101
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Jan M, Upadhyay C, Sharma A, Hioe CE, Arora SK. Short Communication: Manα1-2Man-Binding Anti-HIV Lectins Enhance the Exposure of V2i and V3 Crown Neutralization Epitopes on the V1/V2 and V3 Hypervariable Loops of HIV-1 Envelope. AIDS Res Hum Retroviruses 2017; 33:941-945. [PMID: 28322582 DOI: 10.1089/aid.2016.0262] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
This study aimed to explore the contribution of high-mannose glycans in the masking of conserved V3 crown (GPG) and V2i epitopes on the hypervariable loops of most exposed distal surface of HIV-1 Env. Using lectins specific to Manα1-2Man residue containing Man6-9GlcNAc2 glycans extensively decorating HIV-1 Env, we found that Manα1-2Man-binding lectins enhance the exposure of these partially and transiently exposed epitopes and consequentially increase the neutralization strength of antibodies against these epitopes.
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Affiliation(s)
- Muzafar Jan
- Department of Immunopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
- Department of Infectious Diseases, Icahn School of Medicine, Mount Sinai, New York
| | - Chitra Upadhyay
- Department of Infectious Diseases, Icahn School of Medicine, Mount Sinai, New York
| | - Aman Sharma
- Department of Internal Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Catarina E. Hioe
- Department of Infectious Diseases, Icahn School of Medicine, Mount Sinai, New York
| | - Sunil K. Arora
- Department of Immunopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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102
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Moore PL, Gorman J, Doria-Rose NA, Morris L. Ontogeny-based immunogens for the induction of V2-directed HIV broadly neutralizing antibodies. Immunol Rev 2017; 275:217-229. [PMID: 28133797 PMCID: PMC5300058 DOI: 10.1111/imr.12501] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The development of a preventative HIV vaccine able to elicit broadly neutralizing antibodies (bNAbs) remains a major challenge. Antibodies that recognize the V2 region at the apex of the HIV envelope trimer are among the most common bNAb specificities during chronic infection and many exhibit remarkable breadth and potency. Understanding the developmental pathway of these antibodies has provided insights into their precursors, and the viral strains that engage them, as well as defined how such antibodies mature to acquire breadth. V2‐apex bNAbs are derived from rare precursors with long anionic CDR H3s that are often deleted in the B cell repertoire. However, longitudinal studies suggest that once engaged, these precursors contain many of the structural elements required for neutralization, and can rapidly acquire breadth through moderate levels of somatic hypermutation in response to emerging viral variants. These commonalities in the precursors and mechanism of neutralization have enabled the identification of viral strains that show enhanced reactivity for V2 precursors from multiple donors, and may form the basis of germline targeting approaches. In parallel, new structural insights into the HIV trimer, the target of these quaternary antibodies, has created invaluable new opportunities for ontogeny‐based immunogens designed to select for rare V2‐bNAb precursors, and drive them toward breadth.
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Affiliation(s)
- Penny L Moore
- Centre for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Lynn Morris
- Centre for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
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103
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Abstract
In 2009, Dimitrov's group reported that the inferred germline (iGL) forms of several HIV-1 broadly neutralizing antibodies (bNAbs) did not display measurable binding to a recombinant gp140 Env protein (derived from the dual-tropic 89.6 virus), which was efficiently recognized by the mature (somatically mutated) antibodies. At that time, a small number of bNAbs were available, but in the following years, the implementation of high-throughput B-cell isolation and sequencing assays and of screening methodologies facilitated the isolation of greater numbers of bNAbs from infected subjects. Using these newest bNAbs, and a wide range of diverse recombinant Envs, we and others confirmed the observations made by Dimitrov's group. The results from these studies created a paradigm shift in our collective thinking as to why recombinant Envs are ineffective in eliciting bNAbs and has led to the "germline-targeting" immunization approach. Here we discuss this approach in detail: what has been done so far, the advantages and limitations of the current germline-targeting immunogens and of the animal models used to test them, and we conclude with a few thoughts about future directions in this area of research.
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Affiliation(s)
- Leonidas Stamatatos
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.,Department of Global Health, University of Washington, Seattle, WA, USA
| | - Marie Pancera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Andrew T McGuire
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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104
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Bonsignori M, Liao HX, Gao F, Williams WB, Alam SM, Montefiori DC, Haynes BF. Antibody-virus co-evolution in HIV infection: paths for HIV vaccine development. Immunol Rev 2017; 275:145-160. [PMID: 28133802 PMCID: PMC5302796 DOI: 10.1111/imr.12509] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Induction of HIV-1 broadly neutralizing antibodies (bnAbs) to date has only been observed in the setting of HIV-1 infection, and then only years after HIV transmission. Thus, the concept has emerged that one path to induction of bnAbs is to define the viral and immunologic events that occur during HIV-1 infection, and then to mimic those events with a vaccine formulation. This concept has led to efforts to map both virus and antibody events that occur from the time of HIV-1 transmission to development of bnAbs. This work has revealed that a virus-antibody "arms race" occurs in which a HIV-1 transmitted/founder (TF) Env induces autologous neutralizing antibodies that can not only neutralize the TF virus but also can select virus escape mutants that in turn select affinity-matured neutralizing antibodies. From these studies has come a picture of bnAb development that has led to new insights in host-pathogen interactions and, as well, led to insight into immunologic mechanisms of control of bnAb development. Here, we review the progress to date in elucidating bnAb B cell lineages in HIV-1 infection, discuss new research leading to understanding the immunologic mechanisms of bnAb induction, and address issues relevant to the use of this information for the design of new HIV-1 sequential envelope vaccine candidates.
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Affiliation(s)
- Mattia Bonsignori
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Hua-Xin Liao
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Feng Gao
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Wilton B Williams
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - S Munir Alam
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - David C Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA.,Department of Surgery, Duke University School of Medicine, Durham, NC, USA
| | - Barton F Haynes
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA.,Department of Immunology, Duke University School of Medicine, Durham, NC, USA
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105
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Verkoczy L, Alt FW, Tian M. Human Ig knockin mice to study the development and regulation of HIV-1 broadly neutralizing antibodies. Immunol Rev 2017; 275:89-107. [PMID: 28133799 DOI: 10.1111/imr.12505] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A major challenge for HIV-1 vaccine research is developing a successful immunization approach for inducing broadly neutralizing antibodies (bnAbs). A key shortcoming in meeting this challenge has been the lack of animal models capable of identifying impediments limiting bnAb induction and ranking vaccine strategies for their ability to promote bnAb development. Since 2010, immunoglobulin knockin (KI) technology, involving inserting functional rearranged human variable exons into the mouse IgH and IgL loci has been used to express bnAbs in mice. This approach has allowed immune tolerance mechanisms limiting bnAb production to be elucidated and strategies to overcome such limitations to be evaluated. From these studies, along with the wealth of knowledge afforded by analyses of recombinant Ig-based bnAb structures, it became apparent that key functional features of bnAbs often are problematic for their elicitation in mice by classic vaccine paradigms, necessitating more iterative testing of new vaccine concepts. In this regard, bnAb KI models expressing deduced precursor V(D)J rearrangements of mature bnAbs or unrearranged germline V, D, J segments (that can be assembled into variable region exons that encode bnAb precursors), have been engineered to evaluate novel immunogens/regimens for effectiveness in driving bnAb responses. One promising approach emerging from such studies is the ability of sequentially administered, modified immunogens (designed to bind progressively more mature bnAb precursors) to initiate affinity maturation. Here, we review insights gained from bnAb KI studies regarding the regulation and induction of bnAbs, and discuss new Ig KI methodologies to manipulate the production and/or expression of bnAbs in vivo, to further facilitate vaccine-guided bnAb induction studies.
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Affiliation(s)
- Laurent Verkoczy
- Departments of Medicine and Pathology, Duke University Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Ming Tian
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Genetics, Harvard Medical School, Boston, MA, USA
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106
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Structure of Simian Immunodeficiency Virus Envelope Spikes Bound with CD4 and Monoclonal Antibody 36D5. J Virol 2017; 91:JVI.00134-17. [PMID: 28539445 DOI: 10.1128/jvi.00134-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/14/2017] [Indexed: 01/29/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1)/simian immunodeficiency virus (SIV) envelope spike (Env) mediates viral entry into host cells. The V3 loop of the gp120 component of the Env trimer contributes to the coreceptor binding site and is a target for neutralizing antibodies. We used cryo-electron tomography to visualize the binding of CD4 and the V3 loop monoclonal antibody (MAb) 36D5 to gp120 of the SIV Env trimer. Our results show that 36D5 binds gp120 at the base of the V3 loop and suggest that the antibody exerts its neutralization effect by blocking the coreceptor binding site. The antibody does this without altering the dynamics of the spike motion between closed and open states when CD4 is bound. The interaction between 36D5 and SIV gp120 is similar to the interaction between some broadly neutralizing anti-V3 loop antibodies and HIV-1 gp120. Two conformations of gp120 bound with CD4 are revealed, suggesting an intrinsic dynamic nature of the liganded Env trimer. CD4 binding substantially increases the binding of 36D5 to gp120 in the intact Env trimer, consistent with CD4-induced changes in the conformation of gp120 and the antibody binding site. Binding by MAb 36D5 does not substantially alter the proportions of the two CD4-bound conformations. The position of MAb 36D5 at the V3 base changes little between conformations, indicating that the V3 base serves as a pivot point during the transition between these two states.IMPORTANCE Glycoprotein spikes on the surfaces of SIV and HIV are the sole targets available to the immune system for antibody neutralization. Spikes evade the immune system by a combination of a thick layer of polysaccharide on the surface (the glycan shield) and movement between spike domains that masks the epitope conformation. Using SIV virions whose spikes were "decorated" with the primary cellular receptor (CD4) and an antibody (36D5) at part of the coreceptor binding site, we visualized multiple conformations trapped by the rapid freezing step, which were separated using statistical analysis. Our results show that the CD4-induced conformational dynamics of the spike enhances binding of the antibody.
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107
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Ouyang Y, Yin Q, Li W, Li Z, Kong D, Wu Y, Hong K, Xing H, Shao Y, Jiang S, Ying T, Ma L. Escape from humoral immunity is associated with treatment failure in HIV-1-infected patients receiving long-term antiretroviral therapy. Sci Rep 2017; 7:6222. [PMID: 28740221 PMCID: PMC5524822 DOI: 10.1038/s41598-017-05594-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/31/2017] [Indexed: 01/22/2023] Open
Abstract
Interindividual heterogeneity in the disease progression of HIV-1-infected patients receiving long-term antiretroviral therapy suggests that some host-related factors may have limited treatment efficacy. To understand the nature of factors contributing to treatment failure, we performed a retrospective cohort study of 45 chronically HIV-1-infected individuals sharing a similar demographics and route of infection, compared the differences between virologically suppressed (VS) and treatment failure (TF) patients with respect to clinical, immunological and virological characteristics. We found that the baseline diversity of HIV-1 env quasispecies was the major difference between VS and TF group, and higher baseline diversity in TF patients. We further predicted TF-related env mutations using a selection pressure-based approach, followed by an analysis of these mutations based on the available three-dimensional structures of gp120/gp41 or their complexes with neutralizing antibodies. Notably, almost all of the identified residues could be mapped to the epitopes of known HIV-1 neutralizing antibodies, especially the epitopes of broadly neutralizing antibodies, and these mutations tended to compromise antibody-antigen interactions. These results indicate that the escape of HIV-1 from host humoral immunity may play a direct role in TF in long-term antiretroviral-experienced patients and that based on env gene sequence of the viruses in the patients.
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Affiliation(s)
- Yabo Ouyang
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.,Beijing You'an Hospital, Capital Medical University, Beijing, China and Beijing Institute of Hepatology, Beijing, China
| | - Qianqian Yin
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Wei Li
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Zhenpeng Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Desheng Kong
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yanling Wu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Kunxue Hong
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Hui Xing
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yiming Shao
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, China. .,Lindsley F. Kimball Research Institute, New York Blood Center, New York, USA.
| | - Tianlei Ying
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, China.
| | - Liying Ma
- State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention, Beijing, China and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
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108
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F Nguyen A, S Schill M, Jian M, J LiWang P. The Effect of N-Terminal Cyclization on the Function of the HIV Entry Inhibitor 5P12-RANTES. Int J Mol Sci 2017; 18:E1575. [PMID: 28726743 PMCID: PMC5536063 DOI: 10.3390/ijms18071575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 07/12/2017] [Accepted: 07/14/2017] [Indexed: 11/30/2022] Open
Abstract
Despite effective treatment for those living with Human Immunodeficiency Virus (HIV), there are still two million new infections each year. Protein-based HIV entry inhibitors, being highly effective and specific, could be used to protect people from initial infection. One of the most promising of these for clinical use is 5P12-RANTES, a variant of the chemokine RANTES/CCL5. The N-terminal amino acid of 5P12-RANTES is glutamine (Gln; called Q0), a residue that is prone to spontaneous cyclization when at the N-terminus of a protein. It is not known how this cyclization affects the potency of the inhibitor or whether cyclization is necessary for the function of the protein, although the N-terminal region of RANTES has been shown to be critical for receptor interactions, with even small changes having a large effect. We have studied the kinetics of cyclization of 5P12-RANTES as well as N-terminal variations of the protein that either produce an identical cyclized terminus (Glu0) or that cannot similarly cyclize (Asn0, Phe0, Ile0, and Leu0). We find that the half life for N-terminal cyclization of Gln is roughly 20 h at pH 7.3 at 37 °C. However, our results show that cyclization is not necessary for the potency of this protein and that several replacement terminal amino acids produce nearly-equally potent HIV inhibitors while remaining CC chemokine receptor 5 (CCR5) antagonists. This work has ramifications for the production of active 5P12-RANTES for use in the clinic, while also opening the possibility of developing other inhibitors by varying the N-terminus of the protein.
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Affiliation(s)
- Anna F Nguyen
- Molecular Cell Biology and the Health Sciences Research Institute, University of California Merced, 5200 North Lake Rd., Merced, CA 95343, USA.
| | - Megan S Schill
- Molecular Cell Biology and the Health Sciences Research Institute, University of California Merced, 5200 North Lake Rd., Merced, CA 95343, USA.
| | - Mike Jian
- Molecular Cell Biology and the Health Sciences Research Institute, University of California Merced, 5200 North Lake Rd., Merced, CA 95343, USA.
| | - Patricia J LiWang
- Molecular Cell Biology and the Health Sciences Research Institute, University of California Merced, 5200 North Lake Rd., Merced, CA 95343, USA.
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109
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Bobyk KD, Mandadapu SR, Lohith K, Guzzo C, Bhargava A, Lusso P, Bewley CA. Design of HIV Coreceptor Derived Peptides That Inhibit Viral Entry at Submicromolar Concentrations. Mol Pharm 2017; 14:2681-2689. [PMID: 28494151 DOI: 10.1021/acs.molpharmaceut.7b00155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
HIV/AIDS continues to pose an enormous burden on global health. Current HIV therapeutics include inhibitors that target the enzymes HIV protease, reverse transcriptase, and integrase, along with viral entry inhibitors that block the initial steps of HIV infection by preventing membrane fusion or virus-coreceptor interactions. With regard to the latter, peptides derived from the HIV coreceptor CCR5 were previously shown to modestly inhibit entry of CCR5-tropic HIV strains, with a peptide containing residues 178-191 of the second extracellular loop (peptide 2C) showing the strongest inhibition. Here we use an iterative approach of amino acid scanning at positions shown to be important for binding the HIV envelope, and recombining favorable substitutions to greatly improve the potency of 2C. The most potent candidate peptides gain neutralization breadth and inhibit CXCR4 and CXCR4/CCR5-using viruses, rather than CCR5-tropic strains only. We found that gains in potency in the absence of toxicity were highly dependent on amino acid position and residue type. Using virion capture assays we show that 2C and the new peptides inhibit capture of CD4-bound HIV-1 particles by antibodies whose epitopes are located in or around variable loop 3 (V3) on gp120. Analysis of antibody binding data indicates that interactions between CCR5 ECL2-derived peptides and gp120 are localized around the base and stem of V3 more than the tip. In the absence of a high-resolution structure of gp120 bound to coreceptor CCR5, these findings may facilitate structural studies of CCR5 surrogates, design of peptidomimetics with increased potency, or use as functional probes for further study of HIV-1 gp120-coreceptor interactions.
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Affiliation(s)
- Kostyantyn D Bobyk
- Laboratory of Bioorganic Chemistry, NIDDK, NIH , Bethesda, Maryland 20892, United States
| | | | - Katheryn Lohith
- Laboratory of Bioorganic Chemistry, NIDDK, NIH , Bethesda, Maryland 20892, United States
| | - Christina Guzzo
- Laboratory of Immunoregulation, NIAID, NIH , Bethesda, Maryland 20892, United States
| | - Abhishek Bhargava
- Laboratory of Bioorganic Chemistry, NIDDK, NIH , Bethesda, Maryland 20892, United States
| | - Paolo Lusso
- Laboratory of Immunoregulation, NIAID, NIH , Bethesda, Maryland 20892, United States
| | - Carole A Bewley
- Laboratory of Bioorganic Chemistry, NIDDK, NIH , Bethesda, Maryland 20892, United States
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110
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Conformational Heterogeneity of the HIV Envelope Glycan Shield. Sci Rep 2017; 7:4435. [PMID: 28667249 PMCID: PMC5493700 DOI: 10.1038/s41598-017-04532-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/16/2017] [Indexed: 01/08/2023] Open
Abstract
To better understand the conformational properties of the glycan shield covering the surface of the HIV gp120/gp41 envelope (Env) trimer, and how the glycan shield impacts the accessibility of the underlying protein surface, we performed enhanced sampling molecular dynamics (MD) simulations of a model glycosylated HIV Env protein and related systems. Our simulation studies revealed a conformationally heterogeneous glycan shield with a network of glycan-glycan interactions more extensive than those observed to date. We found that partial preorganization of the glycans potentially favors binding by established broadly neutralizing antibodies; omission of several specific glycans could increase the accessibility of other glycans or regions of the protein surface to antibody or CD4 receptor binding; the number of glycans that can potentially interact with known antibodies is larger than that observed in experimental studies; and specific glycan conformations can maximize or minimize interactions with individual antibodies. More broadly, the enhanced sampling MD simulations described here provide a valuable tool to guide the engineering of specific Env glycoforms for HIV vaccine design.
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111
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Orwenyo J, Cai H, Giddens J, Amin MN, Toonstra C, Wang LX. Systematic Synthesis and Binding Study of HIV V3 Glycopeptides Reveal the Fine Epitopes of Several Broadly Neutralizing Antibodies. ACS Chem Biol 2017; 12:1566-1575. [PMID: 28414420 DOI: 10.1021/acschembio.7b00319] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A class of new glycan-reactive broadly neutralizing antibodies represented by PGT121, 10-1074, and PGT128 has recently been discovered that targets specific N-glycans and the peptide region around the V3 domain. However, the glycan specificity and fine epitopes of these bNAbs remain to be further defined. We report here a systematic chemoenzymatic synthesis of homogeneous V3 glycopeptides derived from the HIV-1 JR-FL strain carrying defined N-glycans at N332, N301, and N295 sites. Antibody binding studies revealed that both the nature and site of glycosylation in the context of the V3 domain were critical for high-affinity binding. It was found that antibody PGT128 exhibited specificity for high-mannose N-glycan with glycosylation site promiscuity, PGT121 showed binding specificity for glycopeptide carrying a sialylated N-glycan at N301 site, and 10-1074 was specific for glycopeptide carrying a high-mannose N-glycan at N332 site. The synthesis and binding studies permit a detailed assessment of the glycan specificity and the requirement of peptide in the context of antibody-antigen recognition. The identified glycopeptides can be used as potential templates for HIV vaccine design.
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Affiliation(s)
- Jared Orwenyo
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States
| | - Hui Cai
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States
| | - John Giddens
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States
| | - Mohammed N. Amin
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States
| | - Christian Toonstra
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States
| | - Lai-Xi Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States
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112
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Lee JH, Andrabi R, Su CY, Yasmeen A, Julien JP, Kong L, Wu NC, McBride R, Sok D, Pauthner M, Cottrell CA, Nieusma T, Blattner C, Paulson JC, Klasse PJ, Wilson IA, Burton DR, Ward AB. A Broadly Neutralizing Antibody Targets the Dynamic HIV Envelope Trimer Apex via a Long, Rigidified, and Anionic β-Hairpin Structure. Immunity 2017; 46:690-702. [PMID: 28423342 PMCID: PMC5400778 DOI: 10.1016/j.immuni.2017.03.017] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/23/2017] [Accepted: 03/24/2017] [Indexed: 01/16/2023]
Abstract
Broadly neutralizing antibodies (bnAbs) to HIV delineate vaccine targets and are prophylactic and therapeutic agents. Some of the most potent bnAbs target a quaternary epitope at the apex of the surface HIV envelope (Env) trimer. Using cryo-electron microscopy, we solved the atomic structure of an apex bnAb, PGT145, in complex with Env. We showed that the long anionic HCDR3 of PGT145 penetrated between glycans at the trimer 3-fold axis, to contact peptide residues from all three Env protomers, and thus explains its highly trimer-specific nature. Somatic hypermutation in the other CDRs of PGT145 were crucially involved in stabilizing the structure of the HCDR3, similar to bovine antibodies, to aid in recognition of a cluster of conserved basic residues hypothesized to facilitate trimer disassembly during viral entry. Overall, the findings exemplify the creative solutions that the human immune system can evolve to recognize a conserved motif buried under a canopy of glycans.
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Affiliation(s)
- Jeong Hyun Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Raiees Andrabi
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ching-Yao Su
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Anila Yasmeen
- Weill Medical College of Cornell University, New York, New York 10065, USA
| | - Jean-Philippe Julien
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Program in Molecular Structure and Function, Hospital for Sick Children Research Institute, and Departments of Biochemistry and Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Leopold Kong
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Nicholas C Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ryan McBride
- Department of Cell and Molecular Biology and Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Devin Sok
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Matthias Pauthner
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Christopher A Cottrell
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Travis Nieusma
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Claudia Blattner
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - James C Paulson
- Department of Cell and Molecular Biology and Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Per Johan Klasse
- Weill Medical College of Cornell University, New York, New York 10065, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Dennis R Burton
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of MGH, MIT and Harvard, Boston, MA 02139, USA.
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, International AIDS Vaccine Initiative Neutralizing Antibody Center and Collaboration for AIDS Vaccine Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Wang H, Gristick HB, Scharf L, West AP, Galimidi RP, Seaman MS, Freund NT, Nussenzweig MC, Bjorkman PJ. Asymmetric recognition of HIV-1 Envelope trimer by V1V2 loop-targeting antibodies. eLife 2017; 6. [PMID: 28548638 PMCID: PMC5472438 DOI: 10.7554/elife.27389] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 05/24/2017] [Indexed: 11/25/2022] Open
Abstract
The HIV-1 envelope (Env) glycoprotein binds to host cell receptors to mediate membrane fusion. The prefusion Env trimer is stabilized by V1V2 loops that interact at the trimer apex. Broadly neutralizing antibodies (bNAbs) against V1V2 loops, exemplified by PG9, bind asymmetrically as a single Fab to the apex of the symmetric Env trimer using a protruding CDRH3 to penetrate the Env glycan shield. Here we characterized a distinct mode of V1V2 epitope recognition by the new bNAb BG1 in which two Fabs bind asymmetrically per Env trimer using a compact CDRH3. Comparisons between cryo-EM structures of Env trimer complexed with BG1 (6.2 Å resolution) and PG9 (11.5 Å resolution) revealed a new V1V2-targeting strategy by BG1. Analyses of the EM structures provided information relevant to vaccine design including molecular details for different modes of asymmetric recognition of Env trimer and a binding model for BG1 recognition of V1V2 involving glycan flexibility. DOI:http://dx.doi.org/10.7554/eLife.27389.001
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Affiliation(s)
- Haoqing Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Harry B Gristick
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Louise Scharf
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Anthony P West
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Rachel P Galimidi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | | | - Natalia T Freund
- Laboratory of Molecular Immunology, The Rockefeller University, New York, United States
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, United States
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
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114
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Hsieh FL, Higgins MK. The structure of a LAIR1-containing human antibody reveals a novel mechanism of antigen recognition. eLife 2017; 6. [PMID: 28527239 PMCID: PMC5459573 DOI: 10.7554/elife.27311] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/08/2017] [Indexed: 01/11/2023] Open
Abstract
Antibodies are critical components of the human adaptive immune system, providing versatile scaffolds to display diverse antigen-binding surfaces. Nevertheless, most antibodies have similar architectures, with the variable immunoglobulin domains of the heavy and light chain each providing three hypervariable loops, which are varied to generate diversity. The recent identification of a novel class of antibody in humans from malaria endemic regions of Africa was therefore surprising as one hypervariable loop contains the entire collagen-binding domain of human LAIR1. Here, we present the structure of the Fab fragment of such an antibody. We show that its antigen-binding site has adopted an architecture that positions LAIR1, while itself being occluded. This therefore represents a novel means of antigen recognition, in which the Fab fragment of an antibody acts as an adaptor, linking a human protein insert with antigen-binding potential to the constant antibody regions which mediate immune cell recruitment. DOI:http://dx.doi.org/10.7554/eLife.27311.001 When bacteria, viruses or parasites invade the human body, the immune system responds by producing proteins called antibodies. Antibodies recognize and bind to molecules (known as antigens) on the surface of the invaders. This binding can either neutralize the invader directly or trigger signals that cause other parts of the immune system to destroy it. Our blood contains a huge range of different antibody molecules that each bind to a different antigen. This is despite most human antibodies having the same basic shape and structure. Six loops, known as complementarity determining regions (CDRs), emerge from the surface of the antibody to form the surface that recognizes the antigen. However, variations in the structure of the loops alter this surface enough to allow different antibodies to recognize completely different molecules. In 2016, a new class of antibodies was identified. Unlike previously identified antibodies, these molecules had an entire human protein, called LAIR1, inserted into one of their CDR loops. Members of this group of antibodies bind to a molecule, known as a RIFIN, that is found on the surface of human red blood cells that are infected with the parasite that causes malaria. How do LAIR1-containing antibodies bind to their RIFIN targets? Hsieh and Higgins investigated this question by using a technique called X-ray crystallography to determine the structure of the antibody. This revealed that instead of binding directly to an antigen, all of the six CDR loops in the LAIR1-containing antibody bind to the LAIR1 insert. By doing so, LAIR1 is oriented in a manner that enables it to bind to the RIFIN molecule from the parasite. This is the first known example of an antibody that recruits another protein to bind to an antigen rather than binding directly to the pathogen itself. A future challenge will be to see if other antibodies exist that use this mechanism and whether it can be employed to design new therapeutic antibodies. DOI:http://dx.doi.org/10.7554/eLife.27311.002
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Affiliation(s)
- Fu-Lien Hsieh
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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115
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Pancera M, Changela A, Kwong PD. How HIV-1 entry mechanism and broadly neutralizing antibodies guide structure-based vaccine design. Curr Opin HIV AIDS 2017; 12:229-240. [PMID: 28422787 PMCID: PMC5557343 DOI: 10.1097/coh.0000000000000360] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW An HIV-1 vaccine that elicits broadly neutralizing antibodies (bNAbs) remains to be developed. Here, we review how knowledge of bNAbs and HIV-1 entry mechanism is guiding the structure-based design of vaccine immunogens and immunization regimens. RECENT FINDINGS Isolation of bNAbs from HIV-1-infected donors has led to an unprecedented understanding of the sites of vulnerability that these antibodies target on the HIV-1 envelope (Env) as well as of the immunological pathways that these antibody lineages follow to develop broad and potent neutralization. Sites of vulnerability, however, reside in the context of diverse Env conformations required for HIV-1 entry, including a prefusion-closed state, a single-CD4-bound intermediate, a three-CD4-bound intermediate, a prehairpin intermediate and postfusion states, and it is not always clear which structural state optimally presents a particular site of vulnerability in the vaccine context. Furthermore, detailed knowledge of immunological pathways has led to debate among vaccine developers as to how much of the natural antibody-developmental pathway immunogens should mimic, ranging from only the recognized epitope to multiple antigens from the antibody-virus coevolution process. SUMMARY A plethora of information on bNAbs is guiding HIV-1-vaccine development. We highlight consideration of the appropriate structural context from the HIV-1-entry mechanism and extraordinary progress with replicating template B-cell ontogenies.
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Affiliation(s)
- Marie Pancera
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Anita Changela
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Peter D. Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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116
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Rathore U, Saha P, Kesavardhana S, Kumar AA, Datta R, Devanarayanan S, Das R, Mascola JR, Varadarajan R. Glycosylation of the core of the HIV-1 envelope subunit protein gp120 is not required for native trimer formation or viral infectivity. J Biol Chem 2017; 292:10197-10219. [PMID: 28446609 DOI: 10.1074/jbc.m117.788919] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 04/26/2017] [Indexed: 01/05/2023] Open
Abstract
The gp120 subunit of the HIV-1 envelope (Env) protein is heavily glycosylated at ∼25 glycosylation sites, of which ∼7-8 are located in the V1/V2 and V3 variable loops and the others in the remaining core gp120 region. Glycans partially shield Env from recognition by the host immune system and also are believed to be indispensable for proper folding of gp120 and for viral infectivity. Previous attempts to alter glycosylation sites in Env typically involved mutating the glycosylated asparagine residues to structurally similar glutamines or alanines. Here, we confirmed that such mutations at multiple glycosylation sites greatly diminish viral infectivity and result in significantly reduced binding to both neutralizing and non-neutralizing antibodies. Therefore, using an alternative approach, we combined evolutionary information with structure-guided design and yeast surface display to produce properly cleaved HIV-1 Env variants that lack all 15 core gp120 glycans, yet retain conformational integrity and multiple-cycle viral infectivity and bind to several broadly neutralizing antibodies (bNAbs), including trimer-specific antibodies and a germline-reverted version of the bNAb VRC01. Our observations demonstrate that core gp120 glycans are not essential for folding, and hence their likely primary role is enabling immune evasion. We also show that our glycan removal approach is not strain restricted. Glycan-deficient Env derivatives can be used as priming immunogens because they should engage and activate a more divergent set of germlines than fully glycosylated Env. In conclusion, these results clarify the role of core gp120 glycosylation and illustrate a general method for designing glycan-free folded protein derivatives.
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Affiliation(s)
- Ujjwal Rathore
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India
| | - Piyali Saha
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India
| | - Sannula Kesavardhana
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India
| | - Aditya Arun Kumar
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India
| | - Rohini Datta
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India
| | | | - Raksha Das
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India
| | - John R Mascola
- the Vaccine Research Center, NIAID, National Institutes of Health, Bethesda, Maryland 20814, and
| | - Raghavan Varadarajan
- From the Molecular Biophysics Unit, Indian Institute of Science, 560012 Bangalore, India, .,the Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, 560064 Bangalore, India
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117
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Behrens AJ, Crispin M. Structural principles controlling HIV envelope glycosylation. Curr Opin Struct Biol 2017; 44:125-133. [PMID: 28363124 DOI: 10.1016/j.sbi.2017.03.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/09/2017] [Accepted: 03/14/2017] [Indexed: 12/21/2022]
Abstract
The heavily glycosylated, trimeric HIV-1 envelope (Env) protein is the sole viral protein exposed on the HIV-1 virion surface and is thus a main focus of antibody-mediated vaccine development. Dense glycosylation at the outer domain of Env constrains normal enzymatic processing, stalling the glycans at immature oligomannose-type structures. Furthermore, native trimerization imposes additional steric constraints, which generate an extensive 'trimer-induced mannose patch'. Importantly, the immature glycans present a highly conserved feature of the virus that is targeted by broadly neutralizing antibodies. Quantitative mass spectrometry of glycopeptides together with structures of the trimeric viral-spike define the steric principles controlling processing and provide a detailed map of the glycan shield.
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Affiliation(s)
- Anna-Janina Behrens
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
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118
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Global site-specific N-glycosylation analysis of HIV envelope glycoprotein. Nat Commun 2017; 8:14954. [PMID: 28348411 PMCID: PMC5379070 DOI: 10.1038/ncomms14954] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/15/2017] [Indexed: 02/07/2023] Open
Abstract
HIV-1 envelope glycoprotein (Env) is the sole target for broadly neutralizing antibodies (bnAbs) and the focus for design of an antibody-based HIV vaccine. The Env trimer is covered by ∼90N-linked glycans, which shield the underlying protein from immune surveillance. bNAbs to HIV develop during infection, with many showing dependence on glycans for binding to Env. The ability to routinely assess the glycan type at each glycosylation site may facilitate design of improved vaccine candidates. Here we present a general mass spectrometry-based proteomics strategy that uses specific endoglycosidases to introduce mass signatures that distinguish peptide glycosites that are unoccupied or occupied by high-mannose/hybrid or complex-type glycans. The method yields >95% sequence coverage for Env, provides semi-quantitative analysis of the glycosylation status at each glycosite. We find that most glycosites in recombinant Env trimers are fully occupied by glycans, varying in the proportion of high-mannose/hybrid and complex-type glycans. The analysis of site-specific glycosylation of HIV Envelope glycoprotein (Env) is challenging as it contains 25–30 glycosylation sites with multiple glycan forms at each site. Here the authors present a generally applicable mass spectrometry-based method for site-specific analysis of protein glycosylation that they apply to the analysis of the HIV-1 Env.
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119
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Behrens AJ, Seabright GE, Crispin M. Targeting Glycans of HIV Envelope Glycoproteins for Vaccine Design. CHEMICAL BIOLOGY OF GLYCOPROTEINS 2017. [DOI: 10.1039/9781782623823-00300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The surface of the envelope spike of the human immunodeficiency virus (HIV) is covered with a dense array of glycans, which is sufficient to impede the host antibody response while maintaining a window for receptor recognition. The glycan density significantly exceeds that typically observed on self glycoproteins and is sufficiently high to disrupt the maturation process of glycans, from oligomannose- to complex-type glycosylation, that normally occurs during glycoprotein transit through the secretory system. It is notable that this generates a degree of homogeneity not seen in the highly mutated protein moiety. The conserved, close glycan packing and divergences from default glycan processing give a window for immune recognition. Encouragingly, in a subset of individuals, broadly neutralizing antibodies (bNAbs) have been isolated that recognize these features and are protective in passive-transfer models. Here, we review the recent advances in our understanding of the glycan shield of HIV and outline the strategies that are being pursued to elicit glycan-binding bNAbs by vaccination.
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Affiliation(s)
- Anna-Janina Behrens
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford South Parks Road Oxford OX1 3QU UK
| | - Gemma E. Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford South Parks Road Oxford OX1 3QU UK
| | - Max Crispin
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford South Parks Road Oxford OX1 3QU UK
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120
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Struwe WB, Stuckmann A, Behrens AJ, Pagel K, Crispin M. Global N-Glycan Site Occupancy of HIV-1 gp120 by Metabolic Engineering and High-Resolution Intact Mass Spectrometry. ACS Chem Biol 2017; 12:357-361. [PMID: 27984693 DOI: 10.1021/acschembio.6b00854] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A vital step in HIV vaccine development strategies has been the observation that some infected individuals generate broadly neutralizing antibodies that target the glycans on the surface of HIV-1 gp120. These antibodies target glycan epitopes on viral envelope spikes, and yet the positions and degree of occupancy of glycosylation sites is diverse. Therefore, there is a need to understand glycosylation occupancy on recombinant immunogens. The sheer number of potential glycosylation sites and degree of chemical heterogeneity impedes assessing the global sequon occupancy of gp120 glycoforms. Here, we trap the glycan processing of recombinant gp120 to generate homogeneous glycoforms, facilitating occupancy assessment by intact mass spectrometry. We show that gp120 monomers of the BG505 strain contain either fully occupied sequons or missing the equivalent of one and sometimes two glycans across the molecule. This biosynthetic engineering approach enables the analysis of therapeutically important glycoproteins otherwise recalcitrant to analysis by native mass spectrometry.
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Affiliation(s)
- Weston B. Struwe
- Oxford
Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Alexandra Stuckmann
- Free University Berlin, Department of Chemistry
and Biochemistry, Takustrasse
3, 14195 Berlin, Germany
| | - Anna-Janina Behrens
- Oxford
Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Kevin Pagel
- Free University Berlin, Department of Chemistry
and Biochemistry, Takustrasse
3, 14195 Berlin, Germany
| | - Max Crispin
- Oxford
Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
- Department
of Immunology and Microbial Science, The Scripps Research Institute, La
Jolla, California 92037, United States
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121
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Nguyen HT, Madani N, Ding H, Elder E, Princiotto A, Gu C, Darby P, Alin J, Herschhorn A, Kappes JC, Mao Y, Sodroski JG. Evaluation of the contribution of the transmembrane region to the ectodomain conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein. Virol J 2017; 14:33. [PMID: 28209172 PMCID: PMC5314615 DOI: 10.1186/s12985-017-0704-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/10/2017] [Indexed: 12/26/2022] Open
Abstract
Background The human immunodeficiency virus (HIV-1) envelope glycoprotein (Env), a Type 1 transmembrane protein, assembles into a trimeric spike complex that mediates virus entry into host cells. The high potential energy of the metastable, unliganded Env trimer is maintained by multiple non-covalent contacts among the gp120 exterior and gp41 transmembrane Env subunits. Structural studies suggest that the gp41 transmembrane region forms a left-handed coiled coil that contributes to the Env trimer interprotomer contacts. Here we evaluate the contribution of the gp41 transmembrane region to the folding and stability of Env trimers. Methods Multiple polar/charged amino acid residues, which hypothetically disrupt the stop-transfer signal, were introduced in the proposed lipid-interactive face of the transmembrane coiled coil, allowing release of soluble cleavage-negative Envs containing the modified transmembrane region (TMmod). We also examined effects of cleavage, the cytoplasmic tail and a C-terminal fibritin trimerization (FT) motif on oligomerization, antigenicity and functionality of soluble and membrane-bound Envs. Results The introduction of polar/charged amino acids into the transmembrane region resulted in the secretion of soluble Envs from the cell. However, these TMmod Envs primarily formed dimers. By contrast, control cleavage-negative sgp140 Envs lacking the transmembrane region formed soluble trimers, dimers and monomers. TMmod and sgp140 trimers were stabilized by the addition of a C-terminal FT sequence, but still exhibited carbohydrate and antigenic signatures of a flexible ectodomain structure. On the other hand, detergent-solubilized cleaved and uncleaved Envs isolated from the membranes of expressing cells exhibited "tighter” ectodomain structures, based on carbohydrate modifications. These trimers were found to be unstable in detergent solutions, but could be stabilized by the addition of a C-terminal FT moiety. The C-terminal FT domain decreased Env cleavage and syncytium-forming ability by approximately three-fold; alteration of the FT trimerization interface restored Env cleavage and syncytium formation to near-wild-type levels. Conclusion The modified transmembrane region was not conducive to trimerization of soluble Envs. However, for HIV-1 Env ectodomains that are minimally modified, membrane-anchored Envs exhibit the most native structures and can be stabilized by appropriately positioned FT domains.
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Affiliation(s)
- Hanh T Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Navid Madani
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Emerald Elder
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Amy Princiotto
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Christopher Gu
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Patrice Darby
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - James Alin
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Alon Herschhorn
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL, 35233, USA
| | - Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA
| | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, 450 Brookline Avenue, CLS 1010, Boston, MA, 02215, USA. .,Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02215, USA.
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Aiyegbo MS, Shmelkov E, Dominguez L, Goger M, Battacharya S, deCamp AC, Gilbert PB, Berman PW, Cardozo T. Peptide Targeted by Human Antibodies Associated with HIV Vaccine-Associated Protection Assumes a Dynamic α-Helical Structure. PLoS One 2017; 12:e0170530. [PMID: 28107435 PMCID: PMC5249078 DOI: 10.1371/journal.pone.0170530] [Citation(s) in RCA: 10] [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: 11/14/2016] [Accepted: 01/05/2017] [Indexed: 02/02/2023] Open
Abstract
The only evidence of vaccine-induced protection from HIV acquisition in humans was obtained in the RV144 HIV vaccine clinical trial. One immune correlate of risk in RV144 was observed to be higher titers of vaccine-induced antibodies (Abs) reacting with a 23-mer non-glycosylated peptide with the same amino acid sequence as a segment in the second variable (V2) loop of the MN strain of HIV. We used NMR to analyze the dynamic 3D structure of this peptide. Distance restraints between spatially proximate inter-residue protons were calculated from NOE cross peak intensities and used to constrain a thorough search of all possible conformations of the peptide. α–helical folding was strongly preferred by part of the peptide. A high-throughput structure prediction of this segment in all circulating HIV strains demonstrated that α–helical conformations are preferred by this segment almost universally across all subtypes. Notably, α–helical conformations of this segment of the V2 loop cluster cross-subtype-conserved amino acids on one face of the helix and the variable amino acid positions on the other in a semblance of an amphipathic α–helix. Accordingly, some Abs that protected against HIV in RV144 may have targeted a specific, conserved α–helical peptide epitope in the V2 loop of HIV’s surface envelope glycoprotein.
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Affiliation(s)
- Mohammed S. Aiyegbo
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Evgeny Shmelkov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Lorenzo Dominguez
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Michael Goger
- The New York Structural Biology Center, New York, New York, United States of America
| | - Shibani Battacharya
- The New York Structural Biology Center, New York, New York, United States of America
| | - Allan C. deCamp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Peter B. Gilbert
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Phillip W. Berman
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Timothy Cardozo
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
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123
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Jaworski JP, Vendrell A, Chiavenna SM. Neutralizing Monoclonal Antibodies to Fight HIV-1: On the Threshold of Success. Front Immunol 2017; 7:661. [PMID: 28123384 PMCID: PMC5225137 DOI: 10.3389/fimmu.2016.00661] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 12/16/2016] [Indexed: 12/21/2022] Open
Abstract
Anti-human immunodeficiency virus type-1 (anti-HIV-1) neutralizing monoclonal antibodies are broadening the spectrum of pre- and post-exposure treatment against HIV-1. A better understanding of how these antibodies develop and interact with particular regions of the viral envelope protein is guiding a more rational structure-based immunogen design. The aim of this article is to review the most recent advances in the field, from the development of these particular antibodies during natural HIV-1 infection, to their role preventing infection, boosting endogenous immune responses and clearing both free viral particles and persistently infected cells.
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Affiliation(s)
- Juan Pablo Jaworski
- National Scientific and Technical Research Council, Buenos Aires, Argentina; Institute of Virology, National Institute of Agricultural Technology, Castelar, Buenos Aires, Argentina
| | - Alejandrina Vendrell
- Pharmacological and Botanical Study Center, School of Medicine, University of Buenos Aires , Buenos Aires , Argentina
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124
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Molecular Architecture of the Cleavage-Dependent Mannose Patch on a Soluble HIV-1 Envelope Glycoprotein Trimer. J Virol 2017; 91:JVI.01894-16. [PMID: 27807235 DOI: 10.1128/jvi.01894-16] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 10/25/2016] [Indexed: 01/04/2023] Open
Abstract
The formation of a correctly folded and natively glycosylated HIV-1 viral spike is dependent on protease cleavage of the gp160 precursor protein in the Golgi apparatus. Cleavage induces a compact structure which not only renders the spike capable of fusion but also limits further maturation of its extensive glycosylation. The redirection of the glycosylation pathway to preserve underprocessed oligomannose-type glycans is an important feature in immunogen design, as glycans contribute to or influence the epitopes of numerous broadly neutralizing antibodies. Here we present a quantitative site-specific analysis of a recombinant, trimeric mimic of the native HIV-1 viral spike (BG505 SOSIP.664) compared to the corresponding uncleaved pseudotrimer and the matched gp120 monomer. We present a detailed molecular map of a trimer-associated glycan remodeling that forms a localized subdomain of the native mannose patch. The formation of native trimers is a critical design feature in shaping the glycan epitopes presented on recombinant vaccine candidates. IMPORTANCE The envelope spike of human immunodeficiency virus type 1 (HIV-1) is a target for antibody-based neutralization. For some patients infected with HIV-1, highly potent antibodies have been isolated that can neutralize a wide range of circulating viruses. It is a goal of HIV-1 vaccine research to elicit these antibodies by immunization with recombinant mimics of the viral spike. These antibodies have evolved to recognize the dense array of glycans that coat the surface of the viral molecule. We show how the structure of these glycans is shaped by steric constraints imposed upon them by the native folding of the viral spike. This information is important in guiding the development of vaccine candidates.
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125
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Chan SK, Lim TS. Immune Human Antibody Libraries for Infectious Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1053:61-78. [PMID: 29549635 DOI: 10.1007/978-3-319-72077-7_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The incident of two children in Europe who died of diphtheria due to a shortage of anti-toxin drugs has highlighted the need for alternative anti-toxins. Historically, antiserum produced from immunised horses have been used to treat diphtheria. Despite the potential of antiserum, the economical and medial concerns associated with the use of animal antiserum has led to its slow market demise. Over the years, new and emerging infectious diseases have grown to be a major global health threat. The emergence of drug-resistant superbugs has also pushed the boundaries of available therapeutics to deal with new infectious diseases. Antibodies have emerged as a possible alternative to combat the continuous onslaught of various infectious agents. The isolation of antibodies against pathogens of infectious diseases isolated from immune libraries utilising phage display has yielded promising results in terms of affinities and neutralizing activities. This chapter focuses on the concept of immune antibody libraries and highlights the application of immune antibody libraries to generate antibodies for various infectious diseases.
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Affiliation(s)
- Soo Khim Chan
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang, Malaysia.
- Analytical Biochemistry Research Centre, Universiti Sains Malaysia, Minden, 11800, Penang, Malaysia.
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126
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Verkoczy L. Humanized Immunoglobulin Mice: Models for HIV Vaccine Testing and Studying the Broadly Neutralizing Antibody Problem. Adv Immunol 2017; 134:235-352. [PMID: 28413022 PMCID: PMC5914178 DOI: 10.1016/bs.ai.2017.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A vaccine that can effectively prevent HIV-1 transmission remains paramount to ending the HIV pandemic, but to do so, will likely need to induce broadly neutralizing antibody (bnAb) responses. A major technical hurdle toward achieving this goal has been a shortage of animal models with the ability to systematically pinpoint roadblocks to bnAb induction and to rank vaccine strategies based on their ability to stimulate bnAb development. Over the past 6 years, immunoglobulin (Ig) knock-in (KI) technology has been leveraged to express bnAbs in mice, an approach that has enabled elucidation of various B-cell tolerance mechanisms limiting bnAb production and evaluation of strategies to circumvent such processes. From these studies, in conjunction with the wealth of information recently obtained regarding the evolutionary pathways and paratopes/epitopes of multiple bnAbs, it has become clear that the very features of bnAbs desired for their function will be problematic to elicit by traditional vaccine paradigms, necessitating more iterative testing of new vaccine concepts. To meet this need, novel bnAb KI models have now been engineered to express either inferred prerearranged V(D)J exons (or unrearranged germline V, D, or J segments that can be assembled into functional rearranged V(D)J exons) encoding predecessors of mature bnAbs. One encouraging approach that has materialized from studies using such newer models is sequential administration of immunogens designed to bind progressively more mature bnAb predecessors. In this review, insights into the regulation and induction of bnAbs based on the use of KI models will be discussed, as will new Ig KI approaches for higher-throughput production and/or altering expression of bnAbs in vivo, so as to further enable vaccine-guided bnAb induction studies.
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Affiliation(s)
- Laurent Verkoczy
- Duke University Human Vaccine Institute, Duke University School of Medicine, Durham, NC, United States.
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127
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Wiehe K, Nicely NI, Lockwood B, Kuraoka M, Anasti K, Arora S, Bowman CM, Stolarchuk C, Parks R, Lloyd KE, Xia SM, Duffy R, Shen X, Kyratsous CA, Macdonald LE, Murphy AJ, Scearce RM, Moody MA, Alam SM, Verkoczy L, Tomaras GD, Kelsoe G, Haynes BF. Immunodominance of Antibody Recognition of the HIV Envelope V2 Region in Ig-Humanized Mice. THE JOURNAL OF IMMUNOLOGY 2016; 198:1047-1055. [PMID: 28011932 DOI: 10.4049/jimmunol.1601640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/18/2016] [Indexed: 12/13/2022]
Abstract
In the RV144 gp120 HIV vaccine trial, decreased transmission risk was correlated with Abs that reacted with a linear epitope at a lysine residue at position 169 (K169) in the HIV-1 envelope (Env) V2 region. The K169 V2 response was restricted to Abs bearing Vλ rearrangements that expressed aspartic acid/glutamic acid in CDR L2. The AE.A244 gp120 in AIDSVAX B/E also bound to the unmutated ancestor of a V2-glycan broadly neutralizing Ab, but this Ab type was not induced in the RV144 trial. In this study, we sought to determine whether immunodominance of the V2 linear epitope could be overcome in the absence of human Vλ rearrangements. We immunized IgH- and Igκ-humanized mice with the AE.A244 gp120 Env. In these mice, the V2 Ab response was focused on a linear epitope that did not include K169. V2 Abs were isolated that used the same human VH gene segment as an RV144 V2 Ab but paired with a mouse λ L chain. Structural characterization of one of these V2 Abs revealed how the linear V2 epitope could be engaged, despite the lack of aspartic acid/glutamic acid encoded in the mouse repertoire. Thus, despite the absence of the human Vλ locus in these humanized mice, the dominance of Vλ pairing with human VH for HIV-1 Env V2 recognition resulted in human VH pairing with mouse λ L chains instead of allowing otherwise subdominant V2-glycan broadly neutralizing Abs to develop.
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Affiliation(s)
- Kevin Wiehe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710; .,Department of Medicine, Duke University School of Medicine, Durham, NC 27710
| | - Nathan I Nicely
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Bradley Lockwood
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | | | - Kara Anasti
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Sabrina Arora
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Cindy M Bowman
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Christina Stolarchuk
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Krissey E Lloyd
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Shi-Mao Xia
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Ryan Duffy
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - Xiaoying Shen
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | | | | | | | - Richard M Scearce
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710
| | - M Anthony Moody
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710.,Department of Immunology, Duke University, Durham, NC 27710.,Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710.,Department of Pathology, Duke University School of Medicine, Durham, NC 27710; and
| | - Laurent Verkoczy
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710.,Department of Pathology, Duke University School of Medicine, Durham, NC 27710; and
| | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710.,Department of Surgery, Duke University School of Medicine, Durham, NC 27710
| | - Garnett Kelsoe
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710.,Department of Immunology, Duke University, Durham, NC 27710
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710.,Department of Medicine, Duke University School of Medicine, Durham, NC 27710.,Department of Immunology, Duke University, Durham, NC 27710
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128
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Broadly Neutralizing Antibodies Display Potential for Prevention of HIV-1 Infection of Mucosal Tissue Superior to That of Nonneutralizing Antibodies. J Virol 2016; 91:JVI.01762-16. [PMID: 27795431 PMCID: PMC5165208 DOI: 10.1128/jvi.01762-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/04/2016] [Indexed: 12/02/2022] Open
Abstract
Definition of the key parameters mediating effective antibody blocking of HIV-1 acquisition within mucosal tissue may prove critical to effective vaccine development and the prophylactic use of monoclonal antibodies. Although direct antibody-mediated neutralization is highly effective against cell-free virus, antibodies targeting different sites of envelope vulnerability may display differential activity against mucosal infection. Nonneutralizing antibodies (nnAbs) may also impact mucosal transmission events through Fc-gamma receptor (FcγR)-mediated inhibition. In this study, a panel of broadly neutralizing antibodies (bnAbs) and nnAbs, including those associated with protection in the RV144 vaccine trial, were screened for the ability to block HIV-1 acquisition and replication across a range of cellular and mucosal tissue models. Neutralization potency, as determined by the TZM-bl infection assay, did not fully predict activity in mucosal tissue. CD4-binding site (CD4bs)-specific bnAbs, in particular VRC01, were consistent in blocking HIV-1 infection across all cellular and tissue models. Membrane-proximal external region (MPER) (2F5) and outer domain glycan (2G12) bnAbs were also efficient in preventing infection of mucosal tissues, while the protective efficacy of bnAbs targeting V1-V2 glycans (PG9 and PG16) was more variable. In contrast, nnAbs alone and in combinations, while active in a range of cellular assays, were poorly protective against HIV-1 infection of mucosal tissues. These data suggest that tissue resident effector cell numbers and low FcγR expression may limit the potential of nnAbs to prevent establishment of the initial foci of infection. The solid protection provided by specific bnAbs clearly demonstrates their superior potential over that of nonneutralizing antibodies for preventing HIV-1 infection at the mucosal portals of infection.
IMPORTANCE Key parameters mediating effective antibody blocking of HIV-1 acquisition within mucosal tissue have not been defined. While bnAbs are highly effective against cell-free virus, they are not induced by current vaccine candidates. However, nnAbs, readily induced by vaccines, can trigger antibody-dependent cellular effector functions, through engagement of their Fc-gamma receptors. Fc-mediated antiviral activity has been implicated as a secondary correlate of decreased HIV-1 risk in the RV144 vaccine efficacy trial, suggesting that protection might be mediated in the absence of classical neutralization. To aid vaccine design and selection of antibodies for use in passive protection strategies, we assessed a range of bnAbs and nnAbs for their potential to block ex vivo challenge of mucosal tissues. Our data clearly indicate the superior efficacy of neutralizing antibodies in preventing mucosal acquisition of infection. These results underscore the importance of maintaining the central focus of HIV-1 vaccine research on the induction of potently neutralizing antibodies.
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129
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Rationally Designed Immunogens Targeting HIV-1 gp120 V1V2 Induce Distinct Conformation-Specific Antibody Responses in Rabbits. J Virol 2016; 90:11007-11019. [PMID: 27707920 DOI: 10.1128/jvi.01409-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/23/2016] [Indexed: 11/20/2022] Open
Abstract
The V1V2 region of HIV-1 gp120 harbors a major vulnerable site targeted by a group of broadly neutralizing monoclonal antibodies (MAbs) such as PG9 through strand-strand recognition. However, this epitope region is structurally polymorphic as it can also form a helical conformation recognized by RV144 vaccine-induced MAb CH58. This structural polymorphism is a potential mechanism for masking the V1V2 vulnerable site. Designing immunogens that can induce conformation-specific antibody (Ab) responses may lead to vaccines targeting this vulnerable site. We designed a panel of immunogens engrafting the V1V2 domain into trimeric and pentameric scaffolds in structurally constrained conformations. We also fused V1V2 to an Fc fragment to mimic the unconstrained V1V2 conformation. We tested these V1V2-scaffold proteins for immunogenicity in rabbits and assessed the responses by enzyme-linked immunosorbent assay (ELISA) and competition assays. Our V1V2 immunogens induced distinct conformation-specific Ab responses. Abs induced by structurally unconstrained immunogens reacted preferentially with unconstrained V1V2 antigens, suggesting recognition of the helical configuration, while Abs induced by the structurally constrained immunogens reacted preferentially with constrained V1V2 antigens, suggesting recognition of the β-strand conformation. The Ab responses induced by the structurally constrained immunogens were more broadly reactive and had higher titers than those induced by the structurally unconstrained immunogens. Our results demonstrate that immunogens presenting the different structural conformations of the gp120 V1V2 vulnerable site can be designed and that these immunogens induce distinct Ab responses with epitope conformation specificity. Therefore, these structurally constrained V1V2 immunogens are vaccine prototypes targeting the V1V2 domain of the HIV-1 envelope. IMPORTANCE The correlates analysis of the RV144 HIV-1 vaccine trial suggested that the presence of antibodies to the V1V2 region of HIV-1 gp120 was responsible for the modest protection observed in the trial. In addition, V1V2 harbors one of the key vulnerable sites of HIV-1 Env recognized by a family of broadly neutralizing MAbs such as PG9. Thus, V1V2 is a key target for vaccine development. However, this vulnerable site is structurally polymorphic, and designing immunogens that present different conformations is crucial for targeting this site. We show here that such immunogens can be designed and that they induced conformation-specific antibody responses in rabbits. Our immunogens are therefore prototypes of vaccine candidates targeting the V1V2 region of HIV-1 Env.
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130
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Lusvarghi S, Lohith K, Morin-Leisk J, Ghirlando R, Hinshaw JE, Bewley CA. Binding Site Geometry and Subdomain Valency Control Effects of Neutralizing Lectins on HIV-1 Viral Particles. ACS Infect Dis 2016; 2:882-891. [PMID: 27669574 DOI: 10.1021/acsinfecdis.6b00139] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Carbohydrate binding proteins such as griffithsin, cyanovirin-N, and BanLec are potent HIV entry inhibitors and promising microbicides. Each binds to high-mannose glycans on the surface envelope glycoprotein gp120, yet the mechanisms by which they engage viral spikes and exhibit inhibition constants ranging from nanomolar to picomolar are not understood. To determine the structural and mechanistic basis for recognition and potency, we selected a panel of lectins possessing different valencies per subunit, oligomeric states, and relative orientations of carbohydrate binding sites to systematically probe their contributions to inhibiting viral entry. Cryo-electron micrographs and immuno gold staining of lectin-treated viral particles revealed two distinct effects-namely, viral aggregation or clustering of the HIV-1 envelope on the viral membrane-that were dictated by carbohydrate binding site geometry and valency. "Sandwich" surface plasmon resonance experiments revealed that a second binding event occurs only for those lectins that could aggregate viral particles. Furthermore, picomolar Kd values were observed for the second binding event, providing a mechanism by which picomolar IC50 values are achieved. We suggest that these binding and aggregation phenomena translate to neutralization potency.
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Affiliation(s)
- Sabrina Lusvarghi
- Laboratory of Bioorganic
Chemistry, ‡Laboratory of Cell and Molecular Biology and #Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Center Drive, Bethesda, Maryland 20892, United States
| | - Katheryn Lohith
- Laboratory of Bioorganic
Chemistry, ‡Laboratory of Cell and Molecular Biology and #Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Center Drive, Bethesda, Maryland 20892, United States
| | - Jeanne Morin-Leisk
- Laboratory of Bioorganic
Chemistry, ‡Laboratory of Cell and Molecular Biology and #Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Center Drive, Bethesda, Maryland 20892, United States
| | - Rodolfo Ghirlando
- Laboratory of Bioorganic
Chemistry, ‡Laboratory of Cell and Molecular Biology and #Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Center Drive, Bethesda, Maryland 20892, United States
| | - Jenny E. Hinshaw
- Laboratory of Bioorganic
Chemistry, ‡Laboratory of Cell and Molecular Biology and #Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Center Drive, Bethesda, Maryland 20892, United States
| | - Carole A. Bewley
- Laboratory of Bioorganic
Chemistry, ‡Laboratory of Cell and Molecular Biology and #Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Center Drive, Bethesda, Maryland 20892, United States
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131
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Reconstituted B cell receptor signaling reveals carbohydrate-dependent mode of activation. Sci Rep 2016; 6:36298. [PMID: 27796362 PMCID: PMC5087089 DOI: 10.1038/srep36298] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/13/2016] [Indexed: 11/08/2022] Open
Abstract
Activation of immune cells (but not B cells) with lectins is widely known. We used the structurally defined interaction between influenza hemagglutinin (HA) and its cell surface receptor sialic acid (SA) to identify a B cell receptor (BCR) activation modality that proceeded through non-cognate interactions with antigen. Using a new approach to reconstitute antigen-receptor interactions in a human reporter B cell line, we found that sequence-defined BCRs from the human germline repertoire could be triggered by both complementarity to influenza HA and a separate mode of signaling that relied on multivalent ligation of BCR sialyl-oligosaccharide. The latter suggested a new mechanism for priming naïve B cell responses and manifested as the induction of SA-dependent pan-activation by peripheral blood B cells. BCR crosslinking in the absence of complementarity is a superantigen effect induced by some microbial products to subvert production of antigen-specific immune responses. B cell superantigen activity through affinity for BCR carbohydrate is discussed.
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132
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Deconstructing the Antiviral Neutralizing-Antibody Response: Implications for Vaccine Development and Immunity. Microbiol Mol Biol Rev 2016; 80:989-1010. [PMID: 27784796 DOI: 10.1128/mmbr.00024-15] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The antibody response plays a key role in protection against viral infections. While antiviral antibodies may reduce the viral burden via several mechanisms, the ability to directly inhibit (neutralize) infection of cells has been extensively studied. Eliciting a neutralizing-antibody response is a goal of many vaccine development programs and commonly correlates with protection from disease. Considerable insights into the mechanisms of neutralization have been gained from studies of monoclonal antibodies, yet the individual contributions and dynamics of the repertoire of circulating antibody specificities elicited by infection and vaccination are poorly understood on the functional and molecular levels. Neutralizing antibodies with the most protective functionalities may be a rare component of a polyclonal, pathogen-specific antibody response, further complicating efforts to identify the elements of a protective immune response. This review discusses advances in deconstructing polyclonal antibody responses to flavivirus infection or vaccination. Our discussions draw comparisons to HIV-1, a virus with a distinct structure and replication cycle for which the antibody response has been extensively investigated. Progress toward deconstructing and understanding the components of polyclonal antibody responses identifies new targets and challenges for vaccination strategies.
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133
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Tian J, López CA, Derdeyn CA, Jones MS, Pinter A, Korber B, Gnanakaran S. Effect of Glycosylation on an Immunodominant Region in the V1V2 Variable Domain of the HIV-1 Envelope gp120 Protein. PLoS Comput Biol 2016; 12:e1005094. [PMID: 27716795 PMCID: PMC5055340 DOI: 10.1371/journal.pcbi.1005094] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 08/01/2016] [Indexed: 12/14/2022] Open
Abstract
Heavy glycosylation of the envelope (Env) surface subunit, gp120, is a key adaptation of HIV-1; however, the precise effects of glycosylation on the folding, conformation and dynamics of this protein are poorly understood. Here we explore the patterns of HIV-1 Env gp120 glycosylation, and particularly the enrichment in glycosylation sites proximal to the disulfide linkages at the base of the surface-exposed variable domains. To dissect the influence of glycans on the conformation these regions, we focused on an antigenic peptide fragment from a disulfide bridge-bounded region spanning the V1 and V2 hyper-variable domains of HIV-1 gp120. We used replica exchange molecular dynamics (MD) simulations to investigate how glycosylation influences its conformation and stability. Simulations were performed with and without N-linked glycosylation at two sites that are highly conserved across HIV-1 isolates (N156 and N160); both are contacts for recognition by V1V2-targeted broadly neutralizing antibodies against HIV-1. Glycosylation stabilized the pre-existing conformations of this peptide construct, reduced its propensity to adopt other secondary structures, and provided resistance against thermal unfolding. Simulations performed in the context of the Env trimer also indicated that glycosylation reduces flexibility of the V1V2 region, and provided insight into glycan-glycan interactions in this region. These stabilizing effects were influenced by a combination of factors, including the presence of a disulfide bond between the Cysteines at 131 and 157, which increased the formation of beta-strands. Together, these results provide a mechanism for conservation of disulfide linkage proximal glycosylation adjacent to the variable domains of gp120 and begin to explain how this could be exploited to enhance the immunogenicity of those regions. These studies suggest that glycopeptide immunogens can be designed to stabilize the most relevant Env conformations to focus the immune response on key neutralizing epitopes. Heavy glycosylation of the envelope surface subunit, gp120, is a key adaptation of HIV-1, however, the precise effects of glycosylation on the folding, conformation and dynamics of this protein are poorly understood. The network of glycans on gp120 is of particular interest with regards to vaccine design, because the glycans both serve as targets for many classes of broadly neutralizing antibodies, and contribute to patterns of immune evasion and escape during HIV-1 infection. In this manuscript, we report on how glycosylation influences an immunogenic but disordered region of gp120. Glycosylation stabilizes the pre-existing conformation, and reduces its propensity to form other secondary structures. It also stabilizes preformed conformation against thermal unfolding. These complementary effects originate from a combination of multiple factors, including the observation that having a glycosylation site adjacent to the disulfide bond further promotes the formation of beta-strand structure in this peptide.
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Affiliation(s)
- Jianhui Tian
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Center for Biomolecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Cesar A. López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Cynthia A. Derdeyn
- Department of Pathology and Laboratory Medicine and Emory Vaccine Center, Emory University, Atlanta, Georgia, United States of America
| | - Morris S. Jones
- University of California Berkeley, School of Public Health, Berkeley, California, United States of America
| | - Abraham Pinter
- New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Bette Korber
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - S. Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- * E-mail:
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134
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Changes in Structure and Antigenicity of HIV-1 Env Trimers Resulting from Removal of a Conserved CD4 Binding Site-Proximal Glycan. J Virol 2016; 90:9224-36. [PMID: 27489265 DOI: 10.1128/jvi.01116-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/27/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED The envelope glycoprotein (Env) is the major target for HIV-1 broadly neutralizing antibodies (bNAbs). One of the mechanisms that HIV has evolved to escape the host's immune response is to mask conserved epitopes on Env with dense glycosylation. Previous studies have shown that the removal of a particular conserved glycan at N197 increases the neutralization sensitivity of the virus to antibodies targeting the CD4 binding site (CD4bs), making it a site of significant interest from the perspective of vaccine design. At present, the structural consequences that result from the removal of the N197 glycan have not been characterized. Using native-like SOSIP trimers, we examine the effects on antigenicity and local structural dynamics resulting from the removal of this glycan. A large increase in the binding of CD4bs and V3-targeting antibodies is observed for the N197Q mutant in trimeric Env, while no changes are observed with monomeric gp120. While the overall structure and thermostability are not altered, a subtle increase in the flexibility of the variable loops at the trimeric interface of adjacent protomers is evident in the N197Q mutant by hydrogen-deuterium exchange mass spectrometry. Structural modeling of the glycan chains suggests that the spatial occupancy of the N197 glycan leads to steric clashes with CD4bs antibodies in the Env trimer but not monomeric gp120. Our results indicate that the removal of the N197 glycan enhances the exposure of relevant bNAb epitopes on Env with a minimal impact on the overall trimeric structure. These findings present a simple modification for enhancing trimeric Env immunogens in vaccines. IMPORTANCE The HIV-1 Env glycoprotein presents a dense patchwork of host cell-derived N-linked glycans. This so-called glycan shield is considered to be a major protective mechanism against immune recognition. While the positions of many N-linked glycans are isolate specific, some are highly conserved and are believed to play key functional roles. In this study, we examine the conserved, CD4 binding site-proximal N197 glycan and demonstrate that its removal both facilitates neutralizing antibody access to the CD4 binding site and modestly impacts the structural dynamics at the trimer crown without drastically altering global Env trimer stability. This indicates that surgical glycosylation site modification may be an effective way of sculpting epitope presentation in Env-based vaccines.
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135
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Gristick HB, von Boehmer L, West AP, Schamber M, Gazumyan A, Golijanin J, Seaman MS, Fätkenheuer G, Klein F, Nussenzweig MC, Bjorkman PJ. Natively glycosylated HIV-1 Env structure reveals new mode for antibody recognition of the CD4-binding site. Nat Struct Mol Biol 2016; 23:906-915. [PMID: 27617431 DOI: 10.1038/nsmb.3291] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/10/2016] [Indexed: 12/14/2022]
Abstract
HIV-1 vaccine design is informed by structural studies elucidating mechanisms by which broadly neutralizing antibodies (bNAbs) recognize and/or accommodate N-glycans on the trimeric envelope glycoprotein (Env). Variability in high-mannose and complex-type Env glycoforms leads to heterogeneity that usually precludes visualization of the native glycan shield. We present 3.5-Å- and 3.9-Å-resolution crystal structures of the HIV-1 Env trimer with fully processed and native glycosylation, revealing a glycan shield of high-mannose and complex-type N-glycans, which we used to define complete epitopes of two bNAbs. Env trimer was complexed with 10-1074 (against the V3-loop) and IOMA, a new CD4-binding site (CD4bs) antibody. Although IOMA derives from VH1-2*02, the germline gene of CD4bs-targeting VRC01-class bNAbs, its light chain lacks the short CDRL3 that defines VRC01-class bNAbs. Thus IOMA resembles 8ANC131-class/VH1-46-derived CD4bs bNAbs, which have normal-length CDRL3s. The existence of bNAbs that combine features of VRC01-class and 8ANC131-class antibodies has implications for immunization strategies targeting VRC01-like bNAbs.
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Affiliation(s)
- Harry B Gristick
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Lotta von Boehmer
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
| | - Anthony P West
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Michael Schamber
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Anna Gazumyan
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
| | - Jovana Golijanin
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA
| | - Michael S Seaman
- Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Gerd Fätkenheuer
- Department of Internal Medicine I, University Hospital of Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
| | - Florian Klein
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany.,Laboratory of Experimental Immunology, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Department of Internal Medicine I, Center of Integrated Oncology Cologne-Bonn, University Hospital Cologne, Cologne, Germany
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, New York, USA.,Howard Hughes Medical Institute, The Rockefeller University, New York, New York, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
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136
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Panico M, Bouché L, Binet D, O’Connor MJ, Rahman D, Pang PC, Canis K, North SJ, Desrosiers RC, Chertova E, Keele BF, Bess JW, Lifson JD, Haslam SM, Dell A, Morris HR. Mapping the complete glycoproteome of virion-derived HIV-1 gp120 provides insights into broadly neutralizing antibody binding. Sci Rep 2016; 6:32956. [PMID: 27604319 PMCID: PMC5015092 DOI: 10.1038/srep32956] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/17/2016] [Indexed: 12/31/2022] Open
Abstract
The surface envelope glycoprotein (SU) of Human immunodeficiency virus type 1 (HIV-1), gp120(SU) plays an essential role in virus binding to target CD4+ T-cells and is a major vaccine target. Gp120 has remarkably high levels of N-linked glycosylation and there is considerable evidence that this "glycan shield" can help protect the virus from antibody-mediated neutralization. In recent years, however, it has become clear that gp120 glycosylation can also be included in the targets of recognition by some of the most potent broadly neutralizing antibodies. Knowing the site-specific glycosylation of gp120 can facilitate the rational design of glycopeptide antigens for HIV vaccine development. While most prior studies have focused on glycan analysis of recombinant forms of gp120, here we report the first systematic glycosylation site analysis of gp120 derived from virions produced by infected T lymphoid cells and show that a single site is exclusively substituted with complex glycans. These results should help guide the design of vaccine immunogens.
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Affiliation(s)
- Maria Panico
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Laura Bouché
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Daniel Binet
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey, JE2 7LA, UK
| | - Michael-John O’Connor
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey, JE2 7LA, UK
| | - Dinah Rahman
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Poh-Choo Pang
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Kevin Canis
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Simon J. North
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | | | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Julian W. Bess
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Stuart M. Haslam
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Anne Dell
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Howard R. Morris
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey, JE2 7LA, UK
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137
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Somatic Hypermutation-Induced Changes in the Structure and Dynamics of HIV-1 Broadly Neutralizing Antibodies. Structure 2016; 24:1346-1357. [PMID: 27477385 PMCID: PMC5250619 DOI: 10.1016/j.str.2016.06.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/25/2016] [Accepted: 06/08/2016] [Indexed: 01/07/2023]
Abstract
Antibody somatic hypermutation (SHM) and affinity maturation enhance antigen recognition by modifying antibody paratope structure to improve its complementarity with the target epitope. SHM-induced changes in paratope dynamics may also contribute to antibody maturation, but direct evidence of this is limited. Here, we examine two classes of HIV-1 broadly neutralizing antibodies (bNAbs) for SHM-induced changes in structure and dynamics, and delineate the effects of these changes on interactions with the HIV-1 envelope glycoprotein (Env). In combination with new and existing structures of unmutated and affinity matured antibody Fab fragments, we used hydrogen/deuterium exchange with mass spectrometry to directly measure Fab structural dynamics. Changes in antibody structure and dynamics were positioned to improve complementarity with Env, with changes in dynamics primarily observed at the paratope peripheries. We conclude that SHM optimizes paratope complementarity to conserved HIV-1 epitopes and restricts the mobility of paratope-peripheral residues to minimize clashes with variable features on HIV-1 Env.
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138
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Hua CK, Ackerman ME. Engineering broadly neutralizing antibodies for HIV prevention and therapy. Adv Drug Deliv Rev 2016; 103:157-173. [PMID: 26827912 DOI: 10.1016/j.addr.2016.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 01/15/2023]
Abstract
A combination of advances spanning from isolation to delivery of potent HIV-specific antibodies has begun to revolutionize understandings of antibody-mediated antiviral activity. As a result, the set of broadly neutralizing and highly protective antibodies has grown in number, diversity, potency, and breadth of viral recognition and neutralization. These antibodies are now being further enhanced by rational engineering of their anti-HIV activities and coupled to cutting edge gene delivery and strategies to optimize their pharmacokinetics and biodistribution. As a result, the prospects for clinical use of HIV-specific antibodies to treat, clear, and prevent HIV infection are gaining momentum. Here we discuss the diverse methods whereby antibodies are being optimized for neutralization potency and breadth, biodistribution, pharmacokinetics, and effector function with the aim of revolutionizing HIV treatment and prevention options.
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139
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Krauss IJ. Antibody recognition of HIV and dengue glycoproteins. Glycobiology 2016; 26:813-9. [PMID: 26941393 PMCID: PMC5018046 DOI: 10.1093/glycob/cww031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 02/12/2016] [Accepted: 02/29/2016] [Indexed: 01/13/2023] Open
Abstract
The last 6 years have witnessed an explosion of discoveries at the interface of glycobiology and immunology. Binding of clustered oligosaccharides has turned out to be a very frequent mode by which human antibodies have developed broadly neutralizing activity against HIV. This mini-review will cover many recent developments in the HIV antibody field, as well as emerging data about Dengue broadly neutralizing antibodies.
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Affiliation(s)
- Isaac J Krauss
- Department of Chemistry, Brandeis University, Waltham, MA 02454, USA
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140
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Marchetti R, Perez S, Arda A, Imberty A, Jimenez‐Barbero J, Silipo A, Molinaro A. "Rules of Engagement" of Protein-Glycoconjugate Interactions: A Molecular View Achievable by using NMR Spectroscopy and Molecular Modeling. ChemistryOpen 2016; 5:274-96. [PMID: 27547635 PMCID: PMC4981046 DOI: 10.1002/open.201600024] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Indexed: 12/20/2022] Open
Abstract
Understanding the dynamics of protein-ligand interactions, which lie at the heart of host-pathogen recognition, represents a crucial step to clarify the molecular determinants implicated in binding events, as well as to optimize the design of new molecules with therapeutic aims. Over the last decade, advances in complementary biophysical and spectroscopic methods permitted us to deeply dissect the fine structural details of biologically relevant molecular recognition processes with high resolution. This Review focuses on the development and use of modern nuclear magnetic resonance (NMR) techniques to dissect binding events. These spectroscopic methods, complementing X-ray crystallography and molecular modeling methodologies, will be taken into account as indispensable tools to provide a complete picture of protein-glycoconjugate binding mechanisms related to biomedicine applications against infectious diseases.
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Affiliation(s)
- Roberta Marchetti
- Department of Chemical SciencestUniversity of Napoli Federico IIVia Cintia 480126NapoliItaly
| | - Serge Perez
- Department Molecular Pharmacochemistry UMR 5063CNRS and University of GrenobleAlpes, BP 5338041 Grenoble cedex 9France
| | - Ana Arda
- Bizkaia Technological ParkCIC bioGUNEBuilding 801A-148160Derio-BizkaiaSpain
| | - Anne Imberty
- Centre de Recherche sur les CNRSand University of Grenoble Macromolécules Végétales, UPR 5301Alpes, BP 5338041Grenoble cedex 9France
| | | | - Alba Silipo
- Department of Chemical SciencestUniversity of Napoli Federico IIVia Cintia 480126NapoliItaly
| | - Antonio Molinaro
- Department of Chemical SciencestUniversity of Napoli Federico IIVia Cintia 480126NapoliItaly
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141
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Gasser R, Hamoudi M, Pellicciotta M, Zhou Z, Visdeloup C, Colin P, Braibant M, Lagane B, Negroni M. Buffering deleterious polymorphisms in highly constrained parts of HIV-1 envelope by flexible regions. Retrovirology 2016; 13:50. [PMID: 27473399 PMCID: PMC4967302 DOI: 10.1186/s12977-016-0285-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/18/2016] [Indexed: 02/07/2023] Open
Abstract
Background Covariation is an essential process that leads to coevolution of parts of proteins and genomes. In organisms subject to strong selective pressure, coevolution is central to keep the balance between the opposite requirements of antigenic variation and retention of functionality. Being the viral component most exposed to the external environment, the HIV-1 glycoprotein gp120 constitutes the main target of the immune response. Accordingly its more external portions are characterised by extensive sequence heterogeneity fostering constant antigenic variation. Results We report that a single polymorphism, present at the level of the viral population in the conserved internal region C2, was sufficient to totally abolish Env functionality when introduced in an exogenous genetic context. The prominent defect of the non-functional protein is a block occurring after recognition of the co-receptor CCR5, likely due to an interference with the subsequent conformational changes that lead to membrane fusion. We also report that the presence of compensatory polymorphisms at the level of the external and hypervariable region V3 fully restored the functionality of the protein. The functional revertant presents different antigenic profiles and sensitivity to the entry inhibitor TAK 779. Conclusions Our data suggest that variable regions, besides harbouring intrinsic extensive antigenic diversity, can also contribute to sequence diversification in more structurally constrained parts of the gp120 by buffering the deleterious effect of polymorphisms, further increasing the genetic flexibility of the protein and the antigenic repertoire of the viral population.
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Affiliation(s)
- Romain Gasser
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France
| | - Meriem Hamoudi
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France.,U1016, UMR 8104, INSERM-CNRS, Institut Cochin, Université Paris Descartes, Paris, France
| | - Martina Pellicciotta
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France
| | - Zhicheng Zhou
- INSERM U1108, Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
| | | | - Philippe Colin
- INSERM U1108, Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
| | | | - Bernard Lagane
- INSERM U1108, Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
| | - Matteo Negroni
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France.
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142
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van den Kerkhof TLGM, de Taeye SW, Boeser-Nunnink BD, Burton DR, Kootstra NA, Schuitemaker H, Sanders RW, van Gils MJ. HIV-1 escapes from N332-directed antibody neutralization in an elite neutralizer by envelope glycoprotein elongation and introduction of unusual disulfide bonds. Retrovirology 2016; 13:48. [PMID: 27388013 PMCID: PMC4936165 DOI: 10.1186/s12977-016-0279-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 06/21/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Current HIV-1 immunogens are unable to induce antibodies that can neutralize a broad range of HIV-1 (broadly neutralizing antibodies; bNAbs). However, such antibodies are elicited in 10-30 % of HIV-1 infected individuals, and the co-evolution of the virus and the humoral immune responses in these individuals has attracted attention, because they can provide clues for vaccine design. RESULTS Here we characterized the NAb responses and envelope glycoprotein evolution in an HIV-1 infected "elite neutralizer" of the Amsterdam Cohort Studies on HIV-1 infection and AIDS who developed an unusually potent bNAb response rapidly after infection. The NAb response was dependent on the N332-glycan and viral resistance against the N332-glycan dependent bNAb PGT135 developed over time but viral escape did not occur at or near this glycan. In contrast, the virus likely escaped by increasing V1 length, with up to 21 amino acids, accompanied by the introduction of 1-3 additional glycans, as well as 2-4 additional cysteine residues within V1. CONCLUSIONS In the individual studied here, HIV-1 escaped from N332-glycan directed NAb responses without changing the epitope itself, but by elongating a variable loop that shields this epitope.
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Affiliation(s)
- Tom L G M van den Kerkhof
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands.,Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Steven W de Taeye
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Brigitte D Boeser-Nunnink
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Dennis R Burton
- Department of Immunology and Microbial Science and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.,Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, 02139, USA
| | - Neeltje A Kootstra
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Hanneke Schuitemaker
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands.,Janssen Pharmaceuticals, 2333 CN, Leiden, The Netherlands
| | - Rogier W Sanders
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands. .,Department of Microbiology and Immunology, Weill Medical College, Cornell University, New York, NY, 10065, USA.
| | - Marit J van Gils
- Department of Microbiology and Immunology, Weill Medical College, Cornell University, New York, NY, 10065, USA.
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143
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Toonstra C, Amin MN, Wang LX. Site-Selective Chemoenzymatic Glycosylation of an HIV-1 Polypeptide Antigen with Two Distinct N-Glycans via an Orthogonal Protecting Group Strategy. J Org Chem 2016; 81:6176-85. [PMID: 27380452 DOI: 10.1021/acs.joc.6b01044] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A convergent chemoenzymatic approach for sequential installation of different N-glycans in a polypeptide is described. The method includes introduction of distinguishably protected GlcNAc-Asn building blocks during automated solid phase peptide synthesis (SPPS), followed by orthogonal deprotection of the GlcNAc primers and site-selective sequential extension of the sugar chains through glycosynthase-catalyzed transglycosylation reactions. It was observed that the protecting groups on one neighboring GlcNAc moiety have an impact on the substrate activity of another GlcNAc acceptor toward some endoglycosynthases in transglycosylation. The usefulness of this synthetic strategy was exemplified by an efficient synthesis of the glycopeptide neutralizing epitope of broadly HIV-neutralizing antibody PG9. The method should be generally applicable for the synthesis of complex glycopeptides carrying multiple different N-glycans.
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Affiliation(s)
- Christian Toonstra
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Mohammed N Amin
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Lai-Xi Wang
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
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144
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Presenting native-like trimeric HIV-1 antigens with self-assembling nanoparticles. Nat Commun 2016; 7:12041. [PMID: 27349934 PMCID: PMC4931238 DOI: 10.1038/ncomms12041] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/24/2016] [Indexed: 01/01/2023] Open
Abstract
Structures of BG505 SOSIP.664 trimer in complex with broadly neutralizing antibodies (bNAbs) have revealed the critical role of trimeric context for immune recognition of HIV-1. Presentation of trimeric HIV-1 antigens on nanoparticles may thus provide promising vaccine candidates. Here we report the rational design, structural analysis and antigenic evaluation of HIV-1 trimer-presenting nanoparticles. We first demonstrate that both V1V2 and gp120 can be presented in native-like trimeric conformations on nanoparticles. We then design nanoparticles presenting various forms of stabilized gp140 trimer based on ferritin and a large, 60-meric E2p that displays 20 spikes mimicking virus-like particles (VLPs). Particle assembly is confirmed by electron microscopy (EM), while antigenic profiles are generated using representative bNAbs and non-NAbs. Lastly, we demonstrate high-yield gp140 nanoparticle production and robust stimulation of B cells carrying cognate VRC01 receptors by gp120 and gp140 nanoparticles. Together, our study provides an arsenal of multivalent immunogens for HIV-1 vaccine development.
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145
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Cimbro R, Peterson FC, Liu Q, Guzzo C, Zhang P, Miao H, Van Ryk D, Ambroggio X, Hurt DE, De Gioia L, Volkman BF, Dolan MA, Lusso P. Tyrosine-sulfated V2 peptides inhibit HIV-1 infection via coreceptor mimicry. EBioMedicine 2016; 10:45-54. [PMID: 27389109 PMCID: PMC5006643 DOI: 10.1016/j.ebiom.2016.06.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/15/2016] [Accepted: 06/24/2016] [Indexed: 11/06/2022] Open
Abstract
Tyrosine sulfation is a post-translational modification that facilitates protein-protein interaction. Two sulfated tyrosines (Tys173 and Tys177) were recently identified within the second variable (V2) loop of the major HIV-1 envelope glycoprotein, gp120, and shown to contribute to stabilizing the intramolecular interaction between V2 and the third variable (V3) loop. Here, we report that tyrosine-sulfated peptides derived from V2 act as structural and functional mimics of the CCR5 N-terminus and potently block HIV-1 infection. Nuclear magnetic and surface plasmon resonance analyses indicate that a tyrosine-sulfated V2 peptide (pV2α-Tys) adopts a CCR5-like helical conformation and directly interacts with gp120 in a CD4-dependent fashion, competing with a CCR5 N-terminal peptide. Sulfated V2 mimics, but not their non-sulfated counterparts, inhibit HIV-1 entry and fusion by preventing coreceptor utilization, with the highly conserved C-terminal sulfotyrosine, Tys177, playing a dominant role. Unlike CCR5 N-terminal peptides, V2 mimics inhibit a broad range of HIV-1 strains irrespective of their coreceptor tropism, highlighting the overall structural conservation of the coreceptor-binding site in gp120. These results document the use of receptor mimicry by a retrovirus to occlude a key neutralization target site and provide leads for the design of therapeutic strategies against HIV-1. Tyrosine-sulfated peptides derived from the V2 domain of HIV-1 gp120 mimic the N-terminal domain of the CCR5 coreceptor. Tyrosine-sulfated V2 peptides are potent and broad-spectrum inhibitors of HIV-1 infection.
Understanding how HIV-1 protects its outer envelope from the immune system may help devise effective strategies for treatment and vaccine. We derived synthetic peptides from the V2 loop of the external HIV-1 envelope glycoprotein, gp120, which contains sulfate-modified tyrosines that contribute to maintaining the envelope in an antibody-protected configuration. We found that these peptides mimic the structure and function of CCR5, a key cellular coreceptor for HIV-1, interacting with and occluding a major CCR5-binding site in gp120. Tyrosine-sulfated V2 peptides potently block HIV-1 entry and may serve as templates for the design of new antiviral inhibitors.
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Affiliation(s)
- Raffaello Cimbro
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Qingbo Liu
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Christina Guzzo
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Peng Zhang
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Huiyi Miao
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Donald Van Ryk
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Xavier Ambroggio
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Darrell E Hurt
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Luca De Gioia
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Michael A Dolan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Paolo Lusso
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA.
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146
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Morgand M, Bouvin-Pley M, Plantier JC, Moreau A, Alessandri E, Simon F, Pace CS, Pancera M, Ho DD, Poignard P, Bjorkman PJ, Mouquet H, Nussenzweig MC, Kwong PD, Baty D, Chames P, Braibant M, Barin F. V1/V2 Neutralizing Epitope is Conserved in Divergent Non-M Groups of HIV-1. J Acquir Immune Defic Syndr 2016; 71:237-45. [PMID: 26413851 PMCID: PMC4770367 DOI: 10.1097/qai.0000000000000854] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Supplemental Digital Content is Available in the Text. Background: Highly potent broadly neutralizing monoclonal antibodies (bNAbs) have been obtained from individuals infected by HIV-1 group M variants. We analyzed the cross-group neutralization potency of these bNAbs toward non-M primary isolates (PI). Material and Methods: The sensitivity to neutralization was analyzed in a neutralization assay using TZM-bl cells. Twenty-three bNAbs were used, including reagents targeting the CD4-binding site, the N160 glycan-V1/V2 site, the N332 glycan-V3 site, the membrane proximal external region of gp41, and complex epitopes spanning both env subunits. Two bispecific antibodies that combine the inhibitory activity of an anti-CD4 with that of PG9 or PG16 bNAbs were included in the study (PG9-iMab and PG16-iMab). Results: Cross-group neutralization was observed only with the bNAbs targeting the N160 glycan-V1/V2 site. Four group O PIs, 1 group N PI, and the group P PI were neutralized by PG9 and/or PG16 or PGT145 at low concentrations (0.04–9.39 μg/mL). None of the non-M PIs was neutralized by the bNAbs targeting other regions at the highest concentration tested, except 10E8 that neutralized weakly 2 group N PIs and 35O22 that neutralized 1 group O PI. The bispecific bNAbs neutralized very efficiently all the non-M PIs with IC50 below 1 μg/mL, except 2 group O strains. Conclusion: The N160 glycan-V1/V2 site is the most conserved neutralizing site within the 4 groups of HIV-1. This makes it an interesting target for the development of HIV vaccine immunogens. The corresponding bNAbs may be useful for immunotherapeutic strategies in patients infected by non-M variants.
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Affiliation(s)
- Marion Morgand
- *Université François Rabelais, Inserm U966, Tours, France; †Université de Rouen and CHU Charles Nicolle, Rouen, France; ‡Laboratoire de Virologie, Hôpital St Louis, Paris, France; §Aaron Diamond AIDS Research Center, The Rockefeller University, New York, NY; ‖Vaccine Research Center, National Institutes of Health, Bethesda, MD; ¶Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA; #California Institute of Technology, CA; **Laboratory of Humoral Response to Pathogens, Department of Immunology, Institut Pasteur, Paris, France; ††Howard Hughes Medical Institute, The Rockefeller University, New York, NY; ‡‡CRCM, Inserm U1068; Institut Paoli-Calmettes; CNRS UMR7258; AMU UM105; Marseille, France; and §§Laboratoire de Bactériologie-Virologie, Centre National de Référence du VIH, CHU Bretonneau, Tours, France
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147
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Yang M, Huang J, MacKerell AD. Enhanced conformational sampling using replica exchange with concurrent solute scaling and hamiltonian biasing realized in one dimension. J Chem Theory Comput 2016; 11:2855-67. [PMID: 26082676 PMCID: PMC4463548 DOI: 10.1021/acs.jctc.5b00243] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Indexed: 12/17/2022]
Abstract
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Replica exchange (REX) is a powerful
computational tool for overcoming
the quasi-ergodic sampling problem of complex molecular systems. Recently,
several multidimensional extensions of this method have been developed
to realize exchanges in both temperature and biasing potential space
or the use of multiple biasing potentials to improve sampling efficiency.
However, increased computational cost due to the multidimensionality
of exchanges becomes challenging for use on complex systems under
explicit solvent conditions. In this study, we develop a one-dimensional
(1D) REX algorithm to concurrently combine the advantages of overall
enhanced sampling from Hamiltonian solute scaling and the specific
enhancement of collective variables using Hamiltonian biasing potentials.
In the present Hamiltonian replica exchange method, termed HREST-BP,
Hamiltonian solute scaling is applied to the solute subsystem, and
its interactions with the environment to enhance overall conformational
transitions and biasing potentials are added along selected collective
variables associated with specific conformational transitions, thereby
balancing the sampling of different hierarchical degrees of freedom.
The two enhanced sampling approaches are implemented concurrently
allowing for the use of a small number of replicas (e.g., 6 to 8)
in 1D, thus greatly reducing the computational cost in complex system
simulations. The present method is applied to conformational sampling
of two nitrogen-linked glycans (N-glycans) found
on the HIV gp120 envelope protein. Considering the general importance
of the conformational sampling problem, HREST-BP represents an efficient
procedure for the study of complex saccharides, and, more generally,
the method is anticipated to be of general utility for the conformational
sampling in a wide range of macromolecular systems.
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Affiliation(s)
- Mingjun Yang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, United States
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148
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Wu X, Kong XP. Antigenic landscape of the HIV-1 envelope and new immunological concepts defined by HIV-1 broadly neutralizing antibodies. Curr Opin Immunol 2016; 42:56-64. [PMID: 27289425 DOI: 10.1016/j.coi.2016.05.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/20/2016] [Indexed: 10/21/2022]
Abstract
The isolation of HIV-1 broadly neutralizing antibodies (bnAbs) has demonstrated the ability of the human immune system to mount effective antibody responses against the virus. To harness this immune potential to elicit similar antibody responses by vaccination, it is important to understand the immunological processes that produce them. Here we review recent advances in crystal structural determinations of HIV-1 bnAb epitopes that directly portray the antigenic landscape of the HIV-1 envelope glycoprotein. We also summarize new immunological concepts implicated in bnAb sequences and their lineage studies.
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Affiliation(s)
- Xueling Wu
- Aaron Diamond AIDS Research Center, New York, NY 10016, USA.
| | - Xiang-Peng Kong
- New York University, School of Medicine, New York, NY 10016, USA.
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149
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Kong R, Xu K, Zhou T, Acharya P, Lemmin T, Liu K, Ozorowski G, Soto C, Taft JD, Bailer RT, Cale EM, Chen L, Choi CW, Chuang GY, Doria-Rose NA, Druz A, Georgiev IS, Gorman J, Huang J, Joyce MG, Louder MK, Ma X, McKee K, O'Dell S, Pancera M, Yang Y, Blanchard SC, Mothes W, Burton DR, Koff WC, Connors M, Ward AB, Kwong PD, Mascola JR. Fusion peptide of HIV-1 as a site of vulnerability to neutralizing antibody. Science 2016; 352:828-33. [PMID: 27174988 DOI: 10.1126/science.aae0474] [Citation(s) in RCA: 263] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/30/2016] [Indexed: 12/13/2022]
Abstract
The HIV-1 fusion peptide, comprising 15 to 20 hydrophobic residues at the N terminus of the Env-gp41 subunit, is a critical component of the virus-cell entry machinery. Here, we report the identification of a neutralizing antibody, N123-VRC34.01, which targets the fusion peptide and blocks viral entry by inhibiting conformational changes in gp120 and gp41 subunits of Env required for entry. Crystal structures of N123-VRC34.01 liganded to the fusion peptide, and to the full Env trimer, revealed an epitope consisting of the N-terminal eight residues of the gp41 fusion peptide and glycan N88 of gp120, and molecular dynamics showed that the N-terminal portion of the fusion peptide can be solvent-exposed. These results reveal the fusion peptide to be a neutralizing antibody epitope and thus a target for vaccine design.
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Affiliation(s)
- Rui Kong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kai Xu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Priyamvada Acharya
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas Lemmin
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Kevin Liu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gabriel Ozorowski
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA. International AIDS Vaccine Initiative, Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Cinque Soto
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Justin D Taft
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert T Bailer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Evan M Cale
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lei Chen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chang W Choi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Aliaksandr Druz
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ivelin S Georgiev
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jinghe Huang
- HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - M Gordon Joyce
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mark K Louder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaochu Ma
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Krisha McKee
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sijy O'Dell
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marie Pancera
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yongping Yang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10021, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Dennis R Burton
- Department of Immunology and Microbial Science, International AIDS Vaccine Initiative Neutralizing Antibody Center, Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA. Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA 02142, USA
| | - Wayne C Koff
- International AIDS Vaccine Initiative, New York, NY 10038, USA
| | - Mark Connors
- HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA. International AIDS Vaccine Initiative, Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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150
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Report of the Cent Gardes HIV Vaccines Conference. Part 1: The antibody response; Fondation Mérieux Conference Center, Veyrier-du-Lac, France, 25-27 October 2015. Vaccine 2016; 34:3557-61. [PMID: 27216761 DOI: 10.1016/j.vaccine.2016.05.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/13/2016] [Accepted: 05/10/2016] [Indexed: 01/10/2023]
Abstract
The 2015 Cent Gardes Conference on HIV vaccines took place on October 25-27 at the Merieux Foundation Conference Center in Veyrier du Lac, near Annecy, France. The meeting reviewed progress in the development of HIV vaccines and identified new directions of future research. The field has advanced incrementally over the past year but major progress will require additional information from new clinical trials. In this article, we review the presentations on humoral immune responses to HIV, and highlight the difficulty of eliciting broadly neutralizing antibodies by vaccination. Advances in cellular immunity for HIV prevention will be reviewed separately, in a following article.
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