scholarly journals Bm1–Bm5 Classification of Peripheral Blood B Cells Reveals Circulating Germinal Center Founder Cells in Healthy Individuals and Disturbance in the B Cell Subpopulations in Patients with Primary Sjögren’s Syndrome

2001 ◽  
Vol 167 (7) ◽  
pp. 3610-3618 ◽  
Author(s):  
Janne Ø. Bohnhorst ◽  
Marie B. Bjørgan ◽  
Jørn E. Thoen ◽  
Jacob B. Natvig ◽  
Keith M. Thompson
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Peripheral Blood ◽  
Primary Sjögren’S Syndrome ◽  
Healthy Individuals ◽  
Primary Sjogren’S Syndrome ◽  
Founder Cells ◽  
Cell Subpopulations

scholarly journals Identification of novel genes associated with dysregulation of B cells in patients with primary Sjögren's syndrome

2020 ◽  
Author(s):  
Jun Inamo ◽  
Katsuya Suzuki ◽  
Masaru Takeshita ◽  
Yoshiaki Kassai ◽  
Maiko Takiguchi ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Primary Sjögren’S Syndrome ◽  
Primary Sjogren’S Syndrome ◽  
Primary Sjögren's Syndrome ◽  
Cell Subpopulations ◽  
B Cell Subsets ◽  
Sjögren‘S Syndrome

Abstract Background. The aim of this study was to identify the molecular mechanism of dysregulation of B cell subpopulations of primary Sjögren's syndrome (pSS) at the transcriptome level. Methods. We enrolled patients with pSS (n=6) and healthy controls (HC) (n=6) in the discovery cohort using microarray and pSS (n=14) and HC (n=12) in the validation cohort using quantitative PCR (qPCR). Peripheral B cells acquired from these subjects were separated by cell sorting into four subsets: CD38-IgD+ (Bm1), CD38+IgD+ (naïve B cells), CD38highIgD+ (pre-germinal centre B cells) and CD38±IgD- (memory B cells). We performed differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA).Results. Expression of the long non-coding RNA LINC00487 was significantly upregulated in all B cell subsets, as was that of HLA and interferon (IFN) signature genes. Moreover, the normalized intensity value of LINC00487 significantly correlated with the disease activity score of all pSS B cell subsets. Studies of human B cell lines revealed that the expression of LINC00487 was strongly induced by IFNα. WGCNA revealed six gene clusters associated with the B cell subpopulation of pSS. Further, SOX4 was identified as an inter-module hub gene.Conclusion. Our transcriptome analysis revealed key genes involved in the dysregulation of B cell subpopulations associated with pSS. Trial registration: Not required.

scholarly journals Identification of novel genes associated with dysregulation of B cells in patients with primary Sjögren's syndrome

2020 ◽  
Author(s):  
Jun Inamo ◽  
Katsuya Suzuki ◽  
Masaru Takeshita ◽  
Yoshiaki Kassai ◽  
Maiko Takiguchi ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Primary Sjögren’S Syndrome ◽  
Primary Sjogren’S Syndrome ◽  
Primary Sjögren's Syndrome ◽  
Cell Subpopulations ◽  
B Cell Subsets ◽  
Sjögren‘S Syndrome

Abstract Background. The aim of this study was to identify the molecular mechanism of dysregulation of B cell subpopulations of primary Sjögren's syndrome (pSS) at the transcriptome level. Methods. We enrolled patients with pSS (n=6) and healthy controls (HC) (n=6) in the discovery cohort using microarray and pSS (n=14) and HC (n=12) in the validation cohort using quantitative PCR (qPCR). Peripheral B cells acquired from these subjects were separated by cell sorting into four subsets: CD38-IgD+ (Bm1), CD38+IgD+ (naïve B cells), CD38highIgD+ (pre-germinal centre B cells) and CD38±IgD- (memory B cells). We performed differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA).Results. Expression of the long non-coding RNA LINC00487 was significantly upregulated in all B cell subsets, as was that of HLA and interferon (IFN) signature genes. Moreover, the normalized intensity value of LINC00487 significantly correlated with the disease activity score of all pSS B cell subsets. Studies of human B cell lines revealed that the expression of LINC00487 was strongly induced by IFNα. WGCNA revealed six gene clusters associated with the B cell subpopulation of pSS. Further, SOX4 was identified as an inter-module hub gene.Conclusion. Our transcriptome analysis revealed key genes involved in the dysregulation of B cell subpopulations associated with pSS.

scholarly journals Identification of novel genes associated with dysregulation of B cells in patients with primary Sjögren's syndrome

2020 ◽  
Author(s):  
Jun Inamo ◽  
Katsuya Suzuki ◽  
Masaru Takeshita ◽  
Yoshiaki Kassai ◽  
Maiko Takiguchi ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Primary Sjögren’S Syndrome ◽  
Primary Sjogren’S Syndrome ◽  
Primary Sjögren's Syndrome ◽  
Cell Subpopulations ◽  
B Cell Subsets ◽  
Sjögren‘S Syndrome

Abstract Background The aim of this study was to identify at the transcriptome level the molecular mechanism of dysregulation of B cell subpopulations of primary Sjögren's syndrome (pSS). Methods We enrolled patients with pSS (n=6) and healthy controls (HC) (n=6) in the discovery cohort using microarray and pSS (n=14) and HC (n=12) in the validation cohort using quantitative PCR (qPCR). Peripheral B cells acquired from these subjects were separated by cell sorting into four subsets: CD38 - IgD + (Bm1), CD38 + IgD + (naïve B cells), CD38 high IgD + (pre-germinal centre B cells) and CD38 ± IgD - (memory B cells). Results Expression of the long non-coding RNA LINC00487 was significantly upregulated in all B cell subsets, as was that of HLA and interferon (IFN) signature genes. Moreover, the normalized intensity value of LINC00487 significantly correlated with the disease activity score of all pSS B cell subsets. Studies of human B cell lines revealed that the expression of LINC00487 was strongly induced by IFNα. Weighted gene co-expression network analysis revealed six gene clusters associated with the B cell subpopulation of pSS. Further, SOX4 was identified as an inter-module hub gene. ConclusionOur transcriptome analysis revealed key genes involved in the dysregulation of B cell subpopulations associated with pSS.

scholarly journals Arhgap25 deficiency leads to decreased numbers of peripheral blood B cells and defective germinal center reactions

2020 ◽  
Author(s):  
Silke E. Lindner ◽  
Colt A. Egelston ◽  
Stephanie M. Huard ◽  
Peter P. Lee ◽  
Leo D. Wang
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Peripheral Blood ◽  
Cell Development ◽  
B Cell Development ◽  
Dependent Manner ◽  
B Cell Differentiation ◽  
Nucleotide Exchange

ABSTRACTRho family GTPases are critical for normal B cell development and function and their activity is regulated by a large and complex network of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). However, the role of GAPs in B cell development is poorly understood. Here we show that the novel Rac-GAP ARHGAP25 is important for B cell development in mice in a CXCR4-dependent manner. We show that Arhgap25 deficiency leads to a significant decrease in peripheral blood B cell numbers, as well as defects in mature B cell differentiation. Arhgap25-/- B cells respond to antigen stimulation in vitro and in vivo but have impaired germinal center formation and decreased IgG1 class switching. Additionally, Arhgap25-/- B cells exhibit increased chemotaxis to CXCL12. Taken together, these studies demonstrate an important role for Arhgap25 in peripheral B cell development and antigen response.

scholarly journals Expression of TLR10 in B cells Correlates With Primary Sjögren’s Syndrome Progression

2021 ◽  
Author(s):  
Nannan Lai ◽  
YiChao Qian ◽  
Yilin Wu ◽  
Xi Jiang ◽  
Honghua Sun ◽  
...  
Keyword(s):  
B Cells ◽  
Disease Activity ◽  
B Cell ◽  
High Activity ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Primary Sjögren’S Syndrome ◽  
Memory B Cells ◽  
Primary Sjogren’S Syndrome ◽  
Primary Sjögren's Syndrome

Abstract Primary Sjögren’s Syndrome (pSS) is considered a B cell-mediated disease, yet the precise role of B cells in the pathogenesis is not fully understood. Toll-like receptor 10 (TLR10) is highly expressed in human B cells, indicating that TLR10 probably plays a vital role in regulating B cell function as well as B cell-related diseases. However, the biology of TLR10 in pSS was rarely researched. Here, we examined the TLR10 expression in peripheral B cell subsets isolated from both pSS patients and healthy controls (HCs) and further analyzed the correlations between TLR10 expression and disease activity. We observed that TLR10 expression in peripheral total CD19+ B cells, naïve B cells (CD19+CD27-IgD+) and switched memory B cells (CD19+CD27+IgD-) was significantly increased in low-activity pSS patients as compared with HCs and high-activity pSS patients. TLR10 expression in total and switched memory B cells in pSS patients was significantly negatively correlated with serum levels of anti-SSA antibody and B cell activating factor of TNF family (BAFF). As compared with the TLR10 low-, the TLR10 high-expressed pSS patients presented with reduced switched memory B cells. Moreover, a much lower proportion of high-activity pSS patients was observed in TLR10 high- as compared to low-expressed patients. Our study concluded that TLR10 expression in peripheral total and switched memory B is negatively correlated with pSS disease activity, suggesting that TLR10 might suppress pSS progression via inhibiting the B cell class switch recombination. These results should contribute to the diagnosis and treatment of pSS.

Differential Expression and Non-Redundant Functions of NF-κB Transcription Factor Subunits in Germinal Center (GC) B Cell Subpopulations

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 216-216 ◽  
Author(s):  
Nicole Heise ◽  
Nilushi De Silva ◽  
Amanda Carette ◽  
Giorgia Simonetti ◽  
Govind Bhagat ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Differential Expression ◽  
Plasma Cell ◽  
Germinal Center ◽  
Plasma Cells ◽  
Nuclear Translocation ◽  
Cell Subpopulations

Abstract Abstract 216 The majority of B cell-derived neoplasms, including Hodgkin and Non-Hodgkin lymphoma and multiple myeloma (MM), arise from antigen-specific B cells that have undergone the germinal center (GC) reaction of T-dependent immune responses. Recent work has demonstrated that GC-derived tumors frequently harbor genetic mutations in nuclear factor-κB (NF-κB) signaling pathway components, resulting in the constitutive activation of NF-κB signaling, thus identifying NF-κB as a critical player in GC-lymphomagenesis. Moreover, there is evidence for a preferential activation of particular NF-κB transcription factor subunits in tumor subtypes. Despite extensive knowledge about the biology of NF-κB, its potential function in the physiology and development of GC B cells, the presumptive tumor precursor cells, is largely unresolved. The NF-κB signaling cascade comprises 5 different subunits, which occur as homo- and heterodimers and can be activated via two different routes, the canonical (classical) and the alternative (non-canonical/classical) NF-κB pathways. RELA, c-REL and p105/p50 represent the subunits of the canonical, while RELB and p100/p52 comprise those of the alternative pathway. It is known that there is no active NF-κB signaling in tonsillar GC centroblasts. Conversely, NF-κB activation was shown to occur in a subset of GC centrocytes. In this study, we demonstrate that each of the 5 NF-κB subunits exhibit nuclear translocation in centrocytes. Surprisingly, we observed that centrocytes expressing the plasma cell master regulator BLIMP1 showed strong immunofluorescence (IF) staining for the alternative NF-κB subunit p100/p52 and weak expression of the canonical subunits p105/p50 and c-REL compared to surrounding lymphocytes. Plasma cells localized in the tonsillar subepithelium showed the same pattern of expression. This observed differential expression of alternative vs. canonical NF-κB subunits in plasma cells and B cells, respectively, is supported by gene expression profiling data of human B cell subpopulations. Moreover, we observed that a mouse lymphoma cell line (M12) shows activation of the alternative NF-κB pathway upon induction of plasma cell differentiation. Also, Western and IF analysis of MM vs. diffuse large B cell lymphoma (DLBCL) cell lines revealed high protein levels and nuclear translocation of both p52 and RELB and low levels and cytosolic localization of c-REL in MM cell lines, while the opposite pattern was observed in the analyzed DLBCL lines. In summary, the elevated protein expression and presumed activity of the alternative over the canonical NF-κB pathway in plasma cells and their precursors suggests that activation of the alternative NF-κB pathway in centrocytes may contribute to plasma cell development and/or physiology. To elucidate the in vivo function of individual NF-κB transcription factor subunits, we started by determining the extent to which deletion of c-REL specifically in GC B cells affects the biology and differentiation of GC and post-GC B cells. We generated and then crossed a conditional loxP-flanked rel (c-REL) allele to mice that express the Cre-recombinase in GC B cells instructed to undergo class switch recombination (Cγ1-Cre mice). Following immunization with a T-dependent antigen, PNA+CD95+ GC B cell numbers were markedly reduced in immunized relfl/flCγ1-Cre mice compared to rel+/+Cγ1-Cre control mice. In addition, immunohistochemical analysis of spleen sections for BCL6 and IgG1 showed significantly smaller GCs, and a strong reduction in the numbers of GC-derived IgG1-secreting plasma cells, in relfl/flCγ1-Cre mice compared to controls. Consistent with these findings, we observed that relfl/flCγ1-Cre mice showed dramatically reduced numbers of nitrophenyl (NP) hapten-specific cells 14 days after immunization with NP-KLH compared to the control mice. Taken together, these findings suggest that c-REL may be required for the maintenance of GC B cells or for their selection into the post-GC compartment. Of note, the results demonstrate that deletion of a single NF-κB subunit in GC B cells can have drastic effects, suggesting a lack of general redundancy of the canonical subunits during the GC reaction. These findings imply that c-REL activation needs to be tightly controlled during GC B cell development, and raise the possibility that other NF-κB subunits may also exert unique functions in GC B cell differentiation. Disclosures: No relevant conflicts of interest to declare.

scholarly journals POS0177 POTENTIAL INVOLVEMENT OF IL-40 AND IL-40-PRODUCING CELLS IN PRIMARY SJOGREN’S SYNDROME (pSS) AND pSS-ASSOCIATED LYMPHOMA

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 301.2-302
Author(s):  
C. Rizzo ◽  
M. Lo Pizzo ◽  
L. Mohammadnezhad ◽  
V. L. Lentini ◽  
D. Di Liberto ◽  
...  
Keyword(s):  
T Cells ◽  
Salivary Gland ◽  
B Cells ◽  
B Cell ◽  
Salivary Glands ◽  
Primary Sjögren’S Syndrome ◽  
Parotid Glands ◽  
Primary Sjogren’S Syndrome ◽  
Primary Sjögren's Syndrome ◽  
Focus Score

Background:The pathogenesis of pSS relies on a complex interplay between both innate and adaptive immune responses in which B cells play a pivotal role. Their chronic aberrant hyperactivation may drive clonal escape and consequent lymphomagenesis [1]. In the last few years, B cells have emerged as potential effector cells, able to release a wide range of cytokines that actively contribute to shape the microenvironment they act in. Recently, IL-40, a novel B cell associated cytokine encoded by an uncharacterized gene (C17orf99; chromosome 17 open reading frame 99) was described. Naïve B cells can express IL-40 at both tissue and peripheral level and the stimulation of B cells with IL-4 and TGF-β significantly increases IL-40 release. In addition, human B cells lymphomas are able to constitutively produce IL-40 [2]. Taking into account this emerging evidence and considering the well-known role of IL-4 and TGF-β in pSS pathogenesis, as well as the association with lymphomas, we decided to focus our attention on IL-40 in pSS patients.Objectives:The aim of the present study was to investigate IL-40 expression in the salivary glands of patients affected by pSS and pSS-associated non-Hodgkin’s lymphoma (NHL).Methods:Minor salivary gland biopsies were obtained from 22 patients with pSS and 12 patients with non-specific chronic sialoadenitis (nSCS), included as controls. Paraffine-embedded samples of parotid glands from patients with a previous diagnosis of pSS-associated NHL (n=10) were selected from the biopsy bank of the Pathology Unit of the Ospedale Cervello (Palermo, Italy). Quantitative gene expression analysis by TaqMan real-time PCR and immunohistochemistry (IHC) for IL-40, IL-4, TGF-β1 was performed on salivary glands from patients and controls. The cellular sources of IL-40 among infiltrating inflammatory cells were determined by fluorescence-activated cell sorting (FACS) analysis and immunofluorescence (IF). Serum IL-40 levels were measured by ELISA in both patients (n=10) and controls (n=9).Results:IL-40 was significantly increased at both protein and mRNA level in the inflamed salivary glands of patients with pSS where a positive strong correlation between the IL-40 mRNA levels and the focus score (FS) was evidenced. The expression of IL-40 in parotid glands of pSS-associated NHL was also markedly increased (Figure 1). IL-40 expression correlated with the presence of IL-4 and TGF-β; both cytokines were significantly increased in pSS at mRNA and protein level. Among infiltrating immune cells, CD19+ B cells resulted the major source of IL-40. However, we identified CD4+, CD8+ T cells and CD68+ macrophages as additional producers of IL-40 in both FACS and IF analysis. The ELISA test also showed a significant increase of serum IL-40 concentration in pSS patients (p value = 0.0190), compared to controls.Conclusion:Our preliminary results suggest that IL-40 may play a role in the pathogenesis of pSS and pSS-associated NHL. To the best of our knowledge, this is the first demonstration of the overexpression of this cytokine in salivary gland tissue and sera in pSS. Moreover, we demonstrated that IL-40 is produced by several cellular types, such as T cells and macrophages, and is not exclusively released by B cells. Further studies are necessary to clarify IL-40 pathways and functions in order to unravel IL-40 possible role in pSS development.References:[1]Mariette X, Criswell LA. Primary Sjogren’s Syndrome. N Engl J Med. 2018;379(1):97.[2]Catalan-Dibene J, Vazquez MI, Luu VP, Nuccio SP, Karimzadeh A, Kastenschmidt JM, et al. Identification of IL-40, a Novel B Cell-Associated Cytokine. J Immunol. 2017;199(9):3326-35.Figure 1.IL-40 overexpression in pSS and pSS-associated lymphoma A, Salivary gland biopsies stained for IL-40 showing a marked increase in IL-40 expression in presence of higher focus score. B, Parotid gland specimens of pSS-associated lymphoma showing intense staining for IL-40.Disclosure of Interests:Chiara Rizzo: None declared, Marianna Lo Pizzo: None declared, Leila Mohammadnezhad: None declared, Vincenzo Luca Lentini: None declared, Diana Di Liberto: None declared, Giulia Grasso: None declared, Piero Ruscitti Consultant of: Pfizer, Novartis, Celgene, Abbvie, Roche, Lilly, Rorberto Giacomelli Consultant of: Pfizer, Novartis, Celgene, Abbvie, Roche, Lilly, francesco ciccia Consultant of: Pfizer, Novartis, Celgene, Abbvie, Roche, Lilly, Giuliana Guggino Consultant of: Pfizer, Novartis, Celgene, Abbvie, Roche, Lilly

scholarly journals The Imbalance of Circulating Follicular T Helper Cell Subsets in Primary Sjögren’s Syndrome Associates With Serological Alterations and Abnormal B-Cell Distribution

2021 ◽  
Vol 12 ◽  
Author(s):  
Krisztina Szabó ◽  
Ilona Jámbor ◽  
Antónia Szántó ◽  
Ildikó Fanny Horváth ◽  
Tünde Tarr ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Primary Sjögren’S Syndrome ◽  
Healthy Controls ◽  
T Helper ◽  
Primary Sjogren’S Syndrome ◽  
Primary Sjögren's Syndrome ◽  
Sjögren‘S Syndrome

Since B-cell hyperactivity and pathologic antibody response are key features in the immunopathogenesis of primary Sjögren’s syndrome (pSS), the role of follicular T helper (TFH) cells as efficient helpers in the survival and differentiation of B cells has emerged. Our aim was to investigate whether a change in the balance of circulating (c)TFH subsets and follicular regulatory T (TFR) cells could affect the distribution of B cells in pSS. Peripheral blood of 38 pSS patients and 27 healthy controls was assessed for the frequencies of cTFH cell subsets, TFR cells, and certain B cell subpopulations by multicolor flow cytometry. Serological parameters, including anti-SSA, anti-SSB autoantibodies, immunoglobulin, and immune complex titers were determined as part of the routine diagnostic evaluation. Patients with pSS showed a significant increase in activated cTFH cell proportions, which was associated with serological results. Frequencies of cTFH subsets were unchanged in pSS patients compared to healthy controls. The percentages and number of cTFR cells exhibited a significant increase in autoantibody positive patients compared to patients with seronegative pSS. The proportions of transitional and naïve B cells were significantly increased, whereas subsets of memory B cells were significantly decreased and correlated with autoantibody production. Functional analysis revealed that the simultaneous blockade of cTFH and B cell interaction with anti-IL-21 and anti-CD40 antibodies decreased the production of IgM and IgG. Imbalance in TFH subsets and TFR cells indicates an ongoing over-activated humoral immune response, which contributes to the characteristic serological manifestations and the pathogenesis of pSS.

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