scholarly journals Persistent expression of autoantibodies in SLE patients in remission

2006 ◽  
Vol 203 (10) ◽  
pp. 2255-2261 ◽  
Author(s):  
Sergey Yurasov ◽  
Thomas Tiller ◽  
Makoto Tsuiji ◽  
Klara Velinzon ◽  
Virginia Pascual ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Clinical Remission ◽  
B Cell Development ◽  
Cell Compartment ◽  
Healthy Humans ◽  
Polyreactive Antibodies ◽  
Integral Feature ◽  
Active Disease

A majority of the antibodies expressed by nascent B cells in healthy humans are self-reactive, but most of these antibodies are removed from the repertoire during B cell development. In contrast, untreated systemic lupus erythematosus (SLE) patients fail to remove many of the self-reactive and polyreactive antibodies from the naive repertoire. Here, we report that SLE patients in clinical remission continue to produce elevated numbers of self-reactive and polyreactive antibodies in the mature naive B cell compartment, but the number of B cells expressing these antibodies is lower than in patients with active disease. Our finding that abnormal levels of self-reactive mature naive B cells persist in the majority of patients in clinical remission suggests that early checkpoint abnormalities are an integral feature of SLE.

scholarly journals A checkpoint for autoreactivity in human IgM+ memory B cell development

2006 ◽  
Vol 203 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Makoto Tsuiji ◽  
Sergey Yurasov ◽  
Klara Velinzon ◽  
Saskia Thomas ◽  
Michel C. Nussenzweig ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Somatic Hypermutation ◽  
Cell Development ◽  
B Cell Development ◽  
Cell Selection ◽  
Cell Compartment ◽  
Memory B Cell ◽  
Healthy Humans ◽  
Low Levels

Autoantibodies are removed from the repertoire at two checkpoints during B cell development in the bone marrow and the periphery. Despite these checkpoints, up to 20% of the antibodies expressed by mature naive B cells in healthy humans show low levels of self-reactivity. To determine whether self-reactive antibodies are also part of the antigen-experienced memory B cell compartment, we analyzed recombinant antibodies cloned from single circulating human IgM+ memory B cells. Cells expressing antibodies specific for individual bacterial polysaccharides were expanded in the IgM+ memory compartment. In contrast, B cells expressing self-reactive and broadly bacterially reactive antibodies were removed from the repertoire in the transition from naive to IgM+ memory B cell. Selection against self-reactive antibodies was implemented before the onset of somatic hypermutation. We conclude that a third checkpoint selects against self-reactivity during IgM+ memory B cell development in humans.

scholarly journals Functional anergy in a subpopulation of naive B cells from healthy humans that express autoreactive immunoglobulin receptors

2008 ◽  
Vol 206 (1) ◽  
pp. 139-151 ◽  
Author(s):  
J. Andrew Duty ◽  
Peter Szodoray ◽  
Nai-Ying Zheng ◽  
Kristi A. Koelsch ◽  
Qingzhao Zhang ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Plasma Cells ◽  
Cell Subset ◽  
Variable Region ◽  
Cell Receptor ◽  
Clonal Deletion ◽  
Healthy Humans ◽  
Human B Cells

Self-reactive B cells not controlled by receptor editing or clonal deletion may become anergic. We report that fully mature human B cells negative for surface IgM and retaining only IgD are autoreactive and functionally attenuated (referred to as naive IgD+IgM− B cells [BND]). These BND cells typically make up 2.5% of B cells in the peripheral blood, have antibody variable region genes in germline (unmutated) configuration, and, by all current measures, are fully mature. Analysis of 95 recombinant antibodies expressed from the variable genes of single BND cells demonstrated that they are predominantly autoreactive, binding to HEp-2 cell antigens and DNA. Upon B cell receptor cross-linkage, BND cells have a reduced capacity to mobilize intracellular calcium or phosphorylate tyrosines, demonstrating that they are anergic. However, intense stimulation causes BND cells to fully respond, suggesting that these cells could be the precursors of autoantibody secreting plasma cells in autoimmune diseases such as systemic lupus erythematosus or rheumatoid arthritis. This is the first identification of a distinct mature human B cell subset that is naturally autoreactive and controlled by the tolerizing mechanism of functional anergy.

scholarly journals STAT3 positively regulates an early step in B-cell development

Blood ◽  
2006 ◽  
Vol 108 (9) ◽  
pp. 3005-3011 ◽  
Author(s):  
Wei-Chun Chou ◽  
David E. Levy ◽  
Chien-Kuo Lee
Keyword(s):  
B Cells ◽  
B Cell ◽  
Progenitor Cells ◽  
Cell Development ◽  
B Cell Development ◽  
B Lymphopoiesis ◽  
Cell Compartment ◽  
Immature B Cells ◽  
A Cell ◽  
Deficient Mice

Abstract Transcription factors are critical for instructing the development of B lymphocytes from multipotential progenitor cells in the bone marrow (BM). Here, we show that the absence of STAT3 impaired B-cell development. Mice selectively lacking STAT3 in BM progenitor cells displayed reduced numbers of mature B cells, both in the BM and in the periphery. The reduction in the B-cell compartment included reduced percentages and numbers of pro-B, pre-B, and immature B cells in the absence of STAT3, whereas the number of pre–pro-B cells was increased. We found that pro-B and pre-B–cell populations lacking STAT3 were hyporesponsive to IL-7 because of a decreased number of IL-7–responsive cells rather than decreased expression or signaling of IL-7Rα. Moreover, STAT3-deficient mice displayed enhanced apoptosis in the pro-B population when deprived of survival factors, suggesting that at least 2 mechanisms (impaired differentiation and enhanced apoptosis) are involved in the mutant phenotype. Last, BM transplantation confirmed that impaired B lymphopoiesis in the absence of STAT3 was caused by a cell autonomous defect. In sum, these studies defined a specific role for STAT3 in early B-cell development, probably acting at the pre–pro-B transition by contributing to the survival of IL-7–responsive progenitors.

scholarly journals OP0073 SINGLE-CELL TRANSCRIPTOMICS UNCOVERS DEFECTIVE BONE MARROW EARLY B CELL DEVELOPMENT IN A SUBSET OF LUPUS PATIENTS ASSOCIATED WITH AGGRAVATED INFLAMMATION

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 39.2-39
Author(s):  
C. Dong ◽  
X. Gu ◽  
J. Ji ◽  
X. Zhang ◽  
Z. Gu
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Development ◽  
B Cell Development ◽  
Cell Tolerance ◽  
Systemic Lupus ◽  
B Cell Tolerance ◽  
Healthy Donors

Background:Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that occurs when the body’s immune system attacks own tissues and organs. B cells play a central role in SLE pathogenesis by producing autoantibodies as well as antibody-independent functions. Peripheral B cell abnormality is well known in lupus patients such as expansions of plasmablasts and atypical memory B cells, which are associated with active diseases. However, little is known about the B cell development in the bone marrow of lupus patients.Objectives:We conduct this survey to explore the disorder of the B cell development in the bone marrow of lupus patients.Methods:In this study, we have performed the scRNASeq to profile the bone marrow B cell compartment in lupus patients and healthy donors.Results:We identified that in a subset of lupus patients, the early B cells (proB and preB cells) were strongly decreased, which were confirmed by flow cytometry in an expanded cohort. Furthermore, bone marrow B cells from these patients showed a strong proinflammatory signature revealed by pathway analysis. Interestingly, BCR repertoire analysis showed that the IGHV-4-34 was highly enriched in these patients, indicating an enhanced B cell tolerance defect. Finally, a panel of proinflammatory cytokines (TNF-a, IL-1a, IL-12p70, IFN-g, et al.) were strongly increased in the bone marrow plasma of these patients compared with early B normal patients and healthy donors, confirming a localized proinflammatory microenvironment.Conclusion:Altogether, the current study has revealed that a defective early B cell development in lupus patients is associated with a more severe B cell tolerance defect and aggravated inflammation, which may shed new light on developing novel therapies by targeting relevant pathways.References:[1]Min Wang, Hua Chen, Jia Qiu, et al. Antagonizing miR-7 suppresses B cell hyperresponsiveness and inhibits lupus development. J Autoimmun 2020.[2]A M Jacobi, D M Goldenberg, F Hiepe, et al. Differential effects of epratuzumab on peripheral blood B cells of patients with systemic lupus erythematosus versus normal controls. Ann Rheum Dis, 2008.Acknowledgements:This work was funded by Special project of clinical medicine of Nantong University (Grant/Award number: 2019LQ001), National Natural Science Foundation of China (Grant/Award number: 81671616, 81871278 and 82071838).Disclosure of Interests:None declared

scholarly journals The human fetal omentum: a site of B cell generation.

1992 ◽  
Vol 175 (2) ◽  
pp. 397-404 ◽  
Author(s):  
N Solvason ◽  
J F Kearney
Keyword(s):  
B Cells ◽  
B Cell ◽  
Fetal Liver ◽  
Cell Development ◽  
B Cell Development ◽  
Primary Site ◽  
Cell Compartment ◽  
Fetal Mouse ◽  
Time Period ◽  
A Site

The fetal mouse omentum has been shown to be a source of precursors that exclusively reconstitutes Ly1+ B cells and the closely related Ly1- sister population, but not conventional B cells or T cells. We have extended these studies to compare B cell development in the human fetal omentum, liver, and spleen, and to demonstrate that the pro/pre-B cell compartment (CD24+, sIgM-) is detected in the omentum and liver but not spleen as early as 8 wk of gestation. From 8 to 12 wk of gestation, the proportions of IgM+ cells that were pre-B cells (cIgM+/sIgM-) in the omentum and liver were 53 +/- 15% and 45 +/- 13%, respectively, and IgM+ cells were not detectable in the spleen. After 12 wk, the percentage of pre-B cells was unchanged in the fetal liver (41 +/- 10%) but decreased significantly in the omentum (25 +/- 14%); pre-B cells were now detected in the spleen but at much lower percentages (2 +/- 3%) than either the omentum or liver. The nuclear enzyme, Tdt, was detected in approximately 25% of the CD24+ cells in the omentum and liver during the 8-12-wk time period, however, Tdt+ cells were not detected in the spleen. Approximately 40% of the mature B cells found in the omentum and spleen were CD5+ compared with only 20% in the liver. These results demonstrate that the fetal omentum, like the fetal liver and bone marrow, is a primary site of B cell development.

scholarly journals IgG1 B cell receptor signaling is inhibited by CD22 and promotes the development of B cells whose survival is less dependent on Igα/β

2007 ◽  
Vol 204 (4) ◽  
pp. 747-758 ◽  
Author(s):  
Ari Waisman ◽  
Manfred Kraus ◽  
Jane Seagal ◽  
Snigdha Ghosh ◽  
Doron Melamed ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Receptor ◽  
Cell Development ◽  
B Cell Development ◽  
B Cell Receptor ◽  
Cell Physiology ◽  
Cell Compartment ◽  
Heavy Chains

We describe a mouse strain in which B cell development relies either on the expression of membrane-bound immunoglobulin (Ig) γ1 or μ heavy chains. Progenitor cells expressing γ1 chains from the beginning generate a peripheral B cell compartment of normal size with all subsets, but a partial block is seen at the pro– to pre–B cell transition. Accordingly, γ1-driven B cell development is disfavored in competition with developing B cells expressing a wild-type (WT) IgH locus. However, the mutant B cells display a long half-life and accumulate in the mature B cell compartment, and even though partial truncation of the Igα cytoplasmic tail compromises their development, it does not affect their maintenance, as it does in WT cells. IgG1-expressing B cells showed an enhanced Ca2+ response upon B cell receptor cross-linking, which was not due to a lack of inhibition by CD22. The enhanced Ca2+ response was also observed in mature B cells that had been switched from IgM to IgG1 expression in vivo. Collectively, these results suggest that the γ1 chain can exert a unique signaling function that can partially replace that of the Igα/β heterodimer in B cell maintenance and may contribute to memory B cell physiology.

The Dual Bromodomain Protein Brd2 Controls Primary B Cell Mitogenesis and Cell Cycle in Mice Reconstituted with Lentivirus-Transduced HSCs

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2465-2465
Author(s):  
Wanda P. Blanton ◽  
Fangnian Wang ◽  
Hongsheng Liu ◽  
Paul Romesser ◽  
Douglas Faller ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Brdu Incorporation ◽  
Cell Compartment ◽  
Hematopoietic Stem

Abstract Transcriptional control of cellular proliferation and differentiation is critically important in hematopoiesis; specifically, the role of chromatin-dependent regulatory processes in this context is poorly understood. The human BRD2 proto-oncogene encodes a double bromodomain protein that binds to acetylated histone H4 in chromatin and is located within the MHC class II locus, suggesting Brd2 plays a role in immunity. However, BRD2 shares no sequence similarity with other MHC genes, nor is Brd2 involved in antigen processing, but rather it plays a role in mitogenic signal transduction. We have previously found that whole-body knockout of Brd2 is lethal to mice. However, when Brd2 was expressed constitutively in the B cells of transgenic mice, Brd2 binds E2F proteins, histone acetylases and Swi/Snf complexes, and co-activates cyclin A leading to B cell lymphoma and leukemia. Importantly, elevated levels of Brd2 have been reported in primary malignant B cells from human and mouse. We therefore hypothesize that Brd2 multiprotein complexes, working through chromatin modification, are crucial in the control of the cell cycle and in the mitogen responsiveness and proliferation of the B cell compartment. To study the effects of Brd2 in B cell development and proliferation, we performed bone marrow transplants of hematopoietic stem cells in a chimeric mouse model. Hematopoietic stem cells were sorted from CD45.1 donor mice with the characteristic ‘side population’ profile by flow cytometry and transduced with lentivirus containing vectors for Brd2 overexpression, shRNA knockdown, or control vectors. Recipient CD45.2 mice were lethally irradiated and a functional immune system was successfully reconstituted with donor cells and CD45.2 competitor BM cells. Mice were immunophenotyped and functional B cell mitogenic capacity was examined by BrdU incorporation into LPS-stimulated B cells. We found that in the spleen, Brd2 expression dramatically expands the CD45.1 (but not CD45.2) B cell compartment at the expense of T cells and renders B cells mitogenically hypersensitive. Compared with control, there was an increase in BrdU incorporation at 24 and 48 hours (29.8% v. 43.5% at T=24 h; 56.9% v. 66.7% at T=48 h). Preliminary results also suggest that B cell development was skewed in the bone marrow and periphery towards B1a phenotype. Moreover, downregulation of Brd2 via shRNA blocked cyclin A transcription and completely arrested B cell development and proliferation. Taken together, these data suggest that Brd2, through epigenetic regulation of the cell cycle, plays an important role in B-lymphopoiesis, proliferation, and stimulation.

scholarly journals THU0044 SINGLE CELL ANALYSIS OF BONE MARROW AND PERIPHERAL ALTERED B CELL DIFFERENTIATION IN PATIENTS WITH ACTIVE SLE AND THE MECHANISM OF ABNORMAL EARLY B CELL DEVELOPMENT

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 234.3-235
Author(s):  
T. Fu ◽  
Y. Yang ◽  
X. Gu ◽  
C. Dong ◽  
R. Zhao ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
Cell Development ◽  
B Cell Development ◽  
B Cell Differentiation ◽  
Systemic Lupus ◽  
B Cell Subsets

Background:B cell differentiation and dysfunction play a key role in the pathogenesis of Systemic lupus erythematosus (SLE). Bone marrow (BM) is the development organ of B cells, and also the home and residence place of plasma cells and memory B cells. However, there is a lack of studies on B cells in BM with lupus.Objectives:To map the development of BM and peripheral B cells and investigate the mechanism of abnormal early B cell development in SLE.Methods:A total of 11 SLE patients and 5 age- and sex-matched controls were recruited.BM and peripheral B cell subsets were measured by flow cytometry. sorting-purified B cell subsets were subject toSingle-cell RNA sequencing (scRNA-seq) and functional studies. Plasma cytokines and secreted immunoglobulins were detected by Luminex or ELISA. Disease activity of SLE patients was measured using the SLE Disease Activity Index (SLEDAI).Results:In the present study, we find out that the percentage of monocytes in MNC (p=0.070) and plasma cells(p=0.001)in CD19+ were significantly decreased in BM of SLE, compared to healthy controls. While, SLE patients had increased T%MNC(p=0.008) and B%CD19+(p=0.002) in BM that controls. In detail, the B cell subsets of bone marrow in patients with active lupus (SLEDAI≥8 score) were seriously disordered, showing the increasing T%MNC(p=0.049), propre-B%CD19+ (p=0.006)and immature B cell%CD19+ (p=0.010) than healthy donors. propre-B%CD19+ exhibited good relationship with SLEDAI. By integrating single B cell expression profiling and repertoire analysis, we map the development of B cells in BM and peripheral and pathogenic characteristics of early B cells, especially propre-B.Conclusion:These findings demonstrated that early B cells in BM, especially propre-B are abnormally differentiated with dysregulations. BM is an important organ targeted by SLE. This studyis not only to clarify the internal mechanism of the disorder of differentiation of B cells, but also to provide new clues for the targeted diagnosis and treatment of SLE.References:[1]Palanichamy, A., et al.,Neutrophil-mediated IFN activation in the bone marrow alters B cell development in human and murine systemic lupus erythematosus.J Immunol, 2014.192(3): p. 906-18.[2]Papadaki, H.A., J.C. Marsh, and G.D. Eliopoulos,Bone marrow stem cells and stromal cells in autoimmune cytopenias.Leuk Lymphoma, 2002.43(4): p. 753-60.[3]Karrar, S. and D.S. Cunninghame Graham,Abnormal B Cell Development in Systemic Lupus Erythematosus: What the Genetics Tell Us.Arthritis Rheumatol, 2018.70(4): p. 496-507.[4]Woods, M., Y.R. Zou, and A. Davidson,Defects in Germinal Center Selection in SLE.Front Immunol, 2015.6: p. 425.[5]Upregulation of p16INK4A promotes cellular senescence of bone marrow-derived mesenchymal stem cells from systemic lupus erythematosus patients.Cell Signal, 2012.24(12): p. 2307-14.Disclosure of Interests:None declared

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