1
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Barone V, Scirocco L, Surico PL, Micera A, Cutrupi F, Coassin M, Di Zazzo A. Mast cells and ocular surface: An update review. Exp Eye Res 2024; 245:109982. [PMID: 38942134 DOI: 10.1016/j.exer.2024.109982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/10/2024] [Accepted: 06/25/2024] [Indexed: 06/30/2024]
Abstract
Mast cells (MCs), traditionally viewed as key players in IgE-mediated allergic responses, are increasingly recognized for their versatile roles. Situated at critical barrier sites such as the ocular surface, these sentinel cells participate in a broad array of physiological and pathological processes. This review presents a comprehensive update on the immune pathophysiology of MCs, with a particular focus on the mechanisms underlying innate immunity. It highlights their roles at the ocular surface, emphasizing their participation in allergic reactions, maintenance of corneal homeostasis, neovascularization, wound healing, and immune responses in corneal grafts. The review also explores the potential of MCs as therapeutic targets, given their significant contributions to disease pathogenesis and their capacity to modulate immunity. Through a thorough examination of current literature, we aim to elucidate the immune pathophysiology and multifaceted roles of MCs in ocular surface health and disease, suggesting directions for future research and therapeutic innovation.
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Affiliation(s)
- Vincenzo Barone
- Ophthalmology Campus Bio-Medico University, Rome, Italy; Ophthalmology Operative Complex Unit, Campus Bio-Medico University Hospital Foundation, Rome, Italy
| | - Laura Scirocco
- Ophthalmology Campus Bio-Medico University, Rome, Italy; Ophthalmology Operative Complex Unit, Campus Bio-Medico University Hospital Foundation, Rome, Italy
| | - Pier Luigi Surico
- Ophthalmology Campus Bio-Medico University, Rome, Italy; Ophthalmology Operative Complex Unit, Campus Bio-Medico University Hospital Foundation, Rome, Italy; Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Alessandra Micera
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Science, IRCCS - Fondazione Bietti, Rome, Italy
| | - Francesco Cutrupi
- Ophthalmology Campus Bio-Medico University, Rome, Italy; Ophthalmology Operative Complex Unit, Campus Bio-Medico University Hospital Foundation, Rome, Italy
| | - Marco Coassin
- Ophthalmology Campus Bio-Medico University, Rome, Italy; Ophthalmology Operative Complex Unit, Campus Bio-Medico University Hospital Foundation, Rome, Italy
| | - Antonio Di Zazzo
- Ophthalmology Campus Bio-Medico University, Rome, Italy; Ophthalmology Operative Complex Unit, Campus Bio-Medico University Hospital Foundation, Rome, Italy; Rare Corneal Diseases Center, Campus Bio-Medico University Hospital Foundation, Rome, Italy.
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2
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Akin C, Siebenhaar F, Wechsler JB, Youngblood BA, Maurer M. Detecting Changes in Mast Cell Numbers Versus Activation in Human Disease: A Roadblock for Current Biomarkers? THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2024; 12:1727-1737. [PMID: 38467332 DOI: 10.1016/j.jaip.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/09/2024] [Accepted: 03/01/2024] [Indexed: 03/13/2024]
Abstract
The pathophysiology of mast cell (MC)-driven disorders is diverse, ranging from localized reactions to systemic disorders caused by abnormal accumulation and activation in multiorgan systems. Prompt and accurate diagnosis is critically important, both for informing treatment and objective assessment of treatment outcomes. As new therapeutics are being developed to deplete MCs or silence them (eg, by engaging inhibitory receptors that block activation), new biomarkers are needed that can distinguish between MC activation versus burden. Serum tryptase is the gold standard for assessing both MC burden and activation; however, commercial tryptase assays have limitations related to timing of release, lack of discernment between inactive (α) and active (β) forms of tryptase, and interpatient variability of baseline levels. Alternative approaches to measuring MC activation include urinary MC mediators, flow cytometry-based assays or gene expression profiling. Additional markers of MC activation are needed for use in clinical diagnostics, to help selection of treatment of MC diseases, and for assessing outcomes of therapy. We review the spectrum of disorders with known or suspected MC contribution, describe the utility and limitations of current MC markers and assays, and discuss the need for new markers that can differentiate between MC activation and burden.
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Affiliation(s)
- Cem Akin
- Division of Allergy and Clinical Immunology, University of Michigan, Ann Arbor, Mich
| | - Frank Siebenhaar
- Institute of Allergology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany; Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology, Berlin, Germany
| | - Joshua B Wechsler
- Division of Gastroenterology, Hepatology, and Nutrition, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Ill
| | | | - Marcus Maurer
- Institute of Allergology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany; Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology, Berlin, Germany.
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3
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Korver W, Benet Z, Wong A, Negri GL, Chang K, Sanchez R, Leung J, De Freitas N, Luu T, Schanin J, Youngblood BA. Regulation of mast cells by overlapping but distinct protein interactions of Siglec-6 and Siglec-8. Allergy 2024; 79:629-642. [PMID: 38186079 DOI: 10.1111/all.16004] [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: 09/28/2023] [Revised: 11/13/2023] [Accepted: 12/12/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND Sialic acid-binding immunoglobulin-like lectin (Siglec)-6 and Siglec-8 are closely related mast cell (MC) receptors with broad inhibitory activity, but whose functional differences are incompletely understood. METHODS Proteomic profiling using quantitative mass spectrometry was performed on primary mouse MCs to identify proteins associated with Siglec-6 and Siglec-8. For functional characterization, each receptor was evaluated biochemically and in ex vivo and in vivo inhibition models of IgE and non-IgE-mediated MC activation in Siglec-6- or Siglec-8-expressing transgenic mice. RESULTS Siglec-6 and Siglec-8 were found in MCs within large complexes, interacting with 66 and 86 proteins, respectively. Strikingly, Siglec-6 and Siglec-8 interacted with a large cluster of proteins involved in IgE and non-IgE-mediated MC activation, including the high affinity IgE receptor, stem cell factor (SCF) receptor KIT/CD117, IL-4 and IL-33 receptors, and intracellular kinases LYN and JAK1. Protein interaction networks revealed Siglec-6 and Siglec-8 had overlapping yet distinct MC functions, with a potentially broader regulatory role for Siglec-6. Indeed, Siglec-6 preferentially interacted with the mature form of KIT at the cell surface, and treatment with an anti-Siglec-6 antibody significantly inhibited SCF-mediated MC activation more in comparison to targeting Siglec-8. CONCLUSION These data demonstrate a central role for Siglec-6 and Siglec-8 in controlling MC activation through interactions with multiple activating receptors and key signaling molecules. Our findings suggest that Siglec-6 has a role distinct from that of Siglec-8 in regulating MC function and represents a distinct potential therapeutic target in mast cell-driven diseases.
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Affiliation(s)
| | | | - Alan Wong
- Allakos Inc., San Carlos, California, USA
| | - Gian Luca Negri
- LM Biostat Consulting Inc., Victoria, British Columbia, Canada
| | | | | | - John Leung
- Allakos Inc., San Carlos, California, USA
| | | | - Thuy Luu
- Allakos Inc., San Carlos, California, USA
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4
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McCord K, Wang C, Anhalt M, Poon WW, Gavin AL, Wu P, Macauley MS. Dissecting the Ability of Siglecs To Antagonize Fcγ Receptors. ACS CENTRAL SCIENCE 2024; 10:315-330. [PMID: 38435516 PMCID: PMC10906256 DOI: 10.1021/acscentsci.3c00969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 03/05/2024]
Abstract
Fcγ receptors (FcγRs) play key roles in the effector function of IgG, but their inappropriate activation plays a role in several disease etiologies. Therefore, it is critical to better understand how FcγRs are regulated. Numerous studies suggest that sialic acid-binding immunoglobulin-type lectins (Siglecs), a family of immunomodulatory receptors, modulate FcγR activity; however, it is unclear of the circumstances in which Siglecs can antagonize FcγRs and which Siglecs have this ability. Using liposomes displaying selective ligands to coengage FcγRs with a specific Siglec, we explore the ability of Siglec-3, Siglec-5, Siglec-7, and Siglec-9 to antagonize signaling downstream of FcγRs. We demonstrate that Siglec-3 and Siglec-9 can fully inhibit FcγR activation in U937 cells when coengaged with FcγRs. Cells expressing Siglec mutants reveal differential roles for the immunomodulatory tyrosine-based inhibitory motif (ITIM) and immunomodulatory tyrosine-based switch motif (ITSM) in this inhibition. Imaging flow cytometry enabled visualization of SHP-1 recruitment to Siglec-3 in an ITIM-dependent manner, while SHP-2 recruitment is more ITSM-dependent. Conversely, both cytosolic motifs of Siglec-9 contribute to SHP-1/2 recruitment. Siglec-7 poorly antagonizes FcγR activation for two reasons: masking by cis ligands and differences in its ITIM and ITSM. A chimera of the Siglec-3 extracellular domains and Siglec-5 cytosolic tail strongly inhibits FcγR when coengaged, providing evidence that Siglec-5 is more like Siglec-3 and Siglec-9 in its ability to antagonize FcγRs. Additionally, Siglec-3 and Siglec-9 inhibited FcγRs when coengaged by cells displaying ligands for both the Siglec and FcγRs. These results suggest a role for Siglecs in mediating FcγR inhibition in the context of an immunological synapse, which has important relevance to the effectiveness of immunotherapies.
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Affiliation(s)
- Kelli
A. McCord
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Chao Wang
- Department
of Molecular Medicine, Scripps Research
Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Mirjam Anhalt
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Wayne W. Poon
- Institute
for Memory Impairments and Neurological Disorders, University of California, Irvine, California 92617, United States
| | - Amanda L. Gavin
- Department
of Immunology and Microbiology, Scripps
Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Peng Wu
- Department
of Molecular Medicine, Scripps Research
Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Matthew S. Macauley
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
- Department
of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
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5
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Atxabal U, Nycholat C, Pröpster JM, Fernández A, Oyenarte I, Lenza MP, Franconetti A, Soares CO, Coelho H, Marcelo F, Schubert M, Paulson JC, Jiménez-Barbero J, Ereño-Orbea J. Unraveling Molecular Recognition of Glycan Ligands by Siglec-9 via NMR Spectroscopy and Molecular Dynamics Modeling. ACS Chem Biol 2024; 19:483-496. [PMID: 38321945 PMCID: PMC10877568 DOI: 10.1021/acschembio.3c00664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/09/2024] [Accepted: 01/16/2024] [Indexed: 02/08/2024]
Abstract
Human sialic-acid-binding immunoglobulin-like lectin-9 (Siglec-9) is a glycoimmune checkpoint receptor expressed on several immune cells. Binding of Siglec-9 to sialic acid containing glycans (sialoglycans) is well documented to modulate its functions as an inhibitory receptor. Here, we first assigned the amino acid backbone of the Siglec-9 V-set domain (Siglec-9d1), using well-established triple resonance three-dimensional nuclear magnetic resonance (NMR) methods. Then, we combined solution NMR and molecular dynamic simulation methods to decipher the molecular details of the interaction of Siglec-9 with the natural ligands α2,3 and α2,6 sialyl lactosamines (SLN), sialyl Lewis X (sLeX), and 6-O sulfated sLeX and with two synthetically modified sialoglycans that bind with high affinity. As expected, Neu5Ac is accommodated between the F and G β-strands at the canonical sialic acid binding site. Addition of a heteroaromatic scaffold 9N-5-(2-methylthiazol-4-yl)thiophene sulfonamide (MTTS) at the C9 position of Neu5Ac generates new interactions with the hydrophobic residues located at the G-G' loop and the N-terminal region of Siglec-9. Similarly, the addition of the aromatic substituent (5-N-(1-benzhydryl-1H-1,2,3-triazol-4-yl)methyl (BTC)) at the C5 position of Neu5Ac stabilizes the conformation of the long and flexible B'-C loop present in Siglec-9. These results expose the underlying mechanism responsible for the enhanced affinity and specificity for Siglec-9 for these two modified sialoglycans and sheds light on the rational design of the next generation of modified sialoglycans targeting Siglec-9.
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Affiliation(s)
- Unai Atxabal
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
| | - Corwin Nycholat
- Departments
of Molecular Medicine and Immunology and Microbiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Johannes M. Pröpster
- Institute
of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Andrea Fernández
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
| | - Iker Oyenarte
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
| | - Maria Pia Lenza
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
| | - Antonio Franconetti
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
| | - Cátia O. Soares
- Associate
Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Helena Coelho
- Associate
Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Filipa Marcelo
- Associate
Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School
of Science and Technology, Universidade
NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO,
Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Mario Schubert
- Institute
of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
- Department
of Biosciences and Molecular Biology, University
of Salzburg, Hellbrunnerstrasse
34, 5020 Salzburg, Austria
| | - James C. Paulson
- Departments
of Molecular Medicine and Immunology and Microbiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jesús Jiménez-Barbero
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
- Ikerbasque,
Basque Foundation for Science, Euskadi Pl., 5, 48009 Bilbao, Biscay, Spain
- Department
of Organic and Inorganic Chemistry, Faculty of Science and Technology, University of the Basque Country, EHU-UPV, 48940 Leioa, Bizkaia, Spain
- Centro
de Investigacion Biomedica en Red de Enfermedades Respiratorias, Av. Monforte de Lemos, 3-5, Pabellón
11, Planta 0, 28029 Madrid, Spain
| | - June Ereño-Orbea
- Chemical
Glycobiology Lab, Center for Cooperative Research in Biosciences (CIC
bioGUNE), Basque Research and Technology
Alliance (BRTA), 48160 Derio, Bizkaia, Spain
- Ikerbasque,
Basque Foundation for Science, Euskadi Pl., 5, 48009 Bilbao, Biscay, Spain
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6
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Metz M, Kolkhir P, Altrichter S, Siebenhaar F, Levi-Schaffer F, Youngblood BA, Church MK, Maurer M. Mast cell silencing: A novel therapeutic approach for urticaria and other mast cell-mediated diseases. Allergy 2024; 79:37-51. [PMID: 37605867 DOI: 10.1111/all.15850] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/21/2023] [Accepted: 07/29/2023] [Indexed: 08/23/2023]
Abstract
Chronic urticaria (CU) is a mast cell (MC)-dependent disease with limited therapeutic options. Current management strategies are directed at inhibiting IgE-mediated activation of MCs and antagonizing effects of released mediators. Due to the complexity and heterogeneity of CU and other MC diseases and mechanisms of MC activation-including multiple activating receptors and ligands, diverse signaling pathways, and a menagerie of mediators-strategies of MC depletion or MC silencing (i.e., inhibition of MC activation via binding of inhibitory receptors) have been developed to overcome limitations of singularly targeted agents. MC silencers, such as agonist monoclonal antibodies that engage inhibitory receptors (e.g., sialic acid-binding immunoglobulin-like lectin8 -[Siglec-8] [lirentelimab/AK002], Siglec-6 [AK006], and CD200R [LY3454738]), have reached preclinical and clinical stages of development. In this review, we (1) describe the role of MCs in the pathogenesis of CU, highlighting similarities with other MC diseases in disease mechanisms and response to treatment; (2) explore current therapeutic strategies, categorized by nonspecific immunosuppression, targeted inhibition of MC activation or mediators, and targeted modulation of MC activity; and (3) introduce the concept of MC silencing as an emerging strategy that could selectively block activation of MCs without eliciting or exacerbating on- or off-target, immunosuppressive adverse effects.
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Affiliation(s)
- Martin Metz
- Institute of Allergology, Charité-Universitätsmedizin Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin), Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, Berlin, Germany
| | - Pavel Kolkhir
- Institute of Allergology, Charité-Universitätsmedizin Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin), Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, Berlin, Germany
| | - Sabine Altrichter
- Institute of Allergology, Charité-Universitätsmedizin Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin), Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, Berlin, Germany
- Department of Dermatology and Venerology, Kepler University Hospital, Linz, Austria
| | - Frank Siebenhaar
- Institute of Allergology, Charité-Universitätsmedizin Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin), Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, Berlin, Germany
| | - Francesca Levi-Schaffer
- Pharmacology and Experimental Therapeutics Unit, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Martin K Church
- Institute of Allergology, Charité-Universitätsmedizin Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin), Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, Berlin, Germany
| | - Marcus Maurer
- Institute of Allergology, Charité-Universitätsmedizin Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin), Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, Berlin, Germany
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7
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Cao Y, Rische CH, Bochner BS, O’Sullivan JA. Interactions between Siglec-8 and endogenous sialylated cis ligands restrain cell death induction in human eosinophils and mast cells. Front Immunol 2023; 14:1283370. [PMID: 37928558 PMCID: PMC10623328 DOI: 10.3389/fimmu.2023.1283370] [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: 08/25/2023] [Accepted: 10/06/2023] [Indexed: 11/07/2023] Open
Abstract
Sialic acid-binding immunoglobulin-like lectin (Siglec)-8 is a sialoside-binding receptor expressed by eosinophils and mast cells that exhibits priming status- and cell type-dependent inhibitory activity. On eosinophils that have been primed with IL-5, GM-CSF, or IL-33, antibody ligation of Siglec-8 induces cell death through a pathway involving the β2 integrin-dependent generation of reactive oxygen species (ROS) via NADPH oxidase. In contrast, Siglec-8 engagement on mast cells inhibits cellular activation and mediator release but reportedly does not impact cell viability. The differences in responses between cytokine-primed and unprimed eosinophils, and between eosinophils and mast cells, to Siglec-8 ligation are not understood. We previously found that Siglec-8 binds to sialylated ligands present on the surface of the same cell (so-called cis ligands), preventing Siglec-8 ligand binding in trans. However, the functional relevance of these cis ligands has not been elucidated. We therefore explored the potential influence of cis ligands of Siglec-8 on both eosinophils and mast cells. De-sialylation using exogenous sialidase profoundly altered the consequences of Siglec-8 antibody engagement on both cell types, eliminating the need for cytokine priming of eosinophils to facilitate cell death and enabling Siglec-8-dependent mast cell death without impacting anti-Siglec-8 antibody binding. The cell death process licensed by de-sialylation resembled that characterized in IL-5-primed eosinophils, including CD11b upregulation, ROS production, and the activities of Syk, PI3K, and PLC. These results implicate cis ligands in restraining Siglec-8 function on eosinophils and mast cells and reveal a promising approach to the selective depletion of mast cells in patients with mast cell-mediated diseases.
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Affiliation(s)
- Yun Cao
- Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Clayton H. Rische
- Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Biomedical Engineering, Northwestern University McCormick School of Engineering, Evanston, IL, United States
| | - Bruce S. Bochner
- Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Jeremy A. O’Sullivan
- Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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8
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Miralda I, Samanas NB, Seo AJ, Foronda JS, Sachen J, Hui Y, Morrison SD, Oskeritzian CA, Piliponsky AM. Siglec-9 is an inhibitory receptor on human mast cells in vitro. J Allergy Clin Immunol 2023; 152:711-724.e14. [PMID: 37100120 PMCID: PMC10524464 DOI: 10.1016/j.jaci.2023.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/04/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023]
Abstract
BACKGROUND Mast cell activation is critical for the development of allergic diseases. Ligation of sialic acid-binding immunoglobin-like lectins (Siglecs), such as Siglec-6, -7, and -8 as well as CD33, have been shown to inhibit mast cell activation. Recent studies showed that human mast cells express Siglec-9, an inhibitory receptor also expressed by neutrophils, monocytes, macrophages, and dendritic cells. OBJECTIVE We aimed to characterize Siglec-9 expression and function in human mast cells in vitro. METHODS We assessed the expression of Siglec-9 and Siglec-9 ligands on human mast cell lines and human primary mast cells by real-time quantitative PCR, flow cytometry, and confocal microscopy. We used a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing approach to disrupt the SIGLEC9 gene. We evaluated Siglec-9 inhibitory activity on mast cell function by using native Siglec-9 ligands, glycophorin A (GlycA), and high-molecular-weight hyaluronic acid, a monoclonal antibody against Siglec-9, and coengagement of Siglec-9 with the high-affinity receptor for IgE (FcεRI). RESULTS Human mast cells express Siglec-9 and Siglec-9 ligands. SIGLEC9 gene disruption resulted in increased expression of activation markers at baseline and increased responsiveness to IgE-dependent and IgE-independent stimulation. Pretreatment with GlycA or high-molecular-weight hyaluronic acid followed by IgE-dependent or -independent stimulation had an inhibitory effect on mast cell degranulation. Coengagement of Siglec-9 with FcεRI in human mast cells resulted in reduced degranulation, arachidonic acid production, and chemokine release. CONCLUSIONS Siglec-9 and its ligands play an important role in limiting human mast cell activation in vitro.
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Affiliation(s)
- Irina Miralda
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, Wash
| | - Nyssa B Samanas
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, Wash
| | - Albert J Seo
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, Wash
| | - Jake S Foronda
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, Wash
| | - Josie Sachen
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, Wash
| | - Yvonne Hui
- University of South Carolina School of Medicine, Columbia, SC
| | - Shane D Morrison
- Department of Surgery, Division of Plastic Surgery, Seattle Children's Hospital, Seattle, Wash
| | | | - Adrian M Piliponsky
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, Wash; Department of Pediatrics, University of Washington School of Medicine, Seattle, Wash; Department of Pathology, University of Washington School of Medicine, Seattle, Wash; Department of Global Health, University of Washington School of Medicine, Seattle, Wash.
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9
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O'Sullivan JA, Youngblood BA, Schleimer RP, Bochner BS. Siglecs as potential targets of therapy in human mast cell- and/or eosinophil-associated diseases. Semin Immunol 2023; 69:101799. [PMID: 37413923 PMCID: PMC10528103 DOI: 10.1016/j.smim.2023.101799] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Siglecs (sialic acid-binding immunoglobulin-like lectins) are a family of vertebrate glycan-binding cell-surface proteins. The majority mediate cellular inhibitory activity once engaged by specific ligands or ligand-mimicking molecules. As a result, Siglec engagement is now of interest as a strategy to therapeutically dampen unwanted cellular responses. When considering allergic inflammation, human eosinophils and mast cells express overlapping but distinct patterns of Siglecs. For example, Siglec-6 is selectively and prominently expressed on mast cells while Siglec-8 is highly specific for both eosinophils and mast cells. This review will focus on a subset of Siglecs and their various endogenous or synthetic sialoside ligands that regulate eosinophil and mast cell function and survival. It will also summarize how certain Siglecs have become the focus of novel therapies for allergic and other eosinophil- and mast cell-related diseases.
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Affiliation(s)
- Jeremy A O'Sullivan
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | | | - Robert P Schleimer
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Bruce S Bochner
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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10
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Dispenza MC, Metcalfe DD, Olivera A. Research Advances in Mast Cell Biology and Their Translation Into Novel Therapies for Anaphylaxis. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2023; 11:2032-2042. [PMID: 36958519 PMCID: PMC10330051 DOI: 10.1016/j.jaip.2023.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/25/2023]
Abstract
Anaphylaxis is an acute, potentially life-threatening systemic allergic reaction for which there are no known reliable preventative therapies. Its primary cell mediator, the mast cell, has several pathophysiologic roles and functions in IgE-mediated reactions that continue to be poorly understood. Recent advances in the understanding of allergic mechanisms have identified novel targets for inhibiting mast cell function and activation. The prevention of anaphylaxis is within reach with new drugs that could modulate immune tolerance, mast cell proliferation and differentiation, and IgE regulation and production. Several US Food and Drug Administration-approved drugs for chronic urticaria, mastocytosis, and cancer are also being repurposed to prevent anaphylaxis. New therapeutics have not only shown promise in potential efficacy for preventing IgE-mediated reactions, but in some cases, they are able to inform us about mast cell mechanisms in vivo. This review summarizes the most recent advances in the treatment of anaphylaxis that have arisen from new pharmacologic tools and our current understanding of mast cell biology.
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Affiliation(s)
- Melanie C Dispenza
- Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md.
| | - Dean D Metcalfe
- Mast Cell Biology Section, Laboratory of Allergy Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Ana Olivera
- Mast Cell Biology Section, Laboratory of Allergy Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
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11
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Jin Z, Yan B, Zhang L, Wang C. Current and emerging biological therapies for Chronic rhinosinusitis with nasal polyps with type 2 inflammation. Expert Opin Investig Drugs 2023; 32:909-919. [PMID: 37855222 DOI: 10.1080/13543784.2023.2273502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
INTRODUCTION Chronic rhinosinusitis with nasal polyps (CRSwNP), especially CRSwNP with type 2 inflammation, remains the most difficult-to-treat subtype with high prevalence worldwide. The emergence of biologics has the potential to fulfill the unmet medical needs of patients with CRSwNP driven by type 2 inflammation. AREAS COVERED A current review of the literature was performed to overview current and emerging biological therapies in the treatment of CRSwNP. EXPERT OPINION In an era of precision medicine, biologics have been given expectations to provide customized therapies to patients with CRSwNP, particularly those with refractory CRSwNP. Large clinical trials and real-world experiences are both essential for the application of biologics. Moreover, to make biological therapy more tailored to patients, an in-depth understanding of the different mechanisms of biologics, further elucidating the relationship between biologics and conventional medical and surgical treatments, and identifying predictive biomarkers warrant thorough investigations.
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Affiliation(s)
- Zeyi Jin
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing Laboratory of Allergic Diseases, Beijing Key Laboratory of Nasal Diseases, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Capital Medical University, Beijing, China
- Research Unit of Diagnosis and Treatment of Chronic Nasal Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Bing Yan
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing Laboratory of Allergic Diseases, Beijing Key Laboratory of Nasal Diseases, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Capital Medical University, Beijing, China
- Research Unit of Diagnosis and Treatment of Chronic Nasal Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Luo Zhang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing Laboratory of Allergic Diseases, Beijing Key Laboratory of Nasal Diseases, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Capital Medical University, Beijing, China
- Research Unit of Diagnosis and Treatment of Chronic Nasal Diseases, Chinese Academy of Medical Sciences, Beijing, China
- Department of Allergy, Beijing TongRen Hospital, Capital Medical University, Beijing, China
| | - Chengshuo Wang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing Laboratory of Allergic Diseases, Beijing Key Laboratory of Nasal Diseases, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Capital Medical University, Beijing, China
- Research Unit of Diagnosis and Treatment of Chronic Nasal Diseases, Chinese Academy of Medical Sciences, Beijing, China
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12
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Sulsenti R, Jachetti E. Frenemies in the Microenvironment: Harnessing Mast Cells for Cancer Immunotherapy. Pharmaceutics 2023; 15:1692. [PMID: 37376140 DOI: 10.3390/pharmaceutics15061692] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Tumor development, progression, and resistance to therapies are influenced by the interactions between tumor cells and the surrounding microenvironment, comprising fibroblasts, immune cells, and extracellular matrix proteins. In this context, mast cells (MCs) have recently emerged as important players. Yet, their role is still controversial, as MCs can exert pro- or anti-tumor functions in different tumor types depending on their location within or around the tumor mass and their interaction with other components of the tumor microenvironment. In this review, we describe the main aspects of MC biology and the different contribution of MCs in promoting or inhibiting cancer growth. We then discuss possible therapeutic strategies aimed at targeting MCs for cancer immunotherapy, which include: (1) targeting c-Kit signaling; (2) stabilizing MC degranulation; (3) triggering activating/inhibiting receptors; (4) modulating MC recruitment; (5) harnessing MC mediators; (6) adoptive transferring of MCs. Such strategies should aim to either restrain or sustain MC activity according to specific contexts. Further investigation would allow us to better dissect the multifaceted roles of MCs in cancer and tailor novel approaches for an "MC-guided" personalized medicine to be used in combination with conventional anti-cancer therapies.
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Affiliation(s)
- Roberta Sulsenti
- Molecular Immunology Unit, Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
| | - Elena Jachetti
- Molecular Immunology Unit, Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
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13
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Thames AH, Moons SJ, Wong DA, Boltje TJ, Bochner BS, Jewett MC. GlycoCAP: A Cell-Free, Bacterial Glycosylation Platform for Building Clickable Azido-Sialoglycoproteins. ACS Synth Biol 2023; 12:1264-1274. [PMID: 37040463 PMCID: PMC10758250 DOI: 10.1021/acssynbio.3c00017] [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] [Indexed: 04/13/2023]
Abstract
Glycan-binding receptors known as lectins represent a class of potential therapeutic targets. Yet, the therapeutic potential of targeting lectins remains largely untapped due in part to limitations in tools for building glycan-based drugs. One group of desirable structures is proteins with noncanonical glycans. Cell-free protein synthesis systems have matured as a promising approach for making glycoproteins that may overcome current limitations and enable new glycoprotein medicines. Yet, this approach has not been applied to the construction of proteins with noncanonical glycans. To address this limitation, we develop a cell-free glycoprotein synthesis platform for building noncanonical glycans and, specifically, clickable azido-sialoglycoproteins (called GlycoCAP). The GlycoCAP platform uses an Escherichia coli-based cell-free protein synthesis system for the site-specific installation of noncanonical glycans onto proteins with a high degree of homogeneity and efficiency. As a model, we construct four noncanonical glycans onto a dust mite allergen (Der p 2): α2,3 C5-azido-sialyllactose, α2,3 C9-azido-sialyllactose, α2,6 C5-azido-sialyllactose, and α2,6 C9-azido-sialyllactose. Through a series of optimizations, we achieve more than 60% sialylation efficiency with a noncanonical azido-sialic acid. We then show that the azide click handle can be conjugated with a model fluorophore using both strain-promoted and copper-catalyzed click chemistry. We anticipate that GlycoCAP will facilitate the development and discovery of glycan-based drugs by granting access to a wider variety of possible noncanonical glycan structures and also provide an approach for functionalizing glycoproteins by click chemistry conjugation.
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Affiliation(s)
- Ariel Helms Thames
- Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
- Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Tech B486, Evanston, Illinois 60208, United States
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | - Sam J Moons
- Synvenio B.V., Mercator 3, Nijmegen 6525ED, The Netherlands
| | - Derek A Wong
- Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Tech B486, Evanston, Illinois 60208, United States
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, United States
| | - Thomas J Boltje
- Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen 6525AJ, The Netherlands
| | - Bruce S Bochner
- Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | - Michael C Jewett
- Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
- Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Tech B486, Evanston, Illinois 60208, United States
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208, United States
- Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, United States
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14
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Bochner BS, O'Sullivan JA, Chang AT, Youngblood BA. Siglecs in allergy and asthma. Mol Aspects Med 2023; 90:101104. [PMID: 35835621 PMCID: PMC10757266 DOI: 10.1016/j.mam.2022.101104] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 06/28/2022] [Accepted: 07/03/2022] [Indexed: 01/21/2023]
Abstract
The term "allergic diseases" encompasses several common, IgE-mediated conditions that range from being annoying to those that are life-threatening. Available treatments include active avoidance of the instigating allergen and the use of a variety of oral, inhaled, intranasal, intraocular and injected agents. While most individuals with allergies do well with existing therapies, there are still unmet therapeutic needs. Siglecs (sialic acid-binding, immunoglobulin-like lectins) are a family of single-pass transmembrane I-type lectins found on various subsets of cells, especially those of the immune system. All Siglecs have extracellular domains recognizing sialoside ligands, and most contain cytoplasmic domains with inhibitory signaling activity. This review focuses on Siglecs that likely play a role in regulating allergic and asthmatic responses, and how specific Siglecs, expressed on cells such as eosinophils and mast cells, are being targeted for therapeutic benefit.
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Affiliation(s)
- Bruce S Bochner
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Jeremy A O'Sullivan
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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15
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von Gunten S, Schneider C, Imamovic L, Gorochov G. Antibody diversity in IVIG: Therapeutic opportunities for novel immunotherapeutic drugs. Front Immunol 2023; 14:1166821. [PMID: 37063852 PMCID: PMC10090664 DOI: 10.3389/fimmu.2023.1166821] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/15/2023] [Indexed: 03/31/2023] Open
Abstract
Significant progress has been made in the elucidation of human antibody repertoires. Furthermore, non-canonical functions of antibodies have been identified that reach beyond classical functions linked to protection from pathogens. Polyclonal immunoglobulin preparations such as IVIG and SCIG represent the IgG repertoire of the donor population and will likely remain the cornerstone of antibody replacement therapy in immunodeficiencies. However, novel evidence suggests that pooled IgA might promote orthobiotic microbial colonization in gut dysbiosis linked to mucosal IgA immunodeficiency. Plasma-derived polyclonal IgG and IgA exhibit immunoregulatory effects by a diversity of different mechanisms, which have inspired the development of novel drugs. Here we highlight recent insights into IgG and IgA repertoires and discuss potential implications for polyclonal immunoglobulin therapy and inspired drugs.
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Affiliation(s)
- Stephan von Gunten
- Institute of Pharmacology, University of Bern, Bern, Switzerland
- *Correspondence: Stephan von Gunten,
| | | | - Lejla Imamovic
- Sorbonne Université, Inserm, Assistance Publique Hôpitaux de Paris (AP-HP), Pitié-Salpêtrière Hospital, Paris, France
| | - Guy Gorochov
- Sorbonne Université, Inserm, Assistance Publique Hôpitaux de Paris (AP-HP), Pitié-Salpêtrière Hospital, Paris, France
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16
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Rische CH, Thames AN, Krier-Burris RA, O’Sullivan JA, Bochner BS, Scott EA. Drug delivery targets and strategies to address mast cell diseases. Expert Opin Drug Deliv 2023; 20:205-222. [PMID: 36629456 PMCID: PMC9928520 DOI: 10.1080/17425247.2023.2166926] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/10/2022] [Accepted: 01/06/2023] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Current and developing mast cell therapeutics are reliant on small molecule drugs and biologics, but few are truly selective for mast cells. Most have cellular and disease-specific limitations that require innovation to overcome longstanding challenges to selectively targeting and modulating mast cell behavior. This review is designed to serve as a frame of reference for new approaches that utilize nanotechnology or combine different drugs to increase mast cell selectivity and therapeutic efficacy. AREAS COVERED Mast cell diseases include allergy and related conditions as well as malignancies. Here, we discuss the targets of existing and developing therapies used to treat these disease pathologies, classifying them into cell surface, intracellular, and extracellular categories. For each target discussed, we discuss drugs that are either the current standard of care, under development, or have indications for potential use. Finally, we discuss how novel technologies and tools can be used to take existing therapeutics to a new level of selectivity and potency against mast cells. EXPERT OPINION There are many broadly and very few selectively targeted therapeutics for mast cells in allergy and malignant disease. Combining existing targeting strategies with technology like nanoparticles will provide novel platforms to treat mast cell disease more selectively.
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Affiliation(s)
- Clayton H. Rische
- Northwestern University McCormick School of Engineering, Department of Biomedical Engineering, Evanston, IL, USA
- Northwestern University Feinberg School of Medicine, Division of Allergy and Immunology, Chicago, IL, USA
| | - Ariel N. Thames
- Northwestern University Feinberg School of Medicine, Division of Allergy and Immunology, Chicago, IL, USA
- Northwestern University McCormick School of Engineering, Department of Chemical and Biological Engineering, Evanston, IL, USA
| | - Rebecca A. Krier-Burris
- Northwestern University Feinberg School of Medicine, Division of Allergy and Immunology, Chicago, IL, USA
| | - Jeremy A. O’Sullivan
- Northwestern University Feinberg School of Medicine, Division of Allergy and Immunology, Chicago, IL, USA
| | - Bruce S. Bochner
- Northwestern University Feinberg School of Medicine, Division of Allergy and Immunology, Chicago, IL, USA
| | - Evan A. Scott
- Northwestern University McCormick School of Engineering, Department of Biomedical Engineering, Evanston, IL, USA
- Northwestern University Feinberg School of Medicine, Department of Microbiolgy-Immunology, Chicago, IL, USA
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17
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Lenza M, Atxabal U, Nycholat C, Oyenarte I, Franconetti A, Quintana JI, Delgado S, Núñez-Franco R, Garnica Marroquín CT, Coelho H, Unione L, Jiménez-Oses G, Marcelo F, Schubert M, Paulson JC, Jiménez-Barbero J, Ereño-Orbea J. Structures of the Inhibitory Receptor Siglec-8 in Complex with a High-Affinity Sialoside Analogue and a Therapeutic Antibody. JACS AU 2023; 3:204-215. [PMID: 36711084 PMCID: PMC9875244 DOI: 10.1021/jacsau.2c00592] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 06/18/2023]
Abstract
Human sialic acid binding immunoglobulin-like lectin-8 (Siglec-8) is an inhibitory receptor that triggers eosinophil apoptosis and can inhibit mast cell degranulation when engaged by specific monoclonal antibodies (mAbs) or sialylated ligands. Thus, Siglec-8 has emerged as a critical negative regulator of inflammatory responses in diverse diseases, such as allergic airway inflammation. Herein, we have deciphered the molecular recognition features of the interaction of Siglec-8 with the mAb lirentelimab (2C4, under clinical development) and with a sialoside mimetic with the potential to suppress mast cell degranulation. The three-dimensional structure of Siglec-8 and the fragment antigen binding (Fab) portion of the anti-Siglec-8 mAb 2C4, solved by X-ray crystallography, reveal that 2C4 binds close to the carbohydrate recognition domain (V-type Ig domain) on Siglec-8. We have also deduced the binding mode of a high-affinity analogue of its sialic acid ligand (9-N-napthylsufonimide-Neu5Ac, NSANeuAc) using a combination of NMR spectroscopy and X-ray crystallography. Our results show that the sialoside ring of NSANeuAc binds to the canonical sialyl binding pocket of the Siglec receptor family and that the high affinity arises from the accommodation of the NSA aromatic group in a nearby hydrophobic patch formed by the N-terminal tail and the unique G-G' loop. The results reveal the basis for the observed high affinity of this ligand and provide clues for the rational design of the next generation of Siglec-8 inhibitors. Additionally, the specific interactions between Siglec-8 and the N-linked glycans present on the high-affinity receptor FcεRIα have also been explored by NMR.
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Affiliation(s)
- Maria
Pia Lenza
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Unai Atxabal
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Corwin Nycholat
- Department
of Molecular Medicine and Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California92037, United States
| | - Iker Oyenarte
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Antonio Franconetti
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Jon Imanol Quintana
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Sandra Delgado
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Reyes Núñez-Franco
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | | | - Helena Coelho
- UCIBIO,
REQUIMTE, Departamento de Química, Faculdade de Ciências
e Tecnologia, Universidade de Nova de Lisboa, Caparica2829-516, Portugal
| | - Luca Unione
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
| | - Gonzalo Jiménez-Oses
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
- IKERBASQUE, Basque
Foundation for Science and Technology, Euskadi Plaza 5, Bilbao48009, Spain
| | - Filipa Marcelo
- UCIBIO,
REQUIMTE, Departamento de Química, Faculdade de Ciências
e Tecnologia, Universidade de Nova de Lisboa, Caparica2829-516, Portugal
| | - Mario Schubert
- Department
of Biosciences, University of Salzburg, Hellbrunnel Str. 34, Salzburg5020, Austria
| | - James C. Paulson
- Department
of Molecular Medicine and Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California92037, United States
| | - Jesús Jiménez-Barbero
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
- Department
of Organic Chemistry II, Faculty of Science and Technology, University of the Basque Country, Leioa48940, Spain
- IKERBASQUE, Basque
Foundation for Science and Technology, Euskadi Plaza 5, Bilbao48009, Spain
- Centro
de Investigacion Biomedica En Red de Enfermedades Respiratorias, Madrid28029, Spain
| | - June Ereño-Orbea
- CIC
bioGUNE, Bizkaia Technology Park, Building 800, Derio-Bizkaia48160, Spain
- IKERBASQUE, Basque
Foundation for Science and Technology, Euskadi Plaza 5, Bilbao48009, Spain
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18
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Liu G, Hao M, Zeng B, Liu M, Wang J, Sun S, Liu C, Huilian C. Sialic acid and food allergies: The link between nutrition and immunology. Crit Rev Food Sci Nutr 2022; 64:3880-3906. [PMID: 36369942 DOI: 10.1080/10408398.2022.2136620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Food allergies (FA), a major public health problem recognized by the World Health Organization, affect an estimated 3%-10% of adults and 8% of children worldwide. However, effective treatments for FA are still lacking. Recent advances in glycoimmunology have demonstrated the great potential of sialic acids (SAs) in the treatment of FA. SAs are a group of nine-carbon α-ketoacids usually linked to glycoproteins and glycolipids as terminal glycans. They play an essential role in modulating immune responses and may be an effective target for FA intervention. As exogenous food components, sialylated polysaccharides have anti-FA effects. In contrast, as endogenous components, SAs on immunoglobulin E and immune cell surfaces contribute to the pathogenesis of FA. Given the lack of comprehensive information on the effects of SAs on FA, we reviewed the roles of endogenous and exogenous SAs in the pathogenesis and treatment of FA. In addition, we considered the structure-function relationship of SAs to provide a theoretical basis for the development of SA-based FA treatments.
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Affiliation(s)
- Guirong Liu
- 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, China
| | - Mengzhen Hao
- 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, China
| | - Binghui Zeng
- 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, China
| | - Manman Liu
- 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, China
| | - Junjuan Wang
- 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, China
| | - Shanfeng Sun
- 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, China
| | - Changqi Liu
- School of Exercise and Nutritional Sciences, College of Health and Human Services, San Diego State University, California, United States of America
| | - Che Huilian
- 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, China
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19
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Discovery of an agonistic Siglec-6 antibody that inhibits and reduces human mast cells. Commun Biol 2022; 5:1226. [DOI: 10.1038/s42003-022-04207-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022] Open
Abstract
AbstractMast cells (MC) are key drivers of allergic and inflammatory diseases. Sialic acid-binding immunoglobulin-like lectin (Siglec)-6 is an immunoregulatory receptor found on MCs. While it is recognized that engaging Siglecs with antibodies mediates inhibition across immune cells, the mechanisms that govern this agonism are not understood. Here we generated Siglec-6 mAb clones (AK01 to AK18) to better understand Siglec-6-mediated agonism. Siglec-6 mAbs displayed epitope-dependent receptor internalization and inhibitory activity. We identified a Siglec-6 mAb (AK04) that required Fc-mediated interaction for receptor internalization and induced inhibition and antibody-dependent cellular phagocytosis against MCs. AK04-mediated MC inhibition required Siglec-6 immunoreceptor tyrosine-based inhibitory motif (ITIM) and ITIM-like domains and was associated with receptor cluster formation containing inhibitory phosphatases. Treatment of humanized mice with AK04 inhibited systemic anaphylaxis with a single dose and reduced MCs with chronic dosing. Our findings suggest Siglec-6 activity is epitope dependent and highlight an agonistic Siglec-6 mAb as a potential therapeutic approach in allergic disease.
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20
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Burchett JR, Dailey JM, Kee SA, Pryor DT, Kotha A, Kankaria RA, Straus DB, Ryan JJ. Targeting Mast Cells in Allergic Disease: Current Therapies and Drug Repurposing. Cells 2022; 11:3031. [PMID: 36230993 PMCID: PMC9564111 DOI: 10.3390/cells11193031] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/31/2022] [Accepted: 09/20/2022] [Indexed: 11/22/2022] Open
Abstract
The incidence of allergic disease has grown tremendously in the past three generations. While current treatments are effective for some, there is considerable unmet need. Mast cells are critical effectors of allergic inflammation. Their secreted mediators and the receptors for these mediators have long been the target of allergy therapy. Recent drugs have moved a step earlier in mast cell activation, blocking IgE, IL-4, and IL-13 interactions with their receptors. In this review, we summarize the latest therapies targeting mast cells as well as new drugs in clinical trials. In addition, we offer support for repurposing FDA-approved drugs to target mast cells in new ways. With a multitude of highly selective drugs available for cancer, autoimmunity, and metabolic disorders, drug repurposing offers optimism for the future of allergy therapy.
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Affiliation(s)
| | | | | | | | | | | | | | - John J. Ryan
- Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA
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21
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Robida PA, Rische CH, Morgenstern NBB, Janarthanam R, Cao Y, Krier-Burris RA, Korver W, Xu A, Luu T, Schanin J, Leung J, Rothenberg ME, Wechsler JB, Youngblood BA, Bochner BS, O’Sullivan JA. Functional and Phenotypic Characterization of Siglec-6 on Human Mast Cells. Cells 2022; 11:1138. [PMID: 35406705 PMCID: PMC8997871 DOI: 10.3390/cells11071138] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 12/12/2022] Open
Abstract
Mast cells are tissue-resident cells that contribute to allergic diseases, among others, due to excessive or inappropriate cellular activation and degranulation. Therapeutic approaches to modulate mast cell activation are urgently needed. Siglec-6 is an immunoreceptor tyrosine-based inhibitory motif (ITIM)-bearing receptor selectively expressed by mast cells, making it a promising target for therapeutic intervention. However, the effects of its engagement on mast cells are poorly defined. Siglec-6 expression and endocytosis on primary human mast cells and mast cell lines were assessed by flow cytometry. SIGLEC6 mRNA expression was examined by single-cell RNAseq in esophageal tissue biopsy samples. The ability of Siglec-6 engagement or co-engagement to prevent primary mast cell activation was determined based on assessments of mediator and cytokine secretion and degranulation markers. Siglec-6 was highly expressed by all mast cells examined, and the SIGLEC6 transcript was restricted to mast cells in esophageal biopsy samples. Siglec-6 endocytosis occurred with delayed kinetics relative to the related receptor Siglec-8. Co-crosslinking of Siglec-6 with FcεRIα enhanced the inhibition of mast cell activation and diminished downstream ERK1/2 and p38 phosphorylation. The selective, stable expression and potent inhibitory capacity of Siglec-6 on human mast cells are favorable for its use as a therapeutic target in mast cell-driven diseases.
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Affiliation(s)
- Piper A. Robida
- Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (P.A.R.); (Y.C.); (R.A.K.-B.); (J.B.W.); (B.S.B.)
| | - Clayton H. Rische
- McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA;
| | - Netali Ben-Baruch Morgenstern
- Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; (N.B.-B.M.); (M.E.R.)
| | - Rethavathi Janarthanam
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA;
| | - Yun Cao
- Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (P.A.R.); (Y.C.); (R.A.K.-B.); (J.B.W.); (B.S.B.)
| | - Rebecca A. Krier-Burris
- Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (P.A.R.); (Y.C.); (R.A.K.-B.); (J.B.W.); (B.S.B.)
| | - Wouter Korver
- Allakos, Inc., Redwood City, CA 94065, USA; (W.K.); (A.X.); (T.L.); (J.S.); (J.L.); (B.A.Y.)
| | - Alan Xu
- Allakos, Inc., Redwood City, CA 94065, USA; (W.K.); (A.X.); (T.L.); (J.S.); (J.L.); (B.A.Y.)
| | - Thuy Luu
- Allakos, Inc., Redwood City, CA 94065, USA; (W.K.); (A.X.); (T.L.); (J.S.); (J.L.); (B.A.Y.)
| | - Julia Schanin
- Allakos, Inc., Redwood City, CA 94065, USA; (W.K.); (A.X.); (T.L.); (J.S.); (J.L.); (B.A.Y.)
| | - John Leung
- Allakos, Inc., Redwood City, CA 94065, USA; (W.K.); (A.X.); (T.L.); (J.S.); (J.L.); (B.A.Y.)
| | - Marc E. Rothenberg
- Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; (N.B.-B.M.); (M.E.R.)
| | - Joshua B. Wechsler
- Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (P.A.R.); (Y.C.); (R.A.K.-B.); (J.B.W.); (B.S.B.)
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA;
| | - Bradford A. Youngblood
- Allakos, Inc., Redwood City, CA 94065, USA; (W.K.); (A.X.); (T.L.); (J.S.); (J.L.); (B.A.Y.)
| | - Bruce S. Bochner
- Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (P.A.R.); (Y.C.); (R.A.K.-B.); (J.B.W.); (B.S.B.)
| | - Jeremy A. O’Sullivan
- Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (P.A.R.); (Y.C.); (R.A.K.-B.); (J.B.W.); (B.S.B.)
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22
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Westermann S, Dietschmann A, Doehler D, Castiglione K, Bochner BS, Voehringer D, Radtke D. Siglec-F Promotes IL-33-Induced Cytokine Release from Bone Marrow-Derived Eosinophils Independently of the ITIM and ITIM-like Motif Phosphorylation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:732-744. [PMID: 34996839 DOI: 10.4049/jimmunol.2100184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 11/19/2021] [Indexed: 12/15/2022]
Abstract
Eosinophils are potent innate effector cells associated mainly with type 2 immune responses elicited by helminths and allergens. Their activity needs to be tightly controlled to prevent severe inflammation and tissue damage. Eosinophil degranulation and secretion of inflammatory effector molecules, including cytokines, chemokines, and lipid mediators, can be regulated by activating and inhibitory receptors on the cell surface. In this study, we investigated the modulation of proliferation, apoptosis, gene expression, and cytokine/chemokine secretion from IL-33-activated Mus musculus eosinophils on cross-linking of the transmembrane receptor Sialic acid-binding Ig-like lectin F (Siglec-F). Siglec-F contains an ITIM plus an ITIM-like motif in its intracellular tail and is mainly regarded as an inhibitory and apoptosis-inducing receptor. In vitro costimulation of bone marrow-derived eosinophils with anti-Siglec-F and IL-33 compared with treatment with either alone led to enhanced STAT6 phosphorylation, stronger induction of hypoxia/glycolysis-related proinflammatory genes, and elevated secretion of type 2 cytokines (IL-4, IL-13) and chemokines (CCL3, CCL4) with only minor effects on proliferation and apoptosis. Using a competitive mixed bone marrow chimera approach with wild-type and Siglec-F-deficient eosinophils, we observed no evidence for Siglec-F-regulated inhibition of Aspergillus fumigatus-elicited lung eosinophilia. Truncation of the Siglec-F cytoplasmic tail, but not mutation of the ITIM and ITIM-like motifs, ablated the effect of enhanced cytokine/chemokine secretion. This provides evidence for an ITIM phosphorylation-independent signaling pathway from the cytoplasmic tail of the Siglec-F receptor that enhances effector molecule release from activated eosinophils.
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Affiliation(s)
- Stefanie Westermann
- Department of Infection Biology, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Axel Dietschmann
- Department of Infection Biology, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Daniela Doehler
- Department of Infection Biology, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Kirstin Castiglione
- Department of Infection Biology, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Bruce S Bochner
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - David Voehringer
- Department of Infection Biology, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Daniel Radtke
- Department of Infection Biology, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany; and
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23
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Korver W, Wong A, Gebremeskel S, Negri GL, Schanin J, Chang K, Leung J, Benet Z, Luu T, Brock EC, Luehrsen K, Xu A, Youngblood BA. The Inhibitory Receptor Siglec-8 Interacts With FcεRI and Globally Inhibits Intracellular Signaling in Primary Mast Cells Upon Activation. Front Immunol 2022; 13:833728. [PMID: 35154156 PMCID: PMC8837033 DOI: 10.3389/fimmu.2022.833728] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 01/11/2022] [Indexed: 12/13/2022] Open
Abstract
Immunomodulation of mast cell (MC) activity is warranted in allergic and inflammatory diseases where MCs have a central role in pathogenesis. Targeting Siglec-8, an inhibitory receptor on MCs and eosinophils, has shown promising activity in preclinical and clinical studies. While the intracellular pathways that regulate Siglec-8 activity in eosinophils have been well studied, the signaling mechanisms that lead to MC inhibition have not been fully elucidated. Here, we evaluate the intracellular signaling pathways of Siglec-8-mediated inhibition in primary MCs using an anti-Siglec-8 monoclonal antibody (mAb). Phospho-proteomic profiling of FcεRI-activated MCs revealed Siglec-8 mAb-treatment globally inhibited proximal and downstream kinases, leading to attenuated MC activation and degranulation. In fact, Siglec-8 was found to directly interact with FcεRI signaling molecules. Siglec-8 inhibition was dependent on both cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that interact with the SH2 containing protein phosphatase Shp-2 upon Siglec-8 phosphorylation. Taken together, these data support a model in which Siglec-8 regulates proximal FcεRI-induced phosphorylation events through phosphatase recruitment and interaction with FcεRIγ, resulting in global inhibition of MCs upon Siglec-8 mAb engagement.
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Affiliation(s)
| | - Alan Wong
- Allakos Inc., Redwood City, CA, United States
| | | | | | | | | | - John Leung
- Allakos Inc., Redwood City, CA, United States
| | | | - Thuy Luu
- Allakos Inc., Redwood City, CA, United States
| | | | | | - Alan Xu
- Allakos Inc., Redwood City, CA, United States
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24
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Smeekens JM, Kulis MD. Mouse Models of Food Allergy in the Pursuit of Novel Treatment Modalities. FRONTIERS IN ALLERGY 2021; 2:810067. [PMID: 35387036 PMCID: PMC8974753 DOI: 10.3389/falgy.2021.810067] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
The prevalence of IgE-mediated food allergies has increased dramatically in the past three decades, now affecting up to 10% of the US population. IgE-mediated food allergy is an immunologic disease, involving a variety of cells, including B and T cells, mast cells, basophils, ILC2s, and epithelial cells. Mouse models of food allergy mimic the overall immunologic processes known to exist in humans. Due to the limitations of invasive sampling of human tissue and the similarities of the human and mouse immune systems, comprehensive pathogenesis studies of food allergy have been performed in mouse models. Mouse models have been effective in elucidating the roles of non-oral routes of sensitization and identifying key cells and molecules involved in allergic sensitization. Furthermore, the development of novel therapeutic approaches for food allergy has been accelerated through the use of pre-clinical mouse models. Despite the groundbreaking findings stemming from research in mice, there are continued efforts to improve the translational utility of these models. Here, we highlight the achievements in understanding food allergy development and efforts to bring novel treatment approaches into clinical trials.
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Affiliation(s)
- Johanna M. Smeekens
- Division of Allergy and Immunology, Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC, United States
- University of North Carolina Food Allergy Initiative, Chapel Hill, NC, United States
- *Correspondence: Johanna M. Smeekens
| | - Michael D. Kulis
- Division of Allergy and Immunology, Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC, United States
- University of North Carolina Food Allergy Initiative, Chapel Hill, NC, United States
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25
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Cao X, Cordova AF, Li L. Therapeutic Interventions Targeting Innate Immune Receptors: A Balancing Act. Chem Rev 2021; 122:3414-3458. [PMID: 34870969 DOI: 10.1021/acs.chemrev.1c00716] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The innate immune system is an organism's first line of defense against an onslaught of internal and external threats. The downstream adaptive immune system has been a popular target for therapeutic intervention, while there is a relative paucity of therapeutics targeting the innate immune system. However, the innate immune system plays a critical role in many human diseases, such as microbial infection, cancer, and autoimmunity, highlighting the need for ongoing therapeutic research. In this review, we discuss the major innate immune pathways and detail the molecular strategies underpinning successful therapeutics targeting each pathway as well as previous and ongoing efforts. We will also discuss any recent discoveries that could inform the development of novel therapeutic strategies. As our understanding of the innate immune system continues to develop, we envision that therapies harnessing the power of the innate immune system will become the mainstay of treatment for a wide variety of human diseases.
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26
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Carroll DJ, Cao Y, Bochner BS, O’Sullivan JA. Siglec-8 Signals Through a Non-Canonical Pathway to Cause Human Eosinophil Death In Vitro. Front Immunol 2021; 12:737988. [PMID: 34721399 PMCID: PMC8549629 DOI: 10.3389/fimmu.2021.737988] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/14/2021] [Indexed: 12/19/2022] Open
Abstract
Sialic acid-binding immunoglobulin-like lectin (Siglec)-8 is a glycan-binding receptor bearing immunoreceptor tyrosine-based inhibitory and switch motifs (ITIM and ITSM, respectively) that is selectively expressed on eosinophils, mast cells, and, to a lesser extent, basophils. Previous work has shown that engagement of Siglec-8 on IL-5-primed eosinophils causes cell death via CD11b/CD18 integrin-mediated adhesion and NADPH oxidase activity and identified signaling molecules linking adhesion, reactive oxygen species (ROS) production, and cell death. However, the proximal signaling cascade activated directly by Siglec-8 engagement has remained elusive. Most members of the Siglec family possess similar cytoplasmic signaling motifs and recruit the protein tyrosine phosphatases SHP-1/2, consistent with ITIM-mediated signaling, to dampen cellular activation. However, the dependence of Siglec-8 function in eosinophils on these phosphatases has not been studied. Using Siglec-8 antibody engagement and pharmacological inhibition in conjunction with assays to measure cell-surface upregulation and conformational activation of CD11b integrin, ROS production, and cell death, we sought to identify molecules involved in Siglec-8 signaling and determine the stage of the process in which each molecule plays a role. We demonstrate here that the enzymatic activities of Src family kinases (SFKs), Syk, SHIP1, PAK1, MEK1, ERK1/2, PLC, PKC, acid sphingomyelinase/ceramidase, and Btk are all necessary for Siglec-8-induced eosinophil cell death, with no apparent role for SHP-1/2, SHIP2, or c-Raf. While most of these signaling molecules are necessary for Siglec-8-induced upregulation of CD11b integrin at the eosinophil cell surface, Btk is phosphorylated and activated later in the signaling cascade and is instead necessary for CD11b activation. In contrast, SFKs and ERK1/2 are phosphorylated far earlier in the process, consistent with their role in augmenting cell-surface levels of CD11b. In addition, pretreatment of eosinophils with latrunculin B or jasplakinolide revealed that actin filament disassembly is necessary and sufficient for surface CD11b integrin upregulation and that actin polymerization is necessary for downstream ROS production. These results show that Siglec-8 signals through an unanticipated set of signaling molecules in IL-5-primed eosinophils to induce cell death and challenges the expectation that ITIM-bearing Siglecs signal through inhibitory pathways involving protein tyrosine phosphatases to achieve their downstream functions.
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Affiliation(s)
| | | | | | - Jeremy A. O’Sullivan
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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27
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Camilleri AE, Nag S, Russo AR, Stiles KM, Crystal RG, Pagovich OE. Gene therapy for a murine model of eosinophilic esophagitis. Allergy 2021; 76:2740-2752. [PMID: 33748982 DOI: 10.1111/all.14822] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/05/2021] [Accepted: 01/15/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Eosinophils are specialized granulocytic effector cells that store and release highly active mediators used in immune defense. Eosinophils are also implicated in the pathogenesis of allergic disorders, including eosinophilic esophagitis (EoE), a chronic disorder characterized by infiltration of eosinophils into the esophagus and release of mediators that damage tissue, resulting in gastrointestinal morbidity, food impaction, and dysphagia. Treatment with elimination diets and/or topical corticosteroid therapy slow disease progression, but are complicated by adverse effects, limited compliance, and loss of response to therapy. We hypothesized that a single administration of an adeno-associated virus (AAV) coding for an anti-eosinophil monoclonal antibody that induces eosinophil clearance (anti-Siglec-F) would treat on a persistent basis a murine model of EoE. METHODS A mouse model of peanut-induced EoE that mimics the human disease was established by sensitization and challenge with peanut extract. After challenge, these mice exhibited an EoE phenotype demonstrated by elevated levels of blood eosinophils, infiltration of eosinophils in the esophagus with associated esophageal remodeling and food impaction. RESULTS The mice were treated with a single intravenous administration (1011 genome copies) of AAVrh.10mAnti-Eos, a serotype rh.10 AAV vector coding for an anti-Siglec-F monoclonal antibody. Vector administration resulted in persistent, high levels of anti-Siglec-F antibody expression. Administration of AAVrh.10mAnti-Eos to the mouse model of EoE reduced blood (P < 0.02) and esophageal eosinophil numbers (P < 0.002) protected from esophageal tissue remodeling and minimized food impaction. CONCLUSION These results suggest that a single treatment with AAVrh.10mAnti-Eos has the potential to provide persistent therapeutic benefit to patients with EoE.
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Affiliation(s)
- Anna E. Camilleri
- Department of Genetic Medicine Weill Cornell Medical College New York NY USA
| | - Saparja Nag
- Department of Genetic Medicine Weill Cornell Medical College New York NY USA
| | - Anthony R. Russo
- Department of Genetic Medicine Weill Cornell Medical College New York NY USA
| | - Katie M. Stiles
- Department of Genetic Medicine Weill Cornell Medical College New York NY USA
| | - Ronald G. Crystal
- Department of Genetic Medicine Weill Cornell Medical College New York NY USA
| | - Odelya E. Pagovich
- Department of Genetic Medicine Weill Cornell Medical College New York NY USA
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28
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Tontini C, Bulfone-Paus S. Novel Approaches in the Inhibition of IgE-Induced Mast Cell Reactivity in Food Allergy. Front Immunol 2021; 12:613461. [PMID: 34456900 PMCID: PMC8387944 DOI: 10.3389/fimmu.2021.613461] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 06/23/2021] [Indexed: 01/21/2023] Open
Abstract
Allergy is an IgE-dependent type-I hypersensitivity reaction that can lead to life-threatening systemic symptoms such as anaphylaxis. In the pathogenesis of the allergic response, the common upstream event is the binding of allergens to specific IgE, inducing cross-linking of the high-affinity FcεRI on mast cells, triggering cellular degranulation and the release of histamine, proteases, lipids mediators, cytokines and chemokines with inflammatory activity. A number of novel therapeutic options to curb mast cell activation are in the pipeline for the treatment of severe allergies. In addition to anti-IgE therapy and allergen-specific immunotherapy, monoclonal antibodies targeted against several key Th2/alarmin cytokines (i.e. IL-4Rα, IL-33, TSLP), active modification of allergen-specific IgE (i.e. inhibitory compounds, monoclonal antibodies, de-sialylation), engagement of inhibitory receptors on mast cells and allergen-specific adjuvant vaccines, are new promising options to inhibit the uncontrolled release of mast cell mediators upon allergen exposure. In this review, we critically discuss the novel approaches targeting mast cells limiting allergic responses and the immunological mechanisms involved, with special interest on food allergy treatment.
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Affiliation(s)
- Chiara Tontini
- Lydia Becker Institute for Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Silvia Bulfone-Paus
- Lydia Becker Institute for Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
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29
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Lafleur MA, Werner J, Fort M, Lobenhofer EK, Balazs M, Goyos A. MRGPRX2 activation as a rapid, high-throughput mechanistic-based approach for detecting peptide-mediated human mast cell degranulation liabilities. J Immunotoxicol 2021; 17:110-121. [PMID: 32525431 DOI: 10.1080/1547691x.2020.1757793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mast cells play key roles in allergy, anaphylaxis/anaphylactoid reactions, and defense against pathogens/toxins. These cells contain cytoplasmic granules with a wide spectrum of pleotropic mediators that are released upon activation. While mast cell degranulation (MCD) occurs upon clustering of the IgE receptor bound to IgE and antigen, MCD is also triggered through non-IgE-mediated mechanisms, one of which is via Mas-related G protein-coupled receptor X2 (MRGPRX2). MRGPRX2 can be activated by many basic biogenic amines and peptides. Consequently, MRGPRX2-mediated MCD is an important potential safety liability for peptide therapeutics. To facilitate peptide screening for this liability in early preclinical drug development, a rapid, high-throughput engineered CHO-K1 cell-based MRGPRX2 activation assay was evaluated and compared to histamine release in CD34+ stem cell-derived mature human mast cells as a reference assay, using 30 positive control and 29 negative control peptides for MCD. Both G protein-dependent (Ca2+ endpoint) and -independent (β-arrestin endpoint) pathways were assessed in the MRGPRX2 activation assay. The MRGPRX2 activation assay had a sensitivity of 100% for both Ca2+ and β-arrestin endpoints and a specificity of 93% (β-arrestin endpoint) and 83% (Ca2+ endpoint) compared to histamine release in CD34+ stem cell-derived mature human mast cells. These findings suggest that assessing MRGPRX2 activation in an engineered cell model can provide value as a rapid, high-throughput, economical mechanism-based screening tool for early MCD hazard identification during preclinical safety evaluation of peptide-based therapeutics.
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Affiliation(s)
- Marc A Lafleur
- Translational Safety & Bioanalytical Sciences, Amgen Research, Amgen Inc., Thousand Oaks, CA, USA
| | - Jonathan Werner
- Translational Safety & Bioanalytical Sciences, Amgen Research, Amgen Inc., Thousand Oaks, CA, USA
| | - Madeline Fort
- Translational Safety & Bioanalytical Sciences, Amgen Research, Amgen Inc., Thousand Oaks, CA, USA
| | - Edward K Lobenhofer
- Translational Safety & Bioanalytical Sciences, Amgen Research, Amgen Inc., Thousand Oaks, CA, USA
| | - Mercedesz Balazs
- Translational Safety & Bioanalytical Sciences, Amgen Research, Amgen, Inc., South San Francisco, CA, USA
| | - Ana Goyos
- Translational Safety & Bioanalytical Sciences, Amgen Research, Amgen, Inc., South San Francisco, CA, USA
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30
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Gotlib J, George TI, Carter MC, Austen KF, Bochner B, Dwyer DF, Lyons JJ, Hamilton MJ, Butterfield J, Bonadonna P, Weiler C, Galli SJ, Schwartz LB, Elberink HO, Maitland A, Theoharides T, Ustun C, Horny HP, Orfao A, Deininger M, Radia D, Jawhar M, Kluin-Nelemans H, Metcalfe DD, Arock M, Sperr WR, Valent P, Castells M, Akin C. Proceedings from the Inaugural American Initiative in Mast Cell Diseases (AIM) Investigator Conference. J Allergy Clin Immunol 2021; 147:2043-2052. [PMID: 33745886 PMCID: PMC9521380 DOI: 10.1016/j.jaci.2021.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/28/2021] [Accepted: 03/05/2021] [Indexed: 02/07/2023]
Abstract
The American Initiative in Mast Cell Diseases (AIM) held its inaugural investigator conference at Stanford University School of Medicine in May 2019. The overarching goal of this meeting was to establish a Pan-American organization of physicians and scientists with multidisciplinary expertise in mast cell disease. To serve this unmet need, AIM envisions a network where basic, translational, and clinical researchers could establish collaborations with both academia and biopharma to support the development of new diagnostic methods, enhanced understanding of the biology of mast cells in human health and disease, and the testing of novel therapies. In these AIM proceedings, we highlight selected topics relevant to mast cell biology and provide updates regarding the recently described hereditary alpha-tryptasemia. In addition, we discuss the evaluation and treatment of mast cell activation (syndromes), allergy and anaphylaxis in mast cell disorders, and the clinical and biologic heterogeneity of the more indolent forms of mastocytosis. Because mast cell disorders are relatively rare, AIM hopes to achieve a coordination of scientific efforts not only in the Americas but also in Europe by collaborating with the well-established European Competence Network on Mastocytosis.
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Affiliation(s)
- Jason Gotlib
- Division of Hematology, Stanford University School of Medicine/Stanford Cancer Institute, Stanford, Calif.
| | - Tracy I George
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Melody C Carter
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - K Frank Austen
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital, Boston, Mass
| | - Bruce Bochner
- Department of Medicine, Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Ill
| | - Daniel F Dwyer
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital, Boston, Mass
| | - Jonathan J Lyons
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Matthew J Hamilton
- Division of Gastroenterology, Hepatology and Endoscopy. Brigham and Women's Hospital, Harvard Medical School, Boston, Mass
| | | | | | | | - Stephen J Galli
- Department of Pathology, Stanford University School of Medicine, Stanford, Calif; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, Calif
| | - Lawrence B Schwartz
- Department of Internal Medicine, Division of Rheumatology, Allergy and Immunology, Virginia Commonwealth University, Richmond, Va
| | - Hanneke Oude Elberink
- Internal Medicine, Section Allergology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Anne Maitland
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Celalettin Ustun
- Division of Hematology, Oncology and Cellular Therapy, Department of Medicine, Rush University, Chicago, Ill
| | - Hans-Peter Horny
- Institute of Pathology, Ludwig-Maximilian-University, Munich, Germany
| | - Alberto Orfao
- Servicio Central de Citometria, Centro de Investigacion del Cancer (IBMCC, CSIC/USAL), IBSAL, CIBERONC and Department of Medicine, University of Salamanca, Salamanca, Germany
| | - Michael Deininger
- Division of Hematology and Hematologic Malignancies, The University of Utah, and Huntsman Cancer Institute, Salt Lake City, Utah
| | - Deepti Radia
- Department of Clinical Haematology, Guys and St Thomas' NHS Hospitals, London, United Kingdom
| | - Mohamad Jawhar
- University Hospital Mannheim, Heidelberg University, Mannheim, Germany
| | - Hanneke Kluin-Nelemans
- Department of Haematology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Dean D Metcalfe
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Michel Arock
- Laboratory of Haematology, Pitié-Salpêtrière Hospital, Paris, France
| | - Wolfgang R Sperr
- Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute for Hematology and Oncology, Medical University of Vienna, Vienna, Austria
| | - Peter Valent
- Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute for Hematology and Oncology, Medical University of Vienna, Vienna, Austria
| | - Mariana Castells
- Brigham and Women's Hospital, Division of Allergy and Clinical Immunology, Boston, Mass; Harvard Medical School, Boston, Mass
| | - Cem Akin
- Division of Allergy and Immunology, University of Michigan, Ann Arbor, Mich
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Abstract
A dense and diverse array of glycans on glycoproteins and glycolipids decorate all cell surfaces. In vertebrates, many of these carry sialic acid, in a variety of linkages and glycan contexts, as their outermost sugar moiety. Among their functions, glycans engage complementary glycan binding proteins (lectins) to regulate cell physiology. Among the glycan binding proteins are the Siglecs, sialic acid binding immunoglobulin-like lectins. In humans, there are 14 Siglecs, most of which are expressed on overlapping subsets of immune system cells. Each Siglec engages distinct, endogenous sialylated glycans that initiate signaling programs and regulate cellular responses. Here, we explore the emerging science of Siglec ligands, including endogenous sialoglycoproteins and glycolipids and synthetic sialomimetics. Knowledge in this field promises to reveal new molecular pathways controlling cell physiology and new opportunities for therapeutic intervention.
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32
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Duan S, Arlian BM, Nycholat CM, Wei Y, Tateno H, Smith SA, Macauley MS, Zhu Z, Bochner BS, Paulson JC. Nanoparticles Displaying Allergen and Siglec-8 Ligands Suppress IgE-FcεRI-Mediated Anaphylaxis and Desensitize Mast Cells to Subsequent Antigen Challenge. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 206:2290-2300. [PMID: 33911007 PMCID: PMC8113104 DOI: 10.4049/jimmunol.1901212] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/15/2021] [Indexed: 01/01/2023]
Abstract
Siglec-8 is an inhibitory receptor expressed on eosinophils and mast cells. In this study, we took advantage of a novel Siglec-8 transgenic mouse model to assess the impact of modulating IgE-dependent mast cell degranulation and anaphylaxis using a liposomal platform to display an allergen with or without a synthetic glycan ligand for Siglec-8 (Sig8L). The hypothesis is that recruitment of Siglec-8 to the IgE-FcεRI receptor complex will inhibit allergen-induced mast cell degranulation. Codisplay of both allergen and Sig8L on liposomes profoundly suppresses IgE-mediated degranulation of mouse bone marrow-derived mast cells or rat basophilic leukemia cells expressing Siglec-8. In contrast, liposomes displaying only Sig8L have no significant suppression of antigenic liposome-induced degranulation, demonstrating that the inhibitory activity by Siglec-8 occurs only when Ag and Sig8L are on the same particle. In mouse models of anaphylaxis, display of Sig8L on antigenic liposomes completely suppresses IgE-mediated anaphylaxis in transgenic mice with mast cells expressing Siglec-8 but has no protection in mice that do not express Siglec-8. Furthermore, mice protected from anaphylaxis remain desensitized to subsequent allergen challenge because of loss of Ag-specific IgE from the cell surface and accelerated clearance of IgE from the blood. Thus, although expression of human Siglec-8 on murine mast cells does not by itself modulate IgE-FcεRI-mediated cell activation, the enforced recruitment of Siglec-8 to the FcεRI receptor by Sig8L-decorated antigenic liposomes results in inhibition of degranulation and desensitization to subsequent Ag exposure.
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MESH Headings
- Allergens/administration & dosage
- Anaphylaxis/drug therapy
- Anaphylaxis/genetics
- Anaphylaxis/immunology
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Cell Degranulation/drug effects
- Cell Degranulation/genetics
- Cell Degranulation/immunology
- Cell Line, Tumor
- Desensitization, Immunologic/methods
- Disease Models, Animal
- Drug Delivery Systems/methods
- Humans
- Immunoglobulin E/metabolism
- Lectins/genetics
- Lectins/metabolism
- Ligands
- Liposomes
- Mast Cells/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Nanoparticles/chemistry
- Polysaccharides/administration & dosage
- Polysaccharides/metabolism
- Rats
- Receptors, IgE/genetics
- Receptors, IgE/metabolism
- Treatment Outcome
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Affiliation(s)
- Shiteng Duan
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - Britni M Arlian
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - Corwin M Nycholat
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - Yadong Wei
- Department of Pharmacology and Molecular Science, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Hiroaki Tateno
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - Scott A Smith
- Department of Medicine, and Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN
| | - Matthew S Macauley
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
| | - Zhou Zhu
- Department of Pediatrics, Brown University Alpert Medical School, Providence, RI
| | - Bruce S Bochner
- Department of Medicine, Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - James C Paulson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA
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33
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Gebremeskel S, Schanin J, Coyle KM, Butuci M, Luu T, Brock EC, Xu A, Wong A, Leung J, Korver W, Morin RD, Schleimer RP, Bochner BS, Youngblood BA. Mast Cell and Eosinophil Activation Are Associated With COVID-19 and TLR-Mediated Viral Inflammation: Implications for an Anti-Siglec-8 Antibody. Front Immunol 2021; 12:650331. [PMID: 33777047 PMCID: PMC7988091 DOI: 10.3389/fimmu.2021.650331] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/18/2021] [Indexed: 12/11/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection represents a global health crisis. Immune cell activation via pattern recognition receptors has been implicated as a driver of the hyperinflammatory response seen in COVID-19. However, our understanding of the specific immune responses to SARS-CoV-2 remains limited. Mast cells (MCs) and eosinophils are innate immune cells that play pathogenic roles in many inflammatory responses. Here we report MC-derived proteases and eosinophil-associated mediators are elevated in COVID-19 patient sera and lung tissues. Stimulation of viral-sensing toll-like receptors in vitro and administration of synthetic viral RNA in vivo induced features of hyperinflammation, including cytokine elevation, immune cell airway infiltration, and MC-protease production—effects suppressed by an anti-Siglec-8 monoclonal antibody which selectively inhibits MCs and depletes eosinophils. Similarly, anti-Siglec-8 treatment reduced disease severity and airway inflammation in a respiratory viral infection model. These results suggest that MC and eosinophil activation are associated with COVID-19 inflammation and anti-Siglec-8 antibodies are a potential therapeutic approach for attenuating excessive inflammation during viral infections.
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Affiliation(s)
| | | | - Krysta M Coyle
- Department of Molecular Biology and Biochemistry, Research Centre, Simon Fraser University, Vancouver, BC, Canada
| | | | - Thuy Luu
- Allakos Inc., Redwood City, CA, United States
| | | | - Alan Xu
- Allakos Inc., Redwood City, CA, United States
| | - Alan Wong
- Allakos Inc., Redwood City, CA, United States
| | - John Leung
- Allakos Inc., Redwood City, CA, United States
| | | | - Ryan D Morin
- Department of Molecular Biology and Biochemistry, Research Centre, Simon Fraser University, Vancouver, BC, Canada
| | - Robert P Schleimer
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Bruce S Bochner
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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34
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Schneider AL, Schleimer RP, Tan BK. Targetable pathogenic mechanisms in nasal polyposis. Int Forum Allergy Rhinol 2021; 11:1220-1234. [PMID: 33660425 DOI: 10.1002/alr.22787] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 12/13/2022]
Abstract
Chronic rhinosinusitis with nasal polyps (CRSwNP) represents a challenging disease entity with significant rates of recurrence following appropriate medical and surgical therapy. Recent approval of targeted biologics in CRSwNP compels deeper understanding of underlying disease pathophysiology. Both of the approved biologics for CRSwNP modulate the type 2 inflammatory pathway, and the majority of drugs in the clinical trials pathway are similarly targeted. However, there remain multiple other pathogenic mechanisms relevant to CRSwNP for which targeted therapeutics already exist in other inflammatory diseases that have not been studied directly. In this article we summarize pathogenic mechanisms of interest in CRSwNP and discuss the results of ongoing clinical studies of targeted therapeutics in CRSwNP and other related human inflammatory diseases.
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Affiliation(s)
| | - Robert P Schleimer
- Department of Otolaryngology, Head and Neck Surgery, Chicago, Illinois, USA.,Division of Allergy-Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Bruce K Tan
- Department of Otolaryngology, Head and Neck Surgery, Chicago, Illinois, USA.,Division of Allergy-Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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35
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Smith BAH, Bertozzi CR. The clinical impact of glycobiology: targeting selectins, Siglecs and mammalian glycans. Nat Rev Drug Discov 2021; 20:217-243. [PMID: 33462432 PMCID: PMC7812346 DOI: 10.1038/s41573-020-00093-1] [Citation(s) in RCA: 217] [Impact Index Per Article: 72.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2020] [Indexed: 01/31/2023]
Abstract
Carbohydrates - namely glycans - decorate every cell in the human body and most secreted proteins. Advances in genomics, glycoproteomics and tools from chemical biology have made glycobiology more tractable and understandable. Dysregulated glycosylation plays a major role in disease processes from immune evasion to cognition, sparking research that aims to target glycans for therapeutic benefit. The field is now poised for a boom in drug development. As a harbinger of this activity, glycobiology has already produced several drugs that have improved human health or are currently being translated to the clinic. Focusing on three areas - selectins, Siglecs and glycan-targeted antibodies - this Review aims to tell the stories behind therapies inspired by glycans and to outline how the lessons learned from these approaches are paving the way for future glycobiology-focused therapeutics.
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Affiliation(s)
- Benjamin A H Smith
- Department of Chemical & Systems Biology and ChEM-H, Stanford School of Medicine, Stanford, CA, USA
| | - Carolyn R Bertozzi
- Department of Chemical & Systems Biology and ChEM-H, Stanford School of Medicine, Stanford, CA, USA.
- Department of Chemistry, Stanford University, Stanford, CA, USA.
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
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36
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Abstract
Introduction: Targeting immune checkpoints with antibodies has significantly improved the outcome of cancer patients, but only few patients have long-term benefits from currently used PD-1/PD-L1 and CTLA-4 inhibitors. New approaches are needed to increase the number of patients going into long-term remission after cancer immunotherapy. Glyco-immune checkpoints are new targets for cancer immunotherapy. They are defined as immune-modulatory pathways including interactions of glycans with glycan-binding proteins or lectins. The most prominent pathway is the sialoglycan-Siglec axis and inhibitors of this axis are already successfully tested in early clinical trials.Area covered: Here, we summarize the current knowledge on glyco-immune checkpoints with a focus on the sialoglycan-Siglec axis. We also provide an overview on current approaches to clinically target glyco-immune checkpoints and give an outlook for the further clinical development of glyco-immune checkpoint targeting agents.Expert opinion: Glyco-immune checkpoints are interesting new targets to improve cancer immunotherapy. Antibodies targeting the sialoglycan-Siglec axis are already in clinical development. Other approaches with higher risk of toxicity including tumor-targeted sialidases are in late stage pre-clinical development. Despite the challenges, targeting of glyco-immune checkpoints could lead to the development of a new class of drugs providing improved anti-cancer immunity and eventually benefit cancer patients.
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Affiliation(s)
- Michela Manni
- Laboratory for Cancer Immunotherapy, Department of Biomedicine, University of Basel, and Division of Medical Oncology, University Hospital Basel, Basel, Switzerland
| | - Heinz Läubli
- Laboratory for Cancer Immunotherapy, Department of Biomedicine, University of Basel, and Division of Medical Oncology, University Hospital Basel, Basel, Switzerland
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37
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Dispenza MC, Bochner BS, MacGlashan DW. Targeting the FcεRI Pathway as a Potential Strategy to Prevent Food-Induced Anaphylaxis. Front Immunol 2021; 11:614402. [PMID: 33391286 PMCID: PMC7773654 DOI: 10.3389/fimmu.2020.614402] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/16/2020] [Indexed: 12/25/2022] Open
Abstract
Despite attempts to halt it, the prevalence of food allergy is increasing, and there is an unmet need for strategies to prevent morbidity and mortality from food-induced allergic reactions. There are no known medications that can prevent anaphylaxis, but several novel therapies show promise for the prevention of food-induced anaphylaxis through targeting of the high-affinity IgE receptor (FcϵRI) pathway. This pathway includes multiple candidate targets, including tyrosine kinases and the receptor itself. Small molecule inhibitors of essential kinases have rapid onset of action and transient efficacy, which may be beneficial for short-term use for immunotherapy buildup or desensitizations. Short courses of FDA-approved inhibitors of Bruton’s tyrosine kinase can eliminate IgE-mediated basophil activation and reduce food skin test size in allergic adults, and prevent IgE-mediated anaphylaxis in humanized mice. In contrast, biologics may provide longer-lasting protection, albeit with slower onset. Omalizumab is an anti-IgE antibody that sequesters IgE, thereby reducing FcϵRI expression on mast cells and basophils. As a monotherapy, it can increase the clinical threshold dose of food allergen, and when used as an adjunct for food immunotherapy, it decreases severe reactions during buildup phase. Finally, lirentelimab, an anti-Siglec-8 antibody currently in clinical trials, can prevent IgE-mediated anaphylaxis in mice through mast cell inhibition. This review discusses these and other emerging therapies as potential strategies for preventing food-induced anaphylaxis. In contrast to other food allergy treatments which largely focus on individual allergens, blockade of the FcϵRI pathway has the advantage of preventing clinical reactivity from any food.
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Affiliation(s)
- Melanie C Dispenza
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Bruce S Bochner
- Department of Medicine, Division of Allergy and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Donald W MacGlashan
- Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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38
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Functions and therapeutic targets of Siglec-mediated infections, inflammations and cancers. J Formos Med Assoc 2021; 120:5-24. [DOI: 10.1016/j.jfma.2019.10.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/11/2019] [Accepted: 10/28/2019] [Indexed: 12/20/2022] Open
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39
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A monoclonal antibody to Siglec-8 suppresses non-allergic airway inflammation and inhibits IgE-independent mast cell activation. Mucosal Immunol 2021; 14:366-376. [PMID: 32814824 PMCID: PMC7946634 DOI: 10.1038/s41385-020-00336-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/30/2020] [Accepted: 07/27/2020] [Indexed: 02/04/2023]
Abstract
In addition to their well characterized role in mediating IgE-dependent allergic diseases, aberrant accumulation and activation of mast cells (MCs) is associated with many non-allergic inflammatory diseases, whereby their activation is likely triggered by non-IgE stimuli (e.g., IL-33). Siglec-8 is an inhibitory receptor expressed on MCs and eosinophils that has been shown to inhibit IgE-mediated MC responses and reduce allergic inflammation upon ligation with a monoclonal antibody (mAb). Herein, we evaluated the effects of an anti-Siglec-8 mAb (anti-S8) in non-allergic disease models of experimental cigarette-smoke-induced chronic obstructive pulmonary disease and bleomycin-induced lung injury in Siglec-8 transgenic mice. Therapeutic treatment with anti-S8 inhibited MC activation and reduced recruitment of immune cells, airway inflammation, and lung fibrosis. Similarly, using a model of MC-dependent, IL-33-induced inflammation, anti-S8 treatment suppressed neutrophil influx, and cytokine production through MC inhibition. Transcriptomic profiling of MCs further demonstrated anti-S8-mediated downregulation of MC signaling pathways induced by IL-33, including TNF signaling via NF-κB. Collectively, these findings demonstrate that ligating Siglec-8 with an antibody reduces non-allergic inflammation and inhibits IgE-independent MC activation, supporting the evaluation of an anti-Siglec-8 mAb as a therapeutic approach in both allergic and non-allergic inflammatory diseases in which MCs play a role.
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40
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Strategies for Mast Cell Inhibition in Food Allergy. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2020; 93:719-731. [PMID: 33380934 PMCID: PMC7757070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mast cells are tissue resident allergic effector cells that drive IgE-mediated food allergies. There are several steps leading to mast cell activation in the context of allergic disease that can be targeted to prevent mast cell activation and degranulation. These include blocking IgE-FcεRI crosslinking and type 2 cytokine receptor activation; modulating cell-surface neural chemical receptors; stabilizing mast cell membranes to prevent co-localization of activating receptors; impeding intracellular signaling; and engaging cell surface inhibitory receptors. This review highlights several ITIM-containing inhibitory mast cell surface receptors that could serve as pharmaceutical targets to prevent mast cell activation and degranulation in the context of food allergy. When activated, these ITIM-containing inhibitory receptors recruit the phosphatases SHP-1, SHP-2, and/or SHIP to dephosphorylate the tyrosine kinases responsible for activation signals downstream of the IgE-FcεRI complex. We describe several members of the Ig and Ig-like inhibitory receptor and C-type lectin inhibitory receptor superfamilies. Fundamental studies exploring the behavior of these receptors within the context of experimental food allergy models are needed. A deeper understanding of how these receptors modulate mast cell-driven food allergic responses will shape future strategies to harness these inhibitory receptors to treat food allergy.
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41
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Discovery, Function, and Therapeutic Targeting of Siglec-8. Cells 2020; 10:cells10010019. [PMID: 33374255 PMCID: PMC7823959 DOI: 10.3390/cells10010019] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/18/2020] [Accepted: 12/20/2020] [Indexed: 12/11/2022] Open
Abstract
Siglecs (sialic acid-binding immunoglobulin-like lectins) are single-pass cell surface receptors that have inhibitory activities on immune cells. Among these, Siglec-8 is a CD33-related family member selectively expressed on human mast cells and eosinophils, and at low levels on basophils. These cells can participate in inflammatory responses by releasing mediators that attract or activate other cells, contributing to the pathogenesis of allergic and non-allergic diseases. Since its discovery in 2000, initial in vitro studies have found that the engagement of Siglec-8 with a monoclonal antibody or with selective polyvalent sialoglycan ligands induced the cell death of eosinophils and inhibited mast cell degranulation. Anti-Siglec-8 antibody administration in vivo to humanized and transgenic mice selectively expressing Siglec-8 on mouse eosinophils and mast cells confirmed the in vitro findings, and identified additional anti-inflammatory effects. AK002 (lirentelimab) is a humanized non-fucosylated IgG1 antibody against Siglec-8 in clinical development for mast cell- and eosinophil-mediated diseases. AK002 administration has safely demonstrated the inhibition of mast cell activity and the depletion of eosinophils in several phase 1 and phase 2 trials. This article reviews the discovery and functions of Siglec-8, and strategies for its therapeutic targeting for the treatment of eosinophil- and mast cell-associated diseases.
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42
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Current Status on Therapeutic Molecules Targeting Siglec Receptors. Cells 2020; 9:cells9122691. [PMID: 33333862 PMCID: PMC7765293 DOI: 10.3390/cells9122691] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/09/2020] [Accepted: 12/12/2020] [Indexed: 12/15/2022] Open
Abstract
The sialic acid-binding immunoglobulin-type of lectins (Siglecs) are receptors that recognize sialic acid-containing glycans. In the majority of the cases, Siglecs are expressed on immune cells and play a critical role in regulating immune cell signaling. Over the years, it has been shown that the sialic acid-Siglec axis participates in immunological homeostasis, and that any imbalance can trigger different pathologies, such as autoimmune diseases or cancer. For all this, different therapeutics have been developed that bind to Siglecs, either based on antibodies or being smaller molecules. In this review, we briefly introduce the Siglec family and we compile a description of glycan-based molecules and antibody-based therapies (including CAR-T and bispecific antibodies) that have been designed to therapeutically targeting Siglecs.
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43
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44
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Kroezen BS, Conti G, Girardi B, Cramer J, Jiang X, Rabbani S, Müller J, Kokot M, Luisoni E, Ricklin D, Schwardt O, Ernst B. A Potent Mimetic of the Siglec-8 Ligand 6'-Sulfo-Sialyl Lewis x. ChemMedChem 2020; 15:1706-1719. [PMID: 32744401 DOI: 10.1002/cmdc.202000417] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Indexed: 12/15/2022]
Abstract
Siglecs are members of the immunoglobulin gene family containing sialic acid binding N-terminal domains. Among them, Siglec-8 is expressed on various cell types of the immune system such as eosinophils, mast cells and weakly on basophils. Cross-linking of Siglec-8 with monoclonal antibodies triggers apoptosis in eosinophils and inhibits degranulation of mast cells, making Siglec-8 a promising target for the treatment of eosinophil- and mast cell-associated diseases such as asthma. The tetrasaccharide 6'-sulfo-sialyl Lewisx has been identified as a specific Siglec-8 ligand in glycan array screening. Here, we describe an extended study enlightening the pharmacophores of 6'-sulfo-sialyl Lewisx and the successful development of a high-affinity mimetic. Retaining the neuraminic acid core, the introduction of a carbocyclic mimetic of the Gal moiety and a sulfonamide substituent in the 9-position gave a 20-fold improved binding affinity. Finally, the residence time, which usually is the Achilles tendon of carbohydrate/lectin interactions, could be improved.
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Affiliation(s)
- Blijke S Kroezen
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Gabriele Conti
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Benedetta Girardi
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Jonathan Cramer
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Xiaohua Jiang
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Said Rabbani
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Jennifer Müller
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Maja Kokot
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Enrico Luisoni
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Daniel Ricklin
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Oliver Schwardt
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Beat Ernst
- Molecular Pharmacy Group Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
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45
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Kerr SC, Gonzalez JR, Schanin J, Peters MC, Lambrecht BN, Brock EC, Charbit A, Ansel KM, Youngblood BA, Fahy JV. An anti-siglec-8 antibody depletes sputum eosinophils from asthmatic subjects and inhibits lung mast cells. Clin Exp Allergy 2020; 50:904-914. [PMID: 32542913 DOI: 10.1111/cea.13681] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 04/24/2020] [Accepted: 05/29/2020] [Indexed: 01/09/2023]
Abstract
BACKGROUND Sialic acid-binding immunoglobulin-like lectin (Siglec)-8 is expressed on mast cells and eosinophils, but information about Siglec-8 expression and function in the lung is limited. A humanized antibody, AK002, targeting Siglec-8 is undergoing development for treatment of diseases associated with mast cell and eosinophil-driven inflammation. OBJECTIVE To characterize Siglec-8 expression in the airway in asthma and determine whether antibodies that target Siglec-8 (S8mAbs) can decrease airway eosinophils in asthma or inhibit lung mast cell activation. METHODS Gene expression profiling and flow cytometry were used to characterize Siglec-8 expression in sputum cells from stable asthma. An antibody-dependent cellular cytotoxicity (ADCC) assay was used to determine whether an S8mAb can decrease eosinophils in sputum from asthma patients ex vivo. A mast cell activation assay was used to determine whether an S8mAb can inhibit mast cell activation in human lung tissue ex vivo. RESULTS Gene expression for Siglec-8 is increased in sputum cells in asthma and correlates with gene expression for eosinophils and mast cells. Gene expression for Siglec-8 is inversely and significantly correlated with measures of airflow obstruction in asthma patients. Siglec-8 is prominently expressed on the surface of eosinophils and mast cells in sputum. S8mAbs decrease eosinophils in sputum from patients with asthma and inhibit FcεR1-activated mast cells in lung tissues. CONCLUSIONS AND CLINICAL RELEVANCE Siglec-8 is highly expressed on eosinophils and mast cells in asthmatic sputum and targeting Siglec-8 with an antibody is a plausible strategy to decrease sputum eosinophils and inhibit lung mast cells in asthma.
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Affiliation(s)
- Sheena C Kerr
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, CA, USA
| | - Jeanmarie R Gonzalez
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA.,Sandler Asthma Basic Research Center, University of California, San Francisco, CA, USA
| | | | - Michael C Peters
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, CA, USA
| | - Bart N Lambrecht
- VIB Center for Inflammation Research, Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | | | - Annabelle Charbit
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, CA, USA
| | - K M Ansel
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA.,Sandler Asthma Basic Research Center, University of California, San Francisco, CA, USA
| | | | - John V Fahy
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, CA, USA.,Sandler Asthma Basic Research Center, University of California, San Francisco, CA, USA
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O'Sullivan JA, Chang AT, Youngblood BA, Bochner BS. Eosinophil and mast cell Siglecs: From biology to drug target. J Leukoc Biol 2020; 108:73-81. [PMID: 31965606 PMCID: PMC7531194 DOI: 10.1002/jlb.2mr0120-352rr] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 12/26/2022] Open
Abstract
Mast cells and eosinophils are innate immune cells involved in both acute and chronic inflammatory responses. Siglecs are a family of cell surface receptors that share sialic acid binding activity. Over the past 20 years, our knowledge of the expression and function of Siglecs on cells of the immune system and others has greatly expanded, as has our understanding of their signaling, ligands, and possible roles in disease pathophysiology. Because of this, Siglecs have garnered interest as potential drug targets using strategies ranging from biologics to ligand-directed nanoparticles. This mini-review will highlight the state of our knowledge regarding human eosinophil and mast cell Siglecs, their biology, what they recognize, tools developed for in vitro and preclinical experimentation, and the status of ongoing efforts to develop drugs that engage eosinophil and mast cell Siglecs for potential therapeutic benefit.
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Affiliation(s)
- Jeremy A O'Sullivan
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | | | | | - Bruce S Bochner
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Graeter S, Simon HU, von Gunten S. Granulocyte death mediated by specific antibodies in intravenous immunoglobulin (IVIG). Pharmacol Res 2020; 154:104168. [DOI: 10.1016/j.phrs.2019.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/04/2019] [Accepted: 02/04/2019] [Indexed: 12/23/2022]
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Mukherjee K, Khatua B, Mandal C. Sialic Acid-Siglec-E Interactions During Pseudomonas aeruginosa Infection of Macrophages Interferes With Phagosome Maturation by Altering Intracellular Calcium Concentrations. Front Immunol 2020; 11:332. [PMID: 32184783 PMCID: PMC7059019 DOI: 10.3389/fimmu.2020.00332] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 02/10/2020] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa (PA) is commonly associated with nosocomial and chronic infections of lungs. We have earlier demonstrated that an acidic sugar, sialic acid, is present in PA which is recognized and bound by sialic acid binding immunoglobulin type lectins (siglecs) expressed on neutrophils. Here, we have tried to gain a detailed insight into the immunosuppressive role of sialic acid-siglec interactions in macrophage-mediated clearance of sialylated PA (PA+Sia). We have demonstrated that PA+Sia shows enhanced binding (~1.5-fold) to macrophages due to additional interactions between sialic acids and siglec-E and exhibited more phagocytosis. However, internalization of PA+Sia is associated with a reduction in respiratory burst and increase in anti-inflammatory cytokines secretion which is reversed upon desialylation of the bacteria. Phagocytosis of PA+Sia is also associated with reduced intracellular calcium ion concentrations and altered calcium-dependent signaling which negatively affects phagosome maturation. Consequently, although more PA+Sia was localized in early phagosomes (Rab5 compartment), only fewer bacteria reach into the late phagosomal compartment (Rab7). Possibly, this leads to reduced phagosome lysosome fusion where reduced numbers of PA+Sia are trafficked into lysosomes, compared to PA−Sia. Thus, internalized PA+Sia remain viable and replicates intracellularly in macrophages. We have also demonstrated that such siglec-E-sialic acid interaction recruited SHP-1/SHP-2 phosphatases which modulate MAPK and NF-κB signaling pathways. Disrupting sialic acid-siglec-E interaction by silencing siglec-E in macrophages results in improved bactericidal response against PA+Sia characterized by robust respiratory burst, enhanced intracellular calcium levels and nuclear translocation of p65 component of NF-κB complex leading to increased pro-inflammatory cytokine secretion. Taken together, we have identified that sialic acid-siglec-E interactions is another pathway utilized by PA in order to suppress macrophage antimicrobial responses and inhibit phagosome maturation, thereby persisting as an intracellular pathogen in macrophages.
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Affiliation(s)
- Kaustuv Mukherjee
- Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Biswajit Khatua
- Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Chitra Mandal
- Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
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Abstract
Sialic acid-binding immunoglobulin-type lectins (Siglecs) are expressed on the majority of white blood cells of the immune system and play critical roles in immune cell signaling. Through recognition of sialic acid-containing glycans as ligands, they help the immune system distinguish between self and nonself. Because of their restricted cell type expression and roles as checkpoints in immune cell responses in human diseases such as cancer, asthma, allergy, neurodegeneration, and autoimmune diseases they have gained attention as targets for therapeutic interventions. In this review we describe the Siglec family, its roles in regulation of immune cell signaling, current efforts to define its roles in disease processes, and approaches to target Siglecs for treatment of human disease.
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Affiliation(s)
- Shiteng Duan
- Departments of Molecular Medicine, and Immunology and Microbiology, Scripps Research, La Jolla, California 92037, USA;
| | - James C Paulson
- Departments of Molecular Medicine, and Immunology and Microbiology, Scripps Research, La Jolla, California 92037, USA;
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Vychytilova-Faltejskova P, Slaby O. MicroRNA-215: From biology to theranostic applications. Mol Aspects Med 2019; 70:72-89. [DOI: 10.1016/j.mam.2019.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 03/10/2019] [Accepted: 03/17/2019] [Indexed: 02/07/2023]
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