| 1. |
- Balboni, Imelda, et al.
(författare)
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Brief Report : Interferon-α Induction and Detection of Anti-Ro, Anti-La, Anti-Sm, and Anti-RNP Autoantibodies by Autoantigen Microarray Analysis in Juvenile Dermatomyositis
- 2013
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 65:9, s. 2424-2429
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Tidskriftsartikel (refereegranskat)abstract
- Objective:To evaluate serum interferon- (IFN) activity in the context of autoantibody profiles in patients with juvenile dermatomyositis (JDM). Methods:Sera from 36 patients with JDM were analyzed. Autoantibody profiles were determined by probing microarrays, which were fabricated with approximate to 80 distinct autoantigens, with serum and a Cy3-conjugated secondary antibody. Arrays were scanned and analyzed to determine antigen reactivity. Serum IFN activity was measured using a functional reporter cell assay. Sera were assayed alone or in combination with cellular material released from necrotic U937 cells to stimulate peripheral blood mononuclear cells from healthy donors in vitro, and IFN production in culture was measured by a dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA). Results:Reactivity against at least 1 of 41 autoantigens on the microarray, including Ro 52, Ro 60, La, Sm, and RNP, was observed in 75% of the serum samples from patients with JDM. IFN activity was detected in 7 samples by reporter cell assay. The reporter cell assay showed a significant association of reactivity against Ro, La, Sm, and proliferating cell nuclear antigen with serum IFN activity (P = 0.005). Significance Analysis of Microarrays (SAM) identified increased reactivity against Sm, RNP, Ro 52, U1-C, and Mi-2 in these sera. Sixteen samples induced IFN production as measured by DELFIA, and there was a significant association of reactivity against Ro, La, Sm, and RNP with the induction of IFN by serum and necrotic cell material (P = 0.034). SAM identified increased reactivity against Ro 60 in these sera. Conclusion:These data support the hypothesis that nucleic acid-associated autoantibodies, including the Ro/La and Sm/RNP complexes, may stimulate the production of active IFN in children with JDM.
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| 2. |
- Bengtsson, Anders A, et al.
(författare)
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Pharmacokinetics, tolerability, and preliminary efficacy of ABR-215757, a new quinoline-3-carboxamide derivative, in murine and human SLE
- 2012
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 64:5, s. 1579-1588
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess the efficacy of ABR-215757, a new immunomodulatory small molecule in a murine SLE model, to evaluate the pharmacokinetics and tolerability in SLE patients at doses predicted to be efficacious and safe, and to determine the maximum tolerated dose (MTD). METHODS: The efficacy of ABR-215757 was studied in lupus prone MRLlpr/lpr mice and compared with established SLE treatments. Dose response data of ABR-215757 were together with pharmacokinetic data used to calculate effective and safe clinical doses. The pharmacokinetics and tolerance of ABR-215757 were evaluated in a Phase Ib double-blind, placebo controlled, dose-escalation study where cohorts of SLE patients received daily oral treatment for 12 weeks. RESULTS: Disease inhibition in MRLlpr/lpr mice, comparable to that of prednisolone and mycophenolate mofetil, was obtained with ABR-215757. Prominent effects on disease manifestations, serological markers and a steroid sparing effect were seen for ABR-215757. The pharmacokinetic properties in SLE patients were linear and well suitable for once daily oral treatment. The majority of the adverse events (AEs) were mild or moderate and transient. The most frequent AEs were arthralgia and myalgia, reported at the highest (4.5 and 6 mg/day) dose levels. At 4.5 mg and higher some AEs of severe intensity and serious adverse events (SAEs) were reported. CONCLUSION: ABR-215757 effectively inhibited disease and had a steroid sparing effect in experimental lupus. Clinical doses up to 3 mg/day, dose levels predicted from pre-clinical studies to be efficacious and safe, were well tolerated in the SLE patients. The MTD was concluded to be 4.5 mg/day.
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| 3. |
- Berggren, Olof, et al.
(författare)
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B lymphocytes enhance the interferon-α production by plasmacytoid dendritic cells
- 2012
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 64:10, s. 3409-3419
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:Type I interferon (IFN) system and B cells are activated in many autoimmune diseases, e.g. systemic lupus erythematosus (SLE). IFNα produced by plasmacytoid dendritic cells (pDC) stimulate several B cell functions, including autoantibody production. However, not much is known how B cells influence the pDC function. We therefore investigated the regulatory effect of B cells on IFNα production by pDC.METHODS:PDC and B cells from healthy blood donor PBMC were stimulated with RNA-containing immune complexes (RNA-IC) consisting of U1 snRNP and IgG from SLE patients, herpes simplex virus (HSV) or oligonucleotide ODN2216, alone or in co-cultures. IFNα, several other cytokines and pDC or B cell-associated surface molecules were analyzed by immunoassays or flow cytometry.RESULTS:B cells enhanced the IFNα production by pDC up to 47-fold, and the effect was most pronounced for pDC stimulated with RNA-IC. Anti-CD31 antibody reduced the RNA-IC-induced IFNα production by 80%, but not when ODN2216 was used as IFN-inducer. Supernatants from ODN2216-stimulated B cells promoted IFNα production by pDC, while supernatants from RNA-IC-stimulated B cells did not.CONCLUSION: Our results reveal a novel B cell function, enhancing the type I IFN production by pDC. Since B cells are activated by type I IFN, this pDC-B cell cross-talk might be of fundamental importance in the etiopathogenesis of SLE, and contribute to a chronic immune activation in SLE and other systemic rheumatic diseases.
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| 4. |
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| 5. |
- Blomberg, Stina, et al.
(författare)
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Expression of the markers BDCA-2 and BDCA-4 and production of interferon-alpha by plasmacytoid dendritic cells in systemic lupus erythematosus
- 2003
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 48:9, s. 2524-32
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To study the expression of blood dendritic cell antigen 2 (BDCA-2) and BDCA-4 molecules by plasmacytoid dendritic cells (PDCs) in the blood of patients with systemic lupus erythematosus (SLE), and to study PDC production of interferon-alpha (IFN alpha) and its inhibition by anti-BDCA-2 and anti-BDCA-4 antibodies. METHODS: Peripheral blood mononuclear cells (PBMCs) from SLE patients (SLE PBMCs) and from healthy controls were induced to produce IFN alpha in vitro by SLE serum containing an endogenous IFN alpha-inducing factor (SLE-IIF) or by herpes simplex virus type 1 (HSV-1). The frequencies and numbers of BDCA-2-, BDCA-3-, and BDCA-4-expressing cells were analyzed by flow cytometry, and the effects of anti-BDCA-2 and anti-BDCA-4 monoclonal antibodies (mAb) on IFN alpha production were investigated. RESULTS: IFN alpha production by SLE PBMCs induced by SLE-IIF or HSV-1 was decreased compared with that of healthy control PBMCs (P = 0.002 and P = 0.0007, respectively). The proportions of BDCA-2- and BDCA-3-expressing cells in SLE PBMCs were reduced compared with those in PBMCs from healthy controls (P = 0.01 and P = 0.004, respectively). IFN alpha producers in culture, especially among SLE PBMCs, displayed reduced BDCA-2 expression and constituted only a minority of the BDCA-2-positive cells, at least in healthy control PBMCs (median 18%). IFN alpha production by both SLE and healthy control PBMCs stimulated by SLE-IIF or HSV-1 was markedly reduced by anti-BDCA-2 mAb (median 81-98% inhibition). Anti-BDCA-4 mAb only partially inhibited SLE-IIF-induced IFN alpha production. CONCLUSION: SLE patients had a reduced number of BDCA-2-expressing PDCs, also termed natural IFN alpha-producing cells, and their IFN alpha production could be inhibited by anti-BDCA-2/4 mAb. Such mAb may be a therapeutic option for inhibiting the ongoing IFN alpha production in SLE patients.
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| 6. |
- Båve, Ullvi, et al.
(författare)
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Activation of the type I interferon system in primary Sjögren's syndrome : a possible etiopathogenic mechanism
- 2005
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 52:4, s. 1185-1195
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Tidskriftsartikel (refereegranskat)abstract
- Objective The etiopathogenesis of primary Sjögren's syndrome (SS) is largely unknown. In other autoimmune diseases, type I interferon (IFN) may play a pivotal role by triggering and sustaining the disease process. We therefore aimed to determine whether patients with primary SS had an activated type I IFN system. Methods Salivary gland biopsy specimens and sera from patients with primary SS were investigated for the occurrence of IFNα-producing cells and measurable IFNα levels, respectively. The ability of primary SS sera together with apoptotic or necrotic cells to induce IFNα production in normal peripheral blood mononuclear cells was examined. The IFNα inducer was characterized, and IFNα-producing cells were identified. Clinical data were correlated with the IFNα-inducing capacity of primary SS sera. Results Numerous IFNα-producing cells were detected in salivary gland biopsy specimens, despite low serum IFNα levels. Autoantibodies to RNA-binding proteins, combined with material released by necrotic or late apoptotic cells, were potent inducers of IFNα production in plasmacytoid dendritic cells (PDCs). This appeared to be attributable to RNA-containing immune complexes triggering PDCs by means of RNA and interaction with Fcγ receptor IIa. The IFNα-inducing capacity of sera was associated with positive results of a labial salivary gland biopsy (focus score ≥1) and with dermatologic, hematologic, and pulmonary manifestations. Conclusion Patients with primary SS have an activated type I IFN system. Although virus may initiate the production of IFN, the continued IFNα synthesis is caused by RNA-containing immune complexes that activate PDCs to prolong IFNα production at the tissue level. This IFNα promotes the autoimmune process by a vicious circle–like mechanism, with increased autoantibody production and formation of more endogenous IFNα inducers.
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| 7. |
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| 8. |
- Eloranta, Maija-Leena, et al.
(författare)
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A possible mechanism for endogenous activation of the type I interferon system in myositis patients with anti-Jo-1 or anti-Ro 52/anti-Ro 60 autoantibodies
- 2007
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 56:9, s. 3112-3124
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate type I interferon (IFN) system activation and its correlation with autoantibodies and organ manifestations in polymyositis (PM), dermatomyositis (DM), and inclusion body myositis. METHODS: Sera from 30 patients and 16 healthy controls, or purified IgG, were combined with material released from necrotized cells to stimulate IFNalpha production by peripheral blood mononuclear cells (PBMCs) from healthy blood donors. Muscle biopsy specimens from 25 patients and 7 healthy controls were investigated for blood dendritic cell antigen 2 (BDCA-2)-positive plasmacytoid dendritic cells (PDCs) and IFNalpha/beta-inducible myxovirus resistance 1 (MX-1) protein. RESULTS: Sera from 13 patients who were positive for anti-Jo-1 or anti-Ro 52/anti-Ro 60 autoantibodies induced IFNalpha production in PBMCs when combined with necrotic cell material. In addition, IgG prepared from anti-Jo-1-positive PM sera induced IFNalpha with necrotic material, but not when the latter was treated with RNase. BDCA-2 expression in PDCs in muscle tissue was increased in PM patients with anti-Jo-1 autoantibodies, while MX-1 staining in capillaries was increased in DM patients, compared with healthy individuals. IFNalpha-inducing capacity correlated with interstitial lung disease, while MX-1 expression in the capillaries correlated with DM. CONCLUSION: Immune complexes containing anti-Jo-1 or anti-Ro 52/anti-Ro 60 autoantibodies and RNA may act as endogenous IFNalpha inducers that activate IFNalpha production in PDCs. These PDCs could be of importance for inducing myositis, whereas in DM patients without autoantibodies the presence of MX-1 protein in capillaries suggests another cellular IFNalpha source and induction mechanism. Consequently, the type I IFN system may be of importance in both PM and DM, but via different pathways.
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