Identification of physiologically relevant peptide vaccine targets calls for the direct analysis of the entirety of naturally presented human leukocyte antigen (HLA) ligands, termed the HLA ...ligandome. In this study, we implemented this direct approach using immunoprecipitation and mass spectrometry to define acute myeloid leukemia (AML)-associated peptide vaccine targets. Mapping the HLA class I ligandomes of 15 AML patients and 35 healthy controls, more than 25 000 different naturally presented HLA ligands were identified. Target prioritization based on AML exclusivity and high presentation frequency in the AML cohort identified a panel of 132 LiTAAs (ligandome-derived tumor-associated antigens), and 341 corresponding HLA ligands (LiTAPs (ligandome-derived tumor-associated peptides)) represented subset independently in >20% of AML patients. Functional characterization of LiTAPs by interferon-γ ELISPOT (Enzyme-Linked ImmunoSpot) and intracellular cytokine staining confirmed AML-specific CD8(+) T-cell recognition. Of note, our platform identified HLA ligands representing several established AML-associated antigens (e.g. NPM1, MAGED1, PRTN3, MPO, WT1), but found 80% of them to be also represented in healthy control samples. Mapping of HLA class II ligandomes provided additional CD4(+) T-cell epitopes and potentially synergistic embedded HLA ligands, allowing for complementation of a multipeptide vaccine for the immunotherapy of AML.
The antigenic makeup of tumour cells can have a profound effect on the progression of cancer and success of immunotherapies. Therefore, one strategy to improve the efficacy of cancer treatments is to ...augment the antigens displayed by tumours. The present study explores how the recognition of tumour cells may be altered by non-cytotoxic concentrations of gemcitabine (GEM). Testing a panel of chemotherapeutics in human cancer cell lines in vitro, it was found that GEM increased surface expression of HLA-A,B,C and that underlying this were specific increases in β-2-microglobulin and immunoproteasome subunit proteins. Furthermore, the peptide antigen repertoire displayed on HLA class I was altered, revealing a number of novel antigens, many of which that were derived from proteins involved in the DNA-damage response. Changes in the nature of the peptide antigens eluted from HLA-A,B,C after GEM treatment consisted of amino acid anchor-residue modifications and changes in peptide length which rendered peptides likely to favour alternative HLA-alleles and increased their predicted immunogenicity. Signalling through the MAPK/ERK and NFκB/RelB pathways was associated with these changes. These data may explain observations made in previous in vivo studies, advise as to which antigens should be used in future vaccination protocols and reinforce the idea that chemotherapy and immunotherapy could be used in combination.
Natural killer (NK) cells are cytotoxic lymphocytes that substantially contribute to the therapeutic benefit of antitumor antibodies like Rituximab, a crucial component in the treatment of B-cell ...malignancies. In chronic lymphocytic leukemia (CLL), the ability of NK cells to lyse the malignant cells and to mediate antibody-dependent cellular cytotoxicity upon Fc receptor stimulation is compromised, but the underlying mechanisms are largely unclear. We report here that NK-cells activation-dependently produce the tumor necrosis factor family member 'B-cell activating factor' (BAFF) in soluble form with no detectable surface expression, also in response to Fc receptor triggering by therapeutic CD20-antibodies. BAFF in turn enhanced the metabolic activity of primary CLL cells and impaired direct and Rituximab-induced lysis of CLL cells without affecting NK reactivity per se. The neutralizing BAFF antibody Belimumab, which is approved for treatment of systemic lupus erythematosus, prevented the effects of BAFF on the metabolism of CLL cells and restored their susceptibility to direct and Rituximab-induced NK-cell killing in allogeneic and autologous experimental systems. Our findings unravel the involvement of BAFF in the resistance of CLL cells to NK-cell antitumor immunity and Rituximab treatment and point to a benefit of combinatory approaches employing BAFF-neutralizing drugs in B-cell malignancies.
The role of Sn on the catalytic activity for CO and formic acid oxidation is studied by comparing the activities of differently treated PtSn/C and Pt/C catalysts. The catalysts are prepared by a ...microwave-assisted polyol synthesis method. As revealed by scanning tunneling and transmission electron microscopic (STM and TEM) characterization, the outcomes of the synthesis procedure for both Pt and PtSn are small particles, ∼1.5 nm in diameter. Upon deposition on the carbon support, the particle size increases to ∼2.5 nm due to sintering. X-ray diffraction (XRD) analysis shows that PtSn/C has a low alloying degree and is mainly composed of Pt and Pt3Sn phases. The remaining Sn is present in the form of very small tin oxide particles. Different surfaces are obtained by double-layer, oxide, and CO annealing of the Pt/C and PtSn/C catalysts and by modifying the CO-annealed surfaces with irreversibly adsorbed tin, Snirr. The presence of Sn in any form (oxide, alloyed, or Snirr) on the surface shifts the onset potential for the CO oxidation negatively by more than 0.4 V in comparison to equivalently treated Pt/C catalysts. For the CO-annealed PtSn/C catalyst, a so-called skeleton structure, Sn is present only in the subsurface layers. The subsurface Sn has a mild effect on the CO activity, and hence the onset potential is only marginally shifted to cathodic potentials by ∼50 mV compared to that on Pt/C. The formic acid oxidation is enhanced at any of the PtSn/C surfaces with Sn in the surface layer. The activity enhancement is explained by a reduced CO poisoning of the surface Pt sites. As a consequence, the current is not entering plateau as on the Pt/C catalysts. Furthermore, the skeleton PtSn/C is ∼2 times more active than similarly treated Pt/C. The results have been substantiated and explained by comprehensive density functional theory (DFT) simulations. The DFT results indicate that the increased oxidation rates are not only due to surface Sn but also due to a weakened CO binding in the vicinity of the surface SnOH x moieties and SnO2 particles.
Esomeprazole is the most effective of the proton-pump inhibitors for the acid-related diseases and at first was examined for the electroanalytical purposes. The drug standard and as a content of ...injection powder was investigated by cyclic voltammetry (CV) and quantitatively determined using square wave voltammetry (SWV) via its electrooxidation at Au electrode in 0.05M NaHCO3. SWV showed a linear dependency of the anodic peak currents vs. esomeprazole standard concentrations in the range from 3.0 to 500μgmL−1 with the values of limit of detection (LOD) and limit of quantification (LOQ): 1.4 and 4.6μgmL−1, respectively. Using the constructed and validated calibration curve, the values of unknown esomeprazole concentrations in injection powder and in human serum spiked with standard were determined. Before the electrochemical oxidation, it was shown by atomic force microscopy (AFM) that the small esomeprazole islands formed inside holes were visible and their diameter was about 200nm attributed to physico-chemical characteristics of esomeprazole. After the electrochemical oxidation, the morphology of esomeprazole standard on Au surface was completely changed and composed of spherical particles in a diameter between 200 and 600nm. With esomeprazole suspended in human serum, the process of crystallization partly occurred in the form of spherical grains with the average size of these grains was about 4μm. The analysis at the macro level done by the optical microscopy (OM) confirmed this opinion.
The study of esomeprazole degradation showed that at Au electrode, after 3h of cycling, a neglectable amount of the esomeprazole was changed. Using IrOx electrode under directed stress conditions, its almost complete degradation was realized after 3h confirmed by high performance liquid chromatography (HPLC). Total organic carbon (TOC) analysis showed that 95% of esomeprazole was mineralized. The HPLC and Liquid chromatography-mass spectrometry (LC-MS) study revealed the formation of 4-hydroxy omeprazole sulphide, 4-hydroxy omeprazole sulphone, esomeprazole sulphone and methylated esomeprazole.
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•SWV method for esomeprazole determination using Au electrode was developed.•Method was applied for esomeprazole determination in human serum/injection powder.•Morphology of Au electrode surface during study was characterized by AFM and OM.•Esomeprazole degradation at IrOx electrode led to 95% of its mineralization.•Several degradation products were detected by HPLC and LCMS analysis.
► Corrosion of Zn–Mn alloys deposited from alkaline solution was examined for the first time. ► Deposits are mixture of η- and ε-ZnMn phases. The increase in deposition current density increases ...ε-phase content. ► Corrosion product on Zn–Mn alloys in NaCl solution is Zn
5(OH)
8Cl
2·H
2O. ► Coating deposited at higher current density has lower corrosion stability due to more porous surface film. ► Cavities and discrete large clusters in deposit, result in non-compact passive layer.
The effects of a deposition current density (c.d
.) on the corrosion behaviour of Zn–Mn alloy coatings, deposited from alkaline pyrophosphate solution, were investigated by atomic absorption spectrophotometry (AAS), X-ray diffraction (XRD), atomic force microscopy (AFM), optical microscopy, electrochemical impedance spectroscopy (EIS) and measurement of corrosion potential (
E
corr). XRD analysis disclosed that zinc hydroxide chloride was the main corrosion product on Zn–Mn coatings immersed in 0.5
mol
dm
−3 NaCl solution. EIS investigations revealed that less porous protective layer was produced on the alloy coating deposited at c.d
. of 30
mA
cm
−2 as compared to that deposited at 80
mA
cm
−2.
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•Role of oxides in La/Co/(Sr) US/pyrolytically synthesized oxide powders is examined.•The particles become more spherical with increased temperature.•The aggregation of the particles ...is less pronounced with increased temperature.•Csp is higher for the samples containing Sr as perovskite structure promoter.•Capacitive stability and rate capability are lower for the samples of higher Csp.
The role and influence of strontium and its oxide on structure and capacitive response of materials containing mixed lanthanum cobalt oxides, LC, and lanthanum strontium cobalt oxides, LSC, as a capacitive materials were investigated in this study. The mixed oxides were synthesized by the single-step ultrasonic spray pyrolysis (USP) technique. The microstructures and electrochemical properties of the samples were characterized by X-ray diffraction, scanning electron microscopy, cyclic voltammetry, potentiostatic electrochemical impedance spectroscopy and galvanostatic charge/discharge cycling. It was found that strontium oxide induces the formation of the perovskite structure of promoted pseudocapacitive behavior over an enhancement of redox transitions of cobalt. The measurements showed that the capacitive stability and rate capability were lower for the samples of higher specific capacitance. Among the prepared materials, the LSC prepared at a USP temperature 600 °C showed the best capacitive characteristics in 0.10 M KOH due to having the most defined spherical perovskite structure leading to well-defined reversible charge–discharge performances.
In-situ synthesis of HAp/TiO2 coating on titanium was performed via anaphoretic deposition of HAp and simultaneous anodization of Ti to produce highly adherent and strengthened composite coating. The ...prepared coatings were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and electron dispersive spectroscopy. HAp on anodized titanium was prepared at constant voltage of 60 V and deposition time of 45 s, which provided uniform and adherent HAp/TiO2 composite coating on Ti. Since smaller size of HAp crystals within highly porous coating structures is of improved binding ability to various biomolecules, our coating is expected to be of excellent coverage and compactness. The obtained coating can be good candidate for bone implants due to reduced brittleness and improved adhesion.
•In-situ synthesis of hydroxyapatite/TiO2 coating on Ti via anaphoretic deposition•Simultaneous deposition of HAp and anodization of Ti•Highly adherent, compact and strengthened composite coating was obtained.•Improved adhesion compared to cataphoretic hydroxyapatite coatings•Excellent coating coverage
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•Nano calcium phosphate/titanium oxide/chitosan oligosaccharide lactate composites.•Novel in situ one-step anaphoretic electrodeposition with improved adhesion.•Transformation of ...amorphous calcium phosphate to hydroxyapatite.
In this paper novel in situ one-step simultaneous anaphoretic deposition process of amorphous calcium phosphate (ACP) and titanium oxide (TiOx) with and without chitosan oligosaccharide lactate (ChOL) on titanium substrate was performed. The coatings were investigated by SEM, XRD and FTIR techniques, whereas roughness and adhesion were measured. It was shown that novel process occurs, with improved coatings adhesion and excellent coverage of the surface. At 90 V the surface is smoother, and there is possibility for crystallization of the components at prolonged deposition times.
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