1
|
de Boer ECW, Thielen AJF, Langereis JD, Kamp A, Brouwer MC, Oskam N, Jongsma ML, Baral AJ, Spaapen RM, Zeerleder S, Vidarsson G, Rispens T, Wouters D, Pouw RB, Jongerius I. The contribution of the alternative pathway in complement activation on cell surfaces depends on the strength of classical pathway initiation. Clin Transl Immunology 2023; 12:e1436. [PMID: 36721662 PMCID: PMC9881211 DOI: 10.1002/cti2.1436] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 10/31/2022] [Accepted: 12/23/2022] [Indexed: 01/28/2023] Open
Abstract
Objectives The complement system is an important component of innate immunity. The alternative pathway (AP) amplification loop is considered an essential feed forward mechanism for complement activation. However, the role of the AP in classical pathway (CP) activation has only been studied in ELISA settings. Here, we investigated its contribution on physiologically relevant surfaces of human cells and bacterial pathogens and in antibody-mediated complement activation, including in autoimmune haemolytic anaemia (AIHA) setting with autoantibodies against red blood cells (RBCs). Methods We evaluated the contribution of the AP to complement responses initiated through the CP on human RBCs by serum of AIHA patients and recombinant antibodies. Moreover, we studied complement activation on Neisseria meningitidis and Escherichia coli. The effect of the AP was examined using either AP-depleted sera or antibodies against factor B and factor D. Results We show that the amplification loop is redundant when efficient CP activation takes place. This is independent of the presence of membrane-bound complement regulators. The role of the AP may become significant when insufficient CP complement activation occurs, but this depends on antibody levels and (sub)class. Our data indicate that therapeutic intervention in the amplification loop will most likely not be effective to treat antibody-mediated diseases. Conclusion The AP can be bypassed through efficient CP activation. The AP amplification loop has a role in complement activation during conditions of modest activation via the CP, when it can allow for efficient complement-mediated killing.
Collapse
Affiliation(s)
- Esther CW de Boer
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's HospitalAmsterdam University Medical CentreAmsterdamThe Netherlands
| | - Astrid JF Thielen
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Jeroen D Langereis
- Laboratory of Medical Immunology, Radboud Institute for Molecular Life SciencesRadboudumcNijmegenThe Netherlands,Radboud Center for Infectious Diseases, RadboudumcNijmegenThe Netherlands
| | - Angela Kamp
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Mieke C Brouwer
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Nienke Oskam
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Marlieke L Jongsma
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - April J Baral
- Translational and Clinical Research InstituteNewcastle upon TyneUK
| | - Robbert M Spaapen
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Sacha Zeerleder
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Department of Hematology, Luzerner KantonsspitalLuzern and University of BernBernSwitzerland,Department for BioMedical ResearchUniversity of BernBernSwitzerland
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, Sanquin Research, and Landsteiner LaboratoryAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Diana Wouters
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Centre for Infectious Disease ControlNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Richard B Pouw
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Sanquin Health SolutionsAmsterdamThe Netherlands
| | - Ilse Jongerius
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's HospitalAmsterdam University Medical CentreAmsterdamThe Netherlands
| |
Collapse
|
2
|
Hallam TM, Cox TE, Smith-Jackson K, Brocklebank V, Baral AJ, Tzoumas N, Steel DH, Wong EKS, Shuttleworth VG, Lotery AJ, Harris CL, Marchbank KJ, Kavanagh D. A novel method for real-time analysis of the complement C3b:FH:FI complex reveals dominant negative CFI variants in age-related macular degeneration. Front Immunol 2022; 13:1028760. [PMID: 36643920 PMCID: PMC9832388 DOI: 10.3389/fimmu.2022.1028760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/14/2022] [Indexed: 12/29/2022] Open
Abstract
Age-related macular degeneration (AMD) is linked to 2 main disparate genetic pathways: a chromosome 10 risk locus and the alternative pathway (AP) of complement. Rare genetic variants in complement factor H (CFH; FH) and factor I (CFI; FI) are associated with AMD. FH acts as a soluble cofactor to facilitate FI's cleavage and inactivation of the central molecule of the AP, C3b. For personalised treatment, sensitive assays are required to define the functional significance of individual AP genetic variants. Generation of recombinant FI for functional analysis has thus far been constrained by incomplete processing resulting in a preparation of active and inactive protein. Using an internal ribosomal entry site (IRES)-Furin-CFI expression vector, fully processed FI was generated with activity equivalent to serum purified FI. By generating FI with an inactivated serine protease domain (S525A FI), a real-time surface plasmon resonance assay of C3b:FH:FI complex formation for characterising variants in CFH and CFI was developed and correlated well with standard assays. Using these methods, we further demonstrate that patient-associated rare genetic variants lacking enzymatic activity (e.g. CFI I340T) may competitively inhibit the wild-type FI protein. The dominant negative effect identified in inactive factor I variants could impact on the pharmacological replacement of FI currently being investigated for the treatment of dry AMD.
Collapse
Affiliation(s)
- Thomas M. Hallam
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Thomas E. Cox
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Kate Smith-Jackson
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Vicky Brocklebank
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - April J. Baral
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Nikolaos Tzoumas
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - David H. Steel
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,Sunderland Eye Infirmary, Sunderland, United Kingdom,Biosciences Institute, Newcastle University, International Centre for Life, Newcastle upon Tyne, United Kingdom
| | - Edwin K. S. Wong
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Victoria G. Shuttleworth
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Claire L. Harris
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Kevin J. Marchbank
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - David Kavanagh
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom,National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom,National Institute for Health and Care Research (NIHR) Newcastle Biomedical Research Centre, Biomedical Research Building, Newcastle upon Tyne, United Kingdom,*Correspondence: David Kavanagh,
| |
Collapse
|
3
|
Rivera JF, Baral AJ, Nadat F, Boyd G, Smyth R, Patel H, Burman EL, Alameer G, Boxall SA, Jackson BR, Baxter EJ, Laslo P, Green AR, Kent DG, Mullally A, Chen E. Zinc-dependent multimerization of mutant calreticulin is required for MPL binding and MPN pathogenesis. Blood Adv 2021; 5:1922-1932. [PMID: 33821991 PMCID: PMC8045488 DOI: 10.1182/bloodadvances.2020002402] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 02/17/2021] [Indexed: 01/30/2023] Open
Abstract
Calreticulin (CALR) is mutated in the majority of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs). Mutant CALR (CALRdel52) exerts its effect by binding to the thrombopoietin receptor MPL to cause constitutive activation of JAK-STAT signaling. In this study, we performed an extensive mutagenesis screen of the CALR globular N-domain and revealed 2 motifs critical for CALRdel52 oncogenic activity: (1) the glycan-binding lectin motif and (2) the zinc-binding domain. Further analysis demonstrated that the zinc-binding domain was essential for formation of CALRdel52 multimers, which was a co-requisite for MPL binding. CALRdel52 variants incapable of binding zinc were unable to homomultimerize, form CALRdel52-MPL heteromeric complexes, or stimulate JAK-STAT signaling. Finally, treatment with zinc chelation disrupted CALRdel52-MPL complexes in hematopoietic cells in conjunction with preferential eradication of cells expressing CALRdel52 relative to cells expressing other MPN oncogenes. In addition, zinc chelators exhibited a therapeutic effect in preferentially impairing growth of CALRdel52-mutant erythroblasts relative to unmutated erythroblasts in primary cultures of MPN patients. Together, our data implicate zinc as an essential cofactor for CALRdel52 oncogenic activity by enabling CALRdel52 multimerization and interaction with MPL, and suggests that perturbation of intracellular zinc levels may represent a new approach to abrogate the oncogenic activity of CALRdel52 in the treatment of MPNs.
Collapse
Affiliation(s)
- Jeanne F Rivera
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
- Division of Haematology and Immunology, Leeds Institute for Medical Research, St. James's University Hospital, University of Leeds, Leeds, United Kingdom
| | - April J Baral
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - Fatima Nadat
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - Grace Boyd
- York Biomedical Research Institute, University of York, York, United Kingdom
| | - Rachael Smyth
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - Hershna Patel
- School of Life Sciences, University of Westminster, London, United Kingdom
| | - Emma L Burman
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - Ghadah Alameer
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - Sally A Boxall
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - Brian R Jackson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
| | - E Joanna Baxter
- Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Peter Laslo
- Division of Haematology and Immunology, Leeds Institute for Medical Research, St. James's University Hospital, University of Leeds, Leeds, United Kingdom
| | - Anthony R Green
- Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
- Wellcome MRC Cambridge Stem Cell Institute and
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - David G Kent
- York Biomedical Research Institute, University of York, York, United Kingdom
| | - Ann Mullally
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
- Broad Institute, Cambridge, MA; and
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
| | - Edwin Chen
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and
- School of Life Sciences, University of Westminster, London, United Kingdom
| |
Collapse
|