1
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García-Porras M, Torralba J, Insausti S, Valle J, Andreu D, Apellániz B, Nieva JL. A two-step mechanism for the binding of the HIV-1 MPER epitope by the 10E8 antibody onto biosensor-supported lipid bilayers. FEBS Lett 2024; 598:787-800. [PMID: 38339834 DOI: 10.1002/1873-3468.14814] [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: 10/20/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 02/12/2024]
Abstract
HIV-1 antibodies targeting the carboxy-terminal area of the membrane-proximal external region (ctMPER) are close to exerting viral pan-neutralization. Here, we reconstituted the ctMPER epitope as the N-terminal extremity of the Env glycoprotein transmembrane domain helix and immobilized it onto biosensor-supported lipid bilayers. We assessed the binding mechanism of anti-MPER antibody 10E8 through Surface Plasmon Resonance, and found, through equilibrium and kinetic binding analyses as a function of bilayer thickness, peptide length, and paratope mutations, that 10E8 engages first with the epitope peptide (encounter), limited by ctMPER helix accessibility at the membrane surface, and then inserts into the lipid bilayer assisted by favorable Fab-membrane interactions (docking). This mechanistic information may help in devising new strategies to develop more efficient MPER-targeting vaccines.
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Affiliation(s)
- Miguel García-Porras
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Johana Torralba
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Sara Insausti
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Javier Valle
- Laboratory of Proteomics and Protein Chemistry, Department of Medicine and Life Sciences, Pompeu Fabra University, Barcelona, Spain
| | - David Andreu
- Laboratory of Proteomics and Protein Chemistry, Department of Medicine and Life Sciences, Pompeu Fabra University, Barcelona, Spain
| | - Beatriz Apellániz
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
| | - José L Nieva
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
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2
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Rujas E, Apellániz B, Torralba J, Andreu D, Caaveiro JMM, Wang S, Lu S, Nieva JL. Liposome-based peptide vaccines to elicit immune responses against the membrane active domains of the HIV-1 Env glycoprotein. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184235. [PMID: 37793559 DOI: 10.1016/j.bbamem.2023.184235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/12/2023] [Accepted: 09/27/2023] [Indexed: 10/06/2023]
Abstract
The fusion peptide (FP) and the Trp-rich membrane proximal external region (MPER) display membrane activity during HIV-1 fusion. These domains are highly conserved in the envelope glycoprotein (Env) and, consequently, antibodies targeting these regions block entry of divergent HIV strains and isolates into target cells. With the aim of recovering concurrent responses against the membrane-active Env domains, we have produced hybrid peptides that connect FP and MPER sequences via flexible aminohexanoic acid tethers, and tested their potential as immunogens. We demonstrate that liposome-based formulations containing FP-MPER hybrid peptides could elicit in rabbits, antibodies with the binding sequence specificity of neutralizing antibodies that engage with the N-terminal MPER sub-region. Determination of the thermodynamic parameters of binding using the Fab 2F5 as an N-terminal MPER antibody model, revealed that the hydrophobic interaction surface for epitope engagement appears to be optimal in the FP-MPER hybrid. In general, our data support: i) the use of liposomes as carriers for membrane active peptides; ii) the capacity of these liposome-based vaccines to focus humoral responses to N-terminal MPER epitopes; and iii) the need to include lipid membranes in immunogens to elicit such specific responses.
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Affiliation(s)
- Edurne Rujas
- Instituto Biofisika (CSIC, UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
| | - Beatriz Apellániz
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Bioaraba, Microbiology, Infectious Disease, Antimicrobial Agents, and Gene Therapy, 01006 Vitoria-Gasteiz, Spain
| | - Johana Torralba
- Instituto Biofisika (CSIC, UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - David Andreu
- Laboratory of Proteomics and Protein Chemistry, Department of Medicine and Life Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Jose M M Caaveiro
- Laboratory of Global Healthcare, School of Pharmaceutical Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Shixia Wang
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, United States of America
| | - Shan Lu
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, United States of America
| | - Jose L Nieva
- Instituto Biofisika (CSIC, UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
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3
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Torralba J, de la Arada I, Partida-Hanon A, Rujas E, Arribas M, Insausti S, Valotteau C, Valle J, Andreu D, Caaveiro JMM, Jiménez MA, Apellániz B, Redondo-Morata L, Nieva JL. Molecular recognition of a membrane-anchored HIV-1 pan-neutralizing epitope. Commun Biol 2022; 5:1265. [DOI: 10.1038/s42003-022-04219-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/03/2022] [Indexed: 11/19/2022] Open
Abstract
AbstractAntibodies against the carboxy-terminal section of the membrane-proximal external region (C-MPER) of the HIV-1 envelope glycoprotein (Env) are considered as nearly pan-neutralizing. Development of vaccines capable of producing analogous broadly neutralizing antibodies requires deep understanding of the mechanism that underlies C-MPER recognition in membranes. Here, we use the archetypic 10E8 antibody and a variety of biophysical techniques including single-molecule approaches to study the molecular recognition of C-MPER in membrane mimetics. In contrast to the assumption that an interfacial MPER helix embodies the entire C-MPER epitope recognized by 10E8, our data indicate that transmembrane domain (TMD) residues contribute to binding affinity and specificity. Moreover, anchoring to membrane the helical C-MPER epitope through the TMD augments antibody binding affinity and relieves the effects exerted by the interfacial MPER helix on the mechanical stability of the lipid bilayer. These observations support that addition of TMD residues may result in more efficient and stable anti-MPER vaccines.
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4
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Friedrich N, Stiegeler E, Glögl M, Lemmin T, Hansen S, Kadelka C, Wu Y, Ernst P, Maliqi L, Foulkes C, Morin M, Eroglu M, Liechti T, Ivan B, Reinberg T, Schaefer JV, Karakus U, Ursprung S, Mann A, Rusert P, Kouyos RD, Robinson JA, Günthard HF, Plückthun A, Trkola A. Distinct conformations of the HIV-1 V3 loop crown are targetable for broad neutralization. Nat Commun 2021; 12:6705. [PMID: 34795280 PMCID: PMC8602657 DOI: 10.1038/s41467-021-27075-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 11/03/2021] [Indexed: 12/14/2022] Open
Abstract
The V3 loop of the HIV-1 envelope (Env) protein elicits a vigorous, but largely non-neutralizing antibody response directed to the V3-crown, whereas rare broadly neutralizing antibodies (bnAbs) target the V3-base. Challenging this view, we present V3-crown directed broadly neutralizing Designed Ankyrin Repeat Proteins (bnDs) matching the breadth of V3-base bnAbs. While most bnAbs target prefusion Env, V3-crown bnDs bind open Env conformations triggered by CD4 engagement. BnDs achieve breadth by focusing on highly conserved residues that are accessible in two distinct V3 conformations, one of which resembles CCR5-bound V3. We further show that these V3-crown conformations can, in principle, be attacked by antibodies. Supporting this conclusion, analysis of antibody binding activity in the Swiss 4.5 K HIV-1 cohort (n = 4,281) revealed a co-evolution of V3-crown reactivities and neutralization breadth. Our results indicate a role of V3-crown responses and its conformational preferences in bnAb development to be considered in preventive and therapeutic approaches.
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Affiliation(s)
- Nikolas Friedrich
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Emanuel Stiegeler
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.424277.0Present Address: Roche Diagnostics GmbH, Nonnenwald 2, 82377 Penzberg, Deutschland
| | - Matthias Glögl
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Thomas Lemmin
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.5801.c0000 0001 2156 2780Department of Computer Science, ETH Zurich, Zurich, Switzerland ,grid.29078.340000 0001 2203 2861Present Address: Euler Institute, Faculty of Biomedicine, Università della Svizzera italiana (USI), Lugano, Switzerland
| | - Simon Hansen
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland ,Present Address: NGM Bio, 333 Oysterpoint Blvd, South San Francisco, CA 94080 USA
| | - Claus Kadelka
- grid.34421.300000 0004 1936 7312Department of Mathematics, Iowa State University, Ames, IA USA
| | - Yufan Wu
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland ,Present Address: Innovent Biologics Inc, 168 Dongping Street, Suzhou Industrial Park, 215123 China
| | - Patrick Ernst
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland ,grid.7400.30000 0004 1937 0650Present Address: Office Research and Teaching, Medical Faculty, University of Zurich, Zurich, Switzerland
| | - Liridona Maliqi
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Caio Foulkes
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Mylène Morin
- grid.7400.30000 0004 1937 0650Department of Chemistry, University of Zurich (UZH), Zurich, Switzerland ,Present Address: BeiGene Switzerland GmbH, Aeschengraben 27, 4051 Basel, Switzerland
| | - Mustafa Eroglu
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,Present Address: Janssen Vaccines AG, Rehhagstrasse 79, 3018 Bern, Switzerland
| | - Thomas Liechti
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.419681.30000 0001 2164 9667Present Address: ImmunoTechnology Section, Vaccine Research Center, NIAID, NIH, Bethesda, MD USA
| | - Branislav Ivan
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.410567.1Present Address: Laboratory Medicine, Division of Clinical Chemistry, University Hospital Basel, Basel, Switzerland
| | - Thomas Reinberg
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Jonas V. Schaefer
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland ,grid.419481.10000 0001 1515 9979Present Address: Novartis Institutes for BioMedical Research, Chemical Biology & Therapeutics (CBT), Novartis Pharma AG, Virchow 16, 4056 Basel, Switzerland
| | - Umut Karakus
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Stephan Ursprung
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.5335.00000000121885934Present Address: University of Cambridge School of Clinical Medicine, Department of Radiology, Cambridge, CB2 0QQ UK
| | - Axel Mann
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,Present Address: Roche Innovation Center Zurich, Roche Pharmaceutical Research and Early Development (pRED), Wagistrasse 10, 8952 Schlieren, Switzerland
| | - Peter Rusert
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Roger D. Kouyos
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.412004.30000 0004 0478 9977Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich (USZ), Zurich, Switzerland
| | - John A. Robinson
- grid.7400.30000 0004 1937 0650Department of Chemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Huldrych F. Günthard
- grid.7400.30000 0004 1937 0650Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland ,grid.412004.30000 0004 0478 9977Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich (USZ), Zurich, Switzerland
| | - Andreas Plückthun
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Alexandra Trkola
- Institute of Medical Virology, University of Zurich (UZH), Zurich, Switzerland.
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5
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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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6
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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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7
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de la Arada I, Torralba J, Tascón I, Colom A, Ubarretxena-Belandia I, Arrondo JLR, Apellániz B, Nieva JL. Conformational plasticity underlies membrane fusion induced by an HIV sequence juxtaposed to the lipid envelope. Sci Rep 2021; 11:1278. [PMID: 33446748 PMCID: PMC7809034 DOI: 10.1038/s41598-020-80156-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/13/2020] [Indexed: 01/05/2023] Open
Abstract
Envelope glycoproteins from genetically-divergent virus families comprise fusion peptides (FPs) that have been posited to insert and perturb the membranes of target cells upon activation of the virus-cell fusion reaction. Conserved sequences rich in aromatic residues juxtaposed to the external leaflet of the virion-wrapping membranes are also frequently found in viral fusion glycoproteins. These membrane-proximal external regions (MPERs) have been implicated in the promotion of the viral membrane restructuring event required for fusion to proceed, hence, proposed to comprise supplementary FPs. However, it remains unknown whether the structure–function relationships governing canonical FPs also operate in the mirroring MPER sequences. Here, we combine infrared spectroscopy-based approaches with cryo-electron microscopy to analyze the alternating conformations adopted, and perturbations generated in membranes by CpreTM, a peptide derived from the MPER of the HIV-1 Env glycoprotein. Altogether, our structural and morphological data support a cholesterol-dependent conformational plasticity for this HIV-1 sequence, which could assist cell-virus fusion by destabilizing the viral membrane at the initial stages of the process.
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Affiliation(s)
- Igor de la Arada
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain
| | - Johana Torralba
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.,Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain
| | - Igor Tascón
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.,Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain
| | - Adai Colom
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.,Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.,Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain
| | - Iban Ubarretxena-Belandia
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.,Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain
| | - José L R Arrondo
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.,Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain
| | - Beatriz Apellániz
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006, Vitoria-Gasteiz, Spain
| | - José L Nieva
- Instituto Biofisika (CSIC-UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain. .,Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.
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8
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Chiliveri SC, Louis JM, Bax A. Concentration‐Dependent Structural Transition of the HIV‐1 gp41 MPER Peptide into α‐Helical Trimers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202008804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sai Chaitanya Chiliveri
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases Bethesda MD 20892 USA
| | - John M. Louis
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases Bethesda MD 20892 USA
| | - Ad Bax
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases Bethesda MD 20892 USA
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9
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Chiliveri SC, Louis JM, Bax A. Concentration-Dependent Structural Transition of the HIV-1 gp41 MPER Peptide into α-Helical Trimers. Angew Chem Int Ed Engl 2020; 60:166-170. [PMID: 32916024 DOI: 10.1002/anie.202008804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/20/2020] [Indexed: 11/12/2022]
Abstract
The membrane proximal external region (MPER) of HIV-1 gp41 contains epitopes for at least four broadly neutralizing antibodies. Depending on solution conditions and construct design, different structures have been reported for this segment. We show that in aqueous solution the MPER fragment (gp160660-674 ) exists in a monomer-trimer equilibrium with an association constant in the micromolar range. Thermodynamic analysis reveals that the association is exothermic, more favorable in D2 O than H2 O, and increases with ionic strength, indicating hydrophobically driven intermolecular interactions. Circular dichroism, 13 Cα chemical shifts, NOE, and hydrogen exchange rates reveal that MPER undergoes a structural transition from predominately unfolded monomer at low concentrations to an α-helical trimer at high concentrations. This result has implications for antibody recognition of MPER prior to and during the process where gp41 switches from a pre-hairpin intermediate to its post-fusion 6-helical bundle state.
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Affiliation(s)
- Sai Chaitanya Chiliveri
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - John M Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
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10
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Calado R, Duarte J, Borrego P, Marcelino JM, Bártolo I, Martin F, Figueiredo I, Almeida S, Graça L, Vítor J, Aires da Silva F, Dias I, Carrapiço B, Taveira N. A Prime-Boost Immunization Strategy with Vaccinia Virus Expressing Novel gp120 Envelope Glycoprotein from a CRF02_AG Isolate Elicits Cross-Clade Tier 2 HIV-1 Neutralizing Antibodies. Vaccines (Basel) 2020; 8:E171. [PMID: 32272637 PMCID: PMC7349027 DOI: 10.3390/vaccines8020171] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/02/2020] [Accepted: 04/04/2020] [Indexed: 12/22/2022] Open
Abstract
Development of new immunogens eliciting broadly neutralizing antibodies (bNAbs) is a main priority for the HIV-1 vaccine field. Envelope glycoproteins from non-B-non-C HIV-1clades have not been fully explored as components of a vaccine. We produced Vaccinia viruses expressing a truncated version of gp120 (gp120t) from HIV-1 clades CRF02_AG, H, J, B, and C and examined their immunogenicity in mice and rabbits. Mice primed with the recombinant Vaccinia viruses and boosted with the homologous gp120t or C2V3C3 polypeptides developed antibodies that bind potently to homologous and heterologous envelope glycoproteins. Notably, a subset of mice immunized with the CRF02_AG-based envelope immunogens developed a cross-reactive neutralizing response against tier 2 HIV-1 Env-pseudoviruses and primary isolates. Rabbits vaccinated with the CRF02_AG-based envelope immunogens also generated potent binding antibodies, and one animal elicited antibodies that neutralized almost all (13 of 16, 81.3%) tier 2 HIV-1 isolates tested. Overall, the results suggest that the novel CRF02_AG-based envelope immunogens and prime-boost immunization strategy elicit the type of immune responses required for a preventive HIV-1 vaccine.
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Affiliation(s)
- Rita Calado
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
| | - Joana Duarte
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
| | - Pedro Borrego
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
| | - José Maria Marcelino
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, 2829-511 Monte de Caparica, Portugal
| | - Inês Bártolo
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
| | - Francisco Martin
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
| | - Inês Figueiredo
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
| | - Silvia Almeida
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de Lisboa, 1649-02 Lisboa, Portugal; (S.A.); (L.G.)
- Post-Graduate Program in Infectious Diseases, and Department of Social Medicine, Center of Health Sciences, Federal University of Espirito Santo, Vitória 29075-910, Brazil
| | - Luís Graça
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de Lisboa, 1649-02 Lisboa, Portugal; (S.A.); (L.G.)
| | - Jorge Vítor
- Biochemistry and Human Biology Dept, Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal;
| | - Frederico Aires da Silva
- Faculdade de Medicina Veterinária, Universidade de Lisboa, 1300-477 Lisboa, Portugal; (F.A.d.S.); (I.D.); (B.C.)
| | - Inês Dias
- Faculdade de Medicina Veterinária, Universidade de Lisboa, 1300-477 Lisboa, Portugal; (F.A.d.S.); (I.D.); (B.C.)
| | - Belmira Carrapiço
- Faculdade de Medicina Veterinária, Universidade de Lisboa, 1300-477 Lisboa, Portugal; (F.A.d.S.); (I.D.); (B.C.)
| | - Nuno Taveira
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (R.C.); (J.D.); (P.B.); (J.M.M.); (I.B.); (F.M.); (I.F.)
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, 2829-511 Monte de Caparica, Portugal
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11
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Ang CG, Hossain MA, Rajpara M, Bach H, Acharya K, Dick A, Rashad AA, Kutzler M, Abrams CF, Chaiken I. Metastable HIV-1 Surface Protein Env Sensitizes Cell Membranes to Transformation and Poration by Dual-Acting Virucidal Entry Inhibitors. Biochemistry 2020; 59:818-828. [PMID: 31942789 PMCID: PMC7362902 DOI: 10.1021/acs.biochem.9b01008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dual-acting virucidal entry inhibitors (DAVEIs) have previously been shown to cause irreversible inactivation of HIV-1 Env-presenting pseudovirus by lytic membrane transformation. This study examined whether this transformation could be generalized to include membranes of Env-presenting cells. Flow cytometry was used to analyze HEK293T cells transiently transfected with increasing amounts of DNA encoding JRFL Env, loaded with calcein dye, and treated with serial dilutions of microvirin (Q831K/M83R)-DAVEI. Comparing calcein retention against intact Env expression (via Ab 35O22) on individual cells revealed effects proportional to Env expression. "Low-Env" cells experienced transient poration and calcein leakage, while "high-Env" cells were killed. The cell-killing effect was confirmed with an independent mitochondrial activity-based cell viability assay, showing dose-dependent cytotoxicity in response to DAVEI treatment. Transfection with increasing quantities of Env DNA showed further shifts toward "High-Env" expression and cytotoxicity, further reinforcing the Env dependence of the observed effect. Controls with unlinked DAVEI components showed no effect on calcein leakage or cell viability, confirming a requirement for covalently linked DAVEI compounds to achieve Env transformation. These data demonstrate that the metastability of Env is an intrinsic property of the transmembrane protein complex and can be perturbed to cause membrane disruption in both virus and cell contexts.
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Affiliation(s)
- Charles G Ang
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
- School of Biomedical Engineering, Science, and Health Systems , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Md Alamgir Hossain
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Marg Rajpara
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Harry Bach
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
- School of Biomedical Engineering, Science, and Health Systems , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Kriti Acharya
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Alexej Dick
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Adel A Rashad
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Michele Kutzler
- Department of Microbiology and Immunology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
| | - Cameron F Abrams
- Department of Chemical and Biological Engineering, College of Engineering , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Irwin Chaiken
- Department of Biochemistry and Molecular Biology, College of Medicine , Drexel University , Philadelphia , Pennsylvania 19102 , United States
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12
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Yuan C, Wang JY, Zhao HJ, Li Y, Li D, Ling H, Zhuang M. Mutations of Glu560 within HIV-1 Envelope Glycoprotein N-terminal heptad repeat region contribute to resistance to peptide inhibitors of virus entry. Retrovirology 2019; 16:36. [PMID: 31796053 PMCID: PMC6889725 DOI: 10.1186/s12977-019-0496-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/21/2019] [Indexed: 11/17/2022] Open
Abstract
Background Peptides corresponding to N- and C-terminal heptad repeat regions (HR1 and HR2, respectively) of gp41 can inhibit HIV-1 infection in a dominant negative manner by interfering with refolding of the viral HR1 and HR2 to form a six-helix bundle (6HB) that induces fusion between viral and host cell membranes. Previously, we found that HIV-1 acquired the mutations of Glu560 (E560) in HR1 of envelope (Env) to escape peptide inhibitors. The present study aimed to elucidate the critical role of position 560 in the virus entry and potential resistance mechanisms. Results The Glu560Lys/Asp/Gly (E560K/D/G) mutations in HR1 of gp41 that are selected under the pressure of N- and C-peptide inhibitors modified its molecular interactions with HR2 to change 6HB stability and peptide inhibitor binding. E560K mutation increased 6HB thermostability and resulted in resistance to N peptide inhibitors, but E560G or E560D as compensatory mutations destabilized the 6HB to reduce inhibitor binding and resulted in increased resistance to C peptide inhibitor, T20. Significantly, the neutralizing activities of all mutants to soluble CD4 and broadly neutralizing antibodies targeting membrane proximal external region, 2F5 and 4E10 were improved, indicating the mutations of E560 could regulate Env conformations through cross interactions with gp120 or gp41. The molecular modeling analysis of E560K/D/G mutants suggested that position 560 might interact with the residues within two potentially flexible topological layer 1 and layer 2 in the gp120 inner domain to apparently affect the CD4 utilization. The E560K/D/G mutations changed its interactions with Gln650 (Q650) in HR2 to contribute to the resistance of peptide inhibitors. Conclusions These findings identify the contributions of mutations of E560K/D/G in the highly conserved gp41 and highlight Env’s high degree of plasticity for virus entry and inhibitor design.
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Affiliation(s)
- Chen Yuan
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Jia-Ye Wang
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China
| | - Hai-Jiao Zhao
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Yan Li
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China.,Key Laboratory of Pathogen Biology, Harbin, China
| | - Di Li
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China.,Key Laboratory of Pathogen Biology, Harbin, China
| | - Hong Ling
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China. .,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China. .,Key Laboratory of Pathogen Biology, Harbin, China. .,Wu Lien-Teh Institute, Harbin Medical University, Harbin, China.
| | - Min Zhuang
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China. .,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China. .,Key Laboratory of Pathogen Biology, Harbin, China. .,Wu Lien-Teh Institute, Harbin Medical University, Harbin, China.
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13
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Rudometov AP, Chikaev AN, Rudometova NB, Antonets DV, Lomzov AA, Kaplina ON, Ilyichev AA, Karpenko LI. Artificial Anti-HIV-1 Immunogen Comprising Epitopes of Broadly Neutralizing Antibodies 2F5, 10E8, and a Peptide Mimic of VRC01 Discontinuous Epitope. Vaccines (Basel) 2019; 7:vaccines7030083. [PMID: 31390770 PMCID: PMC6789618 DOI: 10.3390/vaccines7030083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 01/05/2023] Open
Abstract
The construction of artificial proteins using conservative B-cell and T-cell epitopes is believed to be a promising approach for a vaccine design against diverse viral infections. This article describes the development of an artificial HIV-1 immunogen using a polyepitope immunogen design strategy. We developed a recombinant protein, referred to as nTBI, that contains epitopes recognized by broadly neutralizing HIV-1 antibodies (bNAbs) combined with Th-epitopes. This is a modified version of a previously designed artificial protein, TBI (T- and B-cell epitopes containing Immunogen), carrying four T- and five B-cell epitopes from HIV-1 Env and Gag proteins. To engineer the nTBI molecule, three B-cell epitopes of the TBI protein were replaced with the epitopes recognized by broadly neutralizing HIV-1 antibodies 10E8, 2F5, and a linear peptide mimic of VRC01 epitope. We showed that immunization of rabbits with the nTBI protein elicited antibodies that recognize HIV-1 proteins and were able to neutralize Env-pseudotyped SF162.LS HIV-1 strain (tier 1). Competition assay revealed that immunization of rabbits with nTBI induced mainly 10E8-like antibodies. Our findings support the use of nTBI protein as an immunogen with predefined favorable antigenic properties.
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Affiliation(s)
- Andrey P Rudometov
- State Research Center of Virology and Biotechnology "Vector", Koltsovo, Novosibirsk Region 630559, Russia.
| | - Anton N Chikaev
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences, 8/2 Lavrentiev Avenue Novosibirsk, Novosibirsk 630090, Russia.
| | - Nadezhda B Rudometova
- State Research Center of Virology and Biotechnology "Vector", Koltsovo, Novosibirsk Region 630559, Russia
| | - Denis V Antonets
- State Research Center of Virology and Biotechnology "Vector", Koltsovo, Novosibirsk Region 630559, Russia
| | - Alexander A Lomzov
- Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Olga N Kaplina
- State Research Center of Virology and Biotechnology "Vector", Koltsovo, Novosibirsk Region 630559, Russia
| | - Alexander A Ilyichev
- State Research Center of Virology and Biotechnology "Vector", Koltsovo, Novosibirsk Region 630559, Russia
| | - Larisa I Karpenko
- State Research Center of Virology and Biotechnology "Vector", Koltsovo, Novosibirsk Region 630559, Russia.
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14
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Immunogenicity and Efficacy of a Novel Multi-Antigenic Peptide Vaccine Based on Cross-Reactivity between Feline and Human Immunodeficiency Viruses. Viruses 2019; 11:v11020136. [PMID: 30717485 PMCID: PMC6409633 DOI: 10.3390/v11020136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/12/2022] Open
Abstract
For the development of an effective HIV-1 vaccine, evolutionarily conserved epitopes between feline and human immunodeficiency viruses (FIV and HIV-1) were determined by analyzing overlapping peptides from retroviral genomes that induced both anti-FIV/HIV T cell-immunity in the peripheral blood mononuclear cells from the FIV-vaccinated cats and the HIV-infected humans. The conserved T-cell epitopes on p24 and reverse transcriptase were selected based on their robust FIV/HIV-specific CD8⁺ cytotoxic T lymphocyte (CTL), CD4⁺ CTL, and polyfunctional T-cell activities. Four such evolutionarily conserved epitopes were formulated into four multiple antigen peptides (MAPs), mixed with an adjuvant, to be tested as FIV vaccine in cats. The immunogenicity and protective efficacy were evaluated against a pathogenic FIV. More MAP/peptide-specific CD4⁺ than CD8⁺ T-cell responses were initially observed. By post-third vaccination, half of the MAP/peptide-specific CD8⁺ T-cell responses were higher or equivalent to those of CD4⁺ T-cell responses. Upon challenge, 15/19 (78.9%) vaccinated cats were protected, whereas 6/16 (37.5%) control cats remained uninfected, resulting in a protection rate of 66.3% preventable fraction (p = 0.0180). Thus, the selection method used to identify the protective FIV peptides should be useful in identifying protective HIV-1 peptides needed for a highly protective HIV-1 vaccine in humans.
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15
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Abstract
A large array of broadly neutralizing antibodies (bnAbs) against HIV have been isolated and described, particularly in the last decade. This continually expanding array of bnAbs has crucially led to the identification of novel epitopes on the HIV envelope protein via which antibodies can block a broad range of HIV strains. Moreover, these studies have produced high-resolution understanding of these sites of vulnerability on the envelope protein. They have also clarified the mechanisms of action of bnAbs and provided detailed descriptions of B cell ontogenies from which they arise. However, it is still not possible to predict which HIV-infected individuals will go onto develop breath nor is it possible to induce neutralization breadth by immunization in humans. This review aims to discuss the major insights gained so far and also to evaluate the requirement to continue isolating and characterizing new bnAbs. While new epitopes may remain to be uncovered, a clearer probable benefit of further bnAb characterization is a greater understanding of key decision points in bnAb development within the anti-HIV immune response. This in turn may lead to new insights into how to trigger bnAbs by immunization and more clearly define the challenges to using bnAbs as therapeutic agents.
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Affiliation(s)
- Laura E McCoy
- Division of Infection and Immunity, University College London, London, UK.
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16
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Benton DJ, Nans A, Calder LJ, Turner J, Neu U, Lin YP, Ketelaars E, Kallewaard NL, Corti D, Lanzavecchia A, Gamblin SJ, Rosenthal PB, Skehel JJ. Influenza hemagglutinin membrane anchor. Proc Natl Acad Sci U S A 2018; 115:10112-10117. [PMID: 30224494 PMCID: PMC6176637 DOI: 10.1073/pnas.1810927115] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Viruses with membranes fuse them with cellular membranes, to transfer their genomes into cells at the beginning of infection. For Influenza virus, the membrane glycoprotein involved in fusion is the hemagglutinin (HA), the 3D structure of which is known from X-ray crystallographic studies. The soluble ectodomain fragments used in these studies lacked the "membrane anchor" portion of the molecule. Since this region has a role in membrane fusion, we have determined its structure by analyzing the intact, full-length molecule in a detergent micelle, using cryo-EM. We have also compared the structures of full-length HA-detergent micelles with full-length HA-Fab complex detergent micelles, to describe an infectivity-neutralizing monoclonal Fab that binds near the ectodomain membrane anchor junction. We determine a high-resolution HA structure which compares favorably in detail with the structure of the ectodomain seen by X-ray crystallography; we detect, clearly, all five carbohydrate side chains of HA; and we find that the ectodomain is joined to the membrane anchor by flexible, eight-residue-long, linkers. The linkers extend into the detergent micelle to join a central triple-helical structure that is a major component of the membrane anchor.
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Affiliation(s)
- Donald J Benton
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom;
| | - Andrea Nans
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom
- Structural Biology Science Technology Platform, Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Lesley J Calder
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Jack Turner
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Ursula Neu
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Yi Pu Lin
- Worldwide Influenza Centre, Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Esther Ketelaars
- Institute for Research in Biomedicine, 6500 Bellinzona, Switzerland
| | | | | | | | - Steven J Gamblin
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom;
| | - John J Skehel
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, NW1 1AT London, United Kingdom;
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17
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Ringel O, Vieillard V, Debré P, Eichler J, Büning H, Dietrich U. The Hard Way towards an Antibody-Based HIV-1 Env Vaccine: Lessons from Other Viruses. Viruses 2018; 10:v10040197. [PMID: 29662026 PMCID: PMC5923491 DOI: 10.3390/v10040197] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/05/2018] [Accepted: 04/13/2018] [Indexed: 12/13/2022] Open
Abstract
Although effective antibody-based vaccines have been developed against multiple viruses, such approaches have so far failed for the human immunodeficiency virus type 1 (HIV-1). Despite the success of anti-retroviral therapy (ART) that has turned HIV-1 infection into a chronic disease and has reduced the number of new infections worldwide, a vaccine against HIV-1 is still urgently needed. We discuss here the major reasons for the failure of “classical” vaccine approaches, which are mostly due to the biological properties of the virus itself. HIV-1 has developed multiple mechanisms of immune escape, which also account for vaccine failure. So far, no vaccine candidate has been able to induce broadly neutralizing antibodies (bnAbs) against primary patient viruses from different clades. However, such antibodies were identified in a subset of patients during chronic infection and were shown to protect from infection in animal models and to reduce viremia in first clinical trials. Their detailed characterization has guided structure-based reverse vaccinology approaches to design better HIV-1 envelope (Env) immunogens. Furthermore, conserved Env epitopes have been identified, which are promising candidates in view of clinical applications. Together with new vector-based technologies, considerable progress has been achieved in recent years towards the development of an effective antibody-based HIV-1 vaccine.
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Affiliation(s)
- Oliver Ringel
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, 60596 Frankfurt, Germany.
| | - Vincent Vieillard
- Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Sorbonne Université, UPMC Univ Paris 06, INSERM U1135, CNRS ERL8255, 75013 Paris, France.
| | - Patrice Debré
- Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Sorbonne Université, UPMC Univ Paris 06, INSERM U1135, CNRS ERL8255, 75013 Paris, France.
| | - Jutta Eichler
- Department of Chemistry and Pharmacy, University of Erlangen-Nurnberg, 91058 Erlangen, Germany.
| | - Hildegard Büning
- Laboratory for Infection Biology & Gene Transfer, Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany.
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 38124 Braunschweig, Germany.
| | - Ursula Dietrich
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, 60596 Frankfurt, Germany.
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18
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Ringel O, Müller K, Koch J, Brill B, Wolf T, Stephan C, Vieillard V, Debré P, Dietrich U. Optimization of the EC26-2A4 Epitope in the gp41 Membrane Proximal External Region Targeted by Neutralizing Antibodies from an Elite Controller. AIDS Res Hum Retroviruses 2018; 34:365-374. [PMID: 29262692 PMCID: PMC5899297 DOI: 10.1089/aid.2017.0250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The analysis of patient derived HIV neutralizing antibodies (nAbs) and their target epitopes in the viral envelope (Env) protein provides important basic information for vaccine design. In this study we optimized an epitope, EC26-2A4, that is targeted by neutralizing antibodies from an elite controller (EC26) and localizes in the membrane-proximal external region from the gp41 transmembrane protein. Due to its overlap with the epitope of the first generation broadly neutralizing monoclonal Ab (mAb) 2F5 associated with autoreactivity, we first defined the minimal core epitope reacting with antibodies from EC26 plasma, but not with mAb 2F5. The optimized minimal epitope, EC26-2A4ΔM, was able to induce neutralizing antibodies in vaccinated mice. We further analyzed the frequency of antibodies against the EC26-2A4ΔM peptide in HIV-positive patient sera from a treated cohort and an untreated long-term nonprogressor (LTNP) cohort. Interestingly, 27% of the LTNP sera reacted with the peptide, whereas only 9% showed reactivity in the treated cohort. Although there was no association between the presence of antibodies against the EC26-2A4ΔM epitope and viral load or CD4 count in these patients, the CD4 nadir in the treated cohort was higher in patients positive for EC26-2A4ΔM antibodies, in particular in patients having such antibodies at an early and a late timepoint after infection.
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Affiliation(s)
- Oliver Ringel
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt, Germany
| | - Karsten Müller
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt, Germany
- Department of Infectious Diseases, HIV Center, University Hospital, Frankfurt, Germany
| | - Joachim Koch
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt, Germany
| | - Boris Brill
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt, Germany
| | - Timo Wolf
- Department of Infectious Diseases, HIV Center, University Hospital, Frankfurt, Germany
| | - Christoph Stephan
- Department of Infectious Diseases, HIV Center, University Hospital, Frankfurt, Germany
| | - Vincent Vieillard
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U1135, CNRS ERL8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Patrice Debré
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U1135, CNRS ERL8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Ursula Dietrich
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt, Germany
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19
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Functional Optimization of Broadly Neutralizing HIV-1 Antibody 10E8 by Promotion of Membrane Interactions. J Virol 2018; 92:JVI.02249-17. [PMID: 29386285 DOI: 10.1128/jvi.02249-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/26/2018] [Indexed: 11/20/2022] Open
Abstract
The 10E8 antibody targets a helical epitope in the membrane-proximal external region (MPER) and transmembrane domain (TMD) of the envelope glycoprotein (Env) subunit gp41 and is among the broadest known neutralizing antibodies against HIV-1. Accordingly, this antibody and its mechanism of action valuably inform the design of effective vaccines and immunotherapies. 10E8 exhibits unusual adaptations to attain specific, high-affinity binding to the MPER at the viral membrane interface. Reversing the charge of the basic paratope surface (from net positive to net negative) reportedly lowered its neutralization potency. Here, we hypothesized that by increasing the net positive charge in similar polar surface patches, the neutralization potency of the antibody may be enhanced. We found that an increased positive charge at this paratope surface strengthened an electrostatic interaction between the antibody and lipid bilayers, enabling 10E8 to interact spontaneously with membranes. Notably, the modified 10E8 antibody did not gain any apparent polyreactivity and neutralized virus with a significantly greater potency. Binding analyses indicated that the optimized 10E8 antibody bound with a higher affinity to the epitope peptide anchored in lipid bilayers and to Env spikes on virions. Overall, our data provide a proof of principle for the rational optimization of 10E8 via manipulation of its interaction with the membrane element of its epitope. However, the observation that a similar mutation strategy did not affect the potency of the first-generation anti-MPER antibody 4E10 shows possible limitations of this principle. Altogether, our results emphasize the crucial role played by the viral membrane in the antigenicity of the MPER-TMD of HIV-1.IMPORTANCE The broadly neutralizing antibody 10E8 blocks infection by nearly all HIV-1 isolates, a capacity which vaccine design seeks to reproduce. Engineered versions of this antibody also represent a promising treatment for HIV infection by passive immunization. Understanding its mechanism of action is therefore important to help in developing effective vaccines and biologics to combat HIV/AIDS. 10E8 engages its helical MPER epitope where the base of the envelope spike submerges into the viral membrane. To enable this interaction, this antibody evolved an unusual property: the ability to interact with the membrane surface. Here, we provide evidence that 10E8 can be made more effective by enhancing its interactions with membranes. Our findings strengthen the idea that to elicit antibodies similar to 10E8, vaccines must reproduce the membrane environment where these antibodies perform their function.
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Oakes V, Torralba J, Rujas E, Nieva JL, Domene C, Apellaniz B. Exposure of the HIV-1 broadly neutralizing antibody 10E8 MPER epitope on the membrane surface by gp41 transmembrane domain scaffolds. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1259-1271. [PMID: 29477358 DOI: 10.1016/j.bbamem.2018.02.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/30/2018] [Accepted: 02/20/2018] [Indexed: 12/27/2022]
Abstract
The 10E8 antibody achieves near-pan neutralization of HIV-1 by targeting the remarkably conserved gp41 membrane-proximal external region (MPER) and the connected transmembrane domain (TMD) of the HIV-1 envelope glycoprotein (Env). Thus, recreating the structure that generates 10E8-like antibodies is a major goal of the rational design of anti-HIV vaccines. Unfortunately, high-resolution information of this segment in the native Env is lacking, limiting our understanding of the behavior of the crucial 10E8 epitope residues. In this report, two sequences, namely, MPER-TMD1 (gp41 residues 671-700) and MPER-TMD2 (gp41 residues 671-709) were compared both experimentally and computationally, to assess the TMD as a potential membrane integral scaffold for the 10E8 epitope. These sequences were selected to represent a minimal (MPER-TMD1) or full-length (MPER-TMD2) TMD membrane anchor according to mutagenesis results reported by Yue et al. (2009) J. Virol. 83, 11,588. Immunochemical assays revealed that MPER-TMD1, but not MPER-TMD2, effectively exposed the MPER C-terminal stretch, harboring the 10E8 epitope on the surface of phospholipid bilayers containing a cholesterol concentration equivalent to that of the viral envelope. Molecular dynamics simulations, using the recently resolved TMD trimer structure combined with the MPER in a cholesterol-enriched model membrane confirmed these results and provided an atomistic mechanism of epitope exposure which revealed that TMD truncation at position A700 combined with N-terminal addition of lysine residues positively impacts epitope exposure. Overall, these results provide crucial insights into the design of effective MPER-TMD derived immunogens.
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Affiliation(s)
- Victoria Oakes
- Department of Chemistry, Britannia House, 7 Trinity Street, King's College London, London SE1 1DB, UK; Department of Chemistry, 1 South Building, Claverton Down Road, University of Bath, Bath BA2 7AY, UK
| | - Johana Torralba
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Edurne Rujas
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Carmen Domene
- Department of Chemistry, 1 South Building, Claverton Down Road, University of Bath, Bath BA2 7AY, UK; Chemistry Research Laboratory, Mansfield Road, University of Oxford, Oxford OX1 3TA, UK.
| | - Beatriz Apellaniz
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
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Abstract
Despite major advances in antiretroviral therapy against HIV-1, an effective HIV vaccine is urgently required to reduce the number of new cases of HIV infections in the world. Vaccines are the ultimate tool in the medical arsenal to control and prevent the spread of infectious diseases such as HIV/AIDS. Several failed phase-IIb to –III clinical vaccine trials against HIV-1 in the past generated a plethora of information that could be used for better designing of an effective HIV vaccine in the future. Most of the tested vaccine candidates produced strong humoral responses against the HIV proteins; however, failed to protect due to: 1) the low levels and the narrow breadth of the HIV-1 neutralizing antibodies and the HIV-specific antibody-dependent Fc-mediated effector activities, 2) the low levels and the poor quality of the anti-HIV T-cell responses, and 3) the excessive responses to immunodominant non-protective HIV epitopes, which in some cases blocked the protective immunity and/or enhanced HIV infection. The B-cell epitopes on HIV for producing broadly neutralizing antibodies (bNAbs) against HIV have been extensively characterized, and the next step is to develop bNAb epitope immunogen for HIV vaccine. The bNAb epitopes are often conformational epitopes and therefore more difficult to construct as vaccine immunogen and likely to include immunodominant non-protective HIV epitopes. In comparison, T-cell epitopes are short linear peptides which are easier to construct into vaccine immunogen free of immunodominant non-protective epitopes. However, its difficulty lies in identifying the T-cell epitopes conserved among HIV subtypes and induce long-lasting, potent polyfunctional T-cell and cytotoxic T lymphocyte (CTL) activities against HIV. In addition, these protective T-cell epitopes must be recognized by the HLA prevalent in the country(s) targeted for the vaccine trial. In conclusion, extending from the findings from previous vaccine trials, future vaccines should combine both T- and B-cell epitopes as vaccine immunogen to induce multitude of broad and potent immune effector activities required for sterilizing protection against global HIV subtypes.
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Affiliation(s)
- Bikash Sahay
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 110880, Gainesville, FL 32611-0880, USA
| | - Cuong Q Nguyen
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 110880, Gainesville, FL 32611-0880, USA
| | - Janet K Yamamoto
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 110880, Gainesville, FL 32611-0880, USA
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