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Hariharan V, Kane RS. Glycosylation as a tool for rational vaccine design. Biotechnol Bioeng 2020; 117:2556-2570. [PMID: 32330286 DOI: 10.1002/bit.27361] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 04/01/2020] [Accepted: 04/22/2020] [Indexed: 12/31/2022]
Abstract
The discovery of broadly neutralizing antibodies that can neutralize multiple strains or subtypes of a pathogen has renewed interest in the development of broadly protective vaccines. To that end, there has been an interest in designing immunofocusing strategies to direct the immune response to specific, conserved regions on antigenic proteins. Modulation of glycosylation is one such immunofocusing strategy; extensive glycosylation is often exploited by pathogens for immune evasion. Masking epitopes on protein immunogens with "self" glycans can also shield the underlying protein surface from humoral immune surveillance. We review recent advances in applying glycosylation as an immunofocusing tool. We also highlight recent interesting work in the HIV-1 field involving the identification and elicitation of broadly neutralizing antibodies that incorporate glycans into their binding epitopes.
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Affiliation(s)
- Vivek Hariharan
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Ravi S Kane
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia
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2
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Agrawal P, DeVico AL, Foulke JS, Lewis GK, Pazgier M, Ray K. Stoichiometric Analyses of Soluble CD4 to Native-like HIV-1 Envelope by Single-Molecule Fluorescence Spectroscopy. Cell Rep 2019; 29:176-186.e4. [PMID: 31577947 PMCID: PMC6897359 DOI: 10.1016/j.celrep.2019.08.074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 06/17/2019] [Accepted: 08/23/2019] [Indexed: 01/14/2023] Open
Abstract
Analyses of HIV-1 envelope (Env) binding to CD4, and the conformational changes the interactions induce, inform the molecular mechanisms and factors governing HIV-1 infection. To address these questions, we used a single-molecule detection (SMD) approach to study the nature of reactions between soluble CD4 (sCD4) and soluble HIV-1 trimers. SMD of these reactions distinguished a mixture of one, two, or three CD4-bound trimer species. Single-ligand trimers were favored at early reaction times and ligand-saturated trimers later. Furthermore, some trimers occupied by one sCD4 molecule did not bind additional ligands, whereas the majority of two ligand-bound species rapidly transitioned to the saturated state. Quantification of liganded trimers observed in reactions with various sCD4 concentrations reflected an overall negative cooperativity in ligand binding. Collectively, our results highlight the general utility of SMD in studying protein interactions and provide critical insights on the nature of sCD4-HIV-1 Env interactions.
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Affiliation(s)
- Parul Agrawal
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Anthony L DeVico
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA; Department of Medicine, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - James S Foulke
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - George K Lewis
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Marzena Pazgier
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Krishanu Ray
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA.
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3
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HIV-1 Vaccines Based on Antibody Identification, B Cell Ontogeny, and Epitope Structure. Immunity 2018; 48:855-871. [DOI: 10.1016/j.immuni.2018.04.029] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
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Gao Y, Wijewardhana C, Mann JFS. Virus-Like Particle, Liposome, and Polymeric Particle-Based Vaccines against HIV-1. Front Immunol 2018. [PMID: 29541072 PMCID: PMC5835502 DOI: 10.3389/fimmu.2018.00345] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It is acknowledged that vaccines remain the best hope for eliminating the HIV-1 epidemic. However, the failure to produce effective vaccine immunogens and the inability of conventional delivery strategies to elicit the desired immune responses remains a central theme and has ultimately led to a significant roadblock in HIV vaccine development. Consequently, significant efforts have been applied to generate novel vaccine antigens and delivery agents, which mimic viral structures for optimal immune induction. Here, we review the latest developments that have occurred in the nanoparticle vaccine field, with special emphasis on strategies that are being utilized to attain highly immunogenic, systemic, and mucosal anti-HIV humoral and cellular immune responses. This includes the design of novel immunogens, the central role of antigen-presenting cells, delivery routes, and biodistribution of nanoparticles to lymph nodes. In particular, we will focus on virus-like-particle formulations and their preclinical uses within the HIV prophylactic vaccine setting.
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Affiliation(s)
- Yong Gao
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada
| | - Chanuka Wijewardhana
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada
| | - Jamie F S Mann
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada
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5
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Nguyen HT, Madani N, Ding H, Elder E, Princiotto A, Gu C, Darby P, Alin J, Herschhorn A, Kappes JC, Mao Y, Sodroski JG. Evaluation of the contribution of the transmembrane region to the ectodomain conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein. Virol J 2017; 14:33. [PMID: 28209172 PMCID: PMC5314615 DOI: 10.1186/s12985-017-0704-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/10/2017] [Indexed: 12/26/2022] Open
Abstract
Background The human immunodeficiency virus (HIV-1) envelope glycoprotein (Env), a Type 1 transmembrane protein, assembles into a trimeric spike complex that mediates virus entry into host cells. The high potential energy of the metastable, unliganded Env trimer is maintained by multiple non-covalent contacts among the gp120 exterior and gp41 transmembrane Env subunits. Structural studies suggest that the gp41 transmembrane region forms a left-handed coiled coil that contributes to the Env trimer interprotomer contacts. Here we evaluate the contribution of the gp41 transmembrane region to the folding and stability of Env trimers. Methods Multiple polar/charged amino acid residues, which hypothetically disrupt the stop-transfer signal, were introduced in the proposed lipid-interactive face of the transmembrane coiled coil, allowing release of soluble cleavage-negative Envs containing the modified transmembrane region (TMmod). We also examined effects of cleavage, the cytoplasmic tail and a C-terminal fibritin trimerization (FT) motif on oligomerization, antigenicity and functionality of soluble and membrane-bound Envs. Results The introduction of polar/charged amino acids into the transmembrane region resulted in the secretion of soluble Envs from the cell. However, these TMmod Envs primarily formed dimers. By contrast, control cleavage-negative sgp140 Envs lacking the transmembrane region formed soluble trimers, dimers and monomers. TMmod and sgp140 trimers were stabilized by the addition of a C-terminal FT sequence, but still exhibited carbohydrate and antigenic signatures of a flexible ectodomain structure. On the other hand, detergent-solubilized cleaved and uncleaved Envs isolated from the membranes of expressing cells exhibited "tighter” ectodomain structures, based on carbohydrate modifications. These trimers were found to be unstable in detergent solutions, but could be stabilized by the addition of a C-terminal FT moiety. The C-terminal FT domain decreased Env cleavage and syncytium-forming ability by approximately three-fold; alteration of the FT trimerization interface restored Env cleavage and syncytium formation to near-wild-type levels. Conclusion The modified transmembrane region was not conducive to trimerization of soluble Envs. However, for HIV-1 Env ectodomains that are minimally modified, membrane-anchored Envs exhibit the most native structures and can be stabilized by appropriately positioned FT domains.
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Affiliation(s)
- Hanh T Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Navid Madani
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Emerald Elder
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Amy Princiotto
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Christopher Gu
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Patrice Darby
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - James Alin
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Alon Herschhorn
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL, 35233, USA
| | - Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA. .,Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02215, USA.
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6
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Kesavardhana S, Das R, Citron M, Datta R, Ecto L, Srilatha NS, DiStefano D, Swoyer R, Joyce JG, Dutta S, LaBranche CC, Montefiori DC, Flynn JA, Varadarajan R. Structure-based Design of Cyclically Permuted HIV-1 gp120 Trimers That Elicit Neutralizing Antibodies. J Biol Chem 2016; 292:278-291. [PMID: 27879316 DOI: 10.1074/jbc.m116.725614] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 11/18/2016] [Indexed: 11/06/2022] Open
Abstract
A major goal for HIV-1 vaccine development is an ability to elicit strong and durable broadly neutralizing antibody (bNAb) responses. The trimeric envelope glycoprotein (Env) spikes on HIV-1 are known to contain multiple epitopes that are susceptible to bNAbs isolated from infected individuals. Nonetheless, all trimeric and monomeric Env immunogens designed to date have failed to elicit such antibodies. We report the structure-guided design of HIV-1 cyclically permuted gp120 that forms homogeneous, stable trimers, and displays enhanced binding to multiple bNAbs, including VRC01, VRC03, VRC-PG04, PGT128, and the quaternary epitope-specific bNAbs PGT145 and PGDM1400. Constructs that were cyclically permuted in the V1 loop region and contained an N-terminal trimerization domain to stabilize V1V2-mediated quaternary interactions, showed the highest homogeneity and the best antigenic characteristics. In guinea pigs, a DNA prime-protein boost regimen with these new gp120 trimer immunogens elicited potent neutralizing antibody responses against highly sensitive Tier 1A isolates and weaker neutralizing antibody responses with an average titer of about 115 against a panel of heterologous Tier 2 isolates. A modest fraction of the Tier 2 virus neutralizing activity appeared to target the CD4 binding site on gp120. These results suggest that cyclically permuted HIV-1 gp120 trimers represent a viable platform in which further modifications may be made to eventually achieve protective bNAb responses.
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Affiliation(s)
- Sannula Kesavardhana
- From the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Raksha Das
- From the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Michael Citron
- Merck & Company, Inc., West Point, Pennsylvania 19486, and
| | - Rohini Datta
- From the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Linda Ecto
- Merck & Company, Inc., West Point, Pennsylvania 19486, and
| | | | | | - Ryan Swoyer
- Merck & Company, Inc., West Point, Pennsylvania 19486, and
| | - Joseph G Joyce
- Merck & Company, Inc., West Point, Pennsylvania 19486, and
| | - Somnath Dutta
- From the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Celia C LaBranche
- the Department of Surgery, Duke University, Durham, North Carolina 27705
| | - David C Montefiori
- the Department of Surgery, Duke University, Durham, North Carolina 27705
| | | | - Raghavan Varadarajan
- From the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India,
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7
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New Member of the V1V2-Directed CAP256-VRC26 Lineage That Shows Increased Breadth and Exceptional Potency. J Virol 2015; 90:76-91. [PMID: 26468542 DOI: 10.1128/jvi.01791-15] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/21/2015] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED The epitopes defined by HIV-1 broadly neutralizing antibodies (bNAbs) are valuable templates for vaccine design, and studies of the immunological development of these antibodies are providing insights for vaccination strategies. In addition, the most potent and broadly reactive of these bNAbs have potential for clinical use. We previously described a family of 12 V1V2-directed neutralizing antibodies, CAP256-VRC26, isolated from an HIV-1 clade C-infected donor at years 1, 2, and 4 of infection (N. A. Doria-Rose et al., Nature 509:55-62, 2014, http://dx.doi.org/10.1038/nature13036). Here, we report on the isolation and characterization of new members of the family mostly obtained at time points of peak serum neutralization breadth and potency. Thirteen antibodies were isolated from B cell culture, and eight were isolated using trimeric envelope probes for differential single B cell sorting. One of the new antibodies displayed a 10-fold greater neutralization potency than previously published lineage members. This antibody, CAP256-VRC26.25, neutralized 57% of diverse clade viral isolates and 70% of clade C isolates with remarkable potency. Among the viruses neutralized, the median 50% inhibitory concentration was 0.001 μg/ml. All 33 lineage members targeted a quaternary epitope focused on V2. While all known bNAbs targeting the V1V2 region interact with the N160 glycan, the CAP256-VRC26 antibodies showed an inverse correlation of neutralization potency with dependence on this glycan. Overall, our results highlight the ongoing evolution within a single antibody lineage and describe more potent and broadly neutralizing members with potential clinical utility, particularly in areas where clade C is prevalent. IMPORTANCE Studies of HIV-1 broadly neutralizing antibodies (bNAbs) provide valuable information for vaccine design, and the most potent and broadly reactive of these bNAbs have potential for clinical use. We previously described a family of V1V2-directed neutralizing antibodies from an HIV-1 clade C-infected donor. Here, we report on the isolation and characterization of new members of the family mostly obtained at time points of peak serum neutralization breadth and potency. One of the new antibodies, CAP256-VRC26.25, displayed a 10-fold greater neutralization potency than previously described lineage members. It neutralized 57% of diverse clade viral isolates and 70% of clade C isolates with remarkable potency: the median 50% inhibitory concentration was 0.001 μg/ml. Our results highlight the ongoing evolution within a single antibody lineage and describe more potent and broadly neutralizing members with potential clinical utility, particularly in areas where clade C is prevalent.
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Kwon YD, Pancera M, Acharya P, Georgiev IS, Crooks ET, Gorman J, Joyce MG, Guttman M, Ma X, Narpala S, Soto C, Terry DS, Yang Y, Zhou T, Ahlsen G, Bailer RT, Chambers M, Chuang GY, Doria-Rose NA, Druz A, Hallen MA, Harned A, Kirys T, Louder MK, O'Dell S, Ofek G, Osawa K, Prabhakaran M, Sastry M, Stewart-Jones GBE, Stuckey J, Thomas PV, Tittley T, Williams C, Zhang B, Zhao H, Zhou Z, Donald BR, Lee LK, Zolla-Pazner S, Baxa U, Schön A, Freire E, Shapiro L, Lee KK, Arthos J, Munro JB, Blanchard SC, Mothes W, Binley JM, McDermott AB, Mascola JR, Kwong PD. Crystal structure, conformational fixation and entry-related interactions of mature ligand-free HIV-1 Env. Nat Struct Mol Biol 2015; 22:522-31. [PMID: 26098315 PMCID: PMC4706170 DOI: 10.1038/nsmb.3051] [Citation(s) in RCA: 290] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/29/2015] [Indexed: 12/19/2022]
Abstract
As the sole viral antigen on the HIV-1-virion surface, trimeric Env is a focus of vaccine efforts. Here we present the structure of the ligand-free HIV-1-Env trimer, fix its conformation and determine its receptor interactions. Epitope analyses revealed trimeric ligand-free Env to be structurally compatible with broadly neutralizing antibodies but not poorly neutralizing ones. We coupled these compatibility considerations with binding antigenicity to engineer conformationally fixed Envs, including a 201C 433C (DS) variant specifically recognized by broadly neutralizing antibodies. DS-Env retained nanomolar affinity for the CD4 receptor, with which it formed an asymmetric intermediate: a closed trimer bound by a single CD4 without the typical antigenic hallmarks of CD4 induction. Antigenicity-guided structural design can thus be used both to delineate mechanism and to fix conformation, with DS-Env trimers in virus-like-particle and soluble formats providing a new generation of vaccine antigens.
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Affiliation(s)
- Young Do Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Marie Pancera
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Priyamvada Acharya
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Ivelin S Georgiev
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Emma T Crooks
- San Diego Biomedical Research Institute, San Diego, California, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - M Gordon Joyce
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | - Xiaochu Ma
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sandeep Narpala
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Cinque Soto
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Daniel S Terry
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, USA
| | - Yongping Yang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Goran Ahlsen
- 1] Department of Biochemistry &Molecular Biophysics, Columbia University, New York, New York, USA. [2] Department of Systems Biology, Columbia University, New York, New York, USA
| | - Robert T Bailer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Michael Chambers
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Aliaksandr Druz
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Mark A Hallen
- 1] Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA. [2] Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA
| | - Adam Harned
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Tatsiana Kirys
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Mark K Louder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Sijy O'Dell
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Gilad Ofek
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Keiko Osawa
- San Diego Biomedical Research Institute, San Diego, California, USA
| | - Madhu Prabhakaran
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Mallika Sastry
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Guillaume B E Stewart-Jones
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Jonathan Stuckey
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Paul V Thomas
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Tishina Tittley
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Baoshan Zhang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Hong Zhao
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, USA
| | - Zhou Zhou
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, USA
| | - Bruce R Donald
- 1] Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA. [2] Department of Chemistry, Duke University, Durham, North Carolina, USA. [3] Department of Computer Science, Duke University, Durham, North Carolina, USA
| | - Lawrence K Lee
- Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Susan Zolla-Pazner
- 1] New York University School of Medicine, New York, New York, USA. [2] New York Veterans Affairs Harbor Healthcare System, New York, New York, USA
| | - Ulrich Baxa
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ernesto Freire
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Lawrence Shapiro
- 1] Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA. [2] Department of Biochemistry &Molecular Biophysics, Columbia University, New York, New York, USA
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | - James Arthos
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - James B Munro
- 1] Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James M Binley
- San Diego Biomedical Research Institute, San Diego, California, USA
| | - Adrian B McDermott
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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9
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Andoh K, Suenaga K, Sakaguchi M, Yamazaki K, Honda T. Decreased neutralizing antigenicity in IBV S1 protein expressed from mammalian cells. Virus Res 2015; 208:164-70. [PMID: 26113306 PMCID: PMC7114517 DOI: 10.1016/j.virusres.2015.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/17/2015] [Accepted: 06/18/2015] [Indexed: 11/06/2022]
Abstract
The recombinant infectious bronchitis virus (IBV) S1 protein was highly glycosylated and many complex N-glycans were attached on the surface. The recombinant S1 protein elicited antibodies against IBV S1 protein, but most of the antibodies could not neutralize IBV. The results indicated that the recombinant S1 may not be able to display neutralizing epitopes by losing native conformation or masking by glycan.
We evaluated the antigenicity of recombinant infectious bronchitis virus (IBV) S1 protein expressed in mammalian cells. Recombinant S1 was expressed as a secreted protein fused with a trimerization motif peptide, then purified using Ni Sepharose. The purified protein was analyzed by Western blotting, mixed with oil adjuvant, and administered to 29-day-old specific-pathogen-free chickens. Six weeks after immunization, anti-IBV neutralizing titer and anti-S1 ELISA titer were determined; immunized chickens then were inoculated with IBV via the trachea and ciliary activity was observed. Results showed that the recombinant S1 protein was highly glycosylated, and the neutralizing antigenicity of recombinant S1 protein was lower than that of inactivated virus. However, anti-S1 ELISA indicated that the recombinant S1 protein induced antibodies against S1. These results suggest that the recombinant S1 may retain non-neutralizing epitopes but have unnatural glycosylation pattern and conformation, resulting in lacking neutralizing conformational epitopes. In conclusion, the neutralizing antigenicity of recombinant S1 protein expressed from mammalian cells was decreased, and was not sufficient to induce neutralizing antibodies.
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Affiliation(s)
- Kiyohiko Andoh
- Animal Pharmaceuticals Division, The Chemo-Sero-Therapeutic Research Institute, 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan.
| | - Kiyotaka Suenaga
- R&D Division, The Chemo-Sero-Therapeutic Research Institute, Kikuchi Research Center, 1314-1 Kyokushikawabe, Kikuchi-shi, Kumamoto 869-1298, Japan
| | - Masashi Sakaguchi
- R&D Division, The Chemo-Sero-Therapeutic Research Institute, Kikuchi Research Center, 1314-1 Kyokushikawabe, Kikuchi-shi, Kumamoto 869-1298, Japan
| | - Kenichi Yamazaki
- Animal Pharmaceuticals Division, The Chemo-Sero-Therapeutic Research Institute, 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan
| | - Takashi Honda
- Animal Pharmaceuticals Division, The Chemo-Sero-Therapeutic Research Institute, 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan
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10
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Ward AB, Wilson IA. Insights into the trimeric HIV-1 envelope glycoprotein structure. Trends Biochem Sci 2015; 40:101-7. [PMID: 25600289 DOI: 10.1016/j.tibs.2014.12.006] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 01/16/2023]
Abstract
The HIV-1 envelope glycoprotein (Env) trimer is responsible for receptor recognition and viral fusion with CD4(+) T cells, and is the sole target for neutralizing antibodies. Thus, understanding its molecular architecture is of significant interest. However, the Env trimer has proved to be a challenging target for 3D structure determination. Recent electron microscopy (EM) and X-ray structures have at last enabled us to decipher the structural complexity and unique features of the Env trimer, and how it is recognized by an ever-expanding arsenal of potent broadly neutralizing antibodies. We describe our current knowledge of the Env trimer structure in the context of exciting recent developments in the identification and characterization of HIV broadly neutralizing antibodies.
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Affiliation(s)
- 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 and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, 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; International AIDS Vaccine Initiative Neutralizing Antibody Center and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, 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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11
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Hyperglycosylated stable core immunogens designed to present the CD4 binding site are preferentially recognized by broadly neutralizing antibodies. J Virol 2014; 88:14002-16. [PMID: 25253346 DOI: 10.1128/jvi.02614-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED The HIV-1 surface envelope glycoprotein (Env) trimer mediates entry into CD4(+) CCR5(+) host cells. Env possesses conserved antigenic determinants, such as the gp120 primary receptor CD4 binding site (CD4bs), a known neutralization target. Env also contains variable regions and protein surfaces occluded within the trimer that elicit nonneutralizing antibodies. Here we engineered additional N-linked glycans onto a cysteine-stabilized gp120 core (0G) deleted of its major variable regions to preferentially expose the conformationally fixed CD4bs. Three, 6, 7, and 10 new NXT/S glycan (G) motifs were engineered into 0G to encode 3G, 6G, 7G, and 10G cores. Following purification, most glycoproteins, except for 10G, were recognized by broadly neutralizing CD4bs-directed antibodies. Gel and glycan mass spectrometry confirmed that additional N-glycans were posttranslationally added to the redesigned cores. Binding kinetics revealed high-affinity recognition by seven broadly neutralizing CD4bs-directed antibodies and low to no binding by non-broadly neutralizing CD4bs-directed antibodies. Rabbits inoculated with the hyperglycosylated cores elicited IgM and IgG responses to each given protein that were similar in their neutralization characteristics to those elicited by parental 0G. Site-specific glycan masking effects were detected in the elicited sera, and the antisera competed with b12 for CD4bs-directed binding specificity. However, the core-elicited sera showed limited neutralization activity. Trimer priming or boosting of the core immunogens elicited tier 1-level neutralization that mapped to both the CD4bs and V3 and appeared to be trimer dependent. Fine mapping at the CD4bs indicated that conformational stabilization of the cores and addition of N-glycans altered the molecular surface of Env sites of vulnerability to neutralizing antibody, suggesting an explanation for why the elicited neutralization was not improved by this rational design strategy. IMPORTANCE Major obstacles to developing an effective HIV-1 vaccine include the variability of the envelope surface glycoproteins and its high-density glycan shield, generated by incorporation of host (human) glycosylation. HIV-1 does harbor highly conserved sites on the exposed envelope protein surface of gp120, one of which is the virus receptor (CD4) binding site. Several broadly neutralizing antibodies elicited from HIV patients do target this gp120 CD4 binding site (CD4bs); however, gp120 immunogens do not elicit broadly neutralizing antibodies. In this study, we targeted the CD4bs by conformational stabilization and additional glycan masking. We used the atomic-level structure to reengineer gp120 cores to preferentially present the cysteine-stabilized CD4bs and to mask (by glycan) nonneutralizing determinants. Importantly, glycan masking did successfully focus antibody responses to the CD4bs; however, the elicited CD4bs-directed antibodies did not neutralize HIV or bind to unmodified gp120, presumably due to the structure-guided modifications of the modified gp120 core.
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12
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Rabinovich S, Powell RLR, Lindsay RWB, Yuan M, Carpov A, Wilson A, Lopez M, Coleman JW, Wagner D, Sharma P, Kemelman M, Wright KJ, Seabrook JP, Arendt H, Martinez J, DeStefano J, Chiuchiolo MJ, Parks CL. A novel, live-attenuated vesicular stomatitis virus vector displaying conformationally intact, functional HIV-1 envelope trimers that elicits potent cellular and humoral responses in mice. PLoS One 2014; 9:e106597. [PMID: 25215861 PMCID: PMC4162551 DOI: 10.1371/journal.pone.0106597] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 08/03/2014] [Indexed: 01/09/2023] Open
Abstract
Though vaccination with live-attenuated SIV provides the greatest protection from progressive disease caused by SIV challenge in rhesus macaques, attenuated HIV presents safety concerns as a vaccine; therefore, live viral vectors carrying HIV immunogens must be considered. We have designed a replication-competent vesicular stomatitis virus (VSV) displaying immunogenic HIV-1 Env trimers and attenuating quantities of the native surface glycoprotein (G). The clade B Env immunogen is an Env-VSV G hybrid (EnvG) in which the transmembrane and cytoplasmic tail regions are derived from G. Relocation of the G gene to the 5'terminus of the genome and insertion of EnvG into the natural G position induced a ∼1 log reduction in surface G, significant growth attenuation compared to wild-type, and incorporation of abundant EnvG. Western blot analysis indicated that ∼75% of incorporated EnvG was a mature proteolytically processed form. Flow cytometry showed that surface EnvG bound various conformationally- and trimer-specific antibodies (Abs), and in-vitro growth assays on CD4+CCR5+ cells demonstrated EnvG functionality. Neither intranasal (IN) or intramuscular (IM) administration in mice induced any observable pathology and all regimens tested generated potent Env-specific ELISA titers of 10(4)-10(5), with an IM VSV prime/IN VSV boost regimen eliciting the highest binding and neutralizing Ab titers. Significant quantities of Env-specific CD4+ T cells were also detected, which were augmented as much as 70-fold by priming with IM electroporated plasmids encoding EnvG and IL-12. These data suggest that our novel vector can achieve balanced safety and immunogenicity and should be considered as an HIV vaccine platform.
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Affiliation(s)
- Svetlana Rabinovich
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
- Molecular and Cellular Biology Program, The School of Graduate Studies, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
| | - Rebecca L. R. Powell
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Ross W. B. Lindsay
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Maoli Yuan
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Alexei Carpov
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Aaron Wilson
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Mary Lopez
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - John W. Coleman
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Denise Wagner
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Palka Sharma
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Marina Kemelman
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Kevin J. Wright
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - John P. Seabrook
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Heather Arendt
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Jennifer Martinez
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Joanne DeStefano
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Maria J. Chiuchiolo
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
- Molecular and Cellular Biology Program, The School of Graduate Studies, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
| | - Christopher L. Parks
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
- Molecular and Cellular Biology Program, The School of Graduate Studies, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
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13
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Huang J, Kang BH, Pancera M, Lee JH, Tong T, Feng Y, Imamichi H, Georgiev IS, Chuang GY, Druz A, Doria-Rose NA, Laub L, Sliepen K, van Gils MJ, de la Peña AT, Derking R, Klasse PJ, Migueles SA, Bailer RT, Alam M, Pugach P, Haynes BF, Wyatt RT, Sanders RW, Binley JM, Ward AB, Mascola JR, Kwong PD, Connors M. Broad and potent HIV-1 neutralization by a human antibody that binds the gp41-gp120 interface. Nature 2014; 515:138-42. [PMID: 25186731 PMCID: PMC4224615 DOI: 10.1038/nature13601] [Citation(s) in RCA: 362] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 06/23/2014] [Indexed: 01/07/2023]
Abstract
The isolation of human monoclonal antibodies (mAbs) is providing important insights regarding the specificities that underlie broad neutralization of HIV-1 (reviewed in1). Here we report a broad and extremely potent HIV-specific mAb, termed 35O22, which binds novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with an IC50<50 μg/ml. The median IC50 of neutralized viruses was 0.033 μg/ml, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and a reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed it to bind a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current mAb-based approaches to immunotherapies, prophylaxis, and vaccine design.
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Affiliation(s)
- Jinghe Huang
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Byong H Kang
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Marie Pancera
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jeong Hyun Lee
- 1] The Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037, USA [2] International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Tommy Tong
- San Diego Biomedical Research Institute, San Diego, California 92121, USA
| | - Yu Feng
- International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Hiromi Imamichi
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ivelin S Georgiev
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Aliaksandr Druz
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Leo Laub
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kwinten Sliepen
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam 1100 DD, The Netherlands
| | - Marit J van Gils
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam 1100 DD, The Netherlands
| | - Alba Torrents de la Peña
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam 1100 DD, The Netherlands
| | - Ronald Derking
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam 1100 DD, The Netherlands
| | - Per-Johan Klasse
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065, USA
| | - Stephen A Migueles
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Robert T Bailer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Munir Alam
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Pavel Pugach
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Richard T Wyatt
- 1] The Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037, USA [2] International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Rogier W Sanders
- 1] Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam 1100 DD, The Netherlands [2] Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065, USA
| | - James M Binley
- San Diego Biomedical Research Institute, San Diego, California 92121, USA
| | - Andrew B Ward
- 1] The Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037, USA [2] International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - John R Mascola
- 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
| | - Mark Connors
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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14
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Yasmeen A, Ringe R, Derking R, Cupo A, Julien JP, Burton DR, Ward AB, Wilson IA, Sanders RW, Moore JP, Klasse PJ. Differential binding of neutralizing and non-neutralizing antibodies to native-like soluble HIV-1 Env trimers, uncleaved Env proteins, and monomeric subunits. Retrovirology 2014; 11:41. [PMID: 24884783 PMCID: PMC4067080 DOI: 10.1186/1742-4690-11-41] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/14/2014] [Indexed: 12/13/2022] Open
Abstract
Background The trimeric envelope glycoproteins (Env) on the surface of HIV-1 virions are the targets for neutralizing antibodies (NAbs). No candidate HIV-1 immunogen has yet induced potent, broadly active NAbs (bNAbs). Part of the explanation may be that previously tested Env proteins inadequately mimic the functional, native Env complex. Trimerization and the proteolytic processing of Env precursors into gp120 and gp41 profoundly alter antigenicity, but soluble cleaved trimers are too unstable to serve as immunogens. By introducing stabilizing mutations (SOSIP), we constructed soluble, cleaved Env trimers derived from the HIV-1 subtype A isolate BG505 that resemble native Env spikes on virions both structurally and antigenically. Results We used surface plasmon resonance (SPR) to quantify antibody binding to different forms of BG505 Env: the proteolytically cleaved SOSIP.664 trimers, cleaved gp120-gp41ECTO protomers, and gp120 monomers. Non-NAbs to the CD4-binding site bound only marginally to the trimers but equally well to gp120-gp41ECTO protomers and gp120 monomers, whereas the bNAb VRC01, directed to the CD4bs, bound to all three forms. In contrast, bNAbs to V1V2 glycan-dependent epitopes bound preferentially (PG9 and PG16) or exclusively (PGT145) to trimers. We also explored the antigenic consequences of three different features of SOSIP.664 gp140 trimers: the engineered inter-subunit disulfide bond, the trimer-stabilizing I559P change in gp41ECTO, and proteolytic cleavage at the gp120-gp41ECTO junction. Each of these three features incrementally promoted native-like trimer antigenicity. We compared Fab and IgG versions of bNAbs and validated a bivalent model of IgG binding. The NAbs showed widely divergent binding kinetics and degrees of binding to native-like BG505 SOSIP.664. High off-rate constants and low stoichiometric estimates of NAb binding were associated with large amounts of residual infectivity after NAb neutralization of the corresponding BG505.T332N pseudovirus. Conclusions The antigenicity and structural integrity of cleaved BG505 SOSIP.664 trimers render these proteins good mimics of functional Env spikes on virions. In contrast, uncleaved gp140s antigenically resemble individual gp120-gp41ECTO protomers and gp120 monomers, but not native trimers. Although NAb binding to functional trimers may thus be both necessary and sufficient for neutralization, the kinetics and stoichiometry of the interaction influence the neutralizing efficacy of individual NAbs.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Per Johan Klasse
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, USA.
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15
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Guo D, Shi X, Song D, Zhang L. Persistence of VRC01-resistant HIV-1 during antiretroviral therapy. SCIENCE CHINA-LIFE SCIENCES 2013; 57:88-96. [PMID: 24369354 DOI: 10.1007/s11427-013-4593-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 11/22/2013] [Indexed: 11/30/2022]
Abstract
VRC01, a broadly neutralizing monoclonal antibody (bnmAb), can neutralize a diverse array of HIV-1 isolates by mimicking CD4 binding to the envelope glycoprotein gp120. We have previously demonstrated the presence of VRC01-resistant strains in an HIV-1 infected patient during antiretroviral therapy. Here, we report follow-up studies of two subsequent samples from the same patient. With genetic and phenotypic analysis of over 70 full-length molecular clones of the HIV-1 envelope, we show that VRC01-resistant HIV-1 continued to exist and change in its proportion of the infecting virus during treatment with a highly active antiretroviral therapy. Consistent with our previous observation, the resistant phenotype was associated with a single asparagine residue at position 460 (N460), a potential N-linked glycosylation site in the V5 region. The persistence and continuing evolution of VRC01-resistant HIV-1 in vivo presents a great challenge to our future preventative and therapeutic interventions based on VRC01.
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Affiliation(s)
- Dongxing Guo
- Beijing Tropical Medicine Research Institute, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
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16
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Structural characterization of cleaved, soluble HIV-1 envelope glycoprotein trimers. J Virol 2013; 87:9865-72. [PMID: 23824817 DOI: 10.1128/jvi.01222-13] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection is a significant global public health problem for which development of an effective prophylactic vaccine remains a high scientific priority. Many concepts for a vaccine are focused on induction of appropriate titers of broadly neutralizing antibodies (bNAbs) against the viral envelope (Env) glycoproteins gp120 and gp41, but no immunogen has yet accomplished this goal in animals or humans. One approach to induction of bNAbs is to design soluble, trimeric mimics of the native viral Env trimer. Here, we describe structural studies by negative-stain electron microscopy of several variants of soluble Env trimers based on the KNH1144 subtype A sequence. These Env trimers are fully cleaved between the gp120 and gp41 components and stabilized by specific amino acid substitutions. We also illustrate the structural consequences of deletion of the V1/V2 and V3 variable loops from gp120 and the membrane-proximal external region (MPER) from gp41. All of these variants adopt a trimeric configuration that appropriately mimics native Env spikes, including the CD4 receptor-binding site and the epitope for the VRC PG04 bNAb. These cleaved, soluble trimer designs can be adapted for use with multiple different env genes for both vaccine and structural studies.
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17
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Kamanna K, Aneja R, Duffy C, Kubinski P, Moreira DR, Bailey LD, McFadden K, Schön A, Holmes A, Tuzer F, Contarino M, Freire E, Chaiken IM. Non-natural peptide triazole antagonists of HIV-1 envelope gp120. ChemMedChem 2013; 8:322-8. [PMID: 23239505 PMCID: PMC3810028 DOI: 10.1002/cmdc.201200422] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 11/08/2012] [Indexed: 11/06/2022]
Abstract
We investigated the derivation of non-natural peptide triazole dual receptor site antagonists of HIV-1 Env gp120 to establish a pathway for developing peptidomimetic antiviral agents. Previously we found that the peptide triazole HNG-156 [R-I-N-N-I-X-W-S-E-A-M-M-CONH(2), in which X=ferrocenyltriazole-Pro (FtP)] has nanomolar binding affinity to gp120, inhibits gp120 binding to CD4 and the co-receptor surrogate mAb 17b, and has potent antiviral activity in cell infection assays. Furthermore, truncated variants of HNG-156, typified by UM-24 (Cit-N-N-I-X-W-S-CONH(2)) and containing the critical central stereospecific (L)X-(L)W cluster, retain the functional characteristics of the parent peptide triazole. In the current work, we examined the possibility of replacing natural with unnatural residue components in UM-24 to the greatest extent possible. The analogue with the critical "hot spot" residue Trp 6 replaced with L-3-benzothienylalanine (Bta) (KR-41), as well as a completely non-natural analogue containing D-amino acid substitutions outside the central cluster (KR-42, (D)Cit-(D)N-(D)N-(D)I-X-Bta-(D)S-CONH(2)), retained the dual receptor site antagonism/antiviral activity signature. The results define differential functional roles of subdomains within the peptide triazole and provide a structural basis for the design of metabolically stable peptidomimetic inhibitors of HIV-1 Env gp120.
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Affiliation(s)
- Kantharaju Kamanna
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Rachna Aneja
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Caitlin Duffy
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Pamela Kubinski
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Diogo Rodrigo Moreira
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Lauren D Bailey
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Karyn McFadden
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Arne Schön
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218 (USA)
| | - Andrew Holmes
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Ferit Tuzer
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Mark Contarino
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
| | - Ernesto Freire
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218 (USA)
| | - Irwin M Chaiken
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245N, 15 Street, New College Building, Room 11302, Philadelphia, PA, 19102 (USA)
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18
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Tuzer F, Madani N, Kamanna K, Zentner I, LaLonde J, Holmes A, Upton E, Rajagopal S, McFadden K, Contarino M, Sodroski J, Chaiken I. HIV-1 Env gp120 structural determinants for peptide triazole dual receptor site antagonism. Proteins 2012; 81:271-90. [PMID: 23011758 DOI: 10.1002/prot.24184] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 08/18/2012] [Accepted: 09/03/2012] [Indexed: 11/09/2022]
Abstract
Despite advances in HIV therapy, viral resistance and side-effects with current drug regimens require targeting new components of the virus. Dual antagonist peptide triazoles (PT) are a novel class of HIV-1 inhibitors that specifically target the gp120 component of the viral spike and inhibit its interaction with both of its cell surface protein ligands, namely the initial receptor CD4 and the co-receptor (CCR5/CXCR4), thus preventing viral entry. Following an initial survey of 19 gp120 alanine mutants by ELISA, we screened 11 mutants for their importance in binding to, and inhibition by the PT KR21 using surface plasmon resonance. Key mutants were purified and tested for their effects on the peptide's affinity and its ability to inhibit binding of CD4 and the co-receptor surrogate mAb 17b. Effects of the mutations on KR21 viral neutralization were measured by single-round cell infection assays. Two mutations, D474A and T257A, caused large-scale loss of KR21 binding, as well as losses in both CD4/17b and viral inhibition by KR21. A set of other Ala mutants revealed more moderate losses in direct binding affinity and inhibition sensitivity to KR21. The cluster of sensitive residues defines a PT functional epitope. This site is in a conserved region of gp120 that overlaps the CD4 binding site and is distant from the co-receptor/17b binding site, suggesting an allosteric mode of inhibition for the latter. The arrangement and sequence conservation of the residues in the functional epitope explain the breadth of antiviral activity, and improve the potential for rational inhibitor development.
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Affiliation(s)
- Ferit Tuzer
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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Guo D, Shi X, Arledge KC, Song D, Jiang L, Fu L, Gong X, Zhang S, Wang X, Zhang L. A single residue within the V5 region of HIV-1 envelope facilitates viral escape from the broadly neutralizing monoclonal antibody VRC01. J Biol Chem 2012; 287:43170-9. [PMID: 23100255 DOI: 10.1074/jbc.m112.399402] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
VRC01, a broadly neutralizing monoclonal antibody, is capable of neutralizing a diverse array of HIV-1 isolates by mimicking CD4 binding with the envelope glycoprotein gp120. Nonetheless, resistant strains have been identified. Here, we examined two genetically related and two unrelated envelope clones, derived from CRF08_BC-infected patients, with distinct VRC01 neutralization profiles. A total of 22 chimeric envelope clones was generated by interchanging the loop D and/or V5 regions between the original envelopes or by single alanine substitutions within each region. Analysis of pseudoviruses built from these mutant envelopes showed that interchanging the V5 region between the genetically related or unrelated clones completely swapped their VRC01 sensitivity profiles. Mutagenesis analysis revealed that the asparagine residue at position 460 (Asn-460), a potential N-linked glycosylation site in the V5 region, is a key factor for observed resistance in these strains, which is further supported by our structural modeling. Moreover, changes in resistance were found to positively correlate with deviations in VRC01 binding affinity. Overall, our study indicates that Asn-460 in the V5 region is a critical determinant of sensitivity to VRC01 specifically in these viral strains. The long side chain of Asn-460, and potential glycosylation, may create steric hindrance that lowers binding affinity, thereby increasing resistance to VRC01 neutralization.
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Affiliation(s)
- Dongxing Guo
- AIDS Research Center, MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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20
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Kong L, Sattentau QJ. Antigenicity and Immunogenicity in HIV-1 Antibody-Based Vaccine Design. JOURNAL OF AIDS & CLINICAL RESEARCH 2012; S8:3. [PMID: 23227445 PMCID: PMC3515071 DOI: 10.4172/2155-6113] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neutralizing antibodies can protect from infection by immunodeficiency viruses. However, the induction by active vaccination of antibodies that can potently neutralize a broad range of circulating virus strains is a goal not yet achieved, despite more than 2 decades of research. Here we review progress made in the field, from early empirical studies to today's rational structure-based vaccine antigen design. We discuss the existence of broadly neutralizing antibodies, their implications for epitope discovery and recent progress made in antigen design. Finally, we consider the relationship between antigenicity and immunogenicity for B cell recognition and antibody production, a major hurdle for rational vaccine design to overcome.
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Affiliation(s)
- Leopold Kong
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Quentin J Sattentau
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
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21
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Lula I, De Sousa FB, Denadai ÂM, de Lima GF, Duarte HA, dos Mares Guia TR, Faljoni-Alario A, Santoro MM, de Camargo AC, dos Santos RA, Sinisterra RD. Interaction between bradykinin potentiating nonapeptide (BPP9a) and β-cyclodextrin: A structural and thermodynamic study. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012. [DOI: 10.1016/j.msec.2011.10.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Saha P, Bhattacharyya S, Kesavardhana S, Miranda ER, Ali PSS, Sharma D, Varadarajan R. Designed Cyclic Permutants of HIV-1 gp120: Implications for Envelope Trimer Structure and Immunogen Design. Biochemistry 2012; 51:1836-47. [DOI: 10.1021/bi300003v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Piyali Saha
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | | | - Sannula Kesavardhana
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | | | - P. Shaik Syed Ali
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Deepak Sharma
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Raghavan Varadarajan
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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23
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Denadai ÂM, de Oliveira AM, Daniel IM, Carneiro LA, Ribeiro KC, Beraldo HDO, da Costa KJ, da Cunha VC, Cortés ME, Sinisterra RD. Chlorhexidine/losartan ionic pair binding and its nanoprecipitation: physico-chemical characterisation and antimicrobial activity. Supramol Chem 2011. [DOI: 10.1080/10610278.2011.642101] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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24
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Feng Y, McKee K, Tran K, O'Dell S, Schmidt SD, Phogat A, Forsell MN, Karlsson Hedestam GB, Mascola JR, Wyatt RT. Biochemically defined HIV-1 envelope glycoprotein variant immunogens display differential binding and neutralizing specificities to the CD4-binding site. J Biol Chem 2011; 287:5673-86. [PMID: 22167180 DOI: 10.1074/jbc.m111.317776] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HIV-1 gp120 binds the primary receptor CD4. Recently, a plethora of broadly neutralizing antibodies to the gp120 CD4-binding site (CD4bs) validated this region as a target for immunogen design. Here, we asked if modified HIV-1 envelope glycoproteins (Env) designed to increase CD4 recognition might improve recognition by CD4bs neutralizing antibodies and more efficiently elicit such reactivities. We also asked if CD4bs stabilization, coupled with altering the Env format (monomer to trimer or cross-clade), might better elicit neutralizing antibodies by focusing the immune response on the functionally conserved CD4bs. We produced monomeric and trimeric Envs stabilized by mutations within the gp120 CD4bs cavity (pocket-filling; PF2) or by appending heterologous trimerization motifs to soluble Env ectodomains (gp120/gp140). Recombinant glycoproteins were purified to relative homogeneity, and ligand binding properties were analyzed by ELISA, surface plasmon resonance, and isothermal titration microcalorimetry. In some formats, the PF2 substitutions increased CD4 affinity, and importantly, PF2-containing proteins were better recognized by the broadly neutralizing CD4bs mAbs, VRC01 and VRC-PG04. Based on this analysis, we immunized selected Env variants into rabbits using heterologous or homologous regimens. Analysis of the sera revealed that homologous inoculation of the PF2-containing, variable region-deleted YU2 gp120 trimers (ΔV123/PF2-GCN4) more rapidly elicited CD4bs-directed neutralizing antibodies compared with other regimens, whereas homologous trimers elicited increased neutralization potency, mapping predominantly to the gp120 third major variable region (V3). These results suggest that some engineered Env proteins may more efficiently direct responses toward the conserved CD4bs and be valuable to elicit antibodies of greater neutralizing capacity.
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Affiliation(s)
- Yu Feng
- IAVI Neutralizing Antibody Center, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037, USA
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Melchers M, Matthews K, de Vries RP, Eggink D, van Montfort T, Bontjer I, van de Sandt C, David K, Berkhout B, Moore JP, Sanders RW. A stabilized HIV-1 envelope glycoprotein trimer fused to CD40 ligand targets and activates dendritic cells. Retrovirology 2011; 8:48. [PMID: 21689404 PMCID: PMC3141652 DOI: 10.1186/1742-4690-8-48] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 06/20/2011] [Indexed: 12/22/2022] Open
Abstract
Background One reason why subunit protein and DNA vaccines are often less immunogenic than live-attenuated and whole-inactivated virus vaccines is that they lack the co-stimulatory signals provided by various components of the more complex vaccines. The HIV-1 envelope glycoprotein complex (Env) is no exception to this rule. Other factors that limit the induction of neutralizing antibodies against HIV-1 lie in the structure and instability of Env. We have previously stabilized soluble trimeric mimics of Env by introducing a disulfide bond between gp120 and gp41 and adding a trimer stabilizing mutation in gp41 (SOSIP.R6 gp140). Results We further stabilized the SOSIP.R6 gp140 using a GCN4-based isoleucine zipper motif, creating SOSIP.R6-IZ gp140. In order to target SOSIP.R6-IZ to immune cells, including dendritic cells, while at the same time activating these cells, we fused SOSIP.R6-IZ to the active domain of CD40 ligand (CD40L), which may serve as a 'cis-adjuvant'. The Env component of the SOSIP.R6-IZ-CD40L fusion construct bound to CD4 and neutralizing antibodies, while the CD40L moiety interacted with CD40. Furthermore, the chimeric molecule was able to signal efficiently through CD40 and induce maturation of human dendritic cells. Dendritic cells secreted IL-6, IL-10 and IL-12 in response to stimulation by SOSIP.R6-IZ-CD40L and were able to activate naïve T cells. Conclusions Chimeric HIV-1 gp140 - CD40L trimers can target and activate dendritic cells. Targeting and activating immune cells using CD40L and other 'cis-adjuvants' may improve subunit protein vaccine immunogenicity for HIV-1 and other infectious diseases.
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Affiliation(s)
- Mark Melchers
- Laboratory of Experimental Virology, Department of Medical Microbiology Center for Infection and Immunity Amsterdam, Netherlands
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Mattiacio J, Walter S, Brewer M, Domm W, Friedman AE, Dewhurst S. Dense display of HIV-1 envelope spikes on the lambda phage scaffold does not result in the generation of improved antibody responses to HIV-1 Env. Vaccine 2011; 29:2637-47. [PMID: 21310193 DOI: 10.1016/j.vaccine.2011.01.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 01/01/2011] [Accepted: 01/09/2011] [Indexed: 10/18/2022]
Abstract
The generation of strong, virus-neutralizing antibody responses to the HIV-1 envelope spike (Env) is a major goal in HIV-1 vaccine research. To try to enhance the Env-specific response, we displayed oligomeric gp140 on a virus-like scaffold provided by the lambda phage capsid. To do this, an in vitro complementation system was used to "decorate" phage particles with glycosylated, mammalian cell-derived envelope oligomers. We compared the immune response to lambda phage particles displaying HIV-1 Env to that elicited by soluble oligomeric gp140 in rabbits. Env-binding antibody titers were higher in animals that received oligomeric gp140 as compared to Env decorated phage particles, as were virus neutralizing antibody responses. The Env decorated phage particles were, however, able to efficiently boost a protein-primed humoral response to levels equivalent to those elicited by high-dose adjuvanted Env oligomers. These results show that display of HIV-1 envelope spikes on the bacteriophage lambda capsid does not result in an improved, Env-specific humoral immune response.
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Affiliation(s)
- Jonelle Mattiacio
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
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Abstract
We have used cryoelectron tomography of vitreous-ice-embedded HIV-1 virions to compare the envelope (Env) spikes of a wild-type strain with those of a mutant strain in which the V1/V2 loop has been deleted. Deletion of V1/V2 results in a spike with far more structural heterogeneity than is observed in the wild type, likely reflecting greatly enhanced gp120 protomer flexibility. A major difference between the two forms is a pronounced loss of mass from the "peak" of the native Env spike. The apparent loss of contact among three gp120 protomers likely accounts for the more open structure, heterogeneity in configuration, and previous observations that broadly neutralizing epitopes and reactive sites on other structural elements are more exposed in such constructs.
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Bontjer I, Melchers M, Eggink D, David K, Moore JP, Berkhout B, Sanders RW. Stabilized HIV-1 envelope glycoprotein trimers lacking the V1V2 domain, obtained by virus evolution. J Biol Chem 2010; 285:36456-70. [PMID: 20826824 DOI: 10.1074/jbc.m110.156588] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The envelope glycoproteins (Env) are the focus of HIV-1 vaccine development strategies based on the induction of humoral immunity, but the mechanisms the virus has evolved to limit the induction and binding of neutralizing antibodies (NAbs) constitute substantial obstacles. Conserved neutralization epitopes are shielded by variable regions and carbohydrates, so one strategy to increase their exposure and, it is hoped, their immunogenicity is to delete the overlying variable loops. However, deleting the variable regions from Env trimers can be problematic, because hydrophobic patches that are normally solvent-inaccessible now become exposed, causing protein misfolding or aggregation, for example. Here, we describe the construction and characterization of recombinant gp140 trimers lacking variable domains 1 and 2 (ΔV1V2). The design of the trimers was guided by HIV-1 evolution studies that identified compensatory changes in V1V2-deleted but functional Env proteins (Bontjer, I., Land, A., Eggink, D., Verkade, E., Tuin, K., Baldwin, C., Pollakis, G., Paxton, W. A., Braakman, I., Berkhout, B., and Sanders, R. W. (2009) J. Virol. 83, 368-383). We now show that specific compensatory changes improved the function of ΔV1V2 Env proteins and hence HIV-1 replication. The changes acted by reducing the exposure of a hydrophobic surface either by replacing a hydrophobic residue with a hydrophilic one or by covering the surface with a glycan. The compensatory changes allowed the efficient expression of well folded, soluble gp140 trimers derived from various HIV-1 isolates. The evolved ΔV1V2 Env viruses were extremely sensitive to NAbs, indicating that neutralization epitopes are well exposed, which was confirmed by studies of NAb binding to the soluble ΔV1V2 gp140 trimers. These evolved ΔV1V2 trimers could be useful reagents for immunogenicity and structural studies.
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Affiliation(s)
- Ilja Bontjer
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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Weldon WC, Wang BZ, Martin MP, Koutsonanos DG, Skountzou I, Compans RW. Enhanced immunogenicity of stabilized trimeric soluble influenza hemagglutinin. PLoS One 2010; 5. [PMID: 20824188 PMCID: PMC2931692 DOI: 10.1371/journal.pone.0012466] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 07/30/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The recent swine-origin H1N1 pandemic illustrates the need to develop improved procedures for rapid production of influenza vaccines. One alternative to the current egg-based manufacture of influenza vaccine is to produce a hemagglutinin (HA) subunit vaccine using a recombinant expression system with the potential for high protein yields, ease of cloning new antigenic variants, and an established safety record in humans. METHODOLOGY/PRINCIPAL FINDINGS We generated a soluble HA (sHA), derived from the H3N2 virus A/Aichi/2/68, modified at the C-terminus with a GCN4pII trimerization repeat to stabilize the native trimeric structure of HA. When expressed in the baculovirus system, the modified sHA formed native trimers. In contrast, the unmodified sHA was found to present epitopes recognized by a low-pH conformation specific monoclonal antibody. We found that mice primed and boosted with 3 microg of trimeric sHA in the absence of adjuvants had significantly higher IgG and HAI titers than mice that received the unmodified sHA. This correlated with an increased survival and reduced body weight loss following lethal challenge with mouse-adapted A/Aichi/2/68 virus. In addition, mice receiving a single vaccination of the trimeric sHA in the absence of adjuvants had improved survival and body weight loss compared to mice vaccinated with the unmodified sHA. CONCLUSIONS/SIGNIFICANCE Our data indicate that the recombinant trimeric sHA presents native trimeric epitopes while the unmodified sHA presents epitopes not exposed in the native HA molecule. The epitopes presented in the unmodified sHA constitute a "silent face" which may skew the antibody response to epitopes not accessible in live virus at neutral pH. The results demonstrate that the trimeric sHA is a more effective influenza vaccine candidate and emphasize the importance of structure-based antigen design in improving recombinant HA vaccines.
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Affiliation(s)
- William C. Weldon
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Bao-Zhong Wang
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Maria P. Martin
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Dimitrios G. Koutsonanos
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Ioanna Skountzou
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Richard W. Compans
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail:
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Alterations in the immunogenic properties of soluble trimeric human immunodeficiency virus type 1 envelope proteins induced by deletion or heterologous substitutions of the V1 loop. J Virol 2010; 84:9932-46. [PMID: 20660181 DOI: 10.1128/jvi.00868-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 gp140 envelope immunogens express conserved epitopes that are targeted by broadly cross-reactive neutralizing antibodies, but they fail to elicit similar antibodies upon immunization. The poor immunogenicity of conserved epitopes on gp140 could be linked to the high immunogenicity of variable Env regions on such constructs. Previous studies have shown that the first hypervariable region (V1 loop) is immunogenic on soluble gp140s but elicits type-specific antibodies. To address issues related to the high immunogenicity of the V1 loop, two conceptually opposite approaches were tested. In the first approach, we eliminated the V1 loop from our gp140 construct and examined how V1 deletion altered the immunogenic properties of other Env regions. In the second approach, we took advantage of the high immunogenicity of the V1 loop and engrafted four diverse V1 loops onto a common gp140 Env "scaffold." These four scaffolds were used as a cocktail of immunogens to elicit diverse anti-V1 antibodies, under the hypothesis that eliciting diverse anti-V1 antibodies would expand the neutralizing breadth of immune sera. Our study indicates that three of four heterologous V1 loops were immunogenic on the common Env backbone "scaffold," but heterologous anti-V1 neutralizing responses were observed in only one case. Both types of V1 modification dampened the immunogenicity of the V3 loop, differentially altered the immunogenicity of the transmembrane gp41 subunit, and altered the relative immunogenicities of unknown Env regions, including potentially the CD4-binding site (CD4-bs) and trimer-specific targets, which elicited cross-reactive neutralizing antibodies but of limited breadth.
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Abstract
Licensed vaccines against viral diseases generate antibodies that neutralize the infecting virus and protect against infection or disease. Similarly, an effective vaccine against HIV-1 will likely need to induce antibodies that prevent initial infection of host cells or that limit early events of viral dissemination. Such antibodies must target the surface envelope glycoproteins of HIV-1, which are highly variable in sequence and structure. The first subunit vaccines to enter clinical trails were safe and immunogenic but unable to elicit antibodies that neutralized most circulating strains of HIV-1. However, potent virus neutralizing antibodies (NAbs) can develop during the course of HIV-1 infection, and this is the type of antibody response that researchers seek to generate with a vaccine. Thus, current vaccine design efforts have focused on a more detailed understanding of these broadly neutralizing antibodies and their epitopes to inform the design of improved vaccines.
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Affiliation(s)
- John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Denadai ÂM, Santoro MM, Texeira AV, Sinisterra RD. New insights regarding the cyclodextrin/AAS self-assembly: A molar ratio dependent system. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2010. [DOI: 10.1016/j.msec.2009.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Eggink D, Melchers M, Wuhrer M, van Montfort T, Dey AK, Naaijkens BA, David KB, Le Douce V, Deelder AM, Kang K, Olson WC, Berkhout B, Hokke CH, Moore JP, Sanders RW. Lack of complex N-glycans on HIV-1 envelope glycoproteins preserves protein conformation and entry function. Virology 2010; 401:236-47. [PMID: 20304457 DOI: 10.1016/j.virol.2010.02.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 12/23/2009] [Accepted: 02/13/2010] [Indexed: 10/19/2022]
Abstract
The HIV-1 envelope glycoprotein complex (Env) is the focus of vaccine development aimed at eliciting humoral immunity. Env's extensive and heterogeneous N-linked glycosylation affects folding, binding to lectin receptors, antigenicity and immunogenicity. We characterized recombinant Env proteins and virus particles produced in mammalian cells that lack N-acetylglucosaminyltransferase I (GnTI), an enzyme necessary for the conversion of oligomannose N-glycans to complex N-glycans. Carbohydrate analyses revealed that trimeric Env produced in GnTI(-/-) cells contained exclusively oligomannose N-glycans, with incompletely trimmed oligomannose glycans predominating. The folding and conformation of Env proteins was little affected by the manipulation of the glycosylation. Viruses produced in GnTI(-/-) cells were infectious, indicating that the conversion to complex glycans is not necessary for Env entry function, although virus binding to the C-type lectin DC-SIGN was enhanced. Manipulating Env's N-glycosylation may be useful for structural and functional studies and for vaccine design.
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Affiliation(s)
- Dirk Eggink
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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Abstract
PURPOSE OF REVIEW We summarize and discuss recent developments regarding the immunogenicity of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) oligomers, focusing, for the most part, on trimeric, recombinant protein immunogens. RECENT FINDINGS The three-dimensional cryo-electron tomography images of the HIV-1 Env trimeric spike, coupled with previous data demonstrating the impact on envelope glycoprotein (gp120)-transmembrane glycoprotein (gp41) cleavage of the architecture of the Env trimers, provide exciting information that may lead to new avenues for novel immunogen design. Through new processes to map region-specific anti-Env antibodies present in immune serum, it is now possible to define antibody specificities against conformationally sensitive surfaces of Env. A number of strategies designed to counteract the immunodominance of the HIV-1 Env variable regions were attempted, and a recent study demonstrates that immunization with Env trimers provides sterilizing protection against mucosal challenge with virus. Importantly, protection against the challenge virus was associated with in-vitro HIV-1 neutralization titers. SUMMARY Several studies within the past 18 months provide exciting structural information and the development of tools that have the potential to improve Env trimer design and the analysis of trimer immunogenicity studies. The ability to predict protection against a challenge virus through an in-vitro neutralization screen may be very helpful for evaluation of immunogens to move forward into clinical trials.
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Abstract
PURPOSE OF REVIEW HIV-1 neutralizing antibodies are directed to the Envelope glycoprotein trimer on the surface of the virion and block entry into target cells in vitro. During infection, closely related but distinct variants arise in infected individuals, and the interplay of Envelope and neutralizing antibodies is a dynamic process. Vaccines that generate neutralizing antibodies and drugs that inhibit entry must address the issue of variation of subtypes worldwide. The purpose of this review is to summarize major advances in the neutralizing antibody field published during 2005 and early 2006. RECENT FINDINGS The main themes that are covered in this review include new findings in the development of neutralizing antibodies during natural and experimental infection, characterization of monoclonal antibodies with neutralizing activity, Envelope structural data, the development of novel Envelope constructs, and novel approaches designed to generate neutralizing antibodies by vaccination. SUMMARY Advances leading to a better understanding of the structure of the Envelope and the character of neutralizing antibodies that develop during the course of infection have provided important clues to guide the design of better immunogens and drugs to block attachment. These findings have implications for prophylactic and therapeutic vaccine approaches, drugs, and antibody-based therapies to reduce HIV transmission.
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Vaine M, Lu S, Wang S. Progress on the induction of neutralizing antibodies against HIV type 1 (HIV-1). BioDrugs 2009; 23:137-53. [PMID: 19627166 DOI: 10.2165/00063030-200923030-00001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Infection with HIV type 1 (HIV-1), the causative agent of AIDS, is one of the most catastrophic pandemics to affect human healthcare in the latter 20th century. The best hope of controlling this pandemic is the development of a successful prophylactic vaccine. However, to date, this goal has proven to be exceptionally elusive. The recent failure of an experimental vaccine in a phase IIb study, named the STEP trial, intended solely to elicit cell-mediated immune responses against HIV-1, has highlighted the need for a balanced immune response consisting of not only cellular immunity but also a broad and potent humoral antibody response that can prevent infection with HIV-1. This article reviews the efforts made up to this point to elicit such antibody responses, especially with regard to the use of a DNA prime-protein boost regimen, which has been proven to be a highly effective platform for the induction of neutralizing antibodies in both animal and early-phase human studies.
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Affiliation(s)
- Michael Vaine
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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Dosenovic P, Chakrabarti B, Soldemo M, Douagi I, Forsell MNE, Li Y, Phogat A, Paulie S, Hoxie J, Wyatt RT, Karlsson Hedestam GB. Selective expansion of HIV-1 envelope glycoprotein-specific B cell subsets recognizing distinct structural elements following immunization. THE JOURNAL OF IMMUNOLOGY 2009; 183:3373-82. [PMID: 19696434 DOI: 10.4049/jimmunol.0900407] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The HIV-1 envelope glycoprotein (Env) functional spike has evolved multiple immune evasion strategies, and only a few broadly neutralizing determinants on the assembled spike are accessible to Abs. Serological studies, based upon Ab binding and neutralization activity in vitro, suggest that vaccination with current Env-based immunogens predominantly elicits Abs that bind nonneutralizing or strain-restricted neutralizing epitopes. However, the fractional specificities of the polyclonal mixture of Abs present in serum, especially those directed to conformational Env epitopes, are often difficult to determine. Furthermore, serological analyses do not provide information regarding how repeated Ag inoculation impacts the expansion and maintenance of Env-specific B cell subpopulations. Therefore, we developed a highly sensitive Env-specific B cell ELISPOT system, which allows the enumeration of Ab-secreting cells (ASC) from diverse anatomical compartments directed against different structural determinants of Env. In this study, we use this system to examine the evolution of B cell responses in mice immunized with engineered Env trimers in adjuvant. We demonstrate that the relative proportion of ASC specific for defined structural elements of Env is altered significantly by homologous booster immunizations. This results in the selective expansion of ASC directed against the variable regions of Env. We suggest that the B cell specificity and compartment analysis described in this study are important complements to serological mapping studies for the examination of B cell responses against subspecificities of a variety of immunogens.
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Affiliation(s)
- Pia Dosenovic
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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Structure-based stabilization of HIV-1 gp120 enhances humoral immune responses to the induced co-receptor binding site. PLoS Pathog 2009; 5:e1000445. [PMID: 19478876 PMCID: PMC2680979 DOI: 10.1371/journal.ppat.1000445] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Accepted: 04/25/2009] [Indexed: 11/23/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) exterior envelope glycoprotein, gp120, possesses conserved binding sites for interaction with the primary virus receptor, CD4, and also for the co-receptor, generally CCR5. Although gp120 is a major target for virus-specific neutralizing antibodies, the gp120 variable elements and its malleable nature contribute to evasion of effective host-neutralizing antibodies. To understand the conformational character and immunogenicity of the gp120 receptor binding sites as potential vaccine targets, we introduced structure-based modifications to stabilize gp120 core proteins (deleted of the gp120 major variable regions) into the conformation recognized by both receptors. Thermodynamic analysis of the re-engineered core with selected ligands revealed significant stabilization of the receptor-binding regions. Stabilization of the co-receptor-binding region was associated with a marked increase in on-rate of ligand binding to this site as determined by surface plasmon resonance. Rabbit immunization studies showed that the conformational stabilization of core proteins, along with increased ligand affinity, was associated with strikingly enhanced humoral immune responses against the co-receptor-binding site. These results demonstrate that structure-based approaches can be exploited to stabilize a conformational site in a large functional protein to enhance immunogenic responses specific for that region. Vaccination is an effective means to control worldwide human diseases caused by viruses and other pathogens. Most viral vaccines work by inducing the immune system to generate neutralizing antibodies. The human immunodeficiency virus (HIV) continues to cause huge tolls in terms of human death and disease. The generation of neutralizing antibodies against HIV remains a key but elusive goal for the development of an effective vaccine. Here, we describe a novel approach that uses atomic-level structures of the HIV surface protein, gp120, together with extensive biophysical analysis of this protein, to design modified vaccine candidates. Immunization with these modified gp120 proteins revealed a new relationship between structure-guided protein stability and the efficient elicitation of antibodies against the highly conserved co-receptor binding site of HIV. These data demonstrate the potential for using the design principles established here to develop improved antibody-generating HIV vaccines and for vaccines against other pathogens.
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Gopi H, Cocklin S, Pirrone V, McFadden K, Tuzer F, Zentner I, Ajith S, Baxter S, Jawanda N, Krebs FC, Chaiken IM. Introducing metallocene into a triazole peptide conjugate reduces its off-rate and enhances its affinity and antiviral potency for HIV-1 gp120. J Mol Recognit 2009; 22:169-74. [PMID: 18498083 DOI: 10.1002/jmr.892] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this work, we identified a high affinity and potency metallocene-containing triazole peptide conjugate that suppresses the interactions of HIV-1 envelope gp120 at both its CD4 and co-receptor binding sites. The ferrocene-peptide conjugate, HNG-156, was formed by an on-resin copper-catalysed [2+3] cycloaddition reaction. Surface plasmon resonance interaction analysis revealed that, compared to a previously reported phenyl-containing triazole conjugate HNG-105 (105), peptide 156 had a higher direct binding affinity for several subtypes of HIV-1 gp120 due mainly to the decreased dissociation rate of the conjugate-gp120 complex. The ferrocene triazole conjugate bound to gp120 of both clade A (92UG037-08) and clade B (YU-2 and SF162) virus subtypes with nanomolar KD in direct binding and inhibited the binding of gp120 to soluble CD4 and to antibodies that bind to HIV-1YU-2 gp120 at both the CD4 binding site and CD4-induced binding sites. HNG-156 showed a close-to nanomolar IC50 for inhibiting cell infection by HIV-1BaL whole virus. The dual receptor site antagonist activity and potency of HNG-156 make it a promising viral envelope inhibitor lead for developing anti-HIV-1 treatments.
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Affiliation(s)
- Hosahudya Gopi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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Doria-Rose NA, Klein RM, Manion MM, O'Dell S, Phogat A, Chakrabarti B, Hallahan CW, Migueles SA, Wrammert J, Ahmed R, Nason M, Wyatt RT, Mascola JR, Connors M. Frequency and phenotype of human immunodeficiency virus envelope-specific B cells from patients with broadly cross-neutralizing antibodies. J Virol 2009; 83:188-99. [PMID: 18922865 PMCID: PMC2612342 DOI: 10.1128/jvi.01583-08] [Citation(s) in RCA: 258] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 10/08/2008] [Indexed: 12/28/2022] Open
Abstract
Induction of broadly cross-reactive neutralizing antibodies (NAb) is an important goal for a prophylactic human immunodeficiency virus type 1 (HIV-1) vaccine. Some HIV-infected patients make a NAb response that reacts with diverse strains of HIV-1, but most candidate vaccines have induced NAb only against a subset of highly sensitive isolates. To better understand the nature of broad NAb responses that arise during natural infection, we screened patients for sera able to neutralize diverse HIV strains and explored the frequency and phenotype of their peripheral Envelope-specific B cells. We screened 113 HIV-infected patients of various clinical statuses for the prevalence of broad NAb. Sera able to neutralize at least four of five viral isolates were found in over one-third of progressors and slow progressors, but much less frequently in aviremic long-term nonprogressors. Most Env-specific antibody-secreting B cells were CD27(hi) CD38(hi) plasmablasts, and the total plasmablast frequency was higher in HIV-infected patients than in uninfected donors. We found that 0.0031% of B cells and 0.047% of plasmablasts secreted Env-specific immunoglobulin G (IgG) in an enzyme-linked immunospot (ELISPOT) assay. We developed a novel staining protocol to label HIV-specific B cells with Env gp140 protein. A total of 0.09% of B cells were found to be Env-specific by this method, a frequency far higher than that indicated by ELISPOT assay. gp140-labeled B cells were predominantly CD27(+) and surface IgG(+). These data describe the breadth and titer of serum NAb and the frequency and phenotype of HIV-specific B cells in a cohort of patients with broad cross-neutralizing antibody responses that are potential goals for vaccines for HIV.
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Affiliation(s)
- Nicole A Doria-Rose
- LIR, NIAID, National Institutes of Health, Bldg. 10, Rm. 7N246, 10 Center Dr., Bethesda, MD 20892, USA
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41
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Crooks ET, Jiang P, Franti M, Wong S, Zwick MB, Hoxie JA, Robinson JE, Moore PL, Binley JM. Relationship of HIV-1 and SIV envelope glycoprotein trimer occupation and neutralization. Virology 2008; 377:364-78. [PMID: 18539308 DOI: 10.1016/j.virol.2008.04.045] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 03/21/2008] [Accepted: 04/24/2008] [Indexed: 11/26/2022]
Abstract
Insights into the process of HIV-1 neutralization may assist rational vaccine design. Here, we compared antibody neutralization against the JR-FL primary isolate and trimer binding affinities judged by native PAGE. Monovalent Fab-trimer binding and neutralization showed a direct quantitative relationship, implying that neutralization begins as each trimer is occupied by one antibody. At saturation, three Fab or soluble CD4 molecules engaged each trimer. In contrast, a maximum of one soluble CD4 molecule bound to functional SIV trimers with a truncated a gp41 tail. Remarkably, soluble CD4 was found to trigger dramatic enhancement of this virus. Unlike Fabs, a quantitative correlation between JR-FL trimer binding and neutralization was unclear for some, but not all IgGs, as neutralization was markedly increased, but trimer affinity was largely unchanged. In addition, only one molecule of certain gp41-specific IgGs appeared to be able to bind each trimer. We discuss the implications of these findings in weighing the relative contributions of size, multivalent binding and other possible effects of IgGs to explain their increased potency.
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Affiliation(s)
- Emma T Crooks
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, USA
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42
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Comparative efficacy of neutralizing antibodies elicited by recombinant hemagglutinin proteins from avian H5N1 influenza virus. J Virol 2008; 82:6200-8. [PMID: 18417563 DOI: 10.1128/jvi.00187-08] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although the human transmission of avian H5N1 virus remains low, the prevalence of this highly pathogenic infection in avian species underscores the need for a preventive vaccine that can be made without eggs. Here, we systematically analyze various forms of recombinant hemagglutinin (HA) protein for their potential efficacy as vaccines. Monomeric, trimeric, and oligomeric H5N1 HA proteins were expressed and purified from either insect or mammalian cells. The immunogenicity of different recombinant HA proteins was evaluated by measuring the neutralizing antibody response. Neutralizing antibodies to H5N1 HA were readily generated in mice immunized with the recombinant HA proteins, but they varied in potency depending on their multimeric nature and cell source. Among the HA proteins, a high-molecular-weight oligomer elicited the strongest antibody response, followed by the trimer; the monomer showed minimal efficacy. The coexpression of another viral surface protein, neuraminidase, did not affect the immunogenicity of the HA oligomer, as expected from the immunogenicity of trimers produced from insect cells. As anticipated, HA expressed in mammalian cells without NA retained the terminal sialic acid residues and failed to bind alpha2,3-linked sialic acid receptors. Taken together, these results suggest that recombinant HA proteins as individual or oligomeric trimers can elicit potent neutralizing antibody responses to avian H5N1 influenza viruses.
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43
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Characterization of neutralizing antibody responses elicited by clade A envelope immunogens derived from early transmitted viruses. J Virol 2008; 82:5912-21. [PMID: 18400850 DOI: 10.1128/jvi.00389-08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vast majority of studies with candidate immunogens based on the human immunodeficiency virus envelope (Env) have been conducted with Env proteins derived from clade B viruses isolated during chronic infection. Whether non-clade B Env protein immunogens will elicit antibodies with epitope specificities that are similar to those of antibodies elicited by clade B Envs and whether the antibodies elicited by Envs derived from early transmitted viruses will be similar to those elicited by Envs derived from viruses isolated during chronic infection are currently unknown. Here we performed immunizations with four clade A Envs, cloned directly from the peripheral blood of infected individuals during acute infection, which differed in lengths and extents of glycosylation. The antibody responses elicited by these four Envs were compared to each other and to those elicited by a well-characterized clade B Env immunogen derived from the SF162 virus, which was isolated during chronic infection. Only one clade A Env, the one with the fewer glycosylation sites, elicited homologous neutralizing antibodies (NAbs); these did not target the V1, V2, or V3 regions. In contrast, all four clade A Envs elicited anti-V3 NAbs against "easy-to-neutralize" clade B and clade A isolates, irrespective of the variable region length and extent of glycosylation of the Env used as an immunogen. These anti-V3 NAbs did not access their epitopes on homologous and heterologous clade A, or B, neutralization-resistant viruses. The length and extent of glycosylation of the variable regions on the clade A Env immunogens tested did not affect the breadth of the elicited NAbs. Our data also indicate that the development of cross-reactive NAbs against clade A viruses faces similar hurdles to the development of cross-reactive anti-clade B NAbs.
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44
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Kim S, Pang HB, Kay MS. Peptide mimic of the HIV envelope gp120-gp41 interface. J Mol Biol 2007; 376:786-97. [PMID: 18178220 DOI: 10.1016/j.jmb.2007.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 09/29/2007] [Accepted: 12/03/2007] [Indexed: 10/22/2022]
Abstract
The human immunodeficiency virus envelope glycoprotein (Env) is composed of surface (gp120) and transmembrane (gp41) subunits, which are noncovalently associated on the viral surface. Human immunodeficiency virus Env mediates viral entry after undergoing a complex series of conformational changes induced by interaction with cellular CD4 and a chemokine coreceptor. These changes propagate from gp120 to gp41 via the gp120-gp41 interface, ultimately exposing gp41 and allowing it to form the trimer-of-hairpins structure that provides the driving force for membrane fusion. Key unresolved questions about the gp120-gp41 interface include the specific regions of gp41 and gp120 involved, the mechanism by which receptor and coreceptor-binding-induced conformational changes in gp120 are communicated to gp41, how trimer-of-hairpins formation is prevented in the prefusogenic gp120-gp41 complex, and, ultimately, the structure of the prefusion gp120-gp41 complex. Here, we develop a biochemical model system that mimics a key portion of the gp120-gp41 interface in the prefusogenic state. We find that a gp41 fragment containing the disulfide bond loop and C-peptide region binds primarily to the gp120 C5 region and that this interaction is incompatible with trimer-of-hairpins formation. Based on these data, we propose that in prefusogenic Env, gp120 sequesters the gp41 C-peptide region away from the N-trimer region, preventing trimer-of-hairpins formation until coreceptor binding disrupts this interface. This model system is a valuable tool for studying the gp120-gp41 complex, conformational changes induced by CD4 and coreceptor binding, and the mechanism of membrane fusion.
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Affiliation(s)
- Sunghwan Kim
- Department of Biochemistry, University of Utah School of Medicine, 15 North Medical Drive East, Room 4100, Salt Lake City, UT 84112-5650, USA
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45
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Comparative evaluation of trimeric envelope glycoproteins derived from subtype C and B HIV-1 R5 isolates. Virology 2007; 372:273-90. [PMID: 18061231 DOI: 10.1016/j.virol.2007.10.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Revised: 07/19/2007] [Accepted: 10/18/2007] [Indexed: 11/20/2022]
Abstract
We previously reported that an envelope (Env) glycoprotein immunogen (o-gp140DeltaV2SF162) containing a partial deletion in the second variable loop (V2) derived from the R5-tropic HIV-1 isolate SF162 partially protected vaccinated rhesus macaques against pathogenic SHIV(SF162P4) virus. Extending our studies to subtype C isolate TV1, we have purified o-gp140DeltaV2TV1 (subtype C DeltaV2 trimer) to homogeneity, performed glycosylation analysis, and determined its ability to bind CD4, as well as a panel of well-characterized neutralizing monoclonal antibodies (mAb). In general, critical epitopes are preserved on the subtype C DeltaV2 trimer; however, we did not observe significant binding for the b12 mAb. The molecular mass of subtype C DeltaV2 trimer was found to be 450 kDa, and the hydrodynamic radius was found to be 10.87 nm. Our data suggest that subtype C DeltaV2 trimer binds to CD4 with an affinity comparable to o-gp140DeltaV2SF162 (subtype B DeltaV2 trimer). Using isothermal titration calorimetric (ITC) analysis, we demonstrated that all three CD4 binding sites (CD4-BS) in both subtype C and B trimers are exposed and accessible. However, compared to subtype B trimer, the three CD4-BS in subtype C trimer have different affinities for CD4, suggesting a cooperativity of CD4 binding in subtype C trimer but not in subtype B trimer. Negative staining electron microscopy of the subtype C DeltaV2 trimer has demonstrated that it is in fact a trimer. These results highlight the importance of studying subtype C Env, and also of developing appropriate subtype C-specific reagents that may be used for better immunological characterization of subtype C Env for developing an AIDS vaccine.
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46
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Denadai AML, Teixeira KI, Santoro MM, Pimenta AMC, Cortés ME, Sinisterra RD. Supramolecular self-assembly of β-cyclodextrin: an effective carrier of the antimicrobial agent chlorhexidine. Carbohydr Res 2007; 342:2286-96. [PMID: 17618611 DOI: 10.1016/j.carres.2007.05.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Revised: 05/01/2007] [Accepted: 05/03/2007] [Indexed: 10/23/2022]
Abstract
The supramolecular assembly between chlorhexidine and cyclomaltoheptaose (beta-cyclodextrin, betaCD) was characterized using NMR spectroscopy ((1)H, T(1), and ROESY), ESIMS and ITC. NMR data suggest the formation of high ordered complexes. ESIMS and ITC allowed the confirmation of the average stoichiometry as 1:4 and the thermodynamic data, also obtained by ITC, showed that the assembly is strongly stabilized by short distance interactions, but suffers a strong, opposite effect of entropy reduction. The antimicrobial activity of 1:1, 1:2, 1:3, and 1:4 Clx/betaCD molar ratio mixtures was investigated in aqueous solution and after incorporation into mucoadhesive gels. These were used to determine the initial and the long-term antimicrobial activity, respectively, toward Actinobacillus actinomycetemcomitans (A.a.) (Y4-FDC) and Enterococcus faecalis (E.f.) (ATCC 14508) strains. The results showed that A.a. and E.f. were more susceptible to the 1:4 molar ratio mixture in either solution or gel (p<0.05).
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Affiliation(s)
- Angelo M L Denadai
- Departamento de Química, Instituto de Ciências Exactas, Universidade Federal de Minas Gerais, UFMG, Avenida Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
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47
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Backovic M, Leser GP, Lamb RA, Longnecker R, Jardetzky TS. Characterization of EBV gB indicates properties of both class I and class II viral fusion proteins. Virology 2007; 368:102-13. [PMID: 17655906 PMCID: PMC2131761 DOI: 10.1016/j.virol.2007.06.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 05/25/2007] [Accepted: 06/27/2007] [Indexed: 11/18/2022]
Abstract
To gain insight into Epstein-Barr virus (EBV) glycoprotein B (gB), recombinant, secreted variants were generated. The role of putative transmembrane regions, the proteolytic processing and the oligomerization state of the gB variants were investigated. Constructs containing 2 of 3 C-terminal hydrophobic regions were secreted, indicating that these do not act as transmembrane anchors. The efficiency of cleavage of the gB furin site was found to depend on the nature of C-terminus. All of the gB constructs formed rosette structures reminiscent of the postfusion aggregates formed by other viral fusion proteins. However, substitution of putative fusion loop residues, WY(112-113) and WLIY(193-196), with less hydrophobic amino acids from HSV-1 gB, produced trimeric protein and abrogated the ability of the EBV gB ectodomains to form rosettes. These data demonstrate biochemical features of EBV gB that are characteristic of other class I and class II viral fusion proteins, but not of HSV-1 gB.
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Affiliation(s)
- Marija Backovic
- Department of Biochemistry, Molecular Biology, Cell Biology, Northwestern University, Evanston, IL 60208, USA
| | - George P. Leser
- Department of Biochemistry, Molecular Biology, Cell Biology, Northwestern University, Evanston, IL 60208, USA
| | - Robert A. Lamb
- Department of Biochemistry, Molecular Biology, Cell Biology, Northwestern University, Evanston, IL 60208, USA
- Howard Hughes Medical Institute, Northwestern University, Evanston, IL 60208, USA
| | - Richard Longnecker
- Department of Microbiology and Immunology, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Theodore S. Jardetzky
- Department of Biochemistry, Molecular Biology, Cell Biology, Northwestern University, Evanston, IL 60208, USA
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48
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Iyer SPN, Franti M, Krauchuk AA, Fisch DN, Ouattara AA, Roux KH, Krawiec L, Dey AK, Beddows S, Maddon PJ, Moore JP, Olson WC. Purified, proteolytically mature HIV type 1 SOSIP gp140 envelope trimers. AIDS Res Hum Retroviruses 2007; 23:817-28. [PMID: 17604546 DOI: 10.1089/aid.2006.0261] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
HIV type 1 (HIV-1) envelope is a noncovalent trimer of gp120-gp41 heterodimers, and its lability has hindered structural studies. SOSIP gp140 is a soluble, proteolytically mature form of the HIV-1 envelope wherein gp120-gp41 interactions are stabilized via a disulfide bond and gp41 contains an additional trimer-stabilizing point mutation. We describe the isolation of a substantially pure preparation of SOSIP gp140 trimers derived from KNH1144, a subtype A isolate. Following initial purification, the only significant contaminant was higher-order gp140 aggregates; however, 0.05% Tween 20 quantitatively converted these aggregates into trimers. The surfactant effect was rapid, dose dependent, and similarly effective for a subtype B SOSIP gp140. Surfactant-treated SOSIP gp140 retained favorable antigenicity and formed compact trimers 12-13 nm in size as determined by electron microscopy. This report provides the first description of homogeneous, cleaved HIV-1 envelope trimers. These proteins may be useful as vaccine immunogens and for studying structure-function relationships within the HIV-1 envelope glycoproteins.
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Dey B, Pancera M, Svehla K, Shu Y, Xiang SH, Vainshtein J, Li Y, Sodroski J, Kwong PD, Mascola JR, Wyatt R. Characterization of human immunodeficiency virus type 1 monomeric and trimeric gp120 glycoproteins stabilized in the CD4-bound state: antigenicity, biophysics, and immunogenicity. J Virol 2007; 81:5579-93. [PMID: 17360741 PMCID: PMC1900256 DOI: 10.1128/jvi.02500-06] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human immunodeficiency virus type 1 exterior gp120 envelope glycoprotein is highly flexible, and this flexibility may contribute to the inability of monomeric gp120 immunogens to elicit broadly neutralizing antibodies. We previously showed that an S375W modification of a critical interfacial cavity central to the primary receptor binding site, the Phe43 cavity, stabilizes gp120 into the CD4-bound state. However, the immunological effects of this cavity-altering replacement were never tested. Subsequently, we screened other mutations that, along with the S375W alteration, might further stabilize the CD4-bound state. Here, we define a selected second cavity-altering replacement, T257S, and analyze the double mutations in several gp120 envelope glycoprotein contexts. The gp120 glycoproteins with the T257S-plus-S375W double mutation (T257S+S375W) have a superior antigenic profile compared to the originally identified single S375W replacement in terms of enhanced recognition by the broadly neutralizing CD4 binding-site antibody b12. Isothermal titration calorimetry measuring the entropy of the gp120 interaction with CD4 indicated that the double mutant was also stabilized into the CD4-bound state, with increasing relative fixation between core, full-length monomeric, and full-length trimeric versions of gp120. A significant increase in gp120 affinity for CD4 was also observed for the cavity-filling mutants relative to wild-type gp120. The most conformationally constrained T257S+S375W trimeric gp120 proteins were selected for immunogenicity analysis in rabbits and displayed a trend of improvement relative to their wild-type counterparts in terms of eliciting neutralizing antibodies. Together, the results suggest that conformational stabilization may improve the ability of gp120 to elicit neutralizing antibodies.
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Affiliation(s)
- Barna Dey
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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50
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Young KR, McBurney SP, Karkhanis LU, Ross TM. Virus-like particles: designing an effective AIDS vaccine. Methods 2007; 40:98-117. [PMID: 16997718 DOI: 10.1016/j.ymeth.2006.05.024] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2005] [Accepted: 05/05/2006] [Indexed: 01/10/2023] Open
Abstract
Viruses that infect eukaryotic organisms have the unique characteristic of self-assembling into particles. The mammalian immune system is highly attuned to recognizing and attacking these viral particles following infection. The use of particle-based immunogens, often delivered as live-attenuated viruses, has been an effective vaccination strategy for a variety of viruses. The development of an effective vaccine against the human immunodeficiency virus (HIV) has proven to be a challenge, since HIV infects cells of the immune system causing severe immunodeficiency resulting in the syndrome known as AIDS. In addition, the ability of the virus to adapt to immune pressure and reside in an integrated form in host cells presents hurdles for vaccinologists to overcome. A particle-based vaccine strategy has promise for eliciting high titer, long-lived, immune responses to a diverse number of viral epitopes against different HIV antigens. Live-attenuated viruses are effective at generating both cellular and humoral immune responses. However, while these vaccines stimulate immunity, challenged animals rarely clear the viral infection and the degree of attenuation directly correlates with protection from disease. Further, a live-attenuated vaccine has the potential to revert to a pathogenic form. Alternatively, virus-like particles (VLPs) mimic the viral particle without causing an immunodeficiency disease. VLPs are self-assembling, non-replicating, non-pathogenic particles that are similar in size and conformation to intact virions. A variety of VLPs for lentiviruses are currently in preclinical and clinical trials. This review focuses on our current status of VLP-based AIDS vaccines, regarding issues of purification and immune design for animal and clinical trials.
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Affiliation(s)
- Kelly R Young
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, PA 15261, USA
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