SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Gerold Gisa 1979 ) "

Sökning: WFRF:(Gerold Gisa 1979 )

  • Resultat 1-50 av 56
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Alberione, Maria Pia, et al. (författare)
  • Single-nucleotide variants in human CD81 influence hepatitis C virus infection of hepatoma cells
  • 2020
  • Ingår i: Medical Microbiology and Immmunology. - : Springer. - 0300-8584 .- 1432-1831. ; 209:4, s. 499-514
  • Tidskriftsartikel (refereegranskat)abstract
    • An estimated number of 71 million people are living with chronic hepatitis C virus (HCV) infection worldwide and 400,000 annual deaths are related to the infection. HCV entry into the hepatocytes is complex and involves several host factors. The tetraspanin human CD81 (hCD81) is one of the four essential entry factors and is composed of one large extracellular loop, one small extracellular loop, four transmembrane domains, one intracellular loop and two intracellular tails. The large extracellular loop interacts with the E2 glycoprotein of HCV. Regions outside the large extracellular loop (backbone) of hCD81 have a critical role in post-binding entry steps and determine susceptibility of hepatocytes to HCV. Here, we investigated the effect of five non-synonymous single-nucleotide variants in the backbone of hCD81 on HCV susceptibility. We generated cell lines that stably express the hCD81 variants and infected the cells using HCV pseudoparticles and cell culture-derived HCV. Our results show that all the tested hCD81 variants support HCV pseudoparticle entry with similar efficiency as wild-type hCD81. In contrast, variants A54V, V211M and M220I are less supportive to cell culture-derived HCV infection. This altered susceptibility is HCV genotype dependent and specifically affected the cell entry step. Our findings identify three hCD81 genetic variants that are impaired in their function as HCV host factors for specific viral genotypes. This study provides additional evidence that genetic host variation contributes to inter-individual differences in HCV infection and outcome.
  •  
2.
  • Banse, Pia, et al. (författare)
  • CD81 receptor regions outside the large extracellular loop determine hepatitis C virus entry into hepatoma cells
  • 2018
  • Ingår i: Viruses. - : MDPI AG. - 1999-4915. ; 10:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) enters human hepatocytes using four essential entry factors, one of which is human CD81 (hCD81). The tetraspanin hCD81 contains a large extracellular loop (LEL), which interacts with the E2 glycoprotein of HCV. The role of the non-LEL regions of hCD81 (intracellular tails, four transmembrane domains, small extracellular loop and intracellular loop) is poorly understood. Here, we studied the contribution of these domains to HCV susceptibility of hepatoma cells by generating chimeras of related tetraspanins with the hCD81 LEL. Our results show that non-LEL regions in addition to the LEL determine susceptibility of cells to HCV. While closely related tetraspanins (X. tropicalis CD81 and D. rerio CD81) functionally complement hCD81 non-LEL regions, distantly related tetraspanins (C. elegans TSP9 amd D. melanogaster TSP96F) do not and tetraspanins with intermediate homology (hCD9) show an intermediate phenotype. Tetraspanin homology and susceptibility to HCV correlate positively. For some chimeras, infectivity correlates with surface expression. In contrast, the hCD9 chimera is fully surface expressed, binds HCV E2 glycoprotein but is impaired in HCV receptor function. We demonstrate that a cholesterol-coordinating glutamate residue in CD81, which hCD9 lacks, promotes HCV infection. This work highlights the hCD81 non-LEL regions as additional HCV susceptibility-determining factors.
  •  
3.
  • Becker, Miriam, et al. (författare)
  • Efficient clathrin-mediated entry of enteric adenoviruses in human duodenal cells
  • 2023
  • Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 97:10
  • Tidskriftsartikel (refereegranskat)abstract
    • Enteric adenovirus types F40 and 41 (EAdVs) are a leading cause of diarrhea and diarrhea-associated death in young children and have recently been proposed to cause acute hepatitis in children. EAdVs have a unique capsid architecture and exhibit — unlike other human adenoviruses — a relatively strict tropism for gastrointestinal tissues with, to date, understudied infection mechanism and unknown target cells. In this study, we turn to potentially limiting host factors by comparing EAdV entry in cell lines with respiratory and intestinal origin by cellular perturbation, virus particle tracking, and transmission electron microscopy. Our analyses highlight kinetic advantages for EAdVs in duodenal HuTu80 cell infection and reveal a larger fraction of mobile particles, faster virus uptake, and infectious particle entry in intestinal cells. Moreover, EAdVs display a dependence on clathrin- and dynamin-dependent pathways in intestinal cells. Detailed knowledge of virus entry routes and host factor requirements is essential to understanding pathogenesis and developing new countermeasures. Hence, this study provides novel insights into the entry mechanisms of a medically important virus with emerging tropism in a cell line originating from a relevant tissue. IMPORTANCE Enteric adenoviruses have historically been difficult to grow in cell culture, which has resulted in lack of knowledge of host factors and pathways required for infection of these medically relevant viruses. Previous studies in non-intestinal cell lines showed slow infection kinetics and generated comparatively low virus yields compared to other adenovirus types. We suggest duodenum-derived HuTu80 cells as a superior cell line for studies to complement efforts using complex intestinal tissue models. We show that viral host cell factors required for virus entry differ between cell lines from distinct origins and demonstrate the importance of clathrin-mediated endocytosis.
  •  
4.
  • Bley, Hanna, et al. (författare)
  • Proximity labeling of host factor ANXA3 in HCV infection reveals a novel LARP1 function in viral entry
  • 2024
  • Ingår i: Journal of Biological Chemistry. - : Elsevier. - 0021-9258 .- 1083-351X. ; 300:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) infection is tightly connected to the lipid metabolism with lipid droplets (LDs) serving as assembly sites for progeny virions. A previous LD proteome analysis identified annexin A3 (ANXA3) as an important HCV host factor that is enriched at LDs in infected cells and required for HCV morphogenesis. To further characterize ANXA3 function in HCV, we performed proximity labeling using ANXA3-BioID2 as bait in HCV-infected cells. Two of the top proteins identified proximal to ANXA3 during HCV infection were the La-related protein 1 (LARP1) and the ADP ribosylation factor-like protein 8B (ARL8B), both of which have been previously described to act in HCV particle production. In follow-up experiments, ARL8B functioned as a pro-viral HCV host factor without localizing to LDs and thus likely independent of ANXA3. In contrast, LARP1 interacts with HCV core protein in an RNA-dependent manner and is translocated to LDs by core protein. Knockdown of LARP1 decreased HCV spreading without altering HCV RNA replication or viral titers. Unexpectedly, entry of HCV particles and E1/E2-pseudotyped lentiviral particles was reduced by LARP1 depletion, whereas particle production was not altered. Using a recombinant vesicular stomatitis virus (VSV)ΔG entry assay, we showed that LARP1 depletion also decreased entry of VSV with VSV, MERS, and CHIKV glycoproteins. Therefore, our data expand the role of LARP1 as an HCV host factor that is most prominently involved in the early steps of infection, likely contributing to endocytosis of viral particles through the pleiotropic effect LARP1 has on the cellular translatome.
  •  
5.
  • Brown, Richard J. P., et al. (författare)
  • Liver-expressed Cd302 and Cr1l limit hepatitis C virus cross-species transmission to mice
  • 2020
  • Ingår i: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 6:45
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) has no animal reservoir, infecting only humans. To investigate species barrier determinants limiting infection of rodents, murine liver complementary DNA library screening was performed, identifying transmembrane proteins Cd302 and Cr1l as potent restrictors of HCV propagation. Combined ectopic expression in human hepatoma cells impeded HCV uptake and cooperatively mediated transcriptional dysregulation of a noncanonical program of immunity genes. Murine hepatocyte expression of both factors was constitutive and not interferon inducible, while differences in liver expression and the ability to restrict HCV were observed between the murine orthologs and their human counterparts. Genetic ablation of endogenous Cd302 expression in human HCV entry factor transgenic mice increased hepatocyte permissiveness for an adapted HCV strain and dysregulated expression of metabolic process and host defense genes. These findings highlight human-mouse differences in liver-intrinsic antiviral immunity and facilitate the development of next-generation murine models for preclinical testing of HCV vaccine candidates.
  •  
6.
  • Bruening, Janina, et al. (författare)
  • Hepatitis C virus enters liver cells using the CD81 receptor complex proteins calpain-5 and CBLB
  • 2018
  • Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 14:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) and the malaria parasite Plasmodium use the membrane protein CD81 to invade human liver cells. Here we mapped 33 host protein interactions of CD81 in primary human liver and hepatoma cells using high-resolution quantitative proteomics. In the CD81 protein network, we identified five proteins which are HCV entry factors or facilitators including epidermal growth factor receptor (EGFR). Notably, we discovered calpain-5 (CAPN5) and the ubiquitin ligase Casitas B-lineage lymphoma proto-oncogene B (CBLB) to form a complex with CD81 and support HCV entry. CAPN5 and CBLB were required for a post-binding and pre-replication step in the HCV life cycle. Knockout of CAPN5 and CBLB reduced susceptibility to all tested HCV genotypes, but not to other enveloped viruses such as vesicular stomatitis virus and human coronavirus. Furthermore, Plasmodium sporozoites relied on a distinct set of CD81 interaction partners for liver cell entry. Our findings reveal a comprehensive CD81 network in human liver cells and show that HCV and Plasmodium highjack selective CD81 interactions, including CAPN5 and CBLB for HCV, to invade cells.
  •  
7.
  • Bruening, Janina, et al. (författare)
  • The Role of Type III Interferons in Hepatitis C Virus Infection and Therapy
  • 2017
  • Ingår i: Journal of Immunology Research. - : Hindawi Publishing Corporation. - 2314-8861 .- 2314-7156.
  • Tidskriftsartikel (refereegranskat)abstract
    • The human interferon (IFN) response is a key innate immune mechanism to fight virus infection. IFNs are host-encoded secreted proteins, which induce IFN-stimulated genes (ISGs) with antiviral properties. Among the three classes of IFNs, type III IFNs, also called IFN lambdas (IFNLs), are an essential component of the innate immune response to hepatitis C virus (HCV). In particular, human polymorphisms in IFNL gene loci correlate with hepatitis C disease progression and with treatment response. To date, the underlying mechanisms remain mostly elusive; however it seems clear that viral infection of the liver induces IFNL responses. As IFNL receptors show a more restricted tissue expression than receptors for other classes of IFNs, IFNL treatment has reduced side effects compared to the classical type I IFN treatment. In HCV therapy, however, IFNL will likely not play an important role as highly effective direct acting antivirals (DAA) exist. Here, we will review our current knowledge on IFNL gene expression, protein properties, signaling, ISG induction, and its implications on HCV infection and treatment. Finally, we will discuss the lessons learnt from the HCV and IFNL field for virus infections beyond hepatitis C.
  •  
8.
  • Carriquí-Madroñal, Belén, et al. (författare)
  • Genetic and pharmacological perturbation of hepatitis-C virus entry
  • 2023
  • Ingår i: Current Opinion in Virology. - : Elsevier. - 1879-6257 .- 1879-6265. ; 62
  • Forskningsöversikt (refereegranskat)abstract
    • Hepatitis-C virus (HCV) chronically infects 58 million individuals worldwide with variable disease outcome. While a subfraction of individuals exposed to the virus clear the infection, the majority develop chronic infection if untreated. Another subfraction of chronically ill proceeds to severe liver disease. The underlying causes of this interindividual variability include genetic polymorphisms in interferon genes. Here, we review available data on the influence of genetic or pharmacological perturbation of HCV host dependency factors on the clinically observed interindividual differences in disease outcome. We focus on host factors mediating virus entry into human liver cells. We assess available data on genetic variants of the major entry factors scavenger receptor class-B type I, CD81, claudin-1, and occludin as well as pharmacological perturbation of these entry factors. We review cell culture experimental and clinical cohort study data and conclude that entry factor perturbation may contribute to disease outcome of hepatitis C.
  •  
9.
  • Carriquí-Madroñal, Belén, et al. (författare)
  • The matrix metalloproteinase ADAM10 supports hepatitis C virus entry and cell-to-cell spread via its sheddase activity
  • 2023
  • Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 19:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) exploits the four entry factors CD81, scavenger receptor class B type I (SR-BI, also known as SCARB1), occludin, and claudin-1 as well as the co-factor epidermal growth factor receptor (EGFR) to infect human hepatocytes. Here, we report that the disintegrin and matrix metalloproteinase 10 (ADAM10) associates with CD81, SR-BI, and EGFR and acts as HCV host factor. Pharmacological inhibition, siRNA-mediated silencing and genetic ablation of ADAM10 reduced HCV infection. ADAM10 was dispensable for HCV replication but supported HCV entry and cell-to-cell spread. Substrates of the ADAM10 sheddase including epidermal growth factor (EGF) and E-cadherin, which activate EGFR family members, rescued HCV infection of ADAM10 knockout cells. ADAM10 did not influence infection with other enveloped RNA viruses such as alphaviruses and a common cold coronavirus. Collectively, our study reveals a critical role for the sheddase ADAM10 as a HCV host factor, contributing to EGFR family member transactivation and as a consequence to HCV uptake.
  •  
10.
  • de Diego, J L, et al. (författare)
  • Sensing, presenting, and regulating PAMPs.
  • 2007
  • Ingår i: Ernst Schering Foundation symposium proceedings. ; :3, s. 83-95
  • Tidskriftsartikel (refereegranskat)abstract
    • Recognition of microbial infection and initiation of immune responses are controlled by multiple mechanisms. Toll-like receptors (TLRs) are key components of the innate immune system that detect microbial infection. TLR activation helps to eliminate the invading pathogens, coordinate systemic defenses, and initiate adaptive immune responses. Despite progress elucidating the TLR signaling aspects and the physiological relevance of TLRs in microbial infections, the molecular basis of microbial recognition by TLRs is still not fully understood. In this article we focus on the availability of microbial ligands to regulate presentation to TLRs and assist in our understanding of TLR-mediated microbial recognition.
  •  
11.
  • Dong, Thi Ngan, et al. (författare)
  • A multitask transfer learning framework for the prediction of virus-human protein–protein interactions
  • 2021
  • Ingår i: BMC Bioinformatics. - : BioMed Central. - 1471-2105. ; 22:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Viral infections are causing significant morbidity and mortality worldwide. Understanding the interaction patterns between a particular virus and human proteins plays a crucial role in unveiling the underlying mechanism of viral infection and pathogenesis. This could further help in prevention and treatment of virus-related diseases. However, the task of predicting protein–protein interactions between a new virus and human cells is extremely challenging due to scarce data on virus-human interactions and fast mutation rates of most viruses.Results: We developed a multitask transfer learning approach that exploits the information of around 24 million protein sequences and the interaction patterns from the human interactome to counter the problem of small training datasets. Instead of using hand-crafted protein features, we utilize statistically rich protein representations learned by a deep language modeling approach from a massive source of protein sequences. Additionally, we employ an additional objective which aims to maximize the probability of observing human protein–protein interactions. This additional task objective acts as a regularizer and also allows to incorporate domain knowledge to inform the virus-human protein–protein interaction prediction model.Conclusions: Our approach achieved competitive results on 13 benchmark datasets and the case study for the SARS-CoV-2 virus receptor. Experimental results show that our proposed model works effectively for both virus-human and bacteria-human protein–protein interaction prediction tasks. We share our code for reproducibility and future research at https://git.l3s.uni-hannover.de/dong/multitask-transfer.
  •  
12.
  • Fedeli, Chiara, et al. (författare)
  • Axl can serve as entry factor for lassa virus depending on the functional glycosylation of dystroglycan
  • 2018
  • Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 92:5
  • Tidskriftsartikel (refereegranskat)abstract
    • The highly pathogenic arenavirus Lassa virus (LASV) represents a serious public health problem in Africa. Although the principal LASV receptor, dystroglycan (DG), is ubiquitously expressed, virus binding critically depends on DG's posttranslational modification, which does not always correlate with tissue tropism. The broadly expressed phosphatidylserine receptor Axl was recently identified as an alternative LASV receptor candidate, but its role in LASV entry is unclear. Here, we investigate the exact role of Axl in LASV entry as a function of DG's posttranslational modification. We found that in the absence of functional DG, Axl can mediate LASV entry via apoptotic mimicry. Productive entry requires virus-induced receptor activation, involves macropinocytosis, and critically depends on LAMP-1. In endothelial cells that express low levels of glycosylated DG, both receptors can promote LASV entry. In sum, our study defines the roles of Axl in LASV entry and provides a rationale for targeting Axl in antiviral therapy.
  •  
13.
  •  
14.
  • Gerold, Gisa, 1979-, et al. (författare)
  • A Toll-like receptor 2-integrin beta3 complex senses bacterial lipopeptides via vitronectin.
  • 2008
  • Ingår i: Nature Immunology. - : Springer Science and Business Media LLC. - 1529-2908 .- 1529-2916. ; 9:7, s. 761-8
  • Tidskriftsartikel (refereegranskat)abstract
    • Toll-like receptor 2 (TLR2) initiates inflammation in response to bacterial lipopeptide (BLP). However, the molecular mechanisms enabling the detection of BLP by TLR2 are unknown. Here we investigated the interaction of BLP with human serum proteins and identified vitronectin as a BLP-recognition molecule. Vitronectin and its receptor, integrin beta(3), were required for BLP-induced TLR2-mediated activation of human monocytes. Furthermore, monocytes from patients with Glanzmann thrombasthenia, which lack integrin beta(3), were completely unresponsive to BLP. In addition, integrin beta(3) formed a complex with TLR2 and this complex dissociated after BLP stimulation. Notably, vitronectin and integrin beta(3) coordinated responses to other TLR2 agonists such as lipoteichoic acid and zymosan. Our findings show that vitronectin and integrin beta(3) contribute to the initiation of TLR2 responses.
  •  
15.
  • Gerold, Gisa, 1979-, et al. (författare)
  • Decoding protein networks during virus entry by quantitative proteomics
  • 2016
  • Ingår i: Virus Research. - : Elsevier. - 0168-1702 .- 1872-7492. ; 218, s. 25-39
  • Tidskriftsartikel (refereegranskat)abstract
    • Virus entry into host cells relies on interactions between viral and host structures including lipids, carbohydrates and proteins. Particularly, protein-protein interactions between viral surface proteins and host proteins as well as secondary host protein-protein interactions play a pivotal role in coordinating virus binding and uptake. These interactions are dynamic and frequently involve multiprotein complexes. In the past decade mass spectrometry based proteomics methods have reached sensitivities and high throughput compatibilities of genomics methods and now allow the reliable quantitation of proteins in complex samples from limited material. As proteomics provides essential information on the biologically active entity namely the protein, including its posttranslational modifications and its interactions with other proteins, it is an indispensable method in the virologist's toolbox. Here we review protein interactions during virus entry and compare classical biochemical methods to study entry with novel technically advanced quantitative proteomics techniques. We highlight the value of quantitative proteomics in mapping functional virus entry networks, discuss the benefits and limitations and illustrate how the methodology will help resolve unsettled questions in virus entry research in the future.
  •  
16.
  • Gerold, Gisa, 1979-, et al. (författare)
  • Hepatitis C Virus Entry : Protein Interactions and Fusion Determinants Governing Productive Hepatocyte Invasion
  • 2020
  • Ingår i: Cold Spring Harbor Perspectives in Medicine. - : Cold Spring Harbor Laboratory Press (CSHL). - 2157-1422. ; 10:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) entry is among the best-studied uptake processes for human pathogenic viruses. Uptake follows a spatially and temporally tightly controlled program. Numerous host factors including proteins, lipids, and glycans promote productive uptake of HCV particles into human liver cells. The virus initially attaches to surface proteoglycans, lipid receptors such as the scavenger receptor BI (SR-BI), and to the tetraspanin CD81. After lateral translocation of virions to tight junctions, claudin-1 (CLDN1) and occludin (OCLN) are essential for entry. Clathrin-mediated endocytosis engulfs HCV particles, which fuse with endosoma I membranes after pH drop. Uncoating of the viral RNA genome in the cytoplasm completes the entry process. Here we systematically review and classify HCV entry factors by their mechanistic role, relevance, and level of evidence. Finally, we report on more recent knowledge on determinants of membrane fusion and close with an outlook on future implications of HCV entry research.
  •  
17.
  • Gerold, Gisa, 1979-, et al. (författare)
  • Hepatitis C virus NS5B polymerase primes innate immune signaling
  • 2013
  • Ingår i: Hepatology. - Hoboken : Wiley-Blackwell. - 0270-9139 .- 1527-3350. ; 57:3, s. 1275-1277
  • Tidskriftsartikel (refereegranskat)abstract
    • Innate immunity controls pathogen replication and spread. Yet, certain pathogens, such as Hepatitis C Virus (HCV), escape immune elimination and establish persistent infections that promote chronic inflammation and related diseases. Whereas HCV regulatory proteins that attenuate antiviral responses are known, those that promote inflammation and liver injury remain to be identified. Here, we show that transient expression of HCV RNA-dependent RNA polymerase (RdRp), NS5B, in mouse liver and human hepatocytes results in production of small RNA species that activate innate immune signaling via TBK1-IRF3 and NF-kappa B and induce cytokine production, including type I interferons (IFN) and IL-6. NS5B-expression also results in liver damage.
  •  
18.
  • Gerold, Gisa, 1979-, et al. (författare)
  • Locking out hepatitis C
  • 2011
  • Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 17:5, s. 542-4
  • Tidskriftsartikel (refereegranskat)
  •  
19.
  •  
20.
  • Gerold, Gisa, 1979-, et al. (författare)
  • Quantitative Proteomics Identifies Serum Response Factor Binding Protein 1 as a Host Factor for Hepatitis C Virus Entry
  • 2015
  • Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 12:5, s. 864-878
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) enters human hepatocytes through a multistep mechanism involving, among other host proteins, the virus receptor CD81. How CD81 governs HCV entry is poorly characterized, and CD81 protein interactions after virus binding remain elusive. We have developed a quantitative proteomics protocol to identify HCV-triggered CD81 interactions and found 26 dynamic binding partners. At least six of these proteins promote HCV infection, as indicated by RNAi. We further characterized serum response factor binding protein 1 (SRFBP1), which is recruited to CD81 during HCV uptake and supports HCV infection in hepatoma cells and primary human hepatocytes. SRFBP1 facilitates host cell penetration by all seven HCV genotypes, but not of vesicular stomatitis virus and human coronavirus. Thus, SRFBP1 is an HCV-specific, pan-genotypic host entry factor. These results demonstrate the use of quantitative proteomics to elucidate pathogen entry and underscore the importance of host protein-protein interactions during HCV invasion.
  •  
21.
  • Gerold, Gisa, 1979-, et al. (författare)
  • Teaching new tricks to an old foe : murinizing hepatitis C virus
  • 2010
  • Ingår i: Hepatology. - : American Association for the Study of Liver Diseases. - 0270-9139 .- 1527-3350. ; 52:6, s. 2233-2236
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) naturally infects only humans and chimpanzees. The determinants responsible for this narrow species tropism are not well defined. Virus cell entry involves human scavenger receptor class B type I (SR‐BI), CD81, claudin‐1 and occludin. Among these, at least CD81 and occludin are utilized in a highly species‐specific fashion, thus contributing to the narrow host range of HCV. We adapted HCV to mouse CD81 and identified three envelope glycoprotein mutations which together enhance infection of cells with mouse or other rodent receptors approximately 100‐fold. These mutations enhanced interaction with human CD81 and increased exposure of the binding site for CD81 on the surface of virus particles. These changes were accompanied by augmented susceptibility of adapted HCV to neutralization by E2‐specific antibodies indicative of major conformational changes of virus‐resident E1/E2‐complexes. Neutralization with CD81, SR‐BI‐ and claudin‐1‐specific antibodies and knock down of occludin expression by siRNAs indicate that the adapted virus remains dependent on these host factors but apparently utilizes CD81, SR‐BI and occludin with increased efficiency. Importantly, adapted E1/E2 complexes mediate HCV cell entry into mouse cells in the absence of human entry factors. These results further our knowledge of HCV receptor interactions and indicate that three glycoprotein mutations are sufficient to overcome the species‐specific restriction of HCV cell entry into mouse cells. Moreover, these findings should contribute to the development of an immunocompetent small animal model fully permissive to HCV.
  •  
22.
  • Gerold, Gisa, 1979-, et al. (författare)
  • The HCV life cycle : in vitro tissue culture systems and therapeutic targets
  • 2014
  • Ingår i: Digestive Diseases. - : S. Karger. - 0257-2753 .- 1421-9875. ; 32:5, s. 525-537
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) is a highly variable plus-strand RNA virus of the family Flaviviridae. Viral strains are grouped into six epidemiologically relevant genotypes that differ from each other by more than 30% at the nucleotide level. The variability of HCV allows immune evasion and facilitates persistence. It is also a substantial challenge for the development of specific antiviral therapies effective across all HCV genotypes and for prevention of drug resistance. Novel HCV cell culture models were instrumental for identification and profiling of therapeutic strategies. Concurrently, these models revealed numerous host factors critical for HCV propagation, some of which have emerged as targets for antiviral therapy. It is generally assumed that the use of host factors is conserved among HCV isolates and genotypes. Additionally, the barrier to viral resistance is thought to be high when interfering with host factors. Therefore, current drug development includes both targeting of viral factors but also of host factors essential for virus replication. In fact, some of these host-targeting agents, for instance inhibitors of cyclophilin A, have advanced to late stage clinical trials. Here, we highlight currently available cell culture systems for HCV, review the most prominent host-targeting strategies against hepatitis C and critically discuss opportunities and risks associated with host-targeting antiviral strategies.
  •  
23.
  • Gerold, Gisa, 1979-, et al. (författare)
  • What is the role of Toll-like receptors in bacterial infections?
  • 2007
  • Ingår i: Seminars in Immunology. - : Elsevier BV. - 1044-5323 .- 1096-3618. ; 19:1, s. 41-7
  • Tidskriftsartikel (refereegranskat)abstract
    • Innate immunity relies on signalling by Toll-like receptors (TLRs) to alert the immune system of the presence of invading bacteria. TLR activation leads to the release of cytokines that allow for effective innate and adaptive immune responses. However, the contribution of different TLRs depends on the site of the infection and the pathogen. This review will describe the involvement of TLRs in the development of three different bacterial infections as well as our current understanding of the role of TLRs during microbial pathogenesis.
  •  
24.
  • Haid, Sibylle, et al. (författare)
  • Repurposing screen identifies novel candidates for broad-spectrum coronavirus antivirals and druggable host targets
  • 2024
  • Ingår i: Antimicrobial Agents and Chemotherapy. - : American Society for Microbiology. - 0066-4804 .- 1098-6596. ; 68:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Libraries composed of licensed drugs represent a vast repertoire of molecules modulating physiological processes in humans, providing unique opportunities for the discovery of host-targeting antivirals. We screened the Repurposing, Focused Rescue, and Accelerated Medchem (ReFRAME) repurposing library with approximately 12,000 molecules for broad-spectrum coronavirus antivirals and discovered 134 compounds inhibiting an alphacoronavirus and mapping to 58 molecular target categories. Dominant targets included the 5-hydroxytryptamine receptor, the dopamine receptor, and cyclin-dependent kinases. Gene knock-out of the drugs’ host targets including cathepsin B and L (CTSB/L; VBY-825), the aryl hydrocarbon receptor (AHR; Phortress), the farnesyl-diphosphate farnesyltransferase 1 (FDFT1; P-3622), and the kelch-like ECH-associated protein 1 (KEAP1; Omaveloxolone), significantly modulated HCoV-229E infection, providing evidence that these compounds inhibited the virus through acting on their respective host targets. Counter-screening of all 134 primary compound candidates with SARS-CoV-2 and validation in primary cells identified Phortress, an AHR activating ligand, P-3622-targeting FDFT1, and Omaveloxolone, which activates the NFE2-like bZIP transcription factor 2 (NFE2L2) by liberating it from its endogenous inhibitor KEAP1, as antiviral candidates for both an Alpha- and a Betacoronavirus. This study provides an overview of HCoV-229E repurposing candidates and reveals novel potentially druggable viral host dependency factors hijacked by diverse coronaviruses.
  •  
25.
  • Herrador, Antonio, et al. (författare)
  • Dynamic Dystroglycan Complexes Mediate Cell Entry of Lassa Virus
  • 2019
  • Ingår i: mBio. - : American Society for Microbiology. - 2161-2129 .- 2150-7511. ; 10:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Recognition of functional receptors by viruses is a key determinant for their host range, tissue tropism, and disease potential. The highly pathogenic Lassa virus (LASV) currently represents one of the most important emerging pathogens. The major cellular receptor for LASV in human cells is the ubiquitously expressed and evolutionary highly conserved extracellular matrix receptor dystroglycan (DG). In the host, DG interacts with many cellular proteins in a tissue-specific manner. The resulting distinct supramolecular complexes likely represent the functional units for viral entry, and preexisting protein-protein interactions may critically influence DG's function in productive viral entry. Using an unbiased shotgun proteomic approach, we define the largely unknown molecular composition of DG complexes present in highly susceptible epithelial cells that represent important targets for LASV during viral transmission. We further show that the specific composition of cellular DG complexes can affect DG's function in receptor-mediated endocytosis of the virus. Under steady-state conditions, epithelial DG complexes underwent rapid turnover via an endocytic pathway that shared some characteristics with DG-mediated LASV entry. However, compared to steady-state uptake of DG, LASV entry via DG occurred faster and critically depended on additional signaling by receptor tyrosine kinases and the downstream effector p21-activating kinase. In sum, we show that the specific molecular composition of DG complexes in susceptible cells is a determinant for productive virus entry and that the pathogen can manipulate the existing DG-linked endocytic pathway. This highlights another level of complexity of virus-receptor interaction and provides possible cellular targets for therapeutic antiviral intervention.Importance: Recognition of cellular receptors allows emerging viruses to break species barriers and is an important determinant for their disease potential. Many virus receptors have complex tissue-specific interactomes, and preexisting protein-protein interactions may influence their function. Combining shotgun proteomics with a biochemical approach, we characterize the molecular composition of the functional receptor complexes used by the highly pathogenic Lassa virus (LASV) to invade susceptible human cells. We show that the specific composition of the receptor complexes affects productive entry of the virus, providing proof-of-concept. In uninfected cells, these functional receptor complexes undergo dynamic turnover involving an endocytic pathway that shares some characteristics with viral entry. However, steady-state receptor uptake and virus endocytosis critically differ in kinetics and underlying signaling, indicating that the pathogen can manipulate the receptor complex according to its needs. Our study highlights a remarkable complexity of LASV-receptor interaction and identifies possible targets for therapeutic antiviral intervention.
  •  
26.
  • Kapoor, Amit, et al. (författare)
  • Characterization of a canine homolog of hepatitis C virus
  • 2011
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:28, s. 11608-11613
  • Tidskriftsartikel (refereegranskat)abstract
    • An estimated 3% of the world's population is chronically infected with hepatitis C virus (HCV). Although HCV was discovered more than 20 y ago, its origin remains obscure largely because no closely related animal virus homolog has been identified; furthermore, efforts to understand HCV pathogenesis have been hampered by the absence of animal models other than chimpanzees for human disease. Here we report the identification in domestic dogs of a nonprimate hepacivirus. Comparative phylogenetic analysis of the canine hepacivirus (CHV) confirmed it to be the most genetically similar animal virus homolog of HCV. Bayesian Markov chains Monte Carlo and associated time to most recent common ancestor analyses suggest a mean recent divergence time of CHV and HCV clades within the past 500-1,000 y, well after the domestication of canines. The discovery of CHV may provide new insights into the origin and evolution of HCV and a tractable model system with which to probe the pathogenesis, prevention, and treatment of diseases caused by hepacivirus infection.
  •  
27.
  • Kirui, Jared, et al. (författare)
  • The Phosphatidylserine Receptor TIM-1 Enhances Authentic Chikungunya Virus Cell Entry
  • 2021
  • Ingår i: Cells. - : MDPI. - 2073-4409. ; 10:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Chikungunya virus (CHIKV) is a re-emerging, mosquito-transmitted, enveloped positive stranded RNA virus. Chikungunya fever is characterized by acute and chronic debilitating arthritis. Although multiple host factors have been shown to enhance CHIKV infection, the molecular mechanisms of cell entry and entry factors remain poorly understood. The phosphatidylserine-dependent receptors, T-cell immunoglobulin and mucin domain 1 (TIM-1) and Axl receptor tyrosine kinase (Axl), are transmembrane proteins that can serve as entry factors for enveloped viruses. Previous studies used pseudoviruses to delineate the role of TIM-1 and Axl in CHIKV entry. Conversely, here, we use the authentic CHIKV and cells ectopically expressing TIM-1 or Axl and demonstrate a role for TIM-1 in CHIKV infection. To further characterize TIM-1-dependent CHIKV infection, we generated cells expressing domain mutants of TIM-1. We show that point mutations in the phosphatidylserine binding site of TIM-1 lead to reduced cell binding, entry, and infection of CHIKV. Ectopic expression of TIM-1 renders immortalized keratinocytes permissive to CHIKV, whereas silencing of endogenously expressed TIM-1 in human hepatoma cells reduces CHIKV infection. Altogether, our findings indicate that, unlike Axl, TIM-1 readily promotes the productive entry of authentic CHIKV into target cells.
  •  
28.
  • Krüger, Nadine, et al. (författare)
  • The upper respiratory tract of felids is highly susceptible to sars‐cov‐2 infection
  • 2021
  • Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 22:19
  • Tidskriftsartikel (refereegranskat)abstract
    • Natural or experimental infection of domestic cats and virus transmission from humans to captive predatory cats suggest that felids are highly susceptible to SARS‐CoV‐2 infection. However, it is unclear which cells and compartments of the respiratory tract are infected. To address this question, primary cell cultures derived from the nose, trachea, and lungs of cat and lion were inoculated with SARS‐CoV‐2. Strong viral replication was observed for nasal mucosa explants and tracheal air–liquid interface cultures, whereas replication in lung slices was less efficient. Infection was mainly restricted to epithelial cells and did not cause major pathological changes. Detection of high ACE2 levels in the nose and trachea but not lung further suggests that susceptibility of feline tissues to SARS‐CoV‐2 correlates with ACE2 expression. Collectively, this study demonstrates that SARS‐ CoV‐2 can efficiently replicate in the feline upper respiratory tract ex vivo and thus highlights the risk of SARS‐CoV‐2 spillover from humans to felids.
  •  
29.
  • Lasswitz, Lisa, et al. (författare)
  • Glycomics and Proteomics Approaches to Investigate Early Adenovirus-Host Cell Interactions
  • 2018
  • Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 430:13, s. 1863-1882
  • Tidskriftsartikel (refereegranskat)abstract
    • Adenoviruses as most viruses rely on glycan and protein interactions to attach to and enter susceptible host cells. The Adenoviridae family comprises more than 80 human types and they differ in their attachment factor and receptor usage, which likely contributes to the diverse tropism of the different types. In the past years, methods to systematically identify glycan and protein interactions have advanced. In particular sensitivity, speed and coverage of mass spectrometric analyses allow for high-throughput identification of glycans and peptides separated by liquid chromatography. Also, developments in glycan microarray technologies have led to targeted, high-throughput screening and identification of glycan-based receptors. The mapping of cell surface interactions of the diverse adenovirus types has implications for cell, tissue, and species tropism as well as drug development. Here we review known adenovirus interactions with glycan- and protein-based receptors, as well as glycomics and proteomics strategies to identify yet elusive virus receptors and attachment factors. We finally discuss challenges, bottlenecks, and future research directions in the field of non-enveloped virus entry into host cells.
  •  
30.
  • Lasswitz, Lisa, et al. (författare)
  • The tetraspanin CD81 is a host factor for Chikungunya virus replication
  • 2022
  • Ingår i: mBio. - : ASM International. - 2161-2129 .- 2150-7511. ; 13:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Chikungunya virus (CHIKV) is an arthritogenic reemerging virus replicating in plasma membrane-derived compartments termed "spherules." Here, we identify the human transmembrane protein CD81 as host factor required for CHIKV replication. Ablation of CD81 results in decreased CHIKV permissiveness, while overexpression enhances infection. CD81 is dispensable for virus uptake but critically required for viral genome replication. Likewise, murine CD81 is crucial for CHIKV permissiveness and is expressed in target cells such as dermal fibroblasts, muscle and liver cells. Whereas related alphaviruses, including Ross River virus (RRV), Semliki Forest virus (SFV), Sindbis virus (SINV) and Venezuelan equine encephalitis virus (VEEV), also depend on CD81 for infection, RNA viruses from other families, such as coronaviruses, replicate independently of CD81. Strikingly, the replication-enhancing function of CD81 is linked to cholesterol binding. These results define a mechanism exploited by alphaviruses to hijack the membrane microdomain-modeling protein CD81 for virus replication through interaction with cholesterol.IMPORTANCE: In this study, we discover the tetraspanin CD81 as a host factor for the globally emerging chikungunya virus and related alphaviruses. We show that CD81 promotes replication of viral genomes in human and mouse cells, while virus entry into cells is independent of CD81. This provides novel insights into how alphaviruses hijack host proteins to complete their life cycle. Alphaviruses replicate at distinct sites of the plasma membrane, which are enriched in cholesterol. We found that the cholesterol-binding ability of CD81 is important for its function as an alphavirus host factor. This discovery thus broadens our understanding of the alphavirus replication process and the use of host factors to reprogram cells into virus replication factories.
  •  
31.
  • Li, Dandan, et al. (författare)
  • ASC- and caspase-1-deficient C57BL/6 mice do not develop demyelinating disease after infection with Theiler's murine encephalomyelitis virus
  • 2023
  • Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Theiler's murine encephalomyelitis virus (TMEV) induces an acute polioencephalomyelitis and a chronic demyelinating leukomyelitis in SJL mice. C57BL/6 (B6) mice generally do not develop TMEV-induced demyelinating disease (TMEV-IDD) due to virus elimination. However, TMEV can persist in specific immunodeficient B6 mice such as IFNβ-/- mice and induce a demyelinating process. The proinflammatory cytokines IL-1β and IL-18 are activated by the inflammasome pathway, which consists of a pattern recognition receptor molecule sensing microbial pathogens, the adaptor molecule Apoptosis-associated speck-like protein containing a CARD (ASC), and the executioner caspase-1. To analyze the contribution of the inflammasome pathway to the resistance of B6 mice to TMEV-IDD, ASC- and caspase-1-deficient mice and wild type littermates were infected with TMEV and investigated using histology, immunohistochemistry, RT-qPCR, and Western Blot. Despite the antiviral activity of the inflammasome pathway, ASC- and caspase-1-deficient mice eliminated the virus and did not develop TMEV-IDD. Moreover, a similar IFNβ and cytokine gene expression was found in the brain of immunodeficient mice and their wild type littermates. Most importantly, Western Blot showed cleavage of IL-1β and IL-18 in all investigated mice. Consequently, inflammasome-dependent activation of IL-1β and IL-18 does not play a major role in the resistance of B6 mice to TMEV-IDD.
  •  
32.
  • Loll, Bernhard, et al. (författare)
  • Thermostability and Ca2+ binding properties of wild type and heterologously expressed PsbO protein from cyanobacterial photosystem II.
  • 2005
  • Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 44:12, s. 4691-8
  • Tidskriftsartikel (refereegranskat)abstract
    • Oxygenic photosynthesis takes place in the thylakoid membrane of cyanobacteria, algae, and higher plants. Initially light is absorbed by an oligomeric pigment-protein complex designated as photosystem II (PSII), which catalyzes light-induced water cleavage under release of molecular oxygen for the biosphere on our planet. The membrane-extrinsic manganese stabilizing protein (PsbO) is associated on the lumenal side of the thylakoids close to the redox-active (Mn)(4)Ca cluster at the catalytically active site of PSII. Recombinant PsbO from the thermophilic cyanobacterium Thermosynechococcus elongatus was expressed in Escherichia coli and spectroscopically characterized. The secondary structure of recombinant PsbO (recPsbO) was analyzed in the absence and presence of Ca(2+) using Fourier transform infrared spectroscopy (FTIR) and circular dichroism spectropolarimetry (CD). No significant structural changes could be observed when the PSII subunit was titrated with Ca(2+) in vitro. These findings are compared with data for spinach PsbO. Our results are discussed in the light of the recent 3D-structural analysis of the oxygen-evolving PSII and structural/thermodynamic differences between the two homologous proteins from thermophilic cyanobacteria and plants.
  •  
33.
  • Lump, Edina, et al. (författare)
  • A molecular tweezer antagonizes seminal amyloids and HIV infection
  • 2015
  • Ingår i: eLIFE. - 2050-084X. ; 4
  • Tidskriftsartikel (refereegranskat)abstract
    • Semen is the main vector for HIV transmission and contains amyloid fibrils that enhance viral infection. Available microbicides that target viral components have proven largely ineffective in preventing sexual virus transmission. In this study, we establish that CLR01, a 'molecular tweezer' specific for lysine and arginine residues, inhibits the formation of infectivity-enhancing seminal amyloids and remodels preformed fibrils. Moreover, CLR01 abrogates semen-mediated enhancement of viral infection by preventing the formation of virion-amyloid complexes and by directly disrupting the membrane integrity of HIV and other enveloped viruses. We establish that CLR01 acts by binding to the target lysine and arginine residues rather than by a non-specific, colloidal mechanism. CLR01 counteracts both host factors that may be important for HIV transmission and the pathogen itself. These combined anti-amyloid and antiviral activities make CLR01 a promising topical microbicide for blocking infection by HIV and other sexually transmitted viruses.
  •  
34.
  • Löw, Karin, et al. (författare)
  • Luminescent reporter cells enable the identification of broad-spectrum antivirals against emerging viruses
  • 2023
  • Ingår i: Journal of Medical Virology. - : John Wiley & Sons. - 0146-6615 .- 1096-9071. ; 95:11
  • Tidskriftsartikel (refereegranskat)abstract
    • The emerging viruses SARS-CoV-2 and arenaviruses cause severe respiratory and hemorrhagic diseases, respectively. The production of infectious particles of both viruses and virus spread in tissues requires cleavage of surface glycoproteins (GPs) by host proprotein convertases (PCs). SARS-CoV-2 and arenaviruses rely on GP cleavage by PCs furin and subtilisin kexin isozyme-1/site-1 protease (SKI-1/S1P), respectively. We report improved luciferase-based reporter cell lines, named luminescent inducible proprotein convertase reporter cells that we employ to monitor PC activity in its authentic subcellular compartment. Using these sensor lines we screened a small compound library in high-throughput manner. We identified 23 FDA-approved small molecules, among them monensin which displayed broad activity against furin and SKI-1/S1P. Monensin inhibited arenaviruses and SARS-CoV-2 in a dose-dependent manner. We observed a strong reduction in infectious particle release upon monensin treatment with little effect on released genome copies. This was reflected by inhibition of SARS-CoV-2 spike processing suggesting the release of immature particles. In a proof of concept experiment using human precision cut lung slices, monensin potently inhibited SARS-CoV-2 infection, evidenced by reduced infectious particle release. We propose that our PC sensor pipeline is a suitable tool to identify broad-spectrum antivirals with therapeutic potential to combat current and future emerging viruses.
  •  
35.
  • Marek, Katarzyna, et al. (författare)
  • Functional Granulocyte–Macrophage Colony-Stimulating Factor (GM-CSF) Delivered by Canine Histiocytic Sarcoma Cells Persistently Infected with Engineered Attenuated Canine Distemper Virus
  • 2023
  • Ingår i: Pathogens. - : MDPI. - 2076-0817. ; 12:7
  • Tidskriftsartikel (refereegranskat)abstract
    • The immune response plays a key role in the treatment of malignant tumors. One important molecule promoting humoral and cellular immunity is granulocyte–macrophage colony-stimulating factor (GM-CSF). Numerous successful trials have led to the approval of this immune-stimulating molecule for cancer therapy. However, besides immune stimulation, GM-CSF may also accelerate tumor cell proliferation, rendering this molecule a double-edged sword in cancer treatment. Therefore, detailed knowledge about the in vitro function of GM-CSF produced by infected tumor cells is urgently needed prior to investigations in an in vivo model. The aim of the present study was to functionally characterize a persistent infection of canine histiocytic sarcoma cells (DH82 cells) with the canine distemper virus strain Onderstepoort genetically engineered to express canine GM-CSF (CDV-Ondneon-GM-CSF). The investigations aimed (1) to prove the overall functionality of the virally induced production of GM-CSF and (2) to determine the effect of GM-CSF on the proliferation and motility of canine HS cells. Infected cells consistently produced high amounts of active, pH-stable GM-CSF, as demonstrated by increased proliferation of HeLa cells. By contrast, DH82 cells lacked increased proliferation and motility. The significantly increased secretion of GM-CSF by persistently CDV-Ondneon-GM-CSF-infected DH82 cells, the pH stability of this protein, and the lack of detrimental effects on DH82 cells renders this virus strain an interesting candidate for future studies aiming to enhance the oncolytic properties of CDV for the treatment of canine histiocytic sarcomas.
  •  
36.
  • Marek, Katarzyna, et al. (författare)
  • Persistent Infection of a Canine Histiocytic Sarcoma Cell Line with Attenuated Canine Distemper Virus Expressing Vasostatin or Granulocyte-Macrophage Colony-Stimulating Factor
  • 2022
  • Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 23:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Canine histiocytic sarcoma (HS) represents a neoplasia with poor prognosis. Due to the high metastatic rate of HS, there is urgency to improve treatment options and to prevent tumor metastases. Canine distemper virus (CDV) is a single-stranded negative-sense RNA (ssRNA (-)) virus with potentially oncolytic properties. Moreover, vasostatin and granulocyte-macrophage colony-stimulating factor (GM-CSF) are attractive molecules in cancer therapy research because of their anti-angiogenetic properties and potential modulation of the tumor microenvironment. In the present study, an in vitro characterization of two genetically engineered viruses based on the CDV strain Onderstepoort (CDV-Ond), CDV-Ondneon-vasostatin and CDV-Ondneon-GM-CSF was performed. Canine histiocytic sarcoma cells (DH82 cells) were persistently infected with CDV-Ond, CDV-Ondneon, CDV-Ondneon-vasostatin and CDV-Ondneon-GM-CSF and characterized on a molecular and protein level regarding their vasostatin and GM-CSF production. Interestingly, DH82 cells persistently infected with CDV-Ondneon-vasostatin showed a significantly increased number of vasostatin mRNA transcripts. Similarly, DH82 cells persistently infected with CDV-Ondneon-GM-CSF displayed an increased number of GM-CSF mRNA transcripts mirrored on the protein level as confirmed by immunofluorescence and Western blot. In summary, modified CDV-Ond strains expressed GM-CSF and vasostatin, rendering them promising candidates for the improvement of oncolytic virotherapies, which should be further detailed in future in vivo studies.
  •  
37.
  • Matthaei, Alina, et al. (författare)
  • Landscape of protein-protein interactions during hepatitis C virus assembly and release
  • 2024
  • Ingår i: Microbiology Spectrum. - : American Society for Microbiology. - 2165-0497. ; 12:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Assembly of infectious hepatitis C virus (HCV) particles requires multiple cellular proteins including for instance apolipoprotein E (ApoE). To describe these protein-protein interactions, we performed an affinity purification mass spectrometry screen of HCV-infected cells. We used functional viral constructs with epitope-tagged envelope protein 2 (E2), protein (p) 7, or nonstructural protein 4B (NS4B) as well as cells expressing a tagged variant of ApoE. We also evaluated assembly stage-dependent remodeling of protein complexes by using viral mutants carrying point mutations abrogating particle production at distinct steps of the HCV particle production cascade. Five ApoE binding proteins, 12 p7 binders, 7 primary E2 interactors, and 24 proteins interacting with NS4B were detected. Cell-derived PREB, STT3B, and SPCS2 as well as viral NS2 interacted with both p7 and E2. Only GTF3C3 interacted with E2 and NS4B, highlighting that HCV assembly and replication complexes exhibit largely distinct interactomes. An HCV core protein mutation, preventing core protein decoration of lipid droplets, profoundly altered the E2 interactome. In cells replicating this mutant, E2 interactions with HSPA5, STT3A/B, RAD23A/B, and ZNF860 were significantly enhanced, suggesting that E2 protein interactions partly depend on core protein functions. Bioinformatic and functional studies including STRING network analyses, RNA interference, and ectopic expression support a role of Rad23A and Rad23B in facilitating HCV infectious virus production. Both Rad23A and Rad23B are involved in the endoplasmic reticulum (ER)-associated protein degradation (ERAD). Collectively, our results provide a map of host proteins interacting with HCV assembly proteins, and they give evidence for the involvement of ER protein folding machineries and the ERAD pathway in the late stages of the HCV replication cycle.IMPORTANCEHepatitis C virus (HCV) establishes chronic infections in the majority of exposed individuals. This capacity likely depends on viral immune evasion strategies. One feature likely contributing to persistence is the formation of so-called lipo-viro particles. These peculiar virions consist of viral structural proteins and cellular lipids and lipoproteins, the latter of which aid in viral attachment and cell entry and likely antibody escape. To learn about how lipo-viro particles are coined, here, we provide a comprehensive overview of protein-protein interactions in virus-producing cells. We identify numerous novel and specific HCV E2, p7, and cellular apolipoprotein E-interacting proteins. Pathway analyses of these interactors show that proteins participating in processes such as endoplasmic reticulum (ER) protein folding, ER-associated protein degradation, and glycosylation are heavily engaged in virus production. Moreover, we find that the proteome of HCV replication sites is distinct from the assembly proteome, suggesting that transport process likely shuttles viral RNA to assembly sites.
  •  
38.
  • Mhlekude, Baxolele, et al. (författare)
  • Pharmacological inhibition of bromodomain and extra-terminal proteins induces an NRF-2-mediated antiviral state that is subverted by SARS-CoV-2 infection
  • 2023
  • Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 19:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Inhibitors of bromodomain and extra-terminal proteins (iBETs), including JQ-1, have been suggested as potential prophylactics against SARS-CoV-2 infection. However, molecular mechanisms underlying JQ-1-mediated antiviral activity and its susceptibility to viral subversion remain incompletely understood. Pretreatment of cells with iBETs inhibited infection by SARS-CoV-2 variants and SARS-CoV, but not MERS-CoV. The antiviral activity manifested itself by reduced reporter expression of recombinant viruses, and reduced viral RNA quantities and infectious titers in the culture supernatant. While we confirmed JQ-1-mediated downregulation of expression of angiotensin-converting enzyme 2 (ACE2) and interferon-stimulated genes (ISGs), multi-omics analysis addressing the chromatin accessibility, transcriptome and proteome uncovered induction of an antiviral nuclear factor erythroid 2-related factor 2 (NRF-2)-mediated cytoprotective response as an additional mechanism through which JQ-1 inhibits SARS-CoV-2 replication. Pharmacological inhibition of NRF-2, and knockdown of NRF-2 and its target genes reduced JQ-1-mediated inhibition of SARS-CoV-2 replication. Serial passaging of SARS-CoV-2 in the presence of JQ-1 resulted in predominance of ORF6-deficient variant, which exhibited resistance to JQ-1 and increased sensitivity to exogenously administered type I interferon (IFN-I), suggesting a minimised need for SARS-CoV-2 ORF6-mediated repression of IFN signalling in the presence of JQ-1. Importantly, JQ-1 exhibited a transient antiviral activity when administered prophylactically in human airway bronchial epithelial cells (hBAECs), which was gradually subverted by SARS-CoV-2, and no antiviral activity when administered therapeutically following an established infection. We propose that JQ-1 exerts pleiotropic effects that collectively induce an antiviral state in the host, which is ultimately nullified by SARS-CoV-2 infection, raising questions about the clinical suitability of the iBETs in the context of COVID-19.
  •  
39.
  • Mhlekude, Baxolele, et al. (författare)
  • The barrier functions of crude cervical mucus plugs against HIV-1 infection in the context of cell-free and cell-to-cell transmission
  • 2021
  • Ingår i: AIDS. - : Wolters Kluwer. - 0269-9370 .- 1473-5571. ; 35:13, s. 2105-2117
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: The cervical mucus plugs are enriched with proteins of known immunological functions. We aimed to characterize the anti-HIV-1 activity of the cervical mucus plugs against a panel of different HIV-1 strains in the contexts of cell-free and cell-associated virus.DESIGN: A cohort of consenting HIV-1-negative and HIV-1-positive pregnant women in labour was recruited from Mthatha General Hospital in the Eastern Cape province of South Africa, from whom the cervical mucus plugs were collected in 6 M guanidinium chloride with protease inhibitors and transported to our laboratories at -80 °C.METHODS: Samples were centrifuged to remove insoluble material and dialysed before freeze--drying and subjecting them to the cell viability assays. The antiviral activities of the samples were studied using luminometric reporter assays and flow cytometry. Time-of-addition and BlaM-Vpr virus-cell fusion assays were used to pin-point the antiviral mechanisms of the cervical mucus plugs, before proteomic profiling using liquid chromatography-tandem mass spectrometry.RESULTS: The proteinaceous fraction of the cervical mucus plugs exhibited anti-HIV-1 activity with inter-individual variations and some degree of specificity among different HIV-1 strains. Cell-associated HIV-1 was less susceptible to inhibition by the potent samples whenever compared with the cell-free HIV-1. The samples with high antiviral potency exhibited a distinct proteomic profile when compared with the less potent samples.CONCLUSION: The crude cervical mucus plugs exhibit anti-HIV-1 activity, which is defined by a specific proteomic profile.
  •  
40.
  • Moreno, Hector, et al. (författare)
  • A novel circulating tamiami mammarenavirus shows potential for zoonotic spillover
  • 2020
  • Ingår i: PLoS Neglected Tropical Diseases. - : Public Library of Science. - 1935-2727 .- 1935-2735. ; 14:12
  • Tidskriftsartikel (refereegranskat)abstract
    • A detailed understanding of the mechanisms underlying the capacity of a virus to break the species barrier is crucial for pathogen surveillance and control. New World (NW) mammarenaviruses constitute a diverse group of rodent-borne pathogens that includes several causative agents of severe viral hemorrhagic fever in humans. The ability of the NW mammarenaviral attachment glycoprotein (GP) to utilize human transferrin receptor 1 (hTfR1) as a primary entry receptor plays a key role in dictating zoonotic potential. The recent isolation of Tacaribe and lymphocytic choriominingitis mammarenaviruses from host-seeking ticks provided evidence for the presence of mammarenaviruses in arthropods, which are established vectors for numerous other viral pathogens. Here, using next generation sequencing to search for other mammarenaviruses in ticks, we identified a novel replication-competent strain of the NW mammarenavirus Tamiami (TAMV-FL), which we found capable of utilizing hTfR1 to enter mammalian cells. During isolation through serial passaging in mammalian immunocompetent cells, the quasispecies of TAMV-FL acquired and enriched mutations leading to the amino acid changes N151K and D156N, within GP. Cell entry studies revealed that both substitutions, N151K and D156N, increased dependence of the virus on hTfR1 and binding to heparan sulfate proteoglycans. Moreover, we show that the substituted residues likely map to the sterically constrained trimeric axis of GP, and facilitate viral fusion at a lower pH, resulting in viral egress from later endosomal compartments. In summary, we identify and characterize a naturally occurring TAMV strain (TAMV-FL) within ticks that is able to utilize hTfR1. The TAMV-FL significantly diverged from previous TAMV isolates, demonstrating that TAMV quasispecies exhibit striking genetic plasticity that may facilitate zoonotic spillover and rapid adaptation to new hosts.
  •  
41.
  • Moreno, Hector, et al. (författare)
  • Comparison of the Innate Immune Responses to Pathogenic and Nonpathogenic Clade B New World Arenaviruses
  • 2019
  • Ingår i: Journal of Virology. - Washington : American Society of Microbiology. - 0022-538X .- 1098-5514. ; 93:19
  • Tidskriftsartikel (refereegranskat)abstract
    • The New World (NW) arenaviruses are a diverse group of zoonotic viruses, including several causative agents of severe hemorrhagic fevers in humans. All known human-pathogenic NW arenaviruses belong to Glade B, where they group into sublineages with phylogenetically closely related nonpathogenic viruses, e.g., the highly pathogenic Junin (JUNV) and Machupo viruses with the nonpathogenic Tacaribe virus (TCRV). Considering the close genetic relationship of nonpathogenic and pathogenic NW arenaviruses, the identification of molecular determinants of virulence is of great importance. The host cell's innate antiviral defense represents a major barrier for zoonotic infection. Here, we performed a side-by-side comparison of the innate immune responses against JUNV and TCRV in human cells. Despite similar levels of viral replication, infection with TCRV consistently induced a stronger type I interferon (IFN-I) response than JUNV infection did. Transcriptome profiling revealed upregulation of a largely overlapping set of interferon-stimulated genes in cells infected with TCRV and JUNV. Both viruses were relatively insensitive to IFN-I treatment of human cells and induced similar levels of apoptosis in the presence or absence of an IFN-I response. However, in comparison to JUNV, TCRV induced stronger activation of the innate sensor double-strand RNA-dependent protein kinase R (PKR), resulting in phosphorylation of eukaryotic translation initiation factor eIF2 alpha. Confocal microscopy studies revealed similar subcellular colocalizations of the JUNV and TCRV viral replication-transcription complexes with PKR. However, deletion of PKR by CRISPR/Cas9 hardly affected JUNV but promoted TCRV multiplication, providing the first evidence for differential innate recognition and control of pathogenic and nonpathogenic NW arenaviruses by PKR.IMPORTANCE New World (NW) arenaviruses are a diverse family of emerging zoonotic viruses that merit significant attention as important public health problems. The close genetic relationship of nonpathogenic NW arenaviruses with their highly pathogenic cousins suggests that few mutations may be sufficient to enhance virulence. The identification of molecular determinants of virulence of NW arenaviruses is therefore of great importance. Here we undertook a side-by-side comparison of the innate immune responses against the highly pathogenic Junin virus (JUNV) and the related nonpathogenic Tacaribe virus (TCRV) in human cells. We consistently found that TCRV induces a stronger type I interferon (IFN-I) response than JUNV. Transcriptome profiling revealed an overlapping pattern of IFN-induced gene expression and similar low sensitivities to IFN-I treatment. However, the double-stranded RNA (dsRNA)-dependent protein kinase R (PKR) contributed to the control of TCRV, but not JUNV, providing the first evidence for differential innate recognition and control of JUNV and TCRV.
  •  
42.
  • Nicolay, Wiebke, et al. (författare)
  • Characterization of rna sensing pathways in hepatoma cell lines and primary human hepatocytes
  • 2021
  • Ingår i: Cells. - : MDPI. - 2073-4409. ; 10:11
  • Tidskriftsartikel (refereegranskat)abstract
    • The liver is targeted by several human pathogenic RNA viruses for viral replication and dissemination; despite this, the extent of innate immune sensing of RNA viruses by human hepatocytes is insufficiently understood to date. In particular, for highly human tropic viruses such as hepatitis C virus, cell culture models are needed to study immune sensing. However, several human hepatoma cell lines have impaired RNA sensing pathways and fail to mimic innate immune responses in the human liver. Here we compare the RNA sensing properties of six human hepatoma cell lines, namely Huh-6, Huh-7, HepG2, HepG2-HFL, Hep3B, and HepaRG, with primary human hepatocytes. We show that primary liver cells sense RNA through retinoic acid-inducible gene I (RIG-I) like receptor (RLR) and Toll-like receptor 3 (TLR3) pathways. Of the tested cell lines, Hep3B cells most closely mimicked the RLR and TLR3 mediated sensing in primary hepatocytes. This was shown by the expression of RLRs and TLR3 as well as the expression and release of bioactive interferon in primary hepatocytes and Hep3B cells. Our work shows that Hep3B cells partially mimic RNA sensing in primary hepatocytes and thus can serve as in vitro model to study innate immunity to RNA viruses in hepatocytes.
  •  
43.
  • Palor, Machaela, et al. (författare)
  • Cholesterol sensing by CD81 is important for hepatitis C virus entry
  • 2020
  • Ingår i: Journal of Biological Chemistry. - : Elsevier. - 0021-9258 .- 1083-351X. ; 295:50, s. 16931-16948
  • Tidskriftsartikel (refereegranskat)abstract
    • 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.
  •  
44.
  • Passos, Vania, et al. (författare)
  • Innate immune response to SARS-CoV-2 infection contributes to neuronal damage in human iPSC-derived peripheral neurons
  • 2024
  • Ingår i: Journal of Medical Virology. - : John Wiley & Sons. - 0146-6615 .- 1096-9071. ; 96:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Severe acute respiratory coronavirus 2 (SARS-CoV-2) causes neurological disease in the peripheral and central nervous system (PNS and CNS, respectively) of some patients. It is not clear whether SARS-CoV-2 infection or the subsequent immune response are the key factors that cause neurological disease. Here, we addressed this question by infecting human induced pluripotent stem cell-derived CNS and PNS neurons with SARS-CoV-2. SARS-CoV-2 infected a low number of CNS neurons and did not elicit a robust innate immune response. On the contrary, SARS-CoV-2 infected a higher number of PNS neurons. This resulted in expression of interferon (IFN) λ1, several IFN-stimulated genes and proinflammatory cytokines. The PNS neurons also displayed alterations characteristic of neuronal damage, as increased levels of sterile alpha and Toll/interleukin receptor motif-containing protein 1, amyloid precursor protein and α-synuclein, and lower levels of cytoskeletal proteins. Interestingly, blockade of the Janus kinase and signal transducer and activator of transcription pathway by Ruxolitinib did not increase SARS-CoV-2 infection, but reduced neuronal damage, suggesting that an exacerbated neuronal innate immune response contributes to pathogenesis in the PNS. Our results provide a basis to study coronavirus disease 2019 (COVID-19) related neuronal pathology and to test future preventive or therapeutic strategies.
  •  
45.
  • Ricke-Hoch, Melanie, et al. (författare)
  • Impaired immune response mediated by prostaglandin E2 promotes severe COVID-19 disease
  • 2021
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:8
  • Tidskriftsartikel (refereegranskat)abstract
    • The SARS-CoV-2 coronavirus has led to a pandemic with millions of people affected. The present study finds that risk-factors for severe COVID-19 disease courses, i.e. male sex, older age and sedentary life style are associated with higher prostaglandin E2 (PGE2) serum levels in blood samples from unaffected subjects. In COVID-19 patients, PGE2 blood levels are markedly elevated and correlate positively with disease severity. SARS-CoV-2 induces PGE2 generation and secretion in infected lung epithelial cells by upregulating cyclo-oxygenase (COX)-2 and reducing the PG-degrading enzyme 15-hydroxyprostaglan-din-dehydrogenase. Also living human precision cut lung slices (PCLS) infected with SARS-CoV-2 display upregulated COX-2. Regular exercise in aged individuals lowers PGE2 serum levels, which leads to increased Paired-Box-Protein-Pax-5 (PAX5) expression, a master regulator of B-cell survival, proliferation and differentiation also towards long lived memory B-cells, in human pre-B-cell lines. Moreover, PGE2 levels in serum of COVID-19 patients lowers the expression of PAX5 in human pre-B-cell lines. The PGE2 inhibitor Taxifolin reduces SARS-CoV-2-induced PGE2 production. In conclusion, SARS-CoV-2, male sex, old age, and sedentary life style increase PGE2 levels, which may reduce the early anti-viral defense as well as the development of immunity promoting severe disease courses and multiple infections. Regular exercise and Taxifolin treatment may reduce these risks and prevent severe disease courses.
  •  
46.
  • Scull, Margaret A, et al. (författare)
  • Hepatitis C virus infects rhesus macaque hepatocytes and simianized mice.
  • 2015
  • Ingår i: Hepatology. - : Ovid Technologies (Wolters Kluwer Health). - 0270-9139 .- 1527-3350. ; 62:1, s. 57-67
  • Tidskriftsartikel (refereegranskat)abstract
    • UNLABELLED: At least 170 million people are chronically infected with hepatitis C virus (HCV). Owing to the narrow host range of HCV and restricted use of chimpanzees, there is currently no suitable animal model for HCV pathogenesis studies or the development of a HCV vaccine. To identify cellular determinants of interspecies transmission and establish a novel immunocompetent model system, we examined the ability of HCV to infect hepatocytes from a small nonhuman primate, the rhesus macaque (Macaca mulatta). We show that the rhesus orthologs of critical HCV entry factors support viral glycoprotein-dependent virion uptake. Primary hepatocytes from rhesus macaques are also permissive for HCV-RNA replication and particle production, which is enhanced when antiviral signaling is suppressed. We demonstrate that this may be owing to the diminished capacity of HCV to antagonize mitochondrial antiviral-signaling protein-dependent innate cellular defenses. To test the ability of HCV to establish persistent replication in vivo, we engrafted primary rhesus macaque hepatocytes into immunocompromised xenorecipients. Inoculation of resulting simian liver chimeric mice with either HCV genotype 1a or 2a resulted in HCV serum viremia for up to 10 weeks.CONCLUSION: Together, these data indicate that rhesus macaques may be a viable model for HCV and implicate host immunity as a potential species-specific barrier to HCV infection. We conclude that suppression of host immunity or further viral adaptation may allow robust HCV infection in rhesus macaques and creation of a new animal model for studies of HCV pathogenesis, lentivirus coinfection, and vaccine development.
  •  
47.
  • Thorsteinsson, Konrad, 1991- (författare)
  • Probing and elucidating the dynamics of virus-membrane interaction via plasma membrane mimics
  • 2023
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Virus infection is initiated by the attachment of a virion to a susceptible cell’s plasma membrane, in a highly dynamic and well-orchestrated process that encompasses various steps and engages numerous viral and cellular factors. These dynamic steps may include initial non-specific binding to ubiquitous cell-membrane ligands, diffusion across the membrane to a suitable entry site and virus engagement with various receptors and co-receptors on the cell surface. Molecules and processes involved may vary across virus species, but it is likely that in all cases the dynamics of virus-membrane interactions need to be carefully fine-tuned to optimize the entry process. Nevertheless, the investigation and characterization of the involved biomolecular interactions are often oversimplified to isolated virus-receptor pairs engagement, ignoring the complexity of the membrane and the dynamic behaviors of the interaction. This doctoral thesis aims to shed light on this critical sphere of virus-membrane interactions, focusing on how viruses dynamically engage with plasma membrane molecules to successfully infect the cell. To facilitate this research, we utilized an innovative approach of using plasma membrane mimics to explore how viruses dynamically interact with the plasma membrane across several chosen contexts.Central to this project was the development and optimization of cell membrane mimics consisting of supported lipid bilayers (SLBs) reflecting the compositional complexity of the membrane. In the first paper, we developed a method to quantify the membrane material in a lipid vesicle sample in terms of total membrane surface area. This method is vital for the full utilization of our membrane mimics, which in many cases require the mixing of different vesicles in specific ratios.Subsequently, cell membrane mimics of complex composition were used to investigate the molecular mechanisms modulating virus-membrane interactions in several chosen contexts. These investigations relied primarily on total internal reflection fluorescent microscopy to characterize the attachment and detachment behavior of individual virus particles from the membrane. Firstly, studies focused on norovirus, a pathogen that infects cells in the gastrointestinal tract. The virus is known to bind to histo-blood group antigens (HGBA), specific glycans found on intestinal epithelial cells membranes. However, susceptibility to norovirus infection varies between individuals, and the difference is correlated to the specific glycan expression of the intestinal cells. This suggests that the differences in susceptibility might be related to differences in virus-membrane interaction dynamics. Using membranes constructed from lipids extracted from human intestinal enteroids (HIE) derived from susceptible and non-susceptible individuals, it was determined that norovirus associates similarly to both susceptible and non-susceptible membranes but dissociates slower from susceptible membranes. Using native supported lipid bilayers (nSLBs), bilayers derived from plasma membrane extracts of the HIEs, we then investigated the contribution of different carbohydrate moieties to interaction kinetics. This investigation revealed that virus binding to fucose residues on HBGAs is only part of the interaction, and that the virus also binds to sialic acid to a similar degree. It was also found that binding occurs primarily to membrane glycoproteins, and not membrane glycolipids.nSLBs were further found to be highly useful complements to virological investigations in a number of contexts. First, we studied the effect of isoform 4 of apolipoprotein E (ApoE4) on herpes simplex virus 1 (HSV-1) binding kinetics to plasma membrane SLBs. ApoE4 is a lipid binding protein that has been found, in conjunction with HSV-1, to be a risk factor for Alzheimer's disease. We showed that membrane-bound ApoE4 does not affect HSV-1 binding kinetics, but that viruses coated with ApoE4 demonstrate faster dissociation from susceptible membranes than non-coated viruses, indicating that the protein facilitates the release of new virions from the infected cell. This provides a mechanistic understanding of the overall pro-viral effect of ApoE, observed in infection experiments.Second, nSLBs from respiratory epithelial cells were used to quantify binding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the plasma membrane. SARS-CoV-2 has caused one of the largest pandemic in modern history and the virus has shown the ability to rapidly mutate, causing periodic surges of new cases, with newer strains spreading more easily. These mutations have often been linked to the viral spike glycoprotein, responsible for viral attachment and entry. Investigations using spike-decorated liposomes as virus-mimetics, revealed that virus-membrane interaction dynamics vary for different variants of concerns. Specifically, the late Omicron variant, a highly transmissible variant, shows significantly increased affinity to susceptible membranes. This increased affinity was primarily due to increased association to the membrane. Experiments also showed that membrane-bound heparan sulfate has an inhibiting effect on virus binding to ACE2, for earlier variants.In summary, we have successfully implemented membrane mimics with different levels of complexity to investigate virus-membrane interactions. This thesis demonstrates their potential in virology research in several contexts, including measuring the avidity of viruses to membranes, evaluating the relative contributions of different attachment factors to kinetics, and the influence of viral and cellular factors on binding.
  •  
48.
  • Uckeley, Zina M., et al. (författare)
  • Quantitative Proteomics of Uukuniemi Virus-host Cell Interactions Reveals GBF1 as Proviral Host Factor for Phleboviruses
  • 2019
  • Ingår i: Molecular & Cellular Proteomics. - : American Society for Biochemistry and Molecular Biology. - 1535-9476 .- 1535-9484. ; 18:12, s. 2401-2417
  • Tidskriftsartikel (refereegranskat)abstract
    • Novel tick-borne phleboviruses in the Phenuiviridae family, which are highly pathogenic in humans and all closely related to Uukuniemi virus (UUKV), have recently emerged on different continents. How phleboviruses assemble, bud, and exit cells remains largely elusive. Here, we performed high-resolution, label-free mass spectrometry analysis of UUKV immunoprecipitated from cell lysates and identified 39 cellular partners interacting with the viral envelope glycoproteins. The importance of these host factors for UUKV infection was validated by silencing each host factor by RNA interference. This revealed Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1 (GBF1), a guanine nucleotide exchange factor resident in the Golgi, as a critical host factor required for the UUKV life cycle. An inhibitor of GBF1, Golgicide A, confirmed the role of the cellular factor in UUKV infection. We could pinpoint the GBF1 requirement to UUKV replication and particle assembly. When the investigation was extended to viruses from various positive and negative RNA viral families, we found that not only phleboviruses rely on GBF1 for infection, but also Flavi-, Corona-, Rhabdo-, and Togaviridae. In contrast, silencing or blocking GBF1 did not abrogate infection by the human adenovirus serotype 5 and immunodeficiency retrovirus type 1, the replication of both requires nuclear steps. Together our results indicate that UUKV relies on GBF1 for viral replication, assembly and egress. This study also highlights the proviral activity of GBF1 in the infection by a broad range of important zoonotic RNA viruses. Ticks are important vectors of infectious emerging diseases and tick-borne phleboviruses represent a growing threat to humans globally. We employed here a high-resolution, label-free mass spectrometry and RNA interference screen approach to reveal the host cell protein GBF1 as a proviral factor, not only for tick-borne phleboviruses, but also for many other important zoonotic RNA viruses. This study lays the basis for the development of innovative antiviral strategies against a broad range of human pathogenic viruses.
  •  
49.
  • Victoria, Catherine, et al. (författare)
  • Halogenated rocaglate derivatives : pan-antiviral agents against hepatitis E virus and emerging viruses
  • 2024
  • Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 67:1, s. 289-321
  • Tidskriftsartikel (refereegranskat)abstract
    • The synthesis of a library of halogenated rocaglate derivatives belonging to the flavagline class of natural products, of which silvestrol is the most prominent example, is reported. Their antiviral activity and cytotoxicity profile against a wide range of pathogenic viruses, including hepatitis E, Chikungunya, Rift Valley Fever virus and SARS-CoV-2, were determined. The incorporation of halogen substituents at positions 4′, 6 and 8 was shown to have a significant effect on the antiviral activity of rocaglates, some of which even showed enhanced activity compared to CR-31-B and silvestrol.
  •  
50.
  • Vieyres, Gabrielle, et al. (författare)
  • ABHD5/CGI-58, the Chanarin-Dorfman Syndrome Protein, Mobilises Lipid Stores for Hepatitis C Virus Production
  • 2016
  • Ingår i: PLoS Pathogens. - : Public Library Science. - 1553-7366 .- 1553-7374. ; 12:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Hepatitis C virus (HCV) particles closely mimic human very-low-density lipoproteins (VLDL) to evade humoral immunity and to facilitate cell entry. However, the principles that govern HCV association with VLDL components are poorly defined. Using an siRNA screen, we identified ABHD5 (α/β hydrolase domain containing protein 5, also known as CGI-58) as a new host factor promoting both virus assembly and release. ABHD5 associated with lipid droplets and triggered their hydrolysis. Importantly, ABHD5 Chanarin-Dorfman syndrome mutants responsible for a rare lipid storage disorder in humans were mislocalised, and unable to consume lipid droplets or support HCV production. Additional ABHD5 mutagenesis revealed a novel tribasic motif that does not influence subcellular localization but determines both ABHD5 lipolytic and proviral properties. These results indicate that HCV taps into the lipid droplet triglyceride reservoir usurping ABHD5 lipase cofactor function. They also suggest that the resulting lipid flux, normally devoted to VLDL synthesis, also participates in the assembly and release of the HCV lipo-viro-particle. Altogether, our study provides the first association between the Chanarin-Dorfman syndrome protein and an infectious disease and sheds light on the hepatic manifestations of this rare genetic disorder as well as on HCV morphogenesis.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 56
Typ av publikation
tidskriftsartikel (53)
doktorsavhandling (1)
forskningsöversikt (1)
bokkapitel (1)
Typ av innehåll
refereegranskat (55)
övrigt vetenskapligt/konstnärligt (1)
Författare/redaktör
Gerold, Gisa, 1979- (55)
Pietschmann, Thomas (20)
Lasswitz, Lisa (10)
Moeller, Rebecca (9)
Zapatero-Belinchón, ... (9)
Rice, Charles M. (8)
visa fler...
Bruening, Janina (7)
Brogden, Graham (7)
Baumgärtner, Wolfgan ... (6)
Kunz, Stefan (6)
Kirui, Jared (5)
Becker, Miriam (5)
Vondran, Florian W. ... (5)
Ploss, Alexander (5)
Meissner, Felix (5)
Carriquí-Madroñal, B ... (5)
Kahl, Sina (4)
Vieyres, Gabrielle (4)
Kaderali, Lars (4)
Fedeli, Chiara (4)
Moreno, Hector (4)
Lenman, Annasara, 19 ... (3)
Stegmann, Cora (3)
Sheldon, Julie (3)
Welsch, Kathrin (3)
von Hahn, Thomas (3)
Gunesch, Antonia P. (3)
Bally, Marta (2)
Pich, Andreas (2)
Överby, Anna K. (2)
Alberione, Maria Pia (2)
Ginkel, Corinne (2)
Arnberg, Niklas, 198 ... (2)
Banse, Pia (2)
Khan, Abdul G (2)
Marcotrigiano, Josep ... (2)
Zychlinsky, Arturo (2)
Brown, Richard J. P. (2)
Joecks, Sebastian (2)
Bankwitz, Dorothea (2)
Steinmann, Eike (2)
Krey, Thomas (2)
Meuleman, Philip (2)
Vondran, Florian W. (2)
Weigel, Bettina (2)
Möller, Rebecca (2)
de Diego, Juana L (2)
Matthaei, Alina (2)
Schulz, Thomas F. (2)
Islam, Md. Koushikul ... (2)
visa färre...
Lärosäte
Umeå universitet (56)
Språk
Engelska (56)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (43)
Naturvetenskap (7)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy