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López CA, Alam SM, Derdeyn CA, Haynes BF, Gnanakaran S. Influence of membrane on the antigen presentation of the HIV-1 envelope membrane proximal external region (MPER). Curr Opin Struct Biol 2024; 88:102897. [PMID: 39173417 DOI: 10.1016/j.sbi.2024.102897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/18/2024] [Accepted: 07/19/2024] [Indexed: 08/24/2024]
Abstract
The membrane proximal external region (MPER) of the HIV envelope glycoproteins has generated renewed interest after a recent phase I vaccine trial that presented MPER lipid-peptide epitopes demonstrated promise to elicit a broad neutralization response. The antigenicity of MPER is intimately associated with the membrane, and its presentation relies significantly on the lipid composition. This review brings together recent findings on the influence of membranes on the conformation of MPER and its recognition by broadly neutralizing antibodies. Specifically, the review highlights the importance of properly accounting for the balance between protein-protein and membrane-protein interactions in vaccine design.
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Affiliation(s)
- Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - S Munir Alam
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Cynthia A Derdeyn
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Barton F Haynes
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA; Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA; Department of Immunology, Duke University of School of Medicine, Durham, NC, USA.
| | - Sandrasegaram Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
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2
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Rao PG, Lambert GS, Upadhyay C. Broadly neutralizing antibody epitopes on HIV-1 particles are exposed after virus interaction with host cells. J Virol 2023; 97:e0071023. [PMID: 37681958 PMCID: PMC10537810 DOI: 10.1128/jvi.00710-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/07/2023] [Indexed: 09/09/2023] Open
Abstract
The envelope (Env) glycoproteins on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAbs) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes, including V2i, the gp120-g41 interface, and gp41-MPER, are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by the pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where the virus-mAb mix was pre-incubated/not pre-incubated for 1 hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use. IMPORTANCE The human immunodeficiency virus (HIV-1) envelope (Env) glycoprotein mediates viral entry and is the sole target of neutralizing antibodies. Our data suggest that antibody epitopes including V2q (e.g., PG9, PGT145), CD4bs (e.g., VRC01, 3BNC117), and V3 (2219, 2557) are masked on HIV-1 particles. The PG9 and 2219 epitopes became accessible for binding after conformational unmasking was induced by the pre-binding of select mAbs. Attempts to understand the masking mechanism led to the revelation that interaction between virus and host cells is needed to sensitize the virions for neutralization by broadly neutralizing antibodies (bNAbs). These data provide insight on how bNAbs may gain access to these occluded epitopes to exert their neutralization effects and block HIV-1 infection. These findings have important implications for the way we evaluate the neutralizing efficacy of antibodies and can potentially guide vaccine design.
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Affiliation(s)
- Priyanka Gadam Rao
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gregory S. Lambert
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Chitra Upadhyay
- Division of Infectious Disease, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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3
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Piédrola I, Martínez S, Gradillas A, Villaseñor A, Alonso-Herranz V, Sánchez-Vera I, Escudero E, Martín-Antoniano IA, Varona JF, Ruiz A, Castellano JM, Muñoz Ú, Sádaba MC. Deficiency in the production of antibodies to lipids correlates with increased lipid metabolism in severe COVID-19 patients. Front Immunol 2023; 14:1188786. [PMID: 37426663 PMCID: PMC10327431 DOI: 10.3389/fimmu.2023.1188786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/26/2023] [Indexed: 07/11/2023] Open
Abstract
Background Antibodies to lipids are part of the first line of defense against microorganisms and regulate the pro/anti-inflammatory balance. Viruses modulate cellular lipid metabolism to enhance their replication, and some of these metabolites are proinflammatory. We hypothesized that antibodies to lipids would play a main role of in the defense against SARS-CoV-2 and thus, they would also avoid the hyperinflammation, a main problem in severe condition patients. Methods Serum samples from COVID-19 patients with mild and severe course, and control group were included. IgG and IgM to different glycerophospholipids and sphingolipids were analyzed using a high-sensitive ELISA developed in our laboratory. A lipidomic approach for studying lipid metabolism was performed using ultra-high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). Results Mild and severe COVID-19 patients had higher levels of IgM to glycerophosphocholines than control group. Mild COVID-19 patients showed higher levels of IgM to glycerophosphoinositol, glycerophosphoserine and sulfatides than control group and mild cases. 82.5% of mild COVID-19 patients showed IgM to glycerophosphoinositol or glycerophosphocholines plus sulfatides or glycerophosphoserines. Only 35% of severe cases and 27.5% of control group were positive for IgM to these lipids. Lipidomic analysis identify a total of 196 lipids, including 172 glycerophospholipids and 24 sphingomyelins. Increased levels of lipid subclasses belonging to lysoglycerophospholipids, ether and/or vinyl-ether-linked glycerophospholipids, and sphingomyelins were observed in severe COVID-19 patients, when compared with those of mild cases and control group. Conclusion Antibodies to lipids are essential for defense against SARS-CoV-2. Patients with low levels of anti-lipid antibodies have an elevated inflammatory response mediated by lysoglycerophospholipids. These findings provide novel prognostic biomarkers and therapeutic targets.
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Affiliation(s)
- Ignacio Piédrola
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Sara Martínez
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Ana Gradillas
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Alma Villaseñor
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Vanesa Alonso-Herranz
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Isabel Sánchez-Vera
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Esther Escudero
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - Isabel A. Martín-Antoniano
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
- Genetic and Molecular Epidemiology Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Jose Felipe Varona
- Servicio de Medicina Interna, Hospital Universitario Hospitales de Madrid (HM), Boadilla del Monte, Madrid, Spain
| | - Andrés Ruiz
- Servicio de Medicina Interna, Hospital Universitario Hospitales de Madrid (HM), Boadilla del Monte, Madrid, Spain
| | - Jose María Castellano
- Servicio de Medicina Interna, Hospital Universitario Hospitales de Madrid (HM), Boadilla del Monte, Madrid, Spain
| | - Úrsula Muñoz
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
| | - María C. Sádaba
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, Madrid, Spain
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4
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Rao PG, Lambert GS, Upadhyay C. Broadly Neutralizing Antibody Epitopes on HIV-1 Particles are exposed after Virus Interaction with Host Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524996. [PMID: 36711466 PMCID: PMC9882293 DOI: 10.1101/2023.01.20.524996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The envelope glycoproteins (Env) on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAb) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes including V2i, gp120-g41 interface, and gp41-MPER are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where virus-mAb mix was pre-incubated/not pre-incubated for one hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are the ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use.
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5
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Labombarde JG, Pillai MR, Wehenkel M, Lin CY, Keating R, Brown SA, Crawford JC, Brice DC, Castellaw AH, Mandarano AH, Guy CS, Mejia JR, Lewis CD, Chang TC, Oshansky CM, Wong SS, Webby RJ, Yan M, Li Q, Marion TN, Thomas PG, McGargill MA. Induction of broadly reactive influenza antibodies increases susceptibility to autoimmunity. Cell Rep 2022; 38:110482. [PMID: 35263574 PMCID: PMC9036619 DOI: 10.1016/j.celrep.2022.110482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 01/19/2022] [Accepted: 02/11/2022] [Indexed: 11/03/2022] Open
Abstract
Infection and vaccination repeatedly expose individuals to antigens that are conserved between influenza virus subtypes. Nevertheless, antibodies recognizing variable influenza epitopes greatly outnumber antibodies reactive against conserved epitopes. Elucidating factors contributing to the paucity of broadly reactive influenza antibodies remains a major obstacle for developing a universal influenza vaccine. Here, we report that inducing broadly reactive influenza antibodies increases autoreactive antibodies in humans and mice and exacerbates disease in four distinct models of autoimmune disease. Importantly, transferring broadly reactive influenza antibodies augments disease in the presence of inflammation or autoimmune susceptibility. Further, broadly reactive influenza antibodies spontaneously arise in mice with defects in B cell tolerance. Together, these data suggest that self-tolerance mechanisms limit the prevalence of broadly reactive influenza antibodies, which can exacerbate disease in the context of additional risk factors.
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Affiliation(s)
- Jocelyn G. Labombarde
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,These authors contributed equally
| | - Meenu R. Pillai
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,These authors contributed equally
| | - Marie Wehenkel
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,These authors contributed equally
| | - Chun-Yang Lin
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Rachael Keating
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Scott A. Brown
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Jeremy Chase Crawford
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - David C. Brice
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Ashley H. Castellaw
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | | | - Clifford S. Guy
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Juan R. Mejia
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Carlessia D. Lewis
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Ti-Cheng Chang
- Center for Applied Bioinformatics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Christine M. Oshansky
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Sook-San Wong
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Present address: Guangzhou Medical University, Xinzao, Panyu District, Guangzhou, P.R. China,Present address: State Key Laboratory of Respiratory Diseases & National Clinical Research Center for Respiratory Disease, Guangzhou, P.R. China,Present address: School of Public Health, The University of Hong Kong, Hong Kong SAR, P.R. China
| | - Richard J. Webby
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Mei Yan
- Department of Immunology and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Quan–Zhen Li
- Department of Immunology and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tony N. Marion
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Paul G. Thomas
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Maureen A. McGargill
- Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Lead contact,Correspondence:
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6
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Neumeier D, Pedrioli A, Genovese A, Sandu I, Ehling R, Hong KL, Papadopoulou C, Agrafiotis A, Kuhn R, Shlesinger D, Robbiani D, Han J, Hauri L, Csepregi L, Greiff V, Merkler D, Reddy ST, Oxenius A, Yermanos A. Profiling the specificity of clonally expanded plasma cells during chronic viral infection by single-cell analysis. Eur J Immunol 2021; 52:297-311. [PMID: 34727578 PMCID: PMC9299196 DOI: 10.1002/eji.202149331] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/02/2021] [Accepted: 10/29/2021] [Indexed: 12/12/2022]
Abstract
Plasma cells and their secreted antibodies play a central role in the long-term protection against chronic viral infection. However, due to experimental limitations, a comprehensive description of linked genotypic, phenotypic, and antibody repertoire features of plasma cells (gene expression, clonal frequency, virus specificity, and affinity) has been challenging to obtain. To address this, we performed single-cell transcriptome and antibody repertoire sequencing of the murine BM plasma cell population following chronic lymphocytic choriomeningitis virus infection. Our single-cell sequencing approach recovered full-length and paired heavy- and light-chain sequence information for thousands of plasma cells and enabled us to perform recombinant antibody expression and specificity screening. Antibody repertoire analysis revealed that, relative to protein immunization, chronic infection led to increased levels of clonal expansion, class-switching, and somatic variants. Furthermore, antibodies from the highly expanded and class-switched (IgG) plasma cells were found to be specific for multiple viral antigens and a subset of clones exhibited cross-reactivity to nonviral and autoantigens. Integrating single-cell transcriptome data with antibody specificity suggested that plasma cell transcriptional phenotype was correlated to viral antigen specificity. Our findings demonstrate that chronic viral infection can induce and sustain plasma cell clonal expansion, combined with significant somatic hypermutation, and can generate cross-reactive antibodies.
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Affiliation(s)
- Daniel Neumeier
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | | | - Ioana Sandu
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Roy Ehling
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Kai-Lin Hong
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Chrysa Papadopoulou
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Andreas Agrafiotis
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland.,Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Raphael Kuhn
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | - Damiano Robbiani
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Jiami Han
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Laura Hauri
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Lucia Csepregi
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Victor Greiff
- Department of Immunology, University of Oslo, Oslo, Norway
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland
| | - Sai T Reddy
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | - Alexander Yermanos
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland.,Institute of Microbiology, ETH Zurich, Zurich, Switzerland.,Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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7
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Rujas E, Leaman DP, Insausti S, Carravilla P, García-Porras M, Largo E, Morillo I, Sánchez-Eugenia R, Zhang L, Cui H, Iloro I, Elortza F, Julien JP, Eggeling C, Zwick MB, Caaveiro JM, Nieva JL. Focal accumulation of aromaticity at the CDRH3 loop mitigates 4E10 polyreactivity without altering its HIV neutralization profile. iScience 2021; 24:102987. [PMID: 34505005 PMCID: PMC8413895 DOI: 10.1016/j.isci.2021.102987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/08/2021] [Accepted: 08/12/2021] [Indexed: 11/29/2022] Open
Abstract
Broadly neutralizing antibodies (bnAbs) against HIV-1 are frequently associated with the presence of autoreactivity/polyreactivity, a property that can limit their use as therapeutic agents. The bnAb 4E10, targeting the conserved Membrane proximal external region (MPER) of HIV-1, displays almost pan-neutralizing activity across globally circulating HIV-1 strains but exhibits nonspecific off-target interactions with lipid membranes. The hydrophobic apex of the third complementarity-determining region of the heavy chain (CDRH3) loop, which is essential for viral neutralization, critically contributes to this detrimental effect. Here, we have replaced the aromatic/hydrophobic residues from the apex of the CDRH3 of 4E10 with a single aromatic molecule through chemical modification to generate a variant that preserves the neutralization potency and breadth of 4E10 but with reduced autoreactivity. Collectively, our study suggests that the localized accumulation of aromaticity by chemical modification provides a pathway to ameliorate the adverse effects triggered by the CDRH3 of anti-HIV-1 MPER bnAbs.
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Affiliation(s)
- Edurne Rujas
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Daniel P. Leaman
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sara Insausti
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Pablo Carravilla
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
- Institute of Applied Optics and Biophysics Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Miguel García-Porras
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Eneko Largo
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Izaskun Morillo
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Rubén Sánchez-Eugenia
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Lei Zhang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Hong Cui
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Ibon Iloro
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), CIBERehd, ProteoRed-ISCIII, Bizkaia Science and Technology Park, 48160 Derio, Spain
| | - Félix Elortza
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), CIBERehd, ProteoRed-ISCIII, Bizkaia Science and Technology Park, 48160 Derio, Spain
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Immunology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Christian Eggeling
- Institute of Applied Optics and Biophysics Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS Oxford, UK
| | - Michael B. Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jose M.M. Caaveiro
- Laboratory of Global Healthcare, School of Pharmaceutical Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - José L. Nieva
- Instituto Biofisika (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
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8
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Carravilla P, Darré L, Oar-Arteta IR, Vesga AG, Rujas E, de Las Heras-Martínez G, Domene C, Nieva JL, Requejo-Isidro J. The Bilayer Collective Properties Govern the Interaction of an HIV-1 Antibody with the Viral Membrane. Biophys J 2019; 118:44-56. [PMID: 31787208 DOI: 10.1016/j.bpj.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 01/15/2023] Open
Abstract
Efficient engagement with the envelope glycoprotein membrane-proximal external region (MPER) results in robust blocking of viral infection by a class of broadly neutralizing antibodies (bnAbs) against human immunodeficiency virus (HIV). Developing an accommodation surface that engages with the viral lipid envelope appears to correlate with the neutralizing potency displayed by these bnAbs. The nature of the interactions established between the antibody and the lipid is nonetheless a matter of debate, with some authors arguing that anti-MPER specificity arises only under pathological conditions in autoantibodies endowed with stereospecific binding sites for phospholipids. However, bnAb-lipid interactions are often studied in systems that do not fully preserve the biophysical properties of lipid bilayers, and therefore, questions on binding specificity and the effect of collective membrane properties on the interaction are still open. Here, to evaluate the specificity of lipid interactions of an anti-MPER bnAb (4E10) in an intact membrane context, we determine quantitatively its association with lipid bilayers by means of scanning fluorescence correlation spectroscopy and all-atom molecular dynamic simulations. Our data support that 4E10 establishes electrostatic and hydrophobic interactions with the viral membrane surface and that the collective physical properties of the lipid bilayer influence 4E10 dynamics therein. We conclude that establishment of peripheral, nonspecific electrostatic interactions with the viral membrane through accommodation surfaces may assist high-affinity binding of HIV-1 MPER epitope at membrane interfaces. These findings highlight the importance of considering antibody-lipid interactions in the design of antibody-based anti-HIV strategies.
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Affiliation(s)
- Pablo Carravilla
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain; Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Jena, Germany
| | - Leonardo Darré
- Functional Genomics Laboratory & Biomolecular Simulations Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Itziar R Oar-Arteta
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Arturo G Vesga
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Edurne Rujas
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | | | - Carmen Domene
- Department of Chemistry, University of Bath, Claverton Down, Bath, United Kingdom; Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Jose L Nieva
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
| | - Jose Requejo-Isidro
- Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain; Centro Nacional de Biotecnología, CSIC, Madrid, Spain; Unidad de Nanobiotecnología, CNB-CSIC-IMDEA Nanociencia Associated Unit, Madrid, Spain.
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9
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Longitudinal Analysis Reveals Early Development of Three MPER-Directed Neutralizing Antibody Lineages from an HIV-1-Infected Individual. Immunity 2019; 50:677-691.e13. [PMID: 30876875 DOI: 10.1016/j.immuni.2019.02.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/13/2018] [Accepted: 02/13/2019] [Indexed: 12/21/2022]
Abstract
Lineage-based vaccine design is an attractive approach for eliciting broadly neutralizing antibodies (bNAbs) against HIV-1. However, most bNAb lineages studied to date have features indicative of unusual recombination and/or development. From an individual in the prospective RV217 cohort, we identified three lineages of bNAbs targeting the membrane-proximal external region (MPER) of the HIV-1 envelope. Antibodies RV217-VRC42.01, -VRC43.01, and -VRC46.01 used distinct modes of recognition and neutralized 96%, 62%, and 30%, respectively, of a 208-strain virus panel. All three lineages had modest levels of somatic hypermutation and normal antibody-loop lengths and were initiated by the founder virus MPER. The broadest lineage, VRC42, was similar to the known bNAb 4E10. A multimeric immunogen based on the founder MPER activated B cells bearing the unmutated common ancestor of VRC42, with modest maturation of early VRC42 intermediates imparting neutralization breadth. These features suggest that VRC42 may be a promising template for lineage-based vaccine design.
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10
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Heger E, Schuetz A, Vasan S. HIV Vaccine Efficacy Trials: RV144 and Beyond. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1075:3-30. [PMID: 30030787 DOI: 10.1007/978-981-13-0484-2_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Despite progress in antiretroviral therapy, pre-exposure prophylaxis, microbicides, and other preventive strategies, a vaccine to prevent HIV-1 infection remains desperately needed. Development of an effective vaccine is challenged by several immunologic features of HIV-1 evidenced by the failure of five of the six HIV-1 candidate vaccine efficacy trials to date. This chapter reviews these efficacy trials with a focus on the Phase 3 RV144 trial in Thailand, the only HIV-1 vaccine efficacy trial to show a moderate protective effect of 31% with respect to placebo administration. Although modest, this protection has allowed for the study of potential immunologic correlates of protection to improve development of future HIV-1 pox-protein and other vaccine strategies. Trials in Thailand and South Africa have built upon the RV144 framework to provide additional immunologic insights which enable current and future efficacy testing of related vaccine candidates.
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Affiliation(s)
- Elizabeth Heger
- US Army Medical Materiel Development Activity, Fort Detrick, MD, USA
| | - Alexandra Schuetz
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
- Henry M. Jackson Foundation, Bethesda, MD, USA
| | - Sandhya Vasan
- US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
- Henry M. Jackson Foundation, Bethesda, MD, USA.
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11
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Falkenhagen A, Joshi S. HIV Entry and Its Inhibition by Bifunctional Antiviral Proteins. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 13:347-364. [PMID: 30340139 PMCID: PMC6197789 DOI: 10.1016/j.omtn.2018.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 12/14/2022]
Abstract
HIV entry is a highly specific and time-sensitive process that can be divided into receptor binding, coreceptor binding, and membrane fusion. Bifunctional antiviral proteins (bAVPs) exploit the multi-step nature of the HIV entry process by binding to two different extracellular targets. They are generated by expressing a fusion protein containing two entry inhibitors with a flexible linker. The resulting fusion proteins exhibit exceptional neutralization potency and broad cross-clade inhibition. In this review, we summarize the HIV entry process and provide an overview of the design, antiviral potency, and methods of delivery of bAVPs. Additionally, we discuss the advantages and limitations of bAVPs for HIV prevention and treatment.
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Affiliation(s)
- Alexander Falkenhagen
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Sadhna Joshi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E2, Canada.
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12
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Lipid interactions and angle of approach to the HIV-1 viral membrane of broadly neutralizing antibody 10E8: Insights for vaccine and therapeutic design. PLoS Pathog 2017; 13:e1006212. [PMID: 28225819 PMCID: PMC5338832 DOI: 10.1371/journal.ppat.1006212] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 03/06/2017] [Accepted: 02/02/2017] [Indexed: 01/26/2023] Open
Abstract
Among broadly neutralizing antibodies to HIV, 10E8 exhibits greater neutralizing breadth than most. Consequently, this antibody is the focus of prophylactic/therapeutic development. The 10E8 epitope has been identified as the conserved membrane proximal external region (MPER) of gp41 subunit of the envelope (Env) viral glycoprotein and is a major vaccine target. However, the MPER is proximal to the viral membrane and may be laterally inserted into the membrane in the Env prefusion form. Nevertheless, 10E8 has not been reported to have significant lipid-binding reactivity. Here we report x-ray structures of lipid complexes with 10E8 and a scaffolded MPER construct and mutagenesis studies that provide evidence that the 10E8 epitope is composed of both MPER and lipid. 10E8 engages lipids through a specific lipid head group interaction site and a basic and polar surface on the light chain. In the model that we constructed, the MPER would then be essentially perpendicular to the virion membrane during 10E8 neutralization of HIV-1. As the viral membrane likely also plays a role in selecting for the germline antibody as well as size and residue composition of MPER antibody complementarity determining regions, the identification of lipid interaction sites and the MPER orientation with regard to the viral membrane surface during 10E8 engagement can be of great utility for immunogen and therapeutic design. The trimeric Env glycoprotein located on HIV surface is the target of broadly neutralizing antibodies and is the focus of vaccine and therapeutic approaches to prevent HIV infection. Structural studies with HIV Env trimers have shed light on the complete epitopes of several broadly neutralizing antibodies. However, structural determination of the complete epitopes of the highly cross-reactive MPER antibodies has been technically difficult due to the viral membrane component and that these epitopes are probably only exposed transiently after Env engages CD4. In this study, we structurally characterize the interaction of the broadest and most potent MPER-targeting antibody, 10E8, with viral membrane lipids and scaffolded MPER and propose how 10E8 approaches the MPER-viral membrane epitope during neutralization. Our results indicate that 10E8 interacts with the viral membrane via its light chain and engages MPER in an upright orientation with respect to the HIV-1 membrane. These findings are of interest for design of HIV-1 vaccines and therapeutics.
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13
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Rujas E, Caaveiro JMM, Insausti S, García-Porras M, Tsumoto K, Nieva JL. Peripheral Membrane Interactions Boost the Engagement by an Anti-HIV-1 Broadly Neutralizing Antibody. J Biol Chem 2017; 292:5571-5583. [PMID: 28213514 DOI: 10.1074/jbc.m117.775429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/16/2017] [Indexed: 12/16/2022] Open
Abstract
The 4E10 antibody displays an extreme breadth of HIV-1 neutralization and therefore constitutes a suitable model system for structure-guided vaccine design and immunotherapeutics against AIDS. In this regard, the relevance of autoreactivity with membrane lipids for the biological function of this antibody is still a subject of controversy. To address this dispute, herein we have compared the membrane partitioning ability of the 4E10 antibody and several of its variants, which were mutated at the region of the paratope surface in contact with the membrane interface. We first employed a physical separation approach (vesicle flotation) and subsequently carried out quantitative fluorescence measurements in an intact system (spectroscopic titration), using 4E10 Fab labeled with a polarity-sensitive fluorescent probe. Moreover, recognition of epitope peptide in membrane was demonstrated by photo-cross-linking assays using a Fab that incorporated the genetically encoded unnatural amino acid p-benzoylphenylalanine. The experimental data ruled out that the proposed stereospecific recognition of viral lipids was necessary for the function of the antibody. In contrast, our data suggest that nonspecific electrostatic interactions between basic residues of 4E10 and acidic phospholipids in the membranes contribute to the observed biological function. Moreover, the energetics of membrane partitioning indicated that 4E10 behaves as a peripheral membrane protein, tightening the binding to the ligand epitope inserted in the viral membrane. The implications of these findings for the natural production and biological function of this antibody are discussed.
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Affiliation(s)
- Edurne Rujas
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and.,the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, 113-8656, Japan
| | - José M M Caaveiro
- the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, 113-8656, Japan
| | - Sara Insausti
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and
| | - Miguel García-Porras
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and
| | - Kouhei Tsumoto
- the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, 113-8656, Japan
| | - José L Nieva
- From the Biofisika Institute (Consejo Superior de Investigaciones Científicas, UPV/EHU), and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain and
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14
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Trifunctional lipid probes for comprehensive studies of single lipid species in living cells. Proc Natl Acad Sci U S A 2017; 114:1566-1571. [PMID: 28154130 DOI: 10.1073/pnas.1611096114] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Lipid-mediated signaling events regulate many cellular processes. Investigations of the complex underlying mechanisms are difficult because several different methods need to be used under varying conditions. Here we introduce multifunctional lipid derivatives to study lipid metabolism, lipid-protein interactions, and intracellular lipid localization with a single tool per target lipid. The probes are equipped with two photoreactive groups to allow photoliberation (uncaging) and photo-cross-linking in a sequential manner, as well as a click-handle for subsequent functionalization. We demonstrate the versatility of the design for the signaling lipids sphingosine and diacylglycerol; uncaging of the probe for these two species triggered calcium signaling and intracellular protein translocation events, respectively. We performed proteomic screens to map the lipid-interacting proteome for both lipids. Finally, we visualized a sphingosine transport deficiency in patient-derived Niemann-Pick disease type C fibroblasts by fluorescence as well as correlative light and electron microscopy, pointing toward the diagnostic potential of such tools. We envision that this type of probe will become important for analyzing and ultimately understanding lipid signaling events in a comprehensive manner.
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Abstract
Purpose of review This review highlights recent developments in HIV-1 antibody engineering and discusses the effects of increased polyreactivity on serum half-lives of engineered antibodies. Recent findings Recent studies have uncovered a wealth of information about the relationship between the sequences and efficacies of anti-HIV-1 antibodies through a combination of bioinformatics, structural characterization and in vivo studies. This knowledge has stimulated efforts to enhance antibody breadth and potency for therapeutic use. Although some engineered antibodies have shown increased polyreactivity and short half-lives, promising efforts are circumventing these problems. Summary Antibodies are desirable as therapeutics due to their ability to recognize targets with both specificity and high affinity. Furthermore, the ability of antibodies to stimulate Fc-mediated effector functions can increase their utility. Thus, mAbs have become central to strategies for the treatment of various diseases. Using both targeted and library-based approaches, antibodies can be engineered to improve their therapeutic properties. This article will discuss recent antibody engineering efforts to improve the breadth and potency of anti-HIV-1 antibodies. The polyreactivity of engineered HIV-1 bNAbs and the effect on serum half-life will be explored along with strategies to overcome problems introduced by engineering antibodies. Finally, advances in creating bispecific anti-HIV-1 reagents are discussed.
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16
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Irimia A, Sarkar A, Stanfield RL, Wilson IA. Crystallographic Identification of Lipid as an Integral Component of the Epitope of HIV Broadly Neutralizing Antibody 4E10. Immunity 2016; 44:21-31. [PMID: 26777395 DOI: 10.1016/j.immuni.2015.12.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 01/24/2023]
Abstract
Numerous studies of the anti-HIV-1 envelope glycoprotein 41 (gp41) broadly neutralizing antibody 4E10 suggest that 4E10 also interacts with membrane lipids, but the antibody regions contacting lipids and its orientation with respect to the viral membrane are unknown. Vaccine immunogens capable of re-eliciting these membrane proximal external region (MPER)-like antibodies may require a lipid component to be successful. We performed a systematic crystallographic study of lipid binding to 4E10 to identify lipids bound by the antibody and the lipid-interacting regions. We identified phosphatidic acid, phosphatidylglycerol, and glycerol phosphate as specific ligands for 4E10 in the crystal structures. 4E10 used its CDRH1 loop to bind the lipid head groups, while its CDRH3 interacted with the hydrophobic lipid tails. Identification of the lipid binding sites on 4E10 may aid design of immunogens for vaccines that include a lipid component in addition to the MPER on gp41 for generation of broadly neutralizing antibodies.
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Affiliation(s)
- Adriana Irimia
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Anita Sarkar
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA.
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17
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Cappelletti F, Clementi N, Mancini N, Clementi M, Burioni R. Virus-induced preferential antibody gene-usage and its importance in humoral autoimmunity. Semin Immunol 2015; 27:138-43. [PMID: 25857210 DOI: 10.1016/j.smim.2015.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/13/2015] [Indexed: 12/12/2022]
Abstract
It is known that even the adaptive components of the immune system are based on genetic traits common to all individuals, and that diversity is shaped by the lifelong contacts with different non-self antigens, including those found on infectious pathogens. Besides the individual differences, some of these common traits may be more prone to react against a given antigen, and this may be exploited by the infectious pathogens. Indeed, viral infections can deregulate immune response by subverting antibody (Ab) gene usage, leading to the overexpression of specific Ab subfamilies. This overexpression often results in a protective antiviral response but, in some cases, also correlates with a higher likelihood of developing humoral autoimmune disorders. These aspects of virus-induced autoimmunity have never been thoroughly reviewed, and this is the main purpose of this review. An accurate examination of virus specific Ab subfamilies elicited during infections may help further characterize the complex interplay between viruses and the humoral immune response, and be useful in the design of future monoclonal antibody (mAb)-based anti-infective prophylactic and therapeutic strategies.
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Affiliation(s)
- Francesca Cappelletti
- Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Milano, Italy
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Milano, Italy
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Milano, Italy
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Milano, Italy
| | - Roberto Burioni
- Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Milano, Italy.
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18
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Figueira TN, Veiga AS, Castanho MA. The interaction of antibodies with lipid membranes unraveled by fluorescence methodologies. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.02.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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19
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Bird GH, Irimia A, Ofek G, Kwong PD, Wilson IA, Walensky LD. Stapled HIV-1 peptides recapitulate antigenic structures and engage broadly neutralizing antibodies. Nat Struct Mol Biol 2014; 21:1058-67. [PMID: 25420104 PMCID: PMC4304871 DOI: 10.1038/nsmb.2922] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 10/23/2014] [Indexed: 01/28/2023]
Abstract
Hydrocarbon stapling can restore bioactive α-helical structure to natural peptides, yielding research tools and prototype therapeutics to dissect and target protein interactions. Here we explore the capacity of peptide stapling to generate high-fidelity, protease-resistant mimics of antigenic structures for vaccine development. HIV-1 has been refractory to vaccine technologies thus far, although select human antibodies can broadly neutralize HIV-1 by targeting sequences of the gp41 juxtamembrane fusion apparatus. To develop candidate HIV-1 immunogens, we generated and characterized stabilized α-helices of the membrane-proximal external region (SAH-MPER) of gp41. SAH-MPER peptides were remarkably protease resistant and bound to the broadly neutralizing 4E10 and 10E8 antibodies with high affinity, recapitulating the structure of the MPER epitope when differentially engaged by the two anti-HIV Fabs. Thus, stapled peptides may provide a new opportunity to develop chemically stabilized antigens for vaccination.
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Affiliation(s)
- Gregory H. Bird
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Adriana Irimia
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
- Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, USA
| | - Gilad Ofek
- Vaccine Research Center, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter D. Kwong
- Vaccine Research Center, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
- Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA, USA
| | - Loren D. Walensky
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Hematology/Oncology, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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20
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Stieh DJ, King DF, Klein K, Liu P, Shen X, Hwang KK, Ferrari G, Montefiori DC, Haynes B, Pitisuttithum P, Kaewkungwal J, Nitayaphan S, Rerks-Ngarm S, Michael NL, Robb ML, Kim JH, Denny TN, Tomaras GD, Shattock RJ. Aggregate complexes of HIV-1 induced by multimeric antibodies. Retrovirology 2014; 11:78. [PMID: 25274446 PMCID: PMC4193994 DOI: 10.1186/s12977-014-0078-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 08/30/2014] [Indexed: 11/10/2022] Open
Abstract
Background Antibody mediated viral aggregation may impede viral transfer across mucosal surfaces by hindering viral movement in mucus, preventing transcytosis, or reducing inter-cellular penetration of epithelia thereby limiting access to susceptible mucosal CD4 T cells and dendritic cells. These functions may work together to provide effective immune exclusion of virus from mucosal tissue; however little is known about the antibody characteristics required to induce HIV aggregation. Such knowledge may be critical to the design of successful immunization strategies to facilitate viral immune exclusion at the mucosal portals of entry. Results The potential of neutralizing and non-neutralizing IgG and IgA monoclonals (mAbs) to induce HIV-1 aggregation was assessed by Dynamic light scattering (DLS). Although neutralizing and non-neutralizing IgG mAbs and polyclonal HIV-Ig efficiently aggregated soluble Env trimers, they were not capable of forming viral aggregates. In contrast, dimeric (but not monomeric) IgA mAbs induced stable viral aggregate populations that could be separated from uncomplexed virions. Epitope specificity influenced both the degree of aggregation and formation of higher order complexes by dIgA. IgA purified from serum of uninfected RV144 vaccine trial responders were able to efficiently opsonize viral particles in the absence of significant aggregation, reflective of monomeric IgA. Conclusions These results collectively demonstrate that dIgA is capable of forming stable viral aggregates providing a plausible basis for testing the effectiveness of aggregation as a potential protection mechanism at the mucosal portals of viral entry. Electronic supplementary material The online version of this article (doi:10.1186/s12977-014-0078-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel J Stieh
- Center for Infection, Department of Cellular and Molecular Medicine, St George's, University of London, London, SW17 0RE, UK. .,Current address: Department of Cellular and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA.
| | - Deborah F King
- Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, St Mary's Campus, London, W2 1PG, UK.
| | - Katja Klein
- Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, St Mary's Campus, London, W2 1PG, UK.
| | - Pinghuang Liu
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA. .,Current address: Division of Swine Infectious Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Xiaoying Shen
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Kwan Ki Hwang
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Guido Ferrari
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | - David C Montefiori
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Barton Haynes
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | | | | | | | | | - Nelson L Michael
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America.
| | - Merlin L Robb
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America.
| | - Jerome H Kim
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America.
| | - Thomas N Denny
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Georgia D Tomaras
- Duke Human Vaccine Center, Duke University Medical Center, Durham, NC, 27710, USA.
| | - Robin J Shattock
- Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, St Mary's Campus, London, W2 1PG, UK.
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21
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Sims KH, Tytler EM, Tipton J, Hill KL, Burgess SW, Shaw WA. Avanti lipid tools: connecting lipids, technology, and cell biology. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1038-48. [PMID: 24954118 DOI: 10.1016/j.bbalip.2014.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 11/15/2022]
Abstract
Lipid research is challenging owing to the complexity and diversity of the lipidome. Here we review a set of experimental tools developed for the seasoned lipid researcher, as well as, those who are new to the field of lipid research. Novel tools for probing protein-lipid interactions, applications for lipid binding antibodies, enhanced systems for the cellular delivery of lipids, improved visualization of lipid membranes using gold-labeled lipids, and advances in mass spectrometric analysis techniques will be discussed. Because lipid mediators are known to participate in a host of signal transduction and trafficking pathways within the cell, a comprehensive lipid toolbox that aids the science of lipidomics research is essential to better understand the molecular mechanisms of interactions between cellular components. This article is part of a Special Issue entitled Tools to study lipid functions.
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Affiliation(s)
- Kacee H Sims
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, Al 35007, USA.
| | - Ewan M Tytler
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, Al 35007, USA.
| | - John Tipton
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, Al 35007, USA.
| | - Kasey L Hill
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, Al 35007, USA.
| | - Stephen W Burgess
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, Al 35007, USA.
| | - Walter A Shaw
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, Al 35007, USA.
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Chemically modified peptides based on the membrane-proximal external region of the HIV-1 envelope induce high-titer, epitope-specific nonneutralizing antibodies in rabbits. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1086-93. [PMID: 24872518 DOI: 10.1128/cvi.00320-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Broadly neutralizing monoclonal antibodies (bNAbs) 2F5 and 4E10 bind to the membrane proximal external region (MPER) of gp41 and also cross-react with phospholipids. In this study, we investigated if chemical modifications on the MPER adjacent to 2F5 and 4E10 epitopes using mimetics of inflammation-associated posttranslational modifications to induce 2F5- and 4E10-like bNAbs can break tolerance. We synthesized a series of chemically modified peptides spanning the MPER. The serine, threonine, and tyrosine residues in the peptides were modified with sulfate, phosphate, or nitrate moieties and presented in liposomes for rabbit immunizations. All immunizations resulted in high antisera titers directed toward both the modified and unmodified immunogens. Tyrosine modification was observed to significantly suppress antiepitope responses. Sera with strong anti-gp140 titers were purified by affinity chromatography toward the MPER peptide and found to possess a higher affinity toward the MPER than did the bNAbs 2F5 and 4E10. Modest neutralization was observed in the H9 neutralization assay, but neutralization was not observed in the TZM-bl cell or peripheral blood mononuclear cell (PBMC) neutralization assay platforms. Although neutralizing antibodies were not induced by this approach, we conclude that chemical modifications can increase the immune responses to poorly immunogenic antigens, suggesting that chemical modification in an appropriate immunization protocol should be explored further as an HIV-1 vaccine strategy.
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Strasz N, Morozov VA, Kreutzberger J, Keller M, Eschricht M, Denner J. Immunization with hybrid proteins containing the membrane proximal external region of HIV-1. AIDS Res Hum Retroviruses 2014; 30:498-508. [PMID: 24392780 DOI: 10.1089/aid.2013.0191] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The transmembrane envelope (TM) protein gp41 of HIV-1 is an attractive target when designing a vaccine to induce neutralizing antibodies. A few broadly neutralizing antibodies (2F5, 4E10, and 10E8) that target conserved epitopes in the membrane proximal external region (MPER) of gp41 have been isolated from infected individuals. However, attempts to induce such antibodies by immunizations with gp41 and Env derivatives containing the MPER were successful only to some extent. In contrast, immunizations with the ectodomain of the TM protein p15E of different gamma retroviruses resulted in the induction of neutralizing antibodies. These sera recognized epitopes located in the MPER and in the fusion peptide proximal region (FPPR) of p15E. Based on these results, both regions of p15E were substituted with the corresponding sequences derived from gp41 of HIV-1. Thus, four different hybrid antigens were produced. One of the inserted sequences contained the epitopes of 2F5 and 4E10 in the MPER; the other corresponded to the FPPR. Vaccination of rats, guinea pigs, and a goat induced binding antibodies directed against the FPPR of gp41 and the 2F5 epitope (ELDKWA) located in the MPER. Despite the exact recognition of the 2F5 epitope, no or very weak neutralization of HIV-1NL4-3 by the immune sera was demonstrated. Nonetheless, using the strategy of hybrid proteins, antibodies targeting the desired epitope were successfully induced.
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Abstract
Vaccines to prevent HIV remain desperately needed, but a number of challenges, including retroviral integration, establishment of anatomic reservoir sites, high sequence diversity, and heavy envelope glycosylation. have precluded development of a highly effective vaccine. DNA vaccines have been utilized as candidate HIV vaccines because of their ability to generate cellular and humoral immune responses, the lack of anti-vector response allowing for repeat administration, and their ability to prime the response to viral-vectored vaccines. Because the HIV epidemic has disproportionately affected the developing world, the favorable thermostability profile and relative ease and low cost of manufacture of DNA vaccines offer additional advantages. In vivo electroporation (EP) has been utilized to improve immune responses to DNA vaccines as candidate HIV-1 vaccines in standalone or prime-boost regimens with both proteins and viral-vectored vaccines in several animal models and, more recently, in human clinical trials. This chapter describes the preclinical and clinical development of candidate DNA vaccines for HIV-1 delivered by EP, including challenges to bringing this technology to the developing world.
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Affiliation(s)
- Sandhya Vasan
- Department of Retrovirology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
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25
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Campbell CT, Llewellyn SR, Damberg T, Morgan IL, Robert-Guroff M, Gildersleeve JC. High-throughput profiling of anti-glycan humoral responses to SIV vaccination and challenge. PLoS One 2013; 8:e75302. [PMID: 24086502 PMCID: PMC3781036 DOI: 10.1371/journal.pone.0075302] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/13/2013] [Indexed: 11/18/2022] Open
Abstract
Recent progress toward an HIV vaccine highlights both the potential of vaccines to end the AIDS pandemic and the need to boost efficacy by incorporating additional vaccine strategies. Although many aspects of the immune response can contribute to vaccine efficacy, the key factors have not been defined fully yet. A particular area that may yield new insights is anti-glycan immune responses, such as those against the glycan shield that HIV uses to evade the immune system. In this study, we used glycan microarray technology to evaluate anti-glycan antibody responses induced by SIV vaccination and infection in a non-human primate model of HIV infection. This comprehensive profiling of circulating anti-glycan antibodies found changes in anti-glycan antibody levels after both vaccination with the Ad5hr-SIV vaccine and SIV infection. Notably, SIV infection produced generalized declines in anti-glycan IgM antibodies in a number of animals. Additionally, some infected animals generated antibodies to the Tn antigen, which is a cryptic tumor-associated antigen exposed by premature termination of O-linked glycans; however, the Ad5hr-SIV vaccine did not induce anti-Tn IgG antibodies. Overall, this study demonstrates the potential contributions that glycan microarrays can make for HIV vaccine development.
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Affiliation(s)
- Christopher T. Campbell
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
| | - Sean R. Llewellyn
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
| | - Thorsten Damberg
- Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ian L. Morgan
- Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Marjorie Robert-Guroff
- Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (JCG); (MR)
| | - Jeffrey C. Gildersleeve
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
- * E-mail: (JCG); (MR)
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26
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Yang G, Holl TM, Liu Y, Li Y, Lu X, Nicely NI, Kepler TB, Alam SM, Liao HX, Cain DW, Spicer L, VandeBerg JL, Haynes BF, Kelsoe G. Identification of autoantigens recognized by the 2F5 and 4E10 broadly neutralizing HIV-1 antibodies. ACTA ACUST UNITED AC 2013; 210:241-56. [PMID: 23359068 PMCID: PMC3570098 DOI: 10.1084/jem.20121977] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Many human monoclonal antibodies that neutralize multiple clades of HIV-1 are polyreactive and bind avidly to mammalian autoantigens. Indeed, the generation of neutralizing antibodies to the 2F5 and 4E10 epitopes of HIV-1 gp41 in man may be proscribed by immune tolerance because mice expressing the V(H) and V(L) regions of 2F5 have a block in B cell development that is characteristic of central tolerance. This developmental blockade implies the presence of tolerizing autoantigens that are mimicked by the membrane-proximal external region of HIV-1 gp41. We identify human kynureninase (KYNU) and splicing factor 3b subunit 3 (SF3B3) as the primary conserved, vertebrate self-antigens recognized by the 2F5 and 4E10 antibodies, respectively. 2F5 binds the H4 domain of KYNU which contains the complete 2F5 linear epitope (ELDKWA). 4E10 recognizes an epitope of SF3B3 that is strongly dependent on hydrophobic interactions. Opossums carry a rare KYNU H4 domain that abolishes 2F5 binding, but they retain the SF3B3 4E10 epitope. Immunization of opossums with HIV-1 gp140 induced extraordinary titers of serum antibody to the 2F5 ELDKWA epitope but little or nothing to the 4E10 determinant. Identification of structural motifs shared by vertebrates and HIV-1 provides direct evidence that immunological tolerance can impair humoral responses to HIV-1.
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Affiliation(s)
- Guang Yang
- Department of Immunology, Duke University, Durham, NC 27705, USA
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The Enigmatic Role of Sulfatides: New Insights into Cellular Functions and Mechanisms of Protein Recognition. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 991:27-40. [DOI: 10.1007/978-94-007-6331-9_3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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28
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Huarte N, Araujo A, Arranz R, Lorizate M, Quendler H, Kunert R, Valpuesta JM, Nieva JL. Recognition of membrane-bound fusion-peptide/MPER complexes by the HIV-1 neutralizing 2F5 antibody: implications for anti-2F5 immunogenicity. PLoS One 2012; 7:e52740. [PMID: 23285173 PMCID: PMC3528738 DOI: 10.1371/journal.pone.0052740] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 11/21/2012] [Indexed: 11/19/2022] Open
Abstract
The membrane proximal external region (MPER) of the fusogenic HIV-1 glycoprotein-41 harbors the epitope sequence recognized by 2F5, a broadly neutralizing antibody isolated from an infected individual. Structural mimicry of the conserved MPER 2F5 epitope constitutes a pursued goal in the field of anti-HIV vaccine development. It has been proposed that 2F5 epitope folding into its native state is attained in the vicinity of the membrane interface and might involve interactions with other viral structures. Here we present results indicating that oligomeric complexes established between MPER and the conserved amino-terminal fusion peptide (FP) can partition into lipid vesicles and be specifically bound by the 2F5 antibody at their surfaces. Cryo-transmission electron microscopy of liposomes doped with MPER:FP peptide mixtures provided the structural grounds for complex recognition by antibody at lipid bilayer surfaces. Supporting the immunogenicity of the membrane-bound complex, these MPER:FP peptide-vesicle formulations could trigger cross-reactive anti-MPER antibodies in rabbits. Thus, our observations suggest that contacts with N-terminal regions of gp41 may stabilize the 2F5 epitope as a membrane-surface antigen.
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Affiliation(s)
- Nerea Huarte
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Aitziber Araujo
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Rocio Arranz
- Department of Macromolecular Structures, National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - Maier Lorizate
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Heribert Quendler
- Institute of Applied Microbiology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Renate Kunert
- Institute of Applied Microbiology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - José M. Valpuesta
- Department of Macromolecular Structures, National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - José L. Nieva
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), Bilbao, Spain
- * E-mail:
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29
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Rational design of membrane proximal external region lipopeptides containing chemical modifications for HIV-1 vaccination. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 20:39-45. [PMID: 23114698 DOI: 10.1128/cvi.00615-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The inability to generate broadly neutralizing antibody (bnAb) responses to the membrane proximal external region (MPER) of HIV-1 gp41 using current vaccine strategies has hampered efforts to prevent the spread of HIV. To address this challenge, we investigated a novel hypothesis to help improve the anti-MPER antibody response. Guided by structural insights and the unique lipid reactivity of anti-MPER bnAbs, we considered whether amino acid side chain modifications that emulate hydrophilic phospholipid head groups could contribute to the generation of 2F5-like or 4E10-like neutralizing anti-MPER antibodies. To test this hypothesis, we generated a series of chemically modified MPER immunogens through derivatization of amino acid side chains with phosphate or nitrate groups. We evaluated the binding affinity of the chemically modified peptides to their cognate monoclonal antibodies, 2F5 and 4E10, using surface plasmon resonance. The modifications had little effect on binding to the antibodies and did not influence epitope secondary structure when presented in liposomes. We selected five of the chemically modified sequences to immunize rabbits and found that an immunogen containing both the 2F5 and 4E10 epitopes and a phosphorylated threonine at T676 elicited the highest anti-peptide IgG titers, although the high antipeptide titers did not confer higher neutralizing activity. These data indicate that side chain modifications adjacent to known neutralizing antibody epitopes are capable of eliciting antibody responses to the MPER but that these chemically modified gp41 epitopes do not induce neutralizing antibodies.
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30
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Garg H, Viard M, Jacobs A, Blumenthal R. Targeting HIV-1 gp41-induced fusion and pathogenesis for anti-viral therapy. Curr Top Med Chem 2012; 11:2947-58. [PMID: 22044225 DOI: 10.2174/156802611798808479] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 02/28/2011] [Accepted: 12/01/2011] [Indexed: 11/22/2022]
Abstract
HIV gp41 is a metastable protein whose native conformation is maintained in the form of a heterodimer with gp120. The non-covalently associated gp41/gp120 complex forms a trimer on the virus surface. As gp120 engages with HIV's receptor, CD4, and coreceptor, CXCR4 or CCR5, gp41 undergoes several conformational changes resulting in fusion between the viral and cellular membranes. Several lipophilic and amphiphilic domains have been shown to be critical in that process. While the obvious function of gp41 in viral entry is well-established its role in cellular membrane fusion and the link with pathogenesis are only now beginning to appear. Recent targeting of gp41 via fusion inhibitors has revealed an important role of this protein not only in viral entry but also in bystander apoptosis and HIV pathogenesis. Studies by our group and others have shown that the phenomenon of gp41-mediated hemifusion initiates apoptosis in bystander cells and correlates with virus pathogenesis. More interestingly, recent clinical evidence suggests that gp41 mutants arising after Enfuvirtide therapy are associated with CD4 cell increase and immunological benefits. This has in turn been correlated to a decrease in bystander apoptosis in our in vitro as well as in vivo assays. Although a great deal of work has been done to unravel HIV-1 gp41-mediated fusion mechanisms, the factors that regulate gp41-mediated fusion versus hemifusion and the mechanism by which hemifusion initiates bystander apoptosis are not fully understood. Further insight into these issues will open new avenues for drug development making gp41 a critical anti-HIV target both for neutralization and virus attenuation.
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Affiliation(s)
- Himanshu Garg
- Center of Excellence for Infectious Disease, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA
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31
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An anti-phosphoinositide-specific monoclonal antibody that neutralizes HIV-1 infection of human monocyte-derived macrophages. Virology 2012; 430:110-9. [PMID: 22633000 DOI: 10.1016/j.virol.2012.04.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 04/12/2012] [Accepted: 04/24/2012] [Indexed: 11/20/2022]
Abstract
HIV-1 entry into cells requires the interaction of both HIV-1 envelope proteins and membrane lipids. We investigated the mechanism of neutralization of HIV-1 infection of primary monocyte-derived macrophages (MDM) by a murine monoclonal antibody (mAb) WR321. WR321 specifically binds phosphatidylinositol-4-phosphate and phosphatidylinositol-4,5-bisphosphate. These phosphoinositides are present not only on the inner surface of the plasma membranes of cells but also on the surface of virions. HIV-1 acquires these lipids during the budding process. Pre-incubation of WR321 with the virus but not with MDM neutralized HIV-1 infection of MDM. Our results demonstrate that WR321 was internalized only when it was bound to HIV-1. WR321 did not prevent the entry of HIV-1 into MDM. However, once WR321 was internalized along with HIV-1 the mAb acted intracellulary to prevent the release of virions from MDM and also triggered the release of β-chemokines.
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32
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Vasan S, Michael NL. Improved outlook on HIV-1 prevention and vaccine development. Expert Opin Biol Ther 2012; 12:983-94. [DOI: 10.1517/14712598.2012.688020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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33
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Design and characterization of a peptide mimotope of the HIV-1 gp120 bridging sheet. Int J Mol Sci 2012; 13:5674-5699. [PMID: 22754323 PMCID: PMC3382813 DOI: 10.3390/ijms13055674] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 04/26/2012] [Accepted: 05/02/2012] [Indexed: 01/02/2023] Open
Abstract
The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV(+) broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env). In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine.
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Mouquet H, Nussenzweig MC. Polyreactive antibodies in adaptive immune responses to viruses. Cell Mol Life Sci 2012; 69:1435-45. [PMID: 22045557 PMCID: PMC11114792 DOI: 10.1007/s00018-011-0872-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 01/15/2023]
Abstract
B cells express immunoglobulins on their surface where they serve as antigen receptors. When secreted as antibodies, the same molecules are key elements of the humoral immune response against pathogens such as viruses. Although most antibodies are restricted to binding a specific antigen, some are polyreactive and have the ability to bind to several different ligands, usually with low affinity. Highly polyreactive antibodies are removed from the repertoire during B-cell development by physiologic tolerance mechanisms including deletion and receptor editing. However, a low level of antibody polyreactivity is tolerated and can confer additional binding properties to pathogen-specific antibodies. For example, high-affinity human antibodies to HIV are frequently polyreactive. Here we review the evidence suggesting that in the case of some pathogens like HIV, polyreactivity may confer a selective advantage to pathogen-specific antibodies.
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Affiliation(s)
- Hugo Mouquet
- Laboratory of Molecular Immunology, The Rockefeller University, New York City, NY 10021, USA.
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35
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Chen W, Dimitrov DS. Monoclonal antibody-based candidate therapeutics against HIV type 1. AIDS Res Hum Retroviruses 2012; 28:425-34. [PMID: 21827278 DOI: 10.1089/aid.2011.0226] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Treatment of HIV-1 infection has been highly successful with small molecule drugs. However, resistance still develops. In addition, long-term use can lead to toxicity with unpredictable effects on health. Finally, current drugs do not lead to HIV-1 eradication. The presence of the virus leads to chronic inflammation, which can result in increased morbidity and mortality after prolonged periods of infection. Monoclonal antibodies (mAbs) have been highly successful during the past two decades for therapy of many diseases, primarily cancers and immune disorders. They are relatively safe, especially human mAbs that have evolved in humans at high concentrations to fight diseases and long-term use may not lead to toxicities. Several broadly neutralizing mAbs (bnmAbs) against HIV-1 can protect animals but are not effective when used for therapy of an established infection. We have hypothesized that HIV-1 has evolved strategies to effectively escape neutralization by full-size antibodies in natural infections but not by smaller antibody fragments. Therefore, a promising direction of research is to discover and exploit antibody fragments as potential candidate therapeutics against HIV-1. Here we review several bnmAbs and engineered antibody domains (eAds), their in vitro and in vivo antiviral efficacy, mechanisms used by HIV-1 to escape them, and strategies that could be effective to develop more powerful mAb-based HIV-1 therapeutics.
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Affiliation(s)
- Weizao Chen
- Protein Interactions Group, Center for Cancer Research Nanobiology Program, National Cancer Institute (NCI)-Frederick, National Institutes of Health (NIH), Frederick, Maryland
| | - Dimiter S. Dimitrov
- Protein Interactions Group, Center for Cancer Research Nanobiology Program, National Cancer Institute (NCI)-Frederick, National Institutes of Health (NIH), Frederick, Maryland
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36
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Neutralizing epitopes in the membrane-proximal external region of HIV-1 gp41 are influenced by the transmembrane domain and the plasma membrane. J Virol 2012; 86:2930-41. [PMID: 22238313 DOI: 10.1128/jvi.06349-11] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Failure to elicit broadly neutralizing (bNt) antibodies (Abs) against the membrane-proximal external region of HIV-1 gp41 (MPER) reflects the difficulty of mimicking its neutralization-competent structure (NCS). Here, we analyzed MPER antigenicity in the context of the plasma membrane and identified a role for the gp41 transmembrane domain (TM) in exposing the epitopes of three bNt monoclonal Abs (MAbs) (2F5, 4E10, and Z13e1). We transiently expressed DNA constructs encoding gp41 ectodomain fragments fused to either the TM of the platelet-derived growth factor receptor (PDGFR) or the gp41 TM and cytoplasmic tail domain (CT). Constructs encoding the MPER tethered to the gp41 TM followed by a 27-residue CT fragment (MPER-TM1) produced optimal MAb binding. Critical binding residues for the three Nt MAbs were identified using a panel of 24 MPER-TM1 mutants bearing single amino acid substitutions in the MPER; many were previously shown to affect MAb-mediated viral neutralization. Moreover, non-Nt mutants of MAbs 2F5 and 4E10 exhibited a reduction in binding to MPER-TM1 and yet maintained binding to synthetic MPER peptides, indicating that MPER-TM1 better approximates the MPER NCS than peptides. Replacement of the gp41 TM and CT of MPER-TM1 with the PDGFR TM reduced binding by MAb 4E10, but not 2F5, indicating that the gp41 TM plays a pivotal role in orienting the 4E10 epitope, and more globally, in affecting MPER exposure.
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37
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Binding of anti-membrane-proximal gp41 monoclonal antibodies to CD4-liganded and -unliganded human immunodeficiency virus type 1 and simian immunodeficiency virus virions. J Virol 2011; 86:1820-31. [PMID: 22090143 DOI: 10.1128/jvi.05489-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The broadly neutralizing monoclonal antibodies (MAbs) 4E10, 2F5, and Z13e1 target membrane-proximal external region (MPER) epitopes of HIV-1 gp41 in a manner that remains controversial. The requirements for initial lipid bilayer binding and/or CD4 ligation have been proposed. To further investigate these issues, we probed for binding of these MAbs to human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) virions with protein A-conjugated gold (PAG) nanoparticles using negative-stain electron microscopy. We found moderate levels of PAG associated with unliganded HIV-1 and SIV virions incubated with the three MAbs. Significantly higher levels of PAG were associated with CD4-liganded HIV-1 (epitope-positive) but not SIV (epitope-negative) virions. A chimeric SIV virion displaying the HIV-1 4E10 epitope also showed significantly higher PAG association after CD4 ligation and incubation with 4E10. MAbs accumulated rapidly on CD4-liganded virions and slowly on unliganded virions, although both reached similar levels in time. Anti-MPER epitope-specific binding was stable to washout. Virions incubated with an irrelevant MAb or CD4-only (no MAb) showed negligible PAG association, as did a vesicle-rich fraction devoid of virions. Preincubation with Fab 4E10 inhibited both specific and nonspecific 4E10 IgG binding. Our data provide evidence for moderate association of anti-MPER MAbs to viral surfaces but not lipid vesicles, even in the absence of cognate epitopes. Significantly greater MAb interaction occurs in epitope-positive virions following long incubation or CD4 ligation. These findings are consistent with a two-stage binding model where these anti-MPER MAbs bind first to the viral lipid bilayer and then to the MPER epitopes following spontaneous or induced exposure.
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38
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Mouquet H, Klein F, Scheid JF, Warncke M, Pietzsch J, Oliveira TYK, Velinzon K, Seaman MS, Nussenzweig MC. Memory B cell antibodies to HIV-1 gp140 cloned from individuals infected with clade A and B viruses. PLoS One 2011; 6:e24078. [PMID: 21931643 PMCID: PMC3169578 DOI: 10.1371/journal.pone.0024078] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 07/29/2011] [Indexed: 11/20/2022] Open
Abstract
Understanding the antibody response to HIV-1 in humans that show broad neutralizing serologic activity is a crucial step in trying to reproduce such responses by vaccination. Investigating antibodies with cross clade reactivity is particularly important as these antibodies may target conserved epitopes on the HIV envelope gp160 protein. To this end we have used a clade B YU-2 gp140 trimeric antigen and single-cell antibody cloning methods to obtain 189 new anti-gp140 antibodies representing 51 independent B cell clones from the IgG memory B cells of 3 patients infected with HIV-1 clade A or B viruses and exhibiting broad neutralizing serologic activity. Our results support previous findings showing a diverse antibody response to HIV gp140 envelope protein, characterized by differentially expanded B-cell clones producing highly hypermutated antibodies with heterogenous gp140-specificity and neutralizing activity. In addition to their high-affinity binding to the HIV spike, the vast majority of the new anti-gp140 antibodies are also polyreactive. Although none of the new antibodies are as broad or potent as VRC01 or PG9, two clonally-related antibodies isolated from a clade A HIV-1 infected donor, directed against the gp120 variable loop 3, rank in the top 5% of the neutralizers identified in our large collection of 185 unique gp140-specific antibodies in terms of breadth and potency.
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Affiliation(s)
- Hugo Mouquet
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
| | - Florian Klein
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
| | - Johannes F. Scheid
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
- Charite Universitaetsmedizin, Berlin, Germany
| | - Malte Warncke
- Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - John Pietzsch
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Thiago Y. K. Oliveira
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
- Medical School of Ribeirao Preto/USP, Department of Genetics, National Institute of Science and Technology for Stem Cells and Cell Therapy and Center for Cell-Based Therapy, Ribeirao Preto, Brazil
| | - Klara Velinzon
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
| | - Michael S. Seaman
- Beth Israel Deaconess Medical Center, Boston, Maryland, United States of America
| | - Michel C. Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, United States of America
- Howard Hughes Medical Institute, The Rockefeller University, New York City, New York, United States of America
- * E-mail:
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The gp41 epitope, QARVLAVERY, is highly conserved and a potent inducer of IgA that neutralizes HIV-1 and inhibits viral transcytosis. Mucosal Immunol 2011; 4:539-53. [PMID: 21525865 DOI: 10.1038/mi.2011.21] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mucosal surfaces are the predominant site of human immunodeficiency virus (HIV)-1 transmission. For prophylactic approaches to effectively prevent HIV infection and subsequent dissemination, the induction of mucosally relevant protective immunity will be critical. Here, we have characterized the antibody (Ab) response generated by a highly conserved gp41epitope, QARVLAVERY, in an optimized immunization model that elicits potent epitope-specific Abs in the serum, vaginal washes, and fecal secretions of immunized mice. Our results show that QARVLAVERY is indeed a potent inducer of IgA and importantly, QARVLAVERY-specific IgA was effective in neutralizing HIV and inhibiting viral transcytosis. Intriguingly, QARVLAVERY also generated an approximate 1:1 ratio of IgG:IgA in the serum of immunized mice, independent of the delivery regimen and produced early systemic IgA, even before IgG. In light of the significantly high IgA induction by QARVLAVERY and the functionality of epitope-specific Abs in the inhibition of HIV infection and transcytosis, QARVLAVERY is an attractive epitope to be considered in mucosal vaccination strategies against HIV.
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Maeso R, Huarte N, Julien JP, Kunert R, Pai EF, Nieva JL. Interaction of anti-HIV type 1 antibody 2F5 with phospholipid bilayers and its relevance for the mechanism of virus neutralization. AIDS Res Hum Retroviruses 2011; 27:863-76. [PMID: 21142698 DOI: 10.1089/aid.2010.0265] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Broadly neutralizing monoclonal antibody (MAb) 2F5 targets a linear epitope within the highly conserved membrane proximal external region (MPER) of the HIV-1 envelope protein gp41 integral subunit. Prospective vaccine developments warrant efforts currently underway to unveil the mechanistic and structural basis of its mode of action. One open question relates to the putative role that membrane phospholipids might play in the neutralization process. In this work, we establish experimental conditions that allow monitoring 2F5 insertion into lipid bilayers. Then, we compare the abilities of 2F5-based MAb, Fabs, and 2F5-specific antibodies recovered from immunized rabbits to directly penetrate into lipid bilayers and block the lytic activity of MPER-derived peptides. Antibody insertion induced membrane perturbation, which was blocked on interacting with the peptide epitope, thereby suggesting that such phenomenon was primarily mediated by the epitope-binding site. The long, hydrophobic complementarity-determining region (CDR)-H3 loop contributed little to this effect. In contrast, the CDR-H3 loop was required for blocking the lytic activity of MPER-based peptides and viral neutralization. Thus, our results suggest that core epitope binding plus association with lipid bilayers are not in conjunction sufficient to support viral neutralization by 2F5. Moreover, they support a role for the CDR-H3 loop in establishing secondary interactions with lipids and/or gp41 that would block the membrane-perturbing activity of MPER during fusion.
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Affiliation(s)
- Rubén Maeso
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country, Bilbao, Spain
| | - Nerea Huarte
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country, Bilbao, Spain
| | | | - Renate Kunert
- Institute of Applied Microbiology, University of Agriculture, Vienna, Austria
| | - Emil F. Pai
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- Department of Medical Biophysics and Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Campbell Family Cancer Research Institute, Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Ontario, Canada
| | - José L. Nieva
- Biophysics Unit (CSIC-UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country, Bilbao, Spain
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Reactivity profiles of broadly neutralizing anti-HIV-1 antibodies are distinct from those of pathogenic autoantibodies. AIDS 2011; 25:1247-57. [PMID: 21508803 DOI: 10.1097/qad.0b013e32834785cf] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Broadly neutralizing antibodies (bNt Abs) against HIV-1 are rarely produced during natural infection, and efforts to induce such Abs by vaccination have been unsuccessful. Thus, elucidating the nature and cellular origins of bNt Abs is a high priority for vaccine research. As the bNt monoclonal Abs (MAbs) 2F5, 4E10 and 2G12 have been reported to bind select autoantigens, we investigated whether these MAbs display a broader range of autoreactivity and how their autoreactivity compares with that of pathogenic autoAbs. METHODS An autoantigen microarray comprising 106 connective tissue disease-related autoantigens and control antigens was developed and used, in combination with ELISAs, to compare the reactivity profiles of MAbs 4E10, 2F5 and 2G12 to those of four pathogenic autoAbs derived from patients with antiphospholipid-syndrome (APS), and to serum from a patient with systemic lupus erythematosus (SLE). RESULTS The APS MAbs and SLE serum reacted strongly with multiple autoantigens on the microarray, whereas anti-HIV-1 MAb reactivity was limited mainly to HIV-1-related antigens. The APS autoAbs reacted strongly with CL, yet only 4E10 bound CL at high concentrations; both 2F5 and 4E10 bound their HIV-1 epitopes with a 2-3-log higher apparent affinity than CL. Moreover, the polyreactivity of 4E10, but not CL15, could be blocked with dried milk. CONCLUSION The reactivity profiles of bNt anti-HIV-1 MAbs are fundamentally distinct from those of pathogenic autoAbs that arise from dysregulated tolerance mechanisms. This suggests that the limited polyreactivity observed for the bNt MAbs, and for HIV-1-Nt Abs in general, may arise through alternative mechanisms, such as extensive somatic mutation due to persistent antigen selection during chronic infection.
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Antigen-specific enhancement of natural human IgG antibodies to phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol-4-phosphate, cholesterol, and lipid A by a liposomal vaccine containing lipid A. Vaccine 2011; 29:5137-44. [PMID: 21624414 DOI: 10.1016/j.vaccine.2011.05.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 05/06/2011] [Accepted: 05/13/2011] [Indexed: 01/23/2023]
Abstract
Natural IgG antibodies (NA) to lipids are ubiquitously distributed in sera of healthy humans and are believed to serve beneficial functions. Although NA to lipids generally exhibit germ line or near germ line binding specificities, the antibodies commonly increase transiently in the acute phases of most, if not all, infectious diseases and may serve as a first line of defense. In order to determine whether similar anti-lipid antibodies can be induced by a vaccine in humans, we examined stored sera obtained from volunteers who had previously received a candidate vaccine to Plasmodium falciparum. The vaccine had consisted of liposomes that contained both the recombinant protein antigen and also contained monophosphoryl lipid A (MPLA) as an adjuvant. All of the pre-immune sera contained NA to one or more of the liposomal lipids in the vaccine: dimyristol phosphatidylcholine (DMPC), dimyristoyl phosphatidylglycerol (DMPG), cholesterol, and MPLA. After initial immunization, followed by a boost, increased levels of IgG antibodies to all of the liposomal lipids, especially DMPG and MPLA, were observed by ELISA. Antibodies to phosphatidylinositol-4-phosphate (PIP) above the normal pre-immune NA to PIP were also observed. Although PIP was not present in the immunizing liposomes, based on the adsorption of anti-PIP antibodies by DMPG the anti-PIP antibodies were thought to represent cross-reacting anti-DMPG antibodies. The immune response was apparently antigen-specific in that NA to unrelated lipids, other than PIP, that were not present in the liposomes, galactosyl ceramide and ganglioside GM1, were not increased by the immunization. We conclude that antibodies to DMPC, DMPG, PIP, cholesterol, and MPLA can be induced in humans by immunization with liposomes containing MPLA.
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Peachman KK, Wieczorek L, Matyas GR, Polonis VR, Alving CR, Rao M. The importance of antibody isotype in HIV-1 virus capture assay and in TZM-bl neutralization. Viral Immunol 2011; 23:627-32. [PMID: 21142448 DOI: 10.1089/vim.2010.0061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The binding of murine IgM mAbs to five different clades of HIV-1 was examined using a modified ELISA-based virus capture assay. Two murine multispecific IgM mAbs that exhibit both lipid and gp41 epitope specificities, and one murine IgM mAb that exhibits lipid-binding specificity, were utilized. The binding of the IgG and the IgM isotypes of human mAb 2F5 to clades A through AE were also evaluated. The binding of 2F5 to HIV-1 was dependent upon the antibody isotype. Monoclonal IgM antibodies bound significantly lower amounts of HIV-1 than the corresponding IgG isotype. Although murine IgM mAbs bound HIV-1 to varying degrees in the virus capture assay, they failed to neutralize HIV-1 in a TZM-bl pseudovirus assay. In contrast, 2F5-IgM mAb bound certain HIV-1 isolates, and also neutralized them, although not as efficiently as the 2F5-IgG isotype. Studies on the relationship between virus binding and neutralization in a TZM-bl pseudovirus assay indicated that in most cases, mAbs that exhibited neutralization also bound the virus.
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Affiliation(s)
- Kristina K Peachman
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, Maryland, USA
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Abstract
OBJECTIVES 2F5 and 4E10 are two broadly neutralizing monoclonal antibodies (mAbs) targeting the membrane proximal external region (MPER) of HIV-1 gp41 envelope protein. This region, which contacts the viral membrane, is highly conserved and has been regarded as a promising target for vaccine development. We aimed to clarify the basis of 2F5 and 4E10 molecular interactions with epitope cores in MPER and lipid bilayers. DESIGN Microscopy-based approaches were used to infer and quantify the effects of both mAbs on membranes, in the presence and absence of the epitope cores. Supported lipid bilayers (SLBs), with and without phase separation, were used as membrane models. Fluorescent-labeled and nonlabeled MPER-derived peptides containing both 2F5 and 4E10 epitopes were used. METHODS mAbs 2F5 and 4E10 membrane interactions, in the presence or absence of MPER-derived peptides, were evaluated by combined atomic force and confocal microscopies. RESULTS Both mAbs form lipid-segregated aggregates on SLBs and do not induce other significant membrane perturbations. Furthermore, the affinity of MPER toward membranes is differently affected by both mAbs and correlates with the mAbs-epitope core lipid interactions. 2F5 is able to dock the MPER peptide on the membrane, whereas 4E10 extracts the MPER from the lipid bilayer. CONCLUSION The results reveal the molecular details underneath 2F5/4E10 membrane-epitope binding and a model is proposed to explain the differential mAbs neutralization efficacies, which relates to the exposure of the epitopes in the lipid bilayers and the role of the lipids in mAb-epitope binding.
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Matyas GR, Wieczorek L, Bansal D, Chenine AL, Sanders-Buell E, Tovanabutra S, Kim JH, Polonis V, Alving CR. Inhibition of HIV-1 infection of peripheral blood mononuclear cells by a monoclonal antibody that binds to phosphoinositides and induces secretion of β-chemokines. Biochem Biophys Res Commun 2010; 402:808-12. [PMID: 21040700 PMCID: PMC7173129 DOI: 10.1016/j.bbrc.2010.10.124] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 10/26/2010] [Indexed: 12/05/2022]
Abstract
A murine IgG mAb, WR321, selected for the ability to bind to phosphatidylinositol-4-phosphate and phosphatidylinositol-4,5-bisphosphate, but an inability to bind to any of 17 other lipids, including phosphatidylinositol, was examined as a probe for studying interactions of HIV-1 with primary human peripheral blood mononuclear cells. The WR321 mAb broadly neutralized CCR5-tropic strains of HIV-1 to prevent infection of the cells. The mAb also exhibited direct interaction with cells in the culture, resulting in secretion of chemokines that interfered with the interaction of HIV-1 virions with CCR5, the coreceptor for HIV-1 on the susceptible cells, leading to inhibition of infection by HIV-1. Phosphoinositides that are recognized by WR321 do not exist on the external surface of cells, but are concentrated on the inner surface (cytoplasmic leaflet) of the plasma membrane. Murine anti-phosphoinositide mAbs similar to WR321 have previously been directly microinjected into a variety of cultured cells, resulting in important changes in the functions of the cells. The present results suggest that binding of a mAb to phosphoinositides, resulting in secretion of β-chemokines into the culture medium and neutralization of infection by CCR5-tropic HIV-1 of nearby susceptible cells, occurred by uptake and binding of the mAb at an intracellular location in the cultured cells that then led to secretion of HIV-1-inhibitory β-chemokines.
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Affiliation(s)
- Gary R Matyas
- Division of Retrovirology, Walter Reed Army Institute of Research, Rockville, MD 20850, USA
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The effect of sCD4 on the binding and accessibility of HIV-1 gp41 MPER epitopes to human monoclonal antibodies. Virology 2010; 408:213-23. [PMID: 20961591 DOI: 10.1016/j.virol.2010.09.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 07/13/2010] [Accepted: 09/23/2010] [Indexed: 11/23/2022]
Abstract
Two human monoclonal anti-HIV-1 antibodies, 2F5 and 4E10, were utilized to investigate the accessibility and conservation of gp41 MPER epitopes on five different clades of HIV-1 in the absence and presence of sCD4. The binding of human monoclonal antibodies (mAbs) to HIV-1 was dependent upon the virus clade. Soluble CD4 significantly increased the accessibility of gp41 MPER-binding epitopes on several isolates that previously showed little or no binding with 2F5 and 4E10 mAbs as determined by a modified ELISA-based virus capture assay and surface plasmon resonance. Studies on the relationship between virus binding and neutralization in a TZM-bl pseudovirus assay indicated that in most cases, mAbs that exhibited neutralization also bound the virus. However, neither binding per se nor the total envelope content per virion was a predictor of neutralization. The hidden or conformational gp41 MPER epitopes unmasked by sCD4 may provide additional targets for vaccine design.
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Mohr EL, Xiang J, McLinden JH, Kaufman TM, Chang Q, Montefiori DC, Klinzman D, Stapleton JT. GB virus type C envelope protein E2 elicits antibodies that react with a cellular antigen on HIV-1 particles and neutralize diverse HIV-1 isolates. THE JOURNAL OF IMMUNOLOGY 2010; 185:4496-505. [PMID: 20826757 DOI: 10.4049/jimmunol.1001980] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Broadly neutralizing Abs to HIV-1 are well described; however, identification of Ags that elicit these Abs has proven difficult. Persistent infection with GB virus type C (GBV-C) is associated with prolonged survival in HIV-1-infected individuals, and among those without HIV-1 viremia, the presence of Ab to GBV-C glycoprotein E2 is also associated with survival. GBV-C E2 protein inhibits HIV-1 entry, and an antigenic peptide within E2 interferes with gp41-induced membrane perturbations in vitro, suggesting the possibility of structural mimicry between GBV-C E2 protein and HIV-1 particles. Naturally occurring human and experimentally induced GBV-C E2 Abs were examined for their ability to neutralize infectious HIV-1 particles and HIV-1-enveloped pseudovirus particles. All GBV-C E2 Abs neutralized diverse isolates of HIV-1 with the exception of rabbit anti-peptide Abs raised against a synthetic GBV-C E2 peptide. Rabbit anti-GBV-C E2 Abs neutralized HIV-1-pseudotyped retrovirus particles but not HIV-1-pseudotyped vesicular stomatitis virus particles, and E2 Abs immune-precipitated HIV-1 gag particles containing the vesicular stomatitis virus type G envelope, HIV-1 envelope, GBV-C envelope, or no viral envelope. The Abs did not neutralize or immune-precipitate mumps or yellow fever viruses. Rabbit GBV-C E2 Abs inhibited HIV attachment to cells but did not inhibit entry following attachment. Taken together, these data indicate that the GBV-C E2 protein has a structural motif that elicits Abs that cross-react with a cellular Ag present on retrovirus particles, independent of HIV-1 envelope glycoproteins. The data provide evidence that a heterologous viral protein can induce HIV-1-neutralizing Abs.
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Affiliation(s)
- Emma L Mohr
- Division of Infectious Diseases, Department of Internal Medicine, Iowa City Veterans Affairs Medical Center, Iowa City, IA 52242, USA
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Apellaniz B, García-Sáez AJ, Huarte N, Kunert R, Vorauer-Uhl K, Katinger H, Schwille P, Nieva JL. Confocal microscopy of giant vesicles supports the absence of HIV-1 neutralizing 2F5 antibody reactivity to plasma membrane phospholipids. FEBS Lett 2010; 584:1591-6. [DOI: 10.1016/j.febslet.2010.03.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 03/12/2010] [Accepted: 03/12/2010] [Indexed: 11/26/2022]
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Ablation of the complementarity-determining region H3 apex of the anti-HIV-1 broadly neutralizing antibody 2F5 abrogates neutralizing capacity without affecting core epitope binding. J Virol 2010; 84:4136-47. [PMID: 20147404 DOI: 10.1128/jvi.02357-09] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The identification and characterization of broadly neutralizing antibodies (bnAbs) against HIV-1 has formed a major research focus, with the ultimate goal to help in the design of an effective AIDS vaccine. One of these bnAbs, 2F5, has been extensively characterized, and residues at the apex of its unusually long complementarity-determining region (CDR) H3 loop have been shown to be crucial for neutralization. Structural studies, however, have revealed that the (100)TLFGVPI(100F) apex residues of the CDR H3 loop do not interact directly with residues of its core gp41 epitope. In an attempt to gain better insight into the functional role of this element, we have recombinantly expressed native 2F5 Fab and two mutants in which either the apical Phe100B(H) residue was changed to an alanine or the CDR H3 residues (100)TLFGVPI(100F) were replaced by a Ser-Gly dipeptide linker. Isothermal titration calorimetry (ITC) and competitive-binding enzyme-linked immunosorbent assays (ELISAs) rendered strikingly similar affinity constants (K(d) [dissociation constant] of approximately 20 nM) for linear peptide epitope binding by 2F5 Fabs, independent of the presence or absence of the apex residues. Ablation of the CDR H3 apex residues, however, abolished the cell-cell fusion inhibition and pseudovirus neutralization capacities of 2F5 Fab. We report competitive ELISA data that suggest a role of 2F5 CDR H3 apex residues in mediating weak hydrophobic interactions with residues located at the C terminus of the gp41 membrane proximal external region and/or membrane components in the context of core epitope binding. The present data therefore imply an extended 2F5 paratope that includes weak secondary interactions that are crucial for neutralization of Env-mediated fusion.
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