1
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Banerjee P, Qu K, Briggs JAG, Voth GA. Molecular dynamics simulations of HIV-1 matrix-membrane interactions at different stages of viral maturation. Biophys J 2024; 123:389-406. [PMID: 38196190 PMCID: PMC10870173 DOI: 10.1016/j.bpj.2024.01.006] [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: 09/25/2023] [Revised: 12/05/2023] [Accepted: 01/04/2024] [Indexed: 01/11/2024] Open
Abstract
Although the structural rearrangement of the membrane-bound matrix (MA) protein trimers upon HIV-1 maturation has been reported, the consequences of MA maturation on the MA-lipid interactions are not well understood. Long-timescale molecular dynamics simulations of the MA multimeric assemblies of immature and mature virus particles with our realistic asymmetric membrane model have explored MA-lipid interactions and lateral organization of lipids around MA complexes. The number of stable MA-phosphatidylserine and MA-phosphatidylinositol 4,5-bisphosphate (PIP2) interactions at the trimeric interface of the mature MA complex is observed to be greater compared to that of the immature MA complex. Our simulations identified an alternative PIP2-binding site in the immature MA complex where the multivalent headgroup of a PIP2 lipid with a greater negative charge binds to multiple basic amino acid residues such as ARG3 residues of both the MA monomers at the trimeric interface and highly basic region (HBR) residues (LYS29, LYS31) of one of the MA monomers. Our enhanced sampling simulations have explored the conformational space of phospholipids at different binding sites of the trimer-trimer interface of MA complexes that are not accessible by conventional unbiased molecular dynamics. Unlike the immature MA complex, the 2' acyl tail of two PIP2 lipids at the trimeric interface of the mature MA complex is observed to sample stable binding pockets of MA consisting of helix-4 residues. Together, our results provide molecular-level insights into the interactions of MA trimeric complexes with membrane and different lipid conformations at the specific binding sites of MA protein before and after viral maturation.
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Affiliation(s)
- Puja Banerjee
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois
| | - Kun Qu
- Infectious Diseases Translational Research Programme, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - John A G Briggs
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Planegg, Germany
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois.
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2
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Abstract
There are at least 21 families of enveloped viruses that infect mammals, and many contain members of high concern for global human health. All enveloped viruses have a dedicated fusion protein or fusion complex that enacts the critical genome-releasing membrane fusion event that is essential before viral replication within the host cell interior can begin. Because all enveloped viruses enter cells by fusion, it behooves us to know how viral fusion proteins function. Viral fusion proteins are also major targets of neutralizing antibodies, and hence they serve as key vaccine immunogens. Here we review current concepts about viral membrane fusion proteins focusing on how they are triggered, structural intermediates between pre- and postfusion forms, and their interplay with the lipid bilayers they engage. We also discuss cellular and therapeutic interventions that thwart virus-cell membrane fusion.
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Affiliation(s)
- Judith M White
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA;
| | - Amanda E Ward
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Laura Odongo
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Lukas K Tamm
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
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3
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Tate P, Mastrodomenico V, Cunha C, McClure J, Barron AE, Diamond G, Mounce BC, Kirshenbaum K. Peptidomimetic Oligomers Targeting Membrane Phosphatidylserine Exhibit Broad Antiviral Activity. ACS Infect Dis 2023; 9:1508-1522. [PMID: 37530426 PMCID: PMC10425984 DOI: 10.1021/acsinfecdis.3c00063] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Indexed: 08/03/2023]
Abstract
The development of durable new antiviral therapies is challenging, as viruses can evolve rapidly to establish resistance and attenuate therapeutic efficacy. New compounds that selectively target conserved viral features are attractive therapeutic candidates, particularly for combating newly emergent viral threats. The innate immune system features a sustained capability to combat pathogens through production of antimicrobial peptides (AMPs); however, these AMPs have shortcomings that can preclude clinical use. The essential functional features of AMPs have been recapitulated by peptidomimetic oligomers, yielding effective antibacterial and antifungal agents. Here, we show that a family of AMP mimetics, called peptoids, exhibit direct antiviral activity against an array of enveloped viruses, including the key human pathogens Zika, Rift Valley fever, and chikungunya viruses. These data suggest that the activities of peptoids include engagement and disruption of viral membrane constituents. To investigate how these peptoids target lipid membranes, we used liposome leakage assays to measure membrane disruption. We found that liposomes containing phosphatidylserine (PS) were markedly sensitive to peptoid treatment; in contrast, liposomes formed exclusively with phosphatidylcholine (PC) showed no sensitivity. In addition, chikungunya virus containing elevated envelope PS was more susceptible to peptoid-mediated inactivation. These results indicate that peptoids mimicking the physicochemical characteristics of AMPs act through a membrane-specific mechanism, most likely through preferential interactions with PS. We provide the first evidence for the engagement of distinct viral envelope lipid constituents, establishing an avenue for specificity that may enable the development of a new family of therapeutics capable of averting the rapid development of resistance.
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Affiliation(s)
- Patrick
M. Tate
- Department
of Chemistry, New York University, New York, New York 10003, United States
| | - Vincent Mastrodomenico
- Department
of Microbiology and Immunology, Loyola University
Chicago Medical Center, Maywood, Illinois 60130, United States
| | - Christina Cunha
- Department
of Microbiology and Immunology, Loyola University
Chicago Medical Center, Maywood, Illinois 60130, United States
| | | | - Annelise E. Barron
- Maxwell
Biosciences, Austin, Texas 78738, United States
- Department
of Bioengineering, Stanford University, Stanford, California 94305, United States
| | - Gill Diamond
- Department
of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, Kentucky 40292, United States
| | - Bryan C. Mounce
- Department
of Microbiology and Immunology, Loyola University
Chicago Medical Center, Maywood, Illinois 60130, United States
| | - Kent Kirshenbaum
- Department
of Chemistry, New York University, New York, New York 10003, United States
- Maxwell
Biosciences, Austin, Texas 78738, United States
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4
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Yoo SW, Waheed AA, Deme P, Tohumeken S, Rais R, Smith MD, DeMarino C, Calabresi PA, Kashanchi F, Freed EO, Slusher BS, Haughey NJ. Inhibition of neutral sphingomyelinase 2 impairs HIV-1 envelope formation and substantially delays or eliminates viral rebound. Proc Natl Acad Sci U S A 2023; 120:e2219543120. [PMID: 37406092 PMCID: PMC10334757 DOI: 10.1073/pnas.2219543120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 04/03/2023] [Indexed: 07/07/2023] Open
Abstract
Although HIV-1 Gag is known to drive viral assembly and budding, the precise mechanisms by which the lipid composition of the plasma membrane is remodeled during assembly are incompletely understood. Here, we provide evidence that the sphingomyelin hydrolase neutral sphingomyelinase 2 (nSMase2) interacts with HIV-1 Gag and through the hydrolysis of sphingomyelin creates ceramide that is necessary for proper formation of the viral envelope and viral maturation. Inhibition or depletion of nSMase2 resulted in the production of noninfectious HIV-1 virions with incomplete Gag lattices lacking condensed conical cores. Inhibition of nSMase2 in HIV-1-infected humanized mouse models with a potent and selective inhibitor of nSMase2 termed PDDC [phenyl(R)-(1-(3-(3,4-dimethoxyphenyl)-2, 6-dimethylimidazo[1,2-b]pyridazin-8-yl) pyrrolidin-3-yl)-carbamate] produced a linear reduction in levels of HIV-1 in plasma. If undetectable plasma levels of HIV-1 were achieved with PDDC treatment, viral rebound did not occur for up to 4 wk when PDDC was discontinued. In vivo and tissue culture results suggest that PDDC selectively kills cells with actively replicating HIV-1. Collectively, this work demonstrates that nSMase2 is a critical regulator of HIV-1 replication and suggests that nSMase2 could be an important therapeutic target with the potential to kill HIV-1-infected cells.
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Affiliation(s)
- Seung-Wan Yoo
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
| | - Abdul A. Waheed
- Virus-Cell Interaction Section, HIV-1 Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD21702
| | - Pragney Deme
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
| | - Sehmus Tohumeken
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
| | - Rana Rais
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Matthew D. Smith
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
| | - Catherine DeMarino
- Laboratory of Molecular Virology, George Mason University, Manassas, VA20110
| | - Peter A. Calabresi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
| | - Fatah Kashanchi
- Laboratory of Molecular Virology, George Mason University, Manassas, VA20110
| | - Eric O. Freed
- Virus-Cell Interaction Section, HIV-1 Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD21702
| | - Barbara S. Slusher
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD21210
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD21210
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD21224
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD21210
| | - Norman J. Haughey
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD21210
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD21210
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5
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Ward AE, Sokovikova D, Waxham MN, Heberle FA, Levental I, Levental KR, Kiessling V, White JM, Tamm LK. Serinc5 Restricts HIV Membrane Fusion by Altering Lipid Order and Heterogeneity in the Viral Membrane. ACS Infect Dis 2023; 9:773-784. [PMID: 36946615 PMCID: PMC10366416 DOI: 10.1021/acsinfecdis.2c00478] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The host restriction factor, Serinc5, incorporates into budding HIV particles and inhibits their infection by an incompletely understood mechanism. We have previously reported that Serinc5 but not its paralogue, Serinc2, blocks HIV cell entry by membrane fusion, specifically by inhibiting fusion pore formation and dilation. A body of work suggests that Serinc5 may alter the conformation and clustering of the HIV fusion protein, Env. To contribute an additional perspective to the developing model of Serinc5 restriction, we assessed Serinc2 and Serinc5's effects on HIV pseudoviral membranes. By measuring pseudoviral membrane thickness via cryo-electron microscopy and order via the fluorescent dye, FLIPPER-TR, Serinc5 was found to increase membrane heterogeneity, skewing the distribution toward a larger fraction of the viral membrane in an ordered phase. We also directly observed for the first time the coexistence of membrane domains within individual viral membrane envelopes. Using a total internal reflection fluorescence-based single particle fusion assay, we found that treatment of HIV pseudoviral particles with phosphatidylethanolamine (PE) rescued HIV pseudovirus fusion from restriction by Serinc5, which was accompanied by decreased membrane heterogeneity and order. This effect was specific for PE and did not depend on acyl chain length or saturation. Together, these data suggest that Serinc5 alters multiple interrelated properties of the viral membrane─lipid chain order, rigidity, line tension, and lateral pressure─which decrease the accessibility of fusion intermediates and disfavor completion of fusion. These biophysical insights into Serinc5 restriction of HIV infectivity could contribute to the development of novel antivirals that exploit the same weaknesses.
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Affiliation(s)
- Amanda E. Ward
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA 22908
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22908
| | - Daria Sokovikova
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA 22908
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22908
| | - Melvin Neal Waxham
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX 77030
| | | | - Ilya Levental
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA 22908
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22908
| | - Kandice R. Levental
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA 22908
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22908
| | - Volker Kiessling
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA 22908
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22908
| | - Judith M. White
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA 22908
| | - Lukas K. Tamm
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA 22908
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22908
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6
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Sukmarini L. Antiviral Peptides (AVPs) of Marine Origin as Propitious Therapeutic Drug Candidates for the Treatment of Human Viruses. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27092619. [PMID: 35565968 PMCID: PMC9101517 DOI: 10.3390/molecules27092619] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/03/2022] [Accepted: 04/18/2022] [Indexed: 12/13/2022]
Abstract
The marine environment presents a favorable avenue for potential therapeutic agents as a reservoir of new bioactive natural products. Due to their numerous potential pharmacological effects, marine-derived natural products—particularly marine peptides—have gained considerable attention. These peptides have shown a broad spectrum of biological functions, such as antimicrobial, antiviral, cytotoxic, immunomodulatory, and analgesic effects. The emergence of new virus strains and viral resistance leads to continuing efforts to develop more effective antiviral drugs. Interestingly, antimicrobial peptides (AMPs) that possess antiviral properties and are alternatively regarded as antiviral peptides (AVPs) demonstrate vast potential as alternative peptide-based drug candidates available for viral infection treatments. Hence, AVPs obtained from various marine organisms have been evaluated. This brief review features recent updates of marine-derived AVPs from 2011 to 2021. Moreover, the biosynthesis of this class of compounds and their possible mechanisms of action are also discussed. Selected peptides from various marine organisms possessing antiviral activities against important human viruses—such as human immunodeficiency viruses, herpes simplex viruses, influenza viruses, hepatitis C virus, and coronaviruses—are highlighted herein.
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Affiliation(s)
- Linda Sukmarini
- Research Center for Applied Microbiology, National Research and Innovation Agency (BRIN), Jl. Raya Bogor Km. 46, Cibinong 16911, West Java, Indonesia
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7
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SCD2-mediated monounsaturated fatty acid metabolism regulates cGAS-STING-dependent type I IFN responses in CD4 + T cells. Commun Biol 2021; 4:820. [PMID: 34188173 PMCID: PMC8242023 DOI: 10.1038/s42003-021-02310-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/03/2021] [Indexed: 12/11/2022] Open
Abstract
Host lipid metabolism and viral responses are intimately connected. However, the process by which the acquired immune systems adapts lipid metabolism to meet demands, and whether or not the metabolic rewiring confers a selective advantage to host immunity, remains unclear. Here we show that viral infection attenuates the expression of genes related to lipid metabolism in murine CD4+ T cells, which in turn increases the expression of antiviral genes. Inhibition of the fatty acid synthesis pathway substantially increases the basal expression of antiviral genes via the spontaneous production of type I interferon (IFN). Using a combination of CRISPR/Cas9-mediated genome editing technology and a global lipidomics analysis, we found that the decrease in monounsaturated fatty acid caused by genetic deletion of Scd2 in mice was crucial for the induction of an antiviral response through activation of the cGAS-STING pathway. These findings demonstrate the important relationship between fatty acid biosynthesis and type I IFN responses that enhances the antiviral response. Kanno et al. demonstrate that decreased monounsaturated fatty acid in CD4 + T cells following Scd2 deletion boosts the induction of the antiviral response via activation of the cGAS-STING pathway in mice. This study highlights the important interaction between fatty acid metabolism and the acquired immune response.
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8
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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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9
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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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10
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Tamalet C, Devaux C, Dubourg G, Colson P. Resistance to human immunodeficiency virus infection: a rare but neglected state. Ann N Y Acad Sci 2020; 1485:22-42. [PMID: 33009659 DOI: 10.1111/nyas.14452] [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: 04/15/2020] [Revised: 06/25/2020] [Accepted: 07/07/2020] [Indexed: 11/29/2022]
Abstract
The natural history of human immunodeficiency virus (HIV) infection is well understood. In most individuals sexually exposed to HIV, the risk of becoming infected depends on the viral load and on sexual practices and gender. However, a low percentage of individuals who practice frequent unprotected sexual intercourse with HIV-infected partners remain uninfected. Although the systematic study of these individuals has made it possible to identify HIV resistance factors including protective genetic patterns, such epidemiological situations remain paradoxical and not fully understood. In vitro experiments have demonstrated that peripheral blood mononuclear cells (PBMCs) from HIV-free, unexposed blood donors are not equally susceptible to HIV infection; in addition, PBMCs from highly exposed seronegative individuals are generally resistant to infection by primary HIV clinical isolates. We review the literature on permissiveness of PBMCs from healthy blood donors and uninfected hyperexposed individuals to sustained infection and replication of HIV-1 in vitro. In addition, we focus on recent evidence indicating that the gut microbiota may either contribute to natural resistance to or delay replication of HIV infected individuals.
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Affiliation(s)
- Catherine Tamalet
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Christian Devaux
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Gregory Dubourg
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Philippe Colson
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
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11
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Dadhich R, Kapoor S. Various Facets of Pathogenic Lipids in Infectious Diseases: Exploring Virulent Lipid-Host Interactome and Their Druggability. J Membr Biol 2020; 253:399-423. [PMID: 32833058 PMCID: PMC7443855 DOI: 10.1007/s00232-020-00135-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023]
Abstract
Lipids form an integral, structural, and functional part of all life forms. They play a significant role in various cellular processes such as membrane fusion, fission, endocytosis, protein trafficking, and protein functions. Interestingly, recent studies have revealed their more impactful and critical involvement in infectious diseases, starting with the manipulation of the host membrane to facilitate pathogenic entry. Thereafter, pathogens recruit specific host lipids for the maintenance of favorable intracellular niche to augment their survival and proliferation. In this review, we showcase the lipid-mediated host pathogen interplay in context of life-threatening viral and bacterial diseases including the recent SARS-CoV-2 infection. We evaluate the emergent lipid-centric approaches adopted by these pathogens, while delineating the alterations in the composition and organization of the cell membrane within the host, as well as the pathogen. Lastly, crucial nexus points in their interaction landscape for therapeutic interventions are identified. Lipids act as critical determinants of bacterial and viral pathogenesis by altering the host cell membrane structure and functions.
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Affiliation(s)
- Ruchika Dadhich
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India.
- Wadhwani Research Centre for Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
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12
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Rujas E, Insausti S, Leaman DP, Carravilla P, González-Resines S, Monceaux V, Sánchez-Eugenia R, García-Porras M, Iloro I, Zhang L, Elortza F, Julien JP, Saéz-Cirión A, Zwick MB, Eggeling C, Ojida A, Domene C, Caaveiro JMM, Nieva JL. Affinity for the Interface Underpins Potency of Antibodies Operating In Membrane Environments. Cell Rep 2020; 32:108037. [PMID: 32814041 PMCID: PMC7861656 DOI: 10.1016/j.celrep.2020.108037] [Citation(s) in RCA: 9] [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: 05/04/2020] [Revised: 07/02/2020] [Accepted: 07/23/2020] [Indexed: 11/29/2022] Open
Abstract
The contribution of membrane interfacial interactions to recognition of membrane-embedded antigens by antibodies is currently unclear. This report demonstrates the optimization of this type of antibodies via chemical modification of regions near the membrane but not directly involved in the recognition of the epitope. Using the HIV-1 antibody 10E8 as a model, linear and polycyclic synthetic aromatic compounds are introduced at selected sites. Molecular dynamics simulations predict the favorable interactions of these synthetic compounds with the viral lipid membrane, where the epitope of the HIV-1 glycoprotein Env is located. Chemical modification of 10E8 with aromatic acetamides facilitates the productive and specific recognition of the native antigen, partially buried in the crowded environment of the viral membrane, resulting in a dramatic increase of its capacity to block viral infection. These observations support the harnessing of interfacial affinity through site-selective chemical modification to optimize the function of antibodies that target membrane-proximal epitopes.
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Affiliation(s)
- Edurne Rujas
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain; Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Sara Insausti
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Daniel P Leaman
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Pablo Carravilla
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain; Institute of Applied Optics and Biophysics Friedrich-Schiller-University Jena, Max-Wien Platz 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
| | | | - Valérie Monceaux
- Institut Pasteur, Unité HIV Inflammation et Persistance, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Rubén Sánchez-Eugenia
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Miguel García-Porras
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Ibon Iloro
- Proteomics Platform, CIC bioGUNE, Parque Tecnológico de Vizcaya, 48160 Derio, Spain
| | - Lei Zhang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Félix Elortza
- Proteomics Platform, CIC bioGUNE, Parque Tecnológico de Vizcaya, 48160 Derio, Spain
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Immunology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Asier Saéz-Cirión
- Institut Pasteur, Unité HIV Inflammation et Persistance, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Michael B Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Christian Eggeling
- Institute of Applied Optics and Biophysics Friedrich-Schiller-University Jena, Max-Wien Platz 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Akio Ojida
- Department of Chemical Biology, School of Pharmaceutical Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Carmen Domene
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AX, UK; Department of Chemistry, University of Oxford, Oxford OX1 3TF, UK
| | - Jose M M Caaveiro
- Laboratory of Global Health Care, School of Pharmaceutical Sciences, Kyushu University, Fukuoka 819-0395, Japan.
| | - José L Nieva
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
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13
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Torralba J, de la Arada I, Carravilla P, Insausti S, Rujas E, Largo E, Eggeling C, Arrondo JLR, Apellániz B, Nieva JL. Cholesterol Constrains the Antigenic Configuration of the Membrane-Proximal Neutralizing HIV-1 Epitope. ACS Infect Dis 2020; 6:2155-2168. [PMID: 32584020 DOI: 10.1021/acsinfecdis.0c00243] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The envelope glycoprotein (Env) enables HIV-1 cell entry through fusion of host-cell and viral membranes induced by the transmembrane subunit gp41. Antibodies targeting the C-terminal sequence of the membrane-proximal external region (C-MPER) block the fusogenic activity of gp41 and achieve neutralization of divergent HIV-1 strains and isolates. Thus, recreating the structure that generates broadly neutralizing C-MPER antibodies during infection is a major goal in HIV vaccine development. Here, we have reconstituted a peptide termed CpreTM-TMD in a membrane environment. This peptide contains the C-MPER epitope and the minimum TMD residues required for the anchorage of the Env glycoprotein to the viral membrane. In addition, we have used antibody 10E8 variants to gauge the antigenic configuration attained by CpreTM-TMD as a function of the membrane cholesterol content, a functional determinant of the HIV envelope and liposome-based vaccines. Differential binding of the 10E8 variants and the trend of the IgG responses recovered from rabbits immunized with liposome-peptide formulations, suggested that cholesterol may restrict 10E8 accessibility to the C-MPER epitope. Our data ruled out the destabilization of the lipid bilayer architecture in CpreTM-TMD-containing membranes, and pointed to the perturbation of the helical conformation by lipid packing as the cause of the antigenic configuration loss induced by cholesterol. Overall, our results provide additional insights into the structural basis of the Env complex anchoring to membranes, and suggest new approaches to the design of effective immunogens directed against the near pan-neutralizing HIV-1 epitope C-MPER.
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Affiliation(s)
- Johana Torralba
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Igor de la Arada
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Pablo Carravilla
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Sara Insausti
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Edurne Rujas
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Eneko Largo
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Immunology, Microbiology and Parasitology, Medicine and Odontology Faculty, University of Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Christian Eggeling
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, OX3 9DS Oxford, U.K
| | - José L R Arrondo
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Beatriz Apellániz
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
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14
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Abstract
: Human CD300a is known to promote the infection by dengue and other enveloped viruses and is overexpressed on CD4 T cells from HIV-1-infected patients. We found that infected CD4+RA- T cells from untreated HIV-1-infected patients were mostly CD300a+. Furthermore, CD300a expressing CD4+RA- T cells from healthy donors were significantly more infected by HIV-1 in vitro than CD300a- cells. CD300a might represent a biomarker of susceptibility to HIV-1 infection on memory CD4 T lymphocytes.
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15
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Carravilla P, Nieva JL, Eggeling C. Fluorescence Microscopy of the HIV-1 Envelope. Viruses 2020; 12:E348. [PMID: 32245254 PMCID: PMC7150788 DOI: 10.3390/v12030348] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/18/2022] Open
Abstract
Human immunodeficiency virus (HIV) infection constitutes a major health and social issue worldwide. HIV infects cells by fusing its envelope with the target cell plasma membrane. This process is mediated by the viral Env glycoprotein and depends on the envelope lipid composition. Fluorescent microscopy has been employed to investigate the envelope properties, and the processes of viral assembly and fusion, but the application of this technique to the study of HIV is still limited by a number of factors, such as the small size of HIV virions or the difficulty to label the envelope components. Here, we review fluorescence imaging studies of the envelope lipids and proteins, focusing on labelling strategies and model systems.
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Affiliation(s)
- Pablo Carravilla
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany;
- Leibniz Institute of Photonic Technology, Albert Einstein Strasse 9, 07743 Jena, Germany
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain;
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, E-48940 Leioa, Spain
| | - José L. Nieva
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain;
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, E-48940 Leioa, Spain
| | - Christian Eggeling
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany;
- Leibniz Institute of Photonic Technology, Albert Einstein Strasse 9, 07743 Jena, Germany
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
- Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, 07743 Jena, Germany
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16
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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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17
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Adhyapak P, Srivatsav AT, Mishra M, Singh A, Narayan R, Kapoor S. Dynamical Organization of Compositionally Distinct Inner and Outer Membrane Lipids of Mycobacteria. Biophys J 2020; 118:1279-1291. [PMID: 32061274 DOI: 10.1016/j.bpj.2020.01.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 01/20/2020] [Accepted: 01/23/2020] [Indexed: 12/21/2022] Open
Abstract
Mycobacterium species, including Mycobacterium tuberculosis, employs atypical long (C60-90) and branched lipids to produce a complex cell wall and localizes these toward distinct spatial locations, inner membrane (IM) and outer membrane (OM), thus forming a robust permeability barrier. The properties and functional roles of these spatially orchestrated membrane platforms remain unknown. Herein, we report the distinctive lateral organization, fluidity, and lipid domain architecture of protein-free membranes reconstituted from IM and OM lipids in vitro from M. smegmatis (Msm) underscored by their lipid packing and lipid dynamics. We show that Msm OM, against common notion, is more dynamic and fluid compared with IM and reveal the role of cell wall-associated peptidoglycans and lipoarabinomannan on the Msm OM organization. Overall, these studies indicate that mycobacterial species may regulate their overall membrane functionality by regulating the synthesis of these complex arrays of lipids. Based on the structure-function relationship drawn here, documented alteration in the mycobacterial lipidome during cellular infection and/or drug treatment could reflect a mechanism to fine-tune M. tuberculosis membrane properties to its advantage. These findings are expected to inspire development of lipid-centric therapeutic approaches targeted toward its membrane.
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Affiliation(s)
- Pranav Adhyapak
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Aswin T Srivatsav
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Manjari Mishra
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Abhishek Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Rishikesh Narayan
- School of Chemical and Biological Sciences, Indian Institute of Technology Goa, Goa, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India; Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
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18
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Labyrinthopeptins Exert Broad-Spectrum Antiviral Activity through Lipid-Binding-Mediated Virolysis. J Virol 2020; 94:JVI.01471-19. [PMID: 31666384 DOI: 10.1128/jvi.01471-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/23/2019] [Indexed: 12/31/2022] Open
Abstract
To counteract the serious health threat posed by known and novel viral pathogens, drugs that target a variety of viruses through a common mechanism have attracted recent attention due to their potential in treating (re)emerging infections, for which direct-acting antivirals are not available. We found that labyrinthopeptins A1 and A2, the prototype congeners of carbacyclic lanthipeptides, inhibit the proliferation of diverse enveloped viruses, including dengue virus, Zika virus, West Nile virus, hepatitis C virus, chikungunya virus, Kaposi's sarcoma-associated herpesvirus, cytomegalovirus, and herpes simplex virus, in the low micromolar to nanomolar range. Mechanistic studies on viral particles revealed that labyrinthopeptins induce a virolytic effect through binding to the viral membrane lipid phosphatidylethanolamine (PE). These effects are enhanced by a combined equimolar application of both labyrinthopeptins, and a clear synergism was observed across a concentration range corresponding to 10% to 90% inhibitory concentrations of the compounds. Time-resolved experiments with large unilamellar vesicles (LUVs) reveal that membrane lipid raft compositions (phosphatidylcholine [PC]/PE/cholesterol/sphingomyelin at 17:10:33:40) are particularly sensitive to labyrinthopeptins in comparison to PC/PE (90:10) LUVs, even though the overall PE amount remains constant. Labyrinthopeptins exhibited low cytotoxicity and had favorable pharmacokinetic properties in mice (half-life [t 1/2] = 10.0 h), which designates them promising antiviral compounds acting by an unusual viral lipid targeting mechanism.IMPORTANCE For many viral infections, current treatment options are insufficient. Because the development of each antiviral drug is time-consuming and expensive, the prospect of finding broad-spectrum antivirals that can fight multiple, diverse viruses-well-known viruses as well as (re)emerging species-has gained attention, especially for the treatment of viral coinfections. While most known broad-spectrum agents address processes in the host cell, we found that targeting lipids of the free virus outside the host cell with the natural products labyrinthopeptin A1 and A2 is a viable strategy to inhibit the proliferation of a broad range of viruses from different families, including chikungunya virus, dengue virus, Zika virus, Kaposi's sarcoma-associated herpesvirus, and cytomegalovirus. Labyrinthopeptins bind to viral phosphatidylethanolamine and induce virolysis without exerting cytotoxicity on host cells. This represents a novel and unusual mechanism to tackle medically relevant viral infections.
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19
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Single-molecule imaging of HIV-1 envelope glycoprotein dynamics and Gag lattice association exposes determinants responsible for virus incorporation. Proc Natl Acad Sci U S A 2019; 116:25269-25277. [PMID: 31757854 PMCID: PMC6911212 DOI: 10.1073/pnas.1910008116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) is sparsely incorporated onto assembling virus particles on the host cell plasma membrane in order for the virus to balance infectivity and evade the immune response. Env becomes trapped in a nascent particle on encounter with the polymeric viral protein Gag, which forms a dense protein lattice on the inner leaflet of the plasma membrane. While Env incorporation efficiency is readily measured biochemically from released particles, very little is known about the spatiotemporal dynamics of Env trapping events. Herein, we demonstrate, via high-resolution single-molecule tracking, that retention of Env trimers within single virus assembly sites requires the Env cytoplasmic tail (CT) and the L12 residue in the matrix (MA) domain of Gag but does not require curvature of the viral lattice. We further demonstrate that Env trimers are confined to subviral regions of a budding Gag lattice, supporting a model where direct interactions and/or steric corralling between the Env-CT and a lattice of MA trimers promote Env trapping and infectious HIV-1 assembly.
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20
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Carravilla P, Darré L, Oar-Arteta IR, Vesga AG, Rujas E, de Las Heras-Martínez G, Domene C, Nieva JL, Requejo-Isidro J. The Bilayer Collective Properties Govern the Interaction of an HIV-1 Antibody with the Viral Membrane. Biophys J 2019; 118:44-56. [PMID: 31787208 DOI: 10.1016/j.bpj.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 01/15/2023] Open
Abstract
Efficient engagement with the envelope glycoprotein membrane-proximal external region (MPER) results in robust blocking of viral infection by a class of broadly neutralizing antibodies (bnAbs) against human immunodeficiency virus (HIV). Developing an accommodation surface that engages with the viral lipid envelope appears to correlate with the neutralizing potency displayed by these bnAbs. The nature of the interactions established between the antibody and the lipid is nonetheless a matter of debate, with some authors arguing that anti-MPER specificity arises only under pathological conditions in autoantibodies endowed with stereospecific binding sites for phospholipids. However, bnAb-lipid interactions are often studied in systems that do not fully preserve the biophysical properties of lipid bilayers, and therefore, questions on binding specificity and the effect of collective membrane properties on the interaction are still open. Here, to evaluate the specificity of lipid interactions of an anti-MPER bnAb (4E10) in an intact membrane context, we determine quantitatively its association with lipid bilayers by means of scanning fluorescence correlation spectroscopy and all-atom molecular dynamic simulations. Our data support that 4E10 establishes electrostatic and hydrophobic interactions with the viral membrane surface and that the collective physical properties of the lipid bilayer influence 4E10 dynamics therein. We conclude that establishment of peripheral, nonspecific electrostatic interactions with the viral membrane through accommodation surfaces may assist high-affinity binding of HIV-1 MPER epitope at membrane interfaces. These findings highlight the importance of considering antibody-lipid interactions in the design of antibody-based anti-HIV strategies.
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Affiliation(s)
- Pablo Carravilla
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain; Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Jena, Germany
| | - Leonardo Darré
- Functional Genomics Laboratory & Biomolecular Simulations Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Itziar R Oar-Arteta
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Arturo G Vesga
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Edurne Rujas
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | | | - Carmen Domene
- Department of Chemistry, University of Bath, Claverton Down, Bath, United Kingdom; Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Jose L Nieva
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
| | - Jose Requejo-Isidro
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Centro Nacional de Biotecnología, CSIC, Madrid, Spain; Unidad de Nanobiotecnología, CNB-CSIC-IMDEA Nanociencia Associated Unit, Madrid, Spain.
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21
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Gomes B, Sanna G, Madeddu S, Hollmann A, Santos NC. Combining 25-Hydroxycholesterol with an HIV Fusion Inhibitor Peptide: Interaction with Biomembrane Model Systems and Human Blood Cells. ACS Infect Dis 2019; 5:582-591. [PMID: 30816690 DOI: 10.1021/acsinfecdis.8b00321] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The fusion between the viral and the target cell membrane is a crucial step in the life cycle of enveloped viruses. The blocking of this process is a well-known therapeutic approach that led to the development of the fusion inhibitor peptide enfuvirtide, clinically used against human immunodeficiency virus (HIV) type 1. Despite this significant advance on viral treatment, the appearance of resistance has limited its clinical use. Such a limitation has led to the development of other fusion inhibitor peptides, such as C34, that present the same structural domain as enfuvirtide (heptad repeat sequence) but have different functional domains (pocket-binding domain in the case of C34 and lipid-binding domain in the case of enfuvirtide). Recently, the antiviral properties of 25-hydroxycholesterol were demonstrated, which boosted the interest in this oxysterol. The combination of two distinct antiviral molecules, C34 and 25-hydroxycholesterol, may help to suppress the emergence of resistant viruses. In this work, we characterized the interaction of the C34-25-hydroxycholesterol conjugate with biomembrane model systems and human blood cells. Lipid vesicles and monolayers with defined lipid compositions were used as biomembrane model systems. The conjugate interacts preferentially with membranes rich in sphingomyelin (a lipid enriched in lipid rafts) and presents a poor partition to membranes composed solely of phosphatidylcholine and cholesterol. We hypothesize that cholesterol causes a repulsive effect that is overcome in the presence of sphingomyelin. Importantly, the peptide shows a preference for human peripheral blood mononuclear cells relative to erythrocytes, which shows its potential to target CD4+ cells. Antiviral activity results against different wild-type and drug-resistant HIV strains further demonstrated the potential of C34-HC as a good candidate for future studies.
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Affiliation(s)
- Bárbara Gomes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Giusepinna Sanna
- Department of Biomedical Sciences, Section of Microbiology and Virology, University of Cagliary, Cagliari 09123, Italy
| | - Silvia Madeddu
- Department of Biomedical Sciences, Section of Microbiology and Virology, University of Cagliary, Cagliari 09123, Italy
| | - Axel Hollmann
- Laboratory of Bioactive Compounds, CIBAAL−University of Santiago del Estero and CONICET, Santiago del Estero, Argentina
- Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, University of Quilmes, Bernal B1876BXD, Argentina
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
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22
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Peptide Assembly on the Membrane Determines the HIV-1 Inhibitory Activity of Dual-Targeting Fusion Inhibitor Peptides. Sci Rep 2019; 9:3257. [PMID: 30824796 PMCID: PMC6397244 DOI: 10.1038/s41598-019-40125-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/08/2019] [Indexed: 12/31/2022] Open
Abstract
Novel strategies in the design of HIV-1 fusion/entry inhibitors are based on the construction of dual-targeting fusion proteins and peptides with synergistic antiviral effects. In this work we describe the design of dual-targeting peptides composed of peptide domains of E2 and E1 envelope proteins from Human Pegivirus with the aim of targeting both the loop region and the fusion peptide domains of HIV-1 gp41. In a previous work, we described the inhibitory role of a highly conserved fragment of the E1 protein (domain 139–156) which interacts with the HIV-1 fusion peptide at the membrane level. Here, two different dual-targeting peptides, where this E1 peptide is located on the N- or the C-terminus respectively, have been chemically synthesized and their antiviral activities have been evaluated with HIV pseudotyped viruses from different clades. The study of the functional behaviour of peptides in a membranous environment attending to the peptide recognition of the target sites on gp41, the peptide conformation as well as the peptide affinity to the membrane, demonstrate that antiviral activity of the dual-targeting peptides is directly related to the peptide affinity and its subsequent assembly into the model membrane. The overall results point out to the necessity that fusion inhibitor peptides that specifically interfere with the N-terminal region of gp41 are embedded within the membrane in order to properly interact with their viral target.
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23
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Gerlach SL, Chandra PK, Roy U, Gunasekera S, Göransson U, Wimley WC, Braun SE, Mondal D. The Membrane-Active Phytopeptide Cycloviolacin O2 Simultaneously Targets HIV-1-infected Cells and Infectious Viral Particles to Potentiate the Efficacy of Antiretroviral Drugs. MEDICINES 2019; 6:medicines6010033. [PMID: 30823453 PMCID: PMC6473583 DOI: 10.3390/medicines6010033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/22/2019] [Accepted: 02/24/2019] [Indexed: 12/25/2022]
Abstract
Background: Novel strategies to increase the efficacy of antiretroviral (ARV) drugs will be of crucial importance. We hypothesize that membranes of HIV-1-infected cells and enveloped HIV-1 particles may be preferentially targeted by the phytopeptide, cycloviolacin O2 (CyO2) to significantly enhance ARV efficacy. Methods: Physiologically safe concentrations of CyO2 were determined via red blood cell (RBC) hemolysis. SYTOX-green dye-uptake and radiolabeled saquinavir (³H-SQV) uptake assays were used to measure pore-formation and drug uptake, respectively. ELISA, reporter assays and ultracentrifugation were conducted to analyze the antiviral efficacy of HIV-1 protease and fusion inhibitors alone and co-exposed to CyO2. Results: CyO2 concentrations below 0.5 μM did not show substantial hemolytic activity, yet these concentrations enabled rapid pore-formation in HIV-infected T-cells and monocytes and increased drug uptake. ELISA for HIV-1 p24 indicated that CyO2 enhances the antiviral efficacy of both SQV and nelfinavir. CyO2 (< 0.5 μM) alone decreases HIV-1 p24 production, but it did not affect the transcription regulatory function of the HIV-1 long terminal repeat (LTR). Ultracentrifugation studies clearly showed that CyO2 exposure disrupted viral integrity and decreased the p24 content of viral particles. Furthermore, direct HIV-1 inactivation by CyO2 enhanced the efficacy of enfuvirtide. Conclusions: The membrane-active properties of CyO2 may help suppress viral load and augment antiretroviral drug efficacy.
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Affiliation(s)
- Samantha L Gerlach
- Department of Biology, Division of Science, Technology, Engineering and Mathematics, Dillard University, New Orleans, LA 70122, USA.
- Department of Pharmacology, Tulane University Medical Center, New Orleans, LA 70112, USA.
| | - Partha K Chandra
- Department of Pharmacology, Tulane University Medical Center, New Orleans, LA 70112, USA.
| | - Upal Roy
- Department of Health and Biomedical Sciences, University of Texas Rio Grande Valley, Brownsville, TX 78520, USA.
| | - Sunithi Gunasekera
- Department of Medicinal Chemistry, Uppsala University, 751 23 Uppsala, Sweden.
| | - Ulf Göransson
- Department of Medicinal Chemistry, Uppsala University, 751 23 Uppsala, Sweden.
| | - William C Wimley
- Department of Biochemistry and Molecular Biology, Tulane University Medical Center, New Orleans, LA 70112, USA.
| | - Stephen E Braun
- Tulane National Primate Research Center, Covington, LA 70112, USA.
| | - Debasis Mondal
- Department of Pharmacology, Tulane University Medical Center, New Orleans, LA 70112, USA.
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24
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Histidine-Rich Glycoprotein Inhibits HIV-1 Infection in a pH-Dependent Manner. J Virol 2019; 93:JVI.01749-18. [PMID: 30518643 DOI: 10.1128/jvi.01749-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/13/2018] [Indexed: 01/27/2023] Open
Abstract
Histidine-rich glycoprotein (HRG) is an abundant plasma protein with a multidomain structure, allowing its interaction with many ligands, including phospholipids, plasminogen, fibrinogen, IgG antibodies, and heparan sulfate. HRG has been shown to regulate different biological responses, such as angiogenesis, coagulation, and fibrinolysis. Here, we found that HRG almost completely abrogated the infection of Ghost cells, Jurkat cells, CD4+ T cells, and macrophages by HIV-1 at a low pH (range, 6.5 to 5.5) but not at a neutral pH. HRG was shown to interact with the heparan sulfate expressed by target cells, inhibiting an early postbinding step associated with HIV-1 infection. More importantly, by acting on the viral particle itself, HRG induced a deleterious effect, which reduces viral infectivity. Because cervicovaginal secretions in healthy women show low pH values, even after semen deposition, our observations suggest that HRG might represent a constitutive defense mechanism in the vaginal mucosa. Of note, low pH also enabled HRG to inhibit the infection of HEp-2 cells and Vero cells by respiratory syncytial virus (RSV) and herpes simplex virus 2 (HSV-2), respectively, suggesting that HRG might display broad antiviral activity under acidic conditions.IMPORTANCE Vaginal intercourse represents a high-risk route for HIV-1 transmission. The efficiency of male-to-female HIV-1 transmission has been estimated to be 1 in every 1,000 episodes of sexual intercourse, reflecting the high degree of protection conferred by the genital mucosa. However, the contribution of different host factors to the protection against HIV-1 at mucosal surfaces remains poorly defined. Here, we report for the first time that acidic values of pH enable the plasma protein histidine-rich glycoprotein (HRG) to strongly inhibit HIV-1 infection. Because cervicovaginal secretions usually show low pH values, our observations suggest that HRG might represent a constitutive antiviral mechanism in the vaginal mucosa. Interestingly, infection by other viruses, such as respiratory syncytial virus and herpes simplex virus 2, was also markedly inhibited by HRG at low pH values, suggesting that extracellular acidosis enables HRG to display broad antiviral activity.
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25
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Carravilla P, Chojnacki J, Rujas E, Insausti S, Largo E, Waithe D, Apellaniz B, Sicard T, Julien JP, Eggeling C, Nieva JL. Molecular recognition of the native HIV-1 MPER revealed by STED microscopy of single virions. Nat Commun 2019; 10:78. [PMID: 30622256 PMCID: PMC6325134 DOI: 10.1038/s41467-018-07962-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 12/07/2018] [Indexed: 11/09/2022] Open
Abstract
Antibodies against the Membrane-Proximal External Region (MPER) of the Env gp41 subunit neutralize HIV-1 with exceptional breadth and potency. Due to the lack of knowledge on the MPER native structure and accessibility, different and exclusive models have been proposed for the molecular mechanism of MPER recognition by broadly neutralizing antibodies. Here, accessibility of antibodies to the native Env MPER on single virions has been addressed through STED microscopy. STED imaging of fluorescently labeled Fabs reveals a common pattern of native Env recognition for HIV-1 antibodies targeting MPER or the surface subunit gp120. In the case of anti-MPER antibodies, the process evolves with extra contribution of interactions with the viral lipid membrane to binding specificity. Our data provide biophysical insights into the recognition of the potent and broadly neutralizing MPER epitope on HIV virions, and as such is of importance for the design of therapeutic interventions.
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Affiliation(s)
- Pablo Carravilla
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Jakub Chojnacki
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Edurne Rujas
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Sara Insausti
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Eneko Largo
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Dominic Waithe
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Beatriz Apellaniz
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Taylor Sicard
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Department of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK.
- Institute of Applied Optics Friedrich-Schiller-University Jena, Max-Wien Platz 4, 07743, Jena, Germany.
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745, Jena, Germany.
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
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26
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Urbančič I, Brun J, Shrestha D, Waithe D, Eggeling C, Chojnacki J. Lipid Composition but Not Curvature Is the Determinant Factor for the Low Molecular Mobility Observed on the Membrane of Virus-Like Vesicles. Viruses 2018; 10:v10080415. [PMID: 30096847 PMCID: PMC6116177 DOI: 10.3390/v10080415] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/03/2018] [Accepted: 08/07/2018] [Indexed: 12/14/2022] Open
Abstract
Human Immunodeficiency Virus type-1 (HIV-1) acquires its lipid membrane from the plasma membrane of the infected cell from which it buds out. Previous studies have shown that the HIV-1 envelope is an environment of very low mobility, with the diffusion of incorporated proteins two orders of magnitude slower than in the plasma membrane. One of the reasons for this difference is thought to be the HIV-1 membrane composition that is characterised by a high degree of rigidity and lipid packing, which has, until now, been difficult to assess experimentally. To further refine the model of the molecular mobility on the HIV-1 surface, we herein investigated the relative importance of membrane composition and curvature in simplified model membrane systems, large unilamellar vesicles (LUVs) of different lipid compositions and sizes (0.1–1 µm), using super-resolution stimulated emission depletion (STED) microscopy-based fluorescence correlation spectroscopy (STED-FCS). Establishing an approach that is also applicable to measurements of molecule dynamics in virus-sized particles, we found, at least for the 0.1–1 µm sized vesicles, that the lipid composition and thus membrane rigidity, but not the curvature, play an important role in the decreased molecular mobility on the vesicles’ surface. This observation suggests that the composition of the envelope rather than the particle geometry contributes to the previously described low mobility of proteins on the HIV-1 surface. Our vesicle-based study thus provides further insight into the dynamic properties of the surface of individual HIV-1 particles, as well as paves the methodological way towards better characterisation of the properties and function of viral lipid envelopes in general.
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Affiliation(s)
- Iztok Urbančič
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
- "Jožef Stefan" Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia.
| | - Juliane Brun
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Dilip Shrestha
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Dominic Waithe
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Christian Eggeling
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
- Institute of Applied Optics, Friedrich-Schiller-University Jena, Max-Wien Platz 4, 07743 Jena, Germany.
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany.
| | - Jakub Chojnacki
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
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27
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Gullberg RC, Steel JJ, Pujari V, Rovnak J, Crick DC, Perera R. Stearoly-CoA desaturase 1 differentiates early and advanced dengue virus infections and determines virus particle infectivity. PLoS Pathog 2018; 14:e1007261. [PMID: 30118512 PMCID: PMC6114894 DOI: 10.1371/journal.ppat.1007261] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 08/29/2018] [Accepted: 08/06/2018] [Indexed: 02/04/2023] Open
Abstract
Positive strand RNA viruses, such as dengue virus type 2 (DENV2) expand and structurally alter ER membranes to optimize cellular communication pathways that promote viral replicative needs. These complex rearrangements require significant protein scaffolding as well as changes to the ER chemical composition to support these structures. We have previously shown that the lipid abundance and repertoire of host cells are significantly altered during infection with these viruses. Specifically, enzymes in the lipid biosynthesis pathway such as fatty acid synthase (FAS) are recruited to viral replication sites by interaction with viral proteins and displayed enhanced activities during infection. We have now identified that events downstream of FAS (fatty acid desaturation) are critical for virus replication. In this study we screened enzymes in the unsaturated fatty acid (UFA) biosynthetic pathway and found that the rate-limiting enzyme in monounsaturated fatty acid biosynthesis, stearoyl-CoA desaturase 1 (SCD1), is indispensable for DENV2 replication. The enzymatic activity of SCD1, was required for viral genome replication and particle release, and it was regulated in a time-dependent manner with a stringent requirement early during viral infection. As infection progressed, SCD1 protein expression levels were inversely correlated with the concentration of viral dsRNA in the cell. This modulation of SCD1, coinciding with the stage of viral replication, highlighted its function as a trigger of early infection and an enzyme that controlled alternate lipid requirements during early versus advanced infections. Loss of function of this enzyme disrupted structural alterations of assembled viral particles rendering them non-infectious and immature and defective in viral entry. This study identifies the complex involvement of SCD1 in DENV2 infection and demonstrates that these viruses alter ER lipid composition to increase infectivity of the virus particles.
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Affiliation(s)
- Rebekah C. Gullberg
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States of America
| | - J. Jordan Steel
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States of America
| | - Venugopal Pujari
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States of America
| | - Joel Rovnak
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States of America
| | - Dean C. Crick
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States of America
| | - Rushika Perera
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States of America
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28
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Molotkovsky RJ, Alexandrova VV, Galimzyanov TR, Jiménez-Munguía I, Pavlov KV, Batishchev OV, Akimov SA. Lateral Membrane Heterogeneity Regulates Viral-Induced Membrane Fusion during HIV Entry. Int J Mol Sci 2018; 19:ijms19051483. [PMID: 29772704 PMCID: PMC5983600 DOI: 10.3390/ijms19051483] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/08/2018] [Accepted: 05/14/2018] [Indexed: 11/16/2022] Open
Abstract
Sphingomyelin- and cholesterol- enriched membrane domains, commonly referred to as “rafts” play a crucial role in a large number of intra- and intercellular processes. Recent experiments suggest that not only the volumetric inhomogeneity of lipid distribution in rafts, but also the arrangement of the 1D boundary between the raft and the surrounding membrane is important for the membrane-associated processes. The reason is that the boundary preferentially recruits different peptides, such as HIV (human immunodeficiency virus) fusion peptide. In the present work, we report a theoretical investigation of mechanisms of influence of the raft boundary arrangement upon virus-induced membrane fusion. We theoretically predict that the raft boundary can act as an attractor for viral fusion peptides, which preferentially distribute into the vicinity of the boundary, playing the role of ‘line active components’ of the membrane (‘linactants’). We have calculated the height of the fusion energy barrier and demonstrated that, in the case of fusion between HIV membrane and the target cell, presence of the raft boundary in the vicinity of the fusion site facilitates fusion. The results we obtained can be further generalized to be applicable to other enveloped viruses.
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Affiliation(s)
- Rodion J Molotkovsky
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
| | - Veronika V Alexandrova
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, 119991 Moscow, Russia.
| | - Timur R Galimzyanov
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
- Department of Theoretical Physics and Quantum Technologies, National University of Science and Technology "MISiS", 4 Leninskiy Prospekt, 119049 Moscow, Russia.
| | - Irene Jiménez-Munguía
- Department of Engineering of Technological Equipment, National University of Science and Technology "MISiS", 4 Leninskiy Prospekt, 119049 Moscow, Russia.
| | - Konstantin V Pavlov
- Laboratory of Electrophysiology, Federal Clinical Center of Physical-Chemical Medicine of FMBA, 1a Malaya Pirogovskaya Street, 119435 Moscow, Russia.
| | - Oleg V Batishchev
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
- Department of Physics of Living Systems, Moscow Institute of Physics and Technology (State University), 9 Institutskiy Lane, Dolgoprudniy, 141700 Moscow Region, Russia.
| | - Sergey A Akimov
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.
- Department of Theoretical Physics and Quantum Technologies, National University of Science and Technology "MISiS", 4 Leninskiy Prospekt, 119049 Moscow, Russia.
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29
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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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30
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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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31
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Carravilla P, Nieva JL. HIV antivirals: targeting the functional organization of the lipid envelope. Future Virol 2018. [DOI: 10.2217/fvl-2017-0114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Most of the surface of the lipid bilayer covering the human immunodeficiency virus type 1 (HIV-1) particle is directly accessible from the aqueous medium. Its peculiar chemical composition and physical properties appear to be critical for infection and, therefore, may comprise a target for selective antiviral activity. The HIV-1 membrane is enriched in raft-type lipids and also displays aminophospholipids on its external leaflet. We contend here that a great deal of membrane-active compounds described to block HIV-1 infection can do so by following a common mechanism of action: alteration of the lateral heterogeneity that supports the functional organization of the lipid envelope. The confirmation of this hypothesis could lay new foundations for the rational development of compounds with anti-HIV activity.
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Affiliation(s)
- Pablo Carravilla
- Biofisika Institute (CSIC, UPV/EHU) & Department of Biochemistry & Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU) & Department of Biochemistry & Molecular Biology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
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32
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Chojnacki J, Waithe D, Carravilla P, Huarte N, Galiani S, Enderlein J, Eggeling C. Envelope glycoprotein mobility on HIV-1 particles depends on the virus maturation state. Nat Commun 2017; 8:545. [PMID: 28916807 PMCID: PMC5601426 DOI: 10.1038/s41467-017-00515-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 06/30/2017] [Indexed: 12/02/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) assembles as immature particles, which require the proteolytic cleavage of structural polyprotein Gag and the clustering of envelope glycoprotein Env for infectivity. The details of mechanisms underlying Env clustering remain unknown. Here, we determine molecular dynamics of Env on the surface of individual HIV-1 particles using scanning fluorescence correlation spectroscopy on a super-resolution STED microscope. We find that Env undergoes a maturation-induced increase in mobility, highlighting diffusion as one cause for Env clustering. This mobility increase is dependent on Gag-interacting Env tail but not on changes in viral envelope lipid order. Diffusion of Env and other envelope incorporated proteins in mature HIV-1 is two orders of magnitude slower than in the plasma membrane, indicating that HIV-1 envelope is intrinsically a low mobility environment, mainly due to its general high lipid order. Our results provide insights into dynamic properties of proteins on the surface of individual virus particles.To become infectious, HIV-1 particles undergo a maturation process involving the clustering of envelope glycoprotein Env. Here, Chojnacki et al. employ super-resolution STED-FCS microscopy to study dynamics of Env molecules on HIV-1 particles and show that Env undergoes a maturation-induced increase in mobility.
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Affiliation(s)
- Jakub Chojnacki
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, Oxford, UK.
| | - Dominic Waithe
- Wolfson Imaging Centre, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, Oxford, UK
| | - Pablo Carravilla
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Nerea Huarte
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Silvia Galiani
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, Oxford, UK
| | - Jörg Enderlein
- Third Institute of Physics, Georg August University, 37077, Göttingen, Germany
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS, Oxford, UK.
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33
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Carravilla P, Cruz A, Martin-Ugarte I, Oar-Arteta IR, Torralba J, Apellaniz B, Pérez-Gil J, Requejo-Isidro J, Huarte N, Nieva JL. Effects of HIV-1 gp41-Derived Virucidal Peptides on Virus-like Lipid Membranes. Biophys J 2017; 113:1301-1310. [PMID: 28797705 DOI: 10.1016/j.bpj.2017.06.061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 06/22/2017] [Accepted: 06/29/2017] [Indexed: 12/11/2022] Open
Abstract
Membrane fusion induced by the envelope glycoprotein enables the intracellular replication of HIV-1; hence, this process constitutes a major target for antiretroviral compounds. It has been proposed that peptides having propensity to interact with membrane interfaces might exert broad antiviral activity against enveloped viruses. To test this hypothesis, in this contribution we have analyzed the antiviral effects of peptides derived from the membrane-proximal external region and the transmembrane domain of the envelope glycoprotein subunit gp41, which display different degrees of interfacial hydrophobicity. Our data support the virucidal activity of a region that combines hydrophobic-at-interface membrane-proximal external region aromatics with hydrophobic residues of the transmembrane domain, and contains the absolutely conserved 679LWYIK/R683 sequence, proposed to embody a "cholesterol recognition/interaction amino acid consensus" motif. We further sought to correlate the antiviral activity of these peptides and their effects on membranes that mimic lipid composition and biophysical properties of the viral envelope. The data revealed that peptides endowed with virucidal activity were membrane active and induced permeabilization and fusion of virus-like lipid vesicles. In addition, they modulated lipid packing and miscibility of laterally segregated liquid domains, two properties that depend on the high cholesterol content of the viral membrane. Thus, the overall experimental evidence is consistent with a pattern of HIV inhibition that involves direct alteration of the physical chemistry of the virus membrane. Furthermore, the sequence-dependent effects observed might guide the development of new virucidal peptides.
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Affiliation(s)
- Pablo Carravilla
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Antonio Cruz
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Itziar Martin-Ugarte
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Itziar R Oar-Arteta
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Johanna Torralba
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Beatriz Apellaniz
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - José Requejo-Isidro
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Nerea Huarte
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
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34
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Sims B, Farrow AL, Williams SD, Bansal A, Krendelchtchikov A, Gu L, Matthews QL. Role of TIM-4 in exosome-dependent entry of HIV-1 into human immune cells. Int J Nanomedicine 2017; 12:4823-4833. [PMID: 28740388 PMCID: PMC5505621 DOI: 10.2147/ijn.s132762] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Exosomes, 30–200 nm nanostructures secreted from donor cells and internalized by recipient cells, can play an important role in the cellular entry of some viruses. These microvesicles are actively secreted into various body fluids, including blood, urine, saliva, cerebrospinal fluid, and breast milk. We successfully isolated exosomes from human breast milk and plasma. The size and concentration of purified exosomes were measured by nanoparticle tracking, while Western blotting confirmed the presence of the exosomal-associated proteins CD9 and CD63, clathrin, and T cell immunoglobulin and mucin proteins (TIMs). Through viral infection assays, we determined that HIV-1 utilizes an exosome-dependent mechanism for entry into human immune cells. The virus contains high amounts of phosphatidylserine (PtdSer) and may bind PtdSer receptors, such as TIMs. This mechanism is supported by our findings that exosomes from multiple sources increased HIV-1 entry into T cells and macrophages, and viral entry was potently blocked with anti-TIM-4 antibodies.
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Affiliation(s)
- Brian Sims
- Division of Neonatology, Department of Pediatrics.,Department of Cell, Developmental and Integrative Biology.,Center for AIDS Research
| | | | - Sparkle D Williams
- Division of Neonatology, Department of Pediatrics.,Department of Cell, Developmental and Integrative Biology
| | | | - Alexandre Krendelchtchikov
- Division of Neonatology, Department of Pediatrics.,Department of Cell, Developmental and Integrative Biology.,Division of Infectious Diseases
| | - Linlin Gu
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham
| | - Qiana L Matthews
- Center for AIDS Research.,Division of Infectious Diseases.,Microbiology Program, Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, USA
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35
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Rujas E, Insausti S, García-Porras M, Sánchez-Eugenia R, Tsumoto K, Nieva JL, Caaveiro JMM. Functional Contacts between MPER and the Anti-HIV-1 Broadly Neutralizing Antibody 4E10 Extend into the Core of the Membrane. J Mol Biol 2017; 429:1213-1226. [PMID: 28300601 DOI: 10.1016/j.jmb.2017.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 12/18/2022]
Abstract
The exceptional breadth of broadly neutralizing antibodies (bNAbs) against the membrane-proximal external region (MPER) of the transmembrane protein gp41 makes this class of antibodies an ideal model to design HIV vaccines. From a practical point of view, however, the preparation of vaccines eliciting bNAbs is still a major roadblock that limits their clinical application. Fresh mechanistic insights are necessary to develop more effective strategies. In particular, the function of the unusually long complementarity-determining region three of the heavy chain (CDRH3) of 4E10, an anti-MPER bNAb, is an open question that fascinates researchers in the field. Residues comprising the apex region are dispensable for engagement of the epitope in solution; still, their single mutation profoundly impairs the neutralization capabilities of the antibody. Since this region is very hydrophobic, it has been proposed that the apex is essential for anchoring the antibody to the viral membrane where MPER resides. Herein, we have critically examined this idea using structural, biophysical, biochemical, and cell-based approaches. Our results demonstrate that the apex region is not just a "greasy" spot merely increasing the affinity of the antibody for the membrane. We demonstrate the three-dimensional engagement of the apex region of the CDRH3 with the conglomerate of gp41 epitope and membrane lipids as a means of effective binding and neutralization of the virus. This mechanism of recognition suggests a standard route of antibody ontogeny. Therefore, we need to focus our efforts on recreating a more realistic MPER/lipid immunogen in order to generate more effective anti-HIV-1 vaccines.
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Affiliation(s)
- Edurne Rujas
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, Bilbao 48080, Spain; Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Sara Insausti
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, Bilbao 48080, Spain
| | - Miguel García-Porras
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, Bilbao 48080, Spain
| | - Rubén Sánchez-Eugenia
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, Bilbao 48080, Spain
| | - Kouhei Tsumoto
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, Bilbao 48080, Spain.
| | - Jose M M Caaveiro
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan; Laboratory of Global Healthcare, School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan.
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36
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Rujas E, Caaveiro JMM, Insausti S, García-Porras M, Tsumoto K, Nieva JL. Peripheral Membrane Interactions Boost the Engagement by an Anti-HIV-1 Broadly Neutralizing Antibody. J Biol Chem 2017; 292:5571-5583. [PMID: 28213514 DOI: 10.1074/jbc.m117.775429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/16/2017] [Indexed: 12/16/2022] Open
Abstract
The 4E10 antibody displays an extreme breadth of HIV-1 neutralization and therefore constitutes a suitable model system for structure-guided vaccine design and immunotherapeutics against AIDS. In this regard, the relevance of autoreactivity with membrane lipids for the biological function of this antibody is still a subject of controversy. To address this dispute, herein we have compared the membrane partitioning ability of the 4E10 antibody and several of its variants, which were mutated at the region of the paratope surface in contact with the membrane interface. We first employed a physical separation approach (vesicle flotation) and subsequently carried out quantitative fluorescence measurements in an intact system (spectroscopic titration), using 4E10 Fab labeled with a polarity-sensitive fluorescent probe. Moreover, recognition of epitope peptide in membrane was demonstrated by photo-cross-linking assays using a Fab that incorporated the genetically encoded unnatural amino acid p-benzoylphenylalanine. The experimental data ruled out that the proposed stereospecific recognition of viral lipids was necessary for the function of the antibody. In contrast, our data suggest that nonspecific electrostatic interactions between basic residues of 4E10 and acidic phospholipids in the membranes contribute to the observed biological function. Moreover, the energetics of membrane partitioning indicated that 4E10 behaves as a peripheral membrane protein, tightening the binding to the ligand epitope inserted in the viral membrane. The implications of these findings for the natural production and biological function of this antibody are discussed.
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Affiliation(s)
- Edurne Rujas
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and.,the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, 113-8656, Japan
| | - José M M Caaveiro
- the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, 113-8656, Japan
| | - Sara Insausti
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and
| | - Miguel García-Porras
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and
| | - Kouhei Tsumoto
- the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, 113-8656, Japan
| | - José L Nieva
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and
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