scholarly journals Stromal Notch Ligands Drive Notch2-Dependent Transdifferentiation of Follicular B Cells into Marginal Zone-like B Cells in Lymphopenic Environments

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 38-39
Author(s):  
Daniela Gómez Atria ◽  
Brian T. Gaudette ◽  
Eric Perkey ◽  
Jennifer Londregan ◽  
Samantha Kelly ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Notch Signaling ◽  
Marginal Zone ◽  
Cell Phenotype ◽  
White Pulp ◽  
Marginal Sinus ◽  
Cell Pool ◽  
Cell Conversion ◽  
Notch Ligands

In lymphopenic environments, secondary lymphoid organs regulate the size of B and T cell compartments by supporting homeostatic proliferation of mature lymphocytes. Although this process operates in multiple clinically relevant settings, including after bone marrow transplantation and chemotherapy as well as in aging individuals, little is known about its underlying molecular mechanisms and functional consequences. In mice, mature naïve B cells include mostly follicular B (FoB) cells in spleen and lymph nodes, as well as specialized marginal zone B (MZB) cells in the spleen with innate-like functions and a capacity for rapid plasma cell differentiation. To identify mechanisms controlling the size and composition of the peripheral B cell pool, we developed a mouse model in which highly purified CTV-labelled B6-CD45.1 FoB cells were adoptively transferred intravenously to lymphopenic B6-CD45.2 Rag2-/- mice, lacking mature B and T cells, or control B6-CD45.2 lymphoid-replete recipients. Within two days after transfer of CD19+ CD93neg CD21int CD23high B6-CD45.1 FoB cells (106, >99% purity), CD45.1+ donor-derived B cells had upregulated expression of surface IgM (sIgM) and CD21 in the spleen of Rag2-/- recipients, but not in wild type control recipients. At day 4 and day 8, the majority of transferred B cells remained sIgMhi and CD21hi in Rag2-/- recipients and gradually showed decreased CD23 and sIgD as well as increased CD1d expression, consistent with loss of their FoB phenotype and acquisition of a characteristic MZB cell phenotype (sIgMhisIgDlow CD21hi CD1dhi CD23low). These phenotypic changes were followed by a burst of proliferation (CTV dilution) between day 4 and day 8 after transfer. Immunofluorescence microscopy of host Rag2-/- spleen sections at day 2 post-transfer identified clusters of transferred B cells localized around CD169+ macrophages at the white pulp/red pulp interface close to the marginal sinus, with subsequent proliferation in this area. We next investigated if Notch signaling regulates this transdifferentiation process, by analogy to its role in normal MZB cell homeostasis. Treatment of Rag2-/- recipients with blocking antibodies against Delta-like-1 Notch ligands (anti-DLL1) or Notch2 receptors (anti-NRR2) completely inhibited lymphopenia-induced FoB to MZB cell conversion and proliferation. To identify the cellular source of DLL1 Notch ligands, we studied transferred B cells in Rag2-/-;Ccl19-Cre+;Dll1f/f recipients, lacking Dll1 expression in all Ccl19-Cre+ fibroblastic reticular cells and their progeny. In these mice as compared to Rag2-/- recipients, FoB to MZB transdifferentiation was almost completely abrogated and transferred cells no longer clustered with marginal sinus-associated macrophages. Thus, stromal DLL1 Notch ligands are critical to regulate the size and composition of the splenic peripheral B cell pool in lymphopenic mice through DLL1/Notch2 interactions. Furthermore, FoB cells are not locked in their FoB cell fate, as commonly assumed, but are instead endowed with plastic transdifferentiation potential in response to DLL1/Notch2-mediated signals that function as a sensor of B cell lymphopenia. We speculate that these adaptive physiological functions of the Notch signaling pathway play an important role in the homeostasis of mature B cells within their stromal microenvironment, and that they can be hijacked during malignant transfomation in Notch-dependent mature B cell lymphomas such as CLL and marginal zone lymphoma. Disclosures Siebel: Genentech: Current Employment. Maillard:Allogene: Consultancy; Regeneron: Consultancy; Genentech: Consultancy.

scholarly journals Marginal zone B cells emerge as a critical component of pregnancy well-being

Reproduction ◽  
2016 ◽  
Vol 151 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Damián O Muzzio ◽  
Katharina B Ziegler ◽  
Jens Ehrhardt ◽  
Marek Zygmunt ◽  
Federico Jensen
Keyword(s):  
B Cells ◽  
B Cell ◽  
Marginal Zone ◽  
Well Being ◽  
Eutherian Mammal ◽  
Cell Phenotype ◽  
Protective Mechanisms ◽  
Marginal Zone B Cells ◽  
Immunological Mechanisms ◽  
Protective Antibodies

The success of eutherian mammal evolution was certainly supported by the ability of the already existing immune system to adapt to the presence of the semi-allogeneic fetus without losing the capability to defend the mother against infections. This required the acquisition of highly regulated and coordinated immunological mechanisms. Failures in the development of these strategies not only lead to the interruption of pregnancy but also compromise maternal health. Alongside changes on the cytokine profile – expansion of tolerogenic dendritic and regulatory T cells – a profound adaptation of the B cell compartment during pregnancy was recently described. Among others, the suppression of B cell lymphopoiesis and B cell lymphopenia were proposed to be protective mechanisms tending to reduce the occurrence of autoreactive B cells that might recognize fetal structures and put pregnancy on risk. On the other hand, expansion of the pre-activated marginal zone (MZ) B cell phenotype was described as a compensatory strategy launched to overcome B cell lymphopenia thus ensuring a proper defense. In this work, using an animal model of pregnancy disturbances, we demonstrated that the suppression of B cell lymphopoiesis as well as splenic B cell lymphopenia occur independently of pregnancy outcome. However, only animals undergoing normal pregnancies, but not those suffering from pregnancy disturbances, could induce an expansion and activation of the MZ B cells. Hence, our results clearly show that MZ B cells, probably due to the production of natural protective antibodies, participate in the fine balance of immune activation required for pregnancy well-being.

Constitutive alternative NF-κB signaling promotes marginal zone B-cell development but disrupts the marginal sinus and induces HEV-like structures in the spleen

Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2381-2389 ◽  
Author(s):  
Feng Guo ◽  
Debra Weih ◽  
Elke Meier ◽  
Falk Weih
Keyword(s):  
Cell Adhesion ◽  
B Cells ◽  
B Cell ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Marginal Zone ◽  
Cell Development ◽  
B Cell Development ◽  
Marginal Sinus ◽  
Cell Adhesion Molecule 1

Nuclear factor-κB (NF-κB) plays a crucial role in B-cell and lymphoid organ development. Here, we studied the consequences of constitutive, signal-independent activation of the alternative NF-κB pathway for the splenic marginal zone (MZ). In contrast to nfkb2−/− mice, which lack both p100 and p52, mice that lack only the inhibitory p100 precursor but still express the p52 subunit of NF-κB2 (p100−/−) had markedly elevated MZ B-cell numbers. Both cell-intrinsic mechanisms and increased stromal expression of vascular cell adhesion molecule-1 (VCAM-1) contributed to the accumulation of MZ B cells in p100−/− spleens. While migration of p100−/− MZ B cells toward the lysophospholipid sphingosine-1 phosphate (S1P) was not affected, CXCL13-stimulated chemotaxis was impaired, correlating with reduced migration of MZ B cells into follicles in response to lipopolysaccharide (LPS). Strikingly, p100 deficiency resulted in the absence of a normal marginal sinus, strongly induced expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) and glycosylated cell adhesion molecule-1 (GlyCAM-1), and the formation of nonfunctional ectopic high endothelial venule (HEV)–like structures in the red pulp. Thus, constitutive activation of the alternative NF-κB pathway favors MZ B-cell development and accumulation but leads to a disorganized spleen microarchitecture.

scholarly journals The CXCR7 chemokine receptor promotes B-cell retention in the splenic marginal zone and serves as a sink for CXCL12

Blood ◽  
2012 ◽  
Vol 119 (2) ◽  
pp. 465-468 ◽  
Author(s):  
Hongsheng Wang ◽  
Natalie Beaty ◽  
Sophia Chen ◽  
Chen-Feng Qi ◽  
Marek Masiuk ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Marginal Zone ◽  
Scavenger Receptor ◽  
Cell Formation ◽  
Serum Levels ◽  
Antigenic Specificity ◽  
White Pulp ◽  
Surface Receptors ◽  
And Function

The splenic marginal zone (MZ) is comprised of specialized populations of B cells, dendritic cells, and macrophages that are uniquely arrayed outside the white pulp follicles to screen the blood for bacterial and other particulate Ags. Mechanisms responsible for MZ B-cell formation, localization, retention, and function are understood to include antigenic specificity, transcription factors, integrins, and surface receptors for soluble ligands such as S1P. Here, we add to this repertoire by demonstrating that the receptor for CXCL12, CXCR7, is expressed on MZ but not on follicular B cells. Treatment of mice with CXCR7 inhibitors led to disruption of MZ architecture, reduced numbers of MZ B cells, and altered granulocyte homeostasis associated with increasing serum levels of CXCL12. CXCR7 thus appears to function as a scavenger receptor for CXCL12 on MZ B cells.

Constitutive Activation of the Canonical NF-κB Signaling Pathway and Expanded Populations of Splenic Marginal Zone B Cells Characterize Em-BCL10 Transgenic Mice.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1341-1341
Author(s):  
Zhaoyang Li ◽  
Liquan Xue ◽  
Dong-Mi Shin ◽  
Chen-Feng Qi ◽  
Quangeng Zhang ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Signaling Pathway ◽  
Cell Population ◽  
Cell Biology ◽  
Marginal Zone ◽  
Constitutive Expression ◽  
White Pulp ◽  
Marginal Zone B Cells ◽  
Constitutive Activation

Abstract The BCL10 gene was isolated from the breakpoint region of the t(1;14)(p22;q32) chromosomal translocation, a recurrent chromosomal abnormality in mucosa-associated lymphoid tissue (MALT)-type lymphomas. The translocation results in constitutive over-expression and nuclear location of the BCL10 protein. To understand the physiological and pathogenic roles played by BCL10 in B-cell biology, a transgenic (TG) mouse model was developed with a human BCL10 gene driven by Em. The TG was expressed in thymic but not peripheral T cells and in the spleen; lymph nodes were negative. Although the lymphoid compartments of the TG mice were grossly normal, histologic studies showed the splenic marginal zone (MZ) to be significantly expanded and, in older mice, to compress the white pulp. In addition, about 10% of animals developed B-cell neoplasms by 18 months of age. By FACS analyses, the number of MZ B cells was increased nearly 2-fold, and both MZ and follicular (FOL) B cells exhibited a marked down-regulation of CD23 expression. In the peritoneum of TG mice, the B1a B-cell population was markedly reduced while the B1b subset was increased over 2-fold. Studies of purified MZ and FOL B cells from normal and TG mice showed that MZ B cells from TG mice had a survival advantage in culture. Studies of the canonical NF-κB signaling pathway that lies downstream from BCL10 showed that it was constitutively activated with high levels of nuclear p50 and p65 protein identified by Western blotting. Quantitative real-time RT-PCR analyses of purified splenic B cells from normal and TG mice for expression of 384 genes identified 44 with significant differences in expression. Almost half of these genes were known NF-κB targets and included genes known to influence B-cell survival (BAFF, IL-10) or associated with MZ lymphomas (S100A9). These results indicate that constitutive expression of BCL10 in B cells is not sufficient to induce transformation alone and that as-yet-unknown secondary mutations are required. Nonetheless, expression of BCL10 clearly resulted in constitutive activation of the canonical NF-κB signaling pathway and a prominent expansion of the MZ B-cell population, thereby setting the stage for later development of lymphomas.

Ligation of tumour-produced mucins to CD22 dramatically impairs splenic marginal zone B-cells

2009 ◽  
Vol 417 (3) ◽  
pp. 673-683 ◽  
Author(s):  
Munetoyo Toda ◽  
Risa Hisano ◽  
Hajime Yurugi ◽  
Kaoru Akita ◽  
Kouji Maruyama ◽  
...  
Keyword(s):  
Sialic Acid ◽  
B Cells ◽  
B Cell ◽  
Marginal Zone ◽  
Cell Signalling ◽  
Negative Regulator ◽  
Mammary Adenocarcinoma ◽  
Marginal Zone B Cells ◽  
Tumour Bearing

CD22 [Siglec-2 (sialic acid-binding, immunoglobulin-like lectin-2)], a negative regulator of B-cell signalling, binds to α2,6- sialic acid-linked glycoconjugates, including a sialyl-Tn antigen that is one of the typical tumour-associated carbohydrate antigens expressed on various mucins. Many epithelial tumours secrete mucins into tissues and/or the bloodstream. Mouse mammary adenocarcinoma cells, TA3-Ha, produce a mucin named epiglycanin, but a subline of them, TA3-St, does not. Epiglycanin binds to CD22 and inhibits B-cell signalling in vitro. The in vivo effect of mucins in the tumour-bearing state was investigated using these cell lines. It should be noted that splenic MZ (marginal zone) B-cells were dramatically reduced in the mice bearing TA3-Ha cells but not in those bearing TA3-St cells, this being consistent with the finding that the thymus-independent response was reduced in these mice. When the mucins were administered to normal mice, a portion of them was detected in the splenic MZ associated with the MZ B-cells. Furthermore, administration of mucins to normal mice clearly reduced the splenic MZ B-cells, similar to tumour-bearing mice. These results indicate that mucins in the bloodstream interacted with CD22, which led to impairment of the splenic MZ B-cells in the tumour-bearing state.

scholarly journals Notch2-mediated plasticity between marginal zone and follicular B cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Markus Lechner ◽  
Thomas Engleitner ◽  
Tea Babushku ◽  
Marc Schmidt-Supprian ◽  
Roland Rad ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Marginal Zone ◽  
Close Contact ◽  
Immunological Function ◽  
Transitional B Cells ◽  
Bona Fide ◽  
Fate Decision ◽  
Follicular B Cells ◽  
Cell Follicle

AbstractFollicular B (FoB) and marginal zone B (MZB) cells are functionally and spatially distinct mature B cell populations in the spleen, originating from a Notch2-dependent fate decision after splenic influx of immature transitional B cells. In the B cell follicle, a Notch2-signal is provided by DLL-1-expressing fibroblasts. However, it is unclear whether FoB cells, which are in close contact with these DLL-1 expressing fibroblasts, can also differentiate to MZB cells if they receive a Notch2-signal. Here, we show induced Notch2IC-expression in FoB cells re-programs mature FoB cells into bona fide MZB cells as is evident from the surface phenotype, localization, immunological function and transcriptome of these cells. Furthermore, the lineage conversion from FoB to MZB cells occurs in immunocompetent wildtype mice. These findings demonstrate plasticity between mature FoB and MZB cells that can be driven by a singular signaling event, the activation of Notch2.

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

Blood ◽  
2008 ◽  
Vol 112 (10) ◽  
pp. 4139-4147 ◽  
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.

scholarly journals Morphologic and Functional Effects of Gamma Secretase Inhibition on Splenic Marginal Zone B Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Maria Cristina de Vera Mudry ◽  
Franziska Regenass-Lechner ◽  
Laurence Ozmen ◽  
Bernd Altmann ◽  
Matthias Festag ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
B Cell ◽  
Marginal Zone ◽  
Nuclear Translocation ◽  
Recovery Period ◽  
Functional Characterization ◽  
Notch Receptor ◽  
Marginal Zone B Cells ◽  
Cell Fate Decisions

Theγ-secretase complex is a promising target in Alzheimer’s disease because of its role in the amyloidogenic processing ofβ-amyloid precursor protein. This enzyme also catalyzes the cleavage of Notch receptor, resulting in the nuclear translocation of intracellular Notch where it modulates gene transcription. Notch signaling is essential in cell fate decisions during embryogenesis, neuronal differentiation, hematopoiesis, and development of T and B cells, including splenic marginal zone (MZ) B cells. This B cell compartment participates in the early phases of the immune response to blood-borne bacteria and viruses. Chronic treatment with the oralγ-secretase inhibitor RO4929097 resulted in dose-dependent decreased cellularity (atrophy) of the MZ of rats and mice. Significant decreases in relative MZ B-cell numbers of RO4929097-treated animals were confirmed by flow cytometry. Numbers of MZ B cells reverted to normal after a sufficient RO4929097-free recovery period. Functional characterization of the immune response in relation to RO4929097-related MZ B cell decrease was assessed in mice vaccinated with inactivated vesicular stomatitis virus (VSV). Compared with the immunosuppressant cyclosporin A, RO4929097 caused only mild and reversible delayed early neutralizing IgM and IgG responses to VSV. Thus, the functional consequence of MZ B cell decrease on host defense is comparatively mild.

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