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Bennett AL, Edwards R, Kosheleva I, Saunders C, Bililign Y, Williams A, Bubphamala P, Manosouri K, Anasti K, Saunders KO, Alam SM, Haynes BF, Acharya P, Henderson R. Microsecond dynamics control the HIV-1 Envelope conformation. SCIENCE ADVANCES 2024; 10:eadj0396. [PMID: 38306419 PMCID: PMC10836732 DOI: 10.1126/sciadv.adj0396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/03/2024] [Indexed: 02/04/2024]
Abstract
The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although remarkable progress has been made in understanding the structures of various Env conformations, microsecond timescale dynamics have not been studied experimentally. Here, we used time-resolved, temperature-jump small-angle x-ray scattering to monitor structural rearrangements in an HIV-1 Env SOSIP ectodomain construct with microsecond precision. In two distinct Env variants, we detected a transition that correlated with known Env structure rearrangements with a time constant in the hundreds of microseconds range. A previously unknown structural transition was also observed, which occurred with a time constant below 10 μs, and involved an order-to-disorder transition in the trimer apex. Using this information, we engineered an Env SOSIP construct that locks the trimer in the prefusion closed state by connecting adjacent protomers via disulfides. Our findings show that the microsecond timescale structural dynamics play an essential role in controlling the Env conformation with impacts on vaccine design.
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Affiliation(s)
- Ashley L. Bennett
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Robert Edwards
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Irina Kosheleva
- BioCARS, Center for Advanced Radiation Sources, The University of Chicago, 9700 South Cass Ave, Bld 434B, Lemont, IL 60439, USA
| | - Carrie Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Yishak Bililign
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Ashliegh Williams
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Pimthada Bubphamala
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Katayoun Manosouri
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kara Anasti
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kevin O. Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - S. Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
- Department of Pathology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- BioCARS, Center for Advanced Radiation Sources, The University of Chicago, 9700 South Cass Ave, Bld 434B, Lemont, IL 60439, USA
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Rory Henderson
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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2
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Bennett AL, Edwards RJ, Kosheleva I, Saunders C, Bililign Y, Williams A, Manosouri K, Saunders KO, Haynes BF, Acharya P, Henderson R. Microsecond dynamics control the HIV-1 envelope conformation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.17.541130. [PMID: 37292605 PMCID: PMC10245784 DOI: 10.1101/2023.05.17.541130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although significant progress has been made in understanding the structures of various Env conformations and transition intermediates that occur within the millisecond timescale, faster transitions in the microsecond timescale have not yet been observed. In this study, we employed time-resolved, temperature-jump small angle X-ray scattering to monitor structural rearrangements in an HIV-1 Env ectodomain construct with microsecond precision. We detected a transition correlated with Env opening that occurs in the hundreds of microseconds range and another more rapid transition that preceded this opening. Model fitting indicated that the early rapid transition involved an order-to-disorder transition in the trimer apex loop contacts, suggesting that conventional conformation-locking design strategies that target the allosteric machinery may be ineffective in preventing this movement. Utilizing this information, we engineered an envelope that locks the apex loop contacts to the adjacent protomer. This modification resulted in significant angle-of-approach shifts in the interaction of a neutralizing antibody. Our findings imply that blocking the intermediate state could be crucial for inducing antibodies with the appropriate bound state orientation through vaccination.
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Affiliation(s)
- Ashley L Bennett
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - R J Edwards
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Irina Kosheleva
- BioCARS, Center for Advanced Radiation Sources, The University of Chicago, 9700 South Cass Ave, Bld 434B, Lemont, IL 60439, USA
| | - Carrie Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Yishak Bililign
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Ashliegh Williams
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Katayoun Manosouri
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Rory Henderson
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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3
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Rao PG, Lambert GS, Upadhyay C. Broadly Neutralizing Antibody Epitopes on HIV-1 Particles are exposed after Virus Interaction with Host Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524996. [PMID: 36711466 PMCID: PMC9882293 DOI: 10.1101/2023.01.20.524996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The envelope glycoproteins (Env) on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAb) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes including V2i, gp120-g41 interface, and gp41-MPER are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where virus-mAb mix was pre-incubated/not pre-incubated for one hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are the ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use.
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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: 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: 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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5
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Mostashari-Rad T, Claes S, Schols D, Shirvani P, Fassihi A. New 2-alkylthio-1-benzylimidazole-5-carboxylic acid derivatives targeting gp41: design, synthesis and in vitro anti-HIV activity evaluation. Curr HIV Res 2022; 20:CHR-EPUB-124859. [PMID: 35770403 DOI: 10.2174/1570162x20666220628154901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/05/2022] [Accepted: 05/05/2022] [Indexed: 11/22/2022]
Abstract
Background Although current available medications have increased the quality of life in HIV-infected patients, there are still some shortcomings in HIV treatment arising from viral resistance, drug side effects and high cost of medication. Therefore, there is an urgent need for some suitable HIV inhibitors with different mechanisms of action. Gp41, located on the HIV cell surface, plays an important role in the fusion of viral and host cell membranes. With the same structure in different HIV strains, gp41 seems to be a promising target for developing novel HIV fusion inhibitors. Objective Based on the essential structural elements of gp41 inhibitors, two series of compounds were prepared and their inhibitory effect on HIV cell growth was investigated. Compared to the known small-molecule gp41 inhibitors, 2-Alkylthio-1-benzylimidazole-5-carboxylic acid (series I) and (E)-4-{[5-(((1-benzyl-1H-1,2,3-triazol-4-yl)methoxyimino)methyl)-2-(alkylthio)-1H-imidazol-1-yl]methyl}benzoic acid derivatives (series II) had more flexible skeleton with extra moieties interacting with the gp41 key residues. Method In silico drug design approaches including molecular docking and molecular dynamics simulations were employed to design these novel compounds prior to preparation. The designed compounds exhibited proper chemical interactions and stable complexes with gp41. Then, the selected candidates were efficiently synthesized, and their anti-HIV-1 and anti-HIV-2 activities, as well as their cellular cytotoxicity in MT-4 cells were determined. Results None of the compounds belonging to the series I were active against HIV-1 and HIV-2 replication in cell cultures, and most of the compounds in series II exhibited significant cytotoxicity against MT-4 cells in low micro molar concentrations. Conclusion The smaller molecular structures of the compounds in series I might be responsible for their poor anti-HIV effects. The high toxicity of the series II compounds on the host cell makes it impossible to assess their anti-HIV activities.
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Affiliation(s)
- Tahereh Mostashari-Rad
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sandra Claes
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Dominique Schols
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Pouria Shirvani
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Afshin Fassihi
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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6
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Schapiro HM, Khasnis MD, Ahn K, Karagiaridi A, Hayden S, Cilento ME, Root MJ. Regulation of epitope exposure in the gp41 membrane-proximal external region through interactions at the apex of HIV-1 Env. PLoS Pathog 2022; 18:e1010531. [PMID: 35584191 PMCID: PMC9154124 DOI: 10.1371/journal.ppat.1010531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 05/31/2022] [Accepted: 04/18/2022] [Indexed: 11/19/2022] Open
Abstract
Glycoprotein Env of human immunodeficiency virus type 1 (HIV-1) mediates viral entry through membrane fusion. Composed of gp120 and gp41 subunits arranged as a trimer-of-heterodimers, Env adopts a metastable, highly dynamic conformation on the virion surface. This structural plasticity limits the temporospatial exposure of many highly conserved, neutralizing epitopes, contributing to the difficulty in developing effective HIV-1 vaccines. Here, we employed antibody neutralization of HIV-1 infectivity to investigate how inter- and intra-gp120 interactions mediated by variable loops V1/V2 and V3 at the Env apex regulate accessibility of the gp41 membrane-proximal external region (MPER) at the Env base. Swapping the V3 loop from EnvSF162 into the EnvHXB2 background shifted MPER exposure from the prefusogenic state to a functional intermediate conformation that was distinct from the prehairpin-intermediate state sensitive to gp41-targeted fusion inhibitors. The V3-loop swap had a profound impact on global protein dynamics, biasing the equilibrium to a closed conformation resistant to most anti-gp120 antibodies, stabilizing the protein to both cold- and soluble CD4-induced Env inactivation, and increasing the CD4 requirements for viral entry. Further dissection of the EnvHXB2 V3 loop revealed that residue 306 uniquely modulated epitope exposure and trimer stability. The R306S substitution substantially decreased sensitivity to antibodies targeting the gp41 MPER and, surprisingly, the gp120 V3-loop crown (residues 312–315), but had only modest effects on exposure of intervening gp120 epitopes. Furthermore, the point mutation reduced soluble CD4-induced inactivation, but had no impact on cold inactivation. The residue appeared to exert its effects by electrostatically modifying the strength of intra-subunit interactions between the V1/V2 and V3 loops. The distinct patterns of neutralization and stability pointed to a novel prefusogenic Env conformation along the receptor activation pathway and suggested that apical Env-regulation of gp41 MPER exposure can be decoupled from much of the dynamics of gp120 subunits. Surface glycoprotein Env is the main target for neutralizing antibodies elicited by HIV-1 vaccines. Env spontaneously fluctuates among different structures, limiting exposure of many attractive antibody-binding epitopes and, thereby, confounding vaccine development. To characterize these fluctuations, we examined how exposure of the MPER epitope found at the base of Env is regulated by interactions of the V3 loop located in the apex. Starting with an extremely flexible Env with a readily-exposed MPER, we identified two alterations that substantially restricted antibody access to the epitope. The first, a wholesale swap of V3 loops between HIV-1 strains, energetically stabilized Env in a closed structure that restricted access to antibodies throughout the protein. The second, a point mutation that altered V3-loop charge, specifically destabilized the MPER-exposed conformation but had minimal impact on antibody access to Env regions in between the apex and base. The results indicate that MPER exposure is not explicitly tied to the dynamics of Env regions between the apex and base and suggest a new structural fluctuation during Env activation.
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Affiliation(s)
- Hannah M. Schapiro
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Mukta D. Khasnis
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Koree Ahn
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Alexandra Karagiaridi
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Stephanie Hayden
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Maria E. Cilento
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Michael J. Root
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
- * E-mail:
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7
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Mu Z, Wiehe K, Saunders KO, Henderson R, Cain DW, Parks R, Martik D, Mansouri K, Edwards RJ, Newman A, Lu X, Xia SM, Eaton A, Bonsignori M, Montefiori D, Han Q, Venkatayogi S, Evangelous T, Wang Y, Rountree W, Korber B, Wagh K, Tam Y, Barbosa C, Alam SM, Williams WB, Tian M, Alt FW, Pardi N, Weissman D, Haynes BF. mRNA-encoded HIV-1 Env trimer ferritin nanoparticles induce monoclonal antibodies that neutralize heterologous HIV-1 isolates in mice. Cell Rep 2022; 38:110514. [PMID: 35294883 PMCID: PMC8922439 DOI: 10.1016/j.celrep.2022.110514] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 01/09/2022] [Accepted: 02/17/2022] [Indexed: 12/14/2022] Open
Abstract
The success of nucleoside-modified mRNAs in lipid nanoparticles (mRNA-LNP) as COVID-19 vaccines heralded a new era of vaccine development. For HIV-1, multivalent envelope (Env) trimer protein nanoparticles are superior immunogens compared with trimers alone for priming of broadly neutralizing antibody (bnAb) B cell lineages. The successful expression of complex multivalent nanoparticle immunogens with mRNAs has not been demonstrated. Here, we show that mRNAs can encode antigenic Env trimers on ferritin nanoparticles that initiate bnAb precursor B cell expansion and induce serum autologous tier 2 neutralizing activity in bnAb precursor VH + VL knock-in mice. Next-generation sequencing demonstrates acquisition of critical mutations, and monoclonal antibodies that neutralize heterologous HIV-1 isolates are isolated. Thus, mRNA-LNP can encode complex immunogens and may be of use in design of germline-targeting and sequential boosting immunogens for HIV-1 vaccine development.
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Affiliation(s)
- Zekun Mu
- Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kevin O Saunders
- Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Rory Henderson
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Derek W Cain
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Diana Martik
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Katayoun Mansouri
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Robert J Edwards
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Amanda Newman
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Xiaozhi Lu
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Shi-Mao Xia
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Amanda Eaton
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mattia Bonsignori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - David Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Qifeng Han
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Sravani Venkatayogi
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Tyler Evangelous
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yunfei Wang
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Wes Rountree
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Bette Korber
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Kshitij Wagh
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | | | | - S Munir Alam
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Wilton B Williams
- Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ming Tian
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Frederick W Alt
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Norbert Pardi
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Drew Weissman
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Barton F Haynes
- Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.
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8
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Mangala Prasad V, Leaman DP, Lovendahl KN, Croft JT, Benhaim MA, Hodge EA, Zwick MB, Lee KK. Cryo-ET of Env on intact HIV virions reveals structural variation and positioning on the Gag lattice. Cell 2022; 185:641-653.e17. [PMID: 35123651 PMCID: PMC9000915 DOI: 10.1016/j.cell.2022.01.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/19/2021] [Accepted: 01/18/2022] [Indexed: 01/11/2023]
Abstract
HIV-1 Env mediates viral entry into host cells and is the sole target for neutralizing antibodies. However, Env structure and organization in its native virion context has eluded detailed characterization. Here, we used cryo-electron tomography to analyze Env in mature and immature HIV-1 particles. Immature particles showed distinct Env positioning relative to the underlying Gag lattice, providing insights into long-standing questions about Env incorporation. A 9.1-Å sub-tomogram-averaged reconstruction of virion-bound Env in conjunction with structural mass spectrometry revealed unexpected features, including a variable central core of the gp41 subunit, heterogeneous glycosylation between protomers, and a flexible stalk that allows Env tilting and variable exposure of neutralizing epitopes. Together, our results provide an integrative understanding of HIV assembly and structural variation in Env antigen presentation.
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Affiliation(s)
- Vidya Mangala Prasad
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Daniel P Leaman
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Klaus N Lovendahl
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Jacob T Croft
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Mark A Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Edgar A Hodge
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Michael B Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA; Biological Physics, Structure and Design Graduate Program, University of Washington, Seattle, WA 98195, USA; Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
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9
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Sreeram S, Sathishkumar R, Amritha PS. Targeting the ENV spike protein of HIV with naturally occurring compounds: an in-silico study for drug designing. ADVANCES IN TRADITIONAL MEDICINE 2021. [PMCID: PMC8506072 DOI: 10.1007/s13596-021-00617-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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HERRERA C, HARMAN S, ALDON Y, ROGERS P, ARMANASCO N, ZIPRIN P, STIEH D, NUTTALL J, SHATTOCK RJ. The entry inhibitor DS003 (BMS-599793): a BMS-806 analogue, provides superior activity as a pre-exposure prophylaxis candidate. AIDS 2021; 35:1907-1917. [PMID: 34101626 PMCID: PMC8416713 DOI: 10.1097/qad.0000000000002974] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Small molecule inhibitors able to bind to gp120 and prevent CD4+-induced HIV-1 envelope conformational change provide an important class of inhibitors. Currently, only Fostemsavir is approved for HAART, which makes this class of inhibitors attractive candidates for prevention. We assessed the activity of DS003 (BMS-599793), an analogue of BMS-378806, in different mucosal tissues and elucidated its mechanism of action. DESIGN Preclinical analysis was performed with human mucosal tissue models as surrogates of in-vivo activity. METHODS Antiviral efficacy of DS003 was assessed in mucosal tissue explants (ecto-cervical, penile and colorectal) and in trans-infection models (co-cultures of dendritic or mucosal migratory cells with CD4+ T cells) with several dosing times (2, 24 h and sustained) and in combination with a fusion inhibitor. Binding of DS003 to gp120 was assessed by flow cytometry and bio-layer interferometry and further probed in competitive studies using soluble CD4+ (sCD4+) and an anti-CD4+ induced antibody, 17b. RESULTS In all models, the inhibitory activity of DS003 was increased with longer periods of exposure and by combination with a fusion inhibitor. Pre-exposure to sCD4+ impeded DS003 binding to viral envelope. In contrast, DS003 did not impact subsequent binding of sCD4+. Furthermore, sCD4+-induced epitope exposure as assessed by 17b binding was significantly reduced in the presence of DS003. CONCLUSION DS003 inhibits HIV-1 infection by binding to or near the CD4+ binding site of gp120, preventing CD4+-induced conformational change essential for viral fusion. These data highlight the potential of DS003 for development as a pre-exposure prophylaxis candidate.
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Affiliation(s)
- Carolina HERRERA
- Centre for Infection, Division of Cellular & Molecular Medicine, St George’s University of London, UK. Current address: Section of Infectious Diseases, Faculty of Medicine, St Mary’s Campus, Imperial College, UK
| | - Sarah HARMAN
- Centre for Infection, Division of Cellular & Molecular Medicine, St George’s University of London, UK. Current address: London School of Hygiene and Tropical Medicine, London, UK
| | - Yoann ALDON
- Section of Infectious Diseases, Faculty of Medicine, St Mary’s Campus, Imperial College, UK. Current address: Amsterdam UMC, Netherlands
| | - Paul ROGERS
- Centre for Infection, Division of Cellular & Molecular Medicine, St George’s University of London, UK. Current address: Section of Infectious Diseases, Faculty of Medicine, St Mary’s Campus, Imperial College, UK
| | - Naomi ARMANASCO
- Centre for Infection, Division of Cellular & Molecular Medicine, St George’s University of London, UK. Current address: Section of Infectious Diseases, Faculty of Medicine, St Mary’s Campus, Imperial College, UK
| | - Paul ZIPRIN
- Department of Surgery and Cancer, St Mary’s Hospital, Imperial College London, UK
| | - Daniel STIEH
- Centre for Infection, Division of Cellular & Molecular Medicine, St George’s University of London, UK. Current address: Janssen Vaccines & Prevention B.V. Leiden, Netherlands
| | - Jeremy NUTTALL
- International Partnership for Microbicides, Silver Spring, MD, USA
| | - Robin J. SHATTOCK
- Centre for Infection, Division of Cellular & Molecular Medicine, St George’s University of London, UK. Current address: Section of Infectious Diseases, Faculty of Medicine, St Mary’s Campus, Imperial College, UK
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11
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HIV-1 entry: Duels between Env and host antiviral transmembrane proteins on the surface of virus particles. Curr Opin Virol 2021; 50:59-68. [PMID: 34390925 DOI: 10.1016/j.coviro.2021.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 12/18/2022]
Abstract
Human Immunodeficiency Virus type-1 (HIV-1) is the causative agent of AIDS. Its entry step is mediated by the envelope glycoprotein (Env). During the entry process, Env vastly changes its conformation. While non-liganded Env tends to have a closed structure, receptor-binding of Env opens its conformation, which leads to virus-cell membrane fusion. Single-molecule fluorescence resonance energy transfer (smFRET) imaging allows observation of these conformational changes on the virion surface. Nascent HIV-1 particles incorporate multiple host transmembrane proteins, some of which inhibit the entry process. The Env structure or its dynamics may determine the effectiveness of these antiviral mechanisms. Here, we review recent findings about the Env conformation changes on virus particles and inhibition of Env activities by virion-incorporated host transmembrane proteins.
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12
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Mu Z, Wiehe K, Saunders KO, Henderson R, Cain DW, Parks R, Martik D, Mansouri K, Edwards RJ, Newman A, Lu X, Xia SM, Bonsignori M, Montefiori D, Han Q, Venkatayogi S, Evangelous T, Wang Y, Rountree W, Tam Y, Barbosa C, Alam SM, Williams WB, Pardi N, Weissman D, Haynes BF. Ability of nucleoside-modified mRNA to encode HIV-1 envelope trimer nanoparticles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.08.09.455714. [PMID: 34401876 PMCID: PMC8366792 DOI: 10.1101/2021.08.09.455714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The success of nucleoside-modified mRNAs in lipid nanoparticles (mRNA-LNP) as COVID-19 vaccines heralded a new era of vaccine development. For HIV-1, multivalent envelope (Env) trimer protein nanoparticles are superior immunogens compared to trimers alone for priming of broadly neutralizing antibody (bnAb) B cell lineages. The successful expression of complex multivalent nanoparticle immunogens with mRNAs has not been demonstrated. Here we show that mRNAs can encode antigenic Env trimers on ferritin nanoparticles that initiate bnAb precursor B cell expansion and induce serum autologous tier 2 neutralizing activity in bnAb precursor VH + VL knock-in mice. Next generation sequencing demonstrated acquisition of critical mutations, and monoclonal antibodies that neutralized heterologous HIV-1 isolates were isolated. Thus, mRNA-LNP can encode complex immunogens and are of use in design of germline-targeting and sequential boosting immunogens for HIV-1 vaccine development.
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Affiliation(s)
- Zekun Mu
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kevin O. Saunders
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Rory Henderson
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Derek W. Cain
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Diana Martik
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Katayoun Mansouri
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Robert J. Edwards
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Amanda Newman
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Xiaozhi Lu
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Shi-Mao Xia
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mattia Bonsignori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
- Current Address: Translational Immunobiology Unit, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, US
| | - David Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Qifeng Han
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Sravani Venkatayogi
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Tyler Evangelous
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yunfei Wang
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Wes Rountree
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | | | | | - S. Munir Alam
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Wilton B. Williams
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Norbert Pardi
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Drew Weissman
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Barton F. Haynes
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
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13
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Chua JV, Davis C, Husson JS, Nelson A, Prado I, Flinko R, Lam KWJ, Mutumbi L, Mayer BT, Dong D, Fulp W, Mahoney C, Gerber M, Gottardo R, Gilliam BL, Greene K, Gao H, Yates N, Ferrari G, Tomaras G, Montefiori D, Schwartz JA, Fouts T, DeVico AL, Lewis GK, Gallo RC, Sajadi MM. Safety and immunogenicity of an HIV-1 gp120-CD4 chimeric subunit vaccine in a phase 1a randomized controlled trial. Vaccine 2021; 39:3879-3891. [PMID: 34099328 PMCID: PMC8224181 DOI: 10.1016/j.vaccine.2021.05.090] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/14/2021] [Accepted: 05/23/2021] [Indexed: 01/14/2023]
Abstract
A major challenge for HIV vaccine development is to raise anti-envelope antibodies capable of recognizing and neutralizing diverse strains of HIV-1. Accordingly, a full length single chain (FLSC) of gp120-CD4 chimeric vaccine construct was designed to present a highly conserved CD4-induced (CD4i) HIV-1 envelope structure that elicits cross-reactive anti-envelope humoral responses and protective immunity in animal models of HIV infection. IHV01 is the FLSC formulated in aluminum phosphate adjuvant. We enrolled 65 healthy adult volunteers in this first-in-human phase 1a randomized, double-blind, placebo-controlled study with three dose-escalating cohorts (75 µg, 150 µg, and 300 µg doses). Intramuscular injections were given on weeks 0, 4, 8, and 24. Participants were followed for an additional 24 weeks after the last immunization. The overall incidence of adverse events (AEs) was not significantly different between vaccinees and controls. The majority (89%) of vaccine-related AE were mild. The most common vaccine-related adverse event was injection site pain. There were no vaccine-related serious AE, discontinuation due to AE, intercurrent HIV infection, or significant decreases in CD4 count. By the final vaccination, all vaccine recipients developed antibodies against IHV01 and demonstrated anti-CD4i epitope antibodies. The elicited antibodies reacted with CD4 non-liganded Env antigens from diverse HIV-1 strains. Antibody-dependent cell-mediated cytotoxicity against heterologous infected cells or gp120 bound to CD4+ cells was evident in all cohorts as were anti-gp120 T-cell responses. IHV01 vaccine was safe, well tolerated, and immunogenic at all doses tested. The vaccine raised broadly reactive humoral responses against conserved CD4i epitopes on gp120 that mediates antiviral functions.
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Affiliation(s)
- Joel V Chua
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Charles Davis
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jennifer S Husson
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amy Nelson
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ilia Prado
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robin Flinko
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ka Wing J Lam
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Lydiah Mutumbi
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bryan T Mayer
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Dan Dong
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - William Fulp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Celia Mahoney
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Monica Gerber
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Raphael Gottardo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Bruce L Gilliam
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kelli Greene
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Hongmei Gao
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Nicole Yates
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Guido Ferrari
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Georgia Tomaras
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - David Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | | | - Timothy Fouts
- Advanced BioScience Laboratories, Rockville, MD, USA
| | - Anthony L DeVico
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA; Global Virus Network, Baltimore, MD, USA
| | - George K Lewis
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA; Global Virus Network, Baltimore, MD, USA
| | - Robert C Gallo
- Global Virus Network, Baltimore, MD, USA; Division of Basic Science, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mohammad M Sajadi
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA; Intralytix, Columbia, MD, USA.
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Duerr R, Crosse KM, Valero-Jimenez AM, Dittmann M. SARS-CoV-2 Portrayed against HIV: Contrary Viral Strategies in Similar Disguise. Microorganisms 2021; 9:1389. [PMID: 34198973 PMCID: PMC8307803 DOI: 10.3390/microorganisms9071389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/06/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
SARS-CoV-2 and HIV are zoonotic viruses that rapidly reached pandemic scale, causing global losses and fear. The COVID-19 and AIDS pandemics ignited massive efforts worldwide to develop antiviral strategies and characterize viral architectures, biological and immunological properties, and clinical outcomes. Although both viruses have a comparable appearance as enveloped viruses with positive-stranded RNA and envelope spikes mediating cellular entry, the entry process, downstream biological and immunological pathways, clinical outcomes, and disease courses are strikingly different. This review provides a systemic comparison of both viruses' structural and functional characteristics, delineating their distinct strategies for efficient spread.
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Affiliation(s)
- Ralf Duerr
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA; (K.M.C.); (A.M.V.-J.); (M.D.)
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15
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Bennett AL, Henderson R. HIV-1 Envelope Conformation, Allostery, and Dynamics. Viruses 2021; 13:852. [PMID: 34067073 PMCID: PMC8150877 DOI: 10.3390/v13050852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) mediates host cell fusion and is the primary target for HIV-1 vaccine design. The Env undergoes a series of functionally important conformational rearrangements upon engagement of its host cell receptor, CD4. As the sole target for broadly neutralizing antibodies, our understanding of these transitions plays a critical role in vaccine immunogen design. Here, we review available experimental data interrogating the HIV-1 Env conformation and detail computational efforts aimed at delineating the series of conformational changes connecting these rearrangements. These studies have provided a structural mapping of prefusion closed, open, and transition intermediate structures, the allosteric elements controlling rearrangements, and state-to-state transition dynamics. The combination of these investigations and innovations in molecular modeling set the stage for advanced studies examining rearrangements at greater spatial and temporal resolution.
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Affiliation(s)
| | - Rory Henderson
- Duke Human Vaccine Institute, Durham, NC 27710, USA;
- Department of Medicine, Duke University, Durham, NC 27710, USA
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16
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Tamiz N, Mostashari-Rad T, Najafipour A, Claes S, Schols D, Fassihi A. Synthesis, Molecular Docking and Molecular Dynamics Simulation of 2- Thioxothiazolidin-4-One Derivatives against Gp41. Curr HIV Res 2021; 19:47-60. [PMID: 32885756 DOI: 10.2174/1570162x18666200903172127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/10/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Gp41 and its conserved hydrophobic groove on the N-terminal heptad repeat region are attractive targets in the design of HIV-1 entry inhibitors. Linearly extended molecules have shown potent anti-HIV-1 activity for their effective interactions with the gp41 binding pocket. Rhodanine ring attached to substituted pyrrole or furan rings has been proved a preferred moiety to be inserted inside the molecular structure of the gp41 inhibitors. OBJECTIVES Based on the previous findings we are going to describe some rhodanine derivatives in which a substituted imidazole ring is introduced in place of the pyrrole or furan rings. The compounds' flexibility is increased by inserting methylene groups inside the main scaffold. METHODS Molecular docking and molecular dynamics simulations approaches were exploited to investigate the chemical interactions and the stability of the designed ligands-gp41 complex. All compounds were synthesized and their chemical structures were elucidated by 1HNMR, 13CNMR, FTIR and Mass spectroscopy. Biological activities of the compounds against HIV-1 and HIV-2 and their cellular toxicities against the T-lymphocyte (MT-4) cell line were determined. RESULTS All the designed compounds showed proper and stable chemical interactions with gp41 according to the in silico studies. The results of the biological tests proved none of the compounds active against HIV-1 replication in cell cultures. CONCLUSION Since all the studied compounds were potently toxic for the host cell; it was therefore not possible to assess their anti-HIV activities.
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Affiliation(s)
- Nahid Tamiz
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Tahereh Mostashari-Rad
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Aylar Najafipour
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sandra Claes
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Dominique Schols
- Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven, Belgium
| | - Afshin Fassihi
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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17
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Wang L, Xiang Y. Spike Glycoprotein-Mediated Entry of SARS Coronaviruses. Viruses 2020; 12:E1289. [PMID: 33187074 PMCID: PMC7696831 DOI: 10.3390/v12111289] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/07/2020] [Accepted: 11/08/2020] [Indexed: 12/12/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 are enveloped, positive-sense, single-stranded RNA viruses and causes of epidemic diseases that have resulted in public health emergencies worldwide. Angiotensin-converting enzyme 2 (ACE2) is the receptor that allows the entry of these two viruses into host cells, a key step in the life cycle of the pathogens. The characterization of the interactions of ACE2 with the viral spike glycoproteins and structural studies of the ACE2-binding-induced conformational changes in the viral spike glycoproteins have furthered our understanding of the entry processes of these two viruses, and these studies provide useful information that will facilitate the development of antiviral agents and vaccines to control the diseases.
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Affiliation(s)
| | - Ye Xiang
- Center for Infectious Disease Research, Beijing Frontier Research Center for Biological Structure & Beijing Advanced Innovation Center for Structural Biology, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China;
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Ventura JD. Human Immunodeficiency Virus 1 (HIV-1): Viral Latency, the Reservoir, and the Cure. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2020; 93:549-560. [PMID: 33005119 PMCID: PMC7513431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
An estimated 37 million people globally suffer from Human Immunodeficiency Virus-1 (HIV-1) infection with 1.7 million newly acquired infections occurring on average each year. Although crucial advances in combined antiretroviral therapy (ART) over the last two decades have transformed an HIV-1 diagnosis into a tolerable and controlled condition, enabling over 20 million people living with HIV-1 to enjoy healthy and productive lives, no cure or vaccine yet exists. Developing a successful cure strategy will require a firm understanding of how viral latency is established and how a persistent and long-lived latent is generated. The latent reservoir remains the primary obstacle for cure development and most putative cure strategies proposed fundamentally address its eradication or permanent suppression.
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Affiliation(s)
- John D. Ventura
- To whom all correspondence should be addressed:
Dr. John D. Ventura, . ORCID iD:
https://orcid.org/0000-0002-4373-3242.
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Tolbert WD, Sherburn R, Gohain N, Ding S, Flinko R, Orlandi C, Ray K, Finzi A, Lewis GK, Pazgier M. Defining rules governing recognition and Fc-mediated effector functions to the HIV-1 co-receptor binding site. BMC Biol 2020; 18:91. [PMID: 32693837 PMCID: PMC7374964 DOI: 10.1186/s12915-020-00819-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 06/22/2020] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The binding of HIV-1 Envelope glycoproteins (Env) to host receptor CD4 exposes vulnerable conserved epitopes within the co-receptor binding site (CoRBS) which are required for the engagement of either CCR5 or CXCR4 co-receptor to allow HIV-1 entry. Antibodies against this region have been implicated in the protection against HIV acquisition in non-human primate (NHP) challenge studies and found to act synergistically with antibodies of other specificities to deliver effective Fc-mediated effector function against HIV-1-infected cells. Here, we describe the structure and function of N12-i2, an antibody isolated from an HIV-1-infected individual, and show how the unique structural features of this antibody allow for its effective Env recognition and Fc-mediated effector function. RESULTS N12-i2 binds within the CoRBS utilizing two adjacent sulfo-tyrosines (TYS) for binding, one of which binds to a previously unknown TYS binding pocket formed by gp120 residues of high sequence conservation among HIV-1 strains. Structural alignment with gp120 in complex with the co-receptor CCR5 indicates that the new pocket corresponds to TYS at position 15 of CCR5. In addition, structure-function analysis of N12-i2 and other CoRBS-specific antibodies indicates a link between modes of antibody binding within the CoRBS and Fc-mediated effector activities. The efficiency of antibody-dependent cellular cytotoxicity (ADCC) correlated with both the level of antibody binding and the mode of antibody attachment to the epitope region, specifically with the way the Fc region was oriented relative to the target cell surface. Antibodies with poor Fc access mediated the poorest ADCC whereas those with their Fc region readily accessible for interaction with effector cells mediated the most potent ADCC. CONCLUSION Our data identify a previously unknown binding site for TYS within the assembled CoRBS of the HIV-1 virus. In addition, our combined structural-modeling-functional analyses provide new insights into mechanisms of Fc-effector function of antibodies against HIV-1, in particular, how antibody binding to Env antigen affects the efficiency of ADCC response.
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Affiliation(s)
- William D Tolbert
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Rebekah Sherburn
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Neelakshi Gohain
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Shilei Ding
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Robin Flinko
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Chiara Orlandi
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Krishanu Ray
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - George K Lewis
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Marzena Pazgier
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA.
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA.
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20
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Structure, interactions and membrane topology of HIV gp41 ectodomain sequences. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183274. [DOI: 10.1016/j.bbamem.2020.183274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 11/21/2022]
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21
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Abstract
Bispecific therapeutics target two distinct antigens simultaneously and provide novel functionalities that are not attainable with single monospecific molecules or combinations of them. The unique potential of bispecific therapeutics is driving extensive efforts to discover synergistic dual targets, design molecular formats to integrate bispecific elements, and accelerate successful clinical translation. In particular, the past decade has witnessed a boom in the design and development of bispecific antibody formats with more than 100 collections to date. Despite the remarkable progress that has been made to expand the number of formats, qualitative fine-tuning of bispecific formats is needed to achieve optimal dual-target engagement based on understanding of the spatiotemporal interdependence of the two physically linked binding specificities and the complex target biology associated with bispecific approaches. This review provides insights into the design parameters - including affinity, valency, and geometry - that need to be considered at an early stage of development in order to take the best advantage of bispecific therapeutics.
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Affiliation(s)
- Sung In Lim
- Department of Chemical Engineering, Pukyong National University, Yongso-ro 45, Nam-gu, Busan, South Korea.
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22
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Rantalainen K, Berndsen ZT, Antanasijevic A, Schiffner T, Zhang X, Lee WH, Torres JL, Zhang L, Irimia A, Copps J, Zhou KH, Kwon YD, Law WH, Schramm CA, Verardi R, Krebs SJ, Kwong PD, Doria-Rose NA, Wilson IA, Zwick MB, Yates JR, Schief WR, Ward AB. HIV-1 Envelope and MPER Antibody Structures in Lipid Assemblies. Cell Rep 2020; 31:107583. [PMID: 32348769 PMCID: PMC7196886 DOI: 10.1016/j.celrep.2020.107583] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/05/2020] [Accepted: 04/07/2020] [Indexed: 11/25/2022] Open
Abstract
Structural and functional studies of HIV envelope glycoprotein (Env) as a transmembrane protein have long been complicated by challenges associated with inherent flexibility of the molecule and the membrane-embedded hydrophobic regions. Here, we present approaches for incorporating full-length, wild-type HIV-1 Env, as well as C-terminally truncated and stabilized versions, into lipid assemblies, providing a modular platform for Env structural studies by single particle electron microscopy. We reconstitute a full-length Env clone into a nanodisc, complex it with a membrane-proximal external region (MPER) targeting antibody 10E8, and structurally define the full quaternary epitope of 10E8 consisting of lipid, MPER, and ectodomain contacts. By aligning this and other Env-MPER antibody complex reconstructions with the lipid bilayer, we observe evidence of Env tilting as part of the neutralization mechanism for MPER-targeting antibodies. We also adapt the platform toward vaccine design purposes by introducing stabilizing mutations that allow purification of unliganded Env with a peptidisc scaffold.
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Affiliation(s)
- Kimmo Rantalainen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Zachary T Berndsen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Aleksandar Antanasijevic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Torben Schiffner
- Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xi Zhang
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jonathan L Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lei Zhang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Adriana Irimia
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffrey Copps
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kenneth H Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Young D Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - William H Law
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Chaim A Schramm
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Shelly J Krebs
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Michael B Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - William R Schief
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02129, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA.
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23
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Henderson R, Lu M, Zhou Y, Mu Z, Parks R, Han Q, Hsu AL, Carter E, Blanchard SC, Edwards RJ, Wiehe K, Saunders KO, Borgnia MJ, Bartesaghi A, Mothes W, Haynes BF, Acharya P, Munir Alam S. Disruption of the HIV-1 Envelope allosteric network blocks CD4-induced rearrangements. Nat Commun 2020; 11:520. [PMID: 31980614 PMCID: PMC6981184 DOI: 10.1038/s41467-019-14196-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/18/2019] [Indexed: 11/24/2022] Open
Abstract
The trimeric HIV-1 Envelope protein (Env) mediates viral-host cell fusion via a network of conformational transitions, with allosteric elements in each protomer orchestrating host receptor-induced exposure of the co-receptor binding site and fusion elements. To understand the molecular details of this allostery, here, we introduce Env mutations aimed to prevent CD4-induced rearrangements in the HIV-1 BG505 Env trimer. Binding analysis and single-molecule Förster Resonance Energy Transfer confirm that these mutations prevent CD4-induced transitions of the HIV-1 Env. Structural analysis by single-particle cryo-electron microscopy performed on the BG505 SOSIP mutant Env proteins shows rearrangements in the gp120 topological layer contacts with gp41. Displacement of a conserved tryptophan (W571) from its typical pocket in these Env mutants renders the Env insensitive to CD4 binding. These results reveal the critical function of W571 as a conformational switch in Env allostery and receptor-mediated viral entry and provide insights on Env conformation that are relevant for vaccine design.
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Affiliation(s)
- Rory Henderson
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA.
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA.
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, NC, 27708, USA
| | - Zekun Mu
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Qifeng Han
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Allen L Hsu
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Elizabeth Carter
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10021, USA
- St. Jude Children's Research Hospital, Department of Structural Biology, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
| | - R J Edwards
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kevin Wiehe
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Surgery, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Mario J Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Alberto Bartesaghi
- Department of Computer Science, Duke University, Durham, NC, 27708, USA
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Barton F Haynes
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Surgery, Duke University School of Medicine, Durham, NC, 27710, USA.
| | - S Munir Alam
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA.
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Pathology, Duke University School of Medicine, Durham, NC, 27710, USA.
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24
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Abstract
Monoclonal based therapeutics have always been looked at as a futuristic natural way we could take care of pathogens and many diseases. However, in order to develop, establish and realize monoclonal based therapy we need to understand how the immune system contains or kill pathogens. Antibody complexes serve the means to decode this black box. We have discussed examples of antibody complexes both at biochemical and structural levels to understand and appreciate how discoveries in the field of antibody complexes have started to decoded mechanism of viral invasion and create potential vaccine targets against many pathogens. Antibody complexes have made advancement in our knowledge about the molecular interaction between antibody and antigen. It has also led to identification of potent protective monoclonal antibodies. Further use of selective combination of monoclonal antibodies have provided improved protection against deadly diseases. The administration of newly designed and improved immunogen has been used as potential vaccine. Therefore, antibody complexes are important tools to develop new vaccine targets and design an improved combination of monoclonal antibodies for passive immunization or protection with very little or no side effects.
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Affiliation(s)
- Reetesh Raj Akhouri
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | | | - Gunnar Wilken
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Ulf Skoglund
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
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25
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Li N, Li Z, Fu Y, Cao S. Cryo-EM Studies of Virus-Antibody Immune Complexes. Virol Sin 2020; 35:1-13. [PMID: 31916022 PMCID: PMC7035235 DOI: 10.1007/s12250-019-00190-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/25/2019] [Indexed: 01/25/2023] Open
Abstract
Antibodies play critical roles in neutralizing viral infections and are increasingly used as therapeutic drugs and diagnostic tools. Structural studies on virus-antibody immune complexes are important for better understanding the molecular mechanisms of antibody-mediated neutralization and also provide valuable information for structure-based vaccine design. Cryo-electron microscopy (cryo-EM) has recently matured as a powerful structural technique for studying bio-macromolecular complexes. When combined with X-ray crystallography, cryo-EM provides a routine approach for structurally characterizing the immune complexes formed between icosahedral viruses and their antibodies. In this review, recent advances in the structural understanding of virus-antibody interactions are outlined for whole virions with icosahedral T = pseudo 3 (picornaviruses) and T = 3 (flaviviruses) architectures, focusing on the dynamic nature of viral shells in different functional states. Glycoprotein complexes from pleomorphic enveloped viruses are also discussed as immune complex antigens. Improving our understanding of viral epitope structures using virus-based platforms would provide a fundamental road map for future vaccine development.
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Affiliation(s)
- Na Li
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Wuhan, 430071, China.,Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhiqiang Li
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Wuhan, 430071, China.,Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yan Fu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Wuhan, 430071, China.,Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Sheng Cao
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Wuhan, 430071, China. .,Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China.
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26
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Abstract
To better evaluate HIV-1 vaccines and therapeutics, the National Institutes for Food and Drug Control of China developed a panel of HIV-1 pseudoviruses including 462 viral strains derived from China, covering the majority of contemporaneous subtypes and circulating recombinant forms. Compared with the standard pseudovirus panels derived from other countries/regions, the Chinese isolates are more susceptible to neutralization by the sera obtained in China, revealing the strain/subtype specificity. Some of these pseudoviruses have already been used for the evaluation of HIV vaccines and drug candidates in Chinese clinical trials. The pseudoviruses panel is widely shared with interested scientists involved in the research and development of vaccines and antiviral drugs against HIV-1 strains prevalent in China.
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Affiliation(s)
- Jianhui Nie
- Division of HIV/AIDS and Sexually Transmitted Virus Vaccines, National Institutes for Food and Drug Control (NIFDC), Beijing, People's Republic of China
| | - Weijin Huang
- Division of HIV/AIDS and Sexually Transmitted Virus Vaccines, National Institutes for Food and Drug Control (NIFDC), Beijing, People's Republic of China
| | - Qiang Liu
- Division of HIV/AIDS and Sexually Transmitted Virus Vaccines, National Institutes for Food and Drug Control (NIFDC), Beijing, People's Republic of China
| | - Youchun Wang
- Division of HIV/AIDS and Sexually Transmitted Virus Vaccines, National Institutes for Food and Drug Control (NIFDC), Beijing, People's Republic of China
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27
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Lin M, Da LT. Refolding Dynamics of gp41 from Pre-fusion to Pre-hairpin States during HIV-1 Entry. J Chem Inf Model 2019; 60:162-174. [DOI: 10.1021/acs.jcim.9b00746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Mengna Lin
- Key Laboratory of System Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Lin-Tai Da
- Key Laboratory of System Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
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28
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Da LT, Lin M. Opening dynamics of HIV-1 gp120 upon receptor binding is dictated by a key hydrophobic core. Phys Chem Chem Phys 2019; 21:26003-26016. [PMID: 31764922 DOI: 10.1039/c9cp04613e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
HIV-1 entry is mediated firstly by the molecular recognition between the viral glycoprotein gp120 and its receptor CD4 on host T-cells. As a key antigen that can be targeted by neutralizing antibodies, gp120 has been a focus for extensive studies with efforts to understand its structural properties and conformational dynamics upon receptor binding. An atomistic-level revelation of gp120 opening dynamics activated by CD4, however, is still unknown. Here, by constructing a Markov State Model (MSM) based on hundreds of Molecular Dynamics (MD) simulations with an aggregated simulation time of ∼20 microseconds (μs), we identify the key metastable states of gp120 during its opening dynamics upon CD4 binding. The MSM provides a clear dynamic model whereby the identified metastable states coexist and can reach an equilibrium. More importantly, a hydrophobic core flanked by variable loops (V1V2 and V3) and the β20/21 region plays an essential role in triggering the gp120 opening. Any destabilizing effects introduced into the hydrophobic core, therefore, can be expected to promote transition of gp120 to an open state. Moreover, the variable loops demonstrate high flexibilities in fully open gp120. In particular, the V3 region is capable of exploring both closed and open conformations, even with the V1/V2 loops largely adopting an open form. In addition, the bridging sheet formation in gp120 is likely induced by the incoming co-receptor/antibody recognitions, since the V1/V2 structure is highly heterogeneous so that the bridging-sheet formed conformation is not the most populated state. Our studies provide deep insights into the dynamic features of gp120 and its molecular recognitions to the broadly neutralizing antibodies, which guides future attempts to design more effective gp120 immunogens.
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Affiliation(s)
- Lin-Tai Da
- Key Laboratory of System Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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29
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Smith M, Hoffman J, Sojar H, Aalinkeel R, Hsiao CB, Hicar MD. Assessment of Antibody Interference of Enfuvirtide (T20) Function Shows Assay Dependent Variability. Curr HIV Res 2019; 16:404-415. [PMID: 30836922 PMCID: PMC6710457 DOI: 10.2174/1570162x17666190228154850] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 02/06/2023]
Abstract
Background: During HIV infection, fusion of the viral and cellular membranes is dependent on folding of the gp41 trimer into a six-helix bundle. Fusion inhibitors, such as the antiretroviral Enfuvirtide (T20), interfere with the formation of the gp41 six-helix bundle. Recent in vitro studies reveal that the gp41 immunodominant region one targeting antibody 3D6 can block T20 interference, but the clinical and pathophysiologic significance of this finding is unclear. Objective/Method: We have previously characterized a number of antibodies that target conformational epitopes on gp41and herein characterized their ability to interfere with T20 in multiple assays and assess their prevalence in HIV infected subjects. Results: The T20 interference by antibody 3D6 was confirmed in a CHO-HXB2 envelope/ HeLaT4+ cell culture assay. Antibodies that target an immunodominant region one epitope, as well as a gp41 discontinuous epitope, also interfered in this assay, however, not all antibodies that targeted these epitopes showed T20 interference. This response was not due to the direct binding of T20 by the antibodies and could not be replicated utilizing TZM-bl and HL2/3 cells. Notably, serum competition studies on a panel of HIV subjects demonstrate that these conformational targeting antibodies are common in the HIV population. Conclusion: The relatively common nature of antibodies targeting these epitopes, the disparate in vitro results, and lack of reported clinical failures ascribed to such antibodies leads us to conclude that antibody interference of T20 is likely not clinically relevant. However, this warrants continued consideration with the advancement of other fusion inhibitors.
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Affiliation(s)
- Michele Smith
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Jonathon Hoffman
- Department of Pediatrics, Division of Infectious Diseases, University at Buffalo, Buffalo, NY, United States
| | - Hakimuddin Sojar
- Department of Pediatrics, Division of Infectious Diseases, University at Buffalo, Buffalo, NY, United States
| | - Ravikumar Aalinkeel
- Jacobs School of Medicine and Biomedical Sciences, Department of Medicine, Division of Allergy Immunology and Rheumatology, University at Buffalo, Buffalo, NY, United States
| | - Chiu-Bin Hsiao
- Temple University School of Medicine, Pittsburgh, PA, United States.,Allegheny General Hospital, Pittsburgh, PA, United States
| | - Mark Daniel Hicar
- Department of Pediatrics, School of Medicine and Biomedical Sciences, University at Buffalo, NY, United States
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30
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Andrianov AM, Nikolaev GI, Kornoushenko YV, Xu W, Jiang S, Tuzikov AV. In Silico Identification of Novel Aromatic Compounds as Potential HIV-1 Entry Inhibitors Mimicking Cellular Receptor CD4. Viruses 2019; 11:v11080746. [PMID: 31412617 PMCID: PMC6723994 DOI: 10.3390/v11080746] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/13/2022] Open
Abstract
Despite recent progress in the development of novel potent HIV-1 entry/fusion inhibitors, there are currently no licensed antiviral drugs based on inhibiting the critical interactions of the HIV-1 envelope gp120 protein with cellular receptor CD4. In this connection, studies on the design of new small-molecule compounds able to block the gp120-CD4 binding are still of great value. In this work, in silico design of drug-like compounds containing the moieties that make the ligand active towards gp120 was performed within the concept of click chemistry. Complexes of the designed molecules bound to gp120 were then generated by molecular docking and optimized using semiempirical quantum chemical method PM7. Finally, the binding affinity analysis of these ligand/gp120 complexes was performed by molecular dynamic simulations and binding free energy calculations. As a result, five top-ranking compounds that mimic the key interactions of CD4 with gp120 and show the high binding affinity were identified as the most promising CD4-mimemic candidates. Taken together, the data obtained suggest that these compounds may serve as promising scaffolds for the development of novel, highly potent and broad anti-HIV-1 therapeutics.
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Affiliation(s)
- Alexander M Andrianov
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141 Minsk, Belarus.
| | - Grigory I Nikolaev
- United Institute of Informatics Problems, National Academy of Sciences of Belarus, 220012 Minsk, Belarus
| | - Yuri V Kornoushenko
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141 Minsk, Belarus
| | - Wei Xu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, 131 Dong An Road, Fuxing Building, Shanghai 200032, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, 131 Dong An Road, Fuxing Building, Shanghai 200032, China.
| | - Alexander V Tuzikov
- United Institute of Informatics Problems, National Academy of Sciences of Belarus, 220012 Minsk, Belarus.
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31
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Palmer J, Poon AFY. Phylogenetic measures of indel rate variation among the HIV-1 group M subtypes. Virus Evol 2019; 5:vez022. [PMID: 31341641 PMCID: PMC6642732 DOI: 10.1093/ve/vez022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The transmission fitness and pathogenesis of HIV-1 is disproportionately influenced by evolution in the five variable regions (V1–V5) of the surface envelope glycoprotein (gp120). Insertions and deletions (indels) are a significant source of evolutionary change in these regions. However, the rate and composition of indels has not yet been quantified through a large-scale comparative analysis of HIV-1 sequences. Here, we develop and report results from a phylogenetic method to estimate indel rates for the gp120 variable regions across five major subtypes and two circulating recombinant forms (CRFs) of HIV-1 group M. We processed over 26,000 published HIV-1 gp120 sequences, from which we extracted 6,605 sequences for phylogenetic analysis. We reconstructed time-scaled phylogenies by maximum likelihood and fit a binomial-Poisson model to the observed distribution of indels between closely related pairs of sequences in each tree (cherries). By focusing on cherries in each tree, we obtained phylogenetically independent indel reconstructions, and the shorter time scales in cherries reduced the bias due to purifying selection. Rate estimates ranged from 3.0×10−5 to 1.5×10−3 indels/nt/year and varied significantly among variable regions and subtypes. Indel rates were significantly lower in V3 relative to V1, and were also lower in HIV-1 subtype B relative to the 01_AE reference. We also found that V1, V2, and V4 tended to accumulate significantly longer indels. Furthermore, we observed that the nucleotide composition of indels was distinct from the flanking sequence, with higher frequencies of G and lower frequencies of T. Indels affected N-linked glycosylation sites more often in V1 and V2 than expected by chance, consistent with positive selection on glycosylation patterns within these regions. These results represent the first comprehensive measures of indel rates in HIV-1 gp120 across multiple subtypes and CRFs, and identifies novel and unexpected patterns for further research in the molecular evolution of HIV-1.
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Affiliation(s)
- John Palmer
- Department of Pathology & Laboratory Medicine, Western University, London, Canada
| | - Art F Y Poon
- Department of Pathology & Laboratory Medicine, Western University, London, Canada.,Department of Applied Mathematics, Western University, London, Canada.,Department of Microbiology & Immunology, Western University, London, Canada
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32
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Francica JR, Laga R, Lynn GM, Mužíková G, Androvič L, Aussedat B, Walkowicz WE, Padhan K, Ramirez-Valdez RA, Parks R, Schmidt SD, Flynn BJ, Tsybovsky Y, Stewart-Jones GBE, Saunders KO, Baharom F, Petrovas C, Haynes BF, Seder RA. Star nanoparticles delivering HIV-1 peptide minimal immunogens elicit near-native envelope antibody responses in nonhuman primates. PLoS Biol 2019; 17:e3000328. [PMID: 31206510 PMCID: PMC6597128 DOI: 10.1371/journal.pbio.3000328] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 06/27/2019] [Accepted: 05/31/2019] [Indexed: 12/16/2022] Open
Abstract
Peptide immunogens provide an approach to focus antibody responses to specific neutralizing sites on the HIV envelope protein (Env) trimer or on other pathogens. However, the physical characteristics of peptide immunogens can limit their pharmacokinetic and immunological properties. Here, we have designed synthetic “star” nanoparticles based on biocompatible N-[(2-hydroxypropyl)methacrylamide] (HPMA)-based polymer arms extending from a poly(amidoamine) (PAMAM) dendrimer core. In mice, these star nanoparticles trafficked to lymph nodes (LNs) by 4 hours following vaccination, where they were taken up by subcapsular macrophages and then resident dendritic cells (DCs). Immunogenicity optimization studies revealed a correlation of immunogen density with antibody titers. Furthermore, the co-delivery of Env variable loop 3 (V3) and T-helper peptides induced titers that were 2 logs higher than if the peptides were given in separate nanoparticles. Finally, we performed a nonhuman primate (NHP) study using a V3 glycopeptide minimal immunogen that was structurally optimized to be recognized by Env V3/glycan broadly neutralizing antibodies (bnAbs). When administered with a potent Toll-like receptor (TLR) 7/8 agonist adjuvant, these nanoparticles elicited high antibody binding titers to the V3 site. Similar to human V3/glycan bnAbs, certain monoclonal antibodies (mAbs) elicited by this vaccine were glycan dependent or targeted the GDIR peptide motif. To improve affinity to native Env trimer affinity, nonhuman primates (NHPs) were boosted with various SOSIP Env proteins; however, significant neutralization was not observed. Taken together, this study provides a new vaccine platform for administration of glycopeptide immunogens for focusing immune responses to specific bnAb epitopes. Synthetic polymer-based nanoparticles effectively deliver HIV Env glycopeptide immunogens to lymph nodes and stimulate B cell lineages with characteristics resembling broadly neutralizing antibodies, in nonhuman primates.
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Affiliation(s)
- Joseph R Francica
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Richard Laga
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Geoffrey M Lynn
- Avidea Technologies, Inc., Baltimore, Maryland, United States of America
| | - Gabriela Mužíková
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Ladislav Androvič
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Baptiste Aussedat
- Department of Chemical Biology, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - William E Walkowicz
- Department of Chemical Biology, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Kartika Padhan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ramiro Andrei Ramirez-Valdez
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Stephen D Schmidt
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Barbara J Flynn
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yaroslav Tsybovsky
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Guillaume B E Stewart-Jones
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Faezzah Baharom
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Constantinos Petrovas
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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Conformational Engineering of HIV-1 Env Based on Mutational Tolerance in the CD4 and PG16 Bound States. J Virol 2019; 93:JVI.00219-19. [PMID: 30894475 DOI: 10.1128/jvi.00219-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 03/16/2019] [Indexed: 12/22/2022] Open
Abstract
HIV-1 infection is initiated by viral Env engaging the host receptor CD4, triggering Env to transition from a "closed" to "open" conformation during the early events of virus-cell membrane fusion. To understand how Env sequence accommodates this conformational change, mutational landscapes decoupled from virus replication were determined for Env from BaL (clade B) and DU422 (clade C) isolates interacting with CD4 or antibody PG16 that preferentially recognizes closed trimers. Sequence features uniquely important to each bound state were identified, including glycosylation and binding sites. Notably, the Env apical domain and trimerization interface are under selective pressure for PG16 binding. Based on this key observation, mutations were found that increase presentation of quaternary epitopes associated with properly conformed trimers when Env is expressed at the plasma membrane. Many mutations reduce electrostatic repulsion at the Env apex and increase PG16 recognition of Env sequences from clades A and B. Other mutations increase hydrophobic packing at the gp120 inner-outer domain interface and were broadly applicable for engineering Env from diverse strains spanning tiers 1, 2, and 3 across clades A, B, C, and BC recombinants. Core mutations predicted to introduce steric strain in the open state show markedly reduced CD4 interactions. Finally, we demonstrate how our methodology can be adapted to interrogate interactions between membrane-associated Env and the matrix domain of Gag. These findings and methods may assist vaccine design.IMPORTANCE HIV-1 Env is dynamic and undergoes large conformational changes that drive fusion of virus and host cell membranes. Three Env proteins in a trimer contact each other at their apical tips to form a closed conformation that presents epitopes recognized by broadly neutralizing antibodies. The apical tips separate, among other changes, to form an open conformation that binds tightly to host receptors. Understanding how Env sequence facilitates these structural changes can inform the biophysical mechanism and aid immunogen design. Using deep mutational scans decoupled from virus replication, we report mutational landscapes for Env from two strains interacting with conformation-dependent binding proteins. Residues in the Env trimer interface and apical domains are preferentially conserved in the closed conformation, and conformational diversity is facilitated by electrostatic repulsion and an underpacked core between domains. Specific mutations are described that enhance presentation of the trimeric closed conformation across diverse HIV-1 strains.
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Munro JB, Lee KK. Probing Structural Variation and Dynamics in the HIV-1 Env Fusion Glycoprotein. Curr HIV Res 2019; 16:5-12. [PMID: 29268688 DOI: 10.2174/1570162x16666171222110025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Recent advances in structural characterization of the HIV envelope glycoprotein (Env) have provided a high-resolution glimpse of the architecture of this target for neutralizing antibodies and the machinery responsible for mediating receptor binding and membrane fusion. These structures primarily capture the detailed organization of the receptor-naive, prefusion conformation of Env, but under native solution conditions Env is highly dynamic, sampling multiple conformational states as well as exhibiting local protein flexibility. METHODS Special emphasis is placed on the use of biophysical methods, including single-molecule fluorescence microscopy and hydrogen/deuterium-exchange mass spectrometry. RESULTS Using novel biophysical approaches, striking isolate-specific differences in Env's dynamic profile have been revealed that appear to underlie phenotypic differences of the viral isolates such as neutralization sensitivity and CD4 receptor reactivity. CONCLUSION Structural studies are complemented by novel biophysical investigations that enable visualization of the dynamics of HIV-1 Env under native conditions. These approaches will also enable us to gain new insights into the mechanisms of action of antibodies and drugs.
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Affiliation(s)
- James B Munro
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States
| | - Kelly K Lee
- Department of Medicinal Chemistry and Biological Physics Structure and Design Program, University of Washington, Seattle, WA, United States
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Abstract
Purpose of review HIV-1 isolates are often classified on the basis of neutralization ‘tier’ phenotype. Tier classification has important implications for the monitoring and interpretation of vaccine-elicited neutralizing antibody responses. The molecular basis that distinguishes the multiple neutralization phenotypes of HIV-1 has been unclear. We present a model based on the dynamic nature of the HIV-1 envelope glycoproteins and its impact on epitope exposure. We also describe a new approach for ranking HIV-1 vaccine-elicited neutralizing antibody responses. Recent findings The unliganded trimeric HIV-1 envelope glycoprotein spike spontaneously transitions through at least three conformations. Neutralization tier phenotypes correspond to the frequency by which the trimer exists in a closed (tiers 2 and 3), open (tier 1A), or intermediate (tier 1B) conformation. An increasing number of epitopes become exposed as the trimer opens, making the virus more sensitive to neutralization by certain antibodies. The closed conformation is stabilized by many broadly neutralizing antibodies. Summary The tier 2 neutralization phenotype is typical of most circulating strains and is associated with a predominantly closed Env trimer configuration that is a high priority to target with vaccines. Assays with tier 1A viruses should be interpreted with caution and with the understanding that they detect many antibody specificities that do not neutralize tier 2 viruses and do not protect against HIV-1 infection.
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Kumar S, Sarkar A, Pugach P, Sanders RW, Moore JP, Ward AB, Wilson IA. Capturing the inherent structural dynamics of the HIV-1 envelope glycoprotein fusion peptide. Nat Commun 2019; 10:763. [PMID: 30770829 PMCID: PMC6377653 DOI: 10.1038/s41467-019-08738-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 01/25/2019] [Indexed: 02/04/2023] Open
Abstract
The N-terminal fusion peptide (FP) of the human immunodeficiency virus (HIV)-1 envelope glycoprotein (Env) gp41 subunit plays a critical role in cell entry. However, capturing the structural flexibility in the unbound FP is challenging in the native Env trimer. Here, FP conformational isomerism is observed in two crystal structures of a soluble clade B transmitted/founder virus B41 SOSIP.664 Env with broadly neutralizing antibodies (bNAbs) PGT124 and 35O22 to aid in crystallization and that are not specific for binding to the FP. Large rearrangements in the FP and fusion peptide proximal region occur around M530, which remains anchored in the tryptophan clasp (gp41 W623, W628, W631) in the B41 Env prefusion state. Further, we redesigned the FP at position 518 to reinstate the bNAb VRC34.01 epitope. These findings provide further structural evidence for the dynamic nature of the FP and how a bNAb epitope can be restored during vaccine design. The fusion peptide (FP) of HIV envelope (Env) is critical in the cell entry process. Here, Kumar et al. present crystal structures of B41 SOSIP.664 Env trimer and show the dynamic nature of the FP and proximal region, which likely relates to conformational rearrangements required for membrane fusion.
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Affiliation(s)
- Sonu Kumar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.,IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Anita Sarkar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.,IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Pavel Pugach
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Rogier W Sanders
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065, USA.,Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - John P Moore
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.,IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA. .,IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, 92037, USA. .,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, 92037, USA. .,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
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37
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Ivan B, Sun Z, Subbaraman H, Friedrich N, Trkola A. CD4 occupancy triggers sequential pre-fusion conformational states of the HIV-1 envelope trimer with relevance for broadly neutralizing antibody activity. PLoS Biol 2019; 17:e3000114. [PMID: 30650070 PMCID: PMC6351000 DOI: 10.1371/journal.pbio.3000114] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/29/2019] [Accepted: 01/04/2019] [Indexed: 12/18/2022] Open
Abstract
During the entry process, the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer undergoes a sequence of conformational changes triggered by both CD4 and coreceptor engagement. Resolving the conformation of these transient entry intermediates has proven challenging. Here, we fine-mapped the antigenicity of entry intermediates induced by increasing CD4 engagement of cell surface–expressed Env. Escalating CD4 triggering led to the sequential adoption of different pre-fusion conformational states of the Env trimer, up to the pre-hairpin conformation, that we assessed for antibody epitope presentation. Maximal accessibility of the coreceptor binding site was detected below Env saturation by CD4. Exposure of the fusion peptide and heptad repeat 1 (HR1) required higher CD4 occupancy. Analyzing the diverse antigenic states of the Env trimer, we obtained key insights into the transitions in epitope accessibility of broadly neutralizing antibodies (bnAbs). Several bnAbs preferentially bound CD4-triggered Env, indicating a potential capacity to neutralize both pre- and post-CD4 engagement, which needs to be explored. Assessing binding and neutralization activity of bnAbs, we confirm antibody dissociation rates as a driver of incomplete neutralization. Collectively, our findings highlight a need to resolve Env conformations that are neutralization-relevant to provide guidance for immunogen development. Comprehensive mapping of conformational stages adopted by the HIV‐1 envelope glycoprotein trimer during entry into the cell reveals the preference of broadly neutralizing antibodies for distinct pre-fusion states of the trimer. The trimeric human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) mediates HIV-1 entry into its target cells. Entry is initiated by sequential triggering of Env upon interaction with its primary receptor CD4 and a coreceptor on target cells. The ensuing structural rearrangements of the Env trimer bring the viral membrane in close vicinity of the cellular membrane, enabling fusion. Resolving the structural differences between the consecutive conformations Env adopts during the entry process is of high interest, as different antigenic domains are exposed, which may affect the capacity of neutralizing antibodies to bind to Env and inhibit entry. Here, we compared the conformation of unliganded closed Env with the transitional CD4-bound Env forms by studying the antigenicity of cell surface–expressed Env with and without CD4 triggering. We show that incremental triggering by soluble CD4 allows the capture of the full continuum of conformational changes, including events that follow coreceptor interaction. Thus, the setup we introduce here turns a simple binding assay into a powerful tool to study transitional conformation changes in HIV-1 Env. Analyzing the capacity of Env-reactive antibodies to recognize the diverse Env stages, our study reveals novel aspects of the binding preferences of neutralizing antibodies that affect their inhibitory activity.
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Affiliation(s)
- Branislav Ivan
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Zhaozhi Sun
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Harini Subbaraman
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Nikolas Friedrich
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Alexandra Trkola
- Institute of Medical Virology, University of Zurich, Zurich, Switzerland
- * E-mail:
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38
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Wang H, Barnes CO, Yang Z, Nussenzweig MC, Bjorkman PJ. Partially Open HIV-1 Envelope Structures Exhibit Conformational Changes Relevant for Coreceptor Binding and Fusion. Cell Host Microbe 2018; 24:579-592.e4. [PMID: 30308160 PMCID: PMC6185872 DOI: 10.1016/j.chom.2018.09.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/20/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022]
Abstract
HIV-1 Env, a trimer of gp120-gp41 heterodimers, mediates membrane fusion after binding host receptor CD4. Receptor binding displaces V1V2 loops from Env's apex, allowing coreceptor binding and opening Env to enable gp41-mediated fusion. We present 3.54 Å and 4.06 Å cryoelectron microscopy structures of partially open soluble native-like Env trimers (SOSIPs) bound to CD4. One structure, a complex with a coreceptor-mimicking antibody that binds both CD4 and gp120, stabilizes the displaced V1V2 and reveals its structure. Comparing partially and fully open Envs with closed Envs shows that gp41 rearrangements are independent of the CD4-induced rearrangements that result in V1V2 displacement and formation of a 4-stranded bridging sheet. These findings suggest ordered conformational changes before coreceptor binding: (1) gp120 opening inducing side-chain rearrangements and a compact gp41 central helix conformation, and (2) 4-stranded bridging-sheet formation and V1V2 displacement. These analyses illuminate potential receptor-induced Env changes and inform design of therapeutics disrupting viral entry. Cryo-EM structures of HIV-1 Env trimer in CD4-bound, partially open conformation CD4-induced conformational changes of HIV-1 Env V1V2 region Mechanism of Env trimer opening and coreceptor binding site exposure Structural biology models for early stages of HIV-1 Env-mediated membrane fusion
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Affiliation(s)
- Haoqing Wang
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Christopher O Barnes
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Zhi Yang
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA.
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Falkenhagen A, Joshi S. HIV Entry and Its Inhibition by Bifunctional Antiviral Proteins. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 13:347-364. [PMID: 30340139 PMCID: PMC6197789 DOI: 10.1016/j.omtn.2018.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 12/14/2022]
Abstract
HIV entry is a highly specific and time-sensitive process that can be divided into receptor binding, coreceptor binding, and membrane fusion. Bifunctional antiviral proteins (bAVPs) exploit the multi-step nature of the HIV entry process by binding to two different extracellular targets. They are generated by expressing a fusion protein containing two entry inhibitors with a flexible linker. The resulting fusion proteins exhibit exceptional neutralization potency and broad cross-clade inhibition. In this review, we summarize the HIV entry process and provide an overview of the design, antiviral potency, and methods of delivery of bAVPs. Additionally, we discuss the advantages and limitations of bAVPs for HIV prevention and treatment.
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Affiliation(s)
- Alexander Falkenhagen
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Sadhna Joshi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E2, Canada.
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40
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Flemming J, Wiesen L, Herschhorn A. Conformation-Dependent Interactions Between HIV-1 Envelope Glycoproteins and Broadly Neutralizing Antibodies. AIDS Res Hum Retroviruses 2018; 34:794-803. [PMID: 29905080 DOI: 10.1089/aid.2018.0102] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
HIV type 1 (HIV-1) envelope glycoproteins (Env) mediate virus entry and are the target of neutralizing antibodies. Binding of the metastable HIV-1 Env trimer to the CD4 receptor triggers structural rearrangements that mediate Env conformational transitions from a closed conformation to a more open state through an intermediate step. Recent studies have revealed new insights on the dynamics, regulation, and molecular mechanisms of Env transitions along the entry pathway. In this study, we provide an overview of the current knowledge on Env conformational dynamics and the relationship between Env conformational states and neutralization selectivity of the broadly neutralizing antibodies that develop in 10%-20% of infected individuals and may provide guidance for the development of an effective HIV-1 vaccine.
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Affiliation(s)
- Juliana Flemming
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Lisa Wiesen
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Alon Herschhorn
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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41
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Stadtmueller BM, Bridges MD, Dam KM, Lerch MT, Huey-Tubman KE, Hubbell WL, Bjorkman PJ. DEER Spectroscopy Measurements Reveal Multiple Conformations of HIV-1 SOSIP Envelopes that Show Similarities with Envelopes on Native Virions. Immunity 2018; 49:235-246.e4. [PMID: 30076100 PMCID: PMC6104740 DOI: 10.1016/j.immuni.2018.06.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/15/2018] [Accepted: 06/28/2018] [Indexed: 12/31/2022]
Abstract
HIV-1 Envelope (Env) mediates viral-host membrane fusion after binding host-receptor CD4 and coreceptor. Soluble envelopes (SOSIPs), designed to mimic prefusion conformational states of virion-bound envelopes, are proposed immunogens for eliciting neutralizing antibodies, yet only static structures are available. To evaluate conformational landscapes of ligand-free, CD4-bound, inhibitor-bound, and antibody-bound SOSIPs, we measured inter-subunit distances throughout spin-labeled SOSIPs using double electron-electron resonance (DEER) spectroscopy and compared results to soluble and virion-bound Env structures, and single-molecule fluorescence resonance energy transfer (smFRET)-derived dynamics of virion-bound Envs. Unliganded SOSIP measurements were consistent with closed, neutralizing antibody-bound structures and shielding of non-neutralizing epitopes, demonstrating homogeneity at Env apex, increased flexibility near Env base, and no evidence for the intra-subunit flexibility near Env apex suggested by smFRET. CD4 binding increased inter-subunit distances and heterogeneity, consistent with rearrangements required for coreceptor binding. Results suggest similarities between SOSIPs and virion-bound Envs and demonstrate DEER’s relevance for immunogen design. SOSIP Env apex is 3-fold symmetric and consistent with closed prefusion structures Unliganded Env base and CD4-bound Env apex and base exhibit flexibility SOSIPs retain desired properties of immunogens; e.g., burying non-neutralizing epitopes Results allow interpretation of smFRET studies and SOSIP and virion Env structures
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Affiliation(s)
- Beth M Stadtmueller
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael D Bridges
- Jules Stein Eye Institute, University of California, Los Angeles, CA 90095, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Kim-Marie Dam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael T Lerch
- Jules Stein Eye Institute, University of California, Los Angeles, CA 90095, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Kathryn E Huey-Tubman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Wayne L Hubbell
- Jules Stein Eye Institute, University of California, Los Angeles, CA 90095, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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42
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Dutta M. Recent Advances in Single Particle Cryo-electron Microscopy and Cryo-electron Tomography to Determine the Structures of Biological Macromolecules. J Indian Inst Sci 2018. [DOI: 10.1007/s41745-018-0087-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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43
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Boliar S, Patil S, Shukla BN, Ghobbeh A, Deshpande S, Chen W, Guenaga J, Dimitrov DS, Wyatt RT, Chakrabarti BK. Ligand accessibility to the HIV-1 Env co-receptor binding site can occur prior to CD4 engagement and is independent of viral tier category. Virology 2018; 519:99-105. [PMID: 29684630 DOI: 10.1016/j.virol.2018.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 11/28/2022]
Abstract
HIV-1 virus entry into target cells requires the envelope glycoprotein (Env) to first bind the primary receptor, CD4 and subsequently the co-receptor. Antibody access to the co-receptor binding site (CoRbs) in the pre-receptor-engaged state, prior to cell attachment, remains poorly understood. Here, we have demonstrated that for tier-1 Envs, the CoRbs is directly accessible to full-length CD4-induced (CD4i) antibodies even before primary receptor engagement, indicating that on these Envs the CoRbs site is either preformed or can conformationally sample post-CD4-bound state. Tier-2 and tier-3 Envs, which are resistant to full-length CD4i antibody, are neutralized by m36.4, a lower molecular mass of CD4i-directed domain antibody. In some tier-2 and tier-3 Envs, CoRbs is accessible to m36.4 even prior to cellular attachment in an Env-specific manner independent of their tier category. These data suggest differential structural arrangements of CoRbs and varied masking of ligand access to the CoRbs in different Env isolates.
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Affiliation(s)
- Saikat Boliar
- THSTI-IAVI HIV Vaccine Translational Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana 121001, India
| | - Shilpa Patil
- THSTI-IAVI HIV Vaccine Translational Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana 121001, India
| | - Brihaspati N Shukla
- THSTI-IAVI HIV Vaccine Translational Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana 121001, India
| | - Ali Ghobbeh
- IAVI Neutralizing Antibody Center at TSRI, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Suprit Deshpande
- THSTI-IAVI HIV Vaccine Translational Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana 121001, India
| | - Weizao Chen
- Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Javier Guenaga
- IAVI Neutralizing Antibody Center at TSRI, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Dimiter S Dimitrov
- Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Richard T Wyatt
- IAVI Neutralizing Antibody Center at TSRI, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Bimal K Chakrabarti
- THSTI-IAVI HIV Vaccine Translational Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana 121001, India; IAVI Neutralizing Antibody Center at TSRI, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Structural Transition and Antibody Binding of EBOV GP and ZIKV E Proteins from Pre-Fusion to Fusion-Initiation State. Biomolecules 2018; 8:biom8020025. [PMID: 29748487 PMCID: PMC6022868 DOI: 10.3390/biom8020025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 11/17/2022] Open
Abstract
Membrane fusion proteins are responsible for viral entry into host cells—a crucial first step in viral infection. These proteins undergo large conformational changes from pre-fusion to fusion-initiation structures, and, despite differences in viral genomes and disease etiology, many fusion proteins are arranged as trimers. Structural information for both pre-fusion and fusion-initiation states is critical for understanding virus neutralization by the host immune system. In the case of Ebola virus glycoprotein (EBOV GP) and Zika virus envelope protein (ZIKV E), pre-fusion state structures have been identified experimentally, but only partial structures of fusion-initiation states have been described. While the fusion-initiation structure is in an energetically unfavorable state that is difficult to solve experimentally, the existing structural information combined with computational approaches enabled the modeling of fusion-initiation state structures of both proteins. These structural models provide an improved understanding of four different neutralizing antibodies in the prevention of viral host entry.
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de Castro S, Camarasa MJ. Polypharmacology in HIV inhibition: can a drug with simultaneous action against two relevant targets be an alternative to combination therapy? Eur J Med Chem 2018. [PMID: 29529501 DOI: 10.1016/j.ejmech.2018.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
HIV infection still has a serious health and socio-economical impact and is one of the primary causes of morbidity and mortality all over the world. HIV infection and the AIDS pandemic are still matters of great concern, especially in less developed countries where the access to highly active antiretroviral therapy (HAART) is limited. Patient compliance is another serious drawback. Nowadays, HAART is the treatment of choice although it is not the panacea. Despite the fact that it suppresses viral replication at undetectable viral loads and prevents progression of HIV infection into AIDS HAART has several pitfalls, namely, long-term side-effects, drug resistance development, emergence of drug-resistant viruses, low compliance and the intolerance of some patients to these drugs. Moreover, another serious health concern is the event of co-infection with more than one pathogen at the same time (e.g. HIV and HCV, HBV, herpes viruses, etc). Currently, the multi-target drug approach has become an exciting strategy to address complex diseases and overcome drug resistance development. Such multifunctional molecules combine in their structure pharmacophores that may simultaneously interfere with multiple targets and their use may eventually be more safe and efficacious than that involving a mixture of separate molecules because of avoidance or delay of drug resistance, lower incidence of unwanted drug-drug interactions and improved compliance. In this review we focus on multifunctional molecules with dual activity against different targets of the HIV life cycle or able to block replication, not only of HIV but also of other viruses that are often co-pathogens of HIV. The different approaches are documented by selected examples.
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Affiliation(s)
- Sonia de Castro
- Instituto de Química Médica (IQM, CSIC) Juan de La Cierva 3, E-28006 Madrid, Spain
| | - María-José Camarasa
- Instituto de Química Médica (IQM, CSIC) Juan de La Cierva 3, E-28006 Madrid, Spain.
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Herschhorn A, Gu C, Moraca F, Ma X, Farrell M, Smith AB, Pancera M, Kwong PD, Schön A, Freire E, Abrams C, Blanchard SC, Mothes W, Sodroski JG. The β20-β21 of gp120 is a regulatory switch for HIV-1 Env conformational transitions. Nat Commun 2017; 8:1049. [PMID: 29051495 PMCID: PMC5648922 DOI: 10.1038/s41467-017-01119-w] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/18/2017] [Indexed: 11/09/2022] Open
Abstract
The entry of HIV-1 into target cells is mediated by the viral envelope glycoproteins (Env). Binding to the CD4 receptor triggers a cascade of conformational changes in distant domains that move Env from a functionally “closed” State 1 to more “open” conformations, but the molecular mechanisms underlying allosteric regulation of these transitions are still elusive. Here, we develop chemical probes that block CD4-induced conformational changes in Env and use them to identify a potential control switch for Env structural rearrangements. We identify the gp120 β20–β21 element as a major regulator of Env transitions. Several amino acid changes in the β20–β21 base lead to open Env conformations, recapitulating the structural changes induced by CD4 binding. These HIV-1 mutants require less CD4 to infect cells and are relatively resistant to State 1-preferring broadly neutralizing antibodies. These data provide insights into the molecular mechanism and vulnerability of HIV-1 entry. Binding of viral envelope glycoproteins (Env) to the host cell CD4 receptor mediates HIV-1 entry. Here, the authors develop compounds that inhibit the CD4-induced conformational changes in Env and show that the gp120 β20-β21 element is a key regulator for Env transitions.
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Affiliation(s)
- Alon Herschhorn
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, 02215, USA. .,Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, 02115, USA.
| | - Christopher Gu
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, 02215, USA
| | - Francesca Moraca
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania, 19104, USA
| | - Xiaochu Ma
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, 06536, USA
| | - Mark Farrell
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Amos B Smith
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Marie Pancera
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, 21218, USA
| | - Ernesto Freire
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, 21218, USA
| | - Cameron Abrams
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania, 19104, USA
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, 10065, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, 06536, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, 02215, USA. .,Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, 02115, USA. .,Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, 02115, USA.
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Abstract
BACKGROUND HIV-1 is known to adapt to the local environment in its usage of receptors, and it can become CD4 independent in the brain where the receptor is scarce. This adaptation is through amino acid variations, but the patterns of such variation are not yet well understood. Given that infection of long-lived CD4-low and CD4-negative cells in anatomical compartments such as the brain expands cell tropism in vivo and may serve as potential viral reservoirs that pose challenge for HIV eradication, understanding the evolution to CD4 independence and envelope conformation associated with infection in the absence of CD4 will not only broaden our insights into HIV pathogenesis but may guide functional cure strategies as well. METHODS We characterize, by site-directed mutagenesis, neutralization assay, and structural analysis, a pair of CD4-dependent (cl2) and CD4-independent (cl20) envelopes concurrently isolated from the cerebral spinal fluid of an SHIV-infected macaque with neurological AIDS and with minimum sequence differences. RESULTS Residues different between cl2 and cl20 are mapped to the V1V2 and surrounding regions. Mutations of these residues in cl2 increased its CD4 independence in infection, and the effects are cumulative and likely structural. CONCLUSIONS Our data suggested that the determinants of CD4 independence in vivo mapped principally to V1V2 of gp120 that can destabilize the apex of the envelope spike, with an additional change in V4 that abrogated a potential N-linked glycan to facilitate movement of the V1V2 domain and further expose the coreceptor-binding site.
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48
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Abstract
Structure determination of the HIV-1 envelope glycoprotein (Env) presented a number of challenges, but several high-resolution structures have now become available. In 2013, cryo-EM and x-ray structures of soluble, cleaved SOSIP Env trimers from the clade A BG505 strain provided the first glimpses into the Env trimer fold as well as more the variable regions. A recent cryo-EM structure of a native full-length trimer without any stabilizing mutations had the same core structure, but revealed new insights and features. A more comprehensive and higher resolution understanding of the glycan shield has also emerged, enabling a more complete representation of the Env glycoprotein structure. Complexes of Env trimers with broadly neutralizing antibodies have surprisingly illustrated that most of the Env surface can be targeted in natural infection and that the neutralizing epitopes are almost all composed of both peptide and glycan components. These structures have also provided further evidence of the inherent plasticity of Env and how antibodies can exploit this flexibility by perturbing or even stabilizing the trimer to facilitate neutralization. These breakthroughs have stimulated further design and stabilization of Env trimers as well as other platforms to generate trimers that now span multiple subtypes. These Env trimers when used as immunogens, have led to the first vaccine-induced neutralizing antibodies for structural and functional analyses.
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Affiliation(s)
- Andrew B Ward
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery, and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, La Jolla, CA, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery, and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, La Jolla, CA, USA.,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
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Structure of Simian Immunodeficiency Virus Envelope Spikes Bound with CD4 and Monoclonal Antibody 36D5. J Virol 2017; 91:JVI.00134-17. [PMID: 28539445 DOI: 10.1128/jvi.00134-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/14/2017] [Indexed: 01/29/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1)/simian immunodeficiency virus (SIV) envelope spike (Env) mediates viral entry into host cells. The V3 loop of the gp120 component of the Env trimer contributes to the coreceptor binding site and is a target for neutralizing antibodies. We used cryo-electron tomography to visualize the binding of CD4 and the V3 loop monoclonal antibody (MAb) 36D5 to gp120 of the SIV Env trimer. Our results show that 36D5 binds gp120 at the base of the V3 loop and suggest that the antibody exerts its neutralization effect by blocking the coreceptor binding site. The antibody does this without altering the dynamics of the spike motion between closed and open states when CD4 is bound. The interaction between 36D5 and SIV gp120 is similar to the interaction between some broadly neutralizing anti-V3 loop antibodies and HIV-1 gp120. Two conformations of gp120 bound with CD4 are revealed, suggesting an intrinsic dynamic nature of the liganded Env trimer. CD4 binding substantially increases the binding of 36D5 to gp120 in the intact Env trimer, consistent with CD4-induced changes in the conformation of gp120 and the antibody binding site. Binding by MAb 36D5 does not substantially alter the proportions of the two CD4-bound conformations. The position of MAb 36D5 at the V3 base changes little between conformations, indicating that the V3 base serves as a pivot point during the transition between these two states.IMPORTANCE Glycoprotein spikes on the surfaces of SIV and HIV are the sole targets available to the immune system for antibody neutralization. Spikes evade the immune system by a combination of a thick layer of polysaccharide on the surface (the glycan shield) and movement between spike domains that masks the epitope conformation. Using SIV virions whose spikes were "decorated" with the primary cellular receptor (CD4) and an antibody (36D5) at part of the coreceptor binding site, we visualized multiple conformations trapped by the rapid freezing step, which were separated using statistical analysis. Our results show that the CD4-induced conformational dynamics of the spike enhances binding of the antibody.
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How HIV-1 entry mechanism and broadly neutralizing antibodies guide structure-based vaccine design. Curr Opin HIV AIDS 2017; 12:229-240. [PMID: 28422787 DOI: 10.1097/coh.0000000000000360] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW An HIV-1 vaccine that elicits broadly neutralizing antibodies (bNAbs) remains to be developed. Here, we review how knowledge of bNAbs and HIV-1 entry mechanism is guiding the structure-based design of vaccine immunogens and immunization regimens. RECENT FINDINGS Isolation of bNAbs from HIV-1-infected donors has led to an unprecedented understanding of the sites of vulnerability that these antibodies target on the HIV-1 envelope (Env) as well as of the immunological pathways that these antibody lineages follow to develop broad and potent neutralization. Sites of vulnerability, however, reside in the context of diverse Env conformations required for HIV-1 entry, including a prefusion-closed state, a single-CD4-bound intermediate, a three-CD4-bound intermediate, a prehairpin intermediate and postfusion states, and it is not always clear which structural state optimally presents a particular site of vulnerability in the vaccine context. Furthermore, detailed knowledge of immunological pathways has led to debate among vaccine developers as to how much of the natural antibody-developmental pathway immunogens should mimic, ranging from only the recognized epitope to multiple antigens from the antibody-virus coevolution process. SUMMARY A plethora of information on bNAbs is guiding HIV-1-vaccine development. We highlight consideration of the appropriate structural context from the HIV-1-entry mechanism and extraordinary progress with replicating template B-cell ontogenies.
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