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Caputo V, Negri I, Moudoud L, Libera M, Bonizzi L, Clementi M, Diotti RA. Anti-HIV Humoral Response Induced by Different Anti-Idiotype Antibody Formats: An In Silico and In Vivo Approach. Int J Mol Sci 2024; 25:5737. [PMID: 38891926 PMCID: PMC11171986 DOI: 10.3390/ijms25115737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024] Open
Abstract
Despite advancements in vaccinology, there is currently no effective anti-HIV vaccine. One strategy under investigation is based on the identification of epitopes recognized by broadly neutralizing antibodies to include in vaccine preparation. Taking into account the benefits of anti-idiotype molecules and the diverse biological attributes of different antibody formats, our aim was to identify the most immunogenic antibody format. This format could serve as a foundational element for the development of an oligo-polyclonal anti-idiotype vaccine against HIV-1. For our investigation, we anchored our study on an established b12 anti-idiotype, referred to as P1, and proposed four distinct formats: two single chains and two minibodies, both in two different orientations. For a deeper characterization of these molecules, we used immunoinformatic tools and tested them on rabbits. Our studies have revealed that a particular minibody conformation, MbVHVL, emerges as the most promising candidate. It demonstrates a significant binding affinity with b12 and elicits a humoral anti-HIV-1 response in rabbits similar to the Fab format. This study marks the first instance where the minibody format has been shown to provoke a humoral response against a pathogen. Furthermore, this format presents biological advantages over the Fab format, including bivalency and being encoded by a monocistronic gene, making it better suited for the development of RNA-based vaccines.
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Affiliation(s)
- Valeria Caputo
- Pomona Ricerca S.r.l, Via Assarotti 7, 10122 Turin, Italy
- One Health Unit, Department of Biomedical, Surgical and Dental Sciences, School of Medicine, University of Milan, Via Pascal 36, 20133 Milan, Italy
| | - Ilaria Negri
- Pomona Ricerca S.r.l, Via Assarotti 7, 10122 Turin, Italy
| | - Louiza Moudoud
- Pomona Ricerca S.r.l, Via Assarotti 7, 10122 Turin, Italy
- One Health Unit, Department of Biomedical, Surgical and Dental Sciences, School of Medicine, University of Milan, Via Pascal 36, 20133 Milan, Italy
| | - Martina Libera
- Pomona Ricerca S.r.l, Via Assarotti 7, 10122 Turin, Italy
- One Health Unit, Department of Biomedical, Surgical and Dental Sciences, School of Medicine, University of Milan, Via Pascal 36, 20133 Milan, Italy
| | - Luigi Bonizzi
- One Health Unit, Department of Biomedical, Surgical and Dental Sciences, School of Medicine, University of Milan, Via Pascal 36, 20133 Milan, Italy
| | - Massimo Clementi
- Pomona Ricerca S.r.l, Via Assarotti 7, 10122 Turin, Italy
- Laboratory of Microbiology and Virology, ‘Vita-Salute’ San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Roberta Antonia Diotti
- Pomona Ricerca S.r.l, Via Assarotti 7, 10122 Turin, Italy
- One Health Unit, Department of Biomedical, Surgical and Dental Sciences, School of Medicine, University of Milan, Via Pascal 36, 20133 Milan, Italy
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Wang W, Truong K, Ye C, Sharma S, He H, Liu L, Wen M, Misra A, Zhou P, Kimata JT. Engineered CD4 T cells expressing a membrane anchored viral inhibitor restrict HIV-1 through cis and trans mechanisms. Front Immunol 2023; 14:1167965. [PMID: 37781368 PMCID: PMC10538569 DOI: 10.3389/fimmu.2023.1167965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 08/31/2023] [Indexed: 10/03/2023] Open
Abstract
HIV-1 infection of target cells can occur through either cell-free virions or cell-cell transmission in a virological synapse, with the latter mechanism of infection reported to be 100- to 1,000-fold more efficient. Neutralizing antibodies and entry inhibitors effectively block cell-free HIV-1, but with few exceptions, they display much less inhibitory activity against cell-mediated HIV-1 transmission. Previously, we showed that engineering HIV-1 target cells by genetically linking single-chain variable fragments (scFvs) of antibodies to glycosyl phosphatidylinositol (GPI) potently blocks infection by cell-free virions and cell-mediated infection by immature dendritic cell (iDC)-captured HIV-1. Expression of scFvs on CD4+ cell lines by transduction with X5 derived anti-HIV-1 Env antibody linked to a GPI attachment signal directs GPI-anchored scFvs into lipid rafts of the plasma membrane. In this study, we further characterize the effect of GPI-scFv X5 on cell-cell HIV-1 transmission from DCs to target cells. We report that expression of GPI-scFv X5 in transduced CD4+ cell lines and human primary CD4+ T cells potently restricts viral replication in iDC- or mDC-captured HIV-1 in trans. Using live-cell imaging, we observed that when GPI-GFP or GPI-scFv X5 transduced T cells are co-cultured with iDCs, GPI-anchored proteins enrich in contact zones and subsequently migrate from T cells into DCs, suggesting that transferred GPI-scFv X5 interferes with HIV-1 infection of iDCs. We conclude that GPI-scFv X5 on the surface of transduced CD4+ T cells not only potently blocks cell-mediated infection by DCs, but it transfers from transduced cells to the surface of iDCs and neutralizes HIV-1 replication in iDCs. Our findings have important implications for HIV-1 antibody-based immunotherapies as they demonstrate a viral inhibitory effect that extends beyond the transduced CD4+ T cells to iDCs which can enhance HIV-1 replication.
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Affiliation(s)
- Weiming Wang
- Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Khanghy Truong
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States
| | - Chaobaihui Ye
- Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Suman Sharma
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States
| | - Huan He
- Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Lihong Liu
- Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Michael Wen
- Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Anisha Misra
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States
| | - Paul Zhou
- Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Jason T. Kimata
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, United States
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Struble EB, Rawson JMO, Stantchev T, Scott D, Shapiro MA. Uses and Challenges of Antiviral Polyclonal and Monoclonal Antibody Therapies. Pharmaceutics 2023; 15:pharmaceutics15051538. [PMID: 37242780 DOI: 10.3390/pharmaceutics15051538] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/04/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Viral diseases represent a major public health concerns and ever-present risks for developing into future pandemics. Antiviral antibody therapeutics, either alone or in combination with other therapies, emerged as valuable preventative and treatment options, including during global emergencies. Here we will discuss polyclonal and monoclonal antiviral antibody therapies, focusing on the unique biochemical and physiological properties that make them well-suited as therapeutic agents. We will describe the methods of antibody characterization and potency assessment throughout development, highlighting similarities and differences between polyclonal and monoclonal products as appropriate. In addition, we will consider the benefits and challenges of antiviral antibodies when used in combination with other antibodies or other types of antiviral therapeutics. Lastly, we will discuss novel approaches to the characterization and development of antiviral antibodies and identify areas that would benefit from additional research.
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Affiliation(s)
- Evi B Struble
- Division of Plasma Derivatives, Office of Plasma Protein Therapeutics CMC, Office of Therapeutic Products, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Jonathan M O Rawson
- Division of Antivirals, Office of Infectious Diseases, Office of New Drugs, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Tzanko Stantchev
- Division of Biotechnology Review and Research 1, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Dorothy Scott
- Division of Plasma Derivatives, Office of Plasma Protein Therapeutics CMC, Office of Therapeutic Products, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Marjorie A Shapiro
- Division of Biotechnology Review and Research 1, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
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4
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Across Functional Boundaries: Making Nonneutralizing Antibodies To Neutralize HIV-1 and Mediate Fc-Mediated Effector Killing of Infected Cells. mBio 2021; 12:e0140521. [PMID: 34579568 PMCID: PMC8546553 DOI: 10.1128/mbio.01405-21] [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] [Indexed: 12/30/2022] Open
Abstract
In HIV-1 infection, many antibodies (Abs) are elicited to Envelope (Env) epitopes that are conformationally masked in the native trimer and are only available for antibody recognition after the trimer binds host cell CD4. Among these are epitopes within the Co-Receptor Binding Site (CoRBS) and the constant region 1 and 2 (C1-C2 or cluster A region). In particular, C1-C2 epitopes map to the gp120 face interacting with gp41 in the native, "closed" Env trimer present on HIV-1 virions or expressed on HIV-1-infected cells. Antibodies targeting this region are therefore nonneutralizing and their potential as mediators of antibody-dependent cellular cytotoxicity (ADCC) of HIV-1-infected cells diminished by a lack of available binding targets. Here, we present the design of Ab-CD4 chimeric proteins that consist of the Ab-IgG1 of a CoRBS or cluster A specificity to the extracellular domains 1 and 2 of human CD4. Our Ab-CD4 hybrids induce potent ADCC against infected primary CD4+ T cells and neutralize tier 1 and 2 HIV-1 viruses. Furthermore, competition binding experiments reveal that the observed biological activities rely on both the antibody and CD4 moieties, confirming their cooperativity in triggering conformational rearrangements of Env. Our data indicate the utility of these Ab-CD4 hybrids as antibody therapeutics that are effective in eliminating HIV-1 through the combined mechanisms of neutralization and ADCC. This is also the first report of single-chain-Ab-based molecules capable of opening "closed" Env trimers on HIV-1 particles/infected cells to expose the cluster A region and activate ADCC and neutralization against these nonneutralizing targets. IMPORTANCE Highly conserved epitopes within the coreceptor binding site (CoRBS) and constant region 1 and 2 (C1-C2 or cluster A) are only available for antibody recognition after the HIV-1 Env trimer binds host cell CD4; therefore, they are not accessible on virions and infected cells, where the expression of CD4 is downregulated. Here, we have developed new antibody fusion molecules in which domains 1 and 2 of soluble human CD4 are linked with monoclonal antibodies of either the CoRBS or cluster A specificity. We optimized the conjugation sites and linker lengths to allow each of these novel bispecific fusion molecules to recognize native "closed" Env trimers and induce the structural rearrangements required for exposure of the epitopes for antibody binding. Our in vitro functional testing shows that our Ab-CD4 molecules can efficiently target and eliminate HIV-1-infected cells through antibody-dependent cellular cytotoxicity and inactivate HIV-1 virus through neutralization.
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5
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Chikaev AN, Chikaev AN, Rudometov AP, Merkulyeva YA, Karpenko LI. Phage display as a tool for identifying HIV-1 broadly neutralizing antibodies. Vavilovskii Zhurnal Genet Selektsii 2021; 25:562-572. [PMID: 34595378 PMCID: PMC8453360 DOI: 10.18699/vj21.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/14/2021] [Accepted: 03/22/2021] [Indexed: 11/19/2022] Open
Abstract
Combinatorial biology methods offer a good solution for targeting interactions of specif ic molecules
by a high-throughput screening and are widely used for drug development, diagnostics, identif ication of novel
monoclonal antibodies, search for linear peptide mimetics of discontinuous epitopes for the development of
immunogens or vaccine components. Among all currently available techniques, phage display remains one of
the most popular approaches. Despite being a fairly old method, phage display is still widely used for studying
protein-protein, peptide-protein and DNA-protein interactions due to its relative simplicity and versatility. Phage
display allows highly representative libraries of peptides, proteins or their fragments to be created. Each phage
particle in a library displays peptides or proteins fused to its coat protein and simultaneously carries the DNA
sequence encoding the displayed peptide/protein in its genome. The biopanning procedure allows isolation of
specif ic clones for almost any target, and due to the physical link between the genotype and the phenotype of
recombinant phage particles it is possible to determine the structure of selected molecules. Phage display technology
continues to play an important role in HIV research. A major obstacle to the development of an effective
HIV vaccine is an extensive genetic and antigenic variability of the virus. According to recent data, in order to provide
protection against HIV infection, the so-called broadly neutralizing antibodies that are cross-reactive against
multiple viral strains of HIV must be induced, which makes the identif ication of such antibodies a key area of HIV
vaccinology. In this review, we discuss the use of phage display as a tool for identif ication of HIV-specif ic antibodies
with broad neutralizing activity. We provide an outline of phage display technology, brief ly describe the
design of antibody phage libraries and the affinity selection procedure, and discuss the biology of HIV-1-specif ic
broadly neutralizing antibodies. Finally, we summarize the studies aimed at identif ication of broadly neutralizing
antibodies using various types of phage libraries.
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Affiliation(s)
| | - A N Chikaev
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A P Rudometov
- State Research Center of Virology and Biotechnology "Vector", Rospotrebnadzor, Koltsovo, Novosibirsk region, Russia
| | - Yu A Merkulyeva
- State Research Center of Virology and Biotechnology "Vector", Rospotrebnadzor, Koltsovo, Novosibirsk region, Russia
| | - L I Karpenko
- State Research Center of Virology and Biotechnology "Vector", Rospotrebnadzor, Koltsovo, Novosibirsk region, Russia
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Shalash AO, Hussein WM, Skwarczynski M, Toth I. Key Considerations for the Development of Safe and Effective SARS-CoV-2 Subunit Vaccine: A Peptide-Based Vaccine Alternative. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100985. [PMID: 34176237 PMCID: PMC8373118 DOI: 10.1002/advs.202100985] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/18/2021] [Indexed: 05/14/2023]
Abstract
COVID-19 is disastrous to global health and the economy. SARS-CoV-2 infection exhibits similar clinical symptoms and immunopathological sequelae to SARS-CoV infection. Therefore, much of the developmental progress on SARS-CoV vaccines can be utilized for the development of SARS-CoV-2 vaccines. Careful antigen selection during development is always of utmost importance for the production of effective vaccines that do not compromise recipient safety. This holds especially true for SARS-CoV vaccines, as several immunopathological disorders are associated with the activity of structural and nonstructural proteins encoded in the virus's genetic material. Whole viral protein and RNA-encoding full-length proteins contain both protective and "dangerous" sequences, unless pathological fragments are deleted. In light of recent advances, peptide vaccines may present a very safe and effective alternative. Peptide vaccines can avoid immunopathological pro-inflammatory sequences, focus immune responses on neutralizing immunogenic epitopes, avoid off-target antigen loss, combine antigens with different protective roles or mechanisms, even from different viral proteins, and avoid mutant escape by employing highly conserved cryptic epitopes. In this review, an attempt is made to exploit the similarities between SARS-CoV and SARS-CoV-2 in vaccine antigen screening, with particular attention to the pathological and immunogenic properties of SARS proteins.
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Affiliation(s)
- Ahmed O. Shalash
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt. LuciaQLD4072Australia
| | - Waleed M. Hussein
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt. LuciaQLD4072Australia
| | - Mariusz Skwarczynski
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt. LuciaQLD4072Australia
| | - Istvan Toth
- School of Chemistry and Molecular BiosciencesThe University of QueenslandSt. LuciaQLD4072Australia
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaQLD4072Australia
- School of PharmacyThe University of QueenslandWoolloongabbaQLD4102Australia
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7
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Tolbert WD, Sherburn R, Gohain N, Ding S, Flinko R, Orlandi C, Ray K, Finzi A, Lewis GK, Pazgier M. Defining rules governing recognition and Fc-mediated effector functions to the HIV-1 co-receptor binding site. BMC Biol 2020; 18:91. [PMID: 32693837 PMCID: PMC7374964 DOI: 10.1186/s12915-020-00819-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 06/22/2020] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The binding of HIV-1 Envelope glycoproteins (Env) to host receptor CD4 exposes vulnerable conserved epitopes within the co-receptor binding site (CoRBS) which are required for the engagement of either CCR5 or CXCR4 co-receptor to allow HIV-1 entry. Antibodies against this region have been implicated in the protection against HIV acquisition in non-human primate (NHP) challenge studies and found to act synergistically with antibodies of other specificities to deliver effective Fc-mediated effector function against HIV-1-infected cells. Here, we describe the structure and function of N12-i2, an antibody isolated from an HIV-1-infected individual, and show how the unique structural features of this antibody allow for its effective Env recognition and Fc-mediated effector function. RESULTS N12-i2 binds within the CoRBS utilizing two adjacent sulfo-tyrosines (TYS) for binding, one of which binds to a previously unknown TYS binding pocket formed by gp120 residues of high sequence conservation among HIV-1 strains. Structural alignment with gp120 in complex with the co-receptor CCR5 indicates that the new pocket corresponds to TYS at position 15 of CCR5. In addition, structure-function analysis of N12-i2 and other CoRBS-specific antibodies indicates a link between modes of antibody binding within the CoRBS and Fc-mediated effector activities. The efficiency of antibody-dependent cellular cytotoxicity (ADCC) correlated with both the level of antibody binding and the mode of antibody attachment to the epitope region, specifically with the way the Fc region was oriented relative to the target cell surface. Antibodies with poor Fc access mediated the poorest ADCC whereas those with their Fc region readily accessible for interaction with effector cells mediated the most potent ADCC. CONCLUSION Our data identify a previously unknown binding site for TYS within the assembled CoRBS of the HIV-1 virus. In addition, our combined structural-modeling-functional analyses provide new insights into mechanisms of Fc-effector function of antibodies against HIV-1, in particular, how antibody binding to Env antigen affects the efficiency of ADCC response.
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Affiliation(s)
- William D Tolbert
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Rebekah Sherburn
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Neelakshi Gohain
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Shilei Ding
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Robin Flinko
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Chiara Orlandi
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Krishanu Ray
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - George K Lewis
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA
| | - Marzena Pazgier
- Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814-4712, USA.
- Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA.
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FIV vaccine with receptor epitopes results in neutralizing antibodies but does not confer resistance to challenge. NPJ Vaccines 2018; 3:16. [PMID: 29736270 PMCID: PMC5928050 DOI: 10.1038/s41541-018-0051-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/16/2018] [Accepted: 03/21/2018] [Indexed: 11/09/2022] Open
Abstract
Feline immunodeficiency virus (FIV) is the feline analogue to human immunodeficiency virus (HIV) and utilizes parallel modes of receptor-mediated entry. The FIV surface glycoprotein (SU) is an important target for induction of neutralizing antibodies, and autoantibodies to the FIV binding receptor (CD134) block infection ex vivo; thus highlighting the potential for immunotherapies which utilize anti-receptor antibodies to block viral infection. To determine whether vaccination with CD134-SU complexes could induce protection against FIV infection, cats (n = 5 per group) were immunized with soluble CD134, recombinant FIV-SU protein, and/or CD134+SU complexes. Two trials were performed with different antigen combinations and vaccination schedules. In vivo generation of anti-CD134 and anti-SU IgG antibodies was measured, and in vitro neutralization assays were conducted. Immunization induced production of anti-CD134 and anti-SU antibodies that significantly inhibited FIV infection in vitro. However, no vaccine combination protected cats from FIV infection, and neat serum from vaccinated cats enhanced FIV growth in vitro. CD134+SU vaccinated cats exhibited increased CD4:CD8 ratio immediately prior to challenge, and antibodies were much more efficiently generated against vaccine by-products versus target antigens. Results suggest vaccination against viral and cryptic receptor epitopes yields neutralizing antibodies that synergistically inhibit FIV infection in vitro. Factors contributing to vaccine failure may include: (1) Heat-labile serum factors that enhance viral replication, (2) changes in circulating target cell populations induced by vaccination, and (3) weak immunogenicity of neutralizing epitopes compared to off-target vaccine components. Results reinforce the need to monitor vaccine preparation components and avoid non-specific immune stimulation during vaccination. A vaccine candidate for feline immunodeficiency virus elicits strong immunological reaction in vitro, but no protection to live cats. The feline analog to human immunodeficiency virus, FIV shares a similar infection paradigm and has only one partially effective vaccine. A US team, led by Colorado State University’s Susan VandeWoude, immunized cats using a complex of an FIV surface protein and a feline cell-surface protein known to facilitate FIV’s entry into immune cells. Tissue culture assays yielded promising results; however, this did not translate to live-animal protection. The researchers highlighted multiple factors that could explain the lack of success, including circulatory pro-infection factors, and immune responses generated against vaccine by-products rather than intended targets. While the vaccine candidate failed, the research provides invaluable guidance for future efforts into FIV vaccination with implications for HIV vaccine trials.
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Glycosyl-Phosphatidylinositol-Anchored Anti-HIV Env Single-Chain Variable Fragments Interfere with HIV-1 Env Processing and Viral Infectivity. J Virol 2018; 92:JVI.02080-17. [PMID: 29321330 DOI: 10.1128/jvi.02080-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/02/2018] [Indexed: 11/20/2022] Open
Abstract
In previous studies, we demonstrated that single-chain variable fragments (scFvs) from anti-human immunodeficiency virus (HIV) Env monoclonal antibodies act as entry inhibitors when tethered to the surface of target cells by a glycosyl-phosphatidylinositol (GPI) anchor. Interestingly, even if a virus escapes inhibition at entry, its replication is ultimately controlled. We hypothesized that in addition to functioning as entry inhibitors, anti-HIV GPI-scFvs may also interact with Env in an infected cell, thereby interfering with the infectivity of newly produced virions. Here, we show that expression of the anti-HIV Env GPI-scFvs in virus-producing cells reduced the release of HIV from cells 5- to 22-fold, and infectivity of the virions that were released was inhibited by 74% to 99%. Additionally, anti-HIV Env GPI-scFv X5 inhibited virion production and infectivity after latency reactivation and blocked transmitter/founder virus production and infectivity in primary CD4+ T cells. In contrast, simian immunodeficiency virus (SIV) production and infectivity were not affected by the anti-HIV Env GPI-scFvs. Loss of infectivity of HIV was associated with a reduction in the amount of virion-associated Env gp120. Interestingly, an analysis of Env expression in cell lysates demonstrated that the anti-Env GPI-scFvs interfered with processing of Env gp160 precursors in cells. These data indicate that GPI-scFvs can inhibit Env processing and function, thereby restricting production and infectivity of newly synthesized HIV. Anti-Env GPI-scFvs therefore appear to be unique anti-HIV molecules as they derive their potent inhibitory activity by interfering with both early (receptor binding/entry) and late (Env processing and incorporation into virions) stages of the HIV life cycle.IMPORTANCE The restoration of immune function and persistence of CD4+ T cells in HIV-1-infected individuals without antiretroviral therapy requires a way to increase resistance of CD4+ T cells to infection by both R5- and X4-tropic HIV-1. Previously, we reported that anchoring anti-HIV-1 single-chain variable fragments (scFvs) via glycosyl-phosphatidylinositol (GPI) to the surface of permissive cells conferred a high level of resistance to HIV-1 variants at the level of entry. Here, we report that anti-HIV GPI-scFvs also derive their potent antiviral activity in part by blocking HIV production and Env processing, which consequently inhibits viral infectivity even in primary infection models. Thus, we conclude that GPI-anchored anti-HIV scFvs derive their potent blocking activity of HIV replication by interfering with successive stages of the viral life cycle. They may be effectively used in genetic intervention of HIV-1 infection.
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Identification of Novel Structural Determinants in MW965 Env That Regulate the Neutralization Phenotype and Conformational Masking Potential of Primary HIV-1 Isolates. J Virol 2018; 92:JVI.01779-17. [PMID: 29237828 DOI: 10.1128/jvi.01779-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/28/2017] [Indexed: 11/20/2022] Open
Abstract
The subtype C HIV-1 isolate MW965.26 is a highly neutralization-sensitive tier 1a primary isolate that is widely used in vaccine studies, but the basis for the sensitive neutralization phenotype of this isolate is not known. Substituting the MW965.26 V1/V2 domain into a neutralization-sensitive SF162 Env clone resulted in high resistance to standard anti-V3 monoclonal antibodies, demonstrating that this region possesses strong masking activity in a standard Env backbone and indicating that determinants elsewhere in MW965.26 Env are responsible for its unusual neutralization sensitivity. Key determinants for this phenotype were mapped by generating chimeric Envs between MW965.26 Env and a typical resistant Env clone, the consensus C (ConC) clone, and localized to two residues, Cys384 in the C3 domain and Asn502 in the C5 domain. Substituting the sensitizing mutations Y384C and K502N at these positions into several resistant primary Envs resulted in conversion to neutralization-sensitive phenotypes, demonstrating the generalizability of this effect. In contrast to the sensitizing effects of these substitutions on normally masked epitopes, these mutations reduced the sensitivity of VRC01-like epitopes overlapping the CD4-binding domain, while they had no effect on several other classes of broadly neutralizing epitopes, including members of several lineages of V2-dependent quaternary epitopes and representatives of N332 glycan-dependent epitopes (PGT121) and quaternary, cleavage-dependent epitopes centered at the gp41-gp120 interface on intact HIV-1 Env trimers (PGT151). These results identify novel substitutions in gp120 that regulate the expression of alternative conformations of Env and differentially affect the exposure of different classes of epitopes, thereby influencing the neutralization phenotype of primary HIV-1 isolates.IMPORTANCE A better understanding of the mechanisms that determine the wide range of neutralization sensitivity of circulating primary HIV-1 isolates would provide important information about the natural structural and conformational diversity of HIV-1 Env and how this affects the neutralization phenotype. A useful way of studying this is to determine the molecular basis for the unusually high neutralization sensitivities of the limited number of available tier 1a viruses. This study localized the neutralization sensitivity of MW965.26, an extremely sensitive subtype C-derived primary isolate, to two rare substitutions in the C3 and C5 domains and demonstrated that the sequences at these positions differentially affect the presentation of epitopes recognized by different classes of standard and conformation-dependent broadly neutralizing antibodies. These results provide novel insight into how these regions regulate the neutralization phenotype and provide tools for controlling the Env conformation that could have applications both for structural studies and in vaccine design.
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Abstract
PURPOSE OF REVIEW Since 2009 many broadly neutralizing antibodies against HIV have been identified, yet there is still no vaccine capable of inducing such antibodies in humans. This review considers the early observations of HIV sera neutralization in light of more recent studies and highlights areas for future research. RECENT FINDINGS Large clinical cohort studies using standardized neutralization assays and pseudoviruses derived from primary isolates have shown that 10-30% of HIV infections result in some level of serum neutralization breadth. However, less than 10% of individuals develop a greater breadth of neutralization and are termed elite neutralizers. SUMMARY During HIV infection, many individuals develop strain-specific neutralization against their viral quasispecies, and similar immunogen-matched activity can now be induced in animal models. However, only in a minority of infections do broadly neutralizing antibodies develop. Therefore, understanding how the viral diversity, host immune environment, and antibody repertoires intersect to support the generation of neutralization breadth in elite neutralizers could provide guidelines as to how to improve immunization responses.
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Tang X, Guo J, Cheng L, Sun C, Liu L, Zuo T, Wang H, Chen L, Zhang L, Chen Z. Single N277A substitution in C2 of simian immunodeficiency virus envelope influences vaccine-elicited CD4i neutralizing and anti-V2 antibody responses. Vaccine 2017; 35:2582-2591. [PMID: 28366604 DOI: 10.1016/j.vaccine.2017.03.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 03/16/2017] [Accepted: 03/17/2017] [Indexed: 10/19/2022]
Abstract
An effective HIV vaccine remains elusive, and immunogens capable of eliciting protective host humoral immunity have not yet been identified. Although HIV/SIV infections result in the abundant production of CD4-induced (CD4i) antibodies (Abs), these Abs are not protective due to steric restrictions following gp120 binding to CD4 on target cells. Here we report that both DNA- and vaccinia-based vaccines encoding SIVmac239 gp160 readily elicited high levels of CD4i Abs in experimental animals. We identified a highly conserved N-linked glycosylation site N277 in the C2 region which strongly affected the immunogenicity of the CD4i Ab domain. Moreover, a single N277A substitution significantly enhanced the immunogenicity of the V2 domain yielding higher titers and frequency of anti-V2 Ab responses as determined by ELISA and yeast antigen display mapping, respectively. Importantly, immune sera elicited by the N277A-mutated gp160 exhibited elevated antibody-dependent cellular cytotoxicity (ADCC) activity. ADCC activity correlated positively with the anti-V2 Ab titer yet, inversely with CD4i Ab titer. Thus, we identified a determinant of the CD4i domain that might affect vaccine-elicited anti-V2 Ab and ADCC responses to SIVmac239. Our findings may have implications for design of immunogens to direct B cell recognition in the development of an Ab-based HIV vaccine.
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Affiliation(s)
- Xian Tang
- HKU-AIDS Institute Shenzhen Research Laboratory, Guangdong Key Lab of Emerging Infectious Diseases and Shenzhen Key Lab of Infection and Immunity, Shenzhen Third People's Hospital, Shenzhen, China; AIDS Institute and Department of Microbiology, State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Jia Guo
- AIDS Institute and Department of Microbiology, State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Lin Cheng
- HKU-AIDS Institute Shenzhen Research Laboratory, Guangdong Key Lab of Emerging Infectious Diseases and Shenzhen Key Lab of Infection and Immunity, Shenzhen Third People's Hospital, Shenzhen, China
| | - Caijun Sun
- State Key Laboratory of Respiratory Diseases, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Li Liu
- AIDS Institute and Department of Microbiology, State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Teng Zuo
- Comprehensive AIDS Research Center and Research Center for Public Health, School of Medicine, Tsinghua University, Beijing, China
| | - Hui Wang
- HKU-AIDS Institute Shenzhen Research Laboratory, Guangdong Key Lab of Emerging Infectious Diseases and Shenzhen Key Lab of Infection and Immunity, Shenzhen Third People's Hospital, Shenzhen, China
| | - Ling Chen
- State Key Laboratory of Respiratory Diseases, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Linqi Zhang
- Comprehensive AIDS Research Center and Research Center for Public Health, School of Medicine, Tsinghua University, Beijing, China
| | - Zhiwei Chen
- HKU-AIDS Institute Shenzhen Research Laboratory, Guangdong Key Lab of Emerging Infectious Diseases and Shenzhen Key Lab of Infection and Immunity, Shenzhen Third People's Hospital, Shenzhen, China; AIDS Institute and Department of Microbiology, State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
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Glycosylphosphatidylinositol-Anchored Anti-HIV scFv Efficiently Protects CD4 T Cells from HIV-1 Infection and Deletion in hu-PBL Mice. J Virol 2017; 91:JVI.01389-16. [PMID: 27881659 DOI: 10.1128/jvi.01389-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/17/2016] [Indexed: 11/20/2022] Open
Abstract
Despite success in viral inhibition and CD4 T cell recovery by highly active antiretroviral treatment (HAART), HIV-1 is still not curable due to the persistence of the HIV-1 reservoir during treatment. One patient with acute myeloid leukemia who received allogeneic hematopoietic stem cell transplantation from a homozygous CCR5 Δ32 donor has had no detectable viremia for 9 years after HAART cessation. This case has inspired a field of HIV-1 cure research focusing on engineering HIV-1 resistance in permissive cells. Here, we employed a glycosylphosphatidylinositol (GPI)-scFv X5 approach to confer resistance of human primary CD4 T cells to HIV-1. We showed that primary CD4 T cells expressing GPI-scFv X5 were resistant to CCR5 (R5)-, CXCR4 (X4)-, and dual-tropic HIV-1 and had a survival advantage compared to control cells ex vivo In a hu-PBL mouse study, GPI-scFv X5-transduced CD4 T cells were selected in peripheral blood and lymphoid tissues upon HIV-1 infection. Finally, GPI-scFv X5-transduced CD4 T cells, after being cotransfused with HIV-infected cells, showed significantly reduced viral loads and viral RNA copy numbers relative to CD4 cells in hu-PBL mice compared to mice with GPI-scFv AB65-transduced CD4 T cells. We conclude that GPI-scFv X5-modified CD4 T cells could potentially be used as a genetic intervention against both R5- and X4-tropic HIV-1 infections. IMPORTANCE Blocking of HIV-1 entry is one of most promising approaches for therapy. Genetic disruption of the HIV-1 coreceptor CCR5 by nucleases in T cells is under 2 clinical trials and leads to reduced viremia in patients. However, the emergence of viruses using the CXCR4 coreceptor is a concern for therapies applying single-coreceptor disruption. Here, we report that HIV-1-permissive CD4 T cells engineered with GPI-scFv X5 are resistant to R5-, X4-, or dual-tropic virus infection ex vivo In a preclinical study using hu-PBL mice, we show that CD4 T cells were protected and that GPI-scFv X5-transduced cells were selected in HIV-1-infected animals. Moreover, we show that GPI-scFv X5-transduced CD4 T cells exerted a negative effect on virus replication in vivo We conclude that GPI-scFv X5-modified CD4 T cells could potentially be used as a genetic intervention against both R5- and X4-tropic HIV-1 infections.
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HIV-1-Specific Chimeric Antigen Receptors Based on Broadly Neutralizing Antibodies. J Virol 2016; 90:6999-7006. [PMID: 27226366 DOI: 10.1128/jvi.00805-16] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 05/17/2016] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Although the use of chimeric antigen receptors (CARs) based on single-chain antibodies for gene immunotherapy of cancers is increasing due to promising recent results, the earliest CAR therapeutic trials were done for HIV-1 infection in the late 1990s. This approach utilized a CAR based on human CD4 as a binding domain and was abandoned for a lack of efficacy. The growing number of HIV-1 broadly neutralizing antibodies (BNAbs) offers the opportunity to generate novel CARs that may be more active and revisit this modality for HIV-1 immunotherapy. We used sequences from seven well-defined BNAbs varying in binding sites and generated single-chain-antibody-based CARs. These CARs included 10E8, 3BNC117, PG9, PGT126, PGT128, VRC01, and X5. Each novel CAR exhibited conformationally relevant expression on the surface of transduced cells, mediated specific proliferation and killing in response to HIV-1-infected cells, and conferred potent antiviral activity (reduction of viral replication in log10 units) to transduced CD8(+) T lymphocytes. The antiviral activity of these CARs was reproducible but varied according to the strain of virus. These findings indicated that BNAbs are excellent candidates for developing novel CARs to consider for the immunotherapeutic treatment of HIV-1. IMPORTANCE While chimeric antigen receptors (CARs) using single-chain antibodies as binding domains are growing in popularity for gene immunotherapy of cancers, the earliest human trials of CARs were done for HIV-1 infection. However, those trials failed, and the approach was abandoned for HIV-1. The only tested CAR against HIV-1 was based on the use of CD4 as the binding domain. The growing availability of HIV-1 broadly neutralizing antibodies (BNAbs) affords the opportunity to revisit gene immunotherapy for HIV-1 using novel CARs based on single-chain antibodies. Here we construct and test a panel of seven novel CARs based on diverse BNAb types and show that all these CARs are functional against HIV-1.
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Comparison of Antibody-Dependent Cell-Mediated Cytotoxicity and Virus Neutralization by HIV-1 Env-Specific Monoclonal Antibodies. J Virol 2016; 90:6127-6139. [PMID: 27122574 DOI: 10.1128/jvi.00347-16] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/16/2016] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED Although antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FL or SHIVAD8-EO ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection. IMPORTANCE This study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.
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N-terminal residues of an HIV-1 gp41 membrane-proximal external region antigen influence broadly neutralizing 2F5-like antibodies. Virol Sin 2015; 30:449-56. [PMID: 26715302 DOI: 10.1007/s12250-015-3664-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/14/2015] [Indexed: 12/11/2022] Open
Abstract
The Human immunodeficiency virus type 1 (HIV-1) gp41 membrane proximal external region (MPER) is targeted by broadly neutralizing antibodies (e.g. 2F5, 4E10, Z13e and m66.6), which makes this region a promising target for vaccine design. One strategy to elicit neutralizing antibodies against the MPER epitope is to design peptide immunogens mimicking neutralization structures. To probe 2F5-like neutralizing antibodies, two yeast-displayed antibody libraries from peripheral blood mononuclear cells from a HIV-1 patient were screened against the 2F5 epitope peptide SP62. Two 2F5-like antibodies were identified that specifically recognized SP62. However, these antibodies only weakly neutralized HIV-1 primary isolates. The epitopes recognized by these two 2F5-like antibodies include not only the 2F5 epitope (amino acids (aa) 662-667 in the MPER) but also several other residues (aa 652-655) locating at the N-terminus in SP62. Experimental results suggest that residues of SP62 adjacent to the 2F5 epitope influence the response of broadly neutralizing 2F5-like antibodies in vaccination. Our findings may aid the design of vaccine immunogens and development of therapeutics against HIV-1 infection.
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Lehmann A, Wixted JHF, Shapovalov MV, Roder H, Dunbrack RL, Robinson MK. Stability engineering of anti-EGFR scFv antibodies by rational design of a lambda-to-kappa swap of the VL framework using a structure-guided approach. MAbs 2015; 7:1058-71. [PMID: 26337947 DOI: 10.1080/19420862.2015.1088618] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Phage-display technology facilitates rapid selection of antigen-specific single-chain variable fragment (scFv) antibodies from large recombinant libraries. ScFv antibodies, composed of a VH and VL domain, are readily engineered into multimeric formats for the development of diagnostics and targeted therapies. However, the recombinant nature of the selection strategy can result in VH and VL domains with sub-optimal biophysical properties, such as reduced thermodynamic stability and enhanced aggregation propensity, which lead to poor production and limited application. We found that the C10 anti-epidermal growth factor receptor (EGFR) scFv, and its affinity mutant, P2224, exhibit weak production from E. coli. Interestingly, these scFv contain a fusion of lambda3 and lambda1 V-region (LV3 and LV1) genes, most likely the result of a PCR aberration during library construction. To enhance the biophysical properties of these scFvs, we utilized a structure-based approach to replace and redesign the pre-existing framework of the VL domain to one that best pairs with the existing VH. We describe a method to exchange lambda sequences with a more stable kappa3 framework (KV3) within the VL domain that incorporates the original lambda DE-loop. The resulting scFvs, C10KV3_LV1DE and P2224KV3_LV1DE, are more thermodynamically stable and easier to produce from bacterial culture. Additionally, C10KV3_LV1DE and P2224KV3_LV1DE retain binding affinity to EGFR, suggesting that such a dramatic framework swap does not significantly affect scFv binding. We provide here a novel strategy for redesigning the light chain of problematic scFvs to enhance their stability and therapeutic applicability.
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Affiliation(s)
- Andreas Lehmann
- a Molecular Therapeutics Program, Fox Chase Cancer Center , Philadelphia , PA.,b Current address: Biogen , Cambridge MA
| | | | - Maxim V Shapovalov
- a Molecular Therapeutics Program, Fox Chase Cancer Center , Philadelphia , PA
| | - Heinrich Roder
- a Molecular Therapeutics Program, Fox Chase Cancer Center , Philadelphia , PA
| | - Roland L Dunbrack
- a Molecular Therapeutics Program, Fox Chase Cancer Center , Philadelphia , PA
| | - Matthew K Robinson
- a Molecular Therapeutics Program, Fox Chase Cancer Center , Philadelphia , PA
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Bashir T, Patgaonkar M, Kumar C S, Pasi A, Reddy KVR. HbAHP-25, an In-Silico Designed Peptide, Inhibits HIV-1 Entry by Blocking gp120 Binding to CD4 Receptor. PLoS One 2015; 10:e0124839. [PMID: 25915507 PMCID: PMC4411102 DOI: 10.1371/journal.pone.0124839] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 03/18/2015] [Indexed: 11/18/2022] Open
Abstract
Human Immunodeficiency Virus (HIV-1) poses a serious threat to the developing world and sexual transmission continues to be the major source of new infections. Therefore, the development of molecules, which prevent new HIV-1 infections, is highly warranted. In the present study, a panel of human hemoglobin (Hb)-α subunit derived peptides and their analogues, with an ability to bind gp120, were designed in-silico and their anti-HIV-1 activity was evaluated. Of these peptides, HbAHP-25, an analogue of Hb-α derived peptide, demonstrated significant anti-HIV-1 activity. HbAHP-25 was found to be active against CCR5-tropic HIV-1 strains (ADA5 and BaL) and CXCR4-tropic HIV-1 strains (IIIB and NL4-3). Surface plasmon resonance (SPR) and ELISA revealed direct interaction between HbAHP-25 and HIV-1 envelope protein, gp120. The peptide prevented binding of CD4 to gp120 and blocked subsequent steps leading to entry and/or fusion or both. Anti-HIV activity of HbAHP-25 appeared to be specific as it failed to inhibit the entry of HIV-1 pseudotyped virus (HIV-1 VSV). Further, HbAHP-25 was found to be non-cytotoxic to TZM-bl cells, VK2/E6E7 cells, CEM-GFP cells and PBMCs, even at higher concentrations. Moreover, HbAHP-25 retained its anti-HIV activity in presence of seminal plasma and vaginal fluid. In brief, the study identified HbAHP-25, a novel anti-HIV peptide, which directly interacts with gp120 and thus has a potential to inhibit early stages of HIV-1 infection.
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Affiliation(s)
- Tahir Bashir
- Division of Molecular Immunology and Microbiology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, Mumbai, India
| | - Mandar Patgaonkar
- Department of Biological Sciences, Tata Institute for Fundamental Research, Mumbai, India
| | - Selvaa Kumar C
- Department of Bioinformatics, School of Biotechnology and Bioinformatics, D.Y. Patil University, Navi Mumbai, India
| | - Achhelal Pasi
- Division of Molecular Immunology and Microbiology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, Mumbai, India
| | - Kudumula Venkata Rami Reddy
- Division of Molecular Immunology and Microbiology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, Mumbai, India
- * E-mail:
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19
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Carrillo J, Molinos-Albert LM, de la Concepción MLR, Marfil S, García E, Derking R, Sanders RW, Clotet B, Blanco J. Gp120/CD4 blocking antibodies are frequently elicited in ART-naïve chronically HIV-1 infected individuals. PLoS One 2015; 10:e0120648. [PMID: 25803681 PMCID: PMC4372395 DOI: 10.1371/journal.pone.0120648] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/25/2015] [Indexed: 11/24/2022] Open
Abstract
Antibodies with the ability to block the interaction of HIV-1 envelope glycoprotein (Env) gp120 with CD4, including those overlapping the CD4 binding site (CD4bs antibodies), can protect from infection by HIV-1, and their elicitation may be an interesting goal for any vaccination strategy. To identify gp120/CD4 blocking antibodies in plasma samples from HIV-1 infected individuals we have developed a competitive flow cytometry-based functional assay. In a cohort of treatment-naïve chronically infected patients, we showed that gp120/CD4 blocking antibodies were frequently elicited (detected in 97% plasma samples) and correlated with binding to trimeric HIV-1 envelope glycoproteins. However, no correlation was observed between functional CD4 binding blockade data and titer of CD4bs antibodies determined by ELISA using resurfaced gp120 proteins. Consistently, plasma samples lacking CD4bs antibodies were able to block the interaction between gp120 and its receptor, indicating that antibodies recognizing other epitopes, such as PGT126 and PG16, can also play the same role. Antibodies blocking CD4 binding increased over time and correlated positively with the capacity of plasma samples to neutralize the laboratory-adapted NL4.3 and BaL virus isolates, suggesting their potential contribution to the neutralizing workforce of plasma in vivo. Determining whether this response can be boosted to achieve broadly neutralizing antibodies may provide valuable information for the design of new strategies aimed to improve the anti-HIV-1 humoral response and to develop a successful HIV-1 vaccine.
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Affiliation(s)
- Jorge Carrillo
- Institut de Recerca de la SIDA-IrsiCaixa-HIVACAT, Badalona, Barcelona, Spain
- * E-mail:
| | - Luis Manuel Molinos-Albert
- Institut de Recerca de la SIDA-IrsiCaixa-HIVACAT, Badalona, Barcelona, Spain
- Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
| | | | - Silvia Marfil
- Institut de Recerca de la SIDA-IrsiCaixa-HIVACAT, Badalona, Barcelona, Spain
| | - Elisabet García
- Institut de Recerca de la SIDA-IrsiCaixa-HIVACAT, Badalona, Barcelona, Spain
| | - Ronald Derking
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Rogier W. Sanders
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Bonaventura Clotet
- Institut de Recerca de la SIDA-IrsiCaixa-HIVACAT, Badalona, Barcelona, Spain
- Universitat Autònoma de Barcelona, Cerdanyola del Vallés, Barcelona, Spain
- Universitat de Vic-Central de Catalunya, UVIC-UCC, Vic, Barcelona, Spain
- Fundació Lluita contra la SIDA, Badalona, Barcelona, Spain
| | - Julià Blanco
- Institut de Recerca de la SIDA-IrsiCaixa-HIVACAT, Badalona, Barcelona, Spain
- Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
- Universitat Autònoma de Barcelona, Cerdanyola del Vallés, Barcelona, Spain
- Universitat de Vic-Central de Catalunya, UVIC-UCC, Vic, Barcelona, Spain
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Ramirez Valdez KP, Kuwata T, Maruta Y, Tanaka K, Alam M, Yoshimura K, Matsushita S. Complementary and synergistic activities of anti-V3, CD4bs and CD4i antibodies derived from a single individual can cover a wide range of HIV-1 strains. Virology 2014; 475:187-203. [PMID: 25486586 DOI: 10.1016/j.virol.2014.11.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/17/2014] [Accepted: 11/10/2014] [Indexed: 10/24/2022]
Abstract
Antibodies with modest neutralizing activity and narrow breadth are commonly elicited in HIV-1. Here, we evaluated the complementary and synergistic activities of a set of monoclonal antibodies (MAb) isolated from a single patient, directed to V3, CD4 binding site (CD4bs), and CD4 induced (CD4i) epitopes. Despite low somatic hypermutation percentages in the variable regions, these MAbs covered viral strains from subtypes B, C, A and CRF01_AE and transmitted/founder viruses in terms of binding, neutralizing and antibody-dependent cell-mediated cytotoxicity (ADCC) activities. In addition, a combination of the anti-V3 and CD4bs MAbs showed a synergistic effect over the neutralization of HIV-1JR-FL. A humoral response from a single patient covered a wide range of viruses by complementary and synergistic activities of antibodies with different specificities. Inducing a set of narrow neutralizing antibodies, easier to induce than the broadly neutralizing antibodies, could be a strategy for developing an effective vaccine against HIV-1.
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Affiliation(s)
| | - Takeo Kuwata
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Yasuhiro Maruta
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Kazuki Tanaka
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Muntasir Alam
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Kazuhisa Yoshimura
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, Kumamoto, Japan; AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shuzo Matsushita
- Matsushita Project Laboratory, Center for AIDS Research, Kumamoto University, Kumamoto, Japan.
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McCoy LE, Groppelli E, Blanchetot C, de Haard H, Verrips T, Rutten L, Weiss RA, Jolly C. Neutralisation of HIV-1 cell-cell spread by human and llama antibodies. Retrovirology 2014; 11:83. [PMID: 25700025 PMCID: PMC4189184 DOI: 10.1186/s12977-014-0083-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/08/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Direct cell-cell spread of HIV-1 is a very efficient mode of viral dissemination, with increasing evidence suggesting that it may pose a considerable challenge to controlling viral replication in vivo. Much current vaccine research involves the study of broadly neutralising antibodies (bNabs) that arise during natural infection with the aims of eliciting such antibodies by vaccination or incorporating them into novel therapeutics. However, whether cell-cell spread of HIV-1 can be effectively targeted by bNabs remains unclear, and there is much interest in identifying antibodies capable of efficiently neutralising virus transmitted by cell-cell contact. RESULTS In this study we have tested a panel of bNAbs for inhibition of cell-cell spread, including some not previously evaluated for inhibition of this mode of HIV-1 transmission. We found that three CD4 binding site antibodies, one from an immunised llama (J3) and two isolated from HIV-1-positive patients (VRC01 and HJ16) neutralised cell-cell spread between T cells, while antibodies specific for glycan moieties (2G12, PG9, PG16) and the MPER (2F5) displayed variable efficacy. Notably, while J3 displayed a high level of potency during cell-cell spread we found that the small size of the llama heavy chain-only variable region (VHH) J3 is not required for efficient neutralisation since recombinant J3 containing a full-length human heavy chain Fc domain was significantly more potent. J3 and J3-Fc also neutralised cell-cell spread of HIV-1 from primary macrophages to CD4+ T cells. CONCLUSIONS In conclusion, while bNabs display variable efficacy at preventing cell-cell spread of HIV-1, we find that some CD4 binding site antibodies can inhibit this mode of HIV-1 dissemination and identify the recently described llama antibody J3 as a particularly potent inhibitor. Effective neutralisation of cell-cell spread between physiologically relevant cell types by J3 and J3-Fc supports the development of VHH J3 nanobodies for therapeutic or prophylactic applications.
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Abstract
Monoclonal antibodies have been successfully used for the therapy of various diseases. However, because of their large size (∼150 kD), many limitations have also been found during their development and manufacture. The use of antibody fragments with smaller sizes is one of the strategies to overcome these limitations. Antibody heavy chain variable domains (12∼15 kD) have already been widely used for the development of variable domain-based engineered antibody domains (termed V-based eAds) targeting different antigens. Recently, antibody second heavy chain constant domains (∼12 kD) were proposed as novel scaffolds for library construction and selection of specific binders termed constant domain-based eAds (C-based eAds) as novel candidate therapeutics, which might also confer additional crystallizable fragment functions. Both V- and C-based eAds are promising therapeutic candidates. This review summarizes progress in the development of eAds, and discusses the related patents and their potential applications.
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Ringe R, Bhattacharya J. Preventive and therapeutic applications of neutralizing antibodies to Human Immunodeficiency Virus Type 1 (HIV-1). THERAPEUTIC ADVANCES IN VACCINES 2014; 1:67-80. [PMID: 24757516 DOI: 10.1177/2051013613494534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The development of a preventive vaccine to neutralize the highly variable and antigenically diverse human immunodeficiency virus type 1 (HIV-1) has been an indomitable goal. The recent discovery of a number of cross-neutralizing and potent monoclonal antibodies from elite neutralizers has provided important insights in this field. Neutralizing antibodies (NAbs) are useful in identifying neutralizing epitopes of vaccine utility and for understanding the mechanism of potent and broad cross-neutralization thus providing a modality of preventive and therapeutic value. In this article we review the current understanding on the potential use of broadly neutralizing antibodies (bNAbs) in their full-length IgG structure, engineered domain antibody or bispecific versions towards preventive and therapeutic applications. The potential implications of NAbs are discussed in the light of the recent developments as key components in vaccination against HIV-1. The development of a vaccine immunogen which elicits bNAbs and confers protective immunity remains a real challenge.
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Affiliation(s)
- Rajesh Ringe
- Weill Medical College of Cornell University, New York, NY, USA
| | - Jayanta Bhattacharya
- International AIDS Vaccine Initiative (IAVI), THSTI-IAVI HVTR Laboratory, Translational Health Science and Technology Institute (THSTI), Gurgaon-122016, Haryana, India
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Yang L, Wang P. Passive immunization against HIV/AIDS by antibody gene transfer. Viruses 2014; 6:428-47. [PMID: 24473340 PMCID: PMC3939464 DOI: 10.3390/v6020428] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 01/06/2014] [Accepted: 01/10/2014] [Indexed: 12/12/2022] Open
Abstract
Despite tremendous efforts over the course of many years, the quest for an effective HIV vaccine by the classical method of active immunization remains largely elusive. However, two recent studies in mice and macaques have now demonstrated a new strategy designated as Vectored ImmunoProphylaxis (VIP), which involves passive immunization by viral vector-mediated delivery of genes encoding broadly neutralizing antibodies (bnAbs) for in vivo expression. Robust protection against virus infection was observed in preclinical settings when animals were given VIP to express monoclonal neutralizing antibodies. This unorthodox approach raises new promise for combating the ongoing global HIV pandemic. In this article, we survey the status of antibody gene transfer, review the revolutionary progress on isolation of extremely bnAbs, detail VIP experiments against HIV and its related virus conduced in humanized mice and macaque monkeys, and discuss the pros and cons of VIP and its opportunities and challenges towards clinical applications to control HIV/AIDS endemics.
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Affiliation(s)
- Lili Yang
- Department of Microbiology, Immunology and Molecular Genetics, Eli & Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California at Los Angeles, Los Angeles, CA 90095, USA.
| | - Pin Wang
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
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25
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Weiss-Ottolenghi Y, Gershoni JM. Profiling the IgOme: meeting the challenge. FEBS Lett 2014; 588:318-25. [PMID: 24239539 PMCID: PMC7094557 DOI: 10.1016/j.febslet.2013.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 02/03/2023]
Abstract
The entire repertoire of antibodies in our serum, the IgOme, is a historical record of our past experiences and a reflection of our immune status at any given moment. Understanding the dynamics of the IgOme and how the diversity and specificities of serum antibodies change in response to disease and maintenance of homeostasis can directly impact the ability to design and develop novel vaccines, diagnostics and therapeutics. Here we review both direct and indirect methodologies that are being developed to map the complexity and specificities of the antibodies in polyclonal serum - the IgOme.
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Affiliation(s)
- Yael Weiss-Ottolenghi
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Jonathan M Gershoni
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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26
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Specific sequences commonly found in the V3 domain of HIV-1 subtype C isolates affect the overall conformation of native Env and induce a neutralization-resistant phenotype independent of V1/V2 masking. Virology 2013; 448:363-74. [PMID: 24314667 DOI: 10.1016/j.virol.2013.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 08/23/2013] [Accepted: 10/03/2013] [Indexed: 11/21/2022]
Abstract
Primary HIV-1 isolates are relatively resistant to neutralization by antibodies commonly induced after infection or vaccination. This is generally attributed to masking of sensitive epitopes by the V1/V2 domain and/or glycans situated at various positions in Env. Here we identified a novel masking effect mediated by subtype C-specific V3 sequences that contributes to the V1/V2-independent and glycan-independent neutralization resistance of chimeric and primary Envs to antibodies directed against multiple neutralization domains. Positions at several conserved charged and hydrophobic sites in the V3 crown and stem were also shown to affect neutralization phenotype. These results indicated that substitutions typically present in subtype C and related V3 sequences influence the overall conformation of native Env in a way that occludes multiple neutralization targets located both within and outside of the V3 domain, and may reflect an alternative mechanism for neutralization resistance that is particularly active in subtype C and related isolates.
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The potential of the human immune system to develop broadly neutralizing HIV-1 antibodies: implications for vaccine development. AIDS 2013; 27:2529-39. [PMID: 24100711 PMCID: PMC3815086 DOI: 10.1097/qad.0000000000000015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES AND DESIGN Developing an effective HIV-1 vaccine that elicits broadly neutralizing HIV-1 human antibodies (bnAbs) remains a challenging goal. Extensive studies on HIV-1 have revealed various strategies employed by the virus to escape host immune surveillance. Here, we investigated the human antibody gene repertoires of uninfected and HIV-1-infected individuals at genomic DNA (gDNA) and cDNA levels by deep sequencing followed by high-throughput sequence analysis to determine the frequencies of putative germline antibody genes of known HIV-1 monoclonal bnAbs (bnmAbs). METHODS Combinatorial gDNA and cDNA antibody libraries were constructed using the gDNAs and mRNAs isolated from uninfected and HIV-1-infected human peripheral blood mononuclear cells (PBMCs). All libraries were deep sequenced and sequences analysed using IMGT/HighV-QUEST software (http://imgt.org/HighV-QUEST/index.action). The frequencies of putative germline antibodies of known bnmAbs in the gDNA and cDNA libraries were determined. RESULTS AND CONCLUSION The human gDNA antibody libraries were more diverse in heavy and light chain V-gene lineage usage than the cDNA libraries, indicating that the human gDNA antibody gene repertoires may have more potential than the cDNA repertoires to develop HIV-1 bnAbs. The frequencies of the heavy and kappa and lambda light chain variable regions with identical V(D)J recombinations to known HIV-1 bnmAbs were extremely low in human antibody gene repertoires. However, we found relatively high frequencies of the heavy and kappa and lambda light chain variable regions that used the same V-genes and had the same CDR3 lengths as known HIV-1 bnmAbs regardless of (D)J-gene usage. B-cells bearing B-cell receptors of such heavy and kappa and lambda light chain variable regions may be stimulated to induce HIV-1 bnAbs.
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28
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Wan C, Sun J, Chen W, Yuan X, Chong H, Prabakaran P, Dimitrov DS, He Y. Epitope mapping of M36, a human antibody domain with potent and broad HIV-1 inhibitory activity. PLoS One 2013; 8:e66638. [PMID: 23776690 PMCID: PMC3679054 DOI: 10.1371/journal.pone.0066638] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 05/08/2013] [Indexed: 01/01/2023] Open
Abstract
M36 is the first member of a novel class of potent HIV-1 entry inhibitors based on human engineered antibody domains (eAds). It exhibits broad inhibitory activity suggesting that its CD4-induced epitope is highly conserved. Here, we describe fine mapping of its epitope by using several approaches. First, a panel of mimotopes was affinity-selected from a random peptide library and potential m36-binding residues were computationally predicted. Second, homology modeling of m36 and molecular docking of m36 onto gp120 revealed potentially important residues in gp120-m36 interactions. Third, the predicted contact residues were verified by site-directed mutagenesis. Taken together, m36 epitope comprising three discontinuous sites including six key gp120 residues (Site C1: Thr123 and Pro124; Site C3: Glu370 and Ile371; Site C4: Met426 and Trp427) were identified. In the 3D structure of gp120, the sites C1 and C4 are located in the bridging sheet and the site C3 is within the β15-α3 excursion, which play essential roles for the receptor- and coreceptor-binding and are major targets of neutralizing antibodies. Based on these results we propose a precise localization of the m36 epitope and suggest a mechanism of its broad inhibitory activity which could help in the development of novel HIV-1 therapeutics based on eAds.
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Affiliation(s)
- Chao Wan
- MOH Key Laboratory of Systems Biology of Pathogens and AIDS Research Center, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianping Sun
- MOH Key Laboratory of Systems Biology of Pathogens and AIDS Research Center, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Weizao Chen
- Protein Interactions Group, CCRNP, CCR, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
| | - Xiaohui Yuan
- MOH Key Laboratory of Systems Biology of Pathogens and AIDS Research Center, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huihui Chong
- MOH Key Laboratory of Systems Biology of Pathogens and AIDS Research Center, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ponraj Prabakaran
- Protein Interactions Group, CCRNP, CCR, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
| | - Dimiter S. Dimitrov
- Protein Interactions Group, CCRNP, CCR, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
| | - Yuxian He
- MOH Key Laboratory of Systems Biology of Pathogens and AIDS Research Center, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail:
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29
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Qiao C, Lv M, Li X, Geng J, Li Y, Zhang J, Lin Z, Feng J, Shen B. Affinity maturation of antiHER2 monoclonal antibody MIL5 using an epitope-specific synthetic phage library by computational design. J Biomol Struct Dyn 2013; 31:511-21. [DOI: 10.1080/07391102.2012.706073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Abstract
Most neutralizing antibodies act at the earliest steps of viral infection and block interaction of the virus with cellular receptors to prevent entry into host cells. The inability to induce neutralizing antibodies to HIV has been a major obstacle to HIV vaccine research since the early days of the epidemic. However, in the past three years, the definition of a neutralizing antibody against HIV has been revolutionized by the isolation of extremely broad and potent neutralizing antibodies from HIV-infected individuals. Considerable hurdles remain for inducing neutralizing antibodies to a protective level after immunization. Meanwhile, novel technologies to bypass the induction of antibodies are being explored to provide prophylactic antibody-based interventions. This review addresses the challenge of inducing HIV neutralizing antibodies upon immunization and considers notable recent advances in the field. A greater understanding of the successes and failures for inducing a neutralizing response upon immunization is required to accelerate the development of an effective HIV vaccine.
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Affiliation(s)
- Laura E McCoy
- Wohl Virion Centre, Division of Infection and Immunity, University College London, London WC1E 6BT, England, UK
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31
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Neutralizing antibody responses in macaques induced by human immunodeficiency virus type 1 monovalent or trivalent envelope glycoproteins. PLoS One 2013; 8:e59803. [PMID: 23533650 PMCID: PMC3606129 DOI: 10.1371/journal.pone.0059803] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 02/19/2013] [Indexed: 01/16/2023] Open
Abstract
A major goal of efforts to develop a vaccine to prevent HIV-1 infection is induction of broadly cross-reactive neutralizing antibodies (bcnAb). In previous studies we have demonstrated induction of neutralizing antibodies that did cross-react among multiple primary and laboratory strains of HIV-1, but neutralized with limited potency. In the present study we tested the hypothesis that immunization with multiple HIV-1 envelope glycoproteins (Envs) would result in a more potent and cross-reactive neutralizing response. One Env, CM243(N610Q), was selected on the basis of studies of the effects of single and multiple mutations of the four gp41 glycosylation sites. The other two Envs included R2 (subtype B) and 14/00/4 (subtype F), both of which were obtained from donors with bcnAb. Rhesus monkeys were immunized using a prime boost regimen as in previous studies. Individual groups of monkeys were immunized with either one of the three Envs or all three. The single N610Q and N615Q mutations of CM243 Env did not disrupt protein secretion, processing into, or reactivity with mAbs, unlike other single or multiple deglycosylation mutations. In rabbit studies the N610Q mutation alone or in combination was associated with an enhanced neutralizing response against homologous and heterologous subtype E viruses. In the subsequent monkey study the response induced by the R2 Env regimen was equivalent to the trivalent regimen and superior to the other monovalent regimens against the virus panel used for testing. The 14/00/4 Env induced responses superior to CM243(N610Q). The results indicate that elimination of the glycosylation site near the gp41 loop results in enhanced immunogenicity, but that immunization of monkeys with these three distinct Envs was not more immunogenic than with one.
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32
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Leaman DP, Zwick MB. Increased functional stability and homogeneity of viral envelope spikes through directed evolution. PLoS Pathog 2013; 9:e1003184. [PMID: 23468626 PMCID: PMC3585149 DOI: 10.1371/journal.ppat.1003184] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
The functional HIV-1 envelope glycoprotein (Env) trimer, the target of anti-HIV-1 neutralizing antibodies (Abs), is innately labile and coexists with non-native forms of Env. This lability and heterogeneity in Env has been associated with its tendency to elicit non-neutralizing Abs. Here, we use directed evolution to overcome instability and heterogeneity of a primary Env spike. HIV-1 virions were subjected to iterative cycles of destabilization followed by replication to select for Envs with enhanced stability. Two separate pools of stable Env variants with distinct sequence changes were selected using this method. Clones isolated from these viral pools could withstand heat, denaturants and other destabilizing conditions. Seven mutations in Env were associated with increased trimer stability, primarily in the heptad repeat regions of gp41, but also in V1 of gp120. Combining the seven mutations generated a variant Env with superior homogeneity and stability. This variant spike moreover showed resistance to proteolysis and to dissociation by detergent. Heterogeneity within the functional population of hyper-stable Envs was also reduced, as evidenced by a relative decrease in a proportion of virus that is resistant to the neutralizing Ab, PG9. The latter result may reflect a change in glycans on the stabilized Envs. The stabilizing mutations also increased the proportion of secreted gp140 existing in a trimeric conformation. Finally, several Env-stabilizing substitutions could stabilize Env spikes from HIV-1 clades A, B and C. Spike stabilizing mutations may be useful in the development of Env immunogens that stably retain native, trimeric structure. A vaccine is needed to prevent HIV/AIDS but eliciting potent neutralizing antibodies (Abs) against primary isolates has been a major stumbling block. The target of HIV-1 neutralizing antibodies is the native envelope glycoprotein (Env) trimer that is displayed on the surface of the virus. Virion associated Env typically elicits antibodies that cannot neutralize primary viruses. However, because native Env trimers can dissociate and coexist with non-fusogenic forms of Env interpreting these results are difficult. Here, we used directed evolution to select for virions that display native Env with increased stability and homogeneity. HIV-1 virions were subjected to increasingly harsh treatments that destabilize Env trimers, and the variants that survived each treatment were expanded. We could identify seven different mutations in Env that increased its stability of function in the face of multiple destabilizing treatments. When these mutations were combined, the resulting mutant Env trimers were far more stable than the original Env protein. Incorporating trimer-stabilizing mutations into Env-based immunogens should facilitate vaccine research by mitigating the confounding effects of non-native byproducts of Env decay. A similar approach may be used on other pathogens with potential vaccine targets that are difficult to isolate and maintain in a native form.
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Affiliation(s)
- Daniel P. Leaman
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael B. Zwick
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Narayan KM, Agrawal N, Du SX, Muranaka JE, Bauer K, Leaman DP, Phung P, Limoli K, Chen H, Boenig RI, Wrin T, Zwick MB, Whalen RG. Prime-boost immunization of rabbits with HIV-1 gp120 elicits potent neutralization activity against a primary viral isolate. PLoS One 2013; 8:e52732. [PMID: 23326351 PMCID: PMC3541383 DOI: 10.1371/journal.pone.0052732] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 11/20/2012] [Indexed: 11/19/2022] Open
Abstract
Development of a vaccine for HIV-1 requires a detailed understanding of the neutralizing antibody responses that can be experimentally elicited to difficult-to-neutralize primary isolates. Rabbits were immunized with the gp120 subunit of HIV-1 JR-CSF envelope (Env) using a DNA-prime protein-boost regimen. We analyzed five sera that showed potent autologous neutralizing activity (IC50s at ∼10(3) to 10(4) serum dilution) against pseudoviruses containing Env from the primary isolate JR-CSF but not from the related isolate JR-FL. Pseudoviruses were created by exchanging each variable and constant domain of JR-CSF gp120 with that of JR-FL or with mutations in putative N-glycosylation sites. The sera contained different neutralizing activities dependent on C3 and V5, C3 and V4, or V4 regions located on the glycan-rich outer domain of gp120. All sera showed enhanced neutralizing activity toward an Env variant that lacked a glycosylation site in V4. The JR-CSF gp120 epitopes recognized by the sera are generally distinct from those of several well characterized mAbs (targeting conserved sites on Env) or other type-specific responses (targeting V1, V2, or V3 variable regions). The activity of one serum requires specific glycans that are also important for 2G12 neutralization and this serum blocked the binding of 2G12 to gp120. Our findings show that different fine specificities can achieve potent neutralization of HIV-1, yet this strong activity does not result in improved breadth.
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Affiliation(s)
- Kristin M. Narayan
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Nitish Agrawal
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Sean X. Du
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Janelle E. Muranaka
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Katherine Bauer
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Daniel P. Leaman
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Pham Phung
- Monogram Biosciences, Inc., San Francisco, California, United States of America
| | - Kay Limoli
- Monogram Biosciences, Inc., San Francisco, California, United States of America
| | - Helen Chen
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
| | - Rebecca I. Boenig
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
| | - Terri Wrin
- Monogram Biosciences, Inc., San Francisco, California, United States of America
| | - Michael B. Zwick
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America
| | - Robert G. Whalen
- Department of Infectious Diseases, Maxygen, Inc., Redwood City, California, United States of America
- Altravax, Inc., Sunnyvale, California, United States of America
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Diverse specificity and effector function among human antibodies to HIV-1 envelope glycoprotein epitopes exposed by CD4 binding. Proc Natl Acad Sci U S A 2013; 110:E69-78. [PMID: 23237851 PMCID: PMC3538257 DOI: 10.1073/pnas.1217609110] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The HIV-1 envelope glycoprotein (Env) undergoes conformational transitions consequent to CD4 binding and coreceptor engagement during viral entry. The physical steps in this process are becoming defined, but less is known about their significance as targets of antibodies potentially protective against HIV-1 infection. Here we probe the functional significance of transitional epitope exposure by characterizing 41 human mAbs specific for epitopes exposed on trimeric Env after CD4 engagement. These mAbs recognize three epitope clusters: cluster A, the gp120 face occluded by gp41 in trimeric Env; cluster B, a region proximal to the coreceptor-binding site (CoRBS) and involving the V1/V2 domain; and cluster C, the coreceptor-binding site. The mAbs were evaluated functionally by antibody-dependent, cell-mediated cytotoxicity (ADCC) and for neutralization of Tiers 1 and 2 pseudoviruses. All three clusters included mAbs mediating ADCC. However, there was a strong potency bias for cluster A, which harbors at least three potent ADCC epitopes whose cognate mAbs have electropositive paratopes. Cluster A epitopes are functional ADCC targets during viral entry in an assay format using virion-sensitized target cells. In contrast, only cluster C contained epitopes that were recognized by neutralizing mAbs. There was significant diversity in breadth and potency that correlated with epitope fine specificity. In contrast, ADCC potency had no relationship with neutralization potency or breadth for any epitope cluster. Thus, Fc-mediated effector function and neutralization coselect with specificity in anti-Env antibody responses, but the nature of selection is distinct for these two antiviral activities.
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Yu X, Duval M, Lewis C, Gawron MA, Wang R, Posner MR, Cavacini LA. Impact of IgA constant domain on HIV-1 neutralizing function of monoclonal antibody F425A1g8. THE JOURNAL OF IMMUNOLOGY 2012. [PMID: 23183895 DOI: 10.4049/jimmunol.1201469] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
With the majority of HIV infections resulting from mucosal transmission, induction of an effective mucosal immune response is thought to be pivotal in preventing transmission. HIV-specific IgA, but not IgG, has been detected in the genital tract, seminal fluid, urethral swabs, urine, and vaginal wash samples of HIV-negative sex workers and HIV-status discordant couples. Purified mucosal and plasma IgA from some individuals with highly exposed, persistently seronegative status can neutralize infection and present cross-clade neutralization activity, though present at low levels. We generated a CD4-induced human mAb, F425A1g8, and characterized the impact of its isotype variants on HIV neutralizing activity. The result showed that, in contrast to little neutralization by the F425A1g8 IgG1 in the absence of sCD4, the IgA1 variant of the Ab displayed significant independent neutralization activity against a range of HIV clade B isolates in the absence of sCD4. Studies of the neutralizing function of IgA isotypes, and the functional relationship between different antigenic epitopes and IgA Abs, may also suggest strategies for the intervention of virus transmission and spread within the mucosa of the host, as well as serve to inform the design of vaccine strategies that may be more effective at preventing mucosal transmission. This research clearly suggests that IgA isotype, because of its unique molecular structure, may play an important role in HIV neutralization.
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Affiliation(s)
- Xiaocong Yu
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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36
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Kumar R, Andrabi R, Tiwari A, Prakash SS, Wig N, Dutta D, Sankhyan A, Khan L, Sinha S, Luthra K. A novel strategy for efficient production of anti-V3 human scFvs against HIV-1 clade C. BMC Biotechnol 2012; 12:87. [PMID: 23153214 PMCID: PMC3536577 DOI: 10.1186/1472-6750-12-87] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 10/17/2012] [Indexed: 11/10/2022] Open
Abstract
Background Production of human monoclonal antibodies that exhibit broadly neutralizing activity is needed for preventing HIV-1 infection, however only a few such antibodies have been generated till date. Isolation of antibodies by the hybridoma technology is a cumbersome process with fewer yields. Further, the loss of unstable or slowly growing clones which may have unique binding specificities often occurs during cloning and propagation and the strongly positive clones are often lost. This has been avoided by the process described in this paper, wherein, by combining the strategy of EBV transformation and recombinant DNA technology, we constructed human single chain variable fragments (scFvs) against the third variable region (V3) of the clade C HIV-1 envelope. Results An antigen specific phage library of 7000 clones was constructed from the enriched V3- positive antibody secreting EBV transformed cells. By ligation of the digested scFv DNA into phagemid vector and bio panning against the HIV-1 consensus C and B V3 peptides followed by random selection of 40 clones, we identified 15 clones that showed V3 reactivity in phage ELISA. DNA fingerprinting analysis and sequencing showed that 13 out of the 15 clones were distinct. Expression of the positive clones was tested by SDS-PAGE and Western blot. All the 13 anti-V3 scFvs showed cross-reactivity against both the clade C and B V3 peptides and did not show any reactivity against other unrelated peptides in ELISA. Preliminary neutralization assays indicated varying degrees of neutralization of clade C and B viruses. EBV transformation, followed by antigen selection of lines to identify specific binders, enabled the selection of phage from un-cloned lines for scFv generation, thus avoiding the problems of hybridoma technology. Moreover, as the clones were pretested for antigen binding, a comparatively small library sufficed for the selection of a considerable number of unique antigen binding phage. After selection, the phage clones were propagated in a clonal manner. Conclusions This strategy can be efficiently used and is cost effective for the generation of diverse recombinant antibodies. This is the first study to generate anti-V3 scFvs against HIV-1 Clade C.
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Affiliation(s)
- Rajesh Kumar
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
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Mata-Fink J, Kriegsman B, Yu HX, Zhu H, Hanson MC, Irvine DJ, Wittrup KD. Rapid conformational epitope mapping of anti-gp120 antibodies with a designed mutant panel displayed on yeast. J Mol Biol 2012; 425:444-56. [PMID: 23159556 PMCID: PMC3785227 DOI: 10.1016/j.jmb.2012.11.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 11/06/2012] [Accepted: 11/07/2012] [Indexed: 11/16/2022]
Abstract
gp120 is a substrate for protein engineering both for human immunodeficiency virus (HIV) immunogen design and as a bait for isolating anti-HIV antibodies from patient samples. In this work, we describe the display of a stripped core gp120 on the yeast cell surface. Validation against a panel of neutralizing antibodies confirms that yeast-displayed gp120 presents the CD4 binding site in the correct conformation. We map the epitope of the broadly neutralizing anti-gp120 antibody VRC01 using both a random mutagenesis library and a defined mutant panel and find that the resultant epitope maps are consistent with one another and with the crystallographically identified contact residues. Mapping the VRC01-competitive antibodies b12 and b13 reveals energetic differences in their epitopes that are not obvious from existing crystal structures. These data suggest mutation sets that abrogate binding to broadly neutralizing antibodies with greater specificity than the canonical mutation D368R, useful in rapidly assessing the nature of a vaccine response.
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Affiliation(s)
- Jordi Mata-Fink
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Straightforward selection of broadly neutralizing single-domain antibodies targeting the conserved CD4 and coreceptor binding sites of HIV-1 gp120. J Virol 2012; 87:1137-49. [PMID: 23152508 DOI: 10.1128/jvi.00461-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Few broadly neutralizing antibodies targeting determinants of the HIV-1 surface envelope glycoprotein (gp120) involved in sequential binding to host CD4 and chemokine receptors have been characterized. While these epitopes show low diversity among various isolates, HIV-1 employs many strategies to evade humoral immune response toward these sensitive sites, including a carbohydrate shield, low accessibility to these buried cavities, and conformational masking. Using trimeric gp140, free or bound to a CD4 mimic, as immunogens in llamas, we selected a panel of broadly neutralizing single-domain antibodies (sdAbs) that bind to either the CD4 or the coreceptor binding site (CD4BS and CoRBS, respectively). When analyzed as monomers or as homo- or heteromultimers, the best sdAb candidates could not only neutralize viruses carrying subtype B envelopes, corresponding to the Env molecule used for immunization and selection, but were also efficient in neutralizing a broad panel of envelopes from subtypes A, C, G, CRF01_AE, and CRF02_AG, including tier 3 viruses. Interestingly, sdAb multimers exhibited a broader neutralizing activity spectrum than the parental sdAb monomers. The extreme stability and high recombinant production yield combined with their broad neutralization capacity make these sdAbs new potential microbicide candidates for HIV-1 transmission prevention.
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Selection of antibodies from synthetic antibody libraries. Arch Biochem Biophys 2012; 526:87-98. [DOI: 10.1016/j.abb.2011.12.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 12/27/2011] [Accepted: 12/30/2011] [Indexed: 11/21/2022]
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Role of human immunodeficiency virus type 1 envelope structure in the induction of broadly neutralizing antibodies. J Virol 2012; 86:13152-63. [PMID: 23015715 DOI: 10.1128/jvi.01110-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Very soon after the discovery of neutralizing antibodies (NAbs) toward human immunodeficiency virus type 1 (HIV-1) infection, it became apparent that characterization of these NAbs would be an important step in finding a cure for or a vaccine to eradicate HIV-1. Since the initial description of broadly cross-clade NAbs naturally produced in HIV-1 patients, numerous studies have described new viral targets for these antibodies. More recently, studies concerning new groups of patients able to control their viremia, such as long-term nonprogressors (LTNPs) or elite controllers, have described the generation of numerous envelope-targeted NAbs. Recent studies have marked a new stage in research on NAbs with the description of antibodies obtained from a worldwide screening of HIV-positive patients. These studies have permitted the discovery of NAb families with great potential for both neutralization and neutralization breadth, such as PG, PGT, CH, and highly active agonistic anti-CD4 binding site antibodies (HAADs), of which VRC01 and its variants are members. These antibodies are able to neutralize more than 80% of circulating strains without any autoreactivity and can be rapidly integrated into clinical trials in order to test their protective potential. In this review, we will focus on new insights into HIV-1 envelope structure and their implications for the generation of potent NAbs.
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Broadly neutralizing antibodies developed by an HIV-positive elite neutralizer exact a replication fitness cost on the contemporaneous virus. J Virol 2012; 86:12676-85. [PMID: 22973035 DOI: 10.1128/jvi.01893-12] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Approximately 1% of those infected with HIV-1 develop broad and potent serum cross-neutralizing antibody activities. It is unknown whether or not the development of such immune responses affects the replication of the contemporaneous autologous virus. Here, we defined a pathway of autologous viral escape from contemporaneous potent and broad serum neutralizing antibodies developed by an elite HIV-1-positive (HIV-1(+)) neutralizer. These antibodies potently neutralize diverse isolates from different clades and target primarily the CD4-binding site (CD4-BS) of the viral envelope glycoprotein. Viral escape required mutations in the viral envelope glycoprotein which limited the accessibility of the CD4-binding site to the autologous broadly neutralizing anti-CD4-BS antibodies but which allowed the virus to infect cells by utilizing CD4 receptors on their surface. The acquisition of neutralization resistance, however, resulted in reduced cell entry potential and slower viral replication kinetics. Our results indicate that in vivo escape from autologous broadly neutralizing antibodies exacts fitness costs to HIV-1.
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Abstract
Antibody-based therapeutics have been successfully used for the treatment of various diseases and as research tools. Several well characterized, broadly neutralizing monoclonal antibodies (bnmAbs) targeting HIV-1 envelope glycoproteins or related host cell surface proteins show sterilizing protection of animals, but they are not effective when used for therapy of an established infection in humans. Recently, a number of novel bnmAbs, engineered antibody domains (eAds), and multifunctional fusion proteins have been reported which exhibit exceptionally potent and broad neutralizing activity against a wide range of HIV-1 isolates from diverse genetic subtypes. eAds could be more effective in vivo than conventional full-size antibodies generated by the human immune system. Because of their small size (12∼15 kD), they can better access sterically restricted epitopes and penetrate densely packed tissue where HIV-1 replicates than the larger full-size antibodies. HIV-1 possesses a number of mechanisms to escape neutralization by full-size antibodies but could be less likely to develop resistance to eAds. Here, we review the in vitro and in vivo antiviral efficacies of existing HIV-1 bnmAbs, summarize the development of eAds and multispecific fusion proteins as novel types of HIV-1 inhibitors, and discuss possible strategies to generate more potent antibody-based candidate therapeutics against HIV-1, including some that could be used to eradicate the virus.
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Affiliation(s)
- Rui Gong
- Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702-1201, USA.
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McCoy LE, Quigley AF, Strokappe NM, Bulmer-Thomas B, Seaman MS, Mortier D, Rutten L, Chander N, Edwards CJ, Ketteler R, Davis D, Verrips T, Weiss RA. Potent and broad neutralization of HIV-1 by a llama antibody elicited by immunization. ACTA ACUST UNITED AC 2012; 209:1091-103. [PMID: 22641382 PMCID: PMC3371729 DOI: 10.1084/jem.20112655] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A heavy chain–only antibody isolated from a llama repeatedly immunized with trimeric HIV-1 Env neutralizes 96% of tested HIV-1 strains. Llamas (Lama glama) naturally produce heavy chain–only antibodies (Abs) in addition to conventional Abs. The variable regions (VHH) in these heavy chain–only Abs demonstrate comparable affinity and specificity for antigens to conventional immunoglobulins despite their much smaller size. To date, immunizations in humans and animal models have yielded only Abs with limited ability to neutralize HIV-1. In this study, a VHH phagemid library generated from a llama that was multiply immunized with recombinant trimeric HIV-1 envelope proteins (Envs) was screened directly for HIV-1 neutralization. One VHH, L8CJ3 (J3), neutralized 96 of 100 tested HIV-1 strains, encompassing subtypes A, B, C, D, BC, AE, AG, AC, ACD, CD, and G. J3 also potently neutralized chimeric simian-HIV strains with HIV subtypes B and C Env. The sequence of J3 is highly divergent from previous anti–HIV-1 VHH and its own germline sequence. J3 achieves broad and potent neutralization of HIV-1 via interaction with the CD4-binding site of HIV-1 Env. This study may represent a new benchmark for immunogens to be included in B cell–based vaccines and supports the development of VHH as anti–HIV-1 microbicides.
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Affiliation(s)
- Laura E McCoy
- Wohl Virion Centre, University College London, London WC1E 6BT, England, UK
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Friedman J, Alam SM, Shen X, Xia SM, Stewart S, Anasti K, Pollara J, Fouda GG, Yang G, Kelsoe G, Ferrari G, Tomaras GD, Haynes BF, Liao HX, Moody MA, Permar SR. Isolation of HIV-1-neutralizing mucosal monoclonal antibodies from human colostrum. PLoS One 2012; 7:e37648. [PMID: 22624058 PMCID: PMC3356285 DOI: 10.1371/journal.pone.0037648] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
Background Generation of potent anti-HIV antibody responses in mucosal compartments is a potential requirement of a transmission-blocking HIV vaccine. HIV-specific, functional antibody responses are present in breast milk, and these mucosal antibody responses may play a role in protection of the majority of HIV-exposed, breastfeeding infants. Therefore, characterization of HIV-specific antibodies produced by B cells in milk could guide the development of vaccines that elicit protective mucosal antibody responses. Methods We isolated B cells from colostrum of an HIV-infected lactating woman with a detectable neutralization response in milk and recombinantly produced and characterized the resulting HIV-1 Envelope (Env)-specific monoclonal antibodies (mAbs). Results The identified HIV-1 Env-specific colostrum mAbs, CH07 and CH08, represent two of the first mucosally-derived anti-HIV antibodies yet to be reported. Colostrum mAb CH07 is a highly-autoreactive, weakly-neutralizing gp140-specific mAb that binds to linear epitopes in the gp120 C5 region and gp41 fusion domain. In contrast, colostrum mAb CH08 is a nonpolyreactive CD4-inducible (CD4i) gp120-specific mAb with moderate breadth of neutralization. Conclusions These novel HIV-neutralizing mAbs isolated from a mucosal compartment provide insight into the ability of mucosal B cell populations to produce functional anti-HIV antibodies that may contribute to protection against virus acquisition at mucosal surfaces.
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Affiliation(s)
- James Friedman
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - S. Munir Alam
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Xiaoying Shen
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Shi-Mao Xia
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Shelley Stewart
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Kara Anasti
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Justin Pollara
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Genevieve G. Fouda
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Guang Yang
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States
| | - Garnett Kelsoe
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States
| | - Guido Ferrari
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Georgia D. Tomaras
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Barton F. Haynes
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Hua-Xin Liao
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - M. Anthony Moody
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
| | - Sallie R. Permar
- Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States
- * E-mail:
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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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Delhalle S, Schmit JC, Chevigné A. Phages and HIV-1: from display to interplay. Int J Mol Sci 2012; 13:4727-4794. [PMID: 22606007 PMCID: PMC3344243 DOI: 10.3390/ijms13044727] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 03/26/2012] [Accepted: 03/30/2012] [Indexed: 11/16/2022] Open
Abstract
The complex hide-and-seek game between HIV-1 and the host immune system has impaired the development of an efficient vaccine. In addition, the high variability of the virus impedes the long-term control of viral replication by small antiviral drugs. For more than 20 years, phage display technology has been intensively used in the field of HIV-1 to explore the epitope landscape recognized by monoclonal and polyclonal HIV-1-specific antibodies, thereby providing precious data about immunodominant and neutralizing epitopes. In parallel, biopanning experiments with various combinatorial or antibody fragment libraries were conducted on viral targets as well as host receptors to identify HIV-1 inhibitors. Besides these applications, phage display technology has been applied to characterize the enzymatic specificity of the HIV-1 protease. Phage particles also represent valuable alternative carriers displaying various HIV-1 antigens to the immune system and eliciting antiviral responses. This review presents and summarizes the different studies conducted with regard to the nature of phage libraries, target display mode and biopanning procedures.
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Affiliation(s)
- Sylvie Delhalle
- Laboratory of Retrovirology, CRP-Sante, 84, Val Fleuri, L-1526 Luxembourg, Luxembourg; E-Mails: (J.-C.S.); (A.C.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +352-26970211; Fax: +352-26970221
| | - Jean-Claude Schmit
- Laboratory of Retrovirology, CRP-Sante, 84, Val Fleuri, L-1526 Luxembourg, Luxembourg; E-Mails: (J.-C.S.); (A.C.)
- Service National des Maladies Infectieuses, Centre Hospitalier Luxembourg, 4, rue E. Barblé, L-1210 Luxembourg, Luxembourg
| | - Andy Chevigné
- Laboratory of Retrovirology, CRP-Sante, 84, Val Fleuri, L-1526 Luxembourg, Luxembourg; E-Mails: (J.-C.S.); (A.C.)
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Mediouni S, Watkins JD, Pierres M, Bole A, Loret EP, Baillat G. A monoclonal antibody directed against a conformational epitope of the HIV-1 trans-activator (Tat) protein neutralizes cross-clade. J Biol Chem 2012; 287:11942-50. [PMID: 22362765 DOI: 10.1074/jbc.m111.319863] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The identification of a neutralizing mAb against extracellular HIV-1 transactivator of transcription (Tat) is important for the development of an efficient HIV-1 treatment. Tat plays an essential role in HIV-1 pathogenesis, not only for HIV-1 replication but also as an extracellular toxin able to disrupt the immune system. We showed previously that immunization of rabbits with Tat Oyi, a variant cloned from an African woman who did not develop AIDS following HIV-1 infection, raised antibodies able to recognize different Tat variants. We carried out mice immunization with Tat Oyi and selected a mAb named 7G12, which had the capacity to cross-recognize heterologous Tat variants by a common three-dimensional epitope. These results highlighted that Tat variants were able to acquire a structure, in contrast to a number of studies showing Tat as an unfolded protein. mAb 7G12 also had the capacity to neutralize the biological activities of these Tat variants by blocking the cellular uptake of extracellular Tat. This is the first study using Tat Oyi to produce a mAb able to neutralize effectively activities of extracellular Tats from different HIV-1 subtypes. This mAb has an important potential in therapeutic passive immunization and could help HIV-1 infected patients to restore their immunity.
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Affiliation(s)
- Sonia Mediouni
- Equipe de Recherche Technologique 2011, Université de la Méditerranée, Faculté de Pharmacie, 27 BD Jean Moulin, 13385 Marseille Cedex 5, France
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Vanlandschoot P, Stortelers C, Beirnaert E, Ibañez LI, Schepens B, Depla E, Saelens X. Nanobodies®: New ammunition to battle viruses. Antiviral Res 2011; 92:389-407. [DOI: 10.1016/j.antiviral.2011.09.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 08/30/2011] [Accepted: 09/06/2011] [Indexed: 01/23/2023]
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Burastero SE, Frigerio B, Lopalco L, Sironi F, Breda D, Longhi R, Scarlatti G, Canevari S, Figini M, Lusso P. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4. PLoS One 2011; 6:e22081. [PMID: 21818294 PMCID: PMC3139607 DOI: 10.1371/journal.pone.0022081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 06/15/2011] [Indexed: 12/05/2022] Open
Abstract
To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ) was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.
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Affiliation(s)
- Samuele E Burastero
- Department of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy.
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Abstract
The quest for an effective and safe HIV-1 vaccine has been and still is the aspiration of many scientists and clinicians worldwide. Until recently, the hopes for an effective vaccine were thwarted by the disappointing results and early termination in September 2007 of the STEP study, which saw a subgroup of male vaccine recipients at an increased risk of HIV-1 infection, and the failure of earlier trials of vaccines based on recombinant envelope proteins to provide any level of protection. The results of the STEP study raised important questions in the field of HIV vaccines, including the use of recombinant adenovirus vectors as immunogens, the rationale for the development of T-cell-based vaccines and the development pathway for these vaccines, in terms of assessment of immunogenicity and the challenge models used. The study of neutralizing antibodies has demonstrated that the induction of high-titre, broadly neutralizing antibodies in the majority of recipients is likely to be highly problematic. However, the results of the RV144 Thai trial released in September 2009 have brought new optimism to the field. This study employed envelope-based immunogens delivered as a priming vaccination with a recombinant poxvirus vector and boosting with recombinant proteins. This regimen provided modest protection to HIV-1 infection in a low-risk population. Although the correlates of protection are currently unknown, extensive studies are underway to try to determine these. Neutralizing antibodies were not induced in the RV144 study; however, considerable titres of binding antibodies to HIV-1 viral envelope (Env) were. It is speculated that these antibodies may have provided a means of protection by a mechanism such as antibody-dependent cell-mediated cytotoxicity. In addition, no CD8+ T-cell responses were induced, but robust CD4+ T-cell responses were, and correlates of protection are being sought by analysing the quality of this aspect of the vaccine-induced immune response. The current paradigm for an optimal HIV-1 vaccine is to design immunogens and vaccination protocols that allow the induction of both broadly neutralizing humoral and broadly reactive and effective cell-mediated immunity, to act at sites of possible infection and post-infection, respectively. However, this is challenged by the results of the RV144 trial as neither of these responses were induced but modest protection was observed. Understanding the biology and immunopathology of HIV-1 early following infection, its modes of transmission and the human immune system's response to the virus should aid in the rational design of vaccines of increased efficacy.
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Affiliation(s)
- C Mee Ling Munier
- HIV Immunovirology Laboratory, St Vincent's Centre for Applied Medical Research, Sydney, New South Wales, Australia.
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