1
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Mai LD, Wimberley SC, Champion JA. Intracellular delivery strategies using membrane-interacting peptides and proteins. NANOSCALE 2024; 16:15465-15480. [PMID: 39091235 PMCID: PMC11340348 DOI: 10.1039/d4nr02093f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 07/22/2024] [Indexed: 08/04/2024]
Abstract
While the cellular cytosol and organelles contain attractive targets for disease treatments, it remains a challenge to deliver therapeutic biomacromolecules to these sites. This is due to the selective permeability of the plasma and endosomal membranes, especially for large and hydrophilic therapeutic cargos such as proteins and nucleic acids. In response, many different delivery systems and molecules have been devised to help therapeutics cross these barriers to reach cytosolic targets. Among them are peptide and protein-based systems, which have several advantages over other natural and synthetic materials including their ability to interact with cell membranes. In this review, we will describe recent advances and current challenges of peptide and protein strategies that leverage cell membrane association and modulation to enable cytosolic delivery of biomacromolecule cargo. The approaches covered here include peptides and proteins derived from or inspired by natural sequences as well as those designed de novo for delivery function.
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Affiliation(s)
- Linh D Mai
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 950 Atlantic Dr NW, Atlanta, GA, 30332-2000, USA.
| | - Sydney C Wimberley
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 950 Atlantic Dr NW, Atlanta, GA, 30332-2000, USA.
- BioEngineering Program, Georgia Institute of Technology, USA
| | - Julie A Champion
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 950 Atlantic Dr NW, Atlanta, GA, 30332-2000, USA.
- BioEngineering Program, Georgia Institute of Technology, USA
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2
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Odchimar NMO, Macalalad MAB, Orosco FL. From antibiotic to antiviral: computational screening reveals a multi-targeting antibiotic from Streptomyces spp. against Nipah virus fusion proteins. Mol Divers 2024:10.1007/s11030-024-10932-7. [PMID: 39060858 DOI: 10.1007/s11030-024-10932-7] [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: 03/26/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024]
Abstract
Nipah Virus is a re-emerging zoonotic paramyxovirus that poses a significant threat to both swine industry and human health. The pursuit of potential antiviral agents with both preventive and therapeutic properties holds promise for targeting such viruses. To expedite this search, leveraging computational biology is essential. Streptomyces is renowned for its capacity to produce large and diverse metabolites with promising bioactivities. In the current study, we conducted a comprehensive structure-based virtual screening of 6524 Streptomyces spp. metabolites sourced from the StreptomeDB database to evaluate their potential inhibitory effects on three Nipah virus fusion (NiVF) protein conformations: NiVF pre-fusion 1-mer (NiVF-1mer), pre-fusion 3-mer (NiVF-3mer), and NiVF post-fusion (NiVF-PoF). Prior to virtual screening, the drug-likeness of Streptomyces spp. compounds was profiled using ADMET properties. From the 913 ADMET-filtered compounds, the subsequent targeted and confirmatory blind docking analysis revealed that S896 or virginiamycin M1, a known macrolide antibiotic, showed a maximum binding affinity with the NiVF proteins, suggesting a multi-targeting inhibitory property. In addition, the 200-ns molecular dynamics simulation and MM/PBSA analyses revealed stable and strong binding affinity between the NiVF-S896 complexes, indicating favorable interactions between S896 and the target proteins. These findings suggest the potential of virginiamycin M1, an antibiotic, as a promising multi-targeting antiviral drug. However, in vitro and in vivo experimental validations are necessary to assess their safety and efficacy.
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Affiliation(s)
- Nyzar Mabeth O Odchimar
- Virology and Vaccine Research and Development Program, Department of Science and Technology - Industrial Technology Development Institute, 1631, Taguig City, Metro Manila, Philippines
| | - Mark Andrian B Macalalad
- Virology and Vaccine Research and Development Program, Department of Science and Technology - Industrial Technology Development Institute, 1631, Taguig City, Metro Manila, Philippines
| | - Fredmoore L Orosco
- Virology and Vaccine Research and Development Program, Department of Science and Technology - Industrial Technology Development Institute, 1631, Taguig City, Metro Manila, Philippines.
- S&T Fellows Program, Department of Science and Technology, 1631, Taguig City, Metro Manila, Philippines.
- Department of Biology, College of Arts and Sciences, University of the Philippines - Manila, 1000, Manila, Metro Manila, Philippines.
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3
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Kephart SM, Hom N, Lee KK. Visualizing intermediate stages of viral membrane fusion by cryo-electron tomography. Trends Biochem Sci 2024:S0968-0004(24)00160-9. [PMID: 39054240 DOI: 10.1016/j.tibs.2024.06.012] [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: 03/06/2024] [Revised: 06/07/2024] [Accepted: 06/18/2024] [Indexed: 07/27/2024]
Abstract
Protein-mediated membrane fusion is the dynamic process where specialized protein machinery undergoes dramatic conformational changes that drive two membrane bilayers together, leading to lipid mixing and opening of a fusion pore between previously separate membrane-bound compartments. Membrane fusion is an essential stage of enveloped virus entry that results in viral genome delivery into host cells. Recent studies applying cryo-electron microscopy techniques in a time-resolved fashion provide unprecedented glimpses into the interaction of viral fusion proteins and membranes, revealing fusion intermediate states from the initiation of fusion to release of the viral genome. In combination with complementary structural, biophysical, and computation modeling approaches, these advances are shedding new light on the mechanics and dynamics of protein-mediated membrane fusion.
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Affiliation(s)
- Sally M Kephart
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Nancy Hom
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA; Biological Structure Physics and Design Graduate Program, University of Washington, Seattle, WA, USA.
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4
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Vaknin A, Grossman A, Durham ND, Lupovitz I, Goren S, Golani G, Roichman Y, Munro JB, Sorkin R. Ebola Virus Glycoprotein Strongly Binds to Membranes in the Absence of Receptor Engagement. ACS Infect Dis 2024; 10:1590-1601. [PMID: 38684073 PMCID: PMC11091876 DOI: 10.1021/acsinfecdis.3c00622] [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: 11/15/2023] [Revised: 04/07/2024] [Accepted: 04/09/2024] [Indexed: 05/02/2024]
Abstract
Ebola virus (EBOV) is an enveloped virus that must fuse with the host cell membrane in order to release its genome and initiate infection. This process requires the action of the EBOV envelope glycoprotein (GP), encoded by the virus, which resides in the viral envelope and consists of a receptor binding subunit, GP1, and a membrane fusion subunit, GP2. Despite extensive research, a mechanistic understanding of the viral fusion process is incomplete. To investigate GP-membrane association, a key step in the fusion process, we used two approaches: high-throughput measurements of single-particle diffusion and single-molecule measurements with optical tweezers. Using these methods, we show that the presence of the endosomal Niemann-Pick C1 (NPC1) receptor is not required for primed GP-membrane binding. In addition, we demonstrate this binding is very strong, likely attributed to the interaction between the GP fusion loop and the membrane's hydrophobic core. Our results also align with previously reported findings, emphasizing the significance of acidic pH in the protein-membrane interaction. Beyond Ebola virus research, our approach provides a powerful toolkit for studying other protein-membrane interactions, opening new avenues for a better understanding of protein-mediated membrane fusion events.
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Affiliation(s)
- Alisa Vaknin
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Alon Grossman
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Natasha D. Durham
- Department
of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
| | - Inbal Lupovitz
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shahar Goren
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Gonen Golani
- Department
of Physics and Haifa Research Center for Theoretical Physics and Astrophysics, University of Haifa, Haifa 3498838, Israel
| | - Yael Roichman
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- Raymond
and Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
| | - James B. Munro
- Department
of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
- Department
of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
| | - Raya Sorkin
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
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5
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Tam EH, Peng Y, Cheah MXY, Yan C, Xiao T. Neutralizing antibodies to block viral entry and for identification of entry inhibitors. Antiviral Res 2024; 224:105834. [PMID: 38369246 DOI: 10.1016/j.antiviral.2024.105834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/01/2024] [Accepted: 02/07/2024] [Indexed: 02/20/2024]
Abstract
Neutralizing antibodies (NAbs) are naturally produced by our immune system to combat viral infections. Clinically, neutralizing antibodies with potent efficacy and high specificity have been extensively used to prevent and treat a wide variety of viral infections, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Human Immunodeficiency Virus (HIV), Dengue Virus (DENV) and Hepatitis B Virus (HBV). An overwhelmingly large subset of clinically effective NAbs operates by targeting viral envelope proteins to inhibit viral entry into the host cell. Binding of viral envelope protein to the host receptor is a critical rate limiting step triggering a cascade of downstream events, including endocytosis, membrane fusion and pore formation to allow viral entry. In recent years, improved structural knowledge on these processes have allowed researchers to also leverage NAbs as an indispensable tool in guiding discovery of novel antiviral entry inhibitors, providing drug candidates with high efficacy and pan-genus specificity. This review will summarize the latest progresses on the applications of NAbs as effective entry inhibitors and as important tools to develop antiviral therapeutics by high-throughput drug screenings, rational design of peptidic entry inhibitor mimicking NAbs and in silico computational modeling approaches.
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Affiliation(s)
- Ee Hong Tam
- School of Biological Sciences, Nanyang Technological University 637551, Singapore; Institute of Structural Biology, Nanyang Technological University 636921, Singapore
| | - Yu Peng
- School of Biological Sciences, Nanyang Technological University 637551, Singapore; Institute of Structural Biology, Nanyang Technological University 636921, Singapore
| | - Megan Xin Yan Cheah
- Institute of Molecular and Cell Biology, A*STAR (Agency of Science, Technology and Research) 138673, Singapore
| | - Chuan Yan
- Institute of Molecular and Cell Biology, A*STAR (Agency of Science, Technology and Research) 138673, Singapore
| | - Tianshu Xiao
- School of Biological Sciences, Nanyang Technological University 637551, Singapore; Institute of Structural Biology, Nanyang Technological University 636921, Singapore.
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6
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Kao CF, Liu CY, Hsieh CL, Carillo KJD, Tzou DLM, Wang HC, Chang W. Structural and functional analyses of viral H2 protein of the vaccinia virus entry fusion complex. J Virol 2023; 97:e0134323. [PMID: 37975688 PMCID: PMC10734489 DOI: 10.1128/jvi.01343-23] [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: 08/29/2023] [Accepted: 10/02/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Vaccinia virus infection requires virus-cell membrane fusion to complete entry during endocytosis; however, it contains a large viral fusion protein complex of 11 viral proteins that share no structure or sequence homology to all the known viral fusion proteins, including type I, II, and III fusion proteins. It is thus very challenging to investigate how the vaccinia fusion complex works to trigger membrane fusion with host cells. In this study, we crystallized the ectodomain of vaccinia H2 protein, one component of the viral fusion complex. Furthermore, we performed a series of mutational, biochemical, and molecular analyses and identified two surface loops containing 170LGYSG174 and 125RRGTGDAW132 as the A28-binding region. We also showed that residues in the N-terminal helical region (amino acids 51-90) are also important for H2 function.
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Affiliation(s)
- Chi-Fei Kao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Chang-Yi Liu
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Chia-Lin Hsieh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | | | - Hao-Ching Wang
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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7
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Lozada C, Gonzalez S, Agniel R, Hindie M, Manciocchi L, Mazzanti L, Ha-Duong T, Santoro F, Carotenuto A, Ballet S, Lubin-Germain N. Introduction of constrained Trp analogs in RW9 modulates structure and partition in membrane models. Bioorg Chem 2023; 139:106731. [PMID: 37480815 DOI: 10.1016/j.bioorg.2023.106731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/28/2023] [Accepted: 07/10/2023] [Indexed: 07/24/2023]
Abstract
Over the past decades, many cell-penetrating peptides (CPP) have been studied for their capacity to cross cellular membranes, mostly in order to improve cellular uptake of therapeutic agents. Even though hydrophobic and anionic CPPs have been described, many of them are polycationic, due to the presence of several arginine (Arg) residues. Noteworthy, however, the presence of aromatic amino acids such as tryptophan (Trp) within CPPs seems to play an important role to reach high membranotropic activity. RW9 (RRWWRRWRR) is a designed CPP derived from the polyarginine R9 presenting both features. In general, when interacting with membranes, CPPs adopt an optimal conformation for membrane interactions - an amphipathic helical secondary structure in the case of RW9. Herein, we assumed that the incorporation of a locally constrained amino acid in the peptide sequence could improve the membranotropic activity of RW9, by facilitating its structuration upon contact with a membrane, while leaving a certain plasticity. Therefore, two cyclized Trp derivatives (Tcc and Aia) were synthesized to be incorporated in RW9 as surrogates of Trp residues. Thus, a series of peptides containing these building blocks has been synthesized by varying the type, position, and number of modifications. The membranotropic activity of the RW9 analogs was studied by spectrofluorescence titration of the peptides in presence of liposomes (DMPG), allowing to calculate partition coefficients (Kp). Our results indicate that the partitioning of the modified peptides depends on the type, the number and the position of the modification, with the best sequence being [Aia4]RW9. Interestingly, both NMR analysis and molecular dynamic (MD) simulations indicate that this analog presents an extended conformation similar to the native RW9, but with a much-reduced structural flexibility. Finally, cell internalization properties were also confirmed by confocal microscopy.
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Affiliation(s)
- Camille Lozada
- CNRS, BioCIS, CY Cergy-Paris Université, 95000 Neuville sur Oise, France; CNRS, BioCIS, Université Paris-Saclay, 92290 Châtenay-Malabry, France; Research Group of Organic Chemistry, Vrije Universiteit Brussel, Brussels, Belgium
| | - Simon Gonzalez
- CNRS, BioCIS, CY Cergy-Paris Université, 95000 Neuville sur Oise, France; CNRS, BioCIS, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - Rémy Agniel
- ERRMECe, Institut des Matériaux I-MAT (FD4122), CY Cergy Paris Université, 95000 Neuville sur Oise, France
| | - Mathilde Hindie
- ERRMECe, Institut des Matériaux I-MAT (FD4122), CY Cergy Paris Université, 95000 Neuville sur Oise, France
| | - Luca Manciocchi
- CNRS, BioCIS, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - Liuba Mazzanti
- CNRS, BioCIS, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - Tap Ha-Duong
- CNRS, BioCIS, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - Federica Santoro
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy
| | - Alfonso Carotenuto
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy
| | - Steven Ballet
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Nadège Lubin-Germain
- CNRS, BioCIS, CY Cergy-Paris Université, 95000 Neuville sur Oise, France; CNRS, BioCIS, Université Paris-Saclay, 92290 Châtenay-Malabry, France.
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8
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Ali H, Naseem A, Siddiqui ZI. SARS-CoV-2 Syncytium under the Radar: Molecular Insights of the Spike-Induced Syncytia and Potential Strategies to Limit SARS-CoV-2 Replication. J Clin Med 2023; 12:6079. [PMID: 37763019 PMCID: PMC10531702 DOI: 10.3390/jcm12186079] [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: 08/04/2023] [Revised: 09/14/2023] [Accepted: 09/17/2023] [Indexed: 09/29/2023] Open
Abstract
SARS-CoV-2 infection induces non-physiological syncytia when its spike fusogenic protein on the surface of the host cells interacts with the ACE2 receptor on adjacent cells. Spike-induced syncytia are beneficial for virus replication, transmission, and immune evasion, and contribute to the progression of COVID-19. In this review, we highlight the properties of viral fusion proteins, mainly the SARS-CoV-2 spike, and the involvement of the host factors in the fusion process. We also highlight the possible use of anti-fusogenic factors as an antiviral for the development of therapeutics against newly emerging SARS-CoV-2 variants and how the fusogenic property of the spike could be exploited for biomedical applications.
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Affiliation(s)
- Hashim Ali
- Department of Pathology, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 0QQ, UK
| | - Asma Naseem
- Infection, Immunity and Inflammation Research and Teaching Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1DZ, UK
| | - Zaheenul Islam Siddiqui
- Diabetes and Obesity Research Center, NYU Grossman Long Island School of Medicine, New York, NY 11501, USA
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9
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Cadena-Cruz C, Villarreal Camacho JL, De Ávila-Arias M, Hurtado-Gomez L, Rodriguez A, San-Juan-Vergara H. Respiratory syncytial virus entry mechanism in host cells: A general overview. Mol Microbiol 2023; 120:341-350. [PMID: 37537859 DOI: 10.1111/mmi.15133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 08/05/2023]
Abstract
Respiratory syncytial virus (RSV) is a virus that causes acute respiratory infections in neonates and older adults. To infect host cells, the attachment glycoprotein (G) interacts with a cell surface receptor. This interaction determines the specific cell types that are susceptible to infection. RSV possesses a type I fusion protein F. Type I fusion proteins are metastable when rearrangement of the prefusion F occurs; the fusion peptide is exposed transforming the protein into postfusion form. The transition between the prefusion form and its postfusion form facilitates the viral envelope and the host cell membrane to fuse, enabling the virus to enter the host cell. Understanding the entry mechanism employed by RSV is crucial for developing effective antiviral therapies. In this review, we will discuss the various types of viral fusion proteins and explore the potential entry mechanisms utilized by RSV. A deeper understanding of these mechanisms will provide valuable insights for the development of novel approaches to treat RSV infections.
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Affiliation(s)
- C Cadena-Cruz
- División Ciencias de la Salud, Universidad del Norte Barranquilla, Barranquilla, Colombia
- Facultad de Ciencias de la Salud, Programa de Medicina, Universidad Libre Seccional Barranquilla, Barranquilla, Colombia
| | - J L Villarreal Camacho
- Facultad de Ciencias de la Salud, Programa de Medicina, Universidad Libre Seccional Barranquilla, Barranquilla, Colombia
| | - Marcio De Ávila-Arias
- División Ciencias de la Salud, Universidad del Norte Barranquilla, Barranquilla, Colombia
| | - Leidy Hurtado-Gomez
- División Ciencias de la Salud, Universidad del Norte Barranquilla, Barranquilla, Colombia
| | - Alexander Rodriguez
- División Ciencias de la Salud, Universidad del Norte Barranquilla, Barranquilla, Colombia
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10
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Metcalf MC, Janus BM, Yin R, Wang R, Guest JD, Pozharski E, Law M, Mariuzza RA, Toth EA, Pierce BG, Fuerst TR, Ofek G. Structure of engineered hepatitis C virus E1E2 ectodomain in complex with neutralizing antibodies. Nat Commun 2023; 14:3980. [PMID: 37407593 PMCID: PMC10322937 DOI: 10.1038/s41467-023-39659-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/22/2023] [Indexed: 07/07/2023] Open
Abstract
Hepatitis C virus (HCV) is a major global health burden as the leading causative agent of chronic liver disease and hepatocellular carcinoma. While the main antigenic target for HCV-neutralizing antibodies is the membrane-associated E1E2 surface glycoprotein, the development of effective vaccines has been hindered by complications in the biochemical preparation of soluble E1E2 ectodomains. Here, we present a cryo-EM structure of an engineered, secreted E1E2 ectodomain of genotype 1b in complex with neutralizing antibodies AR4A, HEPC74, and IGH520. Structural characterization of the E1 subunit and C-terminal regions of E2 reveal an overall architecture of E1E2 that concurs with that observed for non-engineered full-length E1E2. Analysis of the AR4A epitope within a region of E2 that bridges between the E2 core and E1 defines the structural basis for its broad neutralization. Our study presents the structure of an E1E2 complex liberated from membrane via a designed scaffold, one that maintains all essential structural features of native E1E2. The study advances the understanding of the E1E2 heterodimer structure, crucial for the rational design of secreted E1E2 antigens in vaccine development.
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Affiliation(s)
- Matthew C Metcalf
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Benjamin M Janus
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Rui Yin
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Ruixue Wang
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Johnathan D Guest
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Edwin Pozharski
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Roy A Mariuzza
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Eric A Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Brian G Pierce
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Thomas R Fuerst
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Gilad Ofek
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA.
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA.
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11
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Ströh LJ, Krey T. Structural insights into hepatitis C virus neutralization. Curr Opin Virol 2023; 60:101316. [DOI: 10.1016/j.coviro.2023.101316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/12/2023] [Indexed: 03/31/2023]
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12
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Cellular electrical impedance to profile SARS-CoV-2 fusion inhibitors and to assess the fusogenic potential of spike mutants. Antiviral Res 2023; 213:105587. [PMID: 36977434 PMCID: PMC10040089 DOI: 10.1016/j.antiviral.2023.105587] [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: 01/31/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 03/28/2023]
Abstract
Despite the vaccination campaigns for COVID-19, we still cannot control the spread of SARS-CoV-2, as evidenced by the ongoing circulation of the Omicron variants of concern. This highlights the need for broad-spectrum antivirals to further combat COVID-19 and to be prepared for a new pandemic with a (re-)emerging coronavirus. An interesting target for antiviral drug development is the fusion of the viral envelope with host cell membranes, a crucial early step in the replication cycle of coronaviruses. In this study, we explored the use of cellular electrical impedance (CEI) to quantitatively monitor morphological changes in real time, resulting from cell-cell fusion elicited by SARS-CoV-2 spike. The impedance signal in CEI-quantified cell-cell fusion correlated with the expression level of SARS-CoV-2 spike in transfected HEK293T cells. For antiviral assessment, we validated the CEI assay with the fusion inhibitor EK1 and measured a concentration-dependent inhibition of SARS-CoV-2 spike mediated cell-cell fusion (IC50 value of 0.13 μM). In addition, CEI was used to confirm the fusion inhibitory activity of the carbohydrate-binding plant lectin UDA against SARS-CoV-2 (IC50 value of 0.55 μM), which complements prior in-house profiling activities. Finally, we explored the utility of CEI in quantifying the fusogenic potential of mutant spike proteins and in comparing the fusion efficiency of SARS-CoV-2 variants of concern. In summary, we demonstrate that CEI is a powerful and sensitive technology that can be applied to studying the fusion process of SARS-CoV-2 and to screening and characterizing fusion inhibitors in a label-free and non-invasive manner.
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Hogan V, Johnson WE. Unique Structure and Distinctive Properties of the Ancient and Ubiquitous Gamma-Type Envelope Glycoprotein. Viruses 2023; 15:v15020274. [PMID: 36851488 PMCID: PMC9967133 DOI: 10.3390/v15020274] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/13/2023] [Accepted: 01/15/2023] [Indexed: 01/20/2023] Open
Abstract
After the onset of the AIDS pandemic, HIV-1 (genus Lentivirus) became the predominant model for studying retrovirus Env glycoproteins and their role in entry. However, HIV Env is an inadequate model for understanding entry of viruses in the Alpharetrovirus, Gammaretrovirus and Deltaretrovirus genera. For example, oncogenic model system viruses such as Rous sarcoma virus (RSV, Alpharetrovirus), murine leukemia virus (MLV, Gammaretrovirus) and human T-cell leukemia viruses (HTLV-I and HTLV-II, Deltaretrovirus) encode Envs that are structurally and functionally distinct from HIV Env. We refer to these as Gamma-type Envs. Gamma-type Envs are probably the most widespread retroviral Envs in nature. They are found in exogenous and endogenous retroviruses representing a broad spectrum of vertebrate hosts including amphibians, birds, reptiles, mammals and fish. In endogenous form, gamma-type Envs have been evolutionarily coopted numerous times, most notably as placental syncytins (e.g., human SYNC1 and SYNC2). Remarkably, gamma-type Envs are also found outside of the Retroviridae. Gp2 proteins of filoviruses (e.g., Ebolavirus) and snake arenaviruses in the genus Reptarenavirus are gamma-type Env homologs, products of ancient recombination events involving viruses of different Baltimore classes. Distinctive hallmarks of gamma-type Envs include a labile disulfide bond linking the surface and transmembrane subunits, a multi-stage attachment and fusion mechanism, a highly conserved (but poorly understood) "immunosuppressive domain", and activation by the viral protease during virion maturation. Here, we synthesize work from diverse retrovirus model systems to illustrate these distinctive properties and to highlight avenues for further exploration of gamma-type Env structure and function.
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The Cellular Characterization of SARS-CoV-2 Spike Protein in Virus-Infected Cells Using the Receptor Binding Domain Binding Specific Human Monoclonal Antibodies. J Virol 2022; 96:e0045522. [PMID: 35727030 PMCID: PMC9278116 DOI: 10.1128/jvi.00455-22] [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] [Indexed: 11/20/2022] Open
Abstract
A human monoclonal antibody panel (PD4, PD5, PD7, SC23, and SC29) was isolated from the B cells of convalescent patients and used to examine the S protein in SARS-CoV-2-infected cells. While all five antibodies bound conformational-specific epitopes within SARS-CoV-2 spike (S) protein, only PD5, PD7, and SC23 were able to bind to the receptor binding domain (RBD). Immunofluorescence microscopy was used to examine the S protein RBD in cells infected with the Singapore isolates SARS-CoV-2/0334 and SARS-CoV-2/1302. The RBD-binders exhibited a distinct cytoplasmic staining pattern that was primarily localized within the Golgi complex and was distinct from the diffuse cytoplasmic staining pattern exhibited by the non-RBD-binders (PD4 and SC29). These data indicated that the S protein adopted a conformation in the Golgi complex that enabled the RBD recognition by the RBD-binders. The RBD-binders also recognized the uncleaved S protein, indicating that S protein cleavage was not required for RBD recognition. Electron microscopy indicated high levels of cell-associated virus particles, and multiple cycle virus infection using RBD-binder staining provided evidence for direct cell-to-cell transmission for both isolates. Although similar levels of RBD-binder staining were demonstrated for each isolate, SARS-CoV-2/1302 exhibited slower rates of cell-to-cell transmission. These data suggest that a conformational change in the S protein occurs during its transit through the Golgi complex that enables RBD recognition by the RBD-binders and suggests that these antibodies can be used to monitor S protein RBD formation during the early stages of infection. IMPORTANCE The SARS-CoV-2 spike (S) protein receptor binding domain (RBD) mediates the attachment of SARS-CoV-2 to the host cell. This interaction plays an essential role in initiating virus infection, and the S protein RBD is therefore a focus of therapeutic and vaccine interventions. However, new virus variants have emerged with altered biological properties in the RBD that can potentially negate these interventions. Therefore, an improved understanding of the biological properties of the RBD in virus-infected cells may offer future therapeutic strategies to mitigate SARS- CoV-2 infection. We used physiologically relevant antibodies that were isolated from the B cells of convalescent COVID-19 patients to monitor the RBD in cells infected with SARS-CoV-2 clinical isolates. These immunological reagents specifically recognize the correctly folded RBD and were used to monitor the appearance of the RBD in SARS-CoV-2-infected cells and identified the site where the RBD first appears.
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Abstract
Antibodies have been used to prevent or treat viral infections since the nineteenth century, but the full potential to use passive immunization for infectious diseases has yet to be realized. The advent of efficient methods for isolating broad and potently neutralizing human monoclonal antibodies is enabling us to develop antibodies with unprecedented activities. The discovery of IgG Fc region modifications that extend antibody half-life in humans to three months or more suggests that antibodies could become the principal tool with which we manage future viral epidemics. Antibodies for members of most virus families that cause severe disease in humans have been isolated, and many of them are in clinical development, an area that has accelerated during the effort to prevent or treat COVID-19 (coronavirus disease 2019). Broad and potently neutralizing antibodies are also important research reagents for identification of protective epitopes that can be engineered into active vaccines through structure-based reverse vaccinology. Expected final online publication date for the Annual Review of Immunology, Volume 40 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- James E Crowe
- Vanderbilt Vaccine Center, Department of Pediatrics, and Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA;
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