90 research outputs found

    CD155 on HIV-infected cells is not modulated by HIV-1 Vpu and Nef but synergizes with NKG2D ligands to trigger NK cell lysis of autologous primary HIV-infected cells

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    Activation of primary CD4(+) T cells induces the CD155, but not the CD112 ligands for the natural killer (NK) cell activation receptor (aNKR) CD226 [DNAX accessory molecule-1 (DNAM-1)]. We hypothesize that HIV productively infects activated CD4(+) T cells and makes itself vulnerable to NK cell-mediated lysis when CD155 on infected T cells engages DNAM-1. The primary objective of this study is to determine whether CD155 alone or together with NKG2D ligands triggers autologous NK cell lysis of HIV-infected T cells and whether HIV modulates CD155. To determine whether HIV modulates this activation ligand, we infected “activated” CD4(+) T cells with HIV in the absence or presence of Nef and/or Vpu and determined by flow cytometry whether they modulated CD155. To determine if CD155 alone, or together with NKG2D ligands, triggered NK cell lysis of autologous HIV-infected T cells, we treated purified NK cells with DNAM-1 and/or NKG2D blocking antibodies before the addition of purified autologous HIV-infected cells in cytolytic assays. Finally, we determined whether DNAM-1 works together with NKG2D as an NK cell coactivation receptor (caNKR) or whether they work independently as aNKRs to induce an NK cell lytic response. We demonstrate that HIV and specifically Nef and/or Vpu do not modulate CD155 on infected primary T cells; and both CD155 and NKG2D ligands synergize as aNKRs to trigger NK cell lysis of the infected cell

    Development of Encounter Protocols and Assessment of Significant Adverse Impact by Bottom Trawling for Sponge Grounds and Sea Pen Fields in the NAFO Regulatory Area

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    We provide a scientific basis for recommending commercial encounter protocols for sponges and sea pens in the NRA. For each we provide an assessment of significant adverse impact of bottom trawling taking into account published and new data on gear efficiency and selectivity, incidental mortality and recoverability. The proportion of VMS trawls in 2010 that would be impacted by lowering the current thresholds is estimated following previously established methods. Approaches to move-on rules are also considered

    Layers Utilized by an ArcGIS Model to Approximate Commercial Coral and Sponge By-catch in the NAFO Regulatory Area

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    This report specifically addresses Fisheries Commission Request #16: "Implement and/or further refine the existing GIS simulation/modelling framework, in conjunction with the VMS data supplied by the NAFO Secretariat ...", brought forth in the Fisheries Commission 33rd Annual Meeting Report (NAFO, 2011a). Data layers utilized by the model as well as their various means of construction are described in detail including the generation of NAFO VMS trawl lines. These VMS trawl line data were used to better understand fishing behaviour and also generate a new standard trawl length (13.8 nm) to be utilized by trawl simulations. The justification for utilizing just the Spain/EU research trawl by-catch dataset instead of the combined Canada/Spain/EU dataset for the production of higher resolution sponge and sea pen biomass surfaces is also made. It is demonstrated how this high resolution (5x5 km cell grid) Spain/EU data biomass layer could be utilized with 2000 randomly placed and oriented 13.8 nm simulation trawls to generate by-catch values, organized by thresholds, to capture the distributional extent of high concentration sponge and sea pen areas. This serves as the basis for a kernel density polygon analysis that calculates a commercial sponge and sea pen encounter threshold (Kenchington et al., 2011). Finally, using the Spain/EU only high resolution biomass surface, by-catch output from VMS trawls and their simulated 13.8 nm standard trawl line counterparts are compared

    Report of the Scientific Council Meeting 01 -15 June 2017

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    Council met at the Sobey Building, Saint Mary’s University, Halifax, NS, Canada, during 01 – 15 June 2017, to consider the various matters in its Agenda. Representatives attended from Canada, Denmark (in respect of Faroe Islands and Greenland), the European Union (France, Germany (via WebEx), Portugal, Spain, the United Kingdom and the European Commission), Japan, the Russian Federation and the United States of America. Observers from the Ecology Action Centre and Dalhousie University were also present. The Executive Secretary, Scientific Council Coordinator and other members of the Secretariat were in attendance. The Executive Committee met prior to the opening session of the Council to discuss the provisional agenda and plan of work. The Council was called to order at 1000 hours on 01 June 2017. The provisional agenda was adopted with modification. The Scientific Council Coordinator was appointed the rapporteur. The Council was informed that the meeting was quorate and authorization had been received by the Executive Secretary for proxy votes from the European Union, Denmark (in respect of Faroe Islands and Greenland), Iceland, Japan, Republic of Korea, and Norway. The opening session was adjourned at 1200 hours on 01 June 2017. Several sessions were held throughout the course of the meeting to deal with specific items on the agenda. The Council considered adopted the STACFEN report on 8 June 2017, and the STACPUB, STACFIS and STACREC reports on 15 June 2017. The concluding session was called to order at 0830 hours on 15 June 2017. The Council considered and adopted the report the Scientific Council Report of this meeting of 01 -15 June 2017. The Chair received approval to leave the report in draft form for about two weeks to allow for minor editing and proof-reading on the usual strict understanding there would be no substantive changes. The meeting was adjourned at 1430 hours on 15 June 2017. The Reports of the Standing Committees as adopted by the Council are appended as follows: Appendix I - Report of the Standing Committee on Fisheries Environment (STACFEN), Appendix II - Report of Standing Committee on Publications (STACPUB), Appendix III - Report of Standing Committee on Research Coordination (STACREC), and Appendix IV - Report of Standing Committee on Fisheries Science (STACFIS). The Agenda, List of Research (SCR) and Summary (SCS) Documents, and List of Representatives, Advisers and Experts, are given in Appendix V-VII. The Council’s considerations on the Standing Committee Reports, and other matters addressed by the Council follow in Sections II-XV

    The driver landscape of sporadic chordoma.

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    Chordoma is a malignant, often incurable bone tumour showing notochordal differentiation. Here, we defined the somatic driver landscape of 104 cases of sporadic chordoma. We reveal somatic duplications of the notochordal transcription factor brachyury (T) in up to 27% of cases. These variants recapitulate the rearrangement architecture of the pathogenic germline duplications of T that underlie familial chordoma. In addition, we find potentially clinically actionable PI3K signalling mutations in 16% of cases. Intriguingly, one of the most frequently altered genes, mutated exclusively by inactivating mutation, was LYST (10%), which may represent a novel cancer gene in chordoma.Chordoma is a rare often incurable malignant bone tumour. Here, the authors investigate driver mutations of sporadic chordoma in 104 cases, revealing duplications in notochordal transcription factor brachyury (T), PI3K signalling mutations, and mutations in LYST, a potential novel cancer gene in chordoma

    Coral Identification Guide NAFO Area

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    Accurate reporting of benthic corals is increasingly important for mapping distributions and for the continued development of sustainable fisheries under the ecosystem approach. This coral identification guide is intended to help those on-board commercial and research fishing vessels to identify and record the various species of coral likely to be commonly encountered in fishing trawls. The guide is clear and simple to use, and will provide names to the majority of these beautiful bottomdwelling animals. The photographs are typically of caught specimens taken on the deck, as this gives the best picture of what is actually seen. Sadly, we rarely personally see corals in their natural habitat, except by looking at films and photos taken by deep underwater cameras

    Paternal mtDNA and Maleness Are Co-Inherited but Not Causally Linked in Mytilid Mussels

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    BACKGROUND: In marine mussels of the genus Mytilus there are two mitochondrial genomes. One is transmitted through the female parent, which is the normal transmission route in animals, and the other is transmitted through the male parent which is an unusual phenomenon. In males the germ cell line is dominated by the paternal mitochondrial genome and the somatic cell line by the maternal. Research to date has not allowed a clear answer to the question of whether inheritance of the paternal genome is causally related to maleness. METHODOLOGY/PRINCIPAL FINDINGS: Here we present results from hybrid crosses, from triploid mussels and from observations of sperm mitochondria in fertilized eggs which clearly show that maleness and presence of the paternal mitochondrial genome can be decoupled. These same results show that the female mussel has exclusive control of whether her progeny will inherit the mitochondrial genome of the male parent. CONCLUSIONS/SIGNIFICANCE: These findings are important in our efforts to understand the mechanistic basis of this unusual mode of mitochondrial DNA inheritance that is common among bivalves

    Commensal and Pathogenic Bacteria Indirectly Induce IL-22 but Not IFNÎł Production From Human Colonic ILC3s via Multiple Mechanisms

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    Innate lymphoid cells (ILCs) are a diverse family of cells that play critical roles in mucosal immunity. One subset of the ILC family, Group 3 ILCs (ILC3s), has been shown to aid in gut homeostasis through the production of IL-22. IL-22 promotes gut homeostasis through its functional effect on the epithelial barrier. When gut epithelial barrier integrity is compromised, such as in Human Immunodeficiency Virus (HIV) infection and inflammatory bowel disease (IBD), microbes from the gut lumen translocate into the lamina propria, inducing a multitude of potentially pathogenic immune responses. In murine models of bacterial infection, there is evidence that bacteria can induce pro-inflammatory IFNγ production in ILC3s. However, the impact of diverse translocating bacteria, particularly commensal bacteria, in dictating IFNγ versus IL-22 production by human gut ILC3s remains unclear. Here, we utilized an in vitro human lamina propria mononuclear cell (LPMC) model to evaluate ILC3 cytokine production in response to a panel of enteric Gram-positive and Gram-negative commensal and pathogenic bacteria and determined potential mechanisms by which these cytokine responses were induced. The percentages of IL-22-producing ILC3s, but not IFNγ-producing ILC3s, were significantly increased after LPMC exposure to both Gram-positive and Gram-negative commensal or pathogenic bacterial stimuli. Stimulation of IL-22 production from ILC3s was not through direct recognition of bacterial antigen by ILC3s, but rather required the help of accessory cells within the LPMC population. CD11c+ myeloid dendritic cells generated IL-23 and IL-1β in response to enteric bacteria and contributed to ILC3 production of IL-22. Furthermore, ligation of the natural cytotoxicity receptor NKp44 on ILC3s in response to bacteria stimulation also significantly increased the percentage of IL-22-producing ILC3s. Overall, these data demonstrate that human gut microbiota, including commensal bacteria, indirectly modulate colonic ILC3 function to induce IL-22, but additional signals are likely required to induce IFNγ production by colonic ILC3s in the setting of inflammation and microbial translocation
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