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Shimizu T, Sun L, Ohnishi K. Influence of pre-B cell receptor deficiency on the immunoglobulin repertoires in peripheral blood B cells before and after immunization. Mol Immunol 2024; 166:87-100. [PMID: 38271880 DOI: 10.1016/j.molimm.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/17/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024]
Abstract
During B cell development, pre-B cell receptor (pre-BCR), comprising the immunoglobulin heavy chain (HC) and surrogate light chain (SLC), plays a crucial role. The expression of pre-BCR serves as a certification of HC quality, confirming its ability to associate with the SLC and light chain (LC). In mice lacking SLC, the absence of this quality control mechanism leads to a distorted repertoire of HCs in the spleen and bone marrow. In this study, we conducted a comparative analysis of the immunoglobulin gene repertoire in peripheral blood cells of both wild-type mice and pre-BCR-deficient mice. Our findings reveal differences not only in the μ HC repertoire but also in the α HC and κ LC repertoires of the pre-BCR-deficient mice. These results suggest that the pre-BCR-mediated quality check of HC influences the selection of class-switched HC and LC repertoires. To further explore the impact of pre-BCR deficiency, we immunized these mice with thymus-dependent antigens and compared the antigen-responding repertoires. Our observations indicate that the affinity maturation pathways remain consistent between wild-type mice and pre-BCR-deficient mice, albeit with variations in the degree of maturation.
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Affiliation(s)
- Takeyuki Shimizu
- Department of Immunology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan.
| | - Lin Sun
- Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan
| | - Kazuo Ohnishi
- Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan
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2
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van Loo PF, Dingjan GM, Maas A, Hendriks RW. Surrogate-light-chain silencing is not critical for the limitation of pre-B cell expansion but is for the termination of constitutive signaling. Immunity 2007; 27:468-80. [PMID: 17869135 DOI: 10.1016/j.immuni.2007.07.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/18/2007] [Accepted: 07/20/2007] [Indexed: 11/28/2022]
Abstract
The pre-B cell receptor (pre-BCR), composed of immunoglobulin mu heavy chain and the surrogate light chain (SLC) proteins lambda5 and Vpreb, signals for proliferation and maturation of developing pre-B cells. It has been assumed that pre-B cells stop cycling by the pre-BCR-mediated downregulation of SLC transcription. We generated transgenic mice expressing SLC throughout B cell development and, remarkably, found that enforced SLC expression had no effect on pre-B cell proliferation or differentiation. However, in the presence of conventional immunoglobulin light chains, SLC components had the capacity to induce constitutive BCR internalization, secondary immunoglobulin light-chain rearrangement, and a severe developmental arrest of immature B cells, dependent on the adaptor protein Slp65. Residual B cells in the spleen showed increased expression of surface CD5, which is a negative regulator of BCR signaling, and differentiated spontaneously into IgM+ plasma cells. Thus, the silencing of SLC genes is not essential for the limitation of pre-B cell proliferation, but is required for the prevention of constitutive activation of B cells.
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Affiliation(s)
- Pieter Fokko van Loo
- Department of Immunology, Erasmus Medical Center Rotterdam, P.O. Box 2040, NL-3000 CA Rotterdam, The Netherlands
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Abstract
The pre-B cell receptor (pre-BCR) serves as a checkpoint in B cell development. In the 2.7 angstrom structure of a human pre-BCR Fab-like fragment, consisting of an antibody heavy chain (HC) paired with the surrogate light chain, the "unique regions" of VpreB and lambda5 replace the complementarity-determining region 3 (CDR3) loop of an antibody light chain and appear to "probe" the HC CDR3, potentially influencing the selection of the antibody repertoire. Biochemical analysis indicates that the pre-BCR is impaired in its ability to recognize antigen, which, together with electron microscopic visualization of a pre-BCR dimer, suggests ligand-independent oligomerization as the likely signaling mechanism.
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Affiliation(s)
- Alexander J Bankovich
- Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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5
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Ferrari S, Zuntini R, Lougaris V, Soresina A, Sourková V, Fiorini M, Martino S, Rossi P, Pietrogrande MC, Martire B, Spadaro G, Cardinale F, Cossu F, Pierani P, Quinti I, Rossi C, Plebani A. Molecular analysis of the pre-BCR complex in a large cohort of patients affected by autosomal-recessive agammaglobulinemia. Genes Immun 2007; 8:325-33. [PMID: 17410177 DOI: 10.1038/sj.gene.6364391] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Autosomal-recessive agammaglobulinemia is a rare and heterogeneous disorder, characterized by early-onset infections, profound hypogammaglobulinemia of all immunoglobulin isotypes and absence of circulating B lymphocytes. To investigate the molecular basis of the disease, 23 patients with early-onset disease and no mutations in Bruton tyrosine kinase, the gene responsible for X-linked agammaglobulinemia, were selected and analyzed by direct sequencing of candidate genes. Two novel mutations in the mu heavy chain (muHC) gene (IGHM) were identified in three patients belonging to two unrelated families. A fourth patient carries a previously described G>A nucleotide substitution at the -1 position of an alternative splice site in IGHM; here, we demonstrate that this mutation is indeed responsible for aberrant splicing. Comparison of bone marrow cytofluorimetric profiles in two patients carrying different mutations in the IGHM gene suggests a genotype-phenotype correlation with the stage at which B-cell development is blocked. Several new single nucleotide polymorphisms (SNPs) both in the muHC and in the lambda5-like/VpreB-coding genes were identified. Two unrelated patients carry compound heterozygous variations in the VpreB1 gene that may be involved in disease ethiology.
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Affiliation(s)
- S Ferrari
- Medical Genetics Unit and CRBa, S. Orsola-Malpighi University Hospital, via Massarenti 9, 40138 Bologna, Italy.
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Thompson EC, Cobb BS, Sabbattini P, Meixlsperger S, Parelho V, Liberg D, Taylor B, Dillon N, Georgopoulos K, Jumaa H, Smale ST, Fisher AG, Merkenschlager M. Ikaros DNA-Binding Proteins as Integral Components of B Cell Developmental-Stage-Specific Regulatory Circuits. Immunity 2007; 26:335-44. [PMID: 17363301 DOI: 10.1016/j.immuni.2007.02.010] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 11/27/2006] [Accepted: 02/12/2007] [Indexed: 01/08/2023]
Abstract
Ikaros DNA-binding proteins are critical for the development of lymphocytes and other hematopoietic lineages, but it remains unclear how they cooperate with other regulators of signaling and transcription to achieve ordered gene expression during development. Here, we show that Ikaros proteins regulate the pre-BCR component lambda5 in a stage-specific manner. In pre-BI cells, Ikaros modulated lambda5 expression in competition with the transcriptional activator EBF. This required Ikaros binding to the Igll1 (lambda5) promoter and was abolished either by mutation of the Ikaros DNA-binding domain or by deletion of a single Ikaros site from the Igll1 promoter. At the transition from the pre-BI to pre-BII stage, the expression of the Ikaros family member Aiolos was upregulated and required for the efficient silencing of Igll1. Aiolos expression was controlled by pre-BCR signals via the adaptor protein SLP-65. Thus, pre-BCR signaling regulates Aiolos and the silencing of Igll1 via a developmental-stage-specific feedback loop.
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Affiliation(s)
- Elizabeth C Thompson
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College London, Du Cane Road, London W12 0NN, UK
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Meixlsperger S, Köhler F, Wossning T, Reppel M, Müschen M, Jumaa H. Conventional Light Chains Inhibit the Autonomous Signaling Capacity of the B Cell Receptor. Immunity 2007; 26:323-33. [PMID: 17331747 DOI: 10.1016/j.immuni.2007.01.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 12/14/2006] [Accepted: 01/26/2007] [Indexed: 02/06/2023]
Abstract
Signals from the B cell antigen receptor (BCR), consisting of mu heavy chain (muHC) and conventional light chain (LC), and its precursor the pre-BCR, consisting of muHC and surrogate light chain (SLC), via the adaptor protein SLP-65 regulate the development and function of B cells. Here, we compare the effect of SLC and conventional LC expression on receptor-induced Ca(2+) flux in B cells expressing an inducible form of SLP-65. We found that SLC expression strongly enhanced an autonomous ability of muHC to induce Ca(2+) flux irrespective of additional receptor crosslinking. In contrast, LC expression reduced this autonomous muHC ability and resulted in antigen-dependent Ca(2+) flux. These data indicate that autonomous ligand-independent signaling can be induced by receptor forms other than the pre-BCR. In addition, our data suggest that conventional LCs play an important role in the inhibition of autonomous receptor signaling, thereby allowing further B cell differentiation.
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Affiliation(s)
- Sonja Meixlsperger
- Institute for Biology III, Albert-Ludwigs University of Freiburg and Max Planck Institute for Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
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Vettermann C, Herrmann K, Jäck HM. Powered by pairing: The surrogate light chain amplifies immunoglobulin heavy chain signaling and pre-selects the antibody repertoire. Semin Immunol 2006; 18:44-55. [PMID: 16464608 DOI: 10.1016/j.smim.2006.01.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Selective expansion of functional pre-B cells is accomplished by the assembly of a signaling-competent pre-B cell receptor (pre-BCR) consisting of immunoglobulin mu heavy chains (muHC), surrogate light chains (SLC) and Igalpha/Igbeta. Here, we review recent data showing that muHCs, in the absence of SLC, deliver autonomous differentiation signals. However, enhanced signaling necessary for pre-B cell expansion requires cross-linking of pre-BCRs via the non-immunoglobulin tail of SLC's subunit lambda5. We also discuss how SLC's ability to modulate the strength of pre-BCR signals is controlled by a muHC's idiotype and its affinity to the chaperone BiP. In this model, BiP in concert with SLC functions as a pre-selector of the antibody repertoire.
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Affiliation(s)
- Christian Vettermann
- Division of Molecular Immunology, Department of Internal Medicine III, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, D-91054 Erlangen, Germany
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Abstract
After the demonstration that surrogate JCkappa polypeptides could covalently bind mu heavy chain and upon the characterization of the Vkappa-like component of the kappa-like pre-B cell receptor, it became evident that germline transcription is not sterile. The present review discusses the concept of the alternative usage of kappa-like pre-B cell receptors and classical pre-B cell receptors utilizing the lambda-like surrogate light chain composed of lambda5 and VpreB. We propose that both kappa-like and lambda-like pre-B cell receptors work in concert in a fail-safe mechanism to promote light chain rearrangement, heavy chain allelic exclusion and B-lymphocyte maturation.
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Affiliation(s)
- Morgan R McKeller
- Department of Immunology, The University of Texas M.D. Anderson Cancer Center, P.O. Box 301402, Unit # 902, Houston, TX 77030, USA
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Mundt C, Licence S, Maxwell G, Melchers F, Mårtensson IL. Only VpreB1, but not VpreB2, is expressed at levels which allow normal development of B cells. Int Immunol 2005; 18:163-72. [PMID: 16361315 DOI: 10.1093/intimm/dxh359] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The surrogate light chain (SLC) consists of the polypeptides lambda5 and, in the mouse, either VpreB1 or VpreB2. SLC associates with BILL-Cadherin and other glycoproteins to form the pro-B cell receptor (pro-BCR) at the pre-BI cell stage, and with the immunoglobulin mu heavy chain to form the pre-BCR at the pre-BII cell stage. The function of the pro-BCR, if any, is unknown, whereas the pre-BCR is crucial for proliferative expansion of pre-BII cells. To shed light on the functional properties of VpreB1 and VpreB2 in vivo, mice with either one or two VpreB1, or one or two VpreB2, alleles have been investigated. We show that B cell development in mice with two VpreB1 alleles is indistinguishable from that of normal mice. In contrast, mice with two VpreB2 alleles show an approximately 1.6-fold increase in pre-BI and a 35% decrease in pre-BII cell numbers, while mice with only one VpreB2 allele show a reduction in B cell development manifested in a 2-fold enrichment in pre-BI cells and a 75% reduction in pre-BII cells. However, such a gene dosage effect is not observed for VpreB1. Our results suggest that the difference between VpreB1- and VpreB2-deficient mice is due to lower VpreB2 protein expression, thus limiting the formation of pre-BCRs and thereby the number of large, cycling pre-BII cells.
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Affiliation(s)
- Cornelia Mundt
- Laboratory of Lymphocyte Signaling and Development, Babraham Institute, Babraham Research Campus, Cambridge CB2 4AT, UK
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Parker MJ, Licence S, Erlandsson L, Galler GR, Chakalova L, Osborne CS, Morgan G, Fraser P, Jumaa H, Winkler TH, Skok J, Mårtensson IL. The pre-B-cell receptor induces silencing of VpreB and lambda5 transcription. EMBO J 2005; 24:3895-905. [PMID: 16281060 PMCID: PMC1283949 DOI: 10.1038/sj.emboj.7600850] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Accepted: 10/06/2005] [Indexed: 01/17/2023] Open
Abstract
The pre-B-cell receptor (pre-BCR), composed of Ig heavy and surrogate light chain (SLC), signals pre-BII-cell proliferative expansion. We have investigated whether the pre-BCR also signals downregulation of the SLC genes (VpreB and lambda5), thereby limiting this expansion. We demonstrate that, as BM cells progress from the pre-BI to large pre-BII-cell stage, there is a shift from bi- to mono-allelic lambda5 transcription, while the second allele is silenced in small pre-BII cells. A VpreB1-promoter-driven transgene shows the same pattern, therefore suggesting that VpreB1 is similarly regulated and thereby defines the promoter as a target for transcriptional silencing. Analyses of pre-BCR-deficient mice show a temporal delay in lambda5 downregulation, thereby demonstrating that the pre-BCR is essential for monoallelic silencing at the large pre-BII-cell stage. Our data also suggest that SLP-65 is one of the signaling components important for this process. Furthermore, the VpreB1/lambda5 alleles undergo dynamic changes with respect to nuclear positioning and heterochromatin association, thereby providing a possible mechanism for their transcriptional silencing.
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Affiliation(s)
- Mathew J Parker
- Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, UK
| | - Steve Licence
- Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, UK
| | - Lena Erlandsson
- Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, UK
| | | | - Lyubomira Chakalova
- Laboratory of Chromatin and Gene Expression, The Babraham Institute, Cambridge, UK
| | - Cameron S Osborne
- Laboratory of Chromatin and Gene Expression, The Babraham Institute, Cambridge, UK
| | - Geoff Morgan
- Flow Cytometry Facility, The Babraham Institute, Cambridge, UK
| | - Peter Fraser
- Laboratory of Chromatin and Gene Expression, The Babraham Institute, Cambridge, UK
| | - Hassan Jumaa
- Institute for Biology III, Max-Planck-Institute for Immunobiology, Freiburg, Germany
| | | | - Jane Skok
- Department of Immunology and Molecular Pathology, UCL, London, UK
| | - Inga-Lill Mårtensson
- Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, UK
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Morbach H, Singh SK, Faber C, Lipsky PE, Girschick HJ. Analysis of RAG expression by peripheral blood CD5+ and CD5- B cells of patients with childhood systemic lupus erythematosus. Ann Rheum Dis 2005; 65:482-7. [PMID: 16126793 PMCID: PMC1798085 DOI: 10.1136/ard.2005.040840] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND The assembly of immunoglobulin genes during B cell development in the bone marrow is dependent on the expression of recombination activating genes (RAG) 1 and 2. Recently, RAG expression in peripheral blood IgD+ B cells outside the bone marrow has been demonstrated and is associated with the development of autoimmune diseases. OBJECTIVE To investigate RAG expression in the CD5+ or CD5- IgD+ B cell compartment in childhood systemic lupus erythematosus (SLE). METHODS Using a combination of flow cytometric cell sorting and reverse transcriptase polymerase chain reaction analysis of cDNA libraries generated from individual cells, the expression of RAG, VpreB, and CD154 mRNA by individual peripheral blood B cells of three paediatric SLE patients was examined in detail. RESULTS While only one patient had a significantly increased frequency of RAG+ B cells in the CD5- B cell population, all patients showed higher frequencies of RAG+ B cells in the CD5+IgD+ B cell population. The frequency of RAG+ IgD+CD5+/- B cells was reduced during intravenous cyclophosphamide treatment. In healthy age matched children, RAG expressing IgD+ B cells were hardly detectable. Coexpression of RAG and VpreB or CD154 mRNA could only be found in SLE B cells. CONCLUSIONS RAG expression in peripheral blood B cells of SLE patients is particularly increased in the IgD+CD5+ B cell population. CD5+ and CD5- B cells in SLE have the potential to undergo receptor revision leading to the generation of high affinity pathogenic autoantibodies.
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Affiliation(s)
- H Morbach
- Section of Paediatric Rheumatology, Children's Hospital, University of Würzburg, Josef-Schneider-Str 2, 97080 Würzburg, Germany
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Minaee S, Farmer D, Georgiou A, Sabbattini P, Webster Z, Chow CM, Dillon N. Mapping and functional analysis of regulatory sequences in the mouse λ5-VpreB1 domain. Mol Immunol 2005; 42:1283-92. [PMID: 15950724 DOI: 10.1016/j.molimm.2005.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Indexed: 11/30/2022]
Abstract
The lambda5 and VpreB genes encode the components of the surrogate light-chain which forms part of the pre-B cell receptor and plays a key role in B cell development. In the mouse, the lambda5 and VpreB1 genes are closely linked and are co-regulated by a multi-component locus control region. To identify the sequences that regulate lambda5 and VpreB1 expression during B cell development, we have comprehensively mapped the DNaseI hypersensitive sites (HS) in the lambda5-VpreB1 functional domain. The active domain contains 12 HS that are distributed at high density across the 18.3 kb region that forms the lambda5 and VpreB1 functional unit. Analysis of a reporter gene driven by the VpreB1 promoter in transgenic mice identified a novel enhancer associated with two HS located upstream of lambda5. The lambda5-VpreB1 locus was also found to be closely linked to the ubiquitously expressed Topoisomerase-3beta (Topo3beta) gene. The VpreB1 and Topo3beta genes have entirely different expression patterns despite the fact that the two promoters are separated by a distance of only 1.5 kb.
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Affiliation(s)
- Sophia Minaee
- Gene regulation and Chromatin Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London W12 ONN, UK
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14
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Guloglu FB, Bajor E, Smith BP, Roman CAJ. The Unique Region of Surrogate Light Chain Component λ5 Is a Heavy Chain-Specific Regulator of Precursor B Cell Receptor Signaling. J Immunol 2005; 175:358-66. [PMID: 15972669 DOI: 10.4049/jimmunol.175.1.358] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Signals transduced by precursor-BCRs (pre-BCRs) composed of Ig mu heavy chains (HCs) and the surrogate L chain components lambda5 and VpreB are critical for B cell development. A conserved unique region (UR) of lambda5 was shown to activate pre-BCR complexes in transformed cells and to engage putative ligands, but its contribution to pre-B cell development is not known. It is also not clear why the lambda-like sequences in lambda5 are used to select HCs that will associate mainly with kappa L chains. In this study, we show that, in transformed and primary mouse B cell progenitors, receptors containing full-length HCs and lacking the lambda5UR were expressed at higher surface levels, but exhibited reduced activity compared with normal pre-BCRs in supporting developmental changes that accompany the progenitor to pre-B cell transition in primary cell culture systems and in the bone marrow in vivo. In contrast, deletion of the lambda5UR did not change net signaling output by the Dmu-pre-BCR, a developmentally defective receptor that exhibited impaired activity in the primary cell culture system. Moreover, the lambda-like sequences in lambda5 were more accommodating than kappa in supporting surface expression and signaling by the different HCs. These results show that the lambda5UR is important, although not essential, for surrogate L chain-dependent receptor signaling in primary cells, and furthermore may help allow discrimination of signaling competency between normal and Dmu-pre-BCRs. That the lambda-like portion of lambda5 in the absence of the UR was nondiscriminatory suggests that the lambda5UR focuses pre-BCR-dependent selection on the HC V region.
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Affiliation(s)
- F Betul Guloglu
- Department of Microbiology and Immunology, School of Graduate Studies, State University of New York, Downstate Medical Center at Brooklyn, Brooklyn, NY 11203, USA
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15
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Pan Y, Li GD, Liu WP. [Advances of lymphoblastic lymphoma and its molecular genetics]. Zhonghua Bing Li Xue Za Zhi 2005; 34:236-9. [PMID: 16091181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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16
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Abstract
The lambda5 and VpreB genes encode the components of the surrogate light-chain, which forms part of the pre-B cell receptor. In mouse, the lambda5 and VpreB1 genes of mouse are closely linked and coordinately regulated by a locus control region (LCR). Activation of the genes in pro-B cells depends on the combined effects of early B cell factor (EBF) and the E2A factors E12 and E47. Silencing of lambda5 expression in mature B cells occurs through the action of Ikaros on the gene promoter where it may compete for binding of EBF and initiate the formation of a silent chromatin structure.
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Affiliation(s)
- Pierangela Sabbattini
- Gene Regulation and Chromatin Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London W12 ONN, UK.
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17
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Szutorisz H, Canzonetta C, Georgiou A, Chow CM, Tora L, Dillon N. Formation of an active tissue-specific chromatin domain initiated by epigenetic marking at the embryonic stem cell stage. Mol Cell Biol 2005; 25:1804-20. [PMID: 15713636 PMCID: PMC549375 DOI: 10.1128/mcb.25.5.1804-1820.2005] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The differentiation potential of stem cells is determined by the ability of these cells to establish and maintain developmentally regulated gene expression programs that are specific to different lineages. Although transcriptionally potentiated epigenetic states of genes have been described for haematopoietic progenitors, the developmental stage at which the formation of lineage-specific gene expression domains is initiated remains unclear. In this study, we show that an intergenic cis-acting element in the mouse lambda5-VpreB1 locus is marked by histone H3 acetylation and histone H3 lysine 4 methylation at a discrete site in embryonic stem (ES) cells. The epigenetic modifications spread from this site toward the VpreB1 and lambda5 genes at later stages of B-cell development, and a large, active chromatin domain is established in pre-B cells when the genes are fully expressed. In early B-cell progenitors, the binding of haematopoietic factor PU.1 coincides with the expansion of the marked region, and the region becomes a center for the recruitment of general transcription factors and RNA polymerase II. In pre-B cells, E2A also binds to the locus, and general transcription factors are distributed across the active domain, including the gene promoters and the intergenic region. These results suggest that localized epigenetic marking is important for establishing the transcriptional competence of the lambda5 and VpreB1 genes as early as the pluripotent ES cell stage.
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MESH Headings
- Acetylation
- Animals
- B-Lymphocytes/cytology
- B-Lymphocytes/physiology
- Basic Helix-Loop-Helix Transcription Factors
- Cell Differentiation/genetics
- Cell Differentiation/physiology
- Cells, Cultured
- Chromatin/genetics
- Chromatin/metabolism
- Chromatin Immunoprecipitation
- DNA Topoisomerases, Type I/genetics
- DNA, Intergenic/genetics
- DNA, Intergenic/metabolism
- DNA-Binding Proteins/metabolism
- Embryo, Mammalian/cytology
- Epigenesis, Genetic/physiology
- Gene Expression Regulation, Developmental/physiology
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/physiology
- Histones/metabolism
- Immunoglobulin Light Chains
- Immunoglobulin Light Chains, Surrogate
- Isoenzymes/genetics
- Membrane Glycoproteins/genetics
- Methylation
- Mice
- Promoter Regions, Genetic/genetics
- Proto-Oncogene Proteins/metabolism
- Trans-Activators/metabolism
- Transcription Factors/metabolism
- Transcription Initiation Site/physiology
- Transcription, Genetic
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Affiliation(s)
- Henrietta Szutorisz
- Gene Regulation and Chromatin Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Rd., London W12 0NN, United Kingdom
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Cannon JP, Haire RN, Pancer Z, Mueller MG, Skapura D, Cooper MD, Litman GW. Variable domains and a VpreB-like molecule are present in a jawless vertebrate. Immunogenetics 2005; 56:924-9. [PMID: 15650874 PMCID: PMC3689217 DOI: 10.1007/s00251-004-0766-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Revised: 11/29/2004] [Indexed: 10/25/2022]
Abstract
Immunoglobulins (Igs) and T cell antigen receptors (TCRs) that undergo somatic diversification have not been identified in the two extant orders of jawless vertebrates, which occupy essential positions in terms of understanding the evolution of the emergence of adaptive immunity. Using a single motif-dependent PCR-based approach coupled with a vector that allows selection of cDNAs encoding secretion signal sequences, four different genes encoding Ig V-type domains were identified in the sea lamprey (Petromyzon marinus). One of the predicted proteins encoded by these genes shares structural characteristics with mammalian VpreB molecules, including the absence of a recognizable transmembrane region, a relatively high proportion of charged amino acids in its C-terminal tail and distinctive features of its secretion signal peptide. This is the first indication of a molecule related to the B cell receptor (BCR) complex in a species that diverged prior to the jawed vertebrates in which RAG-mediated adaptive immunity is first encountered.
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Affiliation(s)
- John P. Cannon
- Department of Molecular Genetics, All Children's Hospital, 801 Sixth Street South, St. Petersburg, FL, 33701, USA, Tel.: +1-727-553-3601, Fax: +1-727-553-3610; H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL, 33612, USA, Department of Pediatrics, USF/ACH Children's Research, Institute, University of South Florida College of Medicine, 830 First Street South, St. Petersburg, FL, 33701, USA
| | - Robert N. Haire
- Department of Pediatrics, USF/ACH Children's Research, Institute, University of South Florida College of Medicine, 830 First Street South, St. Petersburg, FL, 33701, USA
| | - Zeev Pancer
- Howard Hughes Medical Institute, University of Alabama at Birmingham, 378 Wallace Tumor Institute, Birmingham, AL, 35294, USA
| | - M. Gail Mueller
- Department of Pediatrics, USF/ACH Children's Research, Institute, University of South Florida College of Medicine, 830 First Street South, St. Petersburg, FL, 33701, USA
| | - Diana Skapura
- Department of Pediatrics, USF/ACH Children's Research, Institute, University of South Florida College of Medicine, 830 First Street South, St. Petersburg, FL, 33701, USA
| | - Max D. Cooper
- Howard Hughes Medical Institute, University of Alabama at Birmingham, 378 Wallace Tumor Institute, Birmingham, AL, 35294, USA
| | - Gary W. Litman
- Department of Molecular Genetics, All Children's Hospital, 801 Sixth Street South, St. Petersburg, FL, 33701, USA, Tel.: +1-727-553-3601, Fax: +1-727-553-3610; H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL, 33612, USA; Department of Pediatrics, USF/ACH Children's Research, Institute, University of South Florida College of Medicine, 830 First Street South, St. Petersburg, FL, 33701, USA
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Kiyokawa N, Sekino T, Matsui T, Takenouchi H, Mimori K, Tang WR, Matsui J, Taguchi T, Katagiri YU, Okita H, Matsuo Y, Karasuyama H, Fujimoto J. Diagnostic importance of CD179a/b as markers of precursor B-cell lymphoblastic lymphoma. Mod Pathol 2004; 17:423-9. [PMID: 14976526 DOI: 10.1038/modpathol.3800079] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Surrogate light chains consisting of VpreB (CD179a) and lambda5 (CD179b) are expressed in precursor B cells lacking a complete form of immunoglobulin and are thought to act as substitutes for conventional light chains. Upon differentiation to immature and mature B cells, CD179a/b disappear and are replaced with conventional light chains. Thus, these molecules may be useful as essential markers of precursor B cells. To examine the expression of the surrogate light-chain components CD179a and CD179b in precursor B-cell lymphoblastic lymphoma, we analyzed tissue sections using immunohistochemistry techniques. Among a number of monoclonal antibodies for the surrogate light chains, VpreB8 and SL11 were found to detect CD179a and CD179b, respectively, in acetone-fixed fresh frozen sections. Moreover, we also observed VpreB8 staining in formalin-fixed, paraffin-embedded sections. Using these antibodies, we found that CD179a/b were specifically expressed in precursor B-cell lymphoblastic lymphomas, but not in mature B-cell lymphomas in childhood. Furthermore, other pediatric tumors that must be included in a differential diagnosis of precursor B-cell lymphoblastic lymphoma, including precursor T-cell lymphoblastic lymphoma, extramedullary myeloid tumors, and Ewing sarcoma, were also negative for both CD179a and CD179b. Our data indicate that CD179a and CD179b may be important markers for the immunophenotypic diagnosis of precursor B-cell lymphoblastic lymphomas.
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Affiliation(s)
- Nobutaka Kiyokawa
- Department of Developmental Biology, National Research Institute for Child Health and Development, Japan.
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20
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Martin DA, Bradl H, Collins TJ, Roth E, Jäck HM, Wu GE. Selection of Ig mu heavy chains by complementarity-determining region 3 length and amino acid composition. J Immunol 2004; 171:4663-71. [PMID: 14568941 DOI: 10.4049/jimmunol.171.9.4663] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although it is generally accepted that Ig heavy chains (HC) are selected at the pre-B cell receptor (pre-BCR) checkpoint, the characteristics of a functional HC and the role of pre-BCR assembly in their selection have remained elusive. We determined the characteristics of HCs that successfully passed the pre-BCR checkpoint by examining transcripts harboring V(H)81X and J(H)4 gene segments from J(H)(+/-) and lambda5(-/-)mice. V(H)81X-J(H)4-HC transcripts isolated from cells before or in the absence of pre-BCR assembly had no distinguishing complementarity-determining region 3 traits. In contrast, transcripts isolated subsequent to passage through the pre-BCR checkpoint had distinctive complementarity-determining regions 3 of nine amino acids in length (49%) and a histidine at position 1 (73%). Hence, our data define specific structural requirements for a functional HC, which is instrumental in shaping the diverse B cell repertoire.
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MESH Headings
- Amino Acids/analysis
- Amino Acids/genetics
- Animals
- B-Lymphocyte Subsets/cytology
- B-Lymphocyte Subsets/immunology
- B-Lymphocyte Subsets/metabolism
- Bone Marrow Cells/cytology
- Bone Marrow Cells/immunology
- Bone Marrow Cells/metabolism
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Membrane/genetics
- Cell Membrane/immunology
- Cell Membrane/metabolism
- Complementarity Determining Regions/biosynthesis
- Complementarity Determining Regions/genetics
- Complementarity Determining Regions/physiology
- Gene Rearrangement, B-Lymphocyte, Heavy Chain
- Histidine/analysis
- Histidine/genetics
- Immunoglobulin Heavy Chains/biosynthesis
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Heavy Chains/physiology
- Immunoglobulin Light Chains
- Immunoglobulin Light Chains, Surrogate
- Immunoglobulin mu-Chains/biosynthesis
- Immunoglobulin mu-Chains/genetics
- Immunoglobulin mu-Chains/physiology
- Membrane Glycoproteins/deficiency
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Models, Immunological
- Models, Molecular
- Peptide Fragments/biosynthesis
- Peptide Fragments/genetics
- Peptide Fragments/physiology
- Protein Processing, Post-Translational/genetics
- Protein Processing, Post-Translational/immunology
- Protein Structure, Tertiary
- Spleen/cytology
- Spleen/immunology
- Spleen/metabolism
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Affiliation(s)
- Denise A Martin
- Department of Immunology, University of Toronto, and Ontario Cancer Institute, Toronto, Canada
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22
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Abstract
In mammals that use gut-associated lymphoid tissues for expansion and somatic diversification of the B cell repertoire, B lymphopoiesis occurs early in ontogeny and does not appear to continue throughout life. In these species, including sheep, rabbit, and cattle, little is known about the pathway of B cell development and the time at which B lymphopoiesis wanes. We examined rabbit bone marrow by immunofluorescence with anti-CD79a and anti-mu and identified both proB and preB cells. The proB cells represent the vast majority of B-lineage cells in the bone marrow at birth and by incorporation of 5-bromo-2'-deoxyuridine, they appear to be a dynamic population. PreB cells reach maximum levels in the bone marrow at 3 wk of age, and B cells begin to accumulate at 7 wk of age. We cloned two VpreB and one lambda5 gene and demonstrated that they are expressed within B-lineage cells in bone marrow. VpreB and lambda5 coimmunoprecipitated with the mu-chain in lysates of 293T cells transfected with VpreB, lambda5, and mu, indicating that VpreB, lambda5, and mu-chains associate in a preB cell receptor-like complex. By 16 wk of age, essentially no proB or preB cells are found in bone marrow and by PCR amplification, B cell recombination excision circles were reduced 200-fold. By 18 mo of age, B cell recombination excision circles were reduced 500- to 1000-fold. We suggest that B cell development in the rabbit occurs primarily through the classical, or ordered, pathway and show that B lymphopoiesis is reduced over 99% by 16 wk of age.
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Affiliation(s)
- Paul J Jasper
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL 60153, USA
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23
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Bradl H, Wittmann J, Milius D, Vettermann C, Jäck HM. Interaction of murine precursor B cell receptor with stroma cells is controlled by the unique tail of lambda 5 and stroma cell-associated heparan sulfate. J Immunol 2003; 171:2338-48. [PMID: 12928380 DOI: 10.4049/jimmunol.171.5.2338] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Efficient clonal expansion of early precursor B (pre-B) cells requires signals delivered by an Ig-like integral membrane complex, the so-called pre-B cell receptor (pre-BCR). A pre-BCR consists of two membrane micro H chains, two covalently associated surrogate L chains, and the heterodimeric signaling transducer Igalphabeta. In contrast to a conventional Ig L chain, the surrogate L chain is a heterodimer composed of the invariant polypeptides VpreB and lambda5. Although it is still unclear how pre-BCR signals are initiated, two recent findings support a ligand-dependent initiation of pre-BCR signals: 1) a pre-BCR/galectin-1 interaction is required to induce phosphorylation of Igalphabeta in a human precursor B line, and 2) soluble murine as well as human pre-BCR molecules bind to stroma and other adherent cells. In this study, we show that efficient binding of a soluble murine pre-BCR to stroma cells requires the non-Ig-like unique tail of lambda5. Surprisingly however, a murine pre-BCR, in contrast to its human counterpart, does not interact with galectin-1, as revealed by lactose blocking, RNA interference, and immunoprecipitation assays. Finally, the binding of a murine pre-BCR to stroma cells can be blocked either with heparin or by pretreatment of stroma cells with heparitinase or a sulfation inhibitor. Hence, efficient binding of a murine pre-BCR to stroma cells requires the unique tail of lambda5 and stroma cell-associated heparan sulfate. These findings not only identified heparan sulfate as potential pre-BCR ligands, but will also facilitate the development of appropriate animal models to determine whether a pre-BCR/heparan sulfate interaction is involved in early B cell maturation.
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MESH Headings
- 3T3 Cells
- Amino Acid Sequence
- Animals
- Baculoviridae/genetics
- Binding Sites, Antibody/drug effects
- Binding Sites, Antibody/genetics
- Cell Line
- Galectin 1/metabolism
- Genetic Vectors
- HeLa Cells
- Hematopoietic Stem Cells/immunology
- Hematopoietic Stem Cells/metabolism
- Heparin/pharmacology
- Heparitin Sulfate/metabolism
- Heparitin Sulfate/physiology
- Humans
- Immunoglobulin Constant Regions/metabolism
- Immunoglobulin Light Chains
- Immunoglobulin Light Chains, Surrogate
- Immunoglobulin Variable Region/metabolism
- Immunoglobulin Variable Region/physiology
- Immunoglobulin lambda-Chains/metabolism
- Immunoglobulin lambda-Chains/physiology
- Ligands
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Membrane Glycoproteins/physiology
- Mice
- Molecular Sequence Data
- Protein Structure, Tertiary/genetics
- Receptors, Antigen, B-Cell/antagonists & inhibitors
- Receptors, Antigen, B-Cell/deficiency
- Receptors, Antigen, B-Cell/metabolism
- Solubility
- Spodoptera
- Stromal Cells/drug effects
- Stromal Cells/immunology
- Stromal Cells/metabolism
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Affiliation(s)
- Harald Bradl
- Division of Molecular Immunology, Department of Internal Medicine III, Nikolaus-Fiebiger-Center, University of Erlangen-Nürnberg, Glückstrasse 6, D-91054 Erlangen, Germany
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24
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Abstract
In adult mice, the VpreB genes are expressed in bone marrow progenitor (pro-) and precursor (pre-) B cells. As part of the pre-B cell receptor, the proteins are crucial for the proliferation of these cells and consequently normal B lymphocyte development. Using cell lines, we identified a lineage- and developmental-stage-specific VpreB1 enhancer. Here, we analyze its specificity in vivo by generating transgenic mice in which expression of a reporter gene (human CD122) is regulated by the VpreB1 enhancer in the context of its own promoter. All transgenic lines expressed the reporter gene in the bone marrow in a copy number-independent manner, whereas expression levels were integration site-dependent. While the enhancer is not tissue specific, within the B cell lineage the expression pattern of human CD122 mimicked that of endogenous VpreB1. Thus, low levels were detected in pro-B cells, high levels in pre-BI and slightly lower levels in pre-BII cells; no expression was detected in immature/mature B cells. Furthermore, when in vitro cultured transgenic pre-B cells differentiated into immature B cells there was concomitant down-regulation of human CD122 and endogenous VpreB1. Thus the VpreB1 enhancer is sufficient to ensure developmental stage-specific expression of a reporter gene in B lymphocytes in vivo.
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MESH Headings
- 5' Flanking Region
- Animals
- B-Lymphocytes/immunology
- Biomarkers/analysis
- Cells, Cultured
- Enhancer Elements, Genetic
- Gene Dosage
- Gene Expression Regulation, Developmental
- Genes, Immunoglobulin
- Genes, Reporter
- Hematopoietic Stem Cells/metabolism
- Humans
- Immunoglobulin Light Chains
- Immunoglobulin Light Chains, Surrogate
- Immunoglobulin Variable Region/genetics
- Membrane Glycoproteins/genetics
- Mice
- Mice, Transgenic
- RNA, Messenger/biosynthesis
- Receptors, Interleukin-2/biosynthesis
- Receptors, Interleukin-2/genetics
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Affiliation(s)
- Steve Licence
- Developmental Immunology, The Babraham Institute, Cambridge, GB
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25
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Abstract
The pre-B cell receptor (pre-BCR) is composed of the immunoglobulin (Ig) heavy (microH) chain and the surrogate light chain encoded by VpreB and lambda5. The pre-BCR has been implicated in precursor B cell proliferation, differentiation and IgH chain allelic exclusion. B cell development in mice lacking the transmembrane form of microH chain is blocked at the precursor B cell stage: the cells cannot proliferate or differentiate further and the IgH locus is allelically included. In mice lacking lambda5, the precursor B cells, although unable to proliferate, can nonetheless differentiate, whereas the IgH locus is allelically excluded. It was, therefore, postulated that microH chain together with VpreB could form a pre-BCR-like receptor that would allow IgH allelic exclusion but not proliferation. In mice lacking both VpreB genes, precursor B cells do not proliferate but are able to differentiate. Surprisingly, the IgH locus is allelically excluded. This suggests that microH chains find other partner proteins to signal allelic exclusion.
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26
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Abstract
Only a subpopulation of relatively large pre-B cells express pre-B cell receptors (preBCR) that can be seen with very sensitive immunofluorescence methods. Inefficient assembly of the multicomponent preBCR coupled with their ligand-induced endocytosis may account for the remarkably low in vivo levels of preBCR expression. Signaling initiated via the preBCR promotes cellular proliferation and RAG-1 and RAG-2 downregulation to interrupt the immunoglobulin V(D)J gene rearrangement process. Silencing of the surrogate light chain genes, VpreB and lambda5, then terminates preBCR expression to permit cell cycle exit, recombinase gene upregulation, and VJ(L) rearrangement by small pre-B cells destined to become B cells.
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Affiliation(s)
- Peter D Burrows
- Division of Developmental and Clinical Immunology, University of Alabama at Birmingham, WTI 378, 1824 6th Avenue South, Birmingham, AL 35294-3300, USA
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27
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Shimizu T, Mundt C, Licence S, Melchers F, Mårtensson IL. VpreB1/VpreB2/lambda 5 triple-deficient mice show impaired B cell development but functional allelic exclusion of the IgH locus. J Immunol 2002; 168:6286-93. [PMID: 12055243 DOI: 10.4049/jimmunol.168.12.6286] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
At the precursor B cell stage during bone marrow B cell development, Ig muH chain associates with surrogate L (SL) chain, which is encoded by the three genes VpreB1, VpreB2, and lambda 5, to form the pre-B cell receptor (pre-BCR). Surface expression of the pre-BCR is believed to signal both proliferation and allelic exclusion of the IgH locus. Mice which lack either VpreB1/VpreB2 or lambda 5 show a lack of precursor B cell expansion but normal IgH allelic exclusion. This would suggest that one of either lambda 5 or VpreB can make a pre-BCR-like complex which is still able to signal allelic exclusion but not proliferation. To investigate this, we established mice lacking all components of the SL chain. These mice showed severely impaired B cell development which was similar to that previously found in mice lacking either lambda 5 or VpreB1/VpreB2. Surprisingly, the IgH locus was still allelically excluded and thus the SL chain appears not to be involved in allelic exclusion.
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28
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Abstract
The development of mature B lymphoid cells involves a highly orchestrated regulation of stage- and lineage-specific genes. In this study, we report an analysis of the human surrogate L chain VpreB promoter. The promoter has an overall homology of 56% to the mouse counterpart and displays a preB cell-restricted activity in transient transfections in cell lines. The promoter harbors three independent binding sites for early B cell factor (EBF) as defined by EMSA and supershift experiments. These sites were important for the full function of the promoter in a preB cell line, and chromatin immunoprecipitation experiments indicate that EBF interacts with the promoter in vivo. In addition to this, ectopic expression of EBF induces the activity of a reporter gene under control of the VpreB promoter in epithelioid HeLa cells, an effect augmented by coexpression of the basic-helix-loop helix transcription factor E47. The ability to interact directly with E47 was shared by the promoters controlling the human mb-1 and B29 genes. These data indicate that the human VpreB promoter is a direct target for activation by EBF and E47 and that functional collaboration between these proteins may be of great importance in human B cell development.
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Affiliation(s)
- Ramiro Gisler
- Laboratory for Cellular Differentiation, Department for Stem Cell Biology, BMC B12, 22184 Lund, Sweden.
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29
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Girschick HJ, Grammer AC, Nanki T, Vazquez E, Lipsky PE. Expression of recombination activating genes 1 and 2 in peripheral B cells of patients with systemic lupus erythematosus. Arthritis Rheum 2002; 46:1255-63. [PMID: 12115231 DOI: 10.1002/art.10264] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To analyze immunoregulatory abnormalities in patients with systemic lupus erythematosus (SLE) by assessing the expression of messenger RNA (mRNA) for types 1 and 2 recombination activating genes (RAG) in the peripheral blood of patients with active SLE. METHODS We examined B cell populations and also individual B cells from patients with SLE for the expression of RAG mRNA. RESULTS Analysis of bulk mRNA indicated that RAG1 and RAG2 mRNA were found routinely in peripheral B cells of patients with active SLE, but not in healthy subjects. When assessed on a single-cell basis, there was a 3-fold increase in the frequency of RAG1- and RAG2-expressing B cells in SLE patients compared with healthy subjects. Notably, B cells expressing both RAG1 and RAG2 mRNA expressed only IgD mRNA, but not IgG mRNA. Fifty percent of RAG-expressing B cells also expressed VpreB mRNA, whereas all expressed CD154 mRNA. Phenotypic analysis indicated that RAG-expressing B cells were activated, mature B cells. CONCLUSION These results indicate that RAG expression is up-regulated in peripheral IgD+ and VpreB+ B cells of patients with active SLE. These cells may contribute to the immunoregulatory abnormalities in patients with SLE.
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Wang YH, Stephan RP, Scheffold A, Kunkel D, Karasuyama H, Radbruch A, Cooper MD. Differential surrogate light chain expression governs B-cell differentiation. Blood 2002; 99:2459-67. [PMID: 11895780 DOI: 10.1182/blood.v99.7.2459] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Surrogate light chain expression during B lineage differentiation was examined by using indicator fluorochrome-filled liposomes in an enhanced immunofluorescence assay. Pro-B cells bearing surrogate light chain components were found in mice, but not in humans. A limited subpopulation of relatively large pre-B cells in both species expressed pre-B cell receptors. These cells had reduced expression of the recombinase activating genes, RAG-1 and RAG-2. Their receptor-negative pre-B cell progeny were relatively small, expressed RAG-1 and RAG-2, and exhibited selective down-regulation of VpreB and lambda5 expression. Comparative analysis of the 2 pre-B cell subpopulations indicated that loss of the pre-B cell receptors from surrogate light chain gene silencing was linked with exit from the cell cycle and light chain gene rearrangement to achieve B-cell differentiation.
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Affiliation(s)
- Yui-Hsi Wang
- Department of Medicine, Division of Developmental and Clinical Immunology, University of Alabama at Birmingham, 1824 6th Avenue S, Birmingham, AL 35294-3300, USA
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31
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Abstract
Signals initiated by the precursor B cell receptor (pre-BCR) are critical for B cell progenitors to mature into precursor B cells. The pre-BCR consists of a homodimer of microH chains, the covalently associated surrogate L (SL) chain composed of VpreB and lambda5, and the transmembrane signal molecules Ig(alpha) and Igbeta. One way to explain how maturation signals are initiated in late progenitor B cells is that the pre-BCR is transported to the cell surface and interacts from there with a ligand on stroma cells. To address this hypothesis, we first produced soluble Fab-like pre-BCR and BCR fragments, as well as SL chain, in baculovirus-infected insect cells. Flow cytometry revealed that, in contrast to Fab-like BCR fragments, the soluble pre-BCR binds to the surface of stroma and several other adherent cell lines, but not to B and T lymphoid suspension cells. The specific binding of the soluble pre-BCR to stroma cells is saturable, sensitive to trypsin digestion, and not dependent on bivalent cations. The binding of pre-BCR seems to be independent of the H chain of IgM (microH chain), because SL chain alone was able to interact with stroma cells. Finally, soluble pre-BCR specifically precipitated a 135-kDa protein from ST2 cells. These findings not only demonstrate for the first time the capacity of a pre-BCR to specifically bind to a structure on the surface of adherent cells, but also suggest that the pre-BCR interacts via its SL chain with a putative ligand on stroma cells.
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Affiliation(s)
- H Bradl
- Division of Molecular Immunology, Department of Internal Medicine III, Nikolaus-Fiebiger Center, University of Erlangen-Nürnberg, Erlangen, Germany
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32
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Stephan RP, Elgavish E, Karasuyama H, Kubagawa H, Cooper MD. Analysis of VpreB expression during B lineage differentiation in lambda5-deficient mice. J Immunol 2001; 167:3734-9. [PMID: 11564789 DOI: 10.4049/jimmunol.167.7.3734] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The VpreB/lambda5 surrogate L chain complex is an essential component of the pre-B cell receptor, the expression of which serves as an important checkpoint in B cell development. Surrogate L chains also may serve as components of murine pro-B cell receptors whose function is unknown. We have produced two new mAbs, R3 and R5, that recognize a different VpreB epitope than the one recognized by the previously described VP245 anti-mouse VpreB Ab. These Abs were used to confirm the expression of surrogate L chains on wild-type pro-B and pre-B cell lines. Although undetectable on the cell surface, VpreB was found to be normally expressed within B lineage cells of lambda5-deficient mice. Nevertheless, VpreB expression was extinguished at the B cell stage of differentiation in these mice. The normal pattern of VpreB expression in lambda5-deficient mice excludes an essential role for pro-B and pre-B cell receptors in VpreB regulation.
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Affiliation(s)
- R P Stephan
- Division of Developmental and Clinical Immunology, University of Alabama, 18214 Sixth Avenue South, Birmingham, AL 35294, USA
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33
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Fang T, Smith BP, Roman CA. Conventional and surrogate light chains differentially regulate Ig mu and Dmu heavy chain maturation and surface expression. J Immunol 2001; 167:3846-57. [PMID: 11564802 DOI: 10.4049/jimmunol.167.7.3846] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Positive selection of precursor (pre-) B cells by Ig membrane mu H chains (mum HC) and counterselection mediated by the truncated HC Dmu depend on the ability of each HC to form a pre-B cell receptor (pre-BCR) signaling complex with the surrogate L chain (SLC) components lambda5 and Vpre-B. To better understand how pre-BCR signaling output is determined by its Ig components and the SLC, we investigated the regulation of pre-BCR surface expression and HC secretory maturation in a new nonlymphoid system. We took this approach as a means to distinguish B-lineage-specific effects from pre-BCR-intrinsic properties that may influence these aspects of pre-BCR homeostasis necessary for signaling. As in pre-B cells, the SLC in nonlymphoid cells supported only a limited degree of mum HC maturation and low pre-BCR surface expression levels compared with conventional LCs, indicating that this was due to an intrinsic property of the SLC. We identified the non-Ig region of lambda5 as harboring the restrictive activity responsible for this phenotype. This property of lambda5 was also evident with Dmu, but the overall SLC- and L chain-dependent requirements for Dmu maturation and surface expression were markedly different from those for mum. Surprisingly, Dmu was modified in an unusual manner that was only dependent on Vpre-B. These results establish a novel function of lambda5 in limiting surface pre-BCR levels and reveal biochemical properties of Ig molecules that may underlie the diverse consequences of pre-BCR signaling in vivo by different HCs.
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Affiliation(s)
- T Fang
- Department of Microbiology and Immunology and Morse Institute for Molecular Genetics, State University of New York-Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
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34
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Meffre E, Chiorazzi M, Nussenzweig MC. Circulating human B cells that express surrogate light chains display a unique antibody repertoire. J Immunol 2001; 167:2151-6. [PMID: 11489999 DOI: 10.4049/jimmunol.167.4.2151] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Circulating human B cells that coexpress V-preB and conventional L chains (V-preB+L+ B cells) are a recently described subset of B cells that express Abs with features of self-reactivity. Initial analysis of V-preB+L+ B cells was limited to Ig-kappa and to the small, underused VH5 family. To determine whether Abs commonly expressed by V-preB+L+ B cells show similar features, we analyzed Ig H chains from three highly expressed VH families, VH1, VH3, and VH4, and Ig-lambda. We find that VH1 and VH3 Abs expressed by V-preB+L+ B cells resemble VH5 in that they display increased JH6 use, long CDR3s, and an increased frequency of D-D fusions. Abs in all three of these VH families also show skewed D reading frame use resulting in predominance of hydrophobic amino acids, which are counterselected in conventional B cells. Like Ig-kappa genes, the Ig-lambda genes in V-preB+L+ B cells show long CDR3s, but they differ from Ig-kappa genes in that they display no evidence of receptor editing. We conclude that a large number of H and L chain Abs expressed by V-preB+L+ B cells display features associated with self-reactive Abs.
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Affiliation(s)
- E Meffre
- Laboratory of Molecular Immunology, and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10021, USA
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35
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Abstract
Nineteen different mu heavy-chains, seven of them not capable of forming a pre B cell receptor were expressed in Drosophila melanogaster Schneider cells together with either VpreB1, VpreB2, lambda5, or the complete surrogate light-chain to study their interactions in the formation of the pre B cell receptor. The lambda5 protein alone was unable to bind properly to any of the mu heavy-chains, while the VpreB proteins alone formed complexes with five of the mu heavy-chains. All mu heavy-chains incapable of forming a pre B cell receptor with surrogate light-chain were also incapable of complex formation with VpreB. The possible role of the VpreB/mu heavy-chain in allelic exclusion of the heavy-chain locus during B cell development is discussed.
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Affiliation(s)
- T Seidl
- Basel Institute for Immunology, Basel, Switzerland
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36
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Nonoyama S. [Surrogate light chain deficiency]. Ryoikibetsu Shokogun Shirizu 2001:104-5. [PMID: 11212654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- S Nonoyama
- Department of Pediatrics, School of Medicine, Tokyo Medical and Dental University
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37
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Kanegane H, Miyawaki T. [Autosomal recessive agammaglobulinemia]. Ryoikibetsu Shokogun Shirizu 2001:63-5. [PMID: 11212824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- H Kanegane
- Department of Pediatrics, Faculty of Medicine, Toyama Medical and Pharmaceutical University
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38
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Abstract
The pre-B cell receptor consists of immunoglobulin (Ig) mu heavy chains and surrogate light chain, i.e., the VpreB and lambda5 proteins. To analyze the role of the two VpreB proteins, mice lacking the VpreB1 and VpreB2 genes were generated. VpreB1(-/-) VpreB2(-/-) mice were impaired in their B cell development at the transition from pre-BI to large pre-BII cells. Pre-BII cells did not expand by proliferation, consequently 40-fold less small pre-BII and immature B cells were found in bone marrow, and the generation of immature and mature conventional B cells in spleen appeared reduced. In addition, only low numbers of B-1a cells were detected in the peritoneum. Surprisingly, Ig heavy chain allelic exclusion was still active, apparently ruling out a signaling role of a VpreB1/VpreB2-containing receptor in this process.
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Affiliation(s)
- Cornelia Mundt
- Developmental Immunology, The Babraham Institute, Cambridge CB2 4AT, United Kingdom
| | - Steve Licence
- Developmental Immunology, The Babraham Institute, Cambridge CB2 4AT, United Kingdom
| | | | | | - Inga-Lill Mårtensson
- Developmental Immunology, The Babraham Institute, Cambridge CB2 4AT, United Kingdom
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39
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Hess J, Werner A, Wirth T, Melchers F, Jäck HM, Winkler TH. Induction of pre-B cell proliferation after de novo synthesis of the pre-B cell receptor. Proc Natl Acad Sci U S A 2001; 98:1745-50. [PMID: 11172022 PMCID: PMC29328 DOI: 10.1073/pnas.98.4.1745] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The assembly of a pre-B cell receptor (pre-BCR) composed of an Ig mu heavy chain (mu H-chain), the surrogate light (SL) chain, and the Ig alpha/beta dimer is critical for late pro-B cells to advance to the pre-B cell stage. By using a transgenic mouse model, in which mu H-chain synthesis is solely driven by a tetracycline-controlled transactivator, we show that de novo synthesis of mu H-chain in transgenic pro-B cells not only induces differentiation but also proliferation. This positive effect of mu H-chain synthesis on proliferation requires the presence of SL chain and costimulatory signals provided by stromal cells or IL-7. We conclude that pre-BCR signaling induces clonal expansion of early pre-B cells.
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Affiliation(s)
- J Hess
- Institut für Medizinische Strahlenkunde und Zellforschung (MSZ), University of Würzburg, Versbacher Strasse 5, D-97078 Würzburg, Germany
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40
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Abstract
It has been suggested that B cells acquire the capacity for secondary V(D)J recombination during germinal center (GC) reactions. The nature of these B cells remains controversial. Subsets of tonsil and blood B cells and also individual B cells were examined for the expression of recombination-activating gene (RAG) mRNA. Semiquantitative analysis indicated that RAG1 mRNA was present in all tonsil B cell subsets, with the largest amount found in naive B cells. RAG2 mRNA was only found in tonsil naive B cells, centrocytes, and to a lesser extent in centroblasts. Neither RAG1 nor RAG2 mRNA was routinely found in normal peripheral blood B cells. In individual tonsil B cells, RAG1 and RAG2 mRNAs were found in 18% of naive B cells, 22% of GC founder cells, 0% of centroblasts, 13% of centrocytes, and 9% of memory B cells. Individual naive tonsil B cells containing both RAG1 and RAG2 mRNA were activated (CD69(+)). In normal peripheral blood approximately 5% of B cells expressed both RAG1 and RAG2. These cells were uniformly postswitch memory B cells as documented by the coexpression of IgG mRNA. These results indicate that coordinate RAG expression is not found in normal peripheral naive B cells but is up-regulated in naive B cells which are activated in the tonsil. With the exception of centroblasts, RAG1 and RAG2 expression can be found in all components of the GC, including postswitch memory B cells, some of which may circulate in the blood of normal subjects.
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Affiliation(s)
- H J Girschick
- Department of Internal Medicine, Harold C. Simmons Arthritis Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
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41
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Ohnishi K, Shimizu T, Karasuyama H, Melchers F. The identification of a nonclassical cadherin expressed during B cell development and its interaction with surrogate light chain. J Biol Chem 2000; 275:31134-44. [PMID: 10906147 DOI: 10.1074/jbc.m005901200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A 130-kDa glycoprotein (p130) has been found to be associated with surrogate light chain on pro- and pre-B I cells. Using peptide sequences obtained from purified p130 we have cloned its gene. The gene encodes a typical cadherin type 1 membrane protein with six extracellular cadherin domains (one pseudo domain) but lacking the catenin-binding site in its cytoplasmic part. Even without this catenin-binding site, p130 mediates Ca(2+)-dependent homotypic adhesion of cells. The interaction of p130 with surrogate light chain is confirmed by co-transfection and co-immunoprecipitation experiments. The expression of p130 is biphasic during the B cell development. Reverse transcriptase-polymerase chain reaction and flow cytometric analyses revealed that it is expressed on B220(+)c-Kit(+) pro-B and pre-B-I cells as well as on B220(+)CD25(-)IgM(+) immature and mature B cells but not on B220(+)CD25(+) pre-B-II cells. It is also expressed in fetal liver, at low levels in myeloid cells, and strongly in intestinal epithelial cells. In the spleen, p130-expressing cells are mainly localized in the marginal zone. We call this B lineage-, intestine-, liver- and leukocyte-expressed gene BILL-cadherin. The possible functions of BILL-cadherin in B cell development are discussed.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal
- B-Lymphocytes/chemistry
- B-Lymphocytes/cytology
- B-Lymphocytes/metabolism
- Base Sequence
- Binding Sites
- Blotting, Northern
- Cadherins/biosynthesis
- Cadherins/chemistry
- Cadherins/genetics
- Calcium/metabolism
- Cell Adhesion
- Cell Line
- Cloning, Molecular
- DNA, Complementary/metabolism
- Drosophila
- Female
- Flow Cytometry
- Gene Library
- Immunoglobulin Light Chains/chemistry
- Immunoglobulin Light Chains, Surrogate
- Immunoglobulin M/metabolism
- Immunoglobulin Variable Region/chemistry
- Intestinal Mucosa/metabolism
- Leukocyte Common Antigens/metabolism
- Leukocytes/metabolism
- Liver/metabolism
- Membrane Glycoproteins/chemistry
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Precipitin Tests
- Protein Structure, Tertiary
- Protein Tyrosine Phosphatase, Non-Receptor Type 1
- Proto-Oncogene Proteins c-kit/metabolism
- Rats
- Receptors, Interleukin-2/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Tissue Distribution
- Transfection
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Affiliation(s)
- K Ohnishi
- Basel Institute for Immunology, Grenzacherstrasse 487, CH-4005 Basel, Switzerland and the Department of Immunology, The Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613, Japan.
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42
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Sherwood EM, Xu W, King AM, Blomberg BB, Riley RL. The reduced expression of surrogate light chains in B cell precursors from senescent BALB/c mice is associated with decreased E2A proteins. Mech Ageing Dev 2000; 118:45-59. [PMID: 10989124 DOI: 10.1016/s0047-6374(00)00157-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Senescent mice exhibit decreased numbers of pre-B cells in the bone marrow. Herein, we show that the molecules, lambda5 and VpreB, which comprise the surrogate light chain component of the pre-B cell receptor, are reduced in pro-B/early pre-B cells derived in vitro from the bone marrow of 18-27 months old BALB/c mice after stimulation with IL-7. Both lambda5 and VpreB expression were decreased at the mRNA level as indicated by semi-quantitative RT-PCR; this suggests that the reduced surrogate light chains seen in senescent B cell precursors result from dysfunctional transcriptional regulation. The transcription of surrogate light chains is regulated, in part, by E2A (E47) gene products. Levels of E2A proteins, including E47, were decreased in senescent B cell precursors by up to 90%. Reduced E2A (E47) expression and subsequent reduced transcription of the surrogate light chain components lambda5 and VpreB may, in part, explain the diminished production of B lineage cells observed in senescence.
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Affiliation(s)
- E M Sherwood
- Department of Microbiology and Immunology, University of Miami School of Medicine, PO Box 016960 (R-138), Miami, FL 33101, USA
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43
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Muljo SA, Schlissel MS. Pre-B and pre-T-cell receptors: conservation of strategies in regulating early lymphocyte development. Immunol Rev 2000; 175:80-93. [PMID: 10933593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Early lymphocyte development is characterized by the regulated activity of the V(D)J recombinase and the positive and negative selection of cells based on the structure of their assembled antigen receptor genes. Developing B and T cells use remarkably similar signaling complexes, the pre-B-cell receptor (pre-BCR) and the pre-T-cell receptor (pre-TCR) respectively, to monitor the progress of antigen receptor gene assembly This review will compare and contrast the regulation and activities of the pre-BCR and pre-TCR signaling complexes. In addition, we will consider a number of critical but as yet unanswered questions prompted by such an analysis.
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Affiliation(s)
- S A Muljo
- Graduate Program in Immunology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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44
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Melchers F, ten Boekel E, Seidl T, Kong XC, Yamagami T, Onishi K, Shimizu T, Rolink AG, Andersson J. Repertoire selection by pre-B-cell receptors and B-cell receptors, and genetic control of B-cell development from immature to mature B cells. Immunol Rev 2000; 175:33-46. [PMID: 10933589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
During B-cell development the surrogate light (SL) chain is selectively expressed in progenitor and precursor B cells during the developmental stages of D(H) to J(H) and V(H) to D(H)J(H) rearrangements. Approximately half of all muH chains produced by these rearrangements cannot pair with SL chains and cannot form a pre-B-cell receptor (pre-BCR). A spectrum of affinities between VpreB and individual V(H) domains generates preB cells with pre-BCR of different fitness which, in turn, determines the extent of the pre-B II-cell proliferation and the fidelity of allelic exclusion of the H chain locus. Once pre-BCR is expressed, SL chain expression is turned off. As pre-B II cells proliferate, SL is diluted out, thus limiting pre-BCR formation. As a consequence, pre-B II cells stop proliferating, become small and resting and begin to rearrange the L chain loci. Multiple rearrangements of the kappaL chain alleles are often detected in wild-type small pre-B II cells. Around 20% of the muH chain-expressing small pre-B II cells also express L chains but do not display the Ig on the surface. Hence, it is likely that not all L chains originally generated in resting pre-B II cells can pair with the muH chain previously present in that cell. The best fitting ones are selected preferentially to generate sIg+ B cells. Furthermore, the transition of immature B cells from the bone marrow to spleen and their development to mature cells appear as two separate steps controlled by different genes.
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MESH Headings
- Alleles
- B-Lymphocytes/immunology
- Cell Differentiation
- Cell Lineage
- Gene Rearrangement, B-Lymphocyte, Heavy Chain
- Gene Rearrangement, B-Lymphocyte, Light Chain
- Genes, Immunoglobulin
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Heavy Chains/metabolism
- Immunoglobulin Light Chains/genetics
- Immunoglobulin Light Chains/metabolism
- Immunoglobulin Light Chains, Surrogate
- Immunoglobulin M/metabolism
- Immunoglobulin Variable Region/genetics
- Immunoglobulin Variable Region/metabolism
- Ligands
- Membrane Glycoproteins/metabolism
- Models, Biological
- Receptors, Antigen, B-Cell/immunology
- Receptors, Antigen, B-Cell/metabolism
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Affiliation(s)
- F Melchers
- The Basel Institute for Immunology, Switzerland.
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45
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Donohoe ME, Beck-Engeser GB, Lonberg N, Karasuyama H, Riley RL, Jäck HM, Blomberg BB. Transgenic human lambda 5 rescues the murine lambda 5 nullizygous phenotype. J Immunol 2000; 164:5269-76. [PMID: 10799888 DOI: 10.4049/jimmunol.164.10.5269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The human lambda 5 (hu lambda 5) gene is the structural homologue of the murine lambda 5 (m lambda 5) gene and is transcriptionally active in pro-B and pre-B lymphocytes. The lambda 5 and VpreB polypeptides together with the Ig mu H chain and the signal-transducing subunits, Ig alpha and Ig beta, comprise the pre-B cell receptor. To further investigate the pro-B/pre-B-specific transcription regulation of hu lambda 5 in an in vivo model, we generated mouse lines that contain a 28-kb genomic fragment encompassing the entire hu lambda 5 gene. High levels of expression of the transgenic hu lambda 5 gene were detected in bone marrow pro-B and pre-B cells at the mRNA and protein levels, suggesting that the 28-kb transgene fragment contains all the transcriptional elements necessary for the stage-specific B progenitor expression of hu lambda 5. Flow cytometric and immunoprecipitation analyses of bone marrow cells and Abelson murine leukemia virus-transformed pre-B cell lines revealed the hu lambda 5 polypeptide on the cell surface and in association with mouse Ig mu and mouse VpreB. Finally, we found that the hu lambda 5 transgene is able to rescue the pre-B lymphocyte block when bred onto the m lambda 5-/- background. Therefore, we conclude that the hu lambda 5 polypeptide can biochemically and functionally substitute for m lambda 5 in vivo in pre-B lymphocyte differentiation and proliferation. These studies on the mouse and human pre-B cell receptor provide a model system to investigate some of the molecular requirements necessary for B cell development.
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MESH Headings
- Abelson murine leukemia virus/genetics
- Animals
- B-Lymphocyte Subsets/cytology
- B-Lymphocyte Subsets/immunology
- B-Lymphocyte Subsets/metabolism
- Binding Sites, Antibody/genetics
- Bone Marrow Cells/immunology
- Bone Marrow Cells/metabolism
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Lineage/genetics
- Cell Lineage/immunology
- Crosses, Genetic
- Female
- Gene Expression Regulation/immunology
- Humans
- Immunoglobulin Heavy Chains/metabolism
- Immunoglobulin Light Chains
- Immunoglobulin Light Chains, Surrogate
- Immunoglobulin lambda-Chains/biosynthesis
- Immunoglobulin lambda-Chains/genetics
- Immunoglobulin lambda-Chains/metabolism
- Immunoglobulin mu-Chains/metabolism
- Immunophenotyping
- Male
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Transgenic
- Receptors, Antigen, B-Cell/biosynthesis
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Stem Cells/cytology
- Stem Cells/immunology
- Stem Cells/metabolism
- Testis/immunology
- Testis/metabolism
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Transgenes/immunology
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Affiliation(s)
- M E Donohoe
- Department of Microbiology, University of Miami School of Medicine, Miami, FL 33101, USA
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46
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Sigvardsson M. Overlapping expression of early B-cell factor and basic helix-loop-helix proteins as a mechanism to dictate B-lineage-specific activity of the lambda5 promoter. Mol Cell Biol 2000; 20:3640-54. [PMID: 10779354 PMCID: PMC85657 DOI: 10.1128/mcb.20.10.3640-3654.2000] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The basic helix-loop-helix (bHLH) transcription factors are a large group of proteins suggested to control key events in the development of B lymphocytes as well as of other cellular lineages. To examine how bHLH proteins activate a B-lineage-specific promoter, I investigated the ability of E47, E12, Heb, E2-2, and MyoD to activate the lambda5 surrogate light chain promoter. Comparison of the functional capacity of the E2A-encoded E47 and E12 proteins indicated that even though both were able to activate the lambda5 promoter and act in synergy with early B-cell factor (EBF), E47 displayed a higher functional activity than E12. An ability to act in synergy with EBF was also observed for Heb, E2-2, and MyoD, suggesting that these factors were functionally redundant in this regard. Mapping of functional domains in EBF and E47 revealed that the dimerization and DNA binding domains mediated the synergistic activity. Electrophoretic mobility shift assay analysis using the 5' part of the lambda5 promoter revealed formation of template-dependent heteromeric complexes between EBF and E47, suggesting that the synergistic mechanism involves cooperative binding to DNA. These findings propose a unique molecular function for E47 and provide overlapping expression with EBF as a molecular mechanism to direct B-cell-specific target gene activation by bHLH proteins.
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Affiliation(s)
- M Sigvardsson
- Immunology Group, CMB, Lund University, S-223 62 Lund, Sweden.
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47
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Ogawa M, ten Boekel E, Melchers F. Identification of CD19(-)B220(+)c-Kit(+)Flt3/Flk-2(+)cells as early B lymphoid precursors before pre-B-I cells in juvenile mouse bone marrow. Int Immunol 2000; 12:313-24. [PMID: 10700466 DOI: 10.1093/intimm/12.3.313] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The combined analysis of the expression of receptor tyrosine kinases c-Kit and Flt3/Flk-2 and of the human CD25 gene expressed as a transgene under the regulation of the mouse lambda5 promoter in the bone marrow of 1-week-old mice allows us to identify three stages of B lymphocyte development before the CD19(+)c-Kit(+) pre-B-I cells. Single-cell PCR analysis of the rearrangement status of the Ig heavy chain alleles allows us to order these early stages of B cell development as follows: (i) B220(+)CD19(-)c-Kit(lo)Flt3/Flk-2(hi)lambda5(-), (ii) B220(+)CD19(-)c-Kit(lo)Flt3/Flk-2(hi)lambda5(+) and (iii) B220(+)CD19(+)c-Kit(lo)Flt3/Flk-2(lo)lambda5(+) before B220(+)CD19(+)c-Kit(lo)Flt3/Flk-2(-)lambda5(+) pre-B-I cells. All these progenitors are clonable on stromal cells in the presence of IL-7 and can differentiate to CD19(+)c-Kit(-) B-lineage cells. A combination of stem cell factor, Flt3 ligand and IL-7 was also able to support the proliferation and differentiation of the progenitors in a suspension culture. Furthermore, the analyses indicate that the onset of D(H)J(H) rearrangements precedes the expression of the lambda5 gene. These progenitor populations were characteristic of juvenile mice and could not be detected in the bone marrow of adult mice. Hence the expression pattern, and probably the function, of the receptor tyrosine kinases in early B cell differentiation appears to be different in juvenile and adult mice.
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Affiliation(s)
- M Ogawa
- Basel Institute for Immunology, 4005 Basel, Switzerland
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48
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Abstract
The function of the pre-B cell receptor (pre-BCR) during B cell differentiation is not precisely defined. To investigate the pre-BCR receptor activity, we have established pre-BCR-positive pre-B cell lines that are able to differentiate into immature B cells in vitro. Antibody cross-linking of the pre-BCR induced apoptosis and differentiation accompanied with tyrosine phosphorylation. A specific tyrosine-phosphorylated 43 kDa protein (p43) was found down-stream of the pre-BCR. The results demonstrated the receptor function of pre-BCR, which indicates that a ligand-like molecule or a cross-linking structure on the cell surface is possibly present.
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Affiliation(s)
- I Kato
- Department of Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
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49
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Conley ME, Rapalus L, Boylin EC, Rohrer J, Minegishi Y. Gene conversion events contribute to the polymorphic variation of the surrogate light chain gene lambda 5/14.1. Clin Immunol 1999; 93:162-7. [PMID: 10527692 DOI: 10.1006/clim.1999.4785] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Normally occurring and experimentally induced models of immunodeficiency indicate that B cell development and antibody production are influenced by genetic factors. It is highly likely that polymorphic variants in genes that encode receptors for growth and differentiation factors, signal transduction molecules, and components of the B cell and pre-B-cell receptor complex contribute to this genetic control. We have identified a surprisingly large number of polymorphic variants in lambda5/14.1. Together with VpreB, lambda5/14.1 forms the surrogate light chain in the pre-B-cell receptor complex. Thirteen variant alleles of lambda5/14.1 were found in 134 unrelated individuals. Nine of these variants result in changes in the amino acid sequence of this small protein. The majority of the single base pair substitutions in lambda5/14.1 could be attributed to gene conversion events in which donor sequences from the lambda5 pseudogenes, 16.1, 16.2, and Glambda1, replace the wild-type sequence in the lambda5/14.1 functional gene. These findings indicate that gene conversion events play a major role in generating diversity that could affect stability or expression of the pre-B-cell receptor complex.
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Affiliation(s)
- M E Conley
- Department of Pediatrics, University of Tennessee College of Medicine, Memphis, Tennessee 38101, USA
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50
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Miyazaki T, Kato I, Takeshita S, Karasuyama H, Kudo A. Lambda5 is required for rearrangement of the Ig kappa light chain gene in pro-B cell lines. Int Immunol 1999; 11:1195-202. [PMID: 10421777 DOI: 10.1093/intimm/11.8.1195] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Lambda5 associates with V(pre-B) to form the surrogate light (L) chain. The phenotype of lambda5 knockout mice showed severe impairment of B cell development from pro-B to immature B cell stages. To investigate the function of the surrogate L chain at this stage, we restored expression of lambda5 to lambda5-deficient pro-B cell lines which were established from bone marrow cells of lambda5 knockout mice in the presence of IL-7 and a stromal cell line. Some of these lines are severely impaired in B cell development from pro-B to immature B cell stages as is seen in vivo in lambda5 knockout mice. Restoration of lambda5 protein by retroviral-mediated gene transfer into established lambda5-deficient pro-B cell lines induced rearrangement of the Ig kappa L chain genes after removal of IL-7 from the culture. Immunoprecipitation revealed that the restored lambda5 in the cell line is coupled with V(pre-B) to form the surrogate L chain. The results demonstrate that formation of a complete surrogate L chain, consisting of both lambda5 and V(pre-B), stimulates efficient rearrangement of the kappa L chain genes.
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Affiliation(s)
- T Miyazaki
- Department of Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
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