1
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Bodmer BS, Hoenen T, Wendt L. Molecular insights into the Ebola virus life cycle. Nat Microbiol 2024; 9:1417-1426. [PMID: 38783022 DOI: 10.1038/s41564-024-01703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 04/17/2024] [Indexed: 05/25/2024]
Abstract
Ebola virus and other orthoebolaviruses cause severe haemorrhagic fevers in humans, with very high case fatality rates. Their non-segmented single-stranded RNA genome encodes only seven structural proteins and a small number of non-structural proteins to facilitate the virus life cycle. The basics of this life cycle are well established, but recent advances have substantially increased our understanding of its molecular details, including the viral and host factors involved. Here we provide a comprehensive overview of our current knowledge of the molecular details of the orthoebolavirus life cycle, with a special focus on proviral host factors. We discuss the multistep entry process, viral RNA synthesis in specialized phase-separated intracellular compartments called inclusion bodies, the expression of viral proteins and ultimately the assembly of new virus particles and their release at the cell surface. In doing so, we integrate recent studies into the increasingly detailed model that has developed for these fundamental aspects of orthoebolavirus biology.
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Affiliation(s)
- Bianca S Bodmer
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany.
| | - Lisa Wendt
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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2
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Miao YR, Rankin EB, Giaccia AJ. Therapeutic targeting of the functionally elusive TAM receptor family. Nat Rev Drug Discov 2024; 23:201-217. [PMID: 38092952 DOI: 10.1038/s41573-023-00846-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2023] [Indexed: 03/07/2024]
Abstract
The TAM receptor family of TYRO3, AXL and MERTK regulates tissue and immune homeostasis. Aberrant TAM receptor signalling has been linked to a range of diseases, including cancer, fibrosis and viral infections. Specifically, the dysregulation of TAM receptors can enhance tumour growth and metastasis due to their involvement in multiple oncogenic pathways. For example, TAM receptors have been implicated in the epithelial-mesenchymal transition, maintaining the stem cell phenotype, immune modulation, proliferation, angiogenesis and resistance to conventional and targeted therapies. Therapeutically, multiple TAM receptor inhibitors are in preclinical and clinical development for cancers and other indications, with those targeting AXL being the most clinically advanced. Although there has been notable clinical advancement in recent years, challenges persist. This Review aims to provide both biological and clinical insights into the current therapeutic landscape of TAM receptor inhibitors, and evaluates their potential for the treatment of cancer and non-malignant diseases.
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Affiliation(s)
- Yu Rebecca Miao
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Erinn B Rankin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
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3
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Lamothe-Reyes Y, Figueroa M, Sánchez O. Host cell factors involved in classical swine fever virus entry. Vet Res 2023; 54:115. [PMID: 38041163 PMCID: PMC10693020 DOI: 10.1186/s13567-023-01238-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/03/2023] [Indexed: 12/03/2023] Open
Abstract
Classical swine fever virus (CSFV) is an ancient pathogen that continues to pose a threat to animal agriculture worldwide. The virus belongs to the genus Pestivirus and the family Flaviviridae. It causes a multisystemic disease that affects only pigs and is responsible for significant economic losses. CSFV infection is probably a multistep process that involves the proteins in the virus envelope and more than one receptor in the membrane of permissive cells. To date, the cellular receptors essential for CSFV entry and their detailed functions during this process remains unknown. All the viral envelope proteins Erns, E1 and E2 are involved in the entry process to some extent and the experimental approaches conducted until now have helped to unveil their contributions. This review aims to provide an overview of current knowledge on cellular molecules described to be involved in CSFV entry, including complement regulatory protein 46 (CD46), heparan sulphate (HS), Laminin receptor, Integrin ß3, Annexin II, MERKT and ADAM17. This knowledge would not only help to understand the molecular mechanisms involved in pestivirus infection, but also provide a rational basis for the development of nonvaccinal alternatives for CSFV control.
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Affiliation(s)
- Yaneysis Lamothe-Reyes
- Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile.
- Laboratory of Recombinant Biopharmaceuticals, Department of Pharmacology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile.
| | - Maximiliano Figueroa
- Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
| | - Oliberto Sánchez
- Laboratory of Recombinant Biopharmaceuticals, Department of Pharmacology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile.
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4
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Guo X, Zhang M, Liu X, Zhang Y, Wang C, Guo Y. Attachment, Entry, and Intracellular Trafficking of Classical Swine Fever Virus. Viruses 2023; 15:1870. [PMID: 37766277 PMCID: PMC10534341 DOI: 10.3390/v15091870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Classical swine fever virus (CSFV), which is a positive-sense, single-stranded RNA virus with an envelope, is a member of the Pestivirus genus in the Flaviviridae family. CSFV causes a severe and highly contagious disease in pigs and is prevalent worldwide, threatening the pig farming industry. The detailed mechanisms of the CSFV life cycle have been reported, but are still limited. Some receptors and attachment factors of CSFV, including heparan sulfate (HS), laminin receptor (LamR), complement regulatory protein (CD46), MER tyrosine kinase (MERTK), disintegrin, and metalloproteinase domain-containing protein 17 (ADAM17), were identified. After attachment, CSFV internalizes via clathrin-mediated endocytosis (CME) and/or caveolae/raft-dependent endocytosis (CavME). After internalization, CSFV moves to early and late endosomes before uncoating. During this period, intracellular trafficking of CSFV relies on components of the endosomal sorting complex required for transport (ESCRT) and Rab proteins in the endosome dynamics, with a dependence on the cytoskeleton network. This review summarizes the data on the mechanisms of CSFV attachment, internalization pathways, and intracellular trafficking, and provides a general view of the early events in the CSFV life cycle.
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Affiliation(s)
| | | | | | | | | | - Yidi Guo
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130012, China
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5
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Stewart CM, Bo Y, Fu K, Chan M, Kozak R, Apperley KYP, Laroche G, Daniel R, Beauchemin AM, Kobinger G, Kobasa D, Côté M. Sphingosine Kinases Promote Ebola Virus Infection and Can Be Targeted to Inhibit Filoviruses, Coronaviruses, and Arenaviruses Using Late Endocytic Trafficking to Enter Cells. ACS Infect Dis 2023; 9:1064-1077. [PMID: 37053583 DOI: 10.1021/acsinfecdis.2c00416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Entry of enveloped viruses in host cells requires the fusion of viral and host cell membranes, a process that is facilitated by viral fusion proteins protruding from the viral envelope. These viral fusion proteins need to be triggered by host factors, and for some viruses, this event occurs inside endosomes and/or lysosomes. Consequently, these 'late-penetrating viruses' must be internalized and delivered to entry-conducive intracellular vesicles. Because endocytosis and vesicular trafficking are tightly regulated cellular processes, late-penetrating viruses also depend on specific host proteins for efficient delivery to the site of fusion, suggesting that these could be targeted for antiviral therapy. In this study, we investigated a role for sphingosine kinases (SKs) in viral entry and found that chemical inhibition of sphingosine kinase 1 (SK1) and/or SK2 and knockdown of SK1/2 inhibited entry of Ebola virus (EBOV) into host cells. Mechanistically, inhibition of SK1/2 prevented EBOV from reaching late-endosomes and lysosomes that contain the EBOV receptor, Niemann Pick C1 (NPC1). Furthermore, we present evidence that suggests that the trafficking defect caused by SK1/2 inhibition occurs independently of sphingosine-1-phosphate (S1P) signaling through cell-surface S1P receptors. Lastly, we found that chemical inhibition of SK1/2 prevents entry of other late-penetrating viruses, including arenaviruses and coronaviruses, and inhibits infection by replication-competent EBOV and SARS-CoV-2 in Huh7.5 cells. In sum, our results highlight an important role played by SK1/2 in endocytic trafficking, which can be targeted to inhibit entry of late-penetrating viruses and could serve as a starting point for the development of broad-spectrum antiviral therapeutics.
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Affiliation(s)
- Corina M Stewart
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Yuxia Bo
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Kathy Fu
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Mable Chan
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
- Department of Infectious Diseases and Medical Microbiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Robert Kozak
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
| | - Kim Yang-Ping Apperley
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Geneviève Laroche
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Redaet Daniel
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - André M Beauchemin
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Gary Kobinger
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas 77550, United States
| | - Darwyn Kobasa
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
- Department of Infectious Diseases and Medical Microbiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Marceline Côté
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON K1H 8L1, Canada
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6
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Negi V, Kuhn RJ, Fekete DM. Exploring the Expression and Function of cTyro3, a Candidate Zika Virus Receptor, in the Embryonic Chicken Brain and Inner Ear. Viruses 2023; 15:247. [PMID: 36680287 PMCID: PMC9867072 DOI: 10.3390/v15010247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/05/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
The transmembrane protein Axl was proposed as an entry receptor for Zika virus (ZIKV) infection in vitro, but conflicting results from in vivo studies have made it difficult to establish Axl as a physiologically relevant ZIKV receptor. Both the functional redundancy of receptors and the experimental model used can lead to variable results. Therefore, it can be informative to explore alternative animal models to analyze ZIKV receptor candidates as an aid in discovering antivirals. This study used chicken embryos to examine the role of chicken Tyro3 (cTyro3), the equivalent of human Axl. Results show that endogenous cTyro3 mRNA expression overlaps with previously described hot spots of ZIKV infectivity in the brain and inner ear. We asked if ectopic expression or knockdown of cTyro3 influenced ZIKV infection in embryos. Tol2 vectors or replication-competent avian retroviruses were used in ovo to introduce full-length or truncated (presumed dominant-negative) cTyro3, respectively, into the neural tube on embryonic day two (E2). ZIKV was delivered to the brain 24 h later. cTyro3 manipulations did not alter ZIKV infection or cell death in the E5/E6 brain. Moreover, delivery of truncated cTyro3 variants to the E3 otocyst had no effect on inner ear formation on E6 or E10.
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Affiliation(s)
| | | | - Donna M. Fekete
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47906, USA
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7
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Pseudotyped Viruses for Marburgvirus and Ebolavirus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1407:105-132. [PMID: 36920694 DOI: 10.1007/978-981-99-0113-5_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Marburg virus (MARV) and Ebola virus (EBOV) of the Filoviridae family are the most lethal viruses in terms of mortality rate. However, the development of antiviral treatment is hampered by the requirement for biosafety level-4 (BSL-4) containment. The establishment of BSL-2 pseudotyped viruses can provide important tools for the study of filoviruses. This chapter summarizes general information on the filoviruses and then focuses on the construction of replication-deficient pseudotyped MARV and EBOV (e.g., lentivirus system and vesicular stomatitis virus system). It also details the potential applications of the pseudotyped viruses, including neutralization antibody detection, the study of infection mechanisms, the evaluation of antibody-dependent enhancement, virus entry inhibitor screening, and glycoprotein mutation analysis.
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8
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Ye N, Wang B, Feng W, Tang D, Zeng Z. PRRS virus receptors and an alternative pathway for viral invasion. Virus Res 2022; 320:198885. [PMID: 35948131 DOI: 10.1016/j.virusres.2022.198885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/05/2022] [Accepted: 08/06/2022] [Indexed: 11/25/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has a highly restricted cell tropism, which is closely related to the specific receptors associated with PRRSV infection. At least nine cellular molecules have been identified as putative receptors for PRRSV, including CD163, a cysteine-rich scavenger receptor. With the participation of the CD163 receptor and other cofactors, PRRSV invades cells via low pH-dependent clathrin-mediated endocytosis. In addition, PRRSV utilizes viral apoptotic mimicry to infect cells though macropinocytosis as an alternative pathway. In this review, we discuss recent advances in the studies on receptors and pathways that play an important role in PRRSV invasion, and simultaneously explore the use of specific antibodies, small molecules, and blockers targeting receptor-ligand interactions, as a potential strategy for controlling PRRSV infection. Novel antiviral strategies against PRRSV could be developed by identifying the interaction between receptors and ligands.
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Affiliation(s)
- Ni Ye
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Bin Wang
- College of Animal Science, Guizhou University, Guiyang 550025, China.
| | - Wei Feng
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Deyuan Tang
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Zhiyong Zeng
- College of Animal Science, Guizhou University, Guiyang 550025, China
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9
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Walser M, Mayor J, Rothenberger S. Designed Ankyrin Repeat Proteins: A New Class of Viral Entry Inhibitors. Viruses 2022; 14:2242. [PMID: 36298797 PMCID: PMC9611651 DOI: 10.3390/v14102242] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/10/2022] [Accepted: 10/10/2022] [Indexed: 08/08/2023] Open
Abstract
Designed ankyrin repeat proteins (DARPins) are engineered proteins comprising consensus designed ankyrin repeats as scaffold. Tightly packed repeats form a continuous hydrophobic core and a large groove-like solvent-accessible surface that creates a binding surface. DARPin domains recognizing a target of interest with high specificity and affinity can be generated using a synthetic combinatorial library and in vitro selection methods. They can be linked together in a single molecule to build multispecific and multifunctional proteins without affecting expression or function. The modular architecture of DARPins offers unprecedented possibilities of design and opens avenues for innovative antiviral strategies.
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Affiliation(s)
- Marcel Walser
- Molecular Partners AG, Wagistrasse 14, 8952 Zurich-Schlieren, Switzerland
| | - Jennifer Mayor
- Spiez Laboratory, Federal Office for Civil Protection, Austrasse, 3700 Spiez, Switzerland
- Institute of Microbiology, University Hospital Center and University of Lausanne, Rue du Bugnon 48, 1011 Lausanne, Switzerland
| | - Sylvia Rothenberger
- Spiez Laboratory, Federal Office for Civil Protection, Austrasse, 3700 Spiez, Switzerland
- Institute of Microbiology, University Hospital Center and University of Lausanne, Rue du Bugnon 48, 1011 Lausanne, Switzerland
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10
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SARS-CoV-2 hijacks macropinocytosis to facilitate its entry and promote viral spike-mediated cell-to-cell fusion. J Biol Chem 2022; 298:102511. [PMID: 36259516 PMCID: PMC9484108 DOI: 10.1016/j.jbc.2022.102511] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 12/03/2022] Open
Abstract
Revealing the mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry and cell-to-cell spread might provide insights for understanding the underlying mechanisms of viral pathogenesis, tropism, and virulence. The signaling pathways involved in SARS-CoV-2 entry and viral spike–mediated cell-to-cell fusion remain elusive. In the current study, we found that macropinocytosis inhibitors significantly suppressed SARS-CoV-2 infection at both the entry and viral spike–mediated cell-to-cell fusion steps. We demonstrated that SARS-CoV-2 entry required the small GTPase Rac1 and its effector kinase p21-activated kinase 1 by dominant-negative and RNAi assays in human embryonic kidney 293T–angiotensin-converting enzyme 2 cells and that the serine protease transmembrane serine protease 2 reversed the decrease in SARS-CoV-2 entry caused by the macropinocytosis inhibitors. Moreover, in the cell-to-cell fusion assay, we confirmed that macropinocytosis inhibitors significantly decreased viral spike–mediated cell-to-cell fusion. Overall, we provided evidence that SARS-CoV-2 utilizes a macropinocytosis pathway to enter target cells and to efficiently promote viral spike–mediated cell-to-cell fusion.
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11
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Zhang M, Wang X, Hu L, Zhang Y, Zheng H, Wu H, Wang J, Luo L, Xiao H, Qiao C, Li X, Huang W, Wang Y, Feng J, Chen G. TIM-1 Augments Cellular Entry of Ebola Virus Species and Mutants, Which Is Blocked by Recombinant TIM-1 Protein. Microbiol Spectr 2022; 10:e0221221. [PMID: 35384693 PMCID: PMC9241846 DOI: 10.1128/spectrum.02212-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/07/2022] [Indexed: 01/12/2023] Open
Abstract
Ebola virus, a member of the Filoviridae family, utilizes the attachment factors on host cells to support its entry and cause severe tissue damage. TIM-1 has been identified as a predominant attachment factor via interaction with phosphatidylserine (PS) localized on the viral envelope and glycoprotein (GP). In this study, we give the first demonstration that TIM-1 enhances the cellular entry of three species of Ebola virus, as well as those harboring GP mutations (A82V, T544I, and A82V T544I). Furthermore, two TIM-1 variants (i.e., TIM-1-359aa and TIM-1-364aa) had comparable effects on promoting Zaire Ebola virus (EBOV) attachment, internalization, and infection. Importantly, recombinant TIM-1 ectodomain (ECD) protein could decrease the infectivity of Ebola virus and display synergistic inhibitory effects with ADI-15946, a monoclonal antibody with broad neutralizing activity to Ebola virus. Of note, EBOV strains harboring GP mutations (K510E and D552N), which were refractory to antibody treatment, were still sensitive to TIM-1 protein-mediated impairment of infectivity, indicating that TIM-1 protein may represent an alternative therapeutic regimen when antibody evasion occurs. IMPORTANCE The viral genome has acquired numerous mutations with the potential to increase transmission during the 2013-to-2016 outbreak of Ebola virus. EBOV strains harboring GP mutations (A82V, T544I, and A82V T544I), which have been identified to increase viral infectivity in humans, have attracted our attention. Herein, we give the first report that polymorphic TIM-1 enhances the infectivity of three species of Ebola virus, as well as those harboring GP mutations (A82V, T544I, and A82V T544I). We show that recombinant TIM-1 ECD protein could decrease the infectivity of Ebola virus with or without a point mutation and displays synergistic inhibitory effects with ADI-15946. Furthermore, TIM-1 protein potently blocked cell entry of antibody-evading Ebola virus species. These findings highlight the role of TIM-1 in Ebola virus infection and indicate that TIM-1 protein represents a potential therapeutic avenue for Ebola virus and its mutated species.
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Affiliation(s)
- Min Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Xinwei Wang
- Inner Mongolia Key Lab of Molecular Biology, School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, China
| | - Linhan Hu
- Inner Mongolia Key Lab of Molecular Biology, School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, China
| | - Yuting Zhang
- Inner Mongolia Key Lab of Molecular Biology, School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, China
| | - Hang Zheng
- Inner Mongolia Key Lab of Molecular Biology, School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, China
| | - Haiyan Wu
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Jing Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Longlong Luo
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - He Xiao
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Chunxia Qiao
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Xinying Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Weijin Huang
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Youchun Wang
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Jiannan Feng
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
| | - Guojiang Chen
- State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Beijing, China
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12
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Endocytic trafficking of GAS6-AXL complexes is associated with sustained AKT activation. Cell Mol Life Sci 2022; 79:316. [PMID: 35622156 PMCID: PMC9135597 DOI: 10.1007/s00018-022-04312-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 03/27/2022] [Accepted: 04/15/2022] [Indexed: 11/18/2022]
Abstract
AXL, a TAM receptor tyrosine kinase (RTK), and its ligand growth arrest-specific 6 (GAS6) are implicated in cancer metastasis and drug resistance, and cellular entry of viruses. Given this, AXL is an attractive therapeutic target, and its inhibitors are being tested in cancer and COVID-19 clinical trials. Still, astonishingly little is known about intracellular mechanisms that control its function. Here, we characterized endocytosis of AXL, a process known to regulate intracellular functions of RTKs. Consistent with the notion that AXL is a primary receptor for GAS6, its depletion was sufficient to block GAS6 internalization. We discovered that upon receptor ligation, GAS6–AXL complexes were rapidly internalized via several endocytic pathways including both clathrin-mediated and clathrin-independent routes, among the latter the CLIC/GEEC pathway and macropinocytosis. The internalization of AXL was strictly dependent on its kinase activity. In comparison to other RTKs, AXL was endocytosed faster and the majority of the internalized receptor was not degraded but rather recycled via SNX1-positive endosomes. This trafficking pattern coincided with sustained AKT activation upon GAS6 stimulation. Specifically, reduced internalization of GAS6–AXL upon the CLIC/GEEC downregulation intensified, whereas impaired recycling due to depletion of SNX1 and SNX2 attenuated AKT signaling. Altogether, our data uncover the coupling between AXL endocytic trafficking and AKT signaling upon GAS6 stimulation. Moreover, our study provides a rationale for pharmacological inhibition of AXL in antiviral therapy as viruses utilize GAS6–AXL-triggered endocytosis to enter cells.
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13
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Plescia CB, Lindstrom AR, Quintero MV, Keiser P, Anantpadma M, Davey R, Stahelin RV, Davisson VJ. Evaluation of Phenol-Substituted Diphyllin Derivatives as Selective Antagonists for Ebola Virus Entry. ACS Infect Dis 2022; 8:942-957. [PMID: 35357134 PMCID: PMC9112336 DOI: 10.1021/acsinfecdis.1c00474] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Ebola
virus (EBOV) is an aggressive filoviral pathogen that can
induce severe hemorrhagic fever in humans with up to 90% fatality
rate. To date, there are no clinically effective small-molecule drugs
for postexposure therapies to treat filoviral infections. EBOV cellular
entry and infection involve uptake via macropinocytosis, navigation
through the endocytic pathway, and pH-dependent escape into the cytoplasm.
We report the inhibition of EBOV cell entry via selective inhibition
of vacuolar (V)-ATPase by a new series of phenol-substituted derivatives
of the natural product scaffold diphyllin. In cells challenged with
Ebola virus, the diphyllin derivatives inhibit viral entry dependent
upon structural variations to low nanomolar potencies. Mechanistically,
the diphyllin derivatives had no effect on uptake and colocalization
of viral particles with endocytic marker LAMP1 but directly modulated
endosomal pH. The most potent effects were reversible exhibiting higher
selectivity than bafilomycin or the parent diphyllin. Unlike general
lysosomotrophic agents, the diphyllin derivatives showed no major
disruptions of endocytic populations or morphology when examined with
Rab5 and LAMP1 markers. The dilated vacuole phenotype induced by apilimod
treatment or in constitutively active Rab5 mutant Q79L-expressing
cells was both blocked and reversed by the diphyllin derivatives.
The results are consistent with the action of the diphyllin scaffold
as a selective pH-dependent viral entry block in late endosomes. Overall,
the compounds show improved selectivity and minimal cytotoxicity relative
to classical endosomal acidification blocking agents.
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Affiliation(s)
| | | | - Maritza V. Quintero
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio 78229-3900, United States
| | - Patrick Keiser
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts 02118, United States
| | - Manu Anantpadma
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts 02118, United States
| | - Robert Davey
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts 02118, United States
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14
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Gourronc FA, Rebagliati M, Kramer-Riesberg B, Fleck AM, Patten JJ, Geohegan-Barek K, Messingham KN, Davey RA, Maury W, Klingelhutz AJ. Adipocytes are susceptible to Ebola Virus infection. Virology 2022; 573:12-22. [DOI: 10.1016/j.virol.2022.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 12/23/2022]
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15
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Bhattacharyya S. Mechanisms of Immune Evasion by Ebola Virus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1313:15-22. [PMID: 34661889 DOI: 10.1007/978-3-030-67452-6_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
The 2013-2016 Ebola virus epidemic in West Africa, which also spread to the USA, UK and Europe, was the largest reported outbreak till date (World Health Organization. 2016. https://apps.who.int/iris/bitstream/handle/10665/208883/ebolasitrep_10Jun2016_eng.pdf;jsessionid=8B7D74BC9D82D2BE1B110BAFFAD3A6E6?sequence=1 ). The recent Ebola outbreak in the Democratic Republic of the Congo has raised immense global concern on this severe and often fatal infection. Although sporadic, the severity and lethality of Ebola virus disease outbreaks has led to extensive research worldwide on this virus. Vaccine (World Health Organization. 2016. https://www.who.int/en/news-room/detail/23-12-2016-final-trial-results-confirm-ebola-vaccine-provides-high-protection-against-disease ; Henao-Restrepo et al. Lancet 389:505-518, 2017) and drug (Hayden. Nature, 557, 475-476, 2018; Dyall et al. J Infect Dis 218(suppl_5), S672-S678, 2018) development efforts against Ebola virus are research hotspots, and a few approved therapeutics are currently available (Centers for Disease Control and Prevention. 2021. https://www.cdc.gov/vhf/ebola/clinicians/vaccine/index.html; Centers for Disease Control and Prevention. 2021. https://www.cdc.gov/vhf/ebola/treatment/index.html). Ebola virus has evolved several mechanisms of host immune evasion, which facilitate its replication and pathogenesis. This chapter describes the Ebola virus morphology, genome, entry, replication, pathogenesis and viral proteins involved in host immune evasion. Further understanding of the underlying molecular mechanisms of immune evasion may facilitate development of additional novel and sustainable strategies against this deadly virus.
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Affiliation(s)
- Suchita Bhattacharyya
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
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16
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Structural and Functional Aspects of Ebola Virus Proteins. Pathogens 2021; 10:pathogens10101330. [PMID: 34684279 PMCID: PMC8538763 DOI: 10.3390/pathogens10101330] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 01/14/2023] Open
Abstract
Ebola virus (EBOV), member of genus Ebolavirus, family Filoviridae, have a non-segmented, single-stranded RNA that contains seven genes: (a) nucleoprotein (NP), (b) viral protein 35 (VP35), (c) VP40, (d) glycoprotein (GP), (e) VP30, (f) VP24, and (g) RNA polymerase (L). All genes encode for one protein each except GP, producing three pre-proteins due to the transcriptional editing. These pre-proteins are translated into four products, namely: (a) soluble secreted glycoprotein (sGP), (b) Δ-peptide, (c) full-length transmembrane spike glycoprotein (GP), and (d) soluble small secreted glycoprotein (ssGP). Further, shed GP is released from infected cells due to cleavage of GP by tumor necrosis factor α-converting enzyme (TACE). This review presents a detailed discussion on various functional aspects of all EBOV proteins and their residues. An introduction to ebolaviruses and their life cycle is also provided for clarity of the available analysis. We believe that this review will help understand the roles played by different EBOV proteins in the pathogenesis of the disease. It will help in targeting significant protein residues for therapeutic and multi-protein/peptide vaccine development.
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17
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A Naturally Occurring Polymorphism in the Base of Sudan Virus Glycoprotein Decreases Glycoprotein Stability in a Species-Dependent Manner. J Virol 2021; 95:e0107321. [PMID: 34232742 DOI: 10.1128/jvi.01073-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sudan virus (SUDV) is one of five filoviruses that compose the genus Ebolavirus that has been responsible for episodic outbreaks in Central Africa. While the SUDV glycoprotein (GP) structure has been solved, GP residues that affect SUDV entry have not been extensively examined; many of the entry characteristics of SUDV GP are inferred from studies with the Zaire Ebola virus (EBOV) GP. Here, we investigate the effect on virus entry of a naturally occurring polymorphism in SUDV GP. Two of the earliest SUDV isolates contain glutamine at residue 95 (Q95) within the base region of GP1, whereas more recent SUDV isolates and GPs from all other ebolaviruses carry lysine at this position (K95). A K95Q change dramatically decreased titers of pseudovirions bearing SUDV GP, whereas the K95Q substitution in EBOV GP had no effect on titer. We evaluated virus entry to identify SUDV GP Q95-specific entry defects. The presence of Q95 in either EBOV or SUDV GP resulted in enhanced sensitivity of GP to proteolytic processing, yet this could not account for the SUDV-specific decrease in GP Q95 infectivity. We found that SUDV GP Q95 pseudovirions were more sensitive to imipramine, a GP-destabilizing antiviral. In contrast, SUDV GP K95 was more stable, requiring elevated temperatures to inhibit virus infection. Thus, the residue present at GP 95 has a critical role in stabilizing the SUDV glycoprotein, whereas this polymorphism has no effect on EBOV GP stability. These results provide novel insights into filovirus species-specific GP structure that affects virus infectivity. IMPORTANCE Filovirus outbreaks are associated with significant morbidity and mortality. Understanding the structural constraints of filoviral GPs that control virus entry into cells is critical for rational development of novel antivirals to block infection. Here, we identify a naturally occurring glutamine (Q) to lysine (K) polymorphism at residue 95 as a critical determinant of Sudan virus GP stability but not Zaire Ebola virus GP stability. We propose that glutamine at residue 95 in Sudan virus GP mediates decreased virus entry, thereby reducing infectivity. Our findings highlight a unique structural characteristic of Sudan virus GP that affects GP-mediated functionality. Further, it provides a cautionary note for the development of future broad-spectrum filovirus antivirals.
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18
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Ebola virus requires phosphatidylserine scrambling activity for efficient budding and optimal infectivity. J Virol 2021; 95:e0116521. [PMID: 34319156 DOI: 10.1128/jvi.01165-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Ebola virus (EBOV) attaches to target cells using two categories of cell surface receptors, C-type lectins and phosphatidylserine (PS) receptors. PS receptors typically bind to apoptotic cell membrane PS and orchestrate the uptake and clearance of apoptotic debris. Many enveloped viruses also contain exposed PS and can therefore exploit these receptors for cell entry. Viral infection can induce PS externalization in host cells, resulting in increased outer PS levels on budding virions. Scramblase enzymes carry out cellular PS externalization, thus, we targeted these proteins in order to manipulate viral envelope PS levels. We investigated two scramblases previously identified to be involved in EBOV PS levels, transmembrane protein 16F and Xk-related protein 8 (XKR8), as possible mediators of cellular and viral envelope surface PS levels during the replication of recombinant vesicular stomatitis virus containing its native glycoprotein (rVSV/G) or the EBOV glycoprotein (rVSV/EBOV-GP). We found that rVSV/G and rVSV/EBOV-GP virions produced in XKR8 knockout cells contain decreased levels of PS on their surfaces, and the PS-deficient rVSV/EBOV-GP virions are 70% less efficient at infecting cells through PS receptors. We also observed reduced rVSV and EBOV virus-like particle (VLP) budding in ΔXKR8 cells. Deleting XKR8 in HAP1 cells reduced rVSV/G and rVSV/EBOV-GP budding by 60% and 65% respectively, and reduced Ebola VLP budding more than 60%. We further demonstrated that caspase cleavage of XKR8 is required to promote budding. This suggests that XKR8, in addition to mediating virion PS levels, may also be critical for enveloped virus budding at the plasma membrane. Importance Within the last decade, countries in western and central Africa have experienced the most widespread and deadly Ebola outbreaks since the virus was identified in 1976. While outbreaks are primarily attributed to zoonotic transfer events, new evidence is emerging that outbreaks may be caused by a combination of spillover events and viral latency or persistence in survivors. The possibility that Ebola can remain dormant then re-emerge in survivors highlights the critical need to prevent the virus from entering and establishing infection in human cells. Thus far, host-cell scramblases TMEM16F and XKR8 have been implicated in Ebola envelope surface phosphatidylserine (PS) and cell entry using PS receptors. We assessed the contributions of these proteins using CRISPR knockout cells and two EBOV models: rVSV/EBOV-GP and EBOV VLPs. We observed that XKR8 is required for optimal EBOV envelope PS levels and infectivity, and particle budding across all viral models.
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Kirui J, Abidine Y, Lenman A, Islam K, Gwon YD, Lasswitz L, Evander M, Bally M, Gerold G. The Phosphatidylserine Receptor TIM-1 Enhances Authentic Chikungunya Virus Cell Entry. Cells 2021; 10:cells10071828. [PMID: 34359995 PMCID: PMC8303237 DOI: 10.3390/cells10071828] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/12/2021] [Accepted: 07/15/2021] [Indexed: 11/26/2022] Open
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.
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Affiliation(s)
- Jared Kirui
- Centre for Experimental and Clinical Infection Research, TWINCORE, Institute for Experimental Virology, a Joint Venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, 30625 Hannover, Germany; (J.K.); (A.L.); (L.L.)
- Department of Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Yara Abidine
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
- Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, 90185 Umeå, Sweden
| | - Annasara Lenman
- Centre for Experimental and Clinical Infection Research, TWINCORE, Institute for Experimental Virology, a Joint Venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, 30625 Hannover, Germany; (J.K.); (A.L.); (L.L.)
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
| | - Koushikul Islam
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
| | - Yong-Dae Gwon
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
| | - Lisa Lasswitz
- Centre for Experimental and Clinical Infection Research, TWINCORE, Institute for Experimental Virology, a Joint Venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, 30625 Hannover, Germany; (J.K.); (A.L.); (L.L.)
- Department of Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Magnus Evander
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
| | - Marta Bally
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
- Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, 90185 Umeå, Sweden
| | - Gisa Gerold
- Centre for Experimental and Clinical Infection Research, TWINCORE, Institute for Experimental Virology, a Joint Venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, 30625 Hannover, Germany; (J.K.); (A.L.); (L.L.)
- Department of Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hannover, Germany
- Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden; (Y.A.); (K.I.); (Y.-D.G.); (M.E.); (M.B.)
- Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, 90185 Umeå, Sweden
- Correspondence:
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20
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Zdżalik-Bielecka D, Poświata A, Kozik K, Jastrzębski K, Schink KO, Brewińska-Olchowik M, Piwocka K, Stenmark H, Miączyńska M. The GAS6-AXL signaling pathway triggers actin remodeling that drives membrane ruffling, macropinocytosis, and cancer-cell invasion. Proc Natl Acad Sci U S A 2021; 118:e2024596118. [PMID: 34244439 PMCID: PMC8285903 DOI: 10.1073/pnas.2024596118] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AXL, a member of the TAM (TYRO3, AXL, MER) receptor tyrosine kinase family, and its ligand, GAS6, are implicated in oncogenesis and metastasis of many cancer types. However, the exact cellular processes activated by GAS6-AXL remain largely unexplored. Here, we identified an interactome of AXL and revealed its associations with proteins regulating actin dynamics. Consistently, GAS6-mediated AXL activation triggered actin remodeling manifested by peripheral membrane ruffling and circular dorsal ruffles (CDRs). This further promoted macropinocytosis that mediated the internalization of GAS6-AXL complexes and sustained survival of glioblastoma cells grown under glutamine-deprived conditions. GAS6-induced CDRs contributed to focal adhesion turnover, cell spreading, and elongation. Consequently, AXL activation by GAS6 drove invasion of cancer cells in a spheroid model. All these processes required the kinase activity of AXL, but not TYRO3, and downstream activation of PI3K and RAC1. We propose that GAS6-AXL signaling induces multiple actin-driven cytoskeletal rearrangements that contribute to cancer-cell invasion.
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Affiliation(s)
- Daria Zdżalik-Bielecka
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland;
| | - Agata Poświata
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Kamila Kozik
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Kamil Jastrzębski
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Kay Oliver Schink
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, 0379 Oslo, Norway
| | | | - Katarzyna Piwocka
- Laboratory of Cytometry, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - Harald Stenmark
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, 0379 Oslo, Norway
| | - Marta Miączyńska
- Laboratory of Cell Biology, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland;
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21
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Morales A, Rojo Rello S, Cristóbal H, Fiz-López A, Arribas E, Marí M, Tutusaus A, de la Cal-Sabater P, Nicolaes GA, Ortiz-Pérez JT, Bernardo D, García de Frutos P. Growth Arrest-Specific Factor 6 (GAS6) Is Increased in COVID-19 Patients and Predicts Clinical Outcome. Biomedicines 2021; 9:biomedicines9040335. [PMID: 33810394 PMCID: PMC8065652 DOI: 10.3390/biomedicines9040335] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Growth arrest-specific factor 6 (GAS6) and the Tyro3, AXL, and MERTK (TAM) receptors counterbalance pro-inflammatory responses. AXL is a candidate receptor for SARS-CoV-2, particularly in the respiratory system, and the GAS6/AXL axis is targeted in current clinical trials against COVID-19. However, GAS6 and TAMs have not been evaluated in COVID-19 patients at emergency admission. Methods: Plasma GAS6, AXL, and MERTK were analyzed in 132 patients consecutively admitted to the emergency ward during the first peak of COVID-19. Results: GAS6 levels were higher in the SARS-CoV-2-positive patients, increasing progressively with the severity of the disease. Patients with initial GAS6 at the highest quartile had the worst outcome, with a 3-month survival of 65%, compared to a 90% survival for the rest. Soluble AXL exhibited higher plasma concentration in deceased patients, without significant differences in MERTK among SARS-CoV-2-positive groups. GAS6 mRNA was mainly expressed in alveolar cells and AXL in airway macrophages. Remarkably, THP-1 human macrophage differentiation neatly induces AXL, and its inhibition (bemcentinib) reduced cytokine production in human macrophages after LPS challenge. Conclusions: Plasma GAS6 and AXL levels reflect COVID-19 severity and could be early markers of disease prognosis, supporting a relevant role of the GAS6/AXL system in the immune response in COVID-19.
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Affiliation(s)
- Albert Morales
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, 08036 Barcelona, Spain; (A.M.); (H.C.); (M.M.); (A.T.)
- Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit, Hospital Clínic, CIBEREHD, 08036 Barcelona, Spain
| | - Silvia Rojo Rello
- Servicio de Microbiología, Hospital Clínico Universitario de Valladolid, 47003 Valladolid, Spain;
| | - Helena Cristóbal
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, 08036 Barcelona, Spain; (A.M.); (H.C.); (M.M.); (A.T.)
| | - Aida Fiz-López
- Mucosal Immunology Lab, Unidad de Excelencia Instituto de Biomedicina y Genética Molecular (IBGM), Universidad de Valladolid—CSIC, 47003 Valladolid, Spain; (A.F.-L.); (E.A.); (P.d.l.C.-S.); (D.B.)
| | - Elisa Arribas
- Mucosal Immunology Lab, Unidad de Excelencia Instituto de Biomedicina y Genética Molecular (IBGM), Universidad de Valladolid—CSIC, 47003 Valladolid, Spain; (A.F.-L.); (E.A.); (P.d.l.C.-S.); (D.B.)
| | - Montserrat Marí
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, 08036 Barcelona, Spain; (A.M.); (H.C.); (M.M.); (A.T.)
| | - Anna Tutusaus
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, 08036 Barcelona, Spain; (A.M.); (H.C.); (M.M.); (A.T.)
| | - Paloma de la Cal-Sabater
- Mucosal Immunology Lab, Unidad de Excelencia Instituto de Biomedicina y Genética Molecular (IBGM), Universidad de Valladolid—CSIC, 47003 Valladolid, Spain; (A.F.-L.); (E.A.); (P.d.l.C.-S.); (D.B.)
| | - Gerry A.F. Nicolaes
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, 6200 MD Maastricht, The Netherlands;
| | - José T. Ortiz-Pérez
- Clinic Cardiovascular Institute, Hospital Clinic Barcelona, 08036 Barcelona, Spain;
| | - David Bernardo
- Mucosal Immunology Lab, Unidad de Excelencia Instituto de Biomedicina y Genética Molecular (IBGM), Universidad de Valladolid—CSIC, 47003 Valladolid, Spain; (A.F.-L.); (E.A.); (P.d.l.C.-S.); (D.B.)
- Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 28029 Madrid, Spain
| | - Pablo García de Frutos
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, 08036 Barcelona, Spain; (A.M.); (H.C.); (M.M.); (A.T.)
- Centro de Investigación Biomédica en Red Sobre Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Department of Cell Death and Differentiation, Institut d’Investigacions Biomèdiques de Barcelona, IIBB-CSIC, Rosselló 161, 6th Floor, 08036 Barcelona, Spain
- Correspondence:
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22
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Misasi J, Sullivan NJ. Immunotherapeutic strategies to target vulnerabilities in the Ebolavirus glycoprotein. Immunity 2021; 54:412-436. [PMID: 33691133 DOI: 10.1016/j.immuni.2021.01.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 01/15/2021] [Accepted: 01/20/2021] [Indexed: 12/18/2022]
Abstract
The 2014 Ebola virus disease (EVD) outbreak in West Africa and the subsequent outbreaks of 2018-2020 in Equator and North Kivu provinces of the Democratic Republic of the Congo illustrate the public health challenges of emerging and reemerging viruses. EVD has a high case fatality rate with a rapidly progressing syndrome of fever, rash, vomiting, diarrhea, and bleeding diathesis. Recently, two monoclonal-antibody-based therapies received United States Food and Drug Administration (FDA) approval, and there are several other passive immunotherapies that hold promise as therapeutics against other species of Ebolavirus. Here, we review concepts needed to understand mechanisms of action, present an expanded schema to define additional sites of vulnerability on the viral glycoprotein, and review current antibody-based therapeutics. The concepts described are used to gain insights into the key characteristics that represent functional targets for immunotherapies against Zaire Ebolavirus and other emerging viruses within the Ebolavirus genus.
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Affiliation(s)
- John Misasi
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Vaccine Research Center, 40 Convent Drive, Bethesda, MD 20892, USA
| | - Nancy J Sullivan
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Vaccine Research Center, 40 Convent Drive, Bethesda, MD 20892, USA.
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23
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Lay Mendoza MF, Acciani MD, Levit CN, Santa Maria C, Brindley MA. Monitoring Viral Entry in Real-Time Using a Luciferase Recombinant Vesicular Stomatitis Virus Producing SARS-CoV-2, EBOV, LASV, CHIKV, and VSV Glycoproteins. Viruses 2020; 12:E1457. [PMID: 33348746 PMCID: PMC7766484 DOI: 10.3390/v12121457] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/11/2020] [Accepted: 12/15/2020] [Indexed: 01/06/2023] Open
Abstract
Viral entry is the first stage in the virus replication cycle and, for enveloped viruses, is mediated by virally encoded glycoproteins. Viral glycoproteins have different receptor affinities and triggering mechanisms. We employed vesicular stomatitis virus (VSV), a BSL-2 enveloped virus that can incorporate non-native glycoproteins, to examine the entry efficiencies of diverse viral glycoproteins. To compare the glycoprotein-mediated entry efficiencies of VSV glycoprotein (G), Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S), Ebola (EBOV) glycoprotein (GP), Lassa (LASV) GP, and Chikungunya (CHIKV) envelope (E) protein, we produced recombinant VSV (rVSV) viruses that produce the five glycoproteins. The rVSV virions encoded a nano luciferase (NLucP) reporter gene fused to a destabilization domain (PEST), which we used in combination with the live-cell substrate EndurazineTM to monitor viral entry kinetics in real time. Our data indicate that rVSV particles with glycoproteins that require more post-internalization priming typically demonstrate delayed entry in comparison to VSV G. In addition to determining the time required for each virus to complete entry, we also used our system to evaluate viral cell surface receptor preferences, monitor fusion, and elucidate endocytosis mechanisms. This system can be rapidly employed to examine diverse viral glycoproteins and their entry requirements.
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Affiliation(s)
- Maria Fernanda Lay Mendoza
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (M.F.L.M.); (M.D.A.); (C.N.L.); (C.S.M.)
| | - Marissa Danielle Acciani
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (M.F.L.M.); (M.D.A.); (C.N.L.); (C.S.M.)
| | - Courtney Nina Levit
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (M.F.L.M.); (M.D.A.); (C.N.L.); (C.S.M.)
| | - Christopher Santa Maria
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (M.F.L.M.); (M.D.A.); (C.N.L.); (C.S.M.)
| | - Melinda Ann Brindley
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (M.F.L.M.); (M.D.A.); (C.N.L.); (C.S.M.)
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
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Kuroda M, Halfmann P, Kawaoka Y. HER2-mediated enhancement of Ebola virus entry. PLoS Pathog 2020; 16:e1008900. [PMID: 33052961 PMCID: PMC7556532 DOI: 10.1371/journal.ppat.1008900] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/17/2020] [Indexed: 11/29/2022] Open
Abstract
Multiple cell surface molecules including TAM receptors (TYRO3, AXL, and MERTK), a family of tyrosine kinase receptors, can serve as attachment receptors for Ebola virus (EBOV) entry into cells. The interaction of these receptors with EBOV particles is believed to trigger the initial internalization events that lead to macropinocytosis. However, the details of how these interactions lead to EBOV internalization have yet to be elucidated. Here, we screened receptor tyrosine kinase (RTK) inhibitors for anti-EBOV activity by using our previously established biologically contained Ebola virus that lacks the VP30 gene (EBOVΔVP30) and identified several RTKs, including human epidermal growth factor receptor 2 (HER2), as potential targets of anti-EBOV inhibitors and as novel host factors that have a role in EBOV infection. Of these identified RTKs, it was only HER2 whose knockdown by siRNAs impaired EBOVΔVP30-induced AKT1 phosphorylation, an event that is required for AKT1 activation and subsequent macropinocytosis. Stable expression of HER2 resulted in constitutive activation of AKT1, resulting in the enhancement of EBOVΔVP30 growth, EBOV GP-mediated entry, and macropinocytosis. Moreover, we found that HER2 interacts with the TAM receptors, and in particular forms a complex with TYRO3 and EBOVΔVP30 particles on the cell surface. Interestingly, HER2 was required for EBOVΔVP30-induced TYRO3 and AKT1 activation, but the other TAM receptors (TYRO3 and MERTK) were not essential for EBOVΔVP30-induced HER2 and AKT1 activation. Our findings demonstrate that HER2 plays an important role in EBOV entry and provide novel insights for the development of therapeutics against the virus.
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Affiliation(s)
- Makoto Kuroda
- Department of Pathobiological Sciences, School of Veterinary Medicine, Influenza Research Institute, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Peter Halfmann
- Department of Pathobiological Sciences, School of Veterinary Medicine, Influenza Research Institute, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Yoshihiro Kawaoka
- Department of Pathobiological Sciences, School of Veterinary Medicine, Influenza Research Institute, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- Department of Microbiology and Immunology, Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Special Pathogens, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
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Kim JH, Koh B, Ahn DG, Lee SJ, Park TJ, Park JP. A screening study of high affinity peptide as molecular binder for AXL, tyrosine kinase receptor involving in Zika virus entry. Bioelectrochemistry 2020; 137:107670. [PMID: 32971483 DOI: 10.1016/j.bioelechem.2020.107670] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 11/24/2022]
Abstract
The recent extensive spread of Zika virus has led to increased interest in the development of early diagnostic tests. To the best of our knowledge, this is the first study to demonstrate the successful use of phage display to identify affinity peptides for quantitative analysis of AXL, a tyrosine kinase receptor involved in Zika virus entry. Biopanning of M13 phage library successfully identified a high affinity peptide, with the sequence AHNHTPIKQKYL. To study the feasibility of using free peptides for molecular recognition, we synthesized a series of amino acid-substituted peptides and examined their binding affinity for AXL using electrochemical impedance spectroscopy and square wave voltammetry. Most synthetic peptides had non-identical random coil structures based on circular dichroism spectroscopy. Of the peptides tested, AXL BP1 exhibited nanomolar binding affinity for AXL. To verify whether AXL BP1 could be used as a peptide inhibitor at the cellular level, two functional tests were carried out: a WST assay for cell viability and qRT-PCR for quantification of RNA levels in Zika virus-infected Huh7 cells. The results showed that AXL BP1 had low cytotoxicity and could block Zika virus entry. These results indicate that newly identified affinity peptides could potentially be used for the development of Zika virus entry inhibitors.
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Affiliation(s)
- Ji Hong Kim
- Department of Food Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Byumseok Koh
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Dae-Gyun Ahn
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Yuseong-gu, Daejeon 34114, Republic of Korea
| | - Sei-Jung Lee
- Department of Pharmaceutical Engineering, Daegu Haany University, Gyeongsan 38610, Republic of Korea
| | - Tae Jung Park
- Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
| | - Jong Pil Park
- Department of Food Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea.
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Axl Deficiency Promotes the Neuroinvasion of Japanese Encephalitis Virus by Enhancing IL-1α Production from Pyroptotic Macrophages. J Virol 2020; 94:JVI.00602-20. [PMID: 32611752 PMCID: PMC7431807 DOI: 10.1128/jvi.00602-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/20/2020] [Indexed: 12/12/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes Japanese encephalitis (JE), the most commonly diagnosed viral encephalitis worldwide. The fatality rate of JE is 20%, and nearly half of the surviving patients develop neuropsychiatric sequelae. Axl is a receptor tyrosine kinase that plays multiple roles in flaviviral infections. Currently, the involvement of Axl in JEV infection remains enigmatic. In this study, we demonstrate that Axl impedes the pathogenesis of severe JE in mice by maintaining blood-brain-barrier (BBB) integrity and restricting viral neuroinvasion. Furthermore, serum IL-1α is a key mediator of this process and is primarily released by JEV-infected pyroptotic macrophages to elicit BBB breakdown, while an IL-1α antagonist can effectively reduce the incidence of severe JE. Our work uncovers the protective role of Axl in antagonizing severe JE and shows that the use of an IL-1α antagonist may be a promising tactic to prevent severe JE. Japanese encephalitis virus (JEV) is a flavivirus that causes Japanese encephalitis (JE), which has an unclear pathogenesis. Despite vaccination, thousands of deaths attributed to JE are reported annually. In this study, we report that mice deficient for Axl, a receptor tyrosine kinase that plays multiple roles in flaviviral infection, displayed greater mortality upon JEV infection. The effect of Axl deficiency on JEV infection was mediated by markedly elevated serum interleukin-1α (IL-1α) levels, which devastated the blood-brain-barrier and promoted viral neuroinvasion within 24 h postinfection. Using an in situ infection model, we showed that dead macrophages were the primary source of observed increased serum IL-1α levels. Axl deficiency enhanced cell death and caused pyroptosis in 80% of JEV-infected macrophages by disrupting phosphatidylinositol 3-kinase (PI3K)-Akt signaling. Intriguingly, the primary effector released by pyroptotic macrophages in our model was IL-1α rather than IL-1β. Finally, we assessed the effect of an IL-1α antagonist and demonstrated that it effectively prevented the incidence of JE. Our results indicate that Axl plays a protective role in JEV infection, identify IL-1α released by pyroptotic macrophages as a crucial factor promoting JEV neuroinvasion, and suggest that an IL-1α antagonist may be a candidate for JE therapy. IMPORTANCE Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes Japanese encephalitis (JE), the most commonly diagnosed viral encephalitis worldwide. The fatality rate of JE is 20%, and nearly half of the surviving patients develop neuropsychiatric sequelae. Axl is a receptor tyrosine kinase that plays multiple roles in flaviviral infections. Currently, the involvement of Axl in JEV infection remains enigmatic. In this study, we demonstrate that Axl impedes the pathogenesis of severe JE in mice by maintaining blood-brain-barrier (BBB) integrity and restricting viral neuroinvasion. Furthermore, serum IL-1α is a key mediator of this process and is primarily released by JEV-infected pyroptotic macrophages to elicit BBB breakdown, while an IL-1α antagonist can effectively reduce the incidence of severe JE. Our work uncovers the protective role of Axl in antagonizing severe JE and shows that the use of an IL-1α antagonist may be a promising tactic to prevent severe JE.
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The Role of Receptor Tyrosine Kinases in Lassa Virus Cell Entry. Viruses 2020; 12:v12080857. [PMID: 32781509 PMCID: PMC7472032 DOI: 10.3390/v12080857] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/31/2020] [Accepted: 08/02/2020] [Indexed: 02/06/2023] Open
Abstract
The zoonotic Old World mammarenavirus Lassa (LASV) causes severe hemorrhagic fever with high mortality and morbidity in humans in endemic regions. The development of effective strategies to combat LASV infections is of high priority, given the lack of a licensed vaccine and restriction on available treatment to off-label use of ribavirin. A better understanding of the fundamental aspects of the virus's life cycle would help to improve the development of novel therapeutic approaches. Host cell entry and restriction factors represent major barriers for emerging viruses and are promising targets for therapeutic intervention. In addition to the LASV main receptor, the extracellular matrix molecule dystroglycan (DG), the phosphatidylserine-binding receptors of the Tyro3/Axl/Mer (TAM), and T cell immunoglobulin and mucin receptor (TIM) families are potential alternative receptors of LASV infection. Therefore, the relative contributions of candidate receptors to LASV entry into a particular human cell type are a complex function of receptor expression and functional DG availability. Here, we describe the role of two receptor tyrosine kinases (RTKs), Axl and hepatocyte growth factor receptor (HGFR), in the presence and absence of glycosylated DG for LASV entry. We found that both RTKs participated in the macropinocytosis-related LASV entry and, regardless of the presence or absence of functional DG, their inhibition resulted in a significant antiviral effect.
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The Multifaceted Roles of TAM Receptors during Viral Infection. Virol Sin 2020; 36:1-12. [PMID: 32720213 DOI: 10.1007/s12250-020-00264-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/08/2020] [Indexed: 12/13/2022] Open
Abstract
Tyro3, Axl, and Mertk (TAM) receptors play multiple roles in a myriad of physiological and pathological processes, varying from promoting the phagocytic clearance of apoptotic cells, sustaining the immune and inflammatory homeostasis, maintaining the blood-brain barrier (BBB) integrity and central nervous system (CNS) homeostasis, to mediating cancer malignancy and chemoresistance. Growth arrest-specific protein 6 (Gas6) and protein S (Pros1) are the two ligands that activate TAM receptors. Recently, TAM receptors have been reported to mediate cell entry and infection of multitudinous enveloped viruses in a manner called apoptotic mimicry. Moreover, TAM receptors are revitalized during viral entry and infection, which sequesters innate immune and inflammatory responses, facilitating viral replication and immune evasion. However, accumulating evidence have now proposed that TAM receptors are not required for the infection of these viruses in vivo. In addition, TAM receptors protect mice against the CNS infection of neuroinvasive viruses and relieve the brain lesions during encephalitis. These protective effects are achieved through maintaining BBB integrity, attenuating proinflammatory cytokine production, and promoting neural cell survival. TAM receptors also regulate the programmed cell death modes of virus-infected cells, which have profound impacts on the pathogenesis and outcome of infection. Here, we systematically review the functionalities and underlying mechanisms of TAM receptors and propose the potential application of TAM agonists to prevent severe viral encephalitis.
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Zheng G, Li LF, Zhang Y, Qu L, Wang W, Li M, Yu S, Zhou M, Luo Y, Sun Y, Munir M, Li S, Qiu HJ. MERTK is a host factor that promotes classical swine fever virus entry and antagonizes innate immune response in PK-15 cells. Emerg Microbes Infect 2020; 9:571-581. [PMID: 32172658 PMCID: PMC7144274 DOI: 10.1080/22221751.2020.1738278] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Classical swine fever virus (CSFV) is a member of the genus Pestivirus in the Flaviviridae family. To date, the host factors required for CSFV entry remain poorly characterized. To identify the functional membrane protein(s) involved in CSFV infection, we analyzed the transcriptomic data from previous studies describing gene expression profiles for CSFV, and found twelve novel candidate proteins. One of these proteins, MERTK, significantly reduced CSFV protein expression by RNA interference screening using a recombinant CSFV that contains a luciferase reporter to measure CSFV protein expression. Furthermore, our results demonstrated that either anti-MERTK antibodies or soluble MERTK ectodomain could reduce CSFV infection in PK-15 cells in a dose-dependent manner. Mechanistically, MERTK interacted with the E2 protein of CSFV and facilitated virus entry. After virus entry, MERTK downregulates of mRNA expression of IFN-β and promotes CSFV infection. Interestingly, the soluble MERTK ectodomain could also reduce the infection of bovine viral diarrhea virus (BVDV), another pestivirus. Taken together, our results suggested that MERTK is a CSFV entry factor that synergistically dampens innate immune responses in PK-15 cells and is also involved in BVDV infection.
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Affiliation(s)
- Guanglai Zheng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Lian-Feng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Yuexiu Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Liang Qu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Wenjing Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Miao Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Shaoxiong Yu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Mo Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Muhammad Munir
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, United Kingdom
| | - Su Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
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Jin C, Che B, Guo Z, Li C, Liu Y, Wu W, Wang S, Li D, Cui Z, Liang M. Single virus tracking of Ebola virus entry through lipid rafts in living host cells. BIOSAFETY AND HEALTH 2020; 2:25-31. [PMID: 32835208 PMCID: PMC7347359 DOI: 10.1016/j.bsheal.2019.12.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/24/2019] [Accepted: 12/25/2019] [Indexed: 12/20/2022] Open
Abstract
Ebola virus (EBOV) is one of the most pathogenic viruses in humans which can cause a lethal hemorrhagic fever. Understanding the cellular entry mechanisms of EBOV can promote the development of new therapeutic strategies to control virus replication and spread. It has been known that EBOV virions bind to factors expressed at the host cell surface. Subsequently, the virions are internalized by a macropinocytosis-like process, followed by being trafficked through early and late endosomes. Recent researches indicate that the entry of EBOV into cells requires integrated and functional lipid rafts. Whilst lipid rafts have been hypothesized to play a role in virus entry, there is a current lack of supporting data. One major technical hurdle is the lack of effective approaches for observing viral entry. To provide evidence on the involvement of lipid rafts in the entry process of EBOV, we generated the fluorescently labeled Ebola virus like particles (VLPs), and utilized single-particle tracking (SPT) to visualize the entry of fluorescent Ebola VLPs in live cells and the interaction of Ebola VLPs with lipid rafts. In this study, we demonstrate the compartmentalization of Ebola VLPs in lipid rafts during entry process, and inform the essential function of lipid rafts for the entry of Ebola virus. As such, our study provides evidence to show that the raft integrity is critical for Ebola virus pathogenesis and that lipid rafts can serve as potential targets for the development of novel therapeutic strategies.
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Affiliation(s)
- Cong Jin
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
- National Center for AIDS/STD Control and Prevention, China CDC, Beijing 102206, China
| | - Bin Che
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
| | - Zhengyuan Guo
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chuan Li
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
| | - Yang Liu
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
| | - Wei Wu
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
| | - Shiwen Wang
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
| | - Dexin Li
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
| | - Zongqiang Cui
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mifang Liang
- Key Laboratory of Medical Virology and Viral Diseases, Ministry of Health of People's Republic of China, National Institute for Viral Disease Control and Prevention (IVDC), Chinese Center for Disease control and Prevention (China CDC), Beijing 102206, China
- Center for Biosafety Mega-Science, Chinese Academy of Sciences, Beijing 100049, China
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Mayor J, Torriani G, Rothenberger S, Engler O. T-cell immunoglobulin and mucin (TIM) contributes to the infection of human airway epithelial cells by pseudotype viruses containing Hantaan virus glycoproteins. Virology 2020; 543:54-62. [PMID: 32056847 DOI: 10.1016/j.virol.2020.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 12/24/2022]
Abstract
Hantaviruses are rodent-borne hemorrhagic fever viruses leading to serious diseases. Viral attachment and entry represent the first steps in virus transmission and are promising targets for antiviral therapeutic intervention. Here we investigated receptor use in human airway epithelium of the Old and New World hantaviruses Hantaan virus (HTNV) and Andes virus (ANDV). Using a biocontained recombinant vesicular stomatitis virus pseudotype platform, we provide first evidence for a role of the cellular phosphatidylserine (PS) receptors of the T-cell immunoglobulin and mucin (TIM) protein family in HTNV and ANDV infection. In line with previous studies, HTNV, but not ANDV, was able to use glycosaminoglycan heparan sulfate and αvβ3 integrin as co-receptors. In sum, our studies demonstrate for the first time that hantaviruses make use of apoptotic mimicry for infection of human airway epithelium, which may explain why these viruses can easily break the species barrier.
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Affiliation(s)
- Jennifer Mayor
- Institute of Microbiology, University Hospital Center and University of Lausanne, Rue du Bugnon 48, CH-1011, Lausanne, Switzerland; Spiez Laboratory, CH-3700, Spiez, Switzerland
| | - Giulia Torriani
- Institute of Microbiology, University Hospital Center and University of Lausanne, Rue du Bugnon 48, CH-1011, Lausanne, Switzerland
| | - Sylvia Rothenberger
- Institute of Microbiology, University Hospital Center and University of Lausanne, Rue du Bugnon 48, CH-1011, Lausanne, Switzerland; Spiez Laboratory, CH-3700, Spiez, Switzerland.
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Cagigi A, Misasi J, Ploquin A, Stanley DA, Ambrozak D, Tsybovsky Y, Mason RD, Roederer M, Sullivan NJ. Vaccine Generation of Protective Ebola Antibodies and Identification of Conserved B-Cell Signatures. J Infect Dis 2019; 218:S528-S536. [PMID: 30010811 DOI: 10.1093/infdis/jiy333] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We recently identified a single potently neutralizing monoclonal antibody (mAb), mAb114, isolated from a human survivor of natural Zaire ebolavirus (EBOV) infection, which fully protects nonhuman primates (NHPs) against lethal EBOV challenge. To evaluate the ability of vaccination to generate mAbs such as mAb114, we cloned antibodies from NHPs vaccinated with vectors encoding the EBOV glycoprotein (GP). We identified 14 unique mAbs with potent binding to GP, 4 of which were neutralized and had the functional characteristics of mAb114. These vaccine-induced macaque mAbs share many sequence similarities with mAb114 and use the same mAb114 VH gene (ie, IGHV3-13) when classified using the macaque IMGT database. The antigen-specific VH-gene repertoire present after each immunization indicated that IGHV3-13 mAbs populate an EBOV-specific B-cell repertoire that appears to become more prominent with subsequent boosting. These findings will support structure-based vaccine design aimed at enhanced induction of antibodies such as mAb114.
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Affiliation(s)
- Alberto Cagigi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - John Misasi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.,Division of Infectious Diseases, Boston Children's Hospital, Massachusetts
| | - Aurélie Ploquin
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Daphne A Stanley
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - David Ambrozak
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Yaroslav Tsybovsky
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Maryland
| | - Rosemarie D Mason
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Mario Roederer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Nancy J Sullivan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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Characterization of the Filovirus-Resistant Cell Line SH-SY5Y Reveals Redundant Role of Cell Surface Entry Factors. Viruses 2019; 11:v11030275. [PMID: 30893855 PMCID: PMC6466046 DOI: 10.3390/v11030275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 03/14/2019] [Accepted: 03/15/2019] [Indexed: 12/31/2022] Open
Abstract
Filoviruses infect a wide range of cell types with the exception of lymphocytes. The intracellular proteins cathepsin B and L, two-pore channel 1 and 2, and bona fide receptor Niemann–Pick Disease C1 (NPC1) are essential for the endosomal phase of cell entry. However, earlier steps of filoviral infection remain poorly characterized. Numerous plasma membrane proteins have been implicated in attachment but it is still unclear which ones are sufficient for productive entry. To define a minimal set of host factors required for filoviral glycoprotein-driven cell entry, we screened twelve cell lines and identified the nonlymphocytic cell line SH-SY5Y to be specifically resistant to filovirus infection. Heterokaryons of SH-SY5Y cells fused to susceptible cells were susceptible to filoviruses, indicating that SH-SY5Y cells do not express a restriction factor but lack an enabling factor critical for filovirus entry. However, all tested cell lines expressed functional intracellular factors. Global gene expression profiling of known cell surface entry factors and protein expression levels of analyzed attachment factors did not reveal any correlation between susceptibility and expression of a specific host factor. Using binding assays with recombinant filovirus glycoprotein, we identified cell attachment as the step impaired in filovirus entry in SH-SY5Y cells. Individual overexpression of attachment factors T-cell immunoglobulin and mucin domain 1 (TIM-1), Axl, Mer, or dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) rendered SH-SY5Y cells susceptible to filovirus glycoprotein-driven transduction. Our study reveals that a lack of attachment factors limits filovirus entry and provides direct experimental support for a model of filoviral cell attachment where host factor usage at the cell surface is highly promiscuous.
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Salata C, Calistri A, Alvisi G, Celestino M, Parolin C, Palù G. Ebola Virus Entry: From Molecular Characterization to Drug Discovery. Viruses 2019; 11:v11030274. [PMID: 30893774 PMCID: PMC6466262 DOI: 10.3390/v11030274] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/15/2019] [Accepted: 03/16/2019] [Indexed: 02/06/2023] Open
Abstract
Ebola Virus Disease (EVD) is one of the most lethal transmissible infections, characterized by a high fatality rate, and caused by a member of the Filoviridae family. The recent large outbreak of EVD in Western Africa (2013–2016) highlighted the worldwide threat represented by the disease and its impact on global public health and the economy. The development of highly needed anti-Ebola virus antivirals has been so far hampered by the shortage of tools to study their life cycle in vitro, allowing to screen for potential active compounds outside a biosafety level-4 (BSL-4) containment. Importantly, the development of surrogate models to study Ebola virus entry in a BSL-2 setting, such as viral pseudotypes and Ebola virus-like particles, tremendously boosted both our knowledge of the viral life cycle and the identification of promising antiviral compounds interfering with viral entry. In this context, the combination of such surrogate systems with large-scale small molecule compounds and haploid genetic screenings, as well as rational drug design and drug repurposing approaches will prove priceless in our quest for the development of a treatment for EVD.
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Affiliation(s)
- Cristiano Salata
- Department of Molecular Medicine, University of Padova, IT-35121 Padova, Italy.
| | - Arianna Calistri
- Department of Molecular Medicine, University of Padova, IT-35121 Padova, Italy.
| | - Gualtiero Alvisi
- Department of Molecular Medicine, University of Padova, IT-35121 Padova, Italy.
| | - Michele Celestino
- Department of Molecular Medicine, University of Padova, IT-35121 Padova, Italy.
| | - Cristina Parolin
- Department of Molecular Medicine, University of Padova, IT-35121 Padova, Italy.
| | - Giorgio Palù
- Department of Molecular Medicine, University of Padova, IT-35121 Padova, Italy.
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Shaikh F, Zhao Y, Alvarez L, Iliopoulou M, Lohans C, Schofield CJ, Padilla-Parra S, Siu SWI, Fry EE, Ren J, Stuart DI. Structure-Based in Silico Screening Identifies a Potent Ebolavirus Inhibitor from a Traditional Chinese Medicine Library. J Med Chem 2019; 62:2928-2937. [PMID: 30785281 PMCID: PMC6441942 DOI: 10.1021/acs.jmedchem.8b01328] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
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Potent Ebolavirus (EBOV) inhibitors
will help to curtail outbreaks
such as that which occurred in 2014–16 in West Africa. EBOV
has on its surface a single glycoprotein (GP) critical for viral entry
and membrane fusion. Recent high-resolution complexes of EBOV GP with
a variety of approved drugs revealed that binding to a common cavity
prevented fusion of the virus and endosomal membranes, inhibiting
virus infection. We performed docking experiments, screening a database
of natural compounds to identify those likely to bind at this site.
Using both inhibition assays of HIV-1-derived pseudovirus cell entry
and structural analyses of the complexes of the compounds with GP,
we show here that two of these compounds attach in the common binding
cavity, out of eight tested. In both cases, two molecules bind in
the cavity. The two compounds are chemically similar, but the tighter
binder has an additional chlorine atom that forms good halogen bonds
to the protein and achieves an IC50 of 50 nM, making it
the most potent GP-binding EBOV inhibitor yet identified, validating
our screening approach for the discovery of novel antiviral compounds.
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Affiliation(s)
- Faraz Shaikh
- Department of Computer and Information Science, Faculty of Science and Technology , University of Macau , E11, Macau 999078 , China.,Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K
| | - Yuguang Zhao
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K
| | - Luis Alvarez
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K
| | - Maria Iliopoulou
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K
| | - Christopher Lohans
- Department of Chemistry , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | | | - Sergi Padilla-Parra
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K.,Biocruces-Bizkaia Health Research Institute , Ikerbasque, Basque Foundation for Science , Bilbao 48011 , Spain
| | - Shirley W I Siu
- Department of Computer and Information Science, Faculty of Science and Technology , University of Macau , E11, Macau 999078 , China
| | - Elizabeth E Fry
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K
| | - Jingshan Ren
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K
| | - David I Stuart
- Division of Structural Biology , University of Oxford , The Henry Wellcome Building for Genomic Medicine , Headington, Oxford OX3 7BN , U.K.,Diamond Light Source Limited , Harwell Science & Innovation Campus , Didcot OX11 0DE , U.K
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A Diacylglycerol Kinase Inhibitor, R-59-022, Blocks Filovirus Internalization in Host Cells. Viruses 2019; 11:v11030206. [PMID: 30832223 PMCID: PMC6466206 DOI: 10.3390/v11030206] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 01/21/2023] Open
Abstract
Filoviruses, such as Ebola virus (EBOV) and Marburg virus, are causative agents of unpredictable outbreaks of severe hemorrhagic fevers in humans and non-human primates. For infection, filoviral particles need to be internalized and delivered to intracellular vesicles containing cathepsin proteases and the viral receptor Niemann-Pick C1. Previous studies have shown that EBOV triggers macropinocytosis of the viral particles in a glycoprotein (GP)-dependent manner, but the molecular events required for filovirus internalization remain mostly unknown. Here we report that the diacylglycerol kinase inhibitor, R-59-022, blocks EBOV GP-mediated entry into Vero cells and bone marrow-derived macrophages. Investigation of the mode of action of the inhibitor revealed that it blocked an early step in entry, more specifically, the internalization of the viral particles via macropinocytosis. Finally, R-59-022 blocked viral entry mediated by a panel of pathogenic filovirus GPs and inhibited growth of replicative Ebola virus. Taken together, our studies suggest that R-59-022 could be used as a tool to investigate macropinocytic uptake of filoviruses and could be a starting point for the development of pan-filoviral therapeutics.
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Nanbo A, Kawaoka Y. Molecular Mechanism of Externalization of Phosphatidylserine on the Surface of Ebola Virus Particles. DNA Cell Biol 2019; 38:115-120. [PMID: 30615471 DOI: 10.1089/dna.2018.4485] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Ebola virus (EBOV) is an enveloped filamentous virus that causes severe hemorrhagic fever in humans and nonhuman primates with up to 90% fatality. Accumulating evidence indicates that various viruses, including EBOV, exploit the host apoptotic clearance machinery to enhance their entry into host cells by externalizing phosphatidylserine (PS) in the viral envelope. PS is typically distributed in the inner layer of the plasma membrane (PM) in normal cells. Progeny EBOV virions bud from the PM of infected cells, suggesting that PS is likely flipped to the outer leaflet of the envelope of Ebola virions. Currently, the intracellular dynamics of PS during EBOV infection are poorly understood. This review summarizes recent progress in determining the molecular mechanism of externalization of PS in the envelope of EBOV particles. We also discuss future directions and how viral apoptotic mimicry could be targeted for therapeutics.
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Affiliation(s)
- Asuka Nanbo
- 1 Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yoshihiro Kawaoka
- 2 Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.,3 Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin.,4 Department of Special Pathogens, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
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38
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Halder AK, Dutta P, Kundu M, Basu S, Nasipuri M. Review of computational methods for virus-host protein interaction prediction: a case study on novel Ebola-human interactions. Brief Funct Genomics 2018; 17:381-391. [PMID: 29028879 PMCID: PMC7109800 DOI: 10.1093/bfgp/elx026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Identification of potential virus-host interactions is useful and vital to control the highly infectious virus-caused diseases. This may contribute toward development of new drugs to treat the viral infections. Recently, database records of clinically and experimentally validated interactions between a small set of human proteins and Ebola virus (EBOV) have been published. Using the information of the known human interaction partners of EBOV, our main objective is to identify a set of proteins that may interact with EBOV proteins. Here, we first review the state-of-the-art, computational methods used for prediction of novel virus-host interactions for infectious diseases followed by a case study on EBOV-human interactions. The assessment result shows that the predicted human host proteins are highly similar with known human interaction partners of EBOV in the context of structure and semantics and are responsible for similar biochemical activities, pathways and host-pathogen relationships.
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Affiliation(s)
- Anup Kumar Halder
- Department of Computer Science and Engineering, Jadavpur University, India
| | - Pritha Dutta
- Department of Computer Science and Engineering, Jadavpur University, India
| | - Mahantapas Kundu
- Department of Computer Science and Engineering, Jadavpur University, India
| | - Subhadip Basu
- Department of Computer Science and Engineering, Jadavpur University, India
| | - Mita Nasipuri
- Department of Computer Science and Engineering, Jadavpur University, India
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39
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Forrester JV. Ebola virus and persistent chronic infection: when does replication cease? ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:S39. [PMID: 30613614 DOI: 10.21037/atm.2018.09.60] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- John V Forrester
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.,Lions Eye Institute, University of Western Australia, Perth, Western Australia, Australia
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40
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Du W, Brekken RA. Does Axl have potential as a therapeutic target in pancreatic cancer? Expert Opin Ther Targets 2018; 22:955-966. [PMID: 30244621 PMCID: PMC6292430 DOI: 10.1080/14728222.2018.1527315] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Pancreatic cancer is a leading cause of cancer-related death. Metastasis, therapy resistance, and immunosuppression are dominant characteristics of pancreatic tumors. Strategies that enhance the efficacy of standard of care and/or immune therapy are likely the most efficient route to improve overall survival in this disease. Areas covered: Axl, a member of the TAM (Tyro3, Axl, MerTK) family of receptor tyrosine kinases, is involved in cell plasticity, chemoresistance, immune suppression, and metastasis in various cancers, including pancreatic cancer. This review provides an overview of Axl and its function in normal conditions, summarizes the regulation and function of Axl in cancer, and highlights the contribution of Axl to pancreatic cancer as well as its potential as a therapeutic target. Expert opinion: Axl is an attractive therapeutic target in pancreatic cancer because it contributes to many of the roadblocks that hamper therapeutic efficacy. Clinical evidence supporting Axl inhibition in pancreatic cancer is currently limited; however, multiple clinical trials have been initiated or are in the planning phase to test the effect of inhibiting Axl in conjunction with standard therapy in pancreatic cancer patients. We anticipate that these studies will provide robust validation of Axl as a therapeutic target in pancreatic cancer.
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41
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Drelich A, Judy B, He X, Chang Q, Yu S, Li X, Lu F, Wakamiya M, Popov V, Zhou J, Ksiazek T, Gong B. Exchange Protein Directly Activated by cAMP Modulates Ebola Virus Uptake into Vascular Endothelial Cells. Viruses 2018; 10:v10100563. [PMID: 30332733 PMCID: PMC6213290 DOI: 10.3390/v10100563] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/13/2018] [Accepted: 10/13/2018] [Indexed: 12/16/2022] Open
Abstract
Members of the family Filoviridae, including Ebola virus (EBOV) and Marburg virus (MARV), cause severe hemorrhagic fever in humans and nonhuman primates. Given their high lethality, a comprehensive understanding of filoviral pathogenesis is urgently needed. In the present studies, we revealed that the exchange protein directly activated by cAMP 1 (EPAC1) gene deletion protects vasculature in ex vivo explants from EBOV infection. Importantly, pharmacological inhibition of EPAC1 using EPAC-specific inhibitors (ESIs) mimicked the EPAC1 knockout phenotype in the ex vivo model. ESI treatment dramatically decreased EBOV infectivity in both ex vivo vasculature and in vitro vascular endothelial cells (ECs). Furthermore, postexposure protection of ECs against EBOV infection was conferred using ESIs. Protective efficacy of ESIs in ECs was observed also in MARV infection. Additional studies using a vesicular stomatitis virus pseudotype that expresses EBOV glycoprotein (EGP-VSV) confirmed that ESIs reduced infection in ECs. Ultrastructural studies suggested that ESIs blocked EGP-VSV internalization via inhibition of macropinocytosis. The inactivation of EPAC1 affects the early stage of viral entry after viral binding to the cell surface, but before early endosome formation, in a phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-dependent manner. Our study delineated a new critical role of EPAC1 during EBOV uptake into ECs.
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Affiliation(s)
- Aleksandra Drelich
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Barbara Judy
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Xi He
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
- Department of Cardiovascular Surgery, Changhai Institute of Cardiovascular Surgery, Shanghai 200433, China.
| | - Qing Chang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Shangyi Yu
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
- Department of Cardiovascular Surgery, Changhai Institute of Cardiovascular Surgery, Shanghai 200433, China.
| | - Xiang Li
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Fanglin Lu
- Department of Cardiovascular Surgery, Changhai Institute of Cardiovascular Surgery, Shanghai 200433, China.
| | - Maki Wakamiya
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Vsevolod Popov
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Thomas Ksiazek
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Bin Gong
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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42
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Maginnis MS. Virus-Receptor Interactions: The Key to Cellular Invasion. J Mol Biol 2018; 430:2590-2611. [PMID: 29924965 PMCID: PMC6083867 DOI: 10.1016/j.jmb.2018.06.024] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/04/2018] [Accepted: 06/08/2018] [Indexed: 11/05/2022]
Abstract
Virus–receptor interactions play a key regulatory role in viral host range, tissue tropism, and viral pathogenesis. Viruses utilize elegant strategies to attach to one or multiple receptors, overcome the plasma membrane barrier, enter, and access the necessary host cell machinery. The viral attachment protein can be viewed as the “key” that unlocks host cells by interacting with the “lock”—the receptor—on the cell surface, and these lock-and-key interactions are critical for viruses to successfully invade host cells. Many common themes have emerged in virus–receptor utilization within and across virus families demonstrating that viruses often target particular classes of molecules in order to mediate these events. Common viral receptors include sialylated glycans, cell adhesion molecules such as immunoglobulin superfamily members and integrins, and phosphatidylserine receptors. The redundancy in receptor usage suggests that viruses target particular receptors or “common locks” to take advantage of their cellular function and also suggests evolutionary conservation. Due to the importance of initial virus interactions with host cells in viral pathogenesis and the redundancy in viral receptor usage, exploitation of these strategies would be an attractive target for new antiviral therapeutics. Viral receptors are key regulators of host range, tissue tropism, and viral pathogenesis. Many viruses utilize common viral receptors including sialic acid, cell adhesion molecules such as immunoglobulin superfamily members and integrins, and phosphatidylserine receptors. Detailed molecular interactions between viruses and receptors have been defined through elegant biochemical analyses including glycan array screens, structural–functional analyses, and cell-based approaches providing tremendous insights into these initial events in viral infection. Commonalities in virus–receptor interactions present promising targets for the development of broad-spectrum antiviral therapies.
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Affiliation(s)
- Melissa S Maginnis
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME 04469-5735, USA.
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43
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Zhao Y, Ren J, Fry EE, Xiao J, Townsend AR, Stuart DI. Structures of Ebola Virus Glycoprotein Complexes with Tricyclic Antidepressant and Antipsychotic Drugs. J Med Chem 2018; 61:4938-4945. [DOI: 10.1021/acs.jmedchem.8b00350] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Yuguang Zhao
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, U.K
| | - Jingshan Ren
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, U.K
| | - Elizabeth E. Fry
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, U.K
| | - Julia Xiao
- Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, U.K
| | - Alain R. Townsend
- Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, U.K
| | - David I. Stuart
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, U.K
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot OX11 0DE, U.K
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44
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Fedeli C, Moreno H, Kunz S. Novel Insights into Cell Entry of Emerging Human Pathogenic Arenaviruses. J Mol Biol 2018; 430:1839-1852. [PMID: 29705070 DOI: 10.1016/j.jmb.2018.04.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/19/2018] [Accepted: 04/21/2018] [Indexed: 12/14/2022]
Abstract
Viral hemorrhagic fevers caused by emerging RNA viruses of the Arenavirus family are among the most devastating human diseases. Climate change, global trade, and increasing urbanization promote the emergence and re-emergence of these human pathogenic viruses. Emerging pathogenic arenaviruses are of zoonotic origin and reservoir-to-human transmission is crucial for spillover into human populations. Host cell attachment and entry are the first and most fundamental steps of every virus infection and represent major barriers for zoonotic transmission. During host cell invasion, viruses critically depend on cellular factors, including receptors, co-receptors, and regulatory proteins of endocytosis. An in-depth understanding of the complex interaction of a virus with cellular factors implicated in host cell entry is therefore crucial to predict the risk of zoonotic transmission, define the tissue tropism, and assess disease potential. Over the past years, investigation of the molecular and cellular mechanisms underlying host cell invasion of human pathogenic arenaviruses uncovered remarkable viral strategies and provided novel insights into viral adaptation and virus-host co-evolution that will be covered in the present review.
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Affiliation(s)
- Chiara Fedeli
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne CH-1011, Switzerland
| | - Héctor Moreno
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne CH-1011, Switzerland
| | - Stefan Kunz
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne CH-1011, Switzerland.
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45
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On the Regularities of the Polar Profiles of Proteins Related to Ebola Virus Infection and their Functional Domains. Cell Biochem Biophys 2018; 76:411-431. [PMID: 29511990 PMCID: PMC7090660 DOI: 10.1007/s12013-018-0839-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 02/16/2018] [Indexed: 11/25/2022]
Abstract
The number of fatalities and economic losses caused by the Ebola virus infection across the planet culminated in the havoc that occurred between August and November 2014. However, little is known about the molecular protein profile of this devastating virus. This work represents a thorough bioinformatics analysis of the regularities of charge distribution (polar profiles) in two groups of proteins and their functional domains associated with Ebola virus disease: Ebola virus proteins and Human proteins interacting with Ebola virus. Our analysis reveals that a fragment exists in each of these proteins—one named the “functional domain”—with the polar profile similar to the polar profile of the protein that contains it. Each protein is formed by a group of short sub-sequences, where each fragment has a different and distinctive polar profile and where the polar profile between adjacent short sub-sequences changes orderly and gradually to coincide with the polar profile of the whole protein. When using the charge distribution as a metric, it was observed that it effectively discriminates the proteins from their functional domains. As a counterexample, the same test was applied to a set of synthetic proteins built for that purpose, revealing that any of the regularities reported here for the Ebola virus proteins and human proteins interacting with Ebola virus were not present in the synthetic proteins. Our results indicate that the polar profile of each protein studied and its corresponding functional domain are similar. Thus, when building each protein from its functional domai—adding one amino acid at a time and plotting each time its polar profile—it was observed that the resulting graphs can be divided into groups with similar polar profiles.
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Fedeli C, Torriani G, Galan-Navarro C, Moraz ML, Moreno H, Gerold G, Kunz S. Axl Can Serve as Entry Factor for Lassa Virus Depending on the Functional Glycosylation of Dystroglycan. J Virol 2018; 92:e01613-17. [PMID: 29237830 PMCID: PMC5809728 DOI: 10.1128/jvi.01613-17] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/04/2017] [Indexed: 11/20/2022] Open
Abstract
Fatal infection with the highly pathogenic Lassa virus (LASV) is characterized by extensive viral dissemination, indicating broad tissue tropism. The major cellular receptor for LASV is the highly conserved extracellular matrix receptor dystroglycan (DG). Binding of LASV depends on DG's tissue-specific posttranslational modification with the unusual O-linked polysaccharide matriglycan. Interestingly, functional glycosylation of DG does not always correlate with viral tropism observed in vivo The broadly expressed phosphatidylserine (PS) receptors Axl and Tyro3 were recently identified as alternative LASV receptor candidates. However, their role in LASV entry is not entirely understood. Here, we examine LASV receptor candidates in primary human cells and found coexpression of Axl with differentially glycosylated DG. To study LASV receptor use in the context of productive arenavirus infection, we employed recombinant lymphocytic choriomeningitis virus expressing LASV glycoprotein (rLCMV-LASV GP) as a validated biosafety level 2 (BSL2) model. We confirm and extend previous work showing that Axl can contribute to LASV entry in the absence of functional DG using "apoptotic mimicry" in a way similar to that of other enveloped viruses. We further show that Axl-dependent LASV entry requires receptor activation and involves a pathway resembling macropinocytosis. Axl-mediated LASV entry is facilitated by heparan sulfate and critically depends on the late endosomal protein LAMP-1 as an intracellular entry factor. In endothelial cells expressing low levels of functional DG, both receptors are engaged by the virus and can contribute to productive entry. In sum, we characterize the role of Axl in LASV entry and provide a rationale for targeting Axl in antiviral therapy.IMPORTANCE 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.
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Affiliation(s)
- Chiara Fedeli
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - Giulia Torriani
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - Clara Galan-Navarro
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
- Laboratory of Lymphatic and Cancer Bioengineering, Institute of Bioengineering, École Polytechnique Féderale de Lausanne (EPFL), Lausanne, Switzerland
| | | | - Hector Moreno
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - Gisa Gerold
- TWINCORE, Center for Experimental and Clinical Infection Research, Institute for Experimental Virology, Hannover, Germany
| | - Stefan Kunz
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
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47
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Nanbo A, Maruyama J, Imai M, Ujie M, Fujioka Y, Nishide S, Takada A, Ohba Y, Kawaoka Y. Ebola virus requires a host scramblase for externalization of phosphatidylserine on the surface of viral particles. PLoS Pathog 2018; 14:e1006848. [PMID: 29338048 PMCID: PMC5786336 DOI: 10.1371/journal.ppat.1006848] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/26/2018] [Accepted: 01/02/2018] [Indexed: 11/30/2022] Open
Abstract
Cell surface receptors for phosphatidylserine contribute to the entry of Ebola virus (EBOV) particles, indicating that the presence of phosphatidylserine in the envelope of EBOV is important for the internalization of EBOV particles. Phosphatidylserine is typically distributed in the inner layer of the plasma membrane in normal cells. Progeny virions bud from the plasma membrane of infected cells, suggesting that phosphatidylserine is likely flipped to the outer leaflet of the plasma membrane in infected cells for EBOV virions to acquire it. Currently, the intracellular dynamics of phosphatidylserine during EBOV infection are poorly understood. Here, we explored the role of XK-related protein (Xkr) 8, which is a scramblase responsible for exposure of phosphatidylserine in the plasma membrane of apoptotic cells, to understand its significance in phosphatidylserine-dependent entry of EBOV. We found that Xkr8 and transiently expressed EBOV glycoprotein GP often co-localized in intracellular vesicles and the plasma membrane. We also found that co-expression of GP and viral major matrix protein VP40 promoted incorporation of Xkr8 into ebolavirus-like particles (VLPs) and exposure of phosphatidylserine on their surface, although only a limited amount of phosphatidylserine was exposed on the surface of the cells expressing GP and/or VP40. Downregulating Xkr8 or blocking caspase-mediated Xkr8 activation did not affect VLP production, but they reduced the amount of phosphatidylserine on the VLPs and their uptake in recipient cells. Taken together, our findings indicate that Xkr8 is trafficked to budding sites via GP-containing vesicles, is incorporated into VLPs, and then promote the entry of the released EBOV to cells in a phosphatidylserine-dependent manner. Although Ebola virus causes severe hemorrhagic fever with a high mortality rate, there are no approved therapeutics. The viral entry process is one of the targets for antiviral development. Previous studies suggest that binding of phosphatidylserine, a component of the viral envelop, to the receptors promotes the entry of Ebola virus. Ebola virus is released from the surface membrane of infected cells. However, phosphatidylserine normally distributes in the inner layer of the cell surface membrane, suggesting that phosphatidylserine is likely flipped to the outer leaflet of the membrane in infected cells for Ebola virus to acquire it. Because the mechanism by which phosphatidylserine changes its orientation in Ebola virus-infected cells is poorly understood, we studied and identified a cellular enzyme, XK-related protein 8 (Xkr8), as a responsible factor involved in this process. We demonstrated that the Ebola virus glycoprotein promoted the incorporation of Xkr8 in viral particles, which flips phosphatidylserine on their surface, enhancing their entry to cells. Our findings provide new insights into the mechanism of Ebola virus infection, which may be exploited for the development of therapeutics against Ebola virus infection.
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Affiliation(s)
- Asuka Nanbo
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- * E-mail: (AN); (YK)
| | - Junki Maruyama
- Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Hokkaido, Japan
| | - Masaki Imai
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Michiko Ujie
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Yoichiro Fujioka
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Shinya Nishide
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Ayato Takada
- Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Hokkaido, Japan
- Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yusuke Ohba
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yoshihiro Kawaoka
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Special Pathogens, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- * E-mail: (AN); (YK)
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Dutta P, Halder AK, Basu S, Kundu M. A survey on Ebola genome and current trends in computational research on the Ebola virus. Brief Funct Genomics 2017; 17:374-380. [DOI: 10.1093/bfgp/elx020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Vesicular Stomatitis Virus Pseudotyped with Ebola Virus Glycoprotein Serves as a Protective, Noninfectious Vaccine against Ebola Virus Challenge in Mice. J Virol 2017; 91:JVI.00479-17. [PMID: 28615211 DOI: 10.1128/jvi.00479-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/07/2017] [Indexed: 11/20/2022] Open
Abstract
The recent Ebola virus (EBOV) epidemic in West Africa demonstrates the potential for a significant public health burden caused by filoviral infections. No vaccine or antiviral is currently FDA approved. To expand the vaccine options potentially available, we assessed protection conferred by an EBOV vaccine composed of vesicular stomatitis virus pseudovirions that lack native G glycoprotein (VSVΔG) and bear EBOV glycoprotein (GP). These pseudovirions mediate a single round of infection. Both single-dose and prime/boost vaccination regimens protected mice against lethal challenge with mouse-adapted Ebola virus (ma-EBOV) in a dose-dependent manner. The prime/boost regimen provided significantly better protection than a single dose. As N-linked glycans are thought to shield conserved regions of the EBOV GP receptor-binding domain (RBD), thereby blocking epitopes within the RBD, we also tested whether VSVΔG bearing EBOV GPs that lack GP1 N-linked glycans provided effective immunity against challenge with ma-EBOV or a more distantly related virus, Sudan virus. Using a prime/boost strategy, high doses of GP/VSVΔG partially or fully denuded of N-linked glycans on GP1 protected mice against ma-EBOV challenge, but these mutants were no more effective than wild-type (WT) GP/VSVΔG and did not provide cross protection against Sudan virus. As reported for other EBOV vaccine platforms, the protection conferred correlated with the quantity of EBOV GP-specific Ig produced but not with the production of neutralizing antibodies. Our results show that EBOV GP/VSVΔG pseudovirions serve as a successful vaccination platform in a rodent model of Ebola virus disease and that GP1 N-glycan loss does not influence immunogenicity or vaccination success.IMPORTANCE The West African Ebola virus epidemic was the largest to date, with more than 28,000 people infected. No FDA-approved vaccines are yet available, but in a trial vaccination strategy in West Africa, recombinant, infectious VSV encoding the Ebola virus glycoprotein effectively prevented virus-associated disease. VSVΔG pseudovirion vaccines may prove as efficacious and have better safety, but they have not been tested to date. Thus, we tested the efficacy of VSVΔG pseudovirions bearing Ebola virus glycoprotein as a vaccine platform. We found that wild-type Ebola virus glycoprotein, in the context of this platform, provides robust protection of EBOV-challenged mice. Further, we found that removal of the heavy glycan shield surrounding conserved regions of the glycoprotein does not enhance vaccine efficacy.
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Genetic Ablation of AXL Does Not Protect Human Neural Progenitor Cells and Cerebral Organoids from Zika Virus Infection. Cell Stem Cell 2017; 19:703-708. [PMID: 27912091 DOI: 10.1016/j.stem.2016.11.011] [Citation(s) in RCA: 198] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/04/2016] [Accepted: 11/14/2016] [Indexed: 11/20/2022]
Abstract
Zika virus (ZIKV) can cross the placental barrier, resulting in infection of the fetal brain and neurological defects including microcephaly. The cellular tropism of ZIKV and the identity of attachment factors used by the virus to gain access to key cell types involved in pathogenesis are under intense investigation. Initial studies suggested that ZIKV preferentially targets neural progenitor cells (NPCs), providing an explanation for the developmental phenotypes observed in some pregnancies. The AXL protein has been nominated as a key attachment factor for ZIKV in several cell types including NPCs. However, here we show that genetic ablation of AXL has no effect on ZIKV entry or ZIKV-mediated cell death in human induced pluripotent stem cell (iPSC)-derived NPCs or cerebral organoids. These findings call into question the utility of AXL inhibitors for preventing birth defects after infection and suggest that further studies of viral attachment factors in NPCs are needed.
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