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Holers VM, Tomlinson S, Kulik L, Atkinson C, Rohrer B, Banda N, Thurman JM. New therapeutic and diagnostic opportunities for injured tissue-specific targeting of complement inhibitors and imaging modalities. Semin Immunol 2016; 28:260-7. [PMID: 27282113 DOI: 10.1016/j.smim.2016.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/15/2016] [Accepted: 05/17/2016] [Indexed: 01/27/2023]
Abstract
Despite substantial opportunity and commercial interest in developing drugs that modulate the complement system in a broad range of non-orphan indications, several obstacles remain to be overcome. Among these issues is the biophysical nature of complement proteins, whose circulating levels are typically very high and whose turnover rates are relatively rapid, especially in the setting of chronic inflammatory conditions. This situation necessitates the use of very high levels of therapeutic compounds in order to achieve both multi-pathway and multiple effector mechanism inhibition. In addition, one must avoid infectious complications or the systemic impairment of the other important physiological functions of complement. Herein we focus on the development of a novel therapeutic strategy based on injured tissue-specific targeting of complement inhibitors using the antigen-combining domains of a small subset of natural IgM antibodies, which as endogenous antibodies specifically recognize sites of local damage across a broad range of tissues and locally activate complement C3, resulting in C3 fragment covalent fixation. Because the use of such recombinant tissue-targeting inhibitors precludes the utility of measuring systemic levels of complement biomarkers or function, since a goal of this targeting strategy is to leave those processes intact and unimpeded, we also briefly describe a new method designed to quantitatively measure using imaging modalities the inhibition of generation of fixed C3 fragments at sites of inflammation/injury. In addition to the ability to determine whether complement activation is locally constrained with the use of inhibitors, there is also a broader application of this imaging approach to inflammatory and autoimmune diseases characterized by local complement activation.
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Affiliation(s)
- V Michael Holers
- Departments of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO, United States.
| | - Stephen Tomlinson
- Research Service, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, United States; Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, United States
| | - Liudmila Kulik
- Departments of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Carl Atkinson
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, United States; Department of Surgery, Transplant Immunobiology Laboratory, Medical University of South Carolina, Charleston, SC, United States
| | - Bärbel Rohrer
- Research Service, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, United States; Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, United States
| | - Nirmal Banda
- Departments of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Joshua M Thurman
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
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102
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Shaw PX, Stiles T, Douglas C, Ho D, Fan W, Du H, Xiao X. Oxidative stress, innate immunity, and age-related macular degeneration. AIMS MOLECULAR SCIENCE 2016; 3:196-221. [PMID: 27239555 PMCID: PMC4882104 DOI: 10.3934/molsci.2016.2.196] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of vision loss affecting tens of millions of elderly worldwide. Early AMD is characterized by the appearance of soft drusen, as well as pigmentary changes in the retinal pigment epithelium (RPE). These soft, confluent drusen can progress into two forms of advanced AMD: geographic atrophy (GA, or dry AMD) or choroidal neovascularization (CNV, or wet AMD). Both forms of AMD result in a similar clinical progression in terms of loss of central vision. The exact mechanism for developing early AMD, as well as triggers responsible for progressing to advanced stage of disease, is still largely unknown. However, significant evidence exists demonstrating a complex interplay of genetic and environmental factors as causes of AMD progression. Multiple genes and/or single nucleotide polymorphisms (SNPs) have been found associated with AMD, including various genes involved in the complement pathway, lipid metabolism and extracellular matrix (ECM) remodeling. Of the known genetic contributors to disease risk, the CFH Y402H and HTRA1/ARMS polymorphisms contribute to more than 50% of the genetic risk for AMD. Environmentally, oxidative stress plays a critical role in many aging diseases including cardiovascular disease, cancer, Alzheimer’s disease and AMD. Due to the exposure to sunlight and high oxygen concentration, the oxidative stress burden is higher in the eye than other tissues, which can be further complicated by additional oxidative stressors such as smoking. Increasingly, evidence is accumulating suggesting that functional abnormalities of the innate immune system incurred via high risk genotypes may be contributing to the pathogenesis of AMD by altering the inflammatory homeostasis in the eye, specifically in the handling of oxidation products. As the eye in non-pathological instances maintains a low level of inflammation despite the presence of a relative abundance of potentially inflammatory molecules, we have previously hypothesized that the tight homeostatic control of inflammation via the innate immune system is likely critical for avoidance of disease progression. However, the presence of a multitude of potential triggers of inflammation results in a sensitive balance in which perturbations thereof would subsequently alter the inflammatory state of the retina, leading to a state of chronic inflammation and pathologic progression. In this review, we will highlight the background literature surrounding the known genetic and environmental contributors to AMD risk, as well as a discussion of the potential mechanistic interplay of these factors that lead to disease pathogenesis with particular emphasis on the delicate control of inflammatory homeostasis and the centrality of the innate immune system in this process.
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Affiliation(s)
- Peter X Shaw
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Travis Stiles
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Christopher Douglas
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Daisy Ho
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Wei Fan
- Huaxi Hospital, Sichuan University, China
| | | | - Xu Xiao
- Sichuan People's Hospital, Chengdu, Sichuan, China
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103
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Distinct roles for the complement regulators factor H and Crry in protection of the kidney from injury. Kidney Int 2016; 90:109-22. [PMID: 27165610 DOI: 10.1016/j.kint.2016.02.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 12/29/2022]
Abstract
Mutations in the complement regulatory proteins are associated with several different diseases. Although these mutations cause dysregulated alternative pathway activation throughout the body, the kidneys are the most common site of injury. The susceptibility of the kidney to alternative pathway-mediated injury may be due to limited expression of complement regulatory proteins on several tissue surfaces within the kidney. To examine the roles of the complement regulatory proteins factor H and Crry in protecting distinct renal surfaces from alternative pathway mediated injury, we generated mice with targeted deletions of the genes for both proteins. Surprisingly, mice with combined genetic deletions of factor H and Crry developed significantly milder renal injury than mice deficient in only factor H. Deficiency of both factor H and Crry was associated with C3 deposition at multiple locations within the kidney, but glomerular C3 deposition was lower than that in factor H alone deficient mice. Thus, factor H and Crry are critical for regulating complement activation at distinct anatomic sites within the kidney. However, widespread activation of the alternative pathway reduces injury by depleting the pool of C3 available at any 1 location.
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104
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Keir LS, Langman CB. Complement and the kidney in the setting of Shiga-toxin hemolytic uremic syndrome, organ transplantation, and C3 glomerulonephritis. Transfus Apher Sci 2016; 54:203-11. [PMID: 27156109 DOI: 10.1016/j.transci.2016.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To review the role of complement in glomerular pathologies focusing on thrombotic microangiopathies (TMA) caused by Shiga toxin (Stx) and organ transplantation associated hemolytic uremic syndrome (HUS) as well as C3 glomerulopathy (C3G). METHODS Examination of literature discussing TMA associated with Stx HUS, transplantation related HUS and C3G. RESULTS There is an emerging role for complement biology in the renal glomerulus where its inappropriate over-activation is integral to several diseases. Stx HUS patients show evidence of complement activation and the toxin itself can activate complement and inhibit its normal regulation. However, therapeutic complement blockade has not yet proven effective in all circumstances. This may be partly related to late use and a clinical trial could be warranted. Organ transplantation associated HUS has carried a poor prognosis. While case reports supporting the use of complement inhibition exist, there has not been a formal trial. Complement activation in C3G is established but again treatment with complement inhibition has failed to be uniformly beneficial. Here, too, a clinical trial may help determine which subgroup of patients should be treated with these agents. CONCLUSION Complement plays an important role in the glomerulus but more work is needed to fully understand how it contributes to normal function and pathology. This will help direct appropriate therapy in these diseases.
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Affiliation(s)
- Lindsay S Keir
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Division of Kidney Diseases, The Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Craig B Langman
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Division of Kidney Diseases, The Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, IL, USA.
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105
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Wong L, Moran S, Lavin PJ, Dorman AM, Conlon PJ. Kidney transplant outcomes in familial C3 glomerulopathy. Clin Kidney J 2016; 9:403-7. [PMID: 27274824 PMCID: PMC4886915 DOI: 10.1093/ckj/sfw020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 02/29/2016] [Indexed: 12/12/2022] Open
Abstract
C3 glomerulopathy, a newly designated entity, is characterized by glomerular disease associated with dysregulation of the alternative complement pathway and is a rare cause of end-stage kidney disease. Overall disease characteristics that include clinical presentation, laboratory assessment, histopathology and genetic background have only been unravelled in recent years and have led to the development of anti-complement therapies targeting different levels of the alternative pathway. We describe the long-term outcomes following kidney transplantation in an Irish family with familial C3 glomerulopathy due to a hybrid CFHR3-1 gene.
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Affiliation(s)
- Limy Wong
- Department of Nephrology , Beaumont Hospital , Dublin , Ireland
| | - Sarah Moran
- Department of Nephrology , Beaumont Hospital , Dublin , Ireland
| | - Peter J Lavin
- Department of Nephrology , Tallaght Hospital , Dublin , Ireland
| | - Anthony M Dorman
- Department of Renal Pathology, Beaumont Hospital, Dublin, Ireland; Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Peter J Conlon
- Department of Nephrology, Beaumont Hospital, Dublin, Ireland; Royal College of Surgeons in Ireland, Dublin, Ireland
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106
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Pouw RB, Brouwer MC, Geissler J, van Herpen LV, Zeerleder SS, Wuillemin WA, Wouters D, Kuijpers TW. Complement Factor H-Related Protein 3 Serum Levels Are Low Compared to Factor H and Mainly Determined by Gene Copy Number Variation in CFHR3. PLoS One 2016; 11:e0152164. [PMID: 27007437 PMCID: PMC4805260 DOI: 10.1371/journal.pone.0152164] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 03/09/2016] [Indexed: 11/19/2022] Open
Abstract
The major human complement regulator in blood, complement factor H (FH), has several closely related proteins, called FH-related (FHR) proteins. As all FHRs lack relevant complement regulatory activity, their physiological role is not well understood. FHR protein 3 (FHR-3) has been suggested to compete with FH for binding to Neisseria meningitidis, thereby affecting complement-mediated clearance. Clearly, the in vivo outcome of such competition greatly depends on the FH and FHR-3 concentrations. While FH levels have been established, accurate FHR-3 levels were never unequivocally reported to date. Moreover, CFHR3 gene copy numbers commonly vary, which may impact the FHR-3 concentration. Hence, we generated five anti-FHR-3 mAbs to specifically measure FHR-3 in human healthy donors of which we determined the gene copy number variation at the CFH/CFHR locus. Finally, we examined the acute-phase response characteristics of FHR-3 in a small sepsis cohort. We determined FHR-3 levels to have a mean of 19 nM and that under normal conditions the copy number of CFHR3 correlates to a very large extent with the FHR-3 serum levels. On average, FHR-3 was 132-fold lower compared to the FH concentration in the same serum samples and FHR-3 did not behave as a major acute phase response protein.
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Affiliation(s)
- Richard B. Pouw
- Department of Immunopathology, Sanquin Research and Landsteiner laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children’s Hospital, Academic Medical Center, Amsterdam, the Netherlands
| | - Mieke C. Brouwer
- Department of Immunopathology, Sanquin Research and Landsteiner laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Judy Geissler
- Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Laurens V. van Herpen
- Department of Immunopathology, Sanquin Research and Landsteiner laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Sacha S. Zeerleder
- Department of Hematology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Walter A. Wuillemin
- Division of Hematology and Central Hematology Laboratory, Luzerner Kantonsspital and University of Berne, Berne, Switzerland
| | - Diana Wouters
- Department of Immunopathology, Sanquin Research and Landsteiner laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- * E-mail:
| | - Taco W. Kuijpers
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children’s Hospital, Academic Medical Center, Amsterdam, the Netherlands
- Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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107
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Xie J, Kiryluk K, Li Y, Mladkova N, Zhu L, Hou P, Ren H, Wang W, Zhang H, Chen N, Gharavi AG. Fine Mapping Implicates a Deletion of CFHR1 and CFHR3 in Protection from IgA Nephropathy in Han Chinese. J Am Soc Nephrol 2016; 27:3187-3194. [PMID: 26940089 DOI: 10.1681/asn.2015111210] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 01/16/2016] [Indexed: 01/30/2023] Open
Abstract
An intronic variant at the complement factor H (CFH) gene on chromosome 1q32 (rs6677604) associates with risk of IgA nephropathy (IgAN), but the association signal has not been uniformly replicated in Han Chinese populations. We investigated whether the causal sequence variant resides in the CFH gene or the neighboring complement factor H-related 1 (CFHR1) gene and CFHR3, which harbor an 84-kb combined deletion (CFHR3,1Δ) in linkage disequilibrium with rs6677604. Imputation of 1000 Genomes Project data did not suggest new causal single-nucleotide variants within the CFH cluster. We next performed copy number analysis across the CFH locus in two independent Han Chinese case-control cohorts (combined n=3581). The CFHR3,1Δ and rs6677604-A alleles were rare (4.4% in patients and 7.1% in controls) and in strong linkage disequilibrium with each other (r2=0.95); of these alleles, CFHR3,1Δ associated more significantly with decreased risk of IgAN (odds ratio [OR], 0.56; 95% confidence interval [95% CI], 0.46 to 0.70; P=8.5 × 10-8 versus OR, 0.61; 95% CI, 0.50 to 0.75; P=1.6 × 10-6 for rs6677604-A). Moreover, CFHR3,1Δ explained all of the association signal at rs6677604 and remained significant after conditioning on rs6677604 genotype (P=0.01). Exploratory analyses of clinical and histopathologic parameters using the Oxford classification criteria revealed a suggestive association of CFHR3,1Δ with reduced tubulointerstitial injury (OR, 0.46; 95% CI, 0.25 to 0.79). These data indicate that dysregulated activity of the alternative complement pathway contributes to IgAN pathogenesis in both Asians and Europeans and implicate CFHR3,1Δ as the functional allele at this locus.
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Affiliation(s)
- Jingyuan Xie
- Institute of Nephrology, Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Krzysztof Kiryluk
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Yifu Li
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Nikol Mladkova
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Li Zhu
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China
| | - Ping Hou
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China
| | - Hong Ren
- Institute of Nephrology, Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weiming Wang
- Institute of Nephrology, Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Zhang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China
| | - Nan Chen
- Institute of Nephrology, Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ali G Gharavi
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, New York; and
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108
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Muff-Luett M, Nester CM. The Genetics of Ultra-Rare Renal Disease. J Pediatr Genet 2016; 5:33-42. [PMID: 27617140 DOI: 10.1055/s-0036-1572515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/02/2015] [Indexed: 12/14/2022]
Abstract
The complement-mediated renal diseases are a group of ultra-rare renal diseases that disproportionately affect children and young adults and frequently lead to irreversible renal failure. Genetic mutations in alternate pathway of complement genes are pathomechanistically involved in a significant number of these unique diseases. Here, we review our current understanding of the role of genetics in the primary complement-mediated renal diseases affecting children, with a focus on atypical hemolytic uremic syndrome and C3 glomerulopathy. Also, included is a brief discussion of the related diseases whose relationship to complement abnormality has been suspected but not yet confirmed. Advances in genetics have transformed both treatment and outcomes in these historically difficult to treat, highly morbid diseases.
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Affiliation(s)
- Melissa Muff-Luett
- Division of Pediatric Nephrology, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Carla M Nester
- Division of Pediatric Nephrology, Dialysis and Transplantation, Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States; Molecular Otolaryngology and Renal Research Laboratory, University of Iowa, Iowa City, Iowa, United States
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109
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Zhai YL, Meng SJ, Zhu L, Shi SF, Wang SX, Liu LJ, Lv JC, Yu F, Zhao MH, Zhang H. Rare Variants in the Complement Factor H-Related Protein 5 Gene Contribute to Genetic Susceptibility to IgA Nephropathy. J Am Soc Nephrol 2016; 27:2894-905. [PMID: 26825529 DOI: 10.1681/asn.2015010012] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 12/20/2015] [Indexed: 11/03/2022] Open
Abstract
A recent genome-wide association study of IgA nephropathy (IgAN) identified 1q32, which contains multiple complement regulatory genes, including the complement factor H (CFH) gene and the complement factor H-related (CFHRs) genes, as an IgAN susceptibility locus. Abnormal complement activation caused by a mutation in CFHR5 was shown to cause CFHR5 nephropathy, which shares many characteristics with IgAN. To explore the genetic effect of variants in CFHR5 on IgAN susceptibility, we recruited 500 patients with IgAN and 576 healthy controls for genetic analysis. We sequenced all exons and their intronic flanking regions as well as the untranslated regions of CFHR5 and compared the frequencies of identified variants using the sequence kernel association test. We identified 32 variants in CFHR5, including 28 rare and four common variants. The distribution of rare variants in CFHR5 in patients with IgAN differed significantly from that in controls (P=0.002). Among the rare variants, in silico programs predicted nine as potential functional variants, which we then assessed in functional assays. Compared with wild-type CFHR5, three recombinant CFHR5 proteins, CFHR5-M (c.508G>A/p.Val170Met), CFHR5-S (c.533A>G/p.Asn178Ser), and CFHR5-D (c.822A>T/p.Glu274Asp), showed significantly higher C3b binding capacity (CFHR5-M: 109.67%±3.54%; P=0.02; CFHR5-S: 174.27%±9.78%; P<0.001; CFHR5-D: 127.25%±1.75%; P<0.001), whereas another recombinant CFHR5 (c.776T>A/p.Leu259Termination) showed less C3b binding (56.89%±0.57%; P<0.001). Our study found that rare variants in CFHR5 may contribute to the genetic susceptibility to IgAN, which suggests that CFHR5 is an IgAN susceptibility gene.
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Affiliation(s)
- Ya-Ling Zhai
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Si-Jun Meng
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Li Zhu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Su-Fang Shi
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Su-Xia Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Li-Jun Liu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ji-Cheng Lv
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Feng Yu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ming-Hui Zhao
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
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110
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Renner B, Tong HH, Laskowski J, Jonscher K, Goetz L, Woolaver R, Hannan J, Li YX, Hourcade D, Pickering MC, Holers VM, Thurman JM. Annexin A2 Enhances Complement Activation by Inhibiting Factor H. THE JOURNAL OF IMMUNOLOGY 2016; 196:1355-65. [PMID: 26729803 DOI: 10.4049/jimmunol.1500793] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 11/27/2015] [Indexed: 12/31/2022]
Abstract
Factor H is a circulating protein that regulates activation of the alternative pathway (AP) of complement. Mutations and genetic variations of factor H are associated with several AP-mediated diseases, highlighting the critical role of factor H in AP regulation. AP-mediated inflammation is typically triggered by illness or tissue injury, however, and tissue injury can trigger AP activation in individuals with fully functional factor H. This suggests that factor H function is affected by local conditions within tissues. We hypothesized that inducible proteins impair the ability of factor H to locally control the AP, thereby increasing AP activation. We used purified murine factor H to immunoprecipitate binding partners from mouse kidneys. Using immunoaffinity liquid chromatography-mass spectrometry, we identified annexin A2 as a factor H binding partner. Further experiments showed that annexin A2 reduces the binding of factor H to cell surfaces. Recombinant annexin A2 impaired complement regulation by factor H and increased complement activation on renal cell surfaces in vitro and in vivo. In a murine model of acute pneumococcal otitis media, the administration of annexin A2 increased AP-mediated bacterial opsonization and clearance. In conclusion, the local production of annexin A2 within tissues suppresses regulation of the AP by factor H. Annexin A2 can contribute to AP-mediated tissue inflammation by locally impairing factor H function, but it can also improve complement-mediated bacterial clearance.
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Affiliation(s)
- Brandon Renner
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Hua Hua Tong
- Department of Otolaryngology, College of Medicine and Public Health, The Ohio State University, Columbus, OH 43210
| | - Jennifer Laskowski
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Karen Jonscher
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Lindsey Goetz
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Rachel Woolaver
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Jonathan Hannan
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Yong Xing Li
- Department of Otolaryngology, College of Medicine and Public Health, The Ohio State University, Columbus, OH 43210
| | - Dennis Hourcade
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110; and
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, South Kensington Campus, Imperial College, London SW7 2AZ, United Kingdom
| | - V Michael Holers
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Joshua M Thurman
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
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111
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Mészáros T, Csincsi ÁI, Uzonyi B, Hebecker M, Fülöp TG, Erdei A, Szebeni J, Józsi M. Factor H inhibits complement activation induced by liposomal and micellar drugs and the therapeutic antibody rituximab in vitro. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 12:1023-1031. [PMID: 26733258 DOI: 10.1016/j.nano.2015.11.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/16/2015] [Accepted: 11/24/2015] [Indexed: 01/08/2023]
Abstract
UNLABELLED Hypersensitivity reactions to particulate drugs can partly be caused by complement activation and represent a major complication during intravenous application of nanomedicines. Several liposomal and micellar drugs and carriers, and therapeutic antibodies, were shown to activate complement and induce complement activation-related pseudoallergy (CARPA) in model animals. To explore the possible use of the natural complement inhibitor factor H (FH) against CARPA, we examined the effect of FH on complement activation induced by CARPAgenic drugs. Exogenous FH inhibited complement activation induced by the antifungal liposomal Amphotericin-B (AmBisome), the widely used solvent of anticancer drugs Cremophor EL, and the anticancer monoclonal antibody rituximab in vitro. An engineered form of FH (mini-FH) was more potent inhibitor of Ambisome-, Cremophor EL- and rituximab-induced complement activation than FH. The FH-related protein CFHR1 had no inhibitory effect. Our data suggest that FH or its derivatives may be considered in the pharmacological prevention of CARPA. FROM THE CLINICAL EDITOR Although liposomes and micelles are already in use in the clinical setting as drug carriers, there remains the potential problem of hypersensitivity due to complement activation. In this article, the authors investigated the use of complement inhibitor factor H (FH) on complement activation and showed good efficacy. The results would therefore suggest the potential application of complement inhibitor in the future.
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Affiliation(s)
- Tamás Mészáros
- Nanomedicine Research and Education Center, Semmelweis University, Budapest, Hungary; SeroScience Ltd., Budapest, Hungary
| | - Ádám I Csincsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Barbara Uzonyi
- MTA-ELTE Immunology Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Mario Hebecker
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Tamás G Fülöp
- Nanomedicine Research and Education Center, Semmelweis University, Budapest, Hungary; SeroScience Ltd., Budapest, Hungary
| | - Anna Erdei
- MTA-ELTE Immunology Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary; Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - János Szebeni
- Nanomedicine Research and Education Center, Semmelweis University, Budapest, Hungary; SeroScience Ltd., Budapest, Hungary
| | - Mihály Józsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary.
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112
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Harder MJ, Anliker M, Höchsmann B, Simmet T, Huber-Lang M, Schrezenmeier H, Ricklin D, Lambris JD, Barlow PN, Schmidt CQ. Comparative Analysis of Novel Complement-Targeted Inhibitors, MiniFH, and the Natural Regulators Factor H and Factor H-like Protein 1 Reveal Functional Determinants of Complement Regulation. THE JOURNAL OF IMMUNOLOGY 2015; 196:866-76. [PMID: 26643478 DOI: 10.4049/jimmunol.1501919] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/04/2015] [Indexed: 01/08/2023]
Abstract
The serum proteins factor H (FH), consisting of 20 complement control protein modules (CCPs), and its splice product FH-like protein 1 (FHL-1; consisting of CCPs 1-7) are major regulators of the alternative pathway (AP) of complement activation. The engineered version of FH, miniFH, contains only the N- and C-terminal portions of FH linked by an optimized peptide and shows ∼ 10-fold higher ex vivo potency. We explored the hypothesis that regulatory potency is enhanced by unmasking of a ligand-binding site in the C-terminal CCPs 19-20 that is cryptic in full-length native FH. Therefore, we produced an FH variant lacking the central domains 10-15 (FHΔ10-15). To explore how avidity affects regulatory strength, we generated a duplicated version of miniFH, termed midiFH. We compared activities of FHΔ10-15 and midiFH to miniFH, FH, and FHL-1. Relative to FH, FHΔ10-15 exhibited an altered binding profile toward C3 activation products and a 5-fold-enhanced complement regulation on a paroxysmal nocturnal hemoglobinuria patient's erythrocytes. Contrary to dogma, FHL-1 and FH exhibited equal regulatory activity, suggesting that the role of FHL-1 in AP regulation has been underestimated. Unexpectedly, a substantially increased avidity for complement opsonins, as seen in midiFH, did not potentiate the inhibitory potential on host cells. In conclusion, comparisons of engineered and native FH-based regulators have identified features that determine high AP regulatory activity on host cells. Unrestricted availability of FH CCPs 19-20 and an optimal spatial orientation between the N- and C-terminal FH regions are key.
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Affiliation(s)
- Markus J Harder
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, 89081 Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Service Baden-Württemberg - Hessen and University Hospital Ulm, 89081 Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, 89081 Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Service Baden-Württemberg - Hessen and University Hospital Ulm, 89081 Ulm, Germany
| | - Thomas Simmet
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany
| | - Markus Huber-Lang
- Department of Traumatology, Center of Surgery, University of Ulm, 89081 Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, 89081 Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Service Baden-Württemberg - Hessen and University Hospital Ulm, 89081 Ulm, Germany
| | - Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - Paul N Barlow
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom; and School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany;
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113
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Magistroni R, D’Agati VD, Appel GB, Kiryluk K. New developments in the genetics, pathogenesis, and therapy of IgA nephropathy. Kidney Int 2015; 88:974-89. [PMID: 26376134 PMCID: PMC4653078 DOI: 10.1038/ki.2015.252] [Citation(s) in RCA: 173] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/11/2015] [Accepted: 05/20/2015] [Indexed: 02/07/2023]
Abstract
Recent years have brought notable progress in the field of IgA nephropathy. Here, we highlight important new directions and latest developments, including successful discovery of several genetic susceptibility loci, formulation of the multihit pathogenesis model, introduction of the Oxford pathology scoring system, and formalization of the Kidney Disease Improving Global Outcomes (KDIGO) consensus treatment guidelines. We focus on the latest genetic findings that confirm a strong contribution of inherited factors and explain some of the geoethnic disparities in disease susceptibility. Most IgA nephropathy susceptibility loci discovered to date encode genes involved in the maintenance of the intestinal epithelial barrier and response to mucosal pathogens. The concerted pattern of interpopulation allelic differentiation across all genetic loci parallels the disease prevalence and correlates with variation in local pathogens, suggesting that multilocus adaptation might have shaped the present-day landscape of IgA nephropathy. Importantly, the 'Intestinal Immune Network for IgA Production' emerged as one of the new targets for potential therapeutic intervention. We place these findings in the context of the multihit pathogenesis model and existing knowledge of IgA immunobiology. Lastly, we provide our perspective on the existing treatment options, discuss areas of clinical uncertainty, and outline ongoing clinical trials and translational studies.
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Affiliation(s)
- Riccardo Magistroni
- Division of Nephrology, Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, NY, USA
- Division of Nephrology Dialysis and Transplantation, Department of Surgery, Medicine, Dentistry, Morphologic Science, Transplantation, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, Italy
| | - Vivette D. D’Agati
- Division of Renal Pathology, Department of Pathology, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Gerald B. Appel
- Division of Nephrology, Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Krzysztof Kiryluk
- Division of Nephrology, Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, NY, USA
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114
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Chen Q, Manzke M, Hartmann A, Büttner M, Amann K, Pauly D, Wiesener M, Skerka C, Zipfel PF. Complement Factor H-Related 5-Hybrid Proteins Anchor Properdin and Activate Complement at Self-Surfaces. J Am Soc Nephrol 2015; 27:1413-25. [PMID: 26432903 DOI: 10.1681/asn.2015020212] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 08/04/2015] [Indexed: 12/12/2022] Open
Abstract
C3 glomerulopathy (C3G) is a severe kidney disease for which no specific therapy exists. The causes of C3G are heterogeneous, and defective complement regulation is often linked to C3G pathogenesis. Copy number variations in the complement factor H-related (CFHR) gene cluster on chromosome 1q32 and CFHR5 mutant proteins associate with this disease. Here, we identified CFHR5 as a pattern recognition protein that binds to damaged human endothelial cell surfaces and to properdin, the human complement activator. We found the two N-terminal short consensus repeat domains of CFHR5 contact properdin and mediate dimer formation. These properdin-binding segments are duplicated in two mutant CFHR5 proteins, CFHR2-CFHR5Hyb from German patients with C3G and CFHR5Dup from Cypriot patients with C3G. Each of these mutated proteins assembled into large multimeric complexes and, compared to CFHR5, bound damaged human cell surfaces and properdin with greater intensity and exacerbated local complement activation. This enhanced surface binding and properdin recruitment was further evidenced in the mesangia of a transplanted and explanted kidney from a German patient with a CFHR2-CFHR5Hyb protein. Enhanced properdin staining correlated with local complement activation with C3b and C5b-9 deposition on the mesangial cell surface in vitro This gain of function in complement activation for two disease-associated CFHR5 mutants describes a new disease mechanism of C3G, which is relevant for defining appropriate treatment options for this disorder.
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Affiliation(s)
- Qian Chen
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Melanie Manzke
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Andrea Hartmann
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Maike Büttner
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nuremberg, Germany
| | - Kerstin Amann
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nuremberg, Germany
| | - Diana Pauly
- University Hospital Regensburg, Regensburg, Germany; and
| | - Michael Wiesener
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nuremberg, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany; Friedrich Schiller University, Jena, Germany
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115
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Clark SJ, Bishop PN. Role of Factor H and Related Proteins in Regulating Complement Activation in the Macula, and Relevance to Age-Related Macular Degeneration. J Clin Med 2015; 4:18-31. [PMID: 25729613 PMCID: PMC4340553 DOI: 10.3390/jcm4010018] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The recent revolution in age-related macular degeneration (AMD) genetics has demonstrated that genetic alterations affecting the alternative pathway of the complement cascade have a major influence on AMD risk. One of the two most important genetic loci is on chromosome 1 and contains genes encoding complement factor H (FH) and the factor H related proteins (FHR proteins). In macular tissue, especially Bruch’s membrane, relatively high levels of a truncated splice variant of FH called factor H-like protein 1 (FHL-1) are present. Here we discuss how genetic variations may alter the amounts, or by altering their protein sequences, the functions of these proteins. In particular, the common Y402H polymorphism affects the ability of FHL-1 and FH to localize to Bruch’s membrane and the inner choroid because it alters the ability of these complement regulators to bind heparan sulphate (HS) in these structures. In addition, there is an age-related loss of HS from Bruch’s membrane. We hypothesize that a combination of poor binding of the 402H variants of FHL-1 and FH to Bruch’s membrane, combined with a decrease in binding due to age-related HS loss, eventually results in insufficient FHL-1 and FH binding to Bruch’s membrane. This could result in complement activation, inflammation and thereby predispose to AMD.
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Affiliation(s)
- Simon J. Clark
- Centre for Hearing & Vision Research, Institute of Human Development, AV Hill Building, University of Manchester, Oxford Road, Manchester M13 9PL, UK; E-Mail:
- Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Paul N. Bishop
- Centre for Hearing & Vision Research, Institute of Human Development, AV Hill Building, University of Manchester, Oxford Road, Manchester M13 9PL, UK; E-Mail:
- Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
- Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WH, UK
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +44-(0)-161-275-5755
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116
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Abstract
C3 glomerulonephritis is a clinicopathologic entity defined by the presence of isolated or dominant deposits of C3 on immunofluorescence. To explore the effect of immunosuppression on C3 glomerulonephritis, we studied a series of 60 patients in whom a complete registry of treatments was available over a median follow-up of 47 months. Twenty patients had not received immunosuppressive treatments. In the remaining 40 patients, 22 had been treated with corticosteroids plus mycophenolate mofetil while 18 were treated with other immunosuppressive regimens (corticosteroids alone or corticosteroids plus cyclophosphamide). The number of patients developing end-stage renal disease was significantly lower among treated compared with untreated patients (3 vs. 7 patients, respectively). No patient in the corticosteroids plus mycophenolate mofetil group doubled serum creatinine nor developed end-stage renal disease, as compared with 7 (significant) and 3 (not significant), respectively, in patients treated with other immunosuppressive regimens. Renal survival (100, 80, and 72% at 5 years) and the number of patients achieving clinical remission (86, 50, and 25%) were significantly higher in patients treated with corticosteroids plus mycophenolate mofetil as compared with patients treated with other immunosuppressive regimens and untreated patients, respectively. Thus, immunosuppressive treatments, particularly corticosteroids plus mycophenolate mofetil, can be beneficial in C3 glomerulonephritis.
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117
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De Vriese AS, Sethi S, Van Praet J, Nath KA, Fervenza FC. Kidney Disease Caused by Dysregulation of the Complement Alternative Pathway: An Etiologic Approach. J Am Soc Nephrol 2015; 26:2917-29. [PMID: 26185203 DOI: 10.1681/asn.2015020184] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Kidney diseases caused by genetic or acquired dysregulation of the complement alternative pathway (AP) are traditionally classified on the basis of clinical presentation (atypical hemolytic uremic syndrome as thrombotic microangiopathy), biopsy appearance (dense deposit disease and C3 GN), or clinical course (atypical postinfectious GN). Each is characterized by an inappropriate activation of the AP, eventuating in renal damage. The clinical diversity of these disorders highlights important differences in the triggers, the sites and intensity of involvement, and the outcome of the AP dysregulation. Nevertheless, we contend that these diseases should be grouped as disorders of the AP and classified on an etiologic basis. In this review, we define different pathophysiologic categories of AP dysfunction. The precise identification of the underlying abnormality is the key to predict the response to immune suppression, plasma infusion, and complement-inhibitory drugs and the outcome after transplantation. In a patient with presumed dysregulation of the AP, the collaboration of the clinician, the renal pathologist, and the biochemical and genetic laboratory is very much encouraged, because this enables the elucidation of both the underlying pathogenesis and the optimal therapeutic approach.
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Affiliation(s)
- An S De Vriese
- Division of Nephrology, AZ Sint-Jan Brugge-Oostende AV, Brugge, Belgium; and
| | | | - Jens Van Praet
- Division of Nephrology, AZ Sint-Jan Brugge-Oostende AV, Brugge, Belgium; and
| | - Karl A Nath
- Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Fernando C Fervenza
- Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
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118
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Complement factor H, FHR-3 and FHR-1 variants associate in an extended haplotype conferring increased risk of atypical hemolytic uremic syndrome. Mol Immunol 2015; 67:276-86. [PMID: 26163426 DOI: 10.1016/j.molimm.2015.06.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/05/2015] [Accepted: 06/10/2015] [Indexed: 12/31/2022]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a severe thrombotic microangiopathy affecting the renal microvasculature and is associated with complement dysregulation caused by mutations or autoantibodies. Disease penetrance and severity is modulated by inheritance of "risk" polymorphisms in the complement genes MCP, CFH and CFHR1. We describe the prevalence of mutations, the frequency of risk polymorphisms and the occurrence of anti-FH autoantibodies in a Spanish aHUS cohort (n=367). We also report the identification of a polymorphism in CFHR3 (c.721C>T; rs379370) that is associated with increased risk of aHUS (OR=1.78; CI 1.22-2.59; p=0.002), and is most frequently included in an extended risk haplotype spanning the CFH-CFHR3-CFHR1 genes. This extended haplotype integrates polymorphisms in the promoter region of CFH and CFHR3, and is associated with poorer evolution of renal function and decreased FH levels. The CFH-CFHR3-CFHR1 aHUS-risk haplotype seems to be the same as was previously associated with protection against meningococcal infections, suggesting that the genetic variability in this region is limited to a few extended haplotypes, each with opposite effects in various human diseases. These results suggest that the combination of quantitative and qualitative variations in the complement proteins encoded by CFH, CFHR3 and CFHR1 genes is key for the association of these haplotypes with disease.
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119
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Merle NS, Church SE, Fremeaux-Bacchi V, Roumenina LT. Complement System Part I - Molecular Mechanisms of Activation and Regulation. Front Immunol 2015; 6:262. [PMID: 26082779 PMCID: PMC4451739 DOI: 10.3389/fimmu.2015.00262] [Citation(s) in RCA: 1001] [Impact Index Per Article: 111.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/11/2015] [Indexed: 12/12/2022] Open
Abstract
Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here, we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical, and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins, and the membrane-attack-complex. We will also discuss the importance of structure-function relationships using the example of atypical hemolytic uremic syndrome. Lastly, we will discuss the development and benefits of therapies using complement inhibitors.
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Affiliation(s)
- Nicolas S Merle
- UMR_S 1138, Cordeliers Research Center, Complement and Diseases Team, INSERM , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France
| | - Sarah Elizabeth Church
- UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France ; UMR_S 1138, Cordeliers Research Center, Integrative Cancer Immunology Team, INSERM , Paris , France
| | - Veronique Fremeaux-Bacchi
- UMR_S 1138, Cordeliers Research Center, Complement and Diseases Team, INSERM , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France ; Service d'Immunologie Biologique, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges-Pompidou , Paris , France
| | - Lubka T Roumenina
- UMR_S 1138, Cordeliers Research Center, Complement and Diseases Team, INSERM , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France
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120
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Józsi M, Tortajada A, Uzonyi B, Goicoechea de Jorge E, Rodríguez de Córdoba S. Factor H-related proteins determine complement-activating surfaces. Trends Immunol 2015; 36:374-84. [DOI: 10.1016/j.it.2015.04.008] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/15/2015] [Accepted: 04/20/2015] [Indexed: 01/07/2023]
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121
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Merle NS, Noe R, Halbwachs-Mecarelli L, Fremeaux-Bacchi V, Roumenina LT. Complement System Part II: Role in Immunity. Front Immunol 2015; 6:257. [PMID: 26074922 PMCID: PMC4443744 DOI: 10.3389/fimmu.2015.00257] [Citation(s) in RCA: 654] [Impact Index Per Article: 72.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 05/09/2015] [Indexed: 12/14/2022] Open
Abstract
The complement system has been considered for a long time as a simple lytic cascade, aimed to kill bacteria infecting the host organism. Nowadays, this vision has changed and it is well accepted that complement is a complex innate immune surveillance system, playing a key role in host homeostasis, inflammation, and in the defense against pathogens. This review discusses recent advances in the understanding of the role of complement in physiology and pathology. It starts with a description of complement contribution to the normal physiology (homeostasis) of a healthy organism, including the silent clearance of apoptotic cells and maintenance of cell survival. In pathology, complement can be a friend or a foe. It acts as a friend in the defense against pathogens, by inducing opsonization and a direct killing by C5b–9 membrane attack complex and by triggering inflammatory responses with the anaphylatoxins C3a and C5a. Opsonization plays also a major role in the mounting of an adaptive immune response, involving antigen presenting cells, T-, and B-lymphocytes. Nevertheless, it can be also an enemy, when pathogens hijack complement regulators to protect themselves from the immune system. Inadequate complement activation becomes a disease cause, as in atypical hemolytic uremic syndrome, C3 glomerulopathies, and systemic lupus erythematosus. Age-related macular degeneration and cancer will be described as examples showing that complement contributes to a large variety of conditions, far exceeding the classical examples of diseases associated with complement deficiencies. Finally, we discuss complement as a therapeutic target.
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Affiliation(s)
- Nicolas S Merle
- UMRS 1138, Centre de Recherche des Cordeliers, INSERM , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Université Paris 06 , Paris , France
| | - Remi Noe
- UMRS 1138, Centre de Recherche des Cordeliers, INSERM , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Université Paris 06 , Paris , France ; Ecole Pratique des Hautes Études (EPHE) , Paris , France
| | - Lise Halbwachs-Mecarelli
- UMRS 1138, Centre de Recherche des Cordeliers, INSERM , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Université Paris 06 , Paris , France
| | - Veronique Fremeaux-Bacchi
- UMRS 1138, Centre de Recherche des Cordeliers, INSERM , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Université Paris 06 , Paris , France ; Service d'Immunologie Biologique, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges-Pompidou , Paris , France
| | - Lubka T Roumenina
- UMRS 1138, Centre de Recherche des Cordeliers, INSERM , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMRS 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Université Paris 06 , Paris , France
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122
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de Córdoba SR. Complement genetics and susceptibility to inflammatory disease. Lessons from genotype-phenotype correlations. Immunobiology 2015; 221:709-14. [PMID: 26004345 DOI: 10.1016/j.imbio.2015.05.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
Abstract
Different genome-wide linkage and association studies performed during the last 15 years have associated mutations and polymorphisms in complement genes with different diseases characterized by tissue damage and inflammation. These are complex disorders in which genetically susceptible individuals usually develop the pathology as a consequence of environmental triggers. Although complement dysregulation is a common feature of these pathologies, how the disease phenotype is determined is only partly understood. One way to advance understanding is to focus the research in the analysis of the peculiar genotype-phenotype correlations that characterize some of these diseases. I will review here how understanding the functional consequences of these disease-associated complement genetic variants is providing us with novel insights into the underpinning complement biology and a better knowledge of the pathogenic mechanisms underlying each of these pathologies. These advances have important therapeutic and diagnostic implications.
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123
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Targeting mechanisms at sites of complement activation for imaging and therapy. Immunobiology 2015; 221:726-32. [PMID: 25979851 DOI: 10.1016/j.imbio.2015.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 04/20/2015] [Indexed: 01/24/2023]
Abstract
The complement system plays a key role in many acute injury states as well as chronic autoimmune and inflammatory diseases. Localized complement activation and alternative pathway-mediated amplification on diverse target surfaces promote local recruitment of pro-inflammatory cells and elaboration of other mediators. Despite a general understanding of the architecture of the system, though, many of the mechanisms that underlie site-specific complement activation and amplification in vivo are incompletely understood. In addition, there is no capability yet to measure the level of local tissue site-specific complement activation in patients without performing biopsies to detect products using immunohistochemical techniques. Herein is reviewed emerging evidence obtained through clinical research studies of human rheumatoid arthritis along with translational studies of its disease models which demonstrate that several parallel mechanisms are involved in site-specific amplification of activation of the complement system in vivo. Among these processes are de-regulation of the alternative pathway, effector pathway-catalyzed amplification of proximal complement activation, recognition of injury-associated ligands by components of the lectin pathway, and engagement of pathogenic natural antibodies that recognize a limited set of injury-associated neoepitopes. Studies suggest that each of these inter-related processes can play key roles in amplification of complement-dependent injury on self-tissues in vivo. These findings, in addition to development of an imaging strategy described herein designed to quantitatively measure local complement C3 fixation, have relevance to therapeutic and diagnostic strategies targeting the complement system.
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Zipfel PF, Skerka C, Chen Q, Wiech T, Goodship T, Johnson S, Fremeaux-Bacchi V, Nester C, de Córdoba SR, Noris M, Pickering M, Smith R. The role of complement in C3 glomerulopathy. Mol Immunol 2015; 67:21-30. [PMID: 25929733 DOI: 10.1016/j.molimm.2015.03.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 12/12/2022]
Abstract
C3 glomerulopathy describes a spectrum of disorders with glomerular pathology associated with C3 cleavage product deposition and with defective complement action and regulation (Fakhouri et al., 2010; Sethi et al., 2012b). Kidney biopsies from these patients show glomerular accumulation or deposition of C3 cleavage fragments, but no or minor deposition of immunoglobulins (Appel et al., 2005; D'Agati and Bomback, 2012; Servais et al., 2007; Sethi and Fervenza, 2011). At present the current situation asks for a better definition of the underlining disease mechanisms, for precise biomarkers, and for a treatment for this disease. The complement system is a self activating and propelling enzymatic cascade type system in which inactive, soluble plasma components are activated spontaneously and lead into an amplification loop (Zipfel and Skerka, 2009). Activation of the alternative pathway is spontaneous, occurs by default, and cascade progression leads to amplification by complement activators. The system however is self-controlled by multiple regulators and inhibitors, like Factor H that control cascade progression in fluid phase and on surfaces. The activated complement system generates a series of potent effector components and activation products, which damage foreign-, as well as modified self cells, recruit innate immune cells to the site of action, coordinate inflammation and the response of the adaptive immune system in form of B cells and T lymphocytes (Kohl, 2006; Medzhitov and Janeway, 2002; Ogden and Elkon, 2006; Carroll, 2004; Kemper and Atkinson, 2007; Morgan, 1999; Muller-Eberhard, 1986; Ricklin et al., 2010). Complement controls homeostasis and multiple reactions in the vertebrate organism including defense against microbial infections (Diaz-Guillen et al., 1999; Mastellos and Lambris, 2002; Nordahl et al., 2004; Ricklin et al., 2010). In consequence defective control of the spontaneous self amplifying cascade or regulation is associated with numerous human disorders (Ricklin and Lambris, 2007; Skerka and Zipfel, 2008; Zipfel et al., 2006). Understanding the exact action and regulation of this sophisticated homeotic cascade system is relevant to understand disease pathology of various complement associated human disorders. Furthermore this knowledge is relevant for a better diagnosis and appropriate therapy. At present diagnosis of C3 glomerulopathy is primarily based on the kidney biopsy, and histological, immmunohistological and electron microscopical evaluation (D'Agati and Bomback, 2012; Fakhouri et al., 2010; Medjeral-Thomas et al., 2014a,b; Sethi et al., 2012b). The challenge is to define the actual cause of the diverse glomerular changes or damages, to define how C3 deposition results in the reported glomerular changes, the location of the cell damage and the formation of deposits.
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Affiliation(s)
- Peter F Zipfel
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany; Friedrich Schiller University Jena, Germany.
| | - Christine Skerka
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Qian Chen
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Thorsten Wiech
- Institute for Pathology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Goodship
- Institute of Human Genetics, University of Newcastle upon Tyne, United Kingdom
| | - Sally Johnson
- Institute of Human Genetics, University of Newcastle upon Tyne, United Kingdom
| | - Veronique Fremeaux-Bacchi
- Assistance Publique-Hopitaux de Paris, Hospital European Georges-Pompidou and INSERM UMRS 1138, "Complement and Diseases" Team, Cordelier Research Center, Paris, France
| | - Clara Nester
- University of Iowa Carver College of Medicine, Otolaryngology, Iowa City, IA 52242, USA
| | - Santiago Rodríguez de Córdoba
- Departamento de Medicina Celular y Molecular, and Ciber de Enfermedades Raras, Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Marina Noris
- Mario Negri Institute for Pharmacological Research, Ranica, Bergamo, Italy
| | | | - Richard Smith
- University of Iowa Carver College of Medicine, Otolaryngology, Iowa City, IA 52242, USA
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125
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Csincsi ÁI, Kopp A, Zöldi M, Bánlaki Z, Uzonyi B, Hebecker M, Caesar JJE, Pickering MC, Daigo K, Hamakubo T, Lea SM, Goicoechea de Jorge E, Józsi M. Factor H-related protein 5 interacts with pentraxin 3 and the extracellular matrix and modulates complement activation. THE JOURNAL OF IMMUNOLOGY 2015; 194:4963-73. [PMID: 25855355 PMCID: PMC4416742 DOI: 10.4049/jimmunol.1403121] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/11/2015] [Indexed: 01/28/2023]
Abstract
The physiological roles of the factor H (FH)-related proteins are controversial and poorly understood. Based on genetic studies, FH-related protein 5 (CFHR5) is implicated in glomerular diseases, such as atypical hemolytic uremic syndrome, dense deposit disease, and CFHR5 nephropathy. CFHR5 was also identified in glomerular immune deposits at the protein level. For CFHR5, weak complement regulatory activity and competition for C3b binding with the plasma complement inhibitor FH have been reported, but its function remains elusive. In this study, we identify pentraxin 3 (PTX3) as a novel ligand of CFHR5. Binding of native CFHR5 to PTX3 was detected in human plasma and the interaction was characterized using recombinant proteins. The binding of PTX3 to CFHR5 is of ∼2-fold higher affinity compared with that of FH. CFHR5 dose-dependently inhibited FH binding to PTX3 and also to the monomeric, denatured form of the short pentraxin C-reactive protein. Binding of PTX3 to CFHR5 resulted in increased C1q binding. Additionally, CFHR5 bound to extracellular matrix in vitro in a dose-dependent manner and competed with FH for binding. Altogether, CFHR5 reduced FH binding and its cofactor activity on pentraxins and the extracellular matrix, while at the same time allowed for enhanced C1q binding. Furthermore, CFHR5 allowed formation of the alternative pathway C3 convertase and supported complement activation. Thus, CFHR5 may locally enhance complement activation via interference with the complement-inhibiting function of FH, by enhancement of C1q binding, and by activating complement, thereby contributing to glomerular disease.
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Affiliation(s)
- Ádám I Csincsi
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Anne Kopp
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany
| | - Miklós Zöldi
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Zsófia Bánlaki
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Barbara Uzonyi
- Hungarian Academy of Sciences-Eötvös Loránd University Immunology Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Mario Hebecker
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany
| | - Joseph J E Caesar
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RF, United Kingdom
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, United Kingdom; and
| | - Kenji Daigo
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Takao Hamakubo
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RF, United Kingdom
| | - Elena Goicoechea de Jorge
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, United Kingdom; and
| | - Mihály Józsi
- Hungarian Academy of Sciences-Eötvös Loránd University "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, 1117 Budapest, Hungary; Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany;
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126
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Pouw RB, Vredevoogd DW, Kuijpers TW, Wouters D. Of mice and men: The factor H protein family and complement regulation. Mol Immunol 2015; 67:12-20. [PMID: 25824240 DOI: 10.1016/j.molimm.2015.03.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 10/23/2022]
Abstract
For decades immunological research has relied, with variable success, on mouse models to investigate diseases and possible therapeutic interventions. With the approval of the first therapeutic antibody targeting complement, called eculizumab, as therapy in paroxysmal nocturnal hemoglobinuria (PNH) and more recently atypical hemolytic uremic syndrome (aHUS), the viability of targeting the complement system was demonstrated. The potent, endogenous complement regulators have become of increasing interest as templates for designing and developing new therapeutics. Recently, complement inhibitors based on (parts of) the human complement regulator factor H (FH) are being examined for therapeutic intervention in inflammatory conditions. The first step to evaluate the potency of a new drug is often testing it in a mouse model for the target disease. However, translating results to human conditions requires a good understanding of similarities and, more importantly, differences between the human and mouse complement system and particularly regulation. This review will provide a comprehensive overview of the complement regulator FH and its closely related proteins and current views on their role in mice and men.
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Affiliation(s)
- R B Pouw
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands; Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, the Netherlands.
| | - D W Vredevoogd
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - T W Kuijpers
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, the Netherlands; Department of Blood Cell Research, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - D Wouters
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
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127
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Maillard N, Wyatt RJ, Julian BA, Kiryluk K, Gharavi A, Fremeaux-Bacchi V, Novak J. Current Understanding of the Role of Complement in IgA Nephropathy. J Am Soc Nephrol 2015; 26:1503-12. [PMID: 25694468 DOI: 10.1681/asn.2014101000] [Citation(s) in RCA: 212] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Complement activation has a role in the pathogenesis of IgA nephropathy, an autoimmune disease mediated by pathogenic immune complexes consisting of galactose-deficient IgA1 bound by antiglycan antibodies. Of three complement-activation pathways, the alternative and lectin pathways are involved in IgA nephropathy. IgA1 can activate both pathways in vitro, and pathway components are present in the mesangial immunodeposits, including properdin and factor H in the alternative pathway and mannan-binding lectin, mannan-binding lectin-associated serine proteases 1 and 2, and C4d in the lectin pathway. Genome-wide association studies identified deletion of complement factor H-related genes 1 and 3 as protective against the disease. Because the corresponding gene products compete with factor H in the regulation of the alternative pathway, it has been hypothesized that the absence of these genes could lead to more potent inhibition of complement by factor H. Complement activation can take place directly on IgA1-containing immune complexes in circulation and/or after their deposition in the mesangium. Notably, complement factors and their fragments may serve as biomarkers of IgA nephropathy in serum, urine, or renal tissue. A better understanding of the role of complement in IgA nephropathy may provide potential targets and rationale for development of complement-targeting therapy of the disease.
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Affiliation(s)
- Nicolas Maillard
- University of Alabama at Birmingham, Departments of Microbiology and Medicine, Birmingham, Alabama; Université Jean Monnet, Groupe sur l'immunité des Muqueuses et Agents Pathogènes, St. Etienne, Pôle de Recherche et d'Enseignement Supérieur, Université de Lyon, Lyon, France
| | - Robert J Wyatt
- University of Tennessee Health Science Center and Children's Foundation Research at the Le Bonheur Children's Hospital, Memphis, Tennessee
| | - Bruce A Julian
- University of Alabama at Birmingham, Departments of Microbiology and Medicine, Birmingham, Alabama
| | - Krzysztof Kiryluk
- Columbia University, Department of Medicine, New York, New York; and
| | - Ali Gharavi
- Columbia University, Department of Medicine, New York, New York; and
| | - Veronique Fremeaux-Bacchi
- Unité Mixte de Recherche en Santé 1138, Team "Complement and Diseases," Cordeliers Research Center, Paris, France
| | - Jan Novak
- University of Alabama at Birmingham, Departments of Microbiology and Medicine, Birmingham, Alabama;
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128
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Abstract
'Membranoproliferative' describes glomerular injury characterized by capillary wall thickening and mesangial expansion owing to increased matrix deposition and hypercellularity. The presence of immune deposits is indicative of membranoproliferative glomerulonephritis (MPGN). Historically, MPGN was further classified into three types according to the appearance and site of the electron-dense deposits seen by electron microscopy, but it is now recognized that many cases show only deposition of the complement component C3, owing to abnormal control of the alternative pathway of complement activation-these cases are now classified as C3 glomerulopathies. Not all cases of C3 glomerulopathy, however, show an MPGN pattern. C3 glomerulopathies include dense deposit disease, which shows dense osmiophilic deposits, and C3 glomerulonephritis, which shows isolated deposits. In many cases, the genetic mutations or autoantibodies responsible for C3 deposition have been identified. Some patients in whom complement control is abnormal will accumulate small amounts of immunoglobulin in their glomeruli and so, in everyday practice, the morphological diagnosis of 'glomerulonephritis with dominant C3' is useful for identifying patients who require investigation of the complement pathway. The recognition that many cases of MPGN are C3 glomerulopathies and that the underlying cause can often be identified in immunoglobulin-associated cases means that the diagnosis of idiopathic MPGN is now very uncommon.
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Affiliation(s)
- H Terence Cook
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, UK
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, UK
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Clark SJ, Schmidt CQ, White AM, Hakobyan S, Morgan BP, Bishop PN. Identification of factor H-like protein 1 as the predominant complement regulator in Bruch's membrane: implications for age-related macular degeneration. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 193:4962-70. [PMID: 25305316 PMCID: PMC4225158 DOI: 10.4049/jimmunol.1401613] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The tight regulation of innate immunity on extracellular matrix (ECM) is a vital part of immune homeostasis throughout the human body, and disruption to this regulation in the eye is thought to contribute directly to the progression of age-related macular degeneration (AMD). The plasma complement regulator factor H (FH) is thought to be the main regulator that protects ECM against damaging complement activation. However, in the present study we demonstrate that a truncated form of FH, called FH-like protein 1 (FHL-1), is the main regulatory protein in the layer of ECM under human retina, called Bruch's membrane. Bruch's membrane is a major site of AMD disease pathogenesis and where drusen, the hallmark lesions of AMD, form. We show that FHL-1 can passively diffuse through Bruch's membrane, whereas the full sized, glycosylated, FH cannot. FHL-1 is largely bound to Bruch's membrane through interactions with heparan sulfate, and we show that the common Y402H polymorphism in the CFH gene, associated with an increased risk of AMD, reduces the binding of FHL-1 to this heparan sulfate. We also show that FHL-1 is retained in drusen whereas FH coats the periphery of the lesions, perhaps inhibiting their clearance. Our results identify a novel mechanism of complement regulation in the human eye, which highlights potential new avenues for therapeutic strategies.
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Affiliation(s)
- Simon J Clark
- Centre for Hearing and Vision Research, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom;
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany
| | - Anne M White
- Centre for Hearing and Vision Research, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom
| | - Svetlana Hakobyan
- Complement Biology Group, Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom; and
| | - B Paul Morgan
- Complement Biology Group, Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom; and
| | - Paul N Bishop
- Centre for Hearing and Vision Research, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom; Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, United Kingdom
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130
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Zhang Y, Nester CM, Martin B, Skjoedt MO, Meyer NC, Shao D, Borsa N, Palarasah Y, Smith RJH. Defining the complement biomarker profile of C3 glomerulopathy. Clin J Am Soc Nephrol 2014; 9:1876-82. [PMID: 25341722 DOI: 10.2215/cjn.01820214] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND OBJECTIVES C3 glomerulopathy (C3G) applies to a group of renal diseases defined by a specific renal biopsy finding: a dominant pattern of C3 fragment deposition on immunofluorescence. The primary pathogenic mechanism involves abnormal control of the alternative complement pathway, although a full description of the disease spectrum remains to be determined. This study sought to validate and define the association of complement dysregulation with C3G and to determine whether specific complement pathway abnormalities could inform disease definition. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study included 34 patients with C3G (17 with C3 glomerulonephritis [C3GN] and 17 with dense deposit disease [DDD]) diagnosed between 2008 and 2013 selected from the C3G Registry. Control samples (n=100) were recruited from regional blood drives. Nineteen complement biomarkers were assayed on all samples. Results were compared between C3G disease categories and with normal controls. RESULTS Assessment of the alternative complement pathway showed that compared with controls, patients with C3G had lower levels of serum C3 (P<0.001 for both DDD and C3GN) and factor B (P<0.001 for both DDD and C3GN) as well as higher levels of complement breakdown products including C3d (P<0.001 for both DDD and C3GN) and Bb (P<0.001 for both DDD and C3GN). A comparison of terminal complement pathway proteins showed that although C5 levels were significantly suppressed (P<0.001 for both DDD and C3GN) its breakdown product C5a was significantly higher only in patients with C3GN (P<0.05). Of the other terminal pathway components (C6-C9), the only significant difference was in C7 levels between patients with C3GN and controls (P<0.01). Soluble C5b-9 was elevated in both diseases but only the difference between patients with C3GN and controls reached statistical significance (P<0.001). Levels of C3 nephritic factor activity were qualitatively higher in patients with DDD compared with patients with C3GN. CONCLUSIONS Complement biomarkers are significantly abnormal in patients with C3G compared with controls. These data substantiate the link between complement dysregulation and C3G and identify C3G interdisease differences.
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Affiliation(s)
- Yuzhou Zhang
- Molecular Otolaryngology and Renal Research Laboratories
| | - Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, Division of Nephrology, Department of Internal Medicine, Division of Nephrology, Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Bertha Martin
- Molecular Otolaryngology and Renal Research Laboratories, Department of Anatomy and Cell Biology, Graduate Program, and
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health Sciences, University Hospital of Copenhagen, Copenhagen, Denmark; and
| | - Nicole C Meyer
- Molecular Otolaryngology and Renal Research Laboratories
| | - Dingwu Shao
- Molecular Otolaryngology and Renal Research Laboratories
| | - Nicolò Borsa
- Molecular Otolaryngology and Renal Research Laboratories
| | - Yaseelan Palarasah
- Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Division of Nephrology, Department of Internal Medicine, Division of Nephrology, Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa;
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131
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Barbour TD, Ruseva MM, Pickering MC. Update on C3 glomerulopathy. Nephrol Dial Transplant 2014; 31:717-25. [PMID: 25326473 PMCID: PMC4848753 DOI: 10.1093/ndt/gfu317] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 09/10/2014] [Indexed: 02/06/2023] Open
Abstract
C3 glomerulopathy refers to a disease process in which abnormal control of complement activation, degradation or deposition results in predominant C3 fragment deposition within the glomerulus and glomerular damage. Recent studies have improved our understanding of its pathogenesis. The key abnormality is uncontrolled C3b amplification in the circulation and/or along the glomerular basement membrane. Family studies in which disease segregates with structurally abnormal complement factor H-related (CFHR) proteins demonstrate that abnormal CFHR proteins are important in some types of C3 glomerulopathy. This is currently thought to be due to the ability of these proteins to antagonize the major negative regulator of C3 activation, complement factor H (CFH), a process termed ‘CFH de-regulation’. Recent clinicopathological cohort studies have led to further refinements in case definition, culminating in a 2013 consensus report, which provides recommendations regarding investigation and treatment. Early clinical experience with complement-targeted therapeutics, notably C5 inhibitors, has also now been published. Here, we summarize the latest developments in C3 glomerulopathy.
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Affiliation(s)
- Thomas D Barbour
- Centre for Complement and Inflammation Research (CCIR), Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Marieta M Ruseva
- Centre for Complement and Inflammation Research (CCIR), Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research (CCIR), Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London W12 0NN, UK
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132
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Sánchez Chinchilla D, Pinto S, Hoppe B, Adragna M, Lopez L, Justa Roldan ML, Peña A, Lopez Trascasa M, Sánchez-Corral P, Rodríguez de Córdoba S. Complement mutations in diacylglycerol kinase-ε-associated atypical hemolytic uremic syndrome. Clin J Am Soc Nephrol 2014; 9:1611-9. [PMID: 25135762 DOI: 10.2215/cjn.01640214] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND OBJECTIVES Atypical hemolytic uremic syndrome is characterized by vascular endothelial damage caused by complement dysregulation. Consistently, complement inhibition therapies are highly effective in most patients with atypical hemolytic uremic syndrome. Recently, it was shown that a significant percentage of patients with early-onset atypical hemolytic uremic syndrome carry mutations in diacylglycerol kinase-ε, an intracellular protein with no obvious role in complement. These data support an alternative, complement-independent mechanism leading to thrombotic microangiopathy that has implications for treatment of early-onset atypical hemolytic uremic syndrome. To get additional insights into this new form of atypical hemolytic uremic syndrome, the diacylglycerol kinase-ε gene in a cohort with atypical hemolytic uremic syndrome was analyzed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Eighty-three patients with early-onset atypical hemolytic uremic syndrome (<2 years) enrolled in the Spanish atypical hemolytic uremic syndrome registry between 1999 and 2013 were screened for mutations in diacylglycerol kinase-ε. These patients were also fully characterized for mutations in the genes encoding factor H, membrane cofactor protein, factor I, C3, factor B, and thrombomodulin CFHRs copy number variations and rearrangements, and antifactor H antibodies. RESULTS Four patients carried mutations in diacylglycerol kinase-ε, one p.H536Qfs*16 homozygote and three compound heterozygotes (p.W322*/p.P498R, two patients; p.Q248H/p.G484Gfs*10, one patient). Three patients also carried heterozygous mutations in thrombomodulin or C3. Extensive plasma infusions controlled atypical hemolytic uremic syndrome recurrences and prevented renal failure in the two patients with diacylglycerol kinase-ε and thrombomodulin mutations. A positive response to plasma infusions and complement inhibition treatment was also observed in the patient with concurrent diacylglycerol kinase-ε and C3 mutations. CONCLUSIONS Data suggest that complement dysregulation influences the onset and disease severity in carriers of diacylglycerol kinase-ε mutations and that treatments on the basis of plasma infusions and complement inhibition are potentially useful in patients with combined diacylglycerol kinase-ε and complement mutations. A comprehensive understanding of the genetic component predisposing to atypical hemolytic uremic syndrome is, therefore, critical to guide an effective treatment.
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Affiliation(s)
- Daniel Sánchez Chinchilla
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
| | - Sheila Pinto
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
| | - Bernd Hoppe
- Department of Pediatrics, Division of Pediatric Nephrology, University of Bonn, Bonn, Germany
| | - Marta Adragna
- Department of Nephrology, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Laura Lopez
- Department of Nephrology, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Maria Luisa Justa Roldan
- Servicio de Nefrología Pediátrica, Hospital Universitario Infantil Miguel Servet, Zaragoza, Spain; and
| | | | - Margarita Lopez Trascasa
- Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain; Unidad de Inmunología, and
| | - Pilar Sánchez-Corral
- Unidad de Investigación, Hospital Universitario La Paz/Instituto de Investigación Hospital Universitario La Paz, Madrid, Spain Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
| | - Santiago Rodríguez de Córdoba
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
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133
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Schramm EC, Clark SJ, Triebwasser MP, Raychaudhuri S, Seddon J, Atkinson JP. Genetic variants in the complement system predisposing to age-related macular degeneration: a review. Mol Immunol 2014; 61:118-125. [PMID: 25034031 DOI: 10.1016/j.molimm.2014.06.032] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 06/20/2014] [Accepted: 06/23/2014] [Indexed: 01/09/2023]
Abstract
Age-related macular degeneration (AMD) is a major cause of visual impairment in the western world. It is characterized by the presence of lipoproteinaceous deposits (drusen) in the inner layers of the retina. Immunohistochemistry studies identified deposition of complement proteins in the drusen as well as in the choroid. In the last decade, genetic studies have linked both common and rare variants in genes of the complement system to increased risk of development of AMD. Here, we review the variants described to date and discuss the functional implications of dysregulation of the alternative pathway of complement in AMD.
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Affiliation(s)
- Elizabeth C Schramm
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Simon J Clark
- Centre for Hearing & Vision Research, Institute of Human Development, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Michael P Triebwasser
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Soumya Raychaudhuri
- Divisions of Rheumatology and Genetics, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Partners Center for Personalized Genetic Medicine, Boston, MA, USA.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
| | - Johanna Seddon
- Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA.,Ophthalmic Epidemiology and Genetics Service, Tufts Medical Center, Boston, MA
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
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134
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Mehta G, Ferreira VP, Skerka C, Zipfel PF, Banda NK. New insights into disease-specific absence of complement factor H related protein C in mouse models of spontaneous autoimmune diseases. Mol Immunol 2014; 62:235-48. [PMID: 25033230 DOI: 10.1016/j.molimm.2014.06.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 06/21/2014] [Indexed: 12/18/2022]
Abstract
Complement factor H (CFH) protein is an inhibitor of the alternative pathway of complement (AP) both in the fluid phase and on the surface of host cells. Mouse and human complement factor H-related (CFHR) proteins also belong to the fH family of plasma glycoproteins. The main goal of the current study was to compare the presence of mRNA for two mCFHR proteins in spontaneously developing autoimmune diseases in mice such as dense deposit disease (DDD), diabetes mellitus (DM), basal laminar deposits (BLD), collagen antibody-induced arthrits (CAIA) and systemic lupus erythematosus (SLE). Here we report for the first time that the CFHR-C mRNA was universally absent in the liver from three strains of lupus-prone mice and in a diabetic-prone mouse strain. The mRNA levels (pg/ng) for CFH and CFHR-B in MRL-lpr/lpr, at 9 wks and 23 wks were 707.2±44.4, 54.5±5.75 and 729±252.9, 74.04±22.76, respectively. The mRNA levels for CFH and CFHR-B in NZB/NZW mice, at 9 wks and 54 wks were 579.9±23.8, 58.8±1.41 and 890.3±135.2, 63.30±9.2, respectively. CFHR-C protein was absent in the circulation of MRL-lpr/lpr and NZB/NZW mice before and after the development of lupus. Similarly, mRNA and protein for CFHR-C was universally absent in liver and other organs and in the circulation of NOD mice before and after the development of DM. In contrast, the mRNAs for CFH, CFHR-B and CFHR-C were universally present in the liver from mice with and without DDD, BLD and CAIA. The levels of mRNA for CFHR-B in mice with and without BLD were ∼4 times higher than the mice with lupus. The complete absence of mRNA for CFHR-C in lupus and diabetic-prone strains indicates that polymorphic variation within the mouse CFHR family exists and raises the possibility that such variation contributes to lupus and diabetic phenotypes.
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Affiliation(s)
- Gaurav Mehta
- University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | | | | | - Peter F Zipfel
- Hans Knoell Institute, Jena, Germany; Friedrich Schiller University, Jena, Germany
| | - Nirmal K Banda
- University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
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135
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Valoti E, Alberti M, Tortajada A, Garcia-Fernandez J, Gastoldi S, Besso L, Bresin E, Remuzzi G, Rodriguez de Cordoba S, Noris M. A novel atypical hemolytic uremic syndrome-associated hybrid CFHR1/CFH gene encoding a fusion protein that antagonizes factor H-dependent complement regulation. J Am Soc Nephrol 2014; 26:209-19. [PMID: 24904082 DOI: 10.1681/asn.2013121339] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Genomic aberrations affecting the genes encoding factor H (FH) and the five FH-related proteins (FHRs) have been described in patients with atypical hemolytic uremic syndrome (aHUS), a rare condition characterized by microangiopathic hemolytic anemia, thrombocytopenia, and ARF. These genomic rearrangements occur through nonallelic homologous recombinations caused by the presence of repeated homologous sequences in CFH and CFHR1-R5 genes. In this study, we found heterozygous genomic rearrangements among CFH and CFHR genes in 4.5% of patients with aHUS. CFH/CFHR rearrangements were associated with poor clinical prognosis and high risk of post-transplant recurrence. Five patients carried known CFH/CFHR1 genes, but we found a duplication leading to a novel CFHR1/CFH hybrid gene in a family with two affected subjects. The resulting fusion protein contains the first four short consensus repeats of FHR1 and the terminal short consensus repeat 20 of FH. In an FH-dependent hemolysis assay, we showed that the hybrid protein causes sheep erythrocyte lysis. Functional analysis of the FHR1 fraction purified from serum of heterozygous carriers of the CFHR1/CFH hybrid gene indicated that the FHR1/FH hybrid protein acts as a competitive antagonist of FH. Furthermore, sera from carriers of the hybrid CFHR1/CFH gene induced more C5b-9 deposition on endothelial cells than control serum. These results suggest that this novel genomic hybrid mediates disease pathogenesis through dysregulation of complement at the endothelial cell surface. We recommend that genetic screening of aHUS includes analysis of CFH and CFHR rearrangements, particularly before a kidney transplant.
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Affiliation(s)
- Elisabetta Valoti
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," and "Centro Anna Maria Astori" Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Marta Alberti
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," and "Centro Anna Maria Astori" Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Agustin Tortajada
- Centro de Investigaciones Biològicas and Centro de Investigacion Biomédica en Enfermedades Rares, Madrid, Spain
| | - Jesus Garcia-Fernandez
- Centro de Investigaciones Biològicas and Centro de Investigacion Biomédica en Enfermedades Rares, Madrid, Spain
| | - Sara Gastoldi
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," and "Centro Anna Maria Astori" Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Luca Besso
- Unit of Nephrology, Dialysis and Transplantation, Molinette Hospital, Turin, Italy; and
| | - Elena Bresin
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," and "Centro Anna Maria Astori" Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," and "Centro Anna Maria Astori" Science and Technology Park Kilometro Rosso, Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | | | - Marina Noris
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," and "Centro Anna Maria Astori" Science and Technology Park Kilometro Rosso, Bergamo, Italy;
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136
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Abstract
IgA nephropathy (IgAN) represents the leading cause of kidney failure among East Asian populations and the most frequent form of primary glomerulonephritis among Europeans. Patients with IgAN develop characteristic IgA1-containing immune complexes that deposit in the glomerular mesangium, producing progressive kidney injury. Recent studies define IgAN as an autoimmune trait of complex architecture with a strong genetic determination. This Review summarizes new insights into the role of the O-glycosylation pathway, anti-glycan immune response, mucosal immunity, antigen processing and presentation, and the alternative complement pathway in the pathogenesis of IgAN.
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137
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Wong EKS, Anderson HE, Herbert AP, Challis RC, Brown P, Reis GS, Tellez JO, Strain L, Fluck N, Humphrey A, Macleod A, Richards A, Ahlert D, Santibanez-Koref M, Barlow PN, Marchbank KJ, Harris CL, Goodship THJ, Kavanagh D. Characterization of a factor H mutation that perturbs the alternative pathway of complement in a family with membranoproliferative GN. J Am Soc Nephrol 2014; 25:2425-33. [PMID: 24722444 DOI: 10.1681/asn.2013070732] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Complement C3 activation is a characteristic finding in membranoproliferative GN (MPGN). This activation can be caused by immune complex deposition or an acquired or inherited defect in complement regulation. Deficiency of complement factor H has long been associated with MPGN. More recently, heterozygous genetic variants have been reported in sporadic cases of MPGN, although their functional significance has not been assessed. We describe a family with MPGN and acquired partial lipodystrophy. Although C3 nephritic factor was shown in family members with acquired partial lipodystrophy, it did not segregate with the renal phenotype. Genetic analysis revealed a novel heterozygous mutation in complement factor H (R83S) in addition to known risk polymorphisms carried by individuals with MPGN. Patients with MPGN had normal levels of factor H, and structural analysis of the mutant revealed only subtle alterations. However, functional analysis revealed profoundly reduced C3b binding, cofactor activity, and decay accelerating activity leading to loss of regulation of the alternative pathway. In summary, this family showed a confluence of common and rare functionally significant genetic risk factors causing disease. Data from our analysis of these factors highlight the role of the alternative pathway of complement in MPGN.
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Affiliation(s)
| | | | | | | | - Paul Brown
- The Renal Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom; and
| | | | | | | | - Nicholas Fluck
- The Renal Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom; and
| | - Ann Humphrey
- The Renal Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom; and
| | - Alison Macleod
- The Renal Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom; and
| | - Anna Richards
- Medical Research Council Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | | | | | - Paul N Barlow
- Edinburgh Biomolecular Nuclear Magnetic Resonance Unit, and
| | - Kevin J Marchbank
- Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Claire L Harris
- Cardiff Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
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138
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Abstract
Although new activation and regulatory mechanisms are still being identified, the basic architecture of the complement system has been known for decades. Two major roles of complement are to control certain bacterial infections and to promote clearance of apoptotic cells. In addition, although inappropriate complement activation has long been proposed to cause tissue damage in human inflammatory and autoimmune diseases, whether this is indeed true has been uncertain. However, recent studies in humans, especially those using newly available biological therapeutics, have now clearly demonstrated the pathophysiologic importance of the complement system in several rare diseases. Beyond these conditions, recent genetic studies have strongly supported an injurious role for complement in a wide array of human inflammatory, degenerative, and autoimmune diseases. This review includes an overview of complement activation, regulatory, and effector mechanisms. It then focuses on new understandings gained from genetic studies, ex vivo analyses, therapeutic trials, and animal models as well as on new research opportunities.
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Affiliation(s)
- V Michael Holers
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado 80045;
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139
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Abstract
Membranoproliferative GN represents a pattern of injury seen on light microscopy. Historically, findings on electron microscopy have been used to further subclassify this pathologic entity. Recent advances in understanding of the underlying pathobiology have led to a proposed classification scheme based on immunofluorescence findings. Dysregulation of the complement system has been shown to be a major risk factor for the development of a membranoproliferative GN pattern of injury on kidney biopsy. Evaluation and treatment of this complex disorder rest on defining the underlying mechanisms.
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Affiliation(s)
- Naveed Masani
- Division of Nephrology, Winthrop University Hospital, Mineola, New York, †Division of Kidney Diseases and Hypertension, Hofstra North Shore-Long Island Jewish School of Medicine, Great Neck, New York
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140
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Abstract
Factor H-related proteins (CFHRs) are plasma glycoproteins related in structure and antigenicity to each other and to the complement inhibitory protein factor H. Such proteins are found in most mammals but their number and domain composition vary. This chapter summarizes our current knowledge on the human factor H-related proteins. In contrast to factor H, they have no strong complement inhibitory activity, although for some of them regulatory or complement modulatory activity has been reported. A common feature of CFHRs is that they bind to the C3b component of complement. Novel links between CFHRs and various diseases (C3 glomerulopathies, atypical hemolytic uremic syndrome and age-related macular degeneration) have been revealed in recent years, but we are still far from understanding their biological function.
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141
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An ELISA assay with two monoclonal antibodies allows the estimation of free factor H and identifies patients with acquired deficiency of this complement regulator. Mol Immunol 2013; 58:194-200. [PMID: 24378252 DOI: 10.1016/j.molimm.2013.11.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/25/2013] [Accepted: 11/26/2013] [Indexed: 02/02/2023]
Abstract
Complement factor H (FH) serum levels can be affected by the presence of immune complexes of FH with autoantibodies like in autoimmune forms of atypical haemolytic uraemic syndrome (aHUS) or with C3b in homozygous factor I (FI) deficiency. These complexes reduce the amount of free functional circulating FH. In this study we aimed to determine whether FH levels measurement is disturbed in some pathological conditions and to establish a method for quantifying free and total FH in serum. For that purpose, FH levels were measured in serum samples from aHUS patients having anti-FH autoantibodies or mutations in FH gene, in patients with homozygous FI deficiency, and in healthy controls. Two anti-FH monoclonal antibodies, OX24 and A229, recognizing different functional regions in FH, were used as capture antibodies in an ELISA assay. In the control group and in the group of patients with FH mutations, the FH levels obtained with the two monoclonal antibodies were similar. In patients with anti-FH autoantibodies or with homozygous FI deficiency, however, FH levels measured with both antibodies were significantly different. As these patients had complexes of FH with autoantibodies or C3b, we interpreted that OX24 was detecting total FH and A229 was recognising free FH. Therefore, quantification of FH in plasma using these two monoclonal antibodies provides not only total FH level but also gives an estimation of how much FH circulates free and is thus available to properly control complement activation.
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142
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Taranta-Janusz K, Wasilewska A, Szynaka B. Childhood-onset dense deposit disease: a rare cause of proteinuria. Ir J Med Sci 2013; 183:455-9. [PMID: 24338037 PMCID: PMC4099529 DOI: 10.1007/s11845-013-1041-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 11/13/2013] [Indexed: 11/28/2022]
Abstract
Introduction Dense deposit disease (DDD) is a rare renal disease related to the dysregulation of the alternative pathway of the complement cascade, caused by several factors including the presence of an autoantibody to C3 nephritic factor, mutations in factor H and autoantibodies to this protein. DDD is characterized by C3 accumulation with absent or scanty immunoglobulin deposition. Case Presentation Herein we report the case of a child with benign course of DDD, who presented with moderate proteinuria and lack of clinical symptoms without immunosuppressive treatment. Laboratory testing revealed moderate proteinuria, normal serum creatinine, total protein, and albumin levels, but significantly decreased serum C3 level. The results of renal biopsy were consistent with DDD. Genetic analysis revealed that the patient carried one copy of the H402 risk allele of factor H. The level of proteinuria did not change during the follow-up period and no nephrotic syndrome signs occurred. Renal function was stable. Conclusion In conclusion, a program of urine screening for asymptomatic proteinuria and hematuria to detect children with kidney disease before they experience loss of kidney functions should be considered. Children diagnosed with DDD should have the opportunity to get treatment early on and to be followed very closely.
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Affiliation(s)
- K Taranta-Janusz
- Department of Pediatrics and Nephrology, Medical University of Białystok, Waszyngtona 17, 15-274, Białystok, Poland
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143
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Chen Q, Wiesener M, Eberhardt HU, Hartmann A, Uzonyi B, Kirschfink M, Amann K, Buettner M, Goodship T, Hugo C, Skerka C, Zipfel PF. Complement factor H-related hybrid protein deregulates complement in dense deposit disease. J Clin Invest 2013; 124:145-55. [PMID: 24334459 DOI: 10.1172/jci71866] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 10/07/2013] [Indexed: 12/16/2022] Open
Abstract
The renal disorder C3 glomerulopathy with dense deposit disease (C3G-DDD) pattern results from complement dysfunction and primarily affects children and young adults. There is no effective treatment, and patients often progress to end-stage renal failure. A small fraction of C3G-DDD cases linked to factor H or C3 gene mutations as well as autoantibodies have been reported. Here, we examined an index family with 2 patients with C3G-DDD and identified a chromosomal deletion in the complement factor H-related (CFHR) gene cluster. This deletion resulted in expression of a hybrid CFHR2-CFHR5 plasma protein. The recombinant hybrid protein stabilized the C3 convertase and reduced factor H-mediated convertase decay. One patient was refractory to plasma replacement and exchange therapy, as evidenced by the hybrid protein quickly returning to pretreatment plasma levels. Subsequently, complement inhibitors were tested on serum from the patient for their ability to block activity of CFHR2-CFHR5. Soluble CR1 restored defective C3 convertase regulation; however, neither eculizumab nor tagged compstatin had any effect. Our findings provide insight into the importance of CFHR proteins for C3 convertase regulation and identify a genetic variation in the CFHR gene cluster that promotes C3G-DDD. Monitoring copy number and sequence variations in the CFHR gene cluster in C3G-DDD and kidney patients with C3G-DDD variations will help guide treatment strategies.
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144
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Interaction of Shiga toxin 2 with complement regulators of the factor H protein family. Mol Immunol 2013; 58:77-84. [PMID: 24317278 DOI: 10.1016/j.molimm.2013.11.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 11/13/2013] [Indexed: 01/20/2023]
Abstract
Shiga toxin 2 (Stx2) is believed to be a major virulence factor of enterohemorrhagic Escherichia coli (EHEC) contributing to hemolytic uremic syndrome (HUS). The complement system has recently been found to be involved in the pathogenesis of EHEC-associated HUS. Stx2 was shown to activate complement via the alternative pathway, to bind factor H (FH) at short consensus repeats (SCRs) 6-8 and 18-20 and to delay and reduce FH cofactor activity on the cell surface. We now show that complement factor H-related protein 1 (FHR-1) and factor H-like protein 1 (FHL-1), proteins of the FH protein family that show amino acid sequence and regulatory function similarities with FH, also bind to Stx2. The FHR-1 binding site for Stx2 was located at SCRs 3-5 and the binding capacity of FHR-1*A allotype was higher than that of FHR-1*B. FHR-1 and FHL-1 competed with FH for Stx2 binding, and in the case of FHR-1 this competition resulted in a reduction of FH cofactor activity. FHL-1 retained its cofactor activity in the fluid phase when bound to Stx2. In conclusion, multiple interactions of key complement inhibitors FH, FHR-1 and FHL-1 with Stx2 corroborate our hypothesis of a direct role of complement in EHEC-associated HUS.
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145
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Human factor H-related protein 2 (CFHR2) regulates complement activation. PLoS One 2013; 8:e78617. [PMID: 24260121 PMCID: PMC3832495 DOI: 10.1371/journal.pone.0078617] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Accepted: 09/13/2013] [Indexed: 11/25/2022] Open
Abstract
Mutations and deletions within the human CFHR gene cluster on chromosome 1 are associated with diseases, such as dense deposit disease, CFHR nephropathy or age-related macular degeneration. Resulting mutant CFHR proteins can affect complement regulation. Here we identify human CFHR2 as a novel alternative pathway complement regulator that inhibits the C3 alternative pathway convertase and terminal pathway assembly. CFHR2 is composed of four short consensus repeat domains (SCRs). Two CFHR2 molecules form a dimer through their N-terminal SCRs, and each of the two C-terminal ends can bind C3b. C3b bound CFHR2 still allows C3 convertase formation but the CFHR2 bound convertases do not cleave the substrate C3. Interestingly CFHR2 hardly competes off factor H from C3b. Thus CFHR2 likely acts in concert with factor H, as CFHR2 inhibits convertases while simultaneously allowing factor H assisted degradation by factor I.
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146
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C3 glomerulopathy: consensus report. Kidney Int 2013; 84:1079-89. [PMID: 24172683 PMCID: PMC3842953 DOI: 10.1038/ki.2013.377] [Citation(s) in RCA: 409] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/30/2013] [Accepted: 06/20/2013] [Indexed: 02/06/2023]
Abstract
C3 glomerulopathy is a recently introduced pathological entity whose original definition was glomerular pathology characterized by C3 accumulation with absent or scanty immunoglobulin deposition. In August 2012, an invited group of experts (comprising the authors of this document) in renal pathology, nephrology, complement biology, and complement therapeutics met to discuss C3 glomerulopathy in the first C3 Glomerulopathy Meeting. The objectives were to reach a consensus on: the definition of C3 glomerulopathy, appropriate complement investigations that should be performed in these patients, and how complement therapeutics should be explored in the condition. This meeting report represents the current consensus view of the group.
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147
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A novel CFHR5 fusion protein causes C3 glomerulopathy in a family without Cypriot ancestry. Kidney Int 2013; 85:933-7. [PMID: 24067434 PMCID: PMC3789233 DOI: 10.1038/ki.2013.348] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/02/2013] [Accepted: 07/12/2013] [Indexed: 02/06/2023]
Abstract
C3 glomerulopathy describes glomerular pathology associated with predominant deposition of complement C3 including dense deposit disease and C3 glomerulonephritis. Familial C3 glomerulonephritis has been associated with rearrangements affecting the complement factor H-related (CFHR) genes. These include a hybrid CFHR3-1 gene and an internal duplication within the CFHR5 gene. CFHR5 nephropathy, to date, occurred exclusively in patients with Cypriot ancestry, and is associated with a heterozygous internal duplication of the CFHR5 gene resulting in duplication of the exons encoding the first two domains of the CFHR5 protein. Affected individuals possess both the wild-type nine-domain CFHR5 protein (CFHR5(12-9)) and an abnormally large mutant CFHR5 protein in which the initial two protein domains are duplicated (CFHR5(1212-9)). We found CFHR5(1212-9) in association with familial C3 glomerulonephritis in a family without Cypriot ancestry. The genomic rearrangement was distinct from that seen in Cypriot CFHR5 nephropathy. Our findings strengthen the association between CFHR5(1212-9) and familial C3 glomerulonephritis and recommend screening for CFHR5(1212-9) in patients with C3 glomerulopathy irrespective of ethnicity. Since CFHR5(1212-9) can result from at least two genomic rearrangements, screening is most readily achieved through analysis of CFHR5 protein.
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148
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Holers VM. Human C3 glomerulopathy provides unique insights into complement factor H-related protein function. J Clin Invest 2013; 123:2357-60. [PMID: 23728171 DOI: 10.1172/jci69684] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The study in this issue of the JCI by Tortajada et al. demonstrates that a duplication within the gene complement factor H–related 1 (CFHR1; encoding FHR1) leads to the production of an aberrant larger form of the protein. Elegant in vitro studies of the mutant and normal variants demonstrate an unexpected mechanism of action of FHR1, wherein homodimeration and hetero- oligomerization with FHR2 and FHR5 generates more avid molecules that very effectively compete with FH binding to surfaces and impair its ability to regulate local complement activation. As variants of FHRs are linked to many human inflammatory and autoimmune diseases, these and other recently published structure/function studies of these proteins provide key insights into their complement regulatory activities and likely roles in disease.
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Affiliation(s)
- V Michael Holers
- Department of Medicine, Division of Rheumatology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
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149
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Skerka C, Chen Q, Fremeaux-Bacchi V, Roumenina LT. Complement factor H related proteins (CFHRs). Mol Immunol 2013; 56:170-80. [PMID: 23830046 DOI: 10.1016/j.molimm.2013.06.001] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 05/08/2013] [Indexed: 02/06/2023]
Abstract
Factor H related proteins comprise a group of five plasma proteins: CFHR1, CFHR2, CFHR3, CFHR4 and CFHR5, and each member of this group binds to the central complement component C3b. Mutations, genetic deletions, duplications or rearrangements in the individual CFHR genes are associated with a number of diseases including atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathies (C3 glomerulonephritis (C3GN), dense deposit disease (DDD) and CFHR5 nephropathy), IgA nephropathy, age related macular degeneration (AMD) and systemic lupus erythematosus (SLE). Although complement regulatory functions were attributed to most of the members of the CFHR protein family, the precise role of each CFHR protein in complement activation and the exact contribution to disease pathology is still unclear. Recent publications show that CFHR proteins form homo- as well as heterodimers. Genetic abnormalities within the CFHR gene locus can result in hybrid proteins with affected dimerization or recognition domains which cause defective functions. Here we summarize the recent data about CFHR genes and proteins in order to better understand the role of CFHR proteins in complement activation and in complement associated diseases.
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Affiliation(s)
- Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.
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150
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Familial CFHR1 mutation identified in C3 glomerulopathy. Nat Rev Nephrol 2013. [DOI: 10.1038/nrneph.2013.92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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