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Sample records for b-cell translocation gene

  1. Candidate tumor suppressor B-cell translocation gene 3 impedes neoplastic progression by suppression of AKT

    PubMed Central

    Cheng, Y-C; Chen, P-H; Chiang, H-Y; Suen, C-S; Hwang, M-J; Lin, T-Y; Yang, H-C; Lin, W-C; Lai, P-L; Shieh, S-Y

    2015-01-01

    BTG3 (B-cell translocation gene 3) is a p53 target that also binds and inhibits E2F1. Although it connects two major growth-regulatory pathways functionally and is downregulated in human cancers, whether and how BTG3 acts as a tumor suppressor remain largely uncharacterized. Here we present evidence that BTG3 binds and suppresses AKT, a kinase frequently deregulated in cancers. BTG3 ablation results in increased AKT activity that phosphorylates and inhibits glycogen synthase kinase 3?. Consequently, we also observed elevated ?-catenin/T-cell factor activity, upregulation of mesenchymal markers, and enhanced cell migration. Consistent with these findings, BTG3 overexpression suppressed tumor growth in mouse xenografts, and was associated with diminished AKT phosphorylation and reduced ?-catenin in tissue specimens. Significantly, a short BTG3-derived peptide was identified, which recapitulates these effects in vitro and in cells. Thus, our study provides mechanistic insights into a previously unreported AKT inhibitory pathway downstream of p53. The identification of an AKT inhibitory peptide also unveils a new avenue for cancer therapeutics development. PMID:25569101

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

    PubMed Central

    Kamran, Shawana; Raca, Gordana; Nazir, Kamran

    2015-01-01

    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. PMID:26600955

  3. Messenger RNA levels of five genes located at chromosome 11q13 in B-cell tumors with chromosome translocation t(11;14)(q13;q32).

    PubMed

    Akiyama, N; Tsuruta, H; Sasaki, H; Sakamoto, H; Hamaguchi, M; Ohmura, Y; Seto, M; Ueda, R; Hirai, H; Yazaki, Y

    1994-01-15

    To identify genes activated by chromosome translocation t(11;14)(q13;q32), mRNA levels of five genes (cyclin D1, EXP1, MB38, HST1, and INT2) at chromosome 11q13 were investigated. The cyclin D1 mRNA increased in BCL-1-rearranged B-cell tumor cell lines SP-49, NOP-2, FLAM-76, KMS-12-PE, and KMS-12-BM cells, while it was not detected in cell lines without the translocation, Raji, U266, and HEL cells. A significant amount of the MB38 mRNA was detected irrelevantly to the translocation in all of these cell lines. The mRNAs of EXP1, HST1, and INT2 were undetectable in these cells. The results suggested that the translocation activates cyclin D1 alone, while the mRNA levels of the other four genes are regulated independently of the translocation. PMID:8275473

  4. Upregulation of B-cell translocation gene 2 by epigallocatechin-3-gallate via p38 and ERK signaling blocks cell proliferation in human oral squamous cell carcinoma cells.

    PubMed

    Lee, Jehn-Chuan; Chung, Li-Chuan; Chen, Yu-Jen; Feng, Tsui-Hsia; Chen, Wen-Tsung; Juang, Horng-Heng

    2015-05-01

    Oral squamous cell carcinoma (OSCC) is a well-known malignancy that accounts for the majority of oral cancers. B-cell translocation gene 2 (BTG2) is an important regulator of cell cycle dynamics in cancer cells. However, the role of BTG2 in OSCC cells and the influences of epigallocatechin-3-gallate (EGCG) on BTG2 gene expressions have not been well evaluated. The objectives of this study were to examine the effect of EGCG-induced BTG2 expression and the potential signal pathways involved. The (3)H-thymidine incorporation and Western-blot assays revealed cell proliferation was attenuated by EGCG via upregulation of BTG2 expression causing cell cycle G1 phase arrest in OSCC cells. BTG2 overexpression decreased tumor cell growth, while BTG2 knockdown illuminated the opposite effect in xenograft animal studies. Overexpressed BTG2 arrested the cell cycle at the G1 phase and downregulated protein expressions of cyclin A, cyclin D, and cyclin E. Western-blot assays indicated that EGCG induced phosphorylation of p38, JNK, and ERK. However, pretreatments with selective mitogen-activated protein kinase (MAPK) inhibitors, SB203580 (p38 inhibitor) and PD0325901 (ERK1/2 inhibitor), significantly suppressed the activation of EGCG on BTG2 expression. Our results indicate that EGCG attenuates cell proliferation of OSCC cells by upregulating BTG2 expression via p38 and ERK pathways. PMID:25721086

  5. 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.

    PubMed

    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 ?B 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. PMID:26277595

  6. Developmental propagation of V(D)J recombination-associated DNA breaks and translocations in mature B cells via dicentric chromosomes

    PubMed Central

    Hu, Jiazhi; Tepsuporn, Suprawee; Meyers, Robin M.; Gostissa, Monica; Alt, Frederick W.

    2014-01-01

    Mature IgM+ B-cell lymphomas that arise in certain ataxia telangiectasia-mutated (ATM)-deficient compound mutant mice harbor translocations that fuse V(D)J recombination-initiated IgH double-strand breaks (DSBs) on chromosome 12 to sequences downstream of c-myc on chromosome 15, generating dicentric chromosomes and c-myc amplification via a breakage-fusion-bridge mechanism. As V(D)J recombination DSBs occur in developing progenitor B cells in the bone marrow, we sought to elucidate a mechanism by which such DSBs contribute to oncogenic translocations/amplifications in mature B cells. For this purpose, we applied high-throughput genome-wide translocation sequencing to study the fate of introduced c-myc DSBs in splenic IgM+ B cells stimulated for activation-induced cytidine deaminase (AID)-dependent IgH class switch recombination (CSR). We found frequent translocations of c-myc DSBs to AID-initiated DSBs in IgH switch regions in wild-type and ATM-deficient B cells. However, c-myc also translocated frequently to newly generated DSBs within a 35-Mb region downstream of IgH in ATM-deficient, but not wild-type, CSR-activated B cells. Moreover, we found such DSBs and translocations in activated B cells that did not express AID or undergo CSR. Our findings indicate that ATM deficiency leads to formation of chromosome 12 dicentrics via recombination-activating gene-initiated IgH DSBs in progenitor B cells and that these dicentrics can be propagated developmentally into mature B cells where they generate new DSBs downstream of IgH via breakage-fusion-bridge cycles. We propose that dicentrics formed by joining V(D)J recombination–associated IgH DSBs to DSBs downstream of c-myc in ATM-deficient B lineage cells similarly contribute to c-myc amplification and mature B-cell lymphomas. PMID:24982162

  7. DNA repair genes are selectively mutated in diffuse large B cell lymphomas

    PubMed Central

    de Miranda, Noel FCC; Peng, Roujun; Georgiou, Konstantinos; Wu, Chenglin; Sörqvist, Elin Falk; Berglund, Mattias; Chen, Longyun; Gao, Zhibo; Lagerstedt, Kristina; Lisboa, Susana; Roos, Fredrik; van Wezel, Tom; Teixeira, Manuel R.; Rosenquist, Richard; Sundström, Christer; Enblad, Gunilla; Nilsson, Mats; Zeng, Yixin; Kipling, David

    2013-01-01

    DNA repair mechanisms are fundamental for B cell development, which relies on the somatic diversification of the immunoglobulin genes by V(D)J recombination, somatic hypermutation, and class switch recombination. Their failure is postulated to promote genomic instability and malignant transformation in B cells. By performing targeted sequencing of 73 key DNA repair genes in 29 B cell lymphoma samples, somatic and germline mutations were identified in various DNA repair pathways, mainly in diffuse large B cell lymphomas (DLBCLs). Mutations in mismatch repair genes (EXO1, MSH2, and MSH6) were associated with microsatellite instability, increased number of somatic insertions/deletions, and altered mutation signatures in tumors. Somatic mutations in nonhomologous end-joining (NHEJ) genes (DCLRE1C/ARTEMIS, PRKDC/DNA-PKcs, XRCC5/KU80, and XRCC6/KU70) were identified in four DLBCL tumors and cytogenetic analyses revealed that translocations involving the immunoglobulin-heavy chain locus occurred exclusively in NHEJ-mutated samples. The novel mutation targets, CHEK2 and PARP1, were further screened in expanded DLBCL cohorts, and somatic as well as novel and rare germline mutations were identified in 8 and 5% of analyzed tumors, respectively. By correlating defects in a subset of DNA damage response and repair genes with genomic instability events in tumors, we propose that these genes play a role in DLBCL lymphomagenesis. PMID:23960188

  8. Chromosomal translocations cause deregulated BCL6 expression by promoter substitution in B cell lymphoma.

    PubMed Central

    Ye, B H; Chaganti, S; Chang, C C; Niu, H; Corradini, P; Chaganti, R S; Dalla-Favera, R

    1995-01-01

    The BCL6 gene codes for a zinc-finger transcription factor and is involved in chromosomal rearrangements in 30-40% of diffuse large-cell lymphoma (DLCL). These rearrangements cluster within the 5' regulatory region of BCL6 spanning its first non-coding exon. To determine the functional consequences of these alterations, we have analyzed the structure of the rearranged BCL6 alleles and their corresponding RNA and protein species in two DLCL biopsies and one tumor cell line which carried the t(3;14)(q27;q32) translocation involving the BCL6 and immunoglobulin heavy-chain (IgH) loci. In all three cases, the breakpoints were mapped within the IgH switch region and the BCL6 first intron, leading to the juxtaposition of part of the IgH locus upstream and in the same transcriptional orientation to the BCL6 coding exons. An analysis of cDNA clones showed that these recombinations generate chimeric IgH-BCL6 transcripts which initiated from IgH germline transcript promoters (I mu or I gamma 3), but retain a normal BCL6 coding domain. In the tumor cell line, the chimeric I gamma 3-BCL6 allele, but not the germline BCL6 gene, was transcriptionally active and produced a normal BCL6 protein. These findings indicate that t(3;14) translocations alter BCL6 expression by promoter substitution and imply that the consequence of these alterations is the deregulated expression of a normal BCL6 protein. Images PMID:8557040

  9. The Immunoglobulin Heavy Chain Gene 3’ Enhancers Induce Bcl2 Deregulation and Lymphomagenesis in Murine B Cells

    PubMed Central

    Xiang, Hong; Noonan, Emily J.; Wang, Jinghong; Duan, Hong; Ma, Lawrence; Michie, Sara; Boxer, Linda M.

    2011-01-01

    Human follicular B-cell lymphoma is associated with the t(14;18) chromosomal translocation that juxtaposes the Bcl2 proto-oncogene with the immunoglobulin heavy chain (Igh) locus, resulting in the deregulated expression of Bcl2. Our previous studies have shown that the Igh 3’ enhancers deregulate Bcl2 expression in vitro. However, the effects of the Igh 3’ enhancer elements on Bcl2 expression in vivo are not known. To investigate the role of the Igh 3’ enhancers in Bcl2 deregulation, we used gene targeting to generate knock-in mice in which four DNase I hypersensitive regions from the murine Igh 3’ region were integrated 3’ of the Bcl2 locus. Increased levels of Bcl2 mRNA and protein were observed in the B cells of Igh-3’E-bcl2 mice. B cells from Igh-3’E-bcl2 mice demonstrated an extended survival in vitro compared with B cells from wild-type mice. The Bcl2 promoter shift from P1 (the 5’ promoter) to P2 (the 3’ promoter) was observed in B cells from Igh-3’E-bcl2 mice, similar to human t(14;18) lymphomas. The IgH-3’E-bcl2 mice developed monoclonal B-cell follicular lymphomas, which were slowly progressive. These studies demonstrate that the Igh 3’ enhancers play an important role in the deregulation of Bcl2 and B-cell lymphomagenesis in vivo. PMID:21606958

  10. Extensive Gene-Specific Translational Reprogramming in a Model of B Cell Differentiation and Abl-Dependent Transformation

    PubMed Central

    Bates, Jamie G.; Salzman, Julia; May, Damon; Garcia, Patty B.; Hogan, Gregory J.; McIntosh, Martin; Schlissel, Mark S.; Brown, Pat O.

    2012-01-01

    To what extent might the regulation of translation contribute to differentiation programs, or to the molecular pathogenesis of cancer? Pre-B cells transformed with the viral oncogene v-Abl are suspended in an immortalized, cycling state that mimics leukemias with a BCR-ABL1 translocation, such as Chronic Myelogenous Leukemia (CML) and Acute Lymphoblastic Leukemia (ALL). Inhibition of the oncogenic Abl kinase with imatinib reverses transformation, allowing progression to the next stage of B cell development. We employed a genome-wide polysome profiling assay called Gradient Encoding to investigate the extent and potential contribution of translational regulation to transformation and differentiation in v-Abl-transformed pre-B cells. Over half of the significantly translationally regulated genes did not change significantly at the level of mRNA abundance, revealing biology that might have been missed by measuring changes in transcript abundance alone. We found extensive, gene-specific changes in translation affecting genes with known roles in B cell signaling and differentiation, cancerous transformation, and cytoskeletal reorganization potentially affecting adhesion. These results highlight a major role for gene-specific translational regulation in remodeling the gene expression program in differentiation and malignant transformation. PMID:22693568

  11. The 'zinc knuckle' motif of Early B cell Factor is required for transcriptional activation of B cell-specific genes

    PubMed Central

    Fields, Scott; Ternyak, Kristina; Gao, Hua; Ostraat, Rachel; Akerlund, Janie; Hagman, James

    2008-01-01

    Early B cell factor (EBF) is a critical regulator of B lymphocyte-specific gene transcription. EBF functions, in part, by binding to regulatory sites of genes required for the pre-B- and mature B cell receptors. These DNA targets include the promoters of the mb-1 and Vpreb1 genes that encode Ig-? and one of the components of surrogate light chain, respectively. The biochemical basis of DNA binding and gene activation by EBF is poorly understood. The DNA-binding domain (DBD) of EBF includes a putative zinc-binding motif (HX3CX2CX5C), which we have designated the 'Zn-knuckle'. The Zn-knuckle is required for binding of the mb-1 promoter site in EMSA, but it has not been demonstrated to be important for functional activities of EBF in B cells. Therefore, we expressed EBF with mutations in the Zn-knuckle motif or flanking sequences in plasmacytoma cells in which activation of endogenous mb-1 and Vpreb1 genes is dependent on EBF. EBF with mutations that prevent zinc coordination by the Zn-knuckle did not activate transcription of either target gene. Other mutations affected the sequence preference of DNA binding and differentially inhibited activation of these genes. Our results demonstrate the importance of the Zn-knuckle motif in EBF. These experiments also confirm that EBF can re-activate multiple genes of the early B cell program in plasmacytoma cells, which provide a useful cell-based assay for dissecting mechanisms involving EBF. PMID:18606452

  12. The Prognosis of MYC Translocation Positive Diffuse Large B-Cell Lymphoma Depends on The Second Hit

    E-print Network

    Clipson, Alexandra; Barrans, Sharon; Zeng, Naiyan; Crouch, Simon; Grigoropoulos, Nicholas F.; Liu, Hongxiang; Kocialkowski, Sylvia; Wang, Ming; Huang, Yuanxue; Worrillow, Lisa; Goodlad, John; Buxton, Jenny; Neat, Michael; Fields, Paul; Wilkins, Bridget; Grant, John W.; Wright, Penny; EI-Daly, Hesham; Follows, George A.; Roman, Eve; Watkins, A. James; Johnson, Peter W. M.; Jack, Andrew; Du, Ming-Qing

    2015-01-08

    the immunoglobulin heavy chain gene locus predict better sur- vival in gastric diffuse large B-cell lymphoma. Clin Cancer Res 2008; 14: 3002–3010. 31. Horn H, Ziepert M, Becher C, et al. MYC status in concert with BCL2 and BCL6 expression predicts outcome in diffuse... , Epidemiology and Cancer Statistics Group, University of York, York, UK 4 Department of Haematology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK 5 Department of Histopathology, Addenbrooke’s Hospital, Cambridge...

  13. Systematic Comparison of Gene Expression between Murine Memory and Naive B Cells Demonstrates That Memory B Cells Have Unique Signaling Capabilities1

    PubMed Central

    Tomayko, Mary M.; Anderson, Shannon M.; Brayton, Catherine E.; Sadanand, Saheli; Steinel, Natalie C.; Behrens, Timothy W.; Shlomchik, Mark J.

    2015-01-01

    Memory B cells play essential roles in the maintenance of long-term immunity and may be important in the pathogenesis of autoimmune disease, but how these cells are distinguished from their naive precursors is poorly understood. To address this, it would be important to understand how gene expression differs between memory and naive B cells to elucidate memory-specific functions. Using model systems that help overcome the lack of murine memory-specific markers and the low frequency of Agspecific memory and naive cells, we undertook a global comparison of gene expression between memory B cells and their naive precursors. We identified genes with differential expression and confirmed the differential expression of many of these by quantitative RT-PCR and of some of these at the protein level. Our initial analysis revealed differential expression patterns of genes that regulate signaling. Memory B cells have increased expression of genes important in regulating adenosine signaling and in modulating cAMP responses. Furthermore, memory B cells up-regulate receptors that are essential for embryonic stem cell self-renewal. We further demonstrate that one of these, leukemia inhibitory factor receptor, can initiate functional signaling in memory B cells whereas it does not in naive B cells. Thus, memory and naive B cells are intrinsically wired to signal differently from one another and express a functional signaling pathway that is known to maintain stem cells in other lineages. PMID:18566367

  14. B-cell lymphomas with concurrent MYC and BCL2 abnormalities other than translocations behave similarly to MYC/BCL2 double-hit lymphomas.

    PubMed

    Li, Shaoying; Seegmiller, Adam C; Lin, Pei; Wang, Xuan J; Miranda, Roberto N; Bhagavathi, Sharathkumar; Medeiros, L Jeffrey

    2015-02-01

    Large B-cell lymphomas with IGH@BCL2 and MYC rearrangement, known as double-hit lymphoma (DHL), are clinically aggressive neoplasms with a poor prognosis. Some large B-cell lymphomas have concurrent abnormalities of MYC and BCL2 other than coexistent translocations. Little is known about patients with these lymphomas designated here as atypical DHL. We studied 40 patients of atypical DHL including 21 men and 19 women, with a median age of 60 years. Nine (23%) patients had a history of B-cell non-Hodgkin lymphoma. There were 30 diffuse large B-cell lymphoma (DLBCL), 7 B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma, and 3 DLBCL with coexistent follicular lymphoma. CD10, BCL2, and MYC were expressed in 28/39 (72%), 33/35 (94%), and 14/20 (70%) cases, respectively. Patients were treated with standard (n=14) or more aggressive chemotherapy regimens (n=17). We compared the atypical DHL group with 76 patients with DHLand 35 patients with DLBCL lacking MYC and BCL2 abnormalities. The clinicopathologic features and therapies were similar between patients with atypical and typical DHL. The overall survival of patients with atypical double-hit lymphoma was similar to that of patients with double-hit lymphoma (P=0.47) and significantly worse than that of patients with DLBCL with normal MYC and BCL2 (P=0.02). There were some minor differences. Cases of atypical double-hit lymphoma more often have DLBCL morphology (P<0.01), less frequently expressed CD10 (P<0.01), and patients less often had an elevated serum lactate dehydrogenase level (P=0.01). In aggregate, these results support expanding the category of MYC/BCL2 DHL to include large B-cell lymphomas with coexistent MYC and BCL2 abnormalities other than concurrent translocations. PMID:25103070

  15. Targeted gene analysis: increased B-cell lymphoma 6 in preeclamptic placentas.

    PubMed

    Louwen, Frank; Muschol-Steinmetz, Cornelia; Friemel, Alexandra; Kämpf, Anne Kristina; Töttel, Eva; Reinhard, Joscha; Yuan, Juping

    2014-06-01

    Preeclampsia is a leading cause for maternal and perinatal mortality and morbidity. Microarray-based transcriptional profiling has been widely used for identifying genes responsible for preeclampsia. These studies deliver multiple pictures of gene signatures, implying the complicated pathophysiology. In the present work, we designed our own gene array containing genes involved in various signaling transduction pathways and analyzed placental samples from patients with preeclampsia and controls. We verify that genes associated with angiogenesis and migration pathways are mostly altered in preeclamptic placentas. Interestingly, several genes including B-cell lymphoma 6 have been identified to be linked to preeclampsia. Increased expression of B-cell lymphoma 6 is correlated with enhanced FLT1 and LEPTIN, the hallmarks of preeclampsia. Moreover, the protein level of B-cell lymphoma 6 is elevated in preeclamptic placentas and is predominantly localized in the nucleus of villous cytotrophoblasts lying directly underneath the syncytial layer, suggestive of an involvement in the function of villous trophoblasts. Altered B-cell lymphoma 6, a key oncogene in B-cell lymphomagenesis, may be involved in the pathogenesis of preeclampsia, and further investigations are required to decipher the molecular mechanisms. PMID:24767250

  16. Prognostic Significance of B-cell Differentiation Genes Encoding Proteins in Diffuse Large B-cell Lymphoma and Follicular Lymphoma Grade 3

    PubMed Central

    Borove?ki, Ana; Kora?, Petra; Nola, Marin; Ivankovi?, Davor; Jakši?, Branimir; Dominis, Mara

    2008-01-01

    Aim To define prognostic significance of B-cell differentiation genes encoding proteins and BCL2 and BCL6 gene abnormalities in diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern. Methods In 53 patients with diffuse large B-cell lymphoma and 20 patients with follicular lymphoma grade 3 with >75% follicular growth pattern the following was performed: 1) determination of protein expression of BCL6, CD10, MUM1/IRF4, CD138, and BCL2 by immunohistochemistry; 2) subclassification into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) groups according to the results of protein expression; 3) detection of t(14;18)(q32;q21)/IgH-BCL2 and BCL6 abnormalities by fluorescent in situ hybridization in diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern as well as in GCB and ABC groups; and 4) assessment of the influence of the analyzed characteristics and clinical prognostic factors on overall survival. Results Isolated BCL6 expression was more frequently found in follicular lymphoma grade 3 with >75% follicular growth pattern than in diffuse large B-cell lymphoma (P?=?0.030). There were no differences in BCL2 and BCL6 gene abnormalities between diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern. Diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern patients were equally distributed in GCB and ABC groups. t(14;18)(q32;q21) was more frequently recorded in GCB group, and t(14;18)(q32;q21) with BCL2 additional signals or only BCL2 and IgH additional signals in ABC group (P?=?0.004). The GCB and ABC groups showed no difference in BCL6 gene abnormalities. There was no overall survival difference between the patients with diffuse large B-cell lymphoma or follicular lymphoma grade 3 with >75% follicular growth pattern, however, GCB group had longer overall survival than ABC group (P?=?0.047). Multivariate analysis showed that BCL6, CD10, and BCL2 expression, BCL2 and BCL6 abnormalities, and International Prognostic Index were not significantly related to overall survival. Conclusion Patients with diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern have very similar characteristics and their prognosis is more influenced by protein expression of B-cell differentiation stage genes than by tumor cells growth pattern, BCL2 and BCL6 abnormalities, and International Prognostic Index. PMID:18925696

  17. Correlation of Gene Expression and Genome Mutation in Single B-Cells

    E-print Network

    Quake, Stephen R.

    of the antibody heavy chain gene, initially expressed as IgM and IgD classes, may change to IgG, IgA, or IgE applied this method by quantifying the relationships between gene expression and antibody mutation specific to antigens. For B- cells, these receptors, called immunoglobulins, or antibodies, form

  18. Acute leukemias of different lineages have similar MLL gene fusions encoding related chimeric proteins resulting from chromosomal translocation

    SciTech Connect

    Corral, J.; Forster, A.; Thompson, S.; Rabbitts, T.H. ); Lampert, F. ); Kaneko, Y. ); Slater, R.; Kroes, W.G. ); Van Der Schoot, C.E. ); Ludwig, W.D. ); Karpas, A. ); Pocock, C.; Cotter, F. )

    1993-09-15

    The MLL gene, on human chromosome 11q23, undergoes chromosomal translocation in acute leukemias, resulting in gene fusion with AF4 (chromosome 4) and ENL (chromosome 19). The authors report here translocation of MLL with nine different chromosomes and two paracentric chromosome 11 deletions in early B cell, B- or T-cell lineage, or nonlymphocytic acute leukemias. The mRNA translocation junction from 22t(4;11) patients, including six adult leukemias, and nine t(11;19) tumors reveals a remarkable conservation of breakpoints within MLL, AF4, or ENL genes, irrespective of tumor phenotype. Typically, the breakpoints are upstream of the zinc-finger region of MLL, and deletion of this region can accompany translocation, supporting the der(11) chromosome as the important component in leukemogenesis. Partial sequence of a fusion between MLL and the AFX1 gene from chromosome X shows the latter to be rich in Ser/Pro codons, like the ENL mRNA. These data suggest that the heterogeneous 11q23 abnormalities might cause attachment of Ser/Pro-rich segments to the NH[sub 2] terminus of MLL, lacking the zinc-finger region, and that translocation occurs in early hematopoietic cells, before commitment to distinct lineages. 36 refs., 2 figs.

  19. RNA analysis of B cell lines arrested at defined stages of differentiation allows for an approximation of gene

    E-print Network

    Peterson, Carsten

    amounts of antibodies [10­12]. The ex- tensively studied biology of B cell development, in combina- tion of the molecular processes involved in B cell development and to create a map over stage-restricted gene expressionRNA analysis of B cell lines arrested at defined stages of differentiation allows

  20. Aberrantly Expressed OTX Homeobox Genes Deregulate B-Cell Differentiation in Hodgkin Lymphoma

    PubMed Central

    Nagel, Stefan; Ehrentraut, Stefan; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G.; MacLeod, Roderick A. F.

    2015-01-01

    In Hodgkin lymphoma (HL) we recently reported that deregulated homeobox gene MSX1 mediates repression of the B-cell specific transcription factor ZHX2. In this study we investigated regulation of MSX1 in this B-cell malignancy. Accordingly, we analyzed expression and function of OTX homeobox genes which activate MSX1 transcription during embryonal development in the neural plate border region. Our data demonstrate that OTX1 and OTX2 are aberrantly expressed in both HL patients and cell lines. Moreover, both OTX loci are targeted by genomic gains in overexpressing cell lines. Comparative expression profiling and subsequent pathway modulations in HL cell lines indicated that aberrantly enhanced FGF2-signalling activates the expression of OTX2. Downstream analyses of OTX2 demonstrated transcriptional activation of genes encoding transcription factors MSX1, FOXC1 and ZHX1. Interestingly, examination of the physiological expression profile of ZHX1 in normal hematopoietic cells revealed elevated levels in T-cells and reduced expression in B-cells, indicating a discriminatory role in lymphopoiesis. Furthermore, two OTX-negative HL cell lines overexpressed ZHX1 in correlation with genomic amplification of its locus at chromosomal band 8q24, supporting the oncogenic potential of this gene in HL. Taken together, our data demonstrate that deregulated homeobox genes MSX1 and OTX2 respectively impact transcriptional inhibition of (B-cell specific) ZHX2 and activation of (T-cell specific) ZHX1. Thus, we show how reactivation of a specific embryonal gene regulatory network promotes disturbed B-cell differentiation in HL. PMID:26406991

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

    PubMed Central

    Hopp, Lydia; Löffler-Wirth, Henry; Binder, Hans

    2015-01-01

    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. PMID:26371046

  2. Global gene expression changes of in vitro stimulated human transformed germinal centre B cells as surrogate for oncogenic pathway activation in individual aggressive B cell lymphomas

    PubMed Central

    2012-01-01

    Background Aggressive Non-Hodgkin lymphomas (NHL) are a group of lymphomas derived from germinal centre B cells which display a heterogeneous pattern of oncogenic pathway activation. We postulate that specific immune response associated signalling, affecting gene transcription networks, may be associated with the activation of different oncogenic pathways in aggressive Non-Hodgkin lymphomas (NHL). Methodology The B cell receptor (BCR), CD40, B-cell activating factor (BAFF)-receptors and Interleukin (IL) 21 receptor and Toll like receptor 4 (TLR4) were stimulated in human transformed germinal centre B cells by treatment with anti IgM F(ab)2-fragments, CD40L, BAFF, IL21 and LPS respectively. The changes in gene expression following the activation of Jak/STAT, NF-?B, MAPK, Ca2+ and PI3K signalling triggered by these stimuli was assessed using microarray analysis. The expression of top 100 genes which had a change in gene expression following stimulation was investigated in gene expression profiles of patients with Aggressive non-Hodgkin Lymphoma (NHL). Results ?IgM stimulation led to the largest number of changes in gene expression, affecting overall 6596 genes. While CD40L stimulation changed the expression of 1194 genes and IL21 stimulation affected 902 genes, only 283 and 129 genes were modulated by lipopolysaccharide or BAFF receptor stimulation, respectively. Interestingly, genes associated with a Burkitt-like phenotype, such as MYC, BCL6 or LEF1, were affected by ?IgM. Unique and shared gene expression was delineated. NHL-patients were sorted according to their similarity in the expression of TOP100 affected genes to stimulated transformed germinal centre B cells The ?IgM gene module discriminated individual DLBCL in a similar manner to CD40L or IL21 gene modules. DLBCLs with low module activation often carry chromosomal MYC aberrations. DLBCLs with high module activation show strong expression of genes involved in cell-cell communication, immune responses or negative feedback loops. Using chemical inhibitors for selected kinases we show that mitogen activated protein kinase- and phosphoinositide 3 kinase-signalling are dominantly involved in regulating genes included in the ?IgM gene module. Conclusion We provide an in vitro model system to investigate pathway activation in lymphomas. We defined the extent to which different immune response associated pathways are responsible for differences in gene expression which distinguish individual DLBCL cases. Our results support the view that tonic or constitutively active MAPK/ERK pathways are an important part of oncogenic signalling in NHL. The experimental model can now be applied to study the therapeutic potential of deregulated oncogenic pathways and to develop individual treatment strategies for lymphoma patients. PMID:23253402

  3. TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma

    Cancer.gov

    Published on Office of Cancer Genomics (http://ocg.cancer.gov) Home > TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma [1] May 24, 2012 Using RNA sequencing

  4. TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma

    Cancer.gov

    Published on Office of Cancer Genomics (https://ocg.cancer.gov) Home > TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma [1] May 24, 2012 Using RNA sequencing

  5. Harnessing Gene Conversion in Chicken B Cells to Create a Human Antibody Sequence Repertoire

    PubMed Central

    Schusser, Benjamin; Yi, Henry; Collarini, Ellen J.; Izquierdo, Shelley Mettler; Harriman, William D.; Etches, Robert J.; Leighton, Philip A.

    2013-01-01

    Transgenic chickens expressing human sequence antibodies would be a powerful tool to access human targets and epitopes that have been intractable in mammalian hosts because of tolerance to conserved proteins. To foster the development of the chicken platform, it is beneficial to validate transgene constructs using a rapid, cell culture-based method prior to generating fully transgenic birds. We describe a method for the expression of human immunoglobulin variable regions in the chicken DT40 B cell line and the further diversification of these genes by gene conversion. Chicken VL and VH loci were knocked out in DT40 cells and replaced with human VK and VH genes. To achieve gene conversion of human genes in chicken B cells, synthetic human pseudogene arrays were inserted upstream of the functional human VK and VH regions. Proper expression of chimeric IgM comprised of human variable regions and chicken constant regions is shown. Most importantly, sequencing of DT40 genetic variants confirmed that the human pseudogene arrays contributed to the generation of diversity through gene conversion at both the Igl and Igh loci. These data show that engineered pseudogene arrays produce a diverse pool of human antibody sequences in chicken B cells, and suggest that these constructs will express a functional repertoire of chimeric antibodies in transgenic chickens. PMID:24278246

  6. Fucoidan prevents C{epsilon} germline transcription and NF{kappa}B p52 translocation for IgE production in B cells

    SciTech Connect

    Oomizu, Souichi; Yanase, Yuhki; Suzuki, Hidenori; Kameyoshi, Yoshikazu; Hide, Michihiro . E-mail: mhide@hiroshima-u.ac.jp

    2006-11-24

    Fucoidan, a dietary fiber contained in seaweed, reduces the increase of antigen-specific IgE in mice exposed to ovalbumin. In this study, we investigated the effect of fucoidan on IgE production and intracellular events in B cells in vitro. Fucoidan inhibited the production of IgE and C{epsilon} germline transcription in murine B cells induced by IL-4 (100 ng/ml) and anti-CD40 antibodies (10 {mu}g/ml), whereas it stimulated cell proliferation. A significant effect of fucoidan on IgE production was observed when B cells were stimulated with a higher dose (5 {mu}g/ml) of anti-CD40 antibodies, but not when stimulated with lower doses (1.25, 2.5 {mu}g/ml), regardless of the IL-4 concentrations. Moreover, nuclear translocation of NF{kappa}B p52, but neither that of NF{kappa}B p65, nor the phosphorylation of JAK1 and STAT6 was reduced by fucoidan. These results suggest that fucoidan inhibited IgE production by preventing the NF{kappa}B p52-mediated pathways activated by CD40.

  7. Role of STAT5 in controlling cell survival and immunoglobin gene recombination during pro-B cell development

    PubMed Central

    Malin, Stephen; McManus, Shane; Cobaleda, César; Novatchkova, Maria; Delogu, Alessio; Bouillet, Philippe; Strasser, Andreas; Busslinger, Meinrad

    2010-01-01

    STAT5 and IL-7 signaling are thought to control B-lymphopoiesis by regulating key transcription factor genes and activating VH gene segments at the Igh locus. Using conditional mutagenesis, we demonstrate that transgenic Bcl2 expression rescued the development of Stat5-deleted pro-B cells by compensating for the loss of Mcl-1. Ebf1 and Pax5 expression as well as VH gene recombination were normal in Bcl2-rescued pro-B cells lacking STAT5 or IL-7R?. In agreement with this finding, STAT5-expressing pro-B cells contained little or no active chromatin at most VH genes. In contrast, Igk rearrangements were increased in STAT5-or IL-7R?-deficient pro-B cells. Hence, STAT5 and IL-7 signaling control cell survival and the developmental ordering of immunoglobulin gene rearrangements by suppressing premature Igk recombination in pro-B cells. PMID:19946273

  8. B-cell reconstitution after lentiviral vector–mediated gene therapy in patients with Wiskott-Aldrich syndrome

    PubMed Central

    Castiello, Maria Carmina; Scaramuzza, Samantha; Pala, Francesca; Ferrua, Francesca; Uva, Paolo; Brigida, Immacolata; Sereni, Lucia; van der Burg, Mirjam; Ottaviano, Giorgio; Albert, Michael H.; Grazia Roncarolo, Maria; Naldini, Luigi; Aiuti, Alessandro; Villa, Anna; Bosticardo, Marita

    2015-01-01

    Background Wiskott-Aldrich syndrome (WAS) is a severe X-linked immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, and susceptibility to autoimmunity and lymphomas. Hematopoietic stem cell transplantation is the treatment of choice; however, administration of WAS gene–corrected autologous hematopoietic stem cells has been demonstrated as a feasible alternative therapeutic approach. Objective Because B-cell homeostasis is perturbed in patients with WAS and restoration of immune competence is one of the main therapeutic goals, we have evaluated reconstitution of the B-cell compartment in 4 patients who received autologous hematopoietic stem cells transduced with lentiviral vector after a reduced-intensity conditioning regimen combined with anti-CD20 administration. Methods We evaluated B-cell counts, B-cell subset distribution, B cell–activating factor and immunoglobulin levels, and autoantibody production before and after gene therapy (GT). WAS gene transfer in B cells was assessed by measuring vector copy numbers and expression of Wiskott-Aldrich syndrome protein. Results After lentiviral vector-mediated GT, the number of transduced B cells progressively increased in the peripheral blood of all patients. Lentiviral vector-transduced progenitor cells were able to repopulate the B-cell compartment with a normal distribution of B-cell subsets both in bone marrow and the periphery, showing a WAS protein expression profile similar to that of healthy donors. In addition, after GT, we observed a normalized frequency of autoimmune-associated CD19+CD21?CD35? and CD21low B cells and a reduction in B cell–activating factor levels. Immunoglobulin serum levels and autoantibody production improved in all treated patients. Conclusions We provide evidence that lentiviral vector-mediated GT induces transgene expression in the B-cell compartment, resulting in ameliorated B-cell development and functionality and contributing to immunologic improvement in patients with WAS. PMID:25792466

  9. Compositions and methods for detecting gene rearrangements and translocations

    DOEpatents

    Rowley, Janet D. (Chicago, IL); Diaz, Manuel O. (Chicago, IL)

    2000-01-01

    Disclosed is a series of nucleic acid probes for use in diagnosing and monitoring certain types of leukemia using, e.g., Southern and Northern blot analyses and fluorescence in situ hybridization (FISH). These probes detect rearrangements, such as translocations involving chromosome band 11q23 with other chromosomes bands, including 4q21, 6q27, 9p22, 19p13.3, in both dividing leukemic cells and interphase nuclei. The breakpoints in all such translocations are clustered within an 8.3 kb BamHI genomic region of the MLL gene. A novel 0.7 kb BamH1 cDNA fragment derived from this gene detects rearrangements on Southern blot analysis with a single BamHI restriction digest in all patients with the common 11q23 translocations and in patients with other 11q23 anomalies. Northern blot analyses are presented demonstrating that the MLL gene has multiple transcripts and that transcript size differentiates leukemic cells from normal cells. Also disclosed are MLL fusion proteins, MLL protein domains and anti-MLL antibodies.

  10. Statin-induced changes in gene expression in EBV-transformed and native B-cells.

    PubMed

    Bolotin, Eugene; Armendariz, Angela; Kim, Kyungpil; Heo, Seok-Jin; Boffelli, Dario; Tantisira, Kelan; Rotter, Jerome I; Krauss, Ronald M; Medina, Marisa W

    2014-03-01

    Human lymphoblastoid cell lines (LCLs), generated through Epstein-Barr Virus (EBV) transformation of B-lymphocytes (B-cells), are a commonly used model system for identifying genetic influences on human diseases and on drug responses. We have previously used LCLs to examine the cellular effects of genetic variants that modulate the efficacy of statins, the most prescribed class of cholesterol-lowering drugs used for the prevention and treatment of cardiovascular disease. However, statin-induced gene expression differences observed in LCLs may be influenced by their transformation, and thus differ from those observed in native B-cells. To assess this possibility, we prepared LCLs and purified B-cells from the same donors, and compared mRNA profiles after 24 h incubation with simvastatin (2 µm) or sham buffer. Genes involved in cholesterol metabolism were similarly regulated between the two cell types under both the statin and sham-treated conditions, and the statin-induced changes were significantly correlated. Genes whose expression differed between the native and transformed cells were primarily implicated in cell cycle, apoptosis and alternative splicing. We found that ChIP-seq signals for MYC and EBNA2 (an EBV transcriptional co-activator) were significantly enriched in the promoters of genes up-regulated in the LCLs compared with the B-cells, and could be involved in the regulation of cell cycle and alternative splicing. Taken together, the results support the use of LCLs for the study of statin effects on cholesterol metabolism, but suggest that drug effects on cell cycle, apoptosis and alternative splicing may be affected by EBV transformation. This dataset is now uploaded to GEO at the accession number GSE51444. PMID:24179175

  11. Statin-induced changes in gene expression in EBV-transformed and native B-cells

    PubMed Central

    Bolotin, Eugene; Armendariz, Angela; Kim, Kyungpil; Heo, Seok-Jin; Boffelli, Dario; Tantisira, Kelan; Rotter, Jerome I.; Krauss, Ronald M.; Medina, Marisa W.

    2014-01-01

    Human lymphoblastoid cell lines (LCLs), generated through Epstein–Barr Virus (EBV) transformation of B-lymphocytes (B-cells), are a commonly used model system for identifying genetic influences on human diseases and on drug responses. We have previously used LCLs to examine the cellular effects of genetic variants that modulate the efficacy of statins, the most prescribed class of cholesterol-lowering drugs used for the prevention and treatment of cardiovascular disease. However, statin-induced gene expression differences observed in LCLs may be influenced by their transformation, and thus differ from those observed in native B-cells. To assess this possibility, we prepared LCLs and purified B-cells from the same donors, and compared mRNA profiles after 24 h incubation with simvastatin (2 µm) or sham buffer. Genes involved in cholesterol metabolism were similarly regulated between the two cell types under both the statin and sham-treated conditions, and the statin-induced changes were significantly correlated. Genes whose expression differed between the native and transformed cells were primarily implicated in cell cycle, apoptosis and alternative splicing. We found that ChIP-seq signals for MYC and EBNA2 (an EBV transcriptional co-activator) were significantly enriched in the promoters of genes up-regulated in the LCLs compared with the B-cells, and could be involved in the regulation of cell cycle and alternative splicing. Taken together, the results support the use of LCLs for the study of statin effects on cholesterol metabolism, but suggest that drug effects on cell cycle, apoptosis and alternative splicing may be affected by EBV transformation. This dataset is now uploaded to GEO at the accession number GSE51444 PMID:24179175

  12. B-cell lymphoma gene regulatory networks: biological consistency among inference methods

    PubMed Central

    de Matos Simoes, Ricardo; Dehmer, Matthias; Emmert-Streib, Frank

    2013-01-01

    Despite the development of numerous gene regulatory network (GRN) inference methods in the last years, their application, usage and the biological significance of the resulting GRN remains unclear for our general understanding of large-scale gene expression data in routine practice. In our study, we conduct a structural and a functional analysis of B-cell lymphoma GRNs that were inferred using 3 mutual information-based GRN inference methods: C3Net, BC3Net and Aracne. From a comparative analysis on the global level, we find that the inferred B-cell lymphoma GRNs show major differences. However, on the edge-level and the functional-level—that are more important for our biological understanding—the B-cell lymphoma GRNs were highly similar among each other. Also, the ranks of the degree centrality values and major hub genes in the inferred networks are highly conserved as well. Interestingly, the major hub genes of all GRNs are associated with the G-protein-coupled receptor pathway, cell-cell signaling and cell cycle. This implies that hub genes of the GRNs can be highly consistently inferred with C3Net, BC3Net, and Aracne, representing prominent targets for signaling pathways. Finally, we describe the functional and structural relationship between C3Net, BC3Net and Aracne gene regulatory networks. Our study shows that these GRNs that are inferred from large-scale gene expression data are promising for the identification of novel candidate interactions and pathways that play a key role in the underlying mechanisms driving cancer hallmarks. Overall, our comparative analysis reveals that these GRNs inferred with considerably different inference methods contain large amounts of consistent, method independent, biological information. PMID:24379827

  13. Triple-hit B-cell Lymphoma With MYC, BCL2, and BCL6 Translocations/Rearrangements: Clinicopathologic Features of 11 Cases.

    PubMed

    Wang, Wei; Hu, Shimin; Lu, Xinyan; Young, Ken H; Medeiros, L Jeffrey

    2015-08-01

    Lymphomas with translocations/rearrangements of MYC, BCL2, and BCL6, so-called triple-hit B-cell lymphoma, are rare, and few studies on these tumors are available in the literature. We report 11 cases of triple-hit B-cell lymphoma and characterize their clinicopathologic findings. All patients were men, with a median age of 64 years (range, 45 to 80 y), and 4 patients had antecedent or concurrent follicular lymphoma. Using the 2008 World Health Organization classification, these cases were classified as: 5 B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma; 4 DLBCL; 1 DLBCL with concurrent follicular lymphoma; and 1 low-grade follicular lymphoma. All cases were positive for CD10, BCL2, and FOXP1. Ten of 11 cases were positive for CD20. MYC expression was high in 10/11 (91%), BCL6 was positive in 8/11 (73%), and MUM1/IRF4 was positive in 6/11 (55%) cases. T-cell antigens, TdT, and Epstein-Barr virus-encoded RNA were negative in all cases. Ten of 11 cases showed a high proliferation index-70% to 100%, and the follicular lymphoma had a 30% proliferation rate. Using most algorithms, all cases belonged to germinal center B-cell-like group. All patients received standard or more aggressive immunochemotherapy regimens. Three patients had no response to chemotherapy; 4 patients showed a partial response; 2 patients had complete remission after chemotherapy; and 2 patients had just begun chemotherapy. Three patients underwent a stem cell transplant. The median follow-up time was 5.3 months. Five patients died, and 6 patients were alive at last follow-up. Two patients who underwent stem cell transplant after complete response to chemotherapy were in remission with 16 to 19 months of clinical follow-up. In summary, triple-hit lymphomas are clinically aggressive tumors associated with a poor prognosis. Patients often respond poorly to chemotherapy, but a subset may completely respond to chemotherapy followed by stem cell transplant. PMID:25828391

  14. Immunoglobulin gene rearrangement and cell surface antigen expression in acute lymphocytic leukemias of T cell and B cell precursor origins.

    PubMed Central

    Korsmeyer, S J; Arnold, A; Bakhshi, A; Ravetch, J V; Siebenlist, U; Hieter, P A; Sharrow, S O; LeBien, T W; Kersey, J H; Poplack, D G; Leder, P; Waldmann, T A

    1983-01-01

    We have explored the relationship among immunoglobulin gene rearrangement, cytoplasmic immunoglobulin production, and cell surface antigen expression within 37 cases of acute lymphocytic leukemia. All 12 cases of the T cell type had germ-line kappa and lambda genes and 11 of 12 had germ-line heavy chain genes. In contrast, all 25 cases of the "non-T, non-B" classification, which lacked both definitive T cell markers and surface immunoglobulin, had rearranged immunoglobulin genes, indicating that they represent precursor cells already committed to the B cell lineage at the gene level. 14 had rearranged heavy chain genes, yet retained germ-line light chain genes, whereas 11 cases had both heavy and light chain gene reorganizations. All patterns of immunoglobulin gene rearrangement predicted by a model that proceeds from heavy chain gene recombination to light chain genes were observed. Despite the uniform presence of rearranged immunoglobulin genes, only five cases produced cytoplasmic mu-chain, one exceptional case produced gamma-chain, and another produced only lambda-chain. The cases of B cell precursor type that do not produce immunoglobulin may represent cells that frequently possess ineffectively rearranged immunoglobulin genes. Included in this group may be a set of cells trapped within the B cell precursor series because their ineffective rearrangements have eliminated certain gene subsegments necessary for the assemblage of an effective heavy chain gene. All seven cases of the non-T, non-B subgroup that bore HLA-DR but lacked CALLA (the common acute lymphocytic leukemia-associated antigen) represented the earliest recognizable stage of B cell precursors with rearranged heavy chain genes but germ-line light chain genes. Correlations here suggest that cells entering B cell development express HLA-DR and rearrange heavy chain genes before the expression of a B cell-associated antigen recognized by the antibody BA-1, the antigen CALLA, and any subsequent light chain gene rearrangements. Images PMID:6401769

  15. NODAL DIFFUSE LARGE B-CELL LYMPHOMAS IN CHILDREN AND ADOLESCENTS: IMMUNOHISTOCHEMICAL EXPRESSION PATTERNS AND C-MYC TRANSLOCATION IN RELATION TO CLINICAL OUTCOME

    PubMed Central

    Gualco, Gabriela; Weiss, Lawrence M.; Harrington, William J.; Bacchi, Carlos E.

    2009-01-01

    Diffuse large B-cell lymphoma (DLBCL) is a very infrequent neoplasm in the pediatric age group; therefore there are very few studies on the immunophenotype or genetics of these cases. We studied a series of 16 patients with nodal DLBCL occurring in patients between 10 and 18 years of age. The cases were classified according to the 2008 World Health Organization classification criteria, with application of immunohistochemistry for the detection of CD10, BCL-6 and MUM1 proteins to divide the lymphomas into germinal center and non-germinal center types. In addition, TCL1, BCL-2 expression, and the Ki-67 proliferation index were evaluated by immunohistochemistry, and c-MYC and BCL-2 translocations were evaluated by FISH. All these parameters were correlated with clinical features and outcome. Our study revealed that centroblastic morphology and the germinal center type of DLBCL are more prevalent in these young patients (63%), with 37% containing a c-MYC translocation. Only one case showed a BCL-2 translocation, reflecting a double-hit case with features intermediate between DLBCL and Burkitt lymphoma. We found a higher frequency of BCL-2 expression than previously reported, with no direct influence on the outcome of the disease in univariate or multivariate analysis. The expression of TCL1 has not been specifically studied in nodal pediatric DLBCL before; we found a 31% incidence of TCL1 expression. MUM1 expression was observed in 44% of the cases and these positive cases showed a significant negative impact on clinical outcome. TCL1 is directly and significantly associated with the presence of c-MYC and a high proliferative index. The germinal center and non-germinal center subtypes showed significant differences for both overall survival and disease-free interval. C-MYC translocation was found in 37% of patients, and had a favorable impact on clinical outcome. We conclude that nodal pediatric and adolescent DLBCL are mainly of the germinal center type, with a generally good outcome in spite of the frequent expression of BCL-2 and the presence of c-MYC translocation. TCL1 expression seems to be associated with a good clinical outcome, while MUM1 expression predicts a poor clinical outcome. PMID:19816150

  16. TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma

    Cancer.gov

    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).

  17. Inherited variation in immune response genes in follicular lymphoma and diffuse large B-cell lymphoma.

    PubMed

    Nielsen, Kaspar Rene; Steffensen, Rudi; Haunstrup, Thure Mors; Bødker, Julie Støve; Dybkær, Karen; Baech, John; Bøgsted, Martin; Johnsen, Hans Erik

    2015-12-01

    Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) both depend on immune-mediated survival and proliferation signals from the tumor microenvironment. Inherited genetic variation influences this complex interaction. A total of 89 studies investigating immune-response genes in DLBCL and FL were critically reviewed. Relatively consistent association exists for variation in the tumor necrosis factor alpha (TNFA) and interleukin-10 loci and DLBCL risk; for DLBCL outcome association with the TNFA locus exists. Variations at chromosome 6p31-32 were associated with FL risk. Importantly, individual risk alleles have been shown to interact with each other. We suggest that the pathogenetic impact of polymorphic genes should include gene-gene interaction analysis and should be validated in preclinical model systems of normal B lymphopoiesis and B-cell malignancies. In the future, large cohort studies of interactions and genome-wide association studies are needed to extend the present findings and explore new risk alleles to be studied in preclinical models. PMID:26044172

  18. Molecular analysis of single B cells from T-cell-rich B-cell lymphoma shows the derivation of the tumor cells from mutating germinal center B cells and exemplifies means by which immunoglobulin genes are modified in germinal center B cells.

    PubMed

    Bräuninger, A; Küppers, R; Spieker, T; Siebert, R; Strickler, J G; Schlegelberger, B; Rajewsky, K; Hansmann, M L

    1999-04-15

    T-cell-rich B-cell lymphoma (TCRBCL) belongs to the group of diffuse large cell lymphomas (DLL). It is characterized by a small number of tumor B cells among a major population of nonmalignant polyclonal T cells. To identify the developmental stage of the tumor progenitor cells, we micromanipulated the putative neoplastic large CD20(+) cells from TCRBCLs and amplified and sequenced immunoglobulin (Ig) V gene rearrangements from individual cells. In six cases, clonal Ig heavy, as well as light chain, gene rearrangements were amplified from the isolated B cells. All six cases harbored somatically mutated V gene rearrangements with an average mutation frequency of 15.5% for heavy (VH) and 5.9% for light (VL) chains and intraclonal diversity based on somatic mutation. These findings identify germinal center (GC) B cells as the precursors of the transformed B cells in TCRBCL. The study also exemplifies various means how Ig gene rearrangements can be modified by GC B cells or their malignant counterparts in TCRBCL: In one case, the tumor precursor may have switched from kappa to lambda light chain expression after acquiring a crippling mutation within the initially functional kappa light chain gene. In another case, the tumor cells harbor two in-frame VH gene rearrangements, one of which was rendered nonfunctional by somatic mutation. Either the tumor cell precursor entered the GC with two potentially functional in-frame rearrangements or the second VHDHJH rearrangement occurred in the GC after the initial in-frame rearrangement was inactivated by somatic mutation. Finally, in each of the six cases, at least one cell contained two (or more) copies of a clonal Ig gene rearrangement with sequence variations between these copies. The presence of sequence variants for V region genes within single B cells has so far not been observed in any other normal or transformed B lymphocyte. Fluorescence in situ hybridization (FISH) points to a generalized polyploidy of the tumor cells. PMID:10194448

  19. Harnessing RNAi-based nanomedicines for therapeutic gene silencing in B-cell malignancies.

    PubMed

    Weinstein, Shiri; Toker, Itai A; Emmanuel, Rafi; Ramishetti, Srinivas; Hazan-Halevy, Inbal; Rosenblum, Daniel; Goldsmith, Meir; Abraham, Avigdor; Benjamini, Ohad; Bairey, Osnat; Raanani, Pia; Nagler, Arnon; Lieberman, Judy; Peer, Dan

    2016-01-01

    Despite progress in systemic small interfering RNA (siRNA) delivery to the liver and to solid tumors, systemic siRNA delivery to leukocytes remains challenging. The ability to silence gene expression in leukocytes has great potential for identifying drug targets and for RNAi-based therapy for leukocyte diseases. However, both normal and malignant leukocytes are among the most difficult targets for siRNA delivery as they are resistant to conventional transfection reagents and are dispersed in the body. We used mantle cell lymphoma (MCL) as a prototypic blood cancer for validating a novel siRNA delivery strategy. MCL is an aggressive B-cell lymphoma that overexpresses cyclin D1 with relatively poor prognosis. Down-regulation of cyclin D1 using RNA interference (RNAi) is a potential therapeutic approach to this malignancy. Here, we designed lipid-based nanoparticles (LNPs) coated with anti-CD38 monoclonal antibodies that are specifically taken up by human MCL cells in the bone marrow of xenografted mice. When loaded with siRNAs against cyclin D1, CD38-targeted LNPs induced gene silencing in MCL cells and prolonged survival of tumor-bearing mice with no observed adverse effects. These results highlight the therapeutic potential of cyclin D1 therapy in MCL and present a novel RNAi delivery system that opens new therapeutic opportunities for treating MCL and other B-cell malignancies. PMID:26699502

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

    PubMed

    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. PMID:26366710

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

    PubMed Central

    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

    2015-01-01

    The lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL). 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 (GC) involution, impedes B cell differentiation and class switch recombination (CSR). Integrative genomic analyses indicate that KMT2D affects H3K4 methylation and expression of a specific set of genes including those in the CD40, JAK-STAT, Toll-like receptor, and B cell receptor 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. PMID:26366710

  2. A limited number of genes are involved in the differentiation of germinal center B cells.

    PubMed

    Nakayama, Yasuhiro; Stabach, Paul; Maher, Stephen E; Mahajan, Milind C; Masiar, Peter; Liao, Cheng; Zhang, Xueqing; Ye, Zhi-jia; Tuck, David; Bothwell, Alfred L M; Newburger, Peter E; Weissman, Sherman M

    2006-12-01

    Mature B cells, upon activation, progressively differentiate through centroblasts into centrocytes and finally to plasmacytes that express large amounts of selected immunoglobulins. A significant part of this maturation is thought to involve induction of the unfolded protein response (UPR). We have compared gene expression in normal germinal center centroblasts, centrocytes, lymphoblastoid cells undergoing induced UPR, and the CCL155 plasmacytoma cell line. In the centroblast to centrocyte transition there is a change in the expression of a relatively small number of genes. These include a limited subset of the genes upregulated by a fully activated UPR as well as a small number of other transcription factors, some disulphide isomerases, and other genes. This is consistent with a model in which this transition is mediated by changes in the levels of expression of transcription factor B-lymphocyte-induced maturation protein 1 (Blimp1) (PRDM1), BACH2, X-box binding protein 1 (XBP1), interferon regulatory factor 4 (IRF4), and possibly vitamin D receptor (VDR) expression, together with post-transcriptional changes and a limited induction of aspects of the UPR. PMID:16795035

  3. Gene Expression Profiling of the Response to Interferon Beta in Epstein-Barr-Transformed and Primary B Cells of Patients with Multiple Sclerosis

    PubMed Central

    Khsheibun, Rana; Paperna, Tamar; Volkowich, Anat; Lejbkowicz, Izabella; Avidan, Nili; Miller, Ariel

    2014-01-01

    The effects of interferon-beta (IFN-?), 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-?. To identify gene expression changes and pathways induced by IFN-? 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-? exposure, with over 50 previously unrecognized as IFN-? response genes. Pathways analysis demonstrated that IFN-? affected LCLs in a similar manner to other cell types by activating known IFN-? canonical pathways. Additionally, IFN-? 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-? response genes in primary B cells. In this study new IFN-? 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. PMID:25025430

  4. Molecular cloning and nucleotide sequence of a transforming gene detected by transfection of chicken B-cell lymphoma DNA

    NASA Astrophysics Data System (ADS)

    Goubin, Gerard; Goldman, Debra S.; Luce, Judith; Neiman, Paul E.; Cooper, Geoffrey M.

    1983-03-01

    A transforming gene detected by transfection of chicken B-cell lymphoma DNA has been isolated by molecular cloning. It is homologous to a conserved family of sequences present in normal chicken and human DNAs but is not related to transforming genes of acutely transforming retroviruses. The nucleotide sequence of the cloned transforming gene suggests that it encodes a protein that is partially homologous to the amino terminus of transferrin and related proteins although only about one tenth the size of transferrin.

  5. Novel prognostic genes of diffuse large B-cell lymphoma revealed by survival analysis of gene expression data

    PubMed Central

    Li, Chenglong; Zhu, Biao; Chen, Jiao; Huang, Xiaobing

    2015-01-01

    Objective This study aimed to identify prognostic genes for diffuse large B-cell lymphoma (DLBCL), using bioinformatic methods. Methods Five gene expression data sets were downloaded from the Gene Expression Omnibus database. Significance analysis of microarrays algorithm was used to identify differentially expressed genes (DEGs) from two data sets. Functional enrichment analysis was performed for the DEGs with the Database for Annotation, Visualization and Integration Discovery (DAVID). Survival analysis was performed with the Kaplan–Meier method using function survfit from package survival of R for the other three data sets. Cox univariate regression analysis was used to further screen out prognostic genes. Results Thirty-one common DEGs were identified in the two data sets, mainly enriched in the regulation of lymphocyte activation, immune response, and interleukin-mediated signaling pathway. Combined with 47 DLBCL-related genes acquired by literature retrieval, a total of 78 potential prognostic genes were obtained. Cases from the other three data sets were used in hierarchical clustering, and the 78 genes could cluster them into several subtypes with significant differences in survival curves. Cox univariate regression analysis revealed 45, 33, and eleven prognostic genes in the three data sets, respectively. Five common prognostic genes were revealed, including LCP2, TNFRSF9, FUT8, IRF4, and TLE1, among which LCP2, FUT8, and TLE1 were novel prognostic genes. Conclusion Five prognostic genes of DLBCL were identified in this study. They could not only be used for molecular subtyping of DLBCL but also be potential targets for treatment. PMID:26604798

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

    PubMed Central

    Nielsen, Kaspar René; Steffensen, Rudi; Bendtsen, Mette Dahl; Rodrigo-Domingo, Maria; Baech, John; Haunstrup, Thure Mors; Bergkvist, Kim Steve; Schmitz, Alexander; Boedker, Julie Stoeveve; Johansen, Preben; Dybkaeær, Karen; Boeøgsted, Martin; Johnsen, Hans Erik

    2015-01-01

    Background Malignant B-cell clones are affected by both acquired genetic alterations and by inherited genetic variations changing the inflammatory tumour microenvironment. Methods 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. Results 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. Conclusions 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. PMID:26448050

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

    PubMed

    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. PMID:26135560

  8. Extensive and selective mutation of a rearranged VH5 gene in human B cell chronic lymphocytic leukemia

    PubMed Central

    1992-01-01

    B cell chronic lymphocytic leukemia (CLL) is the malignant, monoclonal equivalent of a human CD5+ B cell. Previous studies have shown that the VH and VL genes rearranged and/or expressed in CLL have few and apparently random mutations. However, in this study, we have found that the rearranged VH251 gene, one of the three-membered VH5 family, has extensive and selective mutations in B-CLL cells. Somatic mutation at the nucleotide level is 6.03% in B-CLLs whereas the somatic mutation levels are much lower in CD5+ and CD5- cord B cells, adult peripheral blood B cells, and Epstein-Barr virus-transformed CD5+ B cell lines (0.45, 0.93, and 1.92%, respectively). Complementary determining region 1 (CDR1) mutation in CLLs is particularly prevalent, and interchanges in CDRs often lead to acquisition of charge. Analysis of somatic mutations and mutations to charged residues demonstrated that the mutations in CLLs are highly selected. PMID:1402653

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

    PubMed

    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. PMID:26336800

  10. Novel Cryptic Rearrangements in Adult B-Cell Precursor Acute Lymphoblastic Leukemia Involving the MLL Gene.

    PubMed

    Othman, Moneeb A K; Grygalewicz, Beata; Pienkowska-Grela, Barbara; Rincic, Martina; Rittscher, Katharina; Melo, Joana B; Carreira, Isabel M; Meyer, Britta; Marzena, Watek; Liehr, Thomas

    2015-05-01

    MLL (mixed-lineage-leukemia) gene rearrangements are typical for acute leukemia and are associated with an aggressive course of disease, with a worse outcome than comparable case, and thus require intensified treatment. Here we describe a 69-year-old female with adult B cell precursor acute lymphoblastic leukemia (BCP-ALL) with hyperleukocytosis and immunophenotype CD10- and CD19+ with cryptic MLL rearrangements. G-banding at the time of diagnosis showed a normal karyotype: 46,XX. Molecular cytogenetics using multitude multicolor banding (mMCB) revealed a complex rearrangement of the two copies of chromosome 11. However, a locus-specific probe additionally identified that the MLL gene at 11q23.3 was disrupted, and that the 5' region was inserted into the chromosomal sub-band 4q21; thus the aberration involved three chromosomes and five break events. Unfortunately, the patient died six months after the initial diagnosis from serious infections and severe complications. Overall, the present findings confirm that, by far not all MLL aberrations are seen by routine chromosome banding techniques and that fluorescence in situ hybridization (FISH) should be regarded as standard tool to access MLL rearrangements in patients with BCP-ALL. PMID:25699572

  11. Signal-dependent dynamics of transcription factor translocation controls gene expression.

    PubMed

    Hao, Nan; O'Shea, Erin K

    2012-01-01

    Information about environmental stimuli is often transmitted using common signaling molecules, but the mechanisms that ensure signaling specificity are not entirely known. Here we show that the identities and intensities of different stresses are transmitted by modulation of the amplitude, duration or frequency of nuclear translocation of the Saccharomyces cerevisiae general stress response transcription factor Msn2. Through artificial control of the dynamics of Msn2 translocation, we reveal how distinct dynamical schemes differentially affect reporter gene expression. Using a simple model, we predict stress-induced reporter gene expression from single-cell translocation dynamics. We then demonstrate that the response of natural target genes to dynamical modulation of Msn2 translocation is influenced by differences in the kinetics of promoter transitions and transcription factor binding properties. Thus, multiple environmental signals can trigger qualitatively different dynamics of a single transcription factor and influence gene expression patterns. PMID:22179789

  12. 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

    PubMed Central

    Bøgsted, Martin; Bilgrau, Anders E.; Wardell, Christopher P.; Bertsch, Uta; Schmitz, Alexander; Bødker, Julie S.; Kjeldsen, Malene K.; Goldschmidt, Hartmut; Morgan, Gareth J.; Dybkaer, Karen; Johnsen, Hans E.

    2013-01-01

    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. PMID:24376673

  13. Reconstruction of canine diffuse large B-cell lymphoma gene regulatory network: detection of functional modules and hub genes.

    PubMed

    Zamani-Ahmadmahmudi, M; Najafi, A; Nassiri, S M

    2015-01-01

    Lymphoma is one of the most common malignancies in dogs. Canine lymphoma is similar to human non-Hodgkin's lymphoma (NHL) with shared clinical presentation and histopathological features. This study reports the construction of a comprehensive gene regulatory network (GRN) for canine diffuse large B-cell lymphoma (DLBCL), the most common type of canine lymphoma, and performs analysis for detection of major functional modules and hub genes (the most important genes in a GRN). The canine DLBCL GRN was reconstructed from gene expression data (NCBI GEO dataset: GSE30881) using the STRING and MiMI interaction databases. Reconstructed GRNs were then assessed, using various bioinformatics programmes, in order to analyze network topology and identify major pathways and hub genes. The resultant network from both interaction databases had a logically scale-free pattern. Gene ontology (GO) analysis revealed cell activation, cell cycle phase, immune effector process, immune system development, immune system process, integrin-mediated signalling pathway, intracellular protein kinase cascade, intracellular signal transduction, leucocyte activation and differentiation, lymphocyte activation and differentiation as major GO terms in the biological processes of the networks. Moreover, bioinformatics analysis showed E2F1, E2F4, PTEN, CDKN1A, PCNA, DKC1, MNAT1, NDUFB4, ATP5J, PRKDC, BRCA1, MYCN, RFC4 and POLA1 as the most important hub genes. The phosphatidyl inositol signalling system, P53 signalling pathway, Rac CycD pathway, G1/S checkpoint, chemokine signalling pathway and telomere maintenance were the main signalling pathways in which the protein products of the hub genes are involved. PMID:25678421

  14. Gene therapy delivery of myelin oligodendrocyte glycoprotein (MOG) via hematopoietic stem cell transfer induces MOG-specific B cell deletion.

    PubMed

    Chung, Jie-Yu; Figgett, William; Fairfax, Kirsten; Bernard, Claude; Chan, James; Toh, Ban-Hock; Mackay, Fabienne; Alderuccio, Frank

    2014-03-15

    The various mechanisms that have been described for immune tolerance govern our ability to control self-reactivity and minimize autoimmunity. However, the capacity to genetically manipulate the immune system provides a powerful avenue to supplement this natural tolerance in an Ag-specific manner. We have previously shown in the mouse model of experimental autoimmune encephalomyelitis that transfer of bone marrow (BM) transduced with retrovirus encoding myelin oligodendrocyte glycoprotein (MOG) promotes disease resistance and CD4(+) T cell deletion within the thymus. However, the consequence of this strategy on B cell tolerance is not known. Using BM from IgH(MOG) mice that develop MOG-specific B cell receptors, we generated mixed chimeras together with BM-encoding MOG. In these animals, the development of MOG-specific B cells was abrogated, resulting in a lack of MOG-specific B cells in all B cell compartments examined. This finding adds a further dimension to our understanding of the mechanisms of tolerance that are associated with this gene therapy approach to treating autoimmunity and may have important implications for Ab-mediated autoimmune disorders. PMID:24532581

  15. Targeted Chromosomal Translocations and Essential Gene Knockout Using CRISPR/Cas9 Technology in Caenorhabditis elegans.

    PubMed

    Chen, Xiangyang; Li, Mu; Feng, Xuezhu; Guang, Shouhong

    2015-12-01

    Many genes play essential roles in development and fertility; their disruption leads to growth arrest or sterility. Genetic balancers have been widely used to study essential genes in many organisms. However, it is technically challenging and laborious to generate and maintain the loss-of-function mutations of essential genes. The CRISPR/Cas9 technology has been successfully applied for gene editing and chromosome engineering. Here, we have developed a method to induce chromosomal translocations and produce genetic balancers using the CRISPR/Cas9 technology and have applied this approach to edit essential genes in Caenorhabditis elegans. The co-injection of dual small guide RNA targeting genes on different chromosomes resulted in reciprocal translocation between nonhomologous chromosomes. These animals with chromosomal translocations were subsequently crossed with animals that contain normal sets of chromosomes. The F1 progeny were subjected to a second round of Cas9-mediated gene editing. Through this method, we successfully produced nematode strains with specified chromosomal translocations and generated a number of loss-of-function alleles of two essential genes (csr-1 and mes-6). Therefore, our method provides an easy and efficient approach to generate and maintain loss-of-function alleles of essential genes with detailed genetic background information. PMID:26482793

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

    PubMed Central

    2014-01-01

    Background This report describes a method for the generation of global gene expression profiles from low frequent B-cell subsets by using fluorescence-activated cell sorting and RNA amplification. However, some of the differentiating compartments involve a low number of cells 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 to 33,000 and with frequencies varying between 0.1 and 10 percent were sorted, subjected to mRNA purification, amplified by the NuGEN protocol and finally analysed by the Affymetrix platform. Results Following a step by step strategy, each step in the workflow was validated and the sorting/storage conditions optimized as described in this report. First, an analysis of four cancer cell lines on Affymetrix arrays, using either 100 ng RNA labelled with the Ambion standard protocol or 1 ng RNA amplified and labelled by the NuGEN protocol, revealed a significant correlation of gene expressions (r???0.9 for all). Comparison of qPCR data in samples with or without amplification for 8 genes showed that a relative difference between six cell lines was preserved (r???0.9). Second, a comparison of cells sorted into PrepProtect, RNAlater or directly into lysis/binding buffer showed a higher yield of purified mRNA following storage in lysis/binding buffer (p?B-cell subsets validated by the cluster of differentiation (CD) membrane profile was highly concordant with the transcriptional gene expression (p-values <0.001). Finally, in normal bone marrow and tonsil samples, eight evaluated genes were expressed in accordance with the biology of lymphopoiesis (p-values?gene-specific B-cell atlas. Conclusion A description of the implementation and validation of commercially available kits in the laboratory has been examined. This included steps for cell sorting, cell lysis/stabilization, RNA isolation, RNA concentration and amplification for microarray analysis. The workflow described in this report will enable the generation of microarray data from minor sorted B-cell subsets. PMID:24483235

  17. Loss of the TEL/ETV6 gene by a second translocation in ALL patients with t(12;21).

    PubMed

    Coniat, M B; Poirel, H; Leblanc, T; Bernard, O A; Berger, R

    1999-10-01

    Inactivation of the non translocated TEL/ETV6 gene is commonly associated with translocation (12;21) of acute lymphoblastic leukemia (ALL). Translocations involving the short arm of chromosome 12 were analysed in two children with t(12;21) ALL. Fluorescence in situ hybridation studies showed that these associated translocations resulted in loss of TEL/ETV6. While hybridization with a YAC probe covering TEL/ETV6 was positive in one patient, analysis with cosmid probes covering the gene demonstrated that the gene was in fact deleted. It is concluded that deletions involving TEL/ETV6 can remain undetected by FISH using only YAC probes. PMID:10573134

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

    Cancer.gov

    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).

  19. Blimp-1/PRDM1 regulates the transcription of human CS1 (SLAMF7) gene in NK and B cells.

    PubMed

    Kim, Jong R; Mathew, Stephen O; Mathew, Porunelloor A

    2016-01-01

    CS1 (CRACC/CD319/SLAMF7) is a member of SLAM (Signaling Lymphocyte Activation Molecule) family receptors and is expressed on NK cells, a subset of CD8(+) T lymphocytes, activated monocytes, mature dendritic cells and activated B cells. In NK cells, CS1 signaling induces cytolytic function of NK cells against targets whereas in B cells CS1 induces proliferation and autocrine cytokine production. CS1 is upregulated in multiple myeloma cells and contributes to clonogenic growth and tumorigenicity. However, the mechanism of CS1 upregulation is unknown. In this study, we analyzed the transcriptional regulation of human CS1 gene in NK and B cells. The promoter region of CS1 contains a Blimp-1/PRDM1 binding site and relative luciferase activities of successive deletion mutants of CS1 promoter were different between Blimp-1/PRDM1-positive and Blimp-1/PRDM1-negative cells. Proximal region of CS1 promoter contains a CAAT box and atypical TATA-box that might result in common transcription initiation at -29 nucleotides upstream of the ATG translation start codon. Electrophoretic Mobility Shift Assay (EMSA) and Chromatin Immunoprecipitation (ChIP) assays revealed Blimp-1/PRDM1 binds to the CS1 promoter region. Mutating the Blimp-1/PRDM1 site at -750 to -746 decreased the transcriptional activity of CS1 promoter implicating a trans-activating function of Blimp-1/PRDM1 in human CS1 gene regulation. The finding that Blimp-1/PRDM1 enhances transcription of CS1 gene in multiple myeloma cells may help in developing novel strategies for therapeutic intervention in multiple myeloma. PMID:26310579

  20. Restricted immunoglobulin variable region gene usage by normal Ly-1 (CD5+) B cells that recognize phosphatidyl choline

    PubMed Central

    1989-01-01

    5-15% of lymphocytes in the peritoneums of normal adult B10.H-2aH- 4bp/Wts (2a4b) mice are CD5+ (Ly-1) B cells that recognize phosphatidyl choline (PtC), a phospholipid component of all mammalian cells. We produced a set of IgM-secreting hybridomas from the peritoneal cells of normal, adult 2a4b mice. We found that this set of hybridomas shows a similarly high frequency of antibodies specific for PtC (21 of 86) that also react with bromelain-treated mouse erythrocytes. Restriction fragment analysis of Ig gene rearrangements and analysis of expressed Ig idiotypes reveal that these cells use a restricted set of variable region genes to generate the PtC-specific antibodies. The Ig genes used by the PtC-specific hybridomas appear to be the same as those found in the PtC-specific Ly-1 B cell lymphomas, CH27 and CH34. PMID:2499651

  1. Epstein - Barr Virus Transforming Protein LMP-1 Alters B Cells Gene Expression by Promoting Accumulation of the Oncoprotein ?Np73?

    PubMed Central

    Accardi, Rosita; Fathallah, Ikbal; Gruffat, Henri; Mariggiò, Giuseppe; Le Calvez-Kelm, Florence; Voegele, Catherine; Bartosch, Birke; Hernandez-Vargas, Hector; McKay, James; Sylla, Bakary S.; Manet, Evelyne; Tommasino, Massimo

    2013-01-01

    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 ?Np73?, 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 ?Np73? promoter. A specific chemical inhibitor of JNK-1 or silencing JNK-1 expression strongly down-regulated ?Np73? mRNA levels in LMP-1-containing cells. Accordingly, LMP-1 mutants deficient to activate JNK-1 did not induce ?Np73? accumulation. The recruitment of p73 to the ?Np73? promoter correlated with the displacement of the histone-lysine N-methyltransferase EZH2 which is part of the transcriptional repressive polycomb 2 complex. Inhibition of ?Np73? 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 ?Np73? down-regulation. Together, these findings reveal a novel EBV mechanism that appears to play an important role in the transformation of primary B cells. PMID:23516355

  2. A Strong Promoter Activity of Pre-B Cell Stage-Specific Crlz1 Gene Is Caused by One Distal LEF-1 and Multiple Proximal Ets Sites

    PubMed Central

    Park, Sung-Kyun; Son, Youngsook; Kang, Chang-Joong

    2011-01-01

    The promoter of pre-B cell stage-specific Crlz1 gene, whose protein translocates the cytoplasmic core binding factor ? (CBF?) into the nucleus and thereby allows its heterodimerization with Runx, has a very strong activity, which is about 25% of cytomegalovirus (CMV) promoter activity and comparable to the EF-1? promoter activity. Its transcription start site was mapped at 155 nt upstream of translation initiation codon. 5?-truncation analysis of charged amino acids rich leucine zipper 1 (Crlz1) promoter revealed that one distal region from -612 to -536 and one proximal region from -198 to -100 as numbered from the transcription start site were critical for the promoter activity. The 3?-truncation analysis of the promoter revealed that the basal promoter sequence around the transcription start site, which should be necessary for the assembly of transcription initiation complex and the start of RNA polymerase II, was also essential, although not sufficient by itself. When transcription factor binding sites within those two critical regions were searched by in vivo footprinting, one distal LEF-1 and multiple proximal Ets consensus-like sites were found to be footprinted. Indeed, the protein causing a footprint over the distal region was found to be LEF-1, and the ones causing three footprints over the proximal region were found to be such Ets family members as Fli-1 and GABP, as verified by EMSA and ChIP analyses. Furthermore, those LEF-1 and Ets sites were shown to drive additively a strong transcription of Crlz1 gene. PMID:21544627

  3. X-linked intellectual disability related genes disrupted by balanced X-autosome translocations.

    PubMed

    Moysés-Oliveira, Mariana; Guilherme, Roberta Santos; Meloni, Vera Ayres; Di Battista, Adriana; de Mello, Claudia Berlim; Bragagnolo, Silvia; Moretti-Ferreira, Danilo; Kosyakova, Nadezda; Liehr, Thomas; Carvalheira, Gianna Maria; Melaragno, Maria Isabel

    2015-12-01

    Detailed molecular characterization of chromosomal rearrangements involving X-chromosome has been a key strategy in identifying X-linked intellectual disability-causing genes. We fine-mapped the breakpoints in four women with balanced X-autosome translocations and variable phenotypes, in order to investigate the corresponding genetic contribution to intellectual disability. We addressed the impact of the gene interruptions in transcription and discussed the consequences of their functional impairment in neurodevelopment. Three patients presented with cognitive impairment, reinforcing the association between the disrupted genes (TSPAN7-MRX58, KIAA2022-MRX98, and IL1RAPL1-MRX21/34) and intellectual disability. While gene expression analysis showed absence of TSPAN7 and KIAA2022 expression in the patients, the unexpected expression of IL1RAPL1 suggested a fusion transcript ZNF611-IL1RAPL1 under the control of the ZNF611 promoter, gene disrupted at the autosomal breakpoint. The X-chromosomal breakpoint definition in the fourth patient, a woman with normal intellectual abilities, revealed disruption of the ZDHHC15 gene (MRX91). The expression assays did not detect ZDHHC15 gene expression in the patient, thus questioning its involvement in intellectual disability. Revealing the disruption of an X-linked intellectual disability-related gene in patients with balanced X-autosome translocation is a useful tool for a better characterization of critical genes in neurodevelopment. © 2015 Wiley Periodicals, Inc. PMID:26290131

  4. Four novel non-random chromosome rearrangements in B-cell chronic lymphocytic leukaemia: 6p24-25 and 12p12-13 translocations, 4q21 anomalies and monosomy 21.

    PubMed

    Cuneo, A; Roberti, M G; Bigoni, R; Minotto, C; Bardi, A; Milani, R; Tieghi, A; Campioni, D; Cavazzini, F; De Angeli, C; Negrini, M; Castoldi, G

    2000-03-01

    Nine patients with previously unreported chromosome changes were identified among 209 B-cell chronic lymphocytic leukaemia (CLL) cases: three patients had a translocation involving 6p24-25; three had a 12p12-13 translocation; two had 4q21 involvement (one with coexisting 6p anomaly); and two had monosomy 21. Interphase fluorescence in situ hybridization (FISH) detected some cryptic aberrations (+12, 6q-, 17p-, 11q-) in those patients with 6p translocations, whereas only a cytogenetically undetected 13q14 deletion was found in the remaining cases. Atypical morphology was noted in six cases, including both cases with monosomy 21, two cases with 6p and 4q21 anomaly and one case with 12p involvement. Four of these cases also had more than one phenotype deviation with respect to the classical CLL phenotype. Disease progression after 21-51 months (median 41) was noted in two cases with 6p and 4q21 involvement and in one case with 12p anomaly and monosomy 21. We arrived at the following conclusions: (i) 6p24-25 and, possibly, 4q21 lesions represent non-random events in CLL, occurring in association with other well-known unbalanced rearrangements; (ii) 12p rearrangements and monosomy 21 may possibly represent early chromosome defects that are not associated with the classical DNA gains and losses known to be present in the majority of CLL; and (iii) atypical morphology and immunophenotype as well as disease progression were frequently observed in these cases PMID:10759714

  5. Global mapping of c-Myc binding sites and target gene networks in human B cells

    E-print Network

    Weng, Zhiping

    . Using gene expression profiles with ChIP-PET, we identified 668 direct Myc-regulated gene targets that dimerizes with Max to bind the DNA sequence 5 -CACGTG-3 , known as an E box, and activates transcription (3 and compiled in the Myc target gene database (www.myccancergene.org) (7). Recently, high- throughput expression

  6. High concordance of gene expression profiling-correlated immunohistochemistry algorithms in diffuse large B-cell lymphoma, not otherwise specified.

    PubMed

    Hwang, Hee Sang; Park, Chan-Sik; Yoon, Dok Hyun; Suh, Cheolwon; Huh, Jooryung

    2014-08-01

    Diffuse large B-cell lymphoma (DLBCL) is classified into prognostically distinct germinal center B-cell (GCB) and activated B-cell subtypes by gene expression profiling (GEP). Recent reports suggest the role of GEP subtypes in targeted therapy. Immunohistochemistry (IHC) algorithms have been proposed as surrogates of GEP, but their utility remains controversial. Using microarray, we examined the concordance of 4 GEP-correlated and 2 non-GEP-correlated IHC algorithms in 381 DLBCLs, not otherwise specified. Subtypes and variants of DLBCL were excluded to minimize the possible confounding effect on prognosis and phenotype. Survival was analyzed in 138 cyclophosphamide, adriamycin, vincristine, and prednisone (CHOP)-treated and 147 rituximab plus CHOP (R-CHOP)-treated patients. Of the GEP-correlated algorithms, high concordance was observed among Hans, Choi, and Visco-Young algorithms (total concordance, 87.1%; ? score: 0.726 to 0.889), whereas Tally algorithm exhibited slightly lower concordance (total concordance 77.4%; ? score: 0.502 to 0.643). Two non-GEP-correlated algorithms (Muris and Nyman) exhibited poor concordance. Compared with the Western data, incidence of the non-GCB subtype was higher in all algorithms. Univariate analysis showed prognostic significance for Hans, Choi, and Visco-Young algorithms and BCL6, GCET1, LMO2, and BCL2 in CHOP-treated patients. On multivariate analysis, Hans algorithm retained its prognostic significance. By contrast, neither the algorithms nor individual antigens predicted survival in R-CHOP treatment. The high concordance among GEP-correlated algorithms suggests their usefulness as reliable discriminators of molecular subtype in DLBCL, not otherwise specified. Our study also indicates that prognostic significance of IHC algorithms may be limited in R-CHOP-treated Asian patients because of the predominance of the non-GCB type. PMID:24705314

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

    SciTech Connect

    Uchiyama, Toru; Kumaki, Satoru . E-mail: kumakis@idac.tohoku.ac.jp; Ishikawa, Yoshinori; Onodera, Masafumi; Sato, Miki; Du, Wei; Sasahara, Yoji; Tanaka, Nobuyuki; Sugamura, Kazuo; Tsuchiya, Shigeru

    2006-03-10

    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 {gamma}c chain cDNA and Herpes simplex virus thymidine kinase gene. After confirmation of functional reconstitution of the {gamma}c chain, the cells were treated with ganciclovir (GCV). The {gamma}c chain positive cells were eliminated under low concentration without cytotoxicity on untransduced cells and have not reappeared at least for 5 months. Furthermore, the {gamma}c 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.

  8. Human balanced translocation and mouse gene inactivation implicate Basonuclin 2 in distal urethral development

    PubMed Central

    Bhoj, Elizabeth J; Ramos, Purita; Baker, Linda A; Cost, Nicholas; Nordenskjöld, Agneta; Elder, Frederick F; Bleyl, Steven B; Bowles, Neil E; Arrington, Cammon B; Delhomme, Brigitte; Vanhoutteghem, Amandine; Djian, Philippe; Zinn, Andrew R

    2011-01-01

    We studied a man with distal hypospadias, partial anomalous pulmonary venous return, mild limb-length inequality and a balanced translocation involving chromosomes 9 and 13. To gain insight into the etiology of his birth defects, we mapped the translocation breakpoints by high-resolution comparative genomic hybridization (CGH), using chromosome 9- and 13-specific tiling arrays to analyze genetic material from a spontaneously aborted fetus with unbalanced segregation of the translocation. The chromosome 13 breakpoint was ?400?kb away from the nearest gene, but the chromosome 9 breakpoint fell within an intron of Basonuclin 2 (BNC2), a gene that encodes an evolutionarily conserved nuclear zinc-finger protein. The BNC2/Bnc2 gene is abundantly expressed in developing mouse and human periurethral tissues. In all, 6 of 48 unrelated subjects with distal hypospadias had nine novel nonsynonymous substitutions in BNC2, five of which were computationally predicted to be deleterious. In comparison, two of 23 controls with normal penile urethra morphology, each had a novel nonsynonymous substitution in BNC2, one of which was predicted to be deleterious. Bnc2?/? mice of both sexes displayed a high frequency of distal urethral defects; heterozygotes showed similar defects with reduced penetrance. The association of BNC2 disruption with distal urethral defects and the gene's expression pattern indicate that it functions in urethral development. PMID:21368915

  9. Human balanced translocation and mouse gene inactivation implicate Basonuclin 2 in distal urethral development.

    PubMed

    Bhoj, Elizabeth J; Ramos, Purita; Baker, Linda A; Garg, Vidu; Cost, Nicholas; Nordenskjöld, Agneta; Elder, Frederick F; Bleyl, Steven B; Bowles, Neil E; Arrington, Cammon B; Delhomme, Brigitte; Vanhoutteghem, Amandine; Djian, Philippe; Zinn, Andrew R

    2011-05-01

    We studied a man with distal hypospadias, partial anomalous pulmonary venous return, mild limb-length inequality and a balanced translocation involving chromosomes 9 and 13. To gain insight into the etiology of his birth defects, we mapped the translocation breakpoints by high-resolution comparative genomic hybridization (CGH), using chromosome 9- and 13-specific tiling arrays to analyze genetic material from a spontaneously aborted fetus with unbalanced segregation of the translocation. The chromosome 13 breakpoint was ?400 ?kb away from the nearest gene, but the chromosome 9 breakpoint fell within an intron of Basonuclin 2 (BNC2), a gene that encodes an evolutionarily conserved nuclear zinc-finger protein. The BNC2/Bnc2 gene is abundantly expressed in developing mouse and human periurethral tissues. In all, 6 of 48 unrelated subjects with distal hypospadias had nine novel nonsynonymous substitutions in BNC2, five of which were computationally predicted to be deleterious. In comparison, two of 23 controls with normal penile urethra morphology, each had a novel nonsynonymous substitution in BNC2, one of which was predicted to be deleterious. Bnc2(-/-) mice of both sexes displayed a high frequency of distal urethral defects; heterozygotes showed similar defects with reduced penetrance. The association of BNC2 disruption with distal urethral defects and the gene's expression pattern indicate that it functions in urethral development. PMID:21368915

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

    PubMed Central

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

    2014-01-01

    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 PMID:25544807

  11. A seven-gene expression panel distinguishing clonal expansions of pre-leukemic and chronic lymphocytic leukemia B cells from normal B lymphocytes.

    PubMed

    McCarthy, Brian A; Yancopoulos, Sophia; Tipping, Mike; Yan, Xiao-Jie; Wang, Xue Ping; Bennett, Fiona; Li, Wentian; Lesser, Martin; Paul, Santanu; Boyle, Erin; Moreno, Carolina; Catera, Rosa; Messmer, Bradley T; Cutrona, Giovanna; Ferrarini, Manlio; Kolitz, Jonathan E; Allen, Steven L; Rai, Kanti R; Rawstron, Andrew C; Chiorazzi, Nicholas

    2015-12-01

    Chronic lymphocytic leukemia (CLL) is a clonal disease of B lymphocytes manifesting as an absolute lymphocytosis in the blood. However, not all lymphocytoses are leukemic. In addition, first-degree relatives of CLL patients have an ~15 % chance of developing a precursor condition to CLL termed monoclonal B cell lymphocytosis (MBL), and distinguishing CLL and MBL B lymphocytes from normal B cell expansions can be a challenge. Therefore, we selected FMOD, CKAP4, PIK3C2B, LEF1, PFTK1, BCL-2, and GPM6a from a set of genes significantly differentially expressed in microarray analyses that compared CLL cells with normal B lymphocytes and used these to determine whether we could discriminate CLL and MBL cells from B cells of healthy controls. Analysis with receiver operating characteristics and Bayesian relevance determination demonstrated good concordance with all panel genes. Using a random forest classifier, the seven-gene panel reliably distinguished normal polyclonal B cell populations from expression patterns occurring in pre-CLL and CLL B cell populations with an error rate of 2 %. Using Bayesian learning, the expression levels of only two genes, FMOD and PIK3C2B, correctly distinguished 100 % of CLL and MBL cases from normal polyclonal and mono/oligoclonal B lymphocytes. Thus, this study sets forth effective computational approaches that distinguish MBL/CLL from normal B lymphocytes. The findings also support the concept that MBL is a CLL precursor. PMID:26318878

  12. Germline Variation in Complement Genes and Event-Free Survival in Follicular and Diffuse Large B-Cell Lymphoma

    PubMed Central

    Charbonneau, Bridget; Maurer, Matthew J.; Fredericksen, Zachary S.; Zent, Clive S.; Link, Brian K.; Novak, Anne J.; Ansell, Stephen M.; Weiner, George J.; Wang, Alice H.; Witzig, Thomas E.; Dogan, Ahmet; Slager, Susan L.; Habermann, Thomas M.; Cerhan, James R.

    2013-01-01

    The complement pathway plays a central role in innate immunity, and also functions as a regulator of the overall immune response. We evaluated whether polymorphisms in complement genes are associated with event-free survival (EFS) in follicular (FL) and diffuse large B-cell (DLBCL) lymphoma. We genotyped 167 single nucleotide polymorphisms (SNPs) from 30 complement pathway genes in a prospective cohort study of newly diagnosed FL (N=107) and DLBCL (N=82) patients enrolled at the Mayo Clinic from 2002–2005. Cox regression was used to estimate Hazard Ratios (HRs) for individual SNPs with EFS, adjusting for FLIPI or IPI and treatment. For gene-level analyses, we used a principal components based gene-level test. In gene-level analyses for FL EFS, CFH (p=0.009), CD55 (p=0.006), CFHR5 (p=0.01), C9 (p=0.02), CFHR1 (p=0.03), and CD46 (p=0.03) were significant at p<0.05, and these genes remained noteworthy after accounting for multiple testing (q<0.15). SNPs in CFH, CFHR1, and CFHR5 showed stronger associations among patients receiving any rituximab, while SNPs from CD55 and CD46 showed stronger associations among patients who were observed. For DLBCL, only CLU (p=0.001) and C7 (p=0.03) were associated with EFS, but did not remain noteworthy after accounting for multiple testing (q>0.15). Genes from the Regulators of Complement Activation (CFH, CD55, CFHR1, CFHR5, CD46) at 1q32-q32.1, along with C9, were associated with FL EFS after adjusting for clinical variables, and if replicated, these findings add further support for the role of host innate immunity in FL prognosis. PMID:22718493

  13. TP53 mutations are frequent events in double-hit B-cell lymphomas with MYC and BCL2 but not MYC and BCL6 translocations.

    PubMed

    Gebauer, Niklas; Bernard, Veronica; Gebauer, Wolfgang; Thorns, Christoph; Feller, Alfred C; Merz, Hartmut

    2015-01-01

    Double-hit lymphomas (DHL) with MYC and either BCL2 or BCL6 rearrangements are rare neoplasms with an aggressive clinical presentation and grim prognosis. Moreover, molecular characterization of DHL remains insufficient, and especially the role of TP53 pathway disruption is unknown. We employed a next-generation sequencing approach to investigate the mutational status of TP53 in DHL and correlated genomic data with immunohistochemical reactivity for p53. We identified TP53 mutations in MYC+/BCL2+ lymphomas at a frequency intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. Remarkably, TP53 mutations were particularly scarce in MYC+/BCL6+ lymphomas. Our findings indicate a significant difference between these two types of DHL at a molecular level with pathogenetic implications, as arguably, TP53 mutations inhibiting p53 mediated promotion of apoptosis pose a synergistic advantage in clonal evolution of cells with malignantly enforced overexpression of BCL2. Immunohistochemical staining appears to be a sensitive surrogate of TP53 mutation status with moderate specificity. PMID:24679006

  14. Gene profiling of canine B-cell lymphoma reveals germinal center and post-germinal center subtypes with different survival times, modeling human DLBCL

    PubMed Central

    Richards, Kristy L.; Motsinger-Reif, Alison A.; Chen, Hsiao-wei; Fedoriw, Yuri; Fan, Cheng; Nielsen, Dahlia M.; Small, George W.; Thomas, Rachael; Smith, Chris; Dave, Sandeep S.; Perou, Charles M.; Breen, Matthew; Borst, Luke B.; Suter, Steven E.

    2013-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype, and fewer than half of patients are cured with standard front-line therapy. To improve therapeutic options, better animal models that accurately mimic human DLBCL (hDLBCL) are needed. Canine DLBCL (cDLBCL), one of the most common cancers in veterinary oncology, is morphologically similar to hDLBCL and is treated using similar chemotherapeutic protocols. With genomic technologies, it is now possible to molecularly evaluate dogs as a potential large-animal model for hDLBCL. We evaluated canine B-cell lymphomas (cBCLs) using immunohistochemistry and gene expression profiling. Canine B-cell lymphoma expression profiles were similar in many ways to hDLBCLs. For instance, a subset had increased expression of NF-?B pathway genes, mirroring human activated B-cell (ABC)-type DLBCL. Furthermore, immunoglobulin heavy chain (IGH) ongoing mutation status, which is correlated with ABC/germinal center B-cell (GCB) cell of origin in hDLBCL, separated cBCL into two groups with statistically different progression-free and overall survival times. In contrast with hDLBCL, cBCL rarely expressed BCL6 and MUM1/IRF4 by immunohistochemistry. Collectively, these studies identify molecular similarities to hDLBCL that introduce pet dogs as a representative model of hDLBCL for future studies, including therapeutic clinical trials. PMID:23783577

  15. MYC/BCL2 double-hit high-grade B-cell lymphoma.

    PubMed

    Li, Shaoying; Lin, Pei; Young, Ken H; Kanagal-Shamanna, Rashmi; Yin, C Cameron; Medeiros, L Jeffrey

    2013-09-01

    Double-hit lymphoma (DHL) has been defined by others as a B-cell lymphoma with MYC/8q24 rearrangement in combination with a translocation involving another gene, such as BCL2, BCL3, or BCL6. The most common form of DHL has translocations involving MYC and BCL2, also known as MYC/BCL2 DHL. In recent years, a number of case series of MYC/BCL2 DHL have been published. Most cases of MYC/BCL2 DHL morphologically resemble diffuse large B-cell lymphoma (DLBCL) or B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma. These tumors are of B-cell lineage, have a germinal center B-cell immunophenotype with a high proliferation rate, and a complex karyotype. Patients with these tumors have an aggressive clinical course and poor prognosis despite high-intensity chemotherapy. More recently, studies have suggested expanding the spectrum of MYC/BCL2 DHL to include cases that have concurrent MYC and BCL2 cytogenetic abnormalities, but not necessarily translocations. In addition, overexpression of MYC and BCL2 has been shown in an appreciable subset of DLBCL tumors. These tumors show overlap with MYC/BCL2 DHL, but are not equivalent. In this review, we discuss the clinicopathologic, immunophenotypic, cytogenetic, and prognostic features of MYC/BCL2 DHL. PMID:23939148

  16. Translocations used to generate chromosome segment duplications in Neurospora can disrupt genes and create novel open reading frames.

    PubMed

    Singh, Parmit K; Iyer, Srividhya V; Sowjanya, T Naga; Raj, B Kranthi; Kasbekar, Durgadas P

    2010-12-01

    In Neurospora crassa, crosses between normal sequence strains and strains bearing some translocations can yield progeny bearing a duplication (Dp) of the translocated chromosome segment. Here, 30 breakpoint junction sequences of 12 Dp-generating translocations were determined. The breakpoints disrupted 13 genes (including predicted genes), and created 10 novel open reading frames. Insertion of sequences from LG III into LG I as translocation T(UK8-18) disrupts the eat-3 gene, which is the ortholog of the Podospora anserine gene ami1. Since ami1-homozygous Podospora crosses were reported to increase the frequency of repeat-induced point mutation (RIP), we performed crosses homozygous for a deficiency in eat-3 to test for a corresponding increase in RIP frequency. However, our results suggested that, unlike in Podospora, the eat-3 gene might be essential for ascus development in Neurospora. Duplication-heterozygous crosses are generally barren in Neurospora; however, by using molecular probes developed in this study, we could identify Dp segregants from two different translocation-heterozygous crosses, and using these we found that the barren phenotype of at least some duplication-heterozygous crosses was incompletely penetrant. PMID:21289436

  17. Expression of human {beta}-defensin-2 gene induced by CpG-DNA in human B cells

    SciTech Connect

    Han, Su Ho; Kim, Young-Eun; Park, Jeong-A; Park, Jae-Bong; Kim, Yong-Sun; Lee, Younghee; Choi, Ihn-Geun; Kwon, Hyung-Joo; Center for Medical Science Research, College of Medicine, Hallym University, Gangwon-do 200-702

    2009-11-20

    Defensins have a broad range of antimicrobial activity against bacteria, fungi, and viruses. The expression of human {beta}-defensin-2 (hBD-2) is prevalently observed in epithelial cells and is induced by bacterial infection. Here, we have shown that the expression of the hBD-2 gene and release of hBD-2 protein into the medium is up-regulated in response to CpG-DNA in human B cell line RPMI 8226. The induction of hBD-2 was dependent on CG sequence and phosphorothioate backbone-modification. This was also confirmed in primary human lymphocytes. To shed light on the molecular mechanism involved in hBD-2 induction by CpG-DNA, we examined the contribution of the NF-{kappa}B signaling pathway in RPMI 8226 cells. Suppression of MyD88 function and inhibition of NF-{kappa}B nuclear localization blocked hBD-2 induction. The NF-{kappa}B pathway inhibitors also abolished hBD-2 induction. These results may contribute to a better understanding on the therapeutic effects of CpG-DNA against infectious diseases.

  18. A Gene Selection Method for Survival Prediction in Diffuse Large B-Cell Lymphomas Patients using 1D Discrete Wavelet Transform

    PubMed Central

    FARHADIAN, Maryam; MAHJUB, Hossein; MOGHIMBEIGI, Abbas; POOROLAJAL, Jalal; MANSOORIZADEH, Muharram

    2014-01-01

    Abstract Background An important aspect of microarray studies includes the prediction of patient survival based on their gene expression profile. To deal with the high dimensionality of this data, use of a dimension reduction procedure along with the survival prediction model is necessary. This study aimed to present a new method based on wavelet transform for survival relevant gene selection. Methods The data included 2042 gene expression measurements from 40 patients with Diffuse Large B-Cell Lymphomas (DLBCL). The pre-processing gene expression data is decomposed using third level of the 1D discrete wavelet transform. The detail coefficients at levels 1 and 2 are filtered out and expression data reconstructed using the approximation and detailed coefficients at the third level. All the genes are then scored based on the t score. Then genes with the highest scores are selected. By using forward selection method in Cox regression model, significant genes were identified. Results The results showed wavelet-based gene selection method presents acceptable survival prediction. Using this method, six significant genes were selected. It was indicated the expression of GENE3359X and GENE3968X decreased the survival time, whereas the expression of GENE967X, GENE3980X, GENE3405X and GENE1813X increased the survival time. Conclusion Wavelet-based gene selection method is a potentially useful tool for the gene selection from microarray data in the context of survival analysis. PMID:25927038

  19. Identification and validation of a two-gene expression index for subtype classification and prognosis in Diffuse Large B-Cell Lymphoma

    PubMed Central

    Xu, Qinghua; Tan, Cong; Ni, Shujuan; Wang, Qifeng; Wu, Fei; Liu, Fang; Ye, Xun; Meng, Xia; Sheng, Weiqi; Du, Xiang

    2015-01-01

    The division of diffuse large B-cell lymphoma (DLBCL) into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes based on gene expression profiling has proved to be a landmark in understanding the pathogenesis of the disease. This study aims to identify a novel biomarker to facilitate the translation of research into clinical practice. Using a training set of 350 patients, we identified a two-gene expression signature, “LIMD1-MYBL1 Index”, which is significantly associated with cell-of-origin subtypes and clinical outcome. This two-gene index was further validated in two additional dataset. Tested against the gold standard method, the LIMD1-MYBL1 Index achieved 81% sensitivity, 89% specificity for ABC group and 81% sensitivity, 87% specificity for GCB group. The ABC group had significantly worse overall survival than the GCB group (hazard ratio?=?3.5, P?=?0.01). Furthermore, the performance of LIMD1-MYBL1 Index was satisfactory compared with common immunohistochemical algorithms. Thus, the LIMD1-MYBL1 Index had considerable clinical value for DLBCL subtype classification and prognosis. Our results might prompt the further development of this two-gene index to a simple assay amenable to routine clinical practice. PMID:25940947

  20. [Cloning of the gpp gene of Escherichia coli and the use of recBC, sbcB cells for inserting its mutant allele into the chromosomal structure].

    PubMed

    Belitski?, B R; Shakulov, R S

    1988-08-01

    The gpp gene involved in the pppGpp conversion into ppGpp in Escherichia coli cells was cloned and localized within the multicopy pBR322 plasmid. Amplification of the gpp gene leads to the decline of the intracellular level of pppGpp, which implies enhanced activity of the corresponding enzyme, guanosine pentaphosphatase. To inactivate the cloned gene, a fragment of the pUC4K plasmid containing the kan gene was inserted within the gpp gene. The functional chromosomal allele of the gpp gene was replaced by its inactivated gpp::kan allele, taking advantage of homologous recombination during the transformation of recBC, sbcB cells with the intact hybrid plasmid. This procedure is accompanied by plasmid elimination and may be used for the replacement of other loci of bacterial chromosome with appropriate cloned alleles. PMID:2849575

  1. DNA damage defines sites of recurrent chromosomal translocations in B lymphocytes

    PubMed Central

    Hakim, Ofir; Resch, Wolfgang; Yamane, Arito; Klein, Isaac; Kieffer-Kwon, Kyong-Rim; Jankovic, Mila; Oliveira, Thiago; Bothmer, Anne; Voss, Ty C.; Ansarah-Sobrinho, Camilo; Mathe, Ewy; Liang, Genqing; Cobell, Jesse; Nakahashi, Hirotaka; Robbiani, Davide F.; Nussenzweig, Andre; Hager, Gordon L.; Nussenzweig, Michel C.; Casellas, Rafael

    2012-01-01

    Recurrent chromosomal translocations underlie both haematopoietic and solid tumours. Their origin has been ascribed to selection of random rearrangements, targeted DNA damage, or frequent nuclear interactions between translocation partners; however, the relative contribution of each of these elements has not been measured directly or on a large scale. Here we examine the role of nuclear architecture and frequency of DNA damage in the genesis of chromosomal translocations by measuring these parameters simultaneously in cultured mouse B lymphocytes. In the absence of recurrent DNA damage, translocations between Igh or Myc and all other genes are directly related to their contact frequency. Conversely, translocations associated with recurrent site-directed DNA damage are proportional to the rate of DNA break formation, as measured by replication protein A accumulation at the site of damage. Thus, non-targeted rearrangements reflect nuclear organization whereas DNA break formation governs the location and frequency of recurrent translocations, including those driving B-cell malignancies. PMID:22314321

  2. Proposal of a Twin Aarginine Translocator System-Mediated Constraint against Loss of ATP Synthase Genes from Nonphotosynthetic Plastid Genomes.

    PubMed

    Kamikawa, Ryoma; Tanifuji, Goro; Ishikawa, Sohta A; Ishii, Ken-Ichiro; Matsuno, Yusei; Onodera, Naoko T; Ishida, Ken-Ichiro; Hashimoto, Tetsuo; Miyashita, Hideaki; Mayama, Shigeki; Inagaki, Yuji

    2015-10-01

    Organisms with nonphotosynthetic plastids often retain genomes; their gene contents provide clues as to the functions of these organelles. Yet the functional roles of some retained genes-such as those coding for ATP synthase-remain mysterious. In this study, we report the complete plastid genome and transcriptome data of a nonphotosynthetic diatom and propose that its ATP synthase genes may function in ATP hydrolysis to maintain a proton gradient between thylakoids and stroma, required by the twin arginine translocator (Tat) system for translocation of particular proteins into thylakoids. Given the correlated retention of ATP synthase genes and genes for the Tat system in distantly related nonphotosynthetic plastids, we suggest that this Tat-related role for ATP synthase was a key constraint during parallel loss of photosynthesis in multiple independent lineages of algae/plants. PMID:26048548

  3. Rac-mediated Stimulation of Phospholipase C?2 Amplifies B Cell Receptor-induced Calcium Signaling.

    PubMed

    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

    2015-07-10

    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 Ca(2+). 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 C?2 (PLC?2), 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 PLC?2 to functionally reconstitute cultured PLC?2-deficient DT40 B cells and to examine the effects of the Rac-PLC?2 interaction on BCR-mediated changes of intracellular Ca(2+) and regulation of Ca(2+)-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-PLC?2 interaction causes marked increases in the following: (i) sensitivity of B cells to BCR ligation; (ii) BCR-mediated Ca(2+) release from intracellular stores; (iii) Ca(2+) entry from the extracellular compartment; and (iv) nuclear translocation of the Ca(2+)-regulated nuclear factor of activated T cells. Hence, Rac-mediated stimulation of PLC?2 activity serves to amplify B cell receptor-induced Ca(2+) signaling. PMID:25903139

  4. Disruption of genes in the retinoid cascade may explain the microscopic neuroblastoma in a fetus with de novo unbalanced translocation

    SciTech Connect

    Goodman, A.B.

    1995-03-13

    The microscopic neuroblastoma in a fetus with de novo unbalanced translocation (3;10)(q21;q26) may be explained as the disruption of genes in the retinoid cascade, rather than simply a two-hit hypothesis for the development of tumor cells. 5 refs.

  5. Expression study of GLUT4 translocation-related genes in a porcine pre-diabetic model.

    PubMed

    Kristensen, Thea; Fredholm, Merete; Cirera, Susanna

    2015-12-01

    Obesity is a world-wide exponentially growing health problem that increases the risk of co-morbidities including metabolic syndrome, pre-diabetes, Type 2 Diabetes Mellitus (T2DM), and cancer. These co-morbidities are all complex conditions constituting a big challenge when searching for susceptibility genes. Identification of relevant genes, which could contribute to an earlier identification of individuals prone to develop diabetes, is urgently needed as many long-term complications can be avoided by preventive measures. Pre-diabetes is mainly associated with hyperglycemia; thus studying this phenotype might provide knowledge on relevant genes implicated in molecular mechanisms underlying pre-diabetes, and contributing to the development of T2DM. In the present study, two groups of pigs with high (HGG, N = 6) and low (NGG, N = 6) fasting plasma glucose level respectively were selected from a large pig population. Transcriptional levels of seven genes involved in the glucose transporter 4 (GLUT4) translocation pathway were studied by quantitative real-time PCR (qPCR) in diabetes relevant tissues (pancreas, adipose tissue, skeletal muscle, liver and kidney). Three of the genes, TBC (Tre-2, BUB2, CDC16) 1 Domain Family Member 4 (TBC1D4), insulin receptor and GLUT4 showed altered expression in some of the tissues. The expression pattern observed is in agreement with what has previously been reported in pre-diabetic humans confirming the pre-diabetic status of our pigs. Moreover, a novel isoform of TBC1D4 was detected by Western blotting using protein extracted from pancreas. The expression level of this novel isoform was further verified by qPCR in all tissues, showing the highest expression in the pancreas. PMID:26346769

  6. Gene Set Enrichment Analysis Unveils the Mechanism for the Phosphodiesterase 4B Control of Glucocorticoid Response in B-cell Lymphoma

    PubMed Central

    Kim, Sang-Woo; Rai, Deepak; Aguiar, Ricardo C.T.

    2015-01-01

    Purpose Resistance to glucocorticoid (GC) is a significant problem in the clinical management of lymphoid malignancies. Addressing this issue via a mechanistic understanding of relevant signaling pathways is more likely to yield positive outcomes. Experimental Design We used gene set enrichment analysis (GSEA), multiple genetic models of gain and loss of function in B-cell lymphoma cell lines, in vitro and in vivo, and primary patient samples to characterize a novel relationship between the cyclic AMP/phosphodiesterase 4B (cAMP/PDE4B), AKT/ mTOR activities, and GC responses. Results Starting from the GSEA, we found that overexpression of the PDE4B in diffuse large B-cell lymphoma (DLBCL) impinge on the same genes/pathways that are abnormally active in GC-resistant tumors. We used genetically modified cell lines to show that PDE4B modulates cAMP inhibitory activities toward the AKT/mTOR pathway and defines GC resistance in DLBCL. In agreement with these data, pharmacologic inhibition of PDE4 in a xenograft model of human lymphoma unleashed cAMP effects, inhibited AKT, and restored GC sensitivity. Finally, we used primary DLBCL samples to confirm the clinical relevance and biomarker potential of AKT/mTOR regulation by PDE4B. Conclusions Together, these data mechanistically elucidated how cAMP modulates GC responses in lymphocytes, defined AKT as the principal transducer of the growth inhibitory effects of cAMP in B cells, and allowed the formulation of genomics-guided clinical trials that test the ability of PDE4 inhibitors to restore GC sensitivity and improve the outcome of patients with B-cell malignancies. PMID:21742807

  7. The Pontin series of recombinant alien translocations in bread wheat: single translocations integrating combinations of Bdv2, Lr19 and Sr25 disease-resistance genes from Thinopyrum intermedium and Th. ponticum.

    PubMed

    Ayala-Navarrete, L I; Mechanicos, A A; Gibson, J M; Singh, D; Bariana, H S; Fletcher, J; Shorter, S; Larkin, Philip J

    2013-10-01

    Two bread wheat lines each with a translocation on chromosome 7DL from either Thinopyrum intermedium (TC5 and TC14) or Thinopyrum ponticum (T4m), were hybridized in a ph1b mutant background to enhance recombination between the two translocated chromosomal segments. The frequency of recombinants was high in lines derived from the larger and similar-sized translocations (TC5/T4m), but much lower when derived from different-sized translocations (TC14/T4m). Recombinant translocations contained combinations of resistance genes Bdv2, Lr19 and Sr25 conferring resistance to Barley yellow dwarf virus (BYDV), leaf rust and stem rust, respectively. Their genetic composition was identified using bioassays and molecular markers specific for the two progenitor Thinopyrum species. This set of 7DL Th. ponticum/intermedium recombinant translocations was termed the Pontin series. In addition to Thinopyrum markers, the size of the translocation was estimated with the aid of wheat markers mapped on each of the 7DL deletion bins. Bioassays for BYDV, leaf rust and stem rust were performed under greenhouse and field conditions. Once separated from ph1b background, the Pontin recombinant translocations were stable and showed normal inheritance in successive backcrosses. The reported Pontin translocations integrate important resistance genes in a single linkage block which will allow simultaneous selection of disease resistance. Combinations of Bdv2 + Lr19 or Lr19 + Sr25 in both long and short translocations, are available to date. The smaller Pontins, comprising only 20 % of the distal portion of 7DL, will be most attractive to breeders. PMID:23807636

  8. Nuclear translocation uncovers the amyloid peptide A?42 as a regulator of gene transcription.

    PubMed

    Barucker, Christian; Harmeier, Anja; Weiske, Joerg; Fauler, Beatrix; Albring, Kai Frederik; Prokop, Stefan; Hildebrand, Peter; Lurz, Rudi; Heppner, Frank L; Huber, Otmar; Multhaup, Gerhard

    2014-07-18

    Although soluble species of the amyloid-? peptide A?42 correlate with disease symptoms in Alzheimer disease, little is known about the biological activities of amyloid-? (A?). Here, we show that A? peptides varying in lengths from 38 to 43 amino acids are internalized by cultured neuroblastoma cells and can be found in the nucleus. By three independent methods, we demonstrate direct detection of nuclear A?42 as follows: (i) biochemical analysis of nuclear fractions; (ii) detection of biotin-labeled A? in living cells by confocal laser scanning microscopy; and (iii) transmission electron microscopy of A? in cultured cells, as well as brain tissue of wild-type and transgenic APPPS1 mice (overexpression of amyloid precursor protein and presenilin 1 with Swedish and L166P mutations, respectively). Also, this study details a novel role for A?42 in nuclear signaling, distinct from the amyloid precursor protein intracellular domain. Chromatin immunoprecipitation showed that A?42 specifically interacts as a repressor of gene transcription with LRP1 and KAI1 promoters. By quantitative RT-PCR, we confirmed that mRNA levels of the examined candidate genes were exclusively decreased by the potentially neurotoxic A?42 wild-type peptide. Shorter peptides (A?38 or A?40) and other longer peptides (nontoxic A?42 G33A substitution or A?43) did not affect mRNA levels. Overall, our data indicate that the nuclear translocation of A?42 impacts gene regulation, and deleterious effects of A?42 in Alzheimer disease pathogenesis may be influenced by altering the expression profiles of disease-modifying genes. PMID:24878959

  9. The Transcriptional Co-Repressor Myeloid Translocation Gene 16 Inhibits Glycolysis and Stimulates Mitochondrial Respiration

    PubMed Central

    Kumar, Parveen; Sharoyko, Vladimir V.; Spégel, Peter; Gullberg, Urban; Mulder, Hindrik; Olsson, Inge; Ajore, Ram

    2013-01-01

    The myeloid translocation gene 16 product MTG16 is found in multiple transcription factor–containing complexes as a regulator of gene expression implicated in development and tumorigenesis. A stable Tet-On system for doxycycline–dependent expression of MTG16 was established in B-lymphoblastoid Raji cells to unravel its molecular functions in transformed cells. A noticeable finding was that expression of certain genes involved in tumor cell metabolism including 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 and 4 (PFKFB3 and PFKFB4), and pyruvate dehydrogenase kinase isoenzyme 1 (PDK1) was rapidly diminished when MTG16 was expressed. Furthermore, hypoxia–stimulated production of PFKFB3, PFKFB4 and PDK1 was inhibited by MTG16 expression. The genes in question encode key regulators of glycolysis and its coupling to mitochondrial metabolism and are commonly found to be overexpressed in transformed cells. The MTG16 Nervy Homology Region 2 (NHR2) oligomerization domain and the NHR3 protein–protein interaction domain were required intact for inhibition of PFKFB3, PFKFB4 and PDK1 expression to occur. Expression of MTG16 reduced glycolytic metabolism while mitochondrial respiration and formation of reactive oxygen species increased. The metabolic changes were paralleled by increased phosphorylation of mitogen–activated protein kinases, reduced levels of amino acids and inhibition of proliferation with a decreased fraction of cells in S-phase. Overall, our findings show that MTG16 can serve as a brake on glycolysis, a stimulator of mitochondrial respiration and an inhibitor of cell proliferation. Hence, elevation of MTG16 might have anti–tumor effect. PMID:23840896

  10. Moderate-level gene amplification in methotrexate-resistant Chinese hamster ovary cells is accompanied by chromosomal translocations at or near the site of the amplified DHFR gene.

    PubMed Central

    Flintoff, W F; Livingston, E; Duff, C; Worton, R G

    1984-01-01

    In previous studies, we have described several classes of methotrexate-resistant Chinese hamster ovary cell lines. Although the RI class is resistant because of an altered target enzyme, dihydrofolate reductase, the RIII class derived from RI cells is somewhat more resistant because of a moderate amplification of the altered dhfr structural gene (Flintoff et al., Mol. Cell. Biol. 2:275-285, 1982). In one RIII line, a translocation between the short arm (p) of chromosome 2 and the long arm (q) of chromosome 5 was observed, and the amplified RIII gene complex was mapped to the p arm of the 2p-marker chromosome derived from the translocation (Worton et al., Mol. Cell. Biol. 1:330-335, 1981). We tested the hypothesis that chromosomal translocation is a general feature of RIII cells and that such translocation involves a site at or near the dhfr structural gene. Thus, we examined four independently derived RIII-type mutants and found that each had a moderate amplification of the dhfr gene sequences, and karyotype analysis revealed that each carried a translocation involving the 2p arm at or near band 2p25. That this chromosomal rearrangement involves a site near the dhfr locus was demonstrated by mapping the altered but unamplified structural gene coding for the RI phenotype to the short arm of an unaltered chromosome 2. This suggests that a highly specific rearrangement involving an exchange at or near the site of the unamplified gene is a necessary prerequisite for the amplification process. A model for gene amplification involving chromosomal rearrangements and sister chromatid exchange is described. Images PMID:6700586

  11. Molecular cloning and chromosomal mapping of bone marrow stromal cell surface gene, BST2, that may be involved in pre-B-cell growth

    SciTech Connect

    Ishikawa, Jun; Kaisho, Tsuneyasu; Tomizawa, Hitoshi

    1995-04-10

    Bone marrow stromal cells regulate B-cell growth and development through their surface molecules and cytokines. In this study, we generated a mAb, RS38, that recognized a novel human membrane protein, BST-2, expressed on bone marrow stromal cell lines and synovial cell lines. We cloned a cDNA encoding BST-2 from a rheumatoid arthritis-derived synovial cell line. BST-2 is a 30- to 36-kDa type II transmembrane protein, consisting of 180 amino acids. The BST-2 gene (HGMW-approved symbol BST2) is located on chromosome 19p13.2. BST-2 is expressed not only on certain bone marrow stromal cell lines but also on various normal tissues, although its expression pattern is different from that of another bone marrow stromal cell surface molecule, BST-1. BST-2 surface expression on fibroblast cell lines facilitated the stromal cell-dependent growth of a murine bone marrow-derived pre-B-cell line, DW34. The results suggest that BST-2 may be involved in pre-B-cell growth. 45 refs., 7 figs., 2 tabs.

  12. Immunoglobulin and T-cell receptor gene-gene rearrangement in pleural cavity-based T-cell rich B-cell lymphoma in an immunocompetent patient.

    PubMed

    Potti, Anil; Malik, Azhar Ali; Ganti, Apar Kishor; Koch, Michael; Leitch, John

    2002-01-01

    Body cavity-based lymphomas are fluid-based lymphomas that are not associated with a tumor mass or adenopathy which could explain the origin of the lymphomatous effusion. A distinct lymphoma that grows in the body cavity as a lymphomatous effusion in the absence of a tumor mass has been identified as a primary effusion lymphoma. This almost exclusively occurs in patients with acquired immunodeficiency syndrome (AIDS), who invariably have a history of Kaposi sarcoma. We report a rare case of a recurrent pleural effusion in an immunocompetent patient. There was no evidence of lymphadenopathy or an associated mass on computerized tomography of the chest, abdomen and pelvis. Serology for HIV, HHS-8, EBV and HTLV-1 were negative. Cytologic examination of the pleural fluid showed an elevated white cell count with 97% lymphocytes, mostly with T-cell markers. Bone marrow aspirate and biopsy were negative and bronchoscopy was unrevealing. Pleural biopsy was significant for >70% T-lymphocytes and some large atypical cells. Which had CD19, CD20 and weak bcl-2 positivity. Kappa and lambda light chains did not show distinct clonality. A preliminary diagnosis of T-cell rich B-cell lymphoma (TCRBCL) of the pleural cavity was made. The diagnosis was confirmed with DNA studies done on the pleural biopsy specimen using PCR and southern blot. Dual rearrangement of Ig heavy chain region and TCR-beta genes were identified. The patient responded to combination chemotherapy with cyclophosphamide, adriamycin, vincristine and prednisone. Our case is the first known case of pleural cavity-based TCRBCL and illustrates the role of gene rearrangement studies in such patients. PMID:11908729

  13. Frequency of copy number abnormalities in common genes associated with B-cell precursor acute lymphoblastic leukemia cytogenetic subtypes in Brazilian children.

    PubMed

    Conceição Barbosa, Thayana; Terra-Granado, Eugenia; Quezado Magalhães, Isis M; Neves, Gustavo Ribeiro; Gadelha, Andrea; Guedes Filho, Gilson Espinola; Souza, Marcelo Santos; Melaragno, Renato; Emerenciano, Mariana; Pombo-de-Oliveira, Maria S

    2015-10-01

    Copy number alterations (CNAs) in genes committed to B-cell precursors have been associated with poor survival in subgroups of patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). We investigated submicroscopic alterations in a series of 274 Brazilian children with BCP-ALL by multiplex ligation-dependent probe amplification and evaluated their correlation with clinical and laboratory features. The relevance of overlapping CNA abnormalities was also explored. Deletions/amplifications in at least one gene were identified in 83% of the total series. In children older than 2 years, there was a predominance of CNAs involving deletions in IKZF1, CDKN2A, and CDKN2B, whereas the pseudoautosomal region 1 (PAR1) had deletions that were found more frequently in infants (P?<0.05). Based on the cytogenetic subgroups, favorable cytogenetic subgroups showed more deletions than other subgroups that occurred simultaneously, specifically ETV6 deletions (P?<0.05). TCF3-PBX1 was frequently deleted in RB1, and an absence of deletions was observed in IKZF1 and genes localized to the PAR1 region. The results corroborate with previous genome-wide studies and aggregate new markers for risk stratification of BCP-ALL in Brazil. PMID:26277549

  14. Restricted isotype, distinct variable gene usage, and high rate of gp120-specificity of HIV-1 Envelope-specific B cells in colostrum compared to those in blood of HIV-1-infected, lactating African women

    PubMed Central

    Sacha, C.R.; Vandergrift, N.; Jeffries, T.L.; McGuire, E.; Fouda, G.G.; Liebl, B.; Marshall, D.J.; Gurley, T.C.; Stiegel, L.; Whitesides, J.F.; Friedman, J.; Badiabo, A.; Foulger, A.; Yates, N.L.; Tomaras, G.D.; Kepler, T.B.; Liao, H.X.; Haynes, B.F.; Moody, M.A.; Permar, S.R.

    2014-01-01

    A successful HIV-1 vaccine must elicit immune responses that impede mucosal virus transmission, though functional roles of protective HIV-1 Envelope (Env)-specific mucosal antibodies remain unclear. Colostrum is a rich source of readily accessible mucosal B cells that may help define the mucosal antibody response contributing to prevention of postnatal HIV-1 transmission. To examine the HIV-1 Env-specific colostrum B cell repertoire, single B cells were isolated from 17 chronically HIV-infected, lactating women, producing 51 blood and 39 colostrum HIV-1 Env-specific B cell antibodies. All HIV-1 Env-specific colostrum-derived antibodies were IgG1 isotype and had mean heavy chain complementarity-determining region 3 (CDR3) lengths and mutation frequencies similar to those isolated from blood. However, variable heavy chain (VH) gene subfamily 1~69 usage was higher among colostrum than blood HIV-1 Env-reactive antibodies (49% versus 20%, p = 0.006, Fisher’s exact test). Additionally, more HIV-1 Env-specific colostrum antibodies were gp120-specific than those isolated from blood (44% versus 16%, p = 0.005, Fisher’s exact test). One cross-compartment HIV-1 Env-specific clonal B cell lineage was identified. These unique characteristics of colostrum B cell antibodies suggest selective homing of HIV-1-specific IgG1-secreting memory B cells to the mammary gland and have implications for targeting mucosal B cell populations by vaccination. PMID:25100291

  15. 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

    PubMed Central

    Carlotti, Emanuela; Wrench, David; Rosignoli, Guglielmo; Marzec, Jacek; Sangaralingam, Ajanthah; Hazanov, Lena; Michaeli, Miri; Hallam, Simon; Chaplin, Tracy; Iqbal, Sameena; Calaminici, Maria; Young, Bryan; Mehr, Ramit; Campbell, Peter; Fitzgibbon, Jude; Gribben, John G.

    2015-01-01

    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. PMID:26325507

  16. Ectopic expression of homeobox gene NKX2-1 in diffuse large B-cell lymphoma is mediated by aberrant chromatin modifications.

    PubMed

    Nagel, Stefan; Ehrentraut, Stefan; Tomasch, Jürgen; Quentmeier, Hilmar; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G; MacLeod, Roderick A F

    2013-01-01

    Homeobox genes encode transcription factors ubiquitously involved in basic developmental processes, deregulation of which promotes cell transformation in multiple cancers including hematopoietic malignancies. In particular, NKL-family homeobox genes TLX1, TLX3 and NKX2-5 are ectopically activated by chromosomal rearrangements in T-cell neoplasias. Here, using transcriptional microarray profiling and RQ-PCR we identified ectopic expression of NKL-family member NKX2-1, in a diffuse large B-cell lymphoma (DLBCL) cell line SU-DHL-5. Moreover, in silico analysis demonstrated NKX2-1 overexpression in 5% of examined DLBCL patient samples. NKX2-1 is physiologically expressed in lung and thyroid tissues where it regulates differentiation. Chromosomal and genomic analyses excluded rearrangements at the NKX2-1 locus in SU-DHL-5, implying alternative activation. Comparative expression profiling implicated several candidate genes in NKX2-1 regulation, variously encoding transcription factors, chromatin modifiers and signaling components. Accordingly, siRNA-mediated knockdown and overexpression studies confirmed involvement of transcription factor HEY1, histone methyltransferase MLL and ubiquitinated histone H2B in NKX2-1 deregulation. Chromosomal aberrations targeting MLL at 11q23 and the histone gene cluster HIST1 at 6p22 which we observed in SU-DHL-5 may, therefore, represent fundamental mutations mediating an aberrant chromatin structure at NKX2-1. Taken together, we identified ectopic expression of NKX2-1 in DLBCL cells, representing the central player in an oncogenic regulative network compromising B-cell differentiation. Thus, our data extend the paradigm of NKL homeobox gene deregulation in lymphoid malignancies. PMID:23637834

  17. Control region translocation and a tRNA gene inversion in the mitogenome of Paraplagusia japonica (Pleuronectiformes: Cynoglossidae).

    PubMed

    Gong, Li; Shi, Wei; Wang, Zhong-Ming; Miao, Xian-Guang; Kong, Xiao-Yu

    2013-12-01

    Paraplagusia japonica (Cynoglossidae, Soleoidei) is characterized by a bilaterally asymmetrical and a series of fringes on the lips on the ocular side. Here we report for the first time the mitogenome of this tongue sole, which is 16,694 bp in length, and the gene order has been reorganized. The tRNA-Gln gene translocated from the light strand (L-strand) to the heavy strand (H-strand), accompanied by tRNA-Ile gene shuffling. In addition, the putative control region translocated downstream to the place between the ND1 and the tRNA-Gln genes, leaving a 26-bp trace fragment in the original position. Nevertheless, the rest gene order is identical to that of the typical fish. In addition, it is the first report of the rare ATT as an initiation codon for ND3, and the ATP6 (- 26) and ND5 (+26) are unusually shorter or longer than those in other flatfish. These data will provide useful information for better understanding the molecular mechanisms of gene reorganization in fish mitogenome. PMID:23544789

  18. 1,25-dihydroxyvitamin D{sub 3} impairs NF-{kappa}B activation in human naive B cells

    SciTech Connect

    Geldmeyer-Hilt, Kerstin; Heine, Guido; Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin ; Hartmann, Bjoern; Baumgrass, Ria; Radbruch, Andreas; Worm, Margitta

    2011-04-22

    Highlights: {yields} In naive B cells, VDR activation by calcitriol results in reduced NF-{kappa}B p105 and p50 protein expression. {yields} Ligating the VDR with calcitriol causes reduced nuclear translocation of NF-{kappa}B p65. {yields} Reduced nuclear amount of p65 after calcitriol incubation results in reduced binding of p65 on the p105 promoter. {yields} 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: 1{alpha},25-dihydroxyvitamin D{sub 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-{kappa}B p50 activation, which is essential for the class switch to IgE. Herein, we investigated by which mechanism calcitriol modulates NF-{kappa}B 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-{kappa}B activation by interference with NF-{kappa}B p65 and p105. Thus, the vitamin D receptor inhibits costimulatory signal transduction in naive B cells, namely by reducing CD40 signaling.

  19. Molecular evolution of a central region containing B cell epitopes in the gene encoding the p67 sporozoite antigen within a field population of Theileria parva.

    PubMed

    Obara, Isaiah; Ulrike, Seitzer; Musoke, Tony; Spooner, Paul R; Jabbar, Ahmed; Odongo, David; Kemp, Stephen; Silva, Joana C; Bishop, Richard P

    2015-05-01

    Protective immunity induced by the infective sporozoite stage of Theileria parva indicates a potential role for antibodies directed against conserved serologically reactive regions of the major sporozoite surface antigen p67 in vaccination to control the parasite. We have examined the allelic variation and determined the extent of B cell epitope polymorphism of the gene encoding p67 among field isolates originating from cattle exposed to infected ticks in the Marula area of the rift valley in central Kenya where the African cape buffalo (Syncerus caffer) and cattle co-graze. In the first of two closely juxtaposed epitope sequences in the central region of the p67 protein, an in-frame deletion of a seven-amino acid segment results in a truncation that was observed in parasites derived from cattle that co-grazed with buffalo. In contrast, the variation in the second epitope was primarily due to nonsynonymous substitutions, resulting in relatively low overall amino acid conservation in this segment of the protein. We also observed polymorphism in the region of the protein adjacent to the two defined epitopes, but this was not sufficient to provide statistically significant evidence for positive selection. The data indicates that B cell epitopes previously identified within the p67 gene are polymorphic within the Marula field isolates. Given the complete sequence identity of the p67 gene in all previously characterized T. parva isolates that are transmissible between cattle by ticks, the diversity observed in p67 from the Marula isolates in combination with the clinical reaction of the infected cattle is consistent with them originating from ticks that had acquired T. parva from buffalo. PMID:25673078

  20. Automated analysis of high-throughput B-cell sequencing data reveals a high frequency of novel immunoglobulin V gene segment alleles.

    PubMed

    Gadala-Maria, Daniel; Yaari, Gur; Uduman, Mohamed; Kleinstein, Steven H

    2015-02-24

    Individual variation in germline and expressed B-cell immunoglobulin (Ig) repertoires has been associated with aging, disease susceptibility, and differential response to infection and vaccination. Repertoire properties can now be studied at large-scale through next-generation sequencing of rearranged Ig genes. Accurate analysis of these repertoire-sequencing (Rep-Seq) data requires identifying the germline variable (V), diversity (D), and joining (J) gene segments used by each Ig sequence. Current V(D)J assignment methods work by aligning sequences to a database of known germline V(D)J segment alleles. However, existing databases are likely to be incomplete and novel polymorphisms are hard to differentiate from the frequent occurrence of somatic hypermutations in Ig sequences. Here we develop a Tool for Ig Genotype Elucidation via Rep-Seq (TIgGER). TIgGER analyzes mutation patterns in Rep-Seq data to identify novel V segment alleles, and also constructs a personalized germline database containing the specific set of alleles carried by a subject. This information is then used to improve the initial V segment assignments from existing tools, like IMGT/HighV-QUEST. The application of TIgGER to Rep-Seq data from seven subjects identified 11 novel V segment alleles, including at least one in every subject examined. These novel alleles constituted 13% of the total number of unique alleles in these subjects, and impacted 3% of V(D)J segment assignments. These results reinforce the highly polymorphic nature of human Ig V genes, and suggest that many novel alleles remain to be discovered. The integration of TIgGER into Rep-Seq processing pipelines will increase the accuracy of V segment assignments, thus improving B-cell repertoire analyses. PMID:25675496

  1. B-cell neoplasia associated gene with multiple splicing (BCMS): the candidate B-CLL gene on 13q14 comprises more than 560 kb covering all critical regions.

    PubMed

    Wolf, S; Mertens, D; Schaffner, C; Korz, C; Döhner, H; Stilgenbauer, S; Lichter, P

    2001-06-01

    Deletions in chromosomal band 13q14.3 occur in >50% of B-cell chronic lymphocytic leukemias (B-CLL) and mantle cell lymphoma, indicating the localization of a tumor suppressor gene involved in the pathomechanism of these diseases. Within a 400 kb recurrently deleted segment at least two minimally deleted subregions had been reported. For the two genes residing in the proximal subregion, initially named LEU1 and LEU2, a pathogenic role has not yet been established. We report here that LEU1 is only a small portion of a large gene, which spans all previously reported critical subregions including the distal subregion. This gene, designated B-cell neoplasia-associated gene with multiple splicing (BCMS), is composed of at least 50 exons spanning >or=560 kb of genomic DNA and is expressed in more than 20 RNA splicing variants. While tissue-specific expression of RNA variants was observed, there was no evidence for the expression of a variant specific for B-CLL. Sequence analysis of the RNA variants suggests that BCMS transcripts belong to the group of non-coding RNAs. The alignment of the gene with all critical subregions provides a strong argument for BCMS being the most likely candidate for the tumor suppressor gene in 13q14 involved in the leukemogenesis of B-CLL. Due to the limited understanding of functional RNAs, however, it remains difficult to prove the pathogenic role of BCMS. PMID:11406609

  2. GenomicScape: An Easy-to-Use Web Tool for Gene Expression Data Analysis. Application to Investigate the Molecular Events in the Differentiation of B Cells into Plasma Cells

    PubMed Central

    Kassambara, Alboukadel; Rème, Thierry; Jourdan, Michel; Fest, Thierry; Hose, Dirk; Tarte, Karin; Klein, Bernard

    2015-01-01

    DNA microarrays have considerably helped to improve the understanding of biological processes and diseases. Large amounts of publicly available microarray data are accumulating, but are poorly exploited due to a lack of easy-to-use bioinformatics resources. The aim of this study is to build a free and convenient data-mining web site (www.genomicscape.com). GenomicScape allows mining dataset from various microarray platforms, identifying genes differentially expressed between populations, clustering populations, visualizing expression profiles of large sets of genes, and exporting results and figures. We show how easily GenomicScape makes it possible to construct a molecular atlas of the B cell differentiation using publicly available transcriptome data of naïve B cells, centroblasts, centrocytes, memory B cells, preplasmablasts, plasmablasts, early plasma cells and bone marrow plasma cells. Genes overexpressed in each population and the pathways encoded by these genes are provided as well as how the populations cluster together. All the analyses, tables and figures can be easily done and exported using GenomicScape and this B cell to plasma cell atlas is freely available online. Beyond this B cell to plasma cell atlas, the molecular characteristics of any biological process can be easily and freely investigated by uploading the corresponding transcriptome files into GenomicScape. PMID:25633866

  3. Follicular lymphoma: too many reminders for a memory B cell

    PubMed Central

    Swaminathan, Srividya; Müschen, Markus

    2014-01-01

    Memory B cells are a dynamic subset of the mature B cell population that in some cases can reenter germinal centers (GCs) in response to iterative infections. Such a reactivation can lead to accumulation of genetic lesions in these cells, potentially from repetitive activation of the B cell mutator enzyme AID. Normal memory B cells do not survive repeated reentries into GCs. In this issue, Sungalee et al. demonstrate that memory B cells harboring the oncogenic BCL2:IGH translocation, which results in constitutive BCL2 expression, survive multiple GC entries upon repetitive immunization. Through these multiple GC reentries, the hallmark BCL2:IGH translocation enables AID-induced hypermutation and propagates clonal evolution toward malignant follicular lymphoma. PMID:25384212

  4. An additional segment at 1p36 derived from der(18)t(14;18) in patients with diffuse large B-cell lymphomas transformed from follicular lymphoma.

    PubMed

    Nomura, Kenichi; Kanda-Akano, Yumiko; Shimizu, Daisuke; Okuda, Takashi; Yoshida, Naohisa; Matsumoto, Yosuke; Nishida, Kazuhiro; Taki, Tomohiko; Yokota, Shohei; Horiike, Shigeo; Taniwaki, Masafumi

    2005-07-01

    The particular translocation in follicular lymphomas (FLs) is a t(14;18)(q32;q21), recombining the immunoglobulin heavy chain (IgH) gene on chromosome 14 with the B-cell leukemia/lymphoma 2 (BCL2) gene on chromosome 18. Some low-grade FLs are aggressively transformed into diffuse large B-cell lymphomas, presumably by acquisition of secondary chromosomal changes, including chromosomal band 1p36. A common example is add(1)(p36). Because it is difficult to identify the origin of add(1)(p36) even on high-resolution G-banding analysis, we used spectral karyotyping (SKY) and double-color fluorescence in situ hybridization (DC-FISH) to define the t(14;18) and the extra band at 1p36 in two cases of diffuse large B-cell lymphoma (DLBCL). SKY revealed that the extra chromosomal segment on 1p36 was derived from chromosome 18. DC-FISH defined BCL2/IgH fusion signals at 1p36 in addition to t(14;18), suggesting that BCL2/IgH fusion at 1p36 was an evolutionary alteration following the primary BCL2/IgH translocation on der(18) in both cases. Our results indicate that IgH alleles, implicated in chromosomal rearrangement, may themselves frequently be targets for secondary translocations, suggesting that multiple IgH translocations and insertions are associated with the progression of FL. PMID:15700138

  5. Clonal Progression during the T Cell-Dependent B Cell Antibody Response Depends on the Immunoglobulin DH Gene Segment Repertoire

    PubMed Central

    Trad, Ahmad; Tanasa, Radu Iulian; Lange, Hans; Zemlin, Michael; Schroeder, Harry W.; Lemke, Hilmar

    2014-01-01

    The diversity of the third complementarity determining region of the IgH chain is constrained by natural selection of immunoglobulin diversity (DH) sequence. To test the functional significance of this constraint in the context of thymus-dependent (TD) immune responses, we immunized BALB/c mice with WT or altered DH sequence with 2-phenyloxazolone-coupled chicken serum albumin (phOx-CSA). We chose this antigen because studies of the humoral immune response to the hapten phOx were instrumental in the development of the current theoretical framework on which our understanding of the forces driving TD responses is based. To allow direct comparison, we used the classic approach of generating monoclonal Ab (mAb) from various stages of the immune response to phOx to assess the effect of changing the sequence of the DH on clonal expansion, class switching, and affinity maturation, which are hallmarks of TD responses. Compared to WT, TD-induced humoral IgM as well as IgG antibody production in the D-altered ?D-D?FS and ?D-iD strains were significantly reduced. An increased prevalence of IgM-producing hybridomas from late primary, secondary, and tertiary memory responses suggested either impaired class switch recombination (CSR) or impaired clonal expansion of class switched B cells with phOx reactivity. Neither of the D-altered strains demonstrated the restriction in the VH/VL repertoire, the elimination of VH1 family-encoded antibodies, the focusing of the distribution of CDR-H3 lengths, or the selection for the normally dominant Ox1 clonotype, which all are hallmarks of the anti-phOx response in WT mice. These changes in clonal selection and expansion, as well as CSR indicate that the genetic constitution of the DH locus, which has been selected by evolution, can strongly influence the functional outcome of a TD humoral response. PMID:25157256

  6. Expression of ribosomal RNA genes in lines of barley with a standard karyotype and with a translocated nucleolar organizer

    SciTech Connect

    Karag'ozov, L.K.; Ananiev, E.D.; Mateeva, Z.E.; Khadzhiolov, A.A.

    1986-10-01

    The authors have investigated the rRNA synthesis and the sensitivity of rRNA genes to the action of DNAase I in developing embryos of two forms of barley. The Frigga variety has a standard karyotype and the T/sub 506/ line is characterized by translocation of the nucleolar organizer, which leads to a reduction in the number of nucleoli observed in the telophase. The results of the investigation of rRNA synthesis in vivo and of the activity of RNA polymerase I in isolated nuclei revealed the absence of differences between the two barley forms. They have established that the genes of ribosomal RNAs possess greater sensitivity to digestion by DNAase the authors compared to that of the total nuclear DNA. They conclude that the translocation of one of the nucleolar organizers causes a delay in the appearance of its activity during the telophase, this not changing the expression of the rRNA genes in the subsequent stages of cell development.

  7. Human TLR10 is a functional receptor, expressed by B cells and plasmacytoid dendritic cells, which activates gene transcription through MyD88.

    PubMed

    Hasan, Uzma; Chaffois, Claire; Gaillard, Claude; Saulnier, Virginie; Merck, Estelle; Tancredi, Sandra; Guiet, Chantal; Brière, Francine; Vlach, Jaromir; Lebecque, Serge; Trinchieri, Giorgio; Bates, Elizabeth E M

    2005-03-01

    Human TLR10 is an orphan member of the TLR family. Genomic studies indicate that TLR10 is in a locus that also contains TLR1 and TLR6, two receptors known to function as coreceptors for TLR2. We have shown that TLR10 was not only able to homodimerize but also heterodimerized with TLRs 1 and 2. In addition, unlike TLR1 and TLR6, TLR10 was expressed in a highly restricted fashion as a highly N-glycosylated protein, which we detected in B cell lines, B cells from peripheral blood, and plasmacytoid dendritic cells from tonsil. We were also able to detect TLR10 in a CD1a(+) DC subset derived from CD34(+) progenitor cells which resemble Langerhans cells in the epidermis. Although we were unable to identify a specific ligand for TLR10, by using a recombinant CD4TLR10 molecule we also demonstrated that TLR10 directly associates with MyD88, the common Toll IL-1 receptor domain adapter. Additionally, we have characterized regions in the Toll IL-1 receptor domain of TLR10 that are essential in the activation of promoters from certain inflammatory cytokines. Even though TLR10 expression has not been detected in mice, we have identified a partial genomic sequence of the TLR10 gene that was present but nonfunctional and disrupted by a retroviral insertion in all mouse strains tested. However, a complete TLR10 sequence could be detected in the rat genome, indicating that a functional copy may be preserved in this species. PMID:15728506

  8. Reciprocal translocations

    SciTech Connect

    1993-12-31

    Chapter 26, describes reciprocal translocations of chromosomes: their occurrence, breakpoints, and multiple rearrangements. In addition, phenotypes of balanced and unbalanced translocation carriers and fetal death are discussed. Examples of translocation families are given. Meiosis and genetic risk in translocation carriers is presented. Finally, sperm chromosomes in meiotic segregation analysis is mentioned. 39 refs., 3 figs., 1 tab.

  9. Transcriptional expression analysis of genes involved in regulation of calcium translocation and storage in finger millet (Eleusine coracana L. Gartn.).

    PubMed

    Mirza, Neelofar; Taj, Gohar; Arora, Sandeep; Kumar, Anil

    2014-10-25

    Finger millet (Eleusine coracana) variably accumulates calcium in different tissues, due to differential expression of genes involved in uptake, translocation and accumulation of calcium. Ca(2+)/H(+) antiporter (CAX1), two pore channel (TPC1), CaM-stimulated type IIB Ca(2+) ATPase and two CaM dependent protein kinase (CaMK1 and 2) homologs were studied in finger millet. Two genotypes GP-45 and GP-1 (high and low calcium accumulating, respectively) were used to understand the role of these genes in differential calcium accumulation. For most of the genes higher expression was found in the high calcium accumulating genotype. CAX1 was strongly expressed in the late stages of spike development and could be responsible for accumulating high concentrations of calcium in seeds. TPC1 and Ca(2+) ATPase homologs recorded strong expression in the root, stem and developing spike and signify their role in calcium uptake and translocation, respectively. Calmodulin showed strong expression and a similar expression pattern to the type IIB ATPase in the developing spike only and indicating developing spike or even seed specific isoform of CaM affecting the activity of downstream target of calcium transportation. Interestingly, CaMK1 and CaMK2 had expression patterns similar to ATPase and TPC1 in various tissues raising a possibility of their respective regulation via CaM kinase. Expression pattern of 14-3-3 gene was observed to be similar to CAX1 gene in leaf and developing spike inferring a surprising possibility of CAX1 regulation through 14-3-3 protein. Our results provide a molecular insight for explaining the mechanism of calcium accumulation in finger millet. PMID:25101868

  10. A Constitutional Translocation t(1;17)(p36.2;q11.2) in a Neuroblastoma Patient Disrupts the Human NBPF1 and ACCN1 Genes

    PubMed Central

    Staes, Katrien; Vandesompele, Jo; Laureys, Geneviève; De Smet, Els; Berx, Geert; Speleman, Frank; van Roy, Frans

    2008-01-01

    The human 1p36 region is deleted in many different types of tumors, and so it probably harbors one or more tumor suppressor genes. In a Belgian neuroblastoma patient, a constitutional balanced translocation t(1;17)(p36.2;q11.2) may have led to the development of the tumor by disrupting or activating a gene. Here, we report the cloning of both translocation breakpoints and the identification of a novel gene that is disrupted by this translocation. This gene, named NBPF1 for Neuroblastoma BreakPoint Family member 1, belongs to a recently described gene family encoding highly similar proteins, the functions of which are unknown. The translocation truncates NBPF1 and gives rise to two chimeric transcripts of NBPF1 sequences fused to sequences derived from chromosome 17. On chromosome 17, the translocation disrupts one of the isoforms of ACCN1, a potential glioma tumor suppressor gene. Expression of the NBPF family in neuroblastoma cell lines is highly variable, but it is decreased in cell lines that have a deletion of chromosome 1p. More importantly, expression profiling of the NBPF1 gene showed that its expression is significantly lower in cell lines with heterozygous NBPF1 loss than in cell lines with a normal 1p chromosome. Meta-analysis of the expression of NBPF and ACCN1 in neuroblastoma tumors indicates a role for the NBPF genes and for ACCN1 in tumor aggressiveness. Additionally, DLD1 cells with inducible NBPF1 expression showed a marked decrease of clonal growth in a soft agar assay. The disruption of both NBPF1 and ACCN1 genes in this neuroblastoma patient indicates that these genes might suppress development of neuroblastoma and possibly other tumor types. PMID:18493581

  11. Clinical features, tumor biology, and prognosis associated with MYC rearrangement and Myc overexpression in diffuse large B-cell lymphoma patients treated with rituximab-CHOP.

    PubMed

    Xu-Monette, Zijun Y; Dabaja, Bouthaina S; Wang, Xiaoxiao; Tu, Meifeng; Manyam, Ganiraju C; Tzankov, Alexander; Xia, Yi; Zhang, Li; Sun, Ruifang; Visco, Carlo; Dybkaer, Karen; Yin, Lihui; Chiu, April; Orazi, Attilio; Zu, Youli; Bhagat, Govind; Richards, Kristy L; Hsi, Eric D; Choi, William Wl; van Krieken, J Han; Huh, Jooryung; Ponzoni, Maurilio; Ferreri, Andrés Jm; Møller, Michael B; Parsons, Ben M; Zhao, Xiaoying; Winter, Jane N; Piris, Miguel A; McDonnell, Timothy J; Miranda, Roberto N; Li, Yong; Medeiros, L Jeffrey; Young, Ken H

    2015-12-01

    MYC dysregulation, including MYC gene rearrangement and Myc protein overexpression, is of increasing clinical importance in diffuse large B-cell lymphoma (DLBCL). However, the roles of MYC and the relative importance of rearrangement vs overexpression remain to be refined. Gaining knowledge about the tumor biology associated with MYC dysregulation is important to understand the roles of MYC and MYC-associated biology in lymphomagenesis. In this study, we determined MYC rearrangement status (n=344) and Myc expression (n=535) in a well-characterized DLBCL cohort, individually assessed the clinical and pathobiological features of patients with MYC rearrangement and Myc protein overexpression, and analyzed the prognosis and gene expression profiling signatures associated with these MYC abnormalities in germinal center B-cell-like and activated B-cell-like DLBCL. Our results showed that the prognostic importance of MYC rearrangement vs Myc overexpression is significantly different in germinal center B-cell-like vs activated B-cell-like DLBCL. In germinal center B-cell-like DLBCL, MYC-rearranged germinal center B-cell-like DLBCL patients with Myc overexpression significantly contributed to the clinical, biological, and prognostic characteristics of the overall Myc-overexpressing germinal center B-cell-like DLBCL group. In contrast, in activated B-cell-like DLBCL, the occurrence, clinical and biological features, and prognosis of Myc overexpression were independent of MYC rearrangement. High Myc levels and Myc-independent mechanisms, either tumor cell intrinsic or related to tumor microenvironment, conferred significantly worse survival to MYC-rearranged germinal center B-cell-like DLBCL patients, even among Myc(high)Bcl-2(high) DLBCL patients. This study provides new insight into the tumor biology and prognostic effects associated with MYC dysregulation and suggest that detection of both MYC translocations and evaluation of Myc and Bcl-2 expression is necessary to predict the prognosis of DLBCL patients. PMID:26541272

  12. QuantiGene Plex Represents a Promising Diagnostic Tool for Cell-of-Origin Subtyping of Diffuse Large B-Cell Lymphoma.

    PubMed

    Hall, John S; Usher, Suzanne; Byers, Richard J; Higgins, Rebekah C; Memon, Danish; Radford, John A; Linton, Kim M

    2015-07-01

    Emerging therapies targeting the molecularly distinct GCB and non-GCB/ABC subtypes of diffuse large B-cell lymphoma (DLBCL) have created the need to develop an accurate subtyping assay for routine use. We investigated the potential of QuantiGene Plex (QGP)-branched DNA signal amplification assay-for DLBCL subtyping. We performed in silico analysis of public DLBCL datasets to develop and validate a naïve Bayes classifier, and migrated the resulting 21-gene classifier to QGP and real-time quantitative PCR (qPCR) assays. Forty DLBCL formalin-fixed, paraffin-embedded tumors of known subtype (20 per subtype by gene expression profiling of paired fresh-frozen tissues) were reclassified, and results for QGP (on 38/40 for 21/21 targets) and qPCR (on 40/40 samples for 19/21 targets) compared for recapitulation of microarray data and classification accuracy. The 21-gene bayesian classifier achieved mean area under the curve values >0.9 on independent validation. QGP showed a higher correlation with microarray data (mean R(2) = 0.66 ± 0.05 versus 0.34 ± 0.07; P < 0.0001) and classification accuracy (92.1% versus 78.9%). The proportion of validated targets was also higher for QGP (85.7% versus 47.4%). The QGP protocol was rapid and simple to perform, at a cost similar to qPCR. These promising preliminary results strongly support ongoing work to develop a QGP companion diagnostic assay for DLBCL subtyping. PMID:25982535

  13. Cloning of the anhidrotic ectodermal dysplasia gene: Identification of cDNAs associated with CpG islands mapped near translocation breakpoint in two female patients

    SciTech Connect

    Srivastava, A.K.; Schlessinger, D.; Kere, J.

    1994-09-01

    The gene for the X chromosomal developmental disorder anhidrotic ectodermal dysplasia (EDA) has been mapped to Xq12-q13 by linkage analysis and is expressed in a few females with chromosomal translocations involving band Xq12-q13. A yeast artificial chromosome (YAC) contig (2.0 Mb) spanning two translocation breakpoints has been assembled by sequence-tagged site (STS)-based chromosomal walking. The two translocation breakpoints (X:autosome translocations from the affected female patients) have been mapped less than 60 kb apart within a YAC contig. Unique probes and intragenic STSs (mapped between the two translocations) have been developed and a somatic cell hybrid carrying the translocated X chromosome from the AK patient has been analyzed by isolating unique probes that span the breakpoint. Several STSs made from intragenic sequences have been found to be conserved in mouse, hamster and monkey, but we have detected no mRNAs in a number of tissues tested. However, a probe and STS developed from the DNA spanning the AK breakpoint is conserved in mouse, hamster and monkey, and we have detected expressed sequences in skin cells and cDNA libraries. In addition, unique sequences have been obtained from two CpG islands in the region that maps proximal to the breakpoints. cDNAs containing these sequences are being studied as candidates for the gene affected in the etiology of EDA.

  14. Analysis of Host Gene Expression Changes Reveals Distinct Roles for the Cytoplasmic Domain of the Epstein-Barr Virus Receptor/CD21 in B-Cell Maturation, Activation, and Initiation of Virus Infection

    PubMed Central

    Arredouani, Mohamed S.; Bhasin, Manoj K.; Sage, David R.; Dunn, Laura K.; Gill, Michael B.; Agnani, Deep; Libermann, Towia A.

    2014-01-01

    ABSTRACT Epstein-Barr virus (EBV) attachment to human CD21 on the B-cell surface initiates infection. Whether CD21 is a simple tether or conveys vital information to the cell interior for production of host factors that promote infection of primary B cells is controversial, as the cytoplasmic fragment of CD21 is short, though highly conserved. The ubiquity of CD21 on normal B cells, the diversity of this population, and the well-known resistance of primary B cells to gene transfer technologies have all impeded resolution of this question. To uncover the role(s) of the CD21 cytoplasmic domain during infection initiation, the full-length receptor (CD21 = CR), a mutant lacking the entire cytoplasmic tail (CT), and a control vector (NEO) were stably expressed in two pre-B-cell lines that lack endogenous receptor. Genome-wide transcriptional analysis demonstrated that stable CD21 surface expression alone (either CR or CT) produced multiple independent changes in gene expression, though both dramatically decreased class I melanoma-associated antigen (MAGE) family RNAs and upregulated genes associated with B-cell differentiation (e.g., C2TA, HLA-II, IL21R, MIC2, CD48, and PTPRCAP/CD45-associated protein). Temporal analysis spanning 72 h revealed that not only CR- but also CT-expressing lines initiated latency. In spite of this, the number and spectrum of transcripts altered in CR- compared with CT-bearing lines at 1 h after infection further diverged. Differential modulation of immediate early cellular transcripts (e.g., c-Jun and multiple histones), both novel and previously linked to CD21-initiated signaling, as well as distinct results from pathway analyses support a separate role for the cytoplasmic domain in initiation of intracellular signals. IMPORTANCE Membrane proteins that mediate virus attachment tether virus particles to the cell surface, initiating infection. In addition, upon virus interaction such proteins may transmit signals to the interior of the cell that support subsequent steps in the infection process. Here we show that expression of the Epstein-Barr virus B-cell attachment receptor, CD21, in B cells that lack this receptor results in significant changes in gene expression, both before and rapidly following EBV-CD21 interaction. These changes translate into major signaling pathway alterations that are predicted to support stable infection. PMID:24600013

  15. The Flavones Apigenin and Luteolin Induce FOXO1 Translocation but Inhibit Gluconeogenic and Lipogenic Gene Expression in Human Cells

    PubMed Central

    Bumke-Vogt, Christiane; Osterhoff, Martin A.; Borchert, Andrea; Guzman-Perez, Valentina; Sarem, Zeinab; Birkenfeld, Andreas L.; Bähr, Volker; Pfeiffer, Andreas F. H.

    2014-01-01

    The flavones apigenin (4?,5,7,-trihydroxyflavone) and luteolin (3?,4?,5,7,-tetrahydroxyflavone) are plant secondary metabolites with antioxidant, antiinflammatory, and anticancer activities. We evaluated their impact on cell signaling pathways related to insulin-resistance and type 2 diabetes. Apigenin and luteolin were identified in our U-2 OS (human osteosarcoma) cell screening assay for micronutrients triggering rapid intracellular translocation of the forkhead box transcription factor O1 (FOXO1), an important mediator of insulin signal transduction. Insulin reversed the translocation of FOXO1 as shown by live cell imaging. The impact on the expression of target genes was evaluated in HepG2 (human hepatoma) cells. The mRNA-expression of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pc), the lipogenic enzymes fatty-acid synthase (FASN) and acetyl-CoA-carboxylase (ACC) were down-regulated by both flavones with smaller effective dosages of apigenin than for luteolin. PKB/AKT-, PRAS40-, p70S6K-, and S6-phosphorylation was reduced by apigenin and luteolin but not that of the insulin-like growth factor receptor IGF-1R by apigenin indicating a direct inhibition of the PKB/AKT-signaling pathway distal to the IGF-1 receptor. N-acetyl-L-cysteine did not prevent FOXO1 nuclear translocation induced by apigenin and luteolin, suggesting that these flavones do not act via oxidative stress. The roles of FOXO1, FOXO3a, AKT, sirtuin1 (SIRT1), and nuclear factor (erythroid-derived2)-like2 (NRF2), investigated by siRNA knockdown, showed differential patterns of signal pathways involved and a role of NRF2 in the inhibition of gluconeogenic enzyme expression. We conclude that these flavones show an antidiabetic potential due to reduction of gluconeogenic and lipogenic capacity despite inhibition of the PKB/AKT pathway which justifies detailed investigation in vivo. PMID:25136826

  16. TALEN-Induced Translocations in Human Cells.

    PubMed

    Piganeau, Marion; Renouf, Benjamin; Ghezraoui, Hind; Brunet, Erika

    2016-01-01

    Induction of chromosomal translocations in human cells is of a great interest to study tumorigenesis and genome instability. Here, we explain in detail a method to induce translocations using the transcription activator-like effector nucleases (TALENs). We describe how to detect translocation formation by PCR, calculate translocation frequency by 96-well PCR screen, and analyze breakpoint junctions. When inducing cancer translocations, it is also possible to detect the fusion gene by FISH analysis or western blot. PMID:26443217

  17. A recurrent 11q aberration pattern characterizes a subset of MYC-negative high-grade B-cell lymphomas resembling Burkitt lymphoma

    PubMed Central

    Martin-Guerrero, Idoia; Wagener, Rabea; Kreuz, Markus; Kohler, Christian W.; Richter, Julia; Pienkowska-Grela, Barbara; Adam, Patrick; Burkhardt, Birgit; Claviez, Alexander; Damm-Welk, Christine; Drexler, Hans G.; Hummel, Michael; Jaffe, Elaine S.; Küppers, Ralf; Lefebvre, Christine; Lisfeld, Jasmin; Löffler, Markus; Macleod, Roderick A. F.; Nagel, Inga; Oschlies, Ilske; Rosolowski, Maciej; Russell, Robert B.; Rymkiewicz, Grzegorz; Schindler, Detlev; Schlesner, Matthias; Scholtysik, René; Schwaenen, Carsten; Spang, Rainer; Szczepanowski, Monika; Trümper, Lorenz; Vater, Inga; Wessendorf, Swen; Klapper, Wolfram; Siebert, Reiner

    2014-01-01

    The genetic hallmark of Burkitt lymphoma (BL) is the t(8;14)(q24;q32) and its variants leading to activation of the MYC oncogene. It is a matter of debate whether true BL without MYC translocation exists. Here, we identified 59 lymphomas concordantly called BL by 2 gene expression classifiers among 753 B-cell lymphomas. Only 2 (3%) of these 59 molecular BL lacked a MYC translocation, which both shared a peculiar pattern of chromosome 11q aberration characterized by interstitial gains including 11q23.2-q23.3 and telomeric losses of 11q24.1-qter. We extended our analysis to 17 MYC-negative high-grade B-cell lymphomas with a similar 11q aberration and showed this aberration to be recurrently associated with morphologic and clinical features of BL. The minimal region of gain was defined by high-level amplifications in 11q23.3 and associated with overexpression of genes including PAFAH1B2 on a transcriptional and protein level. The recurrent region of loss contained a focal homozygous deletion in 11q24.2-q24.3 including the ETS1 gene, which was shown to be mutated in 4 of 16 investigated cases. These findings indicate the existence of a molecularly distinct subset of B-cell lymphomas reminiscent of BL, which is characterized by deregulation of genes in 11q. PMID:24398325

  18. The location and translocation of ndh genes of chloroplast origin in the Orchidaceae family

    PubMed Central

    Lin, Choun-Sea; Chen, Jeremy J. W.; Huang, Yao-Ting; Chan, Ming-Tsair; Daniell, Henry; Chang, Wan-Jung; Hsu, Chen-Tran; Liao, De-Chih; Wu, Fu-Huei; Lin, Sheng-Yi; Liao, Chen-Fu; Deyholos, Michael K.; Wong, Gane Ka-Shu; Albert, Victor A.; Chou, Ming-Lun; Chen, Chun-Yi; Shih, Ming-Che

    2015-01-01

    The NAD(P)H dehydrogenase complex is encoded by 11 ndh genes in plant chloroplast (cp) genomes. However, ndh genes are truncated or deleted in some autotrophic Epidendroideae orchid cp genomes. To determine the evolutionary timing of the gene deletions and the genomic locations of the various ndh genes in orchids, the cp genomes of Vanilla planifolia, Paphiopedilum armeniacum, Paphiopedilum niveum, Cypripedium formosanum, Habenaria longidenticulata, Goodyera fumata and Masdevallia picturata were sequenced; these genomes represent Vanilloideae, Cypripedioideae, Orchidoideae and Epidendroideae subfamilies. Four orchid cp genome sequences were found to contain a complete set of ndh genes. In other genomes, ndh deletions did not correlate to known taxonomic or evolutionary relationships and deletions occurred independently after the orchid family split into different subfamilies. In orchids lacking cp encoded ndh genes, non cp localized ndh sequences were identified. In Erycina pusilla, at least 10 truncated ndh gene fragments were found transferred to the mitochondrial (mt) genome. The phenomenon of orchid ndh transfer to the mt genome existed in ndh-deleted orchids and also in ndh containing species. PMID:25761566

  19. The location and translocation of ndh genes of chloroplast origin in the Orchidaceae family.

    PubMed

    Lin, Choun-Sea; Chen, Jeremy J W; Huang, Yao-Ting; Chan, Ming-Tsair; Daniell, Henry; Chang, Wan-Jung; Hsu, Chen-Tran; Liao, De-Chih; Wu, Fu-Huei; Lin, Sheng-Yi; Liao, Chen-Fu; Deyholos, Michael K; Wong, Gane Ka-Shu; Albert, Victor A; Chou, Ming-Lun; Chen, Chun-Yi; Shih, Ming-Che

    2015-01-01

    The NAD(P)H dehydrogenase complex is encoded by 11 ndh genes in plant chloroplast (cp) genomes. However, ndh genes are truncated or deleted in some autotrophic Epidendroideae orchid cp genomes. To determine the evolutionary timing of the gene deletions and the genomic locations of the various ndh genes in orchids, the cp genomes of Vanilla planifolia, Paphiopedilum armeniacum, Paphiopedilum niveum, Cypripedium formosanum, Habenaria longidenticulata, Goodyera fumata and Masdevallia picturata were sequenced; these genomes represent Vanilloideae, Cypripedioideae, Orchidoideae and Epidendroideae subfamilies. Four orchid cp genome sequences were found to contain a complete set of ndh genes. In other genomes, ndh deletions did not correlate to known taxonomic or evolutionary relationships and deletions occurred independently after the orchid family split into different subfamilies. In orchids lacking cp encoded ndh genes, non cp localized ndh sequences were identified. In Erycina pusilla, at least 10 truncated ndh gene fragments were found transferred to the mitochondrial (mt) genome. The phenomenon of orchid ndh transfer to the mt genome existed in ndh-deleted orchids and also in ndh containing species. PMID:25761566

  20. Arbuscular mycorrhiza affects nickel translocation and expression of ABC transporter and metallothionein genes in Festuca arundinacea.

    PubMed

    Shabani, Leila; Sabzalian, Mohammad R; Mostafavi Pour, Sodabeh

    2016-01-01

    Mycorrhizal fungi are key microorganisms for enhancing phytoremediation of soils contaminated with heavy metals. In this study, the effects of the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae (=Glomus mosseae) on physiological and molecular mechanisms involved in the nickel (Ni) tolerance of tall fescue (Festuca arundinacea?=?Schedonorus arundinaceus) were investigated. Nickel addition had a pronounced negative effect on tall fescue growth and photosynthetic pigment contents, as well as on AMF colonization. Phosphorus content increased markedly in mycorrhizal plants (M) compared to non-inoculated (NM) ones. However, no significant difference was observed in root carbohydrate content between AMF-inoculated and non-inoculated plants. For both M and NM plants, Ni concentrations in shoots and roots increased according to the addition of the metal into soil, but inoculation with F. mosseae led to significantly lower Ni translocation from roots to the aboveground parts compared to non-inoculated plants. ABC transporter and metallothionein transcripts accumulated to considerably higher levels in tall fescue plants colonized by F. mosseae than in the corresponding non-mycorrhizal plants. These results highlight the importance of mycorrhizal colonization in alleviating Ni-induced stress by reducing Ni transport from roots to shoots of tall fescue plants. PMID:26041568

  1. Lymphomagenic CARD11/BCL10/MALT1 signaling drives malignant B-cell proliferation via cooperative NF-?B and JNK activation.

    PubMed

    Knies, Nathalie; Alankus, Begüm; Weilemann, Andre; Tzankov, Alexandar; Brunner, Kristina; Ruff, Tanja; Kremer, Marcus; Keller, Ulrich B; Lenz, Georg; Ruland, Jürgen

    2015-12-29

    The aggressive activated B cell-like subtype of diffuse large B-cell lymphoma is characterized by aberrant B-cell receptor (BCR) signaling and constitutive nuclear factor kappa-B (NF-?B) activation, which is required for tumor cell survival. BCR-induced NF-?B activation requires caspase recruitment domain-containing protein 11 (CARD11), and CARD11 gain-of-function mutations are recurrently detected in human diffuse large B-cell lymphoma (DLBCL). To investigate the consequences of dysregulated CARD11 signaling in vivo, we generated mice that conditionally express the human DLBCL-derived CARD11(L225LI) mutant. Surprisingly, CARD11(L225LI) was sufficient to trigger aggressive B-cell lymphoproliferation, leading to early postnatal lethality. CARD11(L225LI) constitutively associated with B-cell CLL/lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) to simultaneously activate the NF-?B and c-Jun N-terminal kinase (JNK) signaling cascades. Genetic deficiencies of either BCL10 or MALT1 completely rescued the phenotype, and pharmacological inhibition of JNK was, similar to NF-?B blockage, toxic to autonomously proliferating CARD11(L225LI)-expressing B cells. Moreover, constitutive JNK activity was observed in primary human activated B cell-like (ABC)-DLBCL specimens, and human ABC-DLBCL cells were also sensitive to JNK inhibitors. Thus, our results demonstrate that enforced activation of CARD11/BCL10/MALT1 signaling is sufficient to drive transformed B-cell expansion in vivo and identify the JNK pathway as a therapeutic target for ABC-DLBCL. PMID:26668357

  2. LMO2 at 25 years: a paradigm of chromosomal translocation proteins

    PubMed Central

    Chambers, Jennifer; Rabbitts, Terence H.

    2015-01-01

    LMO2 was first discovered through proximity to frequently occurring chromosomal translocations in T cell acute lymphoblastic leukaemia (T-ALL). Subsequent studies on its role in tumours and in normal settings have highlighted LMO2 as an archetypical chromosomal translocation oncogene, activated by association with antigen receptor gene loci and a paradigm for translocation gene activation in T-ALL. The normal function of LMO2 in haematopoietic cell fate and angiogenesis suggests it is a master gene regulator exerting a dysfunctional control on differentiation following chromosomal translocations. Its importance in T cell neoplasia has been further emphasized by the recurrent findings of interstitial deletions of chromosome 11 near LMO2 and of LMO2 as a target of retroviral insertion gene activation during gene therapy trials for X chromosome-linked severe combined immuno-deficiency syndrome, both types of event leading to similar T cell leukaemia. The discovery of LMO2 in some B cell neoplasias and in some epithelial cancers suggests a more ubiquitous function as an oncogenic protein, and that the current development of novel inhibitors will be of great value in future cancer treatment. Further, the role of LMO2 in angiogenesis and in haematopoietic stem cells (HSCs) bodes well for targeting LMO2 in angiogenic disorders and in generating autologous induced HSCs for application in various clinical indications. PMID:26108219

  3. The DIRC1 gene at chromosome 2q33 spans a familial RCC-associated t(2;3)(q33;q21) chromosome translocation.

    PubMed

    Druck, T; Podolski, J; Byrski, T; Wyrwicz, L; Zajaczek, S; Kata, G; Borowka, A; Lubinski, J; Huebner, K

    2001-01-01

    A reciprocal, balanced, constitutional chromosome translocation, t(2;3)(q33;q21), which is associated with familial clear cell renal cancer, has been described and the genomic regions surrounding the 2q and 3q breakpoints have been characterized. Based on the genomic map of the 2q break, EST AI468595 was positioned near the 2q33 translocation and the full-length gene and cDNA were isolated. This 57-kb gene, designated the DIRC1 gene, was disrupted between exons 1 and 2 by the familial translocation. The 1.5-kb mRNA encodes an 11-kDa predicted protein of 104 amino acids. Low-level expression of DIRC1 was detected by reverse transcriptase-polymerase chain reaction amplification in adult placenta, testis, ovary, and prostate and in fetal kidney, spleen, and skeletal muscle. A GFP-Dirc1 fusion protein was expressed in vitro and a polyclonal anti-Dircl peptide serum was prepared. A panel of cancer and cancer-derived cell line DNAs was examined for DIRC1 mutations, but only a rare polymorphism was observed. Two familial tumors showed loss of the derivative 3 chromosome, as observed in a Dutch kindred with t(2;3)associated renal cancers. Mutations in the second DIRC1 allele were not detected. Further studies will be required to determine if disruption of the DIRC1 gene contributed to development of the associated familial clear cell renal cancers. PMID:11587072

  4. The mouse B cell-specific mb-1 gene encodes an immunoreceptor tyrosine-based activation motif (ITAM) protein that may be evolutionarily conserved in diverse species by purifying selection

    PubMed Central

    Sims, Richard; Vandergon, Virginia Oberholzer

    2015-01-01

    The B-lymphocyte accessory molecule Ig-alpha (Ig-?) is encoded by the mouse B cell-specific gene (mb-1), and along with the Ig-beta (Ig-?) molecule and a membrane bound immunoglobulin (mIg) makes up the B-cell receptor (BCR). Ig-? and Ig-? form a heterodimer structure that upon antigen binding and receptor clustering primarily initiates and controls BCR intracellular signaling via a phosphorylation cascade, ultimately triggering an effector response. The signaling capacity of Ig-? is contained within its immunoreceptor tyrosine-based activation motif (ITAM), which is also a key component for intracellular signaling initiation in other immune cell-specific receptors. Although numerous studies have been devoted to the mb-1 gene product, Ig-?, and its signaling mechanism, an evolutionary analysis of the mb-1 gene has been lacking until now. In this study, mb-1 coding sequences from 19 species were compared using Bayesian inference. Analysis revealed a gene phylogeny consistent with an expected species divergence pattern, clustering species from the primate order separate from lower mammals and other species. In addition, an overall comparison of non-synonymous and synonymous nucleotide mutational changes suggests that the mb-1 gene has undergone purifying selection throughout its evolution. PMID:21688146

  5. T cell CD40LG gene expression and the production of IgG by autologous B cells in systemic lupus erythematosus

    PubMed Central

    Zhou, Ying; Yuan, Jun; Pan, Yujun; Fei, Yiping; Qiu, Xiangning; Hu, Nan; Luo, Yongqi; Lei, Wenzhi; Li, Yaping; Long, Hai; Sawalha, Amr H; Richardson, Bruce; Lu, Qianjin

    2009-01-01

    CD40 ligand (CD40LG), encoded on the X chromosome, has been reported to be overexpressed on lupus Tcells. Herein, we investigated the effect of DNA demethylation on Tcell CD40LG expression and the production of IgG by autologous B cells in lupus. We found normal human T cells transfected with CD40LG induced autologous B cell activation and plasma cell differentiation. Both female lupus CD4+ T cells and demethylating agents treated CD4+ T cells overexpressed CD40LG mRNA. Further, lupus T cells from both genders or demethylated CD4+ T cells from healthy women overstimulated autologous B cells, and this could be reversed with anti-CD40LG Ab in only females. We demonstrated that female lupus CD4+ T cells and demethylated CD4+ T cells express high level of CD40LG and overstimulate B cells to produce IgG. This is due to DNA demethylation and thereby reactivation of the inactive X chromosome in female. PMID:19520616

  6. B Cells, Antibodies, and More.

    PubMed

    Hoffman, William; Lakkis, Fadi G; Chalasani, Geetha

    2016-01-01

    B cells play a central role in the immunopathogenesis of glomerulonephritides and transplant rejection. B cells secrete antibodies that contribute to tissue injury via multiple mechanisms. In addition, B cells contribute to disease pathogenesis in autoimmunity and alloimmunity by presenting antigens as well as providing costimulation and cytokines to T cells. B cells also play an immunomodulatory role in regulating the immune response by secreting cytokines that inhibit disease onset and/or progression. B cell-targeted approaches for treating immune diseases of the kidney and other organs have gained significant momentum. However, much remains to be understood about B-cell biology in order to determine the timing, duration, and context of optimal therapeutic response to B cell-targeted approaches. In this review, we discuss the multifaceted roles of B cells as enhancers and regulators of immunity with relevance to kidney disease and transplantation. PMID:26700440

  7. The complete mitochondrial genome sequence of Cynoglossus abbreviatus (Pleuronectiformes: Cynoglossidae) with control region translocation and tRNA-Gln gene inversion.

    PubMed

    Shi, Wei; Gong, Li; Kong, Xiao-Yu

    2014-11-27

    Abstract Cynoglossus abbreviatus (Cynoglossidae, Soleoidei) is characterized by a bilaterally asymmetrical with both eyes on the left side. In this study, the complete mitogenome of this tongue sole has been reported for the first time. The gene order in C. abbreviatus mitogenome possesses a novel rearrangement like other tonguefish. The tRNA-Gln gene moves from the light strand to the heavy strand, accompanied by tRNA-Ile gene shuffling, leaving a large non-coding region (88?bp) between these two tRNAs. Additionally, the control region translocates to the place between ND1 and tRNA-Gln genes. The total length is 16,417?bp, with 30.9%, 29.5%, 24.9% and 14.7% for A, T, C and G, respectively (60.4% for AT content). These molecular data will provide useful information about the mechanism of gene reorganization in Cynoglossidae mitogenome and further phylogenetic study on Pleuronectiformes. PMID:25427811

  8. From Gene Amplification to V(D)J Recombination and Back: a Personal Account of My Early Years in B Cell Biology

    PubMed Central

    Alt, Frederick W.

    2008-01-01

    Summary I have been invited to write a short historical review in the context of being a co-recipient with Klaus Rajewsky and Fritz Melchers of the 2007 Novartis Prize in Basic Immunology that was given in the general area of the molecular biology of B cells. In this review, I cover the main points of the short talk that I presented at the Award Ceremony at the International Immunology Congress in Rio de Janeiro, Brazil. This talk focused primarily on the work and people involved early on in generating the models and ideas that have formed the basis for my ongoing efforts in the areas of V(D)J recombination and B cell Development. PMID:17972338

  9. The majority of human memory B cells recognizing RhD and tetanus resides in IgM+ B cells.

    PubMed

    Della Valle, Luciana; Dohmen, Serge E; Verhagen, Onno J H M; Berkowska, Magdalena A; Vidarsson, Gestur; Ellen van der Schoot, C

    2014-08-01

    B cell memory to T cell-dependent (TD) Ags are considered to largely reside in class-switched CD27(+) cells. However, we previously observed that anti-RhD (D) Igs cloned from two donors, hyperimmunized with D(+) erythrocytes, were predominantly of the IgM isotype. We therefore analyzed in this study the phenotype and frequency of D- and tetanus toxoid-specific B cells by culturing B cells in limiting dilution upon irradiated CD40L-expressing EL4.B5 cells and testing the culture supernatant. Most Ag-specific B cells for both TD Ags were found to reside in the IgM-expressing B cells, including CD27(-) B cells, in both hyperimmunized donors and nonhyperimmunized volunteers. Only shortly after immunization a sharp increase in Ag-specific CD27(+)IgG(+) B cells was observed. Next, B cells were enriched with D(+) erythrocyte ghosts and sorted as single cells. Sequencing of IGHV, IGLV, IGKV, and BCL6 genes from these D-specific B cell clones demonstrated that both CD27(-)IgM(+) and CD27(+)IgM(+) B cells harbored somatic mutations, documenting their Ag-selected nature. Furthermore, sequencing revealed a clonal relationship between the CD27(-)IgM(+), CD27(+)IgM(+), and CD27(+)IgG(+) B cell subsets. These data strongly support the recently described multiple layers of memory B cells to TD Ags in mice, where IgM(+) B cells represent a memory reservoir which can re-enter the germinal center and ensure replenishment of class-switched memory CD27(+) B cells from Ag-experienced precursors. PMID:24965774

  10. Close proximity to Igh is a contributing factor to AID mediated translocations

    PubMed Central

    Rocha, Pedro P.; Micsinai, Mariann; Kim, JungHyun Rachel; Hewitt, Susannah L.; Souza, Patricia P.; Trimarchi, Thomas; Strino, Francesco; Parisi, Fabio; Kluger, Yuval; Skok, Jane A.

    2013-01-01

    Summary Class switch recombination (CSR) has the potential to generate genomic instability in B cells as activation-induced cytidine deaminase (AID), which mediates this process, is known to target many sites outside Igh. Nonetheless we do not fully understand what factors influence AID targeting genome-wide. Given that errors in CSR can lead to dangerous, oncogenic chromosomal translocations it is important to identify the elements that determine which genes are at risk of being ‘hit’ and could be involved in aberrant rearrangements. Here we have investigated the influence of nuclear organization in determining ‘off-target’ activity and the choice of fusion partners. Our studies indicate that the vast majority of known AID-mediated Igh translocation partners are found in chromosomal domains that contact this locus during class switching. Further, these interaction domains can be used to identify other genes that are hit by AID. PMID:22864115

  11. Fusion between CIC and DUX4 up-regulates PEA3 family genes in Ewing-like sarcomas with t(4;19)(q35;q13) translocation.

    PubMed

    Kawamura-Saito, Miho; Yamazaki, Yukari; Kaneko, Keiko; Kawaguchi, Noriyoshi; Kanda, Hiroaki; Mukai, Hiroyuki; Gotoh, Takahiro; Motoi, Tohru; Fukayama, Masashi; Aburatani, Hiroyuki; Takizawa, Toichiro; Nakamura, Takuro

    2006-07-01

    Ewing's family tumors (EFTs) are highly malignant tumors arising from bone and soft tissues that exhibit EWS-FLI1 or variant EWS-ETS gene fusions in more than 85% of the cases. Here we show that CIC, a human homolog of Drosophila capicua which encodes a high mobility group box transcription factor, is fused to a double homeodomain gene DUX4 as a result of a recurrent chromosomal translocation t(4;19)(q35;q13). This translocation was seen in two cases of soft tissue sarcoma diagnosed as Ewing-like sarcoma. CIC-DUX4 exhibits a transforming potential for NIH 3T3 fibroblasts, and as a consequence of fusion with a C-terminal fragment of DUX4, CIC acquires an enhanced transcriptional activity, suggesting that expression of its downstream targets might be deregulated. Gene expression analysis identified the ETS family genes, ERM/ETV5 and ETV1, as potential targets for the gene product of CIC-DUX4. Indeed, CIC-DUX4 directly binds the ERM promoter by recognizing a novel target sequence and significantly up-regulates its expression. This study clarifies the function of CIC and its role in tumorigenesis, as well as the importance of the PEA3 subclass of ETS family proteins in the development of EFTs arising through mechanisms different from those involving EWS-ETS chimeras. Moreover, the study identifies the role of DUX4 that is closely linked to facioscapulohumeral muscular dystrophy in transcriptional regulation. PMID:16717057

  12. Climate-Driven Reshuffling of Species and Genes: Potential Conservation Roles for Species Translocations and Recombinant Hybrid Genotypes

    PubMed Central

    Scriber, Jon Mark

    2013-01-01

    Comprising 50%–75% of the world’s fauna, insects are a prominent part of biodiversity in communities and ecosystems globally. Biodiversity across all levels of biological classifications is fundamentally based on genetic diversity. However, the integration of genomics and phylogenetics into conservation management may not be as rapid as climate change. The genetics of hybrid introgression as a source of novel variation for ecological divergence and evolutionary speciation (and resilience) may generate adaptive potential and diversity fast enough to respond to locally-altered environmental conditions. Major plant and herbivore hybrid zones with associated communities deserve conservation consideration. This review addresses functional genetics across multi-trophic-level interactions including “invasive species” in various ecosystems as they may become disrupted in different ways by rapid climate change. “Invasive genes” (into new species and populations) need to be recognized for their positive creative potential and addressed in conservation programs. “Genetic rescue” via hybrid translocations may provide needed adaptive flexibility for rapid adaptation to environmental change. While concerns persist for some conservationists, this review emphasizes the positive aspects of hybrids and hybridization. Specific implications of natural genetic introgression are addressed with a few examples from butterflies, including transgressive phenotypes and climate-driven homoploid recombinant hybrid speciation. Some specific examples illustrate these points using the swallowtail butterflies (Papilionidae) with their long-term historical data base (phylogeographical diversity changes) and recent (3-decade) climate-driven temporal and genetic divergence in recombinant homoploid hybrids and relatively recent hybrid speciation of Papilio appalachiensis in North America. Climate-induced “reshuffling” (recombinations) of species composition, genotypes, and genomes may become increasingly ecologically and evolutionarily predictable, but future conservation management programs are more likely to remain constrained by human behavior than by lack of academic knowledge. PMID:26462579

  13. Smith-Lemli-Opitz syndrome in a female with a de novo, balanced translocation involving 7q32: Probable disruption of an SLOS gene

    SciTech Connect

    Wallace, M.; Zori, R.T.; Alley, T.; Whidden, E.; Gray, B.A.; Williams, C.A.

    1994-05-01

    A 3-month-old infant girl had manifestations of the Smith-Lemli-Opitz syndrome (SLOS) including typical positional anomalies of the limbs, apparent Hirschsprung disease, cataracts, ptosis, anteverted nares, cleft of the posterior palate, small tongue, broad maxillary alveolar ridges, and abnormally low serum cholesterol levels. Chromosomal analysis showed a de novo balanced translocation interpreted as 46,XX,t(7;20)(q32.1;q13.2). We hypothesize that the translocation breakpoint in this case interrupts one SLOS allele and that the other allele at the same locus has a more subtle mutation that was inherited from the other parent. This case, as well as cytogenetic observations in other SLOS cases, suggests that SLOS could be due to autosomal recessive mutation at a gene in 7q32. 33 refs., 3 figs., 1 tab.

  14. Entropic effects in formation of chromosome territories: towards understanding of radiation-induced gene translocation frequency

    NASA Astrophysics Data System (ADS)

    Gudowska-Nowak, Ewa; Ritter, Sylvia; Durante, Marco; Deperas-Standylo, Joanna; Ciesla, Michal

    2012-07-01

    A detailed understanding of structural organization of biological target, such as geometry of an inter-phase chromosome, is an essential prerequisite for gaining deeper insight into relationship between radiation track structure and radiation-induced biological damage [1]. In particular, coupling of biophysical models aimed to describe architecture of chromosomes and their positioning in a cell nucleus [2-4] with models of local distribution of ionizations caused by passing projectiles, are expected to result in more accurate estimates of aberration induction caused by radiation. There is abundant experimental evidence indicating that arrangements of chromosomes in eukaryotic cell nucleus is non-random and has been evolutionary conserved in specific cell types. Moreover, the radial position of a given chromosome territory (CT) within the cell nucleus has been shown to correlate with its size and gene density. Usually it is assumed that chromosomal geometry and positioning result from the action of specific forces acting locally, such as hydrogen bonds, electrostatic, Van der Waals or hydrophobic interactions operating between nucleosomes and within their interiors. However, it is both desirable and instructive to learn to what extend organization of inter-phase chromosomes is affected by nonspecific entropic forces. In this study we report results of a coarse-grained analysis of a chromatin structure modeled by two distinct approaches. In the first method, we adhere to purely statistical analysis of chromatin packing within a chromosome territory. On the basis of the polymer theory, the chromatin fiber of diameter 30nm is approximated by a chain of spheres, each corresponding to about 30 kbp. Random positioning of the center of the domain is repeated for 1000 spherical nuclei. Configuration of the domain is determined by a random packing of a polymer (a string of identical beads) in estimated fraction of space occupied by a chromosome of a given length and mass. The degree of condensation of the chromatin fiber is modeled by changing length of the string: e.g. loosening of the structure is achieved by distributing the chromosome mass into a higher number of smaller beads and tighter configuration corresponds to a lower number of fragments (balls) with a bigger radius. Additionally, for each configuration, a degree of possible overlapping between domains is assumed. This procedure effectively intensifies loosening/tightening of the chromosome structure by changing the radial dimension of the domain while keeping a constant volume of the polymer chain. Such a positioning model is confronted with a minimalistic molecular dynamics model [5] on a similar structure, in which a chain of beads becomes connected by entropic spring energy and subjected to thermal fluctuations. Comparison of both Monte Carlo models allows to discuss variability of possible configurations as observed in static and dynamic models of chromosome territories along with the effect of compaction and relative arrangements of territorial polymer structures. Acknowledgements: Project is operated within the Foundation for Polish Science International Ph.D. Projects Programme co-financed by the European Regional Development Fund covering, under the agreement no. MPD/2009/6, the Jagiellonian University International Ph.D. Studies in Physics of Complex Systems. References: [1] F. Ballarini, M. Biaggi, and A. Ottolenghi, Radiation Protection Dosimetry 99, 175 (2002). [2] M. Nicodemi and A. Prisco, Biophysical Journal 96, 2168 (2009). [3] P. Cook and D. Marenduzzo, Journal of Cell Biology 186, 825 (2009). [4] M. Tark-Dame, R. van Driel, and D. Heermann, Journal of Cell Science 124, 839 (2011). [5] W. Swope, H. Andersen, P. Berens, and K. Wilson, J. Chem. Phys. 76, 637 (1982).

  15. Ibrutinib for B cell malignancies

    PubMed Central

    2014-01-01

    Research over the role of Bruton’s agammaglobulinemia tyrosine kinase (BTK) in B-lymphocyte development, differentiation, signaling and survival has led to better understanding of the pathogenesis of B-cell malignancies. Down-regulation of BTK activity is an attractive novel strategy for treating patients with B-cell malignancies. Ibrutinib (PCI-32765), a potent inhibitor of BTK induces impressive responses in B-cell malignancies through irreversible bond with cysteine-481 in the active site of BTK (TH/SH1 domain) and inhibits BTK phosphorylation on Tyr223. This review discussed in details the role of BTK in B-cell signaling, molecular interactions between B cell lymphoma/leukemia cells and their microenvironment. Clinical trials of the novel BTK inhibitor, ibrutinib (PCI-32765), in B cell malignancies were summarized. PMID:24472371

  16. Structure of the human receptor tyrosine phosphatase gamma gene (PTPRG) and relation to the familial RCC t(3;8) chromosome translocation.

    PubMed

    Kastury, K; Ohta, M; Lasota, J; Moir, D; Dorman, T; LaForgia, S; Druck, T; Huebner, K

    1996-03-01

    The receptor protein tyrosine phosphatase gamma gene, PTP gamma (locus name PTPRG), was previously mapped to chromosome region 3p14.2, within a 2- to 4-Mb region centromeric to the 3p14.2 breakpoint of the t(3;8) familial renal cell carcinoma (RCC)-associated constitutional chromosome translocation. Because of its chromosomal position, its enzymatic properties as a receptor phosphatase, which might oppose a growth activating kinase activity, its homozygous deletion in murine L cells, and its transcriptional activity in numerous normal tissues, including kidney, the PTP gamma gene was an attractive tumor suppressor gene candidate for renal cell carcinoma. To determine whether the PTP gamma gene was a target of loss of heterozygosity or mutation in RCCs and to determine its map position relative to the t(3;8) break at 3p14.2, we have isolated YAC and lambda genomic clones for the PTP gamma gene and other 3p14.2 markers and determined the relative positions of the t(3;8) break, a 3p14.2 de novo break possibly in a fragile site, and the 5' end of the PTP gamma gene. Additionally, the genomic structure, position of the proximal promotor, and intron-exon border sequences of the 30-exon 780-kb PTP gamma gene have been determined, which will facilitate analysis of the PTP gamma gene in tumors. PMID:8833149

  17. DAP-kinase loss of expression in various carcinoma and B-cell lymphoma cell lines: possible implications for role as tumor suppressor gene

    E-print Network

    Kimchi, Adi

    profound examples of death controlling genes involved in cancer are Bcl-2 and p53. The Bcl-2 gene, 1993; Clarke et al., 1993). To date, p53 is the most commonly mutated tumor suppressor gene, the p53 protein is a positive mediator of apoptosis, and therefore its loss or inactivation often leads

  18. Genomic Comparison of Translocating and Non-Translocating Escherichia coli

    PubMed Central

    Bachmann, Nathan L.; Katouli, Mohammad; Polkinghorne, Adam

    2015-01-01

    Translocation of E. coli across the gut epithelium can result in fatal sepsis in post-surgical patients. In vitro and in vivo experiments have identified the existence of a novel pathotype of translocating E. coli (TEC) that employs an unknown mechanism for translocating across epithelial cells to the mesenteric lymph nodes and the blood stream in both humans and animal models. In this study the genomes of four TEC strains isolated from the mesenteric lymph nodes of a fatal case of hospitalised patient (HMLN-1), blood of pigs after experimental shock (PC-1) and after non-lethal haemorrhage in rats (KIC-1 and KIC-2) were sequenced in order to identify the genes associated with their adhesion and/or translocation. To facilitate the comparison, the genomes of a non-adhering, non-translocating E. coli (46–4) and adhering but non-translocating E. coli (73–89) were also sequenced and compared. Whole genome comparison revealed that three (HMLN-1, PC-1 and KIC-2) of the four TEC strains carried a genomic island that encodes a Type 6 Secretion System that may contribute to adhesion of the bacteria to gut epithelial cells. The human TEC strain HMLN-1 also carried the invasion ibeA gene, which was absent in the animal TEC strains and is likely to be associated with host-specific translocation. Phylogenetic analysis revealed that the four TEC strains were distributed amongst three distinct E. coli phylogroups, which was supported by the presence of phylogroup specific fimbriae gene clusters. The genomic comparison has identified potential genes that can be targeted with knock-out experiments to further characterise the mechanisms of E. coli translocation. PMID:26317913

  19. Molecular and cytogenetic characterization of expanded B-cell clones from multiclonal versus monoclonal B-cell chronic lymphoproliferative disorders

    PubMed Central

    Henriques, Ana; Rodríguez-Caballero, Arancha; Criado, Ignacio; Langerak, Anton W.; Nieto, Wendy G.; Lécrevisse, Quentin; González, Marcos; Cortesão, Emília; Paiva, Artur; Almeida, Julia; Orfao, Alberto

    2014-01-01

    Chronic antigen-stimulation has been recurrently involved in the earlier stages of monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The expansion of two or more B-cell clones has frequently been reported in individuals with these conditions; potentially, such coexisting clones have a greater probability of interaction with common immunological determinants. Here, we analyzed the B-cell receptor repertoire and molecular profile, as well as the phenotypic, cytogenetic and hematologic features, of 228 chronic lymphocytic leukemia-like and non-chronic lymphocytic leukemia-like clones comparing multiclonal (n=85 clones from 41 cases) versus monoclonal (n=143 clones) monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The B-cell receptor of B-cell clones from multiclonal cases showed a slightly higher degree of HCDR3 homology than B-cell clones from mono clonal cases, in association with unique hematologic (e.g. lower B-lymphocyte counts) and cytogenetic (e.g. lower frequency of cytogenetically altered clones) features usually related to earlier stages of the disease. Moreover, a subgroup of coexisting B-cell clones from individual multiclonal cases which were found to be phylogenetically related showed unique molecular and cytogenetic features: they more frequently shared IGHV3 gene usage, shorter HCDR3 sequences with a greater proportion of IGHV mutations and del(13q14.3), than other unrelated B-cell clones. These results would support the antigen-driven nature of such multiclonal B-cell expansions, with potential involvement of multiple antigens/epitopes. PMID:24488564

  20. Transcription of the Tollip gene is elevated in intestinal epithelial cells through impaired O-GlcNAcylation-dependent nuclear translocation of the negative regulator Elf-1

    SciTech Connect

    Sugi, Yutaka; Takahashi, Kyoko; Nakano, Kou; Hosono, Akira; Kaminogawa, Shuichi

    2011-09-09

    Highlights: {yields} Transcriptional activation of the Tollitip gene is higher in IECs than in monocytes. {yields} Nt -194/-186 region acts as a cis-element and is recognized by Elf-1. {yields} Elf-1 suppresses Tollip gene transcription in monocytes but not in IECs. {yields} O-GlcNAc modification is necessary for nuclear translocation of Elf-1. {yields} O-GlcNAcylation-dependent nuclear translocation of Elf-1 is impaired in IECs. -- Abstract: Intestinal epithelial cells (IECs) must be tolerant of the large number of commensal bacteria inhabiting the intestinal tract to avoid excessive inflammatory reactions. Toll-interacting protein (Tollip), a negative regulator of Toll-like receptor signaling, is known to be expressed at high levels in IECs, and to thereby contribute to the hyporesponsiveness of IECs to commensals. In this study, we analyzed the underlying mechanisms for elevated transcription of the Tollip gene in IECs using a human IEC line, Caco-2, and a human monocyte line, THP-1, as a control. Elf-1 was identified as a transcription factor that negatively regulates Tollip gene expression. The transcription factor Elf-1 was localized in the nucleus by O-linked N-acetylglucosamine (O-GlcNAc) modification, whereas the unmodified form was detected only in the cytoplasm. Comparison of Caco-2 and THP-1 cells revealed that O-GlcNAc modification of Elf-1 was significantly lower in IECs than in monocytes. Collectively, the results indicate that insufficient O-GlcNAc modification prevents Elf-1-mediated transcriptional repression and thereby upregulates Tollip gene expression in IECs.

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

    PubMed Central

    Ok, Chi Young; Chen, Jiayu; Xu-Monette, Zijun Y.; Tzankov, Alexandar; Manyam, Ganiraju C.; Li, Ling; Visco, Carlo; Montes-Moreno, Santiago; Dybkær, Karen; Chiu, April; Orazi, Attilio; Zu, Youli; Bhagat, Govind; Richards, Kristy L.; Hsi, Eric D.; Choi, William W. L.; Han van Krieken, J.; Huh, Jooryung; Zhao, Xiaoying; Ponzoni, Maurilio; Ferreri, Andrés J. M.; Bertoni, Francesco; Farnen, John P.; Møller, Michael B.; Piris, Miguel A.; Winter, Jane N.; Medeiros, L. Jeffrey; Young, Ken H.

    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 and gene set enrichment analysis. Results are analyzed in correlation with cell-of-origin, 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 survival (OS) and progression-free survival (PFS) in de novo DLBCL patients. When DLBCL cases were stratified according to cell-of-origin or MYC expression, pSTAT3 expression did not predict inferior outcome, respectively. Multivariate analysis showed that the prognostic predictability of pSTAT3 expression was due to its association with the ABC subtype, MYC expression and adverse clinical features. Gene expression profiling demonstrated up-regulation of genes, which can potentiate function of STAT3. Gene set enrichment analysis showed the JAK-STAT pathway to be enriched in pSTAT3+ DLBCL. Conclusions The results of this study provide a rationale for the ongoing successful clinical trials targeting the JAK-STAT pathway in DLBCL. PMID:25124685

  2. Stemness of B cell progenitors in multiple myeloma bone marrow

    PubMed Central

    Boucher, Kelly; Parquet, Nancy; Widen, Raymond; Shain, Kenneth; Baz, Rachid; Alsina, Melissa; Koomen, John; Anasetti, Claudio; Dalton, William; Perez, Lia E.

    2012-01-01

    Purpose In myeloma, B cells and plasma cells show a clonal relationship. Clonotypic B cells may represent a tumor-initiating compartment or cancer stem cell responsible for minimal residual disease in myeloma. Experimental Design We report a study of 58 patients with myeloma at time of diagnosis or relapse. B cells in bone marrow were evaluated by multicolor flow cytometry and sorting. Clonality was determined by light chain and/or immunoglobulin chain gene rearrangement PCR. We also determined aldehyde dehydrogenase activity and colony formation growth. Drug sensitivity was tested with conventional and novel agents. Results Marrow CD19+ cells express a light chain identical to plasma cells and are therefore termed light chain restricted (LCR). The LCR B cell mass is small in both newly diagnosed and relapsed patients (?1%). Few marrow LCR B cells (~10%) are CD19+/CD34+, with the rest being more differentiated CD19+/CD34? B cells. Marrow LCR CD19+ B cells exhibit enhanced aldehyde dehydrogenase activity versus healthy controls. Both CD19+/CD34+ and CD19+/CD34? cells showed colony formation activity, with colony growth efficiency optimized when stroma-conditioned medium was used. B cell progenitors showed resistance to melphalan, lenalidomide, and bortezomib. Panobinostat, a histone deacetylase inhibitor, induced apoptosis of LCR B cells and CD138+ cells. LCR B cells are CD117, survivin, and Notch positive. Conclusions We propose that antigen-independent B cell differentiation stages are involved in disease origination and progression in myeloma. Further investigations of myeloma putative stem cell progenitors may lead to novel treatments to eradicate the potential reservoir of minimal residual disease. PMID:22988056

  3. Transcriptional Control of Early T and B Cell Developmental Choices

    PubMed Central

    Rothenberg, Ellen V.

    2014-01-01

    T and B cells share a common somatic gene rearrangement mechanism for assembling the genes that code for their antigen receptors and developmental pathways with many parallels. Shared usage of basic helix-loop-helix E proteins as transcriptional drivers underlies these common features. However, the transcription factor networks in which these E proteins are embedded are different both in membership and in architecture for T and B cell gene regulatory programs. These differences permit lineage commitment decisions to be made in different hierarchical orders. Furthermore, in a contrast to B-cell gene networks, the T-cell gene network architecture for effector differentiation is sufficiently modular so that E protein inputs can be removed. Complete “T-cell-like” effector differentiation can proceed without T-cell receptor rearrangement or selection when E proteins are neutralized, yielding natural killer and other innate lymphoid cells. PMID:24471430

  4. Pre-B cell receptor signaling in acute lymphoblastic leukemia

    PubMed Central

    Nahar, Rahul; Müschen, Markus

    2014-01-01

    B cell lineage ALL represents by far the most frequent malignancy in children and is also common in adults. Despite significant advances over the past four decades, cytotoxic treatment strategies have recently reached a plateau with cure rates at 80 percent for children and 55 percent for adults. Relapse after cytotoxic drug treatment, initial drug-resistance and dose-limiting toxicity are among the most frequent complications of current therapy approaches. For this reason, pathway-specific treatment strategies in addition to cytotoxic drug treatment seem promising to further improve therapy options for ALL patients. In a recent study on 111 cases of pre-B cell-derived human ALL, we found that ALL cells carrying a BCR-ABL1-gene rearrangement lack expression of a functional pre-B cell receptor in virtually all cases. In a proof-of-principle experiment, we studied pre-B cell receptor function during progressive leukemic transformation of pre-B cells in BCR-ABL1-transgenic mice: Interestingly, signaling from the pre-B cell receptor and the oncogenic BCR-ABL1 kinase are mutually exclusive and only “crippled” pre-B cells that fail to express a functional pre-B cell receptor are permissive to transformation by BCR-ABL1. PMID:19901533

  5. B-cell-activating factor inhibits CD20-mediated and B-cell receptor-mediated apoptosis in human B cells

    PubMed Central

    Saito, Yohei; Miyagawa, Yoshitaka; Onda, Keiko; Nakajima, Hideki; Sato, Ban; Horiuchi, Yasuomi; Okita, Hajime; Katagiri, Yohko U; Saito, Masahiro; Shimizu, Toshiaki; Fujimoto, Junichiro; Kiyokawa, Nobutaka

    2008-01-01

    B-cell-activating factor (BAFF) is a survival and maturation factor for B cells belonging to the tumour necrosis factor superfamily. Among three identified functional receptors, the BAFF receptor (BAFF-R) is thought to be responsible for the effect of BAFF on B cells though details of how remain unclear. We determined that a hairy-cell leukaemia line, MLMA, expressed a relatively high level of BAFF-R and was susceptible to apoptosis mediated by either CD20 or B-cell antigen receptor (BCR). Using MLMA cells as an in vitro model of mature B cells, we found that treatment with BAFF could inhibit apoptosis mediated by both CD20 and BCR. We also observed, using immunoblot analysis and microarray analysis, that BAFF treatment induced activation of nuclear factor-?B2 following elevation of the expression level of Bcl-2, which may be involved in the molecular mechanism of BAFF-mediated inhibition of apoptosis. Interestingly, BAFF treatment was also found to induce the expression of a series of genes, such as that for CD40, related to cell survival, suggesting the involvement of a multiple mechanism in the BAFF-mediated anti-apoptotic effect. MLMA cells should provide a model for investigating the molecular basis of the effect of BAFF on B cells in vitro and will help to elucidate how B cells survive in the immune system in which BAFF-mediated signalling is involved. PMID:18540961

  6. B Cell Subsets in Atherosclerosis

    PubMed Central

    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 by secretion of natural IgM antibodies. Conventional B-2 B cells can promote atherosclerosis through less clearly defined mechanism that may involve CD4 T cells. Yet, there may be other populations of B cells within these subsets with different phenotypes altering their impact on atherosclerosis. Additionally, the role of B cell subsets in atherosclerosis may depend on their environmental niche and/or the stage of atherogenesis. This review will highlight key findings in the evolving field of B cells and atherosclerosis and touch on the potential and importance of translating these findings to human disease. PMID:23248624

  7. B-cell lymphoma 6 and the molecular pathogenesis of diffuse large B-cell lymphoma

    PubMed Central

    Ci, Weimin; Polo, Jose M; Melnick, Ari

    2009-01-01

    Purpose of review The BCL6 transcriptional repressor is the most commonly involved oncogene in B-cell lymphomas. Sustained expression of BCL6 causes malignant transformation of germinal center (GC) B-cells. Understanding the mechanism of action of BCL6 is crucial for the study of how aberrant transcriptional programming leads to lymphomagenesis and development of targeted anti-lymphoma therapy. Recent findings Identification of BCL6 target genes indicate a critical role for BCL6 in facilitating a state of physiological genomic instability required for GC B-cells to undergo affinity maturation, and suggest its contribution to several additional cellular functions. The discovery of several layers of counter-regulatory mechanisms reveals how B-cells can control and fine-tune the potentially lymphomagenic actions of BCL6. From the biochemical standpoint, BCL6 can regulate distinct biological pathways through different cofactors. This observation explains how the biological actions of BCL6 can be physiologically controlled through separate mechanisms and affords the means for improved therapeutic targeting. The fact that patients with BCL6-dependent lymphoma can be identified based on gene signatures suggests that therapeutic trials of BCL6 inhibitors could be personalized to these individuals. Summary BCL6 plays a fundamental role in lymphomagenesis and is an excellent therapeutic target for development of improved anti-lymphoma therapeutic regimens. PMID:18536578

  8. B cell antigen receptor-induced activation of an IRAK4-dependent signaling pathway revealed by a MALT1-IRAK4 double knockout mouse model

    PubMed Central

    2011-01-01

    Background The B cell antigen receptor (BCR) and pathogen recognition receptors, such as Toll-like receptor 4 (TLR4), act in concert to control adaptive B cell responses. However, little is known about the signaling pathways that integrate BCR activation with intrinsic TLR4 stimulation. Antigen receptors initialize activation of the inducible transcription factor nuclear factor-?B (NF-?B) via recruitment of the membrane-associated guanylate kinase caspase recruitment domain protein 11 (CARD11), the adapter molecule B cell CLL/lymphoma 10 (BCL10), and the "paracaspase" mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) into lipid rafts. Upon BCR triggering, this activation strictly depends on BCL10, but not on MALT1, leading to the hypothesis that a MALT1-independent NF-?B activation pathway contributes to BCR-induced NF-?B activation downstream of BCL10. The identity of this pathway has remained elusive. Results Using genetic and biochemical approaches, we demonstrate that the IRAK4- and IRAK1-dependent TLR signaling branch is activated upon BCR triggering to induce partial NF-?B activation. BCR-induced MALT1-independent I?B degradation and B cell proliferation were inhibited in MALT1/IRAK4 double knockout B cells. Moreover, IRAK1 was recruited into lipid rafts upon BCR stimulation and activated following transient recruitment of IRAK4. Conclusion We propose that the observed crosstalk between BCR and TLR signaling components may contribute to the discrimination of signals that emanate from single and dual receptor engagement to control adaptive B cell responses. PMID:21396111

  9. Robertsonian translocations

    SciTech Connect

    1993-12-31

    Chapter 27, describes the occurrence of Robertsonian translocations (RTs), which refer to the recombination of whole chromosome arms, in both monocentric and dicentric chromosomes. The nonrandom participation of acrocentric chromosomes in RTs is documented by various methods, including unbiased ascertainment and ascertainment through trisomy, infertility, unspecified mental retardation, and Prader-Willi syndrome. Causes of nonrandom participation of chromosomes in RTs is presented, as are the following topics: segregation in carriers of RTs and segregation in sperm cells of RT carriers, interchromosomal effects and conclusions. 48 refs., 3 figs., 2 tabs.

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

    PubMed Central

    Petri, Andreas; Dybkær, Karen; Bøgsted, Martin; Thrue, Charlotte Albæk; Hagedorn, Peter H.; Schmitz, Alexander; Bødker, Julie Støve; Johnsen, Hans Erik; Kauppinen, Sakari

    2015-01-01

    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. PMID:26394393

  11. Association between gene and miRNA expression profiles and stereotyped subset #4 B-cell receptor in chronic lymphocytic leukemia.

    PubMed

    Maura, Francesco; Cutrona, Giovanna; Mosca, Laura; Matis, Serena; Lionetti, Marta; Fabris, Sonia; Agnelli, Luca; Colombo, Monica; Massucco, Carlotta; Ferracin, Manuela; Zagatti, Barbara; Reverberi, Daniele; Gentile, Massimo; Recchia, Anna Grazia; Bossio, Sabrina; Rossi, Davide; Gaidano, Gianluca; Molica, Stefano; Cortelezzi, Agostino; Di Raimondo, Francesco; Negrini, Massimo; Tassone, Pierfrancesco; Morabito, Fortunato; Ferrarini, Manlio; Neri, Antonino

    2015-11-01

    In this study we investigated specific biological and clinical features associated with chronic lymphocytic leukemia (CLL) patients carrying stereotyped BCR subset #4 (IGHV4-34) among a prospective cohort of 462 CLL/MBL patients in early stage (Binet A). All subset #4 patients (n = 16) were characterized by the IGHV mutated gene configuration, and absence of unfavorable cytogenetic lesions, NOTCH1 or SF3B1 mutations. Gene and miRNA expression profiling evidenced that the leukemic cells of subset #4 cases showed significant downregulation of WDFY4, MF2A and upregulation of PDGFA, FGFR1 and TFEC gene transcripts, as well as the upregulation of miR-497 and miR-29c. The transfection of miR-497 mimic in primary leukemic CLL cells induced a downregulation of BCL2, a known validated target of this miRNA. Our data identify biological characteristics associated with subset #4 patients, providing further evidence for the putative role of BCR in shaping the features of the tumor cells in CLL. PMID:25860243

  12. BTK Signaling in B Cell Differentiation and Autoimmunity.

    PubMed

    Corneth, Odilia B J; Klein Wolterink, Roel G J; Hendriks, Rudi W

    2016-01-01

    Since the original identification of Bruton's tyrosine kinase (BTK) as the gene defective in the primary immunodeficiency X-linked agammaglobulinemia (XLA) in 1993, our knowledge on the physiological function of BTK has expanded impressively. In this review, we focus on the role of BTK during B cell differentiation in vivo, both in the regulation of expansion and in the developmental progression of pre-B cells in the bone marrow and as a crucial signal transducer of signals downstream of the IgM or IgG B cell antigen receptor (BCR) in mature B cells governing proliferation, survival, and differentiation. In particular, we highlight BTK function in B cells in the context of host defense and autoimmunity. Small-molecule inhibitors of BTK have very recently shown impressive anti-tumor activity in clinical studies in patients with various B cell malignancies. Since promising effects of BTK inhibition were also seen in experimental animal models for lupus and rheumatoid arthritis, BTK may be a good target for controlling autoreactive B cells in patients with systemic autoimmune disease. PMID:26341110

  13. Curcumin diminishes the impacts of hyperglycemia on the activation of hepatic stellate cells by suppressing membrane translocation and gene expression of glucose transporter-2

    PubMed Central

    Lin, Jianguo; Chen, Anping

    2011-01-01

    Diabetes is featured by elevated levels of blood glucose, i.e. hyperglycemia, which might be a risk factor for hepatic fibrogenesis in patients with non-alcoholic steatohepatitis. Hepatic stellate cells (HSCs) are the major effectors during hepatic fibrogenesis. This study was designed to evaluate impacts of high levels of glucose on HSC activation, assess roles of the phytochemical curcumin in attenuating the glucose impacts, and elucidate underlying mechanisms. In this report, levels of intracellular glucose were measured. Contents and gene expression of glucose transporter-2 (GLUT2) in cell fractions were examined. Levels of cellular glutathione and oxidative stress were analyzed. We observed that high levels of glucose induced cell proliferation, type I collagen production and expression of genes relevant to HSC activation, and elevated intracellular glucose levels in cultured HSCs. Curcumin eliminated the stimulatory impacts. Curcumin abrogated the membrane translocation of GLUT2 by interrupting the p38 MAPK signaling pathway. In addition, curcumin suppressed glut2 expression by stimulating the activity of peroxisome proliferator-activated receptor-gamma (PPAR?) and de novo synthesis of glutathione. In conclusion, hyperglycemia stimulated HSC activation in vitro by increasing intracellular glucose, which was eliminated by curcumin by blocking the membrane translocation of GLUT2 and suppressing glut2 expression. The latter was mediated by activating PPAR? and attenuating oxidative stress. Our results presented evidence to impacts of hyperglycemia on stimulating HSC activation and hepatic fibrogenesis, and provided novel insights into the mechanisms by which curcumin eliminated the hyperglycemia-caused HSC activation and potential therapeutic strategies for treatment of diabetes-associated hepatic fibrogenesis. PMID:21195127

  14. Activation of Wnt/beta-catenin pathway mediates growth and survival in B-cell progenitor acute lymphoblastic leukaemia.

    PubMed

    Khan, Naveed I; Bradstock, Kenneth F; Bendall, Linda J

    2007-08-01

    This study investigated the response of acute lymphoblastic leukaemia (ALL) cells to Wnt proteins. Accumulation of beta-catenin was measured by Western blotting and immunofluorescence microscopy. Reverse transcription polymerase chain reaction (RT-PCR) analysis of B-cell progenitor acute lymphoblastic leukaemia (ALL) cells revealed expression of Wnt genes, including WNT2B in 33%, WNT5A in 42%, WNT10B in 58% and WNT16B in 25% of cases. The Wnt receptors, (Frizzled) FZD7 and FZD8 were also expressed in most cases while FZD3, FZD4 and FZD9 were occasionally detected. Stimulation of ALL cells with Wnt-3a activated canonical Wnt signalling with increased expression and nuclear translocation of beta-catenin. This resulted in a 1.7- to 5.3-fold increase in cell proliferation, which was associated with enhanced cell cycle entry. A significant increase in the survival of ALL cells under conditions of serum deprivation was also observed. Microarray analysis and quantitative RT-PCR revealed that activation of the Wnt/beta-catenin pathway led to altered expression of genes involved in cell cycle regulation and apoptosis in normal and leukaemic B-cell progenitors. Our results demonstrate that Wnt-3a provides proliferative and survival cues in ALL cells. This data suggests that targeting the Wnt signalling pathway may be a useful therapeutic strategy in ALL. PMID:17614820

  15. Impact of Gastrointestinal Bacillus anthracis Infection on Hepatic B Cells.

    PubMed

    Colliou, Natacha; Sahay, Bikash; Zadeh, Mojgan; Owen, Jennifer L; Mohamadzadeh, Mansour

    2015-09-01

    Ingestion of Bacillus anthracis results in rapid gastrointestinal (GI) infection, known as GI anthrax. We previously showed that during GI anthrax, there is swift deterioration of intestinal barrier function leading to translocation of gut-associated bacteria into systemic circulation. Additionally, we described dysfunction in colonic B cells. In concordance with our previous studies, here, we report early migration of the Sterne strain of B. anthracis along with other gut-resident bacteria into the infected murine liver. Additionally, despite a global decrease in the B cell population, we observed an increase in both B-1a and marginal zone (MZ)-like B cells. Both of these cell types are capable of producing immunoglobulins against common pathogens and commensals, which act as a general antibody barrier before an antigen-specific antibody response. Accumulation of these cells in the liver was associated with an increase in chemokine expression. These data suggest that the presence of Sterne and other commensals in the liver trigger migration of MZ-like B cells from the spleen to the liver to neutralize systemic spread. Further research is required to evaluate the possible cause of their failure to clear the infection within the liver, including the potential role of dysfunctional mitogen-activated protein kinase (MAPK) signaling. PMID:26402706

  16. Impact of Gastrointestinal Bacillus anthracis Infection on Hepatic B Cells

    PubMed Central

    Colliou, Natacha; Sahay, Bikash; Zadeh, Mojgan; Owen, Jennifer L.; Mohamadzadeh, Mansour

    2015-01-01

    Ingestion of Bacillus anthracis results in rapid gastrointestinal (GI) infection, known as GI anthrax. We previously showed that during GI anthrax, there is swift deterioration of intestinal barrier function leading to translocation of gut-associated bacteria into systemic circulation. Additionally, we described dysfunction in colonic B cells. In concordance with our previous studies, here, we report early migration of the Sterne strain of B. anthracis along with other gut-resident bacteria into the infected murine liver. Additionally, despite a global decrease in the B cell population, we observed an increase in both B-1a and marginal zone (MZ)-like B cells. Both of these cell types are capable of producing immunoglobulins against common pathogens and commensals, which act as a general antibody barrier before an antigen-specific antibody response. Accumulation of these cells in the liver was associated with an increase in chemokine expression. These data suggest that the presence of Sterne and other commensals in the liver trigger migration of MZ-like B cells from the spleen to the liver to neutralize systemic spread. Further research is required to evaluate the possible cause of their failure to clear the infection within the liver, including the potential role of dysfunctional mitogen-activated protein kinase (MAPK) signaling. PMID:26402706

  17. Evolution of B Cell Immunity

    PubMed Central

    Sunyer, J. Oriol

    2013-01-01

    Two types of adaptive immune strategies are known to have evolved in vertebrates: the VLR-based system, which is present in jawless organisms and is mediated by VLRA and VLRB lymphocytes, and the BCR/TCR-based system, which is present in jawed species and is provided by B and T cell receptors expressed on B and T cells, respectively. Here we summarize features of B cells and their predecessors in the different animal phyla, focusing the review on B cells from jawed vertebrates. We point out the critical role of nonclassical species and comparative immunology studies in the understanding of B cell immunity. Because nonclassical models include species relevant to veterinary medicine, basic science research performed in these animals contributes to the knowledge required for the development of more efficacious vaccines against emerging pathogens. PMID:25340015

  18. DHA down-regulates phenobarbital-induced cytochrome P450 2B1 gene expression in rat primary hepatocytes by attenuating CAR translocation

    SciTech Connect

    Li, C.-C.; Lii, C.-K.; Liu, K.-L.; Yang, J.-J.; Chen, H.-W.

    2007-12-15

    The constitutive androstane receptor (CAR) plays an important role in regulating the expression of detoxifying enzymes, including cytochrome P450 2B (CYP 2B). Phenobarbital (PB) induction of human CYP 2B6 and mouse CYP 2b10 has been shown to be mediated by CAR. Our previous study showed that PB-induced CYP 2B1 expression in rat primary hepatocytes is down-regulated by both n-6 and n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA); however, the mechanism for this down-regulation by DHA was previously unknown. The objective of the present study was to determine whether change in CAR translocation is involved in the down-regulation by n-6 and n-3 PUFAs of PB-induced CYP 2B1 expression in rat primary hepatocytes. We used 100 {mu}M arachidonic acid, linoleic acid, eicosapentaenoic acid, and DHA to test this hypothesis. PB triggered the translocation of CAR from the cytosol into the nucleus in a dose-dependent and time-dependent manner in our hepatocyte system, and the CAR distribution in rat primary hepatocytes was significantly affected by DHA. DHA treatment decreased PB-inducible accumulation of CAR in the nuclear fraction and increased it in the cytosolic fraction in a dose-dependent manner. The down-regulation of CYP 2B1 expression by DHA occurred in a dose-dependent manner, and a similar pattern was found for the nuclear accumulation of CAR. The results of immunoprecipitation showed a CAR/RXR heterodimer bound to nuclear receptor binding site 1 (NR-1) of the PB-responsive enhancer module (PBREM) of the CYP 2B1gene. The EMSA results showed that PB-induced CAR binding to NR-1 was attenuated by DHA. Taken together, these results suggest that attenuation of CAR translocation and decreased subsequent binding to NR-1 are involved in DHA's down-regulation of PB-induced CYP 2B1 expression.

  19. The impact of TEL-AML1 (ETV6-RUNX1) expression in precursor B cells and implications for leukaemia using three different genome-wide screening methods

    PubMed Central

    Linka, Y; Ginzel, S; Krüger, M; Novosel, A; Gombert, M; Kremmer, E; Harbott, J; Thiele, R; Borkhardt, A; Landgraf, P

    2013-01-01

    The reciprocal translocation t(12;21)(p13;q22), the most common structural genomic alteration in B-cell precursor acute lymphoblastic leukaemia in children, results in a chimeric transcription factor TEL-AML1 (ETV6-RUNX1). We identified directly and indirectly regulated target genes utilizing an inducible TEL-AML1 system derived from the murine pro B-cell line BA/F3 and a monoclonal antibody directed against TEL-AML1. By integration of promoter binding identified with chromatin immunoprecipitation (ChIP)-on-chip, gene expression and protein output through microarray technology and stable labelling of amino acids in cell culture, we identified 217 directly and 118 indirectly regulated targets of the TEL-AML1 fusion protein. Directly, but not indirectly, regulated promoters were enriched in AML1-binding sites. The majority of promoter regions were specific for the fusion protein and not bound by native AML1 or TEL. Comparison with gene expression profiles from TEL-AML1-positive patients identified 56 concordantly misregulated genes with negative effects on proliferation and cellular transport mechanisms and positive effects on cellular migration, and stress responses including immunological responses. In summary, this work for the first time gives a comprehensive insight into how TEL-AML1 expression may directly and indirectly contribute to alter cells to become prone for leukemic transformation. PMID:24121163

  20. The impact of TEL-AML1 (ETV6-RUNX1) expression in precursor B cells and implications for leukaemia using three different genome-wide screening methods.

    PubMed

    Linka, Y; Ginzel, S; Krüger, M; Novosel, A; Gombert, M; Kremmer, E; Harbott, J; Thiele, R; Borkhardt, A; Landgraf, P

    2013-01-01

    The reciprocal translocation t(12;21)(p13;q22), the most common structural genomic alteration in B-cell precursor acute lymphoblastic leukaemia in children, results in a chimeric transcription factor TEL-AML1 (ETV6-RUNX1). We identified directly and indirectly regulated target genes utilizing an inducible TEL-AML1 system derived from the murine pro B-cell line BA/F3 and a monoclonal antibody directed against TEL-AML1. By integration of promoter binding identified with chromatin immunoprecipitation (ChIP)-on-chip, gene expression and protein output through microarray technology and stable labelling of amino acids in cell culture, we identified 217 directly and 118 indirectly regulated targets of the TEL-AML1 fusion protein. Directly, but not indirectly, regulated promoters were enriched in AML1-binding sites. The majority of promoter regions were specific for the fusion protein and not bound by native AML1 or TEL. Comparison with gene expression profiles from TEL-AML1-positive patients identified 56 concordantly misregulated genes with negative effects on proliferation and cellular transport mechanisms and positive effects on cellular migration, and stress responses including immunological responses. In summary, this work for the first time gives a comprehensive insight into how TEL-AML1 expression may directly and indirectly contribute to alter cells to become prone for leukemic transformation. PMID:24121163

  1. B-cell development and functions and therapeutic options in adenosine deaminase–deficient patients

    PubMed Central

    Brigida, Immacolata; Sauer, Aisha V.; Ferrua, Francesca; Giannelli, Stefania; Scaramuzza, Samantha; Pistoia, Valentina; Castiello, Maria Carmina; Barendregt, Barbara H.; Cicalese, Maria Pia; Casiraghi, Miriam; Brombin, Chiara; Puck, Jennifer; Müller, Klaus; Notarangelo, Lucia Dora; Montin, Davide; van Montfrans, Joris M.; Roncarolo, Maria Grazia; Traggiai, Elisabetta; van Dongen, Jacques J. M.; van der Burg, Mirjam; Aiuti, Alessandro

    2015-01-01

    Background Adenosine deaminase (ADA) deficiency causes severe cellular and humoral immune defects and dysregulation because of metabolic toxicity. Alterations in B-cell development and function have been poorly studied. Enzyme replacement therapy (ERT) and hematopoietic stem cell (HSC) gene therapy (GT) are therapeutic options for patients lacking a suitable bone marrow (BM) transplant donor. Objective We sought to study alterations in B-cell development in ADA-deficient patients and investigate the ability of ERT and HSC-GT to restore normal B-cell differentiation and function. Methods Flow cytometry was used to characterize B-cell development in BM and the periphery. The percentage of gene-corrected B cells was measured by using quantitative PCR. B cells were assessed for their capacity to proliferate and release IgM after stimulation. Results Despite the severe peripheral B-cell lymphopenia, patients with ADA-deficient severe combined immunodeficiency showed a partial block in central BM development. Treatment with ERT or HSC-GT reverted most BM alterations, but ERT led to immature B-cell expansion. In the periphery transitional B cells accumulated under ERT, and the defect in maturation persisted long-term. HSC-GT led to a progressive improvement in B-cell numbers and development, along with increased levels of gene correction. The strongest selective advantage for ADA-transduced cells occurred at the transition from immature to naive cells. B-cell proliferative responses and differentiation to immunoglobulin secreting IgM after B-cell receptor and Toll-like receptor triggering were severely impaired after ERT and improved significantly after HSC-GT. Conclusions ADA-deficient patients show specific defects in B-cell development and functions that are differently corrected after ERT and HSC-GT. PMID:24506932

  2. A novel Robertsonian translocation event leads to transfer of a stem rust resistance gene (Sr52) effective against race Ug99 from Dasypyrum villosum into bread wheat.

    PubMed

    Qi, L L; Pumphrey, M O; Friebe, Bernd; Zhang, P; Qian, C; Bowden, R L; Rouse, M N; Jin, Y; Gill, B S

    2011-06-01

    Stem rust (Puccinia graminis f. sp. tritici Eriks. & E. Henn.) (the causal agent of wheat stem rust) race Ug99 (also designated TTKSK) and its derivatives have defeated several important stem rust resistance genes widely used in wheat (Triticum aestivum L.) production, rendering much of the worldwide wheat acreage susceptible. In order to identify new resistance sources, a large collection of wheat relatives and genetic stocks maintained at the Wheat Genetic and Genomic Resources Center was screened. The results revealed that most accessions of the diploid relative Dasypyrum villosum (L.) Candargy were highly resistant. The screening of a set of wheat-D. villosum chromosome addition lines revealed that the wheat-D. villosum disomic addition line DA6V#3 was moderately resistant to race Ug99. The objective of the present study was to produce and characterize compensating wheat-D. villosum whole arm Robertsonian translocations (RobTs) involving chromosomes 6D of wheat and 6V#3 of D. villosum through the mechanism of centric breakage-fusion. Seven 6V#3-specific EST-STS markers were developed for screening F(2) progeny derived from plants double-monosomic for chromosomes 6D and 6V#3. Surprisingly, although 6D was the target chromosome, all recovered RobTs involved chromosome 6A implying a novel mechanism for the origin of RobTs. Homozygous translocations (T6AS·6V#3L and T6AL·6V#3S) with good plant vigor and full fertility were selected from F(3) families. A stem rust resistance gene was mapped to the long arm 6V#3L in T6AS·6V#3L and was designated as Sr52. Sr52 is temperature-sensitive and is most effective at 16°C, partially effective at 24°C, and ineffective at 28°C. The T6AS·6V#3L stock is a new source of resistance to Ug99, is cytogenetically stable, and may be useful in wheat improvement. PMID:21437597

  3. HIV-associated memory B cell perturbations

    PubMed Central

    Hu, Zhiliang; Luo, Zhenwu; Wan, Zhuang; Wu, Hao; Li, Wei; Zhang, Tong; Jiang, Wei

    2015-01-01

    Memory B-cell depletion, hyperimmunoglobulinemia, and impaired vaccine responses are the hallmark of B cell perturbations inhuman immunodeficiency virus (HIV) disease. Although B cells are not the targets for HIV infection, there is evidence for B cell, especially memory B cell dysfunction in HIV disease mediated by other cells or HIV itself. This review will focus on HIV-associated phenotypic and functional alterations in memory B cells. Additionally, we will discuss the mechanism underlying these perturbations and the effect of anti-retroviral therapy (ART) on these perturbations. PMID:25887082

  4. Effect of Prunetin on TNF-?-Induced MUC5AC Mucin Gene Expression, Production, Degradation of I?B and Translocation of NF-?B p65 in Human Airway Epithelial Cells

    PubMed Central

    Ryu, Jiho; Lee, Hyun Jae; Park, Su Hyun; Sikder, Md. Asaduzzaman; Kim, Ju-Ock; Hong, Jang-Hee; Seok, Jeong Ho

    2013-01-01

    Background We investigated whether prunetin significantly affects tumor necrosis factor-? (TNF-?)-induced MUC5AC mucin gene expression, production, inhibitory kappa B (I?B) degradation and nuclear factor kappa B (NF-?B) p65 translocation in human airway epithelial cells. Methods Confluent NCI-H292 cells were pretreated with prunetin for 30 minutes and then stimulated with TNF-? for 24 hours or the indicated periods. MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The effect of prunetin on TNF-?-induced degradation of I?B and translocation of NF-?B p65 was investigated by western blot analysis. Results We found that incubation of NCI-H292 cells with prunetin significantly inhibited mucin production and down-regulated the MUC5AC gene expression induced by TNF-?. Prunetin inhibited TNF-?-induced degradation of I?B and translocation of NF-?B p65. Conclusion This result suggests that prunetin inhibits the NF-?B signaling pathway, which may explain its role in the inhibition of MUC5AC mucin gene expression and production regulated by the NF-?B signaling pathway. PMID:24348668

  5. Translocation of DNA across bacterial membranes.

    PubMed Central

    Dreiseikelmann, B

    1994-01-01

    DNA translocation across bacterial membranes occurs during the biological processes of infection by bacteriophages, conjugative DNA transfer of plasmids, T-DNA transfer, and genetic transformation. The mechanism of DNA translocation in these systems is not fully understood, but during the last few years extensive data about genes and gene products involved in the translocation processes have accumulated. One reason for the increasing interest in this topic is the discussion about horizontal gene transfer and transkingdom sex. Analyses of genes and gene products involved in DNA transfer suggest that DNA is transferred through a protein channel spanning the bacterial envelope. No common model exists for DNA translocation during phage infection. Perhaps various mechanisms are necessary as a result of the different morphologies of bacteriophages. The DNA translocation processes during conjugation, T-DNA transfer, and transformation are more consistent and may even be compared to the excretion of some proteins. On the basis of analogies and homologies between the proteins involved in DNA translocation and protein secretion, a common basic model for these processes is presented. PMID:7968916

  6. AID-associated DNA repair pathways regulate malignant transformation in a murine model of BCL6-driven diffuse large B-cell lymphoma.

    PubMed

    Gu, Xiwen; Booth, Carmen J; Liu, Zongzhi; Strout, Matthew P

    2016-01-01

    Somatic hypermutation and class-switch recombination of the immunoglobulin (Ig) genes occur in germinal center (GC) B cells and are initiated through deamination of cytidine to uracil by activation-induced cytidine deaminase (AID). Resulting uracil-guanine mismatches are processed by uracil DNA glycosylase (UNG)-mediated base-excision repair and MSH2-mediated mismatch repair (MMR) to yield mutations and DNA strand lesions. Although off-target AID activity also contributes to oncogenic point mutations and chromosome translocations associated with GC and post-GC B-cell lymphomas, the role of downstream AID-associated DNA repair pathways in the pathogenesis of lymphoma is unknown. Here, we show that simultaneous deficiency of UNG and MSH2 or MSH2 alone causes genomic instability and a shorter latency to the development of BCL6-driven diffuse large B-cell lymphoma (DLBCL) in a murine model. The additional development of several BCL6-independent malignancies in these mice underscores the critical role of MMR in maintaining general genomic stability. In contrast, absence of UNG alone is highly protective and prevents the development of BCL6-driven DLBCL. We further demonstrate that clonal and nonclonal mutations arise within non-Ig AID target genes in the combined absence of UNG and MSH2 and that DNA strand lesions arise in an UNG-dependent manner but are offset by MSH2. These findings lend insight into a complex interplay whereby potentially deleterious UNG activity and general genomic instability are opposed by the protective influence of MSH2, producing a net protective effect that promotes immune diversification while simultaneously attenuating malignant transformation of GC B cells. PMID:26385350

  7. A DNA-binding factor specific for xenobiotic responsive elements of P-450c gene exists as a cryptic form in cytoplasm: Its possible translocation to nucleus

    SciTech Connect

    Fujisawa-Sehara, Atsuko; Yamane, Miyuki; Fujii-Kuriyama, Yoshiaki

    1988-08-01

    Transcription of the drug-metabolizing cytochrome P-450c gene is induced by 3-methylcholanthrene or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Previously, the authors defined two xenobiotic responsive elements (XREs) of {approx}15 base pairs, both of which activate transcription in cis in response to these xenobiotics. Using a gel mobility shift assay, they have identified a factor that specifically binds to the XREs. This factor appears in nuclei of mouse hepatoma cell line Hepa-1 only when the cells are treated with the xenobiotics, while the factor is undetectable in the nuclei of a 3-methylcholanthrene-treated mutant of Hepa-1 with defective function of a xenobiotic receptor. In addition, the nuclear factor bound to the XRE in the gel was found to be associated with ({sup 3}H)TCDD when the cells were treated with it, suggesting that the xenobiotic receptor is at least a component of the DNA-binding factor. The cytoplasmic fraction from nontreated Hepa-1 cells also contains the factor as a cryptic form and prominently reveals its DNA-binding activity by incubation with 3-methylcholanthrene in vitro. These results not only suggest the involvement of the XRE-binding factor in transcriptional activation via XREs but also provide evidence that the binding of ligands to the preexisting factor in a cryptic form induces its XRE-binding activity, which is probably followed by its translocation from cytoplasm to nucleus.

  8. A new 17p13.3 microduplication including the PAFAH1B1 and YWHAE genes resulting from an unbalanced X;17 translocation.

    PubMed

    Hyon, Capucine; Marlin, Sandrine; Chantot-Bastaraud, Sandra; Mabboux, Philippe; Beaujard, Marie-Paule; Al Ageeli, Essam; Vazquez, Marie-Paule; Picard, Arnaud; Siffroi, Jean-Pierre; Portnoï, Marie-France

    2011-01-01

    Submicroscopic duplications of the genomic interval deleted in Miller-Dieker syndrome (MDS) were recently identified by array-based comparative genomic hybridization (a-CGH) studies, describing new genomic disorders in the MDS locus. These rearrangements of varying size, from 59-88 kb to 4 Mb, were non-recurrent, and appear to result from diverse molecular mechanisms. Only five patients had overlapping 17p13.3 duplications including the entire MDS critical region. We describe here a 13-year-old girl with a novel microduplication of the MDS critical region, involving the PAFAH1B1 and YWHAE genes. She presented with moderate psychomotor retardation, speech delay, behavioral problems, and bilateral cleft lip and palate, a previously unreported manifestation. Initially diagnosed as having an apparently simple terminal Xq26 deletion on standard cytogenetic analysis, she was found to have an associated terminal 4.2 Mb 17p13.3 submicroscopic duplication, identified by subtelomere FISH analysis, further characterized by high-resolution array CGH, resulting from an unbalanced X;17 translocation. Phenotypic comparison with the 5 other patients previously described, revealed common phenotypic features, such as hypotonia, mild to moderate developmental delay/mental retardation, speech abnormalities, behavioral problems, recurrent infections, relatively increase of body weight, discrete facial dysmorphism including downslanting palpebral fissures, broad midface, pointed chin, contributing to further delineate this new 17p13.3 microduplication syndrome. PMID:21195811

  9. Germinal center reentries of BCL2-overexpressing B cells drive follicular lymphoma progression

    PubMed Central

    Sungalee, Stéphanie; Mamessier, Emilie; Morgado, Ester; Grégoire, Emilie; Brohawn, Philip Z.; Morehouse, Christopher A.; Jouve, Nathalie; Monvoisin, Céline; Menard, Cédric; Debroas, Guilhaume; Faroudi, Mustapha; Mechin, Violaine; Navarro, Jean-Marc; Drevet, Charlotte; Eberle, Franziska C.; Chasson, Lionel; Baudimont, Fannie; Mancini, Stéphane J.; Tellier, Julie; Picquenot, Jean-Michel; Kelly, Rachel; Vineis, Paolo; Ruminy, Philippe; Chetaille, Bruno; Jaffe, Elaine S.; Schiff, Claudine; Hardwigsen, Jean; Tice, David A.; Higgs, Brandon W.; Tarte, Karin; Nadel, Bertrand; Roulland, Sandrine

    2014-01-01

    It has recently been demonstrated that memory B cells can reenter and reengage germinal center (GC) reactions, opening the possibility that multi-hit lymphomagenesis gradually occurs throughout life during successive immunological challenges. Here, we investigated this scenario in follicular lymphoma (FL), an indolent GC-derived malignancy. We developed a mouse model that recapitulates the FL hallmark t(14;18) translocation, which results in constitutive activation of antiapoptotic protein B cell lymphoma 2 (BCL2) in a subset of B cells, and applied a combination of molecular and immunofluorescence approaches to track normal and t(14;18)+ memory B cells in human and BCL2-overexpressing B cells in murine lymphoid tissues. BCL2-overexpressing B cells required multiple GC transits before acquiring FL-associated developmental arrest and presenting as GC B cells with constitutive activation–induced cytidine deaminase (AID) mutator activity. Moreover, multiple reentries into the GC were necessary for the progression to advanced precursor stages of FL. Together, our results demonstrate that protracted subversion of immune dynamics contributes to early dissemination and progression of t(14;18)+ precursors and shapes the systemic presentation of FL patients. PMID:25384217

  10. Germinal center reentries of BCL2-overexpressing B cells drive follicular lymphoma progression.

    PubMed

    Sungalee, Stéphanie; Mamessier, Emilie; Morgado, Ester; Grégoire, Emilie; Brohawn, Philip Z; Morehouse, Christopher A; Jouve, Nathalie; Monvoisin, Céline; Menard, Cédric; Debroas, Guilhaume; Faroudi, Mustapha; Mechin, Violaine; Navarro, Jean-Marc; Drevet, Charlotte; Eberle, Franziska C; Chasson, Lionel; Baudimont, Fannie; Mancini, Stéphane J; Tellier, Julie; Picquenot, Jean-Michel; Kelly, Rachel; Vineis, Paolo; Ruminy, Philippe; Chetaille, Bruno; Jaffe, Elaine S; Schiff, Claudine; Hardwigsen, Jean; Tice, David A; Higgs, Brandon W; Tarte, Karin; Nadel, Bertrand; Roulland, Sandrine

    2014-12-01

    It has recently been demonstrated that memory B cells can reenter and reengage germinal center (GC) reactions, opening the possibility that multi-hit lymphomagenesis gradually occurs throughout life during successive immunological challenges. Here, we investigated this scenario in follicular lymphoma (FL), an indolent GC-derived malignancy. We developed a mouse model that recapitulates the FL hallmark t(14;18) translocation, which results in constitutive activation of antiapoptotic protein B cell lymphoma 2 (BCL2) in a subset of B cells, and applied a combination of molecular and immunofluorescence approaches to track normal and t(14;18)(+) memory B cells in human and BCL2-overexpressing B cells in murine lymphoid tissues. BCL2-overexpressing B cells required multiple GC transits before acquiring FL-associated developmental arrest and presenting as GC B cells with constitutive activation-induced cytidine deaminase (AID) mutator activity. Moreover, multiple reentries into the GC were necessary for the progression to advanced precursor stages of FL. Together, our results demonstrate that protracted subversion of immune dynamics contributes to early dissemination and progression of t(14;18)(+) precursors and shapes the systemic presentation of FL patients. PMID:25384217

  11. Inferring processes underlying B-cell repertoire diversity

    PubMed Central

    Elhanati, Yuval; Sethna, Zachary; Marcou, Quentin; Callan, Curtis G.; Mora, Thierry; Walczak, Aleksandra M.

    2015-01-01

    We quantify the VDJ recombination and somatic hypermutation processes in human B cells using probabilistic inference methods on high-throughput DNA sequence repertoires of human B-cell receptor heavy chains. Our analysis captures the statistical properties of the naive repertoire, first after its initial generation via VDJ recombination and then after selection for functionality. We also infer statistical properties of the somatic hypermutation machinery (exclusive of subsequent effects of selection). Our main results are the following: the B-cell repertoire is substantially more diverse than T-cell repertoires, owing to longer junctional insertions; sequences that pass initial selection are distinguished by having a higher probability of being generated in a VDJ recombination event; somatic hypermutations have a non-uniform distribution along the V gene that is well explained by an independent site model for the sequence context around the hypermutation site. PMID:26194757

  12. B cell tolerance--how to make it and how to break it.

    PubMed

    Melchers, F; Rolink, A R

    2006-01-01

    A series of checkpoints for antigen receptor fitness and specificity during B cell development ensures the elimination or anergy of primary, high-avidity-autoantigen-reactive B cells. Defects in genes encoding molecules with which this purging of the original B cell repertoires is achieved may break this B cell tolerance, allowing the development of B cell- and autoantibody-mediated immune diseases. Furthermore, whenever tolerance of helper T cells to a part of an autoantigen is broken, a T cell-dependent germinal center-type response of the remaining low--or no--autoreactive B cells is activated. It induces longevity of these B cells, and expression of AiD, which effects Ig class switching and IgV-region hypermutation. The development of V-region-mutant B cells and the selections of high-avidity-autoantigen-reactive antibodies producing B cells by autoantigens from them, again, can lead to the development and propagation of autoimmune diseases such as lupus erythematosus or chronic inflammatory rheumatoid arthritis by the autoantibody BcR-expressing B cells and their secreted autoantibodies. PMID:16724798

  13. Mechanisms of action of BCL6 during germinal center B cell development.

    PubMed

    Huang, ChuanXin; Melnick, Ari

    2015-12-01

    The transcriptional repressor B cell lymphoma 6 (BCL6) controls a large transcriptional network that is required for the formation and maintenance of germinal centers (GC). GC B cells represent the normal counterpart of most human B-cell lymphomas, which are often characterized by deregulated BCL6 expression or BCL6-mediated pathways. BCL6 suppresses gene transcription largely through recruitment of its co-repressors through its distinct repression domain. Understanding the precise biological roles of each repression domain in normal and malignant B cells is helpful for development of targeted inhibition of BCL6 functions that is emerging as the basis for design of anti-lymphoma therapies. This review focuses on recent progress in the molecular mechanisms of action of BCL6 in B cells and discusses remaining unresolved questions related to how these mechanisms are linked to normal and malignant B cell development. PMID:26566802

  14. Nbs1 ChIP-Seq Identifies Off-Target DNA Double-Strand Breaks Induced by AID in Activated Splenic B Cells

    PubMed Central

    Linehan, Erin K.; Schrader, Carol E.; Stavnezer, Janet

    2015-01-01

    Activation-induced cytidine deaminase (AID) is required for initiation of Ig class switch recombination (CSR) and somatic hypermutation (SHM) of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs) involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP) for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq). We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID. PMID:26263206

  15. Memory B cells in mouse models.

    PubMed

    Bergmann, B; Grimsholm, O; Thorarinsdottir, K; Ren, W; Jirholt, P; Gjertsson, I; Mårtensson, I-L

    2013-08-01

    One of the principles behind vaccination, as shown by Edward Jenner in 1796, and host protection is immunological memory, and one of the cells central to this is the antigen-experienced memory B cell that responds rapidly upon re-exposure to the initiating antigen. Classically, memory B cells have been defined as progenies of germinal centre (GC) B cells expressing isotype-switched and substantially mutated B cell receptors (BCRs), that is, membrane-bound antibodies. However, it has become apparent over the last decade that this is not the only pathway to B cell memory. Here, we will discuss memory B cells in mice, as defined by (1) cell surface markers; (2) multiple layers; (3) formation in a T cell-dependent and either GC-dependent or GC-independent manner; (4) formation in a T cell-independent fashion. Lastly, we will touch upon memory B cells in; (5) mouse models of autoimmune diseases. PMID:23679222

  16. Rationale for B cell targeting in SLE

    PubMed Central

    Sanz, Iñaki

    2014-01-01

    B cells are central pathogenic players in Systemic Lupus Erythematosus and multiple other autoinmune diseases through antibody production as well as antibody independent functiona. At the same time, B cells are known to play important regulatory functions that may protect against autoimmune manifestations. Yet, the functional role of different B cell populations and their contribution to disease remain to be understood. The advent of agents that specifically target B cells, in particular anti-CD20 and ant-BLyS antibodies, have demonstrated the efficacy of this approach for the treatment of human autoimmunity. The analysis of patients treated with these and other B cell agents provide a unique opportunity to understand the correlates of clinical response and the significance of different B cell subsets. Here we discuss this information and how it could be used to better understand SLE and improve the rational design of B cell directed therapies in this disease. PMID:24763533

  17. Rap1b Regulates B Cell Development, Homing, and T Cell-Dependent Humoral Immunity1

    PubMed Central

    Chu, Haiyan; Awasthi, Aradhana; White, Gilbert C.; Chrzanowska-Wodnicka, Magdalena; Malarkannan, Subramaniam

    2015-01-01

    Rap1 is a small GTPase that belongs to Ras superfamily. This ubiquitously expressed GTPase is a key regulator of integrin functions. Rap1 exists in two isoforms: Rap1a and Rap1b. Although Rap1 has been extensively studied, its isoform-specific functions in B cells have not been elucidated. In this study, using gene knockout mice, we show that Rap1b is the dominant isoform in B cells. Lack of Rap1b significantly reduced the absolute number of B220+IgM? pro/pre-B cells and B220+IgM+ immature B cells in bone marrow. In vitro culture of bone marrow-derived Rap1b?/? pro/pre-B cells with IL-7 showed similar proliferation levels but reduced adhesion to stromal cell line compared with wild type. Rap1b?/? mice displayed reduced splenic marginal zone (MZ) B cells, and increased newly forming B cells, whereas the number of follicular B cells was normal. Functionally, Rap1b?/? mice showed reduced T-dependent but normal T-independent humoral responses. B cells from Rap1b?/? mice showed reduced migration to SDF-1, CXCL13 and in vivo homing to lymph nodes. MZ B cells showed reduced sphingosine-1-phosphate-induced migration and adhesion to ICAM-1. However, absence of Rap1b did not affect splenic B cell proliferation, BCR-mediated activation of Erk1/2, p38 MAPKs, and AKT. Thus, Rap1b is crucial for early B cell development, MZ B cell homeostasis and T-dependent humoral immunity. PMID:18714009

  18. Brg1 activates enhancer repertoires to establish B cell identity and modulate cell growth

    PubMed Central

    Bossen, Claudia; Murre, Caroline S; Chang, Aaron N; Mansson, Robert; Rodewald, Hans-Reimer; Murre, Cornelis

    2015-01-01

    Early B cell development is orchestrated by the combined activities of the transcriptional regulators E2A, EBF1, Foxo1 and Ikaros. However, how the genome-wide binding patterns of these regulators are modulated during B-lineage development remains to be determined. Here, we found that in lymphoid progenitors the chromatin remodeler Brg1 specified the B cell fate. In committed pro-B cells Brg1 regulated Igh locus contraction and controlled Myc expression to modulate the expression of genes that regulate ribosome biogenesis. In committed pro-B cells Brg1 suppressed a pre-B lineage-specific pattern of gene expression. Finally, we found that Brg1 acted mechanistically to establish B cell fate and modulate cell growth by facilitating access of lineage-specific transcription factors to poised enhancer repertoires. PMID:25985234

  19. DNA Methylation Dynamics of Germinal Center B Cells Are Mediated by AID.

    PubMed

    Dominguez, Pilar M; Teater, Matt; Chambwe, Nyasha; Kormaksson, Matthias; Redmond, David; Ishii, Jennifer; Vuong, Bao; Chaudhuri, Jayanta; Melnick, Ari; Vasanthakumar, Aparna; Godley, Lucy A; Papavasiliou, F Nina; Elemento, Olivier; Shaknovich, Rita

    2015-09-29

    Changes in DNA methylation are required for the formation of germinal centers (GCs), but the mechanisms of such changes are poorly understood. Activation-induced cytidine deaminase (AID) has been recently implicated in DNA demethylation through its deaminase activity coupled with DNA repair. We investigated the epigenetic function of AID in vivo in germinal center B cells (GCBs) isolated from wild-type (WT) and AID-deficient (Aicda(-/-)) mice. We determined that the transit of B cells through the GC is associated with marked locus-specific loss of methylation and increased methylation diversity, both of which are lost in Aicda(-/-) animals. Differentially methylated cytosines (DMCs) between GCBs and naive B cells (NBs) are enriched in genes that are targeted for somatic hypermutation (SHM) by AID, and these genes form networks required for B cell development and proliferation. Finally, we observed significant conservation of AID-dependent epigenetic reprogramming between mouse and human B cells. PMID:26365193

  20. Genomes of Ashbya Fungi Isolated from Insects Reveal Four Mating-Type Loci, Numerous Translocations, Lack of Transposons, and Distinct Gene Duplications

    PubMed Central

    Dietrich, Fred S.; Voegeli, Sylvia; Kuo, Sidney; Philippsen, Peter

    2013-01-01

    The filamentous fungus Ashbya gossypii is a cotton pathogen transmitted by insects. It is readily grown and manipulated in the laboratory and is commercially exploited as a natural overproducer of vitamin B2. Our previous genome analysis of A. gossypii isolate ATCC10895, collected in Trinidad nearly 100 years ago, revealed extensive synteny with the Saccharomyces cerevisiae genome, leading us to use it as a model organism to understand the evolution of filamentous growth. To further develop Ashbya as a model system, we have investigated the ecological niche of A. gossypii and isolated additional strains and a sibling species, both useful in comparative analysis. We isolated fungi morphologically similar to A. gossypii from different plant-feeding insects of the suborder Heteroptera, generated a phylogenetic tree based on rDNA-ITS sequences, and performed high coverage short read sequencing with one A. gossypii isolate from Florida, a new species, Ashbya aceri, isolated in North Carolina, and a genetically marked derivative of ATCC10895 intensively used for functional studies. In contrast to S. cerevisiae, all strains carry four not three mating type loci, adding a new puzzle in the evolution of Ashbya species. Another surprise was the genome identity of 99.9% between the Florida strain and ATCC10895, isolated in Trinidad. The A. aceri and A. gossypii genomes show conserved gene orders rearranged by eight translocations, 90% overall sequence identity, and fewer tandem duplications in the A. aceri genome. Both species lack transposable elements. Finally, our work identifies plant-feeding insects of the suborder Heteroptera as the most likely natural reservoir of Ashbya, and that infection of cotton and other plants may be incidental to the growth of the fungus in its insect host. PMID:23749448

  1. Dynamic Contrast-Enhanced CT Characterization of Xp11.2 Translocation/TFE3 Gene Fusions versus Papillary Renal Cell Carcinomas

    PubMed Central

    He, Jian; Zhou, Kefeng; Zhu, Bin; Zhang, Gutian; Li, Xiaogong; Guo, Hongqian; Gan, Weidong; Zhou, Zhengyang; Liu, Tian

    2015-01-01

    Purpose. To compare the differences of CT characteristics between renal cell carcinomas (RCCs) associated with Xp11.2 translocation/TFE3 gene fusions (Xp11.2 RCCs) and papillary cell renal cell carcinomas (PRCCs). Methods. CT images and clinical records of 64 patients (25 Xp11.2 RCCs, 15 type 1 and 24 type 2 PRCCs) were analyzed and compared retrospectively. Results. Xp11.2 RCC more frequently affected young (30.7 ± 8.7 years) women (16/25, 64%) with gross hematuria (12/25, 48%), while PRCC more frequently involved middle-aged (54.8 ± 11.1 years) men (28/39, 71.8%) asymptomatically. Xp11.2 RCC tended to be heterogeneous density with some showing circular calcification. Lesion sizes of Xp11.2 RCC (5.4 ± 2.2?cm) and type 2 PRCC (5.7 ± 2.5?cm) were significantly larger than that of type 1 PRCC (3.8 ± 1.8?cm). Xp11.2 RCC contained more cystic components (22/25, 88%) than type 1 PRCC (all solid) and type 2 PRCC (9/24, 36.0%). Type 1 PRCC (13/15, 86.7%) and Xp11.2 RCC (21/25, 84.0%) showed more clear boundary than type 2 PRCC (12/24, 50.0%). Conclusion. CT features including diameter, boundary, attenuation, nature, and circular calcification of the tumor, combined with demographic information and symptoms, may be useful to differentiate Xp11.2 RCC from different subtypes of PRCC. PMID:26636097

  2. Early B-cell-specific inactivation of ATM synergizes with ectopic CyclinD1 expression to promote pre-germinal center B-cell lymphomas in mice.

    PubMed

    Yamamoto, K; Lee, B J; Li, C; Dubois, R L; Hobeika, E; Bhagat, G; Zha, S

    2015-06-01

    Ataxia telangiectasia-mutated (ATM) kinase is a master regulator of the DNA damage response. ATM is frequently inactivated in human B-cell non-Hodgkin lymphomas, including ~50% of mantle cell lymphomas (MCLs) characterized by ectopic expression of CyclinD1. Here we report that early and robust deletion of ATM in precursor/progenitor B cells causes cell autonomous, clonal mature B-cell lymphomas of both pre- and post-germinal center (GC) origins. Unexpectedly, naive B-cell-specific deletion of ATM is not sufficient to induce lymphomas in mice, highlighting the important tumor suppressor function of ATM in immature B cells. Although E?CyclinD1 is not sufficient to induce lymphomas, E?CyclinD1 accelerates the kinetics and increases the incidence of clonal lymphomas in ATM-deficient B-cells and skews the lymphomas toward pre-GC-derived small lymphocytic neoplasms, sharing morphological features of human MCL. This is in part due to CyclinD1-driven expansion of ATM-deficient naive B cells with genomic instability, which promotes the deletions of additional tumor suppressor genes (i.e. Trp53, Mll2, Rb1 and Cdkn2a). Together these findings define a synergistic function of ATM and CyclinD1 in pre-GC B-cell proliferation and lymphomagenesis and provide a prototypic animal model to study the pathogenesis of human MCL. PMID:25676421

  3. Neurotrophins and B-cell malignancies.

    PubMed

    Hillis, Jennifer; O'Dwyer, Michael; Gorman, Adrienne M

    2016-01-01

    Neurotrophins and their receptors act as important proliferative and pro-survival factors in a variety of cell types. Neurotrophins are produced by multiple cell types in both pro- and mature forms, and can act in an autocrine or paracrine fashion. The p75(NTR) and Trk receptors can elicit signalling in response to the presence or absence of their corresponding neurotrophin ligands. This signalling, along with neurotrophin and receptor expression, varies between different cell types. Neurotrophins and their receptors have been shown to be expressed by and elicit signalling in B lymphocytes. In general, most neurotrophins are expressed by activated B-cells and memory B-cells. Likewise, the TrkB95 receptor is seen on activated B-cells, while TrkA and p75(NTR) are expressed by both resting and active B-cells as well as memory B-cells. Nerve growth factor stimulates B-cell proliferation, memory B-cell survival, antibody production and CD40 expression. Brain-derived neurotrophic factor is involved in B-cell maturation in the bone marrow through TrkB95. Overall neurotrophins and their receptors have been shown to be involved in B-cell proliferation, development, differentiation, antibody secretion and survival. As well as expression and activity in healthy B-cells, the neurotrophins and their receptors can contribute to B-cell malignancies including acute lymphoblastic leukaemia, diffuse large B-cell lymphoma, Burkitt's lymphoma and multiple myeloma. They are involved in B-cell malignancy survival and potentially in drug resistance. PMID:26399960

  4. B cell–intrinsic deficiency of the Wiskott-Aldrich syndrome protein (WASp) causes severe abnormalities of the peripheral B-cell compartment in mice

    PubMed Central

    Recher, Mike; Burns, Siobhan O.; de la Fuente, Miguel A.; Volpi, Stefano; Dahlberg, Carin; Walter, Jolan E.; Moffitt, Kristin; Mathew, Divij; Honke, Nadine; Lang, Philipp A.; Patrizi, Laura; Falet, Hervé; Keszei, Marton; Mizui, Masayuki; Csizmadia, Eva; Candotti, Fabio; Nadeau, Kari; Bouma, Gerben; Delmonte, Ottavia M.; Frugoni, Francesco; Fomin, Angela B. Ferraz; Buchbinder, David; Lundequist, Emma Maria; Massaad, Michel J.; Tsokos, George C.; Hartwig, John; Manis, John; Terhorst, Cox; Geha, Raif S.; Snapper, Scott; Lang, Karl S.; Malley, Richard; Westerberg, Lisa

    2012-01-01

    Wiskott Aldrich syndrome (WAS) is caused by mutations in the WAS gene that encodes for a protein (WASp) involved in cytoskeleton organization in hematopoietic cells. Several distinctive abnormalities of T, B, and natural killer lymphocytes; dendritic cells; and phagocytes have been found in WASp-deficient patients and mice; however, the in vivo consequence of WASp deficiency within individual blood cell lineages has not been definitively evaluated. By conditional gene deletion we have generated mice with selective deficiency of WASp in the B-cell lineage (B/WcKO mice). We show that this is sufficient to cause a severe reduction of marginal zone B cells and inability to respond to type II T-independent Ags, thereby recapitulating phenotypic features of complete WASp deficiency. In addition, B/WcKO mice showed prominent signs of B-cell dysregulation, as indicated by an increase in serum IgM levels, expansion of germinal center B cells and plasma cells, and elevated autoantibody production. These findings are accompanied by hyperproliferation of WASp-deficient follicular and germinal center B cells in heterozygous B/WcKO mice in vivo and excessive differentiation of WASp-deficient B cells into class-switched plasmablasts in vitro, suggesting that WASp-dependent B cell–intrinsic mechanisms critically contribute to WAS-associated autoimmunity. PMID:22302739

  5. B cell-intrinsic deficiency of the Wiskott-Aldrich syndrome protein (WASp) causes severe abnormalities of the peripheral B-cell compartment in mice.

    PubMed

    Recher, Mike; Burns, Siobhan O; de la Fuente, Miguel A; Volpi, Stefano; Dahlberg, Carin; Walter, Jolan E; Moffitt, Kristin; Mathew, Divij; Honke, Nadine; Lang, Philipp A; Patrizi, Laura; Falet, Hervé; Keszei, Marton; Mizui, Masayuki; Csizmadia, Eva; Candotti, Fabio; Nadeau, Kari; Bouma, Gerben; Delmonte, Ottavia M; Frugoni, Francesco; Fomin, Angela B Ferraz; Buchbinder, David; Lundequist, Emma Maria; Massaad, Michel J; Tsokos, George C; Hartwig, John; Manis, John; Terhorst, Cox; Geha, Raif S; Snapper, Scott; Lang, Karl S; Malley, Richard; Westerberg, Lisa; Thrasher, Adrian J; Notarangelo, Luigi D

    2012-03-22

    Wiskott Aldrich syndrome (WAS) is caused by mutations in the WAS gene that encodes for a protein (WASp) involved in cytoskeleton organization in hematopoietic cells. Several distinctive abnormalities of T, B, and natural killer lymphocytes; dendritic cells; and phagocytes have been found in WASp-deficient patients and mice; however, the in vivo consequence of WASp deficiency within individual blood cell lineages has not been definitively evaluated. By conditional gene deletion we have generated mice with selective deficiency of WASp in the B-cell lineage (B/WcKO mice). We show that this is sufficient to cause a severe reduction of marginal zone B cells and inability to respond to type II T-independent Ags, thereby recapitulating phenotypic features of complete WASp deficiency. In addition, B/WcKO mice showed prominent signs of B-cell dysregulation, as indicated by an increase in serum IgM levels, expansion of germinal center B cells and plasma cells, and elevated autoantibody production. These findings are accompanied by hyperproliferation of WASp-deficient follicular and germinal center B cells in heterozygous B/WcKO mice in vivo and excessive differentiation of WASp-deficient B cells into class-switched plasmablasts in vitro, suggesting that WASp-dependent B cell-intrinsic mechanisms critically contribute to WAS-associated autoimmunity. PMID:22302739

  6. Discovery and molecular mapping of a new gene conferring resistance to stem rust, Sr53, derived from Aegilops geniculata and characterization of spontaneous translocation stocks with reduced alien chromatin.

    PubMed

    Liu, Wenxuan; Rouse, Matthew; Friebe, Bernd; Jin, Yue; Gill, Bikram; Pumphrey, Michael O

    2011-07-01

    This study reports the discovery and molecular mapping of a resistance gene effective against stem rust races RKQQC and TTKSK (Ug99) derived from Aegilops geniculata (2n?=?4x?=?28, U(g)U(g)M(g)M(g)). Two populations from the crosses TA5599 (T5DL-5M(g)L·5M(g)S)/TA3809 (ph1b mutant in Chinese Spring background) and TA5599/Lakin were developed and used for genetic mapping to identify markers linked to the resistance gene. Further molecular and cytogenetic characterization resulted in the identification of nine spontaneous recombinants with shortened Ae. geniculata segments. Three of the wheat-Ae. geniculata recombinants (U6154-124, U6154-128, and U6200-113) are interstitial translocations (T5DS·5DL-5M(g)L-5DL), with 20-30% proximal segments of 5M(g)L translocated to 5DL; the other six are recombinants (T5DL-5M(g)L·5M(g)S) have shortened segments of 5M(g)L with fraction lengths (FL) of 0.32-0.45 compared with FL 0.55 for the 5M(g)L segment in the original translocation donor, TA5599. Recombinants U6200-64, U6200-117, and U6154-124 carry the stem rust resistance gene Sr53 with the same infection type as TA5599, the resistance gene donor. All recombinants were confirmed to be genetically compensating on the basis of genomic in situ hybridization and molecular marker analysis with chromosome 5D- and 5M(g)-specific SSR/STS-PCR markers. These recombinants between wheat and Ae. geniculata will provide another source for wheat stem rust resistance breeding and for physical mapping of the resistance locus and crossover hot spots between wheat chromosome 5D and chromosome 5M(g)L of Ae. geniculata. PMID:21728140

  7. PI3K Signaling in Normal B Cells and Chronic Lymphocytic Leukemia (CLL)

    PubMed Central

    Okkenhaug, Klaus; Burger, Jan A.

    2016-01-01

    B cells provide immunity to extracellular pathogens by secreting a diverse repertoire of antibodies with high affinity and specificity for exposed antigens. The B cell receptor (BCR) is a transmembrane antibody, which facilitates the clonal selection of B cells producing secreted antibodies of the same specificity. The diverse antibody repertoire is generated by V(D)J recombination of heavy and light chain genes, whereas affinity maturation is mediated by activation-induced cytidine deaminase (AID)-mediated mutagenesis. These processes, which are essential for the generation of adaptive humoral immunity, also render B cells susceptible to chromosomal rearrangements and point mutations that in some cases lead to cancer. In this chapter, we will review the central role of PI3Ks in mediating signals from the B cell receptor that not only facilitate the development of functional B cell repertoire, but also support the growth and survival of neoplastic B cells, focusing on chronic lymphocytic leukemia (CLL) B cells. Perhaps because of the central role played by PI3K in BCR signaling, B cell leukemia and lymphomas are the first diseases for which a PI3K inhibitor has been approved for clinical use. PMID:26350103

  8. PI3K Signaling in Normal B Cells and Chronic Lymphocytic Leukemia (CLL).

    PubMed

    Okkenhaug, Klaus; Burger, Jan A

    2016-01-01

    B cells provide immunity to extracellular pathogens by secreting a diverse repertoire of antibodies with high affinity and specificity for exposed antigens. The B cell receptor (BCR ) is a transmembrane antibody, which facilitates the clonal selection of B cells producing secreted antibodies of the same specificity. The diverse antibody repertoire is generated by V(D)J recombination of heavy and light chain genes, whereas affinity maturation is mediated by activation-induced cytidine deaminase (AID)-mediated mutagenesis. These processes, which are essential for the generation of adaptive humoral immunity, also render B cells susceptible to chromosomal rearrangements and point mutations that in some cases lead to cancer. In this chapter, we will review the central role of PI3K s in mediating signals from the B cell receptor that not only facilitate the development of functional B cell repertoire, but also support the growth and survival of neoplastic B cells, focusing on chronic lymphocytic leukemia (CLL ) B cells. Perhaps because of the central role played by PI3K in BCR signaling, B cell leukemia and lymphomas are the first diseases for which a PI3K inhibitor has been approved for clinical use. PMID:26350103

  9. Clustered organization of Krueppel zinc-finger genes at Xp11. 23, flanking a translocation breakpoint at OATL1: A physical map with locus assignments for ZNF21, ZNF41, ZNF81, and ELK1

    SciTech Connect

    Knight, J.C.; Fletcher, C.D.M. ); Grimaldi, G. ); Thiesen, H.J. ); Bech-Hansen, N.T. ); Coleman, M.P. )

    1994-05-01

    The ZNF21, ZNF41, and ZNF81 genes encode Krueppel-type zinc-finger proteins (ZFPs) and have previously been mapped to chromosome Xp. Published data describing the clustering of ZFP genes on human autosomes led to investigation of the organization of ZNF21, ZNF41, and ZNF81 on the X chromosome. Rodent-human hybrid analysis sublocalized all three genes to Xp22.11-p11.23. ZNF21, ZNF41, and ZNF81 were then shown to segregate within a series of YACs (95 to 730 kb) containing known markers at Xp11.23, such that these YACs could be assembled into a contig spanning approximately 1.5 Mb of DNA. Southern analysis of intact YACs and YAC DNAs cut with rare-cutter restriction enzymes enabled establishment of the spatial organization of the ZFP gene cluster, the OATL1 pseudogene, the recurrent t(X;18) chromosome translocation breakpoint in synovial sarcoma, and the previously described cluster of ARAF1, SYN1, TIMP, and PFC genes. The authors have assigned the ETS-related gene ELK1 to a locus tightly linked to the PFC gene; the entire cluster of five genes is contained within a distance of 120 kb. ZNF41 maps to a 440-kb YAC spanning this region, while a more proximal cluster comprising the ZNF21 and ZNF81 gene lies 150 kb distal to the chromosome breakpoint associated with synovial sarcoma. 50 refs., 3 figs., 2 tabs.

  10. Proteomic Changes during B Cell Maturation: 2D-DIGE Approach

    PubMed Central

    Salonen, Johanna; Rönnholm, Gunilla; Kalkkinen, Nisse; Vihinen, Mauno

    2013-01-01

    B cells play a pivotal role in adaptive immune system, since they maintain a delicate balance between recognition and clearance of foreign pathogens and tolerance to self. During maturation, B cells progress through a series of developmental stages defined by specific phenotypic surface markers and the rearrangement and expression of immunoglobulin (Ig) genes. To get insight into B cell proteome during the maturation pathway, we studied differential protein expression in eight human cell lines, which cover four distinctive developmental stages; early pre-B, pre-B, plasma cell and immature B cell upon anti-IgM stimulation. Our two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry based proteomic study indicates the involvement of large number of proteins with various functions. Notably, proteins related to cytoskeleton were relatively highly expressed in early pre-B and pre-B cells, whereas plasma cell proteome contained endoplasmic reticulum and Golgi system proteins. Our long time series analysis in anti-IgM stimulated Ramos B cells revealed the dynamic regulation of cytoskeleton organization, gene expression and metabolic pathways, among others. The findings are related to cellular processes in B cells and are discussed in relation to experimental information for the proteins and pathways they are involved in. Representative 2D-DIGE maps of different B cell maturation stages are available online at http://structure.bmc.lu.se/BcellProteome/. PMID:24205016

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

    PubMed

    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

    2013-04-01

    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. PMID:23463102

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

    PubMed Central

    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

    2013-01-01

    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. PMID:23463102

  13. STAT3 Targets Suggest Mechanisms of Aggressive Tumorigenesis in Diffuse Large B-Cell Lymphoma

    PubMed Central

    Hardee, Jennifer; Ouyang, Zhengqing; Zhang, Yuping; Kundaje, Anshul; Lacroute, Philippe; Snyder, Michael

    2013-01-01

    The signal transducer and activator of transcription 3 (STAT3) is a transcription factor that, when dysregulated, becomes a powerful oncogene found in many human cancers, including diffuse large B-cell lymphoma. Diffuse large B-cell lymphoma is the most common form of non-Hodgkin’s lymphoma and has two major subtypes: germinal center B-cell?like and activated B–cell—like. Compared with the germinal center B-cell?like form, activated B-cell?like lymphomas respond much more poorly to current therapies and often exhibit overexpression or overactivation of STAT3. To investigate how STAT3 might contribute to this aggressive phenotype, we have integrated genome-wide studies of STAT3 DNA binding using chromatin immunoprecipitation-sequencing with whole-transcriptome profiling using RNA-sequencing. STAT3 binding sites are present near almost a third of all genes that differ in expression between the two subtypes, and examination of the affected genes identified previously undetected and clinically significant pathways downstream of STAT3 that drive oncogenesis. Novel treatments aimed at these pathways may increase the survivability of activated B-cell?like diffuse large B-cell lymphoma. PMID:24142927

  14. B-Cell Hematologic Malignancy Vaccination Registry

    ClinicalTrials.gov

    2015-09-15

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

  15. The expanding family of regulatory B cells

    PubMed Central

    Menon, Madhvi

    2015-01-01

    Over the last decade it has become evident that in addition to producing antibody, B cells activate the immune system by producing cytokines and via antigen presentation. In addition, B cells also exhibit immunosuppressive functions via diverse regulatory mechanisms. This subset of B cells, known as regulatory B cells (Bregs), contributes to the maintenance of tolerance, primarily via the production of IL-10. Studies in experimental animal models, as well as in patients with autoimmune diseases, have identified multiple Breg subsets exhibiting diverse mechanisms of immune suppression. In this review, we describe the different Breg subsets identified in mice and humans, and their diverse mechanisms of suppression in different disease settings. PMID:26071023

  16. B cell lymphoma and myeloma in murine Gaucher's disease.

    PubMed

    Pavlova, E V; Wang, S Z; Archer, J; Dekker, N; Aerts, J M F G; Karlsson, S; Cox, T M

    2013-09-01

    Multiple myeloma and B cell lymphoma are leading causes of death in Gaucher's disease but the nature of the stimulus driving the often noted clonal expansion of immunoglobulin-secreting B cells and cognate lymphoid malignancy is unknown. We investigated the long-term development of B cell malignancies in an authentic model of non-neuronopathic Gaucher's disease in mice: selective deficiency of ?-glucocerebrosidase in haematopoietic cells [Gba(tm1Karl/tm1Karl)Tg(Mx1-cre)1Cgn/0, with excision of exons 9-11 of the murine GBA1 gene, is induced by poly[I:C]. Mice with Gaucher's disease showed visceral storage of ?-glucosylceramide and greatly elevated plasma ?-glucosylsphingosine [median 57.9 (range 19.8-159) nm; n = 39] compared with control mice from the same strain [median 0.56 (range 0.04-1.38) nm; n = 29] (p < 0.0001). Sporadic fatal B cell lymphomas developed in 11 of 21 GD mice (6-24 months) but only two of eight control animals developed tumours by age 24 months. Unexpectedly, most mice with overt lymphoma had absent or few Gaucher cells but local inflammatory macrophages were present. Eleven of 39 of Gaucher mice developed monoclonal gammopathy, but in the control group only one animal of 25 had clonal immunoglobulin abnormalities. Seven of 10 of the B cell lymphomas were found to secrete a monoclonal paraprotein and the lymphomas stained intensely for pan-B cell markers; reactive T lymphocytes were also present in tumour tissue. In the Gaucher mouse strain, it was notable that, as in patients with this disease, CD138(+) plasma cells frequently surrounded splenic macrophages engorged with glycosphingolipid. Our strain of mice, with inducible deficiency of ?-glucocerebrosidase in haematopoietic cells and a high frequency of sporadic lethal B cell malignancies, faithfully recapitulates human Gaucher's disease: it serves as a tractable model to investigate the putative role of bioactive sphingolipids in the control of B cell proliferation and the pathogenesis of myelomatosis-the most prevalent human cancer associated with this disorder. PMID:23775597

  17. The TEL-AML1 fusion protein of acute lymphoblastic leukemia modulates IRF3 activity during early B-cell differentiation.

    PubMed

    de Laurentiis, A; Hiscott, J; Alcalay, M

    2015-12-01

    The t(12;21) translocation is the most common genetic rearrangement in childhood acute lymphoblastic leukemia (ALL) and gives rise to the TEL-AML1 fusion gene. Many studies on TEL-AML1 describe specific properties of the fusion protein, but a thorough understanding of its function is lacking. We exploited a pluripotent hematopoietic stem/progenitor cell line, EML1, and generated a cell line (EML-TA) stably expressing the TEL-AML1 fusion protein. EML1 cells differentiate to mature B-cells following treatment with IL7; whereas EML-TA display an impaired differentiation capacity and remain blocked at an early stage of maturation. Global gene expression profiling of EML1 cells at different stages of B-lymphoid differentiation, compared with EML-TA, identified the interferon (IFN)?/? pathway as a primary target of repression by TEL-AML1. In particular, expression and phosphorylation of interferon-regulatory factor 3 (IRF3) was decreased in EML-TA cells; strikingly, stable expression of IRF3 restored the capacity of EML-TA cells to differentiate into mature B-cells. Similarly, IRF3 silencing in EML1 cells by siRNA was sufficient to block B-lymphoid differentiation. The ability of TEL-AML1 to block B-cell differentiation and downregulate the IRF3-IFN?/? pathway was confirmed in mouse and human primary hematopoietic precursor cells (Lin- and CD34+ cells, respectively), and in a patient-derived cell line expressing TEL-AML1 (REH). Furthermore, treatment of TEL-AML1 expressing cells with IFN?/? was sufficient to overcome the maturation block. Our data provide new insight on TEL-AML1 function and may offer a new therapeutic opportunity for B-ALL. PMID:25893288

  18. Functional capacities of human IgM memory B cells in early inflammatory responses and secondary germinal center reactions

    PubMed Central

    Seifert, Marc; Przekopowitz, Martina; Taudien, Sarah; Lollies, Anna; Ronge, Viola; Drees, Britta; Lindemann, Monika; Hillen, Uwe; Engler, Harald; Singer, Bernhard B.; Küppers, Ralf

    2015-01-01

    The generation and functions of human peripheral blood (PB) IgM+IgD+CD27+ B lymphocytes with somatically mutated IgV genes are controversially discussed. We determined their differential gene expression to naive B cells and to IgM-only and IgG+ memory B cells. This analysis revealed a high similarity of IgM+(IgD+)CD27+ and IgG+ memory B cells but also pointed at distinct functional capacities of both subsets. In vitro analyses revealed a tendency of activated IgM+IgD+CD27+ B cells to migrate to B-cell follicles and undergo germinal center (GC) B-cell differentiation, whereas activated IgG+ memory B cells preferentially showed a plasma cell (PC) fate. This observation was supported by reverse regulation of B-cell lymphoma 6 and PR domain containing 1 and differential BTB and CNC homology 1, basic leucine zipper transcription factor 2 expression. Moreover, IgM+IgD+CD27+ B lymphocytes preferentially responded to neutrophil-derived cytokines. Costimulation with catecholamines, carcinoembryonic antigen cell adhesion molecule 8 (CEACAM8), and IFN-? caused differentiation of IgM+IgD+CD27+ B cells into PCs, induced class switching to IgG2, and was reproducible in cocultures with neutrophils. In conclusion, this study substantiates memory B-cell characteristics of human IgM+IgD+CD27+ B cells in that they share typical memory B-cell transcription patterns with IgG+ post-GC B cells and show a faster and more vigorous restimulation potential, a hallmark of immune memory. Moreover, this work reveals a functional plasticity of human IgM memory B cells by showing their propensity to undergo secondary GC reactions upon reactivation, but also by their special role in early inflammation via interaction with immunomodulatory neutrophils. PMID:25624468

  19. B cells generated by B-1 development can progress to chronic lymphocytic leukemia.

    PubMed

    Hayakawa, Kyoko; Formica, Anthony M; Colombo, Matthew J; Ichikawa, Daiju; Shinton, Susan A; Brill-Dashoff, Joni; Hardy, Richard R

    2015-12-01

    B cells generated early during fetal/neonatal B-1 development in mice include autoreactive cells with detectable CD5 upregulation induced by B cell receptor (BCR) signaling (B1a cells). A fraction of B1a cells are maintained by self-renewal for life, with the potential risk of dysregulated growth and progression to chronic lymphocytic leukemia (CLL)/lymphoma during aging. In studies using the E?-hTCL1 transgenic mouse system, it became clear that this B1a subset has a higher potential than other B cell subsets for progression to CLL. We have generated several autoreactive germline BCR gene models to compare B cells generated under conditions of natural exposure to autoantigen. Analysis of the mice has been key in understanding the importance of the BCR and BCR signaling for generating different B cell subsets and for investigating the cellular origin of B-CLL. PMID:25907284

  20. Plasmacytoid Dendritic Cells Mediate Synergistic Effects of HIV and Lipopolysaccharide on CD27+ IgD– Memory B Cell Apoptosis

    PubMed Central

    Zhang, Lumin; Luo, Zhenwu; Sieg, Scott F.; Funderburg, Nicholas T.; Yu, Xiaocong; Fu, Pingfu; Wu, Hao; Jiao, Yanmei; Gao, Yong; Greenspan, Neil S.; Harding, Clifford V.; Kilby, J. Michael; Li, Zihai; Lederman, Michael M.

    2014-01-01

    ABSTRACT The effects of heightened microbial translocation on B cells during HIV infection are unknown. We examined the in vitro effects of HIV and lipopolysaccharide (LPS) on apoptosis of CD27+ IgD? memory B (mB) cells from healthy controls. In vivo analysis was conducted on a cohort of 82 HIV+ donors and 60 healthy controls. In vitro exposure of peripheral blood mononuclear cells (PBMCs) to LPS and HIV led to mB cell death via the Fas/Fas ligand (FasL) pathway. Plasmacytoid dendritic cells (pDCs) produced FasL in response to HIV via binding to CD4 and chemokine coreceptors. HIV and LPS increased Fas expression on mB cells in PBMCs, which was dependent on the presence of pDCs and monocytes. Furthermore, mB cells purified from PBMCs and pretreated with both HIV and LPS were more sensitive to apoptosis when cocultured with HIV-treated pDCs. Blocking the interferon receptor (IFNR) prevented HIV-stimulated FasL production in pDCs, HIV-plus-LPS-induced Fas expression, and apoptosis of mB cells. In vivo or ex vivo, HIV+ donors have higher levels of plasma LPS, Fas expression on mB cells, and mB cell apoptosis than controls. Correspondingly, in HIV+ donors, but not in controls, a positive correlation was found between plasma FasL and HIV RNA levels and between Fas expression on mB cells and plasma LPS levels. This work reveals a novel mechanism of mB cell apoptosis mediated by LPS and HIV through the Fas/FasL pathway, with key involvement of pDCs and type I IFN, suggesting a role for microbial translocation in HIV pathogenesis. IMPORTANCE This study demonstrates that lipopolysaccharide (LPS) and type I interferon (IFN) play an important role in memory B cell apoptosis in HIV infection. It reveals a previously unrecognized role of microbial translocation in HIV pathogenesis. PMID:25056888

  1. A cosmid and cDNA ne physical map of a human chromosome 13q14 region frequently lost in B-cell chronic lymphocytic leukemia and

    E-print Network

    Baranova, Ancha

    -cell chronic lymphocytic leukemia and identi¢cation of a new putative tumor suppressor gene, Leu5 Bagrat Berlin, Germany Received 11 March 1998 Abstract B-cell chronic lymphocytic leukemia (B-CLL) is a human suppressor gene; Location; B-cell chronic lymphocytic leukemia; Zinc binding; Human 1. Introduction Genes

  2. Somatostatin Improved B Cells Mature in Macaques during Intestinal Ischemia-Reperfusion

    PubMed Central

    Liu, Ling; Tan, Qinghua; Hu, Bin; Wu, Hao; Wang, Chunhui; Liu, Rui; Tang, Chengwei

    2015-01-01

    Aims Intestinal ischemia-reperfusion has been taken as an important pathophysiological process for multiple organ dysfunctions in critical patients. Recent studies reported that dual expression programs of the B cells receptors and Toll-like receptors on B-lymphocytes permit these ubiquitous cells to integrate both adaptive and innate immune functions. Our previous studies found that somatostatin inhibited the intestinal inflammatory injury after ischemia-reperfusion in macaques. However, the changes of B cells and the effects of somatostatin on B cells after intestinal ischemia-reperfusion were unclear. Methods 15 macaques were divided into control, intestinal ischemia-reperfusion and somatostatin pretreatment groups. Immunohistochemistry was performed to identify the distributions of adaptive and innate immunity markers in the iliac mucosa. Hmy2.cir B lymphoblastoid cell line was cultured in vitro study. Enzyme-linked immunosorbent assay was used to measure IgM, IL-6 and SIgA, and the expressions of B cells transcription factors, PAX-5 and BLIMP-1, were detected by Western blotting. Results B2 lymphocytes in normal Peyer’s patches were presented the phenotype of PAX-5+CD20+CD5-. Ischemia-reperfusion increased the numbers and sizes of Peyer’s patches but with PAX-5+CD20-CD5- B cells, an unmatured set of B cells. Somatostatin partly kept the phenotype of mature B cells during ischemia-reperfusion. The innate immunity of B cells was inhibited whereas the adaptive immunity was increased in the intestinal mucosa in the somatostatin group, compared to the ischemia-reperfusion group. In vitro, somatostatin significantly inhibited IL-6 and promoted IgM by increasing the expression of both PAX-5 and BLIMP-1 in the proinflammatory condition. Conclusion Intestinal ischemia-reperfusion resulted in the proliferation of unmatured B cells which were involved in the augmentation of innate immunity. Somatostatin, with a bi-directional regulation function on innate as well as adaptive immunity of B cells, greatly improved B cells mature in macaques during ischemia-reperfusion. Preventive supplements of somatostatin may greatly limit intestinal injury and bacterial translocation during ischemia-reperfusion. PMID:26222793

  3. Genetic heterogeneity of diffuse large B-cell lymphoma

    PubMed Central

    Zhang, Jenny; Grubor, Vladimir; Love, Cassandra L.; Banerjee, Anjishnu; Richards, Kristy L.; Mieczkowski, Piotr A.; Dunphy, Cherie; Choi, William; Au, Wing Yan; Srivastava, Gopesh; Lugar, Patricia L.; Rizzieri, David A.; Lagoo, Anand S.; Bernal-Mizrachi, Leon; Mann, Karen P.; Flowers, Christopher; Naresh, Kikkeri; Evens, Andrew; Gordon, Leo I.; Czader, Magdalena; Gill, Javed I.; Hsi, Eric D.; Liu, Qingquan; Fan, Alice; Walsh, Katherine; Jima, Dereje; Smith, Lisa L.; Johnson, Amy J.; Byrd, John C.; Luftig, Micah A.; Ni, Ting; Zhu, Jun; Chadburn, Amy; Levy, Shawn; Dunson, David; Dave, Sandeep S.

    2013-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma in adults. The disease exhibits a striking heterogeneity in gene expression profiles and clinical outcomes, but its genetic causes remain to be fully defined. Through whole genome and exome sequencing, we characterized the genetic diversity of DLBCL. In all, we sequenced 73 DLBCL primary tumors (34 with matched normal DNA). Separately, we sequenced the exomes of 21 DLBCL cell lines. We identified 322 DLBCL cancer genes that were recurrently mutated in primary DLBCLs. We identified recurrent mutations implicating a number of known and not previously identified genes and pathways in DLBCL including those related to chromatin modification (ARID1A and MEF2B), NF-?B (CARD11 and TNFAIP3), PI3 kinase (PIK3CD, PIK3R1, and MTOR), B-cell lineage (IRF8, POU2F2, and GNA13), and WNT signaling (WIF1). We also experimentally validated a mutation in PIK3CD, a gene not previously implicated in lymphomas. The patterns of mutation demonstrated a classic long tail distribution with substantial variation of mutated genes from patient to patient and also between published studies. Thus, our study reveals the tremendous genetic heterogeneity that underlies lymphomas and highlights the need for personalized medicine approaches to treating these patients. PMID:23292937

  4. B Cells and Autoantibodies in Multiple Sclerosis

    PubMed Central

    Pröbstel, Anne-Katrin; Sanderson, Nicholas S. R.; Derfuss, Tobias

    2015-01-01

    While over the past decades T cells have been considered key players in the pathogenesis of multiple sclerosis (MS), it has only recently become evident that B cells have a major contributing role. Our understanding of the role of B cells has evolved substantially following the clinical success of B cell-targeting therapies and increasing experimental evidence for significant B cell involvement. Rather than mere antibody-producing cells, it is becoming clear that they are team players with the capacity to prime and regulate T cells, and function both as pro- and anti-inflammatory mediators. However, despite tremendous efforts, the target antigen(s) of B cells in MS have yet to be identified. The first part of this review summarizes the clinical evidence and results from animal studies pointing to the relevance of B cells in the pathogenesis of MS. The second part gives an overview of the currently known potential autoantigen targets. The third part recapitulates and critically appraises the currently available B cell-directed therapies. PMID:26197319

  5. Consistent intergenic splicing and production of multiple transcripts between AML1 at 21q22 and unrelated genes at 3q26 in (3;21)(q26;q22) translocations

    SciTech Connect

    Nucifora, G.; Begy, C.R.; Kobayashi, H.; Roulston, D.; Rowley, J.D.; Claxton, D.; Pedersen-Bjergaard, J.; Parganas, E.; Ihle, J.N.

    1994-04-26

    Two genes have been implicated in leukemias of patients with abnormalities of chromosome 3, band q26: EVI1, which can be activated over long distances by chromosomal rearrangements involving 3q26, and EAP, a ribosomal gene that fuses with AML1 in a therapy-related myelodysplasia patient with a t(3;21)(q26.2;q22). AML1 was identified by its involvement in the t(8;21)(q22;q22) of acute myeloid leukemia. Here the authors report the consistent identification of fusion transcripts between AML1 and EAP or between AML1 and previously unidentified sequences that was named MDS1 (MDS)-associated sequences in the leukemic cells of four patients with therapy-related myelodysplasia/acute myeloid leukemia and in one patient with chronic myelogenous leukemia in blast crisis, all of whom had a t(3;21). In addition, they have identified a third chimeric transcript, AML1/EVI1, in one of the therapy-related acute myeloid leukemia patients. Pulsed-field gel electrophoresis established the order of the genes as EAP, the most telomeric, and EVI1, the most centromeric, gene. The results indicate that translocations could involve multiple genes and affect gene expression over long distances.

  6. Ulnar ray defect in an infant with a 6q21;7q31.2 translocation: Further evidence of the existence of a limb defect gene in 6q21

    SciTech Connect

    Gurrieri, F.; Genuardi, M.; Pomponi, M.G.

    1995-01-30

    Ectrodactyly is a developmental defect of the distal limbs characterized by marked clinical variability and genetic heterogeneity, also reflected in the observation of different chromosome abnormalities nonrandomly associated with longitudinal postaxial limb deficiencies. The one most frequently found in patients with split hand-split foot (SHSF) involves chromosome band 7q22. Recently, structural anomalies of chromosome 6q21 have been reported in 2 unrelated patients with SHSF, suggesting that this region may also contain genes responsible for limb development. We report on a third patient who had a de novo, apparently balanced t(6;7)(q21;q31.2) translocation and bilateral ulnar aplasia with postaxial oligodactyly. In spite of the different phenotypic effects observed in these 3 patients, we consider our case as further evidence that genes in 6q21 may play a role in distal limb development. 8 refs., 3 figs.

  7. Genomic Landscape of Primary Mediastinal B-Cell Lymphoma Cell Lines

    PubMed Central

    Nagel, Stefan; Eberth, Sonja; Pommerenke, Claudia; Dirks, Wilhelm G.; Geffers, Robert; Kalavalapalli, Srilaxmi; Kaufmann, Maren; Meyer, Corrina; Faehnrich, Silke; Chen, Suning; Drexler, Hans G.; MacLeod, Roderick A. F.

    2015-01-01

    Primary mediastinal B-Cell lymphoma (PMBL) is a recently defined entity comprising ~2–10% non-Hodgkin lymphomas (NHL). Unlike most NHL subtypes, PMBL lacks recurrent gene rearrangements to serve as biomarkers or betray target genes. While druggable, late chemotherapeutic complications warrant the search for new targets and models. Well characterized tumor cell lines provide unlimited material to serve as preclinical resources for verifiable analyses directed at the discovery of new biomarkers and pathological targets using high throughput microarray technologies. The same cells may then be used to seek intelligent therapies directed at clinically validated targets. Four cell lines have emerged as potential PMBL models: FARAGE, KARPAS-1106P, MEDB-1 and U-2940. Transcriptionally, PMBL cell lines cluster near c(lassical)-HL and B-NHL examples showing they are related but separate entities. Here we document genomic alterations therein, by cytogenetics and high density oligonucleotide/SNP microarrays and parse their impact by integrated global expression profiling. PMBL cell lines were distinguished by moderate chromosome rearrangement levels undercutting cHL, while lacking oncogene translocations seen in B-NHL. In total 61 deletions were shared by two or more cell lines, together with 12 amplifications (?4x) and 72 homozygous regions. Integrated genomic and transcriptional profiling showed deletions to be the most important class of chromosome rearrangement. Lesions were mapped to several loci associated with PMBL, e.g. 2p15 (REL/COMMD1), 9p24 (JAK2, CD274), 16p13 (SOCS1, LITAF, CIITA); plus new or tenuously associated loci: 2p16 (MSH6), 6q23 (TNFAIP3), 9p22 (CDKN2A/B), 20p12 (PTPN1). Discrete homozygous regions sometimes substituted focal deletions accompanied by gene silencing implying a role for epigenetic or mutational inactivation. Genomic amplifications increasing gene expression or gene-activating rearrangements were respectively rare or absent. Our findings highlight biallelic deletions as a major class of chromosomal lesion in PMBL cell lines, while endorsing the latter as preclinical models for hunting and testing new biomarkers and actionable targets. PMID:26599546

  8. The t(14;21)(q11.2;q22) chromosomal translocation associated with T-cell acute lymphoblastic leukemia activates the BHLHB1 gene

    PubMed Central

    Wang, Junjie; Jani-Sait, Sheila N.; Escalon, Enrique A.; Carroll, Andrew J.; de Jong, Pieter J.; Kirsch, Ilan R.; Aplan, Peter D.

    2000-01-01

    We have cloned the genomic breakpoints for a balanced t(14;21)(q11.2;q22) chromosomal translocation associated with T-cell acute lymphoblastic leukemia. Sequence analysis of the genomic breakpoints indicated that the translocation had been mediated by an illegitimate V(D)J recombination event that disrupted the T-cell receptor (TCR) ? locus and placed the TCR ? locus enhancer on the derivative 21 chromosome. We identified a previously unreported transcript, designated BHLHB1 (for basic domain, helix–loop–helix protein, class B, 1) that had been activated by the translocation. BHLHB1 mapped to the region of chromosome 21 that has been proposed to be responsible, at least in part, for the learning deficits seen in children with Down's syndrome. Although BHLHB1 expression normally is restricted to neural tissues, T-cell lymphoblasts with the t(14;21)(q11.2;q22) also expressed high levels of BHLHB1 mRNA. Expression of BHLHB1 dramatically inhibited E2A-mediated transcription activation in NIH 3T3 fibroblasts and Jurkat T cells. This observation suggests that BHLHB1, similar to SCL/TAL1, may exert a leukemogenic effect through a functional inactivation of E2A or related proteins. PMID:10737801

  9. [Chromosome translocations and Epstein-Barr virus in Burkitt's lymphoma].

    PubMed

    Bornkamm, G W; Polack, A; Eick, D; Berger, R; Lenoir, G M

    1987-08-01

    Burkitt's lymphoma is characterized by particular epidemiological features. It is a frequent childhood tumor in children in tropical Africa and occurs at a much lesser frequency all over the world. Chromosomal translocation affecting the long arm of chromosome 8 (band 8q24) and one of the chromosomes carrying the immunoglobulin loci (chromosomes 2, 14 or 22) are regularly observed in Burkitt's lymphoma, regardless of whether the tumor occurred in high or low incidence areas. The prevalence of Burkitt's lymphoma in Africa appears to be related to two factors: holo- or hyperendemic malaria and presence of Epstein-Barr virus genomes in the tumor cells. We present a model of pathogenesis, in which stimulation of B cells by malaria is the primary event in the development of the disease. The risk of the chromosomal translocation should be increased by increasing the number of new B cells generated per time. According to our model, the translocation leads to constitutive c-myc activation and makes the cells responsive to growth factors without inducing proliferation on its own. Infection of a translocation-carrying cell with EBV may provide an additional growth advantage and drive the cell further towards a fully malignant state. PMID:2823199

  10. Translocating Laysan Teal

    USGS Multimedia Gallery

    John Klavitter of the US Fish and Wildlife Service, left, and USGS biologist Michelle Reynolds attach transmitters to critically endangered Laysan teal that were translocated from Laysan to Midway Island to expand the species' population and range. ...

  11. Ageing of the B-cell repertoire.

    PubMed

    Martin, Victoria; Bryan Wu, Yu-Chang; Kipling, David; Dunn-Walters, Deborah

    2015-09-01

    Older people are more susceptible to infection, less responsive to vaccination and have a more inflammatory immune environment. Using spectratype analysis, we have previously shown that the B-cell repertoire of older people shows evidence of inappropriate clonal expansions in the absence of challenge, and that this loss of B-cell diversity correlates with poor health. Studies on response to vaccination, using both spectratyping and high-throughput sequencing of the repertoire, indicate that older responses to challenge are lacking in magnitude and/or delayed significantly. Also that some of the biologically significant differences may be in different classes of antibody. We have also previously shown that normal young B-cell repertoires can vary between different phenotypic subsets of B cells. In this paper, we present an analysis of immunoglobulin repertoire in different subclasses of antibody in five different populations of B cell, and show how the repertoire in these different groups changes with age. Although some age-related repertoire differences occur in naive cells, before exogenous antigen exposure, we see indications that there is a general dysregulation of the selective forces that shape memory B-cell populations in older people. PMID:26194751

  12. Overexpression of Fkbp11, a feature of lupus B cells, leads to B cell tolerance breakdown and initiates plasma cell differentiation.

    PubMed

    Ruer-Laventie, Julie; Simoni, Léa; Schickel, Jean-Nicolas; Soley, Anne; Duval, Monique; Knapp, Anne-Marie; Marcellin, Luc; Lamon, Delphine; Korganow, Anne-Sophie; Martin, Thierry; Pasquali, Jean-Louis; Soulas-Sprauel, Pauline

    2015-09-01

    Systemic Lupus Erythematosus (SLE) is a severe systemic autoimmune disease, characterized by multi-organ damages, triggered by an autoantibody-mediated inflammation, and with a complex genetic influence. It is today accepted that adult SLE arises from the building up of many subtle gene variations, each one adding a new brick on the SLE susceptibility and contributing to a phenotypic trait to the disease. One of the ways to find these gene variations consists in comprehensive analysis of gene expression variation in a precise cell type, which can constitute a good complementary strategy to genome wide association studies. Using this strategy, and considering the central role of B cells in SLE, we analyzed the B cell transcriptome of quiescent SLE patients, and identified an overexpression of FKBP11, coding for a cytoplasmic putative peptidyl-prolyl cis/trans isomerase and chaperone enzyme. To understand the consequences of FKBP11 overexpression on B cell function and on autoimmunity's development, we created lentiviral transgenic mice reproducing this gene expression variation. We showed that high expression of Fkbp11 reproduces by itself two phenotypic traits of SLE in mice: breakdown of B cell tolerance against DNA and initiation of plasma cell differentiation by acting upstream of Pax5 master regulator gene. PMID:26417441

  13. Overexpression of Fkbp11, a feature of lupus B cells, leads to B cell tolerance breakdown and initiates plasma cell differentiation

    PubMed Central

    Ruer-Laventie, Julie; Simoni, Léa; Schickel, Jean-Nicolas; Soley, Anne; Duval, Monique; Knapp, Anne-Marie; Marcellin, Luc; Lamon, Delphine; Korganow, Anne-Sophie; Martin, Thierry; Pasquali, Jean-Louis; Soulas-Sprauel, Pauline

    2015-01-01

    Systemic Lupus Erythematosus (SLE) is a severe systemic autoimmune disease, characterized by multi-organ damages, triggered by an autoantibody-mediated inflammation, and with a complex genetic influence. It is today accepted that adult SLE arises from the building up of many subtle gene variations, each one adding a new brick on the SLE susceptibility and contributing to a phenotypic trait to the disease. One of the ways to find these gene variations consists in comprehensive analysis of gene expression variation in a precise cell type, which can constitute a good complementary strategy to genome wide association studies. Using this strategy, and considering the central role of B cells in SLE, we analyzed the B cell transcriptome of quiescent SLE patients, and identified an overexpression of FKBP11, coding for a cytoplasmic putative peptidyl-prolyl cis/trans isomerase and chaperone enzyme. To understand the consequences of FKBP11 overexpression on B cell function and on autoimmunity's development, we created lentiviral transgenic mice reproducing this gene expression variation. We showed that high expression of Fkbp11 reproduces by itself two phenotypic traits of SLE in mice: breakdown of B cell tolerance against DNA and initiation of plasma cell differentiation by acting upstream of Pax5 master regulator gene. PMID:26417441

  14. Functional Characterization of the Plastidic Phosphate Translocator Gene Family from the Thermo-Acidophilic Red Alga Galdieria sulphuraria Reveals Specific Adaptations of Primary Carbon Partitioning in Green Plants and Red Algae1[W][OA

    PubMed Central

    Linka, Marc; Jamai, Aziz; Weber, Andreas P.M.

    2008-01-01

    In chloroplasts of green plants and algae, CO2 is assimilated into triose-phosphates (TPs); a large part of these TPs is exported to the cytosol by a TP/phosphate translocator (TPT), whereas some is stored in the plastid as starch. Plastidial phosphate translocators have evolved from transport proteins of the host endomembrane system shortly after the origin of chloroplasts by endosymbiosis. The red microalga Galdieria sulphuraria shares three conserved putative orthologous transport proteins with the distantly related seed plants and green algae. However, red algae, in contrast to green plants, store starch in their cytosol, not inside plastids. Hence, due to the lack of a plastidic starch pool, a larger share of recently assimilated CO2 needs to be exported to the cytosol. We thus hypothesized that red algal transporters have distinct substrate specificity in comparison to their green orthologs. This hypothesis was tested by expression of the red algal genes in yeast (Saccharomyces cerevisiae) and assessment of their substrate specificities and kinetic constants. Indeed, two of the three red algal phosphate translocator candidate orthologs have clearly distinct substrate specificities when compared to their green homologs. GsTPT (for G. sulphuraria TPT) displays very narrow substrate specificity and high affinity; in contrast to green plant TPTs, 3-phosphoglyceric acid is poorly transported and thus not able to serve as a TP/3-phosphoglyceric acid redox shuttle in vivo. Apparently, the specific features of red algal primary carbon metabolism promoted the evolution of a highly efficient export system with high affinities for its substrates. The low-affinity TPT of plants maintains TP levels sufficient for starch biosynthesis inside of chloroplasts, whereas the red algal TPT is optimized for efficient export of TP from the chloroplast. PMID:18799657

  15. An incoherent regulatory network architecture that orchestrates B cell diversification in response to

    E-print Network

    Dinner, Aaron

    An incoherent regulatory network architecture that orchestrates B cell diversification in response-lymphocyte lineage is a leading system for analyzing gene regulatory networks (GRNs) that orchestrate distinct cell; bistability; gene regulatory network; ghost of a fixed point; Irf4 This is an open-access article distributed

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

    PubMed

    Badial, Peres R; Tallmadge, Rebecca L; Miller, Steven; Stokol, Tracy; Richards, Kristy; Borges, Alexandre S; Felippe, M Julia B

    2015-11-01

    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

  17. Syk Tyrosine Kinase Is Critical for B Cell Antibody Responses and Memory B Cell Survival

    PubMed Central

    Ackermann, Jochen A.; Nys, Josquin; Schweighoffer, Edina; McCleary, Scott; Smithers, Nicholas

    2015-01-01

    Signals from the BCR are required for Ag-specific B cell recruitment into the immune response. Binding of Ag to the BCR induces phosphorylation of immune receptor tyrosine-based activation motifs in the cytoplasmic domains of the CD79a and CD79b signaling subunits, which subsequently bind and activate the Syk protein tyrosine kinase. Earlier work with the DT40 chicken B cell leukemia cell line showed that Syk was required to transduce BCR signals to proximal activation events, suggesting that Syk also plays an important role in the activation and differentiation of primary B cells during an immune response. In this study, we show that Syk-deficient primary mouse B cells have a severe defect in BCR-induced activation, proliferation, and survival. Furthermore, we demonstrate that Syk is required for both T-dependent and T-independent Ab responses, and that this requirement is B cell intrinsic. In the absence of Syk, Ag fails to induce differentiation of naive B cells into germinal center B cells and plasma cells. Finally, we show that the survival of existing memory B cells is dependent on Syk. These experiments demonstrate that Syk plays a critical role in multiple aspects of B cell Ab responses. PMID:25862820

  18. Processing of CD74 by the Intramembrane Protease SPPL2a Is Critical for B Cell Receptor Signaling in Transitional B Cells.

    PubMed

    Hüttl, Susann; Kläsener, Kathrin; Schweizer, Michaela; Schneppenheim, Janna; Oberg, Hans-Heinrich; Kabelitz, Dieter; Reth, Michael; Saftig, Paul; Schröder, Bernd

    2015-08-15

    The invariant chain (CD74), a chaperone in MHC class II-mediated Ag presentation, is sequentially processed by different endosomal proteases. We reported recently that clearance of the final membrane-bound N-terminal fragment (NTF) of CD74 is mediated by the intramembrane protease signal peptide peptidase-like (SPPL)2a, a process critical for B cell development. In mice, SPPL2a deficiency provokes the accumulation of this NTF in endocytic vesicles, which leads to a B cell maturation arrest at the transitional 1 stage. To define the underlying mechanism, we analyzed the impact of SPPL2a deficiency on signaling pathways involved in B cell homeostasis. We demonstrate that tonic as well as BCR-induced activation of the PI3K/Akt pathway is massively compromised in SPPL2a(-/-) B cells and identify this as major cause of the B cell maturation defect in these mice. Altered BCR trafficking induces a reduction of surface IgM in SPPL2a-deficient B cells, leading to a diminished signal transmission via the BCR and the tyrosine kinase Syk. We provide evidence that in SPPL2a(-/-) mice impaired BCR signaling is to a great extent provoked by the accumulating CD74 NTF, which can interact with the BCR and Syk, and that impaired PI3K/Akt signaling and reduced surface IgM are not directly linked processes. In line with disturbances in PI3K/Akt signaling, SPPL2a(-/-) B cells show a dysregulation of the transcription factor FOXO1, causing elevated transcription of proapoptotic genes. We conclude that SPPL2a-mediated processing of CD74 NTF is indispensable to maintain appropriate levels of tonic BCR signaling to promote B cell maturation. PMID:26157172

  19. Genetics and diffuse large B-Cell lymphoma.

    PubMed

    Niroula, Rabin; Butera, James

    2015-01-01

    Diffuse large B-Cell lymphoma (DLBCL) is one of the most common and aggressive subtypes of non-Hodgkin's lymphoma (NHL). Gene expression profiling (GEP) studies have identified at least two distinct molecular subtypes of DLBCL termed as germinal center B-cell (GCB) and activated B-cell (ABC). These molecular subtypes represent lymphomas that are driven by very different intracellular oncogenic signaling pathways which have prognostic value and could potentially be exploited for therapeutic benefit in future. There are other oncogenes, namely BCL-2, BCL-6 and MYC, which have been associated with the pathogenesis of DLBCL. Concurrent presence of two oncogenes is present in about 5% of DLBCL and it is termed "double hit lymphoma" (DHL). DHL are associated with an aggressive clinical course and do not respond well to the standard DLBCL immune-chemotherapy regimen, RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). Other aggressive therapeutic approaches including autologous bone marrow transplant have not shown any survival benefit in this subgroup of DLBCL patients. New strategies in development to address this resistance in DHL include the regimen DA-EPOCH-R (dose adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab). Recent studies have shown increased sensitivity of DHL to DA-EPOCH-R chemotherapy and will likely be the new standard of care in this subset of DLBCL patients in the future. [Full article available at http://rimed.org/rimedicaljournal-2015-11.asp, free with no login]. PMID:26517251

  20. Multiple signaling pathways promote B lymphocyte stimulator–dependent B-cell growth and survival

    PubMed Central

    Fox, Casey J.; Schmidt, Madelyn R.; Hammerman, Peter S.; Opferman, Joseph T.; Korsmeyer, Stanley J.; Hilbert, David M.; Thompson, Craig B.

    2008-01-01

    We investigated the mechanism by which B lymphocyte stimulator (BLyS)/BAFF, a tumor necrosis factor superfamily ligand, promotes B-cell survival and resistance to atrophy. BLyS stimulation activates 2 independent signaling pathways, Akt/mTOR and Pim 2, associated with cell growth and survival. BLyS blocks the cell volume loss (atrophy) that freshly isolated B cells normally undergo when maintained in vitro while concurrently increasing glycolytic activity and overall metabolism. This atrophy resistance requires Akt/mTOR. We used a genetic approach to resolve the contributions of Akt/mTOR and Pim kinase pathways to BLyS-mediated survival. Pim 2–deficient B cells are readily protected from death by BLyS stimulation, but this protection is completely abrogated by treatment with the mTOR inhibitor rapamycin. Furthermore, rapamycin treatment in vivo significantly reduces both follicular and marginal zone B cells in Pim-deficient but not healthy hosts. BLyS-dependent survival requires the antiapoptotic protein Mcl-1. Mcl-1 protein levels rise and fall in response to BLyS addition and withdrawal, respectively, and conditional deletion of the Mcl-1 gene renders B cells refractory to BLyS-mediated protection. Because BlyS is required for the normal homeostasis of all B cells, these data suggest a therapeutic strategy simultaneously inhibiting mTOR and Pim 2 could target pathogenic B cells. PMID:17942753

  1. The contribution of HGAL/GCET2 in immunohistological algorithms: a comparative study in 424 cases of nodal diffuse large B-cell lymphoma.

    PubMed

    Gualco, Gabriela; Bacchi, Lívia M; Domeny-Duarte, Pollyanna; Natkunam, Yasodha; Bacchi, Carlos E

    2012-11-01

    Diffuse large B-cell lymphoma can be subclassified into at least two molecular subgroups by gene expression profiling: germinal center B-cell like and activated B-cell like diffuse large B-cell lymphoma. Several immunohistological algorithms have been proposed as surrogates to gene expression profiling at the level of protein expression, but their reliability has been an issue of controversy. Furthermore, the proportion of misclassified cases of germinal center B-cell subgroup by immunohistochemistry, in all reported algorithms, is higher compared with germinal center B-cell cases defined by gene expression profiling. We analyzed 424 cases of nodal diffuse large B-cell lymphoma with the panel of markers included in the three previously described algorithms: Hans, Choi, and Tally. To test whether the sensitivity of detecting germinal center B-cell cases could be improved, the germinal center B-cell marker HGAL/GCET2 was also added to all three algorithms. Our results show that the inclusion of HGAL/GCET2 significantly increased the detection of germinal center B-cell cases in all three algorithms (P<0.001). The proportions of germinal center B-cell cases in the original algorithms were 27%, 34%, and 19% for Hans, Choi, and Tally, respectively. In the modified algorithms, with the inclusion of HGAL/GCET2, the frequencies of germinal center B-cell cases were increased to 38%, 48%, and 35%, respectively. Therefore, HGAL/GCET2 protein expression may function as a marker for germinal center B-cell type diffuse large B-cell lymphoma. Consideration should be given to the inclusion of HGAL/GCET2 analysis in algorithms to better predict the cell of origin. These findings bear further validation, from comparison to gene expression profiles and from clinical/therapeutic data. PMID:22743653

  2. Longitudinal Studies of a B Cell-Derived Signature of Tolerance in Renal Transplant Recipients.

    PubMed

    Newell, K A; Asare, A; Sanz, I; Wei, C; Rosenberg, A; Gao, Z; Kanaparthi, S; Asare, S; Lim, N; Stahly, M; Howell, M; Knechtle, S; Kirk, A; Marks, W H; Kawai, T; Spitzer, T; Tolkoff-Rubin, N; Sykes, M; Sachs, D H; Cosimi, A B; Burlingham, W J; Phippard, D; Turka, L A

    2015-11-01

    Biomarkers of transplant tolerance would enhance the safety and feasibility of clinical tolerance trials and potentially facilitate management of patients receiving immunosuppression. To this end, we examined blood from spontaneously tolerant renal transplant recipients and patients enrolled in two interventional tolerance trials using flow cytometry and gene expression profiling. Using a previously reported tolerant cohort as well as newly identified tolerant patients, we confirmed our previous finding that tolerance was associated with increased expression of B cell-associated genes relative to immunosuppressed patients. This was not accounted for merely by an increase in total B cell numbers, but was associated with the increased frequencies of transitional and naïve B cells. Moreover, serial measurements of gene expression demonstrated that this pattern persisted over several years, although patients receiving immunosuppression also displayed an increase in the two most dominant tolerance-related B cell genes, IGKV1D-13 and IGLL-1, over time. Importantly, patients rendered tolerant via induction of transient mixed chimerism, and those weaned to minimal immunosuppression, showed similar increases in IGKV1D-13 as did spontaneously tolerant individuals. Collectively, these findings support the notion that alterations in B cells may be a common theme for tolerant kidney transplant recipients, and that it is a useful monitoring tool in prospective trials. PMID:26461968

  3. [Chronic B-cell lymphoproliferative disorders with hairy cells].

    PubMed

    Troussard, Xavier; Cornet, Édouard

    2015-01-01

    The standardized blood smear examination is the first step in the diagnosis of a B-cell chronic lymphoproliferative disorder and can guide further investigations. In the laboratory, the identification of hairy cells on blood smear is a matter of daily practice. Hairy cell proliferations represent heterogeneous entities and their respective diagnoses can be difficult. If hairy cell leukemia (HCL) and splenic marginal zone lymphoma (SMZL) represent separate entities, the variant form of HCL (HCLv) and splenic diffuse red pulp small B-cell lymphoma (SDRPL) remain provisional entities in the 2008 WHO classification. We discuss the main clinical and biological characteristics of these four entities and appropriate means to characterize, identify and distinguish from each other; standardized blood smear examination, multiparameter flow cytometry analysis, analysis of the repertoire of immunoglobulins heavy chains genes and their mutational status (mutated or unmutated profile), molecular analyses: BRAF gene V600E mutation in HCL and MAP2K1 gene mutations in HCLv. We also discuss the main therapeutic aspects with emphasis on the new targeted drugs that enter into force in the therapeutic arsenal. PMID:25858127

  4. Receptor Dissociation and B-Cell Activation.

    PubMed

    Yang, Jianying; Reth, Michael

    2016-01-01

    The B-cell antigen receptor (BCR) is one of the most abundant receptors on the surface of B cells with roughly 100,000-200,000 copies per cell. Signaling through the BCR is crucial for the activation and differentiation of B cells. Unlike other receptors, the BCR can be activated by a large set of structurally different ligands, but the molecular mechanism of BCR activation is still a matter of controversy. Although dominant for a long time, the cross-link model (CLM) of BCR activation is not supported by recent studies of the nanoscale organization of the BCR on the surface of resting B cells. In contrast to the prediction of CLM, the numerous BCR complexes on these cells are not randomly distributed monomers but rather form oligomers which reside within membrane confinements. This finding is more in line with the dissociation activation model (DAM) , wherein B-cell activation is accompanied by an opening of the auto-inhibited BCR oligomers instead of a cross-linking of the BCR monomers . In this review, we discuss in detail the new findings and their implications for BCR signaling. PMID:26428245

  5. Human norovirus culture in B cells

    PubMed Central

    Jones, Melissa K; Grau, Katrina R; Costantini, Veronica; Kolawole, Abimbola O; de Graaf, Miranda; Freiden, Pamela; Graves, Christina L; Koopmans, Marion; Wallet, Shannon M; Tibbetts, Scott A; Schultz-Cherry, Stacey; Wobus, Christiane E; Vinjé, Jan; Karst, Stephanie M

    2015-01-01

    Human noroviruses (HunoVs) are a leading cause of foodborne disease and severe childhood diarrhea, and they cause a majority of the gastroenteritis outbreaks worldwide. However, the development of effective and long-lasting HunoV vaccines and therapeutics has been greatly hindered by their uncultivability. We recently demonstrated that a HunoV replicates in human B cells, and that commensal bacteria serve as a cofactor for this infection. In this protocol, we provide detailed methods for culturing the GII.4-sydney HunoV strain directly in human B cells, and in a coculture system in which the virus must cross a confluent epithelial barrier to access underlying B cells. We also describe methods for bacterial stimulation of HunoV B cell infection and for measuring viral attachment to the surface of B cells. Finally, we highlight variables that contribute to the efficiency of viral replication in this system. Infection assays require 3 d and attachment assays require 3 h. analysis of infection or attachment samples, including rna extraction and rt-qpcr, requires ~6 h. PMID:26513671

  6. Human norovirus culture in B cells.

    PubMed

    Jones, Melissa K; Grau, Katrina R; Costantini, Veronica; Kolawole, Abimbola O; de Graaf, Miranda; Freiden, Pamela; Graves, Christina L; Koopmans, Marion; Wallet, Shannon M; Tibbetts, Scott A; Schultz-Cherry, Stacey; Wobus, Christiane E; Vinjé, Jan; Karst, Stephanie M

    2015-12-01

    Human noroviruses (HuNoVs) are a leading cause of foodborne disease and severe childhood diarrhea, and they cause a majority of the gastroenteritis outbreaks worldwide. However, the development of effective and long-lasting HuNoV vaccines and therapeutics has been greatly hindered by their uncultivability. We recently demonstrated that a HuNoV replicates in human B cells, and that commensal bacteria serve as a cofactor for this infection. In this protocol, we provide detailed methods for culturing the GII.4-Sydney HuNoV strain directly in human B cells, and in a coculture system in which the virus must cross a confluent epithelial barrier to access underlying B cells. We also describe methods for bacterial stimulation of HuNoV B cell infection and for measuring viral attachment to the surface of B cells. Finally, we highlight variables that contribute to the efficiency of viral replication in this system. Infection assays require 3 d and attachment assays require 3 h. Analysis of infection or attachment samples, including RNA extraction and RT-qPCR, requires ?6 h. PMID:26513671

  7. Production of autoantibodies against citrullinated antigens/peptides by human B cells.

    PubMed

    Bellatin, Maria F; Han, Mei; Fallena, Margarita; Fan, Lin; Xia, Donglan; Olsen, Nancy; Branch, Valerie; Karp, David; Stastny, Peter

    2012-04-01

    Autoantibodies against citrullinated protein Ags (ACPA) are associated with the development of rheumatoid arthritis (RA). This immune response against citrullinated protein Ags, which is thought to be facilitated by certain MHC HLA-DR alleles, is highly specific for this disease and has been speculated to be involved in the pathogenesis. We have previously studied cultures of B cells for the production of Abs against HLA Ags. The aim of the current study was to examine the role of B cells in the production of ACPA in patients with RA. Peripheral blood B cells from RA patients and healthy people were cultured with EL4-B5, a murine cell line expressing human CD40L, and with T cell factors to stimulate the in vitro production of Abs by B cells isolated from peripheral blood. ACPA were produced by cultured B cells from RA patients, as determined by reactivity to cyclic citrullinated peptide (CCP). The results showed that 22% of the healthy persons tested also had B cells that could produce ACPA. Patients with HLA-DR alleles carrying the RA-associated shared epitope appeared to have more B cells with autoimmune potential for CCP than those without such HLA alleles (odds ratio 8.1, p = 0.001). In healthy individuals, anti-CCP-producing B cells were also observed more frequently if the RA-associated MHC genes were present (odds ratio 8.0, p = 0.01). Analysis of B cells in cultures may shed light on the interaction of genetic and environmental factors in the development of RA. PMID:22345652

  8. Expression of fibroblast growth factor and FGF-receptor family genes in human myeloma cells, including lines possessing t(4;14)(q16.3;q32. 3) and FGFR3 translocation.

    PubMed

    Otsuki, T; Yamada, O; Yata, K; Sakaguchi, H; Kurebayashi, J; Nakazawa, N; Taniwaki, M; Yawata, Y; Ueki, A

    1999-12-01

    Recently several chromosomal translocations involved in myeloma cases and myeloma cell lines; i.e., t(11;14)(q13;q32), t('8;14)(q24;q32), t(4;14)(q16.3;q32.3), t(6;14)(p25;q32), and t(14;16)(q32.3;q23), have been identified. These translocations are considered to dysregulate genes which may be concerned with myelomagenesis; i.e., PRAD1/cyclin D1, the c-myc oncogene, FGFR3 (fibroblast growth factor receptor 3), MMSET (multiple myeloma SET domain), MUM1 (multiple myeloma oncogene 1)/IRF4 (interferon regulatory factor 4), and the c-maf oncogene, respectively. However, the cellular biological roles of these genes have not yet been elucidated in myeloma cells. Because two of the seven human myeloma cell lines which were established at Kawasaki Medical School, Okayama, Japan, KMS-11 and KMS-18, have been proven to possess t(4;14)(q16.3;q32.3), we studied the expression levels of the FGFR3 gene in these seven cell lines and 13 primary myeloma specimens. The expression levels of 12 known FGF family genes (FGF-1 to 12) and 4 FGFR genes (FGFR1 to 4) were also examined in seven cell lines. In addition, the growth status of the KMS-11 and KMS-18 lines with FGF-1 or anti-FGF-4 neutralizing monoclonal antibody (MoAb) supplementation was investigated because FGF-1 and 4 are known as the principal ligands for FGFR3. FGFR3 overexpression was observed in both of the cell lines possessing t(4;14)(q16.3;q32.3) and in 3 of 13 case specimens. Anti-FGF-4 neutralizing MoAb caused significant growth inhibition in these two cell lines possessing t(4;14)(q16.3;q32.3). These findings indicate that t(4;14) (q16. 3;q32.3) may provide myeloma cells with a growth advantage via an autocrine mechanism between FGFR3 and FGF-4. PMID:10568829

  9. Stripe rust resistance and dough quality of new wheat - Dasypyrum villosum translocation lines T1DL•1V#3S and T1DS•1V#3L and the location of HMW-GS genes.

    PubMed

    Zhao, W C; Gao, X; Dong, J; Zhao, Z J; Chen, Q G; Chen, L G; Shi, Y G; Li, X Y

    2015-01-01

    The transfer of agronomically useful genes from wild wheat species into cultivated wheat is one of the most effective approaches to improvement of wheat varieties. To evaluate the transfer of genes from Dasypyrum villosum into Triticum aestivum, wheat quality and disease resistance was evaluated in two new translocation lines, T1DL•1V#3S and T1DS•1V#3L. We examined the levels of stripe rust resistance and dough quality in the two lines, and identified and located the stripe rust resistant genes and high molecular weight glutenin subunit (HMW-GS) genes Glu-V1 of D. villosum. Compared to the Chinese Spring (CS) variety, T1DL•1V#3S plants showed moderate resistance to moderate susceptibility to the stripe rust races CYR33 and Su11-4. However, T1DS•1V#3L plants showed high resistance or immunity to these stripe rusts. The genes for resistance to stripe rust were located on 1VL of D. villosum. In comparison to CS, the dough from T1DS•1V#3L had a significantly shorter developing time (1.45 min) and stable time (1.0 min), a higher weakness in gluten strength (208.5 FU), and a lower farinograph quality index (18). T1DL•1V#3S had a significantly longer developing time (4.2 min) and stable time (5.25 min), a lower weakness in gluten strength (53 FU) and a higher farinograph quality index (78.5). We also found that T1DS•1V#3L had reduced gluten strength and dough quality compared to CS, but T1DL•1V#3S had increased gluten strength and dough quality. The results of SDS-PAGE analysis indicated that Glu-V1 of D. villosum was located on short arm 1VS and long arm 1VL. These results prove that the new translocation lines, T1DS•1V#3L and T1DS•1V#3L, have valuable stripe rust resistance and dough quality traits that will be important for improving wheat quality and resistance in future wheat breeding programs. PMID:26214490

  10. Problem-Elephant Translocation: Translocating the Problem and the Elephant?

    PubMed Central

    Fernando, Prithiviraj; Leimgruber, Peter; Prasad, Tharaka; Pastorini, Jennifer

    2012-01-01

    Human-elephant conflict (HEC) threatens the survival of endangered Asian elephants (Elephas maximus). Translocating “problem-elephants” is an important HEC mitigation and elephant conservation strategy across elephant range, with hundreds translocated annually. In the first comprehensive assessment of elephant translocation, we monitored 16 translocations in Sri Lanka with GPS collars. All translocated elephants were released into national parks. Two were killed within the parks where they were released, while all the others left those parks. Translocated elephants showed variable responses: “homers” returned to the capture site, “wanderers” ranged widely, and “settlers” established home ranges in new areas soon after release. Translocation caused wider propagation and intensification of HEC, and increased elephant mortality. We conclude that translocation defeats both HEC mitigation and elephant conservation goals. PMID:23236404

  11. B cell Mediated Priming Following Pneumococcal Colonization

    PubMed Central

    Rabquer, Bradley; Shriner, Anne K.; Smithson, S. Louise; Julie Westerink, M. A.

    2007-01-01

    The primary reservoir for Streptococcus pneumoniae is the human nasopharynx, and colonization is often the initial step in pathogenesis. Recently we have demonstrated that pneumococcal colonization primes the immune response to subsequent vaccination with the pneumococcal conjugate vaccine (CPV). In this study we wished to determine if colonization stimulates the production of B cell memory that is activated following vaccination with CPV. To test this hypothesis, we colonized mice with S. pneumoniae serotype 14, adoptively transferred their B cells and CD4+ T cells into naïve recipients, and vaccinated the recipients with CPV. Our results indicate that pneumococcal colonization stimulates the production of memory B cells which are responsible for enhancing the immune response to CPV vaccination. PMID:17240006

  12. PSF/SFPQ is a very common gene fusion partner in TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas) and melanotic Xp11 translocation renal cancers: clinicopathologic, immunohistochemical, and molecular characteristics suggesting classification as a distinct entity.

    PubMed

    Rao, Qiu; Shen, Qin; Xia, Qiu-yuan; Wang, Zi-yu; Liu, Biao; Shi, Shan-shan; Shi, Qun-li; Yin, Hong-lin; Wu, Bo; Ye, Sheng-bing; Li, Li; Chen, Jie-Yu; Pan, Min-hong; Li, Qing; Li, Rui; Wang, Xuan; Zhang, Ru-song; Yu, Bo; Ma, Heng-hui; Lu, Zhen-feng; Zhou, Xiao-jun

    2015-09-01

    An increasing number of TFE3 rearrangement-associated tumors, such as TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas), melanotic Xp11 translocation renal cancers, and melanotic Xp11 neoplasms, have recently been reported. We examined 12 such cases, including 5 TFE3 rearrangement-associated PEComas located in the pancreas, cervix, or pelvis and 7 melanotic Xp11 translocation renal cancers, using clinicopathologic, immunohistochemical, and molecular analyses. All the tumors shared a similar morphology, including a purely nested or sheet-like architecture separated by a delicate vascular network, purely epithelioid cells displaying a clear or granular eosinophilic cytoplasm, a lack of papillary structures and spindle cell or fat components, uniform round or oval nuclei containing small visible nucleoli, and, in most cases (11/12), melanin pigmentation. The levels of mitotic activity and necrosis varied. All 12 cases displayed moderately (2+) or strongly (3+) positive immunoreactivity for TFE3 and cathepsin K. One case labeled focally for HMB45 and Melan-A, whereas the others typically labeled moderately (2+) or strongly (3+) for 1 of these markers. None of the cases were immunoreactive for smooth muscle actin, desmin, CKpan, S100, or PAX8. PSF-TFE3 fusion genes were confirmed by reverse transcription polymerase chain reaction in cases (7/7) in which a novel PSF-TFE3 fusion point was identified. All of the cases displayed TFE3 rearrangement associated with Xp11 translocation. Furthermore, we developed a PSF-TFE3 fusion fluorescence in situ hybridization assay for the detection of the PSF-TFE3 fusion gene and detected it in all 12 cases. Clinical follow-up data were available for 7 patients. Three patients died, and 2 patients (cases 1 and 3) remained alive with no evidence of disease after initial resection. Case 2 experienced recurrence and remained alive with disease. Case 5, a recent case, remained alive with extensive abdominal cavity metastases. Our data suggest that these tumors belong to a single clinicopathologic spectrum and expand the known characteristics of TFE3 rearrangement-associated tumors. PMID:26274027

  13. A yeast artificial chromosome contig that spans the RB1-D13S31 interval on human chromosome 13 and encompasses the frequently deleted region in B-cell chronic lymphocytic leukemia

    SciTech Connect

    Hawthorn, L.; Roberts, T.; Cowell, J.K.

    1995-12-10

    Abnormalities involving chromosome 13 have been a reported as the only cytogenetic change in B-cell chronic lymphocytic leukemia (BCLL). Deletions are the most common cytogenetic abnormality and always involve 13q14, but when translocations are seen, the consistent breakpoint is always in 13q14. It is now established that deletions, distal to the RB1 gene in 13q14, are invariably associated with these translocations. We have recently described the smallest such deletion from a series of rearrangements from these tumors isolated in somatic cell hybrids, which spans approximately 1 Mb. In this report, we present the results of a series of a chromosome walking experiments using YACs and have been able to span this small deletion, which must contain the gene that is frequently deleted in BCLL. Four probes from 13q14 (RB1-mgg15-D13S25-D13S31) were used to isolate corresponding YACs for each of the markers. The chromosomal location of these YACs was verified using FISH, which also demonstrated their nonchimeric nature. Vectorette end rescue was then used to demonstrate the overlap of the YACs and to isolate new clones to complete the contig. The extremes of the contig were shown to cross the chromosome 13 translocation breakpoints isolated in somatic cell hybrids that carry the derivatives of chromosome 13 involved in the smallest BCLL deletion. This YAC contig covers the entire deletion and will prove a valuable resource to begin isolating genes from this region. In addition, we have isolated YACs corresponding to the RB1 locus, which extends the contig over a 3.8-cM distance on the chromosome. 25 refs., 1 fig., 1 tab.

  14. High-level DNA amplifications are common genetic aberrations in B-cell neoplasms.

    PubMed Central

    Werner, C. A.; Döhner, H.; Joos, S.; Trümper, L. H.; Baudis, M.; Barth, T. F.; Ott, G.; Möller, P.; Lichter, P.; Bentz, M.

    1997-01-01

    Gene amplification is one of the molecular mechanisms resulting in the up-regulation of gene expression. In non-Hodgkin's lymphomas, such gene amplifications have been identified rarely. Using comparative genomic hybridization, a technique that has proven to be very sensitive for the detection of high-level DNA amplifications, we analyzed 108 cases of B-cell neoplasms (42 chronic B-cell leukemias, 5 mantle cell lymphomas, and 61 aggressive B-cell lymphomas). Twenty-four high-level amplifications were identified in 13% of the patients and mapped to 15 different genomic regions. Regions most frequently amplified were bands Xq26-28, 2p23-24, and 2p14-16 as well as 18q21 (three times each). Amplification of several proto-oncogenes and a cell cycle control gene (N-MYC (two cases), BCL2, CCND2, and GLI) located within the amplified regions was demonstrated by Southern blot analysis or fluorescence in situ hybridization to interphase nuclei of tumor cells. These data demonstrate that gene amplifications in B-cell neoplasms are much more frequent than previously assumed. The identification of highly amplified DNA regions and genes included in the amplicons provides important information for further analyses of genetic events involved in lymphomagenesis. Images Figure 2 Figure 3 PMID:9250147

  15. Translocation-related sarcomas.

    PubMed

    Mertens, Fredrik; Antonescu, Cristina R; Hohenberger, Peter; Ladanyi, Marc; Modena, Piergiorgio; D'Incalci, Maurizio; Casali, Paolo G; Aglietta, Massimo; Alvegård, Thor

    2009-08-01

    Sarcomas with chromosomal translocations represent only about one fourth of sarcoma diagnoses. However, like gastrointestinal stromal tumor (GIST), with its characteristic KIT or PDGFRA mutations, they are particularly interesting since they provide specific biological insights and mechanisms of action that may have an impact upon prognosis or therapy. These are mechanisms we are just beginning to exploit. In this section we will review the biology and clinical impact of translocation-associated sarcomas and review the clinical findings that have made a recent impact upon patients with these diverse diagnoses. PMID:19664492

  16. Biotechnology and the chicken B cell line DT40.

    PubMed

    Bachl, J; Caldwell, R B; Buerstedde, J-M

    2007-01-01

    Protein optimization is a major focus of the biotech and pharmaceutical industry. Various in vitro technologies have been developed to accelerate protein evolution and to achieve protein optimization of functional characteristics such as substrate specificity, enzymatic activity and thermostability. The chicken B cell line DT40 diversifies its immunoglobulin (Ig) gene by gene conversion and somatic hypermutation. This machinery can be directed to almost any gene inserted into the Ig locus. Enormously diverse protein libraries of any gene of interest can be quickly generated in DT40 by utilizing random shuffling of complex genetic domains (gene conversion) and by the introduction of novel non-templated genetic information (random mutagenesis). The unique characteristics of the chicken cell line DT40 make it a powerful in-cell diversification system to improve proteins of interest within living cells. One essential advantage of the DT40 protein optimization approach is the fact that variants are generated within an in-cell system thus allowing the direct screening for desired features in the context of intracellular networks. Utilizing specially designed selection strategies, such as the powerful fluorescent protein technology, enables the reliable identification of protein variants exhibiting the most desirable traits. Thus, DT40 is well positioned as a biotechnological tool to generate optimized proteins by applying a powerful combination of gene specific hypermutation, gene conversion and mutant selection. PMID:17675859

  17. Secondary Rearrangements and Hypermutation Generate Sufficient B Cell Diversity to Mount Protective Antiviral Immunoglobulin Responses

    PubMed Central

    López-Macías, Constantino; Kalinke, Ulrich; Cascalho, Marilia; Wabl, Matthias; Hengartner, Hans; Zinkernagel, Rolf M.; Lamarre, Alain

    1999-01-01

    Variable (V) region gene replacement was recently implicated in B cell repertoire diversification, but the contribution of this mechanism to antibody responses is still unknown. To investigate the role of V gene replacements in the generation of antigen-specific antibodies, we analyzed antiviral immunoglobulin responses of “quasimonoclonal” (QM) mice. The B cells of QM mice are genetically committed to exclusively express the anti-(4-hydroxy-3-nitrophenyl) acetyl specificity. However, ?20% of the peripheral B cells of QM mice undergo secondary rearrangements and thereby potentially acquire new specificities. QM mice infected with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus, or poliovirus mounted virus-specific neutralizing antibody responses. In general, kinetics of the antiviral immunoglobulin responses were delayed in QM mice; however, titers similar to control animals were eventually produced that were sufficient to protect against VSV-induced lethal disease. VSV neutralizing single-chain Fv fragments isolated from phage display libraries constructed from QM mice showed VH gene replacements and extensive hypermutation. Thus, our data demonstrate that secondary rearrangements and hypermutation can generate sufficient B cell diversity in QM mice to mount protective antiviral antibody responses, suggesting that these mechanisms might also contribute to the diversification of the B cell repertoire of normal mice. PMID:10359583

  18. Constitutively activated STAT3 promotes cell proliferation and survival in the activated B-cell subtype of diffuse large B-cell lymphomas

    PubMed Central

    Ding, B. Belinda; Yu, J. Jessica; Yu, Raymond Y.-L.; Mendez, Lourdes M.; Shaknovich, Rita; Zhang, Yonghui; Cattoretti, Giorgio

    2008-01-01

    Diffuse large B-cell lymphoma (DLBCL) consists of at least 2 phenotypic subtypes; that is, the germinal center B-cell–like (GCB-DLBCL) and the activated B-cell–like (ABC-DLBCL) groups. It has been shown that GCB-DLBCL responds favorably to chemotherapy and expresses high levels of BCL6, a transcription repressor known to play a causative role in lymphomagenesis. In comparison, ABC-DLBCL has lower levels of BCL6, constitutively activated nuclear factor-?B, and tends to be refractory to chemotherapy. Here, we report that the STAT3 gene is a transcriptional target of BCL6. As a result, high-level STAT3 expression and activation are preferentially detected in ABC-DLBCL and BCL6-negative normal germinal center B cells. Most importantly, inactivating STAT3 by either AG490 or small interference RNA in ABC-DLBCL cells inhibits cell proliferation and triggers apoptosis. These phenotypes are accompanied by decreased expression of several known STAT3 target genes, including c-Myc, JunB, and Mcl-1, and increased expression of the cell- cycle inhibitor p27. In addition to identifying STAT3 as a novel BCL6 target gene, our results define a second oncogenic pathway, STAT3 activation, which operates in ABC-DLBCL, suggesting that STAT3 may be a new therapeutic target in these aggressive lymphomas. PMID:17951530

  19. Rituximab does not reset defective early B cell tolerance checkpoints.

    PubMed

    Chamberlain, Nicolas; Massad, Christopher; Oe, Tyler; Cantaert, Tineke; Herold, Kevan C; Meffre, Eric

    2016-01-01

    Type 1 diabetes (T1D) patients show abnormalities in early B cell tolerance checkpoints, resulting in the accumulation of large numbers of autoreactive B cells in their blood. Treatment with rituximab, an anti-CD20 mAb that depletes B cells, has been shown to preserve ? cell function in T1D patients and improve other autoimmune diseases, including rheumatoid arthritis and multiple sclerosis. However, it remains largely unknown how anti-B cell therapy thwarts autoimmunity in these pathologies. Here, we analyzed the reactivity of Abs expressed by single, mature naive B cells from 4 patients with T1D before and 52 weeks after treatment to determine whether rituximab resets early B cell tolerance checkpoints. We found that anti-B cell therapy did not alter the frequencies of autoreactive and polyreactive B cells, which remained elevated in the blood of all patients after rituximab treatment. Moreover, the limited proliferative history of autoreactive B cells after treatment revealed that these clones were newly generated B cells and not self-reactive B cells that had escaped depletion and repopulated the periphery through homeostatic expansion. We conclude that anti-B cell therapy may provide a temporary dampening of autoimmune processes through B cell depletion. However, repletion with autoreactive B cells may explain the relapse that occurs in many autoimmune patients after anti-B cell therapy. PMID:26642366

  20. Oncogene Translocations and NHL

    Cancer.gov

    A colloboration with several large population-based cohorts to determine whether the prevalence or level of t14;18 is associated with risk of NHL and to investigate the clonal relationship between translocation-bearing cells and subsequent tumors

  1. Pre-B Cell Receptor Signaling Induces Immunoglobulin ? Locus Accessibility by Functional Redistribution of Enhancer-Mediated Chromatin Interactions

    PubMed Central

    Stadhouders, Ralph; de Bruijn, Marjolein J. W.; Rother, Magdalena B.; Yuvaraj, Saravanan; de Almeida, Claudia Ribeiro; Kolovos, Petros; Van Zelm, Menno C.; van Ijcken, Wilfred; Grosveld, Frank; Soler, Eric; Hendriks, Rudi W.

    2014-01-01

    During B cell development, the precursor B cell receptor (pre-BCR) checkpoint is thought to increase immunoglobulin ? light chain (Ig?) locus accessibility to the V(D)J recombinase. Accordingly, pre-B cells lacking the pre-BCR signaling molecules Btk or Slp65 showed reduced germline V? transcription. To investigate whether pre-BCR signaling modulates V? accessibility through enhancer-mediated Ig? locus topology, we performed chromosome conformation capture and sequencing analyses. These revealed that already in pro-B cells the ? enhancers robustly interact with the ?3.2 Mb V? region and its flanking sequences. Analyses in wild-type, Btk, and Slp65 single- and double-deficient pre-B cells demonstrated that pre-BCR signaling reduces interactions of both enhancers with Ig? locus flanking sequences and increases interactions of the 3?? enhancer with V? genes. Remarkably, pre-BCR signaling does not significantly affect interactions between the intronic enhancer and V? genes, which are already robust in pro-B cells. Both enhancers interact most frequently with highly used V? genes, which are often marked by transcription factor E2a. We conclude that the ? enhancers interact with the V? region already in pro-B cells and that pre-BCR signaling induces accessibility through a functional redistribution of long-range chromatin interactions within the V? region, whereby the two enhancers play distinct roles. PMID:24558349

  2. Primary cutaneous T-cell-rich B-cell lymphoma: clinically distinct from its nodal counterpart?

    PubMed

    Li, S; Griffin, C A; Mann, R B; Borowitz, M J

    2001-01-01

    The cases of two patients with Stage IE primary cutaneous T-cell-rich B-cell lymphoma (TCRBCL) are described. In both, the lesion showed a dense infiltrate by numerous small T lymphocytes with scattered histiocytes and large atypical B-lymphoid cells. Polymerase chain reaction assays demonstrated that the B cells were monoclonal, with immunoglobulin heavy-chain gene rearrangement. No clonal rearrangements of the T-cell receptor gamma gene were observed. Both patients were disease-free at 4 months and at 5 years after therapy, respectively. Although rare, primary cutaneous T-cell-rich B-cell lymphoma appears to have a better prognosis than its nodal counterpart, with or without skin involvement. PMID:11211304

  3. The AP-1 transcription factor Fra1 inhibits follicular B cell differentiation into plasma cells

    PubMed Central

    Grötsch, Bettina; Brachs, Sebastian; Lang, Christiane; Luther, Julia; Derer, Anja; Schlötzer-Schrehardt, Ursula; Bozec, Aline; Fillatreau, Simon; Berberich, Ingolf; Hobeika, Elias; Reth, Michael; Wagner, Erwin F.; Schett, Georg

    2014-01-01

    The cornerstone of humoral immunity is the differentiation of B cells into antibody-secreting plasma cells. This process is tightly controlled by a regulatory gene network centered on the transcriptional repressor B lymphocyte–induced maturation protein 1 (Blimp1). Proliferation of activated B cells is required to foster Blimp1 expression but needs to be terminated to avoid overshooting immune reactions. Activator protein 1 (AP-1) transcription factors become quickly up-regulated upon B cell activation. We demonstrate that Fra1, a Fos member of AP-1, enhances activation-induced cell death upon induction in activated B cells. Moreover, mice with B cell–specific deletion of Fra1 show enhanced plasma cell differentiation and exacerbated antibody responses. In contrast, transgenic overexpression of Fra1 blocks plasma cell differentiation and immunoglobulin production, which cannot be rescued by Bcl2. On the molecular level, Fra1 represses Blimp1 expression and interferes with binding of the activating AP-1 member c-Fos to the Blimp1 promoter. Conversely, overexpression of c-Fos in Fra1 transgenic B cells releases Blimp1 repression. As Fra1 lacks transcriptional transactivation domains, we propose that Fra1 inhibits Blimp1 expression and negatively controls plasma cell differentiation through binding to the Blimp1 promoter. In summary, we demonstrate that Fra1 negatively controls plasma cell differentiation by repressing Blimp1 expression. PMID:25288397

  4. Pre-stimulation of CD81 expression by resting B cells increases proliferation following EBV infection, but the overexpression of CD81 induces the apoptosis of EBV-transformed B cells.

    PubMed

    Park, Ga Bin; Kim, Daejin; Park, Sung Jae; Lee, Hyun-Kyung; Kim, Ji Hyun; Kim, Yeong Seok; Park, Sae-Gwang; Choi, In-Hak; Yoon, Sung Ho; Lee, Youn Jae; Paeng, Sunghwa; Hur, Dae Young

    2015-12-01

    Hepatitis C virus (HCV) E2 protein binds to CD81, which is a component of the B cell co-stimulatory complex. The E2-CD81 interaction leads to B cell proliferation, protein tyrosine phosphorylation and to the hypermutation of immunoglobulin genes. Epidemiological studies have reported a high prevalence of B cell non-Hodgkin lymphoma (NHL) in HCV-positive patients, suggesting a potential association between HCV and Epstein-Barr virus (EBV) in the genesis of B lymphocyte proliferative disorders. In the present study, in order to investigate the association between EBV and HCV in B cells, we created an in vitro EBV-induced B cell transformation model. CD81 was gradually overexpressed during transformation by EBV. B cells isolated from HCV-positive patients grew more rapidly and clumped together earlier than B cells isolated from healthy donors following EBV infection. Pre-stimulation of CD81 expressed by resting B cells with anti-CD81 monoclonal antibody (mAb) or HCV E2 accelerated the generation of lymphoblastoid cell lines (LCLs) by EBV infection. These cells proliferated prominently through the early expression of interleukin-10 and intracellular latent membrane protein (LMP)-l. By contrast, the overexpression of CD81 on EBV-transformed B cells by anti-CD81 mAb or HCV E2 protein induced apoptosis through reactive oxygen species (ROS)-mediated mitochondrial dysfunction. These results suggest that the engagement of CD81 expressed by B cells has differential effects on B cell fate (proliferation or apoptosis) according to EBV infection and the expression level of CD81. PMID:26498453

  5. Pre-stimulation of CD81 expression by resting B cells increases proliferation following EBV infection, but the overexpression of CD81 induces the apoptosis of EBV-transformed B cells

    PubMed Central

    PARK, GA BIN; KIM, DAEJIN; PARK, SUNG JAE; LEE, HYUN-KYUNG; KIM, JI HYUN; KIM, YEONG SEOK; PARK, SAE-GWANG; CHOI, IN-HAK; YOON, SUNG HO; LEE, YOUN JAE; PAENG, SUNGHWA; HUR, DAE YOUNG

    2015-01-01

    Hepatitis C virus (HCV) E2 protein binds to CD81, which is a component of the B cell co-stimulatory complex. The E2-CD81 interaction leads to B cell proliferation, protein tyrosine phosphorylation and to the hypermutation of immunoglobulin genes. Epidemiological studies have reported a high prevalence of B cell non-Hodgkin lymphoma (NHL) in HCV-positive patients, suggesting a potential association between HCV and Epstein-Barr virus (EBV) in the genesis of B lymphocyte proliferative disorders. In the present study, in order to investigate the association between EBV and HCV in B cells, we created an in vitro EBV-induced B cell transformation model. CD81 was gradually overexpressed during transformation by EBV. B cells isolated from HCV-positive patients grew more rapidly and clumped together earlier than B cells isolated from healthy donors following EBV infection. Pre-stimulation of CD81 expressed by resting B cells with anti-CD81 monoclonal antibody (mAb) or HCV E2 accelerated the generation of lymphoblastoid cell lines (LCLs) by EBV infection. These cells proliferated prominently through the early expression of interleukin-10 and intracellular latent membrane protein (LMP)-l. By contrast, the overexpression of CD81 on EBV-transformed B cells by anti-CD81 mAb or HCV E2 protein induced apoptosis through reactive oxygen species (ROS)-mediated mitochondrial dysfunction. These results suggest that the engagement of CD81 expressed by B cells has differential effects on B cell fate (proliferation or apoptosis) according to EBV infection and the expression level of CD81. PMID:26498453

  6. Germinal center B cells and mixed leukocyte reactions

    SciTech Connect

    Monfalcone, A.P.; Kosco, M.H.; Szakal, A.K.; Tew, J.G. )

    1989-09-01

    The present study was undertaken to determine if germinal center (GC) B cells are sufficiently activated to stimulate mixed leukocyte reactions (MLR). Percoll density fractionation and a panning technique with peanut agglutinin (PNA) were used to isolate GC B cells from the lymph nodes of immune mice. The GC B cells were treated with mitomycin C or irradiation and used to stimulate allogeneic or syngeneic splenic T cells in the MLR. Controls included high-density (HD) B cells prepared from spleens of the same mice and HD B cells activated with lipopolysaccharide (LPS) and dextran sulfate. GC B cells bound high amount sof PNA (i.e., PNAhi). Similarly, the LPS-dextran sulfate-activated B cells were PNAhi. Treatment with neuraminidase rendered the PNAlo HD B cells PNAhi. GC B cells and the LPS-dextran sulfate-activated HD B cells stimulated a potent MLR, while the untreated HD B cells did not. However, following neuraminidase treatment, the resulting PNAhi HD B cell population was able to induce an MLR. The PNA marker appeared to be an indicator of stimulatory activity, but incubating the cells with PNA to bind the cell surface ligand did not interfere with the MLR. GC B cells were also capable of stimulating a syngeneic MLR in most experiments although this was not consistently obtained. It appears that germinal centers represent a unique in vivo microenvironment that provides the necessary signals for B cells to become highly effective antigen-presenting cells.

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

    PubMed

    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) ?-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-?B-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. PMID:24962817

  8. Antigen-specific B-cell receptor sensitizes B cells to infection by influenza virus

    E-print Network

    Dougan, Stephanie K.

    Influenza A virus-specific B lymphocytes and the antibodies they produce protect against infection. However, the outcome of interactions between an influenza haemagglutinin-specific B cell via its receptor (BCR) and virus ...

  9. Mitogen-activated protein kinase 6 mediates nuclear translocation of ORE3 to promote ORE9 gene expression in methyl jasmonate-induced leaf senescence.

    PubMed

    Zhang, Yushan; Liu, Jian; Chai, Jinyu; Xing, Da

    2016-01-01

    Methyl jasmonate (MeJA) is a potent promoter of plant senescence. ORESARA3 (ORE3)/ETHYLENE INSENSITIVE2 (EIN2), a protein similar to the members of the disease-related Nramp metal transporter family, is involved in cross-talk among several senescence processes related to abscisic acid, ethylene, MeJA, age and darkness. Nevertheless, the mechanism involved in the regulation of ORE3/EIN2 in exogenous MeJA-induced leaf senescence remains unclear. The C-terminal end of ORE3/EIN2 (CEND) was cleaved from ORE3/EIN2 located in the endoplasmic reticulum and then transferred to the nucleus during MeJA-induced senescence. Further analyses showed that mitogen-activated protein kinase 6 (MPK6) promoted CEND cleavage and nuclear translocation. Nuclear CEND accumulated ETHYLENE INSENSITIVE3 (EIN3), a transcription factor that accelerates MeJA-induced leaf senescence wherein ORESARA9 (ORE9) expression was suppressed in ein3, ore3, and mpk6 mutant plants. ChIP experiments revealed that EIN3 bound directly to the ORE9 promoter and this binding was enhanced in MeJA-induced leaf senescence. This study revealed the effect of the signalling pathway involving MPK6-ORE3-EIN3-ORE9 on regulating leaf senescence and provided insights into the mechanism of MeJA in promoting leaf senescence in Arabidopsis thaliana. PMID:26507893

  10. Retinoic acid and ?-galactosylceramide regulate the expression of costimulatory receptors and transcription factors responsible for B cell activation and differentiation.

    PubMed

    Chen, Qiuyan; Mosovsky, Kara L; Ross, A Catharine

    2013-12-01

    Mature naïve B cells possess a number of BCR coreceptors and other antigen receptors, including the MHC class I-like molecule CD1d, but little is known of the response of B cells to stimulation by the CD1d ligand, ?-galactosylceramide (?GalCer). Previously, we showed that all-trans-retinoic acid (RA) increases the expression of CD1d and the magnitude of CD1d-mediated antibody production in vivo. Potential mechanisms could include changes in the expression of costimulatory molecules and transcription factors that regulate plasma cell formation. In the present study, we have used isolated purified B cells and in vivo studies to demonstrate that ?GalCer and RA initiate a regulated expression of several genes essential for B cell activation and differentiation, such as Pax-5, Blimp-1, IRF-4 and activation-induced cytidine deaminase (Aid). Moreover, whereas ?GalCer mainly increased the expression of Pax-5, CD40 and CD86 that are critical for B cell activation, RA predominantly increased CD138? and Fas?-PNA? B cells, which represent more advanced B cell differentiation. It is also noteworthy that ?GalCer enriched a CD19hi subset of B cells, which represent B cells with more differentiated phenotype and higher potential for antibody production. In vivo, treatment with ?GalCer enriched the CD19hi population, which, after sorting, produced more anti-TT IgG by ELISPOT assay. Together, our data demonstrate that RA and ?GalCer can regulate B cell activation and differentiation at multiple levels in a complementary manner, facilitating the progress of B cells towards antibody secreting cells. PMID:23816303

  11. MicroRNAs in B-cell lymphomas: how a complex biology gets more complex.

    PubMed

    Musilova, K; Mraz, M

    2015-05-01

    MicroRNAs (miRNAs) represent important regulators of gene expression besides transcriptional control. miRNA regulation can be involved in the cell developmental fate decisions, but can also have more subtle roles in buffering stochastic fluctuations in gene expression. They participate in pathways fundamental to B-cell development like B-cell receptor (BCR) signalling, B-cell migration/adhesion, cell-cell interactions in immune niches, and the production and class-switching of immunoglobulins. miRNAs influence B-cell maturation, generation of pre-, marginal zone, follicular, B1, plasma and memory B cells. In this review, we discuss miRNAs with essential functions in malignant B-cell development (such as miR-150, miR-155, miR-21, miR-34a, miR-17-92 and miR-15-16). We also put these miRNAs in the context of normal B-cell differentiation, as this is intimately connected to neoplastic B-cell development. We review miRNAs' role in the most common B-cell malignancies, including chronic lymphocytic leukaemia (CLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and mantle cell lymphoma (MCL). We focus on miR-contribution to the regulation of important signalling pathways (such as NF-?B, PI3K/AKT and TGF-?), BCR signalling and its modulators (such as PTEN, SHIP-1, ZAP-70, GAB1 and BTK), anti- and pro-apoptotic proteins (such as BCL2, MCL1, TCL1, BIM, p53 and SIRT1) and transcription factors (such as MYC, MYB, PU.1, FOXP1 and BCL6). We also discuss the association of miRNAs' expression levels with the patients' survival and response to therapy, summarizing their potential use as predictive and prognostic markers. Importantly, the targeting of miRNAs (like use of anti-miR-155 or miR-34a mimic) could provide a novel therapeutic approach as evidenced by tumour regression in xenograft mouse models and initial promising data from clinical trials. PMID:25541152

  12. Pi, a pre-B-cell-specific enhancer element in the immunoglobulin heavy-chain enhancer.

    PubMed Central

    Libermann, T A; Baltimore, D

    1993-01-01

    We have identified a new immunoglobulin heavy-chain enhancer element, designated pi, between the microE2 and microE3 elements. The pi enhancer element is transcriptionally active primarily during early stages of B-cell development but becomes virtually inactive during B-cell maturation at about the stage of immunoglobulin kappa light-chain gene rearrangement. Mutational analysis suggests that the pi element is crucial for immunoglobulin heavy-chain enhancer activity at the pre-B-cell stage but is almost irrelevant for enhancer activity at the mature B-cell or plasma-cell stage. The activity of the pi enhancer element correlates with the presence of an apparently pre-B-cell-specific protein-DNA complex. The similarity of the pi site to recognition sequences for members of the ets gene family suggests that the protein(s) interacting with the pi site most likely are ets-related transcription factors. Images PMID:8413200

  13. Estrogen receptor signal in regulation of B cell activation during diverse immune responses.

    PubMed

    Asaba, Josaine; Bandyopadhyay, Mausumi; Kindy, Mark; Dasgupta, Subhajit

    2015-11-01

    The role of signalling through oestrogen receptors (ERs) in the regulation of B cell activation is an area of growing importance not only in terms protective immunity but also in the determination of the mechanisms of the onset of autoimmune disorders and cancers. The mode of signalling action of this single chain nuclear receptor protein molecule depends on its ability to bind to the promoters of Pax5, HOXC4 and apolipoprotein B RNA-editing enzyme activation-induced cytidine deaminase (AID) genes. ER-mediated transcriptional regulation induces class switch recombination of the immunoglobulin heavy chain variable (VH) to DH-JH genes and somatic hypermutation in developing B cells. The mode of action of ER is associated with BCR-signal pathways that involve the regulator proteins BAFF and APRIL. Additionally, the plasma membrane-bound G protein-coupled oestrogen receptor-1 (GEPR1) directs diverse cell signalling events in B cells that involve the MAPK pathways. These signals are immensely important during progenitor and precursor B cell activation. We have focused our goals on the medicinal aspects of ER-signalling mechanisms and their effects on polyclonal B cell activation. PMID:26299327

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

    PubMed Central

    Ragheb, Samia; Lisak, Robert P.

    2011-01-01

    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. PMID:22235365

  15. The Ins and Outs of B Cells in Multiple Sclerosis

    PubMed Central

    Blauth, Kevin; Owens, Gregory P.; Bennett, Jeffrey L.

    2015-01-01

    B cells play a central role in multiple sclerosis (MS) pathology. B and plasma cells may contribute to disease activity through multiple mechanisms: antigen presentation, cytokine secretion, or antibody production. Molecular analyses of B cell populations in MS patients have revealed significant overlaps between peripheral lymphoid and clonally expanded central nervous system (CNS) B cell populations, indicating that B cell trafficking may play a critical role in driving MS exacerbations. In this review, we will assess our current knowledge of the mechanisms and pathways governing B cell migration into the CNS and examine evidence for and against a compartmentalized B cell response driving progressive MS pathology. PMID:26594215

  16. Failure of B-cell differentiation in mice lacking the transcription factor EBF.

    PubMed

    Lin, H; Grosschedl, R

    1995-07-20

    Early B-cell factor (EBF) is a cell type-specific transcription factor that is expressed at all antigen-independent stages of B-lymphocyte differentiation and participates in the regulation of the mb-1 gene. Here we show, by targeted gene disruption in mice, that EBF is necessary for the generation of immunoglobulin-expressing B cells. EBF-deficient mice lack B cells that have rearranged their immunoglobulin D and JH gene segments, but contain B220+CD43+ progenitor cells that express germline mu and IL-7 receptor transcripts. Various non-lymphoid tissues that express EBF are apparently normal in homozygous mutant mice, including olfactory neurons in which EBF was identified as Olf-1 (refs 5, 6). Together, these data suggest that EBF plays a specific and important role in the transcriptional control of B-cell differentiation at a stage before Ig (immunoglobulin) gene rearrangement but after commitment of cells to the B-lymphoid lineage. PMID:7542362

  17. Setd1a regulates progenitor B-cell-to-precursor B-cell development through histone H3 lysine 4 trimethylation and Ig heavy-chain rearrangement.

    PubMed

    Tusi, Betsabeh Khoramian; Deng, Changwang; Salz, Tal; Zeumer, Leilani; Li, Yangqiu; So, Chi Wai Eric; Morel, Laurence M; Qiu, Yi; Huang, Suming

    2015-04-01

    SETD1A is a member of trithorax-related histone methyltransferases that methylate lysine 4 at histone H3 (H3K4). We showed previously that Setd1a is required for mesoderm specification and hematopoietic lineage differentiation in vitro. However, it remains unknown whether or not Setd1a controls specific hematopoietic lineage commitment and differentiation during animal development. Here, we reported that homozygous Setd1a knockout (KO) mice are embryonic lethal. Loss of the Setd1a gene in the hematopoietic compartment resulted in a blockage of the progenitor B-cell-to-precursor B-cell development in bone marrow (BM) and B-cell maturation in spleen. The Setd1a-cKO (conditional knockout) mice exhibited an enlarged spleen with disrupted spleen architecture and leukocytopenia. Mechanistically, Setd1a deficiency in BM reduced the levels of H3K4me3 at critical B-cell gene loci, including Pax5 and Rag1/2, which are critical for the IgH (Ig heavy-chain) locus contractions and rearrangement. Subsequently, the differential long-range looped interactions of the enhancer E? with proximal 5' DH region and 3' regulatory regions as well as with Pax5-activated intergenic repeat elements and 5' distal VH genes were compromised by the Setd1a-cKO. Together, our findings revealed a critical role of Setd1a and its mediated epigenetic modifications in regulating the IgH rearrangement and B-cell development. PMID:25550471

  18. DOCK8 deficient patients have a breakdown in peripheral B cell tolerance and defective regulatory T cells

    PubMed Central

    Janssen, Erin; Morbach, Henner; Ullas, Sumana; Bannock, Jason M.; Massad, Christopher; Menard, Laurence; Barlan, Isil; Lefranc, Gerard; Su, Helen; Dasouki, Majed; Al-Herz, Waleed; Keles, Sevgi; Chatila, Talal; Geha, Raif S.; Meffre, Eric

    2014-01-01

    Background Dedicator of Cytokinesis 8 (DOCK8) deficiency is typified by recurrent infections, elevated serum IgE levels, eosinophilia, and a high incidence of allergic and autoimmune manifestations. Objective We sought to determine the role of DOCK8 in the establishment and maintenance of human B cell tolerance. Methods Autoantibodies were measured in the plasma of DOCK8 deficient patients. The antibody coding genes from new emigrant/transitional and mature naive B cells were cloned and assessed for their ability to bind self-antigens. Regulatory T (Treg) cells in the blood were analyzed by flow cytometry, and their function was tested by examining their capacity to inhibit the proliferation of CD4+CD25? T effector (Teff) cells. Results DOCK8 deficient patients had increased levels of autoantibodies in their plasma. We determined that central B cell tolerance did not require DOCK8 as evidenced by the normal low frequency of polyreactive new emigrant/transitional B cells in DOCK8 deficient patients. In contrast, autoreactive B cells were enriched in the mature naïve B cell compartment, revealing a defective peripheral B cell tolerance checkpoint. In addition, we found that Treg cells were decreased and exhibited impaired suppressive activity in DOCK8 deficient patients. Conclusions Our data support a critical role for DOCK8 in Treg cell homeostasis and function and the enforcement of peripheral B cell tolerance. Clinical Implications DOCK8 deficient patients should be evaluated for autoantibodies, the possible emergence of autoimmunity, and end organ damage. PMID:25218284

  19. Diagnosis of 'double hit' diffuse large B-cell lymphoma and B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma: when and how, FISH versus IHC.

    PubMed

    Swerdlow, Steven H

    2014-12-01

    Identification of large B-cell lymphomas that are "extra-aggressive" and may require therapy other than that used for diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), is of great interest. Large B-cell lymphomas with MYC plus BCL2 and/or BCL6 rearrangements, so-called 'double hit' (DHL) or 'triple hit' (THL) lymphomas, are one such group of cases often recognized using cytogenetic FISH studies. Whether features such as morphologic classification, BCL2 expression, or type of MYC translocation partner may mitigate the very adverse prognosis of DHL/THL is controversial. Classification of the DHL/THL is also controversial, with most either dividing them up between the DLBCL, NOS and B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma (BCLU) categories or classifying at least the majority as BCLU. The BCLU category itself has many features that overlap those of DHL/THL. Currently, there is growing interest in the use of MYC and other immunohistochemistry either to help screen for DHL/THL or to identify "double-expressor" (DE) large B-cell lymphomas, defined in most studies as having ?40% MYC+ and ?50%-70% BCL2+ cells. DE large B-cell lymphomas are generally aggressive, although not as aggressive as DHL/THL, are more common than DHL/THL, and are more likely to have a nongerminal center phenotype. Whether single MYC rearrangements or MYC expression alone is of clinical importance is controversial. The field of the DHL/THL and DE large B-cell lymphomas is becoming more complex, with many issues left to resolve; however, great interest remains in identifying these cases while more is learned about them. PMID:25696840

  20. Conditional Expression of E2A-HLF Induces B-Cell Precursor Death and Myeloproliferative-Like Disease in Knock-In Mice

    PubMed Central

    Duque-Afonso, Jesús; Smith, Kevin S.; Cleary, Michael L.

    2015-01-01

    Chromosomal translocations are driver mutations of human cancers, particularly leukemias. They define disease subtypes and are used as prognostic markers, for minimal residual disease monitoring and therapeutic targets. Due to their low incidence, several translocations and their biological consequences remain poorly characterized. To address this, we engineered mouse strains that conditionally express E2A-HLF, a fusion oncogene from the translocation t(17;19) associated with 1% of pediatric B-cell precursor ALL. Conditional oncogene activation and expression were directed to the B-cell compartment by the Cre driver promoters CD19 or Mb1 (Ig?, CD79a), or to the hematopoietic stem cell compartment by the Mx1 promoter. E2A-HLF expression in B-cell progenitors induced hyposplenia and lymphopenia, whereas expression in hematopoietic stem/progenitor cells was embryonic lethal. Increased cell death was detected in E2A-HLF expressing cells, suggesting the need for cooperating genetic events that suppress cell death for B-cell oncogenic transformation. E2A-HLF/Mb1.Cre aged mice developed a fatal myeloproliferative-like disorder with low frequency characterized by leukocytosis, anemia, hepatosplenomegaly and organ-infiltration by mature myelocytes. In conclusion, we have developed conditional E2A-HLF knock-in mice, which provide an experimental platform to study cooperating genetic events and further elucidate translational biology in cross-species comparative studies. PMID:26588248

  1. Quantifying evolutionary constraints on B-cell affinity maturation

    PubMed Central

    McCoy, Connor O.; Bedford, Trevor; Minin, Vladimir N.; Bradley, Philip; Robins, Harlan; Matsen, Frederick A.

    2015-01-01

    The antibody repertoire of each individual is continuously updated by the evolutionary process of B-cell receptor (BCR) mutation and selection. It has recently become possible to gain detailed information concerning this process through high-throughput sequencing. Here, we develop modern statistical molecular evolution methods for the analysis of B-cell sequence data, and then apply them to a very deep short-read dataset of BCRs. We find that the substitution process is conserved across individuals but varies significantly across gene segments. We investigate selection on BCRs using a novel method that side-steps the difficulties encountered by previous work in differentiating between selection and motif-driven mutation; this is done through stochastic mapping and empirical Bayes estimators that compare the evolution of in-frame and out-of-frame rearrangements. We use this new method to derive a per-residue map of selection, which provides a more nuanced view of the constraints on framework and variable regions. PMID:26194758

  2. Gaucher disease and comorbidities: B-cell malignancy and parkinsonism.

    PubMed

    Cox, Timothy M; Rosenbloom, Barry E; Barker, Roger A

    2015-07-01

    Data emerging from the International Collaborative Gaucher Group (ICGG) Gaucher Registry together with other contemporary clinical surveys have revealed a close association between Gaucher disease and non-Hodgkin's B-cell lymphoma and myeloma and Gaucher disease and Parkinson's disease. Several possible explanations for increased B-cell proliferation and neoplasia in Gaucher disease have been proposed, including the possible influence of sphingosine (derived from the extra lysosomal metabolism of glucosylceramide), gene modifiers, splenectomy and immune system deregulation induced by cytokines, chemokines, and hydrolases released from Gaucher cells. Parkinson's disease is frequently seen in the otherwise-healthy relatives of Gaucher disease patients leading to the finding that GBA mutations represent a genetic risk factor for Parkinson's disease. The mechanism of the association between GBA mutations and Parkinson's disease has yet to be elucidated but the pathogenesis appears distinct from that of Gaucher disease. Several pathogenic pathways have been proposed including lysosomal and/or mitochondrial dysfunction. The effect of Gaucher disease specific therapies on the incidence of cancer or Parkinson's disease are not clear and will likely be evaluated in future ICGG Gaucher Registry studies. PMID:26096744

  3. Targets for Ibrutinib Beyond B Cell Malignancies.

    PubMed

    Berglöf, A; Hamasy, A; Meinke, S; Palma, M; Krstic, A; Månsson, R; Kimby, E; Österborg, A; Smith, C I E

    2015-09-01

    Ibrutinib (Imbruvica™) is an irreversible, potent inhibitor of Bruton's tyrosine kinase (BTK). Over the last few years, ibrutinib has developed from a promising drug candidate to being approved by FDA for the treatment of three B cell malignancies, a truly remarkable feat. Few, if any medicines are monospecific and ibrutinib is no exception; already during ibrutinib's initial characterization, it was found that it could bind also to other kinases. In this review, we discuss the implications of such interactions, which go beyond the selective effect on BTK in B cell malignancies. In certain cases, the outcome of ibrutinib treatment likely results from the combined inhibition of BTK and other kinases, causing additive or synergistic, effects. Conversely, there are also examples when the clinical outcome seems unrelated to inhibition of BTK. Thus, more specifically, adverse effects such as enhanced bleeding or arrhythmias could potentially be explained by different interactions. We also predict that during long-term treatment bone homoeostasis might be affected due to the inhibition of osteoclasts. Moreover, the binding of ibrutinib to molecular targets other than BTK or effects on cells other than B cell-derived malignancies could be beneficial and result in new indications for clinical applications. PMID:26111359

  4. Cryptic B cell response to renal transplantation

    PubMed Central

    Lynch, R.J.; Silva, I.A.; Chen, B.J.; Punch, J.D.; Cascalho, M.; Platt, J.L.

    2013-01-01

    Renal transplantation reliably evokes allo-specific B cell and T cell responses in mice. Yet, human recipients of kidney transplants with normal function usually exhibit little or no antibody specific for the transplant donor during the early weeks and months after transplantation. Indeed, the absence of anti-donor antibodies is taken to reflect effective immunosuppressive therapy and to predict a favorable outcome. Whether the absence of donor-specific antibodies reflects absence of a B-cell response to the donor, tolerance to the donor or immunity masked by binding of donor-specific antibodies to the graft is not known. To distinguish between these possibilities, we devised a novel ELISPOT, using cultured donor, recipient and third-party fibroblasts as targets. We enumerated donor-specific antibody-secreting cells in the blood of nine renal allograft recipients with normal kidney function before and after transplantation. Although none of the nine subjects had detectable donor-specific antibodies before or after transplantation, all exhibited increases in the frequency of donor-specific antibody-secreting cells eight weeks after transplantation. The responses were directed against the donor HLA-class I antigens. The increase in frequency of donor-specific antibody-secreting cells after renal transplantation indicates that B cells respond specifically to the transplant donor more often than previously thought. PMID:23750851

  5. Efficient generation of antigen-specific cytotoxic T cells using retrovirally transduced CD40-activated B cells.

    PubMed

    Kondo, Eisei; Topp, Max S; Kiem, Hans-Peter; Obata, Yuichi; Morishima, Yasuo; Kuzushima, Kiyotaka; Tanimoto, Mitsune; Harada, Mine; Takahashi, Toshitada; Akatsuka, Yoshiki

    2002-08-15

    The development of rapid, efficient, and safe methods for generating Ag-specific T cells is necessary for the clinical application of adoptive immunotherapy. We show that B cells stimulated with CD40 ligand and IL-4 (CD40-B cells) can be efficiently transduced with retroviral vectors encoding a model Ag, CMV tegument protein pp65 gene, and maintain high levels of costimulatory molecules after gene transfer. CTL lines specific for pp65 were readily generated in all four healthy CMV-seropositive donors by stimulating autologous CD8(+) T cells with these transduced CD40-B cells, both of which were derived from 10 ml peripheral blood. ELISPOT assays revealed that the CTL lines used multiple HLA alleles as restricting elements. Thus, CD40-B cells transduced retrovirally with Ag-encoding cDNA can be potent APC and facilitate to generate Ag-specific CTL in vitro. PMID:12165546

  6. Gene expression profiling reveals different pathways related to Abl and other genes that cooperate with c-Myc in a model of plasma cell neoplasia

    PubMed Central

    Park, Eun Sung; Shaughnessy, John D; Gupta, Shalu; Wang, Hongyang; Lee, Ju-Seog; Woo, Hyun Goo; Zhan, Fenghuang; Owens, James D; Potter, Michael; Janz, Siegfried; Mushinski, J Frederic

    2007-01-01

    Background To elucidate the genes involved in the neoplastic transformation of B cells, global gene expression profiles were generated using Affymetrix U74Av2 microarrays, containing 12,488 genes, for four different groups of mouse B-cell lymphomas and six subtypes of pristane-induced mouse plasma cell tumors, three of which developed much earlier than the others. Results Unsupervised hierarchical cluster analysis exhibited two main sub-clusters of samples: a B-cell lymphoma cluster and a plasma cell tumor cluster with subclusters reflecting mechanism of induction. This report represents the first step in using global gene expression to investigate molecular signatures related to the role of cooperating oncogenes in a model of Myc-induced carcinogenesis. Within a single subgroup, e.g., ABPCs, plasma cell tumors that contained typical T(12;15) chromosomal translocations did not display gene expression patterns distinct from those with variant T(6;15) translocations, in which the breakpoint was in the Pvt-1 locus, 230 kb 3' of c-Myc, suggesting that c-Myc activation was the initiating factor in both. When integrated with previously published Affymetrix array data from human multiple myelomas, the IL-6-transgenic subset of mouse plasma cell tumors clustered more closely with MM1 subsets of human myelomas, slow-appearing plasma cell tumors clustered together with MM2, while plasma cell tumors accelerated by v-Abl clustered with the more aggressive MM3-MM4 myeloma subsets. Slow-appearing plasma cell tumors expressed Socs1 and Socs2 but v-Abl-accelerated plasma cell tumors expressed 4–5 times as much. Both v-Abl-accelerated and non-v-Abl-associated tumors exhibited phosphorylated STAT 1 and 3, but only v-Abl-accelerated plasma cell tumors lost viability and STAT 1 and 3 phosphorylation when cultured in the presence of the v-Abl kinase inhibitor, STI-571. These data suggest that the Jak/Stat pathway was critical in the transformation acceleration by v-Abl and that v-Abl activity remained essential throughout the life of the tumors, not just in their acceleration. A different pathway appears to predominate in the more slowly arising plasma cell tumors. Conclusion Gene expression profiling differentiates not only B-cell lymphomas from plasma cell tumors but also distinguishes slow from accelerated plasma cell tumors. These data and those obtained from the sensitivity of v-Abl-accelerated plasma cell tumors and their phosphorylated STAT proteins indicate that these similar tumors utilize different signaling pathways but share a common initiating genetic lesion, a c-Myc-activating chromosome translocation. PMID:17764563

  7. An autopsied case of T-cell rich B-cell lymphoma with general involvement.

    PubMed

    Tajima, K; Fukase, N; Shiono, T; Katagiri, T; Mito, S

    1995-04-01

    Autoptic findings of a 77-year-old man with T-cell-rich B-cell lymphoma (TCRBCL) showed predominant infiltration of reactive T-cells with a minority population of neoplastic B-cells in liver, spleen, pancreas, adrenal gland, stomach, small intestine and heart, as well as, lymph node. DNA studies demonstrated dual rearrangement in the T-cell receptor beta (TCR beta), immunoglobulin heavy chain J region (IgJH) and kappa light chain J region (IgJ kappa) genes. PMID:7606090

  8. Anti-cancer activity of withaferin A in B-cell lymphoma.

    PubMed

    McKenna, M K; Gachuki, B W; Alhakeem, S S; Oben, K N; Rangnekar, V M; Gupta, R C; Bondada, S

    2015-01-01

    Withaferin A (WA), a withanolide from the plant, Ashwagandha (Withania somnifera) used in Ayurvedic medicine, has been found to be valuable in the treatment of several medical ailments. WA has been found to have anticancer activity against various solid tumors, but its effects on hematological malignancies have not been studied in detail. WA strongly inhibited the survival of several human and murine B cell lymphoma cell lines. Additionally, in vivo studies with syngeneic-graft lymphoma cells suggest that WA inhibits the growth of tumor but does not affect other proliferative tissues. We demonstrate that WA inhibits the efficiency of NF-?B nuclear translocation in diffuse large B cell lymphomas and found that WA treatment resulted in a significant decrease in protein levels involved in B cell receptor signaling and cell cycle regulation. WA inhibited the activity of heat shock protein (Hsp) 90 as reflected by a sharp increase in Hsp70 expression levels. Hence, we propose that the anti-cancer effects of WA in lymphomas are likely due to its ability to inhibit Hsp90 function and subsequent reduction of critical kinases and cell cycle regulators that are clients of Hsp90. PMID:26020511

  9. A novel Robertsonian translocation event leads to transfer of a stem rust resistance gene (Sr52) effective against race Ug99 from Dasypyrum villosum into bread wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem rust (Puccinia graminis f. sp. tritici Eriks. & E. Henn.) (the causal agent of wheat stem rust) race Ug99 (also designated TTKSK) and its derivatives have defeated several important stem rust resistance genes widely used in wheat (Triticum aestivum L.) production, rendering much of the worldwid...

  10. ETV6/RUNX1 Induces Reactive Oxygen Species and Drives the Accumulation of DNA Damage in B Cells1 2

    PubMed Central

    Kantner, Hans-Peter; Warsch, Wolfgang; Delogu, Alessio; Bauer, Eva; Esterbauer, Harald; Casanova, Emilio; Sexl, Veronika; Stoiber, Dagmar

    2013-01-01

    The t(12;21)(p13;q22) chromosomal translocation is the most frequent translocation in childhood B cell precursor-acute lymphoblastic leukemia and results in the expression of an ETV6/RUNX1 fusion protein. The frequency of ETV6/RUNX1 fusions in newborns clearly exceeds the leukemia rate revealing that additional events occur in ETV6/RUNX1-positive cells for leukemic transformation. Hitherto, the mechanisms triggering these second hits remain largely elusive. Thus, we generated a novel ETV6/RUNX1 transgenic mouse model where the expression of the fusion protein is restricted to CD19+ B cells. These animals harbor regular B cell development and lack gross abnormalities. We established stable pro-B cell lines carrying the ETV6/RUNX1 transgene that allowed us to investigate whether ETV6/RUNX1 itself favors the acquisition of second hits. Remarkably, these pro-B cell lines as well as primary bone marrow cells derived from ETV6/RUNX1 transgenic animals display elevated levels of reactive oxygen species (ROS) as tested with ETV6/RUNX1 transgenic dihydroethidium staining. In line, intracellular phospho-histone H2AX flow cytometry and comet assay revealed increased DNA damage indicating that ETV6/RUNX1 expression enhances ROS. On the basis of our data, we propose the following model: the expression of ETV6/RUNX1 creates a preleukemic clone and leads to increased ROS levels. These elevated ROS favor the accumulation of secondary hits by increasing genetic instability and double-strand breaks, thus allowing preleukemic clones to develop into fully transformed leukemic cells. PMID:24339741

  11. ETV6/RUNX1 induces reactive oxygen species and drives the accumulation of DNA damage in B cells.

    PubMed

    Kantner, Hans-Peter; Warsch, Wolfgang; Delogu, Alessio; Bauer, Eva; Esterbauer, Harald; Casanova, Emilio; Sexl, Veronika; Stoiber, Dagmar

    2013-11-01

    The t(12;21)(p13;q22) chromosomal translocation is the most frequent translocation in childhood B cell precursor-acute lymphoblastic leukemia and results in the expression of an ETV6/RUNX1 fusion protein. The frequency of ETV6/RUNX1 fusions in newborns clearly exceeds the leukemia rate revealing that additional events occur in ETV6/RUNX1-positive cells for leukemic transformation. Hitherto, the mechanisms triggering these second hits remain largely elusive. Thus, we generated a novel ETV6/RUNX1 transgenic mouse model where the expression of the fusion protein is restricted to CD19(+) B cells. These animals harbor regular B cell development and lack gross abnormalities. We established stable pro-B cell lines carrying the ETV6/RUNX1 transgene that allowed us to investigate whether ETV6/RUNX1 itself favors the acquisition of second hits. Remarkably, these pro-B cell lines as well as primary bone marrow cells derived from ETV6/RUNX1 transgenic animals display elevated levels of reactive oxygen species (ROS) as tested with ETV6/RUNX1 transgenic dihydroethidium staining. In line, intracellular phospho-histone H2AX flow cytometry and comet assay revealed increased DNA damage indicating that ETV6/RUNX1 expression enhances ROS. On the basis of our data, we propose the following model: the expression of ETV6/RUNX1 creates a preleukemic clone and leads to increased ROS levels. These elevated ROS favor the accumulation of secondary hits by increasing genetic instability and double-strand breaks, thus allowing preleukemic clones to develop into fully transformed leukemic cells. PMID:24339741

  12. Gastrointestinal B-cell lymphomas: From understanding B-cell physiology to classification and molecular pathology.

    PubMed

    Sagaert, Xavier; Tousseyn, Thomas; Yantiss, Rhonda K

    2012-12-15

    The gut is the most common extranodal site where lymphomas arise. Although all histological lymphoma types may develop in the gut, small and large B-cell lymphomas predominate. The sometimes unexpected finding of a lymphoid lesion in an endoscopic biopsy of the gut may challenge both the clinician (who is not always familiar with lymphoma pathogenesis) and the pathologist (who will often be hampered in his/her diagnostic skill by the limited amount of available tissue). Moreover, the past 2 decades have spawned an avalanche of new data that encompasses both the function of the reactive B-cell as well as the pathogenic pathways that lead to its neoplastic counterpart, the B-cell lymphoma. Therefore, this review aims to offer clinicians an overview of B-cell lymphomas in the gut, and their pertinent molecular features that have led to new insights regarding lymphomagenesis. It addresses the question as how to incorporate all presently available information on normal and neoplastic B-cell differentiation, and how this knowledge can be applied in daily clinical practice (e.g., diagnostic tools, prognostic biomarkers or therapeutic targets) to optimalise the managment of this heterogeneous group of neoplasms. PMID:23443141

  13. B-cell repertoire responses to varicella-zoster vaccination in human identical twins.

    PubMed

    Wang, Chen; Liu, Yi; Cavanagh, Mary M; Le Saux, Sabine; Qi, Qian; Roskin, Krishna M; Looney, Timothy J; Lee, Ji-Yeun; Dixit, Vaishali; Dekker, Cornelia L; Swan, Gary E; Goronzy, Jörg J; Boyd, Scott D

    2015-01-13

    Adaptive immune responses in humans rely on somatic genetic rearrangements of Ig and T-cell receptor loci to generate diverse antigen receptors. It is unclear to what extent an individual's genetic background affects the characteristics of the antibody repertoire used in responding to vaccination or infection. We studied the B-cell repertoires and clonal expansions in response to attenuated varicella-zoster vaccination in four pairs of adult identical twins and found that the global antibody repertoires of twin pair members showed high similarity in antibody heavy chain V, D, and J gene segment use, and in the length and features of the complementarity-determining region 3, a major determinant of antigen binding. These twin similarities were most pronounced in the IgM-expressing B-cell pools, but were seen to a lesser extent in IgG-expressing B cells. In addition, the degree of antibody somatic mutation accumulated in the B-cell repertoire was highly correlated within twin pair members. Twin pair members had greater numbers of shared convergent antibody sequences, including mutated sequences, suggesting similarity among memory B-cell clonal lineages. Despite these similarities in the memory repertoire, the B-cell clones used in acute responses to ZOSTAVAX vaccination were largely unique to each individual. Taken together, these results suggest that the overall B-cell repertoire is significantly shaped by the underlying germ-line genome, but that stochastic or individual-specific effects dominate the selection of clones in response to an acute antigenic stimulus. PMID:25535378

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

    PubMed

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

    2016-01-01

    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. In this study, 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 T cells in the thymus. In spleen, Fng tKO mice had reduced frequencies of CD4(+), CD8(+), central memory T cells and MZ B cells, and an increased frequency of effector memory T cells, neutrophils, follicular, 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 LPS gave reduced proliferation compared with 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

  15. De Novo microdeletion on an inherited Robertsonian translocation chromosome: A cause for dysmorphism in the apparently balanced translocation carrier

    SciTech Connect

    Bonthron, D.T.; Smith, S.J.L.; Fantes, J.; Gosden, C.M.

    1993-09-01

    Robertsonian translocations are usually ascertained through abnormal children, making proposed phenotypic effects of apparently balanced translocations difficult to study in an unbiased way. From molecular genetic studies, though, some apparently balanced rearrangments are now known to be associated with phenotypic abnormalities resulting from uniparental disomy. Molecular explanations for other cases in which abnormality is seen in a balanced translocation carrier are being sought. In the present paper, an infant is described who has retarded growth, developmental delay, gross muscular hypotonia, slender habitus, frontal bossing, micrognathia, hooked nose, abundant wispy hair, and blue sclerae. Cytogenetically, she appeared to be a carrier of a balanced, paternally derived 14;21 Robertsonian translocation. Analysis of DNA polymorphisms showed that she had no paternal allele at the D14S13 locus (14q32). Study of additional DNA markers within 14q32 revealed that her previously undescribed phenotype results from an interstitial microdeletion within 14q32. Fluorescent in situ hybridization was used to show that this microdeletion had occurred de novo on the Robertsonian translocation chromosome. These observations may reactivate old suspicions of a causal association between Robertsonian translocations and de novo rearrangements in offspring; a systematic search for similar subcytogentic rearrangements in other families, in which there are phenotypically abnormal children with apparently balanced translocations, may be fruitful. The clinical and molecular genetic data presented also define a new contiguous gene syndrome due to interstitial 14q32 deletion. 42 refs., 4 figs., 1 tab.

  16. Non-Hematopoietic and Hematopoietic SIRP? Signaling Differently Regulates Murine B Cell Maturation in Bone Marrow and Spleen

    PubMed Central

    Kolan, Shrikant Shantilal; Lejon, Kristina; Koskinen Holm, Cecilia; Sulniute, Rima; Lundberg, Pernilla; Matozaki, Takashi; Oldenborg, Per-Arne

    2015-01-01

    B lymphocyte development occurs in the bone marrow, while final differentiation and maturation can occur in both the bone marrow and the spleen. Here we provide evidence that signal regulatory protein ? (SIRP?), an Ig-superfamily ITIM-receptor expressed by myeloid but not by lymphoid cells, is involved in regulating B cell maturation. Lack of SIRP? signaling in adult SIRP?-mutant mice resulted in a reduced maturation of B cells in the bone marrow, evident by reduced numbers of semi-mature IgD+IgMhi follicular type-II (F-II) and mature IgD+IgMlo follicular type-I (F-I) B cells, as well as reduced blood B cell numbers. In addition, lack of SIRP? signaling also impaired follicular B cell maturation in the spleen. Maturing BM or splenic B cells of SIRP?-mutant mice were found to express higher levels of the pro-apoptotic protein BIM and apoptosis was increased among these B cells. Bone marrow reconstitution experiments revealed that the B cell maturation defect in bone marrow and blood was due to lack of SIRP? signaling in non-hematopoietic cells, while hematopoietic SIRP? signaling was important for follicular B cell maturation in the spleen. Adding on to our previous findings of a stromal cell defect in SIRP?-mutant mice was the finding that gene expression of receptor activator of nuclear factor-?B ligand (RANKL) was significantly lower in cultured bone marrow stromal cells of SIRP? mutant mice. These data suggest a novel and opposite contribution of SIRP? signaling within non-hematopoietic and hematopoietic cells, respectively, to maintain B cell maturation and to prevent apoptosis in the bone marrow and spleen of adult mice. PMID:26222253

  17. Enhancer repertoires are reshaped independently of early priming and heterochromatin dynamics during B cell differentiation

    PubMed Central

    Choukrallah, Mohamed-Amin; Song, Shuang; Rolink, Antonius G.; Burger, Lukas; Matthias, Patrick

    2015-01-01

    A widely accepted model posits that activation of enhancers during differentiation goes through a priming step prior to lineage commitment. To investigate the chronology of enhancer repertoire establishment during hematopoiesis, we monitored epigenome dynamics during three developmental stages representing hematopoietic stem cells, B-cell progenitors and mature B-cells. We find that only a minority of enhancers primed in stem cells or progenitors become active at later stages. Furthermore, most enhancers active in differentiated cells were not primed in earlier stages. Thus, the enhancer repertoire is reshaped dynamically during B-cell differentiation and enhancer priming in early stages does not appear to be an obligate step for enhancer activation. Furthermore, our data reveal that heterochromatin and Polycomb-mediated silencing have only a minor contribution in shaping enhancer repertoires during cell differentiation. Together, our data revisit the prevalent model about epigenetic reprogramming during hematopoiesis and give insights into the formation of gene regulatory networks. PMID:26477271

  18. Enhancer repertoires are reshaped independently of early priming and heterochromatin dynamics during B cell differentiation.

    PubMed

    Choukrallah, Mohamed-Amin; Song, Shuang; Rolink, Antonius G; Burger, Lukas; Matthias, Patrick

    2015-01-01

    A widely accepted model posits that activation of enhancers during differentiation goes through a priming step prior to lineage commitment. To investigate the chronology of enhancer repertoire establishment during hematopoiesis, we monitored epigenome dynamics during three developmental stages representing hematopoietic stem cells, B-cell progenitors and mature B-cells. We find that only a minority of enhancers primed in stem cells or progenitors become active at later stages. Furthermore, most enhancers active in differentiated cells were not primed in earlier stages. Thus, the enhancer repertoire is reshaped dynamically during B-cell differentiation and enhancer priming in early stages does not appear to be an obligate step for enhancer activation. Furthermore, our data reveal that heterochromatin and Polycomb-mediated silencing have only a minor contribution in shaping enhancer repertoires during cell differentiation. Together, our data revisit the prevalent model about epigenetic reprogramming during hematopoiesis and give insights into the formation of gene regulatory networks. PMID:26477271

  19. Limited junctional diversity in kappa light chains. Junctional sequences from CD43+B220+ early B cell progenitors resemble those from peripheral B cells.

    PubMed

    Victor, K D; Vu, K; Feeney, A J

    1994-04-01

    Among all adult T and B cell Ag receptor chains, only Ig light chains lack N regions. It is thought that this is due to the fact that light chain genes rearrange after heavy chain genes, and that terminal deoxynucleotidyl transferase, the enzyme that adds N regions, is not longer expressed at that stage. However, this concept has been challenged recently by the demonstration that 3 to 10% of B cell precursors (CD43+B220+) appear to rearrange their light chains at approximately the same time as they undergo VH-->DJ rearrangements. To examine N region addition in B cell precursors undergoing early kappa-chain rearrangement, we PCR amplified rearranged V kappa 21 genes from the CD43+B220+ bone marrow cells and compared them to sequences obtained from whole bone marrow and spleen. Unexpectedly, all three populations showed approximately 10% N region containing junctions, most consisting of only one N nucleotide. Thus, even the B cell precursors that rearrange light chains at this early stage of development lack much N region diversity. Twelve percent of the sequences unambiguously contained P regions, which were from 1 to 5 nucleotides in length. All but 2 of the 41 productive rearrangements had the commonly observed CDR3 length of nine amino acids. Many (71%) of the sequences were out of frame. CDR3 length was very restricted in nonproductive rearrangements too, and deletion of nucleotides from V kappa and J kappa gene segments was limited. Thus, even at the level of nonproductive rearrangements, junctional diversity is minimal for kappa-chains. PMID:7511648

  20. The gene for human erythrocyte membrane protein band 7. 2 (EPB72) maps to 9q33-q34 centromeric to the Philadelphia chromosome translocation breakpoint region

    SciTech Connect

    Gallagher, P.G.; Upender, M.; Ward, D.C.; Forget, B.G. )

    1993-10-01

    Erthrocyte band 7.2b is a 31-kDa integral phosphoprotein absent from the erythrocytes of many patients with hereditary stomatocytosis (HSt). HSt is a heterogeneous group of disorders characterized by mouth-shaped erythrocyte morphology on peripheral blood smears. The clinical severity of HSt is variable; some patients experience hemolysis and anemia while others are asymptomatic. The red cell membranes of these patients usually exhibit abnormal permeability to sodium and potassium with resultant modification of intracellular water content. The band 7.2b protein has been purified and the cDNA cloned. The approved gene name and symbol are erythrocyte membrane protein band 7.2 and EPB72, respectively, as assigned by the Human Gene Nomenclature Committee. Using a human reticulocyte cDNA library as template, a 491-bp fragment corresponding to the 3' end of the coding region of the EPB72 cDNA was amplified. Three overlapping phase DNA clones were isolated using this probe. Four genomic DNA fragments of 2.0, 2.5, 4.5, and 5.0 kb, respectively, were isolated from these clones. To localize the EPB72 gene by fluorescence in situ hybridization, these genomic DNA fragments were labeled with biotin-11-dUTP and hybridized to metaphase chromosomes as described. Probes were preannealed to C[sub 0]t1-fractionated DNA to block repetitive sequences. Experiments were analyzed and digitally imaged using a cooled CCD camera. The probes, in combination, gave specific hybridization signals only in chromosome 9q. The gene for erythrocyte membrane protein 7.2 localized to 9q33-q34.

  1. Cloning and Characterisation of Two H+ Translocating Organic Pyrophos-phatase Genes in Salix and Their Expression Differences in Two Willow Varieties with Different Salt Tolerances

    PubMed Central

    Li, Min; Yu, Chunmei; Wang, Yaoyi; Li, Wentao; Wang, Ying; Yang, Yun; Liu, Huihui; Li, Yujuan; Tan, Feng; Zhang, Jian

    2014-01-01

    Willows are one of the most important tree species for landscaping, biofuel and raw timber. Screening salt-tolerant willow varieties is an effective approach to balance wood supply and demand. However, more salt-tolerant willow varieties are required and little is known regarding the mechanism of salt tolerance at the gene expression level. In this paper, two willow varieties were studies in terms of their differences in salt-tolerances and mechanism of salt tolerance at the level of VP1 gene expression. The results showed that Salix L0911 (L0911) had higher biomass than Salix matsudana (SM), and salt injuries were less severe in L0911 than in SM. The activities of peroxidase and superoxide dismutase, as well as the contents of soluble protein and proline, were higher in L0911 than in SM, whereas the contents of Na+ and K+, as well as the Na+/K+ ratio, were lower in L0911 than in SM. Two VP1 genes (VP1.1 and VP1.2) cloned in L0911 and SM had similar sequences and structures. VP1.1 and VP1.2 belonged to different subgroups. Total expression levels of the VP1.1 gene in both roots and leaves of L0911 were higher than that in SM under normal conditions. Under salt stress, expression of VP1 in SM roots initially increased and then decreased, whereas the expression of VP1 in leaves of L0911 and SM, as well as in roots of L0911, decreased with increasing salt concentrations. This study increased our understanding of the salt-tolerance mechanism of willow and may facilitate the selection of salt-tolerant willow resources. PMID:25435797

  2. Development of a Malignancy-Associated Proteomic Signature for Diffuse Large B-Cell Lymphoma

    PubMed Central

    Romesser, Paul B.; Perlman, David H.; Faller, Douglas V.; Costello, Catherine E.; McComb, Mark E.; Denis, Gerald V.

    2009-01-01

    The extreme pathological diversity of non-Hodgkin’s lymphomas has made their accurate histological assessment difficult. New diagnostics and treatment modalities are urgently needed for these lymphomas, particularly in drug development for cancer-specific targets. Previously, we showed that a subset of B cell lymphoma, diffuse large B cell lymphoma, may be characterized by two major, orthogonal axes of gene expression: one set of transcripts that is differentially expressed between resting and proliferating, nonmalignant cells (ie, a “proliferative signature”) and another set that is expressed only in proliferating malignant cells (ie, a “cancer signature”). A differential proteomic analysis of B cell proliferative states, similar to previous transcriptional profiling analyses, holds great promise either to reveal novel factors that participate in lymphomagenesis or to define biomarkers of onset or progression. Here, we use a murine model of diffuse large B cell lymphoma to conduct unbiased two-dimensional gel electrophoresis and mass spectrometry-based comparative proteomic analyses of malignant proliferating B cells and tissue-matched, normal resting, or normal proliferating cells. We show that the expression patterns of particular proteins or isoforms across these states fall into eight specific trends that provide a framework to identify malignancy-associated biomarkers and potential drug targets, a signature proteome. Our results support the central hypothesis that clusters of proteins of known function represent a panel of expression markers uniquely associated with malignancy and not normal proliferation. PMID:19498000

  3. Aging-associated inflammation promotes selection for adaptive oncogenic events in B cell progenitors.

    PubMed

    Henry, Curtis J; Casás-Selves, Matias; Kim, Jihye; Zaberezhnyy, Vadym; Aghili, Leila; Daniel, Ashley E; Jimenez, Linda; Azam, Tania; McNamee, Eoin N; Clambey, Eric T; Klawitter, Jelena; Serkova, Natalie J; Tan, Aik Choon; Dinarello, Charles A; DeGregori, James

    2015-12-01

    The incidence of cancer is higher in the elderly; however, many of the underlying mechanisms for this association remain unexplored. Here, we have shown that B cell progenitors in old mice exhibit marked signaling, gene expression, and metabolic defects. Moreover, B cell progenitors that developed from hematopoietic stem cells (HSCs) transferred from young mice into aged animals exhibited similar fitness defects. We further demonstrated that ectopic expression of the oncogenes BCR-ABL, NRASV12, or Myc restored B cell progenitor fitness, leading to selection for oncogenically initiated cells and leukemogenesis specifically in the context of an aged hematopoietic system. Aging was associated with increased inflammation in the BM microenvironment, and induction of inflammation in young mice phenocopied aging-associated B lymphopoiesis. Conversely, a reduction of inflammation in aged mice via transgenic expression of ?-1-antitrypsin or IL-37 preserved the function of B cell progenitors and prevented NRASV12-mediated oncogenesis. We conclude that chronic inflammatory microenvironments in old age lead to reductions in the fitness of B cell progenitor populations. This reduced progenitor pool fitness engenders selection for cells harboring oncogenic mutations, in part due to their ability to correct aging-associated functional defects. Thus, modulation of inflammation - a common feature of aging - has the potential to limit aging-associated oncogenesis. PMID:26551682

  4. B-cell anergy: from transgenic models to naturally occurring anergic B cells?

    PubMed Central

    Cambier, John C.; Gauld, Stephen B.; Merrell, Kevin T.; Vilen, Barbara J.

    2013-01-01

    Anergy, a condition in which cells persist in the periphery but are unresponsive to antigen, is responsible for silencing many self-reactive B cells. Loss of anergy is known to contribute to the development of autoimmune diseases, including systemic lupus erythematosus and type 1 diabetes. Multiple transgenic mouse models have enabled the dissection of mechanisms that underlie anergy, and recently, anergic B cells have been identified in the periphery of wild-type mice. Heterogeneity of mechanistic concepts developed using model systems has complicated our understanding of anergy and its biological features. In this Review, we compare and contrast the salient features of anergic B cells with a view to developing unifying mechanistic hypotheses that explain their lifestyles. PMID:17641666

  5. B cell-intrinsic TLR7 signaling is essential for the development of spontaneous germinal centers

    PubMed Central

    Soni, Chetna; Wong, Eric B.; Domeier, Phillip P.; Khan, Tahsin N.; Satoh, Takashi; Akira, Shizuo; Rahman, Ziaur S.M.

    2014-01-01

    Spontaneous germinal center (Spt-GC) B cells and follicular helper T cells (Tfh) generate high affinity autoantibodies involved in the development of systemic lupus erythematosus (SLE). Toll like receptors (TLRs) play a pivotal role in SLE pathogenesis. While previous studies have focused on the B cell intrinsic role of TLR-MyD88 signaling on immune activation, autoantibody repertoire and systemic inflammation, a thorough investigation of the mechanisms by which TLRs control the formation of Spt-GCs remains unclear. Using non-autoimmune C57BL/6 (B6) mice deficient in MyD88, TLR2, 3, 4, 7 or 9, we identified B cell-intrinsic TLR7 signaling as a prerequisite to Spt-GC formation without the confounding effects of autoimmune susceptibility genes and the overexpression of TLRs. TLR7 deficiency also rendered autoimmune B6.Sle1b mice unable to form Spt-GCs, leading to markedly decreased autoantibodies. Conversely, B6.yaa and B6.Sle1b.yaa mice expressing an extra copy of TLR7 and B6.Sle1b mice treated with a TLR7 agonist had increased Spt-GCs and Tfh. Further, TLR7/ MyD88 deficiency led to compromised B cell proliferation and survival after B cell stimulation both in vitro and in vivo. In contrast, TLR9 inhibited Spt-GC development. Our findings demonstrate an absolute requirement of TLR7 and a negative regulatory function for TLR9 in Spt-GC formation under non-autoimmune and autoimmune conditions. Our data suggest that, under non-autoimmune conditions, Spt-GCs initiated by TLR7 produce protective antibodies. However, in the presence of autoimmune susceptibility genes, TLR7 dependent Spt-GCs produce pathogenic autoantibodies. Thus, a single copy of TLR7 in B cells is the minimal requirement for breaking the GC-tolerance checkpoint. PMID:25252960

  6. Essential Function for the Nuclear Protein Akirin2 in B Cell Activation and Humoral Immune Responses.

    PubMed

    Tartey, Sarang; Matsushita, Kazufumi; Imamura, Tomoko; Wakabayashi, Atsuko; Ori, Daisuke; Mino, Takashi; Takeuchi, Osamu

    2015-07-15

    Akirin2, an evolutionarily conserved nuclear protein, is an important factor regulating inflammatory gene transcription in mammalian innate immune cells by bridging the NF-?B and SWI/SNF complexes. Although Akirin is critical for Drosophila immune responses, which totally rely on innate immunity, the mammalian NF-?B system is critical not only for the innate but also for the acquired immune system. Therefore, we investigated the role of mouse Akirin2 in acquired immune cells by ablating Akirin2 function in B lymphocytes. B cell-specific Akirin2-deficient (Cd19(Cre/+)Akirin2(fl/fl)) mice showed profound decrease in the splenic follicular (FO) and peritoneal B-1, but not splenic marginal zone (MZ), B cell numbers. However, both Akirin2-deficient FO and MZ B cells showed severe proliferation defect and are prone to undergo apoptosis in response to TLR ligands, CD40, and BCR stimulation. Furthermore, B cell cycling was defective in the absence of Akirin2 owing to impaired expression of genes encoding cyclin D and c-Myc. Additionally, Brg1 recruitment to the Myc and Ccnd2 promoter was severely impaired in Akirin2-deficient B cells. Cd19(Cre/+)Akirin2(fl/fl) mice showed impaired in vivo immune responses to T-dependent and -independent Ags. Collectively, these results demonstrate that Akirin2 is critical for the mitogen-induced B cell cycle progression and humoral immune responses by controlling the SWI/SNF complex, further emphasizing the significant function of Akirin2 not only in the innate, but also in adaptive immune cells. PMID:26041538

  7. Pathophysiology and molecular aspects of diffuse large B-cell lymphoma

    PubMed Central

    Gouveia, Gisele Rodrigues; Siqueira, Sheila Aparecida Coelho; Pereira, Juliana

    2012-01-01

    Diffuse large B-Cell lymphoma is the most common subtype of non-Hodgkin lymphoma in the West. In Brazil, it is the fifth cause of cancer, with more than 55,000 cases and 26,000 deaths per year. At Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - HCFMUSP, diffuse large B-Cell lymphoma represents 49.7% of all non-Hodgkin lymphoma cases. Initially, the classification of non-Hodgkin lymphoma was based on morphology, but advances in immunology and molecular medicine allowed the introduction of a biological classification for these diseases. As for other cancers, non-Hodgkin lymphoma involves patterns of multifactorial pathogenesis with environmental factors, as well as genetic, occupational and dietary factors, contributing to its development. Multiple lesions involving molecular pathways of B-cell proliferation and differentiation may result in the activation of oncogenes such as the BCL2, BCL6, and MYC genes and the inactivation of tumor suppressor genes such as p53 and INK4, as well as other important transcription factors such as OCT-1 and OCT-2. A dramatic improvement in survival was seen after the recent introduction of the anti-CD20 monoclonal antibody. The association of this antibody to the cyclophosphamide, hydroxydaunorubicin, oncovin and prednisolone (CHOP) regimen has increased overall survival of diffuse large B-Cell lymphoma and follicular lymphoma patients by 20%. However, 50% of all diffuse large B-Cell lymphoma patients remain incurable, creating a demand for more research with new advances in treatment. Thus, it is important to know and understand the key factors and molecular pathways involved in the pathogenesis of diffuse large B-Cell lymphoma. PMID:23323070

  8. Adhesins and Host Serum Factors Drive Yop Translocation by Yersinia into Professional Phagocytes during Animal Infection

    PubMed Central

    Maldonado-Arocho, Francisco J.; Green, Carlos; Fisher, Michael L.; Paczosa, Michelle K.; Mecsas, Joan

    2013-01-01

    Yersinia delivers Yops into numerous types of cultured cells, but predominantly into professional phagocytes and B cells during animal infection. The basis for this cellular tropism during animal infection is not understood. This work demonstrates that efficient and specific Yop translocation into phagocytes by Yersinia pseudotuberculosis (Yptb) is a multi-factorial process requiring several adhesins and host complement. When WT Yptb or a multiple adhesin mutant strain, ?ail?inv?yadA, colonized tissues to comparable levels, ?ail?inv?yadA translocated Yops into significantly fewer cells, demonstrating that these adhesins are critical for translocation into high numbers of cells. However, phagocytes were still selectively targeted for translocation, indicating that other bacterial and/or host factors contribute to this function. Complement depletion showed that complement-restricted infection by ?ail?inv?yadA but not WT, indicating that adhesins disarm complement in mice either by prevention of opsonophagocytosis or by suppressing production of pro-inflammatory cytokines. Furthermore, in the absence of the three adhesins and complement, the spectrum of cells targeted for translocation was significantly altered, indicating that Yersinia adhesins and complement direct Yop translocation into neutrophils during animal infection. In summary, these findings demonstrate that in infected tissues, Yersinia uses adhesins both to disarm complement-dependent killing and to efficiently translocate Yops into phagocytes. PMID:23818844

  9. Mutational and structural analysis of diffuse large B-cell lymphoma using whole genome sequencing | Office of Cancer Genomics

    Cancer.gov

    Abstract: Diffuse large B-cell lymphoma (DLBCL) is a genetically heterogeneous cancer comprising at least two molecular subtypes that differ in gene expression and distribution of mutations. Recently, application of genome/exome sequencing and RNA-seq to DLBCL has revealed numerous genes that are recurrent targets of somatic point mutation in this disease.

  10. Dynamics of B cells in germinal centres

    PubMed Central

    De Silva, Nilushi S.; Klein, Ulf

    2015-01-01

    Humoral immunity depends on the germinal centre (GC) reaction during which somatically mutated high-affinity memory B cells and plasma cells are generated. Recent studies have uncovered crucial cues that are required for the formation and the maintenance of GCs and for the selection of high-affinity antibody mutants. In addition, it is now clear that these events are promoted by the dynamic movements of cells within and between GCs. These findings have resolved the complexities of the GC reaction in greater detail than ever before. This Review focuses on these recent advances and discusses their implications for the establishment of humoral immunity. PMID:25656706

  11. Dengue Virus Directly Stimulates Polyclonal B Cell Activation

    PubMed Central

    Papa, Michelle Premazzi; de Morais, Ana Theresa Silveira; Peçanha, Ligia Maria Torres; de Arruda, Luciana Barros

    2015-01-01

    Dengue infection is associated to vigorous inflammatory response, to a high frequency of activated B cells, and to increased levels of circulating cross-reactive antibodies. We investigated whether direct infection of B cells would promote activation by culturing primary human B lymphocytes from healthy donors with DENV in vitro. B cells were susceptible, but poorly permissive to infection. Even though, primary B cells cultured with DENV induced substantial IgM secretion, which is a hallmark of polyclonal B cell activation. Notably, DENV induced the activation of B cells obtained from either DENV immune or DENV naïve donors, suggesting that it was not dependent on DENV-specific secondary/memory response. B cell stimulation was dependent on activation of MAPK and CD81. B cells cultured with DENV also secreted IL-6 and presented increased expression of CD86 and HLA-DR, which might contribute to B lymphocyte co-stimulatory function. Indeed, PBMCs, but not isolated B cells, secreted high amounts of IgG upon DENV culture, suggesting that interaction with other cell types in vivo might promote Ig isotype switching and IgG secretion from different B cell clones. These findings suggest that activation signaling pathways triggered by DENV interaction with non-specific receptors on B cells might contribute to the exacerbated response observed in dengue patients. PMID:26656738

  12. Intrarenal B Cell Cytokines Promote Transplant Fibrosis and Tubular Atrophy.

    PubMed

    Tse, G H; Johnston, C J C; Kluth, D; Gray, M; Gray, D; Hughes, J; Marson, L P

    2015-12-01

    Renal transplantation is the optimum treatment for end-stage renal failure. B cells have been identified in chronic allograft damage (CAD) and associated with the development of tertiary lymphoid tissue within the human renal allograft. We performed renal transplantation in mice to model CAD and identified B cells forming tertiary lymphoid tissue with germinal centers. Intra-allograft B220(+) B cells comprised of IgM(high) CD23(-) B cells, IgM(lo) CD23(+) B cells, and IgM(lo) CD23(-) B cells with elevated expression of CD86. Depletion of B cells with anti-CD20 was associated with an improvement in CAD but only when administered after transplantation and not before. Isolated intra-allograft B cells were cultured and shown to synthesize multiple cytokines, the most abundant of these were GRO-? (CXCL1), RANTES (CCL5), IL-6 and MCP-1 (CCL2). Tubular loss was observed with T cell accumulation within the allograft and development of interstitial fibrosis, whilst type III collagen deposition was observed in areas of F4/80(+) macrophages and PDGFR-?(+) and transgelin(+) fibroblasts, all of which were reduced by B cell depletion. We have shown that intra-allograft B cells are key mediators of CAD. B cells possibly contribute to CAD by intra-allograft secretion of cytokines and chemokines. PMID:26211786

  13. Association between tumor necrosis factor-? gene polymorphisms and diffuse large B-cell lymphoma in Chinese Han population: evidence from two center case-control study and a meta-analysis

    PubMed Central

    Yang, Cui; Wang, Wanling; Zi, Youmei; Han, Xiaolin; Qin, Xiaoxue; Li, Jingdong; Ren, Honggang

    2015-01-01

    Objectives: The tumor necrosis factor-? (TNF-?) gene, which plays crucial roles in tumorigenesis, is reported to be an independent marker for cancer. This study aims to examine the association between the TNF-? G308A polymorphism and DLBCL risk based on the two center case-control studies and meta-analysis. Methods: In the current study, we performed a two centers case-control study to investigate the effect of the TNF-? G308A polymorphism on DLBCL risk in Chinese Han population. A meta-analysis including 10 published datasets along with current dataset, including 111 comparisons containing 34,041 cases and 42,730 controls were enrolled, was next performed to further confirm the association after literature search was conducted and relevant studies were identified from PubMed, Embase, and Web of Science. Results: The TNF-? -308A allele was associated with a significantly increased DLBCL risk in the two independent patient case-control studies and additionally for pooled analysis from the two sets (P<0.05 for both). The result of meta-analysis further demonstrated that the A allele of -308A was significantly correlated with DLBCL risk under the allelic model (OR=1.35, 95% CI=1.27-1.44) without heterogeneity by fixed-effects model analysis (Q=17.30, P=0.139). Moreover, sensitivity analysis supported the robustness of this meta-analysis. Conclusion: This study suggested that -308A polymorphism may be associated with the susceptibility of DLBCL in a Chinese population. The further meta-analysis provides additional evidence supporting the above result that the risk allele of the -308A polymorphism may increase DLBCL risk. PMID:26722496

  14. The cnrY gene, a tool to monitor DNA rearrangements by IS translocation in Cupriavidus metallidurans CH34 in response to space flight

    NASA Astrophysics Data System (ADS)

    Leys, N.; Monchy, S.; Vallaeys, T.; Dams, A.; Mergeay, M.

    Background The beta -Proteobacterium Cupriavidus metallidurans CH34 carries a chromosome 3 9 Mb a megaplasmid 2 6 Mb and many different Mobile Genetic Elements MGEs including 2 large plasmids 234 kb and 170 kb and at least 1 genomic island 7 transposons and 13 IS elements Mobility and rearrangements of these MGEs could play a direct part in genome adaptation and evolution in response to environmental stresses such as space flight conditions Aim In this study a new tool was developed and tested to detect the mobility and functionality of the IS elements in response to environmental stresses such as space flight Method The cnrYXHCBAT gene cluster on the pMOL28 plasmid of CH34 Tibazarwa et al 2000 governs the efficient efflux of Co 2 and Ni 2 and a slight unspecific efflux of Zn 2 Mutations inactivating the cnrY gene 300 bp encoding an antisigma repressor protein allow a constitutive over-expression of nickel cobalt resistance Collard et al 1993 Such cnrY mutants can be positively selected when the medium is supplemented with 0 6mM Zn 2 ZnR mutants As functional test 35 independent cultures of CH34 were incubated on agar containing 0 6mM Zn 2 during 10 days in the International Space Station ISS and on corresponding control plates at the ground From these cultures in total ca 600 ZnR mutants were selected and the promoter- cnrY fragment was amplified and sequenced Result This study revealed that the

  15. A novel fusion 5'AFF3/3'BCL2 originated from a t(2;18)(q11.2;q21.33) translocation in follicular lymphoma.

    PubMed

    Impera, L; Albano, F; Lo Cunsolo, C; Funes, S; Iuzzolino, P; Laveder, F; Panagopoulos, I; Rocchi, M; Storlazzi, C T

    2008-10-16

    Follicular lymphoma is the second most frequent type of non-Hodgkin's lymphoma in adults. The basic molecular defect consists of the t(14;18)(q32;q21) translocation, juxtaposing the B-cell lymphoma protein 2 gene BCL2 to the immunoglobulin heavy chain locus IGH@, and leading to the antiapoptotic BCL2 protein overproduction. Variations in the t(14;18) are rare and can be classified into two categories: (i) simple variants, involving chromosomes 18 and 2, or 22, in which the fusion partner of BCL2 is the light-chain IGK@ or IGL@; (ii) complex variant translocations occurring among chromosomes 14, 18 and other chromosomes. We report a follicular lymphoma case showing BCL2 overexpression, detected by immunohistochemistry and real-time quantitative PCR, consequently to the formation of a novel fusion gene between the 5' of the lymphoid nuclear transcriptional activator gene AFF3 at 2q11.2, and the 3' of BCL2. This case shows evidence, for the first time, of BCL2 overexpression consequently to the fusion of BCL2 to a non-IG partner locus. PMID:18622426

  16. Long-term culture system for selective growth of human B-cell progenitors.

    PubMed Central

    Rawlings, D J; Quan, S G; Kato, R M; Witte, O N

    1995-01-01

    We describe a simple reproducible system for enrichment and long-term culture of human B-cell progenitors. Enriched CD34+ cord blood mononuclear cells are seeded onto a murine stromal cell line to establish a biphasic culture system. These cultures are characterized by transient growth of myeloid cells followed by outgrowth of cells highly enriched for early B-cell progenitors. Cultures consisting of > 90% early B-lineage cells [expressing CD10, CD19, CD38, and CD45 but lacking CD20, CD22, CD23, and surface IgM] are maintained for > 12 weeks without growth factor addition. Cells remain predominantly germ line at the immunoglobulin locus and express only low levels of cytoplasmic mu chain, terminal deoxynucleotidyltransferase, and recombination-activating gene 1 product. They are unresponsive to the pre-B-cell growth factors interleukin 7 or stem cell factor, or both, suggesting that growth support is provided by a cross-reactive murine stromal cell factor. Cultured B-cell progenitors are generated in large numbers ( > 10(8) cells from a typical cord blood specimen) suitable for use in biochemical analysis and gene-transfer studies. This system should be useful for study of normal and abnormal early human B-lymphopoiesis. Images Fig. 2 Fig. 3 Fig. 4 PMID:7533295

  17. Epigenetics of Peripheral B-Cell Differentiation and the Antibody Response

    PubMed Central

    Zan, Hong; Casali, Paolo

    2015-01-01

    Epigenetic modifications, such as histone post-translational modifications, DNA methylation, and alteration of gene expression by non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are heritable changes that are independent from the genomic DNA sequence. These regulate gene activities and, therefore, cellular functions. Epigenetic modifications act in concert with transcription factors and play critical roles in B cell development and differentiation, thereby modulating antibody responses to foreign- and self-antigens. Upon antigen encounter by mature B cells in the periphery, alterations of these lymphocytes epigenetic landscape are induced by the same stimuli that drive the antibody response. Such alterations instruct B cells to undergo immunoglobulin (Ig) class switch DNA recombination (CSR) and somatic hypermutation (SHM), as well as differentiation to memory B cells or long-lived plasma cells for the immune memory. Inducible histone modifications, together with DNA methylation and miRNAs modulate the transcriptome, particularly the expression of activation-induced cytidine deaminase, which is essential for CSR and SHM, and factors central to plasma cell differentiation, such as B lymphocyte-induced maturation protein-1. These inducible B cell-intrinsic epigenetic marks guide the maturation of antibody responses. Combinatorial histone modifications also function as histone codes to target CSR and, possibly, SHM machinery to the Ig loci by recruiting specific adaptors that can stabilize CSR/SHM factors. In addition, lncRNAs, such as recently reported lncRNA-CSR and an lncRNA generated through transcription of the S region that form G-quadruplex structures, are also important for CSR targeting. Epigenetic dysregulation in B cells, including the aberrant expression of non-coding RNAs and alterations of histone modifications and DNA methylation, can result in aberrant antibody responses to foreign antigens, such as those on microbial pathogens, and generation of pathogenic autoantibodies, IgE in allergic reactions, as well as B cell neoplasia. Epigenetic marks would be attractive targets for new therapeutics for autoimmune and allergic diseases, and B cell malignancies. PMID:26697022

  18. Regulation of B Cell Differentiation by Intracellular Membrane-Associated Proteins and microRNAs: Role in the Antibody Response

    PubMed Central

    Lou, Zheng; Casali, Paolo; Xu, Zhenming

    2015-01-01

    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, class switch DNA recombination (CSR)/somatic hypermutation (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 regulating 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. PMID:26579118

  19. Regulation of bifurcating B cell trajectories by mutual antagonism between transcription factors IRF4 and IRF8.

    PubMed

    Xu, Heping; Chaudhri, Virendra K; Wu, Zhiguo; Biliouris, Konstantinos; Dienger-Stambaugh, Krista; Rochman, Yrina; Singh, Harinder

    2015-12-01

    Upon recognition of antigen, B cells undertake a bifurcated response in which some cells rapidly differentiate into plasmablasts while others undergo affinity maturation in germinal centers (GCs). Here we identified a double-negative feedback loop between the transcription factors IRF4 and IRF8 that regulated the initial developmental bifurcation of activated B cells as well as the GC response. IRF8 dampened signaling via the B cell antigen receptor (BCR), facilitated antigen-specific interaction with helper T cells, and promoted antibody affinity maturation while antagonizing IRF4-driven differentiation of plasmablasts. Genomic analysis revealed concentration-dependent actions of IRF4 and IRF8 in regulating distinct gene-expression programs. Stochastic modeling suggested that the double-negative feedback was sufficient to initiate bifurcation of the B cell developmental trajectories. PMID:26437243

  20. Loss of Circulating CD4 T Cells with B Cell Helper Function during Chronic HIV Infection

    PubMed Central

    Boswell, Kristin L.; Paris, Robert; Boritz, Eli; Ambrozak, David; Yamamoto, Takuya; Darko, Sam; Wloka, Kaska; Wheatley, Adam; Narpala, Sandeep; McDermott, Adrian; Roederer, Mario; Haubrich, Richard; Connors, Mark; Ake, Julie; Douek, Daniel C.; Kim, Jerome; Petrovas, Constantinos; Koup, Richard A.

    2014-01-01

    The interaction between follicular T helper cells (TFH) and B cells in the lymph nodes and spleen has a major impact on the development of antigen-specific B cell responses during infection or vaccination. Recent studies described a functional equivalent of these cells among circulating CD4 T cells, referred to as peripheral TFH cells. Here, we characterize the phenotype and in vitro B cell helper activity of peripheral TFH populations, as well as the effect of HIV infection on these populations. In co-culture experiments we confirmed CXCR5+ cells from HIV-uninfected donors provide help to B cells and more specifically, we identified a CCR7highCXCR5highCCR6highPD-1high CD4 T cell population that secretes IL-21 and enhances isotype-switched immunoglobulin production. This population is significantly decreased in treatment-naïve, HIV-infected individuals and can be recovered after anti-retroviral therapy. We found impaired immunoglobulin production in co-cultures from HIV-infected individuals and found no correlation between the frequency of peripheral TFH cells and memory B cells, or with neutralization activity in untreated HIV infection in our cohort. Furthermore, we found that within the peripheral TFH population, the expression level of TFH-associated genes more closely resembles a memory, non-TFH population, as opposed to a TFH population. Overall, our data identify a heterogeneous population of circulating CD4 T cells that provides in vitro help to B cells, and challenges the origin of these cells as memory TFH cells. PMID:24497824

  1. Human B-cell cancer cell lines as a preclinical model for studies of drug effect in diffuse large B-cell lymphoma and multiple myeloma.

    PubMed

    Laursen, Maria Bach; Falgreen, Steffen; Bødker, Julie Støve; Schmitz, Alexander; Kjeldsen, Malene Krag; Sørensen, Suzette; Madsen, Jakob; El-Galaly, Tarec Christoffer; Bøgsted, Martin; Dybkær, Karen; Johnsen, Hans Erik

    2014-11-01

    Drug resistance in cancer refers to recurrent or primary refractory disease following drug therapy. At the cellular level, it is a consequence of molecular functions that ultimately enable the cell to resist cell death-one of the classical hallmarks of cancer. Thus, drug resistance is a fundamental aspect of the cancer cell phenotype, in parallel with sustained proliferation, immortality, angiogenesis, invasion, and metastasis. Here we present a preclinical model of human B-cell cancer cell lines used to identify genes involved in specific drug resistance. This process includes a standardized technical setup for specific drug screening, analysis of global gene expression, and the statistical considerations required to develop resistance gene signatures. The state of the art is illustrated by the first-step classical drug screen (including the CD20 antibody rituximab, the DNA intercalating topoisomerase II inhibitor doxorubicin, the mitotic inhibitor vincristine, and the alkylating agents cyclophosphamide and melphalan) along with the generation of gene lists predicting the chemotherapeutic outcome as validated retrospectively in clinical trial datasets. This B-cell lineage-specific preclinical model will allow us to initiate a range of laboratory studies, with focus on specific gene functions involved in molecular resistance mechanisms. PMID:25072621

  2. B cells from a distinct subset of patients with common variable immunodeficiency (CVID) have increased CD95 (Apo-1/fas), diminished CD38 expression, and undergo enhanced apoptosis.

    PubMed Central

    Saxon, A; Keld, B; Diaz-Sanchez, D; Guo, B C; Sidell, N

    1995-01-01

    We investigated the role of apoptosis in the differentiation failure of B cells from a selected subpopulation of patients with CVID delineated by B cell surface marker analysis, in vitro IgE response, and molecular markers of B cell VH gene repertoire. These patients had altered display of B cell surface molecules that play a role in apoptosis. The patients' B cells had a 4.5-250-fold increase in CD95 (Apo-1, fas) expression and increased CD95 display on their T cells. CD38, a molecule important in preventing germinal centre B cell apoptosis, was reduced on the patients' B cells. The expression of this molecule was inducible on the CVID lymphocytes with retinoic acid. Increased spontaneous apoptosis in vitro was observed with the patients' B (23%) and T cells (10%) compared with normal cells (13% and 3%, respectively). Stimulation in vitro with IL-4 and CD40 rescued the B cells from apoptosis and allowed for their differentiation. However, IL-4 plus alpha CD40-driven immunoglobulin production was not quantitatively or qualitatively normal. Failure to overcome apoptosis, a normal step in germinal centre B cell development, may be involved in the lack of differentiation seen in this subset of CVID patients. Images Fig. 1 PMID:7554385

  3. Entry of Francisella tularensis into Murine B Cells: The Role of B Cell Receptors and Complement Receptors

    PubMed Central

    Plzakova, Lenka; Krocova, Zuzana; Kubelkova, Klara; Macela, Ales

    2015-01-01

    Francisella tularensis, the etiological agent of tularemia, is an intracellular pathogen that dominantly infects and proliferates inside phagocytic cells but can be seen also in non-phagocytic cells, including B cells. Although protective immunity is known to be almost exclusively associated with the type 1 pathway of cellular immunity, a significant role of B cells in immune responses already has been demonstrated. Whether their role is associated with antibody-dependent or antibody-independent B cell functions is not yet fully understood. The character of early events during B cell–pathogen interaction may determine the type of B cell response regulating the induction of adaptive immunity. We used fluorescence microscopy and flow cytometry to identify the basic requirements for the entry of F. tularensis into B cells within in vivo and in vitro infection models. Here, we present data showing that Francisella tularensis subsp. holarctica strain LVS significantly infects individual subsets of murine peritoneal B cells early after infection. Depending on a given B cell subset, uptake of Francisella into B cells is mediated by B cell receptors (BCRs) with or without complement receptor CR1/2. However, F. tularensis strain FSC200 ?iglC and ?ftdsbA deletion mutants are defective in the ability to enter B cells. Once internalized into B cells, F. tularensis LVS intracellular trafficking occurs along the endosomal pathway, albeit without significant multiplication. The results strongly suggest that BCRs alone within the B-1a subset can ensure the internalization process while the BCRs on B-1b and B-2 cells need co-signaling from the co receptor containing CR1/2 to initiate F. tularensis engulfment. In this case, fluidity of the surface cell membrane is a prerequisite for the bacteria’s internalization. The results substantially underline the functional heterogeneity of B cell subsets in relation to F. tularensis. PMID:26161475

  4. Entry of Francisella tularensis into Murine B Cells: The Role of B Cell Receptors and Complement Receptors.

    PubMed

    Plzakova, Lenka; Krocova, Zuzana; Kubelkova, Klara; Macela, Ales

    2015-01-01

    Francisella tularensis, the etiological agent of tularemia, is an intracellular pathogen that dominantly infects and proliferates inside phagocytic cells but can be seen also in non-phagocytic cells, including B cells. Although protective immunity is known to be almost exclusively associated with the type 1 pathway of cellular immunity, a significant role of B cells in immune responses already has been demonstrated. Whether their role is associated with antibody-dependent or antibody-independent B cell functions is not yet fully understood. The character of early events during B cell-pathogen interaction may determine the type of B cell response regulating the induction of adaptive immunity. We used fluorescence microscopy and flow cytometry to identify the basic requirements for the entry of F. tularensis into B cells within in vivo and in vitro infection models. Here, we present data showing that Francisella tularensis subsp. holarctica strain LVS significantly infects individual subsets of murine peritoneal B cells early after infection. Depending on a given B cell subset, uptake of Francisella into B cells is mediated by B cell receptors (BCRs) with or without complement receptor CR1/2. However, F. tularensis strain FSC200 ?iglC and ?ftdsbA deletion mutants are defective in the ability to enter B cells. Once internalized into B cells, F. tularensis LVS intracellular trafficking occurs along the endosomal pathway, albeit without significant multiplication. The results strongly suggest that BCRs alone within the B-1a subset can ensure the internalization process while the BCRs on B-1b and B-2 cells need co-signaling from the co receptor containing CR1/2 to initiate F. tularensis engulfment. In this case, fluidity of the surface cell membrane is a prerequisite for the bacteria's internalization. The results substantially underline the functional heterogeneity of B cell subsets in relation to F. tularensis. PMID:26161475

  5. Detection of Kinase Translocation Using Microfluidic Electroporative Flow Cytometry

    NASA Astrophysics Data System (ADS)

    Lu, Chang; Wang, Jun; Bao, Ning; Paris, Leela; Wang, Hsiang-Yu; Geahlen, Robert

    2008-03-01

    Translocation of a protein between different subcellular compartments is a common event during signal transduction in living cells. Detection of these events has been largely carried out based on imaging of a low number of cells and subcellular fractionation/Western blotting. These conventional techniques either lack the high throughput desired for probing an entire cell population or provide only the average behaviors of cell populations without information from single cells. Here we demonstrate a new tool, referred to as microfluidic electroporative flow cytometry, to detect the translocation of an EGFP-tagged tyrosine kinase, Syk, to the plasma membrane in B cells at the level of the cell population. We combine electroporation with flow cytometry and observe the release of intracellular kinase out of the cells during electroporation. We found that the release of the kinase was strongly influenced by its subcellular localization. Cells stimulated through the antigen receptor have a fraction of the kinase at the plasma membrane and retain more kinase after electroporation than do cells without stimulation and translocation. This tool will have utility for kinase-related drug discovery and tumor diagnosis and staging.

  6. Scrapie Pathogenesis in Subclinically Infected B-Cell-Deficient Mice

    PubMed Central

    Frigg, Rico; Klein, Michael A.; Hegyi, Ivan; Zinkernagel, Rolf M.; Aguzzi, Adriano

    1999-01-01

    Prion infections can present without clinical manifestations. B-cell deficiency may be a model for subclinical transmissible spongiform encephalopathy, since it protects mice from disease upon intraperitoneal administration of scrapie prions; however, a proportion of B-cell-deficient mice accumulate protease-resistant prion protein in their brains. Here, we have characterized this subclinical disease. In addition, we have studied the possibility that a neurotoxic factor secreted by B cells may contribute to pathogenesis. PMID:10516067

  7. Translating transitions – how to decipher peripheral human B cell development

    PubMed Central

    Bemark, Mats

    2015-01-01

    Abstract During the last two decades our understanding of human B cell differentiation has developed considerably. Our understanding of the human B cell compartment has advanced from a point where essentially all assays were based on the presence or not of class-switched antibodies to a level where a substantial diversity is appreciated among the cells involved. Several consecutive transitional stages that newly formed IgM expressing B cells go through after they leave the bone marrow, but before they are fully mature, have been described, and a significant complexity is also acknowledged within the IgM expressing and class-switched memory B cell compartments. It is possible to isolate plasma blasts in blood to follow the formation of plasma cells during immune responses, and the importance and uniqueness of the mucosal IgA system is now much more appreciated. Current data suggest the presence of at least one lineage of human innate-like B cells akin to B1 and/or marginal zone B cells in mice. In addition, regulatory B cells with the ability to produce IL-10 have been identified. Clinically, B cell depletion therapy is used for a broad range of conditions. The ability to define different human B cell subtypes using flow cytometry has therefore started to come into clinical use, but as our understanding of human B cell development further progresses, B cell subtype analysis will be of increasing importance in diagnosis, to measure the effect of immune therapy and to understand the underlying causes for diseases. In this review the diversity of human B cells will be discussed, with special focus on current data regarding their phenotypes and functions. PMID:26243514

  8. The development and function of thymic B cells.

    PubMed

    Perera, Jason; Huang, Haochu

    2015-07-01

    Thymic B cells are a unique population of B lymphocytes that reside at the cortico-medullary junction of the thymus, an organ that is specialized for the development and selection of T cells. These B cells are distinct from peripheral B cells both in terms of their origin and phenotype. Multiple lines of evidence suggest that they develop within the thymus from B lineage-committed progenitors and are not recirculating peripheral B cells. Furthermore, thymic B cells have a highly activated phenotype. Because of their location in the thymic medulla, they have been thought to play a role in T cell negative selection. Thymic B cells are capable of inducing negative selection in a number of model antigen systems, including viral super antigen, peptides from immunoglobulin, and cognate self antigen presented by B cell receptor-mediated uptake. These findings establish thymic B cells as a novel and important population to study; however, much work remains to be done to understand how all of these unique aspects of thymic B cell biology inform their function. PMID:25837998

  9. Notch activity synergizes with B-cell-receptor and CD40 signaling to enhance B-cell activation.

    PubMed

    Thomas, Matthew; Calamito, Marco; Srivastava, Bhaskar; Maillard, Ivan; Pear, Warren S; Allman, David

    2007-04-15

    How diverse environmental cues are integrated to regulate B-cell activation and development remains poorly understood. Here we show that Notch activity synergizes with B-cell receptor (BCR) and/or CD40 signaling to enhance several aspects of B-cell activation and function. We find that costimulation of follicular B cells with the Notch ligand Delta-like-1 leads to significant increases in BCR- and CD40-mediated proliferation and enhances production of IgG1(+) cells in vitro and in vivo. We further find that coengagement of Notch and the BCR results in increased activation of the MAPK pathway, and MAPK and Notch inhibitors prevent B-cell activation events mediated by coengagement of Notch and the BCR. These data suggest that the BCR and CD40 signaling pathways collaborate with the Notch pathway to optimize B-cell activation. PMID:17179224

  10. Polymer translocation induced by adsorption

    E-print Network

    Pyeong Jun Park; Wokyung Sung

    1998-02-10

    We study the translocation of a flexible polymer through a pore in a membrane induced by its adsorption on \\trans side of the membrane. When temperature $T$ is higher than $T_c$, the adsorption-desorption transition temperature, attractive interaction between polymer and membrane plays little role in affecting polymer conformation, leading to translocation time that scales as $\\tau\\sim L^3$ where $L$ is the polymer contour length. When $T < T_c$, however, the translocation time undergoes a sharp crossover to $\\tau\\sim L^2$ for sufficiently long polymers, following the second order conformational (adsorption) transition. The translocation time is found to exhibit the crossover around $T=T_c'$, which is lower than $T_c$ for polymers shorter than a critical length($N

  11. Abdominal radiation causes bacterial translocation

    SciTech Connect

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  12. Mutation of chromatin modifiers; an emerging hallmark of germinal center B-cell lymphomas

    PubMed Central

    Lunning, M A; Green, M R

    2015-01-01

    Subtypes of non-Hodgkin's lymphomas align with different stages of B-cell development. Germinal center B-cell (GCB)-like diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and Burkitt's lymphoma (BL) each share molecular similarities with normal GCB cells. Recent next-generation sequencing studies have gained insight into the genetic etiology of these malignancies and revealed a high frequency of mutations within genes encoding proteins that modifying chromatin. These include activating and inactivating mutations of genes that perform post-translational modification of histones and organize chromatin structure. Here, we discuss the function of histone acetyltransferases (CREBBP, EP300), histone methyltransferases (KDM2C/D, EZH2) and regulators of higher order chromatin structure (HIST1H1C/D/E, ARID1A and SMARCA4) that have been reported to be mutated in ?5% of DLBCL, FL or BL. Mutations of these genes are an emerging hallmark of lymphomas with GCB-cell origins, and likely represent the next generation of therapeutic targets for these malignancies. PMID:26473533

  13. Mutation of chromatin modifiers; an emerging hallmark of germinal center B-cell lymphomas.

    PubMed

    Lunning, M A; Green, M R

    2015-01-01

    Subtypes of non-Hodgkin's lymphomas align with different stages of B-cell development. Germinal center B-cell (GCB)-like diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and Burkitt's lymphoma (BL) each share molecular similarities with normal GCB cells. Recent next-generation sequencing studies have gained insight into the genetic etiology of these malignancies and revealed a high frequency of mutations within genes encoding proteins that modifying chromatin. These include activating and inactivating mutations of genes that perform post-translational modification of histones and organize chromatin structure. Here, we discuss the function of histone acetyltransferases (CREBBP, EP300), histone methyltransferases (KDM2C/D, EZH2) and regulators of higher order chromatin structure (HIST1H1C/D/E, ARID1A and SMARCA4) that have been reported to be mutated in ?5% of DLBCL, FL or BL. Mutations of these genes are an emerging hallmark of lymphomas with GCB-cell origins, and likely represent the next generation of therapeutic targets for these malignancies. PMID:26473533

  14. DNA-PKcs Is Involved in Ig Class Switch Recombination in Human B Cells.

    PubMed

    Björkman, Andrea; Du, Likun; Felgentreff, Kerstin; Rosner, Cornelia; Pankaj Kamdar, Radhika; Kokaraki, Georgia; Matsumoto, Yoshihisa; Davies, E Graham; van der Burg, Mirjam; Notarangelo, Luigi D; Hammarström, Lennart; Pan-Hammarström, Qiang

    2015-12-15

    Nonhomologous end-joining (NHEJ) is one of the major DNA double-strand break repair pathways in mammalian cells and is required for both V(D)J recombination and class switch recombination (CSR), two Ig gene-diversification processes occurring during B cell development. DNA-dependent protein kinase, catalytic subunit (DNA-PKcs) is a component of the classical NHEJ machinery and has a critical function during V(D)J recombination. However, its role in CSR has been controversial. In this study, we examined the pattern of recombination junctions from in vivo-switched B cells from two DNA-PKcs-deficient patients. One of them harbored mutations that did not affect DNA-PKcs kinase activity but caused impaired Artemis activation; the second patient had mutations resulting in diminished DNA-PKcs protein expression and kinase activity. These results were compared with those from DNA-PKcs-deficient mouse B cells. A shift toward the microhomology-based alternative end-joining at the recombination junctions was observed in both human and mouse B cells, suggesting that the classical NHEJ pathway is impaired during CSR when DNA-PKcs is defective. Furthermore, cells from the second patient showed additional or more severe alterations in CSR and/or NHEJ, which may suggest that DNA-PKcs and/or its kinase activity have additional, Artemis-independent functions during these processes. PMID:26546606

  15. IFI16 Expression Is Related to Selected Transcription Factors during B-Cell Differentiation

    PubMed Central

    Piccaluga, Pier Paolo; Agostinelli, Claudio; Fuligni, Fabio; Righi, Simona; Tripodo, Claudio; Re, Maria Carla; Clò, Alberto; Miserocchi, Anna; Morini, Silvia; Gariglio, Marisa; Ferri, Gian Gaetano; Rinaldi-Ceroni, Alberto; Piccin, Ottavio; De Andrea, Marco; Pileri, Stefano A.; Landolfo, Santo; Gibellini, Davide

    2015-01-01

    The interferon-inducible DNA sensor IFI16 is involved in the modulation of cellular survival, proliferation, and differentiation. In the hematopoietic system, IFI16 is consistently expressed in the CD34+ stem cells and in peripheral blood lymphocytes; however, little is known regarding its regulation during maturation of B- and T-cells. We explored the role of IFI16 in normal B-cell subsets by analysing its expression and relationship with the major transcription factors involved in germinal center (GC) development and plasma-cell (PC) maturation. IFI16 mRNA was differentially expressed in B-cell subsets with significant decrease in IFI16 mRNA in GC and PCs with respect to naïve and memory subsets. IFI16 mRNA expression is inversely correlated with a few master regulators of B-cell differentiation such as BCL6, XBP1, POU2AF1, and BLIMP1. In contrast, IFI16 expression positively correlated with STAT3, REL, SPIB, RELA, RELB, IRF4, STAT5B, and STAT5A. ARACNE algorithm indicated a direct regulation of IFI16 by BCL6, STAT5B, and RELB, whereas the relationship between IFI16 and the other factors is modulated by intermediate factors. In addition, analysis of the CD40 signaling pathway showed that IFI16 gene expression directly correlated with NF-?B activation, indicating that IFI16 could be considered an upstream modulator of NF-?B in human B-cells. PMID:26185770

  16. CR2 ligands modulate human B cell activation.

    PubMed

    Bohnsack, J F; Cooper, N R

    1988-10-15

    A considerable body of evidence from this and other laboratories indicates that complement receptor type 2 (CR2) modulates B cell activation and growth. In the present studies we have examined the effects of three different types of CR2 ligands, i.e., monomeric, aggregated, and latex-bound C3dg; mAb to different CR2 epitopes; and UV-inactivated, non-transforming EBV (EBVUV) for their actions on highly purified, high density resting tonsil B cells. Although none of these ligands induced B cells to enter the cell cycle or synergized with either anti-mu or low m.w. B cell growth factor in triggering B cell mitogenesis, aggregated C3dg, latex-bound C3dg, the OKB7 anti-CR2 mAb, and EBVUV-enhanced thymidine incorporation by phorbol ester-activated tonsil B cells. Such enhancement was not T cell or monocyte dependent. The major action of the CR2 ligands thus seems to be to enhance the transition of B cells activated by certain stimuli from the G1 to the S phase of the cell cycle. In contrast to the action of aggregated and latex-bound C3dg, monomeric C3dg was inhibitory for phorbol ester and aggregated C3dg-induced B cell activation. The HB-5 anti-CR2 mAb, which reacts with a different epitope on CR2 from that of OKB7, did not synergize with PMA in B cell activation. These data provide additional evidence for a role for the CR2 in the control of B cell growth and provide a useful model for studying the CR2-mediated signals that affect the growth of B cells. PMID:2459218

  17. Antiviral Protection and Germinal Center Formation, But Impaired B Cell Memory in the Absence of CD19

    PubMed Central

    Fehr, Thomas; Rickert, Robert C.; Odermatt, Bernhard; Roes, Jürgen; Rajewsky, Klaus; Hengartner, Hans; Zinkernagel, Rolf M.

    1998-01-01

    Coligation of CD19, a molecule expressed during all stages of B cell development except plasmacytes, lowers the threshold for B cell activation with anti-IgM by a factor of 100. The cytoplasmic tail of CD19 contains nine tyrosine residues as possible phosphorylation sites and is postulated to function as the signal transducing element for complement receptor (CR)2. Generation and analysis of CD19 gene–targeted mice revealed that T cell–dependent (TD) antibody responses to proteinaceous antigens were impaired, whereas those to T cell–independent (TI) type 2 antigens were normal or even augmented. These results are compatible with earlier complement depletion studies and the postulated function of CD19. To analyze the role of CD19 in antiviral antibody responses, we immunized CD19?/? mice with viral antigens of TI-1, TI-2, and TD type. The effect of CD19 on TI responses was more dependent on antigen dose and replicative capacity than on antigen type. CR blocking experiments confirmed the role of CD19 as B cell signal transducer for complement. In contrast to immunization with protein antigens, infection of CD19?/? mice with replicating virus led to generation of specific germinal centers, which persisted for >100 d, whereas maintenance of memory antibody titers as well as circulating memory B cells was fully dependent on CD19. Thus, our study confirms a costimulatory role of CD19 on B cells under limiting antigen conditions and indicates an important role for B cell memory. PMID:9653091

  18. Murine Gammaherpesvirus 68 Reactivation from B Cells Requires IRF4 but Not XBP-1

    PubMed Central

    Matar, Caline G.; Rangaswamy, Udaya Shankari; Wakeman, Brian S.; Iwakoshi, Neal

    2014-01-01

    ABSTRACT Gammaherpesviruses display tropism for B cells and, like all known herpesviruses, exhibit distinct lytic and latent life cycles. One well-established observation among members of the gammaherpesvirus family is the link between viral reactivation from latently infected B cells and plasma cell differentiation. Importantly, a number of studies have identified a potential role for a CREB/ATF family member, X-box binding protein 1 (XBP-1), in trans-activating the immediate early BZLF-1 or BRLF1/gene 50 promoters of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), respectively. XBP-1 is required for the unfolded protein response and has been identified as a critical transcription factor in plasma cells. Here, we demonstrate that XBP-1 is capable of trans-activating the murine gammaherpesvirus 68 (MHV68) RTA promoter in vitro, consistent with previous observations for EBV and KSHV. However, we show that in vivo there does not appear to be a requirement for XBP-1 expression in B cells for virus reactivation. The MHV68 M2 gene product under some experimental conditions plays an important role in virus reactivation from B cells. M2 has been shown to drive B cell differentiation to plasma cells, as well as interleukin-10 (IL-10) production, both of which are dependent on M2 induction of interferon regulatory factor 4 (IRF4) expression. IRF4 is required for plasma cell differentiation, and consistent with a role for plasma cells in MHV68 reactivation from B cells, we show that IRF4 expression in B cells is required for efficient reactivation of MHV68 from splenocytes. Thus, the latter analyses are consistent with previous studies linking plasma cell differentiation to MHV68 reactivation from B cells. The apparent independence of MHV68 reactivation from XBP-1 expression in plasma cells may reflect redundancy among CREB/ATF family members or the involvement of other plasma cell-specific transcription factors. Regardless, these findings underscore the importance of in vivo studies in assessing the relevance of observations made in tissue culture models. IMPORTANCE All known herpesviruses establish a chronic infection of their respective host, persisting for the life of the individual. A critical feature of these viruses is their ability to reactivate from a quiescent form of infection (latency) and generate progeny virus. In the case of gammaherpesviruses, which are associated with the development of lymphoproliferative disorders, including lymphomas, reactivation from latently infected B lymphocytes occurs upon terminal differentiation of these cells to plasma cells—the cell type that produces antibodies. A number of studies have linked a plasma cell transcription factor, XBP-1, to the induction of gammaherpesvirus reactivation, and we show here that indeed in tissue culture models this cellular transcription factor can trigger expression of the murine gammaherpesvirus gene involved in driving virus reactivation. However, surprisingly, when we examined the role of XBP-1 in the setting of infection of mice—using mice that lack a functional XBP-1 gene in B cells—we failed to observe a role for XBP-1 in virus reactivation. However, we show that another cellular factor essential for plasma cell differentiation, IRF4, is critical for virus reactivation. Thus, these studies point out the importance of studies in animal models to validate findings from studies carried out in cell lines passaged in vitro. PMID:25078688

  19. DNA breaks early in replication in B cell cancers

    Cancer.gov

    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.

  20. What are regulatory B cells? David Gray1

    E-print Network

    of B cells is mediated by the production of the cytokine IL-10, which inhibits both Th1 and Th2 producing significant amounts of inflammatory cytokines as well, these B cells suppress T-cell proliferation polarization, Ag presentation and pro-inflammatory cytokine production by myeloid cells. A suppressive role

  1. Uptake and Presentation of Antigen by B Cells 

    E-print Network

    Brooks, Katharine E

    B cells internalize antigen in a specific manner through the B cell receptor (BCR). The antigen is processed into peptides that are loaded on to MHC class II molecules and presented to CD4+ T cells. I have investigated factors that affect how...

  2. Subcutaneous Dissemination from an Orbital Diffuse Large B Cell Lymphoma.

    PubMed

    Bains, Sukhdeep; Vidhya, N; Kim, Usha; Shanti, R; Devanand, J

    2015-12-01

    Secondary cutaneous dissemination from an orbital diffuse large B cell lymphoma has not been described before. The authors report an unusual case of anaplastic variant of diffuse large B cell lymphoma which primarily presented in the orbit and during the course of disease had subcutaneous dissemination. PMID:26452055

  3. B Cells: The Old New Players in Reproductive Immunology

    PubMed Central

    Fettke, Franziska; Schumacher, Anne; Costa, Serban-Dan; Zenclussen, Ana Claudia

    2014-01-01

    Reproductive immunology research has long focused on T cell responses to paternal antigens and tolerance mechanisms supporting fetal well-being. The participation of B cells herein was not widely studied. Because of the fascinating immunological uniqueness of pregnancy, it is however to be expected that such pleiotropic cells play a considerable role. In fact, on the one hand B cells contribute toward pregnancy tolerance by secreting the immunomodulatory cytokine IL-10 but on the other hand can seriously harm pregnancy because of their capacity of producing autoantibodies. As for protective B cells, new evidences in mouse models arise suggesting that IL-10 producing B cells, the so-called B10 cells, help in maintaining tolerance toward semi-allogenic fetal antigens. They may be also important to fight danger signals at the fetal-maternal interface as, e.g., in the case of infections with the aim to restore the disrupted fetal tolerance. In human pregnancies, IL-10 producing B cells increase with pregnancy onset but not in the case of spontaneous abortions. In vitro, they are able to suppress TNF-? production by T cells from pregnant individuals. Their generation and functionality will be discussed throughout this review article. B cells can be deleterious to pregnancy as well. Aberrant B cell compartment is associated with obstetric pathologies. In particular, the capacity of B2 cells to produce specific autoantibodies or of B-1a B cells to secrete natural autoantibodies that can turn autoreactive will be discussed herein. PMID:25002862

  4. Species D Adenoviruses as Oncolytics Against B Cell Cancers

    PubMed Central

    Chen, Christopher Y.; Senac, Julien S.; Weaver, Eric A.; May, Shannon M.; Jelinek, Diane F.; Greipp, Philip; Witzig, Thomas; Barry, Michael A.

    2011-01-01

    Purpose Oncolytic viruses are self-amplifying anti-cancer agents that make use of the natural ability of viruses to kill cells. Adenovirus serotype 5 (Ad5) has been extensively tested against solid cancers, but less so against B cell cancers since these cells do not generally express the coxsackie and adenoviral receptor (CAR). To determine if other adenoviruses might have better potency, we “mined” the adenovirus virome of 55 serotypes for viruses that could kill B cell cancers. Experimental Design 15 adenoviruses selected to represent Ad species B, C, D, E, and F were tested in vitro against cell lines and primary patient B cell cancers for their ability to infect, replicate in, and kill these cells. Select viruses were also tested against B cell cancer xenografts in immunodeficient mice. Results Species D adenoviruses mediated most robust killing against a range of B cell cancer cell lines, against primary patient marginal zone lymphoma cells, and against primary patient CD138+ myeloma cells in vitro. When injected into xenografts in vivo, single treatment with select species D viruses Ad26 and Ad45 delayed lymphoma growth. Conclusions Relatively unstudied species D adenoviruses have a unique ability to infect and replicate in B cell cancers as compared to other adenovirus species. These data suggest these viruses have unique biology in B cells and support translation of novel species D adenoviruses as oncolytics against B cell cancers. PMID:21890454

  5. Suppressive functions of B cells in infectious diseases.

    PubMed

    Shen, Ping; Fillatreau, Simon

    2015-11-01

    B lymphocytes are often essential to successfully control invading pathogens and play a primary role in the protection afforded by successful vaccines through the production of specific antibodies. However, recent studies have highlighted the complex roles of B cells in infectious diseases, showing unexpectedly that some activated B cells limited host defense towards pathogens. This B-cell function involves production of regulatory cytokines including IL-10 and IL-35 and is reminiscent of the regulatory functions of B cells initially defined in autoimmune diseases. It is now known that various types of microbes including bacteria, helminths and viruses can induce IL-10-expressing B cells with inhibitory functions, indicating that this response is a general component of anti-microbial immunity. Interestingly, IL-10-producing B cells induced in the course of some microbial infections can inhibit concurrent immune responses directed towards unrelated antigens in a bystander manner and as a consequence ameliorate the course of autoimmune or allergic diseases. This could explain how some micro-organisms might provide protection from these pathologies, as formulated in the 'hygiene hypothesis'. In this review, we discuss the regulatory functions of B cells in bacterial, parasitic and viral infections, taking into account the phenotype of the B cells implicated, the signals controlling their induction and the cell types targeted by their suppressive activities. PMID:26066008

  6. Thymic B Cells and Central T Cell Tolerance

    PubMed Central

    Yamano, Tomoyoshi; Steinert, Madlen; Klein, Ludger

    2015-01-01

    Central T cell tolerance is believed to be mainly induced by thymic dendritic cells and medullary thymic epithelial cells. The thymus also harbors substantial numbers of B cells. These may arise though intrathymic B lymphopoiesis or immigration from the bloodstream. Importantly, and in contrast to resting “mainstream” B cells in the periphery, thymic B cells display elevated levels of MHC class II and constitutively express CD80. Arguably, their most unexpected feature is the expression of autoimmune regulator. These unique features of thymic B cells result from a licensing process that involves cross-talk with CD4 single-positive T cells and CD40 signaling. Together, these recent findings suggest that B cells play a more prominent role as thymic APCs than previously appreciated. PMID:26257742

  7. Molecular Mechanisms of B Cell Antigen Gathering and Endocytosis.

    PubMed

    Hoogeboom, Robbert; Tolar, Pavel

    2016-01-01

    Generation of high-affinity, protective antibodies requires B cell receptor (BCR) signaling, as well as antigen internalization and presentation to helper T cells. B cell antigen internalization is initiated by antigen capture, either from solution or from immune synapses formed on the surface of antigen-presenting cells, and proceeds via clathrin-dependent endocytosis and intracellular routing to late endosomes. Although the components of this pathway are still being discovered, it has become clear that antigen internalization is actively regulated by BCR signaling at multiple steps and, vice versa, that localization of the BCR along the endocytic pathway modulates signaling. Accordingly, defects in BCR internalization or trafficking contribute to enhanced B cell activation in models of autoimmune diseases and in B cell lymphomas. In this review, we discuss how BCR signaling complexes regulate each of the steps of this endocytic process and why defects along this pathway manifest as hyperactive B cell responses in vivo. PMID:26336965

  8. An intrinsic B cell defect is required for the production of autoantibodies in the lpr model of murine systemic autoimmunity

    SciTech Connect

    Sobel, E.S.; Katagiri, T.; Katagiri, K.; Morris, S.C.; Cohen, P.L.; Eisenberg, R.A. )

    1991-06-01

    Mice homozygous for the gene lpr develop marked lymphadenopathy and a spectrum of autoantibodies closely resembling that of human systemic lupus erythematosus. The unusual T cell phenotype of the expanded lymphocyte population and the T-dependence of several antibodies in this strain have suggested that primary T cell abnormalities underlie the autoimmune syndrome. Using double chimeras, we now show that expression of the lpr gene in B cells is absolutely necessary for autoantibody production. Combinations of anti-Thy 1.2 + C' treated bone marrow from congenic strains of C57BL/6 mice, differing only at the immunoglobulin heavy chain (Igh) and lpr loci, were transferred into lethally irradiated B6/lpr mice. Double chimerism was documented by allotype-specific surface IgD and IgM immunofluorescence assay of peripheral blood and by allotype-specific enzyme-linked immunosorbent assay for total IgM in serum. Despite the presence of both +/+ and lpr B cells, IgM and IgG2a anti-chromatin as well as IgM anti-IgG were entirely the products of lpr B cells. Total serum IgG2a and IgG1 were also dominated by the lpr phenotype but not to the same extent. A similar experiment using B6/lpr-Igha recipients confirmed these findings. Additional experiments in which B6/lpr recipients were infused with ratios of donor bone marrow favoring B6.C20 +/+ over B6/lpr showed that even though +/+ B cells were overrepresented, autoantibodies were only of the lpr allotype. In addition, in the presence of lpr B cells, normal B cells showed little response to an exogenous, T cell-dependent antigen. The data thus indicate that lpr B cells manifest an intrinsic abnormality which is essential for autoantibody production in the lpr model.

  9. An intrinsic B cell defect is required for the production of autoantibodies in the lpr model of murine systemic autoimmunity

    PubMed Central

    1991-01-01

    Mice homozygous for the gene lpr develop marked lymphadenopathy and a spectrum of autoantibodies closely resembling that of human systemic lupus erythematosus. The unusual T cell phenotype of the expanded lymphocyte population and the T-dependence of several antibodies in this strain have suggested that primary T cell abnormalities underlie the autoimmune syndrome. Using double chimeras, we now show that expression of the lpr gene in B cells is absolutely necessary for autoantibody production. Combinations of anti-Thy 1.2 + C' treated bone marrow from congenic strains of C57BL/6 mice, differing only at the immunoglobulin heavy chain (Igh) and lpr loci, were transferred into lethally irradiated B6/lpr mice. Double chimerism was documented by allotype-specific surface IgD and IgM immunofluorescence assay of peripheral blood and by allotype-specific enzyme-linked immunosorbent assay for total IgM in serum. Despite the presence of both +/+ and lpr B cells, IgM and IgG2a anti-chromatin as well as IgM anti-IgG were entirely the products of lpr B cells. Total serum IgG2a and IgG1 were also dominated by the lpr phenotype but not to the same extent. A similar experiment using B6/lpr-Igha recipients confirmed these findings. Additional experiments in which B6/lpr recipients were infused with ratios of donor bone marrow favoring B6.C20 +/+ over B6/lpr showed that even though +/+ B cells were overrepresented, autoantibodies were only of the lpr allotype. In addition, in the presence of lpr B cells, normal B cells showed little response to an exogenous, T cell-dependent antigen. The data thus indicate that lpr B cells manifest an intrinsic abnormality which is essential for autoantibody production in the lpr model. PMID:2033370

  10. B cell receptor accessory molecule CD79?: Characterisation and expression analysis in a cartilaginous fish, the spiny dogfish (Squalus acanthias)

    PubMed Central

    Li, Ronggai; Wang, Tiehui; Bird, Steve; Zou, Jun; Dooley, Helen; Secombes, Christopher J.

    2013-01-01

    CD79? (also known as Ig?) is a component of the B cell antigen receptor complex and plays an important role in B cell signalling. The CD79? protein is present on the surface of B cells throughout their life cycle, and is absent on all other healthy cells, making it a highly reliable marker for B cells in mammals. In this study the spiny dogfish (Squalus acanthias) CD79? (SaCD79?) is described and its expression studied under constitutive and stimulated conditions. The spiny dogfish CD79? cDNA contains an open reading frame of 618 bp, encoding a protein of 205 amino acids. Comparison of the SaCD79? gene with that of other species shows that the gross structure (number of exons, exon/intron boundaries, etc.) is highly conserved across phylogeny. Additionally, analysis of the 5? flanking region shows SaCD79? lacks a TATA box and possesses binding sites for multiple transcription factors implicated in its B cell-specific gene transcription in other species. Spiny dogfish CD79? is most highly expressed in immune tissues, such as spleen, epigonal and Leydig organ, and its transcript level significantly correlates with those of spiny dogfish immunoglobulin heavy chains. Additionally, CD79? transcription is up-regulated, to a small but significant degree, in peripheral blood cells following stimulation with pokeweed mitogen. These results strongly indicate that, as in mammals, spiny dogfish CD79? is expressed by shark B cells where it associates with surface-bound immunoglobulin to form a fully functional BCR, and thus may serve as a pan-B cell marker in future shark immunological studies. PMID:23454429

  11. Identification of chromosomal translocation hotspots via scan statistics

    PubMed Central

    Silva, Israel T.; Rosales, Rafael A.; Holanda, Adriano J.; Nussenzweig, Michel C.; Jankovic, Mila

    2014-01-01

    Motivation: The detection of genomic regions unusually rich in a given pattern is an important undertaking in the analysis of next-generation sequencing data. Recent studies of chromosomal translocations in activated B lymphocytes have identified regions that are frequently translocated to c-myc oncogene. A quantitative method for the identification of translocation hotspots was crucial to this study. Here we improve this analysis by using a simple probabilistic model and the framework provided by scan statistics to define the number and location of translocation breakpoint hotspots. A key feature of our method is that it provides a global chromosome-wide nominal control level to clustering, as opposed to previous methods based on local criteria. While being motivated by a specific application, the detection of unusual clusters is a widespread problem in bioinformatics. We expect our method to be useful in the analysis of data from other experimental approaches such as of ChIP-seq and 4C-seq. Results: The analysis of translocations from B lymphocytes with the method described here reveals the presence of longer hotspots when compared with those defined previously. Further, we show that the hotspot size changes substantially in the absence of DNA repair protein 53BP1. When 53BP1 deficiency is combined with overexpression of activation-induced cytidine deaminase, the hotspot length increases even further. These changes are not detected by previous methods that use local significance criteria for clustering. Our method is also able to identify several exclusive translocation hotspots located in genes of known tumor supressors. Availability and implementation: The detection of translocation hotspots is done with hot_scan, a program implemented in R and Perl. Source code and documentation are freely available for download at https://github.com/itojal/hot_scan. Contact: isilva@rockefeller.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24860160

  12. The Role of B Cells in the Development of CD4 Effector T Cells during a Polarized Th2 Immune Response1

    PubMed Central

    Liu, Qian; Liu, Zhugong; Rozo, Cristina T.; Hamed, Hossein A.; Alem, Farhang; Urban, Joseph F.; Gause, William C.

    2008-01-01

    Previous studies have suggested that B cells promote Th2 cell development by inhibiting Th1 cell differentiation. To examine whether B cells are directly required for the development of IL-4-producing T cells in the lymph node during a highly polarized Th2 response, B cell-deficient and wild-type mice were inoculated with the nematode parasite, Nippostrongylus brasiliensis. On day 7, in the absence of increased IFN-?, IL-4 protein and gene expression from CD4 T cells in the draining lymph nodes were markedly reduced in B cell-deficient mice and could not be restored by multiple immunizations. Using a DO11.10 T cell adoptive transfer system, OVA-specific T cell IL-4 production and cell cycle progression, but not cell surface expression of early activation markers, were impaired in B cell-deficient recipient mice following immunization with N. brasiliensis plus OVA. Laser capture microdissection and immunofluorescent staining showed that pronounced IL-4 mRNA and protein secretion by donor DO11.10 T cells first occurred in the T cell:B cell zone of the lymph node shortly after inoculation of IL-4?/? recipients, suggesting that this microenvironment is critical for initial Th2 cell development. Reconstitution of B cell-deficient mice with wild-type naive B cells, or IL-4?/? B cells, substantially restored Ag-specific T cell IL-4 production. However, reconstitution with B7-1/B7-2-deficient B cells failed to rescue the IL-4-producing DO11.10 T cells. These results suggest that B cells, expressing B7 costimulatory molecules, are required in the absence of an underlying IFN-?-mediated response for the development of a polarized primary Ag-specific Th2 response in vivo. PMID:17785819

  13. Transient expression of Bcl6 is sufficient for oncogenic function and induction of mature B-cell lymphoma

    PubMed Central

    Green, Michael R; Vicente-Dueñas, Carolina; Romero-Camarero, Isabel; Liu, Chih Long; Dai, Bo; González-Herrero, Inés; García-Ramírez, Idoia; Alonso-Escudero, Esther; Iqbal, Javeed; Chan, Wing C; Campos-Sanchez, Elena; Orfao, Alberto; Pintado, Belén; Flores, Teresa; Blanco, Oscar; Jiménez, Rafael; Martínez-Climent, Jose Angel; Criado, Francisco Javier García; Cenador, María Begoña García; Zhao, Shuchun; Natkunam, Yasodha; Lossos, Izidore S; Majeti, Ravindra; Melnick, Ari; Cobaleda, César; Alizadeh, Ash A.; Sánchez-García, Isidro

    2015-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma and can be separated into two subtypes based upon molecular features with similarities to germinal center B-cells (GCB-like) or activated B-cells (ABC-like). Here we identify gain of 3q27.2 as being significantly associated with adverse outcome in DLBCL and linked with the ABC-like subtype. This lesion includes the BCL6 oncogene, but does not alter BCL6 transcript levels or target-gene repression. Separately, we identify expression of BCL6 in a subset of human hematopoietic stem/progenitor cells (HSPCs). We therefore hypothesize that BCL6 may act by hit-and-run oncogenesis. We model this by transiently expressing Bcl6 within murine HSPCs, and find it causes mature B-cell lymphomas that lack Bcl6 expression and target-gene repression, are transcriptionally similar to post-GCB cells, and show epigenetic changes that are conserved from HSPCs to mature B-cells. Together these results suggest that Bcl6 may function in a hit-and-run role in lymphomagenesis. PMID:24887457

  14. Transient expression of Bcl6 is sufficient for oncogenic function and induction of mature B-cell lymphoma.

    PubMed

    Green, Michael R; Vicente-Dueñas, Carolina; Romero-Camarero, Isabel; Long Liu, Chih; Dai, Bo; González-Herrero, Inés; García-Ramírez, Idoia; Alonso-Escudero, Esther; Iqbal, Javeed; Chan, Wing C; Campos-Sanchez, Elena; Orfao, Alberto; Pintado, Belén; Flores, Teresa; Blanco, Oscar; Jiménez, Rafael; Martínez-Climent, Jose Angel; Criado, Francisco Javier García; Cenador, María Begoña García; Zhao, Shuchun; Natkunam, Yasodha; Lossos, Izidore S; Majeti, Ravindra; Melnick, Ari; Cobaleda, César; Alizadeh, Ash A; Sánchez-García, Isidro

    2014-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma and can be separated into two subtypes based upon molecular features with similarities to germinal centre B-cells (GCB-like) or activated B-cells (ABC-like). Here we identify gain of 3q27.2 as being significantly associated with adverse outcome in DLBCL and linked with the ABC-like subtype. This lesion includes the BCL6 oncogene, but does not alter BCL6 transcript levels or target-gene repression. Separately, we identify expression of BCL6 in a subset of human haematopoietic stem/progenitor cells (HSPCs). We therefore hypothesize that BCL6 may act by 'hit-and-run' oncogenesis. We model this hit-and-run mechanism by transiently expressing Bcl6 within murine HSPCs, and find that it causes mature B-cell lymphomas that lack Bcl6 expression and target-gene repression, are transcriptionally similar to post-GCB cells, and show epigenetic changes that are conserved from HSPCs to mature B-cells. Together, these results suggest that BCL6 may function in a 'hit-and-run' role in lymphomagenesis. PMID:24887457

  15. Epigenetic Heterogeneity of B-Cell Lymphoma: Chromatin Modifiers

    PubMed Central

    Hopp, Lydia; Nersisyan, Lilit; Löffler-Wirth, Henry; Arakelyan, Arsen; Binder, Hans

    2015-01-01

    We systematically studied the expression of more than fifty histone and DNA (de)methylating enzymes in lymphoma and healthy controls. As a main result, we found that the expression levels of nearly all enzymes become markedly disturbed in lymphoma, suggesting deregulation of large parts of the epigenetic machinery. We discuss the effect of DNA promoter methylation and of transcriptional activity in the context of mutated epigenetic modifiers such as EZH2 and MLL2. As another mechanism, we studied the coupling between the energy metabolism and epigenetics via metabolites that act as cofactors of JmjC-type demethylases. Our study results suggest that Burkitt’s lymphoma and diffuse large B-cell Lymphoma differ by an imbalance of repressive and poised promoters, which is governed predominantly by the activity of methyltransferases and the underrepresentation of demethylases in this regulation. The data further suggest that coupling of epigenetics with the energy metabolism can also be an important factor in lymphomagenesis in the absence of direct mutations of genes in metabolic pathways. Understanding of epigenetic deregulation in lymphoma and possibly in cancers in general must go beyond simple schemes using only a few modes of regulation. PMID:26506391

  16. ATM deficiency promotes development of murine B-cell lymphomas that resemble diffuse large B-cell lymphoma in humans.

    PubMed

    Hathcock, Karen S; Padilla-Nash, Hesed M; Camps, Jordi; Shin, Dong-Mi; Triner, Daniel; Shaffer, Arthur L; Maul, Robert W; Steinberg, Seth M; Gearhart, Patricia J; Staudt, Louis M; Morse, Herbert C; Ried, Thomas; Hodes, Richard J

    2015-11-12

    The serine-threonine kinase ataxia-telangiectasia mutated (ATM) plays a central role in maintaining genomic integrity. In mice, ATM deficiency is exclusively associated with T-cell lymphoma development, whereas B-cell tumors predominate in human ataxia-telangiectasia patients. We demonstrate in this study that when T cells are removed as targets for lymphomagenesis and as mediators of immune surveillance, ATM-deficient mice exclusively develop early-onset immunoglobulin M(+) B-cell lymphomas that do not transplant to immunocompetent mice and that histologically and genetically resemble the activated B cell-like (ABC) subset of human diffuse large B-cell lymphoma (DLBCL). These B-cell lymphomas show considerable chromosomal instability and a recurrent genomic amplification of a 4.48-Mb region on chromosome 18 that contains Malt1 and is orthologous to a region similarly amplified in human ABC DLBCL. Of importance, amplification of Malt1 in these lymphomas correlates with their dependence on nuclear factor (NF)-?B, MALT1, and B-cell receptor (BCR) signaling for survival, paralleling human ABC DLBCL. Further, like some human ABC DLBCLs, these mouse B-cell lymphomas also exhibit constitutive BCR-dependent NF-?B activation. This study reveals that ATM protects against development of B-cell lymphomas that model human ABC DLBCL and identifies a potential role for T cells in preventing the emergence of these tumors. PMID:26400962

  17. ATM deficiency promotes development of murine B-cell lymphomas that resemble diffuse large B-cell lymphoma in humans

    PubMed Central

    Hathcock, Karen S.; Padilla-Nash, Hesed M.; Camps, Jordi; Shin, Dong-Mi; Triner, Daniel; Shaffer, Arthur L.; Maul, Robert W.; Steinberg, Seth M.; Gearhart, Patricia J.; Staudt, Louis M.; Morse, Herbert C.; Ried, Thomas

    2015-01-01

    The serine-threonine kinase ataxia-telangiectasia mutated (ATM) plays a central role in maintaining genomic integrity. In mice, ATM deficiency is exclusively associated with T-cell lymphoma development, whereas B-cell tumors predominate in human ataxia-telangiectasia patients. We demonstrate in this study that when T cells are removed as targets for lymphomagenesis and as mediators of immune surveillance, ATM-deficient mice exclusively develop early-onset immunoglobulin M+ B-cell lymphomas that do not transplant to immunocompetent mice and that histologically and genetically resemble the activated B cell–like (ABC) subset of human diffuse large B-cell lymphoma (DLBCL). These B-cell lymphomas show considerable chromosomal instability and a recurrent genomic amplification of a 4.48-Mb region on chromosome 18 that contains Malt1 and is orthologous to a region similarly amplified in human ABC DLBCL. Of importance, amplification of Malt1 in these lymphomas correlates with their dependence on nuclear factor (NF)-?B, MALT1, and B-cell receptor (BCR) signaling for survival, paralleling human ABC DLBCL. Further, like some human ABC DLBCLs, these mouse B-cell lymphomas also exhibit constitutive BCR-dependent NF-?B activation. This study reveals that ATM protects against development of B-cell lymphomas that model human ABC DLBCL and identifies a potential role for T cells in preventing the emergence of these tumors. PMID:26400962

  18. Localization of the 17q breakpoint of a constitutional 1;17 translocation in a patient with neuroblastoma within a 25-kb segment located between the ACCN1 and TLK2 genes and near the distal breakpoints of two microdeletions in neurofibromatosis type 1 patients.

    PubMed

    Van Roy, Nadine; Vandesompele, Jo; Berx, Geert; Staes, Katrien; Van Gele, Mireille; De Smet, Els; De Paepe, Anne; Laureys, Geneviève; van der Drift, Pauline; Versteeg, Rogier; Van Roy, Frans; Speleman, Frank

    2002-10-01

    We have constructed a 1.4-Mb P1 artificial chromosome/bacterial artificial chromosome (PAC/BAC) contig spanning the 17q breakpoint of a constitutional translocation t(1;17)(p36.2;q11.2) in a patient with neuroblastoma. Three 17q breakpoint-overlapping cosmids were identified and sequenced. No coding sequences were found in the immediate proximity of the 17q breakpoint. The PAC/BAC contig covers the region between the proximally located ACCN1 gene and the distally located TLK2 gene and SCYA chemokine gene cluster. The observation that the 17q breakpoint region could not be detected in any of the screened yeast artificial chromosome libraries and the localization of the 17q breakpoint in the vicinity of the distal breakpoints of two microdeletions in patients with neurofibromatosis type 1 suggest that this chromosomal region is genetically unstable and prone to rearrangements. PMID:12203774

  19. Overexpression of RelA Causes G1 Arrest and Apoptosis in a Pro-B Cell Line*

    E-print Network

    Schlissel, Mark S.

    of the cell death program. To examine the function of individual Rel family proteins in B cell development§ From the Graduate Program in Immunology, Departments of Medicine, Molecular Biology & Genetics- tokine gene expression, regulated cell cycle activation, and both the protection from and induction

  20. MicroRNA Profiling of Primary Cutaneous Large B-Cell Lymphomas

    PubMed Central

    Koens, Lianne; Qin, Yongjun; Leung, Wai Y.; Corver, Willem E.; Jansen, Patty M.; Willemze, Rein; Vermeer, Maarten H.; Tensen, Cornelis P.

    2013-01-01

    Aberrant expression of microRNAs is widely accepted to be pathogenetically involved in nodal diffuse large B-cell lymphomas (DLBCLs). However, the microRNAs profiles of primary cutaneous large B-cell lymphomas (PCLBCLs) are not yet described. Its two main subtypes, i.e., primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) and primary cutaneous follicle center lymphoma (PCFCL) are characterized by an activated B-cell (ABC)-genotype and a germinal center B-cell (GCB)-genotype, respectively. We performed high-throughput sequencing analysis on frozen tumor biopsies from 19 cases of PCFCL and PCLBCL-LT to establish microRNA profiles. Cluster analysis of the complete microRNome could not distinguish between the two subtypes, but 16 single microRNAs were found to be differentially expressed. Single microRNA RT-qPCR was conducted on formalin-fixed paraffin-embedded tumor biopsies of 20 additional cases, confirming higher expression of miR-9-5p, miR-31-5p, miR-129-2-3p and miR-214-3p in PCFCL as compared to PCLBCL-LT. MicroRNAs previously described to be higher expressed in ABC-type as compared to GCB-type nodal DLBCL were not differentially expressed between PCFCL and PCLBCL-LT. In conclusion, PCFCL and PCLBCL-LT differ in their microRNA profiles. In contrast to their gene expression profile, they only show slight resemblance with the microRNA profiles found in GCB- and ABC-type nodal DLBCL. PMID:24358187

  1. B-cell intrinsic TLR7 signals promote depletion of the marginal zone in a murine model of Wiskott-Aldrich syndrome.

    PubMed

    Kolhatkar, Nikita S; Scharping, Nicole E; Sullivan, Jenna M; Jacobs, Holly M; Schwartz, Marc A; Khim, Socheath; Notarangelo, Luigi D; Thrasher, Adrian J; Rawlings, David J; Jackson, Shaun W

    2015-10-01

    Patients with Wiskott-Aldrich syndrome (WAS) exhibit prominent defects in splenic marginal zone (MZ), resulting in abnormal T-cell-independent antibody responses and increased bacterial infections. B-cell-intrinsic deletion of the affected gene WAS protein (WASp) markedly reduces splenic MZ B cells, without impacting the rate of MZ B-cell development, suggesting that abnormal B-cell retention within the MZ accounts for MZ defects in WAS. Since WASp regulates integrin-dependent actin cytoskeletal rearrangement, we previously hypothesized that defective B-cell integrin function promotes MZ depletion. In contrast, we now report that B-cell-intrinsic deletion of the TLR signaling adaptor MyD88 is sufficient to restore the MZ in WAS. We further identify TLR7, an endosomal single-stranded RNA (ssRNA) receptor, as the MyD88-dependent receptor responsible for WAS MZ depletion. These findings implicate spontaneous activation of MZ B cells by ssRNA-containing self-ligands (likely derived from circulating apoptotic material) as the mechanism underlying MZ depletion in WAS. Together, these data suggest a previously unappreciated role for B-cell intrinsic TLR signals in MZ homeostasis, of relevance to both pathogen responses and to the development of systemic autoimmunity. PMID:26256668

  2. Mechanism of helicase translocation along nucleic acid

    E-print Network

    Zhang, Yunxin

    2012-01-01

    In cells, helicase translocation along nucleic acid is essential for many biological processes. However, so far, the mechanism of this translocation is not fully understood. Recent studies show that helicase might translocate through two processes, active process and passive process, with different translocation rate. In this study, a model including such two processes is presented. In which, each of these two processes consists of two sub-processes, chemical sub-process in which needed translocation factors are attached, and mechanochemical sub-process in which helicase makes a forward translocation step. Helicase can switch stochastically between these two processes with external force dependent rates. By this model, ribosome translocation along message RNA is detailed discussed. We found that, with the increase of external force, the mean translocation rate of ribosome increases from one lower limit to one upper limit, and both of these two limits increase with concentrations of the translocation factors. ...

  3. Phenotypic Approaches to Identify Inhibitors of B Cell Activation.

    PubMed

    Rex, Elizabeth B; Kim, Suzie; Wiener, Jake; Rao, Navin L; Milla, Marcos E; DiSepio, Daniel

    2015-08-01

    An EPIC label-free phenotypic platform was developed to explore B cell receptor (BCR) and CD40R-mediated B cell activation. The phenotypic assay measured the association of RL non-Hodgkin's lymphoma B cells expressing lymphocyte function-associated antigen 1 (LFA-1) to intercellular adhesion molecule 1 (ICAM-1)-coated EPIC plates. Anti-IgM (immunoglobulin M) mediated BCR activation elicited a response that was blocked by LFA-1/ICAM-1 specific inhibitors and a panel of Bruton's tyrosine kinase (BTK) inhibitors. LFA-1/ICAM-1 association was further increased on coapplication of anti-IgM and mega CD40L when compared to individual application of either. Anti-IgM, mega CD40L, or the combination of both displayed distinct kinetic profiles that were inhibited by treatment with a BTK inhibitor. We also established a FLIPR-based assay to measure B cell activation in Ramos Burkitt's lymphoma B cells and an RL cell line. Anti-IgM-mediated BCR activation elicited a robust calcium response that was inhibited by a panel of BTK inhibitors. Conversely, CD40R activation did not elicit a calcium response in the FLIPR assay. Compared to the FLIPR, the EPIC assay has the propensity to identify inhibitors of both BCR and CD40R-mediated B cell activation and may provide more pharmacological depth or novel mechanisms of action for inhibition of B cell activation. PMID:25948491

  4. B Cells in Chronic Graft versus Host Disease

    PubMed Central

    Sarantopoulos, Stefanie; Blazar, Bruce R.; Cutler, Corey; Ritz, Jerome

    2015-01-01

    Chronic graft versus host disease (cGVHD) continues to be a common complication of allogeneic hematopoietic stem cell transplantation (HSCT). Unlike acute GVHD, which is mediated almost entirely by donor T cells, the immune pathology of cGVHD is more complex and donor B cells have also been found to play an important role. Recent studies from several laboratories have enhanced our understanding of how donor B cells contribute to this clinical syndrome and this has led to new therapeutic opportunities. Here, Dr. Sarantopoulos reviews some of the important mechanisms responsible for persistent B cell activation and loss of B cell tolerance in patients with cGVHD. Dr. Blazar describes recent studies in preclinical models that have identified novel B cell directed agents that may be effective for prevention or treatment of cGVHD. Some B cell directed therapies have already been tested in patients with cGVHD and Dr. Cutler reviews the results of these studies documenting the potential efficacy of this approach. Supported by studies mechanistic studies in patients and preclinical models, new B cell directed therapies for cGVHD will now be evaluated in clinical trials. PMID:25452031

  5. Phenotypic Approaches to Identify Inhibitors of B Cell Activation

    PubMed Central

    Kim, Suzie; Wiener, Jake; Rao, Navin L.; Milla, Marcos E.; DiSepio, Daniel

    2015-01-01

    An EPIC label-free phenotypic platform was developed to explore B cell receptor (BCR) and CD40R-mediated B cell activation. The phenotypic assay measured the association of RL non-Hodgkin’s lymphoma B cells expressing lymphocyte function-associated antigen 1 (LFA-1) to intercellular adhesion molecule 1 (ICAM-1)-coated EPIC plates. Anti-IgM (immunoglobulin M) mediated BCR activation elicited a response that was blocked by LFA-1/ICAM-1 specific inhibitors and a panel of Bruton’s tyrosine kinase (BTK) inhibitors. LFA-1/ICAM-1 association was further increased on coapplication of anti-IgM and mega CD40L when compared to individual application of either. Anti-IgM, mega CD40L, or the combination of both displayed distinct kinetic profiles that were inhibited by treatment with a BTK inhibitor. We also established a FLIPR-based assay to measure B cell activation in Ramos Burkitt’s lymphoma B cells and an RL cell line. Anti-IgM-mediated BCR activation elicited a robust calcium response that was inhibited by a panel of BTK inhibitors. Conversely, CD40R activation did not elicit a calcium response in the FLIPR assay. Compared to the FLIPR, the EPIC assay has the propensity to identify inhibitors of both BCR and CD40R-mediated B cell activation and may provide more pharmacological depth or novel mechanisms of action for inhibition of B cell activation. PMID:25948491

  6. miR-15b/16-2 deletion promotes B-cell malignancies.

    PubMed

    Lovat, Francesca; Fassan, Matteo; Gasparini, Pierluigi; Rizzotto, Lara; Cascione, Luciano; Pizzi, Marco; Vicentini, Caterina; Balatti, Veronica; Palmieri, Dario; Costinean, Stefan; Croce, Carlo M

    2015-09-15

    The central role of the microRNA (miR) 15a/16-1 cluster in B-cell oncogenesis has been extensively demonstrated, with over two-thirds of B-cell chronic lymphocytic leukemia characterized by the deletion of the miR-15a/16-1 locus at 13q14. Despite the well-established understanding of the molecular mechanisms occurring during miR-15a/16-1 dysregulation, the oncogenic role of other miR-15/16 family members, such as the miR-15b/16-2 cluster (3q25), is still far from being elucidated. Whereas miR-15a is highly similar to miR-15b, miR-16-1 is identical to miR-16-2; thus, it could be speculated that both clusters control a similar set of target genes and may have overlapping functions. However, the biological role of miR-15b/16-2 is still controversial. We generated miR-15b/16-2 knockout mice to better understand the cluster's role in vivo. These mice developed B-cell malignancy by age 15-18 mo with a penetrance of 60%. At this stage, mice showed significantly enlarged spleens with abnormal B cell-derived white pulp enlargement. Flow cytometric analysis demonstrated an expanded CD19+ CD5+ population in the spleen of 40% knockout mice, a characteristic of the chronic lymphocytic leukemia-associated phenotype found in humans. Of note, miR-15b/16-2 modulates the CCND2 (Cyclin D2), CCND1 (Cyclin D1), and IGF1R (insulin-like growth factor 1 receptor) genes involved in proliferation and antiapoptotic pathways in mouse B cells. These results are the first, to our knowledge, to suggest an important role of miR-15b/16-2 loss in the pathogenesis of B-cell chronic lymphocytic leukemia. PMID:26324892

  7. The mechanics of ribosomal translocation.

    PubMed

    Achenbach, John; Nierhaus, Knud H

    2015-07-01

    The ribosome translates the sequence of codons of an mRNA into the corresponding sequence of amino acids as it moves along the mRNA with a codon-step width of about 10 Å. The movement of the million-dalton complex ribosome is triggered by the universal elongation factor G (EF2 in archaea and eukaryotes) and is termed translocation. Unraveling the molecular details of translocation is one of the most challenging tasks of current ribosome research. In the last two years, enormous progress has been obtained by highly-resolved X-ray and cryo-electron microscopic structures as well as by sophisticated biochemical approaches concerning the trigger and control of the movement of the tRNA2·mRNA complex inside the ribosome during translocation. This review inspects and surveys these achievements. PMID:25514765

  8. High Inter-Individual Diversity of Point Mutations, Insertions, and Deletions in Human Influenza Virus Nucleoprotein-Specific Memory B Cells

    PubMed Central

    Bussmann, Bianca M.; Horn, Susanne; Sieg, Michael; Jassoy, Christian

    2015-01-01

    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. PMID:26086076

  9. B cell regulation of anti-tumor immune response.

    PubMed

    Zhang, Yu; Morgan, Richard; Podack, Eckhard R; Rosenblatt, Joseph

    2013-12-01

    Our laboratory has been investigating the role of B cells on tumor immunity. We have studied the immune response in mice that are genetically lacking in B cells (BCDM) using a variety of syngeneic mouse tumors and compared immune responses in BCDM with those seen in wild type (WT) immunocompetent mice (ICM). A variety of murine tumors are rejected or inhibited in their growth in BCDM, compared with ICM, including the EL4 thymoma, and the MC38 colon carcinoma in C57BL/6 mice, as well as the EMT-6 breast carcinoma in BALB/c mice. In all three murine models, tumors show reduced growth in BCDM which is accompanied by increased T cell and NK cell infiltration, and a more vigorous Th1 cytokine response, and increased cytolytic T cell response in the absence of B cells. Reconstitution of the mice with B cells results in augmented tumor growth due to a diminished anti-tumor immune response and in reduction in CD8+ T cell and NK cell infiltration. Studies involving BCR transgenic mice indicated that B cells inhibit anti-tumor T cell responses through antigen non-specific mechanisms. More recent studies using the EMT-6 model demonstrated that both the number and function of Treg cells in ICM was increased relative to that seen in BCDM. Increased expansion of Treg cells was evident following EMT-6 implantation in ICM relative to that seen in non-tumor-bearing mice or BCDM. The percentage and number of Tregs in spleen, tumor draining lymph nodes, and the tumor bed are increased in ICM compared with BCDM. Treg functional capacity as measured by suppression assays appears to be reduced in BCDM compared with ICM. In contrast to other described types of B regulatory activity, adoptive transfer of B cells can rescue tumor growth independently of the ability of B cells to secrete IL-10, and also independently of MHC-II expression. In experiments using the MC38 adenocarcinoma model, BCDM reconstituted with WT B cells support tumor growth while tumor growth continues to be inhibited in BCDM reconstituted with OX40L(-/-) B cells. This suggests that interaction between OX40 on T cells and OX40-ligand on B cells may be important in modulating anti-tumor immune response. Ongoing experiments in the laboratory indicate that B cells migrate to the site of tumor and acquire expression of immunosuppressive ligands and/or cytokines that contribute to the inhibition of anti-tumor immune response. Significant infiltration of human tumors by Treg cells as well as B cells suggests that observations made in murine systems may be applicable to human tumors as well. PMID:24293009

  10. Primary Diffuse Large B-cell Lymphoma involving the Mandible.

    PubMed

    Alshahrani, Faleh Ali A; Aljabab, Abdulsalam S; Motabi, Ibraheem Hm; Alrashed, Abdullah; Anil, Sukumaran

    2015-01-01

    Lymphomas of the oral cavity are rare and typically present as intraosseous lesions that are most commonly diffuse large B-cell type. Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma histologically characterized by diffuse proliferation of large neoplastic B-lymphoid cells with a nuclear size equal to or exceeding normal histiocytic nuclei. A case of DLBCL of the mandible in an 18 years old male patient is presented. This report discusses this rare malignancy, including clinical presentation, histopathologic features, immunologic profile, treatment and prognosis. Though lymphoma of mandible is rare, it must be considered in differential diagnosis of swellings arising in the region. PMID:26581467

  11. B cell receptor signaling: picky about PI3Ks.

    PubMed

    Limon, Jose J; Fruman, David A

    2010-01-01

    The B cell receptor (BCR) and the pre-BCR control cell fate at many stages of B cell development, survival, and antigen response. Most of these processes require the activation of phosphatidylinositol 3-kinase (PI3K). Previous work has pointed to p110delta as the key catalytic isoform of PI3K for many B cell responses. A study of mice with different combinations of PI3K mutations confirms the central role of p110delta in agonist-mediated signaling, while identifying an unexpected function for the p110alpha isoform in tonic signaling by the pre-BCR and mature BCR. PMID:20699473

  12. Aberrant expression of homeobox gene SIX1 in Hodgkin lymphoma.

    PubMed

    Nagel, Stefan; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G; MacLeod, Roderick A F

    2015-11-24

    In Hodgkin lymphoma (HL) we recently identified deregulated expression of homeobox genes MSX1 and OTX2 which are physiologically involved in development of the embryonal neural plate border region. Here, we examined in HL homeobox gene SIX1 an additional regulator of this embryonal region mediating differentiation of placodal precursors. SIX1 was aberrantly activated in 12 % of HL patient samples in silico, indicating a pathological role in a subset of this B-cell malignancy. In addition, SIX1 expression was detected in HL cell lines which were used as models to reveal upstream factors and target genes of this basic developmental regulator. We detected increased copy numbers of the SIX1 locus at chromosome 14q23 correlating with enhanced expression while chromosomal translocations were absent. Moreover, comparative expression profiling data and pertinent gene modulation experiments indicated that the WNT-signalling pathway and transcription factor MEF2C regulate SIX1 expression. Genes encoding the transcription factors GATA2, GATA3, MSX1 and SPIB - all basic lymphoid regulators - were identified as targets of SIX1 in HL. In addition, cofactors EYA1 and TLE4, respectively, contrastingly mediated activation and suppression of SIX1 target gene expression. Thus, the protein domain interfaces may represent therapeutic targets in SIX1-positive HL subsets. Collectively, our data reveal a gene regulatory network with SIX1 centrally deregulating lymphoid differentiation and support concordance of lymphopoiesis/lymphomagenesis and developmental processes in the neural plate border region. PMID:26473286

  13. Sequential induction of NF-kappa B/Rel family proteins during B-cell terminal differentiation.

    PubMed Central

    Liou, H C; Sha, W C; Scott, M L; Baltimore, D

    1994-01-01

    The NF-kappa B/Rel family of at least five transcription factor polypeptides is thought to function both as a developmental regulator in B cells and as a rapid response system in all cells. To examine this notion in more detail, we determined the protein contents of both the inducible and constitutive NF-kappa B/Rel activities in a pre-B-cell line, 70Z/3, and a mature B-cell line, WEHI 231. NF-kappa B p50/p65 is the major inducible nuclear complex after lipopolysaccharide or phorbol myristate acetate treatment of 70Z/3 cells. The constitutive and inducible complexes in WEHI 231 cells are mainly composed of p50 and Rel. The constitutive or induced activities are all sensitive to I kappa B-alpha, but this inhibitor is very short-lived in WEHI 231 cells, suggesting that the balance between synthesis and degradation of I kappa B-alpha determines whether a particular cell lineage has constitutive activity. A patterned expression of the NF-kappa B/Rel activator proteins emerges from an analysis of other B-lineage cell lines and splenic B cells: mainly p50 and p65 in pre-B (and non-B) cells, a predominance of Rel and p50 in mature B cells, and expression of p52 and RelB in plasmacytoma lines. This ordered pattern of regulators may reflect the requirement for expression of different genes during terminal B-cell differentiation because different combinations of NF-kappa B/Rel family members preferentially activate distinct kappa B sites in reporter constructs. Images PMID:8035813

  14. B-cell survival factors in autoimmune rheumatic disorders

    PubMed Central

    Morais, Sandra A.; Vilas-Boas, Andreia

    2015-01-01

    Autoimmune rheumatic disorders have complex etiopathogenetic mechanisms in which B cells play a central role. The importance of factors stimulating B cells, notably the B-cell activating factor (BAFF) and A proliferation inducing ligand (APRIL) axis is now recognized. BAFF and APRIL are cytokines essential for B-cell proliferation and survival from the immature stages to the development of plasma cells. Their levels are increased in some subsets of patients with autoimmune disorders. Several recent biologic drugs have been developed to block this axis, namely belimumab [already licensed for systemic lupus erythematosus (SLE) treatment], tabalumab, atacicept and blisibimod. Many clinical trials to evaluate the safety and efficacy of these drugs in several autoimmune disorders are ongoing, or have been completed recently. This review updates the information on the use of biologic agents blocking BAFF/APRIL for patients with SLE, rheumatoid arthritis, Sjögren’s syndrome and myositis. PMID:26288664

  15. Bad-deficient mice develop diffuse large B cell lymphoma

    E-print Network

    Datta, Sandeep Robert

    02115; §Division of Neuroscience, Children's Hospital Boston and Department of Neurobiology, Harvard -irradiation resulted in an increased incidence of pre-T cell and pro- pre-B cell lymphoblastic leukemia

  16. Original Research B-cell Ligand Processing Pathways Detected

    E-print Network

    Honavar, Vasant

    and bacteria to the recognition of cancerous cells. B-cells act as the body's most effective line of defense different ligands. First, we compared the degree distributions of the generated networks. Second, we

  17. COMPUTATION MODELING OF TCDD DISRUPTION OF B CELL TERMINAL DIFFERENTIATION

    EPA Science Inventory

    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.

  18. Impact of Single or Combined Genomic Alterations of TP53, MYC, and BCL2 on Survival of Patients With Diffuse Large B-Cell Lymphomas: A Retrospective Cohort Study.

    PubMed

    Schiefer, Ana-Iris; Kornauth, Christoph; Simonitsch-Klupp, Ingrid; Skrabs, Cathrin; Masel, Eva Katharina; Streubel, Berthold; Vanura, Katrina; Walter, Karin; Migschitz, Brigitta; Stoiber, Dagmar; Sexl, Veronika; Raderer, Markus; Chott, Andreas; da Silva, Maria Gomes; Cabecadas, Jose; Müllauer, Leonhard; Jäger, Ulrich; Porpaczy, Edit

    2015-12-01

    MYC and BCL2 translocations as well as TP53 deletion/mutation are known risk factors in diffuse large B-cell lymphoma (DLBCL) but their interplay is not well understood.In this retrospective cohort study, we evaluated the combined prognostic impact of TP53 deletion and mutation status, MYC and BCL2 genomic breaks in tumor samples of 101 DLBCL patients. The cohort included 53 cases with MYC rearrangements (MYC+).TP53 deletions/mutations (TP53+) were found in 32 of 101 lymphomas and were equally distributed between MYC+ and MYC- cases (35.8% vs. 27.1%). TP53+ lymphomas had lower responses to treatment than TP53- (complete remission 34.4% vs. 60.9%; P?=?0.01). TP53 alteration was the dominant independent prognostic factor in multivariate analysis (P?=?0.01). Overall survival (OS) varied considerably between subgroups with different genomic alterations: Patients with sole MYC translocation, and interestingly, with triple MYC+/BCL2+/TP53+ aberration had favorable outcomes (median OS not reached) similar to patients without genomic alterations (median OS 65 months). In contrast, patients with MYC+/BCL2+/TP53- double-hit lymphomas (DHL) (28 months), MYC+/BCL2-/TP53+ lymphomas (10 months) or sole TP53 mutation/deletion (12 months) had a poor median OS. Our findings demonstrate differences in OS of DLBCL patients depending on absence or presence of single or combined genetic alterations of MYC, BCL2, and TP53. Cooccurrence of TP53 and BCL2 aberrations ameliorated the poor prognostic impact of single TP53+ or BCL2+ in MYC positive patients.This pilot study generates evidence for the complex interplay between the alterations of genetic pathways in DLBCL, which goes beyond the concept of DHL. The variable survival of DLBCL patients dependent on single or combined alterations in the TP53, MYC, and BCL2 genes indicates the need for comprehensive genomic diagnosis. PMID:26717387

  19. Safety and Tolerability Study of PCI-32765 in B Cell Lymphoma and Chronic Lymphocytic Leukemia

    ClinicalTrials.gov

    2015-11-25

    B-cell Chronic Lymphocytic Leukemia; Small Lymphocytic Lymphoma; Diffuse Well-differentiated Lymphocytic Lymphoma; B Cell Lymphoma; Follicular Lymphoma,; Mantle Cell Lymphoma; Non-Hodgkin's Lymphoma; Waldenstrom Macroglobulinemia; Burkitt Lymphoma; B-Cell Diffuse Lymphoma

  20. Monovalent engagement of the BCR activates ovalbumin-specific transnuclear B cells

    E-print Network

    Avalos, Ana M.

    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 ...

  1. ?? T Cells Shape Preimmune Peripheral B Cell Populations.

    PubMed

    Huang, Yafei; Getahun, Andrew; Heiser, Ryan A; Detanico, Thiago O; Aviszus, Katja; Kirchenbaum, Greg A; Casper, Tamara L; Huang, Chunjian; Aydintug, M Kemal; Carding, Simon R; Ikuta, Koichi; Huang, Hua; Wysocki, Lawrence J; Cambier, John C; O'Brien, Rebecca L; Born, Willi K

    2016-01-01

    We previously reported that selective ablation of certain ?? T cell subsets, rather than removal of all ?? T cells, strongly affects serum Ab levels in nonimmunized mice. This type of manipulation also changed T cells, including residual ?? T cells, revealing some interdependence of ?? T cell populations. For example, in mice lacking V?4(+) and V?6(+) ?? T cells (B6.TCR-V?4(-/-)/6(-/-)), we observed expanded V?1(+) cells, which changed in composition and activation and produced more IL-4 upon stimulation in vitro, increased IL-4 production by ?? T cells as well as spontaneous germinal center formation in the spleen, and elevated serum Ig and autoantibodies. We therefore examined B cell populations in this and other ??-deficient mouse strains. Whereas immature bone marrow B cells remained largely unchanged, peripheral B cells underwent several changes. Specifically, transitional and mature B cells in the spleen of B6.TCR-V?4(-/-)/6(-/-) mice and other peripheral B cell populations were diminished, most of all splenic marginal zone (MZ) B cells. However, relative frequencies and absolute numbers of Ab-producing cells, as well as serum levels of Abs, IL-4, and BAFF, were increased. Cell transfers confirmed that these changes are directly dependent on the altered ?? T cells in this strain and on their enhanced potential of producing IL-4. Further evidence suggests the possibility of direct interactions between ?? T cells and B cells in the splenic MZ. Taken together, these data demonstrate the capability of ?? T cells of modulating size and productivity of preimmune peripheral B cell populations. PMID:26582947

  2. Slow CCL2-dependent translocation of biopersistent particles from muscle to brain

    PubMed Central

    2013-01-01

    Background Long-term biodistribution of nanomaterials used in medicine is largely unknown. This is the case for alum, the most widely used vaccine adjuvant, which is a nanocrystalline compound spontaneously forming micron/submicron-sized agglomerates. Although generally well tolerated, alum is occasionally detected within monocyte-lineage cells long after immunization in presumably susceptible individuals with systemic/neurologic manifestations or autoimmune (inflammatory) syndrome induced by adjuvants (ASIA). Methods On the grounds of preliminary investigations in 252 patients with alum-associated ASIA showing both a selective increase of circulating CCL2, the major monocyte chemoattractant, and a variation in the CCL2 gene, we designed mouse experiments to assess biodistribution of vaccine-derived aluminum and of alum-particle fluorescent surrogates injected in muscle. Aluminum was detected in tissues by Morin stain and particle induced X-ray emission) (PIXE) Both 500 nm fluorescent latex beads and vaccine alum agglomerates-sized nanohybrids (Al-Rho) were used. Results Intramuscular injection of alum-containing vaccine was associated with the appearance of aluminum deposits in distant organs, such as spleen and brain where they were still detected one year after injection. Both fluorescent materials injected into muscle translocated to draining lymph nodes (DLNs) and thereafter were detected associated with phagocytes in blood and spleen. Particles linearly accumulated in the brain up to the six-month endpoint; they were first found in perivascular CD11b+ cells and then in microglia and other neural cells. DLN ablation dramatically reduced the biodistribution. Cerebral translocation was not observed after direct intravenous injection, but significantly increased in mice with chronically altered blood-brain-barrier. Loss/gain-of-function experiments consistently implicated CCL2 in systemic diffusion of Al-Rho particles captured by monocyte-lineage cells and in their subsequent neurodelivery. Stereotactic particle injection pointed out brain retention as a factor of progressive particle accumulation. Conclusion Nanomaterials can be transported by monocyte-lineage cells to DLNs, blood and spleen, and, similarly to HIV, may use CCL2-dependent mechanisms to penetrate the brain. This occurs at a very low rate in normal conditions explaining good overall tolerance of alum despite its strong neurotoxic potential. However, continuously escalating doses of this poorly biodegradable adjuvant in the population may become insidiously unsafe, especially in the case of overimmunization or immature/altered blood brain barrier or high constitutive CCL-2 production. PMID:23557144

  3. Primary cutaneous T-cell-rich B-cell lymphoma. A case report with a 13-year follow-up.

    PubMed

    Dommann, S N; Dommann-Scherrer, C C; Zimmerman, D; Dours-Zimmermann, M T; Hassam, S; Burg, G

    1995-12-01

    Cutaneous B-cell lymphomas constitute approximately 20% of primary cutaneous lymphomas. Most histologic subtypes of nodal B-cell lymphomas also occur primarily in the skin. The recently described T-cell-rich B-cell lymphomas (TCRBCLs) manifest mainly in the lymph nodes. This article presents a case of TCRBCL arising primarily in the skin, the origin of which could be traced back 13 years. The patient is a 59-year-old man. Plaque-like and nodular skin infiltrates had first appeared in the left preauricular region. Repeated examinations never found any extracutaneous involvement. A skin biopsy and a retrospectively studied 10-year-old skin specimen showed identical histologic features. Immunohistochemistry identified the TCRBCL previously considered as cutaneous Hodgkin's disease or a diffuse centroblastic centrocytic non-Hodgkin's lymphoma. A clonal B-cell population was detected by polymerase chain reaction, showing a rearrangement of IgH gene. The case of this patient shows that primary cutaneous TCRBCLs, similarly to other B-cell lymphomas in the skin, may have a good prognosis, in contrast to their nodal counterparts. PMID:8599480

  4. Changes in chemokines and chemokine receptor expression on tonsillar B cells upon Epstein–Barr virus infection

    PubMed Central

    Ehlin-Henriksson, Barbro; Liang, Wu; Cagigi, Alberto; Mowafi, Frida; Klein, George; Nilsson, Anna

    2009-01-01

    Chemokines and chemokine receptors are likely to play important roles in the pathogenesis of Epstein–Barr virus (EBV) -associated disease. The primary EBV infection occurs in the oropharynx where the virus infects mainly tonsillar B cells. We have previously shown that CXCR4 expression on tonsillar B cells is modulated by EBV. Here, CXCR5 and CCR7 expression, which is important for migration into lymphoid tissue, was followed for 14 days after EBV infection of tonsillar B cells. Early after infection (2 days) there were only minor changes in CXCR5 and CCR7 expression. However, at day 7 the expression of CXCR5, as well as of CCR7, was decreased and by day 14 these molecules were no longer present at the cell surface. Furthermore, EBV infection affects the chemotactic response to CXCL13 and CCL21 (the ligands for CXCR5 and CCR7, respectively) with a reduction of ligand-induced migration at day 2. Using gene expression profiling, we identified an additional set of chemokines and chemokine receptors that were changed upon EBV infection in comparison with non-infected tonsillar B cells. In particular, messenger RNA expression for CCR9 and the complement receptor C5AR1 was increased. Both receptors mediate homing to mucosal tissue. The alterations of the expression of these molecules may lead to retention of EBV-infected tonsillar B cells in the interfollicular region of the tonsil. PMID:19604305

  5. Cutaneous primary B-cell lymphomas: from diagnosis to treatment.

    PubMed

    Lima, Margarida

    2015-10-01

    AbstractPrimary cutaneous B-cell lymphomas are a heterogeneous group of mature B-cells neoplasms with tropism for the skin, whose biology and clinical course differ significantly from the equivalent nodal lymphomas. The most indolent forms comprise the primary cutaneous marginal zone and follicle center B-cell lymphomas that despite the excellent prognosis have cutaneous recurrences very commonly. The most aggressive forms include the primary cutaneous large B-cell lymphomas, consisting in two major groups: the leg type, with poor prognosis, and others, the latter representing a heterogeneous group of lymphomas from which specific entities are supposed to be individualized over time, such as intravascular large B-cell lymphomas. Treatment may include surgical excision, radiotherapy, antibiotics, corticosteroids, interferon, monoclonal antibodies and chemotherapy, depending on the type of lymphoma and on the type and location of the skin lesions. In subtypes with good prognosis is contraindicated overtreatment and in those associated with a worse prognosis the recommended therapy relies on CHOP-like regimens associated with rituximab, assisted or not with local radiotherapy. We review the primary cutaneous B-cell lymphomas, remembering the diagnostic criteria, differential diagnosis, classification, and prognostic factors and presenting the available therapies. PMID:26560215

  6. Development and function of murine B cells lacking RANK.

    PubMed

    Perlot, Thomas; Penninger, Josef M

    2012-02-01

    RANKL-RANK signaling regulates numerous physiologic processes such as bone remodeling, lymph node organogenesis, central thermoregulation, and formation of a lactating mammary gland in pregnancy. Recently, a receptor activator of NF-?B ligand (RANKL)-blocking Ab has been approved for human use in potentially millions of osteoporosis and cancer patients. However, germline deficiencies in RANKL or receptor activator of NF-?B (RANK) also lead to strong B cell defects in mice and human patients, suggesting that RANKL-RANK inhibition could interfere with B cell physiology and thereby trigger immunologic side-effects. To address this key question--that is, whether RANKL-RANK signaling affects B cell physiology directly or the observed defects are secondary because of the severe osteopetrosis--we generated B cell-specific RANK knockout mice. We show that B cells deficient for RANK undergo normal development and do not show any obvious defects in Ab secretion, class switch recombination, or somatic hypermutation. Our data indicate that ablation of the RANKL-RANK pathway has no direct adverse effect on B cell physiology. PMID:22219325

  7. B cells with regulatory properties in transplantation tolerance

    PubMed Central

    Durand, Justine; Chiffoleau, Elise

    2015-01-01

    Induction of tolerance remains a major goal in transplantation. Indeed, despite potent immunosuppression, chronic rejection is still a real problem in transplantation. The humoral response is an important mediator of chronic rejection, and numerous strategies have been developed to target either B cells or plasma cells. However, the use of anti-CD20 therapy has highlighted the beneficial role of subpopulation of B cells, termed regulatory B cells. These cells have been characterized mainly in mice models of auto-immune diseases but emerging literature suggests their role in graft tolerance in transplantation. Regulatory B cells seem to be induced following inflammation to restrain excessive response. Different phenotypes of regulatory B cells have been described and are functional at various differentiation steps from immature to plasma cells. These cells act by multiple mechanisms such as secretion of immuno-suppressive cytokines interleukin-10 (IL-10) or IL-35, cytotoxicity, expression of inhibitory receptors or by secretion of non-inflammatory antibodies. Better characterization of the development, phenotype and mode of action of these cells seems urgent to develop novel approaches to manipulate the different B cell subsets and the response to the graft in a clinical setting. PMID:26722647

  8. B cells with regulatory properties in transplantation tolerance.

    PubMed

    Durand, Justine; Chiffoleau, Elise

    2015-12-24

    Induction of tolerance remains a major goal in transplantation. Indeed, despite potent immunosuppression, chronic rejection is still a real problem in transplantation. The humoral response is an important mediator of chronic rejection, and numerous strategies have been developed to target either B cells or plasma cells. However, the use of anti-CD20 therapy has highlighted the beneficial role of subpopulation of B cells, termed regulatory B cells. These cells have been characterized mainly in mice models of auto-immune diseases but emerging literature suggests their role in graft tolerance in transplantation. Regulatory B cells seem to be induced following inflammation to restrain excessive response. Different phenotypes of regulatory B cells have been described and are functional at various differentiation steps from immature to plasma cells. These cells act by multiple mechanisms such as secretion of immuno-suppressive cytokines interleukin-10 (IL-10) or IL-35, cytotoxicity, expression of inhibitory receptors or by secretion of non-inflammatory antibodies. Better characterization of the development, phenotype and mode of action of these cells seems urgent to develop novel approaches to manipulate the different B cell subsets and the response to the graft in a clinical setting. PMID:26722647

  9. Outer Membrane Protein A (OmpA) of Shigella flexneri 2a Induces TLR2-Mediated Activation of B Cells: Involvement of Protein Tyrosine Kinase, ERK and NF-?B

    PubMed Central

    Bhowmick, Rajsekhar; Pore, Debasis; Chakrabarti, Manoj K.

    2014-01-01

    B cells are critically important in combating bacterial infections and their differentiation into plasma cells and memory cells aids bacterial clearance and long-lasting immunity conferred by essentially all vaccines. Outer membrane protein A (OmpA) of Shigella flexneri 2a has been demonstrated to induce the production of IgG and IgA in vivo following immunization of mice through intranasal route, but the direct involvement of B cells in OmpA-mediated immune regulation was not determined. Consequently, we investigated whether OmpA can modulate B cell functions and identified the molecular events involved in OmpA-induced B cell immune response in vitro. We show that OmpA of S. flexneri 2a activates B cells to produce protective cytokines, IL-6 and IL-10 as well as facilitates their differentiation into antibody secreting cells (ASCs). The immunostimulatory properties of OmpA are attributed to the increased surface expression of MHCII and CD86 on B cells. We also report here that B cell activation by OmpA is mediated strictly through recognition by TLR2, resulting in initiation of cascades of signal transduction events, involving increased phosphorylation of protein tyrosine kinases (PTKs), ERK and I?B?, leading to nuclear translocation of NF-?B. Importantly, a TLR2 antibody diminishes OmpA-induced upregulation of MHCII and CD86 on B cell surface as well as significantly inhibits B cell differentiation and cytokine secretion. Furthermore, we illustrate that B cell differentiation into ASCs and induction of cytokine secretion by OmpA are dependent on PTKs activity. Moreover, we identify that OmpA-induced B cell differentiation is entirely dependent on ERK pathway, whereas both NF-?B and ERK are essential for cytokine secretion by B cells. Overall, our data demonstrate that OmpA of S. flexneri 2a amplifies TLR signaling in B cells and triggers B cell immune response, which is critical for the development of an effective adaptive immunity to an optimal vaccine antigen. PMID:25286253

  10. Child with Sotos phenotype and a 5:15 translocation

    SciTech Connect

    Maround, C.; Schmerler, S.; Hutcheon, R.G.

    1994-04-15

    The authors report on a 4-year-old girl with Sotos phenotype and a de novo balanced translocation between the long arms of chromosome 5 and chromosome 15 [46,XX,t(5,15)(q35;q22)]. They suggest a relationship between genetic material at 5q35 or 15q22 and the expression of an autosomal dominant gene. 18 refs., 2 figs.

  11. Identification of NAD+ Synthetase from Streptococcus sobrinus as a B-Cell-Stimulatory Protein†

    PubMed Central

    Veiga-Malta, Isabel; Duarte, Margarida; Dinis, Márcia; Madureira, Pedro; Ferreira, Paula; Videira, Arnaldo

    2004-01-01

    Streptococcus sobrinus, one agent of dental caries, secretes a protein that induces lymphocyte polyclonal activation of the host as a mechanism of immune evasion. We have isolated from culture supernatants of this bacterium a protein with murine B-cell-stimulatory properties and subsequently cloned the relevant gene. It contains an open reading frame of 825 bp encoding a polypeptide with 275 amino acid residues and a molecular mass of 30 kDa. The protein displays high sequence homology with NAD+ synthetases from several organisms, including a conserved fingerprint sequence (SGGXD) characteristic of ATP pyrophosphatases. The polypeptide was expressed in Escherichia coli as a hexahistidine-tagged protein and purified in an enzymatically active form. The recombinant NAD+ synthetase stimulates murine B cells after in vitro treatment of spleen cell cultures, as demonstrated by its ability to induce up-regulation of the expression of CD69, an early marker of lymphocyte activation. Stimulation with the recombinant NAD+ synthetase was also observed with other B-cell markers, such as CD19+, B220+, and CD21+. Cell proliferation follows the activation induced by the recombinant NAD+ synthetase. PMID:14702311

  12. Are we ready to stratify treatment for diffuse large B-cell lymphoma using molecular hallmarks?

    PubMed

    Barton, Sarah; Hawkes, Eliza A; Wotherspoon, Andrew; Cunningham, David

    2012-01-01

    The division of the heterogeneous entity of diffuse large B-cell lymphoma (DLBCL) into the ontogenic phenotypes of germinal center B-cell-like (GCB) and activated B-cell-like (ABC) is optimally determined by gene expression profiling (GEP), although simpler immunohistochemistry (IHC) algorithms are alternatively being used. The cell-of-origin (COO) classification assists in prognostication and may be predictive of response to therapy. Mounting data suggests that IHC methods of classifying COO may be inaccurate. GEP categorization of COO is superior in defining prognostically and biologically distinct DLBCL subtypes, but current barriers to its widescale use include inaccessibility, cost, and lack of methodological standardization and prospective validation. The poorer prognosis of ABC-DLBCL is frequently associated with constitutive activity in the NF-?B pathway and aberrations in upstream or downstream regulators of this pathway. The molecular mechanisms underlying lymphomagenesis in GCB-DLBCL are arguably less well defined, but C-REL amplification and mutations in BCL-2 and EZH2 are common. New technologies, such as next-generation sequencing, are rapidly revealing novel pathogenic genetic aberrations, and DLBCL treatment strategies are increasingly being designed focusing on distinctive pathogenic drivers within ontogenic phenotypes. This review examines emerging molecular targets and novel therapeutic agents in DLBCL, and discusses whether stratifying therapy for DLBCL using molecular features is merited by current preclinical and clinical evidence. PMID:23086691

  13. Age-related aspects of human IgM(+) B cell heterogeneity.

    PubMed

    Martin, Victoria; Wu, Yu-Chang; Kipling, David; Dunn-Walters, Deborah K

    2015-12-01

    The CD27(+) IgD(+) B cell population, known as IgM memory, reduces with age. It is thought that this population is responsible for pneumococcal polysaccharide T-independent responses, and that the age-related reduction might be partially responsible for the increased susceptibility of older people to bacterial pathogens. There are other IgM(+) B cell populations that do not express IgD. We compared the different IgM populations using high-throughput sequencing of the immunoglobulin (Ig) gene repertoire and multidimensional cell phenotyping and found that the different populations of IgM cells, defined by CD27 and IgD expression, have repertoire differences. Some of these differences are likely indicative of different selection pressures in an immune response, although the older individuals were found to have a changed repertoire in naive B cells, which may contribute to some of the changes seen in memory cells. In addition, even within the CD27(+) IgD(+) IgM memory population there are multiple cell types. We show that the level of IgM expression varies substantially and hypothesize that this distinguishes between T-dependent and T-independent types of IgM memory cells. Significant age-related changes in the relative proportions of these populations may exacerbate the reduction in T-independent responders in old age. PMID:26152370

  14. The NF-?B Genomic Landscape in Lymphoblastoid B-cells

    PubMed Central

    Zhao, Bo; Barrera, Luis A.; Ersing, Ina; Willox, Bradford; Schmidt, Stefanie C.S.; Greenfeld, Hannah; Zhou, Hufeng; Mollo, Sarah B.; Shi, Tommy T.; Takasaki, Kaoru; Jiang, Sizun; Cahir-McFarland, Ellen; Kellis, Manolis; Bulyk, Martha L.; Kieff, Elliott; Gewurz, Benjamin E.

    2014-01-01

    The nuclear factor B (NF-?B) subunits RelA, RelB, cRel, p50 and p52 are each critical for B-cell development and function. To systematically characterize their responses to canonical and non-canonical NF-?B pathway activity, we performed ChIP-seq analysis in lymphoblastoid B-cells (LCLs). We found a complex NF-?B binding landscape, which did not readily reflect the two NF-?B pathway paradigm. Instead, ten subunit binding patterns were observed at promoters and eleven at enhancers. Nearly one-third of NF-?B binding sites lacked ?B motifs and were instead enriched for alternative motifs. The oncogenic forkhead box protein FOXM1 co-occupied nearly half of NF-?B binding sites, and was identified in protein complexes with NF-?B on DNA. FOXM1 knockdown decreased NF-?B target gene expression, and ultimately induced apoptosis, highlighting FOXM1 as a synthetic lethal target in B-cell malignancy. These studies provide a resource for understanding mechanisms that underlie NF-?B nuclear activity, and highlight opportunities for selective NF-?B blockade. PMID:25159142

  15. Whole-epigenome analysis in multiple myeloma reveals DNA hypermethylation of B cell-specific enhancers.

    PubMed

    Agirre, Xabier; Castellano, Giancarlo; Pascual, Marien; Heath, Simon; Kulis, Marta; Segura, Victor; Bergmann, Anke; Esteve, Anna; Merkel, Angelika; Raineri, Emanuele; Agueda, Lidia; Blanc, Julie; Richardson, David; Clarke, Laura; Datta, Avik; Russiñol, Nuria; Queirós, Ana C; Beekman, Renée; Rodríguez-Madoz, Juan R; San José-Enériz, Edurne; Fang, Fang; Gutiérrez, Norma C; García-Verdugo, José M; Robson, Michael I; Schirmer, Eric C; Guruceaga, Elisabeth; Martens, Joost H A; Gut, Marta; Calasanz, Maria J; Flicek, Paul; Siebert, Reiner; Campo, Elías; Miguel, Jesús F San; Melnick, Ari; Stunnenberg, Hendrik G; Gut, Ivo G; Prosper, Felipe; Martín-Subero, José I

    2015-04-01

    While analyzing the DNA methylome of multiple myeloma (MM), a plasma cell neoplasm, by whole-genome bisulfite sequencing and high-density arrays, we observed a highly heterogeneous pattern globally characterized by regional DNA hypermethylation embedded in extensive hypomethylation. In contrast to the widely reported DNA hypermethylation of promoter-associated CpG islands (CGIs) in cancer, hypermethylated sites in MM, as opposed to normal plasma cells, were located outside CpG islands and were unexpectedly associated with intronic enhancer regions defined in normal B cells and plasma cells. Both RNA-seq and in vitro reporter assays indicated that enhancer hypermethylation is globally associated with down-regulation of its host genes. ChIP-seq and DNase-seq further revealed that DNA hypermethylation in these regions is related to enhancer decommissioning. Hypermethylated enhancer regions overlapped with binding sites of B cell-specific transcription factors (TFs) and the degree of enhancer methylation inversely correlated with expression levels of these TFs in MM. Furthermore, hypermethylated regions in MM were methylated in stem cells and gradually became demethylated during normal B-cell differentiation, suggesting that MM cells either reacquire epigenetic features of undifferentiated cells or maintain an epigenetic signature of a putative myeloma stem cell progenitor. Overall, we have identified DNA hypermethylation of developmentally regulated enhancers as a new type of epigenetic modification associated with the pathogenesis of MM. PMID:25644835

  16. Whole-epigenome analysis in multiple myeloma reveals DNA hypermethylation of B cell-specific enhancers

    PubMed Central

    Castellano, Giancarlo; Pascual, Marien; Heath, Simon; Kulis, Marta; Segura, Victor; Bergmann, Anke; Esteve, Anna; Merkel, Angelika; Raineri, Emanuele; Agueda, Lidia; Blanc, Julie; Richardson, David; Clarke, Laura; Datta, Avik; Russiñol, Nuria; Queirós, Ana C.; Beekman, Renée; Rodríguez-Madoz, Juan R.; José-Enériz, Edurne San; Fang, Fang; Gutiérrez, Norma C.; García-Verdugo, José M.; Robson, Michael I.; Schirmer, Eric C.; Guruceaga, Elisabeth; Martens, Joost H.A.; Gut, Marta; Calasanz, Maria J.; Flicek, Paul; Siebert, Reiner; Campo, Elías; Miguel, Jesús F. San; Melnick, Ari; Stunnenberg, Hendrik G.; Gut, Ivo G.

    2015-01-01

    While analyzing the DNA methylome of multiple myeloma (MM), a plasma cell neoplasm, by whole-genome bisulfite sequencing and high-density arrays, we observed a highly heterogeneous pattern globally characterized by regional DNA hypermethylation embedded in extensive hypomethylation. In contrast to the widely reported DNA hypermethylation of promoter-associated CpG islands (CGIs) in cancer, hypermethylated sites in MM, as opposed to normal plasma cells, were located outside CpG islands and were unexpectedly associated with intronic enhancer regions defined in normal B cells and plasma cells. Both RNA-seq and in vitro reporter assays indicated that enhancer hypermethylation is globally associated with down-regulation of its host genes. ChIP-seq and DNase-seq further revealed that DNA hypermethylation in these regions is related to enhancer decommissioning. Hypermethylated enhancer regions overlapped with binding sites of B cell-specific transcription factors (TFs) and the degree of enhancer methylation inversely correlated with expression levels of these TFs in MM. Furthermore, hypermethylated regions in MM were methylated in stem cells and gradually became demethylated during normal B-cell differentiation, suggesting that MM cells either reacquire epigenetic features of undifferentiated cells or maintain an epigenetic signature of a putative myeloma stem cell progenitor. Overall, we have identified DNA hypermethylation of developmentally regulated enhancers as a new type of epigenetic modification associated with the pathogenesis of MM. PMID:25644835

  17. Prostaglandin EP4 receptor enhances BCR-induced apoptosis of immature B cells.

    PubMed

    Prijatelj, Matevz; Celhar, Teja; Mlinaric-Rascan, Irena

    2011-08-01

    Prostaglandin E2 (PGE2) is emerging as an important co-modulator of B cell responses. Using a pharmacological approach, we aimed to delineate the role of PGE2 in B cell receptor (BCR) induced apoptosis of immature B cells. Gene and protein expression analyses showed that, of the four PGE2 receptors subtypes, only EP4 receptor is upregulated upon BCR cross-linking, leading to sensitization of WEHI 231 cells towards PGE2 mediated inhibitory effects. EP4 receptor antagonist ONO-AE3-208, was able to completely revert the observed effects of PGE2. The engagement of EP4 receptor promotes BCR-induced G0/G1 arrest of WEHI 231 cells, resulting in enhanced caspase mediated, BCR-induced apoptosis. We addressed, mechanistically, the interplay between BCR and EP4 receptor signaling components. Prostaglandin1-alcohol (Pge1-OH), a selective EP4 receptor agonist inhibits BCR-induced activation of NF-?B by suppression of BCR-induced I?B? phosphorylation. Disruption of prosurvival pathways is a possible mechanism by which PGE2 enhances BCR-induced apoptosis in immature B lymphocytes. PMID:21600299

  18. The autoimmunity-associated BLK haplotype exhibits cis-regulatory effects on mRNA and protein expression that are prominently observed in B cells early in development.

    PubMed

    Simpfendorfer, Kim R; Olsson, Lina M; Manjarrez Orduño, Nataly; Khalili, Houman; Simeone, Alyssa M; Katz, Matthew S; Lee, Annette T; Diamond, Betty; Gregersen, Peter K

    2012-09-01

    The gene B lymphocyte kinase (BLK) is associated with rheumatoid arthritis, systemic lupus erythematosus and several other autoimmune disorders. The disease risk haplotype is known to be associated with reduced expression of BLK mRNA transcript in human B cell lines; however, little is known about cis-regulation of BLK message or protein levels in native cell types. Here, we show that in primary human B lymphocytes, cis-regulatory effects of disease-associated single nucleotide polymorphisms in BLK are restricted to naïve and transitional B cells. Cis-regulatory effects are not observed in adult B cells in later stages of differentiation. Allelic expression bias was also identified in primary human T cells from adult peripheral and umbilical cord blood (UCB), thymus and tonsil, although mRNA levels were reduced compared with B cells. Allelic regulation of Blk expression at the protein level was confirmed in UCB B cell subsets by intracellular staining and flow cytometry. Blk protein expression in CD4(+) and CD8(+) T cells was documented by western blot analysis; however, differences in protein expression levels by BLK genotype were not observed in any T cell subset. Blk allele expression differences at the protein level are thus restricted to early B cells, indicating that the involvement of Blk in the risk for autoimmune disease likely acts during the very early stages of B cell development. PMID:22678060

  19. The B-cell receptor orchestrates environment-mediated lymphoma survival and drug resistance in B-cell malignancies

    PubMed Central

    Shain, KH; Tao, J

    2015-01-01

    Specific niches within the lymphoma tumor microenvironment (TME) provide sanctuary for subpopulations of tumor cells through stromal cell–tumor cell interactions. These interactions notably dictate growth, response to therapy and resistance of residual malignant B cells to therapeutic agents. This minimal residual disease (MRD) remains a major challenge in the treatment of B-cell malignancies and contributes to subsequent disease relapse. B-cell receptor (BCR) signaling has emerged as essential mediator of B-cell homing, survival and environment-mediated drug resistance (EMDR). Central to EMDR are chemokine- and integrin-mediated interactions between lymphoma and the TME. Further, stromal cell–B cell adhesion confers a sustained BCR signaling leading to chemokine and integrin activation. Recently, the inhibitors of BCR signaling have garnered a substantial clinical interest because of their effectiveness in B-cell disorders. The efficacy of these agents is, at least in part, attributed to attenuation of BCR-dependent lymphoma–TME interactions. In this review, we discuss the pivotal role of BCR signaling in the integration of intrinsic and extrinsic determinants of TME-mediated lymphoma survival and drug resistance. PMID:24037527

  20. Identification of genome-specific transcripts in wheat–rye translocation lines

    PubMed Central

    Lee, Tong Geon; Seo, Yong Weon

    2015-01-01

    Studying gene expression in wheat–rye translocation lines is complicated due to the presence of homeologs in hexaploid wheat and high levels of synteny between wheat and rye genomes (Naranjo and Fernandez-Rueda, 1991 [1]; Devos et al., 1995 [2]; Lee et al., 2010 [3]; Lee et al., 2013 [4]). To overcome limitations of current gene expression studies on wheat–rye translocation lines and identify genome-specific transcripts, we developed a custom Roche NimbleGen Gene Expression microarray that contains probes derived from the sequence of hexaploid wheat, diploid rye and diploid progenitors of hexaploid wheat genome (Lee et al., 2014). Using the array developed, we identified genome-specific transcripts in a wheat–rye translocation line (Lee et al., 2014). Expression data are deposited in the NCBI Gene Expression Omnibus (GEO) under accession number GSE58678. Here we report the details of the methods used in the array workflow and data analysis. PMID:26484243

  1. Activation-induced cytidine deaminase in B cells of hepatits C virus-related cryoglobulinaemic vasculitis.

    PubMed

    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. PMID:26219420

  2. MicroRNA-146a modulates B-cell oncogenesis by regulating Egr1

    PubMed Central

    Contreras, Jorge R.; Palanichamy, Jayanth Kumar; Tran, Tiffany M.; Fernando, Thilini R.; Rodriguez-Malave, Norma I.; Goswami, Neha; Arboleda, Valerie A.; Casero, David; Rao, Dinesh S.

    2015-01-01

    miR-146a is a NF-?B induced microRNA that serves as a feedback regulator of this critical pathway. In mice, deficiency of miR-146a results in hematolymphoid cancer at advanced ages as a consequence of constitutive NF-?B activity. In this study, we queried whether the deficiency of miR-146a contributes to B-cell oncogenesis. Combining miR-146a deficiency with transgenic expression of c-Myc led to the development of highly aggressive B-cell malignancies. Mice transgenic for c-Myc and deficient for miR-146a were characterized by significantly shortened survival, increased lymph node involvement, differential involvement of the spleen and a mature B-cell phenotype. High-throughput sequencing of the tumors revealed significant dysregulation of approximately 250 genes. Amongst these, the transcription factor Egr1 was consistently upregulated in mice deficient for miR-146a. Interestingly, transcriptional targets of Egr1 were enriched in both the high-throughput dataset and in a larger set of miR-146a-deficient tumors. miR-146a overexpression led to downregulation of Egr1 and downstream targets with concomitant decrease in cell growth. Direct targeting of the human EGR1 by miR-146a was seen by luciferase assay. Together our findings illuminate a bona fide role for miR-146a in the modulation of B-cell oncogenesis and reveal the importance of understanding microRNA function in a cell- and disease-specific context. PMID:25906746

  3. The LRF transcription factor regulates mature B cell development and the germinal center response in mice

    PubMed Central

    Sakurai, Nagisa; Maeda, Manami; Lee, Sung-Uk; Ishikawa, Yuichi; Li, Min; Williams, John C.; Wang, Lisheng; Su, Leila; Suzuki, Mai; Saito, Toshiki I.; Chiba, Shigeru; Casola, Stefano; Yagita, Hideo; Teruya-Feldstein, Julie; Tsuzuki, Shinobu; Bhatia, Ravi; Maeda, Takahiro

    2011-01-01

    B cells play a central role in immune system function. Deregulation of normal B cell maturation can lead to the development of autoimmune syndromes as well as B cell malignancies. Elucidation of the molecular features of normal B cell development is important for the development of new target therapies for autoimmune diseases and B cell malignancies. Employing B cell–specific conditional knockout mice, we have demonstrated here that the transcription factor leukemia/lymphoma-related factor (LRF) forms an obligate dimer in B cells and regulates mature B cell lineage fate and humoral immune responses via distinctive mechanisms. Moreover, LRF inactivation in transformed B cells attenuated their growth rate. These studies identify what we believe to be a new key factor for mature B cell development and provide a rationale for targeting LRF dimers for the treatment of autoimmune diseases and B cell malignancies. PMID:21646720

  4. Cell-Cycle-Dependent Reconfiguration of the DNA Methylome during Terminal Differentiation of Human B Cells into Plasma Cells.

    PubMed

    Caron, Gersende; Hussein, Mourad; Kulis, Marta; Delaloy, Céline; Chatonnet, Fabrice; Pignarre, Amandine; Avner, Stéphane; Lemarié, Maud; Mahé, Elise A; Verdaguer-Dot, Núria; Queirós, Ana C; Tarte, Karin; Martín-Subero, José I; Salbert, Gilles; Fest, Thierry

    2015-11-01

    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-?1/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 (hydroxy)methylation, and cell fate determination. PMID:26565917

  5. Chromosome abnormalities in diffuse large B-cell lymphomas: analysis of 231 Chinese patients.

    PubMed

    Zhao, Xiaoli; Fan, Rong; Lin, Guowei; Wang, Xiaoqin

    2013-09-01

    Genome instability is a hallmark of cancer. Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma with high levels of chromosomal aberrations. The purpose of this study was to characterize chromosomal aberrations in Chinese DLBCL patients and to compare chromosomal abnormalities between germinal centre B-cell-like (GCB) and non-GCB subgroups. Fluorescence in situ hybridization, G-band cytogenetics and immunohistochemistry were performed in 231 cases of de novo DLBCL. We demonstrated that the rate of abnormal and complex karyotypes was 89.1% (139/156) and 92.8% (129/139), respectively. We found a total of 490 structural chromosomal aberrations, including 96 frequent and recurring structural alterations. Most importantly, we identified several rare or novel chromosomal alterations: eight gains (5, 13, 14q, 17, 19p, 20, 21p, Y), one loss (21) and three recurrent translocations [t(7;15)(q22;q22), t(3;20)(p24;q13.1), t(2;3)(q21;q25)]. Moreover, the frequent recurrent genomic imbalance between GCB and non-GCB subgroups was different. Finally, we discovered two cases of concurrent IGH-BCL6 and MYC rearrangements. The rate of abnormal karyotypes in DLBCL patients of Chinese descent was similar to that of Western countries, but some common karyotypes were different, as were the abnormal karyotypes of GCB and non-GCB subgroups. Our discovery of rare and novel abnormal karyotypes may represent unique chromosomal alterations in Chinese DLBCL patients. PMID:23135954

  6. Dynamic regulation of CD24 expression and release of CD24-containing microvesicles in immature B cells in response to CD24 engagement.

    PubMed

    Ayre, D Craig; Elstner, Marcus; Smith, Nicole C; Moores, Emily S; Hogan, Andrew M; Christian, Sherri L

    2015-10-01

    The glycophosphatidylinositol-anchored cell surface receptor CD24 (also called heat-stable antigen) promotes the apoptosis of progenitor and precursor B-lymphocytes. However, the immediate proximal events that occur after engagement of CD24 in B cells are not precisely understood. Using a bioinformatics analysis of mouse (Mus musculus) gene expression data from the Immunological Genome Project, we found that known vesicle trafficking and cellular organization genes have similar expression patterns to CD24 during B-cell development in the bone marrow. We therefore hypothesized that CD24 regulates vesicle trafficking. We first validated that antibody-mediated engagement of CD24 induces apoptosis in the mouse WEHI-231 cell line and mouse primary bone marrow-derived B cells. We next found that CD24 surface protein expression is rapidly and dynamically regulated in both WEHI-231 cells and primary immature B cells in response to engagement of CD24. The change in surface expression was not mediated by classical endocytosis or exocytosis. However, we found that CD24-bearing plasma membrane-derived extracellular microvesicles were released in response to CD24 engagement. Furthermore, in response to CD24 engagement we observed a clear exchange of CD24 between different populations of B cells. Hence, we show that engagement of CD24 in immature B cells results in a dynamic regulation of surface CD24 protein and a redistribution of CD24 within the population. PMID:26059947

  7. Nature and nurture: a case of transcending haematological pre-malignancies in a pair of monozygotic twins adding possible clues on the pathogenesis of B-cell proliferations.

    PubMed

    Hansen, Marcus C; Nyvold, Charlotte G; Roug, Anne S; Kjeldsen, Eigil; Villesen, Palle; Nederby, Line; Hokland, Peter

    2015-05-01

    We describe a comprehensive molecular analysis of a pair of monozygotic twins, who came to our attention when one experienced amaurosis fugax and was diagnosed with JAK2+ polycythaemia vera. He (Twin A) was also found to have an asymptomatic B-cell chronic lymphocytic leukaemia (B-CLL). Although JAK2-, Twin B was subsequently shown to have a benign monoclonal B-cell lymphocytosis (MBL). Flow cytometric and molecular analyses of the B-cell compartments revealed different immunoglobulin light and heavy chain usage in each twin. We hypothesized that whole exome sequencing could help delineating the pattern of germline B-cell disorder susceptibility and reveal somatic mutations potentially contributing to the differential patterns of pre-malignancy. Comparing bone marrow cells and T cells and employing in-house engineered integrative analysis, we found aberrations in Twin A consistent with a myeloid neoplasm, i.e. in TET2, RUNX1, PLCB1 and ELF4. Employing the method for detecting high-ranking variants by extensive annotation and relevance scoring, we also identified shared germline variants in genes of proteins interacting with B-cell receptor signalling mediators and the WNT-pathway, including IRF8, PTPRO, BCL9L, SIT1 and SIRPB1, all with possible implications in B-cell proliferation. Similar patterns of IGHV-gene usage to those demonstrated here have been observed in inherited acute lymphoblastic leukaemia. Collectively, these findings may help in facilitating identification of putative master gene(s) involved in B-cell proliferations in general and MBL and B-CLL in particular. PMID:25752595

  8. TIM-1 signaling in B cells regulates antibody production

    SciTech Connect

    Ma, Juan; Usui, Yoshihiko; Department of Ophthalmology, Tokyo Medical University, 6-7-1 Nishi-shinjuku-ku, Tokyo 160-0023 ; Takeda, Kazuyoshi; Harada, Norihiro; Department of Respiratory Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421; Research Institute for Diseases of Old Ages, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 ; Yagita, Hideo; Okumura, Ko; Akiba, Hisaya

    2011-03-11

    Highlights: {yields} TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. {yields} Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. {yields} TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3{sup +} anti-CD28-stimulated CD4{sup +} T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.

  9. Observation and prediction of recurrent human translocations mediated by NAHR between nonhomologous chromosomes

    PubMed Central

    Ou, Zhishuo; Stankiewicz, Pawe?; Xia, Zhilian; Breman, Amy M.; Dawson, Brian; Wiszniewska, Joanna; Szafranski, Przemyslaw; Cooper, M. Lance; Rao, Mitchell; Shao, Lina; South, Sarah T.; Coleman, Karlene; Fernhoff, Paul M.; Deray, Marcel J.; Rosengren, Sally; Roeder, Elizabeth R.; Enciso, Victoria B.; Chinault, A. Craig; Patel, Ankita; Kang, Sung-Hae L.; Shaw, Chad A.; Lupski, James R.; Cheung, Sau W.

    2011-01-01

    Four unrelated families with the same unbalanced translocation der(4)t(4;11)(p16.2;p15.4) were analyzed. Both of the breakpoint regions in 4p16.2 and 11p15.4 were narrowed to large ?359-kb and ?215-kb low-copy repeat (LCR) clusters, respectively, by aCGH and SNP array analyses. DNA sequencing enabled mapping the breakpoints of one translocation to 24 bp within interchromosomal paralogous LCRs of ?130 kb in length and 94.7% DNA sequence identity located in olfactory receptor gene clusters, indicating nonallelic homologous recombination (NAHR) as the mechanism for translocation formation. To investigate the potential involvement of interchromosomal LCRs in recurrent chromosomal translocation formation, we performed computational genome-wide analyses and identified 1143 interchromosomal LCR substrate pairs, >5 kb in size and sharing >94% sequence identity that can potentially mediate chromosomal translocations. Additional evidence for interchromosomal NAHR mediated translocation formation was provided by sequencing the breakpoints of another recurrent translocation, der(8)t(8;12)(p23.1;p13.31). The NAHR sites were mapped within 55 bp in ?7.8-kb paralogous subunits of 95.3% sequence identity located in the ?579-kb (chr 8) and ?287-kb (chr 12) LCR clusters. We demonstrate that NAHR mediates recurrent constitutional translocations t(4;11) and t(8;12) and potentially many other interchromosomal translocations throughout the human genome. Furthermore, we provide a computationally determined genome-wide “recurrent translocation map.” PMID:21205869

  10. Ibrutinib Before and After Stem Cell Transplant in Treating Patients With Relapsed or Refractory Diffuse Large B-cell Lymphoma

    ClinicalTrials.gov

    2015-12-14

    B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma

  11. B cells as effectors and regulators of autoimmunity.

    PubMed

    Mariño, Eliana; Grey, Shane T

    2012-08-01

    A classic understanding of the interplay between B and T cell components of the immune system that drive autoimmunity, where B cells provide an effector function, is represented by systemic lupus erythematosus (SLE), an autoimmune condition characterised by the production of auto-antibodies. In SLE, CD4+T cells provide cognate help to self-reactive B cells, which in turn produce pathogenic auto-antibodies (1). Thus, B cells act as effectors by producing auto-antibody aided by T cell help such that B and T cell interactions are unidirectional. However, this paradigm of B and T cell interactions is challenged by new clinical data demonstrating that B cell depletion is effective for T cell mediated autoimmune diseases including type I diabetes mellitus (T1D) (2), rheumatoid arthritis (3), and multiple sclerosis (4). These clinical data indicate a model whereby B cells can influence the developing autoimmune T cell response, and therefore act as effectors, in ways that extend beyond the production of autoantibody (5). In this review by largely focusing on type I diabetes we will develop a hypothesis that bi-directional B and T interactions control the course of autoimmunity. PMID:22432804

  12. The Role of Latently Infected B Cells in CNS Autoimmunity

    PubMed Central

    Márquez, Ana Citlali; Horwitz, Marc Steven

    2015-01-01

    The onset of multiple sclerosis (MS) is caused by both genetic and environmental factors. Among the environmental factors, it is believed that previous infection with Epstein–Barr virus (EBV) may contribute in the development of MS. EBV has been associated with other autoimmune diseases, such as systemic lupus erythematous, and cancers like Burkitt’s lymphoma. EBV establishes a life-long latency in B cells with occasional reactivation of the virus throughout the individual’s life. The role played by B cells in MS pathology has been largely studied, yet is not clearly understood. In MS patients, Rituximab, a novel treatment that targets CD20+ B cells, has proven to have successful results in diminishing the number of relapses in remitting relapsing MS; however, the mechanism of how this drug acts has not been clearly established. In this review, we analyze the evidence of how B cells latently infected with EBV might be altering the immune system response and helping in the development of MS. We will also discuss how animal models, such as experimental autoimmune encephalomyelitis (EAE) and murine gammaherpesvirus-68 (?HV-68), can be used as powerful tools in the study of the relationship between EBV, MS, and B cells. PMID:26579121

  13. Perinatal immunotoxicity of benzene toward mouse B cell development

    SciTech Connect

    Wierda, D.; King, A.; Luebke, R.; Reasor, M.; Smialowicz, R.J.

    1989-01-01

    Benzene is widely used by chemical industries and exposure to benzene has been shown experimentally to be immunotoxic in adult animals. The present study addressed whether exposure of fetuses in utero to benzene compromises the development of fetal B lymphopoiesis and whether B-lymphocyte development recovers postnatally. Pregnant BALB/C dams were given intraperitoneal injections of benzene (100 mg/kg, twice daily) from day 12.5 of gestation through day 19.5 of gestation. Phenotypic analysis revealed that fetal liver cell suspensions from embryos exposed in utero contained fewer pre-B cells and B cells than corresponding controls. Fetal liver cell cultures established from these embryos also produced fewer B cells. In contrast, pre-B cells were elevated in the livers of 8-day-old neonates that had been exposed to benzene in utero. Moreover, responsiveness to the B-cell mitogen, LPS, was significantly decreased in spleen cell cultures derived from these neonates. The results indicate that in utero exposure to high concentrations of benzene alters fetal B lymphopoiesis and may compromise immune responsiveness postnatally.

  14. Tourette syndrome in a pedigree with a 7;18 translocation: Identification of a YAC spanning the translocation breakpoint at 18q22.3

    SciTech Connect

    Boghosian-Sell, L.; Overhauser, J.; Comings, D.E.

    1996-11-01

    Tourette syndrome is a neuropsychiatric disorder characterized by the presence of multiple, involuntary motor and vocal tics. Associated pathologies include attention deficit disorder and obsessive-compulsive disorder (OCD). Extensive linkage analysis based on an autosomal dominant mode of transmission with reduced penetrance has failed to show linkage with polymorphic markers, suggesting either locus heterogeneity or a polygenic origin for Tourette syndrome. An individual diagnosed with Tourette syndrome has been described carrying a constitutional chromosome translocation. Other family members carrying the translocation exhibit features seen in Tourette syndrome including motor tics, vocal tics, and OCD. Since the disruption of specific genes by a chromosomal rearrangement can elicit a particular phenotype, we have undertaken the physical mapping of the 7;18 translocation such that genes mapping at the site of the breakpoint can be identified and evaluated for a possible involvement in Tourette syndrome. Using somatic cell hybrids retaining either the der(7) or the der(18), a more precise localization of the breakpoints on chromosomes 7 and 18 have been determined. Furthermore, physical mapping has identified two YAC clones that span the translocation breakpoint on chromosome 18 as determined by FISH. These YAC clones will be useful for the eventual identification of genes that map to chromosomes 7 and 18 at the site of the translocation. 41 refs., 3 figs., 1 tab.

  15. In vitro identification of human pro-B cells that give rise to macrophages, natural killer cells, and T cells.

    PubMed

    Reynaud, Damien; Lefort, Nathalie; Manie, Elodie; Coulombel, Laure; Levy, Yves

    2003-06-01

    In this study we report the molecular and functional characterization of very early interleukin 7 receptor alpha (IL-7Ralpha)+-CD79a+CD19- B-cell progenitors, produced by human CD34+CD19-CD10- cord blood cells grown in the presence of stromal cells and cytokines. Purified IL-7Ralpha+CD79a+CD19- cells transcribed the B-lymphoid specific genes E2A, EBF, TdT, Rag-1, had initiated DJH rearrangements, but almost lacked Pax-5 mRNA. When exposed to appropriate environmental conditions, these cells repressed B-cell genes and completely differentiated into CD14+ macrophages, CD56+ natural killer cells, and CD4high T cells. Retention of the DJH rearranged genes in both CD14+ and CD56+ cells unambiguously demonstrates that early B-cell genes, expressed prior to Pax-5, can be activated in a multipotent human progenitor cell whose final fate, including in non-B lineages, is determined by external signals. PMID:12560235

  16. Suppression of IL-10 production by activated B cells via a cell contact-dependent cyclooxygenase-2 pathway upregulated in IFN-?-treated mesenchymal stem cells.

    PubMed

    Hermankova, Barbora; Zajicova, Alena; Javorkova, Eliska; Chudickova, Milada; Trosan, Peter; Hajkova, Michaela; Krulova, Magdalena; Holan, Vladimir

    2016-02-01

    The immunoregulatory properties of mesenchymal stem cells (MSCs) have been well documented in various models in vitro and in vivo. Furthermore, a population of regulatory B cells (Bregs) that produce relatively high concentrations of IL-10 has been recently described. To study the relationship between MSCs and Bregs, we analyzed the effects of MSCs on IL-10 production by lipopolysaccharide (LPS)-activated mouse B cells. The production of IL-10 by B cells remained preserved in the presence of MSCs and was even significantly enhanced by IFN-?. However, the production of IL-10 was strongly suppressed in cultures containing MSCs and IFN-?. Preincubation of MSCs, but not of B cells, with IFN-? induced the suppression of IL-10 secretion in cultures containing MSCs and B cells. The supernatants from IFN-?-treated MSCs had no inhibitory effect, and the suppression of IL-10 production was abrogated if the MSCs and B cells were separated in a transwell system. Analysis of the gene expression of IFN-?- or IFN-? and LPS-treated MSCs revealed a strong upregulation of genes for indoleamine-2,3-dioxygenase (IDO), cyclooxygenase-2 (Cox-2) and programmed cell death-ligand 1 (PD-L1). While the inhibition of IDO activity or the inclusion of the neutralization monoclonal antibody anti-PD-L1 did not abrogate the suppression, indomethacin, an inhibitor of Cox-2, completely inhibited the MSC-mediated suppression of IL-10 production. Accordingly, the production of IL-10 by B cells was inhibited by exogenous prostaglandin E2. The results thus suggest that IFN-?-treated MSCs strongly inhibit IL-10 production by activated B cells by a mechanism requiring cell contact and involving the Cox-2 pathway. PMID:26416211

  17. Novel Therapies for Aggressive B-Cell Lymphoma

    PubMed Central

    Foon, Kenneth A.; Takeshita, Kenichi; Zinzani, Pier L.

    2012-01-01

    Aggressive B-cell lymphoma (BCL) comprises a heterogeneous group of malignancies, including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma, and mantle cell lymphoma (MCL). DLBCL, with its 3 subtypes, is the most common type of lymphoma. Advances in chemoimmunotherapy have substantially improved disease control. However, depending on the subtype, patients with DLBCL still exhibit substantially different survival rates. In MCL, a mature B-cell lymphoma, the addition of rituximab to conventional chemotherapy regimens has increased response rates, but not survival. Burkitt lymphoma, the most aggressive BCL, is characterized by a high proliferative index and requires more intensive chemotherapy regimens than DLBCL. Hence, there is a need for more effective therapies for all three diseases. Increased understanding of the molecular features of aggressive BCL has led to the development of a range of novel therapies, many of which target the tumor in a tailored manner and are summarized in this paper. PMID:22536253

  18. How do viruses trick B-cells into becoming lymphomas?

    PubMed Central

    Cesarman, Ethel

    2014-01-01

    Purpose of review Since the discovery of EBV in Burkitt lymphoma 50 years ago, only one other virus, namely KSHV/HHV-8, has been confirmed to be a direct cause of B cell lymphoma. Here we will review the evidence for EBV and KSHV as causal lymphoma agents. Recent findings A deeper understanding of specific mechanisms by which EBV and KSHV cause B cell lymphomas has been acquired over the past years, in particular with respect to viral protein interactions with host cell pathways, microRNA functions. Specific therapies based on knowledge of viral functions are beginning to be evaluated, mostly in pre-clinical models. Summary Understanding the causal associations of specific infections agents with certain B cell lymphomas has allowed more accurate diagnosis and classification. A deeper knowledge of the specific mechanisms of transformation is essential to begin assessing whether virus-targeted treatment modalities may be used in the future. PMID:24886824

  19. The epigenetic basis of diffuse large B-cell lymphoma.

    PubMed

    Jiang, Yanwen; Melnick, Ari

    2015-04-01

    The pathogenesis of diffuse large B-cell lymphoma (DLBCL) is strongly linked to perturbation of epigenetic mechanisms. The germinal center (GC) B cells from which DLBCLs arise are prone to instability in their cytosine methylation patterns. DLBCLs inherit this epigenetic instability and display variable degrees of epigenetic heterogeneity. Greater epigenetic heterogeneity is linked with poor clinical outcome. Somatic mutations of histone-modifying proteins have also emerged as a hallmark of DLBCL. The effect of these somatic mutations may be to disrupt epigenetic switches that control the GC phenotype and "lock in" certain oncogenic features of GC B cells, resulting in malignant transformation. DNA methyltransferase and histone methyltransferase inhibitors are emerging as viable therapeutic approaches to erase aberrant epigenetic programming, suppress DLBCL growth, and overcome chemotherapy resistance. This review will discuss these recent advances and their therapeutic implications. PMID:25805588

  20. Problems with mitigation translocation of herpetofauna.

    PubMed

    Sullivan, Brian K; Nowak, Erika M; Kwiatkowski, Matthew A

    2015-02-01

    Mitigation translocation of nuisance animals is a commonly used management practice aimed at resolution of human-animal conflict by removal and release of an individual animal. Long considered a reasonable undertaking, especially by the general public, it is now known that translocated subjects are negatively affected by the practice. Mitigation translocation is typically undertaken with individual adult organisms and has a much lower success rate than the more widely practiced conservation translocation of threatened and endangered species. Nonetheless, the public and many conservation practitioners believe that because population-level conservation translocations have been successful that mitigation translocation can be satisfactorily applied to a wide variety of human-wildlife conflict situations. We reviewed mitigation translocations of reptiles, including our own work with 3 long-lived species (Gila monsters [Heloderma suspectum], Sonoran desert tortoises [Gopherus morafkai], and western diamond-backed rattlesnakes [Crotalus atrox]). Overall, mitigation translocation had a low success rate when judged either by effects on individuals (in all studies reviewed they exhibited increased movement or increased mortality) or by the success of the resolution of the human-animal conflict (translocated individuals often returned to the capture site). Careful planning and identification of knowledge gaps are critical to increasing success rates in mitigation translocations in the face of increasing pressure to find solutions for species threatened by diverse anthropogenic factors, including climate change and exurban and energy development. PMID:25040040

  1. Neutral maltase: the first human B-cell enzymatic marker reflecting terminal differentiation of mature B cells into plasma cells.

    PubMed

    Philip, P J; Giudicelli, J; Delqué, P; Cassuto, J P; Sudaka, P; Ayraud, N

    1983-08-01

    Neutral maltase activity (alpha-D-glucoside glucohydrolase; EC: 3.2.1.20) was measured in B and T lymphocytes from peripheral blood of normal subjects and patients suffering from chronic or acute lymphoid leukemias. Neutral maltase activity is undetectable in T cells from normal subjects as well as in patients with chronic or acute T-lymphoid leukemias. Conversely, whereas this enzyme activity is always undetectable in chronic or acute B-lymphoid leukemia, neutral maltase activity is expressed in mature B cells from normal subjects. The detection of higher neutral maltase activity in plasma cells from myelomas than in normal B cells supports the concept that the expression of neutral maltase activity is related to the stages of differentiation and maturation reached by lymphocytes of the B-cell lineage. Neutral maltase therefore appears as the first B-cell enzymatic marker described that is expressed in the course of terminal differentiation of mature B cells into plasma cells. PMID:6347275

  2. High-efficiency Generation of Multiple Short Noncoding RNA in B-cells and B-cell-derived Extracellular Vesicles.

    PubMed

    Almanza, Gonzalo; Zanetti, Maurizio

    2015-01-01

    Short noncoding (snc)RNAs are important new players in the landscape of biologics with therapeutic potential. Recently, we reported on a new method for the synthesis and delivery of snc RNA in B-cells transfected with plasmid DNA. Here using the same approach, we demonstrate that B-cells can be programmed for the enforced biogenesis and synchronous release of multiple sncRNAs. Our data show that this goal is feasible and that multiple sncRNA are released in the extracellular compartment in amounts comparable to those from B-cells programmed to express and secrete one scnRNA only. Furthermore, we found that the cargo of extracellular vescicles (EVs) isolated from programmed B-cells is remarkably enriched for multiple sncRNA. On average, we found that the content of multiple sncRNAs in EVs is 3.6 copynumber/EV. Collectively, we demonstrate that B-cells can be easily programmed toward the synthesis and release of multiple sncRNAs, including sncRNA-laden EVs, efficiently and specifically. PMID:26670278

  3. Regulation of AID, the B-cell genome mutator.

    PubMed

    Keim, Celia; Kazadi, David; Rothschild, Gerson; Basu, Uttiya

    2013-01-01

    The mechanisms by which B cells somatically engineer their genomes to generate the vast diversity of antibodies required to challenge the nearly infinite number of antigens that immune systems encounter are of tremendous clinical and academic interest. The DNA cytidine deaminase activation-induced deaminase (AID) catalyzes two of these mechanisms: class switch recombination (CSR) and somatic hypermutation (SHM). Recent discoveries indicate a significant promiscuous targeting of this B-cell mutator enzyme genome-wide. Here we discuss the various regulatory elements that control AID activity and prevent AID from inducing genomic instability and thereby initiating oncogenesis. PMID:23307864

  4. Heterogeneity in the differentiation and function of memory B cells.

    PubMed

    Taylor, Justin J; Jenkins, Marc K; Pape, Kathryn A

    2012-12-01

    Vaccines that induce neutralizing antibodies have led to the eradication of small pox and have severely reduced the prevalence of many other infections. However, even the most successful vaccines do not induce protective antibodies in all individuals, and can fail to induce lifelong immunity. A key to remedying these shortcomings may lie in a better understanding of long-lived memory B cells. Recent studies have revealed novel insights into the differentiation and function of these cells, and have shown that the memory B cell pool is much more heterogeneous than previously appreciated. PMID:22920843

  5. Molecular cloning, expression and bioactivity of B cell activating factor (BAFF) in African ostrich.

    PubMed

    Yang, Keli; Xiao, Ke; Huang, Haibo; Lu, Shun; Zhong, Juming; Ansari, Abdur Rahman; Khaliq, Haseeb; Song, Hui; Liu, Huazhen; Peng, Kemei

    2015-09-01

    B cell activating factor (BAFF), which belongs to the tumor necrosis factor (TNF) family, is testified to play a critical role in B cell survival, proliferation, maturation and immunoglobulin secretion. In the present study, the cDNA of open reading frame (ORF) in African ostrich (Struthio camelus) BAFF (designated OsBAFF) was cloned by reverse transcription-PCR (RT-PCR). The OsBAFF gene encodes a 288-amino acid protein containing a predicted transmembrane domain and a putative furin protease cleavage site like BAFFs from chicken (cBAFF), quail (qBAFF), duck (dBAFF), goose (gBAFF) and dove (doBAFF). RT-PCR analysis showed that the OsBAFF gene is strongly expressed in the bursa of Fabricius, thymus, spleen, and bone marrow. The soluble OsBAFF had been cloned into pET28a. SDS-PAGE and Western blotting analysis confirmed that the soluble fusion protein His-OsBAFF was efficiently expressed in Escherichia coli Rosset (DE3). In vitro, purified OsBAFF was not only able to promote the survival of African ostrich bursal lymphocytes, but also able to co-stimulate proliferation of mouse splenic B cells. The expression of OsBAFF in lymphocyte cells was higher than the control after LPS stimulation. These findings indicated that OsBAFF plays an important role in survival and proliferation of African ostrich bursal lymphocytes, which may provide valuable information for research into the immune system of African ostrich and OsBAFF may serve as a potential immunologic factor for enhancing immunological efficacy in African ostrich and any other birds. PMID:26256697

  6. Control of Viremia Enables Acquisition of Resting Memory B Cells with Age and Normalization of Activated B Cell Phenotypes in HIV-Infected Children.

    PubMed

    Muema, Daniel M; Macharia, Gladys N; Hassan, Amin S; Mwaringa, Shalton M; Fegan, Greg W; Berkley, James A; Nduati, Eunice W; Urban, Britta C

    2015-08-01

    HIV affects the function of all lymphocyte populations, including B cells. Phenotypic and functional defects of B cells in HIV-infected adults have been well characterized, but defects in children have not been studied to the same extent. We determined the proportion of B cell subsets and frequencies of Ag-specific memory B cells in peripheral blood from HIV-infected children and healthy controls, using flow cytometry and B cell ELISPOT, respectively. In addition, we measured the quantities and avidities of plasma Abs against various Ags by ELISA. We also determined plasma levels of BAFF and expression of BAFF receptors on B cells. Children with high HIV viremia had increased proportions of activated mature B cells, tissue-like memory B cells and plasmablasts, and low proportions of naive B cells when compared with community controls and children with low HIV viremia, similar to adults infected with HIV. HIV-infected groups had lower proportions of resting memory B cells than did community controls. Notably, high HIV viremia prevented the age-dependent accumulation of class-switched resting memory B cells. HIV-infected children, regardless of the level of viremia, showed lower quantities and avidities of IgG and lower frequencies of memory B cells against Expanded Program on Immunization vaccines. The HIV-infected children had an altered BAFF profile that could have affected their B cell compartment. Therefore, B cell defects in HIV-infected children are similar to those seen in HIV-infected adults. However, control of HIV viremia is associated with normalization of activated B cell subsets and allows age-dependent accumulation of resting memory B cells. PMID:26116511

  7. Control of Viremia Enables Acquisition of Resting Memory B Cells with Age and Normalization of Activated B Cell Phenotypes in HIV-Infected Children

    PubMed Central

    Muema, Daniel M.; Macharia, Gladys N.; Hassan, Amin S.; Mwaringa, Shalton M.; Fegan, Greg W.; Berkley, James A.; Urban, Britta C.

    2015-01-01

    HIV affects the function of all lymphocyte populations, including B cells. Phenotypic and functional defects of B cells in HIV-infected adults have been well characterized, but defects in children have not been studied to the same extent. We determined the proportion of B cell subsets and frequencies of Ag-specific memory B cells in peripheral blood from HIV-infected children and healthy controls, using flow cytometry and B cell ELISPOT, respectively. In addition, we measured the quantities and avidities of plasma Abs against various Ags by ELISA. We also determined plasma levels of BAFF and expression of BAFF receptors on B cells. Children with high HIV viremia had increased proportions of activated mature B cells, tissue-like memory B cells and plasmablasts, and low proportions of naive B cells when compared with community controls and children with low HIV viremia, similar to adults infected with HIV. HIV-infected groups had lower proportions of resting memory B cells than did community controls. Notably, high HIV viremia prevented the age-dependent accumulation of class-switched resting memory B cells. HIV-infected children, regardless of the level of viremia, showed lower quantities and avidities of IgG and lower frequencies of memory B cells against Expanded Program on Immunization vaccines. The HIV-infected children had an altered BAFF profile that could have affected their B cell compartment. Therefore, B cell defects in HIV-infected children are similar to those seen in HIV-infected adults. However, control of HIV viremia is associated with normalization of activated B cell subsets and allows age-dependent accumulation of resting memory B cells. PMID:26116511

  8. Identification of renin progenitors in the mouse bone marrow that give rise to B-cell leukaemia

    PubMed Central

    Belyea, Brian C.; Xu, Fang; Pentz, Ellen S.; Medrano, Silvia; Li, Minghong; Hu, Yan; Turner, Stephen; Legallo, Robin; Jones, Craig A.; Tario, Joseph D.; Liang, Ping; Gross, Kenneth W.; Sequeira-Lopez, Maria Luisa S.; Gomez, R. Ariel

    2014-01-01

    The cell of origin and triggering events for leukaemia are mostly unknown. Here we show that the bone marrow contains a progenitor that expresses renin throughout development and possesses a B-lymphocyte pedigree. This cell requires RBP-J to differentiate. Deletion of RBP-J in these renin-expressing progenitors enriches the precursor B-cell gene programme and constrains lymphocyte differentiation, facilitated by H3K4me3 activating marks in genes that control the pre-B stage. Mutant cells undergo neoplastic transformation, and mice develop a highly penetrant B-cell leukaemia with multi-organ infiltration and early death. These renin-expressing cells appear uniquely vulnerable as other conditional models of RBP-J deletion do not result in leukaemia. The discovery of these unique renin progenitors in the bone marrow and the model of leukaemia described herein may enhance our understanding of normal and neoplastic haematopoiesis. PMID:24549417

  9. Persistence and selection of an expanded B-cell clone in the setting of rituximab therapy for Sjögren’s syndrome

    PubMed Central

    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 expanded clone may provide a novel means of measuring the chronicity and selection of expanded B-cell populations in humans. PMID:24517398

  10. Translocation time of periodically forced polymer chains

    E-print Network

    Alessandro Fiasconaro; Juan José Mazo; Fernando Falo

    2010-09-09

    We show the presence of both a minimum and clear oscillations in the frequency dependence of the translocation time of a polymer described as a unidimensional Rouse chain driven by a spatially localized oscillating linear potential. The observed oscillations of the mean translocation time arise from the synchronization between the very mean translocation time and the period of the external force. We have checked the robustness of the frequency value for the minimum translocation time by changing the damping parameter, finding a very simple relationship between this frequency and the correspondent translocation time. The translocation time as a function of the polymer length has been also evaluated, finding a precise $L^2$ scaling. Furthermore, the role played by the thermal fluctuations described as a Gaussian uncorrelated noise has been also investigated, and the analogies with the resonant activation phenomenon are commented.

  11. An interaction between the SRP receptor and the translocon is critical during cotranslational protein translocation

    PubMed Central

    Jiang, Ying; Cheng, Zhiliang; Mandon, Elisabet C.; Gilmore, Reid

    2008-01-01

    The signal recognition particle (SRP)–dependent targeting pathway facilitates rapid, efficient delivery of the ribosome–nascent chain complex (RNC) to the protein translocation channel. We test whether the SRP receptor (SR) locates a vacant protein translocation channel by interacting with the yeast Sec61 and Ssh1 translocons. Surprisingly, the slow growth and cotranslational translocation defects caused by deletion of the transmembrane (TM) span of yeast SR? (SR?-?TM) are exaggerated when the SSH1 gene is disrupted. Disruption of the SBH2 gene, which encodes the ? subunit of the Ssh1p complex, likewise causes a growth defect when combined with SR?-?TM. Cotranslational translocation defects in the ssh1?SR?-?TM mutant are explained by slow and inefficient in vivo gating of translocons by RNCs. A critical function for translocation channel ? subunits in the SR–channel interaction is supported by the observation that simultaneous deletion of Sbh1p and Sbh2p causes a defect in the cotranslational targeting pathway that is similar to the translocation defect caused by deletion of either subunit of the SR. PMID:18347066

  12. Spontaneous T-cell-rich B-cell lymphoma in a cynomolgus monkey (Macaca fascicularis).

    PubMed

    Michishita, Masaki; Nakamura, Shin-ichiro; Sakakibara, Ippei; Ono, Fumiko; Fujimoto, Kouji; Kamiya, Kazusaku; Ishii, Yoshiyuki; Hayashi, Kazuhiko; Yoshikawa, Yasuhiro; Takahashi, Kimimasa

    2003-07-01

    A spontaneous T-cell-rich B-cell lymphoma (TCRBCL) occurred as a subcutaneous mass in the buccal region and enlarged submandibular lymph node in a 6-year-old female cynomolgus monkey (Macaca fascicularis). The constituent cells were examined by histology, immunohistochemistry and the double labeled-immunofluorescence method (dl-IF). Further, in situ hybridization (ISH) was employed to detect the gene expression of Epstein Barr virus (EBV). Histologically, the mass was comprised mainly of neoplastic large lymphoid cells and reactive small mononuclear cells. Immunohistochemically, the neoplastic large lymphoid cells were positive for CD20, CD79 alpha, MHC class II, and either IgG, IgM, or IgA. Polyclonal Ig production by the neoplastic large lymphoid cells was demonstrated by dl-IF, although IgG-positive ones predominated in number. On the other hand, most of the small mononuclear cells were positive for CD3 and were regarded as reactive T lymphocytes, while the remaining cells appeared to be histocytes or reactive B-cells. Transcripts of EBV gene were not demonstrated in these neoplastic or reactive cells by ISH. This is the first reported case of spontaneous TCRBCL in the cynomolgus monkey. PMID:14562611

  13. MLL2 protein is a prognostic marker for gastrointestinal diffuse large B-cell lymphoma

    PubMed Central

    Ye, Haige; Lu, Lu; Ge, Bei; Gao, Shenmeng; Ma, Yongyong; Liang, Bin; Yu, Kang; Yang, Kaiyan

    2015-01-01

    Mixed linage leukemia gene 2 (MLL2) is identified as a novel mutation gene in diffuse large B cell lymphoma (DLBCL). However, the significance of MLL2 protein expression for the prognosis of DLBCL is unclear. In this study, we detected MLL2 protein expression in primary gastrointestinal diffuse large B cell lymphoma (PGI-DLBCL) samples by using tissue microarray immunohistochemistry, and analyzed the correlation between MLL2 protein expression and tumor proliferation activity. In addition, we investigated clinical significance of MLL2 protein expression for PGI-DLBCL prognosis. We found that there was significant difference in MLL2 protein expression between PGI-DLBCL and reactive hyperplasia of lymph node. High expression of MLL2 protein indicated higher clinical stage. In older patients (>60 years) with PGI-DLBCL, MLL2 protein expression was positively correlated with Ki-67 expression and negatively correlated with patient survival. Our data suggest that MLL2 protein is overexpressed in PGI-DLBCL and appears as a prognostic factor for patients of PGI-DLBCL, especially for those older than 60 years old. PMID:26722499

  14. Primary pleural precursor B-Cell lymphoblastic lymphoma

    PubMed Central

    Williams, Mark S; Cheesman, Edmund; Kaleem, Musa; Wynn, Robert

    2015-01-01

    Key Clinical Message Intrathoracic lymphoblastic lymphoma (LBL) is classically of T-cell lineage, but these cases of pleural B-cell LBL suggest that this is not always the case. Despite the clinical challenges involved every attempt should be made to secure a biopsy and histological diagnosis, as we move into an era of lineage-directed therapies. PMID:26509024

  15. The Memory Function of the B Cell Antigen Receptor.

    PubMed

    Wienands, Jürgen; Engels, Niklas

    2016-01-01

    Activated B lymphocytes preserve their antigen experience by differentiating into long-lived pools of antibody-secreting plasma cells or various types of memory B cells (MBCs). The former population constantly produces serum immunoglobulins with sufficient specificity and affinity to thwart infections with recurrent pathogens. By contrast, memory B cell populations retain their antigen receptors on the cell surface and hence need pathogen-induced differentiation steps before they can actively contribute to host defense. The terminal differentiation of MBCs into antibody-secreting plasma cells is hallmarked by the absence of the lag phase characteristic for primary antibody responses. Moreover, secondary antibody responses are predominantly driven by MBCs that bear an antigen receptor of the IgG class on their surface although IgM-positive memory populations exist as well. These fundamental principles of B cell memory were enigmatic for decades. Only recently, we have begun to understand the underlying mechanisms. This review summarizes our current understanding of how different subpopulations of MBCs are generated during primary immune responses and how their functional heterogeneity on antigen recall is controlled by different signaling capabilities of B cell antigen receptor (BCR) isotypes and by the nature of the antigen. PMID:26362935

  16. An eruption of European B-cell biology

    PubMed Central

    Cancro, Michael P.

    2010-01-01

    Volcanic ash clouds disrupted the 2010 ESF/EMBO meeting on B cells and protection. Nevertheless, the delegates who did make it to Catalonia put together their own programme of talks covering a range of themes from mutualism to epigenetics. PMID:20725089

  17. MUC-1 mucin protein expression in B-cell lymphomas.

    PubMed

    Teruya-Feldstein, Julie; Donnelly, Gerard B; Goy, Andre; Hegde, Abhijith; Nanjangud, Gouri; Qin, Jing; Thaler, Howard; Gilles, Frederic; Dyomin, Vadim G; Lloyd, Kenneth O; Zelenetz, Andrew D; Houldsworth, Jane; Chaganti, R S K

    2003-03-01

    We have recently shown that MUC1, mapped to the chromosomal band 1q21, is rearranged or amplified in 15% of B-cell lymphomas and that rearrangement led to over-expression of MUC-1 mucin in a case of diffuse large B-cell lymphoma (DLBCL). To determine the incidence of MUC-1 mucin expression and its clinical significance in B-cell lymphomas, we investigated a panel of 113 cases by immunohistochemistry (IHC). MUC-1 mucin expression was detected in the majority of cases (92.9%), with moderate to high levels noted in 50.4% of all histologic subsets comprising DLBCL (82 cases), follicular lymphoma (FL) (15 cases), FL with transformation to DLBCL (4 cases), and other B-cell lymphomas (12 cases). No statistically significant correlation was found between MUC-1 mucin expression and MUC1 genomic status (amplification/rearrangement) evaluated by Southern blot analysis, and 1q21 abnormality by karyotypic analysis. For all cases, MUC-1 mucin expression correlated with a previous history of lymphoma (p=0.003). PMID:12610353

  18. Manipulation of B-cell responses with histone deacetylase inhibitors.

    PubMed

    Waibel, Michaela; Christiansen, Ailsa J; Hibbs, Margaret L; Shortt, Jake; Jones, Sarah A; Simpson, Ian; Light, Amanda; O'Donnell, Kristy; Morand, Eric F; Tarlinton, David M; Johnstone, Ricky W; Hawkins, Edwin D

    2015-01-01

    Histone deacetylase inhibitors (HDACi) are approved for treating certain haematological malignancies, however, recent evidence also illustrates they are modulators of the immune system. In experimental models, HDACi are particularly potent against malignancies originating from the B-lymphocyte lineage. Here we examine the ability of this class of compounds to modify both protective and autoimmune antibody responses. In vitro, HDACi affect B-cell proliferation, survival and differentiation in an HDAC-class-dependent manner. Strikingly, treatment of lupus-prone Mrl/lpr mice with the HDACi panobinostat significantly reduces autoreactive plasma-cell numbers, autoantibodies and nephritis, while other immune parameters remain largely unaffected. Immunized control mice treated with panobinostat or the clinically approved HDACi vorinostat have significantly impaired primary antibody responses, but these treatments surprisingly spare circulating memory B cells. These studies indicate that panobinostat is a potential therapy for B-cell-driven autoimmune conditions and HDACi do not induce major long-term detrimental effects on B-cell memory. PMID:25913720

  19. The Lymph Node B Cell Immune Response: Dynamic

    E-print Network

    Harel, David

    responses. By Naamah Swerdlin, Irun R. Cohen, and David Harel ABSTRACT | Lymph nodes are organs in whichINVITED P A P E R The Lymph Node B Cell Immune Response: Dynamic Analysis In-Silico A computer, the lymph node (LN) has to orchestrate the meeting and interactions between the antigen and various cell

  20. Cisgenesis strongly improves introgression breeding and induced translocation breeding of plants.

    PubMed

    Jacobsen, Evert; Schouten, Henk J

    2007-05-01

    There are two ways for genetic improvement in classical plant breeding: crossing and mutation. Plant varieties can also be improved through genetic modification; however, the present GMO regulations are based on risk assessments with the transgenes coming from non-crossable species. Nowadays, DNA sequence information of crop plants facilitates the isolation of cisgenes, which are genes from crop plants themselves or from crossable species. The increasing number of these isolated genes, and the development of transformation protocols that do not leave marker genes behind, provide an opportunity to improve plant breeding while remaining within the gene pool of the classical breeder. Compared with induced translocation and introgression breeding, cisgenesis is an improvement for gene transfer from crossable plants: it is a one-step gene transfer without linkage drag of other genes, whereas induced translocation and introgression breeding are multiple step gene transfer methods with linkage drag. The similarity of the genes used in cisgenesis compared with classical breeding is a compelling argument to treat cisgenic plants as classically bred plants. In the case of the classical breeding method induced translocation breeding, the insertion site of the genes is a priori unknown, as it is in cisgenesis. This provides another argument to treat cisgenic plants as classically bred plants, by exempting cisgenesis of plants from the GMO legislations. PMID:17383037

  1. Expansion of Activated Peripheral Blood Memory B Cells in Rheumatoid Arthritis, Impact of B Cell Depletion Therapy, and Biomarkers of Response

    PubMed Central

    Adlowitz, Diana G.; Barnard, Jennifer; Biear, Jamie N.; Cistrone, Christopher; Owen, Teresa; Wang, Wensheng; Palanichamy, Arumugam; Ezealah, Ezinma; Campbell, Debbie; Wei, Chungwen; Looney, R. John; Sanz, Inaki; Anolik, Jennifer H.

    2015-01-01

    Although B cell depletion therapy (BCDT) is effective in a subset of rheumatoid arthritis (RA) patients, both mechanisms and biomarkers of response are poorly defined. Here we characterized abnormalities in B cell populations in RA and the impact of BCDT in order to elucidate B cell roles in the disease and response biomarkers. In active RA patients both CD27+IgD- switched memory (SM) and CD27-IgD- double negative memory (DN) peripheral blood B cells contained significantly higher fractions of CD95+ and CD21- activated cells compared to healthy controls. After BCD the predominant B cell populations were memory, and residual memory B cells displayed a high fraction of CD21- and CD95+ compared to pre-depletion indicating some resistance of these activated populations to anti-CD20. The residual memory populations also expressed more Ki-67 compared to pre-treatment, suggesting homeostatic proliferation in the B cell depleted state. Biomarkers of clinical response included lower CD95+ activated memory B cells at depletion time points and a higher ratio of transitional B cells to memory at reconstitution. B cell function in terms of cytokine secretion was dependent on B cell subset and changed with BCD. Thus, SM B cells produced pro-inflammatory (TNF) over regulatory (IL10) cytokines as compared to naïve/transitional. Notably, B cell TNF production decreased after BCDT and reconstitution compared to untreated RA. Our results support the hypothesis that the clinical and immunological outcome of BCDT depends on the relative balance of protective and pathogenic B cell subsets established after B cell depletion and repopulation. PMID:26047509

  2. Next Generation Sequencing Reveals Skewing of the T and B Cell Receptor Repertoires in Patients with Wiskott–Aldrich Syndrome

    PubMed Central

    O’Connell, Amy E.; Volpi, Stefano; Dobbs, Kerry; Fiorini, Claudia; Tsitsikov, Erdyni; de Boer, Helen; Barlan, Isil B.; Despotovic, Jenny M.; Espinosa-Rosales, Francisco J.; Hanson, I. Celine; Kanariou, Maria G.; Martínez-Beckerat, Roxana; Mayorga-Sirera, Alvaro; Mejia-Carvajal, Carmen; Radwan, Nesrine; Weiss, Aaron R.; Pai, Sung-Yun; Lee, Yu Nee; Notarangelo, Luigi D.

    2014-01-01

    The Wiskott–Aldrich syndrome (WAS) is due to mutations of the WAS gene encoding for the cytoskeletal WAS protein, leading to abnormal downstream signaling from the T cell and B cell antigen receptors (TCR and BCR). We hypothesized that the impaired signaling through the TCR and BCR in WAS would subsequently lead to aberrations in the immune repertoire of WAS patients. Using next generation sequencing (NGS), the T cell receptor ? and B cell immunoglobulin heavy chain (IGH) repertoires of eight patients with WAS and six controls were sequenced. Clonal expansions were identified within memory CD4+ cells as well as in total, naïve and memory CD8+ cells from WAS patients. In the B cell compartment, WAS patient IGH repertoires were also clonally expanded and showed skewed usage of IGHV and IGHJ genes, and increased usage of IGHG constant genes, compared with controls. To our knowledge, this is the first study that demonstrates significant abnormalities of the immune repertoire in WAS patients using NGS. PMID:25101082

  3. Reversible disruption of BCL6 repression complexes by CD40 signaling in normal and malignant B cells.

    PubMed

    Polo, Jose M; Ci, Weimin; Licht, Jonathan D; Melnick, Ari

    2008-08-01

    Germinal center (GC) B cells undergo somatic hypermutation, class switch recombination, and rapid clonal expansion to produce high-affinity antibodies. The BCL6 transcriptional repressor facilitates this phenotype because it can repress DNA damage checkpoint genes. GC B and T cells can make transient direct physical contact; T cells were observed to be associated with dead B-cell fragments. We thus hypothesized that one function of CD40 signaling from T cells within this timeframe could be to modulate BCL6 activity. CD40 signaling rapidly disrupts the ability of BCL6 to recruit the SMRT corepressor complex by excluding it from the nucleus, leading to histone acetylation, RNA polymerase II processivity, and activation of BCL6 target genes, such as CD23b, ATR, and TP53. Washout of CD40 to emulate transient T-cell contact permitted BCL6 target gene mRNA levels to return to their repressed levels, demonstrating that this is a reversible process, which could allow centroblasts that pass quality control to either continue proliferation or undergo terminal differentiation. These data suggest that transient CD40 signaling in the GC might allow T cells to weed out heavily damaged centroblasts while at the same time promoting survival of intact B cells, which could undergo differentiation or additional rounds of proliferation. PMID:18487509

  4. Dual mechanisms by which miR-125b represses IRF4 to induce myeloid and B-cell leukemias.

    PubMed

    So, Alex Yick-Lun; Sookram, Reeshelle; Chaudhuri, Aadel A; Minisandram, Aarathi; Cheng, David; Xie, Catherine; Lim, Ee Lyn; Flores, Yvette Garcia; Jiang, Shuai; Kim, Jocelyn Tammy; Keown, Christopher; Ramakrishnan, Parameswaran; Baltimore, David

    2014-08-28

    The oncomir microRNA-125b (miR-125b) is upregulated in a variety of human neoplastic blood disorders and constitutive upregulation of miR-125b in mice can promote myeloid and B-cell leukemia. We found that miR-125b promotes myeloid and B-cell neoplasm by inducing tumorigenesis in hematopoietic progenitor cells. Our study demonstrates that miR-125b induces myeloid leukemia by enhancing myeloid progenitor output from stem cells as well as inducing immortality, self-renewal, and tumorigenesis in myeloid progenitors. Through functional and genetic analyses, we demonstrated that miR-125b induces myeloid and B-cell leukemia by inhibiting interferon regulatory factor 4 (IRF4) but through distinct mechanisms; it induces myeloid leukemia through repressing IRF4 at the messenger RNA (mRNA) level without altering the genomic DNA and induces B-cell leukemia via genetic deletion of the gene encoding IRF4. PMID:25006123

  5. New roles for DNA cytosine modification, eRNA, anchors, and superanchors in developing B cell progenitors.

    PubMed

    Benner, Christopher; Isoda, Takeshi; Murre, Cornelis

    2015-10-13

    B-cell fate is orchestrated by a series of well-characterized developmental regulators. Here, we found that the onset of B-cell development was accompanied by large-scale changes in DNA cytosine modifications associated with promoters, enhancers, and anchors. These changes were tightly linked to alterations in transcription factor occupancy and nascent RNA (eRNA) transcription. We found that the prepro-B to the pro-B-cell transition was associated with a global exchange of DNA cytosine modifications for polycomb-mediated repression at CpG islands. Hypomethylated regions were found exclusively in the active/permissive compartment of the nucleus and were predominantly associated with regulatory elements or anchors that orchestrate the folding patterns of the genome. We identified superanchors, characterized by clusters of hypomethylated CCCTC-binding factor (CTCF)-bound elements, which were predominantly located at boundaries that define topological associated domains. A particularly prominent hypomethylated superanchor was positioned down-stream of the Ig heavy chain (Igh) locus. Analysis of global formaldehyde-cross-linking studies indicated that the Igh locus superanchor interacts with the VH region repertoire across vast genomic distances. We propose that the Igh locus superanchor sequesters the VH and DHJH regions into a spatial confined geometric environment to promote rapid first-passage times. Collectively, these studies demonstrate how, in developing B cells, DNA cytosine modifications associated with regulatory and architectural elements affect patterns of gene expression, folding patterns of the genome, and antigen receptor assembly. PMID:26417104

  6. Characterization of a 3;6 Translocation Associated with Renal Cell Carcinoma

    PubMed Central

    Foster, Rebecca E.; Abdulrahman, Mahera; Morris, Mark R.; Prigmore, Elena; Gribble, Susan; Ng, Beeling; Gentle, Dean; Ready, Steven; Weston, Phil M. T.; Wiesener, Michael S.; Kishida, Takeshi; Yao, Masahiro; Davison, Val; Barbero, Jose Luis; Chu, Carol; Carter, Nigel P.; Latif, Farida; Maher, Eamonn R.

    2009-01-01

    The most frequent cause of familial clear cell renal cell carcinoma (RCC) is von Hippel–Lindau disease and the VHL tumor suppressor gene (TSG) is inactivated in most sporadic clear cell RCC. Although there is relatively little information on the mechanisms of tumorigenesis of clear cell RCC without VHL inactivation, a subset of familial cases harbors a balanced constitutional chromosome 3 translocation. To date nine different chromosome 3 translocations have been associated with familial or multicentric clear cell RCC; and in three cases chromosome 6 was also involved. To identify candidate genes for renal tumorigenesis we characterized a constitutional translocation, t(3;6)(q22;q16.1) associated with multicentric RCC without evidence of VHL target gene dysregulation. Analysis of breakpoint sequences revealed a 1.3-kb deletion on chromosome 6 within the intron of a 2 exon predicted gene (NT_007299.434). However, RT-PCR analysis failed to detect the expression of this gene in lymphoblast, fibroblast, or kidney tumor cell lines. No known genes were disrupted by the translocation breakpoints but several candidate TSGs (e.g., EPHB1, EPHA7, PPP2R3A RNF184, and STAG1) map within close proximity to the breakpoints. PMID:17205537

  7. Molecular signals regulating translocation and toxicity of graphene oxide in the nematode Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Wu, Qiuli; Zhao, Yunli; Li, Yiping; Wang, Dayong

    2014-09-01

    Both in vitro and in vivo studies have demonstrated the toxic effects of graphene oxide (GO). However, the molecular basis for the translocation and toxicity of GO is still largely unclear. In the present study, we employed an in vivo Caenorhabditis elegans assay system to identify molecular signals involved in the control of the translocation and toxicity of GO. We identified 7 genes whose mutations altered both the translocation and toxicity of GO. Mutations of the hsp-16.48, gas-1, sod-2, sod-3, and aak-2 genes caused greater GO translocation into the body and toxic effects on both primary and secondary targeted organs compared with wild type; however, mutations of the isp-1 and clk-1 genes resulted in significantly decreased GO translocation into the body and toxicity on both primary and secondary targeted organs compared with wild-type. Moreover, mutations of the hsp-16.48, gas-1, sod-2, sod-3, and aak-2 genes caused increased intestinal permeability and prolonged mean defecation cycle length in GO-exposed nematodes, whereas mutations of the isp-1 and clk-1 genes resulted in decreased intestinal permeability in GO-exposed nematodes. Therefore, for the underlying mechanism, we hypothesize that both intestinal permeability and defecation behavior may have crucial roles in controlling the functions of the identified molecular signals. The molecular signals may further contribute to the control of transgenerational toxic effects of GO. Our results provide an important insight into understanding the molecular basis for the in vivo translocation and toxicity of GO.Both in vitro and in vivo studies have demonstrated the toxic effects of graphene oxide (GO). However, the molecular basis for the translocation and toxicity of GO is still largely unclear. In the present study, we employed an in vivo Caenorhabditis elegans assay system to identify molecular signals involved in the control of the translocation and toxicity of GO. We identified 7 genes whose mutations altered both the translocation and toxicity of GO. Mutations of the hsp-16.48, gas-1, sod-2, sod-3, and aak-2 genes caused greater GO translocation into the body and toxic effects on both primary and secondary targeted organs compared with wild type; however, mutations of the isp-1 and clk-1 genes resulted in significantly decreased GO translocation into the body and toxicity on both primary and secondary targeted organs compared with wild-type. Moreover, mutations of the hsp-16.48, gas-1, sod-2, sod-3, and aak-2 genes caused increased intestinal permeability and prolonged mean defecation cycle length in GO-exposed nematodes, whereas mutations of the isp-1 and clk-1 genes resulted in decreased intestinal permeability in GO-exposed nematodes. Therefore, for the underlying mechanism, we hypothesize that both intestinal permeability and defecation behavior may have crucial roles in controlling the functions of the identified molecular signals. The molecular signals may further contribute to the control of transgenerational toxic effects of GO. Our results provide an important insight into understanding the molecular basis for the in vivo translocation and toxicity of GO. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02688h

  8. Translocation (Y;12) in lipoma.

    PubMed

    Liang, Cher-Wei; Mariño-Enríquez, Adrian; Johannessen, Catherine; Hornick, Jason L; Dal Cin, Paola

    2011-01-01

    Lipomas are the most common benign mesenchymal neoplasm in adults, and have been extensively characterized at the cytogenetic level. Chromosomal aberrations have been observed in the majority of lipomas, two-thirds of which involve chromosomal region 12q14.3. To date, structural rearrangements have been reported affecting every chromosome except chromosome Y. Here we report a case of a lipoma that shows a novel apparently balanced translocation involving chromosomes Y and 12. Fluorescence in situ hybridization using a break-apart HMGA2 in-house probe set detected a single signal on the normal chromosome 12 but not on either the derivative chromosome Y or 12, indicating a cryptic loss of 12q14.3, where HMGA2 is mapped. Immunohistochemical studies, however, revealed overexpression of HMGA2 with nuclear expression in the majority of tumor cells, whereas MDM2 and CDK4 were negative. The overexpression of HMGA2 may be caused by a cryptic chromosomal aberration affecting either the cytogenetically unaltered HMGA2 allele or HMGA2 regulators elsewhere. The current case broadens our knowledge about the translocation partners of HMGA2 in lipomas and highlights the biological complexity in regulating HMGA2 expression. PMID:21356192

  9. Dynamin-related protein Drp1 is required for Bax translocation to mitochondria in response to irradiation-induced apoptosis

    PubMed Central

    Wang, Ping; Wang, Peiguo; Liu, Becky; Zhao, Jing; Pang, Qingsong; Agrawal, Samir G.; Jia, Li; Liu, Feng-Ting

    2015-01-01

    Translocation of the pro-apoptotic protein Bax from the cytosol to the mitochondria is a crucial step in DNA damage-mediated apoptosis, and is also found to be involved in mitochondrial fragmentation. Irradiation-induced cytochrome c release and apoptosis was associated with Bax activation, but not mitochondrial fragmentation. Both Bax and Drp1 translocated from the cytosol to the mitochondria in response to irradiation. However, Drp1 mitochondrial translocation and oligomerization did not require Bax, and failed to induce apoptosis in Bax deficient diffuse large B-cell lymphoma (DLBCL) cells. Using fluorescent microscopy and the intensity correlation analysis, we demonstrated that Bax and Drp1 were colocalized and the levels of colocalization were increased by UV irradiation. Using co-immuno-precipitation, we confirmed that Bax and Drp1 were binding partners. Irradiation induced a time-associated increase in the interaction between active Bax and Drp1. Knocking down Drp1 using siRNA blocked UV irradiation-mediated Bax mitochondrial translocation. In conclusion, our findings demonstrate for the first time, that Drp1 is required for Bax mitochondrial translocation, but Drp1-induced mitochondrial fragmentation alone is not sufficient to induce apoptosis in DLBCL cells. PMID:26093086

  10. High prevalence of immunoglobulin light chain gene aberrations as revealed by FISH in multiple myeloma and MGUS.

    PubMed

    Türkmen, Seval; Binder, Anastasia; Gerlach, Antje; Niehage, Sylke; Theodora Melissari, Maria; Inandiklioglu, Nihal; Dörken, Bernd; Burmeister, Thomas

    2014-08-01

    Multiple myeloma (MM) is a malignant B-cell neoplasm characterized by an uncontrolled proliferation of aberrant plasma cells in the bone marrow. Chromosome aberrations in MM are complex and represent a hallmark of the disease, involving many chromosomes that are altered both numerically and structurally. Nearly half of the cases are nonhyperdiploid and show IGH translocations with the following partner genes: CCND1, FGFR3 and MMSET, MAF, MAFB, and CCND3. The remaining 50% are grouped into a hyperdiploid group that is characterized by multiple trisomies involving chromosomes 3, 5, 7, 9, 11, 15, 19, and 21. In this study, we analyzed the immunoglobulin light chain kappa (IGK, 2p12) and lambda (IGL, 22q11) loci in 150 cases, mostly with MM but in a few cases monoclonal gammopathy of undetermined significance (MGUS), without IGH translocations. We identified aberrations in 27% (= 40 patients) including rearrangements (12%), gains (12%), and deletions (4.6%). In 6 of 18 patients with IGK or/and IGL rearrangements, we detected a MYC rearrangement which suggests that MYC is the translocation partner in the majority of these cases. PMID:24729354

  11. Recent Selection on the Y-to-Dot Translocation in Drosophila pseudoobscura

    PubMed Central

    Larracuente, Amanda M.; Clark, Andrew G.

    2014-01-01

    The Drosophila pseudoobscura dot chromosome acquired genes from the ancestral Drosophila Y chromosome in a Y-to-dot translocation event that occurred between 12.7 and 20.8 Ma. The formerly Y-linked genes mostly retained their testis-specific expression but shrank drastically in size, mostly through intron reduction, since becoming part of the dot chromosome in this species. We investigated the impact of this translocation on the evolution of the both the Y-to-dot translocated region and the original segments of the dot chromosome in D. pseudoobscura. Our survey of polymorphism and divergence across the chromosome reveals a reduction in variation, a deletion polymorphism segregating at high frequency, and a shift in the frequency spectra, all consistent with a history of recent selective sweeps in the Y-to-dot translocated region but not on the rest of the dot chromosome. We do find evidence for recombination primarily as gene conversion on the dot chromosome; however, predicted recombination events are restricted to the part of the dot chromosome outside the translocation. It therefore appears that recombination has resulted in a degree of decoupling between the ancestral Y region and the conserved region of the dot chromosome. PMID:24390701

  12. Establishment of Murine Gammaherpesvirus Latency in B Cells Is Not a Stochastic Event

    PubMed Central

    Fontinha, Diana; Marques, Sofia; Simas, J. Pedro

    2014-01-01

    Murid ?-herpesvirus-4 (MuHV-4) promotes polyclonal B cell activation and establishes latency in memory B cells via unclear mechanisms. We aimed at exploring whether B cell receptor specificity plays a role in B cell susceptibility to viral latency and how this is related to B cell activation. We first observed that MuHV-4-specific B cells represent a minority of the latent population, and to better understand the influence of the virus on non-MuHV-4 specific B cells we used the SWHEL mouse model, which produce hen egg lysozyme (HEL)-specific B cells. By tracking HEL+ and HEL? B cells, we showed that in vivo latency was restricted to HEL? B cells while the two populations were equally sensitive to the virus in vitro. Moreover, MuHV-4 induced two waves of B cell activation. While the first wave was characterized by a general B cell activation, as shown by HEL+ and HEL? B cells expansion and upregulation of CD69 expression, the second wave was restricted to the HEL? population, which acquired germinal center (GC) and plasma cell phenotypes. Antigenic stimulation of HEL+ B cells led to the development of HEL+ GC B cells where latent infection remained undetectable, indicating that MuHV-4 does not benefit from acute B cell responses to establish latency in non-virus specific B cells but relies on other mechanisms of the humoral response. These data support a model in which the establishment of latency in B cells by ?-herpesviruses is not stochastic in terms of BCR specificity and is tightly linked to the formation of GCs. PMID:25079788

  13. The B Cell Antigen Receptor and Overexpression of MYC Can Cooperate in the Genesis of B Cell Lymphomas

    PubMed Central

    Refaeli, Yosef; Young, Ryan M; Turner, Brian C; Duda, Jennifer; Field, Kenneth A; Bishop, J. Michael

    2008-01-01

    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. PMID:18578569

  14. Haloarchaeal Protein Translocation via the Twin Arginine Translocation Pathway

    SciTech Connect

    Pohlschroder Mechthild

    2009-02-03

    Protein transport across hydrophobic membranes that partition cellular compartments is essential in all cells. The twin arginine translocation (Tat) pathway transports proteins across the prokaryotic cytoplasmic membranes. Distinct from the universally conserved Sec pathway, which secretes unfolded proteins, the Tat machinery is unique in that it secretes proteins in a folded conformation, making it an attractive pathway for the transport and secretion of heterologously expressed proteins that are Sec-incompatible. During the past 7 years, the DOE-supported project has focused on the characterization of the diversity of bacterial and archaeal Tat substrates as well as on the characterization of the Tat pathway of a model archaeon, Haloferax volcanii, a member of the haloarchaea. We have demonstrated that H. volcanii uses this pathway to transport most of its secretome.

  15. The catalytic PI3K isoforms p110gamma and p110delta contribute to B cell development and maintenance, transformation, and proliferation.

    PubMed

    Beer-Hammer, Sandra; Zebedin, Eva; von Holleben, Max; Alferink, Judith; Reis, Bernhard; Dresing, Philipp; Degrandi, Daniel; Scheu, Stefanie; Hirsch, Emilio; Sexl, Veronika; Pfeffer, Klaus; Nürnberg, Bernd; Piekorz, Roland P

    2010-06-01

    Class I PI3K-dependent signaling regulates cell proliferation, differentiation, and survival. Analysis of gene-deficient mice revealed specific roles for the hematopoietically expressed PI3K catalytic subunits, p110gamma and p110delta, in development and function of T and B lymphocytes. However, the functional redundancy between these two PI3K isoforms in the B cell lineage remains unclear. Here, we demonstrate that p110delta and p110gamma are expressed in B cells at early developmental stages. Normal B cell differentiation requires both isoforms, as p110gamma/p110delta double deficiency causes an increased percentage of CD43(hi)/B220(+)/CD19(-) cells as compared with single deficiency. Interestingly, initial transformation efficiency of B cell precursors was strongly reduced in double-deficient cells following transformation by p185 bcr-abl or v-abl oncogenes as compared with single-deficient cells. The requirement of p110gamma and p110delta in B cell development is underlined by reduced splenic B cell numbers of p110gamma/p110delta double-deficient mice and of lethally irradiated wild-type mice reconstituted with double-deficient BM. Moreover, the peripheral maintenance of p110gamma/p110delta double-deficient T and B cells was highly impaired following adoptive transfer of double-deficient splenocytes into wild-type mice. Functionally, LPS stimulation of splenocytes revealed proliferation defects resulting in decreased survival of p110gamma/p110delta double-deficient B cells, which correlated with impaired induction of D-type cyclins and Bcl-X(L). Surprisingly, this was not observed when purified B cells were analyzed, indicating a contribution of likely cell-extrinsic factor(s) to the impaired proliferation of double-deficient B cells. Thus, we provide novel evidence that p110gamma and p110delta have overlapping and cell-extrinsic roles in the development, peripheral maintenance, and function of B cells. PMID:20200404

  16. An inducible translocation strategy to rapidly

    E-print Network

    Cai, Long

    trigger rapid plasma membrane translocation and engineering different enzymatic fusion constructs in the implementation of a rapamycin-triggered heterodimerization strategy. Using molecular engineering of different processes by using a small molecule­ dependent translocation of mutant Rho GTPases to the plasma membrane

  17. Antibody detection of translocations in Ewing sarcoma

    PubMed Central

    Luo, Wen; Milash, Brett; Dalley, Brian; Smith, Richard; Zhou, Holly; Dutrow, Natalie; Cairns, Bradley R; Lessnick, Stephen L

    2012-01-01

    The detection of chromosomal translocations has important implications in the diagnosis, prognosis and treatment of patients with cancer. Current approaches to translocation detection have significant shortcomings, including limited sensitivity and/or specificity, and difficulty in application to formalin-fixed paraffin-embedded (FFPE) clinical samples. We developed a new approach called antibody detection of translocations (ADOT) that avoids the shortcomings of current techniques. ADOT combines a transcriptional microarray-based approach with a novel antibody-based detection method. ADOT allows for the accurate and sensitive identification of translocations and provides exon-level information about the fusion transcript. ADOT can detect translocations in poor-quality unprocessed total ribonucleic acid (RNA). Furthermore, the technique is readily generalizable to detect any potential fusion transcript, including previously undescribed fusions. We demonstrate the feasibility of ADOT by examples in which both known and unknown Ewing sarcoma translocations are identified from cell lines, tumour xenografts and FFPE primary tumours. These results demonstrate that ADOT may be an effective approach for translocation analysis in clinical specimens with significant RNA degradation and may offer a novel diagnostic tool for translocation-based cancers. PMID:22419563

  18. [Identification of the 1RS-7DS.7DL wheat-rye small segment translocation lines].

    PubMed

    Jun, Li; Xinguo, Zhu; Hongshen, Wan; Qin, Wang; Zongxiang, Tang; Shulan, Fu; Zujun, Yang; Manyu, Yang; Wuyun, Yang

    2015-06-01

    Rye (Secale cereale L., RR) is a valuable genetic resource for the improvement of common wheat (Triticum aestivum L., AABBDD). Transferring alien rye genes into wheat by distant hybridization and automatic chromosome doubling is an important and efficient method to boost agronomic traits, disease resistance and widening the gene pool in wheat. In this study, an octoploid triticale CD-13 (AABBDDRR) was obtained via automatic chromosome doubling by crossing landrace Penganbaimaizi (T. aestivum L., AABBDD) and rye "Qinling rye" (S. cereale cv. Qinling, RR). GISH and FISH analyses indicated that CD-13 contained a 1RS-7DS.7DL wheat-rye small segment translocation chromosome. In order to transfer the 1RS-7DS small segment translocation into hexaploid wheat, 58 lines of the F5 inbred population from the cross CD-13 x Chuanmai 42 were screened for rye chromosome segments by GISH and FISH analyses. The results showed that 13 lines contained the 1RS-7DS.7DL small segment translocation chromosome by reciprocal translocation between 1RS and 7DS. These translocation lines carrying 1RS small rye alien segment were tested for the translocation breakpoints and the presence of a storage protein locus Sec-1. The Sec-1 locus was absent in the line 811, a stable 1RS-7DS.7DL small segment translocation line. The translocation breakpoint of 1RS-7DS.7DL of this line was located in the interval of IB267-IAG95 around the telomere of 1RS chromosome. Thousand-kernel weight of the line 811 was much higher than the parent CD-13, but not significantly different from Chuanmai 42. This indicated that 1RS-7DS.7DL small segment translocation had no negative effect on thousand-kernel weight in the genetic background of Chuanmai 42. The line with 1RS-7DS.7DL translocation chromosomes can be used as a new genetic material for further studies of valuable genes and their genetic effect on 1RS small segment. PMID:26351056

  19. B cells expressing IL-10 mRNA modulate memory T cells after DNA-Hsp65 immunization.

    PubMed

    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 ?, 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. PMID:26397973

  20. RelB Is Differentially Regulated by I?B Kinase-? in B Cells and Mouse Lung by Cigarette Smoke

    PubMed Central

    Yang, Se-Ran; Yao, Hongwei; Rajendrasozhan, Saravanan; Chung, Sangwoon; Edirisinghe, Indika; Valvo, Samantha; Fromm, George; McCabe, Michael J.; Sime, Patricia J.; Phipps, Richard P.; Li, Jian-Dong; Bulger, Michael; Rahman, Irfan

    2009-01-01

    The activation of transcription factor NF-?B is controlled by two main pathways: the classical canonical (RelA/p65-p50)- and the alternative noncanonical (RelB/p52)–NF-?B pathways. RelB has been shown to play a protective role in RelA/p65-mediated proinflammatory cytokine release in immune–inflammatory lymphoid cells. Increased infiltration of macrophages and lymphoid cells occurs in lungs of patients with chronic obstructive pulmonary disease, leading to abnormal inflammation. We hypothesized that RelB, and its signaling pathway, is differentially regulated in macrophages and B cells and in lung cells, leading to differential regulation of proinflammatory cytokines in response to cigarette smoke (CS). CS exposure increased the levels of RelB and NF-?B–inducing kinase associated with recruitment of RelB on promoters of the IL-6 and macrophage inflammatory protein-2 genes in mouse lung. Treatment of macrophage cell line, MonoMac6, with CS extract showed activation of RelB. In contrast, RelB was degraded by a proteasome-dependent mechanism in B lymphocytes (human Ramos, mouse WEHI-231, and primary mouse spleen B cells), suggesting that RelB is differentially regulated in lung inflammatory and lymphoid cells in response to CS exposure. Transient transfection of dominant negative I?B-kinase-? and double mutants of NF-?B–inducing kinase partially attenuated the CS extract–mediated loss of RelB in B cells and normalized the increased RelB level in macrophages. Taken together, these data suggest that RelB is differentially regulated in response to CS exposure in macrophages, B cells, and in lung cells by I?B-kinase-?–dependent mechanism. Rapid degradation of RelB signals for RelA/p65 activation and loss of its protective ability to suppress the proinflammatory cytokine release in lymphoid B cells. PMID:18688039

  1. A Soluble BAFF Antagonist, BR3-Fc, Decreases Peripheral Blood B Cells and Lymphoid Tissue Marginal Zone and Follicular B Cells in Cynomolgus Monkeys

    PubMed Central

    Vugmeyster, Yulia; Seshasayee, Dhaya; Chang, Wesley; Storn, Anahid; Howell, Kathy; Sa, Susan; Nelson, Tenea; Martin, Flavius; Grewal, Iqbal; Gilkerson, Ellen; Wu, Ben; Thompson, Jeff; Ehrenfels, Barbara N.; Ren, Song; Song, An; Gelzleichter, Thomas R.; Danilenko, Dimitry M.

    2006-01-01

    BAFF (also known as BLyS), a member of the tumor necrosis factor superfamily, plays a critical role in the maturation and development of