1
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Shin OS, Monticelli SR, Hjorth CK, Hornet V, Doyle M, Abelson D, Kuehne AI, Wang A, Bakken RR, Mishra A, Middlecamp M, Champney E, Stuart L, Maurer DP, Li J, Berrigan J, Barajas J, Balinandi S, Lutwama JJ, Lobel L, Zeitlin L, Walker LM, Dye JM, Chandran K, Herbert AS, Pauli NT, McLellan JS. Crimean-Congo Hemorrhagic Fever Survivors Elicit Protective Non-Neutralizing Antibodies that Target 11 Overlapping Regions on Viral Glycoprotein GP38. bioRxiv 2024:2024.03.02.583110. [PMID: 38496658 PMCID: PMC10942344 DOI: 10.1101/2024.03.02.583110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Crimean-Congo hemorrhagic fever virus can cause lethal disease in humans yet there are no approved medical countermeasures. Viral glycoprotein GP38, unique to Nairoviridae, is a target of protective antibodies, but extensive mapping of the human antibody response to GP38 has not been previously performed. Here, we isolated 188 GP38-specific antibodies from human survivors of infection. Competition experiments showed that these antibodies bind across five distinct antigenic sites, encompassing eleven overlapping regions. Additionally, we reveal structures of GP38 bound with nine of these antibodies targeting different antigenic sites. Although GP38-specific antibodies were non-neutralizing, several antibodies were found to have protection equal to or better than murine antibody 13G8 in two highly stringent rodent models of infection. Together, these data expand our understanding regarding this important viral protein and inform the development of broadly effective CCHFV antibody therapeutics.
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Affiliation(s)
| | - Stephanie R. Monticelli
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
- Geneva Foundation, Tacoma, WA 98042, USA
| | - Christy K. Hjorth
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | | | | | - Dafna Abelson
- Mapp Biopharmaceutical, Inc., San Diego, CA 92121, USA
| | - Ana I. Kuehne
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Albert Wang
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Russell R. Bakken
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Akaash Mishra
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | | | | | - Lauran Stuart
- Mapp Biopharmaceutical, Inc., San Diego, CA 92121, USA
| | | | | | - Jacob Berrigan
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | | | | | - Leslie Lobel
- Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Larry Zeitlin
- Mapp Biopharmaceutical, Inc., San Diego, CA 92121, USA
| | | | - John M. Dye
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Kartik Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Andrew S. Herbert
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | | | - Jason S. McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
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2
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Yu C, Wang G, Liu Q, Zhai J, Xue M, Li Q, Xian Y, Zheng C. Host antiviral factors hijack furin to block SARS-CoV-2, ebola virus, and HIV-1 glycoproteins cleavage. Emerg Microbes Infect 2023; 12:2164742. [PMID: 36591809 PMCID: PMC9897805 DOI: 10.1080/22221751.2022.2164742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Viral envelope glycoproteins are crucial for viral infections. In the process of enveloped viruses budding and release from the producer cells, viral envelope glycoproteins are presented on the viral membrane surface as spikes, promoting the virus's next-round infection of target cells. However, the host cells evolve counteracting mechanisms in the long-term virus-host co-evolutionary processes. For instance, the host cell antiviral factors could potently suppress viral replication by targeting their envelope glycoproteins through multiple channels, including their intracellular synthesis, glycosylation modification, assembly into virions, and binding to target cell receptors. Recently, a group of studies discovered that some host antiviral proteins specifically recognized host proprotein convertase (PC) furin and blocked its cleavage of viral envelope glycoproteins, thus impairing viral infectivity. Here, in this review, we briefly summarize several such host antiviral factors and analyze their roles in reducing furin cleavage of viral envelope glycoproteins, aiming at providing insights for future antiviral studies.
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Affiliation(s)
- Changqing Yu
- School of Advanced Agricultural Sciences, Yibin Vocational and Technical College, Yibin, People’s Republic of China
| | - Guosheng Wang
- Department of Pulmonary and Critical Care Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Qiang Liu
- Nanchong Key Laboratory of Disease Prevention, Control and Detection in Livestock and Poultry, Nanchong Vocational and Technical College, Nanchong, People’s Republic of China
| | - Jingbo Zhai
- Key Laboratory of Zoonose Prevention and Control at Universities of Inner Mongolia Autonomous Region, Medical College, Inner Mongolia Minzu University, Tongliao, People’s Republic of China
| | - Mengzhou Xue
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, People’s Republic of China,Mengzhou Xue
| | - Qiang Li
- Department of Pulmonary and Critical Care Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China,Qiang Li
| | - Yuanhua Xian
- School of Advanced Agricultural Sciences, Yibin Vocational and Technical College, Yibin, People’s Republic of China,Yuanhua Xian
| | - Chunfu Zheng
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Key Laboratory of Livestock Disease Prevention of Guangdong Province, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, People’s Republic of China,Department of Microbiology, Immunology & Infection Diseases, University of Calgary, Calgary, Canada, Chunfu Zheng
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3
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Moon-Walker A, Zhang Z, Zyla DS, Buck TK, Li H, Diaz Avalos R, Schendel SL, Hastie KM, Crotty S, Saphire EO. Structural basis for antibody-mediated neutralization of lymphocytic choriomeningitis virus. Cell Chem Biol 2023; 30:403-411.e4. [PMID: 36990092 DOI: 10.1016/j.chembiol.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/23/2022] [Accepted: 03/08/2023] [Indexed: 03/30/2023]
Abstract
The mammarenavirus lymphocytic choriomeningitis virus (LCMV) is a globally distributed zoonotic pathogen that can be lethal in immunocompromised patients and can cause severe birth defects if acquired during pregnancy. The structure of the trimeric surface glycoprotein, essential for entry, vaccine design, and antibody neutralization, remains unknown. Here, we present the cryoelectron microscopy (cryo-EM) structure of the LCMV surface glycoprotein (GP) in its trimeric pre-fusion assembly both alone and in complex with a rationally engineered monoclonal neutralizing antibody termed 18.5C-M28 (M28). Additionally, we show that passive administration of M28, either as a prophylactic or therapeutic, protects mice from LCMV clone 13 (LCMVcl13) challenge. Our study illuminates not only the overall structural organization of LCMV GP and the mechanism for its inhibition by M28 but also presents a promising therapeutic candidate to prevent severe or fatal disease in individuals who are at risk of infection by a virus that poses a threat worldwide.
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Affiliation(s)
- Alex Moon-Walker
- La Jolla Institute for Immunology; La Jolla, CA 92037, USA; Program in Virology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Microbiology, Washington University in St. Louis, St. Louis, MI 63110, USA
| | - Zeli Zhang
- La Jolla Institute for Immunology; La Jolla, CA 92037, USA
| | - Dawid S Zyla
- La Jolla Institute for Immunology; La Jolla, CA 92037, USA
| | - Tierra K Buck
- La Jolla Institute for Immunology; La Jolla, CA 92037, USA; Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Haoyang Li
- La Jolla Institute for Immunology; La Jolla, CA 92037, USA
| | | | | | | | - Shane Crotty
- La Jolla Institute for Immunology; La Jolla, CA 92037, USA.
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4
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Scherm MJ, Gangloff M, Gay NJ. Activation of Toll-like receptor 4 by Ebola virus-shed glycoprotein is direct and requires the internal fusion loop but not glycosylation. Cell Rep 2022; 41:111562. [PMID: 36288690 PMCID: PMC9637988 DOI: 10.1016/j.celrep.2022.111562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/16/2022] [Accepted: 10/04/2022] [Indexed: 12/03/2022] Open
Abstract
Infection by the Ebola virus, a member of the Filoviridae family of RNA viruses, leads to acute viral hemorrhagic fever. End-stage Ebola virus disease is characterized by a cytokine storm that causes tissue damage, vascular disintegration, and multi-organ failure. Previous studies showed that a shed form of the viral spike glycoprotein (sGP1,2) drives this hyperinflammatory response by activating Toll-like receptor 4 (TLR4). Here, we find that glycosylation is not required for activation of TLR4 by sGP1,2 and identify the internal fusion loop (IFL) as essential for inflammatory signaling. sGP1,2 competes with lipid antagonists of TLR4, and the IFL interacts directly with TLR4 and co-receptor MD2. Together, these findings indicate that sGP1,2 activates TLR4 analogously to bacterial agonist lipopolysaccharide (LPS) by binding into a hydrophobic pocket in MD2 and promoting the formation of an active heterotetramer. This conclusion is supported by docking studies that predict binding sites for sGP1,2 on TLR4 and MD2.
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Affiliation(s)
- Michael J. Scherm
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Monique Gangloff
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Nicholas J. Gay
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK,Corresponding author
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5
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Munz CM, Kreher H, Erdbeer A, Richter S, Westphal D, Yi B, Behrendt R, Stanke N, Lindel F, Lindemann D. Efficient production of inhibitor-free foamy virus glycoprotein-containing retroviral vectors by proteoglycan-deficient packaging cells. Mol Ther Methods Clin Dev 2022; 26:394-412. [PMID: 36034773 PMCID: PMC9388887 DOI: 10.1016/j.omtm.2022.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 07/07/2022] [Indexed: 11/21/2022]
Abstract
Foamy viruses (FVs) or heterologous retroviruses pseudotyped with FV glycoprotein enable transduction of a great variety of target tissues of disparate species. Specific cellular entry receptors responsible for this exceptionally broad tropism await their identification. Though, ubiquitously expressed heparan sulfate proteoglycan (HS-PG) is known to serve as an attachment factor of FV envelope (Env)-containing virus particles, greatly enhancing target cell permissiveness. Production of high-titer, FV Env-containing retroviral vectors is strongly dependent on the use of cationic polymer-based transfection reagents like polyethyleneimine (PEI). We identified packaging cell-surface HS-PG expression to be responsible for this requirement. Efficient release of FV Env-containing virus particles necessitates neutralization of HS-PG binding sites by PEI. Remarkably, remnants of PEI in FV Env-containing vector supernatants, which are not easily removable, negatively impact target cell transduction, in particular those of myeloid and lymphoid origin. To overcome this limitation for production of FV Env-containing retrovirus supernatants, we generated 293T-based packaging cell lines devoid of HS-PG by genome engineering. This enabled, for the first, time production of inhibitor-free, high-titer FV Env-containing virus supernatants by non-cationic polymer-mediated transfection. Depending on the type of virus, produced titers were 2- to 10-fold higher compared with those obtained by PEI transfection.
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Affiliation(s)
- Clara Marie Munz
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Henriette Kreher
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Alexander Erdbeer
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Stefanie Richter
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
| | - Dana Westphal
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Buqing Yi
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
| | - Rayk Behrendt
- Institute of Immunology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany
| | - Nicole Stanke
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
| | - Fabian Lindel
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Corresponding author Fabian Lindel,Cell line Screening & Development (CLSD), Novartis Institutes for BioMedical Research (NIBR), WSJ-360, Kohlenstrasse, 4056 Basel, Switzerland.
| | - Dirk Lindemann
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
- Corresponding author Dirk Lindemann, Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
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6
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Hu K, McKay PF, Samnuan K, Najer A, Blakney AK, Che J, O'Driscoll G, Cihova M, Stevens MM, Shattock RJ. Presentation of antigen on extracellular vesicles using transmembrane domains from viral glycoproteins for enhanced immunogenicity. J Extracell Vesicles 2022; 11:e12199. [PMID: 35233930 PMCID: PMC8888812 DOI: 10.1002/jev2.12199] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 02/02/2022] [Accepted: 02/15/2022] [Indexed: 12/03/2022] Open
Abstract
A vaccine antigen, when launched as DNA or RNA, can be presented in various forms, including intracellular, secreted, membrane-bound, or on extracellular vesicles (EVs). Whether an antigen in one or more of these forms is superior in immune induction remains unclear. In this study, we used GFP as a model antigen and first compared the EV-loading efficiency of transmembrane domains (TMs) from various viral glycoproteins, and then investigated whether EV-bound GFP (EV-GFP) would enhance immune induction. Our data showed that GFP fused to viral TMs was successfully loaded onto the surface of EVs. In addition, GFP-bound EVs were predominantly associated with the exosome marker CD81. Immunogenicity study with EV-GFP-producing plasmids in mice demonstrated that antigen-specific IgG and IgA were significantly increased in EV-GFP groups, compared to soluble and intracellular GFP groups. Similarly, GFP-specific T cell response-related cytokines produced by antigen-stimulated splenocytes were also enhanced in mice immunized with EV-GFP constructs. Immunogenicity study with purified soluble GFP and GFP EVs further confirmed the immune enhancement property of EV-GFP in mice. In vitro uptake assays indicated that EV-GFP was more efficiently taken up than soluble GFP by mouse splenocytes and such uptake was B cell preferential. Taken together, our data indicate that viral TMs can efficiently load antigens onto the EV surface, and that EV-bound antigen enhances both humoral and cell-mediated antigen-specific responses.
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Affiliation(s)
- Kai Hu
- Department of Infectious DiseasesImperial College LondonLondonUK
| | - Paul F. McKay
- Department of Infectious DiseasesImperial College LondonLondonUK
| | - Karnyart Samnuan
- Department of Infectious DiseasesImperial College LondonLondonUK
| | - Adrian Najer
- Department of MaterialsDepartment of Bioengineeringand Institute of Biomedical EngineeringImperial College LondonLondonUK
| | - Anna K. Blakney
- Department of Infectious DiseasesImperial College LondonLondonUK
| | - Junyi Che
- Department of MaterialsDepartment of Bioengineeringand Institute of Biomedical EngineeringImperial College LondonLondonUK
| | - Gwen O'Driscoll
- Department of MaterialsDepartment of Bioengineeringand Institute of Biomedical EngineeringImperial College LondonLondonUK,Division of Radiotherapy and ImagingThe Institute of Cancer ResearchLondonUK
| | - Martina Cihova
- Department of MaterialsDepartment of Bioengineeringand Institute of Biomedical EngineeringImperial College LondonLondonUK
| | - Molly M. Stevens
- Department of MaterialsDepartment of Bioengineeringand Institute of Biomedical EngineeringImperial College LondonLondonUK
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7
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Abstract
Retroviral elements from endogenous retroviruses have functions in mammalian physiology. The best-known examples are the envelope proteins that function in placenta development and immune suppression. Porcine endogenous retroviruses (PERVs) are an understudied class of endogenous retroviruses that infect cultured human cells, raising concern regarding porcine xenografts. The PERV envelope glycoprotein has also been proposed as a possible swine syncytin with a role in placental development. Despite the growing interest in PERVs, their envelope glycoproteins remain poorly characterized. Here, we successfully determined the postfusion crystal structure of the PERV core fusion ectodomain. The PERV fusion protein structure reveals a conserved class I viral fusion protein six-helix bundle. Biophysical experiments demonstrated that the thermodynamic stability of the PERV fusion protein secondary structure was the same at physiological and acidic pHs. A conserved surface analysis highlights the high degree of sequence conservation among retroviral fusogens in the chain reversal region that facilitates the large-scale conformational change required for membrane fusion. Further structural alignment of class I viral fusogens revealed a phylogenetic clustering that shows evolution into various lineages that correlate with virus mechanisms of cell entry. Our work indicates that structural dendrograms can be used to qualitatively infer insights into the fusion mechanisms of newly discovered class I viral fusogen structures. IMPORTANCE Class I viral fusion proteins represent a diverse group of fusogens that catalyze membrane fusion. Although structural studies have focused on those from exogenous viruses, ancient retroviral infections of germ line cells have immortalized ancient fusogens in eukaryotic genomes. These "fossilized" glycoproteins are poorly defined compared to modern fusogens. In this study, we characterized and determined the structure of the porcine endogenous retrovirus fusogen, an ancient retroviral element captured by swine. This fusion protein revealed remarkable alignment to exogenous retroviral fusion proteins, suggesting that fossil fusogens utilize similar structural determinants to perform membrane fusion. Moreover, structural phylogenetic analysis demonstrates that class I viral fusogens cluster into distinct lineages defined by mechanism of membrane fusion. Our results suggest that structural dendrograms can be used to infer mechanistic insights for uncharacterized fusion proteins.
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8
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Borriello F, Poli V, Shrock E, Spreafico R, Liu X, Pishesha N, Carpenet C, Chou J, Di Gioia M, McGrath ME, Dillen CA, Barrett NA, Lacanfora L, Franco ME, Marongiu L, Iwakura Y, Pucci F, Kruppa MD, Ma Z, Lowman DW, Ensley HE, Nanishi E, Saito Y, O'Meara TR, Seo HS, Dhe-Paganon S, Dowling DJ, Frieman M, Elledge SJ, Levy O, Irvine DJ, Ploegh HL, Williams DL, Zanoni I. An adjuvant strategy enabled by modulation of the physical properties of microbial ligands expands antigen immunogenicity. Cell 2022; 185:614-629.e21. [PMID: 35148840 PMCID: PMC8857056 DOI: 10.1016/j.cell.2022.01.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 10/19/2021] [Accepted: 01/14/2022] [Indexed: 12/15/2022]
Abstract
Activation of the innate immune system via pattern recognition receptors (PRRs) is key to generate lasting adaptive immunity. PRRs detect unique chemical patterns associated with invading microorganisms, but whether and how the physical properties of PRR ligands influence the development of the immune response remains unknown. Through the study of fungal mannans, we show that the physical form of PRR ligands dictates the immune response. Soluble mannans are immunosilent in the periphery but elicit a potent pro-inflammatory response in the draining lymph node (dLN). By modulating the physical form of mannans, we developed a formulation that targets both the periphery and the dLN. When combined with viral glycoprotein antigens, this mannan formulation broadens epitope recognition, elicits potent antigen-specific neutralizing antibodies, and confers protection against viral infections of the lung. Thus, the physical properties of microbial ligands determine the outcome of the immune response and can be harnessed for vaccine development.
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Affiliation(s)
- Francesco Borriello
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA; Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Valentina Poli
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA
| | - Ellen Shrock
- Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute, Division of Genetics, Brigham and Women's Hospital, Program in Virology, Boston, MA, USA
| | - Roberto Spreafico
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, Los Angeles, CA, USA
| | - Xin Liu
- Harvard Medical School, Boston, MA, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Novalia Pishesha
- Harvard Medical School, Boston, MA, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Claire Carpenet
- Harvard Medical School, Boston, MA, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Janet Chou
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA
| | - Marco Di Gioia
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA
| | - Marisa E McGrath
- University of Maryland School of Medicine, Department of Microbiology and Immunology, Baltimore, MD, USA
| | - Carly A Dillen
- University of Maryland School of Medicine, Department of Microbiology and Immunology, Baltimore, MD, USA
| | - Nora A Barrett
- Harvard Medical School, Boston, MA, USA; Brigham and Women's Hospital, Division of Allergy and Clinical Immunology, Boston, MA, USA
| | - Lucrezia Lacanfora
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA; Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Marcella E Franco
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA; Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Laura Marongiu
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Yoichiro Iwakura
- Center for Animal Disease Models, Research Institute for Biomedical Sciences, Tokyo University of Science, Tokyo, Japan
| | - Ferdinando Pucci
- Department of Otolaryngology-Head and Neck Surgery, Department of Cell, Developmental & Cancer Biology, Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - Michael D Kruppa
- Department of Biomedical Sciences, Quillen College of Medicine, Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, USA
| | - Zuchao Ma
- Department of Surgery, Quillen College of Medicine, Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, USA
| | - Douglas W Lowman
- Department of Surgery, Quillen College of Medicine, Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, USA
| | - Harry E Ensley
- Department of Surgery, Quillen College of Medicine, Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, USA
| | - Etsuro Nanishi
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Precision Vaccines Program, Boston, MA, USA
| | - Yoshine Saito
- Boston Children's Hospital, Precision Vaccines Program, Boston, MA, USA
| | - Timothy R O'Meara
- Boston Children's Hospital, Precision Vaccines Program, Boston, MA, USA
| | - Hyuk-Soo Seo
- Harvard Medical School, Boston, MA, USA; Dana-Farber Cancer Institute, Department of Cancer Biology, Boston, MA, USA
| | - Sirano Dhe-Paganon
- Harvard Medical School, Boston, MA, USA; Dana-Farber Cancer Institute, Department of Cancer Biology, Boston, MA, USA
| | - David J Dowling
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Precision Vaccines Program, Boston, MA, USA
| | - Matthew Frieman
- University of Maryland School of Medicine, Department of Microbiology and Immunology, Baltimore, MD, USA
| | - Stephen J Elledge
- Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute, Division of Genetics, Brigham and Women's Hospital, Program in Virology, Boston, MA, USA
| | - Ofer Levy
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Precision Vaccines Program, Boston, MA, USA; Broad Institute of MIT & Harvard, Cambridge, MA, USA
| | - Darrell J Irvine
- Massachusetts Institute of Technology, Department of Biological Engineering and Department of Materials Science and Engineering, Koch Institute for Integrative Cancer Research, Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Hidde L Ploegh
- Harvard Medical School, Boston, MA, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - David L Williams
- Department of Biomedical Sciences, Quillen College of Medicine, Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, USA
| | - Ivan Zanoni
- Harvard Medical School, Boston, MA, USA; Boston Children's Hospital, Division of Immunology, Boston, MA, USA; Boston Children's Hospital, Division of Gastroenterology, Boston, MA, USA.
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9
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Lennemann NJ, Dillard J, Ruggio N, Cooney AL, Schaack GA, Davey RA, Maury W. 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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [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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Fels JM, Maurer DP, Herbert AS, Wirchnianski AS, Vergnolle O, Cross RW, Abelson DM, Moyer CL, Mishra AK, Aguilan JT, Kuehne AI, Pauli NT, Bakken RR, Nyakatura EK, Hellert J, Quevedo G, Lobel L, Balinandi S, Lutwama JJ, Zeitlin L, Geisbert TW, Rey FA, Sidoli S, McLellan JS, Lai JR, Bornholdt ZA, Dye JM, Walker LM, Chandran K. Protective neutralizing antibodies from human survivors of Crimean-Congo hemorrhagic fever. Cell 2021; 184:3486-3501.e21. [PMID: 34077751 DOI: 10.1016/j.cell.2021.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/19/2021] [Accepted: 04/29/2021] [Indexed: 12/31/2022]
Abstract
Crimean-Congo hemorrhagic fever virus (CCHFV) is a World Health Organization priority pathogen. CCHFV infections cause a highly lethal hemorrhagic fever for which specific treatments and vaccines are urgently needed. Here, we characterize the human immune response to natural CCHFV infection to identify potent neutralizing monoclonal antibodies (nAbs) targeting the viral glycoprotein. Competition experiments showed that these nAbs bind six distinct antigenic sites in the Gc subunit. These sites were further delineated through mutagenesis and mapped onto a prefusion model of Gc. Pairwise screening identified combinations of non-competing nAbs that afford synergistic neutralization. Further enhancements in neutralization breadth and potency were attained by physically linking variable domains of synergistic nAb pairs through bispecific antibody (bsAb) engineering. Although multiple nAbs protected mice from lethal CCHFV challenge in pre- or post-exposure prophylactic settings, only a single bsAb, DVD-121-801, afforded therapeutic protection. DVD-121-801 is a promising candidate suitable for clinical development as a CCHFV therapeutic.
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Affiliation(s)
- J Maximilian Fels
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - Andrew S Herbert
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA; The Geneva Foundation, Tacoma, WA 98402, USA
| | - Ariel S Wirchnianski
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Deparment of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Olivia Vergnolle
- Deparment of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Robert W Cross
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX 77550, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | | | | | - Akaash K Mishra
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Jennifer T Aguilan
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ana I Kuehne
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | | | - Russell R Bakken
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Elisabeth K Nyakatura
- Deparment of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jan Hellert
- Structural Virology Unit, Department of Virology, CNRS UMR 3569, Institut Pasteur, Paris 75724, France
| | - Gregory Quevedo
- Deparment of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Leslie Lobel
- Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | | | | | - Larry Zeitlin
- Mapp Biopharmaceutical, Inc., San Diego, CA 92121, USA
| | - Thomas W Geisbert
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX 77550, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Felix A Rey
- Structural Virology Unit, Department of Virology, CNRS UMR 3569, Institut Pasteur, Paris 75724, France
| | - Simone Sidoli
- Deparment of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Jonathan R Lai
- Deparment of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - John M Dye
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA.
| | - Laura M Walker
- Adimab, LLC, Lebanon, NH 03766, USA; Adagio Therapeutics, Inc., Waltham, MA 02451, USA.
| | - Kartik Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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11
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Kalemera MD, Capella-Pujol J, Chumbe A, Underwood A, Bull RA, Schinkel J, Sliepen K, Grove J. Optimized cell systems for the investigation of hepatitis C virus E1E2 glycoproteins. J Gen Virol 2021; 102. [PMID: 33147126 PMCID: PMC8116788 DOI: 10.1099/jgv.0.001512] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Great strides have been made in understanding and treating hepatitis C virus (HCV) thanks to the development of various experimental systems including cell-culture-proficient HCV, the HCV pseudoparticle system and soluble envelope glycoproteins. The HCV pseudoparticle (HCVpp) system is a platform used extensively in studies of cell entry, screening of novel entry inhibitors, assessing the phenotypes of clinically observed E1 and E2 glycoproteins and, most pertinently, in characterizing neutralizing antibody breadth induced upon vaccination and natural infection in patients. Nonetheless, some patient-derived clones produce pseudoparticles that are either non-infectious or exhibit infectivity too low for meaningful phenotyping. The mechanisms governing whether any particular clone produces infectious pseudoparticles are poorly understood. Here we show that endogenous expression of CD81, an HCV receptor and a cognate-binding partner of E2, in producer HEK 293T cells is detrimental to the infectivity of recovered HCVpp for most strains. Many HCVpp clones exhibited increased infectivity or had their infectivity rescued when they were produced in 293T cells CRISPR/Cas9 engineered to ablate CD81 expression (293TCD81KO). Clones made in 293TCD81KO cells were antigenically very similar to their matched counterparts made parental cells and appear to honour the accepted HCV entry pathway. Deletion of CD81 did not appreciably increase the recovered titres of soluble E2 (sE2). However, we did, unexpectedly, find that monomeric sE2 made in 293T cells and Freestyle 293-F (293-F) cells exhibit important differences. We found that 293-F-produced sE2 harbours mostly complex-type glycans whilst 293T-produced sE2 displays a heterogeneous mixture of both complex-type glycans and high-mannose or hybrid-type glycans. Moreover, sE2 produced in 293T cells is antigenically superior; exhibiting increased binding to conformational antibodies and the large extracellular loop of CD81. In summary, this work describes an optimal cell line for the production of HCVpp and reveals that sE2 made in 293T and 293-F cells are not antigenic equals. Our findings have implications for functional studies of E1E2 and the production of candidate immunogens.
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Affiliation(s)
- Mphatso D Kalemera
- Institute of Immunity and Transplantation, Division of Infection and Immunity, The Royal Free Hospital, University College London, London, UK
| | - Joan Capella-Pujol
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Ana Chumbe
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Alexander Underwood
- Viral Immunology Systems Program, The Kirby Institute, School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Rowena A Bull
- Viral Immunology Systems Program, The Kirby Institute, School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Janke Schinkel
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Kwinten Sliepen
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, The Royal Free Hospital, University College London, London, UK
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Serrão VHB, Cook JD, Lee JE. Snapshot of an influenza virus glycoprotein fusion intermediate. Cell Rep 2021; 35:109152. [PMID: 34010634 DOI: 10.1016/j.celrep.2021.109152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/31/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022] Open
Abstract
Enveloped virus entry requires the fusion of cellular and viral membranes, a process directed by their viral fusion glycoproteins. Our current knowledge of this process has been shaped by structural studies of the pre- and post-fusion conformations of these viral fusogens. These structural snapshots have revealed the start and end states necessary for fusion, but the dynamics of the intermediate conformations have remained unclear. Using the influenza C virus hemagglutinin-esterase-fusion glycoprotein as a model, we report the structural and biophysical characterization of a trapped intermediate. Crystallographic studies revealed a structural reorganization of the C terminus to create a second chain reversal region, resulting in the N and C termini being positioned in opposing directions. Intrinsic tryptophan fluorescence and bimane-induced quenching measurements suggest intermediate formation is mediated by conserved hydrophobic residues. Our study reveals a late-stage extended intermediate structural event. This work adds to our understanding of virus cell fusion.
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Affiliation(s)
- Vitor Hugo B Serrão
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Jonathan D Cook
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Jeffrey E Lee
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.
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Serra PA, Taveira N, Guedes RC. Computational Modulation of the V3 Region of Glycoprotein gp125 of HIV-2. Int J Mol Sci 2021; 22:1948. [PMID: 33669351 PMCID: PMC7920276 DOI: 10.3390/ijms22041948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/10/2021] [Accepted: 02/13/2021] [Indexed: 12/03/2022] Open
Abstract
HIV-2 infection is frequently neglected in HIV/AIDS campaigns. However, a special emphasis must be given to HIV-2 as an untreated infection that also leads to AIDS and death, and for which the efficacy of most available drugs is limited against HIV-2. HIV envelope glycoproteins mediate binding to the receptor CD4 and co-receptors at the surface of the target cell, enabling fusion with the cell membrane and viral entry. Here, we developed and optimized a computer-assisted drug design approach of an important HIV-2 glycoprotein that allows us to explore and gain further insights at the molecular level into protein structures and interactions crucial for the inhibition of HIV-2 cell entry. The 3D structure of a key HIV-2ROD gp125 region was generated by a homology modeling campaign. To disclose the importance of the main structural features and compare them with experimental results, 3D-models of six mutants were also generated. These mutations revealed the selective impact on the behavior of the protein. Furthermore, molecular dynamics simulations were performed to optimize the models, and the dynamic behavior was tackled to account for structure flexibility and interactions network formation. Structurally, the mutations studied lead to a loss of aromatic features, which is very important for the establishment of π-π interactions and could induce a structural preference by a specific coreceptor. These new insights into the structure-function relationship of HIV-2 gp125 V3 and surrounding regions will help in the design of better models and the design of new small molecules capable to inhibit the attachment and binding of HIV with host cells.
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Affiliation(s)
- Patrícia A. Serra
- Department of Pharmaceutical Sciences and Medicines and Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal;
| | - Nuno Taveira
- Department of Pharmaceutical Sciences and Medicines and Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal;
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, Monte de Caparica, 2829-511 Caparica, Portugal
| | - Rita C. Guedes
- Department of Pharmaceutical Sciences and Medicines and Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal;
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14
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Ahi YS, Yimer D, Shi G, Majdoul S, Rahman K, Rein A, Compton AA. IFITM3 Reduces Retroviral Envelope Abundance and Function and Is Counteracted by glycoGag. mBio 2020; 11:e03088-19. [PMID: 31964738 DOI: 10.1128/mBio.03088-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Interferon-induced transmembrane (IFITM) proteins are encoded by many vertebrate species and exhibit antiviral activities against a wide range of viruses. IFITM3, when present in virus-producing cells, reduces the fusion potential of HIV-1 virions, but the mechanism is poorly understood. To define the breadth and mechanistic basis for the antiviral activity of IFITM3, we took advantage of a murine leukemia virus (MLV)-based pseudotyping system. By carefully controlling amounts of IFITM3 and envelope protein (Env) in virus-producing cells, we found that IFITM3 potently inhibits MLV infectivity when Env levels are limiting. Loss of infectivity was associated with defective proteolytic processing of Env and lysosomal degradation of the Env precursor. Ecotropic and xenotropic variants of MLV Env, as well as HIV-1 Env and vesicular stomatitis virus glycoprotein (VSV-G), are sensitive to IFITM3, whereas Ebola glycoprotein is resistant, suggesting that IFITM3 selectively inactivates certain viral glycoproteins. Furthermore, endogenous IFITM3 in human and murine cells negatively regulates MLV Env abundance. However, we found that the negative impact of IFITM3 on virion infectivity is greater than its impact on decreasing Env incorporation, suggesting that IFITM3 may impair Env function, as well as reduce the amount of Env in virions. Finally, we demonstrate that loss of virion infectivity mediated by IFITM3 is reversed by the expression of glycoGag, a murine retrovirus accessory protein previously shown to antagonize the antiviral activity of SERINC proteins. Overall, we show that IFITM3 impairs virion infectivity by regulating Env quantity and function but that enhanced Env expression and glycoGag confer viral resistance to IFITM3.IMPORTANCE The viral envelope glycoprotein, known as "Env" in Retroviridae, is found on the virion surface and facilitates virus entry into cells by mediating cell attachment and fusion. Env is a major structural component of retroviruses and is targeted by all arms of the immune response, including adaptive and innate immunity. Less is known about how cell-intrinsic immunity prevents retrovirus replication at the level of individual cells. Here, we show that cellular IFITM3 and IFITM2 inhibit the fusion potential of retroviral virions by inhibiting Env protein via a two-pronged mechanism. IFITM proteins inhibit Env abundance in cells and also impair its function when levels are low. The posttranslational block of retroviral Env function by IFITM proteins is likely to impede both exogenous and endogenous retrovirus replication. In support of a relevant role for IFITM3 in retrovirus control, the retroviral accessory protein glycoGag counteracts IFITM3 function to promote virus infectivity.
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15
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Willard KA, Alston JT, Acciani M, Brindley MA. Identification of Residues in Lassa Virus Glycoprotein Subunit 2 That Are Critical for Protein Function. Pathogens 2018; 8:E1. [PMID: 30587764 DOI: 10.3390/pathogens8010001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/20/2018] [Accepted: 12/22/2018] [Indexed: 11/17/2022] Open
Abstract
Lassa virus (LASV) is an Old World arenavirus, endemic to West Africa, capable of causing hemorrhagic fever. Currently, there are no approved vaccines or effective antivirals for LASV. However, thorough understanding of the LASV glycoprotein and entry into host cells could accelerate therapeutic design. LASV entry is a two-step process involving the viral glycoprotein (GP). First, the GP subunit 1 (GP1) binds to the cell surface receptor and the viral particle is engulfed into an endosome. Next, the drop in pH triggers GP rearrangements, which ultimately leads to the GP subunit 2 (GP2) forming a six-helix-bundle (6HB). The process of GP2 forming 6HB fuses the lysosomal membrane with the LASV envelope, allowing the LASV genome to enter the host cell. The aim of this study was to identify residues in GP2 that are crucial for LASV entry. To achieve this, we performed alanine scanning mutagenesis on GP2 residues. We tested these mutant GPs for efficient GP1-GP2 cleavage, cell-to-cell membrane fusion, and transduction into cells expressing α-dystroglycan and secondary LASV receptors. In total, we identified seven GP2 mutants that were cleaved efficiently but were unable to effectively transduce cells: GP-L280A, GP-L285A/I286A, GP-I323A, GP-L394A, GP-I403A, GP-L415A, and GP-R422A. Therefore, the data suggest these residues are critical for GP2 function in LASV entry.
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16
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Locher S, Schweneker M, Hausmann J, Zimmer G. Immunogenicity of propagation-restricted vesicular stomatitis virus encoding Ebola virus glycoprotein in guinea pigs. J Gen Virol 2018; 99:866-879. [PMID: 29869979 PMCID: PMC6152369 DOI: 10.1099/jgv.0.001085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vesicular stomatitis virus (VSV) expressing the Ebola virus (EBOV) glycoprotein (GP) in place of the VSV glycoprotein G (VSV/EBOV-GP) is a promising EBOV vaccine candidate which has already entered clinical phase 3 studies. Although this chimeric virus was tolerated overall by volunteers, it still caused viremia and adverse effects such as fever and arthritis, suggesting that it might not be sufficiently attenuated. In this study, the VSV/EBOV-GP vector was further modified in order to achieve attenuation while maintaining immunogenicity. All recombinant VSV constructs were propagated on VSV G protein expressing helper cells and used to immunize guinea pigs via the intramuscular route. The humoral immune response was analysed by EBOV-GP-specific fluorescence-linked immunosorbent assay, plaque reduction neutralization test and in vitro virus-spreading inhibition test that employed recombinant VSV/EBOV-GP expressing either green fluorescent protein or secreted Nano luciferase. Most modified vector constructs induced lower levels of protective antibodies than the parental VSV/EBOV-GP or a recombinant modified vaccinia virus Ankara vector encoding full-length EBOV-GP. However, the VSV/EBOV-GP(F88A) mutant was at least as immunogenic as the parental vaccine virus although it was highly propagation-restricted. This finding suggests that VSV-vectored vaccines need not be propagation-competent to induce a robust humoral immune response. However, VSV/EBOV-GP(F88A) rapidly reverted to a fully propagation-competent virus indicating that a single-point mutation is not sufficient to maintain the propagation-restricted phenotype.
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Affiliation(s)
- Samira Locher
- Institut für Virologie und Immunologie (IVI), Sensemattstrasse 293, CH-3147 Mittelhäusern, Switzerland
| | - Marc Schweneker
- Bavarian Nordic GmbH, Fraunhoferstraße 13, D-82152 Martinsried, Germany
| | - Jürgen Hausmann
- Bavarian Nordic GmbH, Fraunhoferstraße 13, D-82152 Martinsried, Germany
| | - Gert Zimmer
- Institut für Virologie und Immunologie (IVI), Sensemattstrasse 293, CH-3147 Mittelhäusern, Switzerland
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Abstract
Vaccine design efforts against the human immunodeficiency virus (HIV) have been greatly stimulated by the observation that many infected patients eventually develop highly potent broadly neutralizing antibodies (bnAbs). Importantly, these bnAbs have evolved to recognize not only the two protein components of the viral envelope protein (Env) but also the numerous glycans that form a protective barrier on the Env protein. Because Env is heavily glycosylated compared to host glycoproteins, the glycans have become targets for the antibody response. Therefore, considerable efforts have been made in developing and validating biophysical methods to elucidate the complex structure of the Env-spike glycoprotein, with its combination of glycan and protein epitopes. We illustrate here how the application of robust biophysical methods has transformed our understanding of the structure and function of the HIV Env spike and stimulated innovation in vaccine design strategies that takes into account the essential glycan components.
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Affiliation(s)
- Max Crispin
- Centre for Biological Sciences and Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom;
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, California 92037, USA; ,
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, California 92037, USA; , .,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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18
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Rissanen I, Stass R, Zeltina A, Li S, Hepojoki J, Harlos K, Gilbert RJC, Huiskonen JT, Bowden TA. Structural Transitions of the Conserved and Metastable Hanta viral Glycoprotein Envelope. J Virol 2017; 91:e00378-17. [PMID: 28835498 DOI: 10.1128/JVI.00378-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 08/10/2017] [Indexed: 01/13/2023] Open
Abstract
Hantaviruses are zoonotic pathogens that cause severe hemorrhagic fever and pulmonary syndrome. The outer membrane of the hantavirus envelope displays a lattice of two glycoproteins, Gn and Gc, which orchestrate host cell recognition and entry. Here, we describe the crystal structure of the Gn glycoprotein ectodomain from the Asiatic Hantaan virus (HTNV), the most prevalent pathogenic hantavirus. Structural overlay analysis reveals that the HTNV Gn fold is highly similar to the Gn of Puumala virus (PUUV), a genetically and geographically distinct and less pathogenic hantavirus found predominantly in northeastern Europe, confirming that the hantaviral Gn fold is architecturally conserved across hantavirus clades. Interestingly, HTNV Gn crystallized at acidic pH, in a compact tetrameric configuration distinct from the organization at neutral pH. Analysis of the Gn, both in solution and in the context of the virion, confirms the pH-sensitive oligomeric nature of the glycoprotein, indicating that the hantaviral Gn undergoes structural transitions during host cell entry. These data allow us to present a structural model for how acidification during endocytic uptake of the virus triggers the dissociation of the metastable Gn-Gc lattice to enable insertion of the Gc-resident hydrophobic fusion loops into the host cell membrane. Together, these data reveal the dynamic plasticity of the structurally conserved hantaviral surface. IMPORTANCE Although outbreaks of Korean hemorrhagic fever were first recognized during the Korean War (1950 to 1953), it was not until 1978 that they were found to be caused by Hantaan virus (HTNV), the most prevalent pathogenic hantavirus. Here, we describe the crystal structure of HTNV envelope glycoprotein Gn, an integral component of the Gn-Gc glycoprotein spike complex responsible for host cell entry. HTNV Gn is structurally conserved with the Gn of a genetically and geographically distal hantavirus, Puumala virus, indicating that the observed α/β fold is well preserved across the Hantaviridae family. The combination of our crystal structure with solution state analysis of recombinant protein and electron cryo-microscopy of acidified hantavirus allows us to propose a model for endosome-induced reorganization of the hantaviral glycoprotein lattice. This provides a molecular-level rationale for the exposure of the hydrophobic fusion loops on the Gc, a process required for fusion of viral and cellular membranes.
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Abstract
Viruses are obligate intracellular parasites that utilize cellular machinery for many aspects of their replication cycles. Enveloped viruses generally rely upon host vesicular trafficking machinery to direct their structural proteins and genomes to sites of virus replication, assembly, and budding. Rab GTPases have been implicated in the replication of many important viral pathogens infecting humans. This review provides a summary of virus-Rab protein interactions, with a particular focus on the role of Rab-related trafficking pathways on late events in the lifecycle of herpesviruses and of HIV-1.
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Affiliation(s)
- Paul Spearman
- a Infectious Diseases, Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA
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20
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Franci G, Falanga A, Zannella C, Folliero V, Martora F, Galdiero M, Galdiero S, Morelli G, Galdiero M. Infectivity inhibition by overlapping synthetic peptides derived from the gH/gL heterodimer of herpes simplex virus type 1. J Pept Sci 2017; 23:311-319. [PMID: 28194842 PMCID: PMC7168125 DOI: 10.1002/psc.2979] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 01/13/2017] [Accepted: 01/16/2017] [Indexed: 01/27/2023]
Abstract
Herpes simplex virus (HSV) is a human pathogen that infects epithelial cells. The cutaneous lesions, caused by the virus, spread to the nervous system creating several complications. Fusion of host membranes with the viral envelope is mandatory and mediated by a group of glycoproteins conserved in all Herpesviridae subfamilies, such as the glycoproteins B (gB), H (gH), L (gL) and D (gD). We investigated the inhibitory activity mediated by synthetic overlapping peptides spanning the entire ectodomains of gH and gL glycoproteins. We have performed a brute analysis of the complete gH/gL heterodimer in order to explore the inhibitory activity of peptides modelled on these glycoproteins against HSV‐1 infection. Twenty‐four of the gH peptides at a concentration of 150 μM reached the 50% of inhibition cut‐off. Interestingly, they are mainly located in the gH carboxy‐terminal domain. None of the gL peptides had a clear inhibiting effect. No peptide toxicity was observed by lactate dehydrogenase assay at the concentrations used in our experimental conditions. HSV‐1 therapy is based on acyclovir treatment, but some resistant strains are emerging. In this scenario, innovative approaches for HSV‐1 treatment are necessary. Our data support the direct involvement of the described domains in the process of virus penetration; therefore, these results are of relevance to the potential development of novel therapeutic compounds to prevent HSV‐1 infections. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
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Affiliation(s)
- Gianluigi Franci
- Department of Experimental MedicineUniversity of Campania “Luigi Vanvitelli”Via De Crecchio 780138NaplesItaly
- Centro Interuniversitario di Ricerca sui Peptidi BioattiviUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
| | - Annarita Falanga
- Centro Interuniversitario di Ricerca sui Peptidi BioattiviUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
- Department of PharmacyUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
| | - Carla Zannella
- Department of Experimental MedicineUniversity of Campania “Luigi Vanvitelli”Via De Crecchio 780138NaplesItaly
| | - Veronica Folliero
- Department of Experimental MedicineUniversity of Campania “Luigi Vanvitelli”Via De Crecchio 780138NaplesItaly
| | - Francesca Martora
- Department of Experimental MedicineUniversity of Campania “Luigi Vanvitelli”Via De Crecchio 780138NaplesItaly
| | - Marilena Galdiero
- Department of Experimental MedicineUniversity of Campania “Luigi Vanvitelli”Via De Crecchio 780138NaplesItaly
| | - Stefania Galdiero
- Centro Interuniversitario di Ricerca sui Peptidi BioattiviUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
| | - Giancarlo Morelli
- Centro Interuniversitario di Ricerca sui Peptidi BioattiviUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
- Department of PharmacyUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
| | - Massimiliano Galdiero
- Department of Experimental MedicineUniversity of Campania “Luigi Vanvitelli”Via De Crecchio 780138NaplesItaly
- Centro Interuniversitario di Ricerca sui Peptidi BioattiviUniversity of Naples ‘Federico II’Via Mezzocannone 1680134NaplesItaly
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García-Valtanen P, Ortega-Villaizán MDM, Martínez-López A, Medina-Gali R, Pérez L, Mackenzie S, Figueras A, Coll JM, Estepa A. Autophagy-inducing peptides from mammalian VSV and fish VHSV rhabdoviral G glycoproteins (G) as models for the development of new therapeutic molecules. Autophagy 2014; 10:1666-80. [PMID: 25046110 PMCID: PMC4206542 DOI: 10.4161/auto.29557] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
It has not been elucidated whether or not autophagy is induced by rhabdoviral G glycoproteins (G) in vertebrate organisms for which rhabdovirus infection is lethal. Our work provides the first evidence that both mammalian (vesicular stomatitis virus, VSV) and fish (viral hemorrhagic septicemia virus, VHSV, and spring viremia carp virus, SVCV) rhabdoviral Gs induce an autophagic antiviral program in vertebrate cell lines. The transcriptomic profiles obtained from zebrafish genetically immunized with either Gsvcv or Gvhsv suggest that autophagy is induced shortly after immunization and therefore, it may be an important component of the strong antiviral immune responses elicited by these viral proteins. Pepscan mapping of autophagy-inducing linear determinants of Gvhsv and Gvsv showed that peptides located in their fusion domains induce autophagy. Altogether these results suggest that strategies aimed at modulating autophagy could be used for the prevention and treatment of rhabdoviral infections such as rabies, which causes thousands of human deaths every year.
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Affiliation(s)
| | | | | | | | - Luis Pérez
- IBMC; Miguel Hernández University; Elche, Spain
| | - Simon Mackenzie
- Institute of Aquaculture; University of Stirling; Stirling, UK
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Abstract
In human and non-human primates, filoviruses (Ebola and Marburg viruses) cause severe hemorrhagic fever. Recently, other animals such as pigs and some species of fruit bats have also been shown to be susceptible to these viruses. While having a preference for some cell types such as hepatocytes, endothelial cells, dendritic cells, monocytes, and macrophages, filoviruses are known to be pantropic in infection of primates. The envelope glycoprotein (GP) is responsible for both receptor binding and fusion of the virus envelope with the host cell membrane. It has been demonstrated that filovirus GP interacts with multiple molecules for entry into host cells, whereas none of the cellular molecules so far identified as a receptor/co-receptor fully explains filovirus tissue tropism and host range. Available data suggest that the mucin-like region (MLR) on GP plays an important role in attachment to the preferred target cells, whose infection is likely involved in filovirus pathogenesis, whereas the MLR is not essential for the fundamental function of the GP in viral entry into cells in vitro. Further studies elucidating the mechanisms of cellular entry of filoviruses may shed light on the development of strategies for prophylaxis and treatment of Ebola and Marburg hemorrhagic fevers.
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Affiliation(s)
- Ayato Takada
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University Sapporo, Japan
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23
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Abstract
Viral glycoproteins fold and oligomerize in the endoplasmic reticulum of the host cell. They employ the cellular machinery and receive assistance from cellular folding factors. During the folding process, they are retained in the compartment and their structural quality is checked by the quality control system of the endoplasmic reticulum. A special characteristic that distinguishes viral fusion proteins from most cellular proteins is the extensive conformational change they undergo during fusion of the viral and cellular membrane. Many viral proteins fold in conjunction with and dependent on a viral partner protein, sometimes even synthesized from the same mRNA. Relevant for folding is that viral glycoproteins from the same or related virus families may consist of overlapping sets of domain modules. The consequences of these features for viral protein folding are at the heart of this review.
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Affiliation(s)
- I Braakman
- Department of Bio-Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands.
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