WorldWideScience

Sample records for b-cell gene bank1

  1. Genetic and Physical Interaction of the B-Cell SLE-Associated Genes BANK1 and BLK

    Science.gov (United States)

    Castillejo-López, Casimiro; Delgado-Vega, Angélica M.; Wojcik, Jerome; Kozyrev, Sergey V.; Thavathiru, Elangovan; Wu, Ying-Yu; Sánchez, Elena; Pöllmann, David; López-Egido, Juan R.; Fineschi, Serena; Domínguez, Nicolás; Lu, Rufei; James, Judith A.; Merrill, Joan T.; Kelly, Jennifer A.; Kaufman, Kenneth M.; Moser, Kathy; Gilkeson, Gary; Frostegård, Johan; Pons-Estel, Bernardo A.; D’Alfonso, Sandra; Witte, Torsten; Callejas, José Luis; Harley, John B.; Gaffney, Patrick; Martin, Javier; Guthridge, Joel M.; Alarcón-Riquelme, Marta E.

    2012-01-01

    Objectives Altered signaling in B-cells is a predominant feature of systemic lupus erythematosus (SLE). The genes BANK1 and BLK were recently described as associated with SLE. BANK1 codes for a B-cell-specific cytoplasmic protein involved in B-cell receptor signaling and BLK codes for an Src tyrosine kinase with important roles in B-cell development. To characterize the role of BANK1 and BLK in SLE, we performed a genetic interaction analysis hypothesizing that genetic interactions could reveal functional pathways relevant to disease pathogenesis. Methods We Used the method GPAT16 to analyze the gene-gene interactions of BANK1 and BLK. Confocal microscopy was used to investigate co-localization, and immunoprecipitation was used to verify the physical interaction of BANK1 and BLK. Results Epistatic interactions between BANK1 and BLK polymorphisms associated with SLE were observed in a discovery set of 279 patients and 515 controls from Northern Europe. A meta-analysis with 4399 European individuals confirmed the genetic interactions between BANK1 and BLK. As BANK1 was identified as a binding partner of the Src tyrosine kinase LYN, we tested the possibility that BANK1 and BLK could also show a protein-protein interaction. We demonstrated co-immunoprecipitation and co-localization of BLK and BANK1. In a Daudi cell line and primary naïve B-cells the endogenous binding was enhanced upon B-cell receptor stimulation using anti-IgM antibodies. Conclusions Here, we show a genetic interaction between BANK1 and BLK, and demonstrate that these molecules interact physically. Our results have important consequences for the understanding of SLE and other autoimmune diseases and identify a potential new signaling pathway. PMID:21978998

  2. Genetic and physical interaction of the B-cell systemic lupus erythematosus-associated genes BANK1 and BLK.

    Science.gov (United States)

    Castillejo-López, Casimiro; Delgado-Vega, Angélica M; Wojcik, Jerome; Kozyrev, Sergey V; Thavathiru, Elangovan; Wu, Ying-Yu; Sánchez, Elena; Pöllmann, David; López-Egido, Juan R; Fineschi, Serena; Domínguez, Nicolás; Lu, Rufei; James, Judith A; Merrill, Joan T; Kelly, Jennifer A; Kaufman, Kenneth M; Moser, Kathy L; Gilkeson, Gary; Frostegård, Johan; Pons-Estel, Bernardo A; D'Alfonso, Sandra; Witte, Torsten; Callejas, José Luis; Harley, John B; Gaffney, Patrick M; Martin, Javier; Guthridge, Joel M; Alarcón-Riquelme, Marta E

    2012-01-01

    Altered signalling in B cells is a predominant feature of systemic lupus erythematosus (SLE). The genes BANK1 and BLK were recently described as associated with SLE. BANK1 codes for a B-cell-specific cytoplasmic protein involved in B-cell receptor signalling and BLK codes for an Src tyrosine kinase with important roles in B-cell development. To characterise the role of BANK1 and BLK in SLE, a genetic interaction analysis was performed hypothesising that genetic interactions could reveal functional pathways relevant to disease pathogenesis. The GPAT16 method was used to analyse the gene-gene interactions of BANK1 and BLK. Confocal microscopy was used to investigate co-localisation, and immunoprecipitation was used to verify the physical interaction of BANK1 and BLK. Epistatic interactions between BANK1 and BLK polymorphisms associated with SLE were observed in a discovery set of 279 patients and 515 controls from northern Europe. A meta-analysis with 4399 European individuals confirmed the genetic interactions between BANK1 and BLK. As BANK1 was identified as a binding partner of the Src tyrosine kinase LYN, the possibility that BANK1 and BLK could also show a protein-protein interaction was tested. The co-immunoprecipitation and co-localisation of BLK and BANK1 were demonstrated. In a Daudi cell line and primary naive B cells endogenous binding was enhanced upon B-cell receptor stimulation using anti-IgM antibodies. This study shows a genetic interaction between BANK1 and BLK, and demonstrates that these molecules interact physically. The results have important consequences for the understanding of SLE and other autoimmune diseases and identify a potential new signalling pathway.

  3. Functional variants in the B-cell gene BANK1 are associated with systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Kozyrev, Sergey V; Abelson, Anna-Karin; Wojcik, Jerome

    2008-01-01

    -cell scaffold protein with ankyrin repeats gene, BANK1. We replicated the association in four independent case-control sets (combined P = 3.7 x 10(-10); OR = 1.38). We analyzed BANK1 cDNA and found two isoforms, one full-length and the other alternatively spliced and lacking exon 2 (Delta2), encoding a protein...... without a putative IP3R-binding domain. The transcripts were differentially expressed depending on a branch point-site SNP, rs17266594, in strong linkage disequilibrium (LD) with rs10516487. A third associated variant was found in the ankyrin domain (rs3733197, A383T). Our findings implicate BANK1...

  4. EVALUATION OF CYTOKINE GENE POLYMORPHISM IN B CELL LYMPHOID MALIGNANCIES

    Directory of Open Access Journals (Sweden)

    E. L. Nazarova

    2014-01-01

    Full Text Available Previous studies with some solid tumors has shown that polymorphisms of certain cytokine genes may be used as predictors of clinical outcome in the patients. It seemed important to evaluate potential correlations between production of certain pro- and anti-inflammatory cytokines and co-receptor molecules, and promoter polymorphism of the cytokine genes involved into regulation of cell proliferation, differentiation, apoptosis, lipid metabolism and blood clotting in the patients with hematological malignancies. The article contains our results concerning associations between of IL-1β, -2, -4, -10, -17, TNFα, and allelic polymorphisms of their genes in 62 patients with B cell lymphoid malignancies in an ethnically homogenous group (self-identified as Russians. We have shown that the GА and AA genotypes of the G-308A polymorphism in TNFα gene are significantly associated with increased production of this cytokine, being more common in aggressive non-Hodgkin lymphomas, more rare in multiple myeloma and in indolent non-Hodgkin lymphomas.

  5. Early B cell factor 1 regulates B cell gene networks by activation, repression, and transcription- independent poising of chromatin.

    Science.gov (United States)

    Treiber, Thomas; Mandel, Elizabeth M; Pott, Sebastian; Györy, Ildiko; Firner, Sonja; Liu, Edison T; Grosschedl, Rudolf

    2010-05-28

    The transcription factor early B cell factor-1 (Ebf1) is a key determinant of B lineage specification and differentiation. To gain insight into the molecular basis of Ebf1 function in early-stage B cells, we combined a genome-wide ChIP sequencing analysis with gain- and loss-of-function transcriptome analyses. Among 565 genes that are occupied and transcriptionally regulated by Ebf1, we identified large sets involved in (pre)-B cell receptor and Akt signaling, cell adhesion, and migration. Interestingly, a third of previously described Pax5 targets was found to be occupied by Ebf1. In addition to Ebf1-activated and -repressed genes, we identified targets at which Ebf1 induces chromatin changes that poise the genes for expression at subsequent stages of differentiation. Poised chromatin states on specific targets could also be established by Ebf1 expression in T cells but not in NIH 3T3 cells, suggesting that Ebf1 acts as a "pioneer" factor in a hematopoietic chromatin context. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Compound haploinsufficiencies of Ebf1 and Runx1 genes impede B cell lineage progression.

    Science.gov (United States)

    Lukin, Kara; Fields, Scott; Lopez, Desiree; Cherrier, Marie; Ternyak, Kristina; Ramírez, Julita; Feeney, Ann J; Hagman, James

    2010-04-27

    Early B cell factor (EBF)1 is essential for B lineage specification. Previously, we demonstrated the synergistic activation of Cd79a (mb-1) genes by EBF1 and its functional partner, RUNX1. Here, we identified consequences of Ebf1 haploinsufficiency together with haploinsufficiency of Runx1 genes in mice. Although numbers of "committed" pro-B cells were maintained in Ebf1(+/-)Runx1(+/-) (ER(het)) mice, activation of B cell-specific gene transcription was depressed in these cells. Expression of genes encoding Aiolos, kappa0 sterile transcripts, CD2 and CD25 were reduced and delayed in ER(het) pro-B cells, whereas surface expression of BP-1 was increased on late pro-B cells in ER(het) mice. Late pre-B and immature and mature B cells were decreased in the bone marrow of Ebf1(+/-) (E(het)) mice and were nearly absent in ER(het) mice. Although we did not observe significant effects of haploinsuficiencies on IgH or Igkappa rearrangements, a relative lack of Iglambda rearrangements was detected in E(het) and ER(het) pre-B cells. Together, these observations suggest that B cell lineage progression is impaired at multiple stages in the bone marrow of E(het) and ER(het) mice. Furthermore, enforced expression of EBF1 and RUNX1 in terminally differentiated plasmacytoma cells activated multiple early B cell-specific genes synergistically. Collectively, these studies illuminate the effects of reduced Ebf1 dosage and the compounding effects of reduced Runx1 dosage. Our data confirm and extend the importance of EBF1 in regulating target genes and Ig gene rearrangements necessary for B cell lineage specification, developmental progression, and homeostasis.

  7. Diagnostic value of immunoglobulin κ light chain gene rearrangement analysis in B-cell lymphomas.

    Science.gov (United States)

    Kokovic, Ira; Jezersek Novakovic, Barbara; Novakovic, Srdjan

    2015-03-01

    Analysis of the immunoglobulin κ light chain (IGK) gene is an alternative method for B-cell clonality assessment in the diagnosis of mature B-cell proliferations in which the detection of clonal immunoglobulin heavy chain (IGH) gene rearrangements fails. The aim of the present study was to evaluate the added value of standardized BIOMED-2 assay for the detection of clonal IGK gene rearrangements in the diagnostic setting of suspected B-cell lymphomas. With this purpose, 92 specimens from 80 patients with the final diagnosis of mature B-cell lymphoma (37 specimens), mature T-cell lymphoma (26 specimens) and reactive lymphoid proliferation (29 specimens) were analyzed for B-cell clonality. B-cell clonality analysis was performed using the BIOMED-2 IGH and IGK gene clonality assays. The determined sensitivity of the IGK assay was 67.6%, while the determined sensitivity of the IGH assay was 75.7%. The sensitivity of combined IGH+IGK assay was 81.1%. The determined specificity of the IGK assay was 96.2% in the group of T-cell lymphomas and 96.6% in the group of reactive lesions. The determined specificity of the IGH assay was 84.6% in the group of lymphomas and 86.2% in the group of reactive lesions. The comparison of GeneScan (GS) and heteroduplex pretreatment-polyacrylamide gel electrophoresis (HD-PAGE) methods for the analysis of IGK gene rearrangements showed a higher efficacy of GS analysis in a series of 27 B-cell lymphomas analyzed by both methods. In the present study, we demonstrated that by applying the combined IGH+IGK clonality assay the overall detection rate of B-cell clonality was increased by 5.4%. Thus, we confirmed the added value of the standardized BIOMED-2 IGK assay for assessment of B-cell clonality in suspected B-cell lymphomas with inconclusive clinical and cyto/histological diagnosis.

  8. Short-Circuiting Gene Regulatory Networks: Origins of B Cell Lymphoma

    Science.gov (United States)

    Koues, Olivia I.; Oltz, Eugene M.; Payton, Jacqueline E.

    2015-01-01

    B cell lymphomas (BCL) are characterized by widespread deregulation of gene expression when compared with their normal B cell counterparts. Recent epigenomic studies defined cis-regulatory elements (REs) whose activities are altered in BCL to drive some of these pathogenic expression changes. During transformation, multiple mechanisms are employed to alter RE activities, including perturbations in the function of chromatin modifiers, which can lead to revision of the B cell epigenome. Inherited and somatic variants also alter RE function via disruption of TF binding. Aberrant expression of non-coding RNAs deregulates genes involved in B cell differentiation via direct repression and post-transcriptional targeting. These discoveries have established epigenetic etiologies for B cell transformation that are being exploited by novel therapeutic approaches. PMID:26604030

  9. A dose-dependent role for EBF1 in repressing non-B-cell-specific genes.

    Science.gov (United States)

    Lukin, Kara; Fields, Scott; Guerrettaz, Lisa; Straign, Desiree; Rodriguez, Valerie; Zandi, Sasan; Månsson, Robert; Cambier, John C; Sigvardsson, Mikael; Hagman, James

    2011-06-01

    In the absence of early B-cell factor 1 (EBF1), B-cell development is arrested at an uncommitted progenitor stage that exhibits increased lineage potentials. Previously, we investigated the roles of EBF1 and its DNA-binding partner Runx1 by evaluating B lymphopoiesis in single (EBF1(het) and Runx1(het)) and compound haploinsufficent (Ebf1(+/-) Runx1(+/-), ER(het)) mice. Here, we demonstrate that decreased Ebf1 gene dosage results in the inappropriate expression of NK-cell lineage-specific genes in B-cell progenitors. Moreover, prolonged expression of Ly6a/Sca-1 suggested the maintenance of a relatively undifferentiated phenotype. These effects were exacerbated by reduced expression of Runx1 and occurred despite expression of Pax5. Repression of inappropriately expressed genes was restored in most pre-B and all immature B cells of ER(het) mice. Enforced EBF1 expression repressed promiscuous transcription in pro-B cells of ER(het) mice and in Ebf1(-/-) Pax5(-/-) fetal liver cells. Together, our studies suggest that normal levels of EBF1 are critical for maintaining B-cell identity by directing repression of non-B-cell-specific genes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. EBF1 acts as a powerful repressor of Blimp-1 gene expression in immature B cells.

    Science.gov (United States)

    Kikuchi, Hidehiko; Nakayama, Masami; Takami, Yasunari; Kuribayashi, Futoshi; Nakayama, Tatsuo

    2012-06-15

    The transcription factor, early B cell factor 1 (EBF1) with an atypical zinc-finger and helix-loop-helix motif, is essential for development and differentiation of lymphocytes. In mice, EBF1 is involved in the generation of pre-pro B cells (the first specified progenitors of B cells) from common lymphoid progenitors (CLPs) and transcription regulations of various genes involved in B cell-development, for instance, mb-1 and Pax5. During B lymphopoiesis, interestingly, EBF1 is detected throughout from CLPs to mature B cells. However, in immature B cells, the physiological role of EBF1 remains to be elucidated. Here, by analyzing EBF1-deficient DT40 cells, EBF1(-/-), generated by us, we show that EBF1-deficiency caused significant increases (to ∼800%) in both mRNA and protein levels of B lymphocyte-induced maturation protein-1 (Blimp-1), the master gene for plasma cell differentiation. In addition, both transcription and protein synthesis of Blimp-1 were remarkably down-regulated (to ∼20%) by re-expression (over-expression) of EBF1. Chromatin immunoprecipitation assay revealed that EBF1 binds to proximal 5'-upstream regions around two putative EBF1 binding motifs of the gene in vivo. These results suggest that EBF1 takes part in transcriptional regulations of the Blimp-1 gene in immature B cells, and may play a key role in B cell differentiation. This is the first report on a novel EBF1 function in immature B cells as a powerful repressor of Blimp-1 gene expression. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Hoxa9 collaborates with E2A-PBX1 in mouse B cell leukemia in association with Flt3 activation and decrease of B cell gene expression.

    Science.gov (United States)

    Hassawi, Mona; Shestakova, Elena A; Fournier, Marilaine; Lebert-Ghali, Charles-Étienne; Vaisson, Gratianne; Frison, Héloïse; Sinnett, Daniel; Vidal, Ramon; Thompson, Alexander; Bijl, Janet J

    2014-01-01

    The fusion protein E2A-PBX1 induces pediatric B cell leukemia in human. Previously, we reported oncogenic interactions between homeobox (Hox) genes and E2A-PBX1 in murine T cell leukemia. A proviral insertional mutagenesis screen with our E2A-PBX1 B cell leukemia mouse model identified Hoxa genes as potential collaborators to E2A-PBX1. Here we studied whether Hoxa9 could enhance E2A-PBX1 leukemogenesis. We show that Hoxa9 confers a proliferative advantage to E2A-PBX1 B cells. Transplantation experiments with E2A-PBX1 transgenic B cells overexpressing Hoxa9 isolated from bone marrow chimeras showed that Hoxa9 accelerates the generation of E2A-PBX1 B cell leukemia, but Hoxa9 is unable to transform B cells alone. Quantitative-reverse transcriptase polymerase chain reaction analysis demonstrated a strong repression of B cell specific genes in these E2A-PBX1/Hoxa9 leukemias in addition to Flt3 activation, indicating inhibition of B cell differentiation in combination with enhanced proliferation. Overexpression of Hoxa9 in established E2A-PBX1 mouse leukemic B cells resulted in a growth advantage in vitro, which was also characterized by an enhanced expression of Flt3. we show for the first time that Hoxa9 collaborates with E2A-PBX1 in the oncogenic transformation of B cells in a mouse model that involves Flt3 signaling, which is potentially relevant to human disease. Copyright © 2013 Wiley Periodicals, Inc.

  12. IL-4-Induced Gene 1: A Negative Immune Checkpoint Controlling B Cell Differentiation and Activation.

    Science.gov (United States)

    Bod, Lloyd; Douguet, Laetitia; Auffray, Cédric; Lengagne, Renée; Bekkat, Fériel; Rondeau, Elena; Molinier-Frenkel, Valérie; Castellano, Flavia; Richard, Yolande; Prévost-Blondel, Armelle

    2018-02-01

    Emerging data highlight the crucial role of enzymes involved in amino acid metabolism in immune cell biology. IL-4-induced gene-1 (IL4I1), a secreted l-phenylalanine oxidase expressed by APCs, has been detected in B cells, yet its immunoregulatory role has only been explored on T cells. In this study, we show that IL4I1 regulates multiple steps in B cell physiology. Indeed, IL4I1 knockout mice exhibit an accelerated B cell egress from the bone marrow, resulting in the accumulation of peripheral follicular B cells. They also present a higher serum level of natural Igs and self-reactive Abs. We also demonstrate that IL4I1 produced by B cells themselves controls the germinal center reaction, plasma cell differentiation, and specific Ab production in response to T dependent Ags, SRBC, and NP-KLH. In vitro, IL4I1-deficient B cells proliferate more efficiently than their wild-type counterparts in response to BCR cross-linking. Moreover, the absence of IL4I1 increases activation of the Syk-Akt-S6kinase signaling pathway and calcium mobilization, and inhibits SHP-1 activity upon BCR engagement, thus supporting that IL4I1 negatively controls BCR-dependent activation. Overall, our study reveals a new perspective on IL4I1 as a key regulator of B cell biology. Copyright © 2018 by The American Association of Immunologists, Inc.

  13. Early B-cell factor 1 (EBF1) is critical for transcriptional control of SLAMF1 gene in human B cells.

    Science.gov (United States)

    Schwartz, Anton M; Putlyaeva, Lidia V; Covich, Milica; Klepikova, Anna V; Akulich, Kseniya A; Vorontsov, Ilya E; Korneev, Kirill V; Dmitriev, Sergey E; Polanovsky, Oleg L; Sidorenko, Svetlana P; Kulakovskiy, Ivan V; Kuprash, Dmitry V

    2016-10-01

    Signaling lymphocytic activation molecule family member 1 (SLAMF1)/CD150 is a co-stimulatory receptor expressed on a variety of hematopoietic cells, in particular on mature lymphocytes activated by specific antigen, costimulation and cytokines. Changes in CD150 expression level have been reported in association with autoimmunity and with B-cell chronic lymphocytic leukemia. We characterized the core promoter for SLAMF1 gene in human B-cell lines and explored binding sites for a number of transcription factors involved in B cell differentiation and activation. Mutations of SP1, STAT6, IRF4, NF-kB, ELF1, TCF3, and SPI1/PU.1 sites resulted in significantly decreased promoter activity of varying magnitude, depending on the cell line tested. The most profound effect on the promoter strength was observed upon mutation of the binding site for Early B-cell factor 1 (EBF1). This mutation produced a 10-20 fold drop in promoter activity and pinpointed EBF1 as the master regulator of human SLAMF1 gene in B cells. We also identified three potent transcriptional enhancers in human SLAMF1 locus, each containing functional EBF1 binding sites. Thus, EBF1 interacts with specific binding sites located both in the promoter and in the enhancer regions of the SLAMF1 gene and is critical for its expression in human B cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A critical role of the Thy28-MYH9 axis in B cell-specific expression of the Pax5 gene in chicken B cells.

    Directory of Open Access Journals (Sweden)

    Toshitsugu Fujita

    Full Text Available Accumulating evidence suggests that Pax5 plays essential roles in B cell lineage commitment. However, molecular mechanisms of B cell-specific expression of Pax5 are not fully understood. Here, we applied insertional chromatin immunoprecipitation (iChIP combined with stable isotope labeling using amino acids in cell culture (SILAC (iChIP-SILAC to direct identification of proteins interacting with the promoter region of the endogenous single-copy chicken Pax5 gene. By comparing B cells with macrophage-like cells trans-differentiated by ectopic expression of C/EBPβ, iChIP-SILAC detected B cell-specific interaction of a nuclear protein, Thy28/Thyn1, with the Pax5 1A promoter. Trans-differentiation of B cells into macrophage-like cells caused down-regulation of Thy28 expression. Loss-of-function of Thy28 induced decrease in Pax5 expression and recruitment of myosin-9 (MYH9, one of Thy28-interacting proteins, to the Pax5 1A promoter. Loss-of-function of MYH9 also induced decrease in Pax5 expression. Thus, our analysis revealed that Thy28 is functionally required for B cell-specific expression of Pax5 via recruitment of MYH9 to the Pax5 locus in chicken B cells.

  15. BANK1 Regulates IgG Production in a Lupus Model by Controlling TLR7-Dependent STAT1 Activation.

    Directory of Open Access Journals (Sweden)

    Ying-Yu Wu

    Full Text Available The purpose of our study was to investigate the effects of the adaptor Bank1 in TLR7 signaling using the B6.Sle1.yaa mouse, a lupus model that develops disease through exacerbated TLR7 expression. Crosses of B6.Sle1.yaa with Bank1-/- mice maintained several B and myeloid cell phenotypes close to normal wild-type levels. Most striking was the reduction in total serum IgG antibodies, but not of IgM, and reduced serum levels of autoantibodies, IL-6, and BAFF. Bank1 deficiency did modify numbers of MZ B cells and total B cell numbers, as well as expression of CXCR4 by follicular helper T cells. Other T cell changes were not observed. Bank1 deficiency did not modify numbers of germinal center B cells or plasma cells or clinical disease outcomes. Purified B cells from Bank1 deficient mice had strongly reduced Ifnb, Ifna4, Irf7, Aicda and Stat1 gene expression following TLR7 agonist stimulation. Interestingly, phosphorylation of Tyr701, but not of Ser727 of STAT1, was impaired in splenic B cells from B6.Sle1.yaa.Bank1-/- mice, as was the nuclear translocation of IRF7 in response to TLR7 agonist stimulation. Further, Bank1 deficiency in B6.Sle1.yaa mice reduced the production of IgG2c after in vitro TLR7 agonist stimulation. Our results demonstrate that Bank1 controls TLR7-mediated type I interferon production. Combined with the control of the nuclear translocation of IRF7, the modulation of STAT1 transcription and phosphorylation, Bank1 contributes to IgG production during development of autoimmune disease.

  16. Identification of genes encoding critical factors regulating B-cell terminal differentiation in torafugu (Takifugu rubripes).

    Science.gov (United States)

    Ohtani, Maki; Miyadai, Toshiaki; Hiroishi, Shingo

    2006-03-01

    Many transcription factors, and associated co-factors, are involved in the regulation of B-cell terminal differentiation in mammals. In the teleost and cartilaginous fish, although evidence has strongly suggested the existence of B-cell like lymphocytes, the mechanism of terminal differentiation of B-cells remains to be elucidated. In the present study, we searched for the nucleotide and amino acid sequences similar to the critical regulatory factors facilitating the terminal differentiation of B-cells using the fugu BLAST server. We cloned the following cDNAs from Takifugu rubripes: (1) B-lymphocyte-induced maturation protein-1 (Blimp-1), which plays a major role in promoting plasma cell differentiation by repressing the transcription of many genes that participate in maintaining the differentiation of mature B-cells; (2) Bcl-6, which facilitates germinal center formation and represses Blimp-1 expression; (3) X-box binding protein-1 (XBP-1), which operates Ig secretion by activating transcription of the ER-stress responsible genes; (4) Pax-5, which suppresses XBP-1 and enhances the expression of activation-induced cytidine deaminase (AID), an inducer of somatic hypermutation and class-switch recombination of the immunoglobulin gene; and (5) TLE-3, one of the Groucho family proteins, a co-factor for Blimp-1. We also identified other co-factors and many target genes of Blimp-1 by in silico and/or cDNA cloning. These finding indicates that the basal process of B-cell terminal differentiation in fish is controlled by factors identical to those in mammals.

  17. Epigenetic Heterogeneity of B-Cell Lymphoma: DNA Methylation, Gene Expression and Chromatin States

    Directory of Open Access Journals (Sweden)

    Lydia Hopp

    2015-09-01

    Full Text Available Mature B-cell lymphoma is a clinically and biologically highly diverse disease. Its diagnosis and prognosis is a challenge due to its molecular heterogeneity and diverse regimes of biological dysfunctions, which are partly driven by epigenetic mechanisms. We here present an integrative analysis of DNA methylation and gene expression data of several lymphoma subtypes. Our study confirms previous results about the role of stemness genes during development and maturation of B-cells and their dysfunction in lymphoma locking in more proliferative or immune-reactive states referring to B-cell functionalities in the dark and light zone of the germinal center and also in plasma cells. These dysfunctions are governed by widespread epigenetic effects altering the promoter methylation of the involved genes, their activity status as moderated by histone modifications and also by chromatin remodeling. We identified four groups of genes showing characteristic expression and methylation signatures among Burkitt’s lymphoma, diffuse large B cell lymphoma, follicular lymphoma and multiple myeloma. These signatures are associated with epigenetic effects such as remodeling from transcriptionally inactive into active chromatin states, differential promoter methylation and the enrichment of targets of transcription factors such as EZH2 and SUZ12.

  18. MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures

    DEFF Research Database (Denmark)

    Hu, Shimin; Xu-Monette, Zijun Y; Tzankov, Alexander

    2013-01-01

    Diffuse large B-cell lymphoma (DLBCL) is stratified into prognostically favorable germinal center B-cell (GCB)-like and unfavorable activated B-cell (ABC)-like subtypes based on gene expression signatures. In this study, we analyzed 893 de novo DLBCL patients treated with R-CHOP (rituximab...

  19. B-cell subpopulations from normal human secondary lymphoid tissues with specific gene expression profiles and phenotypes

    DEFF Research Database (Denmark)

    Johnsen, Hans Erik; Schmitz, Alexander; Perez Andres, Martin

    In order to improve insights into the B-cell biology and thereby B-cell myelomagenesis we have established a MSCNET standard for multiparametric flow cytometry (MFC) and cell sorting (FACS) for subsequent genetic analysis. The material analysed was fresh tonsils, blood and bone marrow. The method...... and single gene expression analysis (qRT-PCR) for transcription factors as well as global gene expression profiling (GEP; GeneChip Human Exon 1.0 ST Array). For example for tonsils, based on the immunophenotypic presentation (including CD3/44/CXCR4 in the panel), B-cell subsets were identified and sorted......-cell subpopulations identified have distinct gene expression profiles reflecting their functions but also revealing genes with subpopulation specific exon splicing. In conclusion a combination of surface markers expressed antigens and gene expression analysis of B cell subsets confirm a strong methodology to be used...

  20. Bioinformatics analysis of gene expression profiles in B cells of postmenopausal osteoporosis patients.

    Science.gov (United States)

    Ma, Min; Luo, Shulin; Zhou, Wei; Lu, Liangyu; Cai, Junfeng; Yuan, Feng; Yin, Feng

    2017-04-01

    The aim of this study was to gain a better understanding of the molecular mechanisms and identify more critical genes associated with the pathogenesis of postmenopausal osteoporosis (PMOP). Microarray data of GSE13850 were download from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified either in B cells from postmenopausal female nonsmokers with high bone mineral density (BMD) compared with those with low BMD (defined as DEG1 group) or in B cells from postmenopausal female smokers with high BMD compared with postmenopausal female nonsmokers with high BMD (defined as DEG2 group). Gene ontology and immune-related functional enrichment analysis of DEGs were performed. Additionally, the protein-protein interaction network of all DEGs was constructed and subnetworks of the hub genes were extracted. A total of 51 DEGs were identified in the DEG1 group, including 30 up- and 21 downregulated genes. Besides, 86 DEGs were identified in the DEG2 group, of which 46 were upregulated and 40 were downregulated. Immune enrichment analysis showed DEGs were mainly enriched in functions of CD molecules and chemokines and receptor, and the upregulated gene interleukin 4 receptor (IL-4R) was significantly enriched. Moreover, guanine nucleotide-binding protein G (GNAI2), filamin A alpha (FLNA), and transforming growth factor-β1 (TGFB1) were hub proteins in the protein-protein interaction network. IL-4R, GNAI2, FLNA, and TGFB1 may be potential target genes associated with the pathogenesis of PMOP. In particular, FLNA, and TGFB1 may be affected by smoking, a risk factor of PMOP. Copyright © 2017. Published by Elsevier B.V.

  1. A gene panel, including LRP12, is frequently hypermethylated in major types of B-cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Nicole Bethge

    Full Text Available Epigenetic modifications and DNA methylation in particular, have been recognized as important mechanisms to alter gene expression in malignant cells. Here, we identified candidate genes which were upregulated after an epigenetic treatment of B-cell lymphoma cell lines (Burkitt's lymphoma, BL; Follicular lymphoma, FL; Diffuse large B-cell lymphoma, DLBCL activated B-cell like, ABC; and germinal center like, GCB and simultaneously expressed at low levels in samples from lymphoma patients. Qualitative methylation analysis of 24 candidate genes in cell lines revealed five methylated genes (BMP7, BMPER, CDH1, DUSP4 and LRP12, which were further subjected to quantitative methylation analysis in clinical samples from 59 lymphoma patients (BL, FL, DLBCL ABC and GCB; and primary mediastinal B-cell lymphoma, PMBL. The genes LRP12 and CDH1 showed the highest methylation frequencies (94% and 92%, respectively. BMPER (58%, DUSP4 (32% and BMP7 (22%, were also frequently methylated in patient samples. Importantly, all gene promoters were unmethylated in various control samples (CD19+ peripheral blood B cells, peripheral blood mononuclear cells and tonsils as well as in follicular hyperplasia samples, underscoring a high specificity. The combination of LRP12 and CDH1 methylation could successfully discriminate between the vast majority of the lymphoma and control samples, emphasized by receiver operating characteristic analysis with a c-statistic of 0.999. These two genes represent promising epigenetic markers which may be suitable for monitoring of B-cell lymphoma.

  2. E2A proteins are required for proper B cell development and initiation of immunoglobulin gene rearrangements

    NARCIS (Netherlands)

    Bain, G.; Maandag, E. C.; Izon, D. J.; Amsen, D.; Kruisbeek, A. M.; Weintraub, B. C.; Krop, I.; Schlissel, M. S.; Feeney, A. J.; van Roon, M.

    1994-01-01

    E12 and E47 are two helix-loop-helix transcription factors that arise by alternative splicing of the E2A gene. Both have been implicated in the regulation of immunoglobulin gene expression. We have now generated E2A (-/-) mice by gene targeting. E2A-null mutant mice fail to generate mature B cells.

  3. Inherited Inflammatory Response Genes Are Associated with B-Cell Non-Hodgkin's Lymphoma Risk and Survival.

    Directory of Open Access Journals (Sweden)

    Kaspar René Nielsen

    Full Text Available Malignant B-cell clones are affected by both acquired genetic alterations and by inherited genetic variations changing the inflammatory tumour microenvironment.We investigated 50 inflammatory response gene polymorphisms in 355 B-cell non-Hodgkin's lymphoma (B-NHL samples encompassing 216 diffuse large B cell lymphoma (DLBCL and 139 follicular lymphoma (FL and 307 controls. The effect of single genes and haplotypes were investigated and gene-expression analysis was applied for selected genes. Since interaction between risk genes can have a large impact on phenotype, two-way gene-gene interaction analysis was included.We found inherited SNPs in genes critical for inflammatory pathways; TLR9, IL4, TAP2, IL2RA, FCGR2A, TNFA, IL10RB, GALNT12, IL12A and IL1B were significantly associated with disease risk and SELE, IL1RN, TNFA, TAP2, MBL2, IL5, CX3CR1, CHI3L1 and IL12A were, associated with overall survival (OS in specific diagnostic entities of B-NHL. We discovered noteworthy interactions between DLBCL risk alleles on IL10 and IL4RA and FL risk alleles on IL4RA and IL4. In relation to OS, a highly significant interaction was observed in DLBCL for IL4RA (rs1805010 * IL10 (rs1800890 (HR = 0.11 (0.02-0.50. Finally, we explored the expression of risk genes from the gene-gene interaction analysis in normal B-cell subtypes showing a different expression of IL4RA, IL10, IL10RB genes supporting a pathogenetic effect of these interactions in the germinal center.The present findings support the importance of inflammatory genes in B-cell lymphomas. We found association between polymorphic sites in inflammatory response genes and risk as well as outcome in B-NHL and suggest an effect of gene-gene interactions during the stepwise oncogenesis.

  4. Global changes in the nuclear positioning of genes and intra- and interdomain genomic interactions that orchestrate B cell fate.

    Science.gov (United States)

    Lin, Yin C; Benner, Christopher; Mansson, Robert; Heinz, Sven; Miyazaki, Kazuko; Miyazaki, Masaki; Chandra, Vivek; Bossen, Claudia; Glass, Christopher K; Murre, Cornelis

    2012-12-01

    The genome is folded into domains located in compartments that are either transcriptionally inert or transcriptionally permissive. Here we used genome-wide strategies to characterize domains during B cell development. Structured interaction matrix analysis showed that occupancy by the architectural protein CTCF was associated mainly with intradomain interactions, whereas sites bound by the histone acetyltransferase p300 or the transcription factors E2A or PU.1 were associated with intra- and interdomain interactions that are developmentally regulated. We identified a spectrum of genes that switched nuclear location during early B cell development. In progenitor cells, the transcriptionally inactive locus encoding early B cell factor (Ebf1) was sequestered at the nuclear lamina, which thereby preserved their multipotency. After development into the pro-B cell stage, Ebf1 and other genes switched compartments to establish new intra- and interdomain interactions associated with a B lineage-specific transcription signature.

  5. The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development.

    Science.gov (United States)

    Ortega-Molina, Ana; Boss, Isaac W; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A; Gascoyne, Randy D; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M; Wendel, Hans-Guido

    2015-10-01

    The gene encoding the lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma and diffuse large B cell lymphoma; however, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center involution and impedes B cell differentiation and class switch recombination. Integrative genomic analyses indicate that KMT2D affects methylation of lysine 4 on histone H3 (H3K4) and expression of a set of genes, including those in the CD40, JAK-STAT, Toll-like receptor and B cell receptor signaling pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3 and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell-activating pathways.

  6. Different spectra of recurrent gene mutations in subsets of chronic lymphocytic leukemia harboring stereotyped B-cell receptors

    DEFF Research Database (Denmark)

    Sutton, Lesley-Ann; Young, Emma; Baliakas, Panagiotis

    2016-01-01

    We report on markedly different frequencies of genetic lesions within subsets of chronic lymphocytic leukemia patients carrying mutated or unmutated stereotyped B-cell receptor immunoglobulins in the largest cohort (n=565) studied for this purpose. By combining data on recurrent gene mutations...... subsets implies that the mechanisms underlying clinical aggressiveness are not uniform, but rather support the existence of distinct genetic pathways of clonal evolution governed by a particular stereotyped B-cell receptor selecting a certain molecular lesion(s)....

  7. Immune Modulatory Cell Therapy for Hemophilia B Based on CD20-Targeted Lentiviral Gene Transfer to Primary B Cells

    Directory of Open Access Journals (Sweden)

    Xiaomei Wang

    2017-06-01

    Full Text Available Gene-modified B cells expressing immunoglobulin G (IgG fusion proteins have been shown to induce tolerance in several autoimmune and other disease models. However, lack of a vector suitable for gene transfer to human B cells has been an obstacle for translation of this approach. To overcome this hurdle, we developed an IgG-human factor IX (hFIX lentiviral fusion construct that was targeted to specifically transduce cells expressing human CD20 (hCD20. Receptor-specific retargeting by mutating envelope glycoproteins of measles virus (MV-lentiviral vector (LV and addition of a single-chain variable fragment specific for hCD20 resulted in gene delivery into primary human and transgenic hCD20 mouse B cells with high specificity. Notably, this protocol neither required nor induced activation of the B cells, as confirmed by minimal activation of inflammatory cytokines. Using this strategy, we were able to demonstrate induction of humoral tolerance, resulting in suppression of antibody formation against hFIX in a mouse model of hemophilia B (HB. In conclusion, transduction of receptor-specific retargeted LV into resting B cells is a promising method to develop B cell therapies for antigen-specific tolerance induction in human disease.

  8. Differential gene expression in human hepatocellular carcinoma Hep3B cells induced by apoptosis-related gene BNIPL-2.

    Science.gov (United States)

    Xie, Li; Qin, Wen-Xin; He, Xiang-Huo; Shu, Hui-Qun; Yao, Gen-Fu; Wan, Da-Fang; Gu, Jian-Ren

    2004-05-01

    Bcl-2/adenovirus E1B 19 ku interacting protein 2-like (BNIPL-2) is a novel protein recently identified in our laboratory. BNIPL-2 is homologous to human BNIP-2, a potentially proapoptotic protein, and can interact with Bcl-2 and Cdc42GAP and promote apoptosis in BEL-7402 cells. Here we report the gene-expression profile regulated by BNIPL-2 in human hepatocarcinoma Hep3B cells and the analysis of its potential roles in cell apoptosis. BNIPL-2 was overexpressed in Hep3B cells using tetracycline inducible or Tet-on system. Screened by Western blot, the cells with low background and high induction fold of BNIPL-2 were obtained. We performed Atlas human cDNA expression array hybridization on these cells and analyzed the data with Quantarray software to identify BNIPL-2-regulated genes and their expression profile. RT-PCR was used to confirm the altered expression level of part of genes identified by the Atlas array hybridization. Fifteen of 588 genes spotted on the Atlas membrane showed altered expression levels in BNIPL-2-transfected Hep3B-Tet-on cells, in which 8 genes involved in cell apoptosis or growth inhibition were up-regulated and 7 genes involved in cellular proliferation were down-regulated following overexpression of BNIPL-2. cDNA array is a powerful tool to explore gene expression profiles under inducible conditions. The data obtained using the cDNA expression microarray technology indicates that BNIPL-2 may play its roles in apoptosis through regulating the expression of genes associated with cell apoptosis, growth inhibition and cell proliferation.

  9. B-cell subpopulations from normal human secondary lymphoid tissues with specific gene expression profiles and phenotypes

    DEFF Research Database (Denmark)

    Johnsen, Hans Erik; Schmitz, Alexander; Perez Andres, Martin

    In order to improve insights into the B-cell biology and thereby B-cell myelomagenesis we have established a MSCNET standard for multiparametric flow cytometry (MFC) and cell sorting (FACS) for subsequent genetic analysis. The material analysed was fresh tonsils, blood and bone marrow. The method...... and single gene expression analysis (qRT-PCR) for transcription factors as well as global gene expression profiling (GEP; GeneChip Human Exon 1.0 ST Array). For example for tonsils, based on the immunophenotypic presentation (including CD3/44/CXCR4 in the panel), B-cell subsets were identified and sorted......, naïve, centroblast, centrocyte, memory, and plasmablasts. The identity of the tonsillar subpopulations was verified using qRT-PCR and exon microarray GEP based on the used discriminative phenotypic markers as well as transcriptions factors BACH2, BCL6, PAX5, IRF4, P27, PRDM1 and XBP1. Globally, the B...

  10. Identification of Primary Mediastinal Large B-cell Lymphoma at Nonmediastinal Sites by Gene Expression Profiling.

    Science.gov (United States)

    Yuan, Ji; Wright, George; Rosenwald, Andreas; Steidl, Christian; Gascoyne, Randy D; Connors, Joseph M; Mottok, Anja; Weisenburger, Dennis D; Greiner, Timothy C; Fu, Kai; Smith, Lynette; Rimsza, Lisa M; Jaffe, Elaine S; Campo, Elias; Martinez, Antonio; Delabie, Jan; Braziel, Rita M; Cook, James R; Ott, German; Vose, Julie M; Staudt, Louis M; Chan, Wing C

    2015-10-01

    Mediastinal involvement is considered essential for the diagnosis of primary mediastinal large B-cell lymphoma (PMBL). However, we have observed cases of diffuse large B-cell lymphoma (DLBCL) with features of PMBL but without detectable mediastinal involvement. The goal was to assess our previously established gene expression profiling (GEP) signature for PMBL in classifying these cases. In a large series of DLBCL cases, we identified 24 cases with a GEP signature of PMBL, including 9 cases with a submission diagnosis of DLBCL consistent with PMBL (G-PMBL-P) and 15 cases with a submission diagnosis of DLBCL. The pathology reviewers agreed with the diagnosis in the 9 G-PMBL-P cases. Among the other 15 DLBCL cases, 11 were considered to be PMBL or DLBCL consistent with PMBL, 3 were considered to be DLBCL, and 1 case was a gray-zone lymphoma with features intermediate between DLBCL and classical Hodgkin lymphoma. All 9 G-PMBL-P and 9 of the 15 DLBCL cases (G-PMBL-M) had demonstrated mediastinal involvement at presentation. Interestingly, 6 of the 15 DLBCL cases (G-PMBL-NM) had no clinical or radiologic evidence of mediastinal involvement. The 3 subgroups of PMBL had otherwise similar clinical characteristics, and there were no significant differences in overall survival. Genetic alterations of CIITA and PDL1/2 were detected in 26% and 40% of cases, respectively, including 1 G-PMBL-NM case with gain of PDL1/2. In conclusion, PMBL can present as a nonmediastinal tumor without evidence of mediastinal involvement, and GEP offers a more precise diagnosis of PMBL.

  11. Comparison of immunological characteristics of peripheral, splenic and tonsilar naïve B cells by differential gene expression meta-analyses.

    Science.gov (United States)

    Chokeshai-u-saha, Kaj; Lepoivre, Cyrille; Grieco, Luca; Nguyen, Catherine; Ruxrungtham, Kiat

    2012-12-01

    Naïve B cells isolated from peripheral blood, spleen and tonsil are commonly used in human B cell studies. However, little has been written about their possible variations in immunological properties. This study compared differential gene expression in human naive B subsets by meta-analysis using expression data available in Gene Expression Onimbus (GEO). Gene expression files of the Affymetrix Human Genome U133A Array (Affymetrix) were downloaded to collect 21 total array data samples of peripheral naïve B cells (n=10), splenic naïve B cells (n=2), tonsilar naïve B cells (n=3), peripheral memory B cells (n=4) and splenic memory B cells (n=2). Prior to differential gene expression analyses, data were normalized in order to reduce non-biological variation among the datasets. Comparisons of peripheral naive B cells with their splenic and tonsilar counterparts showed remarkable differences in terms of gene expression (29 and 202 genes, respectively). However, only minor differences were detected between splenic and tonsilar naive B cells (10 genes), consistent with the clustering results classifying both of them as lymphoid naive B cells. Differential gene expression results also implied higher stimulating states of lymphoid naive B cells when compared with peripheral blood naive B cells. These included enhanced expressions of CD27, CR2, EGR1, GADD45B, ICAM1, ICOSLG, IGHA, IL6, MMP9, SAMSN1, SMAD7, TNFAIP3, but reduced HLA-DOB expression. Our findings suggest that results generated from peripheral naive B cells may not always be applicable to the biological activities of other lymphoid naïve B cells. Nonetheless, further biological study is warranted.

  12. B-cell translocation gene 1 is downregulated by promoter methylation in ovarian carcinoma.

    Science.gov (United States)

    Kim, Ji-Ye; Do, Sung-Im; Bae, Go Eun; Kim, Hyun-Soo

    2017-01-01

    A better understanding of tumor biology is important in the identification of molecules that are downregulated in malignancy and in determining their role in tumor suppression. B-cell translocation gene 1 (BTG1) has been shown to act as a tumor suppressor in several types of human malignancy. In this study, we analyzed BTG1 expression in ovarian carcinoma cell lines, and we investigated the mechanism underlying the observed alterations. The methylation status of the BTG1 promoter region was determined by methylation-specific polymerase chain reaction, and the effect of demethylation on BTG1 expression was analyzed. BTG1 protein expression in ovarian high-grade serous carcinoma tissue samples was evaluated using immunohistochemistry. BTG1 mRNA and protein expression were reduced in ovarian carcinoma cells. In BTG1-silenced ovarian cancer cells, the BTG1 promoter was highly methylated. Treatment with 5-aza-deoxycytidine significantly elevated BTG1 mRNA and protein expression. Immunostaining demonstrated that BTG1 expression was significantly lower in ovarian carcinoma tissue samples than nonpathological ovaries and fallopian tubes. We demonstrated that BTG1 silencing in ovarian carcinoma occurs through epigenetic repression and is involved in the ovarian carcinogenesis. Our data suggest that BTG1 is a potential therapeutic target for patients with ovarian carcinoma.

  13. Age-Dependent Defects of Regulatory B Cells in Wiskott-Aldrich Syndrome Gene Knockout Mice.

    Directory of Open Access Journals (Sweden)

    Tadafumi Yokoyama

    Full Text Available The Wiskott-Aldrich syndrome (WAS is a rare X-linked primary immunodeficiency characterized by recurrent infections, thrombocytopenia, eczema, and high incidence of malignancy and autoimmunity. The cellular mechanisms underlying autoimmune complications in WAS have been extensively studied; however, they remain incompletely defined. We investigated the characteristics of IL-10-producing CD19+CD1dhighCD5+ B cells (CD1dhighCD5+ Breg obtained from Was gene knockout (WKO mice and found that their numbers were significantly lower in these mice compared to wild type (WT controls. Moreover, we found a significant age-dependent reduction of the percentage of IL-10-expressing cells in WKO CD1dhighCD5+ Breg cells as compared to age-matched WT control mice. CD1dhighCD5+ Breg cells from older WKO mice did not suppress the in vitro production of inflammatory cytokines from activated CD4+ T cells. Interestingly, CD1dhighCD5+ Breg cells from older WKO mice displayed a basal activated phenotype which may prevent normal cellular responses, among which is the expression of IL-10. These defects may contribute to the susceptibility to autoimmunity with age in patients with WAS.

  14. Generation of B cell-deficient pigs by highly efficient CRISPR/Cas9-mediated gene targeting.

    Science.gov (United States)

    Chen, Fengjiao; Wang, Ying; Yuan, Yilin; Zhang, Wei; Ren, Zijian; Jin, Yong; Liu, Xiaorui; Xiong, Qiang; Chen, Qin; Zhang, Manling; Li, Xiaokang; Zhao, Lihua; Li, Ze; Wu, Zhaoqiang; Zhang, Yanfei; Hu, Feifei; Huang, Juan; Li, Rongfeng; Dai, Yifan

    2015-08-20

    Generating B cell-deficient mutant is the first step to produce human antibody repertoires in large animal models. In this study, we applied the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system to target the JH region of the pig IgM heavy chain gene which is crucial for B cell development and differentiation. Transfection of IgM-targeting Cas9 plasmid in primary porcine fetal fibroblasts (PFFs) enabled inducing gene knock out (KO) in up to 53.3% of colonies analyzed, a quarter of which harbored biallelic modification, which was much higher than that of the traditional homologous recombination (HR). With the aid of somatic cell nuclear transfer (SCNT) technology, three piglets with the biallelic IgM heavy chain gene mutation were produced. The piglets showed no antibody-producing B cells which indicated that the biallelic mutation of the IgM heavy chain gene effectively knocked out the function of the IgM and resulted in a B cell-deficient phenotype. Our study suggests that the CRISPR/Cas9 system combined with SCNT technology is an efficient genome-editing approach in pigs. Copyright © 2015 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  15. Immunoglobulin kappa variable region gene selection during early human B cell development in health and systemic lupus erythematosus.

    Science.gov (United States)

    Hehle, Verena; Fraser, Louise D; Tahir, Romeeza; Kipling, David; Wu, Yu-Chang; Lutalo, Pamela M K; Cason, John; Choong, LeeMeng; D'Cruz, David P; Cope, Andrew P; Dunn-Walters, Deborah K; Spencer, Jo

    2015-06-01

    The unique specificity of the B cell receptor is generated by an ordered sequence of gene rearrangement events. Once IGH genes have rearranged, rearrangement at the IGK locus is initiated followed by the IGL locus if functional IGK rearrangement is not achieved. Receptor specificity can subsequently be altered by secondary light chain editing based on the features of the heavy and light chain combination. The final profile of expressed genes is not random and biases in this profile are associated with several autoimmune diseases. However, how and when biases are created is not known. To increase our understanding of the processes of selection and editing of IGK rearrangements, we compared four groups of rearrangements of IGK acquired by next generation sequencing. First, expressed rearrangements of IGK from cDNA of IGK expressing B cells. Second, productive rearrangements of IGK from DNA of the same kappa expressing B cells. Third, non-productive rearrangements of IGK from DNA of IGK and IGL expressing B cells, and fourth productively rearranged IGK from DNA of IGL expressing B cells. The latter group would have been rejected during B cell development in favour of rearrangement at the IGL locus and are therefore selected against. We saw evidence that rearranged IGK segments can be selected at a checkpoint where the decision to rearrange the IGL locus is made. In addition, our data suggest that mechanisms regulating the expression or not of IGK rearrangements may also contribute to repertoire development and also that this latter component of the selection process is defective in SLE. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Gene expression profiling of the response to interferon beta in Epstein-Barr-transformed and primary B cells of patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Rana Khsheibun

    Full Text Available The effects of interferon-beta (IFN-β, one of the key immunotherapies used in multiple sclerosis (MS, on peripheral blood leukocytes and T cells have been extensively studied. B cells are a less abundant leukocyte type, and accordingly less is known about the B cell-specific response to IFN-β. To identify gene expression changes and pathways induced by IFN-β in B cells, we studied the in vitro response of human Epstein Barr-transformed B cells (lymphoblast cell lines-LCLs, and validated our results in primary B cells. LCLs were derived from an MS patient repository. Whole genome expression analysis identified 115 genes that were more than two-fold differentially up-regulated following IFN-β exposure, with over 50 previously unrecognized as IFN-β response genes. Pathways analysis demonstrated that IFN-β affected LCLs in a similar manner to other cell types by activating known IFN-β canonical pathways. Additionally, IFN-β increased the expression of innate immune response genes, while down-regulating many B cell receptor pathway genes and genes involved in adaptive immune responses. Novel response genes identified herein, NEXN, DDX60L, IGFBP4, and HAPLN3, B cell receptor pathway genes, CD79B and SYK, and lymphocyte activation genes, LAG3 and IL27RA, were validated as IFN-β response genes in primary B cells. In this study new IFN-β response genes were identified in B cells, with possible implications to B cell-specific functions. The study's results emphasize the applicability of LCLs for studies of human B cell drug response. The usage of LCLs from patient-based repositories may facilitate future studies of drug response in MS and other immune-mediated disorders with a B cell component.

  17. cDNA-library testing identifies transforming genes cooperating with c-myc in mouse pre-B cells.

    Science.gov (United States)

    Wolf, Inge; Bouquet, Corinne; Melchers, Fritz

    2016-11-01

    While c-myc often contributes to the generation of B cell transformation, its transgenic overexpression alone does not lead to full transformation of B-lineage cells. Synergistically acting second genes must cooperate. Here, we constructed doxycycline-inducible cDNA-libraries from pre-B cell mRNA. These libraries were retrovirally transduced as single copies into single cells and overexpressed in fetal-liver-derived c-myc-overexpressing pre-B cell lines. We scored transformation by survival and/or expansion of differentiating B-lineage cells in vitro and in vivo. Only one double c-myc/cDNA-library-expressing cell line was found in less than 5 × 10 6 library-transduced pre-B cells surviving and expressing a cDNA-library-derived transcript in vitro. This transcript was identified as a shortened form of the Exosc1 gene, encoding the RNA exosome complex component CSL4. Transplantations of double c-myc/Exosc1 short-form- or c-myc/Exosc1 full-length-transgenic cells into Rag1 -/- mice resulted in survival, differentiation to CD19 + CD93 - sIgM + CD5 low/- CD11b + mature B1 cells and, surprisingly, also vigorous expansion in vivo. Strikingly, after transplantations of c-myc/cDNA-library pre-BI cells the frequencies of double-transgenic pre-B cells and their differentiated progeny, expanding in vivo to heterogeneous phenotypes, was at least tenfold higher than in vitro. In a first analysis Ptprcap, Cacybp, Ndufs7, Rpl18a, and Rpl35a were identified. This suggests a strong influence of the host on B-cell transformation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A unified 35-gene signature for both subtype classification and survival prediction in diffuse large B-cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yu-Dong Cai

    Full Text Available Cancer subtype classification and survival prediction both relate directly to patients' specific treatment plans, making them fundamental medical issues. Although the two factors are interrelated learning problems, most studies tackle each separately. In this paper, expression levels of genes are used for both cancer subtype classification and survival prediction. We considered 350 diffuse large B-cell lymphoma (DLBCL subjects, taken from four groups of patients (activated B-cell-like subtype dead, activated B-cell-like subtype alive, germinal center B-cell-like subtype dead, and germinal center B-cell-like subtype alive. As classification features, we used 11,271 gene expression levels of each subject. The features were first ranked by mRMR (Maximum Relevance Minimum Redundancy principle and further selected by IFS (Incremental Feature Selection procedure. Thirty-five gene signatures were selected after the IFS procedure, and the patients were divided into the above mentioned four groups. These four groups were combined in different ways for subtype prediction and survival prediction, specifically, the activated versus the germinal center and the alive versus the dead. Subtype prediction accuracy of the 35-gene signature was 98.6%. We calculated cumulative survival time of high-risk group and low-risk groups by the Kaplan-Meier method. The log-rank test p-value was 5.98e-08. Our methodology provides a way to study subtype classification and survival prediction simultaneously. Our results suggest that for some diseases, especially cancer, subtype classification may be used to predict survival, and, conversely, survival prediction features may shed light on subtype features.

  19. Protein kinase Cθ gene expression is oppositely regulated by GCN5 and EBF1 in immature B cells.

    Science.gov (United States)

    Kikuchi, Hidehiko; Nakayama, Masami; Kuribayashi, Futoshi; Imajoh-Ohmi, Shinobu; Nishitoh, Hideki; Takami, Yasunari; Nakayama, Tatsuo

    2014-05-02

    In this study, we revealed that GCN5 and early B cell factor 1 (EBF1) participate in regulation of protein kinase Cθ (PKCθ) gene expression in an opposite manner in immature B cells. GCN5-deficiency in DT40 caused drastic down-regulation of transcription of PKCθ. In contrast, EBF1-deficiency brought about remarkable up-regulation of that of PKCθ, and re-expression of EBF1 dramatically suppressed transcription of PKCθ. Chromatin immunoprecipitation assay revealed that GCN5 binds to the 5'-flanking region of the chicken PKCθ gene and acetylates histone H3, and EBF1 binds to the 5'-flanking region of the gene surrounding putative EBF1 binding motifs. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  20. CD30 expression defines a novel subgroup of diffuse large B-cell lymphoma with favorable prognosis and distinct gene expression signature

    DEFF Research Database (Denmark)

    Hu, Shimin; Xu-Monette, Zijun Y; Balasubramanyam, Aarthi

    2013-01-01

    ) and progression-free survival (P = .003). The favorable outcome of CD30 expression was maintained in both the germinal center B-cell and activated B-cell subtypes. Gene expression profiling revealed the upregulation of genes encoding negative regulators of nuclear factor κB activation and lymphocyte survival...

  1. Transgenic mice bearing the human c-myc gene activated by an immunoglobulin enhancer: A pre-B-cell lymphoma model

    International Nuclear Information System (INIS)

    Schmidt, E.V.; Pattengale, P.K.; Weir, L.; Leder, P.

    1988-01-01

    Transgenic mice carrying a fusion gene in which the mouse immunoglobulin enhancer has been inserted into an otherwise normal human c-myc gene develop a narrow spectrum of pre-B-cell lymphomas. Tumor occurrence is correlated with expression of the transgene in organs in which large numbers of pre-B cells predominate. These tumors, which arise stochastically, are virtually all lymphoblastic lymphomas of the pre-B-cell type. Evidently the isolated enhancer targets oncogene expression and tumorigenesis to the early B-cell population in preference to more mature B-cell populations. The transgene also confers enhanced in vitro growth properties on nontransformed pre-B cells as observed in bone marrow cultures derived from transgenic animals. These cultured cells represent a population in which the activating function of c-myc can be uncoupled from secondary oncogenic events occurring in vivo

  2. RCSD1-ABL1 Translocation Associated with IKZF1 Gene Deletion in B-Cell Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Shawana Kamran

    2015-01-01

    Full Text Available The RCSD1 gene has recently been identified as a novel gene fusion partner of the ABL1 gene in cases of B-cell Acute Lymphoblastic Leukemia (B-ALL. The RCSD1 gene is located at 1q23 and ABL1 is located at 9q34, so that the RCSD1-ABL1 fusion typically arises through a rare reciprocal translocation t(1;9(q23;q34. Only a small number of RCSD1-ABL1 positive cases of B-ALL have been described in the literature, and the full spectrum of clinical, morphological, immunophenotypic, and molecular features associated with this genetic abnormality has not been defined. We describe extensive genetic characterization of a case of B-ALL with RCSD1-ABL1 fusion, by using conventional cytogenetic analysis, Fluorescence In Situ Hybridization (FISH studies, and Chromosomal Microarray Analysis (CMA. The use of CMA resulted in detection of an approximately 70 kb deletion at 7p12.2, which caused a disruption of the IKZF1 gene. Deletions and mutations of IKZF1 are recurring abnormalities in B-ALL and are associated with a poor prognosis. Our findings highlight the association of the deletion of IKZF1 gene with the t(1;9(q24;q34 and illustrate the importance of comprehensive cytogenetic and molecular evaluation for accurate prediction of prognosis in patients with B-cell ALL.

  3. Transient B cell depletion or improved transgene expression by codon optimization promote tolerance to factor VIII in gene therapy.

    Directory of Open Access Journals (Sweden)

    Brandon K Sack

    Full Text Available The major complication in the treatment of hemophilia A is the development of neutralizing antibodies (inhibitors against factor VIII (FVIII. The current method for eradicating inhibitors, termed immune tolerance induction (ITI, is costly and protracted. Clinical protocols that prevent rather than treat inhibitors are not yet established. Liver-directed gene therapy hopes to achieve long-term correction of the disease while also inducing immune tolerance. We sought to investigate the use of adeno-associated viral (serotype 8 gene transfer to induce tolerance to human B domain deleted FVIII in hemophilia A mice. We administered an AAV8 vector with either human B domain deleted FVIII or a codon-optimized transgene, both under a liver-specific promoter to two strains of hemophilia A mice. Protein therapy or gene therapy was given either alone or in conjunction with anti-CD20 antibody-mediated B cell depletion. Gene therapy with a low-expressing vector resulted in sustained near-therapeutic expression. However, supplementary protein therapy revealed that gene transfer had sensitized mice to hFVIII in a high-responder strain but not in mice of a low-responding strain. This heightened response was ameliorated when gene therapy was delivered with anti-murine CD20 treatment. Transient B cell depletion prevented inhibitor formation in protein therapy, but failed to achieve a sustained hypo-responsiveness. Importantly, use of a codon-optimized hFVIII transgene resulted in sustained therapeutic expression and tolerance without a need for B cell depletion. Therefore, anti-CD20 may be beneficial in preventing vector-induced immune priming to FVIII, but higher levels of liver-restricted expression are preferred for tolerance.

  4. DNMT1 is associated with cell cycle and DNA replication gene sets in diffuse large B-cell lymphoma.

    Science.gov (United States)

    Loo, Suet Kee; Ab Hamid, Suzina Sheikh; Musa, Mustaffa; Wong, Kah Keng

    2018-01-01

    Dysregulation of DNA (cytosine-5)-methyltransferase 1 (DNMT1) is associated with the pathogenesis of various types of cancer. It has been previously shown that DNMT1 is frequently expressed in diffuse large B-cell lymphoma (DLBCL), however its functions remain to be elucidated in the disease. In this study, we gene expression profiled (GEP) shRNA targeting DNMT1(shDNMT1)-treated germinal center B-cell-like DLBCL (GCB-DLBCL)-derived cell line (i.e. HT) compared with non-silencing shRNA (control shRNA)-treated HT cells. Independent gene set enrichment analysis (GSEA) performed using GEPs of shRNA-treated HT cells and primary GCB-DLBCL cases derived from two publicly-available datasets (i.e. GSE10846 and GSE31312) produced three separate lists of enriched gene sets for each gene sets collection from Molecular Signatures Database (MSigDB). Subsequent Venn analysis identified 268, 145 and six consensus gene sets from analyzing gene sets in C2 collection (curated gene sets), C5 sub-collection [gene sets from gene ontology (GO) biological process ontology] and Hallmark collection, respectively to be enriched in positive correlation with DNMT1 expression profiles in shRNA-treated HT cells, GSE10846 and GSE31312 datasets [false discovery rate (FDR) 0.8) with DNMT1 expression and significantly downregulated (log fold-change <-1.35; p<0.05) following DNMT1 silencing in HT cells. These results suggest the involvement of DNMT1 in the activation of cell cycle and DNA replication in DLBCL cells. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Production of recombinant Ig molecules from antigen-selected single B cells and restricted usage of Ig-gene segments by anti-D antibodies

    NARCIS (Netherlands)

    Dohmen, Serge E.; Mulder, Arend; Verhagen, Onno J. H. M.; Eijsink, Chantal; Franke-van Dijk, Marry E. I.; van der Schoot, C. Ellen

    2005-01-01

    The Ig-genes of the heavy chains in anti-D-specific hybridomas and Fab/scFv-fragments selected from phage-display libraries are restricted to a group of closely related genes (IGHV3s genes). We analyzed the Ig-gene repertoire in anti-D-specific B cells of two hyperimmunized donors using a completely

  6. A strategy for full interrogation of prognostic gene expression patterns: exploring the biology of diffuse large B cell lymphoma.

    Science.gov (United States)

    Rimsza, Lisa M; Unger, Joseph M; Tome, Margaret E; Leblanc, Michael L

    2011-01-01

    Gene expression profiling yields quantitative data on gene expression used to create prognostic models that accurately predict patient outcome in diffuse large B cell lymphoma (DLBCL). Often, data are analyzed with genes classified by whether they fall above or below the median expression level. We sought to determine whether examining multiple cut-points might be a more powerful technique to investigate the association of gene expression with outcome. We explored gene expression profiling data using variable cut-point analysis for 36 genes with reported prognostic value in DLBCL. We plotted two-group survival logrank test statistics against corresponding cut-points of the gene expression levels and smooth estimates of the hazard ratio of death versus gene expression levels. To facilitate comparisons we also standardized the expression of each of the genes by the fraction of patients that would be identified by any cut-point. A multiple comparison adjusted permutation p-value identified 3 different patterns of significance: 1) genes with significant cut-point points below the median, whose loss is associated with poor outcome (e.g. HLA-DR); 2) genes with significant cut-points above the median, whose over-expression is associated with poor outcome (e.g. CCND2); and 3) genes with significant cut-points on either side of the median, (e.g. extracellular molecules such as FN1). Variable cut-point analysis with permutation p-value calculation can be used to identify significant genes that would not otherwise be identified with median cut-points and may suggest biological patterns of gene effects.

  7. A strategy for full interrogation of prognostic gene expression patterns: exploring the biology of diffuse large B cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Lisa M Rimsza

    Full Text Available Gene expression profiling yields quantitative data on gene expression used to create prognostic models that accurately predict patient outcome in diffuse large B cell lymphoma (DLBCL. Often, data are analyzed with genes classified by whether they fall above or below the median expression level. We sought to determine whether examining multiple cut-points might be a more powerful technique to investigate the association of gene expression with outcome.We explored gene expression profiling data using variable cut-point analysis for 36 genes with reported prognostic value in DLBCL. We plotted two-group survival logrank test statistics against corresponding cut-points of the gene expression levels and smooth estimates of the hazard ratio of death versus gene expression levels. To facilitate comparisons we also standardized the expression of each of the genes by the fraction of patients that would be identified by any cut-point. A multiple comparison adjusted permutation p-value identified 3 different patterns of significance: 1 genes with significant cut-point points below the median, whose loss is associated with poor outcome (e.g. HLA-DR; 2 genes with significant cut-points above the median, whose over-expression is associated with poor outcome (e.g. CCND2; and 3 genes with significant cut-points on either side of the median, (e.g. extracellular molecules such as FN1.Variable cut-point analysis with permutation p-value calculation can be used to identify significant genes that would not otherwise be identified with median cut-points and may suggest biological patterns of gene effects.

  8. TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma | Office of Cancer Genomics

    Science.gov (United States)

    Recently, the landscape of single base mutations in diffuse large B-cell lymphoma (DLBCL) was described. Here we report the discovery of a gene fusion between TBL1XR1 and TP63, the only recurrent somatic novel gene fusion identified in our analysis of transcriptome data from 96 DLBCL cases. Based on this cohort and a further 157 DLBCL cases analyzed by FISH, the incidence in de novo germinal center B cell-like (GCB) DLBCL is 5% (6 of 115).

  9. New MYC IHC Classifier Integrating Quantitative Architecture Parameters to Predict MYC Gene Translocation in Diffuse Large B-Cell Lymphoma

    Science.gov (United States)

    Dong, Wei-Feng; Canil, Sarah; Lai, Raymond; Morel, Didier; Swanson, Paul E.; Izevbaye, Iyare

    2018-01-01

    A new automated MYC IHC classifier based on bivariate logistic regression is presented. The predictor relies on image analysis developed with the open-source ImageJ platform. From a histologic section immunostained for MYC protein, 2 dimensionless quantitative variables are extracted: (a) relative distance between nuclei positive for MYC IHC based on euclidean minimum spanning tree graph and (b) coefficient of variation of the MYC IHC stain intensity among MYC IHC-positive nuclei. Distance between positive nuclei is suggested to inversely correlate MYC gene rearrangement status, whereas coefficient of variation is suggested to inversely correlate physiological regulation of MYC protein expression. The bivariate classifier was compared with 2 other MYC IHC classifiers (based on percentage of MYC IHC positive nuclei), all tested on 113 lymphomas including mostly diffuse large B-cell lymphomas with known MYC fluorescent in situ hybridization (FISH) status. The bivariate classifier strongly outperformed the “percentage of MYC IHC-positive nuclei” methods to predict MYC+ FISH status with 100% sensitivity (95% confidence interval, 94-100) associated with 80% specificity. The test is rapidly performed and might at a minimum provide primary IHC screening for MYC gene rearrangement status in diffuse large B-cell lymphomas. Furthermore, as this bivariate classifier actually predicts “permanent overexpressed MYC protein status,” it might identify nontranslocation-related chromosomal anomalies missed by FISH. PMID:27093450

  10. Interleukin 10 gene promoter polymorphism and risk of diffuse large B cell lymphoma (DLBCL

    Directory of Open Access Journals (Sweden)

    Roba M. Talaat

    2014-01-01

    Conclusions: Taken together, our findings demonstrated that IL-10 promoter gene polymorphism (−1082 and −819 may not have an influence on the clinical outcome of DLBCL, especially in terms of overall secretion level. Further investigations of other cytokine gene polymorphisms will lead to a better understanding of the disease’s biological background.

  11. PCR-based clonality analysis of B-cell lymphomas in paraffin-embedded tissues: diagnostic value of immunoglobulin kappa and lambda light chain gene rearrangement investigation.

    Science.gov (United States)

    Amara, Khaled; Trimeche, Mounir; Ziadi, Sonia; Sriha, Badreddine; Mokni, Moncef; Korbi, Sadok

    2006-01-01

    Polymerase chain reaction (PCR)-based analysis, employed for detecting immunoglobulin heavy chain (IgH) gene rearrangements, has become a diagnostic tool widely used in the investigation of B-cell lymphomas, but the overall sensitivity of these methods does not exceed 80%, notably in germinal center (GC) and post-GC B-cell origin lymphomas. Many PCR strategies devised for detecting immunoglobulin light chain (IgL) gene rearrangements have been developed to enhance the clonality detection rates. However, the feasibility of these methods in routine clinical diagnosis using paraffin-embedded tissues has not yet been investigated sufficiently. We studied a large series of 108 cases of B-cell lymphomas, as well as 20 reactive lymphoid tissues using degenerate primers to amplify immunoglobulin kappa (Igkappa) and lambda (Iglambda) light chain genes. B-cell clonality was further investigated using semi-nested PCR for IgH gene rearrangements. B-cell clonality was detected in 74%, 56.5%, and 43.5% of cases using IgH, Igkappa, and Iglambda PCR, respectively. By combining these methods, the clonality detection rate increased to 93.5%. Only polyclonal patterns were noted in reactive lymphoid samples. We concluded that in addition to the established methods for IgH analysis, a PCR-based approach for IgL gene rearrangements analysis improves the clonality detection rate in over 90% of B-cell lymphoma cases using routine histological specimens with poor preservation of the genomic DNA.

  12. Perturbation of B Cell Gene Expression Persists in HIV-Infected Children Despite Effective Antiretroviral Therapy and Predicts H1N1 Response.

    Science.gov (United States)

    Cotugno, Nicola; De Armas, Lesley; Pallikkuth, Suresh; Rinaldi, Stefano; Issac, Biju; Cagigi, Alberto; Rossi, Paolo; Palma, Paolo; Pahwa, Savita

    2017-01-01

    Despite effective antiretroviral therapy (ART), HIV-infected individuals with apparently similar clinical and immunological characteristics can vary in responsiveness to vaccinations. However, molecular mechanisms responsible for such impairment, as well as biomarkers able to predict vaccine responsiveness in HIV-infected children, remain unknown. Following the hypothesis that a B cell qualitative impairment persists in HIV-infected children (HIV) despite effective ART and phenotypic B cell immune reconstitution, the aim of the current study was to investigate B cell gene expression of HIV compared to age-matched healthy controls (HCs) and to determine whether distinct gene expression patterns could predict the ability to respond to influenza vaccine. To do so, we analyzed prevaccination transcriptional levels of a 96-gene panel in equal numbers of sort-purified B cell subsets (SPBS) isolated from peripheral blood mononuclear cells using multiplexed RT-PCR. Immune responses to H1N1 antigen were determined by hemaglutination inhibition and memory B cell ELISpot assays following trivalent-inactivated influenza vaccination (TIV) for all study participants. Although there were no differences in terms of cell frequencies of SPBS between HIV and HC, the groups were distinguishable based upon gene expression analyses. Indeed, a 28-gene signature, characterized by higher expression of genes involved in the inflammatory response and immune activation was observed in activated memory B cells (CD27 + CD21 - ) from HIV when compared to HC despite long-term viral control (>24 months). Further analysis, taking into account H1N1 responses after TIV in HIV participants, revealed that a 25-gene signature in resting memory (RM) B cells (CD27 + CD21 + ) was able to distinguish vaccine responders from non-responders (NR). In fact, prevaccination RM B cells of responders showed a higher expression of gene sets involved in B cell adaptive immune responses ( APRIL, BTK, BLIMP1 ) and

  13. Perturbation of B Cell Gene Expression Persists in HIV-Infected Children Despite Effective Antiretroviral Therapy and Predicts H1N1 Response

    Directory of Open Access Journals (Sweden)

    Nicola Cotugno

    2017-09-01

    Full Text Available Despite effective antiretroviral therapy (ART, HIV-infected individuals with apparently similar clinical and immunological characteristics can vary in responsiveness to vaccinations. However, molecular mechanisms responsible for such impairment, as well as biomarkers able to predict vaccine responsiveness in HIV-infected children, remain unknown. Following the hypothesis that a B cell qualitative impairment persists in HIV-infected children (HIV despite effective ART and phenotypic B cell immune reconstitution, the aim of the current study was to investigate B cell gene expression of HIV compared to age-matched healthy controls (HCs and to determine whether distinct gene expression patterns could predict the ability to respond to influenza vaccine. To do so, we analyzed prevaccination transcriptional levels of a 96-gene panel in equal numbers of sort-purified B cell subsets (SPBS isolated from peripheral blood mononuclear cells using multiplexed RT-PCR. Immune responses to H1N1 antigen were determined by hemaglutination inhibition and memory B cell ELISpot assays following trivalent-inactivated influenza vaccination (TIV for all study participants. Although there were no differences in terms of cell frequencies of SPBS between HIV and HC, the groups were distinguishable based upon gene expression analyses. Indeed, a 28-gene signature, characterized by higher expression of genes involved in the inflammatory response and immune activation was observed in activated memory B cells (CD27+CD21− from HIV when compared to HC despite long-term viral control (>24 months. Further analysis, taking into account H1N1 responses after TIV in HIV participants, revealed that a 25-gene signature in resting memory (RM B cells (CD27+CD21+ was able to distinguish vaccine responders from non-responders (NR. In fact, prevaccination RM B cells of responders showed a higher expression of gene sets involved in B cell adaptive immune responses (APRIL, BTK, BLIMP1 and

  14. Radiosensitive SCID patients with Artemis gene mutations show a complete B-cell differentiation arrest at the pre-B-cell receptor checkpoint in bone marrow.

    NARCIS (Netherlands)

    Noordzij, J.G.; Verkaik, N.S.; Burg, M.E.L. van der; Veelen, L.R. van; Bruin-Versteeg, S. de; Wiegant, W.; Vossen, J.M.J.J.; Weemaes, C.M.R.; Groot, R. de; Zdzienicka, M.Z.; Gent, D.C. van; Dongen, J.J.M. van

    2003-01-01

    Severe combined immunodeficiency disease (SCID) can be immunologically classified by the absence or presence of T, B, and natural killer (NK) cells. About 30% of T(-)B(-)NK(+) SCID patients carry mutations in the recombination activating genes (RAG). Some T(-)B(-)NK(+) SCID patients without RAG gene

  15. Prediction of Gene Activity in Early B Cell Development Based on an Integrative Multi-Omics Analysis.

    Science.gov (United States)

    Heydarian, Mohammad; Luperchio, Teresa Romeo; Cutler, Jevon; Mitchell, Christopher J; Kim, Min-Sik; Pandey, Akhilesh; Sollner-Webb, Barbara; Reddy, Karen

    2014-02-17

    An increasingly common method for predicting gene activity is genome-wide chromatin immuno-precipitation of 'active' chromatin modifications followed by massively parallel sequencing (ChIP-seq). In order to understand better the relationship between developmentally regulated chromatin landscapes and regulation of early B cell development, we determined how differentially active promoter regions were able to predict relative RNA and protein levels at the pre-pro-B and pro-B stages. Herein, we describe a novel ChIP-seq quantification method (cRPKM) to identify active promoters and a multi-omics approach that compares promoter chromatin status with ongoing active transcription (GRO-seq), steady state mRNA (RNA-seq), inferred mRNA stability, and relative proteome abundance measurements (iTRAQ). We demonstrate that active chromatin modifications at promoters are good indicators of transcription and steady state mRNA levels. Moreover, we found that promoters with active chromatin modifications exclusively in one of these cell states frequently predicted the differential abundance of proteins. However, we found that many genes whose promoters have non-differential but active chromatin modifications also displayed changes in abundance of their cognate proteins. As expected, this large class of developmentally and differentially regulated proteins that was uncoupled from chromatin status used mostly post-transcriptional mechanisms. Strikingly, the most differentially abundant protein in our B-cell development system, 2410004B18Rik, was regulated by a post-transcriptional mechanism, which further analyses indicated was mediated by a micro-RNA. These data highlight how this integrated multi-omics data set can be a useful resource in uncovering regulatory mechanisms. This data can be accessed at: https://usegalaxy.org/u/thereddylab/p/prediction-of-gene-activity-based-on-an-integrative-multi-omics-analysis.

  16. Comparative RNA-Seq and microarray analysis of gene expression changes in B-cell lymphomas of Canis familiaris.

    Directory of Open Access Journals (Sweden)

    Marie Mooney

    Full Text Available Comparative oncology is a developing research discipline that is being used to assist our understanding of human neoplastic diseases. Companion canines are a preferred animal oncology model due to spontaneous tumor development and similarity to human disease at the pathophysiological level. We use a paired RNA sequencing (RNA-Seq/microarray analysis of a set of four normal canine lymph nodes and ten canine lymphoma fine needle aspirates to identify technical biases and variation between the technologies and convergence on biological disease pathways. Surrogate Variable Analysis (SVA provides a formal multivariate analysis of the combined RNA-Seq/microarray data set. Applying SVA to the data allows us to decompose variation into contributions associated with transcript abundance, differences between the technology, and latent variation within each technology. A substantial and highly statistically significant component of the variation reflects transcript abundance, and RNA-Seq appeared more sensitive for detection of transcripts expressed at low levels. Latent random variation among RNA-Seq samples is also distinct in character from that impacting microarray samples. In particular, we observed variation between RNA-Seq samples that reflects transcript GC content. Platform-independent variable decomposition without a priori knowledge of the sources of variation using SVA represents a generalizable method for accomplishing cross-platform data analysis. We identified genes differentially expressed between normal lymph nodes of disease free dogs and a subset of the diseased dogs diagnosed with B-cell lymphoma using each technology. There is statistically significant overlap between the RNA-Seq and microarray sets of differentially expressed genes. Analysis of overlapping genes in the context of biological systems suggests elevated expression and activity of PI3K signaling in B-cell lymphoma biopsies compared with normal biopsies, consistent with

  17. A B-Cell Gene Signature Correlates With the Extent of Gluten-Induced Intestinal Injury in Celiac DiseaseSummary

    Directory of Open Access Journals (Sweden)

    Mitchell E. Garber

    2017-07-01

    Full Text Available Background & Aims: Celiac disease (CeD provides an opportunity to study autoimmunity and the transition in immune cells as dietary gluten induces small intestinal lesions. Methods: Seventy-three celiac disease patients on a long-term, gluten-free diet ingested a known amount of gluten daily for 6 weeks. A peripheral blood sample and intestinal biopsy specimens were taken before and 6 weeks after initiating the gluten challenge. Biopsy results were reported on a continuous numeric scale that measured the villus-height–to–crypt-depth ratio to quantify gluten-induced intestinal injury. Pooled B and T cells were isolated from whole blood, and RNA was analyzed by DNA microarray looking for changes in peripheral B- and T-cell gene expression that correlated with changes in villus height to crypt depth, as patients maintained a relatively healthy intestinal mucosa or deteriorated in the face of a gluten challenge. Results: Gluten-dependent intestinal damage from baseline to 6 weeks varied widely across all patients, ranging from no change to extensive damage. Genes differentially expressed in B cells correlated strongly with the extent of intestinal damage. A relative increase in B-cell gene expression correlated with a lack of sensitivity to gluten whereas their relative decrease correlated with gluten-induced mucosal injury. A core B-cell gene module, representing a subset of B-cell genes analyzed, accounted for the correlation with intestinal injury. Conclusions: Genes comprising the core B-cell module showed a net increase in expression from baseline to 6 weeks in patients with little to no intestinal damage, suggesting that these individuals may have mounted a B-cell immune response to maintain mucosal homeostasis and circumvent inflammation. DNA microarray data were deposited at the GEO repository (accession number: GSE87629; available: https://www.ncbi.nlm.nih.gov/geo/. Keywords: Oral Tolerance, Mucosal Immunity, Autoimmunity

  18. The impact of trisomy 12, retinoblastoma gene and P53 in prognosis of B-cell chronic lymphocytic leukemia.

    Science.gov (United States)

    AbdelSalam, M; El Sissy, A; Samra, M A; Ibrahim, S; El Markaby, D; Gadallah, F

    2008-06-01

    Routine cytogenetic analysis frequently fails to identify an abnormal clone in B-cell lymphocytic leukaemia (B-CLL) due to poor response to mitogen stimulation. Fluorescence in situ hybridization (FISH) suggest that chromosomal abnormalities occur more frequently, most commonly trisomy 12, retinoblastoma gene deletion (Rb1 gene) and P53 gene deletion. 30 patients with B-CLL were enrolled in the trial from two centers in Cairo, Egypt during the period May 2000 to January 2002. Karyotyping and FISH assessment for possible chromosomal abnormalities (trisomy 12, Rb1 gene and P53 gene) were done at initial diagnosis. Results of cytogenetic abnormalities were correlated with clinical picture and survival. The median age was 57.4 years (range 40-75). Karyotyping technique showed that no metaphase could be detected in 30%, metaphase with normal karyotyping was observed in 63% and cytogenetic abnormalities were detected in two cases (one trisomy 12 and one deletion in chromosome 13). FISH examination of interphase and metaphase nuclei revealed cytogenetic abnormalities in 15 cases (50%), trisomy 12 in 9 (30%), Rb1 gene deletion in 5 (17%) and P53 gene deletion in 3. At diagnosis, patients with trisomy 12 were significantly associated with advanced stage and absolute lymphocyte count of >or=30,000/mm(3). Univariate analysis showed that absolute lymphocyte count >or=30,000/mm(3) (p=0.004) and trisomy 12 (p=0.024) were associated with poor progression free survival. Interphase and metaphase FISH studies improve the cytogenetic diagnosis of chromosomal abnormalities in B-CLL. Lymphocytosis and trisomy 12 may be a good indicator of poor prognosis.

  19. Application of HSVtk suicide gene to X-SCID gene therapy: Ganciclovir treatment offsets gene corrected X-SCID B cells

    International Nuclear Information System (INIS)

    Uchiyama, Toru; Kumaki, Satoru; Ishikawa, Yoshinori; Onodera, Masafumi; Sato, Miki; Du, Wei; Sasahara, Yoji; Tanaka, Nobuyuki; Sugamura, Kazuo; Tsuchiya, Shigeru

    2006-01-01

    Recently, a serious adverse effect of uncontrolled clonal T cell proliferation due to insertional mutagenesis of retroviral vector was reported in X-SCID gene therapy clinical trial. To offset the side effect, we have incorporated a suicide gene into therapeutic retroviral vector for selective elimination of transduced cells. In this study, B-cell lines from two X-SCID patients were transduced with bicistronic retroviral vector carrying human γc chain cDNA and Herpes simplex virus thymidine kinase gene. After confirmation of functional reconstitution of the γc chain, the cells were treated with ganciclovir (GCV). The γc chain positive cells were eliminated under low concentration without cytotoxicity on untransduced cells and have not reappeared at least for 5 months. Furthermore, the γc chain transduced cells were still sensitive to GCV after five months. These results demonstrated the efficacy of the suicide gene therapy although further in vivo studies are required to assess feasibility of this approach in clinical trial

  20. Clinical Impact of TP53 Gene Mutations in Diffuse Large B-Cell Lymphoma (DLBCL)

    DEFF Research Database (Denmark)

    Young, Ken H; Patten, Nancy; Truong, Sim

    2009-01-01

    Mutations of the TP53 tumor suppressor gene are associated with a poor clinical outcome in DLBCL patients treated with CHOP. The impact of TP53 mutations on clinical outcome of DLBCL patients treated with Rituxan-CHOP has not been comprehensively analyzed. The purpose of this study was to analyze......, compared to 77% for those with wt-TP53. However, the clinical outcome and treatment response to the Rituxan-CHOP varied in patients with mutations in different regions of the DNA-binding domains. Patients with mutations in the DNA minor binding groove motif (Loop L3, 17% of all mutations) had significantly...

  1. Radiosensitive SCID patients with Artemis gene mutations show a complete B-cell differentiation arrest at the pre-B-cell receptor checkpoint in bone marrow

    NARCIS (Netherlands)

    J.G. Noordzij; M.Z. Zdzienicka (Malgorzata); J.J.M. van Dongen (Jacques); D.C. van Gent (Dik); N.S. Verkaik (Nicole); M. van der Burg (Mirjam); L.R. van Veelen (Lieneke); S. de Bruin-Versteeg (Sandra); W. Wiegant; J.M.J.J. Vossen; R. de Groot (Ronald); C.M.R. Weemaes (Corry)

    2003-01-01

    textabstractSevere combined immunodeficiency disease (SCID) can be immunologically classified by the absence or presence of T, B, and natural killer (NK) cells. About 30% of T(-)B(-)NK(+) SCID patients carry mutations in the recombination activating genes (RAG). Some

  2. Pretransplant mobilization with granulocyte colony-stimulating factor improves b-cell reconstitution by lentiviral vector gene therapy in SCID-X1 mice

    NARCIS (Netherlands)

    M.W. Huston (Marshall W.); A.R.A. Riegman (Adriaan R.A.); R.M.A. Yadak (Rana); Y.M. van Helsdingen (Yvette); H. De Boer (Helen); N.P. van Til (Niek); G. Wagemaker (Gerard)

    2014-01-01

    textabstractHematopoietic stem cell (HSC) gene therapy is a demonstrated effective treatment for X-linked severe combined immunodeficiency (SCID-X1), but B-cell reconstitution and function has been deficient in many of the gene therapy treated patients. Cytoreductive preconditioning is known to

  3. Site-specific expression of Polycomb-group genes encoding the HPC-HPH complex in clinically defined primary nodal and cutaneous large B cells lymphomas

    NARCIS (Netherlands)

    Raaphorst, F.M.; Vermeer, M.; Fieret, E.; Blokzijl, T.; Dukers, N.H.T.M.; Sewalt, R.G.A.B.; Otte, A.P.; Willemze, R.; Meijer, C.J.L.M.

    2004-01-01

    Polycomb-group (PcG) genes preserve cell identity by gene silencing, and contribute to regulation of lymphopoiesis and malignant transformation. We show that primary nodal large B-cell lymphomas (LBCLs), and secondary cutaneous deposits from such lymphomas, abnormally express the BMI-1, RING1, and

  4. MYC Gene Rearrangements Are Closely Associated with Poor Survival of Diffuse Large B Cell Lymphoma with Hepatitis B Virus Infection

    Directory of Open Access Journals (Sweden)

    Zhihe Liu

    2017-01-01

    Full Text Available The aim of this study was to identify clinical adverse prognostic factors affecting overall survival (OS of diffuse large B cell (DLBCL patients with hepatitis B virus (HBV infection. In this study, 30 DLBCL patients with HBV infection and 51 DLBCL patients with HBV-free were reviewed retrospectively. As of July 2016, the median follow-up period was 26.4 months (3.0~65.0 months. The median OS of patients in HBV infection group was 38.6 months, while that of patients in HBV-free group was not reached (P=0.042; the median progression-free survival (PFS of patients in HBV infection group was worse than that in HBV-free group, 18.5 months and 38.5 months (P=0.118, respectively. The rate of MYC and BCL2 gene rearrangements in HBV infection group was significantly higher than that in HBV-free group, 20.0% versus 3.9% (P=0.019 and 23.3% versus 5.9% (P=0.021, respectively. Multivariable analysis indicated that IPI (P=0.002, chemotherapy regimens (P=0.017, and MYC gene rearrangements (P=0.004 were independent adverse prognostic factors for all DLBCL patients in this study. Results demonstrated that the poor survival of DLBCL patients with HBV infection was closely involved in chemotherapy regimens, IPI, and MYC gene rearrangements.

  5. Quantitation of multiple myeloma oncogene 1/interferon-regulatory factor 4 gene expression in malignant B-cell proliferations and normal leukocytes.

    Science.gov (United States)

    Yamada, M; Asanuma, K; Kobayashi, D; Moriai, R; Yajima, T; Yagihashi, A; Yamamori, S; Watanabe, N

    2001-01-01

    We studied multiple myeloma oncogene 1/interferon-regulatory factor 4 (MUM1/IRF4) mRNA expression in various malignant human hematopoietic cell lines and normal leukocyte fractions. A quantitative reverse transcription-polymerase chain reaction was used to assess expression and chromosomes were examined for anomalies by fluorescent in situ hybridization. Among 12 cell lines examined, mRNA transcripts were expressed only in B-lymphoblastic and myeloma cell lines. Myeloma cells and malignant cell lines derived from mature B cells expressed more transcript than cell lines derived from immature B cells. Transcript levels, however, showed no association with chromosomal translocations. Expression in B-cell fractions from healthy donors was much less than in the malignant cells. In addition, MUM1/IRF4 mRNA expressed in samples from patients with acute lymphoblastic leukemia derived from B cells but not T cells. Our results suggested that MUM1/IRF4 gene expression is related to stage of differentiation of malignant B cells and they indicated the possibility that the quantitative analysis of MUM1/IRF4 gene is a useful tool for detection of malignant B-cell proliferations in clinical laboratory tests.

  6. A mouse variable gene fragment binds to DNA independently of the BCR context: a possible role for immature B-cell repertoire establishment.

    Directory of Open Access Journals (Sweden)

    Andrea Queiroz Maranhão

    Full Text Available B-cell maturation occurs in several steps and requires constant stimulus for its continuing development. From the emergence of the pre-B-cell receptor, signal transduction stimulates and supports B-cell development. Current viewpoints indicate that both positive selection pressure for autoantigens and tonic signaling constitutively stimulate B-cell maturation. In this work, we tested for the presence of a putative DNA binding site in a variable gene segment in a germline configuration, independently of VDJ recombination. After a survey of the public antibody databases, we chose a single mouse heavy variable gene segment that is highly represented in anti-nucleic acid antibodies and tested it for ssDNA binding. A phage display approach was used to search for intrinsic binding to oligo deoxythymidine. The results revealed that binding to an antigen can be influenced by the use of a specific DNA binding V[Formula: see text] gene segment. Our data support the idea that some variable genes have intrinsic reactivity towards specific types of endogenous autoantigens, and this property may contribute to the establishment of the immature B-cell repertoire.

  7. Tracking Differential Gene Expression in MRL/MpJ Versus C57BL/6 Anergic B Cells: Molecular Markers of Autoimmunity

    Directory of Open Access Journals (Sweden)

    Amy G. Clark

    2008-01-01

    Full Text Available Background: Anergy is a key mechanism controlling expression of autoreactive B cells and a major site for failed regulation in autoimmune diseases. Yet the molecular basis for this differentiated cell state remains poorly understood. The current lack of well-characterized surface or molecular markers hinders the isolation of anergic cells for further study. Global gene profiling recently identified transcripts whose expression differentiates anergic from naïve B cells in model mouse systems. The objective of the current study was to evaluate the molecular and cellular processes that differentiate anergic cells that develop in the healthy C57BL/6 (B6 milieu from those that develop in the autoimmune-prone MRL/MpJ (MRL background. This approach takes advantage of B6 and MRL mice bearing an anti-laminin Ig transgene with a well characterized anergic B cell phenotype.Results: Global gene expression was evaluated in purified transgenic B cells using Operon version 3.0 oligonucleotide microarray assaying 31,000 oligoprobes. Genes with a 2-fold expression difference in B6 as compared to MRL anergic B cells were identified. Expression of selected genes was confirmed using quantitative RT-PCR. This approach identified 43 probes corresponding to 37 characterized genes, including Ptpn22, CD74, Birc1f/Naip, and Ctla4, as differentially expressed in anergic B cells in the two strains. Gene Ontology classification identified differentiation, cell cycle, proliferation, development, apoptosis, and cell death as prominently represented ontology groups. Ingenuity Pathway Analysis identified two major networks incorporating 27 qualifying genes. Network 1 centers on beta-estradiol and TP53, and Network 2 encompasses RB1, p38 MAPK, and NFkB cell growth, proliferation, and cell cycle signaling pathways.Conclusion: Using microarray analysis we identified 37 characterized genes and two functional pathways engaged in maintenance of B cell anergy for which expression is

  8. Concurrent epigenetic silencing of wnt/β-catenin pathway inhibitor genes in B cell chronic lymphocytic leukaemia

    International Nuclear Information System (INIS)

    Moskalev, Evgeny A; Pötz, Oliver; Joos, Thomas O; Hoheisel, Jörg D; Luckert, Katrin; Vorobjev, Ivan A; Mastitsky, Sergey E; Gladkikh, Aleena A; Stephan, Achim; Schrenk, Marita; Kaplanov, Kamil D; Kalashnikova, Olga B

    2012-01-01

    The Wnt/β-catenin signalling is aberrantly activated in primary B cell chronic lymphocytic leukaemia (CLL). Epigenetic silencing of pathway inhibitor genes may be a mechanism for its activation. In this study, we investigated systematically and quantitatively the methylation status of 12 Wnt/β-catenin pathway inhibitor genes – CDH1, DACT1, DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 and WIF1 – in the cell lines EHEB and MEC-1 as well as patient samples. Quantification of DNA methylation was performed by means of bisulphite pyrosequencing and confirmed by bisulphite Sanger sequencing. Gene expression was analysed by qPCR using GAPDH as internal control. E-cadherin and β-catenin protein quantification was carried out by microsphere-based immunoassays. Methylation differences observed between the patient and control groups were tested using generalised least squares models. For 10 genes, a higher methylation level was observed in tumour material. Only DKK4 exhibited similarly high methylation levels in both tumour and normal specimens, while DACT1 was always essentially unmethylated. However, also for these inhibitors, treatment of cells with the demethylating agent 5-aza-2´-deoxycytidine resulted in an induction of their expression, as shown by quantitative PCR, suggesting an indirect epigenetic control of activity. While the degree of demethylation and its transcriptional consequences differed between the genes, there was an overall high correlation of demethylation and increased activity. Protein expression studies revealed that no constitutive Wnt/β-catenin signalling occurred in the cell lines, which is in discrepancy with results from primary CLL. However, treatment with 5-aza-2´-deoxycytidine caused accumulation of β-catenin. Simultaneously, E-cadherin expression was strongly induced, leading to the formation of a complex with β-catenin and thus demonstrating its epigenetically regulated inhibition effect. The results suggest an

  9. Diffuse aggressive B-cell lymphomas of the gastrointestinal tract. An immunophenotypic and gene rearrangement analysis of 22 cases

    NARCIS (Netherlands)

    van Krieken, J. H.; Medeiros, L. J.; Pals, S. T.; Raffeld, M.; Kluin, P. M.

    1992-01-01

    Twenty-two diffuse aggressive B-cell lymphomas of the gastrointestinal tract were studied using light microscopic examination, immunohistochemical methods, and Southern blot analysis. The results suggest that diffuse aggressive B-cell gastrointestinal tract lymphomas may be divided into two groups:

  10. Structural profiles of TP53 gene mutations predict clinical outcome in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Young, Ken H; Leroy, Karen; Møller, Michael Boe

    2008-01-01

    The purpose of this study is to correlate the presence of TP53 gene mutations with the clinical outcome of a cohort of patients with diffuse large B-cell lymphoma (DLBCL) assembled from 12 medical centers. TP53 mutations were identified in 102 of 477 patients and the overall survival (OS......) of patients with TP53 mutations was significantly worse than those with wild-type TP53 (p=0.0006). However, subsets of TP53 mutations were found to have different effects on OS. Mutations in the TP53 DNA binding domains were the strongest predictors of poor OS (p=0.0003). Mutations in the Loop......-Sheet-Helix and Loop-L3 were associated with significantly decreased OS (p=0.002), but OS was not significantly affected by mutations in Loop-L2. A subset of missense mutations (His(158), His(175), Ser(245), Gln(248), His(273), Arg(280) and Arg(282)) in the DNA binding domains had the worst prognosis. Multivariate...

  11. Applied the additive hazard model to predict the survival time of patient with diffuse large B- cell lymphoma and determine the effective genes, using microarray data

    Directory of Open Access Journals (Sweden)

    Arefa Jafarzadeh Kohneloo

    2015-09-01

    Full Text Available Background: Recent studies have shown that effective genes on survival time of cancer patients play an important role as a risk factor or preventive factor. Present study was designed to determine effective genes on survival time for diffuse large B-cell lymphoma patients and predict the survival time using these selected genes. Materials & Methods: Present study is a cohort study was conducted on 40 patients with diffuse large B-cell lymphoma. For these patients, 2042 gene expression was measured. In order to predict the survival time, the composition of the semi-parametric additive survival model with two gene selection methods elastic net and lasso were used. Two methods were evaluated by plotting area under the ROC curve over time and calculating the integral of this curve. Results: Based on our findings, the elastic net method identified 10 genes, and Lasso-Cox method identified 7 genes. GENE3325X increased the survival time (P=0.006, Whereas GENE3980X and GENE377X reduced the survival time (P=0.004. These three genes were selected as important genes in both methods. Conclusion: This study showed that the elastic net method outperformed the common Lasso method in terms of predictive power. Moreover, apply the additive model instead Cox regression and using microarray data is usable way for predict the survival time of patients.

  12. Pretransplant mobilization with granulocyte colony-stimulating factor improves B-cell reconstitution by lentiviral vector gene therapy in SCID-X1 mice.

    Science.gov (United States)

    Huston, Marshall W; Riegman, Adriaan R A; Yadak, Rana; van Helsdingen, Yvette; de Boer, Helen; van Til, Niek P; Wagemaker, Gerard

    2014-10-01

    Hematopoietic stem cell (HSC) gene therapy is a demonstrated effective treatment for X-linked severe combined immunodeficiency (SCID-X1), but B-cell reconstitution and function has been deficient in many of the gene therapy treated patients. Cytoreductive preconditioning is known to improve HSC engraftment, but in general it is not considered for SCID-X1 since the poor health of most of these patients at diagnosis and the risk of toxicity preclude the conditioning used in standard bone marrow stem cell transplantation. We hypothesized that mobilization of HSC by granulocyte colony-stimulating factor (G-CSF) should create temporary space in bone marrow niches to improve engraftment and thereby B-cell reconstitution. In the present pilot study supplementing our earlier preclinical evaluation (Huston et al., 2011), Il2rg(-/-) mice pretreated with G-CSF were transplanted with wild-type lineage negative (Lin(-)) cells or Il2rg(-/-) Lin(-) cells transduced with therapeutic IL2RG lentiviral vectors. Mice were monitored for reconstitution of lymphocyte populations, level of donor cell chimerism, and antibody responses as compared to 2 Gy total body irradiation (TBI), previously found effective in promoting B-cell reconstitution. The results demonstrate that G-CSF promotes B-cell reconstitution similar to low-dose TBI and provides proof of principle for an alternative approach to improve efficacy of gene therapy in SCID patients without adverse effects associated with cytoreductive conditioning.

  13. [Impact of PRDM1 gene inactivation on C-MYC regulation in diffuse large B-cell lymphoma].

    Science.gov (United States)

    Zhang, X Y; Ma, Z P; Cui, W L; Pang, X L; Chen, R; Wang, L; Zhang, W; Li, X X

    2018-01-08

    Objective: To investigate the role of PRDM1 gene inactivaion in the regulation of C-MYC in diffuse large B-cell lymphoma (DLBCL), and to explore the correlation of its immunophenotype and prognosis. Methods: 100 cases paraffin-embedded DLBCL tissues were collected from January 2009 to December 2015 at the First Affiliated Hospital of Xinjiang Medical University along with 20 cases of reactive proliferative lymph nodes as control. Immunohistochemical methods were used to detect the expression of CD20, CD10, MUM1, Ki-67, bcl-6, PRDM1/Blimp1, C-MYC and PAX5 protein. The tumors were classified into two subtypes according to Hans classification.The expression of PRDM1 and C-MYC gene in tumor group and control group was detected by reverse transcription PCR (RT-PCR) and the relationship between PRDM1 and C-MYC gene was analyzed.OCI-LY1 (GCB subtype) and OCI-LY3 (non-GCB subtype) cell lines were transfected with small interfering RNA by cationic liposome reagent transfection, and the expression of C-MYC in the transfected cell lines was detected by RT-PCR and Western blot. The Kaplan-Meier method was used to analyze the prognostic significance of PRDM1/Blimp1 and C-MYC at protein and mRNA levels. Results: There were 27 cases of GCB subtype and 73 cases of non-GCB subtype according to Hans classification. The positive expression of Blimp1 in DLBCL group and proliferative lymph nodes in control group was seen in 26(26.0%) and 20 cases(100%), respectively. There were 58 cases with high expression of PRDM1 at mRNA level, including 22 cases of GCB subtype and 36 cases non-GCB subtype, and the difference was statistically significant ( P =0.004). There were differences in PRDM1 gene expression between the two immunological subtypes, serum lactate dehydrogenase (serum LDH) level, presence of B symptoms, tumor primary sites and other clinical pathological parameters, while C-MYC expression was different in gender, IPI score, and serum LDH levels. Upon PRDM1/Blimp1 gene silencing

  14. Gene delivery in malignant B cells using the combination of lentiviruses conjugated to anti-transferrin receptor antibodies and an immunoglobulin promoter.

    Science.gov (United States)

    Leoh, Lai Sum; Morizono, Kouki; Kershaw, Kathleen M; Chen, Irvin S Y; Penichet, Manuel L; Daniels-Wells, Tracy R

    2014-01-01

    We previously developed an antibody-avidin fusion protein (ch128.1Av) specific for the human transferrin receptor 1 (TfR1; CD71) to be used as a delivery vector for cancer therapy and showed that ch128.1Av delivers the biotinylated plant toxin saporin-6 into malignant B cells. However, as a result of widespread expression of TfR1, delivery of the toxin to normal cells is a concern. Therefore, we explored the potential of a dual targeted lentiviral-mediated gene therapy strategy to restrict gene expression to malignant B cells. Targeting occurs through the use of ch128.1Av or its parental antibody without avidin (ch128.1) and through transcriptional regulation using an immunoglobulin promoter. Flow cytometry was used to detect the expression of enhanced green fluorescent protein (EGFP) in a panel of cell lines. Cell viability after specific delivery of the therapeutic gene FCU1, a chimeric enzyme consisting of cytosine deaminase genetically fused to uracil phosphoribosyltransferse that converts the 5-fluorocytosine (5-FC) prodrug into toxic metabolites, was monitored using the MTS or WST-1 viability assay. We found that EGFP was specifically expressed in a panel of human malignant B-cell lines, but not in human malignant T-cell lines. EGFP expression was observed in all cell lines when a ubiquitous promoter was used. Furthermore, we show the decrease of cell viability in malignant plasma cells in the presence of 5-FC and the FCU1 gene. The present study demonstrates that gene expression can be restricted to malignant B cells and suggests that this dual targeted gene therapy strategy may help to circumvent the potential side effects of certain TfR1-targeted protein delivery approaches. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Differential gene expression in chicken primary B cells infected ex vivo with attenuated and very virulent strains of infectious bursal disease virus (IBDV).

    Science.gov (United States)

    Dulwich, Katherine L; Giotis, Efstathios S; Gray, Alice; Nair, Venugopal; Skinner, Michael A; Broadbent, Andrew J

    2017-12-01

    Infectious bursal disease virus (IBDV) belongs to the family Birnaviridae and is economically important to the poultry industry worldwide. IBDV infects B cells in the bursa of Fabricius (BF), causing immunosuppression and morbidity in young chickens. In addition to strains that cause classical Gumboro disease, the so-called 'very virulent' (vv) strain, also in circulation, causes more severe disease and increased mortality. IBDV has traditionally been controlled through the use of live attenuated vaccines, with attenuation resulting from serial passage in non-lymphoid cells. However, the factors that contribute to the vv or attenuated phenotypes are poorly understood. In order to address this, we aimed to investigate host cell-IBDV interactions using a recently described chicken primary B-cell model, where chicken B cells are harvested from the BF and cultured ex vivo in the presence of chicken CD40L. We demonstrated that these cells could support the replication of IBDV when infected ex vivo in the laboratory. Furthermore, we evaluated the gene expression profiles of B cells infected with an attenuated strain (D78) and a very virulent strain (UK661) by microarray. We found that key genes involved in B-cell activation and signalling (TNFSF13B, CD72 and GRAP) were down-regulated following infection relative to mock, which we speculate could contribute to IBDV-mediated immunosuppression. Moreover, cells responded to infection by expressing antiviral type I IFNs and IFN-stimulated genes, but the induction was far less pronounced upon infection with UK661, which we speculate could contribute to its virulence.

  16. Subtype assignment of CLL based on B-cell subset associated gene signatures from normal bone marrow – A proof of concept study

    DEFF Research Database (Denmark)

    Nørgaard, Caroline Holm; Jakobsen, Lasse Hjort; Gentles, Andrew J.

    2018-01-01

    . Our hypothesis is that by segregating CLL according to BAGS, we can identify subtypes with prognostic implications in support of pathogenetic value of BAGS. Microarray-based gene-expression samples from eight independent CLL cohorts (1,024 untreated patients) were BAGS-stratified into pre-BI, pre...... subtype resistance towards rituximab and cyclophosphamide varied for rituximab, whereas all subtypes were sensitive to cyclophosphamide. This study supports our hypothesis that BAGS-subtyping may be of tangible prognostic and pathogenetic value for CLL patients.......Diagnostic and prognostic evaluation of chronic lymphocytic leukemia (CLL) involves blood cell counts, immunophenotyping, IgVH mutation status, and cytogenetic analyses. We generated B-cell associated gene-signatures (BAGS) based on six naturally occurring B-cell subsets within normal bone marrow...

  17. Rearrangements of MYC gene facilitate risk stratification in diffuse large B-cell lymphoma patients treated with rituximab-CHOP

    DEFF Research Database (Denmark)

    Tzankov, Alexandar; Xu-Monette, Zijun Y; Gerhard, Marc

    2014-01-01

    In order to address the debatable prognostic role of MYC rearrangements in diffuse large B-cell lymphoma patients treated with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone, we evaluated MYC rearrangements by fluorescence in situ hybridization in 563 cases using br...

  18. Tet2 facilitates the derepression of myeloid target genes during CEBPα-induced transdifferentiation of pre-B cells

    DEFF Research Database (Denmark)

    Kallin, Eric M; Rodríguez-Ubreva, Javier; Christensen, Jesper Aagaard

    2012-01-01

    The methylcytosine hydroxylase Tet2 has been implicated in hematopoietic differentiation and the formation of myeloid malignancies when mutated. An ideal system to study the role of Tet2 in myelopoeisis is CEBPα-induced transdifferentiation of pre-B cells into macrophages. Here we found that CEBP...

  19. Validation and implementation of a method for microarray gene expression profiling of minor B-cell subpopulations in man

    DEFF Research Database (Denmark)

    Bergkvist, Kim Steve; Nyegaard, Mette; Bøgsted, Martin

    2014-01-01

    and therefore it is important to optimize and validate each step in the procedure. METHODS: Normal lymphoid tissues from blood, tonsils, thymus and bone marrow were immunophenotyped by the 8-colour Euroflow panel using multiparametric flow cytometry. Subsets of B-cells containing cell numbers ranging from 800...... mRNA following storage in lysis/binding buffer (p bone marrow and tonsil samples...

  20. ZNF384-related fusion genes define a subgroup of childhood B-cell precursor acute lymphoblastic leukemia with a characteristic immunotype.

    Science.gov (United States)

    Hirabayashi, Shinsuke; Ohki, Kentaro; Nakabayashi, Kazuhiko; Ichikawa, Hitoshi; Momozawa, Yukihide; Okamura, Kohji; Yaguchi, Akinori; Terada, Kazuki; Saito, Yuya; Yoshimi, Ai; Ogata-Kawata, Hiroko; Sakamoto, Hiromi; Kato, Motohiro; Fujimura, Junya; Hino, Moeko; Kinoshita, Akitoshi; Kakuda, Harumi; Kurosawa, Hidemitsu; Kato, Keisuke; Kajiwara, Ryosuke; Moriwaki, Koichi; Morimoto, Tsuyoshi; Nakamura, Kozue; Noguchi, Yasushi; Osumi, Tomoo; Sakashita, Kazuo; Takita, Junko; Yuza, Yuki; Matsuda, Koich; Yoshida, Teruhiko; Matsumoto, Kenji; Hata, Kenichiro; Kubo, Michiaki; Matsubara, Yoichi; Fukushima, Takashi; Koh, Katsuyoshi; Manabe, Atsushi; Ohara, Akira; Kiyokawa, Nobutaka

    2017-01-01

    Fusion genes involving ZNF384 have recently been identified in B-cell precursor acute lymphoblastic leukemia, and 7 fusion partners have been reported. We further characterized this type of fusion gene by whole transcriptome sequencing and/or polymerase chain reaction. In addition to previously reported genes, we identified BMP2K as a novel fusion partner for ZNF384 Including the EP300-ZNF384 that we reported recently, the total frequency of ZNF384-related fusion genes was 4.1% in 291 B-cell precursor acute lymphoblastic leukemia patients enrolled in a single clinical trial, and TCF3-ZNF384 was the most recurrent, with a frequency of 2.4%. The characteristic immunophenotype of weak CD10 and aberrant CD13 and/or CD33 expression was revealed to be a common feature of the leukemic cells harboring ZNF384-related fusion genes. The signature gene expression profile in TCF3-ZNF384-positive patients was enriched in hematopoietic stem cell features and related to that of EP300-ZNF384-positive patients, but was significantly distinct from that of TCF3-PBX1-positive and ZNF384-fusion-negative patients. However, clinical features of TCF3-ZNF384-positive patients are markedly different from those of EP300-ZNF384-positive patients, exhibiting higher cell counts and a younger age at presentation. TCF3-ZNF384-positive patients revealed a significantly poorer steroid response and a higher frequency of relapse, and the additional activating mutations in RAS signaling pathway genes were detected by whole exome analysis in some of the cases. Our observations indicate that ZNF384-related fusion genes consist of a distinct subgroup of B-cell precursor acute lymphoblastic leukemia with a characteristic immunophenotype, while the clinical features depend on the functional properties of individual fusion partners. Copyright© Ferrata Storti Foundation.

  1. A microarray platform-independent classification tool for cell of origin class allows comparative analysis of gene expression in diffuse large B-cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Matthew A Care

    Full Text Available Cell of origin classification of diffuse large B-cell lymphoma (DLBCL identifies subsets with biological and clinical significance. Despite the established nature of the classification existing studies display variability in classifier implementation, and a comparative analysis across multiple data sets is lacking. Here we describe the validation of a cell of origin classifier for DLBCL, based on balanced voting between 4 machine-learning tools: the DLBCL automatic classifier (DAC. This shows superior survival separation for assigned Activated B-cell (ABC and Germinal Center B-cell (GCB DLBCL classes relative to a range of other classifiers. DAC is effective on data derived from multiple microarray platforms and formalin fixed paraffin embedded samples and is parsimonious, using 20 classifier genes. We use DAC to perform a comparative analysis of gene expression in 10 data sets (2030 cases. We generate ranked meta-profiles of genes showing consistent class-association using ≥6 data sets as a cut-off: ABC (414 genes and GCB (415 genes. The transcription factor ZBTB32 emerges as the most consistent and differentially expressed gene in ABC-DLBCL while other transcription factors such as ARID3A, BATF, and TCF4 are also amongst the 24 genes associated with this class in all datasets. Analysis of enrichment of 12323 gene signatures against meta-profiles and all data sets individually confirms consistent associations with signatures of molecular pathways, chromosomal cytobands, and transcription factor binding sites. We provide DAC as an open access Windows application, and the accompanying meta-analyses as a resource.

  2. A diverse repertoire of human immunoglobulin variable genes in a chicken B cell line is generated by both gene conversion and somatic hypermutation

    Directory of Open Access Journals (Sweden)

    Philip A. Leighton

    2015-03-01

    Full Text Available Chicken immune responses to human proteins are often more robust than rodent responses because of the phylogenetic relationship between the different species. For discovery of a diverse panel of unique therapeutic antibody candidates, chickens therefore represent an attractive host for human-derived targets. Recent advances in monoclonal antibody technology, specifically new methods for the molecular cloning of antibody genes directly from primary B cells, has ushered in a new era of generating monoclonal antibodies from non-traditional host animals that were previously inaccessible through hybridoma technology. However, such monoclonals still require post-discovery humanization in order to be developed as therapeutics. To obviate the need for humanization, a modified strain of chickens could be engineered to express a human sequence immunoglobulin variable region repertoire. Here, human variable genes introduced into the chicken immunoglobulin loci through gene targeting were evaluated for their ability to be recognized and diversified by the native chicken recombination machinery that is present in the B-lineage cell line DT40. After expansion in culture the DT40 population accumulated genetic mutants that were detected via deep sequencing. Bioinformatic analysis revealed that the human targeted constructs are performing as expected in the cell culture system, and provide a measure of confidence that they will be functional in transgenic animals.

  3. Polymorphism of 41 kD Flagellin Gene and Its Human B-Cell Epitope in Borrelia burgdorferi Strains of China

    Directory of Open Access Journals (Sweden)

    Huixin Liu

    2016-01-01

    Full Text Available The 41 kD flagellin of Borrelia burgdorferi (B. burgdorferi is a major component of periplasmic flagellar filament core and a good candidate for serodiagnosis in early stage of Lyme disease. Here, we chose 89 B. burgdorferi strains in China, amplified the gene encoding the 41 kD flagellin, and compared the sequences. The results showed that genetic diversity presented in the 41 kD flagellin genes of all 89 strains among the four genotypes of B. burgdorferi, especially in the genotype of B. garinii. Some specific mutation sites for each genotype of the 41 kD flagellin genes were found, which could be used for genotyping B. burgdorferi strains in China. Human B-cell epitope analysis showed that thirteen of 15 nonsynonymous mutations occurred in the epitope region of 41 kD flagellin and thirty of 42 B-cell epitopes were altered due to all 13 nonsynonymous mutations in the epitope region, which may affect the function of the antigen. Nonsynonymous mutations and changed human B-cell epitopes exist in 41 kD flagellin of B. burgdorferi sensu lato strains; these changes should be considered in serodiagnosis of Lyme disease.

  4. MYC translocation partner gene determines survival of patients with large B-cell lymphoma with MYC- or double-hit MYC/BCL2 translocations

    DEFF Research Database (Denmark)

    Pedersen, Mette Ø; Gang, Anne O; Poulsen, Tim S

    2014-01-01

    In large B-cell lymphoma (LBCL) MYC- and MYC/BCL2 double-hit (DH) translocations have been associated with inferior survival. We hypothesised that the negative prognostic impact of MYC translocation was determined by an immunoglobulin MYC translocation partner gene (IG-MYC), as opposed to a non......-immunoglobulin partner gene (nonIG-MYC). In a prospective, unselected cohort of 237 LBCL patients MYC and BCL2 translocations were identified by fluorescent in situ hybridisation (FISH) with split probes. MYC translocation partner gene was identified by IGH/MYC fusion probes and/or kappa/lambda split probes. Clinical...... data were collected from patient files. MYC translocation was identified in 28/225 patients. IG-MYC translocation partner gene was identified in 12/24 patients. DH translocation was identified in 23/228 patients. IG-MYC translocation partner gene was identified in 9/19 DH patients. Neither MYC-nor DH...

  5. Protein expression of B-cell lymphoma gene 6 (BCL-6) in invasive breast cancer is associated with cyclin D1 and hypoxia-inducible factor-1α (HIF-1α)

    NARCIS (Netherlands)

    Bos, R.; Diest, P.J. van; Groep, P. van der; Greijer, A.E.; Hermsen, M.A.J.A.; Heijnen, I.; Meijer, G.A.; Baak, J.P.A.; Pinedo, H.M.; Wall, E. van der; Shvarts, A.

    2003-01-01

    B-cell lymphoma gene (BCL-6) upregulation contributes to immortalization of mouse embryo fibroblast and primary B cells via upregulation of cyclin D1. As cyclin D1 overexpression is a common phenomenon in different cancers, BCL-6 protein overexpression may not be restricted to lymphomas. In this

  6. Inferring a role for methylation of intergenic DNA in the regulation of genes aberrantly expressed in precursor B-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Almamun, Md; Kholod, Olha; Stuckel, Alexei J; Levinson, Benjamin T; Johnson, Nathan T; Arthur, Gerald L; Davis, J Wade; Taylor, Kristen H

    2017-09-01

    A complete understanding of the mechanisms involved in the development of pre-B ALL is lacking. In this study, we integrated DNA methylation data and gene expression data to elucidate the impact of aberrant intergenic DNA methylation on gene expression in pre-B ALL. We found a subset of differentially methylated intergenic loci that were associated with altered gene expression in pre-B ALL patients. Notably, 84% of these regions were also bound by transcription factors (TF) known to play roles in differentiation and B-cell development in a lymphoblastoid cell line. Further, an overall downregulation of eRNA transcripts was observed in pre-B ALL patients and these transcripts were associated with the downregulation of putative target genes involved in B-cell migration, proliferation, and apoptosis. The identification of novel putative regulatory regions highlights the significance of intergenic DNA sequences and may contribute to the identification of new therapeutic targets for the treatment of pre-B ALL.

  7. Characterization and expression analysis of B Cell receptor accessory molecule CD79 gene in humphead snapper ( Lutjanus sanguineus)

    Science.gov (United States)

    Huang, Yucong; Yan, Xiuying; Cai, Shuanghu; Cai, Jia; Jian, Jichang; Lu, Yishan; Tang, Jufen; Wu, Zaohe

    2016-04-01

    CD79, a key component of the B cell antigen receptor complex, is composed of CD79α(Igα) and CD79β(Igβ) encoded by mb-1 and B29 respectively, and plays an important role in B cell signaling. In this study, we isolated and characterized mb-1 and B29 from humphead snapper ( Lutjanus sanguineus). Their tissue distribution and expression profiles after stimulations in vitro and in vivo were also investigated. The humphead snapper mb-1 and B29 contain open reading frames of 684 bp and 606 bp, encoding 227 amino acids and 201 amino acids, respectively. Both CD79α and CD79β possess signal peptide, extracellular Ig domain, transmembrane region and immunoreceptor tyrosine kinase activation motif (ITAM). Mb-1 is highly expressed in lymphoid organs (thymus, posterior kidney and spleen) and mucosal-associated lymphoid tissues (gill and intestine), while B29 is mainly detected in posterior kidney, spleen, gill and skin. Furthermore, transcription of mb-1 and B29 in head kidney leucocytes was up-regulated following lipopolysaccharide (LPS), pokeweed mitogen (PWM), and polyinosinic-polycytidylic acid (PolyI:C) stimulation, respectively, and their expression level in anterior kidney and spleen was also increased after challenged with formalin-inactived Vibrio harveyi. These results indicated that humphead snapper CD79 molecule might play an important role in immune response to pathogen infection.

  8. Methylenetetrahydrofolate reductase genotype in diffuse large B-cell lymphomas with and without hypermethylation of the DNA repair gene O6-methylguanine DNA methyltransferase.

    Science.gov (United States)

    Toffoli, G; Rossi, D; Gaidano, G; Cecchin, E; Boiocchi, M; Carbone, A

    2003-01-01

    C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) polymorphisms have been suggested to affect susceptibility to malignant lymphoma, possibly by altering DNA methylation. The DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) is transcriptionally silenced by promoter hypermethylation in diffuse large B-cell lymphomas (DLBCL). We analyzed the MTHFR677 and MTHFR1298 genotypes in 111 DLBCL patients and 465 controls. No significant difference in the frequency of MTHFR polymorphisms between patients and controls and no significant association between MTHFR677 or MTHFR1298 genotypes and methylation of MGMT promoter were observed. These results indicate that MTHFR variants are not related to DLBCL development and MGMT hypermethylation.

  9. EBNA2 Drives Formation of New Chromosome Binding Sites and Target Genes for B-Cell Master Regulatory Transcription Factors RBP-jκ and EBF1.

    Science.gov (United States)

    Lu, Fang; Chen, Horng-Shen; Kossenkov, Andrew V; DeWispeleare, Karen; Won, Kyoung-Jae; Lieberman, Paul M

    2016-01-01

    Epstein-Barr Virus (EBV) transforms resting B-lymphocytes into proliferating lymphoblasts to establish latent infections that can give rise to malignancies. We show here that EBV-encoded transcriptional regulator EBNA2 drives the cooperative and combinatorial genome-wide binding of two master regulators of B-cell fate, namely EBF1 and RBP-jκ. Previous studies suggest that these B-cell factors are statically bound to target gene promoters. In contrast, we found that EBNA2 induces the formation of new binding for both RBP-jκ and EBF1, many of which are in close physical proximity in the cellular and viral genome. These newly induced binding sites co-occupied by EBNA2-EBF1-RBP-jκ correlate strongly with transcriptional activation of linked genes that are important for B-lymphoblast function. Conditional expression or repression of EBNA2 leads to a rapid alteration in RBP-jκ and EBF1 binding. Biochemical and shRNA depletion studies provide evidence for cooperative assembly at co-occupied sites. These findings reveal that EBNA2 facilitate combinatorial interactions to induce new patterns of transcription factor occupancy and gene programming necessary to drive B-lymphoblast growth and survival.

  10. EBNA2 Drives Formation of New Chromosome Binding Sites and Target Genes for B-Cell Master Regulatory Transcription Factors RBP-jκ and EBF1.

    Directory of Open Access Journals (Sweden)

    Fang Lu

    2016-01-01

    Full Text Available Epstein-Barr Virus (EBV transforms resting B-lymphocytes into proliferating lymphoblasts to establish latent infections that can give rise to malignancies. We show here that EBV-encoded transcriptional regulator EBNA2 drives the cooperative and combinatorial genome-wide binding of two master regulators of B-cell fate, namely EBF1 and RBP-jκ. Previous studies suggest that these B-cell factors are statically bound to target gene promoters. In contrast, we found that EBNA2 induces the formation of new binding for both RBP-jκ and EBF1, many of which are in close physical proximity in the cellular and viral genome. These newly induced binding sites co-occupied by EBNA2-EBF1-RBP-jκ correlate strongly with transcriptional activation of linked genes that are important for B-lymphoblast function. Conditional expression or repression of EBNA2 leads to a rapid alteration in RBP-jκ and EBF1 binding. Biochemical and shRNA depletion studies provide evidence for cooperative assembly at co-occupied sites. These findings reveal that EBNA2 facilitate combinatorial interactions to induce new patterns of transcription factor occupancy and gene programming necessary to drive B-lymphoblast growth and survival.

  11. VDJ gene usage among B-cell receptors in ABO-incompatible kidney transplantation determined by RNA-seq Transcriptomic analysis.

    Science.gov (United States)

    Jeon, Hee Jung; Kim, Kwangsoo; Lee, Jae-Ghi; Jang, Joon Young; Choi, Seongmin; Fang, Taishi; Yan, Ji-Jing; Han, Miyeun; Jeong, Jong Cheol; Lee, Kyoung-Bun; Kim, Tae Jin; Ahn, Curie; Yang, Jaeseok

    2017-11-28

    Studies on B-cell subtypes and V(D)J gene usage of B-cell receptors in kidney transplants are scarce. This study aimed to investigate V(D)J gene segment usage in ABO-incompatible (ABOi) kidney transplant (KT) patients compared to that in ABO-compatible (ABOc) KT patients. We selected 16 ABOi KT patients with accommodation (ABOiA), 6 ABOc stable KT patients (ABOcS), and 6 ABOi KT patients with biopsy-proven acute antibody-mediated rejection (ABOiR) at day 10, whose graft tissue samples had been stored in the biorepository between 2010 and 2014. Complete transcriptomes of graft tissues were sequenced and analyzed through RNA sequencing (RNA-seq). The international ImMunoGeneTics information system (IMGT®) was used for in-depth comparison of V(D)J gene segment usage. The mean age of the 28 KT recipients was 43.3 ± 12.8 years, and 53.6% were male. By family, IGHV3, IGHJ4, IGLV2, and IGLJ3 gene segments were most frequently used in all groups, and their usage was not statistically different among the three patient groups. While IGKV3 was most frequently used in both the ABOiA and ABOiR groups, IGKV1 was most commonly used in the ABOcS group. In addition, while IGKJ1 was most commonly used in the ABOiA and ABOcS groups, IGKJ4 was most frequently used in the ABOiR group. According to individual gene segments, IGHV4-34 and IGHV4-30-2 were more commonly used in the ABOiR group than in the ABOiA group, and IGHV6-1 was more commonly used in the ABOcS group than in the ABOiR group. IGLV7-43 was more commonly used in the ABOcS group than in the ABOi group. However, technical variability, small sample size, and potential confounding effects of Rituximab or HLA mismatching are limitations of our study. Our findings suggest that RNA-seq transcriptomic analyses can provide information on the V(D)J gene usage of B-cell receptors and the mechanisms of accommodation and immune reaction in ABOi KT.

  12. High Throughput Sequencing Analysis of the Immunoglobulin Heavy Chain Gene from Flow-Sorted B Cell Sub-Populations Define the Dynamics of Follicular Lymphoma Clonal Evolution.

    Directory of Open Access Journals (Sweden)

    Emanuela Carlotti

    Full Text Available Understanding the dynamics of evolution of Follicular Lymphoma (FL clones during disease progression is important for monitoring and targeting this tumor effectively. Genetic profiling of serial FL biopsies and examples of FL transmission following bone marrow transplant suggest that this disease may evolve by divergent evolution from a common ancestor cell. However where this ancestor cell resides and how it evolves is still unclear. The analysis of the pattern of somatic hypermutation of the immunoglobulin gene (Ig is traditionally used for tracking the physiological clonal evolution of B cells within the germinal center and allows to discriminate those cells that have just entered the germinal center and display features of ancestor cells from those B cells that keep re-circulating across different lymphoid organs. Here we investigated the pattern of somatic hypermutation of the heavy chain of the immunoglobulin gene (IgH-VH in 4 flow-sorted B cells subpopulations belonging to different stages of differentiation, from sequential lymph node biopsies of cases displaying diverse patterns of evolution, using the GS-FLX Titanium sequencing platform. We observed an unexpectedly high level of clonality, with hundreds of distinct tumor subclones in the different subpopulations from the same sample, the majority detected at a frequency <10-2. By using a lineage trees analysis we observed in all our FL and t-FL cases that the oligoclonal FL population was trapped in a narrow intermediate stage of maturation that maintains the capacity to undergo SHM, but was unable to further differentiate. The presence of such a complex architecture highlights challenges currently encountered in finding a cure for this disease.

  13. Lack of association between deletion polymorphism of BIM gene and in vitro drug sensitivity in B-cell precursor acute lymphoblastic leukemia.

    Science.gov (United States)

    Huang, Meixian; Miyake, Kunio; Kagami, Keiko; Abe, Masako; Shinohara, Tamao; Watanabe, Atsushi; Somazu, Shinpei; Oshiro, Hiroko; Goi, Kumiko; Goto, Hiroaki; Minegishi, Masayoshi; Iwamoto, Shotaro; Kiyokawa, Nobutaka; Sugita, Kanji; Inukai, Takeshi

    2017-09-01

    A deletion polymorphism in the BIM gene was identified as an intrinsic mechanism for resistance to tyrosine kinase inhibitor in chronic myeloid leukemia patients in East Asia. BIM is also involved in the responses to glucocorticoid and chemotherapy in acute lymphoblastic leukemia (ALL), suggesting a possible association between deletion polymorphism of BIM and the chemosensitivity of ALL. Thus, we analyzed 72 B-cell precursor (BCP)-ALL cell lines established from Japanese patients. Indeed, higher BIM gene expression was associated with good in vitro sensitivities to glucocorticoid and chemotherapeutic agents used in induction therapy. We also analyzed the methylation status of the BIM gene promoter by next generation sequencing of genome bisulfite PCR products, since genetic polymorphism could be insignificant when epigenetically inactivated. Hypermethylation of the BIM gene promoter was associated with lower BIM gene expression and poorer sensitivity to vincristine. Of note, however, the prevalence of a deletion polymorphism was not associated with the BIM gene expression level or drug sensitivities in BCP-ALL cell lines, in which the BIM gene was unmethylated. These observations suggest that an association of a deletion polymorphism of BIM and the response to induction therapy in BCP-ALL may be clinically minimal. Copyright © 2017. Published by Elsevier Ltd.

  14. Recurrent mutations of the exportin 1 gene (XPO1) and their impact on selective inhibitor of nuclear export compounds sensitivity in primary mediastinal B-cell lymphoma.

    Science.gov (United States)

    Jardin, Fabrice; Pujals, Anais; Pelletier, Laura; Bohers, Elodie; Camus, Vincent; Mareschal, Sylvain; Dubois, Sydney; Sola, Brigitte; Ochmann, Marlène; Lemonnier, François; Viailly, Pierre-Julien; Bertrand, Philippe; Maingonnat, Catherine; Traverse-Glehen, Alexandra; Gaulard, Philippe; Damotte, Diane; Delarue, Richard; Haioun, Corinne; Argueta, Christian; Landesman, Yosef; Salles, Gilles; Jais, Jean-Philippe; Figeac, Martin; Copie-Bergman, Christiane; Molina, Thierry Jo; Picquenot, Jean Michel; Cornic, Marie; Fest, Thierry; Milpied, Noel; Lemasle, Emilie; Stamatoullas, Aspasia; Moeller, Peter; Dyer, Martin J S; Sundstrom, Christer; Bastard, Christian; Tilly, Hervé; Leroy, Karen

    2016-09-01

    Primary mediastinal B-cell lymphoma (PMBL) is an entity of B-cell lymphoma distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin-β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray-zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT-185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP-defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild-type cases. KPT-185 induced a dose-dependent decrease in cell proliferation and increased cell-death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT-330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild-type protein. Am. J. Hematol. 91:923-930, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Genetic polymorphisms of methylenetetrahydrofolate reductase and promoter methylation of MGMT and FHIT genes in diffuse large B cell lymphoma risk in Middle East.

    Science.gov (United States)

    Siraj, Abdul K; Ibrahim, Muna; Al-Rasheed, Maha; Bu, Rong; Bavi, Prashant; Jehan, Zeenath; Abubaker, Jehad; Murad, Walid; Al-Dayel, Fouad; Ezzat, Adnan; El-Solh, Hassan; Uddin, Shahab; Al-Kuraya, Khawla

    2007-12-01

    Diffuse large B cell lymphoma (DLBCL) is one of the most common non-Hodgkin's lymphoma types. Methylenetetrahydrofolate reductase (MTHFR) balances the pool of folate coenzymes in one carbon metabolism of deoxyribonucleic acid (DNA) synthesis and methylation; both are implicated in carcinogenesis of many types of cancer including lymphoma. Two common variants in the MTHFR gene (C677T and A1298C) have been associated with reduced enzyme activity, thereby making MTHFR polymorphisms a potential candidate as a cancer-predisposing factor. The O6 methylguanine DNA methyltransferase (MGMT) and fragile histidine triad (FHIT) genes are transcriptionally silenced by promoter hypermethylation in DLBCL. These genetic differences are highly race specific and have never been screened in the Saudi DLBCL patients. We conducted a hospital-based case-control study including 160 DLBCL cases and 511 Saudi control samples analyzing the MTHFR C677T and A1298C functional polymorphisms by the restriction fragment length polymorphism method and their association with MGMT and FHIT genes promoter hypermethylation. Our data demonstrated that Saudi individuals carrying MTHFR genotype 1298CC (p methylation of MGMT and FHIT genes were observed. Our findings suggested that polymorphisms of MTHFR enzyme genes might be associated with the individual susceptibility to develop DLBCL. Additionally, the results indicated that MTHFR variants were not related to MGMT or FHIT hypermethylation in DLBCL.

  16. Comparison of clastogen-induced gene expression profiles in wild-type and DNA repair-deficient Rad54/Rad54B cells

    Directory of Open Access Journals (Sweden)

    van Benthem Jan

    2010-01-01

    Full Text Available Abstract Background Previously we found that Rad54/Rad54B cells are more sensitive towards mitomycin C (MMC as compared to wild-type (WT cells. This difference in sensitivity was absent upon exposure to other clastogens like bleomycin (BLM and γ-radiation. In order to get further insight into possible underlying mechanisms, gene expression changes in WT and Rad54/Rad54B MEFs (mouse embryonic fibroblasts after exposure to the clastogens MMC and BLM were investigated. Exposures of these cells to mutagens (N-ac-AAF and ENU and vehicle were taken as controls. Results Most exposures resulted in an induction of DNA damage signaling and apoptosis genes and a reduced expression of cell division genes in cells of both genotypes. As expected, responses to N-ac-AAF were very similar in both genotypes. ENU exposure did not lead to significant gene expression changes in cells of both genotypes, presumably due to its short half-life. Gene expression responses to clastogens, however, showed a genotype-dependent effect for BLM and MMC. MMC treated Rad54/Rad54B MEFs showed no induction of p53-signaling, DNA damage response and apoptosis as seen for all the other treatments. Conclusion These data support our finding that different types of clastogens exist and that responses to these types depend on the DNA repair status of the cells.

  17. Epstein - Barr virus transforming protein LMP-1 alters B cells gene expression by promoting accumulation of the oncoprotein ΔNp73α.

    Directory of Open Access Journals (Sweden)

    Rosita Accardi

    2013-03-01

    Full Text Available Many studies have proved that oncogenic viruses develop redundant mechanisms to alter the functions of the tumor suppressor p53. Here we show that Epstein-Barr virus (EBV, via the oncoprotein LMP-1, induces the expression of ΔNp73α, a strong antagonist of p53. This phenomenon is mediated by the LMP-1 dependent activation of c-Jun NH2-terminal kinase 1 (JNK-1 which in turn favours the recruitment of p73 to ΔNp73α promoter. A specific chemical inhibitor of JNK-1 or silencing JNK-1 expression strongly down-regulated ΔNp73α mRNA levels in LMP-1-containing cells. Accordingly, LMP-1 mutants deficient to activate JNK-1 did not induce ΔNp73α accumulation. The recruitment of p73 to the ΔNp73α promoter correlated with the displacement of the histone-lysine N-methyltransferase EZH2 which is part of the transcriptional repressive polycomb 2 complex. Inhibition of ΔNp73α expression in lymphoblastoid cells (LCLs led to the stimulation of apoptosis and up-regulation of a large number of cellular genes as determined by whole transcriptome shotgun sequencing (RNA-seq. In particular, the expression of genes encoding products known to play anti-proliferative/pro-apoptotic functions, as well as genes known to be deregulated in different B cells malignancy, was altered by ΔNp73α down-regulation. Together, these findings reveal a novel EBV mechanism that appears to play an important role in the transformation of primary B cells.

  18. Association in a Chinese population of a genetic variation in the early B-cell factor 1 gene with coronary artery disease.

    Science.gov (United States)

    Li, Yafei; Xie, Zhiyong; Chen, Lei; Yan, Jianjun; Ma, Yao; Wang, Liansheng; Chen, Zhong

    2017-02-10

    Early B-cell factor 1 (EBF1) is a transcription factor expressed primarily during early B cell development. Previous studies have shown EBF1 regulates blood glucose and lipid metabolism in mice with diabetes and central adiposity. Recently, a genetic variation (rs36071027) located in an EBF1 gene intron was associated with carotid artery intima-media thickness. However, whether this polymorphism is actually linked with coronary artery disease (CAD) and its severity remains unclear. This study includes 293 CAD cases and 262 controls without CAD. All participants were devided into two groups based on their coronary angiography results. A polymerase chain reaction-ligase detection reaction was used to identify genotypes at rs36071027, and CAD patients were further divided into subgroups with one-, two-, or three-vessel stenosis reflective of CAD severity. The frequency of the rs36071027 TT genotype was significantly higher in CAD cases versus controls (4.8% vs. 1.5%, 95% CI: 1.13-10.81 P = 0.029). Subjects with a variant genotype T allele had an increased risk of CAD compared to C allele carriers (additive model: 95% CI: 1.13-2.23, P = 0.008). After adjustment for cardiovascular risk factors, analysis of the additive and dominant models involving rs36071027 also revealed that T allele carriers had a significantly higher risk for CAD than C allele carriers (additive model: OR 1.56, 95% CI 1.10-2.22, P = 0.013; dominant model: OR 1.60, 95% CI 1.07-2.41, P = 0.023). Furthermore, both diabetes and the CT + TT rs36071027 genotype were significantly associated with three-vessel stenosis. Our results in a Chinese population suggest that the TT genotype and T alleles in rs36071027 in the EBF1 gene are associated with an increased risk of CAD and its severity.

  19. Proof of the concept to use a malignant B cell line drug screen strategy for identification and weight of melphalan resistance genes in multiple myeloma.

    Directory of Open Access Journals (Sweden)

    Martin Bøgsted

    Full Text Available In a conceptual study of drug resistance we have used a preclinical model of malignant B-cell lines by combining drug induced growth inhibition and gene expression profiling. In the current report a melphalan resistance profile of 19 genes were weighted by microarray data from the MRC Myeloma IX trial and time to progression following high dose melphalan, to generate an individual melphalan resistance index. The resistance index was subsequently validated in the HOVON65/GMMG-HD4 trial data set to prove the concept. Biologically, the assigned resistance indices were differentially distributed among translocations and cyclin D expression classes. Clinically, the 25% most melphalan resistant, the intermediate 50% and the 25% most sensitive patients had a median progression free survival of 18, 32 and 28 months, respectively (log-rank P-value  = 0.05. Furthermore, the median overall survival was 45 months for the resistant group and not reached for the intermediate and sensitive groups (log-rank P-value  = 0.003 following 38 months median observation. In a multivariate analysis, correcting for age, sex and ISS-staging, we found a high resistance index to be an independent variable associated with inferior progression free survival and overall survival. This study provides clinical proof of concept to use in vitro drug screen for identification of melphalan resistance gene signatures for future functional analysis.

  20. BCL2 gene aberration as an IPI-independent marker for poor outcome in non-germinal-centre diffuse large B cell lymphoma.

    Science.gov (United States)

    Obermann, E C; Csato, M; Dirnhofer, S; Tzankov, A

    2009-10-01

    Diffuse large B cell lymphoma (DLBCL) is the most common lymphoid malignancy in the western hemisphere, and is characterised by a highly variable outcome that impedes individual risk assessment. Lacking reliable biomarkers, the international prognostic index (IPI) has been the most reliable factor to predict survival and stratify patients for therapy. The aim of this study was to investigate the frequency and potential prognostic role of BCL2 aberrations on the chromosomal level and the protein level in a large DLBCL collective. Fluorescence in situ hybridisation (FISH) with commercially available dual-colour break-apart probes and immunohistochemistry were used to assess BCL2 gene abnormalities and bcl2 protein expression on validated tissue microarrays containing 224 well-characterised cases of primary DLBCL. FISH analysis of BCL2 revealed a break in 40/215 cases (19%) and a gain in 66/171 (39%) cases. Only BCL2 gains correlated with bcl2 protein expression (p = 0.001). Presence of any BCL2 gene abnormality, particularly gains, correlated independently of the IPI with a significantly worse prognosis in DLBCL of non-germinal centre (non-GC) phenotype as opposed to DLBCL of non-GC type without this genetic alteration (p = 0.003). DLBCL of germinal centre phenotype did not show this association. Cases of DLBCL of the non-GC type with BCL2 gene aberration are accompanied by a significantly worse prognosis as opposed to cases without such gene abnormalities. It may be helpful to asses BCL2 gene abnormalities by FISH in addition to assessing established parameters for individual risk estimation in DLBCL.

  1. The gene encoding the mouse contactin-1 axonal glycoprotein is regulated by the collier/Olf1/EBF family early B-Cell factor 2 transcription factor.

    Science.gov (United States)

    Bizzoca, Antonella; Picocci, Sabrina; Corsi, Patrizia; Arbia, Stefania; Croci, Laura; Consalez, G Giacomo; Gennarini, Gianfranco

    2015-12-01

    The Contactin-1 axonal glycoprotein (formerly F3/Contactin) plays a relevant role in cerebellar ontogenesis, as shown in Contactin-1 KO-mice and in transgenic mice misexpressing the corresponding cDNA from a heterologous promoter. Likewise, null mutant mice for the Collier/Olf1/Early B-cell family transcription factor EBF2, in which Purkinje neuron development is primarily affected, exhibit abnormalities in cerebellar corticogenesis. Here, to evaluate the contribution to the Ebf2 null phenotype of changes in the profile of Contactin-1, we study its expression in Ebf2 null mice. In addition, we explore the activation profile of the Cntn1 gene promoter upon transferring the Ebf2 mutation to transgenic mice expressing an enhanced green fluorescent protein reporter under control of Cntn1 gene regulatory sequences. In Ebf2 null mice, Contactin-1 protein expression and Cntn1 gene promoter activity are both downregulated during embryonic and early postnatal cerebellar development, both in the rostral and caudal folia, while in the latter an upregulation is observed at postnatal day 8. In vitro, vectors driving EBF1,2,3 transcription factors from a cytomegalovirus (CMV) promoter transactivate a Cntn1-Choline acetyltransferse (CAT) promoter-reporter construct in cotransfection assays and, accordingly, by chromatin immunoprecipitation, we show that the Cntn1 gene 5' flanking region is bound by the EBF2 transcription factor, consistent with the evidence that this region bears the cognate deoxyribonucleic acid (DNA) consensus sequences. These data indicate that Contactin-1 expression is dependent upon EBF factors, suggesting that the Cntn1 gene belongs to the expanding regulatory cascade driven by these transcriptional regulators so that changes in its activation may contribute to the phenotype of Ebf2 null mutant mice. © 2015 Wiley Periodicals, Inc.

  2. Cotton Leaf Curl Multan Betasatellite DNA as a Tool to Deliver and Express the Human B-Cell Lymphoma 2 (Bcl-2) Gene in Plants.

    Science.gov (United States)

    Kharazmi, Sara; Ataie Kachoie, Elham; Behjatnia, Seyed Ali Akbar

    2016-05-01

    The betasatellite DNA associated with Cotton leaf curl Multan virus (CLCuMB) contains a single complementary-sense ORF, βC1, which is a pathogenicity determinant. CLCuMB was able to replicate in plants in the presence of diverse helper geminiviruses, including Tomato leaf curl virus-Australia (TLCV-Au), Iranian isolate of Tomato yellow leaf curl virus (TYLCV-[Ab]), and Beet curly top virus (BCTV-Svr), and can be used as a plant gene delivery vector. To test the hypothesis that CLCuMB has the potential to act as an animal gene delivery vector, a specific insertion construct was produced by the introduction of a human B-cell lymphoma 2 (Bcl-2) cDNA into a mutant DNA of CLCuMB in which the βC1 was deleted (β∆C1). The recombinant βΔC1-Bcl-2 construct was successfully replicated in tomato and tobacco plants in the presence of TLCV-Au, BCTV-Svr and TYLCV-[Ab]. Real-time PCR and Western blot analyses of plants containing the replicative forms of recombinant βΔC1-Bcl-2 DNA showed that Bcl-2 gene was expressed in an acceptable level in these plants, indicating that β∆C1 can be used as a tool to deliver and express animal genes in plants. This CLCuMB-based system, having its own promoter activity, offers the possibility of production of animal recombinant proteins in plants.

  3. p16 Tumor Suppressor Gene Methylation in Diffuse Large B Cell Lymphoma: A Study of 88 Cases at Two Hospitals in the East Coast of Malaysia

    Science.gov (United States)

    Mohd Ridah, Lailatul Jalilah; A Talib, Norlelawati; Muhammad, Naznin; Hussain, Faezahtul Arbaeyah; Zainuddin, Norafiza

    2017-10-26

    Introduction: p16 gene plays an important role in the normal cell cycle regulation. Methylation of p16 has been reported to be one of the epigenetic events contributing to the pathogenesis of diffuse large B-cell lymphoma (DLBCL) which occurring at varying frequency. DLBCL is an aggressive and high-grade malignancy which accounts for approximately 30% of all non-Hodgkin lymphoma cases. However, little is known regarding the epigenetic alterations of p16 gene in DLBCL cases in Malaysia. Therefore, the objective of this study was to examine the status of p16 methylation in DLBCL. Methods: A total of 88 formalin-fixed paraffin-embedded DLBCL tissues retrieved from two hospitals located in the east coast of Malaysia, namely Hospital Tengku Ampuan Afzan (HTAA) Pahang and Hospital Universiti Sains Malaysia (HUSM) Kelantan, were chosen for this study. DNA specimens were isolated and subsequently subjected to bisulfite treatment prior to methylation specific-PCR. Two pairs of primers were used to amplify methylated and unmethylated regions of p16 gene. The PCR products were then separated using agarose gel electrophoresis and visualised under UV illumination. SPSS version 12.0 was utilised to perform all statistical analysis. Result: p16 methylation was detected in 65 of 88 (74%) samples. There was a significant association between p16 methylation status and patients aged >50 years old (p=0.04). Conclusion: Our study demonstrated that methylation of p16 tumor suppressor gene in our DLBCL cases is common and significantly increased among patients aged 50 years and above. Aging is known to be an important risk factor in the development of cancers and we speculate that this might be due to the increased transformation of malignant cells in aging cell population. However, this has yet to be confirmed with further research and correlate the findings with clinicopathological parameters. Creative Commons Attribution License

  4. Generation and CRISPR/Cas9 editing of transformed progenitor B cells as a pseudo-physiological system to study DNA repair gene function in V(D)J recombination.

    Science.gov (United States)

    Lenden Hasse, Hélène; Lescale, Chloé; Bianchi, Joy J; Yu, Wei; Bedora-Faure, Marie; Deriano, Ludovic

    2017-12-01

    Antigen receptor gene assembly is accomplished in developing lymphocytes by the V(D)J recombination reaction, which can be separated into two steps: DNA cleavage by the recombination-activating gene (RAG) nuclease and joining of DNA double strand breaks (DSBs) by components of the nonhomologous end joining (NHEJ) pathway. Deficiencies for NHEJ factors can result in immunodeficiency and a propensity to accumulate genomic instability, thus highlighting the importance of identifying all players in this process and deciphering their functions. Bcl2 transgenic v-Abl kinase-transformed pro-B cells provide a pseudo-physiological cellular system to study V(D)J recombination. Treatment of v-Abl/Bcl2 pro-B cells with the Abl kinase inhibitor Imatinib leads to G1 cell cycle arrest, the rapid induction of Rag1/2 gene expression and V(D)J recombination. In this system, the Bcl2 transgene alleviates Imatinib-induced apoptosis enabling the analysis of induced V(D)J recombination. Although powerful, the use of mouse models carrying the Bcl2 transgene for the generation of v-Abl pro-B cell lines is time and money consuming. Here, we describe a method for generating v-Abl/Bcl2 pro-B cell lines from wild type mice and for performing gene knock-out using episomal CRISPR/Cas9 targeting vectors. Using this approach, we generated distinct NHEJ-deficient pro-B cell lines and quantified V(D)J recombination levels in these cells. Furthermore, this methodology can be adapted to generate pro-B cell lines deficient for any gene suspected to play a role in V(D)J recombination, and more generally DSB repair. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Methylation profiling of Epstein-Barr virus immediate-early gene promoters, BZLF1 and BRLF1 in tumors of epithelial, NK- and B-cell origins

    Directory of Open Access Journals (Sweden)

    Li Lili

    2012-03-01

    Full Text Available Abstract Background Epstein-Barr virus (EBV establishes its latency in EBV-associated malignancies, accompanied by occasionally reactivated lytic cycle. Promoter CpG methylation of EBV genome plays an essential role in maintaining viral latency. Two immediate-early (IE genes, BZLF1 and BRLF1, induce the switch from latent to lytic infection. Studies of methylation-dependent binding of BZLF1 and BRLF1 to EBV promoters have been well reported, but little is known about the methylation status of BZLF1 and BRLF1 promoters (Zp and Rp in tumor samples. Methods We evaluated the methylation profiles of Zp and Rp by methylation-specific PCR (MSP and bisulfite genomic sequencing (BGS, as well as BZLF1 and BRLF1 expression by semiquantitative reverse transcription (RT-PCR in tumors of epithelial, NK- and B-cell origins. Results We found that both Zp and Rp were hypermethylated in all studied EBV-positive cell lines and tumors of lymphoid (B- or NK cell or epithelial origin, while unmethylated Zp and Rp alleles were detected in cell lines expressing BZLF1 and BRLF1. Following azacytidine treatment or combined with trichostatin A (TSA, the expression of BZLF1 and BRLF1 was restored along with concomitant promoter demethylation, which subsequently induced the reactivation of early lytic gene BHRF1 and late lytic gene BLLF1. Conclusions Hypermethylation of Zp and Rp mediates the frequent silencing of BZLF1 and BRLF1 in EBV-associated tumors, which could be reactivated by demethylation agent and ultimately initiated the EBV lytic cascade.

  6. B-cell translocation gene 3 overexpression inhibits proliferation and invasion of colorectal cancer SW480 cells via Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Mao, D; Qiao, L; Lu, H; Feng, Y

    2016-01-01

    Increasing evidences have shown that B-cell translocation gene 3 (BTG3) inhibits metastasis of multiple cancer cells. However, the role of BTG3 in colorectal cancer (CRC) and its possible mechanism have not yet been reported. In our study, we evaluated BTG3 expression in several CRC cell lines. Then, pcDNA3.1-BTG3 was transfected into SW480 cells. We found that BTG3 was upregulated in SW480 cells after overexpression plasmid transfection. BTG3 overexpression significantly inhibited cell growth and decreased PCNA (proliferating cell nuclear antigen) and Ki67 levels. BTG3 overexpression markedly downregulated Cyclin D1 and Cyclin E1 levels, whereas elevated p27. Overexpression of BTG3 arrested the cell cycle at G1 phase, which was abrogated by p27 silencing. Furthermore, migration, invasion and EMT of SW480 cells were significantly suppressed by BTG3 overexpression. Further investigations showed the inhibition of Wnt/β-catenin signaling pathway. We then used GSK3β specific inhibitor SB-216763 to activate the Wnt/β-catenin signaling pathway. We found that Wnt/β-catenin signaling pathway activation reversed the effect of BTG3 overexpression on cell proliferation, cell cycle progression, invasion and EMT. In conclusion, BTG3 overexpression inhibited cell growth, induced cell cycle arrest and suppressed the metastasis of SW480 cells via the Wnt/β-catenin signaling pathway. BTG3 may be considered as a therapeutic target in CRC treatment.

  7. [Application of Combined Detection of Fusion Gene and BIOMED-2 Standardized Ig Gene Rearrangement System in Childhood B-cell Acute Lymphoblastic Leukemia].

    Science.gov (United States)

    Ai, Xiao-Fei; Zhang, Yan; Shi, Xin-Rong; Zheng, Ying-Chun; Zhang, Li; Wang, Xiao-Jing; Li, Qing-Hua

    2016-04-01

    To explore the application of combined detection of fusion gene and BIOMED-2 standardized immunoglobulin (Ig) gene rearrangement system in diagnosis and treatment of children with acute lymphoblastic leukemia (ALL). Multiplex-PCR amplifications and RQ-PCR of RNA/DNA were performed using ALL fusion gene detection kit and BIOMED-2 primer. The Ig gene rearrangements were analyzed by using PCR fragment analysis system. Out of 251 children with B-ALL, 77 cases were TEL-AML1(+) , 28 cases were E2A-PBX1(+) , 10 cases were MLL-AF4(+) , 11 cases were BCR-ABL(+) , the total positive rate was 50.2%, 82.5% showed IgH VH-JH rearrangement, 53.4% showed IgK rearrangement. The positive rate of combined detection of fusion gene and gene rearrangement was 99%. E2A-PBX1(+) and MLL-AF4(+) with IgK(+) gene rearrangement group was compared with negative control group, the difference was statistically significant (P < 0.001 or P = 0.005); 105 ALL fusion gene positive cases had been detected by fluorescence in situ hybridization (FISH) simultaneously, the accordance rate of fusion gene and FISH was more than 94%. The combined detection of ALL fusion gene and BIOMED-2 standardized clonality analysis system can improve the positive detected rate of B-ALL dramatically, and make the grouping of disease prognosis more accurately; this combined detection is a more faster and sensitive method than FISH.

  8. Transcriptional circuits in B cell transformation.

    Science.gov (United States)

    Hu, Yeguang; Yoshida, Toshimi; Georgopoulos, Katia

    2017-07-01

    Loss of IKAROS in committed B cell precursors causes a block in differentiation while at the same time augments aberrant cellular properties, such as bone marrow stromal adhesion, self-renewal and resistance to glucocorticoid-mediated cell death. B cell acute lymphoblastic leukaemias originating from these early stages of B cell differentiation and associated with IKAROS mutations share a high-risk cellular phenotype suggesting that deregulation of IKAROS-based mechanisms cause a highly malignant disease process. Recent studies show that IKAROS is critical for the activity of super-enhancers at genes required for pre-B cell receptor (BCR) signalling and differentiation, working either downstream of or in parallel with B cell master regulators such as EBF1 and PAX5. IKAROS also directly represses a cryptic regulatory network of transcription factors prevalent in mesenchymal and epithelial precursors that includes YAP1, TEAD1/2, LHX2 and LMO2, and their targets, which are not normally expressed in lymphocytes. IKAROS prevents not only expression of these 'extra-lineage' transcription factors but also their cooperation with endogenous B cell master regulators, such as EBF1 and PAX5, leading to the formation of a de novo for lymphocytes super-enhancer network. IKAROS coordinates with the Polycomb repression complex (PRC2) to provide stable repression of associated genes during B cell development. However, induction of regulatory factors normally repressed by IKAROS starts a feed-forward loop that activates de-novo enhancers and elevates them to super-enhancer status, thereby diminishing PRC2 repression and awakening aberrant epithelial-like cell properties in B cell precursors. Insight into IKAROS-based transcriptional circuits not only sets new paradigms for cell differentiation but also provides new approaches for classifying and treating high-risk human B-ALL that originates from these early stages of B cell differentiation.

  9. Evaluation diagnostic usefulness of immunoglobulin light chains (Igκ, Igλ) and incomplete IGH D-J clonal gene rearrangements in patients with B-cell non-Hodgkin lymphomas using BIOMED-2 protocol.

    Science.gov (United States)

    Ghorbian, S; Jahanzad, I; Javadi, G R; Sakhinia, E

    2014-11-01

    Evaluation diagnostic usefulness of immunoglobulin light chains (Igκ, Igλ) and incomplete IGH D-J clonal gene rearrangements in formalin-fixed, paraffin-embedded (FFPE) tissue of patients with B-cell non-Hodgkin lymphomas (B-NHL). This study was performed on samples from 70 patients with B-NHL, including two cases of follicular lymphoma (FL), 20 cases of diffuse large B-cell lymphoma (DLBCL), one case of mantle cell lymphoma (MCL), and 47 cases of B-cell neoplasm (non-classified), which had been previously assessed for complete IGH clonality, and failure to clarify gene rearrangements. We used a gold standard multiplex PCR protocol provided by European Biomedicine and Health (BIOMED-2) Concerted Action Project BMH4-CT98-3936 for improvement of diagnosis and analysis of clonality gene rearrangement in lymphoma malignancies. Our results revealed a total positive monoclonality of 89 % (62/70) in Igκ, Igλ, and 11.4 % (8/70) polyclonality in gene rearrangements assay. The samples with positive clonality consisting (Igκ: 45 %, Igλ: 55 %) in DLBCL, (Igκ: 100 %) in FL, (Igλ: 100 %) in MCL, and (Igκ: 47 %, Igλ: 36 %) in B-cell neoplasm non-classified. None of the incomplete IGH D-J immunoglobulin gene families (0 %) showed monoclonality, and all samples demonstrated polyclonality pattern. Our findings on FFPE tissue revealed that immunoglobulin light chains clonality gene rearrangements assays using BIOMED-2 protocol, could be considered a valuable and reliable method for clonality detection, particularly in cases of failure of complete IGH gene rearrangements analysis. Clonal Ig gene rearrangements assay is applicable for routine diagnostic testing of lymphoproliferative disorders and as a reliable method for differentiating between malignant and benign lymphoma disorders.

  10. Generation of stable monoclonal antibody-producing B cell receptor-positive human memory B cells by genetic programming

    NARCIS (Netherlands)

    Kwakkenbos, Mark J.; Diehl, Sean A.; Yasuda, Etsuko; Bakker, Arjen Q.; van Geelen, Caroline M. M.; Lukens, Michaël; van Bleek, Grada M.; Widjojoatmodjo, Myra N.; Bogers, Willy M. J. M.; Mei, Henrik; Radbruch, Andreas; Scheeren, Ferenc A.; Spits, Hergen; Beaumont, Tim

    The B cell lymphoma-6 (Bcl-6) and Bcl-xL proteins are expressed in germinal center B cells and enable them to endure the proliferative and mutagenic environment of the germinal center. By introducing these genes into peripheral blood memory B cells and culturing these cells with two factors produced

  11. Generation of stable monoclonal antibody-producing B cell receptor-positive human memory B cells by genetic programming

    NARCIS (Netherlands)

    Kwakkenbos, Mark J.; Diehl, Sean A.; Yasuda, Etsuko; Bakker, Arjen Q.; van Geelen, Caroline M. M.; Lukens, Michaël V.; van Bleek, Grada M.; Widjojoatmodjo, Myra N.; Bogers, Willy M. J. M.; Mei, Henrik; Radbruch, Andreas; Scheeren, Ferenc A.; Spits, Hergen; Beaumont, Tim

    2010-01-01

    The B cell lymphoma-6 (Bcl-6) and Bcl-xL proteins are expressed in germinal center B cells and enable them to endure the proliferative and mutagenic environment of the germinal center. By introducing these genes into peripheral blood memory B cells and culturing these cells with two factors produced

  12. Immunoglobulin γ light-chain-related genes 14.1 and 16.1 are expressed in pre-B cells and may encode the human immunoglobulin ω light-chain protein

    International Nuclear Information System (INIS)

    Hollis, G.F.; Evans, R.J.; Stafford-Hollis, J.M.; Korsmeyer, S.J.; McKearn, J.P.

    1989-01-01

    Human pre-B cells, which produce immunoglobulin heavy chain but do not produce immunoglobulin light chain, are shown to contain a 1-kilobase transcript homologous to immunoglobulin λ light-chain genes. Detailed analysis of RNA and cDNA clones derived from these transcripts reveals that they originate from the distinct immunoglobulin λ-like genes 14.1/16.1. Sequence analysis of these clones reveals a long open reading frame, beginning with an ATG, capable of encoding a protein of 214 amino acids with an unprocessed molecular weight of 22,944. The C-terminal half of this predicted protein is highly homologous to immunoglobulin λ light-chain joining and constant region protein sequence, while the amino-terminal end does not share homology with variable regions. Antisera raised against a peptide whose sequence was predicted from the 14.1 cDNA sequence identifies a 22-kDa protein in human pre-B cells. Immunoprecipitation of immunoglobulin μ-chain from these pre-B cells with anti-immunoglobulin μ antibody coprecipitates a 22-kDa protein, which is a candidate for the human immunoglobulin ω light-chain protein and may be the protein product of the 14.1/16.1 genes

  13. Establishment and maintenance of B cell identity.

    Science.gov (United States)

    Grosschedl, Rudolf

    2013-01-01

    B lymphocyte differentiation is dependent on an intricate interplay of transcription factors and signaling pathways to establish a lineage-specific program of gene expression. Functional perturbations of several transcription factors by gain- or loss-of-function experiments indicated that E2A, EBF1, and FoxO1 are required for the specification of the B cell lineage, whereas Pax5 antagonizes alternative cell fates by repressing genes that allow for responsiveness to T lymphoid- and myeloid-promoting signals. However, genome-wide analysis of EBF1-binding sites and their functional interrogation indicated that EBF1 is involved in both activation of the B cell program and repression of alternative cell fates. Recent studies indicate that EBF1 function is required throughout the B cell lineage until the onset of plasma cell differentiation and includes a role in the maintenance of B cell identity. Thus, early B cell differentiation requires intertwined networks of transcription factors in which EBF1 collaborates with E2A and FoxO1 to activate the B lineage program and acts together with Pax5 to antagonize alternative cell fates. Copyright © 2013 Cold Spring Harbor Laboratory Press; all rights reserved.

  14. Foxp1 controls mature B cell survival and the development of follicular and B-1 B cells

    Science.gov (United States)

    Patzelt, Thomas; Keppler, Selina J.; Gorka, Oliver; Thoene, Silvia; Wartewig, Tim; Reth, Michael; Förster, Irmgard; Lang, Roland; Buchner, Maike; Ruland, Jürgen

    2018-01-01

    The transcription factor Foxp1 is critical for early B cell development. Despite frequent deregulation of Foxp1 in B cell lymphoma, the physiological functions of Foxp1 in mature B cells remain unknown. Here, we used conditional gene targeting in the B cell lineage and report that Foxp1 disruption in developing and mature B cells results in reduced numbers and frequencies of follicular and B-1 B cells and in impaired antibody production upon T cell-independent immunization in vivo. Moreover, Foxp1-deficient B cells are impaired in survival even though they exhibit an increased capacity to proliferate. Transcriptional analysis identified defective expression of the prosurvival Bcl-2 family gene Bcl2l1 encoding Bcl-xl in Foxp1-deficient B cells, and we identified Foxp1 binding in the regulatory region of Bcl2l1. Transgenic overexpression of Bcl2 rescued the survival defect in Foxp1-deficient mature B cells in vivo and restored peripheral B cell numbers. Thus, our results identify Foxp1 as a physiological regulator of mature B cell survival mediated in part via the control of Bcl-xl expression and imply that this pathway might contribute to the pathogenic function of aberrant Foxp1 expression in lymphoma. PMID:29507226

  15. JCAR014 and Durvalumab in Treating Patients With Relapsed or Refractory B-cell Non-Hodgkin Lymphoma

    Science.gov (United States)

    2018-04-02

    BCL2 Gene Rearrangement; BCL6 Gene Rearrangement; CD19 Positive; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; High-Grade B-Cell Lymphoma With MYC, BCL2, and BCL6 Rearrangements; MYC Gene Rearrangement; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma

  16. Memory B Cells of Mice and Humans.

    Science.gov (United States)

    Weisel, Florian; Shlomchik, Mark

    2017-04-26

    We comprehensively review memory B cells (MBCs), covering the definition of MBCs and their identities and subsets, how MBCs are generated, where they are localized, how they are maintained, and how they are reactivated. Whereas naive B cells adopt multiple fates upon stimulation, MBCs are more restricted in their responses. Evolving work reveals that the MBC compartment in mice and humans consists of distinct subpopulations with differing effector functions. We discuss the various approaches to define subsets and subset-specific roles. A major theme is the need to both deliver faster effector function upon reexposure and readapt to antigenically variant pathogens while avoiding burnout, which would be the result if all MBCs generated only terminal effector function. We discuss cell-intrinsic differences in gene expression and signaling that underlie differences in function between MBCs and naive B cells and among MBC subsets and how this leads to memory responses.

  17. B Cell Subsets in Atherosclerosis

    OpenAIRE

    Perry, Heather M.; Bender, Timothy P.; McNamara, Coleen A.

    2012-01-01

    Atherosclerosis, the underlying cause of heart attacks and strokes, is a chronic inflammatory disease of the artery wall. Immune cells, including lymphocytes modulate atherosclerotic lesion development through interconnected mechanisms. Elegant studies over the past decades have begun to unravel a role for B cells in atherosclerosis. Recent findings provide evidence that B cell effects on atherosclerosis may be subset-dependent. B-1a B cells have been reported to protect from atherosclerosis ...

  18. VDJ-Seq: Deep Sequencing Analysis of Rearranged Immunoglobulin Heavy Chain Gene to Reveal Clonal Evolution Patterns of B Cell Lymphoma.

    Science.gov (United States)

    Jiang, Yanwen; Nie, Kui; Redmond, David; Melnick, Ari M; Tam, Wayne; Elemento, Olivier

    2015-12-28

    Understanding tumor clonality is critical to understanding the mechanisms involved in tumorigenesis and disease progression. In addition, understanding the clonal composition changes that occur within a tumor in response to certain micro-environment or treatments may lead to the design of more sophisticated and effective approaches to eradicate tumor cells. However, tracking tumor clonal sub-populations has been challenging due to the lack of distinguishable markers. To address this problem, a VDJ-seq protocol was created to trace the clonal evolution patterns of diffuse large B cell lymphoma (DLBCL) relapse by exploiting VDJ recombination and somatic hypermutation (SHM), two unique features of B cell lymphomas. In this protocol, Next-Generation sequencing (NGS) libraries with indexing potential were constructed from amplified rearranged immunoglobulin heavy chain (IgH) VDJ region from pairs of primary diagnosis and relapse DLBCL samples. On average more than half million VDJ sequences per sample were obtained after sequencing, which contain both VDJ rearrangement and SHM information. In addition, customized bioinformatics pipelines were developed to fully utilize sequence information for the characterization of IgH-VDJ repertoire within these samples. Furthermore, the pipeline allows the reconstruction and comparison of the clonal architecture of individual tumors, which enables the examination of the clonal heterogeneity within the diagnosis tumors and deduction of clonal evolution patterns between diagnosis and relapse tumor pairs. When applying this analysis to several diagnosis-relapse pairs, we uncovered key evidence that multiple distinctive tumor evolutionary patterns could lead to DLBCL relapse. Additionally, this approach can be expanded into other clinical aspects, such as identification of minimal residual disease, monitoring relapse progress and treatment response, and investigation of immune repertoires in non-lymphoma contexts.

  19. B Cells in Autoimmune Diseases

    OpenAIRE

    Hampe, Christiane S.

    2012-01-01

    The role of B cells in autoimmune diseases involves different cellular functions, including the well-established secretion of autoantibodies, autoantigen presentation and ensuing reciprocal interactions with T cells, secretion of inflammatory cytokines, and the generation of ectopic germinal centers. Through these mechanisms B cells are involved both in autoimmune diseases that are traditionally viewed as antibody mediated and also in autoimmune diseases that are commonly classified as T cell...

  20. Innate IgG molecules and innate B cells expressed by immunoglobulin constant heavy G chain (Fcγ) genetic marker genes are involved in the 'allergic march' of IgE sensitization in children.

    Science.gov (United States)

    Oxelius, Vivi-Anne; Krueger, Renate; Ahlstedt, Staffan; Keil, Thomas; Lau, Susanne; Wahn, Ulrich

    2015-01-01

    Interindividual variations of immunoglobulin constant heavy G chain (IGHG) genes on chromosome 14q32.3 are identified by alternative genetic markers (GM) of IgG3, IgG1 and IgG2, respectively. They express structurally and functionally innate IgG molecules and B cells, associated with allergic disease, replicated in several studies. 1-year-old and 10-year-old, IgE-sensitized and non-sensitized children from the German Multicenter Allergy Study birth cohort were assessed by new serological methods for the mendelian IGHG (Fcγ) (GM) genes, as innate IgG molecules and innate B cells. Food allergy sensitization in thirty-five 1-year-old children (124 not sensitized) was associated with the IGHG*bfn haplotype and B*(bfn) cells (OR 1.9, 95% CI 1.2-3.1; p = 0.010). Aeroallergen sensitization in ninety-nine 10-year-old children (95 not sensitized) was associated with the same genes (OR 1.4, 95% CI 1.02-1.9; p = 0.034). The IgE sensitization was most prominent in the restrictive homozygous IGHG*bfn/*bfn diplotype, 34% at age 1, increasing to 60% at age 10, rating the highest numbers of positive IgE tests, expressing increased levels of IgE and innate IgG2*n. The IGHG*bfn haplotype (B*(bfn) cells) and increased innate IgG2*n levels are predictive factors for IgE sensitization in childhood. IGHG genes can be assessed for prognostic and preventive purposes in clinical care. © 2015 S. Karger AG, Basel.

  1. Protocol for qRT-PCR analysis from formalin fixed paraffin embedded tissue sections from diffuse large b-cell lymphoma: Validation of the six-gene predictor score

    Science.gov (United States)

    Tekin, Nilgun; Conget, Paulette; Bruna, Flavia; Timar, Botond; Gagyi, Eva; Basak, Ranjan; Naik, Omkar; Auewarakul, Chirayu; Sritana, Narongrit; Levy, Debora; Cerci, Juliano Julio; Bydlowski, Sergio Paulo; Pereira, Juliana; Dimamay, Mark Pierre; Natividad, Filipinas; Chung, June-Key; Belder, Nevin; Kuzu, Isinsu; Paez, Diana; Dondi, Maurizio; Carr, Robert

    2016-01-01

    As a part of an international study on the molecular analysis of Diffuse Large B-cell Lymphoma (DLBCL), a robust protocol for gene expression analysis from RNA extraction to qRT-PCR using Formalin Fixed Paraffin Embedded tissues was developed. Here a study was conducted to define a strategy to validate the previously reported 6-gene (LMO2, BCL6, FN1, CCND2, SCYA3 and BCL2) model as predictor of prognosis in DLBCL. To avoid variation, all samples were tested in a single centre and single platform. This study comprised 8 countries (Brazil, Chile, Hungary, India, Philippines, S. Korea, Thailand and Turkey). Using the Kaplan-Meier and log rank test on patients (n=162) and two mortality risk groups (with those above and below the mean representing high and low risk groups) confirmed that the 6-gene predictor score correlates significantly with overall survival (OS, p<0.01) but not with event free survival (EFS, p=0.18). Adding the International Prognostic Index (IPI) shows that the 6-gene predictor score correlates significantly with high IPI scores for OS (p<0.05), whereas those with low IPI scores show a trend not reaching significance (p=0.08). This study defined an effective and economical qRT-PCR strategy and validated the 6-gene score as a predictor of OS in an international setting. PMID:27825111

  2. Zebrafish B Cell Development without a Pre-B Cell Stage, Revealed by CD79 Fluorescence Reporter Transgenes.

    Science.gov (United States)

    Liu, Xingjun; Li, Yue-Sheng; Shinton, Susan A; Rhodes, Jennifer; Tang, Lingjuan; Feng, Hui; Jette, Cicely A; Look, A Thomas; Hayakawa, Kyoko; Hardy, Richard R

    2017-09-01

    CD79a and CD79b proteins associate with Ig receptors as integral signaling components of the B cell Ag receptor complex. To study B cell development in zebrafish, we isolated orthologs of these genes and performed in situ hybridization, finding that their expression colocalized with IgH-μ in the kidney, which is the site of B cell development. CD79 transgenic lines were made by linking the promoter and upstream regulatory segments of CD79a and CD79b to enhanced GFP to identify B cells, as demonstrated by PCR analysis of IgH-μ expression in sorted cells. We crossed these CD79-GFP lines to a recombination activating gene (Rag)2:mCherry transgenic line to identify B cell development stages in kidney marrow. Initiation of CD79:GFP expression in Rag2:mCherry + cells and the timing of Ig H and L chain expression revealed simultaneous expression of both IgH-μ- and IgL-κ-chains, without progressing through the stage of IgH-μ-chain alone. Rag2:mCherry + cells without CD79:GFP showed the highest Rag1 and Rag2 mRNAs compared with CD79a and CD79b:GFP + B cells, which showed strongly reduced Rag mRNAs. Thus, B cell development in zebrafish does not go through a Rag hi CD79 + IgH-μ + pre-B cell stage, different from mammals. After the generation of CD79:GFP + B cells, decreased CD79 expression occurred upon differentiation to Ig secretion, as detected by alteration from membrane to secreted IgH-μ exon usage, similar to in mammals. This confirmed a conserved role for CD79 in B cell development and differentiation, without the requirement of a pre-B cell stage in zebrafish. Copyright © 2017 by The American Association of Immunologists, Inc.

  3. Defining B Cell Chromatin: Lessons from EBF1.

    Science.gov (United States)

    Boller, Sören; Li, Rui; Grosschedl, Rudolf

    2018-04-01

    Hematopoiesis is regulated by signals from the microenvironment, transcription factor networks, and changes of the epigenetic landscape. Transcription factors interact with and shape chromatin to allow for lineage- and cell type-specific changes in gene expression. During B lymphopoiesis, epigenetic regulation is observed in multilineage progenitors in which a specific chromatin context is established, at the onset of the B cell differentiation when early B cell factor 1 (EBF1) induces lineage-specific changes in chromatin, during V(D)J recombination and after antigen-driven activation of B cells and terminal differentiation. In this review, we discuss the epigenetic changes underlying B cell differentiation, focusing on the role of transcription factor EBF1 in B cell lineage priming. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Iodine-131 treatment of thyroid cancer cells leads to suppression of cell proliferation followed by induction of cell apoptosis and cell cycle arrest by regulation of B-cell translocation gene 2-mediated JNK/NF-κB pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.M.; Pang, A.X., E-mail: zhaoliming515@126.com [Department of Nuclear Medicine, Linyi People' s Hospital, Linyi (China); Department of Urology, Linyi People' s Hospital, Linyi (China)

    2017-10-01

    Iodine-131 ({sup 131}I) is widely used for the treatment of thyroid-related diseases. This study aimed to investigate the expression of p53 and BTG2 genes following {sup 131}I therapy in thyroid cancer cell line SW579 and the possible underlying mechanism. SW579 human thyroid squamous carcinoma cells were cultured and treated with {sup 131}I. They were then assessed for {sup 131}I uptake, cell viability, apoptosis, cell cycle arrest, p53 expression, and BTG2 gene expression. SW579 cells were transfected with BTG2 siRNA, p53 siRNA and siNC and were then examined for the same aforementioned parameters. When treated with a JNK inhibitor of SP600125 and {sup 131}I or with a NF-kB inhibitor of BMS-345541 and {sup 131}I, non-transfected SW579 cells were assessed in JNK/NFkB pathways. It was observed that {sup 131}I significantly inhibited cell proliferation, promoted cell apoptosis and cell cycle arrest. Both BTG2 and p53 expression were enhanced in a dose-dependent manner. An increase in cell viability by up-regulation in Bcl2 gene, a decrease in apoptosis by enhanced CDK2 gene expression and a decrease in cell cycle arrest at G{sub 0}/G{sub 1} phase were also observed in SW579 cell lines transfected with silenced BTG2 gene. When treated with SP600125 and {sup 131}I, the non transfected SW579 cell lines significantly inhibited JNK pathway, NF-kB pathway and the expression of BTG2. However, when treated with BMS-345541 and {sup 131}I, only the NF-kB pathway was suppressed. {sup 131}I suppressed cell proliferation, induced cell apoptosis, and promoted cell cycle arrest of thyroid cancer cells by up-regulating B-cell translocation gene 2-mediated activation of JNK/NF--κB pathways. (author)

  5. Invasin of Yersinia pseudotuberculosis activates human peripheral B cells.

    OpenAIRE

    Lundgren, E; Carballeira, N; Vazquez, R; Dubinina, E; Bränden, H; Persson, H; Wolf-Watz, H

    1996-01-01

    The Yersinia pseudotuberculosis cell surface-located protein invasin was found to promote binding between the pathogen and resting peripheral B cells via beta 1 integrin receptors (CD29). B cells responded by expressing several activation markers and by growing, In contrast, T cells did not react, although these cells express CD29. An isogenic invA mutant failed to activate B cells. The mutation could be complemented by providing the invA+ gene in trans. Purified invasin alone did not activat...

  6. Phosphatidylcholine-specific phospholipase C/heat shock protein 70 (Hsp70)/transcription factor B-cell translocation gene 2 signaling in rat bone marrow stromal cell differentiation to cholinergic neuron-like cells.

    Science.gov (United States)

    Shao, Jing; Sun, Chunhui; Su, Le; Zhao, Jing; Zhang, Shangli; Miao, Junying

    2012-12-01

    Although bone marrow stromal cells (BMSCs) can differentiate into neuron-like cells, the mechanisms underlying neuronal differentiation are not well understood. We recently found that inhibition of phosphatidylcholine-specific phospholipase C (PC-PLC) by its inhibitor D609 promoted BMSCs' differentiation into cholinergic neuron-like cells. Using the effective small molecule D609 and gene microarray technology, we investigated the change of gene expression profile to identify key mediators involved in the neuronal differentiation. We selected heat shock protein 70 (Hsp70) and transcription factor B-cell translocation gene 2 (Btg2) that were maximally up-regulated for further study. We found that functional suppression of Hsp70 blocked D609-induced increase of Btg2 expression and cholinergic neuronal differentiation of BMSCs. These results demonstrated that Hsp70 was the pivotal factor in PC-PLC-medicated neuronal differentiation of BMSCs, and Btg2 might be its downstream target. Our findings provide new clues for controlling BMSCs' differentiation into cholinergic neuron-like cells and provide a putative strategy for neurodegenerative diseases therapies. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  7. Regulation of normal B-cell differentiation and malignant B-cell survival by OCT2.

    Science.gov (United States)

    Hodson, Daniel J; Shaffer, Arthur L; Xiao, Wenming; Wright, George W; Schmitz, Roland; Phelan, James D; Yang, Yandan; Webster, Daniel E; Rui, Lixin; Kohlhammer, Holger; Nakagawa, Masao; Waldmann, Thomas A; Staudt, Louis M

    2016-04-05

    The requirement for the B-cell transcription factor OCT2 (octamer-binding protein 2, encoded by Pou2f2) in germinal center B cells has proved controversial. Here, we report that germinal center B cells are formed normally after depletion of OCT2 in a conditional knockout mouse, but their proliferation is reduced and in vivo differentiation to antibody-secreting plasma cells is blocked. This finding led us to examine the role of OCT2 in germinal center-derived lymphomas. shRNA knockdown showed that almost all diffuse large B-cell lymphoma (DLBCL) cell lines are addicted to the expression of OCT2 and its coactivator OCA-B. Genome-wide chromatin immunoprecipitation (ChIP) analysis and gene-expression profiling revealed the broad transcriptional program regulated by OCT2 that includes the expression of STAT3, IL-10, ELL2, XBP1, MYC, TERT, and ADA. Importantly, genetic alteration of OCT2 is not a requirement for cellular addiction in DLBCL. However, we detected amplifications of the POU2F2 locus in DLBCL tumor biopsies and a recurrent mutation of threonine 223 in the DNA-binding domain of OCT2. This neomorphic mutation subtly alters the DNA-binding preference of OCT2, leading to the transactivation of noncanonical target genes including HIF1a and FCRL3 Finally, by introducing mutations designed to disrupt the OCT2-OCA-B interface, we reveal a requirement for this protein-protein interface that ultimately might be exploited therapeutically. Our findings, combined with the predominantly B-cell-restricted expression of OCT2 and the absence of a systemic phenotype in our knockout mice, suggest that an OCT2-targeted therapeutic strategy would be efficacious in both major subtypes of DLBCL while avoiding systemic toxicity.

  8. 'Big bang' of B-cell development revealed.

    Science.gov (United States)

    Murre, Cornelis

    2018-01-15

    Earlier studies have identified transcription factors that specify B-cell fate, but the underlying mechanisms remain to be revealed. Two new studies by Miyai and colleagues (pp. 112-126) and Li and colleagues (pp. 96-111) in this issue of Genes & Development provide new and unprecedented insights into the genetic and epigenetic mechanisms that establish B-cell identity. © 2018 Murre; Published by Cold Spring Harbor Laboratory Press.

  9. Association of germline genetic variants in RFC, IL15 and VDR genes with minimal residual disease in pediatric B-cell precursor ALL.

    Science.gov (United States)

    Dawidowska, Małgorzata; Kosmalska, Maria; Sędek, Łukasz; Szczepankiewicz, Aleksandra; Twardoch, Magdalena; Sonsala, Alicja; Szarzyńska-Zawadzka, Bronisława; Derwich, Katarzyna; Lejman, Monika; Pawelec, Katarzyna; Obitko-Płudowska, Agnieszka; Pawińska-Wąsikowska, Katarzyna; Kwiecińska, Kinga; Kołtan, Andrzej; Dyla, Agnieszka; Grzeszczak, Władysław; Kowalczyk, Jerzy R; Szczepański, Tomasz; Ziętkiewicz, Ewa; Witt, Michał

    2016-07-18

    Minimal residual disease (MRD) enables reliable assessment of risk in acute lymphoblastic leukemia (ALL). However, little is known on association between MRD status and germline genetic variation. We examined 159 Caucasian (Slavic) patients with pediatric ALL, treated according to ALL-IC-BFM 2002/2009 protocols, in search for association between 23 germline polymorphisms and MRD status at day 15, day 33 and week 12, with adjustment for MRD-associated clinical covariates. Three variants were significantly associated with MRD: rs1544410 in VDR (MRD-day15); rs1051266 in RFC (MRD-day33, MRD-week12), independently and in an additive effect with rs10519613 in IL15 (MRD-day33). The risk alleles for MRD-positivity were: A allele of VDR (OR = 2.37, 95%CI = 1.07-5.21, P = 0.03, MRD-day15); A of RFC (OR = 1.93, 95%CI = 1.05-3.52, P = 0.03, MRD-day33 and MRD-week12, P RFC and IL15 loci than in patients with risk alleles in one locus or no risk alleles: 2 vs. 1 (OR = 3.94, 95% CI = 1.28-12.11, P = 0.024), 2 vs. 0 (OR = 6.75, 95% CI = 1.61-28.39, P = 0.012). Germline variation in genes related to pharmacokinetics/pharmacodynamics of anti-leukemic drugs and to anti-tumor immunity of the host is associated with MRD status and might help improve risk assessment in ALL.

  10. Essential role of EBF1 in the generation and function of distinct mature B cell types.

    Science.gov (United States)

    Vilagos, Bojan; Hoffmann, Mareike; Souabni, Abdallah; Sun, Qiong; Werner, Barbara; Medvedovic, Jasna; Bilic, Ivan; Minnich, Martina; Axelsson, Elin; Jaritz, Markus; Busslinger, Meinrad

    2012-04-09

    The transcription factor EBF1 is essential for lineage specification in early B cell development. In this study, we demonstrate by conditional mutagenesis that EBF1 is required for B cell commitment, pro-B cell development, and subsequent transition to the pre-B cell stage. Later in B cell development, EBF1 was essential for the generation and maintenance of several mature B cell types. Marginal zone and B-1 B cells were lost, whereas follicular (FO) and germinal center (GC) B cells were reduced in the absence of EBF1. Activation of the B cell receptor resulted in impaired intracellular signaling, proliferation and survival of EBF1-deficient FO B cells. Immune responses were severely reduced upon Ebf1 inactivation, as GCs were formed but not maintained. ChIP- and RNA-sequencing of FO B cells identified EBF1-activated genes that encode receptors, signal transducers, and transcriptional regulators implicated in B cell signaling. Notably, ectopic expression of EBF1 efficiently induced the development of B-1 cells at the expense of conventional B cells. These gain- and loss-of-function analyses uncovered novel important functions of EBF1 in controlling B cell immunity.

  11. B cells in operational tolerance.

    Science.gov (United States)

    Chesneau, M; Danger, R; Soulillou, J-P; Brouard, S

    2018-02-16

    Transplantation is currently the therapy of choice for endstage organ failure even though it requires long-term immunosuppresive therapy, with its numerous side effects, for acceptance of the transplanted organ. In rare cases however, patients develop operational tolerance, that is, graft survival without immunosuppression. Studies conducted on these patients reveal genetic, phenotypic, and functional signatures. They provide a better understanding of the immunological mechanisms involved in operational tolerance and define biomarkers that could be used to adapt immunosuppressive treatment to the individual, safely reduce immunosuppression doses, and ideally and safely guide immunosuppression withdrawal. This review summarizes studies that suggest a role for B cells as biomarkers of operational tolerance and discusses the use of B cells as a predictive tool for immunologic risk. Copyright © 2018. Published by Elsevier Inc.

  12. Regulation of B cell development by posttranslational modification of Ebf1

    OpenAIRE

    Wang, Qiongman

    2016-01-01

    Early B cell differentiation is regulated via a complex transcriptional network. Ebf1 is a central part of it, regulating around 3000 target genes associated with B cell function. Among these target genes, Ebf1 plays diverse roles to activate, repress or poise gene expression. Post-translational modification represents a potential explanation for these diverse roles. Specifically, phosphorylation of Ebf1 might contribute to the diverse functions of Ebf1 during B cell development. The hypot...

  13. Long Noncoding RNA Expression during Human B-Cell Development.

    Directory of Open Access Journals (Sweden)

    Andreas Petri

    Full Text Available Long noncoding RNAs (lncRNAs have emerged as important regulators of diverse cellular processes, but their roles in the developing immune system are poorly understood. In this study, we analysed lncRNA expression during human B-cell development by array-based expression profiling of eleven distinct flow-sorted B-cell subsets, comprising pre-B1, pre-B2, immature, naive, memory, and plasma cells from bone marrow biopsies (n = 7, and naive, centroblast, centrocyte, memory, and plasmablast cells from tonsil tissue samples (n = 6, respectively. A remapping strategy was used to assign the array probes to 37630 gene-level probe sets, reflecting recent updates in genomic and transcriptomic databases, which enabled expression profiling of 19579 long noncoding RNAs, comprising 3947 antisense RNAs, 5277 lincRNAs, 7625 pseudogenes, and 2730 additional lncRNAs. As a first step towards inferring the functions of the identified lncRNAs in developing B-cells, we analysed their co-expression with well-characterized protein-coding genes, a method known as "guilt by association". By using weighted gene co-expression network analysis, we identified 272 lincRNAs, 471 antisense RNAs, 376 pseudogene RNAs, and 64 lncRNAs within seven sub-networks associated with distinct stages of B-cell development, such as early B-cell development, B-cell proliferation, affinity maturation of antibody, and terminal differentiation. These data provide an important resource for future studies on the functions of lncRNAs in development of the adaptive immune response, and the pathogenesis of B-cell malignancies that originate from distinct B-cell subpopulations.

  14. The small FOXP1 isoform predominantly expressed in activated B cell-like diffuse large B-cell lymphoma and full-length FOXP1 exert similar oncogenic and transcriptional activity in human B cells.

    Science.gov (United States)

    van Keimpema, Martine; Grüneberg, Leonie J; Schilder-Tol, Esther J M; Oud, Monique E C M; Beuling, Esther A; Hensbergen, Paul J; de Jong, Johann; Pals, Steven T; Spaargaren, Marcel

    2017-03-01

    The forkhead transcription factor FOXP1 is generally regarded as an oncogene in activated B cell-like diffuse large B-cell lymphoma. Previous studies have suggested that a small isoform of FOXP1 rather than full-length FOXP1, may possess this oncogenic activity. Corroborating those studies, we herein show that activated B cell-like diffuse large B-cell lymphoma cell lines and primary activated B cell-like diffuse large B-cell lymphoma cells predominantly express a small FOXP1 isoform, and that the 5'-end of the Foxp1 gene is a common insertion site in murine lymphomas in leukemia virus- and transposon-mediated insertional mutagenesis screens. By combined mass spectrometry, (quantative) reverse transcription polymerase chain reaction/sequencing, and small interfering ribonucleic acid-mediated gene silencing, we determined that the small FOXP1 isoform predominantly expressed in activated B cell-like diffuse large B-cell lymphoma lacks the N-terminal 100 amino acids of full-length FOXP1. Aberrant overexpression of this FOXP1 isoform (ΔN100) in primary human B cells revealed its oncogenic capacity; it repressed apoptosis and plasma cell differentiation. However, no difference in potency was found between this small FOXP1 isoform and full-length FOXP1. Furthermore, overexpression of full-length FOXP1 or this small FOXP1 isoform in primary B cells and diffuse large B-cell lymphoma cell lines resulted in similar gene regulation. Taken together, our data indicate that this small FOXP1 isoform and full-length FOXP1 have comparable oncogenic and transcriptional activity in human B cells, suggesting that aberrant expression or overexpression of FOXP1, irrespective of the specific isoform, contributes to lymphomagenesis. These novel insights further enhance the value of FOXP1 for the diagnostics, prognostics, and treatment of diffuse large B-cell lymphoma patients. Copyright© Ferrata Storti Foundation.

  15. Inactivation of the P16INK4/MTS1 gene by a chromosome translocation t(9;14)(p21-22;q11) in an acute lymphoblastic leukemia of B-cell type.

    Science.gov (United States)

    Duro, D; Bernard, O; Della Valle, V; Leblanc, T; Berger, R; Larsen, C J

    1996-02-15

    We have reported previously a preliminary study of a t(9;14)(p21-22; q11) in B-cell acute lymphoblastic leukemia. This translocation had rearranged the TCRA/D locus on chromosome band 14q11 and the locus encoding the tumor suppressor gene P16INK4/MTS1 (P16) on band 9p21 (D. Duro et al., Oncogene, 11: 21-29, 1995). In the present report, the breakpoints were precisely localized on each chromosome partner. On the 14q- derivative, the sequence derived from chromosome 9 was interrupted at 1.0 kb upstream of the first exon of P16, close to a consensus recombination heptamer, CACTGTG. In addition, the chromosome 14 breakpoint was localized at the end of the TCRD2 (delta 2) segment, and 22 residues with unknown origin were present at the translocation junction. On the 9p+ derivative, chromosome 9 sequences were in continuity with those displaced onto chromosome 14, and the 14q11 breakpoint was located within TCRJA29 segment. These features are consistent with aberrant activity of the TCR gene recombinase complex. Although all three coding exons of P16 were displaced onto the chromosome 14q-derivative, no P16 transcript was detected in the leukemic cells. Because the region spanning the P16 exon 1 was not inactivated by methylation and because the other P16 allele was deleted, the implication is that the chromosome breakpoint was likely to disrupt regulatory elements involved in the normal expression of the gene. As a whole, then, our results show that translocations affecting band 9p21 can participate to the inactivation of P16, thus justifying a systematic survey of translocations of the 9p21 band in acute lymphoblastic leukemia.

  16. B cell activating factor (BAFF) selects IL-10-B cells over IL-10+B cells during inflammatory responses.

    Science.gov (United States)

    Ma, Ning; Zhang, Yu; Liu, Qilin; Wang, Zhiding; Liu, Xiaoling; Zhu, Gaizhi; Yu, Dandan; Han, Gencheng; Chen, Guojiang; Hou, Chunmei; Wang, Tianxiao; Ma, Yuanfang; Shen, Beifen; Li, Yan; Xiao, He; Wang, Renxi

    2017-05-01

    B cell activating factor (BAFF) regulates B cell maturation, survival, function, and plays a critical pathogenic role in autoimmune diseases. It remains unclear how BAFF affects IL-10 - B cells versus regulatory B cells (Bregs) in inflammatory responses. In this study, we found that IL-10-expressing Bregs decreased in lupus-prone MRL/lpr mice and experimental allergic encephalomyelitis (EAE) mice. On blockade of the effects of BAFF with TACI-IgG, IL-10 + Bregs were upregulated in MRL/lpr and EAE mice. In addition, BAFF expanded IL-10 + B cells over IL-10 - B cells under noninflammatory conditions in vitro, whereas it expanded IL-10 - B cells over IL-10 + B cells during inflammatory responses, such as stimulation with autoantigen and LPS. Finally, the selection of IL-10 - B cells over IL-10 + B cells by BAFF was dependent on BAFF receptors (BAFFR, TACI, and BCMA) that were upregulated by inflammatory responses. This study suggests that BAFF selects IL-10 - B cells over IL-10 + regulatory B cells via BAFF receptors in inflammatory responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. [Survival of patients with primary central nervous system diffuse large B-cell lymphoma: impact of gene aberrations and protein overexpression of bcl-2 and C-MYC, and selection of chemotherapy regimens].

    Science.gov (United States)

    Yin, W J; Zhu, X; Yang, H Y; Sun, W Y; Wu, M J

    2018-01-08

    Objective: To investigate the impact of clinicopathological features, gene rearrangements and protein expression of bcl-6, bcl-2, C-MYC and chemotherapy regime on the prognosis of patients with primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: Thirty-three cases of PCNS-DLBCL diagnosed from January 2006 to December 2016 at Zhejiang Cancer Hospital were collected. The expression of CD10, bcl-6, bcl-2, MUM1 and MYC were detected by immunohistochemical staining (IHC). The presence of EB virus was detected by in situ hybridization(EBER). Copy number variation (ICN) and translocation status of bcl-6, bcl-2 and C-MYC genes were detected by fluorescence in situ hybridization (FISH). The relationship between the above indexes and the prognosis was analyzed by univariate, bivariate survival analysis and multiple Cox hazard regression analysis. Results: The study included 33 patients of PCNS-DLBCL, without evidence of primary or secondary immunodeficient disease. Male to female ratio was 1.36∶1.00, and the average age was 56 years. Twenty cases had single lesion while 13 had multiple lesions. Deep brain involvement was seen in 12 cases. All patients underwent partial or total tumor resection. Five patients received whole brain post-surgery radiotherapy, nine patients received high-dose methotrexate (HD-MTX) based chemotherapy, and 12 patients received whole-brain radiotherapy combined with HD-MTX based chemotherapy. Severn patients received no further treatment and rituximab was used in 8 patients. According to the Hans model, 27 cases were classified as non-GCB subtypes (81.8%). Bcl-2 was positive in 25 cases (75.8%, 25/33) and highly expressed in 8 (24.2%). MYC was positive in 12 cases (36.4%) and double expression of bcl-2 and MYC was seen in 6 cases. EBER positive rate was 10.0%(3/30), all of which had multiple lesions. Two bcl-6 gene translocations and 3 amplifications were found in 28 patients. Two translocations, 3 ICN or with both

  18. B-cell leukemia/lymphoma panel

    Science.gov (United States)

    ... ency/article/003518.htm B-cell leukemia/lymphoma panel To use the sharing features on this page, please enable JavaScript. B-cell leukemia/lymphoma panel is a blood test that looks for certain ...

  19. Baboon envelope pseudotyped lentiviral vectors efficiently transduce human B cells and allow active factor IX B cell secretion in vivo in NOD/SCIDγc-/-mice.

    Science.gov (United States)

    Levy, C; Fusil, F; Amirache, F; Costa, C; Girard-Gagnepain, A; Negre, D; Bernadin, O; Garaulet, G; Rodriguez, A; Nair, N; Vandendriessche, T; Chuah, M; Cosset, F-L; Verhoeyen, E

    2016-12-01

    Essentials B cells are attractive targets for gene therapy and particularly interesting for immunotherapy. A baboon envelope pseudotyped lentiviral vector (BaEV-LV) was tested for B-cell transduction. BaEV-LVs transduced mature and plasma human B cells with very high efficacy. BaEV-LVs allowed secretion of functional factor IX from B cells at therapeutic levels in vivo. Background B cells are attractive targets for gene therapy for diseases associated with B-cell dysfunction and particularly interesting for immunotherapy. Moreover, B cells are potent protein-secreting cells and can be tolerogenic antigen-presenting cells. Objective Evaluation of human B cells for secretion of clotting factors such as factor IX (FIX) as a possible treatment for hemophilia. Methods We tested here for the first time our newly developed baboon envelope (BaEV) pseudotyped lentiviral vectors (LVs) for human (h) B-cell transduction following their adaptive transfer into an NOD/SCIDγc -/- (NSG) mouse. Results Upon B-cell receptor stimulation, BaEV-LVs transduced up to 80% of hB cells, whereas vesicular stomatitis virus G protein VSV-G-LV only reached 5%. Remarkably, BaEVTR-LVs permitted efficient transduction of 20% of resting naive and 40% of resting memory B cells. Importantly, BaEV-LVs reached up to 100% transduction of human plasmocytes ex vivo. Adoptive transfer of BaEV-LV-transduced mature B cells into NOD/SCID/γc -/- (NSG) [non-obese diabetic (NOD), severe combined immuno-deficiency (SCID)] mice allowed differentiation into plasmablasts and plasma B cells, confirming a sustained high-level gene marking in vivo. As proof of principle, we assessed BaEV-LV for transfer of human factor IX (hFIX) into B cells. BaEV-LVs encoding FIX efficiently transduced hB cells and their transfer into NSG mice demonstrated for the first time secretion of functional hFIX from hB cells at therapeutic levels in vivo. Conclusions The BaEV-LVs might represent a valuable tool for therapeutic protein

  20. Chronic Lymphocytic Leukemia B-Cell Normal Cellular Counterpart: Clues From a Functional Perspective.

    Science.gov (United States)

    Darwiche, Walaa; Gubler, Brigitte; Marolleau, Jean-Pierre; Ghamlouch, Hussein

    2018-01-01

    Chronic lymphocytic leukemia (CLL) is characterized by the clonal expansion of small mature-looking CD19+ CD23+ CD5+ B-cells that accumulate in the blood, bone marrow, and lymphoid organs. To date, no consensus has been reached concerning the normal cellular counterpart of CLL B-cells and several B-cell types have been proposed. CLL B-cells have remarkable phenotypic and gene expression profile homogeneity. In recent years, the molecular and cellular biology of CLL has been enriched by seminal insights that are leading to a better understanding of the natural history of the disease. Immunophenotypic and molecular approaches (including immunoglobulin heavy-chain variable gene mutational status, transcriptional and epigenetic profiling) comparing the normal B-cell subset and CLL B-cells provide some new insights into the normal cellular counterpart. Functional characteristics (including activation requirements and propensity for plasma cell differentiation) of CLL B-cells have now been investigated for 50 years. B-cell subsets differ substantially in terms of their functional features. Analysis of shared functional characteristics may reveal similarities between normal B-cell subsets and CLL B-cells, allowing speculative assignment of a normal cellular counterpart for CLL B-cells. In this review, we summarize current data regarding peripheral B-cell differentiation and human B-cell subsets and suggest possibilities for a normal cellular counterpart based on the functional characteristics of CLL B-cells. However, a definitive normal cellular counterpart cannot be attributed on the basis of the available data. We discuss the functional characteristics required for a cell to be logically considered to be the normal counterpart of CLL B-cells.

  1. B lymphocyte lineage specification, commitment and epigenetic control of transcription by early B cell factor 1.

    Science.gov (United States)

    Hagman, James; Ramírez, Julita; Lukin, Kara

    2012-01-01

    Early B cell factor 1 (EBF1) is a transcription factor that is critical for both B lymphopoiesis and B cell function. EBF1 is a requisite component of the B lymphocyte transcriptional network and is essential for B lineage specification. Recent studies revealed roles for EBF1 in B cell commitment. EBF1 binds its target genes via a DNA-binding domain including a unique 'zinc knuckle', which mediates a novel mode of DNA recognition. Chromatin immunoprecipitation of EBF1 in pro-B cells defined hundreds of new, as well as previously identified, target genes. Notably, expression of the pre-B cell receptor (pre-BCR), BCR and PI3K/Akt/mTOR signaling pathways is controlled by EBF1. In this review, we highlight these current developments and explore how EBF1 functions as a tissue-specific regulator of chromatin structure at B cell-specific genes.

  2. huJCAR014 CAR-T Cells in Treating Adult Patients With Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma or Acute Lymphoblastic Leukemia

    Science.gov (United States)

    2018-03-26

    Adult B Acute Lymphoblastic Leukemia; BCL2 Gene Rearrangement; BCL6 Gene Rearrangement; CD19 Positive; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; MYC Gene Rearrangement; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Adult Acute Lymphoblastic Leukemia; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Transformed Recurrent Non-Hodgkin Lymphoma

  3. HCV Infection and B-Cell Lymphomagenesis

    Directory of Open Access Journals (Sweden)

    Masahiko Ito

    2011-01-01

    Full Text Available Hepatitis C virus (HCV has been recognized as a major cause of chronic liver diseases worldwide. It has been suggested that HCV infects not only hepatocytes but also mononuclear lymphocytes including B cells that express the CD81 molecule, a putative HCV receptor. HCV infection of B cells is the likely cause of B-cell dysregulation disorders such as mixed cryoglobulinemia, rheumatoid factor production, and B-cell lymphoproliferative disorders that may evolve into non-Hodgkin's lymphoma (NHL. Epidemiological data indicate an association between HCV chronic infection and the occurrence of B-cell NHL, suggesting that chronic HCV infection is associated at least in part with B-cell lymphomagenesis. In this paper, we aim to provide an overview of recent literature, including our own, to elucidate a possible role of HCV chronic infection in B-cell lymphomagenesis.

  4. EBI2 overexpression in mice leads to B1 B cell expansion and chronic lymphocytic leukemia-(CLL)-like B cell malignancies

    DEFF Research Database (Denmark)

    Niss Arfelt, Kristine; Barington, Line; Benned-Jensen, Tau

    2017-01-01

    Human and mouse chronic lymphocytic leukemia (CLL) develop from CD5+ B cells that in mice and macaques are known to define the distinct B1a B cell lineage. B1a cells are characterized by lack of germinal center development and the B1a cell population is increased in mice with reduced germinal...... center formation. As a major mediator of follicular B cell migration, the G protein-coupled receptor (GPCR) Epstein Barr virus-induced gene 2 (EBI2 or GPR183) directs B cell migration in the lymphoid follicles in response to its endogenous ligands, oxysterols. Thus, upregulation of EBI2 drives the B...

  5. Intrinsic Plasma Cell Differentiation Defects in B Cell Expansion with NF-κB and T Cell Anergy Patient B Cells

    Directory of Open Access Journals (Sweden)

    Swadhinya Arjunaraja

    2017-08-01

    Full Text Available B cell Expansion with NF-κB and T cell Anergy (BENTA disease is a novel B cell lymphoproliferative disorder caused by germline, gain-of-function mutations in the lymphocyte scaffolding protein CARD11, which drives constitutive NF-κB signaling. Despite dramatic polyclonal expansion of naive and immature B cells, BENTA patients also present with signs of primary immunodeficiency, including markedly reduced percentages of class-switched/memory B cells and poor humoral responses to certain vaccines. Using purified naive B cells from our BENTA patient cohort, here we show that BENTA B cells exhibit intrinsic defects in B cell differentiation. Despite a profound in vitro survival advantage relative to normal donor B cells, BENTA patient B cells were severely impaired in their ability to differentiate into short-lived IgDloCD38hi plasmablasts or CD138+ long-lived plasma cells in response to various stimuli. These defects corresponded with diminished IgG antibody production and correlated with poor induction of specific genes required for plasma cell commitment. These findings provide important mechanistic clues that help explain both B cell lymphocytosis and humoral immunodeficiency in BENTA disease.

  6. Genetic errors of the human caspase recruitment domain-B-cell lymphoma 10-mucosa-associated lymphoid tissue lymphoma-translocation gene 1 (CBM) complex: Molecular, immunologic, and clinical heterogeneity.

    Science.gov (United States)

    Pérez de Diego, Rebeca; Sánchez-Ramón, Silvia; López-Collazo, Eduardo; Martínez-Barricarte, Rubén; Cubillos-Zapata, Carolina; Ferreira Cerdán, Antonio; Casanova, Jean-Laurent; Puel, Anne

    2015-11-01

    Three members of the caspase recruitment domain (CARD) family of adaptors (CARD9, CARD10, and CARD11) are known to form heterotrimers with B-cell lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma-translocation gene 1 (MALT1). These 3 CARD-BCL10-MALT1 (CBM) complexes activate nuclear factor κB in both the innate and adaptive arms of immunity. Human inherited defects of the 3 components of the CBM complex, including the 2 adaptors CARD9 and CARD11 and the 2 core components BCL10 and MALT1, have recently been reported. Biallelic loss-of-function mutant alleles underlie several different immunologic and clinical phenotypes, which can be assigned to 2 distinct categories. Isolated invasive fungal infections of unclear cellular basis are associated with CARD9 deficiency, whereas a broad range of clinical manifestations, including those characteristic of T- and B-lymphocyte defects, are associated with CARD11, MALT1, and BCL10 deficiencies. Interestingly, human subjects with these mutations have some features in common with the corresponding knockout mice, but other features are different between human subjects and mice. Moreover, germline and somatic gain-of-function mutations of MALT1, BCL10, and CARD11 have also been found in patients with other lymphoproliferative disorders. This broad range of germline and somatic CBM lesions, including loss-of-function and gain-of-function mutations, highlights the contribution of each of the components of the CBM complex to human immunity. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  7. Btk at the Pre-B Cell Receptor Checkpoint

    NARCIS (Netherlands)

    S. Middendorp

    2004-01-01

    textabstractSignalling from the BCR or its immature form, the pre-BCR, was shown to be crucial for B cell development. Gene-targeted mice have defined differential roles of components of the (pre-) BCR complex or its downstream signalling pathways. One of the proteins involved in (pre-) BCR

  8. Role of early B-cell factor 1 (EBF1) in Hodgkin lymphoma.

    Science.gov (United States)

    Bohle, V; Döring, C; Hansmann, M-L; Küppers, R

    2013-03-01

    A hallmark of classical Hodgkin lymphoma (cHL) is that the B-cell-derived Hodgkin and Reed-Sternberg (HRS) tumor cells have largely lost the B-cell-typical gene expression program. The factors causing this 'reprogramming' of HRS cells are only partly understood. As early B-cell factor 1 (EBF1), a major B-cell transcription factor, is downregulated in HRS cells, we analyzed whether this downregulation contributes to the lost B-cell phenotype and tested the consequences of EBF1 re-expression in cHL cell lines. EBF1 re-expression caused an upregulation of B-cell genes, such as CD19, CD79A and CD79B, although the B-cell genes FOXO1 and PAX5 remained lowly expressed. The re-expression of CD19, CD79A and CD79B occurred largely without demethylation of promoter CpG motifs of these genes. In the cHL cell line L-1236 fitness decreased after EBF1 re-expression. These data show that EBF1 has the ability to reintroduce part of the B-cell signature in cHL cell lines. Loss of EBF1 expression in HRS cells therefore contributes to their lost B-cell phenotype. Notably, in the cHL cell line KM-H2 destructive mutations were found in one allele of EBF1, indicating that genetic lesions may sometimes have a role in impairing EBF1 expression.

  9. B-cell phenotype and IgD-CD27- memory B cells are affected by TNF-inhibitors and tocilizumab treatment in rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Rita A Moura

    Full Text Available The use of TNF-inhibitors and/or the IL-6 receptor antagonist, tocilizumab, in rheumatoid arthritis (RA have pleiotropic effects that also involve circulating B-cells. The main goal of this study was to assess the effect of TNF-inhibitors and tocilizumab on B-cell phenotype and gene expression in RA.Blood samples were collected from untreated early RA (ERA patients, established RA patients under methotrexate treatment, established RA patients before and after treatment with TNF-inhibitors and tocilizumab, and healthy donors. B-cell subpopulations were characterized by flow cytometry and B-cell gene expression was analyzed by real-time PCR on isolated B-cells. Serum levels of BAFF, CXCL13 and sCD23 were determined by ELISA.The frequency of total CD19+ B cells in circulation was similar between controls and all RA groups, irrespective of treatment, but double negative (DN IgD-CD27- memory B cells were significantly increased in ERA and established RA when compared to controls. Treatment with TNF-inhibitors and tocilizumab restored the frequency of IgD-CD27- B-cells to normal levels, but did not affect other B cell subpopulations. TACI, CD95, CD5, HLA-DR and TLR9 expression on B-cells significantly increased after treatment with either TNF-inhibitors and/ or tocilizumab, but no significant changes were observed in BAFF-R, BCMA, CD69, CD86, CXCR5, CD23, CD38 and IgM expression on B-cells when comparing baseline with post-treatment follow-ups. Alterations in B-cell gene expression of BAFF-R, TACI, TLR9, FcγRIIB, BCL-2, BLIMP-1 and β2M were found in ERA and established RA patients, but no significant differences were observed after TNF-inhibitors and tocilizumab treatment when comparing baseline and follow-ups. Serum levels of CXCL13, sCD23 and BAFF were not significantly affected by treatment with TNF-inhibitors and tocilizumab.In RA patients, the use of TNF-inhibitors and/ or tocilizumab treatment affects B-cell phenotype and IgD-CD27- memory B

  10. Early B-cell factor 1 regulates the expansion of B-cell progenitors in a dose-dependent manner.

    Science.gov (United States)

    Åhsberg, Josefine; Ungerbäck, Jonas; Strid, Tobias; Welinder, Eva; Stjernberg, Jenny; Larsson, Malin; Qian, Hong; Sigvardsson, Mikael

    2013-11-15

    Transcription factor doses are of importance for normal and malignant B-lymphocyte development; however, the understanding of underlying mechanisms and functional consequences of reduced transcription factor levels is limited. We have analyzed progenitor and B-lineage compartments in mice carrying heterozygote mutations in the E2a, Ebf1, or Pax5 gene. Although lymphoid progenitors from Ebf1 or Pax5 heterozygote mice were specified and lineage-restricted in a manner comparable with Wt progenitors, this process was severely impaired in E2a heterozygote mutant mice. This defect was not significantly enhanced upon combined deletion of E2a with Ebf1 or Pax5. Analysis of the pre-B-cell compartment in Ebf1 heterozygote mice revealed a reduction in cell numbers. These cells expressed Pax5 and other B-lineage-associated genes, and global gene expression analysis suggested that the reduction of the pre-B-cell compartment was a result of impaired pre-B-cell expansion. This idea was supported by a reduction in IL2Rα-expressing late pre-B-cells as well as by cell cycle analysis and by the finding that the complexity of the VDJ rearrangement patterns was comparable in Wt and Ebf1(+/-) pre-B-cells, although the number of progenitors was reduced. Heterozygote deletion of Ebf1 resulted in impaired response to IL7 in vitro and reduced expression levels of pre-BCR on the cell surface, providing possible explanations for the observed stage-specific reduction in cellular expansion. Thus, transcription factor doses are critical for specification as well as expansion of B-lymphoid progenitors, providing increased insight into the molecular regulation of B-cell development.

  11. Early B-cell Factor 1 Regulates the Expansion of B-cell Progenitors in a Dose-dependent Manner*

    Science.gov (United States)

    Åhsberg, Josefine; Ungerbäck, Jonas; Strid, Tobias; Welinder, Eva; Stjernberg, Jenny; Larsson, Malin; Qian, Hong; Sigvardsson, Mikael

    2013-01-01

    Transcription factor doses are of importance for normal and malignant B-lymphocyte development; however, the understanding of underlying mechanisms and functional consequences of reduced transcription factor levels is limited. We have analyzed progenitor and B-lineage compartments in mice carrying heterozygote mutations in the E2a, Ebf1, or Pax5 gene. Although lymphoid progenitors from Ebf1 or Pax5 heterozygote mice were specified and lineage-restricted in a manner comparable with Wt progenitors, this process was severely impaired in E2a heterozygote mutant mice. This defect was not significantly enhanced upon combined deletion of E2a with Ebf1 or Pax5. Analysis of the pre-B-cell compartment in Ebf1 heterozygote mice revealed a reduction in cell numbers. These cells expressed Pax5 and other B-lineage-associated genes, and global gene expression analysis suggested that the reduction of the pre-B-cell compartment was a result of impaired pre-B-cell expansion. This idea was supported by a reduction in IL2Rα-expressing late pre-B-cells as well as by cell cycle analysis and by the finding that the complexity of the VDJ rearrangement patterns was comparable in Wt and Ebf1+/− pre-B-cells, although the number of progenitors was reduced. Heterozygote deletion of Ebf1 resulted in impaired response to IL7 in vitro and reduced expression levels of pre-BCR on the cell surface, providing possible explanations for the observed stage-specific reduction in cellular expansion. Thus, transcription factor doses are critical for specification as well as expansion of B-lymphoid progenitors, providing increased insight into the molecular regulation of B-cell development. PMID:24078629

  12. Dataset of transcriptional landscape of B cell early activation

    Directory of Open Access Journals (Sweden)

    Alexander S. Garruss

    2015-09-01

    Full Text Available Signaling via B cell receptors (BCR and Toll-like receptors (TLRs result in activation of B cells with distinct physiological outcomes, but transcriptional regulatory mechanisms that drive activation and distinguish these pathways remain unknown. At early time points after BCR and TLR ligand exposure, 0.5 and 2 h, RNA-seq was performed allowing observations on rapid transcriptional changes. At 2 h, ChIP-seq was performed to allow observations on important regulatory mechanisms potentially driving transcriptional change. The dataset includes RNA-seq, ChIP-seq of control (Input, RNA Pol II, H3K4me3, H3K27me3, and a separate RNA-seq for miRNA expression, which can be found at Gene Expression Omnibus Dataset GSE61608. Here, we provide details on the experimental and analysis methods used to obtain and analyze this dataset and to examine the transcriptional landscape of B cell early activation.

  13. MDM2 gene SNP309 T/G and p53 gene SNP72 G/C do not influence diffuse large B-cell non-Hodgkin lymphoma onset or survival in central European Caucasians

    International Nuclear Information System (INIS)

    Bittenbring, Joerg; Pfreundschuh, Michael; Roemer, Klaus; Parisot, Frédérique; Wabo, Alain; Mueller, Monika; Kerschenmeyer, Lynn; Kreuz, Markus; Truemper, Lorenz; Landt, Olfert; Menzel, Alain

    2008-01-01

    SNP309 T/G (rs2279744) causes higher levels of MDM2, the most important negative regulator of the p53 tumor suppressor. SNP72 G/C (rs1042522) gives rise to a p53 protein with a greatly reduced capacity to induce apoptosis. Both polymorphisms have been implicated in cancer. The SNP309 G-allele has recently been reported to accelerate diffuse large B-cell lymphoma (DLBCL) formation in pre-menopausal women and suggested to constitute a genetic basis for estrogen affecting human tumorigenesis. Here we asked whether SNP309 and SNP72 are associated with DLBCL in women and are correlated with age of onset, diagnosis, or patient's survival. SNP309 and SNP72 were PCR-genotyped in a case-control study that included 512 controls and 311 patients diagnosed with aggressive NHL. Of these, 205 were diagnosed with DLBCL. The age of onset was similar in men and women. The control and patients group showed similar SNP309 and SNP72 genotype frequencies. Importantly and in contrast to the previous findings, similar genotype frequencies were observed in female patients diagnosed by 51 years of age and those diagnosed later. Specifically, 3/20 female DLBCL patients diagnosed by 51 years of age were homozygous for SNP309 G and 2/20 DLBCL females in that age group were homozygous for SNP72 C. Neither SNP309 nor SNP72 had a significant influence on event-free and overall survival in multivariate analyses. In contrast to the previous study on Ashkenazi Jewish Caucasians, DLBCL in pre-menopausal women of central European Caucasian ethnicity was not associated with SNP309 G. Neither SNP309 nor SNP72 seem to be correlated with age of onset, diagnosis, or survival of patients

  14. MDM2 gene SNP309 T/G and p53 gene SNP72 G/C do not influence diffuse large B-cell non-Hodgkin lymphoma onset or survival in central European Caucasians

    Directory of Open Access Journals (Sweden)

    Landt Olfert

    2008-04-01

    Full Text Available Abstract Background SNP309 T/G (rs2279744 causes higher levels of MDM2, the most important negative regulator of the p53 tumor suppressor. SNP72 G/C (rs1042522 gives rise to a p53 protein with a greatly reduced capacity to induce apoptosis. Both polymorphisms have been implicated in cancer. The SNP309 G-allele has recently been reported to accelerate diffuse large B-cell lymphoma (DLBCL formation in pre-menopausal women and suggested to constitute a genetic basis for estrogen affecting human tumorigenesis. Here we asked whether SNP309 and SNP72 are associated with DLBCL in women and are correlated with age of onset, diagnosis, or patient's survival. Methods SNP309 and SNP72 were PCR-genotyped in a case-control study that included 512 controls and 311 patients diagnosed with aggressive NHL. Of these, 205 were diagnosed with DLBCL. Results The age of onset was similar in men and women. The control and patients group showed similar SNP309 and SNP72 genotype frequencies. Importantly and in contrast to the previous findings, similar genotype frequencies were observed in female patients diagnosed by 51 years of age and those diagnosed later. Specifically, 3/20 female DLBCL patients diagnosed by 51 years of age were homozygous for SNP309 G and 2/20 DLBCL females in that age group were homozygous for SNP72 C. Neither SNP309 nor SNP72 had a significant influence on event-free and overall survival in multivariate analyses. Conclusion In contrast to the previous study on Ashkenazi Jewish Caucasians, DLBCL in pre-menopausal women of central European Caucasian ethnicity was not associated with SNP309 G. Neither SNP309 nor SNP72 seem to be correlated with age of onset, diagnosis, or survival of patients.

  15. B-Cell Hematologic Malignancy Vaccination Registry

    Science.gov (United States)

    2017-12-29

    Monoclonal Gammopathy of Undetermined Significance; Multiple Myeloma; Waldenstrom Macroglobulinemia; Lymphocytosis; Lymphoma, Non-Hodgkin; B-Cell Chronic Lymphocytic Leukemia; Hematological Malignancies

  16. Dual-reactive B cells are autoreactive and highly enriched in the plasmablast and memory B cell subsets of autoimmune mice

    Science.gov (United States)

    Fournier, Emilie M.; Velez, Maria-Gabriela; Leahy, Katelyn; Swanson, Cristina L.; Rubtsov, Anatoly V.; Torres, Raul M.

    2012-01-01

    Rare dual-reactive B cells expressing two types of Ig light or heavy chains have been shown to participate in immune responses and differentiate into IgG+ cells in healthy mice. These cells are generated more often in autoreactive mice, leading us to hypothesize they might be relevant in autoimmunity. Using mice bearing Igk allotypic markers and a wild-type Ig repertoire, we demonstrate that the generation of dual-κ B cells increases with age and disease progression in autoimmune-prone MRL and MRL/lpr mice. These dual-reactive cells express markers of activation and are more frequently autoreactive than single-reactive B cells. Moreover, dual-κ B cells represent up to half of plasmablasts and memory B cells in autoimmune mice, whereas they remain infrequent in healthy mice. Differentiation of dual-κ B cells into plasmablasts is driven by MRL genes, whereas the maintenance of IgG+ cells is partly dependent on Fas inactivation. Furthermore, dual-κ B cells that differentiate into plasmablasts retain the capacity to secrete autoantibodies. Overall, our study indicates that dual-reactive B cells significantly contribute to the plasmablast and memory B cell populations of autoimmune-prone mice suggesting a role in autoimmunity. PMID:22927551

  17. Grb2 and GRAP connect the B cell antigen receptor to Erk MAP kinase activation in human B cells.

    Science.gov (United States)

    Vanshylla, Kanika; Bartsch, Caren; Hitzing, Christoffer; Krümpelmann, Laura; Wienands, Jürgen; Engels, Niklas

    2018-03-09

    The B cell antigen receptor (BCR) employs enzymatically inactive adaptor proteins to facilitate activation of intracellular signaling pathways. In animal model systems, adaptor proteins of the growth factor receptor-bound 2 (Grb2) family have been shown to serve critical functions in lymphocytes. However, the roles of Grb2 and the Grb2-related adaptor protein (GRAP) in human B lymphocytes remain unclear. Using TALEN-mediated gene targeting, we show that in human B cells Grb2 and GRAP amplify signaling by the immunoglobulin tail tyrosine (ITT) motif of mIgE-containing BCRs and furthermore connect immunoreceptor tyrosine-based activation motif (ITAM) signaling to activation of the Ras-controlled Erk MAP kinase pathway. In contrast to mouse B cells, BCR-induced activation of Erk in human B cells is largely independent of phospholipase C-ɣ activity and diacylglycerol-responsive members of Ras guanine nucleotide releasing proteins. Together, our results demonstrate that Grb2 family adaptors are critical regulators of ITAM and ITT signaling in naïve and IgE-switched human B cells.

  18. Impairment of Mature B Cell Maintenance upon Combined Deletion of the Alternative NF-κB Transcription Factors RELB and NF-κB2 in B Cells.

    Science.gov (United States)

    De Silva, Nilushi S; Silva, Kathryn; Anderson, Michael M; Bhagat, Govind; Klein, Ulf

    2016-03-15

    BAFF is critical for the survival and maturation of mature B cells. BAFF, via BAFFR, activates multiple signaling pathways in B cells, including the alternative NF-κB pathway. The transcription factors RELB and NF-κB2 (p100/p52) are the downstream mediators of the alternative pathway; however, the B cell-intrinsic functions of these NF-κB subunits have not been studied in vivo using conditional alleles, either individually or in combination. We in this study report that B cell-specific deletion of relb led to only a slight decrease in the fraction of mature splenic B cells, whereas deletion of nfkb2 caused a marked reduction. This phenotype was further exacerbated upon combined deletion of relb and nfkb2 and most dramatically affected the maintenance of marginal zone B cells. BAFF stimulation, in contrast to CD40 activation, was unable to rescue relb/nfkb2-deleted B cells in vitro. RNA-sequencing analysis of BAFF-stimulated nfkb2-deleted versus normal B cells suggests that the alternative NF-κB pathway, in addition to its critical role in BAFF-mediated cell survival, may control the expression of genes involved in the positioning of B cells within the lymphoid microenvironment and in the establishment of T cell-B cell interactions. Thus, by ablating the downstream transcription factors of the alternative NF-κB pathway specifically in B cells, we identify in this study a critical role for the combined activity of the RELB and NF-κB2 subunits in B cell homeostasis that cannot be compensated for by the canonical NF-κB pathway under physiological conditions. Copyright © 2016 by The American Association of Immunologists, Inc.

  19. A Novel VHH Antibody Targeting the B Cell-Activating Factor for B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Wen Wu

    2014-05-01

    Full Text Available Objective: To construct an immune alpaca phage display library, in order to obtain a single domain anti-BAFF (B cell-activating factor antibody. Methods: Using phage display technology, we constructed an immune alpaca phage display library, selected anti-BAFF single domain antibodies (sdAbs, cloned three anti-BAFF single-domain antibody genes into expression vector pSJF2, and expressed them efficiently in Escherichia coli. The affinity of different anti-BAFF sdAbs were measured by Bio layer interferometry. The in vitro biological function of three sdAbs was investigated by cell counting kit-8 (CCK-8 assay and a competitive enzyme-linked immunosorbent assay (ELISA. Results: We obtained three anti-BAFF single domain antibodies (anti-BAFF64, anti-BAFF52 and anti-BAFFG3, which were produced in high yield in Escherichia coli and inhibited tumor cell proliferation in vitro. Conclusion: The selected anti-BAFF antibodies could be candidates for B-cell lymphoma therapies.

  20. B Lymphocyte Lineage Specification, Commitment and Epigenetic Control of Transcription by Early B Cell Factor 1

    OpenAIRE

    Hagman, James; Ramírez, Julita; Lukin, Kara

    2012-01-01

    Early B cell factor 1 (EBF1) is a transcription factor that is critical for both B lymphopoiesis and B cell function. EBF1 is a requisite component of the B lymphocyte transcriptional network and is essential for B lineage specification. Recent studies revealed roles for EBF1 in B cell commitment. EBF1 binds its target genes via a DNA-binding domain including a unique ‘zinc knuckle’, which mediates a novel mode of DNA recognition. Chromatin immunoprecipitation of EBF1 in pro-B cells defined h...

  1. Positive intergenic feedback circuitry, involving EBF1 and FOXO1, orchestrates B-cell fate

    OpenAIRE

    Mansson, Robert; Welinder, Eva; Åhsberg, Josefine; Lin, Yin C.; Benner, Christopher; Glass, Christopher K.; Lucas, Joseph S.; Sigvardsson, Mikael; Murre, Cornelis

    2012-01-01

    Recent studies have identified a number of transcriptional regulators, including E2A, early B-cell factor 1 (EBF1), FOXO1, and paired box gene 5 (PAX5), that promote early B-cell development. However, how this ensemble of regulators mechanistically promotes B-cell fate remains poorly understood. Here we demonstrate that B-cell development in FOXO1-deficient mice is arrested in the common lymphoid progenitor (CLP) LY6D+ cell stage. We demonstrate that this phenotype closely resembles the arres...

  2. Genetics and Pathogenesis of Diffuse Large B-Cell Lymphoma.

    Science.gov (United States)

    Schmitz, Roland; Wright, George W; Huang, Da Wei; Johnson, Calvin A; Phelan, James D; Wang, James Q; Roulland, Sandrine; Kasbekar, Monica; Young, Ryan M; Shaffer, Arthur L; Hodson, Daniel J; Xiao, Wenming; Yu, Xin; Yang, Yandan; Zhao, Hong; Xu, Weihong; Liu, Xuelu; Zhou, Bin; Du, Wei; Chan, Wing C; Jaffe, Elaine S; Gascoyne, Randy D; Connors, Joseph M; Campo, Elias; Lopez-Guillermo, Armando; Rosenwald, Andreas; Ott, German; Delabie, Jan; Rimsza, Lisa M; Tay Kuang Wei, Kevin; Zelenetz, Andrew D; Leonard, John P; Bartlett, Nancy L; Tran, Bao; Shetty, Jyoti; Zhao, Yongmei; Soppet, Dan R; Pittaluga, Stefania; Wilson, Wyndham H; Staudt, Louis M

    2018-04-12

    Diffuse large B-cell lymphomas (DLBCLs) are phenotypically and genetically heterogeneous. Gene-expression profiling has identified subgroups of DLBCL (activated B-cell-like [ABC], germinal-center B-cell-like [GCB], and unclassified) according to cell of origin that are associated with a differential response to chemotherapy and targeted agents. We sought to extend these findings by identifying genetic subtypes of DLBCL based on shared genomic abnormalities and to uncover therapeutic vulnerabilities based on tumor genetics. We studied 574 DLBCL biopsy samples using exome and transcriptome sequencing, array-based DNA copy-number analysis, and targeted amplicon resequencing of 372 genes to identify genes with recurrent aberrations. We developed and implemented an algorithm to discover genetic subtypes based on the co-occurrence of genetic alterations. We identified four prominent genetic subtypes in DLBCL, termed MCD (based on the co-occurrence of MYD88 L265P and CD79B mutations), BN2 (based on BCL6 fusions and NOTCH2 mutations), N1 (based on NOTCH1 mutations), and EZB (based on EZH2 mutations and BCL2 translocations). Genetic aberrations in multiple genes distinguished each genetic subtype from other DLBCLs. These subtypes differed phenotypically, as judged by differences in gene-expression signatures and responses to immunochemotherapy, with favorable survival in the BN2 and EZB subtypes and inferior outcomes in the MCD and N1 subtypes. Analysis of genetic pathways suggested that MCD and BN2 DLBCLs rely on "chronic active" B-cell receptor signaling that is amenable to therapeutic inhibition. We uncovered genetic subtypes of DLBCL with distinct genotypic, epigenetic, and clinical characteristics, providing a potential nosology for precision-medicine strategies in DLBCL. (Funded by the Intramural Research Program of the National Institutes of Health and others.).

  3. Transcription factor Ebf1 regulates differentiation stage-specific signaling, proliferation, and survival of B cells.

    Science.gov (United States)

    Györy, Ildiko; Boller, Sören; Nechanitzky, Robert; Mandel, Elizabeth; Pott, Sebastian; Liu, Edison; Grosschedl, Rudolf

    2012-04-01

    The transcription factor Ebf1 is an important determinant of early B lymphopoiesis. To gain insight into the functions of Ebf1 at distinct stages of differentiation, we conditionally inactivated Ebf1. We found that Ebf1 is required for the proliferation, survival, and signaling of pro-B cells and peripheral B-cell subsets, including B1 cells and marginal zone B cells. The proliferation defect of Ebf1-deficient pro-B cells and the impaired expression of multiple cell cycle regulators are overcome by transformation with v-Abl. The survival defect of transformed Ebf1(fl/fl) pro-B cells can be rescued by the forced expression of the Ebf1 targets c-Myb or Bcl-x(L). In mature B cells, Ebf1 deficiency interferes with signaling via the B-cell-activating factor receptor (BAFF-R)- and B-cell receptor (BCR)-dependent Akt pathways. Moreover, Ebf1 is required for germinal center formation and class switch recombination. Genome-wide analyses of Ebf1-mediated gene expression and chromatin binding indicate that Ebf1 regulates both common and distinct sets of genes in early and late stage B cells. By regulating important components of transcription factor and signaling networks, Ebf1 appears to be involved in the coordination of cell proliferation, survival, and differentiation at multiple stages of B lymphopoiesis.

  4. B Cell Tolerance in Health and Disease

    Directory of Open Access Journals (Sweden)

    Murali Gururajan

    2014-02-01

    Full Text Available B lymphocyte receptors are generated randomly during the bone marrow developmental phase of B cells. Hence, the B cell repertoire consists of both self and foreign antigen specificities necessitating specific tolerance mechanisms to eliminate self-reactive B cells. This review summarizes the major mechanisms of B cell tolerance, which include clonal deletion, anergy and receptor editing. In the bone marrow presentation of antigen in membrane bound form is more effective than soluble form and the role of dendritic cells in this process is discussed. Toll like receptor derived signals affect activation of B cells by certain ligands such as nucleic acids and have been shown to play crucial roles in the development of autoimmunity in several animal models. In the periphery availability of BAFF, a B cell survival factor plays a critical role in the survival of self-reactive B cells. Antibodies against BAFF have been found to be effective therapeutic agents in lupus like autoimmune diseases. Recent developments are targeting anergy to control the growth of chronic lymphocytic leukemia cells.

  5. EBI2 overexpression in mice leads to B1 B-cell expansion and chronic lymphocytic leukemia-like B-cell malignancies.

    Science.gov (United States)

    Niss Arfelt, Kristine; Barington, Line; Benned-Jensen, Tau; Kubale, Valentina; Kovalchuk, Alexander L; Daugvilaite, Viktorija; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup; Egerod, Kristoffer L; Bassi, Maria R; Spiess, Katja; Schwartz, Thue W; Wang, Hongsheng; Morse, Herbert C; Holst, Peter J; Rosenkilde, Mette M

    2017-02-16

    Human and mouse chronic lymphocytic leukemia (CLL) develops from CD5 + B cells that in mice and macaques are known to define the distinct B1a B-cell lineage. B1a cells are characterized by lack of germinal center (GC) development, and the B1a cell population is increased in mice with reduced GC formation. As a major mediator of follicular B-cell migration, the G protein-coupled receptor Epstein-Barr virus-induced gene 2 ( EBI2 or GPR183 ) directs B-cell migration in the lymphoid follicles in response to its endogenous ligands, oxysterols. Thus, upregulation of EBI2 drives the B cells toward the extrafollicular area, whereas downregulation is essential for GC formation. We therefore speculated whether increased expression of EBI2 would lead to an expanded B1 cell subset and, ultimately, progression to CLL. Here, we demonstrate that B-cell-targeted expression of human EBI2 (hEBI2) in mice reduces GC-dependent immune responses, reduces total immunoglobulin M (IgM) and IgG levels, and leads to increased proliferation and upregulation of cellular oncogenes. Furthermore, hEBI2 overexpression leads to an abnormally expanded CD5 + B1a B-cell subset (present as early as 4 days after birth), late-onset lymphoid cancer development, and premature death. These findings are highly similar to those observed in CLL patients and identify EBI2 as a promoter of B-cell malignancies.

  6. Ikaros limits follicular B cell activation by regulating B cell receptor signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Heizmann, Beate [Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch (France); Sellars, MacLean [Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch (France); David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Macias-Garcia, Alejandra [Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch (France); Institute for Medical Engineering and Science at MIT, Cambridge, MA 02139 (United States); Chan, Susan, E-mail: scpk@igbmc.fr [Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch (France); Kastner, Philippe, E-mail: scpk@igbmc.fr [Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch (France); Faculté de Médecine, Université de Strasbourg, Strasbourg (France)

    2016-02-12

    The Ikaros transcription factor is essential for early B cell development, but its effect on mature B cells is debated. We show that Ikaros is required to limit the response of naive splenic B cells to B cell receptor signals. Ikaros deficient follicular B cells grow larger and enter cell cycle faster after anti-IgM stimulation. Unstimulated mutant B cells show deregulation of positive and negative regulators of signal transduction at the mRNA level, and constitutive phosphorylation of ERK, p38, SYK, BTK, AKT and LYN. Stimulation results in enhanced and prolonged ERK and p38 phosphorylation, followed by hyper-proliferation. Pharmacological inhibition of ERK and p38 abrogates the increased proliferative response of Ikaros deficient cells. These results suggest that Ikaros functions as a negative regulator of follicular B cell activation.

  7. Ikaros limits follicular B cell activation by regulating B cell receptor signaling pathways

    International Nuclear Information System (INIS)

    Heizmann, Beate; Sellars, MacLean; Macias-Garcia, Alejandra; Chan, Susan; Kastner, Philippe

    2016-01-01

    The Ikaros transcription factor is essential for early B cell development, but its effect on mature B cells is debated. We show that Ikaros is required to limit the response of naive splenic B cells to B cell receptor signals. Ikaros deficient follicular B cells grow larger and enter cell cycle faster after anti-IgM stimulation. Unstimulated mutant B cells show deregulation of positive and negative regulators of signal transduction at the mRNA level, and constitutive phosphorylation of ERK, p38, SYK, BTK, AKT and LYN. Stimulation results in enhanced and prolonged ERK and p38 phosphorylation, followed by hyper-proliferation. Pharmacological inhibition of ERK and p38 abrogates the increased proliferative response of Ikaros deficient cells. These results suggest that Ikaros functions as a negative regulator of follicular B cell activation.

  8. Memory in the B-cell compartment: antibody affinity maturation.

    OpenAIRE

    Neuberger, M S; Ehrenstein, M R; Rada, C; Sale, J; Batista, F D; Williams, G; Milstein, C

    2000-01-01

    In the humoral arm of the immune system, the memory response is not only more quickly elicited and of greater magnitude than the primary response, but it is also different in quality. In the recall response to antigen, the antibodies produced are of higher affinity and of different isotype (typically immunoglobulin G rather than immunoglobulin M). This maturation rests on the antigen dependence of B-cell maturation and is effected by programmed genetic modifications of the immunoglobulin gene...

  9. Lipid rafts and B cell signaling.

    Science.gov (United States)

    Gupta, Neetu; DeFranco, Anthony L

    2007-10-01

    B cells comprise an essential component of the humoral immune system. They are equipped with the unique ability to synthesize and secrete pathogen-neutralizing antibodies, and share with professional antigen presenting cells the ability to internalize foreign antigens, and process them for presentation to helper T cells. Recent evidence indicates that specialized cholesterol- and glycosphingolipid-rich microdomains in the plasma membrane commonly referred to as lipid rafts, serve to compartmentalize key signaling molecules during the different stages of B cell activation including B cell antigen receptor (BCR)-initiated signal transduction, endocytosis of BCR-antigen complexes, loading of antigenic peptides onto MHC class II molecules, MHC-II associated antigen presentation to helper T cells, and receipt of helper signals via the CD40 receptor. Here we review the recent literature arguing for a role of lipid rafts in the spatial organization of B cell function.

  10. B-cell waste classification sampling plan

    Energy Technology Data Exchange (ETDEWEB)

    HOBART, R.L.

    1999-11-20

    This report documents the methods used to collect samples and analyze data necessary to verify and/or determine the radionuclide content of the 324 Facility B-Cell decontamination and decommissioning waste stream.

  11. The early history of B cells.

    Science.gov (United States)

    Cooper, Max D

    2015-03-01

    The separate development of functionally intertwined lineages of lymphocytes known as B cells and T cells is now recognized as a fundamental organizing principle of the adaptive immune system in all vertebrates. Immunologists strive to define the different sublineages of the clonally diverse B cells and T cells, how they interact with each other and how they interact with innate lymphoid cells and other elements of the innate immune system to counter infections, cancer and the development of autoimmune and inflammatory diseases. On the 50th anniversary of the recognition of B cells as a discrete cell lineage, this Timeline article recounts some of the milestones marking the development of the concept that B cells are a functionally and developmentally distinct arm of the adaptive immune system.

  12. Transcriptional profiling of PBMCs unravels B cell mediated immunopathogenic imprints of HCV vasculitis.

    Science.gov (United States)

    Comstock, Emily; Kim, Cheol-Woo; Murphy, Alison; Emmanuel, Benjamin; Zhang, Xi; Sneller, Michael; Poonia, Bhawna; Kottilil, Shyamasundaran

    2017-01-01

    B cell depletion therapy using rituximab has been shown to be effective in achieving remission in patients with HCV-mixed cryoglobulinemic (MC) vasculitis. Previously, we have demonstrated abnormalities in peripheral immune cells involving neutrophils, chemotaxis, and innate immune activation among patients with HCV-MC vasculitis when compared to HCV patients without vasculitis. In this study, we evaluated the effect of B cell depletion therapy on transcriptional profiles of peripheral blood mononuclear cells before and after riruximab therapy, in order to unravel the pathogenic mechanism involved in HCV-MC vasculitis induced by abnormal B cell proliferation. DNA microarray analysis was performed using RNA from PBMCs from seven patients with HCV-MC vasculitis and seven normal volunteers. DNA was hybridized to Affymetrix U133A chips. After normalization, differentially expressed gene list with treatment was generated using partitional clustering. RT-PCR, flow cytometry, and enzyme immunoassay (EIA) was used to validate DNA microarray findings. Differentially expressed genes included B cells and non-B cell genes. Validation of genes using purified cell subsets demonstrated distinct effect of B cell depletion therapy on non-B cells, such as monocytes, T cells, and NK cells. Notably, B lymphocyte stimulator (BLyS) levels were persistently elevated in patients who subsequently relapsed. In conclusion, pathogenesis of HCV-MC vasculitis is mediated by abnormal proliferation of B cells, driven by BLyS, leading to significant effects on non-B cells in mediating symptomatology. Future therapeutics using a combination approach of B cell depletion and proliferation may be desired to achieve long-term remission.

  13. The progeny of a single virgin B cell predominates the human recall B cell response to the capsular polysaccharide of Haemophilus influenzae type b

    DEFF Research Database (Denmark)

    Barington, T; Hougs, L; Juul, L

    1996-01-01

    of Haemophilus influenzae type b coupled to tetanus toxoid. We combined affinity purification of circulating vaccine-induced Ab-secreting cells with PCR amplification of cDNA followed by cloning and sequencing. Forty-eight and 42 kappa VJ gene transcripts were analyzed from two adults, respectively. Both......Restricted V region diversity is a key feature of Abs to many haptens and simple polysaccharides. Two possible mechanisms exist: 1) selection of many clonally unrelated B cells using very similar or identical VDJ and VJ rearrangements; and 2) selection of a heavily expanded progeny of few virgin B...... cells. How many virgin B cells eventually give rise to the total Ab response to a simple Ag is a fundamental immunologic question. In this report, we address this question in human adults by analyzing the rearranged VkappaJkappa genes of B cells responding to a single dose of the capsular polysaccharide...

  14. The transcription factor Gli3 promotes B cell development in fetal liver through repression of Shh.

    Science.gov (United States)

    Solanki, Anisha; Lau, Ching-In; Saldaña, José Ignacio; Ross, Susan; Crompton, Tessa

    2017-07-03

    Before birth, B cells develop in the fetal liver (FL). In this study, we show that Gli3 activity in the FL stroma is required for B cell development. In the Gli3-deficient FL, B cell development was reduced at multiple stages, whereas the Sonic hedgehog (Hh [Shh])-deficient FL showed increased B cell development, and Gli3 functioned to repress Shh transcription. Use of a transgenic Hh-reporter mouse showed that Shh signals directly to developing B cells and that Hh pathway activation was increased in developing B cells from Gli3-deficient FLs. RNA sequencing confirmed that Hh-mediated transcription is increased in B-lineage cells from Gli3-deficient FL and showed that these cells expressed reduced levels of B-lineage transcription factors and B cell receptor (BCR)/pre-BCR-signaling genes. Expression of the master regulators of B cell development Ebf1 and Pax5 was reduced in developing B cells from Gli3-deficient FL but increased in Shh-deficient FL, and in vitro Shh treatment or neutralization reduced or increased their expression, respectively. © 2017 Solanki et al.

  15. B Cells Producing Type I IFN Modulate Macrophage Polarization in Tuberculosis.

    Science.gov (United States)

    Bénard, Alan; Sakwa, Imme; Schierloh, Pablo; Colom, André; Mercier, Ingrid; Tailleux, Ludovic; Jouneau, Luc; Boudinot, Pierre; Al-Saati, Talal; Lang, Roland; Rehwinkel, Jan; Loxton, Andre G; Kaufmann, Stefan H E; Anton-Leberre, Véronique; O'Garra, Anne; Sasiain, Maria Del Carmen; Gicquel, Brigitte; Fillatreau, Simon; Neyrolles, Olivier; Hudrisier, Denis

    2018-03-15

    In addition to their well-known function as antibody-producing cells, B lymphocytes can markedly influence the course of infectious or noninfectious diseases via antibody-independent mechanisms. In tuberculosis (TB), B cells accumulate in lungs, yet their functional contribution to the host response remains poorly understood. To document the role of B cells in TB in an unbiased manner. We generated the transcriptome of B cells isolated from Mycobacterium tuberculosis (Mtb)-infected mice and validated the identified key pathways using in vitro and in vivo assays. The obtained data were substantiated using B cells from pleural effusion of patients with TB. B cells isolated from Mtb-infected mice displayed a STAT1 (signal transducer and activator of transcription 1)-centered signature, suggesting a role for IFNs in B-cell response to infection. B cells stimulated in vitro with Mtb produced type I IFN, via a mechanism involving the innate sensor STING (stimulator of interferon genes), and antagonized by MyD88 (myeloid differentiation primary response 88) signaling. In vivo, B cells expressed type I IFN in the lungs of Mtb-infected mice and, of clinical relevance, in pleural fluid from patients with TB. Type I IFN expression by B cells induced an altered polarization of macrophages toward a regulatory/antiinflammatory profile in vitro. In vivo, increased provision of type I IFN by B cells in a murine model of B cell-restricted Myd88 deficiency correlated with an enhanced accumulation of regulatory/antiinflammatory macrophages in Mtb-infected lungs. Type I IFN produced by Mtb-stimulated B cells favors macrophage polarization toward a regulatory/antiinflammatory phenotype during Mtb infection.

  16. PDK1 regulates VDJ recombination, cell-cycle exit and survival during B-cell development.

    Science.gov (United States)

    Venigalla, Ram K C; McGuire, Victoria A; Clarke, Rosemary; Patterson-Kane, Janet C; Najafov, Ayaz; Toth, Rachel; McCarthy, Pierre C; Simeons, Frederick; Stojanovski, Laste; Arthur, J Simon C

    2013-04-03

    Phosphoinositide-dependent kinase-1 (PDK1) controls the activation of a subset of AGC kinases. Using a conditional knockout of PDK1 in haematopoietic cells, we demonstrate that PDK1 is essential for B cell development. B-cell progenitors lacking PDK1 arrested at the transition of pro-B to pre-B cells, due to a cell autonomous defect. Loss of PDK1 decreased the expression of the IgH chain in pro-B cells due to impaired recombination of the IgH distal variable segments, a process coordinated by the transcription factor Pax5. The expression of Pax5 in pre-B cells was decreased in PDK1 knockouts, which correlated with reduced expression of the Pax5 target genes IRF4, IRF8 and Aiolos. As a result, Ccnd3 is upregulated in PDK1 knockout pre-B cells and they have an impaired ability to undergo cell-cycle arrest, a necessary event for Ig light chain rearrangement. Instead, these cells underwent apoptosis that correlated with diminished expression of the pro-survival gene Bcl2A1. Reintroduction of both Pax5 and Bcl2A1 together into PDK1 knockout pro-B cells restored their ability to differentiate in vitro into mature B cells.

  17. Ikaros is absolutely required for pre-B cell differentiation by attenuating IL-7 signals.

    Science.gov (United States)

    Heizmann, Beate; Kastner, Philippe; Chan, Susan

    2013-12-16

    Pre-B cell receptor (pre-BCR) signaling and migration from IL-7-rich environments cooperate to drive pre-B cell differentiation via transcriptional programs that remain unclear. We show that the Ikaros transcription factor is required for the differentiation of large pre-B to small pre-B cells. Mice deleted for Ikaros in pro/pre-B cells show a complete block of differentiation at the fraction C' stage, and Ikaros-null pre-B cells cannot differentiate upon withdrawal of IL-7 in vitro. Restoration of Ikaros function rescues pre-B cell differentiation in vitro and in vivo and depends on DNA binding. Ikaros is required for the down-regulation of the pre-BCR, Igκ germline transcription, and Ig L chain recombination. Furthermore, Ikaros antagonizes the IL-7-dependent regulation of >3,000 genes, many of which are up- or down-regulated between fractions C' and D. Affected genes include those important for survival, metabolism, B cell signaling, and function, as well as transcriptional regulators like Ebf1, Pax5, and the Foxo1 family. Our data thus identify Ikaros as a central regulator of IL-7 signaling and pre-B cell development.

  18. Abundance of a restricted fetal B cell repertoire in marrow transplant recipients.

    Science.gov (United States)

    Storek, J; King, L; Ferrara, S; Marcelo, D; Saxon, A; Braun, J

    1994-11-01

    Patients undergoing bone marrow transplantation are humorally immunodeficient for one or more years post-transplant. This immunodeficiency could be partially caused by B cell repertoire restriction similar to that observed in ontogeny. To test this idea, the abundance of rearranged genomic segments bearing five variable heavy chain (VH) genes was compared in patients at several timepoints post-transplant and in immunologically normal neonates, infants and adults. The genes evaluated in the study (VH6, VH4-58p2, VH3-56p1, VH3-20p1 and VH3-13-2) were selected from those commonly utilized by fetal B cells. The assay employed quantitative PCR and oligonucleotide hybridization detection under conditions designed to detect relatively unmutated forms of these genes. In blood B cells from early post-transplant (2-5 months) patients, these VH genes were markedly overutilized compared with normal adults. B cells from late post-transplant (6-21 months) patients and from normal neonates and infants also overutilized these genes; however, to a lesser degree than early post-transplant B cells. The data suggest that, as in ontogeny, the B cell repertoire is strikingly restricted to fetal-type VH genes early post-transplant, and may become normal only very late (years) post-transplant.

  19. Gammaherpesvirus Colonization of the Spleen Requires Lytic Replication in B Cells.

    Science.gov (United States)

    Lawler, Clara; de Miranda, Marta Pires; May, Janet; Wyer, Orry; Simas, J Pedro; Stevenson, Philip G

    2018-04-01

    Gammaherpesviruses infect lymphocytes and cause lymphocytic cancers. Murid herpesvirus-4 (MuHV-4), Epstein-Barr virus, and Kaposi's sarcoma-associated herpesvirus all infect B cells. Latent infection can spread by B cell recirculation and proliferation, but whether this alone achieves systemic infection is unclear. To test the need of MuHV-4 for lytic infection in B cells, we flanked its essential ORF50 lytic transactivator with loxP sites and then infected mice expressing B cell-specific Cre (CD19-Cre). The floxed virus replicated normally in Cre - mice. In CD19-Cre mice, nasal and lymph node infections were maintained; but there was little splenomegaly, and splenic virus loads remained low. Cre-mediated removal of other essential lytic genes gave a similar phenotype. CD19-Cre spleen infection by intraperitoneal virus was also impaired. Therefore, MuHV-4 had to emerge lytically from B cells to colonize the spleen. An important role for B cell lytic infection in host colonization is consistent with the large CD8 + T cell responses made to gammaherpesvirus lytic antigens during infectious mononucleosis and suggests that vaccine-induced immunity capable of suppressing B cell lytic infection might reduce long-term virus loads. IMPORTANCE Gammaherpesviruses cause B cell cancers. Most models of host colonization derive from cell cultures with continuous, virus-driven B cell proliferation. However, vaccines based on these models have worked poorly. To test whether proliferating B cells suffice for host colonization, we inactivated the capacity of MuHV-4, a gammaherpesvirus of mice, to reemerge from B cells. The modified virus was able to colonize a first wave of B cells in lymph nodes but spread poorly to B cells in secondary sites such as the spleen. Consequently, viral loads remained low. These results were consistent with virus-driven B cell proliferation exploiting normal host pathways and thus having to transfer lytically to new B cells for new proliferation. We

  20. The PI3K isoforms p110alpha and p110delta are essential for pre-B cell receptor signaling and B cell development.

    Science.gov (United States)

    Ramadani, Faruk; Bolland, Daniel J; Garcon, Fabien; Emery, Juliet L; Vanhaesebroeck, Bart; Corcoran, Anne E; Okkenhaug, Klaus

    2010-08-10

    B cell development is controlled by a series of checkpoints that ensure that the immunoglobulin (Ig)-encoding genes produce a functional B cell receptor (BCR) and antibodies. As part of this process, recombination-activating gene (Rag) proteins regulate the in-frame assembly of the Ig-encoding genes. The BCR consists of Ig proteins in complex with the immunoreceptor tyrosine-based activation motif (ITAM)-containing Igalpha and Igbeta chains. Whereas the activation of the tyrosine kinases Src and Syk is essential for BCR signaling, the pathways that act downstream of these kinases are incompletely defined. Previous work has revealed a key role for the p110delta isoform of phosphatidylinositol 3-kinase (PI3K) in agonist-induced BCR signaling; however, early B cell development and mature B cell survival, which depend on agonist-independent or "tonic" BCR signaling, are not substantially affected by a deficiency in p110delta. Here, we show that p110alpha, but not p110beta, compensated in the absence of p110delta to promote early B cell development in the bone marrow and B cell survival in the spleen. In the absence of both p110alpha and p110delta activities, pre-BCR signaling failed to suppress the production of Rag proteins and to promote developmental progression of B cell progenitors. Unlike p110delta, however, p110alpha did not contribute to agonist-induced BCR signaling. These studies indicate that either p110alpha or p110delta can mediate tonic signaling from the BCR, but only p110delta can contribute to antigen-dependent activation of B cells.

  1. PU.1 cooperates with IRF4 and IRF8 to suppress pre-B cell leukemia

    Science.gov (United States)

    Pang, Swee Heng Milon; Minnich, Martina; Gangatirkar, Pradnya; Zheng, Zhiqiang; Ebert, Anja; Song, Guangchun; Dickins, Ross A; Corcoran, Lynn M; Mullighan, Charles G.; Busslinger, Meinrad; Huntington, Nicholas D; Nutt, Stephen L; Carotta, Sebastian

    2016-01-01

    The Ets family transcription factor PU.1 and the interferon regulatory factor (IRF)4 and IRF8 regulate gene expression by binding to composite DNA sequences known as Ets/interferon consensus elements (EICE). Although all three factors are expressed from the onset of B cell development, single deficiency of these factors in B cell progenitors only mildly impacts on bone marrow B-lymphopoiesis. Here we tested whether PU.1 cooperates with IRF factors in regulating early B cell development. Lack of PU.1 and IRF4 resulted in a partial block in development the pre-B cell stage. The combined deletion of PU.1 and IRF8 reduced recirculating B cell numbers. Strikingly, all PU.1/IRF4 and approximately 50% of PU.1/IRF8 double deficient mice developed pre-B cell acute lymphoblastic leukemia (B-ALL) associated with reduced expression of the established B-lineage tumor suppressor genes, Ikaros and Spi-B. These genes are directly regulated by PU.1/IRF4/IRF8, and restoration of Ikaros or Spi-B expression inhibited leukemic cell growth. In summary, we demonstrate that PU.1, IRF4 and IRF8 cooperate to regulate early B cell development and to prevent pre-B-ALL formation. PMID:26932576

  2. B cell phenotypes in patients with rheumatoid arthritis relapsing after rituximab: expression of B cell-activating factor-binding receptors on B cell subsets.

    Science.gov (United States)

    Becerra, E; De La Torre, I; Leandro, M J; Cambridge, G

    2017-12-01

    Serum levels of B cell-activating factor (BAFF) rise following rituximab (RTX) therapy in patients with rheumatoid arthritis (RA). Initiation of naive B cell return to the periphery and autoreactive B cell expansion leading to relapse after RTX may therefore be linked to interactions between BAFF and BAFF-binding receptors (BBR). Relationships between serum BAFF and BBR expression [(BAFFR, calcium signal modulating cyclophilic ligand interactor (TACI) and B cell maturation antigen (BCMA)] were determined on B cell subsets, defined using immunoglobulin (Ig)D/CD38. Twenty pre-RTX and 18 RA patients relapsing after B cell depletion were included. Results were analysed with respect to timing of relapse up to 7 months after peripheral B cell return (≥ 5 B cells/μl) and to serum BAFF levels. After B cell return, B cell populations from relapsing patients had significantly lower BAFFR + expression compared to HC and pre-RTX patients. The percentage of BAFFR + B cells increased with time after B cell return and was correlated inversely with serum BAFF levels. BAFFR expression remained reduced. The percentage of TACI + memory B cells were lower in RA patients after RTX compared with healthy controls (HC). BCMA expression (% and expression) did not differ between patients and HC. Relapse following B cell return appeared largely independent of the percentage of BAFFR + or percentage of BCMA + B cells or serum BAFF levels. The lower percentage of TACI + memory B cells may reduce inhibitory signalling for B cell differentiation. In patients relapsing at longer periods after B cell return, recovery of the B cell pool was more complete, suggesting that selection or expansion of autoreactive B cells may be needed to precipitate relapse. © 2017 British Society for Immunology.

  3. B-Cell-Activating Factor and the B-Cell Compartment in HIV/SIV Infection

    Science.gov (United States)

    Borhis, Gwenoline; Trovato, Maria; Chaoul, Nada; Ibrahim, Hany M.; Richard, Yolande

    2017-01-01

    With the goal to design effective HIV vaccines, intensive studies focused on broadly neutralizing antibodies, which arise in a fraction of HIV-infected people. Apart from identifying new vulnerability sites in the viral envelope proteins, these studies have shown that a fraction of these antibodies are produced by self/poly-reactive B-cells. These findings prompted us to revisit the B-cell differentiation and selection process during HIV/SIV infection and to consider B-cells as active players possibly shaping the helper T-cell program within germinal centers (GCs). In this context, we paid a particular attention to B-cell-activating factor (BAFF), a key cytokine in B-cell development and immune response that is overproduced during HIV/SIV infection. As it does in autoimmune diseases, BAFF excess might contribute to the abnormal rescue of self-reactive B-cells at several checkpoints of the B-cell development and impair memory B-cell generation and functions. In this review, we first point out what is known about the functions of BAFF/a proliferation-inducing ligand and their receptors [B-cell maturation, transmembrane activator and CAML interactor (TACI), and BAFF-R], in physiological and pathophysiological settings, in mice and humans. In particular, we highlight recent results on the previously underappreciated regulatory functions of TACI and on the highly regulated production of soluble TACI and BAFF-R that act as decoy receptors. In light of recent data on BAFF, TACI, and BAFF-R, we then revisit the altered phenotypes and functions of B-cell subsets during the acute and chronic phase of HIV/SIV infection. Given the atypical phenotype and reduced functions of memory B-cells in HIV/SIV infection, we particularly discuss the GC reaction, a key checkpoint where self-reactive B-cells are eliminated and pathogen-specific memory B-cells and plasmablasts/cells are generated in physiological settings. Through its capacity to differentially bind and process BAFF-R and

  4. Characterising B cell numbers and memory B cells in HIV infected and uninfected Malawian adults

    Directory of Open Access Journals (Sweden)

    Gordon Stephen

    2010-09-01

    Full Text Available Abstract Background Untreated human immunodeficiency virus (HIV disease disrupts B cell populations causing reduced memory and reduced naïve resting B cells leading to increases in specific co-infections and impaired responses to vaccines. To what extent antiretroviral treatment reverses these changes in an African population is uncertain. Methods A cross-sectional study was performed. We recruited HIV-uninfected and HIV-infected Malawian adults both on and off antiretroviral therapy attending the Queen Elizabeth Central hospital in Malawi. Using flow cytometry, we enumerated B cells and characterized memory B cells and compared these measurements by the different recruitment groups. Results Overall 64 participants were recruited - 20 HIV uninfected (HIV-, 30 HIV infected ART naïve (HIV+N and 14 HIV-infected ART treated (HIV+T. ART treatment had been taken for a median of 33 months (Range 12-60 months. Compared to HIV- the HIV+N adults had low absolute number of naïve resting B cells (111 vs. 180 cells/μl p = 0.008; reduced memory B cells (27 vs. 51 cells/μl p = 0.0008. The HIV+T adults had B-cell numbers similar to HIV- except for memory B cells that remained significantly lower (30 vs. 51 cells/μl p = 0.02. In the HIV+N group we did not find an association between CD4 count and B cell numbers. Conclusions HIV infected Malawian adults have abnormal B-cell numbers. Individuals treated with ART show a return to normal in B-cell numbers but a persistent deficit in the memory subset is noted. This has important implications for long term susceptibility to co-infections and should be evaluated further in a larger cohort study.

  5. The BAFF receptor TACI controls IL-10 production by regulatory B cells and CLL B cells

    Science.gov (United States)

    Saulep-Easton, Damien; Vincent, Fabien B.; Quah, Pin Shie; Wei, Andrew; Ting, Stephen B.; Croce, Carlo M.; Tam, Constantine; Mackay, Fabienne

    2015-01-01

    Interleukin (IL)-10-producing B cells (B10 cells) have emerged as important regulatory players with immunosuppressive roles. Chronic lymphocytic leukemia (CLL) B cells also secrete IL-10 and share features of B10 cells, suggesting a possible contribution of CLL B cells to immunosuppression in CLL patients. Factors controlling the emergence of B10 cells are not known. B cell-activating factor of the tumour necrosis factor (TNF) family (BAFF) is critical for B cell maturation and survival, and is implicated in the development and progression of CLL. We sought to investigate the role of BAFF in the emergence of IL-10-producing B regulatory cells in healthy donors and CLL patients. Here, we report that BAFF signaling promotes IL-10 production by CLL B cells in a mouse model of CLL and in CLL patients. Moreover, BAFF-mediated IL-10 production by normal and CLL B cells is mediated via its receptor TACI. Our work uncovered a major targetable pathway important for the generation of regulatory B cells that is detrimental to immunity in CLL. PMID:26139429

  6. Persistent Polyclonal B Cell Lymphocytosis B Cells Can Be Activated through CD40-CD154 Interaction

    Directory of Open Access Journals (Sweden)

    Emmanuelle Dugas-Bourdages

    2014-01-01

    Full Text Available Persistent polyclonal B cell lymphocytosis (PPBL is a rare disorder, diagnosed primarily in adult female smokers and characterized by an expansion of CD19+CD27+IgM+ memory B cells, by the presence of binucleated lymphocytes, and by a moderate elevation of serum IgM. The clinical course is usually benign, but it is not known whether or not PPBL might be part of a process leading to the emergence of a malignant proliferative disorder. In this study we sought to investigate the functional response of B cells from patients with PPBL by use of an optimal memory B cell culture model based on the CD40-CD154 interaction. We found that the proliferation of PPBL B cells was almost as important as that of B cells from normal controls, resulting in high immunoglobulin secretion with in vitro isotypic switching. We conclude that the CD40-CD154 activation pathway is functional in the memory B cell population of PPBL patients, suggesting that the disorder may be due to either a dysfunction of other cells in the microenvironment or a possible defect in another B cell activation pathway.

  7. FOXP1 suppresses immune response signatures and MHC class II expression in activated B-cell-like diffuse large B-cell lymphomas

    DEFF Research Database (Denmark)

    Brown, P J; Wong, K K; Felce, S L

    2016-01-01

    The FOXP1 (forkhead box P1) transcription factor is a marker of poor prognosis in diffuse large B-cell lymphoma (DLBCL). Here microarray analysis of FOXP1-silenced DLBCL cell lines identified differential regulation of immune response signatures and major histocompatibility complex class II (MHC II......-DRA, there was an inverse correlation with the frequency (P=0.0456) and intensity (P=0.0349) of FOXP1 expression. We propose that FOXP1 represents a novel regulator of genes targeted by the class II MHC transactivator CIITA (MHC II and CD74) and therapeutically targeting the FOXP1 pathway may improve antigen presentation......) genes as some of the most significant differences between germinal center B-cell (GCB)-like DLBCL with full-length FOXP1 protein expression versus activated B-cell (ABC)-like DLBCL expressing predominantly short FOXP1 isoforms. In an independent primary DLBCL microarray data set, multiple MHC II genes...

  8. Unusual B cell morphology in inflammatory bowel disease.

    Science.gov (United States)

    Defendenti, Caterina; Grosso, Silvia; Atzeni, Fabiola; Croce, Annamaria; Senesi, Olivia; Saibeni, Simone; Bollani, Simona; Almasio, Piero Luigi; Bruno, Savino; Sarzi-Puttini, Piercarlo

    2012-07-15

    B lymphocytes express various different types of surface immunoglobulins that are largely unrelated to other hematological lines, although some reports have described a relationship between malignant B cells and other cells such as macrophages. Multiple genes of hematopoietic lineage, including transcription factors, are co-expressed in hematopoietic stem cells and progenitors, a phenomenon referred to as "lineage priming". Changes in the expression levels and timing of transcription factors can induce the lineage conversion of committed cells, which indicates that the regulation of transcription factors might be particularly critical for maintaining hierarchical hematopoietic development. The aim of this study was to evaluate the surface markers of particular IgM-positive and irregularly nucleated cells detected in patients with inflammatory bowel disease (IBD), and to assess their association with diagnosis and inflammatory cell recruitment. Small intestine, colon and rectal biopsy specimens of 96 IBD patients were studied. Immunoglobulin-producing cells (IPCs) were analyzed by means of immunofluorescence using polyclonal rabbit anti-human Ig and goat anti-human IgM. The specimens positive for B cells with irregular nuclei were assessed using monoclonal antibodies specific for CD79, and λ and κ chains in order to confirm their B cell nature. CD15+ cells, an important marker of inflammatory cell recruitment, were also evaluated. Statistical correlations were sought between the histological findings and clinical expression. 34 (35.4%) of the 96 patients (64 with ulcerative colitis and 32 with Crohn's disease) presented a periglandial localization of IPCs with irregular nuclei, which showed surface markers specific for the B cell subset, such as IgM and CD79, but quantitative differences in λ and κ chains. These specimens also contained CD15-positive cells, which are usually absent in healthy controls. The quantitative aspects and localization of the CD15

  9. Large anaplastic spinal B-cell lymphoma in a cat.

    Science.gov (United States)

    Flatland, Bente; Fry, Michael M; Newman, Shelley J; Moore, Peter F; Smith, Joanne R; Thomas, William B; Casimir, Roslyn H

    2008-12-01

    A 5-year-old female spayed domestic shorthair cat was presented for evaluation of tetraparesis. The neurologic lesion was localized to the cervical spinal segment (C1-C6). A left axillary mass was identified, and the results of fine needle aspiration cytology indicated malignant round cell neoplasia of possible histiocytic origin. The cells were large, had marked anisocytosis and anisokaryosis, occasional bi- and multinucleation, and cytoplasmic vacuolation. Euthanasia was performed due to the poor prognosis associated with severe, progressive neurologic signs and a malignant neoplasm. Postmortem examination revealed spinal cord compression and an extradural mass at the C1-C2 spinal segment, with neoplastic cells in the adjacent vertebral bodies, surrounding skeletal muscle, left axillary lymph node, and bone marrow from the right femur. The initial histologic diagnosis was anaplastic sarcoma, but immunohistochemical results indicated the cells were CD20+ and CD45R+ and CD3-, compatible with a diagnosis of B-cell lymphoma. CD79a staining was nonspecific and uninterpretable. Weak to moderate CD18 positivity and E-cadherin positivity were also observed. Clonality of the B-cell population could not be demonstrated using PCR testing for antigen receptor gene rearrangement. To the authors' knowledge, this is the first reported case of a feline spinal anaplastic B-cell lymphoma exhibiting bi- and multinucleated cells. The prognostic significance of this cell morphology and immunophenotype is unknown.

  10. Dynamic EBF1 occupancy directs sequential epigenetic and transcriptional events in B-cell programming.

    Science.gov (United States)

    Li, Rui; Cauchy, Pierre; Ramamoorthy, Senthilkumar; Boller, Sören; Chavez, Lukas; Grosschedl, Rudolf

    2018-01-15

    B-cell fate determination requires the action of transcription factors that operate in a regulatory network to activate B-lineage genes and repress lineage-inappropriate genes. However, the dynamics and hierarchy of events in B-cell programming remain obscure. To uncouple the dynamics of transcription factor expression from functional consequences, we generated induction systems in developmentally arrested Ebf1 -/- pre-pro-B cells to allow precise experimental control of EBF1 expression in the genomic context of progenitor cells. Consistent with the described role of EBF1 as a pioneer transcription factor, we show in a time-resolved analysis that EBF1 occupancy coincides with EBF1 expression and precedes the formation of chromatin accessibility. We observed dynamic patterns of EBF1 target gene expression and sequential up-regulation of transcription factors that expand the regulatory network at the pro-B-cell stage. A continuous EBF1 function was found to be required for Cd79a promoter activity and for the maintenance of an accessible chromatin domain that is permissive for binding of other transcription factors. Notably, transient EBF1 occupancy was detected at lineage-inappropriate genes prior to their silencing in pro-B cells. Thus, persistent and transient functions of EBF1 allow for an ordered sequence of epigenetic and transcriptional events in B-cell programming. © 2018 Li et al.; Published by Cold Spring Harbor Laboratory Press.

  11. Cladribine treatment of multiple sclerosis is associated with depletion of memory B cells.

    Science.gov (United States)

    Ceronie, Bryan; Jacobs, Benjamin M; Baker, David; Dubuisson, Nicolas; Mao, Zhifeng; Ammoscato, Francesca; Lock, Helen; Longhurst, Hilary J; Giovannoni, Gavin; Schmierer, Klaus

    2018-03-17

    The mechanism of action of oral cladribine, recently licensed for relapsing multiple sclerosis, is unknown. To determine whether cladribine depletes memory B cells consistent with our recent hypothesis that effective, disease-modifying treatments act by physical/functional depletion of memory B cells. A cross-sectional study examined 40 people with multiple sclerosis at the end of the first cycle of alemtuzumab or injectable cladribine. The relative proportions and absolute numbers of peripheral blood B lymphocyte subsets were measured using flow cytometry. Cell-subtype expression of genes involved in cladribine metabolism was examined from data in public repositories. Cladribine markedly depleted class-switched and unswitched memory B cells to levels comparable with alemtuzumab, but without the associated initial lymphopenia. CD3 + T cell depletion was modest. The mRNA expression of metabolism genes varied between lymphocyte subsets. A high ratio of deoxycytidine kinase to group I cytosolic 5' nucleotidase expression was present in B cells and was particularly high in mature, memory and notably germinal centre B cells, but not plasma cells. Selective B cell cytotoxicity coupled with slow repopulation kinetics results in long-term, memory B cell depletion by cladribine. These may offer a new target, possibly with potential biomarker activity, for future drug development.

  12. A recurrent dominant negative E47 mutation causes agammaglobulinemia and BCR– B cells

    Science.gov (United States)

    Boisson, Bertrand; Wang, Yong-Dong; Bosompem, Amma; Ma, Cindy S.; Lim, Annick; Kochetkov, Tatiana; Tangye, Stuart G.; Casanova, Jean-Laurent; Conley, Mary Ellen

    2013-01-01

    Approximately 90% of patients with isolated agammaglobulinemia and failure of B cell development have mutations in genes required for signaling through the pre–B cell and B cell receptors. The nature of the gene defect in the majority of remaining patients is unknown. We recently identified 4 patients with agammaglobulinemia and markedly decreased numbers of peripheral B cells. The B cells that could be detected had an unusual phenotype characterized by the increased expression of CD19 but the absence of a B cell receptor. Genetic studies demonstrated that all 4 patients had the exact same de novo mutation in the broadly expressed transcription factor E47. The mutant protein (E555K) was stable in patient-derived EBV-transformed cell lines and cell lines transfected with expression vectors. E555K in the transfected cells localized normally to the nucleus and resulted in a dominant negative effect when bound to DNA as a homodimer with wild-type E47. Mutant E47 did permit DNA binding by a tissue-specific heterodimeric DNA-binding partner, myogenic differentiation 1 (MYOD). These findings document a mutational hot-spot in E47 and represent an autosomal dominant form of agammaglobulinemia. Further, they indicate that E47 plays a critical role in enforcing the block in development of B cell precursors that lack functional antigen receptors. PMID:24216514

  13. A recurrent dominant negative E47 mutation causes agammaglobulinemia and BCR(-) B cells.

    Science.gov (United States)

    Boisson, Bertrand; Wang, Yong-Dong; Bosompem, Amma; Ma, Cindy S; Lim, Annick; Kochetkov, Tatiana; Tangye, Stuart G; Casanova, Jean-Laurent; Conley, Mary Ellen

    2013-11-01

    Approximately 90% of patients with isolated agammaglobulinemia and failure of B cell development have mutations in genes required for signaling through the pre–B cell and B cell receptors. The nature of the gene defect in the majority of remaining patients is unknown. We recently identified 4 patients with agammaglobulinemia and markedly decreased numbers of peripheral B cells. The B cells that could be detected had an unusual phenotype characterized by the increased expression of CD19 but the absence of a B cell receptor. Genetic studies demonstrated that all 4 patients had the exact same de novo mutation in the broadly expressed transcription factor E47. The mutant protein (E555K) was stable in patient-derived EBV-transformed cell lines and cell lines transfected with expression vectors. E555K in the transfected cells localized normally to the nucleus and resulted in a dominant negative effect when bound to DNA as a homodimer with wild-type E47. Mutant E47 did permit DNA binding by a tissue-specific heterodimeric DNA-binding partner, myogenic differentiation 1 (MYOD). These findings document a mutational hot-spot in E47 and represent an autosomal dominant form of agammaglobulinemia. Further, they indicate that E47 plays a critical role in enforcing the block in development of B cell precursors that lack functional antigen receptors.

  14. Interaction of Staphylococci with Human B cells.

    Directory of Open Access Journals (Sweden)

    Tyler K Nygaard

    Full Text Available Staphylococcus aureus is a leading cause of human infections worldwide. The pathogen produces numerous molecules that can interfere with recognition and binding by host innate immune cells, an initial step required for the ingestion and subsequent destruction of microbes by phagocytes. To better understand the interaction of this pathogen with human immune cells, we compared the association of S. aureus and S. epidermidis with leukocytes in human blood. We found that a significantly greater proportion of B cells associated with S. epidermidis relative to S. aureus. Complement components and complement receptors were important for the binding of B cells with S. epidermidis. Experiments using staphylococci inactivated by ultraviolet radiation and S. aureus isogenic deletion mutants indicated that S. aureus secretes molecules regulated by the SaeR/S two-component system that interfere with the ability of human B cells to bind this bacterium. We hypothesize that the relative inability of B cells to bind S. aureus contributes to the microbe's success as a human pathogen.

  15. Immunoglobulins, antibody repertoire and B cell development

    Czech Academy of Sciences Publication Activity Database

    Butler, J. E.; Zhao, Y.; Šinkora, Marek; Wertz, N.; Kacskovics, I.

    2009-01-01

    Roč. 33, č. 3 (2009), s. 321-333 ISSN 0145-305X R&D Projects: GA ČR GA523/07/0088 Institutional research plan: CEZ:AV0Z50200510 Keywords : swine * immunoglobulin * b cell Subject RIV: EC - Immunology Impact factor: 3.290, year: 2009

  16. Interaction of Staphylococci with Human B cells

    Science.gov (United States)

    Nygaard, Tyler K.; Kobayashi, Scott D.; Freedman, Brett; Porter, Adeline R.; Voyich, Jovanka M.; Otto, Michael; Schneewind, Olaf; DeLeo, Frank R.

    2016-01-01

    Staphylococcus aureus is a leading cause of human infections worldwide. The pathogen produces numerous molecules that can interfere with recognition and binding by host innate immune cells, an initial step required for the ingestion and subsequent destruction of microbes by phagocytes. To better understand the interaction of this pathogen with human immune cells, we compared the association of S. aureus and S. epidermidis with leukocytes in human blood. We found that a significantly greater proportion of B cells associated with S. epidermidis relative to S. aureus. Complement components and complement receptors were important for the binding of B cells with S. epidermidis. Experiments using staphylococci inactivated by ultraviolet radiation and S. aureus isogenic deletion mutants indicated that S. aureus secretes molecules regulated by the SaeR/S two-component system that interfere with the ability of human B cells to bind this bacterium. We hypothesize that the relative inability of B cells to bind S. aureus contributes to the microbe’s success as a human pathogen. PMID:27711145

  17. NF-κB p50 activation associated with immune dysregulation confers poorer survival for diffuse large B-cell lymphoma patients with wild-type p53

    DEFF Research Database (Denmark)

    Cai, Qingqing; Tu, Meifeng; Xu-Monette, Zijun Y

    2017-01-01

    with activated B-cell-like diffuse large B-cell lymphoma. It was also an adverse prognostic factor in patients with wild-type TP53 independent of the activated B-cell-like and germinal center B-cell-like subtypes, even though p50 activation correlated with significantly lower levels of Myc, PI3K, phospho......-AKT, and CXCR4 expression and less frequent BCL2 translocations. In contrast, in germinal center B-cell-like diffuse large B-cell lymphoma patients with TP53 mutations, p50(+) nuclear expression correlated with significantly better clinical outcomes, and decreased p53, Bcl-2, and Myc expression. Gene expression...

  18. Quantitative Analysis of Repertoire-Scale Immunoglobulin Properties in Vaccine-Induced B-Cell Responses

    Science.gov (United States)

    2017-05-10

    following the recombination of discrete variable (V), 41 diverse ( D ) and joining (J) immunoglobulin (Ig) gene segments into a diverse library of B-cells...Quantitative analysis of repertoire-scale immunoglobulin properties in vaccine-induced B-cell responses Ilja V. Khavrutskii1, Sidhartha Chaudhury*1...qualitative trends in immunoglobulin (Ig) properties, such as V-family usage or 21 somatic hypermutation (SHM) rates, and in reducing the complex Ig

  19. Distinct transcriptomic features are associated with transitional and mature B-cell populations in the mouse spleen

    Directory of Open Access Journals (Sweden)

    Eden eKleiman

    2015-02-01

    Full Text Available Splenic transitional B-cells (T1 and T2 are selected to avoid self-reactivity and to safeguard against autoimmunity, then differentiate into mature follicular (FO-I and FO-II and marginal zone (MZ subsets. Transcriptomic analysis by RNA-seq of the five B-cell subsets revealed T1 cell signature genes included RAG suggesting a potential for receptor revision. T1 to T2 B-cell differentiation was marked by a switch from Myb to Myc, increased expression of the PI3K adapter DAP10 and MHC class II. FO-II may be an intermediate in FO-I differentiation and may also become MZ B-cells as suggested by principal component analysis (PCA. MZ B-cells possessed the most distinct transcriptome including downregulation of CD45 phosphatase-associated protein (CD45-AP/PTPRC-AP, as well as upregulation of IL-9R and innate molecules TLR3, TLR7 and bactericidal Perforin-2 (MPEG1. Among the endosomal TLRs, stimulation via TLR3 further enhanced Perforin-2 expression exclusively in MZ B-cells. Using gene-deleted and overexpressing transgenic mice we show that IL-9/IL-9R interaction resulted in rapid activation of STAT1, 3 and 5, primarily in MZ B-cells. Importantly, CD45-AP mutant mice had reduced transitional and increased mature MZ and FO B-cells, suggesting that it prevents premature entry of transitional B-cells to the mature B-cell pool or their survival and proliferation. Together, these findings suggest, developmental plasticity among splenic B-cell subsets, potential for receptor revision in peripheral tolerance whereas enhanced metabolism coincides with T2 to mature B-cell differentiation. Further, unique core transcriptional signatures in MZ B-cells may control their innate features.

  20. Defining B cell immunodominance to viruses.

    Science.gov (United States)

    Angeletti, Davide; Gibbs, James S; Angel, Matthew; Kosik, Ivan; Hickman, Heather D; Frank, Gregory M; Das, Suman R; Wheatley, Adam K; Prabhakaran, Madhu; Leggat, David J; McDermott, Adrian B; Yewdell, Jonathan W

    2017-04-01

    Immunodominance (ID) defines the hierarchical immune response to competing antigens in complex immunogens. Little is known regarding B cell and antibody ID despite its importance in immunity to viruses and other pathogens. We show that B cells and serum antibodies from inbred mice demonstrate a reproducible ID hierarchy to the five major antigenic sites in the influenza A virus hemagglutinin globular domain. The hierarchy changed as the immune response progressed, and it was dependent on antigen formulation and delivery. Passive antibody transfer and sequential infection experiments demonstrated 'original antigenic suppression', a phenomenon in which antibodies suppress memory responses to the priming antigenic site. Our study provides a template for attaining deeper understanding of antibody ID to viruses and other complex immunogens.

  1. B Cell-Activating Factor Regulates Different Aspects of B Cell Functionality and Is Produced by a Subset of Splenic B Cells in Teleost Fish

    Science.gov (United States)

    Tafalla, Carolina; González, Lucia; Castro, Rosario; Granja, Aitor G.

    2017-01-01

    In mammals, B cell functionality is greatly influenced by cytokines released by innate cells, such as macrophages or dendritic cells, upon the early recognition of common pathogen patterns through invariant receptors. B cell-activating factor (BAFF) is one of these innate B cell-helper signals and plays a key role in the survival and differentiation of B cells. Although, evolutionarily, teleost fish constitute the first animal group in which adaptive immunity based on Ig receptors is present, fish still rely greatly on innate responses. In this context, we hypothesized that BAFF would play a key role in the control of B cell responses in fish. Supporting this, our results show that teleost BAFF recapitulates mammalian BAFF stimulating actions on B cells, upregulating the expression of membrane MHC II, improving the survival of fish naïve B cells and antibody-secreting cells, and increasing the secretion of IgM. Surprisingly, we also demonstrate that BAFF is not only produced in fish by myeloid cells but is also produced by a subset of splenic B cells. Thus, if this B cell-produced BAFF proves to be actively regulating this same B cell subset, our findings point to an ancient mechanism to control B cell differentiation and survival in lower vertebrates, which has been silenced in mammals in physiological conditions, but reemerges under pathological conditions, such as B cell lymphomas and autoimmune diseases. PMID:28360916

  2. Superenhancer reprogramming drives a B-cell-epithelial transition and high-risk leukemia.

    Science.gov (United States)

    Hu, Yeguang; Zhang, Zhihong; Kashiwagi, Mariko; Yoshida, Toshimi; Joshi, Ila; Jena, Nilamani; Somasundaram, Rajesh; Emmanuel, Akinola Olumide; Sigvardsson, Mikael; Fitamant, Julien; El-Bardeesy, Nabeel; Gounari, Fotini; Van Etten, Richard A; Georgopoulos, Katia

    2016-09-01

    IKAROS is required for the differentiation of highly proliferative pre-B-cell precursors, and loss of IKAROS function indicates poor prognosis in precursor B-cell acute lymphoblastic leukemia (B-ALL). Here we show that IKAROS regulates this developmental stage by positive and negative regulation of superenhancers with distinct lineage affiliations. IKAROS defines superenhancers at pre-B-cell differentiation genes together with B-cell master regulators such as PAX5, EBF1, and IRF4 but is required for a highly permissive chromatin environment, a function that cannot be compensated for by the other transcription factors. IKAROS is also highly enriched at inactive enhancers of genes normally expressed in stem-epithelial cells. Upon IKAROS loss, expression of pre-B-cell differentiation genes is attenuated, while a group of extralineage transcription factors that are directly repressed by IKAROS and depend on EBF1 relocalization at their enhancers for expression is induced. LHX2, LMO2, and TEAD-YAP1, normally kept separate from native B-cell transcription regulators by IKAROS, now cooperate directly with them in a de novo superenhancer network with its own feed-forward transcriptional reinforcement. Induction of de novo superenhancers antagonizes Polycomb repression and superimposes aberrant stem-epithelial cell properties in a B-cell precursor. This dual mechanism of IKAROS regulation promotes differentiation while safeguarding against a hybrid stem-epithelial-B-cell phenotype that underlies high-risk B-ALL. © 2016 Hu et al.; Published by Cold Spring Harbor Laboratory Press.

  3. Applied Protein and Molecular Techniques for Characterization of B Cell Neoplasms in Horses

    Science.gov (United States)

    Badial, Peres R.; Tallmadge, Rebecca L.; Miller, Steven; Stokol, Tracy; Richards, Kristy; Borges, Alexandre S.

    2015-01-01

    Mature B cell neoplasms cover a spectrum of diseases involving lymphoid tissues (lymphoma) or blood (leukemia), with an overlap between these two presentations. Previous studies describing equine lymphoid neoplasias have not included analyses of clonality using molecular techniques. The objective of this study was to use molecular techniques to advance the classification of B cell lymphoproliferative diseases in five adult equine patients with a rare condition of monoclonal gammopathy, B cell leukemia, and concurrent lymphadenopathy (lymphoma/leukemia). The B cell neoplasms were phenotypically characterized by gene and cell surface molecule expression, secreted immunoglobulin (Ig) isotype concentrations, Ig heavy-chain variable (IGHV) region domain sequencing, and spectratyping. All five patients had hyperglobulinemia due to IgG1 or IgG4/7 monoclonal gammopathy. Peripheral blood leukocyte immunophenotyping revealed high proportions of IgG1- or IgG4/7-positive cells and relative T cell lymphopenia. Most leukemic cells lacked the surface B cell markers CD19 and CD21. IGHG1 or IGHG4/7 gene expression was consistent with surface protein expression, and secreted isotype and Ig spectratyping revealed one dominant monoclonal peak. The mRNA expression of the B cell-associated developmental genes EBF1, PAX5, and CD19 was high compared to that of the plasma cell-associated marker CD38. Sequence analysis of the IGHV domain of leukemic cells revealed mutated Igs. In conclusion, the protein and molecular techniques used in this study identified neoplastic cells compatible with a developmental transition between B cell and plasma cell stages, and they can be used for the classification of equine B cell lymphoproliferative disease. PMID:26311245

  4. Primary Hepatosplenic Large B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    M.R. Morales-Polanco

    2008-03-01

    Full Text Available Diffuse large B-cell lymphoma is the most common form of lymphoma. It usually begins in the lymph nodes; up to 40% may have an extranodal presentation. According to a definition of primary extranodal lymphoma with presentation only in extranodal sites, there are reports of large B-cell lymphomas limited to liver or spleen as separate entities, and to date there have been only three documented cases of primary hepatosplenic presentation. This paper reports a fourth case. Due to a review of the literature and the clinical course of the case reported, we conclude that primary hepatosplenic large B-cell lymphoma has been found predominantly in females older than 60 years. The patients reported had <2 months of evolution prior to diagnosis, prominent B symptoms, splenomegaly in three and hepatomegaly in two, none with lymph node involvement. All had thrombocytopenia and abnormal liver function tests; three had anemia and elevated serum lactic dehydrogenase levels, two with hemophagocytosis in bone marrow. Because of the previously mentioned data, it can be stated that primary hepatosplenic lymphoma is an uncommon and aggressive form of disease that requires immediate recognition and treatment.

  5. Cross Talk between Immunoglobulin Heavy-Chain Transcription and RNA Surveillance during B Cell Development

    Science.gov (United States)

    Tinguely, Aurélien; Chemin, Guillaume; Péron, Sophie; Sirac, Christophe; Reynaud, Stéphane; Cogné, Michel

    2012-01-01

    Immunoglobulin (Ig) genes naturally acquire frequent premature termination codons during the error-prone V(D)J recombination process. Although B cell differentiation is linked to the expression of productive Ig alleles, the transcriptional status of nonfunctionally recombined alleles remains unclear. Here, we tracked transcription and posttranscriptional regulation for both Ig heavy-chain (IgH) alleles in mice carrying a nonfunctional knock-in allele. We show that productively and nonproductively VDJ-rearranged alleles are transcribed throughout B cell development, carry similar active chromatin marks, and even display equivalent RNA polymerase II (RNAPII) loading after B cell stimulation. Hence, these results challenge the idea that the repositioning of one allele to heterochromatin could promote the silencing of nonproductive alleles. Interestingly, the efficiency of downstream RNA surveillance mechanisms fluctuates according to B cell activation and terminal differentiation: unspliced nonfunctional transcripts accumulate in primary B cells, while B cell activation promotes IgH transcription, RNA splicing, and nonsense-mediated mRNA decay (NMD). Altogether, IgH transcription and RNA splicing rates determine by which RNA surveillance mechanisms a B cell can get rid of nonproductive IgH mRNAs. PMID:22037763

  6. Impairment of mature B-cell maintenance upon combined deletion of the alternative NF-κB transcription factors RELB and NF-κB2 in B cells$

    Science.gov (United States)

    De Silva, Nilushi S.; Silva, Kathryn; Anderson, Michael M.; Bhagat, Govind; Klein, Ulf

    2016-01-01

    B-cell activating factor (BAFF) is critical for the survival and maturation of mature B-cells. BAFF, via the BAFF receptor (BAFFR), activates multiple signaling pathways in B-cells, including the alternative nuclear factor-κB (NF-κB) pathway. The transcription factors RELB and NF-κB2 (p100/p52) are the downstream mediators of the alternative pathway; however, the B-cell-intrinsic functions of these NF-κB subunits have not been studied in vivo using conditional alleles, either individually or in combination. We here report that B-cell-specific deletion of relb led to only a slight decrease in the fraction of mature splenic B cells, whereas deletion of nfkb2 caused a marked reduction. This phenotype was further exacerbated upon combined deletion of relb and nfkb2 and most dramatically affected the maintenance of marginal zone B-cells. BAFF-stimulation, in contrast to CD40-activation, was unable to rescue relb/nfkb2-deleted B-cells in vitro. RNA-sequencing analysis of BAFF-stimulated nfkb2-deleted vs. normal B-cells suggests that the alternative NF-κB pathway, in addition to its critical role in BAFF-mediated cell survival, may control the expression of genes involved in the positioning of B-cells within the lymphoid microenvironment and in the establishment of T-cell-B-cell interactions. Thus, by ablating the downstream transcription factors of the alternative NF-κB pathway specifically in B-cells, we here identify a critical role for the combined activity of the RELB and NF-κB2 subunits in B-cell homeostasis that cannot be compensated for by the canonical NF-κB pathway under physiological conditions. PMID:26851215

  7. Positive intergenic feedback circuitry, involving EBF1 and FOXO1, orchestrates B-cell fate.

    Science.gov (United States)

    Mansson, Robert; Welinder, Eva; Åhsberg, Josefine; Lin, Yin C; Benner, Christopher; Glass, Christopher K; Lucas, Joseph S; Sigvardsson, Mikael; Murre, Cornelis

    2012-12-18

    Recent studies have identified a number of transcriptional regulators, including E2A, early B-cell factor 1 (EBF1), FOXO1, and paired box gene 5 (PAX5), that promote early B-cell development. However, how this ensemble of regulators mechanistically promotes B-cell fate remains poorly understood. Here we demonstrate that B-cell development in FOXO1-deficient mice is arrested in the common lymphoid progenitor (CLP) LY6D(+) cell stage. We demonstrate that this phenotype closely resembles the arrest in B-cell development observed in EBF1-deficient mice. Consistent with these observations, we find that the transcription signatures of FOXO1- and EBF1-deficient LY6D(+) progenitors are strikingly similar, indicating a common set of target genes. Furthermore, we found that depletion of EBF1 expression in LY6D(+) CLPs severely affects FOXO1 mRNA abundance, whereas depletion of FOXO1 activity in LY6D(+) CLPs ablates EBF1 transcript levels. We generated a global regulatory network from EBF1 and FOXO1 genome-wide transcription factor occupancy and transcription signatures derived from EBF1- and FOXO1-deficient CLPs. This analysis reveals that EBF1 and FOXO1 act in a positive feedback circuitry to promote and stabilize specification to the B-cell lineage.

  8. The Role of c-MYC in B-Cell Lymphomas: Diagnostic and Molecular Aspects.

    Science.gov (United States)

    Nguyen, Lynh; Papenhausen, Peter; Shao, Haipeng

    2017-04-05

    c-MYC is one of the most essential transcriptional factors, regulating a diverse array of cellular functions, including proliferation, growth, and apoptosis. Dysregulation of c-MYC is essential in the pathogenesis of a number of B-cell lymphomas, but is rarely reported in T-cell lymphomas. c-MYC dysregulation induces lymphomagenesis by loss of the tight control of c-MYC expression, leading to overexpression of intact c-MYC protein, in contrast to the somatic mutations or fusion proteins seen in many other oncogenes. Dysregulation of c-MYC in B-cell lymphomas occurs either as a primary event in Burkitt lymphoma, or secondarily in aggressive lymphomas such as diffuse large B-cell lymphoma, plasmablastic lymphoma, mantle cell lymphoma, or double-hit lymphoma. Secondary c-MYC changes include gene translocation and gene amplification, occurring against a background of complex karyotype, and most often confer aggressive clinical behavior, as evidenced in the double-hit lymphomas. In low-grade B-cell lymphomas, acquisition of c-MYC rearrangement usually results in transformation into highly aggressive lymphomas, with some exceptions. In this review, we discuss the role that c-MYC plays in the pathogenesis of B-cell lymphomas, the molecular alterations that lead to c-MYC dysregulation, and their effect on prognosis and diagnosis in specific types of B-cell lymphoma.

  9. Atypical and classical memory B cells produce Plasmodium falciparum neutralizing antibodies

    DEFF Research Database (Denmark)

    Muellenbeck, Matthias F; Ueberheide, Beatrix; Amulic, Borko

    2013-01-01

    Antibodies can protect from Plasmodium falciparum (Pf) infection and clinical malaria disease. However, in the absence of constant reexposure, serum immunoglobulin (Ig) levels rapidly decline and full protection from clinical symptoms is lost, suggesting that B cell memory is functionally impaired....... We show at the single cell level that natural Pf infection induces the development of classical memory B cells (CM) and atypical memory B cells (AtM) that produce broadly neutralizing antibodies against blood stage Pf parasites. CM and AtM contribute to anti-Pf serum IgG production, but only AtM show...... signs of active antibody secretion. AtM and CM were also different in their IgG gene repertoire, suggesting that they develop from different precursors. The findings provide direct evidence that natural Pf infection leads to the development of protective memory B cell antibody responses and suggest...

  10. Reprogramming human B cells into induced pluripotent stem cells and its enhancement by C/EBPα.

    Science.gov (United States)

    Bueno, C; Sardina, J L; Di Stefano, B; Romero-Moya, D; Muñoz-López, A; Ariza, L; Chillón, M C; Balanzategui, A; Castaño, J; Herreros, A; Fraga, M F; Fernández, A; Granada, I; Quintana-Bustamante, O; Segovia, J C; Nishimura, K; Ohtaka, M; Nakanishi, M; Graf, T; Menendez, P

    2016-03-01

    B cells have been shown to be refractory to reprogramming and B-cell-derived induced pluripotent stem cells (iPSC) have only been generated from murine B cells engineered to carry doxycycline-inducible Oct4, Sox2, Klf4 and Myc (OSKM) cassette in every tissue and from EBV/SV40LT-immortalized lymphoblastoid cell lines. Here, we show for the first time that freshly isolated non-cultured human cord blood (CB)- and peripheral blood (PB)-derived CD19+CD20+ B cells can be reprogrammed to iPSCs carrying complete VDJH immunoglobulin (Ig) gene monoclonal rearrangements using non-integrative tetracistronic, but not monocistronic, OSKM-expressing Sendai Virus. Co-expression of C/EBPα with OSKM facilitates iPSC generation from both CB- and PB-derived B cells. We also demonstrate that myeloid cells are much easier to reprogram than B and T lymphocytes. Differentiation potential back into the cell type of their origin of B-cell-, T-cell-, myeloid- and fibroblast-iPSCs is not skewed, suggesting that their differentiation does not seem influenced by 'epigenetic memory'. Our data reflect the actual cell-autonomous reprogramming capacity of human primary B cells because biased reprogramming was avoided by using freshly isolated primary cells, not exposed to cytokine cocktails favoring proliferation, differentiation or survival. The ability to reprogram CB/PB-derived primary human B cells offers an unprecedented opportunity for studying developmental B lymphopoiesis and modeling B-cell malignancies.

  11. N-wasp is essential for the negative regulation of B cell receptor signaling.

    Directory of Open Access Journals (Sweden)

    Chaohong Liu

    2013-11-01

    Full Text Available Negative regulation of receptor signaling is essential for controlling cell activation and differentiation. In B-lymphocytes, the down-regulation of B-cell antigen receptor (BCR signaling is critical for suppressing the activation of self-reactive B cells; however, the mechanism underlying the negative regulation of signaling remains elusive. Using genetically manipulated mouse models and total internal reflection fluorescence microscopy, we demonstrate that neuronal Wiskott-Aldrich syndrome protein (N-WASP, which is coexpressed with WASP in all immune cells, is a critical negative regulator of B-cell signaling. B-cell-specific N-WASP gene deletion causes enhanced and prolonged BCR signaling and elevated levels of autoantibodies in the mouse serum. The increased signaling in N-WASP knockout B cells is concurrent with increased accumulation of F-actin at the B-cell surface, enhanced B-cell spreading on the antigen-presenting membrane, delayed B-cell contraction, inhibition in the merger of signaling active BCR microclusters into signaling inactive central clusters, and a blockage of BCR internalization. Upon BCR activation, WASP is activated first, followed by N-WASP in mouse and human primary B cells. The activation of N-WASP is suppressed by Bruton's tyrosine kinase-induced WASP activation, and is restored by the activation of SH2 domain-containing inositol 5-phosphatase that inhibits WASP activation. Our results reveal a new mechanism for the negative regulation of BCR signaling and broadly suggest an actin-mediated mechanism for signaling down-regulation.

  12. Micro RNA-98 suppresses interleukin-10 in peripheral B cells in patient post-cardio transplantation.

    Science.gov (United States)

    Song, Jiangping; Su, Wenjun; Chen, Xiao; Zhao, Qian; Zhang, Ningning; Li, Mao-Gang; Yang, Ping-Chang; Wang, Liqing

    2017-04-25

    The immune tolerance to the transplant heart survival is critical. Regulatory B cells are one of the major immune regulatory cell populations in the immune tolerance. Micro RNAs (miR) can regulate the activities of immune cells, such as the expression of interleukin (IL)-10 by B cells. This study tests a hypothesis that micro RNA (miR)-98 plays a role in the regulation of interleukin (IL)-10 expression in B cells (B10 cell) after heart transplantation. In this study, the peripheral blood samples were collected from patients before and after heart transplantation. The expression of miR-98 and IL-10 in B cells was assessed by real time RT-PCR. An allograft heart transplantation mouse model was developed. We observed that after heart transplantation, the frequency of peripheral B10 cell and the IL-10 mRNA levels in peripheral B cells were significantly decreased, the levels of miR-98 were increased in peripheral B cells and the serum levels of cortisol were increased in the patients. Treating naive B cells with cortisol in the culture suppressed the expression of IL-10 in B cells, which was abolished by knocking down the miR-98 gene. Administration with anti-miR-98, or cortisol inhibitor, or adoptive transfer with B10 cells, significantly enhanced the survival rate and time of mice received allograft heart transplantation. In conclusion, the enhancement of serum cortisol affects the immune tolerant feature of B cells, which can be attenuated by anti-miR-98-carrying liposomes.

  13. Microarray-based classification of diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Poulsen, Christian Bjørn; Borup, Rehannah; Nielsen, Finn Cilius

    2005-01-01

    OBJECTIVE: Hierarchical clusterings of diffuse large B-cell lymphoma (DLBCL) based on gene expression signatures have previously been used to classify DLBCL into Germinal Center B-cell (GCB) and Activated B-cell (ABC) types. To examine if it was feasible to perform a cross-platform validation...... for hierarchical clustering. In this way, three subtypes, including the GCB type (n = 20), the ABC type (n = 25) and an intermediate group, Type-3 (n = 5), were distinguished. The CD10 and Bcl-6 expression as well as t(14;18) translocation were prevalent, but not exclusive to the GCB type. By contrast, MUM1......;103:1862-1868) to exhibit a higher specificity than the original gene lists. CONCLUSION: We conclude that gene expression profiling with Affymetrix Genechips is efficient to distinguish between GCB and ABC types of DLBCL and that these are likely to represent separate biological entities. The Genechip platform is highly...

  14. B-Cell-Activating Factor and Autoimmune Myasthenia Gravis

    Directory of Open Access Journals (Sweden)

    Samia Ragheb

    2011-01-01

    Full Text Available BAFF is a potent B-cell survival factor, and it plays an essential role in B-cell homeostasis and B-cell function in the periphery. Both normal and autoreactive B cells are BAFF dependent; however, excess BAFF promotes the survival, growth, and maturation of autoreactive B cells. When overexpressed, BAFF protects B cells from apoptosis, thereby contributing to autoimmunity. Three independent studies have shown higher BAFF levels in the circulation of MG patients. BAFF may play an important role in the pathogenesis of MG. BAFF antagonists may well provide new treatment options for MG patients, particularly those patients with thymic lymphoid follicular hyperplasia.

  15. The mast cell-B cell axis in lung vascular remodeling and pulmonary hypertension.

    Science.gov (United States)

    Breitling, Siegfried; Hui, Zhang; Zabini, Diana; Hu, Yijie; Hoffmann, Julia; Goldenberg, Neil M; Tabuchi, Arata; Buelow, Roland; Dos Santos, Claudia; Kuebler, Wolfgang M

    2017-05-01

    Over past years, a critical role for the immune system and, in particular, for mast cells in the pathogenesis of pulmonary hypertension (PH) has emerged. However, the way in which mast cells promote PH is still poorly understood. Here, we investigated the mechanisms by which mast cells may contribute to PH, specifically focusing on the interaction between the innate and adaptive immune response and the role of B cells and autoimmunity. Experiments were performed in Sprague-Dawley rats and B cell-deficient JH-KO rats in the monocrotaline, Sugen/hypoxia, and the aortic banding model of PH. Hemodynamics, cell infiltration, IL-6 expression, and vascular remodeling were analyzed. Gene array analyses revealed constituents of immunoglobulins as most prominently regulated mast cell-dependent genes in the lung in experimental PH. IL-6 was shown to link mast cells to B cells, as 1 ) IL-6 was upregulated and colocalized with mast cells and was reduced by mast-cell stabilizers and 2 ) IL-6 or mast cell blockade reduced B cells in lungs of monocrotaline-treated rats. A functional role for B cells in PH was demonstrated in that either blocking B cells by an anti-CD20 antibody or B-cell deficiency in JH-KO rats attenuated right ventricular systolic pressure and vascular remodeling in experimental PH. We here identify a mast cell-B cell axis driven by IL-6 as a critical immune pathway in the pathophysiology of PH. Our results provide novel insights into the role of the immune system in PH, which may be therapeutically exploited by targeted immunotherapy. Copyright © 2017 the American Physiological Society.

  16. FOXO1 transcription factor: a critical effector of the PI3K-AKT axis in B-cell development.

    Science.gov (United States)

    Szydłowski, Maciej; Jabłońska, Ewa; Juszczyński, Przemysław

    2014-03-01

    B-cell development and differentiation are controlled at multiple levels by the complex interplay of specific receptors and a variety of transcription factors. Several receptors involved in regulating this process, such as IL-7R, pre-B cell receptor (pre-BCR), and BCR, share the ability to trigger the signaling via the phosphoinositide 3-kinase (PI3K)-AKT pathway. FOXO1 transcription factor, a major PI3K-AKT downstream effector, regulates the expression of genes critical for progress through consecutive steps of B-cell differentiation. FOXO1 directs or fine-tunes multiple biological functions that are crucial for differentiating cells, including the cell cycle, apoptosis, oxidative stress response or DNA damage repair. Recent studies have highlighted the key role that FOXO1 plays in the maintenance of the hematopoietic stem cell pool, regulation of progenitor commitment, development of early B-cell precursors, induction of B-cell tolerance, peripheral B-cell homeostasis, and terminal differentiation. FOXO1 deficiency impairs B-cell development, due to decreased expression of its critical target genes, that include early B-cell factor (EBF1), IL-7 receptor, recombination activating genes (RAG1 and 2), activation-induced cytidine deaminase (AID), L-selectin, and BLNK. Taken together, FOXO1 is an important node in a dynamic network of transcription factors that orchestrate B-cell differentiation and specialization. Herein, we review molecular mechanisms of the PI3K-AKT-dependent signal transduction and their impact on early B-cell development, peripheral B-cell homeostasis, and terminal differentiation.

  17. Ebf1-mediated down-regulation of Id2 and Id3 is essential for specification of the B cell lineage.

    Science.gov (United States)

    Thal, Melissa A; Carvalho, Thiago L; He, Ti; Kim, Hyung-Gyoon; Gao, Hua; Hagman, James; Klug, Christopher A

    2009-01-13

    Gene knockout experiments in mice have suggested a hierarchical model of early B cell commitment wherein E2A proteins (E47 and E12) activate early B cell factor (Ebf1), which in turn activates expression of the B cell commitment factor, Pax5. In IL-7 receptor alpha (IL-7Ralpha) knockout mice, B cell development is blocked before B-lineage commitment at the prepro-B cell stage in adult animals. In IL-7Ralpha(-/-) prepro-B cells, E47 is expressed and yet is insufficient to transcriptionally activate the putative downstream target gene, Ebf1. In this study, we show that further increases of E47 expression in IL-7Ralpha(-/-) prepro-B cells fails to activate Ebf1, but rather leads to a dramatic induction of the E2A inhibitory factors, Id2 and Id3. In contrast, enforced expression of Ebf1 in IL-7Ralpha(-/-) bone marrow potently down-regulates Id2 and Id3 mRNA expression and restores B cell differentiation in vivo. Down-regulation of both Id2 and Id3 during B cell specification is essential in that overexpression of either Id2 or Id3 in wild-type bone marrow blocks B cell specification at the prepro-B cell stage. Collectively, these studies suggest a model where Ebf1 induction specifies the B cell fate by dramatically increasing activity of E47 at the posttranslational level.

  18. NKT Cell Responses to B Cell Lymphoma.

    Science.gov (United States)

    Li, Junxin; Sun, Wenji; Subrahmanyam, Priyanka B; Page, Carly; Younger, Kenisha M; Tiper, Irina V; Frieman, Matthew; Kimball, Amy S; Webb, Tonya J

    2014-06-01

    Natural killer T (NKT) cells are a unique subset of CD1d-restricted T lymphocytes that express characteristics of both T cells and natural killer cells. NKT cells mediate tumor immune-surveillance; however, NKT cells are numerically reduced and functionally impaired in lymphoma patients. Many hematologic malignancies express CD1d molecules and co-stimulatory proteins needed to induce anti-tumor immunity by NKT cells, yet most tumors are poorly immunogenic. In this study, we sought to investigate NKT cell responses to B cell lymphoma. In the presence of exogenous antigen, both mouse and human NKT cell lines produce cytokines following stimulation by B cell lymphoma lines. NKT cell populations were examined ex vivo in mouse models of spontaneous B cell lymphoma, and it was found that during early stages, NKT cell responses were enhanced in lymphoma-bearing animals compared to disease-free animals. In contrast, in lymphoma-bearing animals with splenomegaly and lymphadenopathy, NKT cells were functionally impaired. In a mouse model of blastoid variant mantle cell lymphoma, treatment of tumor-bearing mice with a potent NKT cell agonist, α-galactosylceramide (α-GalCer), resulted in a significant decrease in disease pathology. Ex vivo studies demonstrated that NKT cells from α-GalCer treated mice produced IFN-γ following α-GalCer restimulation, unlike NKT cells from vehicle-control treated mice. These data demonstrate an important role for NKT cells in the immune response to an aggressive hematologic malignancy like mantle cell lymphoma.

  19. Association between BANK1 polymorphisms and susceptibility to autoimmune diseases: A meta-analysis.

    Science.gov (United States)

    Bae, S-C; Lee, Y H

    2017-03-31

    This study aimed to explore whether BANK1 polymorphisms are associated with susceptibility to autoimmune diseases. We conducted a meta-analysis on the associations between the BANK1 rs10516487, rs3733197, and rs17266594 polymorphisms and autoimmune diseases. Twenty-two articles with a total of 22,684 patients and 36,437 controls were included in the meta-analysis. Meta-analysis revealed a significant association between autoimmune diseases and the BANK1 rs10516487 T allele (OR = 1.161, 95% CI = 1.092-1.275, p = 1.9 × 10-6, heterogeneity pautoimmune diseases and the BANK1 rs3733197 A allele (OR = 1.178, 95% CI = 1.105-1.256, p = 4.5 × 10-7, heterogeneity p = 0.002) and the rs17266594 T allele (OR = 1.189, 95% CI = 1.073-1.315, p = 0.001, heterogeneity pautoimmune disease type revealed an association between both systemic lupus erythematosus and systemic sclerosis and the BANK1 rs10516487 T allele (OR = 1.294, 95% CI = 1.232-1.360, pautoimmune diseases.

  20. Role of Peroxisome Proliferator-Activated Receptor β/δ and B-Cell Lymphoma-6 in Regulation of Genes Involved in Metastasis and Migration in Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Jeffrey D. Coleman

    2013-01-01

    Full Text Available PPARβ/δ is a ligand-activated transcription factor that regulates various cellular functions via induction of target genes directly or in concert with its associated transcriptional repressor, BCL-6. Matrix remodeling proteinases are frequently over-expressed in pancreatic cancer and are involved with metastasis. The present study tested the hypothesis that PPARβ/δ is expressed in human pancreatic cancer cells and that its activation could regulate MMP-9, decreasing cancer cells ability to transverse the basement membrane. In human pancreatic cancer tissue there was significantly higher expression of MMP-9 and PPARβ/δ, and lower levels of BCL-6 mRNA. PPARβ/δ activation reduced the TNFα-induced expression of various genes implicated in metastasis and reduced the invasion through a basement membrane in cell culture models. Through the use of short hairpin RNA inhibitors of PPARβ/δ, BCL-6, and MMP-9, it was evident that PPARβ/δ was responsible for the ligand-dependent effects whereas BCL-6 dissociation upon GW501516 treatment was ultimately responsible for decreasing MMP-9 expression and hence invasion activity. These results suggest that PPARβ/δ plays a role in regulating pancreatic cancer cell invasion through regulation of genes via ligand-dependent release of BCL-6 and that activation of the receptor may provide an alternative therapeutic method for controlling migration and metastasis.

  1. Primary mediastinal large B-cell lymphoma.

    Science.gov (United States)

    Martelli, Maurizio; Ferreri, Andrés; Di Rocco, Alice; Ansuinelli, Michela; Johnson, Peter W M

    2017-05-01

    Primary mediastinal large B-cell lymphoma (PMLBCL) is a distinct clinical and biological disease from other types of DLBCL. It is more frequent in young female and constitutes 6%-10% of all DLBCL. PMLBCL is characterized by a diffuse proliferation of medium to large B-cells associated with sclerosis. Molecular analysis shows it to be a distinct entity from other DLBCL. Rituximab CHOP/MACOP-B-like regimens followed by mediastinal radiotherapy (RT) were associated with a 5-years PFS of 75%-85%. More intensive regimens, as DA-EPOCH-R without mediastinal RT, have shown very promising results, but this therapeutic advance needs to be confirmed in further prospective trials. The role of consolidative mediastinal RT should be still better assess in prospective comparative studies. PET-CT scan is a powerful tool to define the real quality of response and it is hoped that future prospective trials may allow its role in the de-escalation of mediastinal RT. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Control of B cell development by the histone H2A deubiquitinase MYSM1.

    Science.gov (United States)

    Jiang, Xiao-Xia; Nguyen, Quan; Chou, YuChia; Wang, Tao; Nandakumar, Vijayalakshmi; Yates, Peter; Jones, Lindsey; Wang, Lifeng; Won, Haejung; Lee, Hye-Ra; Jung, Jae U; Müschen, Markus; Huang, Xue F; Chen, Si-Yi

    2011-12-23

    Epigenetic histone modifications play critical roles in the control of gene transcription. Recently, an increasing number of histone H2A deubiquitinases have been identified and characterized. However, the physiological functions for this entire group of histone H2A deubiquitinases remain unknown. In this study, we revealed that the histone H2A deubiquitinase MYSM1 plays an essential and intrinsic role in early B cell development. MYSM1 deficiency results in a block in early B cell commitment and a defect of B cell progenitors in expression of EBF1 and other B lymphoid genes. We further demonstrated that MYSM1 derepresses EBF1 transcription in B cell progenitors by orchestrating histone modifications and transcription factor recruitment to the EBF1 locus. Thus, this study not only uncovers the essential role for MYSM1 in gene transcription during early B cell development but also underscores the biological significance of reversible epigenetic histone H2A ubiquitination. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Negative signaling in B cells: SHIP Grbs Shc.

    Science.gov (United States)

    Tridandapani, S; Kelley, T; Cooney, D; Pradhan, M; Coggeshall, K M

    1997-09-01

    Negative signaling in B cells is initiated by co-crosslinking of the antigen receptor and the Fcy receptor, resulting in cessation of B-cell signaling events and, in turn, inhibiting B-cell proliferation and antibody secretion. Here, a competitive role is proposed for SHIP in blocking the interaction of Shc with the Grb2-Sos complex of proteins that lead to Ras activation in B cells.

  4. A brief history of T cell help to B cells.

    Science.gov (United States)

    Crotty, Shane

    2015-03-01

    In celebration of the 50th anniversary of the discovery of B cells, I take a look back at the history of T cell help to B cells, which was discovered 47 years ago. In addition, I summarize and categorize the distinct molecules that are expressed by CD4(+) T cells that constitute 'help' to B cells, and particularly the molecules expressed by T follicular helper (TFH) cells, which are the specialized providers of help to B cells.

  5. Enforced expression of the transcriptional coactivator OBF1 impairs B cell differentiation at the earliest stage of development.

    Directory of Open Access Journals (Sweden)

    Alain Bordon

    Full Text Available OBF1, also known as Bob.1 or OCA-B, is a B lymphocyte-specific transcription factor which coactivates Oct1 and Oct2 on B cell specific promoters. So far, the function of OBF1 has been mainly identified in late stage B cell populations. The central defect of OBF1 deficient mice is a severely reduced immune response to T cell-dependent antigens and a lack of germinal center formation in the spleen. Relatively little is known about a potential function of OBF1 in developing B cells. Here we have generated transgenic mice overexpressing OBF1 in B cells under the control of the immunoglobulin heavy chain promoter and enhancer. Surprisingly, these mice have greatly reduced numbers of follicular B cells in the periphery and have a compromised immune response. Furthermore, B cell differentiation is impaired at an early stage in the bone marrow: a first block is observed during B cell commitment and a second differentiation block is seen at the large preB2 cell stage. The cells that succeed to escape the block and to differentiate into mature B cells have post-translationally downregulated the expression of transgene, indicating that expression of OBF1 beyond the normal level early in B cell development is deleterious. Transcriptome analysis identified genes deregulated in these mice and Id2 and Id3, two known negative regulators of B cell differentiation, were found to be upregulated in the EPLM and preB cells of the transgenic mice. Furthermore, the Id2 and Id3 promoters contain octamer-like sites, to which OBF1 can bind. These results provide evidence that tight regulation of OBF1 expression in early B cells is essential to allow efficient B lymphocyte differentiation.

  6. Ups and Downs of Poised RNA Polymerase II in B-Cells.

    Directory of Open Access Journals (Sweden)

    Phuong Dao

    2016-04-01

    Full Text Available Recent genome-wide analyses have uncovered a high accumulation of RNA polymerase II (Pol II at the 5' end of genes. This elevated Pol II presence at promoters, referred to here as Poll II poising, is mainly (but not exclusively attributed to temporal pausing of transcription during early elongation which, in turn, has been proposed to be a regulatory step for processes that need to be activated "on demand". Yet, the full genome-wide regulatory role of Pol II poising is yet to be delineated. To elucidate the role of Pol II poising in B cell activation, we compared Pol II profiles in resting and activated B cells. We found that while Pol II poised genes generally overlap functionally among different B cell states and correspond to the functional groups previously identified for other cell types, non-poised genes are B cell state specific. Focusing on the changes in transcription activity upon B cell activation, we found that the majority of such changes were from poised to non-poised state. The genes showing this type of transition were functionally enriched in translation, RNA processing and mRNA metabolic process. Interestingly, we also observed a transition from non-poised to poised state. Within this set of genes we identified several Immediate Early Genes (IEG, which were highly expressed in resting B cell and shifted from non-poised to poised state after B cell activation. Thus Pol II poising does not only mark genes for rapid expression in the future, but it is also associated with genes that are silenced after a burst of their expression. Finally, we performed comparative analysis of the presence of G4 motifs in the context of poised versus non-poised but active genes. Interestingly we observed a differential enrichment of these motifs upstream versus downstream of TSS depending on poising status. The enrichment of G4 sequence motifs upstream of TSS of non-poised active genes suggests a potential role of quadruplexes in expression

  7. Role of the functional MNS16A VNTR-243 variant of the human telomerase reverse transcriptase gene in progression and response to therapy of patients with non-Hodgkin's B-cell lymphomas.

    Science.gov (United States)

    Wysoczanska, B; Wrobel, T; Dobrzynska, O; Mazur, G; Bogunia-Kubik, K

    2015-04-01

    MNS16A is a functional polymorphic tandem repeat within the human telomerase reverse transcriptase (hTERT) gene. To investigate whether any of the MNS16A repeats represents a genetic risk factor for NHL susceptibility, progression of or response to therapy in 75 patients with non-Hodgkin's lymphomas (NHLs) and 126 healthy individuals were genotyped using the PCR-VNTR technique. A slightly higher frequency of the MNS16A VNTR-243 variant was detected among patients who did not respond to treatment (NR) as compared to patients with complete or partial remission (0.83 vs. 0.51, P = 0.055). NR patients more frequently developed aggressive than indolent type of the disease (0.92 vs. 0.41, P = 0.001). The VNTR-243 allele was more frequently detected among patients with an intermediate-high/high International Prognostic Index (IPI 3-4) score (P = 0.063), especially in patients with advanced age and IPI 3-4 (P = 0.040). In multivariate analysis, higher IPI 3-4 score (OR = 11.364, P = 0.051) and aggressive type of the disease (OR = 18.182, P = 0.012) were found to be independent genetic markers associated with nonresponse to treatment. Presence of the MNS16A VNTR-243 variant also strongly tended to affect the risk of a less favourable response to therapy and was more frequently present among nonresponders (OR = 5.848, P = 0.059). Genetic variation within the hTERT gene may affect the progression and treatment of lymphoproliferative disorders. © 2015 John Wiley & Sons Ltd.

  8. Deacetylase activity of histone deacetylase 3 is required for productiveVDJrecombination and B-cell development.

    Science.gov (United States)

    Stengel, Kristy R; Barnett, Kelly R; Wang, Jing; Liu, Qi; Hodges, Emily; Hiebert, Scott W; Bhaskara, Srividya

    2017-08-08

    Histone deacetylase 3 (HDAC3) is the catalytic component of NCoR/SMRT corepressor complexes that mediate the actions of transcription factors implicated in the regulation of B-cell development and function. We crossed Hdac3 conditional knockout mice with Mb1-Cre knockin animals to delete Hdac3 in early progenitor B cells. The spleens of Hdac3 F/- Mb1-Cre +/- mice were virtually devoid of mature B cells, and B220 + CD43 + B-cell progenitors accumulated within the bone marrow. Quantitative deep sequencing of the Ig heavy chain locus from B220 + CD43 + populations identified a defect in V H DJ H recombination with a severe reduction in productive rearrangements, which directly corresponded to the loss of pre-B cells from Hdac3 Δ /- bone marrow. For Hdac3 Δ /- B cells that did show productive VDJ rearrangement, there was significant skewing toward the incorporation of proximal V H gene segments and a corresponding reduction in distal V H gene segment use. Although transcriptional effects within these loci were modest, Hdac3 Δ /- progenitor cells displayed global changes in chromatin structure that likely hindered effective distal V-DJ recombination. Reintroduction of wild-type Hdac3 restored normal B-cell development, whereas an Hdac3 point mutant lacking deacetylase activity failed to complement this defect. Thus, the deacetylase activity of Hdac3 is required for the generation of mature B cells.

  9. Deacetylase activity of histone deacetylase 3 is required for productive VDJ recombination and B-cell development

    Science.gov (United States)

    Stengel, Kristy R.; Barnett, Kelly R.; Wang, Jing; Liu, Qi; Hodges, Emily; Hiebert, Scott W.; Bhaskara, Srividya

    2017-01-01

    Histone deacetylase 3 (HDAC3) is the catalytic component of NCoR/SMRT corepressor complexes that mediate the actions of transcription factors implicated in the regulation of B-cell development and function. We crossed Hdac3 conditional knockout mice with Mb1-Cre knockin animals to delete Hdac3 in early progenitor B cells. The spleens of Hdac3F/−Mb1-Cre+/− mice were virtually devoid of mature B cells, and B220+CD43+ B-cell progenitors accumulated within the bone marrow. Quantitative deep sequencing of the Ig heavy chain locus from B220+CD43+ populations identified a defect in VHDJH recombination with a severe reduction in productive rearrangements, which directly corresponded to the loss of pre-B cells from Hdac3Δ/− bone marrow. For Hdac3Δ/− B cells that did show productive VDJ rearrangement, there was significant skewing toward the incorporation of proximal VH gene segments and a corresponding reduction in distal VH gene segment use. Although transcriptional effects within these loci were modest, Hdac3Δ/− progenitor cells displayed global changes in chromatin structure that likely hindered effective distal V-DJ recombination. Reintroduction of wild-type Hdac3 restored normal B-cell development, whereas an Hdac3 point mutant lacking deacetylase activity failed to complement this defect. Thus, the deacetylase activity of Hdac3 is required for the generation of mature B cells. PMID:28739911

  10. Intravascular Large B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Maria S. Khan MD, FACP

    2014-03-01

    Full Text Available Case Presentation . A 69-year-old Hispanic male, with a past history of diabetes and coronary disease, was admitted for fever, diarrhea, and confusion of 4 weeks duration. Physical examination showed a disoriented patient with multiple ecchymoses, possible ascites, and bilateral scrotal swelling. Hemoglobin was 6.7, prothrombin time (PT 21.4 seconds with international normalized ratio 2.1, partial thromboplastin time (PTT 55.6 seconds, fibrin split 10 µg/L, and lactate dehydrogenase (LDH 1231 IU/L. Except for a positive DNA test for Epstein–Barr virus (EBV infection, extensive diagnostic workup for infections, malignancy, or a neurological cause was negative. Mixing studies revealed a nonspecific inhibitor of PT and PTT but Factor VIII levels were normal. The patient was empirically treated with antibiotics but developed hypotension and died on day 27 of admission. At autopsy, patient was found to have intravascular diffuse large B-cell lymphoma involving skin, testes, lung, and muscles. The malignant cells were positive for CD20, CD791, Mum-1, and Pax-5 and negative for CD3, CD5, CD10, CD30, and Bcl-6. The malignant cells were 100% positive for Ki-67. Discussion . Intravascular large cell B-cell lymphoma (IVLBCL is rare form of diffuse large B-cell lymphoma and tends to proliferate within small blood vessels, particularly capillaries and postcapillary venules. The cause of its affinity for vascular bed remains unknown. In many reports, IVLBCL was associated with HIV, HHV8, and EBV infections. The fact that our case showed evidence of EBV infection lends support to the association of this diagnosis to viral illness. The available literature on this subject is scant, and in many cases, the diagnosis was made only at autopsy. The typical presentation of this disorder is with B symptoms, progressive neurologic deficits, and skin findings. Bone marrow, spleen, and liver are involved in a minority of patients. Nearly all patients have elevated LDH

  11. The double bromodomain protein Brd2 promotes B cell expansion and mitogenesis.

    Science.gov (United States)

    Belkina, Anna C; Blanton, Wanda P; Nikolajczyk, Barbara S; Denis, Gerald V

    2014-03-01

    Bromodomain-containing transcriptional regulators represent new epigenetic targets in different hematologic malignancies. However, bromodomain-mediated mechanisms that couple histone acetylation to transcription in lymphopoiesis and govern mature lymphocyte mitogenesis are poorly understood. Brd2, a transcriptional coregulator that contains dual bromodomains and an extraterminal domain (the BET family), couples chromatin to cell-cycle progression. We reported previously the first functional characterization of a BET protein as an effector of mammalian mitogenic signal transduction: Eμ-Brd2 Tg mice develop "activated B cell" diffuse large B cell lymphoma. No other animal models exist for genetic or lentiviral expression of BET proteins, hampering testing of novel anti-BET anticancer drugs, such as JQ1. We transduced HSCs with Brd2 lentivirus and reconstituted recipient mice to test the hypothesis that Brd2 regulates hematopoiesis in BM and mitogenesis in the periphery. Forced expression of Brd2 provides an expansion advantage to the donor-derived B cell compartment in BM and increases mature B cell mitogenic responsiveness in vitro. Brd2 binds the cyclin A promoter in B cells, shown by ChIP, and increases cyclin A mRNA and protein levels, and S-phase progression in vitro in mitogen-stimulated primary B cells, but not T cells, reinforcing results from Eμ-Brd2 mice. The small molecule BET inhibitor JQ1 reduces B cell mitogenesis, consistent with the interpretation that BET inhibitors are antiproliferative. Brd2-specific knockdown experiments show that Brd2 is also required for hematopoiesis. We conclude that Brd2 plays a critical, independent role in regulation of mitogenic response genes, particularly cyclin A, in B cells.

  12. The Epstein-Barr virus BamHI C promoter is not essential for B cell immortalization in vitro, but it greatly enhances B cell growth transformation.

    Science.gov (United States)

    Tierney, Rosemary J; Nagra, Jasdeep; Rowe, Martin; Bell, Andrew I; Rickinson, Alan B

    2015-03-01

    Epstein-Barr virus (EBV) infection of B cells leads to the sequential activation of two viral promoters, Wp and Cp, resulting in the expression of six EBV nuclear antigens (EBNAs) and the viral Bcl2 homologue BHRF1. The viral transactivator EBNA2 is required for this switch from Wp to Cp usage during the initial stages of infection. EBNA2-dependent Cp transcription is mediated by the EBNA2 response element (E2RE), a region that contains at least two binding sites for cellular factors; one of these sites, CBF1, interacts with RBP-JK, which then recruits EBNA2 to the transcription initiation complex. Here we demonstrate that the B cell-specific transcription factor BSAP/Pax5 binds to a second site, CBF2, in the E2RE. Deletion of the E2RE in the context of a recombinant virus greatly diminished levels of Cp-initiated transcripts during the initial stages of infection but did not affect the levels of Wp-initiated transcripts or EBNA mRNAs. Consistent with this finding, viruses deleted for the E2RE were not markedly impaired in their ability to induce B cell transformation in vitro. In contrast, a larger deletion of the entire Cp region did reduce EBNA mRNA levels early after infection and subsequently almost completely ablated lymphoblastoid cell line (LCL) outgrowth. Notably, however, rare LCLs could be established following infection with Cp-deleted viruses, and these were indistinguishable from wild-type-derived LCLs in terms of steady-state EBV gene transcription. These data indicate that, unlike Wp, Cp is dispensable for the virus' growth-transforming activity. Epstein-Barr virus (EBV), a B lymphotropic herpesvirus etiologically linked to several B cell malignancies, efficiently induces B cell proliferation leading to the outgrowth of lymphoblastoid cell lines (LCLs). The initial stages of this growth-transforming infection are characterized by the sequential activation of two viral promoters, Wp and Cp, both of which appear to be preferentially active in target B

  13. Corticosteroid modulation of immunoglobulin expression and B-cell function in COPD.

    Science.gov (United States)

    Lee, Jin; Machin, Matthew; Russell, Kirsty E; Pavlidis, Stelios; Zhu, Jie; Barnes, Peter J; Chung, Kian F; Adcock, Ian M; Durham, Andrew L

    2016-05-01

    We investigated changes in gene expression that occur in chronic obstructive pulmonary disease (COPD) after corticosteroid treatment and sought to identify the mechanisms that regulate these changes. Biopsy samples were taken from patients with COPD (Global Initiative for Chronic Obstructive Lung Disease stage I to II) before and after treatment with fluticasone propionate (FP)/salmeterol (SM) (50/500, 4 wk). Gene expression was measured by microarray and was confirmed by real-time reverse transcription-quantitative PCR (RT-qPCR). The effect of FP on IgG expression and B-cell proliferation in the presence of oxidative stress was also studied. FP/SM significantly increased the expression of 180 genes while repressing 343 genes. The top 5 down-regulated genes were associated with immunoglobulin production, whereas the immunomodulatory FK506 binding protein (FK506BP) was up-regulated. Genes including IL6, IL8, and TBET-encoding TBX21 were unaffected. FP reduced IgG protein and mRNA expression and proliferation of human B cells through the dephosphorylation of ERK-1/2 via increased DUSP1 (dual-specificity protein phosphatase 1) expression. Consistent with in vivo data, oxidative stress did not prevent FP-induced suppression of IgG expression in human B cells in vitro Changes in expression were validated by RT-qPCR and by gene set enrichment analysis in distinct COPD cohorts. FP may reduce the adaptive immune response in COPD and may be more effective in patients with an increased B-cell/antibody response indicated by high autoantibody titers.-Lee, J., Machin, M., Russell, K. E., Pavlidis, S., Zhu, J., Barnes, P. J., Chung, K. F., Adcock, I. M., Durham, A. L. Corticosteroid modulation of immunoglobulin expression and B-cell function in COPD. © FASEB.

  14. Trypanosoma brucei Co-opts NK Cells to Kill Splenic B2 B Cells.

    Directory of Open Access Journals (Sweden)

    Deborah Frenkel

    2016-07-01

    Full Text Available After infection with T. brucei AnTat 1.1, C57BL/6 mice lost splenic B2 B cells and lymphoid follicles, developed poor parasite-specific antibody responses, lost weight, became anemic and died with fulminating parasitemia within 35 days. In contrast, infected C57BL/6 mice lacking the cytotoxic granule pore-forming protein perforin (Prf1-/- retained splenic B2 B cells and lymphoid follicles, developed high-titer antibody responses against many trypanosome polypeptides, rapidly suppressed parasitemia and did not develop anemia or lose weight for at least 60 days. Several lines of evidence show that T. brucei infection-induced splenic B cell depletion results from natural killer (NK cell-mediated cytotoxicity: i B2 B cells were depleted from the spleens of infected intact, T cell deficient (TCR-/- and FcγRIIIa deficient (CD16-/- C57BL/6 mice excluding a requirement for T cells, NKT cell, or antibody-dependent cell-mediated cytotoxicity; ii administration of NK1.1 specific IgG2a (mAb PK136 but not irrelevant IgG2a (myeloma M9144 prevented infection-induced B cell depletion consistent with a requirement for NK cells; iii splenic NK cells but not T cells or NKT cells degranulated in infected C57BL/6 mice co-incident with B cell depletion evidenced by increased surface expression of CD107a; iv purified NK cells from naïve C57BL/6 mice killed purified splenic B cells from T. brucei infected but not uninfected mice in vitro indicating acquisition of an NK cell activating phenotype by the post-infection B cells; v adoptively transferred C57BL/6 NK cells prevented infection-induced B cell population growth in infected Prf1-/- mice consistent with in vivo B cell killing; vi degranulated NK cells in infected mice had altered gene and differentiation antigen expression and lost cytotoxic activity consistent with functional exhaustion, but increased in number as infection progressed indicating continued generation. We conclude that NK cells in T. brucei

  15. B cell signature during inactive systemic lupus is heterogeneous: toward a biological dissection of lupus.

    Directory of Open Access Journals (Sweden)

    Jean-Claude Garaud

    Full Text Available Systemic lupus erythematosous (SLE is an autoimmune disease with an important clinical and biological heterogeneity. B lymphocytes appear central to the development of SLE which is characterized by the production of a large variety of autoantibodies and hypergammaglobulinemia. In mice, immature B cells from spontaneous lupus prone animals are able to produce autoantibodies when transferred into immunodeficient mice, strongly suggesting the existence of intrinsic B cell defects during lupus. In order to approach these defects in humans, we compared the peripheral B cell transcriptomas of quiescent lupus patients to normal B cell transcriptomas. When the statistical analysis is performed on the entire group of patients, the differences between patients and controls appear quite weak with only 14 mRNA genes having a false discovery rate ranging between 11 and 17%, with 6 underexpressed genes (PMEPA1, TLR10, TRAF3IP2, LDOC1L, CD1C and EGR1. However, unforced hierarchical clustering of the microarrays reveals a subgroup of lupus patients distinct from both the controls and the other lupus patients. This subgroup has no detectable clinical or immunological phenotypic peculiarity compared to the other patients, but is characterized by 1/an IL-4 signature and 2/the abnormal expression of a large set of genes with an extremely low false discovery rate, mainly pointing to the biological function of the endoplasmic reticulum, and more precisely to genes implicated in the Unfolded Protein Response, suggesting that B cells entered an incomplete BLIMP1 dependent plasmacytic differentiation which was undetectable by immunophenotyping. Thus, this microarray analysis of B cells during quiescent lupus suggests that, despite a similar lupus phenotype, different biological roads can lead to human lupus.

  16. B Cell Receptor-Mediated Internalization of Salmonella: A Novel Pathway for Autonomous B Cell Activation and Antibody Production

    NARCIS (Netherlands)

    Souwer, Yuri; Griekspoor, Alexander; Jorritsma, Tineke; de Wit, Jelle; Janssen, Hans; Neefjes, Jacques; van Ham, S. Marieke

    2009-01-01

    The present paradigm is that primary B cells are nonphagocytosing cells. In this study, we demonstrate that human primary B cells are able to internalize bacteria when the bacteria are recognized by the BCR. BCR-mediated internalization of Salmonella typhimurium results in B cell differentiation and

  17. Improved method for predicting linear B-cell epitopes

    OpenAIRE

    Larsen, Jens Erik Pontoppidan; Lund, Ole; Nielsen, Morten

    2006-01-01

    Background B-cell epitopes are the sites of molecules that are recognized by antibodies of the immune system. Knowledge of B-cell epitopes may be used in the design of vaccines and diagnostics tests. It is therefore of interest to develop improved methods for predicting B-cell epitopes. In this paper, we describe an improved method for predicting linear B-cell epitopes. Results In order to do this, three data sets of linear B-cell epitope annotated proteins were constructed. A data set was co...

  18. Silencing miR-146a influences B cells and ameliorates experimental autoimmune myasthenia gravis.

    Science.gov (United States)

    Zhang, JunMei; Jia, Ge; Liu, Qun; Hu, Jue; Yan, Mei; Yang, BaiFeng; Yang, Huan; Zhou, WenBin; Li, Jing

    2015-01-01

    MicroRNAs have been shown to be important regulators of immune homeostasis as patients with aberrant microRNA expression appeared to be more susceptible to autoimmune diseases. We recently found that miR-146a was up-regulated in activated B cells in response to rat acetylcholine receptor (AChR) α-subunit 97-116 peptide, and this up-regulation was significantly attenuated by AntagomiR-146a. Our data also demonstrated that silencing miR-146a with its inhibitor AntagomiR-146a effectively ameliorated clinical myasthenic symptoms in mice with ongoing experimental autoimmune myasthenia gravis. Furthermore, multiple defects were observed after miR-146a was knocked down in B cells, including decreased anti-R97-116 antibody production and class switching, reduced numbers of plasma cells, memory B cells and B-1 cells, and weakened activation of B cells. Previously, miR-146a has been identified as a nuclear factor-κB-dependent gene and predicted to base pair with the tumour necrosis factor receptor-associated factor 6 (TRAF6) and interleukin-1 receptor-associated kinase 1 (IRAK1) genes to regulate the immune response. However, our study proved that miR-146a inhibition had no effect on the expression of TRAF6 and IRAK1 in B cells. This result suggests that the function of miR-146a in B cells does not involve these two target molecules. We conclude that silencing miR-146a exerts its therapeutic effects by influencing the B-cell functions that contribute to the autoimmune pathogenesis of myasthenia gravis. © 2014 John Wiley & Sons Ltd.

  19. Interferon-alpha triggers B cell effector 1 (Be1 commitment.

    Directory of Open Access Journals (Sweden)

    Marie-Ghislaine de Goër de Herve

    Full Text Available B-cells can contribute to the pathogenesis of autoimmune diseases not only through auto-antibody secretion but also via cytokine production. Therapeutic depletion of B-cells influences the functions and maintenance of various T-cell subsets. The mechanisms governing the functional heterogeneity of B-cell subsets as cytokine-producing cells are poorly understood. B-cells can differentiate into two functionally polarized effectors, one (B-effector-1-cells producing a Th-1-like cytokine pattern and the other (Be2 producing a Th-2-like pattern. IL-12 and IFN-γ play a key role in Be1 polarization, but the initial trigger of Be1 commitment is unclear. Type-I-interferons are produced early in the immune response and prime several processes involved in innate and adaptive responses. Here, we report that IFN-α triggers a signaling cascade in resting human naive B-cells, involving STAT4 and T-bet, two key IFN-γ gene imprinting factors. IFN-α primed naive B-cells for IFN-γ production and increased IFN-γ gene responsiveness to IL-12. IFN-γ continues this polarization by re-inducing T-bet and up-regulating IL-12Rβ2 expression. IFN-α and IFN-γ therefore pave the way for the action of IL-12. These results point to a coordinated action of IFN-α, IFN-γ and IL-12 in Be1 polarization of naive B-cells, and may provide new insights into the mechanisms by which type-I-interferons favor autoimmunity.

  20. The regulatory roles of B cell subsets in transplantation.

    Science.gov (United States)

    Chu, Zhulang; Zou, Weilong; Xu, Yanan; Sun, Qiquan; Zhao, Yong

    2018-02-01

    B cells mediate allograft rejection through antigen presentation, and production of cytokines and antibodies. More and more immunosuppressive agents specifically targeting B cells and plasma cells have been applied in clinical transplantation. However, recent studies have indicated the regulatory roles of B cells. Therefore, it is vital to clarify the different effects of B cell subsets in organ transplantation so that we can completely understand the diverse functions of B cells in transplantation. Areas covered: This review focuses on the regulatory roles of B cells in transplantation. B cell subsets with immune modulation and factors mediating immunosuppressive functions of regulatory B (Breg) cells were analyzed. Therapies targeting B cells and the application of B cells for transplant tolerance induction were discussed. Expert commentary: Besides involving rejection, B cells could also play regulatory roles in transplantation. Breg cells and the related markers may be used to predict the immune tolerant state in transplant recipients. New therapeutic strategies targeting B cells should be explored to promote tolerance induction with less impact on the host's protective immunity in organ transplanted patients.

  1. TET2 mutations in B cells of patients affected by angioimmunoblastic T-cell lymphoma.

    Science.gov (United States)

    Schwartz, Friederike H; Cai, Qian; Fellmann, Eva; Hartmann, Sylvia; Mäyränpää, Mikko I; Karjalainen-Lindsberg, Marja-Liisa; Sundström, Christer; Scholtysik, René; Hansmann, Martin-Leo; Küppers, Ralf

    2017-06-01

    Angioimmunoblastic T-cell lymphomas (AITLs) frequently carry mutations in the TET2 and IDH2 genes. TET2 mutations represent early genetic lesions as they had already been detected in haematopoietic precursor cells of AITL patients. We show by analysis of whole-tissue sections and microdissected PD1 + cells that the frequency of TET2-mutated AITL is presumably even higher than reported (12/13 cases in our collection; 92%). In two-thirds of informative AITLs (6/9), a fraction of B cells was also TET2-mutated. Investigation of four AITLs by TET2 and IGHV gene sequencing of single microdissected B cells showed that between 10% and 60% of polyclonal B cells in AITL lymph nodes harboured the identical TET2 mutations of the respective T-cell lymphoma clone. Thus, TET2-mutated haematopoietic precursor cells in AITL patients not only give rise to the T-cell lymphoma but also generate a large population of mutated mature B cells. Future studies will show whether this is a reason why AITL patients frequently also develop B-cell lymphomas. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  2. Data Bank 1B - Ticket Dollar Value Origin and Destination - Public Version : second quarter.

    Science.gov (United States)

    2012-01-01

    This CD presents the same data as Data Bank 1B and also includes dual codes for the operating and ticketed carrier and incorporates data as reported each quarter by participating air carriers from the continuous 10% sample of airline tickets. It incl...

  3. Data Bank 1B - Ticket Dollar Value Origin and Destination - Public Version : fourth quarter.

    Science.gov (United States)

    2010-01-01

    This CD presents the same data as Data Bank 1B and also includes dual codes for the operating and ticketed carrier and incorporates data as reported each quarter by participating air carriers from the continuous 10% sample of airline tickets. It incl...

  4. Data Bank 1B - Ticket Dollar Value Origin and Destination - Public Version : first quarter.

    Science.gov (United States)

    2014-01-01

    This CD presents the same data as Data Bank 1B and also includes dual codes for the operating and ticketed carrier and incorporates data as reported each quarter by participating air carriers from the continuous 10% sample of airline tickets. It incl...

  5. Data Bank 1B - Ticket Dollar Value Origin and Destination - Public Version : third quarter.

    Science.gov (United States)

    2010-01-01

    This CD presents the same data as Data Bank 1B and also includes dual codes for the operating and ticketed carrier and incorporates data as reported each quarter by participating air carriers from the continuous 10% sample of airline tickets. It incl...

  6. Copanlisib and Nivolumab in Treating Participants With Recurrent or Refractory Diffuse Large B-cell Lymphoma or Primary Mediastinal Large B-cell Lymphoma

    Science.gov (United States)

    2018-03-29

    Diffuse Large B-Cell Lymphoma; Mediastinal (Thymic) Large B-Cell Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma

  7. Early events associated with infection of Epstein-Barr virus infection of primary B-cells.

    Directory of Open Access Journals (Sweden)

    Sabyasachi Halder

    2009-09-01

    Full Text Available Epstein Barr virus (EBV is closely associated with the development of a vast number of human cancers. To develop a system for monitoring early cellular and viral events associated with EBV infection a self-recombining BAC containing 172-kb of the Epstein Barr virus genome BAC-EBV designated as MD1 BAC (Chen et al., 2005, J.Virology was used to introduce an expression cassette of green fluorescent protein (GFP by homologous recombination, and the resultant BAC clone, BAC-GFP-EBV was transfected into the HEK 293T epithelial cell line. The resulting recombinant GFP EBV was induced to produce progeny virus by chemical inducer from the stable HEK 293T BAC GFP EBV cell line and the virus was used to immortalize human primary B-cell as monitored by green fluorescence and outgrowth of the primary B cells. The infection, B-cell activation and cell proliferation due to GFP EBV was monitored by the expression of the B-cell surface antigens CD5, CD10, CD19, CD23, CD39, CD40 , CD44 and the intercellular proliferation marker Ki-67 using Flow cytometry. The results show a dramatic increase in Ki-67 which continues to increase by 6-7 days post-infection. Likewise, CD40 signals showed a gradual increase, whereas CD23 signals were increased by 6-12 hours, maximally by 3 days and then decreased. Monitoring the viral gene expression pattern showed an early burst of lytic gene expression. This up-regulation of lytic gene expression prior to latent genes during early infection strongly suggests that EBV infects primary B-cell with an initial burst of lytic gene expression and the resulting progeny virus is competent for infecting new primary B-cells. This process may be critical for establishment of latency prior to cellular transformation. The newly infected primary B-cells can be further analyzed for investigating B cell activation due to EBV infection.

  8. Silenced B-Cell Receptor Response To Autoantigen In A Poor-Prognostic Subset Of Chronic Lymphocytic Leukemia

    DEFF Research Database (Denmark)

    Bergh, Ann-Charlotte; Evaldsson, Chamilly; Pedersen, Lone Bredo

    2014-01-01

    Chronic lymphocytic leukemia B cells express auto/xeno antigen-reactive antibodies that bind to self-epitopes and resemble natural IgM antibodies in their repertoire. One of the antigenic structures recognized is oxidation-induced malonedialdehyde that is present on low-density lipoprotein......, apoptotic blebs, and on certain microbes. The poor-prognostic stereotyped subset #1 (Clan I IGHV genes-IGKV1(D)-39) express IgM B-cell receptors that bind oxidized low-density lipoprotein. In this study, we have used for the first time this authentic cognate antigen for analysis of downstream B......-cell receptor-signal transduction events, since it is more faithful to B-cell physiology than anti-IgM. Multivalent oxidized low-density lipoprotein showed specific binding to subset #1 IgM/IgD B-cell receptors, whereas native low-density lipoprotein did not. The antigen binding induced prompt receptor...

  9. Antigen receptors and somatic hypermutation in B-cell chronic lymphocytic leukemia with Richter's transformation

    NARCIS (Netherlands)

    Smit, Laura A.; van Maldegem, Febe; Langerak, Anton W.; van der Schoot, C. Ellen; de Wit, Mireille J.; Bea, Silvia; Campo, Elias; Bende, Richard J.; van Noesel, Carel J. M.

    2006-01-01

    BACKGROUND AND OBJECTIVES: Activation-induced cytidine deaminase is essential for somatic hypermutation and class switch recombination of the immunoglobulin genes in B cells. It has been proposed that aberrant targeting of the somatic hypermutation machinery is instrumental in initiation and

  10. A recurrent germline PAX5 mutation confers susceptibility to pre-B cell acute lymphoblastic leukemia

    NARCIS (Netherlands)

    Shah, S.; Schrader, K.A.; Waanders, E.; Timms, A.E.; Vijai, J.; Miething, C.; Wechsler, J.; Yang, J.; Hayes, J.; Klein, R.J.; Zhang, J.; Wei, L.; Wu, G.; Rusch, M.; Nagahawatte, P.; Ma, J; Chen, S.C.; Song, G.; Cheng, J.; Meyers, P.; Bhojwani, D.; Jhanwar, S.; Maslak, P.; Fleisher, M.; Littman, J.; Offit, L.; Rau-Murthy, R.; Fleischut, M.H.; Corines, M.; Murali, R.; Gao, X.; Manschreck, C.; Kitzing, T.; Murty, V.V.; Raimondi, S.C.; Kuiper, R.P.; Simons, A.; Schiffman, J.D.; Onel, K.; Plon, S.E.; Wheeler, D.A.; Ritter, D.; Ziegler, D.S.; Tucker, K.; Sutton, R.; Chenevix-Trench, G.; Li, J.; Huntsman, D.G.; Hansford, S.; Senz, J.; Walsh, T.; Lee (Helen Dowling Instituut), M. van der; Hahn, C.N.; Roberts, K.G.; King, M.C.; Lo, S.M.; Levine, R.L.; Viale, A.; Socci, N.D.; Nathanson, K.L.; Scott, H.S.; Daly, M.; Lipkin, S.M.; Lowe, S.W.; Downing, J.R.; Altshuler, D.; Sandlund, J.T.; Horwitz, M.S.; Mullighan, C.G.; Offit, K.

    2013-01-01

    Somatic alterations of the lymphoid transcription factor gene PAX5 (also known as BSAP) are a hallmark of B cell precursor acute lymphoblastic leukemia (B-ALL), but inherited mutations of PAX5 have not previously been described. Here we report a new heterozygous germline variant, c.547G>A

  11. Polyclonal B-cell lymphocytosis with binucleated lymphocytes (PPBL

    Directory of Open Access Journals (Sweden)

    Xavier Troussard

    2008-10-01

    Full Text Available Xavier Troussard1, Edouard Cornet1, Jean-François Lesesve2, Carine Kourel3, Hossein Mossafa31Laboratoire d’Hématologie Côte de Nacre, Université Caen Basse Normandie Caen, Registre Régional des Hémopathies Malignes de Basse Normandie, France; 2Laboratoire d’Hématologie, Vandoeuvre-Les-Nancy Cedex, France; 3Département de Génétique Humaine, Laboratoire pasteur-Cerba, Cergy-Pontoise, FranceFor the Groupe Français d’Hématologie cellulaire (GFHCAbstract: Persistent polyclonal B-cell lymphocytosis (PPBL is a rare and recently described entity. The review of the literature show PPBL is diagnosed predominantly but not exclusively in women, usually smokers. PPBL is recognized by a moderate, chronic and absolute lymphocytosis (>4 × 109/l in the peripheral blood. In 10% of cases without lymphocytosis, the PPBL diagnosis has to be suggested by peripheral blood examination showing in all cases atypical binucleated lymphocytes. A polyclonal serum IgM is also associated and HLA-DR7 expression is present in most cases. Contrary to B-cell chronic lymphoproliferative disorders (B-CLPD, peripheral B cells are polyclonal with kappa and lambda light-chain expression and no clonal rearrangement of immunoglobulin heavy chain genes is usually demonstrated. The detection of an extra isochromosome for the long arm of chromosome 3 +i(3(q10 has to be considered as a specific marker of PPBL. We performed conventional cytogenetic analysis (CCA in 111 patients with typical PPBL we followed-up more than 4 years. +i(3q was detected in 34% (33/98, PCC in 8% (8/98 and both abnormalities in 31% (30/98. CCA showed neither +i(3q nor PCC in 28% (27/98. Fluorescence in situ hybridization (FISH was also performed in 84 cases and +i(3q was detected in 71% (60/84. When combining both procedures in 84 patients, +i(3q was detected in 17 patients with negative CCA and was confirmed in 43 patients with positive CCA. CCA and FISH were both negative in 24 cases. Whether

  12. Eμ/miR-125b transgenic mice develop lethal B-cell malignancies.

    Science.gov (United States)

    Enomoto, Y; Kitaura, J; Hatakeyama, K; Watanuki, J; Akasaka, T; Kato, N; Shimanuki, M; Nishimura, K; Takahashi, M; Taniwaki, M; Haferlach, C; Siebert, R; Dyer, M J S; Asou, N; Aburatani, H; Nakakuma, H; Kitamura, T; Sonoki, T

    2011-12-01

    MicroRNA-125b-1 (miR-125b-1) is a target of a chromosomal translocation t(11;14)(q24;q32) recurrently found in human B-cell precursor acute lymphoblastic leukemia (BCP-ALL). This translocation results in overexpression of miR-125b controlled by immunoglobulin heavy chain gene (IGH) regulatory elements. In addition, we found that six out of twenty-one BCP-ALL patients without t(11;14)(q24;q32) showed overexpression of miR-125b. Interestingly, four out of nine patients with BCR/ABL-positive BCP-ALL and one patient with B-cell lymphoid crisis that had progressed from chronic myelogenous leukemia overexpressed miR-125b. To examine the role of the deregulated expression of miR-125b in the development of B-cell tumor in vivo, we generated transgenic mice mimicking the t(11;14)(q24;q32) (Eμ/miR-125b-TG mice). Eμ/miR-125b-TG mice overexpressed miR-125b driven by IGH enhancer and promoter and developed IgM-negative or IgM-positive lethal B-cell malignancies with clonal proliferation. B cells obtained from the Eμ/miR-125b-TG mice were resistant to apoptosis induced by serum starvation. We identified Trp53inp1, a pro-apoptotic gene induced by cell stress, as a novel target gene of miR-125b in hematopoietic cells in vitro and in vivo. Our results provide direct evidence that miR-125b has important roles in the tumorigenesis of precursor B cells.

  13. Primary cardiac diffuse large B-cell lymphoma with activated B-cell-like phenotype

    Directory of Open Access Journals (Sweden)

    Vijaya Gadage

    2011-01-01

    Full Text Available Primary cardiac lymphoma (PCL is a rare and fatal disorder. It may often mimic other common cardiac tumors like cardiac myxoma because of similarities in the clinical presentation. We report a case of PCL of diffuse large B-cell type, in a 38-year-old, immunocompetent male who presented with superior vena cava syndrome that was excised as a myxoma. Histology revealed a large cell population diffusely and strongly expressing CD45, CD20, MUM1/IRF4 and FOXP1 hinting at an activated B-cell (ABC-like phenotype. After four cycles of Rituximab with CHOP (cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone the tumor regressed completely but the patient had a relapse and subsequently succumbed to the disease confirming the aggressive nature. The aggressive behavior of PCL may be possibly linked to its ABC-like origin.

  14. Continuous signaling of CD79b and CD19 is required for the fitness of Burkitt lymphoma B cells.

    Science.gov (United States)

    He, Xiaocui; Kläsener, Kathrin; Iype, Joseena M; Becker, Martin; Maity, Palash C; Cavallari, Marco; Nielsen, Peter J; Yang, Jianying; Reth, Michael

    2018-04-18

    Expression of the B-cell antigen receptor (BCR) is essential not only for the development but also for the maintenance of mature B cells. Similarly, many B-cell lymphomas, including Burkitt lymphoma (BL), require continuous BCR signaling for their tumor growth. This growth is driven by immunoreceptor tyrosine-based activation motif (ITAM) and PI3 kinase (PI3K) signaling. Here, we employ CRISPR/Cas9 to delete BCR and B-cell co-receptor genes in the human BL cell line Ramos. We find that Ramos B cells require the expression of the BCR signaling component Igβ (CD79b), and the co-receptor CD19, for their fitness and competitive growth in culture. Furthermore, we show that in the absence of any other BCR component, Igβ can be expressed on the B-cell surface, where it is found in close proximity to CD19 and signals in an ITAM-dependent manner. These data suggest that Igβ and CD19 are part of an alternative B-cell signaling module that use continuous ITAM/PI3K signaling to promote the survival of B lymphoma and normal B cells. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

  15. Transcription factor Ebf1 regulates differentiation stage-specific signaling, proliferation, and survival of B cells

    OpenAIRE

    Györy, Ildiko; Boller, Sören; Nechanitzky, Robert; Mandel, Elizabeth; Pott, Sebastian; Liu, Edison; Grosschedl, Rudolf

    2012-01-01

    The transcription factor Ebf1 regulates early B lymphopoiesis by acting in a network with E2A and Pax5. However, the function of Ebf1 at later stages of differentiation in unclear. In this study, Grosschedl and colleagues investigate the role of Ebf1 in B lymphopoiesis by using conditional gene inactivation. The authors show that Ebf1 is required for proliferation and survival of pro-B and mature B cells. In addition, the proliferation defect of Ebf1fl/fl pro-B cells can be overcome by transf...

  16. Loss of PRDM1/BLIMP-1 function contributes to poor prognosis of activated B-cell-like diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Xia, Yi; Xu-Monette, Z Y; Tzankov, A

    2017-01-01

    was effectively evaluated for PRDM1/BLIMP-1 deletion, mutation, and protein expression. BLIMP-1 expression was frequently associated with the ABC phenotype and plasmablastic morphologic subtype of DLBCL, yet 63% of the ABC-DLBCL patients were negative for BLIMP-1 protein expression. In these patients, loss...... with ABC-DLBCL but not in those with germinal center B-cell-like DLBCL (GCB-DLBCL). Gene expression profiling revealed that loss of PRDM1/BLIMP-1 expression correlated with a decreased plasma-cell differentiation signature and upregulation of genes involved in B-cell receptor signaling and tumor......-cell proliferation. In conclusion, these results provide novel clinical and biological insight into the tumor-suppressive role of PRDM1/BLIMP-1 in ABC-DLBCL patients and suggest that loss of PRDM1/BLIMP-1 function contributes to the overall poor prognosis of ABC-DLBCL patients....

  17. Adipose Tissue Inflammation Induces B Cell Inflammation and Decreases B Cell Function in Aging

    Directory of Open Access Journals (Sweden)

    Daniela Frasca

    2017-08-01

    Full Text Available Aging is the greatest risk factor for developing chronic diseases. Inflamm-aging, the age-related increase in low-grade chronic inflammation, may be a common link in age-related diseases. This review summarizes recent published data on potential cellular and molecular mechanisms of the age-related increase in inflammation, and how these contribute to decreased humoral immune responses in aged mice and humans. Briefly, we cover how aging and related inflammation decrease antibody responses in mice and humans, and how obesity contributes to the mechanisms for aging through increased inflammation. We also report data in the literature showing adipose tissue infiltration with immune cells and how these cells are recruited and contribute to local and systemic inflammation. We show that several types of immune cells infiltrate the adipose tissue and these include macrophages, neutrophils, NK cells, innate lymphoid cells, eosinophils, T cells, B1, and B2 cells. Our main focus is how the adipose tissue affects immune responses, in particular B cell responses and antibody production. The role of leptin in generating inflammation and decreased B cell responses is also discussed. We report data published by us and by other groups showing that the adipose tissue generates pro-inflammatory B cell subsets which induce pro-inflammatory T cells, promote insulin resistance, and secrete pathogenic autoimmune antibodies.

  18. Human B cells fail to secrete type I interferons upon cytoplasmic DNA exposure.

    Science.gov (United States)

    Gram, Anna M; Sun, Chenglong; Landman, Sanne L; Oosenbrug, Timo; Koppejan, Hester J; Kwakkenbos, Mark J; Hoeben, Rob C; Paludan, Søren R; Ressing, Maaike E

    2017-11-01

    Most cells are believed to be capable of producing type I interferons (IFN I) as part of an innate immune response against, for instance, viral infections. In macrophages, IFN I is potently induced upon cytoplasmic exposure to foreign nucleic acids. Infection of these cells with herpesviruses leads to triggering of the DNA sensors interferon-inducible protein 16 (IFI16) and cyclic GMP-AMP (cGAMP) synthase (cGAS). Thereby, the stimulator of interferon genes (STING) and the downstream molecules TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) are sequentially activated culminating in IFN I secretion. Human gamma-herpesviruses, such as Epstein-Barr virus (EBV), exploit B cells as a reservoir for persistent infection. In this study, we investigated whether human B cells, similar to macrophages, engage the cytoplasmic DNA sensing pathway to induce an innate immune response. We found that the B cells fail to secrete IFN I upon cytoplasmic DNA exposure, although they express the DNA sensors cGAS and IFI16 and the signaling components TBK1 and IRF3. In primary human B lymphocytes and EBV-negative B cell lines, this deficiency is explained by a lack of detectable levels of the central adaptor protein STING. In contrast, EBV-transformed B cell lines did express STING, yet both these lines as well as STING-reconstituted EBV-negative B cells did not produce IFN I upon dsDNA or cGAMP stimulation. Our combined data show that the cytoplasmic DNA sensing pathway is dysfunctional in human B cells. This exemplifies that certain cell types cannot induce IFN I in response to cytoplasmic DNA exposure providing a potential niche for viral persistence. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. In Silico Prediction Analysis of Idiotope-Driven T–B Cell Collaboration in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Rune A. Høglund

    2017-10-01

    Full Text Available Memory B cells acting as antigen-presenting cells are believed to be important in multiple sclerosis (MS, but the antigen they present remains unknown. We hypothesized that B cells may activate CD4+ T cells in the central nervous system of MS patients by presenting idiotopes from their own immunoglobulin variable regions on human leukocyte antigen (HLA class II molecules. Here, we use bioinformatics prediction analysis of B cell immunoglobulin variable regions from 11 MS patients and 6 controls with other inflammatory neurological disorders (OINDs, to assess whether the prerequisites for such idiotope-driven T–B cell collaboration are present. Our findings indicate that idiotopes from the complementarity determining region (CDR 3 of MS patients on average have high predicted affinities for disease associated HLA-DRB1*15:01 molecules and are predicted to be endosomally processed by cathepsin S and L in positions that allows such HLA binding to occur. Additionally, complementarity determining region 3 sequences from cerebrospinal fluid (CSF B cells from MS patients contain on average more rare T cell-exposed motifs that could potentially escape tolerance and stimulate CD4+ T cells than CSF B cells from OIND patients. Many of these features were associated with preferential use of the IGHV4 gene family by CSF B cells from MS patients. This is the first study to combine high-throughput sequencing of patient immune repertoires with large-scale prediction analysis and provides key indicators for future in vitro and in vivo analyses.

  20. Lunatic, Manic and Radical Fringe Each Promote T and B Cell Development

    Science.gov (United States)

    Song, Yinghui; Kumar, Vivek; Wei, Hua-Xing; Qiu, Ju; Stanley, Pamela

    2015-01-01

    Lunatic, Manic and Radical Fringe (LFNG, MFNG and RFNG) are N-acetylglucosaminyltransferases that modify Notch receptors and regulate Notch signaling. Loss of LFNG affects thymic T cell development and LFNG and MFNG are required for marginal zone (MZ) B cell development. However, roles for MFNG and RFNG in T cell development, RFNG in B cell development, or Fringes in T and B cell activation, are not identified. Here we show that Lfng/Mfng/Rfng triple knockout (Fng tKO) mice exhibited reduced binding of DLL4 Notch ligand to CD4/CD8 double-negative (DN) T cell progenitors, and reduced expression of NOTCH1 targets Deltex1 and CD25. Fng tKO mice had reduced frequencies of DN1/cKit+ and DN2 T cell progenitors and CD4+CD8+ double positive (DP) T cell precursors, but increased frequencies of CD4+ and CD8+ single positive (SP) T cells in thymus. In spleen, Fng tKO mice had reduced frequencies of CD4+, CD8+, central memory T cells and marginal zone (MZ) B cells, and an increased frequency of effector memory T cells, neutrophils, follicular (Fo) and MZ P B cells. The Fng tKO phenotype was cell-autonomous and largely rescued in mice expressing one allele of a single Fng gene. Stimulation of Fng tKO splenocytes with anti-CD3/CD28 beads or lipopolysaccharide gave reduced proliferation compared to controls, and the generation of activated T cells by concanavalin A or L-PHA was also reduced in Fng tKO mice. Therefore, each Fringe contributes to T and B cell development, and Fringe is required for optimal in vitro stimulation of T and B cells. PMID:26608918

  1. Differences in the composition of the human antibody repertoire by B cell subsets in the blood

    Directory of Open Access Journals (Sweden)

    Eva Szymanska eMroczek

    2014-03-01

    Full Text Available The vast initial diversity of the antibody repertoire is generated centrally by means of a complex series of V (D J gene rearrangement events, variation in the site of gene segment joining, and TdT catalyzed N- region addition. Although the diversity is great, close inspection has revealed distinct and unique characteristics in the antibody repertoires expressed by different B cell developmental subsets. In order to illustrate our approach to repertoire analysis, we present an in-depth comparison of V (D J gene usage, hydrophobicity, length, DH reading frame, and amino acid usage between heavy chain repertoires expressed by immature, transitional, mature, memory IgD+, memory IgD-, and plasmacytes isolated from the blood of a single individual. Our results support the view that in both human and mouse the H chain repertoires expressed by individual, developmental B cell subsets appear to differ in sequence content. Sequencing of unsorted B cells from the blood is thus likely to yield an incomplete or compressed view of what is actually happening in the immune response of the individual. Our findings support the view that studies designed to correlate repertoire expression with diseases of immune function will likely require deep sequencing of B cells sorted by subset.

  2. Brucella abortus-infected B cells induce osteoclastogenesis.

    Science.gov (United States)

    Pesce Viglietti, Ayelén Ivana; Arriola Benitez, Paula Constanza; Giambartolomei, Guillermo Hernán; Delpino, María Victoria

    2016-09-01

    Brucella abortus is an intracellular bacterium that establishes lifelong infections in livestock and humans although the mechanisms of its chronicity are poorly understood. Activated B cells have long lifespan and B. abortus infection activates B cells. Our results indicate that the direct infection of B cells with B. abortus induced matrix metalloproteinase-9 (MMP-9), receptor activator for NF κB ligand (RANKL), tumor necrosis factor (TNF)-α and interleukin (IL)-6 secretion. In addition, supernatants from B. abortus-infected B cells induced bone marrow-derived monocytes to undergo osteoclastogenesis. Using osteoprotegerin, RANKL's decoy receptor, we determined that RANKL is involved in osteoclastogenesis induced by supernatants from B. abortus-infected B cells. The results presented here shed light on how the interactions of B. abortus with B cells may have a role in the pathogenesis of brucellar osteoarticular disease. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  3. Transcriptional control of pre-B cell development and leukemia prevention.

    Science.gov (United States)

    Pang, Swee Heng Milon; Carotta, Sebastian; Nutt, Stephen L

    2014-01-01

    The differentiation of early B cell progenitors is controlled by multiple transcriptional regulators and growth-factor receptors. The triad of DNA-binding proteins, E2A, EBF1, and PAX5 is critical for both the early specification and commitment of B cell progenitors, while a larger number of secondary determinants, such as members of the Ikaros, ETS, Runx, and IRF families have more direct roles in promoting stage-specific pre-B gene-expression program. Importantly, it is now apparent that mutations in many of these transcription factors are associated with the progression to acute lymphoblastic leukemia. In this review, we focus on recent studies that have shed light on the transcriptional hierarchy that controls efficient B cell commitment and differentiation as well as focus on the oncogenic consequences of the loss of many of the same factors.

  4. [Primary mediastinal large B-cell lymphoma: a clinicopathologic study of 27 cases].

    Science.gov (United States)

    Shi, Q Y; Feng, X; Chen, H; Ma, H H; Lu, Z F; Shi, Q L; Zhou, X J; Shen, Q

    2017-09-08

    Objective: To study the clinicopathologic characteristics and diagnostic criteria of primary mediastinal B-cell lymphoma (PMBL), and to distinguish PMBL from classic Hodgkin lymphoma(CHL) and systemic diffuse large B-cell lymphoma(DLBCL). Methods: The clinical features, histologic findings, results of immunohistochemical study and prgnosis in 27 PMBL cases were analyzed, with review of literature. Results: The age of patients ranged from 19 to 82 years (median age 34 years). All cases were located in the mediastinum and frequently accompanied by superior vein cava syndrome. Histologically, the tumor cells were pleomorphic and diffusely distributed. Clear cytoplasm and spindle tumor cells were seen in some cases. Varying amount of sclerosing stroma with collagen deposition was seen.Immunohistochemical study showed that the tumor cells were positive for CD20(100%, 27/27), CD30 (64.0%, 16/25), CD23 (77.3%, 17/22) and p63 (16/19). Clonal B cell gene rearrangement was seen. Conclusions: PMBL is a subtype of diffuse large B-cell lymphoma with various histomorphology. Immunohistochemistry can help to confirm the diagnosis, and the prognosis is better than diffuse large B cell lymphoma, not otherwise specified.

  5. Anti-B cell antibody therapies for inflammatory rheumatic diseases

    DEFF Research Database (Denmark)

    Faurschou, Mikkel; Jayne, David R W

    2014-01-01

    Several monoclonal antibodies targeting B cells have been tested as therapeutics for inflammatory rheumatic diseases. We review important observations from randomized clinical trials regarding the efficacy and safety of anti-B cell antibody-based therapies for rheumatoid arthritis, systemic lupus...... and functions in rheumatic disorders. Future studies should also evaluate how to maintain disease control by means of conventional and/or biologic immunosuppressants after remission-induction with anti-B cell antibodies....

  6. Immunoglobulin gene alterations in normal and neoplastic B cells

    NARCIS (Netherlands)

    van Maldegem, F.

    2009-01-01

    The production of high affinity antibodies is crucial in the combat of pathogenic invaders. Somatic hypermutation and class switch recombination are two DNA modifying processes that take place in the lymph node germinal centres, in order to increase antibody affinity and determine its effector

  7. Circulating clonotypic B cells in multiple myeloma and monoclonal gammopathy of undetermined significance.

    Science.gov (United States)

    Thiago, Leandro S; Perez-Andres, Martin; Balanzategui, Ana; Sarasquete, Maria E; Paiva, Bruno; Jara-Acevedo, Maria; Barcena, Paloma; Sanchez, Maria Luz; Almeida, Julia; González, Marcos; San Miguel, Jesus F; Garcia-Sanz, Ramón; Orfao, Alberto

    2014-01-01

    The B-cell compartment in which multiple myeloma stem cells reside remains unclear. We investigated the potential presence of mature, surface-membrane immunoglobulin-positive B lymphocytes clonally related to the tumor bone marrow plasma cells among different subsets of peripheral blood B cells from ten patients (7 with multiple myeloma and 3 with monoclonal gammopathies of undetermined significance). The presence of clonotypic immunoglobulin heavy chain gene rearrangements was determined in multiple highly-purified fractions of peripheral blood B-lymphocytes including surface-membrane IgM(+) CD27(-) naïve B-lymphocytes, plus surface-membrane IgG(+), IgA(+) and IgM(+) memory CD27(+) B cells, and normal circulating plasma cells, in addition to (mono)clonal plasma cells, by a highly-specific and sensitive allele-specific oligonucleotide polymerase chain reaction directed to the CDR3 sequence of the rearranged IGH gene of tumor plasma cells from individual patients. Our results showed systematic absence of clonotypic rearrangements in all the different B-cell subsets analyzed, including M-component isotype-matched memory B-lymphocytes, at frequencies <0.03 cells/μL (range: 0.0003-0.08 cells/μL); the only exception were the myeloma plasma cells detected and purified from the peripheral blood of four of the seven myeloma patients. These results indicate that circulating B cells from patients with multiple myeloma and monoclonal gammopathies of undetermined significance are usually devoid of clonotypic B cells while the presence of immunophenotypically aberrant myeloma plasma cells in peripheral blood of myeloma patients is a relatively frequent finding.

  8. B cells in multiple sclerosis therapy-A comprehensive review.

    Science.gov (United States)

    Rahmanzadeh, R; Weber, M S; Brück, W; Navardi, S; Sahraian, M A

    2018-03-07

    For decades, B cells were ignored in multiple sclerosis (MS) pathogenesis, and the disease was always regarded as a T cell-mediated disorder. Recent evidence shows that there is an antigen-driven B-cell response in the central nervous system of patients with MS, and memory B cells/plasma cells are detectable in MS lesions. The striking efficacy of B cell-depleting therapies in reducing the inflammatory activity of the disease highlights that B cells may play more pathogenetic roles than expected. B cells express several unique characteristic markers on their surface, for example, CD19, CD20 molecules, that provide selective targets for monoclonal antibodies. In this respect, several B cell-targeted therapies emerged, including anti-CD20 antibodies (rituximab, ocrelizumab, and ofatumumab), anti-CD19 antibody (inebilizumab), and agents targeting the BAFF/APRIL signaling pathway (atacicept, belimumab, and LY2127399). In this review, we discuss, in detail, the immunobiology of B cells and their protective and destructive roles in MS pathogenesis. In the second part, we list the completed and ongoing clinical trials investigating the safety and efficacy of B cell-related monoclonal antibodies in MS. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Regulatory T cells and B cells: implication on autoimmune diseases

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

    The regulatory T (Treg) cells play an important role in the maintenance of homeostasis and the prevention of autoimmune diseases. Although most studies are focusing on the role of Treg cells in T cells and T cells-mediated diseases, these cells also directly affect B cells and other non-T cells. This manuscript updates the role of Treg cells on the B cells and B cell-mediated diseases. In addition, the mechanisms whereby Treg cells suppress B cell responses have been discussed.

  10. Atypical B cell receptor signaling: straddling immune diseases and cancer.

    Science.gov (United States)

    Faris, Mary

    2013-08-01

    The B-cell receptor (BCR) signaling pathway plays an essential role in the survival, proliferation, differentiation and trafficking of lymphocytic. Recent findings associate aberrant BCR signaling with specific disease pathologies, including B-cell malignancies and autoimmune disorders. Inhibition of the BCR signaling pathway may therefore provide promising new strategies for the treatment of B-cell diseases. This special issue of International Reviews of Immunology focuses on atypical B-cell receptor signaling, its role in immune diseases and cancer, and its implications for potential therapeutic intervention.

  11. Logical analysis of diffuse large B-cell lymphomas.

    Science.gov (United States)

    Alexe, G; Alexe, S; Axelrod, D E; Hammer, P L; Weissmann, D

    2005-07-01

    The goal of this study is to re-examine the oligonucleotide microarray dataset of Shipp et al., which contains the intensity levels of 6817 genes of 58 patients with diffuse large B-cell lymphoma (DLBCL) and 19 with follicular lymphoma (FL), by means of the combinatorics, optimisation, and logic-based methodology of logical analysis of data (LAD). The motivations for this new analysis included the previously demonstrated capabilities of LAD and its expected potential (1) to identify different informative genes than those discovered by conventional statistical methods, (2) to identify combinations of gene expression levels capable of characterizing different types of lymphoma, and (3) to assemble collections of such combinations that if considered jointly are capable of accurately distinguishing different types of lymphoma. The central concept of LAD is a pattern or combinatorial biomarker, a concept that resembles a rule as used in decision tree methods. LAD is able to exhaustively generate the collection of all those patterns which satisfy certain quality constraints, through a systematic combinatorial process guided by clear optimization criteria. Then, based on a set covering approach, LAD aggregates the collection of patterns into classification models. In addition, LAD is able to use the information provided by large collections of patterns in order to extract subsets of variables, which collectively are able to distinguish between different types of disease. For the differential diagnosis of DLBCL versus FL, a model based on eight significant genes is constructed and shown to have a sensitivity of 94.7% and a specificity of 100% on the test set. For the prognosis of good versus poor outcome among the DLBCL patients, a model is constructed on another set consisting also of eight significant genes, and shown to have a sensitivity of 87.5% and a specificity of 90% on the test set. The genes selected by LAD also work well as a basis for other kinds of statistical

  12. Fingolimod induces BAFF and expands circulating transitional B cells without activating memory B cells and plasma cells in multiple sclerosis.

    Science.gov (United States)

    Miyazaki, Yusei; Niino, Masaaki; Takahashi, Eri; Suzuki, Masako; Mizuno, Masanori; Hisahara, Shin; Fukazawa, Toshiyuki; Amino, Itaru; Nakano, Fumihito; Nakamura, Masakazu; Akimoto, Sachiko; Minami, Naoya; Fujiki, Naoto; Doi, Shizuki; Shimohama, Shun; Terayama, Yasuo; Kikuchi, Seiji

    2018-02-01

    Patients with multiple sclerosis (MS) who are treated with fingolimod have an increased proportion of transitional B cells in the circulation, but the underlying mechanism is not known. We hypothesized that B cell-activating factor of the tumor necrosis factor family (BAFF) is involved in the process. Compared with healthy controls and untreated MS patients, fingolimod-treated MS patients had significantly higher serum concentrations of BAFF, which positively correlated with the proportions and the absolute numbers of transitional B cells in blood. Despite the elevated concentrations of BAFF in fingolimod-treated MS patients, serum levels of soluble transmembrane activator and calcium-modulating cyclophilin ligand interactor, and B cell maturation antigen were not elevated. Our results show that fingolimod induces BAFF in the circulation and expands transitional B cells, but does not activate memory B cells or plasma cells in MS, which is favorable for the treatment of this disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Clonal heterogeneity of thymic B cells from early-onset myasthenia gravis patients with antibodies against the acetylcholine receptor.

    Science.gov (United States)

    Vrolix, Kathleen; Fraussen, Judith; Losen, Mario; Stevens, Jo; Lazaridis, Konstantinos; Molenaar, Peter C; Somers, Veerle; Bracho, Maria Alma; Le Panse, Rozen; Stinissen, Piet; Berrih-Aknin, Sonia; Maessen, Jos G; Van Garsse, Leen; Buurman, Wim A; Tzartos, Socrates J; De Baets, Marc H; Martinez-Martinez, Pilar

    2014-08-01

    Myasthenia gravis (MG) with antibodies against the acetylcholine receptor (AChR-MG) is considered as a prototypic autoimmune disease. The thymus is important in the pathophysiology of the disease since thymus hyperplasia is a characteristic of early-onset AChR-MG and patients often improve after thymectomy. We hypothesized that thymic B cell and antibody repertoires of AChR-MG patients differ intrinsically from those of control individuals. Using immortalization with Epstein-Barr Virus and Toll-like receptor 9 activation, we isolated and characterized monoclonal B cell lines from 5 MG patients and 8 controls. Only 2 of 570 immortalized B cell clones from MG patients produced antibodies against the AChR (both clones were from the same patient), suggesting that AChR-specific B cells are not enriched in the thymus. Surprisingly, many B cell lines from both AChR-MG and control thymus samples displayed reactivity against striated muscle proteins. Striational antibodies were produced by 15% of B cell clones from AChR-MG versus 6% in control thymus. The IgVH gene sequence analysis showed remarkable similarities, concerning VH family gene distribution, mutation frequency and CDR3 composition, between B cells of AChR-MG patients and controls. MG patients showed clear evidence of clonal B cell expansion in contrast to controls. In this latter aspect, MG resembles multiple sclerosis and clinically isolated syndrome, but differs from systemic lupus erythematosus. Our results support an antigen driven immune response in the MG thymus, but the paucity of AChR-specific B cells, in combination with the observed polyclonal expansions suggest a more diverse immune response than expected. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. B-cell-mediated strategies to fight chronic allograft rejection

    Directory of Open Access Journals (Sweden)

    Ali H Dalloul

    2013-12-01

    Full Text Available Solid organs have been transplanted for decades. Since the improvement in graft selection and in medical and surgical procedures, the likelihood of graft function after one year is now close to 90%. Nonetheless even well-matched recipients continue to need medications for the rest of their lives hence adverse side effects and enhanced morbidity. Understanding Immune rejection mechanisms, is of increasing importance since the greater use of living-unrelated donors and genetically unmatched individuals. Chronic rejection is devoted to T-cells, however the role of B-cells in rejection has been appreciated recently by the observation that B-cell depletion improve graft survival. By contrast however, B-cells can be beneficial to the grafted tissue. This protective effect is secondary to either the secretion of protective antibodies or the induction of B-cells that restrain excessive inflammatory responses, chiefly by local provision of IL-10, or inhibit effector T-cells by direct cellular interactions. As a proof of concept B-cell-mediated infectious transplantation tolerance could be achieved in animal models, and evidence emerged that the presence of such B-cells in transplanted patients correlate with a favorable outcome. Among these populations, regulatory B-cells constitute a recently described population. These cells may develop as a feedback mechanism to prevent uncontrolled reactivity to antigens and inflammatory stimuli. The difficult task for the clinician, is to quantify the respective ratios and functions of tolerant vs effector B-cells within a transplanted organ, at a given time point in order to modulate B-cell-directed therapy. Several receptors at the B-cell membrane as well as signaling molecules, can now be targeted for this purpose. Understanding the temporal expansion of regulatory B-cells in grafted patients and the stimuli that activate them will help in the future to implement specific strategies aimed at fighting chronic

  15. How B cells influence bone biology in health and disease.

    Science.gov (United States)

    Horowitz, Mark C; Fretz, Jackie A; Lorenzo, Joseph A

    2010-09-01

    It is now well established that important regulatory interactions occur between the cells in the hematopoietic, immune and skeletal systems (osteoimmunology). B lymphocytes (B cells) are responsible for the generation and production of antibodies or immunoglobulins in the body. Together with T cells these lymphocytes comprise the adaptive immune system, which allows an individual to develop specific responses to an infection and retain memory of that infection, allowing for a faster and more robust response if that same infection occurs again. In addition to this immune function, B cells have a close and multifaceted relationship with bone cells. B cells differentiate from hematopoietic stem cells (HSCs) in supportive niches found on endosteal bone surfaces. Cells in the osteoblast lineage support HSC and B cell differentiation in these niches. B cell differentiation is regulated, at least in part, by a series of transcription factors that function in a temporal manner. While these transcription factors are required for B cell differentiation, their loss causes profound changes in the bone phenotype. This is due, in part, to the close relationship between macrophage/osteoclast and B cell differentiation. Cross talk between B cells and bone cells is reciprocal with defects in the RANKL-RANK, OPG signaling axis resulting in altered bone phenotypes. While the role of B cells during normal bone remodeling appears minimal, activated B cells play an important role in many inflammatory diseases with associated bony changes. This review examines the relationship between B cells and bone cells and how that relationship affects the skeleton and hematopoiesis during health and disease. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Mixed Lichenoid and Follicular T- and B-Cell Lymphoid Reaction to Red Tattoos With Monoclonal T Cells.

    Science.gov (United States)

    Zaaroura, Hiba; Bergman, Reuven

    2017-09-28

    Pseudolymphomatous reactions have been described to occur in tattoos. Most cases have exhibited T-cell predominance and polyclonal T-cell receptor gene rearrangements. One case with monoclonal IgH gene rearrangements progressed into B-cell lymphoma. Lichenoid infiltrates are commonly described but lymphoid follicles much less frequently. We report a case with mixed lichenoid and follicular T- and B-cell reaction to red tattoos. The histopathology and the immunohistochemical studies were constant with a mixed T- and B-cell pseudolymphoma, the IgH gene rearrangement study was polyclonal, but the T-cell receptor gene rearrangement study was monoclonal. The patient who responded to intralesional corticosteroid injections remains under close scrutiny.

  17. The shape of the lymphocyte receptor repertoire: lessons from the B cell receptor

    Directory of Open Access Journals (Sweden)

    Katherine J. L. Jackson

    2013-09-01

    Full Text Available Both the B cell receptor (BCR and the T cell receptor (TCR repertoires are generated through essentially identical processes of V(DJ recombination, exonuclease trimming of germline genes and the random addition of non-template encoded nucleotides. The naïve TCR repertoire is constrained by thymic selection, and TCR repertoire studies have therefore focused strongly on the diversity of MHC-binding CDR3. The process of somatic point mutations has given B cell studies a major focus on variable (IGHV, IGLV and IGKV genes. This in turn has influenced how both the naïve and memory BCR repertoires have been studied. Diversity (D genes are also more easily identified in BCR VDJ rearrangements than in TCR VDJ rearrangements, and this has allowed the processes and elements that contribute to the incredible diversity of the immunoglobulin heavy chain CDR3 to be analyzed in detail. This diversity can be contrasted with that of the light chain where a small number of polypeptide sequences dominate the repertoire. Biases in the use of different germline genes, in gene processing and in the addition of non-template encoded nucleotides appear to be intrinsic to the recombination process, imparting ‘shape’ to the repertoire of rearranged genes as a result of differences spanning many orders of magnitude in the probabilities that different BCRs will be generated. This may function to increase the precursor frequency of naïve B cells with important specificities, and the likely emergence of such B cell lineages upon antigen exposure is discussed with reference to public and private T cell clonotypes.

  18. JSI-124 inhibits IgE production in an IgE B cell line.

    Science.gov (United States)

    Cui, Lulu; Bi, Jiacheng; Yan, Dehong; Ye, Xiufeng; Zheng, Mingxing; Yu, Guang; Wan, Xiaochun

    2017-01-29

    IgE is a key effector molecule in atopic diseases; however, the regulation mechanisms of IgE production in IgE B cells remain poorly understood. In the present study, we demonstrate that JSI-124 (cucurbitacin I), a selective STAT3 inhibitor, selectively inhibits production of IgE by a human IgE B cell line, CRL-8033 cells, while does not affect the IgG production by IgG B cell lines. In the aspect of molecular mechanism, we found that Igλ, but not Ighe, gene expression was suppressed by JSI-124. The above effects of JSI-124 were not mediated by affecting cellular proliferation or apoptosis. Furthermore, multiple B cell differentiation-related genes expression was not significantly affected by JSI-124. Taken together, we demonstrate a potential strategy of therapeutically suppressing IgE production without affecting IgG production in atopic patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Bidirectional regulation between B cells and T cells

    NARCIS (Netherlands)

    Margry, B.

    2014-01-01

    B cells were often thought of as simple precursors of end-stage effector cells that are merely in charge of antibody production. Research in the last decades has shown that B cells possess important other roles as well, including their involvement in the regulation and functioning of T cell-mediated

  20. DNA breaks early in replication in B cell cancers

    Science.gov (United States)

    Research by scientists at the NCI has identified a new class of DNA sites in cells that break early in the replication process. They found that these break sites correlate with damage often seen in B cell cancers, such as diffuse large B cell lymphoma.

  1. A fine romance: T follicular helper cells and B cells.

    Science.gov (United States)

    King, Cecile

    2011-06-24

    T follicular helper (Tfh) cells help B cells to generate affinity-matured antibodies. Three papers in this issue of Immunity (Choi et al., 2011; Kerfoot et al., 2011; Kitano et al., 2011) provide information about the reciprocal relationship between B cells and Tfh cells. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Resource Competition Determines Selection of B Cell Repertoires

    NARCIS (Netherlands)

    Boer, R.J. de; Freitas, A.A. (António); Perelson, A.S. (Alan)

    2001-01-01

    Previous experiments with mouse chimeras demonstrated that cellular competition for antigen- specific survival signals plays a crucial role in the maintenance of the naive B cell repertoire. Transgenic (Tg) B cell populations in these chimeras have a shortened lifespan and poor competitive

  3. Comparison of EBV DNA viral load in whole blood, plasma, B-cells and B-cell culture supernatant.

    Science.gov (United States)

    Ouedraogo, David Eric; Bollore, Karine; Viljoen, Johannes; Foulongne, Vincent; Reynes, Jacques; Cartron, Guillaume; Vendrell, Jean-Pierre; Van de Perre, Philippe; Tuaillon, Edouard

    2014-05-01

    Epstein-Barr virus (EBV) genome quantitation in whole blood is used widely for therapeutic monitoring of EBV-associated disorders in immunosuppressed individuals and in patients with EBV-associated lymphoma. However, the most appropriate biological material to be used for EBV DNA quantitation remains a subject of debate. This study compare the detection rate and levels of EBV DNA from whole blood, plasma, enriched B-cells, and B-cell short-term culture supernatant using quantitative real-time PCR. Samples were collected from 33 subjects with either HIV infection or B-cell lymphoma. Overall, EBV DNA was detected in 100% of enriched B-cell samples, in 82% of B-cell culture supernatants, in 57% of plasma, and 42% of whole blood samples. A significant correlation for EBV viral load was found between enriched B-cell and B-cell culture supernatant material (ρ = 0.92; P < 0.0001), but no significant correlation existed between EBV DNA levels in whole blood and enriched B-cells (ρ = -0.02; P = 0.89), whole blood and plasma (ρ = 0.24; P = 0.24), or enriched B-cells and plasma (ρ = 0.08; P = 0.77). Testing of enriched B-cells appeared to be the most sensitive method for detection of EBV DNA as well as for exploration of the cellular reservoir. Quantitation of EBV DNA in plasma and B-cell culture supernatant may be of interest to assess EBV reactivation dynamics and response to treatment as well as to decipher EBV host-pathogen interactions in various clinical scenarios. © 2013 Wiley Periodicals, Inc.

  4. Precursor B Cells Increase in the Lung during Airway Allergic Inflammation: A Role for B Cell-Activating Factor.

    Directory of Open Access Journals (Sweden)

    Konstantinos Samitas

    Full Text Available B cells, key cells in allergic inflammation, differentiate in the bone marrow and their precursors include pro-B, pre-B and immature B cells. Eosinophil progenitor cells increase in the lung after allergen exposure. However, the existence and possible role of B cell precursors in the lung during allergic inflammation remains elusive.A BALB/c mouse model of allergic airway inflammation was utilized to perform phenotypic and quantification analyses of pro-B and pre-B cells in the lung by flow cytometry. B cell maturation factors IL-7 and B cell-activating factor (BAFF and their receptors (CD127 and BAFFR, BCMA, TACI, respectively were also evaluated in the lung and serum. The effect of anti-BAFF treatment was investigated both in vivo (i.p. administration of BAFF-R-Ig fusion protein and in vitro (colony forming cell assay. Finally, BAFF levels were examined in the bronchoalveolar lavage (BAL of asthmatic patients and healthy controls.Precursor pro and pre-B cells increase in the lung after allergen exposure, proliferate in the lung tissue in vivo, express markers of chemotaxis (CCR10 and CXCR4 and co-stimulation (CD40, CD86 and are resistant to apoptosis (Bax. Precursor B cells express receptors for BAFF at baseline, while after allergen challenge both their ligand BAFF and the BCMA receptor expression increases in B cell precursors. Blocking BAFFR in the lung in vivo decreases eosinophils and proliferating precursor B cells. Blocking BAFFR in bone marrow cultures in vitro reduces pre-B colony formation units. BAFF is increased in the BAL of severe asthmatics.Our data support the concept of a BAFF-mediated role for B cell precursors in allergic airway inflammation.

  5. Instructive role of the transcription factor E2A in early B lymphopoiesis and germinal center B cell development.

    Science.gov (United States)

    Kwon, Kyongrim; Hutter, Caroline; Sun, Qiong; Bilic, Ivan; Cobaleda, César; Malin, Stephen; Busslinger, Meinrad

    2008-06-01

    The transcription factor E2A controls the initiation of B lymphopoiesis, which is arrested at the pre-pro-B cell stage in E2A-deficient mice. Here, we demonstrate by conditional mutagenesis that E2A is essential for the development of pro-B, pre-B, and immature B cells in the bone marrow. E2A is, however, dispensable for the generation of mature B cells and plasma cells in peripheral lymphoid organs. In contrast, germinal center B cell development is impaired in the absence of E2A despite normal AID expression and class-switch recombination. Molecular analysis revealed that E2A is required not only for initiating but also for maintaining the expression of Ebf1, Pax5, and the B cell gene program in pro-B cells. Notably, precocious Pax5 transcription from the Ikzf1 locus promotes pro-B cell development in E2A-deficient mice, demonstrating that ectopic Pax5 expression is sufficient to activate the B lymphoid transcription program in vivo in the absence of E2A.

  6. Rac-mediated Stimulation of Phospholipase Cγ2 Amplifies B Cell Receptor-induced Calcium Signaling*♦

    Science.gov (United States)

    Walliser, Claudia; Tron, Kyrylo; Clauss, Karen; Gutman, Orit; Kobitski, Andrei Yu.; Retlich, Michael; Schade, Anja; Röcker, Carlheinz; Henis, Yoav I.; Nienhaus, G. Ulrich; Gierschik, Peter

    2015-01-01

    The Rho GTPase Rac is crucially involved in controlling multiple B cell functions, including those regulated by the B cell receptor (BCR) through increased cytosolic Ca2+. The underlying molecular mechanisms and their relevance to the functions of intact B cells have thus far remained unknown. We have previously shown that the activity of phospholipase Cγ2 (PLCγ2), a key constituent of the BCR signalosome, is stimulated by activated Rac through direct protein-protein interaction. Here, we use a Rac-resistant mutant of PLCγ2 to functionally reconstitute cultured PLCγ2-deficient DT40 B cells and to examine the effects of the Rac-PLCγ2 interaction on BCR-mediated changes of intracellular Ca2+ and regulation of Ca2+-regulated and nuclear-factor-of-activated-T-cell-regulated gene transcription at the level of single, intact B cells. The results show that the functional Rac-PLCγ2 interaction causes marked increases in the following: (i) sensitivity of B cells to BCR ligation; (ii) BCR-mediated Ca2+ release from intracellular stores; (iii) Ca2+ entry from the extracellular compartment; and (iv) nuclear translocation of the Ca2+-regulated nuclear factor of activated T cells. Hence, Rac-mediated stimulation of PLCγ2 activity serves to amplify B cell receptor-induced Ca2+ signaling. PMID:25903139

  7. Insights into the Molecular Pathogenesis of Activated B-Cell-like Diffuse Large B-Cell Lymphoma and Its Therapeutic Implications

    International Nuclear Information System (INIS)

    Lenz, Georg

    2015-01-01

    Within the last couple of years, the understanding of the molecular mechanisms that drive the pathogenesis of diffuse large B-cell lymphoma (DLBCL) has significantly improved. Large-scale gene expression profiling studies have led to the discovery of several molecularly defined subtypes that are characterized by specific oncogene addictions and significant differences in their outcome. Next generation sequencing efforts combined with RNA interference screens frequently identify crucial oncogenes that lead to constitutive activation of various signaling pathways that drive lymphomagenesis. This review summarizes our current understanding of the molecular pathogenesis of the activated B-cell-like (ABC) DLBCL subtype that is characterized by poor prognosis. A special emphasis is put on findings that might impact therapeutic strategies of affected patients

  8. Severe B cell deficiency and disrupted splenic architecture in transgenic mice expressing the E41K mutated form of Bruton's tyrosine kinase

    NARCIS (Netherlands)

    Dingjan, GM; Maas, A; Nawijn, MC; Smit, Linda; Voerman, JSA; Grosveld, F; Hendriks, RW

    1998-01-01

    To identify B-cell signaling pathways activated by Bruton's tyrosine kinase (Btk) in vivo, we generated transgenic mice in which Btk expression is driven by the MHC class II Ea gene locus control region. Btk overexpression did not have significant adverse effects on B cell function, and essentially

  9. Marginal zone B-cells, a gatekeeper of innate immunity

    Directory of Open Access Journals (Sweden)

    Moncef eZOUALI

    2011-12-01

    Full Text Available To maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. B-lymphocytes were initially thought to only play a role in the adaptative branch of immunity. However, a number of converging observations revealed that two B-cell subsets, marginal zone (MZ and B1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. In addition to their capacity to mount local antibody response against type 2 T-independent (TI-2 antigens, MZ B-cells can participate to T-dependent (TD immune response through the capture and import of blood-borne antigens to follicular areas of the spleen. Here, we discuss the multiple roles of MZ B-cells in rodents and primates. We also summarize studies —performed in transgenic mice expressing fully human antibodies on their B-cells and macaques whose infection with Simian Immunodeficiency Virus (SIV represents a suitable model for HIV-1 infection in humans— showing that infectious agents have developed strategies to subvert MZ B-cell functions. In these two experimental models, we observed that two microbial superantigens for B-cells (protein A from Staphylococcus aureus and protein L from Peptostreptococcus magnus as well as inactivated AT-2 virions of HIV-1 and infectious SIV preferentially deplete innate-like B-cells —MZ B-cells and/or B1 B-cells— with different consequences on TI and TD antibody responses. These data revealed that viruses and bacteria have developed strategies to deplete innate-like B-cells during the acute phase of infection and to impair the antibody response. Unraveling the intimate mechanisms responsible for targeting MZ B-cells in humans will be important for understanding disease pathogenesis and for designing novel vaccine strategies.

  10. B-cell memory and primary immune deficiencies: interleukin-21 related defects.

    Science.gov (United States)

    Desjardins, Marylin; Mazer, Bruce D

    2013-12-01

    The purpose of this study is to describe recent advances in our understanding of the role of interleukin-21 (IL-21) in B-cell maturation, and how defects in IL-21 receptor (IL-21R) signalling pathways (IL-21R/γc/JAK3/STAT3) are related to primary immune deficiencies. Abnormal signalling through IL-21R/γc/JAK3/STAT3 pathway has been related to decreased specific antibody responses following vaccination, and to increased susceptibility to encapsulated bacterial infections. This is manifested in the hyper-IgE syndrome, X-linked and JAK3-related severe combined immunodeficiency (SCID) and loss-of-function mutations in the IL-21R gene. Common variable immunodeficiency is associated with impaired in-vitro development of peripheral blood mononuclear cells or purified B-cells into memory or CD38 B-cells following addition of IL-21. IL-21 is a key cytokine in development of B-cells into immunoglobulin-secreting cells. Abnormal signalling through the IL-21R/γc/JAK3/STAT3 pathway leads to defective humoral immune responses to both T-dependent and T-independent antigens and impairs the establishment of long-lasting B-cell memory. Studies involving patients with hyper-IgE syndrome demonstrated the nonredundant role of STAT3 in B-cell production of high-affinity specific antibodies, while total serum immunoglobulins could be maintained through STAT3-independent activation of AID (activation-induced cytidine-deaminase). IL-21 related defects may also be associated with reduced natural killer (NK)-cell cytotoxicity and TH17 cytokine production, indicating that abnormalities in the IL-21-IL-21R pathway have profound effects on crucial immune responses.

  11. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking

    Directory of Open Access Journals (Sweden)

    Rocio Flores-Fernández

    2016-01-01

    Full Text Available Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE. In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease.

  12. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking

    Science.gov (United States)

    Flores-Fernández, Rocio; Blanco-Favela, Francisco; Fuentes-Pananá, Ezequiel M.; Chávez-Sánchez, Luis; Gorocica-Rosete, Patricia; Pizaña-Venegas, Alberto; Chávez-Rueda, Adriana Karina

    2016-01-01

    Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE). In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR) as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease. PMID:27314053

  13. MEF2C and EBF1 Co-regulate B Cell-Specific Transcription.

    Science.gov (United States)

    Kong, Nikki R; Davis, Matthew; Chai, Li; Winoto, Astar; Tjian, Robert

    2016-02-01

    Hematopoietic stem cells are capable of self-renewal or differentiation along three main lineages: myeloid, erythroid, and lymphoid. One of the earliest lineage decisions for blood progenitor cells is whether to adopt the lymphoid or myeloid fate. Previous work had shown that myocyte enhancer factor 2C (MEF2C) is indispensable for the lymphoid fate decision, yet the specific mechanism of action remained unclear. Here, we have identified early B cell factor-1 (EBF1) as a co-regulator of gene expression with MEF2C. A genome-wide survey of MEF2C and EBF1 binding sites identified a subset of B cell-specific genes that they target. We also determined that the p38 MAPK pathway activates MEF2C to drive B cell differentiation. Mef2c knockout mice showed reduced B lymphoid-specific gene expression as well as increased myeloid gene expression, consistent with MEF2C's role as a lineage fate regulator. This is further supported by interaction between MEF2C and the histone deacetylase, HDAC7, revealing a likely mechanism to repress the myeloid transcription program. This study thus elucidates both activation and repression mechanisms, identifies regulatory partners, and downstream targets by which MEF2C regulates lymphoid-specific differentiation.

  14. MEF2C and EBF1 Co-regulate B Cell-Specific Transcription.

    Directory of Open Access Journals (Sweden)

    Nikki R Kong

    2016-02-01

    Full Text Available Hematopoietic stem cells are capable of self-renewal or differentiation along three main lineages: myeloid, erythroid, and lymphoid. One of the earliest lineage decisions for blood progenitor cells is whether to adopt the lymphoid or myeloid fate. Previous work had shown that myocyte enhancer factor 2C (MEF2C is indispensable for the lymphoid fate decision, yet the specific mechanism of action remained unclear. Here, we have identified early B cell factor-1 (EBF1 as a co-regulator of gene expression with MEF2C. A genome-wide survey of MEF2C and EBF1 binding sites identified a subset of B cell-specific genes that they target. We also determined that the p38 MAPK pathway activates MEF2C to drive B cell differentiation. Mef2c knockout mice showed reduced B lymphoid-specific gene expression as well as increased myeloid gene expression, consistent with MEF2C's role as a lineage fate regulator. This is further supported by interaction between MEF2C and the histone deacetylase, HDAC7, revealing a likely mechanism to repress the myeloid transcription program. This study thus elucidates both activation and repression mechanisms, identifies regulatory partners, and downstream targets by which MEF2C regulates lymphoid-specific differentiation.

  15. Genomic Profiling of Adult and Pediatric B-cell Acute Lymphoblastic Leukemia.

    Science.gov (United States)

    Liu, Yuan-Fang; Wang, Bai-Yan; Zhang, Wei-Na; Huang, Jin-Yan; Li, Ben-Shang; Zhang, Ming; Jiang, Lu; Li, Jian-Feng; Wang, Ming-Jie; Dai, Yu-Jun; Zhang, Zi-Guan; Wang, Qiang; Kong, Jie; Chen, Bing; Zhu, Yong-Mei; Weng, Xiang-Qin; Shen, Zhi-Xiang; Li, Jun-Min; Wang, Jin; Yan, Xiao-Jing; Li, Yan; Liang, Ying-Min; Liu, Li; Chen, Xie-Qun; Zhang, Wang-Gang; Yan, Jin-Song; Hu, Jian-Da; Shen, Shu-Hong; Chen, Jing; Gu, Long-Jun; Pei, Deqing; Li, Yongjin; Wu, Gang; Zhou, Xin; Ren, Rui-Bao; Cheng, Cheng; Yang, Jun J; Wang, Kan-Kan; Wang, Sheng-Yue; Zhang, Jinghui; Mi, Jian-Qing; Pui, Ching-Hon; Tang, Jing-Yan; Chen, Zhu; Chen, Sai-Juan

    2016-06-01

    Genomic landscapes of 92 adult and 111 pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL) were investigated using next-generation sequencing and copy number alteration analysis. Recurrent gene mutations and fusions were tested in an additional 87 adult and 93 pediatric patients. Among the 29 newly identified in-frame gene fusions, those involving MEF2D and ZNF384 were clinically relevant and were demonstrated to perturb B-cell differentiation, with EP300-ZNF384 inducing leukemia in mice. Eight gene expression subgroups associated with characteristic genetic abnormalities were identified, including leukemia with MEF2D and ZNF384 fusions in two distinct clusters. In subgroup G4 which was characterized by ERG deletion, DUX4-IGH fusion was detected in most cases. This comprehensive dataset allowed us to compare the features of molecular pathogenesis between adult and pediatric B-ALL and to identify signatures possibly related to the inferior outcome of adults to that of children. We found that, besides the known discrepancies in frequencies of prognostic markers, adult patients had more cooperative mutations and greater enrichment for alterations of epigenetic modifiers and genes linked to B-cell development, suggesting difference in the target cells of transformation between adult and pediatric patients and may explain in part the disparity in their responses to treatment. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Genomic Profiling of Adult and Pediatric B-cell Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Yuan-Fang Liu

    2016-06-01

    Full Text Available Genomic landscapes of 92 adult and 111 pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL were investigated using next-generation sequencing and copy number alteration analysis. Recurrent gene mutations and fusions were tested in an additional 87 adult and 93 pediatric patients. Among the 29 newly identified in-frame gene fusions, those involving MEF2D and ZNF384 were clinically relevant and were demonstrated to perturb B-cell differentiation, with EP300-ZNF384 inducing leukemia in mice. Eight gene expression subgroups associated with characteristic genetic abnormalities were identified, including leukemia with MEF2D and ZNF384 fusions in two distinct clusters. In subgroup G4 which was characterized by ERG deletion, DUX4-IGH fusion was detected in most cases. This comprehensive dataset allowed us to compare the features of molecular pathogenesis between adult and pediatric B-ALL and to identify signatures possibly related to the inferior outcome of adults to that of children. We found that, besides the known discrepancies in frequencies of prognostic markers, adult patients had more cooperative mutations and greater enrichment for alterations of epigenetic modifiers and genes linked to B-cell development, suggesting difference in the target cells of transformation between adult and pediatric patients and may explain in part the disparity in their responses to treatment.

  17. Transcription factor miz-1 is required to regulate interleukin-7 receptor signaling at early commitment stages of B cell differentiation.

    Science.gov (United States)

    Kosan, Christian; Saba, Ingrid; Godmann, Maren; Herold, Stefanie; Herkert, Barbara; Eilers, Martin; Möröy, Tarik

    2010-12-14

    B cell development requires the coordinated action of transcription factors and cytokines, in particular interleukin-7 (IL-7). We report that mice lacking the POZ (Poxvirus and zinc finger) domain of the transcription factor Miz-1 (Zbtb17(ΔPOZ/ΔPOZ)) almost entirely lacked follicular B cells, as shown by the fact that their progenitors failed to activate the Jak-Stat5 pathway and to upregulate the antiapoptotic gene Bcl2 upon IL-7 stimulation. We show that Miz-1 exerted a dual role in the interleukin-7 receptor (IL-7R) pathway by directly repressing the Janus kinase (Jak) inhibitor suppressor of cytokine signaling 1 (Socs1) and by activating Bcl2 expression. Zbtb17(ΔPOZ/ΔPOZ) (Miz-1-deficient) B cell progenitors had low expression of early B cell genes as transcription factor 3 (Tcf3) and early B cell factor 1 (Ebf1) and showed a propensity for apoptosis. Only the combined re-expression of Bcl2 and Ebf1 could reconstitute the ability of Miz-1-deficient precursors to develop into CD19(+) B cells.

  18. Regulation of B cell differentiation by intracellular membrane associated proteins and microRNAs: role in the antibody response

    Directory of Open Access Journals (Sweden)

    Zheng eLou

    2015-10-01

    Full Text Available B cells are central to adaptive immunity and their functions in antibody responses are exquisitely regulated. As suggested by recent findings, B cell differentiation is mediated by intracellular membrane structures (including endosomes, lysosomes and autophagosomes and protein factors specifically associated with these membranes, including Rab7, Atg5 and Atg7. These factors participate in vesicle formation/trafficking, signal transduction and induction of gene expression to promote antigen presentation, CSR/SHM, and generation/maintenance of plasma cells and memory B cells. Their expression is induced in B cells activated to differentiate and further fine-tuned by immune-modulating microRNAs, which coordinates CSR/SHM, plasma cell differentiation and memory B cell differentiation. These short non-coding RNAs would individually target multiple factors associated with the same intracellular membrane compartments and collaboratively target a single factor in addition to regulate AID and Blimp-1. These, together with regulation of microRNA biogenesis and activities by endosomes and autophagosomes, show that intracellular membranes and microRNAs, two broadly relevant cell constituents, play important roles in balancing gene expression to specify B cell differentiation processes for optimal antibody responses.

  19. Gallium arsenide exposure impairs splenic B cell accessory function.

    Science.gov (United States)

    Gondre-Lewis, Timothy A; Hartmann, Constance B; Caffrey, Rebecca E; McCoy, Kathleen L

    2003-03-01

    Gallium arsenide (GaAs) is utilized in industries for its semiconductor and optical properties. Chemical exposure of animals systemically suppresses several immune functions. The ability of splenic B cells to activate antigen-specific helper CD4(+) T cell hybridomas was assessed, and various aspects of antigen-presenting cell function were examined. GaAs-exposed murine B cells were impaired in processing intact soluble protein antigens, and the defect was antigen dependent. In contrast, B cells after exposure competently presented peptides to the T cells, which do not require processing. Cell surface expression of major histocompatibility complex (MHC) class II molecules and several costimulatory molecules on splenic B cells, which are critical for helper T cell activation, was not affected by chemical exposure. GaAs exposure also did not influence the stability of MHC class II heterodimers, suggesting that the defect may precede peptide exchange. GaAs-exposed B cells contained a normal level of aspartyl cathepsin activity; however, proteolytic activities of thiol cathepsins B and L were approximately half the control levels. Furthermore, two cleavage fragments of invariant chain, a molecular chaperone of MHC class II molecules, were increased in GaAs-exposed B cells, indicative of defective degradation. Thus, diminished thiol proteolytic activity in B cells may be responsible for their impaired antigen processing and invariant chain degradation, which may contribute to systemic immunosuppression caused by GaAs exposure.

  20. Perivascular Adipose Tissue Harbors Atheroprotective IgM-Producing B Cells

    Directory of Open Access Journals (Sweden)

    Prasad Srikakulapu

    2017-09-01

    Full Text Available Adipose tissue surrounding major arteries (Perivascular adipose tissue or PVAT has long been thought to exist to provide vessel support and insulation. Emerging evidence suggests that PVAT regulates artery physiology and pathology, such as, promoting atherosclerosis development through local production of inflammatory cytokines. Yet the immune subtypes in PVAT that regulate inflammation are poorly characterized. B cells have emerged as important immune cells in the regulation of visceral adipose tissue inflammation and atherosclerosis. B cell-mediated effects on atherosclerosis are subset-dependent with B-1 cells attenuating and B-2 cells aggravating atherosclerosis. While mechanisms whereby B-2 cells aggravate atherosclerosis are less clear, production of immunoglobulin type M (IgM antibodies is thought to be a major mechanism whereby B-1 cells limit atherosclerosis development. B-1 cell-derived IgM to oxidation specific epitopes (OSE on low density lipoproteins (LDL blocks oxidized LDL-induced inflammatory cytokine production and foam cell formation. However, whether PVAT contains B-1 cells and whether atheroprotective IgM is produced in PVAT is unknown. Results of the present study provide clear evidence that the majority of B cells in and around the aorta are derived from PVAT. Interestingly, a large proportion of these B cells belong to the B-1 subset with the B-1/B-2 ratio being 10-fold higher in PVAT relative to spleen and bone marrow. Moreover, PVAT contains significantly greater numbers of IgM secreting cells than the aorta. ApoE−/− mice with B cell-specific knockout of the gene encoding the helix-loop-helix factor Id3, known to have attenuated diet-induced atherosclerosis, have increased numbers of B-1b cells and increased IgM secreting cells in PVAT relative to littermate controls. Immunostaining of PVAT on human coronary arteries identified fat associated lymphoid clusters (FALCs harboring high numbers of B cells, and flow

  1. Predicting linear B-cell epitopes using string kernels

    Science.gov (United States)

    EL-Manzalawy, Yasser; Dobbs, Drena; Honavar, Vasant

    2008-01-01

    The identification and characterization of B-cell epitopes play an important role in vaccine design, immunodiagnostic tests, and antibody production. Therefore, computational tools for reliably predicting linear B-cell epitopes are highly desirable. We evaluated Support Vector Machine (SVM) classifiers trained utilizing five different kernel methods using fivefold cross-validation on a homology-reduced data set of 701 linear B-cell epitopes, extracted from Bcipep database, and 701 non-epitopes, randomly extracted from SwissProt sequences. Based on the results of our computational experiments, we propose BCPred, a novel method for predicting linear B-cell epitopes using the subsequence kernel. We show that the predictive performance of BCPred (AUC = 0.758) outperforms 11 SVM-based classifiers developed and evaluated in our experiments as well as our implementation of AAP (AUC = 0.7), a recently proposed method for predicting linear B-cell epitopes using amino acid pair antigenicity. Furthermore, we compared BCPred with AAP and ABCPred, a method that uses recurrent neural networks, using two data sets of unique B-cell epitopes that had been previously used to evaluate ABCPred. Analysis of the data sets used and the results of this comparison show that conclusions about the relative performance of different B-cell epitope prediction methods drawn on the basis of experiments using data sets of unique B-cell epitopes are likely to yield overly optimistic estimates of performance of evaluated methods. This argues for the use of carefully homology-reduced data sets in comparing B-cell epitope prediction methods to avoid misleading conclusions about how different methods compare to each other. Our homology-reduced data set and implementations of BCPred as well as the APP method are publicly available through our web-based server, BCPREDS, at: http://ailab.cs.iastate.edu/bcpreds/. PMID:18496882

  2. Human Memory B Cells in Healthy Gingiva, Gingivitis, and Periodontitis.

    Science.gov (United States)

    Mahanonda, Rangsini; Champaiboon, Chantrakorn; Subbalekha, Keskanya; Sa-Ard-Iam, Noppadol; Rattanathammatada, Warattaya; Thawanaphong, Saranya; Rerkyen, Pimprapa; Yoshimura, Fuminobu; Nagano, Keiji; Lang, Niklaus P; Pichyangkul, Sathit

    2016-08-01

    The presence of inflammatory infiltrates with B cells, specifically plasma cells, is the hallmark of periodontitis lesions. The composition of these infiltrates in various stages of homeostasis and disease development is not well documented. Human tissue biopsies from sites with gingival health (n = 29), gingivitis (n = 8), and periodontitis (n = 21) as well as gingival tissue after treated periodontitis (n = 6) were obtained and analyzed for their composition of B cell subsets. Ag specificity, Ig secretion, and expression of receptor activator of NF-κB ligand and granzyme B were performed. Although most of the B cell subsets in healthy gingiva and gingivitis tissues were CD19(+)CD27(+)CD38(-) memory B cells, the major B cell component in periodontitis was CD19(+)CD27(+)CD38(+)CD138(+)HLA-DR(low) plasma cells, not plasmablasts. Plasma cell aggregates were observed at the base of the periodontal pocket and scattered throughout the gingiva, especially apically toward the advancing front of the lesion. High expression of CXCL12, a proliferation-inducing ligand, B cell-activating factor, IL-10, IL-6, and IL-21 molecules involved in local B cell responses was detected in both gingivitis and periodontitis tissues. Periodontitis tissue plasma cells mainly secreted IgG specific to periodontal pathogens and also expressed receptor activator of NF-κB ligand, a bone resorption cytokine. Memory B cells resided in the connective tissue subjacent to the junctional epithelium in healthy gingiva. This suggested a role of memory B cells in maintaining periodontal homeostasis. Copyright © 2016 by The American Association of Immunologists, Inc.

  3. Wolf-Hirschhorn Syndrome Candidate 1 Is Necessary for Correct Hematopoietic and B Cell Development.

    Science.gov (United States)

    Campos-Sanchez, Elena; Deleyto-Seldas, Nerea; Dominguez, Veronica; Carrillo-de-Santa-Pau, Enrique; Ura, Kiyoe; Rocha, Pedro P; Kim, JungHyun; Aljoufi, Arafat; Esteve-Codina, Anna; Dabad, Marc; Gut, Marta; Heyn, Holger; Kaneda, Yasufumi; Nimura, Keisuke; Skok, Jane A; Martinez-Frias, Maria Luisa; Cobaleda, Cesar

    2017-05-23

    Immunodeficiency is one of the most important causes of mortality associated with Wolf-Hirschhorn syndrome (WHS), a severe rare disease originated by a deletion in chromosome 4p. The WHS candidate 1 (WHSC1) gene has been proposed as one of the main genes responsible for many of the alterations in WHS, but its mechanism of action is still unknown. Here, we present in vivo genetic evidence showing that Whsc1 plays an important role at several points of hematopoietic development. Particularly, our results demonstrate that both differentiation and function of Whsc1-deficient B cells are impaired at several key developmental stages due to profound molecular defects affecting B cell lineage specification, commitment, fitness, and proliferation, demonstrating a causal role for WHSC1 in the immunodeficiency of WHS patients. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Wolf-Hirschhorn Syndrome Candidate 1 Is Necessary for Correct Hematopoietic and B Cell Development

    Directory of Open Access Journals (Sweden)

    Elena Campos-Sanchez

    2017-05-01

    Full Text Available Immunodeficiency is one of the most important causes of mortality associated with Wolf-Hirschhorn syndrome (WHS, a severe rare disease originated by a deletion in chromosome 4p. The WHS candidate 1 (WHSC1 gene has been proposed as one of the main genes responsible for many of the alterations in WHS, but its mechanism of action is still unknown. Here, we present in vivo genetic evidence showing that Whsc1 plays an important role at several points of hematopoietic development. Particularly, our results demonstrate that both differentiation and function of Whsc1-deficient B cells are impaired at several key developmental stages due to profound molecular defects affecting B cell lineage specification, commitment, fitness, and proliferation, demonstrating a causal role for WHSC1 in the immunodeficiency of WHS patients.

  5. Clinical Implications of Phosphorylated STAT3 Expression in de novo Diffuse Large B-cell Lymphoma

    DEFF Research Database (Denmark)

    Ok, Chi Y; Chen, Jiayu; Xu-Monette, Ziju

    2014-01-01

    PURPOSE: Activated signal transducer and activator of transcription 3 (STAT3) regulates tumor growth, invasion, cell proliferation, angiogenesis, immune response, and survival. Data regarding expression of phosphorylated (activated) STAT3 in diffuse large B-cell lymphoma (DLBCL) and the impact...... of phosphorylated STAT3 (pSTAT3) on prognosis are limited. EXPERIMENTAL DESIGN: We evaluated expression of pSTAT3 in de novo DLBCL using immunohistochemistry, gene expression profiling (GEP), and gene set enrichment analysis (GSEA). Results were analyzed in correlation with cell-of-origin (COO), critical lymphoma...... biomarkers, and genetic translocations. RESULTS: pSTAT3 expression was observed in 16% of DLBCL and was associated with advanced stage, multiple extranodal sites of involvement, activated B-cell-like (ABC) subtype, MYC expression, and MYC/BCL2 expression. Expression of pSTAT3 predicted inferior overall...

  6. Longitudinal dynamics of the HIV-specific B cell response during intermittent treatment of primary HIV infection.

    Directory of Open Access Journals (Sweden)

    Godelieve J de Bree

    Full Text Available Neutralizing antibodies develop in natural HIV-1 infection. Their development often takes several years and may rely on chronic virus exposure. At the same time recent studies show that treatment early in infection may provide opportunities for immune preservation. However, it is unknown how intermittent treatment in early infection affects development of the humoral immune response over time. We investigate the effect of cART in early HIV infection on the properties of the memory B cell compartment following 6 months of cART or in the absence of treatment. The patients included participated in the Primo-SHM trial where patients with an early HIV-1 infection were randomized to no treatment or treatment for 24 or 60 weeks.Primo-SHM trial patients selected for the present study were untreated (n = 23 or treated for 24 weeks (n = 24. Here we investigate memory B cell properties at viral set-point and at a late time point (respectively median 54 and 73 weeks before (re-initiation of treatment.At viral set-point, the memory B cell compartment in treated patients demonstrated significantly lower fractions of antigen-primed, activated, memory B cells (p = 0.006. In contrast to untreated patients, in treated patients the humoral HIV-specific response reached a set point over time. At a transcriptional level, sets of genes that showed enhanced expression in memory B cells at viral setpoint in untreated patients, conversely showed rapid increase of expression of the same genes in treated patients at the late time point.These data suggest that, although the memory B cell compartment is phenotypically preserved until viral setpoint after treatment interruption, the development of the HIV-specific antibody response may benefit from exposure to HIV. The effect of viral exposure on B cell properties is also reflected by longitudinal changes in transcriptional profile in memory B cells over time in early treated patients.

  7. Predicting the survival time for diffuse large B-cell lymphoma using microarray data

    OpenAIRE

    Khoshhali, Mehri; Mahjub, Hossein; Saidijam, Massoud; Poorolajal, Jalal; Soltanian, Ali Reza

    2012-01-01

    The present study was conducted to predict survival time in patients with diffuse large B-cell lymphoma, DLBCL, based on microarray data using Cox regression model combined with seven dimension reduction methods. This historical cohort included 2042 gene expression measurements from 40 patients with DLBCL. In order to predict survival, a combination of Cox regression model was used with seven methods for dimension reduction or shrinkage including univariate selection, forward stepwise selecti...

  8. Ku70 is required for late B cell development and immunoglobulin heavy chain class switching.

    Science.gov (United States)

    Manis, J P; Gu, Y; Lansford, R; Sonoda, E; Ferrini, R; Davidson, L; Rajewsky, K; Alt, F W

    1998-06-15

    Immunoglobulin (Ig) heavy chain (HC) class switch recombination (CSR) is a late B cell process that involves intrachromosomal DNA rearrangement. Ku70 and Ku80 form a DNA end-binding complex required for DNA double strand break repair and V(D)J recombination. Ku70(-/-) (K70T) mice, like recombination activating gene (RAG)-1- or RAG-2-deficient (R1T or R2T) mice, have impaired B and T cell development at an early progenitor stage, which is thought to result at least in part from defective V(D)J recombination (Gu, Y., K.J. Seidl, G.A. Rathbun, C. Zhu, J.P. Manis, N. van der Stoep, L. Davidson, H.L. Cheng, J.M. Sekiguchi, K. Frank, et al. 1997. Immunity. 7:653-665; Ouyang, H., A. Nussenzweig, A. Kurimasa, V.C. Soares, X. Li, C. Cordon-Cardo, W. Li, N. Cheong, M. Nussenzweig, G. Iliakis, et al. 1997. J. Exp. Med. 186:921-929). Therefore, to examine the potential role of Ku70 in CSR, we generated K70T mice that carry a germline Ig HC locus in which the JH region was replaced with a functionally rearranged VH(D)JH and Ig lambda light chain transgene (referred to as K70T/HL mice). Previously, we have shown that B cells from R1T or R2T mice carrying these rearranged Ig genes (R1T/HL or R2T/HL mice) can undergo CSR to IgG isotypes (Lansford, R., J. Manis, E. Sonoda, K. Rajewsky, and F. Alt. 1998. Int. Immunol. 10:325-332). K70T/HL mice had significant numbers of peripheral surface IgM+ B cells, which generated serum IgM levels similar to those of R2T/HL mice. However, in contrast to R2T/HL mice, K70T/HL mice had no detectable serum IgG isotypes. In vitro culture of K70T/HL B cells with agents that induce CSR in normal or R2T/HL B cells did lead to the induction of germline CH transcripts, indicating that initial signaling pathways for CSR were intact in K70T/HL cells. However, treatment with such agents did not lead to detectable CSR by K70T/HL B cells, and instead, led to cell death within 72 h. We conclude that Ku70 is required for the generation of B cells that have

  9. Immunoglobulin and B-cell disturbances in patients with chronic idiopathic neutropenia.

    Science.gov (United States)

    Mavroudi, Irene; Eliopoulos, Aristides G; Pontikoglou, Charalampos; Pyrovolaki, Katerina; Damianaki, Athina; Koutala, Helen; Zervou, Maria I; Ximeri, Maria; Mastrodemou, Semeli; Kanellou, Peggy; Goulielmos, George N; Papadaki, Helen A

    2017-10-01

    Chronic idiopathic neutropenia (CIN) is a granulocytic disorder associated with presence of activated, myelosuppressive T-lymphocytes. In the present study we have evaluated constituents of humoral immunity in CIN patients (n=48) compared to healthy controls (n=52). CIN patients displayed lower serum IgG levels due to a reduction in IgG1, IgG3, IgG4 but not IgG2, lower IgA and increased IgM levels compared to controls. The proportion of CD19 + cells did not differ between patients and controls; however the proportion of the naïve IgD + /CD27 - B-cells was increased and the proportion of class-switched memory IgD - /CD27 + B-cells was decreased in the patients. The percentage of CD40 + B-cells did not differ between patients and controls and no aberrations in the CD40-meadiated signal transduction pathway or in CD40-gene polymorphisms were identified. These data provide further evidence that immune disturbances are associated with the pathophysiology of CIN and point out for the first time the implication of the B-cell system. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. CD40 signaling synergizes with TLR-2 in the BCR independent activation of resting B cells.

    Directory of Open Access Journals (Sweden)

    Shweta Jain

    Full Text Available Conventionally, signaling through BCR initiates sequence of events necessary for activation and differentiation of B cells. We report an alternative approach, independent of BCR, for stimulating resting B (RB cells, by involving TLR-2 and CD40--molecules crucial for innate and adaptive immunity. CD40 triggering of TLR-2 stimulated RB cells significantly augments their activation, proliferation and differentiation. It also substantially ameliorates the calcium flux, antigen uptake capacity and ability of B cells to activate T cells. The survival of RB cells was improved and it increases the number of cells expressing activation induced deaminase (AID, signifying class switch recombination (CSR. Further, we also observed increased activation rate and decreased threshold period required for optimum stimulation of RB cells. These results corroborate well with microarray gene expression data. This study provides novel insights into coordination between the molecules of innate and adaptive immunity in activating B cells, in a BCR independent manner. This strategy can be exploited to design vaccines to bolster B cell activation and antigen presenting efficiency, leading to faster and better immune response.

  11. On the Pathogenesis Trail: What Marker B Cell Clones Tell Us about Inflammatory Bowel Disease

    Directory of Open Access Journals (Sweden)

    Jonathan Braun

    1996-01-01

    Full Text Available Clonal patterns of B cell activity have been recognized in inflammatory bowel disease, most notably in the immunogenetic relationship of perinuclear-antineutrophil cytoplasmic antibodies to ulcerative colitis. Conceptually, this most likely reflects the B cell response to antigens predominating at these sites of mucosal inflammation. Identification of these B cell clones and their antigenic targets may be of pathogenetic and practical importance to diagnosis and treatment. The authors describe strategies to identify such clones, based on recent advances in the characterization and detection of antibody gene products. As an example of this strategy, a clonal detection system was used to identify new marker antibodies potentially useful in the laboratory diagnosis of Crohn’s disease and ulcerative colitis. One surprising outcome of such studies is the unexpected and specific association of the B cell clonal response in Campylobacter jejuni enterocolitis and inflammatory bowel disease. By analogy to the pathogenetic role of Helicobacter pylori-induced mucositis in peptic ulcer disease, this evidence renews attention to the role of C jejuni in the initiation of ulcerative colitis and Crohn’s disease.

  12. Initiation of Antiviral B Cell Immunity Relies on Innate Signals from Spatially Positioned NKT Cells.

    Science.gov (United States)

    Gaya, Mauro; Barral, Patricia; Burbage, Marianne; Aggarwal, Shweta; Montaner, Beatriz; Warren Navia, Andrew; Aid, Malika; Tsui, Carlson; Maldonado, Paula; Nair, Usha; Ghneim, Khader; Fallon, Padraic G; Sekaly, Rafick-Pierre; Barouch, Dan H; Shalek, Alex K; Bruckbauer, Andreas; Strid, Jessica; Batista, Facundo D

    2018-01-25

    B cells constitute an essential line of defense from pathogenic infections through the generation of class-switched antibody-secreting cells (ASCs) in germinal centers. Although this process is known to be regulated by follicular helper T (TfH) cells, the mechanism by which B cells initially seed germinal center reactions remains elusive. We found that NKT cells, a population of innate-like T lymphocytes, are critical for the induction of B cell immunity upon viral infection. The positioning of NKT cells at the interfollicular areas of lymph nodes facilitates both their direct priming by resident macrophages and the localized delivery of innate signals to antigen-experienced B cells. Indeed, NKT cells secrete an early wave of IL-4 and constitute up to 70% of the total IL-4-producing cells during the initial stages of infection. Importantly, the requirement of this innate immunity arm appears to be evolutionarily conserved because early NKT and IL-4 gene signatures also positively correlate with the levels of neutralizing antibodies in Zika-virus-infected macaques. In conclusion, our data support a model wherein a pre-TfH wave of IL-4 secreted by interfollicular NKT cells triggers the seeding of germinal center cells and serves as an innate link between viral infection and B cell immunity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. A B-cell lymphoma case that is unclassifiable, and intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma of lacrimal gland

    Directory of Open Access Journals (Sweden)

    Yunoki T

    2017-02-01

    Full Text Available Tatsuya Yunoki,1 Jun Murakami,2 Yukihiro Imagawa,3 Takahiko Nakajima,4 Atsushi Hayashi1 1Department of Ophthalmology, 2Department of Gastroenterology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 3Department of Ophthalmology, Osaka Kaisei Hospital, Osaka, 4Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan Abstract: A 60-year-old woman presented with acute eyelid swelling and a subcutaneous hemorrhage in the right eye. Magnetic resonance imaging showed a spherical tumor of the lacrimal gland. The tumor was removed by the Kroenlein method. We diagnosed as a B-cell lymphoma that is unclassifiable, and intermediate between diffuse large B-cell lymphoma (DLBCL and Burkitt lymphoma (BL (intermediate DLBCL/BL based on its immunohistopathological examination and c-MYC/IgH rearrangement. We administered six cycles of dose-adjusted-EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin hydrochloride, and rituximab therapy, and remission of the lymphoma was obtained. This is the first case of an intermediate DLBCL/BL of a lacrimal gland. Keywords: diffuse large B-cell lymphoma, Burkitt lymphoma, c-MYC gene, fluorescence in situ hybridization

  14. B cell development in the bone marrow is regulated by homeostatic feedback exerted by mature B cells

    Directory of Open Access Journals (Sweden)

    Gitit eShahaf

    2016-03-01

    Full Text Available Cellular homeostasis in the B cell compartment is strictly imposed to balance cell production and cell loss. However, it is not clear whether B cell development in the bone marrow (BM is an autonomous process or subjected to regulation by the peripheral B cell compartment. To specifically address this question, we used mice transgenic for human CD20, where effective depletion of B lineage cells is obtained upon administration of mouse-anti-human CD20 antibodies, in the absence of any effect on other cell lineages and/or tissues. We followed the kinetics of B cell return to equilibrium by BrdU labeling and flow cytometry and analyzed the resulting data by mathematical modeling. Labeling was much faster in depleted mice. Compared to control mice, B cell-depleted mice exhibited a higher proliferation rate in the pro-/pre-B compartment, and higher cell death and lower differentiation in the immature B cell compartment. We validated the first result by analysis of the expression of Ki67, the nuclear protein expressed in proliferating cells, and the second using Annexin-V staining. Collectively, our results suggest that B lymphopoiesis is subjected to homeostatic feedback mechanisms imposed by mature B cells in the peripheral compartment.

  15. B-Cell-Specific Diversion of Glucose Carbon Utilization Reveals a Unique Vulnerability in B Cell Malignancies.

    Science.gov (United States)

    Xiao, Gang; Chan, Lai N; Klemm, Lars; Braas, Daniel; Chen, Zhengshan; Geng, Huimin; Zhang, Qiuyi Chen; Aghajanirefah, Ali; Cosgun, Kadriye Nehir; Sadras, Teresa; Lee, Jaewoong; Mirzapoiazova, Tamara; Salgia, Ravi; Ernst, Thomas; Hochhaus, Andreas; Jumaa, Hassan; Jiang, Xiaoyan; Weinstock, David M; Graeber, Thomas G; Müschen, Markus

    2018-04-05

    B cell activation during normal immune responses and oncogenic transformation impose increased metabolic demands on B cells and their ability to retain redox homeostasis. While the serine/threonine-protein phosphatase 2A (PP2A) was identified as a tumor suppressor in multiple types of cancer, our genetic studies revealed an essential role of PP2A in B cell tumors. Thereby, PP2A redirects glucose carbon utilization from glycolysis to the pentose phosphate pathway (PPP) to salvage oxidative stress. This unique vulnerability reflects constitutively low PPP activity in B cells and transcriptional repression of G6PD and other key PPP enzymes by the B cell transcription factors PAX5 and IKZF1. Reflecting B-cell-specific transcriptional PPP-repression, glucose carbon utilization in B cells is heavily skewed in favor of glycolysis resulting in lack of PPP-dependent antioxidant protection. These findings reveal a gatekeeper function of the PPP in a broad range of B cell malignancies that can be efficiently targeted by small molecule inhibition of PP2A and G6PD. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Cloning of B cell-specific membrane tetraspanning molecule BTS possessing B cell proliferation-inhibitory function.

    Science.gov (United States)

    Suenaga, Tadahiro; Arase, Hisashi; Yamasaki, Sho; Kohno, Masayuki; Yokosuka, Tadashi; Takeuchi, Arata; Hattori, Takamichi; Saito, Takashi

    2007-11-01

    Lymphocyte proliferation is regulated by signals through antigen receptors, co-stimulatory receptors, and other positive and negative modulators. Several membrane tetraspanning molecules are also involved in the regulation of lymphocyte growth and death. We cloned a new B cell-specific tetraspanning (BTS) membrane molecule, which is similar to CD20 in terms of expression, structure and function. BTS is specifically expressed in the B cell line and its expression is increased after the pre-B cell stage. BTS is expressed in intracellular granules and on the cell surface. Overexpression of BTS in immature B cell lines induces growth retardation through inhibition of cell cycle progression and cell size increase without inducing apoptosis. This inhibitory function is mediated predominantly by the N terminus of BTS. The development of mature B cells is inhibited in transgenic mice expressing BTS, suggesting that BTS is involved in the in vivo regulation of B cells. These results indicate that BTS plays a role in the regulation of cell division and B cell growth.

  17. Various domains of the B-cell regulatory molecule CD72 has diverged at different rates in mammals

    DEFF Research Database (Denmark)

    Petersen, Cathrine Bie; Hillig, Ann-Britt Nygaard; Fredholm, Merete

    2007-01-01

    We report the cloning of the porcine B-cell co-receptor CD72, as well as genomic mapping and examination of transcription. The B-cell receptor (BCR) complex mediates signalling upon antigen recognition by the membrane bound BCR. Several co-receptors modulate this signal positively or negatively. CD......72 has been shown to be a negatively regulating BCR co-receptor. We isolated and sequenced three porcine CD72 transcript variants. Using a pig radiation hybrid panel we found the porcien CD72 gene to be located on chromosome 1q21-28 in a region syntenic to human chromosome 9. The porcine CD72 gene...

  18. COMPUTATION MODELING OF TCDD DISRUPTION OF B CELL TERMINAL DIFFERENTIATION

    Science.gov (United States)

    In this study, we established a computational model describing the molecular circuit underlying B cell terminal differentiation and how TCDD may affect this process by impinging upon various molecular targets.

  19. B-Cell waste classification sampling and analysis plan

    International Nuclear Information System (INIS)

    HOBART, R.L.

    1999-01-01

    This report documents the methods used to collect and analyze samples to obtain data necessary to verify and/or determine the radionuclide content of the 324 Facility B-Cell decontamination and decommissioning waste stream

  20. Diversity among memory B cells: origin, consequences, and utility.

    Science.gov (United States)

    Tarlinton, David; Good-Jacobson, Kim

    2013-09-13

    Immunological memory is the residuum of a successful immune response that in the B cell lineage comprises long-lived plasma cells and long-lived memory B cells. It is apparent that distinct classes of memory B cells exist, distinguishable by, among other things, immunoglobulin isotype, location, and passage through the germinal center. Some of this variation is due to the nature of the antigen, and some appears to be inherent to the process of forming memory. Here, we consider the heterogeneity in development and phenotype of memory B cells and whether particular functions are partitioned into distinct subsets. We consider also how understanding the details of generating memory may provide opportunities to develop better, functionally targeted vaccines.

  1. Parathyroid hormone resistance and B cell lymphopenia in propionic acidemia.

    Science.gov (United States)

    Griffin, T A; Hostoffer, R W; Tserng, K Y; Lebovitz, D J; Hoppel, C L; Mosser, J L; Kaplan, D; Kerr, D S

    1996-07-01

    The mechanisms of hypocalcemia, recurrent infections and hypogammaglobulinemia associated with metabolic decompensation of propionic acidemia due to propionyl-CoA carboxylase deficiency have not been defined. A 7-week-old infant with this disorder presented with severe hypocalcemia and B cell lymphopenia during an episode of metabolic acidosis and hyperammonemia. Hypocalcemia (1.1 mmol l-1) was associated with elevated serum intact parathyroid hormone (122 ng l-1), hyperphosphatemia, hypophosphaturia and hypercalcuria, indicating parathyroid hormone resistance. B cell lymphopenia (20 cells microliters-1) was associated with transient neutropenia, anemia and subsequent hypogamma-globulinemia (IgG < 294 mg dl-1, IgM < 8 mg dl-1, IgA < 8 mg dl-1), while T cells were normal. Parathyroid hormone resistance and B cell lymphopenia resolved following treatment with hemodialysis, diet and carnitine. These complications may be due to interference with parathyroid hormone renal tubular action and B cell maturation/proliferation by accumulated organic acids.

  2. Recent advances in B-cell epitope prediction methods

    Science.gov (United States)

    2010-01-01

    Identification of epitopes that invoke strong responses from B-cells is one of the key steps in designing effective vaccines against pathogens. Because experimental determination of epitopes is expensive in terms of cost, time, and effort involved, there is an urgent need for computational methods for reliable identification of B-cell epitopes. Although several computational tools for predicting B-cell epitopes have become available in recent years, the predictive performance of existing tools remains far from ideal. We review recent advances in computational methods for B-cell epitope prediction, identify some gaps in the current state of the art, and outline some promising directions for improving the reliability of such methods. PMID:21067544

  3. BRILIA: Integrated Tool for High-Throughput Annotation and Lineage Tree Assembly of B-Cell Repertoires

    Science.gov (United States)

    Lee, Donald W.; Khavrutskii, Ilja V.; Wallqvist, Anders; Bavari, Sina; Cooper, Christopher L.; Chaudhury, Sidhartha

    2017-01-01

    The somatic diversity of antigen-recognizing B-cell receptors (BCRs) arises from Variable (V), Diversity (D), and Joining (J) (VDJ) recombination and somatic hypermutation (SHM) during B-cell development and affinity maturation. The VDJ junction of the BCR heavy chain forms the highly variable complementarity determining region 3 (CDR3), which plays a critical role in antigen specificity and binding affinity. Tracking the selection and mutation of the CDR3 can be useful in characterizing humoral responses to infection and vaccination. Although tens to hundreds of thousands of unique BCR genes within an expressed B-cell repertoire can now be resolved with high-throughput sequencing, tracking SHMs is still challenging because existing annotation methods are often limited by poor annotation coverage, inconsistent SHM identification across the VDJ junction, or lack of B-cell lineage data. Here, we present B-cell repertoire inductive lineage and immunosequence annotator (BRILIA), an algorithm that leverages repertoire-wide sequencing data to globally improve the VDJ annotation coverage, lineage tree assembly, and SHM identification. On benchmark tests against simulated human and mouse BCR repertoires, BRILIA correctly annotated germline and clonally expanded sequences with 94 and 70% accuracy, respectively, and it has a 90% SHM-positive prediction rate in the CDR3 of heavily mutated sequences; these are substantial improvements over existing methods. We used BRILIA to process BCR sequences obtained from splenic germinal center B cells extracted from C57BL/6 mice. BRILIA returned robust B-cell lineage trees and yielded SHM patterns that are consistent across the VDJ junction and agree with known biological mechanisms of SHM. By contrast, existing BCR annotation tools, which do not account for repertoire-wide clonal relationships, systematically underestimated both the size of clonally related B-cell clusters and yielded inconsistent SHM frequencies. We demonstrate

  4. Antibodies That Block or Activate Mouse B Cell Activating Factor of the Tumor Necrosis Factor (TNF) Family (BAFF), Respectively, Induce B Cell Depletion or B Cell Hyperplasia*

    Science.gov (United States)

    Kowalczyk-Quintas, Christine; Schuepbach-Mallepell, Sonia; Vigolo, Michele; Willen, Laure; Tardivel, Aubry; Smulski, Cristian R.; Zheng, Timothy S.; Gommerman, Jennifer; Hess, Henry; Gottenberg, Jacques-Eric; Mackay, Fabienne; Donzé, Olivier

    2016-01-01

    B cell activating factor of the TNF family (BAFF), also known as B lymphocyte stimulator, is a ligand required for the generation and maintenance of B lymphocytes. In this study, the ability of different monoclonal antibodies to recognize, inhibit, or activate mouse BAFF was investigated. One of them, a mouse IgG1 named Sandy-2, prevented the binding of BAFF to all of its receptors, BAFF receptor, transmembrane activator and calcium modulating ligand interactor, and B cell maturation antigen, at a stoichiometric ratio; blocked the activity of mouse BAFF on a variety of cell-based reporter assays; and antagonized the prosurvival action of BAFF on primary mouse B cells in vitro. A single administration of Sandy-2 in mice induced B cell depletion within 2 weeks, down to levels close to those observed in BAFF-deficient mice. This depletion could then be maintained with a chronic treatment. Sandy-2 and a previously described rat IgG1 antibody, 5A8, also formed a pair suitable for the sensitive detection of endogenous circulating BAFF by ELISA or using a homogenous assay. Interestingly, 5A8 and Sandy-5 displayed activities opposite to that of Sandy-2 by stimulating recombinant BAFF in vitro and endogenous BAFF in vivo. These tools will prove useful for the detection and functional manipulation of endogenous mouse BAFF and provide an alternative to the widely used BAFF receptor-Fc decoy receptor for the specific depletion of BAFF in mice. PMID:27451394

  5. High-affinity memory B cells induced by conjugate vaccines against weak tumor antigens are vulnerable to nonconjugated antigen.

    Science.gov (United States)

    Savelyeva, Natalia; Shipton, Michael; Suchacki, Amy; Babbage, Gavin; Stevenson, Freda K

    2011-07-21

    Induction of antibody-mediated immunity against hematologic malignancies requires CD4(+) T-cell help, but weak tumor antigens generally fail to induce adequate T-cell responses, or to overcome tolerance. Conjugate vaccines can harness alternative help to activate responses, but memory B cells may then be exposed to leaking tumor-derived antigen without CD4(+) T-cell support. We showed previously using lymphoma-derived idiotypic antigen that exposure to "helpless" antigen silences the majority of memory IgG(+) B cells. Transfer experiments now indicate that silencing is permanent. In marked contrast to IgG, most coexisting IgM(+) memory B cells exposed to "helpless" antigen survive. Confirmation in a hapten (NP) model allowed measurement of affinity, revealing this, rather than isotype, as the determinant of survival. IgM(+) B cells had Ig variable region gene usage similar to IgG but with fewer somatic mutations. Survival of memory B cells appears variably controlled by affinity for antigen, allowing a minority of low affinity IgG(+), but most IgM(+), memory B cells to escape deletion in the absence of T-cell help. The latter remain, but the majority fail to undergo isotype switch. These findings could apply to other tumor antigens and are relevant for vaccination strategies aimed to induce long-term antibody.

  6. Prognostic impact of concurrent MYC and BCL6 rearrangements and expression in de novo diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Ye, Qing; Xu-Monette, Zijun Y; Tzankov, Alexandar

    2016-01-01

    Double-hit B-cell lymphoma is a common designation for a group of tumors characterized by concurrent translocations of MYC and BCL2, BCL6, or other genes. The prognosis of concurrent MYC and BCL6 translocations is not well known. In this study, we assessed rearrangements and expression of MYC, BCL2...... with MYC translocation (observed in 2.0% of diffuse large B-cell lymphoma) predicted poorer survival in diffuse large B-cell lymphoma patients. Diffuse large B-cell lymphoma patients with MYC/BCL6 co-expression did have significantly poorer survival, however, MYC/BCL6 co-expression had no effect...... on prognosis in the absence of MYC/BCL2 co-expression, and had no additive impact in MYC+/BCL2+ cases. The isolated MYC+/BCL6+/BCL2- subset, more frequent in germinal center B-cell like diffuse large B-cell lymphoma, had significantly better survival compared with the isolated MYC+/BCL2+/BCL6- subset (more...

  7. Corruption of human follicular B-lymphocyte trafficking by a B-cell superantigen.

    Science.gov (United States)

    Borhis, Gwenoline; Viau, Muriel; Badr, Gamal; Richard, Yolande; Zouali, Moncef

    2012-05-09

    Protein A (SpA) of Staphylococcus aureus is known to target the paratope of immunoglobulins expressing V(H)3 genes, and to delete marginal zone B cells and B-1a in vivo. We have discovered that SpA endows S. aureus with the potential to subvert B-cell trafficking in the host. We found that SpA, whose Fc-binding site has been inactivated, binds essentially to naïve B cells and induces a long-lasting decrease in CXCR4 expression and in B-cell chemotaxis to CXCL12. Competition experiments indicated that SpA does not interfere with binding of CXCR4 ligands and does not directly bind to CXCR4. This conclusion is strongly supported by the inability of SpA to modulate clathrin-mediated CXCR4 internalization, which contrasts with the potent effect of anti-immunoglobin M (IgM) antibodies. Microscopy and biochemical experiments confirmed that SpA binds to the surface IgM/IgD complex and induces its clathrin-dependent internalization. Concomitantly, the SpA-induced signaling leads to protein kinase C-dependent CXCR4 downmodulation, suggesting that SpA impairs the recycling of CXCR4, a postclathrin process that leads to either degradation into lysozomes or de novo expression at the cell surface. In addition to providing novel insight into disruption of B-cell trafficking by an infectious agent, our findings may have therapeutic implications. Because CXCR4 has been associated with cancer metastasis and with certain autoimmune diseases, SpA behaves as an evolutionary tailored highly specific, chemokine receptor inhibitor that may have value in addition to conventional cytotoxic therapy in patients with various malignancies and immune-mediated diseases.

  8. 1,25-dihydroxyvitamin D3 impairs NF-κB activation in human naive B cells

    International Nuclear Information System (INIS)

    Geldmeyer-Hilt, Kerstin; Heine, Guido; Hartmann, Bjoern; Baumgrass, Ria; Radbruch, Andreas; Worm, Margitta

    2011-01-01

    Highlights: → In naive B cells, VDR activation by calcitriol results in reduced NF-κB p105 and p50 protein expression. → Ligating the VDR with calcitriol causes reduced nuclear translocation of NF-κB p65. → Reduced nuclear amount of p65 after calcitriol incubation results in reduced binding of p65 on the p105 promoter. → Thus, vitamin D receptor signaling may reduce or prevent activation of B cells and unwanted immune responses, e.g. in IgE dependent diseases such as allergic asthma. -- Abstract: 1α,25-dihydroxyvitamin D 3 (calcitriol), the bioactive metabolite of vitamin D, modulates the activation and inhibits IgE production of anti-CD40 and IL-4 stimulated human peripheral B cells. Engagement of CD40 results in NF-κB p50 activation, which is essential for the class switch to IgE. Herein, we investigated by which mechanism calcitriol modulates NF-κB mediated activation of human naive B cells. Naive B cells were predominantly targeted by calcitriol in comparison with memory B cells as shown by pronounced induction of the VDR target gene cyp24a1. Vitamin D receptor activation resulted in a strongly reduced p105/p50 protein and mRNA expression in human naive B cells. This effect is mediated by impaired nuclear translocation of p65 and consequently reduced binding of p65 to its binding site in the p105 promoter. Our data indicate that the vitamin D receptor reduces NF-κB activation by interference with NF-κB p65 and p105. Thus, the vitamin D receptor inhibits costimulatory signal transduction in naive B cells, namely by reducing CD40 signaling.

  9. Human regulatory B cells control the TFH cell response.

    Science.gov (United States)

    Achour, Achouak; Simon, Quentin; Mohr, Audrey; Séité, Jean-François; Youinou, Pierre; Bendaoud, Boutahar; Ghedira, Ibtissem; Pers, Jacques-Olivier; Jamin, Christophe

    2017-07-01

    Follicular helper T (T FH ) cells support terminal B-cell differentiation. Human regulatory B (Breg) cells modulate cellular responses, but their control of T FH cell-dependent humoral immune responses is unknown. We sought to assess the role of Breg cells on T FH cell development and function. Human T cells were polyclonally stimulated in the presence of IL-12 and IL-21 to generate T FH cells. They were cocultured with B cells to induce their terminal differentiation. Breg cells were included in these cultures, and their effects were evaluated by using flow cytometry and ELISA. B-cell lymphoma 6, IL-21, inducible costimulator, CXCR5, and programmed cell death protein 1 (PD-1) expressions increased on stimulated human T cells, characterizing T FH cell maturation. In cocultures they differentiated B cells into CD138 + plasma and IgD - CD27 + memory cells and triggered immunoglobulin secretions. Breg cells obtained by Toll-like receptor 9 and CD40 activation of B cells prevented T FH cell development. Added to T FH cell and B-cell cocultures, they inhibited B-cell differentiation, impeded immunoglobulin secretions, and expanded Foxp3 + CXCR5 + PD-1 + follicular regulatory T cells. Breg cells modulated IL-21 receptor expressions on T FH cells and B cells, and their suppressive activities involved CD40, CD80, CD86, and intercellular adhesion molecule interactions and required production of IL-10 and TGF-β. Human Breg cells control T FH cell maturation, expand follicular regulatory T cells, and inhibit the T FH cell-mediated antibody secretion. These novel observations demonstrate a role for the Breg cell in germinal center reactions and suggest that deficient activities might impair the T FH cell-dependent control of humoral immunity and might lead to the development of aberrant autoimmune responses. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  10. Novel disease targets and management approaches for diffuse large B-cell lymphoma.

    Science.gov (United States)

    Wilson, Wyndham H; Hernandez-Ilizaliturri, Francisco J; Dunleavy, Kieron; Little, Richard F; O'Connor, Owen A

    2010-08-01

    Diffuse large B-cell lymphoma (DLBCL) responds well to treatment with CHOP and the R-CHOP regimen, but a subset of patients still fail to achieve complete or durable responses. Recent advances in gene expression profiling have led to the identification of three different subtypes of DLBCL, and confirmed that patients with the activated B-cell (ABC) disease subtype are less likely to respond well to CHOP-based regimens than those with germinal centre B-cell-type (GCB) disease. This discovery could herald the use of gene expression profiling to aid treatment decisions in DLBCL, and help identify the most effective management strategies for patients. Treatment options for patients with relapsed or refractory DLBCL are limited and several novel agents are being developed to address this unmet clinical need. Novel agents developed to treat plasma cell disorders such as multiple myeloma have shown promising activity in patients with NHL. Indeed, the immunomodulatory agent lenalidomide and the proteasome inhibitors bortezomib and carfilzomib, as single agents or in combination with chemotherapy, have already demonstrated promising activity in patients with the ABC subtype of DLBCL. One should not be complacent however when applying these agents to new disease types, because dose and drug scheduling can have marked effects on the responses achieved with investigational agents. As more targeted agents are developed, the timing of administration with other agents in clinical trials will become increasingly important to ensure maximal efficacy while minimizing side effects.

  11. Trib1 Is Overexpressed in Systemic Lupus Erythematosus, While It Regulates Immunoglobulin Production in Murine B Cells

    Directory of Open Access Journals (Sweden)

    Léa Simoni

    2018-03-01

    Full Text Available Systemic lupus erythematosus (SLE is a severe and heterogeneous autoimmune disease with a complex genetic etiology, characterized by the production of various pathogenic autoantibodies, which participate in end-organ damages. The majority of human SLE occurs in adults as a polygenic disease, and clinical flares interspersed with silent phases of various lengths characterize the usual evolution of the disease in time. Trying to understand the mechanism of the different phenotypic traits of the disease, and considering the central role of B cells in SLE, we previously performed a detailed wide analysis of gene expression variation in B cells from quiescent SLE patients. This analysis pointed out an overexpression of TRIB1. TRIB1 is a pseudokinase that has been implicated in the development of leukemia and also metabolic disorders. It is hypothesized that Trib1 plays an adapter or scaffold function in signaling pathways, notably in MAPK pathways. Therefore, we planned to understand the functional significance of TRIB1 overexpression in B cells in SLE. We produced a new knock-in model with B-cell-specific overexpression of Trib1. We showed that overexpression of Trib1 specifically in B cells does not impact B cell development nor induce any development of SLE symptoms in the mice. By contrast, Trib1 has a negative regulatory function on the production of immunoglobulins, notably IgG1, but also on the production of autoantibodies in an induced model. We observed a decrease of Erk activation in BCR-stimulated Trib1 overexpressing B cells. Finally, we searched for Trib1 partners in B cells by proteomic analysis in order to explore the regulatory function of Trib1 in B cells. Interestingly, we find an interaction between Trib1 and CD72, a negative regulator of B cells whose deficiency in mice leads to the development of autoimmunity. In conclusion, the overexpression of Trib1 could be one of the molecular pathways implicated in the negative regulation

  12. Increased numbers of spleen colony forming units in B cell deficient CBA/N mice

    International Nuclear Information System (INIS)

    Wiktor-Jedrzejczak, W.; Krupienicz, A.; Scher, I.

    1986-01-01

    The formation of exogenous and endogenous spleen colonies was studied in immune-defective mice expressing the CBA/N X-linked xid gene. Bone marrow and spleen cells of immune deficient mice formed increased numbers of eight-day exogenous spleen colonies when transferred to either normal or B cell deficient lethally irradiated recipients. Moreover, defective mice showed increased formation of five-day endogenous spleen colonies (derived from transient endogenous colony forming units; T-CFU) and of ten-day endogenous spleen colonies (derived from CFU-S). Among the possible mechanisms responsible for the observed effects, the most probable appears the one in which decreased numbers of B cell precursors stimulate stem cell pools through a feedback mechanism. (orig.) [de

  13. Subcutaneous 'lipoma-like' B-cell lymphoma associated with HCV infection: a new presentation of primary extranodal marginal zone B-cell lymphoma of MALT.

    Science.gov (United States)

    Paulli, M; Arcaini, L; Lucioni, M; Boveri, E; Capello, D; Passamonti, F; Merli, M; Rattotti, S; Rossi, D; Riboni, R; Berti, E; Magrini, U; Bruno, R; Gaidano, G; Lazzarino, M

    2010-06-01

    Hepatitis C virus (HCV) infection has been linked to lymphoproliferative disorders. Marginal zone B-cell lymphoma (MZL) represents one of the most frequent lymphoma subtypes associated with HCV infection. We describe an unusual subset of HCV-associated MZL characterized by subcutaneous presentation. A series of 12 HCV-positive patients presenting with subcutaneous nodules that revealed lymphoma infiltration at biopsy. Molecular analysis of immunoglobulin heavy chain (IGH) gene rearrangement and FISH investigations for t(11;18)(q21;q21) and t(14;18)(q32;q21) were carried out in nine patients. The 12 patients (median age 69.5 years), all with positive HCV serology, presented with single or multiple subcutaneous nodules resembling lipomas. Histologically the lesions showed lymphoid infiltrates, consistent with extranodal MZL of mucosa-associated lymphoid tissue (MALT). Functional IGH gene rearrangements were identified in nine tested patients, with somatic mutations in 82%, indicating a histogenesis from germinal center-experienced B cells. The t(11;18) was found in two of nine cases. Staging did not show any other lymphoma localization. In two patients, a response was achieved with antiviral treatment. Extracutaneous spread to MALT sites occurred in a case. Our observations expand the spectrum of HCV-associated lymphomas to include a subset of extranodal MZL characterized by a novel primary 'lipoma-like' subcutaneous presentation and indolent clinical course.

  14. Antibodies That Block or Activate Mouse B Cell Activating Factor of the Tumor Necrosis Factor (TNF) Family (BAFF), Respectively, Induce B Cell Depletion or B Cell Hyperplasia.

    Science.gov (United States)

    Kowalczyk-Quintas, Christine; Schuepbach-Mallepell, Sonia; Vigolo, Michele; Willen, Laure; Tardivel, Aubry; Smulski, Cristian R; Zheng, Timothy S; Gommerman, Jennifer; Hess, Henry; Gottenberg, Jacques-Eric; Mackay, Fabienne; Donzé, Olivier; Schneider, Pascal

    2016-09-16

    B cell activating factor of the TNF family (BAFF), also known as B lymphocyte stimulator, is a ligand required for the generation and maintenance of B lymphocytes. In this study, the ability of different monoclonal antibodies to recognize, inhibit, or activate mouse BAFF was investigated. One of them, a mouse IgG1 named Sandy-2, prevented the binding of BAFF to all of its receptors, BAFF receptor, transmembrane activator and calcium modulating ligand interactor, and B cell maturation antigen, at a stoichiometric ratio; blocked the activity of mouse BAFF on a variety of cell-based reporter assays; and antagonized the prosurvival action of BAFF on primary mouse B cells in vitro A single administration of Sandy-2 in mice induced B cell depletion within 2 weeks, down to levels close to those observed in BAFF-deficient mice. This depletion could then be maintained with a chronic treatment. Sandy-2 and a previously described rat IgG1 antibody, 5A8, also formed a pair suitable for the sensitive detection of endogenous circulating BAFF by ELISA or using a homogenous assay. Interestingly, 5A8 and Sandy-5 displayed activities opposite to that of Sandy-2 by stimulating recombinant BAFF in vitro and endogenous BAFF in vivo These tools will prove useful for the detection and functional manipulation of endogenous mouse BAFF and provide an alternative to the widely used BAFF receptor-Fc decoy receptor for the specific depletion of BAFF in mice. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...... includes multipoint intermolecular interactions that probably involve aggregation of both polymorphic and monomorphic T cell surface molecules. Such aggregations have been shown in vitro to markedly enhance and, in some cases, induce T cell activation. The production of T-derived lymphokines that have been...... implicated in B cell activation is dependent on the T cell receptor for antigen and its associated CD3 signalling complex. T-dependent help for B cell activation is therefore similarly MHC-restricted and involves T-B intercellular interaction. Recent reports that describe antigen-independent B cell...

  16. Microenvironment-Centred Dynamics in Aggressive B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Matilde Cacciatore

    2012-01-01

    Full Text Available Aggressive B-cell lymphomas share high proliferative and invasive attitudes and dismal prognosis despite heterogeneous biological features. In the interchained sequence of events leading to cancer progression, neoplastic clone-intrinsic molecular events play a major role. Nevertheless, microenvironment-related cues have progressively come into focus as true determinants for this process. The cancer-associated microenvironment is a complex network of nonneoplastic immune and stromal cells embedded in extracellular components, giving rise to a multifarious crosstalk with neoplastic cells towards the induction of a supportive milieu. The immunological and stromal microenvironments have been classically regarded as essential partners of indolent lymphomas, while considered mainly negligible in the setting of aggressive B-cell lymphomas that, by their nature, are less reliant on external stimuli. By this paper we try to delineate the cardinal microenvironment-centred dynamics exerting an influence over lymphoid clone progression in aggressive B-cell lymphomas.

  17. The role of B cells in systemic sclerosis

    Directory of Open Access Journals (Sweden)

    Marina D Kraaij

    2008-09-01

    Full Text Available Marina D Kraaij, Jacob M van LaarMusculoskeletal Research Group, Institute of Cellular Medicine, School of Clinical Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United KingdomAbstract: Systemic sclerosis (SSc is a connective disease characterized by features of autoimmunity, vasculopathy, inflammation, and fibrosis. The disease typically starts with Raynaud’s phenomenon, followed by skin thickening in the extremities due to inflammation and fibrosis. Fibrosis results from excessive collagen production by fibroblasts, which constitutes the final common pathway of complex cellular interactions including B cells. Several studies have indicated that B cells may play a role in SSc. Lesional skin infiltrates from SSc patients consist of a variety of cells, including eosinophils, neutrophils, lymphocytes, plasma cells, and macrophages. Autoantibodies of several specificities are present in the serum of SSc patients of which antitopoisomerase 1 is the most common, and evidence has been gathered for a potential pathogenic role of some autoantibodies, eg, anti-PDGF antibodies. The blood of SSc patients contains an increased proportion of naïve B cells but a decreased proportion of memory B cells. Furthermore, serum levels of interleukin-6, an important pro-inflammatory cytokine, have been shown to correlate with skin fibrosis. Animal models of SSc have provided more in-depth information on the role of B lymphocytes, eg, through disruption of B cell function. In this review we will discuss the evidence that B cells are involved in the pathogenesis of SSc.Keywords: B lymphocyte, systemic sclerosis, fibrosis

  18. MicroRNA-126-mediated control of cell fate in B-cell myeloid progenitors as a potential alternative to transcriptional factors.

    Science.gov (United States)

    Okuyama, Kazuki; Ikawa, Tomokatsu; Gentner, Bernhard; Hozumi, Katsuto; Harnprasopwat, Ratanakanit; Lu, Jun; Yamashita, Riu; Ha, Daon; Toyoshima, Takae; Chanda, Bidisha; Kawamata, Toyotaka; Yokoyama, Kazuaki; Wang, Shusheng; Ando, Kiyoshi; Lodish, Harvey F; Tojo, Arinobu; Kawamoto, Hiroshi; Kotani, Ai

    2013-08-13

    Lineage specification is thought to be largely regulated at the level of transcription, where lineage-specific transcription factors drive specific cell fates. MicroRNAs (miR), vital to many cell functions, act posttranscriptionally to decrease the expression of target mRNAs. MLL-AF4 acute lymphocytic leukemia exhibits both myeloid and B-cell surface markers, suggesting that the transformed cells are B-cell myeloid progenitor cells. Through gain- and loss-of-function experiments, we demonstrated that microRNA 126 (miR-126) drives B-cell myeloid biphenotypic leukemia differentiation toward B cells without changing expression of E2A immunoglobulin enhancer-binding factor E12/E47 (E2A), early B-cell factor 1 (EBF1), or paired box protein 5, which are critical transcription factors in B-lymphopoiesis. Similar induction of B-cell differentiation by miR-126 was observed in normal hematopoietic cells in vitro and in vivo in uncommitted murine c-Kit(+)Sca1(+)Lineage(-) cells, with insulin regulatory subunit-1 acting as a target of miR-126. Importantly, in EBF1-deficient hematopoietic progenitor cells, which fail to differentiate into B cells, miR-126 significantly up-regulated B220, and induced the expression of B-cell genes, including recombination activating genes-1/2 and CD79a/b. These data suggest that miR-126 can at least partly rescue B-cell development independently of EBF1. These experiments show that miR-126 regulates myeloid vs. B-cell fate through an alternative machinery, establishing the critical role of miRNAs in the lineage specification of multipotent mammalian cells.

  19. IgM and IgD B cell receptors differentially respond to endogenous antigens and control B cell fate

    Science.gov (United States)

    Noviski, Mark; Mueller, James L; Satterthwaite, Anne; Garrett-Sinha, Lee Ann; Brombacher, Frank

    2018-01-01

    Naive B cells co-express two BCR isotypes, IgM and IgD, with identical antigen-binding domains but distinct constant regions. IgM but not IgD is downregulated on autoreactive B cells. Because these isotypes are presumed to be redundant, it is unknown how this could impose tolerance. We introduced the Nur77-eGFP reporter of BCR signaling into mice that express each BCR isotype alone. Despite signaling strongly in vitro, IgD is less sensitive than IgM to endogenous antigen in vivo and developmental fate decisions are skewed accordingly. IgD-only Lyn−/− B cells cannot generate autoantibodies and short-lived plasma cells (SLPCs) in vivo, a fate thought to be driven by intense BCR signaling induced by endogenous antigens. Similarly, IgD-only B cells generate normal germinal center, but impaired IgG1+ SLPC responses to T-dependent immunization. We propose a role for IgD in maintaining the quiescence of autoreactive B cells and restricting their differentiation into autoantibody secreting cells. PMID:29521626

  20. Primary Mediastinal Large B-cell Lymphoma Exhibiting Endobronchial Involvement.

    Science.gov (United States)

    Shimada, Midori; Fukuda, Minoru; Horio, Kensuke; Suyama, Takayuki; Kitazaki, Takeshi; Hashiguchi, Kohji; Fukuda, Masaaki; Shigematsu, Kazuto; Nakamura, Yoichi; Honda, Takuya; Ashizawa, Kazuto; Mukae, Hiroshi

    Primary mediastinal large B-cell lymphoma (PMLBCL) is one of the subtypes of diffuse large B-cell lymphoma. We experienced a rare case of PMLBCL that exhibited endobronchial involvement. A 33-year-old Japanese female with the chief complaints of epigastralgia, back pain, and nausea visited a primary care hospital. Computed tomography of the chest and abdomen demonstrated a bulky mass in the left anterior mediastinum, multiple pulmonary nodules, axillary lymph node swelling, and a pancreatic tumor. Fiberoptic bronchoscopy showed a white-tinged irregularly shaped endobronchial tumor accompanied by capillary vessel dilation in the left upper lobar bronchus. Taken together, these findings resulted in a diagnosis of PMLBCL.

  1. A Literature Revision in Primary Cutaneous B-cell Lymphoma.

    Science.gov (United States)

    Selva, R La; Violetti, S Alberti; Delfino, C; Grandi, V; Cicchelli, S; Tomasini, C; Fierro, M T; Berti, E; Pimpinelli, N; Quaglino, P

    2017-01-01

    The term "Primary Cutaneous B-Cell Lymphoma" (PCBCL) comprehends a variety of lymphoproliferative disorders characterized by a clonal proliferation of B-cells primarily involving the skin. The absence of evident extra-cutaneous disease must be confirmed after six-month follow-up in order to exclude a nodal non-Hodgkin's lymphoma (NHL) with secondary cutaneous involvement, which may have a completely different clinical behavior and prognosis. In this article, we have summarized the clinico-pathological features of main types of PCBCL and we outline the guidelines for management based on a review of the available literature.

  2. Reprogramming of B cells into macrophages: mechanistic insights

    OpenAIRE

    Di Tullio, Alessandro, 1982-

    2012-01-01

    Our earlier work has shown that pre-B cells can be converted into macrophages by the transcription factor C/EBPα at very high frequencies and also that a clonal pre-B cell line with an inducible form of C/EBPα can be converted into macrophage-like cells. Using these systems we have performed a systematic analysis of the questions whether during transdifferentiation the cells retrodifferentiate to a precursor cell state and whether cell cycle is required for reprogramming. As for the first ...

  3. Essential role of EBF1 in the generation and function of distinct mature B cell types

    OpenAIRE

    Vilagos, Bojan; Hoffmann, Mareike; Souabni, Abdallah; Sun, Qiong; Werner, Barbara; Medvedovic, Jasna; Bilic, Ivan; Minnich, Martina; Axelsson, Elin; Jaritz, Markus; Busslinger, Meinrad

    2012-01-01

    The transcription factor EBF1 is essential for lineage specification in early B cell development. In this study, we demonstrate by conditional mutagenesis that EBF1 is required for B cell commitment, pro–B cell development, and subsequent transition to the pre–B cell stage. Later in B cell development, EBF1 was essential for the generation and maintenance of several mature B cell types. Marginal zone and B-1 B cells were lost, whereas follicular (FO) and germinal center (GC) B cells were redu...

  4. Integrating genomic alterations in diffuse large B-cell lymphoma identifies new relevant pathways and potential therapeutic targets

    Science.gov (United States)

    Karube, K; Enjuanes, A; Dlouhy, I; Jares, P; Martin-Garcia, D; Nadeu, F; Ordóñez, G R; Rovira, J; Clot, G; Royo, C; Navarro, A; Gonzalez-Farre, B; Vaghefi, A; Castellano, G; Rubio-Perez, C; Tamborero, D; Briones, J; Salar, A; Sancho, J M; Mercadal, S; Gonzalez-Barca, E; Escoda, L; Miyoshi, H; Ohshima, K; Miyawaki, K; Kato, K; Akashi, K; Mozos, A; Colomo, L; Alcoceba, M; Valera, A; Carrió, A; Costa, D; Lopez-Bigas, N; Schmitz, R; Staudt, L M; Salaverria, I; López-Guillermo, A; Campo, E

    2018-01-01

    Genome studies of diffuse large B-cell lymphoma (DLBCL) have revealed a large number of somatic mutations and structural alterations. However, the clinical significance of these alterations is still not well defined. In this study, we have integrated the analysis of targeted next-generation sequencing of 106 genes and genomic copy number alterations (CNA) in 150 DLBCL. The clinically significant findings were validated in an independent cohort of 111 patients. Germinal center B-cell and activated B-cell DLBCL had a differential profile of mutations, altered pathogenic pathways and CNA. Mutations in genes of the NOTCH pathway and tumor suppressor genes (TP53/CDKN2A), but not individual genes, conferred an unfavorable prognosis, confirmed in the independent validation cohort. A gene expression profiling analysis showed that tumors with NOTCH pathway mutations had a significant modulation of downstream target genes, emphasizing the relevance of this pathway in DLBCL. An in silico drug discovery analysis recognized 69 (46%) cases carrying at least one genomic alteration considered a potential target of drug response according to early clinical trials or preclinical assays in DLBCL or other lymphomas. In conclusion, this study identifies relevant pathways and mutated genes in DLBCL and recognizes potential targets for new intervention strategies. PMID:28804123

  5. Tracheal ulcer due to Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly.

    Science.gov (United States)

    Ito, Takeo; Fujisaki, Hideaki; Nishio, Suehiro; Hiroshige, Shigeo; Miyazaki, Eishi; Kadota, Jun-ichi

    2014-03-01

    A 74-year-old man was referred to our hospital because of a tracheal stenosis circumscribed with soft tissue density and a left pulmonary nodule. Open biopsy of a right submandibular lymph node revealed diffuse large B-cell lymphoma, and the malignant cells were positive for Epstein-Barr virus gene products. Bronchofiberscopy revealed a tracheal necrotizing ulcer. After chemotherapy, the tracheal ulcer resolved. To our knowledge, this is the first report of a case of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly with a tracheal ulcer. © 2013 Published by The Japanese Respiratory Society on behalf of The Japanese Respiratory Society.

  6. A human B cell methylome at 100−base pair resolution

    Science.gov (United States)

    Rauch, Tibor A.; Wu, Xiwei; Zhong, Xueyan; Riggs, Arthur D.; Pfeifer, Gerd P.

    2009-01-01

    Using a methylated-DNA enrichment technique (methylated CpG island recovery assay, MIRA) in combination with whole-genome tiling arrays, we have characterized by MIRA-chip the entire B cell “methylome” of an individual human at 100-bp resolution. We find that at the chromosome level high CpG methylation density is correlated with subtelomeric regions and Giemsa-light bands (R bands). The majority of the most highly methylated regions that could be identified on the tiling arrays were associated with genes. Approximately 10% of all promoters in B cells were found to be methylated, and this methylation correlates with low gene expression. Notably, apparent exceptions to this correlation were the result of transcription from previously unidentified, unmethylated transcription start sites, suggesting that methylation may control alternate promoter usage. Methylation of intragenic (gene body) sequences was found to correlate with increased, not decreased, transcription, and a methylated region near the 3′ end was found in approximately 12% of all genes. The majority of broad regions (10–44 kb) of high methylation were at segmental duplications. Our data provide a valuable resource for the analysis of CpG methylation patterns in a differentiated human cell type and provide new clues regarding the function of mammalian DNA methylation. PMID:19139413

  7. The transcription repressors Bach2 and Bach1 promote B cell development by repressing the myeloid program.

    Science.gov (United States)

    Itoh-Nakadai, Ari; Hikota, Reina; Muto, Akihiko; Kometani, Kohei; Watanabe-Matsui, Miki; Sato, Yuki; Kobayashi, Masahiro; Nakamura, Atsushi; Miura, Yuichi; Yano, Yoko; Tashiro, Satoshi; Sun, Jiying; Ikawa, Tomokatsu; Ochiai, Kyoko; Kurosaki, Tomohiro; Igarashi, Kazuhiko

    2014-12-01

    Mature lymphoid cells express the transcription repressor Bach2, which imposes regulation on humoral and cellular immunity. Here we found critical roles for Bach2 in the development of cells of the B lineage, commencing from the common lymphoid progenitor (CLP) stage, with Bach1 as an auxiliary. Overexpression of Bach2 in pre-pro-B cells deficient in the transcription factor EBF1 and single-cell analysis of CLPs revealed that Bach2 and Bach1 repressed the expression of genes important for myeloid cells ('myeloid genes'). Bach2 and Bach1 bound to presumptive regulatory regions of the myeloid genes. Bach2(hi) CLPs showed resistance to myeloid differentiation even when cultured under myeloid conditions. Our results suggest that Bach2 functions with Bach1 and EBF1 to promote B cell development by repressing myeloid genes in CLPs.

  8. Atypical memory B cells in human chronic infectious diseases: An interim report.

    Science.gov (United States)

    Portugal, Silvia; Obeng-Adjei, Nyamekye; Moir, Susan; Crompton, Peter D; Pierce, Susan K

    2017-11-01

    Immunological memory is a remarkable phenomenon in which survival of an initial infection by a pathogen leads to life-long protection from disease upon subsequent exposure to that same pathogen. For many infectious diseases, long-lived protective humoral immunity is induced after only a single infection in a process that depends on the generation of memory B cells (MBCs) and long-lived plasma cells. However, over the past decade it has become increasingly evident that many chronic human infectious diseases to which immunity is not readily established, including HIV-AIDS, malaria and TB, are associated with fundamental alterations in the composition and functionality of MBC compartments. A common feature of these diseases appears to be a large expansion of what have been termed exhausted B cells, tissue-like memory B cells or atypical memory B cells (aMBCs) that, for simplicity's sake, we refer to here as aMBCs. It has been suggested that chronic immune activation and inflammation drive the expansion of aMBCs and that in some way aMBCs contribute to deficiencies in the acquisition of immunity in chronic infectious diseases. Although aMBCs are heterogeneous both within individuals and between diseases, they have several features in common including low expression of the cell surface markers that define classical MBCs in humans including CD21 and CD27 and high expression of genes not usually expressed by classical MBCs including T-bet, CD11c and a variety of inhibitory receptors, notably members of the FcRL family. Another distinguishing feature is their greatly diminished ability to be stimulated through their B cell receptors to proliferate, secrete cytokines or produce antibodies. In this review, we describe our current understanding of the phenotypic markers of aMBCs, their specificity in relation to the disease-causing pathogen, their functionality, the drivers of their expansion in chronic infections and their life span. We briefly summarize the features of a

  9. Macrophage colony-stimulating factor receptor marks and regulates a fetal myeloid-primed B-cell progenitor in mice.

    Science.gov (United States)

    Zriwil, Alya; Böiers, Charlotta; Wittmann, Lilian; Green, Joanna C A; Woll, Petter S; Jacobsen, Sten Eirik W; Sitnicka, Ewa

    2016-07-14

    Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19(+) B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R(+)CD19(+) ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R(+) myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R(+) myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported. © 2016 by The American Society of Hematology.

  10. Anti-HIV-1 B cell responses are dependent on B cell precursor frequency and antigen-binding affinity.

    Science.gov (United States)

    Dosenovic, Pia; Kara, Ervin E; Pettersson, Anna-Klara; McGuire, Andrew T; Gray, Matthew; Hartweger, Harald; Thientosapol, Eddy S; Stamatatos, Leonidas; Nussenzweig, Michel C

    2018-04-16

    The discovery that humans can produce potent broadly neutralizing antibodies (bNAbs) to several different epitopes on the HIV-1 spike has reinvigorated efforts to develop an antibody-based HIV-1 vaccine. Antibody cloning from single cells revealed that nearly all bNAbs show unusual features that could help explain why it has not been possible to elicit them by traditional vaccination and instead would require a sequence of different immunogens. This idea is supported by experiments with genetically modified immunoglobulin (Ig) knock-in mice. Sequential immunization with a series of specifically designed immunogens was required to shepherd the development of bNAbs. However, knock-in mice contain superphysiologic numbers of bNAb precursor-expressing B cells, and therefore how these results can be translated to a more physiologic setting remains to be determined. Here we make use of adoptive transfer experiments using knock-in B cells that carry a synthetic intermediate in the pathway to anti-HIV-1 bNAb development to examine how the relationship between B cell receptor affinity and precursor frequency affects germinal center (GC) B cell recruitment and clonal expansion. Immunization with soluble HIV-1 antigens can recruit bNAb precursor B cells to the GC when there are as few as 10 such cells per mouse. However, at low precursor frequencies, the extent of clonal expansion is directly proportional to the affinity of the antigen for the B cell receptor, and recruitment to GCs is variable and dependent on recirculation.

  11. Sequential development of peripheral t-cell lymphoma post immunochemotherapy of diffuse large B cell lymphoma.

    Science.gov (United States)

    Wang, Jing-Wen; Chen, Jia-Yan; Lu, Chen; Tang, Xi

    2017-04-03

    Reports of sequential occurrence of two or more types of lymphoma are rare, especially when they involve different cell lineages. Herein, we report a rare case of sequential development of peripheral t-cell lymphoma following treatment of diffuse large B cell lymphoma. In a 73-year-old Chinese male patient, diffuse large B-cell lymphoma (DLBCL) was diagnosed in September 2011 based on the result of a tongue biopsy. Afterwards, he received rituximab combined with chemotherapy and local radiotherapy. Though he achieved completed remission, he had a new symptom of one enlarged left inguinal lymph node in November of 2015. A new biopsy was then performed. Immunohistochemistry and polymerase chain reaction (PCR) for gene rearrangements proved monoclonal T-cell lymphoma. We didn't detect EBV infection in either of two biopsies, nor any evidence of immune dysfunction complications. Sequential development of B-cell and T-cell malignancy in this patient maybe an example of treatment-related secondary lymphoma.

  12. Transcriptional repression of Gata3 is essential for early B cell commitment.

    Science.gov (United States)

    Banerjee, Anupam; Northrup, Daniel; Boukarabila, Hanane; Jacobsen, Sten Erik W; Allman, David

    2013-05-23

    The mechanisms underlying the silencing of alternative fate potentials in very early B cell precursors remain unclear. Using gain- and loss-of-function approaches together with a synthetic Zinc-finger polypeptide (6ZFP) engineered to prevent transcription factor binding to a defined cis element, we show that the transcription factor EBF1 promotes B cell lineage commitment by directly repressing expression of the T-cell-lineage-requisite Gata3 gene. Ebf1-deficient lymphoid progenitors exhibited increased T cell lineage potential and elevated Gata3 transcript expression, whereas enforced EBF1 expression inhibited T cell differentiation and caused rapid loss of Gata3 mRNA. Notably, 6ZFP-mediated perturbation of EBF1 binding to a Gata3 regulatory region restored Gata3 expression, abrogated EBF1-driven suppression of T cell differentiation, and prevented B cell differentiation via a GATA3-dependent mechanism. Furthermore, EBF1 binding to Gata3 regulatory sites induced repressive histone modifications across this region. These data identify a transcriptional circuit critical for B cell lineage commitment. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Targeting the BCR signalosome in B cell malignancies

    NARCIS (Netherlands)

    de Rooij, M.F.M.

    2017-01-01

    Chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenström macroglobulinemia (WM) are B-cell malignancies which are still incurable. In these lymphomas, the cells proliferate in specialized niches in lymph nodes and bone marrow, in which they are provided by stromal-derived

  14. Likelihood-Based Inference of B Cell Clonal Families.

    Directory of Open Access Journals (Sweden)

    Duncan K Ralph

    2016-10-01

    Full Text Available The human immune system depends on a highly diverse collection of antibody-making B cells. B cell receptor sequence diversity is generated by a random recombination process called "rearrangement" forming progenitor B cells, then a Darwinian process of lineage diversification and selection called "affinity maturation." The resulting receptors can be sequenced in high throughput for research and diagnostics. Such a collection of sequences contains a mixture of various lineages, each of which may be quite numerous, or may consist of only a single member. As a step to understanding the process and result of this diversification, one may wish to reconstruct lineage membership, i.e. to cluster sampled sequences according to which came from the same rearrangement events. We call this clustering problem "clonal family inference." In this paper we describe and validate a likelihood-based framework for clonal family inference based on a multi-hidden Markov Model (multi-HMM framework for B cell receptor sequences. We describe an agglomerative algorithm to find a maximum likelihood clustering, two approximate algorithms with various trade-offs of speed versus accuracy, and a third, fast algorithm for finding specific lineages. We show that under simulation these algorithms greatly improve upon existing clonal family inference methods, and that they also give significantly different clusters than previous methods when applied to two real data sets.

  15. Th1 and Th2 help for B cells

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1995-01-01

    Sustained interaction with Th1 cells has been shown to induce IL-2 responsiveness by murine B cells. This is equivalently dependent on CD40, CD54/ICAM-1 and MHC II ligation, and co-cross-linking of CD54 and MHC II in the presence of IL-5 up-regulates a functional IL-2R on B cells. We now show...... that IL-5 (125 U/ml) synergizes with Th1 cells to induce B cell responses to IL-2, that are maintained following T-cell removal, e.g. autonomous. Th1 help in the absence of IL-5 resulted in weak or undetectable responses following T cell removal. The mechanism of IL-5 synergy involved persistence of IL-2R...... anti-Ig did not circumvent the need for IL-5 for autonomous IL-2 responses. Consistent with the above, interaction with an IL-5-producing Th2 clone induced strong autonomous B cell responses to IL-2. Qualitative differences of Th2 help over that of Th1 may thus be attributable to their differential...

  16. Role of Bruton's tyrosine kinase in B cells and malignancies

    NARCIS (Netherlands)

    Pal Singh, S. (Simar); F. Dammeijer (Floris); R.W. Hendriks (Rudi)

    2018-01-01

    textabstractBruton's tyrosine kinase (BTK) is a non-receptor kinase that plays a crucial role in oncogenic signaling that is critical for proliferation and survival of leukemic cells in many B cell malignancies. BTK was initially shown to be defective in the primary immunodeficiency X-linked

  17. Lymphoma classification update: B-cell non-Hodgkin lymphomas.

    Science.gov (United States)

    Jiang, Manli; Bennani, N Nora; Feldman, Andrew L

    2017-05-01

    Lymphomas are classified based on the normal counterpart, or cell of origin, from which they arise. Because lymphocytes have physiologic immune functions that vary both by lineage and by stage of differentiation, the classification of lymphomas arising from these normal lymphoid populations is complex. Recent genomic data have contributed additional complexity. Areas covered: Lymphoma classification follows the World Health Organization (WHO) system, which reflects international consensus and is based on pathological, genetic, and clinical factors. A 2016 revision to the WHO classification of lymphoid neoplasms recently was reported. The present review focuses on B-cell non-Hodgkin lymphomas, the most common group of lymphomas, and summarizes recent changes most relevant to hematologists and other clinicians who care for lymphoma patients. Expert commentary: Lymphoma classification is a continually evolving field that needs to be responsive to new clinical, pathological, and molecular understanding of lymphoid neoplasia. Among the entities covered in this review, the 2016 revision of the WHO classification particularly impact the subclassification and genetic stratification of diffuse large B-cell lymphoma and high-grade B-cell lymphomas, and reflect evolving criteria and nomenclature for indolent B-cell lymphomas and lymphoproliferative disorders.

  18. Immunomodulatory effect of Mesenchymal Stem Cells on B cells

    Directory of Open Access Journals (Sweden)

    Marcella eFranquesa

    2012-07-01

    Full Text Available The research on T cell immunosuppression therapies has attracted most of the attention in clinical transplantation. However, B cells and humoral immune responses are increasingly acknowledged as crucial mediators of chronic allograft rejection. Indeed, humoral immune responses can lead to renal allograft rejection even in patients whose cell-mediated immune responses are well controlled. On the other hand, newly studied B cell subsets with regulatory effects have been linked to tolerance achievement in transplantation. Better understanding of the regulatory and effector B cell responses may therefore lead to new therapeutic approaches.Mesenchymal Stem Cells (MSC are arising as a potent therapeutic tool in transplantation due to their regenerative and immunomodulatory properties. The research on MSCs has mainly focused on their effects on T cells and although data regarding the modulatory effects of MSCs on alloantigen-specific humoral response in humans is scarce, it has been demonstrated that MSCs significantly affect B cell functioning. In the present review we will analyze and discuss the results in this field.

  19. Prognostic significance of metallothionein in B-cell lymphomas

    DEFF Research Database (Denmark)

    Poulsen, Christian Bjørn; Borup, Rehannah; Borregaard, Niels

    2006-01-01

    We have investigated metallothionein (MT) I and II mRNA and protein in B-cell lymphomas with particular reference to diffuse large B-cell lymphoma (DLBCL). The mRNA profiling was performed on Affymetrix arrays and showed up-regulated MT mRNA in 15 of 48 DLBCLs, including 12 of 23 activated B......-cell (ABC) and 3 of 9 type-3 lesions. In contrast, MT mRNA was low to undetectable in 16 germinal center B-cell (GCB)-type DLBCLs. Only 1 of 15 patients with up-regulated MT mRNA achieved a sustained remission, suggesting that up-regulated MT mRNA constitutes a significant risk factor for treatment failure......, in 115 DLBCLs, MT labeling of more than 20% lymphoma cells was associated with a significantly poorer 5-year survival, independent of the age, stage, or International Prognostic Index. Taken together, it is suggested that both increased MT mRNA and MT protein expression by more than 20% lymphoma cells...

  20. Anthropometrics and prognosis in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Bendtsen, Mette Dahl; Munksgaard, Peter Svenssen; Severinsen, Marianne Tang

    2017-01-01

    Objective: The impact of body mass index (BMI) and body surface area (BSA) on survival in diffuse large B-cell lymphoma (DLBCL) is controversial. Recent studies show superior outcomes for overweight and obese patients. Patients and methods: A total of 653 R-CHOP(-like)-treated DLBCL patients were...

  1. Altered B Cell Homeostasis in Patients with Major Depressive Disorder and Normalization of CD5 Surface Expression on Regulatory B Cells in Treatment Responders.

    Science.gov (United States)

    Ahmetspahic, Diana; Schwarte, Kathrin; Ambrée, Oliver; Bürger, Christian; Falcone, Vladislava; Seiler, Katharina; Kooybaran, Mehrdad Rahbar; Grosse, Laura; Roos, Fernand; Scheffer, Julia; Jörgens, Silke; Koelkebeck, Katja; Dannlowski, Udo; Arolt, Volker; Scheu, Stefanie; Alferink, Judith

    2018-03-01

    Pro-inflammatory activity and cell-mediated immune responses have been widely observed in patients with major depressive disorder (MDD). Besides their well-known function as antibody-producers, B cells play a key role in inflammatory responses by secreting pro- and anti-inflammatory factors. However, homeostasis of specific B cell subsets has not been comprehensively investigated in MDD. In this study, we characterized circulating B cells of distinct developmental steps including transitional, naïve-mature, antigen-experienced switched, and non-switched memory cells, plasmablasts and regulatory B cells by multi-parameter flow cytometry. In a 6-weeks follow-up, circulating B cells were monitored in a small group of therapy responders and non-responders. Frequencies of naïve lgD + CD27 - B cells, but not lgD + CD27 + memory B cells, were reduced in severely depressed patients as compared to healthy donors (HD) or mildly to moderately depressed patients. Specifically, B cells with immune-regulatory capacities such as CD1d + CD5 + B cells and CD24 + CD38 hi transitional B cells were reduced in MDD. Also Bm1-Bm5 classification in MDD revealed reduced Bm2' cells comprising germinal center founder cells as well as transitional B cells. We further found that reduced CD5 surface expression on transitional B cells was associated with severe depression and normalized exclusively in clinical responders. This study demonstrates a compromised peripheral B cell compartment in MDD with a reduction in B cells exhibiting a regulatory phenotype. Recovery of CD5 surface expression on transitional B cells in clinical response, a molecule involved in activation and down-regulation of B cell responses, further points towards a B cell-dependent process in the pathogenesis of MDD.

  2. Primary B-cell deficiencies reveal a link between human IL-17-producing CD4 T-cell homeostasis and B-cell differentiation.

    Directory of Open Access Journals (Sweden)

    Rita R Barbosa

    Full Text Available IL-17 is a pro-inflammatory cytokine implicated in autoimmune and inflammatory conditions. The development/survival of IL-17-producing CD4 T cells (Th17 share critical cues with B-cell differentiation and the circulating follicular T helper subset was recently shown to be enriched in Th17 cells able to help B-cell differentiation. We investigated a putative link between Th17-cell homeostasis and B cells by studying the Th17-cell compartment in primary B-cell immunodeficiencies. Common Variable Immunodeficiency Disorders (CVID, defined by defects in B-cell differentiation into plasma and memory B cells, are frequently associated with autoimmune and inflammatory manifestations but we found no relationship between these and Th17-cell frequency. In fact, CVID patients showed a decrease in Th17-cell frequency in parallel with the expansion of activated non-differentiated B cells (CD21(lowCD38(low. Moreover, Congenital Agammaglobulinemia patients, lacking B cells due to impaired early B-cell development, had a severe reduction of circulating Th17 cells. Finally, we found a direct correlation in healthy individuals between circulating Th17-cell frequency and both switched-memory B cells and serum BAFF levels, a crucial cytokine for B-cell survival. Overall, our data support a relationship between Th17-cell homeostasis and B-cell maturation, with implications for the understanding of the pathogenesis of inflammatory/autoimmune diseases and the physiology of B-cell depleting therapies.

  3. B-cell lymphoma with Mott cell differentiation in two young adult dogs.

    Science.gov (United States)

    Stacy, Nicole I; Nabity, Mary B; Hackendahl, Nicole; Buote, Melanie; Ward, Jennifer; Ginn, Pamela E; Vernau, William; Clapp, William L; Harvey, John W

    2009-03-01

    Two young adult dogs with gastrointestinal signs were each found to have an intra-abdominal mass based on physical examination and diagnostic imaging. On exploratory laparotomy, small intestinal masses and mesenteric lymphadenopathy were found in both dogs; a liver mass was also found in dog 1. Cytologic and histologic examination of intestinal and liver masses and mesenteric lymph nodes revealed 2 distinct lymphoid cell populations: lymphoblasts and atypical Mott cells. With Romanowsky stains, the atypical Mott cells contained many discrete, clear to pale blue cytoplasmic inclusions consistent with Russell bodies that were positive by immunohistochemistry for IgM and CD79a in both dogs and for IgG in dog 2. The Mott cells and occasional lymphoblasts stained strongly positive with periodic acid-Schiff. Using flow cytometric immunophenotyping in dog 1, 60% of peripheral blood mononuclear cells and 85% of cells in an affected lymph node were positive for CD21, CD79a, IgM, and MCH II, indicative of B-cells. With electron microscopy, disorganized and dilated endoplasmic reticulum was seen in Mott cells in tumors from both dogs. Antigen receptor gene rearrangement analysis of lymph node and intestinal masses indicated a clonal B-cell population. Based on cell morphology, tissue involvement, and evidence for clonal B-cell proliferation, we diagnosed neoplasms involving Mott cells. To the authors' knowledge, this is the second report of Mott cell tumors or, more appropriately, B-cell lymphoma with Mott cell differentiation, in dogs. More complete characterization of this neoplasm requires further investigation of additional cases. This lymphoproliferative disease should be considered as a differential diagnosis for canine gastrointestinal tumors.

  4. Characteristics of memory B cells elicited by a highly efficacious HPV vaccine in subjects with no pre-existing immunity.

    Science.gov (United States)

    Scherer, Erin M; Smith, Robin A; Simonich, Cassandra A; Niyonzima, Nixon; Carter, Joseph J; Galloway, Denise A

    2014-10-01

    Licensed human papillomavirus (HPV) vaccines provide near complete protection against the types of HPV that most commonly cause anogenital and oropharyngeal cancers (HPV 16 and 18) when administered to individuals naive to these types. These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies. However, almost nothing is known about the immunological memory that forms following HPV vaccination, which is required for long-term immunity. Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells. Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation. These findings suggest that the quadrivalent HPV vaccine provides an excellent model for studying the development of B cell memory; and, in the context of what is known about memory B cells elicited by influenza vaccination/infection, HIV-1 infection, or tetanus toxoid vaccination, indicates that extensive somatic hypermutation is not required to achieve potent vaccine-specific neutralizing antibody responses.

  5. Activation-induced cytidine deaminase in B cells of hepatits C virus-related cryoglobulinaemic vasculitis.

    Science.gov (United States)

    Russi, S; Dammacco, F; Sansonno, S; Pavone, F; Sansonno, D

    2015-12-01

    Immunoglobulin variable region heavy chain (IgVH ) somatic gene diversification is instrumental in the transformation process that characterizes hepatitis C virus (HCV)-related B cell lymphoproliferative disorders. However, the extent to which activation-induced cytidine deaminase (AID), an enzyme essential for IgV gene somatic hypermutation (SHM), is active in cryoglobulinaemic vasculitis (CV) remains unclear. AID mRNA expression in the peripheral blood of 102 chronically hepatitis C virus (HCV)-infected patients (58 with and 44 without CV) and 26 healthy subjects was investigated using real-time reverse transcription-polymerase chain reaction (RT-PCR). The features of activation-induced cytidine deaminase (AID) protein and mRNA transcripts were explored in liver tissue biopsies and portal tracts isolated using laser capture microdissection. In chronically HCV-infected patients, AID mRNA expression was almost threefold higher in those with than in those without CV and sevenfold higher than in healthy subjects (median-fold: 6.68 versus 2.54, P = 0.03 and versus 0.95, P = 0.0003). AID transcript levels were significantly higher in polyclonal than in clonally restricted B cell preparations in either CV or non-CV patients (median-fold, 15.0 versus 2.70, P = 0.009 and 3.46 versus 1.58, P = 0.02, respectively). AID gene expression was found to be related negatively to age and virological parameters. AID protein was found in portal tracts containing inflammatory cells that, in several instances, expressed AID mRNA transcripts. Our data indicate that the aberrant expression of AID may reflect continuous B cell activation and sustained survival signals in HCV-related CV patients. © 2015 British Society for Immunology.

  6. Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Shao-Qing Kuang

    Full Text Available The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL. We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

  7. Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Kuang, Shao-Qing; Fang, Zhihong; Zweidler-McKay, Patrick A; Yang, Hui; Wei, Yue; Gonzalez-Cervantes, Emilio A; Boumber, Yanis; Garcia-Manero, Guillermo

    2013-01-01

    The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA)/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL). We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

  8. MicroRNAs link the Germinal Center reaction and B cell lymphomagenesis

    OpenAIRE

    Bartolomé Izquierdo, Nahikari

    2016-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 01-04-2016 Esta tesis tiene embargado el acceso al texto completo hasta el 01-10-2017 Germinal centers (GC) are microstructures where B cells that have been activated by antigen undergo a developmental program that involves the somatic diversification of their immunoglobulin genes and intense proliferative activity coupled to apoptotic selective ev...

  9. High Inter-Individual Diversity of Point Mutations, Insertions, and Deletions in Human Influenza Virus Nucleoprotein-Specific Memory B Cells.

    Directory of Open Access Journals (Sweden)

    Sven Reiche

    Full Text Available The diversity of virus-specific antibodies and of B cells among different individuals is unknown. Using single-cell cloning of antibody genes, we generated recombinant human monoclonal antibodies from influenza nucleoprotein-specific memory B cells in four adult humans with and without preceding influenza vaccination. We examined the diversity of the antibody repertoires and found that NP-specific B cells used numerous immunoglobulin genes. The heavy chains (HCs originated from 26 and the kappa light chains (LCs from 19 different germ line genes. Matching HC and LC chains gave rise to 43 genetically distinct antibodies that bound influenza NP. The median lengths of the CDR3 of the HC, kappa and lambda LC were 14, 9 and 11 amino acids, respectively. We identified changes at 13.6% of the amino acid positions in the V gene of the antibody heavy chain, at 8.4% in the kappa and at 10.6 % in the lambda V gene. We identified somatic insertions or deletions in 8.1% of the variable genes. We also found several small groups of clonal relatives that were highly diversified. Our findings demonstrate broadly diverse memory B cell repertoires for the influenza nucleoprotein. We found extensive variation within individuals with a high number of point mutations, insertions, and deletions, and extensive clonal diversification. Thus, structurally conserved proteins can elicit broadly diverse and highly mutated B-cell responses.

  10. Type I CD20 Antibodies Recruit the B Cell Receptor for Complement-Dependent Lysis of Malignant B Cells

    NARCIS (Netherlands)

    Engelberts, Patrick J.; Voorhorst, Marleen; Schuurman, Janine; van Meerten, Tom; Bakker, Joost M.; Vink, Tom; Mackus, Wendy J. M.; Breij, Esther C. W.; Derer, Stefanie; Valerius, Thomas; van de Winkel, Jan G. J.; Parren, Paul W. H. I.; Beurskens, Frank J.

    2016-01-01

    Human IgG1 type I CD20 Abs, such as rituximab and ofatumumab (OFA), efficiently induce complement-dependent cytotoxicity (CDC) of CD20(+) B cells by binding of C1 to hexamerized Fc domains. Unexpectedly, we found that type I CD20 Ab F(ab ')2 fragments, as well as C1q-binding-deficient IgG mutants,

  11. Development Refractoriness of MLL-Rearranged Human B Cell Acute Leukemias to Reprogramming into Pluripotency

    Directory of Open Access Journals (Sweden)

    Alvaro Muñoz-López

    2016-10-01

    Full Text Available Induced pluripotent stem cells (iPSCs are a powerful tool for disease modeling. They are routinely generated from healthy donors and patients from multiple cell types at different developmental stages. However, reprogramming leukemias is an extremely inefficient process. Few studies generated iPSCs from primary chronic myeloid leukemias, but iPSC generation from acute myeloid or lymphoid leukemias (ALL has not been achieved. We attempted to generate iPSCs from different subtypes of B-ALL to address the developmental impact of leukemic fusion genes. OKSM(L-expressing mono/polycistronic-, retroviral/lentiviral/episomal-, and Sendai virus vector-based reprogramming strategies failed to render iPSCs in vitro and in vivo. Addition of transcriptomic-epigenetic reprogramming “boosters” also failed to generate iPSCs from B cell blasts and B-ALL lines, and when iPSCs emerged they lacked leukemic fusion genes, demonstrating non-leukemic myeloid origin. Conversely, MLL-AF4-overexpressing hematopoietic stem cells/B progenitors were successfully reprogrammed, indicating that B cell origin and leukemic fusion gene were not reprogramming barriers. Global transcriptome/DNA methylome profiling suggested a developmental/differentiation refractoriness of MLL-rearranged B-ALL to reprogramming into pluripotency.

  12. Hepatocyte Nuclear Factor 1A Is a Cell-Intrinsic Transcription Factor Required for B Cell Differentiation and Development in Mice.

    Science.gov (United States)

    von Wnuck Lipinski, Karin; Sattler, Katherine; Peters, Susann; Weske, Sarah; Keul, Petra; Klump, Hannes; Heusch, Gerd; Göthert, Joachim R; Levkau, Bodo

    2016-02-15

    The hepatocyte NF (HNF) family of transcription factors regulates the complex gene networks involved in lipid, carbohydrate, and protein metabolism. In humans, HNF1A mutations cause maturity onset of diabetes in the young type 3, whereas murine HNF6 participates in fetal liver B lymphopoiesis. In this study, we have identified a crucial role for the prototypical member of the family HNF1A in adult bone marrow B lymphopoiesis. HNF1A(-/-) mice exhibited a clear reduction in total blood and splenic B cells and a further pronounced one in transitional B cells. In HNF1A(-/-) bone marrow, all B cell progenitors-from pre-pro-/early pro-B cells to immature B cells-were dramatically reduced and their proliferation rate suppressed. IL-7 administration in vivo failed to boost B cell development in HNF1A(-/-) mice, whereas IL-7 stimulation of HNF1A(-/-) B cell progenitors in vitro revealed a marked impairment in STAT5 phosphorylation. The B cell differentiation potential of HNF1A(-/-) common lymphoid progenitors was severely impaired in vitro, and the expression of the B lymphopoiesis-promoting transcription factors E2A, EBF1, Pax5, and Bach2 was reduced in B cell progenitors in vivo. HNF1A(-/-) bone marrow chimera featured a dramatic defect in B lymphopoiesis recapitulating that of global HNF1A deficiency. The HNF1A(-/-) lymphopoiesis defect was confined to B cells as T lymphopoiesis was unaffected, and bone marrow common lymphoid progenitors and hematopoietic stem cells were even increased. Our data demonstrate that HNF1A is an important cell-intrinsic transcription factor in adult B lymphopoiesis and suggest the IL-7R/STAT5 module to be causally involved in mediating its function. Copyright © 2016 by The American Association of Immunologists, Inc.

  13. Assessment of CD37 B-cell antigen and cell of origin significantly improves risk prediction in diffuse large B-cell lymphoma

    NARCIS (Netherlands)

    Xu-Monette, Z.Y.; Li, L; Byrd, J.C.; Jabbar, K.J.; Manyam, G.C.; Winde, C. Maria de; Brand, M. van den; Tzankov, A.; Visco, C.; Wang, J; Dybkaer, K.; Chiu, A.; Orazi, A.; Zu, Y.; Bhagat, G.; Richards, K.L.; Hsi, E.D.; Choi, W.W.; Huh, J.; Ponzoni, M.; Ferreri, A.J.; Moller, M.B.; Parsons, B.M.; Winter, J.N.; Wang, M.; Hagemeister, F.B.; Piris, M.A.; Krieken, J.H. van; Medeiros, L.J.; Li, Y.; Spriel, A.B. van; Young, K.H.

    2016-01-01

    CD37 (tetraspanin TSPAN26) is a B-cell surface antigen widely expressed on mature B cells. CD37 is involved in immune regulation and tumor suppression but its function has not been fully elucidated. We assessed CD37 expression in de novo diffuse large B-cell lymphoma (DLBCL), and investigated its

  14. The B cell antigen receptor and overexpression of MYC can cooperate in the genesis of B cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yosef Refaeli

    2008-06-01

    Full Text Available A variety of circumstantial evidence from humans has implicated the B cell antigen receptor (BCR in the genesis of B cell lymphomas. We generated mouse models designed to test this possibility directly, and we found that both the constitutive and antigen-stimulated state of a clonal BCR affected the rate and outcome of lymphomagenesis initiated by the proto-oncogene MYC. The tumors that arose in the presence of constitutive BCR differed from those initiated by MYC alone and resembled chronic B cell lymphocytic leukemia/lymphoma (B-CLL, whereas those that arose in response to antigen stimulation resembled large B-cell lymphomas, particularly Burkitt lymphoma (BL. We linked the genesis of the BL-like tumors to antigen stimulus in three ways. First, in reconstruction experiments, stimulation of B cells by an autoantigen in the presence of overexpressed MYC gave rise to BL-like tumors that were, in turn, dependent on both MYC and the antigen for survival and proliferation. Second, genetic disruption of the pathway that mediates signaling from the BCR promptly killed cells of the BL-like tumors as well as the tumors resembling B-CLL. And third, growth of the murine BL could be inhibited by any of three distinctive immunosuppressants, in accord with the dependence of the tumors on antigen-induced signaling. Together, our results provide direct evidence that antigenic stimulation can participate in lymphomagenesis, point to a potential role for the constitutive BCR as well, and sustain the view that the constitutive BCR gives rise to signals different from those elicited by antigen. The mouse models described here should be useful in exploring further the pathogenesis of lymphomas, and in preclinical testing of new therapeutics.

  15. MicroRNA-125b-1 and BLID upregulation resulting from a novel IGH translocation in childhood B-Cell precursor acute lymphoblastic leukemia.

    Science.gov (United States)

    Tassano, Elisa; Acquila, Maura; Tavella, Elisa; Micalizzi, Concetta; Panarello, Claudio; Morerio, Cristina

    2010-08-01

    Chromosomal translocations involving the immunoglobulin heavy chain (IGH) locus are common abnormalities in mature B-cell neoplasms. Recent findings have also revealed their significant role in B-cell precursor acute lymphoblastic leukemia. As a rule, IGH translocations generate transcriptional activation of the oncogene localized in the proximity of the breakpoint. In this study, we describe a pediatric case of B-cell precursor acute lymphoblastic leukemia showing microRNA-125b-1 (MIR125B1) and BLID gene overexpression, resulting from a novel t(11;14)(q24.1;q32) translocation involving IGH. This is the first report describing the upregulation of a microRNA due to its juxtaposition to protein-coding gene regulatory elements and the overexpression of two neighboring genes as a consequence of transcriptional enhancers localized in the vicinity of the IGH gene.

  16. Systems Analysis Reveals High Genetic and Antigen-Driven Predetermination of Antibody Repertoires throughout B Cell Development

    Directory of Open Access Journals (Sweden)

    Victor Greiff

    2017-05-01

    Full Text Available Antibody repertoire diversity and plasticity is crucial for broad protective immunity. Repertoires change in size and diversity across multiple B cell developmental stages and in response to antigen exposure. However, we still lack fundamental quantitative understanding of the extent to which repertoire diversity is predetermined. Therefore, we implemented a systems immunology framework for quantifying repertoire predetermination on three distinct levels: (1 B cell development (pre-B cell, naive B cell, plasma cell, (2 antigen exposure (three structurally different proteins, and (3 four antibody repertoire components (V-gene usage, clonal expansion, clonal diversity, repertoire size extracted from antibody repertoire sequencing data (400 million reads. Across all three levels, we detected a dynamic balance of high genetic (e.g., >90% for V-gene usage and clonal expansion in naive B cells and antigen-driven (e.g., 40% for clonal diversity in plasma cells predetermination and stochastic variation. Our study has implications for the prediction and manipulation of humoral immunity.

  17. Cell-Cycle-Dependent Reconfiguration of the DNA Methylome during Terminal Differentiation of Human B Cells into Plasma Cells

    Directory of Open Access Journals (Sweden)

    Gersende Caron

    2015-11-01

    Full Text Available Molecular mechanisms underlying terminal differentiation of B cells into plasma cells are major determinants of adaptive immunity but remain only partially understood. Here we present the transcriptional and epigenomic landscapes of cell subsets arising from activation of human naive B cells and differentiation into plasmablasts. Cell proliferation of activated B cells was linked to a slight decrease in DNA methylation levels, but followed by a committal step in which an S phase-synchronized differentiation switch was associated with an extensive DNA demethylation and local acquisition of 5-hydroxymethylcytosine at enhancers and genes related to plasma cell identity. Downregulation of both TGF-β1/SMAD3 signaling and p53 pathway supported this final step, allowing the emergence of a CD23-negative subpopulation in transition from B cells to plasma cells. Remarkably, hydroxymethylation of PRDM1, a gene essential for plasma cell fate, was coupled to progression in S phase, revealing an intricate connection among cell cycle, DNA (hydroxymethylation, and cell fate determination.

  18. Rituximab and chemotherapy in diffuse large B-cell lymphoma.

    Science.gov (United States)

    Sonet, Anne; Bosly, André

    2009-06-01

    Rituximab is an anti-CD20 chimeric monoclonal antibody with activity in nearly all subtypes of B-cell lymphomas. Association of rituximab with chemotherapy (mostly the cyclophosphamide, doxorubicin, vincristine and prednisolone [CHOP] regimen) in diffuse large B-cell lymphoma (DLBCL) represents an extraordinary revolution in the prognosis of DLBCL, and is the new standard of therapy in elderly and young, low-risk patients. Despite the lack of randomized, clinical trials in younger patients with high risk, rituximab is also a standard of care in these patients in clinical practice, at least in North America. The practice is based on observational trials (e.g., the British Columbia Registry) and the missing logic in classifying patients as 'younger' or 'older': 60 years old or 65 years old. In Europe, trials are ongoing to establish the best treatment for young, high-risk patients. Association of rituximab and chemotherapy deeply modifies prognostic factors defined before the rituximab era.

  19. Bisphosphonates target B cells to enhance humoral immune responses

    Science.gov (United States)

    Tonti, Elena; Jiménez de Oya, Nereida; Galliverti, Gabriele; Moseman, E. Ashley; Di Lucia, Pietro; Amabile, Angelo; Sammicheli, Stefano; De Giovanni, Marco; Sironi, Laura; Chevrier, Nicolas; Sitia, Giovanni; Gennari, Luigi; Guidotti, Luca G.; von Andrian, Ulrich H.; Iannacone, Matteo

    2013-01-01

    Summary Bisphosphonates are a class of drugs that are widely used to inhibit loss of bone mass in patients. We show here that the administration of clinically relevant doses of bisphosphonates in mice increases antibody responses to live and inactive viruses, proteins, haptens and existing commercial vaccine formulations. Bisphosphonates exert this adjuvant-like activity in the absence of CD4+ and γδ T cells, neutrophils or dendritic cells and their effect does not rely on local macrophage depletion nor does it depend upon Toll-like receptor signaling or the inflammasome. Rather, bisphosphonates target directly B cells and enhance B cell expansion and antibody production upon antigen encounter. These data establish bisphosphonates as a novel class of adjuvants that boost humoral immune responses. PMID:24120862

  20. Bisphosphonates Target B Cells to Enhance Humoral Immune Responses

    Directory of Open Access Journals (Sweden)

    Elena Tonti

    2013-10-01

    Full Text Available Bisphosphonates are a class of drugs that are widely used to inhibit loss of bone mass in patients. We show here that the administration of clinically relevant doses of bisphosphonates in mice increases antibody responses to live and inactive viruses, proteins, haptens, and existing commercial vaccine formulations. Bisphosphonates exert this adjuvant-like activity in the absence of CD4+ and γδ T cells, neutrophils, or dendritic cells, and their effect does not rely on local macrophage depletion, Toll-like receptor signaling, or the inflammasome. Rather, bisphosphonates target directly B cells and enhance B cell expansion and antibody production upon antigen encounter. These data establish bisphosphonates as an additional class of adjuvants that boost humoral immune responses.

  1. Antibody B cell responses in HIV-1 infection.

    Science.gov (United States)

    Mouquet, Hugo

    2014-11-01

    In rare cases, B cells can supply HIV-1-infected individuals with unconventional antibodies equipped to neutralize the wide diversity of viral variants. Innovations in single-cell cloning, high-throughput sequencing, and structural biology methods have enabled the capture and thorough characterization of these exceptionally potent broadly neutralizing antibodies (bNAbs). Here, I review the recent findings in humoral responses to HIV-1, focusing on the interplay between naturally occurring bNAbs and the virus both at systemic and mucosal levels. In this context, I discuss how an improved understanding of bNAb generation may provide invaluable insight into the fundamental mechanisms governing adaptive B cell responses to viruses, and how this knowledge is currently contributing to the development of vaccine and therapeutic strategies against HIV-1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Mutation Pattern of Paired Immunoglobulin Heavy and Light Variable Domains in Chronic Lymphocytic Leukemia B Cells

    KAUST Repository

    Ghiotto, Fabio

    2011-01-01

    B-cell chronic lymphocytic leukemia (CLL) patients display leukemic clones bearing either germline or somatically mutated immunoglobulin heavy variable (IGHV ) genes. Most information on CLL immunoglobulins (Igs), such as the definition of stereotyped B-cell receptors (BCRs), was derived from germline unmutated Igs. In particular, detailed studies on the distribution and nature of mutations in paired heavy- and light-chain domains of CLL clones bearing mutated Igs are lacking. To address the somatic hyper-mutation dynamics of CLL Igs, we analyzed the mutation pattern of paired IGHV-diversity-joining (IGHV-D-J ) and immunoglobulin kappa/lambda variable-joining (IGK/LV-J ) rearrangements of 193 leukemic clones that displayed ≥ 2% mutations in at least one of the two immunoglobulin variable (IGV ) genes (IGHV and/or IGK/LV ). The relationship between the mutation frequency in IGHV and IGK/LV complementarity determining regions (CDRs) and framework regions (FRs) was evaluated by correlation analysis. Replacement (R) mutation frequency within IGK/LV chain CDRs correlated significantly with mutation frequency of paired IGHV CDRs in λ but not κ isotype CLL clones. CDRs of IGKV-J rearrangements displayed a lower percentage of R mutations than IGHVs. The frequency/pattern of mutations in kappa CLL Igs differed also from that in κ-expressing normal B cells described in the literature. Instead, the mutation frequency within the FRs of IGHV and either IGKV or IGLV was correlated. Notably, the amount of diversity introduced by replaced amino acids was comparable between IGHVs and IGKVs. The data indicate a different mutation pattern between κ and λ isotype CLL clones and suggest an antigenic selection that, in κ samples, operates against CDR variation.

  3. Complement-dependent transport of antigen into B cell follicles

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Lukacs-Kornek, Veronika; Kuligowski, Michael P.

    2010-01-01

    an additional novel pathway in which complement C3 and its receptors enhance humoral immunity through delivery of Ag to the B cell compartment. In this review, we discuss this pathway and highlight several novel exceptions recently found with a model influenza vaccine, such as mannose-binding lectin...... opsonization of influenza and uptake by macrophages, and the capture of virus by dendritic cells residing in the medullary compartment of peripheral lymph nodes....

  4. Bilateral proliferative retinopathy in B-cell acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Devesh Kumawat

    2018-01-01

    Full Text Available A 4-year-old child with B-cell acute lymphoblastic leukemia presented with vitreous hemorrhage due to proliferative retinopathy in both eyes. Pars plana vitrectomy was performed in both eyes to clear nonresolving vitreous hemorrhage after systemic stabilization. Visual recovery was limited by the disc drag in the right eye and subfoveal exudation in the left eye. Etiopathogenesis and management of proliferative retinopathy in acute leukemias are discussed.

  5. Monomethylarsonous acid (MMA+3) Inhibits IL-7 Signaling in Mouse Pre-B Cells.

    Science.gov (United States)

    Ezeh, Peace C; Xu, Huan; Lauer, Fredine T; Liu, Ke Jian; Hudson, Laurie G; Burchiel, Scott W

    2016-02-01

    Our previously published data show that As(+3) in vivo and in vitro, at very low concentrations, inhibits lymphoid, but not myeloid stem cell development in mouse bone marrow. We also showed that the As(+3) metabolite, monomethylarsonous acid (MMA(+3)), was responsible for the observed pre-B cell toxicity caused by As(+3). Interleukin-7 (IL-7) is the primary growth factor responsible for pre-lymphoid development in mouse and human bone marrow, and Signal Transducer and Activator of Transcription 5 (STAT5) is a transcriptional factor in the IL-7 signaling pathway. We found that MMA(+3) inhibited STAT5 phosphorylation at a concentration as low as 50 nM in mouse bone marrow pre-B cells. Inhibition of STAT5 phosphorylation by As(+3) occurred only at a concentration of 500 nM. In the IL-7 dependent mouse pre-B 2E8 cell line, we also found selective inhibition of STAT5 phosphorylation by MMA(+3), and this inhibition was dependent on effects on JAK3 phosphorylation. IL-7 receptor expression on 2E8 cell surface was also suppressed by 50 nM MMA(+3) at 18 h. As further evidence for the inhibition of STAT5, we found that the induction of several genes required in B cell development, cyclin D1, E2A, EBF1, and PAX5, were selectively inhibited by MMA(+3). Since 2E8 cells lack the enzymes responsible for the conversion of As(+3) to MMA(+3) in vitro, the results of these studies suggest that As(+3) induced inhibition of pre-B cell formation in vivo is likely dependent on the formation of MMA(+3) which in turn inhibits IL-7 signaling at several steps in mouse pre-B cells. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Retinoic acid induces the differentiation of B cell hybridomas from patients with common variable immunodeficiency.

    Science.gov (United States)

    Sherr, E; Adelman, D C; Saxon, A; Gilly, M; Wall, R; Sidell, N

    1988-07-01

    Human-human B cell hybridomas constructed from B lymphocytes of common variable immunodeficiency (CVI) patients and the nonsecreting cell line WIL2/729 HF consistently secrete low levels of Ig and appear to retain a defect characteristic of the CVI patient's B cells. We assessed the differentiative capacity of retinoic acid (RA) on these hybridomas, as well as on hybridomas constructed from normal B cells and from patients with selective IgA deficiency. RA at concentrations varying between 10(-5) and 10(-9) M augmented IgM secretion 4-20-fold from four of four CVI hybridomas tested, but did not affect Ig secretion from normal or IgA-deficiency hybridomas. In support of this elevated Ig secretion, RA enhanced the de novo synthesis of biosynthetically labeled light (kappa) and heavy (mu) Ig (up to 4- and 15-fold, respectively) in the CVI hybridoma line JK32.1. The increase in IgM synthesis/secretion could not be accounted for by RA-induced alteration in the cell cycle. In inducing this increase in IgM production, RA was found to affect two aspects of Ig gene expression: (a) the steady-state levels of heavy and light chain mRNAs were enhanced, and (b) the processing of mu heavy chain transcripts to the secreted mRNA form became favored over the membrane mRNA form. We also show that expression of Leu-17 (CD38), a surface marker that is re-expressed in the late pre-plasma stage of B cell development, was increased by RA from less than 20% to greater than 90% of the total cell population, with a concomitant 4-10-fold augmentation in the mean fluorescence intensity. Changes in both Leu-17 expression and de novo Ig synthesis were prominent by 24 h, but could be observed as early as 8 h after induction. Taken together, our study demonstrates that RA affects a marked alteration in the differentiated state of the CVI hybridoma clones. This finding suggests that retinoids can enhance the functional capabilities of B cells with defects in maturation and support further studies

  7. Altered B cell homeostasis and Toll-like receptor 9-driven response in patients affected by autoimmune polyglandular syndrome Type 1: Altered B cell phenotype and dysregulation of the B cell function in APECED patients.

    Science.gov (United States)

    Perri, Valentina; Gianchecchi, Elena; Scarpa, Riccardo; Valenzise, Mariella; Rosado, Maria Manuela; Giorda, Ezio; Crinò, Antonino; Cappa, Marco; Barollo, Susi; Garelli, Silvia; Betterle, Corrado; Fierabracci, Alessandra

    2017-02-01

    APECED is a T-cell mediated disease with increased frequencies of CD8+ effector and reduction of FoxP3+ T regulatory cells. Antibodies against affected organs and neutralizing to cytokines are found in the peripheral blood. The contribution of B cells to multiorgan autoimmunity in Aire-/- mice was reported opening perspectives on the utility of anti-B cell therapy. We aimed to analyse the B cell phenotype of APECED patients compared to age-matched controls. FACS analysis was conducted on PBMC in basal conditions and following CpG stimulation. Total B and switched memory (SM) B cells were reduced while IgM memory were increased in patients. In those having more than 15 years from the first clinical manifestation the defect included also mature and transitional B cells; total memory B cells were increased, while SM were unaffected. In patients with shorter disease duration, total B cells were unaltered while SM and IgM memory behaved as in the total group. A defective B cell proliferation was detected after 4day-stimulation. In conclusion APECED patients show, in addition to a significant alteration of the B cell phenotype, a dysregulation of the B cell function involving peripheral innate immune mechanisms particularly those with longer disease duration. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. [Bone marrow involvement in primary mediastinal B-cell lymphoma].

    Science.gov (United States)

    Magomedova, A U; Fastova, E A; Kovrigina, A M; Obukhova, T N; Skidan, N I; Mangasarova, Ya K; Vorobyev, A I; Kravchenko, S K

    Primary mediastinal large B-cell lymphoma (PMBCL) is a distinct type of large B-cell lymphoma. In this type of the disease, the neoplastic process is located in the anterior and superior mediastinum, frequently with compression of the superior vena cava and with tumor invasion into the adjacent organs and tissues: the pericardium, lung, pleura, etc. Despite the fact that in PMBCL progression, there may be involvement of extranodal organs, such as the kidney, adrenal glands, liver, and central nervous system, bone marrow (BM) injury is generally absent. Since BM injury in patients with diffuse large B-cell lymphoma is an independent poor prognostic indicator, there is reason to believe that BM involvement in PMBCL affects the prognosis. These cases may need intensified induction therapy followed by autologous hematopoietic stem cell transplantation; and BM injury should be monitored during the therapy. The paper gives reports of clinical cases of bone marrow involvement in 2 PMBCL patients treated at the National Research Center for Hematology, Ministry of Health of the Russian Federation.

  9. The acquisition of cytokine responsiveness by murine B cells

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1994-01-01

    The mechanism whereby small resting (high buoyant density) murine B cells are induced to express interleukin-2 receptors (IL-2R) and to respond to IL-2 was addressed by staining with anti-IL-2R alpha and -IL-2R beta monoclonal antibodies (mAb), and using receptor-specific cDNA probes. Resting B...... cells expressed undetectable levels of both IL-2R alpha and beta chains on their surface and did not respond to IL-2, even at supra-physiological concentrations. Sepharose-coupled, but not streptavidin-cross-linked, plastic-adsorbed or soluble, anti-mu up-regulated the expression of IL-2R alpha and beta...... chains and mRNA to levels comparable to those seen in activated T cells. Anti-mu-stimulated B cells responded to IL-2 by incorporation of [3H]thymidine and high rate immunoglobulin (Ig) secretion. Both IL-5 (at optimal concentration) and suboptimal lipopolysaccharide (LPS; 20 ng/ml) induced surface...

  10. Quantitative regulation of B cell division destiny by signal strength.

    Science.gov (United States)

    Turner, Marian L; Hawkins, Edwin D; Hodgkin, Philip D

    2008-07-01

    Differentiation to Ab secreting and isotype-switched effector cells is tightly linked to cell division and therefore the degree of proliferation strongly influences the nature of the immune response. The maximum number of divisions reached, termed the population division destiny, is stochastically distributed in the population and is an important parameter in the quantitative outcome of lymphocyte responses. In this study, we further assessed the variables that regulate B cell division destiny in vitro in response to T cell- and TLR-dependent stimuli. Both the concentration and duration of stimulation were able to regulate the average maximum number of divisions undergone for each stimulus. Notably, a maximum division destiny was reached during provision of repeated saturating stimulation, revealing that an intrinsic limit to proliferation exists even under these conditions. This limit was linked directly to division number rather than time of exposure to stimulation and operated independently of the survival regulation of the cells. These results demonstrate that a B cell population's division destiny is regulable by the stimulatory conditions up to an inherent maximum value. Division destiny is a crucial parameter in regulating the extent of B cell responses and thereby also the nature of the immune response mounted.

  11. Lenalidomide in Diffuse Large B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Annalisa Chiappella

    2012-01-01

    Full Text Available Diffuse Large B-cell Lymphomas (DLBCL are the most frequent Non-Hodgkin Lymphomas (NHL. The addition of Rituximab to the standard chemotherapy CHOP improved the outcome in this patients, but so far 40% of patients experienced relapse or progressive disease. Lenalidomide, an immunomodulatory agent, had direct tumoricidal and antiangiogenetic actions on tumor cells and was able to modulate tumor-cell microenvironment, with the restoration of impaired T-cell activity and the formation of immuno-synapsis. Based on these actions, lenalidomide represented an active drug on aggressive relapsed NHL. In this review, the most relevant clinical trials for the use of lenalidomide in DLBCL were reported. Monotherapy with lenalidomide showed an activity in term of overall response rate, with acceptable hematological and extrahematological toxicities in relapsed/refractory aggressive NHL. The role of lenalidomide as salvage therapy in both cell of origin patterns in DLBCL (germinal center B-cell/activated B-cell was reported in preliminary data. Preliminary data regarding the role of lenalidomide in addition to chemoimmunotherapy (R-CHOP in first line clinical trials were discussed; data of safety, feasibility and efficacy were promising.

  12. B cell remote-handled waste shipment cask alternatives study

    International Nuclear Information System (INIS)

    RIDDELLE, J.G.

    1999-01-01

    The decommissioning of the 324 Facility B Cell includes the onsite transport of grouted remote-handled radioactive waste from the 324 Facility to the 200 Areas for disposal. The grouted waste has been transported in the leased ATG Nuclear Services 3-82B Radioactive Waste Shipping Cask (3-82B cask). Because the 3-82B cask is a U.S. Nuclear Regulatory Commission (NRC)-certified Type B shipping cask, the lease cost is high, and the cask operations in the onsite environment may not be optimal. An alternatives study has been performed to develop cost and schedule information on alternative waste transportation systems to assist in determining which system should be used in the future. Five alternatives were identified for evaluation. These included continued lease of the 3-82B cask, fabrication of a new 3-82B cask, development and fabrication of an onsite cask, modification of the existing U.S. Department of Energy-owned cask (OH-142), and the lease of a different commercially available cask. Each alternative was compared to acceptance criteria for use in the B Cell as an initial screening. Only continued leasing of the 3-82B cask, fabrication of a new 3-82B cask, and the development and fabrication of an onsite cask were found to meet all of the B Cell acceptance criteria

  13. CD3-positive B cells: a storage-dependent phenomenon.

    Directory of Open Access Journals (Sweden)

    Angela Nagel

    Full Text Available The majority of clinical studies requires extensive management of human specimen including e.g. overnight shipping of blood samples in order to convey the samples in a central laboratory or to simultaneously analyze large numbers of patients. Storage of blood samples for periods of time before in vitro/ex vivo testing is known to influence the antigen expression on the surface of lymphocytes. In this context, the present results show for the first time that the T cell antigen CD3 can be substantially detected on the surface of human B cells after ex vivo storage and that the degree of this phenomenon critically depends on temperature and duration after blood withdrawal. The appearance of CD3 on the B cell surface seems to be a result of contact-dependent antigen exchange between T and B lymphocytes and is not attributed to endogenous production by B cells. Since cellular subsets are often classified by phenotypic analyses, our results indicate that ex vivo cellular classification in peripheral blood might result in misleading interpretations. Therefore, in order to obtain results reflecting the in vivo situation, it is suggested to minimize times of ex vivo blood storage after isolation of PBMC. Moreover, to enable reproducibility of results between different research groups and multicenter studies, we would emphasize the necessity to specify and standardize the storage conditions, which might be the basis of particular findings.

  14. B cell progenitors are arrested in maturation but have intact VDJ recombination in the absence of Ig-alpha and Ig-beta.

    Science.gov (United States)

    Pelanda, Roberta; Braun, Uschi; Hobeika, Elias; Nussenzweig, Michel C; Reth, Michael

    2002-07-15

    Ig-alpha and Ig-beta mediate surface expression and signaling of diverse B cell receptor complexes on precursor, immature, and mature B cells. Their expression begins before that of the Ig chains in early progenitor B cells. In this study, we describe the generation of Ig-alpha-deficient mice and their comparative analysis to mice deficient for Ig-beta, the membrane-IgM, and recombination-activating gene 2 to determine the requirement of Ig-alpha and Ig-beta in survival and differentiation of pro-B cells. We find that in the absence of Ig-alpha, B cell development does not progress beyond the progenitor stage, similar to what is observed in humans lacking this molecule. However, neither in Ig-alpha- nor in Ig-beta-deficient mice are pro-B cells impaired in V(D)J recombination, in the expression of intracellular Ig micro-chains, or in surviving in the bone marrow microenvironment. Finally, Ig-alpha and Ig-beta are not redundant in their putative function, as pro-B cells from Ig-alpha and Ig-beta double-deficient mice are similar to those from single-deficient animals in every aspect analyzed.

  15. Nivolumab With or Without Varlilumab in Treating Patients With Relapsed or Refractory Aggressive B-cell Lymphomas

    Science.gov (United States)

    2018-03-12

    ALK-Positive Large B-Cell Lymphoma; Atypical Burkitt/Burkitt-Like Lymphoma; Burkitt-Like Lymphoma With 11q Aberration; Diffuse Large B-Cell Lymphoma Activated B-Cell Type; Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation; Diffuse Large B-Cell Lymphoma Germinal Center B-Cell Type; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; EBV-Positive Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; EBV-Positive Mucocutaneous Ulcer; High-Grade B-Cell Lymphoma With MYC, BCL2, and BCL6 Rearrangements; Human Herpesvirus 8-Positive Neoplastic Cells Present; Intravascular Large B-Cell Lymphoma; Large B-Cell Lymphoma With IRF4 Rearrangement; Plasmablastic Lymphoma; Primary Cutaneous Diffuse Large B-Cell Lymphoma; Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type; Primary Diffuse Large B-Cell Lymphoma of the Central Nervous System; Primary Effusion Lymphoma; Recurrent B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classical Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Lymphomatoid Granulomatosis; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classical Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Small Intestinal High Grade B-Cell Lymphoma, Not Otherwise Specified; T-Cell/Histiocyte-Rich Large B-Cell Lymphoma

  16. R-ICE and Lenalidomide in Treating Patients With First-Relapse/Primary Refractory Diffuse Large B-Cell Lymphoma

    Science.gov (United States)

    2018-03-27

    CD20 Positive; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Transformed Recurrent Non-Hodgkin Lymphoma

  17. Racial differences in B cell receptor signaling pathway activation.

    Science.gov (United States)

    Longo, Diane M; Louie, Brent; Mathi, Kavita; Pos, Zoltan; Wang, Ena; Hawtin, Rachael E; Marincola, Francesco M; Cesano, Alessandra

    2012-06-06

    Single-cell network profiling (SCNP) is a multi-parametric flow cytometry-based approach that simultaneously measures basal and modulated intracellular signaling activity in multiple cell subpopulations. Previously, SCNP analysis of a broad panel of immune signaling pathways in cell subsets within PBMCs from 60 healthy donors identified a race-associated difference in B cell anti-IgD-induced PI3K pathway activity. The present study extended this analysis to a broader range of signaling pathway components downstream of the B cell receptor (BCR) in European Americans and African Americans using a subset of donors from the previously analyzed cohort of 60 healthy donors. Seven BCR signaling nodes (a node is defined as a paired modulator and intracellular readout) were measured at multiple time points by SCNP in PBMCs from 10 healthy donors [5 African Americans (36-51 yrs), 5 European Americans (36-56 yrs), all males]. Analysis of BCR signaling activity in European American and African American PBMC samples revealed that, compared to the European American donors, B cells from African Americans had lower anti-IgD induced phosphorylation of multiple BCR pathway components, including the membrane proximal proteins Syk and SFK as well as proteins in the PI3K pathway (S6 and Akt), the MAPK pathways (Erk and p38), and the NF-κB pathway (NF-κB). In addition to differences in the magnitude of anti-IgD-induced pathway activation, racial differences in BCR signaling kinetic profiles were observed. Further, the frequency of IgD+ B cells differed by race and strongly correlated with BCR pathway activation. Thus, the race-related difference in BCR pathway activation appears to be attributable at least in part to a race-associated difference in IgD+ B cell frequencies. SCNP analysis enabled the identification of statistically significant race-associated differences in BCR pathway activation within PBMC samples from healthy donors. Understanding race-associated contrasts in immune

  18. Racial differences in B cell receptor signaling pathway activation

    Directory of Open Access Journals (Sweden)

    Longo Diane M

    2012-06-01

    Full Text Available Abstract Background Single-cell network profiling (SCNP is a multi-parametric flow cytometry-based approach that simultaneously measures basal and modulated intracellular signaling activity in multiple cell subpopulations. Previously, SCNP analysis of a broad panel of immune signaling pathways in cell subsets within PBMCs from 60 healthy donors identified a race-associated difference in B cell anti-IgD-induced PI3K pathway activity. Methods The present study extended this analysis to a broader range of signaling pathway components downstream of the B cell receptor (BCR in European Americans and African Americans using a subset of donors from the previously analyzed cohort of 60 healthy donors. Seven BCR signaling nodes (a node is defined as a paired modulator and intracellular readout were measured at multiple time points by SCNP in PBMCs from 10 healthy donors [5 African Americans (36-51 yrs, 5 European Americans (36-56 yrs, all males]. Results Analysis of BCR signaling activity in European American and African American PBMC samples revealed that, compared to the European American donors, B cells from African Americans had lower anti-IgD induced phosphorylation of multiple BCR pathway components, including the membrane proximal proteins Syk and SFK as well as proteins in the PI3K pathway (S6 and Akt, the MAPK pathways (Erk and p38, and the NF-κB pathway (NF-κB. In addition to differences in the magnitude of anti-IgD-induced pathway activation, racial differences in BCR signaling kinetic profiles were observed. Further, the frequency of IgD+ B cells differed by race and strongly correlated with BCR pathway activation. Thus, the race-related difference in BCR pathway activation appears to be attributable at least in part to a race-associated difference in IgD+ B cell frequencies. Conclusions SCNP analysis enabled the identification of statistically significant race-associated differences in BCR pathway activation within PBMC samples from

  19. Type i CD20 antibodies recruit the B cell receptor for complement-dependent lysis of malignant B cells

    DEFF Research Database (Denmark)

    Engelberts, P. J.; Voorhorst, M.; Schuurman, J.

    2016-01-01

    . We hypothesized that CD20 Ab-induced clustering of the IgM or IgG BCR was involved in accessory CDC. Indeed, accessory CDC was consistently observed in B cell lines expressing an IgM BCR and in some cell lines expressing an IgG BCR, but it was absent in BCR- B cell lines. A direct relationship...... between BCR expression and accessory CDC was established by transfecting the BCR into CD20+ cells: OFA-F(ab')2 fragments were able to induce CDC in the CD20+BCR+ cell population, but not in the CD20+BCR- population. Importantly, OFA-F(ab')2 fragments were able to induce CDC ex vivo in malignant B cells...... isolated from patients with mantle cell lymphoma and Waldenström macroglobulinemia. In summary, accessory CDC represents a novel effector mechanism that is dependent on type I CD20 Ab-induced BCR clustering. Accessory CDC may contribute to the excellent capacity of type I CD20 Abs to induce CDC...

  20. Characterization of Regulatory B Cells in Graves' Disease and Hashimoto's Thyroiditis

    DEFF Research Database (Denmark)

    Kristensen, Birte; Hegedüs, Laszlo; Lundy, Steven K

    2015-01-01

    A hallmark of regulatory B cells is IL-10 production, hence their designation as IL-10+ B cells. Little is known about the ability of self-antigens to induce IL-10+ B cells in Graves' disease (GD), Hashimoto's thyroiditis (HT), or other autoimmune disease. Here we pulsed purified B cells from 12 HT...... patients, 12 GD patients, and 12 healthy donors with the thyroid self-antigen, thyroglobulin (TG) and added the B cells back to the remaining peripheral blood mononuclear cells (PBMCs). This procedure induced IL-10+ B-cell differentiation in GD. A similar tendency was observed in healthy donors......, but not in cells from patients with HT. In GD, B cells primed with TG induced IL-10-producing CD4+ T cells. To assess the maximal frequency of inducible IL-10+ B cells in the three donor groups PBMCs were stimulated with PMA/ionomycin. The resulting IL-10+ B-cell frequency was similar in the three groups...

  1. Generation of Recombinant Monoclonal Antibodies from Immunised Mice and Rabbits via Flow Cytometry and Sorting of Antigen-Specific IgG+ Memory B Cells.

    Directory of Open Access Journals (Sweden)

    Dale O Starkie

    Full Text Available Single B cell screening strategies, which avoid both hybridoma fusion and combinatorial display, have emerged as important technologies for efficiently sampling the natural antibody repertoire of immunized animals and humans. Having access to a range of methods to interrogate different B cell subsets provides an attractive option to ensure large and diverse panels of high quality antibody are produced. The generation of multiple antibodies and having the ability to find rare B cell clones producing IgG with unique and desirable characteristics facilitates the identification of fit-for-purpose molecules that can be developed into therapeutic agents or research reagents. Here, we describe a multi-parameter flow cytometry single-cell sorting technique for the generation of antigen-specific recombinant monoclonal antibodies from single IgG+ memory B cells. Both mouse splenocytes and rabbit PBMC from immunised animals were used as a source of B cells. Reagents staining both B cells and other unwanted cell types enabled efficient identification of class-switched IgG+ memory B cells. Concurrent staining with antigen labelled separately with two spectrally-distinct fluorophores enabled antigen-specific B cells to be identified, i.e. those which bind to both antigen conjugates (double-positive. These cells were then typically sorted at one cell per well using FACS directly into a 96-well plate containing reverse transcriptase reaction mix. Following production of cDNA, PCR was performed to amplify cognate heavy and light chain variable region genes and generate transcriptionally-active PCR (TAP fragments. These linear expression cassettes were then used directly in a mammalian cell transfection to generate recombinant antibody for further testing. We were able to successfully generate antigen-specific recombinant antibodies from both the rabbit and mouse IgG+ memory B cell subset within one week. This included the generation of an anti-TNFR2 blocking

  2. A Rapid Embryonic Stem Cell-Based Mouse Model for B-cell Lymphomas Driven by Epstein-Barr Virus Protein LMP1.

    Science.gov (United States)

    Ba, Zhaoqing; Meng, Fei-Long; Gostissa, Monica; Huang, Pei-Yi; Ke, Qiang; Wang, Zhe; Dao, Mai N; Fujiwara, Yuko; Rajewsky, Klaus; Zhang, Baochun; Alt, Frederick W

    2015-06-01

    The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) contributes to oncogenic human B-cell transformation. Mouse B cells conditionally expressing LMP1 are not predisposed to B-cell malignancies, as LMP1-expressing B cells are eliminated by T cells. However, mice with conditional B-cell LMP1 expression and genetic elimination of α/β and γ/δ T cells ("CLT" mice) die early in association with B-cell lymphoproliferation and lymphomagenesis. Generation of CLT mice involves in-breeding multiple independently segregating alleles. Thus, although introduction of additional activating or knockout mutations into the CLT model is desirable for further B-cell expansion and immunosurveillance studies, doing such experiments by germline breeding is time-consuming, expensive, and sometimes unfeasible. To generate a more tractable model, we generated clonal CLT embryonic stem (ES) cells from CLT embryos and injected them into RAG2-deficient blastocysts to generate chimeric mice, which, like germline CLT mice, harbor splenic CLT B cells and lack T cells. CLT chimeric mice generated by this RAG2-deficient blastocyst complementation ("RDBC") approach die rapidly in association with B-cell lymphoproliferation and lymphoma. Because CLT lymphomas routinely express the activation-induced cytidine deaminase (AID) antibody diversifier, we tested potential AID roles by eliminating the AID gene in CLT ES cells and testing them via RDBC. We found that CLT and AID-deficient CLT ES chimeras had indistinguishable phenotypes, showing that AID is not essential for LMP1-induced lymphomagenesis. Beyond expanding accessibility and utility of CLT mice as a cancer immunotherapy model, our studies provide a new approach for facilitating generation of genetically complex mouse cancer models. ©2015 American Association for Cancer Research.

  3. B cell receptor signaling pathway involved in benign lymphoepithelial lesions of the lacrimal gland

    Directory of Open Access Journals (Sweden)

    Xiao-Na Wang

    2017-05-01

    Full Text Available AIM: To detect the expression of B cell receptor signaling pathway (BCRSP in lacrimal gland benign lymphoepithelial lesions (LGBLEL. METHODS: Gene microarray was used to compare whole-genome expression in lacrimal gland tissues from LGBLEL patients to tissues from orbital cavernous hemangioma (control tissues. Expression of BCRSP was confirmed by polymerase chain reaction (PCR and immunohistochemistry. RESULTS: The expression of 22 genes of the BCRSP increased significantly in LGBLEL patients. PCR analysis showed that CD22, CR2, and BTK were all highly expressed in LGBLEL tissues. Immunohistochemical analysis showed that CR2 protein was present in LGBLEL, but CD22 and BTK proteins were negative. CR2, CD22, and BTK were not observed in the orbital cavernous hemangiomas with either PCR or immunohistochemistry. CONCLUSION: BCRSP might be involved in the pathogenesis of LGBLEL.

  4. Discovery and Characterization of Super-Enhancer Associated Dependencies in Diffuse Large B-Cell Lymphoma

    Science.gov (United States)

    Chapuy, Bjoern; McKeown, Michael R.; Lin, Charles Y.; Monti, Stefano; Roemer, Margaretha G.M.; Qi, Jun; Rahl, Peter B.; Sun, Heather H.; Yeda, Kelly T.; Doench, John G; Reichert, Elaine; Kung, Andrew L.; Rodig, Scott J.; Young, Richard A.; Shipp, Margaret A.; Bradner, James E.

    2014-01-01

    Summary Diffuse Large B-Cell Lymphoma (DLBCL) is a biologically heterogeneous and clinically aggressive disease. Here, we explore the role of BET bromodomain proteins in DLBCL, using integrative chemical genetics and functional epigenomics. We observe highly asymmetric loading of BRD4 at enhancers, with approximately 33% of all BRD4 localizing to enhancers at 1.6% of occupied genes. These super-enhancers prove particularly sensitive to bromodomain inhibition, explaining the selective effect of BET inhibitors on oncogenic and lineage-specific transcriptional circuits. Functional study of genes marked by super-enhancers identifies DLBCLs dependent on OCA-B and suggests a strategy for discovering unrecognized cancer dependencies. Translational studies performed on a comprehensive panel of DLBCLs establish a therapeutic rationale for evaluating BET inhibitors in this disease. PMID:24332044

  5. Ia-restricted B-B cell interaction. I. The MHC haplotype of bone marrow cells present during B cell ontogeny dictates the self-recognition specificity of B cells in the polyclonal B cell activation by a B cell differentiation factor, B151-TRF2

    International Nuclear Information System (INIS)

    Ono, S.; Takahama, Y.; Hamaoka, T.

    1987-01-01

    We have demonstrated that B cell recognition of Ia molecules is involved in polyclonal B cell differentiation by B151-TRF2. The present study was undertaken to examine the Ia recognition specificity of B151-TRF2-responsive B cells in fully major histocompatibility complex (MHC)-allogeneic P1----P2, semiallogeneic P1----(P1 x P2)F1, and double donor (P1 + P2)----(P1 x P2)F1 and (P1 + P2)----P1 radiation bone marrow chimeras. The B cells from both P1----P2 and P1----(P1 x P2)F1 chimeras could give rise to in vitro immunoglobulin M-producing cells upon stimulation with B151-TRF2 comparable in magnitude to that of normal P1 B cells, and their responses were inhibited by anti-I-AP1 but not by anti-I-AP2 monoclonal antibody even in the presence of mitomycin C-treated T cell-depleted P2 spleen cells as auxiliary cells. In contrast, the B151-TRF2 responses of P1 B cells isolated from both (P1 + P2)----(P1 x P2)F1 and (P1 + P2)----P1 double bone marrow chimeras became sensitive to the inhibition of not only anti-I-AP1 but also anti-I-AP2 monoclonal antibody only when the culture was conducted in the presence of P2 auxiliary cells, demonstrating that they adaptively differentiate to recognize as self-structures allogeneic as well as syngeneic Ia molecules. Moreover, the experiments utilizing B cells from H-2-congenic mice and B cell hybridoma clones as auxiliary cells revealed that B151-TRF2-responsive B cells recognize Ia molecules expressed on B cells. Taken together, these results demonstrate that B151-TRF2-responsive B cells recognize Ia molecules expressed by B cells as self-structures and that their self-recognition specificity is dictated by the MHC haplotype of bone marrow cells present during the B cell ontogeny but not by the MHC haplotype of a radiation-resistant host environment

  6. The Epstein-Barr virus microRNA BART11-5p targets the early B-cell transcription factor EBF1.

    Science.gov (United States)

    Ross, Nathan; Gandhi, Maher K; Nourse, Jamie P

    2013-01-01

    Epstein-Barr virus (EBV) is a ubiquitous B-cell trophic herpesvirus associated with a variety of histologically diverse B-cell lymphomas, each associated with specific viral-latency gene expression programs. Initial infection drives resting B-cells to differentiate via an atypical germinal centre reaction into memory B-cells, where the virus resides in a latent state. The mechanisms that underpin this process have yet to be fully elucidated. EBV expresses more than 40 microRNAs (miRNAs). The alternatively spliced BamHI A rightward transcripts (BARTs) are the template for two large miRNA clusters (BARTs A and B), that comprise the majority of all known EBV-miRNAs. Although BART-miRNAs are abundantly expressed in all latency programs, few BART-miRNA targets have been identified and their function is poorly understood. The early B-cell factor 1 (EBF1) was identified using bioinformaticss analysis as a novel target of EBV-miRNA BART11-5p, encoded by BART cluster B. EBF1 is an important B-cell transcription factor that regulates many B-cell specific genes including Pax5, BCR and CD40 and is critical for germinal centre formation. Using luciferase reporter assays and a series of BART-constructs, we confirmed silencing via the EBF1 3' untranslated region (UTR) and identified the target site as 2137-2159 bp after the stop codon. Results were confirmed following transfection of a BART11-5p mimic, which was able to silence via the predicted target site. Our findings highlight a potential role of BART-miRNAs in the regulation of B-cell differentiation.

  7. MicroRNAs as novel biomarkers in diffuse large B-cell lymphoma--a systematic review

    DEFF Research Database (Denmark)

    Jørgensen, Laura Krogh; Poulsen, Mette Østergaard; Laursen, Maria Bach

    2014-01-01

    Introduction: MicroRNAs (miRNAs) are short non-coding RNAs that have the ability to regulate gene expression at the post-transcriptional level. MiRNAs are deregulated in many cancer types, and several miRNAs have been suggested as novel diagnostic and prognostic biomarkers in diffuse large B-cell...... in DLBCL, which would contribute to an era of more personalised medicine....

  8. XPO1 in B cell hematological malignancies: from recurrent somatic mutations to targeted therapy

    Directory of Open Access Journals (Sweden)

    Vincent Camus

    2017-02-01

    Full Text Available Abstract Many recent publications highlight the large role of the pivotal eukaryotic nuclear export protein exportin-1 (XPO1 in the oncogenesis of several malignancies, and there is emerging evidence that XPO1 inhibition is a key target against cancer. The clinical validation of the pharmacological inhibition of XPO1 was recently achieved with the development of the selective inhibitor of nuclear export compounds, displaying an interesting anti-tumor activity in patients with massive pre-treated hematological malignancies. Recent reports have shown molecular alterations in the gene encoding XPO1 and showed a mutation hotspot (E571K in the following two hematological malignancies with similar phenotypes and natural histories: primary mediastinal diffuse large B cell lymphoma and classical Hodgkin’s lymphoma. Emerging evidence suggests that the mutant XPO1 E571K plays a role in carcinogenesis, and this variant is quantifiable in tumor and plasma cell-free DNA of patients using highly sensitive molecular biology techniques, such as digital PCR and next-generation sequencing. Therefore, it was proposed that the XPO1 E571K variant may serve as a minimal residual disease tool in this setting. To clarify and summarize the recent findings on the role of XPO1 in B cell hematological malignancies, we conducted a literature search to present the major publications establishing the landscape of XPO1 molecular alterations, their impact on the XPO1 protein, their interest as biomarkers, and investigations into the development of new XPO1-targeted therapies in B cell hematological malignancies.

  9. Optimizing Outcomes in Primary Mediastinal B-cell Lymphoma.

    Science.gov (United States)

    Zinzani, Pier Luigi; Broccoli, Alessandro

    2016-12-01

    Primary mediastinal B-cell lymphoma is characterized by a high chance of cure, and cured patients have a long disease-free life-expectancy; however, prognosis is severe in the case of relapsed or refractory disease. The initial use of the most effective chemoimmunotherapy regimen is therefore crucial. Understanding who will benefit from postinduction radiotherapy is also of paramount importance; positron emission tomography may be a reliable guide for physicians in determining which patients will require consolidation. New drugs with mechanisms of action including the most relevant biologic features of the tumor may allow better disease control. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Diffuse Large B-Cell Lymphoma with Calf Muscle Localization

    Directory of Open Access Journals (Sweden)

    Laura Bourdeanu

    2011-01-01

    Full Text Available Although diffuse large B-cell lymphoma (DLBCL usually occurs in the lymph nodes, approximately 30–40% of the time it can have an extranodal site of involvement and it can arise in nearly every body site such as intestine, bone, breast, liver, skin, lung, and central nervous system. Muscle involvement of DLBCL is especially uncommon, comprising 0.5% of extranodal NHL. We report a case of a 72-year-old man with extranodal DLBCL of a unique manifestation in the calf muscle, involving predominantly the gastrocnemius muscle. The patient achieved complete response and remained free of local recurrence or metastasis following diagnosis.

  11. Diffuse large B-cell lymphoma of the oral cavity

    International Nuclear Information System (INIS)

    Carlos Bortoluzzi, Marcelo

    2010-01-01

    The authors report a case of diffuse large B-cell lymphoma (DLBL) of the oral cavity. The patient was a 73-year-old white man who first presented at the Division of Stomatology with a large nodular mass in the hard palate and a nodular lesion in the upper lip, which were diagnosed as DLBL. The patient was treated with eight cycles of CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone), but the disease recurred 22 months after the end of the therapy. Both primary sites hard palate and upper lip were involved again and the patient was resubmitted to chemotherapy. (author)

  12. Ebf1 and c-Myb repress rag transcription downstream of Stat5 during early B cell development.

    Science.gov (United States)

    Timblin, Greg A; Schlissel, Mark S

    2013-11-01

    The temporal control of RAG (Rag) expression in developing lymphocytes prevents DNA breaks during periods of proliferation that could threaten genomic integrity. In developing B cells, the IL-7R and precursor B cell Ag receptor (pre-BCR) synergize to induce proliferation and the repression of Rag at the protein and mRNA levels for a brief period following successful Ig H chain gene rearrangement. Whereas the mechanism of RAG2 protein downregulation is well defined, little is known about the pathways and transcription factors that mediate transcriptional repression of Rag. Using Abelson murine leukemia virus-transformed B cells to model this stage of development, we identified early B cell factor 1 (Ebf1) as a strong repressor of Rag transcription. Short hairpin RNA-mediated knockdown of either Ebf1 or its downstream target c-Myb was sufficient to induce Rag transcription in these highly proliferative cells. Ebf1 and c-Myb antagonize Rag transcription by negatively regulating the binding of Foxo1 to the Rag locus. Ebf1 accomplishes this through both direct negative regulation of Foxo1 expression and direct positive regulation of Gfi1b expression. Ebf1 expression is driven by the IL-7R downstream effector Stat5, providing a link between the negative regulation of Rag transcription by IL-7 and a novel repressive pathway involving Ebf1 and c-Myb.

  13. Age-Associated Decline in Thymic B Cell Expression of Aire and Aire-Dependent Self-Antigens

    Directory of Open Access Journals (Sweden)

    Sergio Cepeda

    2018-01-01

    Full Text Available Although autoimmune disorders are a significant source of morbidity and mortality in older individuals, the mechanisms governing age-associated increases in susceptibility remain incompletely understood. Central T cell tolerance is mediated through presentation of self-antigens by cells constituting the thymic microenvironment, including epithelial cells, dendritic cells, and B cells. Medullary thymic epithelial cells (mTECs and B cells express distinct cohorts of self-antigens, including tissue-restricted self-antigens (TRAs, such that developing T cells are tolerized to antigens from peripheral tissues. We find that expression of the TRA transcriptional regulator Aire, as well as Aire-dependent genes, declines with age in thymic B cells in mice and humans and that cell-intrinsic and cell-extrinsic mechanisms contribute to the diminished capacity of peripheral B cells to express Aire within the thymus. Our findings indicate that aging may diminish the ability of thymic B cells to tolerize T cells, revealing a potential mechanistic link between aging and autoimmunity.

  14. Probiotics enhance the effect of allergy immunotherapy on regulating antigen specific B cell activity in asthma patients.

    Science.gov (United States)

    Liu, Jun; Chen, Feng-Hong; Qiu, Shu-Qi; Yang, Li-Tao; Zhang, Huan-Ping; Liu, Jiang-Qi; Geng, Xiao-Rui; Yang, Gui; Liu, Zhi-Qiang; Li, Jing; Liu, Zhi-Gang; Li, Hua-Bin; Yang, Ping-Chang

    2016-01-01

    Immune regulatory system dysfunction plays a role in the pathogenesis of asthma. The therapeutic effect of allergic asthma is to be improved. The immune regulatory function of probiotics has been recognized. This study tests a hypothesis that Clostridium butyricum (CB) enhances the effect of allergen specific immunotherapy (AIT) on asthma. In this study patients with allergic asthma were treated with AIT or/and CB for six months. The therapeutic effect and IgE production of the patients were observed. The results showed that administration with AIT alone alleviated the asthma symptoms; but the serum levels of interleukin (IL)-4, IL-5, IL-13 and specific IgE were not altered, which was markedly improved by the administration with CB plus AIT. Such effects were maintained only for two months in the patients treated with AIT alone; but maintained more than 12 months in those patients treated with both AIT and CB. CB facilitated AIT to induce IL-10 + B cells (B10 cells) in asthma patients. AIT/CB therapy converted antigen specific B cells to antigen specific regulatory B cells. Butyrate modulated the gene transcription of IgE and IL-10 in the allergen specific B cells. In conclusion, administration of CB can enhance the therapeutic effect of AIT in the treatment of allergic asthma via facilitating generation of B10 cells.

  15. Early appearance of germinal center–derived memory B cells and plasma cells in blood after primary immunization

    Science.gov (United States)

    Blink, Elizabeth J.; Light, Amanda; Kallies, Axel; Nutt, Stephen L.; Hodgkin, Philip D.; Tarlinton, David M.

    2005-01-01

    Immunization with a T cell–dependent antigen elicits production of specific memory B cells and antibody-secreting cells (ASCs). The kinetic and developmental relationships between these populations and the phenotypic forms they and their precursors may take remain unclear. Therefore, we examined the early stages of a primary immune response, focusing on the appearance of antigen-specific B cells in blood. Within 1 wk, antigen-specific B cells appear in the blood with either a memory phenotype or as immunoglobulin (Ig)G1 ASCs expressing blimp-1. The memory cells have mutated VH genes; respond to the chemokine CXCL13 but not CXCL12, suggesting recirculation to secondary lymphoid organs; uniformly express B220; show limited differentiation potential unless stimulated by antigen; and develop independently of blimp-1 expression. The antigen-specific IgG1 ASCs in blood show affinity maturation paralleling that of bone marrow ASCs, raising the possibility that this compartment is established directly by blood-borne ASCs. We find no evidence for a blimp-1–expressing preplasma memory compartment, suggesting germinal center output is restricted to ASCs and B220+ memory B cells, and this is sufficient to account for the process of affinity maturation. PMID:15710653

  16. Impaired TLR9 responses in B cells from patients with systemic lupus erythematosus.

    Science.gov (United States)

    Gies, Vincent; Schickel, Jean-Nicolas; Jung, Sophie; Joublin, Aurélie; Glauzy, Salomé; Knapp, Anne-Marie; Soley, Anne; Poindron, Vincent; Guffroy, Aurélien; Choi, Jin-Young; Gottenberg, Jacques-Eric; Anolik, Jennifer H; Martin, Thierry; Soulas-Sprauel, Pauline; Meffre, Eric; Korganow, Anne-Sophie

    2018-03-08

    B cells play a central role in systemic lupus erythematosus (SLE) pathophysiology but dysregulated pathways leading to a break in B cell tolerance remain unclear. Since Toll-like receptor 9 (TLR9) favors the elimination of autoreactive B cells in the periphery, we assessed TLR9 function in SLE by analyzing the responses of B cells and plasmacytoid dendritic cells (pDCs) isolated from healthy donors and patients after stimulation with CpG, a TLR9 agonist. We found that SLE B cells from patients without hydroxychloroquine treatment displayed defective in vitro TLR9 responses, as illustrated by the impaired upregulation of B cell activation molecules and the diminished production of various cytokines including antiinflammatory IL-10. In agreement with CD19 controlling TLR9 responses in B cells, decreased expression of the CD19/CD21 complex on SLE B cells was detected as early as the transitional B cell stage. In contrast, TLR7 function was preserved in SLE B cells, whereas pDCs from SLE patients properly responded to TLR9 stimulation, thereby revealing that impaired TLR9 function in SLE was restricted to B cells. We conclude that abnormal CD19 expression and TLR9 tolerogenic function in SLE B cells may contribute to the break of B cell tolerance in these patients.

  17. CD47 limits antibody dependent phagocytosis against non-malignant B cells.

    Science.gov (United States)

    Gallagher, Sandra; Turman, Sean; Lekstrom, Kristen; Wilson, Susan; Herbst, Ronald; Wang, Yue

    2017-05-01

    Recent studies have demonstrated the importance of CD47 in protecting malignant B cells from antibody dependent cellular phagocytosis (ADCP). Combined treatment of anti-CD47 and -CD20 antibodies synergistically augment elimination of tumor B cells in xenograft mouse models. This has led to the development of novel reagents that can potentially enhance killing of malignant B cells in patients. B cell depleting therapy is also a promising treatment for autoimmune patients. In the current study, we aimed to investigate whether or not CD47 protects non-malignant B cells from ADCP. We show that CD47 is expressed on all B cells in mice, with the highest level on plasma cells in bone marrow and spleen. Although its expression is dispensable for B cell development in mice, CD47 on B cells limits antibody mediated phagocytosis. B cell depletion following in vivo anti-CD19 treatment is more efficient in CD47-/- mice than in wild type mice. In vitro, both naïve and activated B cells from CD47-/- mice are more sensitive to ADCP than wild type B cells. Lastly, we show in an ADCP assay that blocking CD47 can enhance anti-CD19 antibody mediated phagocytosis of wild type B cells. These results suggest that in addition to its already demonstrated benefit in cancer, targeting CD47 may be used as an adjunct in combination with B cell depletion antibodies for treatment of autoimmune diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Downregulation of B-cell lymphoma/leukemia-2 by overexpressed microRNA 34a enhanced titanium dioxide nanoparticle-induced autophagy in BEAS-2B cells

    Science.gov (United States)

    Bai, Wenlin; Chen, Yujiao; Sun, Pengling; Gao, Ai

    2016-01-01

    Titanium dioxide (TiO2) nanoparticles (TNPs) are manufactured worldwide for a wide range of applications and the toxic effect of TNPs on biological systems is gaining attention. Autophagy is recognized as an emerging toxicity mechanism triggered by nanomaterials. MicroRNA 34a (miR34a) acts as a tumor suppressor gene by targeting many oncogenes, but how it affects autophagy induced by TNPs is not completely understood. Here, we observed the activation of TNP-induced autophagy through monodansylcadaverine staining and LC3-I/LC3-II conversion. Meanwhile, the transmission electron microscope ultrastructural analysis showed typical morphological characteristics in autophagy process. We detected the expression of miR34a and B-cell lymphoma/leukemia-2 (Bcl-2). In addition, the underlying mechanism of TNP-induced autophagy was performed using overexpression of miR34a by lentivirus vector transfection. Results showed that TNPs induced autophagy generation evidently. Typical morphological changes in the process of autophagy were observed by the transmission electron microscope ultrastructural analysis and LC3-I/LC3-II conversion increased significantly in TNP-treated cells. Meanwhile, TNPs induced the downregulation of miR34a and increased the expression of Bcl-2. Furthermore, overexpressed miR34a decreased the expression of Bcl-2 both in messenger RNA and protein level, following which the level of autophagy and cell death rate increased after the transfected cells were incubated with TNPs for 24 hours. These findings provide the first evidence that overexpressed miR34a enhanced TNP-induced autophagy and cell death through targeted downregulation of Bcl-2 in BEAS-2B cells. PMID:27226226

  19. Combined heterozygous loss of Ebf1 and Pax5 allows for T-lineage conversion of B cell progenitors.

    Science.gov (United States)

    Ungerbäck, Jonas; Åhsberg, Josefine; Strid, Tobias; Somasundaram, Rajesh; Sigvardsson, Mikael

    2015-06-29

    To investigate how transcription factor levels impact B-lymphocyte development, we generated mice carrying transheterozygous mutations in the Pax5 and Ebf1 genes. Whereas combined reduction of Pax5 and Ebf1 had minimal impact on the development of the earliest CD19(+) progenitors, these cells displayed an increased T cell potential in vivo and in vitro. The alteration in lineage fate depended on a Notch1-mediated conversion process, whereas no signs of de-differentiation could be detected. The differences in functional response to Notch signaling in Wt and Pax5(+/-)Ebf1(+/-) pro-B cells were reflected in the transcriptional response. Both genotypes responded by the generation of intracellular Notch1 and activation of a set of target genes, but only the Pax5(+/-)Ebf1(+/-) pro-B cells down-regulated genes central for the preservation of stable B cell identity. This report stresses the importance of the levels of transcription factor expression during lymphocyte development, and suggests that Pax5 and Ebf1 collaborate to modulate the transcriptional response to Notch signaling. This provides an insight on how transcription factors like Ebf1 and Pax5 preserve cellular identity during differentiation. © 2015 Ungerbäck et al.

  20. High-dimensional assessment of B-cell responses to quadrivalent meningococcal conjugate and plain polysaccharide vaccine.

    Science.gov (United States)

    O'Connor, Daniel; Clutterbuck, Elizabeth A; Thompson, Amber J; Snape, Matthew D; Ramasamy, Maheshi N; Kelly, Dominic F; Pollard, Andrew J

    2017-01-30

    Neisseria meningitidis is a globally important cause of meningitis and septicaemia. Twelve capsular groups of meningococci are known, and quadrivalent vaccines against four of these (A, C, W and Y) are available as plain-polysaccharide and protein-polysaccharide conjugate vaccines. Here we apply contemporary methods to describe B-cell responses to meningococcal polysaccharide and conjugate vaccines. Twenty adults were randomly assigned to receive either a meningococcal plain-polysaccharide or conjugate vaccine; one month later all received the conjugate vaccine. Blood samples were taken pre-vaccination and 7, 21 and 28 days after vaccination; B-cell responses were assessed by ELISpot, serum bactericidal assay, flow cytometry and gene expression microarray. Seven days after an initial dose of either vaccine, a gene expression signature characteristic of plasmablasts was detectable. The frequency of newly generated plasma cells (CXCR3 + HLA-DR + ) and the expression of transcripts derived from IGKC and IGHG2 correlated with immunogenicity. Notably, using an independent dataset, the expression of glucosamine (N-acetyl)-6-sulfatase was found to reproducibly correlate with the magnitude of immune response. Transcriptomic and flow cytometric data revealed depletion of switched memory B cells following plain-polysaccharide vaccine. These data describe distinct gene signatures associated with the production of high-avidity antibody and a plain-polysaccharide-specific signature, possibly linked to polysaccharide-induced hyporesponsiveness.

  1. Persistence and selection of an expanded B-cell clone in the setting of rituximab therapy for Sjögren’s syndrome

    Science.gov (United States)

    2014-01-01

    Introduction Subjects with primary Sjögren’s syndrome (SjS) have an increased risk of developing B-cell lymphoma and may harbor monoclonal B-cell expansions in the peripheral blood. Expanded B-cell clones could be pathogenic, and their persistence could exacerbate disease or predispose toward the development of lymphoma. Therapy with anti-CD20 (rituximab) has the potential to eliminate expanded B-cell clones and thereby potentially ameliorate disease. This study was undertaken to identify and track expanded B-cell clones in the blood of subjects with primary SjS who were treated with rituximab. Methods To determine whether circulating B-cell clones in subjects with primary SjS emerge or remain after B cell-depleting therapy with rituximab, we studied the antibody heavy-chain repertoire. We performed single-memory B-cell and plasmablast sorting and antibody heavy-chain sequencing in six rituximab-treated SjS subjects over the course of a 1-year follow-up period. Results Expanded B-cell clones were identified in four out of the six rituximab-treated SjS subjects, based upon the independent amplification of sequences with identical or highly similar VH, DH, and JH gene segments. We identified one SjS subject with a large expanded B-cell clone that was present prior to therapy and persisted after therapy. Somatic mutations in the clone were numerous but did not increase in frequency over the course of the 1-year follow-up, suggesting that the clone had been present for a long period of time. Intriguingly, a majority of the somatic mutations in the clone were silent, suggesting that the clone was under chronic negative selection. Conclusions For some subjects with primary SjS, these data show that (a) expanded B-cell clones are readily identified in the peripheral blood, (b) some clones are not eliminated by rituximab, and (c) persistent clones may be under chronic negative selection or may not be antigen-driven. The analysis of sequence variation among members of an

  2. Persistence and selection of an expanded B-cell clone in the setting of rituximab therapy for Sjögren's syndrome.

    Science.gov (United States)

    Hershberg, Uri; Meng, Wenzhao; Zhang, Bochao; Haff, Nancy; St Clair, E William; Cohen, Philip L; McNair, Patrice D; Li, Ling; Levesque, Marc C; Luning Prak, Eline T

    2014-02-11

    Subjects with primary Sjögren's syndrome (SjS) have an increased risk of developing B-cell lymphoma and may harbor monoclonal B-cell expansions in the peripheral blood. Expanded B-cell clones could be pathogenic, and their persistence could exacerbate disease or predispose toward the development of lymphoma. Therapy with anti-CD20 (rituximab) has the potential to eliminate expanded B-cell clones and thereby potentially ameliorate disease. This study was undertaken to identify and track expanded B-cell clones in the blood of subjects with primary SjS who were treated with rituximab. To determine whether circulating B-cell clones in subjects with primary SjS emerge or remain after B cell-depleting therapy with rituximab, we studied the antibody heavy-chain repertoire. We performed single-memory B-cell and plasmablast sorting and antibody heavy-chain sequencing in six rituximab-treated SjS subjects over the course of a 1-year follow-up period. Expanded B-cell clones were identified in four out of the six rituximab-treated SjS subjects, based upon the independent amplification of sequences with identical or highly similar VH, DH, and JH gene segments. We identified one SjS subject with a large expanded B-cell clone that was present prior to therapy and persisted after therapy. Somatic mutations in the clone were numerous but did not increase in frequency over the course of the 1-year follow-up, suggesting that the clone had been present for a long period of time. Intriguingly, a majority of the somatic mutations in the clone were silent, suggesting that the clone was under chronic negative selection. For some subjects with primary SjS, these data show that (a) expanded B-cell clones are readily identified in the peripheral blood, (b) some clones are not eliminated by rituximab, and (c) persistent clones may be under chronic negative selection or may not be antigen-driven. The analysis of sequence variation among members of an expanded clone may provide a novel means

  3. Interleukin-35 induces regulatory B cells that suppress autoimmune disease.

    Science.gov (United States)

    Wang, Ren-Xi; Yu, Cheng-Rong; Dambuza, Ivy M; Mahdi, Rashid M; Dolinska, Monika B; Sergeev, Yuri V; Wingfield, Paul T; Kim, Sung-Hye; Egwuagu, Charles E

    2014-06-01

    Interleukin-10 (IL-10)-producing regulatory B (Breg) cells suppress autoimmune disease, and increased numbers of Breg cells prevent host defense to infection and promote tumor growth and metastasis by converting resting CD4(+) T cells to regulatory T (Treg) cells. The mechanisms mediating the induction and development of Breg cells remain unclear. Here we show that IL-35 induces Breg cells and promotes their conversion to a Breg subset that produces IL-35 as well as IL-10. Treatment of mice with IL-35 conferred protection from experimental autoimmune uveitis (EAU), and mice lacking IL-35 (p35 knockout (KO) mice) or defective in IL-35 signaling (IL-12Rβ2 KO mice) produced less Breg cells endogenously or after treatment with IL-35 and developed severe uveitis. Adoptive transfer of Breg cells induced by recombinant IL-35 suppressed EAU when transferred to mice with established disease, inhibiting pathogenic T helper type 17 (TH17) and TH1 cells while promoting Treg cell expansion. In B cells, IL-35 activates STAT1 and STAT3 through the IL-35 receptor comprising the IL-12Rβ2 and IL-27Rα subunits. As IL-35 also induced the conversion of human B cells into Breg cells, these findings suggest that IL-35 may be used to induce autologous Breg and IL-35(+) Breg cells and treat autoimmune and inflammatory disease.

  4. Engaging the lysosomal compartment to combat B cell malignancies

    DEFF Research Database (Denmark)

    Gronbaek, K.; Jaattela, M.

    2009-01-01

    The combination of rituximab, a type I anti-CD20 mAb, with conventional chemotherapy has significantly improved the outcome of patients with B cell malignancies. Regardless of this success, many patients still relapse with therapy-resistant disease, highlighting the need for the development of mAbs...... with higher capacity to induce programmed cell death. The so-called type II anti-CD20 mAbs (e.g., tositumomab) that trigger caspase-independent B cell lymphoma cell death in vitro and show superior efficacy as compared with rituximab in eradicating target cells in mouse models are emerging as the next...... generation of therapeutic anti-CD20 mAbs. In this issue of the JCI, Ivanov and colleagues identify the lysosomal compartment as a target for type II mAbs (see the related article beginning on page 2143). These data encourage the further clinical development of type II mAbs as well as other lysosome...

  5. Primary intravascular large B-cell lymphoma of pituitary

    Directory of Open Access Journals (Sweden)

    K R Anila

    2012-01-01

    Full Text Available A 68-year-old retired nurse, who was a known hypertensive on medication, presented with prolonged fever of 2-month duration without any clinical evidence of infection. On examination she had altered mental status. She also had other nonspecific complaints such as sleep disturbances, loss of weight, etc. On investigation, she was found to have anemia, thrombocytopenia, raised erythrocyte sedimentation rate (ESR, C-reactive protein (CRP, and lactate dehydrogenase (LDH values. She also had electrolyte imbalance. Radiological evaluation of brain showed mass lesion in the sella turcica, suggestive of pituitary adenoma. Biochemical evaluation showed hypopituitarism. Trans-sphenoidal biopsy was done. Based on histopathological and immunohistochemical findings a diagnosis of intravascular large B-cell lymphoma (IVLBCL of pituitary was made. Our patient′s condition deteriorated rapidly and she succumbed to her illness before therapy could be initiated. We are reporting this case because of the rare subtype of large B-cell lymphoma presenting at an extremely unusual primary site.

  6. Modulation of B-cell receptor and microenvironment signaling by a guanine exchange factor in B-cell malignancies

    International Nuclear Information System (INIS)

    Liao, Wei; Sharma, Sanjai

    2016-01-01

    Objective: Chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) cells over-express a guanine exchange factor (GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods: N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor (BCR) and chemokine signaling pathways were compared in the Rasgrf-1 over-expressing and a control transfected cell line. Results: Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions: This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells

  7. RAG-mediated DNA double-strand breaks activate a cell type–specific checkpoint to inhibit pre–B cell receptor signals

    Science.gov (United States)

    Bednarski, Jeffrey J.; Pandey, Ruchi; Schulte, Emily; White, Lynn S.; Chen, Bo-Ruei; Sandoval, Gabriel J.; Kohyama, Masako; Haldar, Malay; Nickless, Andrew; Trott, Amanda; Cheng, Genhong; Murphy, Kenneth M.; Bassing, Craig H.; Payton, Jacqueline E.

    2016-01-01

    DNA double-strand breaks (DSBs) activate a canonical DNA damage response, including highly conserved cell cycle checkpoint pathways that prevent cells with DSBs from progressing through the cell cycle. In developing B cells, pre–B cell receptor (pre–BCR) signals initiate immunoglobulin light (Igl) chain gene assembly, leading to RAG-mediated DNA DSBs. The pre–BCR also promotes cell cycle entry, which could cause aberrant DSB repair and genome instability in pre–B cells. Here, we show that RAG DSBs inhibit pre–BCR signals through the ATM- and NF-κB2–dependent induction of SPIC, a hematopoietic-specific transcriptional repressor. SPIC inhibits expression of the SYK tyrosine kinase and BLNK adaptor, resulting in suppression of pre–BCR signaling. This regulatory circuit prevents the pre–BCR from inducing additional Igl chain gene rearrangements and driving pre–B cells with RAG DSBs into cycle. We propose that pre–B cells toggle between pre–BCR signals and a RAG DSB-dependent checkpoint to maintain genome stability while iteratively assembling Igl chain genes. PMID:26834154

  8. Impairment of mature B-cell maintenance upon combined deletion of the alternative NF-?B transcription factors RELB and NF-?B2 in B cells$

    OpenAIRE

    De Silva, Nilushi S.; Silva, Kathryn; Anderson, Michael M.; Bhagat, Govind; Klein, Ulf

    2016-01-01

    B-cell activating factor (BAFF) is critical for the survival and maturation of mature B-cells. BAFF, via the BAFF receptor (BAFFR), activates multiple signaling pathways in B-cells, including the alternative nuclear factor-?B (NF-?B) pathway. The transcription factors RELB and NF-?B2 (p100/p52) are the downstream mediators of the alternative pathway; however, the B-cell-intrinsic functions of these NF-?B subunits have not been studied in vivo using conditional alleles, either individually or ...

  9. Isolation and characterization of an HIV-1 envelope glycoprotein-specific B-cell from an immortalized human naïve B-cell library.

    Science.gov (United States)

    Sun, Zehua; Lu, Shiqiang; Yang, Zheng; Li, Jingjing; Zhang, Meiyun

    2017-04-01

    With the recent development of single B-cell cloning techniques, an increasing number of human immunodeficiency virus type 1 (HIV-1)-specific broadly neutralizing antibodies have been isolated since 2009. However, knowledge regarding HIV-1-specific B cells in vivo is limited. In this study, an HIV-1-specific B-cell line was established using healthy PBMC donors by the highly efficient Epstein-Barr virus transformation method to generate immortalized human naïve B-cell libraries. The enrichment of HIV-1 envelope-specific B cells was observed after four rounds of cell panning with the HIV-1 envelope glycoprotein. An HIV-1 envelope-specific stable B-cell line (LCL-P4) was generated. Although this cell line acquired a lymphoblastic phenotype, no expression was observed for activation-induced cytidine deaminase, an enzyme responsible for initiating somatic hypermutation and class switch recombination in B cells. This study describes a method that enables fast isolation of HIV-1-specific B cells, and this approach may extend to isolating other B-cell-specific antigens for further experiments.

  10. High expression of LMO2 in Hodgkin, Burkitt and germinal center diffuse large B cell lymphomas

    International Nuclear Information System (INIS)

    Shams, T.M.

    2011-01-01

    The LMO 2 gene encodes a transcription factor that regulates key events in erythropoiesis, angio genesis, and embryogenesis and is highly expressed at the most immature stages of lymphopoiesis. Its implication in Hodgkin lymphoma (HL), Burkitt lymphoma (BL) and diffuse large B cell lymphoma (DLBCL) is limited in the literature. Material and methods: An immunohistochemical study was performed on 68 lymphoma specimens showing different types including Hodgkin lymphoma (23), Burkitt lymphoma (10) and diffuse large B cell lymphoma (35). Also, seven specimens of the reactive nodal tissue were included as control. A monoclonal anti-human antibody has been used to detect LMO 2 . Results: LMO 2 was detected in all cases of HL (100%), in nine cases of BL (90%) and in all cases of DLBCL of germinal center (GC) subtype 20/35 (57.1%) but is completely negative in non-germinal center (NGC) DLBCL. In normal control of reactive nodes, LMO 2 was expressed in germinal center area but not expressed in other areas including mantle, marginal, or T cell zones. In DLBCL; there was no statistically significant relation between LMO 2 positive cases and the studied clinico pathological parameters including patient's age, sex and tumor site, stage and histological subtype. On the other hand, it was statistically significant regarding immuno phenotyping of GC versus N GC. Conclusions: LMO 2 expression is a special feature of GC DLBCL which can be used as a diagnostic marker and therapeutic target. Further studies regarding its prognostic role in patients are recommended.

  11. Transcription factor networks in B-cell differentiation link development to acute lymphoid leukemia.

    Science.gov (United States)

    Somasundaram, Rajesh; Prasad, Mahadesh A J; Ungerbäck, Jonas; Sigvardsson, Mikael

    2015-07-09

    B-lymphocyte development in the bone marrow is controlled by the coordinated action of transcription factors creating regulatory networks ensuring activation of the B-lymphoid program and silencing of alternative cell fates. This process is tightly connected to malignant transformation because B-lineage acute lymphoblastic leukemia cells display a pronounced block in differentiation resulting in the expansion of immature progenitor cells. Over the last few years, high-resolution analysis of genetic changes in leukemia has revealed that several key regulators of normal B-cell development, including IKZF1, TCF3, EBF1, and PAX5, are genetically altered in a large portion of the human B-lineage acute leukemias. This opens the possibility of directly linking the disrupted development as well as aberrant gene expression patterns in leukemic cells to molecular functions of defined transcription factors in normal cell differentiation. This review article focuses on the roles of transcription factors in early B-cell development and their involvement in the formation of human leukemia. © 2015 by The American Society of Hematology.

  12. The BCL6 RD2 Domain Governs Commitment of Activated B Cells to Form Germinal Centers

    Directory of Open Access Journals (Sweden)

    Chuanxin Huang

    2014-09-01

    Full Text Available To understand how the Bcl6 transcriptional repressor functions in the immune system, we disrupted its RD2 repression domain in mice. Bcl6RD2MUT mice exhibit a complete loss of germinal center (GC formation but retain normal extrafollicular responses. Bcl6RD2MUT antigen-engaged B cells migrate to the interfollicular zone and interact with cognate T helper cells. However, these cells fail to complete early GC-commitment differentiation and coalesce as nascent GC aggregates. Bcl6 directly binds and represses trafficking receptors S1pr1 and Gpr183 by recruiting Hdac2 through the RD2 domain. Deregulation of these genes impairs B cell migration and may contribute to GC failure in Bcl6RD2MUT mice. The development of functional GC-TFH cells was partially impaired in Bcl6RD2MUT mice. In contrast to Bcl6−/− mice, Bcl6RD2MUT animals experience no inflammatory disease or macrophage deregulation. These results reveal an essential role for RD2 repression in early GC commitment and striking biochemical specificity in Bcl6 control of humoral and innate immune-cell phenotypes.

  13. Quantitative Analysis of Repertoire-Scale Immunoglobulin Properties in Vaccine-Induced B-Cell Responses

    Directory of Open Access Journals (Sweden)

    Ilja V. Khavrutskii

    2017-08-01

    Full Text Available Recent advances in the next-generation sequencing of B-cell receptors (BCRs enable the characterization of humoral responses at a repertoire-wide scale and provide the capability for identifying unique features of immune repertoires in response to disease, vaccination, or infection. Immunosequencing now readily generates 103–105 sequences per sample; however, statistical analysis of these repertoires is challenging because of the high genetic diversity of BCRs and the elaborate clonal relationships among them. To date, most immunosequencing analyses have focused on reporting qualitative trends in immunoglobulin (Ig properties, such as usage or somatic hypermutation (SHM percentage of the Ig heavy chain variable (IGHV gene segment family, and on reducing complex Ig property distributions to simple summary statistics. However, because Ig properties are typically not normally distributed, any approach that fails to assess the distribution as a whole may be inadequate in (1 properly assessing the statistical significance of repertoire differences, (2 identifying how two repertoires differ, and (3 determining appropriate confidence intervals for assessing the size of the differences and their potential biological relevance. To address these issues, we have developed a technique that uses Wilcox’ robust statistics toolbox to identify statistically significant vaccine-specific differences between Ig repertoire properties. The advantage of this technique is that it can determine not only whether but also where the distributions differ, even when the Ig repertoire properties are non-normally distributed. We used this technique to characterize murine germinal center (GC B-cell repertoires in response to a complex Ebola virus-like particle (eVLP vaccine candidate with known protective efficacy. The eVLP-mediated GC B-cell responses were highly diverse, consisting of thousands of clonotypes. Despite this staggering diversity, we identified statistically

  14. Quantitative Analysis of Repertoire-Scale Immunoglobulin Properties in Vaccine-Induced B-Cell Responses.

    Science.gov (United States)

    Khavrutskii, Ilja V; Chaudhury, Sidhartha; Stronsky, Sabrina M; Lee, Donald W; Benko, Jacqueline G; Wallqvist, Anders; Bavari, Sina; Cooper, Christopher L

    2017-01-01

    Recent advances in the next-generation sequencing of B-cell receptors (BCRs) enable the characterization of humoral responses at a repertoire-wide scale and provide the capability for identifying unique features of immune repertoires in response to disease, vaccination, or infection. Immunosequencing now readily generates 10 3 -10 5 sequences per sample; however, statistical analysis of these repertoires is challenging because of the high genetic diversity of BCRs and the elaborate clonal relationships among them. To date, most immunosequencing analyses have focused on reporting qualitative trends in immunoglobulin (Ig) properties, such as usage or somatic hypermutation (SHM) percentage of the Ig heavy chain variable (IGHV) gene segment family, and on reducing complex Ig property distributions to simple summary statistics. However, because Ig properties are typically not normally distributed, any approach that fails to assess the distribution as a whole may be inadequate in (1) properly assessing the statistical significance of repertoire differences, (2) identifying how two repertoires differ, and (3) determining appropriate confidence intervals for assessing the size of the differences and their potential biological relevance. To address these issues, we have developed a technique that uses Wilcox' robust statistics toolbox to identify statistically significant vaccine-specific differences between Ig repertoire properties. The advantage of this technique is that it can determine not only whether but also where the distributions differ, even when the Ig repertoire properties are non-normally distributed. We used this technique to characterize murine germinal center (GC) B-cell repertoires in response to a complex Ebola virus-like particle (eVLP) vaccine candidate with known protective efficacy. The eVLP-mediated GC B-cell responses were highly diverse, consisting of thousands of clonotypes. Despite this staggering diversity, we identified statistically significant

  15. Activated autologous T cells exert an anti-B-cell chronic lymphatic leukemia effect in vitro and in vivo.

    Science.gov (United States)

    Di Ianni, Mauro; Moretti, Lorenzo; Terenzi, Adelmo; Bazzucchi, Federico; Del Papa, Beatrice; Bazzucchi, Moira; Ciurnelli, Raffaella; Lucchesi, Alessandro; Sportoletti, Paolo; Rosati, Emanuela; Marconi, Pier Francesco; Falzetti, Franca; Tabilio, Antonio

    2009-01-01

    The impact of chronic lymphatic leukemia (CLL) tumor burden on the autologous immune system has already been demonstrated. This study attempted to elucidate the molecular mechanisms underlying T-cell immunologic deficiencies in CLL. Freshly isolated CD3(+) T cells from patients with a diagnosis of CLL and healthy donors were analyzed by gene expression profiling. Activated T cells from 20 patients with CLL were tested in vitro for cytotoxicity against mutated and unmutated autologous B cells and DAUDI, K562 and P815 cell lines. To investigate T-cell mediated cytotoxicity in vivo, we co-transplanted OKT3-activated T lymphocytes and autologous B-cell CLL (B-CLL) cells into NOD/SCID mice. Gene expression profiles of peripheral blood T cells from B-CLL patients showed 25 down-regulated, and 31 up-regulated, genes that were mainly involved in cell differentiation, proliferation, survival, apoptosis, cytoskeleton formation, vesicle trafficking and T-cell activation. After culture, the T-cell count remained unchanged, CD8 cells expanded more than CD4 and a cytotoxicity index >30% was present in 5/20 patients. Cytotoxicity against B autologous leukemic cells did not correlate with B-cell mutational status. Only activated T cells exerting cytotoxicity against autologous leukemic B cells prevented CLL in a human-mouse chimera. This study indicates that patients with CLL are affected by a partial immunologic defect that might be somewhat susceptible to repair. This study identifies the molecular pathways underlying T-cell deficiencies in CLL and shows that cytotoxic T-cell functions against autologous B-CLL can be rebuilt at least in part in vitro and in vivo.

  16. Enhanced selection of high affinity DNA-reactive B cells following cyclophosphamide treatment in mice.

    Directory of Open Access Journals (Sweden)

    Daisuke Kawabata

    2010-01-01

    Full Text Available A major goal for the treatment of patients with systemic lupus erythematosus with cytotoxic therapies is the induction of long-term remission. There is, however, a paucity of information concerning the effects of these therapies on the reconstituting B cell repertoire. Since there is recent evidence suggesting that B cell lymphopenia might attenuate negative selection of autoreactive B cells, we elected to investigate the effects of cyclophosphamide on the selection of the re-emerging B cell repertoire in wild type mice and transgenic mice that express the H chain of an anti-DNA antibody. The reconstituting B cell repertoire in wild type mice contained an increased frequency of DNA-reactive B cells; in heavy chain transgenic mice, the reconstituting repertoire was characterized by an increased frequency of mature, high affinity DNA-reactive B cells and the mice expressed increased levels of serum anti-DNA antibodies. This coincided with a significant increase in serum levels of BAFF. Treatment of transgene-expressing mice with a BAFF blocking agent or with DNase to reduce exposure to autoantigen limited the expansion of high affinity DNA-reactive B cells during B cell reconstitution. These studies suggest that during B cell reconstitution, not only is negative selection of high affinity DNA-reactive B cells impaired by increased BAFF, but also that B cells escaping negative selection are positively selected by autoantigen. There are significant implications for therapy.

  17. File list: ALL.Bld.05.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.05.AllAg.Lymphoma,_B-Cell hg19 All antigens Blood Lymphoma, B-Cell SRX37034...351,SRX092415,SRX370350,SRX092417,SRX092414 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.05.AllAg.Lymphoma,_B-Cell.bed ...

  18. File list: ALL.Bld.50.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.50.AllAg.Lymphoma,_B-Cell hg19 All antigens Blood Lymphoma, B-Cell SRX37034...349,SRX370351,SRX370345,SRX092415,SRX092417 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.50.AllAg.Lymphoma,_B-Cell.bed ...

  19. File list: His.Bld.10.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.10.AllAg.Lymphoma,_B-Cell hg19 Histone Blood Lymphoma, B-Cell SRX370346,SRX...370340,SRX370344,SRX370342,SRX370348,SRX370350 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Bld.10.AllAg.Lymphoma,_B-Cell.bed ...

  20. File list: His.Bld.50.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.50.AllAg.Lymphoma,_B-Cell hg19 Histone Blood Lymphoma, B-Cell SRX370346,SRX...370350,SRX370344,SRX370342,SRX370348,SRX370340 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Bld.50.AllAg.Lymphoma,_B-Cell.bed ...

  1. File list: Oth.Bld.50.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Bld.50.AllAg.Lymphoma,_B-Cell hg19 TFs and others Blood Lymphoma, B-Cell SRX092...416,SRX092414 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Bld.50.AllAg.Lymphoma,_B-Cell.bed ...

  2. File list: Oth.Bld.20.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Bld.20.AllAg.Lymphoma,_B-Cell hg19 TFs and others Blood Lymphoma, B-Cell SRX092...416,SRX092414 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Bld.20.AllAg.Lymphoma,_B-Cell.bed ...

  3. File list: Oth.Bld.05.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Bld.05.AllAg.Lymphoma,_B-Cell hg19 TFs and others Blood Lymphoma, B-Cell SRX092...416,SRX092414 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Bld.05.AllAg.Lymphoma,_B-Cell.bed ...

  4. File list: ALL.Bld.10.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.10.AllAg.Lymphoma,_B-Cell hg19 All antigens Blood Lymphoma, B-Cell SRX37034...416,SRX092414,SRX370350,SRX092417,SRX092415 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.10.AllAg.Lymphoma,_B-Cell.bed ...

  5. File list: His.Bld.05.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.05.AllAg.Lymphoma,_B-Cell hg19 Histone Blood Lymphoma, B-Cell SRX370346,SRX...370344,SRX370340,SRX370342,SRX370348,SRX370350 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Bld.05.AllAg.Lymphoma,_B-Cell.bed ...

  6. File list: Oth.Bld.10.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Bld.10.AllAg.Lymphoma,_B-Cell hg19 TFs and others Blood Lymphoma, B-Cell SRX092...416,SRX092414 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Bld.10.AllAg.Lymphoma,_B-Cell.bed ...

  7. File list: ALL.Bld.20.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.20.AllAg.Lymphoma,_B-Cell hg19 All antigens Blood Lymphoma, B-Cell SRX37034...348,SRX370345,SRX092417,SRX370351,SRX092415 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.20.AllAg.Lymphoma,_B-Cell.bed ...

  8. File list: His.Bld.20.AllAg.Lymphoma,_B-Cell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.20.AllAg.Lymphoma,_B-Cell hg19 Histone Blood Lymphoma, B-Cell SRX370346,SRX...370340,SRX370344,SRX370350,SRX370342,SRX370348 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Bld.20.AllAg.Lymphoma,_B-Cell.bed ...

  9. Monovalent engagement of the BCR activates ovalbumin-specific transnuclear B cells

    NARCIS (Netherlands)

    Avalos, Ana M.; Bilate, Angelina M.; Witte, Martin D.; Tai, Albert K.; He, Jiang; Frushicheva, Maria P.; Thill, Peter D.; Meyer-Wentrup, Friederike; Theile, Christopher S.; Chakraborty, Arup K.; Zhuang, Xiaowei; Ploegh, Hidde L.

    2014-01-01

    Valency requirements for B cell activation upon antigen encounter are poorly understood. OB1 transnuclear B cells express an IgG1 B cell receptor (BCR) specific for ovalbumin (OVA), the epitope of which can be mimicked using short synthetic peptides to allow antigen-specific engagement of the BCR.

  10. Molecular characterization of neoplastic and normal "sister" lymphoblastoid B-cell lines from chronic lymphocytic leukemia

    DEFF Research Database (Denmark)

    Lanemo Myhrinder, Anna; Hellqvist, Eva; Bergh, Ann-Charlotte

    2013-01-01

    Chronic lymphocytic leukemia (CLL) B-cells resemble self-renewing CD5 + B-cells carrying auto/xeno-antigen-reactive B-cell receptors (BCRs) and multiple innate pattern-recognition receptors, such as Toll-like receptors and scavenger receptors. Integration of signals from BCRs with multiple surface...

  11. File list: ALL.Bld.20.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.20.AllAg.Pro-B_cells mm9 All antigens Blood Pro-B cells SRX1553109,SRX15531...3,SRX1143907 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Bld.20.AllAg.Pro-B_cells.bed ...

  12. File list: His.Bld.20.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.20.AllAg.Pro-B_cells mm9 Histone Blood Pro-B cells SRX668836,SRX1184113,SRX...9,SRX1143910,SRX1143916,SRX1143902 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Bld.20.AllAg.Pro-B_cells.bed ...

  13. File list: His.Bld.50.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.50.AllAg.Pro-B_cells mm9 Histone Blood Pro-B cells SRX668836,SRX1184113,SRX...09,SRX759800,SRX1143916,SRX1143902 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Bld.50.AllAg.Pro-B_cells.bed ...

  14. Monocytes mediate shaving of B-cell-bound anti-CD20 antibodies

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Jungersen, Mette B; Pedersen, Charlotte D

    2011-01-01

    complex from the B-cell surface. Here, we confirm, that in vitro co-culture of human monocytes and RTX-labelled syngeneic B cells results in reduced expression of CD20/RTX complex on the B cell surface. This shaving mechanism was the result of active protease activity because EDTA and PMSF were able...

  15. B cells expressing IL-10 mRNA modulate memory T cells after DNA-Hsp65 immunization.

    Science.gov (United States)

    Fontoura, I C; Trombone, A P F; Almeida, L P; Lorenzi, J C C; Rossetti, R A M; Malardo, T; Padilha, E; Schluchting, W; Silva, R L L; Gembre, A F; Fiuza, J E C; Silva, C L; Panunto-Castelo, A; Coelho-Castelo, A A M

    2015-12-01

    In DNA vaccines, the gene of interest is cloned into a bacterial plasmid that is engineered to induce protein production for long periods in eukaryotic cells. Previous research has shown that the intramuscular immunization of BALB/c mice with a naked plasmid DNA fragment encoding the Mycobacterium leprae 65-kDa heat-shock protein (pcDNA3-Hsp65) induces protection against M. tuberculosis challenge. A key stage in the protective immune response after immunization is the generation of memory T cells. Previously, we have shown that B cells capture plasmid DNA-Hsp65 and thereby modulate the formation of CD8+ memory T cells after M. tuberculosis challenge in mice. Therefore, clarifying how B cells act as part of the protective immune response after DNA immunization is important for the development of more-effective vaccines. The aim of this study was to investigate the mechanisms by which B cells modulate memory T cells after DNA-Hsp65 immunization. C57BL/6 and BKO mice were injected three times, at 15-day intervals, with 100 µg naked pcDNA-Hsp65 per mouse. Thirty days after immunization, the percentages of effector memory T (TEM) cells (CD4+ and CD8+/CD44high/CD62Llow) and memory CD8+ T cells (CD8+/CD44high/CD62Llow/CD127+) were measured with flow cytometry. Interferon γ, interleukin 12 (IL-12), and IL-10 mRNAs were also quantified in whole spleen cells and purified B cells (CD43-) with real-time qPCR. Our data suggest that a B-cell subpopulation expressing IL-10 downregulated proinflammatory cytokine expression in the spleen, increasing the survival of CD4+ TEM cells and CD8+ TEM/CD127+ cells.

  16. Chronic rhinosinusitis with nasal polyps is characterized by B-cell inflammation and EBV-induced protein 2 expression

    Science.gov (United States)

    Hulse, Kathryn E.; Norton, James E.; Suh, Lydia; Zhong, Qiu; Mahdavinia, Mahboobeh; Simon, Patrick; Kern, Robert C.; Conley, David B.; Chandra, Rakesh K.; Tan, Bruce K.; Peters, Anju T.; Grammer, Leslie C.; Harris, Kathleen E.; Carter, Roderick G.; Kato, Atsushi; Schleimer, Robert P.

    2013-01-01

    Background Despite the high prevalence and morbidity of chronic rhinosinusitis (CRS), little is known about the mechanisms that underlie its pathogenesis. Recent studies have suggested that B cells might play an important role in CRS. Objective We sought to thoroughly characterize B lineage cells within sinus tissues of patients with CRS and healthy control subjects and to determine whether levels of EBV-induced protein 2, which is known to play an important role in the development of B-cell responses, were increased in patients with CRS. Methods Cells isolated from sinus tissues of patients with CRS and healthy control subjects were characterized by means of flow cytometry and immunohistochemistry. Local production of antibodies was measured in tissue extracts, nasal lavage fluid, and sera by using multiplex bead arrays and ELISA. Quantitative RT-PCR, ELISA, and Western blotting were used to assess gene and protein expression from tissue extracts. Results Nasal polyps (NPs) from patients with CRS had increased levels of both B cells and plasma cells compared with uncinate tissue from healthy control subjects (P < .05). NPs also contained significantly increased levels of several antibody isotypes compared with normal uncinate tissue (P < .05), but no differences in circulating antibody levels were found. Interestingly, levels of EBV-induced protein 2 were also increased in NPs (P < .05) and were positively correlated with expression of plasma cell markers (CD138 and B lymphocyte–induced maturation protein) in sinus tissue. Conclusion B cells and plasma cells are enriched in NPs, actively produce antibodies locally, and might contribute to chronic inflammation in patients with CRS. Elucidating the mechanisms that underlie this excessive local B-cell response might provide novel insights for the development of improved therapeutic strategies. PMID:23473835

  17. The regulatory network of B-cell differentiation: a focused view of early B-cell factor 1 function.

    Science.gov (United States)

    Boller, Sören; Grosschedl, Rudolf

    2014-09-01

    During the last decades, many studies have investigated the transcriptional and epigenetic regulation of lineage decision in the hematopoietic system. These efforts led to a model in which extrinsic signals and intrinsic cues establish a permissive chromatin context upon which a regulatory network of transcription factors and epigenetic modifiers act to guide the differentiation of hematopoietic lineages. These networks include lineage-specific factors that further modify the epigenetic landscape and promote the generation of specific cell types. The process of B lymphopoiesis requires a set of transcription factors, including Ikaros, PU.1, E2A, and FoxO1 to 'prime' cis-regulatory regions for subsequent activation by the B-lineage-specific transcription factors EBF1 and Pax-5. The expression of EBF1 is initiated by the combined action of E2A and FoxO1, and it is further enhanced and maintained by several positive feedback loops that include Pax-5 and IL-7 signaling. EBF1 acts in concert with Ikaros, PU.1, Runx1, E2A, FoxO1, and Pax-5 to establish the B cell-specific transcription profile. EBF1 and Pax-5 also collaborate to repress alternative cell fates and lock cells into the B-lineage fate. In addition to the functions of EBF1 in establishing and maintaining B-cell identity, EBF1 is required to coordinate differentiation with cell proliferation and survival. © 2014 The Authors. Immunological Reviews Published by John Wiley & Sons Ltd.

  18. 2B4-SAP signaling is required for the priming of naive CD8+T cells by antigen-expressing B cells and B lymphoma cells.

    Science.gov (United States)

    Huang, Yu-Hsuan; Tsai, Kevin; Tan, Sara Y; Kang, Sohyeong; Ford, Mandy L; Harder, Kenneth W; Priatel, John J

    2017-01-01

    Mutations in SH2D1A gene that encodes SAP (SLAM-associated protein) result in X-linked lymphoproliferative disease (XLP), a rare primary immunodeficiency disease defined by exquisite sensitivity to the B-lymphotropic Epstein-Barr virus (EBV) and B cell lymphomas. However, the precise mechanism of how the loss of SAP function contributes to extreme vulnerability to EBV and the development of B cell lymphomas remains unclear. Here, we investigate the hypothesis that SAP is critical for CD8 + T cell immune surveillance of antigen (Ag)-expressing B cells or B lymphoma cells under conditions of defined T cell receptor (TCR) signaling. Sh2d1a - / - CD8 + T cells exhibited greatly diminished proliferation relative to wild type when Ag-presenting-B cells or -B lymphoma cells served as the primary Ag-presenting cell (APC). By contrast, Sh2d1a - / - CD8 + T cells responded equivalently to wild-type CD