89 research outputs found

    Caspase-Dependent Inhibition of Mousepox Replication by gzmB

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    BACKGROUND: Ectromelia virus is a natural mouse pathogen, causing mousepox. The cytotoxic T (Tc) cell granule serine-protease, granzyme B, is important for its control, but the underlying mechanism is unknown. Using ex vivo virus immune Tc cells, we have previously shown that granzyme B is able to activate several independent pro-apoptotic pathways, including those mediated by Bid/Bak/Bax and caspases-3/-7, in target cells pulsed with Tc cell determinants. METHODS AND FINDINGS: Here we analysed the physiological relevance of those pro-apoptotic pathways in ectromelia infection, by incubating ectromelia-immune ex vivo Tc cells from granzyme A deficient (GzmB(+) Tc cells) or granzyme A and granzyme B deficient (GzmAxB(-/-) Tc cell) mice with ectromelia-infected target cells. We found that gzmB-induced apoptosis was totally blocked in ectromelia infected or peptide pulsed cells lacking caspases-3/-7. However ectromelia inhibited only partially apoptosis in cells deficient for Bid/Bak/Bax and not at all when both pathways were operative suggesting that the virus is able to interfere with apoptosis induced by gzmB in case not all pathways are activated. Importantly, inhibition of viral replication in vitro, as seen with wild type cells, was not affected by the lack of Bid/Bak/Bax but was significantly reduced in caspase-3/-7-deficient cells. Both caspase dependent processes were strictly dependent on gzmB, since Tc cells, lacking both gzms, neither induced apoptosis nor reduced viral titers. SIGNIFICANCE: Out findings present the first evidence on the biological importance of the independent gzmB-inducible pro-apoptotic pathways in a physiological relevant virus infection model

    Curation of viral genomes: challenges, applications and the way forward

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    BACKGROUND: Whole genome sequence data is a step towards generating the 'parts list' of life to understand the underlying principles of Biocomplexity. Genome sequencing initiatives of human and model organisms are targeted efforts towards understanding principles of evolution with an application envisaged to improve human health. These efforts culminated in the development of dedicated resources. Whereas a large number of viral genomes have been sequenced by groups or individuals with an interest to study antigenic variation amongst strains and species. These independent efforts enabled viruses to attain the status of 'best-represented taxa' with the highest number of genomes. However, due to lack of concerted efforts, viral genomic sequences merely remained as entries in the public repositories until recently. RESULTS: VirGen is a curated resource of viral genomes and their analyses. Since its first release, it has grown both in terms of coverage of viral families and development of new modules for annotation and analysis. The current release (2.0) includes data for twenty-five families with broad host range as against eight in the first release. The taxonomic description of viruses in VirGen is in accordance with the ICTV nomenclature. A well-characterised strain is identified as a 'representative entry' for every viral species. This non-redundant dataset is used for subsequent annotation and analyses using sequenced-based Bioinformatics approaches. VirGen archives precomputed data on genome and proteome comparisons. A new data module that provides structures of viral proteins available in PDB has been incorporated recently. One of the unique features of VirGen is predicted conformational and sequential epitopes of known antigenic proteins using in-house developed algorithms, a step towards reverse vaccinology. CONCLUSION: Structured organization of genomic data facilitates use of data mining tools, which provides opportunities for knowledge discovery. One of the approaches to achieve this goal is to carry out functional annotations using comparative genomics. VirGen, a comprehensive viral genome resource that serves as an annotation and analysis pipeline has been developed for the curation of public domain viral genome data . Various steps in the curation and annotation of the genomic data and applications of the value-added derived data are substantiated with case studies

    Zika beyond the Americas: Travelers as sentinels of Zika virus transmission. A GeoSentinel analysis, 2012 to 2016.

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    Background: Zika virus (ZIKV) was first isolated in Africa; decades later, caused large outbreaks in the Pacific, and is considered endemic in Asia. We aim to describe ZIKV disease epidemiology outside the Americas, the importance of travelers as sentinels of disease transmission, and discrepancies in travel advisories from major international health organizations. Methods and findings This descriptive analysis using GeoSentinel Surveillance Network records involves sixty-four travel and tropical medicine clinics in 29 countries. Ill returned travelers with a confirmed or probable diagnosis of ZIKV disease acquired in Africa, Asia and the Pacific seen between 1 January 2012 and 31 December 2016 are included, and the frequencies of demographic, trip, and diagnostic characteristics described. ZIKV was acquired in Asia (18), the Pacific (10) and Africa (1). For five countries (Indonesia, Philippines, Thailand, Vietnam, Cameroon), GeoSentinel patients were sentinel markers of recent Zika activity. Additionally, the first confirmed ZIKV infection acquired in Kiribati was reported to GeoSentinel (2015), and a probable case was reported from Timor Leste (April 2016), representing the only case known to date. Review of Zika situation updates from major international health authorities for country risk classifications shows heterogeneity in ZIKV country travel advisories. Conclusions: Travelers are integral to the global spread of ZIKV, serving as sentinel markers of disease activity. Although GeoSentinel data are collected by specialized clinics and do not capture all imported cases, we show that surveillance of imported infections by returned travelers augments local surveillance system data regarding ZIKV epidemiology and can assist with risk categorization by international authorities. However, travel advisories are variable due to risk uncertainties

    Applying IPR-theory to the analysis of innovation competition in mass media content markets

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    This comprehensive book covers relevant issues on how media companies are currently embracing innovation, the levels at which they are doing so, and how innovation can help media companies to meet their development needs in the future. The primary focus of this study is the relationship between management and innovation in the media industry. The book evaluates the importance and the role of innovation within the media industry and helps identify and evaluate the drivers of innovation. The contributors demonstrate and build upon an understanding of the issues and strategies that bind media firms to new processes and technologies and offer clear guidelines on how media companies can accelerate growth through effective internal and external collaboration. Management and Innovation in the Media Industry highlights those issues that influence strategies, organizational structures, media content management and public interest within media firms. This unique study offers both new theoretical and empirical insights on decision making aspects of innovation relevant for those executives and policy makers operating within the media or related industries. It will be of great interest to academics and students in the fields of communication and journalism as well as innovation management

    Pessimistische Theorie - Optimistische Praxis? Unterschiedliche Sichtweisen auf die Konsequenzen der Ökonomisierung der Medien für deren seismographische Funktion in der Demokratie

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    In der Öffentlichkeit kandidieren permanent Problematisierungen der sozialen Ordnung um Aufmerksamkeit. Welche Akteure mit welchen Themen auf welche Weise Aufmerksamkeit erhalten, ist von sozialstrukturellen und -kulturellen Restriktionen und Chancen sowie von Aufmerksamkeitsstrategien abhängig. Die Summe der Restriktionen und Chancen zu öffentlicher Resonanz bestimmt die seismographische Funktion öffentlicher Kommunikation. Nach wie vor gibt es jedoch weder eine umfassendere theoretische Reflexion noch eine breit abgestützte empirische Forschung zur umgreifenden Frage, wie sich moderne Gesellschaften über öffentliche Kommunikation reflexiv steuern. Dieses Buch ist diesem doppelten Problem gewidmet und bietet Anregungen für die theoretische Debatte wie für die empirische Forschung des Wandels der seismographischen Funktion öffentlicher Kommunikation
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