This is the institutional Repository of the Helmholtz Centre for Infection Research in Braunschweig/Germany (HZI), the Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarbrücken/Germany, the TWINCORE Zentrum für Exprerimentelle und Klinische Infektionsforschung, Hannover/Germany,Helmholtz-Institut für RNA-basierte Infektionsforschung (HIRI), BRICS, CSSB and the Study Centre Hannover, Hannover/Germany.

 

  • Chronic hepatitis C virus infection irreversibly impacts human natural killer cell repertoire diversity.

    Strunz, Benedikt; Hengst, Julia; Deterding, Katja; Manns, Michael P; Cornberg, Markus; Ljunggren, Hans-Gustaf; Wedemeyer, Heiner; Björkström, Niklas K; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-06-11)
    Diversity is a central requirement for the immune system's capacity to adequately clear a variety of different infections. As such, natural killer (NK) cells represent a highly diverse population of innate lymphocytes important in the early response against viruses. Yet, the extent to which a chronic pathogen affects NK cell diversity is largely unknown. Here we study NK cell functional diversification in chronic hepatitis C virus (HCV) infection. High-dimensional flow cytometer assays combined with stochastic neighbor embedding analysis reveal that chronic HCV infection induces functional imprinting on human NK cells that is largely irreversible and persists long after successful interventional clearance of the virus. Furthermore, HCV infection increases inter-individual, but decreases intra-individual, NK cell diversity. Taken together, our results provide insights into how the history of infections affects human NK cell diversity.
  • CRP-cAMP mediates silencing of Salmonella virulence at the post-transcriptional level.

    El Mouali, Youssef; Gaviria-Cantin, Tania; Sánchez-Romero, María Antonia; Gibert, Marta; Westermann, Alexander J; Vogel, Jörg; Balsalobre, Carlos; HIRI, Helmoltz-Institut für RNA-basierteInfektionsforschung, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany. (2018-01-01)
    Invasion of epithelial cells by Salmonella enterica requires expression of genes located in the pathogenicity island I (SPI-1). The expression of SPI-1 genes is very tightly regulated and activated only under specific conditions. Most studies have focused on the regulatory pathways that induce SPI-1 expression. Here, we describe a new regulatory circuit involving CRP-cAMP, a widely established metabolic regulator, in silencing of SPI-1 genes under non-permissive conditions. In CRP-cAMP-deficient strains we detected a strong upregulation of SPI-1 genes in the mid-logarithmic growth phase. Genetic analyses revealed that CRP-cAMP modulates the level of HilD, the master regulator of Salmonella invasion. This regulation occurs at the post-transcriptional level and requires the presence of a newly identified regulatory motif within the hilD 3'UTR. We further demonstrate that in Salmonella the Hfq-dependent sRNA Spot 42 is under the transcriptional repression of CRP-cAMP and, when this transcriptional repression is relieved, Spot 42 exerts a positive effect on hilD expression. In vivo and in vitro assays indicate that Spot 42 targets, through its unstructured region III, the 3'UTR of the hilD transcript. Together, our results highlight the biological relevance of the hilD 3'UTR as a hub for post-transcriptional control of Salmonella invasion gene expression.
  • Two novel species of (Parabambusicolaceae, Pleosporales) with their phoma-like asexual morphs.

    Phukhamsakda, Chayanard; Bhat, Darbhe J; Hongsanan, Sinang; Xu, Jian-Chu; Stadler, Marc; Hyde, Kevin D; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-01-01)
    The monotypic genus
  • Metatranscriptome Analysis of the Vaginal Microbiota Reveals Potential Mechanisms for Protection against Metronidazole in Bacterial Vaginosis.

    Deng, Zhi-Luo; Gottschick, Cornelia; Bhuju, Sabin; Masur, Clarissa; Abels, Christoph; Wagner-Döbler, Irene; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-06-27)
    Bacterial vaginosis (BV) is a prevalent multifactorial disease of women in their reproductive years characterized by a shift from the
  • Efficient Two Step β-Glycoside Synthesis from -Acetyl -Glucosamine: Scope and Limitations of Copper(II) Triflate-Catalyzed Glycosylation

    Sommer, Roman; Hauck, Dirk; Titz, Alexander; HIPS, Helmholtz-Institute für pharmazeutische Forschung Saarland, Universitätscampus E8.1, 66123 Saarbrücken, Germany.
    β‐Linked glycosides of N‐acetyl glucosamine are widespread in nature. Their direct synthesis is hampered by the low reactivity of GlcNAc as a glycosyl donor. We report a selective and rapid copper(II) triflate‐catalyzed two‐step synthesis of β‐glycosides of GlcNAc from cheap GlcNAc as starting material without purification of intermediates. α‐Specific glycosylation can be achieved by increasing the amount of catalyst and extending reaction times.

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