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Zhang Z, Takenaga T, Fehling SK, Igarashi M, Hirokawa T, Muramoto Y, Yamauchi K, Onishi C, Nakano M, Urata S, Groseth A, Strecker T, Noda T. Hexestrol, an estrogen receptor agonist, inhibits Lassa virus entry. J Virol 2024:e0071424. [PMID: 38809021 DOI: 10.1128/jvi.00714-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 05/03/2024] [Indexed: 05/30/2024] Open
Abstract
Lassa virus (LASV) is the causative agent of human Lassa fever which in severe cases manifests as hemorrhagic fever leading to thousands of deaths annually. However, no approved vaccines or antiviral drugs are currently available. Recently, we screened approximately 2,500 compounds using a recombinant vesicular stomatitis virus (VSV) expressing LASV glycoprotein GP (VSV-LASVGP) and identified a P-glycoprotein inhibitor as a potential LASV entry inhibitor. Here, we show that another identified candidate, hexestrol (HES), an estrogen receptor agonist, is also a LASV entry inhibitor. HES inhibited VSV-LASVGP replication with a 50% inhibitory concentration (IC50) of 0.63 µM. Importantly, HES also inhibited authentic LASV replication with IC50 values of 0.31 µM-0.61 µM. Time-of-addition and cell-based membrane fusion assays suggested that HES inhibits the membrane fusion step during virus entry. Alternative estrogen receptor agonists did not inhibit VSV-LASVGP replication, suggesting that the estrogen receptor itself is unlikely to be involved in the antiviral activity of HES. Generation of a HES-resistant mutant revealed that the phenylalanine at amino acid position 446 (F446) of LASVGP, which is located in the transmembrane region, conferred resistance to HES. Although mutation of F446 enhanced the membrane fusion activity of LASVGP, it exhibited reduced VSV-LASVGP replication, most likely due to the instability of the pre-fusion state of LASVGP. Collectively, our results demonstrated that HES is a promising anti-LASV drug that acts by inhibiting the membrane fusion step of LASV entry. This study also highlights the importance of the LASVGP transmembrane region as a target for anti-LASV drugs.IMPORTANCELassa virus (LASV), the causative agent of Lassa fever, is the most devastating mammarenavirus with respect to its impact on public health in West Africa. However, no approved antiviral drugs or vaccines are currently available. Here, we identified hexestrol (HES), an estrogen receptor agonist, as the potential antiviral candidate drug. We showed that the estrogen receptor itself is not involved in the antiviral activity. HES directly bound to LASVGP and blocked membrane fusion, thereby inhibiting LASV infection. Through the generation of a HES-resistant virus, we found that phenylalanine at position 446 (F446) within the LASVGP transmembrane region plays a crucial role in the antiviral activity of HES. The mutation at F446 caused reduced virus replication, likely due to the instability of the pre-fusion state of LASVGP. These findings highlight the potential of HES as a promising candidate for the development of antiviral compounds targeting LASV.
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Affiliation(s)
- Zihan Zhang
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Toru Takenaga
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | | | - Manabu Igarashi
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Takatsugu Hirokawa
- Transborder Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yukiko Muramoto
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Koji Yamauchi
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Chiho Onishi
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Masahiro Nakano
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Shuzo Urata
- National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University, Nagasaki, Japan
| | - Allison Groseth
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Thomas Strecker
- Institute of Virology, Phillips University Marburg, Marburg, Germany
| | - Takeshi Noda
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
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Raghunath G, Abbott EH, Marin M, Wu H, Reyes Ballista JM, Brindley MA, Melikyan GB. Disruption of Transmembrane Phosphatidylserine Asymmetry by HIV-1 Incorporated SERINC5 Is Not Responsible for Virus Restriction. Biomolecules 2024; 14:570. [PMID: 38785977 PMCID: PMC11118262 DOI: 10.3390/biom14050570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/26/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024] Open
Abstract
Host restriction factor SERINC5 (SER5) incorporates into the HIV-1 membrane and inhibits infectivity by a poorly understood mechanism. Recently, SER5 was found to exhibit scramblase-like activity leading to the externalization of phosphatidylserine (PS) on the viral surface, which has been proposed to be responsible for SER5's antiviral activity. This and other reports that document modulation of HIV-1 infectivity by viral lipid composition prompted us to investigate the role of PS in regulating SER5-mediated HIV-1 restriction. First, we show that the level of SER5 incorporation into virions correlates with an increase in PS levels in the outer leaflet of the viral membrane. We developed an assay to estimate the PS distribution across the viral membrane and found that SER5, but not SER2, which lacks antiviral activity, abrogates PS asymmetry by externalizing this lipid. Second, SER5 incorporation diminished the infectivity of pseudoviruses produced from cells lacking a flippase subunit CDC50a and, therefore, exhibited a higher baseline level of surface-accessible PS. Finally, exogenous manipulation of the viral PS levels utilizing methyl-alpha-cyclodextrin revealed a lack of correlation between external PS and virion infectivity. Taken together, our study implies that the increased PS exposure to SER5-containing virions itself is not directly linked to HIV-1 restriction.
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Affiliation(s)
- Gokul Raghunath
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Elizabeth H. Abbott
- Emory College of Arts and Sciences, Emory University, Atlanta, GA 30322, USA
| | - Mariana Marin
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Hui Wu
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (M.M.); (H.W.)
| | - Judith Mary Reyes Ballista
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (J.M.R.B.); (M.A.B.)
| | - Melinda A. Brindley
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; (J.M.R.B.); (M.A.B.)
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Gregory B. Melikyan
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
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3
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Nuñez IA, Crane A, Crozier I, Worwa G, Kuhn JH. Treatment of highly virulent mammarenavirus infections-status quo and future directions. Expert Opin Drug Discov 2024; 19:537-551. [PMID: 38606475 PMCID: PMC11069405 DOI: 10.1080/17460441.2024.2340494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024]
Abstract
INTRODUCTION Mammarenaviruses are negative-sense bisegmented enveloped RNA viruses that are endemic in Africa, the Americas, and Europe. Several are highly virulent, causing acute human diseases associated with high case fatality rates, and are considered to be significant with respect to public health impact or bioterrorism threat. AREAS COVERED This review summarizes the status quo of treatment development, starting with drugs that are in advanced stages of evaluation in early clinical trials, followed by promising candidate medical countermeasures emerging from bench analyses and investigational animal research. EXPERT OPINION Specific therapeutic treatments for diseases caused by mammarenaviruses remain limited to the off-label use of ribavirin and transfusion of convalescent sera. Progress in identifying novel candidate medical countermeasures against mammarenavirus infection has been slow in part because of the biosafety and biosecurity requirements. However, novel methodologies and tools have enabled increasingly efficient high-throughput molecular screens of regulatory-agency-approved small-molecule drugs and led to the identification of several compounds that could be repurposed for the treatment of infection with several mammarenaviruses. Unfortunately, most of them have not yet been evaluated in vivo. The most promising treatment under development is a monoclonal antibody cocktail that is protective against multiple lineages of the Lassa virus in nonhuman primate disease models.
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Affiliation(s)
- Ivette A. Nuñez
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
| | - Anya Crane
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
| | - Ian Crozier
- Clinical Monitoring Research Program Directorate, Frederick
National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Gabriella Worwa
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
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Katz M, Diskin R. The underlying mechanisms of arenaviral entry through matriglycan. Front Mol Biosci 2024; 11:1371551. [PMID: 38516183 PMCID: PMC10955480 DOI: 10.3389/fmolb.2024.1371551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/15/2024] [Indexed: 03/23/2024] Open
Abstract
Matriglycan, a recently characterized linear polysaccharide, is composed of alternating xylose and glucuronic acid subunits bound to the ubiquitously expressed protein α-dystroglycan (α-DG). Pathogenic arenaviruses, like the Lassa virus (LASV), hijack this long linear polysaccharide to gain cellular entry. Until recently, it was unclear through what mechanisms LASV engages its matriglycan receptor to initiate infection. Additionally, how matriglycan is synthesized onto α-DG by the Golgi-resident glycosyltransferase LARGE1 remained enigmatic. Recent structural data for LARGE1 and for the LASV spike complex informs us about the synthesis of matriglycan as well as its usage as an entry receptor by arenaviruses. In this review, we discuss structural insights into the system of matriglycan generation and eventual recognition by pathogenic viruses. We also highlight the unique usage of matriglycan as a high-affinity host receptor compared with other polysaccharides that decorate cells.
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Affiliation(s)
| | - Ron Diskin
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
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5
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Carr CR, Crawford KHD, Murphy M, Galloway JG, Haddox HK, Matsen FA, Andersen KG, King NP, Bloom JD. Deep mutational scanning reveals functional constraints and antigenic variability of Lassa virus glycoprotein complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.05.579020. [PMID: 38370709 PMCID: PMC10871245 DOI: 10.1101/2024.02.05.579020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Lassa virus is estimated to cause thousands of human deaths per year, primarily due to spillovers from its natural host, Mastomys rodents. Efforts to create vaccines and antibody therapeutics must account for the evolutionary variability of Lassa virus's glycoprotein complex (GPC), which mediates viral entry into cells and is the target of neutralizing antibodies. To map the evolutionary space accessible to GPC, we use pseudovirus deep mutational scanning to measure how nearly all GPC amino-acid mutations affect cell entry and antibody neutralization. Our experiments define functional constraints throughout GPC. We quantify how GPC mutations affect neutralization by a panel of monoclonal antibodies and show that all antibodies are escaped by mutations that exist among natural Lassa virus lineages. Overall, our work describes a biosafety-level-2 method to elucidate the mutational space accessible to GPC and shows how prospective characterization of antigenic variation could aid design of therapeutics and vaccines.
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Affiliation(s)
- Caleb R. Carr
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA 98109, USA
| | - Katharine H. D. Crawford
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA 98109, USA
| | - Michael Murphy
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Jared G. Galloway
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Hugh K. Haddox
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Frederick A. Matsen
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Department of Statistics, University of Washington, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, Seattle, WA 98109, USA
| | - Kristian G. Andersen
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Scripps Research Translational Institute, La Jolla, CA 92037, USA
| | - Neil P. King
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Jesse D. Bloom
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
- Howard Hughes Medical Institute, Seattle, WA 98109, USA
- Lead contact
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6
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Pennington H, Birtles D, Shi ZW, Lee J. A Salt Bridge and Disulfide Bond within the Lassa Virus Fusion Domain Are Required for the Initiation of Membrane Fusion. ACS OMEGA 2024; 9:4920-4930. [PMID: 38313535 PMCID: PMC10831964 DOI: 10.1021/acsomega.3c08632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/13/2023] [Accepted: 12/28/2023] [Indexed: 02/06/2024]
Abstract
Infection with Lassa virus (LASV), an Old-World arenavirus that is endemic to West Africa, causes Lassa fever, a lethal hemorrhagic fever. Delivery of LASV's genetic material into the host cell is an integral component of its lifecycle. This is accomplished via membrane fusion, a process initiated by a hydrophobic sequence known as the fusion domain (FD). The LASV FD (G260-N295) consists of two structurally distinct regions: an N-terminal fusion peptide (FP: G260-T274) and an internal fusion loop (FL: C279-N295) that is connected by a short linker region (P275-Y278). However, the molecular mechanisms behind how the LASV FD initiates fusion remain unclear. Here, we demonstrate that the LASV FD adopts a fusogenic, helical conformation at a pH akin to that of the lysosomal compartment. Additionally, we identified a conserved disulfide bond (C279 and C292) and salt bridge (R282 and E289) within the FL that are pertinent to fusion. We found that the disulfide bond must be present so that the FD can bind to the lipid bilayer and subsequently initiate fusion. Moreover, the salt bridge is essential for the secondary structure of the FD such that it can associate with the lipid bilayer in the proper orientation for full functionality. In conclusion, our findings indicate that the LASV FD preferentially initiates fusion at a pH akin to that of the lysosome through a mechanism that requires a conserved salt bridge and, to a lesser extent, an intact disulfide bond within the internal FL.
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Affiliation(s)
- Hallie
N. Pennington
- Department of Chemistry and
Biochemistry, College of Computer, Mathematics, and Natural Science, University of Maryland College Park, College Park, Maryland 20740, United States
| | - Daniel Birtles
- Department of Chemistry and
Biochemistry, College of Computer, Mathematics, and Natural Science, University of Maryland College Park, College Park, Maryland 20740, United States
| | - Zoe W. Shi
- Department of Chemistry and
Biochemistry, College of Computer, Mathematics, and Natural Science, University of Maryland College Park, College Park, Maryland 20740, United States
| | - Jinwoo Lee
- Department of Chemistry and
Biochemistry, College of Computer, Mathematics, and Natural Science, University of Maryland College Park, College Park, Maryland 20740, United States
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Keating PM, Schifano NP, Wei X, Kong MY, Lee J. pH-dependent conformational change within the Lassa virus transmembrane domain elicits efficient membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184233. [PMID: 37734457 DOI: 10.1016/j.bbamem.2023.184233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/05/2023] [Accepted: 09/16/2023] [Indexed: 09/23/2023]
Abstract
Lassa virus (LASV) is the most prevalent member of the arenavirus family and the causative agent of Lassa fever, a viral hemorrhagic fever. Although there are annual outbreaks in West Africa, and recently isolated cases worldwide, there are no current therapeutics or vaccines, which poses LASV as a significant global public health threat. One of the key steps in LASV infection is the delivery of its genetic material by fusing its viral membrane with the host cell membrane. This process is facilitated by significant conformational changes within glycoprotein 2 (GP2), yielding distinct prefusion and postfusion structural states. However, structural information is missing to understand the changes that occur in the transmembrane domain during the fusion process. Here, we used CD and NMR spectroscopy to show that the transmembrane domain has pH-dependent conformational changes that result in an extension of the alpha helix at the N-terminal end. Proline mutants of key residues in that region prevent the helical extension, as seen in CD and NMR. We developed a modified lipid mixing assay to study the importance of this extension on the function of GP2. Our assay shows that membrane fusion efficiency is optimal at low pH values but introducing the proline mutants results in lower fusion efficiency. These results indicate that these pH-dependent conformational changes are important to the fusion mechanism. This information can be used to design therapeutics to combat Lassa virus infections and prevent its potential spread.
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Affiliation(s)
- Patrick M Keating
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Nicholas P Schifano
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Xinrui Wei
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Matthew Y Kong
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Jinwoo Lee
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
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8
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Bezerra EHS, Melo-Hanchuk TD, Marques RE. Structural and molecular biology of Sabiá virus. Exp Biol Med (Maywood) 2023; 248:1624-1634. [PMID: 37937408 PMCID: PMC10723027 DOI: 10.1177/15353702231199071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023] Open
Abstract
Brazilian mammarenavirus, or Sabiá virus (SABV), is a New World (NW) arenavirus associated with fulminant hemorrhagic disease in humans and the sole biosafety level 4 microorganism ever isolated in Brazil. Since the isolation of SABV in the 1990s, studies on viral biology have been scarce, with no available countermeasures against SABV infection or disease. Here we provide a comprehensive review of SABV biology, including key aspects of SABV replication, and comparisons with related Old World and NW arenaviruses. SABV is most likely a rodent-borne virus, transmitted to humans, through exposure to urine and feces in peri-urban areas. Using protein structure prediction methods and alignments, we analyzed shared and unique features of SABV proteins (GPC, NP, Z, and L) that could be explored in search of therapeutic strategies, including repurposing intended application against arenaviruses. Highly conserved catalytic activities present in L protein could be targeted for broad-acting antiviral activity among arenaviruses, while protein-protein interactions, such as those between L and the matrix protein Z, have evolved in NW arenaviruses and should be specific to SABV. The nucleoprotein (NP) also shares targetable interaction interfaces with L and Z and exhibits exonuclease activity in the C-terminal domain, which may be involved in multiple aspects of SABV replication. Envelope glycoproteins GP1 and GP2 have been explored in the development of promising cross-reactive neutralizing antibodies and vaccines, some of which could be repurposed for SABV. GP1 remains a challenging target in SABV as evolutive pressures render it the most variable viral protein in terms of both sequence and structure, while antiviral strategies targeting the Z protein remain to be validated. In conclusion, the prediction and analysis of protein structures should revolutionize research on viruses such as SABV by facilitating the rational design of countermeasures while reducing dependence on sophisticated laboratory infrastructure for experimental validation.
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Affiliation(s)
| | | | - Rafael Elias Marques
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), São Paulo 13083-100, Brazil
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9
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Lim HT, Kok BH, Leow CY, Leow CH. Exploring shark VNAR antibody against infectious diseases using phage display technology. FISH & SHELLFISH IMMUNOLOGY 2023; 140:108986. [PMID: 37541634 DOI: 10.1016/j.fsi.2023.108986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Antibody with high affinity and specificity to antigen has widely used as a tool to combat various diseases. The variable domain of immunoglobulin new antigen receptor (VNAR) naturally found in shark contains autonomous function as single-domain antibody. Due to its excellent characteristics, the small, non-complex, and highly stable have made shark VNAR can acquires the antigen-binding capability that might not be reached by conventional antibody. Phage display technology enables shark VNAR to be presented on the surface of phage, allowing the exploration of shark VNAR as an alternative antibody format to target antigens from various infectious diseases. The application of phage-displayed shark VNAR in antibody library and biopanning eventually leads to the discovery and isolation of antigen-specific VNARs with diagnostic and therapeutic potential towards infectious diseases. This review provides an overview of the shark VNAR antibody, the types of phage display technology with comparison to the other types of display system, as well as the application and case studies of phage-displayed shark VNAR antibodies against infectious diseases.
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Affiliation(s)
- Hui Ting Lim
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Gelugor, Penang, Malaysia
| | - Boon Hui Kok
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Gelugor, Penang, Malaysia
| | - Chiuan Yee Leow
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800, Gelugor, Penang, Malaysia
| | - Chiuan Herng Leow
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Gelugor, Penang, Malaysia.
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10
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Zhang Y, York J, Brindley MA, Nunberg JH, Melikyan GB. Fusogenic structural changes in arenavirus glycoproteins are associated with viroporin activity. PLoS Pathog 2023; 19:e1011217. [PMID: 37494374 PMCID: PMC10406333 DOI: 10.1371/journal.ppat.1011217] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 08/07/2023] [Accepted: 07/04/2023] [Indexed: 07/28/2023] Open
Abstract
Many enveloped viruses enter host cells by fusing with acidic endosomes. The fusion activity of multiple viral envelope glycoproteins does not generally affect viral membrane permeability. However, fusion induced by the Lassa virus (LASV) glycoprotein complex (GPc) is always preceded by an increase in viral membrane permeability and the ensuing acidification of the virion interior. Here, systematic investigation of this LASV fusion phenotype using single pseudovirus tracking in live cells reveals that the change in membrane barrier function is associated with the fusogenic conformational reorganization of GPc. We show that a small-molecule fusion inhibitor or mutations that impair viral fusion by interfering with GPc refolding into the post-fusion structure prevent the increase in membrane permeability. We find that the increase in virion membrane permeability occurs early during endosomal maturation and is facilitated by virus-cell contact. This increase is observed using diverse arenavirus glycoproteins, whether presented on lentivirus-based pseudoviruses or arenavirus-like particles, and in multiple different cell types. Collectively, these results suggest that conformational changes in GPc triggered by low pH and cell factor binding are responsible for virion membrane permeabilization and acidification of the virion core prior to fusion. We propose that this viroporin-like activity may augment viral fusion and/or post-fusion steps of infection, including ribonucleoprotein release into the cytoplasm.
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Affiliation(s)
- You Zhang
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
| | - Joanne York
- Montana Biotechnology Center, University of Montana, Missoula, Montana, United States of America
| | - Melinda A. Brindley
- Department of Infectious Diseases, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Jack H. Nunberg
- Montana Biotechnology Center, University of Montana, Missoula, Montana, United States of America
| | - Gregory B. Melikyan
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Children’s Healthcare of Atlanta, Atlanta, Georgia, United States of America
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Schrauf S, Tomberger Y, Nambulli S, Duprex WP, Tschismarov R, Tauber E, Ramsauer K. Biodistribution and toxicology evaluation of a recombinant measles Schwarz-based Lassa vaccine in cynomolgus macaques. J Appl Toxicol 2023; 43:719-733. [PMID: 36480160 DOI: 10.1002/jat.4421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 11/25/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
MV-LASV is an investigational measles Schwarz-based vaccine for the prevention of Lassa fever. A repeated-dose toxicity study in cynomolgus macaques was performed to assess the biodistribution and local and systemic toxicological effects. Monkeys received three immunizations of MV-LASV or saline intramuscularly with a 2-week interval. An increase in anti-measles antibodies confirmed the reaction of the immune system to the vaccine backbone. Clinical observations, body weight, body temperature, local tolerance, electrocardiogram parameters, various clinical pathology parameters (hematology, coagulation urinalysis, serum chemistry, and C-reactive protein) were monitored. Gross pathology and histopathology of various tissues were evaluated. MV-LASV induced a mild increase in fibrinogen and C-reactive protein concentrations. This coincided with microscopic inflammation at the injection sites which partially or fully resolved following a 3-week recovery period. Viral RNA was found in secondary lymphoid organs and injection sites and gall bladder. No viral shedding to the environment was observed. Overall, the vaccine was locally and systemically well tolerated, supporting a first-in-human study.
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Affiliation(s)
- Sabrina Schrauf
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Yvonne Tomberger
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Sham Nambulli
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - W Paul Duprex
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Roland Tschismarov
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Erich Tauber
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
| | - Katrin Ramsauer
- Themis Bioscience GmbH, Vienna, Austria, a subsidiary of Merck & Co., Inc., Rahway, New Jersey, USA
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12
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Design, Synthesis, and Biological Evaluation of Benzimidazole Derivatives as Potential Lassa Virus Inhibitors. Molecules 2023; 28:molecules28041579. [PMID: 36838567 PMCID: PMC9963587 DOI: 10.3390/molecules28041579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 02/10/2023] Open
Abstract
The Lassa virus (LASV) causes Lassa fever, a highly infectious and lethal agent of acute viral hemorrhagic fever. At present, there are still no effective treatments available, creating an urgent need to develop novel therapeutics. Some benzimidazole compounds targeting the arenavirus envelope glycoprotein complex (GPC) are promising inhibitors of LASV. In this study, we synthesized two series of LASV inhibitors based on the benzimidazole structure. Lentiviral pseudotypes bearing the LASV GPC were established to identify virus entry inhibitors. Surface plasmon resonance (SPR) was further used to verify the binding activities of the potential compounds. Compounds 7d-Z, 7h-Z, 13c, 13d, and 13f showed relatively excellent antiviral activities with IC50 values ranging from 7.58 to 15.46 nM and their SI values above 1251. These five representative compounds exhibited stronger binding affinity with low equilibrium dissociation constants (KD < 8.25 × 10-7 M) in SPR study. The compound 7h-Z displayed the most potent antiviral activity (IC50 = 7.58 nM) with a relatively high SI value (2496), which could be further studied as a lead compound. The structure-activity relationship indicated that the compounds with lipophilic and spatially larger substituents might possess higher antiviral activity and a much larger safety margin. This study will provide some good guidance for the development of highly active compounds with a novel skeleton against LASV.
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13
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Keating PM, Pennington HN, Collins SD, Lee J. Purification and characterization of the Lassa virus transmembrane domain. Biochem Biophys Rep 2022; 33:101409. [PMID: 36583076 PMCID: PMC9792740 DOI: 10.1016/j.bbrep.2022.101409] [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: 07/01/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
Lassa virus (LASV) is the most prevalent arenavirus afflicting humans and has high potential to become a threat to global public health. The transmembrane domain (TM) of the LASV glycoprotein complex forms critical interactions with the LASV stable signal peptide that are important for the maturation and fusion activity of the virus. A further study of the structure-based molecular mechanisms is required to understand the role of the TM in the lifecycle of LASV in greater detail. However, it is challenging to obtain the TM in high quantity and purity due to its hydrophobic nature which results in solubility issues that makes it prone to aggregation in typical buffer systems. Here, we designed a purification and detergent screen protocol for the highly insoluble TM to enhance the yield and purity for structural studies. Based on the detergents tested, the TM had the highest incorporation in LMPG. Circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy were utilized to confirm the best detergent system for structural studies. Through CD spectroscopy, we were able to characterize the secondary structure of the TM as largely alpha-helical, while NMR spectroscopy showed a well-structured and stable TM in LMPG. From these results, LMPG was determined to be the optimal detergent for further structural studies.
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14
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Villalaín J. Interaction of Lassa virus fusion and membrane proximal peptides with late endosomal membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184031. [PMID: 35964711 DOI: 10.1016/j.bbamem.2022.184031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/15/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Mammarenaviruses include many significant worldwide-widespread human pathogens, among them Lassa virus (LASV), having a dramatic morbidity and mortality rate. They are a potential high-risk menace to the worldwide public health since there are no treatments and there is a high possibility of animal-to-human and human-to-human viral transmission. These viruses enter into the cells by endocytosis fusing its membrane envelope with the late endosomal membrane thanks to the glycoprotein GP2, a membrane fusion protein of class I. This protein contains different domains, among them the N-terminal fusion peptide (NFP), the internal fusion loop (IFL), the membrane proximal external region (MPER) and the transmembrane domain (TMD). All these domains are implicated in the membrane fusion process. In this work, we have used an all-atom molecular dynamics study to know the binding of these protein domains with a complex membrane mimicking the late endosome one. We show that the NFP/IFL domain is capable of spontaneously inserting into the membrane without a significant change of secondary structure, the MPER domain locates at the bilayer interface with an orientation parallel to the membrane surface and tends to interact with other MPER domains, and the TMD domain tilts inside the bilayer. Moreover, they predominantly interact with negatively charged phospholipids. Overall, these membrane-interacting domains would characterise a target that would make possible to find effective antiviral molecules against LASV in particular and Mammarenaviruses in general.
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Affiliation(s)
- José Villalaín
- Institute of Research, Development, and Innovation in Healthcare Biotechnology (IDiBE), Universitas "Miguel Hernández", E-03202 Elche-Alicante, Spain.
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15
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Birtles D, Oh AE, Lee J. Exploring the
pH
dependence of the
SARS‐CoV
‐2 complete fusion domain and the role of its unique structural features. Protein Sci 2022. [PMCID: PMC9538437 DOI: 10.1002/pro.4390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
SARS‐CoV‐2 may enter target cells through the process of membrane fusion at either the plasma (~pH 7.4–7.0) or endosomal (~pH 6.5–5.0) membrane in order to deliver its genetic information. The fusion domain (FD) of the spike glycoprotein is responsible for initiating fusion and is thus integral to the viral life cycle. The FD of SARS‐CoV‐2 is unique in that it consists of two structurally distinctive regions referred to as the fusion peptide (FP) and the fusion loop (FL); yet the molecular mechanisms behind how this FD perturbs the membrane to initiate fusion remains unclear. In this study via solution NMR, we witnessed only a slight conformational change in the FD between pH 7.4 and pH 5.0, resulting in a minor elongation of helix 1. However, we found that the FD's ability to mediate membrane fusion has a large and significant pH dependence, with fusion events being more readily induced at low pH. Interestingly, a biphasic relationship between the environmental pH and fusogenicity was discovered, suggesting a preference for the FD to initiate fusion at the late endosomal membrane. Furthermore, the conserved disulfide bond and hydrophobic motif “LLF” were found to be critical for the function of the complete FD, with minimal activity witnessed when either was perturbed. In conclusion, these findings indicate that the SARS‐CoV‐2 FD preferably initiates fusion at a pH similar to the late endosome through a mechanism that heavily relies on the internal disulfide bond of the FL and hydrophobic LLF motif within the FP.
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Affiliation(s)
- Daniel Birtles
- Department of Chemistry and Biochemistry University of Maryland College Park Maryland USA
| | - Anna E. Oh
- Department of Chemistry and Biochemistry University of Maryland College Park Maryland USA
| | - Jinwoo Lee
- Department of Chemistry and Biochemistry University of Maryland College Park Maryland USA
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