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Ringe RP, Colin P, Ozorowski G, Allen JD, Yasmeen A, Seabright GE, Lee JH, Antanasijevic A, Rantalainen K, Ketas T, Moore JP, Ward AB, Crispin M, Klasse PJ. Glycan heterogeneity as a cause of the persistent fraction in HIV-1 neutralization. PLoS Pathog 2023; 19:e1011601. [PMID: 37903160 PMCID: PMC10635575 DOI: 10.1371/journal.ppat.1011601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/09/2023] [Accepted: 10/05/2023] [Indexed: 11/01/2023] Open
Abstract
Neutralizing antibodies (NAbs) to multiple epitopes on the HIV-1-envelope glycoprotein (Env) have been isolated from infected persons. The potency of NAbs is measured more often than the size of the persistent fraction of infectivity at maximum neutralization, which may also influence preventive efficacy of active or passive immunization and the therapeutic outcome of the latter. Many NAbs neutralize HIV-1 CZA97.012, a clone of a Clade-C isolate, to ~100%. But here NAb PGT151, directed to a fusion-peptide epitope, left a persistent fraction of 15%. NAb PGT145, ligating the Env-trimer apex, left no detectable persistent fraction. The divergence in persistent fractions was further analyzed by depletion of pseudoviral populations of the most PGT151- and PGT145-reactive virions. Thereby, neutralization by the non-depleting NAb increased, whereas neutralization by the depleting NAb decreased. Furthermore, depletion by PGT151 increased sensitivity to autologous neutralization by sera from rabbits immunized with soluble native-like CZA97.012 trimer: substantial persistent fractions were reduced. NAbs in these sera target epitopes comprising residue D411 at the V4-β19 transition in a defect of the glycan shield on CZA97.012 Env. NAb binding to affinity-fractionated soluble native-like CZA97.012 trimer differed commensurately with neutralization in analyses by ELISA and surface plasmon resonance. Glycan differences between PGT151- and PGT145-purified trimer fractions were then demonstrated by mass spectrometry, providing one explanation for the differential antigenicity. These differences were interpreted in relation to a new structure at 3.4-Å resolution of the soluble CZA97.012 trimer determined by cryo-electron microscopy. The trimer adopted a closed conformation, refuting apex opening as the cause of reduced PGT145 binding to the PGT151-purified form. The evidence suggests that differences in binding and neutralization after trimer purification or pseudovirus depletion with PGT145 or PGT151 are caused by variation in glycosylation, and that some glycan variants affect antigenicity through direct effects on antibody contacts, whereas others act allosterically.
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Affiliation(s)
- Rajesh P. Ringe
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, United States of America
| | - Philippe Colin
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, United States of America
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Joel D. Allen
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Anila Yasmeen
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, United States of America
| | - Gemma E. Seabright
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Jeong Hyun Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Aleksandar Antanasijevic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Kimmo Rantalainen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Thomas Ketas
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, United States of America
| | - John P. Moore
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, United States of America
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - P. J. Klasse
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, United States of America
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2
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Rappazzo CG, Fernández-Quintero ML, Mayer A, Wu NC, Greiff V, Guthmiller JJ. Defining and Studying B Cell Receptor and TCR Interactions. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:311-322. [PMID: 37459189 PMCID: PMC10495106 DOI: 10.4049/jimmunol.2300136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/15/2023] [Indexed: 07/20/2023]
Abstract
BCRs (Abs) and TCRs (or adaptive immune receptors [AIRs]) are the means by which the adaptive immune system recognizes foreign and self-antigens, playing an integral part in host defense, as well as the emergence of autoimmunity. Importantly, the interaction between AIRs and their cognate Ags defies a simple key-in-lock paradigm and is instead a complex many-to-many mapping between an individual's massively diverse AIR repertoire, and a similarly diverse antigenic space. Understanding how adaptive immunity balances specificity with epitopic coverage is a key challenge for the field, and terms such as broad specificity, cross-reactivity, and polyreactivity remain ill-defined and are used inconsistently. In this Immunology Notes and Resources article, a group of experimental, structural, and computational immunologists define commonly used terms associated with AIR binding, describe methodologies to study these binding modes, as well as highlight the implications of these different binding modes for therapeutic design.
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Affiliation(s)
| | | | - Andreas Mayer
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK
| | - Nicholas C. Wu
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Victor Greiff
- Department of Immunology, University of Oslo and Oslo University Hospital, 0372 Oslo, Norway
| | - Jenna J. Guthmiller
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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3
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Fili M, Hu G, Han C, Kort A, Trettin J, Haim H. A classification algorithm based on dynamic ensemble selection to predict mutational patterns of the envelope protein in HIV-infected patients. Algorithms Mol Biol 2023; 18:4. [PMID: 37337202 DOI: 10.1186/s13015-023-00228-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 06/04/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Therapeutics against the envelope (Env) proteins of human immunodeficiency virus type 1 (HIV-1) effectively reduce viral loads in patients. However, due to mutations, new therapy-resistant Env variants frequently emerge. The sites of mutations on Env that appear in each patient are considered random and unpredictable. Here we developed an algorithm to estimate for each patient the mutational state of each position based on the mutational state of adjacent positions on the three-dimensional structure of the protein. METHODS We developed a dynamic ensemble selection algorithm designated k-best classifiers. It identifies the best classifiers within the neighborhood of a new observation and applies them to predict the variability state of each observation. To evaluate the algorithm, we applied amino acid sequences of Envs from 300 HIV-1-infected individuals (at least six sequences per patient). For each patient, amino acid variability values at all Env positions were mapped onto the three-dimensional structure of the protein. Then, the variability state of each position was estimated by the variability at adjacent positions of the protein. RESULTS The proposed algorithm showed higher performance than the base learner and a panel of classification algorithms. The mutational state of positions in the high-mannose patch and CD4-binding site of Env, which are targeted by multiple therapeutics, was predicted well. Importantly, the algorithm outperformed other classification techniques for predicting the variability state at multi-position footprints of therapeutics on Env. CONCLUSIONS The proposed algorithm applies a dynamic classifier-scoring approach that increases its performance relative to other classification methods. Better understanding of the spatiotemporal patterns of variability across Env may lead to new treatment strategies that are tailored to the unique mutational patterns of each patient. More generally, we propose the algorithm as a new high-performance dynamic ensemble selection technique.
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Affiliation(s)
- Mohammad Fili
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, 3014 Black Engineering, 2529 Union Drive, Ames, IA, 50011, USA
| | - Guiping Hu
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, 3014 Black Engineering, 2529 Union Drive, Ames, IA, 50011, USA.
| | - Changze Han
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, 51 Newton Rd, 3-770 BSB, Iowa City, IA, 52242, USA
| | - Alexa Kort
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, 51 Newton Rd, 3-770 BSB, Iowa City, IA, 52242, USA
| | - John Trettin
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, 3014 Black Engineering, 2529 Union Drive, Ames, IA, 50011, USA
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, 51 Newton Rd, 3-770 BSB, Iowa City, IA, 52242, USA.
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Gillmann KM, Temme JS, Marglous S, Brown CE, Gildersleeve JC. Anti-glycan monoclonal antibodies: Basic research and clinical applications. Curr Opin Chem Biol 2023; 74:102281. [PMID: 36905763 PMCID: PMC10732169 DOI: 10.1016/j.cbpa.2023.102281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/01/2023] [Accepted: 02/05/2023] [Indexed: 03/12/2023]
Abstract
Anti-glycan monoclonal antibodies have important applications in human health and basic research. Therapeutic antibodies that recognize cancer- or pathogen-associated glycans have been investigated in numerous clinical trials, resulting in two FDA-approved biopharmaceuticals. Anti-glycan antibodies are also utilized to diagnose, prognosticate, and monitor disease progression, as well as to study the biological roles and expression of glycans. High-quality anti-glycan mAbs are still in limited supply, highlighting the need for new technologies for anti-glycan antibody discovery. This review discusses anti-glycan monoclonal antibodies with applications to basic research, diagnostics, and therapeutics, focusing on recent advances in mAbs targeting cancer- and infectious disease-associated glycans.
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Affiliation(s)
- Kara M Gillmann
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - J Sebastian Temme
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Samantha Marglous
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Claire E Brown
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
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Rojas Chávez RA, Boyt D, Schwery N, Han C, Wu L, Haim H. Commonly Elicited Antibodies against the Base of the HIV-1 Env Trimer Guide the Population-Level Evolution of a Structure-Regulating Region in gp41. J Virol 2022; 96:e0040622. [PMID: 35658529 PMCID: PMC9278142 DOI: 10.1128/jvi.00406-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/11/2022] [Indexed: 01/28/2023] Open
Abstract
The antibody response against the HIV-1 envelope glycoproteins (Envs) guides evolution of this protein within each host. Whether antibodies with similar target specificities are elicited in different individuals and affect the population-level evolution of Env is poorly understood. To address this question, we analyzed properties of emerging variants in the gp41 fusion peptide-proximal region (FPPR) that exhibit distinct evolutionary patterns in HIV-1 clade B. For positions 534, 536, and 539 in the FPPR, alanine was the major emerging variant. However, 534A and 536A show a constant frequency in the population between 1979 and 2016, whereas 539A is gradually increasing. To understand the basis for these differences, we introduced alanine substitutions in the FPPR of primary HIV-1 strains and examined their functional and antigenic properties. Evolutionary patterns could not be explained by fusion competence or structural stability of the emerging variants. Instead, 534A and 536A exhibited modest but significant increases in sensitivity to antibodies against the membrane-proximal external region (MPER) and gp120-gp41 interface. These Envs were also more sensitive to poorly neutralizing sera from HIV-1-infected individuals than the clade ancestral form or 539A variant. Competition binding assays confirmed for all sera tested the presence of antibodies against the base of the Env trimer that compete with monoclonal antibodies targeting the MPER and gp120-gp41 interface. Our findings suggest that weakly neutralizing antibodies against the trimer base are commonly elicited; they do not exert catastrophic population size reduction effects on emerging variants but, instead, determine their set point frequencies in the population and historical patterns of change. IMPORTANCE Infection by HIV-1 elicits formation of antibodies that target the viral Env proteins and can inactivate the virus. The specific targets of these antibodies vary among infected individuals. It is unclear whether some target specificities are shared among the antibody responses of different individuals. We observed that antibodies against the base of the Env protein are commonly elicited during infection. The selective pressure applied by such antibodies is weak. As a result, they do not completely eliminate the sensitive forms of the virus from the population, but maintain their frequency at a low level that has not increased since the beginning of the AIDS pandemic. Interestingly, the changes in Env do not occur at the sites targeted by the antibodies, but at a distinct region of Env, the fusion peptide-proximal region, which regulates their exposure.
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Affiliation(s)
- Roberth Anthony Rojas Chávez
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Devlin Boyt
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Nathan Schwery
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Changze Han
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Li Wu
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
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6
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Schapiro HM, Khasnis MD, Ahn K, Karagiaridi A, Hayden S, Cilento ME, Root MJ. Regulation of epitope exposure in the gp41 membrane-proximal external region through interactions at the apex of HIV-1 Env. PLoS Pathog 2022; 18:e1010531. [PMID: 35584191 PMCID: PMC9154124 DOI: 10.1371/journal.ppat.1010531] [Citation(s) in RCA: 4] [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: 10/21/2021] [Revised: 05/31/2022] [Accepted: 04/18/2022] [Indexed: 11/19/2022] Open
Abstract
Glycoprotein Env of human immunodeficiency virus type 1 (HIV-1) mediates viral entry through membrane fusion. Composed of gp120 and gp41 subunits arranged as a trimer-of-heterodimers, Env adopts a metastable, highly dynamic conformation on the virion surface. This structural plasticity limits the temporospatial exposure of many highly conserved, neutralizing epitopes, contributing to the difficulty in developing effective HIV-1 vaccines. Here, we employed antibody neutralization of HIV-1 infectivity to investigate how inter- and intra-gp120 interactions mediated by variable loops V1/V2 and V3 at the Env apex regulate accessibility of the gp41 membrane-proximal external region (MPER) at the Env base. Swapping the V3 loop from EnvSF162 into the EnvHXB2 background shifted MPER exposure from the prefusogenic state to a functional intermediate conformation that was distinct from the prehairpin-intermediate state sensitive to gp41-targeted fusion inhibitors. The V3-loop swap had a profound impact on global protein dynamics, biasing the equilibrium to a closed conformation resistant to most anti-gp120 antibodies, stabilizing the protein to both cold- and soluble CD4-induced Env inactivation, and increasing the CD4 requirements for viral entry. Further dissection of the EnvHXB2 V3 loop revealed that residue 306 uniquely modulated epitope exposure and trimer stability. The R306S substitution substantially decreased sensitivity to antibodies targeting the gp41 MPER and, surprisingly, the gp120 V3-loop crown (residues 312–315), but had only modest effects on exposure of intervening gp120 epitopes. Furthermore, the point mutation reduced soluble CD4-induced inactivation, but had no impact on cold inactivation. The residue appeared to exert its effects by electrostatically modifying the strength of intra-subunit interactions between the V1/V2 and V3 loops. The distinct patterns of neutralization and stability pointed to a novel prefusogenic Env conformation along the receptor activation pathway and suggested that apical Env-regulation of gp41 MPER exposure can be decoupled from much of the dynamics of gp120 subunits. Surface glycoprotein Env is the main target for neutralizing antibodies elicited by HIV-1 vaccines. Env spontaneously fluctuates among different structures, limiting exposure of many attractive antibody-binding epitopes and, thereby, confounding vaccine development. To characterize these fluctuations, we examined how exposure of the MPER epitope found at the base of Env is regulated by interactions of the V3 loop located in the apex. Starting with an extremely flexible Env with a readily-exposed MPER, we identified two alterations that substantially restricted antibody access to the epitope. The first, a wholesale swap of V3 loops between HIV-1 strains, energetically stabilized Env in a closed structure that restricted access to antibodies throughout the protein. The second, a point mutation that altered V3-loop charge, specifically destabilized the MPER-exposed conformation but had minimal impact on antibody access to Env regions in between the apex and base. The results indicate that MPER exposure is not explicitly tied to the dynamics of Env regions between the apex and base and suggest a new structural fluctuation during Env activation.
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Affiliation(s)
- Hannah M. Schapiro
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Mukta D. Khasnis
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Koree Ahn
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Alexandra Karagiaridi
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Stephanie Hayden
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Maria E. Cilento
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Michael J. Root
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
- * E-mail:
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Castillo-Ramírez DA, Carrasco-Yépez MM, Rodríguez-Mera IB, Reséndiz-Albor AA, Rosales-Cruz É, Rojas-Hernández S. A 250-kDa glycoprotein of Naegleria fowleri induces protection and modifies the expression of α4β1 and LFA-1 on T and B lymphocytes in mouse meningitis model. Parasite Immunol 2021; 43:e12882. [PMID: 34570374 DOI: 10.1111/pim.12882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 09/10/2021] [Accepted: 09/20/2021] [Indexed: 11/29/2022]
Abstract
The aims of this work were to evaluate the protective role of the 250-kDa polypeptide band of Naegleria fowleri. We designed an immunization strategy in Balb/c mice which were inoculated by i.n. route with an electrocuted 250-kDa polypeptide band of N. fowleri. We observed that the 250-kDa band induced 80% of protection, whereas the coadministration with Cholera Toxin induced 100% of protection. Moreover, high levels of IgA- and IgG-specific antibodies were detected by ELISA assay. We also analysed migration molecules (α4β1 and LFA-1) on T and B lymphocytes in nose-associated lymphoid tissue (NALT), cervical lymph nodes (CN) and nasal passages (NP) by flow cytometry. We observed that the percentage of B cells (B220/α4β1) and T cells (CD4/α4β1) in NP were higher in all immunized groups compared with the other compartments analysed. Finally, we detected by immunohistochemistry ICAM-1 and V-CAM-1 in the nasal cavity. The immunization with the 250-kDa polypeptide band, protect mice against N. fowleri challenge and modifies migration molecules and their ligands.
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Affiliation(s)
- Diego A Castillo-Ramírez
- Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Escuela Superior de Medicina, Ciudad de México, México
| | - María Maricela Carrasco-Yépez
- Laboratorio de Microbiología Ambiental, Grupo CyMA, UIICSE, FES Iztacala, UNAM, Estado de México, Tlalnepantla de Baz, México
| | - Itzel Berenice Rodríguez-Mera
- Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Escuela Superior de Medicina, Ciudad de México, México
| | - Aldo Arturo Reséndiz-Albor
- Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Escuela Superior de Medicina, Ciudad de México, México
| | - Érica Rosales-Cruz
- Laboratorio de Investigación en Hematopatología, Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, México City, México
| | - Saúl Rojas-Hernández
- Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Escuela Superior de Medicina, Ciudad de México, México
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Martí-Marí O, Martínez-Gualda B, de la Puente-Secades S, Mills A, Quesada E, Abdelnabi R, Sun L, Boonen A, Noppen S, Neyts J, Schols D, Camarasa MJ, Gago F, San-Félix A. Double Arylation of the Indole Side Chain of Tri- and Tetrapodal Tryptophan Derivatives Renders Highly Potent HIV-1 and EV-A71 Entry Inhibitors†. J Med Chem 2021; 64:10027-10046. [PMID: 34229438 PMCID: PMC8389807 DOI: 10.1021/acs.jmedchem.1c00315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
We have recently
described a new generation of potent human immunodeficiency
virus (HIV) and EV-A71 entry inhibitors. The prototypes contain three
or four tryptophan (Trp) residues bearing an isophthalic acid moiety
at the C2 position of each side-chain indole ring. This work is now
extended by both shifting the position of the isophthalic acid to
C7 and synthesizing doubly arylated C2/C7 derivatives. The most potent
derivative (50% effective concentration (EC50) HIV-1, 6
nM; EC50 EV-A71, 40 nM), 33 (AL-518), is a C2/C7 doubly arylated tetrapodal compound. Its superior anti-HIV
potency with respect to the previous C2-arylated prototype is in consonance
with its higher affinity for the viral gp120. 33 (AL-518) showed comparable antiviral activities against X4
and R5 HIV-1 strains and seems to interact with the tip and base of
the gp120 V3 loop. Taken together, these findings support the interest
in 33 (AL-518) as a useful new prototype
for anti-HIV/EV71 drug development.
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Affiliation(s)
- Olaia Martí-Marí
- Instituto de Química Médica (IQM-CSIC), c/ Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Belén Martínez-Gualda
- Instituto de Química Médica (IQM-CSIC), c/ Juan de la Cierva 3, E-28006 Madrid, Spain
| | | | - Alberto Mills
- Área de Farmacología, Departamento de Ciencias Biomédicas y Unidad Asociada IQM-UAH, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Ernesto Quesada
- Instituto de Química Médica (IQM-CSIC), c/ Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Rana Abdelnabi
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium
| | - Liang Sun
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium
| | - Arnaud Boonen
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium
| | - Sam Noppen
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium
| | - Johan Neyts
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium
| | - Dominique Schols
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium
| | - María-José Camarasa
- Instituto de Química Médica (IQM-CSIC), c/ Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Federico Gago
- Área de Farmacología, Departamento de Ciencias Biomédicas y Unidad Asociada IQM-UAH, Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain
| | - Ana San-Félix
- Instituto de Química Médica (IQM-CSIC), c/ Juan de la Cierva 3, E-28006 Madrid, Spain
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Miller NL, Clark T, Raman R, Sasisekharan R. Glycans in Virus-Host Interactions: A Structural Perspective. Front Mol Biosci 2021; 8:666756. [PMID: 34164431 PMCID: PMC8215384 DOI: 10.3389/fmolb.2021.666756] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/19/2021] [Indexed: 11/13/2022] Open
Abstract
Many interactions between microbes and their hosts are driven or influenced by glycans, whose heterogeneous and difficult to characterize structures have led to an underappreciation of their role in these interactions compared to protein-based interactions. Glycans decorate microbe glycoproteins to enhance attachment and fusion to host cells, provide stability, and evade the host immune system. Yet, the host immune system may also target these glycans as glycoepitopes. In this review, we provide a structural perspective on the role of glycans in host-microbe interactions, focusing primarily on viral glycoproteins and their interactions with host adaptive immunity. In particular, we discuss a class of topological glycoepitopes and their interactions with topological mAbs, using the anti-HIV mAb 2G12 as the archetypical example. We further offer our view that structure-based glycan targeting strategies are ready for application to viruses beyond HIV, and present our perspective on future development in this area.
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Affiliation(s)
- Nathaniel L Miller
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Thomas Clark
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Rahul Raman
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Ram Sasisekharan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
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10
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Williams WB, Meyerhoff RR, Edwards RJ, Li H, Manne K, Nicely NI, Henderson R, Zhou Y, Janowska K, Mansouri K, Gobeil S, Evangelous T, Hora B, Berry M, Abuahmad AY, Sprenz J, Deyton M, Stalls V, Kopp M, Hsu AL, Borgnia MJ, Stewart-Jones GBE, Lee MS, Bronkema N, Moody MA, Wiehe K, Bradley T, Alam SM, Parks RJ, Foulger A, Oguin T, Sempowski GD, Bonsignori M, LaBranche CC, Montefiori DC, Seaman M, Santra S, Perfect J, Francica JR, Lynn GM, Aussedat B, Walkowicz WE, Laga R, Kelsoe G, Saunders KO, Fera D, Kwong PD, Seder RA, Bartesaghi A, Shaw GM, Acharya P, Haynes BF. Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies. Cell 2021; 184:2955-2972.e25. [PMID: 34019795 PMCID: PMC8135257 DOI: 10.1016/j.cell.2021.04.042] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/22/2021] [Accepted: 04/23/2021] [Indexed: 01/03/2023]
Abstract
Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.
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Affiliation(s)
- Wilton B Williams
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA.
| | - R Ryan Meyerhoff
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - R J Edwards
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Hui Li
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kartik Manne
- Duke Human Vaccine Institute, Durham, NC 27710, USA
| | | | - Rory Henderson
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, NC 27708, USA
| | | | | | | | | | - Bhavna Hora
- Duke Human Vaccine Institute, Durham, NC 27710, USA
| | | | | | | | | | | | - Megan Kopp
- Duke Human Vaccine Institute, Durham, NC 27710, USA
| | - Allen L Hsu
- Genome Integrity and Structural Biology Laboratory, NIEHS, NIH, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Mario J Borgnia
- Genome Integrity and Structural Biology Laboratory, NIEHS, NIH, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | | | - Matthew S Lee
- Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Naomi Bronkema
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Immunology, Duke University, Durham, NC 27710, USA; Department of Pediatrics, Duke University, Durham, NC 27710, USA
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Todd Bradley
- Duke Human Vaccine Institute, Durham, NC 27710, USA
| | - S Munir Alam
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | | | | | - Thomas Oguin
- Duke Human Vaccine Institute, Durham, NC 27710, USA
| | - Gregory D Sempowski
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Mattia Bonsignori
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | | | - David C Montefiori
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Surgery, Duke University, Durham, NC 27710, USA
| | - Michael Seaman
- Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Sampa Santra
- Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - John Perfect
- Department of Medicine, Duke University, Durham, NC 27710, USA
| | | | - Geoffrey M Lynn
- Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA; Avidea Technologies, Inc., Baltimore, MD, USA
| | | | | | - Richard Laga
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Garnett Kelsoe
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Immunology, Duke University, Durham, NC 27710, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Immunology, Duke University, Durham, NC 27710, USA; Department of Surgery, Duke University, Durham, NC 27710, USA
| | - Daniela Fera
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, USA
| | - Peter D Kwong
- Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA
| | - Robert A Seder
- Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA
| | - Alberto Bartesaghi
- Department of Computer Science, Duke University, Durham, NC 27708, USA; Department of Biochemistry, Duke University, Durham, NC 27705, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - George M Shaw
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Surgery, Duke University, Durham, NC 27710, USA.
| | - Barton F Haynes
- Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA; Department of Immunology, Duke University, Durham, NC 27710, USA.
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11
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Lee CCD, Watanabe Y, Wu NC, Han J, Kumar S, Pholcharee T, Seabright GE, Allen JD, Lin CW, Yang JR, Liu MT, Wu CY, Ward AB, Crispin M, Wilson IA. A cross-neutralizing antibody between HIV-1 and influenza virus. PLoS Pathog 2021; 17:e1009407. [PMID: 33750987 PMCID: PMC8016226 DOI: 10.1371/journal.ppat.1009407] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 04/01/2021] [Accepted: 02/17/2021] [Indexed: 11/19/2022] Open
Abstract
Incessant antigenic evolution enables the persistence and spread of influenza virus in the human population. As the principal target of the immune response, the hemagglutinin (HA) surface antigen on influenza viruses continuously acquires and replaces N-linked glycosylation sites to shield immunogenic protein epitopes using host-derived glycans. Anti-glycan antibodies, such as 2G12, target the HIV-1 envelope protein (Env), which is even more extensively glycosylated and contains under-processed oligomannose-type clusters on its dense glycan shield. Here, we illustrate that 2G12 can also neutralize human seasonal influenza A H3N2 viruses that have evolved to present similar oligomannose-type clusters on their HAs from around 20 years after the 1968 pandemic. Using structural biology and mass spectrometric approaches, we find that two N-glycosylation sites close to the receptor binding site (RBS) on influenza hemagglutinin represent the oligomannose cluster recognized by 2G12. One of these glycan sites is highly conserved in all human H3N2 strains and the other emerged during virus evolution. These two N-glycosylation sites have also become crucial for fitness of recent H3N2 strains. These findings shed light on the evolution of the glycan shield on influenza virus and suggest 2G12-like antibodies can potentially act as broad neutralizers to target human enveloped viruses.
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Affiliation(s)
- Chang-Chun D. Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Yasunori Watanabe
- School of Biological Sciences, University of Southampton, Southampton, England, United Kingdom
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, England, United Kingdom
- Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Oxford, England, United Kingdom
| | - Nicholas C. Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Julianna Han
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Sonu Kumar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Gemma E. Seabright
- School of Biological Sciences, University of Southampton, Southampton, England, United Kingdom
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, England, United Kingdom
| | - Joel D. Allen
- School of Biological Sciences, University of Southampton, Southampton, England, United Kingdom
| | - Chih-Wei Lin
- Department of Chemistry, The Scripps Research Institute, La Jolla, California, United States of America
| | - Ji-Rong Yang
- Centers for Disease Control, Taipei City, Taiwan
| | | | - Chung-Yi Wu
- Genomics Research Center, Academia Sinica, Taipei City, Taiwan
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton, England, United Kingdom
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
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12
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Wei Q, Hargett AA, Knoppova B, Duverger A, Rawi R, Shen CH, Farney SK, Hall S, Brown R, Keele BF, Heath SL, Saag MS, Kutsch O, Chuang GY, Kwong PD, Moldoveanu Z, Raska M, Renfrow MB, Novak J. Glycan Positioning Impacts HIV-1 Env Glycan-Shield Density, Function, and Recognition by Antibodies. iScience 2020; 23:101711. [PMID: 33205023 PMCID: PMC7649354 DOI: 10.1016/j.isci.2020.101711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/12/2020] [Accepted: 10/16/2020] [Indexed: 11/24/2022] Open
Abstract
HIV-1 envelope (Env) N-glycosylation impact virus-cell entry and immune evasion. How each glycan interacts to shape the Env-protein-sugar complex and affects Env function is not well understood. Here, analysis of two Env variants from the same donor, with differing functional characteristics and N-glycosylation-site composition, revealed that changes to key N-glycosylation sites affected the Env structure at distant locations and had a ripple effect on Env-wide glycan processing, virus infectivity, antibody recognition, and virus neutralization. Specifically, the N262 glycan, although not in the CD4-binding site, modulated Env binding to the CD4 receptor, affected Env recognition by several glycan-dependent neutralizing antibodies, and altered site-specific glycosylation heterogeneity, with, for example, N448 displaying limited glycan processing. Molecular-dynamic simulations visualized differences in glycan density and how specific oligosaccharide positions can move to compensate for a glycan loss. This study demonstrates how changes in individual glycans can alter molecular dynamics, processing, and function of the Env-glycan shield.
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Affiliation(s)
- Qing Wei
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
| | - Audra A. Hargett
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Barbora Knoppova
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
| | - Alexandra Duverger
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Reda Rawi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Chen-Hsiang Shen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - S. Katie Farney
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Stacy Hall
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
| | - Rhubell Brown
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Sonya L. Heath
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Michael S. Saag
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Olaf Kutsch
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter D. Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Zina Moldoveanu
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
| | - Milan Raska
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
- Department of Immunology, Palacky University Olomouc, Olomouc, Czech Republic
| | - Matthew B. Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street S, Birmingham, AL 35294, USA
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13
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Parajuli B, Acharya K, Nangarlia A, Zhang S, Parajuli B, Dick A, Ngo B, Abrams CF, Chaiken I. Identification of a glycan cluster in gp120 essential for irreversible HIV-1 lytic inactivation by a lectin-based recombinantly engineered protein conjugate. Biochem J 2020; 477:4263-4280. [PMID: 33057580 DOI: 10.1042/bcj20200495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 11/17/2022]
Abstract
We previously discovered a class of recombinant lectin conjugates, denoted lectin DLIs ('dual-acting lytic inhibitors') that bind to the HIV-1 envelope (Env) protein trimer and cause both lytic inactivation of HIV-1 virions and cytotoxicity of Env-expressing cells. To facilitate mechanistic investigation of DLI function, we derived the simplified prototype microvirin (MVN)-DLI, containing an MVN domain that binds high-mannose glycans in Env, connected to a DKWASLWNW sequence (denoted 'Trp3') derived from the membrane-associated region of gp41. The relatively much stronger affinity of the lectin component than Trp3 argues that the lectin functions to capture Env to enable Trp3 engagement and consequent Env membrane disruption and virolysis. The relatively simplified engagement pattern of MVN with Env opened up the opportunity, pursued here, to use recombinant glycan knockout gp120 variants to identify the precise Env binding site for MVN that drives DLI engagement and lysis. Using mutagenesis combined with a series of biophysical and virological experiments, we identified a restricted set of residues, N262, N332 and N448, all localized in a cluster on the outer domain of gp120, as the essential epitope for MVN binding. By generating these mutations in the corresponding HIV-1 virus, we established that the engagement of this glycan cluster with the lectin domain of MVN*-DLI is the trigger for DLI-derived virus and cell inactivation. Beyond defining the initial encounter step for lytic inactivation, this study provides a guide to further elucidate DLI mechanism, including the stoichiometry of Env trimer required for function, and downstream DLI optimization.
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Affiliation(s)
- Bibek Parajuli
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Kriti Acharya
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Aakansha Nangarlia
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Shiyu Zhang
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Bijay Parajuli
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Alexej Dick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Brendon Ngo
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
| | - Cameron F Abrams
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, U.S.A
| | - Irwin Chaiken
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, U.S.A
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14
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Seabright GE, Cottrell CA, van Gils MJ, D'addabbo A, Harvey DJ, Behrens AJ, Allen JD, Watanabe Y, Scaringi N, Polveroni TM, Maker A, Vasiljevic S, de Val N, Sanders RW, Ward AB, Crispin M. Networks of HIV-1 Envelope Glycans Maintain Antibody Epitopes in the Face of Glycan Additions and Deletions. Structure 2020; 28:897-909.e6. [PMID: 32433992 PMCID: PMC7416112 DOI: 10.1016/j.str.2020.04.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 02/27/2020] [Accepted: 04/28/2020] [Indexed: 11/22/2022]
Abstract
Numerous broadly neutralizing antibodies (bnAbs) have been identified that target the glycans of the HIV-1 envelope spike. Neutralization breadth is notable given that glycan processing can be substantially influenced by the presence or absence of neighboring glycans. Here, using a stabilized recombinant envelope trimer, we investigate the degree to which mutations in the glycan network surrounding an epitope impact the fine glycan processing of antibody targets. Using cryo-electron microscopy and site-specific glycan analysis, we reveal the importance of glycans in the formation of the 2G12 bnAb epitope and show that the epitope is only subtly impacted by variations in the glycan network. In contrast, we show that the PG9 and PG16 glycan-based epitopes at the trimer apex are dependent on the presence of the highly conserved surrounding glycans. Glycan networks underpin the conservation of bnAb epitopes and are an important parameter in immunogen design.
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Affiliation(s)
- Gemma E Seabright
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Christopher A Cottrell
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Marit J van Gils
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands
| | - Alessio D'addabbo
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - David J Harvey
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford OX3 7FZ, UK
| | - Anna-Janina Behrens
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Joel D Allen
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Yasunori Watanabe
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Nicole Scaringi
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Thomas M Polveroni
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Allison Maker
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Snezana Vasiljevic
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Natalia de Val
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD 21701, USA; Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rogier W Sanders
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands; Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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15
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Acharya P, Williams W, Henderson R, Janowska K, Manne K, Parks R, Deyton M, Sprenz J, Stalls V, Kopp M, Mansouri K, Edwards RJ, Meyerhoff RR, Oguin T, Sempowski G, Saunders K, Haynes BF. A glycan cluster on the SARS-CoV-2 spike ectodomain is recognized by Fab-dimerized glycan-reactive antibodies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.06.30.178897. [PMID: 32637953 PMCID: PMC7337383 DOI: 10.1101/2020.06.30.178897] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
UNLABELLED The COVID-19 pandemic caused by SARS-CoV-2 has escalated into a global crisis. The spike (S) protein that mediates cell entry and membrane fusion is the current focus of vaccine and therapeutic antibody development efforts. The S protein, like many other viral fusion proteins such as HIV-1 envelope (Env) and influenza hemagglutinin, is glycosylated with both complex and high mannose glycans. Here we demonstrate binding to the SARS-CoV-2 S protein by a category of Fab-dimerized glycan-reactive (FDG) HIV-1-induced broadly neutralizing antibodies (bnAbs). A 3.1 Å resolution cryo-EM structure of the S protein ectodomain bound to glycan-dependent HIV-1 bnAb 2G12 revealed a quaternary glycan epitope on the spike S2 domain involving multiple protomers. These data reveal a new epitope on the SARS-CoV-2 spike that can be targeted for vaccine design. HIGHLIGHTS Fab-dimerized, glycan-reactive (FDG) HIV-1 bnAbs cross-react with SARS-CoV-2 spike.3.1 Å resolution cryo-EM structure reveals quaternary S2 epitope for HIV-1 bnAb 2G12.2G12 targets glycans, at positions 709, 717 and 801, in the SARS-CoV-2 spike.Our studies suggest a common epitope for FDG antibodies centered around glycan 709.
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16
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Nguyen DN, Redman RL, Horiya S, Bailey JK, Xu B, Stanfield RL, Temme JS, LaBranche CC, Wang S, Rodal AA, Montefiori DC, Wilson IA, Krauss IJ. The Impact of Sustained Immunization Regimens on the Antibody Response to Oligomannose Glycans. ACS Chem Biol 2020; 15:789-798. [PMID: 32109354 PMCID: PMC7091532 DOI: 10.1021/acschembio.0c00053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
The high mannose
patch (HMP) of the HIV envelope protein (Env)
is the structure most frequently targeted by broadly neutralizing
antibodies; therefore, many researchers have attempted to use mimics
of this region as a vaccine immunogen. In our previous efforts, vaccinating
rabbits with evolved HMP mimic glycopeptides containing Man9 resulted in an overall antibody response targeting the glycan core
and linker rather than the full glycan or Manα1→2Man
tips of Man9 glycans. A possible reason could be processing
of our immunogen by host serum mannosidases. We sought to test whether
more prolonged dosing could increase the antibody response to intact
glycans, possibly by increasing the availability of intact Man9 to germinal centers. Here, we describe a study investigating
the impact of immunization regimen on antibody response by testing
immunogen delivery through bolus, an exponential series of mini doses,
or a continuously infusing mini-osmotic pump. Our results indicate
that, with our glycopeptide immunogens, standard bolus immunization
elicited the strongest HIV Env-binding antibody response, even though
higher overall titers to the glycopeptide were elicited by the exponential
and pump regimens. Antibody selectivity for intact glycan was, if
anything, slightly better in the bolus-immunized animals.
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Affiliation(s)
- Dung N. Nguyen
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Richard L. Redman
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Satoru Horiya
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Jennifer K. Bailey
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Bokai Xu
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Robyn L. Stanfield
- Department of Integrative Structural and Computational Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - J. Sebastian Temme
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Celia C. LaBranche
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Shiyu Wang
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Avital A. Rodal
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - David C. Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Isaac J. Krauss
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
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17
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Pisil Y, Yazici Z, Shida H, Matsushita S, Miura T. Specific Substitutions in Region V2 of gp120 env confer SHIV Neutralisation Resistance. Pathogens 2020; 9:pathogens9030181. [PMID: 32138199 PMCID: PMC7157653 DOI: 10.3390/pathogens9030181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 11/16/2022] Open
Abstract
A tier 2 SHIV-MK38 strain was obtained after two in vivo passages of tier 1 SHIV-MK1. SHIV-MK38#818, cloned from the MK38 strain, was neutralisation-resistant, like the parental MK38 strain, to SHIV-infected monkey plasma (MP), HIV-1-infected human pooled plasma (HPP), and KD247 monoclonal antibody (mAb) (anti-V3 gp120 env). We investigated the mechanisms underlying the resistance of #818, specifically the amino acid substitutions that confer resistance to MK1. We introduced amino acid substitutions in the MK1 envelope by in vitro mutagenesis and then compared the neutralisation resistance to MP, HPP, and KD247 mAb with #818 in a neutralisation assay using TZM-bl cells. We selected 11 substitutions in the V1, V2, C2, V4, C4, and V5 regions based on the alignment of env of MK1 and #818. The neutralisation resistance of the mutant MK1s with 7 of 11 substitutions in the V1, C2, C4, and V5 regions did not change significantly. These substitutions did not alter any negative charges or N-glycans. The substitutions N169D and K187E, which added negative charges, and S190N in the V2 region of gp120 and A389T in V4, which created sites for N-glycan, conferred high neutralisation resistance. The combinations N169D+K187E, N169D+S190N, and N169D+A389T resulted in MK1 neutralisation resistance close to that of #818. The combinations without 169D were neutralisation-sensitive. Therefore, N169D is the most important substitution for neutralisation resistance. This study demonstrated that although the V3 region sequences of #818 and MK1 are the same, V3 binding antibodies cannot neutralise #818 pseudovirus. Instead, mutations in the V2 and V4 regions inhibit the neutralisation of anti-V3 antibodies. We hypothesised that 169D and 190N altered the MK1 Env conformation so that the V3 region is buried. Therefore, the V2 region may block KD247 from binding to the tip of the V3 region.
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Affiliation(s)
- Yalcin Pisil
- Laboratory of Primate Model, Research Center for Infectious Diseases, Institute for Frontier Life and Medical Science, Kyoto University, Kyoto 615-8530, Japan;
| | - Zafer Yazici
- Department of Virology, Faculty of Veterinary Medicine, 19 Mayis University, Samsun 55270, Turkey;
| | - Hisatoshi Shida
- Division of Molecular Virology, Institute of Immunological Science, Hokkaido University, Hokkaido 060-0808, Japan;
| | - Shuzo Matsushita
- Center for AIDS Research, Kumamoto University, Kumamoto 860-8555, Japan;
| | - Tomoyuki Miura
- Laboratory of Primate Model, Research Center for Infectious Diseases, Institute for Frontier Life and Medical Science, Kyoto University, Kyoto 615-8530, Japan;
- Correspondence:
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18
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Zhao Y, Lee CK, Lin CH, Gassen RB, Xu X, Huang Z, Xiao C, Bonorino C, Lu LF, Bui JD, Hui E. PD-L1:CD80 Cis-Heterodimer Triggers the Co-stimulatory Receptor CD28 While Repressing the Inhibitory PD-1 and CTLA-4 Pathways. Immunity 2019; 51:1059-1073.e9. [PMID: 31757674 PMCID: PMC6935268 DOI: 10.1016/j.immuni.2019.11.003] [Citation(s) in RCA: 209] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 08/26/2019] [Accepted: 11/05/2019] [Indexed: 12/13/2022]
Abstract
Combined immunotherapy targeting the immune checkpoint receptors cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1), or CTLA-4 and the PD-1 ligand (PD-L1) exhibits superior anti-tumor responses compared with single-agent therapy. Here, we examined the molecular basis for this synergy. Using reconstitution assays with fluorescence readouts, we found that PD-L1 and the CTLA-4 ligand CD80 heterodimerize in cis but not trans. Quantitative biochemistry and cell biology assays revealed that PD-L1:CD80 cis-heterodimerization inhibited both PD-L1:PD-1 and CD80:CTLA-4 interactions through distinct mechanisms but preserved the ability of CD80 to activate the T cell co-stimulatory receptor CD28. Furthermore, PD-L1 expression on antigen-presenting cells (APCs) prevented CTLA-4-mediated trans-endocytosis of CD80. Atezolizumab (anti-PD-L1), but not anti-PD-1, reduced cell surface expression of CD80 on APCs, and this effect was negated by co-blockade of CTLA-4 with ipilimumab (anti-CTLA-4). Thus, PD-L1 exerts an immunostimulatory effect by repressing the CTLA-4 axis; this has implications to the synergy of anti-PD-L1 and anti-CTLA-4 combination therapy.
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Affiliation(s)
- Yunlong Zhao
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Calvin K Lee
- Department of Pathology, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chia-Hao Lin
- Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Rodrigo B Gassen
- Pontificia Universidade Catolica do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Xiaozheng Xu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zhe Huang
- Department of Immunology and Microbiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Changchun Xiao
- Department of Immunology and Microbiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Cristina Bonorino
- Department of Surgery, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Departamento de Ciências Básicas da Saúde Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brasil
| | - Li-Fan Lu
- Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jack D Bui
- Department of Pathology, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093, USA
| | - Enfu Hui
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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19
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Cooperation between somatic mutation and germline-encoded residues enables antibody recognition of HIV-1 envelope glycans. PLoS Pathog 2019; 15:e1008165. [PMID: 31841553 PMCID: PMC6936856 DOI: 10.1371/journal.ppat.1008165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 12/30/2019] [Accepted: 10/29/2019] [Indexed: 11/19/2022] Open
Abstract
Viral glycoproteins are a primary target for host antibody responses. However, glycans on viral glycoproteins can hinder antibody recognition since they are self glycans derived from the host biosynthesis pathway. During natural HIV-1 infection, neutralizing antibodies are made against glycans on HIV-1 envelope glycoprotein (Env). However, such antibodies are rarely elicited with vaccination. Previously, the vaccine-induced, macaque antibody DH501 was isolated and shown to bind to high mannose glycans on HIV-1 Env. Understanding how DH501 underwent affinity maturation to recognize glycans could inform vaccine induction of HIV-1 glycan antibodies. Here, we show that DH501 Env glycan reactivity is mediated by both germline-encoded residues that contact glycans, and somatic mutations that increase antibody paratope flexibility. Only somatic mutations in the heavy chain were required for glycan reactivity. The paratope conformation was fragile as single mutations within the immunoglobulin fold or complementarity determining regions were sufficient for eliminating antibody function. Taken together, the initial germline VHDJH rearrangement generated contact residues capable of binding glycans, and somatic mutations were required to form a flexible paratope with a cavity conducive to HIV-1 envelope glycan binding. The requirement for the presence of most somatic mutations across the heavy chain variable region provides one explanation for the difficulty in inducing anti-Env glycan antibodies with HIV-1 Env vaccination. The viral pathogen HIV-1 uses sugar molecules, called glycans, from the host to densely cover its envelope protein. Most broadly neutralizing HIV-1 antibodies interact with glycans on the HIV-1 envelope protein. For this reason, the vaccine induction of anti-HIV-1 glycan antibodies is a principal goal. Since vaccine-induced anti-HIV-1 glycan antibodies are rare, it has not been determined how antibodies develop during vaccination to recognize HIV-1 glycans. Here, we elucidated the amino acids required for a primate antibody induced by HIV-1 vaccination to interact with HIV envelope glycans. Genetic and functional analyses showed the putative antibody germline nucleotide sequence encoded amino acids that were required for glycan reactivity. Somatic mutation also introduced critical amino acids that were required for glycan recognition. Unusually, the somatic mutations were not required in order to form direct contacts with antigen, but instead functioned to improve antibody flexibility and to form its glycan binding site. These results define the molecular development of a vaccine-induced HIV-1 glycan antibody, providing insight into why vaccines rarely elicit antibodies against the glycans on the HIV-1 outer coat protein.
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20
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Salimi H, Johnson J, Flores MG, Zhang MS, O'Malley Y, Houtman JC, Schlievert PM, Haim H. The lipid membrane of HIV-1 stabilizes the viral envelope glycoproteins and modulates their sensitivity to antibody neutralization. J Biol Chem 2019; 295:348-362. [PMID: 31757809 DOI: 10.1074/jbc.ra119.009481] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/19/2019] [Indexed: 11/06/2022] Open
Abstract
The envelope glycoproteins (Envs) of HIV-1 are embedded in the cholesterol-rich lipid membrane of the virus. Chemical depletion of cholesterol from HIV-1 particles inactivates their infectivity. We observed that diverse HIV-1 strains exhibit a range of sensitivities to such treatment. Differences in sensitivity to cholesterol depletion could not be explained by variation in Env components known to interact with cholesterol, including the cholesterol-recognition motif and cytoplasmic tail of gp41. Using antibody-binding assays, measurements of virus infectivity, and analyses of lipid membrane order, we found that depletion of cholesterol from HIV-1 particles decreases the conformational stability of Env. It enhances exposure of partially cryptic epitopes on the trimer and increases sensitivity to structure-perturbing treatments such as antibodies and cold denaturation. Substitutions in the cholesterol-interacting motif of gp41 induced similar effects as depletion of cholesterol. Surface-acting agents, which are incorporated into the virus lipid membrane, caused similar effects as disruption of the Env-cholesterol interaction. Furthermore, substitutions in gp120 that increased structural stability of Env (i.e. induced a "closed" conformation of the trimer) increased virus resistance to cholesterol depletion and to the surface-acting agents. Collectively, these results indicate a critical contribution of the viral membrane to the stability of the Env trimer and to neutralization resistance against antibodies. Our findings suggest that the potency of poorly neutralizing antibodies, which are commonly elicited in vaccinated individuals, may be markedly enhanced by altering the lipid composition of the viral membrane.
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Affiliation(s)
- Hamid Salimi
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jacklyn Johnson
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Manuel G Flores
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Michael S Zhang
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Yunxia O'Malley
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jon C Houtman
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Patrick M Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
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21
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Zhao Y, Harrison DL, Song Y, Ji J, Huang J, Hui E. Antigen-Presenting Cell-Intrinsic PD-1 Neutralizes PD-L1 in cis to Attenuate PD-1 Signaling in T Cells. Cell Rep 2019; 24:379-390.e6. [PMID: 29996099 PMCID: PMC6093302 DOI: 10.1016/j.celrep.2018.06.054] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 05/07/2018] [Accepted: 06/12/2018] [Indexed: 12/23/2022] Open
Abstract
The PD-1 pathway, consisting of the co-inhibitory receptor PD-1 on T cells and its ligand (PD-L1) on antigen-presenting cells (APCs), is a major mechanism of tumor immune evasion. PD-1 and PD-L1 blockade antibodies have produced remarkable clinical activities against a subset of cancers. Binding between T cell-intrinsic PD-1 and APC-intrinsic PD-L1 triggers inhibitory signaling to attenuate the T cell response. Here, we report that PD-1 is co-expressed with PD-L1 on tumor cells and tumor-infiltrating APCs. Using reconstitution and cell culture assays, we demonstrate that the co-expressed PD-1 binds to PD-L1 in cis. Such interaction inhibits the ability of PD-L1 to bind T cell-intrinsic PD-1 in trans and, in turn, represses canonical PD-L1/PD-1 inhibitory signaling. Selective blockade of tumor-intrinsic PD-1 frees up tumor-intrinsic PD-L1 to inhibit T cell signaling and cytotoxicity. Our study uncovers another dimension of PD-1 regulation, with important therapeutic implications.
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Affiliation(s)
- Yunlong Zhao
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Devin L Harrison
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Yuran Song
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jie Ji
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; Department of Hepatobiliary Surgery, The First Clinical Medical College of Nanjing Medical University Nanjing, Jiangsu 210029, China
| | - Jun Huang
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Enfu Hui
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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22
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Watanabe Y, Bowden TA, Wilson IA, Crispin M. Exploitation of glycosylation in enveloped virus pathobiology. Biochim Biophys Acta Gen Subj 2019; 1863:1480-1497. [PMID: 31121217 PMCID: PMC6686077 DOI: 10.1016/j.bbagen.2019.05.012] [Citation(s) in RCA: 315] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/13/2019] [Accepted: 05/17/2019] [Indexed: 12/12/2022]
Abstract
Glycosylation is a ubiquitous post-translational modification responsible for a multitude of crucial biological roles. As obligate parasites, viruses exploit host-cell machinery to glycosylate their own proteins during replication. Viral envelope proteins from a variety of human pathogens including HIV-1, influenza virus, Lassa virus, SARS, Zika virus, dengue virus, and Ebola virus have evolved to be extensively glycosylated. These host-cell derived glycans facilitate diverse structural and functional roles during the viral life-cycle, ranging from immune evasion by glycan shielding to enhancement of immune cell infection. In this review, we highlight the imperative and auxiliary roles glycans play, and how specific oligosaccharide structures facilitate these functions during viral pathogenesis. We discuss the growing efforts to exploit viral glycobiology in the development of anti-viral vaccines and therapies.
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Affiliation(s)
- Yasunori Watanabe
- School of Biological Sciences and Institute of Life Sciences, University of Southampton, Southampton SO17 1BJ, UK; Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Oxford OX3 7BN, UK; Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Thomas A Bowden
- Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Oxford OX3 7BN, UK
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Max Crispin
- School of Biological Sciences and Institute of Life Sciences, University of Southampton, Southampton SO17 1BJ, UK.
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23
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Abstract
Neutralizing antibodies against human immunodeficiency virus subtype 1 (HIV-1) bind to its envelope glycoprotein (Env). Half of the molecular mass of Env is carbohydrate making it one of the most heavily glycosylated proteins known in nature. HIV-1 Env glycans are derived from the host and present a formidable challenge for host anti-glycan antibody induction. Anti-glycan antibody induction is challenging because anti-HIV-1 glycan antibodies should recognize Env antigen while not acquiring autoreactivity. Thus, the glycan network on HIV-1 Env is referred to as the glycan shield. Despite the challenges presented by immune recognition of host-derived glycans, neutralizing antibodies capable of binding the glycans on HIV-1 Env can be generated by the host immune system in the setting of HIV-1 infection. In particular, a cluster of high mannose glycans, including an N-linked glycan at position 332, form the high mannose patch and are targeted by a variety of broadly neutralizing antibodies. These high mannose patch-directed HIV-1 antibodies can be categorized into distinct categories based on their antibody paratope structure, neutralization activity, and glycan and peptide reactivity. Below we will compare and contrast each of these classes of HIV-1 glycan-dependent antibodies and describe vaccine design efforts to elicit each of these antibody types.
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24
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Seabright GE, Doores KJ, Burton DR, Crispin M. Protein and Glycan Mimicry in HIV Vaccine Design. J Mol Biol 2019; 431:2223-2247. [PMID: 31028779 PMCID: PMC6556556 DOI: 10.1016/j.jmb.2019.04.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/12/2019] [Accepted: 04/13/2019] [Indexed: 01/30/2023]
Abstract
Antigenic mimicry is a fundamental tenet of structure-based vaccinology. Vaccine strategies for the human immunodeficiency virus type 1 (HIV-1) focus on the mimicry of its envelope spike (Env) due to its exposed location on the viral membrane and role in mediating infection. However, the virus has evolved to minimize the immunogenicity of conserved epitopes on the envelope spike. This principle is starkly illustrated by the presence of an extensive array of host-derived glycans, which act to shield the underlying protein from antibody recognition. Despite these hurdles, a subset of HIV-infected individuals eventually develop broadly neutralizing antibodies that recognize these virally presented glycans. Effective HIV-1 immunogens are therefore likely to involve some degree of mimicry of both the protein and glycan components of Env. As such, considerable efforts have been made to characterize the structure of the envelope spike and its glycan shield. This review summarizes the recent progress made in this field, with an emphasis on our growing understanding of the factors shaping the glycan shield of Env derived from both virus and soluble immunogens. We argue that recombinant mimics of the envelope spike are currently capable of capturing many features of the native viral glycan shield. Finally, we explore strategies through which the immunogenicity of Env glycans may be enhanced in the development of future immunogens.
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Affiliation(s)
- Gemma E Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK; School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Katie J Doores
- Department of Infectious Diseases, King's College London, Guy's Hospital, London, SE1 9RT, UK
| | - Dennis R Burton
- Department of Immunology and Microbiology, the Scripps Centre for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), International AIDS Vaccine Initiative Neutralizing Antibody Centre, Scripps Research, La Jolla, CA 92037, USA
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK; Department of Immunology and Microbiology, the Scripps Centre for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), International AIDS Vaccine Initiative Neutralizing Antibody Centre, Scripps Research, La Jolla, CA 92037, USA.
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25
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Antibody responses to viral infections: a structural perspective across three different enveloped viruses. Nat Microbiol 2019; 4:734-747. [PMID: 30886356 PMCID: PMC6818971 DOI: 10.1038/s41564-019-0392-y] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 01/29/2019] [Indexed: 02/07/2023]
Abstract
Antibodies serve as critical barriers to viral infection. Humoral immunity to a virus is achieved through the dual role of antibodies in communicating the presence of invading pathogens in infected cells to effector cells and interfering with processes essential to the viral lifecycle, chiefly entry into the host cell. For individuals that successfully control infection, virus-elicited antibodies can provide lifelong surveillance and protection from future insults. One approach to understand the nature of a successful immune response has been to utilize structural biology to uncover the molecular details of the antibodies derived from vaccines or natural infection and how they interact with their cognate microbial antigens. The ability to isolate antigen specific B-cells and rapidly solve structures of functional, monoclonal antibodies in complex with viral glycoprotein surface antigens has greatly expanded our knowledge of the sites of vulnerability on viruses. In this review, we compare the adaptive humoral immune responses to HIV, influenza, and filoviruses, with a particular focus on neutralizing antibodies. The pathogenesis of each of these viruses is quite different, providing an opportunity for comparison of immune responses: HIV causes a persistent, chronic infection; influenza an acute infection with multiple exposures during a lifetime and annual vaccination; and filoviruses, a virulent, acute infection. Neutralizing antibodies that develop under these different constraints are therefore sentinels that can provide insight into the underlying humoral immune responses and important lessons to guide future development of vaccines and immunotherapeutics.
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26
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Nguyen DN, Xu B, Stanfield RL, Bailey JK, Horiya S, Temme JS, Leon DR, LaBranche CC, Montefiori DC, Costello CE, Wilson IA, Krauss IJ. Oligomannose Glycopeptide Conjugates Elicit Antibodies Targeting the Glycan Core Rather than Its Extremities. ACS CENTRAL SCIENCE 2019; 5:237-249. [PMID: 30834312 PMCID: PMC6396197 DOI: 10.1021/acscentsci.8b00588] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Indexed: 06/01/2023]
Abstract
Up to ∼20% of HIV-infected individuals eventually develop broadly neutralizing antibodies (bnAbs), and many of these antibodies (∼40%) target a region of dense high-mannose glycosylation on gp120 of the HIV envelope protein, known as the "high-mannose patch" (HMP). Thus, there have been numerous attempts to develop glycoconjugate vaccine immunogens that structurally mimic the HMP and might elicit bnAbs targeting this conserved neutralization epitope. Herein, we report on the immunogenicity of glycopeptides, designed by in vitro selection, that bind tightly to anti-HMP antibody 2G12. By analyzing the fine carbohydrate specificity of rabbit antibodies elicited by these immunogens, we found that they differ from some natural human bnAbs, such as 2G12 and PGT128, in that they bind primarily to the core structures within the glycan, rather than to the Manα1 → 2Man termini (2G12) or to the whole glycan (PGT128). Antibody specificity for the glycan core may result from extensive serum mannosidase trimming of the immunogen in the vaccinated animals. This finding has broad implications for vaccine design aiming to target glycan-dependent HIV neutralizing antibodies.
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Affiliation(s)
- Dung N. Nguyen
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Bokai Xu
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Robyn L. Stanfield
- Department
of Integrative Structural and Computational Biology and the Skaggs
Institute for Chemical Biology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Jennifer K. Bailey
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Satoru Horiya
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - J. Sebastian Temme
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Deborah R. Leon
- Department
of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02215, United States
| | - Celia C. LaBranche
- Department
of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - David C. Montefiori
- Department
of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Catherine E. Costello
- Department
of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02215, United States
| | - Ian A. Wilson
- Department
of Integrative Structural and Computational Biology and the Skaggs
Institute for Chemical Biology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Isaac J. Krauss
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
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27
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Sun L, Ishihara M, Middleton DR, Tiemeyer M, Avci FY. Metabolic labeling of HIV-1 envelope glycoprotein gp120 to elucidate the effect of gp120 glycosylation on antigen uptake. J Biol Chem 2018; 293:15178-15194. [PMID: 30115684 DOI: 10.1074/jbc.ra118.004798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/12/2018] [Indexed: 12/21/2022] Open
Abstract
The glycan shield on the envelope glycoprotein gp120 of HIV-1 has drawn immense attention as a vulnerable site for broadly neutralizing antibodies and for its significant impact on host adaptive immune response to HIV-1. Glycosylation sites and glycan composition/structure at each site on gp120 along with the interactions of gp120 glycan shield with broadly neutralizing antibodies have been extensively studied. However, a method for directly and selectively tracking gp120 glycans has been lacking. Here, we integrate metabolic labeling and click chemistry technology with recombinant gp120 expression to demonstrate that gp120 glycans could be specifically labeled and directly detected. Selective labeling of gp120 by N-azidoacetylmannosamine (ManNAz) and N-azidoacetylgalactosamine (GalNAz) incorporation into the gp120 glycan shield was characterized by MS of tryptic glycopeptides. By using metabolically labeled gp120, we investigated the impact of gp120 glycosylation on its interaction with host cells and demonstrated that oligomannose enrichment and sialic acid deficiency drastically enhanced gp120 uptake by bone marrow-derived dendritic cells. Collectively, our data reveal an effective labeling and detection method for gp120, serving as a tool for functional characterization of the gp120 glycans and potentially other glycosylated proteins.
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Affiliation(s)
- Lina Sun
- From the Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and
| | - Mayumi Ishihara
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Dustin R Middleton
- From the Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and
| | - Michael Tiemeyer
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Fikri Y Avci
- From the Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and .,Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
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28
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Byrne G, O’Rourke SM, Alexander DL, Yu B, Doran RC, Wright M, Chen Q, Azadi P, Berman PW. CRISPR/Cas9 gene editing for the creation of an MGAT1-deficient CHO cell line to control HIV-1 vaccine glycosylation. PLoS Biol 2018; 16:e2005817. [PMID: 30157178 PMCID: PMC6133382 DOI: 10.1371/journal.pbio.2005817] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 09/11/2018] [Accepted: 08/21/2018] [Indexed: 01/21/2023] Open
Abstract
Over the last decade, multiple broadly neutralizing monoclonal antibodies (bN-mAbs) to the HIV-1 envelope protein (Env) gp120 have been described. Many of these recognize epitopes consisting of both amino acid and glycan residues. Moreover, the glycans required for binding of these bN-mAbs are early intermediates in the N-linked glycosylation pathway. This type of glycosylation substantially alters the mass and net charge of Envs compared to molecules with the same amino acid sequence but possessing mature, complex (sialic acid-containing) carbohydrates. Since cell lines suitable for biopharmaceutical production that limit N-linked glycosylation to mannose-5 (Man5) or earlier intermediates are not readily available, the production of vaccine immunogens displaying these glycan-dependent epitopes has been challenging. Here, we report the development of a stable suspension-adapted Chinese hamster ovary (CHO) cell line that limits glycosylation to Man5 and earlier intermediates. This cell line was created using the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing system and contains a mutation that inactivates the gene encoding Mannosyl (Alpha-1,3-)-Glycoprotein Beta-1,2-N-Acetylglucosaminyltransferase (MGAT1). Monomeric gp120s produced in the MGAT1- CHO cell line exhibit improved binding to prototypic glycan-dependent bN-mAbs directed to the V1/V2 domain (e.g., PG9) and the V3 stem (e.g., PGT128 and 10-1074) while preserving the structure of the important glycan-independent epitopes (e.g., VRC01). The ability of the MGAT1- CHO cell line to limit glycosylation to early intermediates in the N-linked glycosylation pathway without impairing the doubling time or ability to grow at high cell densities suggests that it will be a useful substrate for the biopharmaceutical production of HIV-1 vaccine immunogens.
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Affiliation(s)
- Gabriel Byrne
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Sara M. O’Rourke
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - David L. Alexander
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Bin Yu
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Rachel C. Doran
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Meredith Wright
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Qiushi Chen
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Phillip W. Berman
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
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Qadir A, Riaz M, Saeed M, Shahzad-Ul-Hussan S. Potential targets for therapeutic intervention and structure based vaccine design against Zika virus. Eur J Med Chem 2018; 156:444-460. [PMID: 30015077 DOI: 10.1016/j.ejmech.2018.07.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/28/2018] [Accepted: 07/06/2018] [Indexed: 01/01/2023]
Abstract
Continuously increasing number of reports of Zika virus (ZIKV) infections and associated severe clinical manifestations, including autoimmune abnormalities and neurological disorders such as neonatal microcephaly and Guillain-Barré syndrome have created alarming situation in various countries. To date, no specific antiviral therapy or vaccine is available against ZIKV. This review provides a comprehensive insight into the potential therapeutic targets and describes viral epitopes of broadly neutralizing antibodies (bNAbs) in vaccine design perspective. Interactions between ZIKV envelope glycoprotein E and cellular receptors mediate the viral fusion and entry to the target cell. Blocking these interactions by targeting cellular receptors or viral structural proteins mediating these interactions or viral surface glycans can inhibit viral entry to the cell. Similarly, different non-structural proteins of ZIKV and un-translated regions (UTRs) of its RNA play essential roles in viral replication cycle and potentiate for therapeutic interventions. Structure based vaccine design requires identity and structural description of the epitopes of bNAbs. We have described different conserved bNAb epitopes present in the ZIKV envelope as potential targets for structure based vaccine design. This review also highlights successes, unanswered questions and future perspectives in relation to therapeutic and vaccine development against ZIKV.
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Affiliation(s)
- Amina Qadir
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, 54792, Pakistan
| | - Muhammad Riaz
- Department of Chemistry, University of Azad Jammu & Kashmir, Muzaffarabad, Pakistan
| | - Muhammad Saeed
- Department of Chemistry and Chemical Engineering, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, 54792, Pakistan.
| | - Syed Shahzad-Ul-Hussan
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, 54792, Pakistan.
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Watanabe Y, Vasiljevic S, Allen JD, Seabright GE, Duyvesteyn HME, Doores KJ, Crispin M, Struwe WB. Signature of Antibody Domain Exchange by Native Mass Spectrometry and Collision-Induced Unfolding. Anal Chem 2018; 90:7325-7331. [PMID: 29757629 PMCID: PMC6008249 DOI: 10.1021/acs.analchem.8b00573] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The development of domain-exchanged antibodies offers a route to high-affinity targeting to clustered multivalent epitopes, such as those associated with viral infections and many cancers. One strategy to generate these antibodies is to introduce mutations into target antibodies to drive domain exchange using the only known naturally occurring domain-exchanged anti-HIV (anti-human immunodeficiency virus) IgG1 antibody, 2G12 , as a template. Here, we show that domain exchange can be sensitively monitored by ion-mobility mass spectrometry and gas-phase collision-induced unfolding. Using native 2G12 and a mutated form that disrupts domain exchange such that it has a canonical IgG1 architecture ( 2G12 I19R ), we show that the two forms can be readily distinguished by their unfolding profiles. Importantly, the same signature of domain exchange is observed for both intact antibody and isolated Fab fragments. The development of a mass spectrometric method to detect antibody domain exchange will enable rapid screening and selection of candidate antibodies engineered to exhibit this and other unusual quaternary antibody architectures.
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Affiliation(s)
- Yasunori Watanabe
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, OX1 3QU, United Kingdom
- Biological Sciences & the Institute for Life Sciences, University of Southampton, SO17 1BJ, United Kingdom
- Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Roosevelt Drive, OX3 7BN, United Kingdom
| | - Snezana Vasiljevic
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, OX1 3QU, United Kingdom
| | - Joel D. Allen
- Biological Sciences & the Institute for Life Sciences, University of Southampton, SO17 1BJ, United Kingdom
| | - Gemma E. Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, OX1 3QU, United Kingdom
- Biological Sciences & the Institute for Life Sciences, University of Southampton, SO17 1BJ, United Kingdom
| | - Helen M. E. Duyvesteyn
- Division of Structural Biology, University of Oxford, Wellcome Centre for Human Genetics, Roosevelt Drive, OX3 7BN, United Kingdom
| | - Katie J. Doores
- Department of Infectious Diseases, King’s College London, SE1 9RT, United Kingdom
| | - Max Crispin
- Biological Sciences & the Institute for Life Sciences, University of Southampton, SO17 1BJ, United Kingdom
| | - Weston B. Struwe
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, OX1 3QU, United Kingdom
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, OX1 3QZ, United Kingdom
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31
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Restricted HIV-1 Env glycan engagement by lectin-reengineered DAVEI protein chimera is sufficient for lytic inactivation of the virus. Biochem J 2018; 475:931-957. [PMID: 29343613 DOI: 10.1042/bcj20170662] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 12/28/2017] [Accepted: 01/17/2018] [Indexed: 12/28/2022]
Abstract
We previously reported a first-generation recombinant DAVEI construct, a dual action virus entry inhibitor composed of cyanovirin-N (CVN) fused to a membrane proximal external region or its derivative peptide Trp3. DAVEI exhibits potent and irreversible inactivation of HIV-1 (human immunodeficiency virus) viruses by dual engagement of gp120 and gp41. However, the promiscuity of CVN to associate with multiple glycosylation sites in gp120 and its multivalency limit current understanding of the molecular arrangement of the DAVEI molecules on trimeric spike. Here, we constructed and investigated the virolytic function of second-generation DAVEI molecules using a simpler lectin, microvirin (MVN). MVN is a monovalent lectin with a single glycan-binding site in gp120, is structurally similar to CVN and exhibits no toxicity or mitogenicity, both of which are liabilities with CVN. We found that, like CVN-DAVEI-L2-3Trp (peptide sequence DKWASLWNW), MVN-DAVEI2-3Trp exploits a similar mechanism of action for inducing HIV-1 lytic inactivation, but by more selective gp120 glycan engagement. By sequence redesign, we significantly increased the potency of MVN-DAVEI2-3Trp protein. Unlike CVN-DAVEI2-3Trp, re-engineered MVN-DAVEI2-3Trp(Q81K/M83R) virolytic activity and its interaction with gp120 were both competed by 2G12 antibody. That the lectin domain in DAVEIs can utilize MVN without loss of virolytic function argues that restricted HIV-1 Env (envelope glycoprotein) glycan engagement is sufficient for virolysis. It also shows that DAVEI lectin multivalent binding with gp120 is not required for virolysis. MVN-DAVEI2-3Trp(Q81K/M83R) provides an improved tool to elucidate productive molecular arrangements of Env-DAVEI enabling virolysis and also opens the way to form DAVEI fusions made up of gp120-binding small molecules linked to Trp3 peptide.
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Saunders KO, Nicely NI, Wiehe K, Bonsignori M, Meyerhoff RR, Parks R, Walkowicz WE, Aussedat B, Wu NR, Cai F, Vohra Y, Park PK, Eaton A, Go EP, Sutherland LL, Scearce RM, Barouch DH, Zhang R, Von Holle T, Overman RG, Anasti K, Sanders RW, Moody MA, Kepler TB, Korber B, Desaire H, Santra S, Letvin NL, Nabel GJ, Montefiori DC, Tomaras GD, Liao HX, Alam SM, Danishefsky SJ, Haynes BF. Vaccine Elicitation of High Mannose-Dependent Neutralizing Antibodies against the V3-Glycan Broadly Neutralizing Epitope in Nonhuman Primates. Cell Rep 2017; 18:2175-2188. [PMID: 28249163 DOI: 10.1016/j.celrep.2017.02.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/19/2016] [Accepted: 01/30/2017] [Indexed: 12/26/2022] Open
Abstract
Induction of broadly neutralizing antibodies (bnAbs) that target HIV-1 envelope (Env) is a goal of HIV-1 vaccine development. A bnAb target is the Env third variable loop (V3)-glycan site. To determine whether immunization could induce antibodies to the V3-glycan bnAb binding site, we repetitively immunized macaques over a 4-year period with an Env expressing V3-high mannose glycans. Env immunizations elicited plasma antibodies that neutralized HIV-1 expressing only high-mannose glycans-a characteristic shared by early bnAb B cell lineage members. A rhesus recombinant monoclonal antibody from a vaccinated macaque bound to the V3-glycan site at the same amino acids as broadly neutralizing antibodies. A structure of the antibody bound to glycan revealed that the three variable heavy-chain complementarity-determining regions formed a cavity into which glycan could insert and neutralized multiple HIV-1 isolates with high-mannose glycans. Thus, HIV-1 Env vaccination induced mannose-dependent antibodies with characteristics of V3-glycan bnAb precursors.
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Affiliation(s)
- Kevin O Saunders
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
| | - Nathan I Nicely
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kevin Wiehe
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mattia Bonsignori
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - R Ryan Meyerhoff
- Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Robert Parks
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Baptiste Aussedat
- Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA
| | - Nelson R Wu
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Fangping Cai
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yusuf Vohra
- Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA
| | - Peter K Park
- Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA
| | - Amanda Eaton
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Eden P Go
- University of Kansas, Lawrence, KS 66045, USA
| | - Laura L Sutherland
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Richard M Scearce
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Dan H Barouch
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Ruijun Zhang
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Tarra Von Holle
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - R Glenn Overman
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kara Anasti
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Rogier W Sanders
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - M Anthony Moody
- Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | | | | | | | | | | | | | - David C Montefiori
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Georgia D Tomaras
- Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA; Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hua-Xin Liao
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - S Munir Alam
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Barton F Haynes
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
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Abstract
HIV employs multiple means to evade the humoral immune response, particularly the elicitation of and recognition by broadly neutralizing antibodies (bnAbs). Such antibodies can act antivirally against a wide spectrum of viruses by targeting relatively conserved regions on the surface HIV envelope trimer spike. Elicitation of and recognition by bnAbs are hindered by the arrangement of spikes on virions and the relatively difficult access to bnAb epitopes on spikes, including the proximity of variable regions and a high density of glycans. Yet, in a small proportion of HIV-infected individuals, potent bnAb responses do develop, and isolation of the corresponding monoclonal antibodies has been facilitated by identification of favorable donors with potent bnAb sera and by development of improved methods for human antibody generation. Molecular studies of recombinant Env trimers, alone and in interaction with bnAbs, are providing new insights that are fueling the development and testing of promising immunogens aimed at the elicitation of bnAbs.
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Affiliation(s)
- Dennis R Burton
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037; , .,Neutralizing Antibody Center, International AIDS Vaccine Initiative, The Scripps Research Institute, La Jolla, California 92037.,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University; Boston, Massachusetts 02142
| | - Lars Hangartner
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037; , .,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037
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Interrogation of side chain biases for oligomannose recognition by antibody 2G12 via structure-guided phage display libraries. Bioorg Med Chem 2017; 25:5790-5798. [PMID: 28947103 DOI: 10.1016/j.bmc.2017.09.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/01/2017] [Accepted: 09/09/2017] [Indexed: 12/19/2022]
Abstract
Monoclonal antibodies (mAbs) are essential reagents for deciphering gene or protein function and have been a fruitful source of therapeutic and diagnostic agents. However, developing anticarbohydrate antibodies to target glycans for those purposes has been less successful because the molecular basis for glycan-mAb interactions is poorly understood relative to protein- or peptide-binding mAbs. Here, we report our investigation on glycan-mAb interactions by using the unique architectural scaffold of 2G12, an antibody that targets oligomannoses on the HIV-1 glycoprotein gp120, as the template for engineering highly specific mAbs to target glycans. We first analyzed 24 different X-ray structures of antiglycan mAbs from the Protein Data Bank to determine side chain amino acid distributions in of glycan-mAb interactions. We identified Tyr, Arg, Asn, Ser, Asp, and His as the six most prevalent residues in the glycan-mAb contacts. We then utilized this information to construct two phage display libraries ("Lib1" and "Lib2") in which positions on the heavy chain variable domains of 2G12 were allowed to vary in restricted manner among Tyr, Asp, Ser, His, Asn, Thr, Ala and Pro to interrogate the minimal physicochemical requirements for oligomannose recognition. We analyzed the sequences of 39 variants from Lib1 and 14 variants from Lib2 following selection against gp120, the results showed that there is a high degree of malleability within the 2G12 for glycan recognitions. We further characterized five unique phage clones from both libraries that exhibited a gp120-specific binding profile. Expression of two of these variants as soluble mAbs indicated that, while specificity of gp120-binding was retained, the affinity of these mutants was significantly reduced relative to WT 2G12. Nonetheless, the results indicate these is some malleability in the identity of contact residues and provide a novel insight into the nature of glycan-antibody interactions and how they may differ from protein-antibody binding interactions.
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Behrens AJ, Seabright GE, Crispin M. Targeting Glycans of HIV Envelope Glycoproteins for Vaccine Design. CHEMICAL BIOLOGY OF GLYCOPROTEINS 2017. [DOI: 10.1039/9781782623823-00300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The surface of the envelope spike of the human immunodeficiency virus (HIV) is covered with a dense array of glycans, which is sufficient to impede the host antibody response while maintaining a window for receptor recognition. The glycan density significantly exceeds that typically observed on self glycoproteins and is sufficiently high to disrupt the maturation process of glycans, from oligomannose- to complex-type glycosylation, that normally occurs during glycoprotein transit through the secretory system. It is notable that this generates a degree of homogeneity not seen in the highly mutated protein moiety. The conserved, close glycan packing and divergences from default glycan processing give a window for immune recognition. Encouragingly, in a subset of individuals, broadly neutralizing antibodies (bNAbs) have been isolated that recognize these features and are protective in passive-transfer models. Here, we review the recent advances in our understanding of the glycan shield of HIV and outline the strategies that are being pursued to elicit glycan-binding bNAbs by vaccination.
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Affiliation(s)
- Anna-Janina Behrens
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford South Parks Road Oxford OX1 3QU UK
| | - Gemma E. Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford South Parks Road Oxford OX1 3QU UK
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford South Parks Road Oxford OX1 3QU UK
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Changes in Structure and Antigenicity of HIV-1 Env Trimers Resulting from Removal of a Conserved CD4 Binding Site-Proximal Glycan. J Virol 2016; 90:9224-36. [PMID: 27489265 DOI: 10.1128/jvi.01116-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/27/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED The envelope glycoprotein (Env) is the major target for HIV-1 broadly neutralizing antibodies (bNAbs). One of the mechanisms that HIV has evolved to escape the host's immune response is to mask conserved epitopes on Env with dense glycosylation. Previous studies have shown that the removal of a particular conserved glycan at N197 increases the neutralization sensitivity of the virus to antibodies targeting the CD4 binding site (CD4bs), making it a site of significant interest from the perspective of vaccine design. At present, the structural consequences that result from the removal of the N197 glycan have not been characterized. Using native-like SOSIP trimers, we examine the effects on antigenicity and local structural dynamics resulting from the removal of this glycan. A large increase in the binding of CD4bs and V3-targeting antibodies is observed for the N197Q mutant in trimeric Env, while no changes are observed with monomeric gp120. While the overall structure and thermostability are not altered, a subtle increase in the flexibility of the variable loops at the trimeric interface of adjacent protomers is evident in the N197Q mutant by hydrogen-deuterium exchange mass spectrometry. Structural modeling of the glycan chains suggests that the spatial occupancy of the N197 glycan leads to steric clashes with CD4bs antibodies in the Env trimer but not monomeric gp120. Our results indicate that the removal of the N197 glycan enhances the exposure of relevant bNAb epitopes on Env with a minimal impact on the overall trimeric structure. These findings present a simple modification for enhancing trimeric Env immunogens in vaccines. IMPORTANCE The HIV-1 Env glycoprotein presents a dense patchwork of host cell-derived N-linked glycans. This so-called glycan shield is considered to be a major protective mechanism against immune recognition. While the positions of many N-linked glycans are isolate specific, some are highly conserved and are believed to play key functional roles. In this study, we examine the conserved, CD4 binding site-proximal N197 glycan and demonstrate that its removal both facilitates neutralizing antibody access to the CD4 binding site and modestly impacts the structural dynamics at the trimer crown without drastically altering global Env trimer stability. This indicates that surgical glycosylation site modification may be an effective way of sculpting epitope presentation in Env-based vaccines.
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Krauss IJ. Antibody recognition of HIV and dengue glycoproteins. Glycobiology 2016; 26:813-9. [PMID: 26941393 PMCID: PMC5018046 DOI: 10.1093/glycob/cww031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 02/12/2016] [Accepted: 02/29/2016] [Indexed: 01/13/2023] Open
Abstract
The last 6 years have witnessed an explosion of discoveries at the interface of glycobiology and immunology. Binding of clustered oligosaccharides has turned out to be a very frequent mode by which human antibodies have developed broadly neutralizing activity against HIV. This mini-review will cover many recent developments in the HIV antibody field, as well as emerging data about Dengue broadly neutralizing antibodies.
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Affiliation(s)
- Isaac J Krauss
- Department of Chemistry, Brandeis University, Waltham, MA 02454, USA
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38
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Liu CC, Zhai C, Zheng XJ, Ye XS. Altering the Specificity of the Antibody Response to HIV gp120 with a Glycoconjugate Antigen. ACS Chem Biol 2016; 11:1702-9. [PMID: 27088577 DOI: 10.1021/acschembio.6b00224] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Some conserved glycans on the HIV envelope protein are targets of broadly neutralizing antibodies (bnAbs) of HIV. BnAbs provide a precise definition of broadly neutralizing epitopes on the envelope protein of HIV. These epitopes are promising for vaccine design. Many glycan-related antigens with high affinity to bnAbs have been tested as immunogens in vivo. However, it was found that no bnAb-like antibodies were induced. Vaccination with different immunogens containing the same neutralizing epitope may enhance the affinity maturation of antibodies which focus on the shared epitope. This combined immunization strategy showed great potential in peptide epitope-based vaccine design. However, it has not yet been explored on glycan-related epitopes to date. Herein, we take 2G12 as a model to validate this strategy on glycan-related epitopes. A high-affinity antigen of 2G12 was constructed by conjugating the D1 arm tetramannoside to bovine serum albumin. Then, the glycoconjugate was coimmunized with a recombinant gp120, which was expected to selectively benefit the induction of antibodies recognizing the neutralizing epitope of 2G12 on gp120. Mice were inoculated with the two antigens simultaneously or alternately to determine the suitable regimen for this strategy. The serological assays demonstrated that the antibody titers and subtypes responded to the whole gp120 were not improved, and the proportion of antibodies competitively bound to the 2G12 epitope was not enhanced significantly either. However, the coimmunized glycoconjugate selectively raised the proportion of antibodies recognizing D1 arm tetramannoside-related structures on gp120. These results provide important experience for the design of glycan-dependent bnAb-based vaccines.
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Affiliation(s)
- Chang-Cheng Liu
- State Key Laboratory of Natural and Biomimetic Drugs,
School of Pharmaceutical Sciences, Peking University, Xue Yuan
Rd No. 38, Beijing 100191, China
| | - Canjia Zhai
- State Key Laboratory of Natural and Biomimetic Drugs,
School of Pharmaceutical Sciences, Peking University, Xue Yuan
Rd No. 38, Beijing 100191, China
| | - Xiu-Jing Zheng
- State Key Laboratory of Natural and Biomimetic Drugs,
School of Pharmaceutical Sciences, Peking University, Xue Yuan
Rd No. 38, Beijing 100191, China
| | - Xin-Shan Ye
- State Key Laboratory of Natural and Biomimetic Drugs,
School of Pharmaceutical Sciences, Peking University, Xue Yuan
Rd No. 38, Beijing 100191, China
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Dynamic Viral Glycoprotein Machines: Approaches for Probing Transient States That Drive Membrane Fusion. Viruses 2016; 8:v8010015. [PMID: 26761026 PMCID: PMC4728575 DOI: 10.3390/v8010015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/11/2015] [Accepted: 12/31/2015] [Indexed: 01/10/2023] Open
Abstract
The fusion glycoproteins that decorate the surface of enveloped viruses undergo dramatic conformational changes in the course of engaging with target cells through receptor interactions and during cell entry. These refolding events ultimately drive the fusion of viral and cellular membranes leading to delivery of the genetic cargo. While well-established methods for structure determination such as X-ray crystallography have provided detailed structures of fusion proteins in the pre- and post-fusion fusion states, to understand mechanistically how these fusion glycoproteins perform their structural calisthenics and drive membrane fusion requires new analytical approaches that enable dynamic intermediate states to be probed. Methods including structural mass spectrometry, small-angle X-ray scattering, and electron microscopy have begun to provide new insight into pathways of conformational change and fusion protein function. In combination, the approaches provide a significantly richer portrait of viral fusion glycoprotein structural variation and fusion activation as well as inhibition by neutralizing agents. Here recent studies that highlight the utility of these complementary approaches will be reviewed with a focus on the well-characterized influenza virus hemagglutinin fusion glycoprotein system.
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Doores KJ. The HIV glycan shield as a target for broadly neutralizing antibodies. FEBS J 2015; 282:4679-91. [PMID: 26411545 PMCID: PMC4950053 DOI: 10.1111/febs.13530] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 09/21/2015] [Accepted: 09/23/2015] [Indexed: 11/30/2022]
Abstract
The HIV envelope glycoprotein (Env) is the sole target for HIV broadly neutralizing antibodies (bnAbs). HIV Env is one of the most heavily glycosylated proteins known, with approximately half of its mass consisting of host-derived N-linked glycans. The high density of glycans creates a shield that impedes antibody recognition but, critically, some of the most potent and broadly active bnAbs have evolved to recognize epitopes formed by these glycans. Although the virus hijacks the host protein synthesis and glycosylation machinery to generate glycosylated HIV Env, studies have shown that HIV Env glycosylation diverges from that typically observed on host-derived glycoproteins. In particular, the high density of glycans leads to a nonself motif of underprocessed oligomannose-type glycans that forms the target of some of the most broad and potent HIV bnAbs. This review discusses the changing perception of the HIV glycan shield, and summarizes the protein-directed and cell-directed factors controlling HIV Env glycosylation that impact on HIV bnAb recognition and HIV vaccine design strategies.
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Affiliation(s)
- Katie J Doores
- Department of Infectious Diseases, Faculty of Life Sciences and Medicine, King's College London, Guy's Hospital, UK
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Design and structure of two HIV-1 clade C SOSIP.664 trimers that increase the arsenal of native-like Env immunogens. Proc Natl Acad Sci U S A 2015; 112:11947-52. [PMID: 26372963 DOI: 10.1073/pnas.1507793112] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A key challenge in the quest toward an HIV-1 vaccine is design of immunogens that can generate a broadly neutralizing antibody (bnAb) response against the enormous sequence diversity of the HIV-1 envelope glycoprotein (Env). We previously demonstrated that a recombinant, soluble, fully cleaved SOSIP.664 trimer based on the clade A BG505 sequence is a faithful antigenic and structural mimic of the native trimer in its prefusion conformation. Here, we sought clade C native-like trimers with comparable properties. We identified DU422 and ZM197M SOSIP.664 trimers as being appropriately thermostable (Tm of 63.4 °C and 62.7 °C, respectively) and predominantly native-like, as determined by negative-stain electron microscopy (EM). Size exclusion chromatography, ELISA, and surface plasmon resonance further showed that these trimers properly display epitopes for all of the major bnAb classes, including quaternary-dependent, trimer-apex (e.g., PGT145) and gp120/gp41 interface (e.g., PGT151) epitopes. A cryo-EM reconstruction of the ZM197M SOSIP.664 trimer complexed with VRC01 Fab against the CD4 binding site at subnanometer resolution revealed a striking overall similarity to its BG505 counterpart with expected local conformational differences in the gp120 V1, V2, and V4 loops. These stable clade C trimers contribute additional diversity to the pool of native-like Env immunogens as key components of strategies to induce bnAbs to HIV-1.
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Influences on the Design and Purification of Soluble, Recombinant Native-Like HIV-1 Envelope Glycoprotein Trimers. J Virol 2015; 89:12189-210. [PMID: 26311893 DOI: 10.1128/jvi.01768-15] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 08/20/2015] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED We have investigated factors that influence the production of native-like soluble, recombinant trimers based on the env genes of two isolates of human immunodeficiency virus type 1 (HIV-1), specifically 92UG037.8 (clade A) and CZA97.012 (clade C). When the recombinant trimers based on the env genes of isolates 92UG037.8 and CZA97.012 were made according to the SOSIP.664 design and purified by affinity chromatography using broadly neutralizing antibodies (bNAbs) against quaternary epitopes (PGT145 and PGT151, respectively), the resulting trimers are highly stable and they are fully native-like when visualized by negative-stain electron microscopy. They also have a native-like (i.e., abundant) oligomannose glycan composition and display multiple bNAb epitopes while occluding those for nonneutralizing antibodies. In contrast, uncleaved, histidine-tagged Foldon (Fd) domain-containing gp140 proteins (gp140UNC-Fd-His), based on the same env genes, very rarely form native-like trimers, a finding that is consistent with their antigenic and biophysical properties and glycan composition. The addition of a 20-residue flexible linker (FL20) between the gp120 and gp41 ectodomain (gp41ECTO) subunits to make the uncleaved 92UG037.8 gp140-FL20 construct is not sufficient to create a native-like trimer, but a small percentage of native-like trimers were produced when an I559P substitution in gp41ECTO was also present. The further addition of a disulfide bond (SOS) to link the gp120 and gp41 subunits in the uncleaved gp140-FL20-SOSIP protein increases native-like trimer formation to ∼20 to 30%. Analysis of the disulfide bond content shows that misfolded gp120 subunits are abundant in uncleaved CZA97.012 gp140UNC-Fd-His proteins but very rare in native-like trimer populations. The design and stabilization method and the purification strategy are, therefore, all important influences on the quality of trimeric Env proteins and hence their suitability as vaccine components. IMPORTANCE Soluble, recombinant multimeric proteins based on the HIV-1 env gene are current candidate immunogens for vaccine trials in humans. These proteins are generally designed to mimic the native trimeric envelope glycoprotein (Env) that is the target of virus-neutralizing antibodies on the surfaces of virions. The underlying hypothesis is that an Env-mimetic protein may be able to induce antibodies that can neutralize the virus broadly and potently enough for a vaccine to be protective. Multiple different designs for Env-mimetic trimers have been put forth. Here, we used the CZA97.012 and 92UG037.8 env genes to compare some of these designs and determine which ones best mimic virus-associated Env trimers. We conclude that the most widely used versions of CZA97.012 and 92UG037.8 oligomeric Env proteins do not resemble the trimeric Env glycoprotein on HIV-1 viruses, which has implications for the design and interpretation of ongoing or proposed clinical trials of these proteins.
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Functional and Structural Characterization of Human V3-Specific Monoclonal Antibody 2424 with Neutralizing Activity against HIV-1 JRFL. J Virol 2015; 89:9090-102. [PMID: 26109728 PMCID: PMC4524078 DOI: 10.1128/jvi.01280-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/06/2015] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED The V3 region of HIV-1 gp120 is important for virus-coreceptor interaction and highly immunogenic. Although most anti-V3 antibodies neutralize only the sensitive tier 1 viruses, anti-V3 antibodies effective against the more resistant viruses exist, and a better understanding of these antibodies and their epitopes would be beneficial for the development of novel vaccine immunogens against HIV. The HIV-1 isolate JRFL with its cryptic V3 is resistant to most V3-specific monoclonal antibodies (MAbs). However, the V3 MAb 2424 achieves 100% neutralization against JRFL. 2424 is encoded by IGHV3-53 and IGLV2-28 genes, a pairing rarely used by the other V3 MAbs. 2424 also has distinct binding and neutralization profiles. Studies of 2424-mediated neutralization of JRFL produced with a mannosidase inhibitor further revealed that its neutralizing activity is unaffected by the glycan composition of the virus envelope. To understand the distinct activity of 2424, we determined the crystal structure of 2424 Fab in complex with a JRFL V3 peptide and showed that the 2424 epitope is located at the tip of the V3 crown ((307)IHIGPGRAFYT(319)), dominated by interactions with His(P308), Pro(P313), and Arg(P315). The binding mode of 2424 is similar to that of the well-characterized MAb 447-52D, although 2424 is more side chain dependent. The 2424 epitope is focused on the very apex of V3, away from nearby glycans, facilitating antibody access. This feature distinguishes the 2424 epitope from the other V3 crown epitopes and indicates that the tip of V3 is a potential site to target and incorporate into HIV vaccine immunogens. IMPORTANCE HIV/AIDS vaccines are crucial for controlling the HIV epidemics that continue to afflict millions of people worldwide. However, HIV vaccine development has been hampered by significant scientific challenges, one of which is the inability of HIV vaccine candidates evaluated thus far to elicit production of potent and broadly neutralizing antibodies. The V3 loop is one of the few immunogenic targets on the virus envelope glycoprotein that can induce neutralizing antibodies, but in many viruses, parts of V3 are inaccessible for antibody recognition. This study examined a V3-specific monoclonal antibody that can completely neutralize HIV-1 JRFL, a virus isolate resistant to most V3 antibodies. Our data reveal that this antibody recognizes the most distal tip of V3, which is not as occluded as other parts of V3. Hence, the epitope of 2424 is in one of the vulnerable sites on the virus that may be exploited in designing HIV vaccine immunogens.
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Pritchard LK, Spencer DIR, Royle L, Bonomelli C, Seabright GE, Behrens AJ, Kulp DW, Menis S, Krumm SA, Dunlop DC, Crispin DJ, Bowden TA, Scanlan CN, Ward AB, Schief WR, Doores KJ, Crispin M. Glycan clustering stabilizes the mannose patch of HIV-1 and preserves vulnerability to broadly neutralizing antibodies. Nat Commun 2015; 6:7479. [PMID: 26105115 PMCID: PMC4500839 DOI: 10.1038/ncomms8479] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 05/13/2015] [Indexed: 12/22/2022] Open
Abstract
The envelope spike of HIV-1 employs a ‘glycan shield’ to protect itself from antibody-mediated neutralization. Paradoxically, however, potent broadly neutralizing antibodies (bnAbs) have been isolated which target this shield. The unusually high glycan density on the gp120 subunit limits processing during biosynthesis, leaving a region of under-processed oligomannose-type structures which is a primary target of these bnAbs. Here we investigate the contribution of individual glycosylation sites to formation of this so-called intrinsic mannose patch. Deletion of individual sites has a limited effect on the overall size of the intrinsic mannose patch but leads to changes in the processing of neighboring glycans. These structural changes are largely tolerated by a panel of glycan-dependent bnAbs targeting these regions, indicating a degree of plasticity in their recognition. These results support the intrinsic mannose patch as a stable target for vaccine design.
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Affiliation(s)
- Laura K Pritchard
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | | | - Louise Royle
- Ludger Ltd., Culham Science Centre, Abingdon, Oxfordshire OX14 3EB, UK
| | - Camille Bonomelli
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Gemma E Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Anna-Janina Behrens
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Daniel W Kulp
- 1] Department of Immunology and Microbial Science and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA [2] Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Sergey Menis
- 1] Department of Immunology and Microbial Science and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA [2] Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Stefanie A Krumm
- King's College London School of Medicine at Guy's, King's and St Thomas' Hospitals, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK
| | - D Cameron Dunlop
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Daniel J Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Thomas A Bowden
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Christopher N Scanlan
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - William R Schief
- 1] Department of Immunology and Microbial Science and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California 92037, USA [2] Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California 92037, USA [3] Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts 02139, USA
| | - Katie J Doores
- King's College London School of Medicine at Guy's, King's and St Thomas' Hospitals, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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AlSalmi W, Mahalingam M, Ananthaswamy N, Hamlin C, Flores D, Gao G, Rao VB. A New Approach to Produce HIV-1 Envelope Trimers: BOTH CLEAVAGE AND PROPER GLYCOSYLATION ARE ESSENTIAL TO GENERATE AUTHENTIC TRIMERS. J Biol Chem 2015; 290:19780-95. [PMID: 26088135 PMCID: PMC4528139 DOI: 10.1074/jbc.m115.656611] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Indexed: 12/22/2022] Open
Abstract
The trimeric envelope spike of HIV-1 mediates virus entry into human cells. The exposed part of the trimer, gp140, consists of two noncovalently associated subunits, gp120 and gp41 ectodomain. A recombinant vaccine that mimics the native trimer might elicit entry-blocking antibodies and prevent virus infection. However, preparation of authentic HIV-1 trimers has been challenging. Recently, an affinity column containing the broadly neutralizing antibody 2G12 has been used to capture recombinant gp140 and prepare trimers from clade A BG505 that naturally produces stable trimers. However, this antibody-based approach may not be as effective for the diverse HIV-1 strains with different epitope signatures. Here, we report a new and simple approach to produce HIV-1 envelope trimers. The C terminus of gp140 was attached to Strep-tag II with a long linker separating the tag from the massive trimer base and glycan shield. This allowed capture of nearly homogeneous gp140 directly from the culture medium. Cleaved, uncleaved, and fully or partially glycosylated trimers from different clade viruses were produced. Extensive biochemical characterizations showed that cleavage of gp140 was not essential for trimerization, but it triggered a conformational change that channels trimers into correct glycosylation pathways, generating compact three-blade propeller-shaped trimers. Uncleaved trimers entered aberrant pathways, resulting in hyperglycosylation, nonspecific cross-linking, and conformational heterogeneity. Even the cleaved trimers showed microheterogeneity in gp41 glycosylation. These studies established a broadly applicable HIV-1 trimer production system as well as generating new insights into their assembly and maturation that collectively bear on the HIV-1 vaccine design.
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Affiliation(s)
- Wadad AlSalmi
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Marthandan Mahalingam
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Neeti Ananthaswamy
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Christopher Hamlin
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Dalia Flores
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Guofen Gao
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Venigalla B Rao
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
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46
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Pritchard LK, Vasiljevic S, Ozorowski G, Seabright GE, Cupo A, Ringe R, Kim HJ, Sanders RW, Doores KJ, Burton DR, Wilson IA, Ward AB, Moore JP, Crispin M. Structural Constraints Determine the Glycosylation of HIV-1 Envelope Trimers. Cell Rep 2015; 11:1604-13. [PMID: 26051934 DOI: 10.1016/j.celrep.2015.05.017] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 04/23/2015] [Accepted: 05/11/2015] [Indexed: 10/23/2022] Open
Abstract
A highly glycosylated, trimeric envelope glycoprotein (Env) mediates HIV-1 cell entry. The high density and heterogeneity of the glycans shield Env from recognition by the immune system, but paradoxically, many potent broadly neutralizing antibodies (bNAbs) recognize epitopes involving this glycan shield. To better understand Env glycosylation and its role in bNAb recognition, we characterized a soluble, cleaved recombinant trimer (BG505 SOSIP.664) that is a close structural and antigenic mimic of native Env. Large, unprocessed oligomannose-type structures (Man8-9GlcNAc2) are notably prevalent on the gp120 components of the trimer, irrespective of the mammalian cell expression system or the bNAb used for affinity purification. In contrast, gp41 subunits carry more highly processed glycans. The glycans on uncleaved, non-native oligomeric gp140 proteins are also highly processed. A homogeneous, oligomannose-dominated glycan profile is therefore a hallmark of a native Env conformation and a potential Achilles' heel that can be exploited for bNAb recognition and vaccine design.
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Affiliation(s)
- Laura K Pritchard
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Snezana Vasiljevic
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center and the collaboration for AIDS Vaccine Discovery, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Gemma E Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Albert Cupo
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, NY 10021, USA
| | - Rajesh Ringe
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, NY 10021, USA
| | - Helen J Kim
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center and the collaboration for AIDS Vaccine Discovery, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Rogier W Sanders
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, NY 10021, USA; 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
| | - Katie J Doores
- King's College London School of Medicine at Guy's, King's and St. Thomas' Hospitals, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK
| | - Dennis R Burton
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA 02142, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center and the collaboration for AIDS Vaccine Discovery, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center and the collaboration for AIDS Vaccine Discovery, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - John P Moore
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, NY 10021, USA
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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Sharma SK, de Val N, Bale S, Guenaga J, Tran K, Feng Y, Dubrovskaya V, Ward AB, Wyatt RT. Cleavage-independent HIV-1 Env trimers engineered as soluble native spike mimetics for vaccine design. Cell Rep 2015; 11:539-50. [PMID: 25892233 DOI: 10.1016/j.celrep.2015.03.047] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/11/2015] [Accepted: 03/20/2015] [Indexed: 12/22/2022] Open
Abstract
Viral glycoproteins mediate entry by pH-activated or receptor-engaged activation and exist in metastable pre-fusogenic states that may be stabilized by directed rational design. As recently reported, the conformationally fixed HIV-1 envelope glycoprotein (Env) trimers in the pre-fusion state (SOSIP) display molecular homogeneity and structural integrity at relatively high levels of resolution. However, the SOSIPs necessitate full Env precursor cleavage, which requires endogenous furin overexpression. Here, we developed an alternative strategy using flexible peptide covalent linkage of Env subdomains to produce soluble, homogeneous, and cleavage-independent Env mimics, called native flexibly linked (NFL) trimers, as vaccine candidates. This simplified design avoids the need for furin co-expression and, in one case, antibody affinity purification to accelerate trimer scale-up for preclinical and clinical applications. We have successfully translated the NFL design to multiple HIV-1 subtypes, establishing the potential to become a general method of producing native-like, well-ordered Env trimers for HIV-1 or other viruses.
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Affiliation(s)
- Shailendra Kumar Sharma
- IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Natalia de Val
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Shridhar Bale
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Javier Guenaga
- IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Karen Tran
- IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Yu Feng
- IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Viktoriya Dubrovskaya
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Andrew B Ward
- IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Richard T Wyatt
- IAVI Neutralizing Antibody Center at the Scripps Research Institute, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA.
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48
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Glycan Microheterogeneity at the PGT135 Antibody Recognition Site on HIV-1 gp120 Reveals a Molecular Mechanism for Neutralization Resistance. J Virol 2015; 89:6952-9. [PMID: 25878100 DOI: 10.1128/jvi.00230-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/01/2015] [Indexed: 12/16/2022] Open
Abstract
Broadly neutralizing antibodies have been isolated that bind the glycan shield of the HIV-1 envelope spike. One such antibody, PGT135, contacts the intrinsic mannose patch of gp120 at the Asn332, Asn392, and Asn386 glycosylation sites. Here, site-specific glycosylation analysis of recombinant gp120 revealed glycan microheterogeneity sufficient to explain the existence of a minor population of virions resistant to PGT135 neutralization. Target microheterogeneity and antibody glycan specificity are therefore important parameters in HIV-1 vaccine design.
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49
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Effects of the I559P gp41 change on the conformation and function of the human immunodeficiency virus (HIV-1) membrane envelope glycoprotein trimer. PLoS One 2015; 10:e0122111. [PMID: 25849367 PMCID: PMC4388519 DOI: 10.1371/journal.pone.0122111] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 02/20/2015] [Indexed: 12/21/2022] Open
Abstract
The mature human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer is produced by proteolytic cleavage of a precursor and consists of three gp120 exterior and three gp41 transmembrane subunits. The metastable Env complex is induced to undergo conformational changes required for virus entry by the binding of gp120 to the receptors, CD4 and CCR5/CXCR4. An isoleucine-to-proline change (I559P) in the gp41 ectodomain has been used to stabilize soluble forms of HIV-1 Env trimers for structural characterization and for use as immunogens. In the native membrane-anchored HIV-1BG505 Env, the I559P change modestly decreased proteolytic maturation, increased the non-covalent association of gp120 with the Env trimer, and resulted in an Env conformation distinctly different from that of the wild-type HIV-1BG505 Env. Compared with the wild-type Env, the I559P Env was recognized inefficiently by polyclonal sera from HIV-1-infected individuals, by several gp41-directed antibodies, by some antibodies against the CD4-binding site of gp120, and by antibodies that preferentially recognize the CD4-bound Env. Some of the gp120-associated antigenic differences between the wild-type HIV-1BG505 Env and the I559P mutant were compensated by the SOS disulfide bond between gp120 and gp41, which has been used to stabilize cleaved soluble Env trimers. Nonetheless, regardless of the presence of the SOS changes, Envs with proline 559 were recognized less efficiently than Envs with isoleucine 559 by the VRC01 neutralizing antibody, which binds the CD4-binding site of gp120, and the PGT151 neutralizing antibody, which binds a hybrid gp120-gp41 epitope. The I559P change completely eliminated the ability of the HIV-1BG505 Env to mediate cell-cell fusion and virus entry, and abolished the capacity of the SOS Env to support virus infection in the presence of a reducing agent. These results suggest that differences exist between the quaternary structures of functional Env spikes and I559P Envs.
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Mengistu M, Ray K, Lewis GK, DeVico AL. Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells. PLoS Pathog 2015; 11:e1004772. [PMID: 25807494 PMCID: PMC4373872 DOI: 10.1371/journal.ppat.1004772] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 03/02/2015] [Indexed: 12/17/2022] Open
Abstract
The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step. The elucidation of these epitope exposure patterns during viral entry will help clarify antibody-mediated inhibition of HIV-1 as it is measured in vitro and in vivo. A major strategy for blocking HIV-1 infection is to target antiviral antibodies or drugs to sites of vulnerability on the surface proteins of the virus. It is a relatively straightforward matter to explore these sites on the surfaces of free HIV-1 particles or on isolated viral envelope antigens. However, one difficulty presented by HIV-1 is that its surface proteins are flexible and change shape once the virus has attached to its host cell. To date, it has been difficult to predict how cell-bound HIV-1 exposes its sites of vulnerability. Yet the antiviral activities of certain antibodies indirectly suggest that there must be unique sites on cell-bound HIV-1 that are not found on free virus. Here, we use new techniques and tools to determine how HIV-1 exposes unique sites of vulnerability after attaching to host cells. We find that the virus exposes a remarkable array of these sites, including ones previously believed hidden. These exposure patterns explain the antiviral activities of various anti-HIV-1 antibodies and provide a new view of how HIV-1 might interact with the immune system. Our study also provides insights for how to target HIV-1 with antiviral antibodies, vaccines, or antiviral agents.
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Affiliation(s)
- Meron Mengistu
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (MM); (ALD)
| | - Krishanu Ray
- Center for Fluorescence Spectroscopy of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - George K. Lewis
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Anthony L. DeVico
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (MM); (ALD)
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