Société Européenne de philosophie et psychologie.Ses recherches portent sur la philosophie générale des sciences, la philosophie du langage et la philosophie de l'esprit et des sciences cognitives
Philosophie des sciences et du langage: Entretien avec Pierre Jacob (CNRS), réalisé par Peter Stockinger (INALCO, Paris).
Analyse du premier entretien avec le philosophe et chercheur en sciences cognitives Pierre JACOB.Pierre JACOB est directeur de recherche au CNRS et président de la Société Européenne de philosophie et psychologie.Ses recherches portent sur la philosophie générale des sciences, la philosophie du langage et la philosophie de l'esprit et des sciences cognitives
L'empirisme logique. : Entretien avec Pierre Jacob (CNRS), réalisé par Peter Stockinger (INALCO).
Corpus "Conversations Savantes"Second entretien avec Pierre JACOB, directeur de recherche au CNRS et président de la Société Européenne de philosophie et psychologie.Ses recherches portent sur la philosophie générale des sciences, la philosophie du langage et la philosophie de l'esprit et des sciences cognitives
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