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Rotational Dynamics of The Transmembrane Domains Play an Important Role in Peptide Dynamics of Viral Fusion and Ion Channel Forming Proteins—A Molecular Dynamics Simulation Study. Viruses 2022; 14:v14040699. [PMID: 35458429 PMCID: PMC9024552 DOI: 10.3390/v14040699] [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] [Received: 02/02/2022] [Revised: 03/02/2022] [Accepted: 03/20/2022] [Indexed: 02/04/2023] Open
Abstract
Focusing on the transmembrane domains (TMDs) of viral fusion and channel-forming proteins (VCPs), experimentally available and newly generated peptides in an ideal conformation of the S and E proteins of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and SARS-CoV, gp41 and Vpu, both of human immunodeficiency virus type 1 (HIV-1), haemagglutinin and M2 of influenza A, as well as gB of herpes simplex virus (HSV), are embedded in a fully hydrated lipid bilayer and used in multi-nanosecond molecular dynamics simulations. It is aimed to identify differences in the dynamics of the individual TMDs of the two types of viral membrane proteins. The assumption is made that the dynamics of the individual TMDs are decoupled from their extra-membrane domains, and that the mechanics of the TMDs are distinct from each other due to the different mechanism of function of the two types of proteins. The diffusivity coefficient (DC) of the translational and rotational diffusion is decreased in the oligomeric state of the TMDs compared to those values when calculated from simulations in their monomeric state. When comparing the calculations for two different lengths of the TMD, a longer full peptide and a shorter purely TMD stretch, (i) the difference of the calculated DCs begins to level out when the difference exceeds approximately 15 amino acids per peptide chain, and (ii) the channel protein rotational DC is the most affected diffusion parameter. The rotational dynamics of the individual amino acids within the middle section of the TMDs of the fusion peptides remain high upon oligomerization, but decrease for the channel peptides, with an increasing number of monomers forming the oligomeric state, suggesting an entropic penalty on oligomerization for the latter.
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53
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Li L, Changrob S, Fu Y, Stovicek O, Guthmiller JJ, McGrath JJC, Dugan HL, Stamper CT, Zheng NY, Huang M, Wilson PC. Librator: a platform for the optimized analysis, design, and expression of mutable influenza viral antigens. Brief Bioinform 2022; 23:6532539. [PMID: 35183062 PMCID: PMC8921739 DOI: 10.1093/bib/bbac028] [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: 11/18/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Artificial mutagenesis and protein engineering have laid the foundation for antigenic characterization and universal vaccine design for influenza viruses. However, many methods used in this process require manual sequence editing and protein expression, limiting their efficiency and utility in high-throughput applications. More streamlined in silico tools allowing researchers to properly analyze and visualize influenza viral protein sequences with accurate nomenclature are necessary to improve antigen design and productivity. To address this need, we developed Librator, a system for analyzing and designing custom protein sequences of influenza virus hemagglutinin (HA) and neuraminidase (NA) glycoproteins. Within Librator's graphical interface, users can easily interrogate viral sequences and phylogenies, visualize antigen structures and conservation, mutate target residues and design custom antigens. Librator also provides optimized fragment design for Gibson Assembly of HA and NA expression constructs based on peptide conservation of all historical HA and NA sequences, ensuring fragments are reusable and compatible across related subtypes, thereby promoting reagent savings. Finally, the program facilitates single-cell immune profiling, epitope mapping of monoclonal antibodies and mosaic protein design. Using Librator-based antigen construction, we demonstrate that antigenicity can be readily transferred between HA molecules of H3, but not H1, lineage viruses. Altogether, Librator is a valuable tool for analyzing influenza virus HA and NA proteins and provides an efficient resource for optimizing recombinant influenza antigen synthesis.
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Affiliation(s)
| | | | | | - Olivia Stovicek
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Jenna J Guthmiller
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Joshua J C McGrath
- Gale and Ira Drukier Institute for Children's Health, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Haley L Dugan
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA
| | | | - Nai-Ying Zheng
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA,Gale and Ira Drukier Institute for Children's Health, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Min Huang
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Patrick C Wilson
- Corresponding author: Patrick C. Wilson, Drukier Institute for Children’s Health, Weill Cornell Medicine, New York, NY 10021, USA. E-mail:
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Daniels RS, Galiano M, Ermetal B, Kwong J, Lau CS, Xiang Z, McCauley JW, Lo J. Temporal and Gene Reassortment Analysis of Influenza C Virus Outbreaks in Hong Kong, SAR, China. J Virol 2022; 96:e0192821. [PMID: 34787455 PMCID: PMC8826914 DOI: 10.1128/jvi.01928-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 11/29/2022] Open
Abstract
From 2014 to week 07/2020 the Centre for Health Protection in Hong Kong conducted screening for influenza C virus (ICV). A retrospective analysis of ICV detections to week 26/2019 revealed persistent low-level circulation with outbreaks occurring biennially in the winters of 2015 to 2016 and 2017 to 2018 (R. S. Daniels et al., J Virol 94:e01051-20, 2020, https://doi.org/10.1128/JVI.01051-20). Here, we report on an outbreak occurring in 2019 to 2020, reinforcing the observation of biennial seasonality in Hong Kong. All three outbreaks occurred in similar time frames, were subsequently dwarfed by seasonal epidemics of influenza types A and B, and were caused by similar proportions of C/Kanagawa/1/76 (K)-lineage and C/São Paulo/378/82 S1- and S2-sublineage viruses. Ongoing genetic drift was observed in all genes, with some evidence of amino acid substitution in the hemagglutinin-esterase-fusion (HEF) glycoprotein possibly associated with antigenic drift. A total of 61 ICV genomes covering the three outbreaks were analyzed for reassortment, and 9 different reassortant constellations were identified, 1 K-lineage, 4 S1-sublineage, and 4 S2-sublineage, with 6 of these being identified first in the 2019-1920 outbreak (2 S2-lineage and 4 S1-lineage). The roles that virus interference/enhancement, ICV persistent infection, genome evolution, and reassortment might play in the observed seasonality of ICV in Hong Kong are discussed. IMPORTANCE Influenza C virus (ICV) infection of humans is common, with the great majority of people being infected during childhood, though reinfection can occur throughout life. While infection normally results in "cold-like" symptoms, severe disease cases have been reported in recent years. However, knowledge of ICV is limited due to poor systematic surveillance and an inability to propagate the virus in large amounts in the laboratory. Following recent systematic surveillance in Hong Kong SAR, China, and direct ICV gene sequencing from clinical specimens, a 2-year cycle of disease outbreaks (epidemics) has been identified, with gene mixing playing a significant role in ICV evolution. Studies like those reported here are key to developing an understanding of the impact of influenza C virus infection in humans, notably where comorbidities exist and severe respiratory disease can develop.
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Affiliation(s)
- Rodney S. Daniels
- Worldwide Influenza Centre, The Francis Crick Institute, London, United Kingdom
| | - Monica Galiano
- Worldwide Influenza Centre, The Francis Crick Institute, London, United Kingdom
| | - Burcu Ermetal
- Worldwide Influenza Centre, The Francis Crick Institute, London, United Kingdom
| | - Jasmine Kwong
- Centre for Health Protection, Department of Health, Hong Kong SAR, China
| | - Chi S. Lau
- Centre for Health Protection, Department of Health, Hong Kong SAR, China
| | - Zheng Xiang
- Worldwide Influenza Centre, The Francis Crick Institute, London, United Kingdom
| | - John W. McCauley
- Worldwide Influenza Centre, The Francis Crick Institute, London, United Kingdom
| | - Janice Lo
- Centre for Health Protection, Department of Health, Hong Kong SAR, China
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55
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Guthmiller JJ, Han J, Utset HA, Li L, Lan LYL, Henry C, Stamper CT, McMahon M, O'Dell G, Fernández-Quintero ML, Freyn AW, Amanat F, Stovicek O, Gentles L, Richey ST, de la Peña AT, Rosado V, Dugan HL, Zheng NY, Tepora ME, Bitar DJ, Changrob S, Strohmeier S, Huang M, García-Sastre A, Liedl KR, Bloom JD, Nachbagauer R, Palese P, Krammer F, Coughlan L, Ward AB, Wilson PC. Broadly neutralizing antibodies target a haemagglutinin anchor epitope. Nature 2022; 602:314-320. [PMID: 34942633 PMCID: PMC8828479 DOI: 10.1038/s41586-021-04356-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 12/15/2021] [Indexed: 11/09/2022]
Abstract
Broadly neutralizing antibodies that target epitopes of haemagglutinin on the influenza virus have the potential to provide near universal protection against influenza virus infection1. However, viral mutants that escape broadly neutralizing antibodies have been reported2,3. The identification of broadly neutralizing antibody classes that can neutralize viral escape mutants is critical for universal influenza virus vaccine design. Here we report a distinct class of broadly neutralizing antibodies that target a discrete membrane-proximal anchor epitope of the haemagglutinin stalk domain. Anchor epitope-targeting antibodies are broadly neutralizing across H1 viruses and can cross-react with H2 and H5 viruses that are a pandemic threat. Antibodies that target this anchor epitope utilize a highly restricted repertoire, which encodes two public binding motifs that make extensive contacts with conserved residues in the fusion peptide. Moreover, anchor epitope-targeting B cells are common in the human memory B cell repertoire and were recalled in humans by an oil-in-water adjuvanted chimeric haemagglutinin vaccine4,5, which is a potential universal influenza virus vaccine. To maximize protection against seasonal and pandemic influenza viruses, vaccines should aim to boost this previously untapped source of broadly neutralizing antibodies that are widespread in the human memory B cell pool.
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Affiliation(s)
- Jenna J Guthmiller
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA.
| | - Julianna Han
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Henry A Utset
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Lei Li
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | | | - Carole Henry
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
- Moderna Inc., Cambridge, MA, USA
| | | | - Meagan McMahon
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George O'Dell
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Monica L Fernández-Quintero
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Alec W Freyn
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Moderna Inc., Cambridge, MA, USA
| | - Fatima Amanat
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Olivia Stovicek
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Lauren Gentles
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Sara T Richey
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Alba Torrents de la Peña
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Victoria Rosado
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Haley L Dugan
- Committee on Immunology, University of Chicago, Chicago, IL, USA
| | - Nai-Ying Zheng
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Micah E Tepora
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Dalia J Bitar
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Siriruk Changrob
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Shirin Strohmeier
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Min Huang
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- The Tisch Cancer Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Klaus R Liedl
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Jesse D Bloom
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Raffael Nachbagauer
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Moderna Inc., Cambridge, MA, USA
| | - Peter Palese
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Florian Krammer
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lynda Coughlan
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
- Center for Vaccine Development and Global Health (CVD), University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
| | - Patrick C Wilson
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL, USA.
- Committee on Immunology, University of Chicago, Chicago, IL, USA.
- Drukier Institute for Children's Health, Department of Pediatrics, Weill Cornell Medicine, New York, NY, USA.
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56
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Michalski M, Setny P. Membrane-Bound Configuration and Lipid Perturbing Effects of Hemagglutinin Subunit 2 N-Terminus Investigated by Computer Simulations. Front Mol Biosci 2022; 9:826366. [PMID: 35155580 PMCID: PMC8830744 DOI: 10.3389/fmolb.2022.826366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/04/2022] [Indexed: 01/08/2023] Open
Abstract
Hemagglutinin (HA) mediated fusion of influenza virus envelope with host lipid membrane is a critical step warrantying virus entry to the cell. Despite tremendous advances in structural biology methods, the knowledge concerning the details of HA2 subunit insertion into the target membrane and its subsequent bilayer perturbing effect is still rather limited. Herein, based on a set of molecular dynamics simulations, we investigate the structure and interaction with lipid membrane of the N-terminal HA2 region comprising a trimer of fusion peptides (HAfps) tethered by flexible linkers to a fragment of coiled-coil stem structure. We find that, prior to insertion into the membrane, HAfps within the trimers do not sample space individually but rather associate into a compact hydrophobic aggregate. Once within the membrane, they fold into tight helical hairpins, which remain at the lipid-water interface. However, they can also assume stable, membrane-spanning configurations of significantly increased membrane-perturbing potential. In this latter case, HAfps trimers centre around the well-hydrated transmembrane channel-forming distinct, symmetric assemblies, whose wedge-like shape may play a role in promoting membrane curvature. We also demonstrate that, following HAfps insertion, the coiled-coil stem spontaneously tilts to almost membrane-parallel orientation, reflecting experimentally observed configuration adopted in the course of membrane fusion by complete HA2 units at the rim of membrane contact zones.
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57
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Zhang Y, Cui Y, Sun J, Zhou ZH. Multiple conformations of trimeric spikes visualized on a non-enveloped virus. Nat Commun 2022; 13:550. [PMID: 35087065 PMCID: PMC8795420 DOI: 10.1038/s41467-022-28114-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/10/2022] [Indexed: 11/18/2022] Open
Abstract
Many viruses utilize trimeric spikes to gain entry into host cells. However, without in situ structures of these trimeric spikes, a full understanding of this dynamic and essential process of viral infections is not possible. Here we present four in situ and one isolated cryoEM structures of the trimeric spike of the cytoplasmic polyhedrosis virus, a member of the non-enveloped Reoviridae family and a virus historically used as a model in the discoveries of RNA transcription and capping. These structures adopt two drastically different conformations, closed spike and opened spike, which respectively represent the penetration-inactive and penetration-active states. Each spike monomer has four domains: N-terminal, body, claw, and C-terminal. From closed to opened state, the RGD motif-containing C-terminal domain is freed to bind integrins, and the claw domain rotates to expose and project its membrane insertion loops into the cellular membrane. Comparison between turret vertices before and after detachment of the trimeric spike shows that the trimeric spike anchors its N-terminal domain in the iris of the pentameric RNA-capping turret. Sensing of cytosolic S-adenosylmethionine (SAM) and adenosine triphosphate (ATP) by the turret triggers a cascade of events: opening of the iris, detachment of the spike, and initiation of endogenous transcription. Zhang and Cui et al. present in situ cryoEM structures of the trimeric spike of cytoplasmic polyhedrosis virus in both open and close conformations, and demonstrate that spike detachment from the capsid is triggered by the presence of SAM and ATP.
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Affiliation(s)
- Yinong Zhang
- Subtropical Sericulture and Mulberry Resources Protection and Safety Engineering Research Center, Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China.,California Nanosystems Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA.,Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
| | - Yanxiang Cui
- California Nanosystems Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Jingchen Sun
- Subtropical Sericulture and Mulberry Resources Protection and Safety Engineering Research Center, Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China. .,Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA.
| | - Z Hong Zhou
- California Nanosystems Institute, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. .,Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA.
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58
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Naqvi AAT, Anjum F, Shafie A, Badar S, Elasbali AM, Yadav DK, Hassan MI. Investigating host-virus interaction mechanism and phylogenetic analysis of viral proteins involved in the pathogenesis. PLoS One 2021; 16:e0261497. [PMID: 34914801 PMCID: PMC8675761 DOI: 10.1371/journal.pone.0261497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/02/2021] [Indexed: 02/07/2023] Open
Abstract
Since the emergence of yellow fever in the Americas and the devastating 1918 influenza pandemic, biologists and clinicians have been drawn to human infecting viruses to understand their mechanisms of infection better and develop effective therapeutics against them. However, the complex molecular and cellular processes that these viruses use to infect and multiply in human cells have been a source of great concern for the scientific community since the discovery of the first human infecting virus. Viral disease outbreaks, such as the recent COVID-19 pandemic caused by a novel coronavirus, have claimed millions of lives and caused significant economic damage worldwide. In this study, we investigated the mechanisms of host-virus interaction and the molecular machinery involved in the pathogenesis of some common human viruses. We also performed a phylogenetic analysis of viral proteins involved in host-virus interaction to understand the changes in the sequence organization of these proteins during evolution for various strains of viruses to gain insights into the viral origin's evolutionary perspectives.
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Affiliation(s)
| | - Farah Anjum
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Alaa Shafie
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Sufian Badar
- Department of Computer Science, Jamia Millia Islamia, New Delhi, India
| | - Abdelbaset Mohamed Elasbali
- Clinical Laboratory Science, College of Applied Medical Sciences-Qurayyat, Jouf University, Sakakah, Saudi Arabia
| | - Dharmendra Kumar Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, Yeonsu-gu, Incheon City, South Korea
| | - Md. Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, India
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59
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Gamblin SJ, Vachieri SG, Xiong X, Zhang J, Martin SR, Skehel JJ. Hemagglutinin Structure and Activities. Cold Spring Harb Perspect Med 2021; 11:a038638. [PMID: 32513673 PMCID: PMC8485738 DOI: 10.1101/cshperspect.a038638] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hemagglutinins (HAs) are the receptor-binding and membrane fusion glycoproteins of influenza viruses. They recognize sialic acid-containing, cell-surface glycoconjugates as receptors but have limited affinity for them, and, as a consequence, virus attachment to cells requires their interaction with several virus HAs. Receptor-bound virus is transferred into endosomes where membrane fusion by HAs is activated at pH between 5 and 6.5, depending on the strain of virus. Fusion activity requires extensive rearrangements in HA conformation that include extrusion of a buried "fusion peptide" to connect with the endosomal membrane, form a bridge to the virus membrane, and eventually bring both membranes close together. In this review, we give an overview of the structures of the 16 genetically and antigenically distinct subtypes of influenza A HA in relation to these two functions in virus replication and in relation to recognition of HA by antibodies that neutralize infection.
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Affiliation(s)
- Steven J Gamblin
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Sébastien G Vachieri
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Xiaoli Xiong
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Jie Zhang
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Stephen R Martin
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - John J Skehel
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
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60
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Li S. Cryo-electron tomography of enveloped viruses. Trends Biochem Sci 2021; 47:173-186. [PMID: 34511334 DOI: 10.1016/j.tibs.2021.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/12/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
Viruses are macromolecular machineries that hijack cellular metabolism for replication. Enveloped viruses comprise a large variety of RNA and DNA viruses, many of which are notorious human or animal pathogens. Despite their importance, the presence of lipid bilayers in their assembly has made most enveloped viruses too pleomorphic to be reconstructed as a whole by traditional structural biology methods. Furthermore, structural biology of the viral lifecycle was hindered by the sample thickness. Here, I review the recent advances in the applications of cryo-electron tomography (cryo-ET) on enveloped viral structures and intracellular viral activities.
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Affiliation(s)
- Sai Li
- School of Life Sciences, Tsinghua University, Beijing 100084, China; Beijing Advanced Innovation Center for Structural Biology and Frontier Research Center for Biological Structure, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.
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61
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Harshbarger W, Abeyrathne PD, Tian S, Huang Y, Chandramouli S, Bottomley MJ, Malito E. Improved epitope resolution of the prefusion trimer-specific antibody AM14 bound to the RSV F glycoprotein. MAbs 2021; 13:1955812. [PMID: 34420474 PMCID: PMC8386734 DOI: 10.1080/19420862.2021.1955812] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory tract infections resulting in medical intervention and hospitalizations during infancy and early childhood, and vaccination against RSV remains a public health priority. The RSV F glycoprotein is a major target of neutralizing antibodies, and the prefusion stabilized form of F (DS-Cav1) is under investigation as a vaccine antigen. AM14 is a human monoclonal antibody with the exclusive capacity of binding an epitope on prefusion F (PreF), which spans two F protomers. The quality of recognizing a trimer-specific epitope makes AM14 valuable for probing PreF-based immunogen conformation and functionality during vaccine production. Currently, only a low-resolution (5.5 Å) X-ray structure is available of the PreF-AM14 complex, revealing few reliable details of the interface. Here, we perform complementary structural studies using X-ray crystallography and cryo-electron microscopy (cryo-EM) to provide improved resolution structures at 3.6 Å and 3.4 Å resolutions, respectively. Both X-ray and cryo-EM structures provide clear side-chain densities, which allow for accurate mapping of the AM14 epitope on DS-Cav1. The structures help rationalize the molecular basis for AM14 loss of binding to RSV F monoclonal antibody-resistant mutants and reveal flexibility for the side chain of a key antigenic residue on PreF. This work provides the basis for a comprehensive understanding of RSV F trimer specificity with implications in vaccine design and quality assessment of PreF-based immunogens.
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Affiliation(s)
| | | | - Sai Tian
- GSK, Vaccine Design and Cellular Immunology, Rockville, MD, USA
| | - Ying Huang
- GSK, Vaccine Design and Cellular Immunology, Rockville, MD, USA
| | | | | | - Enrico Malito
- GSK, Vaccine Design and Cellular Immunology, Rockville, MD, USA
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62
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Del Rosario JMM, da Costa KAS, Asbach B, Ferrara F, Ferrari M, Wells DA, Mann GS, Ameh VO, Sabeta CT, Banyard AC, Kinsley R, Scott SD, Wagner R, Heeney JL, Carnell GW, Temperton NJ. Exploiting Pan Influenza A and Pan Influenza B Pseudotype Libraries for Efficient Vaccine Antigen Selection. Vaccines (Basel) 2021; 9:741. [PMID: 34358157 PMCID: PMC8310092 DOI: 10.3390/vaccines9070741] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 06/09/2021] [Accepted: 06/21/2021] [Indexed: 12/15/2022] Open
Abstract
We developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18 and Influenza B subtypes (both lineages) to be employed in influenza pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for detecting virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza neutralization assays. We demonstrate their utility in detecting serum responses to vaccination with the ability to evaluate cross-subtype neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further preclinical studies involving immunization dosing regimens in mice and may help in the creation and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet strategic objectives that contribute to the strengthening of global influenza surveillance, expansion of seasonal influenza prevention and control policies, and strengthening pandemic preparedness and response.
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Affiliation(s)
- Joanne Marie M. Del Rosario
- Viral Pseudotype Unit, Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Chatham ME4 4BF, UK; (J.M.M.D.R.); (K.A.S.d.C.); (F.F.); (G.S.M.); (S.D.S.)
- Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, Manila 1000, Philippines
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
| | - Kelly A. S. da Costa
- Viral Pseudotype Unit, Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Chatham ME4 4BF, UK; (J.M.M.D.R.); (K.A.S.d.C.); (F.F.); (G.S.M.); (S.D.S.)
| | - Benedikt Asbach
- Institute of Medical Microbiology and Hygiene, University of Regensburg, 93053 Regensburg, Germany; (B.A.); (R.W.)
| | - Francesca Ferrara
- Viral Pseudotype Unit, Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Chatham ME4 4BF, UK; (J.M.M.D.R.); (K.A.S.d.C.); (F.F.); (G.S.M.); (S.D.S.)
- Vector Development and Production Laboratory, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Matteo Ferrari
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - David A. Wells
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - Gurdip Singh Mann
- Viral Pseudotype Unit, Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Chatham ME4 4BF, UK; (J.M.M.D.R.); (K.A.S.d.C.); (F.F.); (G.S.M.); (S.D.S.)
| | - Veronica O. Ameh
- Department of Veterinary Public Health and Preventive Medicine, College of Veterinary Medicine, Federal University of Agriculture Makurdi, Makurdi P.M.B. 2373, Bene State, Nigeria;
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, P. Bag X04, Onderstepoort 0110, South Africa;
| | - Claude T. Sabeta
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, P. Bag X04, Onderstepoort 0110, South Africa;
- OIE Rabies Reference Laboratory, Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa
| | - Ashley C. Banyard
- Animal and Plant Health Agency (APHA), Department of Virology, Weybridge, Surrey KT15 3NB, UK;
| | - Rebecca Kinsley
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - Simon D. Scott
- Viral Pseudotype Unit, Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Chatham ME4 4BF, UK; (J.M.M.D.R.); (K.A.S.d.C.); (F.F.); (G.S.M.); (S.D.S.)
| | - Ralf Wagner
- Institute of Medical Microbiology and Hygiene, University of Regensburg, 93053 Regensburg, Germany; (B.A.); (R.W.)
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Jonathan L. Heeney
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - George W. Carnell
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - Nigel J. Temperton
- Viral Pseudotype Unit, Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Chatham ME4 4BF, UK; (J.M.M.D.R.); (K.A.S.d.C.); (F.F.); (G.S.M.); (S.D.S.)
- DIOSynVax, Cambridge CB3 0ES, UK; (M.F.); (D.A.W.); (R.K.); (J.L.H.); (G.W.C.)
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63
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Kordyukova LV, Shanko AV. COVID-19: Myths and Reality. BIOCHEMISTRY. BIOKHIMIIA 2021; 86:800-817. [PMID: 34284707 PMCID: PMC8265000 DOI: 10.1134/s0006297921070026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023]
Abstract
COVID-19, a new human respiratory disease that has killed nearly 3 million people in a year since the start of the pandemic, is a global public health challenge. Its infectious agent, SARS-CoV-2, differs from other coronaviruses in a number of structural features that make this virus more pathogenic and transmissible. In this review, we discuss some important characteristics of the main SARS-CoV-2 surface antigen, the spike (S) protein, such as (i) ability of the receptor-binding domain (RBD) to switch between the "standing-up" position (open pre-fusion conformation) for receptor binding and the "lying-down" position (closed pre-fusion conformation) for immune system evasion; (ii) advantage of a high binding affinity of the RBD open conformation to the human angiotensin-converting enzyme 2 (ACE2) receptor for efficient cell entry; and (iii) S protein preliminary activation by the intracellular furin-like proteases for facilitation of the virus spreading across different cell types. We describe interactions between the S protein and cellular receptors, co-receptors, and antagonists, as well as a hypothetical mechanism of the homotrimeric spike structure destabilization that triggers the fusion of the viral envelope with the cell membrane at physiological pH and mediates the viral nucleocapsid entry into the cytoplasm. The transition of the S protein pre-fusion conformation to the post-fusion one on the surface of virions after their treatment with some reagents, such as β-propiolactone, is essential, especially in relation to the vaccine production. We also compare the COVID-19 pathogenesis with that of severe outbreaks of "avian" influenza caused by the A/H5 and A/H7 highly pathogenic viruses and discuss the structural similarities between the SARS-CoV-2 S protein and hemagglutinins of those highly pathogenic strains. Finally, we touch on the prospective and currently used COVID-19 antiviral and anti-pathogenetic therapeutics, as well as recently approved conventional and innovative COVID-19 vaccines and their molecular and immunological features.
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Affiliation(s)
- Larisa V Kordyukova
- Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| | - Andrey V Shanko
- FORT LLC, R&D Department, Moscow, 119435, Russia
- Ivanovsky Institute of Virology, Gamaleya Federal Research Center for Epidemiology and Microbiology, Moscow, 123098, Russia
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64
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Guthmiller JJ, Utset HA, Wilson PC. B Cell Responses against Influenza Viruses: Short-Lived Humoral Immunity against a Life-Long Threat. Viruses 2021; 13:965. [PMID: 34067435 PMCID: PMC8224597 DOI: 10.3390/v13060965] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 12/25/2022] Open
Abstract
Antibodies are critical for providing protection against influenza virus infections. However, protective humoral immunity against influenza viruses is limited by the antigenic drift and shift of the major surface glycoproteins, hemagglutinin and neuraminidase. Importantly, people are exposed to influenza viruses throughout their life and tend to reuse memory B cells from prior exposure to generate antibodies against new variants. Despite this, people tend to recall memory B cells against constantly evolving variable epitopes or non-protective antigens, as opposed to recalling them against broadly neutralizing epitopes of hemagglutinin. In this review, we discuss the factors that impact the generation and recall of memory B cells against distinct viral antigens, as well as the immunological limitations preventing broadly neutralizing antibody responses. Lastly, we discuss how next-generation vaccine platforms can potentially overcome these obstacles to generate robust and long-lived protection against influenza A viruses.
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Affiliation(s)
- Jenna J. Guthmiller
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (H.A.U.); (P.C.W.)
| | - Henry A. Utset
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (H.A.U.); (P.C.W.)
| | - Patrick C. Wilson
- Section of Rheumatology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (H.A.U.); (P.C.W.)
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA
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65
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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] [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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66
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Brito JCM, Lima WG, Cordeiro LPB, da Cruz Nizer WS. Effectiveness of supplementation with quercetin-type flavonols for treatment of viral lower respiratory tract infections: Systematic review and meta-analysis of preclinical studies. Phytother Res 2021; 35:4930-4942. [PMID: 33864310 PMCID: PMC8250479 DOI: 10.1002/ptr.7122] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 02/15/2021] [Accepted: 03/26/2021] [Indexed: 12/17/2022]
Abstract
Viral infections of the lower respiratory tract are considered a public health problem. They affect millions of people worldwide, causing thousands of deaths, and are treated with expensive medicines, such as antivirals or palliative measures. In this study, we conducted a systematic review to describe the use of quercetin‐type flavonols against lower respiratory tract viruses and discussed the preclinical impact of this approach on different signs and clinical mechanisms of infection. The systematic review was performed in PubMed/MEDLINE, Scopus, Scielo, and Biblioteca Virtual de Saúde (BVS). After the database search, 11 relevant studies were identified as eligible. The analysis of these studies showed evidence of antiviral activity of quercetin‐type flavonols with significantly reduced mortality rate (M‐H = 0.19, 95% CI: 0.05 to 0.65, p‐value = 0.008) of infected animals and a reduction in the average viral load (IV = −1.93, 95% CI: −3.54 to −0.31, p‐value = 0.02). Additionally, quercetin and its derivatives reduced the amount of proinflammatory cytokines, chemokines, reactive oxygen species, mucus production, and airway resistance in animals infected with a respiratory virus. Overall, supplementation with quercetin‐type flavonols is a promising strategy for treating viral‐induced lower respiratory tract infections.
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Affiliation(s)
- Júlio César Moreira Brito
- Department of Research and Development, Ezequiel Dias Foundation (FUNED), Belo Horizonte, MG, Brazil.,Researcher of the Group (CNPq), Epidemiological, Economic and Pharmacological Studies of Arboviruses (EEPIFARBO), Belo Horizonte, MG, Brazil
| | - William Gustavo Lima
- Researcher of the Group (CNPq), Epidemiological, Economic and Pharmacological Studies of Arboviruses (EEPIFARBO), Belo Horizonte, MG, Brazil
| | - Lídia Pereira B Cordeiro
- Chemistry Department, Institute of Exact Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
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67
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Amphipathic environments for determining the structure of membrane proteins by single-particle electron cryo-microscopy. Q Rev Biophys 2021; 54:e6. [PMID: 33785082 DOI: 10.1017/s0033583521000044] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the past decade, the structural biology of membrane proteins (MPs) has taken a new turn thanks to epoch-making technical progress in single-particle electron cryo-microscopy (cryo-EM) as well as to improvements in sample preparation. The present analysis provides an overview of the extent and modes of usage of the various types of surfactants for cryo-EM studies. Digitonin, dodecylmaltoside, protein-based nanodiscs, lauryl maltoside-neopentyl glycol, glyco-diosgenin, and amphipols (APols) are the most popular surfactants at the vitrification step. Surfactant exchange is frequently used between MP purification and grid preparation, requiring extensive optimization each time the study of a new MP is undertaken. The variety of both the surfactants and experimental approaches used over the past few years bears witness to the need to continue developing innovative surfactants and optimizing conditions for sample preparation. The possibilities offered by novel APols for EM applications are discussed.
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68
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Halldorsson S, Sader K, Turner J, Calder LJ, Rosenthal PB. In situ structure and organization of the influenza C virus surface glycoprotein. Nat Commun 2021; 12:1694. [PMID: 33727554 PMCID: PMC7966785 DOI: 10.1038/s41467-021-21818-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 02/11/2021] [Indexed: 11/09/2022] Open
Abstract
The lipid-enveloped influenza C virus contains a single surface glycoprotein, the haemagglutinin-esterase-fusion (HEF) protein, that mediates receptor binding, receptor destruction, and membrane fusion at the low pH of the endosome. Here we apply electron cryotomography and subtomogram averaging to describe the structural basis for hexagonal lattice formation by HEF on the viral surface. The conformation of the glycoprotein in situ is distinct from the structure of the isolated trimeric ectodomain, showing that a splaying of the membrane distal domains is required to mediate contacts that form the lattice. The splaying of these domains is also coupled to changes in the structure of the stem region which is involved in membrane fusion, thereby linking HEF's membrane fusion conformation with its assembly on the virus surface. The glycoprotein lattice can form independent of other virion components but we show a major role for the matrix layer in particle formation.
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Affiliation(s)
- Steinar Halldorsson
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Kasim Sader
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, The Netherlands
| | - Jack Turner
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lesley J Calder
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom.
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69
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Borisevich SS, Gureev MA, Yarovaya ОI, Zarubaev VV, Kostin GA, Porozov YB, Salakhutdinov NF. Can molecular dynamics explain decreased pathogenicity in mutant camphecene-resistant influenza virus? J Biomol Struct Dyn 2021; 40:5481-5492. [PMID: 33480324 DOI: 10.1080/07391102.2020.1871414] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
ABSTARCTThe development of new anti-influenza drugs remains an active area, and efforts in this direction will likely continue far into the future. In this paper, we present the results of a theoretical study explaining the mechanisms behind the antiviral activity of camphor derivatives. These include camphecene and a number of its analogues. The compounds tested can inhibit hemagglutinin (HA) by binding to it at two possible sites. Moreover, the binding site located at the site of proteolysis is the most important. Serial passaging of influenza in the presence of camphecene leads to the formation of mutation-associated resistance. Specifically, camphecene causes a significant mutation in HA (V615L). This substitution likely reduces the affinity of the compound for the binding site due to steric restriction of the positioning of camphecene in the binding cavity. Molecular dynamics (MD) simulation results show that the mutant HA is a more stable structure in terms of thermodynamics. In other words, launching conformational rearrangements preceding the transition from pre- to post-fusion requires more energy than in wild type HA. This may well explain the lower virulence seen with the camphecene-resistant strain.
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Affiliation(s)
- Sophia S Borisevich
- Laboratory of Physical Chemistry, Ufa Institute of Chemistry UFRS RAS, Ufa, Russia
| | - Maxim A Gureev
- Laboratory of Bioinformatics, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Оlga I Yarovaya
- Department of Medicinal Chemistry, N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch RAS, Novosibirsk, Russia
| | - Vladimir V Zarubaev
- Department of Virology, Saint Petersburg Pasteur Institute, St. Petersburg, Russia
| | - Gennadiy A Kostin
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russia
| | - Yuriy B Porozov
- Laboratory of Bioinformatics, I.M. Sechenov First Moscow State Medical University, Moscow, Russia.,Department of Food Biotechnology and Engineering, ITMO University, St. Petersburg, Russia.,Department of Computational Biology, Sirius University of Science and Technology, Sochi, Russia
| | - Nariman F Salakhutdinov
- Department of Medicinal Chemistry, N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch RAS, Novosibirsk, Russia
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70
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Chiliveri SC, Louis JM, Bax A. Concentration‐Dependent Structural Transition of the HIV‐1 gp41 MPER Peptide into α‐Helical Trimers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202008804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sai Chaitanya Chiliveri
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases Bethesda MD 20892 USA
| | - John M. Louis
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases Bethesda MD 20892 USA
| | - Ad Bax
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases Bethesda MD 20892 USA
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71
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Do PC, Nguyen TH, Vo UHM, Le L. iBRAB: In silico based-designed broad-spectrum Fab against H1N1 influenza A virus. PLoS One 2020; 15:e0239112. [PMID: 33382708 PMCID: PMC7774956 DOI: 10.1371/journal.pone.0239112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 12/15/2020] [Indexed: 11/19/2022] Open
Abstract
Influenza virus A is a significant agent involved in the outbreak of worldwide epidemics, causing millions of fatalities around the world by respiratory diseases and seasonal illness. Many projects had been conducting to investigate recovered infected patients for therapeutic vaccines that have broad-spectrum activity. With the aid of the computational approach in biology, the designation for a vaccine model is more accessible. We developed an in silico protocol called iBRAB to design a broad-reactive Fab on a wide range of influenza A virus. The Fab model was constructed based on sequences and structures of available broad-spectrum Abs or Fabs against a wide range of H1N1 influenza A virus. As a result, the proposed Fab model followed iBRAB has good binding affinity over 27 selected HA of different strains of H1 influenza A virus, including wild-type and mutated ones. The examination also took by computational tools to fasten the procedure. This protocol could be applied for a fast-designed therapeutic vaccine against different types of threats.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Viral/chemistry
- Antibodies, Viral/genetics
- Antigens, Viral/chemistry
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Binding Sites
- Computer Simulation
- Drug Design
- Hemagglutinin Glycoproteins, Influenza Virus/chemistry
- Hemagglutinin Glycoproteins, Influenza Virus/genetics
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Humans
- Immunoglobulin Fab Fragments/chemistry
- Immunoglobulin Fab Fragments/genetics
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/biosynthesis
- Influenza, Human/immunology
- Influenza, Human/prevention & control
- Influenza, Human/virology
- Molecular Docking Simulation
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Sequence Alignment
- Sequence Homology, Amino Acid
- Thermodynamics
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Affiliation(s)
- Phuc-Chau Do
- School of Biotechnology, International University, Thu Duc District, Hochiminh City, Vietnam
- Vietnam National University Ho Chi Minh City, Thu Duc District, Hochiminh City, Vietnam
| | - Trung H. Nguyen
- School of Biotechnology, International University, Thu Duc District, Hochiminh City, Vietnam
- Vietnam National University Ho Chi Minh City, Thu Duc District, Hochiminh City, Vietnam
| | - Uyen H. M. Vo
- School of Biotechnology, International University, Thu Duc District, Hochiminh City, Vietnam
- Vietnam National University Ho Chi Minh City, Thu Duc District, Hochiminh City, Vietnam
| | - Ly Le
- School of Biotechnology, International University, Thu Duc District, Hochiminh City, Vietnam
- Vietnam National University Ho Chi Minh City, Thu Duc District, Hochiminh City, Vietnam
- Vingroup Big Data Institute, Hai Ba Trung District, Ha Noi, Vietnam
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72
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Influenza A H1 and H3 Transmembrane Domains Interact Differently with Each Other and with Surrounding Membrane Lipids. Viruses 2020; 12:v12121461. [PMID: 33348831 PMCID: PMC7765950 DOI: 10.3390/v12121461] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
Hemagglutinin (HA) is a class I viral membrane fusion protein, which is the most abundant transmembrane protein on the surface of influenza A virus (IAV) particles. HA plays a crucial role in the recognition of the host cell, fusion of the viral envelope and the host cell membrane, and is the major antigen in the immune response during the infection. Mature HA organizes in homotrimers consisting of a sequentially highly variable globular head and a relatively conserved stalk region. Every HA monomer comprises a hydrophilic ectodomain, a pre-transmembrane domain (pre-TMD), a hydrophobic transmembrane domain (TMD), and a cytoplasmic tail (CT). In recent years the effect of the pre-TMD and TMD on the structure and function of HA has drawn some attention. Using bioinformatic tools we analyzed all available full-length amino acid sequences of HA from 16 subtypes across various host species. We calculated several physico-chemical parameters of HA pre-TMDs and TMDs including accessible surface area (ASA), average hydrophobicity (Hav), and the hydrophobic moment (µH). Our data suggests that distinct differences in these parameters between the two major phylogenetic groups, represented by H1 and H3 subtypes, could have profound effects on protein–lipid interactions, trimer formation, and the overall HA ectodomain orientation and antigen exposure.
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73
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Khrustalev VV, Kordyukova LV, Arutyunyan AM, Poboinev VV, Khrustaleva TA, Stojarov AN, Baratova LA, Sapon AS, Lugin VG. The cytoplasmic tail of influenza A/H1N1 virus hemagglutinin is β-structural. J Biomol Struct Dyn 2020; 40:4642-4661. [PMID: 33317396 DOI: 10.1080/07391102.2020.1860827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Influenza A/H1N1 virus hemagglutinin (HA) is an integral type I glycoprotein that contains a large glycosylated ectodomain, a transmembrane domain, and a cytoplasmic tail (CT) of 10-14 amino acid residues. There are absolutely no data on the secondary or tertiary structure of the HA CT, which is important for virus pathogenesis. Three highly conserved cysteines are post-translationally modified by the attachment of fatty acid residues that pin the CT to the lipid membrane inside the virion. We applied circular dichroism (CD) and fluorescence spectroscopy analysis to examine four synthetic peptides corresponding to 14-15 C-terminal residues of H1 subtype HA (NH2-WMCSNGSLQCRICI-COOH; NH2-FWMCSNGSLQCRICI-COOH), with free or acetaminomethylated cysteines, in the reduced or non-reduced state, at various pH values and temperatures. The CD analysis detected the formation of a β-structure (30-65% according to the new BeStSel algorithm), in addition to an unstructured random coil, in every peptide in various conditions. It was completely or partially recognized as an antiparallel β-structure that was also confirmed by the multi-bounce Horizontal Attenuated Total Reflectance Fourier Transformed Infrared (HATR-FTIR) spectroscopy analysis. According to the experimental data, as well as 3 D modeling, we assume that the amino acid sequence corresponding to the HA CT may form a short antiparallel β-structure under the lipid membrane within a virion.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Larisa V Kordyukova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Alexander M Arutyunyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Victor V Poboinev
- Department of General Chemistry, Belarusian State Medical University, Minsk, Belarus
| | - Tatyana A Khrustaleva
- Biochemical group of the Multidisciplinary Diagnostic Laboratory, Institute of Physiology of the National Academy of Sciences of Belarus, Minsk, Belarus
| | - Aleksander N Stojarov
- Department of Radiation Medicine and Ecology, Belarusian State Medical University, Minsk, Belarus
| | - Lyudmila A Baratova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Alena S Sapon
- Center for Physical and Chemical Research Methods, Belarusian State Technological University, Minsk, Belarus
| | - Valery G Lugin
- Center for Physical and Chemical Research Methods, Belarusian State Technological University, Minsk, Belarus
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74
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Jafari D, Malih S, Gomari MM, Safari M, Jafari R, Farajollahi MM. Designing a chimeric subunit vaccine for influenza virus, based on HA2, M2e and CTxB: a bioinformatics study. BMC Mol Cell Biol 2020; 21:89. [PMID: 33276715 PMCID: PMC7716444 DOI: 10.1186/s12860-020-00334-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 11/25/2020] [Indexed: 11/10/2022] Open
Abstract
Background Type A influenza viruses are contagious and even life-threatening if left untreated. So far, no broadly protective vaccine is available due to rapid antigenic changes and emergence of new subtypes of influenza virus. In this study, we exploited bioinformatics tools in order to design a subunit chimeric vaccine from the antigenic and highly conserved regions of HA and M2 proteins of H7N9 subtype of influenza virus. We used mucosal adjuvant candidates, including CTxB, STxB, ASP-1, and LTB to stimulate mucosal immunity and analyzed the combination of HA2, M2e, and the adjuvant. Furthermore, to improve the antigen function and to maintain their three-dimensional structure, 12 different linkers including six rigid linkers and six flexible linkers were used. The 3D structure model was generated using a combination of homology and ab initio modeling methods and the molecular dynamics of the model were analyzed, either. Results Analysis of different adjuvants showed that using CtxB as an adjuvant, results in higher overall vaccine stability and higher half-life among four adjuvant candidates. Fusion of antigens and the CTxB in the form of M2e-linker-CTxB-linker-HA2 has the most stability and half life compared to other combination forms. Furthermore, the KPKPKP rigid linker showed the best result for this candidate vaccine among 12 analyzed linkers. The changes in the vaccine 3D structure made by linker insertion found to be negligible, however, although small, the linker insertion between the antigens causes the structure to change slightly. Eventually, using predictive tools such as Ellipro, NetMHCpan I and II, CD4episcore, CTLpred, BepiPred and other epitope analyzing tools, we analyzed the conformational and linear epitopes of the vaccine. The solubility, proteasome cleavage sites, peptidase and potential chemical cutters, codon optimization, post translational modification were also carried out on the final vaccine. Conclusions It is concluded that M2e-Linker-CTxB-Linker-HA2 combination of chimeric vaccine retains its 3D structure and antigenicity when KPKPKP used as linker and CTxB used as adjuvant. Supplementary Information The online version contains supplementary material available at 10.1186/s12860-020-00334-6.
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Affiliation(s)
- Davod Jafari
- Student Research Committee, Faculty of Allied Medicine, Iran University of Medical Sciences, Hemmat Highway, Tehran, Iran. .,Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Sara Malih
- Department of Medical Biotechnology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Mahmoudi Gomari
- Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Marzieh Safari
- Department of Microbiology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Rasool Jafari
- Department of Medical Parasitology and Mycology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Mohammad Morad Farajollahi
- Student Research Committee, Faculty of Allied Medicine, Iran University of Medical Sciences, Hemmat Highway, Tehran, Iran.
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75
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Chiliveri SC, Louis JM, Bax A. Concentration-Dependent Structural Transition of the HIV-1 gp41 MPER Peptide into α-Helical Trimers. Angew Chem Int Ed Engl 2020; 60:166-170. [PMID: 32916024 DOI: 10.1002/anie.202008804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/20/2020] [Indexed: 11/12/2022]
Abstract
The membrane proximal external region (MPER) of HIV-1 gp41 contains epitopes for at least four broadly neutralizing antibodies. Depending on solution conditions and construct design, different structures have been reported for this segment. We show that in aqueous solution the MPER fragment (gp160660-674 ) exists in a monomer-trimer equilibrium with an association constant in the micromolar range. Thermodynamic analysis reveals that the association is exothermic, more favorable in D2 O than H2 O, and increases with ionic strength, indicating hydrophobically driven intermolecular interactions. Circular dichroism, 13 Cα chemical shifts, NOE, and hydrogen exchange rates reveal that MPER undergoes a structural transition from predominately unfolded monomer at low concentrations to an α-helical trimer at high concentrations. This result has implications for antibody recognition of MPER prior to and during the process where gp41 switches from a pre-hairpin intermediate to its post-fusion 6-helical bundle state.
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Affiliation(s)
- Sai Chaitanya Chiliveri
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - John M Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
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76
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Sitaras I, Spackman E, de Jong MCM, Parris DJ. Selection and antigenic characterization of immune-escape mutants of H7N2 low pathogenic avian influenza virus using homologous polyclonal sera. Virus Res 2020; 290:198188. [PMID: 33045306 DOI: 10.1016/j.virusres.2020.198188] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 09/18/2020] [Accepted: 10/05/2020] [Indexed: 01/24/2023]
Abstract
Understanding the dynamics of the selection of influenza A immune escape variants by serum antibody is critical for designing effective vaccination programs for animals, especially poultry where large populations have a short generation time and may be vaccinated with high frequency. In this report, immune-escape mutants of A/turkey/New York/4450/1994 H7N2 low pathogenic avian influenza virus, were selected by serially passaging the virus in the presence of continuously increasing concentrations of homologous chicken polyclonal sera. Amino acid mutations were identified by sequencing the parental hemagglutinin (HA) gene and every 10 passages by both Sanger and deep sequencing, and the antigenic distance of the mutants to the parent strain was determined. Progressively, a total of five amino acid mutations were observed over the course of 30 passages. Based on their absence from the parental virus with deep sequencing, the mutations appear to have developed de novo. The antigenic distance between the selected mutants and the parent strain increased as the number of amino acid mutations accumulated and the concentration of antibodies had to be periodically increased to maintain the same reduction in virus titer during selection. This selection system demonstrates how H7 avian influenza viruses behave under selection with homologous sera, and provides a glimpse of their evolutionary dynamics, which can be applied to developing vaccination programs that maximize the effectiveness of a vaccine over time.
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Affiliation(s)
- Ioannis Sitaras
- Exotic and Emerging Avian Viral Diseases Unit, Southeast Poultry Research Laboratory, United States National Poultry Research Center, United States Department of Agriculture, Agricultural Research Service, 934 College Station Road, Athens, GA, 30605, USA
| | - Erica Spackman
- Exotic and Emerging Avian Viral Diseases Unit, Southeast Poultry Research Laboratory, United States National Poultry Research Center, United States Department of Agriculture, Agricultural Research Service, 934 College Station Road, Athens, GA, 30605, USA.
| | - Mart C M de Jong
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, The Netherlands
| | - D Joshua Parris
- Exotic and Emerging Avian Viral Diseases Unit, Southeast Poultry Research Laboratory, United States National Poultry Research Center, United States Department of Agriculture, Agricultural Research Service, 934 College Station Road, Athens, GA, 30605, USA
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77
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Turoňová B, Sikora M, Schürmann C, Hagen WJH, Welsch S, Blanc FEC, von Bülow S, Gecht M, Bagola K, Hörner C, van Zandbergen G, Landry J, de Azevedo NTD, Mosalaganti S, Schwarz A, Covino R, Mühlebach MD, Hummer G, Krijnse Locker J, Beck M. In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges. Science 2020; 370:203-208. [PMID: 32817270 DOI: 10.1101/2020.06.26.173476] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/13/2020] [Indexed: 05/24/2023]
Abstract
The spike protein (S) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required for cell entry and is the primary focus for vaccine development. In this study, we combined cryo-electron tomography, subtomogram averaging, and molecular dynamics simulations to structurally analyze S in situ. Compared with the recombinant S, the viral S was more heavily glycosylated and occurred mostly in the closed prefusion conformation. We show that the stalk domain of S contains three hinges, giving the head unexpected orientational freedom. We propose that the hinges allow S to scan the host cell surface, shielded from antibodies by an extensive glycan coat. The structure of native S contributes to our understanding of SARS-CoV-2 infection and potentially to the development of safe vaccines.
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Affiliation(s)
- Beata Turoňová
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Mateusz Sikora
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Christoph Schürmann
- Division of Veterinary Medicine, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
| | - Wim J H Hagen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Florian E C Blanc
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Sören von Bülow
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Michael Gecht
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Katrin Bagola
- Division of Immunology, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
| | - Cindy Hörner
- Division of Veterinary Medicine, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
- German Center for Infection Research, Gießen-Marburg-Langen, Germany
| | - Ger van Zandbergen
- Division of Immunology, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
- Institute for Immunology, University Medical Center, Johannes Gutenberg University Mainz, Mainz, Germany
- Research Center for Immunotherapy (FZI), University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Jonathan Landry
- Genomics Core Facility, EMBL, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | | | - Shyamal Mosalaganti
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Andre Schwarz
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Roberto Covino
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main, Germany
| | - Michael D Mühlebach
- Division of Veterinary Medicine, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
- German Center for Infection Research, Gießen-Marburg-Langen, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany.
- Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Jacomine Krijnse Locker
- Electron Microscopy of Pathogens Unit, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany.
| | - Martin Beck
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
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78
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Stilhano RS, Costa AJ, Nishino MS, Shams S, Bartolomeo CS, Breithaupt-Faloppa AC, Silva EA, Ramirez AL, Prado CM, Ureshino RP. SARS-CoV-2 and the possible connection to ERs, ACE2, and RAGE: Focus on susceptibility factors. FASEB J 2020; 34:14103-14119. [PMID: 32965736 PMCID: PMC7537138 DOI: 10.1096/fj.202001394rr] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/15/2020] [Accepted: 08/25/2020] [Indexed: 12/11/2022]
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has provoked major stresses on the health-care systems of several countries, and caused the death of more than a quarter of a million people globally, mainly in the elderly population with preexisting pathologies. Previous studies with coronavirus (SARS-CoV) point to gender differences in infection and disease progression with increased susceptibility in male patients, indicating that estrogens may be associated with physiological protection against the coronavirus. Therefore, the objectives of this work are threefold. First, we aim to summarize the SARS-CoV-2 infection pathway and the roles both the virus and patient play in COVID-19 (Coronavirus disease 2019) progression, clinical symptomatology, and mortality. Second, we detail the effect estrogen has on viral infection and host infection response, including its role in both the regulation of key viral receptor expression and the mediation of inflammatory activity. Finally, we describe how ERs (estrogen receptors) and RAGE (receptor for advanced glycation end-products) play a critical role in metabolic pathways, which we envisage could maintain a close interplay with SARS-CoV and COVID-19 mortality rates, despite a current lack of research directly determining how. Taken together, we present the current state of the field regarding SARS-CoV-2 research and illuminate where research is needed to better define the role both estrogen and metabolic comorbidities have in the COVID-19 disease state, which can be key in screening potential therapeutic options as the search for effective treatments continue.
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Affiliation(s)
- Roberta Sessa Stilhano
- Department of Physiological Sciences, Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, Brazil
| | - Angelica Jardim Costa
- Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Michelle Sayuri Nishino
- Department of Biological Sciences, Universidade Federal de São Paulo, Diadema, Brazil.,Laboratory of Molecular and Translational Endocrinology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Shahin Shams
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Cynthia Silva Bartolomeo
- Department of Physiological Sciences, Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, Brazil.,Department of Biosciences, Universidade Federal de São Paulo, Santos, Brazil
| | - Ana Cristina Breithaupt-Faloppa
- Laboratorio de Cirurgia Cardiovascular e Fisiopatologia da Circulação (LIM-11), Instituto do Coração (InCor), Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | | | | | - Carla Maximo Prado
- Department of Biosciences, Universidade Federal de São Paulo, Santos, Brazil
| | - Rodrigo Portes Ureshino
- Department of Biological Sciences, Universidade Federal de São Paulo, Diadema, Brazil.,Laboratory of Molecular and Translational Endocrinology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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79
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Structural Biology of Influenza Hemagglutinin: An Amaranthine Adventure. Viruses 2020; 12:v12091053. [PMID: 32971825 PMCID: PMC7551194 DOI: 10.3390/v12091053] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/27/2022] Open
Abstract
Hemagglutinin (HA) glycoprotein is an important focus of influenza research due to its role in antigenic drift and shift, as well as its receptor binding and membrane fusion functions, which are indispensable for viral entry. Over the past four decades, X-ray crystallography has greatly facilitated our understanding of HA receptor binding, membrane fusion, and antigenicity. The recent advances in cryo-EM have further deepened our comprehension of HA biology. Since influenza HA constantly evolves in natural circulating strains, there are always new questions to be answered. The incessant accumulation of knowledge on the structural biology of HA over several decades has also facilitated the design and development of novel therapeutics and vaccines. This review describes the current status of the field of HA structural biology, how we got here, and what the next steps might be.
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80
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Turoňová B, Sikora M, Schürmann C, Hagen WJH, Welsch S, Blanc FEC, von Bülow S, Gecht M, Bagola K, Hörner C, van Zandbergen G, Landry J, de Azevedo NTD, Mosalaganti S, Schwarz A, Covino R, Mühlebach MD, Hummer G, Krijnse Locker J, Beck M. In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges. Science 2020; 370:203-208. [PMID: 32817270 PMCID: PMC7665311 DOI: 10.1126/science.abd5223] [Citation(s) in RCA: 442] [Impact Index Per Article: 110.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
The spike protein (S) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required for cell entry and is the primary focus for vaccine development. In this study, we combined cryo-electron tomography, subtomogram averaging, and molecular dynamics simulations to structurally analyze S in situ. Compared with the recombinant S, the viral S was more heavily glycosylated and occurred mostly in the closed prefusion conformation. We show that the stalk domain of S contains three hinges, giving the head unexpected orientational freedom. We propose that the hinges allow S to scan the host cell surface, shielded from antibodies by an extensive glycan coat. The structure of native S contributes to our understanding of SARS-CoV-2 infection and potentially to the development of safe vaccines.
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Affiliation(s)
- Beata Turoňová
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.,Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Mateusz Sikora
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Christoph Schürmann
- Division of Veterinary Medicine, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
| | - Wim J H Hagen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Florian E C Blanc
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Sören von Bülow
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Michael Gecht
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Katrin Bagola
- Division of Immunology, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany
| | - Cindy Hörner
- Division of Veterinary Medicine, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany.,German Center for Infection Research, Gießen-Marburg-Langen, Germany
| | - Ger van Zandbergen
- Division of Immunology, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany.,Institute for Immunology, University Medical Center, Johannes Gutenberg University Mainz, Mainz, Germany.,Research Center for Immunotherapy (FZI), University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Jonathan Landry
- Genomics Core Facility, EMBL, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | | | - Shyamal Mosalaganti
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany.,Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
| | - Andre Schwarz
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Roberto Covino
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany.,Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main, Germany
| | - Michael D Mühlebach
- Division of Veterinary Medicine, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany.,German Center for Infection Research, Gießen-Marburg-Langen, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany. .,Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Jacomine Krijnse Locker
- Electron Microscopy of Pathogens Unit, Paul Ehrlich Institute, Paul Ehrlich Strasse 51-59, 63225 Langen, Germany.
| | - Martin Beck
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany. .,Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main, Germany
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81
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Wu NC, Wilson IA. Influenza Hemagglutinin Structures and Antibody Recognition. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a038778. [PMID: 31871236 DOI: 10.1101/cshperspect.a038778] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hemagglutinin (HA) is most abundant glycoprotein on the influenza virus surface. Influenza HA promotes viral entry by engaging the receptor and mediating virus-host membrane fusion. At the same time, HA is the major antigen of the influenza virus. HA antigenic shift can result in pandemics, whereas antigenic drift allows human circulating strains to escape herd immunity. Most antibody responses against HA are strain-specific. However, antibodies that have neutralizing activities against multiple strains or even subtypes have now been discovered and characterized. These broadly neutralizing antibodies (bnAbs) target conserved regions on HA, such as the receptor-binding site and the stem domain. Structural studies of such bnAbs have provided important insight into universal influenza vaccine and therapeutic design. This review discusses the HA functions as well as HA-antibody interactions from a structural perspective.
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Affiliation(s)
- Nicholas C Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, USA.,The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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82
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Sharon DM, Nesdoly S, Yang HJ, Gélinas JF, Xia Y, Ansorge S, Kamen AA. A pooled genome-wide screening strategy to identify and rank influenza host restriction factors in cell-based vaccine production platforms. Sci Rep 2020; 10:12166. [PMID: 32699298 PMCID: PMC7376217 DOI: 10.1038/s41598-020-68934-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/30/2020] [Indexed: 12/26/2022] Open
Abstract
Cell-derived influenza vaccines provide better protection and a host of other advantages compared to the egg-derived vaccines that currently dominate the market, but their widespread use is hampered by a lack of high yield, low cost production platforms. Identification and knockout of innate immune and metabolic restriction factors within relevant host cell lines used to grow the virus could offer a means to substantially increase vaccine yield. In this paper, we describe and validate a novel genome-wide pooled CRISPR/Cas9 screening strategy that incorporates a reporter virus and a FACS selection step to identify and rank restriction factors in a given vaccine production cell line. Using the HEK-293SF cell line and A/PuertoRico/8/1934 H1N1 influenza as a model, we identify 64 putative influenza restriction factors to direct the creation of high yield knockout cell lines. In addition, gene ontology and protein complex enrichment analysis of this list of putative restriction factors offers broader insights into the primary host cell determinants of viral yield in cell-based vaccine production systems. Overall, this work will advance efforts to address the public health burden posed by influenza.
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MESH Headings
- CRISPR-Cas Systems/genetics
- Cell Survival
- Gene Editing
- Gene Ontology
- Genes, Reporter
- Genetic Vectors/genetics
- Genetic Vectors/metabolism
- Genome, Viral
- HEK293 Cells
- Humans
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/isolation & purification
- Influenza A Virus, H1N1 Subtype/physiology
- Influenza Vaccines/genetics
- Influenza Vaccines/immunology
- Influenza Vaccines/metabolism
- Influenza, Human/pathology
- Influenza, Human/prevention & control
- Influenza, Human/virology
- RNA, Guide, CRISPR-Cas Systems/metabolism
- Virus Replication
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Affiliation(s)
- David M. Sharon
- Department of Bioengineering, McGill University, McConnell Engineering Building, Room 363, 3480 Rue University, Montreal, QC H3A 2K6 Canada
| | - Sean Nesdoly
- Department of Bioengineering, McGill University, McConnell Engineering Building, Room 363, 3480 Rue University, Montreal, QC H3A 2K6 Canada
| | - Hsin J. Yang
- Department of Bioengineering, McGill University, McConnell Engineering Building, Room 363, 3480 Rue University, Montreal, QC H3A 2K6 Canada
| | - Jean-François Gélinas
- Department of Bioengineering, McGill University, McConnell Engineering Building, Room 363, 3480 Rue University, Montreal, QC H3A 2K6 Canada
| | - Yu Xia
- Department of Bioengineering, McGill University, McConnell Engineering Building, Room 363, 3480 Rue University, Montreal, QC H3A 2K6 Canada
| | - Sven Ansorge
- Human Health Therapeutics, National Research Council of Canada, Montreal, QC Canada
| | - Amine A. Kamen
- Department of Bioengineering, McGill University, McConnell Engineering Building, Room 363, 3480 Rue University, Montreal, QC H3A 2K6 Canada
- Human Health Therapeutics, National Research Council of Canada, Montreal, QC Canada
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83
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Barrett CT, Dutch RE. Viral Membrane Fusion and the Transmembrane Domain. Viruses 2020; 12:v12070693. [PMID: 32604992 PMCID: PMC7412173 DOI: 10.3390/v12070693] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 01/05/2023] Open
Abstract
Initiation of host cell infection by an enveloped virus requires a viral-to-host cell membrane fusion event. This event is mediated by at least one viral transmembrane glycoprotein, termed the fusion protein, which is a key therapeutic target. Viral fusion proteins have been studied for decades, and numerous critical insights into their function have been elucidated. However, the transmembrane region remains one of the most poorly understood facets of these proteins. In the past ten years, the field has made significant advances in understanding the role of the membrane-spanning region of viral fusion proteins. We summarize developments made in the past decade that have contributed to the understanding of the transmembrane region of viral fusion proteins, highlighting not only their critical role in the membrane fusion process, but further demonstrating their involvement in several aspects of the viral lifecycle.
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84
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Benton DJ, Gamblin SJ, Rosenthal PB, Skehel JJ. Structural transitions in influenza haemagglutinin at membrane fusion pH. Nature 2020; 583:150-153. [PMID: 32461688 PMCID: PMC7116728 DOI: 10.1038/s41586-020-2333-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/16/2020] [Indexed: 12/22/2022]
Abstract
Infection by enveloped viruses involves fusion of their lipid envelopes with cellular membranes to release the viral genome into cells. For HIV, Ebola, influenza and numerous other viruses, envelope glycoproteins bind the infecting virion to cell-surface receptors and mediate membrane fusion. In the case of influenza, the receptor-binding glycoprotein is the haemagglutinin (HA), and following receptor-mediated uptake of the bound virus by endocytosis1, it is the HA that mediates fusion of the virus envelope with the membrane of the endosome2. Each subunit of the trimeric HA consists of two disulfide-linked polypeptides, HA1 and HA2. The larger, virus-membrane-distal, HA1 mediates receptor binding; the smaller, membrane-proximal, HA2 anchors HA in the envelope and contains the fusion peptide, a region that is directly involved in membrane interaction3. The low pH of endosomes activates fusion by facilitating irreversible conformational changes in the glycoprotein. The structures of the initial HA at neutral pH and the final HA at fusion pH have been investigated by electron microscopy4,5 and X-ray crystallography6–8. Here, to further study the process of fusion, we incubate HA for different times at pH 5.0 and directly image structural changes using single-particle cryo-electron microscopy. We describe three distinct, previously undescribed forms of HA, most notably a 150 Å-long triple-helical coil of HA2, which may bridge between the viral and endosomal membranes. Comparison of these structures reveals concerted conformational rearrangements through which the HA mediates membrane fusion.
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Affiliation(s)
- Donald J Benton
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, London, UK.
| | - Steven J Gamblin
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, London, UK
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, London, UK.
| | - John J Skehel
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, London, UK
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85
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Benhaim MA, Mangala Prasad V, Garcia NK, Guttman M, Lee KK. Structural monitoring of a transient intermediate in the hemagglutinin fusion machinery on influenza virions. SCIENCE ADVANCES 2020; 6:eaaz8822. [PMID: 32494683 PMCID: PMC7190341 DOI: 10.1126/sciadv.aaz8822] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/05/2020] [Indexed: 05/16/2023]
Abstract
The influenza virus hemagglutinin (HA) fusion protein has long been viewed as a "spring-loaded" fusion machine whereby activation at low pH initiates a rapid and irreversible cascade of conformational changes that drives the membrane fusion reaction. This mechanism has shaped our understanding of how type 1 viral fusion proteins function as a whole. Experimental limitations have hindered efforts to expand our mechanistic and structural understanding of viral membrane fusion. Here, we used pulse-labeling hydrogen/deuterium exchange mass spectrometry and cryo-electron tomography to monitor and characterize the structural dynamics of HA during fusion activation on intact virions. Our data reveal how concurrent reorganizations at the HA1 receptor binding domain interface and HA2 fusion subunit produce a dynamic fusion intermediate ensemble in full-length HA. The soluble HA ectodomain transitions directly to the postfusion state with no observable intermediate.
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Affiliation(s)
- M. A. Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - V. Mangala Prasad
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - N. K. Garcia
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - M. Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - K. K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
- Biological Physics, Structure and Design Graduate Program, University of Washington, Seattle, WA, USA
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Corresponding author.
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86
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Rantalainen K, Berndsen ZT, Antanasijevic A, Schiffner T, Zhang X, Lee WH, Torres JL, Zhang L, Irimia A, Copps J, Zhou KH, Kwon YD, Law WH, Schramm CA, Verardi R, Krebs SJ, Kwong PD, Doria-Rose NA, Wilson IA, Zwick MB, Yates JR, Schief WR, Ward AB. HIV-1 Envelope and MPER Antibody Structures in Lipid Assemblies. Cell Rep 2020; 31:107583. [PMID: 32348769 PMCID: PMC7196886 DOI: 10.1016/j.celrep.2020.107583] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/05/2020] [Accepted: 04/07/2020] [Indexed: 11/25/2022] Open
Abstract
Structural and functional studies of HIV envelope glycoprotein (Env) as a transmembrane protein have long been complicated by challenges associated with inherent flexibility of the molecule and the membrane-embedded hydrophobic regions. Here, we present approaches for incorporating full-length, wild-type HIV-1 Env, as well as C-terminally truncated and stabilized versions, into lipid assemblies, providing a modular platform for Env structural studies by single particle electron microscopy. We reconstitute a full-length Env clone into a nanodisc, complex it with a membrane-proximal external region (MPER) targeting antibody 10E8, and structurally define the full quaternary epitope of 10E8 consisting of lipid, MPER, and ectodomain contacts. By aligning this and other Env-MPER antibody complex reconstructions with the lipid bilayer, we observe evidence of Env tilting as part of the neutralization mechanism for MPER-targeting antibodies. We also adapt the platform toward vaccine design purposes by introducing stabilizing mutations that allow purification of unliganded Env with a peptidisc scaffold.
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Affiliation(s)
- Kimmo Rantalainen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Zachary T Berndsen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Aleksandar Antanasijevic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Torben Schiffner
- Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xi Zhang
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jonathan L Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lei Zhang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Adriana Irimia
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffrey Copps
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kenneth H Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Young D Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - William H Law
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Chaim A Schramm
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Shelly J Krebs
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Michael B Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - William R Schief
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02129, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA.
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87
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Benhaim MA, Lee KK. New Biophysical Approaches Reveal the Dynamics and Mechanics of Type I Viral Fusion Machinery and Their Interplay with Membranes. Viruses 2020; 12:E413. [PMID: 32276357 PMCID: PMC7232462 DOI: 10.3390/v12040413] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/04/2020] [Accepted: 04/04/2020] [Indexed: 12/27/2022] Open
Abstract
Protein-mediated membrane fusion is a highly regulated biological process essential for cellular and organismal functions and infection by enveloped viruses. During viral entry the membrane fusion reaction is catalyzed by specialized protein machinery on the viral surface. These viral fusion proteins undergo a series of dramatic structural changes during membrane fusion where they engage, remodel, and ultimately fuse with the host membrane. The structural and dynamic nature of these conformational changes and their impact on the membranes have long-eluded characterization. Recent advances in structural and biophysical methodologies have enabled researchers to directly observe viral fusion proteins as they carry out their functions during membrane fusion. Here we review the structure and function of type I viral fusion proteins and mechanisms of protein-mediated membrane fusion. We highlight how recent technological advances and new biophysical approaches are providing unprecedented new insight into the membrane fusion reaction.
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Affiliation(s)
- Mark A. Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, USA;
| | - Kelly K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, USA;
- Biological Physics Structure and Design Program, University of Washington, Seattle, WA 98195-7610, USA
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88
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Direct visualization of avian influenza H5N1 hemagglutinin precursor and its conformational change by high-speed atomic force microscopy. Biochim Biophys Acta Gen Subj 2020; 1864:129313. [DOI: 10.1016/j.bbagen.2019.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/19/2019] [Accepted: 02/26/2019] [Indexed: 01/06/2023]
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89
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Lu Y, Landreth S, Liu G, Brownlie R, Gaba A, Littel-van den Hurk SVD, Gerdts V, Zhou Y. Innate immunemodulator containing adjuvant formulated HA based vaccine protects mice from lethal infection of highly pathogenic avian influenza H5N1 virus. Vaccine 2020; 38:2387-2395. [PMID: 32014270 DOI: 10.1016/j.vaccine.2020.01.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 01/16/2020] [Accepted: 01/18/2020] [Indexed: 01/17/2023]
Abstract
The highly pathogenic avian influenza (HPAI) H5N1 viruses and their spillover into the human population pose substantial economic and public health threats. Although antiviral drugs have some effect in treating influenza infection, vaccination is still the most effective intervention to prevent possible pandemic outbreaks. We have developed a novel H5 influenza vaccine to improve the world's pandemic preparedness. We produced a hemagglutinin (HA) of HPAI H5N1 virus A/Alberta/01/2014 (AB14) using both mammalian (m) and bacterial (b) expression systems. The purified recombinant proteins were formulated with a proprietary adjuvant (TriAdj) and their efficacy as vaccine candidates was evaluated in mice. Intramuscular delivery of two doses of TriAdj formulated mammalian expressed HA (m-HA/TriAdj) was shown to provide full protection against a lethal challenge of AB14 in mice. In contrast, bacterially expressed HA with TriAdj (b-HA/TriAdj), b-HA without adjuvant, and m-HA without adjuvant resulted in no protection in immunized mice. Furthermore, m-HA/TriAdj elicited significantly higher levels of balanced Th1 and Th2 responses and neutralizing antibody titres. All the mice in the m-HA/TriAdj group survived a lethal AB14 H5N1 challenge and showed no signs of disease or infection as demonstrated by no loss of body weight or detectable virus in the lungs. Our results suggest that m-HA formulated with TriAdj has potential to protect against pandemic H5N1 in the event of its cross over to the human host.
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Affiliation(s)
- Yao Lu
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada; Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Shelby Landreth
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada
| | - GuanQun Liu
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada
| | - Robert Brownlie
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada
| | - Amit Gaba
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada
| | - Sylvia van Drunen Littel-van den Hurk
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada; Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Volker Gerdts
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada; Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Yan Zhou
- Vaccine and Infectious Disease Organization - International Vaccine Center (VIDO-InterVac), University of Saskatchewan, Saskatoon, Canada; Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
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90
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Gadalla MR, Abrami L, van der Goot FG, Veit M. Hemagglutinin of Influenza A, but not of Influenza B and C viruses is acylated by ZDHHC2, 8, 15 and 20. Biochem J 2020; 477:285-303. [PMID: 31872235 DOI: 10.1042/bcj20190752] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/15/2019] [Accepted: 12/23/2019] [Indexed: 02/05/2023]
Abstract
Hemagglutinin (HA), a glycoprotein of Influenza A viruses and its proton channel M2 are site-specifically modified with fatty acids. Whereas two cysteines in the short cytoplasmic tail of HA contain only palmitate, stearate is exclusively attached to one cysteine located at the cytoplasmic border of the transmembrane region (TMR). M2 is palmitoylated at a cysteine positioned in an amphiphilic helix near the TMR. The enzymes catalyzing acylation of HA and M2 have not been identified, but zinc finger DHHC domain-containing (ZDHHC) palmitoyltransferases are candidates. We used a siRNA library to knockdown expression of each of the 23 human ZDHHCs in HA-expressing HeLa cells. siRNAs against ZDHHC2 and 8 had the strongest effect on acylation of HA as demonstrated by Acyl-RAC and confirmed by 3H-palmitate labeling. CRISPR/Cas9 knockout of ZDHHC2 and 8 in HAP1 cells, but also of the phylogenetically related ZDHHCs 15 and 20 strongly reduced acylation of group 1 and group 2 HAs and of M2, but individual ZDHHCs exhibit slightly different substrate preferences. These ZDHHCs co-localize with HA at membranes of the exocytic pathway in a human lung cell line. ZDHHC2, 8, 15 and 20 are not required for acylation of the HA-esterase-fusion protein of Influenza C virus that contains only stearate at one transmembrane cysteine. Knockout of these ZDHHCs also did not compromise acylation of HA of Influenza B virus that contains two palmitoylated cysteines in its cytoplasmic tail. Results are discussed with respect to the acyl preferences and possible substrate recognition features of the identified ZDHHCs.
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Affiliation(s)
- Mohamed Rasheed Gadalla
- Institute of Virology, Free University Berlin, 14163 Berlin, Germany
- Department of Virology, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt
| | - Laurence Abrami
- Global Health Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - F Gisou van der Goot
- Global Health Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Michael Veit
- Institute of Virology, Free University Berlin, 14163 Berlin, Germany
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91
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Pan J, Peng H, Chen B, Harrison SC. Cryo-EM Structure of Full-length HIV-1 Env Bound With the Fab of Antibody PG16. J Mol Biol 2020; 432:1158-1168. [PMID: 31931014 DOI: 10.1016/j.jmb.2019.11.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 11/29/2022]
Abstract
The HIV-1 envelope protein (Env) is the target of neutralizing antibodies and the template for vaccine immunogen design. The dynamic conformational equilibrium of trimeric Env influences its antigenicity and potential immunogenicity. Antibodies that bind at the trimer apex stabilize a "closed" conformation characteristic of the most difficult to neutralize isolates. A goal of vaccine development is therefore to mimic the closed conformation in a designed immunogen. A disulfide-stabilized, trimeric Env ectodomain-the "SOSIP" construct-has many of the relevant properties; it is also particularly suitable for structure determination. Some single-molecule studies have, however, suggested that the SOSIP trimer is not a good representation of Env on the surface of a virion or an infected cell. We isolated Env (fully cleaved to gp120 and gp41) from the surface of expressing cells using tagged, apex-binding Fab PG16 and determined the structure of the PG16-Env complex by cryo-EM to an overall resolution of 4.6 Å. Placing the only purification tag on the Fab ensured that the isolated Env was continuously stabilized in its closed, native conformation. The Env structure in this complex corresponds closely to the SOSIP structures determined by both x-ray crystallography and cryo-EM. Although the membrane-interacting elements are not resolved in our reconstruction, we can make inferences about the connection between ectodomain and membrane-proximal external region (MPER) by reference to the published cryo-tomography structure of an Env "spike" and the NMR structure of the MPER-transmembrane segment. We discuss these results in view of the conflicting interpretations in the literature.
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Affiliation(s)
- Junhua Pan
- Laboratory of Molecular Medicine, Boston Children's Hospital, 3 Blackfan Circle, Boston, MA, 02115, USA
| | - Hanqin Peng
- Laboratory of Molecular Medicine, Boston Children's Hospital, 3 Blackfan Circle, Boston, MA, 02115, USA
| | - Bing Chen
- Laboratory of Molecular Medicine, Boston Children's Hospital, 3 Blackfan Circle, Boston, MA, 02115, USA
| | - Stephen C Harrison
- Laboratory of Molecular Medicine, Boston Children's Hospital, 3 Blackfan Circle, Boston, MA, 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, 3 Blackfan Circle, Boston, MA, 02115, USA.
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92
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Gadalla MR, Veit M. Toward the identification of ZDHHC enzymes required for palmitoylation of viral protein as potential drug targets. Expert Opin Drug Discov 2019; 15:159-177. [PMID: 31809605 DOI: 10.1080/17460441.2020.1696306] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Introduction: S-acylation is the attachment of fatty acids not only to cysteines of cellular, but also of viral proteins. The modification is often crucial for the protein´s function and hence for virus replication. Transfer of fatty acids is mediated by one or several of the 23 members of the ZDHHC family of proteins. Since their genes are linked to various human diseases, they represent drug targets.Areas covered: The authors explore whether targeting acylation of viral proteins might be a strategy to combat viral diseases. Many human pathogens contain S-acylated proteins; the ZDHHCs involved in their acylation are currently identified. Based on the 3D structure of two ZDHHCs, the regulation and the biochemistry of the palmitolyation reaction and the lipid and protein substrate specificities are discussed. The authors then speculate how ZDHHCs might recognize S-acylated membrane proteins of Influenza virus.Expert opinion: Although many viral diseases can now be treated, the available drugs bind to viral proteins that rapidly mutate and become resistant. To develop inhibitors for the genetically more stable cellular ZDHHCs, their binding sites for viral substrates need to be identified. If only a few cellular proteins are recognized by the same binding site, development of specific inhibitors may have therapeutic potential.
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Affiliation(s)
- Mohamed Rasheed Gadalla
- Institute of Virology, Free University Berlin, Berlin, Germany.,Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Michael Veit
- Institute of Virology, Free University Berlin, Berlin, Germany
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93
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Topological analysis of the gp41 MPER on lipid bilayers relevant to the metastable HIV-1 envelope prefusion state. Proc Natl Acad Sci U S A 2019; 116:22556-22566. [PMID: 31624123 DOI: 10.1073/pnas.1912427116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The membrane proximal external region (MPER) of HIV-1 envelope glycoprotein (gp) 41 is an attractive vaccine target for elicitation of broadly neutralizing antibodies (bNAbs) by vaccination. However, current details regarding the quaternary structural organization of the MPER within the native prefusion trimer [(gp120/41)3] are elusive and even contradictory, hindering rational MPER immunogen design. To better understand the structural topology of the MPER on the lipid bilayer, the adjacent transmembrane domain (TMD) was appended (MPER-TMD) and studied. Membrane insertion of the MPER-TMD was sensitive both to the TMD sequence and cytoplasmic residues. Antigen binding of MPER-specific bNAbs, in particular 10E8 and DH511.2_K3, was significantly impacted by the presence of the TMD. Furthermore, MPER-TMD assembly into 10-nm diameter nanodiscs revealed a heterogeneous membrane array comprised largely of monomers and dimers, as enumerated by bNAb Fab binding using single-particle electron microscopy analysis, arguing against preferential trimeric association of native MPER and TMD protein segments. Moreover, introduction of isoleucine mutations in the C-terminal heptad repeat to induce an extended MPER α-helical bundle structure yielded an antigenicity profile of cell surface-arrayed Env variants inconsistent with that found in the native prefusion state. In line with these observations, electron paramagnetic resonance analysis suggested that 10E8 inhibits viral membrane fusion by lifting the MPER N-terminal region out of the viral membrane, mandating the exposure of residues that would be occluded by MPER trimerization. Collectively, our data suggest that the MPER is not a stable trimer, but rather a dynamic segment adapted for structural changes accompanying fusion.
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Biochemical Analysis of Coronavirus Spike Glycoprotein Conformational Intermediates during Membrane Fusion. J Virol 2019; 93:JVI.00785-19. [PMID: 31315988 PMCID: PMC6744234 DOI: 10.1128/jvi.00785-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/05/2019] [Indexed: 11/20/2022] Open
Abstract
A fusion protein expressed on the surface of enveloped viruses mediates fusion of the viral and cellular membranes to facilitate virus infection. Pre- and postfusion structures of viral fusion proteins have been characterized, but conformational changes between them remain poorly understood. Here, we examined the intermediate conformation of the murine coronavirus fusion protein, called the spike protein, which must be cleaved by a cellular protease following receptor binding. Western blot analysis of protease digestion products revealed that two subunits (67 and 69 kDa) are produced from a single spike protein (180 kDa). These two subunits were considered to be by-products derived from conformational changes and were useful for probing the intermediate conformation of the spike protein. Interaction with a heptad repeat (HR) peptide revealed that these subunits adopt packed and unpacked conformations, respectively, and two-dimensional electrophoresis revealed a trimeric assembly. Based on biochemical observations, we propose an asymmetric trimer model for the intermediate structure of the spike protein. Receptor binding induces the membrane-binding potential of the trimer, in which at least one HR motif forms a packed-hairpin structure, while membrane fusion subunits are covered by the receptor-binding subunit, thereby preventing the spike protein from forming the typical homotrimeric prehairpin structure predicted by the current model of class I viral fusion protein. Subsequent proteolysis induces simultaneous packing of the remaining unpacked HRs upon assembly of three HRs at the central axis to generate a six-helix bundle. Our model proposes a key mechanism for membrane fusion of enveloped viruses.IMPORTANCE Recent studies using single-particle cryo-electron microscopy (cryoEM) revealed the mechanism underlying activation of viral fusion protein at the priming stage. However, characterizing the subsequent triggering stage underpinning transition from pre- to postfusion structures is difficult because single-particle cryoEM excludes unstable structures that appear as heterogeneous shapes. Therefore, population-based biochemical analysis is needed to capture features of unstable proteins. Here, we analyzed protease digestion products of a coronavirus fusion protein during activation; their sizes appear to be affected directly by the conformational state. We propose a model for the viral fusion protein in the intermediate state, which involves a compact structure and conformational changes that overcome steric hindrance within the three fusion protein subunits.
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95
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Cholesterol Binding to the Transmembrane Region of a Group 2 Hemagglutinin (HA) of Influenza Virus Is Essential for Virus Replication, Affecting both Virus Assembly and HA Fusion Activity. J Virol 2019; 93:JVI.00555-19. [PMID: 31118253 DOI: 10.1128/jvi.00555-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/14/2019] [Indexed: 12/21/2022] Open
Abstract
Hemagglutinin (HA) of influenza virus is incorporated into cholesterol-enriched nanodomains of the plasma membrane. Phylogenetic group 2 HAs contain the conserved cholesterol consensus motif (CCM) YKLW in the transmembrane region. We previously reported that mutations in the CCM retarded intracellular transport of HA and decreased its nanodomain association. Here, we analyzed whether cholesterol interacts with the CCM. Incorporation of photocholesterol into HA was significantly reduced if the whole CCM is replaced by alanine, both using immunoprecipitated HA and when HA is embedded in the membrane. We next used reverse genetics to investigate the significance of the CCM for virus replication. No virus was rescued if the whole motif is exchanged (YKLW4A); singly (LA) or doubly (YK2A and LW2A) mutated virus showed decreased titers and a comparative fitness disadvantage. In polarized cells, transport of HA mutants to the apical membrane was not disturbed. Reduced amounts of HA and cholesterol were incorporated into the viral membrane. Mutant viruses exhibit a decrease in hemolysis, which is only partially corrected if the membrane is replenished with cholesterol. More specifically, viruses have a defect in hemifusion, as demonstrated by fluorescence dequenching. Cells expressing HA YKLW4A fuse with erythrocytes, but the number of events is reduced. Even after acidification unfused erythrocytes remain cell bound, a phenomenon not observed with wild-type HA. We conclude that cholesterol binding to a group 2 HA is essential for virus replication. It has pleiotropic effects on virus assembly and membrane fusion, mainly on lipid mixing and possibly a preceding step.IMPORTANCE The glycoprotein HA is a major pathogenicity factor of influenza viruses. Whereas the structure and function of HA's ectodomain is known in great detail, similar data for the membrane-anchoring part of the protein are missing. Here, we demonstrate that the transmembrane region of a group 2 HA interacts with cholesterol, the major lipid of the plasma membrane and the defining element of the viral budding site nanodomains of the plasma membrane. The cholesterol binding motif is essential for virus replication. Its partial removal affects various steps of the viral life cycle, such as assembly of new virus particles and their subsequent cell entry via membrane fusion. A cholesterol binding pocket in group 2 HAs might be a promising target for a small lipophilic drug that inactivates the virus.
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96
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Ranaweera A, Ratnayake PU, Ekanayaka EAP, Declercq R, Weliky DP. Hydrogen-Deuterium Exchange Supports Independent Membrane-Interfacial Fusion Peptide and Transmembrane Domains in Subunit 2 of Influenza Virus Hemagglutinin Protein, a Structured and Aqueous-Protected Connection between the Fusion Peptide and Soluble Ectodomain, and the Importance of Membrane Apposition by the Trimer-of-Hairpins Structure. Biochemistry 2019; 58:2432-2446. [PMID: 31008587 DOI: 10.1021/acs.biochem.8b01272] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The influenza virus hemagglutinin (HA) protein has HA1 and HA2 subunits, which form an initial complex. HA1's bind host cell sialic acids, which triggers endocytosis, HA1/HA2 separation, and HA2-mediated fusion between virus and endosome membranes. We report hydrogen-deuterium exchange mass spectrometry (HDX-MS) on the HA2 subunit without HA1. HA2 contains the fusion peptide (FP), soluble ectodomain (SE), transmembrane domain (TM), and endodomain. FP is a monomer by itself, while SE is a trimer of hairpins that includes an interior bundle of residue 38-105 helices, turns, and residue 154-178 strands packed antiparallel to the bundle. FP and TM extend from the same side of the SE hairpin, and fusion models often depict a FP/TM complex with membrane traversal of both domains that is important for membrane pore expansion. The HDX-MS data of this study do not support this complex and instead support independent FP and TM with respective membrane-interfacial and traversal locations. The data also show a low level of aqueous exposure of the 22-38 segment, consistent with retention of the 23-35 antiparallel β sheet observed in the initial HA1/HA2 complex. We propose the β sheet as a semirigid connector between FP and SE that enables close membrane apposition prior to fusion. The I173E mutant exhibits greater exchange for residues 22-69 and 150-191, consistent with dissociation of SE C-terminal strands from interior N-helices. Similar trends are observed for the G1E mutant as well as less exchange for G1E FP. Fusion is highly impaired with either mutant, which correlates with reduced membrane apposition and, for G1E, FP binding to SE rather than the target membrane.
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Affiliation(s)
- Ahinsa Ranaweera
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Punsisi U Ratnayake
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - E A Prabodha Ekanayaka
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Robin Declercq
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - David P Weliky
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
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97
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Han L, Chen C, Han X, Lin S, Ao X, Han X, Wang J, Ye H. Structural Insights for Anti-Influenza Vaccine Design. Comput Struct Biotechnol J 2019; 17:475-483. [PMID: 31007873 PMCID: PMC6458449 DOI: 10.1016/j.csbj.2019.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/17/2019] [Accepted: 03/21/2019] [Indexed: 01/29/2023] Open
Abstract
Influenza A virus are a persistent and significant threat to human health, and current vaccines do not provide sufficient protection due to antigenic drift, which allows influenza viruses to easily escape immune surveillance and antiviral drug activity. Influenza hemagglutinin (HA) is a glycoprotein needed for the entry of enveloped influenza viruses into host cells and is a potential target for anti-influenza humoral immune responses. In recent years, a number of broadly neutralizing antibodies (bnAbs) have been isolated, and their relative structural information obtained from the crystallization of influenza antigens in complex with bnAbs has provided some new insights into future influenza vaccine research. Here, we review the current knowledge of the HA-targeted bnAbs and the structure-based mechanisms contributing to neutralization. We also discuss the potential for this structure-based approach to overcome the challenge of obtaining a highly desired "universal" influenza vaccine, especially on small proteins and peptides.
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Affiliation(s)
- Lifen Han
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, China
- College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Cong Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, China
| | - Xianlin Han
- Department of General Surgery, Peking Union Medical College Hospital, Beijing, China
| | - Shujin Lin
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, China
| | - Xiulan Ao
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, China
| | - Xiao Han
- College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Jianmin Wang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, China
| | - Hanhui Ye
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, China
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