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Sonnentag SJ, Dopler A, Kleiner K, Garg BK, Mannes M, Späth N, Akilah A, Höchsmann B, Schrezenmeier H, Anliker M, Boyanapalli R, Huber-Lang M, Schmidt CQ. Triple-fusion protein (TriFu): A potent, targeted, enzyme-like inhibitor of all three complement activation pathways. J Biol Chem 2024; 300:105784. [PMID: 38401844 PMCID: PMC11065761 DOI: 10.1016/j.jbc.2024.105784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024] Open
Abstract
The introduction of a therapeutic anti-C5 antibody into clinical practice in 2007 inspired a surge into the development of complement-targeted therapies. This has led to the recent approval of a C3 inhibitory peptide, an antibody directed against C1s and a full pipeline of several complement inhibitors in preclinical and clinical development. However, no inhibitor is available that efficiently inhibits all three complement initiation pathways and targets host cell surface markers as well as complement opsonins. To overcome this, we engineered a novel fusion protein combining selected domains of the three natural complement regulatory proteins decay accelerating factor, factor H and complement receptor 1. Such a triple fusion complement inhibitor (TriFu) was recombinantly expressed and purified alongside multiple variants and its building blocks. We analyzed these proteins for ligand binding affinity and decay acceleration activity by surface plasmon resonance. Additionally, we tested complement inhibition in several in vitro/ex vivo assays using standard classical and alternative pathway restricted hemolysis assays next to hemolysis assays with paroxysmal nocturnal hemoglobinuria erythrocytes. A novel in vitro model of the alternative pathway disease C3 glomerulopathy was established to evaluate the potential of the inhibitors to stop C3 deposition on endothelial cells. Next to the novel engineered triple fusion variants which inactivate complement convertases in an enzyme-like fashion, stoichiometric complement inhibitors targeting C3, C5, factor B, and factor D were tested as comparators. The triple fusion approach yielded a potent complement inhibitor that efficiently inhibits all three complement initiation pathways while targeting to surface markers.
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Affiliation(s)
- Sophia J Sonnentag
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Arthur Dopler
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Katharina Kleiner
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | | | - Marco Mannes
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Nadja Späth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Amira Akilah
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | | | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christoph Q Schmidt
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Centre, Ulm, Germany; Institute of Pharmacy, Biochemical Pharmacy Group, Martin Luther University Halle-Wittenberg, Halle, Germany.
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Peixoto VP, Prudêncio C, Vieira M, Sousa SF. Evaluation of the impact of two C5 genetic variants on C5-eculizumab complex stability at the molecular level. J Biomol Struct Dyn 2024:1-10. [PMID: 38529903 DOI: 10.1080/07391102.2024.2331091] [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: 11/29/2023] [Accepted: 03/11/2024] [Indexed: 03/27/2024]
Abstract
Complement C5 is the target of the monoclonal antibody eculizumab, used in complement dysregulating disorders, like the rare disease Paroxysmal Nocturnal Hemoglobinuria (PNH). PNH is an acquired hematopoietic stem cell condition characterized by aberrant destruction of erythrocytes, chronic hemolytic anemia, and thromboembolism propensity. C5 is a protein component of the complement system which is part of the immune system of the body and plays a prominent role in the destruction of red blood cells, misidentifying them as a threat. This work describes the application of molecular dynamics simulations to the study of the underlying interactions between complement C5 and eculizumab. This study also reveals the importance of single nucleotide polymorphisms on C5 protein concerning the effective inhibition of the mAB, involving the mechanistic events taking place at the interface spots of the complex. The predicted conformational change in the C5 Arg885/His/Cys mutation has implications on the protein's interaction with eculizumab, compromising their compatibility. The acquired insights into the conformational changes, dynamics, flexibility, and interactions shed light on the knowledge of the function of this biomolecule providing answers about the poor response to the treatment in PNH patient carriers of the mutations. By investigating the intricate dynamics, significant connections between C5 and eculizumab can be uncovered. Such insights may aid in the creation of novel compounds or lead to the enhancement of eculizumab's efficacy.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Vanda P Peixoto
- Chemical and Biomolecular Sciences, School of Health, Polytechnic Institute of Porto, Porto, Portugal
- Center for Translational Health and Medical Biotechnology Research (TBIO), Polytechnic Institute of Porto, Porto, Portugal
- LAQV/REQUIMTE, BioSIM - Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Cristina Prudêncio
- Chemical and Biomolecular Sciences, School of Health, Polytechnic Institute of Porto, Porto, Portugal
- Center for Translational Health and Medical Biotechnology Research (TBIO), Polytechnic Institute of Porto, Porto, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, Porto, Portugal
| | - Mónica Vieira
- Chemical and Biomolecular Sciences, School of Health, Polytechnic Institute of Porto, Porto, Portugal
- Center for Translational Health and Medical Biotechnology Research (TBIO), Polytechnic Institute of Porto, Porto, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, Porto, Portugal
| | - Sérgio F Sousa
- LAQV/REQUIMTE, BioSIM - Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
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Chen JY, Zhang L, Yang M, Hughes ED, Freeman ZT, Saunders TL, Lin F. Development of a C3 Humanized Rat as a New Model for Evaluating Novel C3 Inhibitors. J Innate Immun 2023; 16:56-65. [PMID: 38035563 PMCID: PMC10786584 DOI: 10.1159/000534963] [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: 07/03/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
INTRODUCTION C3 is central for all complement activation pathways, thus making it an attractive therapeutic target. Many C3-targeted agents are under extensive development with one already approved for clinical use. However, most, if not all, C3 inhibitors are human or nonhuman primate C3-specific, making evaluating their efficacies in vivo before a clinical trial extremely difficult and costly. METHODS We first studied the compatibility of human C3 in the rat complement system, then developed a C3 humanized rat using the CRISPR/Cas9 technology. We thoroughly characterized the resultant human C3 humanized rats and tested the treatment efficacy of an established primate-specific C3 inhibitor in a model of complement-mediated hemolysis in the C3 humanized rats. RESULTS We found that supplementing human C3 protein into the C3-deficient rat blood restored its complement activity, which was inhibited by rat factor H or compstatin, suggesting that human C3 is compatible to the rat complement system. The newly developed C3 humanized rats appeared healthy and expressed human but not rat C3 without detectable spontaneous C3 activation. More importantly, complement-mediated hemolysis in the C3 humanized rats was also inhibited by compstatin both in vitro and in vivo. CONCLUSION The successfully developed C3 humanized rats provided a much-desired rodent model to evaluate novel C3 inhibitors in vivo as potential drugs.
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Affiliation(s)
- Jin Y. Chen
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Lingjun Zhang
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Maojing Yang
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | | | - Zachary T. Freeman
- Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI, USA
| | - Thomas L. Saunders
- Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI, USA
| | - Feng Lin
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
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Mannes M, Pechtl V, Hafner S, Dopler A, Eriksson O, Manivel VA, Wohlgemuth L, Messerer DAC, Schrezenmeier H, Ekdahl KN, Nilsson B, Jacobsen EM, Hoenig M, Huber-Lang M, Braun CK, Schmidt CQ. Complement and platelets: prothrombotic cell activation requires membrane attack complex-induced release of danger signals. Blood Adv 2023; 7:6367-6380. [PMID: 37428869 PMCID: PMC10625899 DOI: 10.1182/bloodadvances.2023010817] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 07/12/2023] Open
Abstract
Complement activation in the diseases paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS) results in cytolysis and fatal thrombotic events, which are largely refractory to anticoagulation and/or antiplatelet therapy. Anticomplement therapy, however, efficiently prevents thrombotic events in PNH and aHUS, but the underlying mechanisms remain unresolved. We show that complement-mediated hemolysis in whole blood induces platelet activation similarly to activation by adenosine 5'-diphosphate (ADP). Blockage of C3 or C5 abolished platelet activation. We found that human platelets failed to respond functionally to the anaphylatoxins C3a and C5a. Instead, complement activation did lead to prothrombotic cell activation in the whole blood when membrane attack complex (MAC)-mediated cytolysis occurred. Consequently, we demonstrate that ADP receptor antagonists efficiently inhibited platelet activation, although full complement activation, which causes hemolysis, occurred. By using an established model of mismatched erythrocyte transfusions in rats, we crossvalidated these findings in vivo using the complement inhibitor OmCI and cobra venom factor. Consumptive complement activation in this animal model only led to a thrombotic phenotype when MAC-mediated cytolysis occurred. In conclusion, complement activation only induces substantial prothrombotic cell activation if terminal pathway activation culminates in MAC-mediated release of intracellular ADP. These results explain why anticomplement therapy efficiently prevents thromboembolisms without interfering negatively with hemostasis.
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Affiliation(s)
- Marco Mannes
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Veronika Pechtl
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
| | - Susanne Hafner
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
| | - Arthur Dopler
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
| | - Oskar Eriksson
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Vivek Anand Manivel
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Lisa Wohlgemuth
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | | | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm and Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, University Hospital of Ulm and German Red Cross Blood Service Baden-Württemberg–Hessen, Ulm, Germany
| | - Kristina N. Ekdahl
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Bo Nilsson
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Eva-Maria Jacobsen
- Department of Pediatrics and Adolescent Medicine, University Hospital of Ulm, Ulm, Germany
| | - Manfred Hoenig
- Department of Pediatrics and Adolescent Medicine, University Hospital of Ulm, Ulm, Germany
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christian K. Braun
- Department of Pediatrics and Adolescent Medicine, University Hospital of Ulm, Ulm, Germany
| | - Christoph Q. Schmidt
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
- Institute of Pharmacy, Biochemical Pharmacy Group, Martin Luther University Halle-Wittenberg, Halle, Germany
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5
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Schmidt CQ, Smith RJH. Protein therapeutics and their lessons: Expect the unexpected when inhibiting the multi-protein cascade of the complement system. Immunol Rev 2023; 313:376-401. [PMID: 36398537 PMCID: PMC9852015 DOI: 10.1111/imr.13164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Over a century after the discovery of the complement system, the first complement therapeutic was approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). It was a long-acting monoclonal antibody (aka 5G1-1, 5G1.1, h5G1.1, and now known as eculizumab) that targets C5, specifically preventing the generation of C5a, a potent anaphylatoxin, and C5b, the first step in the eventual formation of membrane attack complex. The enormous clinical and financial success of eculizumab across four diseases (PNH, atypical hemolytic uremic syndrome (aHUS), myasthenia gravis (MG), and anti-aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD)) has fueled a surge in complement therapeutics, especially targeting diseases with an underlying complement pathophysiology for which anti-C5 therapy is ineffective. Intensive research has also uncovered challenges that arise from C5 blockade. For example, PNH patients can still face extravascular hemolysis or pharmacodynamic breakthrough of complement suppression during complement-amplifying conditions. These "side" effects of a stoichiometric inhibitor like eculizumab were unexpected and are incompatible with some of our accepted knowledge of the complement cascade. And they are not unique to C5 inhibition. Indeed, "exceptions" to the rules of complement biology abound and have led to unprecedented and surprising insights. In this review, we will describe initial, present and future aspects of protein inhibitors of the complement cascade, highlighting unexpected findings that are redefining some of the mechanistic foundations upon which the complement cascade is organized.
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Affiliation(s)
- Christoph Q. Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Richard J. H. Smith
- Departments of Internal Medicine and Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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6
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Luzzatto L. Closing remarks. Am J Hematol 2022; 98 Suppl 4:S90-S92. [PMID: 36322103 DOI: 10.1002/ajh.26776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/30/2022] [Accepted: 10/12/2022] [Indexed: 12/12/2022]
Affiliation(s)
- Lucio Luzzatto
- Muhimbili University of Health and Allied Sciences Dar‐es‐Salaam Tanzania
- University of Florence Florence Italy
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7
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Anliker M, Drees D, Loacker L, Hafner S, Griesmacher A, Hoermann G, Fux V, Schennach H, Hörtnagl P, Dopler A, Schmidt S, Bellmann-Weiler R, Weiss G, Marx-Hofmann A, Körper S, Höchsmann B, Schrezenmeier H, Schmidt CQ. Upregulation of Checkpoint Ligand Programmed Death-Ligand 1 in Patients with Paroxysmal Nocturnal Hemoglobinuria Explained by Proximal Complement Activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1248-1258. [PMID: 35173033 DOI: 10.4049/jimmunol.2100031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 12/17/2021] [Indexed: 12/12/2022]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hemolytic disease driven by impaired complement regulation. Mutations in genes encoding the enzymes that build the GPI anchors are causative, with somatic mutations in the PIG-A gene occurring most frequently. As a result, the important membrane-bound complement regulators CD55 and CD59 are missing on the affected hematopoietic stem cells and their progeny, rendering those cells vulnerable to complement attack. Immune escape mechanisms sparing affected PNH stem cells from removal are suspected in the PNH pathogenesis, but molecular mechanisms have not been elucidated. We hypothesized that exuberant complement activity in PNH results in enhanced immune checkpoint interactions, providing a molecular basis for the potential immune escape in PNH. In a series of PNH patients, we found increased expression levels of the checkpoint ligand programmed death-ligand 1 (PD-L1) on granulocytes and monocytes, as well as in the plasma of PNH patients. Mechanistically, we demonstrate that complement activation leading to the decoration of particles/cells with C3- and/or C4-opsonins increased PD-L1 expression on neutrophils and monocytes as shown for different in vitro models of classical or alternative pathway activation. We further establish in vitro that complement inhibition at the level of C3, but not C5, inhibits the alternative pathway-mediated upregulation of PD-L1 and show by means of soluble PD-L1 that this observation translates into the clinical situation when PNH patients are treated with either C3 or C5 inhibitors. Together, the presented data show that the checkpoint ligand PD-L1 is increased in PNH patients, which correlates with proximal complement activation.
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Affiliation(s)
- Markus Anliker
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Daniela Drees
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Lorin Loacker
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Susanne Hafner
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Andrea Griesmacher
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Gregor Hoermann
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria.,MLL Munich Leukemia Laboratory, Munich, Germany
| | - Vilmos Fux
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Harald Schennach
- Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, Innsbruck, Austria
| | - Paul Hörtnagl
- Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, Innsbruck, Austria
| | - Arthur Dopler
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Stefan Schmidt
- Department of Internal Medicine V, Medical University of Innsbruck, Innsbruck, Austria; and
| | - Rosa Bellmann-Weiler
- Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Austria
| | - Astrid Marx-Hofmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Sixten Körper
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; .,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany;
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Gurnari C, Nautiyal I, Pagliuca S. Current Opinions on the Clinical Utility of Ravulizumab for the Treatment of Paroxysmal Nocturnal Hemoglobinuria. Ther Clin Risk Manag 2021; 17:1343-1351. [PMID: 34934322 PMCID: PMC8684432 DOI: 10.2147/tcrm.s273360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/28/2021] [Indexed: 01/15/2023] Open
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder of hematopoietic stem cells genetically defined by the acquisition of somatic mutations in the X-linked phosphatidylinositol glycan anchor biosynthesis, class A (PIGA) gene. PIGA is essential for the synthesis of glycosyl phosphatidylinositol (GPI) anchor proteins and its mutations result in a deficiency of such molecules on the membrane of blood cells derived from the mutant clone. In particular, the lack of the GPI-linked complement regulatory proteins CD55 and CD59 is responsible for the increased sensitivity of PNH erythrocytes to complement-mediated destruction. Indeed, the classical clinical picture of PNH includes signs and symptoms of intravascular hemolysis along with variable degrees of cytopenia and a strong tendency to thrombosis, hallmarks of the disease. Before the introduction of anti-complement inhibitors, PNH was characterized by a high mortality primarily due to thrombotic events. The approval of the terminal anti-complement inhibitor eculizumab in 2007 introduced a paradigm shift in the treatment of the disease with improvement of the chronic hemolytic process and dramatic reduction of the thrombotic rate. However, eculizumab has a relatively short half-life when considering a life-long treatment, with obvious consequences as to the quality of life of treated patients necessitating relatively frequent drug administrations. Moreover, up to 30% of PNH patients undergoing eculizumab therapy show a suboptimal response, continuing to require red cell transfusions because of extravascular hemolysis or breakthrough hemolytic episodes. In 2019, the FDA approved the second-generation C5 inhibitor ravulizumab, a long-lasting agent with a better control of disease manifestations. Herein, we discuss the use of ravulizumab in PNH, its differences with first-generation C5 inhibitors, the research evidence supporting the safety and efficacy of this drug and its impact on costs for health systems and quality of life of PNH patients.
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Affiliation(s)
- Carmelo Gurnari
- Department of Translational Hematology and Oncology Research, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, OH, USA
- Department of Biomedicine and Prevention, PhD in Immunology, Molecular Medicine and Applied Biotechnology, University of Rome Tor Vergata, Rome, Italy
| | - Ishani Nautiyal
- Department of Translational Hematology and Oncology Research, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Simona Pagliuca
- Department of Translational Hematology and Oncology Research, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, OH, USA
- ED561 Hematology, Oncogenesis and Biotherapies, University of Paris, Paris, France
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9
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Complement and the prothrombotic state. Blood 2021; 139:1954-1972. [PMID: 34415298 DOI: 10.1182/blood.2020007206] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 06/08/2021] [Indexed: 11/20/2022] Open
Abstract
In 2007 and 2009 the regulatory approval of the first-in-class complement inhibitor Eculizumab has revolutionized the clinical management of two rare, life-threatening clinical conditions: paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). While being completely distinct diseases affecting blood cells and the glomerulus, PNH and aHUS remarkably share several features in their etiology and clinical presentation. An imbalance between complement activation and regulation at host surfaces underlies both diseases precipitating in severe thrombotic events that are largely resistant to anti-coagulant and/or anti-platelet therapies. Inhibition of the common terminal complement pathway by Eculizumab prevents the frequently occurring thrombotic events responsible for the high mortality and morbidity observed in patients not treated with anti-complement therapy. While many in vitro and ex vivo studies elaborate numerous different molecular interactions between complement activation products and hemostasis, this review focuses on the clinical evidence that links these two fields in humans. Several non-infectious conditions with known complement involvement are scrutinized for common patterns concerning a prothrombotic statues and the occurrence of certain complement activation levels. Next to PNH and aHUS, germline encoded CD59 or CD55 deficiency (the latter causing the disease Complement Hyperactivation, Angiopathic thrombosis, and Protein-Losing Enteropathy; CHAPLE), autoimmune hemolytic anemia (AIHA), (catastrophic) anti-phospholipid syndrome (APS, CAPS) and C3 glomerulopathy are considered. Parallels and distinct features among these conditions are discussed against the background of thrombosis, complement activation, and potential complement diagnostic and therapeutic avenues.
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10
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Complement inhibition at the level of C3 or C5: mechanistic reasons for ongoing terminal pathway activity. Blood 2021; 137:443-455. [PMID: 33507296 DOI: 10.1182/blood.2020005959] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Blocking the terminal complement pathway with the C5 inhibitor eculizumab has revolutionized the clinical management of several complement-mediated diseases and has boosted the clinical development of new inhibitors. Data on the C3 inhibitor Compstatin and the C5 inhibitors eculizumab and Coversin reported here demonstrate that C3/C5 convertases function differently from prevailing concepts. Stoichiometric C3 inhibition failed to inhibit C5 activation and lytic activity during strong classical pathway activation, demonstrating a "C3 bypass" activation of C5. We show that, instead of C3b, surface-deposited C4b alone can also recruit and prime C5 for consecutive proteolytic activation. Surface-bound C3b and C4b possess similar affinities for C5. By demonstrating that the fluid phase convertase C3bBb is sufficient to cleave C5 as long as C5 is bound on C3b/C4b-decorated surfaces, we show that surface fixation is necessary only for the C3b/C4b opsonins that prime C5 but not for the catalytic convertase unit C3bBb. Of note, at very high C3b densities, we observed membrane attack complex formation in absence of C5-activating enzymes. This is explained by a conformational activation in which C5 adopts a C5b-like conformation when bound to densely C3b-opsonized surfaces. Stoichiometric C5 inhibitors failed to prevent conformational C5 activation, which explains the clinical phenomenon of residual C5 activity documented for different inhibitors of C5. The new insights into the mechanism of C3/C5 convertases provided here have important implications for the development and therapeutic use of complement inhibitors as well as the interpretation of former clinical and preclinical data.
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11
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Fattizzo B, Kulasekararaj AG. Second-Generation C5 Inhibitors for Paroxysmal Nocturnal Hemoglobinuria. BioDrugs 2021; 34:149-158. [PMID: 31916226 DOI: 10.1007/s40259-019-00401-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The C5 targeting monoclonal antibody eculizumab has changed the natural history of paroxysmal nocturnal hemoglobinuria (PNH) in the last 10 years. However, some unmet clinical needs persist, including persistent anemia with some patients requiring transfusions, incomplete C5 inhibition with breakthrough hemolysis (because of pharmacokinetic or pharmacodynamic issues such as infections, as well as conditions increasing complement activity), the underlying bone marrow failure, and the significant burden on patient quality of life (intravenous route of administration and frequency of infusions). Moreover, a subclass of patients carries C5 polymorphisms resistant to eculizumab inhibition. Several second-generation C5 inhibitors are under active study to overcome unmet clinical needs with eculizumab. Current strategies encompass increasing drug half-life, developing small molecule inhibitors of C5, and exploring new routes of administration (including subcutaneous and oral agents). In this review, we summarize available data on second-generation C5 inhibitors in PNH, including novel monoclonal antibodies, a small interfering RNA, and small molecules.
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Affiliation(s)
- Bruno Fattizzo
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico di Milano e Università degli studi di Milano, Milan, Italy
| | - Austin G Kulasekararaj
- Department of Haematological Medicine, King's College Hospital, National Institute of Health Research/Wellcome King's Clinical Research Facility, London, SE5 9RS, UK.
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12
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Kulasekararaj AG, Hill A, Langemeijer S, Wells R, González Fernández FA, Gaya A, Ojeda Gutierrez E, Piatek CI, Mitchell L, Usuki K, Bosi A, Brodsky RA, Ogawa M, Yu J, Ortiz S, Röth A, Lee JW, Peffault de Latour R. One-year outcomes from a phase 3 randomized trial of ravulizumab in adults with paroxysmal nocturnal hemoglobinuria who received prior eculizumab. Eur J Haematol 2021; 106:389-397. [PMID: 33301613 PMCID: PMC8246907 DOI: 10.1111/ejh.13564] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 11/29/2022]
Abstract
Ravulizumab every 8 weeks showed non‐inferiority to eculizumab every 2 weeks in a 26‐week, phase 3, randomized controlled trial in adults with paroxysmal nocturnal hemoglobinuria (PNH) who were clinically stable on eculizumab (NCT03056040). We report results from the first 26 weeks of the extension period in which patients continued ravulizumab (n = 96) or switched from eculizumab to ravulizumab (n = 95). At week 52, mean (SD) lactate dehydrogenase levels increased 8.8% (29%) with ravulizumab‐ravulizumab and 5.8% (27%) with eculizumab‐ravulizumab from primary evaluation period baseline. During the extension period, four patients (ravulizumab‐ravulizumab, n = 3; eculizumab‐ravulizumab, n = 1) experienced breakthrough hemolysis, but none associated with serum free C5 ≥ 0.5 μg/mL. Mean Functional Assessment of Chronic Illness Therapy (FACIT)‐Fatigue scores remained stable through week 52. During the extension period, proportions of patients avoiding transfusion remained stable (ravulizumab‐ravulizumab, 86.5%; eculizumab‐ravulizumab, 83.2%); 81.2% and 81.1%, respectively, had stabilized hemoglobin. All patients maintained serum free C5 levels < 0.5 μg/mL. Adverse events were generally similar between groups, and rates were lower in the extension period. Adults with PNH on stable eculizumab therapy who received ravulizumab over 52 weeks experienced durable efficacy, with consistent efficacy in patients who received eculizumab during the primary evaluation period and then switched to ravulizumab. Ravulizumab was well tolerated.
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Affiliation(s)
- Austin G Kulasekararaj
- Department of Haematological Medicine, King's College Hospital, National Institute of Health Research/Wellcome King's Clinical Research Facility and King's College London, London, UK
| | - Anita Hill
- Department of Haematology, Leeds Teaching Hospitals, Leeds, UK
| | | | - Richard Wells
- Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - F Ataúlfo González Fernández
- Department of Hematology, Hospital Clinico Universitario San Carlos, The Clınic Institute of Haematological and Oncological Diseases, Madrid, Spain
| | - Anna Gaya
- Department of Hematology, Hospital Clinic de Barcelona, Barcelona, Spain
| | | | - Caroline I Piatek
- Jane Anne Nohl Division of Hematology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | | | - Alberto Bosi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Robert A Brodsky
- The John Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Ji Yu
- Alexion Pharmaceuticals, Inc., Boston, MA, USA
| | | | - Alexander Röth
- Department of Hematology, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Jong Wook Lee
- Department of Hematology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - Régis Peffault de Latour
- Bone Marrow Transplantation Unit, Saint Louis Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,French Reference Center for Aplastic Anemia and Paroxysmal Nocturnal Hemoglobinuria, Saint Louis Hospital and University Paris Diderot, Paris, France.,Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation, Leiden, the Netherlands
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13
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Zelek WM, Morgan BP. Monoclonal Antibodies Capable of Inhibiting Complement Downstream of C5 in Multiple Species. Front Immunol 2020; 11:612402. [PMID: 33424866 PMCID: PMC7793867 DOI: 10.3389/fimmu.2020.612402] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022] Open
Abstract
Better understanding of roles of complement in pathology has fuelled an explosion of interest in complement-targeted therapeutics. The C5-blocking monoclonal antibody (mAb) eculizumab, the first of the new wave of complement blocking drugs, was FDA approved for treatment of Paroxysmal Nocturnal Hemoglobinuria in 2007; its expansion into other diseases has been slow and remains restricted to rare and ultra-rare diseases such as atypical hemolytic uremic syndrome. The success of eculizumab has provoked other Pharma to follow this well-trodden track and made C5 blockade the busiest area of complement drug development. C5 blockade inhibits generation of C5a and C5b, the former an anaphylatoxin, the latter the nidus for formation of the pro-inflammatory membrane attack complex. In order to use anti-complement drugs in common complement-driven diseases, more affordable and equally effective therapeutics are needed. To address this, we explored complement inhibition downstream of C5. Novel blocking mAbs targeting C7 and/or the C5b-7 complex were generated, identified using high throughput functional assays and specificity confirmed by immunochemical assays and surface plasmon resonance (SPR). Selected mAbs were tested in rodents to characterize pharmacokinetics, and therapeutic capacity. Administration of a mouse C7-selective mAb to wildtype mice, or a human C7 specific mAb to C7-deficient mice reconstituted with human C7, completely inhibited serum lytic activity for >48 h. The C5b-7 complex selective mAb 2H2, most active in rat serum, efficiently inhibited serum lytic activity in vivo for over a week from a single low dose (10 mg/kg); this mAb effectively blocked disease and protected muscle endplates from destruction in a rat myasthenia model. Targeting C7 and C7-containing terminal pathway intermediates is an innovative therapeutic approach, allowing lower drug dose and lower product cost, that will facilitate the expansion of complement therapeutics to common diseases.
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Affiliation(s)
- Wioleta M Zelek
- Systems Immunity Research Institute, Division of Infection and Immunity and Dementia Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
| | - B Paul Morgan
- Systems Immunity Research Institute, Division of Infection and Immunity and Dementia Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
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14
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Ort M, Dingemanse J, van den Anker J, Kaufmann P. Treatment of Rare Inflammatory Kidney Diseases: Drugs Targeting the Terminal Complement Pathway. Front Immunol 2020; 11:599417. [PMID: 33362783 PMCID: PMC7758461 DOI: 10.3389/fimmu.2020.599417] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
The complement system comprises the frontline of the innate immune system. Triggered by pathogenic surface patterns in different pathways, the cascade concludes with the formation of a membrane attack complex (MAC; complement components C5b to C9) and C5a, a potent anaphylatoxin that elicits various inflammatory signals through binding to C5a receptor 1 (C5aR1). Despite its important role in pathogen elimination, priming and recruitment of myeloid cells from the immune system, as well as crosstalk with other physiological systems, inadvertent activation of the complement system can result in self-attack and overreaction in autoinflammatory diseases. Consequently, it constitutes an interesting target for specialized therapies. The paradigm of safe and efficacious terminal complement pathway inhibition has been demonstrated by the approval of eculizumab in paroxysmal nocturnal hematuria. In addition, complement contribution in rare kidney diseases, such as lupus nephritis, IgA nephropathy, atypical hemolytic uremic syndrome, C3 glomerulopathy, or antineutrophil cytoplasmic antibody-associated vasculitis has been demonstrated. This review summarizes the involvement of the terminal effector agents of the complement system in these diseases and provides an overview of inhibitors for complement components C5, C5a, C5aR1, and MAC that are currently in clinical development. Furthermore, a link between increased complement activity and lung damage in severe COVID-19 patients is discussed and the potential for use of complement inhibitors in COVID-19 is presented.
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Affiliation(s)
- Marion Ort
- Department of Clinical Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland.,Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel (UKBB), University of Basel, Basel, Switzerland
| | - Jasper Dingemanse
- Department of Clinical Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - John van den Anker
- Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel (UKBB), University of Basel, Basel, Switzerland.,Division of Clinical Pharmacology, Children's National Hospital, Washington, DC, United States
| | - Priska Kaufmann
- Department of Clinical Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
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15
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Zhang L, Chen JY, Kerr C, Cobb BA, Maciejewski JP, Lin F. Reduced red blood cell surface level of Factor H as a mechanism underlying paroxysmal nocturnal hemoglobinuria. Leukemia 2020; 35:1176-1187. [PMID: 32814838 PMCID: PMC7892643 DOI: 10.1038/s41375-020-1008-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/21/2020] [Accepted: 07/28/2020] [Indexed: 11/09/2022]
Abstract
The absence of the cell-surface complement inhibitors CD55 and CD59 is considered the mechanism underlying the complement-mediated destruction of affected red blood cells (RBCs) in paroxysmal nocturnal hemoglobinuria (PNH) patients, but Factor H (FH), a fluid-phase complement inhibitor, has also been proposed to be involved. However, the status of FH on the PNH patient RBC surface is unclear and its precise role in PNH pathogenesis remains to be further defined. In this study, we identified significantly lower levels of surface-bound FH on the affected CD59- RBCs than on the unaffected CD59+ RBCs. Although this reduction in surface-bound FH on PNH RBCs was accompanied by decreased surface sialic acid levels, the enzymatic removal of sialic acids from these RBCs did not significantly affect the levels of surface-bound FH. We further observed higher surface levels of FH on the C3b/iC3b/C3dhigh RBCs than on C3b/iC3b/C3dlow RBCs within the affected PNH RBCs of patients treated with eculizumab. Finally, we determined that enhanced surface levels of FH on CD55/CD59-deficient RBCs from mice and PNH patients protected against complement-mediated hemolysis. Taken together, our results suggest that a reduced surface level of FH is another important mechanism underlying the pathogenesis of PNH.
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Affiliation(s)
- Lingjun Zhang
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jin Y Chen
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Cassandra Kerr
- Translational Hematology and Oncology Research Department, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH, USA
| | - Brian A Cobb
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Jaroslaw P Maciejewski
- Translational Hematology and Oncology Research Department, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH, USA
| | - Feng Lin
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
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Chen JY, Galwankar NS, Emch HN, Menon SS, Cortes C, Thurman JM, Merrill SA, Brodsky RA, Ferreira VP. Properdin Is a Key Player in Lysis of Red Blood Cells and Complement Activation on Endothelial Cells in Hemolytic Anemias Caused by Complement Dysregulation. Front Immunol 2020; 11:1460. [PMID: 32793201 PMCID: PMC7387411 DOI: 10.3389/fimmu.2020.01460] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 06/04/2020] [Indexed: 12/18/2022] Open
Abstract
The complement system alternative pathway (AP) can be activated excessively in inflammatory diseases, particularly when there is defective complement regulation. For instance, deficiency in complement regulators CD55 and CD59, leads to paroxysmal nocturnal hemoglobinuria (PNH), whereas Factor H mutations predispose to atypical hemolytic uremic syndrome (aHUS), both causing severe thrombohemolysis. Despite eculizumab being the treatment for these diseases, benefits vary considerably among patients. Understanding the molecular mechanisms involved in complement regulation is essential for developing new treatments. Properdin, the positive AP regulator, is essential for complement amplification by stabilizing enzymatic convertases. In this study, the role of properdin in red blood cell (RBC) lysis and endothelial cell opsonization in these AP-mediated diseases was addressed by developing in vitro assays using PNH patient RBCs and human primary endothelial cells, where the effects of inhibiting properdin, using novel monoclonal antibodies (MoAbs) that we generated and characterized, were compared to other complement inhibitors. In in vitro models of PNH, properdin inhibition prevented hemolysis of patient PNH type II and III RBCs more than inhibition of Factor B, C3, and C5 (>17-fold, or >81-fold, or >12-fold lower molar IC90 values, respectively). When tested in an in vitro aHUS hemolysis model, the anti-properdin MoAbs had 11-fold, and 86-fold lower molar IC90 values than inhibition of Factor B, or C3, respectively (P < 0.0001). When comparing target/inhibitor ratios in all hemolysis assays, inhibiting properdin was at least as efficient as the other complement inhibitors in most cases. In addition, using in vitro endothelial cell assays, the data indicate a critical novel role for properdin in promoting complement activation on human endothelial cells exposed to heme (a hemolysis by-product) and rH19-20 (to inhibit Factor H cell-surface protection), as occurs in aHUS. Inhibition of properdin or C3 in this system significantly reduced C3 fragment deposition by 75%. Altogether, the data indicate properdin is key in promoting RBC lysis and complement activation on human endothelial cells, contributing to the understanding of PNH and aHUS pathogenesis. Further studies to determine therapeutic values of inhibiting properdin in complement-mediated diseases, in particular those that are characterized by AP dysregulation, are warranted.
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Affiliation(s)
- Jin Y Chen
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Neeti S Galwankar
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Heather N Emch
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Smrithi S Menon
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Claudio Cortes
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Joshua M Thurman
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Samuel A Merrill
- Section of Hematology/Oncology, Department of Medicine, West Virginia University School of Medicine, Morgantown, WV, United States
| | - Robert A Brodsky
- Division of Hematology, Department of Medicine, John Hopkins University School of Medicine, Baltimore, MD, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
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17
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Goldberg BS, Ackerman ME. Antibody-mediated complement activation in pathology and protection. Immunol Cell Biol 2020; 98:305-317. [PMID: 32142167 DOI: 10.1111/imcb.12324] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/27/2020] [Accepted: 03/03/2020] [Indexed: 01/10/2023]
Abstract
Antibody-dependent complement activity is associated not only with autoimmune morbidity, but also with antitumor efficacy. In infectious disease, both recombinant monoclonal antibodies and polyclonal antibodies generated in natural adaptive responses can mediate complement activity to protective, therapeutic or disease-enhancing effect. Recent advances have contributed to the structural resolution of molecular complexes involved in antibody-mediated complement activation, defining the avid nature of participating interactions and pointing to how antibody isotype, subclass, hinge flexibility, glycosylation state, amino acid sequence and the contextual nature of the cognate antigen/epitope are all factors that can determine complement activity through impact on antibody multimerization and subsequent recruitment of complement component 1q. Beyond the efficiency of activation, complement activation products interact with various cell types that mediate immune adherence, trafficking, immune education and innate functions. Similarly, depending on the anatomical location and extent of activation, complement can support homeostatic restoration or be leveraged by pathogens or neoplasms to enhance infection or promote tumorigenic microenvironments, respectively. Advances in means to suppress complement activation by intravenous immunoglobulin (IVIG), IVIG mimetics and complement-intervening antibodies represent proven and promising exploratory therapeutic strategies, while antibody engineering has likewise offered frameworks to enhance, eliminate or isolate complement activation to interrogate in vivo mechanisms of action. Such strategies promise to support the optimization of antibody-based drugs that are able to tackle emerging and difficult-to-treat diseases by improving our understanding of the synergistic and antagonistic relationships between antibody mechanisms mediated by Fc receptors, direct binding and the products of complement activation.
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Affiliation(s)
| | - Margaret E Ackerman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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