Mechanisms of B Cell Tolerance after in Utero Hematopoietic Cell Transplantation

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4289-4289
Author(s):  
Lauren Elizabeth McClain ◽  
Grace Lee ◽  
Aimee G Kim ◽  
Patricia Tsao ◽  
Eline Luning Prak ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Hematopoietic Cell Transplantation ◽  
Donor Cell ◽  
Absolute Number ◽  
Receptor Editing ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
The Absolute ◽  
Functional Inactivation

Abstract Background: In utero hematopoietic cell transplantation (IUHCT) is a nonmyeloablative, nonimmunosuppressive transplant approach that results in donor cell engraftment across immune barriers. Although a significant amount of work has investigated the fate of T cells following IUHCT, little attention has been paid to B cell tolerance and the fate of donor derived host reactive or host derived donor reactive B cells following IUHCT. B cell tolerance is broadly believed to occur by a combination of 3 mechanisms: deletion, receptor editing, and functional inactivation (anergy). In the current study we attempt to elucidate the mechanism(s) by which B cell tolerance occurs following IUHCT. Methods: 10x106 donor bone marrow (BM) cells were injected intravenously via the vitelline vein into gestational day 14 murine fetuses. IUHCT was performed in the congenic (C57Bl/6-GFP [H2Kb ] into C57Bl/6 [H2Kb ]) and allogeneic (C57Bl/6-GFP into Balb/c [H2Kd ]) strain combinations. Naive Balb/c and C57Bl/6 mice served as controls. Mice were sacrificed at day of life 3 (P3), 1 month and 4 months of age at which time their BM, spleen, and serum were harvested. To assess B cell deletion, flow cytometry was used to determine the absolute # and % of host and donor immature and pre B cells in the BM. Additionally, apoptosis of host and donor BM derived B cells was determined by annexin staining. Central receptor editing was evaluated using RT qPCR to measure the amount of Vκ-RS rearrangments in BM pre-B cells. Peripheral receptor editing was studied by calculating the % of λ light chains in mature splenocytes identified by flow cytometry. Finally, functional inactivation of donor reactive host B cells was assessed by measuring anti-H2Kb serum antibodies (ab) of allogeneic chimeras, naive, and immunized mice at 1 month of age. Results: The absolute number of BM immature B cells was decreased in allogeneic recipients of IUHCT compared to noninjected Balb/c controls at 1 month of age (fig 1). This effect was lost by 4 months of age. The decrease in B cells resulted primarily from a decrease in immature donor as opposed to host B cells compared to controls (% immature donor B cells in allogeneic recipients vs. controls: 16.2% vs. 39.9%; p<0.0005). Donor B cells in allogeneic chimeras also demonstrated a trend toward increased apoptosis compared to controls (24.8 vs. 18.7%; p=0.2) which was not seen in immature host B cells (18.3 vs. 18.6%; p=0.9). There was no significant decrease in the absolute number of immature B cells or increased apoptosis in congenic recipients compared to uninjected controls. These findings suggest deletion of autoreactivedonor B cells. Light chain receptor editing involves rearrangements within the κ and λ gene loci and may occur in BM pre-B cells or mature B cells in the spleen. We found no difference in the Vκ-RS rearrangements of pre B cells in allogeneic chimeras and controls at 1 month. In contrast, the quantity of total λ+ mature splenic B cells was increased in allogeneic chimeras at P3 (10.8 vs. 8.4%; p=0.02) and resulted from an increased host λ+ % compared to controls (10.8 vs. 8.4% p=0.03) suggesting peripheral receptor editing of host cells (fig.2). The λ+ % increase in allogeneic chimeras was lost by 1 month. Autoreactive B cells that escape deletion and receptor editing can be functionally inactivated. Neither allogeneic nor naive mice developed ab to H2Kb splenocytes, however, Balb/c mice immunized to H2kb antigen showed high ablevels (MFI fold change: allo-0.89 naive-1.37 imm-2.77; p<0.05). Conclusion: B cell tolerance after IUHCT is achieved by distinct mechanisms for host and donor cell populations. Donor derived host reactive B cells undergo deletion and apoptosis while receptor editing and functional inactivation are the primary mechanisms of B cell tolerance of host derived donor reactive B cells. We hope use this and future studies of antigen specific B cell tolerance to harness the immunologic potential of IUHCT for many hematopoietic and immunologic congenital diseases. Disclosures No relevant conflicts of interest to declare.

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 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 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 Efficient Peripheral Clonal Elimination of B Lymphocytes in MRL/lpr Mice Bearing Autoantibody Transgenes

1998 ◽  
Vol 188 (5) ◽  
pp. 909-917 ◽  
Author(s):  
Jennifer A. Kench ◽  
David M. Russell ◽  
David Nemazee
Keyword(s):  
B Cells ◽  
B Cell ◽  
Genetic Background ◽  
Cell Tolerance ◽  
Cell Repertoire ◽  
B Cell Tolerance ◽  
B Cell Repertoire ◽  
Nuclear Antigens ◽  
Large Numbers ◽  
Liver And Kidney

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.

Role Of B Cell Tolerance In PF4/Heparin Antibody Production

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2396-2396
Author(s):  
Yongwei Zheng ◽  
Alexander W Wang ◽  
Mei Yu ◽  
Anand Padmanabhan ◽  
Benjamin E Tourdot ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Cell Tolerance ◽  
Inflammatory Stimulus ◽  
Wild Type ◽  
B Cell Tolerance ◽  
Advisory Committees

Abstract Heparin-induced thrombocytopenia (HIT) is an immune-mediated disorder that can cause fatal arterial or venous thrombosis/thromboembolism. Immune complexes consisting of heparin, platelet factor 4 (PF4) and PF4/heparin-reactive antibodies are central to the pathogenesis of HIT. However, heparin, a glycosoaminoglycan, and PF4 are normal body constituents and it is as yet unclear what triggers the initial induction of pathogenic antibodies. Here we described detection of B cells among peripheral blood mononuclear cells (PBMCs) from each of 9 healthy adults that produced PF4/heparin-specific IgM antibodies following in vitro stimulation with ubiquitous pro-inflammatory molecules containing unmethylated CpG dinucleotides derived from bacterial and viral DNA. PF4/heparin-specific IgM-generating B cells were present at a frequency of at least 0.03 to 1 per thousand B cells present in the PBMC population. Similarly, splenic B cells isolated from unmanipulated wild-type mice consistently produced PF4/heparin-reactive antibodies following in vitro stimulation with CpG. In addition, wild-type mice produced PF4/heparin-reactive antibodies upon in vivo challenge with CpG whereas unchallenged wild-type mice did not. These findings demonstrate that both humans and mice possess pre-existing, inactive and tolerant PF4/heparin-specific B cells. We suggest that tolerance can be broken by a strong inflammatory stimulus, leading to activation of these B cells and production of antibodies that recognize PF4/heparin in vitro and in vivo. Consistent with this concept, mice lacking protein kinase Cd (PKCd), a signaling molecule of the B-cell survival factor BAFF (B-cell activation factor), that are known to have breakdown of B-cell tolerance to self-antigens, spontaneously produced anti-PF4/heparin antibodies in the absence of an inflammatory stimulus. Taken together, these findings demonstrate that breakdown of tolerance can lead to PF4/heparin-specific antibody production and that B-cell tolerance plays an important role in HIT pathogenesis. Disclosures: White II: Bayer: Membership on an entity’s Board of Directors or advisory committees; CSL-Behring: Membership on an entity’s Board of Directors or advisory committees; NIH: Membership on an entity’s Board of Directors or advisory committees; Asklepios: Membership on an entity’s Board of Directors or advisory committees; Wyeth: Membership on an entity’s Board of Directors or advisory committees; Entegrion: Membership on an entity’s Board of Directors or advisory committees; Biogen: Membership on an entity’s Board of Directors or advisory committees; Baxter: Membership on an entity’s Board of Directors or advisory committees.

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.

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