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Krzyżewska-Dudek E, Kotimaa J, Kapczyńska K, Rybka J, Meri S. Lipopolysaccharides and outer membrane proteins as main structures involved in complement evasion strategies of non-typhoidal Salmonella strains. Mol Immunol 2022; 150:67-77. [PMID: 35998438 DOI: 10.1016/j.molimm.2022.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/27/2022]
Abstract
Non-typhoidal Salmonella (NTS) infections pose a serious public health problem. In addition to the typical course of salmonellosis, an infection with Salmonella bacteria can often lead to parenteral infections and sepsis, which are particularly dangerous for children, the elderly and immunocompromised. Bacterial resistance to serum is a key virulence factor for the development of systemic infections. Salmonella, as an enterobacterial pathogen, has developed several mechanisms to escape and block the antibacterial effects of the complement system. In this review, we discuss the relevance of outer membrane polysaccharides to the complement evasion mechanisms of NTS strains. These include the influence of the overall length and density of the lipopolysaccharide molecules, modifications of the O-antigen lipopolysaccharide composition and the role of capsular polysaccharides in opsonization and protection of the outer membrane from the lytic action of complement. Additionally, we discuss specific outer membrane protein complement evasion mechanisms, such as recruitment of complement regulatory proteins, blocking assembly of late complement components to form the membrane attack complex and the proteolytic cleavage of complement proteins.
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Affiliation(s)
- E Krzyżewska-Dudek
- Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, and Diagnostic Center (HUSLAB), Helsinki University Hospital, 00290 Helsinki, Finland; Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland
| | - J Kotimaa
- Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, and Diagnostic Center (HUSLAB), Helsinki University Hospital, 00290 Helsinki, Finland
| | - K Kapczyńska
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland
| | - J Rybka
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland
| | - S Meri
- Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, and Diagnostic Center (HUSLAB), Helsinki University Hospital, 00290 Helsinki, Finland.
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SEPPÄLÄ M, Kovala M, Räisänen-Sokolowski A, Meri S, Honkanen E, Lievonen J, Kaartinen K. POS-025 COMPLEMENT MEDIATED MONOCLONAL GAMMOPATHY OF RENAL SIGNIFICANCE (MGRS). Kidney Int Rep 2022. [DOI: 10.1016/j.ekir.2022.04.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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3
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Vuorela A, Freitag TL, Leskinen K, Pessa H, Härkönen T, Stracenski I, Kirjavainen T, Olsen P, Saarenpää-Heikkilä O, Ilonen J, Knip M, Vaheri A, Partinen M, Saavalainen P, Meri S, Vaarala O. Enhanced influenza A H1N1 T cell epitope recognition and cross-reactivity to protein-O-mannosyltransferase 1 in Pandemrix-associated narcolepsy type 1. Nat Commun 2021; 12:2283. [PMID: 33863907 PMCID: PMC8052463 DOI: 10.1038/s41467-021-22637-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/18/2021] [Indexed: 02/06/2023] Open
Abstract
Narcolepsy type 1 (NT1) is a chronic neurological disorder having a strong association with HLA-DQB1*0602, thereby suggesting an immunological origin. Increased risk of NT1 has been reported among children or adolescents vaccinated with AS03 adjuvant-supplemented pandemic H1N1 influenza A vaccine, Pandemrix. Here we show that pediatric Pandemrix-associated NT1 patients have enhanced T-cell immunity against the viral epitopes, neuraminidase 175-189 (NA175-189) and nucleoprotein 214-228 (NP214-228), but also respond to a NA175-189-mimic, brain self-epitope, protein-O-mannosyltransferase 1 (POMT1675-689). A pathogenic role of influenza virus-specific T-cells and T-cell cross-reactivity in NT1 are supported by the up-regulation of IFN-γ, perforin 1 and granzyme B, and by the converging selection of T-cell receptor TRAV10/TRAJ17 and TRAV10/TRAJ24 clonotypes, in response to stimulation either with peptide NA175-189 or POMT1675-689. Moreover, anti-POMT1 serum autoantibodies are increased in Pandemrix-vaccinated children or adolescents. These results thus identify POMT1 as a potential autoantigen recognized by T- and B-cells in NT1.
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Affiliation(s)
- A Vuorela
- Clinicum, University of Helsinki, Helsinki, Finland
| | - T L Freitag
- Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland.
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.
| | - K Leskinen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - H Pessa
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - T Härkönen
- Clinicum, University of Helsinki, Helsinki, Finland
| | - I Stracenski
- Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
| | - T Kirjavainen
- Children's Hospital, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland
| | - P Olsen
- Department of Child Neurology, Oulu University Hospital, Oulu, Finland
| | | | - J Ilonen
- Immunogenetics Laboratory, Institute of Biomedicine, University of Turku, Turku, Finland
- Clinical Microbiology, Turku University Hospital, Turku, Finland
| | - M Knip
- Clinicum, University of Helsinki, Helsinki, Finland
- Children's Hospital, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, University of Helsinki, Helsinki, Finland
| | - A Vaheri
- Department of Virology, University of Helsinki, Helsinki, Finland
| | - M Partinen
- Clinicum, University of Helsinki, Helsinki, Finland
- Department of Neurosciences, University of Helsinki, Helsinki, Finland
- Helsinki Sleep Clinic, Vitalmed Research Center, Helsinki, Finland
| | - P Saavalainen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - S Meri
- Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - O Vaarala
- Clinicum, University of Helsinki, Helsinki, Finland
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Lokki AI, Teirilä L, Triebwasser M, Daly E, Bhattacharjee A, Uotila L, Llort Asens M, Kurki MI, Perola M, Auro K, Salmon JE, Daly M, Atkinson JP, Laivuori H, Fagerholm S, Meri S. Dysfunction of complement receptors CR3 (CD11b/18) and CR4 (CD11c/18) in pre-eclampsia: a genetic and functional study. BJOG 2021; 128:1282-1291. [PMID: 33539617 DOI: 10.1111/1471-0528.16660] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To study genetic variants and their function within genes coding for complement receptors in pre-eclampsia. DESIGN A case-control study. SETTING Pre-eclampsia is a common vascular disease of pregnancy. The clearance of placenta-derived material is one of the functions of the complement system in pregnancy. POPULATION We genotyped 500 women with pre-eclamptic pregnancies and 190 pregnant women without pre-eclampsia, as controls, from the FINNPEC cohort, and 122 women with pre-eclamptic pregnancies and 1905 controls from the national FINRISK cohort. METHODS The functional consequences of genotypes discovered by targeted exomic sequencing were explored by analysing the binding of the main ligand iC3b to mutated CR3 or CR4, which were transiently expressed on the surface of COS-1 cells. MAIN OUTCOME MEASURES Allele frequencies were compared between pre-eclamptic pregnancies and controls in genetic studies. The functional consequences of selected variants were measured by binding assays. RESULTS The most significantly pre-eclampsia-linked CR3 variant M441K (P = 4.27E-4, OR = 1.401, 95% CI = 1.167-1.682) displayed a trend of increased adhesion to iC3b (P = 0.051). The CR4 variant A251T was found to enhance the adhesion of CR4 to iC3b, whereas W48R resulted in a decrease of the binding of CR4 to iC3b. CONCLUSIONS Results suggest that changes in complement-facilitated phagocytosis are associated with pre-eclampsia. Further studies are needed to ascertain whether aberrant CR3 and CR4 activity leads to altered pro- and anti-inflammatory cytokine responses in individuals carrying the associated variants, and the role of these receptors in pre-eclampsia pathogenesis. TWEETABLE ABSTRACT Genetic variants of complement receptors CR3 and CR4 have functional consequences that are associated with pre-eclampsia.
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Affiliation(s)
- A I Lokki
- Translational Immunology Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Department of Obstetrics and Gynecology, Faculty of Medicine and Health Technology, Tampere University Hospital, Tampere University, Tampere, Finland
| | - L Teirilä
- Translational Immunology Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Bacteriology and immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - M Triebwasser
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, Saint Louis, MO, USA
| | - E Daly
- Hospital and Harvard Medical School, Boston, MA, USA
| | - A Bhattacharjee
- Herantis Pharma Plc, Espoo, Finland.,Neuroscience Center, HiLife, University of Helsinki, Helsinki, Finland
| | - L Uotila
- Research Services, University of Helsinki, Helsinki, Finland
| | - M Llort Asens
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - M I Kurki
- Neurosurgery of Neuro Center, Kuopio University Hospital, Finland.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - M Perola
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
| | - K Auro
- Department of Government Services, National Institute for Health and Welfare, Helsinki, Finland
| | - J E Salmon
- Hospital for Special Surgery-Weill Cornell Medicine, Department of Medicine, New York, NY, USA
| | - M Daly
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA.,Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - J P Atkinson
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, Saint Louis, MO, USA
| | - H Laivuori
- Department of Obstetrics and Gynecology, Faculty of Medicine and Health Technology, Tampere University Hospital, Tampere University, Tampere, Finland.,Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.,Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - S Fagerholm
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - S Meri
- Translational Immunology Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Bacteriology and immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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- Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Riihilä P, Viiklepp K, Nissinen L, Farshchian M, Kallajoki M, Kivisaari A, Meri S, Peltonen J, Peltonen S, Kähäri V. 酶 C1r 和 C1s 可能显示一种皮肤癌(角质形成细胞源性皮肤鳞状细胞癌)的进展. Br J Dermatol 2020. [DOI: 10.1111/bjd.18834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Riihilä P, Viiklepp K, Nissinen L, Farshchian M, Kallajoki M, Kivisaari A, Meri S, Peltonen J, Peltonen S, Kähäri V. Enzymes C1r and C1s may show progression of a type of skin cancer called keratinocyte‐derived cutaneous squamous cell carcinoma. Br J Dermatol 2020. [DOI: 10.1111/bjd.18821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Viiklepp K, Nissinen L, Ojalill M, Riihilä P, Meri S, Heino J, Kähäri V. 447 Complement component C1r upregulates the expression of matrix metalloproteinase-1, -13 and -10 and promotes invasion of cutaneous squamous carcinoma cells. J Invest Dermatol 2019. [DOI: 10.1016/j.jid.2019.07.497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Riihilä P, Viiklepp K, Nissinen L, Farshchian M, Kallajoki M, Kivisaari A, Meri S, Peltonen J, Peltonen S, Kähäri VM. Tumour-cell-derived complement components C1r and C1s promote growth of cutaneous squamous cell carcinoma. Br J Dermatol 2019; 182:658-670. [PMID: 31049937 PMCID: PMC7065064 DOI: 10.1111/bjd.18095] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2019] [Indexed: 12/13/2022]
Abstract
Background The incidence of epidermal keratinocyte‐derived cutaneous squamous cell carcinoma (cSCC) is increasing worldwide. Objectives To study the role of the complement classical pathway components C1q, C1r and C1s in the progression of cSCC. Methods The mRNA levels of C1Q subunits and C1R and C1S in cSCC cell lines, normal human epidermal keratinocytes, cSCC tumours in vivo and normal skin were analysed with quantitative real‐time polymerase chain reaction. The production of C1r and C1s was determined with Western blotting. The expression of C1r and C1s in tissue samples in vivo was analysed with immunohistochemistry and further investigated in human cSCC xenografts by knocking down C1r and C1s. Results Significantly elevated C1R and C1S mRNA levels and production of C1r and C1s were detected in cSCC cells, compared with normal human epidermal keratinocytes. The mRNA levels of C1R and C1S were markedly elevated in cSCC tumours in vivo compared with normal skin. Abundant expression of C1r and C1s by tumour cells was detected in invasive sporadic cSCCs and recessive dystrophic epidermolysis bullosa‐associated cSCCs, whereas the expression of C1r and C1s was lower in cSCC in situ, actinic keratosis and normal skin. Knockdown of C1r and C1s expression in cSCC cells inhibited activation of extracellular signal‐related kinase 1/2 and Akt, promoted apoptosis of cSCC cells and significantly suppressed growth and vascularization of human cSCC xenograft tumours in vivo. Conclusions These results provide evidence for the role of tumour‐cell‐derived C1r and C1s in the progression of cSCC and identify them as biomarkers and putative therapeutic targets in cSCC. What's already known about this topic? The incidences of actinic keratosis, cutaneous squamous cell carcinoma (cSCC) in situ and invasive cSCC are increasing globally. Few specific biomarkers for progression of cSCC have been identified, and no biological markers are in clinical use to predict the aggressiveness of actinic keratosis, cSCC in situ and invasive cSCC.
What does this study add? Our results provide novel evidence for the role of complement classical pathway components C1r and C1s in the progression of cSCC.
What is the translational message? Our results identify complement classical pathway components C1r and C1s as biomarkers and putative therapeutic targets in cSCC.
Linked Comment: https://doi.org/10.1111/bjd.18419. https://doi.org/10.1111/bjd.18821 available online
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Affiliation(s)
- P Riihilä
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland.,The Western Cancer Centre of the Cancer Center Finland (FICAN West), University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland
| | - K Viiklepp
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland.,The Western Cancer Centre of the Cancer Center Finland (FICAN West), University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland
| | - L Nissinen
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland.,The Western Cancer Centre of the Cancer Center Finland (FICAN West), University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland
| | - M Farshchian
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - M Kallajoki
- Department of Pathology, Turku University Hospital, Turku, Finland
| | - A Kivisaari
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - S Meri
- Haartman Institute, University of Helsinki, Helsinki, Finland
| | - J Peltonen
- Department of Anatomy and Cell Biology, University of Turku, Turku, Finland
| | - S Peltonen
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland
| | - V-M Kähäri
- Department of Dermatology, University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland.,The Western Cancer Centre of the Cancer Center Finland (FICAN West), University of Turku and Turku University Hospital, Hämeentie 11 TE6, FI-20520, Turku, Finland
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Koskinen AR, Cheng ZZ, Pickering MC, Kairemo K, Meri T, Cook HT, Meri S, Jokiranta TS. Distribution of exogenous complement factor H in mice in vivo. Scand J Immunol 2018; 88:e12671. [PMID: 29706017 DOI: 10.1111/sji.12671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/24/2018] [Indexed: 11/29/2022]
Abstract
Factor H is an important regulator of complement activation in plasma and on cell surfaces in both humans and mice. If FH function is compromised, inappropriate complement activation on self-surfaces can have disastrous effects as seen in the kidney diseases atypical haemolytic uremic syndrome (aHUS) and C3 glomerulopathy. As FH constructs have been proposed to be used in treatment for these diseases, we studied the distribution of exogenous FH fragments in mice. Full-length mFH, mFH1-5 and mFH18-20 fragments were radiolabelled, and their distribution was examined in WT, FH-/- and FH-/- C3-/- mice in vivo. Whole body scintigraphy revealed accumulation of radioactivity in the abdominal part of the mice, but also to the thyroid gland and urinary bladder. At organ level in WT mice, some full-length FH accumulated in internal organs, but most of it remained in the circulation. Both of the mFH fragments accumulated in the kidneys and were excreted in urine. For mFH1-5, urinary secretion is the likely cause for the accumulation. Concentration of mFH18-20 to kidneys was slower, and at tissue level, mFH18-20 was localized at the proximal tubuli in WT and FH-/- C3-/- mice. No C3-independent binding to glomeruli was detected. In conclusion, these results show that glomerular glycosaminoglycans and sialic acids alone do not collect FH in kidneys. Deposition of C3 fragments is also needed, which implies that in aHUS, the problem is in simultaneous recognition of C3 fragments and glycosaminoglycans or sialic acids by FH, not just the inability of FH to recognize glomerular endothelium as such.
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Affiliation(s)
- A R Koskinen
- Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Z-Z Cheng
- Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - M C Pickering
- Center for Complement and Inflammation Research, Imperial College London, London, UK
| | - K Kairemo
- Department of Clinical Chemistry Institute of Clinical Medicine, University of Helsinki, Helsinki, Finland
| | - T Meri
- Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - H T Cook
- Center for Complement and Inflammation Research, Imperial College London, London, UK
| | - S Meri
- Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - T S Jokiranta
- Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
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Abstract
It has become increasingly apparent that the complement system, being an ancient defense mechanism, is not operative only in the extracellular milieu but also intracellularly. In addition to the known synthetic machinery in the liver and by macrophages, many other cell types, including lymphocytes, adipocytes and epithelial cells produce selected complement components. Activation of e.g. C3 and C5 inside cells may have multiple effects ranging from direct antimicrobial defense to cell differentiation and possible influence on metabolism. Intracellular activation of C3 and C5 in T cells is involved in the maintenance of immunological tolerance and promotes differentiation of T helper cells into Th1-type cells that activate cell-mediated immune responses. Adipocytes are unique in producing many complement sensor proteins (like C1q) and Factor D (adipsin), the key enzyme in promoting alternative pathway amplification. The effects of complement activation products are mediated by intracellular and cell membrane receptors, like C3aR, C5aR1, C5aR2 and the complement regulator MCP/CD46, often jointly with other receptors like the T cell receptor, Toll-like receptors and those of the inflammasomes. These recent observations link complement activation to cellular metabolic processes, intracellular defense reactions and to diverse adaptive immune responses. The complement components may thus be viewed as intracellular alarm molecules involved in the cellular danger response.
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Affiliation(s)
- M P Reichhardt
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
| | - S Meri
- Department of Bacteriology and Immunology, Haartman Institute, Immunobiology Research Program, University of Helsinki, Helsinki, Finland; Helsinki University Central Hospital Laboratory (HUSLAB), Helsinki, Finland.
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11
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Dyggve H, Jarva H, Spillmann T, Speeti M, Meri S. Identification of Glyceraldehyde-3-Phosphate and Alcohol Dehydrogenases as Autoantigens in Doberman Hepatitis. Scand J Immunol 2017; 86:156-164. [PMID: 29072876 DOI: 10.1111/sji.12575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 06/11/2017] [Indexed: 11/30/2022]
Abstract
An autoimmune background is suspected for Doberman hepatitis (DH). It is based on the finding of mononuclear cell infiltrates in the liver, strong female bias, association to the homozygous risk factor dog leucocyte antigen (DLA) allele DRB1*00601 and aberrant major histocompatibility complex (MHC) class II expression on hepatocytes that correlates with the degree of inflammation in the liver. The aim of this study was to search for autoantibodies against liver-related antigens associated with DH. Twenty-five Dobermans with subclinical DH (SDH), 13 that clinically manifest DH (CDH) and 17 healthy controls were studied. Immunoblotting analysis detected specific antibodies in the DH sera. By mass spectrometry the targets were identified as liver-related enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and alcohol dehydrogenase (ADH). Using ELISA, anti-GAPDH IgG was detected in 36% (9/25) of SDH dogs and 69.2% (9/13) of the CDH dogs compared to healthy controls (0/17) (P < 0.0005). Anti-ADH IgG was detected in 72% (18/25) of SDH dogs and 76.9% (10/13) of CDH dogs and only in one (1/17) control (P < 0.0005). The finding of novel autoantigens, GAPDH and ADH strengthen the hypothesis that DH is an autoimmune disease of the liver. These findings suggest that DH could be diagnosed by screening for autoantibodies against the defined antigens.
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Affiliation(s)
- H Dyggve
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.,Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki and HUSLAB, Helsinki University Hospital, Helsinki, Finland
| | - H Jarva
- Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki and HUSLAB, Helsinki University Hospital, Helsinki, Finland
| | - T Spillmann
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
| | - M Speeti
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
| | - S Meri
- Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki and HUSLAB, Helsinki University Hospital, Helsinki, Finland
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12
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Dyggve H, Meri S, Spillmann T, Jarva H, Speeti M. Antihistone Autoantibodies in Dobermans With Hepatitis. J Vet Intern Med 2017; 31:1717-1723. [PMID: 28963850 PMCID: PMC5697184 DOI: 10.1111/jvim.14838] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 06/25/2017] [Accepted: 08/21/2017] [Indexed: 12/16/2022] Open
Abstract
Background Immune system involvement is suggested as an underlying cause for Doberman hepatitis (DH) based on female predisposition, lymphocyte infiltration, abnormal hepatocyte expression of major histocompatibility complex class II antigens, and homozygosity for dog leukocyte antigen DRB1*00601. Objective To measure serum antinuclear antibodies (ANA) and serum antihistone antibodies (AHA) in Dobermans with hepatitis. To determine whether increased serum ANA or serum AHA could be used to support the diagnosis of Doberman hepatitis (DH). Animals Privately owned 25 subclinically and 13 clinically affected DH Dobermans and 17 healthy control Dobermans. Methods Case–control study. Indirect immunofluorescence (IIF) microscopy and line blot tests were employed for the ANA pilot studies and an enzyme‐linked immunosorbent assay (ELISA) assay for detection of IgG AHA. Results Indirect immunofluorescence revealed ANA‐positive cases, and line blot showed AHA reactivity. In ELISA, importantly increased concentrations of AHA were found in 92% (23/25) of dogs in the subclinical stage and 84.6% (11 of 13) of dogs in the clinical stage of DH compared with no control dogs (0/17) (P < 0.0005). The mean AHA absorbance values of the blood samples obtained from the 25 subclinical DH dogs (1.36 ± 0.60, mean ± SD) and the 13 clinically affected dogs (1.46 ± 0.49) were significantly higher than in 17 control dogs (0.51 ± 0.18; P < 0.0001). Conclusions and Clinical Importance As the presence of AHA indicates autoimmune activity, our results favor an autoimmune background as one cause for DH. Antihistone antibody could represent a novel means for screening Dobermans with increased serum alanine transaminase concentrations and suspicion of DH.
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Affiliation(s)
- H Dyggve
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.,Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki and HUSLAB, Helsinki, Finland
| | - S Meri
- Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki and HUSLAB, Helsinki, Finland
| | - T Spillmann
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
| | - H Jarva
- Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki and HUSLAB, Helsinki, Finland
| | - M Speeti
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
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13
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Nissilä E, Korpela K, Lokki AI, Paakkanen R, Jokiranta S, de Vos WM, Lokki ML, Kolho KL, Meri S. C4B gene influences intestinal microbiota through complement activation in patients with paediatric-onset inflammatory bowel disease. Clin Exp Immunol 2017; 190:394-405. [PMID: 28832994 DOI: 10.1111/cei.13040] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2017] [Indexed: 12/19/2022] Open
Abstract
Complement C4 genes are linked to paediatric inflammatory bowel disease (PIBD), but the mechanisms have remained unclear. We examined the influence of C4B gene number on intestinal microbiota and in-vitro serum complement activation by intestinal microbes in PIBD patients. Complement C4A and C4B gene numbers were determined by genomic reverse transcription-polymerase chain reaction (RT-PCR) from 64 patients with PIBD (Crohn's disease or ulcerative colitis). The severity of the disease course was determined from faecal calprotectin levels. Intestinal microbiota was assessed using the HITChip microarray. Complement reactivity in patients was analysed by incubating their sera with Yersinia pseudotuberculosis and Akkermansia muciniphila and determining the levels of C3a and soluble terminal complement complex (SC5b-9) using enzyme immunoassays. The microbiota diversity was wider in patients with no C4B genes than in those with one or two C4B genes, irrespective of intestinal inflammation. C4B and total C4 gene numbers correlated positively with soluble terminal complement complex (TCC, SC5b-9) levels when patient serum samples were stimulated with bacteria. Our results suggest that the C4B gene number associates positively with inflammation in patients with PIBD. Multiple copies of the C4B gene may thus aggravate the IBD-associated dysbiosis through escalated complement reactivity towards the microbiota.
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Affiliation(s)
- E Nissilä
- Immunobiology, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
| | - K Korpela
- Immunobiology, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - A I Lokki
- Immunobiology, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| | - R Paakkanen
- Transplantation Laboratory, Medicum, University of Helsinki, Helsinki, Finland
| | - S Jokiranta
- Immunobiology, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
| | - W M de Vos
- Immunobiology, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - M-L Lokki
- Transplantation Laboratory, Medicum, University of Helsinki, Helsinki, Finland
| | - K-L Kolho
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - S Meri
- Immunobiology, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland.,Helsinki University Hospital Laboratory (HUSLAB), Helsinki, Finland
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14
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Reichhardt M, Holmskov U, Meri S. SALSA—A dance on a slippery floor with changing partners. Mol Immunol 2017; 89:100-110. [DOI: 10.1016/j.molimm.2017.05.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/31/2017] [Accepted: 05/31/2017] [Indexed: 02/06/2023]
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15
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Aronen HJ, Kivisaari L, Torstila I, Paavonen T, Meri S, Karonen SL, Standertskjöld-Nordenstam CG. Level of Plasma Prekallikrein and its Inhibitors in Reactors and Nonreactors during Intravenous Enhancement with Contrast Media. Acta Radiol 2016. [DOI: 10.1177/028418519203300418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Complex contact activation systems may play a major role in the side effects of i.v. contrast media (CM). This is why quantitative measurements of several factors (plasma prekallikrein, hematocrit (hct), α-2-macroglobulin, α-1-antitrypsin, and C1-esterase inhibitor) were determined prior to and following the injection of CM during body CT examination in 5 patient groups, each (n = 10) receiving one of 5 different CM, including ioxaglate, meglumine iodamide, metrizamide, iohexol, and meglumine diatrizoate. The initial plasma prekallikrein level was available from 45 patients and was statistically lower in reactors (mean 90.6 μmol TAMe/ml/h; n = 13) than in nonreactors (mean 107 μmol TAMe/ml/h; n = 32) (p = 0.006), but there was no statistically significant difference in the decrease of plasma prekallikrein before and at 5 min after the injection for those 2 groups. The initial plasma C1-esterase inhibitor level was lower in reactors, while the plasma α-2-macroglobulin level was higher in that group than in nonreactors. The results indicate that the measurement of plasma prekallikrein combined with plasma C1-esterase inhibitor and α-2-macroglobulin measurement could be useful when predicting which patients are prone to CM reactions.
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16
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Kekäläinen E, Pöntynen N, Meri S, Arstila TP, Jarva H. Autoimmunity, Not a Developmental Defect, is the Cause for Subfertility of Autoimmune Regulator (Aire) Deficient Mice. Scand J Immunol 2015; 81:298-304. [PMID: 25689230 DOI: 10.1111/sji.12280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 01/24/2015] [Indexed: 01/26/2023]
Abstract
Autoimmune regulator's (AIRE) best characterized role is in the generation immunological tolerance, but it is also involved in many other processes such as spermatogenesis. Loss-of-function mutations in AIRE cause a disease called autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy (APECED; also called autoimmune polyendocrinopathy syndrome type 1, APS-1) that is dominated by various autoimmune manifestations, mainly endocrinopathies. Both patients with APECED and Aire(-/-) mice suffer from varying levels of infertility, but it is not clear if it is a result of an autoimmune tissue damage or more of a developmental defect. In this study, we wanted to resolve whether or not the reduced fertility of Aire(-/-) mice is dependent on the adaptive immune system and therefore a manifestation of autoimmunity in these mice. We generated lymphopenic mice without Aire expression that were devoid of the autoimmune manifestations previously reported in immunocompetent Aire(-/-) mice. These Aire(-/-) Rag1(-/-) mice regained full fertility. This confirms that the development of infertility in Aire(-/-) mice requires a functional adaptive immune system. We also show that only the male Aire(-/-) mice are subfertile, whereas Aire(-/-) females produce litters normally. Moreover, the male subfertility can be adoptively transferred with lymphocytes from Aire(-/-) donor mice to previously fertile lymphopenic Aire(-/-) recipients. Our data show that subfertility in Aire(-/-) mice is dependent on a functional adaptive immune system thus confirming its autoimmune aetiology.
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Affiliation(s)
- E Kekäläinen
- Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki, Helsinki, Finland
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17
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Liszewski M, Kolev M, Le Friec G, Leung M, Bertram P, Pickering M, Drouet C, Meri S, Arstila T, Pekkarinen P, Reinheckel T, Cordoba SRD, Afzali B, Atkinson J, Kemper C. Evidence for intracellular complement activation vital to Th1 immunity. Mol Immunol 2013. [DOI: 10.1016/j.molimm.2013.05.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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18
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Meri T, Amdahl H, Lehtinen MJ, Hyvärinen S, McDowell JV, Bhattacharjee A, Meri S, Marconi R, Goldman A, Jokiranta TS. Microbes bind complement inhibitor factor H via a common site. PLoS Pathog 2013; 9:e1003308. [PMID: 23637600 PMCID: PMC3630169 DOI: 10.1371/journal.ppat.1003308] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 03/02/2013] [Indexed: 11/18/2022] Open
Abstract
To cause infections microbes need to evade host defense systems, one of these being the evolutionarily old and important arm of innate immunity, the alternative pathway of complement. It can attack all kinds of targets and is tightly controlled in plasma and on host cells by plasma complement regulator factor H (FH). FH binds simultaneously to host cell surface structures such as heparin or glycosaminoglycans via domain 20 and to the main complement opsonin C3b via domain 19. Many pathogenic microbes protect themselves from complement by recruiting host FH. We analyzed how and why different microbes bind FH via domains 19–20 (FH19-20). We used a selection of FH19-20 point mutants to reveal the binding sites of several microbial proteins and whole microbes (Haemophilus influenzae, Bordetella pertussis, Pseudomonas aeruginosa, Streptococcus pneumonia, Candida albicans, Borrelia burgdorferi, and Borrelia hermsii). We show that all studied microbes use the same binding region located on one side of domain 20. Binding of FH to the microbial proteins was inhibited with heparin showing that the common microbial binding site overlaps with the heparin site needed for efficient binding of FH to host cells. Surprisingly, the microbial proteins enhanced binding of FH19-20 to C3b and down-regulation of complement activation. We show that this is caused by formation of a tripartite complex between the microbial protein, FH, and C3b. In this study we reveal that seven microbes representing different phyla utilize a common binding site on the domain 20 of FH for complement evasion. Binding via this site not only mimics the glycosaminoglycans of the host cells, but also enhances function of FH on the microbial surfaces via the novel mechanism of tripartite complex formation. This is a unique example of convergent evolution resulting in enhanced immune evasion of important pathogens via utilization of a “superevasion site.” Complement is an important arm of innate immunity. Activation of this plasma protein cascade leads to opsonization of targets for phagocytosis, direct lysis of Gram-negative bacteria, and enhancement of the inflammatory and acquired immune responses. No specific signal is needed for activation of the alternative pathway of complement, leading to its activation on all unprotected surfaces. Pathogenic microbes need to evade this pathway, and several species are known to recruit host complement inhibitor factor H (FH) to prevent the activation. FH is important for protection of host cells, too, as defects in FH lead to a severe autoreactive disease, atypical hemolytic uremic syndrome. We have now identified at the molecular level a common mechanism by which seven different microbes, Haemophilus influenzae, Bordetella pertussis, Pseudomonas aeruginosa, Streptococcus pneumoniae, Candida albicans, Borrelia burgdorferi and B. hermsii, recruit FH. All microbes bind FH via a common site on domain 20, which facilitates formation of a tripartite complex between the microbial protein, the main complement opsonin C3b, and FH. We show that, by utilizing the common microbial binding site on FH20, microbes can inhibit complement more efficiently. This detailed knowledge on mechanism of complement evasion can be used in developing novel antimicrobial chemotherapy.
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Affiliation(s)
- T Meri
- Haartman Institute, Department of Bacteriology and Immunology and Immunobiology Research Program, University of Helsinki, Helsinki, Finland.
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Khattab A, Kremsner P, Meri S. Complement activation in primiparous women from a malaria endemic area is associated with reduced birthweight. Placenta 2013; 34:162-7. [DOI: 10.1016/j.placenta.2012.11.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 11/22/2012] [Accepted: 11/22/2012] [Indexed: 10/27/2022]
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20
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Myhr KM, Sadallah S, Mollnes TE, Meri S, Nyland HI, Schifferli J, Vedeler CA. Interferon-α2a effects on complement activation and regulation in MS patients. Acta Neurol Scand 2012. [DOI: 10.1034/j.1600-0404.2000.00013.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Kajander T, Lehtinen M, Hyvärinen S, Bhattacharjee A, Meri T, Kolodziejczyk R, Meri S, Jokiranta S, Goldman A. Factor H ligand complexes – structural studies on complement regulation and disease. Acta Crystallogr A 2012. [DOI: 10.1107/s0108767312099357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
Properdin deficiency is a rare immunological disorder inherited as an X-chromosomal recessive trait. Properdin deficiency poses a significant risk for severe meningococcal infections. About 20 mutations have been reported to underlie properdin deficiency. Here we report a large Finnish family with a novel mutation in the properdin gene (CFP). Based on the total absence of properdin activity in a 14-year-old male patient with an infection resembling meningococcal bacteraemia, the coding region and splice sites of the gene were sequenced. The mutation is located in exon 9 and changes guanine to adenine at nucleotide 1164 (c.1164G>A) that causes tryptophan to change to a premature stop codon (W388X). The mother of the patient was shown to be a carrier of the mutation. In total, the mutation was identified in six females and three young males in the family. The mutation must be inherited from the grandfather who had died of an unknown infectious disease. This is the first mutation of the properdin gene identified in Finland.
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Affiliation(s)
- M Helminen
- Department of Pediatrics, Tampere University Hospital, University of Tampere, Tampere, Finland.
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23
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Abstract
Doberman hepatitis (DH) is associated with homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 indicating a role for the immune system in the development of the disease. The dog leucocyte antigen (DLA) class II expression is controlled at the transcriptional level with proximal promoters. Differential expression of DLA class II molecules of antigen-presenting cells is reported to affect susceptibility to or protection from different immune-mediated diseases. The aim of this study was to evaluate, whether the variation in promoter areas of homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 Dobermans could explain why some dogs become afflicted with DH and others do not. Our findings suggest that promoter variants are not associated as risk modifiers in homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 Dobermans, but additional factors are needed. Nevertheless, our study indicates that the whole DLA block is associated to the disease.
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Affiliation(s)
- H Dyggve
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
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Outinen TK, Mäkelä S, Huhtala H, Hurme M, Meri S, Pörsti I, Sane J, Vaheri A, Syrjänen J, Mustonen J. High pentraxin-3 plasma levels associate with thrombocytopenia in acute Puumala hantavirus-induced nephropathia epidemica. Eur J Clin Microbiol Infect Dis 2011; 31:957-63. [PMID: 21901638 DOI: 10.1007/s10096-011-1392-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 08/18/2011] [Indexed: 12/18/2022]
Abstract
Our aim was to investigate whether plasma levels of the long pentraxin-3 (PTX3) associate with the severity of Puumala hantavirus-induced nephropathia epidemica (NE). Sixty-one prospectively identified consecutively hospitalized NE patients were examined. Plasma PTX3, interleukin (IL)-6, terminal complement complex SC5b-9, complement component C3, C-reactive protein (CRP), creatinine, sodium, kynurenine, and tryptophan levels, as well as the blood cell count, were determined for up to five consecutive days after hospitalization. Receiver operating characteristic (ROC) analysis revealed that the maximum PTX3 level >101.6 ng/ml (high PTX3) showed a sensitivity of 71% and a specificity of 89% for detecting platelet level <50 × 10(9)/l, with an area under the curve (AUC) value of 0.78 (95% confidence interval [CI] 0.63-0.94). High PTX3 level was also associated with several other variables reflecting the severity of the disease: patients with high PTX3 level had higher maximum blood leukocyte (16.1 vs. 9.7 × 10(9)/l, p < 0.001), plasma IL-6 (16.9 vs. 9.0 pg/ml, p = 0.007), and creatinine (282 vs. 124 μmol/l, p = 0.007) levels than patients with low maximum PTX3 level. They also had longer hospital stays (8 vs. 5 days, p = 0.015) compared to patients with low PTX3 level. High plasma PTX3 levels are associated with thrombocytopenia and the overall severity of NE.
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Affiliation(s)
- T K Outinen
- Department of Internal Medicine, Tampere University Hospital, P.O. Box 2000, 33521, Tampere, Finland.
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Reichhardt M, Loimaranta V, Thiel S, Meri S, Jarva H. The complement regulating properties of gp340 – A new inhibitor of the lectin pathway. Mol Immunol 2011. [DOI: 10.1016/j.molimm.2011.06.344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Ho D, Riva R, Rybak M, Kasanen T, Blom A, Skurnik M, Meri S. Binding of C4b binding protein to Yersinia pseudotuberculosis Ail. Mol Immunol 2011. [DOI: 10.1016/j.molimm.2011.06.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Haapasalo-Tuomainen K, Vuopio J, Syrjänen J, Suvilehto J, Massinen S, Karppelin M, Järvelä I, Meri S, Kere J, Jokiranta T. AMD-associated complement factor H variant Y402H protects from streptococcal infections—Evidence from bacterial in vitro survival and human genetic association studies. Mol Immunol 2011. [DOI: 10.1016/j.molimm.2011.06.324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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Bhattacharjee A, Meri T, Kajander T, Lehtinen M, Hyvarinen S, Kolodziejczyk R, Meri S, Goldman A, Jokiranta T. The structure of factor H domains 19–20 in complex with C3d explains regulation of alternative pathway amplification on self and pathogen surfaces. Mol Immunol 2011. [DOI: 10.1016/j.molimm.2011.06.244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kekäläinen E, Lehto MK, Smeds E, Miettinen A, Meri S, Jarva H, Arstila TP. Defective central tolerance in Aire-deficient mice is not sufficient to induce symptomatic autoimmunity during lymphopenia-induced T cell proliferation. Scand J Immunol 2011; 74:71-9. [PMID: 21352256 DOI: 10.1111/j.1365-3083.2011.02543.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Transcriptional regulator autoimmune regulator (AIRE) controls thymic negative selection but it is also expressed in secondary lymphoid organs. The relative contribution of AIRE's central and peripheral function to the maintenance of tolerance is unclear. We transferred mature lymphocytes from Aire(-/-) or wild-type donors to Aire(+/+) lymphopenic recipients, which allowed us to gauge the autoreactivity inherent in the cells originating in an Aire(-/-) thymus. In the ensuing lymphopenia-induced proliferation (LIP), the recipients of cells from Aire(-/-) showed definite T cell hyperproliferation and developed autoantibodies at a higher frequency than the recipients of wild-type cells. However, neither of the recipient groups developed clinical symptoms, and pathological tissue infiltrates were also absent. The recipients of Aire(-/-) cells showed hyperproliferation and increased accumulation of regulatory T cells (Tregs), especially in tissues susceptible to inflammation triggered by LIP. These data are consistent with the view that T cells developing in the absence of Aire are autoreactive. However, overt autoimmunity was prevented, most likely by the suppressive function of Treg cells in the Aire-sufficient recipients. Our results support the importance of the peripheral AIRE expression in the maintenance of immunological tolerance.
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Affiliation(s)
- E Kekäläinen
- Department of Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland.
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Dyggve H, Kennedy LJ, Meri S, Spillmann T, Lohi H, Speeti M. Association of Doberman hepatitis to canine major histocompatibility complex II. ACTA ACUST UNITED AC 2010; 77:30-5. [PMID: 20946186 DOI: 10.1111/j.1399-0039.2010.01575.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Doberman hepatitis (DH) is a chronic and progressive inflammatory liver disease that mainly affects female dogs. The high incidence of chronic hepatitis in Dobermans is suggestive of a genetic predisposition. DH is characterized by mononuclear cell infiltration and copper accumulation in the liver and major histocompatibility complex (MHC) class II antigen expression in the hepatocytes. In dogs, the MHC is referred to as the dog leukocyte antigen (DLA) system. In this study, the potential role of DLA genes in DH was investigated by sequence-based typing in the exon 2 of DLA-DRB1, -DQA1 and -DQB1. The case group comprised 37 Dobermans with subclinical or clinical DH. The control group consisted of 37 healthy Dobermans, with normal liver enzyme values and without immunosuppressive medication. The control dogs were over 10 years old to include dogs with the lowest genetic risk of DH. Our results indicate that Dobermans with homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 [odds ratio (OR) = 14.9, confidence limit (CL) = 3.1-71.7, P < 0.00005], especially with homozygosity for DLA-DRB1*00601 (P < 0.0005), are susceptible to DH. The DQ heterodimer DLA-DQA1*00901/DQB1*00101 and the allele DLA-DRB1*01501 appear to confer protection against DH (P < 0.001). Allele and haplotype frequencies were compared using chi-squared statistics. The disease shows a complex pattern of inheritance, but the observed DLA class II association with DH suggests a role for the immune system in the development of the disease.
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Affiliation(s)
- H Dyggve
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
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31
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Sane J, Mäkelä S, Meri S, Vaheri A, Vapalahti O, Mustonen J. The clinical severity of Puumala hantavirus-induced nephropathia epidemica and partial complement protein C4 deficiencies. Int J Infect Dis 2010. [DOI: 10.1016/j.ijid.2010.02.654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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32
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Peltonen S, Kari O, Jarva H, Mussalo-Rauhamaa H, Haahtela T, Meri S. Complement activation in tear fluid during occupational mold challenge. Ocul Immunol Inflamm 2009; 16:224-9. [PMID: 19065417 DOI: 10.1080/09273940802283323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Indoor air quality is important in occupational healthcare when evaluating the health risks of a work environment. Components of the classical and alternative complement pathways are present in ocular tissues and fluids. The authors determined the levels of complement components C1INH, C3, and C4 in sera and C3a in tear fluids of normal persons and of those who were exposed to molds. METHODS Nine patients environmentally exposed to molds and 6 controls were selected from the Indoor Air Clinic of the Skin and Allergy Hospital. Tear fluid samples were collected from patients during the exposure to molds and after 2 weeks without mold exposure. At the same time, conjunctival cytology samples were obtained from each patient. Tear fluid was taken from 6 control subjects. All had negative skin prick tests to common environmental allergens. RESULTS In 4 patients subjective eye symptoms and tear fluid C3a levels decreased during 2 weeks of sick leave as did conjunctival eosinophils but other inflammatory cells were unchanged. CONCLUSION Elevated complement C3a levels in tear fluids may be influenced by environmental exposure to molds. According to the authors' clinical experience, eosinophilia is not a consistent finding in patients exposed to molds. However, molds may cause eosinophilic inflammation in the eye.
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Affiliation(s)
- S Peltonen
- Skin and Allergy Hospital, Helsinki University Central Hospital, Helsinki, Finland
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Kaare M, Seitsonen S, Jarvela I, Meri S, Laivuori H. Complement factor H variant Y402H is not a risk factor for preeclampsia in the Finnish population. Hypertens Pregnancy 2009; 27:328-36. [PMID: 19003634 DOI: 10.1080/10641950801955691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Variations in complement factor H, which down-regulates the activity of the alternative complement pathway, have been associated with different vascular disorders. Here we examine whether factor H variation is involved in the etiology of preeclampsia. METHODS We studied 110 women with preeclampsia and 99 controls for complement factor H variations by sequencing. RESULTS No significant differences in the genotype or allele frequencies of the Y402H variant were detected between the two groups. No sequence variations were detected in the short consensus repeat domain 20 of the gene. CONCLUSIONS Neither the Y402H variant, nor mutations in the short consensus repeat domain 20 of the gene is associated with preeclampsia. For examination of possible links to other polymorphisms or detection of small genotypic effects, studies in larger sample sets are warranted.
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Affiliation(s)
- M Kaare
- Folkhälsan Institute of Genetics, University of Helsinki, Finland.
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Abstract
The chimeric anti-CD20 monoclonal antibody rituximab has been used for the treatment of non-Hodgkin's lymphomas with varying responses. Rituximab has been demonstrated to act by direct complement-dependent cytotoxity (CDC) and by inducing apoptosis, complement-, and antibody-dependent cellular cytotoxity. In the present study, we determined whether rituximab's effector mechanisms differed between two human follicular lymphoma cell lines that originate from different maturation stages of B cell germinal centre (GC) development. The tested HF-1 and HF-4b lymphoma cells represent GC centrocytes and centroblasts, respectively. Both cell lines responded to rituximab treatment by undergoing apoptosis yet the HF-1 cells were more sensitive. A major difference was seen in the proliferation response as only the proliferation of HF-1 cells was inhibited by rituximab. In the presence of normal human serum (NHS) rituximab almost completely inhibited DNA synthesis and induced necrosis of both cell lines because of CDC. Our results show that the CD20-positive HF-1 and HF-4b cells respond differentially to rituximab-induced apoptosis and inhibition of proliferation but similarly to complement-mediated killing. The increased sensitivity of the HF-1 cell line to apoptosis and inhibition of proliferation may reflect a tendency of centrocytic cells for negative selection and a role for CD20 in this process.
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Affiliation(s)
- A M Mattila
- Department of Bacteriology and Immunology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
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Seitsonen SP, Jarvela IE, Meri S, Tommila PV, Ranta PH, Immonen IJ. The effect of complement factor H Y402H polymorphism on the outcome of photodynamic therapy in age-related macular degeneration. Eur J Ophthalmol 2008; 17:943-9. [PMID: 18050121 DOI: 10.1177/112067210701700612] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Photodynamic therapy (PDT) has been widely used in the treatment of age-related macular degeneration (AMD). The complement cascade has an important role in the tissue reactions occurring after PDT. The Y402H polymorphism of the complement factor H (CFH) gene has been identified as a risk factor for AMD. Since CFH is central in the regulation of the complement system the authors wanted to analyze whether the CFH Y402H polymorphism modifies the PDT outcome in AMD. METHODS A total of 88 patients having been treated with PDT and without further scheduled PDT sessions were analyzed. Depending on the situation at their final PDT session the patients were classified retrospectively as PDT-responders or PDT-nonresponders. All patients were genotyped for the CFH Y402H polymorphism. RESULTS The proportion of PDT-responders was 18/26 (69.2%) in patients homozygous for the CFH Y402H risk allele, 34/50 (68.0%) in heterozygous, and 7/12 (58.3%) in patients with the normal genotype (p=0.520). The median number of PDT treatments of the PDT-responders was three for all the genotypes. CONCLUSIONS The dysfunction of the CFH related to the risk of AMD and caused by the Y402H polymorphism does not modify the outcome of PDT. Genotyping for CFH Y402H cannot be used to select patients for this treatment.
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Affiliation(s)
- S P Seitsonen
- Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.
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36
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Jalanko H, Peltonen S, Koskinen A, Puntila J, Isoniemi H, Holmberg C, Pinomäki A, Armstrong E, Koivusalo A, Tukiainen E, Mäkisalo H, Saland J, Remuzzi G, de Cordoba S, Lassila R, Meri S, Jokiranta TS. Successful liver-kidney transplantation in two children with aHUS caused by a mutation in complement factor H. Am J Transplant 2008; 8:216-21. [PMID: 17973958 DOI: 10.1111/j.1600-6143.2007.02029.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A 12-month-old boy and his 16-year-old aunt became acutely ill 6 months apart and were diagnosed to have atypical hemolytic uremic syndrome (aHUS). Genetic analysis revealed heterozygous R1215Q mutation in complement factor H (CFH) in both patients. The same mutation was found in five healthy adult relatives indicating incomplete penetrance of the disease. The patients developed terminal renal failure and experienced reversible neurological symptoms in spite of plasma exchange (PE) therapy. In both cases, liver-kidney transplantation was successfully performed 6 months after the onset of the disease. To minimize complement activation and prevent thrombotic microangiopathy or overt thrombotic events due to the malfunctioning CFH, extensive PE with fresh frozen plasma was performed pre- and perioperatively and anticoagulation was started a few hours after the operation. No circulatory complications appeared and all four grafts started to function immediately. Also, no recurrence or other major clinical setbacks have appeared during the postoperative follow-up (15 and 9 months) and the grafts show excellent function. While more experience is needed, it seems that liver-kidney transplantation combined with pre- and perioperative PE is a rational option in the management of patients with aHUS caused by CFH mutation.
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Affiliation(s)
- H Jalanko
- Hospital for Children and Adolescents, Helsinki, Finland
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Seppänen M, Lokki ML, Notkola IL, Mattila K, Valtonen V, Nieminen A, Vesanen M, Asikainen S, Meri S. Complement and c4 null alleles in severe chronic adult periodontitis. Scand J Immunol 2007; 65:176-81. [PMID: 17257223 DOI: 10.1111/j.1365-3083.2006.01886.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Severe forms of chronic periodontitis affect up to 10% of adults. Tumour necrosis factor and lymphotoxin-alpha genes in the major histocompatibility complex are associated with severe periodontitis. Complement factor C4 is a nearby, polymorphic, functionally relevant gene region. Although associated with chronic mucosal infections, C4 deficiencies have not been assessed in adult periodontitis patients. We tested whether complement levels are systemically altered and C4 deficiencies associated with severe chronic periodontitis. In a case-control study, we analysed levels of plasma C3, and C4, serum classical pathway haemolytic activity, C4 allotypes and C4 gene numbers in 37 patients with severe chronic periodontitis and in 150 voluntary controls. Plasma levels of C3 were higher, and classical pathway haemolytic activity was lower in patients than in controls. Partial C4 gene deficiencies were more frequent in patients than in controls (odds ratio 2.4, 95% confidence interval 1.1-5.5, P = 0.032). Changes in complement levels may reflect chronic, recurring inflammation. C4 gene deficiencies are associated with predisposition to chronic periodontitis.
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Affiliation(s)
- M Seppänen
- Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Hospital District of Helsinki and Uusimaa (HUS), Helsinki, Finland.
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Abstract
Intravascular Schistosoma mansoni worms seem to take up immunoglobulins from blood by surface Fc-receptors, but the process whereby bound immunoglobulins are processed by the parasite is poorly understood. We here present morphological data suggesting that two distinct main processes are involved: Host immunoglobulins were seen at two distinct locations in the parasite: in the frontal part of the enteric tube, the oesophagus, and as a fine granular staining at the surface and in the subtegumental region. The latter staining pattern corresponds to host immunoglobulin localization in discrete organelle-like aggregates tentatively identified as 'discoid or elongate bodies' at the ultrastructural level using immunogold staining. Immunoglobulin uptake by intravascular worms was also demonstrated in vivo after passive administration of 125I-labelled rabbit and mouse immunoglobulins. Radiolabelled immunoglobulins were taken up by the worms and shown to localize as fine strands running perpendicular to the parasite surface. Our results suggest that intravascular schistosomes take up host immunoglobulins both as part of their enteric digestion and by a surface Fc-receptor-mediated mechanism, involving transport and processing within organelles, 'elongate bodies'. Immunoglobulins taken up by intravascular schistosomes form a distinct organelle-like granules, which seem to be processed within the excretory system of the parasite.
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Affiliation(s)
- C Thors
- Swedish Institute for Infectious Disease Control (SMI), Solna, Sweden
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39
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Seppänen M, Suvilehto J, Lokki ML, Notkola IL, Järvinen A, Jarva H, Seppälä I, Tahkokallio O, Malmberg H, Meri S, Valtonen V. Immunoglobulins and complement factor C4 in adult rhinosinusitis. Clin Exp Immunol 2006; 145:219-27. [PMID: 16879240 PMCID: PMC1809671 DOI: 10.1111/j.1365-2249.2006.03134.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We assessed whether complement and its factor C4 or abnormal immunoglobulin levels are associated with chronic or recurrent rhinosinusitis. We used multiple patient and control groups to obtain clinically meaningful data. Adult chronic or recurrent rhinosinusitis and acute purulent rhinosinusitis patients were compared with unselected adults and controls without previous rhinosinusitis. Associated clinical factors were reviewed. Levels of immunoglobulins, plasma C3, C4 and classical pathway haemolytic activity were analysed. C4 immunophenotyping was used to detect C4A and C4B deficiencies as null alleles. Complement was up-regulated in rhinosinusitis. C4A nulls and low IgA, IgG, IgG1, IgG2, IgG3 and IgG4 levels were all more common in chronic or recurrent rhinosinusitis patients than in unselected and healthy controls. We searched for relevant differences between the patient groups. According to stepwise logistic regression analysis, nasal polyposis [odds ratio (OR) 10.64, 95% confidence interval (CI) 2.5-45.7, P = 0.001], bronchial asthma (OR 8.87, 95% CI 2.3-34.9, P = 0.002), C4A null alleles (OR 5.84, 95% CI 1.4-24.9, P = 0.017) and low levels of IgG4 together with either IgG1 or IgG2 (OR 15.25, 95% CI 1.4-166.8, P = 0.026) were more common in chronic or recurrent rhinosinusitis than in acute rhinosinusitis patients. Isolated low IgG subclasses had limited value in patient assessment. C4A null alleles are associated with chronic or recurrent rhinosinusitis, potentially through their effect on immune defence and inflammation control. Multiple clinical and immunological parameters may need to be evaluated when searching for prognostic variables.
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Affiliation(s)
- M Seppänen
- Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Hospital District of Helsinki and Uusimaa, PO Box 348, FI-00029 HUS, Helsinki, Finland.
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40
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Meri T, Cutler SJ, Blom AM, Meri S, Jokiranta TS. Relapsing fever spirochetes Borrelia recurrentis and B. duttonii acquire complement regulators C4b-binding protein and factor H. Infect Immun 2006; 74:4157-63. [PMID: 16790790 PMCID: PMC1489703 DOI: 10.1128/iai.00007-06] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Relapsing fever is a rapidly progressive and severe septic disease caused by certain Borrelia spirochetes. The disease is divided into two forms, i.e., epidemic relapsing fever, caused by Borrelia recurrentis and transmitted by lice, and the endemic form, caused by several Borrelia species, such as B. duttonii, and transmitted by soft-bodied ticks. The spirochetes enter the bloodstream by the vector bite and live persistently in plasma even after the development of specific antibodies. This leads to fever relapses and high mortality and clearly indicates that the Borrelia organisms utilize effective immune evasion strategies. In this study, we show that the epidemic relapsing fever pathogen B. recurrentis and an endemic relapsing fever pathogen, B. duttonii, are serum resistant, i.e., resistant to complement in vitro. They acquire the host alternative complement pathway regulator factor H on their surfaces in a similar way to that of the less serum-resistant Lyme disease pathogen, B. burgdorferi sensu stricto. More importantly, the relapsing fever spirochetes specifically bind host C4b-binding protein, a major regulator of the antibody-mediated classical complement pathway. Both complement regulators retained their functional activities when bound to the surfaces of the spirochetes. In conclusion, this is the first report of complement evasion by Borrelia recurrentis and B. duttonii and the first report showing capture of C4b-binding protein by spirochetes.
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Affiliation(s)
- T Meri
- Haartman Institute, Department of Bacteriology and Immunology, P.O. Box 21, University of Helsinki, FIN-00014 Helsinki, Finland.
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41
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Lavikainen A, Lehtinen MJ, Laaksonen S, Agren E, Oksanen A, Meri S. Molecular characterization of Echinococcus isolates of cervid origin from Finland and Sweden. Parasitology 2006; 133:565-70. [PMID: 16834793 DOI: 10.1017/s0031182006000667] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 05/11/2006] [Accepted: 05/11/2006] [Indexed: 11/07/2022]
Abstract
The species Echinococcus granulosus is made up of several genotypic strain groups, whose taxonomical classification is still undetermined. Genotypes in the cervid-wolf life-cycle are poorly known, especially in Europe. In this study, 33 Echinococcus isolates from cervids from Finland and Sweden were characterized using mitochondrial ND1 gene sequencing. In addition, phylogenetic analysis of E. granulosus strains using the mitochondrial ATP6, ND1, ND3 and CO1 genes was performed using maximum likelihood, neighbour-joining and maximum parsimony methods. The Finnish and Swedish cervid isolates were found to represent the genotype G10. In the phylogenetic analyses, the camel (G6), pig (G7), cervid (G8) and Fennoscandian cervid (G10) strains clustered in a well-supported monophyletic group. This group differed clearly from the common sheep (G1) and horse (G4, 'E. equinus') strains, but was closely related to the cattle strain (G5, 'E. ortleppi'). Our results support the previous studies suggesting that the genotypes G6-10 should be separated from the species E. granulosus sensu stricto. However, additional morphological studies are needed, and the relationship to the cattle strain ('E. ortleppi') should be thoroughly evaluated before a final decision of the taxonomical status of the G6-10 group can be made.
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Affiliation(s)
- A Lavikainen
- Department of Bacteriology and Immunology (FINPAR), Haartman Institute, P.O. Box 21, FIN-00014, University of Helsinki, Finland.
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Oppermann M, Manuelian T, Józsi M, Brandt E, Jokiranta TS, Heinen S, Meri S, Skerka C, Götze O, Zipfel PF. The C-terminus of complement regulator Factor H mediates target recognition: evidence for a compact conformation of the native protein. Clin Exp Immunol 2006; 144:342-52. [PMID: 16634809 PMCID: PMC1809651 DOI: 10.1111/j.1365-2249.2006.03071.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The complement inhibitor Factor H has three distinct binding sites for C3b and for heparin, but in solution uses specifically the most C-terminal domain, i.e. short consensus repeats (SCR) 20 for ligand interaction. Two novel monoclonal antibodies (mABs C14 and C18) that bind to the most C-terminal domain SCR 20 completely blocked interaction of Factor H with the ligands C3b, C3d, heparin and binding to endothelial cells. In contrast, several mAbs that bind to the N-terminus and to the middle regions of the molecule showed no or minor inhibitory effects when assayed by enzyme-linked immunosorbent assay (ELISA) and ligand interaction assays. This paradox between a single functional binding site identified for native Factor H versus multiple interaction sites reported for deletion constructs is explained by a compact conformation of the fluid phase protein with one accessible binding site. On zymosan particles mAbs C14 and C18 blocked alternative pathway activation completely. Thus demonstrating that native Factor H makes the first and initial contact with the C terminus, which is followed by N terminally mediated complement regulation. These results are explained by a conformational hypothetical model: the native Factor H protein has a compact structure and only one binding site accessible. Upon the first contact the protein unfolds and exposes the additional binding sites. This model does explain how Factor H mediates recognition functions during complement control and the clustering of disease associated mutations in patients with haemolytic uraemic syndrome that have been reported in the C-terminal recognition domain of Factor H.
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Affiliation(s)
- M Oppermann
- Department of Immunology, University of Göttingen, Göttingen, Germany
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43
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Abstract
Ovarian cancer is potentially well suited for local monoclonal antibody (mAb) immunotherapy, because it remains within the peritoneal cavity for a long period of time before giving rise to distant metastases. At the stage of minimal residual disease, the cells appear to be in a state of dormancy (G(0)) or at least have lower rates of tumour cell proliferation. They should be a promising target for immunotherapy. Here we first examined the cell-cycle expression of CD59 and decay-accelerating factor (DAF; CD55) on four different ovarian carcinoma cell lines, using simultaneous flow cytometric analysis of DNA content or the cell-cycle-specific nuclear proliferation protein Ki67 and CD59 or DAF surface expression. We found that CD59 and DAF are stably expressed throughout the cell cycle. The polyvalent approach to target-independent antigens to improve the efficiency of mAb complement (C)-mediated damages was promising, and tumour cells become sensitive to C damage, when incubated with cross-linked mAb against different tumour-associated antigens. Although, such immune complex-mediated C activation was rather ineffective in killing the cells, it could be potentiated by the addition of blocking mAb against CD59 and DAF. Our results suggest that the activities of intrinsic C regulators must be neutralized to make minimal residual disease a promising target for antibody therapy.
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Affiliation(s)
- L Bjørge
- Department of Obstetrics and Gynecology, Institute of Clinical Medicine, Haukeland University Hospital, Bergen, Norway.
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44
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Abstract
Ovarian cancer spreads intraperitoneally and forms fluid, whereby the diagnosis and therapy often become delayed. As the complement (C) system may provide a cytotoxic effector arm for both immunological surveillance and mAb-therapy, we have characterised the C system in the intraperitoneal ascitic fluid (AF) from ovarian cancer patients. Most of the AF samples showed alternative and classical pathway haemolytic activity. The levels of C3 and C4 were similar to or in the lower normal range when compared to values in normal sera, respectively. However, elevated levels of C3a and soluble C5b-9 suggested C activation in vivo. Malignant cells isolated from the AF samples had surface deposits of C1q and C3 activation products, but not of C5b-9 (the membrane attack complex; MAC). Activation could have become initiated by anti-tumour cell antibodies that were detected in the AFs and/or by changes on tumour cell surfaces. The lack of MAC was probably due to the expression of C membrane regulators CD46, CD55 and CD59 on the tumour cells. Soluble forms of C1 inhibitor, CD59 and CD46, and the alternative pathway inhibitors factor H and FHL-1 were present in the AF at concentrations higher than in serum samples. Despite the presence of soluble C inhibitors it was possible to use AF as a C source in antibody-initiated killing of ovarian carcinoma cells. These results demonstrate that although the ovarian ascitic C system fails as an effective immunological surveillance mechanism, it could be utilised as an effector mechanism in therapy with intraperitoneally administrated mAbs, especially if the intrinsic C regulators are neutralised.
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Affiliation(s)
- L Bjørge
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, FIN-00014 Helsinki, Finland.
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45
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Speeti M, Ståhls A, Meri S, Westermarck E. Corrigendum to “Upregulation of major histocompatibility complex class II antigens in hepatocytes in Doberman hepatitis” [Vet. Immunol. Immunopathol. 96 (1–2) (2004) 1–12]. Vet Immunol Immunopathol 2005. [DOI: 10.1016/j.vetimm.2004.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Meri T, Blom AM, Hartmann A, Lenk D, Meri S, Zipfel PF. The hyphal and yeast forms of Candida albicans bind the complement regulator C4b-binding protein. Infect Immun 2004; 72:6633-41. [PMID: 15501796 PMCID: PMC523010 DOI: 10.1128/iai.72.11.6633-6641.2004] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Candida albicans, an important pathogenic yeast, activates all three pathways of the complement system. To understand how this yeast evades the effects of the activated system, we have analyzed the binding of the classical pathway inhibitor C4b-binding protein (C4BP) by C. albicans. Purified native as well as recombinant C4BP bound dose dependently to the yeast and hyphal forms, as shown by multiple methods, such as confocal microscopy, flow cytometry, a novel enzyme-linked immunosorbent assay, absorption from human serum, and direct binding assays with purified proteins. A prominent binding site was identified at the tip of the germ tube, a structure that is considered important for tissue penetration and pathogenesis. The binding site in C4BP was localized to the two N-terminal complement control protein domains by using recombinant deletion constructs and site-specific monoclonal antibodies. As the alternative pathway inhibitors factor H and FHL-1 also bind to C. albicans, the binding of all three plasma proteins was compared. Simultaneous binding of the classical regulator C4BP and the alternative pathway regulator factor H was demonstrated by confocal microscopy. In addition, FHL-1 competed for binding with C4BP, suggesting that these two related complement regulators bind to the same structures on the yeast surface. The surface-attached C4BP maintains its complement regulatory activities and inactivates C4b. The surface-attached human C4BP serves multiple functions relevant for immune evasion and likely pathogenicity. It inhibits complement activation at the yeast surface and, in addition, mediates adhesion of C. albicans to host endothelial cells.
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Affiliation(s)
- T Meri
- Hans Knöll Institute for Natural Products Research, D-07745 Jena, Germany
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47
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Speeti M, Ståhls A, Meri S, Westermarck E. Upregulation of major histocompatibility complex class II antigens in hepatocytes in Doberman hepatitis. Vet Immunol Immunopathol 2003; 96:1-12. [PMID: 14522129 DOI: 10.1016/s0165-2427(03)00134-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Major histocompatibility complex (MHC) class II antigen expression in hepatocytes and its correlation with mononuclear cell infiltration into the liver were studied using immunohistochemical techniques in 38 Dobermans with Doberman hepatitis (DH). Liver biopsy samples were obtained from 18 dogs at the subclinical stage. Autopsy samples were taken from 6 DH dogs euthanized for a reason other than DH, from 14 dogs euthanized because of advanced liver failure and from 6 control Dobermans. Upon examination of the control liver samples, no expression of MHC class II antigens was detected in hepatocytes. By contrast, in 15 of the 18 DH biopsies (83%) and in all 20 DH autopsy liver samples, hepatocytes expressed MHC class II molecules. MHC class II expression was either cytoplasmic or membranous and occurred in conjunction with lymphocyte infiltration. A correlation between the inflammatory reaction and the expression of MHC class II in hepatocytes suggests that the aberrant expression of MHC class II in hepatocytes is induced by cytokines. Hepatocytes presenting a putative MHC class II molecule-associated autoantigen could thus become the target of an immune attack mediated by CD4+ T cells. In addition, corticosteroid treatment was observed to significantly decrease MHC class II expression in DH hepatocytes. Inappropriate MHC class II expression in hepatocytes and mononuclear cell infiltration are suggesting an autoimmune nature for chronic hepatitis in Dobermans.
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Affiliation(s)
- M Speeti
- Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, 00014 Helsinki, Finland.
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48
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Lavikainen A, Lehtinen MJ, Meri T, Hirvelä-Koski V, Meri S. Molecular genetic characterization of the Fennoscandian cervid strain, a new genotypic group (G10) of Echinococcus granulosus. Parasitology 2003; 127:207-15. [PMID: 12964823 DOI: 10.1017/s0031182003003780] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The northern biotype of Echinococcus granulosus occurs in North America and northern Eurasia in life-cycles involving cervids. Previously, cervid isolates of E. granulosus from North America have been characterized using molecular genetic techniques as the G8 genotype. In this study, 5 isolates of E. granulosus were collected from 4 reindeer and 1 moose in north-eastern Finland. DNA sequences within regions of mitochondrial cytochrome c oxidase I (COI) and NADH dehydrogenase I (NI)I) genes and the internal transcribed spacer 1 (ITS-1) fragment of the ribosomal DNA were analysed. The mitochondrial nucleotide sequences were identical in all isolates, but high sequence variation was found in the ITS-1 region. Mitochondrial and nuclear sequences of the Finnish cervid E. granulosus and the camel strain (G6) of E. granulosus resembled closely each other. According to phylogenetic analyses, the Finnish isolates have close relationships also with the pig (G7) and cattle (G5) strains. Although some similarities were found with the previously published North American cervid strain (G8), particularly in the NDI sequence and some of the ITS-1 clones, the Finnish E. granulosus form represents a distinct, previously undescribed genotype of E. granulosus. The novel genotype is hereby named as the Fennoscandian cervid strain (G10).
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Affiliation(s)
- A Lavikainen
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, P.O. Box 21, FIN-00014, University of Helsinki, Finland.
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Gelderman KA, Hakulinen J, Hagenaars M, Kuppen PJK, Meri S, Gorter A. Membrane-bound complement regulatory proteins inhibit complement activation by an immunotherapeutic mAb in a syngeneic rat colorectal cancer model. Mol Immunol 2003; 40:13-23. [PMID: 12909127 DOI: 10.1016/s0161-5890(03)00048-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
MAb-mediated immunotherapy offers a potential tool for destroying metastasizing colorectal tumor cells. Promising results have been obtained by using xenograft models. However, overexpression of membrane-bound complement regulatory proteins (mCRP) impedes complement-mediated destruction of tumor cells in vitro. mCRP operate in a species selective manner. Therefore a syngeneic animal model is needed to investigate the contribution of mCRP in mAb-mediated immunotherapy. Here we present a syngeneic rat colorectal carcinoma model, which fulfills the conditions necessary to investigate the effect of mCRP expression on mAb-mediated immunotherapy of metastases of solid tumors.CC531 rat colorectal cancer cells were injected subcapsularly into the liver of syngeneic WAG/Rij rats. Four mAb (MG1(IgG2a), MG2(IgG2a), MG3(IgG3) and MG4(2a)(IgG2a)) directed against CC531 cells, were tested for their complement activating abilities in vitro and tumor homing capacities in vivo. Only MG4(2a) was found to activate complement in vitro and home to the tumor cells in vivo. This mAb induced C3-deposition and C-mediated lysis of CC531 cells in vitro when the effects of the C-inhibitors Crry/p65 and CD59 were neutralized. This implies an important role for these mCRP in restricting the effector functions of tumor-associated mAb on these cells. Although C activation could be induced by MG4(2a) in situ on tumor tissue sections, no deposition of C3 could be found on the tumor cells positive for MG4(2a) in vivo. This suggests that complement activation in vivo was inhibited by mCRP. The results indicate the suitability of this syngeneic animal model for studying the effects of mAb immunotherapy. However, the effect of mCRP on tumor cells need to be overcome, e.g. by the use of mAb against tumor antigens and mCRP.
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Affiliation(s)
- K A Gelderman
- Department of Pathology, Leiden University Medical Center, L1-Q, Albinusdreef 2, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
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Friese MA, Manuelian T, Junnikkala S, Hellwage J, Meri S, Peter HH, Gordon DL, Eibel H, Zipfel PF. Release of endogenous anti-inflammatory complement regulators FHL-1 and factor H protects synovial fibroblasts during rheumatoid arthritis. Clin Exp Immunol 2003; 132:485-95. [PMID: 12780697 PMCID: PMC1808733 DOI: 10.1046/j.1365-2249.2003.02173.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Rheumatoid arthritis is a chronic inflammatory disease of unknown aetiology predominantly affecting cells and tissues of synovial joints. Here we show that the two important complement regulators FHL-1 and factor H play a protective anti-inflammatory role in rheumatoid arthritis. Expression analyses at the mRNA- and protein level show in vitro expression and secretion of both regulators by synovial fibroblasts derived from patients with rheumatoid arthritis. Similarly the two regulators are synthesized in vivo in diseased synovial tissue, and in particular synovial lining cells express high levels of FHL-1. The anti-inflammatory role of these regulators in rheumatoid arthritis is highlighted by their induction with IFN-gamma and dexamethasone, whilst the pro-inflammatory cytokine TNF-alpha had no effect. Transient transfection experiments with various FHL-1/factor H promoter-luciferase reporter constructs into cells of distinct origin show independent cell and tissue specific promoter regulated transcription of these two regulators. The inducible expression, specifically of FHL-1 has physiological consequences. By binding directly to surfaces the released proteins protect cells from inflammatory damage and complement-mediated cell lysis. This study shows a novel protective and anti-inflammatory role of the two important complement regulators FHL-1 and factor H in rheumatoid arthritis and suggests a disease controlling role of the two proteins.
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Affiliation(s)
- M A Friese
- Research Group of Biomolecular Medicine, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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