113 research outputs found

    Lepton-Flavored Dark Matter

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    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV - 1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. mu->3e, tau->e mu mu, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10 - 100 TeV), whereas the 3.6sigma deviation of the muon g-2 from the standard model can be explained by a new-physics scale < O(1 TeV). Here, we suggest that it may not be a coincidence that both the muon g-2 and the relic density can be satisfied by a new-physics scale < 1 TeV. We consider the possibility of a gauged lepton-flavor interaction that couples at tree level only to mu- and tau-flavored leptons and the dark sector. Dark matter thus interacts appreciably only with particles of mu and tau flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV - 1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g-2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e+e- colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables.Comment: includes additional discussions, results unchange

    Veterans and Agent Orange: Update 11 (2018) (2018)

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    Contents ACRONYMS AND ABBREVIATIONS xvii SUMMARY 1 1 INTRODUCTION 17 Previous Veterans and Agent Orange Reports, 18 Charge to the Committee, 19 Information Gathering, 20 Organization of the Report, 21 2 BACKGROUND 25 The Current Population of Vietnam Veterans,25 Military Use of Herbicides in Vietnam, 27 Exposure of Different Groups of Vietnam Veterans, 30 Characterizing Exposure, 38 Determining Increased Risk in Vietnam Veterans, 4

    Interleukin-11 Is the Dominant IL-6 Family Cytokine during Gastrointestinal Tumorigenesis and Can Be Targeted Therapeutically

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    SummaryAmong the cytokines linked to inflammation-associated cancer, interleukin (IL)-6 drives many of the cancer “hallmarks” through downstream activation of the gp130/STAT3 signaling pathway. However, we show that the related cytokine IL-11 has a stronger correlation with elevated STAT3 activation in human gastrointestinal cancers. Using genetic mouse models, we reveal that IL-11 has a more prominent role compared to IL-6 during the progression of sporadic and inflammation-associated colon and gastric cancers. Accordingly, in these models and in human tumor cell line xenograft models, pharmacologic inhibition of IL-11 signaling alleviated STAT3 activation, suppressed tumor cell proliferation, and reduced the invasive capacity and growth of tumors. Our results identify IL-11 signaling as a potential therapeutic target for the treatment of gastrointestinal cancers

    Differential IRF8 Transcription Factor Requirement Defines Two Pathways of Dendritic Cell Development in Humans

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    The formation of mammalian dendritic cells (DCs) is controlled by multiple hematopoietic transcription factors, including IRF8. Loss of IRF8 exerts a differential effect on DC subsets, including plasmacytoid DCs (pDCs) and the classical DC lineages cDC1 and cDC2. In humans, cDC2-related subsets have been described including AXL+ SIGLEC6+ pre-DC, DC2 and DC3. The origin of this heterogeneity is unknown. Using highdimensional analysis, in vitro differentiation, and an allelic series of human IRF8 deficiency, we demonstrated that cDC2 (CD1c+ DC) heterogeneity originates from two distinct pathways of development. The lymphoidprimed IRF8hi pathway, marked by CD123 and BTLA, carried pDC, cDC1, and DC2 trajectories, while the common myeloid IRF8lo pathway, expressing SIRPA, formed DC3s and monocytes. We traced distinct trajectories through the granulocyte-macrophage progenitor (GMP) compartment showing that AXL+ SIGLEC6+ pre-DCs mapped exclusively to the DC2 pathway. In keeping with their lower requirement for IRF8, DC3s expand to replace DC2s in human partial IRF8 deficiency

    Aberrant actin depolymerization triggers the pyrin inflammasome and autoinflammatory disease that is dependent on IL-18, not IL-1beta

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    Gain-of-function mutations that activate the innate immune system can cause systemic autoinflammatory diseases associated with increased IL-1β production. This cytokine is activated identically to IL-18 by an intracellular protein complex known as the inflammasome; however, IL-18 has not yet been specifically implicated in the pathogenesis of hereditary autoinflammatory disorders. We have now identified an autoinflammatory disease in mice driven by IL-18, but not IL-1β, resulting from an inactivating mutation of the actin-depolymerizing cofactor Wdr1. This perturbation of actin polymerization leads to systemic autoinflammation that is reduced when IL-18 is deleted but not when IL-1 signaling is removed. Remarkably, inflammasome activation in mature macrophages is unaltered, but IL-18 production from monocytes is greatly exaggerated, and depletion of monocytes in vivo prevents the disease. Small-molecule inhibition of actin polymerization can remove potential danger signals from the system and prevents monocyte IL-18 production. Finally, we show that the inflammasome sensor of actin dynamics in this system requires caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain, and the innate immune receptor pyrin. Previously, perturbation of actin polymerization by pathogens was shown to activate the pyrin inflammasome, so our data now extend this guard hypothesis to host-regulated actin-dependent processes and autoinflammatory disease.Man Lyang Kim, Jae Jin Chae, Yong Hwan Park, Dominic De Nardo, Roslynn A. Stirzaker ... Benjamin T Kile ... et al
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