1
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Mariuzza RA, Shahid S, Karade SS. The immune checkpoint receptor LAG3: Structure, function, and target for cancer immunotherapy. J Biol Chem 2024; 300:107241. [PMID: 38556085 PMCID: PMC11061240 DOI: 10.1016/j.jbc.2024.107241] [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: 01/29/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024] Open
Abstract
Lymphocyte activation gene 3 protein (LAG3) is an immune checkpoint receptor that is highly upregulated on exhausted T cells in the tumor microenvironment. LAG3 transmits inhibitory signals to T cells upon binding to MHC class II and other ligands, rendering T cells dysfunctional. Consequently, LAG3 is a major target for cancer immunotherapy with many anti-LAG3 monoclonal antibodies (mAbs) that block LAG3 inhibitory activity in clinical trials. In this review, we examine the molecular basis for LAG3 function in light of recently determined crystal and cryoEM structures of this inhibitory receptor. We review what is known about LAG3 interactions with MHC class II, its canonical ligand, and the newly discovered ligands FGL1 and the T cell receptor (TCR)-CD3 complex, including current controversies over the relative importance of these ligands. We then address the development and mechanisms of action of anti-LAG3 mAbs in clinical trials for cancer immunotherapy. We discuss new strategies to therapeutically target LAG3 using mAbs that not only block the LAG3-MHC class II interaction, but also LAG3 interactions with FGL1 or TCR-CD3, or that disrupt LAG3 dimerization. Finally, we assess the possibility of developing mAbs that enhance, rather than block, LAG3 inhibitory activity as treatments for autoimmune diseases.
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Affiliation(s)
- Roy A Mariuzza
- W.M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA.
| | - Salman Shahid
- W.M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Sharanbasappa S Karade
- W.M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
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2
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Chand Daskhan G, Ton Tran HT, Cairo CW. Convergent synthesis of a hexadecavalent heterobifunctional ABO blood group glycoconjugate. Carbohydr Res 2024; 535:108988. [PMID: 38048747 DOI: 10.1016/j.carres.2023.108988] [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: 10/03/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/06/2023]
Abstract
Naturally occurring glycans are often found in a multivalent presentation. Cell surface receptors that recognize these displays may form clusters, which can lead to signalling or endocytosis. One of the challenges in generating synthetic displays of multivalent carbohydrates is providing high valency as well as access to heterofunctional conjugates to allow attachment of multiple antigens or payloads. We designed a strategy based on a set of bifunctional linkers to generate a heterobifunctional multivalent display of two carbohydrate antigens to bind BCR and CD22 with four and twelve antigen copies, respectively. We confirmed that the conjugates were able to engage both CD22 and BCR on cells by observing receptor clustering. The strategy is modular and would allow for alternative carbohydrate antigens to be attached bearing amine and alkyne groups and should be of interest for the development of immunomodulators and vaccines.
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Affiliation(s)
- Gour Chand Daskhan
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Hanh-Thuc Ton Tran
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Christopher W Cairo
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
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3
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Conti G, Bärenwaldt A, Rabbani S, Mühlethaler T, Sarcevic M, Jiang X, Schwardt O, Ricklin D, Pieters RJ, Läubli H, Ernst B. Tetra- and Hexavalent Siglec-8 Ligands Modulate Immune Cell Activation. Angew Chem Int Ed Engl 2023; 62:e202314280. [PMID: 37947772 DOI: 10.1002/anie.202314280] [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: 09/26/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023]
Abstract
Carbohydrate-binding proteins are generally characterized by poor affinities for their natural glycan ligands, predominantly due to the shallow and solvent-exposed binding sites. To overcome this drawback, nature has exploited multivalency to strengthen the binding by establishing multiple interactions simultaneously. The development of oligovalent structures frequently proved to be successful, not only for proteins with multiple binding sites, but also for proteins that possess a single recognition domain. Herein we present the syntheses of a number of oligovalent ligands for Siglec-8, a monomeric I-type lectin found on eosinophils and mast cells, alongside the thermodynamic characterization of their binding. While the enthalpic contribution of each binding epitope was within a narrow range to that of the monomeric ligand, the entropy penalty increased steadily with growing valency. Additionally, we observed a successful agonistic binding of the tetra- and hexavalent and, to an even larger extent, multivalent ligands to Siglec-8 on immune cells and modulation of immune cell activation. Thus, triggering a biological effect is not restricted to multivalent ligands but could be induced by low oligovalent ligands as well, whereas a monovalent ligand, despite binding with similar affinity, showed an antagonistic effect.
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Affiliation(s)
- Gabriele Conti
- Molecular Pharmacy Group, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
- Chemical Biology and Drug Discovery Group, Department of Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Anne Bärenwaldt
- Laboratory for Cancer Immunotherapy, Department of Biomedicine, University of Basel, Hebelstrasse 20, 4051, Basel, Switzerland
- Division of Medical Oncology, University Hospital Basel, Petersgraben 4, 4051, Basel, Switzerland
| | - Said Rabbani
- Molecular Pharmacy Group, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Tobias Mühlethaler
- Biophysics Facility, Department Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Mirza Sarcevic
- Laboratory for Cancer Immunotherapy, Department of Biomedicine, University of Basel, Hebelstrasse 20, 4051, Basel, Switzerland
- Division of Medical Oncology, University Hospital Basel, Petersgraben 4, 4051, Basel, Switzerland
| | - Xiaohua Jiang
- 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
| | - Daniel Ricklin
- Molecular Pharmacy Group, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Roland J Pieters
- Chemical Biology and Drug Discovery Group, Department of Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Heinz Läubli
- Laboratory for Cancer Immunotherapy, Department of Biomedicine, University of Basel, Hebelstrasse 20, 4051, Basel, Switzerland
- Division of Medical Oncology, University Hospital Basel, Petersgraben 4, 4051, Basel, Switzerland
| | - Beat Ernst
- Molecular Pharmacy Group, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
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4
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Apley KD, Griffith AS, Downes GM, Ross P, Farrell MP, Kendall P, Berkland CJ. CD22L Conjugation to Insulin Attenuates Insulin-Specific B Cell Activation. Bioconjug Chem 2023; 34:2077-2088. [PMID: 37883211 PMCID: PMC11034786 DOI: 10.1021/acs.bioconjchem.3c00391] [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] [Indexed: 10/28/2023]
Abstract
Pancreatic islet-reactive B lymphocytes promote Type 1 diabetes (T1D) by presenting an antigen to islet-destructive T cells. Teplizumab, an anti-CD3 monoclonal, delays T1D onset in patients at risk, but additional therapies are needed to prevent the disease entirely. Therefore, bifunctional molecules were designed to selectively inhibit T1D-promoting anti-insulin B cells by conjugating a ligand for the B cell inhibitory receptor CD22 (i.e., CD22L) to insulin, which permit these molecules to concomitantly bind to anti-insulin B cell receptors (BCRs) and CD22. Two prototypes were synthesized: 2:2 insulin-CD22L conjugate on a 4-arm PEG backbone, and 1:1 insulin-CD22L direct conjugate. Transgenic mice (125TgSD) expressing anti-insulin BCRs provided cells for in vitro testing. Cells were cultured with constructs for 3 days, then assessed by flow cytometry. Duplicate wells with anti-CD40 simulated T cell help. A 2-insulin 4-arm PEG control caused robust proliferation and activation-induced CD86 upregulation. Anti-CD40 further boosted these effects. This may indicate that BCR-cross-linking occurs when antigens are tethered by the PEG backbone as soluble insulin alone has no effect. Addition of CD22L via the 2:2 insulin-CD22L conjugate restored B cell properties to that of controls without an additional beneficial effect. In contrast, the 1:1 insulin-CD22L direct conjugate significantly reduced anti-insulin B cell proliferation in the presence of anti-CD40. CD22L alone had no effect, and the constructs did not affect the WT B cells. Thus, multivalent antigen constructs tend to activate anti-insulin B cells, while monomeric antigen-CD22L conjugates reduce B cell activation in response to simulated T cell help and reduce pathogenic B cell numbers without harming normal cells. Therefore, monomeric antigen-CD22L conjugates warrant futher study and may be promising candidates for preclinical trials to prevent T1D without inducing immunodeficiency.
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Affiliation(s)
- Kyle D Apley
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Amber S Griffith
- Department of Medicine, Division of Allergy and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Grant M Downes
- Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas 66045, United States
| | - Patrick Ross
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Mark P Farrell
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Peggy Kendall
- Department of Medicine, Division of Allergy and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Cory J Berkland
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
- Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, Kansas 66045, United States
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130, United States
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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5
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Hui E. Cis Interactions of Membrane Receptors and Ligands. Annu Rev Cell Dev Biol 2023; 39:391-408. [PMID: 37339682 DOI: 10.1146/annurev-cellbio-120420-103941] [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: 06/22/2023]
Abstract
Cell-cell communication is critical for the development and function of multicellular organisms. A crucial means by which cells communicate with one another is physical interactions between receptors on one cell and their ligands on a neighboring cell. Trans ligand:receptor interactions activate the receptor, ultimately leading to changes in the fate of the receptor-expressing cells. Such trans signaling is known to be critical for the functions of cells in the nervous and immune systems, among others. Historically, trans interactions are the primary conceptual framework for understanding cell-cell communication. However, cells often coexpress many receptors and ligands, and a subset of these has been reported to interact in cis and profoundly impact cell functions. Cis interactions likely constitute a fundamental, understudied regulatory mechanism in cell biology. Here, I discuss how cis interactions between membrane receptors and ligands regulate immune cell functions, and I also highlight outstanding questions in the field.
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Affiliation(s)
- Enfu Hui
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, California, USA;
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6
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Ye Z, Wang Y, Xiang B, Wang H, Tao H, Zhang C, Zhang S, Sun D, Luo F, Song L. Roles of the Siglec family in bone and bone homeostasis. Biomed Pharmacother 2023; 165:115064. [PMID: 37413904 DOI: 10.1016/j.biopha.2023.115064] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/23/2023] [Accepted: 06/23/2023] [Indexed: 07/08/2023] Open
Abstract
Tremendous progress has been seen in the study of the role of sialic acid binding im-munoglobulin type lectins (Siglecs) in osteoimmunology in the past two decades. Interest in Siglecs as immune checkpoints has grown from the recognition that Siglecs have relevance to human disease. Siglecs play important roles in inflammation and cancer, and play key roles in immune cell signaling. By recognizing common sialic acid containing glycans on glycoproteins and glycolipids as regulatory receptors for immune cell signals, Siglecs are expressed on most immune cells and play important roles in normal homeostasis and self-tolerance. In this review, we describe the role that the siglec family plays in bone and bone homeostasis, including the regulation of osteoclast differentiation as well as recent advances in inflammation, cancer and osteoporosis. Particular emphasis is placed on the relevant functions of Siglecs in self-tolerance and as pattern recognition receptors in immune responses, thereby potentially providing emerging strategies for the treatment of bone related diseases.
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Affiliation(s)
- Zi Ye
- The Fourth Corps of Students of the Basic Medical College, Army Medical University, Chongqing 400037, China
| | - Yetong Wang
- The Fourth Corps of Students of the Basic Medical College, Army Medical University, Chongqing 400037, China
| | - Binqing Xiang
- Department of Surgical Anesthesia, First Affiliated Hospital, Army Medical University, Chongqing 400038, China
| | - Heng Wang
- Army Border Defense 331st Brigade, Dandong 118000, China
| | - Haiyan Tao
- Health Management Center, First Affiliated Hospital, Army Medical University, Chongqing 400038, China
| | - Chengmin Zhang
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, Chongqing 400038, China
| | - Shuai Zhang
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, Chongqing 400038, China
| | - Dong Sun
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, Chongqing 400038, China.
| | - Fei Luo
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, Chongqing 400038, China.
| | - Lei Song
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, Chongqing 400038, China.
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7
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Trzos S, Link-Lenczowski P, Pocheć E. The role of N-glycosylation in B-cell biology and IgG activity. The aspects of autoimmunity and anti-inflammatory therapy. Front Immunol 2023; 14:1188838. [PMID: 37575234 PMCID: PMC10415207 DOI: 10.3389/fimmu.2023.1188838] [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: 03/17/2023] [Accepted: 06/28/2023] [Indexed: 08/15/2023] Open
Abstract
The immune system is strictly regulated by glycosylation through the addition of highly diverse and dynamically changing sugar structures (glycans) to the majority of immune cell receptors. Although knowledge in the field of glycoimmunology is still limited, numerous studies point to the key role of glycosylation in maintaining homeostasis, but also in reflecting its disruption. Changes in oligosaccharide patterns can lead to impairment of both innate and acquired immune responses, with important implications in the pathogenesis of diseases, including autoimmunity. B cells appear to be unique within the immune system, since they exhibit both innate and adaptive immune activity. B cell surface is rich in glycosylated proteins and lectins which recognise glycosylated ligands on other cells. Glycans are important in the development, selection, and maturation of B cells. Changes in sialylation and fucosylation of cell surface proteins affect B cell signal transduction through BCRs, CD22 inhibitory coreceptor and Siglec-G. Plasmocytes, as the final stage of B cell differentiation, produce and secrete immunoglobulins (Igs), of which IgGs are the most abundant N-glycosylated proteins in human serum with the conserved N-glycosylation site at Asn297. N-oligosaccharide composition of the IgG Fc region affects its secretion, structure, half-life and effector functions (ADCC, CDC). IgG N-glycosylation undergoes little change during homeostasis, and may gradually be modified with age and during ongoing inflammatory processes. Hyperactivated B lymphocytes secrete autoreactive antibodies responsible for the development of autoimmunity. The altered profile of IgG N-glycans contributes to disease progression and remission and is sensitive to the application of therapeutic substances and immunosuppressive agents. In this review, we focus on the role of N-glycans in B-cell biology and IgG activity, the rearrangement of IgG oligosaccharides in aging, autoimmunity and immunosuppressive therapy.
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Affiliation(s)
- Sara Trzos
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, Poland
- Doctoral School of Exact and Natural Sciences, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Paweł Link-Lenczowski
- Department of Medical Physiology, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Ewa Pocheć
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, Poland
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8
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Leusmann S, Ménová P, Shanin E, Titz A, Rademacher C. Glycomimetics for the inhibition and modulation of lectins. Chem Soc Rev 2023; 52:3663-3740. [PMID: 37232696 PMCID: PMC10243309 DOI: 10.1039/d2cs00954d] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Indexed: 05/27/2023]
Abstract
Carbohydrates are essential mediators of many processes in health and disease. They regulate self-/non-self- discrimination, are key elements of cellular communication, cancer, infection and inflammation, and determine protein folding, function and life-times. Moreover, they are integral to the cellular envelope for microorganisms and participate in biofilm formation. These diverse functions of carbohydrates are mediated by carbohydrate-binding proteins, lectins, and the more the knowledge about the biology of these proteins is advancing, the more interfering with carbohydrate recognition becomes a viable option for the development of novel therapeutics. In this respect, small molecules mimicking this recognition process become more and more available either as tools for fostering our basic understanding of glycobiology or as therapeutics. In this review, we outline the general design principles of glycomimetic inhibitors (Section 2). This section is then followed by highlighting three approaches to interfere with lectin function, i.e. with carbohydrate-derived glycomimetics (Section 3.1), novel glycomimetic scaffolds (Section 3.2) and allosteric modulators (Section 3.3). We summarize recent advances in design and application of glycomimetics for various classes of lectins of mammalian, viral and bacterial origin. Besides highlighting design principles in general, we showcase defined cases in which glycomimetics have been advanced to clinical trials or marketed. Additionally, emerging applications of glycomimetics for targeted protein degradation and targeted delivery purposes are reviewed in Section 4.
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Affiliation(s)
- Steffen Leusmann
- Chemical Biology of Carbohydrates (CBCH), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, 66123 Saarbrücken, Germany.
- Department of Chemistry, Saarland University, 66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), Standort Hannover-Braunschweig, Germany
| | - Petra Ménová
- University of Chemistry and Technology, Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Elena Shanin
- Department of Pharmaceutical Sciences, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria.
- Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Biocenter 5, 1030 Vienna, Austria
| | - Alexander Titz
- Chemical Biology of Carbohydrates (CBCH), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, 66123 Saarbrücken, Germany.
- Department of Chemistry, Saarland University, 66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), Standort Hannover-Braunschweig, Germany
| | - Christoph Rademacher
- Department of Pharmaceutical Sciences, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria.
- Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Biocenter 5, 1030 Vienna, Austria
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9
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Siddiqui SS. Non-canonical roles of Siglecs: Beyond sialic acid-binding and immune cell modulation. Mol Aspects Med 2023; 90:101145. [PMID: 36153172 DOI: 10.1016/j.mam.2022.101145] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/11/2022] [Accepted: 09/13/2022] [Indexed: 02/08/2023]
Abstract
Siglecs (Sialic acid-binding immunoglobulin-type lectins) are I-type lectins that bind with sialic acid ligands (Sia). Most are expressed on the surface of leukocytes and are involved in immune regulation and possess immune tyrosine-based inhibitory motif (ITIM) in the intracellular domain, thus leading to inhibition of the immune response. This signaling is instrumental in maintaining quiescence under physiological conditions and acts as a brake for inflammatory cascades. By contrast, activating Siglecs carry positively charged residues in the transmembrane domain and interact with immune tyrosine-based activating motif (ITAM)-containing proteins, a DNAX-activating protein of 10-12 kDa (DAP10/12), to activate immune cells. There are various characteristics of Siglecs that do not fit within the classification of Siglec receptors as being either inhibitory or activating in nature. This review focuses on elucidating the non-canonical functions and interactions of Siglec receptors, which include Sia-independent interactions such as protein-protein interactions and interactions with lipids or other sugars. This review also summarizes Siglec expression and function on non-immune cells, and non-classical signaling of the receptor. Thus, this review will be beneficial to researchers interested in the field of Siglecs and sialic acid biology.
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Affiliation(s)
- Shoib Sarwar Siddiqui
- School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, AL10 9AB, United Kingdom.
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10
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Abstract
Siglecs are a family of immunomodulatory cell surface receptors present on white blood cells. Binding to cell surface sialic acid-containing glycans modulates the proximity of Siglecs to other receptors that they regulate. This proximity is key to enabling signaling motifs on the cytosolic domain of Siglecs to modulate immune responses. Given the important roles that Siglecs play in helping to maintain immune homeostasis, a better understanding of their glycan ligands is needed to elucidate their roles in health and disease. A common approach for probing Siglec ligands on cells is to use soluble versions of the recombinant Siglecs in conjunction with flow cytometry. Flow cytometry has many advantages in enabling the relative levels of Siglec ligands between cell types to be rapidly quantified. Here, a step-by-step protocol is described on how to detect Siglec ligands most sensitively and accurately on cells by flow cytometry.
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Affiliation(s)
- Edward N Schmidt
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Jaesoo Jung
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Matthew S Macauley
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada.
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada.
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11
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Cooper O, Waespy M, Chen D, Kelm S, Li Q, Haselhorst T, Tiralongo J. Sugar-decorated carbon dots: a novel tool for targeting immunomodulatory receptors. NANOSCALE ADVANCES 2022; 4:5355-5364. [PMID: 36540112 PMCID: PMC9729803 DOI: 10.1039/d2na00364c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
Interactions between sialic acid (Sia) and sialic acid-binding immunoglobulin-like lectins (siglecs) regulate the immune system, with aberrations contributing to pathologies such as autoimmunity, infectious disease and cancer. Over the last decade, several multivalent Sia ligands have been synthesized to modulate the Sia-binding affinity of proteins/lectins. Here, we report a novel class of multivalent siglec probes through the decoration of α(2,6)-sialyllactose ligands on inherently fluorescent carbon dots (CD). We show that the preference of α(2,3)-linked Sia for siglec-1 can be altered by increasing the multivalence of Sia ligands present on the CD, and that a locally high glycan concentration can have a direct effect on linkage specificity. Additionally, micromolar (IC50 ∼ 70 μM) interaction of α(2,6)-sialyllactose-CD (6-CD) with siglec-2 (CD22) revealed it was capable of generating a significant cytotoxic effect on Burkitt's Lymphoma (BL) Daudi B cells. This phenonomen was attributed to 6-CD's ability to form trans interactions with CD22 on masked BL Daudi cells as a direct result of clustering of the Sia moiety on the CD surface. Overall, our glycoengineered carbon dots represent a novel high affinity molecular probe with multiple applications in sialoglycoscience and medicine.
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Affiliation(s)
- Oren Cooper
- Institute for Glycomics, Gold Coast Campus, Griffith University Queensland 4222 Australia
| | - Mario Waespy
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen 28334 Bremen Germany
| | - Dechao Chen
- School of Engineering and Built Environment, Nathan Campus, Griffith University QLD 4111 Australia
| | - Sørge Kelm
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen 28334 Bremen Germany
| | - Qin Li
- School of Engineering and Built Environment, Nathan Campus, Griffith University QLD 4111 Australia
- Queensland Micro- and Nanotechnology Centre, Australia, Nathan Campus, Griffith University QLD 4111 Australia
| | - Thomas Haselhorst
- Institute for Glycomics, Gold Coast Campus, Griffith University Queensland 4222 Australia
| | - Joe Tiralongo
- Institute for Glycomics, Gold Coast Campus, Griffith University Queensland 4222 Australia
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12
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Prescher H, Schweizer A, Frank M, Kuhfeldt E, Ring J, Nitschke L. Targeting Human CD22/Siglec-2 with Dimeric Sialosides as Novel Oligosaccharide Mimetics. J Med Chem 2022; 65:10588-10610. [PMID: 35881556 DOI: 10.1021/acs.jmedchem.2c00765] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Significant interest in the development of high-affinity ligands for Siglecs exists due to the various therapeutically relevant functions of these proteins. Here, we report a new strategy to develop and design Siglec ligands as disialyl-oligosaccharide mimetics exemplified on Siglec-2 (CD22). We report insights into development of dimeric ligands with high affinity and avidity to cell surface-expressed CD22, assay development, tool compounds, structure activity relationships, and biological data on calcium flux regulation in B-cells. The binding modes of selected ligands have been modeled based on state-of-the-art molecular dynamics simulations on the microsecond timescale, providing detailed views on ligand binding and opening a new perspective on drug design efforts for Siglecs. High-avidity dimeric ligands containing a linker opening the way towards bispecifics are presented as well.
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Affiliation(s)
| | - Astrid Schweizer
- Chair of Genetics, Department of Biology, University of Erlangen, 91058 Erlangen, Germany
| | - Martin Frank
- Biognos AB, Generatorsgatan 1, 40274 Göteborg, Sweden
| | | | - Julia Ring
- Chair of Genetics, Department of Biology, University of Erlangen, 91058 Erlangen, Germany
| | - Lars Nitschke
- Chair of Genetics, Department of Biology, University of Erlangen, 91058 Erlangen, Germany
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13
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Radovani B, Gudelj I. N-Glycosylation and Inflammation; the Not-So-Sweet Relation. Front Immunol 2022; 13:893365. [PMID: 35833138 PMCID: PMC9272703 DOI: 10.3389/fimmu.2022.893365] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/30/2022] [Indexed: 12/28/2022] Open
Abstract
Chronic inflammation is the main feature of many long-term inflammatory diseases such as autoimmune diseases, metabolic disorders, and cancer. There is a growing number of studies in which alterations of N-glycosylation have been observed in many pathophysiological conditions, yet studies of the underlying mechanisms that precede N-glycome changes are still sparse. Proinflammatory cytokines have been shown to alter the substrate synthesis pathways as well as the expression of glycosyltransferases required for the biosynthesis of N-glycans. The resulting N-glycosylation changes can further contribute to disease pathogenesis through modulation of various aspects of immune cell processes, including those relevant to pathogen recognition and fine-tuning the inflammatory response. This review summarizes our current knowledge of inflammation-induced N-glycosylation changes, with a particular focus on specific subsets of immune cells of innate and adaptive immunity and how these changes affect their effector functions, cell interactions, and signal transduction.
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Affiliation(s)
- Barbara Radovani
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Ivan Gudelj
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
- Genos Glycoscience Research Laboratory, Zagreb, Croatia
- *Correspondence: Ivan Gudelj,
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14
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Enterina JR, Sarkar S, Streith L, Jung J, Arlian BM, Meyer SJ, Takematsu H, Xiao C, Baldwin TA, Nitschke L, Shlomchick MJ, Paulson JC, Macauley MS. Coordinated changes in glycosylation regulate the germinal center through CD22. Cell Rep 2022; 38:110512. [PMID: 35294874 PMCID: PMC9018098 DOI: 10.1016/j.celrep.2022.110512] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 01/19/2022] [Accepted: 02/16/2022] [Indexed: 12/18/2022] Open
Abstract
Germinal centers (GCs) are essential for antibody affinity maturation. GC B cells have a unique repertoire of cell surface glycans compared with naive B cells, yet functional roles for changes in glycosylation in the GC have yet to be ascribed. Detection of GCs by the antibody GL7 reflects a downregulation in ligands for CD22, an inhibitory co-receptor of the B cell receptor. To test a functional role for downregulation of CD22 ligands in the GC, we generate a mouse model that maintains CD22 ligands on GC B cells. With this model, we demonstrate that glycan remodeling plays a critical role in the maintenance of B cells in the GC. Sustained expression of CD22 ligands induces higher levels of apoptosis in GC B cells, reduces memory B cell and plasma cell output, and delays affinity maturation of antibodies. These defects are CD22 dependent, demonstrating that downregulation of CD22 ligands on B cells plays a critical function in the GC.
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Affiliation(s)
- Jhon R Enterina
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Susmita Sarkar
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Laura Streith
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Jaesoo Jung
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Britni M Arlian
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sarah J Meyer
- Division of Genetics, Department of Biology, University of Erlangen, 91058 Erlangen, Germany
| | - Hiromu Takematsu
- Faculty of Medical Technology, Fujita Health University, Aichi 470-1192, Japan
| | - Changchun Xiao
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Troy A Baldwin
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Lars Nitschke
- Division of Genetics, Department of Biology, University of Erlangen, 91058 Erlangen, Germany
| | - Mark J Shlomchick
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - James C Paulson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Matthew S Macauley
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada; Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada.
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15
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van Houtum EJH, Büll C, Cornelissen LAM, Adema GJ. Siglec Signaling in the Tumor Microenvironment. Front Immunol 2021; 12:790317. [PMID: 34966391 PMCID: PMC8710542 DOI: 10.3389/fimmu.2021.790317] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/23/2021] [Indexed: 12/16/2022] Open
Abstract
Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of receptors that recognize sialoglycans - sialic acid containing glycans that are abundantly present on cell membranes. Siglecs are expressed on most immune cells and can modulate their activity and function. The majority of Siglecs contains immune inhibitory motifs comparable to the immune checkpoint receptor PD-1. In the tumor microenvironment (TME), signaling through the Siglec-sialoglycan axis appears to be enhanced through multiple mechanisms favoring tumor immune evasion similar to the PD-1/PD-L1 signaling pathway. Siglec expression on tumor-infiltrating immune cells appears increased in the immune suppressive microenvironment. At the same time, enhanced Siglec ligand expression has been reported for several tumor types as a result of aberrant glycosylation, glycan modifications, and the increased expression of sialoglycans on proteins and lipids. Siglec signaling has been identified as important regulator of anti-tumor immunity in the TME, but the key factors contributing to Siglec activation by tumor-associated sialoglycans are diverse and poorly defined. Among others, Siglec activation and signaling are co-determined by their expression levels, cell surface distribution, and their binding preferences for cis- and trans-ligands in the TME. Siglec binding preference are co-determined by the nature of the proteins/lipids to which the sialoglycans are attached and the multivalency of the interaction. Here, we review the current understanding and emerging conditions and factors involved in Siglec signaling in the TME and identify current knowledge gaps that exist in the field.
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Affiliation(s)
- Eline J. H. van Houtum
- Radiotherapy & OncoImmunology Laboratory, Department of Radiation Oncology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Christian Büll
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), Utrecht, Netherlands
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lenneke A. M. Cornelissen
- Radiotherapy & OncoImmunology Laboratory, Department of Radiation Oncology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Gosse J. Adema
- Radiotherapy & OncoImmunology Laboratory, Department of Radiation Oncology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
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16
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Lim J, Sari-Ak D, Bagga T. Siglecs as Therapeutic Targets in Cancer. BIOLOGY 2021; 10:1178. [PMID: 34827170 PMCID: PMC8615218 DOI: 10.3390/biology10111178] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 02/06/2023]
Abstract
Hypersialylation is a common post-translational modification of protein and lipids found on cancer cell surfaces, which participate in cell-cell interactions and in the regulation of immune responses. Sialic acids are a family of nine-carbon α-keto acids found at the outermost ends of glycans attached to cell surfaces. Given their locations on cell surfaces, tumor cells aberrantly overexpress sialic acids, which are recognized by Siglec receptors found on immune cells to mediate broad immunomodulatory signaling. Enhanced sialylation exposed on cancer cell surfaces is exemplified as "self-associated molecular pattern" (SAMP), which tricks Siglec receptors found on leukocytes to greatly down-regulate immune responsiveness, leading to tumor growth. In this review, we focused on all 15 human Siglecs (including Siglec XII), many of which still remain understudied. We also highlighted strategies that disrupt the course of Siglec-sialic acid interactions, such as antibody-based therapies and sialic acid mimetics leading to tumor cell depletion. Herein, we introduced the central roles of Siglecs in mediating pro-tumor immunity and discussed strategies that target these receptors, which could benefit improved cancer immunotherapy.
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Affiliation(s)
- Jackwee Lim
- Singapore Immunology Network, A*STAR, 8a Biomedical Grove, Singapore 138648, Singapore;
| | - Duygu Sari-Ak
- Department of Medical Biology, School of Medicine, University of Health Sciences, Istanbul 34668, Turkey;
| | - Tanaya Bagga
- Singapore Immunology Network, A*STAR, 8a Biomedical Grove, Singapore 138648, Singapore;
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17
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Hyun JY, Kim S, Lee CH, Lee HS, Shin I. Efficient Preparation and Bioactivity Evaluation of Glycan-Defined Glycoproteins. ACS Chem Biol 2021; 16:1930-1940. [PMID: 33232137 DOI: 10.1021/acschembio.0c00629] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Owing to the generation of heterogeneous glycoproteins in cells, it is highly difficult to study glycoprotein-mediated biological events and to develop biomedical agents. Thus, general and efficient methods to prepare homogeneous glycoproteins are in high demand. Herein, we report a general method for the efficient preparation of homogeneous glycoproteins that utilizes a combination of genetic code expansion and chemoselective ligation techniques. In the protocol to produce glycan-defined glycoproteins, an alkyne tag-containing protein, generated by genetic encoding of an alkynylated unnatural amino acid, was quantitatively coupled via click chemistry to versatile azide-appended glycans. The glycoproteins produced by the present strategy were found to recognize mammalian cell-surface lectins and enter the cells through lectin-mediated internalization. Also, cell studies exhibited that the glycoprotein containing multiple mannose-6-phosphate residues enters diseased cells lacking specific lysosomal glycosidases by binding to the cell-surface M6P receptor, and subsequently migrates to lysosomes for efficient degradation of stored glycosphingolipids.
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Affiliation(s)
- Ji Young Hyun
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
- Data Convergence Drug Research Center, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Sanggil Kim
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Chang-Hee Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Hyun Soo Lee
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Injae Shin
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
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18
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Edgar L, Thompson AJ, Vartabedian VF, Kikuchi C, Woehl JL, Teijaro JR, Paulson JC. Sialic Acid Ligands of CD28 Suppress Costimulation of T Cells. ACS CENTRAL SCIENCE 2021; 7:1508-1515. [PMID: 34584952 PMCID: PMC8461770 DOI: 10.1021/acscentsci.1c00525] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Indexed: 05/07/2023]
Abstract
Effector T cells comprise the cellular arm of the adaptive immune system and are essential for mounting immune responses against pathogens and cancer. To reach effector status, costimulation through CD28 is required. Here, we report that sialic acid-containing glycans on the surface of both T cells and APCs are alternative ligands of CD28 that compete with binding to its well-documented activatory ligand CD80 on the APC, resulting in attenuated costimulation. Removal of sialic acids enhances antigen-mediated activation of naïve T cells and also increases the revival of effector T cells made hypofunctional or exhausted via chronic viral infection. This occurs through a mechanism that is synergistic with antibody blockade of the inhibitory PD-1 axis. These results reveal a previously unrecognized role of sialic acid ligands in attenuation of CD28-mediated costimulation of T cells.
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Affiliation(s)
- Landon
J. Edgar
- Department
of Molecular Medicine, The Scripps Research
Institute, La Jolla, California 92037, United States
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Andrew J. Thompson
- Department
of Molecular Medicine, The Scripps Research
Institute, La Jolla, California 92037, United States
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Vincent F. Vartabedian
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Chika Kikuchi
- Department
of Molecular Medicine, The Scripps Research
Institute, La Jolla, California 92037, United States
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Jordan L. Woehl
- Department
of Molecular Medicine, The Scripps Research
Institute, La Jolla, California 92037, United States
| | - John R. Teijaro
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - James C. Paulson
- Department
of Molecular Medicine, The Scripps Research
Institute, La Jolla, California 92037, United States
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
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19
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Hong S, Yu C, Rodrigues E, Shi Y, Chen H, Wang P, Chapla DG, Gao T, Zhuang R, Moremen KW, Paulson JC, Macauley MS, Wu P. Modulation of Siglec-7 Signaling Via In Situ-Created High-Affinity cis-Ligands. ACS CENTRAL SCIENCE 2021; 7:1338-1346. [PMID: 34471678 PMCID: PMC8393205 DOI: 10.1021/acscentsci.1c00064] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Indexed: 05/04/2023]
Abstract
Sialic acid-binding immunoglobulin-like lectins, also known as Siglecs, have recently been designated as glyco-immune checkpoints. Through their interactions with sialylated glycan ligands overexpressed on tumor cells, inhibitory Siglecs on innate and adaptive immune cells modulate signaling cascades to restrain anti-tumor immune responses. However, the elucidation of the mechanisms underlying these processes is just beginning. We find that when human natural killer (NK) cells attack tumor cells, glycan remodeling occurs on the target cells at the immunological synapse. This remodeling occurs through both the transfer of sialylated glycans from NK cells to target tumor cells and the accumulation of de novo synthesized sialosides on the tumor cells. The functionalization of NK cells with a high-affinity ligand of Siglec-7 leads to multifaceted consequences in modulating a Siglec-7-regulated NK-activation. At high levels of ligand, an enzymatically added Siglec-7 ligand suppresses NK cytotoxicity through the recruitment of Siglec-7 to an immune synapse, whereas at low levels of ligand an enzymatically added Siglec-7 ligand triggers the release of Siglec-7 from the cell surface into the culture medium, preventing a Siglec-7-mediated inhibition of NK cytotoxicity. These results suggest that a glycan engineering of NK cells may provide a means to boost NK effector functions for related applications.
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Affiliation(s)
- Senlian Hong
- State
Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology
Center, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Chenhua Yu
- Department of Molecular Medicine, Department of Immunology
and Microbiology, The Scripps Research Institute, La Jolla 92037, California, United States
- Tianjin
Medical University Cancer Institute and Hospital, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin 300060, China
| | - Emily Rodrigues
- Department of Chemistry, Department of Medical
Microbiology and Immunology, University
of Alberta, 11227 Saskatchewan Drive NW, Edmonton AB T6G 2G2, Alberta, Canada
| | - Yujie Shi
- Department of Molecular Medicine, Department of Immunology
and Microbiology, The Scripps Research Institute, La Jolla 92037, California, United States
| | - Hongmin Chen
- State
Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology
Center, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Peng Wang
- Department of Molecular Medicine, Department of Immunology
and Microbiology, The Scripps Research Institute, La Jolla 92037, California, United States
| | - Digantkumar G. Chapla
- Complex
Carbohydrate Research Center, University
of Georgia, Athens, Georgia 30602, United States
| | - Tao Gao
- State
Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology
Center, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Ruoxuan Zhuang
- State
Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology
Center, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Kelley W. Moremen
- Complex
Carbohydrate Research Center, University
of Georgia, Athens, Georgia 30602, United States
| | - James C. Paulson
- Department of Molecular Medicine, Department of Immunology
and Microbiology, The Scripps Research Institute, La Jolla 92037, California, United States
| | - Matthew S. Macauley
- Department of Chemistry, Department of Medical
Microbiology and Immunology, University
of Alberta, 11227 Saskatchewan Drive NW, Edmonton AB T6G 2G2, Alberta, Canada
| | - Peng Wu
- Department of Molecular Medicine, Department of Immunology
and Microbiology, The Scripps Research Institute, La Jolla 92037, California, United States
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20
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Meyer SJ, Steffensen M, Acs A, Weisenburger T, Wadewitz C, Winkler TH, Nitschke L. CD22 Controls Germinal Center B Cell Receptor Signaling, Which Influences Plasma Cell and Memory B Cell Output. THE JOURNAL OF IMMUNOLOGY 2021; 207:1018-1032. [PMID: 34330755 DOI: 10.4049/jimmunol.2100132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/05/2021] [Indexed: 12/23/2022]
Abstract
Germinal center reactions are established during a thymus-dependent immune response. Germinal center (GC) B cells are rapidly proliferating and undergo somatic hypermutation in Ab genes. This results in the production of high-affinity Abs and establishment of long-lived memory cells. GC B cells show lower BCR-induced signaling when compared with naive B cells, but the functional relevance is not clear. CD22 is a member of the Siglec family and functions as an inhibitory coreceptor on B cells. Interestingly, GC B cells downregulate sialic acid forms that serve as high-affinity ligands for CD22, indicating a role for CD22 ligand binding during GC responses. We studied the role of CD22 in the GC with mixed bone marrow chimeric mice and found a disadvantage of CD22-/- GC B cells during the GC reaction. Mechanistic investigations ruled out defects in dark zone/light zone distribution and affinity maturation. Rather, an increased rate of apoptosis in CD22-/- GC B cells was responsible for the disadvantage, also leading to a lower GC output in plasma cells and memory B cells. CD22-/- GC B cells showed a clearly increased calcium response upon BCR stimulation, which was almost absent in wild-type GC B cells. We conclude that the differential expression of the low-affinity cis CD22 ligands in the GC normally results in a strong attenuation of BCR signaling in GC B cells, probably due to higher CD22-BCR interactions. Therefore, attenuation of BCR signaling by CD22 is involved in GC output and B cell fate.
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Affiliation(s)
- Sarah J Meyer
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Marie Steffensen
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Andreas Acs
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Thomas Weisenburger
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Charlotte Wadewitz
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Thomas H Winkler
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Lars Nitschke
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
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21
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Matsuda Y, Watanabe T, Li XK. Approaches for Controlling Antibody-Mediated Allograft Rejection Through Targeting B Cells. Front Immunol 2021; 12:682334. [PMID: 34276669 PMCID: PMC8282180 DOI: 10.3389/fimmu.2021.682334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/17/2021] [Indexed: 01/14/2023] Open
Abstract
Both acute and chronic antibody-mediated allograft rejection (AMR), which are directly mediated by B cells, remain difficult to treat. Long-lived plasma cells (LLPCs) in bone marrow (BM) play a crucial role in the production of the antibodies that induce AMR. However, LLPCs survive through a T cell-independent mechanism and resist conventional immunosuppressive therapy. Desensitization therapy is therefore performed, although it is accompanied by severe side effects and the pathological condition may be at an irreversible stage when these antibodies, which induce AMR development, are detected in the serum. In other words, AMR control requires the development of a diagnostic method that predicts its onset before LLPC differentiation and enables therapeutic intervention and the establishment of humoral immune monitoring methods providing more detailed information, including individual differences in the susceptibility to immunosuppressive agents and the pathological conditions. In this study, we reviewed recent studies related to the direct or indirect involvement of immunocompetent cells in the differentiation of naïve-B cells into LLPCs, the limitations of conventional methods, and the possible development of novel control methods in the context of AMR. This information will significantly contribute to the development of clinical applications for AMR and improve the prognosis of patients who undergo organ transplantation.
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Affiliation(s)
- Yoshiko Matsuda
- Division of Transplantation Immunology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Takeshi Watanabe
- Laboratory of Immunology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Xiao-Kang Li
- Division of Transplantation Immunology, National Research Institute for Child Health and Development, Tokyo, Japan
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22
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Alborzian Deh Sheikh A, Akatsu C, Abdu-Allah HHM, Suganuma Y, Imamura A, Ando H, Takematsu H, Ishida H, Tsubata T. The Protein Tyrosine Phosphatase SHP-1 (PTPN6) but Not CD45 (PTPRC) Is Essential for the Ligand-Mediated Regulation of CD22 in BCR-Ligated B Cells. THE JOURNAL OF IMMUNOLOGY 2021; 206:2544-2551. [PMID: 33990399 DOI: 10.4049/jimmunol.2100109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/01/2021] [Indexed: 11/19/2022]
Abstract
CD22 is an inhibitory B cell coreceptor that regulates B cell development and activation by downregulating BCR signaling through activation of SH2-containing protein tyrosine phosphatase-1 (SHP-1). CD22 recognizes α2,6 sialic acid as a specific ligand and interacts with α2,6 sialic acid-containing membrane molecules, such as CD45, IgM, and CD22, expressed on the same cell. Functional regulation of CD22 by these endogenous ligands enhances BCR ligation-induced signaling and is essential for normal B cell responses to Ags. In this study, we demonstrate that CD45 plays a crucial role in CD22-mediated inhibition of BCR ligation-induced signaling. However, disruption of ligand binding of CD22 enhances CD22 phosphorylation, a process required for CD22-mediated signal inhibition, upon BCR ligation in CD45-/- as well as wild-type mouse B cells but not in mouse B cells expressing a loss-of-function mutant of SHP-1. This result indicates that SHP-1 but not CD45 is required for ligand-mediated regulation of CD22. We further demonstrate that CD22 is a substrate of SHP-1, suggesting that SHP-1 recruited to CD22 dephosphorylates nearby CD22 as well as other substrates. CD22 dephosphorylation by SHP-1 appears to be augmented by homotypic CD22 clustering mediated by recognition of CD22 as a ligand of CD22 because CD22 clustering increases the number of nearby CD22. Our results suggest that CD22 but not CD45 is an endogenous ligand of CD22 that enhances BCR ligation-induced signaling through SHP-1-mediated dephosphorylation of CD22 in CD22 clusters.
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Affiliation(s)
- Amin Alborzian Deh Sheikh
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Chizuru Akatsu
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | | | - Yuki Suganuma
- Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Akihiro Imamura
- Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Hiromune Ando
- Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University, Gifu, Japan.,Institute for Glyco-core Research, Gifu University, Gifu, Japan; and
| | - Hiromu Takematsu
- Faculty of Medical Technology, Fujita Health University, Toyoake, Aichi, Japan
| | - Hideharu Ishida
- Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.,Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University, Gifu, Japan
| | - Takeshi Tsubata
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan;
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23
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Klaus C, Liao H, Allendorf DH, Brown GC, Neumann H. Sialylation acts as a checkpoint for innate immune responses in the central nervous system. Glia 2020; 69:1619-1636. [PMID: 33340149 DOI: 10.1002/glia.23945] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 12/28/2022]
Abstract
Sialic acids are monosaccharides that normally terminate the glycan chains of cell surface glyco-proteins and -lipids in mammals, and are highly enriched in the central nervous tissue. Sialic acids are conjugated to proteins and lipids (termed "sialylation") by specific sialyltransferases, and are removed ("desialylation") by neuraminidases. Cell surface sialic acids are sensed by complement factor H (FH) to inhibit complement activation or by sialic acid-binding immunoglobulin-like lectin (SIGLEC) receptors to inhibit microglial activation, phagocytosis, and oxidative burst. In contrast, desialylation of cells enables binding of the opsonins C1, calreticulin, galectin-3, and collectins, stimulating phagocytosis of such cells. Hypersialylation is used by bacteria and cancers as camouflage to escape immune recognition, while polysialylation of neurons protects synapses and neurogenesis. Insufficient lysosomal cleavage of sialylated molecules can lead to lysosomal accumulation of lipids and aggregated proteins, which if excessive may be expelled into the extracellular space. On the other hand, desialylation of immune receptors can activate them or trigger removal of proteins. Loss of inhibitory SIGLECs or FH triggers reduced clearance of aggregates, oxidative brain damage and complement-mediated retinal damage. Thus, cell surface sialylation recognized by FH, SIGLEC, and other immune-related receptors acts as a major checkpoint inhibitor of innate immune responses in the central nervous system, while excessive cleavage of sialic acid residues and consequently removing this checkpoint inhibitor may trigger lipid accumulation, protein aggregation, inflammation, and neurodegeneration.
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Affiliation(s)
- Christine Klaus
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany
| | - Huan Liao
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany
| | | | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Harald Neumann
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany
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24
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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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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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Bachsais M, Salti S, Zaoui K, Hassan GS, Aoudjit F, Mourad W. CD154 inhibits death of T cells via a Cis interaction with the α5β1 integrin. PLoS One 2020; 15:e0235753. [PMID: 32745080 PMCID: PMC7398495 DOI: 10.1371/journal.pone.0235753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 06/22/2020] [Indexed: 12/30/2022] Open
Abstract
CD154 plays a major role in the pathogenesis of several autoimmune and inflammatory diseases. In addition to CD40, soluble CD154 (sCD154) binds to other receptors namely αIIbβ3, αMβ2, α5β1 and αvβ3 integrins. We have previously reported that binding of sCD154 to α5β1 integrin expressed on several human T cell lines is capable of inhibiting Fas-induced cell death. In the current study, we show that such effect of the sCD154/α5β1 interaction is not restricted to the cell death response induced by Fas but could also be exhibited toward other death signals such as TRAIL and TNF- α. We also demonstrate that sCD154 is capable of inhibiting Fas-mediated death of human activated T cells, more importantly of CD4+ than CD8+ T ones. Our data also show that membrane-bound CD154 and α5β1 integrin expressed on the surface of distinct cells failed to influence cell death responses. However, when membrane-bound CD154 and α5β1 are expressed on the surface of same cell, their interaction was capable of down regulating cell death. CD154 was shown to co-localize with the α5β1 integrin on the surface of these cells. These data strongly suggest a cis-type of interaction between CD154 and α5β1 when both are expressed on the same cell surface, rather than a trans-interaction which usually implicates the ligand and its receptor each expressed on the surface of a distinct cell. Taken together, these findings add to the list of roles through which CD154 is contributing to the pathogenesis of autoimmune-inflammatory diseases, i.e. by protecting T cells from death and enhancing their survival.
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Affiliation(s)
- Meriem Bachsais
- Laboratoire d’Immunologie Cellulaire et Moléculaire, Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CR-CHUM), Montréal, Québec, Canada
| | - Suzanne Salti
- Laboratoire d’Immunologie Cellulaire et Moléculaire, Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CR-CHUM), Montréal, Québec, Canada
| | - Kossay Zaoui
- Laboratoire d’Immunologie Cellulaire et Moléculaire, Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CR-CHUM), Montréal, Québec, Canada
| | - Ghada S. Hassan
- Laboratoire d’Immunologie Cellulaire et Moléculaire, Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CR-CHUM), Montréal, Québec, Canada
| | - Fawzi Aoudjit
- Centre de recherche du CHU de Québec-Université Laval, Québec, Québec, Canada
| | - Walid Mourad
- Laboratoire d’Immunologie Cellulaire et Moléculaire, Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CR-CHUM), Montréal, Québec, Canada
- * E-mail:
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27
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Liao H, Klaus C, Neumann H. Control of Innate Immunity by Sialic Acids in the Nervous Tissue. Int J Mol Sci 2020; 21:ijms21155494. [PMID: 32752058 PMCID: PMC7432451 DOI: 10.3390/ijms21155494] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022] Open
Abstract
Sialic acids (Sias) are the most abundant terminal sugar residues of glycoproteins and glycolipids on the surface of mammalian cells. The nervous tissue is the organ with the highest expression level of Sias. The ‘sialylation’ of glycoconjugates is performed via sialyltransferases, whereas ‘desialylation’ is done by sialidases or is a possible consequence of oxidative damage. Sialic acid residues on the neural cell surfaces inhibit complement and microglial activation, as well as phagocytosis of the underlying structures, via binding to (i) complement factor H (CFH) or (ii) sialic acid-binding immunoglobulin-like lectin (SIGLEC) receptors. In contrast, activated microglial cells show sialidase activity that desialylates both microglia and neurons, and further stimulates innate immunity via microglia and complement activation. The desialylation conveys neurons to become susceptible to phagocytosis, as well as triggers a microglial phagocytosis-associated oxidative burst and inflammation. Dysfunctions of the ‘Sia–SIGLEC’ and/or ‘Sia–complement’ axes often lead to neurological diseases. Thus, Sias on glycoconjugates of the intact glycocalyx and its desialylation are major regulators of neuroinflammation.
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Affiliation(s)
| | | | - Harald Neumann
- Correspondence: ; Tel.: +49-228-6885-500; Fax: +49-228-6885-501
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28
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Espinosa DA, Beatty PR, Puerta-Guardo H, Islam MN, Belisle JT, Perera R, Harris E. Increased serum sialic acid is associated with morbidity and mortality in a murine model of dengue disease. J Gen Virol 2020; 100:1515-1522. [PMID: 31526452 DOI: 10.1099/jgv.0.001319] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Dengue virus (DENV) causes the most prevalent arboviral infection of humans, resulting in a spectrum of outcomes, ranging from asymptomatic infection to dengue fever to severe dengue characterized by vascular leakage and shock. Previously, we determined that DENV nonstructural protein 1 (NS1) induces endothelial hyperpermeability, disrupts the endothelial glycocalyx layer (EGL) in vitro and triggers shedding of structural components, including sialic acid (Sia) and heparan sulfate. Here, using a murine model of dengue disease disease, we found high levels of Sia and NS1 circulating in mice with DENV-induced morbidity and lethal DENV infection. Further, we developed a liquid chromatography/mass spectrometry-based method for quantifying free Sia in serum and determined that the levels of free N-glycolylneuraminic acid were significantly higher in DENV-infected mice than in uninfected controls. These data provide additional evidence that DENV infection disrupts EGL components in vivo and warrant further research assessing Sia as a biomarker of severe dengue disease.
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Affiliation(s)
- Diego A Espinosa
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
| | - P Robert Beatty
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Henry Puerta-Guardo
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
| | - M Nurul Islam
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - John T Belisle
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Rushika Perera
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
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29
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Turner JS, Benet ZL, Grigorova IL. Signals 1, 2 and B cell fate or: Where, when and for how long? Immunol Rev 2020; 296:9-23. [DOI: 10.1111/imr.12865] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 04/01/2020] [Accepted: 04/28/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Jackson S. Turner
- Department of Microbiology and Immunology University of Michigan Medical School Ann Arbor MichiganUSA
| | - Zachary L. Benet
- Department of Microbiology and Immunology University of Michigan Medical School Ann Arbor MichiganUSA
| | - Irina L. Grigorova
- Department of Microbiology and Immunology University of Michigan Medical School Ann Arbor MichiganUSA
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30
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Honigfort DJ, Zhang MH, Verespy S, Godula K. Engineering of spectator glycocalyx structures to evaluate molecular interactions at crowded cellular boundaries. Faraday Discuss 2020; 219:138-153. [PMID: 31313786 DOI: 10.1039/c9fd00024k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the mucosal epithelium, the cellular glycocalyx can project tens to hundreds of nanometers into the extracellular space, erecting a physical barrier that provides protective functions, mediates the exchange of nutrients and regulates cellular interactions. Little is understood about how the physical properties of the mucosal glycocalyx influence molecular recognition at the cellular boundary. Here, we report the synthesis of PEG-based glycopolymers with tunable glycan composition, which approximate the extended architecture of mucin glycoproteins, and tether them to the plasma membranes of red blood cells (RBC) to construct an artificial mucin brush-like glycocalyx. We evaluated the association of two lectins, ConA and SNA, with their endogenous glycan ligands on the surface of the remodelled cells. The extended glycocalyx provided protection against agglutination of RBCs by both lectins; however, the rate and magnitude of ConA binding were attenuated to a greater degree in the presence of the glycopolymer spectators compared to those measured for SNA. The different sensitivity of ConA and SNA to glycocalyx crowding likely arises from the distinct presentation of their mannoside and sialoside receptors, respectively, within the native RBC glycocalyx.
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Affiliation(s)
- Daniel J Honigfort
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.
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31
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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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32
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Cytoplasmic glycoengineering enables biosynthesis of nanoscale glycoprotein assemblies. Nat Commun 2019; 10:5403. [PMID: 31776333 PMCID: PMC6881330 DOI: 10.1038/s41467-019-13283-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022] Open
Abstract
Glycosylation of proteins profoundly impacts their physical and biological properties. Yet our ability to engineer novel glycoprotein structures remains limited. Established bacterial glycoengineering platforms require secretion of the acceptor protein to the periplasmic space and preassembly of the oligosaccharide substrate as a lipid-linked precursor, limiting access to protein and glycan substrates respectively. Here, we circumvent these bottlenecks by developing a facile glycoengineering platform that operates in the bacterial cytoplasm. The Glycoli platform leverages a recently discovered site-specific polypeptide glycosyltransferase together with variable glycosyltransferase modules to synthesize defined glycans, of bacterial or mammalian origin, directly onto recombinant proteins in the E. coli cytoplasm. We exploit the cytoplasmic localization of this glycoengineering platform to generate a variety of multivalent glycostructures, including self-assembling nanomaterials bearing hundreds of copies of the glycan epitope. This work establishes cytoplasmic glycoengineering as a powerful platform for producing glycoprotein structures with diverse future biomedical applications. Established bacterial glycoengineering platforms limit access to protein and glycan substrates. Here the authors design a cytoplasmic protein glycosylation system, Glycoli, to generate a variety of multivalent glycostructures.
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33
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Enterina JR, Jung J, Macauley MS. Coordinated roles for glycans in regulating the inhibitory function of CD22 on B cells. Biomed J 2019; 42:218-232. [PMID: 31627864 PMCID: PMC6818156 DOI: 10.1016/j.bj.2019.07.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/19/2019] [Accepted: 07/26/2019] [Indexed: 01/17/2023] Open
Abstract
CD22 is an inhibitory B cell co-receptor that recognizes sialic acid-containing glycoconjugates as ligands. Interactions with its glycan ligands are key to regulating the ability of CD22 to modulate B cell function, the most widely explored of which is antagonizing B cell receptor (BCR) signaling. Most importantly, interactions of CD22 with ligands on the same cell (cis) control the organization of CD22 on the cell surface, which minimizes co-localization with the BCR. In contrast with the modest ability of CD22 to intrinsically dampen BCR signaling, glycan ligands presented on another cell (trans) along with an antigen drawn CD22 and the BCR together within an immunological synapse, strongly inhibiting BCR signaling. New concepts are emerging for how CD22 controls B cell function, such as changes in glycosylation at different stages of B cell differentiation, specifically on GC B cells. Related to these changes, new players, such galectin-9, have been discovered that regulate cell surface nanoclusters of CD22. Roles of glycan ligands in controlling CD22 are the primary focus of this review as we highlight the ability of CD22 to modulate B cell function.
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Affiliation(s)
- Jhon R Enterina
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Jaesoo Jung
- Department of Chemistry, University of Alberta, Edmonton, Canada
| | - Matthew S Macauley
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada; Department of Chemistry, University of Alberta, Edmonton, Canada.
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34
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Altman MO, Gagneux P. Absence of Neu5Gc and Presence of Anti-Neu5Gc Antibodies in Humans-An Evolutionary Perspective. Front Immunol 2019; 10:789. [PMID: 31134048 PMCID: PMC6524697 DOI: 10.3389/fimmu.2019.00789] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 03/25/2019] [Indexed: 12/31/2022] Open
Abstract
The glycocalyx of human cells differs from that of many other mammals by the lack of the sialic acid N-glycolylneuraminic acid (Neu5Gc) and increased abundance of its precursor N-acetylneuraminic acid (Neu5Ac). Most humans also have circulating antibodies specifically targeting the non-human sialic acid Neu5Gc. Recently, several additional mammalian species have been found to also lack Neu5Gc. In all cases, loss-of-function mutations in the gene encoding the sialic acid-modifying enzyme CMAH are responsible for the drastic change in these species. Unlike other glycan antigens, Neu5Gc apparently cannot be produced by microbes, raising the question about the origin of these antibodies in humans. Dietary exposure and presentation on bacteria coating themselves with Neu5Gc from the diet are distinct possibilities. However, the majority of the non-human species that lack Neu5Gc do not consume diets rich in Neu5Gc, making it unlikely that they will have been immunized against this sialic acid. A notable exception are mustelids (ferrets, martens and their relatives) known for preying on various small mammal species rich in Neu5Gc. No studies exist on levels of anti-Neu5Gc antibodies in non-human species. Evolutionary scenarios for the repeated, independent fixation of CMAH loss-of-function mutations at various time points in the past include strong selection by parasites, especially enveloped viruses, stochastic effects of genetic drift, and directional selection via female immunity to paternal Neu5Gc. Convergent evolution of losses of the vertebrate-specific self-glycan Neu5Gc are puzzling and may represent a prominent way in which glycans become agents of evolutionary change in their own right. Such change may include the reconfiguration of innate immune lectins that use self-sialic acids as recognition patterns.
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Affiliation(s)
- Meghan O Altman
- Department of Pathology, Biomedical Research and Training Facility 2, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, United States
| | - Pascal Gagneux
- Department of Pathology, Biomedical Research and Training Facility 2, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, United States.,Department of Anthropology, University of California, San Diego, La Jolla, CA, United States
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35
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The serum SA levels are significantly increased in sepsis but decreased in cirrhosis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 162:335-348. [PMID: 30905461 DOI: 10.1016/bs.pmbts.2019.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most of proteins in human blood circulation are glycoproteins with one or more covalently linked N- or O-linked glycans. Sialic acid (SA) generally occurs as the terminal monosaccharide on the glycans. SA in glycoproteins modulates a wide range of physiological and pathological processes and has been routinely measured in hospital since 1950s. Increased serum SA levels have been associated with different types of cancers. However, a systematic comparison of the serum SA levels in different types of human diseases has not been reported. In current study, 160,537 clinical lab test results of serum SA levels from healthy individuals and patients with 64 different types of diseases during the past 5 years in our hospital were retrieved and analyzed. Based on the mean (SD), median, and p (-Log10p) values, we found that patients suffering 55 different types of cancer and noncancer diseases such as sepsis, pancreatitis, bone cancer, rheumatoid arthritis, pancreatic cancer, and encephalitis had significantly (p<0.05, -Log10p>1.30) increased median serum SA levels whereas patients suffering hepatic encephalopathy, cirrhosis, renal cyst, and hepatitis had significantly decreased median serum SA levels compared to that of healthy controls. Moreover, the greatest increase in the mean (SD) and -Log10p values was observed in sepsis and pancreatitis, respectively, but not in cancers. Thus, the regulations of serum SA levels were much more complicated than previously assumed. Understanding the molecular mechanisms behind these observations would make serum SA a useful biomarker to facilitate personalized diagnosis and treatment for patients with different diseases.
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36
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Wei M, Wang PG. Desialylation in physiological and pathological processes: New target for diagnostic and therapeutic development. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 162:25-57. [PMID: 30905454 DOI: 10.1016/bs.pmbts.2018.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Desialylation is a pivotal part of sialic acid metabolism, which initiates the catabolism of glycans by removing the terminal sialic acid residues on glycans, thereby modulating the structure and functions of glycans, glycoproteins, or glycolipids. The functions of sialic acids have been well recognized, whereas the function of desialylation process is underappreciated or largely ignored. However, accumulating evidence demonstrates that desialylation plays an important role in a variety of physiological and pathological processes. This chapter summarizes the current knowledge pertaining to desialylation in a variety of physiological and pathological processes, with a focus on the underlying molecular mechanisms. The potential of targeting desialylation process for diagnostic and therapeutic development is also discussed.
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Affiliation(s)
- Mohui Wei
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States.
| | - Peng George Wang
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, United States
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37
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Meyer SJ, Linder AT, Brandl C, Nitschke L. B Cell Siglecs-News on Signaling and Its Interplay With Ligand Binding. Front Immunol 2018; 9:2820. [PMID: 30559744 PMCID: PMC6286995 DOI: 10.3389/fimmu.2018.02820] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/15/2018] [Indexed: 12/11/2022] Open
Abstract
CD22 and Siglec-G are members of the Siglec family. Both are inhibitory co-receptors on the surface of B cells and inhibit B-cell receptor induced signaling, characterized by inhibition of the calcium mobilization and cellular activation. CD22 functions predominantly as an inhibitor on conventional B cells, while Siglec-G is an important inhibitor on the B1a-cell subset. These two B-cell Siglecs do not only inhibit initial signaling, but also have an important function in preventing autoimmunity, as double deficient mice develop a lupus-like phenotype with age. Siglecs are characterized by their conserved ability to bind terminal sialic acid of glycans on the cell surface, which is important to regulate the inhibitory role of Siglecs. While CD22 binds α2,6-linked sialic acids, Siglec-G can bind both α2,6-linked and α2,3-linked sialic acids. Interestingly, ligand binding is differentially regulating the ability of CD22 and Siglec-G to control B-cell activation. Within the last years, quite a few studies focused on the different functions of B-cell Siglecs and the interplay of ligand binding and signal inhibition. This review summarizes the role of CD22 and Siglec-G in regulating B-cell receptor signaling, membrane distribution with the importance of ligand binding, preventing autoimmunity and the role of CD22 beyond the naïve B-cell stage. Additionally, this review article features the long time discussed interaction between CD45 and CD22 with highlighting recent data, as well as the interplay between CD22 and Galectin-9 and its influence on B-cell receptor signaling. Moreover, therapeutical approaches targeting human CD22 will be elucidated.
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Affiliation(s)
- Sarah J Meyer
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Alexandra T Linder
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Carolin Brandl
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Lars Nitschke
- Division of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
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38
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SLAM family receptors in natural killer cells - Mediators of adhesion, activation and inhibition via cis and trans interactions. Clin Immunol 2018; 204:37-42. [PMID: 30359773 DOI: 10.1016/j.clim.2018.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 02/06/2023]
Abstract
SLAM family receptors are important for the fine-tuning of immune reactions. Their expression is restricted to cells of hematopoietic origin and most SLAM family receptors are their own ligand. Here we review how these receptors are involved in regulating the functions of Natural Killer (NK) cells. We discuss that promoting cellular adhesion may be a main function of SLAM family receptors in NK cells. The homophilic interactions of SLAM family receptors can not only occur in trans between different cells, but also in cis on the surface of the same cell. This cis interaction additionally modulates the function of the receptors and subsequently affects the activities of NK cells. Finally, SLAM-family receptors can also mediate inhibitory signals under certain conditions. These inhibitory signals can contribute to the functional maturation of NK cells during NK cell education. Therefore, SLAM family receptors are critically involved in many aspects of NK cell functionality.
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39
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Clark EA, Giltiay NV. CD22: A Regulator of Innate and Adaptive B Cell Responses and Autoimmunity. Front Immunol 2018; 9:2235. [PMID: 30323814 PMCID: PMC6173129 DOI: 10.3389/fimmu.2018.02235] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022] Open
Abstract
CD22 (Siglec 2) is a receptor predominantly restricted to B cells. It was initially characterized over 30 years ago and named “CD22” in 1984 at the 2nd International workshop in Boston (1). Several excellent reviews have detailed CD22 functions, CD22-regulated signaling pathways and B cell subsets regulated by CD22 or Siglec G (2–4). This review is an attempt to highlight recent and possibly forgotten findings. We also describe the role of CD22 in autoimmunity and the great potential for CD22-based immunotherapeutics for the treatment of autoimmune diseases such as systemic lupus erythematosus (SLE).
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Affiliation(s)
- Edward A Clark
- Department of Immunology, University of Washington, Seattle, WA, United States.,Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Natalia V Giltiay
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA, United States
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40
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Özgör L, Meyer SJ, Korn M, Terörde K, Nitschke L. Sialic Acid Ligand Binding of CD22 and Siglec-G Determines Distinct B Cell Functions but Is Dispensable for B Cell Tolerance Induction. THE JOURNAL OF IMMUNOLOGY 2018; 201:2107-2116. [DOI: 10.4049/jimmunol.1800296] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/27/2018] [Indexed: 12/20/2022]
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Paul A, Padler-Karavani V. Evolution of sialic acids: Implications in xenotransplant biology. Xenotransplantation 2018; 25:e12424. [PMID: 29932472 PMCID: PMC6756921 DOI: 10.1111/xen.12424] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022]
Abstract
All living cells are covered with a dense “sugar-coat” of carbohydrate chains (glycans) conjugated to proteins and lipids. The cell surface glycome is determined by a non-template driven process related to the collection of enzymes that assemble glycans in a sequential manner. In mammals, many of these glycans are topped with sialic acids (Sia), a large family of acidic sugars. The “Sialome” is highly diverse owing to various Sia types, linkage to underlying glycans, range of carriers, and complex spatial organization. Presented at the front of cells, Sia play a major role in immunity and recognition of “self” versus “non-self,” largely mediated by the siglecs family of Sia-binding host receptors. Albeit many mammalian pathogens have evolved to hijack this recognition system to avoid host immune attack, presenting a fascinating host-pathogen evolutionary arms race. Similarly, cancer cells exploit Sia for their own survival and propagation. As part of this ongoing fitness, humans lost the ability to synthesize the Sia type N-glycolylneuraminic acid (Neu5Gc), in contrast to other mammals. While this loss had provided an advantage against certain pathogens, humans are continuously exposed to Neu5Gc through mammalian-derived diet (eg, red meat), consequently generating a complex immune response against it. Circulating anti-Neu5Gc antibodies together with Neu5Gc on some human tissues mediate chronic inflammation “xenosialitis” that exacerbate various human diseases (eg, cancer and atherosclerosis). Similarly, Neu5Gc-containing xenografts are exposed to human anti-Neu5Gc antibodies with implications to sustainability. This review aimed to provide a glimpse into the evolution of Sia and their implications to xenotransplantation.
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Affiliation(s)
- Anu Paul
- Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Vered Padler-Karavani
- Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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42
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Huang ML, Purcell SC, Verespy S, Wang Y, Godula K. Glycocalyx scaffolding with synthetic nanoscale glycomaterials. Biomater Sci 2018; 5:1537-1540. [PMID: 28616946 DOI: 10.1039/c7bm00289k] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We report a method for programming complexity into the glycocalyx of live cells. Via a combination of glycomaterial synthesis and membrane remodeling, we have engineered cells to display native-like, mixed sialoglycan populations, while confining the activity of each glycan into a specific nanoscale presentation.
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Affiliation(s)
- Mia L Huang
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA, USA.
| | - Sean C Purcell
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA, USA.
| | - Stephen Verespy
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA, USA.
| | - Yinan Wang
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA, USA.
| | - Kamil Godula
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0358, La Jolla, CA, USA.
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43
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Lynch K, Treacy O, Gerlach JQ, Annuk H, Lohan P, Cabral J, Joshi L, Ryan AE, Ritter T. Regulating Immunogenicity and Tolerogenicity of Bone Marrow-Derived Dendritic Cells through Modulation of Cell Surface Glycosylation by Dexamethasone Treatment. Front Immunol 2017; 8:1427. [PMID: 29163502 PMCID: PMC5670353 DOI: 10.3389/fimmu.2017.01427] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/13/2017] [Indexed: 12/15/2022] Open
Abstract
Dendritic cellular therapies and dendritic cell vaccines show promise for the treatment of autoimmune diseases, the prolongation of graft survival in transplantation, and in educating the immune system to fight cancers. Cell surface glycosylation plays a crucial role in the cell–cell interaction, uptake of antigens, migration, and homing of DCs. Glycosylation is known to change with environment and the functional state of DCs. Tolerogenic DCs (tDCs) are commonly generated using corticosteroids including dexamethasone, however, to date, little is known on how corticosteroid treatment alters glycosylation and what functional consequences this may have. Here, we present a comprehensive profile of rat bone marrow-derived dendritic cells, examining their cell surface glycosylation profile before and after Dexa treatment as resolved by both lectin microarrays and lectin-coupled flow cytometry. We further examine the functional consequences of altering cell surface glycosylation on immunogenicity and tolerogenicity of DCs. Dexa treatment of rat DCs leads to profoundly reduced expression of markers of immunogenicity (MHC I/II, CD80, CD86) and pro-inflammatory molecules (IL-6, IL-12p40, inducible nitric oxide synthase) indicating a tolerogenic phenotype. Moreover, by comprehensive lectin microarray profiling and flow cytometry analysis, we show that sialic acid (Sia) is significantly upregulated on tDCs after Dexa treatment, and that this may play a vital role in the therapeutic attributes of these cells. Interestingly, removal of Sia by neuraminidase treatment increases the immunogenicity of immature DCs and also leads to increased expression of pro-inflammatory cytokines while tDCs are moderately protected from this increase in immunogenicity. These findings may have important implications in strategies aimed at increasing tolerogenicity where it is advantageous to reduce immune activation over prolonged periods. These findings are also relevant in therapeutic strategies aimed at increasing the immunogenicity of cells, for example, in the context of tumor specific immunotherapies.
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Affiliation(s)
- Kevin Lynch
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
| | - Oliver Treacy
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
| | - Jared Q Gerlach
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland.,Glycoscience Group, NCBES National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Heidi Annuk
- Glycoscience Group, NCBES National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Paul Lohan
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
| | - Joana Cabral
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
| | - Lokesh Joshi
- Glycoscience Group, NCBES National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Aideen E Ryan
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland.,Discipline of Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland
| | - Thomas Ritter
- School of Medicine, Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
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Ereño-Orbea J, Sicard T, Cui H, Mazhab-Jafari MT, Benlekbir S, Guarné A, Rubinstein JL, Julien JP. Molecular basis of human CD22 function and therapeutic targeting. Nat Commun 2017; 8:764. [PMID: 28970495 PMCID: PMC5624926 DOI: 10.1038/s41467-017-00836-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/28/2017] [Indexed: 12/13/2022] Open
Abstract
CD22 maintains a baseline level of B-cell inhibition to keep humoral immunity in check. As a B-cell-restricted antigen, CD22 is targeted in therapies against dysregulated B cells that cause autoimmune diseases and blood cancers. Here we report the crystal structure of human CD22 at 2.1 Å resolution, which reveals that specificity for α2-6 sialic acid ligands is dictated by a pre-formed β-hairpin as a unique mode of recognition across sialic acid-binding immunoglobulin-type lectins. The CD22 ectodomain adopts an extended conformation that facilitates concomitant CD22 nanocluster formation on B cells and binding to trans ligands to avert autoimmunity in mammals. We structurally delineate the CD22 site targeted by the therapeutic antibody epratuzumab at 3.1 Å resolution and determine a critical role for CD22 N-linked glycosylation in antibody engagement. Our studies provide molecular insights into mechanisms governing B-cell inhibition and valuable clues for the design of immune modulators in B-cell dysfunction.The B-cell-specific co-receptor CD22 is a therapeutic target for depleting dysregulated B cells. Here the authors structurally characterize the ectodomain of CD22 and present its crystal structure with the bound therapeutic antibody epratuzumab, which gives insights into the mechanism of inhibition of B-cell activation.
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Affiliation(s)
- June Ereño-Orbea
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4
| | - Taylor Sicard
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada, M5S 1A8
| | - Hong Cui
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4
| | - Mohammad T Mazhab-Jafari
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4
| | - Samir Benlekbir
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4
| | - Alba Guarné
- Department of Biochemistry and Biomedical Science, McMaster University, Hamilton, ON, Canada, L8S 4L8
| | - John L Rubinstein
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada, M5S 1A8
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, M5G 1L7
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, M5G 0A4.
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada, M5S 1A8.
- Department of Immunology, University of Toronto, Toronto, ON, Canada, M5S 1A8.
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Bednar KJ, Shanina E, Ballet R, Connors EP, Duan S, Juan J, Arlian BM, Kulis MD, Butcher EC, Fung-Leung WP, Rao TS, Paulson JC, Macauley MS. Human CD22 Inhibits Murine B Cell Receptor Activation in a Human CD22 Transgenic Mouse Model. THE JOURNAL OF IMMUNOLOGY 2017; 199:3116-3128. [PMID: 28972089 DOI: 10.4049/jimmunol.1700898] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/28/2017] [Indexed: 01/12/2023]
Abstract
CD22, a sialic acid-binding Ig-type lectin (Siglec) family member, is an inhibitory coreceptor of the BCR with established roles in health and disease. The restricted expression pattern of CD22 on B cells and most B cell lymphomas has made CD22 a therapeutic target for B cell-mediated diseases. Models to better understand how in vivo targeting of CD22 translates to human disease are needed. In this article, we report the development of a transgenic mouse expressing human CD22 (hCD22) in B cells and assess its ability to functionally substitute for murine CD22 (mCD22) for regulation of BCR signaling, Ab responses, homing, and tolerance. Expression of hCD22 on transgenic murine B cells is comparable to expression on human primary B cells, and it colocalizes with mCD22 on the cell surface. Murine B cells expressing only hCD22 have identical calcium (Ca2+) flux responses to anti-IgM as mCD22-expressing wild-type B cells. Furthermore, hCD22 transgenic mice on an mCD22-/- background have restored levels of marginal zone B cells and Ab responses compared with deficiencies observed in CD22-/- mice. Consistent with these observations, hCD22 transgenic mice develop normal humoral responses in a peanut allergy oral sensitization model. Homing of B cells to Peyer's patches was partially rescued by expression of hCD22 compared with CD22-/- B cells, although not to wild-type levels. Notably, Siglec-engaging antigenic liposomes formulated with an hCD22 ligand were shown to prevent B cell activation, increase cell death, and induce tolerance in vivo. This hCD22 transgenic mouse will be a valuable model for investigating the function of hCD22 and preclinical studies targeting hCD22.
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Affiliation(s)
- Kyle J Bednar
- Immunology Team, Janssen Research and Development, LLC, Raritan, NJ 08869.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Elena Shanina
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Romain Ballet
- Laboratory of Immunology and Vascular Biology, Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305.,Palo Alto Veterans Institute for Research, Palo Alto, CA 94304.,The Center for Molecular Biology and Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | - Edward P Connors
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Shiteng Duan
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037.,Department of Immunology and Microbial Sciences, The Scripps Research Institute; La Jolla, CA 92037; and
| | - Joana Juan
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Britni M Arlian
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037.,Department of Immunology and Microbial Sciences, The Scripps Research Institute; La Jolla, CA 92037; and
| | - Michael D Kulis
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Eugene C Butcher
- Laboratory of Immunology and Vascular Biology, Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305.,Palo Alto Veterans Institute for Research, Palo Alto, CA 94304.,The Center for Molecular Biology and Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | | | - Tadimeti S Rao
- Immunology Team, Janssen Research and Development, LLC, Raritan, NJ 08869
| | - James C Paulson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037; .,Department of Immunology and Microbial Sciences, The Scripps Research Institute; La Jolla, CA 92037; and
| | - Matthew S Macauley
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037;
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Chang L, Chen YJ, Fan CY, Tang CJ, Chen YH, Low PY, Ventura A, Lin CC, Chen YJ, Angata T. Identification of Siglec Ligands Using a Proximity Labeling Method. J Proteome Res 2017; 16:3929-3941. [DOI: 10.1021/acs.jproteome.7b00625] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Chan-Yo Fan
- Department
of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | | | | | | | | | - Chun-Cheng Lin
- Department
of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | | | - Takashi Angata
- Institute
of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan
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47
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Genetic code asymmetry supports diversity through experimentation with posttranslational modifications. Curr Opin Chem Biol 2017; 41:1-11. [PMID: 28923586 DOI: 10.1016/j.cbpa.2017.08.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/03/2017] [Accepted: 08/26/2017] [Indexed: 12/20/2022]
Abstract
Protein N-glycosylation has been identified in all three domains of life presumably conserved for its early role in glycoprotein folding. However, the N-glycans added to proteins in the secretory pathway of multicellular organisms are remodeling in the Golgi, increasing structural diversity exponentially and adding new layers of functionality in immunity, metabolism and other systems. The branching and elongation of N-glycan chains found on cell surface receptors generates a gradation of affinities for carbohydrate-binding proteins, the galectin, selectin and siglec families. These interactions adapt cellular responsiveness to environmental conditions, but their complexity presents a daunting challenge to drug design. To gain further insight, I review how N-glycans biosynthesis and biophysical properties provide a selective advantage in the form of tunable and ultrasensitive stimulus-response relationships. In addition, the N-glycosylation motif favors step-wise mutational experimentation with sites. Glycoproteins display accelerated evolution during vertebrate radiation, and the encoding asymmetry of NXS/T(X≠P) has left behind phylogenetic evidence suggesting that the genetic code may have been selected to optimize diversity in part through emerging posttranslational modifications.
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48
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Varki A. Are humans prone to autoimmunity? Implications from evolutionary changes in hominin sialic acid biology. J Autoimmun 2017; 83:134-142. [PMID: 28755952 DOI: 10.1016/j.jaut.2017.07.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 07/13/2017] [Accepted: 07/17/2017] [Indexed: 02/06/2023]
Abstract
Given varied intrinsic and extrinsic challenges to the immune system, it is unsurprising that each evolutionary lineage evolves distinctive features of immunoreactivity, and that tolerance mechanisms fail, allowing autoimmunity. Humans appear prone to many autoimmune diseases, with mechanisms both genetic and environmental. Another rapidly evolving biological system involves sialic acids, a family of monosaccharides that are terminal caps on cell surface and secreted molecules of vertebrates, and play multifarious roles in immunity. We have explored multiple genomic changes in sialic acid biology that occurred in human ancestors (hominins), some with implications for enhanced immunoreactivity, and hence for autoimmunity. Human ancestors lost the enzyme synthesizing the common mammalian sialic acid Neu5Gc, with an accumulation of the precursor sialic acid Neu5Ac. Resulting changes include an enhanced reactivity by some immune cells and increased ability of macrophages to kill bacteria, at the cost of increased endotoxin sensitivity. There are also multiple human-specific evolutionary changes in inhibitory and activating Siglecs, immune cell receptors that recognize sialic acids as "self-associated molecular patterns" (SAMPs) to modulate immunity, but can also be hijacked by pathogen molecular mimicry of SAMPs. Altered expression patterns and fixed or polymorphic SIGLEC pseudogenization in humans has modulated both innate and adaptive immunity, sometimes favoring over-reactivity. Meanwhile, dietary intake of Neu5Gc (derived primarily from red meats) allows metabolic incorporation of this non-human molecule into human cells--apparently the first example of "xeno-autoimmunity" involving "xeno-autoantigen" interactions with circulating "xeno-autoantibodies". Taken together, some of these factors may contribute to the apparent human propensity for autoimmunity.
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Affiliation(s)
- Ajit Varki
- Departments of Medicine and Cellular and Molecular Medicine, Glycobiology Research and Training Center (GRTC) and Center for Academic Research and Training in Anthropogeny (CARTA), University of California, San Diego, La Jolla, CA, 92093-0687, USA.
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49
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CD22 is required for formation of memory B cell precursors within germinal centers. PLoS One 2017; 12:e0174661. [PMID: 28346517 PMCID: PMC5367813 DOI: 10.1371/journal.pone.0174661] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/13/2017] [Indexed: 01/17/2023] Open
Abstract
CD22 is a BCR co-receptor that regulates B cell signaling, proliferation and survival and is required for T cell-independent Ab responses. To investigate the role of CD22 during T cell-dependent (TD) Ab responses and memory B cell formation, we analyzed Ag-specific B cell responses generated by wild-type (WT) or CD22-/- B cells following immunization with a TD Ag. CD22-/- B cells mounted normal early Ab responses yet failed to generate either memory B cells or long-lived plasma cells, whereas WT B cells formed both populations. Surprisingly, B cell expansion and germinal center (GC) differentiation were comparable between WT and CD22-/- B cells. CD22-/- B cells, however, were significantly less capable of generating a population of CXCR4hiCD38hi GC B cells, which we propose represent memory B cell precursors within GCs. These results demonstrate a novel role for CD22 during TD humoral responses evident during primary GC formation and underscore that CD22 functions not only during B cell maturation but also during responses to both TD and T cell-independent antigens.
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50
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Kreuzmann D, Horstkorte R, Kohla G, Kannicht C, Bennmann D, Thate A, Bork K. Increased Polysialylation of the Neural Cell Adhesion Molecule in a Transgenic Mouse Model of Sialuria. Chembiochem 2017; 18:1188-1193. [PMID: 27966821 DOI: 10.1002/cbic.201600580] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Indexed: 12/12/2022]
Abstract
Sialuria is a rare autosomal dominant disorder of mammalian metabolism, caused by defective feedback inhibition of the UDP-N-acetylglucosamine-2-epimerase N-acetylmannosamine kinase (GNE), the key enzyme of sialic acid biosynthesis. Sialuria is characterized by overproduction of free sialic acid in the cell cytoplasm. Patients exhibit vastly increased urinary excretion of sialic acid and show differently pronounced developmental delays. The physiopathology of sialuria is not well understood. Here we established a transgenic mouse line that expresses GNE containing the sialuria mutation R263L, in order to investigate the influence of an altered sialic acid concentration on the organism. The transgenic mice that expressed the mutated RNA excreted up to 400 times more N-acetylneuraminic acid than wild-type mice. Additionally, we found higher sialic acid concentration in the brain cytoplasm. Analyzing the (poly)sialylation of neural cell adhesion molecule (NCAM) revealed increased polysialylation in brains of transgenic mice compared to wild-type. However, we found only minor changes in membrane-bound sialylation in various organs but, surprisingly, a significant increase in surface sialylation on leukocytes. Our results suggest that the intracellular sialic acid concentration regulates polysialylation on NCAM in vivo; this could play a role in the manifestation of the developmental delays in sialuria patients.
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Affiliation(s)
- Denise Kreuzmann
- Institute for Physiological Chemistry, Martin-Luther-Universität Halle-Wittenberg, Hollystrasse 1, 06114, Halle/Saale, Germany
| | - Rüdiger Horstkorte
- Institute for Physiological Chemistry, Martin-Luther-Universität Halle-Wittenberg, Hollystrasse 1, 06114, Halle/Saale, Germany
| | - Guido Kohla
- Octapharma Biopharmaceuticals GmbH, Molecular Biochemistry, Walther-Nernst-Strasse 3, 12489, Berlin, Germany
| | - Christoph Kannicht
- Octapharma Biopharmaceuticals GmbH, Molecular Biochemistry, Walther-Nernst-Strasse 3, 12489, Berlin, Germany
| | - Dorit Bennmann
- Institute for Physiological Chemistry, Martin-Luther-Universität Halle-Wittenberg, Hollystrasse 1, 06114, Halle/Saale, Germany
| | - Annett Thate
- Institute for Physiological Chemistry, Martin-Luther-Universität Halle-Wittenberg, Hollystrasse 1, 06114, Halle/Saale, Germany
| | - Kaya Bork
- Institute for Physiological Chemistry, Martin-Luther-Universität Halle-Wittenberg, Hollystrasse 1, 06114, Halle/Saale, Germany
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