3,551 research outputs found

    Polymorphonuclear myeloid-derived suppressor cells limit antigen crosspresentation by dendritic cells in cancer

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    DCs are a critical component of immune responses in cancer primarily due to their ability to cross-present tumor-associated antigens. Cross-presentation by DCs in cancer is impaired, which may represent one of the obstacles for the success of cancer immunotherapies. Here, we report that polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) blocked crosspresentation by DCs without affecting direct presentation of antigens by these cells. This effect did not require direct cell-cell contact and was associated with transfer of lipids. Neutrophils (PMN) and PMN-MDSC transferred lipid to DCs equally well; however, PMN did not affect DC cross-presentation. PMN-MDSC generate oxidatively truncated lipids previously shown to be involved in impaired cross-presentation by DCs. Accumulation of oxidized lipids in PMN-MDSC was dependent on myeloperoxidase (MPO). MPO-deficient PMN-MDSC did not affect cross-presentation by DCs. Cross-presentation of tumor-associated antigens in vivo by DCs was improved in MDSC-depleted or tumor-bearing MPO-KO mice. Pharmacological inhibition of MPO in combination with checkpoint blockade reduced tumor progression in different tumor models. These data suggest MPO-driven lipid peroxidation in PMN-MDSC as a possible non–cell autonomous mechanism of inhibition of antigen cross-presentation by DCs and propose MPO as potential therapeutic target to enhance the efficacy of current immunotherapies for patients with cancer

    Association of Toll-Like Cell Receptors TLR2 (p.Arg753GLN) and TLR4 (p.Asp299GLY) Polymorphisms with Indicators of General and Local Immunity in Patients with Atopic Dermatitis

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    © 2017 Yury A. Tyurin et al.A whole group of polymorphisms of genes involved in the formation of the epidermal barrier, immune responses, and their regulation is important in the formation of atopic phenotype. The purpose of the study is to determine the relationship of polymorphisms of genes of Toll-like receptors TLR2 and TLR4 with clinical and immunological parameters in atopic dermatitis patients in a "case-control" study. Polymorphisms of genes TLR2 (p.Arg753Gln) and TLR4 (Asp299Gly) were detected by PCR. Parameters of the state of innate and adaptive immunity were assessed by the level of local production of sIgA, cytokine profile of blood serum for IL-4, IL-10, and IFN-γ. Biological samples from 50 people with allergic pathology, aged 4.5 to 35 years, and 100 healthy individuals (controls) were analyzed. Observed dysregulation of cytokine production (IL-4, IL-10) in patients with heterozygous polymorphic genotypes probably reflects an imbalance of Th1/Th2/Th17 regulation of immune system response in these individuals

    Study of internal structures of 9,10Be and 10B in scattering of 4He from 9Be

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    A study of inelastic scattering and single-particle transfer reactions was performed by an alpha beam at 63 MeV on a 9$Be target. Angular distributions of the differential cross sections for the 9Be(4He,4He')9Be*, 9Be(4He,3He)10Be and 9Be(4He,t)10B reactions were measured. Experimental angular distributions of the differential cross sections for the ground state and a few low-lying states were analyzed in the framework of the optical model, coupled channels and distorted-wave Born approximation. An analysis of the obtained spectroscopic factors was performed.Comment: 16 pages, 7 figures, 3 tables, regular paper, mispritns are corrected in new versio

    Improvement of bait method for isolation of entomopathogenic fungi from soil

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    An increase of the sensitivity of the bait method of entomopathogenic fungi isolation from the soil was registered under the use of larvae Galleria mellonella envenomated by ectoparasitoid Habrobracon hebetor. Further, modified method will allow to isolate fungi from soil with low titer of colony forming unit, particularly from steppes soils.Работа выполнена при финансовой поддержке РФФИ (проект 15–04–02322_а) и Президента РФ (МК–6278.2015.4.)

    Search for states with enlarged radii in excited states of 12B

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    An experiment was done to search for states with a neutron halo in 12B. The measurements were carried out at the cyclotron of the University of Jyvaskyla (Finland) using Large Scattering Chamber (LSC). The idea of the work was to search for two states with the expected neutron halo, 1 ̄ and 2 ̄. Differential cross sections with excitation of 12B states, including abovementioned states, were observed. The preliminary calculations on halo radii by the method of asymptotic normalization coefficients for the 2 ̄ and 1 ̄ states which are in a discrete spectrum gave following values: 5.6 fm and 7.4 fm, which is much larger than the radius of the valence neutron in the ground state. But strictly the presence of a neutron halo can be confirmed only for 1 ̄ state. The 2 ̄ state can be considered only as candidate for halo. An unexpected result was obtained for the 3 ̄, 3.39 MeV state, which is in continuum 19 keV above the decay threshold 12B → 11B + n, preliminary estimation for its halo radius is ∼ 6.5 fm. This indicates that the halo can be present in this state as well. But strict conditions for neutron halo are not fulfilled in the same way as for 2 ̄ state. Until now, the neutron halo in unbound states has been observed only for the members of the rotational bands

    Mechanism of single-spin asymmetries generation in the inclusive hadron processes

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    We discuss a nonperturbative mechanism for generation of the single-spin asymmetries in hadron interactions. It is based on the chiral quark model combined with unitarity and impact parameter picture and provides explanation for the experimental regularities observed under the measurements of the spin asymmetries.Comment: 20 pages, 7 figure

    Structure and microhardness of titanium-based coatings formed by multichamber detonation sprayer

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    A series of titanium-based coatings (50-550 m thick) on an aluminium substrate was deposited via multichamber detonation sprayer with different barrel lengths (300, 400, and 500, all in mm). The titanium-based coatings obtained in these three experiments were examined by optical microscopy, scanning electron microscopy, and X-ray phase analysi

    On asymmetry in inclusive pion production

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    On the basis of the mechanism proposed for one-spin asymmetries in inclusive hadron production we specify an xx--dependence of asymmetries in inclusive processes of pion production. The main role in generation of this asymmetry belongs to the orbital angular momentum ofquark-antiquark cloud in internal structure of constituent quarks. The xx--dependence of asymmetries in the charged pion production at large xx reflects the corresponding dependence of constituent quark polarization in the polarized proton.Comment: LaTeX, 8 pages, 3 figures. One figure added, as it appears in Phys. Rev.

    On impact parameter dependence of low-x structure functions

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    We consider impact parameter dependence of the polarized and unpolarized structure functions. Unitarity does not allow factorization of the structure functions over the Bjorken x and the impact parameter b variables. On the basis of the particular geometrical model approach we conclude that spin of constituent quark may have a significant orbital angular momentum component which can manifest itself through the peripherality of the spin dependent structure functions.Comment: 5 pages, 1 figur
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