Maternal B Cell-Intrinsic MyD88 Signaling Mediates LPS-Driven Intrauterine Fetal Death

Immunological networks balance tolerance towards paternal alloantigens during pregnancy with normal immune response to pathogens. Subclinical infections can impact this balance and lead to preterm birth or even intrauterine fetal death (IUFD). We recently showed that loss of maternal B cells renders murine fetuses susceptible to IUFD after LPS exposure. Since the signaling pathway involved in this B-cell mediated response remains unclear, we aimed to understand the participation of MyD88 in this response using B-cell-specific MyD88-deficient (BMyD88-/-) mice. B cells isolated from wild-type (WT), BMyD88-/-, CD19-/- and MyD88-/- dams on gestational day (gd) 10 responded differently to LPS concerning cytokine secretion. In vivo LPS challenge on gd 10 provoked IUFD in CD19-/- mothers with functional MyD88, while fetuses from BMyD88-/- and MyD88-/- mice were protected. These outcomes were associated with altered cytokine levels in the maternal serum and changes in CD4+ T-cell responses. Overall, the loss of MyD88 signaling in maternal B cells prevents the activation of cytokine release that leads to IUFD. Thus, while MyD88 signaling in maternal B cells protects the mother from infection, it ultimately kills the fetus. Understanding the cellular mechanisms underlying infection-driven pregnancy complications is the first step to designing powerful therapeutic strategies in the future.

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Serial analysis of the effects of methimazole therapy on circulating B cell subsets in Graves' disease

Journal of Endocrinology ◽

10.1677/joe.0.1510231 ◽

1996 ◽

Vol 151 (2) ◽

pp. 231-240 ◽

Cited By ~ 8

Author(s):

J J Corrales ◽

A Orfao ◽

A López ◽

J Ciudad ◽

M T Mories

Keyword(s):

B Cells ◽

B Cell ◽

Antithyroid Drug ◽

Graves Disease ◽

Cellular Mechanisms ◽

Stable Pattern ◽

Antithyroid Drug Therapy ◽

B Cell Subsets

Abstract The immunosuppressive effects of antithyroid drug therapy are well recognized; however, the cellular mechanisms underlying their action remain largely unknown. In the present paper we have prospectively analyzed the in vivo effects of methimazole treatment on a large number of circulating B cell subsets, involved in the effector phase of the immune response, in a group of 18 hyperthyroid patients with Graves' disease (GD). The patients were sequentially studied before (day 0) and 7, 14, 30, 90 and 180 days after methimazole therapy. The results were compared with both a group of 19 age- and sex-matched healthy controls and a group of 20 untreated/euthyroid GD patients in long-term remission. The combination of flow cytometry and three colour immunofluorescence revealed a clear increase (P<0·001) in the numbers of circulating total B cells (CD19+) due to a significant increase (P<0·001) in the CD5+, FMC7+, CD5+/FMC7+ and CD23+ B cell subsets in hyperthyroid GD patients with respect to both healthy individuals and to GD patients in long-term remission. The absolute numbers of all these B cell subsets analyzed before treatment, although abnormal, were not statistically different from those observed during the whole period of therapy. When comparing the percentages of these B cell subsets during treatment, significant changes (P<0·001) were only observed in the proportion of CD5+, CD5+/FMC7+ and CD5 −B cells at the end of the follow-up period with respect to those found both before and during the first month of therapy. Whereas CD5+ and CD5+/FMC7+ B cells decreased (P<0·001) after 3 months of therapy, CD5 − B cells showed a significant increase (P<0·001) at the end of therapy. It is remarkable that the percentage of CD5+, CD5+/FMC7+, CD5 − and CD23+ B cell subsets were abnormal during the whole period of treatment and that they never reached normal values. These results show that, in vivo, GD patients treated with methimazole exhibited an abnormal but rather stable pattern of B cell distribution, similar to that present in hyperthyroid untreated GD patients, except for the CD5+ and CD5 − B cell populations. Our findings suggest that in vivo methimazole therapy would not directly have an important influence on circulating B cell subsets. Journal of Endocrinology (1996) 151, 231–240

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Transformation-associated alterations in interactions between pre-B cells and fibronectin

Blood ◽

10.1182/blood.v76.11.2311.2311 ◽

1990 ◽

Vol 76 (11) ◽

pp. 2311-2320 ◽

Cited By ~ 22

Author(s):

FM Lemoine ◽

S Dedhar ◽

GM Lima ◽

CJ Eaves

Keyword(s):

B Cells ◽

B Cell ◽

Cell Line ◽

Cell Lines ◽

Stromal Cells ◽

Stromal Cell ◽

Cell Attachment ◽

Attachment Site ◽

Receptor Antibodies

Abstract Marrow stromal elements produce as yet uncharacterized soluble growth factors that can stimulate the proliferation of murine pre-B cells, although close contact between these two cell types appears to ensure a better pre-B cell response. We have now shown that freshly isolated normal pre-B cells (ie, the B220+, surface mu- fraction of adult mouse bone marrow) adhere to fibronectin (FN) via an RGD cell-attachment site, as shown in a serum-free adherence assay, and they lose this functional ability on differentiation in vivo into B cells (ie, the B220+, surface mu+ fraction). Similarly, cells from an immortalized but stromal cell-dependent and nontumorigenic murine pre-B cell line originally derived from a Whitlock-Witte culture were also found to adhere to fibronectin (FN) via an RGD cell-attachment site. Moreover, in the presence of anti-FN receptor antibodies, the ability of this immortalized pre-B cell line to proliferate when co-cultured with a supportive stromal cell line (M2–10B4 cells) was markedly reduced (down to 30% of control). This suggests that pre-B cell attachment to FN on stromal cells may be an important component of the mechanism by which stromal cells stimulate normal pre-B cell proliferation and one that is no longer operative to control their more differentiated progeny. Two differently transformed pre-B cell lines, both of which are autocrine, stromal-independent, tumorigenic in vivo, and partially or completely differentiation-arrested at a very early stage of pre-B cell development, did not bind to FN. In addition, anti-FN receptor antibodies were much less effective in diminishing the ability of these tumorigenic pre-B cells to respond to M2–10B4 cell stimulation, which could still be demonstrated when the tumorigenic pre-B cells were co- cultured with M2–10B4 cells at a sufficiently low cell density. Analysis of cell surface molecules immunoprecipitated from both the nontumorigenic and tumorigenic pre-B cell lines by an anti-FN receptor antibody showed an increase in very late antigen (VLA) alpha chain(s) in both tumorigenic pre-B cell lines and a decrease in the beta 1 chain in one. Interestingly, all of the pre-B cell lines expressed similar amounts of messenger RNA for the beta 1 chain of the FN receptor. These results suggest that alteration of FN receptor expression on pre-B cells may represent a mechanism contributing to the outgrowth of leukemic pre-B cells with an autocrine phenotype and capable of stromal cell-independent, autonomous growth.

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Hyper‐metabolic B cells in the spleens of old mice make antibodies with autoimmune specificities

Immunity & Ageing ◽

10.1186/s12979-021-00222-3 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Daniela Frasca ◽

Maria Romero ◽

Denisse Garcia ◽

Alain Diaz ◽

Bonnie B. Blomberg

Keyword(s):

B Cells ◽

B Cell ◽

Inflammatory Markers ◽

Cell Subset ◽

Antibody Responses ◽

Metabolic Phenotype ◽

Cellular Mechanisms ◽

Autoimmune Antibodies ◽

B Cell Subsets ◽

Old Mice

Abstract Background Aging is associated with increased intrinsic B cell inflammation, decreased protective antibody responses and increased autoimmune antibody responses. The effects of aging on the metabolic phenotype of B cells and on the metabolic programs that lead to the secretion of protective versus autoimmune antibodies are not known. Methods Splenic B cells and the major splenic B cell subsets, Follicular (FO) and Age-associated B cells (ABCs), were isolated from the spleens of young and old mice and left unstimulated. The RNA was collected to measure the expression of markers associated with intrinsic inflammation and autoimmune antibody production by qPCR. B cells and B cell subsets were also stimulated with CpG and supernatants collected after 7 days to measure autoimmune IgG secretion by ELISA. Metabolic measures (oxygen consumption rate, extracellular acidification rate and glucose uptake) were performed using a Seahorse XFp extracellular flux analyzer. Results Results have identified the subset of ABCs, whose frequencies and numbers increase with age and represent the most pro-inflammatory B cell subset, as the cell type mainly if not exclusively responsible for the expression of inflammatory markers and for the secretion of autoimmune antibodies in the spleen of old mice. Hyper-inflammatory ABCs from old mice are also hyper-metabolic, as compared to those from young mice and to the subset of FO B cells, a feature needed not only to support their higher expression of RNA for inflammatory markers but also their higher autoimmune antibody secretion. Conclusions These results identify a relationship between intrinsic inflammation, metabolism and autoimmune B cells and suggest possible ways to understand cellular mechanisms that lead to the generation of pathogenic B cells, that are hyper-inflammatory and hyper-metabolic, and secrete IgG antibodies with autoimmune specificities.

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WASP confers selective advantage for specific hematopoietic cell populations and serves a unique role in marginal zone B-cell homeostasis and function

Blood ◽

10.1182/blood-2008-02-140715 ◽

2008 ◽

Vol 112 (10) ◽

pp. 4139-4147 ◽

Cited By ~ 71

Author(s):

Lisa S. Westerberg ◽

Miguel A. de la Fuente ◽

Fredrik Wermeling ◽

Hans D. Ochs ◽

Mikael C. I. Karlsson ◽

...

Keyword(s):

T Cells ◽

B Cells ◽

B Cell ◽

Marginal Zone ◽

Hematopoietic Cells ◽

Selective Advantage ◽

Relative Contribution ◽

B Cell Homeostasis ◽

And Function

Abstract Development of hematopoietic cells depends on a dynamic actin cytoskeleton. Here we demonstrate that expression of the cytoskeletal regulator WASP, mutated in the Wiskott-Aldrich syndrome, provides selective advantage for the development of naturally occurring regulatory T cells, natural killer T cells, CD4+ and CD8+ T lymphocytes, marginal zone (MZ) B cells, MZ macrophages, and platelets. To define the relative contribution of MZ B cells and MZ macrophages for MZ development, we generated wild-type and WASP-deficient bone marrow chimeric mice, with full restoration of the MZ. However, even in the presence of MZ macrophages, only 10% of MZ B cells were of WASP-deficient origin. We show that WASP-deficient MZ B cells hyperproliferate in vivo and fail to respond to sphingosine-1-phosphate, a crucial chemoattractant for MZ B-cell positioning. Abnormalities of the MZ compartment in WASP−/− mice lead to aberrant uptake of Staphylococcus aureus and to a reduced immune response to TNP-Ficoll. Moreover, WASP-deficient mice have increased levels of “natural” IgM antibodies. Our findings reveal that WASP regulates both development and function of hematopoietic cells. We demonstrate that WASP deficiency leads to an aberrant MZ that may affect responses to blood-borne pathogens and peripheral B-cell tolerance.

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Long-term proliferating early pre-B-cell lines and clones with the potential to develop to surface immunoglobulin-positive, mitogen-reactive B-cells in vitro and in vivo

Biochemical Society Transactions ◽

10.1042/bst0190275 ◽

1991 ◽

Vol 19 (2) ◽

pp. 275-276 ◽

Cited By ~ 4

Author(s):

Antonius Rolink ◽

Akira Kudo ◽

Fritz Melchers

Keyword(s):

B Cells ◽

B Cell ◽

Cell Lines ◽

Surface Immunoglobulin

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The fate of fetal and adult B-cell progenitors grafted into immunodeficient CBA/N mice.

Journal of Experimental Medicine ◽

10.1084/jem.150.3.548 ◽

1979 ◽

Vol 150 (3) ◽

pp. 548-563 ◽

Cited By ~ 70

Author(s):

C J Paige ◽

P W Kincade ◽

M A Moore ◽

G Lee

Keyword(s):

B Cells ◽

B Cell ◽

Fetal Liver ◽

Cell Cloning ◽

Generate Functional ◽

Self Renewal ◽

Relative Ability ◽

Cloning Assay ◽

Regenerative Ability

The relative ability of various precursors to generate functional B cells in vivo was assessed by transferring normal, chromosomally-marked CBA/H-T6T6 cells to irradiated or unirradiated immunodeficient CBA/N mice. Emergence of donor-derived B cells was monitored by means of a B-cell cloning assay (in which CBA/N cells are inactive), and by karyotpic analysis of lymphoid, myeloid, and stem cell metaphases. Grafts of lymph node, spleen, anti-mu surface immunoglobin suppressed bone marrow, sIg+ cell-depleted marrow, normal marrow, fetal liver, and yolk sac suggest: (a) there is little self-renewal of sIg+ B cells in these models; (b) pre-committed cells have extensive proliferative/differentiative potential and at least initially contribute most of the newly-formed B cells; (c) populations or pre-B cells obtained from various sources differ in their regenerative ability; (d) CBA/N mice are deficient in a category of pre-B cells which are found in fetal liver; and (e) selective B-cell chimerism results from grafting of unirradiated CBA/N mice.

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IMMU-29. B-CELL-BASED VACCINE PRODUCES GLIOBLASTOMA-REACTIVE ANTIBODIES THAT CONTRIBUTE TO TUMOR CLEARANCE

Neuro-Oncology ◽

10.1093/neuonc/noab196.388 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi98-vi98

Author(s):

Brandyn Castro ◽

Mark Dapash ◽

David Hou ◽

Aida Rashidi ◽

Deepak Kanojia ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Humoral Immunity ◽

Ex Vivo ◽

Murine Models ◽

Effector Functions ◽

Tumor Bearing ◽

Tumor Clearance ◽

Cellular And Humoral Immunity

Abstract Glioblastomas (GBM) are characterized by a strong immunosuppressive environment, contributing to their poor prognosis and limited therapeutic response to immunotherapies. B-cells represent a unique opportunity to promote immunotherapy due to their potential to kill tumors by both cellular and humoral immunity. To generate our B-cell-based vaccine (BVax) platform, we activated 41BBL+ B cells from tumor bearing mice or GBM patient blood with BAFF, CD40, and IFNg. We have previously demonstrated that BVax potentiates radiation therapy, temozolomide and checkpoint blockade in murine models of GBM via enhancement of CD8+ T-cell based immunity. The aim of this current study is to evaluate the humoral effector functions of BVax. We examined the antibody (Ab) repertoire in vivo from serum of tumor-bearing B-cell knockout mice treated with BVax or by ex vivo stimulation of patient-derived BVax. Upon systemic administration, BVax infiltrates the tumor where it differentiates into plasmablasts. Murine BVax- and BNaive-derived serum immunoglobulin generated in vivo showed that the majority of murine BVax-derived Ab were IgG isotype, while BNaive mainly produced IgM isotype. Transfer of IgG from BVax treated mice directly into tumors of recipient animals significantly prolonged their survival, demonstrating anti-tumor cytotoxicity directly through humoral immunity. Patient-derived BVax activated ex vivo showed a plasmablast phenotype and the Ab repertoire supports the previous findings seen in our murine model. Our work suggests BVax-derived IgGs role in antibody-dependent cellular cytotoxicity and improved survival in murine models. This function, in addition to its role in cellular immunity against GBM, renders BVax a potentially effective alternative immunotherapeutic option for GBM patients.

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

Developmental Immunology ◽

10.1080/1044667031000088057 ◽

2002 ◽

Vol 9 (2) ◽

pp. 86-95 ◽

Cited By ~ 8

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.

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Ligand-independent Signaling Functions for the B Lymphocyte Antigen Receptor and Their Role in Positive Selection during B Lymphopoiesis

Journal of Experimental Medicine ◽

10.1084/jem.194.11.1583 ◽

2001 ◽

Vol 194 (11) ◽

pp. 1583-1596 ◽

Cited By ~ 112

Author(s):

Gregory Bannish ◽

Ezequiel M. Fuentes-Pananá ◽

John C. Cambier ◽

Warren S. Pear ◽

John G. Monroe

Keyword(s):

B Cells ◽

B Cell ◽

B Lymphocyte ◽

Antigen Receptor ◽

Cell Development ◽

B Cell Development ◽

B Lymphopoiesis ◽

Biologically Relevant ◽

Developmental Progression

Signal transduction through the B cell antigen receptor (BCR) is determined by a balance of positive and negative regulators. This balance is shifted by aggregation that results from binding to extracellular ligand. Aggregation of the BCR is necessary for eliciting negative selection or activation by BCR-expressing B cells. However, ligand-independent signaling through intermediate and mature forms of the BCR has been postulated to regulate B cell development and peripheral homeostasis. To address the importance of ligand-independent BCR signaling functions and their regulation during B cell development, we have designed a model that allows us to isolate the basal signaling functions of immunoglobulin (Ig)α/Igβ-containing BCR complexes from those that are dependent upon ligand-mediated aggregation. In vivo, we find that basal signaling is sufficient to facilitate pro-B → pre-B cell transition and to generate immature/mature peripheral B cells. The ability to generate basal signals and to drive developmental progression were both dependent on plasma membrane association of Igα/Igβ complexes and intact immunoregulatory tyrosine activation motifs (ITAM), thereby establishing a correlation between these processes. We believe that these studies are the first to directly demonstrate biologically relevant basal signaling through the BCR where the ability to interact with both conventional as well as nonconventional extracellular ligands is eliminated.

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