1
|
Pedersen DV, Lorentzen J, Andersen GR. Structural studies offer a framework for understanding the role of properdin in the alternative pathway and beyond. Immunol Rev 2023; 313:46-59. [PMID: 36097870 PMCID: PMC10087229 DOI: 10.1111/imr.13129] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Structures of alternative pathway proteins have offered a comprehensive structural basis for understanding the molecular mechanisms governing activation and regulation of the amplification pathway of the complement cascade. Although properdin (FP) is required in vivo to sustain a functional alternative pathway, structural studies have been lagging behind due to the extended structure and polydisperse nature of FP. We review recent progress with respect to structure determination of FP and its proconvertase/convertase complexes. These structures identify in detail regions in C3b, factor B and FP involved in their mutual interactions. Structures of FP oligomers obtained by integrative studies have shed light on how FP activity depends on its oligomerization state. The accumulated structural knowledge allows us to rationalize the effect of point mutations causing FP deficiency. The structural basis for FP inhibition by the tick CirpA proteins is reviewed and the potential of alphafold2 predictions for understanding the interaction of FP with other tick proteins and the NKp46 receptor on host immune cells is discussed. The accumulated structural knowledge forms a comprehensive basis for understanding molecular interactions involving FP, pathological conditions arising from low levels of FP, and the molecular strategies used by ticks to suppress the alternative pathway.
Collapse
Affiliation(s)
| | - Josefine Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| |
Collapse
|
2
|
Pedersen DV, Gadeberg TAF, Thomas C, Wang Y, Joram N, Jensen RK, Mazarakis SMM, Revel M, El Sissy C, Petersen SV, Lindorff-Larsen K, Thiel S, Laursen NS, Fremeaux-Bacchi V, Andersen GR. Structural Basis for Properdin Oligomerization and Convertase Stimulation in the Human Complement System. Front Immunol 2019; 10:2007. [PMID: 31507604 PMCID: PMC6713926 DOI: 10.3389/fimmu.2019.02007] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/07/2019] [Indexed: 12/05/2022] Open
Abstract
Properdin (FP) is a positive regulator of the immune system stimulating the activity of the proteolytically active C3 convertase C3bBb in the alternative pathway of the complement system. Here we present two crystal structures of FP and two structures of convertase bound FP. A structural core formed by three thrombospondin repeats (TSRs) and a TB domain harbors the convertase binding site in FP that mainly interacts with C3b. Stabilization of the interaction between the C3b C-terminus and the MIDAS bound Mg2+ in the Bb protease by FP TSR5 is proposed to underlie FP convertase stabilization. Intermolecular contacts between FP and the convertase subunits suggested by the structure were confirmed by binding experiments. FP is shown to inhibit C3b degradation by FI due to a direct competition for a common binding site on C3b. FP oligomers are held together by two sets of intermolecular contacts, where the first is formed by the TB domain from one FP molecule and TSR4 from another. The second and largest interface is formed by TSR1 and TSR6 from the same two FP molecules. Flexibility at four hinges between thrombospondin repeats is suggested to enable the oligomeric, polydisperse, and extended architecture of FP. Our structures rationalize the effects of mutations associated with FP deficiencies and provide a structural basis for the analysis of FP function in convertases and its possible role in pattern recognition.
Collapse
Affiliation(s)
- Dennis V. Pedersen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Aarhus, Denmark
| | - Trine A. F. Gadeberg
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Aarhus, Denmark
| | - Caroline Thomas
- Service d'Oncologie Pédiatrique, CHU Nantes, Hôpital Mère Enfant, Nantes, France
| | - Yong Wang
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Nicolas Joram
- Service de Réanimation Pédiatrique, CHU Nantes, Nantes, France
| | - Rasmus K. Jensen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Aarhus, Denmark
| | - Sofia M. M. Mazarakis
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Aarhus, Denmark
| | - Margot Revel
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Université Paris Diderot, Paris, France
| | - Carine El Sissy
- Service d'Immunologie Biologique, Assistance Publique – Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France
| | | | - Kresten Lindorff-Larsen
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Nick S. Laursen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Aarhus, Denmark
| | - Véronique Fremeaux-Bacchi
- Service d'Immunologie Biologique, Assistance Publique – Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France
| | - Gregers R. Andersen
- Department of Molecular Biology and Genetics, Center for Structural Biology, Aarhus University, Aarhus, Denmark
| |
Collapse
|
3
|
Michels MAHM, Volokhina EB, van de Kar NCAJ, van den Heuvel LPWJ. The role of properdin in complement-mediated renal diseases: a new player in complement-inhibiting therapy? Pediatr Nephrol 2019; 34:1349-1367. [PMID: 30141176 PMCID: PMC6579773 DOI: 10.1007/s00467-018-4042-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 07/31/2018] [Accepted: 08/03/2018] [Indexed: 12/16/2022]
Abstract
Properdin is known as the only positive regulator of the complement system. Properdin promotes the activity of this defense system by stabilizing its key enzymatic complexes: the complement alternative pathway (AP) convertases. Besides, some studies have indicated a role for properdin as an initiator of complement activity. Though the AP is a powerful activation route of the complement system, it is also involved in a wide variety of autoimmune and inflammatory diseases, many of which affect the kidneys. The role of properdin in regulating complement in health and disease has not received as much appraisal as the many negative AP regulators, such as factor H. Historically, properdin deficiency has been strongly associated with an increased risk for meningococcal disease. Yet only recently had studies begun to link properdin to other complement-related diseases, including renal diseases. In the light of the upcoming complement-inhibiting therapies, it is interesting whether properdin can be a therapeutic target to attenuate AP-mediated injury. A full understanding of the basic concepts of properdin biology is therefore needed. Here, we first provide an overview of the function of properdin in health and disease. Then, we explore its potential as a therapeutic target for the AP-associated renal diseases C3 glomerulopathy, atypical hemolytic uremic syndrome, and proteinuria-induced tubulointerstitial injury. Considering current knowledge, properdin-inhibiting therapy seems promising in certain cases. However, knowing the complexity of properdin's role in renal pathologies in vivo, further research is required to clarify the exact potential of properdin-targeted therapy in complement-mediated renal diseases.
Collapse
Affiliation(s)
- Marloes A. H. M. Michels
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands
| | - Elena B. Volokhina
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands ,Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands
| | - Nicole C. A. J. van de Kar
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands
| | - Lambertus P. W. J. van den Heuvel
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands ,Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands ,Department of Pediatrics/Pediatric Nephrology and Department of Development & Regeneration, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium
| |
Collapse
|
4
|
Poppelaars F, Gaya da Costa M, Berger SP, Assa S, Meter-Arkema AH, Daha MR, van Son WJ, Franssen CFM, Seelen MAJ. Strong predictive value of mannose-binding lectin levels for cardiovascular risk of hemodialysis patients. J Transl Med 2016; 14:236. [PMID: 27495980 PMCID: PMC4974702 DOI: 10.1186/s12967-016-0995-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/28/2016] [Indexed: 01/10/2023] Open
Abstract
Background Hemodialysis patients have higher rates of cardiovascular morbidity and mortality compared to the general population. Mannose-binding lectin (MBL) plays an important role in the development of cardiovascular disease. In addition, hemodialysis alters MBL concentration and functional activity. The present study determines the predictive value of MBL levels for future cardiac events (C-event), cardiovascular events (CV-event) and all-cause mortality in HD patients. Methods We conducted a prospective study of 107 patients on maintenance hemodialysis. Plasma MBL, properdin, C3d and sC5b-9 was measured before and after one dialysis session. The association with future C-events, CV-events, and all-cause mortality was evaluated using Cox regression models. Results During median follow-up of 27 months, 36 participants developed 21 C-events and 36 CV-events, whereas 37 patients died. The incidence of C-events and CV-events was significantly higher in patients with low MBL levels (<319 ng/mL, lower quartile). In fully adjusted models, low MBL level was independently associated with increased CV-events (hazard ratio 3.98; 95 % CI 1.88–8.24; P < 0.001) and C-events (hazard ratio 3.96; 95 % CI 1.49–10.54; P = 0.006). No association was found between low MBL levels and all-cause mortality. Furthermore, MBL substantially improved risk prediction for CV-events beyond currently used clinical markers. Conclusions Low MBL levels are associated with a higher risk for future C-events and CV-events. Therefore, MBL levels may help to identify hemodialysis patients who are at risk to develop cardiovascular disease. Electronic supplementary material The online version of this article (doi:10.1186/s12967-016-0995-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Felix Poppelaars
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Mariana Gaya da Costa
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Stefan P Berger
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Solmaz Assa
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Anita H Meter-Arkema
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Mohamed R Daha
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Nephrology, Leiden University Medical Center, University of Leiden, Leiden, The Netherlands
| | - Willem J van Son
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Casper F M Franssen
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marc A J Seelen
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
5
|
Siezenga MA, van der Geest RN, Mallat MJK, Rabelink TJ, Daha MR, Berger SP. Urinary properdin excretion is associated with intrarenal complement activation and poor renal function. Nephrol Dial Transplant 2009; 25:1157-61. [PMID: 19934084 DOI: 10.1093/ndt/gfp630] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Proteinuria predicts progressive renal failure. Next to being a progression marker, non-selective proteinuria itself is thought to be toxic to the tubulointerstitium. In proteinuric states, activation of filtered or locally produced complement is toxic for renal tubular cells and likely contributes to the progression of renal failure. Recent experimental evidence suggests an important role for properdin in promoting intrarenal complement activation. We measured properdin in proteinuric urine and assessed its relation with urinary SC5b-9 levels, the soluble form of the effector phase of complement activation. METHODS Seventy patients with renal disease of different origin but all with a protein excretion of at least 1 g/day were studied. Urinary properdin and SC5b-9 levels were measured using an ELISA technique. RESULTS Properdin was detectable in the urine of 37 patients (53%). These subjects had higher urinary SC5b-9 levels {median 0.50 U/ml [interquartile range (IQR) 0.13-1.81] versus 0.049 U/ml (IQR 0.024-0.089), P < 0.001}. When adjusted for proteinuria and renal function, properdin excretion was strongly associated with increased urinary SC5b-9 levels (odds ratio 16.2, 95% confidence interval 3.6-74.4). Properdin excretion was associated with worse renal function. CONCLUSION Our results suggest that urinary properdin excretion enhances intrarenal complement activation and thus may contribute to the progression of renal damage in proteinuric states.
Collapse
Affiliation(s)
- Machiel A Siezenga
- Leiden University Medical Center, Department of Nephrology, Leiden, The Netherlands.
| | | | | | | | | | | |
Collapse
|
6
|
Linton SM, Morgan BP. Properdin deficiency and meningococcal disease--identifying those most at risk. Clin Exp Immunol 1999; 118:189-91. [PMID: 10540177 PMCID: PMC1905414 DOI: 10.1046/j.1365-2249.1999.01057.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/1999] [Indexed: 11/20/2022] Open
Affiliation(s)
- S M Linton
- Complement Biology Group, Department of Medical Biochemistry, UWCM, Cardiff, UK
| | | |
Collapse
|
7
|
Fijen CA, van den Bogaard R, Schipper M, Mannens M, Schlesinger M, Nordin FG, Dankert J, Daha MR, Sjöholm AG, Truedsson L, Kuijper EJ. Properdin deficiency: molecular basis and disease association. Mol Immunol 1999; 36:863-7. [PMID: 10698340 DOI: 10.1016/s0161-5890(99)00107-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- C A Fijen
- Department of Medical Microbiology, AMC/University of Amsterdam, The Netherlands.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Fredrikson GN, Gullstrand B, Westberg J, Sjöholm AG, Uhlén M, Truedsson L. Expression of properdin in complete and incomplete deficiency: normal in vitro synthesis by monocytes in two cases with properdin deficiency type II due to distinct mutations. J Clin Immunol 1998; 18:272-82. [PMID: 9710744 DOI: 10.1023/a:1027385806871] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Three properdin deficiency phenotypes have been reported--complete deficiency (type I), incomplete deficiency (type II), and dysfunction of properdin protein (type III)--all associated with increased susceptibility to meningococcal disease. Expression of properdin by monocytes was examined in type I deficiency and in two unrelated cases with type II deficiency, one from a Swedish and one from a Danish family. The properdin gene in the Danish family contained a point mutation in exon 8 causing a Gln316-->Arg substitution, distinct from a point mutation in exon 4 previously found in the Swedish family. Both genes coded for physicochemically abnormal properdin molecules with changed hydrophilicity. Monocytes from all the properdin-deficient individuals produced properdin mRNA in a normal fashion. In type I deficiency no intracellular or secreted properdin was found, indicating rapid intracellular degradation. Monocytes from the males with type II deficiency expressed and secreted properdin normally. Properdin in sera with type II deficiency showed abnormal oligomerization with a relative decrease in properdin trimers and tetramers. Our findings suggest that the low concentration of circulating properdin in type II deficiency is caused by increased extracellular catabolism. Analysis of properdin expression by monocytes in a female carrier in the family with properdin deficiency type I provided direct evidence of lyonization at the cellular level.
Collapse
Affiliation(s)
- G N Fredrikson
- Department of Medical Microbiology, Lund University, Sweden
| | | | | | | | | | | |
Collapse
|
9
|
Truedsson L, Westberg J, Fredrikson GN, Sjöholm AG, Kuijper EJ, Fijen CA, Späth PJ, Uhlén M. Human properdin deficiency has a heterogeneous genetic background. IMMUNOPHARMACOLOGY 1997; 38:203-6. [PMID: 9476131 DOI: 10.1016/s0162-3109(97)00087-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- L Truedsson
- Department of Med. Microbiology, Lund University, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
10
|
van Dam AP, Oei A, Jaspars R, Fijen C, Wilske B, Spanjaard L, Dankert J. Complement-mediated serum sensitivity among spirochetes that cause Lyme disease. Infect Immun 1997; 65:1228-36. [PMID: 9119456 PMCID: PMC175122 DOI: 10.1128/iai.65.4.1228-1236.1997] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Borrelia burgdorferi-related isolates were tested for their sensitivity to normal human serum (NHS) and their ability to activate complement. By dark-field microscopy, electron microscopy, and subsurface plating, it was shown that exposure of a Borrelia garinii isolate to 10% or more NHS resulted in immobilization, blebbing, and killing of the spirochetes. These effects were mediated by complement, since they were not seen after heat treatment of NHS, in the presence of EDTA, or in an agammaglobulinemic serum. All seven B. garinii type 5 or 6 and all four VS116/M19 strains were serum sensitive, whereas all eight Borrelia afzelii, five of eight B. garinii type 4, and three of seven B. burgdorferi sensu stricto isolates were serum resistant. The other isolates were partially serum sensitive. Four serum-sensitive B. garinii isolates had been isolated from human cerebrospinal fluid. Most likely, activation of both the alternative pathway and the classical pathway of complement was involved, since bactericidal activity was diminished in properdin-deficient sera as well as in a C1q-depleted serum and in a C4-deficient serum. Bactericidal activity could be restored when a serum lacking C1q or C4 was mixed with a properdin-deficient serum. Isolates with various genetic backgrounds were equally able to activate C3 as measured by enzyme-linked immunosorbent assay. In the presence of Mg-EGTA, C3 was activated by all isolates after exposure to > or = 10% NHS. This study shows that B. burgdorferi-related spirochetes can be either serum sensitive or serum resistant in vitro and that this characteristic is associated with their genetic background.
Collapse
Affiliation(s)
- A P van Dam
- Department of Medical Microbiology, Academic Medical Centre, University of Amsterdam, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|