scholarly journals POS0388 INTERLEUKIN 40 (IL-40) IS UP-REGULATED IN RHEUMATOID ARTHRITIS (RA) AND ASSOCIATED WITH DISEASE ACTIVITY, LEVELS OF AUTOANTIBODIES AND CHEMOKINES

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 424.1-424
Author(s):  
A. Navrátilová ◽  
L. Andres Cerezo ◽  
H. Hulejova ◽  
V. Becvar ◽  
D. Tegzová ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
Synovial Fluid ◽  
Disease Activity ◽  
B Cell ◽  
Synovial Tissue ◽  
Lupus Erythematosus ◽  
Synovial Fibroblasts ◽  
Clinical Activity

Background:Interleukin 40 (IL-40) is newly identified B cell - associated cytokine implicated in humoral immune responses and in B cell development. As B cells play a pivotal role in autoimmunity, we aimed to investigate the function of IL-40 in rheumatoid arthritis (RA).Objectives:The aim of our study was to determine the function of IL-40 in RA.Methods:IL-40 expression in the synovial tissue was determined by immunohistochemistry and immunofluorescence (n=4-5). IL-40 was analysed in the serum/synovial fluid of patients with RA (n=69), systemic lupus erythematosus (SLE; n=69), osteoarthritis (OA; n=44), and in healthy controls (HC; n=25). Given the association of IL-40 with B cells, we analysed the effect of rituximab therapy on the serum IL-40 in 19 patients with RA after 16 and 24 weeks of the therapy. The clinical activity of patients with RA was assessed according to the 28 joint count Disease Activity Score (DAS28). Levels of C-reactive protein (CRP) and autoantibodies were measured by routine laboratory techniques. In vitro experiments were performed in RA synovial fibroblasts (n=9). Levels of cytokines and inflammatory mediators were determined in serum, synovial fluid and supernatants using ELISA or multiplex immunoassay.Results:IL-40 was overexpressed in RA synovial tissue compared to OA, particularly by synovial fibroblasts and immune cells such as B and T lymphocytes, macrophages and neutrophils. The levels of IL-40 were significantly higher in the synovial fluid of RA patients compared to OA (33.2 (6.6-68.9) vs. 0.7 (0.1-2.4) ng/ml; p<0.0001). In addition, IL-40 was increased in the serum of RA patients compared to SLE, OA or HC (4.8 (1.7-24.9) vs. 1.4 (1.0-1.9), 1.6 (0.6-3.1) or 1.5 (0.7-2.7) ng/ml; p<0.0001 for all) and decreased after 16 (p<0.01) and 24 weeks (p<0.001) in a subgroup of rituximab treated patients with RA. IL-40 levels in RA patients correlated with autoantibodies rheumatoid factor (IgM) and anti-citrullinated protein antibody (ACPA) in the serum (p<0.0001 and p<0.01) as well as in the synovial fluid (p<0.0001 and p<0.001). IL-40 in RA synovial fluid was also significantly associated with DAS28 (p<0.05), synovial fluid leukocyte count (p<0.01), number of swollen joints (p<0.05) and neutrophil attractants IL-8 (p<0.01) and MIP-1α (p<0.01). RA synovial fibroblasts exposed to recombinant IL-40 increased secretion of IL-8 (p<0.01), MCP-1 (p<0.05) and MMP-13 (p<0.01) compared to unstimulated cells in in vitro conditions.Conclusion:Our results show for the first time that IL-40 is elevated in RA and decreases following B-cell depletion therapy. The association of IL-40 with autoantibodies and chemokines may imply its potential involvement in RA development. Moreover, IL-40 up-regulates the secretion of chemokines and MMP-13 by synovial fibroblasts, indicating its role in the regulation of inflammation and tissue destruction in RA.Acknowledgements:Supported by MHCR 023728 a SVV 260 523Disclosure of Interests:None declared

scholarly journals IL-40: A New B Cell-Associated Cytokine Up-Regulated in Rheumatoid Arthritis Decreases Following the Rituximab Therapy and Correlates With Disease Activity, Autoantibodies, and NETosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Adela Navrátilová ◽  
Lucie Andrés Cerezo ◽  
Hana Hulejová ◽  
Viktor Bečvář ◽  
Michal Tomčík ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Disease Activity ◽  
B Cell ◽  
Synovial Tissue ◽  
Lupus Erythematosus ◽  
Synovial Fibroblasts ◽  
Tissue Destruction ◽  
Humoral Immune ◽  
B Cell Homeostasis

BackgroundInterleukin 40 (IL-40) is a newly identified B cell-associated cytokine implicated in humoral immune responses and B cell homeostasis. As B cells play a pivotal role in autoimmunity, we investigated the function of IL-40 in rheumatoid arthritis (RA).MethodsIL-40 expression was determined in the synovial tissue from RA and osteoarthritis (OA) patients. IL-40 was analysed in the serum/synovial fluid of patients with RA (n=50), systemic lupus erythematosus (SLE, n=69), OA (n=44), and healthy controls (HC, n=50). We assessed the changes of IL-40 levels in RA patients following the B cell depletion by rituximab (n=29) or after the TNF inhibition by adalimumab (n=25). We examined the relationship between IL-40, disease activity, autoantibodies, cytokines, and NETosis markers. Effect of IL-40 on synovial fibroblasts was determined.ResultsIL-40 was overexpressed in RA synovial tissue, particularly by synovial lining and infiltrating immune cells. The levels of IL-40 were up-regulated in the synovial fluid of RA versus OA patients (p&lt;0.0001). Similarly, IL-40 was increased in the serum of RA patients compared to HC, OA, or SLE (p&lt;0.0001 for all) and decreased after 16 and 24 weeks (p&lt;0.01 and p&lt;0.01) following rituximab treatment. No significant effect of adalimumab on IL-40 was observed. IL-40 levels in RA patients correlated with rheumatoid factor-IgM and anti-cyclic citrullinated peptides (anti-CCP) in the serum (p&lt;0.0001 and p&lt;0.01), as well as in the synovial fluid (p&lt;0.0001 and p&lt;0.001). Synovial fluid IL-40 was also associated with disease activity score DAS28 (p&lt;0.05), synovial fluid leukocyte count (p&lt;0.01), neutrophil attractants IL-8 (p&lt;0.01), MIP-1α (p&lt;0.01), and markers of neutrophil extracellular traps externalization (NETosis) such as proteinase 3 (p&lt;0.0001) and neutrophil elastase (p&lt;0.0001). Synovial fibroblasts exposed to IL-40 increased the secretion of IL-8 (p&lt;0.01), MCP-1 (p&lt;0.05), and MMP-13 (p&lt;0.01) compared to the unstimulated cells.ConclusionsWe show the up-regulation of IL-40 in RA and its decrease following B cell depleting therapy. The association of IL-40 with autoantibodies, chemokines, and markers of NETosis may imply its potential involvement in RA development. Moreover, IL-40 up-regulates the secretion of chemokines and MMP-13 in synovial fibroblasts, indicating its role in the regulation of inflammation and tissue destruction in RA.

scholarly journals Mast cells in early rheumatoid arthritis associate with disease severity and support B cell autoantibody production

2018 ◽  
Vol 77 (12) ◽  
pp. 1773-1781 ◽  
Author(s):  
Felice Rivellese ◽  
Daniele Mauro ◽  
Alessandra Nerviani ◽  
Sara Pagani ◽  
Liliane Fossati-Jimack ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
Mast Cells ◽  
Disease Activity ◽  
B Cell ◽  
Synovial Tissue ◽  
Autoantibody Production ◽  
Early Ra ◽  
Treatment Naïve

ObjectivesMast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). However, their contribution remains controversial. To establish their role in RA, we analysed their presence in the synovium of treatment-naïve patients with early RA and their association and functional relationship with histological features of synovitis.MethodsSynovial tissue was obtained by ultrasound-guided biopsy from treatment-naïve patients with early RA (n=99). Immune cells (CD3/CD20/CD138/CD68) and their relationship with CD117+MCs in synovial tissue were analysed by immunohistochemistry (IHC) and immunofluorescence (IF). The functional involvement of MCs in ectopic lymphoid structures (ELS) was investigated in vitro, by coculturing MCs with naïve B cells and anticitrullinated protein antibodies (ACPA)-producing B cell clones, and in vivo in interleukin-27 receptor alpha (IL27ra)-deficient and control mice during antigen-induced arthritis (AIA).ResultsHigh synovial MC counts are associated with local and systemic inflammation, autoantibody positivity and high disease activity. IHC/IF showed that MCs reside at the outer border of lymphoid aggregates. Furthermore, human MCs promote the activation and differentiation of naïve B cells and induce the production of ACPA, mainly via contact-dependent interactions. In AIA, synovial MC numbers increase in IL27ra deficient mice, in association with ELS and worse disease activity.ConclusionsSynovial MCs identify early RA patients with a severe clinical form of synovitis characterised by the presence of ELS.

scholarly journals Splicing machinery is impaired in rheumatoid arthritis, associated with disease activity and modulated by anti-TNF therapy

2021 ◽  
pp. annrheumdis-2021-220308
Author(s):  
Alejandro Ibáñez-Costa ◽  
Carlos Perez-Sanchez ◽  
Alejandra María Patiño-Trives ◽  
Maria Luque-Tevar ◽  
Pilar Font ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Disease Activity ◽  
Synovial Fibroblasts ◽  
Data Set ◽  
Altered Expression ◽  
Healthy Donors ◽  
Inflammatory Profile ◽  
Splicing Machinery

ObjectivesTo characterise splicing machinery (SM) alterations in leucocytes of patients with rheumatoid arthritis (RA), and to assess its influence on their clinical profile and therapeutic response.MethodsLeucocyte subtypes from 129 patients with RA and 29 healthy donors (HD) were purified, and 45 selected SM elements (SME) were evaluated by quantitative PCR-array based on microfluidic technology (Fluidigm). Modulation by anti-tumour necrosis factor (TNF) therapy and underlying regulatory mechanisms were assessed.ResultsAn altered expression of several SME was found in RA leucocytes. Eight elements (SNRNP70, SNRNP200, U2AF2, RNU4ATAC, RBM3, RBM17, KHDRBS1 and SRSF10) were equally altered in all leucocytes subtypes. Logistic regressions revealed that this signature might: discriminate RA and HD, and anti-citrullinated protein antibodies (ACPAs) positivity; classify high-disease activity (disease activity score-28 (DAS28) >5.1); recognise radiological involvement; and identify patients showing atheroma plaques. Furthermore, this signature was altered in RA synovial fluid and ankle joints of K/BxN-arthritic mice. An available RNA-seq data set enabled to validate data and identified distinctive splicing events and splicing variants among patients with RA expressing high and low SME levels. 3 and 6 months anti-TNF therapy reversed their expression in parallel to the reduction of the inflammatory profile. In vitro, ACPAs modulated SME, at least partially, by Fc Receptor (FcR)-dependent mechanisms. Key inflammatory cytokines further altered SME. Lastly, induced SNRNP70-overexpression and KHDRBS1-overexpression reversed inflammation in lymphocytes, NETosis in neutrophils and adhesion in RA monocytes and influenced activity of RA synovial fibroblasts.ConclusionsOverall, we have characterised for the first time a signature comprising eight dysregulated SME in RA leucocytes from both peripheral blood and synovial fluid, linked to disease pathophysiology, modulated by ACPAs and reversed by anti-TNF therapy.

scholarly journals The correlation of syndecan-4 with disease activity and serological characteristics of rheumatoid arthritis

2021 ◽  
Author(s):  
Juan Zhao ◽  
Xia Ye ◽  
Zhuoli Zhang
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Disease Activity ◽  
Rheumatoid Factor ◽  
Synovial Tissue ◽  
Synovial Fibroblasts ◽  
Healthy Controls ◽  
Immunosorbant Assay ◽  
Enzyme Linked Immunosorbant Assay

Abstract [Objectives]To investigate the expression of syndecan-4 in serum, synovial fluid (SF) and synovium in rheumatoid arthritis (RA) by comparing with osteoarthritis (OA) patients, and to analyze the correlation of syndecan-4 with disease activity of RA .[Methods]Syndecan-4 in sera of 60 RA patients, 20 OA patients, 20 healthy controls, and in paired SF of 23 RA patients were tested by enzyme linked immunosorbant assay (ELISA). The expressions of syndecan-4 in synovium of 5 RA patients and 5 OA patients were detected by immunohistochemistry. The expressions of syndecan-4 of cultured synovial fibroblasts from RA and OA patients were detected by immunofluorescence. The correlation between serum syndecan-4 concentration and disease activity were analyzed in 60 RA patients.[Results]The serum syndedcan-4 concentration was significantly higher in RA patients than in OA patients and healthy controls, and was higher in rheumatoid factor (RF)-positive RA patients than in RF-negative ones. Syndecan-4 concentration in SF of RA patients was comparable with OA patients. Syndecan-4 expression in synovial tissue was similar between RA and OA patients. The syndecan-4 concentration was significantly lower in synovial fluid than in serum, either in RA or in OA patients. The serum and SF syndecan-4 concentrations were both positively correlated with RA disease activity scores.[Conclusion]The serum syndecan-4 concentration is higher in RA patients than in OA patients, and significantly higher in RF-positive RA patients than in RF-negative ones. The serum and SF syndecan-4 concentrations were both positively correlated with disease activity of RA patients.

scholarly journals OP0005 ELEVATED STAT1 EXPRESSION BUT NOT PHOSPHORYLATION IN LUPUS B CELLS CORRELATES WITH DISEASE ACTIVITY AND INCREASED PLASMABLAST SUSCEPTIBILITY

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 4-5
Author(s):  
A. Aue ◽  
F. Szelinski ◽  
S. Weißenberg ◽  
A. Wiedemann ◽  
T. Rose ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
Autoimmune Diseases ◽  
Disease Activity ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Type I ◽  
Type I Ifn ◽  
Systemic Lupus ◽  
B Cell Subsets

Background:Systemic lupus erythematosus (SLE) is characterized by two pathogenic key signatures, type I interferon (IFN) (1.) and B-cell abnormalities (2.). How these signatures are interrelated is not known. Type I-II IFN trigger activation of Janus kinase (JAK) – signal transducer and activator of transcription (STAT).Objectives:JAK-STAT inhibition is an attractive therapeutic possibility for SLE (3.). We assess STAT1 and STAT3 expression and phosphorylation at baseline and after IFN type I and II stimulation in B-cell subpopulations of SLE patients compared to other autoimmune diseases and healthy controls (HD) and related it to disease activity.Methods:Expression of STAT1, pSTAT1, STAT3 and pSTAT3 in B and T-cells of 21 HD, 10 rheumatoid arthritis (RA), 7 primary Sjögren’s (pSS) and 22 SLE patients was analyzed by flow cytometry. STAT1 and STAT3 expression and phosphorylation in PBMCs of SLE patients and HD after IFNα and IFNγ incubation were further investigated.Results:SLE patients showed substantially higher STAT1 but not pSTAT1 in B and T-cell subsets. Increased STAT1 expression in B cell subsets correlated significantly with SLEDAI and Siglec-1 on monocytes, a type I IFN marker (4.). STAT1 activation in plasmablasts was IFNα dependent while monocytes exhibited dependence on IFNγ.Figure 1.Significantly increased expression of STAT1 by SLE B cells(A) Representative histograms of baseline expression of STAT1, pSTAT1, STAT3 and pSTAT3 in CD19+ B cells of SLE patients (orange), HD (black) and isotype controls (grey). (B) Baseline expression of STAT1 and pSTAT1 or (C) STAT3 and pSTAT3 in CD20+CD27-, CD20+CD27+ and CD20lowCD27high B-lineage cells from SLE (orange) patients compared to those from HD (black). Mann Whitney test; ****p≤0.0001.Figure 2.Correlation of STAT1 expression by SLE B cells correlates with type I IFN signature (Siglec-1, CD169) and clinical activity (SLEDAI).Correlation of STAT1 expression in CD20+CD27- näive (p<0.0001, r=0.8766), CD20+CD27+ memory (p<0.0001, r=0.8556) and CD20lowCD27high (p<0.0001, r=0.9396) B cells from SLE patients with (A) Siglec-1 (CD169) expression on CD14+ cells as parameter of type I IFN signature and (B) lupus disease activity (SLEDAI score). Spearman rank coefficient (r) was calculated to identify correlations between these parameters. *p≤0.05, **p≤0.01. (C) STAT1 expression in B cell subsets of a previously undiagnosed, active SLE patient who was subsequently treated with two dosages of prednisolone and reanalyzed.Conclusion:Enhanced expression of STAT1 by B-cells candidates as key node of two immunopathogenic signatures (type I IFN and B-cells) related to important immunopathogenic pathways and lupus activity. We show that STAT1 is activated upon IFNα exposure in SLE plasmablasts. Thus, Jak inhibitors, targeting JAK-STAT pathways, hold promise to block STAT1 expression and control plasmablast induction in SLE.References:[1]Baechler EC, Batliwalla FM, Karypis G, Gaffney PM, Ortmann WA, Espe KJ, et al. Interferon-inducible gene expression signature in peripheral blood cells of patients with severe lupus. Proc Natl Acad Sci U S A. 2003;100(5):2610-5.[2]Lino AC, Dorner T, Bar-Or A, Fillatreau S. Cytokine-producing B cells: a translational view on their roles in human and mouse autoimmune diseases. Immunol Rev. 2016;269(1):130-44.[3]Dorner T, Lipsky PE. Beyond pan-B-cell-directed therapy - new avenues and insights into the pathogenesis of SLE. Nat Rev Rheumatol. 2016;12(11):645-57.[4]Biesen R, Demir C, Barkhudarova F, Grun JR, Steinbrich-Zollner M, Backhaus M, et al. Sialic acid-binding Ig-like lectin 1 expression in inflammatory and resident monocytes is a potential biomarker for monitoring disease activity and success of therapy in systemic lupus erythematosus. Arthritis Rheum. 2008;58(4):1136-45.Disclosure of Interests:Arman Aue: None declared, Franziska Szelinski: None declared, Sarah Weißenberg: None declared, Annika Wiedemann: None declared, Thomas Rose: None declared, Andreia Lino: None declared, Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen

scholarly journals The expansion of activated naive DNA autoreactive B cells and its association with disease activity in systemic lupus erythematosus patients

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Kittikorn Wangriatisak ◽  
Chokchai Thanadetsuntorn ◽  
Thamonwan Krittayapoositpot ◽  
Chaniya Leepiyasakulchai ◽  
Thanitta Suangtamai ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
Disease Activity ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Systemic Lupus ◽  
Autoreactive B Cells ◽  
Dsdna Antibody ◽  
Cell Subpopulations ◽  
B Cell Subsets

Abstract Background Autoreactive B cells are well recognized as key participants in the pathogenesis of systemic lupus erythematosus (SLE). However, elucidating the particular subset of B cells in producing anti-dsDNA antibodies is limited due to their B cell heterogeneity. This study aimed to identify peripheral B cell subpopulations that display autoreactivity to DNA and contribute to lupus pathogenesis. Methods Flow cytometry was used to detect total B cell subsets (n = 20) and DNA autoreactive B cells (n = 15) in SLE patients’ peripheral blood. Clinical disease activities were assessed in SLE patients using modified SLEDAI-2 K and used for correlation analyses with expanded B cell subsets and DNA autoreactive B cells. Results The increases of circulating double negative 2 (DN2) and activated naïve (aNAV) B cells were significantly observed in SLE patients. Expanded B cell subsets and DNA autoreactive B cells represented a high proportion of aNAV B cells with overexpression of CD69 and CD86. The frequencies of aNAV B cells in total B cell populations were significantly correlated with modified SLEDAI-2 K scores. Further analysis showed that expansion of aNAV DNA autoreactive B cells was more related to disease activity and serum anti-dsDNA antibody levels than to total aNAV B cells. Conclusion Our study demonstrated an expansion of aNAV B cells in SLE patients. The association between the frequency of aNAV B cells and disease activity patients suggested that these expanded B cells may play a role in SLE pathogenesis.

Synovial Infiltration with CD79a-positive B Cells, But Not Other B Cell Lineage Markers, Correlates with Joint Destruction in Rheumatoid Arthritis

2011 ◽  
Vol 38 (11) ◽  
pp. 2301-2308 ◽  
Author(s):  
YING-QIAN MO ◽  
LIE DAI ◽  
DONG-HUI ZHENG ◽  
LANG-JING ZHU ◽  
XIU-NING WEI ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
Disease Activity ◽  
B Cell ◽  
Cell Density ◽  
Joint Destruction ◽  
Chinese Patients ◽  
Positive Staining ◽  
Synovitis Score ◽  
Sharp Score

Objective.The efficacy of B cell depletion in the treatment of patients with rheumatoid arthritis (RA) has revitalized interest in the pathogenic role(s) of B cells in RA. We evaluated the distribution of synovial B lineage cells and their correlation with histologic disease activity and joint destruction in RA.Methods.Synovial tissue samples were obtained by closed-needle biopsy from 69 Chinese patients with active RA, from 14 patients with osteoarthritis (OA), and from 15 with orthopedic arthropathies (OrthA) as disease controls. Serial tissue sections were stained immunohistochemically for CD79a (pro-B cell to plasma cell), CD20 (B cells), CD38 (plasma cells), CD21 (follicular dendritic cells), CD68 (macrophages), CD3 (T cells), and CD34 (endothelial cells). Densities of positive-staining cells were determined and correlated with histologic disease activity (Krenn 3-component synovitis score) and radiographic joint destruction (Sharp score).Results.Mean sublining CD79a-positive cell density was significantly higher in RA than in OA (p <0.001) or OrthA (p = 0.003). Receiver operating characteristic curve analysis showed that CD79a-positive cell density differentiated RA well from OA [area under the curve (AUC) = 0.79] or OrthA (AUC = 0.75). Spearman’s rank order correlation showed significant correlations between sublining CD79a-positive cell density and the synovitis score (r = 0.714, p < 0.001), total Sharp score (r = 0.490, p < 0.001), and the erosion subscore (r = 0.545, p < 0.001), as well as the joint space narrowing subscore (r = 0.468, p = 0.001) in RA.Conclusion.Synovial CD79a-positive B cells may be a helpful biomarker for histologic disease activity in RA and may be involved in the pathogenesis of joint destruction in RA.

scholarly journals The KDM4A/KDM4C/NF-κB and WDR5 epigenetic cascade regulates the activation of B cells

2018 ◽  
Vol 46 (11) ◽  
pp. 5547-5560 ◽  
Author(s):  
Kuo-Hsuan Hung ◽  
Yong H Woo ◽  
I-Ying Lin ◽  
Chin-Hsiu Liu ◽  
Li-Chieh Wang ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Activation ◽  
De Novo ◽  
Epigenetic Mechanism ◽  
B Cell Activation ◽  
Motif Analysis ◽  
Follicular Helper

Abstract T follicular helper (Tfh) cell-derived signals promote activation and proliferation of antigen-primed B cells. It remains unclear whether epigenetic regulation is involved in the B cell responses to Tfh cell-derived signals. Here, we demonstrate that Tfh cell-mimicking signals induce the expression of histone demethylases KDM4A and KDM4C, and the concomitant global down-regulation of their substrates, H3K9me3/me2, in B cells. Depletion of KDM4A and KDM4C potentiates B cell activation and proliferation in response to Tfh cell-derived signals. ChIP-seq and de novo motif analysis reveals NF-κB p65 as a binding partner of KDM4A and KDM4C. Their co-targeting to Wdr5, a MLL complex member promoting H3K4 methylation, up-regulates cell cycle inhibitors Cdkn2c and Cdkn3. Thus, Tfh cell-derived signals trigger KDM4A/KDM4C - WDR5 - Cdkn2c/Cdkn3 cascade in vitro, an epigenetic mechanism regulating proper proliferation of activated B cells. This pathway is dysregulated in B cells from systemic lupus erythematosus patients and may represent a pathological link.

Glucocorticoid-induced leucine zipper (GILZ) inhibits B cell activation in systemic lupus erythematosus

2015 ◽  
Vol 75 (4) ◽  
pp. 739-747 ◽  
Author(s):  
Sarah A Jones ◽  
Andrew E J Toh ◽  
Dragana Odobasic ◽  
Marie-Anne Virginie Oudin ◽  
Qiang Cheng ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Leucine Zipper ◽  
Germinal Centre ◽  
Cell Phenotype ◽  
Systemic Lupus ◽  
Human B Cells

ObjectivesSystemic lupus erythematosus (SLE) is a serious multisystem autoimmune disease, mediated by disrupted B cell quiescence and typically treated with glucocorticoids. We studied whether B cells in SLE are regulated by the glucocorticoid-induced leucine zipper (GILZ) protein, an endogenous mediator of anti-inflammatory effects of glucocorticoids.MethodsWe conducted a study of GILZ expression in blood mononuclear cells of patients with SLE, performed in vitro analyses of GILZ function in mouse and human B cells, assessed the contributions of GILZ to autoimmunity in mice, and used the nitrophenol coupled to keyhole limpet haemocyanin model of immunisation in mice.ResultsReduced B cell GILZ was observed in patients with SLE and lupus-prone mice, and impaired induction of GILZ in patients with SLE receiving glucocorticoids was associated with increased disease activity. GILZ was downregulated in naïve B cells upon stimulation in vitro and in germinal centre B cells, which contained less enrichment of H3K4me3 at the GILZ promoter compared with naïve and memory B cells. Mice lacking GILZ spontaneously developed lupus-like autoimmunity, and GILZ deficiency resulted in excessive B cell responses to T-dependent stimulation. Accordingly, loss of GILZ in naïve B cells allowed upregulation of multiple genes that promote the germinal centre B cell phenotype, including lupus susceptibility genes and genes involved in cell survival and proliferation. Finally, treatment of human B cells with a cell-permeable GILZ fusion protein potently suppressed their responsiveness to T-dependent stimuli.ConclusionsOur findings demonstrated that GILZ is a non-redundant regulator of B cell activity, with important potential clinical implications in SLE.

Steady-state generation of mucosal IgA+ plasmablasts is not abrogated by B-cell depletion therapy with rituximab

Blood ◽  
2010 ◽  
Vol 116 (24) ◽  
pp. 5181-5190 ◽  
Author(s):  
Henrik E. Mei ◽  
Daniela Frölich ◽  
Claudia Giesecke ◽  
Christoph Loddenkemper ◽  
Karin Reiter ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Steady State ◽  
B Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Plasma Cells ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Ki 67

AbstractThe anti-CD20 antibody rituximab depletes human B cells from peripheral blood, but it remains controversial to what extent tissue-resident B cells are affected. In representative patients with rheumatoid arthritis, we here demonstrate that recently activated presumably short-lived plasmablasts expressing HLA-DRhigh and Ki-67 continuously circulate in peripheral blood after B-cell depletion by rituximab at 26%-119% of their initial numbers. They circulate independent of splenectomy, express immunoglobulin A (IgA), β7 integrin, and C-C motif receptor 10 (CCR10) and migrate along CCL28 gradients in vitro, suggesting their mucosal origin. These plasmablasts express somatically hypermutated VH gene rearrangements and spontaneously secrete IgA, exhibiting binding to microbial antigens. Notably, IgA+ plasmablasts and plasma cells were identified in the lamina propria of patients treated with rituximab during peripheral B-cell depletion. Although a relation of these “steady state”–like plasmablasts with rheumatoid arthritis activity could not be found, their persistence during B-cell depletion indicates that their precursors, that is, B cells resident in the mucosa are not deleted by this treatment. These data suggest that a population of mucosal B cells is self-sufficient in adult humans and not replenished by CD20+ B cells immigrating from blood, lymphoid tissue, or bone marrow, that is, B cells depleted by rituximab.

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