| 1. |
- Bengtsson, Anders, et al.
(author)
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Low production of reactive oxygen species in granulocytes is associated with organ damage in systemic lupus erythematosus
- 2014
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In: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 16:3
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Journal article (peer-reviewed)abstract
- Introduction: Polymorphonuclear leukocytes (PMN) are main effector cells in the acute immune response. While the specific role of PMN in systemic lupus erythematosus (SLE) and autoimmunity is still unclear, their importance in chronic inflammation is gaining more attention. Here we investigate aspects of function, bone marrow release and activation of PMN in patients with SLE. Methods: The following PMN functions and subsets were evaluated using flow cytometry; (a) production of reactive oxygen species (ROS) after ex vivo stimulation with phorbol 12-myristate 13-acetate (PMA) or Escherichia coli (E. coli); (b) capacity to phagocytose antibody-coated necrotic cell material; (c) PMN recently released from bone marrow, defined as percentage of CD10(-)D16(low) in peripheral blood, and (d) PMN activation markers; CD11b, CD62L and C5aR. Results: SLE patients (n = 92) showed lower ROS production compared with healthy controls (n = 38) after activation ex vivo. The ROS production was not associated with corticosteroid dose or other immunotherapies. PMA induced ROS production was significantly reduced in patients with severe disease. In contrast, neither ROS levels after E. coli activation, nor the capacity to phagocytose were associated with disease severity. This suggests that decreased ROS production after PMA activation is a sign of changed PMN behaviour rather than generally impaired functions. The CD10(-)CD16(low) phenotype constitute 2% of PMN in peripheral blood of SLE patients compared with 6.4% in controls, indicating a decreased release of PMN from the bone marrow in SLE. A decreased expression of C5aR on PMN was observed in SLE patients, pointing towards in vivo activation. Conclusions: Our results indicate that PMN from SLE patients have altered function, are partly activated and are released abnormally from bone marrow. The association between low ROS formation in PMN and disease severity is consistent with findings in other autoimmune diseases and might be considered as a risk factor.
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| 2. |
- Gulez, N., et al.
(author)
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Homozygosity For a Novel Mutation in the C1q C Chain Gene in a Turkish Family With Hereditary C1q Deficiency
- 2010
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In: Journal of Investigational Allergology & Clinical Immunology. - 1698-0808. ; 20:3, s. 255-258
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Journal article (peer-reviewed)abstract
- Hereditary complete deficiency of complement component C1q is associated with a high prevalence of systemic lupus erythematosus and increased susceptibility to severe recurrent infections. An 11-year-old girl was screened for immunodeficiency due to a history of recurrent meningitis and pneumonia. Immunologic studies revealed absence of classic pathway hemolytic activity and undetectable levels of C1q. Exon-specific amplification of genomic DNA by polymerase chain reaction followed by direct sequence analysis revealed a novel homozygous missense mutation at codon 48 in the C1q C gene causing a glycine-to-arginine substitution affecting the collagen-like region of C1q. No changes were seen in the exons of the A and B chains. The mutation affected both the formation and the secretion of C1q variant molecules. We describe a novel mutation in the C1q C chain gene that leads to an interchange in amino acids resulting in absence of C1q in serum.
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| 3. |
- Gullstrand, Birgitta
(author)
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Apoptosis of Peripheral Blood Leukocytes in Systemic Lupus Erythematosus: Studies on Serum Induction and Complement-Dependent Clearance Mechanisms
- 2010
-
Doctoral thesis (other academic/artistic)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disease involving many organ systems. The cause is not known, but a complex combination of environmental and genetic factors seems to be involved. In SLE upregulation of type I interferons, a hyperactive B-cell response, presence of autoantibodies against modified nuclear components, increased complement consumption, increased apoptosis and decreased clearance of apoptotic cells are seen. The purpose of this thesis was to investigate some of these mechanisms. The thesis is based on four papers (I-IV). (Papers I and II) We found that the apoptosis inducing effect was specific for sera from SLE patients when comparing with sera from various control groups. However, the apoptosis inducing effect was not related to SLE disease activity. Serum from SLE patients was demonstrated to induce classical caspase-dependent apoptosis in monocytes and lymphocytes. The apoptosis induction was not dependent on death receptors but involvement of the mitochondrial pathway was indicated. (Paper III) Phagocytosis of apoptotic cells by macrophages and C3 deposition on apoptotic cells were investigated in the presence of sera lacking different complement proteins. We found that complement-mediated opsonisation and phagocytosis of apoptotic cells, particularly those undergoing secondary necrosis, are dependent mainly upon an intact classical pathway. C1q was not more important than other classical pathway components, suggesting a role in other pathogenetic processes than defect clearance of apoptotic cells. (Paper IV) We evaluated the roles of serum complement and antibodies against histones in relation to phagocytosis of necrotic cell material by polymorphonuclear neutrophil granulocytes (PMNs). Phagocytosis of necrotic material by PMNs and high concentration of antibodies against a broad spectrum of histones correlated with active SLE disease. The specificities of these anti-histone antibodies appear to determine the complement-dependent phagocytosis. In conclusion, sera from SLE patients have the capacity to contribute to an increased load of apoptotic cells. An efficient clearance of apoptotic and necrotic cell material is dependent on a functional classical pathway, and autoantibodies against histones reflect the presence of apoptotic or necrotic cells contributing to the autoimmune process in SLE.
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| 4. |
- Gullstrand, Birgitta, et al.
(author)
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Combination of Autoantibodies Against Different Histone Proteins Influences Complement-dependent Phagocytosis of Necrotic Cell Material by Polymorphonuclear Leukocytes in Systemic Lupus Erythematosus.
- 2012
-
In: Journal of Rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 39:8, s. 1619-1627
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Polymorphonuclear leukocytes (PMN) with autoantibody-coated engulfed necrotic cell material (NC) are frequently seen in systemic lupus erythematosus (SLE). We evaluated the roles of complement, different antihistone antibodies (anti-H ab), and oxidative burst in the phagocytosis of NC by PMN, as well as association to disease activity and clinical phenotype in SLE. METHODS: ELISA and immunoblot were used to measure antibodies to different histone proteins in sera from patients with SLE and complement-deficient individuals. Phagocytosis of NC by PMN and oxidative burst activity was assessed by flow cytometry. RESULTS: A clearly increased phagocytosis of NC was seen in patients with active SLE, which was associated with high levels of anti-H ab concentrations and oxidative burst activity. The complement system contributed to efficient phagocytosis of NC by PMN through activation of the classical pathway, and the phagocytosis was mediated by FcγRIIA, FcγRIIIB, and CR1 in combination. A pattern of high phagocytosis, consumption of classical pathway components, and a broad anti-H ab repertoire was seen particularly in patients with nephritis and serositis. The combination of antibodies to several different histone proteins, often with anti-DNA antibodies, promoted an efficient uptake of NC, whereas antibodies against only histone H1 or a few histones seemed to be of less importance. CONCLUSION: The distributions of specificities among anti-H ab are of great importance in the complement-dependent phagocytosis of debris from NC in SLE. Measurement of anti-H ab could be useful in monitoring of this disease and contribute to improved understanding of the autoimmune process.
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| 5. |
- Jönsson, Göran, et al.
(author)
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Vaccination against encapsulated bacteria in hereditary C2 deficiency results in antibody response and opsonization due to antibody-dependent complement activation.
- 2012
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In: Clinical Immunology. - : Elsevier BV. - 1521-6616. ; 144:3, s. 214-227
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Journal article (peer-reviewed)abstract
- Hereditary C2 deficiency (C2D) is an important susceptibility factor for invasive infections caused by encapsulated bacteria such as pneumococci and Haemophilus influenzae type b. The infections are mostly seen in childhood indicating that antibody-mediated acquired immunity is affected. C2D persons and healthy controls were vaccinated with ActHIB® and Pneumo23®. Analysis of specific antibodies to pneumococci serotype 6B, 7F, and 23F, and Hib was performed. Post-vaccination IgG antibodies against pneumococci serotype 6B and 23F at a concentration ≥1.0mg/L was found in similar frequency in C2D persons and controls. Post-vaccination sera from C2D persons showed poor complement-mediated opsonization and phagocytosis of pneumococci by granulocytes when depending on classical and lectin pathway activation only, but increased (p=0.007) and equaled that of the normal controls when also alternative pathway activation was allowed due to antibody-dependent C2 bypass activation. In conclusion, the C2D persons benefited from the vaccination and achieve an increased phagocytic capacity.
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| 6. |
- Leffler, Jonatan, et al.
(author)
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Degradation of neutrophil extracellular traps co-varies with disease activity in patients with systemic lupus erythematosus
- 2013
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In: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6354. ; 15:4
-
Journal article (peer-reviewed)abstract
- Introduction: The ability to degrade neutrophil extracellular traps (NETs) is reduced in a subset of patients with systemic lupus erythematosus (SLE). NETs consist of chromatin covered with antimicrobial enzymes and are normally degraded by DNase-I, an enzyme which is known to have reduced activity in SLE. Decreased ability to degrade NETs is associated with disease activity. In the current study we investigated how the ability of serum from SLE patients to degrade NETs varies during the course of SLE as well as what impact this may have for the clinical phenotype of SLE.Methods: Serum from 69 patients with SLE, included in a prospective study, was taken every 60 days for a median of 784 days. The ability of serum to degrade NETs was determined and associated with clinical parameters occurring before and at the time of sampling, as well as after sampling by using conditional logistic regression.Results: As many as 41% of all patients in the study showed decreased ability to degrade NETs at least once, but with a median of 20% of all time points. Decreased degradation was associated with manifestations of glomerulonephritis as well as low complement levels and elevated levels of antibodies directed against histones and DNA. Furthermore, the odds ratio for the patient to develop alopecia and fever after an episode of decreased NETs degradation was increased by four to five times compared to normal.Conclusions: Decreased degradation of NETs is associated with clinical manifestations in SLE and may contribute to disease pathogenesis. Potential therapeutics restoring the ability to degrade NETs could be beneficial for certain patients with SLE.
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| 7. |
- Leffler, Jonatan, et al.
(author)
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Neutrophil Extracellular Traps That Are Not Degraded in Systemic Lupus Erythematosus Activate Complement Exacerbating the Disease.
- 2012
-
In: Journal of immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 188:7, s. 3522-3531
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Journal article (peer-reviewed)abstract
- Ongoing inflammation including activation of the complement system is a hallmark of systemic lupus erythematosus (SLE). Antimicrobial neutrophil extracellular traps (NETs) are composed of secreted chromatin that may act as a source of autoantigens typical for SLE. In this study, we investigated how complement interacts with NETs and how NET degradation is affected by complement in SLE patients. We found that sera from a subset of patients with active SLE had a reduced ability to degrade in vitro-generated NETs, which was mostly restored when these patients were in remission. Patients that failed to degrade NETs had a more active disease and they also displayed lower levels of complement proteins C4 and C3 in blood. We discovered that NETs activated complement in vitro and that deposited C1q inhibited NET degradation including a direct inhibition of DNase-I by C1q. Complement deposition on NETs may facilitate autoantibody production, and indeed, Abs against NETs and NET epitopes were more pronounced in patients with impaired ability to degrade NETs. NET-bound autoantibodies inhibited degradation but also further increased C1q deposition, potentially exacerbating the disease. Thus, NETs are a potent complement activator, and this interaction may play an important role in SLE. Targeting complement with inhibitors or by removing complement activators such as NETs could be beneficial for patients with SLE.
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| 8. |
- Lood, Christian, et al.
(author)
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IgG glycan hydrolysis by endoglycosidase S diminishes the proinflammatory properties of immune complexes from patients with systemic lupus erythematosus: A possible new treatment?
- 2012
-
In: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 64:8, s. 2698-2706
-
Journal article (peer-reviewed)abstract
- Objective Systemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in several organ systems, related to the presence of circulating and tissue-deposited immune complexes (ICs) that stimulate leukocytes through Fc? receptors (Fc?R) with subsequent inflammation. Treatment with endoglycosidase S (EndoS), an IgG glycanhydrolyzing bacterial enzyme from Streptococcus pyogenes, has shown beneficial effects in several experimental animal models of chronic inflammatory disease. This study was undertaken to investigate whether EndoS affects the proinflammatory properties of ICs and has the potential to be developed as a therapy for SLE. Methods ICs purified from SLE patients or RNA-containing ICs formed in vitro were treated with EndoS and used in several assays reflecting different important features of SLE pathogenesis, such as phagocytosis by polymorphonuclear cells (PMNs) and plasmacytoid dendritic cells (PDCs), complement activation, and interferon-a (IFNa) production by PDCs. Results EndoS treatment abolished all proinflammatory properties of the ICs investigated. This included Fc?R-mediated phagocytosis by PDCs (P = 0.001) and subsequent production of IFNa (P = 0.002), IC-induced classical pathway of complement activation (P = 0.008), chemotaxis, and oxidative burst activity of PMNs (P = 0.002). EndoS treatment also had a direct effect on the molecular structure of ICs, causing decreased IC size and glycosylation. Conclusion Our findings indicate that EndoS treatment has prominent effects on several pathogenetically important IC-mediated events, and suggest that EndoS has the potential to be developed as a novel therapy for SLE.
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| 9. |
- Lood, Christian, et al.
(author)
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IgG glycan hydrolysis by EndoS diminishes the pro-inflammatory properties of immune complexes from patients with SLE : a possible new treatment?
- 2012
-
In: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 64:8, s. 2698-2706
-
Journal article (peer-reviewed)abstract
- OBJECTIVESystemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in several organ systems, related to the presence of circulating and tissue-deposited immune complexes (ICs) which stimulate leukocytes through FcγRs with subsequent inflammation. Treatment with EndoS, an IgG glycan hydrolyzing bacterial enzyme from Streptococcus pyogenes, has shown beneficial effects in several experimental animal models of chronic inflammatory disease. In the present study we asked if EndoS could affect pro-inflammatory properties of ICs and have the potential to be developed as a therapy in SLE.METHODSICs, purified from SLE patients or RNA-containing ICs formed in vitro, were treated with EndoS and used in several assays reflecting different important parts of SLE pathogenesis such as phagocytosis by polymorphonuclear neutrophils (PMNs) and plasmacytoid dendritic cells (pDCs), complement activation and IFNα production by pDCs.RESULTSOur results demonstrate that EndoS treatment could abolish all pro-inflammatory properties of ICs investigated. This includes FcγR-mediated phagocytosis by pDCs (p<0.0001) and subsequent production of IFNα (p<0.0001), IC-induced classical complement pathway activation (p<0.0001), chemotaxis and oxidative burst activity of PMNs (p=0.002). We could also demonstrate direct effects on the molecular structure of ICs after EndoS treatment with decreased size and glycosylation patterns.CONCLUSIONSProminent effects of EndoS treatment were seen in several pathogenetically important IC-mediated events and our data suggest that EndoS have the potential to be developed as a novel therapy in SLE.
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| 10. |
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| 11. |
- Lood, Christian, et al.
(author)
-
Increased C1q, C4 and C3 deposition on platelets in patients with systemic lupus erythematosus - a possible link to venous thrombosis?
- 2012
-
In: Lupus. - : SAGE Publications. - 0961-2033 .- 1477-0962. ; 21:13, s. 1423-1432
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Journal article (peer-reviewed)abstract
- Objective: Patients with systemic lupus erythematosus (SLE) have an increased risk of developing vascular diseases (VD) such as myocardial infarction, stroke and venous thrombosis, which can only partly be explained by traditional risk factors. The role of platelets in this process has not been extensively studied. Platelet activation supports complement binding to the platelet surface, and increased C4d has been seen on platelets in SLE patients as well as in non-rheumatic patients with stroke. In this study we investigated in vivo platelet deposition of the classical complement pathway components C1q, C4d and C3d in relation to VD in SLE patients. Furthermore, the ability of serum to support in vitro complement deposition on fixed heterologous platelets was analyzed. Methods: Blood from 69 SLE patients and age- and sex-matched healthy individuals was collected in sodium-citrate tubes and platelets isolated by centrifugation. Complement deposition on platelets was detected by flow cytometry. Results: We could demonstrate that SLE patients had increased C1q, C3d and C4d deposition on platelets as compared to healthy controls (p < 0.0001). SLE patients with a history of venous thrombosis had increased complement deposition on platelets as compared to SLE patients without this manifestation (p < 0.05). In vitro studies demonstrated that serum from patients with lupus anticoagulant, venous thrombosis or antiphospholipid antibody syndrome supported increased platelet C4d deposition in vitro as compared to SLE patients without these manifestations (p < 0.05). Our data support the hypothesis that platelet activation and the subsequent complement deposition on platelets are central in the development of venous thrombosis in SLE. Conclusions: Altogether we suggest that complement deposition on platelets could reflect important pathogenetic events related to the development of venous thrombosis in SLE and might be used as a marker for venous thrombosis in SLE.
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| 12. |
- Lood, Christian, et al.
(author)
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Platelet activation and anti-phospholipid antibodies collaborate in the activation of the complement system on platelets in systemic lupus erythematosus.
- 2014
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:6
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Journal article (peer-reviewed)abstract
- Anti-phospholipid (aPL) antibodies are important contributors to development of thrombosis in patients with the autoimmune rheumatic disease systemic lupus erythematosus (SLE). The underlying mechanism of aPL antibody-mediated thrombosis is not fully understood but existing data suggest that platelets and the complement system are key components. Complement activation on platelets is seen in SLE patients, especially in patients with aPL antibodies, and has been related to venous thrombosis and stroke. The aim of this study was to investigate if aPL antibodies could support classical pathway activation on platelets in vitro as well as in SLE patients. Furthermore, we investigated if complement deposition on platelets was associated with vascular events, either arterial or venous, when the data had been adjusted for traditional cardiovascular risk factors. Finally, we analyzed if platelet complement deposition, both C1q and C4d, was specific for SLE. We found that aPL antibodies supported C4d deposition on platelets in vitro as well as in SLE patients (p = 0.001 and p<0.05, respectively). Complement deposition on platelets was increased in SLE patients when compared with healthy individuals (p<0.0001). However, high levels of C4d deposition and a pronounced C1q deposition were also seen in patients with rheumatoid arthritis and systemic sclerosis. In SLE, C4d deposition on platelets was associated with platelet activation, complement consumption, disease activity and venous (OR = 5.3, p = 0.02), but not arterial, thrombosis, observations which were independent of traditional cardiovascular risk factors. In conclusion, several mechanisms operate in SLE to amplify platelet complement deposition, of which aPL antibodies and platelet activation were identified as important contributors in this investigation. Complement deposition on platelets was identified as a marker of venous, but not arterial thrombosis, in SLE patients independently of traditional risk factors and aPL antibodies. Further studies are needed to elucidate the role of complement deposition on platelets in development of venous thrombosis.
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| 13. |
- Lood, Christian, et al.
(author)
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Platelet transcriptional profile and protein expression in patients with systemic lupus erythematosus: up-regulation of the type I interferon system is strongly associated with vascular disease.
- 2010
-
In: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; Jul 1, s. 1951-1957
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Journal article (peer-reviewed)abstract
- Patients with systemic lupus erythematosus (SLE) have a markedly increased risk to develop cardiovascular disease, and traditional cardiovascular risk factors fail to account for this increased risk. We used microarray to probe the platelet transcriptome in individuals with SLE and healthy controls, and the gene and protein expression of a subset of differentially expressed genes was further investigated and correlated to platelet activation status. Real-time PCR was used to confirm a type I interferon (IFN) gene signature in patients with SLE, and the IFN-regulated proteins PRKRA, IFITM1 and CD69 (p<0.0001) were found to be up-regulated in platelets from SLE patients as compared to healthy volunteers. Notably, patients with a history of vascular disease had increased expression of type I IFN-regulated proteins as well as more activated platelets as compared with patients without vascular disease. We suggest that interferogenic immune complexes stimulate production of IFNalpha which up-regulates the megakaryocytic type I IFN-regulated genes and proteins. This could affect platelet activation and contribute to development of vascular disease in SLE. In addition, platelets with type I IFN signature could be a novel marker for vascular disease in SLE.
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| 14. |
- Lood, Christian, et al.
(author)
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Protein synthesis of the pro-inflammatory S100A8/A9 complex in plasmacytoid dendritic cells and cell surface S100A8/A9 on leukocyte subpopulations in systemic lupus erythematosus
- 2011
-
In: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 13:2
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Journal article (peer-reviewed)abstract
- Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in many different organ systems, activation of leukocytes and production of pro-inflammatory cytokines. The heterodimer of the cytosolic calcium-binding proteins S100A8 and S100A9 (S100A8/A9) is secreted by activated polymorphonuclear neutrophils (PMNs) and monocytes and serves as a serum marker for several inflammatory diseases. Furthermore, S100A8 and S100A9 have many pro-inflammatory properties such as binding to Toll-like receptor 4 (TLR4). In this study we investigated if aberrant cell surface S100A8/A9 could be seen in SLE and if plasmacytoid dendritic cells (pDCs) could synthesize S100A8/A9. Methods: Flow cytometry, confocal microscopy and real-time PCR of flow cytometry-sorted cells were used to measure cell surface S100A8/A9, intracellular S100A8/A9 and mRNA levels of S100A8 and S100A9, respectively. Results: Cell surface S100A8/A9 was detected on all leukocyte subpopulations investigated except for T cells. By confocal microscopy, real-time PCR and stimulation assays, we could demonstrate that pDCs, monocytes and PMNs could synthesize S100A8/A9. Furthermore, pDC cell surface S100A8/A9 was higher in patients with active disease as compared to patients with inactive disease. Upon immune complex stimulation, pDCs up-regulated the cell surface S100A8/A9. SLE patients had also increased serum levels of S100A8/A9. Conclusions: Patients with SLE had increased cell surface S100A8/A9, which could be important in amplification and persistence of inflammation. Importantly, pDCs were able to synthesize S100A8/A9 proteins and up-regulate the cell surface expression upon immune complex-stimulation. Thus, S100A8/A9 may be a potent target for treatment of inflammatory diseases such as SLE.
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| 15. |
- Martini, Paolo G. V., et al.
(author)
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Recombinant human complement component C2 produced in a human cell line restores the classical complement pathway activity in-vitro: an alternative treatment for C2 deficiency diseases
- 2010
-
In: BMC Immunology. - : Springer Science and Business Media LLC. - 1471-2172. ; 11
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Journal article (peer-reviewed)abstract
- Background: Complement C2 deficiency is the most common genetically determined complete complement deficiency and is associated with a number of diseases. Most prominent are the associations with recurrent serious infections in young children and the development of systemic lupus erythematosus (SLE) in adults. The links with these diseases reflect the important role complement C2 plays in both innate immunity and immune tolerance. Infusions with normal fresh frozen plasma for the treatment of associated disease have demonstrated therapeutic effects but so far protein replacement therapy has not been evaluated. Results: Human complement C2 was cloned and expressed in a mammalian cell line. The purity of recombinant human C2 (rhC2) was greater than 95% and it was characterized for stability and activity. It was sensitive to C1s cleavage and restored classical complement pathway activity in C2-deficient serum both in a complement activation ELISA and a hemolytic assay. Furthermore, rhC2 could increase C3 fragment deposition on the human pathogen Streptococcus pneumoniae in C2-deficient serum to levels equal to those with normal serum. Conclusions: Taken together these data suggest that recombinant human C2 can restore classical complement pathway activity and may serve as a potential therapeutic for recurring bacterial infections or SLE in C2-deficient patients.
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| 16. |
- Nielsen, Christoffer T, et al.
(author)
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Increased IgG on cell-derived plasma microparticles in systemic lupus erythematosus is associated with autoantibodies and complement activation.
- 2012
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In: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 64:4, s. 1227-1236
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Journal article (peer-reviewed)abstract
- OBJECTIVE.: To quantify immunoglobulin and C1q on circulating cell-derived microparticles (MPs) in systemic lupus erythematosus (SLE) and to correlate this with clinical and serological parameters. METHODS.: Sixty-eight clinically well-characterized SLE patients, 38 healthy controls (HC), 6 systemic sclerosis (SSc), and 6 rheumatoid arthritis (RA) patients were included. The numbers of annexin V-binding MPs displaying IgG, IgM or C1q were enumerated by flow cytometry. MP protein levels were determined by mass spectrometry in clinically defined subsets of SLE patients and controls. The MP-IgG load was determined by flow cytometry of all SLE and HC samples. RESULTS.: SLE patients had significantly increased total and relative numbers of IgG-positive MPs (p = 0.0004) with a much higher average IgG-load/MP (p < 0.0001) than HCs. Quantitative mass spectrometry of purified MPs verified significantly increased IgG, IgM, and C1q in SLE. In RA and SSc the average IgG/MP was significantly lower than in SLE (p = 0.006 and 0.05, respectively). Also, IgM/MP and C1q/MP were higher in SLE than in controls (p < 0.05) except for IgM in the RA-group. IgG-positive MPs were significantly associated with the presence of anti-dsDNA, anti-ENA, and anti-histone antibodies, with total IgG, and with decreased leukocyte counts. Average IgG/MP was associated with lower concentrations of MPs, the presence of anti-C1q antibodies, and with complement consumption. CONCLUSIONS.: Circulating cell-derived MPs in SLE carry increased loads of IgG, IgM, and C1q and IgG-MPs are associated with autoantibodies and complement activation. The findings link immunological reactions on MPs with the etiopathology of SLE. © 2012 American College of Rheumatology.
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| 17. |
- Ohlsson, Susanne, et al.
(author)
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Serum from patients with systemic vasculitis induces alternatively activated macrophage M2c polarization.
- 2014
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In: Clinical Immunology. - : Elsevier BV. - 1521-6616. ; 152:1-2, s. 10-19
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Journal article (peer-reviewed)abstract
- Anti-neutrophil cytoplasmic antibody associated vasculitides (AAV) are conditions defined by an autoimmune small vessel inflammation. Dying neutrophils are found around the inflamed vessels and the balance between infiltrating neutrophils and macrophages is important to prevent autoimmunity. Here we investigate how sera from AAV patients may regulate macrophage polarization and function. Macrophages from healthy individuals were differentiated into M0, M1, M2a, M2b or M2c macrophages using a standardized protocol, and phenotyped according to their expression surface markers and cytokine production. These phenotypes were compared with those of macrophages stimulated with serum from AAV patients or healthy controls. While the healthy control sera induced a M0 macrophage, AAV serum promoted polarization towards the M2c subtype. No sera induced M1, M2a or M2b macrophages. The M2c subtype showed increased phagocytosis capacity compared with the other subtypes. The M2c polarization found in AAV is consistent with previous reports of increased levels of M2c-associated cytokines.
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| 18. |
- Persson, Ulf, et al.
(author)
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A Candidate Gene Approach to ANCA-Associated Vasculitis Reveals Links to the C3 and CTLA-4 Genes but not to the IL1-Ra And Fc gamma-RIIa Genes
- 2013
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In: Kidney and Blood Pressure Research. - : Karger: Open Access Journals / S. Karger AG. - 1420-4096 .- 1423-0143. ; 37:6, s. 641-648
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Journal article (peer-reviewed)abstract
- Background/Aims: The aim of the study is to search for associations between Antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) and polymorphisms in the genes of four key molecules possibly involved in different pathogenic pathways; complement C3, CTLA-4, Fc gamma-RIIa and IL1-Ra. Patients and Methods: Patients with AAV (n=105) subgrouped as microscopic polyangiitis or granulomatosis with polyangiitis (Wegeners granulomatosis) and myeloperoxidase (MPO) or proteinase 3 (PR3) ANCA positive were compared to a control group of 200 blood donors. Polymorphisms in the genes were analysed with PCR amplification of DNA. Results: The diagnosis of AAV was confirmed in the 105 cases. The gene frequency of C3F was 0.27 in the PR3-ANCA subgroup (p=0.041) compared to 0,19 in the control group. The number of patients homozygous for the shortest 86 bp allele of CTLA-4 was significantly decreased in the whole group of patients (p=0.049). No differences were evident in the Fc gamma-RIIa and IL1-Ra polymorphisms when compared to controls, neither in the whole group of patients, nor in any of the sub-groups. Conclusion: The aberrant gene frequency of the C3F allele among PR3-ANCA positive patients and the findings with the CTLA-4 polymorphism indicates that complement may be involved in pathogenesis and that T-cell activation also is of importance in these diseases.
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| 19. |
- Tydén, Helena, et al.
(author)
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Increased serum levels of S100A8/A9 and S100A12 are associated with cardiovascular disease in patients with inactive systemic lupus erythematosus.
- 2013
-
In: Rheumatology. - : Oxford University Press (OUP). - 1462-0332 .- 1462-0324. ; 52:11, s. 2048-2055
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Journal article (peer-reviewed)abstract
- Objectives. Patients with SLE have an increased morbidity and mortality from cardiovascular disease (CVD). The reason for this is not entirely understood, but is believed to be partly related to the long-lasting inflammatory process seen in SLE. The aim of the present study was to investigate whether there is an association between CVD and serum levels of the proinflammatory proteins S100A8/A9 and S100A12 in SLE.Methods. Serum levels of S100A8/A9 and S100A12 were measured with ELISA in 237 SLE patients with clinically inactive disease and without infections, as well as in 100 healthy individuals. Cardiovascular manifestations were defined according to the SLICC/ACR Damage Index (SLICC/ACR-DI).Results. Serum levels of S100A8/A9 were elevated in our inactive SLE patients as compared with healthy individuals (P < 0.0001), which was not seen for S100A12 (P = 0.12). SLE patients with a history of CVD had increased serum levels of both S100A8/A9 and S100A12 compared with patients with no CVD or venous thromboembolism (P = 0.003 and P = 0.006, respectively). The presence of organ damage according to SLICC/ACR-DI was associated with an increase in both S100A8/A9 and S100A12 serum levels (P = 0.001 and P = 0.006, respectively).Conclusion. Elevated serum levels of S100A8/A9 and S100A12 may be used as an indicator of severe disease and CVD in SLE, suggesting that SLE patients with elevated serum S100A8/A9 and S100A12 concentrations may benefit from more intense cardiovascular primary preventive strategies and possibly also from more intense and early immunosuppressive treatment.
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