scholarly journals E2A and IRF-4/Pip Promote Chromatin Modification and Transcription of the Immunoglobulin κ Locus in Pre-B Cells

2006 ◽  
Vol 26 (3) ◽  
pp. 810-821 ◽  
Author(s):  
Adam S. Lazorchak ◽  
Mark S. Schlissel ◽  
Yuan Zhuang
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germ Line ◽  
Gene Dosage ◽  
Gene Activation ◽  
Chromatin Modification ◽  
Cell Stage ◽  
Immunoglobulin Kappa ◽  
Intronic Enhancer ◽  
Specific Manner

ABSTRACT The immunoglobulin kappa light chain (Igκ) locus is regulated in a lineage- and stage-specific manner during B-cell development. The highly restricted timing of V to J gene recombination at the pre-B-cell stage is under the control of two enhancers, the intronic enhancer (κEi) and the 3′ enhancer (κE3′), flanking the constant exon. E2A transcription factors have been indicated to be directly involved in the regulation of Igκ locus activation. In this study, we utilize E2A-deficient pre-B cells to directly investigate the mechanism of E2A-mediated Igκ activation. We demonstrate that Igκ germ line transcription is severely impaired and recombination is blocked in the absence of E2A. Reconstitution of E2A −/− pre-B cells with inducible human E2A (E47R) is sufficient to promote chromatin modification of Igκ and rescue Igκ germ line transcription and Jκ gene recombinase accessibility. Furthermore, we show that increased E2A recruitment to κEi and κE3′ correlates with activation of Igκ in pre-B cells and that recruitment of E2A to κE3′ is in part dependent on the transcription factor IRF-4. Inhibition of IRF-4 expression in pre-B cells leads to a significant reduction of Igκ germ line transcription and enhancer acetylation. In the absence of E2A, increased IRF-4 expression is not sufficient to promote Igκ enhancer chromatin modification or transcription, suggesting that the sequential involvement of IRF-4 and E2A is necessary for the activation of the Igκ locus. Finally, we provide genetic evidence in the mouse that E2A gene dosage can influence the development of pre-B cells during the phase of Igκ gene activation.

scholarly journals B-1a cells acquire their unique characteristics by bypassing the pre-BCR selection stage

2017 ◽  
Author(s):  
Jason B Wong ◽  
Susannah L Hewitt ◽  
Lynn M Heltemes-Harris ◽  
Malay Mandal ◽  
Kristen Johnson ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Fetal Liver ◽  
Cell Receptor ◽  
Cell Stage ◽  
Surrogate Light Chain ◽  
Immunoglobulin Kappa ◽  
Alternate Pathway ◽  
Receptor Repertoire ◽  
Selection Stage

SUMMARYB-1a cells are long-lived, self-renewing innate like B cells that predominantly inhabit the peritoneal and pleural cavities. In contrast to conventional B-2 cells they have a receptor repertoire that is biased towards bacterial and self-antigens, promoting a rapid response to infection and clearing of apoptotic cells. Although B-1a cells are known to primarily originate from fetal tissues the mechanisms by which they arise has been a topic of debate for many years. Here we show that in the fetal liver (FL) versus bone marrow (BM) environment, reduced IL-7R/STAT5 levels promote immunoglobulin kappa (Igk) recombination at the early pro-B cell stage. As a result, B cells can directly generate a mature B cell receptor (BCR) and bypass the requirement for a pre-BCR and pairing with surrogate light chain (SLC). This ‘alternate pathway’ of development enables the production of B cells with self reactive, skewed specificity receptors that are peculiar to the B-1a compartment. Together our findings connect seemingly opposing models of B-1a cell development and explain how these cells acquire their unique properties.

scholarly journals B-1a cells acquire their unique characteristics by bypassing the pre-BCR selection stage

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jason B. Wong ◽  
Susannah L. Hewitt ◽  
Lynn M. Heltemes-Harris ◽  
Malay Mandal ◽  
Kristen Johnson ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Fetal Liver ◽  
Cell Receptor ◽  
Cell Stage ◽  
Surrogate Light Chain ◽  
Immunoglobulin Kappa ◽  
Alternate Pathway ◽  
Receptor Repertoire ◽  
Selection Stage

Abstract B-1a cells are long-lived, self-renewing innate-like B cells that predominantly inhabit the peritoneal and pleural cavities. In contrast to conventional B-2 cells, B-1a cells have a receptor repertoire that is biased towards bacterial and self-antigens, promoting a rapid response to infection and clearing of apoptotic cells. Although B-1a cells are known to primarily originate from fetal tissues, the mechanisms by which they arise has been a topic of debate for many years. Here we show that in the fetal liver versus bone marrow environment, reduced IL-7R/STAT5 levels promote immunoglobulin kappa gene recombination at the early pro-B cell stage. As a result, differentiating B cells can directly generate a mature B cell receptor (BCR) and bypass the requirement for a pre-BCR and pairing with surrogate light chain. This ‘alternate pathway’ of development enables the production of B cells with self-reactive, skewed specificity receptors that are peculiar to the B-1a compartment. Together our findings connect seemingly opposing lineage and selection models of B-1a cell development and explain how these cells acquire their unique properties.

scholarly journals High frequency of lambda gene activation in bone marrow pre-B cells.

1984 ◽  
Vol 159 (2) ◽  
pp. 617-622 ◽  
Author(s):  
S I Nishikawa ◽  
T Kina ◽  
J I Gyotoku ◽  
Y Katsura
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Light Chain ◽  
High Frequency ◽  
Gene Activation ◽  
Lambda Light Chain ◽  
Cell Stage

The frequency of lambda light chain (L) producing cells in immunoglobulin-producing cells that have been generated in vitro from bone marrow pre-B cells was investigated. The frequency of lambda-producing cells obtained in such a culture was three- to eightfold higher than that observed in the culture of mature spleen B cells. These results suggest that the activation of lambda gene at pre-B cell stage occurs far more frequently than the frequency presumed from the percentage of lambda-bearing cells in mature B cells.

scholarly journals Ras Mediates Effector Pathways Responsible for Pre-B Cell Survival, Which Is Essential for the Developmental Progression to the Late Pre-B Cell Stage

2000 ◽  
Vol 192 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Hitoshi Nagaoka ◽  
Yoshimasa Takahashi ◽  
Reiko Hayashi ◽  
Tohru Nakamura ◽  
Kumiko Ishii ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Survival ◽  
Chain Gene ◽  
B Cell Differentiation ◽  
Antigen Receptors ◽  
Cell Stage ◽  
Light Chain Gene ◽  
B Cell Survival ◽  
Effector Pathways

Ras is essential for the transition from early B cell precursors to the pro-B stage, and is considered to be involved in the signal cascade mediated by pre-B cell antigen receptors. To examine the role of p21ras in the late stage of B cell differentiation, we established transgenic mice (TG) expressing a dominant-inhibitory mutant of Ha-ras (Asn-17 Ha-ras) in B lineage cells at high levels after the early B cell precursor stage. Expression of p21Asn-17 Ha-ras was associated with a prominent reduction in the number of late pre-B cells, but had little effect on proliferation of early pre-B cells. Inhibition of p21ras activity markedly reduced the life span of pre-B cells, due, at least in part, to downregulation of the expression of an antiapoptotic protein, Bcl-xL. Thus, the apparent role for p21ras activity in pre-B cell survival may explain the decreased numbers of late pre-B cells in Asn-17 Ha-ras TG. Consistent with this possibility, overexpression of Bcl-2 in Asn-17 Ha-ras TG reversed the reduction in the number of late pre-B cells undergoing immunoglobulin light chain gene (IgL) rearrangement and progressing to immature B cells. These results suggest that p21ras mediates effector pathways responsible for pre-B cell survival, which is essential for progression to the late pre-B and immature B stages.

scholarly journals Altered BCR and TLR signals promote enhanced positive selection of autoreactive transitional B cells in Wiskott-Aldrich syndrome

2015 ◽  
Vol 212 (10) ◽  
pp. 1663-1677 ◽  
Author(s):  
Nikita S. Kolhatkar ◽  
Archana Brahmandam ◽  
Christopher D. Thouvenel ◽  
Shirly Becker-Herman ◽  
Holly M. Jacobs ◽  
...  
Keyword(s):  
B Cells ◽  
Positive Selection ◽  
B Cell ◽  
Heavy Chain ◽  
High Throughput Sequencing ◽  
Cell Stage ◽  
Wiskott Aldrich Syndrome ◽  
Transitional B Cells ◽  
Selection Of

Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency disorder frequently associated with systemic autoimmunity, including autoantibody-mediated cytopenias. WAS protein (WASp)–deficient B cells have increased B cell receptor (BCR) and Toll-like receptor (TLR) signaling, suggesting that these pathways might impact establishment of the mature, naive BCR repertoire. To directly investigate this possibility, we evaluated naive B cell specificity and composition in WASp-deficient mice and WAS subjects (n = 12). High-throughput sequencing and single-cell cloning analysis of the BCR repertoire revealed altered heavy chain usage and enrichment for low-affinity self-reactive specificities in murine marginal zone and human naive B cells. Although negative selection mechanisms including deletion, anergy, and receptor editing were relatively unperturbed, WASp-deficient transitional B cells showed enhanced proliferation in vivo mediated by antigen- and Myd88-dependent signals. Finally, using both BCR sequencing and cell surface analysis with a monoclonal antibody recognizing an intrinsically autoreactive heavy chain, we show enrichment in self-reactive cells specifically at the transitional to naive mature B cell stage in WAS subjects. Our combined data support a model wherein modest alterations in B cell–intrinsic, BCR, and TLR signals in WAS, and likely other autoimmune disorders, are sufficient to alter B cell tolerance via positive selection of self-reactive transitional B cells.

scholarly journals IL-7 receptor signaling is necessary for stage transition in adult B cell development through up-regulation of EBF

2005 ◽  
Vol 201 (8) ◽  
pp. 1197-1203 ◽  
Author(s):  
Kazu Kikuchi ◽  
Anne Y. Lai ◽  
Chia-Lin Hsu ◽  
Motonari Kondo
Keyword(s):  
Transcription Factor ◽  
B Cells ◽  
B Cell ◽  
Target Genes ◽  
Cell Development ◽  
B Cell Development ◽  
Receptor Signaling ◽  
Cell Stage ◽  
Transcription Factor Network ◽  
Stage Transition

Cytokine receptor signals have been suggested to stimulate cell differentiation during hemato/lymphopoiesis. Such action, however, has not been clearly demonstrated. Here, we show that adult B cell development in IL-7−/− and IL-7Rα2/− mice is arrested at the pre–pro-B cell stage due to insufficient expression of the B cell–specific transcription factor EBF and its target genes, which form a transcription factor network in determining B lineage specification. EBF expression is restored in IL-7−/− pre–pro-B cells upon IL-7 stimulation or in IL-7Rα−/− pre–pro-B cells by activation of STAT5, a major signaling molecule downstream of the IL-7R signaling pathway. Furthermore, enforced EBF expression partially rescues B cell development in IL-7Rα−/− mice. Thus, IL-7 receptor signaling is a participant in the formation of the transcription factor network during B lymphopoiesis by up-regulating EBF, allowing stage transition from the pre–pro-B to further maturational stages.

scholarly journals Induction of metabolic quiescence defines the transitional to follicular B cell switch

2019 ◽  
Vol 12 (604) ◽  
pp. eaaw5573 ◽  
Author(s):  
Jocelyn R. Farmer ◽  
Hugues Allard-Chamard ◽  
Na Sun ◽  
Maimuna Ahmad ◽  
Alice Bertocchi ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Ampk Activation ◽  
Cell Stage ◽  
Extracellular Adenosine ◽  
Transitional B Cells ◽  
Follicular B Cells

Transitional B cells must actively undergo selection for self-tolerance before maturing into their resting follicular B cell successors. We found that metabolic quiescence was acquired at the follicular B cell stage in both humans and mice. In follicular B cells, the expression of genes involved in ribosome biogenesis, aerobic respiration, and mammalian target of rapamycin complex 1 (mTORC1) signaling was reduced when compared to that in transitional B cells. Functional metabolism studies, profiling of whole-cell metabolites, and analysis of cell surface proteins in human B cells suggested that this transition was also associated with increased extracellular adenosine salvage. Follicular B cells increased the abundance of the cell surface ectonucleotidase CD73, which coincided with adenosine 5′-monophosphate–activated protein kinase (AMPK) activation. Differentiation to the follicular B cell stage in vitro correlated with surface acquisition of CD73 on human transitional B cells and was augmented with the AMPK agonist, AICAR. Last, individuals with gain-of-function PIK3CD (PI3Kδ) mutations and increased pS6 activation exhibited a near absence of circulating follicular B cells. Together, our data suggest that mTORC1 attenuation may be necessary for human follicular B cell development. These data identify a distinct metabolic switch during human B cell development at the transitional to follicular stages, which is characterized by an induction of extracellular adenosine salvage, AMPK activation, and the acquisition of metabolic quiescence.

scholarly journals B lymphocytes express and lose syndecan at specific stages of differentiation.

1989 ◽  
Vol 1 (1) ◽  
pp. 27-35 ◽  
Author(s):  
R D Sanderson ◽  
P Lalor ◽  
M Bernfield
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
B Lymphocyte ◽  
Plasma Cells ◽  
Receptor Expression ◽  
Cell Stage ◽  
Precursor B Cells

Lymphopoietic cells require interactions with bone marrow stroma for normal maturation and show changes in adhesion to matrix during their differentiation. Syndecan, a heparan sulfate-rich integral membrane proteoglycan, functions as a matrix receptor by binding cells to interstitial collagens, fibronectin, and thrombospondin. Therefore, we asked whether syndecan was present on the surface of lymphopoietic cells. In bone marrow, we find syndecan only on precursor B cells. Expression changes with pre-B cell maturation in the marrow and with B-lymphocyte differentiation to plasma cells in interstitial matrices. Syndecan on B cell precursors is more heterogeneous and slightly larger than on plasma cells. Syndecan 1) is lost immediately before maturation and release of B lymphocytes into the circulation, 2) is absent on circulating and peripheral B lymphocytes, and 3) is reexpressed upon their differentiation into immobilized plasma cells. Thus, syndecan is expressed only when and where B lymphocytes associate with extracellular matrix. These results indicate that B cells differentiating in vivo alter their matrix receptor expression and suggest a role for syndecan in B cell stage-specific adhesion.

scholarly journals Growth- and differentiation-associated expression of bcl-2 in B-chronic lymphocytic leukemia cells

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2981-2989 ◽  
Author(s):  
M Schena ◽  
LG Larsson ◽  
D Gottardi ◽  
G Gaidano ◽  
M Carlsson ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Messenger Rna ◽  
Phorbol Esters ◽  
Lymphocytic Leukemia ◽  
Mantle Zone ◽  
Cell Stage ◽  
High Level

Abstract The bcl-2 gene is translocated into the Ig loci in about 80% of human follicular lymphomas and in 10% of B-type chronic lymphocytic leukemias (B-CLL), resulting in a high level of expression. We have compared the expression of bcl-2 transcripts and protein in B-CLL cells in their normal equivalent CD5+ B cells and in normal B-cell populations representative of different in vivo and in vitro stages of activation and proliferation. We report here that bcl-2 was expressed in 11 of 11 cases of CD5+ B-CLL clones, contrasting with the absent expression in normal CD5+ B cells. Activation of 173 and 183 B-CLL cells by phorbol esters (12-O-tetradecanoylphorbol-13-acetate [TPA]) to IgM secretion without concomitant DNA synthesis resulted in a rapid but transient downregulation of bcl-2 expression. In contrast, the reduction of bcl-2 at both the messenger RNA and protein levels was sustained after mitogenic stimulation, suggesting that bcl-2 expression and proliferation are inversely related in these cells. This notion was further supported by immunocytochemical analysis showing that bcl-2 was primarily expressed in small resting lymphocytes and in cells differentiating to the plasma cell stage, but less expressed in Ki67- positive proliferating B blasts. Moreover, it was also supported by the low level of bcl-2 in exponentially growing Epstein-Barr virus-carrying lymphoblastoid and B-CLL cell lines. The regulation of bcl-2 expression in B-CLL resembled that of normal tonsillar follicular B cells, in which a high level of expression was found in resting mantle zone B cells but not in the proliferating germinal center B cells. Based on these findings and the role of bcl-2 in maintaining B-cell memory, we propose that the phenotype of B-CLL cells corresponds to a mantle zone memory-type B cell.

The Proto-Oncogene LRF Is Essential for Normal Mature B Cell Development and Germinal Center Formation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1788-1788
Author(s):  
Nagisa Sakurai ◽  
Manami Maeda ◽  
Sung-UK Lee ◽  
Julie Teruya-Feldstein ◽  
Takahiro Maeda
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Cell Stage ◽  
Transitional B Cells ◽  
Notch Pathways ◽  
Secondary Lymphoid Organs

Abstract LRF (Leukemia/Lymphoma Related Factor, also known as Pokemon, FBI-1, OCZF and ZBTB7a) was originally identified as an interaction partner of the oncoprotein BCL6. LRF can act as a proto-oncogene by repressing the tumor suppressor ARF and cooperates with BCL6 in MEF (mouse embryonic fibroblasts) immortalization. It is highly expressed in human Non-Hodgkin Lymphoma (NHL) cases, in the pathogenesis of which BCL6 is known to be involved (Maeda et al. Nature 2005). Inducible inactivation of the LRF gene in mouse Hematopoietic Stem Cells (HSCs) results in complete block of early B cell development at the HSC/progenitor stages and concomitant development of double positive (DP) T cells in the bone marrow (BM) (Maeda et al. Science 2007). While these findings clearly illustrate key roles of LRF in normal and malignant B cell development, it is not fully identified as to which B cell stages LRF is required during normal B cell development. To elucidate the role of LRF in B cells in vivo, we established and characterized B cell-specific LRF conditional knockout (KO) mice. We took advantage of mb-1 Cre knock-in mice, in which Cre expression is restricted to the B cells after the ProB cell stage. B cell compartments in the BM (PreProB, ProB, PreB and immatureB) are grossly normal in LRFF/ Fmb1-Cre mice. The LRF gene was efficiently eliminated in BM CD19+ B cells revealed by quantitative real-time PCR assay. Furthermore, LRF protein was not detected in purified CD19+ B cells, but seen in CD19-non-B cells, confirming the specific inactivation of the LRF gene in B cells. Thus, despite its critical role at the HSC/progenitor stages, LRF was found to be dispensable for the survival of normal BM B cells. These findings are consistent with the fact that GSI treatment (Maeda et al. Science 2007) or Notch1 loss (Lee and Maeda, unpublished) rescues the defects in early B cell development seen in LRFF/FMx1-Cre+ mice. Notch signaling is necessary for the transitional B cells to commit to the marginal zone B cells (MZB). Inactivation of the component of the Notch pathways in mice results in no MZB development. On the contrary, deletion of the MINT/SHARP gene, a suppressor of Notch signaling, leads to increase of MZB cells and concomitant reduction of follicular B (FOB) cells, indicating that Notch induces MZB cell fate at the transitional B cell stage. Given that LRF is a potent Notch suppressor at the HSC/progenitor stages, we hypothesized that LRF opposes Notch pathway in mature B cells as well. To test this hypothesis, we characterized mature B cell development in LRFF/Fmb1-Cre mice. While transitional B cells were largely unaffected in LRFF/Fmb1-Cre mice, we observed a slight but statistically significant reduction of follicular (FO) B cells (B220+CD19+AA4.1-CD1d-CD23+) and concomitant increase of MZB cells (B220+CD19+AA4.1-CD1d+CD23-) as seen in MINT/SHARP knockout mice. Thus, LRF may also oppose Notch pathways at the branching point for the FOB vs. MZB fate decision. Finally, to determine the role of LRF in Germinal Center (GC) formation in vivo, we characterized secondary lymphoid organs of LRFF/Fmb1-Cre mice after antigen stimulation. Both spleen and Peyer’s Patches were analyzed two weeks after immunization with Chicken Gamma Globulin (NP-CGG). While a GC reaction was robustly induced in control mice upon immunization, GC formation was significantly impaired in LRFF/Fmb1-Cre mice as revealed by immuno-histochemical analysis (IHC) and FACS. Only few GC cells (B220+CD19+FAS+CD38-PNA+) were observed in spleens, and the absolute numbers of GC cells were drastically reduced in LRFF/Fmb1-Cre mice. Residual LRF-deficient GC B cells were mostly negative for CXCR4, which is predominantly expressed in proliferating centroblasts within GCs, suggesting that LRF-deficient GC B cells may have defects in cellular proliferation in response to antigen stimuli. Our data indicates that LRF plays key roles in mature B cell development in the secondary lymphoid organs, but dispensable for the maintenance of early BM B cells.

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