118 research outputs found

    A fiber-modified adenoviral vector interacts with immunoevasion molecules of the B7 family at the surface of murine leukemia cells derived from dormant tumors

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    Tumor cells can escape the immune system by overexpressing molecules of the B7 family, e.g. B7-H1 (PD-L1 or CD86), which suppresses the anti-tumor T-cell responses through binding to the PD-1 receptor, and similarly for B7.1 (CD80), through binding to CTLA-4. Moreover, direct interactions between B7-H1 and B7.1 molecules are also likely to participate in the immunoevasion mechanism. In this study, we used a mouse model of tumor dormancy, DA1-3b leukemia cells. We previously showed that a minor population of DA1-3b cells persists in equilibrium with the immune system for long periods of time, and that the levels of surface expression of B7-H1 and B7.1 molecules correlates with the dormancy time. We found that leukemia cells DA1-3b/d365 cells, which derived from long-term dormant tumors and overexpressed B7-H1 and B7.1 molecules, were highly permissive to Ad5FB4, a human adenovirus serotype 5 (Ad5) vector pseudotyped with chimeric human-bovine fibers. Both B7-H1 and B7.1 were required for Ad5FB4-cell binding and entry, since (i) siRNA silencing of one or the other B7 gene transcript resulted in a net decrease in the cell binding and Ad5FB4-mediated transduction of DA1-3b/d365; and (ii) plasmid-directed expression of B7.1 and B7-H1 proteins conferred to Ad5FB4-refractory human cells a full permissiveness to this vector. Binding data and flow cytometry analysis suggested that B7.1 and B7-H1 molecules played different roles in Ad5FB4-mediated transduction of DA1-3b/d365, with B7.1 involved in cell attachment of Ad5FB4, and B7-H1 in Ad5FB4 internalization. BRET analysis showed that B7.1 and B7-H1 formed heterodimeric complexes at the cell surface, and that Ad5FB4 penton, the viral capsomere carrying the fiber projection, could negatively interfere with the formation of B7.1/B7-H1 heterodimers, or modify their conformation. As interactors of B7-H1/B7.1 molecules, Ad5FB4 particles and/or their penton capsomeres represent potential therapeutic agents targeting cancer cells that had developed immunoevasion mechanisms

    Varieties of Capitalism and the Learning Firm: Contemporary Developments in EU and German Company Law - A Comment on the Strine-Bainbridge Debate About Shared Values of Corporate Management and Labor

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    Research in corporate governance and in labour law has been characterized by a disjuncture in the way that scholars in each field are addressing organizational questions related to the business enterprise. While labour has eventually begun to shift perspectives from aspirations to direct employee involvement in firm management, as has been the case in Germany, to a combination of \u27exit\u27 and \u27voice\u27 strategies involving pension fund management and securities litigation, it remains to be seen whether this new stream will unfold as a viable challenge to an otherwise exclusionary shareholder value paradigm. At the same time, recent suggestions made by Delaware Chancery Court Vice Chancellor Strine, to dare think about potentially shared commitments between management and labor - and UCLA\u27s Stephen Bainbridge\u27s response - underline the viability - and, the contestedness - of attempts at moving the corporate governance debate beyond the confines of corporate law proper. While such a wider view had already famously been encouraged by Dean Clarke in his 1986 treatise on Corporate Law (p. 32), mainstream corporate law does not seem to have endorsed this perspective. This paper takes the questionable divide between management and labor within the framework of a limiting corporate governance concept as starting point to explore the institutional dynamics of the corporation, hereby building on the theory of the innovative enterprise, as developed by management theorists Mary O\u27Sullivan and William Lazonick. Largely due to the sustained distance between corporate and labour law scholars, neither group has effectively addressed their common blind spot: a better understanding of the business enterprise itself. In midst of an unceasing flow of affirmations of the finance paradigm of the corporation on the one hand and \u27voice\u27 strategies by labour on the other, it seems to fall to management theorists to draw lessons from the continuing co-existence of different forms of market organization, in which companies appear to thrive. Exploring the conundrum of \u27risky\u27 business decisions within the firm, management theorists have been arguing for the need to adopt a more sophisticated organizational perspective on companies operating on locally, regionally and transnationally shaped, often highly volatile market segments. Research by comparative political economists has revealed a high degree of connectivity between corporate governance and economic performance without, however, arriving at such favourable results only for shareholder value regimes. Such findings support the view that corporate governance regimes are embedded in differently shaped regulatory frameworks, characterized by distinct institutions, both formal and informal, and enforcement processes. As a result of these findings, arguments to disassociate issues of corporate governance from those of the firm\u27s (social) responsibility [CSR] have been losing ground. Instead, CSR can be taken to be an essential part of understanding a particular business enterprise. It is the merging of a comparative political economy perspective on the corporation with one on the organizational features, structures and processes of the corporation, which can help us better understand the distribution of power and knowledge within the \u27learning firm\u27

    Student politics, teaching politics, black politics: an interview with Ansel Wong

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    Ansel Wong is the quiet man of British black politics, rarely in the limelight and never seeking political office. And yet his ‘career’ here – from Black Power firebrand to managing a multimillion budget as head of the Greater London Council’s Ethnic Minority Unit in the 1980s – spells out some of the most important developments in black educational and cultural projects. In this interview, he discusses his identification with Pan-Africanism, his involvement in student politics, his role in the establishment of youth projects and supplementary schools in the late 1960s and 1970s, and his involvement in black radical politics in London in the same period, all of which took place against the background of revolutionary ferment in the Third World and the world of ideas, and were not without their own internal class and ethnic conflicts

    The BRCA2 c.68-7T > A variant is not pathogenic : A model for clinical calibration of spliceogenicity

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    Although the spliceogenic nature of the BRCA2 c.68-7T > A variant has been demonstrated, its association with cancer risk remains controversial. In this study, we accurately quantified by real-time PCR and digital PCR (dPCR), the BRCA2 isoforms retaining or missing exon 3. In addition, the combined odds ratio for causality of the variant was estimated using genetic and clinical data, and its associated cancer risk was estimated by case-control analysis in 83,636 individuals. Co-occurrence in trans with pathogenic BRCA2 variants was assessed in 5,382 families. Exon 3 exclusion rate was 4.5-fold higher in variant carriers (13%) than controls (3%), indicating an exclusion rate for the c.68-7T > A allele of approximately 20%. The posterior probability of pathogenicity was 7.44x10(-115). There was neither evidence for increased risk of breast cancer (OR 1.03; 95% CI 0.86-1.24) nor for a deleterious effect of the variant when co-occurring with pathogenic variants. Our data provide for the first time robust evidence of the nonpathogenicity of the BRCA2 c.68-7T > A. Genetic and quantitative transcript analyses together inform the threshold for the ratio between functional and altered BRCA2 isoforms compatible with normal cell function. These findings might be exploited to assess the relevance for cancer risk of other BRCA2 spliceogenic variants.Peer reviewe

    The BRCA2 c.68-7T > A variant is not pathogenic: A model for clinical calibration of spliceogenicity.

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    Although the spliceogenic nature of the BRCA2 c.68-7T>A variant has been demonstrated, its association with cancer risk remains ontroversial. In this study, we accurately quantified by real-time PCR and digital PCR the BRCA2 isoforms retaining or missing exon 3. In addition, the combined odds ratio for causality of the variant was estimated using genetic and clinical data, and its associated cancer risk was estimated by case-control analysis in 83,636 individuals. Co-occurrence in trans with pathogenic BRCA2 variants was assessed in 5,382 families. Exon 3 exclusion rate was 4.5-fold higher in variant carriers (13%) than controls (3%), indicating an exclusion rate for the c.68-7T>A allele of approximately 20%. The posterior probability of pathogenicity was 7.44 x 10-115. There was neither evidence for increased risk of breast cancer (OR 1.03; 95% CI 0.86-1.24), nor for a deleterious effect of the variant when co-occurring with pathogenic variants. Our data provide for the first time robust evidence of the non-pathogenicity of the BRCA2 c.68-7T>A. Genetic and quantitative transcript analyses together inform the threshold for the ratio between functional and altered BRCA2 isoforms compatible with normal cell function. These findings might be exploited to assess the relevance for cancer risk of other BRCA2 spliceogenic variants

    The Forest Observation System, building a global reference dataset for remote sensing of forest biomass

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    International audienceForest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (aGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. aGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. all plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities

    Fine-Scale Mapping of the 5q11.2 Breast Cancer Locus Reveals at Least Three Independent Risk Variants Regulating MAP3K1

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