318 research outputs found

    March1-dependent modulation of donor MHC II on CD103+ dendritic cells mitigates alloimmunity.

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    In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs

    Expression and characterization of Pantoea CO dehydrogenase to utilize CO-containing industrial waste gas for expanding the versatility of CO dehydrogenase

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    Although aerobic CO dehydrogenases (CODHs) might be applicable in various fields, their practical applications have been hampered by low activity and no heterologous expression. We, for the first time, could functionally express recombinant PsCODH in E. coli and obtained a highly concentrated recombinant enzyme using an easy and convenient method. Its electron acceptor spectra, optimum conditions (pH 6.5 and 30 degrees C), and kinetic parameters (k(cat) of 12.97 s(-1), Km of 0.065 mM, and specific activity of 0.86 Umg(-1)) were examined. Blast furnace gas (BFG) containing 20% CO, which is a waste gas from the steel-making process, was tested as a substrate for PsCODH. Even with BFG, the recombinant PsCODH retained 88.2% and 108.4% activity compared with those of pure CO and 20% CO, respectively. The results provide not only a promising strategy to utilize CO-containing industrial waste gases as cheap, abundant, and renewable resources but also significant information for further studies about cascade reactions producing value-added chemicals via CO2 as an intermediate produced by a CODHbased CO-utilization system, which would ultimately expand the versatility of CODH.ope

    Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA

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    Correlations between charged particles in deep inelastic ep scattering have been studied in the Breit frame with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in terms of the angular separation between current-region particles within a cone centred around the virtual photon axis. Long-range correlations between the current and target regions have also been measured. The data support predictions for the scaling behaviour of the angular correlations at high Q2 and for anti-correlations between the current and target regions over a large range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations and Monte Carlo models correctly describe the trends of the data at high Q2, but show quantitative discrepancies. The data show differences between the correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C

    Searches for excited fermions in ep collisions at HERA

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    Searches in ep collisions for heavy excited fermions have been performed with the ZEUS detector at HERA. Excited states of electrons and quarks have been searched for in e^+p collisions at a centre-of-mass energy of 300 GeV using an integrated luminosity of 47.7 pb^-1. Excited electrons have been sought via the decays e*->egamma, e*->eZ and e*->nuW. Excited quarks have been sought via the decays q*->qgamma and q*->qW. A search for excited neutrinos decaying via nu*->nugamma, nu*->nuZ and nu*->eW is presented using e^-p collisions at 318 GeV centre-of-mass energy, corresponding to an integrated luminosity of 16.7 pb^-1. No evidence for any excited fermion is found, and limits on the characteristic couplings are derived for masses below 250 GeV

    Search for n-nbar oscillation in Super-Kamiokande

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    A search for neutron-antineutron (n−nˉn-\bar{n}) oscillation was undertaken in Super-Kamiokande using the 1489 live-day or 2.45×10342.45 \times 10^{34} neutron-year exposure data. This process violates both baryon and baryon minus lepton numbers by an absolute value of two units and is predicted by a large class of hypothetical models where the seesaw mechanism is incorporated to explain the observed tiny neutrino masses and the matter-antimatter asymmetry in the Universe. No evidence for n−nˉn-\bar{n} oscillation was found, the lower limit of the lifetime for neutrons bound in 16{}^{16}O, in an analysis that included all of the significant sources of experimental uncertainties, was determined to be 1.9×10321.9 \times 10^{32}~years at the 90\% confidence level. The corresponding lower limit for the oscillation time of free neutrons was calculated to be 2.7×1082.7 \times 10^8~s using a theoretical value of the nuclear suppression factor of 0.517×10230.517 \times 10^{23}~s−1^{-1} and its uncertainty.Comment: 8 pages, 2 figure

    Search for n-nbar oscillation in Super-Kamiokande

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    A search for neutron-antineutron (n−nˉn-\bar{n}) oscillation was undertaken in Super-Kamiokande using the 1489 live-day or 2.45×10342.45 \times 10^{34} neutron-year exposure data. This process violates both baryon and baryon minus lepton numbers by an absolute value of two units and is predicted by a large class of hypothetical models where the seesaw mechanism is incorporated to explain the observed tiny neutrino masses and the matter-antimatter asymmetry in the Universe. No evidence for n−nˉn-\bar{n} oscillation was found, the lower limit of the lifetime for neutrons bound in 16{}^{16}O, in an analysis that included all of the significant sources of experimental uncertainties, was determined to be 1.9×10321.9 \times 10^{32}~years at the 90\% confidence level. The corresponding lower limit for the oscillation time of free neutrons was calculated to be 2.7×1082.7 \times 10^8~s using a theoretical value of the nuclear suppression factor of 0.517×10230.517 \times 10^{23}~s−1^{-1} and its uncertainty.Comment: 8 pages, 2 figure
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