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Cabrera-Rodríguez R, Pérez-Yanes S, Lorenzo-Sánchez I, Trujillo-González R, Estévez-Herrera J, García-Luis J, Valenzuela-Fernández A. HIV Infection: Shaping the Complex, Dynamic, and Interconnected Network of the Cytoskeleton. Int J Mol Sci 2023; 24:13104. [PMID: 37685911 PMCID: PMC10487602 DOI: 10.3390/ijms241713104] [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: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.
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Affiliation(s)
- Romina Cabrera-Rodríguez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Silvia Pérez-Yanes
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Iria Lorenzo-Sánchez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Rodrigo Trujillo-González
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
- Analysis Department, Faculty of Mathematics, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
| | - Judith Estévez-Herrera
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Jonay García-Luis
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
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Alvarez-Rivera E, Rodríguez-Valentín M, Boukli NM. The Antiviral Compound PSP Inhibits HIV-1 Entry via PKR-Dependent Activation in Monocytic Cells. Viruses 2023; 15:804. [PMID: 36992512 PMCID: PMC10051440 DOI: 10.3390/v15030804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023] Open
Abstract
Actin depolymerization factor (ADF) cofilin-1 is a key cytoskeleton component that serves to lessen cortical actin. HIV-1 manipulates cofilin-1 regulation as a pre- and post-entry requisite. Disruption of ADF signaling is associated with denial of entry. The unfolded protein response (UPR) marker Inositol-Requiring Enzyme-1α (IRE1α) and interferon-induced protein (IFN-IP) double-stranded RNA- activated protein kinase (PKR) are reported to overlap with actin components. In our published findings, Coriolus versicolor bioactive extract polysaccharide peptide (PSP) has demonstrated anti-HIV replicative properties in THP1 monocytic cells. However, its involvement towards viral infectivity has not been elucidated before. In the present study, we examined the roles of PKR and IRE1α in cofilin-1 phosphorylation and its HIV-1 restrictive roles in THP1. HIV-1 p24 antigen was measured through infected supernatant to determine PSP's restrictive potential. Quantitative proteomics was performed to analyze cytoskeletal and UPR regulators. PKR, IRE1α, and cofilin-1 biomarkers were measured through immunoblots. Validation of key proteome markers was done through RT-qPCR. PKR/IRE1α inhibitors were used to validate viral entry and cofilin-1 phosphorylation through Western blots. Our findings show that PSP treatment before infection leads to an overall lower infectivity. Additionally, PKR and IRE1α show to be key regulators in cofilin-1 phosphorylation and viral restriction.
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Affiliation(s)
- Eduardo Alvarez-Rivera
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, Bayamόn, PR 00960, USA
| | | | - Nawal M. Boukli
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, Bayamόn, PR 00960, USA
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3
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Negi G, Sharma A, Dey M, Dhanawat G, Parveen N. Membrane attachment and fusion of HIV-1, influenza A, and SARS-CoV-2: resolving the mechanisms with biophysical methods. Biophys Rev 2022; 14:1109-1140. [PMID: 36249860 PMCID: PMC9552142 DOI: 10.1007/s12551-022-00999-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/16/2022] [Indexed: 10/31/2022] Open
Abstract
Attachment to and fusion with cell membranes are two major steps in the replication cycle of many human viruses. We focus on these steps for three enveloped viruses, i.e., HIV-1, IAVs, and SARS-CoV-2. Viral spike proteins drive the membrane attachment and fusion of these viruses. Dynamic interactions between the spike proteins and membrane receptors trigger their specific attachment to the plasma membrane of host cells. A single virion on cell membranes can engage in binding with multiple receptors of the same or different types. Such dynamic and multivalent binding of these viruses result in an optimal attachment strength which in turn leads to their cellular entry and membrane fusion. The latter process is driven by conformational changes of the spike proteins which are also class I fusion proteins, providing the energetics of membrane tethering, bending, and fusion. These viruses exploit cellular and membrane factors in regulating the conformation changes and membrane processes. Herein, we describe the major structural and functional features of spike proteins of the enveloped viruses including highlights on their structural dynamics. The review delves into some of the case studies in the literature discussing the findings on multivalent binding, membrane hemifusion, and fusion of these viruses. The focus is on applications of biophysical tools with an emphasis on single-particle methods for evaluating mechanisms of these processes at the molecular and cellular levels.
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Affiliation(s)
- Geetanjali Negi
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
| | - Anurag Sharma
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
| | - Manorama Dey
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
| | - Garvita Dhanawat
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
| | - Nagma Parveen
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
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4
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Klug YA, Schwarzer R, Ravula T, Rotem E, Ramamoorthy A, Shai Y. Structural and Mechanistic Evidence for Calcium Interacting Sites in the HIV Transmembrane Protein gp41 Involved in Membrane Fusion. Biochemistry 2022; 61:1915-1922. [PMID: 35994087 PMCID: PMC9454089 DOI: 10.1021/acs.biochem.2c00372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/05/2022] [Indexed: 11/29/2022]
Abstract
The HIV envelope protein gp160 comprises two subunits, gp120 and gp41, responsible for receptor binding and membrane fusion during viral entry, respectively. In the course of the membrane fusion process, gp41 undergoes a conformational change, leading to the formation of a six-helix bundle (SHB), which ultimately drives membrane fusion. The gp41 C-terminal and N-terminal heptad repeats (CHR and NHR) interact with one another to form the SHB, and this step can be targeted by peptide inhibitors, which are used in the clinic to mitigate HIV infection. Here, we discover the calcium interaction motifs (CIMs) in the gp41 CHR and NHR regions via NMR spectroscopy. We find that the assembly of the CHR-NHR SHB is facilitated in Ca2+-containing media and impaired in CIM mutants. Of note, the clinically approved, gp41-derived fusion inhibitor T20, which does not contain the CIM motif, exhibits reduced inhibitory efficiency when challenged with calcium. This finding could have important implications for the development of better fusion inhibitors for HIV.
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Affiliation(s)
- Yoel A. Klug
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
| | - Roland Schwarzer
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
- Institute
for Translational HIV Research, University Hospital Essen, University of Duisburg-Essen, Essen 45147, Germany
| | - Thirupathi Ravula
- Biophysics
Program, Department of Chemistry, Macromolecular Science and Engineering,
Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Etai Rotem
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
| | - Ayyalusamy Ramamoorthy
- Biophysics
Program, Department of Chemistry, Macromolecular Science and Engineering,
Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Yechiel Shai
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
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5
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Cisneros WJ, Cornish D, Hultquist JF. Application of CRISPR-Cas9 Gene Editing for HIV Host Factor Discovery and Validation. Pathogens 2022; 11:pathogens11080891. [PMID: 36015010 PMCID: PMC9415735 DOI: 10.3390/pathogens11080891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/30/2022] [Accepted: 08/03/2022] [Indexed: 12/04/2022] Open
Abstract
Human Immunodeficiency Virus (HIV) interacts with a wide array of host factors at each stage of its lifecycle to facilitate replication and circumvent the immune response. Identification and characterization of these host factors is critical for elucidating the mechanism of viral replication and for developing next-generation HIV-1 therapeutic and curative strategies. Recent advances in CRISPR-Cas9-based genome engineering approaches have provided researchers with an assortment of new, valuable tools for host factor discovery and interrogation. Genome-wide screening in a variety of in vitro cell models has helped define the critical host factors that play a role in various cellular and biological contexts. Targeted manipulation of specific host factors by CRISPR-Cas9-mediated gene knock-out, overexpression, and/or directed repair have furthermore allowed for target validation in primary cell models and mechanistic inquiry through hypothesis-based testing. In this review, we summarize several CRISPR-based screening strategies for the identification of HIV-1 host factors and highlight how CRISPR-Cas9 approaches have been used to elucidate the molecular mechanisms of viral replication and host response. Finally, we examine promising new technologies in the CRISPR field and how these may be applied to address critical questions in HIV-1 biology going forward.
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Affiliation(s)
- William J. Cisneros
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Center for Pathogen Genomics and Microbial Evolution, Northwestern University Havey Institute for Global Health, Chicago, IL 60611, USA
| | - Daphne Cornish
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Center for Pathogen Genomics and Microbial Evolution, Northwestern University Havey Institute for Global Health, Chicago, IL 60611, USA
| | - Judd F. Hultquist
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Center for Pathogen Genomics and Microbial Evolution, Northwestern University Havey Institute for Global Health, Chicago, IL 60611, USA
- Correspondence:
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Tu JJ, Maksimova V, Ratner L, Panfil AR. The Past, Present, and Future of a Human T-Cell Leukemia Virus Type 1 Vaccine. Front Microbiol 2022; 13:897346. [PMID: 35602078 PMCID: PMC9114509 DOI: 10.3389/fmicb.2022.897346] [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: 03/16/2022] [Accepted: 04/13/2022] [Indexed: 11/13/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic human retrovirus which causes a lifelong infection. An estimated 5-10 million persons are infected with HTLV-1 worldwide - a number which is likely higher due to lack of reliable epidemiological data. Most infected individuals remain asymptomatic; however, a portion of HTLV-1-positive individuals will develop an aggressive CD4+ T-cell malignancy called adult T-cell leukemia/lymphoma (ATL), or a progressive neurodegenerative disease known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Few treatment options exist for HAM/TSP outside of palliative care and ATL carries an especially poor prognosis given the heterogeneity of the disease and lack of effective long-term treatments. In addition, the risk of HTLV-1 disease development increases substantially if the virus is acquired early in life. Currently, there is no realistic cure for HTLV-1 infection nor any reliable measure to prevent HTLV-1-mediated disease development. The severity of HTLV-1-associated diseases (ATL, HAM/TSP) and limited treatment options highlights the need for development of a preventative vaccine or new therapeutic interventions. This review will highlight past HTLV-1 vaccine development efforts, the current molecular tools and animal models which might be useful in vaccine development, and the future possibilities of an effective HTLV-1 vaccine.
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Affiliation(s)
- Joshua J. Tu
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Victoria Maksimova
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
- Comprehensive Cancer Center, The Ohio State University, Columbus, OH, United States
| | - Lee Ratner
- Division of Molecular Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Amanda R. Panfil
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
- Comprehensive Cancer Center, The Ohio State University, Columbus, OH, United States
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7
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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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8
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Tharayil A, Rajakumari R, Kumar A, Choudhary MD, Palit P, Thomas S. New insights into application of nanoparticles in the diagnosis and screening of novel coronavirus (SARS-CoV-2). EMERGENT MATERIALS 2021; 4:101-117. [PMID: 33817553 PMCID: PMC8010296 DOI: 10.1007/s42247-021-00182-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/03/2021] [Indexed: 05/15/2023]
Abstract
Novel coronavirus disease 2019 (COVID-19) is by far the worst pandemic disease in the current millennium. The first human-to-human transmission was observed in December 2019 in China and is caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has infected millions of people within months across the globe. SARS-CoV-2 is a spike protein enveloped virus with particle-like characteristics and a diameter of 60-140 nm. Real-time PCR, reverse transcriptase PCR, isothermal PCR, immunological-based detection technique and nano-based diagnostic system have been explained for the identification and differentiation of different types of virus including SARS-COV-2. Synthetic nanoparticles can closely mimic the virus and interact strongly with its virulent proteins due to their morphological similarities. Some of the antiviral nanomaterials are also discussed, for example zinc oxide nanoparticle is an antiviral agent with a tetrapod morphology that mimics the cell surface by interacting with the viral capsid. It suppressed the viral proteins upon UV radiation due to reaction caused by photocatalysis. Hence, nanoparticle-based strategies for tackling viruses have immense potential. The second part of the review points to the latest in vitro and in vivo procedures for screening viral particles and the usage of nanoparticles in diagnostic and therapeutics. This would be beneficial for early detection and assists for the safe and effective therapeutic management of COVID-19.
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Affiliation(s)
- Abhimanyu Tharayil
- School of Energy Materials, Mahatma Gandhi University, Kerala, 686560 India
| | - R. Rajakumari
- International and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kerala, 686560 India
| | - Amresh Kumar
- Department of Life Sciences and Bioinformatics, Assam University, Silchar, India
| | | | - Parth Palit
- Department of Pharmaceutical Sciences, Assam University, Silchar, India
| | - Sabu Thomas
- School of Energy Materials, Mahatma Gandhi University, Kerala, 686560 India
- School of Chemical Sciences, Mahatma Gandhi University, Kerala, 686560 India
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Yamamoto M, Ichinohe T, Watanabe A, Kobayashi A, Zhang R, Song J, Kawaguchi Y, Matsuda Z, Inoue JI. The Antimalarial Compound Atovaquone Inhibits Zika and Dengue Virus Infection by Blocking E Protein-Mediated Membrane Fusion. Viruses 2020; 12:v12121475. [PMID: 33371476 PMCID: PMC7767512 DOI: 10.3390/v12121475] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/16/2020] [Accepted: 12/19/2020] [Indexed: 12/12/2022] Open
Abstract
Flaviviruses bear class II fusion proteins as their envelope (E) proteins. Here, we describe the development of an in vitro quantitative mosquito-cell-based membrane-fusion assay for the E protein using dual split proteins (DSPs). The assay does not involve the use of live viruses and allows the analysis of a membrane-fusion step independent of other events in the viral lifecycle, such as endocytosis. The progress of membrane fusion can be monitored continuously by measuring the activities of Renilla luciferase derived from the reassociation of DSPs during cell fusion. We optimized the assay to screen an FDA-approved drug library for a potential membrane fusion inhibitor using the E protein of Zika virus. Screening results identified atovaquone, which was previously described as an antimalarial agent. Atovaquone potently blocked the in vitro Zika virus infection of mammalian cells with an IC90 of 2.1 µM. Furthermore, four distinct serotypes of dengue virus were also inhibited by atovaquone with IC90 values of 1.6–2.5 µM, which is a range below the average blood concentration of atovaquone after its oral administration in humans. These findings make atovaquone a likely candidate drug to treat illnesses caused by Zika as well as dengue viruses. Additionally, the DSP assay is useful to study the mechanism of membrane fusion in Flaviviruses.
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Affiliation(s)
- Mizuki Yamamoto
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan; (M.Y.); (A.W.); (A.K.); (Y.K.)
- Division of Cellular and Molecular Biology, Department of Cancer Biology, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takeshi Ichinohe
- Division of Viral Infection, Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan;
| | - Aya Watanabe
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan; (M.Y.); (A.W.); (A.K.); (Y.K.)
- Division of Cellular and Molecular Biology, Department of Cancer Biology, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Ayako Kobayashi
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan; (M.Y.); (A.W.); (A.K.); (Y.K.)
| | - Rui Zhang
- Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100864, China;
| | - Jiping Song
- China-Japan Joint Laboratory of Molecular Immunology & Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100864, China;
| | - Yasushi Kawaguchi
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan; (M.Y.); (A.W.); (A.K.); (Y.K.)
- Division of Molecular Virology, Department of Microbiology and Immunology, Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Zene Matsuda
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan; (M.Y.); (A.W.); (A.K.); (Y.K.)
- Department of Microbiology and Infection, Kochi Medical School, Kochi University, Kochi 780-8072, Japan
- Correspondence: (Z.M.); (J.-i.I.); Tel.: +81-3-6409-2204 (Z.M.); +81-3-6409-2476 (J.-i.I.)
| | - Jun-ichiro Inoue
- Research Center for Asian Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan; (M.Y.); (A.W.); (A.K.); (Y.K.)
- Division of Cellular and Molecular Biology, Department of Cancer Biology, The Institute of Medical Science, The University of Tokyo, Tokyo 113-0033, Japan
- Senior Professor Office, The University of Tokyo, Tokyo 113-0033, Japan
- Correspondence: (Z.M.); (J.-i.I.); Tel.: +81-3-6409-2204 (Z.M.); +81-3-6409-2476 (J.-i.I.)
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10
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The role of fusion peptides in depth-dependent membrane organization and dynamics in promoting membrane fusion. Chem Phys Lipids 2020; 234:105025. [PMID: 33301753 DOI: 10.1016/j.chemphyslip.2020.105025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/16/2020] [Accepted: 12/03/2020] [Indexed: 11/24/2022]
Abstract
Membrane fusion is an important event in the life of eukaryotes; occurs in several processes such as endocytosis, exocytosis, cellular trafficking, compartmentalization, import of nutrients and export of waste, vesiculation, inter cellular communication, and fertilization. The enveloped viruses as well utilize fusion between the viral envelope and host cell membrane for infection. The stretch of 20-25 amino acids located at the N-terminus of the fusion protein, known as fusion peptide, plays a decisive role in the fusion process. The stalk model of membrane fusion postulated a common route of bilayer transformation for stalk, transmembrane contact, and pore formation; and fusion peptide is believed to facilitate bilayer transformation to promote membrane fusion. The peptide-induced change in depth-dependent organization and dynamics could provide important information in understanding the role of fusion peptide in membrane fusion. In this review, we have discussed about three depth-dependent properties of the membrane such as rigidity, polarity and heterogeneity, and the impact of fusion peptide on these three membrane properties.
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Dang LVP, Pham HV, Dinh TT, Vu PT, Nguyen LV, Le HT, Larsson M, Olson L. Molecular genotypes of gag sequences in HIV-1 infected children treated with antiretroviral therapy in Vietnam. Ther Adv Infect Dis 2020; 7:2049936120958536. [PMID: 32994994 PMCID: PMC7502858 DOI: 10.1177/2049936120958536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 08/18/2020] [Indexed: 11/16/2022] Open
Abstract
Background: Gag protein of human immunodeficiency virus (HIV) has been reported to play a crucial role in establishing infection, viral replication, and disease progression; thus, gag might be related to treatment response. The objective of this study was to investigate molecular genotypes of the gag gene, particularly the important functional binding domains in relation to treatment outcomes. Methods: HIV-infected children enrolled and treated at Vietnam National Children’s Hospital were recruited in the study. A total of 25 gag sequences were generated and used to construct phylogenetic trees and aligned with a reference sequence comparing 17 functional domains. Results: We found that all patients in a treatment failure (TF) group belonged to one cluster of the phylogenetic tree. In addition, the rate of mutations was significantly higher in TF compared with a treatment success (TS) group, specifically the PIP2 recognition motif, and the nucleocapsid basic and zinc motif 2 domains [median and (interquartile range (IQR): 12.5 (6.25–12.5) versus 50 (25–50), p < 0.01; 0 (0–0) versus 0 (0–21.43), p = 0.03 and 0 (0–7.14) versus 7.14 (7.14–7.14), p = 0.04, respectively]. When analyzing gag sequences at different time points in seven patients, we did not observe a consistent mutation pattern related to treatment response. Conclusion: Gag mutations in certain domains might be associated with increased viral load; therefore, studying the molecular genotype of the gag gene might be beneficial in monitoring treatment response in HIV-infected children.
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Affiliation(s)
- Linh Vu Phuong Dang
- Laboratory Centre, Hanoi University of Public Health, 1 Duc Thang, North Tu Liem, Hanoi, Vietnam
| | | | | | - Phuong Thi Vu
- Dinh Tien Hoang Institute of Medicine, Hanoi, Vietnam
| | | | - Hai Thanh Le
- Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Mattias Larsson
- Training and Research Academic Collaboration (TRAC), Sweden, Vietnam
| | - Linus Olson
- Training and Research Academic Collaboration (TRAC), Sweden, Vietnam
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12
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Featherstone A, Aiken C. SERINC5 Inhibits HIV-1 Infectivity by Altering the Conformation of gp120 on HIV-1 Particles. J Virol 2020; 94:e00594-20. [PMID: 32796070 PMCID: PMC7527050 DOI: 10.1128/jvi.00594-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/03/2020] [Indexed: 01/25/2023] Open
Abstract
SERINC5 is a 10-transmembrane-domain cellular protein that is incorporated into budding HIV-1 particles and reduces HIV-1 infectivity by inhibiting virus-cell fusion. HIV-1 susceptibility to SERINC5 is determined by sequences in the viral Env glycoprotein gp120, and the antiviral effect of SERINC5 is counteracted by the viral accessory protein Nef. While the precise mechanism by which SERINC5 inhibits HIV-1 infectivity is unclear, previous studies have suggested that SERINC5 affects Env conformation. To define the effects of SERINC5 on Env conformation, we quantified the binding of HIV-1 particles to immobilized Env-specific monoclonal antibodies. We observed that SERINC5 reduced the binding of HIV-1 particles bearing a SERINC5-susceptible Env to antibodies that recognize the V3 loop, a soluble CD4 (sCD4)-induced epitope, and an N-linked glycan. In contrast, SERINC5 did not alter the capture of HIV-1 particles bearing the SERINC5-resistant Env protein. Moreover, the effect of SERINC5 on antibody-dependent virus capture was abrogated by Nef expression. Our results indicate that SERINC5 inhibits HIV-1 infectivity by altering the conformation of gp120 on virions and/or physical masking of specific HIV-1 Env epitopes.IMPORTANCE SERINC5 is a host cell protein that inhibits the infectivity of HIV-1 by a novel and poorly understood mechanism. Here, we provide evidence that the SERINC5 protein alters the conformation of the HIV-1 Env proteins and that this action is correlated with SERINC5's ability to inhibit HIV-1 infectivity. Defining the specific effects of SERINC5 on the HIV-1 glycoprotein conformation may be useful for designing new antiviral strategies targeting Env.
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Affiliation(s)
- Austin Featherstone
- Vanderbilt University Medical Center, Department of Pathology, Microbiology and Immunology, Nashville, Tennessee, USA
| | - Christopher Aiken
- Vanderbilt University Medical Center, Department of Pathology, Microbiology and Immunology, Nashville, Tennessee, USA
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13
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Pattnaik GP, Chakraborty H. Entry Inhibitors: Efficient Means to Block Viral Infection. J Membr Biol 2020; 253:425-444. [PMID: 32862236 PMCID: PMC7456447 DOI: 10.1007/s00232-020-00136-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/14/2020] [Indexed: 12/12/2022]
Abstract
The emerging and re-emerging viral infections are constant threats to human health and wellbeing. Several strategies have been explored to develop vaccines against these viral diseases. The main effort in the journey of development of vaccines is to neutralize the fusion protein using antibodies. However, significant efforts have been made in discovering peptides and small molecules that inhibit the fusion between virus and host cell, thereby inhibiting the entry of viruses. This class of inhibitors is called entry inhibitors, and they are extremely efficient in reducing viral infection as the entry of the virus is considered as the first step of infection. Nevertheless, these inhibitors are highly selective for a particular virus as antibody-based vaccines. The recent COVID-19 pandemic lets us ponder to shift our attention towards broad-spectrum antiviral agents from the so-called ‘one bug-one drug’ approach. This review discusses peptide and small molecule-based entry inhibitors against class I, II, and III viruses and sheds light on broad-spectrum antiviral agents.
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Affiliation(s)
| | - Hirak Chakraborty
- School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768 019, India. .,Centre of Excellence in Natural Products and Therapeutics, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768 019, India.
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14
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Su X, Wang Q, Wen Y, Jiang S, Lu L. Protein- and Peptide-Based Virus Inactivators: Inactivating Viruses Before Their Entry Into Cells. Front Microbiol 2020; 11:1063. [PMID: 32523582 PMCID: PMC7261908 DOI: 10.3389/fmicb.2020.01063] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/29/2020] [Indexed: 12/20/2022] Open
Abstract
Infectious diseases caused by human immunodeficiency virus (HIV) and other highly pathogenic enveloped viruses, have threatened the global public health. Most antiviral drugs act as passive defenders to inhibit viral replication inside the cell, while a few of them function as gate keepers to combat viruses outside the cell, including fusion inhibitors, e.g., enfuvirtide, and receptor antagonists, e.g., maraviroc, as well as virus inactivators (including attachment inhibitors). Different from fusion inhibitors and receptor antagonists that must act in the presence of target cells, virus inactivators can actively inactivate cell-free virions in the blood, through interaction with one or more sites in the envelope glycoproteins (Envs) on virions. Notably, a number of protein- and peptide-based virus inactivators (PPVIs) under development are expected to have a better utilization rate than the current antiviral drugs and be safer for in vivo human application than the chemical-based virus inactivators. Here we have highlighted recent progress in developing PPVIs against several important enveloped viruses, including HIV, influenza virus, Zika virus (ZIKV), dengue virus (DENV), and herpes simplex virus (HSV), and the potential use of PPVIs for urgent treatment of infection by newly emerging or re-emerging viruses.
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Affiliation(s)
- Xiaojie Su
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Qian Wang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yumei Wen
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China.,Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
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15
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Qiu J, Liang T, Wu J, Yu F, He X, Tian Y, Xie L, Jiang S, Liu S, Li L. N-Substituted Pyrrole Derivative 12m Inhibits HIV-1 Entry by Targeting Gp41 of HIV-1 Envelope Glycoprotein. Front Pharmacol 2019; 10:859. [PMID: 31427969 PMCID: PMC6688628 DOI: 10.3389/fphar.2019.00859] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 07/05/2019] [Indexed: 11/13/2022] Open
Abstract
The combination of three or more antiviral agents that act on different targets is known as highly active antiretroviral therapy (HAART), which is widely used to control HIV infection. However, because drug resistance and adverse effects occur after long-term administration, an increasing number of HIV/AIDS patients do not tolerate HAART. It is necessary to continue developing novel anti-HIV drugs, particularly HIV entry/fusion inhibitors. Our group previously identified a small-molecule compound, NB-64, with weak anti-HIV activity. Here, we found that N-substituted pyrrole derivative 12m (NSPD-12m), which was derived from NB-64, had strong anti-HIV-1 activity, and NSPD-12m-treated cells showed good viability. The mechanism of action of NSPD-12m might be targeting the gp41 transmembrane subunit of the HIV envelope glycoprotein, thus inhibiting HIV entry. Site-directed mutagenesis confirmed that a positively charged lysine residue (K574) located in the gp41 pocket region is pivotal for the binding of NSPD-12m to gp41. These findings suggest that NSPD-12m can serve as a lead compound to develop novel virus entry inhibitors.
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Affiliation(s)
- Jiayin Qiu
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.,School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China.,Department of Pharmacy, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Taizhen Liang
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Junyan Wu
- Department of Pharmacy, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Fei Yu
- College of Life Sciences, Agricultural University of Hebei, Baoding, China.,Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaoyang He
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yuanxin Tian
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Lan Xie
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College, Fudan University, Shanghai, China
| | - Shuwen Liu
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Lin Li
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
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Gorai B, Das S, Maiti PK. Prediction and validation of HIV-1 gp41 ecto-transmembrane domain post-fusion trimeric structure using molecular modeling. J Biomol Struct Dyn 2019; 38:2592-2603. [DOI: 10.1080/07391102.2019.1635916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Biswajit Gorai
- Department of Physics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Satyabrata Das
- Department of Physics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Prabal K. Maiti
- Department of Physics, Indian Institute of Science, Bangalore, Karnataka, India
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17
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Broadly resistant HIV-1 against CD4-binding site neutralizing antibodies. PLoS Pathog 2019; 15:e1007819. [PMID: 31194843 PMCID: PMC6592578 DOI: 10.1371/journal.ppat.1007819] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 06/25/2019] [Accepted: 05/07/2019] [Indexed: 01/15/2023] Open
Abstract
Recently identified broadly neutralizing antibodies (bnAbs) show great potential for clinical interventions against HIV-1 infection. However, resistant strains may impose substantial challenges. Here, we report on the identification and characterization of a panel of HIV-1 strains with broad and potent resistance against a large number of bnAbs, particularly those targeting the CD4-binding site (CD4bs). Site-directed mutagenesis revealed that several key epitope mutations facilitate resistance and are located in the inner domain, loop D, and β23/loop V5/β24 of HIV-1 gp120. The resistance is largely correlated with binding affinity of antibodies to the envelope trimers expressed on the cell surface. Our results therefore demonstrate the existence of broadly resistant HIV-1 strains against CD4bs neutralizing antibodies. Treatment strategies based on the CD4bs bnAbs must overcome such resistance to achieve optimal clinical outcomes. Recently identified broadly neutralizing antibodies (bnAbs) show great potential for clinical interventions against HIV-1 infection. Among the bnAbs isolated to date, those targeting the CD4bs are the most abundant and thoroughly studied as they disrupt the crucial step of viral interaction with the cellular receptor molecule CD4. Despite the superior potency and breadth of these CD4bs bnAbs, each fails to neutralize a small but significant portion of pseudotyped virus panels. Here, we report on the identification and characterization of a panel of HIV-1 strains with broad and potent resistance against a large number of bnAbs, particularly those targeting the CD4bs. Resistance is largely attributed to mutated residues within the epitopes or steric hindrance imposed by the bulky side-chain or glycan shield of the mutated residues, and is largely correlated with reduced binding avidity of the antibody to the quaternary trimeric envelope protein expressed on the surface of the transfected cells. Treatment strategies based on the CD4bs bnAbs therefore must overcome such resistance to achieve optimal clinical outcomes.
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18
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CD4-Dependent Modulation of HIV-1 Entry by LY6E. J Virol 2019; 93:JVI.01866-18. [PMID: 30674630 DOI: 10.1128/jvi.01866-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/16/2019] [Indexed: 01/06/2023] Open
Abstract
Lymphocyte antigen 6E (LY6E) is a GPI-anchored, interferon-inducible protein that has been shown to modulate viral infection in a cell type-dependent manner. Our recent work showed that LY6E promotes HIV-1 infection in some high-CD4-expressing cells, including human peripheral blood mononuclear cells (PBMCs) and the SupT1 cell line. In this work, we provide evidence that LY6E inhibits HIV-1 entry and spread in low-CD4-expressing Jurkat cells and human monocyte-derived macrophages (MDMs) through downregulation of the viral receptor CD4. We found that knockdown of LY6E in Jurkat cells and MDMs increases HIV-1 infection, yet overexpression of LY6E in Jurkat cells inhibits HIV-1 entry and replication. LY6E was found to be colocalized with CD4 on the plasma membrane of Jurkat cells and MDMs and enhances CD4 internalization. We artificially manipulated the CD4 level in Jurkat and SupT1 cells and found that overexpression of CD4 in Jurkat cells overcomes the inhibitory effect of LY6E; conversely, blocking the function of CD4 in SupT1 with a neutralizing antibody eliminates the enhancement of LY6E on HIV-1 entry. The CD4-dependent inhibitory phenotype of LY6E in low-CD4-expressing human MDMs can be recapitulated for a panel of transmitted founder viruses and laboratory-adapted HIV-1 strains. Given that HIV-1 can target low-CD4-expressing cells during acute infection yet replicates efficiently in high-CD4-expressing T cells at the late stage of disease, our observation that LY6E differentially modulates HIV-1 replication in a CD4-dependent manner has implications for understanding the complex roles of interferon (IFN)-induced proteins in AIDS pathogenesis.IMPORTANCE The role of IFN-induced genes (ISGs) in viral infection remains incompletely understood. While most ISGs are antiviral, some ISGs have been shown to promote viral infection, including HIV-1 infection. We previously showed that IFN-inducible LY6E protein promotes HIV-1 infection in human PMBCs and high-CD4-expressing SupT1 cells. Here we found that LY6E inhibits HIV-1 entry and replication in low-CD4-expressing MDMs and Jurkat cells. Mechanistically, we demonstrated that LY6E downregulates the cell surface receptor CD4, thus impairing the virus binding to target cells. This is in contrast to the situation of high-CD4-expressing cells, where LY6E predominantly promotes viral membrane fusion. The opposing role of IFN-inducible LY6E in modulating HIV-1 infection highlights the complex roles of ISGs in viral infection and viral pathogenesis.
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19
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Yamamoto M, Du Q, Song J, Wang H, Watanabe A, Tanaka Y, Kawaguchi Y, Inoue JI, Matsuda Z. Cell-cell and virus-cell fusion assay-based analyses of alanine insertion mutants in the distal α9 portion of the JRFL gp41 subunit from HIV-1. J Biol Chem 2019; 294:5677-5687. [PMID: 30737278 DOI: 10.1074/jbc.ra118.004579] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 02/04/2019] [Indexed: 12/28/2022] Open
Abstract
Membrane fusion is the first essential step in HIV-1 replication. The gp41 subunit of HIV-1 envelope protein (Env), a class I fusion protein, achieves membrane fusion by forming a structure called a six-helix bundle composed of N- and C-terminal heptad repeats. We have recently shown that the distal portion of the α9 helix in the C-terminal heptad repeat of X4-tropic HXB2 Env plays a critical role in the late-stage membrane fusion and viral infection. Here, we used R5-tropic JRFL Env and constructed six alanine insertion mutants, 641+A to 646+A, in the further distal portion of α9 where several glutamine residues are conserved (the number corresponds to the position of the inserted alanine in JRFL Env). 644+A showed the most severe defect in syncytia formation. Decreased fusion pore formation activity, revealed by a dual split protein assay, was observed in all mutants except 641+A. Sequence analysis and substitution of inserted 644A with Gln revealed that the glutamine residue at position 644 that forms complex hydrogen-bond networks with other polar residues on the surface of the six-helix bundle is critical for cell-cell fusion. We also developed a split NanoLuc® (Nluc) reporter-based assay specific to the virus-cell membrane fusion step to analyze several of the mutants. Interestingly syncytia-competent mutants failed to display Nluc activities. In addition to defective fusion activity, a reduction of Env incorporation into virions may further contribute to differences in cell-cell and virus-cell fusions.
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Affiliation(s)
- Mizuki Yamamoto
- From the Research Center for Asian Infectious Diseases.,the Division of Cellular and Molecular Biology, and
| | - Qingling Du
- the Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100864, 100101 China, and
| | - Jiping Song
- the Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100864, 100101 China, and
| | - Hongyun Wang
- the Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100864, 100101 China, and
| | - Aya Watanabe
- From the Research Center for Asian Infectious Diseases.,the Division of Cellular and Molecular Biology, and
| | - Yuetsu Tanaka
- the Department of Immunology, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan
| | - Yasushi Kawaguchi
- From the Research Center for Asian Infectious Diseases.,the Division of Molecular Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Jun-Ichiro Inoue
- From the Research Center for Asian Infectious Diseases, .,the Division of Cellular and Molecular Biology, and
| | - Zene Matsuda
- From the Research Center for Asian Infectious Diseases, .,the Laboratory of Structural Virology and Immunology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100864, 100101 China, and
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de Sousa-Pereira P, Abrantes J, Bauernfried S, Pierini V, Esteves PJ, Keppler OT, Pizzato M, Hornung V, Fackler OT, Baldauf HM. The antiviral activity of rodent and lagomorph SERINC3 and SERINC5 is counteracted by known viral antagonists. J Gen Virol 2018; 100:278-288. [PMID: 30566072 DOI: 10.1099/jgv.0.001201] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A first step towards the development of a human immunodeficiency virus (HIV) animal model has been the identification and surmounting of species-specific barriers encountered by HIV along its replication cycle in cells from small animals. Serine incorporator proteins 3 (SERINC3) and 5 (SERINC5) were recently identified as restriction factors that reduce HIV-1 infectivity. Here, we compared the antiviral activity of SERINC3 and SERINC5 among mice, rats and rabbits, and their susceptibility to viral counteraction to their human counterparts. In the absence of viral antagonists, rodent and lagomorph SERINC3 and SERINC5 displayed anti-HIV activity in a similar range to human controls. Vesicular stomatitis virus G protein (VSV-G) pseudotyped virions were considerably less sensitive to restriction by all SERINC3/5 orthologs. Interestingly, HIV-1 Nef, murine leukemia virus (MLV) GlycoGag and equine infectious anemia virus (EIAV) S2 counteracted the antiviral activity of all SERINC3/5 orthologs with similar efficiency. Our results demonstrate that the antiviral activity of SERINC3/5 proteins is conserved in rodents and rabbits, and can be overcome by all three previously reported viral antagonists.
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Affiliation(s)
- Patrícia de Sousa-Pereira
- 3Institute of Medical Virology, University Hospital Frankfurt, Frankfurt, Germany.,1CIBIO/InBIO- Research Network in Biodiversity and Evolutionary Biology, Campus de Vairão, University of Porto, Vairão, Portugal.,5Institute of Virology, Technische Universität München/Helmholtz Zentrum, Munich, Germany.,4Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany.,2Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Joana Abrantes
- 1CIBIO/InBIO- Research Network in Biodiversity and Evolutionary Biology, Campus de Vairão, University of Porto, Vairão, Portugal
| | - Stefan Bauernfried
- 6Gene Center and Department of Biochemistry, LMU München, Munich, Germany
| | - Virginia Pierini
- 7Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Pedro José Esteves
- 1CIBIO/InBIO- Research Network in Biodiversity and Evolutionary Biology, Campus de Vairão, University of Porto, Vairão, Portugal.,2Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal.,8CITS - Centro de Investigação em Tecnologias de Saúde, CESPU, Gandra, Portugal
| | - Oliver T Keppler
- 3Institute of Medical Virology, University Hospital Frankfurt, Frankfurt, Germany.,4Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany.,5Institute of Virology, Technische Universität München/Helmholtz Zentrum, Munich, Germany
| | - Massimo Pizzato
- 9University of Trento, Centre for Integrative Biology, Trento, Italy
| | - Veit Hornung
- 6Gene Center and Department of Biochemistry, LMU München, Munich, Germany
| | - Oliver T Fackler
- 7Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Hanna-Mari Baldauf
- 5Institute of Virology, Technische Universität München/Helmholtz Zentrum, Munich, Germany.,3Institute of Medical Virology, University Hospital Frankfurt, Frankfurt, Germany.,4Max von Pettenkofer Institute & Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany
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21
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A Novel gp41-Binding Adnectin with Potent Anti-HIV Activity Is Highly Synergistic when Linked to a CD4-Binding Adnectin. J Virol 2018; 92:JVI.00421-18. [PMID: 29743355 DOI: 10.1128/jvi.00421-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 04/26/2018] [Indexed: 12/27/2022] Open
Abstract
The N17 region of gp41 in HIV-1 is the most conserved region in gp160. mRNA selection technologies were used to identify an adnectin that binds to this region and inhibits gp41-induced membrane fusion. Additional selection conditions were used to optimize the adnectin to greater potency (5.4 ± 2.6 nM) against HIV-1 and improved binding affinity for an N17-containing helical trimer (0.8 ± 0.4 nM). Resistance to this adnectin mapped to a single Glu-to-Arg change within the N17 coding region. The optimized adnectin (6200_A08) exhibited high potency and broad-spectrum activity against 123 envelope proteins and multiple clinical virus isolates, although certain envelope proteins did exhibit reduced susceptibility to 6200_A08 alone. The reduced potency could not be correlated with sequence changes in the target region and was thought to be the result of faster kinetics of fusion mediated by these envelope proteins. Optimized linkage of 6200_A08 with a previously characterized adnectin targeting CD4 produced a highly synergistic molecule, with the potency of the tandem molecule measured at 37 ± 1 pM. In addition, these tandem molecules now exhibited few potency differences against the same panel of envelope proteins with reduced susceptibility to 6200_A08 alone, providing evidence that they did not have intrinsic resistance to 6200_A08 and that coupling 6200_A08 with the anti-CD4 adnectin may provide a higher effective on rate for gp41 target engagement.IMPORTANCE There continue to be significant unmet medical needs for patients with HIV-1 infection. One way to improve adherence and decrease the likelihood of drug-drug interactions in HIV-1-infected patients is through the development of long-acting biologic inhibitors. This study describes the development and properties of an adnectin molecule that targets the most conserved region of the gp41 protein and inhibits HIV-1 with good potency. Moreover, when fused to a similar adnectin targeted to the human CD4 protein, the receptor for HIV-1, significant synergies in potency and efficacy are observed. These inhibitors are part of an effort to develop a larger biologic molecule that functions as a long-acting self-administered regimen for patients with HIV-1 infection.
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22
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Rumlová M, Ruml T. In vitro methods for testing antiviral drugs. Biotechnol Adv 2018; 36:557-576. [PMID: 29292156 PMCID: PMC7127693 DOI: 10.1016/j.biotechadv.2017.12.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/22/2017] [Accepted: 12/27/2017] [Indexed: 12/24/2022]
Abstract
Despite successful vaccination programs and effective treatments for some viral infections, humans are still losing the battle with viruses. Persisting human pandemics, emerging and re-emerging viruses, and evolution of drug-resistant strains impose continuous search for new antiviral drugs. A combination of detailed information about the molecular organization of viruses and progress in molecular biology and computer technologies has enabled rational antivirals design. Initial step in establishing efficacy of new antivirals is based on simple methods assessing inhibition of the intended target. We provide here an overview of biochemical and cell-based assays evaluating the activity of inhibitors of clinically important viruses.
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Affiliation(s)
- Michaela Rumlová
- Department of Biotechnology, University of Chemistry and Technology, Prague 166 28, Czech Republic.
| | - Tomáš Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague 166 28, Czech Republic.
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23
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Abstract
HIV fusion with the cell membrane can be inhibited by blocking coreceptor binding or by preventing fusion-inducing conformational changes in the Env protein. Logically, inhibitors that act by these two mechanisms should act synergistically, but previous studies have reported conflicting results. A new study by Ahn and Root reconciles these discordant reports by demonstrating that synergy emerges when Env engages multiple coreceptors prior to inducing fusion and when high-affinity inhibitory peptides are used, a condition that may not be satisfied in vivo.
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Affiliation(s)
- Gregory B Melikyan
- From the Department of Pediatrics, Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
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24
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Serrano S, Huarte N, Rujas E, Andreu D, Nieva JL, Jiménez MA. Structure-Related Roles for the Conservation of the HIV-1 Fusion Peptide Sequence Revealed by Nuclear Magnetic Resonance. Biochemistry 2017; 56:5503-5511. [PMID: 28930470 DOI: 10.1021/acs.biochem.7b00745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite extensive characterization of the human immunodeficiency virus type 1 (HIV-1) hydrophobic fusion peptide (FP), the structure-function relationships underlying its extraordinary degree of conservation remain poorly understood. Specifically, the fact that the tandem repeat of the FLGFLG tripeptide is absolutely conserved suggests that high hydrophobicity may not suffice to unleash FP function. Here, we have compared the nuclear magnetic resonance (NMR) structures adopted in nonpolar media by two FP surrogates, wtFP-tag and scrFP-tag, which had equal hydrophobicity but contained wild-type and scrambled core sequences LFLGFLG and FGLLGFL, respectively. In addition, these peptides were tagged at their C-termini with an epitope sequence that folded independently, thereby allowing Western blot detection without interfering with FP structure. We observed similar α-helical FP conformations for both specimens dissolved in the low-polarity medium 25% (v/v) 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), but important differences in contact with micelles of the membrane mimetic dodecylphosphocholine (DPC). Thus, whereas wtFP-tag preserved a helix displaying a Gly-rich ridge, the scrambled sequence lost in great part the helical structure upon being solubilized in DPC. Western blot analyses further revealed the capacity of wtFP-tag to assemble trimers in membranes, whereas membrane oligomers were not observed in the case of the scrFP-tag sequence. We conclude that, beyond hydrophobicity, preserving sequence order is an important feature for defining the secondary structures and oligomeric states adopted by the HIV FP in membranes.
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Affiliation(s)
- Soraya Serrano
- Institute of Physical Chemistry "Rocasolano" (IQFR-CSIC) , Serrano 119, E-28006 Madrid, Spain
| | - Nerea Huarte
- Biofisika Institute (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country , P.O. Box 644, 48080 Bilbao, Spain
| | - Edurne Rujas
- Biofisika Institute (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country , P.O. Box 644, 48080 Bilbao, Spain
| | - David Andreu
- Proteomics and Protein Chemistry Unit, Department of Experimental and Health Sciences, Pompeu Fabra University , Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - José L Nieva
- Biofisika Institute (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country , P.O. Box 644, 48080 Bilbao, Spain
| | - María Angeles Jiménez
- Institute of Physical Chemistry "Rocasolano" (IQFR-CSIC) , Serrano 119, E-28006 Madrid, Spain
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25
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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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26
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Discovery and Characterization of a Novel CD4-Binding Adnectin with Potent Anti-HIV Activity. Antimicrob Agents Chemother 2017; 61:AAC.00508-17. [PMID: 28584151 DOI: 10.1128/aac.00508-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/30/2017] [Indexed: 02/08/2023] Open
Abstract
A novel fibronectin-based protein (Adnectin) HIV-1 inhibitor was generated using in vitro selection. This inhibitor binds to human CD4 with a high affinity (3.9 nM) and inhibits viral entry at a step after CD4 engagement and preceding membrane fusion. The progenitor sequence of this novel inhibitor was selected from a library of trillions of Adnectin variants using mRNA display and then further optimized for improved antiviral and physical properties. The final optimized inhibitor exhibited full potency against a panel of 124 envelope (gp160) proteins spanning 11 subtypes, indicating broad-spectrum activity. Resistance profiling studies showed that this inhibitor required 30 passages (151 days) in culture to acquire sufficient resistance to result in viral titer breakthrough. Resistance mapped to the loss of multiple potential N-linked glycosylation sites in gp120, suggesting that inhibition is due to steric hindrance of CD4-binding-induced conformational changes.
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27
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Zaitseva E, Zaitsev E, Melikov K, Arakelyan A, Marin M, Villasmil R, Margolis LB, Melikyan GB, Chernomordik LV. Fusion Stage of HIV-1 Entry Depends on Virus-Induced Cell Surface Exposure of Phosphatidylserine. Cell Host Microbe 2017; 22:99-110.e7. [PMID: 28704658 PMCID: PMC5558241 DOI: 10.1016/j.chom.2017.06.012] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 03/13/2017] [Accepted: 06/22/2017] [Indexed: 12/18/2022]
Abstract
HIV-1 entry into host cells starts with interactions between the viral envelope glycoprotein (Env) and cellular CD4 receptors and coreceptors. Previous work has suggested that efficient HIV entry also depends on intracellular signaling, but this remains controversial. Here we report that formation of the pre-fusion Env-CD4-coreceptor complexes triggers non-apoptotic cell surface exposure of the membrane lipid phosphatidylserine (PS). HIV-1-induced PS redistribution depends on Ca2+ signaling triggered by Env-coreceptor interactions and involves the lipid scramblase TMEM16F. Externalized PS strongly promotes Env-mediated membrane fusion and HIV-1 infection. Blocking externalized PS or suppressing TMEM16F inhibited Env-mediated fusion. Exogenously added PS promoted fusion, with fusion dependence on PS being especially strong for cells with low surface density of coreceptors. These findings suggest that cell-surface PS acts as an important cofactor that promotes the fusogenic restructuring of pre-fusion complexes and likely focuses the infection on cells conducive to PS signaling.
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Affiliation(s)
- Elena Zaitseva
- Section on Membrane Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Eugene Zaitsev
- Section on Membrane Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Kamran Melikov
- Section on Membrane Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Anush Arakelyan
- Section on Intercellular Interactions, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Mariana Marin
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Rafael Villasmil
- Flow Cytometry Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Leonid B Margolis
- Section on Intercellular Interactions, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Gregory B Melikyan
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Leonid V Chernomordik
- Section on Membrane Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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28
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Banerjee S, Shi H, Banasik M, Moon H, Lees W, Qin Y, Harley A, Shepherd A, Cho MW. Evaluation of a novel multi-immunogen vaccine strategy for targeting 4E10/10E8 neutralizing epitopes on HIV-1 gp41 membrane proximal external region. Virology 2017; 505:113-126. [PMID: 28237764 DOI: 10.1016/j.virol.2017.02.015] [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: 01/13/2017] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 02/01/2023]
Abstract
The membrane proximal external region (MPER) of HIV-1 gp41 is targeted by broadly neutralizing antibodies (bnAbs) 4E10 and 10E8. In this proof-of-concept study, we evaluated a novel multi-immunogen vaccine strategy referred to as Incremental, Phased Antigenic Stimulation for Rapid Antibody Maturation (IPAS-RAM) to induce 4E10/10E8-like bnAbs. Rabbits were immunized sequentially, but in a phased manner, with three immunogens that are progressively more native (gp41-28×3, gp41-54CT, and rVV-gp160DH12). Although nAbs were not induced, epitope-mapping analyses indicated that IPAS-RAM vaccination was better able to target antibodies towards the 4E10/10E8 epitopes than homologous prime-boost immunization using gp41-28×3 alone. MPER-specific rabbit monoclonal antibodies were generated, including 9F6. Although it lacked neutralizing activity, the target epitope profile of 9F6 closely resembled those of 4E10 and 10E8 (671NWFDITNWLWYIK683). B-cell repertoire analyses suggested the importance of co-immunizations for maturation of 9F6, which warrants further evaluation of our IPAS-RAM vaccine strategy using an improved priming immunogen.
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Affiliation(s)
- Saikat Banerjee
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States
| | - Heliang Shi
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States
| | - Marisa Banasik
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States
| | - Hojin Moon
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States
| | - William Lees
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, UK
| | - Yali Qin
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States
| | - Andrew Harley
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States
| | - Adrian Shepherd
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, UK
| | - Michael W Cho
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States.
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29
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Abstract
It is clear that antibodies can play a pivotal role in preventing the transmission of HIV-1 and large efforts to identify an effective antibody-based vaccine to quell the epidemic. Shortly after HIV-1 was discovered as the cause of AIDS, the search for epitopes recognized by neutralizing antibodies became the driving strategy for an antibody-based vaccine. Neutralization escape variants were discovered shortly thereafter, and, after almost three decades of investigation, it is now known that autologous neutralizing antibody responses and their selection of neutralization resistant HIV-1 variants can lead to broadly neutralizing antibodies in some infected individuals. This observation drives an intensive effort to identify a vaccine to elicit broadly neutralizing antibodies. In contrast, there has been less systematic study of antibody specificities that must rely mainly or exclusively on other protective mechanisms, although non-human primate (NHP) studies as well as the RV144 vaccine trial indicate that non-neutralizing antibodies can contribute to protection. Here we propose a novel strategy to identify new epitope targets recognized by these antibodies for which viral escape is unlikely or impossible.
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Affiliation(s)
- George K Lewis
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Marzena Pazgier
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Anthony L DeVico
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
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30
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Yi HA, Fochtman BC, Rizzo RC, Jacobs A. Inhibition of HIV Entry by Targeting the Envelope Transmembrane Subunit gp41. Curr HIV Res 2016; 14:283-94. [PMID: 26957202 DOI: 10.2174/1570162x14999160224103908] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 09/23/2015] [Accepted: 09/30/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND The transmembrane subunit of the HIV envelope protein, gp41 is a vulnerable target to inhibit HIV entry. There is one fusion inhibitor T20 (brand name: Fuzeon, generic name: enfuvirtide) available by prescription. However, it has several drawbacks such as a high level of development of drug resistance, a short-half life in vivo, rapid renal clearance, low oral bioavailability, and it is only used as a salvage therapy. Therefore, investigators have been studying a variety of different modalities to attempt to overcome these limitations. METHODS Comprehensive literature searches were performed on HIV gp41, inhibition mechanisms, and inhibitors. The latest structural information was collected, and multiple inhibition strategies targeting gp41 were reviewed. RESULTS Many of the recent advances in inhibitors were peptide-based. Several creative modification strategies have also been performed to improve inhibitory efficacy of peptides and to overcome the drawbacks of T20 treatment. Small compounds have also been an area of intense research. There is a wide variety in development from those identified by virtual screens targeting specific regions of the protein to natural products. Finally, broadly neutralizing antibodies have also been important area of research. The inaccessible nature of the target regions for antibodies is a challenge, however, extensive efforts to develop better neutralizing antibodies are ongoing. CONCLUSION The fusogenic protein, gp41 has been extensively studied as a promising target to inhibit membrane fusion between the virus and target cells. At the same time, it is a challenging target because the vulnerable conformations of the protein are exposed only transiently. However, advances in biochemical, biophysical, structural, and immunological studies are coming together to move the field closer to an understanding of gp41 structure and function that will lead to the development of novel drugs and vaccines.
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Affiliation(s)
| | | | | | - Amy Jacobs
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA.
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31
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Becerra JC, Bildstein LS, Gach JS. Recent Insights into the HIV/AIDS Pandemic. MICROBIAL CELL (GRAZ, AUSTRIA) 2016; 3:451-475. [PMID: 28357381 PMCID: PMC5354571 DOI: 10.15698/mic2016.09.529] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 04/27/2016] [Indexed: 12/21/2022]
Abstract
Etiology, transmission and protection: Transmission of HIV, the causative agent of AIDS, occurs predominantly through bodily fluids. Factors that significantly alter the risk of HIV transmission include male circumcision, condom use, high viral load, and the presence of other sexually transmitted diseases. Pathology/Symptomatology: HIV infects preferentially CD4+ T lymphocytes, and Monocytes. Because of their central role in regulating the immune response, depletion of CD4+ T cells renders the infected individual incapable of adequately responding to microorganisms otherwise inconsequential. Epidemiology, incidence and prevalence: New HIV infections affect predominantly young heterosexual women and homosexual men. While the mortality rates of AIDS related causes have decreased globally in recent years due to the use of highly active antiretroviral therapy (HAART) treatment, a vaccine remains an elusive goal. Treatment and curability: For those afflicted HIV infection remains a serious illness. Nonetheless, the use of advanced therapeutics have transformed a dire scenario into a chronic condition with near average life spans. When to apply those remedies appears to be as important as the remedies themselves. The high rate of HIV replication and the ability to generate variants are central to the viral survival strategy and major barriers to be overcome. Molecular mechanisms of infection: In this review, we assemble new details on the molecular events from the attachment of the virus, to the assembly and release of the viral progeny. Yet, much remains to be learned as understanding of the molecular mechanisms used in viral replication and the measures engaged in the evasion of immune surveillance will be important to develop effective interventions to address the global HIV pandemic.
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Affiliation(s)
- Juan C. Becerra
- Department of Medicine, Division of Infectious Diseases, University
of California, Irvine, Irvine, CA 92697, USA
| | | | - Johannes S. Gach
- Department of Medicine, Division of Infectious Diseases, University
of California, Irvine, Irvine, CA 92697, USA
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32
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Abstract
The HIV genome encodes a small number of viral proteins (i.e., 16), invariably establishing cooperative associations among HIV proteins and between HIV and host proteins, to invade host cells and hijack their internal machineries. As a known example, the HIV envelope glycoprotein GP120 is closely associated with GP41 for viral entry. From a genome-wide perspective, a hypothesis can be worked out to determine whether 16 HIV proteins could develop 120 possible pairwise associations either by physical interactions or by functional associations mediated via HIV or host molecules. Here, we present the first systematic review of experimental evidence on HIV genome-wide protein associations using a large body of publications accumulated over the past 3 decades. Of 120 possible pairwise associations between 16 HIV proteins, at least 34 physical interactions and 17 functional associations have been identified. To achieve efficient viral replication and infection, HIV protein associations play essential roles (e.g., cleavage, inhibition, and activation) during the HIV life cycle. In either a dispensable or an indispensable manner, each HIV protein collaborates with another viral protein to accomplish specific activities that precisely take place at the proper stages of the HIV life cycle. In addition, HIV genome-wide protein associations have an impact on anti-HIV inhibitors due to the extensive cross talk between drug-inhibited proteins and other HIV proteins. Overall, this study presents for the first time a comprehensive overview of HIV genome-wide protein associations, highlighting meticulous collaborations between all viral proteins during the HIV life cycle.
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Affiliation(s)
- Guangdi Li
- Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China KU Leuven-University of Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Leuven, Belgium
| | - Erik De Clercq
- KU Leuven-University of Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Leuven, Belgium
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33
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Wang Q, Wong G, Lu G, Yan J, Gao GF. MERS-CoV spike protein: Targets for vaccines and therapeutics. Antiviral Res 2016; 133:165-77. [PMID: 27468951 PMCID: PMC7113765 DOI: 10.1016/j.antiviral.2016.07.015] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/07/2016] [Accepted: 07/22/2016] [Indexed: 02/05/2023]
Abstract
The disease outbreak caused by Middle East respiratory syndrome coronavirus (MERS-CoV) is still ongoing in the Middle East. Over 1700 people have been infected since it was first reported in September 2012. Despite great efforts, licensed vaccines or therapeutics against MERS-CoV remain unavailable. The MERS-CoV spike (S) protein is an important viral antigen known to mediate host-receptor binding and virus entry, as well as induce robust humoral and cell-mediated responses in humans during infection. In this review, we highlight the importance of the S protein in the MERS-CoV life cycle, summarize recent advances in the development of vaccines and therapeutics based on the S protein, and discuss strategies that can be explored to develop new medical countermeasures against MERS-CoV. A licensed vaccine or therapeutic against MERS-CoV remains unavailable to date. The S protein plays a pivotal role for virus entry and thus is an ideal target for vaccine and antiviral development. DNA vaccines expressing the S protein merit further development for potential human application. nAbs and peptides targeting the S protein needs to be evaluated in NHPs before clinical trials.
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MESH Headings
- Animals
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/immunology
- Antiviral Agents/pharmacology
- Antiviral Agents/therapeutic use
- Coronavirus Infections/prevention & control
- Coronavirus Infections/therapy
- Drug Discovery
- Humans
- Middle East Respiratory Syndrome Coronavirus/immunology
- Middle East Respiratory Syndrome Coronavirus/physiology
- Receptors, Virus/chemistry
- Receptors, Virus/metabolism
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/genetics
- Spike Glycoprotein, Coronavirus/immunology
- Spike Glycoprotein, Coronavirus/metabolism
- Structure-Activity Relationship
- Vaccines, DNA/immunology
- Vaccines, Subunit/immunology
- Vaccines, Virus-Like Particle/immunology
- Viral Vaccines/immunology
- Virus Internalization
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Affiliation(s)
- Qihui Wang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China.
| | - Gary Wong
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China
| | - Guangwen Lu
- West China Hospital Emergency Department (WCHED), State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu, Sichuan 610041, China
| | - Jinghua Yan
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - George F Gao
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310003, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China.
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34
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HIV Genome-Wide Protein Associations: a Review of 30 Years of Research. Microbiol Mol Biol Rev 2016; 80:679-731. [PMID: 27357278 DOI: 10.1128/mmbr.00065-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The HIV genome encodes a small number of viral proteins (i.e., 16), invariably establishing cooperative associations among HIV proteins and between HIV and host proteins, to invade host cells and hijack their internal machineries. As a known example, the HIV envelope glycoprotein GP120 is closely associated with GP41 for viral entry. From a genome-wide perspective, a hypothesis can be worked out to determine whether 16 HIV proteins could develop 120 possible pairwise associations either by physical interactions or by functional associations mediated via HIV or host molecules. Here, we present the first systematic review of experimental evidence on HIV genome-wide protein associations using a large body of publications accumulated over the past 3 decades. Of 120 possible pairwise associations between 16 HIV proteins, at least 34 physical interactions and 17 functional associations have been identified. To achieve efficient viral replication and infection, HIV protein associations play essential roles (e.g., cleavage, inhibition, and activation) during the HIV life cycle. In either a dispensable or an indispensable manner, each HIV protein collaborates with another viral protein to accomplish specific activities that precisely take place at the proper stages of the HIV life cycle. In addition, HIV genome-wide protein associations have an impact on anti-HIV inhibitors due to the extensive cross talk between drug-inhibited proteins and other HIV proteins. Overall, this study presents for the first time a comprehensive overview of HIV genome-wide protein associations, highlighting meticulous collaborations between all viral proteins during the HIV life cycle.
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35
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Line tension at lipid phase boundaries as driving force for HIV fusion peptide-mediated fusion. Nat Commun 2016; 7:11401. [PMID: 27113279 PMCID: PMC4853434 DOI: 10.1038/ncomms11401] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/18/2016] [Indexed: 01/04/2023] Open
Abstract
Lipids and proteins are organized in cellular membranes in clusters, often called ‘lipid rafts'. Although raft-constituent ordered lipid domains are thought to be energetically unfavourable for membrane fusion, rafts have long been implicated in many biological fusion processes. For the case of HIV gp41-mediated membrane fusion, this apparent contradiction can be resolved by recognizing that the interfaces between ordered and disordered lipid domains are the predominant sites of fusion. Here we show that line tension at lipid domain boundaries contributes significant energy to drive gp41-fusion peptide-mediated fusion. This energy, which depends on the hydrophobic mismatch between ordered and disordered lipid domains, may contribute tens of kBT to fusion, that is, it is comparable to the energy required to form a lipid stalk intermediate. Line-active compounds such as vitamin E lower line tension in inhomogeneous membranes, thereby inhibit membrane fusion, and thus may be useful natural viral entry inhibitors. HIV preferentially fuses with lipid membranes at the interface between ordered and disordered domains, but the mechanistic basis for this observation is not known. Here Yang et al. show that line tension at the lipid boundary contributes considerable energy to drive gp41 fusion peptide-mediated fusion.
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Bibi Z, Ahmad J, Ali A, Siddiqa A, Shahzad S, Tareen SHK, Janjua HA, Khusro S. On the modeling and analysis of the biological regulatory network of NF-$${\kappa }$$B activation in HIV-1 infection. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s40294-015-0013-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Abstract
Purpose
The complex interactions between genetic machinery of HIV-1 and host immune cells mediate dynamic adaptive responses leading to Autoimmune Deficiency Syndrome. These interactions are captured as Biological Regulatory Network (BRN) which acts to maintain the viability of host cell machinery through feedback control mechanism which is a characteristic of complex adaptive systems. In this study, the BRN of immune response against HIV-1 infection is modeled to investigate the role of NF-κB and TNF-α in disease transmission using qualitative (discrete) and hybrid modeling formalisms.
Methods
Qualitative and Hybrid modeling approaches are used to model the BRN for the dynamic analysis. The qualitative model is based on the logical parameters while the hybrid model is based on the time delay parameters.
Results
The qualitative model gives useful insights about the physiological condition observed as the homeostasis of all the entities of the BRN as well as pathophysiological behaviors representing high expression levels of NF-κB, TNF-α and HIV. Since the qualitative model is time abstracted, so a hybrid model is developed to analyze the behavior of the BRN by associating activation and inhibition time delays with each entity. HyTech tool synthesizes time delay constraints for the existence of homeostasis.
Conclusion
Hybrid model reveals various viability constraints that characterize the conditional existence of cyclic states (homeostasis). The resultant relations suggest larger cycle period of HIV-1 than the cycle periods of the other two entities (NF-κB and TNF-α) to maintain a homeostatic expressions of these entities.
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Louis JM, Baber JL, Clore GM. The C34 Peptide Fusion Inhibitor Binds to the Six-Helix Bundle Core Domain of HIV-1 gp41 by Displacement of the C-Terminal Helical Repeat Region. Biochemistry 2015; 54:6796-805. [PMID: 26506247 DOI: 10.1021/acs.biochem.5b01021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conformational transition of the core domain of HIV-1 gp41 from a prehairpin intermediate to a six-helix bundle is responsible for virus-cell fusion. Several inhibitors which target the N-heptad repeat helical coiled-coil trimer that is fully accessible in the prehairpin intermediate have been designed. One such inhibitor is the peptide C34 derived from the C-heptad repeat of gp41 that forms the exterior of the six-helix bundle. Here, using a variety of biophysical techniques, including dye tagging, size-exclusion chromatography combined with multiangle light scattering, double electron-electron resonance EPR spectroscopy, and circular dichroism, we investigate the binding of C34 to two six-helix bundle mimetics comprising N- and C-heptad repeats either without (core(SP)) or with (core(S)) a short spacer connecting the two. In the case of core(SP), C34 directly exchanges with the C-heptad repeat. For core(S), up to two molecules of C34 bind the six-helix bundle via displacement of the C-heptad repeat. These results suggest that fusion inhibitors such as C34 can target a continuum of transitioning conformational states from the prehairpin intermediate to the six-helix bundle prior to the occurrence of irreversible fusion of viral and target cell membranes.
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Affiliation(s)
- John M Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892-0520, United States
| | - James L Baber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892-0520, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892-0520, United States
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Habte HH, Banerjee S, Shi H, Qin Y, Cho MW. Immunogenic properties of a trimeric gp41-based immunogen containing an exposed membrane-proximal external region. Virology 2015; 486:187-97. [PMID: 26454663 DOI: 10.1016/j.virol.2015.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/09/2015] [Accepted: 09/22/2015] [Indexed: 01/15/2023]
Abstract
The membrane-proximal external region (MPER) of HIV-1 gp41 is an attractive target for vaccine development. Thus, better understanding of its immunogenic properties in various structural contexts is important. We previously described the crystal structure of a trimeric protein complex named gp41-HR1-54Q, which consists of the heptad repeat regions 1 and 2 and the MPER. The protein was efficiently recognized by broadly neutralizing antibodies. Here, we describe its immunogenic properties in rabbits. The protein was highly immunogenic, especially the C-terminal end of the MPER containing 4E10 and 10E8 epitopes ((671)NWFDITNWLWYIK(683)). Although antibodies exhibited strong competition activity against 4E10 and 10E8, neutralizing activity was not detected. Detailed mapping analyses indicated that amino acid residues critical for recognition resided on faces of the alpha helix that are either opposite of or perpendicular to the epitopes recognized by 4E10 and 10E8. These results provide critical information for designing the next generation of MPER-based immunogens.
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Affiliation(s)
- Habtom H Habte
- College of Veterinary Medicine, Department of Biomedical Sciences, Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, 1600 S 16th Street, Ames, IA 50011-1250, USA
| | - Saikat Banerjee
- College of Veterinary Medicine, Department of Biomedical Sciences, Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, 1600 S 16th Street, Ames, IA 50011-1250, USA
| | - Heliang Shi
- College of Veterinary Medicine, Department of Biomedical Sciences, Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, 1600 S 16th Street, Ames, IA 50011-1250, USA
| | - Yali Qin
- College of Veterinary Medicine, Department of Biomedical Sciences, Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, 1600 S 16th Street, Ames, IA 50011-1250, USA
| | - Michael W Cho
- College of Veterinary Medicine, Department of Biomedical Sciences, Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, 1600 S 16th Street, Ames, IA 50011-1250, USA.
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Read J, Clancy EK, Sarker M, de Antueno R, Langelaan DN, Parmar HB, Shin K, Rainey JK, Duncan R. Reovirus FAST Proteins Drive Pore Formation and Syncytiogenesis Using a Novel Helix-Loop-Helix Fusion-Inducing Lipid Packing Sensor. PLoS Pathog 2015; 11:e1004962. [PMID: 26061049 PMCID: PMC4464655 DOI: 10.1371/journal.ppat.1004962] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 05/18/2015] [Indexed: 02/07/2023] Open
Abstract
Pore formation is the most energy-demanding step during virus-induced membrane fusion, where high curvature of the fusion pore rim increases the spacing between lipid headgroups, exposing the hydrophobic interior of the membrane to water. How protein fusogens breach this thermodynamic barrier to pore formation is unclear. We identified a novel fusion-inducing lipid packing sensor (FLiPS) in the cytosolic endodomain of the baboon reovirus p15 fusion-associated small transmembrane (FAST) protein that is essential for pore formation during cell-cell fusion and syncytiogenesis. NMR spectroscopy and mutational studies indicate the dependence of this FLiPS on a hydrophobic helix-loop-helix structure. Biochemical and biophysical assays reveal the p15 FLiPS preferentially partitions into membranes with high positive curvature, and this partitioning is impeded by bis-ANS, a small molecule that inserts into hydrophobic defects in membranes. Most notably, the p15 FLiPS can be functionally replaced by heterologous amphipathic lipid packing sensors (ALPS) but not by other membrane-interactive amphipathic helices. Furthermore, a previously unrecognized amphipathic helix in the cytosolic domain of the reptilian reovirus p14 FAST protein can functionally replace the p15 FLiPS, and is itself replaceable by a heterologous ALPS motif. Anchored near the cytoplasmic leaflet by the FAST protein transmembrane domain, the FLiPS is perfectly positioned to insert into hydrophobic defects that begin to appear in the highly curved rim of nascent fusion pores, thereby lowering the energy barrier to stable pore formation. The fusogenic ortho- and aquareoviruses are the only known nonenveloped viruses that induce syncytium formation. Cell-cell fusion is a virulence determinant of fusogenic reoviruses, and is mediated by a singular family of fusion-associated small transmembrane (FAST) proteins, the smallest known viral fusogens. Unlike their enveloped virus counterparts, reovirus FAST proteins have exceptionally small ectodomains and considerable larger cytoplasmic endodomains, suggesting FAST protein interactions with the cytoplasmic leaflet of the plasma membrane likely play a prominent role in the fusion process. We determined that the baboon reovirus p15 FAST protein endodomain contains a novel type of helix-loop-helix lipid packing sensor that partitions into hydrophobic defects present in highly curved membranes. This fusion-inducing lipid packing sensor (FLiPS) is required for pore formation, and can be functionally replaced by heterologous lipid packing sensors. By masking hydrophobic defects appearing in the highly curved rim of nascent fusion pores, the FliPS would make the forward reaction to pore formation a more energetically favored means of resolving an unstable hemifusion intermediate. These results define a new role for curvature sensing motifs, and reveal how viral fusion proteins can drive pore formation without having to rely on membrane stresses induced by complex refolding of large ectodomains.
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Affiliation(s)
- Jolene Read
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Eileen K. Clancy
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Muzaddid Sarker
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Roberto de Antueno
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David N. Langelaan
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hiren B. Parmar
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kyungsoo Shin
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jan K. Rainey
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Roy Duncan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail:
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Marin M, Du Y, Giroud C, Kim JH, Qui M, Fu H, Melikyan GB. High-Throughput HIV-Cell Fusion Assay for Discovery of Virus Entry Inhibitors. Assay Drug Dev Technol 2015; 13:155-66. [PMID: 25871547 DOI: 10.1089/adt.2015.639] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
HIV-1 initiates infection by merging its envelope membrane with the target cell membrane, a process that is mediated by the viral Env glycoprotein following its sequential binding to CD4 and coreceptors, CXCR4 or CCR5. Although HIV-1 fusion has been a target for antiviral therapy, the virus has developed resistance to drugs blocking the CCR5 binding or Env refolding steps of this process. This highlights the need for novel inhibitors. Here, we adapted and optimized an enzymatic HIV-cell fusion assay, which reports the transfer of virus-encapsulated β-lactamase into the cytoplasm, to high-throughput screening (HTS) with a 384-well format. The assay was robustly performed in HTS format and was validated by the pilot screen of a small library of pharmacologically active compounds. Several hits identified by screening included a prominent cluster of purinergic receptor antagonists. Functional studies demonstrated that P2X1 receptor antagonists selectively inhibited HIV-1 fusion without affecting the fusion activity of an unrelated virus that enters cells through an endocytic route. The inhibition of HIV-cell fusion by P2X1 antagonists was not through downmodulation of the cell surface expression of CD4 or coreceptors, thus implicating P2X1 receptor in the HIV-1 fusion step. The ability of these antagonists to inhibit viruses regardless of their coreceptor (CXCR4 or CCR5) preference indicates that fusion is blocked at a late step downstream of coreceptor binding. A future large-scale screening campaign for HIV-1 fusion inhibitors, using the above functional readout, will likely reveal novel classes of inhibitors and suggest potential targets for antiviral therapy.
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Affiliation(s)
- Mariana Marin
- 1 Division of Pediatric Infectious Diseases, Emory University Children's Center , Atlanta, Georgia
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41
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Kim JH, Ren Y, Ng WP, Li S, Son S, Kee YS, Zhang S, Zhang G, Fletcher DA, Robinson DN, Chen EH. Mechanical tension drives cell membrane fusion. Dev Cell 2015; 32:561-73. [PMID: 25684354 DOI: 10.1016/j.devcel.2015.01.005] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 11/14/2014] [Accepted: 01/10/2015] [Indexed: 01/05/2023]
Abstract
Membrane fusion is an energy-consuming process that requires tight juxtaposition of two lipid bilayers. Little is known about how cells overcome energy barriers to bring their membranes together for fusion. Previously, we have shown that cell-cell fusion is an asymmetric process in which an "attacking" cell drills finger-like protrusions into the "receiving" cell to promote cell fusion. Here, we show that the receiving cell mounts a Myosin II (MyoII)-mediated mechanosensory response to its invasive fusion partner. MyoII acts as a mechanosensor, which directs its force-induced recruitment to the fusion site, and the mechanosensory response of MyoII is amplified by chemical signaling initiated by cell adhesion molecules. The accumulated MyoII, in turn, increases cortical tension and promotes fusion pore formation. We propose that the protrusive and resisting forces from fusion partners put the fusogenic synapse under high mechanical tension, which helps to overcome energy barriers for membrane apposition and drives cell membrane fusion.
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Affiliation(s)
- Ji Hoon Kim
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yixin Ren
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Win Pin Ng
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shuo Li
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sungmin Son
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Yee-Seir Kee
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Shiliang Zhang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guofeng Zhang
- Laboratory of Bioengineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD 20892, USA
| | - Daniel A Fletcher
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Douglas N Robinson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth H Chen
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Apellániz B, Nieva JL. Fusion-competent state induced by a C-terminal HIV-1 fusion peptide in cholesterol-rich membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1014-22. [PMID: 25617671 DOI: 10.1016/j.bbamem.2015.01.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/15/2014] [Accepted: 01/14/2015] [Indexed: 11/17/2022]
Abstract
The replicative cycle of the human immunodeficiency virus type-1 begins after fusion of the viral and target-cell membranes. The envelope glycoprotein gp41 transmembrane subunit contains conserved hydrophobic domains that engage and perturb the merging lipid bilayers. In this work, we have characterized the fusion-committed state generated in vesicles by CpreTM, a synthetic peptide derived from the sequence connecting the membrane-proximal external region (MPER) and the transmembrane domain (TMD) of gp41. Pre-loading cholesterol-rich vesicles with CpreTM rendered them competent for subsequent lipid-mixing with fluorescently-labeled target vesicles. Highlighting the physiological relevance of the lasting fusion-competent state, the broadly neutralizing antibody 4E10 bound to the CpreTM-primed vesicles and inhibited lipid-mixing. Heterotypic fusion assays disclosed dependence on the lipid composition of the vesicles that acted either as virus or cell membrane surrogates. Lipid-mixing exhibited above all a critical dependence on the cholesterol content in those experiments. We infer that the fusion-competent state described herein resembles bona-fide perturbations generated by the pre-hairpin MPER-TMD connection within the viral membrane.
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Affiliation(s)
- Beatriz Apellániz
- Biophysics Unit (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain.
| | - José L Nieva
- Biophysics Unit (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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Different infectivity of HIV-1 strains is linked to number of envelope trimers required for entry. PLoS Pathog 2015; 11:e1004595. [PMID: 25569556 PMCID: PMC4287578 DOI: 10.1371/journal.ppat.1004595] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 12/02/2014] [Indexed: 12/13/2022] Open
Abstract
HIV-1 enters target cells by virtue of envelope glycoprotein trimers that are incorporated at low density in the viral membrane. How many trimers are required to interact with target cell receptors to mediate virus entry, the HIV entry stoichiometry, still awaits clarification. Here, we provide estimates of the HIV entry stoichiometry utilizing a combined approach of experimental analyses and mathematical modeling. We demonstrate that divergent HIV strains differ in their stoichiometry of entry and require between 1 to 7 trimers, with most strains depending on 2 to 3 trimers to complete infection. Envelope modifications that perturb trimer structure lead to an increase in the entry stoichiometry, as did naturally occurring antibody or entry inhibitor escape mutations. Highlighting the physiological relevance of our findings, a high entry stoichiometry correlated with low virus infectivity and slow virus entry kinetics. The entry stoichiometry therefore directly influences HIV transmission, as trimer number requirements will dictate the infectivity of virus populations and efficacy of neutralizing antibodies. Thereby our results render consideration of stoichiometric concepts relevant for developing antibody-based vaccines and therapeutics against HIV. Our estimates of the HIV-1 entry stoichiometry, that is the number of envelope glycoprotein trimers needed to mediate fusion of viral and target cell membrane, close an important gap in our understanding of the HIV entry process. As we show, stoichiometric requirements for envelope trimers differ between HIV strains and steer virus entry efficacy and virus entry kinetics. Thus, the entry stoichiometry has important implications for HIV transmission, as demands on trimer numbers will dictate the infectivity of virus populations, target cell preferences and virus inactivation by trimer-targeting inhibitors and neutralizing antibodies. Beyond this, our data contribute to the general understanding of mechanisms and energetic requirements of protein-mediated membrane fusion, as HIV entry proved to follow similar stoichiometries as described for Influenza virus HA and SNARE protein mediated membrane fusion. In summary, our findings provide a relevant contribution towards a refined understanding of HIV-1 entry and pathogenesis with particular importance for ongoing efforts to generate neutralizing antibody based therapeutics and vaccines targeting the HIV-1 envelope trimer.
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de Goede AL, Vulto AG, Osterhaus ADME, Gruters RA. Understanding HIV infection for the design of a therapeutic vaccine. Part I: Epidemiology and pathogenesis of HIV infection. ANNALES PHARMACEUTIQUES FRANÇAISES 2014; 73:87-99. [PMID: 25496723 DOI: 10.1016/j.pharma.2014.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 11/01/2014] [Accepted: 11/07/2014] [Indexed: 02/07/2023]
Abstract
HIV infection leads to a gradual loss CD4+ T lymphocytes comprising immune competence and progression to AIDS. Effective treatment with combined antiretroviral drugs (cART) decreases viral load below detectable levels but is not able to eliminate the virus from the body. The success of cART is frustrated by the requirement of expensive life-long adherence, accumulating drug toxicities and chronic immune activation resulting in increased risk of several non-AIDS disorders, even when viral replication is suppressed. Therefore there is a strong need for therapeutic strategies as an alternative to cART. Immunotherapy, or therapeutic vaccination, aims to increase existing immune responses against HIV or induce de novo immune responses. These immune responses should provide a functional cure by controlling viral replication and preventing disease progression in the absence of cART. The key difficulty in the development of an HIV vaccine is our ignorance of the immune responses that control of viral replication, and thus how these responses can be elicited and how they can be monitored. Part one of this review provides an extensive overview of the (patho-) physiology of HIV infection. It describes the structure and replication cycle of HIV, the epidemiology and pathogenesis of HIV infection and the innate and adaptive immune responses against HIV. Part two of this review discusses therapeutic options for HIV. Prevention modalities and antiretroviral therapy are briefly touched upon, after which an extensive overview on vaccination strategies for HIV is provided, including the choice of immunogens and delivery strategies.
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Affiliation(s)
- A L de Goede
- Department of Viroscience, Erasmus MC 's-Gravendijkwal 230, 2040, 3000 CA Rotterdam, The Netherlands; Department of Hospital Pharmacy, Erasmus MC 's-Gravendijkwal 230, 2040, 3000 CA Rotterdam, The Netherlands.
| | - A G Vulto
- Department of Hospital Pharmacy, Erasmus MC 's-Gravendijkwal 230, 2040, 3000 CA Rotterdam, The Netherlands
| | - A D M E Osterhaus
- Department of Viroscience, Erasmus MC 's-Gravendijkwal 230, 2040, 3000 CA Rotterdam, The Netherlands
| | - R A Gruters
- Department of Viroscience, Erasmus MC 's-Gravendijkwal 230, 2040, 3000 CA Rotterdam, The Netherlands
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Klasse PJ. Molecular determinants of the ratio of inert to infectious virus particles. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 129:285-326. [PMID: 25595808 DOI: 10.1016/bs.pmbts.2014.10.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The ratio of virus particles to infectious units is a classic measurement in virology and ranges widely from several million to below 10 for different viruses. Much evidence suggests a distinction be made between infectious and infecting particles or virions: out of many potentially infectious virions, few infect under regular experimental conditions, largely because of diffusion barriers. Still, some virions are inert from the start; others become defective through decay. And with increasing cell- and molecular-biological knowledge of each step in the replicative cycle for different viruses, it emerges that many processes entail considerable losses of potential viral infectivity. Furthermore, all-or-nothing assumptions about virion infectivity are flawed and should be replaced by descriptions that allow for spectra of infectious propensities. A more realistic understanding of the infectivity of individual virions has both practical and theoretical implications for virus neutralization, vaccine research, antiviral therapy, and the use of viral vectors.
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Affiliation(s)
- P J Klasse
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, USA.
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Lorenz IC, Nguyen HT, Kemelman M, Lindsay RW, Yuan M, Wright KJ, Arendt H, Back JW, DeStefano J, Hoffenberg S, Morrow G, Jurgens CK, Phogat SK, Zamb TJ, Parks CL. The stem of vesicular stomatitis virus G can be replaced with the HIV-1 Env membrane-proximal external region without loss of G function or membrane-proximal external region antigenic properties. AIDS Res Hum Retroviruses 2014; 30:1130-44. [PMID: 24597516 DOI: 10.1089/aid.2013.0206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The structure of the HIV-1 envelope membrane-proximal external region (MPER) is influenced by its association with the lipid bilayer on the surface of virus particles and infected cells. To develop a replicating vaccine vector displaying MPER sequences in association with membrane, Env epitopes recognized by the broadly neutralizing antibodies 2F5, 4E10, or both were grafted into the membrane-proximal stem region of the vesicular stomatitis virus (VSV) glycoprotein (G). VSV encoding functional G-MPER chimeras based on G from the Indiana or New Jersey serotype propagated efficiently, although grafting of both epitopes (G-2F5-4E10) modestly reduced replication and resulted in the acquisition of one to two adaptive mutations in the grafted MPER sequence. Monoclonal antibodies 2F5 and 4E10 efficiently neutralized VSV G-MPER vectors and bound to virus particles in solution, indicating that the epitopes were accessible in the preattachment form of the G-MPER chimeras. Overall, our results showed that the HIV Env MPER could functionally substitute for the VSV G-stem region implying that both perform similar functions even though they are from unrelated viruses. Furthermore, we found that the MPER sequence grafts induced low but detectable MPER-specific antibody responses in rabbits vaccinated with live VSV, although additional vector and immunogen modifications or use of a heterologous prime-boost vaccination regimen will be required to increase the magnitude of the immune response.
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Affiliation(s)
- Ivo C. Lorenz
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Hanh T. Nguyen
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
- Program in Molecular and Cellular Biology, School of Graduate Studies, The State University of New York Downstate Medical Center, Brooklyn, New York
| | - Marina Kemelman
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Ross W. Lindsay
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Maoli Yuan
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Kevin J. Wright
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Heather Arendt
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | | | - Joanne DeStefano
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Simon Hoffenberg
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Gavin Morrow
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Christy K. Jurgens
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Sanjay K. Phogat
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Timothy J. Zamb
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
| | - Christopher L. Parks
- The International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York
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Meng Q, Dong T, Chen X, Tong B, Qian X, Che J, Cheng Y. Pharmacokinetics of sifuvirtide in treatment-naive and treatment-experienced HIV-infected patients. J Pharm Sci 2014; 103:4038-4047. [PMID: 25291974 DOI: 10.1002/jps.24174] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 08/21/2014] [Accepted: 08/21/2014] [Indexed: 11/06/2022]
Abstract
The pharmacokinetics assessment in two clinical studies of sifuvirtide (a novel HIV fusion inhibitor) was first reported in Chinese HIV patients. Nineteen treatment-naive HIV patients were treated with s.c.(subcutaneous injection) sifuvirtide [10 or 20 mg q.d.(quaque die)] for 28 days in study 1, and eight treatment-experienced HIV patients were treated with s.c. sifuvirtide (20 mg q.d.) in combination with HAART drugs (lamivudine, didanosine, and Kaletra) for 168 days in study 2. In study 1, T1/2 was 17.8 ± 3.7 h for 10 mg group and 39.0 ± 3.5 h for 20 mg group; the mean Cmax of last dose was 498 ± 54 ng/mL for 10 mg group and 897 ± 136 ng/mL for 20 mg group. In study 2, T1/2 was 6.71 ± 2.17 h in treatment-experienced patients. Cmax was 765 ± 288 ng/mL after last 168th dosage. Sifuvirtide showed improved clinical pharmacokinetics characteristics compared with Enfuvirtide, and showed very different pharmacokinetic characteristics between treatment-naive and treatment-experienced patients. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:4038-4047, 2014.
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Affiliation(s)
- Qingfang Meng
- School of Life Science, Beijing Institute of Technology, Beijing 100081, People's Republic of China; Lab of Drug Metabolism and Pharmacokineticsm, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People's Republic of China
| | - Tianhao Dong
- FusoGen Pharmaceuticals, Inc, Tianjin 300308, People's Republic of China
| | - Xin Chen
- FusoGen Pharmaceuticals, Inc, Tianjin 300308, People's Republic of China
| | - Baohui Tong
- Lab of Drug Metabolism and Pharmacokineticsm, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People's Republic of China
| | - Xiaohong Qian
- School of Life Science, Beijing Institute of Technology, Beijing 100081, People's Republic of China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 102206, People's Republic of China
| | - Jinjing Che
- Lab of Drug Metabolism and Pharmacokineticsm, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People's Republic of China.
| | - Yuanguo Cheng
- Lab of Drug Metabolism and Pharmacokineticsm, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People's Republic of China
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Cholesterol-dependent membrane fusion induced by the gp41 membrane-proximal external region-transmembrane domain connection suggests a mechanism for broad HIV-1 neutralization. J Virol 2014; 88:13367-77. [PMID: 25210180 DOI: 10.1128/jvi.02151-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The HIV-1 glycoprotein 41 promotes fusion of the viral membrane with that of the target cell. Structural, biochemical, and biophysical studies suggest that its membrane-proximal external region (MPER) may interact with the HIV-1 membrane and induce its disruption and/or deformation during the process. However, the high cholesterol content of the envelope (ca. 40 to 50 mol%) imparts high rigidity, thereby acting against lipid bilayer restructuring. Here, based on the outcome of vesicle stability assays, all-atom molecular dynamics simulations, and atomic force microscopy observations, we propose that the conserved sequence connecting the MPER with the N-terminal residues of the transmembrane domain (TMD) is involved in HIV-1 fusion. This junction would function by inducing phospholipid protrusion and acyl-chain splay in the cholesterol-enriched rigid envelope. Supporting the functional relevance of such a mechanism, membrane fusion was inhibited by the broadly neutralizing 4E10 antibody but not by a nonneutralizing variant with the CDR-H3 loop deleted. We conclude that the MPER-TMD junction embodies an envelope-disrupting C-terminal fusion peptide that can be targeted by broadly neutralizing antibodies. IMPORTANCE Fusion of the cholesterol-enriched viral envelope with the cell membrane marks the beginning of the infectious HIV-1 replicative cycle. Consequently, the Env glycoprotein-mediated fusion function constitutes an important clinical target for inhibitors and preventive vaccines. Antibodies 4E10 and 10E8 bind to one Env vulnerability site located at the gp41 membrane-proximal external region (MPER)-transmembrane domain (TMD) junction and block infection. These antibodies display broad viral neutralization, which underscores the conservation and functionality of the MPER-TMD region. In this work, we combined biochemical assays with molecular dynamics simulations and microscopy observations to characterize the unprecedented fusogenic activity of the MPER-TMD junction. The fact that such activity is dependent on cholesterol and inhibited by the broadly neutralizing 4E10 antibody emphasizes its physiological relevance. Discovery of this functional element adds to our understanding of the mechanisms underlying HIV-1 infection and its blocking by antibodies.
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Neutralization of Virus Infectivity by Antibodies: Old Problems in New Perspectives. ACTA ACUST UNITED AC 2014; 2014. [PMID: 27099867 DOI: 10.1155/2014/157895] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neutralizing antibodies (NAbs) can be both sufficient and necessary for protection against viral infections, although they sometimes act in concert with cellular immunity. Successful vaccines against viruses induce NAbs but vaccine candidates against some major viral pathogens, including HIV-1, have failed to induce potent and effective such responses. Theories of how antibodies neutralize virus infectivity have been formulated and experimentally tested since the 1930s; and controversies about the mechanistic and quantitative bases for neutralization have continually arisen. Soluble versions of native oligomeric viral proteins that mimic the functional targets of neutralizing antibodies now allow the measurement of the relevant affinities of NAbs. Thereby the neutralizing occupancies on virions can be estimated and related to the potency of the NAbs. Furthermore, the kinetics and stoichiometry of NAb binding can be compared with neutralizing efficacy. Recently, the fundamental discovery that the intracellular factor TRIM21 determines the degree of neutralization of adenovirus has provided new mechanistic and quantitative insights. Since TRIM21 resides in the cytoplasm, it would not affect the neutralization of enveloped viruses, but its range of activity against naked viruses will be important to uncover. These developments bring together the old problems of virus neutralization-mechanism, stoichiometry, kinetics, and efficacy-from surprising new angles.
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Gong Z, Kessans SA, Song L, Dörner K, Lee HH, Meador LR, LaBaer J, Hogue BG, Mor TS, Fromme P. Recombinant expression, purification, and biophysical characterization of the transmembrane and membrane proximal domains of HIV-1 gp41. Protein Sci 2014; 23:1607-18. [PMID: 25155369 DOI: 10.1002/pro.2540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 07/22/2014] [Accepted: 08/20/2014] [Indexed: 11/07/2022]
Abstract
The transmembrane subunit (gp41) of the envelope glycoprotein of HIV-1 associates noncovalently with the surface subunit (gp120) and together they play essential roles in viral mucosal transmission and infection of target cells. The membrane proximal region (MPR) of gp41 is highly conserved and contains epitopes of broadly neutralizing antibodies. The transmembrane (TM) domain of gp41 not only anchors the envelope glycoprotein complex in the viral membrane but also dynamically affects the interactions of the MPR with the membrane. While high-resolution X-ray structures of some segments of the MPR were solved in the past, they represent the post-fusion forms. Structural information on the TM domain of gp41 is scant and at low resolution. Here we describe the design, expression and purification of a protein construct that includes MPR and the transmembrane domain of gp41 (MPR-TMTEV-6His), which reacts with the broadly neutralizing antibodies 2F5 and 4E10 and thereby may represent an immunologically relevant conformation mimicking a prehairpin intermediate of gp41. The expression level of MPR-TMTEV-6His was improved by fusion to the C-terminus of Mistic protein, yielding ∼ 1 mg of pure protein per liter. The isolated MPR-TMTEV-6His protein was biophysically characterized and is a monodisperse candidate for crystallization. This work will enable further investigation into the structure of MPR-TMTEV-6His, which will be important for the structure-based design of a mucosal vaccine against HIV-1.
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Affiliation(s)
- Zhen Gong
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, 85287-1604; The Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, 85287
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