scholarly journals BH3-only protein Noxa regulates apoptosis in activated B cells and controls high-affinity antibody formation

Blood ◽  
2012 ◽  
Vol 119 (6) ◽  
pp. 1440-1449 ◽  
Author(s):  
Felix M. Wensveen ◽  
Ingrid A. M. Derks ◽  
Klaas P. J. M. van Gisbergen ◽  
Alex M. de Bruin ◽  
Joost C. M. Meijers ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Influenza Infection ◽  
Affinity Maturation ◽  
Antibody Responses ◽  
Booster Immunization ◽  
High Affinity ◽  
Activated B Cells

Abstract The efficiency of humoral immune responses depends on the selective outgrowth of B cells and plasmacells that produce high affinity antibodies. The factors responsible for affinity maturation of B cell clones in the germinal center (GC) have been well established but selection mechanisms that allow clones to enter the GC are largely unknown. Here we identify apoptosis, regulated by the proapoptotic BH3-only member Noxa (Pmaip1), as a critical factor for the selection of high-affinity clones during B cell expansion after antigen triggering. Noxa is induced in activated B cells, and its ablation provides a survival advantage both in vitro and in vivo. After immunization or influenza infection, Noxa−/− mice display enlarged GCs, in which B cells with reduced antigen affinity accumulate. As a consequence, Noxa−/− mice mount low affinity antibody responses compared with wild-type animals. Importantly, the low affinity responses correlate with increased immunoglobulin diversity, and cannot be corrected by booster immunization. Thus, normal elimination of low affinity cells favors outgrowth of the remaining high-affinity clones, and this is mandatory for the generation of proper antibody responses. Manipulation of this process may alter the breadth of antibody responses after immunization.

CD40 Ligand Activation Alters B Cell Migration to Secondary Lymphoid Organs.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 935-935
Author(s):  
Yvonne A. Efebera ◽  
Tahamtan Ahmadi ◽  
Amanda Flies ◽  
David H. Sherr
Keyword(s):  
B Cells ◽  
Lymph Nodes ◽  
B Cell ◽  
Cd40 Ligand ◽  
Lymphoid Organs ◽  
Cell Populations ◽  
Secondary Lymphoid Organs ◽  
Activated B Cells

Abstract Background: An increased understanding of the requirements for antigen presentation has encouraged development of cell-based cancer vaccines. Trials using dendritic cells (DC) as antigen presenting cells (APC) for immunotherapy of several malignancies have shown considerable success. However, the difficulty in generating large numbers of DC required for these immunizations has led to the search for alternative APC. One such candidate is the CD40 ligand (CD40L)-activated B cell, populations of which can readily be expanded in vitro. To be an effective vehicle for antigen presentation to T cells, CD40L-activated B cells must be capable of migrating to secondary lymphoid organs. Therefore, CD40L-activated B cell migration following subcutaneous or intravenous injection was evaluated. Methods: Splenic B cells from GFP transgenic mice were activated with CD40L + IL-4 and expanded in vitro prior to i.v. or s.c. injection of 3–4 x 107 into C57BL/6 mice. Recipient mice were sacrificed 2 hrs or 1–14 days thereafter and the percentage of GFP+/B220+ B cells quantified in spleens and lymph nodes by flow cytometry. Localization of these cells within lymphoid organs was determined by immunohistochemistry. In some experiments, activated C57BL/6 B cells were labeled with carboxy fluorescein succinimidyl ester (CFSE) to evaluate cell growth in vivo. Results: Murine B cell populations were readily expanded by culture on CD40L-transfected L cells in the presence of IL-4. CD40L-activated B cells expressed high levels of CD80, CD86, and LFA-1 but decreased levels of L-selectin relative to naive cells. Following i.v. injection, activated B cells were detected in spleens and lymph nodes within 1 day. Peak concentrations of activated B cells were noted in spleens and lymph nodes on days 7 (4.8% of injected cells) and 10 (1.25% of injected cells) respectively, suggesting expansion of the activated B cell population in vivo. Naive B cells injected i.v. were detected within 1 day but their number declined precipitously thereafter. Following s.c. injection, peak levels of CD40L-activated B cells were noted on day 5 (spleens) and day 7 (lymph nodes). As determined by immunohistochemistry, both CD40L-activated and naïve B cells injected i.v. appeared in B cell regions of spleens and lymph nodes. While the kinetics of accumulation of CD40L-activated B cells injected s.c. or i.v. were similar, s.c. injected CD40L-activated B cells homed to the T cell regions of spleens and lymph nodes. CFSE experiments indicated that these activated B cells continue to grow in vivo. In contrast, naïve B cells injected s.c. only appeared in B cell regions. Conclusion: CD40L-activated B cell populations can readily be expanded in vitro, CD40L-activated B cells migrate to secondary lymphoid organs even when injected s.c., activated B cell populations expand in vivo, and s.c. injected, CD40L-activated B cells preferentially home to T cell regions of secondary lymphoid organs. These results suggest that this effective APC may serve as an important vehicle for delivery and presentation of exogenous (e.g. tumor) antigens to T cells in vivo.

scholarly journals Plasmablasts derive from CD23-negative activated B cells after the extinction of IL-4/STAT6 signaling and IRF4 induction

Blood ◽  
2020 ◽  
Author(s):  
Amandine Pignarre ◽  
Fabrice Chatonnet ◽  
Gersende Caron ◽  
Marion Haas ◽  
Fabienne Desmots-Loyer ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Initial Response ◽  
Degradation Process ◽  
B Cell Differentiation ◽  
Similar Phenotype ◽  
Fate Decision ◽  
Activated B Cells

The terminal differentiation of B cells into antibody-secreting cells (ASCs) is a critical component of adaptive immune responses. However, it is a very sensitive process, which dysfunctions lead to a great variety of lymphoproliferative neoplasia including germinal center-derived lymphomas. To better characterize the late genomic events driving the ASC differentiation of human primary naive B cells, we used our in vitro differentiation system and a combination of RNA sequencing with ATAC-seq. Our results evidenced two mechanisms driving human terminal B cell differentiation. Firstly, after an initial response to IL-4, cells that committed to an ASC fate downregulated the CD23 marker and IL-4 signaling, whereas cells that maintained IL-4 signaling did not differentiate. Secondly, human CD23-negative cells also increased IRF4 protein to levels required for ASC differentiation, but independently of the ubiquitin-mediated degradation process previously described in the mouse. Finally, we showed that CD23-negative cells (i) carried the imprint of their previous activated B-cell status, (ii) were precursors of plasmablasts, and (iii) had a similar phenotype to in vivo pre-plasmablasts. Altogether, our results provide an unprecedented genomic characterization of the fate decision between activated B cells and plasmablast, which gives new insights in pathological mechanisms driving lymphoma biology.

scholarly journals CD4+T Cells Promote Antibody Production but Not Sustained Affinity Maturation during Borrelia burgdorferi Infection

2014 ◽  
Vol 83 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Rebecca A. Elsner ◽  
Christine J. Hastey ◽  
Nicole Baumgarth
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Plasma Cells ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Antibody Responses ◽  
Content Type ◽  
High Affinity

CD4 T cells are crucial for enhancing B cell-mediated immunity, supporting the induction of high-affinity, class-switched antibody responses, long-lived plasma cells, and memory B cells. Previous studies showed that the immune response toBorrelia burgdorferiappears to lack robust T-dependent B cell responses, as neither long-lived plasma cells nor memory B cells form for months after infection, and nonswitched IgM antibodies are produced continuously during this chronic disease. These data prompted us to evaluate the induction and functionality ofB. burgdorferiinfection-induced CD4 TFHcells. We report that CD4 T cells were effectively primed and TFHcells induced afterB. burgdorferiinfection. These CD4 T cells contributed to the control ofB. burgdorferiburden and supported the induction ofB. burgdorferi-specific IgG responses. However, while affinity maturation of antibodies against a prototypic T-dependentB. burgdorferiprotein, Arthritis-related protein (Arp), were initiated, these increases were reversed later, coinciding with the previously observed involution of germinal centers. The cessation of affinity maturation was not due to the appearance of inhibitory or exhausted CD4 T cells or a strong induction of regulatory T cells.In vitroT-B cocultures demonstrated that T cells isolated fromB. burgdorferi-infected but notB. burgdorferi-immunized mice supported the rapid differentiation of B cells into antibody-secreting plasma cells rather than continued proliferation, mirroring the induction of rapid short-lived instead of long-lived T-dependent antibody responsesin vivo. The data further suggest thatB. burgdorferiinfection drives the humoral response away from protective, high-affinity, and long-lived antibody responses and toward the rapid induction of strongly induced, short-lived antibodies of limited efficacy.

scholarly journals Primary Immune Responses and Affinity Maturation Are Controlled by IgD

2021 ◽  
Vol 12 ◽  
Author(s):  
Timm Amendt ◽  
Omar El Ayoubi ◽  
Alexandra T. Linder ◽  
Gabriele Allies ◽  
Marc Young ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Antibody Production ◽  
Autoimmune Diabetes ◽  
Affinity Maturation ◽  
Antibody Responses ◽  
Cell Functions ◽  
High Affinity ◽  
Deficient Mice

Mature B cells co-express IgM and IgD B cell antigen receptors (BCR) on their surface. While IgM BCR expression is already essential at early stages of development, the role of the IgD-class BCR remains unclear as most B cell functions appeared unchanged in IgD-deficient mice. Here, we show that IgD-deficient mice have an accelerated rate of B cell responsiveness as they activate antibody production within 24h after immunization, whereas wildtype (WT) animals required 3 days to activate primary antibody responses. Strikingly, soluble monovalent antigen suppresses IgG antibody production induced by multivalent antigen in WT mice. In contrast, IgD-deficient mice were not able to modulate IgG responses suggesting that IgD controls the activation rate of B cells and subsequent antibody production by sensing and distinguishing antigen-valences. Using an insulin-derived peptide we tested the role of IgD in autoimmunity. We show that primary autoreactive antibody responses are generated in WT and in IgD-deficient mice. However, insulin-specific autoantibodies were detected earlier and caused more severe symptoms of autoimmune diabetes in IgD-deficient mice as compared to WT mice. The rapid control of autoimmune diabetes in WT animals was associated with the generation of high-affinity IgM that protects insulin from autoimmune degradation. In IgD-deficient mice, however, the generation of high-affinity protective IgM is delayed resulting in prolonged autoimmune diabetes. Our data suggest that IgD is required for the transition from primary, highly autoreactive, to secondary antigen-specific antibody responses generated by affinity maturation.

scholarly journals IL-21 is the primary common γ chain-binding cytokine required for human B-cell differentiation in vivo

Blood ◽  
2011 ◽  
Vol 118 (26) ◽  
pp. 6824-6835 ◽  
Author(s):  
Mike Recher ◽  
Lucinda J. Berglund ◽  
Danielle T. Avery ◽  
Morton J. Cowan ◽  
Andrew R. Gennery ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
B Cells ◽  
B Cell ◽  
Humoral Immunity ◽  
Antibody Responses ◽  
Cytokine Signaling ◽  
Cell Engraftment ◽  
Cell Immunity

Abstract SCID resulting from mutations in IL2RG or JAK3 is characterized by lack of T and natural killer cells; B cells are present in normal number, but antibody responses are defective. Hematopoietic cell transplantation (HCT) is curative for SCID. However, B-cell dysfunction persists in a substantial proportion of patients. We hypothesized that impaired B-cell responses after HCT in IL2RG/JAK3 deficiency results from poor donor B-cell engraftment and defective γc-dependent cytokine signaling in host B cells. To test this, and to identify which γc cytokine(s) is critical for humoral immunity, we studied 28 transplanted patients with IL2RG/JAK3 deficiency. Lack of donor B-cell engraftment associated with persistent humoral dysfunction and significantly reduced memory B cells. B-cell proliferation induced by CD40L alone or together with CpG, anti-Ig, IL-4, IL-10, or IL-13 was comparable in healthy controls and in post-HCT SCID patients, irrespective of their chimerism status. However, in vitro stimulation with CD40L/IL-21 induced B-cell proliferation, plasmablast differentiation, and antibody secretion in patients with donor B cells, but not in patients with autologous B cells. These data imply that IL-21–mediated signaling is critical for long-lived humoral immunity and to restore antibody responses in IL2RG/JAK3-deficient patients after HCT. Furthermore, in vitro stimulation with CD40L/IL-21 can predict in vivo B-cell immunity in IL2RG/JAK3 SCID after transplantation.

scholarly journals High affinity germinal center B cells are actively selected into the plasma cell compartment

2006 ◽  
Vol 203 (11) ◽  
pp. 2419-2424 ◽  
Author(s):  
Tri Giang Phan ◽  
Didrik Paus ◽  
Tyani D. Chan ◽  
Marian L. Turner ◽  
Stephen L. Nutt ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
Plasma Cell ◽  
Plasma Cells ◽  
Affinity Maturation ◽  
The Body ◽  
Plasma Cell Differentiation ◽  
High Affinity

A hallmark of T cell–dependent immune responses is the progressive increase in the ability of serum antibodies to bind antigen and provide immune protection. Affinity maturation of the antibody response is thought to be connected with the preferential survival of germinal centre (GC) B cells that have acquired increased affinity for antigen via somatic hypermutation of their immunoglobulin genes. However, the mechanisms that drive affinity maturation remain obscure because of the difficulty in tracking the affinity-based selection of GC B cells and their differentiation into plasma cells. We describe a powerful new model that allows these processes to be followed as they occur in vivo. In contrast to evidence from in vitro systems, responding GC B cells do not undergo plasma cell differentiation stochastically. Rather, only GC B cells that have acquired high affinity for the immunizing antigen form plasma cells. Affinity maturation is therefore driven by a tightly controlled mechanism that ensures only antibodies with the greatest possibility of neutralizing foreign antigen are produced. Because the body can sustain only limited numbers of plasma cells, this “quality control” over plasma cell differentiation is likely critical for establishing effective humoral immunity.

scholarly journals Differential Regulation of Mouse B Cell Development by Transforming Growth Factor β1

2002 ◽  
Vol 9 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Denise A. Kaminski ◽  
John J. Letterio ◽  
Peter D. Burrows
Keyword(s):  
B Cells ◽  
Growth Factor ◽  
B Cell ◽  
Transforming Growth Factor ◽  
Plasma Cells ◽  
Population Analysis ◽  
Cell Development ◽  
B Cell Development

Transforming growth factor β (TGFβ) can inhibit thein vitroproliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1-/-mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1-pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1+pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell developmentin vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.

scholarly journals Germinal center reutilization by newly activated B cells

2009 ◽  
Vol 206 (13) ◽  
pp. 2907-2914 ◽  
Author(s):  
Tanja A. Schwickert ◽  
Boris Alabyev ◽  
Tim Manser ◽  
Michel C. Nussenzweig
Keyword(s):  
B Cells ◽  
Immune Responses ◽  
Somatic Hypermutation ◽  
Affinity Maturation ◽  
Anatomical Structures ◽  
Class Switch ◽  
Cell Clones ◽  
T Cell Help ◽  
Activated B Cells

Germinal centers (GCs) are specialized structures in which B lymphocytes undergo clonal expansion, class switch recombination, somatic hypermutation, and affinity maturation. Although these structures were previously thought to contain a limited number of isolated B cell clones, recent in vivo imaging studies revealed that they are in fact dynamic and appear to be open to their environment. We demonstrate that B cells can colonize heterologous GCs. Invasion of primary GCs after subsequent immunization is most efficient when T cell help is shared by the two immune responses; however, it also occurs when the immune responses are entirely unrelated. We conclude that GCs are dynamic anatomical structures that can be reutilized by newly activated B cells during immune responses.

scholarly journals The autoantigen-binding B cell repertoires of normal and of chronically graft-versus-host-diseased mice.

1987 ◽  
Vol 165 (6) ◽  
pp. 1675-1687 ◽  
Author(s):  
A G Rolink ◽  
T Radaszkiewicz ◽  
F Melchers
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
The Other ◽  
Cell Populations ◽  
Foreign Antigen ◽  
Alloreactive T Cells ◽  
Polyclonal Activator ◽  
Activated B Cells

A quantitative analysis of the frequencies of autoantibody-producing B cells in GVHD and in normal mice has been undertaken by generating collections of hybridomas of activated B cells. These hybridomas secreted sufficient quantities of Ig to allow binding analyses on a panel of autoantigens. B cells have been activated in a variety of ways. In vivo they were activated by injection of alloreactive T cells of one parent, leading to GVHD by a foreign antigen, sheep erythrocytes, in a secondary response, or by the polyclonal activator LPS. B cells from an experimentally unstimulated animal were used for an analysis of the normal background. In vitro B cells were activated by alloreactive T cells or by LPS. The frequencies of hybridomas and, therefore, of activated B cells producing autoantibodies to DNA or to kidney were not significantly different in mice activated by a graft-vs.-host T cell response as compared with B cell populations activated by any of the other procedures. They were found to compose 7.1-17.1% of the total repertoire of activated B cells. Moreover, the frequencies of autoantibody-producing activated B cells does not change with time after induction of the graft-vs.-host reaction. The pattern and frequencies of autoantigen-binding specificities to cytoskeleton, smooth muscle, nuclei, mitochondria, and DNA were not found to be different in any of the groups of hybridomas. The single notable exception, found in GVHD mice, were hybridomas producing autoantibodies to kidney proximal tubular brush border. These results allow the conclusion that autoantigen-binding B cells exist in an activated state in GVHD mice, as well as in mice activated by a foreign antigen or by a polyclonal activator, in B cell populations activated in vitro either by alloreactive T cells or by a polyclonal activator, and even in the background of experimentally unstimulated animals. T cell-mediated graft-vs.-host activation, in large part, does not lead to a selective expansion of autoantigen-binding B cells. The main difference between the graft-vs.-host-activated B cell repertoire and all others is that approximately 90% of teh autoantibodies were of the IgG class, whereas al autoantibodies found in the other groups were IgM.

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