Cell surface expression of surrogate light chain (ΨL) in the absence of μ on human pro-B cell lines and normal pro-B cells

1996 ◽  
Vol 26 (9) ◽  
pp. 2172-2180 ◽  
Author(s):  
Eric Meffre ◽  
Michel Fougereau ◽  
Jean-Noël Argenson ◽  
Jean-Manuel Aubaniac ◽  
Claudine Schiff
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Lines ◽  
Light Chain ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Surrogate Light Chain

scholarly journals Carbohydrate-dependent B cell activation by fucose-binding bacterial lectins

2019 ◽  
Vol 12 (571) ◽  
pp. eaao7194 ◽  
Author(s):  
Isabel Wilhelm ◽  
Ella Levit-Zerdoun ◽  
Johanna Jakob ◽  
Sarah Villringer ◽  
Marco Frensch ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Activation ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
B Cell Activation ◽  
Intracellular Ca ◽  
Bacterial Lectins

Bacterial lectins are typically multivalent and bind noncovalently to specific carbohydrates on host tissues to facilitate bacterial adhesion. Here, we analyzed the effects of two fucose-binding lectins, BambL fromBurkholderia ambifariaand LecB fromPseudomonas aeruginosa, on specific signaling pathways in B cells. We found that these bacterial lectins induced B cell activation, which, in vitro, was dependent on the cell surface expression of the B cell antigen receptor (BCR) and its co-receptor CD19, as well as on spleen tyrosine kinase (Syk) activity. The resulting release of intracellular Ca2+was followed by an increase in the cell surface abundance of the activation marker CD86, augmented cytokine secretion, and subsequent cell death, replicating all of the events that are observed in vitro upon canonical and antigen-mediated B cell activation. Moreover, injection of BambL in mice resulted in a substantial, BCR-independent loss of B cells in the bone marrow with simultaneous, transient enlargement of the spleen (splenomegaly), as well as an increase in the numbers of splenic B cells and myeloid cells. Together, these data suggest that bacterial lectins can initiate polyclonal activation of B cells through their sole capacity to bind to fucose.

Pre-B cell receptor expression in B-lineage acute lymphoblastic leukemia: A report from the Children’s Oncology Group.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e19006-e19006
Author(s):  
Stuart S. Winter ◽  
Amanda McCaustland ◽  
No'eau Simeona ◽  
Andrew J. Carroll ◽  
Nyla A. Heerema ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Light Chain ◽  
Lymphoblastic Leukemia ◽  
Surface Expression ◽  
Oncology Group ◽  
Surrogate Light Chain ◽  
Cell Ablation ◽  
B Lineage

e19006 Background: The surface expression of mature B-cell markers have led to the development of immunotherapies against B-lineage lymphoblastic leukemia/lymphoma (B-ALL/B-LLy). Relapsing clones that have altered surface antigen expression are common means of treatment failure with immunotherapies. The elimination of the pan-B cell repertoire by current B-cell immunotherapies contributes to immune-compromise. A promising target is the pre-BCR surrogate light chain, comprised of the VpreB1 (CD179a) and Lamda5 (CD179b) subunits. Surrogate light chain is expressed on pro- and pre-B cells where it governs preBCR-mediated autonomous survival during B-cell maturation. Gene expression analyses have shown that CD179a is expressed in a sub-set of 10 to 15% of B-ALL cases. Because immunotherapies targeted to restricted stages of B-cell development may overcome the limitations of pan B-cell ablation, we tested the hypothesis that CD179a is more commonly expressed on B-lymphoblasts than previously thought. Methods: Utilizing an annotated set of 36 standard (AALL0331) and high-risk (AALL0232) B-ALL cases accrued to Children’s Oncology Group AALL03B1, we adapted the COG minimal residual disease (MRD) flow panel to include two additional PE- and FITC-conjugated mAbs against CD179a (Biolegend and i2Pharma). We assessed CD179a expression in 16 cases for which we had Day 28 end-induction samples, pre-selected to have ≥1% MRD, as determined by the COG Reference laboratories. Cases with ≥20% CD179a surface expression were determined to be positive for statistical comparisons. All analyses were performed on a 6-color Becton-Dickinson flow cytometer in a CLIA/CAP certified laboratory. Results: Thirty-four cases were arrested at the CD10-positive pre-B stage, and two cases at the CD10-negative pro-B stage. One or both mAbs showed that CD179a was present in ≥20% of the B-lymphoblast population, ranging from 20.2% to 90.6% for all 36 diagnostic samples. All cases expressed CD179a in the end-induction B-lymphoblast population. Compared to gene-expression based predictions, we found a significant difference between expected versus observed flow-based CD179a positivity (two-sided Fisher’s exact test, P< 0.001). We found that CD179a expression was observed in cases having E2A-PBX3, KMT2A, BCR-ABL1 and other re-arrangements that typify mixed phenotype acute leukemias (MPALs). Conclusions: Our results show that CD179a is commonly expressed in B-ALL, regardless of stage, NCI risk features, or molecular aberrations. Because the productively assembled preBCR mediates autonomous survival signaling in pro- and pre-B cells, it may also contribute to the mechanistic basis of MRD in B-ALL. Immunotherapies directed against the CD179a component of the preBCR may spare the immune-compromise that occurs with pan B-cell ablation, and prevent the emergence of therapy-resistant disease in B-ALL/B-LLy.

CD81-Dependent Trafficking of CD19: Restoration of CD19 Surface Expression in Human B Cells Harboring A CD81 Mutation

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1049-1049
Author(s):  
Shoshana Levy ◽  
Chiung-Chi Kuo ◽  
Yael Sagi ◽  
Homer Chen ◽  
Neta Kela-Madar ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Line ◽  
Conflicts Of Interest ◽  
Surface Expression ◽  
Antibody Deficiency ◽  
Cell Surface Expression ◽  
Dominant Negative Effect ◽  
Proximity Ligation Assay

Abstract Abstract 1049 Introduction: A 6-year-old girl, who was diagnosed with a primary antibody deficiency, had B cells lacking surface CD19. However, both her CD19 alleles were normal and the impairment was actually caused by a homozygous exon splice site mutation in CD81 (1). The patient's B cells also lacked surface CD81 and produced an immature glycosylated CD19 protein that was retained intracellularly. Interestingly, this human deficiency differed from that of CD81 knockout mice as the latter still express a low level of CD19 on their B cells. Methods: We used an EBV-transformed B cell line from this patient to better understand i) the difference between the human and mouse CD81 deficiencies and ii) how CD81 controls the trafficking of CD19 to the cell surface. We reasoned that the truncated human CD81 mutant (CD81mut) protein might be expressed intracellularly. Indeed, whereas most anti-CD81 mAbs did not recognize CD81mut, we identified one that bound the mutated form and used it in this study. We also expressed the human CD81mut in a CD81-deficient mouse B cell line to determine if it could negatively regulate CD19 surface expression. Results: We show that the CD81mut protein is indeed expressed intracellularly in the patient's EBV-transformed B cells. We then used a proximity ligation assay to demonstrate that the truncated CD81mut protein interacts intracellularly with CD19. However, this interaction with the CD81mut protein abrogated carbohydrate maturation and the trafficking of CD19 to cell surface. We therefore expressed the CD81mut in CD81KO mouse B cells, which still express low levels of surface CD19, and found that it did not exert a dominant negative effect on CD19 surface expression. Finally, we used this reconstitution system to identify specific CD81 domains that restored carbohydrate maturation and cell surface expression of the CD19 molecule in the patient's B cells. Conclusion: This specific case of antibody deficiency was manifested because of lack of surface expression of CD19, an important B cell signaling molecule. However, the maturation of CD19 and its trafficking to the cell surface require the presence of specific domains of the tetraspanin CD81 molecule. Disclosures: No relevant conflicts of interest to declare.

Requirement for MD-1 in cell surface expression of RP105/CD180 and B-cell responsiveness to lipopolysaccharide

Blood ◽  
2002 ◽  
Vol 99 (5) ◽  
pp. 1699-1705 ◽  
Author(s):  
Yoshinori Nagai ◽  
Rintaro Shimazu ◽  
Hirotaka Ogata ◽  
Sachiko Akashi ◽  
Katsuko Sudo ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Activation ◽  
Costimulatory Molecule ◽  
Structural Similarity ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Cell Surface Molecule

RP105 is a B-cell surface molecule that has been recently assigned as CD180. RP105 ligation with an antibody induces B-cell activation in humans and mice, leading to proliferation and up-regulation of a costimulatory molecule, B7.2/CD86. RP105 is associated with an extracellular molecule, MD-1. RP105/MD-1 has structural similarity to Toll-like receptor 4 (TLR4)/MD-2. TLR4 signals a membrane constituent of Gram-negative bacteria, lipopolysaccharide (LPS). MD-2 is indispensable for TLR4-dependent LPS responses because cells expressing TLR4/MD-2, but not TLR4 alone, respond to LPS. RP105 also has a role in LPS responses because B cells lacking RP105 show hyporesponsiveness to LPS. Little is known, however, regarding whether MD-1 is important for RP105-dependent LPS responses, as MD-2 is for TLR4. To address the issue, we developed mice lacking MD-1 and generated monoclonal antibodies (mAbs) to the protein. MD-1–null mice showed impairment in LPS-induced B-cell proliferation, antibody production, and B7.2/CD86 up-regulation. These phenotypes are similar to those of RP105-null mice. The similarity was attributed to the absence of cell surface RP105 on MD-1–null B cells. MD-1 is indispensable for cell surface expression of RP105. A role for MD-1 in LPS responses was further studied with anti–mouse MD-1 mAbs. In contrast to highly mitogenic anti-RP105 mAbs, the mAbs to MD-1 were not mitogenic but antagonistic on LPS-induced B-cell proliferation and on B7.2 up-regulation. Collectively, MD-1 is important for RP105 with respect to B-cell surface expression and LPS recognition and signaling.

RP105 Is Associated With MD-1 and Transmits an Activation Signal in Human B Cells

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2815-2822 ◽  
Author(s):  
Yoshihiro Miura ◽  
Rintaro Shimazu ◽  
Kensuke Miyake ◽  
Sachiko Akashi ◽  
Hirotaka Ogata ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Activation ◽  
Costimulatory Molecule ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
B Cell Activation ◽  
Cell Surface Molecule ◽  
Induced Apoptosis

Abstract RP105 was originally discovered as a mouse B-cell surface molecule that transmits an activation signal. The signal leads to resistance against irradiation-induced apoptosis and massive B-cell proliferation. Recently, we found that mouse RP105 is associated with another molecule, MD-1. We have isolated here the human MD-1 cDNA. We show that human MD-1 is also associated with human RP105 and has an important role in cell surface expression of RP105. We also describe a monoclonal antibody (MoAb) that recognizes human RP105. Expression of RP105 is restricted to CD19+ B cells. Histological studies showed that RP105 is expressed mainly on mature B cells in mantle zones. Germinal center cells are either dull or negative. RP105 is thus a novel human B-cell marker that is preferentially expressed on mature B cells. Moreover, the anti-RP105 MoAb activates B cells, leading to increases in cell size, expression of a costimulatory molecule CD80, and DNA synthesis. The B-cell activation pathway using RP105 is conserved in humans. © 1998 by The American Society of Hematology.

scholarly journals Stromal-Cell and Cytokine-Dependent Lymphocyte Clones Which Span the Pre-B- to B-Cell Transition

1991 ◽  
Vol 1 (3) ◽  
pp. 149-161 ◽  
Author(s):  
Katsuhiko Ishihara ◽  
Kay Medina ◽  
Shin-Ichi Hayashi ◽  
Carolynn Pietrangeli ◽  
Anthony E. Namen ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Light Chain ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Cell Clone ◽  
Chain Complex ◽  
Immunodeficient Mice ◽  
Surrogate Light Chain

Five stromal-cell-dependent lymphocyte clones are described that correspond to late pre-B or early B-cell stages of differentiation.They are useful for determining the molecular requirements for pre-B replication, for studying the stromal cells that supply those factors, and for delineating the final sequence of differentiation events as newly formed lymphocytes prepare to exit the bone marrow. The efficiency of lymphocyte growth at limiting dilution varied substantially on different stromal-cell clones and may reflect functional heterogeneity of stromal cells. Most lymphocyte clones were similar to uncloned lymphocytes from Whitlock-Witte cultures in that they responded only transiently to interleukin-7 (IL-7) and then died, unless maintained on a stromal-cell clone. One unusual lymphocyte clone (2E8) was propagated for more than 1 year in IL-7 alone and was selectively responsive to that cytokine. Most of the lymphocyte clones were not tumorigenic in immunodeficient mice. However, one pre-B clone (1A9)’grew autonomously in culture when held at high density, responded to conditioned medium from a number of cell lines, and was tumorigenic. Tumors derived from this clone were infiltrated by stromal cells and lymphocytes taken from the tumors' retained characteristics of the original clone. Ly-6 antigens were inducible on 2E8 and 1A9 cells, but the lymphocytes were otherwise arrested in differentiation. The 2E8 cells had rearranged and expressedκlight-chain genes but displayed them on the surface along with surrogate light chains andμheavy chains. Thus, expression of authentic Tight chain need not coincide with termination of surrogate light-chain utilization in newly formed B cells. Several glycoproteins have recently been demonstrated to be associated with surface immunoglobulin (Ig) on mature B-lineage cells and plasma-cell tumors. We now show that one member of this family (approximately 33 kD) was associated with theμ+surrogate light-chain complex on the 1A9 pre-B-cell clone. When compared to mature B lymphomas, fewer bands coprecipitated with the surface-labeled Ig isolated from pre-B- and early B-cell lines, suggesting that components of the antigen receptor are sequentially acquired during development. The normal replication and differentiation of pre-B cells is probably regulated by complex interactions with multiple cytokines and matrix components of the marrow microenvironment. Cloned lymphocyte lines that are dependent on stromal cells should continue to be important tools for molecular definition of those interactions.

CD150 AND CD180 ARE INVOLVED IN REGULATION OF TRANSCRIPTION FACTORS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA CELLS

2017 ◽  
Vol 39 (4) ◽  
pp. 291-298 ◽  
Author(s):  
I M Gordienko ◽  
L M Shlapatska ◽  
V M Kholodniuk ◽  
L M Kovalevska ◽  
T S Ivanivskaya ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Surface ◽  
B Cell ◽  
Mrna Expression ◽  
Mrna Level ◽  
Surface Expression ◽  
Lymphocytic Leukemia ◽  
Cell Surface Expression ◽  
B Lineage

Background: Sequential stages of B-cell development is stringently coordinated by transcription factors (TFs) network that include B-lineage commitment TFs (Ikaros, Runx1/Cbfb, E2A, and FOXO1), B-lineage maintenance TFs (EBF1 and PAX5) and stage specific set of TFs (IRF4, IRF8, BCL6, BLIMP1). Deregulation of TFs expression and activity is often occurs in malignant B cells. The aim of this study was to evaluate TFs expression in chronic lymphocytic leukemia cells taking into consideration CD150 cell surface expression. From other side we attempted to regulate TFs expression via CD150 and CD180 cell surface receptors. Materials and Methods: Studies were performed on normal peripheral blood B-cell subpopulations and chronic lymphocytic leukemia (CLL) cells isolated from peripheral blood of 67 primary untreated patients with CLL. Evaluation of TFs expression was performed on mRNA level using qRT-PCR and on protein level by western blot analysis. Results: Median of PAX5 and EBF1 mRNA expression was higher in cell surface CD150 positive (csCD150+) compared to csCD150- CLL cases or normal CD19+ and CD19+CD5+ B-cell subsets. Differences in mRNA expression of IRF8, IRF4 and BLIMP1 between studied groups of CLL and normal B cells were not revealed. All CLL cases were characterized by downregulated expression of PU.1 and BCL6 mRNAs in comparison to normal B cells. At the same time elevated SPIB mRNA expression level was restricted to CLL cells. Protein expression of IRF4, IRF8 and BCL6 was uniformly distributed between csCD150- and csCD150+ CLL cases. PU.1 protein and CD20 that is direct PU.1 target gene positively correlated with CD150 cell surface expression on CLL cells. Ligation of CD150 and CD180 alone or in combination upregulated IRF8 and PU.1 while downregulated the IRF4 mRNA expression. Signaling via CD150 or CD180 alone elevated the level of BCL6 mRNA. Strong downregulation of IRF4 mRNA was observed after CD150, CD180 or CD150 and CD180 coligation on CLL cells. We found that in CLL cells CD150 is a negative regulator of SPIB while CD180 is involved in upregulation of EBF1 expression level. Moreover, CD180 ligation on CLL cells caused increase of CD150 mRNA level that is a one of the EBF1 target genes. Conclusions: Analysis of TFs expression profile revealed upregulated SPIB mRNA level and downregulated PU.1 in CLL cells. CD150 and CD180 receptors may modulate transcriptional program in CLL cells by regulating the TFs expression levels.

RP105 Is Associated With MD-1 and Transmits an Activation Signal in Human B Cells

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2815-2822 ◽  
Author(s):  
Yoshihiro Miura ◽  
Rintaro Shimazu ◽  
Kensuke Miyake ◽  
Sachiko Akashi ◽  
Hirotaka Ogata ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Activation ◽  
Costimulatory Molecule ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
B Cell Activation ◽  
Cell Surface Molecule ◽  
Induced Apoptosis

RP105 was originally discovered as a mouse B-cell surface molecule that transmits an activation signal. The signal leads to resistance against irradiation-induced apoptosis and massive B-cell proliferation. Recently, we found that mouse RP105 is associated with another molecule, MD-1. We have isolated here the human MD-1 cDNA. We show that human MD-1 is also associated with human RP105 and has an important role in cell surface expression of RP105. We also describe a monoclonal antibody (MoAb) that recognizes human RP105. Expression of RP105 is restricted to CD19+ B cells. Histological studies showed that RP105 is expressed mainly on mature B cells in mantle zones. Germinal center cells are either dull or negative. RP105 is thus a novel human B-cell marker that is preferentially expressed on mature B cells. Moreover, the anti-RP105 MoAb activates B cells, leading to increases in cell size, expression of a costimulatory molecule CD80, and DNA synthesis. The B-cell activation pathway using RP105 is conserved in humans. © 1998 by The American Society of Hematology.

scholarly journals AB0024 IN VITRO CHARACTERIZATION OF CENERIMOD, A POTENT AND SELECTIVE SPHINGOSINE 1-PHOSPHATE RECEPTOR 1 (S1P1) MODULATOR IN PREVENTING MIGRATION OF NON-ACTIVATED AND ACTIVATED PRIMARY HUMAN B CELLS IN THE PRESENCE OR ABSENCE OF GLUCOCORTICOIDS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1046.1-1046
Author(s):  
L. Schlicher ◽  
P. Kulig ◽  
M. Murphy ◽  
M. Keller
Keyword(s):  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Cell Activation ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
B Cell Activation ◽  
Human B Cells ◽  
Circulating Lymphocytes

Background:Cenerimod is a potent, selective, and orally active sphingosine 1-phosphate receptor 1 (S1P1) modulator that is currently being evaluated in a Phase 2b study in patients with systemic lupus erythematosus (SLE) (NCT03742037). S1P1 receptor modulators sequester circulating lymphocytes within lymph nodes, thereby reducing pathogenic autoimmune cells (including B lymphocytes) in the blood stream and in inflamed tissues. Extensive clinical experience has become available for the nonselective S1P receptor modulator fingolimod in relapsing forms of multiple sclerosis, supporting this therapeutic concept for the treatment of autoimmune disorders.Objectives:Although the effect of S1P-receptor modulators in reducing peripheral B cells is well documented1,2, the role of the S1P1 receptor on this cell type is only incompletely understood. In this study, the mode of action of cenerimod on primary human B cells was investigated in a series of in vitro experiments, including S1P1 receptor cell surface expression and chemotaxis towards S1P. Moreover, S1P1 expression following B cell activation in vitro was studied. As glucocorticoids (GC) are frequently used in the treatment of patients with autoimmune disorders including SLE, the potential influence of GC on the mode of action of cenerimod was evaluated.Methods:Primary human B lymphocytes from healthy donors were isolated from whole blood. In one set of experiments, cells were treated with different concentrations of cenerimod to measure S1P1 receptor internalization by flow cytometry. In a second set of experiments, isolated B cells were activated using different stimuli or left untreated. Cells were then analysed for S1P1 and CD69 cell surface expression and tested in a novel real-time S1P-mediated migration assay. In addition, the effect of physiological concentrations of GCs (prednisolone and prednisone) on cenerimod activity in preventing S1P mediated migration was tested.Results:In vitro, cenerimod led to a dose-dependent internalization of the S1P1 receptor on primary human B lymphocytes. Cenerimod also blocked migration of nonactivated and activated B lymphocytes towards S1P in a concentration-dependent manner, which is in line with the retention of lymphocytes in the lymph node and the reduction of circulating lymphocytes observed in the clinical setting. Upon B cell activation, which was monitored by CD69 upregulation, a simultaneous downregulation of S1P1 expression was detected, leading to less efficient S1P-directed cell migration. Importantly, physiological concentrations of GC did not affect the inhibitory activity of cenerimod on B cell migration.Conclusion:These results show that cenerimod, by modulating S1P1, blocks B lymphocyte migration towards its natural chemoattractant S1P and demonstrate compatibility of cenerimod with GC. These results are consistent with results of comparable experiments done previously using primary human T lymphocytes.References:[1]Nakamura M et al., Mult Scler. 2014 Sep; 20(10):1371-80.[2]Strasser DS et al., RMD Open 2020;6:e001261.Disclosure of Interests:None declared

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