1
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Rao PG, Lambert GS, Upadhyay C. Broadly neutralizing antibody epitopes on HIV-1 particles are exposed after virus interaction with host cells. J Virol 2023; 97:e0071023. [PMID: 37681958 PMCID: PMC10537810 DOI: 10.1128/jvi.00710-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/07/2023] [Indexed: 09/09/2023] Open
Abstract
The envelope (Env) glycoproteins on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAbs) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes, including V2i, the gp120-g41 interface, and gp41-MPER, are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by the pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where the virus-mAb mix was pre-incubated/not pre-incubated for 1 hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use. IMPORTANCE The human immunodeficiency virus (HIV-1) envelope (Env) glycoprotein mediates viral entry and is the sole target of neutralizing antibodies. Our data suggest that antibody epitopes including V2q (e.g., PG9, PGT145), CD4bs (e.g., VRC01, 3BNC117), and V3 (2219, 2557) are masked on HIV-1 particles. The PG9 and 2219 epitopes became accessible for binding after conformational unmasking was induced by the pre-binding of select mAbs. Attempts to understand the masking mechanism led to the revelation that interaction between virus and host cells is needed to sensitize the virions for neutralization by broadly neutralizing antibodies (bNAbs). These data provide insight on how bNAbs may gain access to these occluded epitopes to exert their neutralization effects and block HIV-1 infection. These findings have important implications for the way we evaluate the neutralizing efficacy of antibodies and can potentially guide vaccine design.
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Affiliation(s)
- Priyanka Gadam Rao
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gregory S. Lambert
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Chitra Upadhyay
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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2
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Glögl M, Friedrich N, Cerutti G, Lemmin T, Kwon YD, Gorman J, Maliqi L, Mittl PRE, Hesselman MC, Schmidt D, Weber J, Foulkes C, Dingens AS, Bylund T, Olia AS, Verardi R, Reinberg T, Baumann NS, Rusert P, Dreier B, Shapiro L, Kwong PD, Plückthun A, Trkola A. Trapping the HIV-1 V3 loop in a helical conformation enables broad neutralization. Nat Struct Mol Biol 2023; 30:1323-1336. [PMID: 37605043 PMCID: PMC10497408 DOI: 10.1038/s41594-023-01062-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 07/11/2023] [Indexed: 08/23/2023]
Abstract
The third variable (V3) loop on the human immunodeficiency virus 1 (HIV-1) envelope glycoprotein trimer is indispensable for virus cell entry. Conformational masking of V3 within the trimer allows efficient neutralization via V3 only by rare, broadly neutralizing glycan-dependent antibodies targeting the closed prefusion trimer but not by abundant antibodies that access the V3 crown on open trimers after CD4 attachment. Here, we report on a distinct category of V3-specific inhibitors based on designed ankyrin repeat protein (DARPin) technology that reinstitute the CD4-bound state as a key neutralization target with up to >90% breadth. Broadly neutralizing DARPins (bnDs) bound V3 solely on open envelope and recognized a four-turn amphipathic α-helix in the carboxy-terminal half of V3 (amino acids 314-324), which we termed 'αV3C'. The bnD contact surface on αV3C was as conserved as the CD4 binding site. Molecular dynamics and escape mutation analyses underscored the functional relevance of αV3C, highlighting the potential of αV3C-based inhibitors and, more generally, of postattachment inhibition of HIV-1.
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Affiliation(s)
- Matthias Glögl
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Nikolas Friedrich
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Gabriele Cerutti
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Thomas Lemmin
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Young D Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Liridona Maliqi
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Peer R E Mittl
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Maria C Hesselman
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Daniel Schmidt
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Jacqueline Weber
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Caio Foulkes
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Adam S Dingens
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Tatsiana Bylund
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Adam S Olia
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thomas Reinberg
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Nicolas S Baumann
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Peter Rusert
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland
| | - Birgit Dreier
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Lawrence Shapiro
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich (UZH), Zurich, Switzerland
| | - Alexandra Trkola
- Institute for Medical Virology, University of Zurich (UZH), Zurich, Switzerland.
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3
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Rao PG, Lambert GS, Upadhyay C. Broadly Neutralizing Antibody Epitopes on HIV-1 Particles are exposed after Virus Interaction with Host Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524996. [PMID: 36711466 PMCID: PMC9882293 DOI: 10.1101/2023.01.20.524996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The envelope glycoproteins (Env) on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAb) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes including V2i, gp120-g41 interface, and gp41-MPER are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where virus-mAb mix was pre-incubated/not pre-incubated for one hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are the ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use.
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4
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Herschhorn A. Indirect Mechanisms of HIV-1 Evasion from Broadly Neutralizing Antibodies In Vivo. ACS Infect Dis 2023; 9:5-8. [PMID: 36512322 DOI: 10.1021/acsinfecdis.2c00573] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Alon Herschhorn
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Microbiology, Immunology, and Cancer Biology Graduate Program, University of Minnesota, Minneapolis, Minnesota 55455, United States.,The College of Veterinary Medicine Graduate Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
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5
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Abstract
Human immunodeficiency virus type 1 (HIV-1) envelope (Env), a heterotrimer of gp120-gp41 subunits, mediates fusion of the viral and host cell membranes after interactions with the host receptor CD4 and a coreceptor. CD4 binding induces rearrangements in Env trimer, resulting in a CD4-induced (CD4i) open Env conformation. Structural studies of antibodies isolated from infected donors have defined antibody-Env interactions, with one class of antibodies specifically recognizing the CD4i open Env conformation. In this study, we characterized a group of monoclonal antibodies isolated from HIV-1 infected donors (V2i MAbs) that displayed characteristics of CD4i antibodies. Binding experiments demonstrated that the V2i MAbs preferentially recognize CD4-bound open Env trimers. Structural characterizations of V2i MAb-Env-CD4 trimer complexes using single-particle cryo-electron microscopy showed recognition by V2i MAbs using different angles of approach to the gp120 V1V2 domain and the β2/β3 strands on a CD4i open conformation Env with no direct interactions of the MAbs with CD4. We also characterized CG10, a CD4i antibody that was raised in mice immunized with a gp120-CD4 complex, bound to an Env trimer plus CD4. CG10 exhibited characteristics similar to those of the V2i antibodies, i.e., recognition of the open Env conformation, but showed direct contacts to both CD4 and gp120. Structural comparisons of these and previously characterized CD4i antibody interactions with Env provide a suggested mechanism for how these antibodies are elicited during HIV-1 infection. IMPORTANCE The RV144 HIV-1 clinical vaccination trial showed modest protection against viral infection. Antibody responses to the V1V2 region of HIV-1 Env gp120 were correlated inversely with the risk of infection, and data from three other clinical vaccine trials suggested a similar signal. In addition, antibodies targeting V1V2 have been correlated with protections from simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus (SHIV) infections in nonhuman primates. We structurally characterized V2i antibodies directed against V1V2 isolated from HIV-1 infected humans in complex with open Env trimers bound to the host receptor CD4. We also characterized a CD4i antibody that interacts with CD4 as well as the gp120 subunit of an open Env trimer. Our study suggests how V2i and CD4i antibodies were elicited during HIV-1 infection.
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6
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Hodge EA, Naika GS, Kephart SM, Nguyen A, Zhu R, Benhaim MA, Guo W, Moore JP, Hu SL, Sanders RW, Lee KK. Structural dynamics reveal isolate-specific differences at neutralization epitopes on HIV Env. iScience 2022; 25:104449. [PMID: 35677643 PMCID: PMC9167985 DOI: 10.1016/j.isci.2022.104449] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/25/2022] [Accepted: 05/17/2022] [Indexed: 11/19/2022] Open
Abstract
The envelope glycoprotein (Env) is the sole target for neutralizing antibodies against HIV and the most rapidly evolving, variable part of the virus. High-resolution structures of Env trimers captured in the pre-fusion, closed conformation have revealed a high degree of structural similarity across diverse isolates. Biophysical data, however, indicate that Env is highly dynamic, and the level of dynamics and conformational sampling is believed to vary dramatically between HIV isolates. Dynamic differences likely influence neutralization sensitivity, receptor activation, and overall trimer stability. Here, using hydrogen/deuterium-exchange mass spectrometry (HDX-MS), we have mapped local dynamics across native-like Env SOSIP trimers from diverse isolates. We show that significant differences in epitope order are observed across most sites targeted by broadly neutralizing antibodies. We also observe isolate-dependent conformational switching that occurs over a broad range of timescales. Lastly, we report that hyper-stabilizing mutations that dampen dynamics in some isolates have little effect on others.
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Affiliation(s)
- Edgar A. Hodge
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Gajendra S. Naika
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Sally M. Kephart
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Adam Nguyen
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
- Biological Physics, Structure and Design Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Richard Zhu
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Mark A. Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Wenjin Guo
- Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA
| | - John P. Moore
- Division of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Shiu-Lok Hu
- Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA
| | - Rogier W. Sanders
- Division of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Kelly K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
- Biological Physics, Structure and Design Graduate Program, University of Washington, Seattle, WA 98195, USA
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7
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Global Increases in Human Immunodeficiency Virus Neutralization Sensitivity Due to Alterations in the Membrane-Proximal External Region of the Envelope Glycoprotein Can Be Minimized by Distant State 1-Stabilizing Changes. J Virol 2022; 96:e0187821. [PMID: 35289647 DOI: 10.1128/jvi.01878-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Binding to the receptor, CD4, drives the pretriggered, "closed" (State-1) conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ([gp120/gp41]3) into more "open" conformations. HIV-1 Env on the viral membrane is maintained in a State-1 conformation that resists binding and neutralization by commonly elicited antibodies. Premature triggering of Env before the virus engages a target cell typically leads to increased susceptibility to spontaneous inactivation or ligand-induced neutralization. Here, we showed that single amino acid substitutions in the gp41 membrane-proximal external region (MPER) of a primary HIV-1 strain resulted in viral phenotypes indicative of premature triggering of Env to downstream conformations. Specifically, the MPER changes reduced viral infectivity and globally increased virus sensitivity to poorly neutralizing antibodies, soluble CD4, a CD4-mimetic compound, and exposure to cold. In contrast, the MPER mutants exhibited decreased sensitivity to the State 1-preferring inhibitor, BMS-806, and to the PGT151 broadly neutralizing antibody. Depletion of cholesterol from virus particles did not produce the same State 1-destabilizing phenotypes as MPER alterations. Notably, State 1-stabilizing changes in Env distant from the MPER could minimize the phenotypic effects of MPER alteration but did not affect virus sensitivity to cholesterol depletion. Thus, membrane-proximal gp41 elements contribute to the maintenance of the pretriggered Env conformation. The conformationally disruptive effects of MPER changes can be minimized by distant State 1-stabilizing Env modifications, a strategy that may be useful in preserving the native pretriggered state of Env. IMPORTANCE The pretriggered shape of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) is a major target for antibodies that can neutralize many strains of the virus. An effective HIV-1 vaccine may need to raise these types of antibodies, but this goal has proven difficult. One reason is that the pretriggered shape of Env is unstable and dependent on interactions near the viral membrane. Here, we showed that the membrane-proximal external region (MPER) of Env plays an important role in maintaining Env in a pretriggered shape. Alterations in the MPER resulted in global changes in Env conformation that disrupted its pretriggered shape. We also found that these disruptive effects of MPER changes could be minimized by distant Env modifications that stabilized the pretriggered shape. These modifications may be useful for preserving the native shape of Env for structural and vaccine studies.
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8
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Weiss S, Itri V, Pan R, Jiang X, Luo CC, Morris L, Malherbe DC, Barnette P, Alexander J, Kong XP, Haigwood NL, Hessell AJ, Duerr R, Zolla-Pazner S. Differential V2-directed antibody responses in non-human primates infected with SHIVs or immunized with diverse HIV vaccines. Nat Commun 2022; 13:903. [PMID: 35173151 PMCID: PMC8850611 DOI: 10.1038/s41467-022-28450-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/25/2022] [Indexed: 11/24/2022] Open
Abstract
V2p and V2i antibodies (Abs) that are specific for epitopes in the V1V2 region of the HIV gp120 envelope (Env) do not effectively neutralize HIV but mediate Fc-dependent anti-viral activities that have been correlated with protection from, or control of HIV, SIV and SHIV infections. Here, we describe a novel molecular toolbox that allows the discrimination of antigenically and functionally distinct polyclonal V2 Ab responses. We identify different patterns of V2 Ab induction by SHIV infection and three separate vaccine regimens that aid in fine-tuning an optimized immunization protocol for inducing V2p and V2i Abs. We observe no, or weak and sporadic V2p and V2i Abs in non-vaccinated SHIV-infected NHPs, but strong V2p and/or V2i Ab responses after immunization with a V2-targeting vaccine protocol. The V2-focused vaccination is superior to both natural infection and to immunization with whole Env constructs for inducing functional V2p- and V2i-specific responses. Strikingly, levels of V2-directed Abs correlate inversely with Abs specific for peptides of V3 and C5. These data demonstrate that a V1V2-targeting vaccine has advantages over the imprecise targeting of SIV/SHIV infections and of whole Env-based immunization regimens for inducing a more focused functional V2p- and V2i-specific Ab response. Here the authors show that an HIV vaccine in non-human primates that focuses antibodies on the V1V2 region of gp120 is superior to infection or immunization with whole envelope vaccines for inducing V1V2 antibodies with anti-viral functions that correlate with protection.
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Affiliation(s)
- Svenja Weiss
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Vincenza Itri
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ruimin Pan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Xunqing Jiang
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Christina C Luo
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Lynn Morris
- National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham, Johannesburg, South Africa.,MRC Antibody Research Unit, University of the Witwatersrand, Johannesburg and Center for the AIDS Program of Research in South Africa, Johannesburg, South Africa
| | - Delphine C Malherbe
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA.,University of Texas Medical Branch, Department of Pathology, Galveston National Laboratory, Galveston, TX, USA
| | - Philip Barnette
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Jeff Alexander
- PaxVax Corporation, Redwood City, CA, USA.,JL Alexander Research and Development Consulting LLC, San Diego, CA, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Nancy L Haigwood
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Ann J Hessell
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Ralf Duerr
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Susan Zolla-Pazner
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Department of Microbiology, Icahn School of Medicine, New York, NY, USA.
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9
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Hioe CE, Li G, Liu X, Tsahouridis O, He X, Funaki M, Klingler J, Tang AF, Feyznezhad R, Heindel DW, Wang XH, Spencer DA, Hu G, Satija N, Prévost J, Finzi A, Hessell AJ, Wang S, Lu S, Chen BK, Zolla-Pazner S, Upadhyay C, Alvarez R, Su L. Non-neutralizing antibodies targeting the immunogenic regions of HIV-1 envelope reduce mucosal infection and virus burden in humanized mice. PLoS Pathog 2022; 18:e1010183. [PMID: 34986207 PMCID: PMC8765624 DOI: 10.1371/journal.ppat.1010183] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/18/2022] [Accepted: 12/09/2021] [Indexed: 02/07/2023] Open
Abstract
Antibodies are principal immune components elicited by vaccines to induce protection from microbial pathogens. In the Thai RV144 HIV-1 vaccine trial, vaccine efficacy was 31% and the sole primary correlate of reduced risk was shown to be vigorous antibody response targeting the V1V2 region of HIV-1 envelope. Antibodies against V3 also were inversely correlated with infection risk in subsets of vaccinees. Antibodies recognizing these regions, however, do not exhibit potent neutralizing activity. Therefore, we examined the antiviral potential of poorly neutralizing monoclonal antibodies (mAbs) against immunodominant V1V2 and V3 sites by passive administration of human mAbs to humanized mice engrafted with CD34+ hematopoietic stem cells, followed by mucosal challenge with an HIV-1 infectious molecular clone expressing the envelope of a tier 2 resistant HIV-1 strain. Treatment with anti-V1V2 mAb 2158 or anti-V3 mAb 2219 did not prevent infection, but V3 mAb 2219 displayed a superior potency compared to V1V2 mAb 2158 in reducing virus burden. While these mAbs had no or weak neutralizing activity and elicited undetectable levels of antibody-dependent cellular cytotoxicity (ADCC), V3 mAb 2219 displayed a greater capacity to bind virus- and cell-associated HIV-1 envelope and to mediate antibody-dependent cellular phagocytosis (ADCP) and C1q complement binding as compared to V1V2 mAb 2158. Mutations in the Fc region of 2219 diminished these effector activities in vitro and lessened virus control in humanized mice. These results demonstrate the importance of Fc functions other than ADCC for antibodies without potent neutralizing activity.
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Affiliation(s)
- Catarina E. Hioe
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- James J. Peters VA Medical Center, Bronx, New York, New York, United States of America
| | - Guangming Li
- Laboratory of Viral Pathogenesis and Immunotherapy, Division of Virology, Pathogenesis, and Cancer, Institute of Human Virology, Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Xiaomei Liu
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ourania Tsahouridis
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Xiuting He
- Laboratory of Viral Pathogenesis and Immunotherapy, Division of Virology, Pathogenesis, and Cancer, Institute of Human Virology, Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Masaya Funaki
- Laboratory of Viral Pathogenesis and Immunotherapy, Division of Virology, Pathogenesis, and Cancer, Institute of Human Virology, Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jéromine Klingler
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- James J. Peters VA Medical Center, Bronx, New York, New York, United States of America
| | - Alex F. Tang
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- School of Medicine, University of California, San Francisco, California, United States of America
| | - Roya Feyznezhad
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Daniel W. Heindel
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Xiao-Hong Wang
- VA New York Harbor Healthcare System–Manhattan, New York, New York, United States of America
| | - David A. Spencer
- Division of Pathobiology & Immunology, Oregon Health & Science University, Oregon National Primate Research Center, Beaverton, Oregon, United States of America
| | - Guangnan Hu
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Namita Satija
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jérémie Prévost
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Andrés Finzi
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Ann J. Hessell
- Division of Pathobiology & Immunology, Oregon Health & Science University, Oregon National Primate Research Center, Beaverton, Oregon, United States of America
| | - Shixia Wang
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Shan Lu
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Benjamin K. Chen
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Susan Zolla-Pazner
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Chitra Upadhyay
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Raymond Alvarez
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Lishan Su
- Laboratory of Viral Pathogenesis and Immunotherapy, Division of Virology, Pathogenesis, and Cancer, Institute of Human Virology, Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Laboratory of Viral Pathogenesis and Immunotherapy, Division of Virology, Pathogenesis and Cancer, Institute of Human Virology, Departments of Pharmacology and Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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10
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Zhang S, Wang K, Wang WL, Nguyen HT, Chen S, Lu M, Go EP, Ding H, Steinbock RT, Desaire H, Kappes JC, Sodroski J, Mao Y. Asymmetric Structures and Conformational Plasticity of the Uncleaved Full-Length Human Immunodeficiency Virus Envelope Glycoprotein Trimer. J Virol 2021; 95:e0052921. [PMID: 34549974 PMCID: PMC8610584 DOI: 10.1128/jvi.00529-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 09/06/2021] [Indexed: 11/20/2022] Open
Abstract
The functional human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer [(gp120/gp41)3] is produced by cleavage of a conformationally flexible gp160 precursor. gp160 cleavage or the binding of BMS-806, an entry inhibitor, stabilizes the pretriggered, "closed" (state 1) conformation recognized by rarely elicited broadly neutralizing antibodies. Poorly neutralizing antibodies (pNAbs) elicited at high titers during natural infection recognize more "open" Env conformations (states 2 and 3) induced by binding the receptor, CD4. We found that BMS-806 treatment and cross-linking decreased the exposure of pNAb epitopes on cell surface gp160; however, after detergent solubilization, cross-linked and BMS-806-treated gp160 sampled non-state-1 conformations that could be recognized by pNAbs. Cryo-electron microscopy of the purified BMS-806-bound gp160 revealed two hitherto unknown asymmetric trimer conformations, providing insights into the allosteric coupling between trimer opening and structural variation in the gp41 HR1N region. The individual protomer structures in the asymmetric gp160 trimers resemble those of other genetically modified or antibody-bound cleaved HIV-1 Env trimers, which have been suggested to assume state-2-like conformations. Asymmetry of the uncleaved Env potentially exposes surfaces of the trimer to pNAbs. To evaluate the effect of stabilizing a state-1-like conformation of the membrane Env precursor, we treated cells expressing wild-type HIV-1 Env with BMS-806. BMS-806 treatment decreased both gp160 cleavage and the addition of complex glycans, implying that gp160 conformational flexibility contributes to the efficiency of these processes. Selective pressure to maintain flexibility in the precursor of functional Env allows the uncleaved Env to sample asymmetric conformations that potentially skew host antibody responses toward pNAbs. IMPORTANCE The envelope glycoprotein (Env) trimers on the surface of human immunodeficiency virus (HIV-1) mediate the entry of the virus into host cells and serve as targets for neutralizing antibodies. The functional Env trimer is produced by cleavage of the gp160 precursor in the infected cell. We found that the HIV-1 Env precursor is highly plastic, allowing it to assume different asymmetric shapes. This conformational plasticity is potentially important for Env cleavage and proper modification by sugars. Having a flexible, asymmetric Env precursor that can misdirect host antibody responses without compromising virus infectivity would be an advantage for a persistent virus like HIV-1.
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Affiliation(s)
- Shijian Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Kunyu Wang
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
| | - Wei Li Wang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
- Intel Parallel Computing Center for Structural Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Hanh T. Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shuobing Chen
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Eden P. Go
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
| | - Robert T. Steinbock
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Heather Desaire
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Center for Quantitative Biology, Peking University, Beijing, China
- Intel Parallel Computing Center for Structural Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
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11
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Uversky VN, Van Regenmortel MHV. Mobility and disorder in antibody and antigen binding sites do not prevent immunochemical recognition. Crit Rev Biochem Mol Biol 2021; 56:149-156. [PMID: 33455453 DOI: 10.1080/10409238.2020.1869683] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The known polyspecificity of antibodies, which is crucial for efficient immune response, is determined by the conformational flexibility and intrinsic disorder encoded in local peculiarities of the amino acid sequence of antibodies within or in the vicinity of their complementarity determining regions. Similarly, epitopes represent fuzzy binding sites, which are also characterized by local structural flexibility. Existing data suggest that the efficient interactions between antigens and antibodies rely on the conformational mobility and some disorder of their binding sites and therefore can be relatively well described by the "flexible lock - adjustable key" model, whereas both, extreme order (rigid lock-and-key) and extreme disorder (viral shape-shifters) are not compatible with the efficient antigen-antibody interactions and are not present in immune interactions.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Russia
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12
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Signal peptide of HIV-1 envelope modulates glycosylation impacting exposure of V1V2 and other epitopes. PLoS Pathog 2020; 16:e1009185. [PMID: 33370382 PMCID: PMC7793277 DOI: 10.1371/journal.ppat.1009185] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/08/2021] [Accepted: 11/24/2020] [Indexed: 11/19/2022] Open
Abstract
HIV-1 envelope (Env) is a trimer of gp120-gp41 heterodimers, synthesized from a precursor gp160 that contains an ER-targeting signal peptide (SP) at its amino-terminus. Each trimer is swathed by ~90 N-linked glycans, comprising complex-type and oligomannose-type glycans, which play an important role in determining virus sensitivity to neutralizing antibodies. We previously examined the effects of single point SP mutations on Env properties and functions. Here, we aimed to understand the impact of the SP diversity on glycosylation of virus-derived Env and virus neutralization by swapping SPs. Analyses of site-specific glycans revealed that SP swapping altered Env glycan content and occupancy on multiple N-linked glycosites, including conserved N156 and N160 glycans in the V1V2 region at the Env trimer apex and N88 at the trimer base. Virus neutralization was also affected, especially by antibodies against V1V2, V3, and gp41. Likewise, SP swaps affected the recognition of soluble and cell-associated Env by antibodies targeting distinct V1V2 configurations, V3 crown, and gp41 epitopes. These data highlight the contribution of SP sequence diversity in shaping the Env glycan content and its impact on the configuration and accessibility of V1V2 and other Env epitopes. HIV-1 Env glycoprotein is produced by a precursor gp160 that has a signal peptide at its N-terminus. The SP is highly diverse among the HIV-1 isolates. This study presents site-specific analyses of N-linked glycosylation on HIV-1 envelope glycoproteins from infectious viruses produced with different envelope signal peptides. We show that signal peptide swapping alters the envelope glycan shield, including the conserved N156 and N160 glycans located in the V1V2 region on the trimer apex, to impact Env recognition and virus neutralization by antibodies. The data offer crucial insights into the role of signal peptide in the interplay between HIV-1 and antibodies and its potential utility to control Env glycosylation in the development of Env-based HIV-1 vaccine.
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13
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The Conformational States of the HIV-1 Envelope Glycoproteins. Trends Microbiol 2020; 28:655-667. [PMID: 32418859 DOI: 10.1016/j.tim.2020.03.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 03/25/2020] [Indexed: 12/16/2022]
Abstract
During HIV-1 entry into target cells, binding of the virus to host receptors, CD4 and CCR5/CXCR4, triggers serial conformational changes in the envelope glycoprotein (Env) trimer that result in the fusion of the viral and cell membranes. Recent discoveries have refined our knowledge of Env conformational states, allowing characterization of the targets of small-molecule HIV-1 entry inhibitors and neutralizing antibodies, and identifying a novel off-pathway conformation (State 2A). Here, we provide an overview of the current understanding of these conformational states, focusing on (i) the events during HIV-1 entry; (ii) conformational preferences of HIV-1 Env ligands; (iii) evasion of the host antibody response; and (iv) potential implications for therapy and prevention of HIV-1 infection.
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14
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Lai JI, Eszterhas SK, Brooks SA, Guo C, Zolla-Pazner S, Seaman MS, Bailey-Kellogg C, Griswold KE, Ackerman ME. Induction of cross-reactive HIV-1 specific antibody responses by engineered V1V2 immunogens with reduced conformational plasticity. Vaccine 2020; 38:3436-3446. [PMID: 32192810 PMCID: PMC7132531 DOI: 10.1016/j.vaccine.2020.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/26/2020] [Accepted: 03/03/2020] [Indexed: 01/13/2023]
Abstract
Antibodies against the HIV-1 V1V2 loops were the only correlate of reduced infection risk in the RV144 vaccine trial, highlighting the V1V2 loops as promising targets for vaccine design. The V1V2 loops are structurally plastic, exhibiting either an α-helix-coil or β-strand conformation. V1V2-specific antibodies may thus recognize distinct conformations, and an antibody's conformational specificity can be an important determinant of breadth and function. Restricting V1V2 conformational plasticity in an immunogen may thus provide control over the conformational specificity and quality of a vaccine-elicited antibody response. Previously, we identified a V1V2 sequence variant (K155M) that results in enhanced recognition by cross-reactive antibodies recognizing the β-strand conformation. Here, we relate V1V2 antigenicity to immunogenicity by comparing the immunogenicity profiles of wildtype and K155M immunogens in two mouse models. In one model, immunization with gp70 V1V2 K155M but not wildtype elicited antibody responses that were cross-reactive to a panel of heterologous gp120 and gp140 antigens. In a second model, we compared the effect of K155M on immunogenicity in the context of gp70 V1V2, gD V1V2 and gp120, examining the effects of scaffold, epitope-focusing and immunization regimen. K155M variants, especially in the context of a gp120 immunogen, resulted in more robust, durable and cross-reactive antibody responses than wildtype immunogens. Restriction of the β-stranded V1V2 conformation in K155M immunogens may thus be associated with the induction of cross-reactive antibody responses thought to be required of a protective HIV-1 vaccine.
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Affiliation(s)
- Jennifer I Lai
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | | | - Seth A Brooks
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Chengzi Guo
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Susan Zolla-Pazner
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | - Karl E Griswold
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Margaret E Ackerman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA; Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.
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15
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Easterhoff D, Pollara J, Luo K, Janus B, Gohain N, Williams LD, Tay MZ, Monroe A, Peachman K, Choe M, Min S, Lusso P, Zhang P, Go EP, Desaire H, Bonsignori M, Hwang KK, Beck C, Kakalis M, O’Connell RJ, Vasan S, Kim JH, Michael NL, Excler JL, Robb ML, Rerks-Ngarm S, Kaewkungwal J, Pitisuttithum P, Nitayaphan S, Sinangil F, Tartaglia J, Phogat S, Wiehe K, Saunders KO, Montefiori DC, Tomaras GD, Moody MA, Arthos J, Rao M, Joyce MG, Ofek G, Ferrari G, Haynes BF. HIV vaccine delayed boosting increases Env variable region 2-specific antibody effector functions. JCI Insight 2020; 5:131437. [PMID: 31996483 PMCID: PMC7098725 DOI: 10.1172/jci.insight.131437] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 12/19/2019] [Indexed: 01/07/2023] Open
Abstract
In the RV144 HIV-1 phase III trial, vaccine efficacy directly correlated with the magnitude of the variable region 2-specific (V2-specific) IgG antibody response, and in the presence of low plasma IgA levels, with the magnitude of plasma antibody-dependent cellular cytotoxicity. Reenrollment of RV144 vaccinees in the RV305 trial offered the opportunity to define the function, maturation, and persistence of vaccine-induced V2-specific and other mAb responses after boosting. We show that the RV144 vaccine regimen induced persistent V2 and other HIV-1 envelope-specific memory B cell clonal lineages that could be identified throughout the approximately 11-year vaccination period. Subsequent boosts increased somatic hypermutation, a critical requirement for antibody affinity maturation. Characterization of 22 vaccine-induced V2-specific mAbs with epitope specificities distinct from previously characterized RV144 V2-specific mAbs CH58 and CH59 found increased in vitro antibody-mediated effector functions. Thus, when inducing non-neutralizing antibodies, one method by which to improve HIV-1 vaccine efficacy may be through late boosting to diversify the V2-specific response to increase the breadth of antibody-mediated anti-HIV-1 effector functions.
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Affiliation(s)
- David Easterhoff
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Medicine and
| | | | - Kan Luo
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | - Benjamin Janus
- Department of Surgery, Duke University School of Medicine, Duke University, Durham, North Carolina, USA
| | - Neelakshi Gohain
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | | | - Matthew Zirui Tay
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | - Anthony Monroe
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | - Kristina Peachman
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Misook Choe
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Susie Min
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Paolo Lusso
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Peng Zhang
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Eden P. Go
- National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - Heather Desaire
- National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - Mattia Bonsignori
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Medicine and
| | - Kwan-Ki Hwang
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | - Charles Beck
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | - Matina Kakalis
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | | | - Sandhya Vasan
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Jerome H. Kim
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
| | - Nelson L. Michael
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Jean-Louis Excler
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Merlin L. Robb
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Supachai Rerks-Ngarm
- US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Punnee Pitisuttithum
- Mahidol Bangkok School of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sorachai Nitayaphan
- Mahidol Bangkok School of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - James Tartaglia
- Global Solutions for Infectious Diseases, South San Francisco, California, USA
| | - Sanjay Phogat
- Global Solutions for Infectious Diseases, South San Francisco, California, USA
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Medicine and
| | | | | | - Georgia D. Tomaras
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
| | - M. Anthony Moody
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Duke University, Durham, North Carolina, USA
| | - James Arthos
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Mangala Rao
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
| | - M. Gordon Joyce
- Department of Cell Biology and Molecular Genetics, College of Computational, Biological, and Natural Sciences, and Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Rockville, Maryland, USA
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Gilad Ofek
- Department of Surgery, Duke University School of Medicine, Duke University, Durham, North Carolina, USA
| | | | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Medicine and
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16
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Jan M, Upadhyay C, Hioe CE. HIV-1 Envelope Glycan Composition as a Key Determinant of Efficient Virus Transmission via DC-SIGN and Resistance to Inhibitory Lectins. iScience 2019; 21:413-427. [PMID: 31704652 PMCID: PMC6889591 DOI: 10.1016/j.isci.2019.10.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/17/2019] [Accepted: 10/15/2019] [Indexed: 02/04/2023] Open
Abstract
The HIV-1 envelope (Env) surface is shrouded with an assortment of oligomannose-, hybrid-, and complex-type glycans that enable virus interaction with carbohydrate-recognizing lectins. This study examined the importance of glycan heterogeneity for HIV-1 transmission through the trans-infection pathway by the host mannose-binding lectin DC-SIGN. A diversity of glycan content was observed among HIV-1 strains and associated with varying degrees of trans-infection via DC-SIGN and sensitivity to trans-infection blockage by antiviral lectins. When Env glycans were modified to display only the oligomannose type, DC-SIGN-mediated virus capture was enhanced; however, virus trans-infection was diminished because of increased degradation, which was alleviated by incorporation with hybrid-type glycans. Amino acid changes in the Env signal peptide (SP) modulated the Env glycan content, leading to alterations in DC-SIGN-dependent trans-infection and virus sensitivity to antiviral lectins. Hence, SP variation and glycosylation that confer varied types of oligosaccharides to HIV-1 Env are critical determinants for virus fitness and phenotypic diversity.
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Affiliation(s)
- Muzafar Jan
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chitra Upadhyay
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA,Research Service, James J. Peters VA Medical Center, Bronx, NY 10468, USA
| | - Catarina E. Hioe
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA,Research Service, James J. Peters VA Medical Center, Bronx, NY 10468, USA,Corresponding author
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17
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Duerr R, Gorny MK. V2-Specific Antibodies in HIV-1 Vaccine Research and Natural Infection: Controllers or Surrogate Markers. Vaccines (Basel) 2019; 7:vaccines7030082. [PMID: 31390725 PMCID: PMC6789775 DOI: 10.3390/vaccines7030082] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/26/2019] [Accepted: 07/27/2019] [Indexed: 12/20/2022] Open
Abstract
Most human immunodeficiency virus (HIV) vaccine trials have lacked efficacy and empirical vaccine lead targets are scarce. Thus far, the only independent correlate of reduced risk of HIV-1 acquisition in humans is elevated levels of V2-specific antibodies identified in the modestly protective RV144 vaccine trial. Ten years after RV144, human and non-human primate vaccine studies have reassessed the potential contribution of V2-specific antibodies to vaccine efficacy. In addition, studies of natural HIV-1 infection in humans have provided insight into the development of V1V2-directed antibody responses and their impact on clinical parameters and disease progression. Functionally diverse anti-V2 monoclonal antibodies were isolated and their structurally distinct V2 epitope regions characterized. After RV144, a plethora of research studies were performed using different model systems, immunogens, protocols, and challenge viruses. These diverse studies failed to provide a clear picture regarding the contribution of V2 antibodies to vaccine efficacy. Here, we summarize the biological functions and clinical findings associated with V2-specific antibodies and discuss their impact on HIV vaccine research.
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Affiliation(s)
- Ralf Duerr
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
| | - Miroslaw K Gorny
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
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18
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Difficult-to-neutralize global HIV-1 isolates are neutralized by antibodies targeting open envelope conformations. Nat Commun 2019; 10:2898. [PMID: 31263112 PMCID: PMC6602974 DOI: 10.1038/s41467-019-10899-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 06/03/2019] [Indexed: 12/21/2022] Open
Abstract
The HIV-1 envelope (Env) is the target for neutralizing antibodies and exists on the surface of virions in open or closed conformations. Difficult-to-neutralize viruses (tier 2) express Env in a closed conformation antigenic for broadly neutralizing antibodies (bnAbs) but not for third variable region (V3) antibodies. Here we show that select V3 macaque antibodies elicited by Env vaccination can neutralize 26% of otherwise tier 2 HIV-1 isolates in standardized virus panels. The V3 antibodies only bound to Env in its open conformation. Thus, Envs on tier 2 viruses sample a state where the V3 loop is not in its closed conformation position. Envelope second variable region length, glycosylation sites and V3 amino acids were signatures of neutralization sensitivity. This study determined that open conformations of Env with V3 exposed are present on a subset of otherwise neutralization-resistant virions, therefore neutralization of tier 2 HIV-1 does not always indicate bnAb induction.
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19
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Kamau E, Bonneau R, Kong XP. Computational-guided determination of the functional role of 447-52D long CDRH3. Protein Eng Des Sel 2018; 31:479-487. [PMID: 31038677 PMCID: PMC6890530 DOI: 10.1093/protein/gzz007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/06/2019] [Accepted: 03/20/2019] [Indexed: 11/13/2022] Open
Abstract
447-52D (447) is a human monoclonal antibody that recognizes a conserved epitope in the crown region of the third variable loop (V3) of HIV-1 gp120, and like many anti-HIV-1 antibodies with broad neutralization capabilities, it has a long heavy-chain complementarity determining region (CDRH3). Here, we use a combination of computational mutagenesis and modeling in tandem with fluorescence polarization assays to interrogate the molecular basis of 447 CDRH3 length and the individual contribution of selected CDRH3 residues to affinity. We observe that 447 CDRH3 length provides a large binding surface area and the best enthalpic contributions derived from hydrophobic packing, main-chain hydrogen bonds, electrostatic and van der Waals interactions. We also found out that CDRH3 residue Try100I is critical to 447 binding affinity.
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Affiliation(s)
- Edwin Kamau
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York NY, USA
| | - Richard Bonneau
- Department of Biology, Center for Genomics and Systems Biology and Computer Science Department, Courant Institute of Mathematical Sciences, New York University, New York NY, USA
- Center for Computational Biology, Flatiron Institute, New York NY, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York NY, USA
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20
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Hioe CE, Kumar R, Upadhyay C, Jan M, Fox A, Itri V, Peachman KK, Rao M, Liu L, Lo NC, Tuen M, Jiang X, Kong XP, Zolla-Pazner S. Modulation of Antibody Responses to the V1V2 and V3 Regions of HIV-1 Envelope by Immune Complex Vaccines. Front Immunol 2018; 9:2441. [PMID: 30416503 PMCID: PMC6212562 DOI: 10.3389/fimmu.2018.02441] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 10/02/2018] [Indexed: 12/22/2022] Open
Abstract
Prophylactic HIV vaccines must elicit antibodies (Abs) against the virus envelope glycoproteins (Env) to effectively prevent HIV infection. We investigated a vaccine platform that utilizes immune complexes made of Env proteins gp120 and monoclonal Abs (mAbs) against different gp120 epitopes. We previously observed alterations in V3 antigenicity upon formation of certain gp120/mAb complexes and demonstrated the ability of these complexes to modulate the elicitation of V3 Ab responses. However, the effects on the V1V2 domain, an important target for Abs that correlate with vaccine-induced protection against HIV, have not been studied, nor have immune complex vaccines made with non-B subtype Env. This study compared subtypes B (JRFL) and CRF_01.AE (A244) Env gp120 proteins in complex with selected gp120-specific mAbs. Allosteric and antigenic changes were detected on these immune complexes, indicating that gp120/mAb interaction induces alterations on the Env surface that may modify the Env immunogenic properties. To evaluate this idea, mice were immunized with gp120/mAb complexes or their uncomplexed gp120 counterparts. The overall serum IgG titers elicited against gp120 were comparable, but a marked skewing toward V1V2 or V3 was evident and dependent on the gp120 strain and the specificity of the mAb used to form the complexes. Compared with uncomplexed gp120JRFL, gp120JRFL complexed with CD4bs or V1V2 mAbs, but not with C2 or V3 mAbs, elicited V3 Abs of greater titers and breadth, and Abs more capable of neutralizing tier 1 virus. Epitope mapping revealed a shift to a more conserved site in the V3 crown. However, the complexes did not enhance V1V2 Ab response, and the elicited V1V2 Abs were not cross-reactive. This profile contrasts with Ab responses to gp120A244/mAb complexes. Notably, gp120A244/mAb complexes induced higher levels of V1V2 Abs with some cross-reactivity, while also stimulating weak or strain-specific V3 Abs. Sera from gp120A244/mAb complex-immunized animals displayed no measurable virus neutralization but did mediate Ab-dependent cellular phagocytosis, albeit at levels similar to that induced by gp120A244 alone. These data indicate the potential utility of immune complexes as vaccines to shape Ab responses toward or away from Env sites of interest.
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Affiliation(s)
- Catarina E Hioe
- Icahn School of Medicine at Mount Sinai, New York, NY, United States.,James J. Peters VA Medical Center, Bronx, NY, United States
| | - Rajnish Kumar
- Icahn School of Medicine at Mount Sinai, New York, NY, United States.,James J. Peters VA Medical Center, Bronx, NY, United States
| | - Chitra Upadhyay
- Icahn School of Medicine at Mount Sinai, New York, NY, United States.,James J. Peters VA Medical Center, Bronx, NY, United States
| | - Muzafar Jan
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Alisa Fox
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Vincenza Itri
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kristina K Peachman
- United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Mangala Rao
- United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Lily Liu
- Department of Pathology, New York University School of Medicine, New York, NY, United States
| | - Nathan C Lo
- Department of Pathology, New York University School of Medicine, New York, NY, United States
| | - Michael Tuen
- Department of Pathology, New York University School of Medicine, New York, NY, United States
| | - Xunqing Jiang
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, United States
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, United States
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21
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Flemming J, Wiesen L, Herschhorn A. Conformation-Dependent Interactions Between HIV-1 Envelope Glycoproteins and Broadly Neutralizing Antibodies. AIDS Res Hum Retroviruses 2018; 34:794-803. [PMID: 29905080 DOI: 10.1089/aid.2018.0102] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
HIV type 1 (HIV-1) envelope glycoproteins (Env) mediate virus entry and are the target of neutralizing antibodies. Binding of the metastable HIV-1 Env trimer to the CD4 receptor triggers structural rearrangements that mediate Env conformational transitions from a closed conformation to a more open state through an intermediate step. Recent studies have revealed new insights on the dynamics, regulation, and molecular mechanisms of Env transitions along the entry pathway. In this study, we provide an overview of the current knowledge on Env conformational dynamics and the relationship between Env conformational states and neutralization selectivity of the broadly neutralizing antibodies that develop in 10%-20% of infected individuals and may provide guidance for the development of an effective HIV-1 vaccine.
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Affiliation(s)
- Juliana Flemming
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Lisa Wiesen
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Alon Herschhorn
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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22
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Upadhyay C, Feyznezhad R, Yang W, Zhang H, Zolla-Pazner S, Hioe CE. Alterations of HIV-1 envelope phenotype and antibody-mediated neutralization by signal peptide mutations. PLoS Pathog 2018; 14:e1006812. [PMID: 29370305 PMCID: PMC5800646 DOI: 10.1371/journal.ppat.1006812] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 02/06/2018] [Accepted: 12/14/2017] [Indexed: 11/18/2022] Open
Abstract
HIV-1 envelope glycoprotein (Env) mediates virus attachment and entry into the host cells. Like other membrane-bound and secreted proteins, HIV-1 Env contains at its N terminus a signal peptide (SP) that directs the nascent Env to the endoplasmic reticulum (ER) where Env synthesis and post-translational modifications take place. SP is cleaved during Env biosynthesis but potentially influences the phenotypic traits of the Env protein. The Env SP sequences of HIV-1 isolates display high sequence variability, and the significance of such variability is unclear. We postulate that changes in the Env SP influence Env transport through the ER-Golgi secretory pathway and Env folding and/or glycosylation that impact on Env incorporation into virions, receptor binding and antibody recognition. We first evaluated the consequences of mutating the charged residues in the Env SP in the context of infectious molecular clone HIV-1 REJO.c/2864. Results show that three different mutations affecting histidine at position 12 affected Env incorporation into virions that correlated with reduction of virus infectivity and DC-SIGN-mediated virus capture and transmission. Mutations at positions 8, 12, and 15 also rendered the virus more resistant to neutralization by monoclonal antibodies against the Env V1V2 region. These mutations affected the oligosaccharide composition of N-glycans as shown by changes in Env reactivity with specific lectins and by mass spectrometry. Increased neutralization resistance and N-glycan composition changes were also observed when analogous mutations were introduced to another HIV-1 strain, JRFL. To the best of our knowledge, this is the first study showing that certain residues in the HIV-1 Env SP can affect virus neutralization sensitivity by modulating oligosaccharide moieties on the Env N-glycans. The HIV-1 Env SP sequences thus may be under selective pressure to balance virus infectiousness with virus resistance to the host antibody responses. (289 words) HIV-1 envelope glycoprotein (Env) is indispensable for virus infection. HIV-1 Env contains at its N terminus a signal peptide (SP) that directs the protein to the endoplasmic reticulum. The SP sequences exhibits high variability among HIV-1 isolates, and the significance of such variability is unclear. We hypothesize that changes in the Env SP influence the Env biogenesis, Env folding and/or glycosylation and the phenotypic traits of the virus. This study evaluated the consequences of mutations in the Env SP of infectious molecular clone HIV-1 REJO.c/2864. Results show that three different mutations affecting histidine at position 12 impacted on the Env incorporation into virions that correlated with virus infectivity and transmission. Additionally, Env SP mutations at positions 8, 12, and 15 increased virus resistance to neutralization by Env monoclonal antibodies. These mutations also altered the oligosaccharide composition of N-glycans on Env as shown by changes in the Env reactivity with lectins and by mass spectrometry. Similar phenotypic changes were observed when analogous SP mutations were introduced to another virus strain, JRFL. Thus, the HIV-1 Env SP controls Env expression and glycosylation that affect virus infectivity, transmission, and sensitivity to neutralization by antibodies. (191 words)
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Affiliation(s)
- Chitra Upadhyay
- Icahn School of Medicine at Mount Sinai, Division of Infectious Diseases, New York, New York, United States of America
- * E-mail: (CU); (CEH)
| | - Roya Feyznezhad
- Icahn School of Medicine at Mount Sinai, Division of Infectious Diseases, New York, New York, United States of America
| | - Weiming Yang
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Hui Zhang
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Susan Zolla-Pazner
- Icahn School of Medicine at Mount Sinai, Division of Infectious Diseases, New York, New York, United States of America
| | - Catarina E. Hioe
- Icahn School of Medicine at Mount Sinai, Division of Infectious Diseases, New York, New York, United States of America
- James J. Peters Veterans Affairs Medical Center, Research Service, Bronx, New York, United States of America
- * E-mail: (CU); (CEH)
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23
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Functional Antibody Response Against V1V2 and V3 of HIV gp120 in the VAX003 and VAX004 Vaccine Trials. Sci Rep 2018; 8:542. [PMID: 29323175 PMCID: PMC5765017 DOI: 10.1038/s41598-017-18863-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/18/2017] [Indexed: 11/09/2022] Open
Abstract
Immunization with HIV AIDSVAX gp120 vaccines in the phase III VAX003 and VAX004 trials did not confer protection. To understand the shortcomings in antibody (Ab) responses induced by these vaccines, we evaluated the kinetics of Ab responses to the V1V2 and V3 regions of gp120 and the induction of Ab-mediated antiviral functions during the course of 7 vaccinations over a 30.5-month period. Plasma samples from VAX003 and VAX004 vaccinees and placebo recipients were measured for ELISA-binding Abs and for virus neutralization, Ab-dependent cellular phagocytosis (ADCP), and Ab-dependent cellular cytotoxicity (ADCC). Ab responses to V1V2 and V3 peaked after 3 to 4 immunizations and declined after 5 to 7 immunizations. The deteriorating responses were most evident against epitopes in the underside of the V1V2 β-barrel and in the V3 crown. Correspondingly, vaccinees demonstrated higher neutralization against SF162 pseudovirus sensitive to anti-V1V2 and anti-V3 Abs after 3 or 4 immunizations than after 7 immunizations. Higher levels of ADCP and ADCC were also observed at early or mid-time points as compared with the final time point. Hence, VAX003 and VAX004 vaccinees generated V1V2- and V3-binding Abs and functional Abs after 3 to 4 immunizations, but subsequent boosts did not maintain these responses.
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24
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Functional Stability of HIV-1 Envelope Trimer Affects Accessibility to Broadly Neutralizing Antibodies at Its Apex. J Virol 2017; 91:JVI.01216-17. [PMID: 28978711 DOI: 10.1128/jvi.01216-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/29/2017] [Indexed: 02/07/2023] Open
Abstract
The trimeric envelope glycoprotein spike (Env) of HIV-1 is the target of vaccine development to elicit broadly neutralizing antibodies (bnAbs). Env trimer instability and heterogeneity in principle make subunit interfaces inconsistent targets for the immune response. Here, we investigate how functional stability of Env relates to neutralization sensitivity to V2 bnAbs and V3 crown antibodies that engage subunit interfaces upon binding to unliganded Env. Env heterogeneity was inferred when antibodies neutralized a mutant Env with a plateau of less than 100% neutralization. A statistically significant correlation was found between the stability of mutant Envs and the MPN of V2 bnAb, PG9, as well as an inverse correlation between stability of Env and neutralization by V3 crown antibody, 447-52D. A number of Env-stabilizing mutations and V2 bnAb-enhancing mutations were identified in Env, but they did not always overlap, indicating distinct requirements of functional stabilization versus antibody recognition. Blocking complex glycosylation of Env affected V2 bnAb recognition, as previously described, but also notably increased functional stability of Env. This study shows how instability and heterogeneity affect antibody sensitivity of HIV-1 Env, which is relevant to vaccine design involving its dynamic apex.IMPORTANCE The Env trimer is the only viral protein on the surface of HIV-1 and is the target of neutralizing antibodies that reduce viral infectivity. Quaternary epitopes at the apex of the spike are recognized by some of the most potent and broadly neutralizing antibodies to date. Being that their glycan-protein hybrid epitopes are at subunit interfaces, the resulting heterogeneity can lead to partial neutralization. Here, we screened for mutations in Env that allowed for complete neutralization by the bnAbs. We found that when mutations outside V2 increased V2 bnAb recognition, they often also increased Env stability-of-function and decreased binding by narrowly neutralizing antibodies to the V3 crown. Three mutations together increased neutralization by V2 bnAb and eliminated binding by V3 crown antibodies. These results may aid the design of immunogens that elicit antibodies to the trimer apex.
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25
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HIV-1 Cross-Reactive Primary Virus Neutralizing Antibody Response Elicited by Immunization in Nonhuman Primates. J Virol 2017; 91:JVI.00910-17. [PMID: 28835491 DOI: 10.1128/jvi.00910-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/10/2017] [Indexed: 12/15/2022] Open
Abstract
Elicitation of broadly neutralizing antibody (bNAb) responses is a major goal for the development of an HIV-1 vaccine. Current HIV-1 envelope glycoprotein (Env) vaccine candidates elicit predominantly tier 1 and/or autologous tier 2 virus neutralizing antibody (NAb) responses, as well as weak and/or sporadic cross-reactive tier 2 virus NAb responses with unknown specificity. To delineate the specificity of vaccine-elicited cross-reactive tier 2 virus NAb responses, we performed single memory B cell sorting from the peripheral blood of a rhesus macaque immunized with YU2gp140-F trimers in adjuvant, using JR-FL SOSIP.664, a native Env trimer mimetic, as a sorting probe to isolate monoclonal Abs (MAbs). We found striking genetic and functional convergence of the SOSIP-sorted Ig repertoire, with predominant VH4 or VH5 gene family usage and Env V3 specificity. Of these vaccine-elicited V3-specific MAbs, nearly 20% (6/33) displayed cross-reactive tier 2 virus neutralization, which recapitulated the serum neutralization capacity. Substantial similarities in binding specificity, neutralization breadth and potency, and sequence/structural homology were observed between selected macaque cross-reactive V3 NAbs elicited by vaccination and prototypic V3 NAbs derived from natural infections in humans, highlighting the convergence of this subset of primate V3-specific B cell repertories. Our study demonstrated that cross-reactive primary virus neutralizing B cell lineages could be elicited by vaccination as detected using a standardized panel of tier 2 viruses. Whether these lineages could be expanded to acquire increased breadth and potency of neutralization merits further investigation.IMPORTANCE Elicitation of antibody responses capable of neutralizing diverse HIV-1 primary virus isolates (designated broadly neutralizing antibodies [bNAbs]) remains a high priority for the vaccine field. bNAb responses were so far observed only in response to natural infection within a subset of individuals. To achieve this goal, an improved understanding of vaccine-elicited responses, including at the monoclonal Ab level, is essential. Here, we isolated and characterized a panel of vaccine-elicited cross-reactive neutralizing MAbs targeting the Env V3 loop that moderately neutralized several primary viruses and recapitulated the serum neutralizing antibody response. Striking similarities between the cross-reactive V3 NAbs elicited by vaccination in macaques and natural infections in humans illustrate commonalities between the vaccine- and infection-induced responses to V3 and support the feasibility of exploring the V3 epitope as a HIV-1 vaccine target in nonhuman primates.
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26
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Mayr LM, Decoville T, Schmidt S, Laumond G, Klingler J, Ducloy C, Bahram S, Zolla-Pazner S, Moog C. Non-neutralizing Antibodies Targeting the V1V2 Domain of HIV Exhibit Strong Antibody-Dependent Cell-mediated Cytotoxic Activity. Sci Rep 2017; 7:12655. [PMID: 28978939 PMCID: PMC5627290 DOI: 10.1038/s41598-017-12883-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/15/2017] [Indexed: 12/19/2022] Open
Abstract
The development of an effective vaccine against HIV-1 has proven to be challenging. Broadly neutralizing antibodies (bNAbs), whilst exhibiting neutralization breadth and potency, are elicited only in a small subset of infected individuals and have yet to be induced by vaccination. Case-control studies of RV144 identified an inverse correlation of HIV-1 infection risk with antibodies (Abs) to the V1V2 region of gp120 with high antibody-dependent cellular cytotoxicity (ADCC) activity. The neutralizing activity of Abs was not found to contribute to this protective outcome. Using primary effector and target cells and primary virus isolates, we studied the ADCC profile of different monoclonal Abs targeting the V1V2 loop of gp120 that had low or no neutralizing activity. We compared their ADCC activity to some bNAbs targeting different regions of gp120. We found that mAbs targeting the V1V2 domain induce up to 60% NK cell mediated lysis of HIV-1 infected PBMCs in a physiologically relevant ADCC model, highlighting the interest in inducing such Abs in future HIV vaccine trials. Our data also suggest that in addition to neutralization, lysis of infected cells by Abs can effectively participate in HIV protection, as suggested by the RV144 immune correlate analysis.
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Affiliation(s)
- Luzia M Mayr
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Thomas Decoville
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France.,Vaccine Research Institute (VRI), Créteil, France
| | - Sylvie Schmidt
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Géraldine Laumond
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Jéromine Klingler
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Camille Ducloy
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France.,Vaccine Research Institute (VRI), Créteil, France
| | - Seiamak Bahram
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Susan Zolla-Pazner
- Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Christiane Moog
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France. .,Vaccine Research Institute (VRI), Créteil, France.
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27
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Plasticity and Epitope Exposure of the HIV-1 Envelope Trimer. J Virol 2017; 91:JVI.00410-17. [PMID: 28615206 DOI: 10.1128/jvi.00410-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/30/2017] [Indexed: 01/21/2023] Open
Abstract
We recently showed that mutations in the HIV-1 envelope (Env) destabilize the V3 loop, rendering neutralization-resistant viruses sensitive to V3-directed monoclonal antibodies (MAbs). Here, we investigated the propagation of this effect on other Env epitopes, with special emphasis on V2 loop exposure. Wild-type JR-FL and 19 mutant JR-FL pseudoviruses were tested for neutralization sensitivity to 21 MAbs specific for epitopes in V2, the CD4 binding site (CD4bs), and the CD4-induced (CD4i) region. Certain glycan mutants, mutations in the gp120 hydrophobic core, and mutations in residues involved in intraprotomer interactions exposed epitopes in the V2i region (which overlies the α4β7 integrin binding site) and the V3 crown, suggesting general destabilization of the distal region of the trimer apex. In contrast, other glycan mutants, mutations affecting interprotomer interactions, and mutations affecting the CD4bs exposed V3 but not V2i epitopes. These data indicate for the first time that V3 can move independently of V2, with V3 pivoting out from its "tucked" position in the trimer while apparently leaving the V2 apex intact. Notably, none of the mutations exposed V2 epitopes without also exposing V3, suggesting that movement of V2 releases V3. Most mutations increased sensitivity to CD4bs-directed MAbs without exposure of the CD4i epitope, implying these mutations facilitate the trimers' maintenance of an intermediate energy state between open and closed conformations. Taken together, these data indicate that several transient Env epitopes can be rendered more accessible to antibodies (Abs) via specific mutations, and this may facilitate the design of V1V2-targeting immunogens.IMPORTANCE Many epitopes of the HIV envelope (Env) spike are relatively inaccessible to antibodies (Abs) compared to their exposure in the open Env conformation induced by receptor binding. However, the reduced infection rate that resulted from the vaccine used in the RV144 HIV-1 vaccine trial was correlated with the elicitation of V2- and V3-directed antibodies. Previously, we identified various mechanisms responsible for destabilizing the V3 loop; here, we determined, via mutation of numerous Env residues, which of these elements maintain the V1V2 loop in an inaccessible state and which expose V1V2 and/or V3 epitopes. Notably, our data indicate that V3 can move independently of V2, but none of the mutations studied expose V2 epitopes without also exposing V3. Additionally, V1V2 can be rendered more accessible to Abs via specific mutations, facilitating the development of engineered V2 immunogens.
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28
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Torres OB, Matyas GR, Rao M, Peachman KK, Jalah R, Beck Z, Michael NL, Rice KC, Jacobson AE, Alving CR. Heroin-HIV-1 (H2) vaccine: induction of dual immunologic effects with a heroin hapten-conjugate and an HIV-1 envelope V2 peptide with liposomal lipid A as an adjuvant. NPJ Vaccines 2017; 2:13. [PMID: 29263870 PMCID: PMC5604742 DOI: 10.1038/s41541-017-0013-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 12/20/2022] Open
Abstract
A synthetic heroin analog (MorHap) and a synthetic 42 amino acid V2 loop peptide from A/E strain of HIV-1 gp120 envelope protein that was previously used in a successful phase III vaccine trial were constructed as antigens together with liposomes containing monophosphoryl lipid A as an adjuvant, to explore the feasibility of producing a dual use vaccine both for treatment of heroin addiction and prevention of HIV-1 infection among injection drug users. The V2 peptide was tethered by a palmitoyl fatty acyl tail embedded in the liposomal lipid bilayer, and the heroin analog was conjugated to tetanus toxoid as a carrier protein that was mixed with the adjuvant. Upon comparison of a linear V2 peptide with a cyclic peptide, differences were found in the secondary configurations by circular dichroism, with the tethered cyclic peptide (palm-cyclic peptide) entirely in a random coil, and the tethered linear V2 peptide (palm-linear V2 peptide) entirely in a beta-sheet. Upon immunization of mice, palm-cyclic peptide induced anti-cyclic peptide endpoint titers >106 and was considered to be a better immunogen overall than palm-linear V2 peptide for inducing antibodies to gp120 and gp70-V1V2. The antibodies also inhibited the binding of V2 peptide to the HIV-1 α4β7 integrin receptor. Antibody titers to MorHap, even with the presence of injected cyclic peptide, were very high, and resulted in inhibition of the hyper-locomotion and antinociception effects of injected heroin. From these initial experiments, we conclude that with a potent adjuvant and mostly synthetic constituents, a vaccine directed to heroin and HIV-1 (H2 vaccine) could be a feasible objective. A vaccine designed to treat heroin addiction while at the same time preventing HIV infection elicited strong immune responses in mice. Scientists from the US government led by Carl Alving from the Walter Reed Army Institute of Research in Bethesda, Maryland, created a dual vaccine formulated with three main components: a segment of a protein expressed on the surface of HIV; synthetic molecules that resemble heroin and its degradation products; and a potent adjuvant to stimulate the immune system. Mice immunized with this vaccine had high antibody titers against the HIV surface protein as well as heroin and its derivatives. These mice also showed dulled responses to injected heroin. The findings suggest this vaccine strategy could help fight heroin abuse and the high risk of HIV infection among intravenous drug users.
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Affiliation(s)
- Oscar B Torres
- US Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, 20817 MD USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Gary R Matyas
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Mangala Rao
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Kristina K Peachman
- US Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, 20817 MD USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Rashmi Jalah
- US Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, 20817 MD USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Zoltan Beck
- US Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, 20817 MD USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Nelson L Michael
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
| | - Kenner C Rice
- Department of Health and Human Services, Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, National Institutes of Health, 9800 Medical Drive, Bethesda, 20892 MD USA.,National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 9800 Medical Drive, Bethesda, 20892 MD USA
| | - Arthur E Jacobson
- Department of Health and Human Services, Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, National Institutes of Health, 9800 Medical Drive, Bethesda, 20892 MD USA.,National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 9800 Medical Drive, Bethesda, 20892 MD USA
| | - Carl R Alving
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, 20910 MD USA
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29
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Balasubramanian P, Kumar R, Williams C, Itri V, Wang S, Lu S, Hessell AJ, Haigwood NL, Sinangil F, Higgins KW, Liu L, Li L, Nyambi P, Gorny MK, Totrov M, Nadas A, Kong XP, Zolla-Pazner S, Hioe CE. Differential induction of anti-V3 crown antibodies with cradle- and ladle-binding modes in response to HIV-1 envelope vaccination. Vaccine 2017; 35:1464-1473. [PMID: 28185743 DOI: 10.1016/j.vaccine.2016.11.107] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/22/2016] [Accepted: 11/09/2016] [Indexed: 11/25/2022]
Abstract
The V3 loop in the HIV envelope gp120 is one of the immunogenic sites targeted by Abs. The V3 crown in particular has conserved structural elements recognized by cross-reactive neutralizing Abs, indicating its potential contribution in protection against HIV. Crystallographic analyses of anti-V3 crown mAbs in complex with the V3 peptides have revealed that these mAbs recognize the conserved sites on the V3 crown via two distinct strategies: a cradle-binding mode (V3C) and a ladle-binding (V3L) mode. However, almost all of the anti-V3 crown mAbs studied in the past were isolated from chronically HIV-infected individuals. The extents to which the two types of anti-V3 crown Abs are generated by vaccination are unknown. This study analyzed the prevalence of V3C-type and V3L-type Ab responses in HIV-infected individuals and in HIV envelope-immunized humans and animals using peptide mimotopes that distinguish the two Ab types. The results show that both V3L-type and V3C-type Abs were generated by the vast majority of chronically HIV-infected humans, although the V3L-type were more prevalent. In contrast, only one of the two V3 Ab types was elicited in vaccinated humans or animal models, irrespective of HIV-1 envelope clades, envelope constructs (oligomeric or monomeric), and protocols (DNA plus protein or protein alone) used for vaccinations. The V3C-type Abs were produced by vaccinated humans, macaques, and rabbits, whereas the V3L-type Abs were made by mice. The V3C-type and V3L-type Abs generated by the vaccinations were able to mediate virus neutralization. These data indicate the restricted repertoires and the species-specific differences in the functional V3-specific Ab responses induced by the HIV envelope vaccines. The study implies the need for improving immunogen designs and vaccination strategies to broaden the diversity of Abs in order to target the different conserved epitopes in the V3 loop and, by extension, in the entire HIV envelope.
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Affiliation(s)
- Preetha Balasubramanian
- The Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY 10016, USA; Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rajnish Kumar
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; James J. Peters VA Medical Center, Bronx, NY 10468, USA
| | - Constance Williams
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Vincenza Itri
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Shixia Wang
- University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Shan Lu
- University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ann J Hessell
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Nancy L Haigwood
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA; Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Faruk Sinangil
- Global Solutions for Infectious Diseases, South San Francisco, CA, USA
| | - Keith W Higgins
- Global Solutions for Infectious Diseases, South San Francisco, CA, USA
| | - Lily Liu
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Liuzhe Li
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Phillipe Nyambi
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Miroslaw K Gorny
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Maxim Totrov
- Molsoft LLC, 3366 N Torrey Pines Ct., La Jolla, CA 92037, USA
| | - Arthur Nadas
- Department of Environment Medicine, NYU School of Medicine, New York, NY 10016, USA
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Susan Zolla-Pazner
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Catarina E Hioe
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; James J. Peters VA Medical Center, Bronx, NY 10468, USA.
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Rationally Designed Immunogens Targeting HIV-1 gp120 V1V2 Induce Distinct Conformation-Specific Antibody Responses in Rabbits. J Virol 2016; 90:11007-11019. [PMID: 27707920 DOI: 10.1128/jvi.01409-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/23/2016] [Indexed: 11/20/2022] Open
Abstract
The V1V2 region of HIV-1 gp120 harbors a major vulnerable site targeted by a group of broadly neutralizing monoclonal antibodies (MAbs) such as PG9 through strand-strand recognition. However, this epitope region is structurally polymorphic as it can also form a helical conformation recognized by RV144 vaccine-induced MAb CH58. This structural polymorphism is a potential mechanism for masking the V1V2 vulnerable site. Designing immunogens that can induce conformation-specific antibody (Ab) responses may lead to vaccines targeting this vulnerable site. We designed a panel of immunogens engrafting the V1V2 domain into trimeric and pentameric scaffolds in structurally constrained conformations. We also fused V1V2 to an Fc fragment to mimic the unconstrained V1V2 conformation. We tested these V1V2-scaffold proteins for immunogenicity in rabbits and assessed the responses by enzyme-linked immunosorbent assay (ELISA) and competition assays. Our V1V2 immunogens induced distinct conformation-specific Ab responses. Abs induced by structurally unconstrained immunogens reacted preferentially with unconstrained V1V2 antigens, suggesting recognition of the helical configuration, while Abs induced by the structurally constrained immunogens reacted preferentially with constrained V1V2 antigens, suggesting recognition of the β-strand conformation. The Ab responses induced by the structurally constrained immunogens were more broadly reactive and had higher titers than those induced by the structurally unconstrained immunogens. Our results demonstrate that immunogens presenting the different structural conformations of the gp120 V1V2 vulnerable site can be designed and that these immunogens induce distinct Ab responses with epitope conformation specificity. Therefore, these structurally constrained V1V2 immunogens are vaccine prototypes targeting the V1V2 domain of the HIV-1 envelope. IMPORTANCE The correlates analysis of the RV144 HIV-1 vaccine trial suggested that the presence of antibodies to the V1V2 region of HIV-1 gp120 was responsible for the modest protection observed in the trial. In addition, V1V2 harbors one of the key vulnerable sites of HIV-1 Env recognized by a family of broadly neutralizing MAbs such as PG9. Thus, V1V2 is a key target for vaccine development. However, this vulnerable site is structurally polymorphic, and designing immunogens that present different conformations is crucial for targeting this site. We show here that such immunogens can be designed and that they induced conformation-specific antibody responses in rabbits. Our immunogens are therefore prototypes of vaccine candidates targeting the V1V2 region of HIV-1 Env.
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Rationally Designed Vaccines Targeting the V2 Region of HIV-1 gp120 Induce a Focused, Cross-Clade-Reactive, Biologically Functional Antibody Response. J Virol 2016; 90:10993-11006. [PMID: 27630234 DOI: 10.1128/jvi.01403-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/04/2016] [Indexed: 01/27/2023] Open
Abstract
Strong antibody (Ab) responses against V1V2 epitopes of the human immunodeficiency virus type 1 (HIV-1) gp120 envelope (Env) correlated with reduced infection rates in studies of HIV, simian-human immunodeficiency virus (SHIV), and simian immunodeficiency virus (SIV). In order to focus the Ab response on V1V2, we used six V1V2 sequences and nine scaffold proteins to construct immunogens which were tested using various immunization regimens for their ability to induce cross-reactive and biologically active V2 Abs in rabbits. A prime/boost immunization strategy was employed using gp120 DNA and various V1V2-scaffold proteins. The rabbit polyclonal Ab responses (i) were successfully focused on the V1V2 region, with weak or only transient responses to other Env epitopes, (ii) displayed broad cross-reactive binding activity with gp120s and the V1V2 regions of diverse strains from clades B, C, and E, (iii) included V2 Abs with specificities similar to those found in HIV-infected individuals, and (iv) remained detectable ≥1 year after the last boosting dose. Importantly, sera from rabbits receiving V1V2-scaffold immunogens displayed Ab-dependent cellular phagocytosis whereas sera from rabbits receiving only gp120 did not. The results represent the first fully successful example of reverse vaccinology in the HIV vaccine field with rationally designed epitope scaffold immunogens inducing Abs that recapitulate the epitope specificity and biologic activity of the human monoclonal Abs from which the immunogens were designed. Moreover, this is the first immunogenicity study using epitope-targeting, rationally designed vaccine constructs that induced an Fc-mediated activity associated with protection from infection with HIV, SIV, and SHIV. IMPORTANCE Novel immunogens were designed to focus the antibody response of rabbits on the V1V2 epitopes of HIV-1 gp120 since such antibodies were associated with reduced infection rates of HIV, SIV, and SHIV. The vaccine-induced antibodies were broadly cross-reactive with the V1V2 regions of HIV subtypes B, C and E and, importantly, facilitated Fc-mediated phagocytosis, an activity not induced upon immunization of rabbits with gp120. This is the first immunogenicity study of vaccine constructs that focuses the antibody response on V1V2 and induces V2-specific antibodies with the ability to mediate phagocytosis, an activity that has been associated with protection from infection with HIV, SIV, and SHIV.
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HIV Envelope gp120 Alters T Cell Receptor Mobilization in the Immunological Synapse of Uninfected CD4 T Cells and Augments T Cell Activation. J Virol 2016; 90:10513-10526. [PMID: 27630246 DOI: 10.1128/jvi.01532-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/07/2016] [Indexed: 01/21/2023] Open
Abstract
HIV is transmitted most efficiently from cell to cell, and productive infection occurs mainly in activated CD4 T cells. It is postulated that HIV exploits immunological synapses formed between CD4 T cells and antigen-presenting cells to facilitate the targeting and infection of activated CD4 T cells. This study sought to evaluate how the presence of the HIV envelope (Env) in the CD4 T cell immunological synapse affects synapse formation and intracellular signaling to impact the downstream T cell activation events. CD4 T cells were applied to supported lipid bilayers that were reconstituted with HIV Env gp120, anti-T cell receptor (anti-TCR) monoclonal antibody, and ICAM-1 to represent the surface of HIV Env-bearing antigen-presenting cells. The results showed that the HIV Env did not disrupt immunological synapse formation. Instead, the HIV Env accumulated with TCR at the center of the synapse, altered the kinetics of TCR recruitment to the synapse and affected synapse morphology over time. The HIV Env also prolonged Lck phosphorylation at the synapse and enhanced TCR-induced CD69 upregulation, interleukin-2 secretion, and proliferation to promote virus infection. These results suggest that HIV uses the immunological synapse as a conduit not only for selective virus transmission to activated CD4 T cells but also for boosting the T cell activation state, thereby increasing its likelihood of undergoing productive replication in targeted CD4 T cells. IMPORTANCE There are about two million new HIV infections every year. A better understanding of how HIV is transmitted to susceptible cells is critical to devise effective strategies to prevent HIV infection. Activated CD4 T cells are preferentially infected by HIV, although how this is accomplished is not fully understood. This study examined whether HIV co-opts the normal T cell activation process through the so-called immunological synapse. We found that the HIV envelope is recruited to the center of the immunological synapse together with the T cell receptor and enhances the T cell receptor-induced activation of CD4 T cells. Heightened cellular activation promotes the capacity of CD4 T cells to support productive HIV replication. This study provides evidence of the exploitation of the normal immunological synapse and T cell activation process by HIV to boost the activation state of targeted CD4 T cells and promote the infection of these cells.
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Van Regenmortel MHV. Structure-Based Reverse Vaccinology Failed in the Case of HIV Because it Disregarded Accepted Immunological Theory. Int J Mol Sci 2016; 17:E1591. [PMID: 27657055 PMCID: PMC5037856 DOI: 10.3390/ijms17091591] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/30/2016] [Accepted: 09/07/2016] [Indexed: 12/14/2022] Open
Abstract
Two types of reverse vaccinology (RV) should be distinguished: genome-based RV for bacterial vaccines and structure-based RV for viral vaccines. Structure-based RV consists in trying to generate a vaccine by first determining the crystallographic structure of a complex between a viral epitope and a neutralizing monoclonal antibody (nMab) and then reconstructing the epitope by reverse molecular engineering outside the context of the native viral protein. It is based on the unwarranted assumption that the epitope designed to fit the nMab will have acquired the immunogenic capacity to elicit a polyclonal antibody response with the same protective capacity as the nMab. After more than a decade of intensive research using this type of RV, this approach has failed to deliver an effective, preventive HIV-1 vaccine. The structure and dynamics of different types of HIV-1 epitopes and of paratopes are described. The rational design of an anti-HIV-1 vaccine is shown to be a misnomer since investigators who claim that they design a vaccine are actually only improving the antigenic binding capacity of one epitope with respect to only one paratope and not the immunogenic capacity of an epitope to elicit neutralizing antibodies. Because of the degeneracy of the immune system and the polyspecificity of antibodies, each epitope studied by the structure-based RV procedure is only one of the many epitopes that the particular nMab is able to recognize and there is no reason to assume that this nMab must have been elicited by this one epitope of known structure. Recent evidence is presented that the trimeric Env spikes of the virus possess such an enormous plasticity and intrinsic structural flexibility that it is it extremely difficult to determine which Env regions are the best candidate vaccine immunogens most likely to elicit protective antibodies.
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Affiliation(s)
- Marc H V Van Regenmortel
- UMR 7242 Biotechnologie et Signalisation Cellulaire, Université de Strasbourg-CNRS, 300, Boulevard Sébastien Brant, CS 10413, 67412 Illkirch Cedex, France.
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Moody MA, Gao F, Gurley TC, Amos JD, Kumar A, Hora B, Marshall DJ, Whitesides JF, Xia SM, Parks R, Lloyd KE, Hwang KK, Lu X, Bonsignori M, Finzi A, Vandergrift NA, Alam SM, Ferrari G, Shen X, Tomaras GD, Kamanga G, Cohen MS, Sam NE, Kapiga S, Gray ES, Tumba NL, Morris L, Zolla-Pazner S, Gorny MK, Mascola JR, Hahn BH, Shaw GM, Sodroski JG, Liao HX, Montefiori DC, Hraber PT, Korber BT, Haynes BF. Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses. Cell Host Microbe 2016; 18:354-62. [PMID: 26355218 DOI: 10.1016/j.chom.2015.08.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/14/2015] [Accepted: 08/14/2015] [Indexed: 11/19/2022]
Abstract
The third variable (V3) loop and the CD4 binding site (CD4bs) of the HIV-1 envelope are frequently targeted by neutralizing antibodies (nAbs) in infected individuals. In chronic infection, HIV-1 escape mutants repopulate the plasma, and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3 and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tier 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses.
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Affiliation(s)
- M Anthony Moody
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Feng Gao
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
| | - Thaddeus C Gurley
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Joshua D Amos
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Amit Kumar
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Bhavna Hora
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Dawn J Marshall
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - John F Whitesides
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Shi-Mao Xia
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Krissey E Lloyd
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Kwan-Ki Hwang
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Xiaozhi Lu
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Mattia Bonsignori
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM and Department of Microbiology, Infectology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada and Department of Microbiology and Immunology, McGill University, Montreal, QC H2X 1P1, Canada
| | - Nathan A Vandergrift
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA; Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Guido Ferrari
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Xiaoying Shen
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA; Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Gift Kamanga
- University of North Carolina Project, Kamuzu Central Hospital, Lilongwe, Malawi
| | - Myron S Cohen
- Departments of Medicine, Epidemiology, Microbiology, and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Noel E Sam
- Kilimanjaro Christian Medical Center, Moshi 25102, Tanzania
| | - Saidi Kapiga
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Elin S Gray
- National Institute for Communicable Diseases, Johannesburg 2131, South Africa
| | - Nancy L Tumba
- National Institute for Communicable Diseases, Johannesburg 2131, South Africa
| | - Lynn Morris
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; National Institute for Communicable Diseases, Johannesburg 2131, South Africa
| | - Susan Zolla-Pazner
- Department of Pathology, New York University School of Medicine, New York, NY 10010, USA; Veterans Affairs New York Harbor Healthcare System, New York, NY 10010, USA
| | - Miroslaw K Gorny
- Department of Pathology, New York University School of Medicine, New York, NY 10010, USA
| | - John R Mascola
- Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA
| | - Beatrice H Hahn
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - George M Shaw
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Hua-Xin Liao
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - David C Montefiori
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Peter T Hraber
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Bette T Korber
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
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Abstract
Antibodies (Abs) are a critical component of the human immune response against viral infections. In HIV-infected patients, a robust Ab response against the virus develops within months of infection; however, due to numerous strategies, the virus usually escapes the biological effects of the various Abs. Here we provide an overview of the different viral evasion mechanisms, including glycosylation, high mutation rate, and conformational masking by the envelope glycoproteins of the virus. In response to virus infection and to its evolution within a host, "conventional Abs" are generated, and these can also be induced by immunization; generally, these Abs are limited in their neutralization breadth and potency. In contrast, "exceptional Abs" require extended exposure to virus to generate the required hypermutation in the immunoglobulin variable regions, and they occur only in rare HIV-infected individuals, but they display impressive breadth and potency. In this review, we describe the major regions of the HIV envelope spike that are targeted by conventional and exceptional Abs. These include the first, second, and third variable loops (V1, V2, and V3) located at the apex of the envelope trimer, the CD4 binding site, and the membrane-proximal external region of the gp41 ectodomain. Lastly, we discuss the challenging task of HIV immunogen design and approaches for choosing which immunogens might be used to elicit protective Abs.
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Zolla-Pazner S, Cohen SS, Boyd D, Kong XP, Seaman M, Nussenzweig M, Klein F, Overbaugh J, Totrov M. Structure/Function Studies Involving the V3 Region of the HIV-1 Envelope Delineate Multiple Factors That Affect Neutralization Sensitivity. J Virol 2016; 90:636-49. [PMID: 26491157 PMCID: PMC4702699 DOI: 10.1128/jvi.01645-15] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 10/04/2015] [Indexed: 01/13/2023] Open
Abstract
UNLABELLED Antibodies (Abs) specific for the V3 loop of the HIV-1 gp120 envelope neutralize most tier 1 and many tier 2 viruses and are present in essentially all HIV-infected individuals as well as immunized humans and animals. Vaccine-induced V3 Abs are associated with reduced HIV infection rates in humans and affect the nature of transmitted viruses in infected vaccinees, despite the fact that V3 is often occluded in the envelope trimer. Here, we link structural and experimental data showing how conformational alterations of the envelope trimer render viruses exceptionally sensitive to V3 Abs. The experiments interrogated the neutralization sensitivity of pseudoviruses with single amino acid mutations in various regions of gp120 that were predicted to alter packing of the V3 loop in the Env trimer. The results indicate that the V3 loop is metastable in the envelope trimer on the virion surface, flickering between states in which V3 is either occluded or available for binding to chemokine receptors (leading to infection) and to V3 Abs (leading to virus neutralization). The spring-loaded V3 in the envelope trimer is easily released by disruption of the stability of the V3 pocket in the unliganded trimer or disruption of favorable V3/pocket interactions. Formation of the V3 pocket requires appropriate positioning of the V1V2 domain, which is, in turn, dependent on the conformation of the bridging sheet and on the stability of the V1V2 B-C strand-connecting loop. IMPORTANCE The levels of antibodies to the third variable region (V3) of the HIV envelope protein correlate with reduced HIV infection rates. Previous studies showed that V3 is often occluded, as it sits in a pocket of the envelope trimer on the surface of virions; however, the trimer is flexible, allowing occluded portions of the envelope (like V3) to flicker into an exposed position that binds antibodies. Here we provide a systematic interrogation of mechanisms by which single amino acid changes in various regions of gp120 (i) render viruses sensitive to neutralization by V3 antibodies, (ii) result in altered packing of the V3 loop, and (iii) activate an open conformation that exposes V3 to the effects of V3 Abs. Taken together, these and previous studies explain how V3 antibodies can protect against HIV-1 infection and why they should be one of the targets of vaccine-induced antibodies.
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Affiliation(s)
- Susan Zolla-Pazner
- Veterans Affairs New York Harbor Healthcare System, New York, New York, USA Departments of Pathology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - Sandra Sharpe Cohen
- Departments of Pathology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - David Boyd
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Xiang-Peng Kong
- Departments of Pathology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - Michael Seaman
- Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | | | | | - Julie Overbaugh
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Max Totrov
- Molsoft, L.L.C., San Diego, California, USA
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Peachman KK, Karasavvas N, Chenine AL, McLinden R, Rerks-Ngarm S, Jaranit K, Nitayaphan S, Pitisuttithum P, Tovanabutra S, Zolla-Pazner S, Michael NL, Kim JH, Alving CR, Rao M. Identification of New Regions in HIV-1 gp120 Variable 2 and 3 Loops that Bind to α4β7 Integrin Receptor. PLoS One 2015; 10:e0143895. [PMID: 26625359 PMCID: PMC4666614 DOI: 10.1371/journal.pone.0143895] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/10/2015] [Indexed: 11/19/2022] Open
Abstract
Background The gut mucosal homing integrin receptor α4β7 present on activated CD4+ T cells interacts with the HIV-1 gp120 second variable loop (V2). Case control analysis of the RV144 phase III vaccine trial demonstrated that plasma IgG binding antibodies specific to scaffolded proteins expressing the first and second variable regions (V1V2) of HIV envelope protein gp120 containing the α4β7 binding motif correlated inversely with risk of infection. Subsequently antibodies to the V3 region were also shown to correlate with protection. The integrin receptor α4β7 was shown to interact with the LDI/V motif on V2 loop but recent studies suggest that additional regions of V2 loop could interact with the α4β7. Thus, there may be several regions on the V2 and possibly V3 loops that may be involved in this binding. Using a cell line, that constitutively expressed α4β7 receptors but lacked CD4, we examined the contribution of V2 and V3 loops and the ability of V2 peptide-, V2 integrin-, V3-specific monoclonal antibodies (mAbs), and purified IgG from RV144 vaccinees to block the V2/V3-α4β7 interaction. Results We demonstrate that α4β7 on RPMI8866 cells bound specifically to its natural ligand mucosal addressin cell adhesion molecule-1 (MAdCAM-1) as well as to cyclic-V2 and cyclic-V3 peptides. This binding was inhibited by anti-α4β7-specific monoclonal antibody (mAb) ACT-1, mAbs specific to either V2 or V3 loops, and by purified primary virions or infectious molecular clones expressing envelopes from acute or chronic subtypes A, C, and CRF01_AE viruses. Plasma from HIV-1 infected Thai individuals as well as purified IgG from uninfected RV144 vaccinees inhibited (0–50%) the binding of V2 and V3 peptides to α4β7. Conclusion Our results indicate that in addition to the tripeptide LDI/V motif, other regions of the V2 and V3 loops of gp120 were involved in binding to α4β7 receptors and this interaction was blocked by anti-V2 peptide, anti-V2 integrin, and anti-V3 antibodies. The ability of purified IgG from some of the uninfected RV144 vaccinees to inhibit α4β7 raises the hypothesis that anti-V2 and anti-V3 antibodies may play a role in blocking the gp120-α4β7 interaction after vaccination and thus prevent HIV-1 acquisition.
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Affiliation(s)
- Kristina K. Peachman
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Nicos Karasavvas
- United States Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Agnes-Laurence Chenine
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Robert McLinden
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | | | | | - Sorachai Nitayaphan
- Royal Thai Army, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Sodsai Tovanabutra
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Susan Zolla-Pazner
- Veterans Administration New York Harbor Health Care System and NYU School of Medicine, New York, United States of America
| | - Nelson L. Michael
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Jerome H. Kim
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Carl R. Alving
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Mangala Rao
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- * E-mail:
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38
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Rationally Targeted Mutations at the V1V2 Domain of the HIV-1 Envelope to Augment Virus Neutralization by Anti-V1V2 Monoclonal Antibodies. PLoS One 2015; 10:e0141233. [PMID: 26491873 PMCID: PMC4619609 DOI: 10.1371/journal.pone.0141233] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/06/2015] [Indexed: 01/25/2023] Open
Abstract
HIV-1 envelope glycoproteins (Env) are the only viral antigens present on the virus surface and serve as the key targets for virus-neutralizing antibodies. However, HIV-1 deploys multiple strategies to shield the vulnerable sites on its Env from neutralizing antibodies. The V1V2 domain located at the apex of the HIV-1 Env spike is known to encompass highly variable loops, but V1V2 also contains immunogenic conserved elements recognized by cross-reactive antibodies. This study evaluates human monoclonal antibodies (mAbs) against V2 epitopes which overlap with the conserved integrin α4β7-binding LDV/I motif, designated as the V2i (integrin) epitopes. We postulate that the V2i Abs have weak or no neutralizing activities because the V2i epitopes are often occluded from antibody recognition. To gain insights into the mechanisms of the V2i occlusion, we evaluated three elements at the distal end of the V1V2 domain shown in the structure of V2i epitope complexed with mAb 830A to be important for antibody recognition of the V2i epitope. Amino-acid substitutions at position 179 that restore the LDV/I motif had minimal effects on virus sensitivity to neutralization by most V2i mAbs. However, a charge change at position 153 in the V1 region significantly increased sensitivity of subtype C virus ZM109 to most V2i mAbs. Separately, a disulfide bond introduced to stabilize the hypervariable region of V2 loop also enhanced virus neutralization by some V2i mAbs, but the effects varied depending on the virus. These data demonstrate that multiple elements within the V1V2 domain act independently and in a virus-dependent fashion to govern the antibody recognition and accessibility of V2i epitopes, suggesting the need for multi-pronged strategies to counter the escape and the shielding mechanisms obstructing the V2i Abs from neutralizing HIV-1.
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Functional and Structural Characterization of Human V3-Specific Monoclonal Antibody 2424 with Neutralizing Activity against HIV-1 JRFL. J Virol 2015; 89:9090-102. [PMID: 26109728 PMCID: PMC4524078 DOI: 10.1128/jvi.01280-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/06/2015] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED The V3 region of HIV-1 gp120 is important for virus-coreceptor interaction and highly immunogenic. Although most anti-V3 antibodies neutralize only the sensitive tier 1 viruses, anti-V3 antibodies effective against the more resistant viruses exist, and a better understanding of these antibodies and their epitopes would be beneficial for the development of novel vaccine immunogens against HIV. The HIV-1 isolate JRFL with its cryptic V3 is resistant to most V3-specific monoclonal antibodies (MAbs). However, the V3 MAb 2424 achieves 100% neutralization against JRFL. 2424 is encoded by IGHV3-53 and IGLV2-28 genes, a pairing rarely used by the other V3 MAbs. 2424 also has distinct binding and neutralization profiles. Studies of 2424-mediated neutralization of JRFL produced with a mannosidase inhibitor further revealed that its neutralizing activity is unaffected by the glycan composition of the virus envelope. To understand the distinct activity of 2424, we determined the crystal structure of 2424 Fab in complex with a JRFL V3 peptide and showed that the 2424 epitope is located at the tip of the V3 crown ((307)IHIGPGRAFYT(319)), dominated by interactions with His(P308), Pro(P313), and Arg(P315). The binding mode of 2424 is similar to that of the well-characterized MAb 447-52D, although 2424 is more side chain dependent. The 2424 epitope is focused on the very apex of V3, away from nearby glycans, facilitating antibody access. This feature distinguishes the 2424 epitope from the other V3 crown epitopes and indicates that the tip of V3 is a potential site to target and incorporate into HIV vaccine immunogens. IMPORTANCE HIV/AIDS vaccines are crucial for controlling the HIV epidemics that continue to afflict millions of people worldwide. However, HIV vaccine development has been hampered by significant scientific challenges, one of which is the inability of HIV vaccine candidates evaluated thus far to elicit production of potent and broadly neutralizing antibodies. The V3 loop is one of the few immunogenic targets on the virus envelope glycoprotein that can induce neutralizing antibodies, but in many viruses, parts of V3 are inaccessible for antibody recognition. This study examined a V3-specific monoclonal antibody that can completely neutralize HIV-1 JRFL, a virus isolate resistant to most V3 antibodies. Our data reveal that this antibody recognizes the most distal tip of V3, which is not as occluded as other parts of V3. Hence, the epitope of 2424 is in one of the vulnerable sites on the virus that may be exploited in designing HIV vaccine immunogens.
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40
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The V1V2 Region of HIV-1 gp120 Forms a Five-Stranded Beta Barrel. J Virol 2015; 89:8003-10. [PMID: 26018158 PMCID: PMC4505664 DOI: 10.1128/jvi.00754-15] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/16/2015] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED The region consisting of the first and second variable regions (V1V2) of gp120 plays vital roles in the functioning of the HIV-1 envelope (Env). V1V2, which harbors multiple glycans and is highly sequence diverse, is located at the Env apex and stabilizes the trimeric gp120 spike on the virion surface. It shields V3 and the coreceptor binding sites in the prefusion state and exposes them upon CD4 binding. Data from the RV144 human HIV-1 vaccine trial suggested that antibody responses targeting the V1V2 region inversely correlated with the risk of infection; thus, understanding the antigenic structure of V1V2 can contribute to vaccine design. We have determined a crystal structure of a V1V2 scaffold molecule (V1V2ZM109-1FD6) in complex with 830A, a human monoclonal antibody that recognizes a V1V2 epitope overlapping the integrin-binding motif in V2. The structure revealed that V1V2 assumes a five-stranded beta barrel structure with the region of the integrin-binding site (amino acids [aa] 179 to 181) included in a "kink" followed by an extra beta strand. The complete barrel structure naturally presents the glycans on its outer surface and packs into its core conserved hydrophobic residues, including the Ile at position 181 which was highly correlated with vaccine efficacy in RV144. The epitope of monoclonal antibody 830A is discontinuous and composed of three segments: (i) Thr175, Tyr177, Leu179, and Asp180 at the kink overlapping the integrin-binding site; (ii) Arg153 and Val154 in V1; and (iii) Ile194 at the C terminus of V2. This report thus provides the atomic details of the immunogenic "V2i epitope." IMPORTANCE Data from the RV144 phase III clinical trial suggested that the presence of antibodies to the first and second variable regions (V1V2) of gp120 was associated with the modest protection afforded by the vaccine. V1V2 is a highly variable and immunogenic region of HIV-1 surface glycoprotein gp120, and structural information about this region and its antigenic landscape will be crucial in the design of an effective HIV-1 vaccine. We have determined a crystal structure of V1V2 in complex with human MAb 830A and have shown that MAb 830A recognizes a region overlapping the α4β7 integrin-binding site. We also showed that V1V2 forms a 5-stranded beta barrel, an elegant structure allowing sequence variations in the strand-connecting loops while preserving a conserved core.
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41
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Li L, Wang XH, Williams C, Volsky B, Steczko O, Seaman MS, Luthra K, Nyambi P, Nadas A, Giudicelli V, Lefranc MP, Zolla-Pazner S, Gorny MK. A broad range of mutations in HIV-1 neutralizing human monoclonal antibodies specific for V2, V3, and the CD4 binding site. Mol Immunol 2015; 66:364-74. [PMID: 25965315 DOI: 10.1016/j.molimm.2015.04.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 04/16/2015] [Accepted: 04/20/2015] [Indexed: 12/25/2022]
Abstract
The HIV vaccine-induced neutralizing antibodies (Abs) display low rates of mutation in their variable regions. To determine the range of neutralization mediated by similar human monoclonal Abs (mAbs) but derived from unselected chronically HIV-1 infected subjects, we tested a panel of 66 mAbs specific to V3, CD4 binding site (CD4bs) and V2 regions. The mAbs were tested against 41 pseudoviruses, including 15 tier 1 and 26 tier 2, 3 viruses, showing that the neutralization potency and breadth of anti-V3 mAbs were significantly higher than those of the anti-CD4bs and anti-V2 mAbs, and only anti-V3 mAbs were able to neutralize some tier 2, 3 viruses. The percentage of mutations in the variable regions of the heavy (VH) and light (VL) chains varied broadly in a range from 2% to 18% and correlated moderately with the neutralization breadth of tier 2, 3 viruses. There was no correlation with neutralization of tier 1 viruses as some mAbs with low and high percentages of mutations neutralized the same number of viruses. The electrostatic interactions between anti-V3 mAbs and the charged V3 region may contribute to their neutralization because the isoelectric points of the VH CDR3 of 48 anti-V3 mAbs were inversely correlated with the neutralization breadth of tier 2, 3 viruses. The results demonstrate that infection-induced antibodies to CD4bs, V3 and V2 regions can mediate cross-clade neutralization despite low levels of mutations which can be achieved by HIV-1 vaccine-induced antibodies.
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Affiliation(s)
- Liuzhe Li
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Xiao-Hong Wang
- Veterans Affairs Medical Center, New York, NY 10010, USA
| | - Constance Williams
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Barbara Volsky
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Olivia Steczko
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Kalpana Luthra
- All India Institute of Medical Sciences, New Delhi, India
| | - Phillipe Nyambi
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Arthur Nadas
- Institute of Environmental Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Véronique Giudicelli
- IMGT(®), The International ImMunoGeneTics Information System(®), CNRS, Montpellier University, Montpellier, France
| | - Marie-Paule Lefranc
- IMGT(®), The International ImMunoGeneTics Information System(®), CNRS, Montpellier University, Montpellier, France
| | - Susan Zolla-Pazner
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA; Veterans Affairs Medical Center, New York, NY 10010, USA
| | - Miroslaw K Gorny
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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