1
|
Pomés A, Smith SA, Chruszcz M, Mueller GA, Brackett NF, Chapman MD. Precision engineering for localization, validation, and modification of allergenic epitopes. J Allergy Clin Immunol 2024; 153:560-571. [PMID: 38181840 PMCID: PMC10939758 DOI: 10.1016/j.jaci.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/20/2023] [Accepted: 12/29/2023] [Indexed: 01/07/2024]
Abstract
The allergen-IgE interaction is essential for the genesis of allergic responses, yet investigation of the molecular basis of these interactions is in its infancy. Precision engineering has unveiled the molecular features of allergen-antibody interactions at the atomic level. High-resolution technologies, including x-ray crystallography, nuclear magnetic resonance spectroscopy, and cryo-electron microscopy, determine allergen-antibody structures. X-ray crystallography of an allergen-antibody complex localizes in detail amino acid residues and interactions that define the epitope-paratope interface. Multiple structures involving murine IgG mAbs have recently been resolved. The number of amino acids forming the epitope broadly correlates with the epitope area. The production of human IgE mAbs from B cells of allergic subjects is an exciting recent development that has for the first time enabled an actual IgE epitope to be defined. The biologic activity of defined IgE epitopes can be validated in vivo in animal models or by measuring mediator release from engineered basophilic cell lines. Finally, gene-editing approaches using the Clustered Regularly Interspaced Short Palindromic Repeats technology to either remove allergen genes or make targeted epitope engineering at the source are on the horizon. This review presents an overview of the identification and validation of allergenic epitopes by precision engineering.
Collapse
Affiliation(s)
| | - Scott A Smith
- Vanderbilt University Medical Center, Nashville, Tenn
| | | | | | | | | |
Collapse
|
2
|
Vester SK, Davies AM, Beavil RL, Sandhar BS, Beavil AJ, Gould HJ, Sutton BJ, McDonnell JM. Expanding the Anti-Phl p 7 Antibody Toolkit: An Anti-Idiotype Nanobody Inhibitor. Antibodies (Basel) 2023; 12:75. [PMID: 37987253 PMCID: PMC10660547 DOI: 10.3390/antib12040075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/08/2023] [Accepted: 11/10/2023] [Indexed: 11/22/2023] Open
Abstract
We have previously produced a toolkit of antibodies, comprising recombinant human antibodies of all but one of the human isotypes, directed against the polcalcin family antigen Phl p 7. In this work, we complete the toolkit of human antibody isotypes with the IgD version of the anti-Phl p 7 monoclonal antibody. We also raised a set of nanobodies against the IgD anti-Phl p 7 antibody and identify and characterize one paratope-specific nanobody. This nanobody also binds to the IgE isotype of this antibody, which shares the same idiotype, and orthosterically inhibits the interaction with Phl p 7. The 2.1 Å resolution X-ray crystal structure of the nanobody in complex with the IgD Fab is described.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - James M. McDonnell
- Randall Centre for Cell and Molecular Biophysics, King’s College London, New Hunt’s House, London SE1 1UL, UK; (S.K.V.); (A.M.D.); (R.L.B.); (B.S.S.); (A.J.B.); (H.J.G.); (B.J.S.)
| |
Collapse
|
3
|
Zhang Y, Che H, Li C, Jin T. Food Allergens of Plant Origin. Foods 2023; 12:foods12112232. [PMID: 37297475 DOI: 10.3390/foods12112232] [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: 04/15/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
This review presents an update on the physical, chemical, and biological properties of food allergens in plant sources, focusing on the few protein families that contribute to multiple food allergens from different species and protein families recently found to contain food allergens. The structures and structural components of the food allergens in the allergen families may provide further directions for discovering new food allergens. Answers as to what makes some food proteins allergens are still elusive. Factors to be considered in mitigating food allergens include the abundance of the protein in a food, the property of short stretches of the sequence of the protein that may constitute linear IgE binding epitopes, the structural properties of the protein, its stability to heat and digestion, the food matrix the protein is in, and the antimicrobial activity to the microbial flora of the human gastrointestinal tract. Additionally, recent data suggest that widely used techniques for mapping linear IgE binding epitopes need to be improved by incorporating positive controls, and methodologies for mapping conformational IgE binding epitopes need to be developed.
Collapse
Affiliation(s)
- Yuzhu Zhang
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710, USA
| | - Huilian Che
- Key Laboratory of Precision Nutrition and Food Quality, Key Laboratory of Functional Dairy, Ministry of Education, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Caiming Li
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710, USA
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi 214122, China
| | - Tengchuan Jin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China
| |
Collapse
|
4
|
Davies AM, Beavil RL, Barbolov M, Sandhar BS, Gould HJ, Beavil AJ, Sutton BJ, McDonnell JM. Crystal structures of the human IgD Fab reveal insights into C H1 domain diversity. Mol Immunol 2023; 159:28-37. [PMID: 37267832 DOI: 10.1016/j.molimm.2023.05.006] [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: 03/29/2023] [Revised: 05/17/2023] [Accepted: 05/20/2023] [Indexed: 06/04/2023]
Abstract
Antibodies of the IgD isotype remain the least well characterized of the mammalian immunoglobulin isotypes. Here we report three-dimensional structures for the Fab region of IgD, based on four different crystal structures, at resolutions of 1.45-2.75 Å. These IgD Fab crystals provide the first high-resolution views of the unique Cδ1 domain. Structural comparisons identify regions of conformational diversity within the Cδ1 domain, as well as among the homologous domains of Cα1, Cγ1 and Cμ1. The IgD Fab structure also possesses a unique conformation of the upper hinge region, which may contribute to the overall disposition of the very long linker sequence between the Fab and Fc regions found in human IgD. Structural similarities observed between IgD and IgG, and differences with IgA and IgM, are consistent with predicted evolutionary relationships for the mammalian antibody isotypes.
Collapse
Affiliation(s)
- Anna M Davies
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - Rebecca L Beavil
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - Momchil Barbolov
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - Balraj S Sandhar
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - Hannah J Gould
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - Andrew J Beavil
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - Brian J Sutton
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom
| | - James M McDonnell
- King's College London, Randall Centre for Cell and Molecular Biophysics, New Hunt's House, London SE1 1UL, United Kingdom.
| |
Collapse
|
5
|
Chang HCH, Harrington B, Fu F, Rockmore DN. Complex systems of secrecy: the offshore networks of oligarchs. PNAS NEXUS 2023; 2:pgad051. [PMID: 36909828 PMCID: PMC9998034 DOI: 10.1093/pnasnexus/pgad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/16/2022] [Accepted: 02/02/2023] [Indexed: 03/05/2023]
Abstract
Following the invasion of Ukraine, the USA, UK, and EU governments-among others-sanctioned oligarchs close to Putin. This approach has come under scrutiny, as evidence has emerged of the oligarchs' successful evasion of these punishments. To address this problem, we analyze the role of an overlooked but highly influential group: the secretive professional intermediaries who create and administer the oligarchs' offshore financial empires. Drawing on the Offshore Leaks Database provided by the International Consortium of Investigative Journalists (ICIJ), we examine the ties linking offshore expert advisors (lawyers, accountants, and other wealth management professionals) to ultra-high-net-worth individuals from four countries: Russia, China, the USA, and Hong Kong. We find that resulting nation-level "oligarch networks" share a scale-free structure characterized by a heterogeneity of heavy-tailed degree distributions of wealth managers; however, network topologies diverge across clients from democratic versus autocratic regimes. While generally robust, scale-free networks are fragile when targeted by attacks on highly connected nodes. Our "knock-out" experiments pinpoint this vulnerability to the small group of wealth managers themselves, suggesting that sanctioning these professional intermediaries may be more effective and efficient in disrupting dark finance flows than sanctions on their wealthy clients. This vulnerability is especially pronounced amongst Russian oligarchs, who concentrate their offshore business in a handful of boutique wealth management firms. The distinctive patterns we identify suggest a new approach to sanctions, focused on expert intermediaries to disrupt the finances and alliances of their wealthy clients. More generally, our research contributes to the larger body of work on complexity science and the structures of secrecy.
Collapse
Affiliation(s)
| | | | - Feng Fu
- Department of Mathematics, Dartmouth College, Hanover, NH 03755, USA
| | | |
Collapse
|
6
|
Hofer F, Fischer AL, Kamenik AS, Waibl F, Fernández-Quintero ML, Liedl KR. pH-dependent structural diversity of profilin allergens determines thermal stability. FRONTIERS IN ALLERGY 2022; 3:1007000. [PMID: 36324331 PMCID: PMC9618696 DOI: 10.3389/falgy.2022.1007000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/20/2022] [Indexed: 11/05/2022] Open
Abstract
The family of profilin allergens is a common class of proteins found in plants, viruses and various eukaryotes including mammals. Profilins are characterized by an evolutionary conserved structural fold, which is responsible for their cross-reactive nature of Immunoglobulin E (IgE) antibodies. Despite their high overall structural similarity, they exhibit substantial differences in their biophysical properties, such as thermal and pH stability. To understand the origin of these functional differences of Amb a 8, Art v 4 and Bet v 2, we performed constant pH molecular dynamics simulation in combination with Gaussian accelerated MD simulations. Depending on the respective protonation at different pH levels, we find distinct differences in conformational flexibility, which are consistent with experimentally determined melting temperatures. These variations in flexibility are accompanied by ensemble shifts in the conformational landscape and quantified and localized by residue-wise B-factors and dihedral entropies. These findings strengthen the link between flexibility of profilin allergens and their thermal stability. Thus, our results clearly show the importance of considering protonation dependent conformational ensembles in solution to elucidate biophysical differences between these structurally similar allergens.
Collapse
|
7
|
García-Ramírez B, Mares-Mejía I, Rodríguez-Hernández A, Cano-Sánchez P, Torres-Larios A, Ortega E, Rodríguez-Romero A. A native IgE in complex with profilin provides insights into allergen recognition and cross-reactivity. Commun Biol 2022; 5:748. [PMID: 35902770 PMCID: PMC9334453 DOI: 10.1038/s42003-022-03718-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 07/14/2022] [Indexed: 12/01/2022] Open
Abstract
Allergies have become a rising health problem, where plentiful substances can trigger IgE-mediated allergies in humans. While profilins are considered minor allergens, these ubiquitous proteins are primary molecules involved in cross-reactivity and pollen-food allergy syndrome. Here we report the first crystal structures of murine Fab/IgE, with its chains naturally paired, in complex with the allergen profilin from Hevea brasiliensis (Hev b 8). The crystallographic models revealed that the IgE's six complementarity-determining regions (CDRs) interact with the allergen, comprising a rigid paratope-epitope surface of 926 Å2, which includes an extensive network of interactions. Interestingly, we also observed previously unreported flexibility at Fab/IgE's elbow angle, which did not influence the shape of the paratope. The Fab/IgE exhibits a high affinity for Hev b 8, even when using 1 M NaCl in BLI experiments. Finally, based on the encouraging cross-reactivity assays using two mutants of the maize profilin (Zea m 12), this antibody could be a promising tool in IgE engineering for diagnosis and research applications.
Collapse
Affiliation(s)
- Benjamín García-Ramírez
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
| | - Israel Mares-Mejía
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
| | - Annia Rodríguez-Hernández
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
| | - Patricia Cano-Sánchez
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
| | - Alfredo Torres-Larios
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
| | - Enrique Ortega
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
| | - Adela Rodríguez-Romero
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico.
| |
Collapse
|
8
|
Khatri K, Richardson CM, Glesner J, Kapingidza AB, Mueller GA, Zhang J, Dolamore C, Vailes LD, Wünschmann S, Peebles RS, Chapman MD, Smith SA, Chruszcz M, Pomés A. Human IgE monoclonal antibody recognition of mite allergen Der p 2 defines structural basis of an epitope for IgE cross-linking and anaphylaxis in vivo. PNAS NEXUS 2022; 1:pgac054. [PMID: 35799831 PMCID: PMC9248284 DOI: 10.1093/pnasnexus/pgac054] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 05/24/2022] [Indexed: 01/28/2023]
Abstract
Immunoglobulin E (IgE) antibody is a critical effector molecule for adaptive allergen-induced immune responses, which affect up to 40% of the population worldwide. Allergens are usually innocuous molecules but induce IgE antibody production in allergic subjects. Allergen cross-linking of IgE bound to its high affinity receptor (FcεRI) on mast cells and basophils triggers release of histamine and other mediators that cause allergic symptoms. Little is known about the direct allergen-IgE antibody interaction due to the polyclonal nature of serum IgE and the low frequency of IgE-producing B cells in blood. Here, we report the X-ray crystal structure of a house dust mite allergen, Der p 2, in complex with Fab of a human IgE monoclonal antibody (mAb) isolated by hybridoma technology using human B cells from an allergic subject. This IgE mAb, 2F10, has the correct pairing of heavy and light chains as it occurs in vivo. Key amino acids forming the IgE epitope on Der p 2 were identified. Mutation of these residues ablated their functional ability to cross-link IgE in a mouse model of passive systemic anaphylaxis. These analyses revealed an important conformational epitope associated with the IgE antibody repertoire to a major mite allergen.
Collapse
Affiliation(s)
- Kriti Khatri
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | | | | | - Anyway Brenda Kapingidza
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Geoffrey A Mueller
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Jian Zhang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Cole Dolamore
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | | | | | - R Stokes Peebles
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Scott A Smith
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | | |
Collapse
|
9
|
Bispecific T-Cell Engagers Targeting Membrane-Bound IgE. Biomedicines 2021; 9:biomedicines9111568. [PMID: 34829798 PMCID: PMC8615095 DOI: 10.3390/biomedicines9111568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/07/2021] [Accepted: 10/26/2021] [Indexed: 11/21/2022] Open
Abstract
The increased incidence of allergies and asthma has sparked interest in IgE, the central player in the allergic response. Interaction with its high-affinity receptor FcεRI leads to sensitization and allergen presentation, extracellular membrane-proximal domain in membrane IgE can act as an antigen receptor on B cells, and the interaction with low-affinity IgE receptor CD23 additionally influences its homeostatic range. Therapeutic anti-IgE antibodies act by the inhibition of IgE functions by interfering with its receptor binding or by the obliteration of IgE-B cells, causing a reduction of serum IgE levels. Fusion proteins of antibody fragments that can act as bispecific T-cell engagers have proven very potent in eliciting cytotoxic T-lymphocyte-mediated killing. We have tested five anti-IgE Fc antibodies, recognizing different epitopes on the membrane-expressed IgE, for the ability to elicit specific T-cell activation when expressed as single-chain Fv fragments fused with anti-CD3ε single-chain antibody. All candidates could specifically stain the cell line, expressing the membrane-bound IgE-Fc and bind to CD3-positive Jurkat cells, and the specific activation of engineered CD3-overexpressing Jurkat cells and non-stimulated CD8-positive cells was demonstrated for 8D6- and ligelizumab-based bispecific antibodies. Thus, such anti-IgE antibodies have the potential to be developed into agents that reduce the serum IgE concentration by lowering the numbers of IgE-secreting cells.
Collapse
|
10
|
Ohm-Laursen L, Meng H, Hoehn KB, Nouri N, Jiang Y, Clouser C, Johnstone TG, Hause R, Sandhar BS, Upton NEG, Chevretton EB, Lakhani R, Corrigan CJ, Kleinstein SH, Gould HJ. B Cell Mobilization, Dissemination, Fine Tuning of Local Antigen Specificity and Isotype Selection in Asthma. Front Immunol 2021; 12:702074. [PMID: 34721376 PMCID: PMC8552043 DOI: 10.3389/fimmu.2021.702074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/06/2021] [Indexed: 12/30/2022] Open
Abstract
In order to better understand how the immune system interacts with environmental triggers to produce organ-specific disease, we here address the hypothesis that B and plasma cells are free to migrate through the mucosal surfaces of the upper and lower respiratory tracts, and that their total antibody repertoire is modified in a common respiratory tract disease, in this case atopic asthma. Using Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) we have catalogued the antibody repertoires of B cell clones retrieved near contemporaneously from multiple sites in the upper and lower respiratory tract mucosa of adult volunteers with atopic asthma and non-atopic controls and traced their migration. We show that the lower and upper respiratory tracts are immunologically connected, with trafficking of B cells directionally biased from the upper to the lower respiratory tract and points of selection when migrating from the nasal mucosa and into the bronchial mucosa. The repertoires are characterized by both IgD-only B cells and others undergoing class switch recombination, with restriction of the antibody repertoire distinct in asthmatics compared with controls. We conclude that B cells and plasma cells migrate freely throughout the respiratory tract and exhibit distinct antibody repertoires in health and disease.
Collapse
Affiliation(s)
- Line Ohm-Laursen
- Randall Centre for Cell and Molecular Biophysics and School of Basic and Medical Biosciences, King’s College London, London, United Kingdom
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
| | - Hailong Meng
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | - Kenneth B. Hoehn
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | - Nima Nouri
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
- Center for Medical Informatics, Yale School of Medicine, New Haven, CT, United States
| | - Yue Jiang
- Bristol Myers Squibb, Seattle, WA, United States
| | | | | | - Ron Hause
- Bristol Myers Squibb, Seattle, WA, United States
| | - Balraj S. Sandhar
- Randall Centre for Cell and Molecular Biophysics and School of Basic and Medical Biosciences, King’s College London, London, United Kingdom
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
| | - Nadine E. G. Upton
- Randall Centre for Cell and Molecular Biophysics and School of Basic and Medical Biosciences, King’s College London, London, United Kingdom
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
| | - Elfy B. Chevretton
- Department of Ear, Nose and Throat (ENT) Services, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Raj Lakhani
- Department of Ear, Nose and Throat (ENT) Services, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Chris J. Corrigan
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
- Department of Respiratory Medicine and Allergy and School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Steven H. Kleinstein
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT, United States
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, United States
| | - Hannah J. Gould
- Randall Centre for Cell and Molecular Biophysics and School of Basic and Medical Biosciences, King’s College London, London, United Kingdom
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
| |
Collapse
|
11
|
Hofer F, Kamenik AS, Fernández-Quintero ML, Kraml J, Liedl KR. pH-Induced Local Unfolding of the Phl p 6 Pollen Allergen From cpH-MD. Front Mol Biosci 2021; 7:603644. [PMID: 33511157 PMCID: PMC7835895 DOI: 10.3389/fmolb.2020.603644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/10/2020] [Indexed: 11/13/2022] Open
Abstract
Susceptibility to endosomal degradation is a decisive contribution to a protein's immunogenicity. It is assumed that the processing kinetics of structured proteins are inherently linked to their probability of local unfolding. In this study, we quantify the impact of endosomal acidification on the conformational stability of the major timothy grass pollen allergen Phl p 6. We use state of the art sampling approaches in combination with constant pH MD techniques to profile pH-dependent local unfolding events in atomistic detail. Integrating our findings into the current view on type 1 allergic sensitization, we characterize local protein dynamics in the context of proteolytic degradation at neutral and acidic pH for the wild type protein and point mutants with varying proteolytic stability. We analyze extensive simulation data using Markov state models and retrieve highly reliable thermodynamic and kinetic information at varying pH levels. Thereby we capture the impact of endolysosomal acidification on the structure and dynamics of the Phl p 6 mutants. We find that upon protonation at lower pH values, the conformational flexibilities in key areas of the wild type protein, i.e., T-cell epitopes and early proteolytic cleavage sites, increase significantly. A decrease of the pH even leads to local unfolding in otherwise stable secondary structure elements, which is a prerequisite for proteolytic cleavage. This effect is even more pronounced in the destabilized mutant, while no unfolding was observed for the stabilized mutant. In summary, we report detailed structural models which rationalize the experimentally observed cleavage pattern during endosomal acidification.
Collapse
|
12
|
Pomés A, Mueller GA, Chruszcz M. Structural Aspects of the Allergen-Antibody Interaction. Front Immunol 2020; 11:2067. [PMID: 32983155 PMCID: PMC7492603 DOI: 10.3389/fimmu.2020.02067] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/29/2020] [Indexed: 12/23/2022] Open
Abstract
The development of allergic disease involves the production of IgE antibodies upon allergen exposure in a process called sensitization. IgE binds to receptors on the surface of mast cells and basophils, and subsequent allergen exposure leads to cross-linking of IgE antibodies and release of cell mediators that cause allergy symptoms. Although this process is quite well-understood, very little is known about the epitopes on the allergen recognized by IgE, despite the importance of the allergen-antibody interaction for the allergic response to occur. This review discusses efforts to analyze allergen-antibody interactions, from the original epitope mapping studies using linear peptides or recombinant allergen fragments, to more sophisticated technologies, such as X-ray crystallography and nuclear magnetic resonance. These state-of-the-art approaches, combined with site-directed mutagenesis, have led to the identification of conformational IgE epitopes. The first structures of an allergen (egg lysozyme) in complex with Fab fragments from IgG antibodies were determined in the 1980s. Since then, IgG has been used as surrogate for IgE, due to the difficulty of obtaining monoclonal IgE antibodies. Technical developments including phage display libraries have contributed to progress in epitope mapping thanks to the isolation of IgE antibody constructs from combinatorial libraries made from peripheral blood mononuclear cells of allergic donors. Most recently, single B cell antibody sequencing and human hybridomas are new breakthrough technologies for finally obtaining human IgE monoclonal antibodies, ideal for epitope mapping. The information on antigenic determinants will facilitate the design of hypoallergens for immunotherapy and the investigation of the fundamental mechanisms of the IgE response.
Collapse
Affiliation(s)
- Anna Pomés
- Indoor Biotechnologies, Inc., Charlottesville, VA, United States
| | - Geoffrey A Mueller
- National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, United States
| |
Collapse
|
13
|
Lefranc MP, Lefranc G. Immunoglobulins or Antibodies: IMGT ® Bridging Genes, Structures and Functions. Biomedicines 2020; 8:E319. [PMID: 32878258 PMCID: PMC7555362 DOI: 10.3390/biomedicines8090319] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/23/2020] [Accepted: 08/25/2020] [Indexed: 12/18/2022] Open
Abstract
IMGT®, the international ImMunoGeneTics® information system founded in 1989 by Marie-Paule Lefranc (Université de Montpellier and CNRS), marked the advent of immunoinformatics, a new science at the interface between immunogenetics and bioinformatics. For the first time, the immunoglobulin (IG) or antibody and T cell receptor (TR) genes were officially recognized as 'genes' as well as were conventional genes. This major breakthrough has allowed the entry, in genomic databases, of the IG and TR variable (V), diversity (D) and joining (J) genes and alleles of Homo sapiens and of other jawed vertebrate species, based on the CLASSIFICATION axiom. The second major breakthrough has been the IMGT unique numbering and the IMGT Collier de Perles for the V and constant (C) domains of the IG and TR and other proteins of the IG superfamily (IgSF), based on the NUMEROTATION axiom. IMGT-ONTOLOGY axioms and concepts bridge genes, sequences, structures and functions, between biological and computational spheres in the IMGT® system (Web resources, databases and tools). They provide the IMGT Scientific chart rules to identify, to describe and to analyse the IG complex molecular data, the huge diversity of repertoires, the genetic (alleles, allotypes, CNV) polymorphisms, the IG dual function (paratope/epitope, effector properties), the antibody humanization and engineering.
Collapse
Affiliation(s)
- Marie-Paule Lefranc
- IMGT, The International ImMunoGeneTics Information System, Laboratoire d’ImmunoGénétique Moléculaire LIGM, Institut de Génétique Humaine IGH, Université de Montpellier UM, Centre National de la Recherche Scientifique CNRS, UMR 9002 CNRS-UM, 141 Rue de la Cardonille, CEDEX 5, 34396 Montpellier, France
| | - Gérard Lefranc
- IMGT, The International ImMunoGeneTics Information System, Laboratoire d’ImmunoGénétique Moléculaire LIGM, Institut de Génétique Humaine IGH, Université de Montpellier UM, Centre National de la Recherche Scientifique CNRS, UMR 9002 CNRS-UM, 141 Rue de la Cardonille, CEDEX 5, 34396 Montpellier, France
| |
Collapse
|
14
|
Kamenik AS, Hofer F, Handle PH, Liedl KR. Dynamics Rationalize Proteolytic Susceptibility of the Major Birch Pollen Allergen Bet v 1. Front Mol Biosci 2020; 7:18. [PMID: 32154264 PMCID: PMC7045072 DOI: 10.3389/fmolb.2020.00018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/31/2020] [Indexed: 12/21/2022] Open
Abstract
Proteolytic susceptibility during endolysosomal degradation is decisive for allergic sensitization. In the major birch pollen allergen Bet v 1 most protease cleavage sites are located within its secondary structure elements, which are inherently inaccessible to proteases. The allergen thus must unfold locally, exposing the cleavage sites to become susceptible to proteolysis. Hence, allergen cleavage rates are presumed to be linked to their fold stability, i.e., unfolding probability. Yet, these locally unfolded structures have neither been captured in experiment nor simulation due to limitations in resolution and sampling time, respectively. Here, we perform classic and enhanced molecular dynamics (MD) simulations to quantify fold dynamics on extended timescales of Bet v 1a and two variants with higher and lower cleavage rates. Already at the nanosecond-timescale we observe a significantly higher flexibility for the destabilized variant compared to Bet v 1a and the proteolytically stabilized mutant. Estimating the thermodynamics and kinetics of local unfolding around an initial cleavage site, we find that the Bet v 1 variant with the highest cleavage rate also shows the highest probability for local unfolding. For the stabilized mutant on the other hand we only find minimal unfolding probability. These results strengthen the link between the conformational dynamics of allergen proteins and their stability during endolysosomal degradation. The presented approach further allows atomistic insights in the conformational ensemble of allergen proteins and provides probability estimates below experimental detection limits.
Collapse
Affiliation(s)
| | | | | | - Klaus R. Liedl
- Center for Molecular Biosciences Innsbruck, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
15
|
Abstract
In vertebrates, immunoglobulins (Igs), commonly known as antibodies, play an integral role in the armamentarium of immune defense against various pathogens. After an antigenic challenge, antibodies are secreted by differentiated B cells called plasma cells. Antibodies have two predominant roles that involve specific binding to antigens to launch an immune response, along with activation of other components of the immune system to fight pathogens. The ability of immunoglobulins to fight against innumerable and diverse pathogens lies in their intrinsic ability to discriminate between different antigens. Due to this specificity and high affinity for their antigens, antibodies have been a valuable and indispensable tool in research, diagnostics and therapy. Although seemingly a simple maneuver, the association between an antibody and its antigen, to make an antigen-antibody complex, is comprised of myriads of non-covalent interactions. Amino acid residues on the antigen binding site, the epitope, and on the antibody binding site, the paratope, intimately contribute to the energetics needed for the antigen-antibody complex stability. Structural biology methods to study antigen-antibody complexes are extremely valuable tools to visualize antigen-antibody interactions in detail; this helps to elucidate the basis of molecular recognition between an antibody and its specific antigen. The main scope of this chapter is to discuss the structure and function of different classes of antibodies and the various aspects of antigen-antibody interactions including antigen-antibody interfaces-with a special focus on paratopes, complementarity determining regions (CDRs) and other non-CDR residues important for antigen binding and recognition. Herein, we also discuss methods used to study antigen-antibody complexes, antigen recognition by antibodies, types of antigens in complexes, and how antigen-antibody complexes play a role in modern day medicine and human health. Understanding the molecular basis of antigen binding and recognition by antibodies helps to facilitate the production of better and more potent antibodies for immunotherapy, vaccines and various other applications.
Collapse
Affiliation(s)
- A Brenda Kapingidza
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Krzysztof Kowal
- Department of Allergology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland
- Department of Experimental Allergology and Immunology, Medical University of Bialystok, Bialystok, Poland
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA.
| |
Collapse
|
16
|
Fernández-Quintero ML, Loeffler JR, Waibl F, Kamenik AS, Hofer F, Liedl KR. Conformational selection of allergen-antibody complexes-surface plasticity of paratopes and epitopes. Protein Eng Des Sel 2019; 32:513-523. [PMID: 32719844 PMCID: PMC7451023 DOI: 10.1093/protein/gzaa014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 06/26/2020] [Accepted: 06/26/2020] [Indexed: 12/18/2022] Open
Abstract
Antibodies have the ability to bind various types of antigens and to recognize different antibody-binding sites (epitopes) of the same antigen with different binding affinities. Due to the conserved structural framework of antibodies, their specificity to antigens is mainly determined by their antigen-binding site (paratope). Therefore, characterization of epitopes in combination with describing the involved conformational changes of the paratope upon binding is crucial in understanding and predicting antibody-antigen binding. Using molecular dynamics simulations complemented with strong experimental structural information, we investigated the underlying binding mechanism and the resulting local and global surface plasticity in the binding interfaces of distinct antibody-antigen complexes. In all studied allergen-antibody complexes, we clearly observe that experimentally suggested epitopes reveal less plasticity, while non-epitope regions show high surface plasticity. Surprisingly, the paratope shows higher conformational diversity reflected in substantially higher surface plasticity, compared to the epitope. This work allows a visualization and characterization of antibody-antigen interfaces and might have strong implications for antibody-antigen docking and in the area of epitope prediction.
Collapse
Affiliation(s)
- Monica L Fernández-Quintero
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Johannes R Loeffler
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Franz Waibl
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Anna S Kamenik
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Florian Hofer
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry, and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria,To whom correspondence should be addressed. E-Mail:
| |
Collapse
|
17
|
Glesner J, Kapingidza AB, Godzwon M, Offermann LR, Mueller GA, DeRose EF, Wright P, Richardson CM, Woodfolk JA, Vailes LD, Wünschmann S, London RE, Chapman MD, Ohlin M, Chruszcz M, Pomés A. A Human IgE Antibody Binding Site on Der p 2 for the Design of a Recombinant Allergen for Immunotherapy. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2019; 203:2545-2556. [PMID: 31554696 PMCID: PMC6810898 DOI: 10.4049/jimmunol.1900580] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/15/2019] [Indexed: 01/31/2023]
Abstract
Der p 2 is one of the most important allergens from the house dust mite Dermatophagoides pteronyssinus Identification of human IgE Ab binding epitopes can be used for rational design of allergens with reduced IgE reactivity for therapy. Antigenic analysis of Der p 2 was performed by site-directed mutagenesis based on the x-ray crystal structure of the allergen in complex with a Fab from the murine IgG mAb 7A1 that binds an epitope overlapping with human IgE binding sites. Conformational changes upon Ab binding were confirmed by nuclear magnetic resonance using a 7A1-single-chain variable fragment. In addition, a human IgE Ab construct that interferes with mAb 7A1 binding was isolated from a combinatorial phage-display library constructed from a mite-allergic patient and expressed as two recombinant forms (single-chain Fab in Pichia pastoris and Fab in Escherichia coli). These two IgE Ab constructs and the mAb 7A1 failed to recognize two Der p 2 epitope double mutants designed to abolish the allergen-Ab interaction while preserving the fold necessary to bind Abs at other sites of the allergen surface. A 10-100-fold reduction in binding of IgE from allergic subjects to the mutants additionally showed that the residues mutated were involved in IgE Ab binding. In summary, mutagenesis of a Der p 2 epitope defined by x-ray crystallography revealed an IgE Ab binding site that will be considered for the design of hypoallergens for immunotherapy.
Collapse
Affiliation(s)
- Jill Glesner
- Indoor Biotechnologies, Inc., Charlottesville, VA 22903
| | | | | | | | - Geoffrey A Mueller
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709; and
| | - Eugene F DeRose
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709; and
| | - Paul Wright
- University of Virginia, Charlottesville, VA 22903
| | | | | | - Lisa D Vailes
- Indoor Biotechnologies, Inc., Charlottesville, VA 22903
| | | | - Robert E London
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709; and
| | | | | | | | - Anna Pomés
- Indoor Biotechnologies, Inc., Charlottesville, VA 22903;
| |
Collapse
|
18
|
Butyrophilin-like 3 Directly Binds a Human Vγ4 + T Cell Receptor Using a Modality Distinct from Clonally-Restricted Antigen. Immunity 2019; 51:813-825.e4. [PMID: 31628053 PMCID: PMC6868513 DOI: 10.1016/j.immuni.2019.09.006] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 07/12/2019] [Accepted: 09/09/2019] [Indexed: 12/19/2022]
Abstract
Butyrophilin (BTN) and butyrophilin-like (BTNL/Btnl) heteromers are major regulators of human and mouse γδ T cell subsets, but considerable contention surrounds whether they represent direct γδ T cell receptor (TCR) ligands. We demonstrate that the BTNL3 IgV domain binds directly and specifically to a human Vγ4+ TCR, “LES” with an affinity (∼15–25 μM) comparable to many αβ TCR-peptide major histocompatibility complex interactions. Mutations in germline-encoded Vγ4 CDR2 and HV4 loops, but not in somatically recombined CDR3 loops, drastically diminished binding and T cell responsiveness to BTNL3-BTNL8-expressing cells. Conversely, CDR3γ and CDR3δ loops mediated LES TCR binding to endothelial protein C receptor, a clonally restricted autoantigen, with minimal CDR1, CDR2, or HV4 contributions. Thus, the γδ TCR can employ two discrete binding modalities: a non-clonotypic, superantigen-like interaction mediating subset-specific regulation by BTNL/BTN molecules and CDR3-dependent, antibody-like interactions mediating adaptive γδ T cell biology. How these findings might broadly apply to γδ T cell regulation is also examined. BTNL3 binds directly and specifically to Vγ4+ TCRs via its IgV domain The superantigen-like binding mode focuses on germline-encoded TCR regions In contrast, γδ TCR binding to a clonally restricted antigen is CDR3-mediated Mutagenesis indicates parallels with BTN3A1-mediated activation of Vγ9Vδ2 T cells
Collapse
|
19
|
Ilieva KM, Fazekas‐Singer J, Bax HJ, Crescioli S, Montero‐Morales L, Mele S, Sow HS, Stavraka C, Josephs DH, Spicer JF, Steinkellner H, Jensen‐Jarolim E, Tutt ANJ, Karagiannis SN. AllergoOncology: Expression platform development and functional profiling of an anti-HER2 IgE antibody. Allergy 2019; 74:1985-1989. [PMID: 30964550 PMCID: PMC6817356 DOI: 10.1111/all.13818] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Kristina M. Ilieva
- Breast Cancer Now Research Unit, School of Cancer & Pharmaceutical SciencesKing's College London, Guy's Cancer CentreLondonUK
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| | - Judit Fazekas‐Singer
- Institute of Pathophysiology and Allergy ResearchMedical University of ViennaViennaAustria
- The Interuniversity Messerli Research Institute of the University of Veterinary Medicine ViennaMedical University Vienna and University ViennaViennaAustria
| | - Heather J. Bax
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| | - Silvia Crescioli
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| | - Laura Montero‐Morales
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Silvia Mele
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| | - Heng Sheng Sow
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| | - Chara Stavraka
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| | - Debra H. Josephs
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
- School of Cancer & Pharmaceutical SciencesKing's College London, Guy's HopsitalLondonUK
| | - James F. Spicer
- School of Cancer & Pharmaceutical SciencesKing's College London, Guy's HopsitalLondonUK
| | - Herta Steinkellner
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Erika Jensen‐Jarolim
- Institute of Pathophysiology and Allergy ResearchMedical University of ViennaViennaAustria
- The Interuniversity Messerli Research Institute of the University of Veterinary Medicine ViennaMedical University Vienna and University ViennaViennaAustria
| | - Andrew N. J. Tutt
- Breast Cancer Now Research Unit, School of Cancer & Pharmaceutical SciencesKing's College London, Guy's Cancer CentreLondonUK
- Breast Cancer Now Toby Robins Research CentreInstitute of Cancer ResearchLondonUK
| | - Sophia N. Karagiannis
- Breast Cancer Now Research Unit, School of Cancer & Pharmaceutical SciencesKing's College London, Guy's Cancer CentreLondonUK
- St. John's Institute of Dermatology, School of Basic & Medical BiosciencesKing's College London, Guy's HospitalLondonUK
| |
Collapse
|
20
|
Angkawidjaja C, Torashima T. Crystal structure of the Fab region of a neutralizing antibody against granulocyte-macrophage colony-stimulating factor. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2019; 75:634-639. [PMID: 31584011 DOI: 10.1107/s2053230x1901238x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 09/05/2019] [Indexed: 02/24/2023]
Abstract
An increased level of granulocyte-macrophage colony-stimulating factor has a potential role in the development of autoimmune diseases, and the neutralization of its activity by monoclonal antibodies is a promising therapy for some diseases. Here, the crystal structure of the Fab region of EV1007, a fully human antibody expressed in Chinese hamster ovary cells that was developed from human peripheral blood mononuclear cells, is described. The structure closely resembles that of MB007, which is the Fab region of the same antibody expressed in Escherichia coli [Blech et al. (2012), Biochem. J. 447, 205-215], except at the hinge regions between the immunoglobulin domains and the H3 loop region. This paper presents evidence for the flexibility of the hinge and H3 loop regions of the antibody based on the comparison of two independently solved crystal structures.
Collapse
Affiliation(s)
- Clement Angkawidjaja
- Antibody Drug Discovery Laboratory, Evec Inc., Technopark 1-chome, Sapporo Electronics Center, Sapporo, Hokkaido, Japan
| | - Takashi Torashima
- Antibody Drug Discovery Laboratory, Evec Inc., Technopark 1-chome, Sapporo Electronics Center, Sapporo, Hokkaido, Japan
| |
Collapse
|
21
|
Bucaite G, Kang-Pettinger T, Moreira J, Gould HJ, James LK, Sutton BJ, McDonnell JM. Interplay between Affinity and Valency in Effector Cell Degranulation: A Model System with Polcalcin Allergens and Human Patient-Derived IgE Antibodies. THE JOURNAL OF IMMUNOLOGY 2019; 203:1693-1700. [PMID: 31462504 DOI: 10.4049/jimmunol.1900509] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/19/2019] [Indexed: 01/10/2023]
Abstract
An allergic reaction is rapidly generated when allergens bind and cross-link IgE bound to its receptor FcεRI on effector cells, resulting in cell degranulation and release of proinflammatory mediators. The extent of effector cell activation is linked to allergen affinity, oligomeric state, valency, and spacing of IgE-binding epitopes on the allergen. Whereas most of these observations come from studies using synthetic allergens, in this study we have used Timothy grass pollen allergen Phl p 7 and birch pollen allergen Bet v 4 to study these effects. Despite the high homology of these polcalcin family allergens, Phl p 7 and Bet v 4 display different binding characteristics toward two human patient-derived polcalcin-specific IgE Abs. We have used native polcalcin dimers and engineered multimeric allergens to test the effects of affinity and oligomeric state on IgE binding and effector cell activation. Our results indicate that polcalcin multimers are required to stimulate high levels of effector cell degranulation when using the humanized RBL-SX38 cell model and that multivalency can overcome the need for high-affinity interactions.
Collapse
Affiliation(s)
- Gintare Bucaite
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom.,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom
| | - Tara Kang-Pettinger
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom.,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom.,Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom; and
| | - Jorge Moreira
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom.,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom
| | - Hannah J Gould
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom.,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom
| | - Louisa K James
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom.,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom.,Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom
| | - Brian J Sutton
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom.,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom
| | - James M McDonnell
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom; .,Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE1 1UL, United Kingdom
| |
Collapse
|
22
|
Dall'Antonia F, Keller W. SPADE web service for prediction of allergen IgE epitopes. Nucleic Acids Res 2019; 47:W496-W501. [PMID: 31066444 PMCID: PMC6602491 DOI: 10.1093/nar/gkz331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 04/30/2019] [Indexed: 11/12/2022] Open
Abstract
The specific interaction of allergens with IgE antibodies and the allergen mediated cross-linking of receptor-bound IgE are key events of allergic diseases. The elucidation of the IgE binding sites (the epitopes) on the allergen surface is an important goal of allergy research. Only few allergen-specific IgE epitopes have been determined experimentally to date. Epitope prediction methods represent a viable alternative to experimental methods and have worked well with linear epitopes. However, as most IgE epitopes are of conformational and/or discontinuous nature sequence based prediction methods have had limited success in these cases. Here, we present the web server of the program SPADE (https://spade.uni-graz.at), which is the server implementation of a previously published program (1). In this approach we utilize the structural homology of cross-reactive allergens combined with the immunological cross-reactivity data for the discrimination of putative IgE-binding sites from non-cross-reactive surface patches. The method, although predictive, does not rely on machine-learning algorithms and does not require training data. The SPADE server features an easy-to-use interface, an automated pipeline consisting of third-party, as well as own, newly developed routines and a comprehensive output page.
Collapse
Affiliation(s)
- Fabio Dall'Antonia
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany
| | - Walter Keller
- Institute of Molecular Biosciences, BioTechMed, University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| |
Collapse
|
23
|
Mueller GA, Min J, Foo ACY, Pomés A, Pedersen LC. Structural Analysis of Recent Allergen-Antibody Complexes and Future Directions. Curr Allergy Asthma Rep 2019; 19:17. [PMID: 30815753 DOI: 10.1007/s11882-019-0848-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE OF REVIEW Allergen-antibody complexes are extremely valuable in describing the detailed molecular features of epitopes. This review summarizes insights gained from recently published co-structures and what obstacles impede the acquisition of further data. RECENT FINDINGS Structural epitope data helped define the epitopes of two anti-Fel d 1 antibodies undergoing phase I clinical trials, providing a greater level of detail than was possible through hydrogen-deuterium exchange protection studies. Separately, a human camelid-like antibody structure with lysozyme described several unique features in a long variable loop that interacted with the active site cleft of Gal d 4. Finally, a co-structure conclusively demonstrated that Phl p 7 could function as a superantigen and that an antibody could simultaneously recognize two epitopes. These remarkable assertions would not have been possible without visualization of the complex. Only three new complexes have appeared in the last few years, suggesting that there are major impediments to traditional production and crystallization. The structural data was extremely valuable in describing epitopes. New techniques like cryo-EM may provide an alternative to crystallography.
Collapse
Affiliation(s)
- Geoffrey A Mueller
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive MD-MR-01, Research Triangle Park, NC, 27709, USA.
| | - Jungki Min
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive MD-MR-01, Research Triangle Park, NC, 27709, USA
| | - Alexander C Y Foo
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive MD-MR-01, Research Triangle Park, NC, 27709, USA
| | - Anna Pomés
- Indoor Biotechnologies, Inc., Charlottesville, VA, USA
| | - Lars C Pedersen
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive MD-MR-01, Research Triangle Park, NC, 27709, USA
| |
Collapse
|
24
|
Sutton BJ, Davies AM, Bax HJ, Karagiannis SN. IgE Antibodies: From Structure to Function and Clinical Translation. Antibodies (Basel) 2019; 8:E19. [PMID: 31544825 PMCID: PMC6640697 DOI: 10.3390/antib8010019] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 02/11/2019] [Accepted: 02/15/2019] [Indexed: 12/15/2022] Open
Abstract
Immunoglobulin E (IgE) antibodies are well known for their role in mediating allergic reactions, and their powerful effector functions activated through binding to Fc receptors FcεRI and FcεRII/CD23. Structural studies of IgE-Fc alone, and when bound to these receptors, surprisingly revealed not only an acutely bent Fc conformation, but also subtle allosteric communication between the two distant receptor-binding sites. The ability of IgE-Fc to undergo more extreme conformational changes emerged from structures of complexes with anti-IgE antibodies, including omalizumab, in clinical use for allergic disease; flexibility is clearly critical for IgE function, but may also be exploited by allosteric interference to inhibit IgE activity for therapeutic benefit. In contrast, the power of IgE may be harnessed to target cancer. Efforts to improve the effector functions of therapeutic antibodies for cancer have almost exclusively focussed on IgG1 and IgG4 subclasses, but IgE offers an extremely high affinity for FcεRI receptors on immune effector cells known to infiltrate solid tumours. Furthermore, while tumour-resident inhibitory Fc receptors can modulate the effector functions of IgG antibodies, no inhibitory IgE Fc receptors are known to exist. The development of tumour antigen-specific IgE antibodies may therefore provide an improved immune functional profile and enhanced anti-cancer efficacy. We describe proof-of-concept studies of IgE immunotherapies against solid tumours, including a range of in vitro and in vivo evaluations of efficacy and mechanisms of action, as well as ex vivo and in vivo safety studies. The first anti-cancer IgE antibody, MOv18, the clinical translation of which we discuss herein, has now reached clinical testing, offering great potential to direct this novel therapeutic modality against many other tumour-specific antigens. This review highlights how our understanding of IgE structure and function underpins these exciting clinical developments.
Collapse
Affiliation(s)
- Brian J Sutton
- King's College London, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK.
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
| | - Anna M Davies
- King's College London, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK.
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
| | - Heather J Bax
- King's College London, St John's Institute of Dermatology, London SE1 9RT, UK.
| | | |
Collapse
|
25
|
Eckl-Dorna J, Villazala-Merino S, Linhart B, Karaulov AV, Zhernov Y, Khaitov M, Niederberger-Leppin V, Valenta R. Allergen-Specific Antibodies Regulate Secondary Allergen-Specific Immune Responses. Front Immunol 2019; 9:3131. [PMID: 30705676 PMCID: PMC6344431 DOI: 10.3389/fimmu.2018.03131] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 12/18/2018] [Indexed: 01/08/2023] Open
Abstract
Immunoglobulin E (IgE)-associated allergy is the most common immunologically-mediated hypersensensitivity disease. It is based on the production of IgE antibodies and T cell responses against per se innocuous antigens (i.e., allergens) and subsequent allergen-induced inflammation in genetically pre-disposed individuals. While allergen exposure in sensitized subjects mainly boosts IgE production and T cell activation, successful allergen-specific immunotherapy (AIT) induces the production of allergen-specific IgG antibodies and reduces T cell activity. Under both circumstances, the resulting allergen-antibody complexes play a major role in modulating secondary allergen-specific immune responses: Allergen-IgE complexes induce mast cell and basophil activation and perpetuate allergen-specific T cell responses via presentation of allergen by allergen presenting cells to T cells, a process called IgE-facilitated antigen presentation (FAP). In addition, they may induce activation of IgE memory B cells. Allergen-induced production of specific IgGs usually exerts ameliorating effects but under certain circumstances may also contribute to exacerbation. Allergen-specific IgG antibodies induced by AIT which compete with IgE for allergen binding (i.e., blocking IgG) inhibit formation of IgE-allergen complexes and reduce activation of effector cells, B cells and indirectly T cells as FAP is prevented. Experimental data provide evidence that by binding of allergen-specific IgG to epitopes different from those recognized by IgE, allergen-specific IgG may enhance IgE-mediated activation of mast cells, basophils and allergen-specific IgE+ B cells. In this review we provide an overview about the role of allergen-specific antibodies in regulating secondary allergen-specific immune responses.
Collapse
Affiliation(s)
- Julia Eckl-Dorna
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | | | - Birgit Linhart
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Alexander V Karaulov
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Yury Zhernov
- NRC Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Musa Khaitov
- NRC Institute of Immunology FMBA of Russia, Moscow, Russia
| | | | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia.,NRC Institute of Immunology FMBA of Russia, Moscow, Russia
| |
Collapse
|
26
|
|