41 research outputs found

    Discovery and Differential Processing of HLA Class II-Restricted Minor Histocompatibility Antigen LB-PIP4K2A-1S and Its Allelic Variant by Asparagine Endopeptidase

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    Minor histocompatibility antigens are the main targets of donor-derived T-cells after allogeneic stem cell transplantation. Identification of these antigens and understanding their biology are a key requisite for more insight into how graft vs. leukemia effect and graft vs. host disease could be separated. We here identified four new HLA class II-restricted minor histocompatibility antigens using whole genome association scanning. For one of the new antigens, i.e., LB-PIP4K2A-1S, we measured strong T-cell recognition of the donor variant PIP4K2A-1N when pulsed as exogenous peptide, while the endogenously expressed variant in donor EBV-B cells was not recognized. We showed that lack of T-cell recognition was caused by intracellular cleavage by a protease named asparagine endopeptidase (AEP). Furthermore, microarray gene expression analysis showed that PIP4K2A and AEP are both ubiquitously expressed in a wide variety of healthy tissues, but that expression levels of AEP were lower in primary acute myeloid leukemia (AML). In line with that, we confirmed low activity of AEP in AML cells and demonstrated that HLA-DRB1*03:01 positive primary AML expressing LB-PIP4K2A-1S or its donor variant PIP4K2A-1N were both recognized by specific T-cells. In conclusion, LB-PIP4K2A-1S not only represents a novel minor histocompatibility antigen but also provides evidence that donor T-cells after allogeneic stem cell transplantation can target the autologous allelic variant as leukemia-associated antigen. Furthermore, it demonstrates that endopeptidases can play a role in cell type-specific intracellular processing and presentation of HLA class II-restricted antigens, which may be explored in future immunotherapy of AML

    Deficient methylation and formylation of mt-tRNA(Met) wobble cytosine in a patient carrying mutations in NSUN3.

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    Epitranscriptome modifications are required for structure and function of RNA and defects in these pathways have been associated with human disease. Here we identify the RNA target for the previously uncharacterized 5-methylcytosine (m(5)C) methyltransferase NSun3 and link m(5)C RNA modifications with energy metabolism. Using whole-exome sequencing, we identified loss-of-function mutations in NSUN3 in a patient presenting with combined mitochondrial respiratory chain complex deficiency. Patient-derived fibroblasts exhibit severe defects in mitochondrial translation that can be rescued by exogenous expression of NSun3. We show that NSun3 is required for deposition of m(5)C at the anticodon loop in the mitochondrially encoded transfer RNA methionine (mt-tRNA(Met)). Further, we demonstrate that m(5)C deficiency in mt-tRNA(Met) results in the lack of 5-formylcytosine (f(5)C) at the same tRNA position. Our findings demonstrate that NSUN3 is necessary for efficient mitochondrial translation and reveal that f(5)C in human mitochondrial RNA is generated by oxidative processing of m(5)C.This work was funded by the Medical Research Council (MRC; as part of the core funding for the Mitochondrial Biology Unit MC_U105697135 and by the G0801904 grant), the European Research Council (ERC; 310360), Cancer Research UK (CR-UK; C10701/ A15181), European Commission (FP7/2007-2013, under grant agreement number no.262055 (ESGI), as a Transnational Access project of the European Sequencing and Genotyping Infrastructure), core support grant from the Wellcome Trust and MRC to the Wellcome Trust-MRC Cambridge Stem Cell Institute, the European Commission (Horizon2020, under grant agreement number 633974), the Bundesministerium fur Bildung und Forschung (BMBF) (through the German Network for mitochondrial disorders (mitoNET, 01GM1113C) and through the European network for mitochondrial disorders (E-Rare project GENOMIT, 01GM1207)) and by EMBO (ALFT 701-2013).This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/ncomms1203

    Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction

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    A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.</p

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Measurement of jet fragmentation in Pb+Pb and pppp collisions at sNN=2.76\sqrt{{s_\mathrm{NN}}} = 2.76 TeV with the ATLAS detector at the LHC

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    Lizenz-Controlling für Software: Wirksames IT-Kostenmanagement durch effizientes Software-Assetmanagement

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    Viele Controller verzeichnen steigende IT-Kosten, die zum Teil durch Lizenzkosten verursacht werden. Oft werden Kosteneinsparungen durch ineffizientes oder fehlendes Lizenzmanagement nicht realisiert, zudem sehen sich zahlreiche Unternehmen zusehends mit dem Problem nicht budgetierter Nachlizenzierungen, aufgrund steigender Aktivitäten der Softwarehersteller im Bereich der Lizenzierungsüberprüfung, konfrontiert. Der Beitrag zeigt die Problematik des IT-Lizenzmanagements und grundsätzliche Lösungsmöglichkeiten auf. Ein Referenzmodell demonstriert, wie im praktischen Anwendungsfall eine Kostensenkung und Prozessverbesserung realisiert werden kann

    Cerebellar Cognitive Affective Syndrome and Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay:A Report of Two Male Sibs

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    Item does not contain fulltextBackground: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare neurodegenerative disorder caused by mutations in the SACS gene (13q12) encoding the protein sacsin. It is characterized by early-onset cerebellar ataxia, lower limb spasticity, sensorimotor axonal polyneuropathy, and atrophy of the superior cerebellar vermis. Cerebellar disorders in general may be accompanied by the cerebellar cognitive affective syndrome (CCAS) which presents with disturbances of executive functioning, spatial cognition, linguistic capacities, and affect. Sampling and Methods: Two middle-aged brothers with ARSACS, one of whom was referred for behavioral disinhibition, are described. A detailed neuropsychiatric and neuropsychological assessment was performed. Results: Apart from motor symptoms, motivational deficits along with cognitive and behavioral dysfunctions were present; these were much more pronounced in the older sib. Conclusions: These observations add to the literature which suggests that the cerebellum, apart from its significance for motor behavior, plays a functional role in human cognition and affect. The nonmotor symptoms of ARSACS are discussed in terms of the CCAS.7 p

    Exact CT-based liver volume calculation including nonmetabolic liver tissue in three-dimensional liver reconstruction

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    Exact preoperative determination of the liver volume is of great importance prior to hepatobiliary surgery, especially in living donated liver transplantation (LDLT) and extended hepatic resections. Modern surgery-planning systems estimate these volumes from segmented image data. In an experimental porcine study, our aim was (1) to analyze and compare three volume measurement algorithms to predict total liver volume, and (2) to determine vessel tree volumes equivalent to nonmetabolic liver tissue. Twelve porcine livers were examined using a standardized three-phase computed tomography (CT) scan and liver volume was calculated computer-assisted with the three different algorithms. After hepatectomy, livers were weighed and their vascular system plasticized followed by CT scan, CT reconstruction and re-evaluation of total liver and vessel volumes with the three different algorithms. Blood volume determined by the plasticized model was at least 1.89 times higher than calculated by multislice CT scans (9.7% versus 21.36%, P=0.028). Analysis of 3D-CT-volumetry showed good correlation between the actual and the calculated liver volume in all tested algorithms with a high significant difference in estimating the liver volume between Heymsfield versus Heidelberg (P=0.0005) and literature versus Heidelberg (P=0.0060). The Heidelberg algorithm reduced the measuring error with deviations of only 1.2%. The present results suggest a safe and highly predictable use of 3D-volumetry in liver surgery for evaluating liver volumes. With a precise algorithm, the volume of remaining liver or single segments can be evaluated exactly and potential operative risks can therefore be better calculated. To our knowledge, this study implies for the first time a blood pool, which corresponds to nonmetabolic liver tissue, of more than 20% of the whole liver volume
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