729 research outputs found

    Characterising the HLA-I Immunopeptidome of plasma-derived extracellular vesicles in patients with melanoma

    Get PDF
    This work was funded by grants from Breast Cancer Now UK (2018JulPR1086), and the Melville Trust for the Care and Cure of Cancer UK (XCT014). We also gratefully acknowledge funding from the EPSRC via EP/L017008/1 for TEM imaging infrastructure, and EP/R023751/1 and EP/T019298/1.Extracellular vesicles (EVs) frequently express human leukocyte antigen class I (HLA-I) molecules. The immunopeptidomes presented on EV HLA-I are being mapped to provide key information on both specific cancer-related peptides, and for larger immunopeptidomic signatures associated with disease. Utilizing HLA-I immunoisolation and mass spectrometry, we characterised the HLA-I immunopeptidome of EVs derived from the melanoma cancer cell line, ESTDAB-026, and the plasma of 12 patients diagnosed with advanced stage melanoma, alongside 11 healthy controls. The EV HLA-I immunopeptidome derived from melanoma cells features T cell epitopes with known immunogenicity and peptides derived from known tumour associated antigens (TAAs). Both T cell epitopes with known immunogenicity and peptides derived from known TAAs were also identifiable in the melanoma patient samples. Patient stratification into two distinct groups with varying immunological profiles was also observed. The data obtained in this study suggests for the first time that the HLA-I immunopeptidome of EVs derived from blood may aid in the detection of important diagnostic or prognostic biomarkers and also provide new immunotherapy targets.Peer reviewe

    Moorean tree snail survival revisited: a multi-island genealogical perspective

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The mass extirpation of the island of Moorea's endemic partulid tree snail fauna, following the deliberate introduction of the alien predator <it>Euglandina rosea</it>, represents one of the highest profile conservation crises of the past thirty years. All of the island's partulids were thought to be extirpated by 1987, with five species persisting in zoos, but intensive field surveys have recently detected a number of surviving wild populations. We report here a mitochondrial (mt) phylogenetic estimate of Moorean partulid wild and captive lineage survival calibrated with a reference museum collection that pre-dates the predator's introduction and that also includes a parallel dataset from the neighboring island of Tahiti.</p> <p>Results</p> <p>Although severe winnowing of Moorea's mt lineage diversity has occurred, seven of eight (six <it>Partula</it>; two <it>Samoana</it>) partulid tip clades remain extant. The extinct mt clade occurred predominantly in the <it>P. suturalis </it>species complex and it represented a major component of Moorea's endemic partulid treespace. Extant Moorean mt clades exhibited a complex spectrum of persistence on Moorea, in captivity, and (in the form of five phylogenetically distinct sister lineages) on Tahiti. Most notably, three <it>Partula </it>taxa, bearing two multi-island mt lineages, have survived decades of <it>E. rosea </it>predation on Moorea (<it>P. taeniata</it>) and in the valleys of Tahiti (<it>P. hyalina </it>and <it>P. clara</it>). Their differential persistence was correlated with intrinsic attributes, such as taxonomy and mt lineages, rather than with their respective within-island distribution patterns.</p> <p>Conclusion</p> <p>Conservation efforts directed toward Moorean and Tahitian partulids have typically operated within a single island frame of reference, but our discovery of robust genealogical ties among survivors on both islands implies that a multi-island perspective is required. Understanding what genetic and/or ecological factors have enabled <it>Partula taeniata</it>, <it>P. hyalina </it>and <it>P. clara </it>to differentially survive long-term direct exposure to the predator may provide important clues toward developing a viable long term conservation plan for Society Island partulid tree snails.</p

    tert-Butyl 2-hy­droxy-3-(4-methyl­benzene­sulfonamido)­butano­ate

    Get PDF
    In the crystal of the title compound, C15H23NO5S, mol­ecules are linked through N—H⋯O and O—H⋯O hydrogen-bond inter­actions, resulting in centrosymmetric dimers in which the N—H⋯O inter­actions generate R 2 2(12) rings and the O—H⋯O inter­actions generate R 2 2(14) rings. Weak inter­molecular C—H⋯O inter­actions are also observed

    (2R,3S)-Methyl 2-hy­droxy-3-(4-methyl­benzene­sulfonamido)-3-phenyl­propano­ate

    Get PDF
    In the title mol­ecule, C17H19NO5S, the p-tolyl ring is oriented approximately parallel to the phenyl ring [dihedral angle = 17.2 (1)°], resulting in an intra­molecular π–π inter­ation [centroid–centroid distance = 3.184 (10) Å]. In the crystal, mol­ecules are linked through O—H⋯O and C—H⋯O hydrogen bonds, forming hydrogen-bonded sheets lying diagonally across the ac face

    cis

    Full text link

    Chain transfer to solvent in the radical polymerization of structurally diverse acrylamide monomers using straight-chain and branched alcohols as solvents

    Get PDF
    Chain transfer to solvent in conventional radical polymerizations of N-tert-butylacrylamide (TBAM) and N-(2-morpholin-4-ylethyl) acrylamide (MEA) in a range of alcohol solvents is investigated. Mayo analysis of polymerization of TBAM in linear alcohols (C-3-C-9) resulted in an approximately linear increase in chain transfer to solvent constant (C-tr,(S)) with the number of methylene (CH2) units in the solvent. The branched alcohol 3-methyl-3-pentanol gave the smallest C-tr,C-S (using Mayo analysis), and thus allowed attainment of higher molecular weights (MWs) in the nitroxide-mediated polymerizations (NMP) of TBAM. Overall, the data show that MEA is more prone to chain transfer to solvent than TBAM (higher C-tr,C-S), and further analysis of the conventional radical polymerization of MEA in 3-methyl-3-pentanol indicate chain transfer to monomer may also be occurring. The first controlled/ living polymerizations of MEA are detailed with chain transfer having a greater impact on maximum achievable MWs in NMP in comparison to TBAM

    Gangliosides Block Aggregatibacter Actinomycetemcomitans Leukotoxin (LtxA)-Mediated Hemolysis

    Get PDF
    Aggregatibacter actinomycetemcomitans is an oral pathogen and etiologic agent of localized aggressive periodontitis. The bacterium is also a cardiovascular pathogen causing infective endocarditis. A. actinomycetemcomitans produces leukotoxin (LtxA), an important virulence factor that targets white blood cells (WBCs) and plays a role in immune evasion during disease. The functional receptor for LtxA on WBCs is leukocyte function antigen-1 (LFA-1), a β-2 integrin that is modified with N-linked carbohydrates. Interaction between toxin and receptor leads to cell death. We recently discovered that LtxA can also lyse red blood cells (RBCs) and hemolysis may be important for pathogenesis of A. actinomycetemcomitans. In this study, we further investigated how LtxA might recognize and lyse RBCs. We found that, in contrast to a related toxin, E. coli α-hemolysin, LtxA does not recognize glycophorin on RBCs. However, gangliosides were able to completely block LtxA-mediated hemolysis. Furthermore, LtxA did not show a preference for any individual ganglioside. LtxA also bound to ganglioside-rich C6 rat glioma cells, but did not kill them. Interaction between LtxA and C6 cells could be blocked by gangliosides with no apparent specificity. Gangliosides were only partially effective at preventing LtxA-mediated cytotoxicity of WBCs, and the effect was only observed when a high ratio of ganglioside:LtxA was used over a short incubation period. Based on the results presented here, we suggest that because of the similarity between N-linked sugars on LFA-1 and the structures of gangliosides, LtxA may have acquired the ability to lyse RBCs
    corecore