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), Würzburg/Germany, Braunschweig Integrated Centre for Systems biology (BRICS), Centre for Structural Systems Biology (CSSB) the Study Centre Hannover, Hannover/Germany and the Centre for Individualised Infection Medicine (CiiM).


  • Antimicrobial resistance dynamics and the one-health strategy: a review

    Singh, Kumar Siddharth; Anand, Santosh; Dholpuria, Sunny; Sharma, Jitendra Kumar; Blankenfeldt, Wulf; Shouche, Yogesh; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Springer Science and Business Media LLC, 2021-04-15)
    Antimicrobial resistance is a global threat that kills at least 75,000 people every year worldwide and causes extended hospital stays. In the coming 10 years, antimicrobial resistance is projected to have huge health and economic burden on countries, and the scarcity of available antibiotics further worsens the situation. Antimicrobial resistance results mainly from indiscriminate antibiotic usage in humans, animals and agriculture, and from the rapid emergence and dissemination of resistant pathogens. This issue is challenging for antibiotic stewardship, strict regulations on antibiotics usage, large-scale surveillance and responsible public behavior. This demands international cooperation and integrated efforts under the ‘one-health’ strategy. Here, we review antimicrobial resistance and the one-health strategy. We discuss the historical issue of using antibiotics. We highlight the effectiveness of hygiene in livestock rearing, careful antibiotic usage and large-scale surveillance of animals, humans and environment domains. We present strategies for mitigation of antimicrobial resistance, exemplified by the successful ban of triclosan which induced a significant decline of resistant pathogens. We emphasize the benefits of the global antibiotic resistance partnership and of the one-health participation of stakeholders from public, healthcare professionals and government to mitigate antimicrobial resistance.
  • Direct conversion of porcine primary fibroblasts into hepatocyte-like cells.

    Fráguas-Eggenschwiler, Mariane; Eggenschwiler, Reto; Söllner, Jenny-Helena; Cortnumme, Leon; Vondran, Florian W R; Cantz, Tobias; Ott, Michael; Niemann, Heiner; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Nature Research, 2021-04-29)
    The pig is an important model organism for biomedical research, mainly due to its extensive genetic, physiological and anatomical similarities with humans. Until date, direct conversion of somatic cells into hepatocyte-like cells (iHeps) has only been achieved in rodents and human cells. Here, we employed lentiviral vectors to screen a panel of 12 hepatic transcription factors (TF) for their potential to convert porcine fibroblasts into hepatocyte-like cells. We demonstrate for the first time, hepatic conversion of porcine somatic cells by over-expression of CEBPα, FOXA1 and HNF4α2 (3TF-piHeps). Reprogrammed 3TF-piHeps display a hepatocyte-like morphology and show functional characteristics of hepatic cells, including albumin secretion, Dil-AcLDL uptake, storage of lipids and glycogen and activity of cytochrome P450 enzymes CYP1A2 and CYP2C33 (CYP2C9 in humans). Moreover, we show that markers of mature hepatocytes are highly expressed in 3TF-piHeps, while fibroblastic markers are reduced. We envision piHeps as useful cell sources for future studies on drug metabolism and toxicity as well as in vitro models for investigation of pig-to-human infectious diseases.
  • The Immunomodulatory CEA Cell Adhesion Molecule 6 (CEACAM6/CD66c) Is a Protein Receptor for the Influenza a Virus.

    Rahman, Shah Kamranur; Ansari, Mairaj Ahmed; Gaur, Pratibha; Ahmad, Imtiyaz; Chakravarty, Chandrani; Verma, Dileep Kumar; Sharma, Anshika; Chhibber, Sanjay; Nehal, Naila; Wirth, Dagmar; et al. (MDPI, 2021-04-21)
    To establish a productive infection in host cells, viruses often use one or multiple host membrane glycoproteins as their receptors. For Influenza A virus (IAV) such a glycoprotein receptor has not been described, to date. Here we show that IAV is using the host membrane glycoprotein CD66c as a receptor for entry into human epithelial lung cells. Neuraminidase (NA), a viral spike protein, binds to CD66c on the cell surface during IAV entry into the host cells. Lung cells overexpressing CD66c showed an increase in virus binding and subsequent entry into the cell. Upon comparison, CD66c demonstrated higher binding capacity than other membrane glycoproteins (EGFR and DC-SIGN) reported earlier to facilitate IAV entry into host cells. siRNA mediated knockdown of CD66c from lung cells inhibited virus binding on cell surface and entry into cells. Blocking CD66c by antibody on the cell surface resulted in decreased virus entry. We found that CD66c is a specific glycoprotein receptor for influenza A virus that did not affect entry of non-IAV RNA virus (Hepatitis C virus). Finally, IAV pre-incubated with recombinant CD66c protein when administered intranasally in mice showed decreased cytopathic effects in mice lungs. This publication is the first to report CD66c (Carcinoembryonic cell adhesion molecule 6 or CEACAM6) as a glycoprotein receptor for Influenza A virus.
  • Establishment, Validation, and Initial Application of a Sensitive LC-MS/MS Assay for Quantification of the Naturally Occurring Isomers Itaconate, Mesaconate, and Citraconate.

    Winterhoff, Moritz; Chen, Fangfang; Sahini, Nishika; Ebensen, Thomas; Kuhn, Maike; Kaever, Volkhard; Bähre, Heike; Pessler, Frank; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (MDPI, 2021-04-26)
    Itaconate is derived from the tricarboxylic acid (TCA) cycle intermediate cis-aconitate and links innate immunity and metabolism. Its synthesis is altered in inflammation-related disorders and it therefore has potential as clinical biomarker. Mesaconate and citraconate are naturally occurring isomers of itaconate that have been linked to metabolic disorders, but their functional relationships with itaconate are unknown. We aimed to establish a sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay for the quantification of itaconate, mesaconate, citraconate, the pro-drug 4-octyl-itaconate, and selected TCA intermediates. The assay was validated for itaconate, mesaconate, and citraconate for intra- and interday precision and accuracy, extended stability, recovery, freeze/thaw cycles, and carry-over. The lower limit of quantification was 0.098 µM for itaconate and mesaconate and 0.049 µM for citraconate in 50 µL samples. In spike-in experiments, itaconate remained stable in human plasma and whole blood for 24 and 8 h, respectively, whereas spiked-in citraconate and mesaconate concentrations changed during incubation. The type of anticoagulant in blood collection tubes affected measured levels of selected TCA intermediates. Human plasma may contain citraconate (0.4-0.6 µM, depending on the donor), but not itaconate or mesaconate, and lipopolysaccharide stimulation of whole blood induced only itaconate. Concentrations of the three isomers differed greatly among mouse organs: Itaconate and citraconate were most abundant in lymph nodes, mesaconate in kidneys, and only citraconate occurred in brain. This assay should prove useful to quantify itaconate isomers in biomarker and pharmacokinetic studies, while providing internal controls for their effects on metabolism by allowing quantification of TCA intermediates.
  • In vivo targets of Salmonella FinO include a FinP-like small RNA controlling copy number of a cohabitating plasmid.

    El Mouali, Youssef; Gerovac, Milan; Mineikaitė, Raminta; Vogel, Jörg; HIRI, Helmholtz-Institut für RNA-basierte Infektionsforschung, Josef-Shneider Strasse 2, 97080 Würzburg, Germany. (Oxford Academic, 2021-05-03)
    FinO-domain proteins represent an emerging family of RNA-binding proteins (RBPs) with diverse roles in bacterial post-transcriptional control and physiology. They exhibit an intriguing targeting spectrum, ranging from an assumed single RNA pair (FinP/traJ) for the plasmid-encoded FinO protein, to transcriptome-wide activity as documented for chromosomally encoded ProQ proteins. Thus, the shared FinO domain might bear an unusual plasticity enabling it to act either selectively or promiscuously on the same cellular RNA pool. One caveat to this model is that the full suite of in vivo targets of the assumedly highly selective FinO protein is unknown. Here, we have extensively profiled cellular transcripts associated with the virulence plasmid-encoded FinO in Salmonella enterica. While our analysis confirms the FinP sRNA of plasmid pSLT as the primary FinO target, we identify a second major ligand: the RepX sRNA of the unrelated antibiotic resistance plasmid pRSF1010. FinP and RepX are strikingly similar in length and structure, but not in primary sequence, and so may provide clues to understanding the high selectivity of FinO-RNA interactions. Moreover, we observe that the FinO RBP encoded on the Salmonella virulence plasmid controls the replication of a cohabitating antibiotic resistance plasmid, suggesting cross-regulation of plasmids on the RNA level.

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