1
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Wang S, Chan KW, Wei D, Ma X, Liu S, Hu G, Park S, Pan R, Gu Y, Nazzari AF, Olia AS, Xu K, Lin BC, Louder MK, McKee K, Doria-Rose NA, Montefiori D, Seaman MS, Zhou T, Kwong PD, Arthos J, Kong XP, Lu S. Human CD4-binding site antibody elicited by polyvalent DNA prime-protein boost vaccine neutralizes cross-clade tier-2-HIV strains. Nat Commun 2024; 15:4301. [PMID: 38773089 PMCID: PMC11109196 DOI: 10.1038/s41467-024-48514-8] [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: 09/15/2023] [Accepted: 05/03/2024] [Indexed: 05/23/2024] Open
Abstract
The vaccine elicitation of HIV tier-2-neutralization antibodies has been a challenge. Here, we report the isolation and characterization of a CD4-binding site (CD4bs) specific monoclonal antibody, HmAb64, from a human volunteer immunized with a polyvalent DNA prime-protein boost HIV vaccine. HmAb64 is derived from heavy chain variable germline gene IGHV1-18 and light chain germline gene IGKV1-39. It has a third heavy chain complementarity-determining region (CDR H3) of 15 amino acids. On a cross-clade panel of 208 HIV-1 pseudo-virus strains, HmAb64 neutralized 20 (10%), including tier-2 strains from clades B, BC, C, and G. The cryo-EM structure of the antigen-binding fragment of HmAb64 in complex with a CNE40 SOSIP trimer revealed details of its recognition; HmAb64 uses both heavy and light CDR3s to recognize the CD4-binding loop, a critical component of the CD4bs. This study demonstrates that a gp120-based vaccine can elicit antibodies capable of tier 2-HIV neutralization.
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Affiliation(s)
- Shixia Wang
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
| | - Kun-Wei Chan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Danlan Wei
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Xiuwen Ma
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
| | - Shuying Liu
- SYL Consulting, Thousand Oak, CA, 91320, USA
| | - Guangnan Hu
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
| | - Saeyoung Park
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
| | - Ruimin Pan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Ying Gu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Alexandra F Nazzari
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Adam S Olia
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Kai Xu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Bob C Lin
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Mark K Louder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Krisha McKee
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | | | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02115, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - James Arthos
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Shan Lu
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA.
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2
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Bonner X, Sondgeroth A, McCue A, Nicely N, Tripathy A, Spielvogel E, Moeser M, Ke R, Leiderman K, Joseph SB, Swanstrom R. Stoichiometry for entry and binding properties of the Env protein of R5 T cell-tropic HIV-1 and its evolutionary variant of macrophage-tropic HIV-1. mBio 2024; 15:e0032124. [PMID: 38426750 DOI: 10.1128/mbio.00321-24] [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: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Human immunodeficiency virus type 1 typically requires a high density of CD4 for efficient entry as a mechanism to target CD4+ T cells (T-tropic), with CCR5 being used most often as the coreceptor. When target T cells are limiting, the virus can evolve to infect cells with a low density of CD4 such as macrophages (M-tropic). The entry phenotype is known to be encoded in the viral Env protein on the surface of the virus particle. Using data showing a dose response for infectivity based on CD4 surface density, we built a model consistent with T-tropic viruses requiring multiple CD4 molecules to mediate infection, whereas M-tropic viruses can infect cells using a single CD4 receptor molecule interaction. We also found that T-tropic viruses bound to the surface of cells with a low density of CD4 are released more slowly than M-tropic viruses which we modeled to be due to multiple interactions of the T-tropic virus with multiple CD4 molecules to allow the initial stable binding. Finally, we found that some M-tropic Env proteins, as the gp120 subunit, possess an enhanced affinity for CD4 compared with their T-tropic pair, indicating that the evolution of macrophage tropism can be reflected both in the closed Env trimer conformation on the virion surface and, in some cases, also in the open confirmation of gp120 Env. Collectively, these studies reveal differences in the stoichiometry of interaction of T-tropic and M-tropic viruses with CD4 and start to identify the basis of binding differences at the biochemical level. IMPORTANCE Human immunodeficiency virus type 1 normally targets CD4+ T cells for viral replication. When T cells are limiting, the virus can evolve to infect myeloid cells. The evolutionary step involves a change from requiring a high surface density of CD4 for entry to being able to infect cells with a low density of CD4, as is found on myeloid lineage cells such as macrophage and microglia. Viruses able to infect macrophages efficiently are most often found in the CNS late in the disease course, and such viruses may contribute to neurocognitive impairment. Here, we examine the CD4 binding properties of the viral Env protein to explore these two different entry phenotypes.
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Affiliation(s)
- Xavier Bonner
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Amy Sondgeroth
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Amelia McCue
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nathan Nicely
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ashutosh Tripathy
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ean Spielvogel
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Matthew Moeser
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ruian Ke
- T-6, Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Karin Leiderman
- Department of Mathematics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sarah B Joseph
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ronald Swanstrom
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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3
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Griffith S, Muir L, Suchanek O, Hope J, Pade C, Gibbons JM, Tuong ZK, Fung A, Touizer E, Rees-Spear C, Nans A, Roustan C, Alguel Y, Fink D, Orkin C, Deayton J, Anderson J, Gupta RK, Doores KJ, Cherepanov P, McKnight Á, Clatworthy M, McCoy LE. Preservation of memory B cell homeostasis in an individual producing broadly neutralising antibodies against HIV-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.05.578789. [PMID: 38370662 PMCID: PMC10871235 DOI: 10.1101/2024.02.05.578789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Immunological determinants favouring emergence of broadly neutralising antibodies are crucial to the development of HIV-1 vaccination strategies. Here, we combined RNAseq and B cell cloning approaches to isolate a broadly neutralising antibody (bnAb) ELC07 from an individual living with untreated HIV-1. Using single particle cryogenic electron microscopy (cryo-EM), we show that the antibody recognises a conformational epitope at the gp120-gp41 interface. ELC07 binds the closed state of the viral glycoprotein causing considerable perturbations to the gp41 trimer core structure. Phenotypic analysis of memory B cell subsets from the ELC07 bnAb donor revealed a lack of expected HIV-1-associated dysfunction, specifically no increase in CD21-/CD27- cells was observed whilst the resting memory (CD21+/CD27+) population appeared preserved despite uncontrolled HIV-1 viraemia. Moreover, single cell transcriptomes of memory B cells from this bnAb donor showed a resting memory phenotype irrespective of the epitope they targeted or their ability to neutralise diverse strains of HIV-1. Strikingly, single memory B cells from the ELC07 bnAb donor were transcriptionally similar to memory B cells from HIV-negative individuals. Our results demonstrate that potent bnAbs can arise without the HIV-1-induced dysregulation of the memory B cell compartment and suggest that sufficient levels of antigenic stimulation with a strategically designed immunogen could be effective in HIV-negative vaccine recipients.
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Affiliation(s)
- Sarah Griffith
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Luke Muir
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Ondrej Suchanek
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, UK
- Cambridge University Hospitals NHS Foundation Trust, and NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - Joshua Hope
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Corinna Pade
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Joseph M Gibbons
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Zewen Kelvin Tuong
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, UK
- Cellular Genetics, Wellcome Sanger Institute, Cambridge, UK
- Ian Frazer Centre for Children's Immunotherapy Research, Child Health Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Audrey Fung
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Emma Touizer
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Chloe Rees-Spear
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Andrea Nans
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Chloe Roustan
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Yilmaz Alguel
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Douglas Fink
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
| | - Chloe Orkin
- SHARE collaborative, Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Jane Deayton
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Jane Anderson
- Homerton University Hospital NHS Foundation, London, UK
| | - Ravindra K Gupta
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), Cambridge, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Katie J Doores
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London, UK
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
- Department of Infectious Disease, St-Mary's Campus, Imperial College London, London, UK
| | - Áine McKnight
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Menna Clatworthy
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, UK
- Cambridge University Hospitals NHS Foundation Trust, and NIHR Cambridge Biomedical Research Centre, Cambridge, UK
- Cellular Genetics, Wellcome Sanger Institute, Cambridge, UK
- Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), Cambridge, UK
| | - Laura E McCoy
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, UK
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4
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Bennett AL, Edwards R, Kosheleva I, Saunders C, Bililign Y, Williams A, Bubphamala P, Manosouri K, Anasti K, Saunders KO, Alam SM, Haynes BF, Acharya P, Henderson R. Microsecond dynamics control the HIV-1 Envelope conformation. SCIENCE ADVANCES 2024; 10:eadj0396. [PMID: 38306419 PMCID: PMC10836732 DOI: 10.1126/sciadv.adj0396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/03/2024] [Indexed: 02/04/2024]
Abstract
The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although remarkable progress has been made in understanding the structures of various Env conformations, microsecond timescale dynamics have not been studied experimentally. Here, we used time-resolved, temperature-jump small-angle x-ray scattering to monitor structural rearrangements in an HIV-1 Env SOSIP ectodomain construct with microsecond precision. In two distinct Env variants, we detected a transition that correlated with known Env structure rearrangements with a time constant in the hundreds of microseconds range. A previously unknown structural transition was also observed, which occurred with a time constant below 10 μs, and involved an order-to-disorder transition in the trimer apex. Using this information, we engineered an Env SOSIP construct that locks the trimer in the prefusion closed state by connecting adjacent protomers via disulfides. Our findings show that the microsecond timescale structural dynamics play an essential role in controlling the Env conformation with impacts on vaccine design.
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Affiliation(s)
- Ashley L. Bennett
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Robert Edwards
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Irina Kosheleva
- BioCARS, Center for Advanced Radiation Sources, The University of Chicago, 9700 South Cass Ave, Bld 434B, Lemont, IL 60439, USA
| | - Carrie Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Yishak Bililign
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Ashliegh Williams
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Pimthada Bubphamala
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Katayoun Manosouri
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kara Anasti
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kevin O. Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - S. Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
- Department of Pathology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- BioCARS, Center for Advanced Radiation Sources, The University of Chicago, 9700 South Cass Ave, Bld 434B, Lemont, IL 60439, USA
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Rory Henderson
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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5
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Van Ryk D, Vimonpatranon S, Hiatt J, Ganesan S, Chen N, McMurry J, Garba S, Min S, Goes LR, Girard A, Yolitz J, Licavoli I, Wei D, Huang D, Soares MA, Martinelli E, Cicala C, Arthos J. The V2 domain of HIV gp120 mimics an interaction between CD4 and integrin ⍺4β7. PLoS Pathog 2023; 19:e1011860. [PMID: 38064524 PMCID: PMC10732398 DOI: 10.1371/journal.ppat.1011860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 12/20/2023] [Accepted: 11/25/2023] [Indexed: 12/21/2023] Open
Abstract
The CD4 receptor, by stabilizing TCR-MHC II interactions, plays a central role in adaptive immunity. It also serves as the HIV docking receptor. The HIV gp120 envelope protein binds directly to CD4. This interaction is a prerequisite for viral entry. gp120 also binds to ⍺4β7, an integrin that is expressed on a subset of memory CD4+ T cells. HIV tropisms for CD4+ T cells and gut tissues are central features of HIV pathogenesis. We report that CD4 binds directly to ⍺4β7 in a dynamic way, consistent with a cis regulatory interaction. The molecular details of this interaction are related to the way in which gp120 interacts with both receptors. Like MAdCAM-1 and VCAM-1, two recognized ligands of ⍺4β7, the binding interface on CD4 includes 2 sites (1° and accessory), distributed across its two N-terminal IgSF domains (D1 and D2). The 1° site includes a sequence in the G β-strand of CD4 D2, KIDIV, that binds directly to ⍺4β7. This pentapeptide sequence occurs infrequently in eukaryotic proteins. However, a closely related and conserved sequence, KLDIV, appears in the V2 domain of gp120. KLDIV mediates gp120-⍺4β7 binding. The accessory ⍺4β7 binding site on CD4 includes Phe43. The Phe43 aromatic ring protrudes outward from one edge of a loop connecting the C'C" strands of CD4 D1. Phe43 is a principal contact for HIV gp120. It interacts with conserved residues in the recessed CD4 binding pocket. Substitution of Phe43 abrogates CD4 binding to both gp120 and ⍺4β7. As such, the interactions of gp120 with both CD4 and ⍺4β7 reflect elements of their interactions with each other. These findings indicate that gp120 specificities for CD4 and ⍺4β7 are interrelated and suggest that selective pressures which produced a CD4 tropic virus that replicates in gut tissues are linked to a dynamic interaction between these two receptors.
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Affiliation(s)
- Donald Van Ryk
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Sinmanus Vimonpatranon
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences–United States Component, Bangkok, Thailand
| | - Joe Hiatt
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Sundar Ganesan
- Biological Imaging Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Nathalie Chen
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jordan McMurry
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Saadiq Garba
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Susie Min
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Livia R. Goes
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
- Oncovirology Program, Instituto Nacional de Câncer, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alexandre Girard
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jason Yolitz
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Isabella Licavoli
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Danlan Wei
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Dawei Huang
- Lymphoid Malignancies Branch, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Marcelo A. Soares
- Oncovirology Program, Instituto Nacional de Câncer, Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Genetics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Elena Martinelli
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Claudia Cicala
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - James Arthos
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
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6
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Li W, Qin Z, Nand E, Grunst MW, Grover JR, Bess JW, Lifson JD, Zwick MB, Tagare HD, Uchil PD, Mothes W. HIV-1 Env trimers asymmetrically engage CD4 receptors in membranes. Nature 2023; 623:1026-1033. [PMID: 37993716 PMCID: PMC10686830 DOI: 10.1038/s41586-023-06762-6] [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: 12/24/2022] [Accepted: 10/19/2023] [Indexed: 11/24/2023]
Abstract
Human immunodeficiency virus 1 (HIV-1) infection is initiated by binding of the viral envelope glycoprotein (Env) to the cell-surface receptor CD41-4. Although high-resolution structures of Env in a complex with the soluble domains of CD4 have been determined, the binding process is less understood in native membranes5-13. Here we used cryo-electron tomography to monitor Env-CD4 interactions at the membrane-membrane interfaces formed between HIV-1 and CD4-presenting virus-like particles. Env-CD4 complexes organized into clusters and rings, bringing the opposing membranes closer together. Env-CD4 clustering was dependent on capsid maturation. Subtomogram averaging and classification revealed that Env bound to one, two and finally three CD4 molecules, after which Env adopted an open state. Our data indicate that asymmetric HIV-1 Env trimers bound to one and two CD4 molecules are detectable intermediates during virus binding to host cell membranes, which probably has consequences for antibody-mediated immune responses and vaccine immunogen design.
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Affiliation(s)
- Wenwei Li
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA.
| | - Zhuan Qin
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Elizabeth Nand
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Michael W Grunst
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Jonathan R Grover
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Julian W Bess
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Michael B Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Hemant D Tagare
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Pradeep D Uchil
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA.
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7
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Dam KMA, Fan C, Yang Z, Bjorkman PJ. Intermediate conformations of CD4-bound HIV-1 Env heterotrimers. Nature 2023; 623:1017-1025. [PMID: 37993719 PMCID: PMC10686819 DOI: 10.1038/s41586-023-06639-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 09/13/2023] [Indexed: 11/24/2023]
Abstract
HIV-1 envelope (Env) exhibits distinct conformational changes in response to host receptor (CD4) engagement. Env, a trimer of gp120 and gp41 heterodimers, has been structurally characterized in a closed, prefusion conformation with closely associated gp120s and coreceptor binding sites on gp120 V3 hidden by V1V2 loops1-4 and in fully saturated CD4-bound open Env conformations with changes including outwardly rotated gp120s and displaced V1V2 loops3-9. To investigate changes resulting from substoichiometric CD4 binding, we solved single-particle cryo-electron microscopy (cryo-EM) structures of soluble, native-like heterotrimeric Envs bound to one or two CD4 molecules. Most of the Env trimers bound to one CD4 adopted the closed, prefusion Env state, with a minority exhibiting a heterogeneous partially open Env conformation. When bound to two CD4s, the CD4-bound gp120s exhibited an open Env conformation including a four-stranded gp120 bridging sheet and displaced gp120 V1V2 loops that expose the coreceptor sites on V3. The third gp120 adopted an intermediate, occluded-open state10 that showed gp120 outward rotation but maintained the prefusion three-stranded gp120 bridging sheet with only partial V1V2 displacement and V3 exposure. We conclude that most of the engagements with one CD4 molecule were insufficient to stimulate CD4-induced conformational changes, whereas binding two CD4 molecules led to Env opening in CD4-bound protomers only. The substoichiometric CD4-bound soluble Env heterotrimer structures resembled counterparts derived from a cryo-electron tomography study of complexes between virion-bound Envs and membrane-anchored CD4 (ref. 11), validating their physiological relevance. Together, these results illuminate intermediate conformations of HIV-1 Env and illustrate its structural plasticity.
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Affiliation(s)
- Kim-Marie A Dam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Chengcheng Fan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Zhi Yang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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8
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Wang S, Chan KW, Wei D, Ma X, Liu S, Hu G, Park S, Pan R, Gu Y, Nazzari AF, Olia AS, Xu K, Lin BC, Louder MK, Doria-Rose NA, Montefiori D, Seaman MS, Zhou T, Kwong PD, Arthos J, Kong XP, Lu S. Human CD4-Binding Site Antibody Elicited by Polyvalent DNA Prime-Protein Boost Vaccine Neutralizes Cross-Clade Tier-2-HIV Strains. RESEARCH SQUARE 2023:rs.3.rs-3360161. [PMID: 37886518 PMCID: PMC10602183 DOI: 10.21203/rs.3.rs-3360161/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The vaccine elicitation of HIV-neutralizing antibodies with tier-2-neutralization breadth has been a challenge. Here, we report the isolation and characteristics of a CD4-binding site specific monoclonal antibody, HmAb64, from a human volunteer immunized with a polyvalent gp120 DNA prime-protein boost vaccine. HmAb64 derived from heavy chain variable germline gene IGHV1-18, light chain germline gene IGKV1-39, and had a 3rd heavy chain complementarity determining region (CDR H3) of 15 amino acids. On a cross-clade panel of 208 HIV-1 pseudo-virus strains, HmAb64 neutralized 21 (10%), including tier-2 neutralization resistant strains from clades B, BC, C, and G. The cryo-EM structure of the antigen-binding fragment of HmAb64 bound to a conformation between prefusion closed and occluded open forms of envelope trimer, using both heavy and light CDR3s to recognize the CD4-binding loop, a critical component of the CD4-binding site. A gp120 subunit-based vaccine can thus elicit an antibody capable of tier 2-HIV neutralization.
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Affiliation(s)
- Shixia Wang
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Kun-Wei Chan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Danlan Wei
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Xiuwen Ma
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | | | - Guangnan Hu
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Saeyoung Park
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Ruimin Pan
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ying Gu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Alexandra F Nazzari
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Adam S Olia
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Kai Xu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Bob C Lin
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Mark K Louder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | | | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - James Arthos
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Shan Lu
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
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9
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Rao PG, Lambert GS, Upadhyay C. Broadly neutralizing antibody epitopes on HIV-1 particles are exposed after virus interaction with host cells. J Virol 2023; 97:e0071023. [PMID: 37681958 PMCID: PMC10537810 DOI: 10.1128/jvi.00710-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/07/2023] [Indexed: 09/09/2023] Open
Abstract
The envelope (Env) glycoproteins on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAbs) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes, including V2i, the gp120-g41 interface, and gp41-MPER, are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by the pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where the virus-mAb mix was pre-incubated/not pre-incubated for 1 hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use. IMPORTANCE The human immunodeficiency virus (HIV-1) envelope (Env) glycoprotein mediates viral entry and is the sole target of neutralizing antibodies. Our data suggest that antibody epitopes including V2q (e.g., PG9, PGT145), CD4bs (e.g., VRC01, 3BNC117), and V3 (2219, 2557) are masked on HIV-1 particles. The PG9 and 2219 epitopes became accessible for binding after conformational unmasking was induced by the pre-binding of select mAbs. Attempts to understand the masking mechanism led to the revelation that interaction between virus and host cells is needed to sensitize the virions for neutralization by broadly neutralizing antibodies (bNAbs). These data provide insight on how bNAbs may gain access to these occluded epitopes to exert their neutralization effects and block HIV-1 infection. These findings have important implications for the way we evaluate the neutralizing efficacy of antibodies and can potentially guide vaccine design.
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Affiliation(s)
- Priyanka Gadam Rao
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gregory S. Lambert
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Chitra Upadhyay
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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10
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Glögl M, Friedrich N, Cerutti G, Lemmin T, Kwon YD, Gorman J, Maliqi L, Mittl PRE, Hesselman MC, Schmidt D, Weber J, Foulkes C, Dingens AS, Bylund T, Olia AS, Verardi R, Reinberg T, Baumann NS, Rusert P, Dreier B, Shapiro L, Kwong PD, Plückthun A, Trkola A. Trapping the HIV-1 V3 loop in a helical conformation enables broad neutralization. Nat Struct Mol Biol 2023; 30:1323-1336. [PMID: 37605043 PMCID: PMC10497408 DOI: 10.1038/s41594-023-01062-z] [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: 09/23/2022] [Accepted: 07/11/2023] [Indexed: 08/23/2023]
Abstract
The third variable (V3) loop on the human immunodeficiency virus 1 (HIV-1) envelope glycoprotein trimer is indispensable for virus cell entry. Conformational masking of V3 within the trimer allows efficient neutralization via V3 only by rare, broadly neutralizing glycan-dependent antibodies targeting the closed prefusion trimer but not by abundant antibodies that access the V3 crown on open trimers after CD4 attachment. Here, we report on a distinct category of V3-specific inhibitors based on designed ankyrin repeat protein (DARPin) technology that reinstitute the CD4-bound state as a key neutralization target with up to >90% breadth. Broadly neutralizing DARPins (bnDs) bound V3 solely on open envelope and recognized a four-turn amphipathic α-helix in the carboxy-terminal half of V3 (amino acids 314-324), which we termed 'αV3C'. The bnD contact surface on αV3C was as conserved as the CD4 binding site. Molecular dynamics and escape mutation analyses underscored the functional relevance of αV3C, highlighting the potential of αV3C-based inhibitors and, more generally, of postattachment inhibition of HIV-1.
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Affiliation(s)
- Matthias Glögl
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Nikolas Friedrich
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Gabriele Cerutti
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Thomas Lemmin
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Young D Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Liridona Maliqi
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Peer R E Mittl
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Maria C Hesselman
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Daniel Schmidt
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Jacqueline Weber
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Caio Foulkes
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Adam S Dingens
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Tatsiana Bylund
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Adam S Olia
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thomas Reinberg
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Nicolas S Baumann
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Peter Rusert
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Birgit Dreier
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Lawrence Shapiro
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Alexandra Trkola
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland.
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11
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Cervantes M, Hess T, Morbioli GG, Sengar A, Kasson PM. The ACE2 receptor accelerates but is not biochemically required for SARS-CoV-2 membrane fusion. Chem Sci 2023; 14:6997-7004. [PMID: 37389252 PMCID: PMC10306070 DOI: 10.1039/d2sc06967a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 06/05/2023] [Indexed: 07/01/2023] Open
Abstract
The SARS-CoV-2 coronavirus infects human cells via the ACE2 receptor. Structural evidence suggests that ACE2 may not just serve as an attachment factor but also conformationally activate the SARS-CoV-2 spike protein for membrane fusion. Here, we test that hypothesis directly, using DNA-lipid tethering as a synthetic attachment factor in place of ACE2. We find that SARS-CoV-2 pseudovirus and virus-like particles are capable of membrane fusion without ACE2 if activated with an appropriate protease. Thus, ACE2 is not biochemically required for SARS-CoV-2 membrane fusion. However, addition of soluble ACE2 speeds up the fusion reaction. On a per-spike level, ACE2 appears to promote activation for fusion and then subsequent inactivation if an appropriate protease is not present. Kinetic analysis suggests at least two rate-limiting steps for SARS-CoV-2 membrane fusion, one of which is ACE2 dependent and one of which is not. Since ACE2 serves as a high-affinity attachment factor on human cells, the possibility to replace it with other factors implies a flatter fitness landscape for host adaptation by SARS-CoV-2 and future related coronaviruses.
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Affiliation(s)
- Marcos Cervantes
- Departments of Molecular Physiology and Biomedical Engineering, University of Virginia Charlottesville VA 22908 USA
| | - Tobin Hess
- Departments of Molecular Physiology and Biomedical Engineering, University of Virginia Charlottesville VA 22908 USA
| | - Giorgio G Morbioli
- Departments of Molecular Physiology and Biomedical Engineering, University of Virginia Charlottesville VA 22908 USA
| | - Anjali Sengar
- Departments of Molecular Physiology and Biomedical Engineering, University of Virginia Charlottesville VA 22908 USA
| | - Peter M Kasson
- Departments of Molecular Physiology and Biomedical Engineering, University of Virginia Charlottesville VA 22908 USA
- Science for Life Laboratory and Department of Molecular and Cellular Biology, Uppsala University Uppsala SE 75123 USA
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12
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Colin P, Ringe RP, Yasmeen A, Ozorowski G, Ketas TJ, Lee WH, Ward AB, Moore JP, Klasse PJ. Conformational antigenic heterogeneity as a cause of the persistent fraction in HIV-1 neutralization. Retrovirology 2023; 20:9. [PMID: 37244989 DOI: 10.1186/s12977-023-00624-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/15/2023] [Indexed: 05/29/2023] Open
Abstract
BACKGROUND Neutralizing antibodies (NAbs) protect against HIV-1 acquisition in animal models and show promise in treatment of infection. They act by binding to the viral envelope glycoprotein (Env), thereby blocking its receptor interactions and fusogenic function. The potency of neutralization is largely determined by affinity. Less well explained is the persistent fraction, the plateau of remaining infectivity at the highest antibody concentrations. RESULTS We observed different persistent fractions for neutralization of pseudovirus derived from two Tier-2 isolates of HIV-1, BG505 (Clade A) and B41 (Clade B): it was pronounced for B41 but not BG505 neutralization by NAb PGT151, directed to the interface between the outer and transmembrane subunits of Env, and negligible for either virus by NAb PGT145 to an apical epitope. Autologous neutralization by poly- and monoclonal NAbs from rabbits immunized with soluble native-like B41 trimer also left substantial persistent fractions. These NAbs largely target a cluster of epitopes lining a hole in the dense glycan shield of Env around residue 289. We partially depleted B41-virion populations by incubating them with PGT145- or PGT151-conjugated beads. Each depletion reduced the sensitivity to the depleting NAb and enhanced it to the other. Autologous neutralization by the rabbit NAbs was decreased for PGT145-depleted and enhanced for PGT151-depleted B41 pseudovirus. Those changes in sensitivity encompassed both potency and the persistent fraction. We then compared soluble native-like BG505 and B41 Env trimers affinity-purified by each of three NAbs: 2G12, PGT145, or PGT151. Surface plasmon resonance showed differences among the fractions in antigenicity, including kinetics and stoichiometry, congruently with the differential neutralization. The large persistent fraction after PGT151 neutralization of B41 was attributable to low stoichiometry, which we explained structurally by clashes that the conformational plasticity of B41 Env causes. CONCLUSION Distinct antigenic forms even of clonal HIV-1 Env, detectable among soluble native-like trimer molecules, are distributed over virions and may profoundly mold neutralization of certain isolates by certain NAbs. Affinity purifications with some antibodies may yield immunogens that preferentially expose epitopes for broadly active NAbs, shielding less cross-reactive ones. NAbs reactive with multiple conformers will together reduce the persistent fraction after passive and active immunization.
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Affiliation(s)
- Philippe Colin
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, 1300 York Avenue, 62 , New York, NY, 10065, USA
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
| | - Rajesh P Ringe
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, 1300 York Avenue, 62 , New York, NY, 10065, USA
- Virology Unit, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR), Chandigarh, India
| | - Anila Yasmeen
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, 1300 York Avenue, 62 , New York, NY, 10065, USA
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, Consortium for HIV Vaccine 14 Development (CHAVD), The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Thomas J Ketas
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, 1300 York Avenue, 62 , New York, NY, 10065, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, Consortium for HIV Vaccine 14 Development (CHAVD), The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, Consortium for HIV Vaccine 14 Development (CHAVD), The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - John P Moore
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, 1300 York Avenue, 62 , New York, NY, 10065, USA
| | - P J Klasse
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, 1300 York Avenue, 62 , New York, NY, 10065, USA.
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13
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Bennett AL, Edwards RJ, Kosheleva I, Saunders C, Bililign Y, Williams A, Manosouri K, Saunders KO, Haynes BF, Acharya P, Henderson R. Microsecond dynamics control the HIV-1 envelope conformation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.17.541130. [PMID: 37292605 PMCID: PMC10245784 DOI: 10.1101/2023.05.17.541130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although significant progress has been made in understanding the structures of various Env conformations and transition intermediates that occur within the millisecond timescale, faster transitions in the microsecond timescale have not yet been observed. In this study, we employed time-resolved, temperature-jump small angle X-ray scattering to monitor structural rearrangements in an HIV-1 Env ectodomain construct with microsecond precision. We detected a transition correlated with Env opening that occurs in the hundreds of microseconds range and another more rapid transition that preceded this opening. Model fitting indicated that the early rapid transition involved an order-to-disorder transition in the trimer apex loop contacts, suggesting that conventional conformation-locking design strategies that target the allosteric machinery may be ineffective in preventing this movement. Utilizing this information, we engineered an envelope that locks the apex loop contacts to the adjacent protomer. This modification resulted in significant angle-of-approach shifts in the interaction of a neutralizing antibody. Our findings imply that blocking the intermediate state could be crucial for inducing antibodies with the appropriate bound state orientation through vaccination.
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Affiliation(s)
- Ashley L Bennett
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - R J Edwards
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Irina Kosheleva
- BioCARS, Center for Advanced Radiation Sources, The University of Chicago, 9700 South Cass Ave, Bld 434B, Lemont, IL 60439, USA
| | - Carrie Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Yishak Bililign
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Ashliegh Williams
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Katayoun Manosouri
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Rory Henderson
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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14
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Rao PG, Lambert GS, Upadhyay C. Broadly Neutralizing Antibody Epitopes on HIV-1 Particles are exposed after Virus Interaction with Host Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524996. [PMID: 36711466 PMCID: PMC9882293 DOI: 10.1101/2023.01.20.524996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The envelope glycoproteins (Env) on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAb) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes including V2i, gp120-g41 interface, and gp41-MPER are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where virus-mAb mix was pre-incubated/not pre-incubated for one hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are the ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use.
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15
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Grunst MW, Ladd RA, Clark NM, Gil HM, Klenchin VA, Mason R, Franchini G, Roederer M, Evans DT. Antibody-dependent cellular cytotoxicity, infected cell binding and neutralization by antibodies to the SIV envelope glycoprotein. PLoS Pathog 2023; 19:e1011407. [PMID: 37253062 PMCID: PMC10256149 DOI: 10.1371/journal.ppat.1011407] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 06/09/2023] [Accepted: 05/08/2023] [Indexed: 06/01/2023] Open
Abstract
Antibodies specific for diverse epitopes of the simian immunodeficiency virus envelope glycoprotein (SIV Env) have been isolated from rhesus macaques to provide physiologically relevant reagents for investigating antibody-mediated protection in this species as a nonhuman primate model for HIV/AIDS. With increasing interest in the contribution of Fc-mediated effector functions to protective immunity, we selected thirty antibodies representing different classes of SIV Env epitopes for a comparison of antibody-dependent cellular cytotoxicity (ADCC), binding to Env on the surface of infected cells and neutralization of viral infectivity. These activities were measured against cells infected with neutralization-sensitive (SIVmac316 and SIVsmE660-FL14) and neutralization-resistant (SIVmac239 and SIVsmE543-3) viruses representing genetically distinct isolates. Antibodies to the CD4-binding site and CD4-inducible epitopes were identified with especially potent ADCC against all four viruses. ADCC correlated well with antibody binding to virus-infected cells. ADCC also correlated with neutralization. However, several instances of ADCC without detectable neutralization or neutralization without detectable ADCC were observed. The incomplete correspondence between ADCC and neutralization shows that some antibody-Env interactions can uncouple these antiviral activities. Nevertheless, the overall correlation between neutralization and ADCC implies that most antibodies that are capable of binding to Env on the surface of virions to block infectivity are also capable of binding to Env on the surface of virus-infected cells to direct their elimination by ADCC.
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Affiliation(s)
- Michael W. Grunst
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ruby A. Ladd
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Natasha M. Clark
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Hwi Min Gil
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Vadim A. Klenchin
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Rosemarie Mason
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Genoveffa Franchini
- Animal Models and Retroviral Vaccines Section, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Mario Roederer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - David T. Evans
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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16
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Colin P, Ringe RP, Yasmeen A, Ozorowski G, Ketas TJ, Lee WH, Ward AB, Moore JP, Klasse P. Conformational antigenic heterogeneity as a cause of the persistent fraction in HIV-1 neutralization. RESEARCH SQUARE 2023:rs.3.rs-2613503. [PMID: 36865101 PMCID: PMC9980222 DOI: 10.21203/rs.3.rs-2613503/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Background Neutralizing antibodies (NAbs) protect against HIV-1 acquisition in animal models and show promise in treatment of infection. They act by binding to the viral envelope glycoprotein (Env), thereby blocking its receptor interactions and fusogenic function. The potency of neutralization is largely determined by affinity. Less well explained is the persistent fraction, the plateau of remaining infectivity at the highest antibody concentrations. Results We observed different persistent fractions for NAb neutralization of pseudovirus derived from two Tier-2 isolates of HIV-1, BG505 (Clade A) and B41 (Clade B): it was pronounced for B41 but not BG505 neutralization by NAb PGT151, directed to the interface between the outer and transmembrane subunits of Env, but negligible for either virus by NAb PGT145 to an apical epitope. Autologous neutralization by poly- and monoclonal NAbs from rabbits immunized with soluble native-like B41 trimer also left substantial persistent fractions. These NAbs largely target a cluster of epitopes in a hole in the dense glycan shield of Env around residue 289. We partially depleted B41-virion populations by incubating them with PGT145- or PGT151-conjugated beads. Each depletion reduced the sensitivity to the depleting NAb and enhanced it to the other. Autologous neutralization by the rabbit NAbs was reduced for PGT145-depleted and enhanced for PGT151-depleted B41 pseudovirus. Those changes in sensitivity encompassed both potency and the persistent fraction. We then compared soluble native-like BG505 and B41 Env trimers affinity-purified by one of three NAbs: 2G12, PGT145, or PGT151. Surface plasmon resonance showed differences among the fractions in antigenicity, including kinetics and stoichiometry, congruently with the differential neutralization. The large persistent fraction after PGT151 neutralization of B41 was attributable to low stoichiometry, which we explained structurally by the conformational plasticity of B41 Env. Conclusion Distinct antigenic forms even of clonal HIV-1 Env, detectable among soluble native-like trimer molecules, are distributed over virions and may profoundly mold neutralization of certain isolates by certain NAbs. Affinity purifications with some antibodies may yield immunogens that preferentially expose epitopes for broadly active NAbs, while shielding less cross-reactive ones. NAbs reactive with multiple conformers will together reduce the persistent fraction after passive and active immunization.
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Dam KMA, Fan C, Yang Z, Bjorkman PJ. Structural characterization of HIV-1 Env heterotrimers bound to one or two CD4 receptors reveals intermediate Env conformations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.27.525985. [PMID: 36747804 PMCID: PMC9900888 DOI: 10.1101/2023.01.27.525985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
HIV-1 envelope (Env) exhibits distinct conformational changes in response to host receptor (CD4) engagement. Env, a trimer of gp120/gp41 heterodimers, has been structurally characterized in a closed, prefusion conformation with closely associated gp120s and coreceptor binding sites on gp120 V3 hidden by V1V2 loops, and in fully-saturated CD4-bound open Env conformations with changes including outwardly rotated gp120s and displaced V1V2 loops. To investigate changes resulting from sub-stoichiometric CD4 binding, we solved 3.4Å and 3.9Å single-particle cryo-EM structures of soluble, native-like Envs bound to one or two CD4 molecules. Env trimer bound to one CD4 adopted the closed, prefusion Env state. When bound to two CD4s, the CD4-bound gp120s exhibited an open Env conformation including a four-stranded gp120 bridging sheet and displaced gp120 V1V2 loops that expose the coreceptor sites on V3. The third gp120 adopted an intermediate, occluded-open state that included gp120 outward rotation but maintained the prefusion, three-stranded gp120 bridging sheet and showed only partial V1V2 displacement and V3 exposure. We conclude that engagement of one CD4 molecule was insufficient to stimulate CD4-induced conformational changes, while binding two CD4 molecules led to Env opening in CD4-bound protomers only. Together, these results illuminate HIV-1 Env intermediate conformations and illustrate the structural plasticity of HIV-1 Env.
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Affiliation(s)
- Kim-Marie A Dam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Chengcheng Fan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Zhi Yang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Present address: Department of Molecular and Cell Biology, University of California, 13 Berkeley, CA 94720, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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18
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Abstract
Human immunodeficiency virus type 1 (HIV-1) envelope (Env), a heterotrimer of gp120-gp41 subunits, mediates fusion of the viral and host cell membranes after interactions with the host receptor CD4 and a coreceptor. CD4 binding induces rearrangements in Env trimer, resulting in a CD4-induced (CD4i) open Env conformation. Structural studies of antibodies isolated from infected donors have defined antibody-Env interactions, with one class of antibodies specifically recognizing the CD4i open Env conformation. In this study, we characterized a group of monoclonal antibodies isolated from HIV-1 infected donors (V2i MAbs) that displayed characteristics of CD4i antibodies. Binding experiments demonstrated that the V2i MAbs preferentially recognize CD4-bound open Env trimers. Structural characterizations of V2i MAb-Env-CD4 trimer complexes using single-particle cryo-electron microscopy showed recognition by V2i MAbs using different angles of approach to the gp120 V1V2 domain and the β2/β3 strands on a CD4i open conformation Env with no direct interactions of the MAbs with CD4. We also characterized CG10, a CD4i antibody that was raised in mice immunized with a gp120-CD4 complex, bound to an Env trimer plus CD4. CG10 exhibited characteristics similar to those of the V2i antibodies, i.e., recognition of the open Env conformation, but showed direct contacts to both CD4 and gp120. Structural comparisons of these and previously characterized CD4i antibody interactions with Env provide a suggested mechanism for how these antibodies are elicited during HIV-1 infection. IMPORTANCE The RV144 HIV-1 clinical vaccination trial showed modest protection against viral infection. Antibody responses to the V1V2 region of HIV-1 Env gp120 were correlated inversely with the risk of infection, and data from three other clinical vaccine trials suggested a similar signal. In addition, antibodies targeting V1V2 have been correlated with protections from simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus (SHIV) infections in nonhuman primates. We structurally characterized V2i antibodies directed against V1V2 isolated from HIV-1 infected humans in complex with open Env trimers bound to the host receptor CD4. We also characterized a CD4i antibody that interacts with CD4 as well as the gp120 subunit of an open Env trimer. Our study suggests how V2i and CD4i antibodies were elicited during HIV-1 infection.
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Wang R, Tsuji K, Kobayakawa T, Liu Y, Yoshimura K, Matsushita S, Harada S, Tamamura H. Hybrids of small CD4 mimics and gp41-related peptides as dual-target HIV entry inhibitors. Bioorg Med Chem 2022; 76:117083. [PMID: 36403413 DOI: 10.1016/j.bmc.2022.117083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/29/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022]
Abstract
Hybrid molecules containing small CD4 mimics and gp41-C-terminal heptad repeat (CHR)-related peptides have been developed. A YIR-821 derivative was adopted as a CD4 mimic, which inhibits the interaction of gp120 with CD4. SC-peptides, SC34 and SC22EK, were also used as CHR-related peptides, which inhibit the interaction between the N-terminal heptad repeat (NHR) and CHR and thereby membrane fusion. Therefore, these hybrid molecules have dual-targets of gp120 and gp41. In the synthesis of the hybrid molecules of CD4 mimic-SC-peptides with different lengths of linkers, two conjugating methods, Cu-catalyzed azide-alkyne cycloaddition and direct cysteine alkylation, were performed. The latter reaction caused simpler operation procedures and higher synthetic yields than the former. The synthesized hybrid molecules of CD4 mimic-SC22EK have significantly higher anti-HIV activity than each sole agent. The present data should be useful in the future design of anti-HIV agents as dual-target entry inhibitors.
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Affiliation(s)
- Rongyi Wang
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Kohei Tsuji
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Takuya Kobayakawa
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Yishan Liu
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Kazuhisa Yoshimura
- Institute of Public Health, Bureau of Social Welfare and Public Health, Tokyo Metropolitan Government, Shinjuku-ku, Tokyo 169-0073, Japan
| | - Shuzo Matsushita
- The Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 860-0811, Japan
| | - Shigeyoshi Harada
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
| | - Hirokazu Tamamura
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
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20
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Computational epitope mapping of class I fusion proteins using low complexity supervised learning methods. PLoS Comput Biol 2022; 18:e1010230. [DOI: 10.1371/journal.pcbi.1010230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 12/19/2022] [Accepted: 11/24/2022] [Indexed: 12/13/2022] Open
Abstract
Antibody epitope mapping of viral proteins plays a vital role in understanding immune system mechanisms of protection. In the case of class I viral fusion proteins, recent advances in cryo-electron microscopy and protein stabilization techniques have highlighted the importance of cryptic or ‘alternative’ conformations that expose epitopes targeted by potent neutralizing antibodies. Thorough epitope mapping of such metastable conformations is difficult but is critical for understanding sites of vulnerability in class I fusion proteins that occur as transient conformational states during viral attachment and fusion. We introduce a novel method Accelerated class I fusion protein Epitope Mapping (AxIEM) that accounts for fusion protein flexibility to improve out-of-sample prediction of discontinuous antibody epitopes. Harnessing data from previous experimental epitope mapping efforts of several class I fusion proteins, we demonstrate that accuracy of epitope prediction depends on residue environment and allows for the prediction of conformation-dependent antibody target residues. We also show that AxIEM can identify common epitopes and provide structural insights for the development and rational design of vaccines.
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21
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Residues L55 and W69 of Tva Mediate Entry of Subgroup A Avian Leukosis Virus. J Virol 2022; 96:e0067822. [PMID: 36069550 PMCID: PMC9517704 DOI: 10.1128/jvi.00678-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The receptor of the subgroup A avian leukosis virus (ALV-A) in chicken is Tva, which is the homologous protein of human CD320 (huCD320), contains a low-density lipoprotein (LDL-A) module and is involved in the uptake of transcobalamin bound vitamin B12/cobalamin (Cbl). To map the functional determinants of Tva responsible for ALV-A receptor activity, a series of chimeric receptors were created by swapping the LDL-A module fragments between huCD320 and Tva. These chimeric receptors were then used for virus entry and binding assays to map the minimal ALV-A functional domain of Tva. The results showed that Tva residues 49 to 71 constituted the minimal functional domain that directly interacted with the ALV-A gp85 protein to mediate ALV-A entry. Single-residue substitution analysis revealed that L55 and W69, which were spatially adjacent on the surface of the Tva structure, were key residues that mediate ALV-A entry. Structural alignment results indicated that L55 and W69 substitutions did not affect the Tva protein structure but abolished the interaction force between Tva and gp85. Furthermore, substituting the corresponding residues of huCD320 with L55 and W69 of Tva converted huCD320 into a functional receptor of ALV-A. Importantly, soluble huCD320 harboring Tva L55 and W69 blocked ALV-A entry. Finally, we constructed a Tva gene-edited cell line with L55R and W69L substitutions that could fully resist ALV-A entry, while Cbl uptake was not affected. Collectively, our findings suggested that amino acids L55 and W69 of Tva were key for mediating virus entry. IMPORTANCE Retroviruses bind to cellular receptors through their envelope proteins, which is a crucial step in infection. While most retroviruses require two receptors for entry, ALV-A requires only one. Various Tva alleles conferring resistance to ALV-A, including Tvar1 (C40W substitution), Tvar2 (frame-shifting four-nucleotide insertion), Tvar3, Tvar4, Tvar5, and Tvar6 (deletion in the first intron), are known. However, the detailed entry mechanism of ALV-A in chickens remains to be explored. We demonstrated that Tva residues L55 and W69 were key for ALV-A entry and were important for correct interaction with ALV-A gp85. Soluble Tva and huCD320 harboring the Tva residues L55 and W69 effectively blocked ALV-A infection. Additionally, we constructed gene-edited cell lines targeting these two amino acids, which completely restricted ALV-A entry without affecting Cbl uptake. These findings contribute to a better understanding of the infection mechanism of ALV-A and provided novel insights into the prevention and control of ALV-A.
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22
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Saunders KO, Edwards RJ, Tilahun K, Manne K, Lu X, Cain DW, Wiehe K, Williams WB, Mansouri K, Hernandez GE, Sutherland L, Scearce R, Parks R, Barr M, DeMarco T, Eater CM, Eaton A, Morton G, Mildenberg B, Wang Y, Rountree RW, Tomai MA, Fox CB, Moody MA, Alam SM, Santra S, Lewis MG, Denny TN, Shaw GM, Montefiori DC, Acharya P, Haynes BF. Stabilized HIV-1 envelope immunization induces neutralizing antibodies to the CD4bs and protects macaques against mucosal infection. Sci Transl Med 2022; 14:eabo5598. [PMID: 36070369 PMCID: PMC10034035 DOI: 10.1126/scitranslmed.abo5598] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A successful HIV-1 vaccine will require induction of a polyclonal neutralizing antibody (nAb) response, yet vaccine-mediated induction of such a response in primates remains a challenge. We found that a stabilized HIV-1 CH505 envelope (Env) trimer formulated with a Toll-like receptor 7/8 agonist induced potent HIV-1 polyclonal nAbs that correlated with protection from homologous simian-human immunodeficiency virus (SHIV) infection. The serum dilution that neutralized 50% of virus replication (ID50 titer) required to protect 90% of macaques was 1:364 against the challenge virus grown in primary rhesus CD4+ T cells. Structural analyses of vaccine-induced nAbs demonstrated targeting of the Env CD4 binding site or the N156 glycan and the third variable loop base. Autologous nAb specificities similar to those elicited in macaques by vaccination were isolated from the human living with HIV from which the CH505 Env immunogen was derived. CH505 viral isolates were isolated that mutated the V1 to escape both the infection-induced and vaccine-induced antibodies. These results define the specificities of a vaccine-induced nAb response and the protective titers of HIV-1 vaccine-induced nAbs required to protect nonhuman primates from low-dose mucosal challenge by SHIVs bearing a primary transmitted/founder Env.
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Affiliation(s)
- Kevin O. Saunders
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Surgery, Duke University Medical Center; Durham, NC 27710
- Department of Microbiology and Molecular Genetics, Duke University Medical Center; Durham, NC 27710
- Department of Immunology, Duke University Medical Center; Durham, NC, 27710, USA
| | - Robert J. Edwards
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Kedamawit Tilahun
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Kartik Manne
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Xiaozhi Lu
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Derek W. Cain
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Wilton B. Williams
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Surgery, Duke University Medical Center; Durham, NC 27710
- Department of Immunology, Duke University Medical Center; Durham, NC, 27710, USA
| | - Katayoun Mansouri
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Giovanna E. Hernandez
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Laura Sutherland
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Richard Scearce
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Maggie Barr
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Todd DeMarco
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Chloe M. Eater
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Amanda Eaton
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Surgery, Duke University Medical Center; Durham, NC 27710
| | | | | | - Yunfei Wang
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - R. Wes Rountree
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Mark A. Tomai
- 3M Corporate Research Materials Lab, 3M Company; St. Paul, MN, 55144, USA
| | | | - M. Anthony Moody
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Pediatrics, Duke University Medical Center; Durham, NC, 27710, USA
| | - S. Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - Sampa Santra
- Beth Israel Deaconess Medical Center; Boston, MA, 02215, USA
| | | | - Thomas N. Denny
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
| | - George M. Shaw
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, PA, 19104, USA
| | - David C. Montefiori
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Surgery, Duke University Medical Center; Durham, NC 27710
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Surgery, Duke University Medical Center; Durham, NC 27710
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University Medical Center; Durham, NC 27710
- Department of Immunology, Duke University Medical Center; Durham, NC, 27710, USA
- Department of Medicine, Duke University Medical Center; Durham, NC, 27710, USA
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23
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Tumba NL, Owen GR, Killick MA, Papathanasopoulos MA. Immunization with HIV-1 trimeric SOSIP.664 BG505 or Founder Virus C (FVCEnv) covalently complexed to two-domain CD4S60C elicits cross-clade neutralizing antibodies in New Zealand white rabbits. Vaccine X 2022; 12:100222. [PMID: 36262212 PMCID: PMC9573916 DOI: 10.1016/j.jvacx.2022.100222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 09/21/2022] [Accepted: 09/28/2022] [Indexed: 11/22/2022] Open
Abstract
Background: An ongoing challenge in HIV-1 vaccine research is finding a novel HIV-1 envelope glycoprotein (Env)-based immunogen that elicits broadly cross-neutralizing antibodies (bnAbs) without requiring complex sequential immunization regimens to drive the required antibody affinity maturation. Previous vaccination studies have shown monomeric Env and Env trimers which contain the GCN4 leucine zipper trimerization domain and are covalently bound to the first two domains of CD4 (2dCD4S60C) generate potent bnAbs in small animals. Since SOSIP.664 trimers are considered the most accurate, conformationally intact representation of HIV-1 Env generated to date, this study further evaluated the immunogenicity of SOSIP.664 HIV Env trimers (the well characterized BG505 and FVCEnv) covalently complexed to 2dCD4S60C. Methods: Recombinant BG505 SOSIP.664 and FVCEnv SOSIP.664 were expressed in mammalian cells, purified, covalently coupled to 2dCD4S60C and antigenically characterized for their interaction with HIV-1 bnAbs. The immunogenicity of BG505 SOSIP.664-2dCD4S60C and FVCEnv SOSIP.664-2dCD4S60C was investigated in New Zealand white rabbits and compared to unliganded FVCEnv and 2dCD4S60C. Rabbit sera were tested for the presence of neutralizing antibodies against a panel of 17 pseudoviruses. Results: Both BG505 SOSIP.664-2dCD4S60C and FVCEnv SOSIP.664-2dCD4S60C elicited a potent, HIV-specific response in rabbits with antibodies having considerable potency and breadth (70.5% and 76%, respectively) when tested against a global panel of 17 pseudoviruses mainly composed of harder-to-neutralize multiple clade tier-2 pseudoviruses. Conclusion: BG505 SOSIP.664-2dCD4S60C and FVCEnvSOSIP.664-2dCD4S60C are highly immunogenic and elicit potent, broadly neutralizing antibodies, the extent of which has never been reported previously for SOSIP.664 trimers. Adding to our previous results, the ability to consistently elicit these types of potent, cross-neutralizing antibody responses is dependent on novel epitopes exposed following the covalent binding of Env (independent of sequence and conformation) to 2dCD4S60C. These findings justify further investment into research exploring modified open, CD4-bound Env conformations as novel vaccine immunogens.
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Enhancement of CD4 Binding, Host Cell Entry, and Sensitivity to CD4bs Antibody Inhibition Conferred by a Natural but Rare Polymorphism in the HIV-1 Envelope. J Virol 2022; 96:e0185121. [PMID: 35862673 PMCID: PMC9327689 DOI: 10.1128/jvi.01851-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A rare but natural polymorphism in the HIV-1 envelope (Env) glycoprotein, lysine at position 425 was selected as a mutation conferring resistance to maraviroc (MVC) in vitro. N425K has not been identified in HIV-infected individuals failing an MVC-based treatment. This study reports that the rare K425 polymorphism in an HIV-1 subtype A Env has increased affinity for CD4, resulting in faster host cell entry kinetics and the ability to scavenge for low cell surface expression of CD4 to mediate entry. Whereas the subtype A wild-type isolate-74 Env (N425) is inhibited by soluble (s) CD4, HIV-1 with K425 A74 Env shows enhanced infection and the ability to infect CCR5+ cells when pretreated with sCD4. Upon adding K425 or N425 HIV-1 to CD4+/CCR5+ cells along with RANTES/CCL3, only K425 HIV-1 was able to infect cells when CCR5 recycled/returned to the cell surface at 12 h post-treatment. These findings suggest that upon binding to CD4, K425 Env may maintain a stable State 2 "open" conformation capable of engaging CCR5 for entry. Only K425 was significantly more sensitivity than wild-type N425 A74 to inhibition by the CD4 binding site (bs) compound, BMS-806, the CD4bs antibody, VRC01 and N6, and the single-chain CD4i antibody, SCm9. K425 A74 was also capable of activating B cells expressing the VRC01 surface immunoglobulin. In summary, despite increased replicative fitness, we propose that K425 HIV-1 may be counterselected within infected individuals if K425 HIV-1 is rapidly eliminated by CD4bs-neutralizing antibodies. IMPORTANCE Typically, a natural amino acid polymorphism is found as the wild-type sequence in the HIV-1 population if it provides a selective advantage to the virus. The natural K425 polymorphism in HIV-1 Env results in higher host cell entry efficiency and greater replicative fitness by virtue of its high binding affinity to CD4. The studies presented herein suggest that the rare K425 HIV-1, compared to the common N425 HIV-1, may be more sensitive to inhibition by CD4bs-neutralizing antibodies (i.e., antibodies that bind to the CD4 binding pocket on the HIV-1 envelope glycoprotein). If CD4bs antibodies did emerge in an infected individual, the K425 HIV-1 may be hypersensitive to inhibition, and thus this K425 virus variant may be removed from the HIV-1 swarm despite its higher replication fitness. Studies are now underway to determine whether addition of the K425 polymorphism into the Envelope-based HIV-1 vaccines could enhance protective immunity.
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Comparing methods for immobilizing HIV-1 SOSIPs in ELISAs that evaluate antibody binding. Sci Rep 2022; 12:11172. [PMID: 35778473 PMCID: PMC9247892 DOI: 10.1038/s41598-022-15506-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/24/2022] [Indexed: 11/09/2022] Open
Abstract
Enzyme-linked immunosorbent assays (ELISAs) are used to evaluate binding of broadly neutralizing antibodies (bNAbs) and polyclonal sera to native-like HIV-1 Env SOSIPs. Methods for immobilizing SOSIPs on plates differ, which can lead to variable or, in some cases, misleading results. Three methods used to immobilize SOSIPs were compared to determine how antigen immobilization methods affect Env conformation and ELISA results. HIV-1 SOSIPs were directly coated on polystyrene plates, captured by a monoclonal antibody against a C-terminal affinity tag, or randomly biotinylated and coated on a streptavidin plate. Binding of bNAbs with known epitopes were compared for each immobilization method. Binding of bNAbs targeting the V1V2, V3, CD4 binding site, and gp120/gp41 interface was comparable for all antigen immobilization methods. However, directly coated HIV-1 SOSIP ELISAs showed detectable binding of 17b, a CD4-induced antibody that binds a V3 epitope that is concealed on closed prefusion Env trimers in the absence of added CD4, whereas antibody-immobilized and randomly biotinylated Env-coated ELISAs did not show detectable binding of 17b in the absence of CD4. We conclude direct coating of HIV-1 SOSIPs on ELISA plates can result in exposure of CD4-induced antibody epitopes, suggesting disruption of Env structure and exposure of epitopes that are hidden in the closed, prefusion trimer.
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26
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Mostashari-Rad T, Claes S, Schols D, Shirvani P, Fassihi A. New 2-alkylthio-1-benzylimidazole-5-carboxylic acid derivatives targeting gp41: design, synthesis and in vitro anti-HIV activity evaluation. Curr HIV Res 2022; 20:CHR-EPUB-124859. [PMID: 35770403 DOI: 10.2174/1570162x20666220628154901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/05/2022] [Accepted: 05/05/2022] [Indexed: 11/22/2022]
Abstract
Background Although current available medications have increased the quality of life in HIV-infected patients, there are still some shortcomings in HIV treatment arising from viral resistance, drug side effects and high cost of medication. Therefore, there is an urgent need for some suitable HIV inhibitors with different mechanisms of action. Gp41, located on the HIV cell surface, plays an important role in the fusion of viral and host cell membranes. With the same structure in different HIV strains, gp41 seems to be a promising target for developing novel HIV fusion inhibitors. Objective Based on the essential structural elements of gp41 inhibitors, two series of compounds were prepared and their inhibitory effect on HIV cell growth was investigated. Compared to the known small-molecule gp41 inhibitors, 2-Alkylthio-1-benzylimidazole-5-carboxylic acid (series I) and (E)-4-{[5-(((1-benzyl-1H-1,2,3-triazol-4-yl)methoxyimino)methyl)-2-(alkylthio)-1H-imidazol-1-yl]methyl}benzoic acid derivatives (series II) had more flexible skeleton with extra moieties interacting with the gp41 key residues. Method In silico drug design approaches including molecular docking and molecular dynamics simulations were employed to design these novel compounds prior to preparation. The designed compounds exhibited proper chemical interactions and stable complexes with gp41. Then, the selected candidates were efficiently synthesized, and their anti-HIV-1 and anti-HIV-2 activities, as well as their cellular cytotoxicity in MT-4 cells were determined. Results None of the compounds belonging to the series I were active against HIV-1 and HIV-2 replication in cell cultures, and most of the compounds in series II exhibited significant cytotoxicity against MT-4 cells in low micro molar concentrations. Conclusion The smaller molecular structures of the compounds in series I might be responsible for their poor anti-HIV effects. The high toxicity of the series II compounds on the host cell makes it impossible to assess their anti-HIV activities.
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Affiliation(s)
- Tahereh Mostashari-Rad
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sandra Claes
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Dominique Schols
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Pouria Shirvani
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Afshin Fassihi
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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27
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Hodge EA, Naika GS, Kephart SM, Nguyen A, Zhu R, Benhaim MA, Guo W, Moore JP, Hu SL, Sanders RW, Lee KK. Structural dynamics reveal isolate-specific differences at neutralization epitopes on HIV Env. iScience 2022; 25:104449. [PMID: 35677643 PMCID: PMC9167985 DOI: 10.1016/j.isci.2022.104449] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/25/2022] [Accepted: 05/17/2022] [Indexed: 11/19/2022] Open
Abstract
The envelope glycoprotein (Env) is the sole target for neutralizing antibodies against HIV and the most rapidly evolving, variable part of the virus. High-resolution structures of Env trimers captured in the pre-fusion, closed conformation have revealed a high degree of structural similarity across diverse isolates. Biophysical data, however, indicate that Env is highly dynamic, and the level of dynamics and conformational sampling is believed to vary dramatically between HIV isolates. Dynamic differences likely influence neutralization sensitivity, receptor activation, and overall trimer stability. Here, using hydrogen/deuterium-exchange mass spectrometry (HDX-MS), we have mapped local dynamics across native-like Env SOSIP trimers from diverse isolates. We show that significant differences in epitope order are observed across most sites targeted by broadly neutralizing antibodies. We also observe isolate-dependent conformational switching that occurs over a broad range of timescales. Lastly, we report that hyper-stabilizing mutations that dampen dynamics in some isolates have little effect on others.
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Affiliation(s)
- Edgar A. Hodge
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Gajendra S. Naika
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Sally M. Kephart
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Adam Nguyen
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
- Biological Physics, Structure and Design Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Richard Zhu
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Mark A. Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Wenjin Guo
- Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA
| | - John P. Moore
- Division of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Shiu-Lok Hu
- Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA
| | - Rogier W. Sanders
- Division of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Kelly K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
- Biological Physics, Structure and Design Graduate Program, University of Washington, Seattle, WA 98195, USA
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28
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Schriek AI, van Haaren MM, Poniman M, Dekkers G, Bentlage AEH, Grobben M, Vidarsson G, Sanders RW, Verrips T, Geijtenbeek TBH, Heukers R, Kootstra NA, de Taeye SW, van Gils MJ. Anti-HIV-1 Nanobody-IgG1 Constructs With Improved Neutralization Potency and the Ability to Mediate Fc Effector Functions. Front Immunol 2022; 13:893648. [PMID: 35651621 PMCID: PMC9150821 DOI: 10.3389/fimmu.2022.893648] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/13/2022] [Indexed: 11/13/2022] Open
Abstract
The most effective treatment for HIV-1, antiretroviral therapy, suppresses viral replication and averts the disease from progression. Nonetheless, there is a need for alternative treatments as it requires daily administration with the possibility of side effects and occurrence of drug resistance. Broadly neutralizing antibodies or nanobodies targeting the HIV-1 envelope glycoprotein are explored as alternative treatment, since they mediate viral suppression and contribute to the elimination of virus-infected cells. Besides neutralization potency and breadth, Fc-mediated effector functions of bNAbs also contribute to the in vivo efficacy. In this study multivalent J3, 2E7 and 1F10 anti-HIV-1 broadly neutralizing nanobodies were generated to improve neutralization potency and IgG1 Fc fusion was utilized to gain Fc-mediated effector functions. Bivalent and trivalent nanobodies, coupled using long glycine-serine linkers, showed increased binding to the HIV-1 Env and enhanced neutralization potency compared to the monovalent variant. Fusion of an IgG1 Fc domain to J3 improved neutralization potency compared to the J3-bihead and restored Fc-mediated effector functions such as antibody-dependent cellular phagocytosis and trogocytosis, and natural killer cell activation. Due to their neutralization breadth and potency and their ability to induce effector functions these nanobody-IgG1 constructs may prove to be valuable towards alternative HIV-1 therapies.
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Affiliation(s)
- Angela I Schriek
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | - Marlies M van Haaren
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | - Meliawati Poniman
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | | | - Arthur E H Bentlage
- Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Marloes Grobben
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Rogier W Sanders
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands.,Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY, United States
| | - Theo Verrips
- Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, Netherlands.,VerLin BV, Utrecht, Netherlands
| | - Teunis B H Geijtenbeek
- Department of Experimental Immunology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | | | - Neeltje A Kootstra
- Department of Experimental Immunology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | - Steven W de Taeye
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
| | - Marit J van Gils
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands
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29
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Schapiro HM, Khasnis MD, Ahn K, Karagiaridi A, Hayden S, Cilento ME, Root MJ. Regulation of epitope exposure in the gp41 membrane-proximal external region through interactions at the apex of HIV-1 Env. PLoS Pathog 2022; 18:e1010531. [PMID: 35584191 PMCID: PMC9154124 DOI: 10.1371/journal.ppat.1010531] [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: 10/21/2021] [Revised: 05/31/2022] [Accepted: 04/18/2022] [Indexed: 11/19/2022] Open
Abstract
Glycoprotein Env of human immunodeficiency virus type 1 (HIV-1) mediates viral entry through membrane fusion. Composed of gp120 and gp41 subunits arranged as a trimer-of-heterodimers, Env adopts a metastable, highly dynamic conformation on the virion surface. This structural plasticity limits the temporospatial exposure of many highly conserved, neutralizing epitopes, contributing to the difficulty in developing effective HIV-1 vaccines. Here, we employed antibody neutralization of HIV-1 infectivity to investigate how inter- and intra-gp120 interactions mediated by variable loops V1/V2 and V3 at the Env apex regulate accessibility of the gp41 membrane-proximal external region (MPER) at the Env base. Swapping the V3 loop from EnvSF162 into the EnvHXB2 background shifted MPER exposure from the prefusogenic state to a functional intermediate conformation that was distinct from the prehairpin-intermediate state sensitive to gp41-targeted fusion inhibitors. The V3-loop swap had a profound impact on global protein dynamics, biasing the equilibrium to a closed conformation resistant to most anti-gp120 antibodies, stabilizing the protein to both cold- and soluble CD4-induced Env inactivation, and increasing the CD4 requirements for viral entry. Further dissection of the EnvHXB2 V3 loop revealed that residue 306 uniquely modulated epitope exposure and trimer stability. The R306S substitution substantially decreased sensitivity to antibodies targeting the gp41 MPER and, surprisingly, the gp120 V3-loop crown (residues 312–315), but had only modest effects on exposure of intervening gp120 epitopes. Furthermore, the point mutation reduced soluble CD4-induced inactivation, but had no impact on cold inactivation. The residue appeared to exert its effects by electrostatically modifying the strength of intra-subunit interactions between the V1/V2 and V3 loops. The distinct patterns of neutralization and stability pointed to a novel prefusogenic Env conformation along the receptor activation pathway and suggested that apical Env-regulation of gp41 MPER exposure can be decoupled from much of the dynamics of gp120 subunits. Surface glycoprotein Env is the main target for neutralizing antibodies elicited by HIV-1 vaccines. Env spontaneously fluctuates among different structures, limiting exposure of many attractive antibody-binding epitopes and, thereby, confounding vaccine development. To characterize these fluctuations, we examined how exposure of the MPER epitope found at the base of Env is regulated by interactions of the V3 loop located in the apex. Starting with an extremely flexible Env with a readily-exposed MPER, we identified two alterations that substantially restricted antibody access to the epitope. The first, a wholesale swap of V3 loops between HIV-1 strains, energetically stabilized Env in a closed structure that restricted access to antibodies throughout the protein. The second, a point mutation that altered V3-loop charge, specifically destabilized the MPER-exposed conformation but had minimal impact on antibody access to Env regions in between the apex and base. The results indicate that MPER exposure is not explicitly tied to the dynamics of Env regions between the apex and base and suggest a new structural fluctuation during Env activation.
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Affiliation(s)
- Hannah M. Schapiro
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Mukta D. Khasnis
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Koree Ahn
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Alexandra Karagiaridi
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Stephanie Hayden
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Maria E. Cilento
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Michael J. Root
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
- * E-mail:
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30
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Abstract
The HIV Env glycoprotein is the surface glycoprotein responsible for viral entry into CD4+ immune cells. During infection, Env also serves as a primary target for antibody responses, which are robust but unable to control virus replication. Immune evasion by HIV-1 Env appears to employ complex mechanisms to regulate what antigenic states are presented to the immune system. Immunodominant features appear to be distinct from epitopes that interfere with Env functions in mediating infection. Further, cell-cell transmission studies indicate that vulnerable conformational states are additionally hidden from recognition on infected cells, even though the presence of Env at the cell surface is required for viral infection through the virological synapse. Cell-cell infection studies support that Env on infected cells is presented in distinct conformations from that on virus particles. Here we review data regarding the regulation of conformational states of Env and assess how regulated sorting of Env within the infected cell may underlie mechanisms to distinguish Env on the surface of virus particles versus Env on the surface of infected cells. These mechanisms may allow infected cells to avoid opsonization, providing cell-to-cell infection by HIV with a selective advantage during evolution within an infected individual. Understanding how distinct Env conformations are presented on cells versus viruses may be essential to designing effective vaccine approaches and therapeutic strategies to clear infected cell reservoirs.
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Affiliation(s)
- Connie Zhao
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hongru Li
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Talia H. Swartz
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin K. Chen
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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31
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Yang Z, Dam KMA, Bridges MD, Hoffmann MAG, DeLaitsch AT, Gristick HB, Escolano A, Gautam R, Martin MA, Nussenzweig MC, Hubbell WL, Bjorkman PJ. Neutralizing antibodies induced in immunized macaques recognize the CD4-binding site on an occluded-open HIV-1 envelope trimer. Nat Commun 2022; 13:732. [PMID: 35136084 PMCID: PMC8826976 DOI: 10.1038/s41467-022-28424-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/24/2022] [Indexed: 11/09/2022] Open
Abstract
Broadly-neutralizing antibodies (bNAbs) against HIV-1 Env can protect from infection. We characterize Ab1303 and Ab1573, heterologously-neutralizing CD4-binding site (CD4bs) antibodies, isolated from sequentially-immunized macaques. Ab1303/Ab1573 binding is observed only when Env trimers are not constrained in the closed, prefusion conformation. Fab-Env cryo-EM structures show that both antibodies recognize the CD4bs on Env trimer with an ‘occluded-open’ conformation between closed, as targeted by bNAbs, and fully-open, as recognized by CD4. The occluded-open Env trimer conformation includes outwardly-rotated gp120 subunits, but unlike CD4-bound Envs, does not exhibit V1V2 displacement, 4-stranded gp120 bridging sheet, or co-receptor binding site exposure. Inter-protomer distances within trimers measured by double electron-electron resonance spectroscopy suggest an equilibrium between occluded-open and closed Env conformations, consistent with Ab1303/Ab1573 binding stabilizing an existing conformation. Studies of Ab1303/Ab1573 demonstrate that CD4bs neutralizing antibodies that bind open Env trimers can be raised by immunization, thereby informing immunogen design and antibody therapeutic efforts. Neutralizing antibodies (bNAbs) against HIV-1 are exclusively directed against the viral envelope protein (Env) and mainly target Env in a closed, prefusion state. Here, Yang et al. structurally characterize two heterologously-neutralizing CD4-binding site (CD4bs) antibodies isolated from sequentially immunized macaques, and show that these antibodies recognize the CD4bs on Env trimers in an „occluded-open‟ conformation between closed, as targeted by bNAbs, and fully-open, as recognized by CD4.
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Affiliation(s)
- Zhi Yang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Kim-Marie A Dam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Michael D Bridges
- Jules Stein Eye Institute, University of California, Los Angeles, CA, USA.,Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Magnus A G Hoffmann
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Andrew T DeLaitsch
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Harry B Gristick
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Amelia Escolano
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY, USA
| | - Rajeev Gautam
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Malcolm A Martin
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY, USA.,Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Wayne L Hubbell
- Jules Stein Eye Institute, University of California, Los Angeles, CA, USA.,Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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32
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Griffith SA, McCoy LE. To bnAb or Not to bnAb: Defining Broadly Neutralising Antibodies Against HIV-1. Front Immunol 2021; 12:708227. [PMID: 34737737 PMCID: PMC8560739 DOI: 10.3389/fimmu.2021.708227] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 09/30/2021] [Indexed: 12/13/2022] Open
Abstract
Since their discovery, antibodies capable of broad neutralisation have been at the forefront of HIV-1 research and are of particular interest due to in vivo passive transfer studies demonstrating their potential to provide protection. Currently an exact definition of what is required for a monoclonal antibody to be classed as a broadly neutralising antibody (bnAb) has not yet been established. This has led to hundreds of antibodies with varying neutralisation breadth being studied and has given insight into antibody maturation pathways and epitopes targeted. However, even with this knowledge, immunisation studies and vaccination trials to date have had limited success in eliciting antibodies with neutralisation breadth. For this reason there is a growing need to identify factors specifically associated with bnAb development, yet to do this a set of criteria is necessary to distinguish bnAbs from non-bnAbs. This review aims to define what it means to be a HIV-1 bnAb by comparing neutralisation breadth, genetic features and epitopes of bnAbs, and in the process highlights the challenges of comparing the array of antibodies that have been isolated over the years.
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Affiliation(s)
- Sarah A Griffith
- Division of Infection and Immunity, Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Laura E McCoy
- Division of Infection and Immunity, Institute of Immunity and Transplantation, University College London, London, United Kingdom
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33
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Carlon-Andres I, Malinauskas T, Padilla-Parra S. Structure dynamics of HIV-1 Env trimers on native virions engaged with living T cells. Commun Biol 2021; 4:1228. [PMID: 34707229 PMCID: PMC8551276 DOI: 10.1038/s42003-021-02658-1] [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: 12/23/2020] [Accepted: 09/09/2021] [Indexed: 11/29/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) mediates viral entry into the host cell. Although the highly dynamic nature of Env intramolecular conformations has been shown with single molecule spectroscopy in vitro, the bona fide Env intra- and intermolecular mechanics when engaged with live T cells remains unknown. We used two photon fast fluorescence lifetime imaging detection of single-molecule Förster Resonance Energy Transfer occurring between fluorescent labels on HIV-1 Env on native virions. Our observations reveal Env dynamics at two levels: transitions between different intramolecular conformations and intermolecular interactions between Env within the viral membrane. Furthermore, we show that three broad neutralizing anti-Env antibodies directed to different epitopes restrict Env intramolecular dynamics and interactions between adjacent Env molecules when engaged with living T cells. Importantly, our results show that Env-Env interactions depend on efficient virus maturation, and that is disrupted upon binding of Env to CD4 or by neutralizing antibodies. Thus, this study illuminates how different intramolecular conformations and distribution of Env molecules mediate HIV-1 Env-T cell interactions in real time and therefore might control immune evasion.
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Affiliation(s)
- Irene Carlon-Andres
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London, United Kingdom.
- Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Sergi Padilla-Parra
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London, United Kingdom.
- Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
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34
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Abernathy ME, Gristick HB, Vielmetter J, Keeffe JR, Gnanapragasam PNP, Lee YE, Escolano A, Gautam R, Seaman MS, Martin MA, Nussenzweig MC, Bjorkman PJ. Antibody elicited by HIV-1 immunogen vaccination in macaques displaces Env fusion peptide and destroys a neutralizing epitope. NPJ Vaccines 2021; 6:126. [PMID: 34697307 PMCID: PMC8545924 DOI: 10.1038/s41541-021-00387-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 10/01/2021] [Indexed: 11/09/2022] Open
Abstract
HIV-1 vaccine design aims to develop an immunogen that elicits broadly neutralizing antibodies against a desired epitope, while eliminating responses to off-target regions of HIV-1 Env. We report characterization of Ab1245, an off-target antibody against the Env gp120-gp41 interface, from V3-glycan patch immunogen-primed and boosted macaques. A 3.7 Å cryo-EM structure of an Ab1245-Env complex reveals one Ab1245 Fab binding asymmetrically to Env trimer at the gp120-gp41 interface using its long CDRH3 to mimic regions of gp41. The mimicry includes positioning of a CDRH3 methionine into the gp41 tryptophan clasp, resulting in displacement of the fusion peptide and fusion peptide-proximal region. Despite fusion peptide displacement, Ab1245 is non-neutralizing even at high concentrations, raising the possibility that only two fusion peptides per trimer are required for viral-host membrane fusion. These structural analyses facilitate immunogen design to prevent elicitation of Ab1245-like antibodies that block neutralizing antibodies against the fusion peptide.
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Affiliation(s)
- Morgan E. Abernathy
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Harry B. Gristick
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Jost Vielmetter
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Jennifer R. Keeffe
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Priyanthi N. P. Gnanapragasam
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Yu E. Lee
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | | | - Rajeev Gautam
- grid.419681.30000 0001 2164 9667Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA ,grid.419681.30000 0001 2164 9667Present Address: Virology Branch, Basic Research Section, NIAID, NIH. 5601 Fisher’s Lane, Rockville, MD 20892 USA
| | - Michael S. Seaman
- grid.239395.70000 0000 9011 8547Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA USA
| | - Malcolm A. Martin
- grid.419681.30000 0001 2164 9667Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Michel C. Nussenzweig
- Laboratory of Molecular Immunology, New York, 10065 USA ,grid.134907.80000 0001 2166 1519Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065 USA
| | - Pamela J. Bjorkman
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
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35
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Abernathy ME, Dam KMA, Esswein SR, Jette CA, Bjorkman PJ. How Antibodies Recognize Pathogenic Viruses: Structural Correlates of Antibody Neutralization of HIV-1, SARS-CoV-2, and Zika. Viruses 2021; 13:2106. [PMID: 34696536 PMCID: PMC8537525 DOI: 10.3390/v13102106] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/09/2021] [Accepted: 10/12/2021] [Indexed: 12/15/2022] Open
Abstract
The H1N1 pandemic of 2009-2010, MERS epidemic of 2012, Ebola epidemics of 2013-2016 and 2018-2020, Zika epidemic of 2015-2016, and COVID-19 pandemic of 2019-2021, are recent examples in the long history of epidemics that demonstrate the enormous global impact of viral infection. The rapid development of safe and effective vaccines and therapeutics has proven vital to reducing morbidity and mortality from newly emerging viruses. Structural biology methods can be used to determine how antibodies elicited during infection or vaccination target viral proteins and identify viral epitopes that correlate with potent neutralization. Here we review how structural and molecular biology approaches have contributed to our understanding of antibody recognition of pathogenic viruses, specifically HIV-1, SARS-CoV-2, and Zika. Determining structural correlates of neutralization of viruses has guided the design of vaccines, monoclonal antibodies, and small molecule inhibitors in response to the global threat of viral epidemics.
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Affiliation(s)
- Morgan E. Abernathy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; (M.E.A.); (K.-M.A.D.); (C.A.J.)
| | - Kim-Marie A. Dam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; (M.E.A.); (K.-M.A.D.); (C.A.J.)
| | - Shannon R. Esswein
- David Geffen School of Medicine at University of California, Los Angeles, CA 90095, USA;
| | - Claudia A. Jette
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; (M.E.A.); (K.-M.A.D.); (C.A.J.)
| | - Pamela J. Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; (M.E.A.); (K.-M.A.D.); (C.A.J.)
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36
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Zhang S, Holmes AP, Dick A, Rashad AA, Enríquez Rodríguez L, Canziani GA, Root MJ, Chaiken IM. Altered Env conformational dynamics as a mechanism of resistance to peptide-triazole HIV-1 inactivators. Retrovirology 2021; 18:31. [PMID: 34627310 PMCID: PMC8501640 DOI: 10.1186/s12977-021-00575-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/20/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND We previously developed drug-like peptide triazoles (PTs) that target HIV-1 Envelope (Env) gp120, potently inhibit viral entry, and irreversibly inactivate virions. Here, we investigated potential mechanisms of viral escape from this promising class of HIV-1 entry inhibitors. RESULTS HIV-1 resistance to cyclic (AAR029b) and linear (KR13) PTs was obtained by dose escalation in viral passaging experiments. High-level resistance for both inhibitors developed slowly (relative to escape from gp41-targeted C-peptide inhibitor C37) by acquiring mutations in gp120 both within (Val255) and distant to (Ser143) the putative PT binding site. The similarity in the resistance profiles for AAR029b and KR13 suggests that the shared IXW pharmacophore provided the primary pressure for HIV-1 escape. In single-round infectivity studies employing recombinant virus, V255I/S143N double escape mutants reduced PT antiviral potency by 150- to 3900-fold. Curiously, the combined mutations had a much smaller impact on PT binding affinity for monomeric gp120 (four to ninefold). This binding disruption was entirely due to the V255I mutation, which generated few steric clashes with PT in molecular docking. However, this minor effect on PT affinity belied large, offsetting changes to association enthalpy and entropy. The escape mutations had negligible effect on CD4 binding and utilization during entry, but significantly altered both binding thermodynamics and inhibitory potency of the conformationally-specific, anti-CD4i antibody 17b. Moreover, the escape mutations substantially decreased gp120 shedding induced by either soluble CD4 or AAR029b. CONCLUSIONS Together, the data suggest that the escape mutations significantly modified the energetic landscape of Env's prefusogenic state, altering conformational dynamics to hinder PT-induced irreversible inactivation of Env. This work therein reveals a unique mode of virus escape for HIV-1, namely, resistance by altering the intrinsic conformational dynamics of the Env trimer.
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Affiliation(s)
- Shiyu Zhang
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Andrew P Holmes
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Alexej Dick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Adel A Rashad
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | | | - Gabriela A Canziani
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Michael J Root
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, OH, Columbus, USA.
| | - Irwin M Chaiken
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA.
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37
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HIV-1 entry: Duels between Env and host antiviral transmembrane proteins on the surface of virus particles. Curr Opin Virol 2021; 50:59-68. [PMID: 34390925 DOI: 10.1016/j.coviro.2021.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 12/18/2022]
Abstract
Human Immunodeficiency Virus type-1 (HIV-1) is the causative agent of AIDS. Its entry step is mediated by the envelope glycoprotein (Env). During the entry process, Env vastly changes its conformation. While non-liganded Env tends to have a closed structure, receptor-binding of Env opens its conformation, which leads to virus-cell membrane fusion. Single-molecule fluorescence resonance energy transfer (smFRET) imaging allows observation of these conformational changes on the virion surface. Nascent HIV-1 particles incorporate multiple host transmembrane proteins, some of which inhibit the entry process. The Env structure or its dynamics may determine the effectiveness of these antiviral mechanisms. Here, we review recent findings about the Env conformation changes on virus particles and inhibition of Env activities by virion-incorporated host transmembrane proteins.
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38
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Quaternary Interaction of the HIV-1 Envelope Trimer with CD4 and Neutralizing Antibodies. Viruses 2021; 13:v13071405. [PMID: 34372611 PMCID: PMC8310203 DOI: 10.3390/v13071405] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 11/25/2022] Open
Abstract
The entry of HIV-1 into host cells is initiated by the interaction of the viral envelope (Env) spike with the CD4 receptor. During this process, the spike undergoes a series of conformational changes that eventually lead to the exposure of the fusion peptide located at the N-terminus of the transmembrane glycoprotein, gp41. Recent structural and functional studies have provided important insights into the interaction of Env with CD4 at various stages. However, a fine elucidation of the earliest events of CD4 contact and its immediate effect on the Env conformation remains a challenge for investigation. Here, we summarize the discovery of the quaternary nature of the CD4-binding site in the HIV-1 Env and the role of quaternary contact in the functional interaction with the CD4 receptor. We propose two models for this initial contact based on the current knowledge and discuss how a better understanding of the quaternary interaction may lead to improved immunogens and antibodies targeting the CD4-binding site.
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39
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Modeling of CCR5 Recognition by HIV-1 gp120: How the Viral Protein Exploits the Conformational Plasticity of the Coreceptor. Viruses 2021; 13:v13071395. [PMID: 34372601 PMCID: PMC8310383 DOI: 10.3390/v13071395] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/05/2021] [Accepted: 07/12/2021] [Indexed: 01/14/2023] Open
Abstract
The chemokine receptor CCR5 is a key player in HIV-1 infection. The cryo-EM 3D structure of HIV-1 envelope glycoprotein (Env) subunit gp120 in complex with CD4 and CCR5 has provided important structural insights into HIV-1/host cell interaction, yet it has not explained the signaling properties of Env nor the fact that CCR5 exists in distinct forms that show distinct Env binding properties. We used classical molecular dynamics and site-directed mutagenesis to characterize the CCR5 conformations stabilized by four gp120s, from laboratory-adapted and primary HIV-1 strains, and which were previously shown to bind differentially to distinct CCR5 forms and to exhibit distinct cellular tropisms. The comparative analysis of the simulated structures reveals that the different gp120s do indeed stabilize CCR5 in different conformational ensembles. They differentially reorient extracellular loops 2 and 3 of CCR5 and thus accessibility to the transmembrane binding cavity. They also reshape this cavity differently and give rise to different positions of intracellular ends of transmembrane helices 5, 6 and 7 of the receptor and of its third intracellular loop, which may in turn influence the G protein binding region differently. These results suggest that the binding of gp120s to CCR5 may have different functional outcomes, which could result in different properties for viruses.
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40
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Ang CG, Carter E, Haftl A, Zhang S, Rashad AA, Kutzler M, Abrams CF, Chaiken IM. Peptide Triazole Thiol Irreversibly Inactivates Metastable HIV-1 Env by Accessing Conformational Triggers Intrinsic to Virus-Cell Entry. Microorganisms 2021; 9:1286. [PMID: 34204725 PMCID: PMC8231586 DOI: 10.3390/microorganisms9061286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/03/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022] Open
Abstract
KR13, a peptide triazole thiol previously established to inhibit HIV-1 infection and cause virus lysis, was evaluated by flow cytometry against JRFL Env-presenting cells to characterize induced Env and membrane transformations leading to irreversible inactivation. Transiently transfected HEK293T cells were preloaded with calcein dye, treated with KR13 or its thiol-blocked analogue KR13b, fixed, and stained for gp120 (35O22), MPER (10E8), 6-helix-bundle (NC-1), immunodominant loop (50-69), and fusion peptide (VRC34.01). KR13 induced dose-dependent transformations of Env and membrane characterized by transient poration, MPER exposure, and 6-helix-bundle formation (analogous to native fusion events), but also reduced immunodominant loop and fusion peptide exposure. Using a fusion peptide mutant (V504E), we found that KR13 transformation does not require functional fusion peptide for poration. In contrast, simultaneous treatment with fusion inhibitor T20 alongside KR13 prevented membrane poration and MPER exposure, showing that these events require 6-helix-bundle formation. Based on these results, we formulated a model for PTT-induced Env transformation portraying how, in the absence of CD4/co-receptor signaling, PTT may provide alternate means of perturbing the metastable Env-membrane complex, and inducing fusion-like transformation. In turn, the results show that such transformations are intrinsic to Env and can be diverted for irreversible inactivation of the protein complex.
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Affiliation(s)
- Charles Gotuaco Ang
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA; (E.C.); (A.H.); (S.Z.); (A.A.R.)
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19102, USA
| | - Erik Carter
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA; (E.C.); (A.H.); (S.Z.); (A.A.R.)
- Departments of Medicine and Microbiology and Immunology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA;
| | - Ann Haftl
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA; (E.C.); (A.H.); (S.Z.); (A.A.R.)
- Department of Chemistry, College of Arts and Sciences, Drexel University, Philadelphia, PA 19102, USA
| | - Shiyu Zhang
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA; (E.C.); (A.H.); (S.Z.); (A.A.R.)
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19102, USA
| | - Adel A. Rashad
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA; (E.C.); (A.H.); (S.Z.); (A.A.R.)
| | - Michele Kutzler
- Departments of Medicine and Microbiology and Immunology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA;
| | - Cameron F. Abrams
- Department of Chemical and Biological Engineering, College of Engineering, Drexel University, Philadelphia, PA 19102, USA;
| | - Irwin M. Chaiken
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA; (E.C.); (A.H.); (S.Z.); (A.A.R.)
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41
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Unleashing natural antibodies against HIV-1. Cell Host Microbe 2021; 29:849-851. [PMID: 34111390 DOI: 10.1016/j.chom.2021.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One barrier to HIV-1 eradication is the viral Env protein that is invisible to most antibodies. In this issue of Cell Host & Microbe, Rajashekar et al. (2021) remove the "invisibility cloak" from Env, make it accessible to antibodies, and demonstrate NK-mediated in vivo killing of infected cells by human plasma antibodies.
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42
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Bennett AL, Henderson R. HIV-1 Envelope Conformation, Allostery, and Dynamics. Viruses 2021; 13:852. [PMID: 34067073 PMCID: PMC8150877 DOI: 10.3390/v13050852] [Citation(s) in RCA: 3] [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: 04/07/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) mediates host cell fusion and is the primary target for HIV-1 vaccine design. The Env undergoes a series of functionally important conformational rearrangements upon engagement of its host cell receptor, CD4. As the sole target for broadly neutralizing antibodies, our understanding of these transitions plays a critical role in vaccine immunogen design. Here, we review available experimental data interrogating the HIV-1 Env conformation and detail computational efforts aimed at delineating the series of conformational changes connecting these rearrangements. These studies have provided a structural mapping of prefusion closed, open, and transition intermediate structures, the allosteric elements controlling rearrangements, and state-to-state transition dynamics. The combination of these investigations and innovations in molecular modeling set the stage for advanced studies examining rearrangements at greater spatial and temporal resolution.
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Affiliation(s)
| | - Rory Henderson
- Duke Human Vaccine Institute, Durham, NC 27710, USA;
- Department of Medicine, Duke University, Durham, NC 27710, USA
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43
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Caillat C, Guilligay D, Torralba J, Friedrich N, Nieva JL, Trkola A, Chipot CJ, Dehez FL, Weissenhorn W. Structure of HIV-1 gp41 with its membrane anchors targeted by neutralizing antibodies. eLife 2021; 10:65005. [PMID: 33871352 PMCID: PMC8084527 DOI: 10.7554/elife.65005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 04/18/2021] [Indexed: 12/19/2022] Open
Abstract
The HIV-1 gp120/gp41 trimer undergoes a series of conformational changes in order to catalyze gp41-induced fusion of viral and cellular membranes. Here, we present the crystal structure of gp41 locked in a fusion intermediate state by an MPER-specific neutralizing antibody. The structure illustrates the conformational plasticity of the six membrane anchors arranged asymmetrically with the fusion peptides and the transmembrane regions pointing into different directions. Hinge regions located adjacent to the fusion peptide and the transmembrane region facilitate the conformational flexibility that allows high-affinity binding of broadly neutralizing anti-MPER antibodies. Molecular dynamics simulation of the MPER Ab-stabilized gp41 conformation reveals a possible transition pathway into the final post-fusion conformation with the central fusion peptides forming a hydrophobic core with flanking transmembrane regions. This suggests that MPER-specific broadly neutralizing antibodies can block final steps of refolding of the fusion peptide and the transmembrane region, which is required for completing membrane fusion.
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Affiliation(s)
- Christophe Caillat
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Delphine Guilligay
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Johana Torralba
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Nikolas Friedrich
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Jose L Nieva
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Alexandra Trkola
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Christophe J Chipot
- Laboratoire de Physique et Chimie Théoriques (LPCT), University of Lorraine, Vandoeuvre-lès-Nancy, France.,Laboratoire International Associé, CNRS and University of Illinois at Urbana-Champaign, Vandoeuvre-lès-Nancy, France.,Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States
| | - François L Dehez
- Laboratoire de Physique et Chimie Théoriques (LPCT), University of Lorraine, Vandoeuvre-lès-Nancy, France.,Laboratoire International Associé, CNRS and University of Illinois at Urbana-Champaign, Vandoeuvre-lès-Nancy, France
| | - Winfried Weissenhorn
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
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44
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Jette CA, Barnes CO, Kirk SM, Melillo B, Smith AB, Bjorkman PJ. Cryo-EM structures of HIV-1 trimer bound to CD4-mimetics BNM-III-170 and M48U1 adopt a CD4-bound open conformation. Nat Commun 2021; 12:1950. [PMID: 33782388 PMCID: PMC8007822 DOI: 10.1038/s41467-021-21816-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 02/11/2021] [Indexed: 02/01/2023] Open
Abstract
Human immunodeficiency virus-1 (HIV-1), the causative agent of AIDS, impacts millions of people. Entry into target cells is mediated by the HIV-1 envelope (Env) glycoprotein interacting with host receptor CD4, which triggers conformational changes allowing binding to a coreceptor and subsequent membrane fusion. Small molecule or peptide CD4-mimetic drugs mimic CD4's Phe43 interaction with Env by inserting into the conserved Phe43 pocket on Env subunit gp120. Here, we present single-particle cryo-EM structures of CD4-mimetics BNM-III-170 and M48U1 bound to a BG505 native-like Env trimer plus the CD4-induced antibody 17b at 3.7 Å and 3.9 Å resolution, respectively. CD4-mimetic-bound BG505 exhibits canonical CD4-induced conformational changes including trimer opening, formation of the 4-stranded gp120 bridging sheet, displacement of the V1V2 loop, and formation of a compact and elongated gp41 HR1C helical bundle. We conclude that CD4-induced structural changes on both gp120 and gp41 Env subunits are induced by binding to the gp120 Phe43 pocket.
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Affiliation(s)
- Claudia A. Jette
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA USA
| | - Christopher O. Barnes
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA USA
| | - Sharon M. Kirk
- grid.25879.310000 0004 1936 8972Department of Chemistry, University of Pennsylvania, Philadelphia, PA USA
| | - Bruno Melillo
- grid.25879.310000 0004 1936 8972Department of Chemistry, University of Pennsylvania, Philadelphia, PA USA
| | - Amos B. Smith
- grid.25879.310000 0004 1936 8972Department of Chemistry, University of Pennsylvania, Philadelphia, PA USA
| | - Pamela J. Bjorkman
- grid.20861.3d0000000107068890Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA USA
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45
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Lu M. Single-Molecule FRET Imaging of Virus Spike-Host Interactions. Viruses 2021; 13:v13020332. [PMID: 33669922 PMCID: PMC7924862 DOI: 10.3390/v13020332] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 02/07/2023] Open
Abstract
As a major surface glycoprotein of enveloped viruses, the virus spike protein is a primary target for vaccines and anti-viral treatments. Current vaccines aiming at controlling the COVID-19 pandemic are mostly directed against the SARS-CoV-2 spike protein. To promote virus entry and facilitate immune evasion, spikes must be dynamic. Interactions with host receptors and coreceptors trigger a cascade of conformational changes/structural rearrangements in spikes, which bring virus and host membranes in proximity for membrane fusion required for virus entry. Spike-mediated viral membrane fusion is a dynamic, multi-step process, and understanding the structure–function-dynamics paradigm of virus spikes is essential to elucidate viral membrane fusion, with the ultimate goal of interventions. However, our understanding of this process primarily relies on individual structural snapshots of endpoints. How these endpoints are connected in a time-resolved manner, and the order and frequency of conformational events underlying virus entry, remain largely elusive. Single-molecule Förster resonance energy transfer (smFRET) has provided a powerful platform to connect structure–function in motion, revealing dynamic aspects of spikes for several viruses: SARS-CoV-2, HIV-1, influenza, and Ebola. This review focuses on how smFRET imaging has advanced our understanding of virus spikes’ dynamic nature, receptor-binding events, and mechanism of antibody neutralization, thereby informing therapeutic interventions.
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Affiliation(s)
- Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06536, USA
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46
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HIV-1 Envelope Glycosylation and the Signal Peptide. Vaccines (Basel) 2021; 9:vaccines9020176. [PMID: 33669676 PMCID: PMC7922494 DOI: 10.3390/vaccines9020176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/07/2021] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
The RV144 trial represents the only vaccine trial to demonstrate any protective effect against HIV-1 infection. While the reason(s) for this protection are still being evaluated, it serves as justification for widespread efforts aimed at developing new, more effective HIV-1 vaccines. Advances in our knowledge of HIV-1 immunogens and host antibody responses to these immunogens are crucial to informing vaccine design. While the envelope (Env) protein is the only viral protein present on the surface of virions, it exists in a complex trimeric conformation and is decorated with an array of variable N-linked glycans, making it an important but difficult target for vaccine design. Thus far, efforts to elicit a protective humoral immune response using structural mimics of native Env trimers have been unsuccessful. Notably, the aforementioned N-linked glycans serve as a component of many of the epitopes crucial for the induction of potentially protective broadly neutralizing antibodies (bnAbs). Thus, a greater understanding of Env structural determinants, most critically Env glycosylation, will no doubt be of importance in generating effective immunogens. Recent studies have identified the HIV-1 Env signal peptide (SP) as an important contributor to Env glycosylation. Further investigation into the mechanisms by which the SP directs glycosylation will be important, both in the context of understanding HIV-1 biology and in order to inform HIV-1 vaccine design.
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47
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Tamiz N, Mostashari-Rad T, Najafipour A, Claes S, Schols D, Fassihi A. Synthesis, Molecular Docking and Molecular Dynamics Simulation of 2- Thioxothiazolidin-4-One Derivatives against Gp41. Curr HIV Res 2021; 19:47-60. [PMID: 32885756 DOI: 10.2174/1570162x18666200903172127] [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: 04/22/2020] [Revised: 07/10/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Gp41 and its conserved hydrophobic groove on the N-terminal heptad repeat region are attractive targets in the design of HIV-1 entry inhibitors. Linearly extended molecules have shown potent anti-HIV-1 activity for their effective interactions with the gp41 binding pocket. Rhodanine ring attached to substituted pyrrole or furan rings has been proved a preferred moiety to be inserted inside the molecular structure of the gp41 inhibitors. OBJECTIVES Based on the previous findings we are going to describe some rhodanine derivatives in which a substituted imidazole ring is introduced in place of the pyrrole or furan rings. The compounds' flexibility is increased by inserting methylene groups inside the main scaffold. METHODS Molecular docking and molecular dynamics simulations approaches were exploited to investigate the chemical interactions and the stability of the designed ligands-gp41 complex. All compounds were synthesized and their chemical structures were elucidated by 1HNMR, 13CNMR, FTIR and Mass spectroscopy. Biological activities of the compounds against HIV-1 and HIV-2 and their cellular toxicities against the T-lymphocyte (MT-4) cell line were determined. RESULTS All the designed compounds showed proper and stable chemical interactions with gp41 according to the in silico studies. The results of the biological tests proved none of the compounds active against HIV-1 replication in cell cultures. CONCLUSION Since all the studied compounds were potently toxic for the host cell; it was therefore not possible to assess their anti-HIV activities.
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Affiliation(s)
- Nahid Tamiz
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Tahereh Mostashari-Rad
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Aylar Najafipour
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sandra Claes
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Dominique Schols
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Afshin Fassihi
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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48
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Craft BM, Baker DE. Fostemsavir. Hosp Pharm 2021. [DOI: 10.1177/0018578720985433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are available online to subscribers. Monographs can be customized to meet the needs of a facility. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, contact Wolters Kluwer customer service at 866-397-3433.
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49
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Ashokkumar M, Pattabiraman S, Tripathy SP, Neogi U, Hanna LE. Deep Profiling Identifies Selection of Nonsynonymous Amino Acid Substitutions in HIV-1 Envelope During Early Infection. AIDS Res Hum Retroviruses 2020; 36:1024-1032. [PMID: 32781829 DOI: 10.1089/aid.2020.0143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Understanding the evolutionary dynamics of the viruses within an individual at or near the moment of transmission can provide critical inputs for the design of an effective vaccine for HIV infection. In this study, high-throughput sequencing technology was employed to analyze the evolutionary rate in viruses obtained at a single time point from drug-naive recently infected infants and adults in the chronic stage of disease. Gene-wise nonsynonymous (pN) and synonymous (pS) mutation rates were estimated and compared between the two groups. Significant differences were observed in the evolutionary rates between viruses in the early and late stages of infection. Higher rates of adaptive mutations in the HIV-1 envelope gene (env) were found in the chronic viruses as compared with those in the early stages of HIV infection. Conversely, percentage of nonsynonymous substitutions in env was found to be higher in recently transmitted viruses. In addition, a positive correlation was found between mutation and the evolutionary rate, and infectivity titer in recent infection. Despite the small sample size, the study identified useful information about viral evolution on transmission-associated bottlenecks. The effect of intraindividual HIV-1 evolution at the population level was highly contemporary, and the higher percentage of nonsynonymous substitutions seen in env during recent HIV-1 infection has suggested a pattern of convergent evolution leading to a positive selection for survival fitness and disease progression.
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Affiliation(s)
- Manickam Ashokkumar
- Department of HIV/AIDS, National Institute for Research in Tuberculosis, Chennai, India
| | | | - Srikanth P. Tripathy
- Department of HIV/AIDS, National Institute for Research in Tuberculosis, Chennai, India
| | - Ujjwal Neogi
- Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
| | - Luke Elizabeth Hanna
- Department of HIV/AIDS, National Institute for Research in Tuberculosis, Chennai, India
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Hessell AJ, Powell R, Jiang X, Luo C, Weiss S, Dussupt V, Itri V, Fox A, Shapiro MB, Pandey S, Cheever T, Fuller DH, Park B, Krebs SJ, Totrov M, Haigwood NL, Kong XP, Zolla-Pazner S. Multimeric Epitope-Scaffold HIV Vaccines Target V1V2 and Differentially Tune Polyfunctional Antibody Responses. Cell Rep 2020; 28:877-895.e6. [PMID: 31340151 DOI: 10.1016/j.celrep.2019.06.074] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/12/2019] [Accepted: 06/21/2019] [Indexed: 11/24/2022] Open
Abstract
The V1V2 region of the HIV-1 envelope is the target of several broadly neutralizing antibodies (bNAbs). Antibodies to V1V2 elicited in the RV144 clinical trial correlated with a reduced risk of HIV infection, but these antibodies were without broad neutralizing activity. Antibodies targeting V1V2 also correlated with a reduced viral load in immunized macaques challenged with simian immunodeficiency virus (SIV) or simian/human immunodeficiency virus (SHIV). To focus immune responses on V1V2, we engrafted the native, glycosylated V1V2 domain onto five different multimeric scaffold proteins and conducted comparative immunogenicity studies in macaques. Vaccinated macaques developed high titers of plasma and mucosal antibodies that targeted structurally distinct V1V2 epitopes. Plasma antibodies displayed limited neutralizing activity but were functionally active for ADCC and phagocytosis, which was detectable 1-2 years after immunizations ended. This study demonstrates that multivalent, glycosylated V1V2-scaffold protein immunogens focus the antibody response on V1V2 and are differentially effective at inducing polyfunctional antibodies with characteristics associated with protection.
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Affiliation(s)
- Ann J Hessell
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA.
| | - Rebecca Powell
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Xunqing Jiang
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Christina Luo
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Svenja Weiss
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Vincent Dussupt
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - Vincenza Itri
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Alisa Fox
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mariya B Shapiro
- Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR 97239
| | - Shilpi Pandey
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA
| | - Tracy Cheever
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA
| | - Deborah H Fuller
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Washington National Primate Research Center, Seattle, WA 98195, USA
| | - Byung Park
- Primate Genetics Program, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA
| | - Shelly J Krebs
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | | | - Nancy L Haigwood
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA; Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR 97239.
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA.
| | - Susan Zolla-Pazner
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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