1
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Lecerf M, Lacombe RV, Dimitrov JD. Polyreactivity of antibodies from different B-cell subpopulations is determined by distinct sequence patterns of variable region. Front Immunol 2023; 14:1266668. [PMID: 38077343 PMCID: PMC10710144 DOI: 10.3389/fimmu.2023.1266668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/25/2023] [Indexed: 12/18/2023] Open
Abstract
An antibody molecule that can bind to multiple distinct antigens is defined as polyreactive. In the present study, we performed statistical analyses to assess sequence correlates of polyreactivity of >600 antibodies cloned from different B-cell types of healthy humans. The data revealed several sequence patterns of variable regions of heavy and light immunoglobulin chains that determine polyreactivity. The most prominent identified patterns were increased number of basic amino acid residues, reduced frequency of acidic residues, increased number of aromatic and hydrophobic residues, and longer length of CDR L1. Importantly, our study revealed that antibodies isolated from different B-cell populations used distinct sequence patterns (or combinations of them) for polyreactive antigen binding. Furthermore, we combined the data from sequence analyses with molecular modeling of selected polyreactive antibodies and demonstrated that human antibodies can use multiple pathways for achieving antigen-binding promiscuity. These data reconcile some contradictions in the literature regarding the determinants of antibody polyreactivity. Moreover, our study demonstrates that the mechanism of polyreactivity of antibodies evolves during immune response and might be tailored to specific functional properties of different B-cell compartments. Finally, these data can be of use for efforts in the development and engineering of therapeutic antibodies.
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Affiliation(s)
| | | | - Jordan D. Dimitrov
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
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2
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Zhang Y, Li Q, Luo L, Duan C, Shen J, Wang Z. Application of germline antibody features to vaccine development, antibody discovery, antibody optimization and disease diagnosis. Biotechnol Adv 2023; 65:108143. [PMID: 37023966 DOI: 10.1016/j.biotechadv.2023.108143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/26/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023]
Abstract
Although the efficacy and commercial success of vaccines and therapeutic antibodies have been tremendous, designing and discovering new drug candidates remains a labor-, time- and cost-intensive endeavor with high risks. The main challenges of vaccine development are inducing a strong immune response in broad populations and providing effective prevention against a group of highly variable pathogens. Meanwhile, antibody discovery faces several great obstacles, especially the blindness in antibody screening and the unpredictability of the developability and druggability of antibody drugs. These challenges are largely due to poorly understanding of germline antibodies and the antibody responses to pathogen invasions. Thanks to the recent developments in high-throughput sequencing and structural biology, we have gained insight into the germline immunoglobulin (Ig) genes and germline antibodies and then the germline antibody features associated with antigens and disease manifestation. In this review, we firstly outline the broad associations between germline antibodies and antigens. Moreover, we comprehensively review the recent applications of antigen-specific germline antibody features, physicochemical properties-associated germline antibody features, and disease manifestation-associated germline antibody features on vaccine development, antibody discovery, antibody optimization, and disease diagnosis. Lastly, we discuss the bottlenecks and perspectives of current and potential applications of germline antibody features in the biotechnology field.
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Affiliation(s)
- Yingjie Zhang
- National Key Laboratory of Veterinary Public Health Security, Beijing Key Laboratory of Detection Technology for Animal-Derived Food, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, People's Republic of China
| | - Qing Li
- National Key Laboratory of Veterinary Public Health Security, Beijing Key Laboratory of Detection Technology for Animal-Derived Food, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, People's Republic of China
| | - Liang Luo
- National Key Laboratory of Veterinary Public Health Security, Beijing Key Laboratory of Detection Technology for Animal-Derived Food, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, People's Republic of China
| | - Changfei Duan
- National Key Laboratory of Veterinary Public Health Security, Beijing Key Laboratory of Detection Technology for Animal-Derived Food, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, People's Republic of China
| | - Jianzhong Shen
- National Key Laboratory of Veterinary Public Health Security, Beijing Key Laboratory of Detection Technology for Animal-Derived Food, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, People's Republic of China
| | - Zhanhui Wang
- National Key Laboratory of Veterinary Public Health Security, Beijing Key Laboratory of Detection Technology for Animal-Derived Food, College of Veterinary Medicine, China Agricultural University, 100193 Beijing, People's Republic of China.
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3
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Plum M, Tjerrild L, Raiber T, Bantleon F, Bantleon S, Miehe M, Jabs F, Seismann H, Möbs C, Pfützner W, Jakob T, Andersen GR, Spillner E. Structural and functional analyses of antibodies specific for modified core N-glycans suggest a role in T H 2 responses. Allergy 2023; 78:121-130. [PMID: 35726192 PMCID: PMC10083920 DOI: 10.1111/all.15417] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 04/19/2022] [Accepted: 05/20/2022] [Indexed: 12/29/2022]
Abstract
BACKGROUND Immune responses to N-glycan structures from allergens and parasites are often associated with pronounced, high affinity IgE reactivities. Cross-reactive carbohydrate determinants (CCDs) are constituted by modified N-glycan core structures and represent the most frequently recognized epitopes in allergic immune responses. Although recently accepted as potentially allergenic epitopes, the biological and clinical relevance as well as structural and functional characteristics of CCD-specific antibodies remain elusive. METHODS In order to gain structural insights into the recognition of CCDs, two specific antibody fragments were isolated from a leporid immune repertoire library and converted into human/leporid IgE and IgG formats. The antibody formats were assessed by ELISA and surface plasmon resonance, structural and functional analyses were performed by X-ray crystallography, mediator release, and ELIFAB assays. RESULTS The recombinant IgE exhibited highly specific interactions with different types of CCDs on numerous CCD-carrying glycoproteins. Crystal structures of two CCD-specific antibodies, one of which in complex with a CCD-derived disaccharide emphasize that mechanisms of core glycan epitope recognition are as specific as those governing protein epitope recognition. The rIgE triggered immediate cellular responses via FcεRI cross-linking and mediated facilitated antigen presentation by binding of IgE/antigen complexes to CD23, a process that also could be blocked by IgG of allergic patients. CONCLUSIONS Our study provides evidence for the relevance of N-glycan recognition in TH 2 responses and corroborates that IgE and IgG antibodies to ubiquitous carbohydrate epitopes can be equivalent to those directed against proteinaceous epitopes with implications for diagnostic and immunotherapeutic concepts.
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Affiliation(s)
- Melanie Plum
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark.,Division of Clinical and Molecular Allergology, Research Center Borstel, Leibniz Lung Center, German Center for Lung Research (DZL), Borstel, Germany
| | - Luna Tjerrild
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Tim Raiber
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark.,Institute of Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Frank Bantleon
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Sara Bantleon
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark.,Institute of Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Michaela Miehe
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Frederic Jabs
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark.,Institute of Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Henning Seismann
- Department of Oncology and Hematology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Möbs
- Clinical & Experimental Allergology, Department of Dermatology and Allergology, Philipps University Marburg, Marburg, Germany
| | - Wolfgang Pfützner
- Clinical & Experimental Allergology, Department of Dermatology and Allergology, Philipps University Marburg, Marburg, Germany
| | - Thilo Jakob
- Department of Dermatology and Allergy, University Medical Center Giessen, Justus Liebig University, Giessen, Germany
| | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Edzard Spillner
- Immunological Biotechnology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
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4
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Jaiswal D, Verma S, Nair DT, Salunke DM. Antibody multispecificity: A necessary evil? Mol Immunol 2022; 152:153-161. [DOI: 10.1016/j.molimm.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022]
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5
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Planchais C, Reyes‐Ruiz A, Lacombe R, Zarantonello A, Lecerf M, Revel M, Roumenina LT, Atanasov BP, Mouquet H, Dimitrov JD. Evolutionary trajectory of receptor binding specificity and promiscuity of the spike protein of SARS-CoV-2. Protein Sci 2022; 31:e4447. [PMID: 36305765 PMCID: PMC9597384 DOI: 10.1002/pro.4447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/08/2022] [Accepted: 09/12/2022] [Indexed: 01/27/2023]
Abstract
SARS-CoV-2 infects cells by attachment to its receptor-the angiotensin converting enzyme 2 (ACE2). Regardless of the wealth of structural data, little is known about the physicochemical mechanism of interactions of the viral spike (S) protein with ACE2 and how this mechanism has evolved during the pandemic. Here, we applied experimental and computational approaches to characterize the molecular interaction of S proteins from SARS-CoV-2 variants of concern (VOC). Data on kinetics, activation-, and equilibrium thermodynamics of binding of the receptor binding domain (RBD) from VOC with ACE2 as well as data from computational protein electrostatics revealed a profound remodeling of the physicochemical characteristics of the interaction during the evolution. Thus, as compared to RBDs from Wuhan strain and other VOC, Omicron RBD presented as a unique protein in terms of conformational dynamics and types of non-covalent forces driving the complex formation with ACE2. Viral evolution resulted in a restriction of the RBD structural dynamics, and a shift to a major role of polar forces for ACE2 binding. Further, we investigated how the reshaping of the physicochemical characteristics of interaction affects the binding specificity of S proteins. Data from various binding assays revealed that SARS-CoV-2 Wuhan and Omicron RBDs manifest capacity for promiscuous recognition of unrelated human proteins, but they harbor distinct reactivity patterns. These findings might contribute for mechanistic understanding of the viral tropism and capacity to evade immune responses during evolution.
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Affiliation(s)
- Cyril Planchais
- Laboratory of Humoral ImmunologyInstitut Pasteur, Université Paris Cité, INSERM U1222ParisFrance
| | - Alejandra Reyes‐Ruiz
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
| | - Robin Lacombe
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
| | - Alessandra Zarantonello
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
| | - Maxime Lecerf
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
| | - Margot Revel
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
| | - Lubka T. Roumenina
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
| | - Boris P. Atanasov
- Institute of Organic Chemistry, Bulgarian Academy of SciencesSofiaBulgaria
| | - Hugo Mouquet
- Laboratory of Humoral ImmunologyInstitut Pasteur, Université Paris Cité, INSERM U1222ParisFrance
| | - Jordan D. Dimitrov
- Centre de Recherche des CordeliersINSERM, CNRS, Sorbonne Université, Université de ParisParisFrance
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6
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Pashov A, Murali R, Makhoul I, Karbassi B, Kieber-Emmons T. Harnessing Antibody Polyspecificity for Cancer Immunotherapy. Monoclon Antib Immunodiagn Immunother 2022; 41:290-300. [PMID: 36306515 DOI: 10.1089/mab.2022.0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Targeting the diverse glycan repertoire expressed on tumor cells is considered a viable therapeutic strategy to deal with tumor cell heterogeneity. Inherently polyspecific, natural, glycan-reactive antibodies are purported to be protective in thwarting infections and in cancer immunotherapy. Tumor-associated carbohydrate antigens (TACAs) are related to pathogen glycans, to which nascent or natural antibodies exist and IgM responses are elicited. To capture the polyspecific nature of anticarbohydrate responses, we have focused on the rational design of carbohydrate mimetic peptides (CMPs) cross-reactive with TACA reactive antibodies. In particular, we have focused on the development of CMPs that display reactivity to GD2 and Lewis Y (LeY) reactive monoclonal antibodies. They would serve as templates for pan-immunogens inducing biosimilar polyreactive antibodies. In the design, we relied on structural analyses of CMP's enhanced binding to the templates using molecular modeling. Glycan reactivity patterns of affinity CMP-purified human antibodies further refined specificity profiles in comparison with the immune response to the CMP in clinical trials. In this study, we further define the molecular characteristics for this mimicry by considering the polyspecificity of LeY and GD2 reactive antibodies binding to the lacto-ceramide core Galβ(1,4)Glcβ(1-1')Cer. Binding to this minimum building block can be capitalized on for cancer therapy and diagnostics and illustrates a new approach in designing cancer vaccines taking advantage of the latent polyspecificity of antibodies and the relevance of natural antibodies in antigen discovery and design.
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Affiliation(s)
- Anastas Pashov
- Department of Immunology, Stephan Angelov Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Ramachandran Murali
- Research Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Issam Makhoul
- Department of Medicine and Pathology, Winthrop P. Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Behjatolah Karbassi
- Department of Medicine and Pathology, Winthrop P. Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Thomas Kieber-Emmons
- Department of Medicine and Pathology, Winthrop P. Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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7
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Blackler RJ, Müller-Loennies S, Pokorny-Lehrer B, Legg MSG, Brade L, Brade H, Kosma P, Evans SV. Antigen binding by conformational selection in near-germline antibodies. J Biol Chem 2022; 298:101901. [PMID: 35395245 PMCID: PMC9112003 DOI: 10.1016/j.jbc.2022.101901] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 01/20/2023] Open
Abstract
Conformational flexibility in antibody-combining sites has been hypothesized to facilitate polyspecificity toward multiple unique epitopes and enable the limited germline repertoire to match an overwhelming diversity of potential antigens; however, elucidating the mechanisms of antigen recognition by flexible antibodies has been understandably challenging. Here, multiple liganded and unliganded crystal structures of the near-germline anticarbohydrate antibodies S25–2 and S25–39 are reported, which reveal an unprecedented diversity of complementarity-determining region H3 conformations in apparent equilibrium. These structures demonstrate that at least some germline or near-germline antibodies are flexible entities sensitive to their chemical environments, with conformational selection available as an evolved mechanism that preserves the inherited ability to recognize common pathogens while remaining adaptable to new threats.
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Affiliation(s)
- Ryan J Blackler
- Department of Biochemistry and Microbiology, University of Victoria, Victoria BC, Canada
| | | | - Barbara Pokorny-Lehrer
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Max S G Legg
- Department of Biochemistry and Microbiology, University of Victoria, Victoria BC, Canada
| | - Lore Brade
- Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Helmut Brade
- Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Paul Kosma
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Stephen V Evans
- Department of Biochemistry and Microbiology, University of Victoria, Victoria BC, Canada.
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8
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DeLaitsch AT, Pridgen JR, Tytla A, Peach ML, Hu R, Farnsworth DW, McMillan AK, Flanagan N, Temme JS, Nicklaus MC, Gildersleeve JC. Selective Recognition of Carbohydrate Antigens by Germline Antibodies Isolated from AID Knockout Mice. J Am Chem Soc 2022; 144:4925-4941. [PMID: 35282679 PMCID: PMC10506689 DOI: 10.1021/jacs.1c12745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Germline antibodies, the initial set of antibodies produced by the immune system, are critical for host defense, and information about their binding properties can be useful for designing vaccines, understanding the origins of autoantibodies, and developing monoclonal antibodies. Numerous studies have found that germline antibodies are polyreactive with malleable, flexible binding pockets. While insightful, it remains unclear how broadly this model applies, as there are many families of antibodies that have not yet been studied. In addition, the methods used to obtain germline antibodies typically rely on assumptions and do not work well for many antibodies. Herein, we present a distinct approach for isolating germline antibodies that involves immunizing activation-induced cytidine deaminase (AID) knockout mice. This strategy amplifies antigen-specific B cells, but somatic hypermutation does not occur because AID is absent. Using synthetic haptens, glycoproteins, and whole cells, we obtained germline antibodies to an assortment of clinically important tumor-associated carbohydrate antigens, including Lewis Y, the Tn antigen, sialyl Lewis C, and Lewis X (CD15/SSEA-1). Through glycan microarray profiling and cell binding, we demonstrate that all but one of these germline antibodies had high selectivity for their glycan targets. Using molecular dynamics simulations, we provide insights into the structural basis of glycan recognition. The results have important implications for designing carbohydrate-based vaccines, developing anti-glycan monoclonal antibodies, and understanding antibody evolution within the immune system.
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Affiliation(s)
- Andrew T DeLaitsch
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Jacey R Pridgen
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Avery Tytla
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Megan L Peach
- Basic Science Program, Chemical Biology Laboratory, Leidos Biomedical Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Rayleen Hu
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - David W Farnsworth
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Aislinn K McMillan
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Natalie Flanagan
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - J Sebastian Temme
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Marc C Nicklaus
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
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9
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Obukhova P, Tsygankova S, Chinarev A, Shilova N, Nokel A, Kosma P, Bovin N. Are there specific antibodies against Neu5Gc epitopes in the blood of healthy individuals? Glycobiology 2021; 30:395-406. [PMID: 31897477 DOI: 10.1093/glycob/cwz107] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022] Open
Abstract
Strong discrepancies in published data on the levels and epitope specificities of antibodies against the xenogenic N-glycolyl forms of sialoglycans (Hanganutziu-Deicher Neu5Gcɑ2-3Galβ1-4Glc and related antigens) in healthy donors prompted us to carry out a systematic study in this area using the printed glycan array and other methods. This article summarizes and discusses our published and previously unpublished data, as well as publicly available data from the Consortium for Functional Glycomics. As a result, we conclude that (1) the level of antibodies referred to as anti-Neu5Gc in healthy individuals is low; (2) there are antibodies that seem to interact with Neu5Gc-containing epitopes, but in fact they recognize internal fragments of Neu5Gc-containing glycans (without sialic acids), which served as antigens in the assays used and; (3) a population capable of interacting specifically with Neu5Gc (it does not bind the corresponding NAc analogs) does exist, but it binds the monosaccharide Neu5Gc better than the entire glycans containing it. In other words, in healthy donors, there are populations of antibodies capable of binding the Neu5Gc monosaccharide or the inner core -Galβ1-4Glc, but very few true anti-Neu5Gcɑ2-3Galβ1-4Glc antibodies, i.e., antibodies capable of specifically recognizing the entire trisaccharide.
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Affiliation(s)
- Polina Obukhova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia.,Federal State Budget Institution, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Ministry of Healthcare of Russian Federation, 4 Oparin str., 117997, Moscow, Russia
| | - Svetlana Tsygankova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia
| | - Alexander Chinarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia
| | - Nadezhda Shilova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia.,Federal State Budget Institution, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Ministry of Healthcare of Russian Federation, 4 Oparin str., 117997, Moscow, Russia.,Semiotik LLC, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia
| | - Alexey Nokel
- Federal State Budget Institution, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Ministry of Healthcare of Russian Federation, 4 Oparin str., 117997, Moscow, Russia.,Semiotik LLC, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia
| | - Paul Kosma
- Department of Chemistry, University of Natural Resources and Life Sciences, 18 Muthgasse, 1190 Vienna, Austria, and
| | - Nicolai Bovin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, 117997 Moscow, Russia.,Auckland University of Technology, 55 Wellesley Street East, 1010, Auckland, New Zealand
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10
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Sangesland M, Yousif AS, Ronsard L, Kazer SW, Zhu AL, Gatter GJ, Hayward MR, Barnes RM, Quirindongo-Crespo M, Rohrer D, Lonberg N, Kwon D, Shalek AK, Lingwood D. A Single Human V H-gene Allows for a Broad-Spectrum Antibody Response Targeting Bacterial Lipopolysaccharides in the Blood. Cell Rep 2021; 32:108065. [PMID: 32846123 PMCID: PMC7446668 DOI: 10.1016/j.celrep.2020.108065] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/05/2020] [Accepted: 07/31/2020] [Indexed: 02/03/2023] Open
Abstract
B cell receptors (BCRs) display a combination of variable (V)-gene-encoded complementarity determining regions (CDRs) and adaptive/hypervariable CDR3 loops to engage antigens. It has long been proposed that the former tune for recognition of pathogens or groups of pathogens. To experimentally evaluate this within the human antibody repertoire, we perform immune challenges in transgenic mice that bear diverse human CDR3 and light chains but are constrained to different human VH-genes. We find that, of six commonly deployed VH sequences, only those CDRs encoded by IGHV1-2∗02 enable polyclonal antibody responses against bacterial lipopolysaccharide (LPS) when introduced to the bloodstream. The LPS is from diverse strains of gram-negative bacteria, and the VH-gene-dependent responses are directed against the non-variable and universal saccrolipid substructure of this antigen. This reveals a broad-spectrum anti-LPS response in which germline-encoded CDRs naturally hardwire the human antibody repertoire for recognition of a conserved microbial target.
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Affiliation(s)
- Maya Sangesland
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA
| | - Ashraf S Yousif
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA
| | - Larance Ronsard
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA
| | - Samuel W Kazer
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA; Institute for Medical Engineering and Science (IMES), Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Massachusetts Institute of Technology and Harvard, 415 Main St., Cambridge, MA 02142, USA
| | - Alex Lee Zhu
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA
| | - G James Gatter
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA; Institute for Medical Engineering and Science (IMES), Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Massachusetts Institute of Technology and Harvard, 415 Main St., Cambridge, MA 02142, USA
| | - Matthew R Hayward
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA
| | - Ralston M Barnes
- Bristol-Myers Squibb, 700 Bay Rd., Redwood City, CA 94063-2478, USA
| | | | - Daniel Rohrer
- Broad Institute of Massachusetts Institute of Technology and Harvard, 415 Main St., Cambridge, MA 02142, USA
| | - Nils Lonberg
- Bristol-Myers Squibb, 700 Bay Rd., Redwood City, CA 94063-2478, USA
| | - Douglas Kwon
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA; Division of Infectious Diseases, Massachusetts General Hospital. 55 Fruit St., Boston, MA 02114, USA
| | - Alex K Shalek
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA; Institute for Medical Engineering and Science (IMES), Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Massachusetts Institute of Technology and Harvard, 415 Main St., Cambridge, MA 02142, USA
| | - Daniel Lingwood
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, 400 Technology Square, Cambridge, MA 02139, USA.
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11
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A Structural Model for the Ligand Binding of Pneumococcal Serotype 3 Capsular Polysaccharide-Specific Protective Antibodies. mBio 2021; 12:e0080021. [PMID: 34061603 PMCID: PMC8262990 DOI: 10.1128/mbio.00800-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Capsular polysaccharides (CPSs) are major virulence factors that decorate the surfaces of many human bacterial pathogens. In their pure form or as glycoconjugate vaccines, CPSs are extensively used in vaccines deployed in clinical practice worldwide. However, our understanding of the structural requirements for interactions between CPSs and antibodies is limited. A longstanding model based on comprehensive observations of antibody repertoires binding to CPSs is that antibodies expressing heavy chain variable gene family 3 (VH3) predominate in these binding interactions in humans and VH3 homologs in mice. Toward understanding this highly conserved interaction, we generated a panel of mouse monoclonal antibodies (MAb) against Streptococcus pneumoniae serotype 3 CPS, determined an X-ray crystal structure of a protective MAb in complex with a hexasaccharide derived from enzymatic hydrolysis of the polysaccharide, and elucidated the structural requirements for this binding interaction. The crystal structure revealed a binding pocket containing aromatic side chains, suggesting the importance of hydrophobicity in the interaction. Through mutational analysis, we determined the amino acids that are critical in carbohydrate binding. Through elucidating the structural and functional properties of a panel of murine MAbs, we offer an explanation for the predominant use of the human VH3 gene family in antibodies against CPSs with implications in knowledge-based vaccine design.
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12
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Gómez-Redondo M, Ardá A, Gimeno A, Jiménez-Barbero J. Bacterial polysaccharides: conformation, dynamics and molecular recognition by antibodies. DRUG DISCOVERY TODAY. TECHNOLOGIES 2021; 35-36:1-11. [PMID: 33388123 DOI: 10.1016/j.ddtec.2020.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023]
Abstract
Bacterial infections are the cause of different severe health conditions and new therapies to combat these pathogens have been widely investigated. Carbohydrates, being complex structures covering the surface of bacteria, are considered relevant targets for antibody and vaccine development. The biological activities in pathogenesis of bacterial capsular polysaccharides and lipopolisaccharides and their unique structures have boosted the study of the minimal antigenic binding epitopes and the structural details of antibody-carbohydrate recognition. This review describes the most recent advances on the field, examining the structure, conformation and dynamics of relevant bacterial carbohydrates and their complexes with antibodies. The understanding of key factors governing the recognition process is fundamental for the progress toward the development of specific and efficient bacterial therapeutics.
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Affiliation(s)
- Marcos Gómez-Redondo
- CIC bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain
| | - Ana Ardá
- CIC bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain
| | - Ana Gimeno
- CIC bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain
| | - Jesús Jiménez-Barbero
- CIC bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain; Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain; Department Organic Chemistry II, Faculty of Science and technology, UPV-EHU, 48940 Leioa, Spain
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13
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Hils M, Wölbing F, Hilger C, Fischer J, Hoffard N, Biedermann T. The History of Carbohydrates in Type I Allergy. Front Immunol 2020; 11:586924. [PMID: 33163001 PMCID: PMC7583601 DOI: 10.3389/fimmu.2020.586924] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/07/2020] [Indexed: 12/20/2022] Open
Abstract
Although first described decades ago, the relevance of carbohydrate specific antibodies as mediators of type I allergy had not been recognized until recently. Previously, allergen specific IgE antibodies binding to carbohydrate epitopes were considered to demonstrate a clinically irrelevant cross-reactivity. However, this changed following the discovery of type I allergies specifically mediated by oligosaccharide structures. Especially the emerging understanding of red meat allergy characterized by IgE directed to the oligosaccharide alpha-gal showed that carbohydrate-mediated reactions can result in life threatening systemic anaphylaxis which in contrast to former assumptions proves a high clinical relevance of some carbohydrate allergens. Within the scope of this review article, we illustrate the historical development of carbohydrate-allergen-research, reaching from only diagnostically relevant crossreactive-carbohydrate-determinants to clinically important antigens mediating type I allergy. Focusing on clinical and immunological features of the alpha-gal syndrome, we highlight the discovery of oligosaccharides as potentially highly immunogenic antigens and mediators of type I allergy, report what is known about the route of sensitization and the immunological mechanisms involved in sensitization and elicitation phase of allergic responses as well as currently available diagnostic and therapeutic tools. Finally, we briefly report on carbohydrates being involved in type I allergies different from alpha-gal.
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Affiliation(s)
- Miriam Hils
- Department of Dermatology and Allergy Biederstein, School of Medicine, Technical University of Munich, Munich, Germany
| | - Florian Wölbing
- Department of Dermatology and Allergy Biederstein, School of Medicine, Technical University of Munich, Munich, Germany
| | - Christiane Hilger
- Department of Infection and Immunity, Luxembourg Institute of Health (LIH), Esch-sur-Alzette, Luxembourg
| | - Jörg Fischer
- Department of Dermatology, Faculty of Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Nils Hoffard
- Department of Dermatology and Allergy Biederstein, School of Medicine, Technical University of Munich, Munich, Germany
| | - Tilo Biedermann
- Department of Dermatology and Allergy Biederstein, School of Medicine, Technical University of Munich, Munich, Germany
- Clinical Unit Allergology, Helmholtz Zentrum München, German Research Center for Environmental 10 Health GmbH, Neuherberg, Germany
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14
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Antibody recognition of bacterial surfaces and extracellular polysaccharides. Curr Opin Struct Biol 2019; 62:48-55. [PMID: 31874385 DOI: 10.1016/j.sbi.2019.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/21/2019] [Accepted: 12/02/2019] [Indexed: 01/08/2023]
Abstract
Because of the ongoing increase in antibiotic-resistant microbes, new strategies such as therapeutic antibodies and effective vaccines are required. Bacterial carbohydrates are known to be particularly antigenic, and several monoclonal antibodies that target bacterial polysaccharides have been generated, with more in current development. This review examines the known 3D crystal structures of anti-bacterial antibodies and the structural basis for carbohydrate recognition and explores the potential mechanisms for antibody-dependent bacterial cell death. Understanding the key interactions between an antibody and its polysaccharide target on the surface of bacteria or in biofilms can provide essential information for the development of more specific and effective antibody therapeutics as well as carbohydrate-based vaccines.
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15
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Lecerf M, Kanyavuz A, Lacroix-Desmazes S, Dimitrov JD. Sequence features of variable region determining physicochemical properties and polyreactivity of therapeutic antibodies. Mol Immunol 2019; 112:338-346. [DOI: 10.1016/j.molimm.2019.06.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/17/2019] [Accepted: 06/17/2019] [Indexed: 12/17/2022]
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16
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Trattnig N, Blaukopf M, Bruxelle JF, Pantophlet R, Kosma P. Synthesis of an Undecasaccharide Featuring an Oligomannosidic Heptasaccharide and a Bacterial Kdo-lipid A Backbone for Eliciting Neutralizing Antibodies to Mammalian Oligomannose on the HIV-1 Envelope Spike. J Am Chem Soc 2019; 141:7946-7954. [PMID: 31010286 PMCID: PMC6524000 DOI: 10.1021/jacs.9b02872] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
![]()
Lipooligosaccharides (LOS) from the
bacterium Rhizobium
radiobacter Rv3 are structurally related to antigenic mammalian
oligomannoses on the HIV-1 envelope glycoprotein spike that are targets
for broadly neutralizing antibodies. Here, we prepared a hybrid structure
of viral and bacterial epitopes as part of a vaccine design strategy
to elicit oligomannose-specific HIV-neutralizing antibodies using
glycoconjugates based on the Rv3 LOS structure. Starting from a Kdo2GlcNAc2 tetrasaccharide precursor, a central orthogonally
protected mannose trichloroacetimidate donor was coupled to OH-5 of
the innermost Kdo residue. To assemble larger glycans, the N-acetylamino groups of the glucosamine units were converted
to imides to prevent formation of unwanted imidate byproducts. Blockwise
coupling of the pentasaccharide acceptor with an α-(1→2)-linked
mannotriosyl trichloroacetimidate donor introduced the D1-arm fragment.
Glycosylation of O-6 of the central branching mannose
with an α-(1→2)-α-(1→6)-linked mannotriosyl
trichloroacetimidate donor unit then furnished the undecasaccharide
harboring a D3-arm extension. Global deprotection yielded the 3-aminopropyl
ligand, which was activated as an isothiocyanate or adipic acid succinimidoyl
ester and conjugated to CRM197. However, representative
oligomannose-specific HIV-neutralizing antibodies bound the undecasaccharide
conjugates poorly. Possible reasons for this outcome are discussed
herein along with paths for improvement.
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Affiliation(s)
- Nino Trattnig
- Department of Chemistry , University of Natural Resources and Life Sciences , A-1190 Vienna , Austria
| | - Markus Blaukopf
- Department of Chemistry , University of Natural Resources and Life Sciences , A-1190 Vienna , Austria
| | | | | | - Paul Kosma
- Department of Chemistry , University of Natural Resources and Life Sciences , A-1190 Vienna , Austria
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17
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Haji-Ghassemi O, Müller-Loennies S, Brooks CL, MacKenzie CR, Caveney N, Van Petegem F, Brade L, Kosma P, Brade H, Evans SV. Subtle Changes in the Combining Site of the Chlamydiaceae-Specific mAb S25-23 Increase the Antibody-Carbohydrate Binding Affinity by an Order of Magnitude. Biochemistry 2019; 58:714-726. [PMID: 30571096 DOI: 10.1021/acs.biochem.8b00318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Murine antibodies S25-23, S25-26, and S25-5 derive from a common germ-line origin, and all bind the Chlamydiaceae family-specific epitope αKdo(2→8)αKdo(2→4)αKdo (where Kdo is 3-deoxy-α-d- manno-oct-2-ulosonic acid) with high affinity and specificity. These antibodies recognize the entire trisaccharide antigen in a linkage-dependent manner via a groove composed largely of germ-line residues. Despite sharing identical heavy and light chain genes, S25-23 binds the family-specific epitope with nanomolar affinity, which is an order of magnitude higher than that of S25-26, while S25-5 displays an affinity between those of S25-23 and S25-26. We determined the high-resolution crystal structures of S25-23 and S25-5 antigen binding fragments in complex with a pentasaccharide derived from the LPS of Chlamydia and measured the affinity of S25-5 for chlamydial LPS antigens using isothermal titration microcalorimetry. The 1.75 Å resolution structure of S25-23 shows how subtle conservative mutations Arg(L)-27E to lysine and Ser(H)-56 to threonine lead to an order of magnitude increase in affinity. Importantly, comparison between previous S25-26 structures and the 1.99 and 2.05 Å resolution liganded and unliganded structures of S25-5, respectively, shows how a Ser(L)-27E mutation results in an intermediate affinity due to the reduced enthalpic penalty associated with complex formation that would otherwise be required for arginine in this position. This strategy allows for subtle adjustments in the combining site via affinity maturation that have dramatic consequences for the affinity of an antibody for its antigen.
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Affiliation(s)
- Omid Haji-Ghassemi
- Department of Biochemistry and Microbiology , University of Victoria , P.O. Box 3055 STN CSC, Victoria , British Columbia , Canada V8P 3P6
| | - Sven Müller-Loennies
- Research Center Borstel , Leibniz Lung Center , Parkallee 22 , Borstel D-23845 , Germany
| | - Cory L Brooks
- Department of Chemistry , Fresno State University , 2555 East San Ramon Avenue, MS SB70 , Fresno , California 93740 , United States
| | - C Roger MacKenzie
- Human Health Therapeutics Portfolio , National Research Council Canada , 100 Sussex Drive , Ottawa , Ontario , Canada K1A 0R6
| | - Nathanael Caveney
- Department of Biochemistry and Microbiology , University of Victoria , P.O. Box 3055 STN CSC, Victoria , British Columbia , Canada V8P 3P6
| | - Filip Van Petegem
- Department of Chemistry , University of Natural Resources and Life Sciences , A-1190 Vienna , Austria
| | - Lore Brade
- Research Center Borstel , Leibniz Lung Center , Parkallee 22 , Borstel D-23845 , Germany
| | - Paul Kosma
- Department of Chemistry , University of Natural Resources and Life Sciences , A-1190 Vienna , Austria
| | - Helmut Brade
- Research Center Borstel , Leibniz Lung Center , Parkallee 22 , Borstel D-23845 , Germany
| | - Stephen V Evans
- Department of Biochemistry and Microbiology , University of Victoria , P.O. Box 3055 STN CSC, Victoria , British Columbia , Canada V8P 3P6
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18
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19
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Fong R, Kajihara K, Chen M, Hotzel I, Mariathasan S, Hazenbos WL, Lupardus PJ. Structural investigation of human S. aureus-targeting antibodies that bind wall teichoic acid. MAbs 2018; 10:979-991. [PMID: 30102105 PMCID: PMC6204806 DOI: 10.1080/19420862.2018.1501252] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a growing health threat worldwide. Efforts to identify novel antibodies that target S. aureus cell surface antigens are a promising direction in the development of antibiotics that can halt MRSA infection. We biochemically and structurally characterized three patient-derived MRSA-targeting antibodies that bind to wall teichoic acid (WTA), which is a polyanionic surface glycopolymer. In S. aureus, WTA exists in both α- and β-forms, based on the stereochemistry of attachment of a N-acetylglucosamine residue to the repeating phosphoribitol sugar unit. We identified a panel of antibodies cloned from human patients that specifically recognize the α or β form of WTA, and can bind with high affinity to pathogenic wild-type strains of S. aureus bacteria. To investigate how the β-WTA specific antibodies interact with their target epitope, we determined the X-ray crystal structures of the three β-WTA specific antibodies, 4462, 4497, and 6078 (Protein Data Bank IDs 6DWI, 6DWA, and 6DW2, respectively), bound to a synthetic WTA epitope. These structures reveal that all three of these antibodies, while utilizing distinct antibody complementarity-determining region sequences and conformations to interact with β-WTA, fulfill two recognition principles: binding to the β-GlcNAc pyranose core and triangulation of WTA phosphate residues with polar contacts. These studies reveal the molecular basis for targeting a unique S. aureus cell surface epitope and highlight the power of human patient-based antibody discovery techniques for finding novel pathogen-targeting therapeutics.
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Affiliation(s)
- Rina Fong
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Kimberly Kajihara
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Matthew Chen
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Isidro Hotzel
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Sanjeev Mariathasan
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Wouter L.W. Hazenbos
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Patrick J. Lupardus
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA,CONTACT Patrick J. Lupardus Department of Structural Biology, Genentech, South San Francisco, CA, USA
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20
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Soliman C, Walduck AK, Yuriev E, Richards JS, Cywes-Bentley C, Pier GB, Ramsland PA. Structural basis for antibody targeting of the broadly expressed microbial polysaccharide poly- N-acetylglucosamine. J Biol Chem 2018; 293:5079-5089. [PMID: 29449370 DOI: 10.1074/jbc.ra117.001170] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/08/2018] [Indexed: 01/19/2023] Open
Abstract
In response to the widespread emergence of antibiotic-resistant microbes, new therapeutic agents are required for many human pathogens. A non-mammalian polysaccharide, poly-N-acetyl-d-glucosamine (PNAG), is produced by bacteria, fungi, and protozoan parasites. Antibodies that bind to PNAG and its deacetylated form (dPNAG) exhibit promising in vitro and in vivo activities against many microbes. A human IgG1 mAb (F598) that binds both PNAG and dPNAG has opsonic and protective activities against multiple microbial pathogens and is undergoing preclinical and clinical assessments as a broad-spectrum antimicrobial therapy. Here, to understand how F598 targets PNAG, we determined crystal structures of the unliganded F598 antigen-binding fragment (Fab) and its complexes with N-acetyl-d-glucosamine (GlcNAc) and a PNAG oligosaccharide. We found that F598 recognizes PNAG through a large groove-shaped binding site that traverses the entire light- and heavy-chain interface and accommodates at least five GlcNAc residues. The Fab-GlcNAc complex revealed a deep binding pocket in which the monosaccharide and a core GlcNAc of the oligosaccharide were almost identically positioned, suggesting an anchored binding mechanism of PNAG by F598. The Fab used in our structural analyses retained binding to PNAG on the surface of an antibiotic-resistant, biofilm-forming strain of Staphylococcus aureus Additionally, a model of intact F598 binding to two pentasaccharide epitopes indicates that the Fab arms can span at least 40 GlcNAc residues on an extended PNAG chain. Our findings unravel the structural basis for F598 binding to PNAG on microbial surfaces and biofilms.
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Affiliation(s)
- Caroline Soliman
- From the School of Science, Royal Melbourne Institute of Technology (RMIT) University, Bundoora, Victoria 3083, Australia
| | - Anna K Walduck
- From the School of Science, Royal Melbourne Institute of Technology (RMIT) University, Bundoora, Victoria 3083, Australia
| | - Elizabeth Yuriev
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Jack S Richards
- Disease Elimination Program, Burnet Institute, Melbourne, Victoria 3004, Australia.,Victorian Infectious Diseases Service, Royal Melbourne Hospital, Parkville, Victoria 3052, Australia.,Department of Medicine, University of Melbourne, Parkville, Victoria 3052, Australia.,Department of Infectious Diseases, Central Clinical School, Alfred Hospital, Melbourne, Victoria 3004, Australia
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts 02115
| | - Gerald B Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts 02115
| | - Paul A Ramsland
- From the School of Science, Royal Melbourne Institute of Technology (RMIT) University, Bundoora, Victoria 3083, Australia, .,Disease Elimination Program, Burnet Institute, Melbourne, Victoria 3004, Australia.,Department of Immunology, Central Clinical School, Monash University, Victoria 3004, Melbourne, Australia, and.,Department of Surgery Austin Health, University of Melbourne, Heidelberg, Victoria 3084
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21
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Schumann B, Hahm HS, Parameswarappa SG, Reppe K, Wahlbrink A, Govindan S, Kaplonek P, Pirofski LA, Witzenrath M, Anish C, Pereira CL, Seeberger PH. A semisynthetic Streptococcus pneumoniae serotype 8 glycoconjugate vaccine. Sci Transl Med 2017; 9:9/380/eaaf5347. [PMID: 28275152 DOI: 10.1126/scitranslmed.aaf5347] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 05/19/2016] [Accepted: 02/06/2017] [Indexed: 01/09/2023]
Abstract
Glycoconjugate vaccines based on capsular polysaccharides (CPSs) of pathogenic bacteria such as Streptococcus pneumoniae successfully protect from disease but suffer from incomplete coverage, are troublesome to manufacture from isolated CPSs, and lack efficacy against certain serotypes. Defined, synthetic oligosaccharides are an attractive alternative to isolated CPSs but require the identification of immunogenic and protective oligosaccharide antigens. We describe a medicinal chemistry strategy based on a combination of automated glycan assembly (AGA), glycan microarray-based monoclonal antibody (mAb) reverse engineering, and immunological evaluation in vivo to uncover a protective glycan epitope (glycotope) for S. pneumoniae serotype 8 (ST8). All four tetrasaccharide frameshifts of ST8 CPS were prepared by AGA and used in glycan microarray experiments to identify the glycotopes recognized by antibodies against ST8. One tetrasaccharide frameshift that was preferentially recognized by a protective, CPS-directed mAb was conjugated to the carrier protein CRM197. Immunization of mice with this semisynthetic glycoconjugate followed by generation and characterization of a protective mAb identified protective and nonprotective glycotopes. Immunization of rabbits with semisynthetic ST8 glycoconjugates containing protective glycotopes induced an antibacterial immune response. Coformulation of ST8 glycoconjugates with the marketed 13-valent glycoconjugate vaccine Prevnar 13 yielded a potent 14-valent S. pneumoniae vaccine. Our strategy presents a facile approach to develop efficient semisynthetic glycoconjugate vaccines.
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Affiliation(s)
- Benjamin Schumann
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany.,Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Heung Sik Hahm
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany.,Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | | | - Katrin Reppe
- Division of Pulmonary Inflammation, Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Annette Wahlbrink
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany
| | - Subramanian Govindan
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany
| | - Paulina Kaplonek
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany.,Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Liise-Anne Pirofski
- Division of Infectious Diseases, Department of Medicine, Montefiore Medical Center and Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Martin Witzenrath
- Division of Pulmonary Inflammation, Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Chakkumkal Anish
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany
| | - Claney L Pereira
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany.
| | - Peter H Seeberger
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany. .,Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
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22
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Sterner E, Peach ML, Nicklaus MC, Gildersleeve JC. Therapeutic Antibodies to Ganglioside GD2 Evolved from Highly Selective Germline Antibodies. Cell Rep 2017; 20:1681-1691. [PMID: 28813678 PMCID: PMC5572838 DOI: 10.1016/j.celrep.2017.07.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 05/15/2017] [Accepted: 07/19/2017] [Indexed: 12/11/2022] Open
Abstract
Antibodies play a crucial role in host defense and are indispensable research tools, diagnostics, and therapeutics. Antibody generation involves binding of genomically encoded germline antibodies followed by somatic hypermutation and in vivo selection to obtain antibodies with high affinity and selectivity. Understanding this process is critical for developing monoclonal antibodies, designing effective vaccines, and understanding autoantibody formation. Prior studies have found that antibodies to haptens, peptides, and proteins evolve from polyspecific germline antibodies. The immunological evolution of antibodies to mammalian glycans has not been studied. Using glycan microarrays, protein microarrays, cell binding studies, and molecular modeling, we demonstrate that therapeutic antibodies to the tumor-associated ganglioside GD2 evolved from highly specific germline precursors. The results have important implications for developing vaccines and monoclonal antibodies that target carbohydrate antigens. In addition, they demonstrate an alternative pathway for antibody evolution within the immune system that is distinct from the polyspecific germline pathway.
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Affiliation(s)
- Eric Sterner
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Megan L Peach
- Basic Science Program, Chemical Biology Laboratory, Leidos Biomedical Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Marc C Nicklaus
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
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Polyspecificity of Anti-lipid A Antibodies and Its Relevance to the Development of Autoimmunity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 966:181-202. [PMID: 28887790 DOI: 10.1007/5584_2017_94] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The process of natural selection favours germ-line gene segments that encode CDRs that have the ability to recognize a range of structurally related antigens. This presents an immunological advantage to the host, as it can confer protection against a common pathogen and still cope with new or changing antigens. Cross-reactive and polyspecific antibodies also play a central role in autoimmune responses, and a link has been shown to exist between auto-reactive B cells and certain bacterial infections. Bacterial DNA, lipids, and carbohydrates have been implicated in the progression of autoimmune diseases such as systemic lupus erythematosus. As well, reports of anti-lipid A antibody polyspecificity towards single-stranded DNA together with the observed sequence homology amongst isolated auto- and anti-lipid A antibodies has prompted further study of this phenomenon. Though the lipid A epitope appears cryptic during Gram-negative bacterial infection, there have been several reported instances of lipid A-specific antibodies isolated from human sera, some of which have exhibited polyspecificity for single stranded DNA. In such cases, the breakdown of negative selection through polyspecificity can have the unfortunate consequence of autoimmune disease. This review summarizes current knowledge regarding such antibodies and emphasizes the features of S1-15, A6, and S55-5, anti-lipid A antibodies whose structures were recently determined by X-ray crystallography.
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Wolfram W, Sauerwein KMT, Binder CJ, Eibl-Musil N, Wolf HM, Fischer MB. Pneumococcal Polysaccharide Vaccination Elicits IgG Anti-A/B Blood Group Antibodies in Healthy Individuals and Patients with Type I Diabetes Mellitus. Front Immunol 2016; 7:493. [PMID: 27895641 PMCID: PMC5108245 DOI: 10.3389/fimmu.2016.00493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/25/2016] [Indexed: 12/20/2022] Open
Abstract
Hypothesis Blood group antibodies are natural antibodies that develop early in life in response to cross-reactive environmental antigens in the absence of antigen encounter. Even later in life structural similarities in saccharide composition between environmental antigens such as bacterial polysaccharides and blood group A/B antigens could lead to changes in serum levels, IgM/IgG isotype, and affinity maturation of blood group anti-A/B antibodies. We addressed the question whether immunization with pneumococcal polysaccharide (PnP) vaccine Pneumo 23 Vaccine “Pasteur Merieux” (Pn23) could have such an effect in patients with type I diabetes mellitus (DM I), an autoimmune disease where an aberrant immune response to microbial antigens likely plays a role. Methods Anti-PnP IgM and IgG responses were determined by ELISA, and the DiaMed-ID Micro Typing System was used to screen anti-A/B antibody titer before and after Pn23 immunization in 28 healthy individuals and 16 patients with DM I. In addition, surface plasmon resonance (SPR) technology using the Biacore® device and a synthetic blood group A/B trisaccharide as the antigen was applied to investigate IgM and IgG anti-A/B antibodies and to measure antibody binding dynamics. Results All healthy individuals and DM I patients responded with anti-PnP IgM and IgG antibody production 4–6 weeks after Pn23 immunization, while no increase in blood group anti-A/B antibody titer was observed when measured by the DiaMed-ID Micro Typing System. Interestingly, isotype-specific testing by SPR technology revealed an increase in blood group anti-A/B IgG, but not IgM, following Pn23 immunization in both patients and controls. No change in binding characteristics of blood group anti-A/B antibodies could be detected following Pn23 vaccination, supporting the assumption of an increase in IgG antibody titer with no or very little affinity maturation. Conclusion The study provides evidence for epitope sharing between pneumococcal polysaccharides and blood group ABO antigens, which leads to a booster of blood group anti-A/B antibodies of the IgG isotype after Pn23 immunization in healthy individuals. Manifest autoimmunity such as present in DM I patients has no additional effect on the cross-reactive antibody response against pneumococcal polysaccharides and blood group antigens.
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Affiliation(s)
- Wendelin Wolfram
- Clinic for Blood Group Serology and Transfusion Medicine, Medical University of Vienna , Vienna , Austria
| | | | - Christoph J Binder
- Department of Laboratory Medicine, Medical University of Vienna , Vienna , Austria
| | | | - Hermann M Wolf
- Immunology Outpatient Clinic, Vienna, Austria; Sigmund Freud Private University - Medical School, Vienna, Austria
| | - Michael B Fischer
- Clinic for Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria; Department for Health Science and Biomedicine, Danube University Krems, Krems, Austria
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Bryson S, Thomson CA, Risnes LF, Dasgupta S, Smith K, Schrader JW, Pai EF. Structures of Preferred Human IgV Genes-Based Protective Antibodies Identify How Conserved Residues Contact Diverse Antigens and Assign Source of Specificity to CDR3 Loop Variation. THE JOURNAL OF IMMUNOLOGY 2016; 196:4723-30. [PMID: 27183571 DOI: 10.4049/jimmunol.1402890] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 04/01/2016] [Indexed: 11/19/2022]
Abstract
The human Ab response to certain pathogens is oligoclonal, with preferred IgV genes being used more frequently than others. A pair of such preferred genes, IGVK3-11 and IGVH3-30, contributes to the generation of protective Abs directed against the 23F serotype of the pneumonococcal capsular polysaccharide of Streptococcus pneumoniae and against the AD-2S1 peptide of the gB membrane protein of human CMV. Structural analyses of Fab fragments of mAbs 023.102 and pn132p2C05 in complex with portions of the 23F polysaccharide revealed five germline-encoded residues in contact with the key component, l-rhamnose. In the case of the AD-2S1 peptide, the KE5 Fab fragment complex identified nine germline-encoded contact residues. Two of these germline-encoded residues, Arg91L and Trp94L, contact both the l-rhamnose and the AD-2S1 peptide. Comparison of the respective paratopes that bind to carbohydrate and protein reveals that stochastic diversity in both CDR3 loops alone almost exclusively accounts for their divergent specificity. Combined evolutionary pressure by human CMV and the 23F serotype of S. pneumoniae acted on the IGVK3-11 and IGVH3-30 genes as demonstrated by the multiple germline-encoded amino acids that contact both l-rhamnose and AD-2S1 peptide.
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Affiliation(s)
- Steve Bryson
- Princess Margaret Cancer Centre, Toronto, Ontario M5G 1L7, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Christy A Thomson
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Louise F Risnes
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Somnath Dasgupta
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Kenneth Smith
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - John W Schrader
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Emil F Pai
- Princess Margaret Cancer Centre, Toronto, Ontario M5G 1L7, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5S 1A8, Canada; and Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
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Multivalent display of minimal Clostridium difficile glycan epitopes mimics antigenic properties of larger glycans. Nat Commun 2016; 7:11224. [PMID: 27091615 PMCID: PMC4838876 DOI: 10.1038/ncomms11224] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/26/2016] [Indexed: 12/31/2022] Open
Abstract
Synthetic cell-surface glycans are promising vaccine candidates against Clostridium difficile. The complexity of large, highly antigenic and immunogenic glycans is a synthetic challenge. Less complex antigens providing similar immune responses are desirable for vaccine development. Based on molecular-level glycan–antibody interaction analyses, we here demonstrate that the C. difficile surface polysaccharide-I (PS-I) can be resembled by multivalent display of minimal disaccharide epitopes on a synthetic scaffold that does not participate in binding. We show that antibody avidity as a measure of antigenicity increases by about five orders of magnitude when disaccharides are compared with constructs containing five disaccharides. The synthetic, pentavalent vaccine candidate containing a peptide T-cell epitope elicits weak but highly specific antibody responses to larger PS-I glycans in mice. This study highlights the potential of multivalently displaying small oligosaccharides to achieve antigenicity characteristic of larger glycans. The approach may result in more cost-efficient carbohydrate vaccines with reduced synthetic effort. Immunologically-active glycans are promising vaccine candidates but can be difficult to synthesize. Here, the authors show that pentavalent display of a minimal disaccharde epitope on a chemical scaffold can mimic a native C. difficile glycan antigen, representing a simple approach to synthetic vaccine production.
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27
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Haji-Ghassemi O, Müller-Loennies S, Rodriguez T, Brade L, Grimmecke HD, Brade H, Evans SV. The Combining Sites of Anti-lipid A Antibodies Reveal a Widely Utilized Motif Specific for Negatively Charged Groups. J Biol Chem 2016; 291:10104-18. [PMID: 26933033 DOI: 10.1074/jbc.m115.712448] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Indexed: 01/29/2023] Open
Abstract
Lipopolysaccharide dispersed in the blood by Gram-negative bacteria can be a potent inducer of septic shock. One research focus has been based on antibody sequestration of lipid A (the endotoxic principle of LPS); however, none have been successfully developed into a clinical treatment. Comparison of a panel of anti-lipid A antibodies reveals highly specific antibodies produced through distinct germ line precursors. The structures of antigen-binding fragments for two homologous mAbs specific for lipid A, S55-3 and S55-5, have been determined both in complex with lipid A disaccharide backbone and unliganded. These high resolution structures reveal a conserved positively charged pocket formed within the complementarity determining region H2 loops that binds the terminal phosphates of lipid A. Significantly, this motif occurs in unrelated antibodies where it mediates binding to negatively charged moieties through a range of epitopes, including phosphorylated peptides used in diagnostics and therapeutics. S55-3 and S55-5 have combining sites distinct from anti-lipid A antibodies previously described (as a result of their separate germ line origin), which are nevertheless complementary both in shape and charge to the antigen. S55-3 and S55-5 display similar avidity toward lipid A despite possessing a number of different amino acid residues in their combining sites. Binding of lipid A occurs independent of the acyl chains, although the GlcN-O6 attachment point for the core oligosaccharide is buried in the combining site, which explains their inability to recognize LPS. Despite their lack of therapeutic potential, the observed motif may have significant immunological implications as a tool for engineering recombinant antibodies.
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Affiliation(s)
- Omid Haji-Ghassemi
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada and
| | - Sven Müller-Loennies
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany
| | - Teresa Rodriguez
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada and
| | - Lore Brade
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany
| | - Hans-Dieter Grimmecke
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany
| | - Helmut Brade
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany
| | - Stephen V Evans
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada and
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Haji-Ghassemi O, Müller-Loennies S, Rodriguez T, Brade L, Kosma P, Brade H, Evans SV. Structural Basis for Antibody Recognition of Lipid A: INSIGHTS TO POLYSPECIFICITY TOWARD SINGLE-STRANDED DNA. J Biol Chem 2015; 290:19629-40. [PMID: 26085093 DOI: 10.1074/jbc.m115.657874] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Indexed: 01/14/2023] Open
Abstract
Septic shock is a leading cause of death, and it results from an inflammatory cascade triggered by the presence of microbial products in the blood. Certain LPS from Gram-negative bacteria are very potent inducers and are responsible for a high percentage of septic shock cases. Despite decades of research, mAbs specific for lipid A (the endotoxic principle of LPS) have not been successfully developed into a clinical treatment for sepsis. To understand the molecular basis for the observed inability to translate in vitro specificity for lipid A into clinical potential, the structures of antigen-binding fragments of mAbs S1-15 and A6 have been determined both in complex with lipid A carbohydrate backbone and in the unliganded form. The two antibodies have separate germ line origins that generate two markedly different combining-site pockets that are complementary both in shape and charge to the antigen. mAb A6 binds lipid A through both variable light and heavy chain residues, whereas S1-15 utilizes exclusively the variable heavy chain. Both antibodies bind lipid A such that the GlcN-O6 attachment point for the core oligosaccharide is buried in the combining site, which explains the lack of LPS recognition. Longstanding reports of polyspecificity of anti-lipid A antibodies toward single-stranded DNA combined with observed homology of S1-15 and A6 and the reports of several single-stranded DNA-specific mAbs prompted the determination of the structure of S1-15 in complex with single-stranded DNA fragments, which may provide clues about the genesis of autoimmune diseases such as systemic lupus erythematosus, thyroiditis, and rheumatic autoimmune diseases.
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Affiliation(s)
- Omid Haji-Ghassemi
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada
| | - Sven Müller-Loennies
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany, and
| | - Teresa Rodriguez
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada
| | - Lore Brade
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany, and
| | - Paul Kosma
- the Department of Chemistry, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Helmut Brade
- the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany, and
| | - Stephen V Evans
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada,
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29
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Haji-Ghassemi O, Blackler RJ, Martin Young N, Evans SV. Antibody recognition of carbohydrate epitopes†. Glycobiology 2015; 25:920-52. [PMID: 26033938 DOI: 10.1093/glycob/cwv037] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/24/2015] [Indexed: 12/14/2022] Open
Abstract
Carbohydrate antigens are valuable as components of vaccines for bacterial infectious agents and human immunodeficiency virus (HIV), and for generating immunotherapeutics against cancer. The crystal structures of anti-carbohydrate antibodies in complex with antigen reveal the key features of antigen recognition and provide information that can guide the design of vaccines, particularly synthetic ones. This review summarizes structural features of anti-carbohydrate antibodies to over 20 antigens, based on six categories of glyco-antigen: (i) the glycan shield of HIV glycoproteins; (ii) tumor epitopes; (iii) glycolipids and blood group A antigen; (iv) internal epitopes of bacterial lipopolysaccharides; (v) terminal epitopes on polysaccharides and oligosaccharides, including a group of antibodies to Kdo-containing Chlamydia epitopes; and (vi) linear homopolysaccharides.
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Affiliation(s)
- Omid Haji-Ghassemi
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8P 3P6
| | - Ryan J Blackler
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8P 3P6
| | - N Martin Young
- Human Health Therapeutics, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada K1A 0R6
| | - Stephen V Evans
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8P 3P6
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30
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Fischer MB, Wolfram W, Binder CJ, Böhmig GA, Wahrmann M, Eibl MM, Wolf HM. Surface Plasmon Resonance Analysis Shows an IgG-Isotype-Specific Defect in ABO Blood Group Antibody Formation in Patients with Common Variable Immunodeficiency. Front Immunol 2015; 6:211. [PMID: 25999949 PMCID: PMC4422094 DOI: 10.3389/fimmu.2015.00211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/17/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Common variable immunodeficiency (CVID) is the most common clinically severe primary immunodeficiency and comprises a heterogeneous group of patients with recurrent severe bacterial infections due to the failure to produce IgG antibodies after exposure to infectious agents and immunization. Diagnostic recommendations for antibody failure include assessment of isoagglutinins. We have readdressed this four decades old but still accepted recommendation with up to date methodology. METHODS Anti-A/B IgM- and IgG-antibodies were measured by Diamed-ID Micro Typing, surface plasmon resonance (SPR) using the Biacore(®) device and flow cytometry. RESULTS When Diamed-ID Micro Typing was used, CVID patients (n = 34) showed IgG- and IgM-isoagglutinins that were comparable to healthy volunteers (n = 28), while all XLA patients (n = 8) had none. Anti-A/B IgM-antibodies were present in more than 2/3 of the CVID patients and showed binding kinetics comparable to anti-A/B IgM-antibodies from healthy individuals. A correlation could be found in CVID patients between levels of anti-A/B IgM-antibodies and levels of serum IgM and PnP-IgM-antibodies. In contrast in CVID patients as a group ABO antibodies were significantly decreased when assessed by SPR, which correlated with levels of switched memory, non-switched memory and naïve B cells, but all CVID patients had low/undetectable anti-A/B IgG-antibodies. CONCLUSION These results indicate that conventional isoagglutinin assessment and assessment of anti-A/B IgM antibodies are not suited for the diagnosis of impaired antibody production in CVID. Examination of anti-A/B IgG antibodies by SPR provides a useful method for the diagnosis of IgG antibody failure in all CVID patients studied, thus indicating an important additional rationale to start immunoglobulin replacement therapy early in these patients, before post-infectious sequelae develop.
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Affiliation(s)
- Michael B. Fischer
- Department of Transfusion Medicine, Medical University of Vienna, Vienna, Austria
- Center of Biomedical Technology, Danube University Krems, Krems an der Donau, Austria
| | - Wendelin Wolfram
- Department of Transfusion Medicine, Medical University of Vienna, Vienna, Austria
| | - Christoph J. Binder
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Georg A. Böhmig
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Markus Wahrmann
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria
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31
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Hadzhieva M, Vassilev TL, Roumenina LT, Bayry J, Kaveri SV, Lacroix-Desmazes S, Dimitrov JD. Mechanism and Functional Implications of the Heme-Induced Binding Promiscuity of IgE. Biochemistry 2015; 54:2061-72. [DOI: 10.1021/bi501507m] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maya Hadzhieva
- Institute
of Microbiology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | | | - Lubka T. Roumenina
- Sorbonne Universités, UPMC Univ Paris 06,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
- INSERM, UMR_S 1138, Centre
de Recherche des Cordeliers, F-75006 Paris, France
- Université Paris Descartes, Sorbonne Paris Cité,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
| | - Jagadeesh Bayry
- Sorbonne Universités, UPMC Univ Paris 06,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
- INSERM, UMR_S 1138, Centre
de Recherche des Cordeliers, F-75006 Paris, France
- Université Paris Descartes, Sorbonne Paris Cité,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
| | - Srinivas V. Kaveri
- Sorbonne Universités, UPMC Univ Paris 06,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
- INSERM, UMR_S 1138, Centre
de Recherche des Cordeliers, F-75006 Paris, France
- Université Paris Descartes, Sorbonne Paris Cité,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
| | - Sébastien Lacroix-Desmazes
- Sorbonne Universités, UPMC Univ Paris 06,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
- INSERM, UMR_S 1138, Centre
de Recherche des Cordeliers, F-75006 Paris, France
- Université Paris Descartes, Sorbonne Paris Cité,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
| | - Jordan D. Dimitrov
- Sorbonne Universités, UPMC Univ Paris 06,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
- INSERM, UMR_S 1138, Centre
de Recherche des Cordeliers, F-75006 Paris, France
- Université Paris Descartes, Sorbonne Paris Cité,
UMR_S 1138, Centre de Recherche des Cordeliers, F-75006 Paris, France
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32
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Lecerf M, Scheel T, Pashov AD, Jarossay A, Ohayon D, Planchais C, Mesnage S, Berek C, Kaveri SV, Lacroix-Desmazes S, Dimitrov JD. Prevalence and gene characteristics of antibodies with cofactor-induced HIV-1 specificity. J Biol Chem 2015; 290:5203-5213. [PMID: 25564611 DOI: 10.1074/jbc.m114.618124] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The healthy immune repertoire contains a fraction of antibodies that bind to various biologically relevant cofactors, including heme. Interaction of heme with some antibodies results in induction of new antigen binding specificities and acquisition of binding polyreactivity. In vivo, extracellular heme is released as a result of hemolysis or tissue damage; hence the post-translational acquisition of novel antigen specificities might play an important role in the diversification of the immunoglobulin repertoire and host defense. Here, we demonstrate that seronegative immune repertoires contain antibodies that gain reactivity to HIV-1 gp120 upon exposure to heme. Furthermore, a panel of human recombinant antibodies was cloned from different B cell subpopulations, and the prevalence of antibodies with cofactor-induced specificity for gp120 was determined. Our data reveal that upon exposure to heme, ∼24% of antibodies acquired binding specificity for divergent strains of HIV-1 gp120. Sequence analyses reveal that heme-sensitive antibodies do not differ in their repertoire of variable region genes and in most of the molecular features of their antigen-binding sites from antibodies that do not change their antigen binding specificity. However, antibodies with cofactor-induced gp120 specificity possess significantly lower numbers of somatic mutations in their variable region genes. This study contributes to the understanding of the significance of cofactor-binding antibodies in immunoglobulin repertoires and of the influence that the tissue microenvironment might have in shaping adaptive immune responses.
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Affiliation(s)
- Maxime Lecerf
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France
| | - Tobias Scheel
- the Deutsches Rheuma-Forschungszentrum, Institut der Leibniz-Gemeinschaft, 10117 Berlin, Germany
| | - Anastas D Pashov
- the Institute of Microbiology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria, and
| | - Annaelle Jarossay
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France
| | - Delphine Ohayon
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France
| | - Cyril Planchais
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France
| | - Stephane Mesnage
- the Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom
| | - Claudia Berek
- the Deutsches Rheuma-Forschungszentrum, Institut der Leibniz-Gemeinschaft, 10117 Berlin, Germany
| | - Srinivas V Kaveri
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France
| | - Sébastien Lacroix-Desmazes
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France
| | - Jordan D Dimitrov
- From the Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S 1138, F-75006 Paris, France,; the Université Paris Descartes, UMR S 1138, F-75006 Paris, France,; INSERM U1138, F-75006 Paris, France,.
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Pokorny B, Kosma P. Synthesis of chlamydia lipopolysaccharide haptens through the use of α-specific 3-iodo-Kdo fluoride glycosyl donors. Chemistry 2015; 21:305-13. [PMID: 25354167 PMCID: PMC4768360 DOI: 10.1002/chem.201405424] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Indexed: 12/20/2022]
Abstract
A scalable approach towards high-yielding and (stereo)selective glycosyl donors of the 2-ulosonic acid Kdo (3-deoxy-D-manno-oct-2-ulosonic acid) is a fundamental requirement for the development of vaccines against Gram-negative bacteria. Herein, we disclose a short synthetic route to 3-iodo Kdo fluoride donors from Kdo glycal esters that enable efficient α-specific glycosylations and significantly suppress the elimination side reaction. The potency of these donors is demonstrated in a straightforward, six-step synthesis of a branched Chlamydia-related Kdo-trisaccharide ligand without the need for protecting groups at the Kdo glycosyl acceptor. The approach was further extended to include sequential iteration of the basic concept to produce the linear Chlamydia-specific α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo trisaccharide in a good overall yield.
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Affiliation(s)
- Barbara Pokorny
- Department of Chemistry, University of Natural Resources and Life Sciences-Vienna, Muthgasse 18, A-1190 Vienna, Austria
| | - Paul Kosma
- Department of Chemistry, University of Natural Resources and Life Sciences-Vienna, Muthgasse 18, A-1190 Vienna, Austria
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34
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Reinhardt A, Yang Y, Claus H, Pereira C, Cox A, Vogel U, Anish C, Seeberger P. Antigenic Potential of a Highly Conserved Neisseria meningitidis Lipopolysaccharide Inner Core Structure Defined by Chemical Synthesis. ACTA ACUST UNITED AC 2015; 22:38-49. [DOI: 10.1016/j.chembiol.2014.11.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/11/2014] [Accepted: 11/16/2014] [Indexed: 02/08/2023]
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35
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Stanfield RL, De Castro C, Marzaioli AM, Wilson IA, Pantophlet R. Crystal structure of the HIV neutralizing antibody 2G12 in complex with a bacterial oligosaccharide analog of mammalian oligomannose. Glycobiology 2014; 25:412-9. [PMID: 25380763 DOI: 10.1093/glycob/cwu123] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) is a major public health threat that continues to infect millions of people worldwide each year. A prophylactic vaccine remains the most cost-effective way of globally reducing and eliminating the spread of the virus. The HIV envelope spike, which is the target of many vaccine design efforts, is densely mantled with carbohydrate and several potent broadly neutralizing antibodies to HIV-1 recognize carbohydrate on the envelope spike as a major part of their epitope. However, immunizing with recombinant forms of the envelope glycoprotein does not typically elicit anti-carbohydrate antibodies. Thus, studies of alternative antigens that may serve as a starting point for carbohydrate-based immunogens are of interest. Here, we present the crystal structure of one such anti-carbohydrate HIV neutralizing antibody (2G12) in complex with the carbohydrate backbone of the lipooligosaccharide from Rhizobium radiobacter strain Rv3, which exhibits a chemical structure that naturally mimics the core high-mannose carbohydrate epitope of 2G12 on HIV-1 gp120. The structure described here provides molecular evidence of the structural homology between the Rv3 oligosaccharide and highly abundant carbohydrates on the surface of HIV-1 and raises the potential for the design of novel glycoconjugates that may find utility in efforts to develop immunogens for eliciting carbohydrate-specific neutralizing antibodies to HIV.
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Affiliation(s)
- Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, Scripps CHAVI-ID, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
| | - Cristina De Castro
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario Monte Sant'Angelo, 80126 Napoli, Italy
| | - Alberto M Marzaioli
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario Monte Sant'Angelo, 80126 Napoli, Italy
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, Scripps CHAVI-ID, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
| | - Ralph Pantophlet
- Faculty of Health Sciences and Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
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36
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Finton KAK, Friend D, Jaffe J, Gewe M, Holmes MA, Larman HB, Stuart A, Larimore K, Greenberg PD, Elledge SJ, Stamatatos L, Strong RK. Ontogeny of recognition specificity and functionality for the broadly neutralizing anti-HIV antibody 4E10. PLoS Pathog 2014; 10:e1004403. [PMID: 25254371 PMCID: PMC4177983 DOI: 10.1371/journal.ppat.1004403] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 08/16/2014] [Indexed: 01/07/2023] Open
Abstract
The process of antibody ontogeny typically improves affinity, on-rate, and thermostability, narrows polyspecificity, and rigidifies the combining site to the conformer optimal for binding from the broader ensemble accessible to the precursor. However, many broadly-neutralizing anti-HIV antibodies incorporate unusual structural elements and recognition specificities or properties that often lead to autoreactivity. The ontogeny of 4E10, an autoreactive antibody with unexpected combining site flexibility, was delineated through structural and biophysical comparisons of the mature antibody with multiple potential precursors. 4E10 gained affinity primarily by off-rate enhancement through a small number of mutations to a highly conserved recognition surface. Controverting the conventional paradigm, the combining site gained flexibility and autoreactivity during ontogeny, while losing thermostability, though polyspecificity was unaffected. Details of the recognition mechanism, including inferred global effects due to 4E10 binding, suggest that neutralization by 4E10 may involve mechanisms beyond simply binding, also requiring the ability of the antibody to induce conformational changes distant from its binding site. 4E10 is, therefore, unlikely to be re-elicited by conventional vaccination strategies.
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Affiliation(s)
- Kathryn A. K. Finton
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Della Friend
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - James Jaffe
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Mesfin Gewe
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Margaret A. Holmes
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - H. Benjamin Larman
- Department of Genetics, Harvard University Medical School, and Division of Genetics, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Andrew Stuart
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Kevin Larimore
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Philip D. Greenberg
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Program in Immunology, Cancer Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Stephen J. Elledge
- Department of Genetics, Harvard University Medical School, and Division of Genetics, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Leonidas Stamatatos
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Roland K. Strong
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
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Saha S, Pashov A, Siegel ER, Murali R, Kieber-Emmons T. Defining the recognition elements of Lewis Y-reactive antibodies. PLoS One 2014; 9:e104208. [PMID: 25117628 PMCID: PMC4130537 DOI: 10.1371/journal.pone.0104208] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 07/11/2014] [Indexed: 11/23/2022] Open
Abstract
Antibody response to carbohydrate antigens is often independent of T cells and the process of affinity/specificity improvement is considered strictly dependent on the germinal centers. Antibodies induced during a T cell-independent type 2 (TI-2) response are less variable and less functionally versatile than those induced with T cell help. The antigen specificity consequences of accumulation of somatic mutations in antibodies during TI-2 responses of Marginal Zone (MZ) B cells is a fact that still needs explanation. Germline genes that define carbohydrate-reactive antibodies are known to sculpt antibody-combining sites containing innate, key side-chain contacts that define the antigen recognition step. However, substitutions associated with MZ B cell derived antibodies might affect the mobility and polyspecificity of the antibody. To examine this hypothesis, we analyzed antibodies reactive with the neolactoseries antigen Lewis Y (LeY) to define the residue subset required for the reactive repertoire for the LeY antigen. Our molecular simulation studies of crystallographically determined and modeled antibody-LeY complexes suggests that the heavy-chain germline gene VH7183.a13.20 and the light-chain Vκ cr1 germline gene are sufficient to account for the recognition of the trisaccharide-H determinant Types 1–4, while the specificity for LeY is driven by the CDR3 backbone conformation of the heavy chain and not the side chain interactions. These results confirm that these monoclonals use germline-encoded amino acids to recognize simple carbohydrate determinants like trisaccharide-H but relies on somatic mutations in the periphery of the combining site to modify affinity for LeY through electrostatic interactions that leads to their optimized binding. These observations bring further attention to the role of mutations in T-cell independent antibodies to distinguish self from non-self carbohydrate antigens.
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Affiliation(s)
- Somdutta Saha
- Bioinformatics Graduate Program, University of Arkansas at Little Rock/University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Anastas Pashov
- Stephan Angelov Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Eric R. Siegel
- Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Ramachandran Murali
- Department of Biological Sciences, Research Division of Immunology, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Thomas Kieber-Emmons
- Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
- * E-mail:
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38
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Pokorny B, Müller-Loennies S, Kosma P. Synthesis of α-d-glucosyl substituted methyl glycosides of 3-deoxy-α-d-manno- and d-glycero-α-d-talo-oct-2-ulosonic acid (Kdo/Ko) corresponding to inner core fragments of Acinetobacter lipopolysaccharide. Carbohydr Res 2014; 391:66-81. [PMID: 24785390 PMCID: PMC4019464 DOI: 10.1016/j.carres.2014.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 02/26/2014] [Accepted: 03/05/2014] [Indexed: 11/18/2022]
Abstract
Synthesis of Acinetobacter LPS fragments with orthogonal protecting pattern. First synthesis of Ko-glycosides substituted at position 5. α-Selective glucosylation using benzylidene trifluoroacetimidate donor. Regioselective phosphorylation at C-6 of a glucosyl substituent.
The α-d-glucopyranosyl-(1→5)-substituted methyl glycosides of 3-deoxy-α-d-manno-oct-2-ulosonic acid (Kdo), 3-deoxy-α-d-lyxo-hept-2-ulosonic acid (Kdh), and d-glycero-α-d-talo-oct-2-ulosonic acid (Ko) were prepared using orthogonally protected glycosyl acceptor derivatives via glycosylation with a torsionally disarmed 4,6-O-benzylidene protected trifluoroacetimidate glucosyl donor followed by global deprotection. The related 6-O-phosphoryl-α-d-glucopyranosyl-(1→5)-substituted Kdo and Kdh derivatives were derived from a benzylidene-protected glucosyl intermediate using phosphoramidite and phosphoryl chloride-based phosphorylation steps, respectively. The deprotected disaccharides serve as ligands to study lectin binding of Acinetobacter lipopolysaccharide core oligosaccharides.
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Affiliation(s)
- Barbara Pokorny
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | | | - Paul Kosma
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria.
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Khan T, Salunke DM. Adjustable locks and flexible keys: plasticity of epitope-paratope interactions in germline antibodies. THE JOURNAL OF IMMUNOLOGY 2014; 192:5398-405. [PMID: 24790145 DOI: 10.4049/jimmunol.1302143] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ag recognition by independent primary Abs against a small flexible Ag with overlapping epitopes was analyzed to address the determinants of Ag specificity during the initial encounter. Crystal structures of two distinct dodecapeptide Ags, GDPRPSYISHLL and PPYPAWHAPGNI, in complex with the germline mAb 36-65 were determined and compared with the structures of the same Ags bound to another independent germline mAb, BBE6.12H3. For each peptide Ag, the two germline mAbs recognized overlapping epitopes, but in different topologies. The peptide structures differed, and the two paratopes attained discrete conformations, leading to different surface topologies, in a mode that can be described as adjustable locks and flexible keys. This is in contrast to mature mAbs, in which conformational convergence of different paratopes while binding to a common epitope in a similar conformation has been reported. These results suggest that the primary immune receptor repertoire is highly versatile as compared with its mature counterpart. Germline and mature mAbs adopt distinct mechanisms for recognizing a flexible epitope. Whereas conservation of conformational repertoire is a key characteristic of mature mAbs achieved through affinity maturation, the germline mAbs, at the initial stages of Ag encounter, maintain substantial plasticity, accommodating a broad specificity repertoire.
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Affiliation(s)
- Tarique Khan
- National Institute of Immunology, New Delhi 110067, India; and
| | - Dinakar M Salunke
- National Institute of Immunology, New Delhi 110067, India; and Regional Centre for Biotechnology, Gurgaon 122016, India
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40
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Thermodynamic stability contributes to immunoglobulin specificity. Trends Biochem Sci 2014; 39:221-6. [PMID: 24685657 DOI: 10.1016/j.tibs.2014.02.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/27/2014] [Accepted: 02/28/2014] [Indexed: 01/16/2023]
Abstract
Antigen-binding specificity of immunoglobulins is important for their function in immune defense. However, immune repertoires contain a considerable fraction of immunoglobulins with promiscuous binding behavior, the physicochemical basis of which is not well understood. Evolution of immunoglobulin specificity occurs through iterative processes of mutation and selection, referred to as affinity maturation. Recent studies reveal that some somatic mutations could compromise the thermodynamic stability of the variable regions of immunoglobulins. By integrating this observation with the wealth of data on the evolution of novel enzyme activities, we propose that antibody specificity is linked to the thermodynamic stability of the antigen-binding regions, which provides a quantitative distinction between highly specific and promiscuous antibodies.
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41
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Haji-Ghassemi O, Müller-Loennies S, Saldova R, Muniyappa M, Brade L, Rudd PM, Harvey DJ, Kosma P, Brade H, Evans SV. Groove-type recognition of chlamydiaceae-specific lipopolysaccharide antigen by a family of antibodies possessing an unusual variable heavy chain N-linked glycan. J Biol Chem 2014; 289:16644-61. [PMID: 24682362 DOI: 10.1074/jbc.m113.528224] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The structure of the antigen binding fragment of mAb S25-26, determined to 1.95 Å resolution in complex with the Chlamydiaceae family-specific trisaccharide antigen Kdo(2→8)Kdo(2→4)Kdo (Kdo = 3-deoxy-α-d-manno-oct-2-ulopyranosonic acid), displays a germ-line-coded paratope that differs significantly from previously characterized Chlamydiaceae-specific mAbs despite being raised against the identical immunogen. Unlike the terminal Kdo recognition pocket that promotes cross-reactivity in S25-2-type antibodies, S25-26 and the closely related S25-23 utilize a groove composed of germ-line residues to recognize the entire trisaccharide antigen and so confer strict specificity. Interest in S25-23 was sparked by its rare high μm affinity and strict specificity for the family-specific trisaccharide antigen; however, only the related antibody S25-26 proved amenable to crystallization. The structures of three unliganded forms of S25-26 have a labile complementary-determining region H3 adjacent to significant glycosylation of the variable heavy chain on asparagine 85 in Framework Region 3. Analysis of the glycan reveals a heterogeneous mixture with a common root structure that contains an unusually high number of terminal αGal-Gal moieties. One of the few reported structures of glycosylated mAbs containing these epitopes is the therapeutic antibody Cetuximab; however, unlike Cetuximab, one of the unliganded structures in S25-26 shows significant order in the glycan with appropriate electron density for nine residues. The elucidation of the three-dimensional structure of an αGal-containing N-linked glycan on a mAb variable heavy chain has potential clinical interest, as it has been implicated in allergic response in patients receiving therapeutic antibodies.
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Affiliation(s)
- Omid Haji-Ghassemi
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada
| | - Sven Müller-Loennies
- Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany,
| | - Radka Saldova
- GlycoScience Group, the National Institute for Bioprocessing Research and Training (NIBRT), Mount Merrion, Blackrock, Dublin 4, Ireland
| | - Mohankumar Muniyappa
- GlycoScience Group, the National Institute for Bioprocessing Research and Training (NIBRT), Mount Merrion, Blackrock, Dublin 4, Ireland
| | - Lore Brade
- Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany
| | - Pauline M Rudd
- GlycoScience Group, the National Institute for Bioprocessing Research and Training (NIBRT), Mount Merrion, Blackrock, Dublin 4, Ireland
| | - David J Harvey
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Paul Kosma
- University of Natural Resources and Life Sciences, Vienna, Austria, and
| | - Helmut Brade
- Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel D-23845, Germany
| | - Stephen V Evans
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 3P6, Canada,
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42
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Parker MJ, Gomery K, Richard G, MacKenzie CR, Cox AD, Richards JC, Evans SV. Structural basis for selective cross-reactivity in a bactericidal antibody against inner core lipooligosaccharide from Neisseria meningitidis†,‡. Glycobiology 2014; 24:442-9. [DOI: 10.1093/glycob/cwu009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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43
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Provenzano D, Kovác P, Wade WF. The ABCs (Antibody, B Cells, and Carbohydrate Epitopes) of Cholera Immunity: Considerations for an Improved Vaccine. Microbiol Immunol 2013; 50:899-927. [PMID: 17179659 DOI: 10.1111/j.1348-0421.2006.tb03866.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cholera, a diarrheal disease, is known for explosive epidemics that can quickly kill thousands. Endemic cholera is a seasonal torment that also has a significant mortality. Not all nations with extensive rural communities can achieve the required infrastructure or behavioral changes to prevent epidemic or endemic cholera. For some communities, a single-dose cholera vaccine that protects those at risk is the most efficacious means to reduce morbidity and mortality. It is clear that our understanding of what a protective cholera immune response is has not progressed at the rate our understanding of the pathogenesis and molecular biology of cholera infection has. This review addresses V. cholerae lipopolysaccharide (LPS)-based immunogens because LPS is the only immunogen proven to induce protective antibody in humans. We discuss the role of anti-LPS antibodies in protection from cholera, the importance and the potential role of B cell subsets in protection that is based on their anatomical location and the intrinsic antigen-receptor specificity of various subsets is introduced.
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Affiliation(s)
- Daniele Provenzano
- Department of Biological Sciences, University of Texas-Brownsville, Brownsville, TX 78520, USA
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44
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Dimitrov JD, Planchais C, Roumenina LT, Vassilev TL, Kaveri SV, Lacroix-Desmazes S. Antibody polyreactivity in health and disease: statu variabilis. THE JOURNAL OF IMMUNOLOGY 2013; 191:993-9. [PMID: 23873158 DOI: 10.4049/jimmunol.1300880] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
An Ab molecule or a BCR that is able to bind multiple structurally unrelated Ags is defined as polyreactive. Polyreactive Abs and BCRs constitute an important part of immune repertoires under physiological conditions and may play essential roles in immune defense and in the maintenance of immune homeostasis. In this review, we integrate and discuss different findings that reveal the indispensable role of Ag-binding polyreactivity in the immune system. First, we describe the functional and molecular characteristics of polyreactive Abs. The following part of the review concentrates on the biological roles attributed to polyreactive Abs and to polyreactive BCRs. Finally, we discuss recent studies that link Ig polyreactivity with distinct pathological conditions.
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Affiliation(s)
- Jordan D Dimitrov
- INSERM, Unité 872, Centre de Recherche des Cordeliers, 75006 Paris, France.
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45
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Tapryal S, Gaur V, Kaur KJ, Salunke DM. Structural evaluation of a mimicry-recognizing paratope: plasticity in antigen-antibody interactions manifests in molecular mimicry. THE JOURNAL OF IMMUNOLOGY 2013; 191:456-63. [PMID: 23733869 DOI: 10.4049/jimmunol.1203260] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Molecular mimicry manifests antagonistically with respect to the specificity of immune recognition. However, it often occurs because different Ags share surface topologies in terms of shape or chemical nature. It also occurs when a flexible paratope accommodates dissimilar Ags by adjusting structural features according to the antigenic epitopes or differential positioning in the Ag combining site. Toward deciphering the structural basis of molecular mimicry, mAb 2D10 was isolated from a maturing immune response elicited against methyl α-d-mannopyranoside and also bound equivalently to a dodecapeptide. The physicochemical evidence of this carbohydrate-peptide mimicry in the case of mAb 2D10 had been established earlier. These studies had strongly suggested direct involvement of a flexible paratope in the observed mimicry. Surprisingly, comparison of the Ag-free structure of single-chain variable fragment 2D10 with those bound to sugar and peptide Ags revealed a conformationally invariant state of the Ab while binding to chemically and structurally disparate Ags. This equivalent binding of the two dissimilar Ags was through mutually independent interactions, demonstrating functional equivalence in the absence of structural correlation. Thus, existence of a multispecific, mature Ab in the secondary immune response was evident, as was the plasticity in the interactions while accommodating topologically diverse Ags. Although our data highlight the structural basis of receptor multispecificity, they also illustrate mechanisms adopted by the immune system to neutralize the escape mutants generated during pathogenic insult.
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Affiliation(s)
- Suman Tapryal
- National Institute of Immunology, New Delhi 110067, India
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46
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Brooks CL, Wimmer K, Kosma P, Müller-Loennies S, Brade L, Brade H, Evans SV. Exploring the cross-reactivity of S25-2: complex with a 5,6-dehydro-Kdo disaccharide. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:2-5. [PMID: 23295476 PMCID: PMC3539693 DOI: 10.1107/s1744309112047422] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 11/19/2012] [Indexed: 11/10/2022]
Abstract
The near-germline antibody S25-2 exhibits a remarkable cross-reactivity for oligosaccharides containing the bacterial lipopolysaccharide carbohydrate 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo). The recent synthesis of a variety of Kdo analogues permits a detailed structural analysis of the importance of specific interactions in antigen recognition by S25-2. The Kdo disaccharide analogue Kdo-(2→4)-5,6-dehydro-Kdo lacks a 5-OH group on the second Kdo residue and has been cocrystallized with S25-2. The structure reveals that the modification of the Kdo residue at position 5 results in a rearrangement of intramolecular hydrogen bonds in the antigen that allows it to assume a novel conformation in the antibody-combining site. The cross-reactive binding of S25-2 to this synthetic ligand highlights the adaptability of this antibody to non-natural synthetic analogues.
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Affiliation(s)
- Cory L. Brooks
- Department of Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC V8W 3P6, Canada
| | - Kurt Wimmer
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Paul Kosma
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Sven Müller-Loennies
- Research Center Borstel Leibniz Center for Medicine and Biosciences, Parkallee 22, D-23845 Borstel, Germany
| | - Lore Brade
- Research Center Borstel Leibniz Center for Medicine and Biosciences, Parkallee 22, D-23845 Borstel, Germany
| | - Helmut Brade
- Research Center Borstel Leibniz Center for Medicine and Biosciences, Parkallee 22, D-23845 Borstel, Germany
| | - Stephen V. Evans
- Department of Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC V8W 3P6, Canada
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47
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2G12-expressing B cell lines may aid in HIV carbohydrate vaccine design strategies. J Virol 2012; 87:2234-41. [PMID: 23221565 DOI: 10.1128/jvi.02820-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The highly conserved cluster of high-mannose glycans on the HIV-1 envelope glycoprotein, gp120, has been highlighted as a target for neutralizing antibodies. 2G12, the first HIV-1 antiglycan neutralizing antibody described, binds with an unusual domain-exchanged structure that creates a high-affinity multivalent binding surface. It is an interesting challenge for rational vaccine design to generate immunogens capable of eliciting domain-exchanged 2G12-like responses. We recently showed that di-mannose recognition by the variable domains of 2G12 is independent of domain exchange but that exchange is critical for virus neutralization. Carbohydrate-based immunogens aimed at inducing 2G12-like antibodies may need to drive both di-mannose recognition and domain exchange through interactions with B cell receptors. Here we assessed the ability of such immunogens to activate mouse B cell lines displaying domain-exchanged wild-type 2G12 (2G12 WT), a non-domain-exchanged Y-shaped variant (2G12 I19R), and germ line 2G12 (2G12 gl). We show that several immunogens, including heat-killed yeast and bacteria, can activate both 2G12 WT and 2G12 I19R B cells. However, only discrete clusters of high-mannose glycans, as on recombinant forms of the HIV-1 envelope trimer and oligodendrons, activate 2G12 WT B cells. Furthermore, no immunogen tested activated 2G12 gl cells. Our results support the hypothesis that in order to drive domain exchange of an antimannose antibody response, a boost with an immunogen displaying discrete clusters of high-mannose glycans not recognized by conventional Y-shaped antibodies will be required. Additionally, a molecule capable of activating 2G12 gl cells might also be required. The results highlight broadly neutralizing antibody-expressing mouse B cells as potentially useful tools for carbohydrate immunogen screening.
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48
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Antibody recognition of cancer-related gangliosides and their mimics investigated using in silico site mapping. PLoS One 2012; 7:e35457. [PMID: 22536387 PMCID: PMC3334985 DOI: 10.1371/journal.pone.0035457] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 03/19/2012] [Indexed: 11/27/2022] Open
Abstract
Modified gangliosides may be overexpressed in certain types of cancer, thus, they are considered a valuable target in cancer immunotherapy. Structural knowledge of their interaction with antibodies is currently limited, due to the large size and high flexibility of these ligands. In this study, we apply our previously developed site mapping technique to investigate the recognition of cancer-related gangliosides by anti-ganglioside antibodies. The results reveal a potential ganglioside-binding motif in the four antibodies studied, suggesting the possibility of structural convergence in the anti-ganglioside immune response. The structural basis of the recognition of ganglioside-mimetic peptides is also investigated using site mapping and compared to ganglioside recognition. The peptides are shown to act as structural mimics of gangliosides by interacting with many of the same binding site residues as the cognate carbohydrate epitopes. These studies provide important clues as to the structural basis of immunological mimicry of carbohydrates.
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49
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Khan T, Salunke DM. Structural elucidation of the mechanistic basis of degeneracy in the primary humoral response. THE JOURNAL OF IMMUNOLOGY 2012; 188:1819-27. [PMID: 22266283 DOI: 10.4049/jimmunol.1102701] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mechanistic basis for efficient combating of the infinite range of foreign Ags by the limited repertoire of naive Abs expressed on primary B cell surfaces during their first encounter was addressed through elegantly designed crystallographic analyses. Resolution of the discrepancy arising from the limited number of possible germline Ab receptors on primary B cells for recognizing the unlimited pool of possible Ags has been attempted by invoking the degenerate recognition potential of the germline Abs. Structural analyses of germline mAb BBE6.12H3 in an Ag-free state, as well as bound to four different peptide Ags, established the correlation of its degenerate specificity with conformational versatility of the paratope. Six distinct paratope topologies observed for a single germline mAb provided a quantitative description of the primary Ag recognition repertoire at the tertiary structural level. Each of the four different peptide Ags was bound specifically to a distinct conformation of the paratope, which was also different from that of the Ag-free states of the same germline mAb. A minimal conserved motif in the pristine Ag-combining site essential for multispecificity and Ag binding-mediated change in the elbow angle of Fab was also discernible. It is proposed that the generation of a primary Ab repertoire involves large, yet finite, germline Ab clones, each capable of adopting discrete conformations, which in turn exhibit diverse binding modes.
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Affiliation(s)
- Tarique Khan
- Structural Biology Unit, National Institute of Immunology, New Delhi 110 067, India
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Choi Y, Deane CM. Predicting antibody complementarity determining region structures without classification. MOLECULAR BIOSYSTEMS 2011; 7:3327-34. [PMID: 22011953 DOI: 10.1039/c1mb05223c] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Antibodies are used extensively in medical and biological research. Their complementarity determining regions (CDRs) define the majority of their antigen binding functionality. CDR structures have been intensively studied and classified (canonical structures). Here we show that CDR structure prediction is no different from the standard loop structure prediction problem and predict them without classification. FREAD, a successful database loop prediction technique, is able to produce accurate predictions for all CDR loops (0.81, 0.42, 0.96, 0.98, 0.88 and 2.25 Å RMSD for CDR-L1 to CDR-H3). In order to overcome the relatively poor predictions of CDR-H3, we developed two variants of FREAD, one focused on sequence similarity (FREAD-S) and another which includes contact information (ConFREAD). Both of the methods improve accuracy for CDR-H3 to 1.34 Å and 1.23 Å respectively. The FREAD variants are also tested on homology models and compared to RosettaAntibody (CDR-H3 prediction on models: 1.98 and 2.62 Å for ConFREAD and RosettaAntibody respectively). CDRs are known to change their structural conformations upon binding the antigen. Traditional CDR classifications are based on sequence similarity and do not account for such environment changes. Using a set of antigen-free and antigen-bound structures, we compared our FREAD variants. ConFREAD which includes contact information successfully discriminates the bound and unbound CDR structures and achieves an accuracy of 1.35 Å for bound structures of CDR-H3.
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Affiliation(s)
- Yoonjoo Choi
- Department of Statistics, Oxford University, 1 South Parks Road, Oxford OX1 3TG, UK
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