scholarly journals Receptor editing and genetic variability in human autoreactive B cells

2015 ◽  
Vol 213 (1) ◽  
pp. 93-108 ◽  
Author(s):  
Julie Lang ◽  
Takayuki Ota ◽  
Margot Kelly ◽  
Pamela Strauch ◽  
Brian M. Freed ◽  
...  
Keyword(s):  
B Cells ◽  
Human Populations ◽  
Receptor Editing ◽  
Human Immune System ◽  
B Cell Tolerance ◽  
Clonal Deletion ◽  
Humanized Mouse Model ◽  
Central Tolerance ◽  
Autoreactive B Cells ◽  
Human B Cells

The mechanisms by which B cells undergo tolerance, such as receptor editing, clonal deletion, and anergy, have been established in mice. However, corroborating these mechanisms in humans remains challenging. To study how autoreactive human B cells undergo tolerance, we developed a novel humanized mouse model. Mice expressing an anti–human Igκ membrane protein to serve as a ubiquitous neo self-antigen (Ag) were transplanted with a human immune system. By following the fate of self-reactive human κ+ B cells relative to nonautoreactive λ+ cells, we show that tolerance of human B cells occurs at the first site of self-Ag encounter, the bone marrow, via a combination of receptor editing and clonal deletion. Moreover, the amount of available self-Ag and the genetics of the cord blood donor dictate the levels of central tolerance and autoreactive B cells in the periphery. Thus, this model can be useful for studying specific mechanisms of human B cell tolerance and to reveal differences in the extent of this process among human populations.

scholarly journals Light chain editing in kappa-deficient animals: a potential mechanism of B cell tolerance.

1994 ◽  
Vol 180 (5) ◽  
pp. 1805-1815 ◽  
Author(s):  
E L Prak ◽  
M Trounstine ◽  
D Huszar ◽  
M Weigert
Keyword(s):  
B Cells ◽  
B Cell ◽  
Heavy Chain ◽  
Light Chain ◽  
Allelic Exclusion ◽  
Receptor Editing ◽  
B Cell Tolerance ◽  
Clonal Deletion ◽  
Autoreactive B Cells ◽  
Surface Receptors

The genetic organization of the kappa and lambda light chain loci permits multiple, successive rearrangement attempts at each allele. Multiple rearrangements allow autoreactive B cells to escape clonal deletion by editing their surface receptors. Editing may also facilitate efficient B cell production by salvaging cells with nonproductive light chain (L chain) rearrangements. To study receptor editing of kappa L chains, we have characterized B cells from mice hemizygous for the targeted inactivation of kappa (JCkD/wt) which have an anti-DNA heavy chain transgene, 3H9. Hybridomas from JCkD/wt mice exhibited an increased frequency of rearrangements to downstream Jk segments (such as Jk5) compared with most surveys from normal mice, consistent with receptor editing by sequential kappa locus rearrangements in JCkD/wt. We observed an even higher frequency of rearrangements to Jk5 in 3H9 JCkD/wt animals compared with nontransgenic JCkD/wt, consistent with editing of autoreactive kappa in 3H9 JCkD/wt. We also recovered a large number of 3H9 JCkD/wt lines with Vk12/13-Jk5 rearrangements and could demonstrate by PCR and Southern analysis that up to three quarters of these lines underwent multiple kappa rearrangements. To investigate editing at the lambda locus, we used homozygous kappa-deficient animals (JCkD/JCkD and 3H9 JCkD/JCkD). The frequencies of V lambda 1 and V lambda 2 rearrangements among splenic hybridomas in 3H9 JCkD/JCkD were reduced by 75% whereas V lambda X was increased 5-10-fold, compared with nontransgenic JCkD/JCkD animals. This indicates that V lambda 1 and V lambda 2 are negatively regulated in 3H9 JCkD/JCkD, consistent with earlier studies that showed that the 3H9 heavy chain, in combination with lambda 1 binds DNA. As successive lambda rearrangements to V lambda X do not inactivate V lambda 1, the consequence of lambda editing in 3H9 JCkD/JCkD would be failed allelic exclusion at lambda. However, analysis of 18 3H9 JCkD/JCkD hybridomas with V lambda 1 and V lambda X DNA rearrangements revealed that most of these lines do not have productive lambda 1 rearrangements. In sum, both kappa and lambda loci undergo editing to recover from nonproductive rearrangement, but only kappa locus editing appears to play a substantial role in rescuing autoreactive B cells from deletion.

scholarly journals Central human B cell tolerance manifests with a distinctive cell phenotype and is enforced via CXCR4 signaling in hu-mice

2021 ◽  
Vol 118 (16) ◽  
pp. e2021570118
Author(s):  
Thiago Alves da Costa ◽  
Jacob N. Peterson ◽  
Julie Lang ◽  
Jeremy Shulman ◽  
Xiayuan Liang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Immune System ◽  
B Cells ◽  
B Cell ◽  
Cell Tolerance ◽  
Human Immune System ◽  
B Cell Tolerance ◽  
Autoreactive B Cells ◽  
Cell Clones ◽  
Human Immune

Central B cell tolerance, the process restricting the development of many newly generated autoreactive B cells, has been intensely investigated in mouse cells while studies in humans have been hampered by the inability to phenotypically distinguish autoreactive and nonautoreactive immature B cell clones and the difficulty in accessing fresh human bone marrow samples. Using a human immune system mouse model in which all human Igκ+ B cells undergo central tolerance, we discovered that human autoreactive immature B cells exhibit a distinctive phenotype that includes lower activation of ERK and differential expression of CD69, CD81, CXCR4, and other glycoproteins. Human B cells exhibiting these characteristics were observed in fresh human bone marrow tissue biopsy specimens, although differences in marker expression were smaller than in the humanized mouse model. Furthermore, the expression of these markers was slightly altered in autoreactive B cells of humanized mice engrafted with some human immune systems genetically predisposed to autoimmunity. Finally, by treating mice and human immune system mice with a pharmacologic antagonist, we show that signaling by CXCR4 is necessary to prevent both human and mouse autoreactive B cell clones from egressing the bone marrow, indicating that CXCR4 functionally contributes to central B cell tolerance.

scholarly journals Active PI3K abrogates central tolerance in high-avidity autoreactive B cells

2019 ◽  
Vol 216 (5) ◽  
pp. 1135-1153 ◽  
Author(s):  
Sarah A. Greaves ◽  
Jacob N. Peterson ◽  
Pamela Strauch ◽  
Raul M. Torres ◽  
Roberta Pelanda
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Peripheral Tolerance ◽  
High Avidity ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Central Tolerance ◽  
Autoreactive B Cells ◽  
Self Antigen

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.

scholarly journals Enforced Bcl-2 Expression Inhibits Antigen-mediated Clonal Elimination of Peripheral B Cells in an Antigen Dose–dependent Manner and Promotes Receptor Editing in Autoreactive, Immature B Cells

1997 ◽  
Vol 186 (9) ◽  
pp. 1513-1522 ◽  
Author(s):  
Julie Lang ◽  
B. Arnold ◽  
G. Hammerling ◽  
Alan W. Harris ◽  
Stanley Korsmeyer ◽  
...  
Keyword(s):  
B Cells ◽  
Tolerance Induction ◽  
Antigen Expression ◽  
Dependent Manner ◽  
Receptor Editing ◽  
B Cell Tolerance ◽  
Antigen Dose ◽  
Central Tolerance ◽  
Self Tolerance ◽  
Immature B Cells

The mechanisms that establish immune tolerance in immature and mature B cells appear to be distinct. Membrane-bound autoantigen is thought to induce developmental arrest and receptor editing in immature B cells, whereas mature B cells have shortened lifespans when exposed to the same stimulus. In this study, we used Eμ–bcl-2-22 transgenic (Tg) mice to test the prediction that enforced expression of the Bcl-2 apoptotic inhibitor in B cells would rescue mature, but not immature, B cells from tolerance induction. To monitor tolerance to the natural membrane autoantigen H-2Kb, we bred 3–83μδ (anti-Kk,b) Ig Tg mice to H-2b mice or to mice expressing transgene-driven Kb in the periphery. In 3–83μδ/bcl-2 Tg mice, deletion of autoreactive B cells induced by peripheral Kb antigen expression in the liver (MT-Kb Tg) or epithelia (KerIV-Kb Tg), was partly or completely inhibited, respectively. Furthermore, Bcl-2 protected peritoneal B-2 B cells from deletion mediated by acute antigen exposure, but this protection could be overcome by higher antigen dose. In contrast to its ability to block peripheral self-tolerance, Bcl-2 overexpression failed to inhibit central tolerance induced by bone marrow antigen expression, but instead, enhanced the receptor editing process. These studies indicate that apoptosis plays distinct roles in central and peripheral B cell tolerance.

scholarly journals Liver-expressed Igκ superantigen induces tolerance of polyclonal B cells by clonal deletion not κ to λ receptor editing

2011 ◽  
Vol 208 (3) ◽  
pp. 617-629 ◽  
Author(s):  
Takayuki Ota ◽  
Miyo Ota ◽  
Bao Hoa Duong ◽  
Amanda L. Gavin ◽  
David Nemazee
Keyword(s):  
B Cells ◽  
Lymph Nodes ◽  
B Cell ◽  
Tolerance Induction ◽  
Cell Receptor ◽  
Mature Stage ◽  
Receptor Editing ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Clonal Deletion

Little is know about the nature of peripheral B cell tolerance or how it may vary in distinct lineages. Although autoantibody transgenic studies indicate that anergy and apoptosis are involved, some studies claim that receptor editing occurs. To model peripheral B cell tolerance in a normal, polyclonal immune system, we generated transgenic mice expressing an Igκ–light chain–reactive superantigen targeted to the plasma membrane of hepatocytes (pAlb mice). In contrast to mice expressing κ superantigen ubiquitously, in which κ cells edit efficiently to λ, in pAlb mice, κ B cells underwent clonal deletion. Their κ cells failed to populate lymph nodes, and the remaining splenic κ cells were anergic, arrested at a semi-mature stage without undergoing receptor editing. In the liver, κ cells recognized superantigen, down-regulated surface Ig, and expressed active caspase 3, suggesting ongoing apoptosis at the site of B cell receptor ligand expression. Some, apparently mature, κ B1 and follicular B cells persisted in the peritoneum. BAFF (B cell–activating factor belonging to the tumor necrosis factor family) overexpression rescued splenic κ B cell maturation and allowed κ cells to populate lymph nodes. Our model facilitates analysis of tissue-specific autoimmunity, tolerance, and apoptosis in a polyclonal B cell population. The results suggest that deletion, not editing, is the major irreversible pathway of tolerance induction among peripheral B cells.

scholarly journals Receptor editing: How B cells stay tolerant

2007 ◽  
Vol 204 (8) ◽  
pp. 1735-1735
Author(s):  
Hema Bashyam
Keyword(s):  
B Cells ◽  
B Cell ◽  
Main Mechanism ◽  
Receptor Editing ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Autoreactive B Cells

In 1993, David Nemazee and Martin Weigert independently showed that autoreactive B cells could proofread, alter, and reexpress modified receptors to become nonautoreactive. This process, called “receptor editing,” has since gained prominence as the main mechanism of B cell tolerance.

scholarly journals Surrogate Light Chain Expressing Human Peripheral B Cells Produce Self-reactive Antibodies

2003 ◽  
Vol 199 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Eric Meffre ◽  
Anne Schaefer ◽  
Hedda Wardemann ◽  
Patrick Wilson ◽  
Eric Davis ◽  
...  
Keyword(s):  
B Cells ◽  
Light Chain ◽  
Antinuclear Antibodies ◽  
Receptor Editing ◽  
Tolerance Mechanisms ◽  
Central Tolerance ◽  
Surrogate Light Chain ◽  
Human B Cells ◽  
Autoreactive Antibodies ◽  
Light Chain Antibody

Human B cells that coexpress surrogate and conventional light chains (V-preB+L+) show an unusual heavy and light chain antibody repertoire that display evidence of receptor editing. However, it is unclear whether V-preB+L+ B cells have been silenced by receptor editing or still express autoreactive antibodies. Here we report that 68% of the antibodies expressed by V-preB+L+ B cells are autoreactive. A majority of these autoantibodies are true antinuclear antibodies (ANA), and 50% of the ANAs are also reactive with a diverse group of antigens that include dsDNA, ssDNA, immunoglobulin, insulin, and bacterial lipopolysaccharide. Such antibodies are rarely encountered among conventional B cells. We conclude that V-preB+L+ B cells are a unique subset of normal circulating human B cells that escape central tolerance mechanisms and express self-reactive antibodies including potentially harmful ANAs.

scholarly journals Reduced receptor editing in lupus-prone MRL/lpr mice

2007 ◽  
Vol 204 (12) ◽  
pp. 2853-2864 ◽  
Author(s):  
Jennifer L. Lamoureux ◽  
Lisa C. Watson ◽  
Marie Cherrier ◽  
Patrick Skog ◽  
David Nemazee ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Messenger Rna ◽  
Immunoglobulin M ◽  
Considerable Proportion ◽  
Receptor Editing ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Immature B Cells

The initial B cell repertoire contains a considerable proportion of autoreactive specificities. The first major B cell tolerance checkpoint is at the stage of the immature B cell, where receptor editing is the primary mode of eliminating self-reactivity. The cells that emigrate from the bone marrow have a second tolerance checkpoint in the transitional compartment in the spleen. Although it is known that the second checkpoint is defective in lupus, it is not clear whether there is any breakdown in central B cell tolerance in the bone marrow. We demonstrate that receptor editing is less efficient in the lupus-prone strain MRL/lpr. In an in vitro system, when receptor-editing signals are given to bone marrow immature B cells by antiidiotype antibody or after in vivo exposure to membrane-bound self-antigen, MRL/lpr 3-83 transgenic immature B cells undergo less endogenous rearrangement and up-regulate recombination activating gene messenger RNA to a lesser extent than B10 transgenic cells. CD19, along with immunoglobulin M, is down-regulated in the bone marrow upon receptor editing, but the extent of down-regulation is fivefold less in MRL/lpr mice. Less efficient receptor editing could allow some autoreactive cells to escape from the bone marrow in lupus-prone mice, thus predisposing to autoimmunity.

scholarly journals Impaired early B cell tolerance in patients with rheumatoid arthritis

2005 ◽  
Vol 201 (10) ◽  
pp. 1659-1667 ◽  
Author(s):  
Jonathan Samuels ◽  
Yen-Shing Ng ◽  
Claire Coupillaud ◽  
Daniel Paget ◽  
Eric Meffre
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
Autoantibody Production ◽  
Autoreactive B Cells ◽  
Healthy Donors ◽  
Polyreactive Antibodies

Autoantibody production is a characteristic of most autoimmune diseases including rheumatoid arthritis (RA). The role of these autoantibodies in the pathogenesis of RA remains elusive, but they appear in the serum many years before the onset of clinical disease suggesting an early break in B cell tolerance. The stage of B cell development at which B cell tolerance is broken in RA remains unknown. We previously established in healthy donors that most polyreactive developing B cells are silenced in the bone marrow, and additional autoreactive B cells are removed in the periphery. B cell tolerance in untreated active RA patients was analyzed by testing the specificity of recombinant antibodies cloned from single B cells. We find that autoreactive B cells fail to be removed in all six RA patients and represent 35–52% of the mature naive B cell compartment compared with 20% in healthy donors. In some patients, RA B cells express an increased proportion of polyreactive antibodies that can recognize immunoglobulins and cyclic citrullinated peptides, suggesting early defects in central B cell tolerance. Thus, RA patients exhibit defective B cell tolerance checkpoints that may favor the development of autoimmunity.

scholarly journals Light chain editors of anti-DNA receptors in human B cells

2014 ◽  
Vol 211 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Olga Kalinina ◽  
Yue Wang ◽  
Kevin Sia ◽  
Marko Radic ◽  
Pierre-André Cazenave ◽  
...  
Keyword(s):  
B Cells ◽  
Dna Binding ◽  
Mouse Models ◽  
Protein Sequences ◽  
Receptor Editing ◽  
Transgenic Mouse Models ◽  
Human B Cells ◽  
Self Tolerance ◽  
V Genes ◽  
Complementarity Determining Region

Receptor editing is a mechanism of self-tolerance used in newly generated B cells. The expressed heavy (H) or light (L) chain of an autoreactive receptor is replaced by upstream V genes which eliminate or modify autoreactivity. Editing of anti-DNA receptors has been characterized in anti-DNA transgenic mouse models including 3H9, 3H9/56R, and their revertant 3H9GL. Certain L chains, termed editors, rescue anti-DNA B cells by neutralizing or modifying DNA binding of the H chain. This editing mechanism acts on the natural H chain repertoire; endogenous H chains with anti-DNA features are expressed primarily in combination with editor L chains. We ask whether a similar set of L chains exists in the human repertoire, and if so, do they edit H chains with anti-DNA signatures? We compared the protein sequences of mouse editors to all human L chains and found several human L chains similar to mouse editors. These L chains diminish or veto anti-DNA binding when expressed with anti-DNA H chains. The human H chains expressed with these L chains also have relatively high arginine (Arg) content in the H chain complementarity determining region (H3), suggesting that receptor editing plays a role in establishing tolerance to DNA in humans.

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