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Struijf EM, De la O Becerra KI, Ruyken M, de Haas CJC, van Oosterom F, Siere DY, van Keulen JE, Heesterbeek DAC, Dolk E, Heukers R, Bardoel BW, Gros P, Rooijakkers SHM. Inhibition of cleavage of human complement component C5 and the R885H C5 variant by two distinct high affinity anti-C5 nanobodies. J Biol Chem 2023; 299:104956. [PMID: 37356719 PMCID: PMC10374974 DOI: 10.1016/j.jbc.2023.104956] [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: 03/06/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/27/2023] Open
Abstract
The human complement system plays a crucial role in immune defense. However, its erroneous activation contributes to many serious inflammatory diseases. Since most unwanted complement effector functions result from C5 cleavage into C5a and C5b, development of C5 inhibitors, such as clinically approved monoclonal antibody eculizumab, are of great interest. Here, we developed and characterized two anti-C5 nanobodies, UNbC5-1 and UNbC5-2. Using surface plasmon resonance, we determined a binding affinity of 119.9 pM for UNbC5-1 and 7.7 pM for UNbC5-2. Competition experiments determined that the two nanobodies recognize distinct epitopes on C5. Both nanobodies efficiently interfered with C5 cleavage in a human serum environment, as they prevented red blood cell lysis via membrane attack complexes (C5b-9) and the formation of chemoattractant C5a. The cryo-EM structure of UNbC5-1 and UNbC5-2 in complex with C5 (3.6 Å resolution) revealed that the binding interfaces of UNbC5-1 and UNbC5-2 overlap with known complement inhibitors eculizumab and RaCI3, respectively. UNbC5-1 binds to the MG7 domain of C5, facilitated by a hydrophobic core and polar interactions, and UNbC5-2 interacts with the C5d domain mostly by salt bridges and hydrogen bonds. Interestingly, UNbC5-1 potently binds and inhibits C5 R885H, a genetic variant of C5 that is not recognized by eculizumab. Altogether, we identified and characterized two different, high affinity nanobodies against human C5. Both nanobodies could serve as diagnostic and/or research tools to detect C5 or inhibit C5 cleavage. Furthermore, the residues targeted by UNbC5-1 hold important information for therapeutic inhibition of different polymorphic variants of C5.
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Affiliation(s)
- Eva M Struijf
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Karla I De la O Becerra
- Structural Biochemistry Group, Faculty of Science, Department of Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Maartje Ruyken
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Carla J C de Haas
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Fleur van Oosterom
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Danique Y Siere
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Joanne E van Keulen
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Dani A C Heesterbeek
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | | | - Bart W Bardoel
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Piet Gros
- Structural Biochemistry Group, Faculty of Science, Department of Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Suzan H M Rooijakkers
- Department Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
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2
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Opstrup KV, Bennike TB, Christiansen G, Birkelund S. Complement killing of clinical Klebsiella pneumoniae isolates is serum concentration dependent. Microbes Infect 2022; 25:105074. [PMID: 36336240 DOI: 10.1016/j.micinf.2022.105074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
Klebsiella pneumoniae is an opportunistic gram-negative pathogen causing serious infections, including sepsis. In plasma, activation of the complement cascades is important for killing bacteria. Thirty clinical Klebsiella spp. blood isolates were analyzed for serum susceptibility in 75% normal human serum (NHS). Twenty-two were serum resistant and eight were serum sensitive, and subsequently tested in 5-75% NHS. Two isolates were killed in 5% and the remaining six in 50%-75% NHS. The two 5% sensitive isolates showed binding of complement (C)4 and C3 in 5% NHS with formation of membrane attack complex (MAC). Inhibition of the classical/lectin mediated pathways (CP/LP) using a C4 specific nanobody, hC4Nb8, led to survival of both isolates in 5% NHS. Using nanobody hC3Nb1, inhibiting the alternative pathway (AP), the isolates were killed in 5% NHS, and amplification of the CP/LP by AP was not necessary for killing. Sole AP killing of these isolates when inhibiting CP/LP with hC4Nb8 was observed in 50% NHS, stressing the concentration dependent functionality of AP. For the less sensitive isolates, killing required activation of CP/LP and AP demonstrated by inhibition with nanobodies. AP inhibition resulted in no C3 deposition on the serum resistant isolate, supporting that AP was the sole activation pathway.
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Affiliation(s)
- Katharina V Opstrup
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark
| | - Tue B Bennike
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark
| | - Gunna Christiansen
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark
| | - Svend Birkelund
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark.
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Jensen RK, Pedersen H, Lorentzen J, Laursen NS, Vorup-Jensen T, Andersen GR. Structural insights into the function-modulating effects of nanobody binding to the integrin receptor α Mβ 2. J Biol Chem 2022; 298:102168. [PMID: 35738398 PMCID: PMC9287160 DOI: 10.1016/j.jbc.2022.102168] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 01/12/2023] Open
Abstract
The integrin receptor αMβ2 mediates phagocytosis of complement-opsonized objects, adhesion to the extracellular matrix, and transendothelial migration of leukocytes. However, the mechanistic aspects of αMβ2 signaling upon ligand binding are unclear. Here, we present the first atomic structure of the human αMβ2 headpiece fragment in complex with the nanobody (Nb) hCD11bNb1 at a resolution of 3.2 Å. We show that the receptor headpiece adopts the closed conformation expected to exhibit low ligand affinity. The crystal structure indicates that in the R77H αM variant, associated with systemic lupus erythematosus, the modified allosteric relationship between ligand binding and integrin outside–inside signaling is due to subtle conformational effects transmitted over a distance of 40 Å. Furthermore, we found the Nb binds to the αI domain of the αM subunit in an Mg2+-independent manner with low nanomolar affinity. Biochemical and biophysical experiments with purified proteins demonstrated that the Nb acts as a competitive inhibitor through steric hindrance exerted on the thioester domain of complement component iC3b attempting to bind the αM subunit. Surprisingly, we show that the Nb stimulates the interaction of cell-bound αMβ2 with iC3b, suggesting that it may represent a novel high-affinity proteinaceous αMβ2-specific agonist. Taken together, our data suggest that the iC3b–αMβ2 complex may be more dynamic than predicted from the crystal structure of the core complex. We propose a model based on the conformational spectrum of the receptor to reconcile these observations regarding the functional consequences of hCD11bNb1 binding to αMβ2.
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Affiliation(s)
- Rasmus K Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Henrik Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Josefine Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
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Laich A, Patel H, Zarantonello A, Sim R, Inal J. C2 by-pass: cross-talk between the complement classical and alternative pathways. Immunobiology 2022; 227:152225. [DOI: 10.1016/j.imbio.2022.152225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 04/12/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022]
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De la O Becerra KI, Oosterheert W, van den Bos RM, Xenaki KT, Lorent JH, Ruyken M, Schouten A, Rooijakkers SHM, van Bergen En Henegouwen PMP, Gros P. Multifaceted Activities of Seven Nanobodies against Complement C4b. THE JOURNAL OF IMMUNOLOGY 2022; 208:2207-2219. [PMID: 35428691 PMCID: PMC9047069 DOI: 10.4049/jimmunol.2100647] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022]
Abstract
Cleavage of the mammalian plasma protein C4 into C4b initiates opsonization, lysis, and clearance of microbes and damaged host cells by the classical and lectin pathways of the complement system. Dysregulated activation of C4 and other initial components of the classical pathway may cause or aggravate pathologies, such as systemic lupus erythematosus, Alzheimer disease, and schizophrenia. Modulating the activity of C4b by small-molecule or protein-based inhibitors may represent a promising therapeutic approach for preventing excessive inflammation and damage to host cells and tissue. Here, we present seven nanobodies, derived from llama (Lama glama) immunization, that bind to human C4b (Homo sapiens) with high affinities ranging from 3.2 nM to 14 pM. The activity of the nanobodies varies from no to complete inhibition of the classical pathway. The inhibiting nanobodies affect different steps in complement activation, in line with blocking sites for proconvertase formation, C3 substrate binding to the convertase, and regulator-mediated inactivation of C4b. For four nanobodies, we determined single-particle cryo-electron microscopy structures in complex with C4b at 3.4–4 Å resolution. The structures rationalize the observed functional effects of the nanobodies and define their mode of action during complement activation. Thus, we characterized seven anti-C4b nanobodies with diverse effects on the classical pathway of complement activation that may be explored for imaging, diagnostic, or therapeutic applications. Diverse binding properties are revealed for seven nanobodies against C4b. Cryo-electron microscopy structures of C4b–nanobody complexes indicate nanobodies’ modes of action. Nanobodies have therapeutic potential and are useful for labeling studies.
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Affiliation(s)
- Karla I De la O Becerra
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Wout Oosterheert
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Ramon M van den Bos
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Katerina T Xenaki
- Cell Biology, Neurobiology & Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Joseph H Lorent
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands; and
| | - Maartje Ruyken
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Arie Schouten
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | | | | | - Piet Gros
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands;
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Wanner N, Eden T, Liaukouskaya N, Koch-Nolte F. Nanobodies: new avenue to treat kidney disease. Cell Tissue Res 2021; 385:445-456. [PMID: 34131806 PMCID: PMC8205650 DOI: 10.1007/s00441-021-03479-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/24/2021] [Indexed: 12/14/2022]
Abstract
Current therapeutic options for renal diseases are limited, and the search for disease-specific treatments is ongoing. Nanobodies, single-domain antibodies with many advantages over conventional antibodies, provide flexible, easy-to-format biologicals with many possible applications. Here, we discuss the potential use of nanobodies for renal diseases.
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Affiliation(s)
- Nicola Wanner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
| | - Thomas Eden
- Institute of Immunology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Nastassia Liaukouskaya
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Friedrich Koch-Nolte
- Institute of Immunology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
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Zarantonello A, Pedersen H, Laursen NS, Andersen GR. Nanobodies Provide Insight into the Molecular Mechanisms of the Complement Cascade and Offer New Therapeutic Strategies. Biomolecules 2021; 11:biom11020298. [PMID: 33671302 PMCID: PMC7922070 DOI: 10.3390/biom11020298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 01/22/2023] Open
Abstract
The complement system is part of the innate immune response, where it provides immediate protection from infectious agents and plays a fundamental role in homeostasis. Complement dysregulation occurs in several diseases, where the tightly regulated proteolytic cascade turns offensive. Prominent examples are atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria and Alzheimer’s disease. Therapeutic intervention targeting complement activation may allow treatment of such debilitating diseases. In this review, we describe a panel of complement targeting nanobodies that allow modulation at different steps of the proteolytic cascade, from the activation of the C1 complex in the classical pathway to formation of the C5 convertase in the terminal pathway. Thorough structural and functional characterization has provided a deep mechanistic understanding of the mode of inhibition for each of the nanobodies. These complement specific nanobodies are novel powerful probes for basic research and offer new opportunities for in vivo complement modulation.
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Affiliation(s)
- Alessandra Zarantonello
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; (A.Z.); (H.P.)
| | - Henrik Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; (A.Z.); (H.P.)
| | - Nick S. Laursen
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark;
| | - Gregers R. Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; (A.Z.); (H.P.)
- Correspondence: ; Tel.: +45-30256646
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Harwood SL, Nielsen NS, Pedersen H, Kjøge K, Nielsen PK, Andersen GR, Enghild JJ. Substituting the Thiol Ester of Human A2M or C3 with a Disulfide Produces Native Proteins with Altered Proteolysis-Induced Conformational Changes. Biochemistry 2020; 59:4799-4809. [DOI: 10.1021/acs.biochem.0c00803] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Seandean Lykke Harwood
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
- Global Research Technologies, Novo Nordisk A/S, Novo Nordisk Park, 2760 Måløv, Denmark
| | - Nadia Sukusu Nielsen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Henrik Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Katarzyna Kjøge
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Peter Kresten Nielsen
- Global Research Technologies, Novo Nordisk A/S, Novo Nordisk Park, 2760 Måløv, Denmark
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Jan J. Enghild
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
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9
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Ghasemi F, Tessier TM, Gameiro SF, Maciver AH, Cecchini MJ, Mymryk JS. High MHC-II expression in Epstein-Barr virus-associated gastric cancers suggests that tumor cells serve an important role in antigen presentation. Sci Rep 2020; 10:14786. [PMID: 32901107 PMCID: PMC7479113 DOI: 10.1038/s41598-020-71775-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023] Open
Abstract
EBV-associated gastric adenocarcinomas (EBVaGCs) often exhibit better clinical outcomes than EBV negative gastric cancers (GCs), which could be related to their consistent expression of foreign viral antigens. Antigen-presenting cells (APCs) present peptide antigens in the context of the class-II major histocompatibility complex (MHC-II). During inflammatory conditions, epithelial cells express MHC-II and function as accessory APCs. Utilizing RNA-seq data from nearly 400 GC patients, we determined the impact of EBV-status on expression of MHC-II components, genes involved in their regulation, and T-cell co-stimulation. Virtually all MHC-II genes were significantly upregulated in EBVaGCs compared to normal tissues, or other GC subtypes. Genes involved in antigen presentation were also significantly upregulated in EBVaGCs, as were the key MHC-II transcriptional regulators CIITA and RFX5. This was unexpected as the EBV encoded BZLF1 protein can repress CIITA transcription and is expressed in many EBVaGCs. Furthermore, MHC-II upregulation was strongly correlated with elevated intratumoral levels of interferon-gamma. In addition, expression of co-stimulatory molecules involved in T-cell activation and survival was also significantly increased in EBVaGCs. Thus, gastric adenocarcinoma cells may functionally contribute to the highly immunogenic tumor microenvironment observed in EBVaGCs via a previously unappreciated role in interferon-induced antigen presentation.
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Affiliation(s)
- Farhad Ghasemi
- Department of Surgery, Western University, London, ON, N6A 4V2, Canada
| | - Tanner M Tessier
- Department of Microbiology and Immunology, Western University, London, ON, N6A 3K7, Canada
| | - Steven F Gameiro
- Department of Microbiology and Immunology, Western University, London, ON, N6A 3K7, Canada
| | - Allison H Maciver
- Department of Surgery, Western University, London, ON, N6A 4V2, Canada.,Department of Oncology, Western University, London, ON, N6A 3K7, Canada
| | - Matthew J Cecchini
- Department of Pathology and Laboratory Medicine, Western University and London Health Sciences Centre, London, ON, N6A 5C1, Canada
| | - Joe S Mymryk
- Department of Microbiology and Immunology, Western University, London, ON, N6A 3K7, Canada. .,Department of Oncology, Western University, London, ON, N6A 3K7, Canada. .,Department of Otolaryngology, Head & Neck Surgery, Western University, London, ON, N6A 5W9, Canada. .,London Regional Cancer Program, Lawson Health Research Institute, London, ON, N6C 2R5, Canada. .,London Regional Cancer Program, Room A4-837, 790 Commissioners Rd. East, London, ON, N6A 4L6, Canada.
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