scholarly journals B-cell tolerance and autoimmunity

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 391 ◽  
Author(s):  
Takeshi Tsubata

Self-reactive B cells are tolerized at various stages of B-cell development and differentiation, including the immature B-cell stage (central tolerance) and the germinal center (GC) B-cell stage, and B-cell tolerance involves various mechanisms such as deletion, anergy, and receptor editing. Self-reactive B cells generated by random immunoglobulin variable gene rearrangements are tolerized by central tolerance and anergy in the periphery, and these processes involve apoptosis regulated by Bim, a pro-apoptotic member of the Bcl-2 family, and regulation of B-cell signaling by various phosphatases, including SHIP-1 and SHP-1. Self-reactive B cells generated by somatic mutations during GC reaction are also eliminated. Fas is not directly involved in this process but prevents persistence of GC reaction that allows generation of less stringently regulated B cells, including self-reactive B cells. Defects in self-tolerance preferentially cause lupus-like disease with production of anti-nuclear antibodies, probably due to the presence of a large potential B-cell repertoire reactive to nucleic acids and the presence of nucleic acid-induced activation mechanisms in various immune cells, including B cells and dendritic cells. A feed-forward loop composed of anti-nuclear antibodies produced by B cells and type 1 interferons secreted from nucleic acid-activated dendritic cells plays a crucial role in the development of systemic lupus erythematosus.

2019 ◽  
Vol 216 (5) ◽  
pp. 1135-1153 ◽  
Author(s):  
Sarah A. Greaves ◽  
Jacob N. Peterson ◽  
Pamela Strauch ◽  
Raul M. Torres ◽  
Roberta Pelanda

Autoreactive B cells that bind self-antigen with high avidity in the bone marrow undergo mechanisms of central tolerance that prevent their entry into the peripheral B cell population. These mechanisms are breached in many autoimmune patients, increasing their risk of B cell–mediated autoimmune diseases. Resolving the molecular pathways that can break central B cell tolerance could therefore provide avenues to diminish autoimmunity. Here, we show that B cell–intrinsic expression of a constitutively active form of PI3K-P110α by high-avidity autoreactive B cells of mice completely abrogates central B cell tolerance and further promotes these cells to escape from the bone marrow, differentiate in peripheral tissue, and undergo activation in response to self-antigen. Upon stimulation with T cell help factors, these B cells secrete antibodies in vitro but remain unable to secrete autoantibodies in vivo. Overall, our data demonstrate that activation of the PI3K pathway leads high-avidity autoreactive B cells to breach central, but not late, stages of peripheral tolerance.


1998 ◽  
Vol 188 (5) ◽  
pp. 909-917 ◽  
Author(s):  
Jennifer A. Kench ◽  
David M. Russell ◽  
David Nemazee

Peripheral B cell tolerance was studied in mice of the autoimmune-prone, Fas-deficient MRL/ lpr.H-2d genetic background by introducing a transgene that directs expression of membrane-bound H-2Kb antigen to liver and kidney (MT-Kb) and a second transgene encoding antibody reactive with this antigen (3-83μδ, anti-Kk,b). Control immunoglobulin transgenic (Ig-Tg) MRL/lpr.H-2d mice lacking the Kb antigen had large numbers of splenic and lymph node B cells bearing the transgene-encoded specificity, whereas B cells of the double transgenic (Dbl-Tg) MRL/lpr.H-2d mice were deleted as efficiently as in Dbl-Tg mice of a nonautoimmune B10.D2 genetic background. In spite of the severely restricted peripheral B cell repertoire of the Ig-Tg MRL/lpr.H-2d mice, and notwithstanding deletion of the autospecific B cell population in the Dbl-Tg MRL/lpr.H-2d mice, both types of mice developed lymphoproliferation and exhibited elevated levels of IgG anti-chromatin autoantibodies. Interestingly, Dbl-Tg MRL/lpr.H-2d mice had a shorter lifespan than Ig-Tg MRL/lpr.H-2d mice, apparently as an indirect result of their relative B cell lymphopenia. These data suggest that in MRL/lpr mice peripheral B cell tolerance is not globally defective, but that certain B cells with receptors specific for nuclear antigens are regulated differently than are cells reactive to membrane autoantigens.


2005 ◽  
Vol 202 (3) ◽  
pp. 341-344 ◽  
Author(s):  
Annett M. Jacobi ◽  
Betty Diamond

The autoimmune disease systemic lupus erythematosus (SLE) is caused by a failure of B cell tolerance. Recent studies in mouse models of SLE have identified several distinct tolerance checkpoints that must each function appropriately to protect against disease. However, studies of B cell repertoire selection in humans are essential to understand which checkpoints are defective in human autoimmune diseases.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 39.2-39
Author(s):  
C. Dong ◽  
X. Gu ◽  
J. Ji ◽  
X. Zhang ◽  
Z. Gu

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


2005 ◽  
Vol 201 (5) ◽  
pp. 703-711 ◽  
Author(s):  
Sergey Yurasov ◽  
Hedda Wardemann ◽  
Johanna Hammersen ◽  
Makoto Tsuiji ◽  
Eric Meffre ◽  
...  

A cardinal feature of systemic lupus erythematosus (SLE) is the development of autoantibodies. The first autoantibodies described in patients with SLE were those specific for nuclei and DNA, but subsequent work has shown that individuals with this disease produce a panoply of different autoantibodies. Thus, one of the constant features of SLE is a profound breakdown in tolerance in the antibody system. The appearance of self-reactive antibodies in SLE precedes clinical disease, but where in the B cell pathway tolerance is first broken has not been defined. In healthy humans, autoantibodies are removed from the B cell repertoire in two discrete early checkpoints in B cell development. We found these checkpoints to be defective in three adolescent patients with SLE. 25–50% of the mature naive B cells in SLE patients produce self-reactive antibodies even before they participate in immune responses as compared with 5–20% in controls. We conclude that SLE is associated with abnormal early B cell tolerance.


1995 ◽  
Vol 181 (3) ◽  
pp. 1157-1167 ◽  
Author(s):  
J H Roark ◽  
C L Kuntz ◽  
K A Nguyen ◽  
A J Caton ◽  
J Erikson

Anti-DNA antibodies, specifically those that stain nuclei in a homogenous nuclear (HN) fashion, are diagnostic of systemic lupus erythematosus (SLE) and the MRL-lpr/lpr SLE murine model. We have used a heavy chain transgene that increases the frequency of anti-HN antibodies to address whether their production in SLE is the consequence of a defect in B cell tolerance. Anti-HN B cells were undetectable in nonautoimmune-prone transgenic mice, but in MRL-lpr/lpr transgenic mice their Ig was evident in the sera and they were readily retrievable as hybridomas. We conclude that nonautoimmune animals actively delete anti-HN-specific B cells, and that MRL-lpr/lpr mice are defective in this process possibly because of the lpr defect in the fas gene.


2007 ◽  
Vol 204 (8) ◽  
pp. 1959-1971 ◽  
Author(s):  
Joanna R. Groom ◽  
Carrie A. Fletcher ◽  
Stacey N. Walters ◽  
Shane T. Grey ◽  
Sally V. Watt ◽  
...  

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of autoantibodies. However, the underlying cause of disease appears to relate to defects in T cell tolerance or T cell help to B cells. Transgenic (Tg) mice overexpressing the cytokine B cell–activating factor of the tumor necrosis factor family (BAFF) develop an autoimmune disorder similar to SLE and show impaired B cell tolerance and altered T cell differentiation. We generated BAFF Tg mice that were completely deficient in T cells, and, surprisingly, these mice developed an SLE-like disease indistinguishable from that of BAFF Tg mice. Autoimmunity in BAFF Tg mice did, however, require B cell–intrinsic signals through the Toll-like receptor (TLR)–associated signaling adaptor MyD88, which controlled the production of proinflammatory autoantibody isotypes. TLR7/9 activation strongly up-regulated expression of transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), which is a receptor for BAFF involved in B cell responses to T cell–independent antigens. Moreover, BAFF enhanced TLR7/9 expression on B cells and TLR-mediated production of autoantibodies. Therefore, autoimmunity in BAFF Tg mice results from altered B cell tolerance, but requires TLR signaling and is independent of T cell help. It is possible that SLE patients with elevated levels of BAFF show a similar basis for disease.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yan Wang ◽  
Katy A. Lloyd ◽  
Ioannis Melas ◽  
Diana Zhou ◽  
Radha Thyagarajan ◽  
...  

AbstractB cells are postulated to be central in seropositive rheumatoid arthritis (RA). Here, we use exploratory mass cytometry (n = 23) and next-generation sequencing (n = 19) to study B-cell repertoire shifts in RA patients. Expression of several B-cell markers were significantly different in ACPA+ RA compared to healthy controls, including an increase in HLA-DR across subsets, CD22 in clusters of IgM+ B cells and CD11c in IgA+ memory. Moreover, both IgA+ and IgG+ double negative (IgD− CD27−) CD11c+ B cells were increased in ACPA+ RA, and there was a trend for elevation in a CXCR5/CCR6high transitional B-cell cluster. In the RA BCR repertoire, there were significant differences in subclass distribution and, notably, the frequency of VH with low somatic hypermutation (SHM) was strikingly higher, especially in IgG1 (p < 0.0001). Furthermore, both ACPA+ and ACPA− RA patients had significantly higher total serum IgA and IgM compared to controls, based on serology of larger cohorts (n = 3494 IgA; n = 397 IgM). The observed elevated Ig-levels, distortion in IgM+ B cells, increase in double negative B cells, change in B-cell markers, and elevation of unmutated IgG+ B cells suggests defects in B-cell tolerance in RA. This may represent an underlying cause of increased polyreactivity and autoimmunity in RA.


2010 ◽  
Vol 207 (7) ◽  
pp. 1541-1554 ◽  
Author(s):  
Jolan E. Walter ◽  
Francesca Rucci ◽  
Laura Patrizi ◽  
Mike Recher ◽  
Stephan Regenass ◽  
...  

The contribution of B cells to the pathology of Omenn syndrome and leaky severe combined immunodeficiency (SCID) has not been previously investigated. We have studied a mut/mut mouse model of leaky SCID with a homozygous Rag1 S723C mutation that impairs, but does not abrogate, V(D)J recombination activity. In spite of a severe block at the pro–B cell stage and profound B cell lymphopenia, significant serum levels of immunoglobulin (Ig) G, IgM, IgA, and IgE and a high proportion of Ig-secreting cells were detected in mut/mut mice. Antibody responses to trinitrophenyl (TNP)-Ficoll and production of high-affinity antibodies to TNP–keyhole limpet hemocyanin were severely impaired, even after adoptive transfer of wild-type CD4+ T cells. Mut/mut mice produced high amounts of low-affinity self-reactive antibodies and showed significant lymphocytic infiltrates in peripheral tissues. Autoantibody production was associated with impaired receptor editing and increased serum B cell–activating factor (BAFF) concentrations. Autoantibodies and elevated BAFF levels were also identified in patients with Omenn syndrome and leaky SCID as a result of hypomorphic RAG mutations. These data indicate that the stochastic generation of an autoreactive B cell repertoire, which is associated with defects in central and peripheral checkpoints of B cell tolerance, is an important, previously unrecognized, aspect of immunodeficiencies associated with hypomorphic RAG mutations.


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