118 research outputs found

    The transcription factor Etv5 controls TH17 cell development and allergic airway inflammation

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    Background The differentiation of TH17 cells, which promote pulmonary inflammation, requires the cooperation of a network of transcription factors. Objectives We sought to define the role of Etv5, an Ets-family transcription factor, in TH17 cell development and function. Methods TH17 development was examined in primary mouse T cells wherein Etv5 expression was altered by retroviral transduction, small interfering RNA targeting a specific gene, and mice with a conditional deletion of Etv5 in T cells. The direct function of Etv5 on the Il17 locus was tested with chromatin immunoprecipitation and reporter assays. The house dust mite–induced allergic inflammation model was used to test the requirement for Etv5-dependent TH17 functions in vivo. Results We identify Etv5 as a signal transducer and activator of transcription 3–induced positive regulator of TH17 development. Etv5 controls TH17 differentiation by directly promoting 0a and Il17f expression. Etv5 recruits histone-modifying enzymes to the Il17a–Il17f locus, resulting in increased active histone marks and decreased repressive histone marks. In a model of allergic airway inflammation, mice with Etv5-deficient T cells have reduced airway inflammation and IL-17A/F production in the lung and bronchoalveolar lavage fluid compared with wild-type mice, without changes in TH2 cytokine production. Conclusions These data define signal transducer and activator of transcription 3–dependent feed-forward control of TH17 cytokine production and a novel role for Etv5 in promoting T cell–dependent airway inflammation

    Environmental considerations in the selection of metallurgical processes for the extraction of molybdenum from low grade molybdenite concentrate

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    Environmental considerations are necessitating the development of new extractive processes for the production ofvarious non-ferrous metals from their sulphide ores. The current industrial practice, which involves roasting of the sulphide ores, releases SO, and particulates to the atmosphere.These pollutants require expensive emission control and off-gas cleaning to environmentally acceptable limits before for their discharge to the atmosphere. Of late, a need has been felt to develop new processes which not only can control the air pollution but also avoid the subsequent offgastreatment measures. The present paper deals with the development of two alternate processes, soda ash roasting and lime enhanced carbothermic reduction, for processing the Rakha molybdenite concentrate. The effect of various experimental parameters on the recovery as well as purity of MoO3 and Mo has been discussed. These processes convert the sulphide content of molybdenite to sulphates, thereby avoiding the release of pollutants to the atmosphere

    The transcriptional repressor Bcl6 controls the stability of regulatory T cells by intrinsic and extrinsic pathways

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    Foxp3(+) regulatory T (Treg) cells are essential to maintain immune homeostasis, yet controversy exists about the stability of this cell population. Bcl6-deficient (Bcl6(-/-) ) mice develop severe and spontaneous T helper type 2 (Th2) inflammation and Bcl6-deficient Treg cells are ineffective at controlling Th2 responses. We used a lineage tracing approach to analyse the fate of Treg cells in these mice. In the periphery of Bcl6(-/-) mice, increased numbers of Foxp3-negative 'exTreg' cells were found, particularly in the CD25(+) population. ExTreg cells from Bcl6(-/-) mice expressed increased interleukin-17 (IL-17) and extremely elevated levels of Th2 cytokines compared with wild-type exTreg cells. Although Treg cells normally express only low levels of cytokines, Treg cells from Bcl6(-/-) mice secreted higher levels of IL-4, IL-5, IL-13 and IL-17 than wild-type conventional T cells. Next, Treg-specific conditional Bcl6-deficient (Bcl6(Foxp3-/-) ) mice were analysed. Bcl6(Foxp3-/-) mice do not develop inflammatory disease, indicating a requirement for non-Treg cells for inflammation in Bcl6(-/-) mice, and have normal numbers of exTreg cells. We induced Th2-type allergic airway inflammation in Bcl6(Foxp3-/-) mice, and found that while exTreg cytokine expression was normal, Bcl6-deficient Treg cells expressed higher levels of the Th2-specific regulator Gata3 than Bcl6(+) Treg cells. Bcl6(Foxp3-/-) mice had increased numbers of Th2 cells after induction of airway inflammation and increased T cells in the bronchoalveolar lavage fluid. These data show both Treg-intrinsic and Treg-extrinsic roles for Bcl6 in controlling Treg cell stability and Th2 inflammation, and support the idea that Bcl6 expression in Treg cells is critical for controlling Th2 responses

    Mast Cells Regulate Epidermal Barrier Function and the Development of Allergic Skin Inflammation

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    Atopic dermatitis is a chronic inflammatory skin disease characterized by infiltration of eosinophils, T helper cells, and mast cells. The role of mast cells in atopic dermatitis is not completely understood. To define the effects of mast cells on skin biology, we observed that mast cells regulate the homeostatic expression of epidermal differentiation complex and other skin genes. Decreased epidermal differentiation complex gene expression in mice that genetically lack mast cells (Kit(W-sh/W-sh) mice) is associated with increased uptake of protein antigens painted on the skin by dendritic cells (DCs) compared with similarly treated wild-type mice, suggesting a protective role for mast cells in exposure to nominal environmental allergens. To test this further, we crossed Kit(W-sh/W-sh) mice with signal transducer and activator of transcription 6 (i.e., Stat6) VT transgenic mice that develop spontaneous atopic dermatitis-like disease that is dependent on T helper cell 2 cytokines and is associated with high serum concentrations of IgE. We observed that Stat6VT × Kit(W-sh/W-sh) mice developed more frequent and more severe allergic skin inflammation than Stat6VT transgenic mice that had mast cells. Together, these studies suggest that mast cells regulate epidermal barrier function and have a potential protective role in the development of atopic dermatitis-like diseas

    IL-4 impairs wound healing potential in the skin by repressing fibronectin expression

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    BACKGROUND: Atopic dermatitis (AD) is characterized by intense pruritis and is a common childhood inflammatory disease. Many factors are known to affect AD development, including the pleiotropic cytokine IL-4. Yet little is known regarding the direct effects of IL-4 on keratinocyte function. OBJECTIVE AND METHODS: In this report RNA sequencing and functional assays were used to define the effect of the allergic environment on primary keratinocyte function and wound repair in mice. RESULTS: Acute or chronic stimulation by IL-4 modified expression of more than 1000 genes expressed in human keratinocytes that are involved in a broad spectrum of nonoverlapping functions. Among the IL-4-induced changes, repression of fibronectin critically impaired the human keratinocyte wound response. Moreover, in mouse models of spontaneous and induced AD-like lesions, there was delayed re-epithelialization. Importantly, topical treatment with fibronectin restored the epidermal repair response. CONCLUSION: Keratinocyte gene expression is critically shaped by IL-4, altering cell fate decisions, which are likely important for the clinical manifestations and pathology of allergic skin disease

    Flying with ionic wind

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    Aeroplanes use propellers and turbines, and are typically powered by fossil-fuel combustion. An alternative method of propelling planes has been demonstrated that does not require moving parts or combustion

    Update On The Zebrafish Genome Project

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    The zebrafish genome, which consists of 25 linkage groups and is ~1.4Gb in size, is being sequenced, finished and analysed in its entirety at the Wellcome Trust Sanger Institute. The manual annotation is provided by the Human and Vertebrate Analysis and Annotation (HAVANA) group and is released at regular intervals onto the Vertebrate Genome Annotation (Vega) database ("http://vega.sanger.ac.uk":http://vega.sanger.ac.uk) and may be viewed as a DAS source in Ensembl ("http://www.ensembl.org/Danio_rerio":http://www.ensembl.org/Danio_rerio). 

Our annotation is compiled in close collaboration with the Zebrafish Information Network (ZFIN) ("http://zfin.org/":http://zfin.org/), which has enabled us to provide an accurate, dynamic and distinct resource for the zebrafish community as a whole.

Annotation is based on the reference genome sequence, which is derived from a minimal tile path assembly composed of clones that have been mapped, sequenced and meticulously finished to a sequence accuracy of over 99.9% per 100Kb. We expect to have 90% of the zebrafish genome to a finished standard by the end of 2009. Our approach to annotation uses two strategies. Firstly, the generation and annotation of gene lists comprising of cDNA (8995 in total) found in ZFIN that maps to our current reference assembly. And, secondly, by using clone by clone annotation, where we have annotated over 3200 genes, 1100 transcripts and 130 pseudogenes across 11 linkage groups and 3530 clones. As well as our on-going genome annotation we also welcome external annotation requests for specific genes and regions, which already include the annotation of 93 genes associated with human obesity and the scheduled annotation of the Major Histocompatability Complex, which will utilise reference sequence taken from libraries of a double haploid fish and complement our previous work on the human and mouse MHC already published.
 
External requests and any feedback, questions or requests can be sent to zfish-help [at] sanger.ac.uk

    Antigen-Specific IgG ameliorates allergic airway inflammation via Fcγ receptor IIB on dendritic cells

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    <p>Abstract</p> <p>Background</p> <p>There have been few reports on the role of Fc receptors (FcRs) and immunoglobulin G (IgG) in asthma. The purpose of this study is to clarify the role of inhibitory FcRs and antigen presenting cells (APCs) in pathogenesis of asthma and to evaluate antigen-transporting and presenting capacity by APCs in the tracheobronchial mucosa.</p> <p>Methods</p> <p>In FcγRIIB deficient (KO) and C57BL/6 (WT) mice, the effects of intratracheal instillation of antigen-specific IgG were analysed using the model with sensitization and airborne challenge with ovalbumin (OVA). Thoracic lymph nodes instilled with fluorescein-conjugated OVA were analysed by fluorescence microscopy. Moreover, we analysed the CD11c<sup>+ </sup>MHC class II<sup>+ </sup>cells which intaken fluorescein-conjugated OVA in thoracic lymph nodes by flow cytometry. Also, lung-derived CD11c<sup>+ </sup>APCs were analysed by flow cytometry. Effects of anti-OVA IgG1 on bone marrow dendritic cells (BMDCs) <it>in vitro </it>were also analysed. Moreover, in FcγRIIB KO mice intravenously transplanted dendritic cells (DCs) differentiated from BMDCs of WT mice, the effects of intratracheal instillation of anti-OVA IgG were evaluated by bronchoalveolar lavage (BAL).</p> <p>Results</p> <p>In WT mice, total cells and eosinophils in BAL fluid reduced after instillation with anti-OVA IgG1. Anti-OVA IgG1 suppressed airway inflammation in hyperresponsiveness and histology. In addition, the number of the fluorescein-conjugated OVA in CD11c<sup>+ </sup>MHC class II<sup>+ </sup>cells of thoracic lymph nodes with anti-OVA IgG1 instillation decreased compared with PBS. Also, MHC class II expression on lung-derived CD11c<sup>+ </sup>APCs with anti-OVA IgG1 instillation reduced. Moreover, in vitro, we showed that BMDCs with anti-OVA IgG1 significantly decreased the T cell proliferation. Finally, we demonstrated that the lacking effects of anti-OVA IgG1 on airway inflammation on FcγRIIB KO mice were restored with WT-derived BMDCs transplanted intravenously.</p> <p>Conclusion</p> <p>Antigen-specific IgG ameliorates allergic airway inflammation via FcγRIIB on DCs.</p

    The UniProt-GO Annotation database in 2011

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    The GO annotation dataset provided by the UniProt Consortium (GOA: http://www.ebi.ac.uk/GOA) is a comprehensive set of evidenced-based associations between terms from the Gene Ontology resource and UniProtKB proteins. Currently supplying over 100 million annotations to 11 million proteins in more than 360 000 taxa, this resource has increased 2-fold over the last 2 years and has benefited from a wealth of checks to improve annotation correctness and consistency as well as now supplying a greater information content enabled by GO Consortium annotation format developments. Detailed, manual GO annotations obtained from the curation of peer-reviewed papers are directly contributed by all UniProt curators and supplemented with manual and electronic annotations from 36 model organism and domain-focused scientific resources. The inclusion of high-quality, automatic annotation predictions ensures the UniProt GO annotation dataset supplies functional information to a wide range of proteins, including those from poorly characterized, non-model organism species. UniProt GO annotations are freely available in a range of formats accessible by both file downloads and web-based views. In addition, the introduction of a new, normalized file format in 2010 has made for easier handling of the complete UniProt-GOA data set
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