333 research outputs found
Glycosaminoglycan profile in macrophages exposed to Candida albicans and interleukins
Glycosaminoglycans (GAG), are extracellular matrix macromolecules that affect the phagocytic properties of macrophages. In order to assess whether the interaction between macrophages and Candida albicans (iCa) provokes changes in the phenotype, we analyzed the GAG profiles in two macrophage lines, ANA-1 (from murine bone-marrow) and BV-2 (from murine brain). We also investigated GAG modulation by interleukin-1alpha (IL-1alpha) and interleukin-6 (IL-6). During iCa treatment and even after the addition of ILs, ANA-1 accumulated less total GAG compared to controls. IL-1 treatment, combined with iCa exposure, induced a decrease in heparan sulfate and chondroitin sulfate chains, and an increase in the hyaluronic acid percentage. IL-6 treatment, with or without iCa, decreased the hyaluronic acid/sulfated GAG ratio. The GAG pattern in BV-2 appears to be different to ANA-1 and iCa exposure does not induce any difference in total GAG. The inhibitory effect induced by ILs on GAG synthesis is less than that observed in ANA-1 and the GAG elution profile is modulated to a lesser extent by treatment with ILs and/or iCa compared to the ANA-1. We suggest that the observed changes in the expression of the individual GAG classes may be responsible for the macrophage functional heterogeneity
Polymorphisms in toll-like receptor genes and susceptibility to pulmonary aspergillosis
Toll-like receptors (TLRs) are important components of innate immunity. We investigated the association between polymorphisms in the TLR2, TLR4, and TLR9 genes and susceptibility to noninvasive forms of pulmonary aspergillosis. A significant association was observed between allele G on Asp299Gly (TLR4) and chronic cavitary pulmonary aspergillosis (odds ratio [OR], 3.46; P =.003). Susceptibility to allergic bronchopulmonary aspergillosis was associated with allele C on T-1237C (TLR9) (OR, 2.49; P =. 043). No particular polymorphism was associated with severe asthma with fungal sensitization. These findings reinforce the importance of innate immunity in the pathogenesis of different forms of aspergillosis.Fundação para a Ciência e Tecnologia, Portugal (POCI/SAU-ESP/61080/
2004 and fellowship to A.C., contract SFRH/BD/11837/2003); CAPES (Brazilian government)
(grant to A.P); and the Fungal Research Trust, United Kingdom
Geraniol Treatment for Irritable Bowel Syndrome: A Double-Blind Randomized Clinical Trial
Geraniol is an acyclic monoterpene alcohol with well-known anti-inflammatory and antimicrobial properties which has shown eubiotic activity towards gut microbiota (GM) in patients with irritable bowel syndrome (IBS). Methods: Fifty-six IBS patients diagnosed according to Rome III criteria were enrolled in an interventional, prospective, multicentric, randomized, double-blinded, placebo-controlled trial. In the treatment arm, patients received a low-absorbable geraniol food supplement (LAGS) once daily for four weeks. Results: Patients treated with LAGS showed a significant reduction in their IBS symptoms severity score (IBS-SSS) compared to the placebo (195 vs. 265, p = 0.001). The rate of responders according to IBS-SSS (reduction ≥ 50 points) was significantly higher in the geraniol vs placebo group (52.0% vs. 16.7%, p = 0.009) mainly due to the IBS mixed subtype. There were notable differences in the microbiota composition after geraniol administration, particularly a significant decrease in a genus of Ruminococcaceae, Oscillospira (p = 0.01), a decreasing trend for the Erysipelotrichaceae and Clostridiaceae families (p = 0.1), and an increasing trend for other Ruminococcaceae taxa, specifically Faecalibacterium (p = 0.09). The main circulating proinflammatory cytokines showed no differences between placebo and geraniol arms. Conclusion: LAGS was effective in treating overall IBS symptoms, together with an improvement in the gut microbiota profile, especially for the IBS mixed subtype
The structure of glutamate transporters shows channel-like features
AbstractNeuronal and glial glutamate transporters remove the excitatory neurotransmitter glutamate from the synaptic cleft and thus prevent neurotoxicity. The proteins belong to a large family of secondary transporters, which includes transporters from a variety of bacterial, archaeal and eukaryotic organisms. The transporters consist of eight membrane-spanning α-helices and two pore-loop structures, which are unique among secondary transporters but may resemble pore-loops found in ion channels. Another distinctive structural feature is the presence of a highly amphipathic membrane-spanning α-helix that provides a hydrophilic path through the membrane. The unusual structural features of the transporters are discussed in relation to their function
Genetic susceptibility to aspergillosis in allogeneic stem-cell transplantation
Invasive aspergillosis (IA) is a major threat to positive outcomes for allogeneic stem-cell transplantation (allo-SCT) patients. Despite presenting similar degrees of immunosuppression, not all individuals at-risk ultimately develop infection. Therefore, the traditional view of neutropenia as a key risk factor for aspergillosis needs to be accommodated within new conceptual advances on host immunity and its relationship to infection. Polymorphisms in innate immune genes, such as those encoding TLRs, cytokines and cytokine receptors, have recently been associated with susceptibility to IA in allo-SCT recipients. This suggests that understanding host-pathogen interactions at the level of host genetic susceptibility will allow the formulation of new targeted and patient-tailored antifungal therapeutics, including improved donor screening.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/65962/2009, SFRH/BPD/46292/2008Specific Targeted Research Projects MANASP (LSHE-CT-2006), contract number 037899 (FP6), Italian Project PRIN2007KLCKP8_004
Olfactory bulb astrocytes link social transmission of stress to cognitive adaptation in male mice
Emotions and behavior can be affected by social chemosignals from conspecifics. For instance, olfactory signals from stressed individuals induce stress-like physiological and synaptic changes in naïve partners. Direct stress also alters cognition, but the impact of socially transmitted stress on memory processes is currently unknown. Here we show that exposure to chemosignals produced by stressed individuals is sufficient to impair memory retrieval in unstressed male mice. This requires astrocyte control of information in the olfactory bulb mediated by mitochondria-associated CB1 receptors (mtCB1). Targeted genetic manipulations, in vivo Ca2+ imaging and behavioral analyses reveal that mtCB1-dependent control of mitochondrial Ca2+ dynamics is necessary to process olfactory information from stressed partners and to define their cognitive consequences. Thus, olfactory bulb astrocytes provide a link between social odors and their behavioral meaning.We would like to thank Delphine Gonzales, Nathalie Aubailly, Ruby Racunica, Jean-Baptiste Bernard and all the personnel of the Animal Facilities of the NeuroCentre Magendie for mouse care. We also thank the genotyping platform of the Neurocentre Magendie for the help in the experiments. The microscopy was done in the Bordeaux Imaging Center a service unit of the CNRS-INSERM and Bordeaux University, member of the national infrastructure France BioImaging supported by the French National Research Agency (ANR-10-INBS-04). We thank all the members of Marsicano’s lab for useful discussions and for their invaluable support. We thank Toni-Lee Sterley and Tamas Fuzesi for providing the software to analyze social behaviors and their valuable input in the analysis. This study was funded by Inserm (to G.M); the European Research Council (Micabra, ERC-2017-AdG-786467, to G.M); Fondation pour la Recherche Medicale (DRM20101220445, to G.M; SPF201809006908 to U.S); the Human Frontiers Science Program (to G.M); Region Aquitaine (CanBrain, AAP2022A-2021-16763610 and −17219710 to G.M); French State/Agence Nationale de la Recherche (ERA-Net Neuron CanShank, ANR-21-NEU2-0001-04, to G.M), (CaMeLS, ANR-23-CE16-0022-01, to G.M), (Hippobese, ANR-23-CE14-0004-03, to G.M); the French government in the framework of the University of Bordeaux IdEx “Investments for the Future” program / GPR BRAIN_2030 (to P.G-S and G.M) and Bordeaux Collaboration Scheme (to P.G-S); La Caixa Research Health grant HR23-00793 (to G.M. and A. B-G); the Canadian Institutes for Health and Research (FDN-148440 to J.S.B); The Basque Government (IT1620-22 to P.G); Atención Primaria, Cronicidad y Promoción de la Salud, Red de Investigación en Atención Primaria de Adicciones (RIAPAd), Instituto de Salud Carlos III (RD21/0009/0006 to P.G
Visual Localization in the Presence of Appearance Changes Using the Partial Order Kernel
Visual localization across seasons and under varying weather and lighting conditions is a challenging task in robotics. In this paper, we present a new sequence-based approach to visual localization using the Partial Order Kernel (POKer), a convolution kernel for string comparison, that is able to handle appearance changes and is robust to speed variations. We use multiple sequence alignment to construct directed acyclic graph representations of the database image sequences, where sequences of images of the same place acquired at different times are represented as alternative paths in a graph. We then use the POKer to compute the pairwise similarities between these graphs and the query image sequences obtained in a subsequent traversal of the environment, and match the corresponding locations. We evaluated our approach on a dataset which features extreme appearance variations due to seasonal changes. The results demonstrate the effectiveness of our approach, where it achieves
higher precision and recall than two state-of-the-art baseline method
Non-hematopoietic cells contribute to protective tolerance to Aspergillus fumigatus via a TRIF pathway converging on IDO
Innate responses combine with adaptive immunity to generate the most effective form of anti-Aspergillus immune resistance. Whereas the pivotal role of dendritic cells in determining the balance between immunopathology and protective immunity to the fungus is well established, we determined that epithelial cells (ECs) also contributes to this balance. Mechanistically, EC-mediated protection occurred through a Toll-like receptor 3/Toll/IL-1 receptor domain-containing adaptor-inducing interferon (TLR3/TRIF)-dependent pathway converging on indoleamine 2,3-dioxygenase (IDO) via non-canonical nuclear factor-?B activation. Consistent with the high susceptibility of TRIF-deficient mice to pulmonary aspergillosis, bone marrow chimeric mice with TRIF unresponsive ECs exhibited higher fungal burdens and inflammatory pathology than control mice, underexpressed the IDO-dependent T helper 1/regulatory T cell (Th1/Treg) pathway and overexpressed the Th17 pathway with massive neutrophilic inflammation in the lungs. Further studies with interferon (IFN)-?, IDO or IL-17R unresponsive cells confirmed the dependency of immune tolerance to the fungus on the IFN-?/IDO/Treg pathway and of immune resistance on the MyD88 pathway controlling the fungal growth. Thus, distinct immune pathways contribute to resistance and tolerance to the fungus, to which the hematopoietic/non-hematopoietic compartments contribute through distinct, yet complementary, roles.We thank Cristina Massi Benedetti for digital art and editing. This work was supported by the Specific Targeted Research Project 'Sybaris' (LSHE-CT-2006), contract number 037899 (FP7) and by the Italian Projects PRIN 2007KLCKP8_004 (to LR) and 2007XYB9T9_001 (to SB). CC and AC were financially supported by fellowships from Fundacao para a Ciencia e Tecnologia, Portugal (contracts SFRH/BD/65962/2009 and SFRH/BPD/46292/2008, respectively)
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