1
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López CA, Alam SM, Derdeyn CA, Haynes BF, Gnanakaran S. Influence of membrane on the antigen presentation of the HIV-1 envelope membrane proximal external region (MPER). Curr Opin Struct Biol 2024; 88:102897. [PMID: 39173417 DOI: 10.1016/j.sbi.2024.102897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/18/2024] [Accepted: 07/19/2024] [Indexed: 08/24/2024]
Abstract
The membrane proximal external region (MPER) of the HIV envelope glycoproteins has generated renewed interest after a recent phase I vaccine trial that presented MPER lipid-peptide epitopes demonstrated promise to elicit a broad neutralization response. The antigenicity of MPER is intimately associated with the membrane, and its presentation relies significantly on the lipid composition. This review brings together recent findings on the influence of membranes on the conformation of MPER and its recognition by broadly neutralizing antibodies. Specifically, the review highlights the importance of properly accounting for the balance between protein-protein and membrane-protein interactions in vaccine design.
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Affiliation(s)
- Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - S Munir Alam
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Cynthia A Derdeyn
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Barton F Haynes
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA; Department of Immunology, Duke University of School of Medicine, Durham, NC, USA.
| | - Sandrasegaram Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
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2
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Zhang Z, Anang S, Nguyen HT, Fritschi C, Smith AB, Sodroski JG. Membrane HIV-1 envelope glycoproteins stabilized more strongly in a pretriggered conformation than natural virus Envs. iScience 2024; 27:110141. [PMID: 38979012 PMCID: PMC11228805 DOI: 10.1016/j.isci.2024.110141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/08/2024] [Accepted: 05/27/2024] [Indexed: 07/10/2024] Open
Abstract
The pretriggered conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ((gp120/gp41)3) is targeted by virus entry inhibitors and broadly neutralizing antibodies (bNAbs). The lability of pretriggered Env has hindered its characterization. Here, we produce membrane Env variants progressively stabilized in pretriggered conformations, in some cases to a degree beyond that found in natural HIV-1 strains. Pretriggered Env stability correlated with stronger trimer subunit association, increased virus sensitivity to bNAb neutralization, and decreased capacity to mediate cell-cell fusion and virus entry. For some highly stabilized Env mutants, after virus-host cell engagement, the normally inaccessible gp120 V3 region on an Env intermediate became targetable by otherwise poorly neutralizing antibodies. Thus, evolutionary pressure on HIV-1 Env to maintain trimer integrity, responsiveness to the CD4 receptor, and resistance to antibodies modulates pretriggered Env stability. The strongly stabilized pretriggered membrane Envs reported here will facilitate further characterization of this functionally important conformation.
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Affiliation(s)
- Zhiqing Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Saumya Anang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Hanh T Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher Fritschi
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amos B Smith
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
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3
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Kočar E, Katz S, Pušnik Ž, Bogovič P, Turel G, Skubic C, Režen T, Strle F, Martins dos Santos VA, Mraz M, Moškon M, Rozman D. COVID-19 and cholesterol biosynthesis: Towards innovative decision support systems. iScience 2023; 26:107799. [PMID: 37720097 PMCID: PMC10502404 DOI: 10.1016/j.isci.2023.107799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/12/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023] Open
Abstract
With COVID-19 becoming endemic, there is a continuing need to find biomarkers characterizing the disease and aiding in patient stratification. We studied the relation between COVID-19 and cholesterol biosynthesis by comparing 10 intermediates of cholesterol biosynthesis during the hospitalization of 164 patients (admission, disease deterioration, discharge) admitted to the University Medical Center of Ljubljana. The concentrations of zymosterol, 24-dehydrolathosterol, desmosterol, and zymostenol were significantly altered in COVID-19 patients. We further developed a predictive model for disease severity based on clinical parameters alone and their combination with a subset of sterols. Our machine learning models applying 8 clinical parameters predicted disease severity with excellent accuracy (AUC = 0.96), showing substantial improvement over current clinical risk scores. After including sterols, model performance remained better than COVID-GRAM. This is the first study to examine cholesterol biosynthesis during COVID-19 and shows that a subset of cholesterol-related sterols is associated with the severity of COVID-19.
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Affiliation(s)
- Eva Kočar
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, SI-1000 Ljubljana, Slovenia
| | - Sonja Katz
- LifeGlimmer GmbH, Markelstraße 38, 12163 Berlin, Germany
- Biomanufacturing and Digital Twins Group, Bioprocess Engineering Laboratory, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, the Netherlands
| | - Žiga Pušnik
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Petra Bogovič
- Department of Infectious Diseases, University Medical Centre Ljubljana, Japljeva ulica 2, SI-1000 Ljubljana, Slovenia
| | - Gabriele Turel
- Department of Infectious Diseases, University Medical Centre Ljubljana, Japljeva ulica 2, SI-1000 Ljubljana, Slovenia
| | - Cene Skubic
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, SI-1000 Ljubljana, Slovenia
| | - Tadeja Režen
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, SI-1000 Ljubljana, Slovenia
| | - Franc Strle
- Department of Infectious Diseases, University Medical Centre Ljubljana, Japljeva ulica 2, SI-1000 Ljubljana, Slovenia
| | - Vitor A.P. Martins dos Santos
- LifeGlimmer GmbH, Markelstraße 38, 12163 Berlin, Germany
- Biomanufacturing and Digital Twins Group, Bioprocess Engineering Laboratory, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, the Netherlands
| | - Miha Mraz
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Miha Moškon
- Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Damjana Rozman
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, SI-1000 Ljubljana, Slovenia
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4
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Zhang Z, Wang Q, Nguyen HT, Chen HC, Chiu TJ, Smith Iii AB, Sodroski JG. Alterations in gp120 glycans or the gp41 fusion peptide-proximal region modulate the stability of the human immunodeficiency virus (HIV-1) envelope glycoprotein pretriggered conformation. J Virol 2023; 97:e0059223. [PMID: 37696048 PMCID: PMC10537687 DOI: 10.1128/jvi.00592-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/07/2023] [Indexed: 09/13/2023] Open
Abstract
The human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer mediates entry into host cells by binding receptors, CD4 and CCR5/CXCR4, and fusing the viral and cell membranes. In infected cells, cleavage of the gp160 Env precursor yields the mature Env trimer, with gp120 exterior and gp41 transmembrane Env subunits. Env cleavage stabilizes the State-1 conformation, which is the major target for broadly neutralizing antibodies, and decreases the spontaneous sampling of more open Env conformations that expose epitopes for poorly neutralizing antibodies. During HIV-1 entry into cells, CD4 binding drives the metastable Env from a pretriggered (State-1) conformation into more "open," lower-energy states. Here, we report that changes in two dissimilar elements of the HIV-1 Env trimer, namely particular gp120 glycans and the gp41 fusion peptide-proximal region (FPPR), can independently modulate the stability of State 1. Individual deletion of several gp120 glycans destabilized State 1, whereas removal of a V1 glycan resulted in phenotypes indicative of a more stable pretriggered Env conformation. Likewise, some alterations of the gp41 FPPR decreased the level of spontaneous shedding of gp120 from the Env trimer and stabilized the pretriggered State-1 Env conformation. State-1-stabilizing changes were additive and could suppress the phenotypes associated with State-1-destabilizing alterations in Env. Our results support a model in which multiple protein and carbohydrate elements of the HIV-1 Env trimer additively contribute to the stability of the pretriggered (State-1) conformation. The Env modifications identified in this study will assist efforts to characterize the structure and immunogenicity of the metastable State-1 conformation. IMPORTANCE The elicitation of antibodies that neutralize multiple strains of HIV-1 is an elusive goal that has frustrated the development of an effective vaccine. The pretriggered shape of the HIV-1 envelope glycoprotein (Env) spike on the virus surface is the major target for such broadly neutralizing antibodies. The "closed" pretriggered Env shape resists the binding of most antibodies but is unstable and often assumes "open" shapes that elicit ineffective antibodies. We identified particular changes in both the protein and the sugar components of the Env trimer that stabilize the pretriggered shape. Combinations of these changes were even more effective at stabilizing the pretriggered Env than the individual changes. Stabilizing changes in Env could counteract the effect of Env changes that destabilize the pretriggered shape. Locking Env in its pretriggered shape will assist efforts to understand the Env spike on the virus and to incorporate this shape into vaccines.
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Affiliation(s)
- Zhiqing Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute , Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School , Boston, Massachusetts, USA
| | - Qian Wang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute , Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School , Boston, Massachusetts, USA
| | - Hanh T Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute , Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School , Boston, Massachusetts, USA
| | - Hung-Ching Chen
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania, USA
| | - Ta-Jung Chiu
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania, USA
| | - Amos B Smith Iii
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute , Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School , Boston, Massachusetts, USA
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5
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Tong T, D’Addabbo A, Xu J, Chawla H, Nguyen A, Ochoa P, Crispin M, Binley JM. Impact of stabilizing mutations on the antigenic profile and glycosylation of membrane-expressed HIV-1 envelope glycoprotein. PLoS Pathog 2023; 19:e1011452. [PMID: 37549185 PMCID: PMC10434953 DOI: 10.1371/journal.ppat.1011452] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/17/2023] [Accepted: 07/16/2023] [Indexed: 08/09/2023] Open
Abstract
Recent HIV-1 vaccine development has centered on "near native" soluble envelope glycoprotein (Env) trimers that are artificially stabilized laterally (between protomers) and apically (between gp120 and gp41). These mutations have been leveraged for use in membrane-expressed Env mRNA vaccines, although their effects in this context are unclear. To address this question, we used virus-like particle (VLP) produced in 293T cells. Uncleaved (UNC) trimers were laterally unstable upon gentle lysis from membranes. However, gp120/gp41 processing improved lateral stability. Due to inefficient gp120/gp41 processing, UNC is incorporated into VLPs. A linker between gp120 and gp41 neither improved trimer stability nor its antigenic profile. An artificially introduced enterokinase cleavage site allowed post-expression gp120/gp41 processing, concomitantly increasing trimer stability. Gp41 N-helix mutations I559P and NT1-5 imparted lateral trimer stability, but also reduced gp120/gp41 processing and/or impacted V2 apex and interface NAb binding. I559P consistently reduced recognition by HIV+ human plasmas, further supporting antigenic differences. Mutations in the gp120 bridging sheet failed to stabilize membrane trimers in a pre-fusion conformation, and also reduced gp120/gp41 processing and exposed non-neutralizing epitopes. Reduced glycan maturation and increased sequon skipping were common side effects of these mutations. In some cases, this may be due to increased rigidity which limits access to glycan processing enzymes. In contrast, viral gp120 did not show glycan skipping. A second, minor species of high mannose gp160 was unaffected by any mutations and instead bypasses normal folding and glycan maturation. Including the full gp41 cytoplasmic tail led to markedly reduced gp120/gp41 processing and greatly increased the proportion of high mannose gp160. Remarkably, monoclonal antibodies were unable to bind to this high mannose gp160 in native protein gels. Overall, our findings suggest caution in leveraging stabilizing mutations in nucleic acid-based immunogens to ensure they impart valuable membrane trimer phenotypes for vaccine use.
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Affiliation(s)
- Tommy Tong
- San Diego Biomedical Research Institute, San Diego, California, United States of America
| | - Alessio D’Addabbo
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Jiamin Xu
- San Diego Biomedical Research Institute, San Diego, California, United States of America
| | - Himanshi Chawla
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Albert Nguyen
- San Diego Biomedical Research Institute, San Diego, California, United States of America
| | - Paola Ochoa
- San Diego Biomedical Research Institute, San Diego, California, United States of America
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - James M. Binley
- San Diego Biomedical Research Institute, San Diego, California, United States of America
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6
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Leonhardt SA, Purdy MD, Grover JR, Yang Z, Poulos S, McIntire WE, Tatham EA, Erramilli SK, Nosol K, Lai KK, Ding S, Lu M, Uchil PD, Finzi A, Rein A, Kossiakoff AA, Mothes W, Yeager M. Antiviral HIV-1 SERINC restriction factors disrupt virus membrane asymmetry. Nat Commun 2023; 14:4368. [PMID: 37474505 PMCID: PMC10359404 DOI: 10.1038/s41467-023-39262-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 06/06/2023] [Indexed: 07/22/2023] Open
Abstract
The host proteins SERINC3 and SERINC5 are HIV-1 restriction factors that reduce infectivity when incorporated into the viral envelope. The HIV-1 accessory protein Nef abrogates incorporation of SERINCs via binding to intracellular loop 4 (ICL4). Here, we determine cryoEM maps of full-length human SERINC3 and an ICL4 deletion construct, which reveal that hSERINC3 is comprised of two α-helical bundles connected by a ~ 40-residue, highly tilted, "crossmember" helix. The design resembles non-ATP-dependent lipid transporters. Consistently, purified hSERINCs reconstituted into proteoliposomes induce flipping of phosphatidylserine (PS), phosphatidylethanolamine and phosphatidylcholine. Furthermore, SERINC3, SERINC5 and the scramblase TMEM16F expose PS on the surface of HIV-1 and reduce infectivity, with similar results in MLV. SERINC effects in HIV-1 and MLV are counteracted by Nef and GlycoGag, respectively. Our results demonstrate that SERINCs are membrane transporters that flip lipids, resulting in a loss of membrane asymmetry that is strongly correlated with changes in Env conformation and loss of infectivity.
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Grants
- P01 AI150471 NIAID NIH HHS
- P41 GM103311 NIGMS NIH HHS
- G20 RR031199 NCRR NIH HHS
- R01 GM117372 NIGMS NIH HHS
- U54 AI170856 NIAID NIH HHS
- S10 OD018149 NIH HHS
- U24 GM129539 NIGMS NIH HHS
- S10 RR025067 NCRR NIH HHS
- This work was supported by the National Institutes of Health (NIH) grants P50 AI15046 and U54 AI170856-01 (M.Y., W.M. and A.K.K.), R01 AI154092 (M.Y.), R01 GM117372 (A.A.K.) and P01 AI150471 (W.M.)., by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research, and in part by the NIH Intramural AIDS Targeted Antiviral Program. S.D. and A.F. were supported by the CIHR grant 352417 and a Canada Research Chair. Some molecular graphics and analyses were performed with the University of California, San Francisco Chimera package. Chimera is developed by the Resource for Biocomputing, Visualization, and Informatics at the University of California, San Francisco (supported by the National Institute of General Medical Sciences Grant P41 GM103311).
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Affiliation(s)
- Susan A Leonhardt
- The Phillip and Patricia Frost Institute for Chemistry and Molecular Science, University of Miami, Coral Gables, FL, 33146, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Michael D Purdy
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
- Molecular Electron Microscopy Core, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Jonathan R Grover
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Ziwei Yang
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Sandra Poulos
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - William E McIntire
- The Phillip and Patricia Frost Institute for Chemistry and Molecular Science, University of Miami, Coral Gables, FL, 33146, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Elizabeth A Tatham
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Kamil Nosol
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Kin Kui Lai
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, P.O. Box B, Building 535, Frederick, MD, 21702, USA
| | - Shilei Ding
- Centre de Recherche du CHUM (CRCHUM), Montreal, QC, Canada
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
- Department of Cellular and Molecular Biology, University of Texas Health Science Center, Tyler, TX, USA
| | - Pradeep D Uchil
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM (CRCHUM), Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - Alan Rein
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, P.O. Box B, Building 535, Frederick, MD, 21702, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06510, USA.
| | - Mark Yeager
- The Phillip and Patricia Frost Institute for Chemistry and Molecular Science, University of Miami, Coral Gables, FL, 33146, USA.
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
- Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
- Department of Chemistry, University of Miami, Coral Gables, FL, 33146, USA.
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, FL, 33136, USA.
- Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
- Department of Medicine, Division of Cardiovascular Medicine, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
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7
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Zhou R, Zhang S, Nguyen HT, Ding H, Gaffney A, Kappes JC, Smith AB, Sodroski JG. Conformations of Human Immunodeficiency Virus Envelope Glycoproteins in Detergents and Styrene-Maleic Acid Lipid Particles. J Virol 2023; 97:e0032723. [PMID: 37255444 PMCID: PMC10308955 DOI: 10.1128/jvi.00327-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/10/2023] [Indexed: 06/01/2023] Open
Abstract
The mature human immunodeficiency virus (HIV) envelope glycoprotein (Env) trimer, which consists of noncovalently associated gp120 exterior and gp41 transmembrane subunits, mediates virus entry into cells. The pretriggered (State-1) Env conformation is the major target for broadly neutralizing antibodies (bNAbs), whereas receptor-induced downstream Env conformations elicit immunodominant, poorly neutralizing antibody (pNAb) responses. To examine the contribution of membrane anchorage to the maintenance of the metastable pretriggered Env conformation, we compared wild-type and State-1-stabilized Envs solubilized in detergents or in styrene-maleic acid (SMA) copolymers. SMA directly incorporates membrane lipids and resident membrane proteins into lipid nanoparticles (styrene-maleic acid lipid particles [SMALPs]). The integrity of the Env trimer in SMALPs was maintained at both 4°C and room temperature. In contrast, Envs solubilized in Cymal-5, a nonionic detergent, were unstable at room temperature, although their stability was improved at 4°C and/or after incubation with the entry inhibitor BMS-806. Envs solubilized in ionic detergents were relatively unstable at either temperature. Comparison of Envs solubilized in Cymal-5 and SMA at 4°C revealed subtle differences in bNAb binding to the gp41 membrane-proximal external region, consistent with these distinct modes of Env solubilization. Otherwise, the antigenicity of the Cymal-5- and SMA-solubilized Envs was remarkably similar, both in the absence and in the presence of BMS-806. However, both solubilized Envs were recognized differently from the mature membrane Env by specific bNAbs and pNAbs. Thus, detergent-based and detergent-free solubilization at 4°C alters the pretriggered membrane Env conformation in consistent ways, suggesting that Env assumes default conformations when its association with the membrane is disrupted. IMPORTANCE The human immunodeficiency virus (HIV) envelope glycoproteins (Envs) in the viral membrane mediate virus entry into the host cell and are targeted by neutralizing antibodies elicited by natural infection or vaccines. Detailed studies of membrane proteins rely on purification procedures that allow the proteins to maintain their natural conformation. In this study, we show that a styrene-maleic acid (SMA) copolymer can extract HIV-1 Env from a membrane without the use of detergents. The Env in SMA is more stable at room temperature than Env in detergents. The purified Env in SMA maintains many but not all of the characteristics expected of the natural membrane Env. Our results underscore the importance of the membrane environment to the native conformation of HIV-1 Env. Purification methods that bypass the need for detergents could be useful tools for future studies of HIV-1 Env structure and its interaction with receptors and antibodies.
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Affiliation(s)
- Rong Zhou
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shijian Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Hanh T. Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama, USA
| | - Althea Gaffney
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama, USA
| | - Amos B. Smith
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joseph G. Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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8
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Wang K, Zhang S, Go EP, Ding H, Wang WL, Nguyen HT, Kappes JC, Desaire H, Sodroski J, Mao Y. Asymmetric conformations of cleaved HIV-1 envelope glycoprotein trimers in styrene-maleic acid lipid nanoparticles. Commun Biol 2023; 6:535. [PMID: 37202420 PMCID: PMC10195785 DOI: 10.1038/s42003-023-04916-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/04/2023] [Indexed: 05/20/2023] Open
Abstract
During virus entry, the pretriggered human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer initially transits into a default intermediate state (DIS) that remains structurally uncharacterized. Here, we present cryo-EM structures at near-atomic resolution of two cleaved full-length HIV-1 Env trimers purified from cell membranes in styrene-maleic acid lipid nanoparticles without antibodies or receptors. The cleaved Env trimers exhibited tighter subunit packing than uncleaved trimers. Cleaved and uncleaved Env trimers assumed remarkably consistent yet distinct asymmetric conformations, with one smaller and two larger opening angles. Breaking conformational symmetry is allosterically coupled with dynamic helical transformations of the gp41 N-terminal heptad repeat (HR1N) regions in two protomers and with trimer tilting in the membrane. The broken symmetry of the DIS potentially assists Env binding to two CD4 receptors-while resisting antibody binding-and promotes extension of the gp41 HR1 helical coiled-coil, which relocates the fusion peptide closer to the target cell membrane.
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Affiliation(s)
- Kunyu Wang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China
- Peking-Tsinghua Joint Center for Life Science, Peking University, Beijing, China
| | - Shijian Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Eden P Go
- Department of Chemistry, University of Kansas, Lawrence, KS, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wei Li Wang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China
| | - Hanh T Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL, USA
| | - Heather Desaire
- Department of Chemistry, University of Kansas, Lawrence, KS, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Youdong Mao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China.
- Peking-Tsinghua Joint Center for Life Science, Peking University, Beijing, China.
- Center for Quantitative Biology, Academy of Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- National Biomedical Imaging Center, Peking University, Beijing, China.
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9
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Nguyen HT, Wang Q, Anang S, Sodroski JG. Characterization of the Human Immunodeficiency Virus (HIV-1) Envelope Glycoprotein Conformational States on Infectious Virus Particles. J Virol 2023; 97:e0185722. [PMID: 36815832 PMCID: PMC10062176 DOI: 10.1128/jvi.01857-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
Human immunodeficiency virus (HIV-1) entry into cells involves triggering of the viral envelope glycoprotein (Env) trimer ([gp120/gp41]3) by the primary receptor, CD4, and coreceptors, CCR5 or CXCR4. The pretriggered (State-1) conformation of the mature (cleaved) Env is targeted by broadly neutralizing antibodies (bNAbs), which are inefficiently elicited compared with poorly neutralizing antibodies (pNAbs). Here, we characterize variants of the moderately triggerable HIV-1AD8 Env on virions produced by an infectious molecular proviral clone; such virions contain more cleaved Env than pseudotyped viruses. We identified three types of cleaved wild-type AD8 Env trimers on virions: (i) State-1-like trimers preferentially recognized by bNAbs and exhibiting strong subunit association; (ii) trimers recognized by pNAbs directed against the gp120 coreceptor-binding region and exhibiting weak, detergent-sensitive subunit association; and (iii) a minor gp41-only population. The first Env population was enriched and the other Env populations reduced by introducing State-1-stabilizing changes in the AD8 Env or by treatment of the virions with crosslinker or the State-1-preferring entry inhibitor, BMS-806. These stabilized AD8 Envs were also more resistant to gp120 shedding induced by a CD4-mimetic compound or by incubation on ice. Conversely, a State-1-destabilized, CD4-independent AD8 Env variant exhibited weaker bNAb recognition and stronger pNAb recognition. Similar relationships between Env triggerability and antigenicity/shedding propensity on virions were observed for other HIV-1 strains. State-1 Envs on virions can be significantly enriched by minimizing the adventitious incorporation of uncleaved Env; stabilizing the pretriggered conformation by Env modification, crosslinking or BMS-806 treatment; strengthening Env subunit interactions; and using CD4-negative producer cells. IMPORTANCE Efforts to develop an effective HIV-1 vaccine have been frustrated by the inability to elicit broad neutralizing antibodies that recognize multiple virus strains. Such antibodies can bind a particular shape of the HIV-1 envelope glycoprotein trimer, as it exists on a viral membrane but before engaging receptors on the host cell. Here, we establish simple yet powerful assays to characterize the envelope glycoproteins in a natural context on virus particles. We find that, depending on the HIV-1 strain, some envelope glycoproteins change shape and fall apart, creating decoys that can potentially divert the host immune response. We identify requirements to keep the relevant envelope glycoprotein target for broad neutralizing antibodies intact on virus-like particles. These studies suggest strategies that should facilitate efforts to produce and use virus-like particles as vaccine immunogens.
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Affiliation(s)
- Hanh T. Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Qian Wang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Saumya Anang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Joseph G. Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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10
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Alfadhli A, Romanaggi C, Barklis RL, Barklis E. Analysis of HIV-1 envelope cytoplasmic tail effects on viral replication. Virology 2023; 579:54-66. [PMID: 36603533 PMCID: PMC10003682 DOI: 10.1016/j.virol.2022.12.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
Trimers of the HIV-1 envelope (Env) protein perform receptor binding and virus-cell fusion functions during the virus life cycle. The cytoplasmic tail (CT) of Env forms an unusual baseplate structure, and is palmitoylated, rich in arginines, carries trafficking motifs, binds cholesterol, and interacts with host proteins. To dissect CT activities, we examined a panel of Env variants, including CT truncations, mutations, and an extension. We found that whereas all variants could replicate in permissive cells, viruses with CT truncations or baseplate mutations were defective in restrictive cells. We also identified a determinant in HIV-1 amphotericin sensitivity, and characterized variants that escape amphotericin inhibition via viral protease-mediated CT cleavage. Results additionally showed that full-length, his tagged Env can oligomerize and be co-assembled with CT truncations that delete portions of the baseplate, host protein binding sites, and trafficking signals. Our observations illuminate novel aspects of HIV-1 CT structure, interactions, and functions.
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Affiliation(s)
- Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - CeAnn Romanaggi
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA.
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11
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Jackman JA, Lavergne TA, Elrod CC. Antimicrobial monoglycerides for swine and poultry applications. FRONTIERS IN ANIMAL SCIENCE 2022. [DOI: 10.3389/fanim.2022.1019320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The development of natural, broadly acting antimicrobial solutions to combat viral and bacterial pathogens is a high priority for the livestock industry. Herein, we cover the latest progress in utilizing lipid-based monoglycerides as feed additives to address some of the biggest challenges in animal agriculture. The current industry needs for effective antimicrobial strategies are introduced before discussing why medium-chain monoglycerides are a promising solution due to attractive molecular features and biological functions. We then critically analyze recent application examples in which case monoglycerides demonstrated superior activity to prevent feed transmission of viruses in swine and to mitigate bacterial infections in poultry along with gut microbiome modulation capabilities. Future innovation strategies are also suggested to expand the range of application possibilities and to enable new monoglyceride delivery options.
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12
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Takeuchi R, Ogihara K, Fujimoto J, Sato K, Mase N, Yoshimura K, Harada S, Narumi T. Design, synthesis, and bio-evaluation of novel triterpenoid derivatives as anti-HIV-1 compounds. Bioorg Med Chem Lett 2022; 69:128768. [PMID: 35513221 DOI: 10.1016/j.bmcl.2022.128768] [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: 02/23/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 11/02/2022]
Abstract
Two betulinic acid derivatives, RPR103611 (2) and IC9564 (3) were previously reported to be potent HIV-1 entry inhibitors. In this current study, a SAR study of the triterpenoid moiety of 2 and 3 has been performed and an oleanolic acid derivative (4) was identified as a novel HIV-1 entry inhibitor. In addition, the combination of 4 with several-type of HIV-1 neutralizing antibodies provided significant synergistic effects. The synthetic utility of the CC double bond in the C-ring of 4 was also demonstrated to develop the 12-keto-type oleanolic acid derivative (5) as a potent anti-HIV compound. This simple transformation led to a significantly increased anti-HIV activity and a reduced cytotoxicity of the compound.
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Affiliation(s)
- Reon Takeuchi
- Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan
| | - Kasumi Ogihara
- Course of Applied Chemistry and Biochemical Engineering, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan
| | - Junko Fujimoto
- Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University, Shizuoka, Japan
| | - Kohei Sato
- Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan; Course of Applied Chemistry and Biochemical Engineering, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan; Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University, Shizuoka, Japan
| | - Nobuyuki Mase
- Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan; Course of Applied Chemistry and Biochemical Engineering, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan; Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University, Shizuoka, Japan; Research Institute of Green Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan
| | - Kazuhisa Yoshimura
- Institute of Public Health, Bureau of Social Welfare and Public Health, Tokyo Metropolitan Government, 3-24-1 Hyakunin-cho, Shinjuku-ku, Tokyo, Japan; AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, Japan
| | - Shigeyoshi Harada
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, Japan.
| | - Tetsuo Narumi
- Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan; Course of Applied Chemistry and Biochemical Engineering, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan; Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University, Shizuoka, Japan; Research Institute of Green Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka, Japan.
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13
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Raghunath G, Chen YC, Marin M, Wu H, Melikyan GB. SERINC5-Mediated Restriction of HIV-1 Infectivity Correlates with Resistance to Cholesterol Extraction but Not with Lipid Order of Viral Membrane. Viruses 2022; 14:v14081636. [PMID: 35893701 PMCID: PMC9332783 DOI: 10.3390/v14081636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/19/2022] [Accepted: 07/23/2022] [Indexed: 12/13/2022] Open
Abstract
Serine incorporator 5 (SER5) is a protein that upon incorporation into virions inhibits HIV-1 infectivity by interfering with the ability of the Env glycoprotein to promote viral fusion. The mechanisms by which SER5 antagonizes HIV-1 fusion are not well understood. A recent study of SER5's structure revealed a lipid-binding pocket, suggesting the ability to sequester lipids. This finding, along with the well-documented modulation of HIV-1 infectivity by viral lipids, especially cholesterol, prompted our examination of SER5's effect on the general lipid order of the HIV-1 membrane. Pseudoviruses bearing the SER5-sensitive HXB2-Env and containing SER5 or SER2, a control protein that lacks antiviral activity, were analyzed using two distinct lipid-order probes. We show that SER5 incorporation does not noticeably affect the lipid order of pseudoviruses. Although viral cholesterol extraction reduces HIV-1 infectivity, SER5+ viruses are less sensitive to cholesterol extraction than the control samples. In contrast, the virus' sensitivity to cholesterol oxidation was not affected by SER5 incorporation. The hydrolytic release of sphingomyelin-sequestered cholesterol had a minimal impact on the apparent resistance to cholesterol extraction. Based on these results, we propose that a subpopulation of more stable Env glycoproteins responsible for the residual infectivity of SER5+ viruses is less sensitive to the cholesterol content of the viral membrane.
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Affiliation(s)
- Gokul Raghunath
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (Y.-C.C.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Yen-Cheng Chen
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (Y.-C.C.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Mariana Marin
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (Y.-C.C.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Hui Wu
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (Y.-C.C.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Gregory B. Melikyan
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA 30322, USA; (G.R.); (Y.-C.C.); (M.M.); (H.W.)
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
- Correspondence:
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14
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Rojas Chávez RA, Boyt D, Schwery N, Han C, Wu L, Haim H. Commonly Elicited Antibodies against the Base of the HIV-1 Env Trimer Guide the Population-Level Evolution of a Structure-Regulating Region in gp41. J Virol 2022; 96:e0040622. [PMID: 35658529 PMCID: PMC9278142 DOI: 10.1128/jvi.00406-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/11/2022] [Indexed: 01/28/2023] Open
Abstract
The antibody response against the HIV-1 envelope glycoproteins (Envs) guides evolution of this protein within each host. Whether antibodies with similar target specificities are elicited in different individuals and affect the population-level evolution of Env is poorly understood. To address this question, we analyzed properties of emerging variants in the gp41 fusion peptide-proximal region (FPPR) that exhibit distinct evolutionary patterns in HIV-1 clade B. For positions 534, 536, and 539 in the FPPR, alanine was the major emerging variant. However, 534A and 536A show a constant frequency in the population between 1979 and 2016, whereas 539A is gradually increasing. To understand the basis for these differences, we introduced alanine substitutions in the FPPR of primary HIV-1 strains and examined their functional and antigenic properties. Evolutionary patterns could not be explained by fusion competence or structural stability of the emerging variants. Instead, 534A and 536A exhibited modest but significant increases in sensitivity to antibodies against the membrane-proximal external region (MPER) and gp120-gp41 interface. These Envs were also more sensitive to poorly neutralizing sera from HIV-1-infected individuals than the clade ancestral form or 539A variant. Competition binding assays confirmed for all sera tested the presence of antibodies against the base of the Env trimer that compete with monoclonal antibodies targeting the MPER and gp120-gp41 interface. Our findings suggest that weakly neutralizing antibodies against the trimer base are commonly elicited; they do not exert catastrophic population size reduction effects on emerging variants but, instead, determine their set point frequencies in the population and historical patterns of change. IMPORTANCE Infection by HIV-1 elicits formation of antibodies that target the viral Env proteins and can inactivate the virus. The specific targets of these antibodies vary among infected individuals. It is unclear whether some target specificities are shared among the antibody responses of different individuals. We observed that antibodies against the base of the Env protein are commonly elicited during infection. The selective pressure applied by such antibodies is weak. As a result, they do not completely eliminate the sensitive forms of the virus from the population, but maintain their frequency at a low level that has not increased since the beginning of the AIDS pandemic. Interestingly, the changes in Env do not occur at the sites targeted by the antibodies, but at a distinct region of Env, the fusion peptide-proximal region, which regulates their exposure.
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Affiliation(s)
- Roberth Anthony Rojas Chávez
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Devlin Boyt
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Nathan Schwery
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Changze Han
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Li Wu
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
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15
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Han M, Cantaloube-Ferrieu V, Xie M, Armani-Tourret M, Woottum M, Pagès JC, Colin P, Lagane B, Benichou S. HIV-1 cell-to-cell spread overcomes the virus entry block of non-macrophage-tropic strains in macrophages. PLoS Pathog 2022; 18:e1010335. [PMID: 35622876 PMCID: PMC9182568 DOI: 10.1371/journal.ppat.1010335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/09/2022] [Accepted: 05/09/2022] [Indexed: 11/19/2022] Open
Abstract
Macrophages (MΦ) are increasingly recognized as HIV-1 target cells involved in the pathogenesis and persistence of infection. Paradoxically, in vitro infection assays suggest that virus isolates are mostly T-cell-tropic and rarely MΦ-tropic. The latter are assumed to emerge under CD4+ T-cell paucity in tissues such as the brain or at late stage when the CD4 T-cell count declines. However, assays to qualify HIV-1 tropism use cell-free viral particles and may not fully reflect the conditions of in vivo MΦ infection through cell-to-cell viral transfer. Here, we investigated the capacity of viruses expressing primary envelope glycoproteins (Envs) with CCR5 and/or CXCR4 usage from different stages of infection, including transmitted/founder Envs, to infect MΦ by a cell-free mode and through cell-to-cell transfer from infected CD4+ T cells. The results show that most viruses were unable to enter MΦ as cell-free particles, in agreement with the current view that non-M-tropic viruses inefficiently use CD4 and/or CCR5 or CXCR4 entry receptors on MΦ. In contrast, all viruses could be effectively cell-to-cell transferred to MΦ from infected CD4+ T cells. We further showed that viral transfer proceeded through Env-dependent cell-cell fusion of infected T cells with MΦ targets, leading to the formation of productively infected multinucleated giant cells. Compared to cell-free infection, infected T-cell/MΦ contacts showed enhanced interactions of R5 M- and non-M-tropic Envs with CD4 and CCR5, resulting in a reduced dependence on receptor expression levels on MΦ for viral entry. Altogether, our results show that virus cell-to-cell transfer overcomes the entry block of isolates initially defined as non-macrophage-tropic, indicating that HIV-1 has a more prevalent tropism for MΦ than initially suggested. This sheds light into the role of this route of virus cell-to-cell transfer to MΦ in CD4+ T cell rich tissues for HIV-1 transmission, dissemination and formation of tissue viral reservoirs.
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Affiliation(s)
- Mingyu Han
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | | | - Maorong Xie
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | | | - Marie Woottum
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | - Jean-Christophe Pagès
- Institut RESTORE, Université de Toulouse, CNRS U-5070, EFS, ENVT, Inserm U1301, Toulouse, France
| | - Philippe Colin
- Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
| | - Bernard Lagane
- Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
- * E-mail: (BL); (SB)
| | - Serge Benichou
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
- * E-mail: (BL); (SB)
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16
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Cale EM, Driscoll JI, Lee M, Gorman J, Zhou T, Lu M, Geng H, Lai YT, Chuang GY, Doria-Rose NA, Mothes W, Kwong PD, Mascola JR. Antigenic analysis of the HIV-1 envelope trimer implies small differences between structural states 1 and 2. J Biol Chem 2022; 298:101819. [PMID: 35283191 PMCID: PMC9006658 DOI: 10.1016/j.jbc.2022.101819] [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: 11/03/2021] [Revised: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 11/20/2022] Open
Abstract
The conformationally dynamic HIV-1 envelope trimer (Env) is the target of broadly neutralizing antibodies (bnAbs) that block viral entry. Single-molecule Förster resonance energy transfer (smFRET) has revealed that HIV-1 Env exists in at least three conformational states on the virion. Prior to complete host-receptor engagement (State 3), Env resides most prevalently in the smFRET-defined State 1, which is preferentially recognized by most bnAbs that are elicited by natural infection. smFRET has also revealed that soluble trimers containing prefusion-stabilizing disulfide and isoleucine-to-proline substitutions reside primarily in State 2, which is a required intermediate between States 1 and 3. While high-resolution Env structures have been determined for States 2 and 3, the structure of these trimers in State 1 is unknown. To provide insight into the State 1 structure, here we characterized antigenic differences between smFRET-defined states and then correlated these differences with known structural differences between States 2 and 3. We found that cell surface-expressed Env was enriched in each state using state-enriching antibody fragments or small-molecule virus entry inhibitors and then assessed binding to HIV-1 bnAbs preferentially binding different states. We observed small but consistent differences in binding between Env enriched in States 1 and 2, and a more than 10-fold difference in binding to Env enriched in these states versus Env enriched in State 3. We conclude that structural differences between HIV-1 Env States 1 and 3 are likely more than 10-fold greater than those between States 1 and 2, providing important insight into State 1.
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Affiliation(s)
- Evan M Cale
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Jefferson I Driscoll
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Myungjin Lee
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Maolin Lu
- Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Cellular and Molecular Biology, University of Texas Health Science Center, Tyler, Texas, USA
| | - Hui Geng
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Yen-Ting Lai
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
| | - John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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17
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Global Increases in Human Immunodeficiency Virus Neutralization Sensitivity Due to Alterations in the Membrane-Proximal External Region of the Envelope Glycoprotein Can Be Minimized by Distant State 1-Stabilizing Changes. J Virol 2022; 96:e0187821. [PMID: 35289647 DOI: 10.1128/jvi.01878-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Binding to the receptor, CD4, drives the pretriggered, "closed" (State-1) conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ([gp120/gp41]3) into more "open" conformations. HIV-1 Env on the viral membrane is maintained in a State-1 conformation that resists binding and neutralization by commonly elicited antibodies. Premature triggering of Env before the virus engages a target cell typically leads to increased susceptibility to spontaneous inactivation or ligand-induced neutralization. Here, we showed that single amino acid substitutions in the gp41 membrane-proximal external region (MPER) of a primary HIV-1 strain resulted in viral phenotypes indicative of premature triggering of Env to downstream conformations. Specifically, the MPER changes reduced viral infectivity and globally increased virus sensitivity to poorly neutralizing antibodies, soluble CD4, a CD4-mimetic compound, and exposure to cold. In contrast, the MPER mutants exhibited decreased sensitivity to the State 1-preferring inhibitor, BMS-806, and to the PGT151 broadly neutralizing antibody. Depletion of cholesterol from virus particles did not produce the same State 1-destabilizing phenotypes as MPER alterations. Notably, State 1-stabilizing changes in Env distant from the MPER could minimize the phenotypic effects of MPER alteration but did not affect virus sensitivity to cholesterol depletion. Thus, membrane-proximal gp41 elements contribute to the maintenance of the pretriggered Env conformation. The conformationally disruptive effects of MPER changes can be minimized by distant State 1-stabilizing Env modifications, a strategy that may be useful in preserving the native pretriggered state of Env. IMPORTANCE The pretriggered shape of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) is a major target for antibodies that can neutralize many strains of the virus. An effective HIV-1 vaccine may need to raise these types of antibodies, but this goal has proven difficult. One reason is that the pretriggered shape of Env is unstable and dependent on interactions near the viral membrane. Here, we showed that the membrane-proximal external region (MPER) of Env plays an important role in maintaining Env in a pretriggered shape. Alterations in the MPER resulted in global changes in Env conformation that disrupted its pretriggered shape. We also found that these disruptive effects of MPER changes could be minimized by distant Env modifications that stabilized the pretriggered shape. These modifications may be useful for preserving the native shape of Env for structural and vaccine studies.
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18
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AbuRuz S, Al-Azayzih A, ZainAlAbdin S, Beiram R, Al Hajjar M. Clinical characteristics and risk factors for mortality among COVID-19 hospitalized patients in UAE: Does ethnic origin have an impact. PLoS One 2022; 17:e0264547. [PMID: 35235580 PMCID: PMC8890645 DOI: 10.1371/journal.pone.0264547] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 02/12/2022] [Indexed: 01/08/2023] Open
Abstract
Background The relationship between COVID-19 patient’s clinical characteristics and disease manifestation remains incompletely understood. The impact of ethnicity on mortality of patients with COVID-19 infection is poorly addressed in the literature. Emerging evidence suggests that many risk factors are related to symptoms severity and mortality risk, emphasizing the necessity of fulfilling this knowledge gap that may help reducing mortality from COVID-19 infections through tackling the risk factors. Aims To explore epidemiological and demographic characteristics of hospitalized COVID-19 patients from different ethnic origins living in the UAE, compare them to findings reported across the globe and determine the impact of these characteristics and ethnicity on mortality during hospitalization. Methods A single center, retrospective chart review study of hospitalized COVID-19 patients was conducted in a large COVID-19 referral hospital in UAE. The following outcomes were assessed: patients’ clinical characteristics, disease symptoms and severity, and association of ethnicity and other risk factors on 30-day in hospital mortality. Results A total of 3296 patients were recruited in this study with an average age of 44.3±13.4 years old. Preliminary data analysis indicated that 78.3% (n = 2582) of cases were considered mild. Average duration of hospital stay was 6.0±7.3 days and 4.3% (n = 143) were admitted to ICU. The most frequently reported symptoms were cough (32.6%, n = 1075) and fever (22.2%, n = 731). The 30-day mortality rate during hospitalization was 2.7% (n = 90). Many risk factors were associated with mortality during hospitalization including: age, respiratory rate (RR), creatinine, and C-reactive protein, oxygen saturation (SaO2), hemoglobin, hematocrit, ferritin, creatinine, C-reactive protein, anemia, COPD, Chronic kidney disease, dyslipidemia, Vitamin-D Deficiency, and ethnic origin (p <0.05). Multiple logistic regression analysis showed that higher mortality rates during hospitalization was associated with anemia, chronic obstructive pulmonary disease (COPD), chronic kidney disease, and Middle Eastern origin (p<0.05). Conclusion The results indicated that most COVID-19 cases were mild and morality rate was low compared to worldwide reported mortality. Mortality rate during hospitalization was higher in patients from Middle East origin with preexisting comorbidities especially anemia, COPD, and chronic kidney disease. Due to the relatively small number of mortality cases, other identified risk factors from univariate analysis such as age, respiratory rate, and Vitamin-D (VitD) deficiency should also be taken into consideration. It is crucial to stratify patients on admission based on these risk factors to help decide intensity and type of treatment which, possibly, will reduce the risk of death.
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Affiliation(s)
- Salah AbuRuz
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, The United Arab Emirates University, Al Ain, United Arab Emirates
- Department of Clinical Pharmacy, Faculty of Pharmacy, The University of Jordan, Amman, Jordan
- * E-mail:
| | - Ahmad Al-Azayzih
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Sham ZainAlAbdin
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, The United Arab Emirates University, Al Ain, United Arab Emirates
| | - Rami Beiram
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, The United Arab Emirates University, Al Ain, United Arab Emirates
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19
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Van Ert HA, Bohan DW, Rogers K, Fili M, Rojas Chávez RA, Qing E, Han C, Dempewolf S, Hu G, Schwery N, Sevcik K, Ruggio N, Boyt D, Pentella MA, Gallagher T, Jackson JB, Merrill AE, Knudson CM, Brown GD, Maury W, Haim H. Limited Variation between SARS-CoV-2-Infected Individuals in Domain Specificity and Relative Potency of the Antibody Response against the Spike Glycoprotein. Microbiol Spectr 2022; 10:e0267621. [PMID: 35080430 PMCID: PMC8791189 DOI: 10.1128/spectrum.02676-21] [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: 12/21/2021] [Accepted: 12/28/2021] [Indexed: 11/25/2022] Open
Abstract
The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is arranged as a trimer on the virus surface, composed of three S1 and three S2 subunits. Infected and vaccinated individuals generate antibodies against spike, which can neutralize the virus. Most antibodies target the receptor-binding domain (RBD) and N-terminal domain (NTD) of S1; however, antibodies against other regions of spike have also been isolated. The interhost variability in domain specificity and relative neutralization efficacy of the antibodies is still poorly characterized. To this end, we tested serum and plasma samples collected from 85 coronavirus disease 2019 (COVID-19) convalescent subjects. Samples were analyzed using seven immunoassays that employ different domains, subunits, and oligomeric forms of spike to capture the antibodies. Samples were also tested for their neutralization of pseudovirus containing SARS-CoV-2 spike and of replication-competent SARS-CoV-2. While the total amount of anti-spike antibodies produced varied among convalescent subjects, we observed an unexpectedly fixed ratio of RBD- to NTD-targeting antibodies. The relative potency of the response (defined as the measured neutralization efficacy relative to the total level of spike-targeting antibodies) also exhibited limited variation between subjects and was not associated with the overall amount of antispike antibodies produced. These studies suggest that host-to-host variation in the polyclonal response elicited against SARS-CoV-2 spike in early pandemic subjects is primarily limited to the quantity of antibodies generated rather than their domain specificity or relative neutralization potency. IMPORTANCE Infection by SARS-CoV-2 elicits antibodies against various domains of the spike protein, including the RBD and NTD of subunit S1 and against subunit S2. The antibody responses of different infected individuals exhibit different efficacies to inactivate (neutralize) the virus. Here, we show that the observed variation in the neutralizing activity of the antibody responses in COVID-19 convalescent subjects is caused by differences in the amounts of antibodies rather than their recognition properties or the potency of their antiviral activity. These findings suggest that COVID-19 vaccine strategies that focus on enhancing the overall level of the antibodies will likely elicit a more uniformly efficacious protective response.
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Affiliation(s)
- Hanora A. Van Ert
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Dana W. Bohan
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Kai Rogers
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Mohammad Fili
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, Ames, Iowa, United States
| | - Roberth A. Rojas Chávez
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Enya Qing
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, United States
| | - Changze Han
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Spencer Dempewolf
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Guiping Hu
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, Ames, Iowa, United States
| | - Nathan Schwery
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Kristina Sevcik
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Natalie Ruggio
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Devlin Boyt
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Michael A. Pentella
- State Hygienic Laboratory, The University of Iowa, Iowa City, Iowa, United States
| | - Tom Gallagher
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, United States
| | - J. Brooks Jackson
- Department of Pathology, University of Iowa Hospitals & Clinics, Iowa City, Iowa, United States
| | - Anna E. Merrill
- Department of Pathology, University of Iowa Hospitals & Clinics, Iowa City, Iowa, United States
| | - C. Michael Knudson
- Department of Pathology, University of Iowa Hospitals & Clinics, Iowa City, Iowa, United States
| | - Grant D. Brown
- Department of Biostatistics, School of Public Health, The University of Iowa, Iowa City, Iowa, United States
| | - Wendy Maury
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
| | - Hillel Haim
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, United States
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20
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Zhang S, Wang K, Wang WL, Nguyen HT, Chen S, Lu M, Go EP, Ding H, Steinbock RT, Desaire H, Kappes JC, Sodroski J, Mao Y. Asymmetric Structures and Conformational Plasticity of the Uncleaved Full-Length Human Immunodeficiency Virus Envelope Glycoprotein Trimer. J Virol 2021; 95:e0052921. [PMID: 34549974 PMCID: PMC8610584 DOI: 10.1128/jvi.00529-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 09/06/2021] [Indexed: 11/20/2022] Open
Abstract
The functional human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer [(gp120/gp41)3] is produced by cleavage of a conformationally flexible gp160 precursor. gp160 cleavage or the binding of BMS-806, an entry inhibitor, stabilizes the pretriggered, "closed" (state 1) conformation recognized by rarely elicited broadly neutralizing antibodies. Poorly neutralizing antibodies (pNAbs) elicited at high titers during natural infection recognize more "open" Env conformations (states 2 and 3) induced by binding the receptor, CD4. We found that BMS-806 treatment and cross-linking decreased the exposure of pNAb epitopes on cell surface gp160; however, after detergent solubilization, cross-linked and BMS-806-treated gp160 sampled non-state-1 conformations that could be recognized by pNAbs. Cryo-electron microscopy of the purified BMS-806-bound gp160 revealed two hitherto unknown asymmetric trimer conformations, providing insights into the allosteric coupling between trimer opening and structural variation in the gp41 HR1N region. The individual protomer structures in the asymmetric gp160 trimers resemble those of other genetically modified or antibody-bound cleaved HIV-1 Env trimers, which have been suggested to assume state-2-like conformations. Asymmetry of the uncleaved Env potentially exposes surfaces of the trimer to pNAbs. To evaluate the effect of stabilizing a state-1-like conformation of the membrane Env precursor, we treated cells expressing wild-type HIV-1 Env with BMS-806. BMS-806 treatment decreased both gp160 cleavage and the addition of complex glycans, implying that gp160 conformational flexibility contributes to the efficiency of these processes. Selective pressure to maintain flexibility in the precursor of functional Env allows the uncleaved Env to sample asymmetric conformations that potentially skew host antibody responses toward pNAbs. IMPORTANCE The envelope glycoprotein (Env) trimers on the surface of human immunodeficiency virus (HIV-1) mediate the entry of the virus into host cells and serve as targets for neutralizing antibodies. The functional Env trimer is produced by cleavage of the gp160 precursor in the infected cell. We found that the HIV-1 Env precursor is highly plastic, allowing it to assume different asymmetric shapes. This conformational plasticity is potentially important for Env cleavage and proper modification by sugars. Having a flexible, asymmetric Env precursor that can misdirect host antibody responses without compromising virus infectivity would be an advantage for a persistent virus like HIV-1.
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Affiliation(s)
- Shijian Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Kunyu Wang
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
| | - Wei Li Wang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
- Intel Parallel Computing Center for Structural Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Hanh T. Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shuobing Chen
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Eden P. Go
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
| | - Robert T. Steinbock
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Heather Desaire
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
- Intel Parallel Computing Center for Structural Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
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21
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Bohan D, Van Ert H, Ruggio N, Rogers KJ, Badreddine M, Aguilar Briseño JA, Elliff JM, Rojas Chavez RA, Gao B, Stokowy T, Christakou E, Kursula P, Micklem D, Gausdal G, Haim H, Minna J, Lorens JB, Maury W. Phosphatidylserine receptors enhance SARS-CoV-2 infection. PLoS Pathog 2021; 17:e1009743. [PMID: 34797899 PMCID: PMC8641883 DOI: 10.1371/journal.ppat.1009743] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 12/03/2021] [Accepted: 10/19/2021] [Indexed: 01/16/2023] Open
Abstract
Phosphatidylserine (PS) receptors enhance infection of many enveloped viruses through virion-associated PS binding that is termed apoptotic mimicry. Here we show that this broadly shared uptake mechanism is utilized by SARS-CoV-2 in cells that express low surface levels of ACE2. Expression of members of the TIM (TIM-1 and TIM-4) and TAM (AXL) families of PS receptors enhance SARS-CoV-2 binding to cells, facilitate internalization of fluorescently-labeled virions and increase ACE2-dependent infection of SARS-CoV-2; however, PS receptors alone did not mediate infection. We were unable to detect direct interactions of the PS receptor AXL with purified SARS-CoV-2 spike, contrary to a previous report. Instead, our studies indicate that the PS receptors interact with PS on the surface of SARS-CoV-2 virions. In support of this, we demonstrate that: 1) significant quantities of PS are located on the outer leaflet of SARS-CoV-2 virions, 2) PS liposomes, but not phosphatidylcholine liposomes, reduced entry of VSV/Spike pseudovirions and 3) an established mutant of TIM-1 which does not bind to PS is unable to facilitate entry of SARS-CoV-2. As AXL is an abundant PS receptor on a number of airway lines, we evaluated small molecule inhibitors of AXL signaling such as bemcentinib for their ability to inhibit SARS-CoV-2 infection. Bemcentinib robustly inhibited virus infection of Vero E6 cells as well as multiple human lung cell lines that expressed AXL. This inhibition correlated well with inhibitors that block endosomal acidification and cathepsin activity, consistent with AXL-mediated uptake of SARS-CoV-2 into the endosomal compartment. We extended our observations to the related betacoronavirus mouse hepatitis virus (MHV), showing that inhibition or ablation of AXL reduces MHV infection of murine cells. In total, our findings provide evidence that PS receptors facilitate infection of the pandemic coronavirus SARS-CoV-2 and suggest that inhibition of the PS receptor AXL has therapeutic potential against SARS-CoV-2. Phosphatidylserine (PS) receptors bind PS and mediate uptake of apoptotic bodies. Many enveloped viruses utilize this PS/PS receptor mechanism to adhere to and internalize into the endosomal compartment of cells. For viruses that have a mechanism(s) of endosomal escape, apoptotic mimicry is a productive route of virus entry. This clever use of this uptake mechanism by enveloped viruses is termed apoptotic mimicry. We evaluated if PS receptors serve as cell surface receptors for SARS-CoV-2 and found that the PS receptors, AXL, TIM-1 and TIM-4, facilitated virus infection when the SARS-CoV-2 cognate receptor, ACE2, was present. Consistent with the established mechanism of PS receptor utilization by other viruses, PS liposomes competed with SARS-CoV-2 for binding and entry. PS is readily detectable on the surface of SARS-CoV-2 virions, and contrary to prior reports we were unable to identify any interaction between AXL and SARS-CoV-2 spike. Pharmacological inhibition of AXL activity and knockout of AXL expression suggest it is the preferred PS receptor during SARS-CoV-2 entry. We propose that AXL is an under-appreciated but potentially important host factor facilitating SARS-CoV-2 entry.
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Affiliation(s)
- Dana Bohan
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Hanora Van Ert
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Natalie Ruggio
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Kai J. Rogers
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Mohammad Badreddine
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - José A. Aguilar Briseño
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Jonah M. Elliff
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | | | - Boning Gao
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Tomasz Stokowy
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Eleni Christakou
- Department of Biomedicine, University of Bergen, Bergen, Norway
- BerGenBio ASA, Bergen, Norway
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Biocenter Oulu & Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | | | - Hillel Haim
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - John Minna
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - James B. Lorens
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Wendy Maury
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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22
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Prévost J, Medjahed H, Vézina D, Chen HC, Hahn BH, Smith AB, Finzi A. HIV-1 Envelope Glycoproteins Proteolytic Cleavage Protects Infected Cells from ADCC Mediated by Plasma from Infected Individuals. Viruses 2021; 13:2236. [PMID: 34835042 PMCID: PMC8625184 DOI: 10.3390/v13112236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 12/28/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) is synthesized in the endoplasmic reticulum as a trimeric gp160 precursor, which requires proteolytic cleavage by a cellular furin protease to mediate virus-cell fusion. Env is conformationally flexible but controls its transition from the unbound "closed" conformation (State 1) to downstream CD4-bound conformations (States 2/3), which are required for fusion. In particular, HIV-1 has evolved several mechanisms that reduce the premature "opening" of Env which exposes highly conserved epitopes recognized by non-neutralizing antibodies (nnAbs) capable of mediating antibody-dependent cellular cytotoxicity (ADCC). Env cleavage decreases its conformational transitions favoring the adoption of the "closed" conformation. Here we altered the gp160 furin cleavage site to impair Env cleavage and to examine its impact on ADCC responses mediated by plasma from HIV-1-infected individuals. We found that infected primary CD4+ T cells expressing uncleaved, but not wildtype, Env are efficiently recognized by nnAbs and become highly susceptible to ADCC responses mediated by plasma from HIV-1-infected individuals. Thus, HIV-1 limits the exposure of uncleaved Env at the surface of HIV-1-infected cells at least in part to escape ADCC responses.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Halima Medjahed
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
| | - Dani Vézina
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
| | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (H.-C.C.); (A.B.S.III)
| | - Beatrice H. Hahn
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA;
| | - Amos B. Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (H.-C.C.); (A.B.S.III)
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
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23
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Anand SP, Prévost J, Descôteaux-Dinelle J, Richard J, Nguyen DN, Medjahed H, Chen HC, Smith AB, Pazgier M, Finzi A. HIV-1 Envelope Glycoprotein Cell Surface Localization Is Associated with Antibody-Induced Internalization. Viruses 2021; 13:1953. [PMID: 34696383 PMCID: PMC8539245 DOI: 10.3390/v13101953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/15/2021] [Accepted: 09/27/2021] [Indexed: 12/29/2022] Open
Abstract
To minimize immune responses against infected cells, HIV-1 has evolved different mechanisms to limit the surface expression of its envelope glycoproteins (Env). Recent observations suggest that the binding of certain broadly neutralizing antibodies (bNAbs) targeting the 'closed' conformation of Env induces its internalization. On the other hand, non-neutralizing antibodies (nNAbs) that preferentially target Env in its 'open' conformation, remain bound to Env on the cell surface for longer periods of time. In this study, we attempt to better understand the underlying mechanisms behind the differential rates of antibody-mediated Env internalization. We demonstrate that 'forcing' open Env using CD4 mimetics allows for nNAb binding and results in similar rates of Env internalization as those observed upon the bNAb binding. Moreover, we can identify distinct populations of Env that are differentially targeted by Abs that mediate faster rates of internalization, suggesting that the mechanism of antibody-induced Env internalization partially depends on the localization of Env on the cell surface.
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Affiliation(s)
- Sai Priya Anand
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (S.P.A.); (J.P.); (J.D.-D.); (J.R.); (H.M.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (S.P.A.); (J.P.); (J.D.-D.); (J.R.); (H.M.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Jade Descôteaux-Dinelle
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (S.P.A.); (J.P.); (J.D.-D.); (J.R.); (H.M.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (S.P.A.); (J.P.); (J.D.-D.); (J.R.); (H.M.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Dung N. Nguyen
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4712, USA; (D.N.N.); (M.P.)
| | - Halima Medjahed
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (S.P.A.); (J.P.); (J.D.-D.); (J.R.); (H.M.)
| | - Hung-Ching Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA; (H.-C.C.); (A.B.S.III)
| | - Amos B. Smith
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA; (H.-C.C.); (A.B.S.III)
| | - Marzena Pazgier
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4712, USA; (D.N.N.); (M.P.)
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (S.P.A.); (J.P.); (J.D.-D.); (J.R.); (H.M.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
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24
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Bohan D, Ert HV, Ruggio N, Rogers KJ, Badreddine M, Aguilar Briseño JA, Rojas Chavez RA, Gao B, Stokowy T, Christakou E, Micklem D, Gausdal G, Haim H, Minna J, Lorens JB, Maury W. Phosphatidylserine Receptors Enhance SARS-CoV-2 Infection: AXL as a Therapeutic Target for COVID-19. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021. [PMID: 34159331 PMCID: PMC8219095 DOI: 10.1101/2021.06.15.448419] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Phosphatidylserine (PS) receptors are PS binding proteins that mediate uptake of apoptotic bodies. Many enveloped viruses utilize this PS/PS receptor mechanism to adhere to and internalize into the endosomal compartment of cells and this is termed apoptotic mimicry. For viruses that have a mechanism(s) of endosomal escape, apoptotic mimicry is a productive route of virus entry. We evaluated if PS receptors serve as cell surface receptors for SARS-CoV-2 and found that the PS receptors, AXL, TIM-1 and TIM-4, facilitated virus infection when low concentrations of the SARS-CoV-2 cognate receptor, ACE2, was present. Consistent with the established mechanism of PS receptor utilization by other viruses, PS liposomes competed with SARS-CoV-2 for binding and entry. We demonstrated that this PS receptor enhances SARS-CoV-2 binding to and infection of an array of human lung cell lines and is an under-appreciated but potentially important host factor facilitating SARS-CoV-2 entry.
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Affiliation(s)
- Dana Bohan
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
| | - Hanora Van Ert
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
| | - Natalie Ruggio
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
| | - Kai J Rogers
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
| | - Mohammad Badreddine
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
| | | | | | - Boning Gao
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX
| | - Tomasz Stokowy
- Department of Biomedicine, University of Bergen, Bergen Norway
| | - Eleni Christakou
- Department of Biomedicine, University of Bergen, Bergen Norway.,BerGenBio ASA, Bergen, Norway
| | | | | | - Hillel Haim
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
| | - John Minna
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX
| | - James B Lorens
- Department of Biomedicine, University of Bergen, Bergen Norway
| | - Wendy Maury
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA
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25
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Marziali F, Cimarelli A. Membrane Interference Against HIV-1 by Intrinsic Antiviral Factors: The Case of IFITMs. Cells 2021; 10:cells10051171. [PMID: 34065027 PMCID: PMC8151167 DOI: 10.3390/cells10051171] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/06/2021] [Accepted: 05/10/2021] [Indexed: 12/13/2022] Open
Abstract
HIV-1 is a complex retrovirus that is adapted to replicate in cells of the immune system. To do so, HIV-1, like other viruses, developed strategies to use several cellular processes to its advantage, but had also to come to terms with an arsenal of cellular innate defense proteins, or antiviral factors, that target more or less efficiently, virtually every step of the virus replicative cycle. Among antiviral restriction factors, the family of interferon-induced transmembrane proteins (IFITMs) has emerged as a crucial component of cellular innate defenses for their ability to interfere with both early and late phases of viral replication by inhibiting cellular and viral membranes fusion. Here, we review the enormous advances made since the discovery of IFITMs as interferon-regulated genes more than thirty years ago, with a particular focus on HIV-1 and on the elements that modulate its susceptibility or resistance towards members of this family. Given the recent advances of the field in the elucidation of the mechanism of IFITM inhibition and on the mechanism(s) of viral resistance, we expect that future years will bring novel insights into the definition of the multiple facets of IFITMs and on their possible use for novel therapeutical approaches.
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Affiliation(s)
- Federico Marziali
- Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, Inserm U1111, CNRS, UMR5308, ENS de Lyon, Université Claude Bernard Lyon 1, 46 Allée d'Italie, 69007 Lyon, France
| | - Andrea Cimarelli
- Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, Inserm U1111, CNRS, UMR5308, ENS de Lyon, Université Claude Bernard Lyon 1, 46 Allée d'Italie, 69007 Lyon, France
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26
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Kočar E, Režen T, Rozman D. Cholesterol, lipoproteins, and COVID-19: Basic concepts and clinical applications. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158849. [PMID: 33157278 PMCID: PMC7610134 DOI: 10.1016/j.bbalip.2020.158849] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/09/2020] [Accepted: 10/25/2020] [Indexed: 12/19/2022]
Abstract
Cholesterol is being recognized as a molecule involved in regulating the entry of the SARS-CoV-2 virus into the host cell. However, the data about the possible role of cholesterol carrying lipoproteins and their receptors in relation to infection are scarce and the connection of lipid-associated pathologies with COVID-19 disease is in its infancy. Herein we provide an overview of lipids and lipid metabolism in relation to COVID-19, with special attention on different forms of cholesterol. Cholesterol enriched lipid rafts represent a platform for viruses to enter the host cell by endocytosis. Generally, higher membrane cholesterol coincides with higher efficiency of COVID-19 entry. Inversely, patients with COVID-19 show lowered levels of blood cholesterol, high-density lipoproteins (HDL) and low-density lipoproteins. The modulated efficiency of viral entry can be explained by availability of SR-B1 receptor. HDL seems to have a variety of roles, from being itself a scavenger for viruses, an immune modulator and mediator of viral entry. Due to inverse roles of membrane cholesterol and lipoprotein cholesterol in COVID-19 infected patients, treatment of these patients with cholesterol lowering statins needs more attention. In conclusion, cholesterol and lipoproteins are potential markers for monitoring the viral infection status, while the lipid metabolic pathways and the composition of membranes could be targeted to selectively inhibit the life cycle of the virus as a basis for antiviral therapy.
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Affiliation(s)
- Eva Kočar
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
| | - Tadeja Režen
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
| | - Damjana Rozman
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
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27
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Nieto‐Garai JA, Arboleya A, Otaegi S, Chojnacki J, Casas J, Fabriàs G, Contreras F, Kräusslich H, Lorizate M. Cholesterol in the Viral Membrane is a Molecular Switch Governing HIV-1 Env Clustering. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2003468. [PMID: 33552873 PMCID: PMC7856888 DOI: 10.1002/advs.202003468] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/13/2020] [Indexed: 05/07/2023]
Abstract
HIV-1 entry requires the redistribution of envelope glycoproteins (Env) into a cluster and the presence of cholesterol (chol) in the viral membrane. However, the molecular mechanisms underlying the specific role of chol in infectivity and the driving force behind Env clustering remain unknown. Here, gp41 is demonstrated to directly interact with chol in the viral membrane via residues 751-854 in the cytoplasmic tail (CT751-854). Super-resolution stimulated emission depletion (STED) nanoscopy analysis of Env distribution further demonstrates that both truncation of gp41 CT751-854 and depletion of chol leads to dispersion of Env clusters in the viral membrane and inhibition of virus entry. This work reveals a direct interaction of gp41 CT with chol and indicates that this interaction is an important orchestrator of Env clustering.
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Affiliation(s)
- Jon Ander Nieto‐Garai
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB)Barrio Sarriena s/nLeioaE‐48940Spain
| | - Aroa Arboleya
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB)Barrio Sarriena s/nLeioaE‐48940Spain
| | - Sara Otaegi
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Department of Biochemistry and Molecular BiologyFaculty of Science and TechnologyUniversity of the Basque CountryLeioaE‐48940Spain
| | | | - Josefina Casas
- Research Unit on BioActive Molecules. Department of Biological ChemistryInstitute for Advanced Chemistry of Catalonia (IQAC‐CSIC)BarcelonaCatalonia08034Spain
- Liver and Digestive Diseases Networking Biomedical Research Center (CIBEREHD) ISCIIMadrid28029Spain
| | - Gemma Fabriàs
- Research Unit on BioActive Molecules. Department of Biological ChemistryInstitute for Advanced Chemistry of Catalonia (IQAC‐CSIC)BarcelonaCatalonia08034Spain
- Liver and Digestive Diseases Networking Biomedical Research Center (CIBEREHD) ISCIIMadrid28029Spain
| | - F‐Xabier Contreras
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Department of Biochemistry and Molecular BiologyFaculty of Science and TechnologyUniversity of the Basque CountryLeioaE‐48940Spain
- IkerbasqueBasque Foundation for ScienceBilbao48013Spain
| | - Hans‐Georg Kräusslich
- Department of Infectious DiseasesVirologyUniversitätsklinikum HeidelbergHeidelberg69120Germany
| | - Maier Lorizate
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Department of Biochemistry and Molecular BiologyFaculty of Science and TechnologyUniversity of the Basque CountryLeioaE‐48940Spain
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28
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Barklis E, Alfadhli A, Kyle JE, Bramer LM, Bloodsworth KJ, Barklis RL, Leier HC, Petty RM, Zelnik ID, Metz TO, Futerman AH, Tafesse FG. Ceramide synthase 2 deletion decreases the infectivity of HIV-1. J Biol Chem 2021; 296:100340. [PMID: 33515546 PMCID: PMC7949126 DOI: 10.1016/j.jbc.2021.100340] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/01/2023] Open
Abstract
The lipid composition of HIV-1 virions is enriched in sphingomyelin (SM), but the roles that SM or other sphingolipids (SLs) might play in the HIV-1 replication pathway have not been elucidated. In human cells, SL levels are regulated by ceramide synthase (CerS) enzymes that produce ceramides, which can be converted to SMs, hexosylceramides, and other SLs. In many cell types, CerS2, which catalyzes the synthesis of very long chain ceramides, is the major CerS. We have examined how CerS2 deficiency affects the assembly and infectivity of HIV-1. As expected, we observed that very long chain ceramide, hexosylceramide, and SM were reduced in CerS2 knockout cells. CerS2 deficiency did not affect HIV-1 assembly or the incorporation of the HIV-1 envelope (Env) protein into virus particles, but it reduced the infectivites of viruses produced in the CerS2-deficient cells. The reduced viral infection levels were dependent on HIV-1 Env, since HIV-1 particles that were pseudotyped with the vesicular stomatitis virus glycoprotein did not exhibit reductions in infectivity. Moreover, cell-cell fusion assays demonstrated that the functional defect of HIV-1 Env in CerS2-deficient cells was independent of other viral proteins. Overall, our results indicate that the altered lipid composition of CerS2-deficient cells specifically inhibit the HIV-1 Env receptor binding and/or fusion processes.
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Affiliation(s)
- Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA.
| | - Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Jennifer E Kyle
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, Washington, USA
| | - Lisa M Bramer
- Computing and Analytics Division, National Security Directorate PNNL, Richland, Washington, USA
| | - Kent J Bloodsworth
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, Washington, USA
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Hans C Leier
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - R Max Petty
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Iris D Zelnik
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Thomas O Metz
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, Washington, USA
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Fikadu G Tafesse
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA.
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29
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Bruxelle JF, Trattnig N, Mureithi MW, Landais E, Pantophlet R. HIV-1 Entry and Prospects for Protecting against Infection. Microorganisms 2021; 9:microorganisms9020228. [PMID: 33499233 PMCID: PMC7911371 DOI: 10.3390/microorganisms9020228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022] Open
Abstract
Human Immunodeficiency Virus type-1 (HIV-1) establishes a latent viral reservoir soon after infection, which poses a major challenge for drug treatment and curative strategies. Many efforts are therefore focused on blocking infection. To this end, both viral and host factors relevant to the onset of infection need to be considered. Given that HIV-1 is most often transmitted mucosally, strategies designed to protect against infection need to be effective at mucosal portals of entry. These strategies need to contend also with cell-free and cell-associated transmitted/founder (T/F) virus forms; both can initiate and establish infection. This review will discuss how insight from the current model of HIV-1 mucosal transmission and cell entry has highlighted challenges in developing effective strategies to prevent infection. First, we examine key viral and host factors that play a role in transmission and infection. We then discuss preventive strategies based on antibody-mediated protection, with emphasis on targeting T/F viruses and mucosal immunity. Lastly, we review treatment strategies targeting viral entry, with focus on the most clinically advanced entry inhibitors.
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Affiliation(s)
- Jean-François Bruxelle
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Correspondence: (J.-F.B.); (R.P.)
| | - Nino Trattnig
- Chemical Biology and Drug Discovery, Utrecht University, 3584 CG Utrecht, The Netherlands;
| | - Marianne W. Mureithi
- KAVI—Institute of Clinical Research, College of Health Sciences, University of Nairobi, P.O. Box, Nairobi 19676–00202, Kenya;
| | - Elise Landais
- IAVI Neutralizing Antibody Center, La Jolla, CA 92037, USA;
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Ralph Pantophlet
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Correspondence: (J.-F.B.); (R.P.)
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30
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Jackman JA, Hakobyan A, Zakaryan H, Elrod CC. Inhibition of African swine fever virus in liquid and feed by medium-chain fatty acids and glycerol monolaurate. J Anim Sci Biotechnol 2020; 11:114. [PMID: 33292608 PMCID: PMC7722453 DOI: 10.1186/s40104-020-00517-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The ongoing African swine fever virus (ASFv) epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority. It has been recently identified that feed and feed ingredients, along with drinking water, can serve as transmission vehicles and might facilitate transboundary spread of ASFv. Thus, it is important to test the antiviral activity of regulatory compatible, antiviral feed additives that might inhibit ASFv infectivity in feed. One promising group of feed additive candidates includes medium-chain fatty acids (MCFA) and monoglyceride derivatives, which are known to disrupt the lipid membrane surrounding certain enveloped viruses and bacteria. RESULTS The antiviral activities of selected MCFA, namely caprylic, capric, and lauric acids, and a related monoglyceride, glycerol monolaurate (GML), to inhibit ASFv in liquid and feed conditions were investigated and suitable compounds and inclusion rates were identified that might be useful for mitigating ASFv in feed environments. Antiviral assays showed that all tested MCFA and GML inhibit ASFv. GML was more potent than MCFA because it worked at a lower concentration and inhibited ASFv due to direct virucidal activity along with one or more other antiviral mechanisms. Dose-dependent feed experiments further showed that sufficiently high GML doses can significantly reduce ASFv infectivity in feed in a linear manner in periods as short as 30 min, as determined by infectious viral titer measurements. Enzyme-linked immunosorbent assay (ELISA) experiments revealed that GML treatment also hinders antibody recognition of the membrane-associated ASFv p72 structural protein, which likely relates to protein conformational changes arising from viral membrane disruption. CONCLUSION Together, the findings in this study indicate that MCFA and GML inhibit ASFv in liquid conditions and that GML is also able to reduce ASFv infectivity in feed, which may help to curb disease transmission.
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Affiliation(s)
- Joshua A Jackman
- School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Astghik Hakobyan
- Group of Antiviral Defense Mechanisms, Institute of Molecular Biology of NAS, Yerevan, Armenia
| | - Hovakim Zakaryan
- Group of Antiviral Defense Mechanisms, Institute of Molecular Biology of NAS, Yerevan, Armenia
| | - Charles C Elrod
- Natural Biologics Inc., Newfield, NY, 14867, USA.
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
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31
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Wang HY, Bharti D, Levental I. Membrane Heterogeneity Beyond the Plasma Membrane. Front Cell Dev Biol 2020; 8:580814. [PMID: 33330457 PMCID: PMC7710808 DOI: 10.3389/fcell.2020.580814] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/02/2020] [Indexed: 01/21/2023] Open
Abstract
The structure and organization of cellular membranes have received intense interest, particularly in investigations of the raft hypothesis. The vast majority of these investigations have focused on the plasma membrane of mammalian cells, yielding significant progress in understanding membrane heterogeneity in terms of lipid composition, molecular structure, dynamic regulation, and functional relevance. In contrast, investigations on lipid organization in other membrane systems have been comparatively scarce, despite the likely relevance of membrane domains in these contexts. In this review, we summarize recent observations on lipid organization in organellar membranes, including endoplasmic reticulum, Golgi, endo-lysosomes, lipid droplets, and secreted membranes like lung surfactant, milk fat globule membranes, and viral membranes. Across these non-plasma membrane systems, it seems that the biophysical principles underlying lipid self-organization contribute to lateral domains.
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Affiliation(s)
- Hong-Yin Wang
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
| | - Deepti Bharti
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
- National Institute of Technology, Rourkela, India
| | - Ilya Levental
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
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32
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Lu M, Ma X, Reichard N, Terry DS, Arthos J, Smith AB, Sodroski JG, Blanchard SC, Mothes W. Shedding-Resistant HIV-1 Envelope Glycoproteins Adopt Downstream Conformations That Remain Responsive to Conformation-Preferring Ligands. J Virol 2020; 94:e00597-20. [PMID: 32522853 PMCID: PMC7431789 DOI: 10.1128/jvi.00597-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/05/2020] [Indexed: 12/25/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer of gp120-gp41 heterodimers mediates virus entry into CD4-positive (CD4+) cells. Single-molecule fluorescence resonance energy transfer (smFRET) has revealed that native Env on the surface of viruses predominantly exists in a pretriggered conformation (state 1) that is preferentially recognized by many broadly neutralizing antibodies (bNAbs). Env is activated by binding receptor CD4, which drives transitions through a default intermediate conformation (state 2) into the three-CD4-bound open conformation (state 3). The application of smFRET to assess the conformational state of existing Env constructs and ligand complexes recently revealed that all current high-resolution structures correspond to downstream states 2 and 3. The structure of state 1, therefore, remains unknown. We sought to identify conditions whereby HIV-1 Env could be stabilized in the pretriggered state 1 for possible structural characterization. Shedding of gp120, known to severely complicate structural studies, can be prevented by using the uncleaved gp160JR-FL precursor with alterations in the protease cleavage site (R508S/R511S) or by introducing a disulfide bridge between gp120 and gp41 designated "SOS" (A501C/T605C). smFRET demonstrated that both shedding-preventing modifications shifted the conformational landscape of Env downstream toward states 2 and 3. However, both membrane-bound Env proteins on the surface of intact viruses remained conformationally dynamic, responsive to state-stabilizing ligands, and able to be stabilized in state 1 by specific ligands such as the Bristol-Myers Squibb (BMS) entry inhibitors. The here-described identification of state 1-stabilizing conditions may enable structural characterization of the state 1 conformation of HIV-1 Env.IMPORTANCE The HIV-1 envelope glycoprotein (Env) opens in response to receptor CD4 binding from a pretriggered (state 1) conformation through a necessary intermediate to the three-CD4-bound conformation. The application of smFRET to test the conformational state of existing Env constructs and ligand complexes used for high-resolution structures recently revealed that they correspond to the downstream conformations. The structure of the pretriggered Env conformation, preferentially recognized by broadly neutralizing antibodies, remains unknown. Here, we identify experimental conditions that stabilize membrane-bound and shedding-resistant virus Env trimers in state 1, potentially facilitating structural characterization of this unknown conformational state.
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Affiliation(s)
- Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Xiaochu Ma
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Nick Reichard
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Daniel S Terry
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - James Arthos
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Amos B Smith
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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33
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Torralba J, de la Arada I, Carravilla P, Insausti S, Rujas E, Largo E, Eggeling C, Arrondo JLR, Apellániz B, Nieva JL. Cholesterol Constrains the Antigenic Configuration of the Membrane-Proximal Neutralizing HIV-1 Epitope. ACS Infect Dis 2020; 6:2155-2168. [PMID: 32584020 DOI: 10.1021/acsinfecdis.0c00243] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The envelope glycoprotein (Env) enables HIV-1 cell entry through fusion of host-cell and viral membranes induced by the transmembrane subunit gp41. Antibodies targeting the C-terminal sequence of the membrane-proximal external region (C-MPER) block the fusogenic activity of gp41 and achieve neutralization of divergent HIV-1 strains and isolates. Thus, recreating the structure that generates broadly neutralizing C-MPER antibodies during infection is a major goal in HIV vaccine development. Here, we have reconstituted a peptide termed CpreTM-TMD in a membrane environment. This peptide contains the C-MPER epitope and the minimum TMD residues required for the anchorage of the Env glycoprotein to the viral membrane. In addition, we have used antibody 10E8 variants to gauge the antigenic configuration attained by CpreTM-TMD as a function of the membrane cholesterol content, a functional determinant of the HIV envelope and liposome-based vaccines. Differential binding of the 10E8 variants and the trend of the IgG responses recovered from rabbits immunized with liposome-peptide formulations, suggested that cholesterol may restrict 10E8 accessibility to the C-MPER epitope. Our data ruled out the destabilization of the lipid bilayer architecture in CpreTM-TMD-containing membranes, and pointed to the perturbation of the helical conformation by lipid packing as the cause of the antigenic configuration loss induced by cholesterol. Overall, our results provide additional insights into the structural basis of the Env complex anchoring to membranes, and suggest new approaches to the design of effective immunogens directed against the near pan-neutralizing HIV-1 epitope C-MPER.
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Affiliation(s)
- Johana Torralba
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Igor de la Arada
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Pablo Carravilla
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Sara Insausti
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Edurne Rujas
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Eneko Largo
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Immunology, Microbiology and Parasitology, Medicine and Odontology Faculty, University of Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Christian Eggeling
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, OX3 9DS Oxford, U.K
| | - José L R Arrondo
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Beatriz Apellániz
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
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34
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Carravilla P, Nieva JL, Eggeling C. Fluorescence Microscopy of the HIV-1 Envelope. Viruses 2020; 12:E348. [PMID: 32245254 PMCID: PMC7150788 DOI: 10.3390/v12030348] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/18/2022] Open
Abstract
Human immunodeficiency virus (HIV) infection constitutes a major health and social issue worldwide. HIV infects cells by fusing its envelope with the target cell plasma membrane. This process is mediated by the viral Env glycoprotein and depends on the envelope lipid composition. Fluorescent microscopy has been employed to investigate the envelope properties, and the processes of viral assembly and fusion, but the application of this technique to the study of HIV is still limited by a number of factors, such as the small size of HIV virions or the difficulty to label the envelope components. Here, we review fluorescence imaging studies of the envelope lipids and proteins, focusing on labelling strategies and model systems.
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Affiliation(s)
- Pablo Carravilla
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany;
- Leibniz Institute of Photonic Technology, Albert Einstein Strasse 9, 07743 Jena, Germany
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain;
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, E-48940 Leioa, Spain
| | - José L. Nieva
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain;
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, E-48940 Leioa, Spain
| | - Christian Eggeling
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany;
- Leibniz Institute of Photonic Technology, Albert Einstein Strasse 9, 07743 Jena, Germany
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
- Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, 07743 Jena, Germany
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O'Donnell VB, Thomas D, Stanton R, Maillard JY, Murphy RC, Jones SA, Humphreys I, Wakelam MJO, Fegan C, Wise MP, Bosch A, Sattar SA. Potential Role of Oral Rinses Targeting the Viral Lipid Envelope in SARS-CoV-2 Infection. FUNCTION 2020; 1:zqaa002. [PMID: 33215159 PMCID: PMC7239187 DOI: 10.1093/function/zqaa002] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/04/2020] [Accepted: 05/08/2020] [Indexed: 01/06/2023] Open
Abstract
Emerging studies increasingly demonstrate the importance of the throat and salivary glands as sites of virus replication and transmission in early COVID-19 disease. SARS-CoV-2 is an enveloped virus, characterized by an outer lipid membrane derived from the host cell from which it buds. While it is highly sensitive to agents that disrupt lipid biomembranes, there has been no discussion about the potential role of oral rinsing in preventing transmission. Here, we review known mechanisms of viral lipid membrane disruption by widely available dental mouthwash components that include ethanol, chlorhexidine, cetylpyridinium chloride, hydrogen peroxide, and povidone-iodine. We also assess existing formulations for their potential ability to disrupt the SARS-CoV-2 lipid envelope, based on their concentrations of these agents, and conclude that several deserve clinical evaluation. We highlight that already published research on other enveloped viruses, including coronaviruses, directly supports the idea that oral rinsing should be considered as a potential way to reduce transmission of SARS-CoV-2. Research to test this could include evaluating existing or specifically tailored new formulations in well-designed viral inactivation assays, then in clinical trials. Population-based interventions could be undertaken with available mouthwashes, with active monitoring of outcome to determine efficacy. This is an under-researched area of major clinical need.
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Affiliation(s)
| | - David Thomas
- Systems Immunity Research Institute.,School of Dentistry
| | | | - Jean-Yves Maillard
- Systems Immunity Research Institute.,School of Pharmacy and Pharmaceutical Sciences, Cardiff University, CF14 4XN, UK
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Simon A Jones
- Systems Immunity Research Institute.,School of Medicine
| | - Ian Humphreys
- Systems Immunity Research Institute.,School of Medicine
| | | | | | - Matt P Wise
- University Hospital of Wales, Cardiff, CF14 4XW, UK
| | - Albert Bosch
- Enteric Virus Laboratory, University of Barcelona, 08028 Barcelona, Spain
| | - Syed A Sattar
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5 Canada
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