1
|
Masson FM, Káradóttir S, van der Lans SPA, Doorduijn DJ, de Haas CJC, Rooijakkers SHM, Bardoel BW. Klebsiella LPS O1-antigen prevents complement-mediated killing by inhibiting C9 polymerization. Sci Rep 2024; 14:20701. [PMID: 39237647 PMCID: PMC11377433 DOI: 10.1038/s41598-024-71487-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 08/28/2024] [Indexed: 09/07/2024] Open
Abstract
The Gram-negative bacterium Klebsiella pneumoniae is an important human pathogen. Its treatment has been complicated by the emergence of multi-drug resistant strains. The human complement system is an important part of our innate immune response that can directly kill Gram-negative bacteria by assembling membrane attack complex (MAC) pores into the bacterial outer membrane. To resist this attack, Gram-negative bacteria can modify their lipopolysaccharide (LPS). Especially the decoration of the LPS outer core with the O-antigen polysaccharide has been linked to increased bacterial survival in serum, but not studied in detail. In this study, we characterized various clinical Klebsiella pneumoniae isolates and show that expression of the LPS O1-antigen correlates with resistance to complement-mediated killing. Mechanistic data reveal that the O1-antigen does not inhibit C3b deposition and C5 conversion. In contrast, we see more efficient formation of C5a, and deposition of C6 and C9 when an O-antigen is present. Further downstream analyses revealed that the O1-antigen prevents correct insertion and polymerization of the final MAC component C9 into the bacterial membrane. Altogether, we show that the LPS O1-antigen is a key determining factor for complement resistance by K. pneumoniae and provide insights into the molecular basis of O1-mediated MAC evasion.
Collapse
Affiliation(s)
- Frerich M Masson
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Salvör Káradóttir
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Dennis J Doorduijn
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Carla J C de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Bart W Bardoel
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
| |
Collapse
|
2
|
Chen BM, Chen E, Lin YC, Tran TTM, Turjeman K, Yang SH, Cheng TL, Barenholz Y, Roffler SR. Liposomes with Low Levels of Grafted Poly(ethylene glycol) Remain Susceptible to Destabilization by Anti-Poly(ethylene glycol) Antibodies. ACS NANO 2024; 18:22122-22138. [PMID: 39119697 PMCID: PMC11342370 DOI: 10.1021/acsnano.4c05409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 08/10/2024]
Abstract
Binding of anti-PEG antibodies to poly(ethylene glycol) (PEG) on the surface of PEGylated liposomal doxorubicin (PLD) in vitro and in rats can activate complement and cause the rapid release of doxorubicin from the liposome interior. Here, we find that irinotecan liposomes (IL) and L-PLD, which have 16-fold lower levels of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)-PEG2000 in their liposome membrane as compared to PLD, generate less complement activation but remain sensitive to destabilization and drug release by anti-PEG antibodies. Complement activation and liposome destabilization correlated with the theoretically estimated number of antibody molecules bound per liposome. Drug release from liposomes proceeded through the alternative complement pathway but was accelerated by the classical complement pathway. In contrast to PLD destabilization by anti-PEG immunoglobulin G (IgG), which proceeded by the insertion of membrane attack complexes in the lipid bilayer of otherwise intact PLD, anti-PEG IgG promoted the fusion of L-PLD, and IL to form unilamellar and oligo-vesicular liposomes. Anti-PEG immunoglobulin M (IgM) induced drug release from all liposomes (PLD, L-PLD, and IL) via the formation of unilamellar and oligo-vesicular liposomes. Anti-PEG IgG destabilized both PLD and L-PLD in rats, indicating that the reduction of PEG levels on liposomes is not an effective approach to prevent liposome destabilization by anti-PEG antibodies.
Collapse
Affiliation(s)
- Bing-Mae Chen
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Even Chen
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Chen Lin
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
- Graduate
Institute of Life Sciences, National Defense
Medical Center, Taipei 11490, Taiwan
| | - Trieu Thi My Tran
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Keren Turjeman
- Department
of Biochemistry and Molecular Biology, Hebrew
University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Shih-Hung Yang
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Tian-Lu Cheng
- Graduate
Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Yechezkel Barenholz
- Department
of Biochemistry and Molecular Biology, Hebrew
University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Steve R. Roffler
- Institute
of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
- Graduate
Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| |
Collapse
|
3
|
Kulkarni DH, Starick M, Aponte Alburquerque R, Kulkarni HS. Local complement activation and modulation in mucosal immunity. Mucosal Immunol 2024; 17:739-751. [PMID: 38838816 DOI: 10.1016/j.mucimm.2024.05.006] [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: 01/01/2024] [Revised: 05/24/2024] [Accepted: 05/29/2024] [Indexed: 06/07/2024]
Abstract
The complement system is an evolutionarily conserved arm of innate immunity, which forms one of the first lines of host response to pathogens and assists in the clearance of debris. A deficiency in key activators/amplifiers of the cascade results in recurrent infection, whereas a deficiency in regulating the cascade predisposes to accelerated organ failure, as observed in colitis and transplant rejection. Given that there are over 60 proteins in this system, it has become an attractive target for immunotherapeutics, many of which are United States Food and Drug Administration-approved or in multiple phase 2/3 clinical trials. Moreover, there have been key advances in the last few years in the understanding of how the complement system operates locally in tissues, independent of its activities in circulation. In this review, we will put into perspective the abovementioned discoveries to optimally modulate the spatiotemporal nature of complement activation and regulation at mucosal surfaces.
Collapse
Affiliation(s)
- Devesha H Kulkarni
- Division of Gastroenterology, Washington University School of Medicine, St. Louis, MO, USA
| | - Marick Starick
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Rafael Aponte Alburquerque
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Hrishikesh S Kulkarni
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
4
|
Turko IV. Quantitative Analysis of Complement Membrane Attack Complex Proteins Associated with Extracellular Vesicles. Proteomes 2024; 12:21. [PMID: 39051239 PMCID: PMC11270256 DOI: 10.3390/proteomes12030021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/05/2024] [Accepted: 07/10/2024] [Indexed: 07/27/2024] Open
Abstract
Extracellular vesicles (EVs) represent a universal mechanism of intercellular communication in normal and pathological conditions. There are reports showing the presence of complement proteins in EV preparations, specifically those that can form a membrane attack complex (MAC). In the present work, we have used a quantitative mass spectrometry method that allows for the measurement of multiple targeted proteins in one experimental run. The quantification of MAC-forming proteins, namely C5b, C6, C7, C8, and C9, in highly purified EVs from normal human plasma revealed the presence of MAC proteins at approximately equal stoichiometry that does not fit the expected stoichiometry of preformed MAC. We concluded that while MAC proteins can be associated with EVs from normal plasma and presumably can be delivered to the recipient cells, there is no evidence that the EVs carry preformed MAC.
Collapse
Affiliation(s)
- Illarion V Turko
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, University of Maryland, Rockville, ML 20850, USA
| |
Collapse
|
5
|
Merle NS, Roumenina LT. The complement system as a target in cancer immunotherapy. Eur J Immunol 2024:e2350820. [PMID: 38996361 DOI: 10.1002/eji.202350820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 06/26/2024] [Accepted: 07/02/2024] [Indexed: 07/14/2024]
Abstract
Malignant cells are part of a complex network within the tumor microenvironment, where their interaction with host cells and soluble mediators, including complement components, is pivotal. The complement system, known for its role in immune defense and homeostasis, exhibits a dual effect on cancer progression. This dichotomy arises from its antitumoral opsonophagocytosis and cytotoxicity versus its protumoral chronic inflammation mediated by the C5a/C5aR1 axis, influencing antitumor T-cell responses. Recent studies have revealed distinct co-expression patterns of complement genes in various cancer types, correlating with prognosis. Notably, some cancers exhibit co-regulated overexpression of complement genes associated with poor prognosis, while others show favorable outcomes. However, significant intra-patient heterogeneity further complicates this classification. Moreover, the involvement of locally produced and intracellular complement proteins adds complexity to the tumor microenvironment dynamics. This review highlights the unique interplay of complement components within different cancers and patient cohorts, showing that "one size does not fit all", for complement in cancer. It summarizes the clinical trials for complement targeting in cancer, emphasizing the need for tailored therapeutic approaches. By elucidating the mechanistic basis of complement's context-dependent role, this review aims to facilitate the development of personalized cancer therapies, ultimately improving patient care and outcomes.
Collapse
Affiliation(s)
- Nicolas S Merle
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
| | - Lubka T Roumenina
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
| |
Collapse
|
6
|
Kulkarni HS. Hexamerization: explaining the original sin of IgG-mediated complement activation in acute lung injury. J Clin Invest 2024; 134:e181137. [PMID: 38828725 PMCID: PMC11142731 DOI: 10.1172/jci181137] [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: 06/05/2024] Open
Abstract
Although antibody-mediated lung damage is a major factor in transfusion-related acute lung injury (ALI), autoimmune lung disease (for example, coatomer subunit α [COPA] syndrome), and primary graft dysfunction following lung transplantation, the mechanism by which antigen-antibody complexes activate complement to induce lung damage remains unclear. In this issue of the JCI, Cleary and colleagues utilized several approaches to demonstrate that IgG forms hexamers with MHC class I alloantibodies. This hexamerization served as a key pathophysiological mechanism in alloimmune lung injury models and was mediated through the classical pathway of complement activation. Additionally, the authors provided avenues for exploring therapeutics for this currently hard-to-treat clinical entity that has several etiologies but a potentially focused mechanism.
Collapse
|
7
|
Aissaoui N, Mills A, Lai-Kee-Him J, Triomphe N, Cece Q, Doucet C, Bonhoure A, Vidal M, Ke Y, Bellot G. Free-Standing DNA Origami Superlattice to Facilitate Cryo-EM Visualization of Membrane Vesicles. J Am Chem Soc 2024; 146:12925-12932. [PMID: 38691507 DOI: 10.1021/jacs.3c07328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Technological breakthroughs in cryo-electron microscopy (cryo-EM) methods open new perspectives for highly detailed structural characterizations of extracellular vesicles (EVs) and synthetic liposome-protein assemblies. Structural characterizations of these vesicles in solution under a nearly native hydrated state are of great importance to decipher cell-to-cell communication and to improve EVs' application as markers in diagnosis and as drug carriers in disease therapy. However, difficulties in preparing holey carbon cryo-EM grids with low vesicle heterogeneities, at low concentration and with kinetic control of the chemical reactions or assembly processes, have limited cryo-EM use in the EV study. We report a straightforward membrane vesicle cryo-EM sample preparation method that assists in circumventing these limitations by using a free-standing DNA-affinity superlattice for covering holey carbon cryo-EM grids. Our approach uses DNA origami to self-assemble to a solution-stable and micrometer-sized ordered molecular template in which structure and functional properties can be rationally controlled. We engineered the template with cholesterol-binding sites to specifically trap membrane vesicles. The advantages of this DNA-cholesterol-affinity lattice (DCAL) include (1) local enrichment of artificial and biological vesicles at low concentration and (2) isolation of heterogeneous cell-derived membrane vesicles (exosomes) from a prepurified pellet of cell culture conditioned medium on the grid.
Collapse
Affiliation(s)
| | - Allan Mills
- Université de Montpellier, CNRS, INSERM, Centre de Biologie Structurale, F-34000 Montpellier, France
| | - Josephine Lai-Kee-Him
- Université de Montpellier, CNRS, INSERM, Centre de Biologie Structurale, F-34000 Montpellier, France
| | - Nicolas Triomphe
- Université de Montpellier, CNRS, INSERM, Centre de Biologie Structurale, F-34000 Montpellier, France
| | - Quentin Cece
- Université Paris Cité, CNRS, CiTCoM, F-75006 Paris, France
| | - Christine Doucet
- Université de Montpellier, CNRS, INSERM, Centre de Biologie Structurale, F-34000 Montpellier, France
| | - Anne Bonhoure
- Université de Montpellier, CNRS, LPHI, F-34000 Montpellier, France
| | - Michel Vidal
- Université de Montpellier, CNRS, LPHI, F-34000 Montpellier, France
| | - Yonggang Ke
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 30322 Atlanta, United States
| | - Gaetan Bellot
- Université de Montpellier, CNRS, INSERM, Centre de Biologie Structurale, F-34000 Montpellier, France
| |
Collapse
|
8
|
Hristodorov D, Lohoff T, Luneborg N, Mulder GJ, Clark SJ. Investing in vision: Innovation in retinal therapeutics and the influence on venture capital investment. Prog Retin Eye Res 2024; 99:101243. [PMID: 38218527 DOI: 10.1016/j.preteyeres.2024.101243] [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: 10/31/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 01/15/2024]
Abstract
Since the groundbreaking approval of the first anti-VEGF therapy in 2004, the retinal therapeutics field has undergone a remarkable transformation, witnessing a surge in novel, disease-modifying therapeutics for a broad spectrum of retinal diseases, extending beyond exudative VEGF-driven conditions. The surge in scientific advancement and the pressing, unmet, medical need have captured the attention of venture capital investors, who have collectively invested close to $10 billion in research and development of new retinal therapeutics between 2004 and 2023. Notably, the field of exudative diseases has gradually shifted away from trying to outcompete anti-VEGF therapeutics towards lowering the overall treatment burden by reducing injection frequency. Simultaneously, a new era has emerged in the non-exudative field, targeting prevalent conditions like dry AMD and rare indications such as Retinitis pigmentosa. This has led to promising drug candidates in development, culminating in the landmark approval of Luxturna for a rare form of Retinitis pigmentosa. The validation of new mechanisms, such as the complement pathway in dry AMD has paved the way for the approvals of Syvovre (Apellis) and Izervay (Iveric/Astellas), marking the first two therapies for this condition. In this comprehensive review, we share our view on the cumulative lessons from the past two decades in developing retinal therapeutics, covering both positive achievements and challenges. We also contextualize the investments, strategic partnering deals, and acquisitions of biotech companies, pharmaceutical companies venture capital investors in retinal therapeutics, respectively. Finally, we provide an outlook and potentially a forward-looking roadmap on novel retinal therapeutics, highlighting the emergence of potential new intervention strategies, such as cell-based therapies, gene editing, and combination therapies. We conclude that upcoming developments have the potential to further stimulate venture capital investments, which ultimately could facilitate the development and delivery of new therapies to patients in need.
Collapse
Affiliation(s)
| | | | | | | | - Simon J Clark
- Institute for Ophthalmic Research, Department for Ophthalmology, University Medical Center, Eberhard Karls University of Tübingen, Tübingen, Germany; University Eye Clinic, University Hospital Tübingen, Tübingen, Germany; Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| |
Collapse
|
9
|
Mellors J, Carroll M. Direct enhancement of viral neutralising antibody potency by the complement system: a largely forgotten phenomenon. Cell Mol Life Sci 2024; 81:22. [PMID: 38200235 PMCID: PMC10781860 DOI: 10.1007/s00018-023-05074-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/24/2023] [Accepted: 11/29/2023] [Indexed: 01/12/2024]
Abstract
Neutralisation assays are commonly used to assess vaccine-induced and naturally acquired immune responses; identify correlates of protection; and inform important decisions on the screening, development, and use of therapeutic antibodies. Neutralisation assays are useful tools that provide the gold standard for measuring the potency of neutralising antibodies, but they are not without limitations. Common methods such as the heat-inactivation of plasma samples prior to neutralisation assays, or the use of anticoagulants such as EDTA for blood collection, can inactivate the complement system. Even in non-heat-inactivated samples, the levels of complement activity can vary between samples. This can significantly impact the conclusions regarding neutralising antibody potency. Restoration of the complement system in these samples can be achieved using an exogenous source of plasma with preserved complement activity or with purified complement proteins. This can significantly enhance the neutralisation titres for some antibodies depending on characteristics such as antibody isotype and the epitope they bind, enable neutralisation with otherwise non-neutralising antibodies, and demonstrate a better relationship between in vitro and in vivo findings. In this review, we discuss the evidence for complement-mediated enhancement of antibody neutralisation against a range of viruses, explore the potential mechanisms which underpin this enhancement, highlight current gaps in the literature, and provide a brief summary of considerations for adopting this approach in future research applications.
Collapse
Affiliation(s)
- Jack Mellors
- Centre for Human Genetics and the Pandemic Sciences Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Miles Carroll
- Centre for Human Genetics and the Pandemic Sciences Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
10
|
Singh S, Tian W, Severance ZC, Chaudhary SK, Anokhina V, Mondal B, Pergu R, Singh P, Dhawa U, Singha S, Choudhary A. Proximity-inducing modalities: the past, present, and future. Chem Soc Rev 2023; 52:5485-5515. [PMID: 37477631 DOI: 10.1039/d2cs00943a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Living systems use proximity to regulate biochemical processes. Inspired by this phenomenon, bifunctional modalities that induce proximity have been developed to redirect cellular processes. An emerging example of this class is molecules that induce ubiquitin-dependent proteasomal degradation of a protein of interest, and their initial development sparked a flurry of discovery for other bifunctional modalities. Recent advances in this area include modalities that can change protein phosphorylation, glycosylation, and acetylation states, modulate gene expression, and recruit components of the immune system. In this review, we highlight bifunctional modalities that perform functions other than degradation and have great potential to revolutionize disease treatment, while also serving as important tools in basic research to explore new aspects of biology.
Collapse
Affiliation(s)
- Sameek Singh
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Wenzhi Tian
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Zachary C Severance
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Santosh K Chaudhary
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Viktoriya Anokhina
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Basudeb Mondal
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Rajaiah Pergu
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Prashant Singh
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Uttam Dhawa
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Santanu Singha
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Amit Choudhary
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
- Divisions of Renal Medicine and Engineering, Brigham and Women's Hospital, Boston, MA 02115, USA
| |
Collapse
|
11
|
Voisin TB, Couves EC, Tate EW, Bubeck D. Dynamics and Molecular Interactions of GPI-Anchored CD59. Toxins (Basel) 2023; 15:430. [PMID: 37505699 PMCID: PMC10467114 DOI: 10.3390/toxins15070430] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/13/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023] Open
Abstract
CD59 is a GPI-anchored cell surface receptor that serves as a gatekeeper to controlling pore formation. It is the only membrane-bound inhibitor of the complement membrane attack complex (MAC), an immune pore that can damage human cells. While CD59 blocks MAC pores, the receptor is co-opted by bacterial pore-forming proteins to target human cells. Recent structures of CD59 in complexes with binding partners showed dramatic differences in the orientation of its ectodomain relative to the membrane. Here, we show how GPI-anchored CD59 can satisfy this diversity in binding modes. We present a PyLipID analysis of coarse-grain molecular dynamics simulations of a CD59-inhibited MAC to reveal residues of complement proteins (C6:Y285, C6:R407 C6:K412, C7:F224, C8β:F202, C8β:K326) that likely interact with lipids. Using modules of the MDAnalysis package to investigate atomistic simulations of GPI-anchored CD59, we discover properties of CD59 that encode the flexibility necessary to bind both complement proteins and bacterial virulence factors.
Collapse
Affiliation(s)
- Tomas B. Voisin
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - Emma C. Couves
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - Edward W. Tate
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK
| | - Doryen Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
12
|
Yadav GP, Wang H, Ouwendijk J, Cross S, Wang Q, Qin F, Verkade P, Zhu MX, Jiang QX. Chromogranin B (CHGB) is dimorphic and responsible for dominant anion channels delivered to cell surface via regulated secretion. Front Mol Neurosci 2023; 16:1205516. [PMID: 37435575 PMCID: PMC10330821 DOI: 10.3389/fnmol.2023.1205516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 05/26/2023] [Indexed: 07/13/2023] Open
Abstract
Regulated secretion is conserved in all eukaryotes. In vertebrates granin family proteins function in all key steps of regulated secretion. Phase separation and amyloid-based storage of proteins and small molecules in secretory granules require ion homeostasis to maintain their steady states, and thus need ion conductances in granule membranes. But granular ion channels are still elusive. Here we show that granule exocytosis in neuroendocrine cells delivers to cell surface dominant anion channels, to which chromogranin B (CHGB) is critical. Biochemical fractionation shows that native CHGB distributes nearly equally in soluble and membrane-bound forms, and both reconstitute highly selective anion channels in membrane. Confocal imaging resolves granular membrane components including proton pumps and CHGB in puncta on the cell surface after stimulated exocytosis. High pressure freezing immuno-EM reveals a major fraction of CHGB at granule membranes in rat pancreatic β-cells. A cryo-EM structure of bCHGB dimer of a nominal 3.5 Å resolution delineates a central pore with end openings, physically sufficient for membrane-spanning and large single channel conductance. Together our data support that CHGB-containing (CHGB+) channels are characteristic of regulated secretion, and function in granule ion homeostasis near the plasma membrane or possibly in other intracellular processes.
Collapse
Affiliation(s)
- Gaya P. Yadav
- Departments of Microbiology and Cell Science and of Medicinal Chemistry, University of Florida, Gainesville, FL, United States
- Departments of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY, United States
- Laboratory of Molecular Physiology and Biophysics, Hauptman-Woodward Medical Research Institute, Buffalo, NY, United States
| | - Haiyuan Wang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Joke Ouwendijk
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Stephen Cross
- Wolfson Bioimaging facility, University of Bristol, Bristol, United Kingdom
| | - Qiaochu Wang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Feng Qin
- Departments of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY, United States
| | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Michael X. Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Qiu-Xing Jiang
- Departments of Microbiology and Cell Science and of Medicinal Chemistry, University of Florida, Gainesville, FL, United States
- Departments of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY, United States
- Laboratory of Molecular Physiology and Biophysics, Hauptman-Woodward Medical Research Institute, Buffalo, NY, United States
- Cryo-EM Center, Laoshan Laboratory, Qingdao, Shandong, China
| |
Collapse
|
13
|
Sülzen H, Began J, Dhillon A, Kereïche S, Pompach P, Votrubova J, Zahedifard F, Šubrtova A, Šafner M, Hubalek M, Thompson M, Zoltner M, Zoll S. Cryo-EM structures of Trypanosoma brucei gambiense ISG65 with human complement C3 and C3b and their roles in alternative pathway restriction. Nat Commun 2023; 14:2403. [PMID: 37105991 PMCID: PMC10140031 DOI: 10.1038/s41467-023-37988-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
African Trypanosomes have developed elaborate mechanisms to escape the adaptive immune response, but little is known about complement evasion particularly at the early stage of infection. Here we show that ISG65 of the human-infective parasite Trypanosoma brucei gambiense is a receptor for human complement factor C3 and its activation fragments and that it takes over a role in selective inhibition of the alternative pathway C5 convertase and thus abrogation of the terminal pathway. No deposition of C4b, as part of the classical and lectin pathway convertases, was detected on trypanosomes. We present the cryo-electron microscopy (EM) structures of native C3 and C3b in complex with ISG65 which reveal a set of modes of complement interaction. Based on these findings, we propose a model for receptor-ligand interactions as they occur at the plasma membrane of blood-stage trypanosomes and may facilitate innate immune escape of the parasite.
Collapse
Affiliation(s)
- Hagen Sülzen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- Faculty of Science, Charles University, Albertov 6, 12800, Prague 2, Czech Republic
| | - Jakub Began
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- Department of Immunobiology, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Arun Dhillon
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Sami Kereïche
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- First Faculty of Medicine, Charles University, Albertov 4, 12800, Prague, Czech Republic
| | - Petr Pompach
- Institute of Biotechnology of the Czech Academy of Sciences, 25250, Vestec, Czech Republic
| | - Jitka Votrubova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Farnaz Zahedifard
- Department of Parasitology, Faculty of Science, Charles University Prague, Biocev, 25250, Vestec, Czech Republic
| | - Adriana Šubrtova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Marie Šafner
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Martin Hubalek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
| | - Maaike Thompson
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic
- University of Antwerp, Antwerp, Belgium
- Agidens, Industrial Machinery Manufacturing, Zwijndrecht, Antwerp, Belgium
| | - Martin Zoltner
- Department of Parasitology, Faculty of Science, Charles University Prague, Biocev, 25250, Vestec, Czech Republic
| | - Sebastian Zoll
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 16000, Prague, Czech Republic.
| |
Collapse
|
14
|
Ruiz-Molina N, Parsons J, Decker EL, Reski R. Structural modelling of human complement FHR1 and two of its synthetic derivatives provides insight into their in-vivo functions. Comput Struct Biotechnol J 2023; 21:1473-1486. [PMID: 36851916 PMCID: PMC9957715 DOI: 10.1016/j.csbj.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 02/05/2023] Open
Abstract
Human complement is the first line of defence against invading pathogens and is involved in tissue homeostasis. Complement-targeted therapies to treat several diseases caused by a dysregulated complement are highly desirable. Despite huge efforts invested in their development, only very few are currently available, and a deeper understanding of the numerous interactions and complement regulation mechanisms is indispensable. Two important complement regulators are human Factor H (FH) and Factor H-related protein 1 (FHR1). MFHR1 and MFHR13, two promising therapeutic candidates based on these regulators, combine the dimerization and C5-regulatory domains of FHR1 with the central C3-regulatory and cell surface-recognition domains of FH. Here, we used AlphaFold2 to model the structure of these two synthetic regulators. Moreover, we used AlphaFold-Multimer (AFM) to study possible interactions of C3 fragments and membrane attack complex (MAC) components C5, C7 and C9 in complex with FHR1, MFHR1, MFHR13 as well as the best-known MAC regulators vitronectin (Vn), clusterin and CD59, whose experimental structures remain undetermined. AFM successfully predicted the binding interfaces of FHR1 and the synthetic regulators with C3 fragments and suggested binding to C3. The models revealed structural differences in binding to these ligands through different interfaces. Additionally, AFM predictions of Vn, clusterin or CD59 with C7 or C9 agreed with previously published experimental results. Because the role of FHR1 as MAC regulator has been controversial, we analysed possible interactions with C5, C7 and C9. AFM predicted interactions of FHR1 with proteins of the terminal complement complex (TCC) as indicated by experimental observations, and located the interfaces in FHR11-2 and FHR14-5. According to AFM prediction, FHR1 might partially block the C3b binding site in C5, inhibiting C5 activation, and block C5b-7 complex formation and C9 polymerization, with similar mechanisms of action as clusterin and vitronectin. Here, we generate hypotheses and give the basis for the design of rational approaches to understand the molecular mechanism of MAC inhibition, which will facilitate the development of further complement therapeutics.
Collapse
Affiliation(s)
- Natalia Ruiz-Molina
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Eva L Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| |
Collapse
|
15
|
Couves EC, Gardner S, Voisin TB, Bickel JK, Stansfeld PJ, Tate EW, Bubeck D. Structural basis for membrane attack complex inhibition by CD59. Nat Commun 2023; 14:890. [PMID: 36797260 PMCID: PMC9935631 DOI: 10.1038/s41467-023-36441-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/01/2023] [Indexed: 02/18/2023] Open
Abstract
CD59 is an abundant immuno-regulatory receptor that protects human cells from damage during complement activation. Here we show how the receptor binds complement proteins C8 and C9 at the membrane to prevent insertion and polymerization of membrane attack complex (MAC) pores. We present cryo-electron microscopy structures of two inhibited MAC precursors known as C5b8 and C5b9. We discover that in both complexes, CD59 binds the pore-forming β-hairpins of C8 to form an intermolecular β-sheet that prevents membrane perforation. While bound to C8, CD59 deflects the cascading C9 β-hairpins, rerouting their trajectory into the membrane. Preventing insertion of C9 restricts structural transitions of subsequent monomers and indirectly halts MAC polymerization. We combine our structural data with cellular assays and molecular dynamics simulations to explain how the membrane environment impacts the dual roles of CD59 in controlling pore formation of MAC, and as a target of bacterial virulence factors which hijack CD59 to lyse human cells.
Collapse
Affiliation(s)
- Emma C Couves
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Scott Gardner
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Tomas B Voisin
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Jasmine K Bickel
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, United Kingdom
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, United Kingdom
| | - Phillip J Stansfeld
- School of Life Sciences and Department of Chemistry, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Edward W Tate
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, W12 0BZ, United Kingdom
| | - Doryen Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, United Kingdom.
| |
Collapse
|
16
|
The neoepitope of the complement C5b-9 Membrane Attack Complex is formed by proximity of adjacent ancillary regions of C9. Commun Biol 2023; 6:42. [PMID: 36639734 PMCID: PMC9838529 DOI: 10.1038/s42003-023-04431-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 01/05/2023] [Indexed: 01/15/2023] Open
Abstract
The Membrane Attack Complex (MAC) is responsible for forming large β-barrel channels in the membranes of pathogens, such as gram-negative bacteria. Off-target MAC assembly on endogenous tissue is associated with inflammatory diseases and cancer. Accordingly, a human C5b-9 specific antibody, aE11, has been developed that detects a neoepitope exposed in C9 when it is incorporated into the C5b-9 complex, but not present in the plasma native C9. For nearly four decades aE11 has been routinely used to study complement, MAC-related inflammation, and pathophysiology. However, the identity of C9 neoepitope remains unknown. Here, we determined the cryo-EM structure of aE11 in complex with polyC9 at 3.2 Å resolution. The aE11 binding site is formed by two separate surfaces of the oligomeric C9 periphery and is therefore a discontinuous quaternary epitope. These surfaces are contributed by portions of the adjacent TSP1, LDLRA, and MACPF domains of two neighbouring C9 protomers. By substituting key antibody interacting residues to the murine orthologue, we validated the unusual binding modality of aE11. Furthermore, aE11 can recognise a partial epitope in purified monomeric C9 in vitro, albeit weakly. Taken together, our results reveal the structural basis for MAC recognition by aE11.
Collapse
|
17
|
Li H, Xie X, Bai G, Qiang D, Zhang L, Liu H, He Y, Tang Y, Li L. Vitamin D deficiency leads to the abnormal activation of the complement system. Immunol Res 2023; 71:29-38. [PMID: 36178657 PMCID: PMC9845165 DOI: 10.1007/s12026-022-09324-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/19/2022] [Indexed: 01/21/2023]
Abstract
Vitamin D deficiency can damage the human immune system, and the complement system is a key component of the immune system. This study aimed to elucidate the mechanism by which vitamin D affects the immune system by analyzing the changes in the protein expression of the complement system under different vitamin D levels. We selected 40 participants and divided them into three groups according to their serum levels of 25-hydroxyvitamin D (25(OH)VD): group A, 25(OH)VD ≥ 40 ng/mL; group B, 30 ng/mL ≤ 25(OH)VD < 40 ng/mL; and group C, 25(OH)VD < 30 ng/mL. Serum samples were subjected to biochemical analysis, followed by proteomic analysis using high-throughput untargeted proteomic techniques. Vitamin D deficiency increased the levels of fasting blood sugar, fasting serum insulin, and homeostasis model assessment (HOMA) of insulin resistance and decreased the secretion of HOMA of β-cell function, which led to insulin resistance and glucose metabolism disorder. Moreover, vitamin D deficiency resulted in the abnormal expression of 56 differential proteins, among which the expression levels of complement factor B, complement component C9, inducible co-stimulator ligand, and peptidase inhibitor 16 significantly changed with the decrease in vitamin D content. Functional enrichment analysis of these differential proteins showed that they were mainly concentrated in functions and pathways related to insulin secretion and inflammation. In conclusion, vitamin D deficiency not only contributes to insulin resistance and glucose metabolism disorder but also causes abnormal protein expression, resulting in the abnormal activation of the complement system. This study provides a novel theoretical basis for further studies on the relationship between vitamin D and the immune system.
Collapse
Affiliation(s)
- Huan Li
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Xiaomin Xie
- Department of Endocrinology, The First People's Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001, China.
| | - Guirong Bai
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Dan Qiang
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Li Zhang
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Huili Liu
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Yanting He
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Yanpan Tang
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| | - Ling Li
- Department of Endocrinology, The First People’s Hospital of Yinchuan, Ningxia Hui Autonomous Region, No. 2, Liqun West Street, Xingqing District, Yinchuan, 750001 China
| |
Collapse
|
18
|
Zarantonello A, Revel M, Grunenwald A, Roumenina LT. C3-dependent effector functions of complement. Immunol Rev 2023; 313:120-138. [PMID: 36271889 PMCID: PMC10092904 DOI: 10.1111/imr.13147] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
C3 is the central effector molecule of the complement system, mediating its multiple functions through different binding sites and their corresponding receptors. We will introduce the C3 forms (native C3, C3 [H2 O], and intracellular C3), the C3 fragments C3a, C3b, iC3b, and C3dg/C3d, and the C3 expression sites. To highlight the important role that C3 plays in human biological processes, we will give an overview of the diseases linked to C3 deficiency and to uncontrolled C3 activation. Next, we will present a structural description of C3 activation and of the C3 fragments generated by complement regulation. We will proceed by describing the C3a interaction with the anaphylatoxin receptor, followed by the interactions of opsonins (C3b, iC3b, and C3dg/C3d) with complement receptors, divided into two groups: receptors bearing complement regulatory functions and the effector receptors without complement regulatory activity. We outline the molecular architecture of the receptors, their binding sites on the C3 activation fragments, the cells expressing them, the diversity of their functions, and recent advances. With this review, we aim to give an up-to-date analysis of the processes triggered by C3 activation fragments on different cell types in health and disease contexts.
Collapse
Affiliation(s)
- Alessandra Zarantonello
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Margot Revel
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Anne Grunenwald
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Lubka T Roumenina
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| |
Collapse
|
19
|
The Emerging Roles of Extracellular Chaperones in Complement Regulation. Cells 2022; 11:cells11233907. [PMID: 36497163 PMCID: PMC9738919 DOI: 10.3390/cells11233907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/09/2022] Open
Abstract
The immune system is essential to protect organisms from internal and external threats. The rapidly acting, non-specific innate immune system includes complement, which initiates an inflammatory cascade and can form pores in the membranes of target cells to induce cell lysis. Regulation of protein homeostasis (proteostasis) is essential for normal cellular and organismal function, and has been implicated in processes controlling immunity and infection. Chaperones are key players in maintaining proteostasis in both the intra- and extracellular environments. Whilst intracellular proteostasis is well-characterised, the role of constitutively secreted extracellular chaperones (ECs) is less well understood. ECs may interact with invading pathogens, and elements of the subsequent immune response, including the complement pathway. Both ECs and complement can influence the progression of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis, as well as other diseases including kidney diseases and diabetes. This review will examine known and recently discovered ECs, and their roles in immunity, with a specific focus on the complement pathway.
Collapse
|
20
|
Yu X, Ni T, Munson G, Zhang P, Gilbert RJC. Cryo-EM structures of perforin-2 in isolation and assembled on a membrane suggest a mechanism for pore formation. EMBO J 2022; 41:e111857. [PMID: 36245269 PMCID: PMC9713709 DOI: 10.15252/embj.2022111857] [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: 06/13/2022] [Revised: 07/29/2022] [Accepted: 09/09/2022] [Indexed: 01/15/2023] Open
Abstract
Perforin-2 (PFN2, MPEG1) is a key pore-forming protein in mammalian innate immunity restricting intracellular bacteria proliferation. It forms a membrane-bound pre-pore complex that converts to a pore-forming structure upon acidification; but its mechanism of conformational transition has been debated. Here we used cryo-electron microscopy, tomography and subtomogram averaging to determine structures of PFN2 in pre-pore and pore conformations in isolation and bound to liposomes. In isolation and upon acidification, the pre-assembled complete pre-pore rings convert to pores in both flat ring and twisted conformations. On membranes, in situ assembled PFN2 pre-pores display various degrees of completeness; whereas PFN2 pores are mainly incomplete arc structures that follow the same subunit packing arrangements as found in isolation. Both assemblies on membranes use their P2 β-hairpin for binding to the lipid membrane surface. Overall, these structural snapshots suggest a molecular mechanism for PFN2 pre-pore to pore transition on a targeted membrane, potentially using the twisted pore as an intermediate or alternative state to the flat conformation, with the capacity to cause bilayer distortion during membrane insertion.
Collapse
Affiliation(s)
- Xiulian Yu
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Calleva Research Centre for Evolution and Human Sciences, Magdalen CollegeUniversity of OxfordOxfordUK
| | - Tao Ni
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Present address:
School of Biomedical Sciences, LKS Faculty of MedicineThe University of Hong KongPokfulamHong Kong SARChina
| | - George Munson
- Department of Microbiology and ImmunologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Diamond Light SourceHarwell Science and Innovation CampusDidcotUK
- Chinese Academy of Medical Sciences Oxford InstituteUniversity of OxfordOxfordUK
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Calleva Research Centre for Evolution and Human Sciences, Magdalen CollegeUniversity of OxfordOxfordUK
| |
Collapse
|
21
|
Crine SL, Acharya KR. Molecular basis of C-mannosylation - a structural perspective. FEBS J 2022; 289:7670-7687. [PMID: 34741587 DOI: 10.1111/febs.16265] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/22/2021] [Accepted: 11/04/2021] [Indexed: 01/14/2023]
Abstract
The structural and functional diversity of proteins can be enhanced by numerous post-translational modifications. C-mannosylation is a rare form of glycosylation consisting of a single alpha or beta D-mannopyranose forming a carbon-carbon bond with the pyrrole ring of a tryptophan residue. Despite first being discovered in 1994, C-mannosylation is still poorly understood and 3D structures are available for only a fraction of the total predicted C-mannosylated proteins. Here, we present the first comprehensive review of C-mannosylated protein structures by analysing the data for all 10 proteins with C-mannosylation/s deposited in the Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB). We analysed in detail the WXXW/WXXWXXW consensus motif and the highly conserved pair of arginine residues in thrombospondin type 1 repeat C-mannosylation sites or homologous arginine residues in other domains. Furthermore, we identified a conserved PXP sequence C-terminal of the C-mannosylation site. The PXP motif forms a tight turn region in the polypeptide chain and its universal conservation in C-mannosylated protein is worthy of further experimental study. The stabilization of C-mannopyranosyl groups was demonstrated through hydrogen bonding with arginine and other charged or polar amino acids. Where possible, the structural findings were linked to other functional studies demonstrating the role of C-mannosylation in protein stability, secretion or function. With the current technological advances in structural biology, we hope to see more progress in the study of C-mannosylation that may correspond to discoveries of novel C-mannosylation pathways and functions with implications for human health and biotechnology.
Collapse
Affiliation(s)
- Samuel L Crine
- Department of Biology and Biochemistry, University of Bath, UK
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, UK
| |
Collapse
|
22
|
Jia X, Knyazeva A, Zhang Y, Castro-Gonzalez S, Nakamura S, Carlson LA, Yoshimori T, Corkery DP, Wu YW. V. cholerae MakA is a cholesterol-binding pore-forming toxin that induces non-canonical autophagy. J Cell Biol 2022; 221:213518. [PMID: 36194176 PMCID: PMC9536202 DOI: 10.1083/jcb.202206040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/16/2022] [Accepted: 09/16/2022] [Indexed: 01/18/2023] Open
Abstract
Pore-forming toxins (PFTs) are important virulence factors produced by many pathogenic bacteria. Here, we show that the Vibrio cholerae toxin MakA is a novel cholesterol-binding PFT that induces non-canonical autophagy in a pH-dependent manner. MakA specifically binds to cholesterol on the membrane at pH < 7. Cholesterol-binding leads to oligomerization of MakA on the membrane and pore formation at pH 5.5. Unlike other cholesterol-dependent cytolysins (CDCs) which bind cholesterol through a conserved cholesterol-binding motif (Thr-Leu pair), MakA contains an Ile-Ile pair that is essential for MakA-cholesterol interaction. Following internalization, endosomal acidification triggers MakA pore-assembly followed by ESCRT-mediated membrane repair and V-ATPase-dependent unconventional LC3 lipidation on the damaged endolysosomal membranes. These findings characterize a new cholesterol-binding toxin that forms pores in a pH-dependent manner and reveals the molecular mechanism of host autophagy manipulation.
Collapse
Affiliation(s)
- Xiaotong Jia
- Department of Chemistry, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Anastasia Knyazeva
- Department of Chemistry, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Yu Zhang
- Department of Chemistry, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Sergio Castro-Gonzalez
- Department of Chemistry, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Shuhei Nakamura
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Lars-Anders Carlson
- Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden,Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden,Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden,Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Dale P. Corkery
- Department of Chemistry, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden,Dale P. Corkery:
| | - Yao-Wen Wu
- Department of Chemistry, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden,Correspondence to Yao-Wen Wu:
| |
Collapse
|
23
|
Raballah E, Wilding K, Anyona SB, Munde EO, Hurwitz I, Onyango CO, Ayieko C, Lambert CG, Schneider KA, Seidenberg PD, Ouma C, McMahon BH, Cheng Q, Perkins DJ. Nonsynonymous amino acid changes in the α-chain of complement component 5 influence longitudinal susceptibility to Plasmodium falciparum infections and severe malarial anemia in kenyan children. Front Genet 2022; 13:977810. [PMID: 36186473 PMCID: PMC9515573 DOI: 10.3389/fgene.2022.977810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Severe malarial anemia (SMA; Hb < 5.0 g/dl) is a leading cause of childhood morbidity and mortality in holoendemic Plasmodium falciparum transmission regions such as western Kenya. Methods: We investigated the relationship between two novel complement component 5 (C5) missense mutations [rs17216529:C>T, p(Val145Ile) and rs17610:C>T, p(Ser1310Asn)] and longitudinal outcomes of malaria in a cohort of Kenyan children (under 60 mos, n = 1,546). Molecular modeling was used to investigate the impact of the amino acid transitions on the C5 protein structure. Results: Prediction of the wild-type and mutant C5 protein structures did not reveal major changes to the overall structure. However, based on the position of the variants, subtle differences could impact on the stability of C5b. The influence of the C5 genotypes/haplotypes on the number of malaria and SMA episodes over 36 months was determined by Poisson regression modeling. Genotypic analyses revealed that inheritance of the homozygous mutant (TT) for rs17216529:C>T enhanced the risk for both malaria (incidence rate ratio, IRR = 1.144, 95%CI: 1.059-1.236, p = 0.001) and SMA (IRR = 1.627, 95%CI: 1.201-2.204, p = 0.002). In the haplotypic model, carriers of TC had increased risk of malaria (IRR = 1.068, 95%CI: 1.017-1.122, p = 0.009), while carriers of both wild-type alleles (CC) were protected against SMA (IRR = 0.679, 95%CI: 0.542-0.850, p = 0.001). Conclusion: Collectively, these findings show that the selected C5 missense mutations influence the longitudinal risk of malaria and SMA in immune-naïve children exposed to holoendemic P. falciparum transmission through a mechanism that remains to be defined.
Collapse
Affiliation(s)
- Evans Raballah
- University of New Mexico-Kenya Global Health Programs, Kisumu, Kenya
- Department of Medical Laboratory Sciences, School of Public Health Biomedical Sciences and Technology, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - Kristen Wilding
- Theoretical Biology and Biophysics Group, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Samuel B. Anyona
- University of New Mexico-Kenya Global Health Programs, Kisumu, Kenya
- Department of Medical Biochemistry, School of Medicine, Maseno University, Maseno, Kenya
| | - Elly O. Munde
- University of New Mexico-Kenya Global Health Programs, Kisumu, Kenya
- Department of Clinical Medicine, School of Health Sciences, Kirinyaga University, Kerugoya, Kenya
| | - Ivy Hurwitz
- University of New Mexico, Center for Global Health, Department of Internal Medicine, Albuquerque, NM, United States
| | - Clinton O. Onyango
- University of New Mexico-Kenya Global Health Programs, Kisumu, Kenya
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya
| | - Cyrus Ayieko
- Department of Zoology, Maseno University, Maseno, Kenya
| | - Christophe G. Lambert
- University of New Mexico, Center for Global Health, Department of Internal Medicine, Albuquerque, NM, United States
| | - Kristan A. Schneider
- Department of Applied Computer and Biosciences, University of Applied Sciences Mittweida, Mittweida, Germany
| | - Philip D. Seidenberg
- University of New Mexico, Department of Emergency Medicine, Albuquerque, NM, United States
| | - Collins Ouma
- University of New Mexico-Kenya Global Health Programs, Kisumu, Kenya
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya
| | - Benjamin H. McMahon
- Theoretical Biology and Biophysics Group, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Qiuying Cheng
- University of New Mexico, Center for Global Health, Department of Internal Medicine, Albuquerque, NM, United States
| | - Douglas J. Perkins
- University of New Mexico-Kenya Global Health Programs, Kisumu, Kenya
- University of New Mexico, Center for Global Health, Department of Internal Medicine, Albuquerque, NM, United States
| |
Collapse
|
24
|
Lekova E, Zelek WM, Gower D, Spitzfaden C, Osuch IH, John-Morris E, Stach L, Gormley D, Sanderson A, Bridges A, Wear ER, Petit-Frere S, Burden MN, Priest R, Wattam T, Kitchen SJ, Feeney M, Davis S, Morgan BP, Nichols EM. Discovery of functionally distinct anti-C7 monoclonal antibodies and stratification of anti-nicotinic AChR positive Myasthenia Gravis patients. Front Immunol 2022; 13:968206. [PMID: 36148231 PMCID: PMC9486540 DOI: 10.3389/fimmu.2022.968206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Myasthenia Gravis (MG) is mediated by autoantibodies against acetylcholine receptors that cause loss of the receptors in the neuromuscular junction. Eculizumab, a C5-inhibitor, is the only approved treatment for MG that mechanistically addresses complement-mediated loss of nicotinic acetylcholine receptors. It is an expensive drug and was approved despite missing the primary efficacy endpoint in the Phase 3 REGAIN study. There are two observations to highlight. Firstly, further C5 inhibitors are in clinical development, but other terminal pathway proteins, such as C7, have been relatively understudied as therapeutic targets, despite the potential for lower and less frequent dosing. Secondly, given the known heterogenous mechanisms of action of autoantibodies in MG, effective patient stratification in the REGAIN trial may have provided more favorable efficacy readouts. We investigated C7 as a target and assessed the in vitro function, binding epitopes and mechanism of action of three mAbs against C7. We found the mAbs were human, cynomolgus monkey and/or rat cross-reactive and each had a distinct, novel mechanism of C7 inhibition. TPP1820 was effective in preventing experimental MG in rats in both prophylactic and therapeutic dosing regimens. To enable identification of MG patients that are likely to respond to C7 inhibition, we developed a patient stratification assay and showed in a small cohort of MG patients (n=19) that 63% had significant complement activation and C7-dependent loss of AChRs in this in vitro set up. This study provides validation of C7 as a target for treatment of MG and provides a means of identifying patients likely to respond to anti-C7 therapy based on complement-activating properties of patient autoantibodies.
Collapse
Affiliation(s)
- Eleonora Lekova
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Wioleta M. Zelek
- Division of Infection and Immunity and Dementia Research Institute, Systems Immunity Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
| | - David Gower
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Claus Spitzfaden
- Medicines, Science and Technology, Protein Cellular and Structural Sciences (PCSS) Structural and Biophysical Sciences, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Isabelle H. Osuch
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Elen John-Morris
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Lasse Stach
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Darren Gormley
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Andrew Sanderson
- Medicines, Science and Technology, Protein Cellular and Structural Sciences (PCSS) Protein and Cellular Sciences, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Angela Bridges
- Medicines, Science and Technology, Protein Cellular and Structural Sciences (PCSS) Protein and Cellular Sciences, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Elizabeth R. Wear
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Sebastien Petit-Frere
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Michael N. Burden
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Richard Priest
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Trevor Wattam
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Semra J. Kitchen
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Maria Feeney
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Susannah Davis
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - B. Paul Morgan
- Division of Infection and Immunity and Dementia Research Institute, Systems Immunity Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
| | - Eva-Maria Nichols
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
- *Correspondence: Eva-Maria Nichols,
| |
Collapse
|
25
|
Macleod OJS, Cook AD, Webb H, Crow M, Burns R, Redpath M, Seisenberger S, Trevor CE, Peacock L, Schwede A, Kimblin N, Francisco AF, Pepperl J, Rust S, Voorheis P, Gibson W, Taylor MC, Higgins MK, Carrington M. Invariant surface glycoprotein 65 of Trypanosoma brucei is a complement C3 receptor. Nat Commun 2022; 13:5085. [PMID: 36038546 PMCID: PMC9424271 DOI: 10.1038/s41467-022-32728-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
African trypanosomes are extracellular pathogens of mammals and are exposed to the adaptive and innate immune systems. Trypanosomes evade the adaptive immune response through antigenic variation, but little is known about how they interact with components of the innate immune response, including complement. Here we demonstrate that an invariant surface glycoprotein, ISG65, is a receptor for complement component 3 (C3). We show how ISG65 binds to the thioester domain of C3b. We also show that C3 contributes to control of trypanosomes during early infection in a mouse model and provide evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance. Deposition of C3b on pathogen surfaces, such as trypanosomes, is a central point in activation of the complement system. In ISG65, trypanosomes have evolved a C3 receptor which diminishes the downstream effects of C3 deposition on the control of infection. Trypanosomes evade the immune response through antigenic variation of a surface coat containing variant surface glycoproteins (VSG). They also express invariant surface glycoproteins (ISGs), which are less well understood. Here, Macleod et al. show that ISG65 of T. brucei is a receptor for complement component 3. They provide the crystal structure of T. brucei ISG65 in complex with complement C3d and show evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance in vivo.
Collapse
Affiliation(s)
- Olivia J S Macleod
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Alexander D Cook
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Helena Webb
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Mandy Crow
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Roisin Burns
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Maria Redpath
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Stefanie Seisenberger
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Camilla E Trevor
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Lori Peacock
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Angela Schwede
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Nicola Kimblin
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Amanda F Francisco
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Julia Pepperl
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Steve Rust
- Antibody Discovery and Protein Engineering, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Paul Voorheis
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Wendy Gibson
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Martin C Taylor
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK. .,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.
| |
Collapse
|
26
|
Doorduijn DJ, Lukassen MV, van 't Wout MFL, Franc V, Ruyken M, Bardoel BW, Heck AJR, Rooijakkers SHM. Soluble MAC is primarily released from MAC-resistant bacteria that potently convert complement component C5. eLife 2022; 11:77503. [PMID: 35947526 PMCID: PMC9402229 DOI: 10.7554/elife.77503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 08/01/2022] [Indexed: 11/21/2022] Open
Abstract
The membrane attack complex (MAC or C5b-9) is an important effector of the immune system to kill invading microbes. MAC formation is initiated when complement enzymes on the bacterial surface convert complement component C5 into C5b. Although the MAC is a membrane-inserted complex, soluble forms of MAC (sMAC), or terminal complement complex (TCC), are often detected in sera of patients suffering from infections. Consequently, sMAC has been proposed as a biomarker, but it remains unclear when and how it is formed during infections. Here, we studied mechanisms of MAC formation on different Gram-negative and Gram-positive bacteria and found that sMAC is primarily formed in human serum by bacteria resistant to MAC-dependent killing. Surprisingly, C5 was converted into C5b more potently by MAC-resistant compared to MAC-sensitive Escherichia coli strains. In addition, we found that MAC precursors are released from the surface of MAC-resistant bacteria during MAC assembly. Although release of MAC precursors from bacteria induced lysis of bystander human erythrocytes, serum regulators vitronectin (Vn) and clusterin (Clu) can prevent this. Combining size exclusion chromatography with mass spectrometry profiling, we show that sMAC released from bacteria in serum is a heterogeneous mixture of complexes composed of C5b-8, up to three copies of C9 and multiple copies of Vn and Clu. Altogether, our data provide molecular insight into how sMAC is generated during bacterial infections. This fundamental knowledge could form the basis for exploring the use of sMAC as biomarker.
Collapse
Affiliation(s)
- Dennis J Doorduijn
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marie V Lukassen
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, Utrecht, Netherlands
| | - Marije F L van 't Wout
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Vojtech Franc
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, Utrecht, Netherlands
| | - Maartje Ruyken
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Bart W Bardoel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, Utrecht, Netherlands
| | - Suzan H M Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| |
Collapse
|
27
|
Couves EC, Bubeck D. Capturing pore-forming intermediates of MACPF and binary toxin assemblies by cryoEM. Curr Opin Struct Biol 2022; 75:102401. [PMID: 35700576 DOI: 10.1016/j.sbi.2022.102401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/28/2022] [Accepted: 05/09/2022] [Indexed: 11/15/2022]
Abstract
Deployed by both pathogenic bacteria and host immune systems, pore-forming proteins rupture target membranes and can serve as conduits for effector proteins. Understanding how these proteins work relies on capturing assembly intermediates. Advances in cryoEM allowing in silico purification of heterogeneous assemblies has led to new insights into two main classes of pore-forming proteins: membrane attack complex perforin (MACPF) proteins and binary toxins. The structure of an immune activation complex, sMAC, shows how pores form by sequential templating and insertion of β-hairpins. CryoEM structures of bacterial binary toxins present a series of transitions along the pore formation pathway and reveal a general mechanism of effector protein translocation. Future developments in time-resolved cryoEM could capture and place short-lived states along the trajectory of pore-formation.
Collapse
Affiliation(s)
- Emma C Couves
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London, SW7 2AZ, United Kingdom. https://twitter.com/@EmmaCouves
| | - Doryen Bubeck
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London, SW7 2AZ, United Kingdom.
| |
Collapse
|
28
|
Ivanova ME, Lukoyanova N, Malhotra S, Topf M, Trapani JA, Voskoboinik I, Saibil HR. The pore conformation of lymphocyte perforin. SCIENCE ADVANCES 2022; 8:eabk3147. [PMID: 35148176 PMCID: PMC8836823 DOI: 10.1126/sciadv.abk3147] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/17/2021] [Indexed: 05/05/2023]
Abstract
Perforin is a pore-forming protein that facilitates rapid killing of pathogen-infected or cancerous cells by the immune system. Perforin is released from cytotoxic lymphocytes, together with proapoptotic granzymes, to bind to a target cell membrane where it oligomerizes and forms pores. The pores allow granzyme entry, which rapidly triggers the apoptotic death of the target cell. Here, we present a 4-Å resolution cryo-electron microscopy structure of the perforin pore, revealing previously unidentified inter- and intramolecular interactions stabilizing the assembly. During pore formation, the helix-turn-helix motif moves away from the bend in the central β sheet to form an intermolecular contact. Cryo-electron tomography shows that prepores form on the membrane surface with minimal conformational changes. Our findings suggest the sequence of conformational changes underlying oligomerization and membrane insertion, and explain how several pathogenic mutations affect function.
Collapse
Affiliation(s)
- Marina E. Ivanova
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet St, London WC1E 7HX, UK
- Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Natalya Lukoyanova
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet St, London WC1E 7HX, UK
| | - Sony Malhotra
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet St, London WC1E 7HX, UK
- Scientific Computing Department, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Fermi Ave, Harwell, Didcot OX11 0QX, UK
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet St, London WC1E 7HX, UK
- Centre for Structural Systems Biology, Leibniz-Institut für Experimentelle Virologie and Universitätsklinikum Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Joseph A. Trapani
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Ilia Voskoboinik
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Helen R. Saibil
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet St, London WC1E 7HX, UK
| |
Collapse
|
29
|
Benton JT, Bayly-Jones C. Challenges and approaches to studying pore-forming proteins. Biochem Soc Trans 2021; 49:2749-2765. [PMID: 34747994 PMCID: PMC8892993 DOI: 10.1042/bst20210706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/19/2021] [Accepted: 10/06/2021] [Indexed: 02/07/2023]
Abstract
Pore-forming proteins (PFPs) are a broad class of molecules that comprise various families, structural folds, and assembly pathways. In nature, PFPs are most often deployed by their host organisms to defend against other organisms. In humans, this is apparent in the immune system, where several immune effectors possess pore-forming activity. Furthermore, applications of PFPs are found in next-generation low-cost DNA sequencing, agricultural crop protection, pest control, and biosensing. The advent of cryoEM has propelled the field forward. Nevertheless, significant challenges and knowledge-gaps remain. Overcoming these challenges is particularly important for the development of custom, purpose-engineered PFPs with novel or desired properties. Emerging single-molecule techniques and methods are helping to address these unanswered questions. Here we review the current challenges, problems, and approaches to studying PFPs.
Collapse
Affiliation(s)
- Joshua T. Benton
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Charles Bayly-Jones
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
30
|
Doorduijn DJ, Heesterbeek DAC, Ruyken M, de Haas CJC, Stapels DAC, Aerts PC, Rooijakkers SHM, Bardoel BW. Polymerization of C9 enhances bacterial cell envelope damage and killing by membrane attack complex pores. PLoS Pathog 2021; 17:e1010051. [PMID: 34752492 PMCID: PMC8604303 DOI: 10.1371/journal.ppat.1010051] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 11/19/2021] [Accepted: 10/20/2021] [Indexed: 11/21/2022] Open
Abstract
Complement proteins can form membrane attack complex (MAC) pores that directly kill Gram-negative bacteria. MAC pores assemble by stepwise binding of C5b, C6, C7, C8 and finally C9, which can polymerize into a transmembrane ring of up to 18 C9 monomers. It is still unclear if the assembly of a polymeric-C9 ring is necessary to sufficiently damage the bacterial cell envelope to kill bacteria. In this paper, polymerization of C9 was prevented without affecting binding of C9 to C5b-8, by locking the first transmembrane helix domain of C9. Using this system, we show that polymerization of C9 strongly enhanced damage to both the bacterial outer and inner membrane, resulting in more rapid killing of several Escherichia coli and Klebsiella strains in serum. By comparing binding of wildtype and ‘locked’ C9 by flow cytometry, we also show that polymerization of C9 is impaired when the amount of available C9 per C5b-8 is limited. This suggests that an excess of C9 is required to efficiently form polymeric-C9. Finally, we show that polymerization of C9 was impaired on complement-resistant E. coli strains that survive killing by MAC pores. This suggests that these bacteria can specifically block polymerization of C9. All tested complement-resistant E. coli expressed LPS O-antigen (O-Ag), compared to only one out of four complement-sensitive E. coli. By restoring O-Ag expression in an O-Ag negative strain, we show that the O-Ag impairs polymerization of C9 and results in complement-resistance. Altogether, these insights are important to understand how MAC pores kill bacteria and how bacterial pathogens can resist MAC-dependent killing. In this paper, we focus on how complement proteins, an essential part of the immune system, kill Gram-negative bacteria via so-called membrane attack complex (MAC) pores. The MAC is a large pore that consists of five different proteins. The final component, C9, assembles a ring of up to 18 C9 molecules that damages the bacterial cell envelope. Here, we aimed to better understand if this polymeric-C9 ring is necessary to kill bacteria and if bacteria can interfere in its assembly. We uncover that polymerization of C9 increased the damage to the entire bacterial cell envelope, which resulted in more rapid killing of several Gram-negative species. We also show that some clinical Escherichia coli strains can block polymerization of C9 and survive MAC-dependent killing by modifying sugars in the bacterial cell envelope, namely the O-antigen of lipopolysaccharide. These insights help us to better understand how the immune system kills bacteria and how pathogenic bacteria can survive killing.
Collapse
Affiliation(s)
- Dennis J. Doorduijn
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Dani A. C. Heesterbeek
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maartje Ruyken
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Carla J. C. de Haas
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Daphne A. C. Stapels
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Piet C. Aerts
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Suzan H. M. Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bart W. Bardoel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
| |
Collapse
|
31
|
Structural basis of soluble membrane attack complex packaging for clearance. Nat Commun 2021; 12:6086. [PMID: 34667172 PMCID: PMC8526713 DOI: 10.1038/s41467-021-26366-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 10/01/2021] [Indexed: 12/15/2022] Open
Abstract
Unregulated complement activation causes inflammatory and immunological pathologies with consequences for human disease. To prevent bystander damage during an immune response, extracellular chaperones (clusterin and vitronectin) capture and clear soluble precursors to the membrane attack complex (sMAC). However, how these chaperones block further polymerization of MAC and prevent the complex from binding target membranes remains unclear. Here, we address that question by combining cryo electron microscopy (cryoEM) and cross-linking mass spectrometry (XL-MS) to solve the structure of sMAC. Together our data reveal how clusterin recognizes and inhibits polymerizing complement proteins by binding a negatively charged surface of sMAC. Furthermore, we show that the pore-forming C9 protein is trapped in an intermediate conformation whereby only one of its two transmembrane β-hairpins has unfurled. This structure provides molecular details for immune pore formation and helps explain a complement control mechanism that has potential implications for how cell clearance pathways mediate immune homeostasis. To prevent unregulated complement activation, extracellular chaperones capture soluble precursors to the membrane attack complex (sMAC). Here, structural analysis of sMAC reveals how clusterin recognizes heterogeneous sMAC complexes and inhibits polymerization of complement protein C9.
Collapse
|
32
|
Zelek WM. Measuring Total Classical Pathway and Activities of Individual Components of the Mouse Complement Pathway. Bio Protoc 2021; 11:e4175. [PMID: 34722822 DOI: 10.21769/bioprotoc.4175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 01/13/2023] Open
Abstract
The complement system is a central component of innate immunity, responsible for recognition and killing of bacteria by tagging invaders through opsonisation, thereby promoting phagocytosis, and by direct lysis. Complement activity is routinely measured using functional assays that utilise erythrocytes as targets. The classical pathway haemolytic assay (CH50) with antibody sensitised sheep erythrocytes as target is used worldwide in clinical and research laboratories to measure complement activity in human and rodent sera. While there are no particular limitations in the human assay, measuring complement in mouse serum is more difficult and usually requires large amounts of serum, which is challenging to collect in experiments. In particular, it is challenging to measure the activities of individual mouse complement proteins. To overcome this hurdle, we have developed protocols that employ human sera depleted of single complement proteins as the source of the other complement proteins and test mouse serum to restore the relevant component. This simple haemolytic assay is a useful tool for confirming natural or engineered complement deficiencies and complement dysregulation in mouse models.
Collapse
Affiliation(s)
- Wioleta M Zelek
- Division of Infection and Immunity and Dementia Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
| |
Collapse
|
33
|
Sahu SK, Kulkarni DH, Ozanturk AN, Ma L, Kulkarni HS. Emerging roles of the complement system in host-pathogen interactions. Trends Microbiol 2021; 30:390-402. [PMID: 34600784 DOI: 10.1016/j.tim.2021.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022]
Abstract
The complement system has historically been entertained as a fluid-phase, hepatically derived system which protects the intravascular space from encapsulated bacteria. However, there has been an increasing appreciation for its role in protection against non-encapsulated pathogens. Specifically, we have an improved understanding of how pathogens are recognized by specific complement proteins, as well as how they trigger and evade them. Additionally, we have an improved understanding of locally derived complement proteins, many of which promote host defense. Moreover, intracellular complement proteins have been identified that facilitate local protection and barrier function despite pathogen invasion. Our review aims to summarize these advances in the field as well as provide an insight into the pathophysiological changes occurring when the system is dysregulated in infection.
Collapse
Affiliation(s)
- Sanjaya K Sahu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Devesha H Kulkarni
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Ayse N Ozanturk
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Lina Ma
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Hrishikesh S Kulkarni
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA; Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
34
|
Beton JG, Moorehead R, Helfmann L, Gray R, Hoogenboom BW, Joseph AP, Topf M, Pyne ALB. TopoStats - A program for automated tracing of biomolecules from AFM images. Methods 2021; 193:68-79. [PMID: 33548405 PMCID: PMC8340030 DOI: 10.1016/j.ymeth.2021.01.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/07/2021] [Accepted: 01/26/2021] [Indexed: 11/20/2022] Open
Abstract
We present TopoStats, a Python toolkit for automated editing and analysis of Atomic Force Microscopy images. The program automates identification and tracing of individual molecules in circular and linear conformations without user input. TopoStats was able to identify and trace a range of molecules within AFM images, finding, on average, ~90% of all individual molecules and molecular assemblies within a wide field of view, and without the need for prior processing. DNA minicircles of varying size, DNA origami rings and pore forming proteins were identified and accurately traced with contour lengths of traces typically within 10 nm of the predicted contour length. TopoStats was also able to reliably identify and trace linear and enclosed circular molecules within a mixed population. The program is freely available via GitHub (https://github.com/afm-spm/TopoStats) and is intended to be modified and adapted for use if required.
Collapse
Affiliation(s)
- Joseph G Beton
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK; Centre for Structural Systems Biology, Heinrich-Pette-Institut, Leibniz-Institut für Experimentelle Virologie and Universitätsklinikum Hamburg Eppendorf, Hamburg, Germany
| | - Robert Moorehead
- The Henry Royce Institute and Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Sheffield S1 3JD, United Kingdom; Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK
| | - Luzie Helfmann
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK; London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Robert Gray
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK; London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Agnel Praveen Joseph
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK; Centre for Structural Systems Biology, Heinrich-Pette-Institut, Leibniz-Institut für Experimentelle Virologie and Universitätsklinikum Hamburg Eppendorf, Hamburg, Germany
| | - Alice L B Pyne
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK; London Centre for Nanotechnology, University College London, London WC1H 0AH, UK.
| |
Collapse
|
35
|
Kulma M, Anderluh G. Beyond pore formation: reorganization of the plasma membrane induced by pore-forming proteins. Cell Mol Life Sci 2021; 78:6229-6249. [PMID: 34387717 PMCID: PMC11073440 DOI: 10.1007/s00018-021-03914-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/09/2021] [Accepted: 08/03/2021] [Indexed: 12/23/2022]
Abstract
Pore-forming proteins (PFPs) are a heterogeneous group of proteins that are expressed and secreted by a wide range of organisms. PFPs are produced as soluble monomers that bind to a receptor molecule in the host cell membrane. They then assemble into oligomers that are incorporated into the lipid membrane to form transmembrane pores. Such pore formation alters the permeability of the plasma membrane and is one of the most common mechanisms used by PFPs to destroy target cells. Interestingly, PFPs can also indirectly manipulate diverse cellular functions. In recent years, increasing evidence indicates that the interaction of PFPs with lipid membranes is not only limited to pore-induced membrane permeabilization but is also strongly associated with extensive plasma membrane reorganization. This includes lateral rearrangement and deformation of the lipid membrane, which can lead to the disruption of target cell function and finally death. Conversely, these modifications also constitute an essential component of the membrane repair system that protects cells from the lethal consequences of pore formation. Here, we provide an overview of the current knowledge on the changes in lipid membrane organization caused by PFPs from different organisms.
Collapse
Affiliation(s)
- Magdalena Kulma
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia
| |
Collapse
|
36
|
Frazer-Abel A, Kirschfink M, Prohászka Z. Expanding Horizons in Complement Analysis and Quality Control. Front Immunol 2021; 12:697313. [PMID: 34434189 PMCID: PMC8381195 DOI: 10.3389/fimmu.2021.697313] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/19/2021] [Indexed: 01/09/2023] Open
Abstract
Complement not only plays a key role in host microbial defense but also modulates the adaptive immune response through modification of T- and B-cell reactivity. Moreover, a normally functioning complement system participates in hematopoiesis, reproduction, lipid metabolism, and tissue regeneration. Because of its powerful inflammatory potential, multiple regulatory proteins are needed to prevent potential tissue damage. In clinical practice, dysregulation and overactivation of the complement system are major causes of a variety of inflammatory and autoimmune diseases ranging from nephropathies, age-related macular degeneration (AMD), and systemic lupus erythematosus (SLE) to graft rejection, sepsis, and multi-organ failure. The clinical importance is reflected by the recent development of multiple drugs targeting complement with a broad spectrum of indications. The recognition of the role of complement in diverse diseases and the advent of complement therapeutics has increased the number of laboratories and suppliers entering the field. This has highlighted the need for reliable complement testing. The relatively rapid expansion in complement testing has presented challenges for a previously niche field. This is exemplified by the issue of cross-reactivity of complement-directed antibodies and by the challenges of the poor stability of many of the complement analytes. The complex nature of complement testing and increasing clinical demand has been met in the last decade by efforts to improve the standardization among laboratories. Initiated by the IUIS/ICS Committee for the Standardization and Quality Assessment in Complement Measurements 14 rounds of external quality assessment since 2010 resulted in improvements in the consistency of testing across participating institutions, while extending the global reach of the efforts to more than 200 laboratories in 30 countries. Worldwide trends of assay availability, usage, and analytical performance are summarized based on the past years’ experiences. Progress in complement analysis has been facilitated by the quality assessment and standardization efforts that now allow complement testing to provide a comprehensive insight into deficiencies and the activation state of the system. This in turn enables clinicians to better define disease severity, evolution, and response to therapy.
Collapse
Affiliation(s)
| | | | - Zoltán Prohászka
- Department of Medicine and Hematology, Research Laboratory Semmelweis University, Budapest, Hungary
| |
Collapse
|
37
|
Mondal AK, Chattopadhyay K. Structures and functions of the membrane-damaging pore-forming proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:241-288. [PMID: 35034720 DOI: 10.1016/bs.apcsb.2021.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pore-forming proteins (PFPs) of the diverse life forms have emerged as the potent cell-killing entities owing to their specialized membrane-damaging properties. PFPs have the unique ability to perforate the plasma membranes of their target cells, and they exert this functionality by creating oligomeric pores in the membrane lipid bilayer. Pathogenic bacteria employ PFPs as toxins to execute their virulence mechanisms, whereas in the higher vertebrates PFPs are deployed as the part of the immune system and to generate inflammatory responses. PFPs are the unique dimorphic proteins that are generally synthesized as water-soluble molecules, and transform into membrane-inserted oligomeric pore assemblies upon interacting with the target membranes. In spite of sharing very little sequence similarity, PFPs from diverse organisms display incredible structural similarity. Yet, at the same time, structure-function mechanisms of the PFPs document remarkable versatility. Such notions establish PFPs as the fascinating model system to explore variety of unsolved issues pertaining to the structure-function paradigm of the proteins that interact and act in the membrane environment. In this article, we discuss our current understanding regarding the structural basis of the pore-forming functions of the diverse class of PFPs. We attempt to highlight the similarities and differences in their structures, membrane pore-formation mechanisms, and their implications for the various biological processes, ranging from the bacterial virulence mechanisms to the inflammatory immune response generation in the higher animals.
Collapse
Affiliation(s)
- Anish Kumar Mondal
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Kausik Chattopadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India.
| |
Collapse
|
38
|
Lukassen MV, Franc V, Hevler JF, Heck AJR. Similarities and differences in the structures and proteoform profiles of the complement proteins C6 and C7. Proteomics 2021; 21:e2000310. [PMID: 34241972 DOI: 10.1002/pmic.202000310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/24/2021] [Accepted: 07/05/2021] [Indexed: 11/08/2022]
Abstract
The human complement system provides a first line of defence against pathogens. It requires a well-orchestrated sequential assembly of an array of terminal complement components (C5, C6, C7, C8, and C9), ultimately forming the membrane attack complex (MAC). Although much information about MAC assembly is available, the structure of the soluble C7 has remained elusive. The complement proteins C7 and C6 share very high sequence homology and exhibit several conserved domains, disulphide bridges, and C-mannosylation sites. Here, we used an integrative structural MS-based approach combining native MS, glycopeptide-centric MS, in-gel cross-linking MS (IGX-MS) and structural modelling to describe structural features, including glycosylation, of human serum soluble C7. We compare this data with structural and glycosylation data for human serum C6. The new structural model for C7 shows that it adopts a compact conformation in solution. Although C6 and C7 share many similarities, our data reveals distinct O-, and N-linked glycosylation patterns in terms of location and glycan composition. Cumulatively, our data provide valuable new insight into the structure and proteoforms of C7, solving an essential piece of the puzzle in our understanding of MAC assembly.
Collapse
Affiliation(s)
- Marie V Lukassen
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, The Netherlands.,Netherlands Proteomics Center, The Netherlands
| | - Vojtech Franc
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, The Netherlands.,Netherlands Proteomics Center, The Netherlands
| | - Johannes F Hevler
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, The Netherlands.,Netherlands Proteomics Center, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, The Netherlands.,Netherlands Proteomics Center, The Netherlands
| |
Collapse
|
39
|
McMahon O, Hallam TM, Patel S, Harris CL, Menny A, Zelek WM, Widjajahakim R, Java A, Cox TE, Tzoumas N, Steel DHW, Shuttleworth VG, Smith-Jackson K, Brocklebank V, Griffiths H, Cree AJ, Atkinson JP, Lotery AJ, Bubeck D, Morgan BP, Marchbank KJ, Seddon JM, Kavanagh D. The rare C9 P167S risk variant for age-related macular degeneration increases polymerization of the terminal component of the complement cascade. Hum Mol Genet 2021; 30:1188-1199. [PMID: 33783477 PMCID: PMC8212764 DOI: 10.1093/hmg/ddab086] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 12/25/2022] Open
Abstract
Age-related macular degeneration (AMD) is a complex neurodegenerative eye disease with behavioral and genetic etiology and is the leading cause of irreversible vision loss among elderly Caucasians. Functionally significant genetic variants in the alternative pathway of complement have been strongly linked to disease. More recently, a rare variant in the terminal pathway of complement has been associated with increased risk, Complement component 9 (C9) P167S. To assess the functional consequence of this variant, C9 levels were measured in two independent cohorts of AMD patients. In both cohorts, it was demonstrated that the P167S variant was associated with low C9 plasma levels. Further analysis showed that patients with advanced AMD had elevated sC5b-9 compared to those with non-advanced AMD, although this was not associated with the P167S polymorphism. Electron microscopy of membrane attack complexes (MACs) generated using recombinantly produced wild type or P167S C9 demonstrated identical MAC ring structures. In functional assays, the P167S variant displayed a higher propensity to polymerize and a small increase in its ability to induce hemolysis of sheep erythrocytes when added to C9-depleted serum. The demonstration that this C9 P167S AMD risk polymorphism displays increased polymerization and functional activity provides a rationale for the gene therapy trials of sCD59 to inhibit the terminal pathway of complement in AMD that are underway.
Collapse
Affiliation(s)
- O McMahon
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - T M Hallam
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - S Patel
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - C L Harris
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - A Menny
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - W M Zelek
- Division of Infection and Immunity, School of Medicine, Systems Immunity Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - R Widjajahakim
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - A Java
- Divisions of Nephrology and Rheumatology, Department of Medicine, Washington University, St Louis, MO 63110, USA
| | - T E Cox
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - N Tzoumas
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - D H W Steel
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - V G Shuttleworth
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - K Smith-Jackson
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - V Brocklebank
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - H Griffiths
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - A J Cree
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - J P Atkinson
- Divisions of Nephrology and Rheumatology, Department of Medicine, Washington University, St Louis, MO 63110, USA
| | - A J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - D Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - B P Morgan
- Division of Infection and Immunity, School of Medicine, Systems Immunity Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - K J Marchbank
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - J M Seddon
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - D Kavanagh
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| |
Collapse
|
40
|
Zewde NT, Hsu RV, Morikis D, Palermo G. Systems Biology Modeling of the Complement System Under Immune Susceptible Pathogens. FRONTIERS IN PHYSICS 2021; 9:603704. [PMID: 35145963 PMCID: PMC8827490 DOI: 10.3389/fphy.2021.603704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The complement system is assembled from a network of proteins that function to bring about the first line of defense of the body against invading pathogens. However, complement deficiencies or invasive pathogens can hijack complement to subsequently increase susceptibility of the body to infections. Moreover, invasive pathogens are increasingly becoming resistant to the currently available therapies. Hence, it is important to gain insights into the highly dynamic interaction between complement and invading microbes in the frontlines of immunity. Here, we developed a mathematical model of the complement system composed of 670 ordinary differential equations with 328 kinetic parameters, which describes all three complement pathways (alternative, classical, and lectin) and includes description of mannose-binding lectin, collectins, ficolins, factor H-related proteins, immunoglobulin M, and pentraxins. Additionally, we incorporate two pathogens: (type 1) complement susceptible pathogen and (type 2) Neisseria meningitidis located in either nasopharynx or bloodstream. In both cases, we generate time profiles of the pathogen surface occupied by complement components and the membrane attack complex (MAC). Our model shows both pathogen types in bloodstream are saturated by complement proteins, whereas MACs occupy <<1.0% of the pathogen surface. Conversely, the MAC production in nasopharynx occupies about 1.5-10% of the total N. meningitidis surface, thus making nasal MAC levels at least about eight orders of magnitude higher. Altogether, we predict complement-imbalance, favoring overactivation, is associated with nasopharynx homeostasis. Conversely, orientating toward complement-balance may cause disruption to the nasopharynx homeostasis. Thus, for sporadic meningococcal disease, our model predicts rising nasal levels of complement regulators as early infection biomarkers.
Collapse
Affiliation(s)
- Nehemiah T. Zewde
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
| | - Rohaine V. Hsu
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
- Correspondence: Giulia Palermo, , Dimitrios Morikis,
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
- Department of Chemistry, University of California, Riverside, Riverside, CA, United States
- Correspondence: Giulia Palermo, , Dimitrios Morikis,
| |
Collapse
|
41
|
Roumia AF, Tsirigos KD, Theodoropoulou MC, Tamposis IA, Hamodrakas SJ, Bagos PG. OMPdb: A Global Hub of Beta-Barrel Outer Membrane Proteins. FRONTIERS IN BIOINFORMATICS 2021; 1:646581. [PMID: 36303794 PMCID: PMC9581022 DOI: 10.3389/fbinf.2021.646581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 03/18/2021] [Indexed: 11/14/2022] Open
Abstract
OMPdb (www.ompdb.org) was introduced as a database for β-barrel outer membrane proteins from Gram-negative bacteria in 2011 and then included 69,354 entries classified into 85 families. The database has been updated continuously using a collection of characteristic profile Hidden Markov Models able to discriminate between the different families of prokaryotic transmembrane β-barrels. The number of families has increased ultimately to a total of 129 families in the current, second major version of OMPdb. New additions have been made in parallel with efforts to update existing families and add novel families. Here, we present the upgrade of OMPdb, which from now on aims to become a global repository for all transmembrane β-barrel proteins, both eukaryotic and bacterial.
Collapse
Affiliation(s)
- Ahmed F. Roumia
- Department of Computer Science and Biomedical Informatics, University of Thessaly, Lamia, Greece
| | | | | | - Ioannis A. Tamposis
- Department of Computer Science and Biomedical Informatics, University of Thessaly, Lamia, Greece
| | - Stavros J. Hamodrakas
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Pantelis G. Bagos
- Department of Computer Science and Biomedical Informatics, University of Thessaly, Lamia, Greece
- *Correspondence: Pantelis G. Bagos
| |
Collapse
|
42
|
Abstract
CryoEM has become the method of choice for determining the structure of large macromolecular complexes in multiple conformations, at resolutions where unambiguous atomic models can be built. Two effects that have limited progress in single-particle cryoEM are (i) beam-induced movement during image acquisition and (ii) protein adsorption and denaturation at the air-water interface during specimen preparation. While beam-induced movement now appears to have been resolved by all-gold specimen support grids with very small holes, surface effects at the air-water interface are a persistent problem. Strategies to overcome these effects include the use of alternative support films and new techniques for specimen deposition. We examine the future potential of recording perfect images of biological samples for routine structure determination at atomic resolution.
Collapse
|
43
|
Gilbert RJC. Electron microscopy as a critical tool in the determination of pore forming mechanisms in proteins. Methods Enzymol 2021; 649:71-102. [PMID: 33712203 DOI: 10.1016/bs.mie.2021.01.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Electron microscopy has consistently played an important role in the description of pore-forming protein systems. The discovery of pore-forming proteins has depended on visualization of the structural pores formed by their oligomeric protein complexes, and as electron microscopy has advanced technologically so has the degree of insight it has been able to give. This review considers a large number of published studies of pore-forming complexes in prepore and pore states determined using single-particle cryo-electron microscopy. Sample isolation and preparation, imaging and image analysis, structure determination and optimization of results are all discussed alongside challenges which pore-forming proteins particularly present. The review also considers the use made of cryo-electron tomography to study pores within their membrane environment and which will prove an increasingly important approach for the future.
Collapse
Affiliation(s)
- Robert J C Gilbert
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
| |
Collapse
|
44
|
Spicer BA, Dunstone MA. Going full circle: Determining the structures of complement component 9. Methods Enzymol 2021; 649:103-123. [PMID: 33712184 DOI: 10.1016/bs.mie.2021.01.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Pore forming proteins (PFPs) undergo dramatic conformational changes to punch holes in the target membrane. These PFPs have the ability to self-assemble, by way of oligomerization, and have the capacity to transform from a water soluble state (commonly referred to as fluid phase) to a membrane adhered form. Accordingly, PFPs are metastable, that is they are inert until the right conditions cause the release of potential energy stored in the conformational fold leading to a vast structural rearrangement into a membrane-inserted oligomeric form. However, the metastable state of PFPs poses a problem of leading to aggregation and precipitation in conditions typically required for structural biology techniques. Here, we discuss the protein chemistry of the MACPF protein complement component 9 (C9). C9 is part of a larger complex assembly known as the membrane attack complex (MAC) that has been studied extensively for its ability to form pores in bacteria. An unusual artifact of human C9 is the ability to form a soluble oligomeric state of the channel portion of the MAC, called polyC9. PolyC9 formation does not require the presence of membranes or other complement factors. It is only in recent years that structural studies of the MAC have become successful owing to improved recombinant DNA expression systems and the improvement of high-resolution techniques (both X-ray crystallography and single particle cryo-EM). We discuss the expression and purification of recombinant C9, crystallization of the soluble monomeric form of C9 and the preparation of the oligomeric polyC9.
Collapse
Affiliation(s)
- Bradley A Spicer
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
| | - Michelle A Dunstone
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
| |
Collapse
|
45
|
Oungsakul P, Choi E, Shah AK, Mohamed A, O’Leary C, Duffy D, Hill MM, Bielefeldt-Ohmann H. Candidate Glycoprotein Biomarkers for Canine Visceral Hemangiosarcoma and Validation Using Semi-Quantitative Lectin/Immunohistochemical Assays. Vet Sci 2021; 8:vetsci8030038. [PMID: 33673507 PMCID: PMC7997418 DOI: 10.3390/vetsci8030038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/21/2021] [Accepted: 02/23/2021] [Indexed: 11/16/2022] Open
Abstract
Visceral hemangiosarcoma (HSA) is one of the more frequent cancers in dogs and has a high metastatic rate and poor prognosis, as clinical signs only become apparent in advanced stages of tumor development. In order to improve early and differential diagnostic capabilities and hence, prognosis for dogs with HSA, two types of biomarker are needed: a point-of-care diagnostic biomarker and a prognostic biomarker—preferentially based on samples obtained with minimally invasive methods. In this study, we applied a lectin magnetic bead array-coupled tandem mass spectrometry (LeMBA-MS/MS) workflow through discovery and validation phases to discover serum glycoprotein biomarker candidates for canine HSA. By this approach, we found that Datura stramonium (DSA), wheat germ agglutinin (WGA), Sambucus nigra (SNA), and Pisum sativum (PSA) lectins captured the highest number of validated candidate glycoproteins. Secondly, we independently validated serum LeMBA-MS/MS results by demonstrating the in situ relationship of lectin-binding with tumor cells. Using lectin-histochemistry and immunohistochemistry (IHC) for key proteins on tissues with HSA and semi-quantitation of the signals, we demonstrate that a combination of DSA histochemistry and IHC for complement C7 greatly increases the prospect of a more specific diagnosis of canine HSA.
Collapse
Affiliation(s)
- Patharee Oungsakul
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; (P.O.); (C.O.)
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; (E.C.); (A.K.S.); (D.D.); (M.M.H.)
| | - Eunju Choi
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; (E.C.); (A.K.S.); (D.D.); (M.M.H.)
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Alok K. Shah
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; (E.C.); (A.K.S.); (D.D.); (M.M.H.)
- QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia;
| | - Ahmed Mohamed
- QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia;
| | - Caroline O’Leary
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; (P.O.); (C.O.)
| | - David Duffy
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; (E.C.); (A.K.S.); (D.D.); (M.M.H.)
- QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia;
| | - Michelle M. Hill
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; (E.C.); (A.K.S.); (D.D.); (M.M.H.)
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Helle Bielefeldt-Ohmann
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; (P.O.); (C.O.)
- School of Chemistry & Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
- Correspondence:
| |
Collapse
|
46
|
More than a Pore: Nonlytic Antimicrobial Functions of Complement and Bacterial Strategies for Evasion. Microbiol Mol Biol Rev 2021; 85:85/1/e00177-20. [PMID: 33504655 DOI: 10.1128/mmbr.00177-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The complement system is an evolutionarily ancient defense mechanism against foreign substances. Consisting of three proteolytic activation pathways, complement converges on a common effector cascade terminating in the formation of a lytic pore on the target surface. The classical and lectin pathways are initiated by pattern recognition molecules binding to specific ligands, while the alternative pathway is constitutively active at low levels in circulation. Complement-mediated killing is essential for defense against many Gram-negative bacterial pathogens, and genetic deficiencies in complement can render individuals highly susceptible to infection, for example, invasive meningococcal disease. In contrast, Gram-positive bacteria are inherently resistant to the direct bactericidal activity of complement due to their thick layer of cell wall peptidoglycan. However, complement also serves diverse roles in immune defense against all bacteria by flagging them for opsonization and killing by professional phagocytes, synergizing with neutrophils, modulating inflammatory responses, regulating T cell development, and cross talk with coagulation cascades. In this review, we discuss newly appreciated roles for complement beyond direct membrane lysis, incorporate nonlytic roles of complement into immunological paradigms of host-pathogen interactions, and identify bacterial strategies for complement evasion.
Collapse
|
47
|
Koopman JJE, van Essen MF, Rennke HG, de Vries APJ, van Kooten C. Deposition of the Membrane Attack Complex in Healthy and Diseased Human Kidneys. Front Immunol 2021; 11:599974. [PMID: 33643288 PMCID: PMC7906018 DOI: 10.3389/fimmu.2020.599974] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/21/2020] [Indexed: 12/11/2022] Open
Abstract
The membrane attack complex-also known as C5b-9-is the end-product of the classical, lectin, and alternative complement pathways. It is thought to play an important role in the pathogenesis of various kidney diseases by causing cellular injury and tissue inflammation, resulting in sclerosis and fibrosis. These deleterious effects are, consequently, targeted in the development of novel therapies that inhibit the formation of C5b-9, such as eculizumab. To clarify how C5b-9 contributes to kidney disease and to predict which patients benefit from such therapy, knowledge on deposition of C5b-9 in the kidney is essential. Because immunohistochemical staining of C5b-9 has not been routinely conducted and never been compared across studies, we provide a review of studies on deposition of C5b-9 in healthy and diseased human kidneys. We describe techniques to stain deposits and compare the occurrence of deposits in healthy kidneys and in a wide spectrum of kidney diseases, including hypertensive nephropathy, diabetic nephropathy, membranous nephropathy, IgA nephropathy, lupus nephritis, C3 glomerulopathy, and thrombotic microangiopathies such as the atypical hemolytic uremic syndrome, vasculitis, interstitial nephritis, acute tubular necrosis, kidney tumors, and rejection of kidney transplants. We summarize how these deposits are related with other histological lesions and clinical characteristics. We evaluate the prognostic relevance of these deposits in the light of possible treatment with complement inhibitors.
Collapse
Affiliation(s)
- Jacob J E Koopman
- Division of Renal Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Mieke F van Essen
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Helmut G Rennke
- Division of Renal Pathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Aiko P J de Vries
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Cees van Kooten
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| |
Collapse
|
48
|
Heesterbeek DAC, Muts RM, van Hensbergen VP, de Saint Aulaire P, Wennekes T, Bardoel BW, van Sorge NM, Rooijakkers SHM. Outer membrane permeabilization by the membrane attack complex sensitizes Gram-negative bacteria to antimicrobial proteins in serum and phagocytes. PLoS Pathog 2021; 17:e1009227. [PMID: 33481964 PMCID: PMC7886145 DOI: 10.1371/journal.ppat.1009227] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/16/2021] [Accepted: 12/07/2020] [Indexed: 12/12/2022] Open
Abstract
Infections with Gram-negative bacteria form an increasing risk for human health due to antibiotic resistance. Our immune system contains various antimicrobial proteins that can degrade the bacterial cell envelope. However, many of these proteins do not function on Gram-negative bacteria, because the impermeable outer membrane of these bacteria prevents such components from reaching their targets. Here we show that complement-dependent formation of Membrane Attack Complex (MAC) pores permeabilizes this barrier, allowing antimicrobial proteins to cross the outer membrane and exert their antimicrobial function. Specifically, we demonstrate that MAC-dependent outer membrane damage enables human lysozyme to degrade the cell wall of E. coli. Using flow cytometry and confocal microscopy, we show that the combination of MAC pores and lysozyme triggers effective E. coli cell wall degradation in human serum, thereby altering the bacterial cell morphology from rod-shaped to spherical. Completely assembled MAC pores are required to sensitize E. coli to the antimicrobial actions of lysozyme and other immune factors, such as Human Group IIA-secreted Phospholipase A2. Next to these effects in a serum environment, we observed that the MAC also sensitizes E. coli to more efficient degradation and killing inside human neutrophils. Altogether, this study serves as a proof of principle on how different players of the human immune system can work together to degrade the complex cell envelope of Gram-negative bacteria. This knowledge may facilitate the development of new antimicrobials that could stimulate or work synergistically with the immune system. In this paper we identified how different players of the human immune system cooperate to degrade the complex cell envelope of Gram-negative bacteria. The outer membrane of Gram-negative bacteria forms an impermeable barrier for various antimicrobial proteins of the immune system. Here we show that complement-dependent Membrane Attack Complex (MAC) formation permeabilizes this barrier, allowing otherwise impermeable antimicrobial proteins to reach their targets underneath the outer membrane. Specifically, we show that outer membrane damage by the MAC allows lysozyme to degrade the peptidoglycan layer, and secreted phospholipase A2-IIA to hydrolyze the bacterial inner membrane. MAC formation also sensitizes Gram-negative bacteria to more efficient degradation and killing inside human neutrophils. Altogether, this knowledge may guide the development of new antimicrobial strategies to treat infections caused by Gram-negative bacteria.
Collapse
Affiliation(s)
- Dani A. C. Heesterbeek
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Remy M. Muts
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Vincent P. van Hensbergen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Pieter de Saint Aulaire
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Tom Wennekes
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Bart W. Bardoel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Nina M. van Sorge
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Suzan H. M. Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- * E-mail:
| |
Collapse
|
49
|
Hevler JF, Lukassen MV, Cabrera-Orefice A, Arnold S, Pronker MF, Franc V, Heck AJR. Selective cross-linking of coinciding protein assemblies by in-gel cross-linking mass spectrometry. EMBO J 2021; 40:e106174. [PMID: 33459420 PMCID: PMC7883291 DOI: 10.15252/embj.2020106174] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/03/2020] [Accepted: 12/10/2020] [Indexed: 12/18/2022] Open
Abstract
Cross-linking mass spectrometry has developed into an important method to study protein structures and interactions. The in-solution cross-linking workflows involve time and sample consuming steps and do not provide sensible solutions for differentiating cross-links obtained from co-occurring protein oligomers, complexes, or conformers. Here we developed a cross-linking workflow combining blue native PAGE with in-gel cross-linking mass spectrometry (IGX-MS). This workflow circumvents steps, such as buffer exchange and cross-linker concentration optimization. Additionally, IGX-MS enables the parallel analysis of co-occurring protein complexes using only small amounts of sample. Another benefit of IGX-MS, demonstrated by experiments on GroEL and purified bovine heart mitochondria, is the substantial reduction of undesired over-length cross-links compared to in-solution cross-linking. We next used IGX-MS to investigate the complement components C5, C6, and their hetero-dimeric C5b6 complex. The obtained cross-links were used to generate a refined structural model of the complement component C6, resembling C6 in its inactivated state. This finding shows that IGX-MS can provide new insights into the initial stages of the terminal complement pathway.
Collapse
Affiliation(s)
- Johannes F Hevler
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands.,Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Marie V Lukassen
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands.,Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Alfredo Cabrera-Orefice
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Susanne Arnold
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Matti F Pronker
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands.,Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Vojtech Franc
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands.,Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands.,Netherlands Proteomics Center, Utrecht, The Netherlands
| |
Collapse
|
50
|
Khakzad H, Happonen L, Tran Van Nhieu G, Malmström J, Malmström L. In vivo Cross-Linking MS of the Complement System MAC Assembled on Live Gram-Positive Bacteria. Front Genet 2021; 11:612475. [PMID: 33488677 PMCID: PMC7820895 DOI: 10.3389/fgene.2020.612475] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/24/2020] [Indexed: 11/27/2022] Open
Abstract
Protein–protein interactions are central in many biological processes, but they are challenging to characterize, especially in complex samples. Protein cross-linking combined with mass spectrometry (MS) and computational modeling is gaining increased recognition as a viable tool in protein interaction studies. Here, we provide insights into the structure of the multicomponent human complement system membrane attack complex (MAC) using in vivo cross-linking MS combined with computational macromolecular modeling. We developed an affinity procedure followed by chemical cross-linking on human blood plasma using live Streptococcus pyogenes to enrich for native MAC associated with the bacterial surface. In this highly complex sample, we identified over 100 cross-linked lysine–lysine pairs between different MAC components that enabled us to present a quaternary model of the assembled MAC in its native environment. Demonstrating the validity of our approach, this MAC model is supported by existing X-ray crystallographic and electron cryo-microscopic models. This approach allows the study of protein–protein interactions in native environment mimicking their natural milieu. Its high potential in assisting and refining data interpretation in electron cryo-tomographic experiments will be discussed.
Collapse
Affiliation(s)
- Hamed Khakzad
- Equipe Signalisation Calcique et Infections Microbiennes, Ecole Normale Supérieure Paris-Saclay, Gif-sur-Yvette, France.,Institut National de la Santé et de la Recherche Médicale U1282, Gif-sur-Yvette, France
| | - Lotta Happonen
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Guy Tran Van Nhieu
- Equipe Signalisation Calcique et Infections Microbiennes, Ecole Normale Supérieure Paris-Saclay, Gif-sur-Yvette, France.,Institut National de la Santé et de la Recherche Médicale U1282, Gif-sur-Yvette, France
| | - Johan Malmström
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Lars Malmström
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| |
Collapse
|