scholarly journals B-cell differentiation in the CBA/N mouse. I. Slower maturation of mitogen and antigen-responsive B cells in mice expressing an X-linked defect.

1979 ◽  
Vol 150 (6) ◽  
pp. 1483-1497 ◽  
Author(s):  
C A Whitlock ◽  
J D Watson
Keyword(s):  
B Cells ◽  
B Cell ◽  
Young Male ◽  
Lower Percentage ◽  
B Cell Differentiation ◽  
Male Mice ◽  
Spleen Cells ◽  
B Cell Precursors ◽  
Mitogen Activation ◽  
Effect Of Age

The effect of age on the mitogenic and antigenic responsiveness of B cells is examined in spleen cell cultures of CBA/N and (CBA/N X DBA/2) F1 mice. Spleen cells from young male F1 mice (4- to 6-wk old) show lower mitogenic responses to lipopolysaccharide, a lower frequency of sheep erythrocytes (SRBC)-reactive B-cell precursors, and a lower percentage of Ig-bearing cells than age-matched female F1 mice. The expression of all three functions were found to increase with the age of the F1 male mice. Whereas male F1 mice at 60 wk of age showed an equivalent percentage of Ig-bearing spleen cells and a similar mitogenic responsiveness to LPS when compared to adult female F1 mice, the frequency of SRBC-reactive B-cell precursors remained threefold lower. These findings reveal that there is a slower maturation of B cells in mice expressing the X-linked defect and suggests that the defect has differential effects on the mechanisms of antigen and mitogen activation of B cells.

scholarly journals CRAC Channel Controls the Differentiation of Pathogenic B Cells in Lupus Nephritis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xue Li ◽  
Qin Zeng ◽  
Shuyi Wang ◽  
Mengyuan Li ◽  
Xionghui Chen ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
Lupus Nephritis ◽  
B Cell ◽  
Lower Percentage ◽  
B Cell Differentiation ◽  
Channel Inhibition ◽  
Crac Channel

Store-operated Ca2+ release-activated Ca2+ (CRAC) channel is the main Ca2+ influx pathway in lymphocytes and is essential for immune response. Lupus nephritis (LN) is an autoimmune disease characterized by the production of autoantibodies due to widespread loss of immune tolerance. In this study, RNA-seq analysis revealed that calcium transmembrane transport and calcium channel activity were enhanced in naive B cells from patients with LN. The increased expression of ORAI1, ORAI2, and STIM2 in naive B cells from patients with LN was confirmed by flow cytometry and Western blot, implying a role of CRAC channel in B-cell dysregulation in LN. For in vitro study, CRAC channel inhibition by YM-58483 or downregulation by ORAI1-specific small-interfering RNA (siRNA) decreased the phosphorylation of Ca2+/calmodulin-dependent protein kinase2 (CaMK2) and suppressed Blimp-1 expression in primary human B cells, resulting in decreased B-cell differentiation and immunoglobulin G (IgG) production. B cells treated with CaMK2-specific siRNA showed defects in plasma cell differentiation and IgG production. For in vivo study, YM-58483 not only ameliorated the progression of LN but also prevented the development of LN. MRL/lpr lupus mice treated with YM-58483 showed lower percentage of plasma cells in the spleen and reduced concentration of anti-double-stranded DNA antibodies in the sera significantly. Importantly, mice treated with YM-58483 showed decreased immune deposition in the glomeruli and alleviated kidney damage, which was further confirmed in NZM2328 lupus mice. Collectively, CRAC channel controlled the differentiation of pathogenic B cells and promoted the progression of LN. This study provides insights into the pathogenic mechanisms of LN and that CRAC channel could serve as a potential therapeutic target for LN.

Inhibiton of mTOR by RAD001 Restores Normal B Cell Differentiation and Prevents B Cell Lymphomas in Eμ-MYC Mice.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2498-2498 ◽  
Author(s):  
Meaghan Wall ◽  
Gretchen Poortinga ◽  
Daniela Cardozo ◽  
Ricky W. Johnstone ◽  
Grant A. McArthur
Keyword(s):  
B Cells ◽  
Cell Growth ◽  
B Cell ◽  
Ribosome Biogenesis ◽  
Constitutive Expression ◽  
B Cell Lymphoma ◽  
B Cell Differentiation ◽  
Days Of Therapy ◽  
B Cell Subsets ◽  
B Cell Precursors

Abstract The c-Myc proto-oncogene encodes a bHLH-LZ transcription factor that regulates proliferation, differentiation and apoptosis. Deregulated expression of c-MYC is a frequent finding in a wide variety of human cancers, including B cell lymphoma. One emerging function of c-MYC is the regulation of ribosome biogenesis, protein synthesis and metabolism i.e. cell growth. mTOR, a key downstream signal transduction molecule in the PI3K/AKT growth regulatory pathway, is amenable to pharmacological inhibition by rapamycin analogues such as RAD001. We hypothesized that control of cell growth by c-MYC is important for its ability to regulate differentiation and act as an oncogene and that RAD001, by limiting cell growth, would attenuate the transforming properties of c-MYC. In Eμ-myc mice the c-myc transgene is under the control of the immunoglobulin heavy chain enhancer (Eμ). Constitutive expression of c-MYC results in a polyclonal expansion of B cell precursors followed by lymphoma development. In the current study ‘pre-lymphomatous’ Eμ-myc mice were randomized to receive RAD001 5mg/kg (n=20) or placebo (n=18) 6 days per week from 4 weeks of age. Peripheral blood B cells were analyzed by surface marker expression after 2, 4 and 8 weeks of therapy. Mice were monitored weekly for the development of lymphadenopathy. 2 weeks of treatment with RAD001 significantly reduced the numbers of B cells in the blood of Eμ-myc mice compared to placebo (1.37±0.13 ×103/μL in the RAD001 arm versus 3.41±0.64 ×103/μL in the placebo arm, p<0.05). In particular, there was preferential suppression of less mature circulating B cell precursors over mature B cells by RAD001 resulting in B cell developmental subset profiles more closely approaching those of wild-type mice (Figure 1). Treatment with RAD001 was associated with improved lymphoma-free survival; 13/14 lymphoma-free mice (92.9%) versus 6/11 (54.6%) in the placebo group in an interim analysis of mice that had received at least 60 days of therapy. These results indicate that RAD001 can firstly oppose the expansion of B cell precursors and secondly reduce the incidence of malignant transformation induced by deregulated expression of c-MYC in B lymphocytes. These findings have implications for the application of mTOR inhibitors in the treatment or prevention of malignancies associated with MYC. Figure 1. B cell subsets after weeks of therapy Figure 1. B cell subsets after weeks of therapy

scholarly journals Interleukin-1 inhibition of B lymphopoiesis is reversible

Blood ◽  
1988 ◽  
Vol 72 (6) ◽  
pp. 2053-2055 ◽  
Author(s):  
K Dorshkind
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Interleukin 1 ◽  
B Cell Differentiation ◽  
B Lymphopoiesis ◽  
Bone Marrow Cultures ◽  
B Cell Precursors ◽  
Marrow Cultures

Abstract Interleukin-1 (IL-1) has multiple effects on the hematopoietic system. The present data demonstrate that IL-1 and/or products induced by it reversibly suppress B-cell differentiation. Upon the addition of 50 U/mL (2.4 ng/mL) of recombinant IL-1 alpha (rIL-1 alpha) to lymphoid long-term bone marrow cultures at their initiation, very few B lymphocytes could be detected, and the majority of cells present were myeloid. This inhibition of B lymphopoiesis did not appear to be due to effects on proliferation of mature B cells because IL-1 did not affect the proliferative response of B cells to form B-cell colonies (CFU-B). The actions of the monokine were further examined by using myeloid and lymphoid long-term bone marrow culture systems. The transfer of myeloid long-term bone marrow cultures to lymphoid conditions usually results in the cessation of myelopoiesis and initiation of B lymphopoiesis. Exposure of early B-cell precursors present under the myeloid conditions to 50 U/mL of RIL-1 did not affect their subsequent differentiation into B cells upon transfer of the cultures to lymphoid conditions. However, myelopoiesis was sustained, and B lymphopoiesis did not initiate if 50 U/mL of rIL-1 was added to myeloid bone marrow cultures at the time of their transfer to the lymphoid conditions and during biweekly feedings thereafter. Upon removal of IL-1, myelopoiesis ceased, and B lymphopoiesis initiated. Thus, the effects of IL-1 on inhibition of B lymphopoiesis are reversible.

scholarly journals Loss of Bim Allows Precursor B Cell Survival But Not Precursor B Cell Differentiation in the Absence of Interleukin 7

2004 ◽  
Vol 200 (9) ◽  
pp. 1179-1187 ◽  
Author(s):  
Paula M. Oliver ◽  
Michael Wang ◽  
Yanan Zhu ◽  
Janice White ◽  
John Kappler ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Cell Survival ◽  
B Cell Differentiation ◽  
Normal Numbers ◽  
Cell Precursor ◽  
Interleukin 7 ◽  
B Cell Survival ◽  
B Cell Precursors

Interleukin (IL)-7 is a stromal cell–derived cytokine required for the survival, proliferation, and differentiation of B cell precursors. Members of the Bcl-2 family of proteins are known to have profound effects on lymphocyte survival, but not lymphocyte differentiation. To distinguish the relative dependence on IL-7 of B cell precursor survival versus B cell differentiation, the combined effects of lack of IL-7 and lack of the proapoptotic Bcl-2 relative, Bim, were studied. Bim is expressed to varying degrees in all B cell precursors and B cells. Lack of Bim compensated for lack of IL-7 in the survival of pro–, pre–, and immature B cells; however, lack of Bim did not substitute for the requirement for IL-7 in B cell precursor differentiation or B cell precursor proliferation. Precursor B cell survival is more dependent on sufficient levels of IL-7 than precursor B cell differentiation because the number of B cells and their precursors were reduced by half in mice heterozygous for IL-7 expression, but were restored to normal numbers in mice also lacking Bim. Hence, Bim and IL-7 work together to control the survival of B cell precursors and the number of B cells that exist in animals.

scholarly journals Rearrangement of exogenous immunoglobulin VH and DJH gene segments after retroviral transduction into immature lymphoid cell lines.

1988 ◽  
Vol 167 (2) ◽  
pp. 372-388 ◽  
Author(s):  
S V Desiderio ◽  
K R Wolff
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Common Mechanism ◽  
Chain Gene ◽  
B Cell Differentiation ◽  
Retroviral Transduction ◽  
Flanking Sequences ◽  
B Cell Precursors ◽  
Nucleotide Sequence Determination

A model substrate for the joining of Ig VH and DJH elements has been constructed in a retroviral vector carrying a selectable marker whose expression is independent of the arrangement of the resident Ig gene segments. The substrate was introduced into lymphoid and nonlymphoid cells, and site-specific recombination between the VH and DJH elements was monitored by a direct hybridization assay. Joining of the exogenous gene segments was observed in cell lines representative of three distinct stages in early B cell differentiation. Rearrangement was not observed in three cell lines derived from mature B cells, or in a fibroblastoid cell line. The VH and DJH elements were initially arranged so that the VH-DJH junction and the recombined flanking sequences could be recovered after rearrangement. By molecular cloning and nucleotide sequence determination, VH-DJH junctions formed upon rearrangement of the substrate were found to resemble closely similar junctions in functional H chain genes. The joining of VH and DJH elements was observed to be asymmetric; loss of nucleotides occurred at the coding joints, but not at the junctions between flanking sequences. Our results suggest that Ig H and L chain gene segments are joined by a common mechanism that is more active in B cell precursors than in mature B cells. These observations provide further evidence that the rearrangement of Ig gene segments occurs by a nonreciprocal recombinational mechanism. The model substrate described here is likely to be of use in defining the nucleotide sequences that mediate rearrangement and in examining the developmental specificity of this process.

scholarly journals Interleukin-1 inhibition of B lymphopoiesis is reversible

Blood ◽  
1988 ◽  
Vol 72 (6) ◽  
pp. 2053-2055
Author(s):  
K Dorshkind
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Interleukin 1 ◽  
B Cell Differentiation ◽  
B Lymphopoiesis ◽  
Bone Marrow Cultures ◽  
B Cell Precursors ◽  
Marrow Cultures

Interleukin-1 (IL-1) has multiple effects on the hematopoietic system. The present data demonstrate that IL-1 and/or products induced by it reversibly suppress B-cell differentiation. Upon the addition of 50 U/mL (2.4 ng/mL) of recombinant IL-1 alpha (rIL-1 alpha) to lymphoid long-term bone marrow cultures at their initiation, very few B lymphocytes could be detected, and the majority of cells present were myeloid. This inhibition of B lymphopoiesis did not appear to be due to effects on proliferation of mature B cells because IL-1 did not affect the proliferative response of B cells to form B-cell colonies (CFU-B). The actions of the monokine were further examined by using myeloid and lymphoid long-term bone marrow culture systems. The transfer of myeloid long-term bone marrow cultures to lymphoid conditions usually results in the cessation of myelopoiesis and initiation of B lymphopoiesis. Exposure of early B-cell precursors present under the myeloid conditions to 50 U/mL of RIL-1 did not affect their subsequent differentiation into B cells upon transfer of the cultures to lymphoid conditions. However, myelopoiesis was sustained, and B lymphopoiesis did not initiate if 50 U/mL of rIL-1 was added to myeloid bone marrow cultures at the time of their transfer to the lymphoid conditions and during biweekly feedings thereafter. Upon removal of IL-1, myelopoiesis ceased, and B lymphopoiesis initiated. Thus, the effects of IL-1 on inhibition of B lymphopoiesis are reversible.

scholarly journals Hyaluronate-CD44 Interactions Can Induce Murine B-Cell Activation

Blood ◽  
1997 ◽  
Vol 89 (8) ◽  
pp. 2901-2908 ◽  
Author(s):  
Asimah Rafi ◽  
Mitzi Nagarkatti ◽  
Prakash S. Nagarkatti
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Critical Role ◽  
Surface Glycoprotein ◽  
B Cell Differentiation ◽  
B Cell Activation ◽  
Cell Surface Glycoprotein ◽  
Immunodeficient Mice

Abstract CD44 is a widely distributed cell surface glycoprotein whose principal ligand has been identified as hyaluronic acid (HA), a major component of the extracellular matrix (ECM). Recent studies have demonstrated that activation through CD44 leads to induction of effector function in T cells and macrophages. In the current study, we investigated whether HA or monoclonal antibodies (MoAbs) against CD44 would induce a proliferative response in mouse lymphocytes. Spleen cells from normal and nude, but not severe combined immunodeficient mice, exhibited strong proliferative responsiveness to stimulation with soluble HA or anti-CD44 MoAbs. Furthermore, purified B cells, but not T cells, were found to respond to HA. HA was unable to stimulate T cells even in the presence of antigen presenting cells (APC) and was unable to act as a costimulus in the presence of mitogenic or submitogenic concentrations of anti-CD3 MoAbs. In contrast, stimulation of B cells with HA in vitro, led to B-cell differentiation as measured by production of IgM antibodies in addition to increased expression of CD44 and decreased levels of CD45R. The fact that the B cells were responding directly to HA through its binding to CD44 and not to any contaminants or endotoxins was demonstrated by the fact that F(ab)2 fragments of anti-CD44 MoAbs or soluble CD44 fusion proteins could significantly inhibit the HA-induced proliferation of B cells. Also, HA-induced proliferation of B cells was not affected by the addition of polymixin B, and B cells from lipopolysaccharide (LPS)-unresponsive C3H/HeJ strain responded strongly to stimulation with HA. Furthermore, HA, but not chondroitin-sulfate, another major component of the ECM, induced B-cell activation. It was also noted that injection of HA intraperitoneally, triggered splenic B cell proliferation in vivo. Together, the current study demonstrates that interaction between HA and CD44 can regulate murine B-cell effector functions and that such interactions may play a critical role during normal or autoimmune responsiveness of 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 A MOUSE B-CELL ALLOANTIGEN DETERMINED BY GENE(S) LINKED TO THE MAJOR HISTOCOMPATIBILITY COMPLEX

1973 ◽  
Vol 138 (6) ◽  
pp. 1289-1304 ◽  
Author(s):  
David H. Sachs ◽  
James L. Cone
Keyword(s):  
Major Histocompatibility Complex ◽  
Lymph Node ◽  
T Cell ◽  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Surface Antigen ◽  
Major Histocompatibility ◽  
Spleen Cells ◽  
Histocompatibility Complex

Antibodies cytotoxic for only a subpopulation of C57Bl/10 lymph node and spleen cells were detected when rat antiserum against B10.D2 was exhaustively absorbed with B10.A lymphocytes. Antibodies of similar specificity were also detected in B10.A anti-B10.D2 and in B10.A anti-C57Bl/10 alloantisera. Reactions with recombinant strains of mice indicate that the cell-surface antigen(s) responsible for this specificity is determined by gene(s) in or to the left of the Ir-1 region of the major histocompatibility complex. A variety of criteria implicate B cells as the subpopulation of lymphocytes bearing this antigen. In view of these data and the recent report by others of a T-cell alloantigen determined by gene(s) in the major histocompatibility complex, it seems possible that there may be a variety of H-2-linked alloantigens expressed preferentially on subclasses of lymphocytes.

AB0144 STRATIFICATION OF PATIENTS WITH PRIMARY SJÖGREN’S SYNDROME BY MEASURING B-CELL HEALTH

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1372-1373
Author(s):  
G. M. Verstappen ◽  
J. C. Tempany ◽  
H. Cheon ◽  
A. Farchione ◽  
S. Downie-Doyle ◽  
...  
Keyword(s):  
Cell Division ◽  
Cell Differentiation ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
B Cell Differentiation ◽  
Research Support ◽  
Differentiation Capacity ◽  
Cell Responses ◽  
Healthy Donors

Background:Primary Sjögren’s syndrome (pSS) is a heterogeneous immune disorder with broad clinical phenotypes that can arise from a large number of genetic, hormonal, and environmental causes. B-cell hyperactivity is considered to be a pathogenic hallmark of pSS. However, whether B-cell hyperactivity in pSS patients is a result of polygenic, B cell-intrinsic factors, extrinsic factors, or both, is unclear. Despite controversies about the efficacy of rituximab, new B-cell targeting therapies are under investigation with promising early results. However, for such therapies to be successful, the etiology of B-cell hyperactivity in pSS needs to be clarified at the individual patient level.Objectives:To measure naïve B-cell function in pSS patients and healthy donors using quantitative immunology.Methods:We have developed standardised, quantitative functional assays of B-cell responses that measure division, death, differentiation and isotype switching, to reveal the innate programming of B cells in response to T-independent and dependent stimuli. This novel pipeline to measure B-cell health was developed to reveal the sum total of polygenic defects and underlying B-cell dysfunction at an individual level. For the current study, 25 pSS patients, fulfilling 2016 ACR-EULAR criteria, and 15 age-and gender-matched healthy donors were recruited. Standardized quantitative assays were used to directly measure B cell division, death and differentiation in response to T cell-independent (anti-Ig + CpG) and T-cell dependent (CD40L + IL-21) stimuli. Naïve B cells (IgD+CD27-) were sorted from peripheral blood mononuclear cells and were labeled with Cell Trace Violet at day 0 to track cell division until day 6. B cell differentiation was measured at day 5.Results:Application of our standardized assays, and accompanying parametric models, allowed us to study B cell-intrinsic defects in pSS patients to a range of stimuli. Strikingly, we demonstrated a hyperresponse of naïve B cells to combined B cell receptor (BCR) and Toll-like receptor (TLR)-9 stimulation in pSS patients. This hyperresponse was revealed by an increased mean division number (MDN) at day 5 in pSS patients compared with healthy donors (p=0.021). A higher MDN in pSS patients was observed at the cohort level and was likely attributed to an increased division burst (division destiny) time. The MDN upon BCR/TLR-9 stimulation correlated with serum IgG levels (rs=0.52; p=0.011). No difference in MDN of naïve B cells after T cell-dependent stimulation was observed between pSS patients and healthy donors. B cell differentiation capacity (e.g., plasmablast formation and isotype switching) after T cell-dependent stimulation was also assessed. At the cohort level, no difference in differentiation capacity between groups was observed, although some pSS patients showed higher plasmablast frequencies than healthy donors.Conclusion:Here, we demonstrate defects in B-cell responses both at the cohort level, as well as individual signatures of defective responses. Personalized profiles of B cell health in pSS patients reveal a group of hyperresponsive patients, specifically to combined BCR/TLR stimulation. These patients may benefit most from B-cell targeted therapies. Future studies will address whether profiles of B cell health might serve additional roles, such as prediction of disease trajectories, and thus accelerate early intervention and access to precision therapies.Disclosure of Interests:Gwenny M. Verstappen: None declared, Jessica Catherine Tempany: None declared, HoChan Cheon: None declared, Anthony Farchione: None declared, Sarah Downie-Doyle: None declared, Maureen Rischmueller Consultant of: Abbvie, Bristol-Meyer-Squibb, Celgene, Glaxo Smith Kline, Hospira, Janssen Cilag, MSD, Novartis, Pfizer, Roche, Sanofi, UCB, Ken R. Duffy: None declared, Frans G.M. Kroese Grant/research support from: Unrestricted grant from Bristol-Myers Squibb, Consultant of: Consultant for Bristol-Myers Squibb, Speakers bureau: Speaker for Bristol-Myers Squibb, Roche and Janssen-Cilag, Hendrika Bootsma Grant/research support from: Unrestricted grants from Bristol-Myers Squibb and Roche, Consultant of: Consultant for Bristol-Myers Squibb, Roche, Novartis, Medimmune, Union Chimique Belge, Speakers bureau: Speaker for Bristol-Myers Squibb and Novartis., Philip D. Hodgkin Grant/research support from: Medimmune, Vanessa L. Bryant Grant/research support from: CSL

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