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Schön A, Kwon YD, Bender MF, Freire E. Extrapolating differential scanning calorimetry data for monoclonal antibodies to low temperatures. Anal Biochem 2024; 691:115533. [PMID: 38642818 DOI: 10.1016/j.ab.2024.115533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/05/2024] [Accepted: 04/07/2024] [Indexed: 04/22/2024]
Abstract
For irreversible denaturation transitions such as those exhibited by monoclonal antibodies, differential scanning calorimetry provides the denaturation temperature, Tm, the rate of denaturation at Tm, and the activation energy at Tm. These three quantities are essential but not sufficient for an accurate extrapolation of the rate of denaturation to temperatures of 25 °C and below. We have observed that the activation energy is not constant but temperature dependent due to the existence of an activation heat capacity, Cp,a. It is shown in this paper that a model that incorporates Cp,a is able to account for previous observations like, for example, that increasing the Tm does not always improve the stability at low temperatures; that some antibodies exhibit lower stabilities at 5 °C than at 25 °C; or that low temperature stabilities do not follow the rank order derived from Tm values. Most importantly, the activation heat capacity model is able to reproduce time dependent stabilities measured by size exclusion chromatography at low temperatures.
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Affiliation(s)
- Arne Schön
- Department of Biology, Johns Hopkins University, 3400 North Charles, Baltimore, MD, 21218, USA
| | - Young Do Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Michael F Bender
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ernesto Freire
- Department of Biology, Johns Hopkins University, 3400 North Charles, Baltimore, MD, 21218, USA.
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2
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Pincus SH, Stackhouse M, Watt C, Ober K, Cole FM, Chen HC, Smith III AB, Peters T. Soluble CD4 and low molecular weight CD4-mimetic compounds sensitize cells to be killed by anti-HIV cytotoxic immunoconjugates. J Virol 2023; 97:e0115423. [PMID: 37772823 PMCID: PMC10617435 DOI: 10.1128/jvi.01154-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 08/13/2023] [Indexed: 09/30/2023] Open
Abstract
IMPORTANCE HIV infection can be effectively treated to prevent the development of AIDS, but it cannot be cured. We have attached poisons to anti-HIV antibodies to kill the infected cells that persist even after years of effective antiviral therapy. Here we show that the killing of infected cells can be markedly enhanced by the addition of soluble forms of the HIV receptor CD4 or by mimics of CD4.
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Affiliation(s)
- Seth H. Pincus
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Megan Stackhouse
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Connie Watt
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Kelli Ober
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Frances M. Cole
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Hung-Ching Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Amos B. Smith III
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tami Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
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3
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Fredsgaard M, Kaniki SEK, Antonopoulou I, Chaturvedi T, Thomsen MH. Phenolic Compounds in Salicornia spp. and Their Potential Therapeutic Effects on H1N1, HBV, HCV, and HIV: A Review. Molecules 2023; 28:5312. [PMID: 37513186 PMCID: PMC10384198 DOI: 10.3390/molecules28145312] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/07/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023] Open
Abstract
Despite public health risk mitigation measures and regulation efforts by many countries, regions, and sectors, viral outbreaks remind the world of our vulnerability to biological hazards and the importance of mitigation actions. The saltwater-tolerant plants in the Salicornia genus belonging to the Amaranthaceae family are widely recognized and researched as producers of clinically applicable phytochemicals. The plants in the Salicornia genus contain flavonoids, flavonoid glycosides, and hydroxycinnamic acids, including caffeic acid, ferulic acid, chlorogenic acid, apigenin, kaempferol, quercetin, isorhamnetin, myricetin, isoquercitrin, and myricitrin, which have all been shown to support the antiviral, virucidal, and symptom-suppressing activities. Their potential pharmacological usefulness as therapeutic medicine against viral infections has been suggested in many studies, where recent studies suggest these phenolic compounds may have pharmacological potential as therapeutic medicine against viral infections. This study reviews the antiviral effects, the mechanisms of action, and the potential as antiviral agents of the aforementioned phenolic compounds found in Salicornia spp. against an influenza A strain (H1N1), hepatitis B and C (HBV/HCV), and human immunodeficiency virus 1 (HIV-1), as no other literature has described these effects from the Salicornia genus at the time of publication. This review has the potential to have a significant societal impact by proposing the development of new antiviral nutraceuticals and pharmaceuticals derived from phenolic-rich formulations found in the edible Salicornia spp. These formulations could be utilized as a novel strategy by which to combat viral pandemics caused by H1N1, HBV, HCV, and HIV-1. The findings of this review indicate that isoquercitrin, myricetin, and myricitrin from Salicornia spp. have the potential to exhibit high efficiency in inhibiting viral infections. Myricetin exhibits inhibition of H1N1 plaque formation and reverse transcriptase, as well as integrase integration and cleavage. Isoquercitrin shows excellent neuraminidase inhibition. Myricitrin inhibits HIV-1 in infected cells. Extracts of biomass in the Salicornia genus could contribute to the development of more effective and efficient measures against viral infections and, ultimately, improve public health.
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Affiliation(s)
| | | | - Io Antonopoulou
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden
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Enhancement of CD4 Binding, Host Cell Entry, and Sensitivity to CD4bs Antibody Inhibition Conferred by a Natural but Rare Polymorphism in the HIV-1 Envelope. J Virol 2022; 96:e0185121. [PMID: 35862673 PMCID: PMC9327689 DOI: 10.1128/jvi.01851-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A rare but natural polymorphism in the HIV-1 envelope (Env) glycoprotein, lysine at position 425 was selected as a mutation conferring resistance to maraviroc (MVC) in vitro. N425K has not been identified in HIV-infected individuals failing an MVC-based treatment. This study reports that the rare K425 polymorphism in an HIV-1 subtype A Env has increased affinity for CD4, resulting in faster host cell entry kinetics and the ability to scavenge for low cell surface expression of CD4 to mediate entry. Whereas the subtype A wild-type isolate-74 Env (N425) is inhibited by soluble (s) CD4, HIV-1 with K425 A74 Env shows enhanced infection and the ability to infect CCR5+ cells when pretreated with sCD4. Upon adding K425 or N425 HIV-1 to CD4+/CCR5+ cells along with RANTES/CCL3, only K425 HIV-1 was able to infect cells when CCR5 recycled/returned to the cell surface at 12 h post-treatment. These findings suggest that upon binding to CD4, K425 Env may maintain a stable State 2 "open" conformation capable of engaging CCR5 for entry. Only K425 was significantly more sensitivity than wild-type N425 A74 to inhibition by the CD4 binding site (bs) compound, BMS-806, the CD4bs antibody, VRC01 and N6, and the single-chain CD4i antibody, SCm9. K425 A74 was also capable of activating B cells expressing the VRC01 surface immunoglobulin. In summary, despite increased replicative fitness, we propose that K425 HIV-1 may be counterselected within infected individuals if K425 HIV-1 is rapidly eliminated by CD4bs-neutralizing antibodies. IMPORTANCE Typically, a natural amino acid polymorphism is found as the wild-type sequence in the HIV-1 population if it provides a selective advantage to the virus. The natural K425 polymorphism in HIV-1 Env results in higher host cell entry efficiency and greater replicative fitness by virtue of its high binding affinity to CD4. The studies presented herein suggest that the rare K425 HIV-1, compared to the common N425 HIV-1, may be more sensitive to inhibition by CD4bs-neutralizing antibodies (i.e., antibodies that bind to the CD4 binding pocket on the HIV-1 envelope glycoprotein). If CD4bs antibodies did emerge in an infected individual, the K425 HIV-1 may be hypersensitive to inhibition, and thus this K425 virus variant may be removed from the HIV-1 swarm despite its higher replication fitness. Studies are now underway to determine whether addition of the K425 polymorphism into the Envelope-based HIV-1 vaccines could enhance protective immunity.
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Immunotherapy with Cell-Based Biological Drugs to Cure HIV-1 Infection. Cells 2021; 11:cells11010077. [PMID: 35011639 PMCID: PMC8750418 DOI: 10.3390/cells11010077] [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: 11/25/2021] [Revised: 12/21/2021] [Accepted: 12/25/2021] [Indexed: 11/17/2022] Open
Abstract
Since its discovery 35 years ago, there have been no therapeutic interventions shown to enable full HIV-1 remission. Combined antiretroviral therapy (cART) has achieved the sustained control of HIV-1 replication, however, the life-long treatment does not eradicate long-lived latently infected reservoirs and can result in multiple side effects including the development of multidrug-resistant escape mutants. Antibody-based treatments have emerged as alternative approaches for a HIV-1 cure. Here, we will review clinical advances in coreceptor-targeting antibodies, with respect to anti-CCR5 antibodies in particular, which are currently being generated to target the early stages of infection. Among the Env-specific antibodies widely accepted as relevant in cure strategies, the potential role of those targeting CD4-induced (CD4i) epitopes of the CD4-binding site (CD4bs) in eliminating HIV-1 infected cells has gained increasing interest and will be presented. Together, with approaches targeting the HIV-1 replication cycle, we will discuss the strategies aimed at boosting and modulating specific HIV-1 immune responses, highlighting the harnessing of TLR agonists for their dual role as latency reverting agents (LRAs) and immune-modulatory compounds. The synergistic combinations of different approaches have shown promising results to ultimately enable a HIV-1 cure.
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6
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Zhang S, Holmes AP, Dick A, Rashad AA, Enríquez Rodríguez L, Canziani GA, Root MJ, Chaiken IM. Altered Env conformational dynamics as a mechanism of resistance to peptide-triazole HIV-1 inactivators. Retrovirology 2021; 18:31. [PMID: 34627310 PMCID: PMC8501640 DOI: 10.1186/s12977-021-00575-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/20/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND We previously developed drug-like peptide triazoles (PTs) that target HIV-1 Envelope (Env) gp120, potently inhibit viral entry, and irreversibly inactivate virions. Here, we investigated potential mechanisms of viral escape from this promising class of HIV-1 entry inhibitors. RESULTS HIV-1 resistance to cyclic (AAR029b) and linear (KR13) PTs was obtained by dose escalation in viral passaging experiments. High-level resistance for both inhibitors developed slowly (relative to escape from gp41-targeted C-peptide inhibitor C37) by acquiring mutations in gp120 both within (Val255) and distant to (Ser143) the putative PT binding site. The similarity in the resistance profiles for AAR029b and KR13 suggests that the shared IXW pharmacophore provided the primary pressure for HIV-1 escape. In single-round infectivity studies employing recombinant virus, V255I/S143N double escape mutants reduced PT antiviral potency by 150- to 3900-fold. Curiously, the combined mutations had a much smaller impact on PT binding affinity for monomeric gp120 (four to ninefold). This binding disruption was entirely due to the V255I mutation, which generated few steric clashes with PT in molecular docking. However, this minor effect on PT affinity belied large, offsetting changes to association enthalpy and entropy. The escape mutations had negligible effect on CD4 binding and utilization during entry, but significantly altered both binding thermodynamics and inhibitory potency of the conformationally-specific, anti-CD4i antibody 17b. Moreover, the escape mutations substantially decreased gp120 shedding induced by either soluble CD4 or AAR029b. CONCLUSIONS Together, the data suggest that the escape mutations significantly modified the energetic landscape of Env's prefusogenic state, altering conformational dynamics to hinder PT-induced irreversible inactivation of Env. This work therein reveals a unique mode of virus escape for HIV-1, namely, resistance by altering the intrinsic conformational dynamics of the Env trimer.
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Affiliation(s)
- Shiyu Zhang
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Andrew P Holmes
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Alexej Dick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Adel A Rashad
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | | | - Gabriela A Canziani
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Michael J Root
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, OH, Columbus, USA.
| | - Irwin M Chaiken
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA.
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7
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Schön A, Freire E. Reversibility and irreversibility in the temperature denaturation of monoclonal antibodies. Anal Biochem 2021; 626:114240. [PMID: 33964250 DOI: 10.1016/j.ab.2021.114240] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 01/05/2023]
Abstract
There have been numerous studies of the temperature denaturation of monoclonal antibodies (mAbs) using differential scanning calorimetry (DSC). In general, mAbs are characterized by complex temperature denaturation transitions in which the various domains (CH2, CH3, Fab) give rise to different peaks in the heat capacity function. The complexity and overall irreversibility of the temperature denaturation transition is well known and has limited the number of publications with an in-depth analysis of the data. Here we report that the temperature denaturation of the CH2 domain is reversible and only becomes irreversible after denaturation of the Fab domain, which is intrinsically irreversible. For these studies we have used the HIV neutralizing monoclonal antibody 17b. To account for the experimental heat capacity function, a mixed denaturation model that combines multiple reversible and irreversible transitions has been developed. This model accounts well for the DSC data and for the pH dependence of the heat capacity function of 17b and other monoclonal antibodies for which data is available in the literature. It is expected that a more detailed analysis of the stability of monoclonal antibodies will contribute to the development of better approaches to understand and optimize the structural viability of these therapeutic macromolecules.
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Affiliation(s)
- Arne Schön
- Department of Biology, Johns Hopkins University, 3400 North Charles, Baltimore, MD, 21218, USA
| | - Ernesto Freire
- Department of Biology, Johns Hopkins University, 3400 North Charles, Baltimore, MD, 21218, USA.
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8
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Astorga-Gamaza A, Vitali M, Borrajo ML, Suárez-López R, Jaime C, Bastus N, Serra-Peinado C, Luque-Ballesteros L, Blanch-Lombarte O, Prado JG, Lorente J, Pumarola F, Pellicer M, Falcó V, Genescà M, Puntes V, Buzon MJ. Antibody cooperative adsorption onto AuNPs and its exploitation to force natural killer cells to kill HIV-infected T cells. NANO TODAY 2021; 36:101056. [PMID: 34394703 PMCID: PMC8360327 DOI: 10.1016/j.nantod.2020.101056] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
HIV represents a persistent infection which negatively alters the immune system. New tools to reinvigorate different immune cell populations to impact HIV are needed. Herein, a novel nanotool for the specific enhancement of the natural killer (NK) immune response towards HIV-infected T-cells has been developed. Bispecific Au nanoparticles (BiAb-AuNPs), dually conjugated with IgG anti-HIVgp120 and IgG anti-human CD16 antibodies, were generated by a new controlled, linker-free and cooperative conjugation method promoting the ordered distribution and segregation of antibodies in domains. The cooperatively-adsorbed antibodies fully retained the capabilities to recognize their cognate antigen and were able to significantly enhance cell-to-cell contact between HIV-expressing cells and NK cells. As a consequence, the BiAb-AuNPs triggered a potent cytotoxic response against HIV-infected cells in blood and human tonsil explants. Remarkably, the BiAb-AuNPs were able to significantly reduce latent HIV infection after viral reactivation in a primary cell model of HIV latency. This novel molecularly-targeted strategy using a bispecific nanotool to enhance the immune system represents a new approximation with potential applications beyond HIV.
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Affiliation(s)
- Antonio Astorga-Gamaza
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Michele Vitali
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Mireya L. Borrajo
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rosa Suárez-López
- Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Carlos Jaime
- Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Neus Bastus
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Carla Serra-Peinado
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laura Luque-Ballesteros
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Oscar Blanch-Lombarte
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Universitat Autònoma de Barcelona, Badalona, Spain
| | - Julia G. Prado
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Universitat Autònoma de Barcelona, Badalona, Spain
| | - Juan Lorente
- Otorhinolaryngology Department, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Felix Pumarola
- Otorhinolaryngology Department, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Marc Pellicer
- Otorhinolaryngology Department, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Vicenç Falcó
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Meritxell Genescà
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Víctor Puntes
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
- Corresponding author at: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Maria J. Buzon
- Infectious Disease Department, Hospital Universitario Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- Corresponding author. (V. Puntes), (M.J. Buzon)
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Abstract
HIV is a virus that remains a major health concern and results in an infection that has no cure even after over 30 years since its discovery. As such, HIV vaccine discovery continues to be an area of intensive research. In this review, we summarize the most recent HIV vaccine efficacy trials, clinical trials initiated within the last 3 years, and discuss prominent improvements that have been made in prophylactic HIV vaccine designs.
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Affiliation(s)
- Jeong Hyun Lee
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA; Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA, USA.
| | - Shane Crotty
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA, USA; Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA, USA; Department of Medicine, Division of Infectious Diseases and Global Public Health, University of California, San Diego (UCSD), La Jolla, CA, USA.
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10
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Ramdas P, Sahu AK, Mishra T, Bhardwaj V, Chande A. From Entry to Egress: Strategic Exploitation of the Cellular Processes by HIV-1. Front Microbiol 2020; 11:559792. [PMID: 33343516 PMCID: PMC7746852 DOI: 10.3389/fmicb.2020.559792] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 11/05/2020] [Indexed: 01/23/2023] Open
Abstract
HIV-1 employs a rich arsenal of viral factors throughout its life cycle and co-opts intracellular trafficking pathways. This exquisitely coordinated process requires precise manipulation of the host microenvironment, most often within defined subcellular compartments. The virus capitalizes on the host by modulating cell-surface proteins and cleverly exploiting nuclear import pathways for post entry events, among other key processes. Successful virus–cell interactions are indeed crucial in determining the extent of infection. By evolving defenses against host restriction factors, while simultaneously exploiting host dependency factors, the life cycle of HIV-1 presents a fascinating montage of an ongoing host–virus arms race. Herein, we provide an overview of how HIV-1 exploits native functions of the host cell and discuss recent findings that fundamentally change our understanding of the post-entry replication events.
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Affiliation(s)
- Pavitra Ramdas
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Amit Kumar Sahu
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Tarun Mishra
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Vipin Bhardwaj
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Ajit Chande
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
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11
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Tuyishime M, Garrido C, Jha S, Moeser M, Mielke D, LaBranche C, Montefiori D, Haynes BF, Joseph S, Margolis DM, Ferrari G. Improved killing of HIV-infected cells using three neutralizing and non-neutralizing antibodies. J Clin Invest 2020; 130:5157-5170. [PMID: 32584790 PMCID: PMC7524508 DOI: 10.1172/jci135557] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 06/24/2020] [Indexed: 02/06/2023] Open
Abstract
The correlation of HIV-specific antibody-dependent cellular cytotoxicity (ADCC) responses with protection from and delayed progression of HIV-1 infection provides a rationale to leverage ADCC-mediating antibodies for treatment purposes. We evaluated ADCC mediated by different combinations of 2 to 6 neutralizing and non-neutralizing anti-HIV-1 Envelope (Env) mAbs, using concentrations ≤ 1 μg/mL, to identify combinations effective at targeting latent reservoir HIV-1 viruses from 10 individuals. We found that within 2 hours, combinations of 3 mAbs mediated more than 30% killing of HIV-infected primary CD4+ T cells in the presence of autologous NK cells, with the combination of A32 (C1C2), DH511.2K3 (MPER), and PGT121 (V3) mAbs being the most effective. Increasing the incubation of target and effector cells in the presence of mAb combinations from 2 to 24 hours resulted in increased specific killing of infected cells, even with neutralization-resistant viruses. The same combination eliminated reactivated latently HIV-1-infected cells in an ex vivo quantitative viral outgrowth assay. Therefore, administration of a combination of 3 mAbs should be considered in planning in vivo studies seeking to eliminate persistently HIV-1-infected cells.
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Affiliation(s)
- Marina Tuyishime
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Shalini Jha
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Matt Moeser
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Dieter Mielke
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Celia LaBranche
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - David Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Barton F. Haynes
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Medicine and
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Sarah Joseph
- UNC HIV Cure Center and
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Microbiology and Immunology and
| | - David M. Margolis
- UNC HIV Cure Center and
- Department of Microbiology and Immunology and
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Guido Ferrari
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
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12
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Featherstone A, Aiken C. SERINC5 Inhibits HIV-1 Infectivity by Altering the Conformation of gp120 on HIV-1 Particles. J Virol 2020; 94:e00594-20. [PMID: 32796070 PMCID: PMC7527050 DOI: 10.1128/jvi.00594-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/03/2020] [Indexed: 01/25/2023] Open
Abstract
SERINC5 is a 10-transmembrane-domain cellular protein that is incorporated into budding HIV-1 particles and reduces HIV-1 infectivity by inhibiting virus-cell fusion. HIV-1 susceptibility to SERINC5 is determined by sequences in the viral Env glycoprotein gp120, and the antiviral effect of SERINC5 is counteracted by the viral accessory protein Nef. While the precise mechanism by which SERINC5 inhibits HIV-1 infectivity is unclear, previous studies have suggested that SERINC5 affects Env conformation. To define the effects of SERINC5 on Env conformation, we quantified the binding of HIV-1 particles to immobilized Env-specific monoclonal antibodies. We observed that SERINC5 reduced the binding of HIV-1 particles bearing a SERINC5-susceptible Env to antibodies that recognize the V3 loop, a soluble CD4 (sCD4)-induced epitope, and an N-linked glycan. In contrast, SERINC5 did not alter the capture of HIV-1 particles bearing the SERINC5-resistant Env protein. Moreover, the effect of SERINC5 on antibody-dependent virus capture was abrogated by Nef expression. Our results indicate that SERINC5 inhibits HIV-1 infectivity by altering the conformation of gp120 on virions and/or physical masking of specific HIV-1 Env epitopes.IMPORTANCE SERINC5 is a host cell protein that inhibits the infectivity of HIV-1 by a novel and poorly understood mechanism. Here, we provide evidence that the SERINC5 protein alters the conformation of the HIV-1 Env proteins and that this action is correlated with SERINC5's ability to inhibit HIV-1 infectivity. Defining the specific effects of SERINC5 on the HIV-1 glycoprotein conformation may be useful for designing new antiviral strategies targeting Env.
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Affiliation(s)
- Austin Featherstone
- Vanderbilt University Medical Center, Department of Pathology, Microbiology and Immunology, Nashville, Tennessee, USA
| | - Christopher Aiken
- Vanderbilt University Medical Center, Department of Pathology, Microbiology and Immunology, Nashville, Tennessee, USA
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13
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Differential Pressures of SERINC5 and IFITM3 on HIV-1 Envelope Glycoprotein over the Course of HIV-1 Infection. J Virol 2020; 94:JVI.00514-20. [PMID: 32493821 DOI: 10.1128/jvi.00514-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 05/25/2020] [Indexed: 12/23/2022] Open
Abstract
Infection of human immunodeficiency virus type 1 (HIV-1) is subject to restriction by cellular factors. Serine incorporator 5 (SERINC5) and interferon-inducible transmembrane 3 (IFITM3) proteins represent two of these restriction factors, which inhibit HIV-1 entry into target cells. Both proteins impede fusion of the viral membrane with the cellular membrane and the formation of a viral fusion pore, and both are countered by the HIV-1 envelope glycoprotein (Env). Given the immense and lasting pressure which Env endures from host adaptive immune responses, it is important to understand whether and how HIV-1 Env is able to maintain the resistance to SERINC5 and IFITM3 throughout the course of infection. We have thus examined a panel of HIV-1 Env clones that were isolated at different stages of viral infection-transmission, acute, and chronic. While HIV-1 Env clones from the transmission stage are resistant to both SERINC5 and IFITM3, as infection progresses into the acute and chronic stages, the resistance to IFITM3 but not to SERINC5 is gradually lost. We further discovered a significant correlation between the resistance of HIV-1 Env to soluble CD4 inhibition and the resistance to SERINC5 but not to IFITM3. Interestingly, the miniprotein CD4 mimetic M48U1 sensitizes HIV-1 Env to the inhibition by SERINC5 but not IFITM3. Together, these data indicate that SERINC5 and IFITM3 exert differential inhibitory pressures on HIV-1 Env over different stages of HIV-1 infection and that HIV-1 Env uses varied strategies to resist these two restriction factors.IMPORTANCE HIV-1 Env protein is exposed to the inhibition not only by humoral response, but also by host restriction factors, including serine incorporator 5 (SERINC5) and interferon-inducible transmembrane 3 (IFITM3). This study investigates how HIV-1 envelope glycoprotein (Env) manages to overcome the pressures from all these different host inhibition mechanisms over the long course of viral infection. HIV-1 Env preserves the resistance to SERINC5 but becomes sensitive to IFITM3 when infection progresses into the chronic stage. Our study also supports the possibility of using CD4 mimetic compounds to sensitize HIV-1 Env to the inhibition by SERINC5 as a potential therapeutic strategy.
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14
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Joshi VR, Newman RM, Pack ML, Power KA, Munro JB, Okawa K, Madani N, Sodroski JG, Schmidt AG, Allen TM. Gp41-targeted antibodies restore infectivity of a fusion-deficient HIV-1 envelope glycoprotein. PLoS Pathog 2020; 16:e1008577. [PMID: 32392227 PMCID: PMC7241850 DOI: 10.1371/journal.ppat.1008577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/21/2020] [Accepted: 04/24/2020] [Indexed: 02/07/2023] Open
Abstract
The HIV-1 envelope glycoprotein (Env) mediates viral entry via conformational changes associated with binding the cell surface receptor (CD4) and coreceptor (CCR5/CXCR4), resulting in subsequent fusion of the viral and cellular membranes. While the gp120 Env surface subunit has been extensively studied for its role in viral entry and evasion of the host immune response, the gp41 transmembrane glycoprotein and its role in natural infection are less well characterized. Here, we identified a primary HIV-1 Env variant that consistently supports >300% increased viral infectivity in the presence of autologous or heterologous HIV-positive plasma. However, in the absence of HIV-positive plasma, viruses with this Env exhibited reduced infectivity that was not due to decreased CD4 binding. Using Env chimeras and sequence analysis, we mapped this phenotype to a change Q563R, in the gp41 heptad repeat 1 (HR1) region. We demonstrate that Q563R reduces viral infection by disrupting formation of the gp41 six-helix bundle required for virus-cell membrane fusion. Intriguingly, antibodies that bind cluster I epitopes on gp41 overcome this inhibitory effect, restoring infectivity to wild-type levels. We further demonstrate that the Q563R change increases HIV-1 sensitivity to broadly neutralizing antibodies (bNAbs) targeting the gp41 membrane-proximal external region (MPER). In summary, we identify an HIV-1 Env variant with impaired infectivity whose Env functionality is restored through the binding of host antibodies. These data contribute to our understanding of gp41 residues involved in membrane fusion and identify a mechanism by which host factors can alleviate a viral defect.
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Affiliation(s)
- Vinita R. Joshi
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Virology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ruchi M. Newman
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Melissa L. Pack
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Karen A. Power
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - James B. Munro
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Ken Okawa
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Navid Madani
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Joseph G. Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Aaron G. Schmidt
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Todd M. Allen
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
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15
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Antibody-Dependent Cellular Cytotoxicity-Competent Antibodies against HIV-1-Infected Cells in Plasma from HIV-Infected Subjects. mBio 2019; 10:mBio.02690-19. [PMID: 31848282 PMCID: PMC6918083 DOI: 10.1128/mbio.02690-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Measuring Envelope (Env)-specific antibody (Ab)-dependent cellular cytotoxicity (ADCC)-competent Abs in HIV+ plasma is challenging because Env displays distinctive epitopes when present in a native closed trimeric conformation on infected cells or in a CD4-bound conformation on uninfected bystander cells. We developed an ADCC model which distinguishes Env-specific ADCC-competent Abs based on their capacity to eliminate infected, bystander, or Env rgp120-coated cells as a surrogate for shed gp120 on bystander cells. A panel of monoclonal Abs (MAbs), used to opsonize these target cells, showed that infected cells were preferentially recognized/eliminated by MAbs to CD4 binding site, V3 loop, and viral spike epitopes whereas bystander/coated cells were preferentially recognized/eliminated by Abs to CD4-induced (CD4i) epitopes. In HIV-positive (HIV+) plasma, Env-specific Abs recognized and supported ADCC of infected cells, though a majority were directed toward CD4i epitopes on bystander cells. For ADCC activity to be effective in HIV control, ADCC-competent Abs need to target genuinely infected cells.IMPORTANCE HIV Env-specific nonneutralizing Abs (NnAbs) able to mediate ADCC have been implicated in protection from HIV infection. However, Env-specific NnAbs have the capacity to support ADCC of both HIV-infected and HIV-uninfected bystander cells, potentially leading to misinterpretations when the assay used to measure ADCC does not distinguish between the two target cell types present in HIV cultures. Using a novel ADCC assay, which simultaneously quantifies the killing activity of Env-specific Abs on both infected and uninfected bystander cells, we observed that only a minority of Env-specific Abs in HIV+ plasma mediated ADCC of genuinely HIV-infected cells displaying Env in its native closed conformation. This assay can be used for the development of vaccine strategies aimed at eliciting Env-specific Ab responses capable of controlling HIV infection.
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16
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Ding S, Grenier MC, Tolbert WD, Vézina D, Sherburn R, Richard J, Prévost J, Chapleau JP, Gendron-Lepage G, Medjahed H, Abrams C, Sodroski J, Pazgier M, Smith AB, Finzi A. A New Family of Small-Molecule CD4-Mimetic Compounds Contacts Highly Conserved Aspartic Acid 368 of HIV-1 gp120 and Mediates Antibody-Dependent Cellular Cytotoxicity. J Virol 2019; 93:e01325-19. [PMID: 31554684 PMCID: PMC6880173 DOI: 10.1128/jvi.01325-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) trimer mediates virus entry into cells. The "closed" conformation of Env is resistant to nonneutralizing antibodies (nnAbs). These antibodies mostly recognize occluded epitopes that can be exposed upon binding of CD4 or small-molecule CD4 mimetics (CD4mc). Here, we describe a new family of small molecules that expose Env to nnAbs and sensitize infected cells to antibody-dependent cellular cytotoxicity (ADCC). These compounds have a limited capacity to inhibit virus infection directly but are able to sensitize viral particles to neutralization by otherwise nonneutralizing antibodies. Structural analysis shows that some analogs of this family of CD4mc engage the gp120 Phe43 cavity by contacting the highly conserved D368 residue, making them attractive scaffolds for drug development.IMPORTANCE HIV-1 has evolved multiple strategies to avoid humoral responses. One efficient mechanism is to keep its envelope glycoprotein (Env) in its "closed" conformation. Here, we report on a new family of small molecules that are able to "open up" Env, thus exposing vulnerable epitopes. This new family of molecules binds in the Phe43 cavity and contacts the highly conserved D368 residue. The structural and biological attributes of molecules of this family make them good candidates for drug development.
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Affiliation(s)
- Shilei Ding
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Melissa C Grenier
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - William D Tolbert
- Infectious Diseases Division, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Dani Vézina
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Rebekah Sherburn
- Infectious Diseases Division, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Jean-Philippe Chapleau
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | | | | | - Cameron Abrams
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania, 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 Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Marzena Pazgier
- Infectious Diseases Division, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
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17
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Quantifying Anti-HIV Envelope-Specific Antibodies in Plasma from HIV Infected Individuals. Viruses 2019; 11:v11060487. [PMID: 31141927 PMCID: PMC6631318 DOI: 10.3390/v11060487] [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: 03/15/2019] [Revised: 05/21/2019] [Accepted: 05/25/2019] [Indexed: 12/15/2022] Open
Abstract
Quantifying HIV Envelope (Env)-specific antibodies in HIV+ plasma is useful for interpreting antibody dependent cellular cytotoxicity assay results. HIV Env, the only viral protein expressed on the surface of infected cells, has a native trimeric closed conformation on cells infected with wild-type HIV. However, CD4+ uninfected bystander cells in HIV+ cell cultures bind gp120 shed from HIV+ cells exposing CD4-induced epitopes normally hidden in native Env. We used flow-cytometry based assays to quantify antibodies in HIV+ plasma specific for native trimeric Env or gp120/CD4 conjugates using CEM.NKr.CCR5 (CEM) cells infected with HIV (iCEM) or coated with recombinant gp120 (cCEM), as a surrogate for gp120+ HIV- bystander cells. Results from both assays were compared to those of a plate-based ELISA to monomeric gp120. The levels of Env-specific antibodies to cCEM and iCEM, measured by flow cytometry, and to gp120 by ELISA were positively correlated. More antibodies in HIV+ plasma recognized the gp120 conformation exposed on cCEM than on iCEM. Comparisons of plasma from untreated progressors, treated progressors, and elite controllers revealed that antibodies to Env epitopes were the lowest in treated progressors. Plasma from elite controllers and untreated progressors had similarly high levels of Env-specific antibodies, despite elite controllers having undetectable HIV viral loads, while untreated progressors maintained high viral loads.
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18
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Zhang D, Zou S, Hu Y, Hou J, Hu X, Ren L, Ma L, He X, Shao Y, Hong K. Characteristics of Envelope Genes in a Chinese Chronically HIV-1 Infected Patient With Broadly Neutralizing Activity. Front Microbiol 2019; 10:1096. [PMID: 31178836 PMCID: PMC6543928 DOI: 10.3389/fmicb.2019.01096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 04/30/2019] [Indexed: 12/12/2022] Open
Abstract
Exploring the characteristics of the HIV-1 envelope glycoprotein (env) gene in a natural HIV-1 infected individual, with broadly neutralizing activity, may provide insight into the generation of such broadly neutralizing antibodies and initiate the design of an appropriate immunogen. Recently, a chronically HIV-1 infected patient with broadly neutralization activity was identified and a VRC01-class neutralizing antibody DRVIA7 (A7) was isolated from the patient. In the present study, 155 full length HIV-1 env gene fragments (including 68 functionally Env clones) were amplified longitudinally from the plasma of six time points spanning over 5 years in this donor. Viral features were analyzed by comparing Env clones of different time points, as well as 165 Chinese HIV-1 subtype B env sequences from HIV Sequence Database (Chinese B_database). Shorter V1 length, less potential glycan and a lower ratio of NXT: NXS in gp160 were observed in the first five time points compared to that from the last time points, as well that from the Chinese B_database. A sequence analysis and a neutralization assay of Env-pseudoviruses showed that the increasing diversity of env sequences in the patient was consistent with the appearance and maturation of A7 lineage antibodies. The potent neutralization activity and viruses that escaped from the neutralization of the concurrent autologous plasma, are consistent with higher residue variations at the antibody recognition sites. Almost all viruses from the plasmas were neutralization-resistant to VRC01 and A7 lineage antibodies. For a chronically HIV-1 infected individual over 10 years, we found that greater viral diversity, short V1 sequences and less potential N-linked glycosylation (PNGS) in V1, might be associated with the development of broadly neutralizing antibody responses.
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Affiliation(s)
- Dai Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China.,The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou, China
| | - Sen Zou
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Yuanyuan Hu
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Jiali Hou
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Xintao Hu
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Li Ren
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Liying Ma
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Xiang He
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Yiming Shao
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
| | - Kunxue Hong
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China
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19
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Anand SP, Prévost J, Baril S, Richard J, Medjahed H, Chapleau JP, Tolbert WD, Kirk S, Smith AB, Wines BD, Kent SJ, Hogarth PM, Parsons MS, Pazgier M, Finzi A. Two Families of Env Antibodies Efficiently Engage Fc-Gamma Receptors and Eliminate HIV-1-Infected Cells. J Virol 2019; 93:e01823-18. [PMID: 30429344 PMCID: PMC6340017 DOI: 10.1128/jvi.01823-18] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 11/07/2018] [Indexed: 12/17/2022] Open
Abstract
HIV-1 conceals epitopes of its envelope glycoproteins (Env) recognized by antibody (Ab)-dependent cellular cytotoxicity (ADCC)-mediating antibodies. These Abs, including anti-coreceptor binding site (CoRBS) and anti-cluster A antibodies, preferentially recognize Env in its "open" conformation. The binding of anti-CoRBS Abs has been shown to induce conformational changes that further open Env, allowing interaction of anti-cluster A antibodies. We explored the possibility that CoRBS Abs synergize with anti-cluster A Abs to engage Fc-gamma receptors to mediate ADCC. We found that binding of anti-CoRBS and anti-cluster A Abs to the same gp120 is required for interaction with soluble dimeric FcγRIIIa in enzyme-linked immunosorbent assays (ELISAs). We also found that Fc regions of both Abs are required to optimally engage FcγRIIIa and mediate robust ADCC. Taken together, our results indicate that these two families of Abs act together in a sequential and synergistic fashion to promote FcγRIIIa engagement and ADCC.IMPORTANCE The "open" CD4-bound conformation of HIV-1 envelope glycoproteins is the primary target of antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies present in HIV-positive (HIV+) sera, such as anti-coreceptor binding site and anti-cluster A antibodies. Here we report that the binding of these two families of antibodies is required to engage FcγRIIIa and mediate ADCC.
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Affiliation(s)
- Sai Priya Anand
- Centre de Recherche du CHUM, Montreal, QC, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - Sophie Baril
- Centre de Recherche du CHUM, Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | | | - Jean-Philippe Chapleau
- Centre de Recherche du CHUM, Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - William D Tolbert
- Infectious Diseases Division, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Sharon Kirk
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bruce D Wines
- Immune Therapies Group Burnet Institute, Melbourne, Victoria, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Victoria, Australia
| | - Stephen J Kent
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - P Mark Hogarth
- Immune Therapies Group Burnet Institute, Melbourne, Victoria, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Victoria, Australia
| | - Matthew S Parsons
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Marzena Pazgier
- Infectious Diseases Division, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
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20
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Smith SA, Burton SL, Kilembe W, Lakhi S, Karita E, Price M, Allen S, Derdeyn CA. VH1-69 Utilizing Antibodies Are Capable of Mediating Non-neutralizing Fc-Mediated Effector Functions Against the Transmitted/Founder gp120. Front Immunol 2019; 9:3163. [PMID: 30697215 PMCID: PMC6341001 DOI: 10.3389/fimmu.2018.03163] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/21/2018] [Indexed: 01/05/2023] Open
Abstract
Multiple antibody effector functions arise in HIV-1 infection that could be harnessed to protect against infection or clear the persistent reservoir. Here, we have investigated the genetic and functional memory B cell and antibody landscape present during early infection in six individuals infected with either subtype A, C, or an A/C recombinant HIV-1. These individuals demonstrated varying levels of plasma autologous neutralization (nAb) against the transmitted/founder envelope (T/F Env) pseudovirus and non-neutralizing Fc-mediated effector function (nnFc) antibody-dependent cell-mediated cytotoxicity (ADCC) against the T/F Env gp120 protein at ~7 months after infection. Genetic analysis of the immunoglobulin heavy (VH) and light (VL) chain variable domain gene segments from 352 autologous T/F Env gp120-specific single B cells recovered at this same 7-month time-point revealed an over-representation of the VH1-69 germline in five of six individuals. A defining feature of the VH1-69 utilizing gp120-specific antibodies was their significantly more hydrophobic complementarity-determining region-2 (CDRH2) regions compared to other VH CDRH2 sequences from each individual. While none of the VH1-69 antibodies possessed strong neutralizing activity against virions pseudotyped with the autologous T/F Env, almost a third were capable of mediating high ADCC activity, as assayed by intracellular granzyme B activity in CEM.NKr.CCR5 target cells coated with autologous T/F Env gp120. High ADCC mediating VH1-69 antibodies exhibited shorter complementarity-determining region-3 (CDRH3) lengths and a more neutral isoelectric point than antibodies lacking this function. In the individual that developed the highest autologous ADCC responses, the high granzyme B producing antibodies bound to surface expressed envelope in the absence of CD4 and were not enhanced by the addition of soluble CD4. Overall, VH1-69 utilizing antibodies are commonly induced against gp120 in diverse HIV-1 infections and a subset of these antibodies can mediate ADCC functions, serving as a bridge between the innate and adaptive immune response to HIV-1.
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Affiliation(s)
- S Abigail Smith
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.,Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Samantha L Burton
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.,Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | | | - Shabir Lakhi
- Zambia Emory HIV Research Project, Lusaka, Zambia
| | | | - Matt Price
- International AIDS Vaccine Initiative, New York, NY, United States.,Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States
| | - Susan Allen
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Cynthia A Derdeyn
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.,Emory Vaccine Center, Emory University, Atlanta, GA, United States.,Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
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21
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Yang E, Gardner MR, Zhou AS, Farzan M, Arvin AM, Oliver SL. HIV-1 inhibitory properties of eCD4-Igmim2 determined using an Env-mediated membrane fusion assay. PLoS One 2018; 13:e0206365. [PMID: 30359435 PMCID: PMC6201953 DOI: 10.1371/journal.pone.0206365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 10/11/2018] [Indexed: 11/19/2022] Open
Abstract
Human Immunodeficiency Virus-1 (HIV-1) entry is dependent on the envelope glycoprotein (Env) that is present on the virion and facilitates fusion between the envelope and the cellular membrane. The protein consists of two subunits, gp120 and gp41, with the former required for binding the CD4 receptor and either the CXCR4 or CCR5 coreceptor, and the latter for mediating fusion. The requirement of fusion for infection has made Env an attractive target for HIV therapy development and led to the FDA approval of enfuvirtide, a fusion inhibitor. Continued development of entry inhibitors is warranted because enfuvirtide resistant HIV-1 strains have emerged. In this study, a novel HIV-1 fusion assay was validated using neutralizing antibodies and then used to investigate the mechanism of action of eCD4-Igmim2, an HIV-1 inhibitor proposed to cooperatively bind the CD4 binding site and the sulfotyrosine-binding pocket of gp120. Greater reduction in fusion levels was observed with eCD4-Igmim2 in the fusion assay than all of the gp120 antibodies evaluated. Lab adapted isolates, HIV-1HXB2 and HIV-1YU2, were sensitive to eCD4-Igmim2 in the fusion assay, while primary isolates, HIV-1BG505 and HIV-1ZM651 were resistant. These results correlated with greater IC50 values for primary isolates compared to the lab adapted isolates observed in a virus neutralization assay. Analysis of gp120 models identified differences in the V1 and V2 domains that are associated with eCD4-Igmim2 sensitivity. This study highlights the use of a fusion assay to identify key areas for improving the potency of eCD4-Igmim2.
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Affiliation(s)
- Edward Yang
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
| | - Matthew R. Gardner
- Department of Infectious Diseases, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Amber S. Zhou
- Department of Infectious Diseases, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Michael Farzan
- Department of Infectious Diseases, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Ann M. Arvin
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Stefan L. Oliver
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, United States of America
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Alrubayyi A, Schuetz A, Lal KG, Jongrakthaitae S, Paolino KM, Ake JA, Robb ML, de Souza MS, Michael NL, Paquin-Proulx D, Eller MA. A flow cytometry based assay that simultaneously measures cytotoxicity and monocyte mediated antibody dependent effector activity. J Immunol Methods 2018; 462:74-82. [PMID: 30148978 DOI: 10.1016/j.jim.2018.08.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/23/2018] [Accepted: 08/23/2018] [Indexed: 12/14/2022]
Abstract
Antibody effector functions such as antibody dependent cellular cytotoxicity (ADCC) and antibody dependent cellular phagocytosis (ADCP) are considered important immunologic parameters following results from the RV144 clinical trial where a reduced risk of infection was associated with non-neutralizing antibody against the V1/V2 region of HIV envelope. The rapid and fluorometric ADCC (RFADCC) assay has been widely used to measure ADCC, however, the mechanism behind the activity measured remains unclear. Here, we demonstrate that monocytes acquire the PKH26 dye used in the RFADCC assay and that the commonly used RFADCC readout correlates with phagocytosis. The RFADCC assay was combined with an amine reactive dye staining to confirm target cell killing. Interestingly, the majority of RFADCC and amine indices were mutually exclusive. In fact, the amine reactive assay results correlated with results from another assays that directly measure NK cell antibody effector functions not associated with phagocytosis. Together, this combined assay offers the opportunity to discriminate monocytes and NK cell antibody effector functions simultaneously.
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Affiliation(s)
- Aljawharah Alrubayyi
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Alexandra Schuetz
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA; Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Kerri G Lal
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Surat Jongrakthaitae
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Kristopher M Paolino
- Clinical Trials Center, Translational Medicine Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Julie A Ake
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Merlin L Robb
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Mark S de Souza
- SEARCH, Thai Red Cross AIDS Research Center, Bangkok, Thailand
| | - Nelson L Michael
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Dominic Paquin-Proulx
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
| | - Michael A Eller
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
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23
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Sun L, Ishihara M, Middleton DR, Tiemeyer M, Avci FY. Metabolic labeling of HIV-1 envelope glycoprotein gp120 to elucidate the effect of gp120 glycosylation on antigen uptake. J Biol Chem 2018; 293:15178-15194. [PMID: 30115684 DOI: 10.1074/jbc.ra118.004798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/12/2018] [Indexed: 12/21/2022] Open
Abstract
The glycan shield on the envelope glycoprotein gp120 of HIV-1 has drawn immense attention as a vulnerable site for broadly neutralizing antibodies and for its significant impact on host adaptive immune response to HIV-1. Glycosylation sites and glycan composition/structure at each site on gp120 along with the interactions of gp120 glycan shield with broadly neutralizing antibodies have been extensively studied. However, a method for directly and selectively tracking gp120 glycans has been lacking. Here, we integrate metabolic labeling and click chemistry technology with recombinant gp120 expression to demonstrate that gp120 glycans could be specifically labeled and directly detected. Selective labeling of gp120 by N-azidoacetylmannosamine (ManNAz) and N-azidoacetylgalactosamine (GalNAz) incorporation into the gp120 glycan shield was characterized by MS of tryptic glycopeptides. By using metabolically labeled gp120, we investigated the impact of gp120 glycosylation on its interaction with host cells and demonstrated that oligomannose enrichment and sialic acid deficiency drastically enhanced gp120 uptake by bone marrow-derived dendritic cells. Collectively, our data reveal an effective labeling and detection method for gp120, serving as a tool for functional characterization of the gp120 glycans and potentially other glycosylated proteins.
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Affiliation(s)
- Lina Sun
- From the Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and
| | - Mayumi Ishihara
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Dustin R Middleton
- From the Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and
| | - Michael Tiemeyer
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Fikri Y Avci
- From the Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and .,Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
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24
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Similar Epitope Specificities of IgG and IgA Antibodies Elicited by Ad26 Vector Prime, Env Protein Boost Immunizations in Rhesus Monkeys. J Virol 2018; 92:JVI.00537-18. [PMID: 29793950 PMCID: PMC6052297 DOI: 10.1128/jvi.00537-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/15/2018] [Indexed: 11/20/2022] Open
Abstract
Vaccine-elicited immunoglobulin G (IgG) has been shown to be important for protection against simian-human immunodeficiency virus (SHIV) infection in rhesus monkeys. However, it remains unclear whether vaccine-elicited IgA responses are beneficial or detrimental for protection. In this study, we evaluated the kinetics, magnitude, breadth, and linear epitope specificities of vaccine-elicited IgG and IgA responses in serum and mucosal secretions following intramuscular immunization with adenovirus 26 (Ad26) prime, Env protein boost vaccination regimens. The systemic and mucosal antibody responses exhibited kinetics similar to those of the serum antibody responses but lower titers than the serum antibody responses. Moreover, the IgG and IgA responses were correlated, both in terms of the magnitude of the responses and in terms of the antibody specificities against linear human immunodeficiency virus type 1 (HIV-1) Env, Gag, and Pol epitopes. These data suggest that IgG and IgA responses are highly coordinated in both peripheral blood and mucosal compartments following Ad26/Env vaccination in rhesus monkeys.IMPORTANCE Vaccine-elicited IgG responses are important for protection against simian-human immunodeficiency virus (SHIV) infection in nonhuman primates. However, much less is known about the role and function of IgA, despite it being the predominant antibody in mucosal sites. There is debate as to whether HIV-1-specific IgA responses are beneficial or detrimental, since serum anti-Env IgA titers were shown to be inversely correlated with protection in the RV144 clinical trial. We thus assessed vaccine-elicited IgG and IgA antibody responses in peripheral blood and mucosal secretions following vaccination with the Ad26/Env vaccine.
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25
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Schiffner T, Pallesen J, Russell RA, Dodd J, de Val N, LaBranche CC, Montefiori D, Tomaras GD, Shen X, Harris SL, Moghaddam AE, Kalyuzhniy O, Sanders RW, McCoy LE, Moore JP, Ward AB, Sattentau QJ. Structural and immunologic correlates of chemically stabilized HIV-1 envelope glycoproteins. PLoS Pathog 2018; 14:e1006986. [PMID: 29746590 PMCID: PMC5944921 DOI: 10.1371/journal.ppat.1006986] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/21/2018] [Indexed: 11/19/2022] Open
Abstract
Inducing broad spectrum neutralizing antibodies against challenging pathogens such as HIV-1 is a major vaccine design goal, but may be hindered by conformational instability within viral envelope glycoproteins (Env). Chemical cross-linking is widely used for vaccine antigen stabilization, but how this process affects structure, antigenicity and immunogenicity is poorly understood and its use remains entirely empirical. We have solved the first cryo-EM structure of a cross-linked vaccine antigen. The 4.2 Å structure of HIV-1 BG505 SOSIP soluble recombinant Env in complex with a CD4 binding site-specific broadly neutralizing antibody (bNAb) Fab fragment reveals how cross-linking affects key properties of the trimer. We observed density corresponding to highly specific glutaraldehyde (GLA) cross-links between gp120 monomers at the trimer apex and between gp120 and gp41 at the trimer interface that had strikingly little impact on overall trimer conformation, but critically enhanced trimer stability and improved Env antigenicity. Cross-links were also observed within gp120 at sites associated with the N241/N289 glycan hole that locally modified trimer antigenicity. In immunogenicity studies, the neutralizing antibody response to cross-linked trimers showed modest but significantly greater breadth against a global panel of difficult-to-neutralize Tier-2 heterologous viruses. Moreover, the specificity of autologous Tier-2 neutralization was modified away from the N241/N289 glycan hole, implying a novel specificity. Finally, we have investigated for the first time T helper cell responses to next-generation soluble trimers, and report on vaccine-relevant immunodominant responses to epitopes within BG505 that are modified by cross-linking. Elucidation of the structural correlates of a cross-linked viral glycoprotein will allow more rational use of this methodology for vaccine design, and reveals a strategy with promise for eliciting neutralizing antibodies needed for an effective HIV-1 vaccine.
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MESH Headings
- AIDS Vaccines/chemistry
- AIDS Vaccines/immunology
- Animals
- Antibodies, Neutralizing/immunology
- Antibody Specificity
- Antigen-Antibody Reactions/immunology
- Cross-Linking Reagents
- Cryoelectron Microscopy
- HIV Antibodies/immunology
- HIV Antigens/chemistry
- HIV Antigens/immunology
- HIV Antigens/ultrastructure
- HIV-1/chemistry
- HIV-1/immunology
- Host-Pathogen Interactions/immunology
- Humans
- Immunodominant Epitopes/chemistry
- Immunodominant Epitopes/immunology
- Mice
- Mice, Inbred BALB C
- Models, Molecular
- Protein Conformation
- Protein Stability
- Protein Structure, Quaternary
- Rabbits
- T-Lymphocytes, Helper-Inducer/immunology
- Vaccines, Synthetic/chemistry
- Vaccines, Synthetic/immunology
- env Gene Products, Human Immunodeficiency Virus/chemistry
- env Gene Products, Human Immunodeficiency Virus/immunology
- env Gene Products, Human Immunodeficiency Virus/ultrastructure
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Affiliation(s)
- Torben Schiffner
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
| | - Jesper Pallesen
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California, United States of America
| | - Rebecca A Russell
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
| | - Jonathan Dodd
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
| | - Natalia de Val
- Center for Molecular Microscopy (CMM), National Cancer Institute (NCI), Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Celia C LaBranche
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - David Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Georgia D Tomaras
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
- Duke Human Vaccine Institute, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, United States of America
- Departments of Immunology and Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Xiaoying Shen
- Duke Human Vaccine Institute, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Scarlett L Harris
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
| | - Amin E Moghaddam
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
| | - Oleksandr Kalyuzhniy
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, California, United States of America
- IAVI Neutralizing Antibody Center and the Collaboration for AIDS Vaccine Discovery (CAVD), The Scripps Research Institute, La Jolla, California, United States of America
| | - Rogier W Sanders
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Laura E McCoy
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - John P Moore
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, IAVI Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California, United States of America
| | - Quentin J Sattentau
- The Sir William Dunn School of Pathology, The University of Oxford, Oxford, United Kingdom
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26
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Identification of Novel Structural Determinants in MW965 Env That Regulate the Neutralization Phenotype and Conformational Masking Potential of Primary HIV-1 Isolates. J Virol 2018; 92:JVI.01779-17. [PMID: 29237828 DOI: 10.1128/jvi.01779-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/28/2017] [Indexed: 11/20/2022] Open
Abstract
The subtype C HIV-1 isolate MW965.26 is a highly neutralization-sensitive tier 1a primary isolate that is widely used in vaccine studies, but the basis for the sensitive neutralization phenotype of this isolate is not known. Substituting the MW965.26 V1/V2 domain into a neutralization-sensitive SF162 Env clone resulted in high resistance to standard anti-V3 monoclonal antibodies, demonstrating that this region possesses strong masking activity in a standard Env backbone and indicating that determinants elsewhere in MW965.26 Env are responsible for its unusual neutralization sensitivity. Key determinants for this phenotype were mapped by generating chimeric Envs between MW965.26 Env and a typical resistant Env clone, the consensus C (ConC) clone, and localized to two residues, Cys384 in the C3 domain and Asn502 in the C5 domain. Substituting the sensitizing mutations Y384C and K502N at these positions into several resistant primary Envs resulted in conversion to neutralization-sensitive phenotypes, demonstrating the generalizability of this effect. In contrast to the sensitizing effects of these substitutions on normally masked epitopes, these mutations reduced the sensitivity of VRC01-like epitopes overlapping the CD4-binding domain, while they had no effect on several other classes of broadly neutralizing epitopes, including members of several lineages of V2-dependent quaternary epitopes and representatives of N332 glycan-dependent epitopes (PGT121) and quaternary, cleavage-dependent epitopes centered at the gp41-gp120 interface on intact HIV-1 Env trimers (PGT151). These results identify novel substitutions in gp120 that regulate the expression of alternative conformations of Env and differentially affect the exposure of different classes of epitopes, thereby influencing the neutralization phenotype of primary HIV-1 isolates.IMPORTANCE A better understanding of the mechanisms that determine the wide range of neutralization sensitivity of circulating primary HIV-1 isolates would provide important information about the natural structural and conformational diversity of HIV-1 Env and how this affects the neutralization phenotype. A useful way of studying this is to determine the molecular basis for the unusually high neutralization sensitivities of the limited number of available tier 1a viruses. This study localized the neutralization sensitivity of MW965.26, an extremely sensitive subtype C-derived primary isolate, to two rare substitutions in the C3 and C5 domains and demonstrated that the sequences at these positions differentially affect the presentation of epitopes recognized by different classes of standard and conformation-dependent broadly neutralizing antibodies. These results provide novel insight into how these regions regulate the neutralization phenotype and provide tools for controlling the Env conformation that could have applications both for structural studies and in vaccine design.
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27
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Richard J, Prévost J, Alsahafi N, Ding S, Finzi A. Impact of HIV-1 Envelope Conformation on ADCC Responses. Trends Microbiol 2017; 26:253-265. [PMID: 29162391 DOI: 10.1016/j.tim.2017.10.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/17/2017] [Accepted: 10/26/2017] [Indexed: 01/30/2023]
Abstract
HIV-1 envelope glycoproteins (Env) represent the only virus-specific antigen exposed at the surface of infected cells. In its unliganded form, Env from primary viruses samples a 'closed' conformation (State 1), which is preferentially recognized by broadly neutralizing antibodies (bNAbs). CD4 engagement drives Env into an intermediate 'partially open' (State 2) and then into the 'open' CD4-bound conformation (State 3). Emerging evidence suggests a link between Env conformation and Ab-dependent cellular cytotoxicity (ADCC). HIV-1-infected cells exposing Env in the CD4-bound conformation are susceptible to ADCC mediated by CD4-induced Abs and HIV+sera. Cells exposing State 1 Env are susceptible to ADCC mediated by bNAbs. Here, we discuss how Env conformation affects ADCC responses and in vitro measurements.
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Affiliation(s)
- Jonathan Richard
- Centre de Recherche du CHUM, Montreal, QC, H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, H2X 0A9, Canada; These authors contributed equally
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC, H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, H2X 0A9, Canada; These authors contributed equally
| | - Nirmin Alsahafi
- Centre de Recherche du CHUM, Montreal, QC, H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Shilei Ding
- Centre de Recherche du CHUM, Montreal, QC, H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, H2X 0A9, Canada
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC, H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, H3A 2B4, Canada.
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28
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Guerrero-Beltrán C, Ceña-Diez R, Sepúlveda-Crespo D, De la Mata J, Gómez R, Leal M, Muñoz-Fernández MA, Jiménez JL. Carbosilane dendrons with fatty acids at the core as a new potential microbicide against HSV-2/HIV-1 co-infection. NANOSCALE 2017; 9:17263-17273. [PMID: 29090302 DOI: 10.1039/c7nr05859d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) represent the two most frequent sexually transmitted infections (STI) worldwide. Epidemiological studies suggest that HSV-2 increases the risk of HIV-1 acquisition approximately 3-fold mainly due to the clinical and immunological manifestations. In the absence of vaccines against both STI, the development of new preventive strategies has become essential for further studies. We performed the screening of six novel polyanionic carbosilane dendrons to elucidate their potential activity against HSV-2/HIV-1 co-infection and their mechanism of action. These new nanoparticles are carbosilane branched dendrons from first to third generation, with palmitic or hexanoic fatty acids as the core and capped with sulfonate groups, named G1d-STE2Hx, G2d-STE4Hx, G3d-STE8Hx, G1d-STE2Pm, G2d-STE4Pm and G3d-STE8Pm. G3d-STE8Hx and G3d-STE8Pm carbosilane branched dendrons showed high viability. These dendrons also showed a great broad-spectrum antiviral activity, as well as a suitable efficacy against HIV-1 even if the mucosal disruption occurs as a consequence of HSV-2 infection. Our results exert high inhibition against HSV-2 and HIV-1 by blocking the entry of both viruses with the median effective concentration EC50 values in the nanomolar range. Additionally, G3d-STE8Hx and G3d-STE8Pm retained their anti-HSV-2/HIV-1 activity at different pH values. G3d-STE8Hx and G3d-STE8Pm dendrons may be potential candidates as dual-acting microbicides against HSV-2/HIV-1 co-infection.
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Affiliation(s)
- C Guerrero-Beltrán
- Immunology Section, Laboratorio Inmuno-Biología Molecular, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
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29
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Abstract
BACKGROUND HIV-1 is known to adapt to the local environment in its usage of receptors, and it can become CD4 independent in the brain where the receptor is scarce. This adaptation is through amino acid variations, but the patterns of such variation are not yet well understood. Given that infection of long-lived CD4-low and CD4-negative cells in anatomical compartments such as the brain expands cell tropism in vivo and may serve as potential viral reservoirs that pose challenge for HIV eradication, understanding the evolution to CD4 independence and envelope conformation associated with infection in the absence of CD4 will not only broaden our insights into HIV pathogenesis but may guide functional cure strategies as well. METHODS We characterize, by site-directed mutagenesis, neutralization assay, and structural analysis, a pair of CD4-dependent (cl2) and CD4-independent (cl20) envelopes concurrently isolated from the cerebral spinal fluid of an SHIV-infected macaque with neurological AIDS and with minimum sequence differences. RESULTS Residues different between cl2 and cl20 are mapped to the V1V2 and surrounding regions. Mutations of these residues in cl2 increased its CD4 independence in infection, and the effects are cumulative and likely structural. CONCLUSIONS Our data suggested that the determinants of CD4 independence in vivo mapped principally to V1V2 of gp120 that can destabilize the apex of the envelope spike, with an additional change in V4 that abrogated a potential N-linked glycan to facilitate movement of the V1V2 domain and further expose the coreceptor-binding site.
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30
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Tanaka K, Kuwata T, Alam M, Kaplan G, Takahama S, Valdez KPR, Roitburd-Berman A, Gershoni JM, Matsushita S. Unique binding modes for the broad neutralizing activity of single-chain variable fragments (scFv) targeting CD4-induced epitopes. Retrovirology 2017; 14:44. [PMID: 28938888 PMCID: PMC5610415 DOI: 10.1186/s12977-017-0369-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/09/2017] [Indexed: 01/01/2023] Open
Abstract
Background The CD4-induced (CD4i) epitopes in gp120 includes the co-receptor binding site, which are formed and exposed after interaction with CD4. Monoclonal antibodies (mAbs) to the CD4i epitopes exhibit limited neutralizing activity because of restricted access to their epitopes. However, small fragment counterparts such as single-chain variable fragments (scFvs) have been reported to neutralize a broad range of viruses compared with the full-size IgG molecule. To identify the CD4i epitope site responsible for this broad neutralization we constructed three scFvs of anti-CD4i mAbs from a human immunodeficiency virus type 1 (HIV-1)-infected elite controller, and investigated the neutralization coverage and precise binding site in the CD4i epitopes. Results We constructed scFvs from the anti-CD4i mAbs, 916B2, 4E9C, and 25C4b and tested their neutralization activity against a panel of 66 viruses of multi-subtype. Coverage of neutralization by the scFvs against this panel of pseudoviruses was 89% (59/66) for 4E9C, 95% (63/66) for 25C4b and 100% (66/66) for 916B2. Analysis using a series of envelope glycoprotein mutants revealed that individual anti-CD4i mAbs showed various dependencies on the hairpin 1 (H1) and V3 base. The binding profiles of 25C4b were similar to those of 17b, and 25C4b bound the region spanning multiple domains of H1 and hairpin 2 (H2) of the bridging sheet and V3 base. For 4E9C, the V3-base dependent binding was apparent from no binding to mutants containing the ΔV3 truncation. In contrast, binding of 916B2 was dependent on the H1 region, which is composed of β2 and β3 strands, because mutants containing the H1 truncation did not show any reactivity to 916B2. Although the H1 region structure is affected by CD4 engagement, the results indicate the unique nature of the 916B2 epitope, which may be structurally conserved before and after conformational changes of gp120. Conclusions Identification of a unique structure of the H1 region that can be targeted by 916B2 may have an important implication in the development of small molecules to inhibit infection by a broad range of HIV-1 for the purpose of HIV treatment and prevention. Electronic supplementary material The online version of this article (doi:10.1186/s12977-017-0369-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kazuki Tanaka
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan
| | - Takeo Kuwata
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan
| | - Muntasir Alam
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan
| | - Gilad Kaplan
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Shokichi Takahama
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan
| | - Kristel Paola Ramirez Valdez
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan
| | - Anna Roitburd-Berman
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Jonathan M Gershoni
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Shuzo Matsushita
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
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Bernard NF, Kiani Z, Tremblay-McLean A, Kant SA, Leeks CE, Dupuy FP. Natural Killer (NK) Cell Education Differentially Influences HIV Antibody-Dependent NK Cell Activation and Antibody-Dependent Cellular Cytotoxicity. Front Immunol 2017; 8:1033. [PMID: 28883824 PMCID: PMC5574056 DOI: 10.3389/fimmu.2017.01033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/10/2017] [Indexed: 11/13/2022] Open
Abstract
Immunotherapy using broadly neutralizing antibodies (bNAbs) endowed with Fc-mediated effector functions has been shown to be critical for protecting or controlling viral replication in animal models. In human, the RV144 Thai trial was the first trial to demonstrate a significant protection against HIV infection following vaccination. Analysis of the correlates of immune protection in this trial identified an association between the presence of antibody-dependent cellular cytotoxicity (ADCC) mediated by immunoglobulin G (IgG) antibodies (Abs) to HIV envelope (Env) V1/V2 loop structures and protection from infection, provided IgA Abs with competing specificity were not present. Systems serology analyses implicated a broader range of Ab-dependent functions in protection from HIV infection, including but not limited to ADCC and Ab-dependent NK cell activation (ADNKA) for secretion of IFN-γ and CCL4 and expression of the degranulation marker CD107a. The existence of such correlations in the absence of bNAbs in the RV144 trial suggest that NK cells could be instrumental in protecting against HIV infection by limiting viral spread through Fc-mediated functions such as ADCC and the production of antiviral cytokines/chemokines. Beside the engagement of FcγRIIIa or CD16 by the Fc portion of anti-Env IgG1 and IgG3 Abs, natural killer (NK) cells are also able to directly kill infected cells and produce cytokines/chemokines in an Ab-independent manner. Responsiveness of NK cells depends on the integration of activating and inhibitory signals through NK receptors, which is determined by a process during their development known as education. NK cell education requires the engagement of inhibitory NK receptors by their human leukocyte antigen ligands to establish tolerance to self while allowing NK cells to respond to self cells altered by virus infection, transformation, stress, and to allogeneic cells. Here, we review recent findings regarding the impact of inter-individual differences in NK cell education on Ab-dependent functions such as ADCC and ADNKA, including what is known about the HIV Env epitope specificity of ADCC competent Abs and the conformation of HIV Env on target cells used for ADCC assays.
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Affiliation(s)
- Nicole F Bernard
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada.,Chronic Viral Illness Service, McGill University Health Centre, Montreal, QC, Canada.,Division of Clinical Immunology, McGill University Health Centre, Montreal, QC, Canada
| | - Zahra Kiani
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Alexandra Tremblay-McLean
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Sanket A Kant
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Christopher E Leeks
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Franck P Dupuy
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
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32
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Abstract
The bar is high to improve on current combination antiretroviral therapy (ART), now highly effective, safe, and simple. However, antibodies that bind the HIV envelope are able to uniquely target the virus as it seeks to enter new target cells, or as it is expressed from previously infected cells. Furthermore, the use of antibodies against HIV as a therapeutic may offer advantages. Antibodies can have long half-lives, and are being considered as partners for long-acting antiretrovirals for use in therapy or prevention of HIV infection. Early studies in animal models and in clinical trials suggest that such antibodies can have antiviral activity but, as with small-molecule antiretrovirals, the issues of viral escape and resistance will have to be addressed. Most promising, however, are the unique properties of anti-HIV antibodies: the potential ability to opsonize viral particles, to direct antibody-dependent cellular cytotoxicity (ADCC) against actively infected cells, and ultimately the ability to direct the clearance of HIV-infected cells by effector cells of the immune system. These distinctive activities suggest that HIV antibodies and their derivatives may play an important role in the next frontier of HIV therapeutics, the effort to develop treatments that could lead to an HIV cure.
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Affiliation(s)
- David M Margolis
- UNC HIV Cure Center, Departments of Medicine, Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Richard A Koup
- Immunology Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Guido Ferrari
- Duke Human Vaccine Institute and Department of Surgery, Duke University Medical Center, Durham, NC, USA
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33
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Abstract
In 2009, Dimitrov's group reported that the inferred germline (iGL) forms of several HIV-1 broadly neutralizing antibodies (bNAbs) did not display measurable binding to a recombinant gp140 Env protein (derived from the dual-tropic 89.6 virus), which was efficiently recognized by the mature (somatically mutated) antibodies. At that time, a small number of bNAbs were available, but in the following years, the implementation of high-throughput B-cell isolation and sequencing assays and of screening methodologies facilitated the isolation of greater numbers of bNAbs from infected subjects. Using these newest bNAbs, and a wide range of diverse recombinant Envs, we and others confirmed the observations made by Dimitrov's group. The results from these studies created a paradigm shift in our collective thinking as to why recombinant Envs are ineffective in eliciting bNAbs and has led to the "germline-targeting" immunization approach. Here we discuss this approach in detail: what has been done so far, the advantages and limitations of the current germline-targeting immunogens and of the animal models used to test them, and we conclude with a few thoughts about future directions in this area of research.
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Affiliation(s)
- Leonidas Stamatatos
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.,Department of Global Health, University of Washington, Seattle, WA, USA
| | - Marie Pancera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Andrew T McGuire
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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34
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Horwitz JA, Bar-On Y, Lu CL, Fera D, Lockhart AAK, Lorenzi JCC, Nogueira L, Golijanin J, Scheid JF, Seaman MS, Gazumyan A, Zolla-Pazner S, Nussenzweig MC. Non-neutralizing Antibodies Alter the Course of HIV-1 Infection In Vivo. Cell 2017; 170:637-648.e10. [PMID: 28757252 DOI: 10.1016/j.cell.2017.06.048] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 06/21/2017] [Accepted: 06/29/2017] [Indexed: 11/26/2022]
Abstract
Non-neutralizing antibodies (nnAbs) to HIV-1 show little measurable activity in prevention or therapy in animal models yet were the only correlate of protection in the RV144 vaccine trial. To investigate the role of nnAbs on HIV-1 infection in vivo, we devised a replication-competent HIV-1 reporter virus that expresses a heterologous HA-tag on the surface of infected cells and virions. Anti-HA antibodies bind to, but do not neutralize, the reporter virus in vitro. However, anti-HA protects against infection in humanized mice and strongly selects for nnAb-resistant viruses in an entirely Fc-dependent manner. Similar results were also obtained with tier 2 HIV-1 viruses using a human anti-gp41 nnAb, 246D. While nnAbs are demonstrably less effective than broadly neutralizing antibodies (bNAbs) against HIV-1 in vitro and in vivo, the data show that nnAbs can protect against and alter the course of HIV-1 infection in vivo. PAPERCLIP.
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Affiliation(s)
- Joshua A Horwitz
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Laboratory of Structural Cell Biology, Harvard Medical School, 250 Longwood Avenue, Boston, MA 02115, USA; Whelan Laboratory, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Yotam Bar-On
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Ching-Lan Lu
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Daniela Fera
- Laboratory of Molecular Medicine, Boston Children's Hospital, Harvard Medical School, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Ainsley A K Lockhart
- Laboratory of Mucosal Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Julio C C Lorenzi
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Lilian Nogueira
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Jovana Golijanin
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Johannes F Scheid
- Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center/Harvard Medical School, 3 Blackfan Circle, Boston, MA 02115, USA
| | - Anna Gazumyan
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, 1230 York Ave, New York, NY 10065, USA
| | - Susan Zolla-Pazner
- Zolla-Pazner Laboratory, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, 1230 York Ave, New York, NY 10065, USA.
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35
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Lack of ADCC Breadth of Human Nonneutralizing Anti-HIV-1 Antibodies. J Virol 2017; 91:JVI.02440-16. [PMID: 28122982 DOI: 10.1128/jvi.02440-16] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 01/19/2017] [Indexed: 01/23/2023] Open
Abstract
Anti-human immunodeficiency virus type 1 (HIV-1) nonneutralizing antibodies (nnAbs) capable of antibody-dependent cellular cytotoxicity (ADCC) have been identified as a protective immune correlate in the RV144 vaccine efficacy trial. Broadly neutralizing antibodies (bNAbs) also mediate ADCC in cell culture and rely on their Fc region for optimal efficacy in animal models. Here, we selected 9 monoclonal nnAbs and 5 potent bNAbs targeting various epitopes and conformations of the gp120/41 complex and analyzed the potency of the two types of antibodies to bind and eliminate HIV-1-infected cells in culture. Regardless of their neutralizing activity, most of the selected antibodies recognized and killed cells infected with two laboratory-adapted HIV-1 strains. Some nnAbs also bound bystander cells that may have captured viral proteins. However, in contrast to the bNAbs, the nnAbs bound poorly to reactivated infected cells from 8 HIV-positive individuals and did not mediate effective ADCC against these cells. The nnAbs also inefficiently recognize cells infected with 8 different transmitted-founder (T/F) isolates. The addition of a synthetic CD4 mimetic enhanced the binding and killing efficacy of some of the nnAbs in an epitope-dependent manner without reaching the levels achieved by the most potent bNAbs. Overall, our data reveal important qualitative and quantitative differences between nnAbs and bNAbs in their ADCC capacity and strongly suggest that the breadth of recognition of HIV-1 by nnAbs is narrow.IMPORTANCE Most of the anti-HIV antibodies generated by infected individuals do not display potent neutralizing activities. These nonneutralizing antibodies (nnAbs) with antibody-dependent cellular cytotoxicity (ADCC) have been identified as a protective immune correlate in the RV144 vaccine efficacy trial. However, in primate models, the nnAbs do not protect against simian-human immunodeficiency virus (SHIV) acquisition. Thus, the role of nnAbs with ADCC activity in protection from infection remains debatable. In contrast, broadly neutralizing antibodies (bNAbs) neutralize a large array of viral strains and mediate ADCC in cell culture. We analyzed the capacities of 9 nnAbs and 5 bNAbs to eliminate infected cells. We selected 18 HIV-1 strains, including virus reactivated from the reservoir of HIV-positive individuals and transmitted-founder isolates. We report that the nnAbs bind poorly to cells infected with primary HIV-1 strains and do not mediate potent ADCC. Overall, our data show that the breadth of recognition of HIV-1 by nnAbs is narrow.
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36
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HIV-1 gp120 envelope glycoprotein determinants for cytokine burst in human monocytes. PLoS One 2017; 12:e0174550. [PMID: 28346521 PMCID: PMC5367833 DOI: 10.1371/journal.pone.0174550] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/10/2017] [Indexed: 11/26/2022] Open
Abstract
The first step of HIV infection involves the interaction of the gp120 envelope glycoprotein to its receptor CD4, mainly expressed on CD4+ T cells. Besides its role on HIV-1 entry, the gp120 has been shown to be involved in the production of IL-1, IL-6, CCL20 and other innate response cytokines by bystander, uninfected CD4+ T cells and monocytes. However, the gp120 determinants involved in these functions are not completely understood. Whether signalling leading to cytokine production is due to CD4 or other receptors is still unclear. Enhanced chemokine receptor binding and subsequent clustering receptors may lead to cytokine production. By using a comprehensive panel of gp120 mutants, here we show that CD4 binding is mandatory for cytokine outburst in monocytes. Our data suggest that targeting monocytes in HIV-infected patients might decrease systemic inflammation and the potential tissue injury associated with the production of inflammatory cytokines. Understanding how gp120 mediates a cytokine burst in monocytes might help develop new approaches to improve the chronic inflammation that persists in these patients despite effective suppression of viremia by antiretroviral therapy.
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37
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Influence of the Envelope gp120 Phe 43 Cavity on HIV-1 Sensitivity to Antibody-Dependent Cell-Mediated Cytotoxicity Responses. J Virol 2017; 91:JVI.02452-16. [PMID: 28100618 DOI: 10.1128/jvi.02452-16] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/12/2017] [Indexed: 01/29/2023] Open
Abstract
HIV-1-infected cells presenting envelope glycoproteins (Env) in the CD4-bound conformation on their surface are preferentially targeted by antibody-dependent cellular-mediated cytotoxicity (ADCC). HIV-1 has evolved sophisticated mechanisms to avoid the exposure of Env ADCC epitopes by downregulating CD4 and by limiting the overall amount of Env on the cell surface. In HIV-1, substitution of large residues such as histidine or tryptophan for serine 375 (S375H/W) in the gp120 Phe 43 cavity, where Phe 43 of CD4 contacts gp120, results in the spontaneous sampling of an Env conformation closer to the CD4-bound state. While residue S375 is well conserved in the majority of group M HIV-1 isolates, CRF01_AE strains have a naturally occurring histidine at this position (H375). Interestingly, CRF01_AE is the predominant circulating strain in Thailand, where the RV144 trial took place. In this trial, which resulted in a modest degree of protection, ADCC responses were identified as being part of the correlate of protection. Here we investigate the influence of the Phe 43 cavity on ADCC responses. Filling this cavity with a histidine or tryptophan residue in Env with a natural serine residue at this position (S375H/W) increased the susceptibility of HIV-1-infected cells to ADCC. Conversely, the replacement of His 375 by a serine residue (H375S) within HIV-1 CRF01_AE decreased the efficiency of the ADCC response. Our results raise the intriguing possibility that the presence of His 375 in the circulating strain where the RV144 trial was held contributed to the observed vaccine efficacy.IMPORTANCE HIV-1-infected cells presenting Env in the CD4-bound conformation on their surface are preferentially targeted by ADCC mediated by HIV-positive (HIV+) sera. Here we show that the gp120 Phe 43 cavity modulates the propensity of Env to sample this conformation and therefore affects the susceptibility of infected cells to ADCC. CRF01_AE HIV-1 strains have an unusual Phe 43 cavity-filling His 375 residue, which increases the propensity of Env to sample the CD4-bound conformation, thereby increasing susceptibility to ADCC.
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38
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Nedellec R, Herbeck JT, Hunt PW, Deeks SG, Mullins JI, Anton ED, Reeves JD, Mosier DE. High-Sequence Diversity and Rapid Virus Turnover Contribute to Higher Rates of Coreceptor Switching in Treatment-Experienced Subjects with HIV-1 Viremia. AIDS Res Hum Retroviruses 2017; 33:234-245. [PMID: 27604829 DOI: 10.1089/aid.2016.0153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Coreceptor switching from CCR5 to CXCR4 is common during chronic HIV-1 infection, but is even more common in individuals who have failed antiretroviral therapy (ART). Prior studies have suggested rapid mutation and/or recombination of HIV-1 envelope (env) genes during coreceptor switching. We compared the functional and genotypic changes in env of viruses from viremic subjects who had failed ART just before and after coreceptor switching and compared those to viruses from matched subjects without coreceptor switching. Analysis of multiple unique functional env clones from each subject revealed extensive diversity at both sample time points and rapid diversification of sequences during the 4-month interval in viruses from both 9 subjects with coreceptor switching and 15 control subjects. Only two subjects had envs with evidence of recombination. Three findings distinguished env clones from subjects with coreceptor switching from controls: (1) lower entry efficiency via CCR5; (2) longer V1/V2 regions; and (3), lower nadir CD4 T cell counts during prior years of infection. Most of these subjects harbored virus with lower replicative capacity associated with protease (PR) and/or reverse transcriptase inhibitor resistance mutations, and the extensive diversification tended to lead either to improved entry efficiency via CCR5 or the gain of entry function via CXCR4. These results suggest that R5X4 or X4 variants emerge from a diverse, low-fitness landscape shaped by chronic infection, multiple ART resistance mutations, the availability of target cells, and reduced entry efficiency via CCR5.
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Affiliation(s)
- Rebecca Nedellec
- Department of Immunology and Microbial Science, IMM-7, The Scripps Research Institute, La Jolla, California
| | - Joshua T. Herbeck
- International Clinical Research Center, Department of Global Health, University of Washington, Seattle, Washington
| | - Peter W. Hunt
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, California
| | - Steven G. Deeks
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, California
| | - James I. Mullins
- Department of Microbiology, University of Washington, Seattle, Washington
| | - Elizabeth D. Anton
- Monogram Biosciences, Laboratory Corporation of America® Holding, Virology Research and Development, South San Francisco, California
| | - Jacqueline D. Reeves
- Monogram Biosciences, Laboratory Corporation of America® Holding, Virology Research and Development, South San Francisco, California
| | - Donald E. Mosier
- Department of Immunology and Microbial Science, IMM-7, The Scripps Research Institute, La Jolla, California
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39
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Histidine 375 Modulates CD4 Binding in HIV-1 CRF01_AE Envelope Glycoproteins. J Virol 2017; 91:JVI.02151-16. [PMID: 27928014 DOI: 10.1128/jvi.02151-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 11/29/2016] [Indexed: 01/11/2023] Open
Abstract
The envelope glycoproteins (Envs) from human immunodeficiency virus type 1 (HIV-1) mediate viral entry. The binding of the HIV-1 gp120 glycoprotein to CD4 triggers conformational changes in gp120 that allow high-affinity binding to its coreceptors. In contrast to all other Envs from the same phylogenetic group, M, which possess a serine (S) at position 375, those from CRF01_AE strains possess a histidine (H) at this location. This residue is part of the Phe43 cavity, where residue 43 of CD4 (a phenylalanine) engages with gp120. Here we evaluated the functional consequences of replacing this residue in two CRF01_AE Envs (CM244 and 92TH023) by a serine. We observed that reversion of amino acid 375 to a serine (H375S) resulted in a loss of functionality of both CRF01_AE Envs as measured by a dramatic loss in infectivity and ability to mediate cell-to-cell fusion. While no effects on processing or trimer stability of these variants were observed, decreased functionality could be linked to a major defect in CD4 binding induced by the replacement of H375 by a serine. Importantly, mutations of residues 61 (layer 1), 105 and 108 (layer 2), and 474 to 476 (layer 3) of the CRF01_AE gp120 inner domain layers to the consensus residues present in group M restored CD4 binding and wild-type levels of infectivity and cell-to-cell fusion. These results suggest a functional coevolution between the Phe43 cavity and the gp120 inner domain layers. Altogether, our observations describe the functional importance of amino acid 375H in CRF01_AE envelopes. IMPORTANCE A highly conserved serine located at position 375 in group M is replaced by a histidine in CRF01_AE Envs. Here we show that H375 is required for efficient CRF01_AE Env binding to CD4. Moreover, this work suggests that specific residues of the gp120 inner domain layers have coevolved with H375 in order to maintain its ability to mediate viral entry.
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40
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Ferrari G, Haynes BF, Koenig S, Nordstrom JL, Margolis DM, Tomaras GD. Envelope-specific antibodies and antibody-derived molecules for treating and curing HIV infection. Nat Rev Drug Discov 2016; 15:823-834. [PMID: 27725635 PMCID: PMC5549020 DOI: 10.1038/nrd.2016.173] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
HIV-1 is a retrovirus that integrates into host chromatin and can remain transcriptionally quiescent in a pool of immune cells. This characteristic enables HIV-1 to evade both host immune responses and antiretroviral drugs, leading to persistent infection. Upon reactivation of proviral gene expression, HIV-1 envelope (HIV-1 Env) glycoproteins are expressed on the cell surface, transforming latently infected cells into targets for HIV-1 Env-specific monoclonal antibodies (mAbs), which can engage immune effector cells to kill productively infected CD4+ T cells and thus limit the spread of progeny virus. Recent innovations in antibody engineering have resulted in novel immunotherapeutics such as bispecific dual-affinity re-targeting (DART) molecules and other bi- and trispecific antibody designs that can recognize HIV-1 Env and recruit cytotoxic effector cells to kill CD4+ T cells latently infected with HIV-1. Here, we review these immunotherapies, which are designed with the goal of curing HIV-1 infection.
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Affiliation(s)
- Guido Ferrari
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27710, USA
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
- Department of Medicine, Duke University, Durham, North Carolina 27710, USA
- Department of Immunology, Duke University, Durham, North Carolina 27710, USA
| | | | | | - David M Margolis
- University of North Carolina at Chapel Hill HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Georgia D Tomaras
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27710, USA
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
- Department of Immunology, Duke University, Durham, North Carolina 27710, USA
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41
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Mortimer GM, Minchin RF. Cryptic epitopes and functional diversity in extracellular proteins. Int J Biochem Cell Biol 2016; 81:112-120. [DOI: 10.1016/j.biocel.2016.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/28/2023]
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42
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Enhancing Virion Tethering by BST2 Sensitizes Productively and Latently HIV-infected T cells to ADCC Mediated by Broadly Neutralizing Antibodies. Sci Rep 2016; 6:37225. [PMID: 27853288 PMCID: PMC5112552 DOI: 10.1038/srep37225] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/26/2016] [Indexed: 02/01/2023] Open
Abstract
Binding of anti-HIV antibodies (Abs) to envelope (Env) glycoproteins on infected cells can mark them for elimination via antibody-dependent cell-mediated cytotoxicity (ADCC). BST2, a type I interferon (IFN)-stimulated restriction factor that anchors nascent Env-containing virions at the surface of infected cells has been shown to enhance ADCC functions. In a comprehensive analysis of ADCC potency by neutralizing anti-HIV Abs (NAbs), we show in this study that NAbs are capable of mediating ADCC against HIV-infected T cells with 3BNC117, PGT126 and PG9 being most efficient. We demonstrate that HIV-induced BST2 antagonism effectively attenuates Ab binding and ADCC responses mediated by all classes of NAbs that were tested. Interestingly, IFNα treatment can reverse this effect in a BST2-dependent manner. Importantly, while reactivated latent T cell lines display some susceptibility to ADCC mediated by broadly NAbs, inactivating BST2 viral countermeasures and/or exogenous IFNα augment their elimination. Overall, our findings support the notion that NAbs can induce ADCC. They highlight that while BST2 antagonism by HIV promotes ADCC evasion, strategies aimed at restoring BST2 restriction could improve anti-HIV responses and potentially provide a means to eliminate reactivated cells in latent reservoirs.
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43
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Cryo-EM structure of a CD4-bound open HIV-1 envelope trimer reveals structural rearrangements of the gp120 V1V2 loop. Proc Natl Acad Sci U S A 2016; 113:E7151-E7158. [PMID: 27799557 DOI: 10.1073/pnas.1615939113] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The HIV-1 envelope (Env) glycoprotein, a trimer of gp120-gp41 heterodimers, relies on conformational flexibility to function in fusing the viral and host membranes. Fusion is achieved after gp120 binds to CD4, the HIV-1 receptor, and a coreceptor, capturing an open conformational state in which the fusion machinery on gp41 gains access to the target cell membrane. In the well-characterized closed Env conformation, the gp120 V1V2 loops interact at the apex of the Env trimer. Less is known about the structure of the open CD4-bound state, in which the V1V2 loops must rearrange and separate to allow access to the coreceptor binding site. We identified two anti-HIV-1 antibodies, the coreceptor mimicking antibody 17b and the gp120-gp41 interface-spanning antibody 8ANC195, that can be added as Fabs to a soluble native-like Env trimer to stabilize it in a CD4-bound conformation. Here, we present an 8.9-Å cryo-electron microscopy structure of a BG505 Env-sCD4-17b-8ANC195 complex, which reveals large structural rearrangements in gp120, but small changes in gp41, compared with closed Env structures. The gp120 protomers are rotated and separated in the CD4-bound structure, and the three V1V2 loops are displaced by ∼40 Å from their positions at the trimer apex in closed Env to the sides of the trimer in positions adjacent to, and interacting with, the three bound CD4s. These results are relevant to understanding CD4-induced conformational changes leading to coreceptor binding and fusion, and HIV-1 Env conformational dynamics, and describe a target structure relevant to drug design and vaccine efforts.
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44
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Richard J, Pacheco B, Gohain N, Veillette M, Ding S, Alsahafi N, Tolbert WD, Prévost J, Chapleau JP, Coutu M, Jia M, Brassard N, Park J, Courter JR, Melillo B, Martin L, Tremblay C, Hahn BH, Kaufmann DE, Wu X, Smith AB, Sodroski J, Pazgier M, Finzi A. Co-receptor Binding Site Antibodies Enable CD4-Mimetics to Expose Conserved Anti-cluster A ADCC Epitopes on HIV-1 Envelope Glycoproteins. EBioMedicine 2016; 12:208-218. [PMID: 27633463 PMCID: PMC5078604 DOI: 10.1016/j.ebiom.2016.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 11/06/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) has evolved a sophisticated strategy to conceal conserved epitopes of its envelope glycoproteins (Env) recognized by antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies. These antibodies, which are present in the sera of most HIV-1-infected individuals, preferentially recognize Env in its CD4-bound conformation. Accordingly, recent studies showed that small CD4-mimetics (CD4mc) able to “push” Env into this conformation sensitize HIV-1-infected cells to ADCC mediated by HIV + sera. Here we test whether CD4mc also expose epitopes recognized by anti-cluster A monoclonal antibodies such as A32, thought to be responsible for the majority of ADCC activity present in HIV + sera and linked to decreased HIV-1 transmission in the RV144 trial. We made the surprising observation that CD4mc are unable to enhance recognition of HIV-1-infected cells by this family of antibodies in the absence of antibodies such as 17b, which binds a highly conserved CD4-induced epitope overlapping the co-receptor binding site (CoRBS). Our results indicate that CD4mc initially open the trimeric Env enough to allow the binding of CoRBS antibodies but not anti-cluster A antibodies. CoRBS antibody binding further opens the trimeric Env, allowing anti-cluster A antibody interaction and sensitization of infected cells to ADCC. Therefore, ADCC responses mediated by cluster A antibodies in HIV-positive sera involve a sequential opening of the Env trimer on the surface of HIV-1-infected cells. The understanding of the conformational changes required to expose these vulnerable Env epitopes might be important in the design of new strategies aimed at fighting HIV-1. CD4-mimetics fail to enhance recognition of infected cells by anti-cluster A antibodies (Abs). Co-receptor binding site Abs in conjunction with CD4-mimetics allow binding of Env by anti-cluster A Abs. Co-receptor binding site Abs help CD4-mimetics sensitize HIV-1-infected cells to ADCC.
HIV-1 developed sophisticated strategies to conceal vulnerable epitopes of its envelope glycoproteins (Env) recognized by antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies. CD4-mimetics (CD4mc) were shown to sensitize HIV-1-infected cells to ADCC induced by HIV + sera. Here we show that this response requires a sequential opening of Env at the surface of HIV-1-infected cells. Co-receptor binding site antibodies, also present in HIV + sera, are required to expose ADCC-mediating epitopes recognized by anti-cluster A antibodies upon CD4mc addition. The understanding of the conformational changes required to expose anti-cluster A epitopes might be important in the design of new strategies aimed at fighting HIV-1.
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Affiliation(s)
- Jonathan Richard
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada.
| | | | - Neelakshi Gohain
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Maxime Veillette
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Shilei Ding
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Nirmin Alsahafi
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - William D Tolbert
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jérémie Prévost
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Jean-Philippe Chapleau
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | | | - Manxue Jia
- Aaron Diamond AIDS Research Center, Affiliate of the Rockefeller University, New York, NY, USA
| | | | - Jongwoo Park
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Joel R Courter
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Bruno Melillo
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Loïc Martin
- CEA, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Cécile Tremblay
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Daniel E Kaufmann
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard, Cambridge, MA 02139-3583, USA; Department of Medicine, Université de Montréal, Montreal, QC H3C 3T5, Canada; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xueling Wu
- Aaron Diamond AIDS Research Center, Affiliate of the Rockefeller University, New York, NY, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Division of AIDS, Harvard Medical School, Boston, MA 02115, USA; Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
| | - Marzena Pazgier
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada.
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45
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Deshpande S, Patil S, Kumar R, Hermanus T, Murugavel KG, Srikrishnan AK, Solomon S, Morris L, Bhattacharya J. HIV-1 clade C escapes broadly neutralizing autologous antibodies with N332 glycan specificity by distinct mechanisms. Retrovirology 2016; 13:60. [PMID: 27576440 PMCID: PMC5006590 DOI: 10.1186/s12977-016-0297-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 08/17/2016] [Indexed: 12/30/2022] Open
Abstract
The glycan supersite centered on N332 in the V3 base of the HIV-1 envelope (Env) is a target for broadly neutralizing antibodies (bnAbs) such as PGT121 and PGT128. In this study, we examined the basis of resistance of HIV-1 clade C Envs obtained from broadly cross neutralizing (BCN) plasma of an Indian donor with N332 specificity. Pseudotyped viruses expressing autologous envs were found to be resistant to autologous BCN plasma as well as to PGT121 and PGT128 mAbs despite the majority of Envs containing an intact N332 residue. While resistance of one of the Envs to neutralization by autologous plasma antibodies with shorter V1 loop length was found to be correlated with a N332S mutation, resistance to neutralization of rest of the Envs was found to be associated with longer V1 loop length and acquisition of protective N-glycans. In summary, we show evidence of escape of circulating HIV-1 clade C in an individual from autologous BCN antibodies by three distinct mechanisms.
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Affiliation(s)
- Suprit Deshpande
- HIV Vaccine Translational Research Laboratory, NCR Biotech Science Cluster, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Shilpa Patil
- HIV Vaccine Translational Research Laboratory, NCR Biotech Science Cluster, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Rajesh Kumar
- HIV Vaccine Translational Research Laboratory, NCR Biotech Science Cluster, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Tandile Hermanus
- National Institute of Communicable Diseases, Johannesburg, South Africa
| | | | | | - Suniti Solomon
- YRG Care Center for AIDS Research & Education, Chennai, 600113, India
| | - Lynn Morris
- National Institute of Communicable Diseases, Johannesburg, South Africa
| | - Jayanta Bhattacharya
- HIV Vaccine Translational Research Laboratory, NCR Biotech Science Cluster, Translational Health Science and Technology Institute, Faridabad, Haryana, India. .,International AIDS Vaccine Initiative, New York, NY, USA.
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46
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Hikichi Y, Yokoyama M, Takemura T, Fujino M, Kumakura S, Maeda Y, Yamamoto N, Sato H, Matano T, Murakami T. Increased HIV-1 sensitivity to neutralizing antibodies by mutations in the Env V3-coding region for resistance to CXCR4 antagonists. J Gen Virol 2016; 97:2427-2440. [PMID: 27368421 DOI: 10.1099/jgv.0.000536] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HIV-1 passage in cell culture in the presence of chemokine receptor antagonists can result in selection of viruses with env mutations that confer resistance to these inhibitors. In the present study, we examined the effect of HIV-1env mutations that confer resistance to CXCR4 antagonists on envelope (Env) sensitivity to neutralizing antibodies (NAbs). Serial passage of CXCR4-tropic HIV-1 NL4-3 in PM1/CCR5 cells under CXCR4 antagonists KRH-3955, AMD3100 and AMD070 yielded two KRH-3955-resistant, one AMD3100-resistant and one AMD070-resistant viruses. These viruses had multiple env mutations including the Env gp120 V3 region. The majority of viruses having these CXCR4 antagonist-resistant Envs showed higher sensitivity to NAbs 447-52D, b12 and 2F5 targeting the V3 region, the gp120 CD4-binding site and the gp41 membrane proximal region, respectively, compared to NL4-3 WT virus. Recombinant NL4-3 viruses with the V3-coding region replaced with those derived from the CXCR4 antagonist-resistant viruses showed increased sensitivity to NAbs b12, 2F5 and 447-52D. Molecular dynamics simulations of Env gp120 outer domains predicted that the V3 mutations increased levels of fluctuations at the tip and stem of the V3 loop. These results indicate that mutations in the V3-coding region that result in loss of viral sensitivity to CXCR4 antagonists increase viral sensitivity to NAbs, providing insights into our understanding of the interplay of viral Env accessibility to chemokine receptors and sensitivity to NAbs.
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Affiliation(s)
- Yuta Hikichi
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, 162-8640 Tokyo, Japan.,The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, 108-8639 Tokyo, Japan
| | - Masaru Yokoyama
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashi Murayama-shi, 208-0011 Tokyo, Japan
| | - Taichiro Takemura
- Vietnam Research Station, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, 852-8523 Nagasaki, Japan
| | - Masayuki Fujino
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, 162-8640 Tokyo, Japan
| | - Sei Kumakura
- Kureha Corporation, 3-26-2, Hyakunin-cho, Shinjuku-ku, 169-8503 Tokyo, Japan
| | - Yosuke Maeda
- Department of Medical Virology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, 860-8556 Kumamoto, Japan
| | - Naoki Yamamoto
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, 162-8640 Tokyo, Japan
| | - Hironori Sato
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashi Murayama-shi, 208-0011 Tokyo, Japan
| | - Tetsuro Matano
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, 162-8640 Tokyo, Japan.,The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, 108-8639 Tokyo, Japan
| | - Tsutomu Murakami
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, 162-8640 Tokyo, Japan
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47
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Comparison of Antibody-Dependent Cell-Mediated Cytotoxicity and Virus Neutralization by HIV-1 Env-Specific Monoclonal Antibodies. J Virol 2016; 90:6127-6139. [PMID: 27122574 DOI: 10.1128/jvi.00347-16] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/16/2016] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED Although antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FL or SHIVAD8-EO ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection. IMPORTANCE This study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.
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48
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Robinson JE, Hastie KM, Cross RW, Yenni RE, Elliott DH, Rouelle JA, Kannadka CB, Smira AA, Garry CE, Bradley BT, Yu H, Shaffer JG, Boisen ML, Hartnett JN, Zandonatti MA, Rowland MM, Heinrich ML, Martínez-Sobrido L, Cheng B, de la Torre JC, Andersen KG, Goba A, Momoh M, Fullah M, Gbakie M, Kanneh L, Koroma VJ, Fonnie R, Jalloh SC, Kargbo B, Vandi MA, Gbetuwa M, Ikponmwosa O, Asogun DA, Okokhere PO, Follarin OA, Schieffelin JS, Pitts KR, Geisbert JB, Kulakoski PC, Wilson RB, Happi CT, Sabeti PC, Gevao SM, Khan SH, Grant DS, Geisbert TW, Saphire EO, Branco LM, Garry RF. Most neutralizing human monoclonal antibodies target novel epitopes requiring both Lassa virus glycoprotein subunits. Nat Commun 2016; 7:11544. [PMID: 27161536 PMCID: PMC4866400 DOI: 10.1038/ncomms11544] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/07/2016] [Indexed: 01/19/2023] Open
Abstract
Lassa fever is a severe multisystem disease that often has haemorrhagic manifestations. The epitopes of the Lassa virus (LASV) surface glycoproteins recognized by naturally infected human hosts have not been identified or characterized. Here we have cloned 113 human monoclonal antibodies (mAbs) specific for LASV glycoproteins from memory B cells of Lassa fever survivors from West Africa. One-half bind the GP2 fusion subunit, one-fourth recognize the GP1 receptor-binding subunit and the remaining fourth are specific for the assembled glycoprotein complex, requiring both GP1 and GP2 subunits for recognition. Notably, of the 16 mAbs that neutralize LASV, 13 require the assembled glycoprotein complex for binding, while the remaining 3 require GP1 only. Compared with non-neutralizing mAbs, neutralizing mAbs have higher binding affinities and greater divergence from germline progenitors. Some mAbs potently neutralize all four LASV lineages. These insights from LASV human mAb characterization will guide strategies for immunotherapeutic development and vaccine design.
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Affiliation(s)
- James E Robinson
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Kathryn M Hastie
- Department of Immunology and Microbial Science, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Robert W Cross
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, Texas 77555, USA
| | - Rachael E Yenni
- Department of Microbiology and Immunology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Deborah H Elliott
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Julie A Rouelle
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Chandrika B Kannadka
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Ashley A Smira
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Courtney E Garry
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA.,Autoimmune Technologies, LLC, 1010 Common St #1705, New Orleans, Louisiana 70112, USA
| | - Benjamin T Bradley
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Haini Yu
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Jeffrey G Shaffer
- Department of Biostatistics and Bioinformatics, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana 70112, USA
| | - Matt L Boisen
- Corgenix, Inc., 11575 Main Street #400, Broomfield, Colorado 80020, USA
| | - Jessica N Hartnett
- Department of Microbiology and Immunology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Michelle A Zandonatti
- Department of Immunology and Microbial Science, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Megan M Rowland
- Zalgen Labs, LLC, 20271 Goldenrod Lane, Suite 2083, Germantown, Maryland 20876, USA
| | - Megan L Heinrich
- Zalgen Labs, LLC, 20271 Goldenrod Lane, Suite 2083, Germantown, Maryland 20876, USA
| | - Luis Martínez-Sobrido
- Department of Microbiology and Immunology, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642, USA
| | - Benson Cheng
- Department of Microbiology and Immunology, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642, USA
| | - Juan C de la Torre
- Department of Immunology and Microbial Science, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Kristian G Andersen
- Department of Immunology and Microbial Science, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Augustine Goba
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone
| | - Mambu Momoh
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone.,Department of Laboratory Sciences Polytechnic College, 2 Combema Road, Kenema, Sierra Leone
| | - Mohamed Fullah
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone.,Department of Laboratory Sciences Polytechnic College, 2 Combema Road, Kenema, Sierra Leone
| | - Michael Gbakie
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone
| | - Lansana Kanneh
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone
| | - Veronica J Koroma
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone
| | - Richard Fonnie
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone
| | - Simbirie C Jalloh
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone
| | - Brima Kargbo
- Ministry of Health and Sanitation, 4th Floor Youyi Building, Freetown, Sierra Leone
| | - Mohamed A Vandi
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone.,Ministry of Health and Sanitation, 4th Floor Youyi Building, Freetown, Sierra Leone
| | - Momoh Gbetuwa
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone.,Ministry of Health and Sanitation, 4th Floor Youyi Building, Freetown, Sierra Leone
| | - Odia Ikponmwosa
- Department of Medicine, Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Km. 87, Benin/Auchi Road, Irrua, Nigeria
| | - Danny A Asogun
- Department of Medicine, Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Km. 87, Benin/Auchi Road, Irrua, Nigeria
| | - Peter O Okokhere
- Department of Medicine, Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Km. 87, Benin/Auchi Road, Irrua, Nigeria
| | - Onikepe A Follarin
- Department of Medicine, Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Km. 87, Benin/Auchi Road, Irrua, Nigeria.,Department of Biological Sciences, College of Natural Sciences, Redeemer's University, Off Gbongan-Oshogbo Road, Ede, Nigeria.,African Center of Excellence for Genomics of Infectious Disease (ACEGID), Redeemer's University, Off Gbongan-Oshogbo Road, Ede, Nigeria
| | - John S Schieffelin
- Section of Infectious Disease, Department of Pediatrics, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA.,Section of Infectious Disease, Department of Internal Medicine, Tulane University School of Medicine, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA
| | - Kelly R Pitts
- Corgenix, Inc., 11575 Main Street #400, Broomfield, Colorado 80020, USA
| | - Joan B Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, Texas 77555, USA
| | - Peter C Kulakoski
- Autoimmune Technologies, LLC, 1010 Common St #1705, New Orleans, Louisiana 70112, USA
| | - Russell B Wilson
- Autoimmune Technologies, LLC, 1010 Common St #1705, New Orleans, Louisiana 70112, USA
| | - Christian T Happi
- Department of Medicine, Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Km. 87, Benin/Auchi Road, Irrua, Nigeria.,Department of Biological Sciences, College of Natural Sciences, Redeemer's University, Off Gbongan-Oshogbo Road, Ede, Nigeria.,African Center of Excellence for Genomics of Infectious Disease (ACEGID), Redeemer's University, Off Gbongan-Oshogbo Road, Ede, Nigeria
| | - Pardis C Sabeti
- Department of Organismic and Evolutionary Biology, Center for Systems Biology, Harvard University, 1350 Massachusetts Avenue, Cambridge, Massachusetts 02138, USA.,Center for Systems Biology, Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, USA.,Department of Immunology and Infectious Disease, Harvard School of Public Health, 677 Huntington Avenue, Boston, Massachusetts 02115, USA
| | - Sahr M Gevao
- Department of Medicine, University of Sierra Leone, Freetown, Sierra Leone
| | - S Humarr Khan
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone.,Ministry of Health and Sanitation, 4th Floor Youyi Building, Freetown, Sierra Leone
| | - Donald S Grant
- Viral Hemorrhagic Fever Program, Kenema Government Hospital, 1 Combema Road, Kenema, Sierra Leone.,Ministry of Health and Sanitation, 4th Floor Youyi Building, Freetown, Sierra Leone
| | - Thomas W Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, Texas 77555, USA
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.,The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Luis M Branco
- Zalgen Labs, LLC, 20271 Goldenrod Lane, Suite 2083, Germantown, Maryland 20876, USA
| | - Robert F Garry
- Department of Microbiology and Immunology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA.,Zalgen Labs, LLC, 20271 Goldenrod Lane, Suite 2083, Germantown, Maryland 20876, USA
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49
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Range of CD4-Bound Conformations of HIV-1 gp120, as Defined Using Conditional CD4-Induced Antibodies. J Virol 2016; 90:4481-4493. [PMID: 26889042 DOI: 10.1128/jvi.03206-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/14/2016] [Indexed: 01/23/2023] Open
Abstract
UNLABELLED The HIV envelope binds cellular CD4 and undergoes a range of conformational changes that lead to membrane fusion and delivery of the viral nucleocapsid into the cellular cytoplasm. This binding to CD4 reveals cryptic and highly conserved epitopes, the molecular nature of which is still not fully understood. The atomic structures of CD4 complexed with gp120 core molecules (a form of gp120 in which the V1, V2, and V3 loops and N and C termini have been truncated) have indicated that a hallmark feature of the CD4-bound conformation is the bridging sheet minidomain. Variations in the orientation of the bridging sheet hairpins have been revealed when CD4-liganded gp120 was compared to CD4-unliganded trimeric envelope structures. Hence, there appears to be a number of conformational transitions possible in HIV-1 monomeric gp120 that are affected by CD4 binding. The spectrum of CD4-bound conformations has been interrogated in this study by using a well-characterized panel of conditional, CD4-induced (CD4i) monoclonal antibodies (MAbs) that bind HIV-1 gp120 and its mutations under various conditions. Two distinct CD4i epitopes of the outer domain were studied: the first comprises the bridging sheet, while the second contains elements of the V2 loop. Furthermore, we show that the unliganded extended monomeric core of gp120 (coree) assumes an intermediate CD4i conformation in solution that further undergoes detectable rearrangements upon association with CD4. These discoveries impact both accepted paradigms concerning gp120 structure and the field of HIV immunogen design. IMPORTANCE Elucidation of the conformational transitions that the HIV-1 envelope protein undergoes during the course of entry into CD4(+)cells is fundamental to our understanding of HIV biology. The binding of CD4 triggers a range of gp120 structural rearrangements that could present targets for future drug design and development of preventive vaccines. Here we have systematically interrogated and scrutinized these conformational transitions using a panel of antibody probes that share a specific preference for the CD4i conformations. These have been employed to study a collection of gp120 mutations and truncations. Through these analyses, we propose 4 distinct sequential steps in CD4i transitions of gp120 conformations, each defined by antibody specificities and structural requirements of the HIV envelope monomer. As a result, we not only provide new insights into this dynamic process but also define probes to further investigate HIV infection.
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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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