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Antigenicity-defined conformations of an extremely neutralization-resistant HIV-1 envelope spike. Proc Natl Acad Sci U S A 2017; 114:4477-4482. [PMID: 28396421 DOI: 10.1073/pnas.1700634114] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The extraordinary genetic diversity of the HIV-1 envelope spike [Env; trimeric (gp160)3, cleaved to (gp120/gp41)3] poses challenges for vaccine development. Envs of different clinical isolates exhibit different sensitivities to antibody-mediated neutralization. Envs of difficult-to-neutralize viruses are thought to be more stable and conformationally homogeneous trimers than those of easy-to-neutralize viruses, thereby providing more effective concealment of conserved, functionally critical sites. In this study we have characterized the antigenic properties of an Env derived from one of the most neutralization-resistant HIV-1 isolates, CH120.6. Sequence variation at neutralizing epitopes does not fully account for its exceptional resistance to antibodies. The full-length, membrane-bound CH120.6 Env is indeed stable and conformationally homogeneous. Its antigenicity correlates closely with its neutralization sensitivity, and major changes in antigenicity upon CD4 engagement appear to be restricted to the coreceptor site. The CH120.6 gp140 trimer, the soluble and uncleaved ectodomain of (gp160)3, retains many antigenic properties of the intact Env, consistent with a conformation close to that of Env spikes on a virion, whereas its monomeric gp120 exposes many nonneutralizing or strain-specific epitopes. Thus, trimer organization and stability are important determinants not only for occluding many epitopes but also for conferring resistance to neutralization by all but a small set of antibodies. Env preparations derived from neutralization-resistant viruses may induce irrelevant antibody responses less frequently than do other Envs and may be excellent templates for developing soluble immunogens.
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Augusto MT, Hollmann A, Troise F, Veiga AS, Pessi A, Santos NC. Lipophilicity is a key factor to increase the antiviral activity of HIV neutralizing antibodies. Colloids Surf B Biointerfaces 2017; 152:311-316. [DOI: 10.1016/j.colsurfb.2017.01.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 10/20/2022]
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Lipid interactions and angle of approach to the HIV-1 viral membrane of broadly neutralizing antibody 10E8: Insights for vaccine and therapeutic design. PLoS Pathog 2017; 13:e1006212. [PMID: 28225819 PMCID: PMC5338832 DOI: 10.1371/journal.ppat.1006212] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 03/06/2017] [Accepted: 02/02/2017] [Indexed: 01/26/2023] Open
Abstract
Among broadly neutralizing antibodies to HIV, 10E8 exhibits greater neutralizing breadth than most. Consequently, this antibody is the focus of prophylactic/therapeutic development. The 10E8 epitope has been identified as the conserved membrane proximal external region (MPER) of gp41 subunit of the envelope (Env) viral glycoprotein and is a major vaccine target. However, the MPER is proximal to the viral membrane and may be laterally inserted into the membrane in the Env prefusion form. Nevertheless, 10E8 has not been reported to have significant lipid-binding reactivity. Here we report x-ray structures of lipid complexes with 10E8 and a scaffolded MPER construct and mutagenesis studies that provide evidence that the 10E8 epitope is composed of both MPER and lipid. 10E8 engages lipids through a specific lipid head group interaction site and a basic and polar surface on the light chain. In the model that we constructed, the MPER would then be essentially perpendicular to the virion membrane during 10E8 neutralization of HIV-1. As the viral membrane likely also plays a role in selecting for the germline antibody as well as size and residue composition of MPER antibody complementarity determining regions, the identification of lipid interaction sites and the MPER orientation with regard to the viral membrane surface during 10E8 engagement can be of great utility for immunogen and therapeutic design. The trimeric Env glycoprotein located on HIV surface is the target of broadly neutralizing antibodies and is the focus of vaccine and therapeutic approaches to prevent HIV infection. Structural studies with HIV Env trimers have shed light on the complete epitopes of several broadly neutralizing antibodies. However, structural determination of the complete epitopes of the highly cross-reactive MPER antibodies has been technically difficult due to the viral membrane component and that these epitopes are probably only exposed transiently after Env engages CD4. In this study, we structurally characterize the interaction of the broadest and most potent MPER-targeting antibody, 10E8, with viral membrane lipids and scaffolded MPER and propose how 10E8 approaches the MPER-viral membrane epitope during neutralization. Our results indicate that 10E8 interacts with the viral membrane via its light chain and engages MPER in an upright orientation with respect to the HIV-1 membrane. These findings are of interest for design of HIV-1 vaccines and therapeutics.
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Williams LD, Ofek G, Schätzle S, McDaniel JR, Lu X, Nicely NI, Wu L, Lougheed CS, Bradley T, Louder MK, McKee K, Bailer RT, O'Dell S, Georgiev IS, Seaman MS, Parks RJ, Marshall DJ, Anasti K, Yang G, Nie X, Tumba NL, Wiehe K, Wagh K, Korber B, Kepler TB, Munir Alam S, Morris L, Kamanga G, Cohen MS, Bonsignori M, Xia SM, Montefiori DC, Kelsoe G, Gao F, Mascola JR, Moody MA, Saunders KO, Liao HX, Tomaras GD, Georgiou G, Haynes BF. Potent and broad HIV-neutralizing antibodies in memory B cells and plasma. Sci Immunol 2017; 2:2/7/eaal2200. [PMID: 28783671 DOI: 10.1126/sciimmunol.aal2200] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/20/2016] [Indexed: 12/13/2022]
Abstract
Induction of broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development. Antibody 10E8, reactive with the distal portion of the membrane-proximal external region (MPER) of HIV-1 gp41, is broadly neutralizing. However, the ontogeny of distal MPER antibodies and the relationship of memory B cell to plasma bnAbs are poorly understood. HIV-1-specific memory B cell flow sorting and proteomic identification of anti-MPER plasma antibodies from an HIV-1-infected individual were used to isolate broadly neutralizing distal MPER bnAbs of the same B cell clonal lineage. Structural analysis demonstrated that antibodies from memory B cells and plasma recognized the envelope gp41 bnAb epitope in a distinct orientation compared with other distal MPER bnAbs. The unmutated common ancestor of this distal MPER bnAb was autoreactive, suggesting lineage immune tolerance control. Construction of chimeric antibodies of memory B cell and plasma antibodies yielded a bnAb that potently neutralized most HIV-1 strains.
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Affiliation(s)
- LaTonya D Williams
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Gilad Ofek
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Sebastian Schätzle
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Jonathan R McDaniel
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Xiaozhi Lu
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Nathan I Nicely
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Liming Wu
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Caleb S Lougheed
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Todd Bradley
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mark K Louder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
| | - Krisha McKee
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
| | - Robert T Bailer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
| | - Sijy O'Dell
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
| | - Ivelin S Georgiev
- Vanderbilt Vaccine Center and Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Michael S Seaman
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Robert J Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Dawn J Marshall
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kara Anasti
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Guang Yang
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Xiaoyan Nie
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Nancy L Tumba
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg 2131, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Congella 4013, South Africa
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kshitij Wagh
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Bette Korber
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Thomas B Kepler
- Departments of Microbiology and Mathematics & Statistics, Boston University School of Medicine, Boston, MA 02118, USA
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Pathology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Lynn Morris
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg 2131, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Congella 4013, South Africa
| | - Gift Kamanga
- University of North Carolina Project-Malawi, Kamuzu Central Hospital, Lilongwe, Malawi
| | - Myron S Cohen
- Departments of Medicine, Epidemiology, and Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Mattia Bonsignori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Shi-Mao Xia
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - David C Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Garnett Kelsoe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Feng Gao
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hua-Xin Liao
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Surgery, Duke University School of Medicine, Durham, NC 27710, USA.,Department of 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
| | - George Georgiou
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA. .,Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA. .,Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Immunology, Duke University School of Medicine, Durham, NC 27710, USA
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55
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Proteoliposomal formulations of an HIV-1 gp41-based miniprotein elicit a lipid-dependent immunodominant response overlapping the 2F5 binding motif. Sci Rep 2017; 7:40800. [PMID: 28084464 PMCID: PMC5234007 DOI: 10.1038/srep40800] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/12/2016] [Indexed: 12/15/2022] Open
Abstract
The HIV-1 gp41 Membrane Proximal External Region (MPER) is recognized by broadly neutralizing antibodies and represents a promising vaccine target. However, MPER immunogenicity and antibody activity are influenced by membrane lipids. To evaluate lipid modulation of MPER immunogenicity, we generated a 1-Palmitoyl-2-oleoylphosphatidylcholine (POPC)-based proteoliposome collection containing combinations of phosphatidylserine (PS), GM3 ganglioside, cholesterol (CHOL), sphingomyelin (SM) and the TLR4 agonist monophosphoryl lipid A (MPLA). A recombinant gp41-derived miniprotein (gp41-MinTT) exposing the MPER and a tetanus toxoid (TT) peptide that favors MHC-II presentation, was successfully incorporated into lipid mixtures (>85%). Immunization of mice with soluble gp41-MinTT exclusively induced responses against the TT peptide, while POPC proteoliposomes generated potent anti-gp41 IgG responses using lower protein doses. The combined addition of PS and GM3 or CHOL/SM to POPC liposomes greatly increased gp41 immunogenicity, which was further enhanced by the addition of MPLA. Responses generated by all proteoliposomes targeted the N-terminal moiety of MPER overlapping the 2F5 neutralizing epitope. Our data show that lipids impact both, the epitope targeted and the magnitude of the response to membrane-dependent antigens, helping to improve MPER-based lipid carriers. Moreover, the identification of immunodominant epitopes allows for the redesign of immunogens targeting MPER neutralizing determinants.
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56
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Wibmer CK, Gorman J, Ozorowski G, Bhiman JN, Sheward DJ, Elliott DH, Rouelle J, Smira A, Joyce MG, Ndabambi N, Druz A, Asokan M, Burton DR, Connors M, Abdool Karim SS, Mascola JR, Robinson JE, Ward AB, Williamson C, Kwong PD, Morris L, Moore PL. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape. PLoS Pathog 2017; 13:e1006074. [PMID: 28076415 PMCID: PMC5226681 DOI: 10.1371/journal.ppat.1006074] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/17/2016] [Indexed: 12/15/2022] Open
Abstract
A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not be completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing antibodies and identifies a set of mutations in the gp120 C terminus that exposes the membrane-proximal external region of gp41, with potential utility in HIV vaccine design.
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Affiliation(s)
- Constantinos Kurt Wibmer
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, CHAVI-ID, IAVI Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery (CAVD), The Scripps Research Institute, La Jolla, California, United States of America
| | - Jinal N. Bhiman
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Daniel J. Sheward
- Institute of Infectious Disease and Molecular Medicine (IDM) and Division of Medical Virology, University of Cape Town and NHLS, Cape Town, South Africa
| | - Debra H. Elliott
- Department of Pediatrics, Tulane University Medical Center, New Orleans, Louisiana, United States of America
| | - Julie Rouelle
- Department of Pediatrics, Tulane University Medical Center, New Orleans, Louisiana, United States of America
| | - Ashley Smira
- Department of Pediatrics, Tulane University Medical Center, New Orleans, Louisiana, United States of America
| | - M. Gordon Joyce
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nonkululeko Ndabambi
- Institute of Infectious Disease and Molecular Medicine (IDM) and Division of Medical Virology, University of Cape Town and NHLS, Cape Town, South Africa
| | - Aliaksandr Druz
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Mangai Asokan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Dennis R. Burton
- Department of Immunology and Microbial Science, CHAVI-ID and IAVI Neutralizing Antibody Centre, The Scripps Research Institute, La Jolla, California, United States of America
- Ragon Institute of Massachusetts General Hospital, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Mark Connors
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Salim S. Abdool Karim
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
- Department of Epidemiology, Columbia University, New York, New York, United States of America
| | - John R. Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - James E. Robinson
- Department of Pediatrics, Tulane University Medical Center, New Orleans, Louisiana, United States of America
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, CHAVI-ID, IAVI Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery (CAVD), The Scripps Research Institute, La Jolla, California, United States of America
| | - Carolyn Williamson
- Institute of Infectious Disease and Molecular Medicine (IDM) and Division of Medical Virology, University of Cape Town and NHLS, Cape Town, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Peter D. Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lynn Morris
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Penny L. Moore
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
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Yi HA, Fochtman BC, Rizzo RC, Jacobs A. Inhibition of HIV Entry by Targeting the Envelope Transmembrane Subunit gp41. Curr HIV Res 2016; 14:283-94. [PMID: 26957202 DOI: 10.2174/1570162x14999160224103908] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 09/23/2015] [Accepted: 09/30/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND The transmembrane subunit of the HIV envelope protein, gp41 is a vulnerable target to inhibit HIV entry. There is one fusion inhibitor T20 (brand name: Fuzeon, generic name: enfuvirtide) available by prescription. However, it has several drawbacks such as a high level of development of drug resistance, a short-half life in vivo, rapid renal clearance, low oral bioavailability, and it is only used as a salvage therapy. Therefore, investigators have been studying a variety of different modalities to attempt to overcome these limitations. METHODS Comprehensive literature searches were performed on HIV gp41, inhibition mechanisms, and inhibitors. The latest structural information was collected, and multiple inhibition strategies targeting gp41 were reviewed. RESULTS Many of the recent advances in inhibitors were peptide-based. Several creative modification strategies have also been performed to improve inhibitory efficacy of peptides and to overcome the drawbacks of T20 treatment. Small compounds have also been an area of intense research. There is a wide variety in development from those identified by virtual screens targeting specific regions of the protein to natural products. Finally, broadly neutralizing antibodies have also been important area of research. The inaccessible nature of the target regions for antibodies is a challenge, however, extensive efforts to develop better neutralizing antibodies are ongoing. CONCLUSION The fusogenic protein, gp41 has been extensively studied as a promising target to inhibit membrane fusion between the virus and target cells. At the same time, it is a challenging target because the vulnerable conformations of the protein are exposed only transiently. However, advances in biochemical, biophysical, structural, and immunological studies are coming together to move the field closer to an understanding of gp41 structure and function that will lead to the development of novel drugs and vaccines.
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Affiliation(s)
| | | | | | - Amy Jacobs
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA.
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58
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Chen B, Chou JJ. Structure of the transmembrane domain of HIV-1 envelope glycoprotein. FEBS J 2016; 284:1171-1177. [PMID: 27868386 DOI: 10.1111/febs.13954] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/02/2016] [Indexed: 12/15/2022]
Abstract
HIV-1 envelope spike (Env) is a heavily glycosylated, type I membrane protein that mediates fusion of viral and cell membranes to initiate infection. It is also a primary target of neutralizing antibodies and thus an important candidate for vaccine development. We have recently reported a nuclear magnetic resonance structure of the transmembrane (TM) domain of HIV-1 Env reconstituted in a membrane-like environment. Taking HIV-1 as an example, we discuss here how a TM domain can anchor, stabilize, and modulate a viral envelope spike and how its high-resolution structure can contribute to understanding viral membrane fusion and to immunogen design.
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Affiliation(s)
- Bing Chen
- Division of Molecular Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - James J Chou
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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Learning the Relationship between the Primary Structure of HIV Envelope Glycoproteins and Neutralization Activity of Particular Antibodies by Using Artificial Neural Networks. Int J Mol Sci 2016; 17:ijms17101710. [PMID: 27727189 PMCID: PMC5085742 DOI: 10.3390/ijms17101710] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 09/26/2016] [Accepted: 10/03/2016] [Indexed: 12/02/2022] Open
Abstract
The dependency between the primary structure of HIV envelope glycoproteins (ENV) and the neutralization data for given antibodies is very complicated and depends on a large number of factors, such as the binding affinity of a given antibody for a given ENV protein, and the intrinsic infection kinetics of the viral strain. This paper presents a first approach to learning these dependencies using an artificial feedforward neural network which is trained to learn from experimental data. The results presented here demonstrate that the trained neural network is able to generalize on new viral strains and to predict reliable values of neutralizing activities of given antibodies against HIV-1.
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60
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Comparison of Antibody-Dependent Cell-Mediated Cytotoxicity and Virus Neutralization by HIV-1 Env-Specific Monoclonal Antibodies. J Virol 2016; 90:6127-6139. [PMID: 27122574 DOI: 10.1128/jvi.00347-16] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/16/2016] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED Although antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FL or SHIVAD8-EO ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection. IMPORTANCE This study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.
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61
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Engineering Recombinant Reoviruses To Display gp41 Membrane-Proximal External-Region Epitopes from HIV-1. mSphere 2016; 1:mSphere00086-16. [PMID: 27303748 PMCID: PMC4888892 DOI: 10.1128/msphere.00086-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/25/2016] [Indexed: 12/30/2022] Open
Abstract
Vaccines to protect against HIV-1, the causative agent of AIDS, are not approved for use. Antibodies that neutralize genetically diverse strains of HIV-1 bind to discrete regions of the envelope glycoproteins, including the gp41 MPER. We engineered recombinant reoviruses that displayed MPER epitopes in attachment protein σ1 (REO-MPER vectors). The REO-MPER vectors replicated with wild-type efficiency, were genetically stable, and retained native antigenicity. However, we did not detect HIV-1-specific immune responses following inoculation of the REO-MPER vectors into small animals. This work provides proof of principle for engineering reovirus to express antigenic epitopes and illustrates the difficulty in eliciting MPER-specific immune responses. The gp41 membrane-proximal external region (MPER) is a target for broadly neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1). However, replication-defective virus vaccines currently under evaluation in clinical trials do not efficiently elicit MPER-specific antibodies. Structural modeling suggests that the MPER forms an α-helical coiled coil that is required for function and immunogenicity. To maintain the native MPER conformation, we used reverse genetics to engineer replication-competent reovirus vectors that displayed MPER sequences in the α-helical coiled-coil tail domain of viral attachment protein σ1. Sequences in reovirus strain type 1 Lang (T1L) σ1 were exchanged with sequences encoding HIV-1 strain Ba-L MPER epitope 2F5 or the entire MPER. Individual 2F5 or MPER substitutions were introduced at virion-proximal or virion-distal sites in the σ1 tail. Recombinant reoviruses containing heterologous HIV-1 sequences were viable and produced progeny yields comparable to those with wild-type virus. HIV-1 sequences were retained following 10 serial passages in cell culture, indicating that the substitutions were genetically stable. Recombinant viruses engineered to display the 2F5 epitope or full-length MPER in σ1 were recognized by purified 2F5 antibody. Inoculation of mice with 2F5-containing vectors or rabbits with 2F5- or MPER-containing vectors elicited anti-reovirus antibodies, but HIV-1-specific antibodies were not detected. Together, these findings indicate that heterologous sequences that form α-helices can functionally replace native sequences in the α-helical tail domain of reovirus attachment protein σ1. However, although these vectors retain native antigenicity, they were not immunogenic, illustrating the difficulty of experimentally inducing immune responses to this essential region of HIV-1. IMPORTANCE Vaccines to protect against HIV-1, the causative agent of AIDS, are not approved for use. Antibodies that neutralize genetically diverse strains of HIV-1 bind to discrete regions of the envelope glycoproteins, including the gp41 MPER. We engineered recombinant reoviruses that displayed MPER epitopes in attachment protein σ1 (REO-MPER vectors). The REO-MPER vectors replicated with wild-type efficiency, were genetically stable, and retained native antigenicity. However, we did not detect HIV-1-specific immune responses following inoculation of the REO-MPER vectors into small animals. This work provides proof of principle for engineering reovirus to express antigenic epitopes and illustrates the difficulty in eliciting MPER-specific immune responses.
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Dai L, Song J, Lu X, Deng YQ, Musyoki AM, Cheng H, Zhang Y, Yuan Y, Song H, Haywood J, Xiao H, Yan J, Shi Y, Qin CF, Qi J, Gao GF. Structures of the Zika Virus Envelope Protein and Its Complex with a Flavivirus Broadly Protective Antibody. Cell Host Microbe 2016; 19:696-704. [PMID: 27158114 DOI: 10.1016/j.chom.2016.04.013] [Citation(s) in RCA: 366] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 04/18/2016] [Accepted: 04/22/2016] [Indexed: 10/21/2022]
Abstract
Zika virus (ZIKV), a mosquito-borne flavivirus, is a current global public health concern. The flavivirus envelope (E) glycoprotein is responsible for virus entry and represents a major target of neutralizing antibodies for other flaviviruses. Here, we report the structures of ZIKV E protein at 2.0 Å and in complex with a flavivirus broadly neutralizing murine antibody 2A10G6 at 3.0 Å. ZIKV-E resembles all the known flavivirus E structures but contains a unique, positively charged patch adjacent to the fusion loop region of the juxtaposed monomer, which may influence host attachment. The ZIKV-E-2A10G6 complex structure reveals antibody recognition of a highly conserved fusion loop. 2A10G6 binds to ZIKV-E with high affinity in vitro and neutralizes currently circulating ZIKV strains in vitro and in mice. The E protein fusion loop epitope represents a potential candidate for therapeutic antibodies against ZIKV.
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Affiliation(s)
- Lianpan Dai
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Jian Song
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xishan Lu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yong-Qiang Deng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100101, China
| | - Abednego Moki Musyoki
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huijun Cheng
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanfang Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yuan Yuan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Song
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Joel Haywood
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haixia Xiao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jinghua Yan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China; CAS Key Laboratory of Microbial Physiology and Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Shi
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China
| | - Cheng-Feng Qin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100101, China.
| | - Jianxun Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China.
| | - George F Gao
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100071, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China; Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen 518112, China; Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China; National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China.
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63
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Lee JH, Ozorowski G, Ward AB. Cryo-EM structure of a native, fully glycosylated, cleaved HIV-1 envelope trimer. Science 2016; 351:1043-8. [PMID: 26941313 DOI: 10.1126/science.aad2450] [Citation(s) in RCA: 339] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The envelope glycoprotein trimer (Env) on the surface of HIV-1 recognizes CD4(+) T cells and mediates viral entry. During this process, Env undergoes substantial conformational rearrangements, making it difficult to study in its native state. Soluble stabilized trimers have provided valuable insights into the Env structure, but they lack the hydrophobic membrane proximal external region (MPER, an important target of broadly neutralizing antibodies), the transmembrane domain, and the cytoplasmic tail. Here we present (i) a cryogenic electron microscopy (cryo-EM) structure of a clade B virus Env, which lacks only the cytoplasmic tail and is stabilized by the broadly neutralizing antibody PGT151, at a resolution of 4.2 angstroms and (ii) a reconstruction of this form of Env in complex with PGT151 and MPER-targeting antibody 10E8 at a resolution of 8.8 angstroms. These structures provide new insights into the wild-type Env structure.
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Affiliation(s)
- Jeong Hyun Lee
- Department of Integrative Structural and Computational Biology, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center, and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
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64
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Kessans SA, Linhart MD, Meador LR, Kilbourne J, Hogue BG, Fromme P, Matoba N, Mor TS. Immunological Characterization of Plant-Based HIV-1 Gag/Dgp41 Virus-Like Particles. PLoS One 2016; 11:e0151842. [PMID: 26986483 PMCID: PMC4795674 DOI: 10.1371/journal.pone.0151842] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 03/04/2016] [Indexed: 02/08/2023] Open
Abstract
It is widely anticipated that a prophylactic vaccine may be needed to control the HIV/AIDS epidemic worldwide. Despite over two decades of research, a vaccine against HIV-1 remains elusive, although a recent clinical trial has shown promising results. Recent studies have focused on highly conserved domains within HIV-1 such as the membrane proximal external region (MPER) of the envelope glycoprotein, gp41. MPER has been shown to play critical roles in mucosal transmission of HIV-1, though this peptide is poorly immunogenic on its own. Here we provide evidence that plant-produced HIV-1 enveloped virus-like particles (VLPs) consisting of Gag and a deconstructed form of gp41 comprising the MPER, transmembrane, and cytoplasmic domains (Dgp41) provides an effective platform to display MPER for use as an HIV vaccine candidate. Prime-boost strategies combining systemic and mucosal priming with systemic boosting using two different vaccine candidates (VLPs and CTB-MPR--a fusion of MPER and the B-subunit of cholera toxin) were investigated in BALB/c mice. Serum antibody responses against both the Gag and gp41 antigens were elicited when systemically primed with VLPs. These responses could be recalled following systemic boosting with VLPs. In addition, mucosal priming with VLPs allowed for a boosting response against Gag and gp41 when boosted with either candidate. Importantly, the VLPs also induced Gag-specific CD4 and CD8 T-cell responses. This report on the immunogenicity of plant-based Gag/Dgp41 VLPs may represent an important milestone on the road towards a broadly efficacious and inexpensive subunit vaccine against HIV-1.
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Affiliation(s)
- Sarah A. Kessans
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Mark D. Linhart
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Lydia R. Meador
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Jacquelyn Kilbourne
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Brenda G. Hogue
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Petra Fromme
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| | - Nobuyuki Matoba
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Tsafrir S. Mor
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
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Reichart TM, Baksh MM, Rhee JK, Fiedler JD, Sligar SG, Finn MG, Zwick MB, Dawson PE. Trimerization of the HIV Transmembrane Domain in Lipid Bilayers Modulates Broadly Neutralizing Antibody Binding. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201508421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Timothy M. Reichart
- Department of Chemistry; The Scripps Research Institute; 10550 North Torrey Pines Road La Jolla CA 92037 USA
| | - Michael M. Baksh
- Department of Chemistry; The Scripps Research Institute; 10550 North Torrey Pines Road La Jolla CA 92037 USA
- School of Chemistry & Biochemistry; Georgia Institute of Technology; 901 Atlantic Drive Atlanta GA 30332 USA
| | - Jin-Kyu Rhee
- Department of Food Science and Engineering; Ewha Womans University; Seoul 03760 Korea
| | - Jason D. Fiedler
- Department of Chemistry; The Scripps Research Institute; 10550 North Torrey Pines Road La Jolla CA 92037 USA
| | - Stephen G. Sligar
- Department of Biochemistry; University of Illinois; Urbana IL 61801 USA
| | - M. G. Finn
- Department of Chemistry; The Scripps Research Institute; 10550 North Torrey Pines Road La Jolla CA 92037 USA
- School of Chemistry & Biochemistry; Georgia Institute of Technology; 901 Atlantic Drive Atlanta GA 30332 USA
| | - Michael B. Zwick
- Department of Immunology and Microbial Science; The Scripps Research Institute; 10550 North Torrey Pines Road La Jolla CA USA
| | - Philip E. Dawson
- Department of Chemistry; The Scripps Research Institute; 10550 North Torrey Pines Road La Jolla CA 92037 USA
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Reichart TM, Baksh MM, Rhee JK, Fiedler JD, Sligar SG, Finn MG, Zwick MB, Dawson PE. Trimerization of the HIV Transmembrane Domain in Lipid Bilayers Modulates Broadly Neutralizing Antibody Binding. Angew Chem Int Ed Engl 2016; 55:2688-92. [PMID: 26799917 PMCID: PMC5405556 DOI: 10.1002/anie.201508421] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/04/2015] [Indexed: 12/18/2022]
Abstract
The membrane-proximal external region (MPER) of HIV gp41 is an established target of antibodies that neutralize a broad range of HIV isolates. To evaluate the role of the transmembrane (TM) domain, synthetic MPER-derived peptides were incorporated into lipid nanoparticles using natural and designed TM domains, and antibody affinity was measured using immobilized and solution-based techniques. Peptides incorporating the native HIV TM domain exhibit significantly stronger interactions with neutralizing antibodies than peptides with a monomeric TM domain. Furthermore, a peptide with a trimeric, three-helix bundle TM domain recapitulates the binding profile of the native sequence. These studies suggest that neutralizing antibodies can bind the MPER when the TM domain is a three-helix bundle and this presentation could influence the binding of neutralizing antibodies to the virus. Lipid-bilayer presentation of viral antigens in Nanodiscs is a new platform for evaluating neutralizing antibodies.
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Affiliation(s)
- Timothy M Reichart
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Michael M Baksh
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA, 30332, USA
| | - Jin-Kyu Rhee
- Department of Food Science and Engineering, Ewha Womans University, Seoul, 03760, Korea
| | - Jason D Fiedler
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Stephen G Sligar
- Department of Biochemistry, University of Illinois, Urbana, IL, 61801, USA
| | - M G Finn
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA, 30332, USA
| | - Michael B Zwick
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA
| | - Philip E Dawson
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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67
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Jin S, Ji Y, Wang Q, Wang H, Shi X, Han X, Zhou T, Shang H, Zhang L. Spatiotemporal hierarchy in antibody recognition against transmitted HIV-1 envelope glycoprotein during natural infection. Retrovirology 2016; 13:12. [PMID: 26883323 PMCID: PMC4756523 DOI: 10.1186/s12977-016-0243-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/04/2016] [Indexed: 12/31/2022] Open
Abstract
Background Majority of HIV-1 infection is established by one transmitted/founder virus and understanding how the neutralizing antibodies develop against this virus is critical for our rational design an HIV-1 vaccine.
Results We report here antibody profiling of sequential plasma samples against transmitted/founder HIV-1 envelope glycoprotein in an epidemiologically linked transmission pair using our previously reported antigen library approach. We have decomposed the antibody recognition into three major subdomains on the envelope and showed their development in vivo followed a spatiotemporal hierarchy: starting with the ectodomain of gp41 at membrane proximal region, then the V3C3V4 and the V1V2 of gp120 at the membrane distal region. While antibodies to these subdomains appeared to undergo avidity maturation, the early anti-gp41 antibodies failed to translate into detectable autologous neutralization. Instead, it was the much delayed anti-V3C3V4 and anti-V1V2 antibodies constituted the major neutralizing activities. Conclusions Our results indicate that the initial antibody response was severely misguided by the transmitted/founder virus and future vaccine design would need to avoid the ectodomain of gp41 and focus on the neutralizing targets in the V3C3V4 and V1V2 subdomains of gp120. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0243-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Su Jin
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, 100084, China.
| | - Yangtao Ji
- Key Laboratory of AIDS Immunology of Ministry of Health, Department of Laboratory Medicine, No. 1 Hospital of China Medical University, Shenyang, 110001, China.
| | - Qian Wang
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, 100084, China.
| | - Hua Wang
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, 100084, China.
| | - Xuanling Shi
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, 100084, China.
| | - Xiaoxu Han
- Key Laboratory of AIDS Immunology of Ministry of Health, Department of Laboratory Medicine, No. 1 Hospital of China Medical University, Shenyang, 110001, China.
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Hong Shang
- Key Laboratory of AIDS Immunology of Ministry of Health, Department of Laboratory Medicine, No. 1 Hospital of China Medical University, Shenyang, 110001, China.
| | - Linqi Zhang
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, 100084, China.
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68
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Zhao C, Ao Z, Yao X. Current Advances in Virus-Like Particles as a Vaccination Approach against HIV Infection. Vaccines (Basel) 2016; 4:vaccines4010002. [PMID: 26805898 PMCID: PMC4810054 DOI: 10.3390/vaccines4010002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/31/2015] [Accepted: 01/18/2016] [Indexed: 12/16/2022] Open
Abstract
HIV-1 virus-like particles (VLPs) are promising vaccine candidates against HIV-1 infection. They are capable of preserving the native conformation of HIV-1 antigens and priming CD4+ and CD8+ T cell responses efficiently via cross presentation by both major histocompatibility complex (MHC) class I and II molecules. Progress has been achieved in the preclinical research of HIV-1 VLPs as prophylactic vaccines that induce broadly neutralizing antibodies and potent T cell responses. Moreover, the progress in HIV-1 dendritic cells (DC)-based immunotherapy provides us with a new vision for HIV-1 vaccine development. In this review, we describe updates from the past 5 years on the development of HIV-1 VLPs as a vaccine candidate and on the combined use of HIV particles with HIV-1 DC-based immunotherapy as efficient prophylactic and therapeutic vaccination strategies.
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Affiliation(s)
- Chongbo Zhao
- Laboratory of Molecular Human Retrovirology, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Zhujun Ao
- Laboratory of Molecular Human Retrovirology, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Xiaojian Yao
- Laboratory of Molecular Human Retrovirology, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
- Department of Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410078, Hunan, China.
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69
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Banerjee S, Shi H, Habte HH, Qin Y, Cho MW. Modulating immunogenic properties of HIV-1 gp41 membrane-proximal external region by destabilizing six-helix bundle structure. Virology 2016; 490:17-26. [PMID: 26803471 DOI: 10.1016/j.virol.2016.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/05/2016] [Accepted: 01/09/2016] [Indexed: 01/31/2023]
Abstract
The C-terminal alpha-helix of gp41 membrane-proximal external region (MPER; (671)NWFDITNWLWYIK(683)) encompassing 4E10/10E8 epitopes is an attractive target for HIV-1 vaccine development. We previously reported that gp41-HR1-54Q, a trimeric protein comprised of the MPER in the context of a stable six-helix bundle (6HB), induced strong immune responses against the helix, but antibodies were directed primarily against the non-neutralizing face of the helix. To better target 4E10/10E8 epitopes, we generated four putative fusion intermediates by introducing double point mutations or deletions in the heptad repeat region 1 (HR1) that destabilize 6HB in varying degrees. One variant, HR1-∆10-54K, elicited antibodies in rabbits that targeted W672, I675 and L679, which are critical for 4E10/10E8 recognition. Overall, the results demonstrated that altering structural parameters of 6HB can influence immunogenic properties of the MPER and antibody targeting. Further exploration of this strategy could allow development of immunogens that could lead to induction of 4E10/10E8-like antibodies.
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Affiliation(s)
- Saikat Banerjee
- Department of Biomedical Sciences, College of Veterinary Medicine; and Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA 50011, United States
| | - Heliang Shi
- Department of Biomedical Sciences, College of Veterinary Medicine; and Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA 50011, United States
| | - Habtom H Habte
- Department of Biomedical Sciences, College of Veterinary Medicine; and Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA 50011, United States
| | - Yali Qin
- Department of Biomedical Sciences, College of Veterinary Medicine; and Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA 50011, United States
| | - Michael W Cho
- Department of Biomedical Sciences, College of Veterinary Medicine; and Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA 50011, United States.
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Irimia A, Sarkar A, Stanfield RL, Wilson IA. Crystallographic Identification of Lipid as an Integral Component of the Epitope of HIV Broadly Neutralizing Antibody 4E10. Immunity 2016; 44:21-31. [PMID: 26777395 DOI: 10.1016/j.immuni.2015.12.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 01/24/2023]
Abstract
Numerous studies of the anti-HIV-1 envelope glycoprotein 41 (gp41) broadly neutralizing antibody 4E10 suggest that 4E10 also interacts with membrane lipids, but the antibody regions contacting lipids and its orientation with respect to the viral membrane are unknown. Vaccine immunogens capable of re-eliciting these membrane proximal external region (MPER)-like antibodies may require a lipid component to be successful. We performed a systematic crystallographic study of lipid binding to 4E10 to identify lipids bound by the antibody and the lipid-interacting regions. We identified phosphatidic acid, phosphatidylglycerol, and glycerol phosphate as specific ligands for 4E10 in the crystal structures. 4E10 used its CDRH1 loop to bind the lipid head groups, while its CDRH3 interacted with the hydrophobic lipid tails. Identification of the lipid binding sites on 4E10 may aid design of immunogens for vaccines that include a lipid component in addition to the MPER on gp41 for generation of broadly neutralizing antibodies.
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Affiliation(s)
- Adriana Irimia
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Anita Sarkar
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA.
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Su B, Peressin M, Ducloy C, Penichon J, Mayr LM, Laumond G, Schmidt S, Decoville T, Moog C. Short Communication: Exploring Antibody Potential as Prophylactic/Therapeutic Strategies for Prevention of Early Mucosal HIV-1 Infection. AIDS Res Hum Retroviruses 2015; 31:1187-91. [PMID: 26252799 DOI: 10.1089/aid.2015.0041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mucosal tissues are the predominant sites for genital HIV-1 transmission. We investigated the mechanisms by which broadly neutralizing antibodies (bNAbs) inhibit HIV-1 replication in a coculture model including primary mucosal dendritic cells (DCs), such as Langerhans cells, interstitial dendritic cells, and CD4(+) T lymphocytes. We show that bNAbs efficiently prevent HIV-1 infection by inhibiting HIV-1 transmission to CD4(+) T lymphocytes. This inhibition of cell-to-cell transmission was observed with equal potency as the inhibition of cell-free infection of primary CD4(+) T lymphocytes. In addition, a decrease in HIV-1 replication in DCs and the induction of DC maturation were detected. This additional inhibition was Fc mediated as it was blocked by the use of specific anti-FcγR monoclonal Abs. The DC maturation by bNAbs during HIV transmission may contribute to mucosal protection. Therefore, multiple antibody-mediated inhibitory functions should be combined for the improvement of future preventive/therapeutic strategies to cure HIV.
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Affiliation(s)
- Bin Su
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Maryse Peressin
- Centre d'investigation clinique/Service de neurologie, INSERM CIC-P1434, Hôpital de Hautepierre, Strasbourg, France
| | - Camille Ducloy
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Julien Penichon
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Luzia M. Mayr
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Géraldine Laumond
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Sylvie Schmidt
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Thomas Decoville
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
- Vaccine Research Institute, Hôpital Henri Mondor, Créteil, France
| | - Christiane Moog
- INSERM UMR S_1109, Centre de Recherche en Immunologie et Hématologie, Faculté de Médecine, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
- Vaccine Research Institute, Hôpital Henri Mondor, Créteil, France
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72
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Ohlin M, Söderberg-Nauclér C. Human antibody technology and the development of antibodies against cytomegalovirus. Mol Immunol 2015; 67:153-70. [DOI: 10.1016/j.molimm.2015.02.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 02/13/2015] [Accepted: 02/15/2015] [Indexed: 02/08/2023]
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73
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Gallerano D, Cabauatan CR, Sibanda EN, Valenta R. HIV-Specific Antibody Responses in HIV-Infected Patients: From a Monoclonal to a Polyclonal View. Int Arch Allergy Immunol 2015; 167:223-41. [PMID: 26414324 DOI: 10.1159/000438484] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
HIV infections represent a major global health threat, affecting more than 35 million individuals worldwide. High infection rates and problems associated with lifelong antiretroviral treatment emphasize the need for the development of prophylactic and therapeutic immune intervention strategies. It is conceivable that insights for the design of new immunogens capable of eliciting protective immune responses may come from the analysis of HIV-specific antibody responses in infected patients. Using sophisticated technologies, several monoclonal neutralizing antibodies were isolated from HIV-infected individuals. However, the majority of polyclonal antibody responses found in infected patients are nonneutralizing. Comprehensive analyses of the molecular targets of HIV-specific antibody responses identified that during natural infection antibodies are mainly misdirected towards gp120 epitopes outside of the CD4-binding site and against regions and proteins that are not exposed on the surface of the virus. We therefore argue that vaccines aiming to induce protective responses should include engineered immunogens, which are capable of focusing the immune response towards protective epitopes.
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Affiliation(s)
- Daniela Gallerano
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
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74
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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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75
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Biophysical Characterization of a Vaccine Candidate against HIV-1: The Transmembrane and Membrane Proximal Domains of HIV-1 gp41 as a Maltose Binding Protein Fusion. PLoS One 2015; 10:e0136507. [PMID: 26295457 PMCID: PMC4546420 DOI: 10.1371/journal.pone.0136507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 08/05/2015] [Indexed: 11/19/2022] Open
Abstract
The membrane proximal region (MPR, residues 649-683) and transmembrane domain (TMD, residues 684-705) of the gp41 subunit of HIV-1's envelope protein are highly conserved and are important in viral mucosal transmission, virus attachment and membrane fusion with target cells. Several structures of the trimeric membrane proximal external region (residues 662-683) of MPR have been reported at the atomic level; however, the atomic structure of the TMD still remains unknown. To elucidate the structure of both MPR and TMD, we expressed the region spanning both domains, MPR-TM (residues 649-705), in Escherichia coli as a fusion protein with maltose binding protein (MBP). MPR-TM was initially fused to the C-terminus of MBP via a 42 aa-long linker containing a TEV protease recognition site (MBP-linker-MPR-TM). Biophysical characterization indicated that the purified MBP-linker-MPR-TM protein was a monodisperse and stable candidate for crystallization. However, crystals of the MBP-linker-MPR-TM protein could not be obtained in extensive crystallization screens. It is possible that the 42 residue-long linker between MBP and MPR-TM was interfering with crystal formation. To test this hypothesis, the 42 residue-long linker was replaced with three alanine residues. The fusion protein, MBP-AAA-MPR-TM, was similarly purified and characterized. Significantly, both the MBP-linker-MPR-TM and MBP-AAA-MPR-TM proteins strongly interacted with broadly neutralizing monoclonal antibodies 2F5 and 4E10. With epitopes accessible to the broadly neutralizing antibodies, these MBP/MPR-TM recombinant proteins may be in immunologically relevant conformations that mimic a pre-hairpin intermediate of gp41.
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76
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Reh L, Magnus C, Schanz M, Weber J, Uhr T, Rusert P, Trkola A. Capacity of Broadly Neutralizing Antibodies to Inhibit HIV-1 Cell-Cell Transmission Is Strain- and Epitope-Dependent. PLoS Pathog 2015; 11:e1004966. [PMID: 26158270 PMCID: PMC4497647 DOI: 10.1371/journal.ppat.1004966] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/21/2015] [Indexed: 12/11/2022] Open
Abstract
An increasing number of broadly neutralizing antibodies (bnAbs) are considered leads for HIV-1 vaccine development and novel therapeutics. Here, we systematically explored the capacity of bnAbs to neutralize HIV-1 prior to and post-CD4 engagement and to block HIV-1 cell-cell transmission. Cell-cell spread is known to promote a highly efficient infection with HIV-1 which can inflict dramatic losses in neutralization potency compared to free virus infection. Selection of bnAbs that are capable of suppressing HIV irrespective of the transmission mode therefore needs to be considered to ascertain their in vivo activity in therapeutic use and vaccines. Employing assay systems that allow for unambiguous discrimination between free virus and cell-cell transmission to T cells, we probed a panel of 16 bnAbs for their activity against 11 viruses from subtypes A, B and C during both transmission modes. Over a wide range of bnAb-virus combinations tested, inhibitory activity against HIV-1 cell-cell transmission was strongly decreased compared to free virus transmission. Activity loss varied considerably between virus strains and was inversely associated with neutralization of free virus spread for V1V2- and V3-directed bnAbs. In rare bnAb-virus combinations, inhibition for both transmission modes was comparable but no bnAb potently blocked cell-cell transmission across all probed virus strains. Mathematical analysis indicated an increased probability of bnAb resistance mutations to arise in cell-cell rather than free virus spread, further highlighting the need to block this pathway. Importantly, the capacity to efficiently neutralize prior to CD4 engagement correlated with the inhibition efficacy against free virus but not cell-cell transmitted virus. Pre-CD4 attachment activity proved strongest amongst CD4bs bnAbs and varied substantially for V3 and V1V2 loop bnAbs in a strain-dependent manner. In summary, bnAb activity against divergent viruses varied depending on the transmission mode and differed depending on the window of action during the entry process, underscoring that powerful combinations of bnAbs are needed for in vivo application. When selecting broadly neutralizing antibodies (bnAbs) for clinical application, potency and breadth against free viruses are vital, but additional features may be needed to ensure in vivo efficacy. Considering that HIV-1 can utilize free virus and cell-cell transmission to infect, the efficacy of neutralizing antibodies in vivo may depend on their ability to block both pathways. While breadth and potency of bnAbs against free viruses have been intensely studied, their precise activity during cell-cell spread remains uncertain. Our analysis of the cell-cell neutralization capacity of a large selection of bnAbs against a spectrum of HIV-1 strains revealed that while bnAbs showed an overall decreased activity during cell-cell transmission, losses varied substantially depending on bnAb and virus strain probed. Although bnAbs occasionally retained activity during cell-cell transmission for individual viruses, this ability was rare and generally not associated with a high potency against free virus spread. Notably, neutralization of free virus but not cell-cell transmission was linked with the activity of bnAbs to inhibit prior to CD4 engagement, highlighting the functional differences of the processes. Since no single bnAb combines the entire range of mechanistic features anticipated to support in vivo efficacy, our study adds further evidence that combinations of bnAbs need to be considered for human application.
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Affiliation(s)
- Lucia Reh
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Carsten Magnus
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Merle Schanz
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Jacqueline Weber
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Therese Uhr
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Peter Rusert
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Alexandra Trkola
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
- * E-mail:
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77
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Zang Y, Du D, Li N, Su W, Liu X, Zhang Y, Nie J, Wang Y, Kong W, Jiang C. Eliciting neutralizing antibodies against the membrane proximal external region of HIV-1 Env by chimeric live attenuated influenza A virus vaccines. Vaccine 2015; 33:3859-64. [PMID: 26126669 DOI: 10.1016/j.vaccine.2015.06.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/14/2015] [Accepted: 06/17/2015] [Indexed: 10/23/2022]
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78
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Chen J, Kovacs JM, Peng H, Rits-Volloch S, Lu J, Park D, Zablowsky E, Seaman MS, Chen B. HIV-1 ENVELOPE. Effect of the cytoplasmic domain on antigenic characteristics of HIV-1 envelope glycoprotein. Science 2015; 349:191-5. [PMID: 26113642 DOI: 10.1126/science.aaa9804] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/08/2015] [Indexed: 12/20/2022]
Abstract
A major goal for HIV-1 vaccine development is the production of an immunogen to mimic native, functional HIV-1 envelope trimeric spikes (Env) on the virion surface. We lack a reliable description of a native, functional trimer, however, because of inherent instability and heterogeneity in most preparations. We describe here two conformationally homogeneous Envs derived from difficult-to-neutralize primary isolates. All their non-neutralizing epitopes are fully concealed and independent of their proteolytic processing. Most broadly neutralizing antibodies (bnAbs) recognize these native trimers. Truncation of their cytoplasmic tail has little effect on membrane fusion, but it diminishes binding to trimer-specific bnAbs while exposing non-neutralizing epitopes. These results yield a more accurate antigenic picture than hitherto possible of a genuinely untriggered and functional HIV-1 Env; they can guide effective vaccine development.
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Affiliation(s)
- Jia Chen
- Division of Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA. Department of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA
| | - James M Kovacs
- Division of Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA. Department of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA
| | - Hanqin Peng
- Division of Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Sophia Rits-Volloch
- Division of Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Jianming Lu
- Codex BioSolutions, Inc., 401 Professional Drive, Gaithersburg, MD 20879, USA
| | - Donghyun Park
- Division of Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Elise Zablowsky
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Bing Chen
- Division of Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA. Department of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA.
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79
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Immunogens Modeling a Fusion-Intermediate Conformation of gp41 Elicit Antibodies to the Membrane Proximal External Region of the HIV Envelope Glycoprotein. PLoS One 2015; 10:e0128562. [PMID: 26087072 PMCID: PMC4472232 DOI: 10.1371/journal.pone.0128562] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 04/28/2015] [Indexed: 12/02/2022] Open
Abstract
The membrane proximal external region (MPER) of the gp41 subunit of the HIV-1 envelope glycoprotein (Env) contains determinants for broadly neutralizing antibodies and has remained an important focus of vaccine design. However, creating an immunogen that elicits broadly neutralizing antibodies to this region has proven difficult in part due to the relative inaccessibility of the MPER in the native conformation of Env. Here, we describe the antigenicity and immunogenicity of a panel of oligomeric gp41 immunogens designed to model a fusion-intermediate conformation of Env in order to enhance MPER exposure in a relevant conformation. The immunogens contain segments of the gp41 N- and C-heptad repeats to mimic a trapped intermediate, followed by the MPER, with variations that include different N-heptad lengths, insertion of extra epitopes, and varying C-termini. These well-characterized immunogens were evaluated in two different immunization protocols involving gp41 and gp140 proteins, gp41 and gp160 DNA primes, and different immunization schedules and adjuvants. We found that the immunogens designed to reduce extension of helical structure into the MPER elicited the highest MPER antibody binding titers, but these antibodies lacked neutralizing activity. The gp41 protein immunogens also elicited higher MPER titers than the gp140 protein immunogen. In prime-boost studies, the best MPER responses were seen in the groups that received DNA priming with gp41 vectors followed by gp41 protein boosts. Finally, although titers to the entire protein immunogen were similar in the two immunization protocols, MPER-specific titers differed, suggesting that the immunization route, schedule, dose, or adjuvant may differentially influence MPER immunogenicity. These findings inform the design of future MPER immunogens and immunization protocols.
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80
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Jiao J, Rebane AA, Ma L, Gao Y, Zhang Y. Kinetically coupled folding of a single HIV-1 glycoprotein 41 complex in viral membrane fusion and inhibition. Proc Natl Acad Sci U S A 2015; 112:E2855-64. [PMID: 26038562 PMCID: PMC4460471 DOI: 10.1073/pnas.1424995112] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
HIV-1 glycoprotein 41 (gp41) mediates viral entry into host cells by coupling its folding energy to membrane fusion. Gp41 folding is blocked by fusion inhibitors, including the commercial drug T20, to treat HIV/AIDS. However, gp41 folding intermediates, energy, and kinetics are poorly understood. Here, we identified the folding intermediates of a single gp41 trimer-of-hairpins and measured their associated energy and kinetics using high-resolution optical tweezers. We found that folding of gp41 hairpins was energetically independent but kinetically coupled: Each hairpin contributed a folding energy of ∼-23 kBT, but folding of one hairpin successively accelerated the folding rate of the next one by ∼20-fold. Membrane-mimicking micelles slowed down gp41 folding and reduced the stability of the six-helix bundle. However, the stability was restored by cooperative folding of the membrane-proximal external region. Surprisingly, T20 strongly inhibited gp41 folding by actively displacing the C-terminal hairpin strand in a force-dependent manner. The inhibition was abolished by a T20-resistant gp41 mutation. The energetics and kinetics of gp41 folding established by us provides a basis to understand viral membrane fusion, infection, and therapeutic intervention.
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Affiliation(s)
- Junyi Jiao
- Department of Cell Biology, Yale University, School of Medicine, New Haven, CT 06511; Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT 06511
| | - Aleksander A Rebane
- Department of Cell Biology, Yale University, School of Medicine, New Haven, CT 06511; Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT 06511; Department of Physics, Yale University, New Haven, CT 06511
| | - Lu Ma
- Department of Cell Biology, Yale University, School of Medicine, New Haven, CT 06511
| | - Ying Gao
- Department of Cell Biology, Yale University, School of Medicine, New Haven, CT 06511; National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201210, China
| | - Yongli Zhang
- Department of Cell Biology, Yale University, School of Medicine, New Haven, CT 06511; Nanobiology Institute, Yale University, West Haven, CT 06477
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81
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Comparable Antigenicity and Immunogenicity of Oligomeric Forms of a Novel, Acute HIV-1 Subtype C gp145 Envelope for Use in Preclinical and Clinical Vaccine Research. J Virol 2015; 89:7478-93. [PMID: 25972551 DOI: 10.1128/jvi.00412-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 04/02/2015] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Eliciting broadly reactive functional antibodies remains a challenge in human immunodeficiency virus type 1 (HIV-1) vaccine development that is complicated by variations in envelope (Env) subtype and structure. The majority of new global HIV-1 infections are subtype C, and novel antigenic properties have been described for subtype C Env proteins. Thus, an HIV-1 subtype C Env protein (CO6980v0c22) from an infected person in the acute phase (Fiebig stage I/II) was developed as a research reagent and candidate immunogen. The gp145 envelope is a novel immunogen with a fully intact membrane-proximal external region (MPER), extended by a polylysine tail. Soluble gp145 was enriched for trimers that yielded the expected "fan blade" motifs when visualized by cryoelectron microscopy. CO6980v0c22 gp145 reacts with the 4E10, PG9, PG16, and VRC01 HIV-1 neutralizing monoclonal antibodies (MAbs), as well as the V1/V2-specific PGT121, 697, 2158, and 2297 MAbs. Different gp145 oligomers were tested for immunogenicity in rabbits, and purified dimers, trimers, and larger multimers elicited similar levels of cross-subtype binding and neutralizing antibodies to tier 1 and some tier 2 viruses. Immunized rabbit sera did not neutralize the highly resistant CO6980v0c22 pseudovirus but did inhibit the homologous infectious molecular clone in a peripheral blood mononuclear cell (PBMC) assay. This Env is currently in good manufacturing practice (GMP) production to be made available for use as a clinical research tool and further evaluation as a candidate vaccine. IMPORTANCE At present, the product pipeline for HIV vaccines is insufficient and is limited by inadequate capacity to produce large quantities of vaccine to standards required for human clinical trials. Such products are required to evaluate critical questions of vaccine formulation, route, dosing, and schedule, as well as to establish vaccine efficacy. The gp145 Env protein presented in this study forms physical trimers, binds to many of the well-characterized broad neutralizing MAbs that target conserved Env epitopes, and induce cross-subtype neutralizing antibodies as measured in both cell line and primary cell assays. This subtype C Env gp145 protein is currently undergoing good manufacturing practice production for use as a reagent for preclinical studies and for human clinical research. This product will serve as a reagent for comparative studies and may represent a next-generation candidate HIV immunogen.
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82
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Harrison SC. Viral membrane fusion. Virology 2015; 479-480:498-507. [PMID: 25866377 DOI: 10.1016/j.virol.2015.03.043] [Citation(s) in RCA: 519] [Impact Index Per Article: 57.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 02/23/2015] [Accepted: 03/10/2015] [Indexed: 11/27/2022]
Abstract
Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a "fusion loop" or "fusion peptide") engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics.
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Affiliation(s)
- Stephen C Harrison
- Boston Children׳s Hospital, Harvard Medical School, and Howard Hughes Medical Institute, 3 Blackfan Circle, Boston, MA 02115, United States.
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83
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Yi HA, Diaz-Rohrer B, Saminathan P, Jacobs A. The membrane proximal external regions of gp41 from HIV-1 strains HXB2 and JRFL have different sensitivities to alanine mutation. Biochemistry 2015; 54:1681-93. [PMID: 25649507 DOI: 10.1021/bi501171r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The transmembrane subunit (gp41) of the HIV envelope protein complex (Env) mediates the viral fusion step of HIV entry. The membrane proximal external region (MPER), one of the functional domains of gp41, has been the focus of a great deal of research because it is a target for neutralizing antibodies. In this study, we examined 23 amino acid residues in the MPER (660-683) in both a CXCR4 coreceptor-utilizing strain (HXB2) and a CCR5-utilizing strain (JRFL) by alanine scanning mutagenesis. Despite the high degree of gp41 sequence conservation, the effects of alanine mutation in the MPER were different between the two strains. Most mutations in HXB2 had fusogenicity and protein expression levels not less than 50% of that of the wild type in the case of cell-cell fusion. However, ∼30% of the mutants in HXB2 showed a severe defect in fusogenicity in viral entry. Mutations in the MPER of strain JRFL had more dramatic effects than that in HXB2 in cell-cell fusion and viral entry. The fact that there are large differences in the effects of mutation between two strains suggests the potential for the interaction of the MPER with nonconserved sequences such as the fusion peptide and/or other NHR domains as well as potential long-range structural effects on the conformational changes that occur with the Env complex during membrane fusion.
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Affiliation(s)
- Hyun Ah Yi
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York , Buffalo, New York 14214, United States
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84
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Grimm SK, Battles MB, Ackerman ME. Directed evolution of a yeast-displayed HIV-1 SOSIP gp140 spike protein toward improved expression and affinity for conformational antibodies. PLoS One 2015; 10:e0117227. [PMID: 25688555 PMCID: PMC4331506 DOI: 10.1371/journal.pone.0117227] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 12/22/2014] [Indexed: 11/19/2022] Open
Abstract
Design of an envelope-based immunogen capable of inducing a broadly neutralizing antibody response is thought to be key to the development of a protective HIV-1 vaccine. However, the broad diversity of viral variants and a limited ability to produce native envelope have hampered such design efforts. Here we describe adaptation of the yeast display system and use of a combinatorial protein engineering approach to permit directed evolution of HIV envelope variants. Because the intrinsic instability and complexity of this trimeric glycoprotein has greatly impeded the development of immunogens that properly represent the structure of native envelope, this platform addresses an essential need for methodologies with the capacity to rapidly engineer HIV spike proteins towards improved homogeneity, stability, and presentation of neutralizing epitopes. We report for the first time the display of a designed SOSIP gp140 on yeast, and the in vitro evolution of derivatives with greatly improved expression and binding to conformation-dependent antibodies. These efforts represent an initial and critical step toward the ability to rapidly engineer HIV-1 envelope immunogens via directed evolution.
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Affiliation(s)
- Sebastian K. Grimm
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States of America
| | - Michael B. Battles
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States of America
| | - Margaret E. Ackerman
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States of America
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85
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Dai Z, Tao Y, Liu N, Brenowitz MD, Girvin ME, Lai JR. Conditional trimerization and lytic activity of HIV-1 gp41 variants containing the membrane-associated segments. Biochemistry 2015; 54:1589-99. [PMID: 25658332 DOI: 10.1021/bi501376f] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fusion of host and viral membranes is a critical step during infection by membrane-bound viruses. The HIV-1 glycoproteins gp120 (surface subunit) and gp41 (fusion subunit) represent the prototypic system for studying this process; in the prevailing model, the gp41 ectodomain forms a trimeric six-helix bundle that constitutes a critical intermediate and provides the energetic driving force for overcoming barriers associated with membrane fusion. However, most structural studies of gp41 variants have been performed either on ectodomain constructs lacking one or more of the membrane-associated segments (the fusion peptide, FP, the membrane-proximal external region, MPER, and the transmembrane domain, TM) or on variants consisting of these isolated segments alone without the ectodomain. Several recent reports have suggested that the HIV-1 ectodomain, as well as larger construct containing the membrane-bound segments, dissociates from a trimer to a monomer in detergent micelles. Here we compare the properties of a series of gp41 variants to delineate the roles of the ectodomain, FP, and MPER and TM, all in membrane-mimicking environments. We find that these proteins are prone to formation of a monomer in detergent micelles. In one case, we observed exclusive monomer formation at pH 4 but conditional trimerization at pH 7 even at low micromolar (∼5 μM) protein concentrations. Liposome release assays demonstrate that these gp41-related proteins have the capacity to induce content leakage but that this activity is also strongly modulated by pH with much higher activity at pH 4. Circular dichroism, nuclear magnetic resonance, and binding assays with antibodies specific to the MPER provide insight into the structural and functional roles of the FP, MPER, and TM and their effect on structure within the larger context of the fusion subunit.
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Affiliation(s)
- Zhou Dai
- Department of Biochemistry, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
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86
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A multivalent clade C HIV-1 Env trimer cocktail elicits a higher magnitude of neutralizing antibodies than any individual component. J Virol 2014; 89:2507-19. [PMID: 25540368 DOI: 10.1128/jvi.03331-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The sequence diversity of human immunodeficiency virus type 1 (HIV-1) presents a formidable challenge to the generation of an HIV-1 vaccine. One strategy to address such sequence diversity and to improve the magnitude of neutralizing antibodies (NAbs) is to utilize multivalent mixtures of HIV-1 envelope (Env) immunogens. Here we report the generation and characterization of three novel, acute clade C HIV-1 Env gp140 trimers (459C, 405C, and 939C), each with unique antigenic properties. Among the single trimers tested, 459C elicited the most potent NAb responses in vaccinated guinea pigs. We evaluated the immunogenicity of various mixtures of clade C Env trimers and found that a quadrivalent cocktail of clade C trimers elicited a greater magnitude of NAbs against a panel of tier 1A and 1B viruses than any single clade C trimer alone, demonstrating that the mixture had an advantage over all individual components of the cocktail. These data suggest that vaccination with a mixture of clade C Env trimers represents a promising strategy to augment vaccine-elicited NAb responses. IMPORTANCE It is currently not known how to generate potent NAbs to the diverse circulating HIV-1 Envs by vaccination. One strategy to address this diversity is to utilize mixtures of different soluble HIV-1 envelope proteins. In this study, we generated and characterized three distinct, novel, acute clade C soluble trimers. We vaccinated guinea pigs with single trimers as well as mixtures of trimers, and we found that a mixture of four trimers elicited a greater magnitude of NAbs than any single trimer within the mixture. The results of this study suggest that further development of Env trimer cocktails is warranted.
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87
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Krebs SJ, McBurney SP, Kovarik DN, Waddell CD, Jaworski JP, Sutton WF, Gomes MM, Trovato M, Waagmeester G, Barnett SJ, DeBerardinis P, Haigwood NL. Multimeric scaffolds displaying the HIV-1 envelope MPER induce MPER-specific antibodies and cross-neutralizing antibodies when co-immunized with gp160 DNA. PLoS One 2014; 9:e113463. [PMID: 25514675 PMCID: PMC4267727 DOI: 10.1371/journal.pone.0113463] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 10/27/2014] [Indexed: 01/11/2023] Open
Abstract
Developing a vaccine that overcomes the diversity of HIV-1 is likely to require a strategy that directs antibody (Ab) responses toward conserved regions of the viral Envelope (Env). However, the generation of neutralizing Abs (NAbs) targeting these regions through vaccination has proven to be difficult. One conserved region of particular interest is the membrane proximal external region (MPER) of Env located within the gp41 ectodomain. In order to direct the immune response to this region, the MPER and gp41 ectodomain were expressed separately as N-terminal fusions to the E2 protein of Geobacillus stearothermophilus. The E2 protein acts as a scaffold by self-assembling into 60-mer particles, displaying up to 60 copies of the fused target on the surface. Rabbits were immunized with E2 particles displaying MPER and/or the gp41 ectodomain in conjunction with DNA encoding full-length gp160. Only vaccines including E2 particles displaying MPER elicited MPER-specific Ab responses. NAbs were elicited after two immunizations that largely targeted the V3 loop. To overcome V3 immunodominance in the DNA component, E2 particles displaying MPER were used in conjunction with gp160 DNA lacking hypervariable regions V2, V3, or combined V1V2V3. All rabbits had HIV binding Ab responses and NAbs following the second vaccination. Using HIV-2/HIV-1 MPER chimeric viruses as targets, NAbs were detected in 12/16 rabbits after three immunizations. Low levels of NAbs specific for Tier 1 and 2 viruses were observed in all groups. This study provides evidence that co-immunizing E2 particles displaying MPER and gp160 DNA can focus Ab responses toward conserved regions of Env.
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Affiliation(s)
- Shelly J. Krebs
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - Sean P. McBurney
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - Dina N. Kovarik
- Viral Vaccines Program, Seattle Biomedical Research Institute, Seattle, WA, United States of America
| | - Chelsea D. Waddell
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - J. Pablo Jaworski
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - William F. Sutton
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - Michelle M. Gomes
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - Maria Trovato
- Institute of Protein Biochemistry, C.N.R., Naples, Italy
| | - Garret Waagmeester
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
| | - Susan J. Barnett
- Novartis Vaccines & Diagnostics, Emeryville, CA, United States of America
| | | | - Nancy L. Haigwood
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, United States of America
- Viral Vaccines Program, Seattle Biomedical Research Institute, Seattle, WA, United States of America
- * E-mail:
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88
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Stable, uncleaved HIV-1 envelope glycoprotein gp140 forms a tightly folded trimer with a native-like structure. Proc Natl Acad Sci U S A 2014; 111:18542-7. [PMID: 25512514 DOI: 10.1073/pnas.1422269112] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The HIV-1 envelope spike [trimeric (gp160)3, cleaved to (gp120/gp41)3] is the mediator of viral entry and the principal target of humoral immune response to the virus. Production of a recombinant preparation that represents the functional spike poses a challenge for vaccine development, because the (gp120/gp41)3 complex is prone to dissociation. We have reported previously that stable HIV-1 gp140 trimers, the uncleaved ectodomains of (gp160)3, have nearly all of the antigenic properties expected for native viral spikes. Because of recent claims that uncleaved gp140 proteins may adopt a nonnative structure with three gp120 moieties "dangling" from a trimeric gp41 ectodomain in its postfusion conformation, we have inserted a long, flexible linker between gp120 and gp41 in our stable gp140 trimers to assess their stability and to analyze their conformation in solution. The modified trimer has biochemical and antigenic properties virtually identical to those of its unmodified counterpart. Both forms bind a single CD4 per trimer, suggesting that the trimeric conformation occludes two of the three CD4 sites even when a flexible linker has relieved the covalent constraint between gp120 and gp41. In contrast, an artificial trimer containing three gp120s flexibly tethered to a trimerization tag binds three CD4s and has antigenicity nearly identical to that of monomeric gp120. Moreover, the gp41 part of both modified and unmodified gp140 trimers has a structure very different from that of postfusion gp41. These results show that uncleaved gp140 trimers from suitable isolates have compact, native-like structures and support their use as candidate vaccine immunogens.
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89
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Miglietta R, Pastori C, Venuti A, Ochsenbauer C, Lopalco L. Synergy in monoclonal antibody neutralization of HIV-1 pseudoviruses and infectious molecular clones. J Transl Med 2014; 12:346. [PMID: 25496375 PMCID: PMC4274758 DOI: 10.1186/s12967-014-0346-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 11/26/2014] [Indexed: 12/26/2022] Open
Abstract
Background Early events in HIV infection are still poorly understood; virus derived from acute infections, the transmitted/founders IMCs, could provide more reliable information as they represent strains that established HIV infection in vivo, and therefore are investigated to elucidate potentially shared biological features. Methods This study examined synergy in neutralization by six monoclonal antibodies targeting different domains in gp120 and gp41 and assayed in pairwise combination against 11 HIV-1 clade B strains, either Env pseudoviruses (PV, n = 5) or transmitted/founder infectious molecular clones (T/F IMCs, n = 6). Three of the early-infection env tested as PV were juxtaposed with T/F viruses derived from the same three patients, respectively. Results All antibodies reaching IC50 were assayed pairwise (n = 50). T/F IMCs showed overall lower sensitivity to neutralization by single antibodies than PV, including within the three patient-matched pairs. Remarkably, combination index (CI) calculated using the Chow and Talalay method indicated synergy (CI < 0.9) in 42 data sets, and occurred in T/F IMC at similar proportions (15 of 17 antibody-T/F IMC combinations tested) as in pseudoviruses (27 of 33). CI values indicative of additivity and low-level antagonism were seen in 5 and 3 cases, respectively. Most pairs showed comparable synergic neutralizing effects on both virus groups, with the 4E10 + PG16 pair achieving the best synergic effects. Variability in neutralization was mostly observed on pseudovirus isolates, suggesting that factors other than virus isolation technology, such as env conformation, epitope accessibility and antibody concentration, are likely to affect polyclonal neutralization. Conclusions The findings from this study suggest that inhibitory activity of bNAbs can be further augmented through appropriate combination, even against viruses representing circulating strains, which are likely to exhibit a less sensitive Tier 2 neutralization phenotype. This notion has important implications for the design and development of anti-Env bNAb-inducing vaccines and polyclonal sera for passive immunization. Electronic supplementary material The online version of this article (doi:10.1186/s12967-014-0346-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Riccardo Miglietta
- Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy. .,Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Claudia Pastori
- Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy.
| | - Assunta Venuti
- Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy.
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA. .,CFAR, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Lucia Lopalco
- Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy.
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90
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Bird GH, Irimia A, Ofek G, Kwong PD, Wilson IA, Walensky LD. Stapled HIV-1 peptides recapitulate antigenic structures and engage broadly neutralizing antibodies. Nat Struct Mol Biol 2014; 21:1058-67. [PMID: 25420104 PMCID: PMC4304871 DOI: 10.1038/nsmb.2922] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 10/23/2014] [Indexed: 01/28/2023]
Abstract
Hydrocarbon stapling can restore bioactive α-helical structure to natural peptides, yielding research tools and prototype therapeutics to dissect and target protein interactions. Here we explore the capacity of peptide stapling to generate high-fidelity, protease-resistant mimics of antigenic structures for vaccine development. HIV-1 has been refractory to vaccine technologies thus far, although select human antibodies can broadly neutralize HIV-1 by targeting sequences of the gp41 juxtamembrane fusion apparatus. To develop candidate HIV-1 immunogens, we generated and characterized stabilized α-helices of the membrane-proximal external region (SAH-MPER) of gp41. SAH-MPER peptides were remarkably protease resistant and bound to the broadly neutralizing 4E10 and 10E8 antibodies with high affinity, recapitulating the structure of the MPER epitope when differentially engaged by the two anti-HIV Fabs. Thus, stapled peptides may provide a new opportunity to develop chemically stabilized antigens for vaccination.
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Affiliation(s)
- Gregory H. Bird
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Adriana Irimia
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
- Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, USA
| | - Gilad Ofek
- Vaccine Research Center, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter D. Kwong
- Vaccine Research Center, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
- Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, USA
| | - Loren D. Walensky
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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91
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Banerjee K, Weliky DP. Folded monomers and hexamers of the ectodomain of the HIV gp41 membrane fusion protein: potential roles in fusion and synergy between the fusion peptide, hairpin, and membrane-proximal external region. Biochemistry 2014; 53:7184-98. [PMID: 25372604 PMCID: PMC4245979 DOI: 10.1021/bi501159w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
HIV
is an enveloped virus and fusion between the HIV and host cell
membranes is catalyzed by the ectodomain of the HIV gp41 membrane
protein. Both the N-terminal fusion peptide (FP)
and C-terminal membrane-proximal external region
(MPER) are critical for fusion and are postulated to bind to the host
cell and HIV membranes, respectively. Prior to fusion, the gp41 on
the virion is a trimer in noncovalent complex with larger gp120 subunits.
The gp120 bind host cell receptors and move away or dissociate from
gp41 which subsequently catalyzes fusion. In the present work, large
gp41 ectodomain constructs were produced and biophysically and structurally
characterized. One significant finding is observation of synergy between
the FP, hairpin, and MPER in vesicle fusion. The ectodomain-induced
fusion can be very efficient with only ∼15 gp41 per vesicle,
which is comparable to the number of gp41 on a virion. Conditions
are found with predominant monomer or hexamer but not trimer and these
may be oligomeric states during fusion. Monomer gp41 ectodomain is
hyperthermostable and has helical hairpin structure. A new HIV fusion
model is presented where (1) hemifusion is catalyzed by folding of
gp41 ectodomain monomers into hairpins and (2) subsequent fusion steps
are catalyzed by assembly into a hexamer with FPs in an antiparallel
β sheet. There is also significant interest in the gp41 MPER
because it is the epitope of several broadly neutralizing antibodies.
Two of these antibodies bind our gp41 ectodomain constructs and support
investigation of the gp41 ectodomain as an immunogen in HIV vaccine
development.
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Affiliation(s)
- Koyeli Banerjee
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
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92
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Antibody B cell responses in HIV-1 infection. Trends Immunol 2014; 35:549-61. [DOI: 10.1016/j.it.2014.08.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 08/22/2014] [Accepted: 08/25/2014] [Indexed: 01/07/2023]
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93
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Lai RPJ, Hock M, Radzimanowski J, Tonks P, Hulsik DL, Effantin G, Seilly DJ, Dreja H, Kliche A, Wagner R, Barnett SW, Tumba N, Morris L, LaBranche CC, Montefiori DC, Seaman MS, Heeney JL, Weissenhorn W. A fusion intermediate gp41 immunogen elicits neutralizing antibodies to HIV-1. J Biol Chem 2014; 289:29912-26. [PMID: 25160627 PMCID: PMC4208001 DOI: 10.1074/jbc.m114.569566] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 08/01/2014] [Indexed: 11/06/2022] Open
Abstract
The membrane-proximal external region (MPER) of the human immunodeficiency virus, type 1 (HIV-1) envelope glycoprotein subunit gp41 is targeted by potent broadly neutralizing antibodies 2F5, 4E10, and 10E8. These antibodies recognize linear epitopes and have been suggested to target the fusion intermediate conformation of gp41 that bridges viral and cellular membranes. Anti-MPER antibodies exert different degrees of membrane interaction, which is considered to be the limiting factor for the generation of such antibodies by immunization. Here we characterize a fusion intermediate conformation of gp41 (gp41(int)-Cys) and show that it folds into an elongated ∼ 12-nm-long extended structure based on small angle x-ray scattering data. Gp41(int)-Cys was covalently linked to liposomes via its C-terminal cysteine and used as immunogen. The gp41(int)-Cys proteoliposomes were administered alone or in prime-boost regimen with trimeric envelope gp140(CA018) in guinea pigs and elicited high anti-gp41 IgG titers. The sera interacted with a peptide spanning the MPER region, demonstrated competition with broadly neutralizing antibodies 2F5 and 4E10, and exerted modest lipid binding, indicating the presence of MPER-specific antibodies. Although the neutralization potency generated solely by gp140(CA018) was higher than that induced by gp41(int)-Cys, the majority of animals immunized with gp41(int)-Cys proteoliposomes induced modest breadth and potency in neutralizing tier 1 pseudoviruses and replication-competent simian/human immunodeficiency viruses in the TZM-bl assay as well as responses against tier 2 HIV-1 in the A3R5 neutralization assay. Our data thus demonstrate that liposomal gp41 MPER formulation can induce neutralization activity, and the strategy serves to improve breadth and potency of such antibodies by improved vaccination protocols.
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Affiliation(s)
- Rachel P J Lai
- From the Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - Miriam Hock
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France, CNRS, UVHCI, F-38000 Grenoble, France
| | - Jens Radzimanowski
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France, CNRS, UVHCI, F-38000 Grenoble, France
| | - Paul Tonks
- From the Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - David Lutje Hulsik
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France, CNRS, UVHCI, F-38000 Grenoble, France
| | - Gregory Effantin
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France, CNRS, UVHCI, F-38000 Grenoble, France
| | - David J Seilly
- From the Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - Hanna Dreja
- From the Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - Alexander Kliche
- Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Ralf Wagner
- Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Susan W Barnett
- Novartis Vaccines and Diagnostics Inc., Cambridge, Massachusetts 02139
| | - Nancy Tumba
- National Institute for Communicable Diseases, Centre for HIV and Sexually Transmitted Infections, 1 Modderfontein Road, Sandringham 2131, South Africa
| | - Lynn Morris
- National Institute for Communicable Diseases, Centre for HIV and Sexually Transmitted Infections, 1 Modderfontein Road, Sandringham 2131, South Africa
| | - Celia C LaBranche
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, and
| | - David C Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, and
| | - Michael S Seaman
- Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115
| | - Jonathan L Heeney
- From the Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom,
| | - Winfried Weissenhorn
- Université Grenoble Alpes, Unit of Virus Host Cell Interactions (UVHCI), F-38000 Grenoble, France, CNRS, UVHCI, F-38000 Grenoble, France,
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94
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Pancera M, Zhou T, Druz A, Georgiev IS, Soto C, Gorman J, Huang J, Acharya P, Chuang GY, Ofek G, Stewart-Jones GBE, Stuckey J, Bailer RT, Joyce MG, Louder MK, Tumba N, Yang Y, Zhang B, Cohen MS, Haynes BF, Mascola JR, Morris L, Munro JB, Blanchard SC, Mothes W, Connors M, Kwong PD. Structure and immune recognition of trimeric pre-fusion HIV-1 Env. Nature 2014; 514:455-61. [PMID: 25296255 PMCID: PMC4348022 DOI: 10.1038/nature13808] [Citation(s) in RCA: 608] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/01/2014] [Indexed: 12/17/2022]
Abstract
The human immunodeficiency virus type 1 (HIV-1) envelope (Env) spike, comprising three gp120 and three gp41 subunits, is a conformational machine that facilitates HIV-1 entry by rearranging from a mature unliganded state, through receptor-bound intermediates, to a post-fusion state. As the sole viral antigen on the HIV-1 virion surface, Env is both the target of neutralizing antibodies and a focus of vaccine efforts. Here we report the structure at 3.5 Å resolution for an HIV-1 Env trimer captured in a mature closed state by antibodies PGT122 and 35O22. This structure reveals the pre-fusion conformation of gp41, indicates rearrangements needed for fusion activation, and defines parameters of immune evasion and immune recognition. Pre-fusion gp41 encircles amino- and carboxy-terminal strands of gp120 with four helices that form a membrane-proximal collar, fastened by insertion of a fusion peptide-proximal methionine into a gp41-tryptophan clasp. Spike rearrangements required for entry involve opening the clasp and expelling the termini. N-linked glycosylation and sequence-variable regions cover the pre-fusion closed spike; we used chronic cohorts to map the prevalence and location of effective HIV-1-neutralizing responses, which were distinguished by their recognition of N-linked glycan and tolerance for epitope-sequence variation.
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Affiliation(s)
- Marie Pancera
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Tongqing Zhou
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Aliaksandr Druz
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ivelin S. Georgiev
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Cinque Soto
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jason Gorman
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jinghe Huang
- HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Priyamvada Acharya
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Gilad Ofek
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Guillaume B. E. Stewart-Jones
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jonathan Stuckey
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Robert T. Bailer
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - M. Gordon Joyce
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Mark K. Louder
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Nancy Tumba
- Center for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service (NHLS), and University of the Witwatersrand, Johannesburg, South Africa, and Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Yongping Yang
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Baoshan Zhang
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Myron S. Cohen
- Departments of Medicine, Epidemiology, Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Barton F. Haynes
- Duke University Human Vaccine Institute, Departments of Medicine, Surgery, Pediatrics and Immunology, Duke University School of Medicine, and the Center for HIV/AIDS Vaccine Immunology-Immunogen Discovery at Duke University, Durham, North Carolina 27710, USA
| | - John R. Mascola
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Lynn Morris
- Center for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service (NHLS), and University of the Witwatersrand, Johannesburg, South Africa, and Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - James B. Munro
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, USA
| | - Scott C. Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10021, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, USA
| | - Mark Connors
- HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Peter D. Kwong
- Vaccine Research Center, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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95
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Kok T, Gaeguta A, Finnie J, Gorry PR, Churchill M, Li P. Designer antigens for elicitation of broadly neutralizing antibodies against HIV. Clin Transl Immunology 2014; 3:e24. [PMID: 25505973 PMCID: PMC4232059 DOI: 10.1038/cti.2014.22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/31/2014] [Accepted: 08/03/2014] [Indexed: 11/09/2022] Open
Abstract
Broadly neutralizing antibodies (bNAbs) are a consistent protective immune correlate in human immunodeficiency virus (HIV) patients as well as in passive immunotherapy studies. The inability to elicit bNAbs is the core reason underlining the repeated failures in traditional HIV vaccine research. Rare monoclonal bNAbs against HIV, however, have been produced. The significance of producing and studying more monoclonal bNAbs against HIV is underlined by its capability of defining critical epitopes for antigen designs aimed at the development of a serum-neutralizing HIV vaccine. In this regard, traditional antigen preparations have failed. There is a need to clearly advocate the concept, and systematic study, of more sophisticated 'designer antigens' (DAGs), which carry epitopes that can lead to the elicitation of bNAbs. Using an extremely efficient cell-to-cell HIV infection model for the preparation of HIV prefusion intermediates, we have investigated a novel and systematic approach to produce (not screen for) potential bNAbs against HIV. We have established the concept and the experimental system for producing formaldehyde-fixed HIV DAGs that carry temperature-arrested prefusion intermediates. These prefusion intermediates are structures on the cell surface after viral attachment and receptor engagement but before fully functional viral entry. Using defined HIV prefusion DAGs, we have produced monoclonal antibodies (mAbs) specific to novel epitopes on HIV prefusion intermediates. These mAbs do not react with the static/native surface HIV or cellular antigens, but react with the DAGs. This is a paradigm shift from the current mainstream approach of screening elite patients' bNAbs.
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Affiliation(s)
- Tuckweng Kok
- School of Molecular and Biomedical Science, University of Adelaide , Adelaide, South Australia, Australia ; SA Pathology , Adelaide, South Australia, Australia
| | - Adriana Gaeguta
- School of Molecular and Biomedical Science, University of Adelaide , Adelaide, South Australia, Australia
| | - John Finnie
- School of Molecular and Biomedical Science, University of Adelaide , Adelaide, South Australia, Australia ; SA Pathology , Adelaide, South Australia, Australia
| | - Paul R Gorry
- Burnet Institute , Melbourne, Victoria, Australia
| | | | - Peng Li
- School of Molecular and Biomedical Science, University of Adelaide , Adelaide, South Australia, Australia
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96
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Gong Z, Kessans SA, Song L, Dörner K, Lee HH, Meador LR, LaBaer J, Hogue BG, Mor TS, Fromme P. Recombinant expression, purification, and biophysical characterization of the transmembrane and membrane proximal domains of HIV-1 gp41. Protein Sci 2014; 23:1607-18. [PMID: 25155369 DOI: 10.1002/pro.2540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 07/22/2014] [Accepted: 08/20/2014] [Indexed: 11/07/2022]
Abstract
The transmembrane subunit (gp41) of the envelope glycoprotein of HIV-1 associates noncovalently with the surface subunit (gp120) and together they play essential roles in viral mucosal transmission and infection of target cells. The membrane proximal region (MPR) of gp41 is highly conserved and contains epitopes of broadly neutralizing antibodies. The transmembrane (TM) domain of gp41 not only anchors the envelope glycoprotein complex in the viral membrane but also dynamically affects the interactions of the MPR with the membrane. While high-resolution X-ray structures of some segments of the MPR were solved in the past, they represent the post-fusion forms. Structural information on the TM domain of gp41 is scant and at low resolution. Here we describe the design, expression and purification of a protein construct that includes MPR and the transmembrane domain of gp41 (MPR-TMTEV-6His), which reacts with the broadly neutralizing antibodies 2F5 and 4E10 and thereby may represent an immunologically relevant conformation mimicking a prehairpin intermediate of gp41. The expression level of MPR-TMTEV-6His was improved by fusion to the C-terminus of Mistic protein, yielding ∼ 1 mg of pure protein per liter. The isolated MPR-TMTEV-6His protein was biophysically characterized and is a monodisperse candidate for crystallization. This work will enable further investigation into the structure of MPR-TMTEV-6His, which will be important for the structure-based design of a mucosal vaccine against HIV-1.
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Affiliation(s)
- Zhen Gong
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, 85287-1604; The Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, 85287
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97
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Go EP, Hua D, Desaire H. Glycosylation and disulfide bond analysis of transiently and stably expressed clade C HIV-1 gp140 trimers in 293T cells identifies disulfide heterogeneity present in both proteins and differences in O-linked glycosylation. J Proteome Res 2014; 13:4012-27. [PMID: 25026075 PMCID: PMC4156237 DOI: 10.1021/pr5003643] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The HIV-1 envelope protein (Env) mediates viral entry into host cells to initiate infection and is the sole target of antibody-based vaccine development. Significant efforts have been made toward the design, engineering, and expression of various soluble forms of HIV Env immunogen, yet a highly effective immunogen remains elusive. One of the key challenges in the development of an effective HIV vaccine is the presence of the complex set of post-translational modifications (PTMs) on Env, namely, glycosylation and disulfide bonds, that affect protein folding, epitope accessibility, and immunogenecity. Although these PTMs vary with expression systems, variations in Env's PTMs due to changes in the expression method are not yet well established. In this study, we compared the disulfide bond network and glycosylation profiles of clade C recombinant HIV-1 Env trimers, C97ZA012 gp140, expressed by stable and transient transfections using an integrated mass mapping workflow that combines collision induced dissociation (CID) and electron transfer dissociation (ETD). Site-specific analysis of the N- and O-glycosylation profiles revealed that C97ZA012 gp140 produced by both transfection methods displayed a high degree of similarity in N-glycosylation profiles and site occupancy except for one site. By contrast, different O-glycosylation profiles were detected. Analysis of the disulfide bond networks of the Env revealed that both transfection methods yielded C97ZA012 gp140 adopting the expected disulfide bond pattern identified for the monomeric gp120 and gp41 as well as alternative disulfide bond patterns in the C1, V1/V2, and C2 regions. The finding that disulfide bonding is consistently heterogeneous in these proteins is perhaps the most significant outcome of these studies; this disulfide heterogeneity has been reported for multiple other recombinant gp140s, and it is likely present in most recombinantly expressed Env immunogens.
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Affiliation(s)
- Eden P Go
- Department of Chemistry, University of Kansas , Lawrence, Kansas 66047, United States
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98
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Kim AS, Leaman DP, Zwick MB. Antibody to gp41 MPER alters functional properties of HIV-1 Env without complete neutralization. PLoS Pathog 2014; 10:e1004271. [PMID: 25058619 PMCID: PMC4110039 DOI: 10.1371/journal.ppat.1004271] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 06/11/2014] [Indexed: 01/08/2023] Open
Abstract
Human antibody 10E8 targets the conserved membrane proximal external region (MPER) of envelope glycoprotein (Env) subunit gp41 and neutralizes HIV-1 with exceptional potency. Remarkably, HIV-1 containing mutations that reportedly knockout 10E8 binding to linear MPER peptides are partially neutralized by 10E8, producing a local plateau in the dose response curve. Here, we found that virus partially neutralized by 10E8 becomes significantly less neutralization sensitive to various MPER antibodies and to soluble CD4 while becoming significantly more sensitive to antibodies and fusion inhibitors against the heptad repeats of gp41. Thus, 10E8 modulates sensitivity of Env to ligands both pre- and post-receptor engagement without complete neutralization. Partial neutralization by 10E8 was influenced at least in part by perturbing Env glycosylation. With unliganded Env, 10E8 bound with lower apparent affinity and lower subunit occupancy to MPER mutant compared to wild type trimers. However, 10E8 decreased functional stability of wild type Env while it had an opposite, stabilizing effect on MPER mutant Envs. Clade C isolates with natural MPER polymorphisms also showed partial neutralization by 10E8 with altered sensitivity to various gp41-targeted ligands. Our findings suggest a novel mechanism of virus neutralization by demonstrating how antibody binding to the base of a trimeric spike cross talks with adjacent subunits to modulate Env structure and function. The ability of an antibody to stabilize, destabilize, partially neutralize as well as alter neutralization sensitivity of a virion spike pre- and post-receptor engagement may have implications for immunotherapy and vaccine design.
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Affiliation(s)
- Arthur S. Kim
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Daniel P. Leaman
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael B. Zwick
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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99
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Pejawar-Gaddy S, Kovacs JM, Barouch DH, Chen B, Irvine DJ. Design of lipid nanocapsule delivery vehicles for multivalent display of recombinant Env trimers in HIV vaccination. Bioconjug Chem 2014; 25:1470-8. [PMID: 25020048 PMCID: PMC4140538 DOI: 10.1021/bc5002246] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
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Immunization strategies that elicit
antibodies capable of neutralizing
diverse virus strains will likely be an important part of a successful
vaccine against HIV. However, strategies to promote robust humoral
responses against the native intact HIV envelope trimer structure
are lacking. We recently developed chemically cross-linked lipid nanocapsules
as carriers of molecular adjuvants and encapsulated or surface-displayed
antigens, which promoted follicular helper T-cell responses and elicited
high-avidity, durable antibody responses to a candidate malaria antigen.
To apply this system to the delivery of HIV antigens, Env gp140 trimers
with terminal his-tags (gp140T-his) were anchored to the surface of
lipid nanocapsules via Ni-NTA-functionalized lipids. Initial experiments
revealed that the large (409 kDa), heavily glycosylated trimers were
capable of extracting fluid phase lipids from the membranes of nanocapsules.
Thus, liquid-ordered and/or gel-phase lipid compositions were required
to stably anchor trimers to the particle membranes. Trimer-loaded
nanocapsules combined with the clinically relevant adjuvant monophosphoryl
lipid A primed high-titer antibody responses in mice at antigen doses
ranging from 5 μg to as low as 100 ng, whereas titers dropped
more than 50-fold over the same dose range when soluble trimer was
mixed with a strong oil-in-water adjuvant comparator. Nanocapsule
immunization also broadened the number of distinct epitopes on the
HIV trimer recognized by the antibody response. These results suggest
that nanocapsules displaying HIV trimers in an oriented, multivalent
presentation can promote key aspects of the humoral response against
Env immunogens.
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Affiliation(s)
- Sharmila Pejawar-Gaddy
- Department of Biological Engineering, #Koch Institute for Integrative Cancer Research, and ¶Department of Material Science, Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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100
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Ringe R, Bhattacharya J. Preventive and therapeutic applications of neutralizing antibodies to Human Immunodeficiency Virus Type 1 (HIV-1). THERAPEUTIC ADVANCES IN VACCINES 2014; 1:67-80. [PMID: 24757516 DOI: 10.1177/2051013613494534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The development of a preventive vaccine to neutralize the highly variable and antigenically diverse human immunodeficiency virus type 1 (HIV-1) has been an indomitable goal. The recent discovery of a number of cross-neutralizing and potent monoclonal antibodies from elite neutralizers has provided important insights in this field. Neutralizing antibodies (NAbs) are useful in identifying neutralizing epitopes of vaccine utility and for understanding the mechanism of potent and broad cross-neutralization thus providing a modality of preventive and therapeutic value. In this article we review the current understanding on the potential use of broadly neutralizing antibodies (bNAbs) in their full-length IgG structure, engineered domain antibody or bispecific versions towards preventive and therapeutic applications. The potential implications of NAbs are discussed in the light of the recent developments as key components in vaccination against HIV-1. The development of a vaccine immunogen which elicits bNAbs and confers protective immunity remains a real challenge.
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Affiliation(s)
- Rajesh Ringe
- Weill Medical College of Cornell University, New York, NY, USA
| | - Jayanta Bhattacharya
- International AIDS Vaccine Initiative (IAVI), THSTI-IAVI HVTR Laboratory, Translational Health Science and Technology Institute (THSTI), Gurgaon-122016, Haryana, India
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