• C-Type Lectin Receptor (CLR)-Fc Fusion Proteins As Tools to Screen for Novel CLR/Bacteria Interactions: An Exemplary Study on Preselected Isolates.

      Mayer, Sabine; Moeller, Rebecca; Monteiro, João T; Ellrott, Kerstin; Josenhans, Christine; Lepenies, Bernd; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (2018-01-01)
      C-type lectin receptors (CLRs) are carbohydrate-binding receptors that recognize their ligands often in a Ca2+-dependent manner. Upon ligand binding, myeloid CLRs in innate immunity trigger or inhibit a variety of signaling pathways, thus initiating or modulating effector functions such as cytokine production, phagocytosis, and antigen presentation. CLRs bind to various pathogens, including viruses, fungi, parasites, and bacteria. The bacterium Campylobacter jejuni (C. jejuni) is a very frequent Gram-negative zoonotic pathogen of humans, causing severe intestinal symptoms. Interestingly, C. jejuni expresses several glycosylated surface structures, for example, the capsular polysaccharide (CPS), lipooligosaccharide (LOS), and envelope proteins. This “Methods” paper describes applications of CLR–Fc fusion proteins to screen for yet unknown CLR/bacteria interactions using C. jejuni as an example. ELISA-based detection of CLR/bacteria interactions allows a frst prescreening that is further confrmed by flow cytometry-based binding analysis and visualized using confocal microscopy. By applying these methods, we identifed Dectin-1 as a novel CLR recognizing two selected C. jejuni isolates with different LOS and CPS genotypes. In conclusion, the heredescribed applications of CLR–Fc fusion proteins represent useful methods to screen for and identify novel CLR/bacteria interactions.
    • C-X-C Motif Chemokine Receptor 4 Blockade Promotes Tissue Repair After Myocardial Infarction by Enhancing Regulatory T Cell Mobilization and Immune-Regulatory Function.

      Wang, Yong; Dembowsky, Klaus; Chevalier, Eric; Stüve, Philipp; Korf-Klingebiel, Mortimer; Lochner, Matthias; Napp, L Christian; Frank, Heike; Brinkmann, Eva; Kanwischer, Anna; et al. (Lippinscott, Williams & Wilkins; American Heart Association, 2019-01-30)
      Acute myocardial infarction (MI) elicits an inflammatory response that drives tissue repair and adverse cardiac remodeling. Inflammatory cell trafficking after MI is controlled by C X-C motif chemokine ligand 12 (CXCL12) and its receptor, C-X-C motif chemokine receptor 4 (CXCR4). CXCR4 antagonists mobilize inflammatory cells and promote infarct repair, but the cellular mechanisms are unclear. We investigated the therapeutic potential and mode of action of the peptidic macrocycle CXCR4 antagonist POL5551 in mice with reperfused MI. We applied cell depletion and adoptive transfer strategies using lymphocyte-deficient Rag1 knockout mice; DEREG mice, which express a diphtheria toxin receptor-enhanced green fluorescent protein fusion protein under the control of the promoter/enhancer region of the regulatory T (T Intraperitoneal POL5551 injections in wild-type mice (8 mg/kg at 2, 4, 6, and 8 d) enhanced angiogenesis in the infarct border-zone, reduced scar size, and attenuated left ventricular remodeling and contractile dysfunction at 28 d. Treatment effects were absent in splenectomized wild-type mice, Rag1 knockout mice, and T Our data confirm CXCR4 blockade as a promising treatment strategy after MI. We identify dendritic cell-primed splenic T
    • Cell therapy products: focus on issues with manufacturing and quality control of chimeric antigen receptor T-cell therapies

      Eyles, Jim E; Vessillier, Sandrine; Jones, Anika; Stacey, Glyn; Schneider, Christian K; Price, Jack; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany.
      Recent accelerated approvals of Chimeric Antigen Receptor T‐cell (CAR‐T) therapies targeting refractory haematological malignancies underscore the potential for this novel technology platform to provide new therapeutic options for oncology areas with high unmet medical needs. However, these powerful ‘living drugs’ are markedly different to conventional small molecule and biologic therapies on several levels. The highly complex nature and varied composition of CAR‐T based products still requires considerable investigation to resolve the best approaches to ensure reproducible and cost‐effective manufacture, clinical development, and application. This review will focus on key issues for manufacturing and quality control of these exciting new therapeutic modalities, preceded by a brief description of CAR principals and clinical development considerations. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
    • Cell therapy products: focus on issues with manufacturing and quality control of chimeric antigen receptor T-cell therapies

      Eyles, Jim E; Vessillier, Sandrine; Jones, Anika; Stacey, Glyn; Schneider, Christian K; Price, Jack; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (2018-12-17)
    • Cholesterol sensing by CD81 is important for hepatitis C virus entry.

      Palor, Machaela; Stejskal, Lenka; Mandal, Piya; Lenman, Annasara; Alberione, Maria Pia; Kirui, Jared; Moeller, Rebecca; Ebner, Stefan; Meissner, Felix; Gerold, Gisa; et al. (DeGruyter, 2020-09-08)
      CD81 plays a role in a variety of physiological and pathological processes. Recent structural analysis of CD81 indicates that it contains an intramembrane cholesterol-binding pocket and that interaction with cholesterol may regulate a conformational switch in the extracellular domain of CD81. Therefore, CD81 possesses a potential cholesterol sensing mechanism; however, its relevance for protein function is thus far unknown. In this study we investigate CD81 cholesterol sensing in the context of its activity as a receptor for hepatitis C virus. Structure-led mutagenesis of the cholesterol-binding pocket reduced CD81-cholesterol association, but had disparate effects on HCV, both reducing and enhancing CD81 receptor activity. We reasoned that this could be explained by alterations in the consequences of cholesterol binding. To investigate this further we performed molecular dynamic simulations of CD81 with and without cholesterol; this identified an allosteric mechanism by which cholesterol binding regulates the conformation of CD81. To test this, we designed further mutations to force CD81 into either the open (cholesterol unbound) or closed (cholesterol bound) conformation. The open mutant of CD81 exhibited reduced receptor activity whereas the closed mutant was enhanced. These data are consistent with cholesterol switching CD81 between a receptor active and inactive state. CD81 interactome analysis also suggests that conformational switching may modulate the assembly of CD81-partner networks. This work furthers our understanding of the molecular mechanism of CD81 cholesterol sensing, how this relates to HCV entry and CD81's function as a molecular scaffold; these insights are relevant to CD81's varied roles in health and disease.
    • Clarithromycin impairs tissue-resident memory and Th17 responses to macrolide-resistant Streptococcus pneumoniae infections.

      Lindenberg, Marc; Almeida, Luis; Dhillon-LaBrooy, Ayesha; Siegel, Ekkehard; Henriques-Normark, Birgitta; Sparwasser, Tim; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Springer, 2021-02-17)
      The increasing prevalence of antimicrobial resistance in pathogens is a growing public health concern, with the potential to compromise the success of infectious disease treatments in the future. Particularly, the number of infections by macrolide antibiotics-resistant Streptococcus pneumoniae is increasing. We show here that Clarithromycin impairs both the frequencies and number of interleukin (IL)-17 producing T helper (Th) 17 cells within the lungs of mice infected with a macrolide-resistant S. pneumoniae serotype 15A strain. Subsequently, the tissue-resident memory CD4+ T cell (Trm) response to a consecutive S. pneumoniae infection was impaired. The number of lung resident IL-17+ CD69+ Trm was diminished upon Clarithromycin treatment during reinfection. Mechanistically, Clarithromycin attenuated phosphorylation of the p90-S6-kinase as part of the ERK pathway in Th17 cells. Moreover, a strong increase in the mitochondrial-mediated maximal respiratory capacity was observed, while mitochondrial protein translation and mTOR sisgnaling were unimpaired. Therefore, treatment with macrolide antibiotics may favor the spread of antimicrobial-resistant pathogens not only by applying a selection pressure but also by decreasing the natural T cell immune response. Clinical administration of macrolide antibiotics as standard therapy procedure during initial hospitalization should be reconsidered accordingly and possibly be withheld until microbial resistance is determined. KEY MESSAGES: • Macrolide-resistant S. pneumoniae infection undergoes immunomodulation by Clarithromycin • Clarithromycin treatment hinders Th17 and tissue-resident memory responses • Macrolide antibiotics impair Th17 differentiation in vitro by ERK-pathway inhibition.
    • A combined in silico and in vitro study on mouse Serpina1a antitrypsin-deficiency mutants.

      Eggenschwiler, Reto; Patronov, Atanas; Hegermann, Jan; Fráguas-Eggenschwiler, Mariane; Wu, Guangming; Cortnumme, Leon; Ochs, Matthias; Antes, Iris; Cantz, Tobias; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Springer-Nature, 2019-05-16)
      Certain point-mutations in the human SERPINA1-gene can cause severe α1-antitrypsin-deficiency (A1AT-D). Affected individuals can suffer from loss-of-function lung-disease and from gain-of-function liver-disease phenotypes. However, age of onset and severity of clinical appearance is heterogeneous amongst carriers, suggesting involvement of additional genetic and environmental factors. The generation of authentic A1AT-D mouse-models has been hampered by the complexity of the mouse Serpina1-gene locus and a model with concurrent lung and liver-disease is still missing. Here, we investigate point-mutations in the mouse Serpina1a antitrypsin-orthologue, which are homolog-equivalent to ones known to cause severe A1AT-D in human. We combine in silico and in vitro methods and we find that analyzed mutations do introduce potential disease-causing properties into Serpina1a. Finally, we show that introduction of the King’s-mutation causes inactivation of neutrophil elastase inhibitory-function in both, mouse and human antitrypsin, while the mouse Z-mutant retains activity. This work paves the path to generation of better A1AT-D mouse-models.
    • Commonly setting biological standards in rare diseases

      O’Connor, Daniel J.; Buckland, Jenny; Almond, Neil; Boyle, Jennifer; Coxon, Carmen; Gaki, Eleni; Martin, Javier; Mattiuzzo, Giada; Metcalfe, Clive; Page, Mark; et al. (Taylor& Francis, 2019-01-01)
      Introduction: Standardization is important across the life cycle of medicinal products, supporting the diagnosis, treatment, and prevention of a wide range of diseases. For rare diseases, standardization is even more important, as patient groups are small, presenting significant challenges in the design, conduct, analysis, and interpretation of clinical studies. It is here that standardization institutions, including the UK’s National Institute for Biological Standards and Control (NIBSC), can have a key role. Areas covered: A considerable proportion of NIBSC’s work supports the better understanding, diagnosis, treatment, and prevention of rare diseases. NIBSC is also part of the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), creating an agency that is uniquely placed to combine scientific and regulatory expertize for the benefit of public health. This review provides an overview of NIBSC’s work in rare diseases and highlights the positive impact of the work of standardization institutions in this field. Expert opinion: Standardization in product development is key for patients with rare diseases. The work of standardization institutions is increasingly being recognized as crucial for supporting scientific and clinical advancements, and early and collaborative interactions can provide drug developers with the necessary expertize, when standards matter most.
    • Conservation of the HBV RNA element epsilon in nackednaviruses reveals ancient origin of protein-primed reverse transcription.

      Beck, Jürgen; Seitz, Stefan; Lauber, Chris; Nassal, Michael; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Academy of Sciences, 2021-03-30)
      Hepadnaviruses, with the human hepatitis B virus as prototype, are small, enveloped hepatotropic DNA viruses which replicate by reverse transcription of an RNA intermediate. Replication is initiated by a unique protein-priming mechanism whereby a hydroxy amino acid side chain of the terminal protein (TP) domain of the viral polymerase (P) is extended into a short DNA oligonucleotide, which subsequently serves as primer for first-strand synthesis. A key component in the priming of reverse transcription is the viral RNA element epsilon, which contains the replication origin and serves as a template for DNA primer synthesis. Here, we show that recently discovered non-enveloped fish viruses, termed nackednaviruses [C. Lauber et al., Cell Host Microbe 22, 387-399 (2017)], employ a fundamentally similar replication mechanism despite their huge phylogenetic distance and major differences in genome organization and viral lifestyle. In vitro cross-priming studies revealed that few strategic nucleotide substitutions in epsilon enable site-specific protein priming by heterologous P proteins, demonstrating that epsilon is functionally conserved since the two virus families diverged more than 400 Mya. In addition, other cis elements crucial for the hepadnavirus-typical replication of pregenomic RNA into relaxed circular double-stranded DNA were identified at conserved positions in the nackednavirus genomes. Hence, the replication mode of both hepadnaviruses and nackednaviruses was already established in their Paleozoic common ancestor, making it a truly ancient and evolutionary robust principle of genome replication that is more widespread than previously thought.
    • Direct recognition of hepatocyte-expressed MHC class I alloantigens is required for tolerance induction.

      Paul-Heng, Moumita; Leong, Mario; Cunningham, Eithne; Bunker, Daniel L J; Bremner, Katherine; Wang, Zane; Wang, Chuanmin; Tay, Szun Szun; McGuffog, Claire; Logan, Grant J; et al. (NLM (Medline), 2018-08-09)
      Adeno-associated viral vector–mediated (AAV-mediated) expression of allogeneic major histocompatibility complex class I (MHC class I) in recipient liver induces donor-specific tolerance in mouse skin transplant models in which a class I allele (H-2Kb or H-2Kd) is mismatched between donor and recipient. Tolerance can be induced in mice primed by prior rejection of a donor-strain skin graft, as well as in naive recipients. Allogeneic MHC class I may be recognized by recipient T cells as an intact molecule (direct recognition) or may be processed and presented as an allogeneic peptide in the context of self-MHC (indirect recognition). The relative contributions of direct and indirect allorecognition to tolerance induction in this setting are unknown. Using hepatocyte-specific AAV vectors encoding WT allogeneic MHC class I molecules, or class I molecules containing a point mutation (D227K) that impedes direct recognition of intact allogeneic MHC class I by CD8+ T cells without hampering the presentation of processed peptides derived from allogeneic MHC class I, we show here that tolerance induction depends upon recognition of intact MHC class I. Indirect recognition alone yielded a modest prolongation of subsequent skin graft survival, attributable to the generation of CD4+ Tregs, but it was not sufficient to induce tolerance.
    • The Dynamics of Interleukin-10-Afforded Protection during Dextran Sulfate Sodium-Induced Colitis.

      Cardoso, Ana; Gil Castro, Antonio; Martins, Ana Catarina; Carriche, Guilhermina M; Murigneux, Valentine; Castro, Isabel; Cumano, Ana; Vieira, Paulo; Saraiva, Margarida; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Frontiers, 2018-03-01)
      Inflammatory bowel disease encompasses a group of chronic-inflammatory conditions of the colon and small intestine. These conditions are characterized by exacerbated inflammation of the organ that greatly affects the quality of life of patients. Molecular mechanisms counteracting this hyperinflammatory status of the gut offer strategies for therapeutic intervention. Among these regulatory molecules is the anti-inflammatory cytokine interleukin (IL)-10, as shown in mice and humans. Indeed, IL-10 signaling, particularly in macrophages, is essential for intestinal homeostasis. We sought to investigate the temporal profile of IL-10-mediated protection during chemical colitis and which were the underlying mechanisms. Using a novel mouse model of inducible IL-10 overexpression (pMT-10), described here, we show that mice preconditioned with IL-10 for 8 days before dextran sulfate sodium (DSS) administration developed a milder colitic phenotype. In IL-10-induced colitic mice, Ly6C cells isolated from the lamina propria showed a decreased inflammatory profile. Because our mouse model leads to transcription of the IL-10 transgene in the bone marrow and elevated seric IL-10 concentration, we investigated whether IL-10 could imprint immune cells in a long-lasting way, thus conferring sustained protection to colitis. We show that this was not the case, as IL-10-afforded protection was only observed if IL-10 induction immediately preceded DSS-mediated colitis. Thus, despite the protection afforded by IL-10 in colitis, novel strategies are required, specifically to achieve long-lasting protection.
    • Efficient oral vaccination by bioengineering virus-like particles with protozoan surface proteins.

      Serradell, Marianela C; Rupil, Lucía L; Martino, Román A; Prucca, César G; Carranza, Pedro G; Saura, Alicia; Fernández, Elmer A; Gargantini, Pablo R; Tenaglia, Albano H; Petiti, Juan P; et al. (Springer-Nature, 2019-01-21)
      Intestinal and free-living protozoa, such as Giardia lamblia, express a dense coat of variant-specific surface proteins (VSPs) on trophozoites that protects the parasite inside the host's intestine. Here we show that VSPs not only are resistant to proteolytic digestion and extreme pH and temperatures but also stimulate host innate immune responses in a TLR-4 dependent manner. We show that these properties can be exploited to both protect and adjuvant vaccine antigens for oral administration. Chimeric Virus-like Particles (VLPs) decorated with VSPs and expressing model surface antigens, such as influenza virus hemagglutinin (HA) and neuraminidase (NA), are protected from degradation and activate antigen presenting cells in vitro. Orally administered VSP-pseudotyped VLPs, but not plain VLPs, generate robust immune responses that protect mice from influenza infection and HA-expressing tumors. This versatile vaccine platform has the attributes to meet the ultimate challenge of generating safe, stable and efficient oral vaccines.
    • Establishment of porcine and human expanded potential stem cells.

      Gao, Xuefei; Nowak-Imialek, Monika; Chen, Xi; Chen, Dongsheng; Herrmann, Doris; Ruan, Degong; Chen, Andy Chun Hang; Eckersley-Maslin, Melanie A; Ahmad, Shakil; Lee, Yin Lau; et al. (Nature publishing group(NPG), 2019-06-03)
      We recently derived mouse expanded potential stem cells (EPSCs) from individual blastomeres by inhibiting the critical molecular pathways that predispose their differentiation. EPSCs had enriched molecular signatures of blastomeres and possessed developmental potency for all embryonic and extra-embryonic cell lineages. Here, we report the derivation of porcine EPSCs, which express key pluripotency genes, are genetically stable, permit genome editing, differentiate to derivatives of the three germ layers in chimeras and produce primordial germ cell-like cells in vitro. Under similar conditions, human embryonic stem cells and induced pluripotent stem cells can be converted, or somatic cells directly reprogrammed, to EPSCs that display the molecular and functional attributes reminiscent of porcine EPSCs. Importantly, trophoblast stem-cell-like cells can be generated from both human and porcine EPSCs. Our pathway-inhibition paradigm thus opens an avenue for generating mammalian pluripotent stem cells, and EPSCs present a unique cellular platform for translational research in biotechnology and regenerative medicine.
    • Ex Vivo/In vivo Gene Editing in Hepatocytes Using "All-in-One" CRISPR-Adeno-Associated Virus Vectors with a Self-Linearizing Repair Template.

      Krooss, Simon Alexander; Dai, Zhen; Schmidt, Florian; Rovai, Alice; Fakhiri, Julia; Dhingra, Akshay; Yuan, Qinggong; Yang, Taihua; Balakrishnan, Asha; Steinbrück, Lars; et al. (Cell Press/Elsevier, 2020-01-24)
      Adeno-associated virus (AAV)-based vectors are considered efficient and safe gene delivery systems in gene therapy. We combined two guide RNA genes, Cas9, and a self-linearizing repair template in one vector (AIO-SL) to correct fumarylacetoacetate hydrolase (FAH) deficiency in mice. The vector genome of 5.73 kb was packaged into VP2-depleted AAV particles (AAV2/8ΔVP2), which, however, did not improve cargo capacity. Reprogrammed hepatocytes were treated with AIO-SL.AAV2ΔVP2 and subsequently transplanted, resulting in large clusters of FAH-positive hepatocytes. Direct injection of AIO-SL.AAV8ΔVP2 likewise led to FAH expression and long-term survival. The AIO-SL vector achieved an ∼6-fold higher degree of template integration than vectors without template self-linearization. Subsequent analysis revealed that AAV8 particles, in contrast to AAV2, incorporate oversized genomes distinctly greater than 5.2 kb. Finally, our AAV8-based vector represents a promising tool for gene editing strategies to correct monogenic liver diseases requiring (large) fragment removal and/or simultaneous sequence replacement.
    • Groundwater, soil and compost, as possible sources of virulent and antibiotic-resistant Pseudomonas aeruginosa.

      Kaszab, Edit; Radó, Júlia; Kriszt, Balázs; Pászti, Judit; Lesinszki, Virág; Szabó, Ádám; Tóth, Gergő; Khaledi, Ariane; Szoboszlay, Sándor; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Taylor & Francis, 2019-11-18)
      Pseudomonas aeruginosa is a major public health concern all around the world. In the frame of this work, a set of diverse environmental P. aeruginosa isolates with various antibiotic resistance profiles were examined in a Galleria mellonella virulence model. Motility, serotypes, virulence factors and biofilm-forming ability were also examined. Molecular types were determined by pulsed-field gel electrophoresis (PFGE). Based on our results, the majority of environmental isolates were virulent in the G. mellonella test and twitching showed a positive correlation with mortality. Resistance against several antibiotic agents such as Imipenem correlated with a lower virulence in the applied G. mellonella model. PFGE revealed that five examined environmental isolates were closely related to clinically detected pulsed-field types. Our study demonstrated that industrial wastewater effluents, composts, and hydrocarbon-contaminated sites should be considered as hot spots of high-risk clones of P. aeruginosa.
    • HBV evolution and genetic variability: Impact on prevention, treatment and development of antivirals.

      Glebe, Dieter; Goldmann, Nora; Lauber, Chris; Seitz, Stefan; TWINCORE, Zentrum für experimentelle und klinische Infektionsforschung GmbH,Feodor-Lynen Str. 7, 30625 Hannover, Germany. (Elsevier, 2020-11-06)
      Hepatitis B virus (HBV) poses a major global health burden with 260 million people being chronically infected and 890,000 dying annually from complications in the course of the infection. HBV is a small enveloped virus with a reverse-transcribed DNA genome that infects hepatocytes and can cause acute and chronic infections of the liver. HBV is endemic in humans and apes representing the prototype member of the viral family Hepadnaviridae and can be divided into 10 genotypes. Hepadnaviruses have been found in all vertebrate classes and constitute an ancient viral family that descended from non-enveloped progenitors more than 360 million years ago. The de novo emergence of the envelope protein gene was accompanied with the liver-tropism and resulted in a tight virus-host association. The oldest HBV genomes so far have been isolated from human remains of the Bronze Age and the Neolithic (~7000 years before present). Despite the remarkable stability of the hepadnaviral genome over geological eras, HBV is able to rapidly evolve within an infected individual under pressure of the immune response or during antiviral treatment. Treatment with currently available antivirals blocking intracellular replication of HBV allows controlling of high viremia and improving liver health during long-term therapy of patients with chronic hepatitis B (CHB), but they are not sufficient to cure the disease. New therapy options that cover all HBV genotypes and emerging viral variants will have to be developed soon. In addition to the antiviral treatment of chronically infected patients, continued efforts to expand the global coverage of the currently available HBV vaccine will be one of the key factors for controlling the rising global spread of HBV. Certain improvements of the vaccine (e.g. inclusion of PreS domains) could counteract known problems such as low or no responsiveness of certain risk groups and waning anti-HBs titers leading to occult infections, especially with HBV genotypes E or F. But even with an optimal vaccine and a cure for hepatitis B, global eradication of HBV would be difficult to achieve because of an existing viral reservoir in primates and bats carrying closely related hepadnaviruses with zoonotic potential.
    • Let-7c inhibits cholangiocarcinoma growth but promotes tumor cell invasion and growth at extrahepatic sites.

      Xie, Yu; Zhang, Hang; Guo, Xing-Jun; Feng, Ye-Chen; He, Rui-Zhi; Li, Xu; Yu, Shuo; Zhao, Yan; Shen, Ming; Zhu, Feng; et al. (Springer Nature, 2018-02-14)
      Cholangiocarcinoma (CCA) is a cancer type with high postoperative relapse rates and poor long-term survival largely due to tumor invasion, distant metastasis, and multidrug resistance. Deregulated microRNAs (miRNAs) are implicated in several cancer types including CCA. The specific roles of the miRNA let-7c in cholangiocarcinoma are not known and need to be further elucidated. In our translational study we show that microRNA let-7c expression was significantly downregulated in human cholangiocarcinoma tissues when compared to adjacent tissues of the same patient. Let-7c inhibited the tumorigenic properties of cholangiocarcinoma cells including their self-renewal capacity and sphere formation in vitro and subcutaneous cancer cell growth in vivo. Ectopic let-7c overexpression suppressed migration and invasion capacities of cholangiocarcinoma cell lines in vitro, however, promoted distant invasiveness in vivo. Furthermore, we found that let-7c regulated the aforementioned malignant biological properties, at least in part, through regulation of EZH2 protein expression and through the DVL3/β-catenin axis. The miRNA let-7c thus plays an important dual role in regulating tumorigenic and metastatic abilities of human cholangiocarcinoma through mechanisms involving EZH2 protein and the DVL3/β-catenin axis.
    • MicroRNA-342-3p is a potent tumour suppressor in hepatocellular carcinoma

      Komoll, Ronja Melinda; Hu, Qingluan; Olarewaju, Olaniyi; von Döhlen, Lena; Yuan, Qinggong; Xie, Yu; Tsay, Hsin Chieh; Daon, Joel; Qin, Renyi; Manns, Michael P.; et al. (2021-01-01)
      Background & aims: Hepatocellular carcinoma (HCC) is a cancer with multiple aetiologies and widespread prevalence. Largely refractory to current treatments, HCC is the fourth leading cause of cancer-related deaths worldwide. MicroRNAs (miRNAs) are important regulators in HCCs. We aimed to identify tumour suppressor miRNAs during tumour regression in a conditional c-MYC-driven mouse model (LT2/MYC) of HCC, and to evaluate their therapeutic potential for HCC treatment. Methods: We performed miRNA expression profiling of developed and regressing LT2/MYC tumours and in-depth in vitro gain- and loss-of-function analyses. The effect of adeno-associated virus (AAV) vector-mediated miR-342-3p treatment was evaluated in 3 HCC mouse models. Results: We identified miR-342-3p as a tumour suppressor miRNA in HCC, with increased expression in regressing tumours. Forced miR-342-3p expression in hepatoma cells showed significantly decreased cell proliferation, migration, and colony formation. In vivo administration of AAV-miR-342-3p led to significant attenuation of tumour development and increased overall survival. We identified monocarboxylic acid transporter 1 (MCT1) as a bona fide target of miR-342-3p in HCC. We show that the tumour suppressor role of miR-342-3p is executed partly by modulating the lactate transport function of MCT1. Importantly, we find miR-342-3p downregulated in tumours from patients with HCC compared with matched non-tumour tissues, inversely correlating with MCT1 expression. We observed similar findings in TCGA-LIHC data. Conclusions: In our study, we identified and validated miR-342-3p as a tumour suppressor miRNA in HCC. We demonstrated its therapeutic efficacy in significantly attenuating tumour development, and prolonging survival, in different HCC mouse models. Identification of miR-342-3p as an effective tumour suppressor opens a therapeutic avenue for miRNA-mediated attenuation of HCC development. Lay summary: Hepatocellular carcinoma (HCC), the most common type of liver cancer, affects diverse populations and has a global impact, being the fourth leading cause of cancer deaths worldwide. There are currently no systemic therapies for HCC that can significantly prolong long-term survival. Thus, novel effective treatment options are urgently required. To understand the molecular basis of tumour regression, we compared tumours and regressing liver tumours in mice. We show that a small non-coding miRNA, miR-342-3p, is a tumour suppressor in HCC. Expression of miR-342-3p is low in tumours and high in regressing tumours. When miR-342-3p is delivered to mouse livers with HCC, it can significantly slow down liver tumour development and improve survival. Our study highlights the promising therapeutic potential of miR-342-3p intervention in HCC.
    • MicroRNA-342-3p is a potent tumour suppressor in hepatocellular carcinoma.

      Komoll, Ronja-Melinda; Hu, Qingluan; Olarewaju, Olaniyi; von Döhlen, Lena; Yuan, Qinggong; Xie, Yu; Tsay, Hsin-Chieh; Daon, Joel; Qin, Renyi; Manns, Michael P; et al. (Elsevier, 2020-07-30)
      Background & aims: Hepatocellular carcinoma (HCC) is a cancer with multiple aetiologies and widespread prevalence. Largely refractory to current treatments, HCC is the fourth leading cause of cancer-related deaths worldwide. MicroRNAs (miRNAs) are important regulators in HCCs. We aimed to identify tumour suppressor miRNAs during tumour regression in a conditional c-MYC-driven mouse model (LT2/MYC) of HCC, and to evaluate their therapeutic potential for HCC treatment. Methods: We performed miRNA expression profiling of developed and regressing LT2/MYC tumours and in-depth in vitro gain- and loss-of-function analyses. The effect of adeno-associated virus (AAV) vector-mediated miR-342-3p treatment was evaluated in 3 HCC mouse models. Results: We identified miR-342-3p as a tumour suppressor miRNA in HCC, with increased expression in regressing tumours. Forced miR-342-3p expression in hepatoma cells showed significantly decreased cell proliferation, migration, and colony formation. In vivo administration of AAV-miR-342-3p led to significant attenuation of tumour development and increased overall survival. We identified monocarboxylic acid transporter 1 (MCT1) as a bona fide target of miR-342-3p in HCC. We show that the tumour suppressor role of miR-342-3p is executed partly by modulating the lactate transport function of MCT1. Importantly, we find miR-342-3p downregulated in tumours from patients with HCC compared with matched non-tumour tissues, inversely correlating with MCT1 expression. We observed similar findings in TCGA-LIHC data. Conclusions: In our study, we identified and validated miR-342-3p as a tumour suppressor miRNA in HCC. We demonstrated its therapeutic efficacy in significantly attenuating tumour development, and prolonging survival, in different HCC mouse models. Identification of miR-342-3p as an effective tumour suppressor opens a therapeutic avenue for miRNA-mediated attenuation of HCC development. Lay summary: Hepatocellular carcinoma (HCC), the most common type of liver cancer, affects diverse populations and has a global impact, being the fourth leading cause of cancer deaths worldwide. There are currently no systemic therapies for HCC that can significantly prolong long-term survival. Thus, novel effective treatment options are urgently required. To understand the molecular basis of tumour regression, we compared tumours and regressing liver tumours in mice. We show that a small non-coding miRNA, miR-342-3p, is a tumour suppressor in HCC. Expression of miR-342-3p is low in tumours and high in regressing tumours. When miR-342-3p is delivered to mouse livers with HCC, it can significantly slow down liver tumour development and improve survival. Our study highlights the promising therapeutic potential of miR-342-3p intervention in HCC.
    • NeutrobodyPlex-monitoring SARS-CoV-2 neutralizing immune responses using nanobodies.

      Wagner, Teresa R; Ostertag, Elena; Kaiser, Philipp D; Gramlich, Marius; Ruetalo, Natalia; Junker, Daniel; Haering, Julia; Traenkle, Bjoern; Becker, Matthias; Dulovic, Alex; et al. (EMBO Press, 2021-04-27)
      In light of the COVID-19 pandemic, there is an ongoing need for diagnostic tools to monitor the immune status of large patient cohorts and the effectiveness of vaccination campaigns. Here, we present 11 unique nanobodies (Nbs) specific for the SARS-CoV-2 spike receptor-binding domain (RBD), of which 8 Nbs potently inhibit the interaction of RBD with angiotensin-converting enzyme 2 (ACE2) as the major viral docking site. Following detailed epitope mapping and structural analysis, we select two inhibitory Nbs, one of which binds an epitope inside and one of which binds an epitope outside the RBD:ACE2 interface. Based on these, we generate a biparatopic nanobody (bipNb) with viral neutralization efficacy in the picomolar range. Using bipNb as a surrogate, we establish a competitive multiplex binding assay ("NeutrobodyPlex") for detailed analysis of the presence and performance of neutralizing RBD-binding antibodies in serum of convalescent or vaccinated patients. We demonstrate that NeutrobodyPlex enables high-throughput screening and detailed analysis of neutralizing immune responses in infected or vaccinated individuals, to monitor immune status or to guide vaccine design.