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Sample records for human b-cell growth

  1. Improved fusion technique. I. Human umbilical cord serum, a new and potent growth promoter, compared with other B cell and hybridoma activators.

    Science.gov (United States)

    Westerwoudt, R J; Blom, J; Naipal, A M; Van Rood, J J

    1983-08-12

    Accelerated proliferation of hybridoma cells was observed in the presence of human umbilical cord serum (HUCS). This had very strong growth-promoting activity, even at a concentration of 2%. A comparison was made between HUCS and other B cell growth promoters, such as lipopolysaccharide (LPS) and dextran sulfate (DxS), macrophage supernatant, and human endothelial culture supernatant (HECS). The growth-promoting effect of HUCS was superior. Using a microcytotoxicity assay, we found no significant differences in the number of antibody producing clones with the various culture media, except for fetal calf serum.

  2. Advances in human B cell phenotypic profiling

    Directory of Open Access Journals (Sweden)

    Denise A Kaminski

    2012-10-01

    Full Text Available To advance our understanding and treatment of disease, research immunologists have been called-upon to place more centralized emphasis on impactful human studies. Such endeavors will inevitably require large-scale study execution and data management regulation (Big Biology, necessitating standardized and reliable metrics of immune status and function. A well-known example setting this large-scale effort in-motion is identifying correlations between eventual disease outcome and T lymphocyte phenotype in large HIV-patient cohorts using multiparameter flow cytometry. However, infection, immunodeficiency, and autoimmunity are also characterized by correlative and functional contributions of B lymphocytes, which to-date have received much less attention in the human Big Biology enterprise. Here, we review progress in human B cell phenotyping, analysis, and bioinformatics tools that constitute valuable resources for the B cell research community to effectively join in this effort.

  3. HSPH1 inhibition downregulates Bcl-6 and c-Myc and hampers the growth of human aggressive B-cell non-Hodgkin lymphoma.

    Science.gov (United States)

    Zappasodi, Roberta; Ruggiero, Giusi; Guarnotta, Carla; Tortoreto, Monica; Tringali, Cristina; Cavanè, Alessandra; Cabras, Antonello D; Castagnoli, Lorenzo; Venerando, Bruno; Zaffaroni, Nadia; Gianni, Alessandro M; De Braud, Filippo; Tripodo, Claudio; Pupa, Serenella M; Di Nicola, Massimo

    2015-03-12

    We have shown that human B-cell non-Hodgkin lymphomas (B-NHLs) express heat shock protein (HSP)H1/105 in function of their aggressiveness. Here, we now clarify its role as a functional B-NHL target by testing the hypothesis that it promotes the stabilization of key lymphoma oncoproteins. HSPH1 silencing in 4 models of aggressive B-NHLs was paralleled by Bcl-6 and c-Myc downregulation. In vitro and in vivo analysis of HSPH1-silenced Namalwa cells showed that this effect was associated with a significant growth delay and the loss of tumorigenicity when 10(4) cells were injected into mice. Interestingly, we found that HSPH1 physically interacts with c-Myc and Bcl-6 in both Namalwa cells and primary aggressive B-NHLs. Accordingly, expression of HSPH1 and either c-Myc or Bcl-6 positively correlated in these diseases. Our study indicates that HSPH1 concurrently favors the expression of 2 key lymphoma oncoproteins, thus confirming its candidacy as a valuable therapeutic target of aggressive B-NHLs.

  4. Comparative In Vitro Immune Stimulation Analysis of Primary Human B Cells and B Cell Lines

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    Van Belle, Kristien; Herman, Jean; Boon, Louis; Waer, Mark

    2016-01-01

    B cell specific immunomodulatory drugs still remain an unmet medical need. Utilisation of validated simplified in vitro models would allow readily obtaining new insights in the complexity of B cell regulation. For this purpose we investigated which human B lymphocyte stimulation assays may be ideally suited to investigate new B lymphocyte immunosuppressants. Primary polyclonal human B cells underwent in vitro stimulation and their proliferation, production of immunoglobulins (Igs) and of cytokines, and expression of cell surface molecules were analysed using various stimuli. ODN2006, a toll-like receptor 9 (TLR9) agonist, was the most potent general B cell stimulus. Subsequently, we investigated on which human B cell lines ODN2006 evoked the broadest immunostimulatory effects. The Namalwa cell line proved to be the most responsive upon TLR9 stimulation and hence may serve as a relevant, homogeneous, and stable B cell model in an in vitro phenotypic assay for the discovery of new targets and inhibitors of the B cell activation processes. As for the read-out for such screening assay, it is proposed that the expression of activation and costimulatory surface markers reliably reflects B lymphocyte activation. PMID:28116319

  5. A B-Cell Superantigen Induces the Apoptosis of Murine and Human Malignant B Cells

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    Lorenzo, Daniela; Duarte, Alejandra; Mundiñano, Juliana; Berguer, Paula; Nepomnaschy, Irene; Piazzon, Isabel

    2016-01-01

    B-cell superantigens (Sags) bind to conserved sites of the VH or VL regions of immunoglobulin molecules outside their complementarity-determining regions causing the apoptosis of normal cognate B cells. No attempts to investigate whether B-cell Sags are able to induce the apoptosis of cognate malignant B cells were reported. In the present study we show that protein L (PpL), secreted by Finegoldia magna, a B-cell Sag which interacts with κ+ bearing cells, induces the apoptosis of murine and human κ+ lymphoma B cells both in vitro and in vivo. Apoptosis was not altered by caspase-8 inhibitor. No alterations in the levels of Bid, Fas and Fas-L were found suggesting that PpL does not activate the extrinsic pathway of apoptosis. The involvement of the intrinsic pathway was clearly indicated by: i) alterations in mitochondrial membrane potential (ΔΨm) both in murine and human lymphoma cells exposed to PpL; ii) decreased levels of apoptosis in the presence of caspase-9 inhibitor; iii) significant increases of Bim and Bax protein levels and downregulation of Bcl-2; iv) the translocation from the cytoplasm to the mitochondria of Bax and Bim pro-apoptotic proteins and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor and v) the translocation of Bcl-2 protein from the mitochondria to the cytosol and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor. The possibility of a therapeutic use of Sags in lymphoma/leukemia B cell malignancies is discussed. PMID:27603942

  6. Regulation of VH replacement by B cell receptor-mediated signaling in human immature B cells.

    Science.gov (United States)

    Liu, Jing; Lange, Miles D; Hong, Sang Yong; Xie, Wanqin; Xu, Kerui; Huang, Lin; Yu, Yangsheng; Ehrhardt, Götz R A; Zemlin, Michael; Burrows, Peter D; Su, Kaihong; Carter, Robert H; Zhang, Zhixin

    2013-06-01

    VH replacement provides a unique RAG-mediated recombination mechanism to edit nonfunctional IgH genes or IgH genes encoding self-reactive BCRs and contributes to the diversification of Ab repertoire in the mouse and human. Currently, it is not clear how VH replacement is regulated during early B lineage cell development. In this article, we show that cross-linking BCRs induces VH replacement in human EU12 μHC(+) cells and in the newly emigrated immature B cells purified from peripheral blood of healthy donors or tonsillar samples. BCR signaling-induced VH replacement is dependent on the activation of Syk and Src kinases but is inhibited by CD19 costimulation, presumably through activation of the PI3K pathway. These results show that VH replacement is regulated by BCR-mediated signaling in human immature B cells, which can be modulated by physiological and pharmacological treatments.

  7. Activation-Induced Cytidine Deaminase Expression in Human B Cell Precursors Is Essential for Central B Cell Tolerance.

    Science.gov (United States)

    Cantaert, Tineke; Schickel, Jean-Nicolas; Bannock, Jason M; Ng, Yen-Shing; Massad, Christopher; Oe, Tyler; Wu, Renee; Lavoie, Aubert; Walter, Jolan E; Notarangelo, Luigi D; Al-Herz, Waleed; Kilic, Sara Sebnem; Ochs, Hans D; Nonoyama, Shigeaki; Durandy, Anne; Meffre, Eric

    2015-11-17

    Activation-induced cytidine deaminase (AID), the enzyme-mediating class-switch recombination (CSR) and somatic hypermutation (SHM) of immunoglobulin genes, is essential for the removal of developing autoreactive B cells. How AID mediates central B cell tolerance remains unknown. We report that AID enzymes were produced in a discrete population of immature B cells that expressed recombination-activating gene 2 (RAG2), suggesting that they undergo secondary recombination to edit autoreactive antibodies. However, most AID+ immature B cells lacked anti-apoptotic MCL-1 and were deleted by apoptosis. AID inhibition using lentiviral-encoded short hairpin (sh)RNA in B cells developing in humanized mice resulted in a failure to remove autoreactive clones. Hence, B cell intrinsic AID expression mediates central B cell tolerance potentially through its RAG-coupled genotoxic activity in self-reactive immature B cells.

  8. Exploiting human memory B cell heterogeneity for improved vaccine efficacy

    Directory of Open Access Journals (Sweden)

    Noel Thomas Pauli

    2011-12-01

    Full Text Available The major goal in vaccination is establishment of long-term, prophylactic humoral memory to a pathogen. Two major components to long-lived humoral memory are plasma cells for the production of specific immunoglobulin and memory B cells that survey for their specific antigen in the periphery for later affinity maturation, proliferation, and differentiation. The study of human B cell memory has been aided by the discovery of a general marker for B cell memory, expression of CD27; however, new data suggests the existence of CD27- memory B cells as well. These recently described non-canonical memory populations have increasingly pointed to the heterogeneity of the memory compartment. The novel B memory subsets in humans appear to have unique origins, localization, and functions compared to what was considered to be a classical memory B cell. In this article, we review the known B cell memory subsets, the establishment of B cell memory in vaccination and infection, and how understanding these newly described subsets can inform vaccine design and disease treatment.

  9. Human regulatory B cells control the TFH cell response.

    Science.gov (United States)

    Achour, Achouak; Simon, Quentin; Mohr, Audrey; Séité, Jean-François; Youinou, Pierre; Bendaoud, Boutahar; Ghedira, Ibtissem; Pers, Jacques-Olivier; Jamin, Christophe

    2017-07-01

    Follicular helper T (TFH) cells support terminal B-cell differentiation. Human regulatory B (Breg) cells modulate cellular responses, but their control of TFH cell-dependent humoral immune responses is unknown. We sought to assess the role of Breg cells on TFH cell development and function. Human T cells were polyclonally stimulated in the presence of IL-12 and IL-21 to generate TFH cells. They were cocultured with B cells to induce their terminal differentiation. Breg cells were included in these cultures, and their effects were evaluated by using flow cytometry and ELISA. B-cell lymphoma 6, IL-21, inducible costimulator, CXCR5, and programmed cell death protein 1 (PD-1) expressions increased on stimulated human T cells, characterizing TFH cell maturation. In cocultures they differentiated B cells into CD138(+) plasma and IgD(-)CD27(+) memory cells and triggered immunoglobulin secretions. Breg cells obtained by Toll-like receptor 9 and CD40 activation of B cells prevented TFH cell development. Added to TFH cell and B-cell cocultures, they inhibited B-cell differentiation, impeded immunoglobulin secretions, and expanded Foxp3(+)CXCR5(+)PD-1(+) follicular regulatory T cells. Breg cells modulated IL-21 receptor expressions on TFH cells and B cells, and their suppressive activities involved CD40, CD80, CD86, and intercellular adhesion molecule interactions and required production of IL-10 and TGF-β. Human Breg cells control TFH cell maturation, expand follicular regulatory T cells, and inhibit the TFH cell-mediated antibody secretion. These novel observations demonstrate a role for the Breg cell in germinal center reactions and suggest that deficient activities might impair the TFH cell-dependent control of humoral immunity and might lead to the development of aberrant autoimmune responses. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  10. Transitional B cells in early human B cell development - time to revisit the paradigm?

    Directory of Open Access Journals (Sweden)

    Victoria G Martin

    2016-12-01

    Full Text Available The B cell repertoire is generated in the adult bone marrow by an ordered series of gene rearrangement processes that result in massive diversity of immunoglobulin (Ig genes, and consequently an equally large number of potential specificities for antigen. As the process is essentially random, then cells exhibiting excess reactivity with self-antigens are generated and need to be removed from the repertoire before the cells are fully mature. Some of the cells are deleted, and some will undergo receptor editing to see if changing the light chain can rescue an autoreactive antibody. As a consequence, the binding properties of the B cell receptor are changed as development progresses through pre-B>>immature>>transitional>>naïve phenotypes. Using long-read, high-throughput, sequencing we have produced a unique set of sequences from these four cell types in human bone marrow and matched peripheral blood and our results describe the effects of tolerance selection on the B cell repertoire at the Ig gene level. Most strong effects of selection are seen within the heavy chain repertoire, and can be seen both in gene usage and in CDR-H3 characteristics. Age-related changes are small and only the size of the CDR-H3 shows constant and significant change in these data. The paucity of significant changes in either kappa or lambda light chain repertoires implies that either the heavy chain has more influence over autoreactivity than light chain and/or that switching between kappa and lambda light chains, as opposed to switching within the light chain loci, may effect a more successful autoreactive rescue by receptor editing. Our results show that the transitional cell population contains cells other than those that are part of the pre-B>>immature>>transitional>>naïve development pathway, since the population often shows a repertoire that is outside the trajectory of gene loss/gain between pre-B and naïve stages.

  11. Human peripheral blood B-Cell compartments: A crossroad in B-cell traffic

    NARCIS (Netherlands)

    M. Perez-Andres; B. Paiva; W.G. Nieto (Wendy); A. Caraux; A. Schmitz; J. Almeida (Julia); R.F. Vogt; G.E. Marti; A.C. Rawstron; M.C. van Zelm (Menno); J.J.M. van Dongen (Jacques); H.E. Johnsen (Hans); B. Klein (Binie); A. Orfao (Alberto)

    2010-01-01

    textabstractA relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lympho

  12. Human Peripheral Blood B-Cell Compartments : A Crossroad in B-Cell Traffic

    NARCIS (Netherlands)

    Perez-Andres, M.; Paiva, B.; Nieto, W. G.; Caraux, A.; Schmitz, A.; Almeida, J.; Vogt, R. F.; Marti, G. E.; Rawstron, A. C.; Van Zelm, M. C.; Van Dongen, J. J. M.; Johnsen, H. E.; Klein, B.; Orfao, A.

    2010-01-01

    A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues.

  13. Human Peripheral Blood B-Cell Compartments : A Crossroad in B-Cell Traffic

    NARCIS (Netherlands)

    Perez-Andres, M.; Paiva, B.; Nieto, W. G.; Caraux, A.; Schmitz, A.; Almeida, J.; Vogt, R. F.; Marti, G. E.; Rawstron, A. C.; Van Zelm, M. C.; Van Dongen, J. J. M.; Johnsen, H. E.; Klein, B.; Orfao, A.

    2010-01-01

    A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues.

  14. BAFF enhances chemotaxis of primary human B cells: a particular synergy between BAFF and CXCL13 on memory B cells.

    Science.gov (United States)

    Badr, Gamal; Borhis, Gwenoline; Lefevre, Eric A; Chaoul, Nada; Deshayes, Frederique; Dessirier, Valérie; Lapree, Genevieve; Tsapis, Andreas; Richard, Yolande

    2008-03-01

    B-cell-activating factor of the TNF family, (BAFF), and a proliferation-inducing ligand (APRIL) regulate B-lymphocyte survival and activation. We report that BAFF, but not APRIL, increased the chemotactic response of primary human B cells to CCL21, CXCL12, and CXCL13. The BAFF-induced increase in B-cell chemotaxis was totally abolished by blockade of BAFF-R and was strongly dependent on the activation of PI3K/AKT, NF-kappaB, and p38MAPK pathways. BAFF had similar effects on the chemotaxis of naive and memory B cells in response to CCL21 but increased more strongly that of memory B cells to CXCL13 than that of naive B cells. Our findings indicate a previously unreported role for the BAFF/BAFF-R pair in mature B-cell chemotaxis. The synergy between CXCL13 and BAFF produced by stromal cells and follicular dendritic cells may have important implications for B-cell homeostasis, the development of normal B-cell areas, and for the formation of germinal center-like follicles that may be observed in various autoimmune diseases.

  15. Transitional B Cells in Early Human B Cell Development – Time to Revisit the Paradigm?

    Science.gov (United States)

    Martin, Victoria G.; Wu, Yu-Chang Bryan; Townsend, Catherine L.; Lu, Grace H. C.; O’Hare, Joselli Silva; Mozeika, Alexander; Coolen, Anthonius C. C.; Kipling, David; Fraternali, Franca; Dunn-Walters, Deborah K.

    2016-01-01

    The B cell repertoire is generated in the adult bone marrow by an ordered series of gene rearrangement processes that result in massive diversity of immunoglobulin (Ig) genes and consequently an equally large number of potential specificities for antigen. As the process is essentially random, the cells exhibiting excess reactivity with self-antigens are generated and need to be removed from the repertoire before the cells are fully mature. Some of the cells are deleted, and some will undergo receptor editing to see if changing the light chain can rescue an autoreactive antibody. As a consequence, the binding properties of the B cell receptor are changed as development progresses through pre-B ≫ immature ≫ transitional ≫ naïve phenotypes. Using long-read, high-throughput, sequencing we have produced a unique set of sequences from these four cell types in human bone marrow and matched peripheral blood, and our results describe the effects of tolerance selection on the B cell repertoire at the Ig gene level. Most strong effects of selection are seen within the heavy chain repertoire and can be seen both in gene usage and in CDRH3 characteristics. Age-related changes are small, and only the size of the CDRH3 shows constant and significant change in these data. The paucity of significant changes in either kappa or lambda light chain repertoires implies that either the heavy chain has more influence over autoreactivity than light chain and/or that switching between kappa and lambda light chains, as opposed to switching within the light chain loci, may effect a more successful autoreactive rescue by receptor editing. Our results show that the transitional cell population contains cells other than those that are part of the pre-B ≫ immature ≫ transitional ≫ naïve development pathway, since the population often shows a repertoire that is outside the trajectory of gene loss/gain between pre-B and naïve stages. PMID:27994589

  16. Lidamycin Induces Apoptosis of B-Cell Lymphoma Cells and Inhibits Xenograft Growth in Nude Mice

    Institute of Scientific and Technical Information of China (English)

    Hong Fang; Shenghua Zhang; Qingfang Miao; Dongsheng Xiong; Yongsu Zhen

    2009-01-01

    OBJECTIVE To study the cytotoxicity of Lidamycin (LDM) and its induction of apoptosis in Raji and Daudi cells of B-cell lymphoma, and the inhibition of growth of the lymphoma Raji xenograft in nude mice.METHODS MTT assay was used to observe the inhibition by LDM on the proliferation of the Raji and Daudi cells. Annexin V-FITC/PI double-stain, in combination with flow cytometry (FCM), was used to determine the induction of apoptosis by LDM in Raji cells. The B-cell lymphoma Raji xenograft model in nude mice was set up to detect the in vivo antitumor activity of LDM.RESULTS LDM markedly inhibited the proliferation of the Raji and Daudi cells in vitro, with IC50 values of 7.13×10-11 mol/L and 2.91×10-10 mol/L, respectively. The apoptotic rates of Raji cells were respectively 77.98% and 67.63% at 0.5 nmol/L and 0.25 nmol/L of LDM, indicating an obvious induction of apoptosis in Raji cells. LDM inhibited the formation and growth of human B-cell lymphoma Raji xenograft in nude mice. The inhibition rates of tumor growth were respectively 74.9% and 65.2% in LDM at dosage group of 0.05 mg/kg and 0.025 mg/kg, suggesting an apparent prolongation of survival time in the nude mouse bearing lymphoma.CONCLUSION LDM can effectively induce apoptosis of the B-cell lymphoma cells and inhibit the xenograft growth in nude mice.

  17. Effects of Lu-Do-Huang Extract (LDHE) on Apoptosis Induction in Human Hep3B Cells.

    Science.gov (United States)

    Huang, Hui-Yu; Chen, Li-Han; Liu, Chen-Wei; Chien, Ting-Yi; Yu, Yu-Ping; Kao, Yu-Yu; Yang, Jo-Hsuan; Tsai, Ying-Chieh

    2015-06-30

    Lu-Do-Huang (Pracparatum mungo) is a fermented mung bean [corrected] (Vigna radiata) and has long been used as a traditional and functional food in Traditional Chinese Medicine, especially for treating a variety of liver disorders. The present study aimed to evaluate the apoptotic effects of Lu-Do-Huang ethanol extract (LDHE) on Hep3B cells, a human hepatoma cell line. A variety of cellular assays, flow cytometry and immunoblotting were used. Our results showed that LDHE significantly inhibited Hep3B cells growth. Additionally, the cell cycle assay showed that LDHE prevented Hep3B cell entry into S phase and led to an arrest of Hep3B cells in the G₀/G₁ phase. LDHE induced Hep3B cells to undergo apoptosis as determined through Hep3B cell morphology changes, increase of apoptotic bodies, apoptotic cells, DNA fragmentations and caspase activity. We further examined the protein expression of TRADD, FADD, and Bax to verify the possible apoptotic pathways. The results indicated that LDHE-induced apoptosis in Hep3B cells might be mediated [corrected] by an extrinsic signaling pathway leading to an induction of apoptosis in Hep3B cells. In conclusion, LDHE induced apoptosis and cell cycle arrest in Hep3B cells. Our data provide the evidences regarding the anti-hepatoma potential of LDHE in Hep3B cells.

  18. Dualistic effects of tetrandrine on growth in human hepatoma 3b cells%汉防己碱对肝癌Hep3b细胞生长的双向作用

    Institute of Scientific and Technical Information of China (English)

    蒋心惠; 黄开顺; 滕永真; 何百成; 周岐新

    2012-01-01

    Objective To determine the effects of tetrandrine (Tet) on the growth in human hepatoma 3b ( Hep3b) cells. Methods Flow cytometry, MTT assay, and Western blotting were used to investigate the effects of Tet (0. 33 to 1. 0 μg/ml) on the growth of Hep3b and Hep3b/5-Fu cells. Results Tet resulted in a decreased survival rate of Hep3b cells in a dose-dependent manner. Tet of 0.5 and 1.0 (xg/ral significantly increased the IC50 of 5-fluorouracil (5-Fu) to Hep3b cells, whereas reduced the IC50 of 5-FU to Hep3b/5-Fu cells. Tet of 0. 33μg/ml significantly increased the IC50 of Cisplatin (cDDP) to Hep3b/5-Fu cells, but that of 0.5 and 1.0 μg/ml significantly reduced its IC50 to Hep3b/5-Fu cells. Treatment of 1.0 μg/ml Tet for 48 h obviously resulted in an up-regulation of P-gp and MRP1 in the Hep3b cells (P<0.05). Our results indicated that Tet exerted inhibitory effect on Hep3b growth, and it at high concentration reversed the resistance of Hep3b/5-Fu cells to 5-Fu and enhanced the cytotoxic effect of cDDP on these Hep3b/5-Fu cells. Conclusion Tet shows a dose-related dualistic effects on the growth of Hep3b and Hep3b/5-Fu cells, which might be related with the up-regulating of P-gp and MRP1.%目的 考察汉防已碱(tetrandrine,Tet)对肝癌Hep3b和Hep3b/5-Fu细胞生长的影响.方法 采用体外细胞培养,结合流式细胞术、MTT和Western blot方法研究Tet(0.33 ~ 1.0μg/ml)对肝癌Hep3b及Hep3b/5-Fu细胞生长的作用特点.结果 Tet在0.33~1.0 μg/ml时呈浓度依赖性降低Hep3b细胞存活率;0.5和1.0 μg/ml显著提高5-Fu对Hep3b细胞的IC50,但降低5-Fu对Hep3b/5-Fu细胞的IC50;0.33 μg/ml的Tet明显增加cDDP对Hep3b/5-Fu细胞的IC50,而0.5和1.0μg/ml显著降低cDDP对Hep3b/5-Fu细胞的IC50(P<0.01).1.0 μg/ml的Tet作用48 h后使Hep3b细胞中的P-gp和MRP1表达明显上调(P<0.05).Tet单用对Hep3b细胞生长有一定抑制作用,高浓度Tet逆转Hep3b/5-Fu细胞对5-Fu耐药和增强cDDP对Hep3b/5-Fu细胞生长的

  19. Human B cells produce chemokine CXCL10 in the presence of Mycobacterium tuberculosis specific T cells

    DEFF Research Database (Denmark)

    Hoff, Soren T; Salman, Ahmed M; Ruhwald, Morten

    2015-01-01

    BACKGROUND: The role of B cells in human host response to Mycobacterium tuberculosis (Mtb) infection is still controversial, but recent evidence suggest that B cell follicle like structures within the lung may influence host responses through regulation of the local cytokine environment....... A candidate for such regulation could be the chemokine CXCL10. CXCL10 is mainly produced by human monocytes, but a few reports have also found CXCL10 production by human B cells. The objective of this study was to investigate CXCL10 production by human B cells in response to in vitro stimulation with Mtb...... antigens. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed human blood samples from 30 volunteer donors using multiparameter flow cytometry, and identified a subgroup of B cells producing CXCL10 in response to in vitro stimulation with antigens. T cells did not produce CXCL10, but CXCL10 production by B cells...

  20. Altered B cell receptor signaling in human systemic lupus erythematosus

    Science.gov (United States)

    Jenks, Scott A.; Sanz, Iñaki

    2009-01-01

    Regulation of B cell receptor signaling is essential for the development of specific immunity while retaining tolerance to self. Systemic lupus erythematosus (SLE) is characterized by a loss of B cell tolerance and the production of anti-self antibodies. Accompanying this break down in tolerance are alterations in B cell receptor signal transduction including elevated induced calcium responses and increased protein phosphorylation. Specific pathways that negatively regulate B cell signaling have been shown to be impaired in some SLE patients. These patients have reduced levels of the kinase Lyn in lipid raft microdomains and this reduction is inversely correlated with increased CD45 in lipid rafts. Function and expression of the inhibitory immunoglobulin receptor FcγRIIB is also reduced in Lupus IgM- CD27+ memory cells. Because the relative contribution of different memory and transitional B cell subsets can be abnormal in SLE patients, we believe studies targeted to well defined B cell subsets will be necessary to further our understanding of signaling abnormalities in SLE. Intracellular flow cytometric analysis of signaling is a useful approach to accomplish this goal. PMID:18723129

  1. Human innate B cells: a link between host defense and autoimmunity?

    Science.gov (United States)

    Milner, Eric C B; Anolik, Jennifer; Cappione, Amedeo; Sanz, Iñaki

    2005-03-01

    B cells play a variety of immunoregulatory roles through their antigen-presentation ability and through cytokine and chemokine production. Innate immune activation of B cells may play a beneficial role through the generation of natural cross-reactive antibodies, by maintaining B cell memory and by exercising immunomodulatory functions that may provide protection against autoimmunity. In this article, we review human B cell populations and their functional properties, with a particular focus on a population of inherently autoreactive B cells, which seem to play an important physiological role in innate immunity, but which, if selected into adaptive immune responses, appear to become pathogenic agents in systemic lupus erythematosus.

  2. Antibody-Independent Function of Human B Cells Contributes to Antifungal T Cell Responses.

    Science.gov (United States)

    Li, Rui; Rezk, Ayman; Li, Hulun; Gommerman, Jennifer L; Prat, Alexandre; Bar-Or, Amit

    2017-03-08

    Fungal infections (e.g., Candida albicans) can manifest as serious medical illnesses, especially in the elderly and immune-compromised hosts. T cells are important for Candida control. Whether and how B cells are involved in antifungal immunity has been less clear. Although patients with agammaglobulinemia exhibit normal antifungal immunity, increased fungal infections are reported following B cell-depleting therapy, together pointing to Ab-independent roles of B cells in controlling such infections. To test how human B cells may contribute to fungal-associated human T cell responses, we developed a novel Ag-specific human T cell/B cell in vitro coculture system and found that human B cells could induce C. albicans-associated, MHC class II-restricted responses of naive T cells. Activated B cells significantly enhanced C. albicans-mediated Th1 and Th17 T cell responses, which were both strongly induced by CD80/CD86 costimulation. IL-6(+)GM-CSF(+) B cells were the major responding B cell subpopulation to C. albicans and provided efficient costimulatory signals to the T cells. In vivo B cell depletion in humans resulted in reduced C. albicans-associated T responses. Of note, the decreased Th17, but not Th1, responses could be reversed by soluble factors from B cells prior to depletion, in an IL-6-dependent manner. Taken together, our results implicate an Ab-independent cytokine-defined B cell role in human antifungal T cell responses. These findings may be particularly relevant given the prospects of chronic B cell depletion therapy use in lymphoma and autoimmune disease, as patients age and are exposed to serial combination therapies.

  3. Idiotype vaccines for human B-cell malignancies.

    Science.gov (United States)

    Inoges, S; de Cerio, A Lopez-Diaz; Soria, E; Villanueva, H; Pastor, F; Bendandi, M

    2010-01-01

    After twenty years of use in humans, customized idiotypic vaccination yet remains a non-approved, experimental therapeutic option for patients with lymphoma and myeloma. Potentially applicable to all B-cell malignancies whose cells express a clonal immunoglobulin or its epitopes on their surface, this treatment is designed to prevent disease recurrence or progression. Mostly used in follicular lymphoma patients so far, idiotype vaccines have clearly shown biological efficacy, clinical efficacy and clinical benefit in this setting, although no study aiming at regulatory approval of the procedure has been able to meet its main clinical endpoints. In mantle cell lymphoma, only biological efficacy has been proven for idiotypic vaccination, while in multiple myeloma a limited number of studies support the notion of biological and perhaps even clinical efficacy, although no credible evidence of clinical benefit has still emerged. Idiotype vaccines have been produced and administered in a number of substantially different manners. Therefore, the results of most clinical trials cannot be easily compared, and even less pooled together in meaningful meta-analyses. A more creative and yet scientifically sound way to design clinical trials of customized active immunotherapies will be key to the future development of idiotype vaccines, particularly considering that we currently lack any clinical or biological indicator to possibly predict which patients are more likely to respond to idiotypic vaccination from an immunologic point of view. This review aims at summarizing the multifaceted success achieved by idiotype vaccines, as well as at outlining the challenges awaiting them in the near future: how to improve feasibility, immunogenicity and efficacy, as well as how to confirm benefit and gain regulatory approval.

  4. Interleukin-24 inhibits the plasma cell differentiation program in human germinal center B cells.

    Science.gov (United States)

    Maarof, Ghyath; Bouchet-Delbos, Laurence; Gary-Gouy, Hélène; Durand-Gasselin, Ingrid; Krzysiek, Roman; Dalloul, Ali

    2010-03-04

    Complex molecular mechanisms control B-cell fate to become a memory or a plasma cell. Interleukin-24 (IL-24) is a class II family cytokine of poorly understood immune function that regulates the cell cycle. We previously observed that IL-24 is strongly expressed in leukemic memory-type B cells. Here we show that IL-24 is also expressed in human follicular B cells; it is more abundant in CD27(+) memory B cells and CD5-expressing B cells, whereas it is low to undetectable in centroblasts and plasma cells. Addition of IL-24 to B cells, cultured in conditions shown to promote plasma cell differentiation, strongly inhibited plasma cell generation and immunoglobulin G (IgG) production. By contrast, IL-24 siRNA increased terminal differentiation of B cells into plasma cells. IL-24 is optimally induced by BCR triggering and CD40 engagement; IL-24 increased CD40-induced B-cell proliferation and modulated the transcription of key factors involved in plasma cell differentiation. It also inhibited activation-induced tyrosine phosphorylation of signal transducer and activator of transcription-3 (STAT-3), and inhibited the transcription of IL-10. Taken together, our results indicate that IL-24 is a novel cytokine involved in T-dependent antigen (Ag)-driven B-cell differentiation and suggest its physiologic role in favoring germinal center B-cell maturation in memory B cells at the expense of plasma cells.

  5. Adhesion of Human B Cells to Germinal Centers in Vitro Involves VLA-4 and INCAM-110

    Science.gov (United States)

    Freedman, Arnold S.; Munro, J. Michael; Rice, G. Edgar; Bevilacqua, Michael P.; Morimoto, Chikao; McIntyre, Bradley W.; Rhynhart, Kurt; Pober, Jordan S.; Nadler, Lee M.

    1990-08-01

    Human B lymphocytes localize and differentiate within the microenvironment of lymphoid germinal centers. A frozen section binding assay was developed for the identification of those molecules involved in the adhesive interactions between B cells and lymphoid follicles. Activated human B cells and B cell lines were found to selectively adhere to germinal centers. The VLA-4 molecule on the lymphocyte and the adhesion molecule INCAM-110, expressed on follicular dendritic cells, supported this interaction. This cellular interaction model can be used for the study of how B cells differentiate.

  6. Unusual patterns of immunoglobulin gene rearrangement and expression during human B cell ontogeny: human B cells can simultaneously express cell surface kappa and lambda light chains

    OpenAIRE

    1993-01-01

    Immunoglobulin gene rearrangement during mammalian B cell development generally follows an ordered progression, beginning with heavy (H) chain genes and proceeding through kappa and lambda light (L) chain genes. To determine whether the predicted kappa-->lambda hierarchy was occurring in vitro, we generated Epstein-Barr virus-transformed cell lines from cultures undergoing human pre-B cell differentiation. A total of 143 cell lines were established. 24 expressed cell surface mu/lambda by flow...

  7. Further evidence for a human B cell activating factor distinct from IL-4.

    Science.gov (United States)

    Diu, A; Février, M; Mollier, P; Charron, D; Banchereau, J; Reinherz, E L; Thèze, J

    1990-01-01

    Supernatants from activated human T cell clones were previously shown to contain B cell-activating factor (BCAF), an activity which results in polyclonal resting B cell stimulation. In the present study, we investigate the relationship between this activity and human interleukin-4 which was also shown to act on resting B cells. The supernatant of the T cell clone TT9 contains IL-4 but anti-IL-4 antiserum does not affect the response of B cells as measured by thymidine uptake or cell volume increase. Furthermore, IL-4 induces Fc epsilon-receptor (CD23) expression on 30% of unstimulated human B cells, whereas BCAF-containing supernatants from clone P2, that do not contain detectable amounts of IL-4, promote B cell proliferation without inducing CD23 expression. Our results therefore establish that IL-4 and BCAF are distinct activities and suggest that they trigger different activation pathways in human B cells. In addition, culture of B cells with T cell supernatants for 72 hr induces a three- to fourfold increase in the expression of HLA-DR, -DP, and -DQ antigens in 50% of B cells. The addition of inhibiting concentrations of anti-IFN-gamma, LT, or IL-4 antisera to the cultures does not change these results. Finally, 30% of B cells cultured with T cell supernatants leave the G1 phase of the cell cycle and 20% reach mitosis. Taken together, our findings further support the existence of a B cell-activating factor responsible for the activation of resting human B cells.

  8. Activation of resting human B cells by helper T-cell clone supernatant: characterization of a human B-cell-activating factor.

    Science.gov (United States)

    Diu, A; Gougeon, M L; Moreau, J L; Reinherz, E L; Thèze, J

    1987-12-01

    The effects of helper T-cell clone supernatants on resting human B cells were investigated. Four different helper T-cell clones (two T4+ and two T8+) were stimulated by anti-T3 monoclonal antibodies on Sepharose beads or anti-T11(2) plus anti-T11(3) monoclonal antibodies. The supernatants from these activated clones induced the proliferation of highly purified resting B lymphocytes from the peripheral blood. The B cells exhibited a cell size and a surface-antigen pattern (4F2 antigen and transferrin receptor) of phase G0 B cells, and they were functionally resting. In response to T-cell supernatants a large fraction of the B cells enlarged and expressed 4F2 antigens and transferrin receptors. In gel filtration, the corresponding activity migrated with an apparent Mr of 12,000-15,000. Our findings strongly support the existence of a human B-cell-activating factor acting on resting B cells and causing them to enter phase G1 of the cell cycle.

  9. Revisiting the B-cell compartment in mouse and humans: more than one B-cell subset exists in the marginal zone and beyond

    Directory of Open Access Journals (Sweden)

    Garraud Olivier

    2012-11-01

    . This review thus aims to describe novel findings regarding the B-cell compartments found in the mouse as a model organism, and in human physiology and pathology. It must be emphasised that some differences are noticeable between the mouse and human systems, thus increasing the complexity of B-cell compartmentalisation. Special attention will be given to the (lymph node and spleen marginal zones, which represent major crossroads for B-cell types and functions and a challenge for understanding better the role of B-cell specificities in innate and adaptive immunology.

  10. High levels of SOX5 decrease proliferative capacity of human B cells, but permit plasmablast differentiation.

    Directory of Open Access Journals (Sweden)

    Mirzokhid Rakhmanov

    Full Text Available Currently very little is known about the differential expression and function of the transcription factor SOX5 during B cell maturation. We identified two new splice variants of SOX5 in human B cells, encoding the known L-SOX5B isoform and a new shorter isoform L-SOX5F. The SOX5 transcripts are highly expressed during late stages of B-cell differentiation, including atypical memory B cells, activated CD21low B cells and germinal center B cells of tonsils. In tonsillar sections SOX5 expression was predominantly polarized to centrocytes within the light zone. After in vitro stimulation, SOX5 expression was down-regulated during proliferation while high expression levels were permissible for plasmablast differentiation. Overexpression of L-SOX5F in human primary B lymphocytes resulted in reduced proliferation, less survival of CD138neg B cells, but comparable numbers of CD138+CD38hi plasmablasts compared to control cells. Thus, our findings describe for the first time a functional role of SOX5 during late B cell development reducing the proliferative capacity and thus potentially affecting the differentiation of B cells during the germinal center response.

  11. Scarcity of autoreactive human blood IgA(+) memory B cells.

    Science.gov (United States)

    Prigent, Julie; Lorin, Valérie; Kök, Ayrin; Hieu, Thierry; Bourgeau, Salomé; Mouquet, Hugo

    2016-10-01

    Class-switched memory B cells are key components of the "reactive" humoral immunity, which ensures a fast and massive secretion of high-affinity antigen-specific antibodies upon antigenic challenge. In humans, IgA class-switched (IgA(+) ) memory B cells and IgA antibodies are abundant in the blood. Although circulating IgA(+) memory B cells and their corresponding secreted immunoglobulins likely possess major protective and/or regulatory immune roles, little is known about their specificity and function. Here, we show that IgA(+) and IgG(+) memory B-cell antibodies cloned from the same healthy humans share common immunoglobulin gene features. IgA and IgG memory antibodies have comparable lack of reactivity to vaccines, common mucosa-tropic viruses and commensal bacteria. However, the IgA(+) memory B-cell compartment contains fewer polyreactive clones and importantly, only rare self-reactive clones compared to IgG(+) memory B cells. Self-reactivity of IgAs is acquired following B-cell affinity maturation but not antibody class switching. Together, our data suggest the existence of different regulatory mechanisms for removing autoreactive clones from the IgG(+) and IgA(+) memory B-cell repertoires, and/or different maturation pathways potentially reflecting the distinct nature and localization of the cognate antigens recognized by individual B-cell populations.

  12. Disodium cromoglycate enhances ongoing immunoglobulin production in vitro in human B cells.

    Science.gov (United States)

    Kimata, H; Yoshida, A; Ishioka, C; Mikawa, H

    1991-01-01

    The effect of disodium cromoglycate (DSCG) upon human immunoglobulin (Ig) isotypes and IgG subclasses production by purified B cells was studied. DSCG enhanced IgM, IgG1, IgG2, IgG3, IgG4 and IgA production in a dose-dependent fashion, while DSCG failed to induce IgE production at any concentrations tested by purified B cells. When B cells were separated into small resting and large activated B cells, DSCG failed to induce Ig production from small resting B cells in the presence or absence of Staphylococcus aureus Cowan strain I (SAC). In contrast, in large activated B cells DSCG significantly enhanced all types of Ig production (two-to threefold), especially IgG4 production (seven-to 11-fold), except IgE, which large B cells did not produce. The enhancement of IgG subclass production was not subclass switching, since DSCG failed to enhance IgG1 production in B cells depleted of surface IgG1+ cells (sIgG1+ cells). Similarly, DSCG did not enhance IgG2, IgG3 or IgG4 production from sIgG2-, sIgG3- or sIgG4- B cells, respectively, Interleukin-4 (IL-4) or interleukin-6 (IL-6) also enhanced Ig production except IgG4 from large activated B cells. The enhancing effect of DSCG was not mediated by IL-4 or IL-6 since anti-IL-4 or anti-IL-6 antibody failed to block the DSCG-induced enhancement. DSCG also enhanced IgG2 and IgM production from human B-cell lines GM-1500 and CBL, respectively. These results suggest that DSCG directly and preferentially stimulates activated B cells which are producing Ig and, in addition, enhances their Ig production. PMID:1904400

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

    Science.gov (United States)

    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.

  14. Maternal and fetal mechanisms of B cell regulation during pregnancy: human Chorionic Gonadotropin stimulates B cells to produce IL-10 while alpha-fetoprotein drives them into apoptosis

    Directory of Open Access Journals (Sweden)

    Franziska Fettke

    2016-12-01

    Full Text Available Maternal immune tolerance towards the fetus is an essential requisite for pregnancy. While T cell functions are well documented, little is known about the participation of B cells. We have previously suggested that IL-10 producing B cells are involved in pregnancy tolerance in mice and humans. By employing murine and human systems, we report now that fetal trophoblasts positively regulate the generation of IL-10 producing B cells. We next studied the participation of hormones produced by the placenta as well as the fetal protein alpha-fetoprotein (AFP in B cell modulation. Human Chorionic Gonadotropin (hCG, but not progesterone, estrogen or a combination of both, was able to promote changes in B cell phenotype and boost their IL-10 production, which was abolished after blocking hCG. The hCG-induced B cell phenotype was not associated with augmented galactosylation, sialylation or fucosylation of IgG subclasses in their Fc. In vitro, hCG induced the synthesis of asymmetrically glycosylated antibodies in their Fab region. Interestingly, AFP had dual effects depending on the concentration. At concentrations corresponding to maternal serum levels, it did not modify the phenotype or IL-10 secretion of B cells. At fetal concentrations, however, AFP was able to drive B cells into apoptosis, which may indicate a protective mechanism to avoid maternal B cells to reach the fetus.Our data suggests that the fetus secrete factors that promote a pregnancy-friendly B cell phenotype, unraveling interesting aspects of B cell function and modulation by pregnancy hormones and fetal proteins.

  15. The human fetal lymphocyte lineage: identification by CD27 and LIN28B expression in B cell progenitors

    Science.gov (United States)

    McWilliams, Laurie; Su, Kuei-Ying; Liang, Xiaoe; Liao, Dongmei; Floyd, Serina; Amos, Joshua; Moody, M. Anthony; Kelsoe, Garnett; Kuraoka, Masayuki

    2013-01-01

    CD27, a member of the TNFR superfamily, is used to identify human memory B cells. Nonetheless, CD27+ B cells are present in patients with HIGM1 syndrome who are unable to generate GCs or memory B cells. CD27+IgD+ fetal B cells are present in umbilical cord blood, and CD27 may also be a marker of the human B1-like B cells. To define the origin of naïve CD27+IgD+ human B cells, we studied B cell development in both fetal and adult tissues. In human FL, most CD19+ cells coexpressed CD10, a marker of human developing B cells. Some CD19+CD10+ B cells expressed CD27, and these fetal CD27+ cells were present in the pro-B, pre-B, and immature/transitional B cell compartments. Lower frequencies of phenotypically identical cells were also identified in adult BM. CD27+ pro-B, pre-B, and immature/transitional B cells expressed recombination activating gene-1, terminal deoxynucleotidyl transferase and Vpre-B mRNA comparably to their CD27− counterparts. CD27+ and CD27− developing B cells showed similar Ig heavy chain gene usage with low levels of mutations, suggesting that CD27+ developing B cells are distinct from mutated memory B cells. Despite these similarities, CD27+ developing B cells differed from CD27− developing B cells by their increased expression of LIN28B, a transcription factor associated with the fetal lymphoid lineages of mice. Furthermore, CD27+ pro-B cells efficiently generated IgM+IgD+ immature/transitional B cells in vitro. Our observations suggest that CD27 expression during B cell development identifies a physiologic state or lineage for human B cell development distinct from the memory B cell compartment. PMID:23901121

  16. Innate Response Activator (IRA) B Cells Reside in Human Tonsils and Internalize Bacteria In Vitro.

    Science.gov (United States)

    Chiappini, Nico; Cantisani, Rocco; Pancotto, Laura; Ruggiero, Paolo; Rosa, Domenico; Manetti, Andrea; Romano, Antonio; Montagnani, Francesca; Bertholet, Sylvie; Castellino, Flora; Del Giudice, Giuseppe

    2015-01-01

    Innate response activator (IRA) B cells have been described in mice as a subset of B-1a B cells that produce granulocyte/macrophage colony-stimulating factor (GM-CSF) and have been found in the spleen upon activation. In humans, identification, tissue localization and functionality of these lymphocytes are poorly understood. We hypothesized that IRA B cells could reside in human palatine tonsils, which are a first line of defense from infection of the upper respiratory tract. In the present work, we used flow cytometry and confocal microscopy to identify and characterize human IRA (hIRA) B cells in tonsils. We show that CD19⁺CD20⁺GM-CSF⁺ B cells are present in the tonsils of all the subjects studied at a frequency ranging between ~0.2% and ~0.4% of the conventional CD19⁺CD20⁺GM-CSF⁻ B cells. These cells reside within the B cell follicles, are mostly IgM⁺IgD⁺, express CD5 and show phagocytic activity. Our results support a role for hIRA B cells in the effector immune response to infections in tonsils.

  17. Innate Response Activator (IRA B Cells Reside in Human Tonsils and Internalize Bacteria In Vitro.

    Directory of Open Access Journals (Sweden)

    Nico Chiappini

    Full Text Available Innate response activator (IRA B cells have been described in mice as a subset of B-1a B cells that produce granulocyte/macrophage colony-stimulating factor (GM-CSF and have been found in the spleen upon activation. In humans, identification, tissue localization and functionality of these lymphocytes are poorly understood. We hypothesized that IRA B cells could reside in human palatine tonsils, which are a first line of defense from infection of the upper respiratory tract. In the present work, we used flow cytometry and confocal microscopy to identify and characterize human IRA (hIRA B cells in tonsils. We show that CD19⁺CD20⁺GM-CSF⁺ B cells are present in the tonsils of all the subjects studied at a frequency ranging between ~0.2% and ~0.4% of the conventional CD19⁺CD20⁺GM-CSF⁻ B cells. These cells reside within the B cell follicles, are mostly IgM⁺IgD⁺, express CD5 and show phagocytic activity. Our results support a role for hIRA B cells in the effector immune response to infections in tonsils.

  18. Appearance of Human Plasma Cells Following Differentiation of Human B Cells in NOD/SCID Mouse Spleen

    OpenAIRE

    2003-01-01

    Relatively little is known for the differentiation and maturation process of human B cells to plasma cells. This is particularly important in reconstitution work involving transfer of autoantibodies. To address this issue, we transplanted human peripheral blood mononuclear cells (PBMC) directly into the spleen of irradiated NOD/SCID mice depleted of natural killer cell activity. Within 6 weeks, naïve B cells differentiated into memory B cells and, importantly, the numbers of human CD138+ plas...

  19. Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Shao-Qing Kuang

    Full Text Available The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL. We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

  20. Amplification of IL-21 signalling pathway through Bruton's tyrosine kinase in human B cell activation.

    Science.gov (United States)

    Wang, Sheau-Pey; Iwata, Shigeru; Nakayamada, Shingo; Niiro, Hiroaki; Jabbarzadeh-Tabrizi, Siamak; Kondo, Masahiro; Kubo, Satoshi; Yoshikawa, Maiko; Tanaka, Yoshiya

    2015-08-01

    B cells play an important role in the pathogenesis of autoimmune diseases. The role of Bruton's tyrosine kinase (Btk) in cytokine-induced human B cell differentiation and class-switch recombination remains incompletely defined. This study analysed the effect of Btk on human activated B cells. Purified B cells from healthy subjects were stimulated with B cell receptor (BCR) and other stimuli with or without a Btk inhibitor and gene expression was measured. The B cell line BJAB was used to assess Btk-associated signalling cascades. Phosphorylated Btk (p-Btk) in peripheral blood B cells obtained from 10 healthy subjects and 41 patients with RA was measured by flow cytometry and compared with patient backgrounds. IL-21 signalling, in concert with BCR, CD40 and BAFF signals, led to robust expression of differentiation- and class-switch DNA recombination-related genes and IgG production in human B cells, all of which were significantly suppressed by the Btk inhibitor. Although phosphorylation of STAT1 and STAT3 was induced by co-stimulation with IL-21, BCR and CD40, STAT1 phosphorylation in the nucleus, but not in the cytoplasm, was exclusively impaired by Btk blockade. High levels of p-Btk were noted in B cells of RA patients compared with controls and they correlated significantly with titres of RF among RF-positive patients. The findings elucidate a model in which Btk not only plays a fundamental role in the regulation of BCR signalling, but may also mediate crosstalk with cytokine signalling pathways through regulation of IL-21-induced phosphorylation of STAT1 in the nuclei of human B cells. Btk appears to have pathological relevance in RA. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Human BLyS facilitates engraftment of human PBL derived B cells in immunodeficient mice.

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    Madelyn R Schmidt

    Full Text Available The production of fully immunologically competent humanized mice engrafted with peripheral lymphocyte populations provides a model for in vivo testing of new vaccines, the durability of immunological memory and cancer therapies. This approach is limited, however, by the failure to efficiently engraft human B lymphocytes in immunodeficient mice. We hypothesized that this deficiency was due to the failure of the murine microenvironment to support human B cell survival. We report that while the human B lymphocyte survival factor, B lymphocyte stimulator (BLyS/BAFF enhances the survival of human B cells ex vivo, murine BLyS has no such protective effect. Although human B cells bound both human and murine BLyS, nuclear accumulation of NF-kappaB p52, an indication of the induction of a protective anti-apoptotic response, following stimulation with human BLyS was more robust than that induced with murine BLyS suggesting a fundamental disparity in BLyS receptor signaling. Efficient engraftment of both human B and T lymphocytes in NOD rag1(-/- Prf1(-/- immunodeficient mice treated with recombinant human BLyS is observed after adoptive transfer of human PBL relative to PBS treated controls. Human BLyS treated recipients had on average 40-fold higher levels of serum Ig than controls and mounted a de novo antibody response to the thymus-independent antigens in pneumovax vaccine. The data indicate that production of fully immunologically competent humanized mice from PBL can be markedly facilitated by providing human BLyS.

  2. Regulatory B cells and tolerance in transplantation: from animal models to human.

    Directory of Open Access Journals (Sweden)

    Melanie eChesneau

    2013-12-01

    Full Text Available Until recently, the role of B cells in transplantation was thought to be restricted to producing antibodies that have been clearly shown to be deleterious in the long term, but, in fact, B cells are also able to produce cytokine and to present antigen. Their role as regulatory cells in various pathological situations has also been highlighted, and their role in transplantation is beginning to emerge in animal, and also in human, models. This review summarizes the different studies in animals and humans that suggest a B-cell regulatory role in the transplant tolerance mechanisms.

  3. An atlas of B-cell clonal distribution in the human body.

    Science.gov (United States)

    Meng, Wenzhao; Zhang, Bochao; Schwartz, Gregory W; Rosenfeld, Aaron M; Ren, Daqiu; Thome, Joseph J C; Carpenter, Dustin J; Matsuoka, Nobuhide; Lerner, Harvey; Friedman, Amy L; Granot, Tomer; Farber, Donna L; Shlomchik, Mark J; Hershberg, Uri; Luning Prak, Eline T

    2017-09-01

    B-cell responses result in clonal expansion, and can occur in a variety of tissues. To define how B-cell clones are distributed in the body, we sequenced 933,427 B-cell clonal lineages and mapped them to eight different anatomic compartments in six human organ donors. We show that large B-cell clones partition into two broad networks-one spans the blood, bone marrow, spleen and lung, while the other is restricted to tissues within the gastrointestinal (GI) tract (jejunum, ileum and colon). Notably, GI tract clones display extensive sharing of sequence variants among different portions of the tract and have higher frequencies of somatic hypermutation, suggesting extensive and serial rounds of clonal expansion and selection. Our findings provide an anatomic atlas of B-cell clonal lineages, their properties and tissue connections. This resource serves as a foundation for studies of tissue-based immunity, including vaccine responses, infections, autoimmunity and cancer.

  4. Human Lyb-2 homolog CD72 is a marker for progenitor B-cell leukemias.

    Science.gov (United States)

    Schwarting, R; Castello, R; Moldenhauer, G; Pezzutto, A; von Hoegen, I; Ludwig, W D; Parnes, J R; Dörken, B

    1992-11-01

    S-HCL 2 is the prototype antibody of the recently defined CD72 cluster (human Lyb-2). Under nonreducing conditions, S-HCL 2 monoclonal antibody (mAb) precipitates a glycoprotein of 80-86 kDa. Under reducing conditions, a dimer of 43 and 39 kDa, with core proteins of 40 and 36 kDa, is precipitated. CD72 expression in normal and malignant tissues is different from expression of all other previously described human B-cell antigens. In peripheral blood and bone marrow, the antigen appears to be present on all B lymphocytes, with the exception of plasma cells. In tissue, immunohistochemical staining revealed positivity for all known B-cell compartments; however, pulpa macrophages of the spleen and von Kupffer cells exhibited distinct positivity for CD72 also. Among 83 malignant non-Hodgkin's lymphomas examined by immunohistochemistry (alkaline phosphatase anti-alkaline phosphatase technique), all 54 B-cell lymphomas, including precursor B-cell lymphomas, Burkitt's lymphomas, germinal center lymphomas, chronic lymphocytic leukemias, and hairy cell leukemias, were CD72 positive, but no T-cell lymphomas were. Flow cytometry study of more than 80 mainly acute leukemias (52 B-cell leukemias) showed reactivity with S-HCL 2 mAb over the full range of B-cell differentiation. In particular, very early B cells in cytoplasmic Ig (cIg)-negative, CD19-positive pre-pre-B-cell leukemias and hybrid leukemias (mixed myeloid and B-cell type) were consistently positive for CD72 on the cell surface. Therefore, CD72 may become an important marker for progenitor B-cell leukemias.

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

    Science.gov (United States)

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

    2016-03-01

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

  6. Differential Effects of Tacrolimus versus Sirolimus on the Proliferation, Activation and Differentiation of Human B Cells.

    Directory of Open Access Journals (Sweden)

    Opas Traitanon

    Full Text Available The direct effect of immunosuppressive drugs calcineurin inhibitor (Tacrolimus, TAC and mTOR inhibitor (Sirolimus, SRL on B cell activation, differentiation and proliferation is not well documented. Purified human B cells from healthy volunteers were stimulated through the B Cell Receptor with Anti-IgM + anti-CD40 + IL21 in the absence / presence of TAC or SRL. A variety of parameters of B cell activity including activation, differentiation, cytokine productions and proliferation were monitored by flow cytometry. SRL at clinically relevant concentrations (6 ng/ml profoundly inhibited CD19(+ B cell proliferation compared to controls whereas TAC at similar concentrations had a minimal effect. CD27(+ memory B cells were affected more by SRL than naïve CD27- B cells. SRL effectively blocked B cell differentiation into plasma cells (CD19(+CD138(+ and Blimp1(+/Pax5(low cells even at low dose (2 ng/ml, and totally eliminated them at 6 ng/ml. SRL decreased absolute B cell counts, but the residual responding cells acquired an activated phenotype (CD25(+/CD69(+ and increased the expression of HLA-DR. SRL-treated stimulated B cells on a per cell basis were able to enhance the proliferation of allogeneic CD4(+CD25(- T cells and induce a shift toward the Th1 phenotype. Thus, SRL and TAC have different effects on B lymphocytes. These data may provide insights into the clinical use of these two agents in recipients of solid organ transplants.

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

    Science.gov (United States)

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

    2016-10-01

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

  8. TGFβ activated kinase 1 (TAK1 at the crossroad of B cell receptor and Toll-like receptor 9 signaling pathways in human B cells.

    Directory of Open Access Journals (Sweden)

    Dániel Szili

    Full Text Available B cell development and activation are regulated by combined signals mediated by the B cell receptor (BCR, receptors for the B-cell activating factor of the tumor necrosis factor family (BAFF-R and the innate receptor, Toll-like receptor 9 (TLR9. However, the underlying mechanisms by which these signals cooperate in human B cells remain unclear. Our aim was to elucidate the key signaling molecules at the crossroads of BCR, BAFF-R and TLR9 mediated pathways and to follow the functional consequences of costimulation.Therefore we stimulated purified human B cells by combinations of anti-Ig, B-cell activating factor of the tumor necrosis factor family (BAFF and the TLR9 agonist, CpG oligodeoxynucleotide. Phosphorylation status of various signaling molecules, B cell proliferation, cytokine secretion, plasma blast generation and the frequency of IgG producing cells were investigated. We have found that BCR induced signals cooperate with BAFF-R- and TLR9-mediated signals at different levels of cell activation. BCR and BAFF- as well as TLR9 and BAFF-mediated signals cooperate at NFκB activation, while BCR and TLR9 synergistically costimulate mitogen activated protein kinases (MAPKs, ERK, JNK and p38. We show here for the first time that the MAP3K7 (TGF beta activated kinase, TAK1 is responsible for the synergistic costimulation of B cells by BCR and TLR9, resulting in an enhanced cell proliferation, plasma blast generation, cytokine and antibody production. Specific inhibitor of TAK1 as well as knocking down TAK1 by siRNA abrogates the synergistic signals. We conclude that TAK1 is a key regulator of receptor crosstalk between BCR and TLR9, thus plays a critical role in B cell development and activation.

  9. Analysis of human B cell response to recombinantLeishmaniaLPG3

    Institute of Scientific and Technical Information of China (English)

    Mostafa Haji Fatahaliha; Maryam Hosseini; Sanaz Rasolzadeh; Dariush Shane Bandi; Behzad Baradaran; Farhad Jadidi-Niaragh; Mehdi Yousefi

    2015-01-01

    Objective:To evaluate the capability of recombinant Leishmania LPG3 and its fragments in the activation of B cells.Methods:In the present study, human B cells were purified from peripheral blood of 10 adult healthy subjects using magnetic-activated cell sorting technique. Subsequently, purified B cells were treated with recombinant LPG3, and itsN-terminal and C-terminal fragments at different concentrations (2, 10 and 20 μg/mL). B cell activation was assessed through expression of CD69 molecule by flowcytometry and secretion of IL-6, TNF-αα and IL-10 cytokines via enzyme-linked immunosorbent assay following treatment with recombinant antigens.Results:Our results showed that while the recombinant LPG-3 could significantly increase the production of IL-6 and TNF-α (P<0.05) in B cells, it had no effect on the secretion of IL-10 by B cells.Conclusions: Our study indicated that recombinant LPG-3 and especially itsN-terminal fragment could stimulate B cell response as an important immune response component against leishmaniasis. Thus, it seems that it can be considered as an effective adjuvant in vaccine developments against leishmaniasis.

  10. Efficient induction of cross-presentating human B cell by transduction with human adenovirus type 7 vector.

    Science.gov (United States)

    Peng, Ying; Lai, Meimei; Lou, Yunyan; Liu, Yanqing; Wang, Huiyan; Zheng, Xiaoqun

    2016-01-01

    Although human autologous B cells represent a promising alternative to dendritic cells (DCs) for easy large-scale preparation, the naive human B cells are always poor at antigen presentation. The safe and effective usage record of human adenovirus type 7 (HAdV7) live vaccines makes it attractive as a promising vaccine vector candidate. To investigate whether HAdV7 vector could be used to induce the human B cells cross-presentation, in the present study, we constructed the E3-defective recombinant HAdV7 vector encoding green fluorescent protein (GFP) and carcinoembryonic antigen (CEA). We demonstrated that naive human B cells can efficiently be transduced, and that the MAPKs/NF-κB pathway can be activated by recombinant HAdV7. We proved that cytokine TNF-α, IL-6 and IL-10, surface molecule MHC class I and the CD86, antigen-processing machinery (APM) compounds ERp57, TAP-1, and TAP-2. were upregulated in HAdV7 transduced human B cells. We also found that CEA-specific IFNγ expression, degranulation, and in vitro and ex vivo cytotoxicities are induced in autologous CD8(+) T cells presensitized by HAd7CEA modified human B cells. Meanwhile, our evidences clearly show that Toll-like receptors 9 (TLR9) antagonist IRS 869 significantly eliminated most of the HAdV7 initiated B cell activation and CD8(+) T cells response, supporting the role and contribution of TLR9 signaling in HAdV7 induced human B cell cross-presentation. Besides a better understanding of the interactions between recombinant HAdV7 and human naive B cells, to our knowledge, the present study provides the first evidence to support the use of HAdV7-modified B cells as a vehicle for vaccines and immunotherapy.

  11. Appearance of Human Plasma Cells Following Differentiation of Human B Cells in NOD/SCID Mouse Spleen

    Directory of Open Access Journals (Sweden)

    Kentaro Kikuchi

    2003-01-01

    Full Text Available Relatively little is known for the differentiation and maturation process of human B cells to plasma cells. This is particularly important in reconstitution work involving transfer of autoantibodies. To address this issue, we transplanted human peripheral blood mononuclear cells (PBMC directly into the spleen of irradiated NOD/SCID mice depleted of natural killer cell activity. Within 6 weeks, naïve B cells differentiated into memory B cells and, importantly, the numbers of human CD138+ plasma cells in spleen increased by 100 fold after transplantation. Plasma cell numbers correlated with the detection of human IgM and IgG in serum, indicating that human B cells had differentiated into mature plasma cells in the murine spleen. In addition to CD19+ plasma cells, a distinct CD19- plasma cell population was detected, suggesting that downregulation of CD19 associated with maturation of plasma cells occurred. When purified human B cells were transplanted, those findings were not observed. Our results indicate that differentiation and maturation of human B cells and plasma cells can be investigated by transplantation of human PBMC into the spleen of NOD/SCID mice. The model will be useful for studying the differentiation of human B cells and generation of plasma cells.

  12. Direct phenotypical and functional dysregulation of primary human B cells by human immunodeficiency virus (HIV type 1 in vitro.

    Directory of Open Access Journals (Sweden)

    Ana Judith Perisé-Barrios

    Full Text Available BACKGROUND: Human immunodeficiency virus type 1 (HIV-1 induces a general dysregulation of immune system. Dysregulation of B cell compartment is generally thought to be induced by HIV-related immune activation and lymphopenia. However, a direct influence of HIV-1 particles on B cells was recently proposed as the third pathway of B cells dysregulation. METHODS/PRINCIPAL FINDINGS: We evaluated the direct and specific consequences of HIV-1 contact on activation, survival, proliferation and phenotype of primary B cells in vitro. Moreover, we examined expression of activation-induced cytidine deaminase (AID mRNA that is responsible for class switch recombination (CSR and somatic hypermutation (SHM. Here, we report that changes observed in cellular proliferation, phenotypes and activation of B cells could be caused by direct contact between HIV-1 particles and primary B cells in vitro. Finally, direct HIV-1-derived B cells activation led to the increase of AID mRNA expression and its subsequent CSR function was detected in vitro. CONCLUSION/SIGNIFICANCE: We showed that HIV-1 could directly induce primary B cells dysregulation triggering phenotypical and functional abilities of B cells in vitro that could explain in some extent early B-cell abnormalities in HIV disease.

  13. Heterogeneity of CD44 expression among human B-cell subpopulations.

    Science.gov (United States)

    Kremmidiotis, G; Ridings, J; Hicks, M; Beckman, I G; Bryson, G; Collins, R; Zola, H

    1998-03-01

    CD44 is a widely distributed cell surface glycoprotein that participates in a number of cellular adhesion and signal transduction processes. Germinal center B cells express very low levels of CD44, whereas their precursors and differentiation products express much higher levels. In immunofluorescence studies comparing 20 antibodies classified as being against the hematopoietic isoform of CD44, one antibody, A1G3, was unreactive with germinal center B cells, whereas the other antibodies showed low intensity but definite reactivity. Western blotting and sequential immunoprecipitation studies of lysates from density-separated lymphocyte fractions showed two bands that were differentially expressed and reacted differently with A1G3 compared with the other CD44 antibodies. These results suggest that germinal center B cells and non-germinal center B cells express different forms of CD44. Of 21 malignant B-cell populations examined, 5 showed reactivity with a "standard" CD44 reagent and significantly reduced reactivity with A1G3, while one sample showed the opposite pattern and the remainder were positive for both reagents. Of 10 cell lines studied, 5 were differentially stained by A1G3 and a standard CD44 antibody. PCR amplification of reverse transcribed mRNA from sorted human tonsil B-cell subpopulations and Southern blotting showed that B cells express a number of splice isoforms of CD44. These results demonstrate that B cells express multiple forms of CD44; both splice insert isoforms and variants distinguished by A1G3; the form of CD44 expressed depends on B-cell differentiation state.

  14. The role of the interleukin-10 subfamily members in immunoglobulin production by human B cells

    DEFF Research Database (Denmark)

    Hummelshoj, L; Ryder, L P; Poulsen, Lars K.

    2006-01-01

    Interleukin (IL)-10 has been shown to have various effects on B cells, including positively affecting the production of immunoglobulin A (IgA) and IgG. Several human IL-10-related molecules have been identified. These include IL-19, IL-20, IL-22, IL-24, IL-26, IL-28 and IL-29. To determine...... the effects of the IL-10 analogues on the class switch recombination in B cells, we analysed Ig production from naïve B cells stimulated with these cytokines in the presence of anti-CD40. None of the cytokines were found to induce Ig production by themselves in the presence of anti-CD40 Ab. However, all...... involved in the Ig regulation in B cells. However, some of the analogues might have regulatory effects on CSR induced by CD40-ligation in combination with IL-4 or TGF-beta....

  15. Human memory B cells originate from three distinct germinal center-dependent and -independent maturation pathways.

    Science.gov (United States)

    Berkowska, Magdalena A; Driessen, Gertjan J A; Bikos, Vasilis; Grosserichter-Wagener, Christina; Stamatopoulos, Kostas; Cerutti, Andrea; He, Bing; Biermann, Katharina; Lange, Johan F; van der Burg, Mirjam; van Dongen, Jacques J M; van Zelm, Menno C

    2011-08-25

    Multiple distinct memory B-cell subsets have been identified in humans, but it remains unclear how their phenotypic diversity corresponds to the type of responses from which they originate. Especially, the contribution of germinal center-independent responses in humans remains controversial. We defined 6 memory B-cell subsets based on their antigen-experienced phenotype and differential expression of CD27 and IgH isotypes. Molecular characterization of their replication history, Ig somatic hypermutation, and class-switch profiles demonstrated their origin from 3 different pathways. CD27⁻IgG⁺ and CD27⁺IgM⁺ B cells are derived from primary germinal center reactions, and CD27⁺IgA⁺ and CD27⁺IgG⁺ B cells are from consecutive germinal center responses (pathway 1). In contrast, natural effector and CD27⁻IgA⁺ memory B cells have limited proliferation and are also present in CD40L-deficient patients, reflecting a germinal center-independent origin. Natural effector cells at least in part originate from systemic responses in the splenic marginal zone (pathway 2). CD27⁻IgA⁺ cells share low replication history and dominant Igλ and IgA2 use with gut lamina propria IgA+ B cells, suggesting their common origin from local germinal center-independent responses (pathway 3). Our findings shed light on human germinal center-dependent and -independent B-cell memory formation and provide new opportunities to study these processes in immunologic diseases.

  16. Human B cell activating factor (BCAF): production by a human T cell tumor line.

    Science.gov (United States)

    Fevrier, M; Diu, A; Mollier, P; Abadie, A; Olive, D; Mawas, C; Theze, J

    1989-01-01

    In a previous study, we demonstrated that supernatants from human T cell clones stimulated by a pair of anti-CD2 monoclonal antibodies cause resting human B cells to become activated and to proliferate in the absence of any other signals. The activity responsible for these effects was shown to be different from already characterized lymphokines and in particular from IL-2 and IL-4, and was named B Cell Activating Factor or BCAF. In this paper, we describe the production of BCAF by a human T cell tumor line T687 after phorbol myristate acetate (PMA) stimulation; this production can be potentiated by phytohemagglutinin (PHA). We further show that the stimulatory phase can be separated from the secretory phase thereby avoiding contamination of BCAF-containing supernatant by PMA and PHA. Supernatants produced under these conditions do not contain either IL-4 or IFN but contain traces of lymphotoxin and 2 to 10 ng/ml of IL-2. The T687 cell line will allow us to obtain a large volume of supernatant for biochemical study and purification of the molecule(s) responsible for BCAF activity.

  17. Difference in CD22 molecules in human B cells and basophils

    OpenAIRE

    Toba, Ken; Hanawa, Haruo; Fuse, Ichiro; Sakaue, Minori; Watanabe, Kenichi; Uesugi, Yumiko; Higuchi, Wataru; Takahashi, Wataru; Aizawa, Yoshifusa; 鳥羽, 健

    2002-01-01

    Objective. CD22 is believed to be restricted to normal and neoplastic B cells. Human basophils were found to express CD22 molecules. Among the antibodies against CD22, Leu14, which recognized the ligand binding domain reacted to basophils, and B3 and 4KB128, which recognized the amino terminus side and carboxy terminus side of the ligand binding epitope, respectively, did not. To clarify the difference of CD22 antigenicity in human B cells and basophils, we investigated RNA sequence and struc...

  18. The Effect of Prolonged Treatment with Belimumab on B cells in Human SLE

    Science.gov (United States)

    Jacobi, Annett M; Huang, Weiqing; Wang, Tao; Freimuth, William; Sanz, Inaki; Furie, Richard; Mackay, Meggan; Aranow, Cynthia; Diamond, Betty; Davidson, Anne

    2010-01-01

    Objectives To understand the effects of prolonged BLyS inhibition in human SLE. Methods 17 SLE patients enrolled in a clinical trial of belimumab, a BLyS-specific inhibitor, plus standard of care therapy were studied. Phenotypic analysis of lymphocytes was performed using flow cytometry. Circulating antibody-secreting cells were enumerated using ELISpot assay. Serum was analyzed by ELISA using an antibody that recognizes products of the VH4-34 gene. Lymphocyte counts, Ig levels and anti-dsDNA antibody levels were available as part of the clinical trial analyses. Results Samples were collected at days 0, 84, 168, 365, 532 and >730. The total B cell number decreased from baseline starting between days 84–168. This was due to a decrease in naïve and transitional B cells. CD27+/IgD+memory B cells and plasmablasts decreased only after 532 days, whereas CD27+/IgD− memory B cells were not affected, and there were no changes in T cells. Serum IgM levels began to decline between days 84–168, but there were no changes in serum levels of IgG, IgG anti-DNA antibodies or VH4-34 antibodies during the study. SLE patients had more IgM-, IgG-, and autoantibody-producing B cells than normal controls at Day 0. There was only a modest decrease in the frequency of total IgM-producing but not IgG-producing cells at Days 365 and 532, consistent with the phenotypic and serologic data. Conclusions Our data confirm the dependence of newly formed B cells on BLyS for survival in humans. In contrast, memory B cells and plasma cells are less susceptible to selective BLyS inhibition. PMID:20039404

  19. The transcriptional program of a human B cell line in response to Myc

    Science.gov (United States)

    Schuhmacher, Marino; Kohlhuber, Franz; Hölzel, Michael; Kaiser, Carmen; Burtscher, Helmut; Jarsch, Michael; Bornkamm, Georg W.; Laux, Gerhard; Polack, Axel; Weidle, Ulrich H.; Eick, Dirk

    2001-01-01

    The proto-oncogene c-myc (myc) encodes a transcription factor (Myc) that promotes growth, proliferation and apoptosis. Myc has been suggested to induce these effects by induction/repression of downstream genes. Here we report the identification of potential Myc target genes in a human B cell line that grows and proliferates depending on conditional myc expression. Oligonucleotide microarrays were applied to identify downstream genes of Myc at the level of cytoplasmic mRNA. In addition, we identified potential Myc target genes in nuclear run-on experiments by changes in their transcription rate. The identified genes belong to gene classes whose products are involved in amino acid/protein synthesis, lipid metabolism, protein turnover/folding, nucleotide/DNA synthesis, transport, nucleolus function/RNA binding, transcription and splicing, oxidative stress and signal transduction. The identified targets support our current view that myc acts as a master gene for growth control and increases transcription of a large variety of genes. PMID:11139609

  20. A human follicular lymphoma B cell line hypermutates its functional immunoglobulin genes in vitro.

    Science.gov (United States)

    Wu, H; Pelkonen, E; Knuutila, S; Kaartinen, M

    1995-12-01

    The functional immunoglobulin (Ig) genes of B lymphocytes undergo somatic mutations during immune responses. These mutations modify the antigen binding site of the immunoglobulins, thereby enhancing the average affinity of the antibodies produced. The molecular mechanism underlying these B cell hypermutations remains unresolved, partly because it is difficult to grow normal B cells in long-term cell cultures and because there is no suitable transformed or malignant B cell line which generates mutations in its immunoglobulin genes in vitro. Here, we show that the recently established follicular lymphoma line HF-1.3.4 generates somatic hypermutations in vitro at a high frequency of 0.7 x 10(-6) mutations per base pair per generation in standard cell cultures (RPMI 1640 + 5% fetal calf serum). This shows for the first time that B cell hypermutation can occur without T cells or T cell factors. The mutation frequency increased approximately tenfold to 1 x 10(-5) mutations/base pair/generation with B cell-specific growth factors (interleukins-2 and -4 and three antibodies stimulatory to HF-1.3.4 cells). This HF-1.3.4 lymphoma line may help to elucidate the molecular mechanism of Ig gene hypermutation.

  1. The B Cell-Stimulatory Cytokines BLyS and APRIL Are Elevated in Human Periodontitis and Are Required for B Cell-Dependent Bone Loss in Experimental Murine Periodontitis.

    Science.gov (United States)

    Abe, Toshiharu; AlSarhan, Mohammed; Benakanakere, Manjunatha R; Maekawa, Tomoki; Kinane, Denis F; Cancro, Michael P; Korostoff, Jonathan M; Hajishengallis, George

    2015-08-15

    B-lineage cells (B lymphocytes and plasma cells) predominate in the inflammatory infiltrate of human chronic periodontitis. However, their role in disease pathogenesis and the factors responsible for their persistence in chronic lesions are poorly understood. In this regard, two cytokines of the TNF ligand superfamily, a proliferation-inducing ligand (APRIL) and B-lymphocyte stimulator (BLyS), are important for the survival, proliferation, and maturation of B cells. Thus, we hypothesized that APRIL and/or BLyS are upregulated in periodontitis and contribute to induction of periodontal bone loss. This hypothesis was addressed in both human and mouse experimental systems. We show that, relative to healthy controls, the expression of APRIL and BLyS mRNA and protein was upregulated in natural and experimental periodontitis in humans and mice, respectively. The elevated expression of these cytokines correlated with increased numbers of B cells/plasma cells in both species. Moreover, APRIL and BLyS partially colocalized with κ L chain-expressing B-lineage cells at the epithelial-connective tissue interface. Ligature-induced periodontitis resulted in significantly less bone loss in B cell-deficient mice compared with wild-type controls. Ab-mediated neutralization of APRIL or BLyS diminished the number of B cells in the gingival tissue and inhibited bone loss in wild-type, but not in B cell-deficient, mice. In conclusion, B cells and specific cytokines involved in their growth and differentiation contribute to periodontal bone loss. Moreover, APRIL and BLyS have been identified as potential therapeutic targets in periodontitis.

  2. Homing of human B cells to lymphoid organs and B-cell lymphoma engraftment are controlled by cell adhesion molecule JAM-C.

    Science.gov (United States)

    Doñate, Carmen; Ody, Christiane; McKee, Thomas; Ruault-Jungblut, Sylvie; Fischer, Nicolas; Ropraz, Patricia; Imhof, Beat A; Matthes, Thomas

    2013-01-15

    Junctional adhesion molecule C (JAM-C) is expressed by vascular endothelium and human but not mouse B lymphocytes. The level of JAM-C expression defines B-cell differentiation stages and allows the classification of marginal zone-derived (JAM-C-positive) and germinal center-derived (JAM-C-negative) B-cell lymphomas. In the present study, we investigated the role of JAM-C in homing of human B cells, using a xenogeneic nonobese diabetic/severe combined immunodeficient mouse model. Treatment with anti-JAM-C antibodies in short-term experiments reduced migration of normal and malignant JAM-C-expressing B cells to bone marrow, lymph nodes, and spleen. Blocking homing to the spleen is remarkable, as most other antiadhesion antibodies reduce homing of B cells only to bone marrow and lymph nodes. Long-term administration of anti-JAM-C antibodies prevented engraftment of JAM-Cpos lymphoma cells in bone marrow, spleen, and lymph nodes of mice. Plasmon resonance studies identified JAM-B as the major ligand for JAM-C, whereas homotypic JAM-C interactions remained at background levels. Accordingly, anti-JAM-C antibodies blocked adhesion of JAM-C-expressing B cells to their ligand JAM-B, and immunofluorescence analysis showed the expression of JAM-B on murine and human lymphatic endothelial cells. Targeting JAM-C could thus constitute a new therapeutic strategy to prevent lymphoma cells from reaching supportive microenvironments not only in the bone marrow and lymph nodes but also in the spleen.

  3. Specialized pro-resolving mediators (SPMs) inhibit human B-cell IgE production

    Science.gov (United States)

    Kim, Nina; Ramon, Sesquile; Thatcher, Thomas H.; Woeller, Collynn F.; Sime, Patricia J.; Phipps, Richard P.

    2015-01-01

    Specialized pro-resolving lipid mediators (SPMs) constitute a recently recognized class of bioactive molecules which promote the resolution of inflammation. We recently reported that the SPMs resolvin D1 (RvD1) and 17-hydroxydocosahexaenoic acid (17-HDHA) promote the differentiation of IgG-secreting B cells and enhance antibody-mediated immune responses. However, there is an important knowledge gap regarding whether or not SPMs regulate human B-cell IgE production, which is the key effector in diseases such as asthma and allergy. Therefore we investigated whether a panel of diverse SPMs influences B-cell IgE production. An important finding was that 17-HDHA and RvD1 inhibit IgE production by human B cells and suppress the differentiation of naïve B cells into IgE-secreting cells by specifically blocking epsilon germline transcription (εGLT). This effect is specific to human IgE, as the SPMs do not inhibit production of IgM and IgG and did not suppress other IL-4-upregulated genes. 17-HDHA and RvD1 act by stabilizing the transcriptional repressor Bcl-6, which competes with STAT6 for binding at the εGLT promoter. Overall, these new findings demonstrate that certain SPMs inhibit the differentiation of IgE-producing B cells, without being broadly immune-suppressive, representing a novel class of potential therapeutics for IgE-driven diseases such as asthma and allergy. PMID:26474728

  4. Expression of human leukocyte antigens in diffuse large B cell lymphomas

    NARCIS (Netherlands)

    Riemersma, Sietske Annette

    2006-01-01

    Diffuse large B cell lymphoma is the most common type of non-Hodgkin lymphoma of which 40% present at extra-nodal sites including immune privileged sites such as the testis and the central nervous system (CNS). Loss of Human Leucocyte Antigen (HLA) expression has been described in many different

  5. On chip electrofusion of single human B cells and mouse myeloma cells for efficient hybridoma generation

    NARCIS (Netherlands)

    Kemna, Evelien; Wolbers, F.; van den Berg, Albert; Vermes, I.

    2011-01-01

    This article describes the development and full characterization of a microfluidic chip for electrofusion of human peripheral blood B-cells and mouse myeloma (NS-1) cells to generate hybridomas. The chip consists of an array of 783 traps, with dimensions that were optimized to obtain a final cell

  6. B-cell directed therapies in antiphospholipid antibody syndrome--new directions based on murine and human data.

    Science.gov (United States)

    Khattri, Saakshi; Zandman-Goddard, Gisele; Peeva, Elena

    2012-08-01

    The increased awareness of the role of humoral immunophysiology in antiphospholipid syndrome (APS) has aroused interest in B cells as therapeutic targets in this disease. This paper reviews the literature on B cell directed therapies in human and experimental APS. The clinical data is limited to B cell depletion with rituximab and comprises case reports and case series. Murine studies include use of modulators of B cell function such as belimumab and abatacept. In both human and murine studies, B cell directed therapies appeared to have clinical and serologic beneficial effects including a decrease in the antiphospholipid antibody titers after treatment. Randomized controlled clinical trials are needed to determine whether B cell depletors and/or B cell modulators can be effective agents for treating patients with APS.

  7. Human B cells have an active phagocytic capability and undergo immune activation upon phagocytosis of Mycobacterium tuberculosis.

    Science.gov (United States)

    Zhu, Qi; Zhang, Min; Shi, Ming; Liu, Yang; Zhao, Qing; Wang, Wenjing; Zhang, Guangyun; Yang, Longxiu; Zhi, Jin; Zhang, Lin; Hu, Gengyao; Chen, Pin; Yang, Yining; Dai, Wen; Liu, Tingting; He, Ying; Feng, Guodong; Zhao, Gang

    2016-04-01

    The paradigm that B cells are nonphagocytic was taken for granted for a long time until phagocytic B cells were found in early vertebrate animals. Thereafter, limited evidence has shown that human B cells may also internalize bacteria. However, whether human B cells can actively phagocytose bacteria has been less extensively investigated; in particular, the mechanisms and significance of the phagocytosis require clarification. Here, we show that the human Raji B cell line can phagocytose both live and dead Mycobacterium tuberculosis (Mtb), and the phagocytosed Mtb in turn affects the immune functions of the B cells. After incubation of Raji cells with Mtb, our confocal microscopy, electron microscopy and flow cytometry data showed that Raji cells effectively engulfed Mtb as well as latex beads. The phagocytic rate was proportional to the incubation time and the amount of Mtb or beads added. Additionally, we found that normal human serum could enhance the ability of Raji cells to phagocytose Mtb, while heat-inactivated serum reversed this promoting effect. The phagocytic process of B cells could partially be inhibited by cytochalasin B, an actin inhibitor. Importantly, the phagocytosed Mtb could regulate B cell immune functions, such as stimulating IgM production and upregulating the expression of the antigen-presenting costimulatory molecules CD80 and CD86. Therefore, our results provide the first evidence that human B cells can phagocytose Mtb in an active manner that is independent of bacterial viability, and phagocytosed Mtb can in turn regulate the immune activation of B cells.

  8. Plasma cell alloantigen ENPP1 is expressed by a subset of human B cells with potential regulatory functions.

    Science.gov (United States)

    Yoon, Jeongheon; Wang, Hongsheng; Kim, Yong Chan; Yoshimoto, Momoko; Abbasi, Sadia; Morse Iii, Herbert C

    2016-09-01

    Plasma cell alloantigen 1 (PC1), also known as ENPP1 (ectonucleotide pyrophosphatase/phosphodiesterase 1), is an enzyme involved primarily in hydrolysis of adenosine triphosphate at the cell surface. Although the expression pattern of PC1 is relatively broad, its expression in B cells is found at significant levels only in terminally differentiated germinal center B cells, plasma cells and a subset of B-1a cells in mice. Here we describe studies designed to determine whether expression of PC1 might define novel populations of human B cells with similarities to mouse B cells. We found that PC1 is expressed in small populations of human B lineage cells in peripheral blood, cord blood, tonsils, bone marrow and pediatric peritoneal fluid, with the highest levels in plasma cells. The characteristics of human PC1(+) B cells differ from mouse peritoneal B-1a subsets and from features of the human CD20(+)CD27(+)CD43(+)CD70(-) B-cell subset proposed to be human B-1 cells. Expression of PC1 was greatly increased in B cells stimulated with the combination of CD40 ligand, interleukin (IL)-4 and IL-21. In addition, PC1(+) B cells activated CD4(+) T regulatory cells. ENPP1 thus defines a subset of human B cells that differs significantly from mouse peritoneal B-1a and proposed human B-1 cells.

  9. Early Growth Response-1 Plays a Non-redundant Role in the Differentiation of B Cells into Plasma Cells.

    Science.gov (United States)

    Oh, Yeon-Kyung; Jang, Eunkyeong; Paik, Doo-Jin; Youn, Jeehee

    2015-06-01

    Early growth response (Egr)-1 is a Cys2-His2-type zincfinger transcription factor. It has been shown to induce survival and proliferation of immature and mature B cells, respectively, but its role in the differentiation of B cells into plasma cells remains unclear. To examine the effects of Egr-1 deficiency on the activation of B cells, naive B cells from Egr1 (-/-) mice and their wild-type (WT) littermates were activated to proliferate and differentiate, and then assayed by FACS. Proportions of cells undergoing proliferation and apoptosis did not differ between Egr1 (-/-) and WT mice. However, Egr1 (-/-) B cells gave rise to fewer plasma cells than WT B cells. Consistently, Egr1 (-/-) mice produced significantly lower titer of antigen-specific IgG than their WT littermates upon immunization. Our results demonstrate that Egr-1 participates in the differentiation program of B cells into plasma cells, while it is dispensable for the proliferation and survival of mature B cells.

  10. The proapoptotic benzodiazepine Bz-423 affects the growth and survival of malignant B cells.

    Science.gov (United States)

    Boitano, Anthony; Ellman, Jonathan A; Glick, Gary D; Opipari, Anthony W

    2003-10-15

    Bz-423 is a novel proapoptotic 1,4-benzodiazepine that induces cell death via a superoxide signal. Previous work has shown that Bz-423 ameliorates disease in animal models of systemic lupus erythematosus that also have features of lymphoproliferative disease. Here we describe the effects of Bz-423 against a group of malignant B-cell lines derived from Burkitt's lymphoma. These experiments demonstrate that Bz-423 has cytotoxic activity against all B-cell lines tested, regardless of EBV status or Bcl-2 and Bcl-x(L) expression levels. In addition to its cytotoxic properties, we found that Bz-423 is also a potent antiproliferative agent that induces a G(1)-phase arrest independent of p53. Mechanistically, both the cytotoxicity and growth arrest are mediated by increased reactive oxygen species levels and appear independent of binding to the peripheral benzodiazepine receptor. This work further defines the biological activities of Bz-423 that are consistent with those of other compounds in clinical development for antineoplastic therapies.

  11. Human herpesvirus-8 infection leads to expansion of the preimmune/natural effector B cell compartment.

    Directory of Open Access Journals (Sweden)

    Silvia Della Bella

    Full Text Available BACKGROUND: Human herpesvirus-8 (HHV-8 is the etiological agent of Kaposi's sarcoma (KS and of some lymphoproliferative disorders of B cells. Most malignancies develop after long-lasting viral dormancy, and a preventing role for both humoral and cellular immune control is suggested by the high frequency of these pathologies in immunosuppressed patients. B cells, macrophages and dendritic cells of peripheral lymphoid organs and blood represent the major reservoir of HHV-8. Due to the dual role of B cells in HHV-8 infection, both as virus reservoir and as agents of humoral immune control, we analyzed the subset distribution and the functional state of peripheral blood B cells in HHV-8-infected individuals with and without cKS. METHODOLOGY/PRINCIPAL FINDINGS: Circulating B cells and their subsets were analyzed by 6-color flow cytometry in the following groups: 1- patients HHV-8 positive with classic KS (cKS (n = 47; 2- subjects HHV-8 positive and cKS negative (HSP (n = 10; 3- healthy controls, HHV-8 negative and cKS negative (HC (n = 43. The number of B cells belonging to the preimmune/natural effector compartment, including transitional, pre-naïve, naïve and MZ-like subsets, was significantly higher among HHV-8 positive subjects, with or without cKS, while was comparable to healthy controls in the antigen-experienced T-cell dependent compartment. The increased number of preimmune/natural effector B cells was associated with increased resistance to spontaneous apoptosis, while it did not correlate with HHV-8 viral load. CONCLUSIONS/SIGNIFICANCE: Our results indicate that long-lasting HHV-8 infection promotes an imbalance in peripheral B cell subsets, perturbing the equilibrium between earlier and later steps of maturation and activation processes. This observation may broaden our understanding of the complex interplay between viral and immune factors leading HHV-8-infected individuals to develop HHV-8-associated malignancies.

  12. Expression of Immunoglobulin Receptors with Distinctive Features Indicating Antigen Selection by Marginal Zone B Cells from Human Spleen

    Science.gov (United States)

    Colombo, Monica; Cutrona, Giovanna; Reverberi, Daniele; Bruno, Silvia; Ghiotto, Fabio; Tenca, Claudya; Stamatopoulos, Kostas; Hadzidimitriou, Anastasia; Ceccarelli, Jenny; Salvi, Sandra; Boccardo, Simona; Calevo, Maria Grazia; De Santanna, Amleto; Truini, Mauro; Fais, Franco; Ferrarini, Manlio

    2013-01-01

    Marginal zone (MZ) B cells, identified as surface (s)IgMhighsIgDlowCD23low/−CD21+CD38− B cells, were purified from human spleens, and the features of their V(D)J gene rearrangements were investigated and compared with those of germinal center (GC), follicular mantle (FM) and switched memory (SM) B cells. Most MZ B cells were CD27+ and exhibited somatic hypermutations (SHM), although to a lower extent than SM B cells. Moreover, among MZ B-cell rearrangements, recurrent sequences were observed, some of which displayed intraclonal diversification. The same diversifying sequences were detected in very low numbers in GC and FM B cells and only when a highly sensitive, gene-specific polymerase chain reaction was used. This result indicates that MZ B cells could expand and diversify in situ and also suggested the presence of a number of activation-induced cytidine deaminase (AID)-expressing B cells in the MZ. The notion of antigen-driven expansion/selection in situ is further supported by the VH CDR3 features of MZ B cells with highly conserved amino acids at specific positions and by the finding of shared (“stereotyped”) sequences in two different spleens. Collectively, the data are consistent with the notion that MZ B cells are a special subset selected by in situ antigenic stimuli. PMID:23877718

  13. NF-κB Regulates B-Cell-Derived Nerve Growth Factor Expression

    Institute of Scientific and Technical Information of China (English)

    Klaus Heese; Noriko Inoue; Tohru Sawada

    2006-01-01

    In the mammalian brain, four neurotrophins have been identified: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4/5 (NT-4/5). NGF exerts an important role in the development and functions of the central and peripheral nervous system. However, it has recently been documented that several types of immune cells, such as mast cells, lymphocytes, basophils and eosinophils, produce,store and release NGF. Accumulating preclinical and clinical data indicate that dysfunctions of NGF and the other neurotrophins may contribute to impaired immune responses and concentration of NGF frequently correlates with disease severity. Thus, the aim of this study was to elucidate the potential signaling mechanisms of cytokineneurotrophins interactions contributing to increased NGF levels. Our data show that the transcription factorNF-κB plays a pivotal role in regulating B-cell-derived NGF expression.

  14. Complement Receptor Type 1 Suppresses Human B Cell Functions in SLE Patients

    Directory of Open Access Journals (Sweden)

    Mariann Kremlitzka

    2016-01-01

    Full Text Available Complement receptors (CRs play an integral role in innate immunity and also function to initiate and shape the adaptive immune response. Our earlier results showed that complement receptor type 1 (CR1, CD35 is a potent inhibitor of the B cell receptor- (BCR- induced functions of human B lymphocytes. Here we show that this inhibition occurs already at the initial steps of B cell activation since ligation of CR1 reduces the BCR-induced phosphorylation of key signaling molecules such as Syk and mitogen activated protein kinases (MAPKs. Furthermore, our data give evidence that although B lymphocytes of active systemic lupus erythematosus (SLE patients express lower level of CR1, the inhibitory capacity of this complement receptor is still maintained and its ligand-induced clustering results in significant inhibition of the main B cell functions, similar to that found in the case of healthy individuals. Since we have found that reduced CR1 expression of SLE patients does not affect the inhibitory capacity of the receptor, our results further support the therapeutical potential of CD35 targeting the decrease of B cell activation and autoantibody production in autoimmune patients.

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

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    Eva Szymanska eMroczek

    2014-03-01

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

  16. B cell-derived transforming growth factor-β1 expression limits the induction phase of autoimmune neuroinflammation

    Science.gov (United States)

    Bjarnadóttir, Kristbjörg; Benkhoucha, Mahdia; Merkler, Doron; Weber, Martin S.; Payne, Natalie L.; Bernard, Claude C. A.; Molnarfi, Nicolas; Lalive, Patrice H.

    2016-01-01

    Studies in experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), have shown that regulatory B cells modulate the course of the disease via the production of suppressive cytokines. While data indicate a role for transforming growth factor (TGF)-β1 expression in regulatory B cell functions, this mechanism has not yet been tested in autoimmune neuroinflammation. Transgenic mice deficient for TGF-β1 expression in B cells (B–TGF-β1−/−) were tested in EAE induced by recombinant mouse myelin oligodendrocyte glycoprotein (rmMOG). In this model, B–TGF-β1−/− mice showed an earlier onset of neurologic impairment compared to their littermate controls. Exacerbated EAE susceptibility in B–TGF-β1−/− mice was associated with augmented CNS T helper (Th)1/17 responses. Moreover, selective B cell TGF-β1–deficiency increased the frequencies and activation of myeloid dendritic cells, potent professional antigen-presenting cells (APCs), suggesting that B cell-derived TGF-β1 can constrain Th1/17 responses through inhibition of APC activity. Collectively our data suggest that B cells can down-regulate the function of APCs, and in turn encephalitogenic Th1/17 responses, via TGF-β1, findings that may be relevant to B cell-targeted therapies. PMID:27708418

  17. The IL-15R alpha chain signals through association with Syk in human B cells.

    Science.gov (United States)

    Bulanova, E; Budagian, V; Pohl, T; Krause, H; Dürkop, H; Paus, R; Bulfone-Paus, S

    2001-12-01

    The alpha-chain of the IL-15R (IL-15Ralpha) serves as the specific, high-affinity receptor for IL-15. It is expressed by lymphoid and nonlymphoid cells, including B cell lymphoma lines. In this study, we have further explored IL-15Ralpha-mediated signaling in activated primary B cells and in Raji cells, a human B-lymphoblastoid cell line which expresses the IL-15Ralpha and IL-2Rgamma chains, but lacks the IL-2Rbeta chain. Stimulation of Raji cells with IL-15 induces their proliferation and rescues them from C2-ceramide-induced apoptosis. By immunoprecipitation and Western blotting, we show that treatment of Raji cells and activated primary B cells with IL-15 induces coprecipitation of Syk kinase with the IL-15Ralpha chain. Upon association, the activated Syk kinase phosphorylates the IL-15Ralpha chain as well as phospholipase Cgamma, which coprecipitates with Syk. Furthermore, transfection of Raji cells with stem-loop Syk antisense oligonucleotides prevents IL-15Ralpha and phospholipase Cgamma phosphorylation as well as the inhibition of apoptosis by IL-15. Mutation of a defined region of the intracellular signaling portion of IL-15Ralpha (Tyr227) abrogates both the IL-15Ralpha/Syk association and IL-15Ralpha phosphorylation. Taken together, this suggests that Syk kinase physically and functionally associates with the IL-15Ralpha chain in B cells and that Syk plays a key role in mediating IL-15-induced signal transduction, thus accounting for the distinct functional consequences of IL-15 vs IL-2 binding to B cells.

  18. Hepatocyte growth factor regulated tyrosine kinase substrate in the peripheral development and function of B-cells

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Takayuki [Department of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai Iino, Iwaki, Fukushima 970-8551 (Japan); Department of Microbiology and Immunology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Murata, Kazuko, E-mail: murata-k@iwakimu.ac.jp [Department of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai Iino, Iwaki, Fukushima 970-8551 (Japan); Murata, Ryo [Department of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai Iino, Iwaki, Fukushima 970-8551 (Japan); Sun, Shu-lan [Department of Microbiology and Immunology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Saito, Yutaro; Yamaga, Shuhei [Department of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai Iino, Iwaki, Fukushima 970-8551 (Japan); Tanaka, Nobuyuki; Tamai, Keiichi [Division of Immunology, Miyagi Cancer Research Institute, 47-1 Nodayama, Medeshima-Shiode, Natori 981-1293 (Japan); Moriya, Kunihiko [Department of Pediatrics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Kasai, Noriyuki [Institute for Animal Experimentation, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Sugamura, Kazuo [Division of Immunology, Miyagi Cancer Research Institute, 47-1 Nodayama, Medeshima-Shiode, Natori 981-1293 (Japan); Ishii, Naoto [Department of Microbiology and Immunology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan)

    2014-01-10

    Highlights: •ESCRT-0 protein regulates the development of peripheral B-cells. •BCR expression on cell surface should be controlled by the endosomal-sorting system. •Hrs plays important roles in responsiveness to Ag stimulation in B lymphocytes. -- Abstract: Hepatocyte growth factor (HGF)-regulated tyrosine kinase substrate (Hrs) is a vesicular sorting protein that functions as one of the endosomal-sorting proteins required for transport (ESCRT). Hrs, which binds to ubiquitinated proteins through its ubiquitin-interacting motif (UIM), contributes to the lysosomal transport and degradation of ubiquitinated membrane proteins. However, little is known about the relationship between B-cell functions and ESCRT proteins in vivo. Here we examined the immunological roles of Hrs in B-cell development and functions using B-cell-specific Hrs-deficient (Hrs{sup flox/flox};mb1{sup cre/+}:Hrs-cKO) mice, which were generated using a cre-LoxP recombination system. Hrs deficiency in B-cells significantly reduced T-cell-dependent antibody production in vivo and impaired the proliferation of B-cells treated in vitro with an anti-IgM monoclonal antibody but not with LPS. Although early development of B-cells in the bone marrow was normal in Hrs-cKO mice, there was a significant decrease in the number of the peripheral transitional B-cells and marginal zone B-cells in the spleen of Hrs-cKO mice. These results indicate that Hrs plays important roles during peripheral development and physiological functions of B lymphocytes.

  19. Cloning non-transformed sheep B cells.

    Science.gov (United States)

    Griebel, P J; Beskorwayne, T; Godson, D L; Popowych, Y; Hein, W

    2000-04-03

    The capacity to clone B cells and establish permanent B cell lines has greatly facilitated a wide variety of studies characterising the growth, differentiation, and gene expression of murine and human B cells. Similar investigations of B cell biology for other species have been severely restricted by an inability to culture or clone B cells. This is the first report of a method to clone non-transformed sheep B cells using a culture system based on murine CD154 and a combination of human gamma chain-common cytokines. Sheep Peyer's patch B cells were cultured for 120 days and then cloned by limiting dilution culture. The parental B cell culture contained both surface immunoglobulin (sIg)M(+) and sIgG1(+) B cells and both types of B cell were cloned. Clonality was confirmed by PCR analysis of Ig heavy chain (HC) and light chain (LC) expression and DNA sequencing of HC V genes. There was agreement between the PCR and flow cytometric analyses of HC isotype expression on the B cell clones but the available monoclonal antibodies specific for sheep lambda and kappa LC did not react with all clones. Soluble Ig was detected in the culture supernatant of sIgG1(+) clones but not sIgM(+) clones. The B cell clones remained dependent upon CD154 and gamma chain-common cytokine co-stimulation for sustained growth and maintained stable Ig expression. The cloning of non-transformed sheep B cells should provide a valuable tool for studying sheep B cell biology, establishing Ig HC- and LC-specific monoclonal antibodies, analysing the B cell Ig repertoire, and may be used to produce sheep monoclonal antibodies.

  20. Aberrant recombination and repair during immunoglobulin class switching in BRCA1-deficient human B cells

    DEFF Research Database (Denmark)

    Björkman, Andrea; Qvist, Per; Du, Likun

    2015-01-01

    machinery. A shift to the use of microhomology-based, alternative end-joining (A-EJ) and increased frequencies of intra-S region deletions as well as insertions of inverted S sequences were observed at the recombination junctions amplified from BRCA1-deficient human B cells. Furthermore, increased use...... underlying BRCA1’s function in maintaining genome stability and tumor suppression but may also point to a previously unrecognized role of BRCA1 in B-cell lymphomagenesis....... of long microhomologies was found at recombination junctions derived from E3 ubiquitin-protein ligase RNF168-deficient, Fanconi anemia group J protein (FACJ, BRIP1)-deficient, or DNA endonuclease RBBP8 (CtIP)-compromised cells, whereas an increased frequency of S-region inversions was observed in breast...

  1. CD27 expression in the human splenic marginal zone : the infant marginal zone is populated by naive B cells

    NARCIS (Netherlands)

    Zandvoort, A; Lodewijk, ME; de Boer, NK; Dammers, PM; Kroese, FGM; Timens, W

    2001-01-01

    The splenic marginal zone of adult humans contains B cells, of which most express CD27, an antigen only recently identified as a marker for somatically, mutated memory B cells. We investigated whether and to which extent the developing marginal zone in infants arid children is populated by either

  2. Altered distribution of peripheral blood memory B cells in humans chronically infected with Trypanosoma cruzi.

    Science.gov (United States)

    Fernández, Esteban R; Olivera, Gabriela C; Quebrada Palacio, Luz P; González, Mariela N; Hernandez-Vasquez, Yolanda; Sirena, Natalia María; Morán, María L; Ledesma Patiño, Oscar S; Postan, Miriam

    2014-01-01

    Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

  3. Altered distribution of peripheral blood memory B cells in humans chronically infected with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Esteban R Fernández

    Full Text Available Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

  4. Generation and selection of immunized Fab phage display library against human B cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    Yongmei Shen; Xiaochun Yang; Ningzheng Dong; Xiaofang Xie; Xia Bai; Yizhen Shi

    2007-01-01

    The approval of using monoclonal antibodies as a targeted therapy in the management of patients with B cell lymphoma has led to new treatment options for this group of patients. Production of monoclonal antibodies by the traditional hybridoma technology is costly, and the resulting murine antibodies often have the disadvantage of triggering human anti-mouse antibody (HAMA) response. Therefore recombinant Fab antibodies generated by the phage display technology can be a suitable alternative in managing B cell lymphoma. In this study, we extracted total RNA from spleen cells of BALB/c mice immunized with human B lymphoma cells, and used RT-PCR to amplify cDNAs coding for the K light chains and Fd fragments of heavy chains. After appropriate restriction digests, these cDNA fragments were successively inserted into the phagemid vector pComb3H-SS to construct an immunized Fab phage display library. The diversity of the constructed library was approximately 1.94×107. Following five rounds of biopanning, soluble Fab antibodies were produced from positive clones identified by ELISA. From eight positive clones, FabC06, FabC21, FabC43 and FabC59 were selected for sequence analysis. At the level of amino acid sequences, the variable heavy domains (VH) and variable light domains (VL) were found to share 88-92% and 89-94% homology with sequences coded by the corresponding murine germline genes respectively. Furthermore, reactivity with membrane proteins of the B cell lymphoma was demonstrated by immunohistochemistry and western blotting. These immunized Fab antibodies may provide a valuable tool for further study of B cell lymphoma and could also contribute to the improvement of disease therapy.

  5. Effects of insulin-like growth factor-1 on B-cell precursor acute lymphoblastic leukemia.

    Science.gov (United States)

    Yamada, Hiroyuki; Iijima, Kazutoshi; Tomita, Osamu; Taguchi, Tomoko; Miharu, Masashi; Kobayashi, Kenichiro; Okita, Hajime; Saito, Masahiro; Shimizu, Toshiaki; Kiyokawa, Nobutaka

    2013-01-01

    Insulin-like growth factor-1 (IGF-1) is known to be a major growth factor with effects on various cell types, including hematopoietic cells, as well as neoplasms, and is regulated by IGF-binding proteins (IGFBPs). In this study, we investigated the effects of IGF-1 on B-cell precursor acute lymphoblastic leukemia (BCP-ALL) cells. When the expression of IGF-1R in clinical samples of BCP-ALL was examined, five of thirty-two cases showed IGF-1R expression, whereas IGF-1R was expressed in most BCP-ALL cell lines. We observed that IGF-1 enhanced the proliferation of BCP-ALL cell lines that can be partially inhibited by IGFBP-1, -3, and -4, but not other IGFBPs. IGF-1 also partially inhibited dexamethasone-induced apoptosis, but not apoptosis mediated by VP-16 and irradiation. Interestingly, the proliferative effect of IGF-1 was partially blocked by inhibitors of MAPK and AKT, whereas the inhibition of dexamethasone-induced apoptosis was completely blocked by both inhibitors. Our data indicate that IGF-1 is involved in cell proliferation and apoptosis regulation in BCP-ALL cells. Since some BCP-ALL cases express IGF-1R, it appears to be a plausible target for prognostic evaluation and may represent a new therapeutic strategy.

  6. The interplay of IL-21 and BAFF in the formation and maintenance of human B cell memory

    Directory of Open Access Journals (Sweden)

    Jodi eKarnell

    2012-01-01

    Full Text Available To date, IL-21 stands out as the most influential cytokine for human B cell activation and differentiation. Indeed, when compared to other important B cell-tropic cytokines such as IL-2, IL-4, IL-6 and IL-10, IL-21 is clearly the most potent in terms of its ability to influence humoral immune responses in humans. IL-21 has wide reaching actions in determining how B cells will respond to co-stimulation ranging from induction of cell death upon BCR cross-linking to potent induction of class switch recombination and plasma cell differentiation when CD40 molecules are co-engaged. Another crucial B cell factor, exemplified in recent clinical trials, is BAFF/BLys. BAFF plays a critical role in the survival of human B cells and plasma blasts and influences B cell expansion and migration. Recent evidence has shown that IL-21 and BAFF can work in concert to promote and perhaps maintain humoral immunity in humans. Notably, BAFF has the unique ability to substitute for CD40L activities in regard to IL-21-costimulation and differentiation of a specific B cell subpopulation located in the human splenic marginal zone. However, and perhaps surprisingly, BAFF signals do not have the capability to override IL-21-driven cell death events when BCR is engaged. In stark contrast, anti-CD40 ligation of B cells co-activated with IL-21 and anti-IgM not only reverses this aforementioned activation-induced cell death, but transforms this death signal into one that drives plasma cell differentiation. Here we will discuss these two critical B cell factors, IL-21 and BAFF, and their distinct and complimentary effects on human B cell responses.

  7. B-Cells and the Use of Non-Human Primates for Evaluation of HIV Vaccine Candidates.

    Science.gov (United States)

    Demberg, Thorsten; Robert-Guroff, Marjorie

    2015-01-01

    The RV144 clinical trial in Thailand associated vaccine-induced antibodies with protective efficacy, leading to a focus in HIV vaccine research on protective antibody induction. This has necessitated greater understanding of B cell biology in humans as well as non-human primates (NHP), the principle animal model for pre-clinical HIV/SIV vaccine research. This review covers development and maturation of NHP B cells within the framework of current knowledge of human and murine B cells. Identification of many NHP B cell subpopulations is now possible, although consensus is lacking in some cases, and better distinction of some populations is still needed. Elucidation of mechanisms that control germinal center maintenance, selection of B cells into the memory cell pool, and differentiation of B cells into long-lived plasma cells remains critical for improving vaccine design. B cell dysfunction occurs during both HIV and SIV infection. Whether the processes leading to this impairment are identical in humans and NHP is not known. Uncovering the mechanisms involved could lead to improved treatment regimens. The SIV/NHP model effectively mimics HIV infection of people, but key differences between NHP and humans in antibody characteristics such as glycosylation and structure may lead to unexpected outcomes in pre-clinical studies. Important new areas for investigation include the role of B cell cytokines in the immune system and the impact of the microbiome on B cell development and maturation. Enhanced knowledge of B cells in NHP as well as humans should enable improved vaccine design, leading to induction of potent, long-lasting protective antibodies.

  8. Abortive lytic reactivation of KSHV in CBF1/CSL deficient human B cell lines.

    Directory of Open Access Journals (Sweden)

    Barbara A Scholz

    Full Text Available Since Kaposi's sarcoma associated herpesvirus (KSHV establishes a persistent infection in human B cells, B cells are a critical compartment for viral pathogenesis. RTA, the replication and transcription activator of KSHV, can either directly bind to DNA or use cellular DNA binding factors including CBF1/CSL as DNA adaptors. In addition, the viral factors LANA1 and vIRF4 are known to bind to CBF1/CSL and modulate RTA activity. To analyze the contribution of CBF1/CSL to reactivation in human B cells, we have successfully infected DG75 and DG75 CBF1/CSL knock-out cell lines with recombinant KSHV.219 and selected for viral maintenance by selective medium. Both lines maintained the virus irrespective of their CBF1/CSL status. Viral reactivation could be initiated in both B cell lines but viral genome replication was attenuated in CBF1/CSL deficient lines, which also failed to produce detectable levels of infectious virus. Induction of immediate early, early and late viral genes was impaired in CBF1/CSL deficient cells at multiple stages of the reactivation process but could be restored to wild-type levels by reintroduction of CBF1/CSL. To identify additional viral RTA target genes, which are directly controlled by CBF1/CSL, we analyzed promoters of a selected subset of viral genes. We show that the induction of the late viral genes ORF29a and ORF65 by RTA is strongly enhanced by CBF1/CSL. Orthologs of ORF29a in other herpesviruses are part of the terminase complex required for viral packaging. ORF65 encodes the small capsid protein essential for capsid shell assembly. Our study demonstrates for the first time that in human B cells viral replication can be initiated in the absence of CBF1/CSL but the reactivation process is severely attenuated at all stages and does not lead to virion production. Thus, CBF1/CSL acts as a global hub which is used by the virus to coordinate the lytic cascade.

  9. Human Plasmacytoid Dendritic Cells Display and Shed B Cell Maturation Antigen upon TLR Engagement.

    Science.gov (United States)

    Schuh, Elisabeth; Musumeci, Andrea; Thaler, Franziska S; Laurent, Sarah; Ellwart, Joachim W; Hohlfeld, Reinhard; Krug, Anne; Meinl, Edgar

    2017-04-15

    The BAFF-APRIL system is best known for its control of B cell homeostasis, and it is a target of therapeutic intervention in autoimmune diseases and lymphoma. By analyzing the expression of the three receptors of this system, B cell maturation Ag (BCMA), transmembrane activator and CAML interactor, and BAFF receptor, in sorted human immune cell subsets, we found that BCMA was transcribed in plasmacytoid dendritic cells (pDCs) in both blood and lymphoid tissue. Circulating human pDCs contained BCMA protein without displaying it on the cell surface. After engagement of TLR7/8 or TLR9, BCMA was detected also on the cell surface of pDCs. The display of BCMA on the surface of human pDCs was accompanied by release of soluble BCMA (sBCMA); inhibition of γ-secretase enhanced surface expression of BCMA and reduced the release of sBCMA by pDCs. In contrast with human pDCs, murine pDCs did not express BCMA, not even after TLR9 activation. In this study, we extend the spectrum of BCMA expression to human pDCs. sBCMA derived from pDCs might determine local availability of its high-affinity ligand APRIL, because sBCMA has been shown to function as an APRIL-specific decoy. Further, therapeutic trials targeting BCMA in patients with multiple myeloma should consider possible effects on pDCs. Copyright © 2017 by The American Association of Immunologists, Inc.

  10. Light chain editors of anti-DNA receptors in human B cells.

    Science.gov (United States)

    Kalinina, Olga; Wang, Yue; Sia, Kevin; Radic, Marko; Cazenave, Pierre-André; Weigert, Martin

    2014-02-10

    Receptor editing is a mechanism of self-tolerance used in newly generated B cells. The expressed heavy (H) or light (L) chain of an autoreactive receptor is replaced by upstream V genes which eliminate or modify autoreactivity. Editing of anti-DNA receptors has been characterized in anti-DNA transgenic mouse models including 3H9, 3H9/56R, and their revertant 3H9GL. Certain L chains, termed editors, rescue anti-DNA B cells by neutralizing or modifying DNA binding of the H chain. This editing mechanism acts on the natural H chain repertoire; endogenous H chains with anti-DNA features are expressed primarily in combination with editor L chains. We ask whether a similar set of L chains exists in the human repertoire, and if so, do they edit H chains with anti-DNA signatures? We compared the protein sequences of mouse editors to all human L chains and found several human L chains similar to mouse editors. These L chains diminish or veto anti-DNA binding when expressed with anti-DNA H chains. The human H chains expressed with these L chains also have relatively high arginine (Arg) content in the H chain complementarity determining region (H3), suggesting that receptor editing plays a role in establishing tolerance to DNA in humans.

  11. A Single Human Papillomavirus Vaccine Dose Improves B Cell Memory in Previously Infected Subjects

    Directory of Open Access Journals (Sweden)

    Erin M. Scherer

    2016-08-01

    Full Text Available Although licensed human papillomavirus (HPV vaccines are most efficacious in persons never infected with HPV, they also reduce infection and disease in previously infected subjects, indicating natural immunity is not entirely protective against HPV re-infection. The aim of this exploratory study was to examine the B cell memory elicited by HPV infection and evaluate whether vaccination merely boosts antibody (Ab levels in previously infected subjects or also improves the quality of B cell memory. Toward this end, the memory B cells (Bmem of five unvaccinated, HPV-seropositive subjects were isolated and characterized, and subject recall responses to a single HPV vaccine dose were analyzed. Vaccination boosted Ab levels 24- to 930-fold (median 77-fold and Bmem numbers 3- to 27-fold (median 6-fold. In addition, Abs cloned from naturally elicited Bmem were generally non-neutralizing, whereas all those isolated following vaccination were neutralizing. Moreover, Ab and plasmablast responses indicative of memory recall responses were only observed in two subjects. These results suggest HPV vaccination augments both the magnitude and quality of natural immunity and demonstrate that sexually active persons could also benefit from HPV vaccination. This study may have important public policy implications, especially for the older ‘catch-up’ group within the vaccine's target population.

  12. T-bet+ B cells are induced by human viral infections and dominate the HIV gp140 response

    Science.gov (United States)

    Knox, James J.; Buggert, Marcus; Kardava, Lela; Seaton, Kelly E.; Eller, Michael A.; Canaday, David H.; Robb, Merlin L.; Ostrowski, Mario A.; Slifka, Mark K.; Tomaras, Georgia D.; Moir, Susan; Moody, M. Anthony; Betts, Michael R.

    2017-01-01

    Humoral immunity is critical for viral control, but the identity and mechanisms regulating human antiviral B cells are unclear. Here, we characterized human B cells expressing T-bet and analyzed their dynamics during viral infections. T-bet+ B cells demonstrated an activated phenotype, a distinct transcriptional profile, and were enriched for expression of the antiviral immunoglobulin isotypes IgG1 and IgG3. T-bet+ B cells expanded following yellow fever virus and vaccinia virus vaccinations and also during early acute HIV infection. Viremic HIV-infected individuals maintained a large T-bet+ B cell population during chronic infection that was associated with increased serum and cell-associated IgG1 and IgG3 expression. The HIV gp140–specific B cell response was dominated by T-bet–expressing memory B cells, and we observed a concomitant biasing of gp140-specific serum immunoglobulin to the IgG1 isotype. These findings suggest that T-bet induction promotes antiviral immunoglobulin isotype switching and development of a distinct T-bet+ B cell subset that is maintained by viremia and coordinates the HIV Env–specific humoral response. PMID:28422752

  13. kappa+lambda+ dual receptor B cells are present in the human peripheral repertoire

    OpenAIRE

    1995-01-01

    It is a common notion that mature B lymphocytes express either kappa or lambda light (L) chains, although the mechanism that leads to such isotypic exclusion is still debated. We have investigated the extent of L chain isotypic exclusion in normal human peripheral blood B lymphocytes. By three-color staining with anti-CD19, anti-kappa, and anti-lambda antibodies we could estimate that 0.2-0.5% of peripheral blood B cells from healthy adults express both kappa and lambda on the cell surface. T...

  14. Primary B-cell deficiencies reveal a link between human IL-17-producing CD4 T-cell homeostasis and B-cell differentiation.

    Directory of Open Access Journals (Sweden)

    Rita R Barbosa

    Full Text Available IL-17 is a pro-inflammatory cytokine implicated in autoimmune and inflammatory conditions. The development/survival of IL-17-producing CD4 T cells (Th17 share critical cues with B-cell differentiation and the circulating follicular T helper subset was recently shown to be enriched in Th17 cells able to help B-cell differentiation. We investigated a putative link between Th17-cell homeostasis and B cells by studying the Th17-cell compartment in primary B-cell immunodeficiencies. Common Variable Immunodeficiency Disorders (CVID, defined by defects in B-cell differentiation into plasma and memory B cells, are frequently associated with autoimmune and inflammatory manifestations but we found no relationship between these and Th17-cell frequency. In fact, CVID patients showed a decrease in Th17-cell frequency in parallel with the expansion of activated non-differentiated B cells (CD21(lowCD38(low. Moreover, Congenital Agammaglobulinemia patients, lacking B cells due to impaired early B-cell development, had a severe reduction of circulating Th17 cells. Finally, we found a direct correlation in healthy individuals between circulating Th17-cell frequency and both switched-memory B cells and serum BAFF levels, a crucial cytokine for B-cell survival. Overall, our data support a relationship between Th17-cell homeostasis and B-cell maturation, with implications for the understanding of the pathogenesis of inflammatory/autoimmune diseases and the physiology of B-cell depleting therapies.

  15. Protein kinase CK2 is widely expressed in follicular, Burkitt and diffuse large B-cell lymphomas and propels malignant B-cell growth.

    Science.gov (United States)

    Pizzi, Marco; Piazza, Francesco; Agostinelli, Claudio; Fuligni, Fabio; Benvenuti, Pietro; Mandato, Elisa; Casellato, Alessandro; Rugge, Massimo; Semenzato, Gianpietro; Pileri, Stefano A

    2015-03-30

    Serine-threonine kinase CK2 is highly expressed and pivotal for survival and proliferation in multiple myeloma, chronic lymphocytic leukemia and mantle cell lymphoma. Here, we investigated the expression of α catalytic and β regulatory CK2 subunits by immunohistochemistry in 57 follicular (FL), 18 Burkitt (BL), 52 diffuse large B-cell (DLBCL) non-Hodgkin lymphomas (NHL) and in normal reactive follicles. In silico evaluation of available Gene Expression Profile (GEP) data sets from patients and Western blot (WB) analysis in NHL cell-lines were also performed. Moreover, the novel, clinical-grade, ATP-competitive CK2-inhibitor CX-4945 (Silmitasertib) was assayed on lymphoma cells. CK2 was detected in 98.4% of cases with a trend towards a stronger CK2α immunostain in BL compared to FL and DLBCL. No significant differences were observed between Germinal Center B (GCB) and non-GCB DLBCL types. GEP data and WB confirmed elevated CK2 mRNA and protein levels as well as active phosphorylation of specific targets in NHL cells. CX-4945 caused a dose-dependent growth-arresting effect on GCB, non-GCB DLBCL and BL cell-lines and it efficiently shut off phosphorylation of NF-κB RelA and CDC37 on CK2 target sites. Thus, CK2 is highly expressed and could represent a suitable therapeutic target in BL, FL and DLBCL NHL.

  16. Efficient Methods To Isolate Human Monoclonal Antibodies from Memory B Cells and Plasma Cells.

    Science.gov (United States)

    Corti, Davide; Lanzavecchia, Antonio

    2014-10-01

    In this article, we highlight the advantages of isolating human monoclonal antibodies from the human memory B cells and plasma cell repertoires by using high-throughput cellular screens. Memory B cells are immortalized with high efficiency using Epstein-Barr virus (EBV) in the presence of a toll-like receptor (TLR) agonist, while plasma cells are maintained in single-cell cultures by using interleukin 6 (IL-6) or stromal cells. In both cases, multiple parallel assays, including functional assays, can be used to identify rare cells that produce antibodies with unique properties. Using these methods, we have isolated potent and broadly neutralizing antibodies against a variety of viruses, in particular, a pan-influenza-A-neutralizing antibody and an antibody that neutralizes four different paramyxoviruses. Given the high throughput and the possibility of directly screening for function (rather than just binding), these methods are instrumental to implement a target-agnostic approach to identify the most effective antibodies and, consequently, the most promising targets for vaccine design. This approach is exemplified by the identification of unusually potent cytomegalovirus-neutralizing antibodies that led to the identification of the target, a pentameric complex that we are developing as a candidate vaccine.

  17. A methyl jasmonate derivative, J-7, induces apoptosis in human hepatocarcinoma Hep3B cells in vitro.

    Science.gov (United States)

    Park, Cheol; Jin, Cheng-Yun; Kim, Gi-Young; Cheong, JaeHun; Jung, Jee H; Yoo, Young Hyun; Choi, Yung Hyun

    2010-10-01

    The pro-apoptotic activity of J-7, a synthetic methyl jasmonate derivative, on the Hep3B human hepatocarcinoma cell line was investigated. Treatment of Hep3B cells with J-7 resulted in growth inhibition and the induction of apoptosis as measured by trypan blue-excluding cells, MTT assay, nuclear staining, DNA fragmentation, and flow cytometry analysis. The increased apoptotic events in Hep3B cells caused by J-7 were associated with the alteration in the ratio of Bax/Bcl-2 protein expression. J-7 treatment induced the expression of death receptor-related proteins such as death receptor 5, which triggered the activation of caspase-8 and the down-regulation of the whole Bid expression. In addition, the apoptosis induction by J-7 was correlated with the activation of caspase-9 and caspase-3, down-regulation IAP family proteins such as XIAP and cIAP-1, and concomitant degradation of poly (ADP-ribose) polymerase. However, the cytotoxic and apoptotic effects induced by J-7 were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, which demonstrates the important role that caspase-3 plays in the process. Furthermore, blocking the extracellular signal-regulated protein kinase and c-Jun N-terminal kinase pathways showed increased apoptosis and the activation of caspases in J-7-induced apoptosis. The results indicated that J-7 induces the apoptosis of Hep3B cells through a signaling cascade of death-receptor-mediated extrinsic as well as mitochondria-mediated intrinsic caspase pathways, which are associated with the activation of the mitogen-activated protein kinases signal pathway.

  18. Neuropilin-1 expression characterizes T follicular helper (Tfh) cells activated during B cell differentiation in human secondary lymphoid organs.

    Science.gov (United States)

    Renand, Amédée; Milpied, Pierre; Rossignol, Julien; Bruneau, Julie; Lemonnier, François; Dussiot, Michael; Coulon, Séverine; Hermine, Olivier

    2013-01-01

    T follicular helper (Tfh) cells play an essential role in the development of antigen-specific B cell immunity. Tfh cells regulate the differentiation and survival of activated B cells outside and inside germinal centers (GC) of secondary lymphoid organs. They act through cognate contacts with antigen-presenting B cells, but there is no current marker to specifically identify those Tfh cells which productively interact with B cells. Here we show that neuropilin 1 (Nrp1), a cell surface receptor, is selectively expressed by a subset of Tfh cells in human secondary lymphoid organs. Nrp1 expression on Tfh cells correlates with B cell differentiation in vivo and in vitro, is transient, and can be induced upon co-culture with autologous memory B cells in a cell contact-dependent manner. Comparative analysis of ex vivo Nrp1(+) and Nrp1(-) Tfh cells reveals gene expression modulation during activation. Finally, Nrp1 is expressed by malignant Tfh-like cells in a severe case of angioimmunoblastic T-cell lymphoma (AITL) associated with elevated terminal B cell differentiation. Thus, Nrp1 is a specific marker of Tfh cells cognate activation in humans, which may prove useful as a prognostic factor and a therapeutic target in neoplastic diseases associated with Tfh cells activity.

  19. Soluble mediators can replace helper T cells in the activation of resting B lymphocytes: evidence for a human B cell activating factor.

    Science.gov (United States)

    Diu, A; Février, M; Moreau, J L; Gougeon, M L; Abadie, A; Thèze, J

    1988-01-01

    We were interested in studying the participation of T cell-derived soluble factors in the early steps of B cell activation. Thus supernatants containing such factors were obtained following activation of human T cell clones and their effects on isolated B cells investigated. These supernatants induced activation, blastogenesis and proliferation of purified resting human B cells. Our results strongly suggest the existence of a B cell Activating Factor (BCAF) of apparent molecular weight (m.w.) of 12,000-15,000 daltons which acts directly on resting B cells and replaces helper T cells in B cell activation.

  20. Comprehensive microRNA profiling in B-cells of human centenarians by massively parallel sequencing

    Directory of Open Access Journals (Sweden)

    Gombar Saurabh

    2012-07-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are small, non-coding RNAs that regulate gene expression and play a critical role in development, homeostasis, and disease. Despite their demonstrated roles in age-associated pathologies, little is known about the role of miRNAs in human aging and longevity. Results We employed massively parallel sequencing technology to identify miRNAs expressed in B-cells from Ashkenazi Jewish centenarians, i.e., those living to a hundred and a human model of exceptional longevity, and younger controls without a family history of longevity. With data from 26.7 million reads comprising 9.4 × 108 bp from 3 centenarian and 3 control individuals, we discovered a total of 276 known miRNAs and 8 unknown miRNAs ranging several orders of magnitude in expression levels, a typical characteristics of saturated miRNA-sequencing. A total of 22 miRNAs were found to be significantly upregulated, with only 2 miRNAs downregulated, in centenarians as compared to controls. Gene Ontology analysis of the predicted and validated targets of the 24 differentially expressed miRNAs indicated enrichment of functional pathways involved in cell metabolism, cell cycle, cell signaling, and cell differentiation. A cross sectional expression analysis of the differentially expressed miRNAs in B-cells from Ashkenazi Jewish individuals between the 50th and 100th years of age indicated that expression levels of miR-363* declined significantly with age. Centenarians, however, maintained the youthful expression level. This result suggests that miR-363* may be a candidate longevity-associated miRNA. Conclusion Our comprehensive miRNA data provide a resource for further studies to identify genetic pathways associated with aging and longevity in humans.

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

    Energy Technology Data Exchange (ETDEWEB)

    Geldmeyer-Hilt, Kerstin, E-mail: kerstin.hilt@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Heine, Guido, E-mail: guido.heine@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Hartmann, Bjoern, E-mail: bjoern.hartmann@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Baumgrass, Ria, E-mail: baumgrass@drfz.de [Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Radbruch, Andreas, E-mail: radbruch@drfz.de [Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Worm, Margitta, E-mail: margitta.worm@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany)

    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.

  2. Effects of JS-K, a novel anti-cancer nitric oxide prodrug, on gene expression in human hepatoma Hep3B cells.

    Science.gov (United States)

    Dong, Ray; Wang, Xueqian; Wang, Huan; Liu, Zhengyun; Liu, Jie; Saavedra, Joseph E

    2017-04-01

    JS-K is a novel anticancer nitric oxide (NO) prodrug effective against a variety of cancer cells, including the inhibition of AM-1 hepatoma cell growth in rats. To further evaluate anticancer effects of JS-K, human hepatoma Hep3B cells were treated with JS-K and the compound control JS-43-126 at various concentrations (0-100μM) for 24h, and cytotoxicity was determined by the MTS assay. The compound control JS-43-126 was not cytotoxic to Hep3B cells at concentrations up to 100μM, while the LC50 for JS-K was about 10μM. To examine the molecular mechanisms of antitumor effects of JS-K, Hep3B cells were treated with 1-10μM of JS-K for 24h, and then subjected to gene expression analysis via real time RT-PCR and protein immunostain via confocal images. JS-K is a GST-α targeting NO prodrug, and decreased immunostaining for GST-α was associated with JS-K treatment. JS-K activated apoptosis pathways in Hep3B cells, including induction of caspase-3, caspase-9, Bax, TNF-α, and IL-1β, and immunostaining for caspase-3 was intensified. The expressions of thrombospondin-1 (TSP-1) and the tissue inhibitors of metalloproteinase-1 (TIMP-1) were increased by JS-K at both transcript and protein levels. JS-K treatment also increased the expression of differentiation-related genes CD14 and CD11b, and depressed the expression of c-myc in Hep3B cells. Thus, multiple molecular events appear to be associated with anticancer effects of JS-K in human hepatoma Hep3B cells, including activation of genes related to apoptosis and induction of genes involved in antiangiogenesis and tumor cell migration. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Dissecting the interface between signaling and transcriptional regulation in human B cells

    DEFF Research Database (Denmark)

    Wang, Kai; Alvarez, Mariano J; Bisikirska, Brygida C

    2009-01-01

    A key role of signal transduction pathways is to control transcriptional programs in the nucleus as a function of signals received by the cell via complex post-translational modification cascades. This determines cell-context specific responses to environmental stimuli. Given the difficulty...... of quantitating protein concentration and post-translational modifications, signaling pathway studies are still for the most part conducted one interaction at the time. Thus, genome-wide, cell-context specific dissection of signaling pathways is still an open challenge in molecular systems biology....... In this manuscript we extend the MINDy algorithm for the identification of posttranslational modulators of transcription factor activity, to produce a first genome-wide map of the interface between signaling and transcriptional regulatory programs in human B cells. We show that the serine-threonine kinase STK38...

  4. Diffuse Large B-Cell Lymphoma in Human T-Lymphotropic Virus Type 1 Carriers

    Directory of Open Access Journals (Sweden)

    Brady E. Beltran

    2012-01-01

    Full Text Available We describe the clinical and pathological characteristics of seven patients who were human T-lymphotropic virus type 1 (HTLV-1 carriers and had a pathological diagnosis of de novo diffuse large B-cell lymphoma. Interestingly, three of our cases showed positive expression of Epstein-Barr-virus, (EBV- encoded RNA within the tumor cells indicating a possible interaction between these two viruses. Furthermore, our three EBV-positive cases presented with similar clinical characteristics such as early clinical stage and low-risk indices. To the best of our knowledge, this is the first case series describing the characteristics of HTLV-1-positive DLBCL patients. The potential relationship between HTLV-1 and EBV should be further explored.

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

    DEFF Research Database (Denmark)

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

    In order to improve insights into the B-cell biology and thereby B-cell myelomagenesis we have established a MSCNET standard for multiparametric flow cytometry (MFC) and cell sorting (FACS) for subsequent genetic analysis. The material analysed was fresh tonsils, blood and bone marrow. The method...... included homogenization, isolation of mononuclear cells, MFC and FACS sorting using multicolour fluorescence single tube panels.of antibodies against surface molecules as CD10/20/27/38/45, supplemented with tissue related antibodies. Isolated B-cell subpopulations were evaluated by morphological inspection...... and single gene expression analysis (qRT-PCR) for transcription factors as well as global gene expression profiling (GEP; GeneChip Human Exon 1.0 ST Array). For example for tonsils, based on the immunophenotypic presentation (including CD3/44/CXCR4 in the panel), B-cell subsets were identified and sorted...

  6. CD40L-Tri, a novel formulation of recombinant human CD40L that effectively activates B cells.

    Science.gov (United States)

    Naito, Masayasu; Hainz, Ursula; Burkhardt, Ute E; Fu, Buyin; Ahove, Deborah; Stevenson, Kristen E; Rajasagi, Mohini; Zhu, Baogong; Alonso, Anselmo; Witten, Elizabeth; Matsuoka, Ken-Ichi; Neuberg, Donna; Duke-Cohan, Jonathan S; Wu, Catherine J; Freeman, Gordon J

    2013-02-01

    CD40L has a well-established role in enhancing the immunostimulatory capacity of normal and malignant B cells, but a formulation suitable for clinical use has not been widely available. Like other TNF family members, in vivo and in vitro activity of CD40L requires a homotrimeric configuration, and growing evidence suggests that bioactivity depends on higher-order clustering of CD40. We generated a novel formulation of human recombinant CD40L (CD40L-Tri) in which the CD40L extracellular domain and a trimerization motif are connected by a long flexible peptide linker. We demonstrate that CD40L-Tri significantly expands normal CD19+ B cells by over 20- to 30-fold over 14 days and induces B cells to become highly immunostimulatory antigen-presenting cells (APCs). Consistent with these results, CD40L-Tri-activated B cells could effectively stimulate antigen-specific T responses (against the influenza M1 peptide) from normal volunteers. In addition, CD40L-Tri could induce malignant B cells to become effective APCs, such that tumor-directed immune responses could be probed. Together, our studies demonstrate the potent immune-stimulatory effects of CD40L-Tri on B cells that enable their expansion of antigen-specific human T cells. The potent bioactivity of CD40L-Tri is related to its ability to self-multimerize, which may be facilitated by its long peptide linker.

  7. Microbial Translocation and B Cell Dysfunction in Human Immunodeficiency Virus Disease

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    2012-01-01

    Full Text Available The gut mucosal barrier disrupted in HIV disease, resulting in increased systemic exposure to microbial products such as Lipo Polys Accharide (LPS. The association of enhanced microbial translocation and B cell dysfunction in HIV disease is not fully understood. High dose and short term exposure of microbial Toll-Like Receptor (TLR agonists were used as vaccine adjuvants, however, low dose and long term exposure of TLR agonists could be harmful. The characteristics of B cell dysfunction in HIV disease included B cell, especially memory B cell depletion, enhanced levels of autoimmune antibodies and impaired vaccine or antigen responsiveness. This review discusses and explores the possibility of the effect of microbial translocation on memory B cell depletion and impaired vaccine responses in HIV infection. By determining the mechanisms of B cell depletion and perturbations in HIV disease, it may be possible to design interventions that can improve immune responses to vaccines, reduce selected opportunistic infections and perhaps slow disease progression.

  8. Circulating Human Neonatal Naïve B cells are Deficient in CD73 Impairing Purine Salvage

    Directory of Open Access Journals (Sweden)

    Matthew Aaron Pettengill

    2016-03-01

    Full Text Available Background: Extracellular purines, in particular adenosine (Ado and adenosine-triphosphate (ATP, are critical immunoregulatory molecules. Expression and activity of purine ecto-enzymes on B cells in neonatal and adult blood may influence their function and has been incompletely characterized. Methods: Mononuclear cells were isolated from human neonatal (cord blood or adult (peripheral blood subjects and evaluated directly by flow cytometry for expression of purine ecto-enzymes. Additionally, B cell subsets were isolated from mononuclear cell fractions by fluorescence-activated cell sorting and gene transcription of purine ecto-enzymes (CD39 and CD73, adenosine deaminase (ADA1, purine nucleoside phosphorylase (PNP and select purine receptors (A2a were evaluated by reverse transcription followed by qRT-PCR. Immuno-magnetic-bead isolated naïve B cells were evaluated for enzymatic activity by incubation with radio-labeled purines followed by thin-layer chromatography, and subsequent B cell Ado acquisition was evaluated by liquid scintillation quantitation of radio-labeled Ado uptake.Results: Relative to their adult counterparts, neonatal circulating naïve B cells were markedly and selectively deficient in CD73 as observed by gene transcription, surface protein expression, and enzyme activity. Neonatal naïve B cell deficiency of CD73 expression significantly impaired their capacity to acquire extracellular purines for purine salvage.Conclusions: Human neonatal circulating naïve B cells are selectively deficient in CD73, impairing extracellular purine acquisition and potentially contributing to impaired B cell responses in early life.

  9. Uptake and presentation of myelin basic protein by normal human B cells.

    Directory of Open Access Journals (Sweden)

    Marie Klinge Brimnes

    Full Text Available B cells may play both pathogenic and protective roles in T-cell mediated autoimmune diseases such as multiple sclerosis (MS. These functions relate to the ability of B cells to bind and present antigens. Under serum-free conditions we observed that 3-4% of circulating B cells from healthy donors were capable of binding the MS-associated self-antigen myelin basic protein (MBP and of presenting the immunodominant peptide MBP85-99, as determined by staining with the mAb MK16 recognising the peptide presented by HLA-DR15-positive cells. In the presence of serum, however, the majority of B cells bound MBP in a complement-dependent manner, and almost half of the B cells became engaged in presentation of MBP85-99. Even though complement receptor 1 (CR1, CD35 and CR2 (CD21 both contributed to binding of MBP to B cells, only CR2 was important for the subsequent presentation of MBP85-99. A high proportion of MBP85-99 presenting B cells expressed CD27, and showed increased expression of CD86 compared to non-presenting B cells. MBP-pulsed B cells induced a low frequency of IL-10-producing CD4+ T cells in 3 out of 6 donors, indicating an immunoregulatory role of B cells presenting MBP-derived peptides. The mechanisms described here refute the general assumption that B-cell presentation of self-antigens requires uptake via specific B-cell receptors, and may be important for maintenance of tolerance as well as for driving T-cell responses in autoimmune diseases.

  10. Phosphatidylserine Outer Layer Translocation Is Implicated in IL-10 Secretion by Human Regulatory B Cells.

    Science.gov (United States)

    Audo, Rachel; Hua, Charlotte; Hahne, Michael; Combe, Bernard; Morel, Jacques; Daien, Claire I

    2017-01-01

    B cells can have a regulatory role, mainly mediated by interleukin 10 (IL-10). IL-10 producing B cells (B10 cells) cells remain to be better characterized. Annexin V binds phosphatidylserine (PS), which is externalized during apoptosis. Previous works suggested that B10 cells are apoptotic cells since they bind Annexin V. Others showed that Annexin V binding could also be expressed on viable B cells. We aimed to explore if PS exposure can be a marker of B10 cells and if PS exposure has a functional role on B cell IL-10 production in healthy subjects. We found that B10 cells were significantly more often Annexin V+ than IL-10 non-producing B cells. After CpG activation, Annexin V+ B cells differentiated more often into B10 cells than Annexin Vneg B cells. Cell death and early apoptosis were similar between Annexin V+ and Annexin Vneg B cells. PS blockage, using biotinylated AnV and glyburide, decreased B10 cell differentiation. This study showed that B10 cells have an increased PS exposure independently of any apoptotic state. B cells exposing PS differentiate more into B10 cells whereas PS blockage inhibits B10 cells generation. These results strongly suggest a link between PS exposure and B10 cells.

  11. IL-21 and CD40L synergistically promote plasma cell differentiation through upregulation of Blimp-1 in human B cells.

    Science.gov (United States)

    Ding, B Belinda; Bi, Enguang; Chen, Hongshan; Yu, J Jessica; Ye, B Hilda

    2013-02-15

    After undergoing Ig somatic hypermutation and Ag selection, germinal center (GC) B cells terminally differentiate into either memory or plasma cells (PCs). It is known that the CD40L and IL-21/STAT3 signaling pathways play critical roles in this process, yet it is unclear how the B cell transcription program interprets and integrates these two types of T cell-derived signals. In this study, we characterized the role of STAT3 in the GC-associated PC differentiation using purified human tonsillar GC B cells and a GC B cell-like cell line. When primary GC B cells were cultured under PC differentiation condition, STAT3 inhibition by AG490 prevented the transition from GC centrocytes to preplasmablast, suggesting that STAT3 is required for the initiation of PC development. In a GC B cell-like human B cell line, although IL-21 alone can induce low-level Blimp-1 expression, maximum Blimp-1 upregulation and optimal PC differentiation required both IL-21 and CD40L. CD40L, although having no effect on Blimp-1 as a single agent, greatly augmented the amplitude and duration of IL-21-triggered Jak-STAT3 signaling. In the human PRDM1 locus, CD40L treatment enhanced the ability of STAT3 to upregulate Blimp-1 by removing BCL6, a potent inhibitor of Blimp-1 expression, from a shared BCL6/STAT3 site in intron 3. Thus, IL-21 and CD40L collaborate through at least two distinct mechanisms to synergistically promote Blimp-1 activation and PC differentiation.

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

    DEFF Research Database (Denmark)

    Barington, T; Hougs, L; Juul, L

    1996-01-01

    of the cells originated from a common virgin B cell. Kinetic considerations implied that an extremely selected population of hypermutated memory B cells must have existed in these individuals before the first systemic immunization with the Ag. A possible role for the mucosal immune system in the priming...

  13. IL-17 Enhances Chemotaxis of Primary Human B Cells during Asthma.

    Science.gov (United States)

    Halwani, Rabih; Al-Kufaidy, Roua; Vazquez-Tello, Alejandro; Pureza, Mary Angeline; BaHammam, Ahmed S; Al-Jahdali, Hamdan; Alnassar, Sami A; Hamid, Qutayba; Al-Muhsen, Saleh

    2014-01-01

    IL-17 is a pro-inflammatory mediator that is believed to play a critical role in regulating tissue inflammation during asthma, COPD, as well as other inflammatory disorders. The level of expression of IL-17 has been shown to be upregulated in lung bronchial tissue of asthmatic patients. Several reports have provided further evidence that this cytokine could play a key role in enhancing the migration of inflammatory as well as structural cells of the bronchial lung tissue during asthma and COPD. B cell infiltration to sites of inflammation during inflammatory disorders such as bowel disease, asthma and COPD has been reported. Accordingly, in this study we hypothesized that IL-17 may exert a chemotactic effect on primary B cells during asthma. We observed that B cells from asthmatic patients expressed significantly higher levels of IL-17RA and IL-17RC, compared to those of healthy subjects. Using an in-vitro migration assay, B cells were shown to migrate towards both IL-17A and IL-17F. Interestingly, blocking IL-17A and IL-17F signaling using either anti-IL-17R antibodies or MAP kinase inhibitors prevented in vitro migration of B cell towards IL-17. These observations indicate a direct chemotactic effect of IL-17 cytokines on primary peripheral blood B cells with higher effect being on asthmatic B cells. These findings revealed a key role for IL-17 in enhancing the migration of B cells to the lung tissue during asthma or COPD.

  14. Whole-genome fingerprint of the DNA methylome during human B-cell differentiation

    Science.gov (United States)

    Kulis, Marta; Merkel, Angelika; Heath, Simon; Queirós, Ana C.; Schuyler, Ronald P.; Castellano, Giancarlo; Beekman, Renée; Raineri, Emanuele; Esteve, Anna; Clot, Guillem; Verdaguer-Dot, Nuria; Duran-Ferrer, Martí; Russiñol, Nuria; Vilarrasa-Blasi, Roser; Ecker, Simone; Pancaldi, Vera; Rico, Daniel; Agueda, Lidia; Blanc, Julie; Richardson, David; Clarke, Laura; Datta, Avik; Pascual, Marien; Agirre, Xabier; Prosper, Felipe; Alignani, Diego; Paiva, Bruno; Caron, Gersende; Fest, Thierry; Muench, Marcus O.; Fomin, Marina E.; Lee, Seung-Tae; Wiemels, Joseph L.; Valencia, Alfonso; Gut, Marta; Flicek, Paul; Stunnenberg, Hendrik G.; Siebert, Reiner; Küppers, Ralf; Gut, Ivo G.; Campo, Elías; Martín-Subero, José I.

    2017-01-01

    We analyzed the DNA methylome of ten subpopulations spanning the entire B-cell differentiation program by whole-genome bisulfite sequencing and high-density microarrays. We observed that non-CpG methylation disappeared upon B-cell commitment whereas CpG methylation changed extensively during B-cell maturation, showing an accumulative pattern and affecting around 30% of all measured CpGs. Early differentiation stages mainly displayed enhancer demethylation, which was associated with upregulation of key B-cell transcription factors and affected multiple genes involved in B-cell biology. Late differentiation stages, in contrast, showed extensive demethylation of heterochromatin and methylation gain of polycomb-repressed areas, and did not affect genes with apparent functional impact in B cells. This signature, which has been previously linked to aging and cancer, was particularly widespread in mature cells with extended life span. Comparing B-cell neoplasms with their normal counterparts, we identified that they frequently acquire methylation changes in regions undergoing dynamic methylation already during normal B-cell differentiation. PMID:26053498

  15. Disodium cromoglycate inhibits S mu-->S epsilon deletional switch recombination and IgE synthesis in human B cells

    Science.gov (United States)

    1994-01-01

    IgE synthesis requires interleukin 4 (IL-4) and a T-B cell interaction that involves the B cell antigen CD40 and its ligand expressed on activated T cells. IL-4 induces epsilon germline transcription whereas ligation of CD40 results in deletional S mu-->S epsilon switch recombination, expression of mature epsilon transcripts, and IgE synthesis and secretion. We demonstrate that disodium cromoglycate (DSCG), a drug commonly used for the prophylactic treatment of allergic disease, inhibits T cell-driven IgE synthesis by human B cells at concentrations readily achievable in the course of inhaled therapy for asthma. Inhibition of IgE synthesis by DSCG was not the result of drug toxicity because DSCG did not affect the viability of T and B cells or their proliferation to mitogens. DSCG did not interfere with CD40 ligand expression by T cells but clearly targeted the B cells because it inhibited IgE synthesis induced by anti-CD40 and IL-4 in populations of highly purified B cells. DSCG had no effect on the induction of epsilon germline transcripts by IL-4 but strongly inhibited CD40 mediated S mu-->S epsilon deletional switch recombination in IL-4- treated B cells as assayed by nested primer PCR. The effect of DSCG was not specific for CD40-mediated induction of IgE isotype switching because DSCG inhibited IgE synthesis as well as S mu-->S epsilon deletional switch recombination induced by hydrocortisone and IL-4 in B cells. Moreover, the effect of DSCG was not specific for IgE isotype switching because DSCG inhibited the synthesis of IgG4 by B cells sorted for lack of surface expression of IgG4 and stimulated with anti- CD40 and IL-4. DSCG caused only minimal inhibition (< 15%) of spontaneous IgE synthesis by lymphocytes from patients with the hyper- IgE syndrome and did not affect pokeweed mitogen-induced IgG and IgA synthesis by lymphocytes suggesting that it has little effect on B cells that have already undergone isotype switching. These results indicate that DSCG

  16. B cell receptor-induced growth arrest and apoptosis in WEHI-231 immature B lymphoma cells involve cyclic AMP and Epac proteins

    NARCIS (Netherlands)

    Grandoch, Maria; de Jesus, Maider Lopez; Weernink, Paschal A. Oude; Weber, Artur-Aron; Jakobs, Karl H.; Schmidt, Martina

    2009-01-01

    Signaling by the B cell antigen receptor (BCR) is essential for B lymphocyte homeostasis and immune function. In immature B cells, ligation of the BCR promotes growth arrest and apoptosis, and BCR-driven balancing between pro-apoptotic extracellular signal-regulated kinase 1 and 2 (ERK1/2) and antia

  17. The Epstein-Barr virus (EBV)-induced tumor suppressor microRNA MiR-34a is growth promoting in EBV-infected B cells.

    Science.gov (United States)

    Forte, Eleonora; Salinas, Raul E; Chang, Christina; Zhou, Ting; Linnstaedt, Sarah D; Gottwein, Eva; Jacobs, Cassandra; Jima, Dereje; Li, Qi-Jing; Dave, Sandeep S; Luftig, Micah A

    2012-06-01

    Epstein-Barr virus (EBV) infection of primary human B cells drives their indefinite proliferation into lymphoblastoid cell lines (LCLs). B cell immortalization depends on expression of viral latency genes, as well as the regulation of host genes. Given the important role of microRNAs (miRNAs) in regulating fundamental cellular processes, in this study, we assayed changes in host miRNA expression during primary B cell infection by EBV. We observed and validated dynamic changes in several miRNAs from early proliferation through immortalization; oncogenic miRNAs were induced, and tumor suppressor miRNAs were largely repressed. However, one miRNA described as a p53-targeted tumor suppressor, miR-34a, was strongly induced by EBV infection and expressed in many EBV and Kaposi's sarcoma-associated herpesvirus (KSHV)-infected lymphoma cell lines. EBV latent membrane protein 1 (LMP1) was sufficient to induce miR-34a requiring downstream NF-κB activation but independent of functional p53. Furthermore, overexpression of miR-34a was not toxic in several B lymphoma cell lines, and inhibition of miR-34a impaired the growth of EBV-transformed cells. This study identifies a progrowth role for a tumor-suppressive miRNA in oncogenic-virus-mediated transformation, highlighting the importance of studying miRNA function in different cellular contexts.

  18. Characterization of monoclonal antibodies against hepatitis C virus nonstructural protein 3: different antigenic determinants from human B cells.

    Science.gov (United States)

    Ou-Yang, P; Chiang, B L; Hwang, L H; Chen, Y G; Yang, P M; Chi, W K; Chen, P J; Chen, D S

    1999-04-01

    The nonstructural (NS3) region protein of hepatitis C virus (HCV) possesses major B-cell epitopes that induce antibodies after infection. To elucidate further the characteristics of these B cells and their role in the immune regulation of HCV infection, T9 (portion of NS3 region, amino acids [a.a.] 1188-1493)-specific monoclonal antibodies were derived and mapped for B-cell antigenic determinants with recombinant proteins. A total of 10 T9-specific hybridomas were generated and tested for B-cell antigenic determinants. To analyze the B-cell antigenic determinants, eight recombinant proteins including NS3-e (a.a. 1175-1334), NS3-a' (a.a. 1175-1250), NS3-a (a.a. 1251-1334), NS3-b (a.a. 1323-1412), NS3-c (a.a. 1407-1499), NS3-a/b (a.a. 1251-1412), NS3-bc (a.a. 1323-1499), and NS3-abc (a.a. 1251-1499) encoded by NS3-region internal clones were expressed and tested for immunoblotting. The data suggested IgG hybridomas recognized NS3-a, NS3-a', or NS3-b protein by immunoblotting. By contrast, the NS3-e protein bears the major antigenic determinant recognized by human sera. Half of the hybridomas were found to react with protein NS3-a', which is not a major B-cell antigenic determinant in humans. These data suggested that conformational epitopes in vivo may be important for B-cell recognition.

  19. Human adipose tissue-derived mesenchymal stem cells abrogate plasmablast formation and induce regulatory B cells independently of T helper cells.

    Science.gov (United States)

    Franquesa, M; Mensah, F K; Huizinga, R; Strini, T; Boon, L; Lombardo, E; DelaRosa, O; Laman, J D; Grinyó, J M; Weimar, W; Betjes, M G H; Baan, C C; Hoogduijn, M J

    2015-03-01

    Mesenchymal or stromal stem cells (MSC) interact with cells of the immune system in multiple ways. Modulation of the immune system by MSC is believed to be a therapeutic option for autoimmune disease and transplant rejection. In recent years, B cells have moved into the focus of the attention as targets for the treatment of immune disorders. Current B-cell targeting treatment is based on the indiscriminate depletion of B cells. The aim of this study was to examine whether human adipose tissue-derived MSC (ASC) interact with B cells to affect their proliferation, differentiation, and immune function. ASC supported the survival of quiescent B cells predominantly via contact-dependent mechanisms. Coculture of B cells with activated T helper cells led to proliferation and differentiation of B cells into CD19(+) CD27(high) CD38(high) antibody-producing plasmablasts. ASC inhibited the proliferation of B cells and this effect was dependent on the presence of T cells. In contrast, ASC directly targeted B-cell differentiation, independently of T cells. In the presence of ASC, plasmablast formation was reduced and IL-10-producing CD19(+) CD24(high) CD38(high) B cells, known as regulatory B cells, were induced. These results demonstrate that ASC affect B cell biology in vitro, suggesting that they can be a tool for the modulation of the B-cell response in immune disease.

  20. In silico prediction of B cell epitopes of the extracellular domain of insulin-like growth factor-1 receptor

    Directory of Open Access Journals (Sweden)

    Vahid Bayrami

    2016-12-01

    Full Text Available The insulin-like growth factor-1 receptor (IGF-1R is a transmembrane receptor with tyrosine kinase activity. The receptor plays a critical role in cancer. Using monoclonal antibodies (MAbs against the IGF-1R, typically blocks ligand binding and enhances down-regulation of the cell-surface IGF-1R. Some MAbs such as cixutumumab are under clinical trial investigation. Targeting multiple distinct epitopes on IGF-1R, might be an effective strategy to inhibit IGF-1R pathway in cancer. In this study, new linear B cell epitopes for the extracellular domains of IGF-1R were predicted by in silico methods using a combination of linear B cell epitope prediction web servers such as ABCpred, Bepired, BCPREDs, Bcepred and Elliprro. Moreover, Discotope, B-pred and PEPOP web server tools were employed to predict new conformational B cell epitopes. In contrast to previously reported epitopes from extracellular region of the IGF-1R, we predicted new linear P8: (RQPQDGYLYRHNYCSK and conformational Pc4: (HYYYAGVCVPACPPNTYRFE, Ppc6: (KMCPSTGKRENNESAPDNDT and Ppc20: (ANILSAESSDSEFMQEPSGFI epitopes. These epitopes are useful for further study as peptide antigens to actively immune host animals to develop new MAbs. Furthermore, the epitopes can be used in peptide-based cancer vaccines design.

  1. Human bronchial epithelial BEAS-2B cells, an appropriate in vitro model to study heavy metals induced carcinogenesis

    Science.gov (United States)

    Park, Youn-hee; Kim, Donghern; Dai, Jin; Zhang, Zhuo

    2015-01-01

    Occupational and environmental exposure to arsenic (III) and chromium VI (Cr(VI)) have been confirmed to cause lung cancer. Mechanisms of these metals-induced carcinogenesis are still under investigation. Selection of cell lines to be used is essential for the mechanistic studies. Human bronchial epithelial BEAS-2B cells are the cells to be utilized by most of scientists. However, due to p53 missense mutation (CCG → TCG) at codon 47 and the codon 72 polymorphism (CGC → CCC) in BEAS-2B cells, its usage has frequently been questioned. The present study has examined activity and expression of 53 and its downstream target protein p21 upon acute or chronic exposure of BEAS-2B cells to arsenic and Cr(VI). The results show that short-term exposure of BEAS-2B cells to arsenic or Cr(VI) was able to activate both p53 and p21. Chronic exposure of BEAS-2B cells to these two metals caused malignant cell transformation and tumorigenesis. In arsenic-transformed BEAS-2B cells reductions in p53 promoter activity, mRNA expression, and phosphorylation of p53 at Ser392 were observed, while the total p53 protein level remained the same compared to those in passage-matched parent ones. p21 promoter activity and expression were decreased in arsenic-transformed cells. Cr(VI)-transformed cells exhibit elevated p53 promoter activity, mRNA expression, and phosphorylation at Ser15, but reduced phosphorylation at Ser392 and total p53 protein level compared to passage-matched parent ones. p21 promoter activity and expression were elevated in Cr(VI)-transformed cells. These results demonstrate that p53 is able to respond to exposure of arsenic or Cr(VI), suggesting that BEAS-2B cells are an appropriate in vitro model to investigate arsenic or Cr(VI) induced lung cancer. PMID:26091798

  2. A human CD5+ B cell clone that secretes an idiotype-specific high affinity IgM monoclonal antibody.

    NARCIS (Netherlands)

    R.W.J. van der Heijden (Roger); H. Bunschoten; A.C. Hoek (Aad); J. van Es (Johan); M. Punter; A.D.M.E. Osterhaus (Albert); F.G.C.M. Uytdehaag (Fons)

    1991-01-01

    textabstractWe previously demonstrated the occurrence of a naturally arisen human anti-idiotypic B cell clone, that we transformed with EBV (EBV383). We show evidence that EBV383 not only expresses the CD5 surface Ag, but also contains the 2.7-kb mRNA transcript encoding this protein. In addition, w

  3. Uptake and presentation of myelin basic protein by normal human B cells

    DEFF Research Database (Denmark)

    Brimnes, Marie Klinge; Hansen, Bjarke Endel; Nielsen, Leif Kofoed

    2014-01-01

    B cells may play both pathogenic and protective roles in T-cell mediated autoimmune diseases such as multiple sclerosis (MS). These functions relate to the ability of B cells to bind and present antigens. Under serum-free conditions we observed that 3-4% of circulating B cells from healthy donors...... were capable of binding the MS-associated self-antigen myelin basic protein (MBP) and of presenting the immunodominant peptide MBP85-99, as determined by staining with the mAb MK16 recognising the peptide presented by HLA-DR15-positive cells. In the presence of serum, however, the majority of B cells...... bound MBP in a complement-dependent manner, and almost half of the B cells became engaged in presentation of MBP85-99. Even though complement receptor 1 (CR1, CD35) and CR2 (CD21) both contributed to binding of MBP to B cells, only CR2 was important for the subsequent presentation of MBP85-99. A high...

  4. Conserved B-cell epitopes among human bocavirus species indicate potential diagnostic targets.

    Directory of Open Access Journals (Sweden)

    Zhuo Zhou

    Full Text Available BACKGROUND: Human bocavirus species 1-4 (HBoV1-4 have been associated with respiratory and enteric infections in children. However, the immunological mechanisms in response to HBoV infections are not fully understood. Though previous studies have shown cross-reactivities between HBoV species, the epitopes responsible for this phenomenon remain unknown. In this study, we used genomic and immunologic approaches to identify the reactive epitopes conserved across multiple HBoV species and explored their potential as the basis of a novel diagnostic test for HBoVs. METHODOLOGY/PRINCIPAL FINDINGS: We generated HBoV1-3 VP2 gene fragment phage display libraries (GFPDLs and used these libraries to analyze mouse antisera against VP2 protein of HBoV1, 2, and 3, and human sera positive for HBoVs. Using this approach, we mapped four epitope clusters of HBoVs and identified two immunodominant peptides--P1 (¹MSDTDIQDQQPDTVDAPQNT²⁰, and P2 (¹⁶²EHAYPNASHPWDEDVMPDL¹⁸⁰--that are conserved among HBoV1-4. To confirm epitope immunogenicity, we immunized mice with the immunodominant P1 and P2 peptides identified in our screen and found that they elicited high titer antibodies in mice. These two antibodies could only recognize the VP2 of HBoV 1-4 in Western blot assays, rather than those of the two other parvoviruses human parvovirus B19 and human parvovirus 4 (PARV4. Based on our findings, we evaluated epitope-based peptide-IgM ELISAs as potential diagnostic tools for HBoVs IgM antibodies. We found that the P1+P2-IgM ELISA showed a higher sensitivity and specificity in HBoVs IgM detection than the assays using a single peptide. CONCLUSIONS/SIGNIFICANCE: The identification of the conserved B-cell epitopes among human bocavirus species contributes to our understanding of immunological cross-reactivities of HBoVs, and provides important insights for the development of HBoV diagnostic tools.

  5. B-cell exposure to self-antigen induces IL-10 producing B cells as well as IL-6- and TNF-α-producing B-cell subsets in healthy humans

    DEFF Research Database (Denmark)

    Langkjær, Anina; Kristensen, Birte; Hansen, Bjarke E

    2012-01-01

    of IL-10 and TGF-β, in addition to TNF-α and IL-6. Pulsing with foreign antigen, tetanus toxoid (TT), induced a Th1-response with minimal IL-10 production. After thyroglobulin-pulsing, 1.10±0.50% of B cells and 1.00±0.20% of CD4(+) T cells produced IL-10, compared to 0.29±0.19% of B cells (P=0.01) and 0...

  6. Human bronchial epithelial BEAS-2B cells, an appropriate in vitro model to study heavy metals induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youn-hee; Kim, Donghern; Dai, Jin; Zhang, Zhuo, E-mail: zhuo.zhang@uky.edu

    2015-09-15

    Occupational and environmental exposure to arsenic (III) and chromium VI (Cr(VI)) have been confirmed to cause lung cancer. Mechanisms of these metals carcinogenesis are still under investigation. Selection of cell lines to be used is essential for the studies. Human bronchial epithelial BEAS-2B cells are the cells to be utilized by most of scientists. However, due to p53 missense mutation (CCG → TCG) at codon 47 and the codon 72 polymorphism (CGC → CCC) in BEAS-2B cells, its usage has frequently been questioned. The present study has examined activity and expression of 53 and its downstream target protein p21 upon acute or chronic exposure of BEAS-2B cells to arsenic and Cr(VI). The results show that short-term exposure of BEAS-2B cells to arsenic or Cr(VI) was able to activate both p53 and p21. Chronic exposure of BEAS-2B cells to these two metals caused malignant cell transformation and tumorigenesis. In arsenic-transformed BEAS-2B cells reductions in p53 promoter activity, mRNA expression, and phosphorylation of p53 at Ser392 were observed, while the total p53 protein level remained the same compared to those in passage-matched parent ones. p21 promoter activity and expression were decreased in arsenic-transformed cells. Cr(VI)-transformed cells exhibit elevated p53 promoter activity, mRNA expression, and phosphorylation at Ser15, but reduced phosphorylation at Ser392 and total p53 protein level compared to passage-matched parent ones. p21 promoter activity and expression were elevated in Cr(VI)-transformed cells. These results demonstrate that p53 is able to respond to exposure of arsenic or Cr(VI), suggesting that BEAS-2B cells are an appropriate in vitro model to investigate arsenic or Cr(VI) induced lung cancer. - Highlights: • Short-term exposure of BEAS-2B cells to arsenic or Cr(VI) activates p53 and p21. • Chronic exposure of BEAS-2B cells to arsenic or Cr(VI) causes cell transformation and tumorigenesis. • Arsenic-transformed cells exhibit

  7. CD24(hi)CD27⁺ and plasmablast-like regulatory B cells in human chronic graft-versus-host disease.

    Science.gov (United States)

    de Masson, Adèle; Bouaziz, Jean-David; Le Buanec, Hélène; Robin, Marie; O'Meara, Alix; Parquet, Nathalie; Rybojad, Michel; Hau, Estelle; Monfort, Jean-Benoît; Branchtein, Mylène; Michonneau, David; Dessirier, Valérie; Sicre de Fontbrune, Flore; Bergeron, Anne; Itzykson, Raphaël; Dhédin, Nathalie; Bengoufa, Djaouida; Peffault de Latour, Régis; Xhaard, Aliénor; Bagot, Martine; Bensussan, Armand; Socié, Gérard

    2015-03-12

    Interleukin 10 (IL-10)-producing B cells (regulatory B cells [Bregs]) regulate autoimmunity in mice and humans, and a regulatory role of IL-10-producing plasma cells has been described in mice. Dysfunction of B cells that maintain homeostasis may play a role in the pathogenesis of chronic graft-versus-host disease (cGVHD) after allogeneic stem cell transplantation. Here, we found a relation between decreased Breg frequencies and cGVHD severity. An impaired ability of B cells to produce IL-10, possibly linked to poor signal transducer and activator of transcription 3 and extracellular signal-regulated kinase phosphorylation, was found in patients with active cGVHD. IL-10 production was not confined to a single B-cell subset, but enriched in both the CD24(hi)CD27(+) and CD27(hi)CD38(hi) plasmablast B-cell compartments. In vitro plasmablast differentiation increased the frequency of IL-10-producing B cells. We confirmed that allogeneic transplant recipients had an impaired reconstitution of the memory B-cell pool. cGVHD patients had less CD24(hi)CD27(+) B cells and IL-10-producing CD24(hi)CD27(+) B cells. Patients with cGVHD had increased plasmablast frequencies but decreased IL-10-producing plasmablasts. These results suggest a role of CD24(hi)CD27(+) B-cell and plasmablast-derived IL-10 in the regulation of human cGVHD.

  8. Naive and memory human B cells have distinct requirements for STAT3 activation to differentiate into antibody-secreting plasma cells.

    Science.gov (United States)

    Deenick, Elissa K; Avery, Danielle T; Chan, Anna; Berglund, Lucinda J; Ives, Megan L; Moens, Leen; Stoddard, Jennifer L; Bustamante, Jacinta; Boisson-Dupuis, Stephanie; Tsumura, Miyuki; Kobayashi, Masao; Arkwright, Peter D; Averbuch, Diana; Engelhard, Dan; Roesler, Joachim; Peake, Jane; Wong, Melanie; Adelstein, Stephen; Choo, Sharon; Smart, Joanne M; French, Martyn A; Fulcher, David A; Cook, Matthew C; Picard, Capucine; Durandy, Anne; Klein, Christoph; Holland, Steven M; Uzel, Gulbu; Casanova, Jean-Laurent; Ma, Cindy S; Tangye, Stuart G

    2013-11-18

    Long-lived antibody memory is mediated by the combined effects of long-lived plasma cells (PCs) and memory B cells generated in response to T cell-dependent antigens (Ags). IL-10 and IL-21 can activate multiple signaling pathways, including STAT1, STAT3, and STAT5; ERK; PI3K/Akt, and potently promote human B cell differentiation. We previously showed that loss-of-function mutations in STAT3, but not STAT1, abrogate IL-10- and IL-21-mediated differentiation of human naive B cells into plasmablasts. We report here that, in contrast to naive B cells, STAT3-deficient memory B cells responded to these STAT3-activating cytokines, differentiating into plasmablasts and secreting high levels of IgM, IgG, and IgA, as well as Ag-specific IgG. This was associated with the induction of the molecular machinery necessary for PC formation. Mutations in IL21R, however, abolished IL-21-induced responses of both naive and memory human B cells and compromised memory B cell formation in vivo. These findings reveal a key role for IL-21R/STAT3 signaling in regulating human B cell function. Furthermore, our results indicate that the threshold of STAT3 activation required for differentiation is lower in memory compared with naive B cells, thereby identifying an intrinsic difference in the mechanism underlying differentiation of naive versus memory B cells.

  9. Heterotransplantation of human leukemic B-cell, T-cell and null-cell lines in hamsters.

    Directory of Open Access Journals (Sweden)

    Hiraki,Shunkichi

    1979-02-01

    Full Text Available Human leukemic B-cell (BALL-1, T-cell (TALL-1 and null-cell (NALL-1 lines have been established from three patients with acute lymphoblastic leukemia (ALL. To study the heterotransplantability and in vivo growth characteristics, attempts were made to transplant these ALL cell lines into newborn Syrian hamsters treated with rabbit anti-hamster thymocyte serum. Intraperitoneal implantation of 1.8-3.5 x 10(7 cells gave rise to invasive tumors in all recipients after 15 to 41 days. In addition to a common in vivo feature of mesenteric and retroperitoneal tumors, BALL-1 line was characterized by infiltration of the skin, massive ascites and bone marrow invasion. TALL-1 cells infiltrated various organs including the lymph nodes, liver, gallbladder, spleen, bone marrow, central nervous system and eyes. NALL-1 line grew slowly, producing the least tumors, although there were distant metastases in the lungs. Tumor cells were detected in the blood of 2 of 3 BALL-1-bearing hamsters and in the blood of 4 of 5 TALL-1-bearing hamsters. Thus, these three ALL cell lines were found to exhibit a characteristic biological behavior in hamsters, which might be related to the different cell lineage.

  10. Intravascular large B cell lymphoma

    Directory of Open Access Journals (Sweden)

    Ricardo García-Muñoz

    2014-01-01

    Full Text Available Intravascular large B cell lymphoma (IVBCL is a rare type of extranodal large B cell lymphoma characterized by selective growth of lymphoma cells within the microvasculature. We present an illustrative case of intravascular B cell lymphoma suspected by the presence of a very small monoclonal B cell population identified by immunophenotype and polymerase chain reaction in bone marrow. The diagnosis was confirmed by skin biopsy.

  11. RUNX super-enhancer control through the Notch pathway by Epstein-Barr virus transcription factors regulates B cell growth.

    Science.gov (United States)

    Gunnell, Andrea; Webb, Helen M; Wood, C David; McClellan, Michael J; Wichaidit, Billy; Kempkes, Bettina; Jenner, Richard G; Osborne, Cameron; Farrell, Paul J; West, Michelle J

    2016-06-02

    In B cells infected by the cancer-associated Epstein-Barr virus (EBV), RUNX3 and RUNX1 transcription is manipulated to control cell growth. The EBV-encoded EBNA2 transcription factor (TF) activates RUNX3 transcription leading to RUNX3-mediated repression of the RUNX1 promoter and the relief of RUNX1-directed growth repression. We show that EBNA2 activates RUNX3 through a specific element within a -97 kb super-enhancer in a manner dependent on the expression of the Notch DNA-binding partner RBP-J. We also reveal that the EBV TFs EBNA3B and EBNA3C contribute to RUNX3 activation in EBV-infected cells by targeting the same element. Uncovering a counter-regulatory feed-forward step, we demonstrate EBNA2 activation of a RUNX1 super-enhancer (-139 to -250 kb) that results in low-level RUNX1 expression in cells refractory to RUNX1-mediated growth inhibition. EBNA2 activation of the RUNX1 super-enhancer is also dependent on RBP-J. Consistent with the context-dependent roles of EBNA3B and EBNA3C as activators or repressors, we find that these proteins negatively regulate the RUNX1 super-enhancer, curbing EBNA2 activation. Taken together our results reveal cell-type-specific exploitation of RUNX gene super-enhancers by multiple EBV TFs via the Notch pathway to fine tune RUNX3 and RUNX1 expression and manipulate B-cell growth.

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

    DEFF Research Database (Denmark)

    Barington, T; Hougs, L; Juul, L

    1996-01-01

    of Haemophilus influenzae type b coupled to tetanus toxoid. We combined affinity purification of circulating vaccine-induced Ab-secreting cells with PCR amplification of cDNA followed by cloning and sequencing. Forty-eight and 42 kappa VJ gene transcripts were analyzed from two adults, respectively. Both...... of the cells originated from a common virgin B cell. Kinetic considerations implied that an extremely selected population of hypermutated memory B cells must have existed in these individuals before the first systemic immunization with the Ag. A possible role for the mucosal immune system in the priming...

  13. Apoptosis in human germinal centre B cells by means of CC chemokine receptor 3 expression induced by interleukin-2 and interleukin-4

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiu-ping; XIE Luo-kun; ZHANG Li-jun; TAN Jin-quan

    2005-01-01

    Background CC chemokine receptor 3 (CCR3), expressed on some inflammatory cells, is a member of the chemokine receptor family. Its ligand is eotaxin/CCL11. In this research, we studied the expression and function of CCR3 induced by interleukin-2 (IL-2) and interleukin-4 (IL-4) on human germinal centre (GC) B cells.Methods Cells isolated from human tonsils were stimulated with IL-2 or/and IL-4 followed by bonding with eotaxin/CCL11. Flow cytometry was used to detect expression of CCR3 on GC B cells and apoptosis of GC B cells. Real time quantitative reverse transcription polymerase chain reaction and Northern blot assays were used to analyse the CCR3 mRNA expressed in the GC B cells. Chemotaxis and adhesion assays were used to determine the effect of eotaxin/CCL11 ligand bonded to CCR3 on GC B cells.Results There was no CCR3 expression on human freshly isolated GC B cells. The combination IL-2 and IL-4 could upregulate CCR3 mRNA and protein expression on GC B cells. Eotaxin could not induce GC B cell chemotaxis and adhesion but triggered apoptosis of GC B cells.Conclusion IL-2 and IL-4 together induced expression of CCR3 on GC B cells, and the receptor acted as a death receptor.

  14. Transplantation of human spleen into immunodeficient NOD/SCID IL2Rγ(null) mice generates humanized mice that improve functional B cell development.

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    Chung, Yun Shin; Son, Jin Kyung; Choi, Bongkum; Park, Jae Berm; Chang, Jun; Kim, Sung Joo

    2015-12-01

    We previously generated humanized TB34N mice that received human fetal thymus (T), bone tissue (B) and fetal liver-derived (FL)-CD34(+) cells (34) in immunodeficient, NOD/SCID IL2Rγ(null) (N) mice. Although humanized TB34N mice had excellent hematopoiesis, here, we sought to further improve this model by additional transplantation of human spleen tissue (S) as a secondary hematopoietic tissue (TBS34N). The human spleen grafts were enlarged and differentiated into a similar morphology of adult humans, including follicular lymphoid structures with T- and B-cells. The TBS34N mice mimicked mature human immune system (HIS): mature T- and B-cells and follicular dendritic cells; activated germinal center B-cells expressing CD71, BR3(+) cells, memory B-cells and activation-induced cytidine deaminase(+) B-cells; CD138(+) plasma cells were enriched in the mouse spleen. HBsAg-specific hIgG antibodies were secreted into the sera of all TBS34N mice upon immunization with HBsAg. Taken together, the humanized TBS34N mice improved mature HIS and achieved adaptive antibody responses.

  15. Protein kinase C inhibitor sotrastaurin selectively inhibits the growth of CD79 mutant diffuse large B-cell lymphomas.

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    Naylor, Tara L; Tang, Huaping; Ratsch, Boris A; Enns, Andreas; Loo, Alice; Chen, Liqing; Lenz, Peter; Waters, Nigel J; Schuler, Walter; Dörken, Bernd; Yao, Yung-Mae; Warmuth, Markus; Lenz, Georg; Stegmeier, Frank

    2011-04-01

    The activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) correlates with poor prognosis. The ABC subtype of DLBCL is associated with constitutive activation of the NF-κB pathway, and oncogenic lesions have been identified in its regulators, including CARD11/CARMA1 (caspase recruitment domain-containing protein 11), A20/TNFAIP3, and CD79A/B. In this study, we offer evidence of therapeutic potential for the selective PKC (protein kinase C) inhibitor sotrastaurin (STN) in preclinical models of DLBCL. A significant fraction of ABC DLBCL cell lines exhibited strong sensitivity to STN, and we found that the molecular nature of NF-κB pathway lesions predicted responsiveness. CD79A/B mutations correlated with STN sensitivity, whereas CARD11 mutations rendered ABC DLBCL cell lines insensitive. Growth inhibitory effects of PKC inhibition correlated with NF-κB pathway inhibition and were mediated by induction of G₁-phase cell-cycle arrest and/or cell death. We found that STN produced significant antitumor effects in a mouse xenograft model of CD79A/B-mutated DLBCL. Collectively, our findings offer a strong rationale for the clinical evaluation of STN in ABC DLBCL patients who harbor CD79 mutations also illustrating the necessity to stratify DLBCL patients according to their genetic abnormalities.

  16. Cell-Cycle-Dependent Reconfiguration of the DNA Methylome during Terminal Differentiation of Human B Cells into Plasma Cells.

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    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

    2015-11-03

    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.

  17. Cell-Cycle-Dependent Reconfiguration of the DNA Methylome during Terminal Differentiation of Human B Cells into Plasma Cells

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    Gersende Caron

    2015-11-01

    Full Text Available Molecular mechanisms underlying terminal differentiation of B cells into plasma cells are major determinants of adaptive immunity but remain only partially understood. Here we present the transcriptional and epigenomic landscapes of cell subsets arising from activation of human naive B cells and differentiation into plasmablasts. Cell proliferation of activated B cells was linked to a slight decrease in DNA methylation levels, but followed by a committal step in which an S phase-synchronized differentiation switch was associated with an extensive DNA demethylation and local acquisition of 5-hydroxymethylcytosine at enhancers and genes related to plasma cell identity. Downregulation of both TGF-β1/SMAD3 signaling and p53 pathway supported this final step, allowing the emergence of a CD23-negative subpopulation in transition from B cells to plasma cells. Remarkably, hydroxymethylation of PRDM1, a gene essential for plasma cell fate, was coupled to progression in S phase, revealing an intricate connection among cell cycle, DNA (hydroxymethylation, and cell fate determination.

  18. Importance of B cell co-stimulation in CD4(+) T cell differentiation: X-linked agammaglobulinaemia, a human model.

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    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-06-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.

  19. Monitoring the systemic human memory B cell compartment of melanoma patients for anti-tumor IgG antibodies.

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    Amy E Gilbert

    Full Text Available Melanoma, a potentially lethal skin cancer, is widely thought to be immunogenic in nature. While there has been much focus on T cell-mediated immune responses, limited knowledge exists on the role of mature B cells. We describe an approach, including a cell-based ELISA, to evaluate mature IgG antibody responses to melanoma from human peripheral blood B cells. We observed a significant increase in antibody responses from melanoma patients (n = 10 to primary and metastatic melanoma cells compared to healthy volunteers (n = 10 (P<0.0001. Interestingly, we detected a significant reduction in antibody responses to melanoma with advancing disease stage in our patient cohort (n = 21 (P<0.0001. Overall, 28% of melanoma patient-derived B cell cultures (n = 1,800 compared to 2% of cultures from healthy controls (n = 600 produced antibodies that recognized melanoma cells. Lastly, a patient-derived melanoma-specific monoclonal antibody was selected for further study. This antibody effectively killed melanoma cells in vitro via antibody-mediated cellular cytotoxicity. These data demonstrate the presence of a mature systemic B cell response in melanoma patients, which is reduced with disease progression, adding to previous reports of tumor-reactive antibodies in patient sera, and suggesting the merit of future work to elucidate the clinical relevance of activating humoral immune responses to cancer.

  20. Corruption of Human Follicular B-Lymphocyte Trafficking by a B-Cell Superantigen

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    Borhis, Gwenoline; Viau, Muriel; Badr, Gamal; Richard, Yolande; Zouali, Moncef

    2012-01-01

    Protein A (SpA) of Staphylococcus aureus is known to target the paratope of immunoglobulins expressing VH3 genes, and to delete marginal zone B cells and B-1a in vivo. We have discovered that SpA endows S. aureus with the potential to subvert B-cell trafficking in the host. We found that SpA, whose Fc-binding site has been inactivated, binds essentially to naïve B cells and induces a long-lasting decrease in CXCR4 expression and in B-cell chemotaxis to CXCL12. Competition experiments indicated that SpA does not interfere with binding of CXCR4 ligands and does not directly bind to CXCR4. This conclusion is strongly supported by the inability of SpA to modulate clathrin-mediated CXCR4 internalization, which contrasts with the potent effect of anti-immunoglobin M (IgM) antibodies. Microscopy and biochemical experiments confirmed that SpA binds to the surface IgM/IgD complex and induces its clathrin-dependent internalization. Concomitantly, the SpA-induced signaling leads to protein kinase C–dependent CXCR4 downmodulation, suggesting that SpA impairs the recycling of CXCR4, a postclathrin process that leads to either degradation into lysozomes or de novo expression at the cell surface. In addition to providing novel insight into disruption of B-cell trafficking by an infectious agent, our findings may have therapeutic implications. Because CXCR4 has been associated with cancer metastasis and with certain autoimmune diseases, SpA behaves as an evolutionary tailored highly specific, chemokine receptor inhibitor that may have value in addition to conventional cytotoxic therapy in patients with various malignancies and immune-mediated diseases. PMID:22367177

  1. Immune complex formation and in situ B-cell clonal expansion in human cerebral cavernous malformations.

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    Shi, Changbin; Shenkar, Robert; Kinloch, Andrew; Henderson, Scott G; Shaaya, Mark; Chong, Anita S; Clark, Marcus R; Awad, Issam A

    2014-07-15

    Cerebral cavernous malformations (CCMs) represent clusters of dilated vascular channels, predisposing to hemorrhagic stroke and seizures. They are associated with defective blood brain barrier, hemorrhages of different ages and a robust inflammatory cell infiltrate. We report for the first time evidence of co-localized IgG and complement membrane attack complexes in CCM lesions. CD4(+) and CD8(+) T-cells are aggregated with CD20(+) B-cells. And IgG repertoire analyses demonstrate in situ B-cell clonal expansion and antigen-driven affinity maturation in CCMs. These results suggest an organ-intrinsic adaptive immune response in CCMs that should be further characterized as a potential therapeutic target.

  2. Changes in CD44 expression during B cell differentiation in the human tonsil.

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    Kremmidiotis, G; Zola, H

    1995-04-01

    CD44 is a widely distributed cell surface glycoprotein that has been implicated in a number of cellular adhesion processes and signal transduction events. These functional capabilities qualify CD44 as a potential mediator of contact-signaling events underlying the process of antigen-dependent B cell differentiation in secondary lymphoid tissues. We postulated that changes in the expression of CD44 during B cell differentiation reflect the cells' changing requirements for this receptor. It has been reported that germinal center B cells are low to negative for CD44 expression, implying that the receptor is lost upon activation. Correlation of the expression of CD44 with surface immunoglobulin and a number of B cell differentiation markers revealed a trimodal expression pattern. High levels of CD44 are expressed on resting IgD+/IgM+ cells. The receptor is still expressed at the early activation stage defined by the expression of CD23. At the early blast stage, when the blast marker CD38 appears on the cell surface and IgD and CD23 disappear, CD44 is downregulated. The majority of CD38+/IgM+ blasts and CD38+/Ig- centroblasts are CD44 low/negative. The receptor is re-upregulated at the point of transition from the centroblast to the centrocyte level. Centrocytes expressing IgG or IgA comprise CD44high and CD44low fractions. IgG+ or IgA+ cells at the postgerminal center stage express high levels of CD44. The functional implications of this expression pattern are discussed.

  3. Protection against Pertussis in Humans Correlates to Elevated Serum Antibodies and Memory B Cells

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    Valentina Marcellini

    2017-09-01

    Full Text Available Pertussis is a respiratory infection caused by Bordetella pertussis that may be particularly severe and even lethal in the first months of life when infants are still too young to be vaccinated. Adults and adolescents experience mild symptoms and are the source of infection for neonates. Adoptive maternal immunity does not prevent pertussis in the neonate. We compared the specific immune response of mothers of neonates diagnosed with pertussis and mothers of control children. We show that women have pre-existing pertussis-specific antibodies and memory B cells and react against the infection with a recall response increasing the levels specific serum IgG, milk IgA, and the frequency of memory B cells of all isotypes. Thus, the maternal immune system is activated in response to pertussis and effectively prevents the disease indicating that the low levels of pre-formed serum antibodies are insufficient for protection. For this reason, memory B cells play a major role in the adult defense. The results of this study suggest that new strategies for vaccine design should aim at increasing long-lived plasma cells and their antibodies.

  4. Protection against Pertussis in Humans Correlates to Elevated Serum Antibodies and Memory B Cells

    Science.gov (United States)

    Marcellini, Valentina; Piano Mortari, Eva; Fedele, Giorgio; Gesualdo, Francesco; Pandolfi, Elisabetta; Midulla, Fabio; Leone, Pasqualina; Stefanelli, Paola; Tozzi, Alberto Eugenio; Carsetti, Rita; Agricola, E.

    2017-01-01

    Pertussis is a respiratory infection caused by Bordetella pertussis that may be particularly severe and even lethal in the first months of life when infants are still too young to be vaccinated. Adults and adolescents experience mild symptoms and are the source of infection for neonates. Adoptive maternal immunity does not prevent pertussis in the neonate. We compared the specific immune response of mothers of neonates diagnosed with pertussis and mothers of control children. We show that women have pre-existing pertussis-specific antibodies and memory B cells and react against the infection with a recall response increasing the levels specific serum IgG, milk IgA, and the frequency of memory B cells of all isotypes. Thus, the maternal immune system is activated in response to pertussis and effectively prevents the disease indicating that the low levels of pre-formed serum antibodies are insufficient for protection. For this reason, memory B cells play a major role in the adult defense. The results of this study suggest that new strategies for vaccine design should aim at increasing long-lived plasma cells and their antibodies. PMID:28966622

  5. Responses to recipient and donor B cells by genetically donor T cells from human haploidentical chimeras

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    Schiff, S.; Sampson, H.; Buckley, R.

    1986-03-01

    Following administration of haploidentical stem cells to infants with severe combined immunodeficiency (SCID), mature T cells of donor karyotype appear later in the recipient without causing graft-versus-host disease. To investigate the effect of the host environment on the responsiveness of these genetically donor T cells, blood B and T lymphocytes from 6 SCID recipients, their parental donors and unrelated controls were purified by double SRBC rosetting. T cells were stimulated by irradiated B cells at a 1:1 ratio in 6 day cultures. Engrafted T cells of donor karyotype gave much smaller responses to irradiated genetically recipient B cells than did fresh donor T cells. Moreover, engrafted T cells of donor karyotype from two of the three SCIDs who are longest post-transplantation responded more vigorously (14,685 and 31,623 cpm) than fresh donor T cells (5141 and 22,709 cpm) to donor B cells. These data indicate that T lymphocytes which have matured from donor stem cells in the recipient microenvironment behave differently from those that have matured in the donor.

  6. A novel immunoregulatory protein in human colostrum, syntenin-1, for promoting the development of IgA-producing cells from cord blood B cells.

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    Sira, Mostafa M; Yoshida, Taketoshi; Takeuchi, Makoto; Kashiwayama, Yoshinori; Futatani, Takeshi; Kanegane, Hirokazu; Sasahara, Akiko; Ito, Yasunori; Mizuguchi, Mineyuki; Imanaka, Tsuneo; Miyawaki, Toshio

    2009-09-01

    Human colostrum contains many bioactive factors that must promote the development of intestinal mucosal immunity in infants. Especially, the presence of certain cytokines such as transforming growth factor (TGF)-beta or IL-10 has been of great interest for IgA production as a function of mucosal immune response. In the present study, we attempted to investigate whether unidentified factors inducing generation of IgA-producing cells from naive B cells might exist in colostrum. For this purpose, colostrum samples were directly added to a culture consisting of naive B cells and dendritic cells from cord blood and CD40 ligand-transfected L cells, comparing with recombinant IL-10 (rIL-10) and/or rTGF-beta. It was noted that most colostrum samples alone were able to induce IgA-secreting cells at higher levels than rIL-10 and/or rTGF-beta. IgA-inducing activity of colostrum was abolished by neither anti-neutralizing mAbs against IL-10 nor TGF-beta, though partially by anti-IL-6 mAb. We prepared partially purified fractions from both pooled colostrums with and without IgA-inducing activity and comparatively performed quantitative proteomic analysis by two-dimensional difference gel electrophoresis followed by liquid chromatography-mass spectrometry. As a result, syntenin-1 was identified as a candidate for IgA-inducing protein in colostrum. Western blot analysis indicated that levels of syntenin-1 in colostrum samples were correlated with their IgA-inducing activities. Moreover, we demonstrated that recombinant syntenin-1 could induce preferentially IgA production from naive B cells. These results suggest that syntenin-1 serves as one of IgA-inducing factors for B cells.

  7. High resolution analysis of the chromatin landscape of the IgE switch region in human B cells.

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    Sandeep Dayal

    Full Text Available Antibodies are assembled by a highly orchestrated series of recombination events during B cell development. One of these events, class switch recombination, is required to produce the IgG, IgE and IgA antibody isotypes characteristic of a secondary immune response. The action of the enzyme activation induced cytidine deaminase is now known to be essential for the initiation of this recombination event. Previous studies have demonstrated that the immunoglobulin switch regions acquire distinct histone modifications prior to recombination. We now present a high resolution analysis of these histone modifications across the IgE switch region prior to the initiation of class switch recombination in primary human B cells and the human CL-01 B cell line. These data show that upon stimulation with IL-4 and an anti-CD40 antibody that mimics T cell help, the nucleosomes of the switch regions are highly modified on histone H3, accumulating acetylation marks and tri-methylation of lysine 4. Distinct peaks of modified histones are found across the switch region, most notably at the 5' splice donor site of the germline (I exon, which also accumulates AID. These data suggest that acetylation and K4 tri-methylation of histone H3 may represent marks of recombinationally active chromatin and further implicates splicing in the regulation of AID action.

  8. Development Refractoriness of MLL-Rearranged Human B Cell Acute Leukemias to Reprogramming into Pluripotency

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    Alvaro Muñoz-López

    2016-10-01

    Full Text Available Induced pluripotent stem cells (iPSCs are a powerful tool for disease modeling. They are routinely generated from healthy donors and patients from multiple cell types at different developmental stages. However, reprogramming leukemias is an extremely inefficient process. Few studies generated iPSCs from primary chronic myeloid leukemias, but iPSC generation from acute myeloid or lymphoid leukemias (ALL has not been achieved. We attempted to generate iPSCs from different subtypes of B-ALL to address the developmental impact of leukemic fusion genes. OKSM(L-expressing mono/polycistronic-, retroviral/lentiviral/episomal-, and Sendai virus vector-based reprogramming strategies failed to render iPSCs in vitro and in vivo. Addition of transcriptomic-epigenetic reprogramming “boosters” also failed to generate iPSCs from B cell blasts and B-ALL lines, and when iPSCs emerged they lacked leukemic fusion genes, demonstrating non-leukemic myeloid origin. Conversely, MLL-AF4-overexpressing hematopoietic stem cells/B progenitors were successfully reprogrammed, indicating that B cell origin and leukemic fusion gene were not reprogramming barriers. Global transcriptome/DNA methylome profiling suggested a developmental/differentiation refractoriness of MLL-rearranged B-ALL to reprogramming into pluripotency.

  9. Absence of C-type virus production in human leukemic B cell, T cell and null cell lines.

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    Ogura,Hajime

    1978-06-01

    Full Text Available Electron microscope observation of cultured human leukemic B cell, T cell and null cell lines and reverse transcriptase assay of the culture supernatants were all negative for the presence of C-type virus. Bat cell line, which propagates primate C-type viruses well, was cocultivated with the human leukemic cell lines, in the hope of amplification of virus if present. Three weeks after mixed culture, the culture supernatants were again examined for reverse transcriptase activity and the cells were tested for syncytia formation by cocultivation with rat XC, human KC and RSb cell lines. All these tests, except for the positive control using a simian sarcoma virus, were negative, suggesting that no C-type was produced from these human leukemic cell lines.

  10. Lack of TERT Promoter Mutations in Human B-Cell Non-Hodgkin Lymphoma

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    Gary Lam

    2016-10-01

    Full Text Available Non-Hodgkin lymphomas (NHL are a heterogeneous group of immune cell neoplasms that comprise molecularly distinct lymphoma subtypes. Recent work has identified high frequency promoter point mutations in the telomerase reverse transcriptase (TERT gene of different cancer types, including melanoma, glioma, liver and bladder cancer. TERT promoter mutations appear to correlate with increased TERT expression and telomerase activity in these cancers. In contrast, breast, pancreatic, and prostate cancer rarely demonstrate mutations in this region of the gene. TERT promoter mutation prevalence in NHL has not been thoroughly tested thus far. We screened 105 B-cell lymphoid malignancies encompassing nine NHL subtypes and acute lymphoblastic leukemia, for TERT promoter mutations. Our results suggest that TERT promoter mutations are rare or absent in most NHL. Thus, the classical TERT promoter mutations may not play a major oncogenic role in TERT expression and telomerase activation in NHL.

  11. Lack of TERT Promoter Mutations in Human B-Cell Non-Hodgkin Lymphoma

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    Lam, Gary; Xian, Rena R.; Li, Yingying; Burns, Kathleen H.; Beemon, Karen L.

    2016-01-01

    Non-Hodgkin lymphomas (NHL) are a heterogeneous group of immune cell neoplasms that comprise molecularly distinct lymphoma subtypes. Recent work has identified high frequency promoter point mutations in the telomerase reverse transcriptase (TERT) gene of different cancer types, including melanoma, glioma, liver and bladder cancer. TERT promoter mutations appear to correlate with increased TERT expression and telomerase activity in these cancers. In contrast, breast, pancreatic, and prostate cancer rarely demonstrate mutations in this region of the gene. TERT promoter mutation prevalence in NHL has not been thoroughly tested thus far. We screened 105 B-cell lymphoid malignancies encompassing nine NHL subtypes and acute lymphoblastic leukemia, for TERT promoter mutations. Our results suggest that TERT promoter mutations are rare or absent in most NHL. Thus, the classical TERT promoter mutations may not play a major oncogenic role in TERT expression and telomerase activation in NHL. PMID:27792139

  12. CD9 may contribute to the survival of human germinal center B cells by facilitating the interaction with follicular dendritic cells

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    Sun-Ok Yoon

    2014-01-01

    Full Text Available The germinal center (GC is a dynamic microenvironment where antigen (Ag-activated B cells rapidly expand and differentiate, generating plasma cells (PC that produce high-affinity antibodies. Precise regulation of survival and proliferation of Ag-activated B cells within the GC is crucial for humoral immune responses. The follicular dendritic cells (FDC are the specialized stromal cells in the GC that prevent apoptosis of GC-B cells. Recently, we reported that human GC-B cells consist of CD9+ and CD9− populations and that it is the CD9+ cells that are committed to the PC lineage. In this study, we investigated the functional role of CD9 on GC-B cells. Tonsillar tissue section staining revealed that in vivo CD9+ GC-B cells localized in the light zone FDC area. Consistent this, in vitro CD9+ GC-B cells survived better than CD9− GC-B cells in the presence of HK cells, an FDC line, in a cell–cell contact-dependent manner. The frozen tonsillar tissue section binding assay showed that CD9+ GC-B cells bound to the GC area of tonsillar tissues significantly more than the CD9− GC-B cells did and that the binding was significantly inhibited by neutralizing anti-integrin β1 antibody. Furthermore, CD9+ cells bound to soluble VCAM-1 more than CD9− cells did, resulting in activation and stabilization of the active epitope of integrin β1. All together, our data suggest that CD9 on GC-B cells contributes to survival by strengthening their binding to FDC through the VLA4/VCAM-1 axis.

  13. B Cell Activity Is Impaired in Human and Mouse Obesity and Is Responsive to an Essential Fatty Acid upon Murine Influenza Infection.

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    Kosaraju, Rasagna; Guesdon, William; Crouch, Miranda J; Teague, Heather L; Sullivan, E Madison; Karlsson, Erik A; Schultz-Cherry, Stacey; Gowdy, Kymberly; Bridges, Lance C; Reese, Lauren R; Neufer, P Darrell; Armstrong, Michael; Reisdorph, Nichole; Milner, J Justin; Beck, Melinda; Shaikh, Saame Raza

    2017-06-15

    Obesity is associated with increased risk for infections and poor responses to vaccinations, which may be due to compromised B cell function. However, there is limited information about the influence of obesity on B cell function and underlying factors that modulate B cell responses. Therefore, we studied B cell cytokine secretion and/or Ab production across obesity models. In obese humans, B cell IL-6 secretion was lowered and IgM levels were elevated upon ex vivo anti-BCR/TLR9 stimulation. In murine obesity induced by a high fat diet, ex vivo IgM and IgG were elevated with unstimulated B cells. Furthermore, the high fat diet lowered bone marrow B cell frequency accompanied by diminished transcripts of early lymphoid commitment markers. Murine B cell responses were subsequently investigated upon influenza A/Puerto Rico/8/34 infection using a Western diet model in the absence or presence of docosahexaenoic acid (DHA). DHA, an essential fatty acid with immunomodulatory properties, was tested because its plasma levels are lowered in obesity. Relative to controls, mice consuming the Western diet had diminished Ab titers whereas the Western diet plus DHA improved titers. Mechanistically, DHA did not directly target B cells to elevate Ab levels. Instead, DHA increased the concentration of the downstream specialized proresolving lipid mediators (SPMs) 14-hydroxydocosahexaenoic acid, 17-hydroxydocosahexaenoic acid, and protectin DX. All three SPMs were found to be effective in elevating murine Ab levels upon influenza infection. Collectively, the results demonstrate that B cell responses are impaired across human and mouse obesity models and show that essential fatty acid status is a factor influencing humoral immunity, potentially through an SPM-mediated mechanism. Copyright © 2017 by The American Association of Immunologists, Inc.

  14. Genome-wide analysis of immune activation in human T and B cells reveals distinct classes of alternatively spliced genes.

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    Yevgeniy A Grigoryev

    Full Text Available Alternative splicing of pre-mRNA is a mechanism that increases the protein diversity of a single gene by differential exon inclusion/exclusion during post-transcriptional processing. While alternative splicing is established to occur during lymphocyte activation, little is known about the role it plays during the immune response. Our study is among the first reports of a systematic genome-wide analysis of activated human T and B lymphocytes using whole exon DNA microarrays integrating alternative splicing and differential gene expression. Purified human CD2(+ T or CD19(+ B cells were activated using protocols to model the early events in post-transplant allograft immunity and sampled as a function of time during the process of immune activation. Here we show that 3 distinct classes of alternatively spliced and/or differentially expressed genes change in an ordered manner as a function of immune activation. We mapped our results to function-based canonical pathways and demonstrated that some are populated by only one class of genes, like integrin signaling, while other pathways, such as purine metabolism and T cell receptor signaling, are populated by all three classes of genes. Our studies augment the current view of T and B cell activation in immunity that has been based exclusively upon differential gene expression by providing evidence for a large number of molecular networks populated as a function of time and activation by alternatively spliced genes, many of which are constitutively expressed.

  15. Analysis of B Cell Repertoire Dynamics Following Hepatitis B Vaccination in Humans, and Enrichment of Vaccine-specific Antibody Sequences

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    Jacob D. Galson

    2015-12-01

    Full Text Available Generating a diverse B cell immunoglobulin repertoire is essential for protection against infection. The repertoire in humans can now be comprehensively measured by high-throughput sequencing. Using hepatitis B vaccination as a model, we determined how the total immunoglobulin sequence repertoire changes following antigen exposure in humans, and compared this to sequences from vaccine-specific sorted cells. Clonal sequence expansions were seen 7 days after vaccination, which correlated with vaccine-specific plasma cell numbers. These expansions caused an increase in mutation, and a decrease in diversity and complementarity-determining region 3 sequence length in the repertoire. We also saw an increase in sequence convergence between participants 14 and 21 days after vaccination, coinciding with an increase of vaccine-specific memory cells. These features allowed development of a model for in silico enrichment of vaccine-specific sequences from the total repertoire. Identifying antigen-specific sequences from total repertoire data could aid our understanding B cell driven immunity, and be used for disease diagnostics and vaccine evaluation.

  16. Human lymphoblastoid B-cell lines reprogrammed to EBV-free induced pluripotent stem cells.

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    Rajesh, Deepika; Dickerson, Sarah J; Yu, Junying; Brown, Matthew E; Thomson, James A; Seay, Nicholas J

    2011-08-18

    Generation of patient-specific induced pluripotent cells (iPSCs) holds great promise for regenerative medicine. Epstein-Barr virus immortalized lymphoblastoid B-cell lines (LCLs) can be generated from a minimal amount of blood and are banked worldwide as cellular reference material for immunologic or genetic analysis of pedigreed study populations. We report the generation of iPSCs from 2 LCLs (LCL-iPSCs) via a feeder-free episomal method using a cocktail of transcription factors and small molecules. LCL-derived iPSCs exhibited normal karyotype, expressed pluripotency markers, lost oriP/EBNA-1 episomal vectors, generated teratomas, retained donor identity, and differentiated in vitro into hematopoietic, cardiac, neural, and hepatocyte-like lineages. Significantly, although the parental LCLs express viral EBNA-1 and other Epstein-Barr virus latency-related elements for their survival, their presence was not detectable in LCL-iPSCs. Thus, reprogramming LCLs could offer an unlimited source for patient-specific iPSCs.

  17. Pre-B-cell leukemia homeobox interacting protein 1 is overexpressed in astrocytoma and promotes tumor cell growth and migration

    Science.gov (United States)

    van Vuurden, Dannis G.; Aronica, Eleonora; Hulleman, Esther; Wedekind, Laurine E.; Biesmans, Dennis; Malekzadeh, Arjan; Bugiani, Marianna; Geerts, Dirk; Noske, David P.; Vandertop, W. Peter; Kaspers, Gertjan J.L.; Cloos, Jacqueline; Würdinger, Thomas; van der Stoop, Petra P.M.

    2014-01-01

    Background Glial brain tumors cause considerable mortality and morbidity in children and adults. Innovative targets for therapy are needed to improve survival and reduce long-term sequelae. The aim of this study was to find a candidate tumor-promoting protein, abundantly expressed in tumor cells but not in normal brain tissues, as a potential target for therapy. Methods In silico proteomics and genomics, immunohistochemistry, and immunofluorescence microscopy validation were performed. RNA interference was used to ascertain the functional role of the overexpressed candidate target protein. Results In silico proteomics and genomics revealed pre-B-cell leukemia homeobox (PBX) interacting protein 1 (PBXIP1) overexpression in adult and childhood high-grade glioma and ependymoma compared with normal brain. PBXIP1 is a PBX-family interacting microtubule-binding protein with a putative role in migration and proliferation of cancer cells. Immunohistochemical studies in glial tumors validated PBXIP1 expression in astrocytoma and ependymoma but not in oligodendroglioma. RNAi-mediated PBXIP1-knockdown in glioblastoma cell lines strongly reduced proliferation and migration and induced morphological changes, indicating that PBXIP1 knockdown decreases glioma cell viability and motility through rearrangements of the actin cytoskeleton. Furthermore, expression of PBXIP1 was observed in radial glia and astrocytic progenitor cells in human fetal tissues, suggesting that PBXIP1 is an astroglial progenitor cell marker during human embryonic development. Conclusion PBXIP1 is a novel protein overexpressed in astrocytoma and ependymoma, involved in tumor cell proliferation and migration, that warrants further exploration as a novel therapeutic target in these tumors. PMID:24470547

  18. Human pregnancy-associated malaria-specific B cells target polymorphic, conformational epitopes in VAR2CSA

    DEFF Research Database (Denmark)

    Barfod, L.; Bernasconi, N. L.; Dahlback, M.

    2007-01-01

    , are targets of IgG-mediated protective immunity to PAM. Here, we report an investigation of the specificity of naturally acquired immunity to PAM, using eight human monoclonal IgG1 antibodies that react exclusively with intact CSA-adhering IEs expressing VSA(PAM). Four reacted in Western blotting with high......-specific protective immunity, and demonstrate the value of human monoclonal antibodies and conformationally intact recombinant antigens in VSA characterization....... to evaluate B-cell epitope diversity among parasite isolates, and identified the binding site of one monoclonal antibody using a chimeric DBL3-X construct. Our findings show that there is a high-frequency memory response to VSA(PAM), indicating that VAR2CSA is a primary target of naturally acquired PAM...

  19. Antibodies specific for a segment of human membrane IgE deplete IgE-producing B cells in humanized mice.

    Science.gov (United States)

    Brightbill, Hans D; Jeet, Surinder; Lin, Zhonghua; Yan, Donghong; Zhou, Meijuan; Tan, Martha; Nguyen, Allen; Yeh, Sherry; Delarosa, Donnie; Leong, Steven R; Wong, Terence; Chen, Yvonne; Ultsch, Mark; Luis, Elizabeth; Ramani, Sree Ranjani; Jackman, Janet; Gonzalez, Lino; Dennis, Mark S; Chuntharapai, Anan; DeForge, Laura; Meng, Y Gloria; Xu, Min; Eigenbrot, Charles; Lee, Wyne P; Refino, Canio J; Balazs, Mercedesz; Wu, Lawren C

    2010-06-01

    IgE-mediated hypersensitivity is central to the pathogenesis of asthma and other allergic diseases. Although neutralization of serum IgE with IgE-specific antibodies is in general an efficacious treatment for allergic asthma, one limitation of this approach is its lack of effect on IgE production. Here, we have developed a strategy to disrupt IgE production by generating monoclonal antibodies that target a segment of membrane IgE on human IgE-switched B cells that is not present in serum IgE. This segment is known as the M1' domain, and using genetically modified mice that contain the human M1' domain inserted into the mouse IgE locus, we demonstrated that M1'-specific antibodies reduced serum IgE and IgE-producing plasma cells in vivo, without affecting other immunoglobulin isotypes. M1'-specific antibodies were effective when delivered prophylactically and therapeutically in mouse models of immunization, allergic asthma, and Nippostrongylus brasiliensis infection, likely by inducing apoptosis of IgE-producing B cells. In addition, we generated a humanized M1'-specific antibody that was active on primary human cells in vivo, as determined by its reduction of serum IgE levels and IgE plasma cell numbers in a human PBMC-SCID mouse model. Thus, targeting of human IgE-producing B cells with apoptosis-inducing M1'-specific antibodies may be a novel treatment for asthma and allergy.

  20. The B-cell stimulatory cytokines BLyS and APRIL are elevated in human periodontitis and are required for B-cell–dependent bone loss in experimental murine periodontitis1

    Science.gov (United States)

    Abe, Toshiharu; AlSarhan, Mohammed; Benakanakere, Manjunatha R.; Maekawa, Tomoki; Kinane, Denis F.; Cancro, Michael P.; Korostoff, Jonathan M.; Hajishengallis, George

    2015-01-01

    B-lineage cells (B lymphocytes and plasma cells) predominate in the inflammatory infiltrate of human chronic periodontitis. However, their role in disease pathogenesis and the factors responsible for their persistence in chronic lesions are poorly understood. In this regard, two cytokines of the TNF ligand superfamily, namely a proliferation-inducing ligand (APRIL) and B-lymphocyte stimulator (BLyS), are important for the survival, proliferation, and maturation of B cells. We thus hypothesized that APRIL and/or BLyS are upregulated in periodontitis and contribute to induction of periodontal bone loss. This hypothesis was addressed in both human and mouse experimental systems. We show that, relative to healthy controls, the expression of APRIL and BLyS mRNA and protein was upregulated in natural and experimental periodontitis in humans and mice, respectively. The elevated expression of these cytokines correlated with increased numbers of B cells/plasma cells in both species. Moreover, APRIL and BLyS partially colocalized with kappa light chain-expressing B lineage cells at the epithelial-connective tissue interface. Ligature-induced periodontitis resulted in significantly less bone loss in B cell-deficient mice compared to wild-type controls. Ab-mediated neutralization of APRIL or BLyS diminished the number of B cells in the gingival tissue and inhibited bone loss in wild-type but not in B cell-deficient mice. In conclusion, B cells and specific cytokines involved in their growth and differentiation contribute to periodontal bone loss. Moreover, APRIL and BLyS have been identified as potential therapeutic targets in periodontitis. PMID:26150532

  1. Ratios of Four STAT3 Splice Variants in Human Eosinophils and Diffuse Large B Cell Lymphoma Cells.

    Science.gov (United States)

    Turton, Keren B; Annis, Douglas S; Rui, Lixin; Esnault, Stephane; Mosher, Deane F

    2015-01-01

    Signal transducer and activator of transcription 3 (STAT3) is a key mediator of leukocyte differentiation and proliferation. The 3' end of STAT3 transcripts is subject to two alternative splicing events. One results in either full-length STAT3α or in STAT3β, which lacks part of the C-terminal transactivation domain. The other is at a tandem donor (5') splice site and results in the codon for Ser-701 being included (S) or excluded (ΔS). Despite the proximity of Ser-701 to the site of activating phosphorylation at Tyr-705, ΔS/S splicing has barely been studied. Sequencing of cDNA from purified eosinophils revealed the presence of four transcripts (S-α, ΔS-α, S-β, and ΔS-β) rather than the three reported in publically available databases from which ΔS-β is missing. To gain insight into regulation of the two alternative splicing events, we developed a quantitative(q) PCR protocol to compare transcript ratios in eosinophils in which STAT3 is upregulated by cytokines, activated B cell diffuse large B cell Lymphoma (DLBCL) cells in which STAT3 is dysregulated, and in germinal center B cell-like DLBCL cells in which it is not. With the exception of one line of activated B cell DLCBL cells, the four variants were found in roughly the same ratios despite differences in total levels of STAT3 transcripts. S-α was the most abundant, followed by S-β. ΔS-α and ΔS-β together comprised 15.6 ± 4.0 % (mean ± SD, n = 21) of the total. The percentage of STAT3β variants that were ΔS was 1.5-fold greater than of STAT3α variants that were ΔS. Inspection of Illumina's "BodyMap" RNA-Seq database revealed that the ΔS variant accounts for 10-26 % of STAT3 transcripts across 16 human tissues, with less variation than three other genes with the identical tandem donor splice site sequence. Thus, it seems likely that all cells contain the S-α, ΔS-α, S-β, and ΔS-β variants of STAT3.

  2. Ratios of Four STAT3 Splice Variants in Human Eosinophils and Diffuse Large B Cell Lymphoma Cells.

    Directory of Open Access Journals (Sweden)

    Keren B Turton

    Full Text Available Signal transducer and activator of transcription 3 (STAT3 is a key mediator of leukocyte differentiation and proliferation. The 3' end of STAT3 transcripts is subject to two alternative splicing events. One results in either full-length STAT3α or in STAT3β, which lacks part of the C-terminal transactivation domain. The other is at a tandem donor (5' splice site and results in the codon for Ser-701 being included (S or excluded (ΔS. Despite the proximity of Ser-701 to the site of activating phosphorylation at Tyr-705, ΔS/S splicing has barely been studied. Sequencing of cDNA from purified eosinophils revealed the presence of four transcripts (S-α, ΔS-α, S-β, and ΔS-β rather than the three reported in publically available databases from which ΔS-β is missing. To gain insight into regulation of the two alternative splicing events, we developed a quantitative(q PCR protocol to compare transcript ratios in eosinophils in which STAT3 is upregulated by cytokines, activated B cell diffuse large B cell Lymphoma (DLBCL cells in which STAT3 is dysregulated, and in germinal center B cell-like DLBCL cells in which it is not. With the exception of one line of activated B cell DLCBL cells, the four variants were found in roughly the same ratios despite differences in total levels of STAT3 transcripts. S-α was the most abundant, followed by S-β. ΔS-α and ΔS-β together comprised 15.6 ± 4.0 % (mean ± SD, n = 21 of the total. The percentage of STAT3β variants that were ΔS was 1.5-fold greater than of STAT3α variants that were ΔS. Inspection of Illumina's "BodyMap" RNA-Seq database revealed that the ΔS variant accounts for 10-26 % of STAT3 transcripts across 16 human tissues, with less variation than three other genes with the identical tandem donor splice site sequence. Thus, it seems likely that all cells contain the S-α, ΔS-α, S-β, and ΔS-β variants of STAT3.

  3. Identification of human papillomavirus-16 E6 variation in cervical cancer and their impact on T and B cell epitopes.

    Science.gov (United States)

    Kumar, Anoop; Hussain, Showket; Yadav, Inderjit Singh; Gissmann, Lutz; Natarajan, K; Das, Bhudev C; Bharadwaj, Mausumi

    2015-06-15

    The infection with high-risk human papillomavirus (HR-HPV) is the most important risk factor for development of cervical cancer. The intra-type variations of HPV have different biological and pathological consequences with respect to disease progression. In the present study, six major Indian variants were experimentally identified in E6 gene of HPV-16 and showed their impact on immunogenicity by in silico methods. Four different phylogenetic lineages were observed in sequences including European (E) prototype, European variant, Asian and American Asian variant classes and complete absence of African phylogenetic lineages. On the prediction of B- and T-cell epitopes, 18 and 23 potent epitopes for MHC-II alleles, 10 potent MHC-I and 15 B-cell epitopes in each reference and variant sequence were identified. Interestingly, the presence of variation H78Y and L83V result in creation of four new epitopes for the HLA-DQA1*0101/DQB1*0501. Out of 15 B-cell predicted epitopes, three most potent epitopes were identified in both reference and variant sequence. Notably the amino acid stretch from amino acid 16-60 and 76-94 are very important for the immunological properties of E6 protein because these regions contain majority of the predicted epitopes. In future, this could control the cervical cancer by targeting these amino acid stretches for the development of HPV-16 vaccine.

  4. Lipoxin A4 decreases human memory B cell antibody production via an ALX/FPR2-dependent mechanism: A link between resolution signals and adaptive immunity

    Science.gov (United States)

    Ramon, Sesquile; Bancos, Simona; Serhan, Charles N.; Phipps, Richard P.

    2013-01-01

    Summary Specialized proresolving mediators (SPMs) are endogenous bioactive lipid molecules that play a fundamental role in the regulation of inflammation and its resolution. SPMs are classified into lipoxins, resolvins, protectins and maresins. Lipoxins and other SPMs have been identified in important immunological tissues including bone marrow, spleen and blood. Lipoxins regulate functions of the innate immune system including the promotion of monocyte recruitment and increase macrophage phagocytosis of apoptotic neutrophils. A major knowledge gap is whether lipoxins influence adaptive immune cells. Here, we analyzed the actions of lipoxin A4 (LXA4) and its receptor ALX/FPR2 on human B cells. LXA4 decreased IgM and IgG production on activated B cells through ALX/FPR2-dependent signaling, which downregulated NF-κB p65 nuclear translocation. LXA4 also inhibited human memory B cell antibody production and proliferation, but not naïve B cell function. Lastly, LXA4 decreased antigen-specific antibody production in vivo. To our knowledge, this is the first description of the actions of lipoxins on human B cells, which shows a link between resolution signals and adaptive immunity. Regulating antibody production is crucial to prevent unwanted inflammation. Harnessing the ability of lipoxins to decrease memory B cell antibody production can be beneficial to threat inflammatory and autoimmune disorders. PMID:24166736

  5. Restoration of human B-cell differentiation into NOD-SCID mice engrafted with gene-corrected CD34+ cells isolated from Artemis or RAG1-deficient patients.

    Science.gov (United States)

    Lagresle-Peyrou, Chantal; Benjelloun, Fatine; Hue, Christophe; Andre-Schmutz, Isabelle; Bonhomme, Delphine; Forveille, Monique; Beldjord, Kheira; Hacein-Bey-Abina, Salima; De Villartay, Jean-Pierre; Charneau, Pierre; Durandy, Anne; Fischer, Alain; Cavazzana-Calvo, Marina

    2008-02-01

    Severe combined immunodeficiency (SCID) caused by mutation of the recombination-activating gene 1 (RAG1) or Artemis gene lead to the absence of B- and T-cell differentiation. The only curative treatment is allogeneic bone marrow (BM) transplantation, which displays a high survival rate when an HLA compatible donor is available but has a poorer prognosis when the donor is partially compatible. Consequently, gene therapy may be a promising alternative strategy for these diseases. Here, we report that lentiviral gene-corrected BM CD34(+) cells (isolated from Artemis- or RAG1-deficient patients) sustain human B-cell differentiation following injection into non-obese diabetic/SCID (NOD-SCID) mice previously infused with anti-interleukin-2 receptor beta chain monoclonal antibody. In most of the mice BM, engrafted with Artemis-transduced cells, human B-cell differentiation occurred until the mature stage. The B cells were functional as human immunoglobulin M (IgM) was present in the serum. Following injection with RAG1-transduced cells, human engraftment occurred in vivo but B-cell differentiation until the mature stage was less frequent. However, when it occurred, it was always associated with human IgM production. This overall approach represents a useful tool for evaluating gene transfer efficiency in human SCID forms affecting B-cell development (such as Artemis deficiency) and for testing new vectors for improving in vivo RAG1 complementation.

  6. Combined immunodeficiency and Epstein-Barr virus-induced B cell malignancy in humans with inherited CD70 deficiency

    DEFF Research Database (Denmark)

    Abolhassani, Hassan; Edwards, Emily S. J.; Ikinciogullari, Aydan

    2017-01-01

    is a novel cause of combined immunodeficiency and EBV-associated diseases, reminiscent of inherited CD27 deficiency. Overall, human CD70-CD27 interactions therefore play a nonredundant role in T and B cell-mediated immunity, especially for protection against EBV and humoral immunity.......In this study, we describe four patients from two unrelated families of different ethnicities with a primary immunodeficiency, predominantly manifesting as susceptibility to Epstein-Barr virus (EBV)-related diseases. Three patients presented with EBV-associated Hodgkin's lymphoma...... and hypogammaglobulinemia; one also had severe varicella infection. The fourth had viral encephalitis during infancy. Homozygous frameshift or in-frame deletions in CD70 in these patients abolished either CD70 surface expression or binding to its cognate receptor CD27. Blood lymphocyte numbers were normal...

  7. Spontaneous complement activation on human B cells results in localized membrane depolarization and the clustering of complement receptor type 2 and C3 fragments

    DEFF Research Database (Denmark)

    Løbner, Morten; Leslie, Robert G Q; Prodinger, Wolfgang M

    2009-01-01

    While our previous studies have demonstrated that complement activation induced by complement receptors type 2 (CR2/CD21) and 1 (CR1/CD35) results in C3-fragment deposition and membrane attack complex (MAC) formation in human B cells, the consequences of these events for B-cell functions remain...... requires activation of complement via the alternative pathway, as indicated by total inhibition upon neutralization of factor D, and is abrogated by combined blockade of CR1 and CR2, but not of either receptor alone. The membrane depolarization is not associated with the apoptosis of B cells, as examined...... by co-staining with APO-2.7 or by the TdT-mediated biotin-dUTP nick-end labelling (TUNEL) assay. Confocal microscopy revealed that depolarization and C3 deposition, unlike MAC deposition, are limited to restricted areas on the B-cell surface. Double staining revealed a close association between the C3...

  8. Identification of linear human B-cell epitopes of tick-borne encephalitis virus

    OpenAIRE

    Kuivanen, Suvi; Hepojoki, Jussi; Vene, Sirkka; Vaheri, Antti; Vapalahti, Olli

    2014-01-01

    Background Tick-borne encephalitis (TBE) is a central nervous system infection transmitted to humans by ticks. The causative agent, tick-borne encephalitis virus (TBEV), belongs to the genus Flavivirus (family Flaviviridae), which includes globally important arthropod-borne viruses, such as dengue, Yellow fever, Japanese encephalitis and West Nile viruses. Flaviviruses are highly cross-reactive in serological tests that are currently based on viral envelope proteins. The envelope (E) protein ...

  9. The role of T and B cells in human atherosclerosis and atherothrombosis.

    Science.gov (United States)

    Ammirati, E; Moroni, F; Magnoni, M; Camici, P G

    2015-02-01

    Far from being merely a passive cholesterol accumulation within the arterial wall, the development of atherosclerosis is currently known to imply both inflammation and immune effector mechanisms. Adaptive immunity has been implicated in the process of disease initiation and progression interwined with traditional cardiovascular risk factors. Although the body of knowledge regarding the correlation between atherosclerosis and immunity in humans is growing rapidly, a relevant proportion of it derives from studies carried out in animal models of cardiovascular disease (CVD). However, while the mouse is a well-suited model, the results obtained therein are not fully transferrable to the human setting due to intrinsic genomic and environmental differences. In the present review, we will discuss mainly human findings, obtained either by examination of post-mortem and surgical atherosclerotic material or through the analysis of the immunological profile of peripheral blood cells. In particular, we will discuss the findings supporting a pro-atherogenic role of T cell subsets, such as effector memory T cells or the potential protective function of regulatory T cells. Recent studies suggest that traditional T cell-driven B2 cell responses appear to be atherogenic, while innate B1 cells appear to exert a protective action through the secretion of naturally occurring antibodies. The insights into the immune pathogenesis of atherosclerosis can provide new targets in the quest for novel therapeutic targets to abate CVD morbidity and mortality. © 2014 British Society for Immunology.

  10. B-cell activating factor receptor deficiency is associated with an adult-onset antibody deficiency syndrome in humans

    OpenAIRE

    Warnatz, Klaus; Salzer, Ulrich; Rizzi, Marta; Fischer, Beate; Gutenberger, Sylvia; Böhm, Joachim; Kienzler, Anne-Kathrin; Pan-Hammarström, Qiang; Hammarström, Lennart; Rakhmanov, Mirzokhid; Schlesier, Michael; Grimbacher, Bodo; Peter, Hans-Hartmut; Eibel, Hermann

    2009-01-01

    B-cell survival depends on signals induced by B-cell activating factor (BAFF) binding to its receptor (BAFF-R). In mice, mutations in BAFF or BAFF-R cause B-cell lymphopenia and antibody deficiency. Analyzing BAFF-R expression and BAFF-binding to B cells in common variable immunodeficiency (CVID) patients, we identified two siblings carrying a homozygous deletion in the BAFF-R gene. Removing most of the BAFF-R transmembrane part, the deletion precludes BAFF-R expression. Without BAFF-R, B-cel...

  11. Role of reactive oxygen species in arsenic-induced transformation of human lung bronchial epithelial (BEAS-2B) cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhuo, E-mail: zhuo.zhang@uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok [Center for Research on Environmental Diseases, University of Kentucky, Lexington, KY 40536 (United States); Kim, Donghern [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin [Center for Research on Environmental Diseases, University of Kentucky, Lexington, KY 40536 (United States)

    2015-01-09

    Highlights: • Short term exposure of cells to arsenic causes ROS generation. • Chronical exposure of cells to arsenic causes malignant cell transformation. • Inhibition of ROS generation reduces cell transformation by arsenic. • Arsenic-transformed cells exhibit reduced capacity of generating ROS. • Arsenic-transformed cells exhibit increased levels of antioxidants. - Abstract: Arsenic is an environmental carcinogen, its mechanisms of carcinogenesis remain to be investigated. Reactive oxygen species (ROS) are considered to be important. A previous study (Carpenter et al., 2011) has measured ROS level in human lung bronchial epithelial (BEAS-2B) cells and arsenic-transformed BEAS-2B cells and found that ROS levels were higher in transformed cells than that in parent normal cells. Based on these observations, the authors concluded that cell transformation induced by arsenic is mediated by increased cellular levels of ROS. This conclusion is problematic because this study only measured the basal ROS levels in transformed and parent cells and did not investigate the role of ROS in the process of arsenic-induced cell transformation. The levels of ROS in arsenic-transformed cells represent the result and not the cause of cell transformation. Thus question concerning whether ROS are important in arsenic-induced cell transformation remains to be answered. In the present study, we used expressions of catalase (antioxidant against H{sub 2}O{sub 2}) and superoxide dismutase 2 (SOD2, antioxidant against O{sub 2}{sup ·−}) to decrease ROS level and investigated their role in the process of arsenic-induced cell transformation. Our results show that inhibition of ROS by antioxidant enzymes decreased arsenic-induced cell transformation, demonstrating that ROS are important in this process. We have also shown that in arsenic-transformed cells, ROS generation was lower and levels of antioxidants are higher than those in parent cells, in a disagreement with the previous

  12. Identification of continuous human B-cell epitopes in the VP35, VP40, nucleoprotein and glycoprotein of Ebola virus.

    Directory of Open Access Journals (Sweden)

    Pierre Becquart

    Full Text Available Ebola virus (EBOV is a highly virulent human pathogen. Recovery of infected patients is associated with efficient EBOV-specific immunoglobulin G (IgG responses, whereas fatal outcome is associated with defective humoral immunity. As B-cell epitopes on EBOV are poorly defined, we sought to identify specific epitopes in four EBOV proteins (Glycoprotein (GP, Nucleoprotein (NP, and matrix Viral Protein (VP40 and VP35. For the first time, we tested EBOV IgG+ sera from asymptomatic individuals and symptomatic Gabonese survivors, collected during the early humoral response (seven days after the end of symptoms and the late memory phase (7-12 years post-infection. We also tested sera from EBOV-seropositive patients who had never had clinical signs of hemorrhagic fever or who lived in non-epidemic areas (asymptomatic subjects. We found that serum from asymptomatic individuals was more strongly reactive to VP40 peptides than to GP, NP or VP35. Interestingly, anti-EBOV IgG from asymptomatic patients targeted three immunodominant regions of VP40 reported to play a crucial role in virus assembly and budding. In contrast, serum from most survivors of the three outbreaks, collected a few days after the end of symptoms, reacted mainly with GP peptides. However, in asymptomatic subjects the longest immunodominant domains were identified in GP, and analysis of the GP crystal structure revealed that these domains covered a larger surface area of the chalice bowl formed by three GP1 subunits. The B-cell epitopes we identified in the EBOV VP35, VP40, NP and GP proteins may represent important tools for understanding the humoral response to this virus and for developing new antibody-based therapeutics or detection methods.

  13. Complex forms of mitochondrial DNA in human B cells transformed by Epstein-Barr virus (EBV)

    DEFF Research Database (Denmark)

    Christiansen, Gunna; Christiansen, C; Zeuthen, J

    1983-01-01

    Human lymphocytes and lymphoid cell lines were analyzed for the presence of complex forms of mitochondrial DNA (mtDNA) by electron microscopy. A high frequency (9%-14.5%) of catenated dimers, circular dimers, or oligomers were found in samples from Epstein-Barr-virus-(EBV) transformed lymphoblast......Human lymphocytes and lymphoid cell lines were analyzed for the presence of complex forms of mitochondrial DNA (mtDNA) by electron microscopy. A high frequency (9%-14.5%) of catenated dimers, circular dimers, or oligomers were found in samples from Epstein-Barr-virus-(EBV) transformed...... lymphoblastoid cell lines. These complex forms of mtDNA were present in much lower frequencies in lymphocytes isolated from donor blood (1.3%-4.6%). Similar low frequencies were found with primary fibroblasts (1.1%) or freshly isolated monkey liver cells (2.1%). Samples from cultures of Burkitt lymphoma (BL......) cell lines of EBV-positive or -negative origin contained intermediate (5%-7%) frequencies of complex forms of mtDNA....

  14. Expression of SLAM (CD150) cell-surface receptors on human B-cell subsets: from pro-B to plasma cells.

    Science.gov (United States)

    De Salort, Jose; Sintes, Jordi; Llinàs, Laia; Matesanz-Isabel, Jessica; Engel, Pablo

    2011-01-30

    The SLAM (CD150) family receptors are leukocyte cell-surface glycoproteins involved in leukocyte activation. These molecules and their adaptor protein SAP contribute to the effective germinal center formation, generation of high-affinity antibody-secreting plasma cells, and memory B cells, thereby facilitating long-term humoral immune response. Multi-color flow cytometric analysis was performed to determine the expression of CD48 (SLAMF2), CD84 (SLAMF5), CD150 (SLAM or SLAMF1), CD229 (Ly9 or SLAMF3), CD244 (2B4 or SLAMF4), CD319 (CRACC, CS1, or SLAMF7), and CD352 (NTB-A or SLAMF6) on human cell lines and B-cell subsets. The following subsets were assessed: pro-B, pre-B, immature-B, and mature-B cells from bone marrow; transitional and B1/B2 subsets from peripheral blood; and naïve, pre-germinal center, germinal center, memory, plasmablasts, and plasma cells from tonsil and spleen. All receptors were expressed on B cells, with the exception of CD244. SLAM family molecules were widely distributed during B-cell development, maturation and terminal differentiation into plasmablasts and plasma cells, but their expression among various B-cell subsets differed significantly. Such heterogeneous expression patterns suggest that SLAM molecules play an essential and non-redundant role in the control of humoral immune responses. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Engagement of major histocompatibility complex class I and class II molecules up-regulates intercellular adhesion of human B cells via a CD11/CD18-independent mechanism.

    Science.gov (United States)

    Alcover, A; Juillard, V; Acuto, O

    1992-02-01

    We have studied the role of major histocompatibility complex (MHC) molecules in the regulation of intercellular adhesion of human B cells. We found that molecules able to bind to MHC class II molecules, such as monoclonal antibodies or staphylococcal enterotoxins, induced rapid and sustained homotypic adhesion of Epstein-Barr virus (EBV)-transformed B cell lines as well as peripheral blood B lymphocytes. Moreover, anti-MHC class I monoclonal antibodies also stimulated intercellular adherence. Adhesion induced upon MHC engagement was faster and stronger than that triggered by phorbol esters. It needed active metabolism, but divalent cations were not required. Monoclonal antibodies directed against LFA-1 (CD11a/CD18) or its ligand ICAM-1 (CD54) did not inhibit MHC class II-induced homotypic adhesion of various EBV-transformed B cell lines, nor of a variant of the B cell line Raji expressing very low LFA-1 surface levels. Moreover, EBV-transformed B cells from a severe lymphocyte adhesion deficiency patient, lacking surface CD11/CD18, also aggregated in response to anti-MHC class I or class II monoclonal antibodies. Together these data indicate that engagement of MHC molecules may transduce signals to B cells resulting in up-regulation of intercellular adhesion, via an LFA-1-independent mechanism. This may play a role in the stabilization of T cell/antigen-presenting cell conjugates at the moment of antigen recognition.

  16. Btk regulation in human and mouse B cells via protein kinase C phosphorylation of IBtkγ

    NARCIS (Netherlands)

    Janda, E.; Palmieri, C.; Pisano, A.; Pontoriero, M.; Iaccino, E.; Falcone, C.; Fiume, G.; Gaspari, M.; Nevolo, M.; Salle, E. Di; Rossi, A.; Laurentiis, A. de; Greco, A.; Napoli, D. Di; Verheij, E.; Britti, D.; Lavecchia, L.; Quinto, I.; Scala, G.

    2011-01-01

    The inhibitor of Bruton tyrosine kinase γ (IBtkγ) is a negative regulator of the Bruton tyrosine kinase (Btk), which plays a major role in B-cell differentiation; however, the mechanisms of IBtkγ-mediated regulation of Btk are unknown. Here we report that B-cell receptor (BCR) triggering caused

  17. SPECIFIC UPTAKE OF MONOCLONAL ANTIBODY-CONJUGATED METHOTREXATE BY HUMAN LYMPHOCYTIC LEUKEMIC B CELLS

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhenping; Yang Chunzheng; Tarunendu Ghose; Jaroslav Kralovec

    1998-01-01

    Objective: To analysis the uptake of free MTX and MTX conjugated to tumor specific monoclonal antibody by target and non-target cells. Methods: The folate antagonist methotrexate (MTX) was conjugated to two monoclonal antibodies (Mab) directed against human chronic lymphocytic leukemia (CLL), Dal B01 and Dal B02, by an active ester method. Both conjugates were more cytotoxic toward the target tumor cell line D10-1than to the non-target cell line MOLT-3, and Dal B02-MTX conjugate was more inhibitory to D10-1 cells than free MTX in a 6 h pulse exposure assay. Results: Drug uptake studies revealed that D10-1 cells took up much more Dal B01 and Dal B02-conjugated MTX than free MTX. The amounts of drug taken up by D10-1 cells incubated with Dal B01 and Dal B02-conjugated MTX were always 3 to 5-fold higher than that taken up by MOLT-3 cells, although the latter took up more drug when incubated with free MTX. Furthermore, tumor cells incubated with Dal B01 or Dal B02-conjugated MTX retained much larger amounts of drug for a prolonged period of time than those incubated with free MTX.Conclusion: The enhanced specific cytotoxicity of Dal B01 and Dal B02-MTX conjugates toward target tumor cells is therefore likely due to (Ⅰ) delivery of larger amounts of MTX to target cells when the drug is conjugated to Mab;(ii) longer retention of Mab-conjugated MTX by target cells; and (iii) slow, prolonged release of MTX from the surface-bound or endocytosed conjugates, rendering them into a sustained release dosage form.

  18. Identification of a human immunodominant B-cell epitope within the immunoglobulin A1 protease of Streptococcus pneumoniae

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    Felici Franco

    2007-12-01

    Full Text Available Abstract Background The IgA1 protease of Streptococcus pneumoniae is a proteolytic enzyme that specifically cleaves the hinge regions of human IgA1, which dominates most mucosal surfaces and is the major IgA isotype in serum. This protease is expressed in all of the known pneumococcal strains and plays a major role in pathogen's resistance to the host immune response. The present work was focused at identifying the immunodominant regions of pneumococcal IgA1 protease recognized by the human antibody response. Results An antigenic sequence corresponding to amino acids 420–457 (epiA of the iga gene product was identified by screening a pneumococcal phage display library with patients' sera. The epiA peptide is conserved in all pneumococci and in two out of three S. mitis strains, while it is not present in other oral streptococci so far sequenced. This epitope was specifically recognized by antibodies present in sera from 90% of healthy adults, thus representing an important target of the humoral response to S. pneumoniae and S. mitis infection. Moreover, sera from 68% of children less than 4 years old reacted with the epiA peptide, indicating that the human immune response against streptococcal antigens occurs during childhood. Conclusion The broad and specific recognition of the epiA polypeptide by human sera demonstrate that the pneumococcal IgA1 protease contains an immunodominant B-cell epitope. The use of phage display libraries to identify microbe or disease-specific antigens recognized by human sera is a valuable approach to epitope discovery.

  19. The rGel/BLyS Fusion Toxin Inhibits Diffuse Large B-cell Lymphoma Growth In Vitro and In Vivo

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    Mi-Ae Lyu

    2010-05-01

    Full Text Available Diffuse large B-cell lymphoma (DLBCL is an aggressive subtype of B-cell non-Hodgkin lymphoma (NHL and accounts for 30%to 40%of NHL. Molecules targeting nuclear factor-κB (NF-κB are expected to be of therapeutic value in those tumors where NF-κB seems to play a unique survival role such as activated B-cell (ABC-subtype DLBCL. We previously generated a rGel/BLyS fusion toxin for receptor-mediated delivery of the rGel toxin specifically to malignant B cells. In this study, we examined this fusion toxin for its ability to suppress DLBCL growth in vitro and in vivo. rGel/BLyS was specifically cytotoxic to DLBCL lines expressing all three BLyS receptors and constitutively active NF-κB. Treatment with rGel/BLyS induced down-regulation of the phosphorylation of inhibitory subunit of NF-κB (IκB-α, inhibition of NF-κB DNA-binding activity, and accumulation of IκB-α. In agreement with these results, we additionally found that rGel/BLyS downregulated levels of several NF-κB targets including Bcl-xL, Mcl-1, survivin, and x-chromosome linked inhibitor-of-apoptosis. Treatment also induced up-regulation of Bax and apoptosis through caspase-3 activation and poly ADP-ribose polymerase cleavage. Importantly, rGel/BLyS significantly inhibited tumor growth (P < .05 in a DLBCL xenograft model. Thus, our results indicate that rGel/BLyS is an excellent candidate for the treatment of aggressive NHLs that are both dependent on NF-κB and are resistant to conventional chemotherapeutic regimens.

  20. Effect of proline rich domain of an RNA-binding protein Sam68 in cell growth process, death and B cell signal transduction

    Institute of Scientific and Technical Information of China (English)

    LI Qing-hua; FAN Tian-xue; PANG Tian-xiang; YUAN Wen-su; HAN Zhong-chao

    2006-01-01

    Background Sam68 plays an important role as a multiple functional RNA binding nuclear protein in cell cycle progress, RNA usage, signal transduction, and tyrosine phosphorylation by Src during mitosis. However, its precise impact on these essential cellular functions remains unclear. The purpose of this study is to further elucidate Sam68 functions in RNA metabolism, signal transduction regulation of cell growth and cell proliferation in DT40 cell line.Methods By using gene targeting method, we isolated a mutation form of Sam68 in DT40 cells and described its effect on cell growth process and signal transduction. Southern, Northern, and Western blot, phosphorylation and flow-cytometfic analyses were performed to investigate the Sam68 functions.Results A slower growth rate (2.1 hours growth elongation) and longer S phase (1.7 hours elongation) was observed in the Sam68 mutant cells. Serum depletion resulted in increased amounts of dead cells, and expansion of S phase in mutant cells. Upon B cell cross-linking, the maximal level of tyrosine phosphorylation on BLNK was observed to be significantly lower in mutant cells.Conclusions The proline rich domain of Sam68 is involved in cell growth control by modulating the function of mRNAs in S phase or earlier and the functions as an adaptor molecule in B cell signal transduction pathways.

  1. High Inter-Individual Diversity of Point Mutations, Insertions, and Deletions in Human Influenza Virus Nucleoprotein-Specific Memory B Cells.

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    Sven Reiche

    Full Text Available The diversity of virus-specific antibodies and of B cells among different individuals is unknown. Using single-cell cloning of antibody genes, we generated recombinant human monoclonal antibodies from influenza nucleoprotein-specific memory B cells in four adult humans with and without preceding influenza vaccination. We examined the diversity of the antibody repertoires and found that NP-specific B cells used numerous immunoglobulin genes. The heavy chains (HCs originated from 26 and the kappa light chains (LCs from 19 different germ line genes. Matching HC and LC chains gave rise to 43 genetically distinct antibodies that bound influenza NP. The median lengths of the CDR3 of the HC, kappa and lambda LC were 14, 9 and 11 amino acids, respectively. We identified changes at 13.6% of the amino acid positions in the V gene of the antibody heavy chain, at 8.4% in the kappa and at 10.6 % in the lambda V gene. We identified somatic insertions or deletions in 8.1% of the variable genes. We also found several small groups of clonal relatives that were highly diversified. Our findings demonstrate broadly diverse memory B cell repertoires for the influenza nucleoprotein. We found extensive variation within individuals with a high number of point mutations, insertions, and deletions, and extensive clonal diversification. Thus, structurally conserved proteins can elicit broadly diverse and highly mutated B-cell responses.

  2. Affinity isolation of antigen-specific circulating B cells for generation of phage display-derived human monoclonal antibodies

    DEFF Research Database (Denmark)

    Ditzel, Henrik

    2009-01-01

    A method is described for affinity isolation of antigen-specific circulating B cells of interest for subsequent generation of immune antibody phage display libraries. This approach should overcome the problem of low yields of monoclonal antibodies of interest in the libraries generated from...... peripheral blood lymphocytes caused by the low abundance of antigen-specific B cells in the circulation. The preselection of B cells is based on the specificity of the surface Ig receptor and is accomplished using the antigen of interest conjugated to magnetic beads. This method should significantly increase...

  3. Analysis of antigenically important residues in human influenza A virus in terms of B-cell epitopes.

    Science.gov (United States)

    Lees, William D; Moss, David S; Shepherd, Adrian J

    2011-09-01

    In this paper we undertake an analysis of the antigenicity of influenza A virus hemagglutinin. We developed a novel computational approach to the identification of antigenically active regions and showed that the amino acid substitutions between successive predominant seasonal strains form clusters that are consistent, in terms of both their location and their size, with the properties of B-cell epitopes in general and with those epitopes that have been identified experimentally in influenza A virus hemagglutinin to date. Such an interpretation provides a biologically plausible framework for an understanding of the location of antigenically important substitutions that is more specific than the canonical "antigenic site" model and provides an effective basis for deriving models that predict antigenic escape in the H3N2 subtype. Our results support recent indications that antibodies binding to the "stalk" region of hemagglutinin are found in the human population and exert evolutionary pressure on the virus. Our computational approach provides a possible method for identifying antigenic escape through evolution in this region, which in some cases will not be identified by the hemagglutinin inhibition assay.

  4. Staphylococcus aureus α-toxin triggers the synthesis of B-cell lymphoma 3 by human platelets.

    Science.gov (United States)

    Schubert, Sebastian; Schwertz, Hansjörg; Weyrich, Andrew S; Franks, Zechariah G; Lindemann, Stephan; Otto, Monika; Behr, Hagen; Loppnow, Harald; Schlitt, Axel; Russ, Martin; Presek, Peter; Werdan, Karl; Buerke, Michael

    2011-02-01

    The frequency and severity of bacteremic infections has increased over the last decade and bacterial endovascular infections (i.e., sepsis or endocarditis) are associated with high morbidity and mortality. Bacteria or secreted bacterial products modulate platelet function and, as a result, affect platelet accumulation at sites of vascular infection and inflammation. However, whether bacterial products regulate synthetic events in platelets is not known. In the present study, we determined if prolonged contact with staphylococcal α-toxin signals platelets to synthesize B-cell lymphoma (Bcl-3), a protein that regulates clot retraction in murine and human platelets. We show that α-toxin induced α(IIb)β(3)-dependent aggregation (EC(50) 2.98 µg/mL ± 0.64 µg/mL) and, over time, significantly altered platelet morphology and stimulated de novo accumulation of Bcl-3 protein in platelets. Adherence to collagen or fibrinogen also increased the expression of Bcl-3 protein by platelets. α-toxin altered Bcl-3 protein expression patterns in platelets adherent to collagen, but not fibrinogen. Pretreatment of platelets with inhibitors of protein synthesis or the mammalian Target of Rapamycin (mTOR) decreased Bcl-3 protein expression in α-toxin stimulated platelets. In conclusion, Staphylococcusaureus-derived α-toxin, a pore forming exotoxin, exerts immediate (i.e., aggregation) and prolonged (i.e., protein synthesis) responses in platelets, which may contribute to increased thrombotic events associated with gram-positive sepsis or endocarditis.

  5. Chemopreventive action of Lygodium flexuosum extract in human hepatoma PLC/PRF/5 and Hep 3B cells.

    Science.gov (United States)

    Wills, P J; Asha, V V

    2009-03-18

    Lygodium flexuosum (Lygodiaceae), a medicinal fern used in Indian traditional medicine against liver disorders. The rationale of the study was to examine whether the n-hexane extract from plant Lygodium flexuosum affects apoptosis on human hepatoma PLC/PRF/5 and Hep 3B cells. Chemopreventive activity of the Lygodium flexuosum extract was determined by MTT assay, annexin-V FITC binding to phosphatidyl serine and cleavage of PARP. Subdiploid condition of cells treated with Lygodium flexuosum was analyzed by flow cytometry. Further, used transiently transfected NF-kappaB reporter in PLC/PRF/5 cells to evaluate the inhibitive effect of Lygodium flexuosum extract. Lygodium flexuosum extract inhibited the cell viability and induced apoptosis in hepatoma cells in a concentration dependent manner as evidenced by apoptotic changes such as flipping of phosphatidyl serine, cleavage of PARP. Cell cycle analysis showed the subG1 apoptotic population in cells treated with higher concentrations of the extract. When activated with exogenous TNF-alpha in transfected hepatoma cells it was observed that NF-kappaB dependent gene expression was inhibited by treatment with Lygodium flexuosum extract in PLC/PRF/5 cells dose-dependently. This investigation suggests that the Lygodium flexuosum extract has antiproliferative and apoptotic activity in both cancer cells and has inhibitive role in TNF-alpha induced NF-kappaB activation in PLC/PRF/5 cells confirms the potential of the extract as a chemopreventive agent.

  6. B-cell infiltration and frequency of cytokine producing cells differ between localized and disseminated human cutaneous leishmaniases

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    MGS Vieira

    2002-10-01

    Full Text Available Biopsies from human localized cutaneous lesions (LCL n = 7 or disseminated lesions (DL n = 8 cases were characterized according to cellular infiltration,frequency of cytokine (IFN-g, TNF-alpha or iNOS enzyme producing cells. LCL, the most usual form of the disease with usually one or two lesions, exhibits extensive tissue damage. DL is a rare form with widespread lesions throughout the body; exhibiting poor parasite containment but less tissue damage. We demonstrated that LCL lesions exhibit higher frequency of B lymphocytes and a higher intensity of IFN-gamma expression. In both forms of the disease CD8+ were found in higher frequency than CD4+ T cells. Frequency of TNF-alpha and iNOS producing cells, as well as the frequency of CD68+ macrophages, did not differ between LCL and DL. Our findings reinforce the link between an efficient control of parasite and tissue damage, implicating higher frequency of IFN-gamma producing cells, as well as its possible counteraction by infiltrated B cells and hence possible humoral immune response in situ.

  7. High basal expression of interferon-stimulated genes in human bronchial epithelial (BEAS-2B cells contributes to influenza A virus resistance.

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    Lai-Giea Seng

    Full Text Available Respiratory epithelial cells play a key role in influenza A virus (IAV pathogenesis and host innate response. Transformed human respiratory cell lines are widely used in the study of IAV-host interactions due to their relative convenience, and inherent difficulties in working with primary cells. Transformed cells, however, may have altered susceptibility to virus infection. Proper characterization of different respiratory cell types in their responses to IAV infection is therefore needed to ensure that the cell line chosen will provide results that are of relevance in vivo. We compared replication kinetics of human H1N1 (A/USSR/77 IAVs in normal primary human bronchial epithelial (NHBE and two commonly used respiratory epithelial cell lines namely BEAS-2B and A549 cells. We found that IAV replication was distinctly poor in BEAS-2B cells in comparison with NHBE, A549 and Madin-Darby canine kidney (MDCK cells. IAV resistance in BEAS-2B cells was accompanied by an activated antiviral state with high basal expression of interferon (IFN regulatory factor-7 (IRF-7, stimulator of IFN genes (STING and IFN stimulated genes (ISGs. Treatment of BEAS-2B cells with a pan-Janus-activated-kinase (JAK inhibitor decreased IRF-7 and ISG expression and resulted in increased IAV replication. Therefore, the use of highly resistant BEAS-2B cells in IAV infection may not reflect the cytopathogenicity of IAV in human epithelial cells in vivo.

  8. IL-21 and CD40L synergistically promote plasma cell differentiation through upregulation of Blimp-1 in human B cells1

    OpenAIRE

    Ding, B. Belinda; Bi, Enguang; Chen, Hongshan; Yu, J. Jessica; Ye, B. Hilda

    2013-01-01

    After undergoing Ig somatic hypermutation and antigen selection, germinal center (GC) B cells terminally differentiate into either memory or plasma cells (PCs). It is known that the CD40L and IL-21/STAT3 signaling pathways play critical roles in this process, yet it is unclear how the B cell transcription program interprets and integrates these two types of T cell derived signals. In this study, we characterized the role of STAT3 in the GC-associated PC differentiation using purified human to...

  9. Circulating human CD27-IgA+ memory-B cells recognize bacteria with polyreactive immunoglobulins1

    Science.gov (United States)

    Berkowska, Magdalena A.; Schickel, Jean-Nicolas; Grosserichter-Wagener, Christina; de Ridder, Dick; Ng, Yen Shing; van Dongen, Jacques J.M.; Meffre, Eric; van Zelm, Menno C.

    2015-01-01

    The vast majority of immunoglobulin (Ig)A production occurs in mucosal tissue following T-cell dependent and T-cell independent antigen responses. To study the nature of each of these responses, we analyzed the gene expression and Ig reactivity profiles of T-cell dependent CD27+IgA+ and T-cell independent CD27−IgA+ circulating memory-B cells. Gene expression profiles of IgA+ subsets were highly similar to each other and to IgG+ memory-B-cell subsets with typical upregulation of activation markers and downregulation of inhibitory receptors. However, we identified the mucosa-associated CCR9 and RUNX2 genes to be specifically upregulated in CD27−IgA+ B cells. We also found that CD27−IgA+ B cells expressed antibodies with distinct Ig repertoire and reactivity than those from CD27+IgA+ B cells. Indeed, antibodies from CD27−IgA+ B cells were weakly mutated, often utilized Igλ chain and were enriched in polyreactive clones recognizing various bacterial species. Hence, T-cell independent IgA responses are likely involved in the maintenance of gut homeostasis through the production of polyreactive mutated IgA antibodies with crossreactive anti-commensal reactivity. PMID:26150533

  10. Differential regulation of self-reactivity discriminates between IgG+ human circulating memory B cells and bone marrow plasma cells.

    Science.gov (United States)

    Scheid, Johannes F; Mouquet, Hugo; Kofer, Juliane; Yurasov, Sergey; Nussenzweig, Michel C; Wardemann, Hedda

    2011-11-01

    Long-term humoral immunity is maintained by the formation of high-affinity class-switched memory B cells and long-lived antibody-secreting plasma cells. In healthy humans, a substantial fraction of IgG-positive memory B cells express self-reactive and polyreactive IgG antibodies that frequently develop by somatic mutations. Whether self- and polyreactive IgG-secreting B cells are also tolerated in the long-lived plasma cell pool is not known. To address this question, we cloned and expressed the Ig genes from 177 IgG-producing bone marrow plasma cells of four healthy donors. All antibodies were highly mutated but the frequency of self- and polyreactive IgG antibodies was significantly lower than that found in circulating memory B cells. The data suggest that in contrast to the development of memory B cells, entry into the bone marrow plasma cell compartment requires previously unappreciated selective regulation by mechanisms that limit the production of self- and polyreactive serum IgG antibodies.

  11. Temporal gene expression profile of human precursor B leukemia cells induced by adhesion receptor: identification of pathways regulating B-cell survival.

    Science.gov (United States)

    Astier, Anne Laurence; Xu, Ronghui; Svoboda, Marek; Hinds, Esther; Munoz, Olivier; de Beaumont, Rosalie; Crean, Colin Daniel; Gabig, Theodore; Freedman, Arnold Stephen

    2003-02-01

    The physical interactions between B cells and stromal cells from the lymphoid tissue microenvironment are critical to the survival of normal and malignant B cells. They are principally mediated by integrins expressed on B cells and counterreceptors on stromal cells. Specifically, alpha4beta1 integrin engagement rescues B cells from physiological or drug-induced apoptosis. Therefore, in order to understand the mechanisms by which integrins prevent apoptosis in leukemia B cells, we compared the temporal gene expression profiles induced by beta1-integrin ligation with fibronectin (Fn) or adhesion by poly-L-Lysine in serum-starved precursor B leukemia cells. Among the 38 selected differentially expressed genes, 6 genes involved in adhesion (VAV2, EPB41L1, CORO1A), proliferation (FRAP1, CCT4), and intercellular communication (GJB3) were validated by real-time quantitative polymerase chain reaction (RT-Q-PCR). Gene expression modulation could also be validated at the protein level for 5 other genes. We show that integrin stimulation up-regulated FBI-1 expression but inhibited CD79a, Requiem, c-Fos, and caspase 7 induction when the cells underwent apoptosis. We further demonstrate that Fn stimulation also inhibits caspase 3 activation but increases XIAP and survivin expression. Moreover, integrin stimulation also prevents caspase activation induced by doxorubicin. Therefore, we identified genes modulated by adhesion of human precursor B leukemia cells that regulate proliferation and apoptosis, highlighting new pathways that might provide insights into future therapy aiming at targeting apoptosis of leukemia cells.

  12. Differential Effects of Escherichia coli Nissle and Lactobacillus rhamnosus Strain GG on Human Rotavirus Binding, Infection, and B Cell Immunity.

    Science.gov (United States)

    Kandasamy, Sukumar; Vlasova, Anastasia N; Fischer, David; Kumar, Anand; Chattha, Kuldeep S; Rauf, Abdul; Shao, Lulu; Langel, Stephanie N; Rajashekara, Gireesh; Saif, Linda J

    2016-02-15

    Rotavirus (RV) causes significant morbidity and mortality in children worldwide. The intestinal microbiota plays an important role in modulating host-pathogen interactions, but little is known about the impact of commonly used probiotics on human RV (HRV) infection. In this study, we compared the immunomodulatory effects of Gram-positive (Lactobacillus rhamnosus strain GG [LGG]) and Gram-negative (Escherichia coli Nissle [EcN]) probiotic bacteria on virulent human rotavirus (VirHRV) infection and immunity using neonatal gnotobiotic piglets. Gnotobiotic piglets were colonized with EcN, LGG, or EcN+LGG or uncolonized and challenged with VirHRV. Mean peak virus shedding titers and mean cumulative fecal scores were significantly lower in EcN-colonized compared with LGG-colonized or uncolonized piglets. Reduced viral shedding titers were correlated with significantly reduced small intestinal HRV IgA Ab responses in EcN-colonized compared with uncolonized piglets post-VirHRV challenge. However the total IgA levels post-VirHRV challenge in the intestine and pre-VirHRV challenge in serum were significantly higher in EcN-colonized than in LGG-colonized piglets. In vitro treatment of mononuclear cells with these probiotics demonstrated that EcN, but not LGG, induced IL-6, IL-10, and IgA, with the latter partially dependent on IL-10. However, addition of exogenous recombinant porcine IL-10 + IL-6 to mononuclear cells cocultured with LGG significantly enhanced IgA responses. The greater effectiveness of EcN in moderating HRV infection may also be explained by the binding of EcN but not LGG to Wa HRV particles or HRV 2/4/6 virus-like particles but not 2/6 virus-like particles. Results suggest that EcN and LGG differentially modulate RV infection and B cell responses.

  13. B cell subsets in atherosclerosis

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    Heather M. Perry

    2012-12-01

    Full Text Available 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.

  14. IL-6 triggers IL-21 production by human CD4+ T cells to drive STAT3-dependent plasma cell differentiation in B cells.

    Science.gov (United States)

    Diehl, Sean A; Schmidlin, Heike; Nagasawa, Maho; Blom, Bianca; Spits, Hergen

    2012-09-01

    Interleukin (IL)-21-producing CD4(+)T cells are central to humoral immunity. Deciphering the signals that induce IL-21 production in CD4(+) T cells and those triggered by IL-21 in B cells are, therefore, of importance for understanding the generation of antibody (Ab) responses. Here, we show that IL-6 increased IL-21 production by human CD4(+) T cells, particularly in those that express the transcriptional regulator B cell lymphoma (BCL)6, which is required in mice for the development of C-X-C chemokine receptor type 5 (CXCR5(+)) IL-21-producing T follicular helper (T(FH)) cells. However, retroviral overexpression of BCL6 in total human CD4(+) T cells only transiently increased CXCR5, the canonical T(FH)-defining surface marker. We show here that IL-21 was required for the induction of Ab production by IL-6. In IL-21-treated B cells, signal transducer and activator of transcription (STAT)3 was required for optimal immunoglobulin production and upregulation of PR domain containing 1 (PRDM1(+)), the master plasma cell factor. These results, therefore, demonstrate the critical importance of STAT3 activation in B cells during IL-21-driven humoral immunity and suggest that BCL6 expression, although not sufficient, may serve as a platform for the acquisition of a T(FH)-like phenotype by human CD4(+) T cells.

  15. High serum vascular endothelial growth factor level is an adverse prognostic factor for high-risk diffuse large B-cell lymphoma patients treated with dose-dense chemoimmunotherapy

    DEFF Research Database (Denmark)

    Riihijärvi, Sari; Nurmi, Heidi; Holte, Harald;

    2012-01-01

    To determine whether serum vascular endothelial growth factor (s-VEGF) levels and VEGF gene expression in tumor tissue predict survival of diffuse large B-cell lymphoma (DLBCL) patients treated with chemoimmunotherapy....

  16. Piper betle leaf extracts induced human hepatocellular carcinoma Hep3B cell death via MAPKs regulating the p73 pathway in vitro and in vivo.

    Science.gov (United States)

    Wu, Pei-Fang; Tseng, Hsien-Chun; Chyau, Charng-Cherng; Chen, Jing-Hsien; Chou, Fen-Pi

    2014-12-01

    Extracts of Piper betle leaf (PBLs) are rich in bioactive compounds with potential chemopreventive ability. In this study, Hep3B cells which are p53 null were used to investigate the anti-tumor effect of PBLs in the cell and in the xenograft model. The results revealed that PBLs (0.1 to 1 mg mL(-1)) induced a dose- and time-dependent increase of cell toxicity. The underlying mechanisms as evidenced by flow cytometry and western blot analysis showed that PBLs triggered ATM, cAbl, and p73 expressions and activated JNK and p38 pathways that subsequently led to cell cycle arrest and mitochondria-dependent apoptosis. PBLs also inhibited tumor growth in Hep3B-bearing mice via inducing the MAPK-p73 pathway. Our results demonstrated the in vitro and in vivo anti-tumor potential of PBLs, supporting their application as a novel chemopreventive agent for the treatment of human hepatocellular carcinoma (HCC) in the future via targeting the p73 pathway.

  17. B-cell depletion is protective against anti-AAV capsid immune response: a human subject case study

    Directory of Open Access Journals (Sweden)

    M Corti

    2014-01-01

    Full Text Available Gene therapy strategies for congenital myopathies may require repeat administration of adeno-associated viral (AAV vectors due to aspects of the clinical application, such as: (i administration of doses below therapeutic efficacy in patients enrolled in early phase clinical trials; (ii progressive reduction of the therapeutic gene expression over time as a result of increasing muscle mass in patients treated at a young age; and (iii a possibly faster depletion of pathogenic myofibers in this patient population. Immune response triggered by the first vector administration, and to subsequent doses, represents a major obstacle for successful gene transfer in young patients. Anti-capsid and anti-transgene product related humoral and cell-mediated responses have been previously observed in all preclinical models and human subjects who received gene therapy or enzyme replacement therapy (ERT for congenital myopathies. Immune responses may result in reduced efficacy of the gene transfer over time and/or may preclude for the possibility of re-administration of the same vector. In this study, we evaluated the immune response of a Pompe patient dosed with an AAV1-GAA vector after receiving Rituximab and Sirolimus to modulate reactions against ERT. A key finding of this single subject case report is the observation that B-cell ablation with rituximab prior to AAV vector exposure results in non-responsiveness to both capsid and transgene, therefore allowing the possibility of repeat administration in the future. This observation is significant for future gene therapy studies and establishes a clinically relevant approach to blocking immune responses to AAV vectors.

  18. Identification of continuous human B-cell epitopes in the envelope glycoprotein of dengue virus type 3 (DENV-3.

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    Andréa N M Rangel da Silva

    Full Text Available BACKGROUND: Dengue virus infection is a growing global public health concern in tropical and subtropical regions of the world. Dengue vaccine development has been hampered by concerns that cross-reactive immunological memory elicited by a candidate vaccine could increase the risk of development of more severe clinical forms. One possible strategy to reduce risks associated with a dengue vaccine is the development of a vaccine composed of selected critical epitopes of each of the serotypes. METHODOLOGY/PRINCIPAL FINDINGS: Synthetic peptides were used to identify B-cell epitopes in the envelope (E glycoprotein of dengue virus type 3 (DENV-3. Eleven linear, immunodominant epitopes distributed in five regions at amino acid (aa positions: 51-65, 71-90, 131-170, 196-210 and 246-260 were identified by employing an enzyme- linked immunosorbent assay (ELISA, using a pool of human sera from dengue type 3 infected individuals. Peptides 11 (aa51-65, 27 and 28 (aa131-150 also reacted with dengue 1 (DENV-1 and dengue 2 (DENV-2 patient sera as analyzed through the ROC curves generated for each peptide by ELISA and might have serotype specific diagnostic potential. Mice immunized against each one of the five immunogenic regions showed epitopes 51-65, 131-170, 196-210 and 246-260 elicited the highest antibody response and epitopes131-170, 196-210 and 246-260, elicited IFN-gamma production and T CD4+ cell response, as evaluated by ELISA and ELISPOT assays respectively. CONCLUSIONS/SIGNIFICANCE: Our study identified several useful immunodominant IgG-specific epitopes on the envelope of DENV-3. They are important tools for understanding the mechanisms involved in antibody dependent enhancement and immunity. If proven protective and safe, in conjunction with others well-documented epitopes, they might be included into a candidate epitope-based vaccine.

  19. IL-7 activates the phosphatidylinositol 3-kinase/AKT pathway in normal human thymocytes but not normal human B cell precursors.

    Science.gov (United States)

    Johnson, Sonja E; Shah, Nisha; Bajer, Anna A; LeBien, Tucker W

    2008-06-15

    IL-7 signaling culminates in different biological outcomes in distinct lymphoid populations, but knowledge of the biochemical signaling pathways in normal lymphoid populations is incomplete. We analyzed CD127/IL-7Ralpha expression and function in normal (nontransformed) human thymocytes, and human CD19(+) B-lineage cells purified from xenogeneic cord blood stem cell/MS-5 murine stromal cell cultures, to further clarify the role of IL-7 in human B cell development. IL-7 stimulation of CD34(+) immature thymocytes led to phosphorylation (p-) of STAT5, ERK1/2, AKT, and glycogen synthase kinase-3 beta, and increased AKT enzymatic activity. In contrast, IL-7 stimulation of CD34(-) thymocytes (that included CD4(+)/CD8(+) double-positive, and CD4(+) and CD8(+) single-positive cells) only induced p-STAT5. IL-7 stimulation of CD19(+) cells led to robust induction of p-STAT5, but minimal induction of p-ERK1/2 and p-glycogen synthase kinase-3 beta. However, CD19(+) cells expressed endogenous p-ERK1/2, and when rested for several hours following removal from MS-5 underwent de-phosphorylation of ERK1/2. IL-7 stimulation of rested CD19(+) cells resulted in robust induction of p-ERK1/2, but no induction of AKT enzymatic activity. The use of a specific JAK3 antagonist demonstrated that all IL-7 signaling pathways in CD34(+) thymocytes and CD19(+) B-lineage cells were JAK3-dependent. We conclude that human CD34(+) thymocytes and CD19(+) B-lineage cells exhibit similarities in activation of STAT5 and ERK1/2, but differences in activation of the PI3K/AKT pathway. The different induction of PI3K/AKT may at least partially explain the different requirements for IL-7 during human T and B cell development.

  20. Homeostatic 'bystander' proliferation of human peripheral blood B cells in response to polyclonal T-cell stimulation in vitro.

    Science.gov (United States)

    Jasiulewicz, Aleksandra; Lisowska, Katarzyna A; Pietruczuk, Krzysztof; Frąckowiak, Joanna; Fulop, Tamas; Witkowski, Jacek M

    2015-11-01

    The mechanisms of maintenance of adequate numbers of B lymphocytes and of protective levels of immunoglobulins in the absence of antigenic (re)stimulation remain not fully understood. Meanwhile, our results presented here show that both peripheral blood naive and memory B cells can be activated strongly and non-specifically (in a mitogen-like fashion) in 5-day in vitro cultures of anti-CD3- or concanavalin A (Con A)-stimulated peripheral blood mononuclear cells of healthy people. This polyclonal, bystander activation of the B cells includes multiple divisions of most of them (assessed here by the flow cytometric technique of dividing cell tracking) and significant antibody [immunoglobulin M (IgM) and IgG] secretion. Observed proliferation of the CD19(+) B cells depends on contact with stimulated T helper (Th) cells (via CD40-CD40L interaction) and on the response of B cells to secreted interleukins IL-5, IL-10 and IL-4, and is correlated with the levels of these Th-derived molecules, while it does not involve the ligation of the BCR/CD19 complex. We suggest that the effect might reflect the situation occurring in vivo as the homeostatic proliferation of otherwise non-stimulated, peripheral B lymphocytes, providing an always ready pool for efficient antibody production to any new (or cognate) antigen challenge.

  1. Impact of the B Cell Growth Factor APRIL on the Qualitative and Immunological Characteristics of Atherosclerotic Plaques.

    Science.gov (United States)

    Bernelot Moens, Sophie J; van Leuven, Sander I; Zheng, Kang H; Havik, Stefan R; Versloot, Miranda V; van Duivenvoorde, Leonie M; Hahne, Michael; Stroes, Erik S G; Baeten, Dominique L; Hamers, Anouk A J

    2016-01-01

    Studies on the role of B lymphocytes in atherosclerosis development, have yielded contradictory results. Whereas B lymphocyte-deficiency aggravates atherosclerosis in mice; depletion of mature B lymphocytes reduces atherosclerosis. These observations led to the notion that distinct B lymphocyte subsets have different roles. B1a lymphocytes exert an atheroprotective effect, which has been attributed to secretion of IgM, which can be deposited in atherosclerotic lesions thereby reducing necrotic core formation. Tumor necrosis factor (TNF)-family member 'A Proliferation-Inducing Ligand' (APRIL, also known as TNFSF13) was previously shown to increase serum IgM levels in a murine model. In this study, we investigated the effect of APRIL overexpression on advanced lesion formation and composition, IgM production and B cell phenotype. We crossed APRIL transgenic (APRIL-Tg) mice with ApoE knockout (ApoE-/-) mice. After a 12-week Western Type Diet, ApoE-/-APRIL-Tg mice and ApoE-/- littermates showed similar increases in body weight and lipid levels. Histologic evaluation showed no differences in lesion size, stage or necrotic area. However, smooth muscle cell (α-actin stain) content was increased in ApoE-/-APRIL-Tg mice, implying more stable lesions. In addition, increases in both plaque IgM deposition and plasma IgM levels were found in ApoE-/-APRIL-Tg mice compared with ApoE-/- mice. Flow cytometry revealed a concomitant increase in peritoneal B1a lymphocytes in ApoE-/-APRIL-Tg mice. This study shows that ApoE-/-APRIL-Tg mice have increased oxLDL-specific serum IgM levels, potentially mediated via an increase in B1a lymphocytes. Although no differences in lesion size were found, transgenic ApoE-/-APRIL-Tg mice do show potential plaque stabilizing features in advanced atherosclerotic lesions.

  2. Phylogenetic and functional analyses of a plant protein related to human B-cell receptor-associated proteins.

    Science.gov (United States)

    Atabekova, Anastasia K; Pankratenko, Anna V; Makarova, Svetlana S; Lazareva, Ekaterina A; Owens, Robert A; Solovyev, Andrey G; Morozov, Sergey Y

    2017-01-01

    Human B-cell receptor-associated protein BAP31 (HsBAP31) is the endoplasmic reticulum-resident protein involved in protein sorting and transport as well as pro-apoptotic signaling. Plant orthologs of HsBAP31 termed 'plant BAP-like proteins' (PBL proteins) have thus far remained unstudied. Recently, the PBL protein from Nicotiana tabacum (NtPBL) was identified as an interactor of Nt-4/1, a plant protein known to interact with plant virus movement proteins and affect the long-distance transport of potato spindle tuber viroid (PSTVd) via the phloem. Here, we have compared the sequences of PBL proteins and studied the biochemical properties of NtPBL. Analysis of a number of fully sequenced plant genomes revealed that PBL-encoding genes represent a small multigene family with up to six members per genome. Two conserved motifs were identified in the C-terminal region of PBL proteins. The NtPBL C-terminal hydrophilic region (NtPBL-C) was expressed in bacterial cells, purified, and used for analysis of its RNA binding properties in vitro. In gel shift experiments, NtPBL-C was found to bind several tested RNAs, showing the most efficient binding to microRNA precursors (pre-miRNA) and less efficient interaction with PSTVd. Mutational analysis suggested that NtPBL-C has a composite RNA-binding site, with two conserved lysine residues in the most C-terminal protein region being involved in binding of pre-miRNA but not PSTVd RNA. Virus-mediated transient expression of NtPBL-C in plants resulted in stunting and leaf malformation, developmental abnormalities similar to those described previously for blockage of miRNA biogenesis/function. We hypothesize that the NtPBL protein represents a previously undiscovered component of the miRNA pathway. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  3. Impact of 1.8-GHz radiofrequency radiation (RFR) on DNA damage and repair induced by doxorubicin in human B-cell lymphoblastoid cells.

    Science.gov (United States)

    Zhijian, Chen; Xiaoxue, Li; Yezhen, Lu; Shijie, Chen; Lifen, Jin; Jianlin, Lou; Deqiang, Lu; Jiliang, He

    2010-01-01

    In the present in vitro study, a comet assay was used to determine whether 1.8-GHz radiofrequency radiation (RFR, SAR of 2W/kg) can influence DNA repair in human B-cell lymphoblastoid cells exposed to doxorubicin (DOX) at the doses of 0microg/ml, 0.05microg/ml, 0.075microg/ml, 0.10microg/ml, 0.15microg/ml and 0.20microg/ml. The combinative exposures to RFR with DOX were divided into five categories. DNA damage was detected at 0h, 6h, 12h, 18h and 24h after exposure to DOX via the comet assay, and the percent of DNA in the tail (% tail DNA) served as the indicator of DNA damage. The results demonstrated that (1) RFR could not directly induce DNA damage of human B-cell lymphoblastoid cells; (2) DOX could significantly induce DNA damage of human B-cell lymphoblastoid cells with the dose-effect relationship, and there were special repair characteristics of DNA damage induced by DOX; (3) E-E-E type (exposure to RFR for 2h, then simultaneous exposure to RFR and DOX, and exposure to RFR for 6h, 12h, 18h and 24h after exposure to DOX) combinative exposure could obviously influence DNA repair at 6h and 12h after exposure to DOX for four DOX doses (0.075microg/ml, 0.10microg/ml, 0.15microg/ml and 0.20microg/ml) in human B-cell lymphoblastoid cells. Copyright 2009 Elsevier B.V. All rights reserved.

  4. Comparative Analysis of Toxic Responses of Organic Extracts from Diesel and Selected Alternative Fuels Engine Emissions in Human Lung BEAS-2B Cells

    OpenAIRE

    Helena Libalova; Pavel Rossner; Kristyna Vrbova; Tana Brzicova; Jitka Sikorova; Michal Vojtisek-Lom; Vit Beranek; Jiri Klema; Miroslav Ciganek; Jiri Neca; Katerina Pencikova; Miroslav Machala; Jan Topinka

    2016-01-01

    This study used toxicogenomics to identify the complex biological response of human lung BEAS-2B cells treated with organic components of particulate matter in the exhaust of a diesel engine. First, we characterized particles from standard diesel (B0), biodiesel (methylesters of rapeseed oil) in its neat form (B100) and 30% by volume blend with diesel fuel (B30), and neat hydrotreated vegetable oil (NEXBTL100). The concentration of polycyclic aromatic hydrocarbons (PAHs) and their derivatives...

  5. Comparative analysis of toxic responses of organic extracts from diesel and selected alternative fuels engine emissions in human lung BEAS-2B cells

    OpenAIRE

    Líbalová, Helena; Rossner, Pavel, Jr.; Vrbová, Kristýna; Brzicová, Táňa; Sikorová, Jitka; Vojtíšek-Lom, Michal; Beranek, Vít; Kléma, Jiří; Ciganek,Miroslav; Neča, Jiří; Pěnčíková, Kateřina; Machala, Miroslav; Topinka, Jan

    2016-01-01

    This study used toxicogenomics to identify the complex biological response of human lung BEAS-2B cells treated with organic components of particulate matter in the exhaust of a diesel engine. First, we characterized particles from standard diesel (B0), biodiesel (methylesters of rapeseed oil) in its neat form (B100) and 30% by volume blend with diesel fuel (B30), and neat hydrotreated vegetable oil (NEXBTL100). The concentration of polycyclic aromatic hydrocarbons (PAHs) and their derivatives...

  6. In vitro infection with HIV enables human CD4+ T cell clones to induce noncognate contact-dependent polyclonal B cell activation.

    Science.gov (United States)

    Macchia, D; Parronchi, P; Piccinni, M P; Simonelli, C; Mazzetti, M; Ravina, A; Milo, D; Maggi, E; Romagnani, S

    1991-05-15

    Eleven (nine CD4+ and two CD8+) protein purified derivative-specific and eight tetanus toxoid-specific T cell clones (TCC), established from the peripheral blood of healthy persons, were cocultured in vitro with irradiated mononuclear cells from patients infected by HIV in the presence of PHA and polybrene. Two weeks post-HIV exposure, all 17 CD4+, but neither of the two CD8+, TCC exhibited integration of HIV in their genoma, as detected by polymerase chain reaction analysis, and released HIV into their supernatants, as detected by measuring both reverse transcriptase activity and p24 Ag. When co-cultured with either autologous or allogeneic B cells, all CD4+ HIV-infected TCC induced the synthesis of extraordinarily high amounts of IgM, IgG, and IgA. In contrast, their noninfected counterparts could provide helper function for Ig synthesis by autologous B cells only in the presence of the specific Ag (or anti-CD3 antibody), and induced allogeneic B cells to synthesize Ig only upon stimulation with anti-CD3 antibody. The supernatants of HIV-infected TCC failed to stimulate Ig synthesis in B cells. More importantly, when HIV-infected clonal T blasts and B cells were cultured in different chambers separated by a millipore membrane, permeable to molecules but not to cells, Ig synthesis did not occur. The Ig synthesis induced by HIV-infected TCC was also markedly inhibited by the addition in culture of either anti-CD4 or anti-LFA-1 antibody. In contrast, HIV-infected TCC maintained their ability to provide helper function for Ig synthesis in the absence of any stimulus, even after fixation with p-formaldehyde. These data demonstrate that in vitro infection with HIV enables human T cells to stimulate Ig synthesis by B cells by an Ag-nonspecific, MHC-unrestricted, contact-dependent mechanism. This may explain, at least in part, the hypergammaglobulinemia and other phenomena related to polyclonal B cell activation frequently seen in HIV-infected persons.

  7. Rationale for B cell targeting in SLE

    Science.gov (United States)

    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

  8. Stepwise prediction and statistical screening: B-cell epitopes on neuraminidase of human avian H5N1 virus

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; YU ShouYi; KE ChangWen

    2008-01-01

    The B-cell epitopes of virus are associated with the antiviral drug and the vaccine screening. As the nucleotide sequences of neuraminidase (NA) of stain GD-01-06 were sequenced, we predicted the α-helix and β-fold structure and the indexes of the flexible regions of secondary structure of NA with methods of the Hydrophilicity plot by Kyte-Doolittle, the Surface probability plot by Emini and the Antigenic index by Jameson-Wolf, and then screened statistically the parameters to predict B-cell epitopes by the Hierarchical cluster and the Bivariate correlation and the quartiles with SPSS 13.0. The impact of variation of amino acids in NA on its epitopes was analyzed. The predictive results were evaluated by Wu's Antigenic Index and SWISS-MODEL. We found that the most possible epitopes on NA were located within or nearby its N-terminal Nos. 120-137, 81 -84, 408-415, 273-282, 429-432,356-368, 46-55,146-155, 341-350 and 198-209, which were the dominant regions of NA epitopes.Peptide 120-137 including the glycoprotein domain (NGT(126-128)) was first chosen as the B-cell epitopes on NA. NA in H5N1 strain isolated after 2003 lacked in No. 53 amino acid (I), resulting in an increase in the surface flexible region of NA in GD-01-06 and an enlargement to their epitope regions (VEP(46-48→VEPISNTNFL(46-55)). Conclusively, prediction of the B-cell epitopes on the NA based on multiple parameters is useful for researches on the molecular immunology and drug screening and immuno-prophylaxis. A deletion of No. 53 amino acid (I) in NA in strain GD-01-06 might increase its antigenicity.

  9. Integration of Proteomics and Transcriptomics Data Sets for the Analysis of a Lymphoma B-Cell Line in the Context of the Chromosome-Centric Human Proteome Project.

    Science.gov (United States)

    Díez, Paula; Droste, Conrad; Dégano, Rosa M; González-Muñoz, María; Ibarrola, Nieves; Pérez-Andrés, Martín; Garin-Muga, Alba; Segura, Víctor; Marko-Varga, Gyorgy; LaBaer, Joshua; Orfao, Alberto; Corrales, Fernando J; De Las Rivas, Javier; Fuentes, Manuel

    2015-09-04

    A comprehensive study of the molecular active landscape of human cells can be undertaken to integrate two different but complementary perspectives: transcriptomics, and proteomics. After the genome era, proteomics has emerged as a powerful tool to simultaneously identify and characterize the compendium of thousands of different proteins active in a cell. Thus, the Chromosome-centric Human Proteome Project (C-HPP) is promoting a full characterization of the human proteome combining high-throughput proteomics with the data derived from genome-wide expression profiling of protein-coding genes. Here we present a full proteomic profiling of a human lymphoma B-cell line (Ramos) performed using a nanoUPLC-LTQ-Orbitrap Velos proteomic platform, combined to an in-depth transcriptomic profiling of the same cell type. Data are available via ProteomeXchange with identifier PXD001933. Integration of the proteomic and transcriptomic data sets revealed a 94% overlap in the proteins identified by both -omics approaches. Moreover, functional enrichment analysis of the proteomic profiles showed an enrichment of several functions directly related to the biological and morphological characteristics of B-cells. In turn, about 30% of all protein-coding genes present in the whole human genome were identified as being expressed by the Ramos cells (stable average of 30% genes along all the chromosomes), revealing the size of the protein expression-set present in one specific human cell type. Additionally, the identification of missing proteins in our data sets has been reported, highlighting the power of the approach. Also, a comparison between neXtProt and UniProt database searches has been performed. In summary, our transcriptomic and proteomic experimental profiling provided a high coverage report of the expressed proteome from a human lymphoma B-cell type with a clear insight into the biological processes that characterized these cells. In this way, we demonstrated the usefulness of

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

    Directory of Open Access Journals (Sweden)

    Huixin Liu

    2016-01-01

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

  11. Retinoic acid-induced IgG production in TLR-activated human primary B cells involves ULK1-mediated autophagy.

    Science.gov (United States)

    Eriksen, Agnete Bratsberg; Torgersen, Maria Lyngaas; Holm, Kristine Lillebø; Abrahamsen, Greger; Spurkland, Anne; Moskaug, Jan Øivind; Simonsen, Anne; Blomhoff, Heidi Kiil

    2015-01-01

    In the present study we have established a vital role of autophagy in retinoic acid (RA)-induced differentiation of toll-like receptor (TLR)-stimulated human B cells into Ig-secreting cells. Thus, RA enhanced autophagy in TLR9- and CD180-stimulated peripheral blood B cells, as revealed by increased levels of the autophagosomal marker LC3B-II, enhanced colocalization between LC3B and the lysosomal marker Lyso-ID, by a larger percentage of cells with more than 5 characteristic LC3B puncta, and by the concomitant reduction in the level of SQSTM1/p62. Furthermore, RA induced expression of the autophagy-inducing protein ULK1 at the transcriptional level, in a process that required the retinoic acid receptor RAR. By inhibiting autophagy with specific inhibitors or by knocking down ULK1 by siRNA, the RA-stimulated IgG production in TLR9- and CD180-mediated cells was markedly reduced. We propose that the identified prominent role of autophagy in RA-mediated IgG-production in normal human B cells provides a novel mechanism whereby vitamin A exerts its important functions in the immune system.

  12. Cell enrichment-free massive ex-vivo expansion of peripheral CD20⁺ B cells via CD40-CD40L signals in non-human primates.

    Science.gov (United States)

    Kim, Jung-Sik; Byun, Nari; Chung, Hyunwoo; Kim, Hyun-Je; Kim, Jong-Min; Chun, Taehoon; Lee, Won-Woo; Park, Chung-Gyu

    2016-04-22

    Non-human primates (NHPs) are valuable as preclinical resources that bridge the gap between basic science and clinical application. B cells from NHPs have been utilized for the development of B-cell targeted drugs and cell-based therapeutic modalities; however, few studies on the ex-vivo expansion of monkey B cells have been reported. In this study, we developed a highly efficient ex-vivo expansion protocol for monkey B cells resulting in 99% purity without the requirement for prior cell-enrichment procedures. To this end, monkey peripheral blood mononuclear cells (PBMCs) were stimulated for 12 days with cells constitutively expressing monkey CD40L in expansion medium optimized for specific and massive expansion of B cells. The B cells expansion rates obtained were 2-5 times higher than those previously reported in humans, with rates ranging from 7.9 to 16.6 fold increase. Moreover, expanded B cells sustained high expression of co-stimulatory molecules including CD83 and CD86 until day 12 of culture, and the simple application of a brief centrifugation resulted in a CD20(+) B cell purity rate of greater than 99%. Furthermore, small amounts of CD3(+)CD20(+)BT-like cells were generated and CD16 was expressed at moderate levels on expanded B cells. Thus, the establishment of this protocol provides a method to produce quantities of homogeneous, mature B cells in numbers sufficient for the in vitro study of B cell immunity as well as for the development of B cell-diagnostic tools and cell-based therapeutic modalities.

  13. B cell helper assays.

    Science.gov (United States)

    Abrignani, Sergio; Tonti, Elena; Casorati, Giulia; Dellabona, Paolo

    2009-01-01

    Activation, proliferation and differentiation of naïve B lymphocytes into memory B cells and plasma cells requires engagement of the B cell receptor (BCR) coupled to T-cell help (1, 2). T cells deliver help in cognate fashion when they are activated upon recognition of specific MHC-peptide complexes presented by B cells. T cells can also deliver help in a non-cognate or bystander fashion, when they do not find specific MHC-peptide complexes on B cells and are activated by alternative mechanisms. T-cell dependent activation of B cells can be studied in vitro by experimental models called "B cell helper assays" that are based on the co-culture of B cells with activated T cells. These assays allow to decipher the molecular bases for productive T-dependent B cell responses. We show here examples of B cell helper assays in vitro, which can be reproduced with any subset of T lymphocytes that displays the appropriate helper signals.

  14. Rapid de novo generation of antigen specific human B cells with expression of Blimp-1 and AID by in vitro immunization.

    Science.gov (United States)

    Fang, Xu; Tong, Yue; Tian, Hong; Ning, Hongyu; Gao, Xiangdong; Yao, Wenbing

    2017-03-01

    In vitro immunization with antigens and cytokines triggers specific human B-cell response in short periods and is therefore superior to conventional in vivo immunization for antibody development. However, this new technology is limited by low efficiency, poor reproducibility, and requirement of pre-immunized lymphocytes. In this study, we demonstrate a novel method for de novo inducing antigen-specific human B cells in vitro. Unlike previous in vitro immunization of unfractionated PBMCs, we firstly optimized the conditions for inducing monocyte-derived dendritic cells (DCs) to efficiently capture, process, and present antigens. Instead of using the conventional method to activate Th2 cells for in vitro immunization, we succeeded to differentiate naïve CD4(+) T cells into T follicular helper (Tfh) cells using antigen-sensitized DCs and cytokine cocktail. We discovered the differentiated T cells expressed ICOS, PD-1, BCL-6, and IL-21 at high levels. After 12 days of T-B co-culture, we observed induced T cells efficiently promoted naïve B cells to differentiate into plasmablasts secreting antigen-specific antibodies, with expression of Blimp-1 and AID related to affinity maturation and class switching. Thus, we established a new co-culture system with naïve lymphocyte populations for de novo acquisition of specifically in vitro immunized B cells potentially for development of therapeutic antibodies, which also provides novel insights into understanding the complex interactions among immune cells in lymph nodes. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    included homogenization, isolation of mononuclear cells, MFC and FACS sorting using multicolour fluorescence single tube panels.of antibodies against surface molecules as CD10/20/27/38/45, supplemented with tissue related antibodies. Isolated B-cell subpopulations were evaluated by morphological inspection......, naïve, centroblast, centrocyte, memory, and plasmablasts. The identity of the tonsillar subpopulations was verified using qRT-PCR and exon microarray GEP based on the used discriminative phenotypic markers as well as transcriptions factors BACH2, BCL6, PAX5, IRF4, P27, PRDM1 and XBP1. Globally, the B...

  16. Increased ability of peripheral blood B cells from patients with rheumatoid arthritis to produce interleukin 1 in vitro.

    Directory of Open Access Journals (Sweden)

    Yamamura,Masahiro

    1990-12-01

    Full Text Available Twenty-four patients with rheumatoid arthritis (RA and 20 normal controls were examined for the ability of their peripheral blood B cells to produce interleukin 1 (IL-1 with or without lipopolysaccharide (LPS. B cells were purified from peripheral blood by negative selection methods (i.e., removal of adherent cells and sheep red blood cell rosette-forming cells, followed by treatment with monoclonal antibodies (OKT3 and OKM1 and complement. The amount of IL-1 in B cell culture supernatants (SN was measured by thymocyte and fibroblast proliferation assays and an enzyme-linked immunosorbent assay for IL-1 alpha and beta. As a group, cultured B cells from patients with RA, both spontaneously and when stimulated with LPS, produced higher levels of IL-1 than those from normal controls. IL-1 production by RA B cells with LPS had a weak but positive correlation with disease activity. Moreover, RA B cell culture SN with elevated levels of IL-1 had a synergistic effect on the growth of anti-human IgM (anti-mu stimulated B cells. In separate experiments, the growth of RA B cells was significantly promoted by IL-1 beta both with and without anti-mu stimulation. These results suggest that B cell-derived IL-1 may be involved in the B cell clonal expansion of RA through its own activity as a B cell stimulatory factor.

  17. B cells promote tumor progression via STAT3 regulated-angiogenesis.

    Directory of Open Access Journals (Sweden)

    Chunmei Yang

    Full Text Available The role of B cells in cancer and the underlying mechanisms remain to be further explored. Here, we show that tumor-associated B cells with activated STAT3 contribute to tumor development by promoting tumor angiogenesis. B cells with or without Stat3 have opposite effects on tumor growth and tumor angiogenesis in both B16 melanoma and Lewis Lung Cancer mouse models. Ex vivo angiogenesis assays show that B cell-mediated tumor angiogenesis is mainly dependent on the induction of pro-angiogenic gene expression, which requires Stat3 signaling in B cells. Furthermore, B cells with activated STAT3 are mainly found in or near tumor vasculature and correlate significantly with overall STAT3 activity in human tumors. Moreover, the density of B cells in human tumor tissues correlates significantly with expression levels of several STAT3-downstream pro-angiogenic genes, as well as the degree of tumor angiogenesis. Together, these findings define a novel role of B cells in promoting tumor progression through angiogenesis and identify STAT3 in B cells as potential therapeutic target for anti-angiogenesis therapy.

  18. An in vitro study of liposomal curcumin: stability, toxicity and biological activity in human lymphocytes and Epstein-Barr virus-transformed human B-cells.

    Science.gov (United States)

    Chen, Changguo; Johnston, Thomas D; Jeon, Hoonbae; Gedaly, Roberto; McHugh, Patrick P; Burke, Thomas G; Ranjan, Dinesh

    2009-01-21

    Curcumin is a multi-functional and pharmacologically safe natural agent. Used as a food additive for centuries, it also has anti-inflammatory, anti-virus and anti-tumor properties. We previously found that it is a potent inhibitor of cyclosporin A (CsA)-resistant T-cell co-stimulation pathway. It inhibits mitogen-stimulated lymphocyte proliferation, NFkappaB activation and IL-2 signaling. In spite of its safety and efficacy, the in vivo bioavailability of curcumin is poor, and this may be a major obstacle to its utility as a therapeutic agent. Liposomes are known to be excellent carriers for drug delivery. In this in vitro study, we report the effects of different liposome formulations on curcumin stability in phosphate buffered saline (PBS), human blood, plasma and culture medium RPMI-1640+10% FBS (pH 7.4, 37 degrees C). Liposomal curcumin had higher stability than free curcumin in PBS. Liposomal and free curcumin had similar stability in human blood, plasma and RPMI-1640+10% FBS. We looked at the toxicity of non-drug-containing liposomes on (3)H-thymidine incorporation by concanavalin A (Con A)-stimulated human lymphocytes, splenocytes and Epstein-Barr virus (EBV)-transformed human B-cell lymphoblastoid cell line (LCL). We found that dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylglycerol (DMPG) were toxic to the tested cells. However, addition of cholesterol to the lipids at DMPC:DMPG:cholesterol=7:1:8 (molar ratio) almost completely eliminated the lipid toxicity to these cells. Liposomal curcumin had similar or even stronger inhibitory effects on Con A-stimulated human lymphocyte, splenocyte and LCL proliferation. We conclude that liposomal curcumin may be useful for intravenous administration to improve the bioavailability and efficacy, facilitating in vivo studies that could ultimately lead to clinical application of curcumin.

  19. Regulation of N- and L-type Ca2+ channels in adult frog sympathetic ganglion B cells by nerve growth factor in vitro and in vivo.

    Science.gov (United States)

    Lei, S; Dryden, W F; Smith, P A

    1997-12-01

    To examine mechanisms responsible for the long-term regulation of Ca2+-channels in an adult neuron, changes in whole cell Ba2+ current (IBa) were examined in adult bullfrog sympathetic ganglion B cells in vitro. Cells were cultured at low density in defined, serum free medium. After 15 days, total IBa was similar to the initial value, whereas IBa density was reduced by approximately 36%, presumably due to an increase in neuronal surface area. By contrast, IBa density remained constant after 6-15 days in the presence of murine beta-NGF (200 ng/ml), and total IBa was almost doubled. Inclusion of cytosine arabinoside (Ara-C; 10 microM) to inhibit proliferation of nonneuronal cells, did not affect the survival of neurons in the absence of nerve growth factor (NGF) nor did it attenuate IBa. Ara-C did not prevent the effect of NGF on IBa. There were three independent components to the action of NGF; during 6-9 days, it increased omega-conotoxin-GVIA-sensitive N-type IBa (IBa,N); increased nifedipine-sensitive L-type IBa (IBa,L) and decreased inactivation of the total Ba2+ conductance (gBa). The latter effect involved a selective decrease in the amplitude of one of the four kinetic components that describe the inactivation process. Total IBa was also 55.8% larger than control in the somata of B cells acutely dissociated from leopard frogs that had received prior subcutaneous injections of NGF. By contrast, injection of NGF antiserum decreased total IBa by 29.4%. There was less inactivation of gBa in B cells from NGF-injected animals than in cells from animals injected with NGF antiserum (P < 0.001). These data suggest that NGF-like molecule(s) play(s) a role in the maintenance of IBa in an adult amphibian sympathetic neuron; the presence of NGF may allow the neuron to maintain a constant relationship between cell size and current density. They also show that IBa inactivation in an adult neuron can be modulated in a physiologically relevant way by an extracellular ligand.

  20. AID activity in B cells strongly correlates with polyclonal antibody affinity maturation in-vivo following pandemic 2009-H1N1 vaccination in humans.

    Science.gov (United States)

    Khurana, Surender; Frasca, Daniela; Blomberg, Bonnie; Golding, Hana

    2012-09-01

    The role of Activation-Induced Cytidine Deaminase (AID) in somatic hypermutation and polyclonal antibody affinity maturation has not been shown for polyclonal responses in humans. We investigated whether AID induction in human B cells following H1N1pdm09 vaccination correlated with in-vivo antibody affinity maturation against hemagglutinin domains in plasma of young and elderly individuals. AID was measured by qPCR in B cells from individuals of different ages immunized with the H1N1pdm09 influenza vaccine. Polyclonal antibody affinity in human plasma for the HA1 and HA2 domains of the H1N1pdm09 hemagglutinin was measured by antibody-antigen complex dissociation rates using real time kinetics in Surface Plasmon Resonance. Results show an age-related decrease in AID induction in B cells following H1N1pdm09 vaccination. Levels of AID mRNA before vaccination and fold-increase of AID mRNA expression after H1N1pdm09 vaccination directly correlated with increase in polyclonal antibody affinity to the HA1 globular domain (but not to the conserved HA2 stalk). In the younger population, significant affinity maturation to the HA1 globular domain was observed, which associated with initial levels of AID and fold-increase in AID after vaccination. In some older individuals (>65 yr), higher affinity to the HA1 domain was observed before vaccination and H1N1pdm09 vaccination resulted in minimal change in antibody affinity, which correlated with low AID induction in this age group. These findings demonstrate for the first time a strong correlation between AID induction and in-vivo antibody affinity maturation in humans. The ability to generate high affinity antibodies could have significant impact on the elucidation of age-specific antibody responses following vaccination and eventual clinical efficacy and disease outcome.

  1. A proliferation-inducing ligand sustains the proliferation of human naïve (CD27⁻) B cells and mediates their differentiation into long-lived plasma cells in vitro via transmembrane activator and calcium modulator and cyclophilin ligand interactor and B-cell mature antigen.

    Science.gov (United States)

    Matsuda, Yoshiko; Haneda, Masataka; Kadomatsu, Kenji; Kobayashi, Takaaki

    2015-06-01

    Long-lived plasma cells (PCs) contribute to humoral immunity through an undefined mechanism. Memory B cells, but not human naïve B cells, can be induced to differentiate into long-lived PCs in vitro. Because evidence links a proliferation-inducing ligand (APRIL), a tumor necrosis factor family member, to the ability of bone marrow to mediate long-term PC survival, we reasoned that APRIL influences the proliferation and differentiation of naïve B cells. We describe here the development of a simple cell culture system that allowed us to show that APRIL sustained the proliferation of naïve human B cells and induced them to differentiate into long-lived PCs. Blocking the transmembrane activator and calcium modulator and cyclophilin ligand interactor or B-cell mature antigen shows they were required for the differentiation of naïve B cells into long-lived PCs in vitro. Our in vitro culture system will reveal new insights into the biology of long-lived PCs.

  2. Elevation of c-MYC Disrupts HLA Class II-mediated Immune Recognition of Human B-cell Tumors1

    Science.gov (United States)

    God, Jason M.; Cameron, Christine; Figueroa, Janette; Amria, Shereen; Hossain, Azim; Kempkes, Bettina; Bornkamm, Georg W.; Stuart, Robert K.; Blum, Janice S.; Haque, Azizul

    2014-01-01

    Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B-cell lymphomas. While many of c-MYC’s functions have been elucidated, its effect on the presentation of antigen (Ag) through the HLA class II pathway has not previously been reported. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report here that increased c-MYC expression has a negative effect on the ability of B-cell lymphomas to functionally present Ags/peptides to CD4+ T cells. This defect was associated with alterations in the expression of distinct co-factors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt’s lymphoma (BL) tumors and transformed cells, we show that compared to B-lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation which contribute to the immunoevasive properties of BL tumors. PMID:25595783

  3. Elevation of c-MYC disrupts HLA class II-mediated immune recognition of human B cell tumors.

    Science.gov (United States)

    God, Jason M; Cameron, Christine; Figueroa, Janette; Amria, Shereen; Hossain, Azim; Kempkes, Bettina; Bornkamm, Georg W; Stuart, Robert K; Blum, Janice S; Haque, Azizul

    2015-02-15

    Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B cell lymphomas. Although many of c-MYC's functions have been elucidated, its effect on the presentation of Ag through the HLA class II pathway has not been reported previously. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report in this paper that increased c-MYC expression has a negative effect on the ability of B cell lymphomas to functionally present Ags/peptides to CD4(+) T cells. This defect was associated with alterations in the expression of distinct cofactors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt's lymphoma (BL) tumors and transformed cells, we show that compared with B lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47-kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation, which contribute to the immunoevasive properties of BL tumors.

  4. Malignancies, Particularly B-Cell Lymphomas, Are a Frequent Cause of Mortality in Human Immunodeficiency Virus-1 Patients Despite Highly Active Antiretroviral Therapy

    Science.gov (United States)

    Griffin, Daniel O.; Metzger, Michael; Poeth, Kaitlin; Deng, Kathy; Dharsee, Arif; Rico, Juan Carlos; McGowan, Joseph

    2015-01-01

    Human immunodeficiency virus (HIV)-1-infected individuals are affected by diseases at rates above those of their HIV-negative peers despite the increased life expectancy of the highly active antiretroviral therapy era. We followed a cohort of approximately 2000 HIV-1-infected patients for 5 years. The most frequent cause of death in this HIV-1-infected cohort was malignancy, with 39% of all classified deaths due to cancer. Among the cancer deaths, B-cell lymphomas were the most commonly seen malignancy, representing 34% of all cancer deaths. These lymphomas were very aggressive with a median survival of <2 months from time of diagnosis. PMID:26566539

  5. Diphtheria Toxin/Human B-Cell Activating Factor Fusion Protein Kills Human Acute Lymphoblastic Leukemia BALL-1 Cells: An Experimental Study

    Institute of Scientific and Technical Information of China (English)

    Xin-pu Gao; Zheng-min Liu; Yu-lian Jiao; Bin Cui; Yue-ting Zhu; Jie Zhang; Lai-cheng Wang; Yue-ran Zhao

    2012-01-01

    Objective:This study aimed to express a fusion protein of diphtheria toxin and human B ceil-activating factor (DT388sBAFF) in Escherichia coli (E.coli) and investigate its activity in human B-lineage acute lymphoblastic leukemia 1 cells (BALL-1).Methods:A fragment of DT388sBAFF fusion gene was separated from plasmid pUC57-DT388sBAFF digested with Nde Ⅰ and Xho Ⅰ,and inserted into the expression vector pcold Ⅱ digested with the same enzymes.Recombinants were screened by the colony polymerase chain reaction (PCR) and restriction map.The recombinant expression vector was transformed into BL21 and its expression was induced by isopropyl β-D-1-thiogalactopyranoside (IPTG).The recombinant protein was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot,and then purified by Ni2+-NTA affinity chromatography.The expression level of B cell-activating factor receptor (BAFF-R) on BALL-1 cells was assessed by real-time PCR.The receptor binding capacity of recombinant protein was determined by cell fluorescent assay.The specific cytotoxicity of recombinant protein on BALL-1 cells was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay.Results:The expression level of recombinant protein was 50% of total bacterial proteins in E.coli,and the recombinant protein could bind to BAFF-R-positive BALL-1 cells and thereby produce a cytotoxic effect on the cells.Conclusion:The fusion protein expression vector DT388sBAFF was successfully constructed and the recombinant protein with selective cytotoxicity against BALL-1 cells was obtained,providing foundation for further study of the therapy of human B-lineage acute lymphoblastic leukemia.

  6. Linear B-cell epitope mapping of MAPK3 and MAPK4 from Leishmania braziliensis: implications for the serodiagnosis of human and canine leishmaniasis.

    Science.gov (United States)

    Menezes-Souza, Daniel; de Oliveira Mendes, Tiago Antônio; de Araújo Leão, Ana Carolina; de Souza Gomes, Matheus; Fujiwara, Ricardo Toshio; Bartholomeu, Daniella Castanheira

    2015-02-01

    The correct and early identification of humans and dogs infected with Leishmania are key steps in the control of leishmaniasis. Additionally, a method with high sensitivity and specificity at low cost that allows the screening of a large number of samples would be extremely valuable. In this study, we analyzed the potential of mitogen-activated protein kinase 3 (MAPK3) and mitogen-activated protein kinase 4 (MAPK4) proteins from Leishmania braziliensis to serve as antigen candidates for the serodiagnosis of human visceral and tegumentary leishmaniasis, as well as canine visceral disease. Moreover, we mapped linear B-cell epitopes in these proteins and selected those epitopes with sequences that were divergent in the corresponding orthologs in Homo sapiens, in Canis familiaris, and in Trypanosoma cruzi. We compared the performance of these peptides with the recombinant protein using ELISA. Both MAPK3 and MAPK4 recombinant proteins showed better specificity in the immunodiagnosis of human and canine leishmaniasis than soluble parasite antigens and the EIE-leishmaniose-visceral-canina-bio-manguinhos (EIE-LVC) kit. Furthermore, the performance of this serodiagnosis assay was improved using synthetic peptides corresponding to B-cell epitopes derived from both proteins.

  7. Effects of prostaglandin E2 on p53 mRNA transcription and p53 mutagenesis during T-cell-independent human B-cell clonal expansion

    Science.gov (United States)

    Haque, Shabirul; Yan, Xiao Jie; Rosen, Lisa; McCormick, Steven; Chiorazzi, Nicholas; Mongini, Patricia K. A.

    2014-01-01

    Within T-cell-dependent germinal centers, p53 gene transcription is repressed by Bcl-6 and is thus less vulnerable to mutation. Malignant lymphomas within inflamed extranodal sites exhibit a relatively high incidence of p53 mutations. The latter might originate from normal B-cell clones manifesting activation-induced cytosine deaminase (AID) and up-regulated p53 following T-cell-independent (TI) stimulation. We here examine p53 gene transcription in such TI clones, with a focus on modulatory effects of prostaglandin E2 (PGE2), and evaluate progeny for p53 mutations. Resting IgM+IgD+CD27− B cells from human tonsils were labeled with CFSE and stimulated in vitro with complement-coated antigen surrogate, IL-4, and BAFF ± exogenous PGE2 (50 nM) or an analog specific for the EP2 PGE2 receptor. We use flow cytometry to measure p53 and AID protein within variably divided blasts, qRT-PCR of p53 mRNA from cultures with or without actinomycin D to monitor mRNA transcription/stability, and single-cell p53 RT-PCR/sequencing to assess progeny for p53 mutations. We report that EP2 signaling triggers increased p53 gene transcriptional activity in AID+ cycling blasts (P<0.01). Progeny exhibit p53 mutations at a frequency (8.5×10−4) greater than the baseline error rate (<0.8×10−4). We conclude that, devoid of the repressive influences of Bcl-6, dividing B lymphoblasts in inflamed tissues should display heightened p53 transcription and increased risk of p53 mutagenesis.—Haque, S., Yan, X. J., Rosen, L., McCormick, S., Chiorazzi, N., Mongini, P. K. A. Effects of prostaglandin E2 on p53 mRNA transcription and p53 mutagenesis during T-cell-independent human B-cell clonal expansion. PMID:24145719

  8. Human dendritic cells activated via dectin-1 are efficient at priming Th17, cytotoxic CD8 T and B cell responses.

    Directory of Open Access Journals (Sweden)

    Sudhanshu Agrawal

    Full Text Available BACKGROUND: Dendritic cells capture antigens through PRRs and modulate adaptive immune responses. The type of adaptive immune T cell response generated is dependent upon the type of PRR activated by the microbes. Dectin-1 is a C-type lectin receptor present on dendritic cells. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that selective dectin-1 agonist Curdlan can activate human DCs and induce the secretion of large amounts of IL-23, IL-1β, IL-6 and low levels of IL-12p70 as determined by ELISA. The Curdlan-stimulated DCs are efficient at priming naïve CD4 cells to differentiate into Th17 and Th1 cells. Furthermore, these CD4 T cells induce differentiation of B cells to secrete IgG and IgA. In addition, Curdlan-stimulated DCs promote the expansion and differentiation of Granzyme and perforin expressing cytotoxic T lymphocyte that display high cytolytic activity against target tumor cells in vitro. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that DCs stimulated through Dectin-1 can generate efficient Th, CTL and B cell responses and can therefore be used as effective mucosal and systemic adjuvants in humans.

  9. Human Capital, Fertility and Growth

    OpenAIRE

    Galor, Oded

    2006-01-01

    The demographic transition that swept the world in the past 140 years has been identified as one of the prime forces in the transition from stagnation to growth. The unprecedented increase in population growth during the early stages of industrialization was ultimately reversed. The rise in the demand for human capital in the second phase of industrialization brought about a significant reduction in fertility rates and population growth in various regions of the world, enabling economies to c...

  10. PATZ1 expression correlates positively with BAX and negatively with BCL6 and survival in human diffuse large B cell lymphomas

    Science.gov (United States)

    Valentino, Elena; Vitiello, Michela; Luciano, Antonio; Palma, Giuseppe; Arra, Claudio; Mantia, Elvira La; Panico, Luigi; Tenneriello, Valentina; Pinto, Antonello; Frigeri, Ferdinando; Capobianco, Gaetana; Botti, Gerardo; Cerchia, Laura; De Chiara, Annarosaria; Fedele, Monica

    2016-01-01

    Non-Hodgkin lymphomas (NHLs) include a heterogeneous group of diseases, which differ in both cellular origin and clinical behavior. Among the aggressive malignancies of this group, the diffuse large B-cell lymphomas (DLBCLs) are the most frequently observed. They are themselves clinically and molecularly heterogeneous and have been further sub-divided in three sub-types according to different cell of origin, mechanisms of oncogenesis and clinical outcome. Among them, the germinal center B-cell-like (GCB) derives from the germinal center and expresses the BCL6 oncogene. We have previously shown that Patz1-knockout mice develop B-cell neoplasias, suggesting a tumor suppressor role for PATZ1 in human NHLs. Here, by immunohistochemical analysis of a tissue-microarray including 170 NHLs, we found that PATZ1 nuclear expression is down-regulated in follicular lymphomas and DLBCLs. Moreover, consistent with our previous results showing a PATZ1-dependent regulation of BCL6 and BAX transcription, we show that low PATZ1 nuclear expression significantly correlates with high BCL6 expression, mainly in DLBCLs, and with low BAX expression, also considering separately follicular lymphomas and DLBCLs. Finally, by analyzing overall and progression-free survival in DLBCL patients that underwent rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy, low levels of PATZ1 were significantly associated to a worst outcome and demonstrated an independent prognostic factor in multivariate analysis, including known prognostic factors of DLBCL, IPI score and cell of origin (GCB/non-GCB). Therefore, we propose PATZ1 as a new prognostic marker of DLBCLs, which may act as a tumor suppressor by enhancing apoptosis through inhibiting and enhancing transcription of BCL6 and BAX, respectively. PMID:27494852

  11. Platelet-activating factor induces phospholipid turnover, calcium flux, arachidonic acid liberation, eicosanoid generation, and oncogene expression in a human B cell line

    Energy Technology Data Exchange (ETDEWEB)

    Schulam, P.G.; Kuruvilla, A.; Putcha, G.; Mangus, L.; Franklin-Johnson, J.; Shearer, W.T. (Baylor College of Medicine, Houston, TX (USA))

    1991-03-01

    Platelet-activating factor is a potent mediator of the inflammatory response. Studies of the actions of platelet-activating factor have centered mainly around neutrophils, monocytes, and platelets. In this report we begin to uncover the influence of platelet-activating factor on B lymphocytes. Employing the EBV-transformed human B cell line SKW6.4, we demonstrate that platelet-activating factor significantly alters membrane phospholipid metabolism indicated by the incorporation of 32P into phosphatidylcholine, phosphatidylinositol, and phosphatidic acid but not significantly into phosphatidylethanolamine at concentrations ranging from 10(-9) to 10(-6) M. The inactive precursor, lyso-platelet-activating factor, at a concentration as high as 10(-7) M had no effect on any of the membrane phospholipids. We also show that platelet-activating factor from 10(-12) to 10(-6) M induced rapid and significant elevation in intracellular calcium levels, whereas lyso-platelet-activating factor was again ineffective. We further demonstrate the impact of platelet-activating factor binding to B cells by measuring platelet-activating factor induced arachidonic acid release and 5-hydroxyeicosatetraenoic acid production. Moreover, platelet-activating factor was capable of inducing transcription of the nuclear proto-oncogenes c-fos and c-jun. Finally we explored the possible role of 5-hydroxyeicosatetraenoic acid as a regulator of arachidonic acid liberation demonstrating that endogenous 5-lipoxygenase activity modulates platelet-activating factor induced arachidonic acid release perhaps acting at the level of phospholipase A2. In summary, platelet-activating factor is shown here to have a direct and profound effect on a pure B cell line.

  12. Lymphoid-Like Structures with Distinct B Cell Areas in Kidney Allografts are not Predictive for Graft Rejection. A Non-human Primate Study

    NARCIS (Netherlands)

    Jonker, Margreet; Wubben, Jacqueline A. M.; 't Hart, Bert A.; Haanstra, Krista G.

    2015-01-01

    Kidney allograft biopsies were analyzed for the presence of B cell clusters/aggregates using CD20 staining. Few B cells were found in the diffuse interstitial infiltrates, but clusters of B cells were found in nodular infiltrates. These nodular infiltrates were smaller shortly after transplantation,

  13. TLR5 signaling enhances the proliferation of human allogeneic CD40-activated B cell induced CD4hiCD25+ regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Ping-Lung Chan

    Full Text Available Although diverse functions of different toll-like receptors (TLR on human natural regulatory T cells have been demonstrated recently, the role of TLR-related signals on human induced regulatory T cells remain elusive. Previously our group developed an ex vivo high-efficient system in generating human alloantigen-specific CD4(hiCD25(+ regulatory T cells from naïve CD4(+CD25(- T cells using allogeneic CD40-activated B cells as stimulators. In this study, we investigated the role of TLR5-related signals on the generation and function of these novel CD4(hiCD25(+ regulatory T cells. It was found that induced CD4(hiCD25(+ regulatory T cells expressed an up-regulated level of TLR5 compared to their precursors. The blockade of TLR5 using anti-TLR5 antibodies during the co-culture decreased CD4(hiCD25(+ regulatory T cells proliferation by induction of S phase arrest. The S phase arrest was associated with reduced ERK1/2 phosphorylation. However, TLR5 blockade did not decrease the CTLA-4, GITR and FOXP3 expressions, and the suppressive function of CD4(hiCD25(+ regulatory T cells. In conclusion, we discovered a novel function of TLR5-related signaling in enhancing the proliferation of CD4(hiCD25(+ regulatory T cells by promoting S phase progress but not involved in the suppressive function of human CD40-activated B cell-induced CD4(hiCD25(+ regulatory T cells, suggesting a novel role of TLR5-related signals in the generation of induced regulatory T cells.

  14. CD47 agonist peptides induce programmed cell death in refractory chronic lymphocytic leukemia B cells via PLCγ1 activation: evidence from mice and humans.

    Directory of Open Access Journals (Sweden)

    Ana-Carolina Martinez-Torres

    2015-03-01

    , which might be improved to reach the standard requirements in drug development, and the lack of a CLL animal model that fully mimics the human disease.Our work provides substantial progress in (i the development of serum-stable CD47 agonist peptides that are highly effective at inducing PCD in CLL, (ii the understanding of the molecular events regulating a novel PCD pathway that overcomes CLL apoptotic avoidance, (iii the identification of PLCγ1 as an over-expressed protein in CLL B cells, and (iv the description of a novel peptide-based strategy against CLL.

  15. Comparative Analysis of Toxic Responses of Organic Extracts from Diesel and Selected Alternative Fuels Engine Emissions in Human Lung BEAS-2B Cells

    Directory of Open Access Journals (Sweden)

    Helena Libalova

    2016-11-01

    Full Text Available This study used toxicogenomics to identify the complex biological response of human lung BEAS-2B cells treated with organic components of particulate matter in the exhaust of a diesel engine. First, we characterized particles from standard diesel (B0, biodiesel (methylesters of rapeseed oil in its neat form (B100 and 30% by volume blend with diesel fuel (B30, and neat hydrotreated vegetable oil (NEXBTL100. The concentration of polycyclic aromatic hydrocarbons (PAHs and their derivatives in organic extracts was the lowest for NEXBTL100 and higher for biodiesel. We further analyzed global gene expression changes in BEAS-2B cells following 4 h and 24 h treatment with extracts. The concentrations of 50 µg extract/mL induced a similar molecular response. The common processes induced after 4 h treatment included antioxidant defense, metabolism of xenobiotics and lipids, suppression of pro-apoptotic stimuli, or induction of plasminogen activating cascade; 24 h treatment affected fewer processes, particularly those involved in detoxification of xenobiotics, including PAHs. The majority of distinctively deregulated genes detected after both 4 h and 24 h treatment were induced by NEXBTL100; the deregulated genes included, e.g., those involved in antioxidant defense and cell cycle regulation and proliferation. B100 extract, with the highest PAH concentrations, additionally affected several cell cycle regulatory genes and p38 signaling.

  16. Affinity Capillary Electrophoresis:Study of the Binding of HIV-1 gp41 with a Membrane Protein (P45) on the Human B Cell Line,Raji

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Affinity capillary electrophoresis has been used to study the interaction between a membrane protein (P45) isolated from the Human B cell line, Raji, and rsgp41. P45, rsgp41 and the complexes were well resolved. The entire separation was achieved in less than 3min. Formations of two kinds of stable P45-rsgp41 complexes were confirmed based on migration time comparison; the binding equilibrium was achieved as soon as two proteins were mixed. The results indicate that the interaction between P45 and rsgp41 is strong with a fast association rate and a slow dissociation rate, and there are at least two kinds of binding sites with different binding constants between P45 and rsgp41.

  17. Immunization of rabbits with highly purified, soluble, trimeric human immunodeficiency virus type 1 envelope glycoprotein induces a vigorous B cell response and broadly cross-reactive neutralization.

    Directory of Open Access Journals (Sweden)

    Gerald V Quinnan

    Full Text Available Previously we described induction of cross-reactive HIV-1 neutralizing antibody responses in rabbits using a soluble HIV-1 gp140 envelope glycoprotein (Env in an adjuvant containing monophosphoryl lipid A (MPL and QS21 (AS02A. Here, we compared different forms of the same HIV-1 strain R2 Env for antigenic and biophysical characteristics, and in rabbits characterized the extent of B cell induction for specific antibody expression and secretion and neutralizing responses. The forms of this Env that were produced in and purified from stably transformed 293T cells included a primarily dimeric gp140, a trimeric gp140 appended to a GCN4 trimerization domain (gp140-GCN4, gp140-GCN4 with a 15 amino acid flexible linker between the gp120 and gp41 ectodomain (gp140-GCN4-L, also trimeric, and a gp140 with the flexible linker purified from cell culture supernatants as either dimer (gp140-L(D or monomer (gp140-L(M. Multimeric states of the Env proteins were assessed by native gel electrophoresis and analytical ultracentrifugation. The different forms of gp140 bound broadly cross-reactive neutralizing (BCN human monoclonal antibodies (mAbs similarly in ELISA and immunoprecipitation assays. All Envs bound CD4i mAbs in the presence and absence of sCD4, as reported for the R2 Env. Weak neutralization of some strains of HIV-1 was seen after two additional doses in AS02A. Rabbits that were given a seventh dose of gp140-GCN4-L developed BCN responses that were weak to moderate, similar to our previous report. The specificity of these responses did not appear similar to that of any of the known BCN human mAbs. Induction of spleen B cell and plasma cells producing immunoglobulins that bound trimeric gp140-GCN4-L was vigorous, based on ELISpot and flow cytometry analyses. The results demonstrate that highly purified gp140-GCN4-L trimer in adjuvant elicits BCN responses in rabbits accompanied by vigorous B cell induction.

  18. Schistosomes induce regulatory features in human and mouse CD1d(hi B cells: inhibition of allergic inflammation by IL-10 and regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Luciën E P M van der Vlugt

    Full Text Available Chronic helminth infections, such as schistosomes, are negatively associated with allergic disorders. Here, using B cell IL-10-deficient mice, Schistosoma mansoni-mediated protection against experimental ovalbumin-induced allergic airway inflammation (AAI was shown to be specifically dependent on IL-10-producing B cells. To study the organs involved, we transferred B cells from lungs, mesenteric lymph nodes or spleen of OVA-infected mice to recipient OVA-sensitized mice, and showed that both lung and splenic B cells reduced AAI, but only splenic B cells in an IL-10-dependent manner. Although splenic B cell protection was accompanied by elevated levels of pulmonary FoxP3(+ regulatory T cells, in vivo ablation of FoxP3(+ T cells only moderately restored AAI, indicating an important role for the direct suppressory effect of regulatory B cells. Splenic marginal zone CD1d(+ B cells proved to be the responsible splenic B cell subset as they produced high levels of IL-10 and induced FoxP3(+ T cells in vitro. Indeed, transfer of CD1d(+ MZ-depleted splenic B cells from infected mice restored AAI. Markedly, we found a similarly elevated population of CD1d(hi B cells in peripheral blood of Schistosoma haematobium-infected Gabonese children compared to uninfected children and these cells produced elevated levels of IL-10. Importantly, the number of IL-10-producing CD1d(hi B cells was reduced after anti-schistosome treatment. This study points out that in both mice and men schistosomes have the capacity to drive the development of IL-10-producing regulatory CD1d(hi B cells and furthermore, these are instrumental in reducing experimental allergic inflammation in mice.

  19. MYSM1-dependent checkpoints in B cell lineage differentiation and B cell-mediated immune response.

    Science.gov (United States)

    Förster, Michael; Farrington, Kyo; Petrov, Jessica C; Belle, Jad I; Mindt, Barbara C; Witalis, Mariko; Duerr, Claudia U; Fritz, Jörg H; Nijnik, Anastasia

    2017-03-01

    MYSM1 is a chromatin-binding histone deubiquitinase. MYSM1 mutations in humans result in lymphopenia whereas loss of Mysm1 in mice causes severe hematopoietic abnormalities, including an early arrest in B cell development. However, it remains unknown whether MYSM1 is required at later checkpoints in B cell development or for B cell-mediated immune responses. We analyzed conditional mouse models Mysm1(fl/fl)Tg.mb1-cre, Mysm1(fl/fl)Tg.CD19-cre, and Mysm1(fl/fl)Tg.CD21-cre with inactivation of Mysm1 at prepro-B, pre-B, and follicular B cell stages of development. We show that loss of Mysm1 at the prepro-B cell stage in Mysm1(fl/fl)Tg.mb1-cre mice results in impaired B cell differentiation, with an ∼2-fold reduction in B cell numbers in the lymphoid organs. Mysm1(fl/fl)Tg.mb1-cre B cells also showed increased expression of activation markers and impaired survival and proliferation. In contrast, Mysm1 was largely dispensable from the pre-B cell stage onward, with Mysm1(fl/fl)Tg.CD19-cre and Mysm1(fl/fl)Tg.CD21-cre mice showing no alterations in B cell numbers and largely normal responses to stimulation. MYSM1, therefore, has an essential role in B cell lineage specification but is dispensable at later stages of development. Importantly, MYSM1 activity at the prepro-B cell stage of development is important for the normal programming of B cell responses to stimulation once they complete their maturation process.

  20. An improved technique for obtaining E rosettes with human lymphocytes and its use for B cell purification

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Heron, I

    1977-01-01

    The standard E rosette method and two previously described methods claimed to give improved E rosetting for enumeration of human T lymphocytes have been compared with respect to the speed of rosette formation, and the mechanical stability of the rosettes formed. Following rosette formation with t...

  1. BCG Infection to Human B Cells Induce Cell Apoptosis%卡介苗感染人B细胞诱导细胞凋亡

    Institute of Scientific and Technical Information of China (English)

    朱旗; 冯国栋; 杨毅宁; 赵青; 王文菁; 张敏; 刘扬; 赵钢

    2015-01-01

    目的 探究卡介苗( BCG)是否能感染人B细胞及观察感染后对细胞的影响. 方法 人B细胞系Raji细胞与BCG共培养, 4、12和24h后分别用共聚焦及透射电镜观察Raji细胞对BCG的结合和摄取情况,用CCK-8法检测细胞毒性,流式An-nexin Ⅴ-PI双标法检测细胞凋亡和坏死情况. 结果 培养4、12和24h后,感染了BCG的细胞比例分别为12. 4%±2. 0%, 23. 8%±5. 1%, 25. 2%±4. 8%.BCG感染可引起细胞毒性,4h后Raji细胞存活率为75. 5%±8. 8%,12h后细胞存活率降至51. 0%± 5. 3%,24h后细胞存活率仅为21. 6%±4. 2%,而感染灭活BCG的细胞存活率均在95%以上. 进一步用流式检测凋亡坏死发现,与未感染细胞相比,Raji细胞感染BCG后凋亡,坏死均有所增加,以凋亡增加为主. 结论 BCG可以感染人B细胞并诱导细胞凋亡.%Objective To explore whether Bacillus Calmette-Guérin ( BCG) can infect human B cells and observe the effects of the infection on B cells. Methods Human B cell line Raji cells were incubated with BCG. After incubation for 4h, 12h and 24h, the direct interaction of Raji cells with BCG was observed under confocal microscopy and transmission electronic microscopy. Cytotoxity was detected by cell counting kit (CCK-8). Cell apoptosis and necrosis were assayed by flow cytometry. Results After 4h, 12h and 24h of incuba-tion, the percentage of Raji cells that were infected by BCG was 12. 4%±2. 0%, 23. 8%±5. 1%, 25. 2%±4. 8%, respectively. Live BCG infection induced cytotoxicity. The cell survival rates at 4h, 12h, 24h were 75. 5%±8. 8%, 51. 0%±5. 3%, 21. 6%±4. 2% re-spectively, while the cells infected with inactivated BCG showed a high survival rate of 95% at any time. Further analysis by flow cytome-try showed that cell apoptosis and necrosis, predominantly cell apoptosis of Raji cells were increased by BCG infection. Conclusion BCG can infect human B cells and induce cell apoptosis.

  2. Properties and functions of naive and memory B cells in human peripheral blood%人外周血初始B细胞和记忆性B细胞亚群的特征和功能

    Institute of Scientific and Technical Information of China (English)

    冯敛; 吴长有

    2010-01-01

    B淋巴细胞是免疫系统的重要免疫成份,主要功能是介导体液免疫应答.在人外周血中,按照B淋巴细胞的发育阶段及功能的不同,可将B淋巴细胞分为初始成熟B细胞、记忆B细胞和浆细胞.记忆B细胞又可分为IgM记忆B细胞和类型转换的记忆B细胞.近年来的研究表明,B淋巴细胞的亚群远比人想象中的复杂,因此对人B细胞各亚群的起源、发育和功能进行更深入的研究,将有助于治疗自身免疫性疾病,在慢性感染性疾病的治疗过程中找到新的策略,并指导研发安全有效的疫苗.%B lymphocytes are of important immunological component in immune system which are capable of mediating effective humoral immune response. According to developmental stages and functional differences, there are mainly three subsets of B cells in human peripheral blood including naive mature B cells, memory B cells and plasma cells. Memory B cells can be further divided into IgM memory B cells and switched memory B cells. However, recent studies indicate that B-cell subsets are more complicated than previously thought. Therefore, further understanding should be focused on the origin,development and specific function of B-cell subsets in human, which will be a great benefit to the development of therapeutic strategies to autoimmune and inflammatory diseases as well as to the design of effective and safe vaccines.

  3. B Cell Tolerance in Health and Disease

    Directory of Open Access Journals (Sweden)

    Murali Gururajan

    2014-02-01

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

  4. Growth charts of human development

    NARCIS (Netherlands)

    Van Buuren, Stef

    2014-01-01

    This article reviews and compares two types of growth charts for tracking human development over age. Both charts assume the existence of a continuous latent variable, but relate to the observed data in different ways. The D-score diagram summarizes developmental indicators into a single aggregate s

  5. p53 deficiency linked to B cell translocation gene 2 (BTG2) loss enhances metastatic potential by promoting tumor growth in primary and metastatic sites in patient-derived xenograft (PDX) models of triple-negative breast cancer.

    Science.gov (United States)

    Powell, Emily; Shao, Jiansu; Yuan, Yuan; Chen, Hsiang-Chun; Cai, Shirong; Echeverria, Gloria V; Mistry, Nipun; Decker, Keith F; Schlosberg, Christopher; Do, Kim-Anh; Edwards, John R; Liang, Han; Piwnica-Worms, David; Piwnica-Worms, Helen

    2016-01-27

    Despite advances in early diagnosis and treatment of cancer patients, metastasis remains the major cause of mortality. TP53 is one of the most frequently mutated genes in human cancer, and these alterations can occur during the early stages of oncogenesis or as later events as tumors progress to more aggressive forms. Previous studies have suggested that p53 plays a role in cellular pathways that govern metastasis. To investigate how p53 deficiency contributes to late-stage tumor growth and metastasis, we developed paired isogenic patient-derived xenograft (PDX) models of triple-negative breast cancer (TNBC) differing only in p53 status for longitudinal analysis. Patient-derived isogenic human tumor lines differing only in p53 status were implanted into mouse mammary glands. Tumor growth and metastasis were monitored with bioluminescence imaging, and circulating tumor cells (CTCs) were quantified by flow cytometry. RNA-Seq was performed on p53-deficient and p53 wild-type tumors, and functional validation of a lead candidate gene was performed in vivo. Isogenic p53 wild-type and p53-deficient tumors metastasized out of mammary glands and colonized distant sites with similar frequency. However, p53-deficient tumors metastasized earlier than p53 wild-type tumors and grew faster in both primary and metastatic sites as a result of increased proliferation and decreased apoptosis. In addition, greater numbers of CTCs were detected in the blood of mice engrafted with p53-deficient tumors. However, when normalized to tumor mass, the number of CTCs isolated from mice bearing parental and p53-deficient tumors was not significantly different. Gene expression profiling followed by functional validation identified B cell translocation gene 2 (BTG2), a downstream effector of p53, as a negative regulator of tumor growth both at primary and metastatic sites. BTG2 expression status correlated with survival of TNBC patients. Using paired isogenic PDX-derived metastatic TNBC cells

  6. The involvement of hematopoietic pre-B cell leukemia transcription factor-interacting protein in regulating epithelial-mesenchymal transition of human spinal glioblastoma.

    Science.gov (United States)

    Wang, Deliang; Wang, Li; Zhou, Yi; Zhao, Xinjun; Xiong, Hui

    2016-05-01

    To date, hematopoietic pre-B cell leukemia transcription factor-interacting protein (HPIP), a co-repressor for the transcription factor PBX, has been involved into the initiation and onset in a wide variety of cancers. However, the molecular mechanisms underlying HPIP-induced epithelial-mesenchymal transition (EMT) in the spinal glioblastoma have been under investigation. In the present study, spinal glioblastoma tissues, U87, and U251 cell lines were used and subjected to in vitro assays, such as RT-PCR, and Western blot. Here, in vitro assays revealed that HPIP mRNA and protein were highly expressed in five cases of spinal glioblastoma tissues, compared with non-tumor tissues. Subsequently, in vitro experiments demonstrated HPIP promoted the U87 and U251 cell growth and regulated the G1/S phase transitions in U87 and U251 cell cycle, respectively, accompanied by the increased expression of cyclin A2, cyclin B1, and cyclin D1. Furthermore, HPIP increased the expression of N-cadherin, Slug, and MMP2, and decreased the expression of E-cadherin. By contrast, knockdown of HPIP reversed HPIP-induced EMT biomarkers, migration, and invasion in U87 and U251 cells. In conclusion, our findings identified HPIP plays an important role in the progression and EMT of spinal glioblastoma, by which cell growth is improved. Thus, HPIP gene or protein could act as a useful target in the clinical practice.

  7. Hantaan virus infection induces both Th1 and ThGranzyme B+ cell immune responses that associated with viral control and clinical outcome in humans.

    Directory of Open Access Journals (Sweden)

    Ying Ma

    2015-04-01

    Full Text Available Hantaviruses infection causing severe emerging diseases with high mortality rates in humans has become public health concern globally. The potential roles of CD4(+T cells in viral control have been extensively studied. However, the contribution of CD4(+T cells to the host response against Hantaan virus (HTNV infection remains unclear. Here, based on the T-cell epitopes mapped on HTNV glycoprotein, we studied the effects and characteristics of CD4(+T-cell responses in determining the outcome of hemorrhagic fever with renal syndrome. A total of 79 novel 15-mer T-cell epitopes on the HTNV glycoprotein were identified, among which 20 peptides were dominant target epitopes. Importantly, we showed the presence of both effective Th1 responses with polyfunctional cytokine secretion and ThGranzyme B(+ cell responses with cytotoxic mediators production against HTNV infection. The HTNV glycoprotein-specific CD4(+T-cell responses inversely correlated with the plasma HTNV RNA load in patients. Individuals with milder disease outcomes showed broader epitopes targeted and stronger CD4(+T-cell responses against HTNV glycoproteins compared with more severe patients. The CD4(+T cells characterized by broader antigenic repertoire, stronger polyfunctional responses, better expansion capacity and highly differentiated effector memory phenotype(CD27-CD28-CCR7-CD45RA-CD127(hi would elicit greater defense against HTNV infection and lead to much milder outcome of the disease. The host defense mediated by CD4(+T cells may through the inducing antiviral condition of the host cells and cytotoxic effect of ThGranzyme B+ cells. Thus, these findings highlight the efforts of CD4(+T-cell immunity to HTNV control and provide crucial information to better understand the immune defense against HTNV infection.

  8. Human B-cell memory is shaped by age- and tissue-specific T-independent and GC-dependent events.

    Science.gov (United States)

    Aranburu, Alaitz; Piano Mortari, Eva; Baban, Anwar; Giorda, Ezio; Cascioli, Simona; Marcellini, Valentina; Scarsella, Marco; Ceccarelli, Sara; Corbelli, Sandro; Cantarutti, Nicoletta; De Vito, Rita; Inserra, Alessandro; Nicolosi, Luciana; Lanfranchi, Arnalda; Porta, Fulvio; Cancrini, Caterina; Finocchi, Andrea; Carsetti, Rita

    2017-02-01

    Switched and IgM memory B cells execute different and noninterchangeable functions. We studied memory B cells in children of different ages, in peripheral blood and spleen and compared them with those of children born asplenic or unable to build germinal centers. We show that, whereas switched memory B cells are mostly generated in the germinal centers at all ages, IgM memory B cells can be distinct in three types with different developmental history. Innate IgM memory B cells, the largest pool in infants, are generated in the spleen by a germinal center-independent mechanism. With age, if the spleen is present and germinal centers are functional, innate IgM memory B cells are remodelled and accumulate somatic mutations. The third type of IgM memory B cell is a by-product of the germinal center reaction. Our data suggest that the B-cell memory developmental program is implemented during the first 5-6 years of life.

  9. B Cell Epitope-Based Vaccination Therapy

    Directory of Open Access Journals (Sweden)

    Yoshie Kametani

    2015-08-01

    Full Text Available Currently, many peptide vaccines are undergoing clinical studies. Most of these vaccines were developed to activate cytotoxic T cells; however, the response is not robust. Unlike vaccines, anti-cancer antibodies based on passive immunity have been approved as a standard treatment. Since passive immunity is more effective in tumor treatment, the evidence suggests that limited B cell epitope-based peptide vaccines may have similar activity. Nevertheless, such peptide vaccines have not been intensively developed primarily because humoral immunity is thought to be preferable to cancer progression. B cells secrete cytokines, which suppress immune functions. This review discusses the possibility of therapeutic antibody induction by a peptide vaccine and the role of active and passive B cell immunity in cancer patients. We also discuss the use of humanized mice as a pre-clinical model. The necessity of a better understanding of the activity of B cells in cancer is also discussed.

  10. Loss of signalling via Gα13 in germinal centre B-cell-derived lymphoma.

    Science.gov (United States)

    Muppidi, Jagan R; Schmitz, Roland; Green, Jesse A; Xiao, Wenming; Larsen, Adrien B; Braun, Sterling E; An, Jinping; Xu, Ying; Rosenwald, Andreas; Ott, German; Gascoyne, Randy D; Rimsza, Lisa M; Campo, Elias; Jaffe, Elaine S; Delabie, Jan; Smeland, Erlend B; Braziel, Rita M; Tubbs, Raymond R; Cook, J R; Weisenburger, Dennis D; Chan, Wing C; Vaidehi, Nagarajan; Staudt, Louis M; Cyster, Jason G

    2014-12-11

    Germinal centre B-cell-like diffuse large B-cell lymphoma (GCB-DLBCL) is a common malignancy, yet the signalling pathways that are deregulated and the factors leading to its systemic dissemination are poorly defined. Work in mice showed that sphingosine-1-phosphate receptor-2 (S1PR2), a Gα12 and Gα13 coupled receptor, promotes growth regulation and local confinement of germinal centre B cells. Recent deep sequencing studies of GCB-DLBCL have revealed mutations in many genes in this cancer, including in GNA13 (encoding Gα13) and S1PR2 (refs 5,6, 7). Here we show, using in vitro and in vivo assays, that GCB-DLBCL-associated mutations occurring in S1PR2 frequently disrupt the receptor's Akt and migration inhibitory functions. Gα13-deficient mouse germinal centre B cells and human GCB-DLBCL cells were unable to suppress pAkt and migration in response to S1P, and Gα13-deficient mice developed germinal centre B-cell-derived lymphoma. Germinal centre B cells, unlike most lymphocytes, are tightly confined in lymphoid organs and do not recirculate. Remarkably, deficiency in Gα13, but not S1PR2, led to germinal centre B-cell dissemination into lymph and blood. GCB-DLBCL cell lines frequently carried mutations in the Gα13 effector ARHGEF1, and Arhgef1 deficiency also led to germinal centre B-cell dissemination. The incomplete phenocopy of Gα13- and S1PR2 deficiency led us to discover that P2RY8, an orphan receptor that is mutated in GCB-DLBCL and another germinal centre B-cell-derived malignancy, Burkitt's lymphoma, also represses germinal centre B-cell growth and promotes confinement via Gα13. These findings identify a Gα13-dependent pathway that exerts dual actions in suppressing growth and blocking dissemination of germinal centre B cells that is frequently disrupted in germinal centre B-cell-derived lymphoma.

  11. The analysis of VH and VL genes repertoires of Fab library built from peripheral B cells of human rabies virus vaccinated donors.

    Science.gov (United States)

    Houimel, Mehdi

    2014-08-01

    A human combinatorial Fab antibody library was generated from immune repertoire based on peripheral B cells of ten rabies virus vaccinated donors. The analysis of random Fab fragments from the unselected library presented some bias of V gene usage towards IGHV-genes and IGLV-gen families. The screening of the Fab library on rabies virus allowed specific human Fab antibody fragments characterized for their gene encoding sequences, binding and specificities to RV. Genetic analysis of selected Fabs indicated that the IGHV and IGLV differ from the germ-line sequence. At the level of nucleotide sequences, the IGHV and IGLV domains were found to share 74-92% and 90-96% homology with sequences encoded by the corresponding human germ-line genes respectively. IGHV domains are characterized most frequently by IGHV3 genes, and large proportions of the anti-RV heavy chain IGHV domains are obtained following a VDJ recombination process that uses IGHD3, IGHD2, IGHD1 and IGHD6 genes. IGHJ3 and IGHJ4 genes are predominantly used in RV-Fab. The IGLV domains are dominated by IGKV1, IGLV1 and IGLV3 genes. Numerous somatic hypermutations in the RV-specific IGHV are detected, but only limited amino acid replacement in most of the RV-specific IGLV particularly in those encoded by J proximal IGLV or IGKV genes are found. Furthermore, IGHV3-IGKV1, IGHV3-IGVL1, and IGHV3-IGLV3 germ-line family pairings are preferentially enriched after the screening on rabies virus.

  12. MLN0905, a small-molecule plk1 inhibitor, induces antitumor responses in human models of diffuse large B-cell lymphoma.

    Science.gov (United States)

    Shi, Judy Quiju; Lasky, Kerri; Shinde, Vaishali; Stringer, Bradley; Qian, Mark G; Liao, Debra; Liu, Ray; Driscoll, Denise; Nestor, Michelle Tighe; Amidon, Benjamin S; Rao, Youlan; Duffey, Matt O; Manfredi, Mark G; Vos, Tricia J; D' Amore, Natalie; Hyer, Marc L

    2012-09-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common of the non-Hodgkin lymphomas, accounting for up to 30% of all newly diagnosed lymphoma cases. Current treatment options for this disease are effective, but not always curative; therefore, experimental therapies continue to be investigated. We have discovered an experimental, potent, and selective small-molecule inhibitor of PLK1, MLN0905, which inhibits cell proliferation in a broad range of human tumor cells including DLBCL cell lines. In our report, we explored the pharmacokinetic, pharmacodynamic, and antitumor properties of MLN0905 in DLBCL xenograft models grown in mice. These studies indicate that MLN0905 modulates the pharmacodynamic biomarker phosphorylated histone H3 (pHisH3) in tumor tissue. The antitumor activity of MLN0905 was evaluated in three human subcutaneous DLBCL xenograft models, OCI LY-10, OCI LY-19, and PHTX-22L (primary lymphoma). In each model, MLN0905 yielded significant antitumor activity on both a continuous (daily) and intermittent dosing schedule, underscoring dosing flexibility. The antitumor activity of MLN0905 was also evaluated in a disseminated xenograft (OCI LY-19) model to better mimic human DLBCL disease. In the disseminated model, MLN0905 induced a highly significant survival advantage. Finally, MLN0905 was combined with a standard-of-care agent, rituximab, in the disseminated OCI LY-19 xenograft model. Combining rituximab and MLN0905 provided both a synergistic antitumor effect and a synergistic survival advantage. Our findings indicate that PLK1 inhibition leads to pharmacodynamic pHisH3 modulation and significant antitumor activity in multiple DLBCL models. These data strongly suggest evaluating PLK1 inhibitors as DLBCL anticancer agents in the clinic. ©2012 AACR.

  13. Characterization of a human platelet antigen-1a-specific monoclonal antibody derived from a B cell from a woman alloimmunized in pregnancy.

    Science.gov (United States)

    Eksteen, Mariana; Tiller, Heidi; Averina, Maria; Heide, Gøril; Kjaer, Mette; Ghevaert, Cedric; Michaelsen, Terje E; Ihle, Øistein; Husebekk, Anne; Skogen, Bjørn; Stuge, Tor B

    2015-06-15

    Human platelet Ag (HPA)-1a, located on integrin β3, is the main target for alloantibodies responsible for fetal and neonatal alloimmune thrombocytopenia (FNAIT) in the white population. There are ongoing efforts to develop an Ab prophylaxis and therapy to prevent or treat FNAIT. In this study, an mAb specific for HPA-1a, named 26.4, was derived from an immortalized B cell from an alloimmunized woman who had an infant affected by FNAIT. It is the only HPA-1a-specific human mAb with naturally paired H and L chains. Specific binding of mAb 26.4, both native and recombinant forms, to platelets and to purified integrins αIIbβ3 (from platelets) and αVβ3 (from trophoblasts) from HPA-1a(+) donors was demonstrated by flow cytometry and surface plasmon resonance technology, respectively. No binding to HPA-1a(-) platelets or integrins was detected. Moreover, the Ab binds with higher affinity to integrin αVβ3 compared with a second HPA-1a-specific human mAb, B2G1. Further in vitro experimentation demonstrated that mAb 26.4 can opsonize HPA-1a(+) platelets for enhanced phagocytosis by monocytes, inhibit binding of maternal polyclonal anti-HPA-1a Abs, and weakly inhibit aggregation of HPA-1a-heterozygous platelets, the latter with no predicted clinical relevance. Thus, mAb 26.4 is highly specific for HPA-1a and could potentially be explored for use as a prophylactic or therapeutic reagent for FNAIT intervention and as a phenotyping reagent to identify women at risk for immunization.

  14. Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Weibin [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Chen, Aizhong [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Miao, Yi [Shanghai Xuhui Central Hospital, Shanghai 200031 (China); Xia, Shengli [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Ling, Zhiyang; Xu, Ke; Wang, Tongyan [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Shu, Yuelong [Chinese Center for Disease Control and Prevention, Beijing 102206 (China); Ma, Xiaowei [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Xu, Bianli; Zhang, Jin [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Lin, Xiaojun, E-mail: linxiaojun@hualan.com [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Bian, Chao, E-mail: cbian@sibs.ac.cn [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Sun, Bing, E-mail: bsun@sibs.ac.cn [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)

    2013-01-20

    Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

  15. Phase 1 study results of the type II glycoengineered humanized anti-CD20 monoclonal antibody obinutuzumab (GA101) in B-cell lymphoma patients.

    Science.gov (United States)

    Salles, Gilles; Morschhauser, Franck; Lamy, Thierry; Milpied, Noel; Thieblemont, Catherine; Tilly, Hervé; Bieska, Gabi; Asikanius, Elina; Carlile, David; Birkett, Joe; Pisa, Pavel; Cartron, Guillaume

    2012-05-31

    Whereas the chimeric type I anti-CD20 Ab rituximab has improved outcomes for patients with B-cell malignancies significantly, many patients with non-Hodgkin lymphoma (NHL) remain incurable. Obinutuzumab (GA101) is a glycoengineered, humanized anti-CD20 type II Ab that has demonstrated superior activity against type I Abs in vitro and in preclinical studies. In the present study, we evaluated the safety, efficacy, and pharmacokinetics of GA101 in a phase 1 study of 21 patients with heavily pretreated, relapsed, or refractory CD20(+) indolent NHL. Patients received GA101 in a dose-escalating fashion (3 per cohort, range 50/100-1200/2000 mg) for 8 × 21-day cycles. The majority of adverse events (AEs) were grades 1 and 2 (114 of 132 total AEs). Seven patients reported a total of 18 grade 3 or 4 AEs. Infusion-related reactions were the most common AE, with most occurring during the first infusion and resolving with appropriate management. Three patients experienced grade 3 or 4 drug-related infusion-related reactions. The best overall response was 43%, with 5 complete responses and 4 partial responses. Data from this study suggest that GA101 was well tolerated and demonstrated encouraging activity in patients with previously treated NHL up to doses of 2000 mg. This trial is registered at www.clinicaltrials.gov as NCT00517530.

  16. Immunoglobulin genes undergo legitimate repair in human B cells not only after cis- but also frequent trans-class switch recombination.

    Science.gov (United States)

    Laffleur, B; Bardet, S M; Garot, A; Brousse, M; Baylet, A; Cogné, M

    2014-01-01

    Immunoglobulin (Ig) genes specifically recruit activation-induced deaminase (AID) for 'on-target' DNA deamination, initiating either variable (V) region somatic hypermutation, or double-strand break intermediates of class switch recombination (CSR). Such breaks overwhelmingly undergo legitimate intra-Ig repair rather than rare illegitimate and potentially oncogenic junctions outside of Ig loci. We show that in human B cells, legitimate synapsis and repair efficiently join Ig genes whether physically linked on one chromosome or located apart on both alleles. This indicates mechanisms faithfully recognizing and/or pairing loci with homology in structure and accessibility, thus licensing interchromosomal trans-CSR junctions while usually preventing illegitimate interchromosomal recombination with AID off-target genes. Physical linkage of IgH genes in cis on the same allele just increases the likelihood of legitimate repair by another fourfold. The strongest force driving CSR might thus be recognition of legitimate target genes. Formation of IgH intra-allelic loops along this process would then constitute a consequence rather than a pre-requisite of this gene-pairing process.

  17. Treatment of severe refractory autoimmune hemolytic anemia in B-cell chronic lymphocytic leukemia with alemtuzumab (humanized CD52 monoclonal antibody).

    Science.gov (United States)

    Karlsson, C; Hansson, L; Celsing, F; Lundin, J

    2007-03-01

    Progressive B-cell chronic lymphocytic leukemia (B-CLL) is often complicated by autoimmune hemolytic anemia (AIHA), which in some cases may be refractory to conventional therapy such as corticosteroids, rituximab and splenectomy. We report here on 5 patients (median age 66 years, range 59-69) with advanced B-CLL, all of whom developed severe transfusion-dependent AIHA resistant to conventional therapy and received subcutaneous (SC) or intravenous (IV) alemtuzumab, a humanized monoclonal antibody that targets the CD52 antigen as salvage treatment for AIHA. Alemtuzumab was well tolerated with only minor 'first dose' reactions. All 5 patients responded with a >or=2.0 g/dl rise in hemoglobin (Hb) concentration, in the absence of further transfusions, after a median time of 5 weeks (range 4-7), and the mean Hb increased from 7.2 g/dl at baseline to 11.9 g/dl at end of treatment. All patients remained stable, without further AIHA episodes, after a median follow-up time of 12 months with a mean Hb of 12.5 g/dl (range 12.2-12.9). For patients with severe, refractory CLL-related AIHA, who have not previously responded to conventional therapy, alemtuzumab is an effective agent.

  18. Disodium cromoglycate (DSCG) selectively inhibits IgE production and enhances IgG4 production by human B cell in vitro.

    Science.gov (United States)

    Kimata, H; Yoshida, A; Ishioka, C; Mikawa, H

    1991-01-01

    The effect of DSCG on human IgE production in vitro was studied. DSCG selectively inhibited interleukin-4 (IL-4) induced IgE production by mononuclear cells (MNC) from normal donors without affecting IgM, IgA, IgG1, IgG2 or IgG3 production. In contrast, DSCG enhanced IgG4 production. To achieve this effect, DSCG must be added to the culture at the initiation and be present throughout the entire culture period. Interferon-gamma (IFN-gamma) also inhibited IL-4-induced IgE production, but IgG4 production was not affected by IFN-gamma. Monoclonal anti-IFN-gamma antibody blocked the inhibition of IgE production by IFN-gamma, but did not block the inhibition of IgE production by DSCG. DSCG also selectively inhibited spontaneous IgE production and enhanced IgG4 production by B cells from atopic patients in the presence of T cells and monocytes. These results indicate that there is a mechanism of IgE production inhibition which is not mediated by IFN-gamma. We also found that DSCG is an excellent reagent for the study of IgE and IgG4 regulation in vitro. PMID:1904324

  19. Natural autoantibodies and complement promote the uptake of a self antigen, human thyroglobulin, by B cells and the proliferation of thyroglobulin-reactive CD4(+) T cells in healthy individuals

    DEFF Research Database (Denmark)

    Nielsen, C H; Leslie, R G; Jepsen, B S

    2001-01-01

    thyroglobulin (Tg) by human peripheral B cells in reconstituted whole blood. Significant binding of fluorescein isothiocyanate-conjugated-Tg to B cells was observed, and absorption of Tg-reactive antibodies from serum markedly reduced this uptake, as did inactivation of serum complement or blockade...... was strongly inhibited by complement inactivation and by immunoabsorption of Tg-reactive antibodies. Furthermore, this T cell response was abrogated by depletion of B cells from the PBMC culture. These data imply that uptake of complement-opsonized Tg / anti-Tg complexes and subsequent presentation of Tg by B...... of complement receptor types 1 (CR1, CD35) and 2 (CR2, CD21). T cell responsiveness to Tg was examined in a preparation of peripheral blood mononuclear cells (PBMC) cultured in the presence of autologous serum. A subset of CD4(+) T cells exhibited a dose-dependent proliferative response to Tg, which...

  20. Subclass of individual IgA-secreting human lymphocytes. Investigation of in vivo pneumococcal polysaccharide-induced and in vitro mitogen-induced blood B cells by monolayer plaque-forming cell assays

    DEFF Research Database (Denmark)

    Heilmann, C; Barington, T; Sigsgaard, T

    1988-01-01

    The subclass of individual human IgA B cells was investigated by means of monolayer plaque-forming cell assays permitting analysis of all IgA-secreting cells as well as of cells secreting IgA anti-pneumococcal polysaccharide antibody. Center cells were examined by indirect immunofluorescence...... that these Ag have an unusually high ability to activate IgA2 B cells, or that the B cells stimulated originate from lymphatic tissues with a high frequency of IgA2 committed cells....... staining with mouse mAb against either of the two IgA subclasses as primary antibodies and FITC-conjugated rabbit anti-mouse Ig as the second antibody. Blood lymphocytes spontaneously secreting IgA (mean 399/10(6) mononuclear cells) produced mainly IgA1 (73%). A similar distribution of subclasses...

  1. Bortezomib interferes with adhesion of B cell precursor acute lymphoblastic leukemia cells through SPARC up-regulation in human bone marrow mesenchymal stromal/stem cells.

    Science.gov (United States)

    Iwasa, Masaki; Miura, Yasuo; Fujishiro, Aya; Fujii, Sumie; Sugino, Noriko; Yoshioka, Satoshi; Yokota, Asumi; Hishita, Terutoshi; Hirai, Hideyo; Andoh, Akira; Ichinohe, Tatsuo; Maekawa, Taira

    2017-05-01

    The poor prognosis of adults with B cell precursor acute lymphoblastic leukemia (BCP-ALL) is attributed to leukemia cells that are protected by the bone marrow (BM) microenvironment. In the present study, we explored the pharmacological targeting of mesenchymal stromal/stem cells in BM (BM-MSCs) to eliminate chemoresistant BCP-ALL cells. Human BCP-ALL cells (NALM-6 cells) that adhered to human BM-MSCs (NALM-6/Ad) were highly resistant to multiple anti-cancer drugs, and exhibited pro-survival characteristics, such as an enhanced Akt/Bcl-2 pathway and increased populations in the G0 and G2/S/M cell cycle stages. Bortezomib, a proteasome inhibitor, interfered with adhesion between BM-MSCs and NALM-6 cells and up-regulated the matricellular protein SPARC (secreted protein acidic and rich in cysteine) in BM-MSCs, thereby reducing the NALM-6/Ad population. Inhibition of SPARC expression in BM-MSCs using a small interfering RNA enhanced adhesion of NALM-6 cells. Conversely, recombinant SPARC protein interfered with adhesion of NALM-6 cells. These results suggest that SPARC disrupts adhesion between BM-MSCs and NALM-6 cells. Co-treatment with bortezomib and doxorubicin prolonged the survival of BCP-ALL xenograft mice, with a significant reduction of leukemia cells in BM. Our findings demonstrate that bortezomib contributes to the elimination of BCP-ALL cells through disruption of their adhesion to BM-MSCs, and offer a novel therapeutic strategy for BCP-ALL through targeting of BM-MSCs.

  2. Delta Inulin Adjuvant Enhances Plasmablast Generation, Expression of Activation-Induced Cytidine Deaminase and B-Cell Affinity Maturation in Human Subjects Receiving Seasonal Influenza Vaccine.

    Directory of Open Access Journals (Sweden)

    Lei Li

    Full Text Available There is a major need for new adjuvants to improve the efficacy of seasonal and pandemic influenza vaccines. Advax is a novel polysaccharide adjuvant based on delta inulin that has been shown to enhance the immunogenicity of influenza vaccine in animal models and human clinical trials. To better understand the mechanism for this enhancement, we sought to assess its effect on the plasmablast response in human subjects. This pilot study utilised cryopreserved 7 day post-vaccination (7dpv peripheral blood mononuclear cell samples obtained from a subset of 25 adult subjects from the FLU006-12 trial who had been immunized intramuscularly with a standard dose of 2012 trivalent inactivated influenza vaccine (TIV alone (n=9 subjects or combined with 5mg (n=8 or 10mg (n=8 of Advax adjuvant. Subjects receiving Advax adjuvant had increased 7dpv plasmablasts, which in turn exhibited a 2-3 fold higher rate of non-silent mutations in the B-cell receptor CDR3 region associated with higher expression of activation-induced cytidine deaminase (AID, the major enzyme controlling BCR affinity maturation. Together, these data suggest that Advax adjuvant enhances influenza immunity in immunized subjects via multiple mechanisms including increased plasmablast generation, AID expression and CDR3 mutagenesis resulting in enhanced BCR affinity maturation and increased production of high avidity antibody. How Advax adjuvant achieves these beneficial effects on plasmablasts remains the subject of ongoing investigation.Australia New Zealand Clinical Trials Register ACTRN12612000709842 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=362709.

  3. Cell of origin associated classification of B-cell malignancies by gene signatures of the normal B-cell hierarchy.

    Science.gov (United States)

    Johnsen, Hans Erik; Bergkvist, Kim Steve; Schmitz, Alexander; Kjeldsen, Malene Krag; Hansen, Steen Møller; Gaihede, Michael; Nørgaard, Martin Agge; Bæch, John; Grønholdt, Marie-Louise; Jensen, Frank Svendsen; Johansen, Preben; Bødker, Julie Støve; Bøgsted, Martin; Dybkær, Karen

    2014-06-01

    Recent findings have suggested biological classification of B-cell malignancies as exemplified by the "activated B-cell-like" (ABC), the "germinal-center B-cell-like" (GCB) and primary mediastinal B-cell lymphoma (PMBL) subtypes of diffuse large B-cell lymphoma and "recurrent translocation and cyclin D" (TC) classification of multiple myeloma. Biological classification of B-cell derived cancers may be refined by a direct and systematic strategy where identification and characterization of normal B-cell differentiation subsets are used to define the cancer cell of origin phenotype. Here we propose a strategy combining multiparametric flow cytometry, global gene expression profiling and biostatistical modeling to generate B-cell subset specific gene signatures from sorted normal human immature, naive, germinal centrocytes and centroblasts, post-germinal memory B-cells, plasmablasts and plasma cells from available lymphoid tissues including lymph nodes, tonsils, thymus, peripheral blood and bone marrow. This strategy will provide an accurate image of the stage of differentiation, which prospectively can be used to classify any B-cell malignancy and eventually purify tumor cells. This report briefly describes the current models of the normal B-cell subset differentiation in multiple tissues and the pathogenesis of malignancies originating from the normal germinal B-cell hierarchy.

  4. The B cell antigen receptor and overexpression of MYC can cooperate in the genesis of B cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yosef Refaeli

    2008-06-01

    Full Text Available A variety of circumstantial evidence from humans has implicated the B cell antigen receptor (BCR in the genesis of B cell lymphomas. We generated mouse models designed to test this possibility directly, and we found that both the constitutive and antigen-stimulated state of a clonal BCR affected the rate and outcome of lymphomagenesis initiated by the proto-oncogene MYC. The tumors that arose in the presence of constitutive BCR differed from those initiated by MYC alone and resembled chronic B cell lymphocytic leukemia/lymphoma (B-CLL, whereas those that arose in response to antigen stimulation resembled large B-cell lymphomas, particularly Burkitt lymphoma (BL. We linked the genesis of the BL-like tumors to antigen stimulus in three ways. First, in reconstruction experiments, stimulation of B cells by an autoantigen in the presence of overexpressed MYC gave rise to BL-like tumors that were, in turn, dependent on both MYC and the antigen for survival and proliferation. Second, genetic disruption of the pathway that mediates signaling from the BCR promptly killed cells of the BL-like tumors as well as the tumors resembling B-CLL. And third, growth of the murine BL could be inhibited by any of three distinctive immunosuppressants, in accord with the dependence of the tumors on antigen-induced signaling. Together, our results provide direct evidence that antigenic stimulation can participate in lymphomagenesis, point to a potential role for the constitutive BCR as well, and sustain the view that the constitutive BCR gives rise to signals different from those elicited by antigen. The mouse models described here should be useful in exploring further the pathogenesis of lymphomas, and in preclinical testing of new therapeutics.

  5. Calmodulin protects cells from death under normal growth conditions and mitogenic starvation but plays a mediating role in cell death upon B-cell receptor stimulation

    DEFF Research Database (Denmark)

    Schmalzigaug, R; Ye, Q; Berchtold, M W

    2001-01-01

    MII gene causes the intracellular CaM level to decrease by 60%. CaMII-/- cells grow more slowly and die more frequently as compared to wild type (wt) cells but do not exhibit significant differences in their cell cycle profile. Both phenotypes are more pronounced at reduced serum concentrations. Upon......Calmodulin (CaM) is the main intracellular Ca2+ sensor protein responsible for mediating Ca2+ triggered processes. Chicken DT40 lymphoma B cells express CaM from the two genes, CaMI and CaMII. Here we report the phenotypes of DT40 cells with the CaMII gene knocked out. The disruption of the Ca...... stimulation of the B-cell receptor (BCR), the resting Ca2+ levels remain elevated after the initial transient in CaMII-/- cells. Despite higher Ca2+ resting levels, the CaMII-/- cells are partially protected from BCR induced apoptosis indicating that CaM plays a dual role in apoptotic processes....

  6. 人扁桃体和外周血中B细胞亚群、表型和功能的比较%Comparison of subpopulations, phenotypes and functions of human B cells in tonsillar mononuclear cells and PBMCs

    Institute of Scientific and Technical Information of China (English)

    冯敛; 李祖望; 李华斌; 吴长有

    2011-01-01

    目的:比较观察人扁桃体和外周血中B细胞的亚群分布、表型及功能特征.方法:分离人扁桃体单个核细胞和外周血PBMCs,流式细胞术检测其B细胞表面分子的表达;将人扁桃体单个核细胞和外周血PBMCs进行体外培养后,ELISA法检测培养上清中免疫球蛋白(Ig)含量.结果:流式细胞术检测结果表明,与PBMCs中B细胞亚群不同,扁桃体单个核细胞中含有较高比例的生发中心细胞(GC cells),且初始B细胞(naive B cells)比例较低.与PBMCs相比,扁桃体单个核细胞中CD19+CD38(high)CD20+浆细胞的比例较高,但两者B细胞表面IgM和IgG表达的差异并不显著(P>0.05).扁桃体B细胞上表达CD69的水平明显高于PBMCs中B细胞,而CD25在扁桃体及PBMCs中B细胞上均不表达或表达甚微.ELISA检测结果表明,未经刺激的扁桃体单个核细胞产生IgG的含量高于PBMCs,IgA和IgM含量与PBMCs相比,差异不显著.结论:人扁桃体和外周血中B细胞亚群分布及功能特征均存在一定差别,为进一步研究B细胞如何在淋巴组织中发挥免疫功能提供了实验依据.%In this study, we aimed to compare the subpopulations, phenotypes and functions of human B cells in tonsillar mononuclear cells and PBMCs. Firstly, tonsillar mononuclear cells and PBMCs were isolated and the surface markers on B cells were detected by flow cytometry (FCM). Tonsillar mononuclear cells and PBMCs were then cultured for 7 days, and the production of immunoglobulins in supernatants was tested by ELISA. FCM analysis revealed that increased frequencies of germinal center cells (GC cells) were existed in tonsillar B cell subsets compared with that in PBMCs, and the proportion of naive B cells was lower in tonsillar B cells than that in PBMCs. Different from what observed in PBMCs, higher frequencies of CD19+CD38highCD20+/- plasma cells were existed in tonsillar mononuclear cells, but the expression of IgM and IgG on tonsillar B cells were similar

  7. B-cell receptor-associated protein 31 regulates human embryonic stem cell adhesion, stemness, and survival via control of epithelial cell adhesion molecule.

    Science.gov (United States)

    Kim, Won-Tae; Seo Choi, Hong; Min Lee, Hyun; Jang, Young-Joo; Ryu, Chun Jeih

    2014-10-01

    B-Cell receptor-associated protein 31 (BAP31) regulates the export of secreted membrane proteins from the endoplasmic reticulum (ER) to the downstream secretory pathway. Previously, we generated a monoclonal antibody 297-D4 against the surface molecule on undifferentiated human embryonic stem cells (hESCs). Here, we found that 297-D4 antigen was localized to pluripotent hESCs and downregulated during early differentiation of hESCs and identified that the antigen target of 297-D4 was BAP31 on the hESC-surface. To investigate the functional role of BAP31 in hESCs, BAP31 expression was knocked down by small interfering RNA. BAP31 depletion impaired hESC self-renewal and pluripotency and drove hESC differentiation into multicell lineages. BAP31 depletion hindered hESC proliferation by arresting cell cycle at G0/G1 phase and inducing caspase-independent cell death. Interestingly, BAP31 depletion reduced hESC adhesion to extracellular matrix (ECM). Analysis of cell surface molecules showed decreased expression of epithelial cell adhesion molecule (EpCAM) in BAP31-depleted hESCs, while ectopic expression of BAP31 elevated the expression of EpCAM. EpCAM depletion also reduced hESC adhesion to ECM, arrested cell cycle at G0/G1 phase and induced cell death, producing similar effects to those of BAP31 depletion. BAP31 and EpCAM were physically associated and colocalized at the ER and cell surface. Both BAP31 and EpCAM depletion decreased cyclin D1 and E expression and suppressed PI3K/Akt signaling, suggesting that BAP31 regulates hESC stemness and survival via control of EpCAM expression. These findings provide, for the first time, mechanistic insights into how BAP31 regulates hESC stemness and survival via control of EpCAM expression.

  8. DNA damage and DNA damage response in human bronchial epithelial BEAS-2B cells following exposure to 2-nitrobenzanthrone and 3-nitrobenzanthrone: role in apoptosis.

    Science.gov (United States)

    Oya, Elisabeth; Ovrevik, Johan; Arlt, Volker M; Nagy, Eszter; Phillips, David H; Holme, Jørn A

    2011-11-01

    Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are mutagenic and carcinogenic environmental pollutants found in diesel exhaust and on urban air pollution particles. In the present study, human bronchial epithelial BEAS-2B cells were exposed to 2-nitrobenzanthrone (2-NBA) and 3-nitrobenzanthrone (3-NBA). DNA damage responses were compared to those observed after exposure to 1-nitropyrene (1-NP) and benzo[a]pyrene (B[a]P). Examination by microscopy revealed that 3-NBA was the most potent toxic compound while weaker responses were observed with 1-NP and B[a]P. Most interestingly, 2-NBA did not induce cell death or any other stress-related responses. 3-NBA induced a typical apoptotic cell death judged by nuclear condensation and little plasma membrane damage as well as cleavage of caspase 3 and poly-(ADP-ribose) polymerase (PARP). Exposure to 3-NBA resulted in an accumulation of cells in S-phase, and further analysis by Western blotting, immunocytochemistry and flow cytometry revealed that 3-NBA induced a DNA damage response characterized by phosphorylation of ATM (ataxia-telangiectasia mutated), checkpoint kinase (Chk) 2/Chk1, H2AX and p53. The p53 inhibitor pifithrin-α inhibited 3-NBA-induced apoptosis while small effects were seen using pifithrin-μ, suggesting that 3-NBA-induced cell death is a result of transcriptional activation of p53. In conclusion, 3-NBA is a potent inducer of apoptosis, which seemed to be triggered by the DNA damage response. Furthermore, a change of the nitro-group to the second position (i.e. 2-NBA) dramatically changed the cellular reactivity of the compound.

  9. Human Leukocyte Antigen Class I and II Alleles and Overall Survival in Diffuse Large B-Cell Lymphoma and Follicular Lymphoma

    Directory of Open Access Journals (Sweden)

    Yani Lu

    2011-01-01

    Full Text Available Genetic variation in the 6p21 chromosomal region, including human leukocyte antigen (HLA genes and tumor necrosis factor (TNF, has been linked to both etiology and clinical outcomes of lymphomas. We estimated the effects of HLA class I (A, B, and C, class II DRB1 alleles, and the ancestral haplotype (AH 8.1 (HLAA*01-B*08-DRB1*03-TNF-308A on overall survival (OS among patients with diffuse large B-cell lymphoma (DLBCL and follicular lymphoma (FL in a population-based study of non-Hodgkin lymphoma. During a median followup of 89 months, 31% (52 of 166 DLBCL and 28% (46 of 165 FL patients died. Using multivariate Cox regression models, we observed statistically significant associations between genetic variants and survival: HLA-Cw*07:01 was associated with poorer OS among DLBCL patients (Hazard ratio [HR] = 1.76, 95% confidence interval [CI] = 1.01–3.05; HLA-A*01:01 was associated with poorer OS (HR = 2.23, 95% CI = 1.24–4.01, and HLA-DRB1*13 (HR = 0.12, 95% CI = 0.02–0.90 and HLA-B Bw4 (HR = 0.36, 95% CI = 0.20–0.63 with better OS among FL patients. These results support a role for HLA in the prognosis of DLBCL and FL and represent a promising class of prognostic factors that warrants further evaluation.

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

    Science.gov (United States)

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

    2016-05-01

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

  11. Sirolimus inhibits growth of human hepatoma cells alone or combined with tacrolimus, while tacrolimus promotes cell growth

    Institute of Scientific and Technical Information of China (English)

    Guido Schumacher; Marijke Oidtmann; Anne Rueggeberg; Dietmar Jacob; Sven Jonas; Jan M. Langrehr; Ruth Neuhaus; Marcus Bahra; Peter Neuhaus

    2005-01-01

    AIM: Standard immunosuppression after organ transplantation stimulates tumor growth. Sirolimus has a strong antiproliferative and a tumor inhibiting effect. The purpose is to assess the effect on tumor growth of the immunosuppressive compounds sirolimus and tacrolimus alone and in combination on cells of human hepatocellular carcinoma.METHODS: We used the human cell lines SK-Hep 1 and Hep 3B derived from hepatocellular carcinoma. Proliferation analyses after treatment with sirolimus, tacrolimus, or the combination of both were performed. FACS analyses were done to reveal cell cycle changes and apoptotic cell death. The expression of apoptosis-related proteins was estimated by Western blots.RESULTS: Sirolimus alone or combined with tacrolimus inhibited the growth of both cell lines after 5 d by up to 35% in SK-Hep 1 cells, and by up to 68% in Hep 3B cells at 25 ng/mL. Tacrolimus alone stimulated the growth by 12% after 5 ng/mL and by 25% after 25 ng/mL in Hep 3B cells. We found an increase of apoptotic Hep 3B cells from 6 to 16%, and a G1-arrest in SK-Hep 1 cells with an increase of cells from 61 to 82%, when sirolimus and tacrolimus were combined. Bcl-2 was down-regulated in Hep 3B, but not in SK-Hep 1 cells after combined treatment.CONCLUSION: Sirolimus appears to inhibit the growth of hepatocellular carcinoma cells alone and in combination with tacrolimus. Sirolimus seems to inhibit the growth stimulation of tacrolimus.

  12. Identification of EZH2 and EZH1 small molecule inhibitors with selective impact on diffuse large B cell lymphoma cell growth.

    Science.gov (United States)

    Garapaty-Rao, Shivani; Nasveschuk, Christopher; Gagnon, Alexandre; Chan, Eric Y; Sandy, Peter; Busby, Jennifer; Balasubramanian, Srividya; Campbell, Robert; Zhao, Feng; Bergeron, Louise; Audia, James E; Albrecht, Brian K; Harmange, Jean-Christophe; Cummings, Richard; Trojer, Patrick

    2013-11-21

    The histone methyltransferase enhancer of Zeste homolog 2 (EZH2) is a candidate oncogene due to its prevalent overexpression in malignant diseases, including late stage prostate and breast cancers. The dependency of cancer cells on EZH2 activity is also predicated by recurrent missense mutations residing in the catalytic domain of EZH2 that have been identified in subtypes of diffuse large B cell lymphoma, follicular lymphoma and melanoma. Herein, we report the identification of a highly selective small molecule inhibitor series of EZH2 and EZH1. These compounds inhibit wild-type and mutant versions of EZH2 with nanomolar potency, suppress global histone H3-lysine 27 methylation, affect gene expression, and cause selective proliferation defects. These compounds represent a structurally distinct EZH2 inhibitor chemotype for the exploration of the role of Polycomb Repressive Complex 2-mediated H3K27 methylation in various biological contexts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Dengue Virus Directly Stimulates Polyclonal B Cell Activation

    Science.gov (United States)

    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

  14. Human Adipose Tissue-Derived Mesenchymal Stem Cells Abrogate Plasmablast Formation and Induce Regulatory B Cells Independently of T Helper Cells

    NARCIS (Netherlands)

    Franquesa, M.; Mensah, F. K.; Huizinga, R.; Strini, T.; Boon, L.; Lombardo, E.; DelaRosa, O.; Laman, J. D.; Grinyo, J. M.; Weimar, W.; Betjes, M. G. H.; Baan, C. C.; Hoogduijn, M. J.

    2015-01-01

    Mesenchymal or stromal stem cells (MSC) interact with cells of the immune system in multiple ways. Modulation of the immune system by MSC is believed to be a therapeutic option for autoimmune disease and transplant rejection. In recent years, B cells have moved into the focus of the attention as tar

  15. Schistosomes induce regulatory features in human and mouse CD1d hi B cells: Inhibition of allergic inflammation by IL-10 and regulatory T cells

    NARCIS (Netherlands)

    L.E.P.M. van der Vlugt (Luciën); L.A. Labuda (Lucja); A. Ozir-Fazalalikhan (Arifa); E. Lievers (Ellen); A.K. Gloudemans (Anouk); K.-Y. Liu (Kit-Yeng); T.A. Barr (Tom); T. Sparwasser (Tim); L. Boon (Louis); U.A. Ngoa (Ulysse Ateba); E.N. Feugap (Eliane Ngoune); A.A. Adegnika (Ayola); P.G. Kremsner (Peter); D. Gray (David); M. Yazdanbakhsh (Maria); H.H. Smits (Hermelijn)

    2012-01-01

    textabstractChronic helminth infections, such as schistosomes, are negatively associated with allergic disorders. Here, using B cell IL-10-deficient mice, Schistosoma mansoni-mediated protection against experimental ovalbumin-induced allergic airway inflammation (AAI) was shown to be specifically de

  16. Human Adipose Tissue-Derived Mesenchymal Stem Cells Abrogate Plasmablast Formation and Induce Regulatory B Cells Independently of T Helper Cells

    NARCIS (Netherlands)

    Franquesa, M.; Mensah, F. K.; Huizinga, R.; Strini, T.; Boon, L.; Lombardo, E.; DelaRosa, O.; Laman, J. D.; Grinyo, J. M.; Weimar, W.; Betjes, M. G. H.; Baan, C. C.; Hoogduijn, M. J.

    Mesenchymal or stromal stem cells (MSC) interact with cells of the immune system in multiple ways. Modulation of the immune system by MSC is believed to be a therapeutic option for autoimmune disease and transplant rejection. In recent years, B cells have moved into the focus of the attention as

  17. Lymphoid-Like Structures with Distinct B Cell Areas in Kidney Allografts are not Predictive for Graft Rejection. A Non-human Primate Study.

    Science.gov (United States)

    Jonker, Margreet; Wubben, Jacqueline A M; 't Hart, Bert A; Haanstra, Krista G

    2015-12-01

    Kidney allograft biopsies were analyzed for the presence of B cell clusters/aggregates using CD20 staining. Few B cells were found in the diffuse interstitial infiltrates, but clusters of B cells were found in nodular infiltrates. These nodular infiltrates were smaller shortly after transplantation, and their size increased over time. At the time of clinical rejection, the nodules often presented as tertiary lymphoid structures (TLS) with lymphoid-like follicles. The presence of small B cell clusters during the first 2 months after transplantation was not associated with early rejection. Even in animals that did not reject their allograft, TLS-like structures were present and could disappear over time. Although TLS were more often found in samples with interstitial fibrosis and tubular atrophy (IFTA), TLS were also present in samples without IFTA. The presence and density of clusters resembling tertiary lymphoid structures most likely reflect an ongoing immune response inside the graft and do not necessarily signify a poor graft outcome or IFTA.

  18. Regulation of IL-17A production is distinct from IL-17F in a primary human cell co-culture model of T cell-mediated B cell activation.

    Directory of Open Access Journals (Sweden)

    Andrew C Melton

    Full Text Available Improper regulation of B cell responses leads to excessive production of antibodies and contributes to the development of autoimmune disease. T helper 17 (Th17 cells also drive the development of autoimmune disease, but the role of B cells in shaping Th17 cell-mediated immune responses, as well as the reciprocal regulation of B cell responses by IL-17 family cytokines, remains unclear. The aim of this study was to characterize the regulation of IL-17A and IL-17F in a model of T cell-dependent B cell activation. Stimulation of primary human B cell and peripheral blood mononuclear cell (BT co-cultures with α-IgM and a non-mitogenic concentration of superantigens for three days promoted a Th17 cell response as evidenced by increased expression of Th17-related gene transcripts, including Il17f, Il21, Il22, and Il23r, in CD4 T cells, as well as the secretion of IL-17A and IL-17F protein. We tested the ability of 144 pharmacologic modulators representing 91 different targets or pathways to regulate IL-17A and IL-17F production in these stimulated BT co-cultures. IL-17A production was found to be preferentially sensitive to inhibition of the PI3K/mTOR pathway, while prostaglandin EP receptor agonists, including PGE2, increased IL-17A concentrations. In contrast, the production of IL-17F was inhibited by PGE2, but selectively increased by TLR2 and TLR5 agonists. These results indicate that IL-17A regulation is distinct from IL-17F in stimulated BT co-cultures and that this co-culture approach can be used to identify pathway mechanisms and novel agents that selectively inhibit production of IL-17A or IL-17F.

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

    Science.gov (United States)

    Zouali, Moncef; Richard, Yolande

    2011-01-01

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

  20. B-cell responses to HIV infection.

    Science.gov (United States)

    Moir, Susan; Fauci, Anthony S

    2017-01-01

    The induction of neutralizing antibodies directed against the human immunodeficiency virus (HIV) has received considerable attention in recent years, in part driven by renewed interest and opportunities for antibody-based strategies for prevention such as passive transfer of antibodies and the development of preventive vaccines, as well as immune-based therapeutic interventions. Advances in the ability to screen, isolate, and characterize HIV-specific antibodies have led to the identification of a new generation of potent broadly neutralizing antibodies (bNAbs). The majority of these antibodies have been isolated from B cells of chronically HIV-infected individuals with detectable viremia. In this review, we provide insight into the phenotypic and functional attributes of human B cells, with a focus on HIV-specific memory B cells and plasmablasts/cells that are responsible for sustaining humoral immune responses against HIV. We discuss the abnormalities in B cells that occur in HIV infection both in the peripheral blood and lymphoid tissues, especially in the setting of persisting viremia. Finally, we consider the opportunities and drawbacks of intensively interrogating antibodies isolated from HIV-infected individuals to guide strategies aimed at developing effective antibody-based vaccine and therapeutic interventions for HIV. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  1. Laser-based microdissection of single cells from tissue sections and PCR analysis of rearranged immunoglobulin genes from isolated normal and malignant human B cells.

    Science.gov (United States)

    Küppers, Ralf; Schneider, Markus; Hansmann, Martin-Leo

    2013-01-01

    Normal and malignant B cells carry rearranged immunoglobulin (Ig) variable region genes, which due to their practically limitless diversity represent ideal clonal markers for these cells. We describe here an approach to isolate single cells from frozen tissue sections by microdissection using a laser-based method. From the isolated cells rearranged IgH and Igκ genes are amplified in a semi-nested PCR approach, using a collection of V gene family-specific primers recognizing nearly all V gene segments together with primers for the J gene segments. By sequence analysis of V genes from distinct cells, the clonal relationship of the B lineage cells can unequivocally be determined and related to the histological distribution of the cells. The approach is also useful to determine V, D, and J gene usage. Moreover, the presence and pattern of somatic Ig V gene mutations give valuable insight into the stage of differentiation of the B cells.

  2. Brucella abortus-infected B cells induce osteoclastogenesis.

    Science.gov (United States)

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

    2016-09-01

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

  3. B cell line epitopes prediction of human cytomegalovirus glycoprotein B%人巨细胞病毒包膜糖蛋白B线性B细胞抗原表位的预测

    Institute of Scientific and Technical Information of China (English)

    闫晶晶; 吕茂民; 赵雄; 尹惠琼; 章金刚

    2015-01-01

    目的:通过生物信息学方法分析人巨细胞病毒( human cytomegalovirus ,HCMV)包膜糖蛋白B ( glycopro-tein B,gB)的结构及理化特性,预测gB的线性B细胞抗原表位。方法基于HCMV gB的序列,利用两种在线B细胞表位预测程序及DNAstar软件对gB进行预测;利用SWISS-MODEL服务器同源构建gB三级结构模型,进行进一步验证。结果与结论综合多项分析,预测得到HCMVgB的多个线性B细胞表位,为后续验证其优势中和表位,建立富含高效价中和抗体的原料血浆的筛选方法奠定了基础。%Objective To predict the B cell line epitopes of human cytomegalovirus glycoprotein (gB)by analyzing its structure and physicochemical properties using bioinformatics approaches .Methods Based on the sequence of the HCMV gB,the probable B cell epitopes are predicted using two online prediction programs and DNAstar software .Meanwhile,the tertiary structure of gB was constructed by homologous modeling with the assistance of SWISS -MODEL server to rule out im-possible B cell epitopes .Results and Conclusion The B cell line epitopes of gB are predicted , which provides a theoreti-cal basis for further verification of gB immunodominant epitopes and screening the source plasma with high HCMV IgG titer .

  4. Dispersion of Human Capital and Economic Growth

    OpenAIRE

    Jungsoo Park

    2004-01-01

    Based on a theoretical consideration of human capital production technology, this study empirically investigates the growth implication of dispersion of population distribution in terms of educational attainment levels. Based on a pooled 5-year interval time-series data set of 94 developed and developing countries for 1960 to 1995, the study finds that dispersion index as well as average index of human capital positively influences productivity growth. Given limited social resources for human...

  5. Nivolumab With or Without Varlilumab in Treating Patients With Relapsed or Refractory Aggressive B-cell Lymphomas

    Science.gov (United States)

    2017-03-13

    Activated B-Cell-Like Diffuse Large B-Cell Lymphoma; ALK-Positive Large B-Cell Lymphoma; Atypical Burkitt/Burkitt-Like Lymphoma; Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; Epstein-Barr Virus Positive Diffuse Large B-Cell Lymphoma of the Elderly; Epstein-Barr Virus-Positive Mucocutaneous Ulcer; Germinal Center B-Cell-Like Diffuse Large B-Cell Lymphoma; High-Grade B-Cell Lymphoma With MYC and BCL2 and/or BCL6 Rearrangements; Human Herpesvirus-8-Positive Neoplastic Cells Present; Intravascular Large B-Cell Lymphoma; MYC-Negative B-Cell Lymphoma With 11q Aberration Resembling Burkitt Lymphoma; Plasmablastic Lymphoma; Primary Cutaneous Diffuse Large B-Cell Lymphoma; Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type; Primary Diffuse Large B-Cell Lymphoma of the Central Nervous System; Primary Effusion Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Lymphomatoid Granulomatosis; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Skin Ulcer; Small Intestinal B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Burkitt Lymphoma; T-Cell/Histiocyte-Rich Large B-Cell Lymphoma

  6. Pro-B cells propagated in stromal cell-free cultures reconstitute functional B-cell compartments in immunodeficient mice.

    Science.gov (United States)

    von Muenchow, Lilly; Tsapogas, Panagiotis; Albertí-Servera, Llucia; Capoferri, Giuseppina; Doelz, Marianne; Rolink, Hannie; Bosco, Nabil; Ceredig, Rhodri; Rolink, Antonius G

    2017-02-01

    Up to now long-term in vitro growth of pro-B cells was thought to require stromal cells. However, here we show that fetal liver (FL) and bone marrow (BM) derived pro-B cells can be propagated long-term in stromal cell-free cultures supplemented with IL-7, stem cell factor and FLT3 ligand. Within a week, most cells expressed surface CD19, CD79A, λ5, and VpreB antigens and had rearranged immunoglobulin D-J heavy chain genes. Both FL and BM pro-B cells reconstituted the B-cell compartments of immuno-incompetent Rag2-deficient mice, with FL pro-B cells generating follicular, marginal zone (MZB) and B1a B cells, and BM pro-B cells giving rise mainly to MZB cells. Reconstituted Rag2-deficient mice generated significant levels of IgM and IgG antibodies to a type II T-independent antigen; mice reconstituted with FL pro-B cells generated surprisingly high IgG1 titers. Finally, we show for the first time that mice reconstituted with mixtures of pro-B and pro-T cells propagated in stromal cell-free in vitro cultures mounted a T-cell-dependent antibody response. This novel stromal cell-free culture system facilitates our understanding of B-cell development and might be applied clinically. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Stromal cell-derived factor-1/CXCL12 contributes to MMTV-Wnt1 tumor growth involving Gr1+CD11b+ cells.

    Directory of Open Access Journals (Sweden)

    Bob Y Liu

    Full Text Available BACKGROUND: Histological examinations of MMTV-Wnt1 tumors reveal drastic differences in the tumor vasculature when compared to MMTV-Her2 tumors. However, these differences have not been formally described, nor have any angiogenic factors been implicated to be involved in the Wnt1 tumors. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that MMTV-Wnt1 tumors were more vascularized than MMTV-Her2 tumors, and this correlated with significantly higher expression of a CXC chemokine, stromal cell-derived factor-1 (SDF1/CXCL12 but not with VEGFA. Isolation of various cell types from Wnt1 tumors revealed that SDF1 was produced by both tumor myoepithelial cells and stromal cells, whereas Her2 tumors lacked myoepithelial cells and contained significantly less stroma. The growth of Wnt1 tumors, but not Her2 tumors, was inhibited by a neutralizing antibody to SDF1, but not by neutralization of VEGFA. Anti-SDF1 treatment decreased the proportion of infiltrating Gr1(+ myeloid cells in the Wnt1 tumors, which correlated with a decrease in the percentage of endothelial cells. The involvement of Gr1(+ cells was evident from the retardation of Wnt1 tumor growth following in vivo depletion of these cells with an anti-Gr1-specific antibody. This degree of inhibition on Wnt1 tumor growth was comparable, but not additive, to the effect observed with anti-SDF1, indicative of overlapping mechanisms of inhibition. In contrast, Her2 tumors were not affected by the depletion of Gr1(+ cells. CONCLUSIONS/SIGNIFICANCE: We demonstrated that SDF1 is important for Wnt1, but not for HER2, in inducing murine mammary tumor and the role of SDF1 in tumorigenesis involves Gr1(+ myeloid cells to facilitate growth and/or angiogenesis.

  8. Differences in modifications of cytoplasmic free Ca2+ concentration and 86Rb+ influx in human neoplastic B cells by antibodies to mu- relative to delta-Ig heavy chains.

    Science.gov (United States)

    Heikkilä, R; Ruud, E; Funderud, S; Godal, T

    1985-01-01

    Cytoplasmic free Ca2+ concentration and influx of 86Rb+ (K+ analogue) were determined during the first minutes after stimulation of neoplastic human B cells and B cell lines by antibodies to surface Ig. The Ca2+ concentration increased in the great majority of samples (41 of 48). All of four B cell lines also responded, providing formal evidence that accessory cells are not required for this early, surface Ig-mediated event. Antibodies to delta as well as mu, heavy chains (anti-delta and anti-mu) could induce both Ca2+ and 86Rb+ responses. 86Rb+ responders were found within the group of Ca2+ responders, but no quantitative relation was observed between the two responses. In cells expressing both sIgM and sIgD, antibodies to delta heavy chains were more potent than those to mu heavy chains in inducing Ca2+ responses, whereas the opposite pattern was seen with regard to 86Rb+ responses. These results demonstrate that sIgM and sIgD can deliver different biochemical signals to the cell. PMID:3921300

  9. Employment growth, human capital and educational levels

    DEFF Research Database (Denmark)

    Hansen, Høgni Kalsø; Winther, Lars

    2015-01-01

    human capital in understanding regional growth. We examine to what extent different labour competences and capabilities relate to municipal employment growth using nine stratified, educational categories as proxies for different levels of human capital. Dividing municipalities into four spatial...... categories ranging from the urban to the peripheral, we conclude that there is a strong spatial distinction of educational structures with an urban bias, and that educational categories other than academic human capital can make an important contribution to our understanding of what drives employment growth...

  10. Effect of B-cell receptor engagement on CD40-stimulated B cells

    NARCIS (Netherlands)

    Schilizzi, BM; Boonstra, R; The, TH; deLeij, LFMH

    1997-01-01

    Activation of human B cells in vitro either by cross-linking of surface immunoglobulins (sig) or by triggering CD40 antigen, in the presence of interleukin-10 (IL-10) and interleukin-2 (IL-2), may result in high levels of immunoglobulin secretion in vitro. We studied the combined effects of ligation

  11. Human Capital, Fertility, and Economic Growth

    OpenAIRE

    Gary S. Becker; Murphy, Kevin M.; Robert F. Tamura

    1990-01-01

    Our model of growth departs from both the Malthusian and neoclassical approaches by including investments in human capital. We assume, crucially, that rates of return on human capital investments rise, rather than, decline, as the stock of human capital increases, until the stock becomes large. This arises because the education sector uses human capital note intensively than either the capital producing sector of the goods producing sector. This produces multiple steady scares: an undeveloped...

  12. Anticancer Effect of Curcumin on B Cell non- Hodgkin's Lymphoma

    Institute of Scientific and Technical Information of China (English)

    SUN Chunyan; LIU Xinyue; CHEN Yan; LIU Fang

    2005-01-01

    To explore the anticancer effect of curcumin on human B cell non-Hodgkin's lymphoma and compare its effects on human B cell non-Hodgkin's lymphoma cells and normal peripheral blood mononuclear cells (NPBMNCs). MTT assay was used to study the effect of curcumin on the growth of Raji cells and NPBMNCs. The effect of curcumin on the apoptosis of Raji cells and NPBMNC were studied by flow cytometry and TDT-mediated dUTP nick and labeling (TUNEL). The effect of curcumin on the cell cycle of Raji cells were examined by propidium iodide staining flow cytometry. The results showed that curcumin strongly inhibited ±1.82 μmol/L and curcumin induced Raji cell apoptosis in a time- and dose-dependent manner. Raji cells treated with curcumin showed curcumin did not demonstrate apparent proliferation inhibition and apoptosis induction in NPBMNCs. It was concluded that curcumin is able to inhibit the proliferation of Raji cells by regulating the cell cycle and inducing the cell apoptosis. Morever, curcumin has low toxicity on NPBMNCs but can selectively induce apoptosis in Raji cells.

  13. Hormones and Human and Nonhuman Primate Growth.

    Science.gov (United States)

    Bernstein, Robin Miriam

    2017-01-01

    The aim of this paper was to review information pertaining to the hormonal regulation of nonhuman primate growth, with specific focus on the growth hormone (GH)-insulin-like growth factor (IGF) axis and adrenal androgens. Hormones of the GH-IGF axis are consistently associated with measures of growth - linear, weight, or both - during the growth period; in adulthood, concentrations of IGF-I, IGF-binding protein-3, and GH-binding protein are not associated with any measures of size. Comparing patterns of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) may be especially relevant for understanding whether the childhood stage of growth and development is unique to humans and perhaps other apes. Genetic, hormonal, and morphological data on adrenarche in other nonhuman primate species suggest that this endocrine transition is delayed in humans, chimpanzees, and possibly gorillas, while present very early in postnatal life in macaques. This suggests that although perhaps permitted by an extension of the pre-adolescent growth period, childhood builds upon existing developmental substrates rather than having been inserted de novo into an ancestral growth trajectory. Hormones can provide insight regarding the evolution of the human growth trajectory. © 2017 S. Karger AG, Basel.

  14. Molecular programming of B cell memory.

    Science.gov (United States)

    McHeyzer-Williams, Michael; Okitsu, Shinji; Wang, Nathaniel; McHeyzer-Williams, Louise

    2011-12-09

    The development of high-affinity B cell memory is regulated through three separable phases, each involving antigen recognition by specific B cells and cognate T helper cells. Initially, antigen-primed B cells require cognate T cell help to gain entry into the germinal centre pathway to memory. Once in the germinal centre, B cells with variant B cell receptors must access antigens and present them to germinal centre T helper cells to enter long-lived memory B cell compartments. Following antigen recall, memory B cells require T cell help to proliferate and differentiate into plasma cells. A recent surge of information - resulting from dynamic B cell imaging in vivo and the elucidation of T follicular helper cell programmes - has reshaped the conceptual landscape surrounding the generation of memory B cells. In this Review, we integrate this new information about each phase of antigen-specific B cell development to describe the newly unravelled molecular dynamics of memory B cell programming.

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

    Directory of Open Access Journals (Sweden)

    Moncef eZOUALI

    2011-12-01

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

  16. MUTATION ON WD DIPEPTIDE MOTIFS OF THE p48 SUBUNIT OF CHROMATIN ASSEMBLY FACTOR-1 CAUSING VIABILITY AND GROWTH OF DT40 CHICKEN B CELL LINE

    Directory of Open Access Journals (Sweden)

    Ahyar Ahmad

    2010-07-01

    Full Text Available Chromatin assembly factor-1 (CAF-1, a protein complex consisting of three subunits, p150, p60, and p48, is highly conserved from yeast to humans and facilitated nucleosome assembly of newly replicated DNA. The p48 subunit, CAF-1p48 (p48, with seven WD (Trp-Asp repeat motifs, is a member of the WD protein family. The immunoprecipitation experiment revealed that ß-propeller structure of p48 was less stringent for it's binding to HDAC-1, but more stringent for its binding to both histones H4 and CAF-1p60 but not to ASF-1, indicating that the proper ß-propeller structure of p48 is essential for the binding to these two proteins histone H4 and CAF-1p60. Complementation experiments, involving missense and truncated mutants of FLAG-tagged p48, revealed that mutations of every of seven WD dipeptide motifs, like both the N-terminal and C-terminal truncated mutations, could not rescue for the tet-induced lethality. These results indicate not only that p48 is essential for the viability of vertebrate cells, although the yeast p48 homolog is nonessential, but also that all the seven WD dipeptide motifs are necessary for the maintenance of the proper structure of p48 that is fundamentally important for cell viability.   Keywords: Chromatin assembly factor-1, complementation experiments, viability

  17. Human Capital Composition and Economic Growth

    Science.gov (United States)

    Tsai, Chun-Li; Hung, Ming-Cheng; Harriott, Kevin

    2010-01-01

    The objective of this paper is to analyze the effect of various compositions of human capital on economic growth. We construct alternative measures of human capital composition using five fields of study. In each instance, the measure represents the number of graduates in the respective field as a percentage of all graduates. The measures are as…

  18. Human Capital Composition and Economic Growth

    Science.gov (United States)

    Tsai, Chun-Li; Hung, Ming-Cheng; Harriott, Kevin

    2010-01-01

    The objective of this paper is to analyze the effect of various compositions of human capital on economic growth. We construct alternative measures of human capital composition using five fields of study. In each instance, the measure represents the number of graduates in the respective field as a percentage of all graduates. The measures are as…

  19. Human Capital, Technology, and Economic Growth

    Directory of Open Access Journals (Sweden)

    Chindo Sulaiman

    2015-11-01

    Full Text Available This article investigated the impact of human capital and technology on economic growth in Nigeria. We employed annual time series data for the period of 35 years (1975-2010 and applied autoregressive distributed lag approach to cointegration to examine the relationship between human capital, technology, and economic growth. Two proxies of human capital (secondary and tertiary school enrollments were used in two separate models. The cointegration result revealed that all the variables in the two separate models were cointegrated. Furthermore, the results of the two estimated models showed that human capital in form in secondary and tertiary school enrollments have had significant positive impact on economic growth. More so, technology also shows significant positive impact on economic growth. In a nutshell, both human capital and technology are important determinants of growth in Nigeria. Therefore, improvement of the educational sector and more funding for research and development (R&D to encourage innovations are needed to facilitate Nigeria’s sustained economic growth.

  20. Inhibition of MALT1 protease activity is selectively toxic for activated B cell-like diffuse large B cell lymphoma cells.

    Science.gov (United States)

    Ferch, Uta; Kloo, Bernhard; Gewies, Andreas; Pfänder, Vera; Düwel, Michael; Peschel, Christian; Krappmann, Daniel; Ruland, Jürgen

    2009-10-26

    Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoma in humans. The aggressive activated B cell-like (ABC) subtype of DLBCL is characterized by constitutive NF-kappaB activity and requires signals from CARD11, BCL10, and the paracaspase MALT1 for survival. CARD11, BCL10, and MALT1 are scaffold proteins that normally associate upon antigen receptor ligation. Signal-induced CARD11-BCL10-MALT1 (CBM) complexes couple upstream events to IkappaB kinase (IKK)/NF-kappaB activation. MALT1 also possesses a recently recognized proteolytic activity that cleaves and inactivates the negative NF-kappaB regulator A20 and BCL10 upon antigen receptor ligation. Yet, the relevance of MALT1 proteolytic activity for malignant cell growth is unknown. Here, we demonstrate preassembled CBM complexes and constitutive proteolysis of the two known MALT1 substrates in ABC-DLBCL, but not in germinal center B cell-like (GCB) DLBCL. ABC-DLBCL cell treatment with a MALT1 protease inhibitor blocks A20 and BCL10 cleavage, reduces NF-kappaB activity, and decreases the expression of NF-kappaB targets genes. Finally, MALT1 paracaspase inhibition results in death and growth retardation selectively in ABC-DLBCL cells. Thus, our results indicate a growth-promoting role for MALT1 paracaspase activity in ABC-DLBCL and suggest that a pharmacological MALT1 protease inhibition could be a promising approach for lymphoma treatment.

  1. Identification of B-cell epitopes in the capsid protein of avian hepatitis E virus (avian HEV) that are common to human and swine HEVs or unique to avian HEV.

    Science.gov (United States)

    Guo, H; Zhou, E-M; Sun, Z F; Meng, X-J; Halbur, P G

    2006-01-01

    Avian hepatitis E virus (avian HEV) was recently discovered in chickens from the USA that had hepatitis-splenomegaly (HS) syndrome. The complete genomic sequence of avian HEV shares about 50 % nucleotide sequence identity with those of human and swine HEVs. The open reading frame 2 (ORF2) protein of avian HEV has been shown to cross-react with human and swine HEV ORF2 proteins, but the B-cell epitopes in the avian HEV ORF2 protein have not been identified. Nine synthetic peptides from the predicted four antigenic domains of the avian HEV ORF2 protein were synthesized and corresponding rabbit anti-peptide antisera were generated. Using recombinant ORF2 proteins, convalescent pig and chicken antisera, peptides and anti-peptide rabbit sera, at least one epitope at the C terminus of domain II (possibly between aa 477-492) that is unique to avian HEV, one epitope in domain I (aa 389-410) that is common to avian, human and swine HEVs, and one or more epitopes in domain IV (aa 583-600) that are shared between avian and human HEVs were identified. Despite the sequence difference in ORF2 proteins between avian and mammalian HEVs and similar ORF2 sequence between human and swine HEV ORF2 proteins, rabbit antiserum against peptide 6 (aa 389-399) recognized only human HEV ORF2 protein, suggesting complexity of the ORF2 antigenicity. The identification of these B-cell epitopes in avian HEV ORF2 protein may be useful for vaccine design and may lead to future development of immunoassays for differential diagnosis of avian, swine and human HEV infections.

  2. The Influence of Human Interindividual Variability on the Low-Dose Region of Dose-Response Curve Induced by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Primary B Cells.

    Science.gov (United States)

    Dornbos, Peter; Crawford, Robert B; Kaminski, Norbert E; Hession, Sarah L; LaPres, John J

    2016-10-01

    The influence of interindividual variability is not typically assessed in traditional toxicological studies. Given that chemical exposures occur in heterogeneous populations, this knowledge gap has the potential to cause undue harm within the realms of public health and industrial and municipal finances. A recent report from the National Research Council (NRC) suggests that when accounting for interindividual variation in responses, traditionally assumed nonlinear dose-response relationships (DRRs) for noncancer-causing endpoints would better be explained with a linear relationship within the low-dose region. To address this knowledge gap and directly test the NRC's assumption, this study focused on assessing the DRR between 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD) exposure and immune suppression in a cohort of unique human donors. Human B cells were isolated from 51 individual donors and treated with logarithmically increasing concentrations of TCDD (0-30 nM TCDD). Two endpoints sensitive to TCDD were assessed: (1) number of IgM-secreting B cells and (2) quantity of IgM secreted. The results show that TCDD significantly suppressed both the number of IgM-secreting B cells and the quantity of IgM secreted (P < .05). Statistical model comparisons indicate that the low-dose region of the two DRRs is best explained with a nonlinear relationship. Rather than assuming low-dose linearity for all noncancer-causing DRRs, our study suggests the need to consider the specific mode of action of toxicants and pharmaceuticals during risk-management decision making. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Disruption of B-cell homeostatic control mediated by the BLV-Tax oncoprotein: association with the upregulation of Bcl-2 and signaling through NF-kappaB.

    Science.gov (United States)

    Szynal, Maud; Cleuter, Yvette; Beskorwayne, Terry; Bagnis, Claude; Van Lint, Carine; Kerkhofs, Pierre; Burny, Aisene; Martiat, Philippe; Griebel, Philip; Van den Broeke, Anne

    2003-07-17

    Transactivating proteins associated with complex onco-retroviruses including human T-cell leukemia virus-1 (HTLV-1) and bovine leukemia virus (BLV) mediate transformation using poorly understood mechanisms. To gain insight into the processes that govern tumor onset and progression, we have examined the impact of BLV-Tax expression on ovine B-cells, the targets of BLV in experimentally infected sheep, using B-cell clones that are dependent on CD154 and gammac-common cytokines. Tax was capable of mediating progression of B-cells from cytokine dependence to cytokine independence, indicating that the transactivator can over-ride signaling pathways typically controlled by cytokine receptor activation in B-cells. When examined in the presence of both CD154 and interleukin-4, Tax had a clear supportive role on B-cell growth, with an impact on B-cell proliferation, cell cycle phase distribution, and survival. Apoptotic B-cell death mediated by growth factor withdrawal, physical insult, and NF-kappaB inhibition was dramatically reduced in the presence of Tax. Furthermore, the expression of Tax was associated with higher Bcl-2 protein levels, providing rationale for the rescue signals mediated by the transactivator. Finally, Tax expression in B-cells led to a dramatic increase of nuclear RelB/p50 and p50/p50 NF-kappaB dimers, indicating that cellular signaling through NF-kappaB is a major contributory mechanism in the disruption of B-cell homeostasis. Although Tax is involved in aspects of pathogenesis that are unique to complex retroviruses, the viral strategies associated with this transactivating oncoprotein may have wide-ranging effects that are relevant to other B-cell malignancies.

  4. Translational neuroendocrinology: control of human growth.

    Science.gov (United States)

    Clayton, P E; Gill, M S; Tillmann, V; Westwood, M

    2014-06-01

    Human growth is driven by both basic cell processes as well as hormones, in particular the growth hormone (GH)-insulin-like growth factor (IGF)-1 axis. Understanding how these mechanisms are coordinated is not only critical to achieving a normal growth rate, but also to recognising potential new causes of disordered growth and how they might be treated. We have demonstrated in healthy children that height is gained by periods of rapid growth interspersed by periods of very slow growth or even stasis. We have also shown that a lower order organism, Caenorhabditis elegans, grows in a similar manner. By contrast, secretion of GH from somatotrophs occurs on a daily basis in discrete pulses over a 24-h period. We have used the measurement of GH in urine as a surrogate marker of GH secretion to show that there are rhythms of GH output with frequencies of several days. We then assessed which attributes of these GH profiles were related to growth and found that disorderliness in the GH profile (as measured by approximate entropy) was related to better growth rate. This feature was then tested in the dwarf rat using different GH regimens to introduce variation into the administration of daily GH injections. Better long bone growth was associated with week-to-week or even random dose variation compared to the same amount of GH delivered as a standard daily dose. Understanding the control of growth has implications in clinical practice for modelling GH treatment regimens based on physiological principles.

  5. Interleukin-35 induces regulatory B cells that suppress autoimmune disease.

    Science.gov (United States)

    Wang, Ren-Xi; Yu, Cheng-Rong; Dambuza, Ivy M; Mahdi, Rashid M; Dolinska, Monika B; Sergeev, Yuri V; Wingfield, Paul T; Kim, Sung-Hye; Egwuagu, Charles E

    2014-06-01

    Interleukin-10 (IL-10)-producing regulatory B (Breg) cells suppress autoimmune disease, and increased numbers of Breg cells prevent host defense to infection and promote tumor growth and metastasis by converting resting CD4(+) T cells to regulatory T (Treg) cells. The mechanisms mediating the induction and development of Breg cells remain unclear. Here we show that IL-35 induces Breg cells and promotes their conversion to a Breg subset that produces IL-35 as well as IL-10. Treatment of mice with IL-35 conferred protection from experimental autoimmune uveitis (EAU), and mice lacking IL-35 (p35 knockout (KO) mice) or defective in IL-35 signaling (IL-12Rβ2 KO mice) produced less Breg cells endogenously or after treatment with IL-35 and developed severe uveitis. Adoptive transfer of Breg cells induced by recombinant IL-35 suppressed EAU when transferred to mice with established disease, inhibiting pathogenic T helper type 17 (TH17) and TH1 cells while promoting Treg cell expansion. In B cells, IL-35 activates STAT1 and STAT3 through the IL-35 receptor comprising the IL-12Rβ2 and IL-27Rα subunits. As IL-35 also induced the conversion of human B cells into Breg cells, these findings suggest that IL-35 may be used to induce autologous Breg and IL-35(+) Breg cells and treat autoimmune and inflammatory disease.

  6. B cell lymphomas express CX3CR1 a non-B cell lineage adhesion molecule

    DEFF Research Database (Denmark)

    Andreasson, U.; Ek, S.; Merz, H.

    2008-01-01

    To study the differential expression of cell membrane-bound receptors and their potential role in growth and/or survival of the tumor cells, highly purified follicular lymphoma cells were analyzed, using gene expression analysis, and compared to non-malignant B cell populations. Filtering...... the genome for overexpressed genes coding for cell membrane-bound proteins/receptors resulted in a hit list of 27 identified genes. Among these, we have focused on the aberrant over expression of CX3CR1, in different types of B cell lymphoma, as compared to non-malignant B cells. We show that CX3CR1, which...... normally is not expressed on B cells, is expressed both at the mRNA and protein level in several subtypes of lymphoma. CX3CR1 has also shown to be involved in the homing to specific tissues that express the ligand, CX3CL1, in breast and prostate cancer and may thus be involved in dissemination of lymphoma...

  7. TP53 dysfunction in diffuse large B-cell lymphoma.

    Science.gov (United States)

    Lu, Ting-Xun; Young, Ken H; Xu, Wei; Li, Jian-Yong

    2016-01-01

    The aberrations of TP53 gene and dysregulation of the TP53 pathway are important in the pathogenesis of many human cancers, including malignant lymphomas, especially for diffuse large B cell lymphoma (DLBCL). By regulating many downstream target genes or molecules, TP53 governs major defenses against tumor growth and promotes cellular DNA repair, apoptosis, autophagy, cell cycle arrest, signaling, transcription, immune or inflammatory responses and metabolism. Dysfunction of TP53, including microRNA regulations, copy number alterations of TP53 pathway and TP53 itself, dysregulation of TP53 regulators, and somatic mutations by abnormal TP53 function modes, play an important role in lymphoma generation, progression and invasion. The role of TP53 in DLBCL has been widely explored recently. In this review, we summarized recent advances on different mechanisms of TP53 in DLBCL and new therapeutic approaches to overcome TP53 inactivation.

  8. Immune-driven adaptation of hepatitis B virus genotype D involves preferential alteration in B-cell epitopes and replicative attenuation--an insight from human immunodeficiency virus/hepatitis B virus coinfection.

    Science.gov (United States)

    Mondal, R K; Khatun, M; Ghosh, S; Banerjee, P; Datta, S; Sarkar, S; Saha, B; Santra, A; Banerjee, S; Chowdhury, A; Datta, S

    2015-07-01

    An important driving force behind the sequence diversity of hepatitis B virus (HBV) is viral adaptation to host immune responses. To gain an insight into the impact of host immunity on genetic diversification and properties of HBV, we characterized HBV of genotype D from treatment-naive hepatitis B e antigen-positive (EP) and hepatitis B e antigen-negative (EN) patients with chronic hepatitis B (CHB), where HBV is under stronger immune pressure, with that of HBV derived from human immunodeficiency virus (HIV)/HBV-coinfected individuals, where HIV infection has significantly weakened the immune system. Full-length sequence analysis showed that HBV heterogeneity was most extensive in EN-CHB followed by EP-CHB and HIV/HBV coinfection. The relative magnitude of non-synonymous changes within B-cell epitopes was greater than that in T-cell epitopes of HBV open reading frames (ORFs) in both EP-CHB and EN-CHB. Nine amino acid substitutions were identified in B-cell epitopes and one in a T-cell epitope of HBV in EN-CHB, most of which resulted in altered hydrophobicities, as determined using the Kyte and Doolittle method, relative to wild-type residues found in HBV from the HIV-positive group. Additionally, 19 substitutions occurred at significantly higher frequencies in non-epitope regions of HBV ORF-P in EN-CHB than HIV/HBV-coinfected patients. In vitro replication assay demonstrated that the substitutions, particularly in reverse transcriptase and RNaseH domains of ORF-P, resulted in a decline in replication capacity of HBV. Hence, our results indicate that HBV adapts to increasing immune pressure through preferential mutations in B-cell epitopes and by replicative attenuation. The viral epitopes linked to immune response identified in this study bear important implications for future HBV vaccine studies.

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

    Directory of Open Access Journals (Sweden)

    Gitit eShahaf

    2016-03-01

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

  10. [The role of IRA B cells in selected inflammatory processes].

    Science.gov (United States)

    Zasada, Magdalena; Rutkowska-Zapała, Magdalena; Lenart, Marzena; Kwinta, Przemko

    2016-03-16

    The first report about the discovery of new, previously unknown immune cells named IRA B cells (innate response activator B cells) appeared in 2012. So far, their presence has been verified in both mice and humans. However, IRA B cells belong to the family of B lymphocytes and have a number of characteristics unique to this group of cells. IRA B cells are formed from activated B1a lymphocytes after their contact with a pathogen. B1a lymphocytes mainly reside within body cavities. Activated by the pathogen, they move on into secondary lymphoid organs (spleen, lymph nodes) where they differentiate into IRA B cells. IRA B cells are a rich source of granulocyte-macrophage colony stimulating factor (GM-CSF). GM-CSF can stimulate IRA B cells in an autocrine manner for the secretion of intracellular stocks of immunoglobulin M (IgM), which can facilitate pathogens' phagocytosis by neutrophils. GM-CSF also stimulates neutrophils into active phagocytosis. Rapid eradication of the pathogen can prevent the development of an excessive inflammatory response, which can be dangerous for the organism. Until now the involvement of IRA B lymphocytes in the pathogenesis of sepsis and pneumonia has been proven, as well as their role in the progression of atherosclerotic lesions in mice. There is research in progress on the possibility of increasing the number of IRA B cells, for example by intravenous supply of modified immunoglobulins. It is necessary to characterize human IRA B cells and to determine their role in the functioning of the immune system.

  11. IL-10-overexpressing B cells regulate innate and adaptive immune responses.

    Science.gov (United States)

    Stanic, Barbara; van de Veen, Willem; Wirz, Oliver F; Rückert, Beate; Morita, Hideaki; Söllner, Stefan; Akdis, Cezmi A; Akdis, Mübeccel

    2015-03-01

    Distinct human IL-10-producing B-cell subsets with immunoregulatory properties have been described. However, the broader spectrum of their direct cellular targets and suppressive mechanisms has not been extensively studied, particularly in relation to direct and indirect IL-10-mediated functions. The aim of the study was to investigate the effects of IL-10 overexpression on the phenotype and immunoregulatory capacity of B cells. Primary human B cells were transfected with hIL-10, and IL-10-overexpressing B cells were characterized for cytokine and immunoglobulin production by means of specific ELISA and bead-based assays. Antigen presentation, costimulation capacity, and transcription factor signatures were analyzed by means of flow cytometry and quantitative RT-PCR. Effects of IL-10-overexpresing B cells on Toll-like receptor-triggered cytokine release from PBMCs, LPS-triggered maturation of monocyte-derived dendritic cells, and tetanus toxoid-induced PBMC proliferation were assessed in autologous cocultures. IL-10-overexpressing B cells acquired a prominent immunoregulatory profile comprising upregulation of suppressor of cytokine signaling 3 (SOCS3), glycoprotein A repetitions predominant (GARP), the IL-2 receptor α chain (CD25), and programmed cell death 1 ligand 1 (PD-L1). Concurrently, their secretion profile was characterized by a significant reduction in levels of proinflammatory cytokines (TNF-α, IL-8, and macrophage inflammatory protein 1α) and augmented production of anti-inflammatory IL-1 receptor antagonist and vascular endothelial growth factor. Furthermore, IL-10 overexpression was associated with a decrease in costimulatory potential. IL-10-overexpressing B cells secreted less IgE and potently suppressed proinflammatory cytokines in PBMCs, maturation of monocyte-derived dendritic cells (rendering their profile to regulatory phenotype), and antigen-specific proliferation in vitro. Our data demonstrate an essential role for IL-10 in inducing an

  12. IL-4 protects the B-cell lymphoma cell line CH31 from anti-IgM-induced growth arrest and apoptosis:contribution of the PI-3' kinase/AKT pathway

    Institute of Scientific and Technical Information of China (English)

    Gregory B Carey; Elena Semenova; Xiulan Qi; Achsah D Keegan

    2007-01-01

    Interleukin-4(IL-4)promotes lymphocyte survival and protects primary lymphomas from apoptosis.Previous studies reported differential requirements for the signal transducer and activator of transcription 6(STAT6)and IRS2/phosphatidylinositol 3 kinase(PI-3K)signaling pathways in mediating the IL-4-induced protection from Fas-mediated apoptosis.In this study,we characterized IL-4-activated signals that suppress anti-IgM-mediated apoptosis and growth arrest of CH31,a model B-cell lymphoma line.In CH31,anti-IgM treatment leads to the loss of mitochondrial membrane potential,phospho-Akt,phospho-CDK2,and c-myc protein.These losses are followed by massive induction ofp27Kip1 protein expression,cell cycle arrest,and apoptosis.Strikingly,IL-4 treatment prevented or reversed these changes.Furthermore,IL-4 suppressed the activation of caspases 9 and 3,and,in contrast to previous reports,induced the phosphorylation(deactivation)of BAD.IL-4 treatment also induced expression of BclxL,a STAT6-dependent gene.Pharmacologic inhibitors and dominant inhibitory forms of PI-3K andAkt abrogated the anti-apoptotic function of IL-4.These results suggest that the IL-4 receptor activates several signaling pathways,with the Akt pathway playing a major role in suppression of the apoptotic program activated by anti-IgM.

  13. Rationally designed BCL6 inhibitors target activated B cell diffuse large B cell lymphoma.

    Science.gov (United States)

    Cardenas, Mariano G; Yu, Wenbo; Beguelin, Wendy; Teater, Matthew R; Geng, Huimin; Goldstein, Rebecca L; Oswald, Erin; Hatzi, Katerina; Yang, Shao-Ning; Cohen, Joanna; Shaknovich, Rita; Vanommeslaeghe, Kenno; Cheng, Huimin; Liang, Dongdong; Cho, Hyo Je; Abbott, Joshua; Tam, Wayne; Du, Wei; Leonard, John P; Elemento, Olivier; Cerchietti, Leandro; Cierpicki, Tomasz; Xue, Fengtian; MacKerell, Alexander D; Melnick, Ari M

    2016-09-01

    Diffuse large B cell lymphomas (DLBCLs) arise from proliferating B cells transiting different stages of the germinal center reaction. In activated B cell DLBCLs (ABC-DLBCLs), a class of DLBCLs that respond poorly to current therapies, chromosomal translocations and amplification lead to constitutive expression of the B cell lymphoma 6 (BCL6) oncogene. The role of BCL6 in maintaining these lymphomas has not been investigated. Here, we designed small-molecule inhibitors that display higher affinity for BCL6 than its endogenous corepressor ligands to evaluate their therapeutic efficacy for targeting ABC-DLBCL. We used an in silico drug design functional-group mapping approach called SILCS to create a specific BCL6 inhibitor called FX1 that has 10-fold greater potency than endogenous corepressors and binds an essential region of the BCL6 lateral groove. FX1 disrupted formation of the BCL6 repression complex, reactivated BCL6 target genes, and mimicked the phenotype of mice engineered to express BCL6 with corepressor binding site mutations. Low doses of FX1 induced regression of established tumors in mice bearing DLBCL xenografts. Furthermore, FX1 suppressed ABC-DLBCL cells in vitro and in vivo, as well as primary human ABC-DLBCL specimens ex vivo. These findings indicate that ABC-DLBCL is a BCL6-dependent disease that can be targeted by rationally designed inhibitors that exceed the binding affinity of natural BCL6 ligands.

  14. Human Growth Hormone: The Latest Ergogenic Aid?

    Science.gov (United States)

    Cowart, Virginia S.

    1988-01-01

    Believing that synthetic human growth hormone (hGH) will lead to athletic prowess and fortune, some parents and young athletes wish to use the drug to enhance sports performance. Should hGH become widely available, its abuse could present many problems, from potential health risks to the ethics of drug-enhanced athletic performance. (JL)

  15. Culture medium type affects endocytosis of multi-walled carbon nanotubes in BEAS-2B cells and subsequent biological response.

    Science.gov (United States)

    Haniu, Hisao; Saito, Naoto; Matsuda, Yoshikazu; Tsukahara, Tamotsu; Maruyama, Kayo; Usui, Yuki; Aoki, Kaoru; Takanashi, Seiji; Kobayashi, Shinsuke; Nomura, Hiroki; Okamoto, Masanori; Shimizu, Masayuki; Kato, Hiroyuki

    2013-09-01

    We examined the cytotoxicity of multi-walled carbon nanotubes (MWCNTs) and the resulting cytokine secretion in BEAS-2B cells or normal human bronchial epithelial cells (HBEpCs) in two types of culture media (Ham's F12 containing 10% FBS [Ham's F12] and serum-free growth medium [SFGM]). Cellular uptake of MWCNT was observed by fluorescent microscopy and analyzed using flow cytometry. Moreover, we evaluated whether MWCNT uptake was suppressed by 2 types of endocytosis inhibitors. We found that BEAS-2B cells cultured in Ham's F12 and HBEpCs cultured in SFGM showed similar biological responses, but BEAS-2B cells cultured in SFGM did not internalize MWCNTs, and the 50% inhibitory concentration value, i.e., the cytotoxicity, was increased by more than 10-fold. MWCNT uptake was suppressed by a clathrin-mediated endocytosis inhibitor and a caveolae-mediated endocytosis inhibitor in BEAS-2B cells cultured in Ham's F12 and HBEpCs cultured in SFGM. In conclusion, we suggest that BEAS-2B cells cultured in a medium containing serum should be used for the safety evaluation of nanomaterials as a model of normal human bronchial epithelial cells. However, the culture medium composition may affect the proteins that are expressed on the cytoplasmic membrane, which may influence the biological response to MWCNTs.

  16. HIV-associated memory B cell perturbations.

    Science.gov (United States)

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

    2015-05-21

    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.

  17. Intracellular glutathione regulates Andrographolide-induced cytotoxicity on hepatoma Hep3B cells.

    Science.gov (United States)

    Ji, Lili; Shen, Kaikai; Liu, Jun; Chen, Ying; Liu, Tianyu; Wang, Zhengtao

    2009-01-01

    Andrographolide (ANDRO), a diterpenoid lactone isolated from the traditional herbal plant Andrographis paniculata, was reported to induce apoptosis in hepatoma Hep3B cells in our previous study (Ji LL, Liu TY, Liu J, Chen Y, Wang ZT. Andrographolide inhibits human hepatoma-derived Hep3B cells growth through the activation of c-Jun N-terminal kinase. Planta Med 2007; 73: 1397-1401). The present investigation was carried out to observe whether cellular reduced glutathione (GSH) plays important roles in ANDRO-induced apoptosis. ANDRO initially increased intracellular GSH levels which then decreased later, while inhibition of cellular GSH synthesis by L-Buthionine-(S,R)-sulfoximine (BSO) augmented ANDRO-induced cytotoxicity and apoptosis in Hep3B cells. On the other hand, the thiol antioxidant dithiothreitol (DTT) rescued ANDRO-depleted cellular GSH, and abrogated ANDRO-induced cytotoxicity and apoptosis. Furthermore, BSO pretreatment augmented ANDRO-decreased expression of antioxidant protein thioredoxin 1 (Trx1), while DTT reversed this decrease. Further results showed that ANDRO increased the activity of the GSH-related antioxidant enzyme glutathione peroxidase (GPx) and the production of intracellular reactive oxygen species (ROS). Taken together, this study demonstrates that the intracellular redox system plays important roles in regulating the cytotoxicity of ANDRO on hepatoma Hep3B cells.

  18. Prevention of B cell antigen receptor-induced apoptosis by ligation of CD40 occurs downstream of cell cycle regulation

    NARCIS (Netherlands)

    Mackus, WJM; Lens, SMA; Medema, RH; Kwakkenbos, MJ; van Oers, MHJ; van Lier, RAW; Eldering, E

    Cross-linking of the B cell antigen receptor (BCR) on germinal center B cells can induce growth arrest and apoptosis, thereby eliminating potentially autoreactive B cells. Using the Burkitt lymphoma cell line Ramos as a model, we studied the commitment to apoptosis following growth arrest, as well

  19. Human epidermal growth factor and the proliferation of human fibroblasts.

    Science.gov (United States)

    Carpenter, G; Cohen, S

    1976-06-01

    The effect of human epidermal growth factor (hEGF), a 5,400 molecular weight polypeptide isolated from human urine, on the growth of human foreskin fibroblasts (HF cells) was studied by measuring cell numbers and the incorporation of labeled thymidine. The addition of hEGF to HF cells growing in a medium containing 10% calf serum resulted in a 4-fold increase in the final density. The presence of hEGF also promoted the growth of HF cells in media containing either 1% calf serum or 10% gamma globulin-free serum. The addition of hEGF to quiescent confluent monolayers of HF cells, maintained in a medium with 1% calf serum for 48 hours, resulted in a 10- to 20-fold increase in the amount of 3H-thymidine incorporation after 20-24 hours. The stimulation of thymidine incorporation was maximal at an hEGF concentration of 2 ng/ml, was dependent on the presence of serum, and was enhanced by the addition of ascorbic acid. In confluent cultures of HF cells, subject to density dependent inhibition of growth, hEGF was able to stimulate DNA synthesis more effectively than fresh calf serum. Human EGF stimulated DNA synthesis in quiescent cultures, however, regardless of cell density. The addition of rabbit anti-hEGF inhibited all effects of this growth factor on HF cells.

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

    Science.gov (United States)

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

    2017-02-12

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

  1. The Epstein-Barr virus-binding site on CD21 is involved in CD23 binding and interleukin-4-induced IgE and IgG4 production by human B cells.

    Science.gov (United States)

    Henchoz-Lecoanet, S; Jeannin, P; Aubry, J P; Graber, P; Bradshaw, C G; Pochon, S; Bonnefoy, J Y

    1996-01-01

    Human CD21 has previously been described as a receptor for the C3d,g and iC3b proteins of complement, as a receptor for the gp350/220 envelope glycoprotein of the Epstein-Barr virus (EBV) and also as a receptor for inerferon-alpha (IFN-alpha). Structurally, CD21 consists of 15 to 16 short consensus repeats (SCR) of 60 to 75 amino acids followed by a transmembrane domain and an intracytoplasmic region. We reported that CD23, a low-affinity receptor for IgE (Fc epsilon R2), is a new functional ligand for CD21. We recently found that the sites of interaction of CD23 on CD21 are on SCR 5 to 8 and 1-2. The first site is a lectin-sugar type of interaction and the second site is a protein-protein interaction. We report here that amongst the other ligands for CD21 (EBV, C3d,g and IFN-alpha), only EBV is able to inhibit the binding of CD23 to CD21. Furthermore, even a peptide from gp350/220 of EBV known to bind to CD21 is able to decrease CD23 binding to CD21. Since CD23/CD21 pairing is important in the control of IgE production, we tested the effect of the EBV-derived peptide on immunoglobulin production from peripheral blood mononuclear cells and purified tonsillar B cells. Interestingly, the EBV-peptide inhibited IgE and IgG4 production induced by interleukin-4, in a dose-dependent manner. The same results were obtained using either peripheral blood mononuclear cells or purified tonsillar B cells. Another CD21 ligand, C3, did not affect binding of CD23 to CD21 nor the production of IgE and IgG4. This study indicates that blocking CD23 binding to CD21 SCR 2 on human B cells selectively modulates immunoglobulin production. PMID:8707347

  2. B-type suppression: a role played by "regulatory B cells" or "regulatory plasma cells"?

    Science.gov (United States)

    Ries, Stefanie; Hilgenberg, Ellen; Lampropoulou, Vicky; Shen, Ping; Dang, Van Duc; Wilantri, Siska; Sakwa, Imme; Fillatreau, Simon

    2014-05-01

    B-cell depletion can improve disease in some patients with rheumatoid arthritis or multiple sclerosis, indicating the pathogenic contribution of B cells to autoimmunity. However, studies in mice have demonstrated that B cells have immunosuppressive functions as well, with IL-10 being a critical mediator of B-cell-mediated suppression. IL-10-secreting B cells have been shown to promote disease remission in some mouse models of autoimmune disorders. Human B cells also produce IL-10, and evidence is accumulating that human IL-10-producing B cells might inhibit immunity. There is considerable interest in identifying the phenotype of B cells providing IL-10 in a suppressive manner, which would facilitate the analysis of the molecular mechanisms controlling this B-cell property. Here, we review current knowledge on the B-cell subpopulations found to provide suppressive functions in mice, considering both the pathological context in which they were identified and the signals that control their induction. We discuss the phenotype of B cells that have IL-10-dependent regulatory activities in mice, which leads us to propose that antibody-secreting cells are, in some cases at least, the major source of B-cell-derived regulatory IL-10 in vivo. Anti-inflammatory cytokine production by antibody-secreting cells offers a novel mechanism for the coordination of innate and humoral immune responses.

  3. Long non-coding RNA profiling of human lymphoid progenitor cells reveals transcriptional divergence of B cell and T cell lineages.

    Science.gov (United States)

    Casero, David; Sandoval, Salemiz; Seet, Christopher S; Scholes, Jessica; Zhu, Yuhua; Ha, Vi Luan; Luong, Annie; Parekh, Chintan; Crooks, Gay M

    2015-12-01

    To elucidate the transcriptional 'landscape' that regulates human lymphoid commitment during postnatal life, we used RNA sequencing to assemble the long non-coding transcriptome across human bone marrow and thymic progenitor cells spanning the earliest stages of B lymphoid and T lymphoid specification. Over 3,000 genes encoding previously unknown long non-coding RNAs (lncRNAs) were revealed through the analysis of these rare populations. Lymphoid commitment was characterized by lncRNA expression patterns that were highly stage specific and were more lineage specific than those of protein-coding genes. Protein-coding genes co-expressed with neighboring lncRNA genes showed enrichment for ontologies related to lymphoid differentiation. The exquisite cell-type specificity of global lncRNA expression patterns independently revealed new developmental relationships among the earliest progenitor cells in the human bone marrow and thymus.

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

    Directory of Open Access Journals (Sweden)

    Daniela Frasca

    2017-08-01

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

  5. Multiple Curricula for B Cell Developmental Programming.

    Science.gov (United States)

    Rothenberg, Ellen V

    2016-09-20

    B-1 B cells differ from conventional B-2 B cells functionally, but how these differences relate to the ontogeny of these lineages has been unclear. Two recent Immunity articles, Kristiansen et al. (2016) and Montecino-Rodriguez et al. (2016), now provide insight into the origins of B-1 and B-2 B cells, revealing a multi-layered developmental program and successive waves of B cell precursors.

  6. Ikaros in B cell development and function

    Institute of Scientific and Technical Information of China (English)

    MacLean; Sellars; Philippe; Kastner; Susan; Chan

    2011-01-01

    The zinc finger transcription factor,Ikaros,is a central regulator of hematopoiesis.It is required for the development of the earliest B cell progenitors and at later stages for VDJ recombination and B cell receptor expression.Mature B cells rely on Ikaros to set the activation threshold for various stimuli,and to choose the correct antibody isotype during class switch recombination.Thus,Ikaros contributes to nearly every level of B cell differentiation and function.

  7. Immunoglobulin V(H) gene sequence analysis of spontaneous murine immunoglobulin secreting B-cell tumours with clinical features of human disease

    NARCIS (Netherlands)

    Zhu, D.; Arkel, C. van; King, C.A.; Meirvenne, S. van; Greef, C. de; Thielemans, K.; Radl, J.; Stevenson, F.K.

    1998-01-01

    The 5T series of multiple myelomas (MM) and Waldenstrsom's macroglobulinaemia-like lymphomas (WM), which developed spontaneously in ageing mice of the C57BL/KaLwRij strain, shows clinical and biological features that closely resemble their corresponding human diseases. In order to compare the patter

  8. B cell-intrinsic signaling through IL-21 receptor and STAT3 is required for establishing long-lived antibody responses in humans

    NARCIS (Netherlands)

    Avery, Danielle T.; Deenick, Elissa K.; Ma, Cindy S.; Suryani, Santi; Simpson, Nicholas; Chew, Gary Y.; Chan, Tyani D.; Palendira, Umamainthan; Bustamante, Jacinta; Boisson-Dupuis, Stephanie; Choo, Sharon; Bleasel, Karl E.; Peake, Jane; King, Cecile; French, Martyn A.; Engelhard, Dan; Al-Hajjar, Sami; Al-Muhsen, Saleh; Magdorf, Klaus; Roesler, Joachim; Arkwright, Peter D.; Hissaria, Pravin; Riminton, D. Sean; Wong, Melanie; Brink, Robert; Fulcher, David A.; Casanova, Jean-Laurent; Cook, Matthew C.; Tangye, Stuart G.

    2010-01-01

    Engagement of cytokine receptors by specific ligands activate Janus kinase-signal transducer and activator of transcription (STAT) signaling pathways. The exact roles of STATs in human lymphocyte behavior remain incompletely defined. Interleukin (IL)-21 activates STAT1 and STAT3 and has emerged as a

  9. NKT Cell Responses to B Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Junxin Li

    2014-04-01

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

  10. In vitro induction and detection of human B cells producing HLA antibodies%体外诱导和检测人类B细胞产生抗HLA抗体的研究

    Institute of Scientific and Technical Information of China (English)

    廖爱华; 刘丽平; 黄伟; 陈栋; 王燕; 张玲

    2009-01-01

    Objective To induce and detect human B cells producing HLA antibodies in vitro and by an ELISPOT assay. Methods Human peripheral blood mononuclear cells (PBMC) from 7 healthy vol-unteers were isolated by density gradient centrifugation, and cultured with the stimulation of PWM alone or PWM + SAC for 5 d. The lg levels in culture supernatants and the number of Ig producing B cells were de-termined by ELISA and ELISPOT assay, respectively. The optimal stimulation protocol for PBMC to produce optimal Ig in vitro was anticipated to be obtained. Using the optimal pre-cuhure and ELISPOT conditions, PBMC from 9 alloimmunized subjects were analyzed for the presence of B cells secreting HLA antibodies. Results There was a tendency towards more viable cells following the activation with PWM and SAC vs PWM alone in a 5-day culture (P =0. 052). The IgG levels in the supernatants were found to be comparable for the two culture conditions whereas the lgM levels were increased ( P = 0.03 ) in the presence of the com-bination of PWM and SAC. In 6 subjects a specific signal was obtained with our ELISPOT assay. The presence of HLA antibodies in the respective pre-cuhure supernatants supported the specificity. Conclusion The activation of PBMC with the combination of PWM and SAC, and the application of HLA-specifie ELIS-POT assay can succeed in the induction and detection of human B cells producing HLA antibodies.%目的 体外诱导和采用酶联免疫斑点法(ELISPOT)检测人类B细胞产生的抗HLA抗体.方法 对7名健康志愿者采用密度梯度离心法分离外周血单个核细胞(PBMC)并体外培养5 d,以B细胞多克隆刺激原美洲商陆丝裂原(PWM)、葡萄球菌A蛋白菌体(SAC)体外刺激PBMC,采用EHSA和ELISPOT方法分别测定培养上清中Ig浓度和抗体分泌B细胞数,探索体外诱导PBMC产生Ig的适宜方法.采用该刺激方法和HLA特异的ELISPOT法,诱导和检测9例拟行肾移植预致敏对象PBMC产生的抗HLA抗体.结果

  11. Polysaccharide-specific memory B cells generated by conjugate vaccines in humans conform to the CD27+IgG+ isotype-switched memory B Cell phenotype and require contact-dependent signals from bystander T cells activated by bacterial proteins to differentiate into plasma cells.

    Science.gov (United States)

    Clarke, Edward T; Williams, Neil A; Findlow, Jamie; Borrow, Ray; Heyderman, Robert S; Finn, Adam

    2013-12-15

    The polysaccharides (PS) surrounding encapsulated bacteria are generally unable to activate T cells and hence do not induce B cell memory (BMEM). PS conjugate vaccines recruit CD4(+) T cells via a carrier protein, such as tetanus toxoid (TT), resulting in the induction of PS-specific BMEM. However, the requirement for T cells in the subsequent activation of the BMEM at the time of bacterial encounter is poorly understood, despite having critical implications for protection. We demonstrate that the PS-specific BMEM induced in humans by a meningococcal serogroup C PS (Men C)-TT conjugate vaccine conform to the isotype-switched (IgG(+)CD27(+)) rather than the IgM memory (IgM(+)CD27(+)) phenotype. Both Men C and TT-specific BMEM require CD4(+) T cells to differentiate into plasma cells. However, noncognate bystander T cells provide such signals to PS-specific BMEM with comparable effect to the cognate T cells available to TT-specific BMEM. The interaction between the two populations is contact-dependent and is mediated in part through CD40. Meningococci drive the differentiation of the Men C-specific BMEM through the activation of bystander T cells by bacterial proteins, although these signals are enhanced by T cell-independent innate signals. An effect of the TT-specific T cells activated by the vaccine on unrelated BMEM in vivo is also demonstrated. These data highlight that any protection conferred by PS-specific BMEM at the time of bacterial encounter will depend on the effectiveness with which bacterial proteins are able to activate bystander T cells. Priming for T cell memory against bacterial proteins through their inclusion in vaccine preparations must continue to be pursued.

  12. Defective IL-4/Stat6 Signaling Correlates with Increased Apoptosis of Human EBV-lymphoblastoid B Cells and Mouse Spleen Cells

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1Introduction IL-4-induced Stat6 (Signal transducer and activator of transcription 6) pathway is active in many cell types including cancer cells and immune cells which plays an important role in cell differenciation/growth and resistance to apoptosis~([1]). IL-4/Stat6 signaling up-regulates cell surface moleculi suchas CD23, MHC class II and IL-4Rα, and down-regulates proinflammatory cytokines,i.e, IL-12 and TNFα.Stat6 can be spontaneously activated in Hodgkin's lymphoma and other tumors, suggesting its...

  13. Mangiferin inhibition of proliferation and induction of apoptosis in human prostate cancer cells is correlated with downregulation of B-cell lymphoma-2 and upregulation of microRNA-182.

    Science.gov (United States)

    Li, Minglin; Ma, Huili; Yang, Lixin; Li, Peng

    2016-01-01

    Mangiferin, a flavonoid extracted from the mango tree, possesses anti-inflammatory, antibacterial, anti-herpes simplex and antitumor activity, and is able to affect immune function. The present study investigated the anticancer effects of mangiferin treatment on PC3 human prostate cancer cells, and the potential underlying mechanisms. In the present study, an MTT assay was used to analyze the proliferation of PC3 cells. Subsequently, flow cytometry and colorimetric assay kits were utilized to measure the PC3 cell apoptotic rate. The expression levels of B-cell lymphoma-2 (Bcl-2) and microRNA-182 (miR-182) were detected using western blot analysis and quantitative reverse transcription-polymerase chain reaction, respectively. Finally, miR-182 and anti-miR-182 were transfected into PC3 cells, which were used to investigate the effects of mangiferin. Mangiferin treatment reduced the proliferation of PC3 human prostate cancer cells in a concentration- and time-dependent manner. In addition, mangiferin was able to promote apoptosis and induce the caspase-3 activity of PC3 human prostate cancer cells. Mangiferin treatment was also able to significantly reduce Bcl-2 expression levels and enhance miR-182 expression in PC3 cells. Finally, it was observed that mangiferin inhibited proliferation and induced apoptosis in PC3 human prostate cancer cells, and this effect was correlated with downregulation of Bcl-2 and upregulation of miR-182.

  14. Broadly cross-reactive antibodies dominate the human B cell response against 2009 pandemic H1N1 influenza virus infection

    OpenAIRE

    2011-01-01

    The 2009 pandemic H1N1 influenza pandemic demonstrated the global health threat of reassortant influenza strains. Herein, we report a detailed analysis of plasmablast and monoclonal antibody responses induced by pandemic H1N1 infection in humans. Unlike antibodies elicited by annual influenza vaccinations, most neutralizing antibodies induced by pandemic H1N1 infection were broadly cross-reactive against epitopes in the hemagglutinin (HA) stalk and head domain of multiple influenza strains. T...

  15. Mapping of immunodominant B-cell epitopes and the human serum albumin-binding site in natural hepatitis B virus surface antigen of defined genosubtype.

    Science.gov (United States)

    Sobotta, D; Sominskaya, I; Jansons, J; Meisel, H; Schmitt, S; Heermann, K H; Kaluza, G; Pumpens, P; Gerlich, W H

    2000-02-01

    Twelve MAbs were generated by immunization of BALB/c mice with plasma-derived hepatitis B virus surface spherical antigen particles subtype ayw2 (HBsAg/ayw2 genotype D). Their epitopes were mapped by analysis of reactivity with plasma-derived HBsAg/ayw2 and HBsAg/adw2 (genotype A) in enzyme immunoassays and blots. Mapping was supported by nested sets of truncated preS2 proteins and preS2 peptides. Five antibodies were S domain-specific, seven were preS2-specific and 11 had a preference for genotype D. According to our data, group I of the three known epitope groups of preS2 has to be divided into IA and IB. Three preS2-specific MAbs forming the new group IA reacted with genotype D residues 3-15 which have not yet been described as an epitope region. IA antibodies strongly inhibited the binding of polymerized human serum albumin. Two antibodies (group II) reacted with the glycosylated N-terminal region of preS2 in plasma-derived HBsAg, but not with a preparation from transfected murine cells. One group III antibody was subtype-specific and reacted with the highly variable preS2 sequence 38-48. Only one antibody (group IB) mapped to the region (old group I) which was believed to be immunodominant and genotype-independent. Geno(sub)type-specific epitopes of preS2 are obviously the immunodominant components of natural HBsAg in BALB/c mice, but these epitopes may be masked by serum albumins in humans. The data may explain why it is difficult to detect anti-preS2 antibodies in human recipients of preS2-containing vaccines, in spite of the preS2 immunodominance in mice.

  16. Human embryonic growth trajectories and associations with fetal growth and birthweight

    NARCIS (Netherlands)

    van Uitert, Evelyne M.; Exalto, Niek; Burton, Graham J.; Willemsen, Sten P.; Koning, Anton H. J.; Eilers, Paul H. C.; Laven, Joop S. E.; Steegers, Eric A. P.; Steegers-Theunissen, Regine P. M.

    2013-01-01

    How do human embryonic growth trajectories evolve in the first trimester, and is first-trimester embryonic growth associated with fetal growth and birthweight (BW)? Human embryonic growth rates increase between 9 and 10 weeks of gestation and are associated with mid-pregnancy fetal growth and BW. Fe

  17. HCV Infection and B-Cell Lymphomagenesis

    Directory of Open Access Journals (Sweden)

    Masahiko Ito

    2011-01-01

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

  18. B Cell Autonomous TLR Signaling and Autoimmunity

    Science.gov (United States)

    Meyer-Bahlburg, Almut; Rawlings, David J

    2009-01-01

    B cells play a central role in the pathogenesis of multiple autoimmune diseases and the recognition of importance of B cells in these disorders has grown dramatically in association with the remarkable success of B-cell depletion as a treatment for autoimmunity. The precise mechanisms that promote alterations in B cell tolerance remain incompletely defined. There is increasing evidence, however, that TLRs play a major role in these events. Stimulation of B cells via the TLR pathway not only leads to an increase in antibody production but also promotes additional changes including cytokine production and upregulation of activation markers increasing the effectiveness of B cells as APCs. Understanding the role of TLRs in systemic autoimmunity will not only provide insight into the disease pathogenesis but may also lead to the development of novel therapies. This article gives an overview of TLR signaling in B cells and the possible involvement of such signals in autoimmune diseases. PMID:18295736

  19. Memory B cells in mouse models.

    Science.gov (United States)

    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.

  20. Antigen-specific memory B cell development.

    Science.gov (United States)

    McHeyzer-Williams, Louise J; McHeyzer-Williams, Michael G

    2005-01-01

    Helper T (Th) cell-regulated B cell immunity progresses in an ordered cascade of cellular development that culminates in the production of antigen-specific memory B cells. The recognition of peptide MHC class II complexes on activated antigen-presenting cells is critical for effective Th cell selection, clonal expansion, and effector Th cell function development (Phase I). Cognate effector Th cell-B cell interactions then promote the development of either short-lived plasma cells (PCs) or germinal centers (GCs) (Phase II). These GCs expand, diversify, and select high-affinity variants of antigen-specific B cells for entry into the long-lived memory B cell compartment (Phase III). Upon antigen rechallenge, memory B cells rapidly expand and differentiate into PCs under the cognate control of memory Th cells (Phase IV). We review the cellular and molecular regulators of this dynamic process with emphasis on the multiple memory B cell fates that develop in vivo.

  1. Genesis of lymphoid tissue and development of IgM-positive B cells in human fetal ileum%人胎回肠淋巴组织发生及IgM阳性B细胞的发育

    Institute of Scientific and Technical Information of China (English)

    胡蓉; 苏敏; 黄悦; 李红; 姜俸蓉; 许庭良

    2011-01-01

    目的 探讨人胎回肠淋巴组织的发生及IgM阳性B细胞在人胎回肠的分布、定位及发育. 方法 收集2003年1月至2005年12月贵阳市各医院妇产科因流产等终止妊娠的9~28周人胎回肠标本30例,男12例、女18例.采用HE染色观察人胎回肠淋巴组织发生,SABC法染色显示IgM阳性B细胞,并用BioMias29图像分析软件对免疫反应阳性细胞进行计数,有关数据作统计学分析.结果 胎龄9周时少量淋巴细胞分布于回肠上皮外的间充质内,其中部分细胞表达膜表面IgM.胎龄17周时固有层内淋巴组织局部聚集形成孤立淋巴小结,小结内含有较多IgM阳性B细胞.自24周起,人胎回肠可见典型的集合淋巴小结.IgM阳性B细胞主要分布于淋巴小结,少量弥散分布在固有层结缔组织或绒毛上皮内.细胞计数显示9~12周人胎回肠IgM阳性B细胞数量为(12.80±5.72)个,随胎龄增加至25~28周人胎回肠IgM阳性B细胞达(201.30±36.35)个,各胎龄组间比较差异显著(P<0.05).结论 24周人胎回肠壁淋巴组织结构基本发育成熟;人胎回肠具有潜在的IgM合成和释放能力,对胎儿肠道免疫功能的建立和健全起着重要作用.%Objective To study genesis of lymphoid tissue and distribution, localization and develop ment of lgM-positive B cells in human fetal ileum. Methods Human fetus specimens from terminated preg nancies, 12 males and 18 females with gestational ages of 9 -28 weeks, were collected from hospitals in Guiyang, China, between Jan. 2003 and Dec. 2005. All pregnant women were informed of the purpose of this study and the protocol was approved by the Ethics Committee of Guiyang Medical College. HE staining was adopted to observe the genesis of lymphoid tissue in human fetal ileum. IgM-positive B cells were detected by immunohistochemical SABC staining, and counted by BioMias 29 image analysis software. Relevant data were statistically analyzed. Results In the ilea of 9-week fetus

  2. B-cell epitopes in NTS-DBL1α of PfEMP1 recognized by human antibodies in Rosetting Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Letusa Albrecht

    Full Text Available Plasmodium falciparum is the most lethal of the human malaria parasites. The virulence is associated with the capacity of the infected red blood cell (iRBC to sequester inside the deep microvasculature where it may cause obstruction of the blood-flow when binding is excessive. Rosetting, the adherence of the iRBC to uninfected erythrocytes, has been found associated with severe malaria and found to be mediated by the NTS-DBL1α-domain of Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1. Here we show that the reactivity of plasma of Cameroonian children with the surface of the FCR3S1.2-iRBC correlated with the capacity to disrupt rosettes and with the antibody reactivity with a recombinant PfEMP1 (NTS-DBL1α of IT4var60 expressed by parasite FCR3S1.2. The plasma-reactivity in a microarray, consisting of 96 overlapping 15-mer long peptides covering the NTS-DBL1α domain from IT4var60 sequence, was compared with their capacity to disrupt rosettes and we identified five peptides where the reactivity were correlated. Three of the peptides were localized in subdomain-1 and 2. The other two peptide-sequences were localized in the NTS-domain and in subdomain-3. Further, principal component analysis and orthogonal partial least square analysis generated a model that supported these findings. In conclusion, human antibody reactivity with short linear-peptides of NTS-DBL1α of PfEMP1 suggests subdomains 1 and 2 to hold anti-rosetting epitopes recognized by anti-rosetting antibodies. The data suggest rosetting to be mediated by the variable areas of PfEMP1 but also to involve structurally relatively conserved areas of the molecule that may induce biologically active antibodies.

  3. B-cell epitopes in NTS-DBL1α of PfEMP1 recognized by human antibodies in Rosetting Plasmodium falciparum.

    Science.gov (United States)

    Albrecht, Letusa; Angeletti, Davide; Moll, Kirsten; Blomqvist, Karin; Valentini, Davide; D'Alexandri, Fabio Luiz; Maurer, Markus; Wahlgren, Mats

    2014-01-01

    Plasmodium falciparum is the most lethal of the human malaria parasites. The virulence is associated with the capacity of the infected red blood cell (iRBC) to sequester inside the deep microvasculature where it may cause obstruction of the blood-flow when binding is excessive. Rosetting, the adherence of the iRBC to uninfected erythrocytes, has been found associated with severe malaria and found to be mediated by the NTS-DBL1α-domain of Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1). Here we show that the reactivity of plasma of Cameroonian children with the surface of the FCR3S1.2-iRBC correlated with the capacity to disrupt rosettes and with the antibody reactivity with a recombinant PfEMP1 (NTS-DBL1α of IT4var60) expressed by parasite FCR3S1.2. The plasma-reactivity in a microarray, consisting of 96 overlapping 15-mer long peptides covering the NTS-DBL1α domain from IT4var60 sequence, was compared with their capacity to disrupt rosettes and we identified five peptides where the reactivity were correlated. Three of the peptides were localized in subdomain-1 and 2. The other two peptide-sequences were localized in the NTS-domain and in subdomain-3. Further, principal component analysis and orthogonal partial least square analysis generated a model that supported these findings. In conclusion, human antibody reactivity with short linear-peptides of NTS-DBL1α of PfEMP1 suggests subdomains 1 and 2 to hold anti-rosetting epitopes recognized by anti-rosetting antibodies. The data suggest rosetting to be mediated by the variable areas of PfEMP1 but also to involve structurally relatively conserved areas of the molecule that may induce biologically active antibodies.

  4. Epidermal growth factor (urogastrone) in human tissues.

    Science.gov (United States)

    Hirata, Y; Orth, D N

    1979-04-01

    Human epidermal growth factor (hEGF), which stimulates the growth of a variety of tissues, was first isolated from mouse submandibular glands, but is also excreted in large amounts (about 50 micrograms/day) in human urine and is probably identical to human beta-urogastrone (hUG), a potent inhibitor of stimulated gastric acid secretion. However, the primary tissue source of hEGF/hUG is as yet unknown. The hEGF/hUG in homogenates of human salivary glands and a wide variety of other endocrine and nonendocrine tissues was extracted by Amberlite CG-50 cation exchange chromatography and immune affinity chromatography using the immunoglobulin fraction of rabbit anti-hEGF serum covalently bound to agarose. The extracts were subjected to homologous hEGF RIA. Immunoreactive hEGF was found in extracts of adult submandibular gland, thyroid gland, duodenum, jejunum, and kidney, but not in several fetal tissues. The tissue immunoreactive hEGF was similar to standard hEGF in terms of immunoreactivity and elution from Sephadex G-50 Fine resin, but its concentrations were very low (1.3-5.5 ng/g wet tissue). Thus, it is not certain that these tissues represent the only source of the large amounts of hEGF/hUG that appear to be filtered by the kidneys each day.

  5. Information for People Treated with Human Growth Hormone (Summary)

    Science.gov (United States)

    ... NHPP): Information for People Treated with Pituitary Human Growth Hormone (Summary) How did Creutzfeldt-Jakob disease (CJD) occur in people treated with pituitary human growth hormone (hGH)? From 1963 to 1985, the National Hormone ...

  6. Reconstituted B cell receptor signaling reveals carbohydrate-dependent mode of activation

    OpenAIRE

    2016-01-01

    Activation of immune cells (but not B cells) with lectins is widely known. We used the structurally defined interaction between influenza hemagglutinin (HA) and its cell surface receptor sialic acid (SA) to identify a B cell receptor (BCR) activation modality that proceeded through non-cognate interactions with antigen. Using a new approach to reconstitute antigen-receptor interactions in a human reporter B cell line, we found that sequence-defined BCRs from the human germline repertoire coul...

  7. Bendamustine increases interleukin-10 secretion from B cells via p38 MAP kinase activation.

    Science.gov (United States)

    Lu, Le; Yoshimoto, Keiko; Morita, Atsuho; Kameda, Hideto; Takeuchi, Tsutomu

    2016-10-01

    We investigated the effects of bendamustine on B cell functions and explored potential clinical applications of the drugs to autoimmune diseases. Proliferation of Ramos cells, a human B cell line, was significantly inhibited by 25-100μM of bendamustine in a dose-dependent manner. Concordantly, IgM secretion from Ramos cells was significantly inhibited at these concentrations by up to 70%. Interestingly, however, the production and secretion of interleukin-10 (IL-10) were dramatically (at least >10-fold) increased by bendamustine at growth inhibitory concentrations. Exploration of the molecular mechanism of IL-10 production revealed that bendamustine enhanced the phosphorylation of p38 MAP kinase. Further, Sp1 was identified as a downstream transcription factor, and the inhibition of p38 MAP kinase and Sp1 with their inhibitors led to the abrogation of bendamustine-induced IL-10 production and the DNA binding of Sp1. Importantly, when PBMC from healthy donors were cultured with bendamustine at the concentration of 30μM, under the stimulation with an anti-IgM antibody, an anti-CD40 antibody, recombinant human IL-21 (rhIL-21) and recombinant human soluble BAFF (rhsBAFF), IL-10 production by B cells (CD20+CD4-CD8-CD14-) among peripheral blood mononuclear cell (PBMC) was significantly enhanced by adding bendamustine. These results collectively suggest that the p38 MAP kinase-Sp1 pathway plays a crucial role in bendamustine-induced IL-10 production by B cells. Our findings suggest a novel therapeutic possibility for autoimmune diseases through the upregulation of IL-10 which has an anti-inflammatory effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Quality-adjusted Human Capital and Productivity Growth

    OpenAIRE

    Md. Rabiul Islam

    2010-01-01

    Both the quality and quantity of human capital are important for growth. Although the quality aspects of human capital may have greater potential in explaining growth, given that the quantity effects of human capital have been found to be ambiguous, they have long been ignored in empirical growth literature. This paper empirically tests the joint effects of both the quantity and quality of human capital in stimulating productivity growth for a panel of 89 countries over the period 1970-2007. ...

  9. Inferring processes underlying B-cell repertoire diversity

    Science.gov (United States)

    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

  10. Analysis of memory-like natural killer cells in human cytomegalovirus-infected children undergoing αβ+T and B cell-depleted hematopoietic stem cell transplantation for hematological malignancies.

    Science.gov (United States)

    Muccio, Letizia; Bertaina, Alice; Falco, Michela; Pende, Daniela; Meazza, Raffaella; Lopez-Botet, Miguel; Moretta, Lorenzo; Locatelli, Franco; Moretta, Alessandro; Della Chiesa, Mariella

    2016-03-01

    We analyzed the impact of human cytomegalovirus infection on the development of natural killer cells in 27 pediatric patients affected by hematological malignancies, who had received a HLA-haploidentical hematopoietic stem cell transplantation, depleted of both α/β+ T cells and B cells. In line with previous studies in adult recipients of umbilical cord blood transplantation, we found that human cytomegalovirus reactivation accelerated the emergence of mature natural killer cells. Thus, most children displayed a progressive expansion of a memory-like natural killer cell subset expressing NKG2C, a putative receptor for human cytomegalovirus, and CD57, a marker of terminal natural killer cell differentiation. NKG2C(+)CD57(+) natural killer cells were detectable by month 3 following hematopoietic stem cell transplantation and expanded until at least month 12. These cells were characterized by high killer Ig-like receptors (KIRs) and leukocyte inhibitory receptor 1 (LIR-1) and low Siglec-7, NKG2A and Interleukin-18Rα expression, killed tumor targets and responded to cells expressing HLA-E (a NKG2C ligand). In addition, they were poor Interferon-γ producers in response to Interleukin-12 and Interleukin-18. The impaired response to these cytokines, together with their highly differentiated profile, may reflect their skewing toward an adaptive condition specialized in controlling human cytomegalovirus. In conclusion, in pediatric patients receiving a type of allograft different from umbilical cord blood transplantation, human cytomegalovirus also induced memory-like natural killer cells, possibly contributing to controlling infections and reinforcing anti-leukemia effects. Copyright© Ferrata Storti Foundation.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    Human and mouse chronic lymphocytic leukemia (CLL) develop from CD5+ B cells that in mice and macaques are known to define the distinct B1a B cell lineage. B1a cells are characterized by lack of germinal center development and the B1a cell population is increased in mice with reduced germinal...... center formation. As a major mediator of follicular B cell migration, the G protein-coupled receptor (GPCR) Epstein Barr virus-induced gene 2 (EBI2 or GPR183) directs B cell migration in the lymphoid follicles in response to its endogenous ligands, oxysterols. Thus, upregulation of EBI2 drives the B...... cells towards the extrafollicular area, whereas downregulation is essential for germinal center formation. We therefore speculated whether increased expression of EBI2 would lead to an expanded B1 cell subset and, ultimately, progression to chronic lymphocytic leukemia. Here we demonstrate that B cell...

  12. Cytotoxic, apoptotic, and sensitization properties of ent-kaurane-type diterpenoids from Croton tonkinensis Gagnep on human liver cancer HepG2 and Hep3b cell lines.

    Science.gov (United States)

    Pham, Minh Quan; Iscache, Anne Laure; Pham, Quoc Long; Gairin, Jean Edouard

    2016-04-01

    Human hepatocellular carcinoma (HCC) is the most common type of liver cancer, the second most common cause of death from cancer worldwide. A very poor prognosis and a lack of effective treatments make liver cancer a major public health problem, notably in less developed regions, particularly in eastern Asia. This fully justifies the search of new molecules and therapeutic strategies against HCC. Ent-kaurane diterpenoids are natural compounds displaying a broad spectrum of potential therapeutic effects including anticancer activity. In this study, we analyzed the pharmacological properties of a family of ent-kaurane diterpenoids from Croton tonkinensis Gagnep in human HepG2 and Hep3b cell lines, used as cellular reference models for in vitro evaluation of new molecules active on HCC. A structure-related cytotoxicity was observed against both HCC cell lines, enlighting the role of the 16-en-15-one skeleton of ent-kaurane diterpenoids. Cytotoxicity was closely correlated to apoptosis, evidenced by concentration-dependent subG1 cell accumulation, and increased annexin V expression. In addition, subtoxic concentration of ent-kaurane diterpenoid dramatically enhanced the sensitivity of HCC cells to doxorubicin. All together, our data bring strong support to the potential interest of ent-kaurane diterpenoids, alone or in combination with a cytotoxic agent, in cancer and more precisely against HCC.

  13. The Roles of Regulatory B Cells in Cancer

    Directory of Open Access Journals (Sweden)

    Yan He

    2014-01-01

    Full Text Available Regulatory B cells (Bregs, a newly described subset of B cells, have been proved to play a suppressive role in immune system. Bregs can inhibit other immune cells through cytokines secretion and antigen presentation, which give them the role in the pathogenesis of autoimmune diseases and cancers. There are no clear criteria to identify Bregs; different markers were used in the different experimental conditions. Massive researches had described the functions of immune cells such as regulatory T cells (Tregs, dendritic cells (DCs, and B cells in the autoimmune disorder diseases and cancers. More and more researches focused on the roles of Bregs and the cytokines such as Interleukin-10 (IL-10 and transforming growth factor beta (TGF-β secreted by Bregs. The aim of this review is to summarize the characteristics of Bregs and the roles of Bregs in cancer.

  14. Random Secretion of Growth Hormone in Humans

    Science.gov (United States)

    Prank, Klaus; Kloppstech, Mirko; Nowlan, Steven J.; Sejnowski, Terrence J.; Brabant, Georg

    1996-08-01

    In normal humans, growth hormone (GH) is secreted from a gland located adjacent to the brain (pituitary) into the blood in distinct pulses, but in patients bearing a tumor within the pituitary (acromegaly) GH is excessively secreted in an irregular manner. It has been hypothesized that GH secretion in the diseased state becomes random. This hypothesis is supported by demonstrating that GH secretion in patients with acromegaly cannot be distinguished from a variety of linear stochastic processes based on the predictability of the fluctuations of GH concentration in the bloodstream.

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

    Borovečki, Ana; Korać, Petra; Nola, Marin; Ivanković, Davor; Jakšić, 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

  17. B-Cell Hematologic Malignancy Vaccination Registry

    Science.gov (United States)

    2016-12-28

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

  18. Environmental noise and human prenatal growth

    Energy Technology Data Exchange (ETDEWEB)

    Schell, L.M.

    1981-09-01

    To determine whether chronic exposure to relatively loud noise has demonstrable biological effects in humans, a study was conducted on the effect of mother's exposure to airport noise while pregnant, and of social and biological characteristics of the family upon birthweight and gestation length. The sample of births was drawn from a community located adjacent to an international airport in the U.S., where noise levels had been measured previously. Mother's noise exposure was based upon noise levels near her residence in the community while she was pregnant. Data from 115 births were used, these being from mothers whose noise exposure history was most complete throughout the pregnancy. Using multivariate analysis to correct for family characteristics, the partial correlation coefficient for noise exposure and gestation length was negative, large, and significant in girls (r . -0.49, p less than 0.001). In boys the partial correlation coefficient was also negative but was smaller and did not quite reach statistical significance. Partial correlations with birthweight were smaller in both boys and girls and not significant. These results agree best with previous studies that suggest that noise may reduce prenatal growth. The size of the observed effects may be related to a conservative research design biased towards underestimation, as well as to the real effects of noise upon human prenatal growth.

  19. Myc regulates VEGF production in B cells by stimulating initiation of VEGF mRNA translation.

    Science.gov (United States)

    Mezquita, Pau; Parghi, Sean S; Brandvold, Kimberly A; Ruddell, Alanna

    2005-01-27

    Deregulated c-myc gene expression is associated with many human and animal cancers. Myc overexpression promotes the growth of blood and lymphatic vessels, which is due in part to induction of growth factors including vascular endothelial growth factor (VEGF). We determined that the P493-6 human B-cell line increases VEGF production 10-fold upon Myc overexpression. Myc overexpression in avian B cells similarly resulted in high level VEGF production. Real-time RT-PCR analyses showed that Myc did not alter the VEGF mRNA content of these cell lines, indicating that a post-transcriptional mechanism regulates VEGF production. VEGF mRNA translation was examined by RT-PCR analysis of monosome and polysome sucrose gradient fractions from Myc-on and Myc-off P493-6 cells. Myc increased VEGF mRNA translation initiation, as VEGF mRNA loading onto polysomes increased 14-fold in Myc-on cells, and the number of ribosomes loaded per VEGF mRNA increased threefold. This translational regulation is specific to VEGF mRNA, as total polysomes show the same sucrose gradient profile in Myc-on and Myc-off cells, with no change in the percent ribosomes in polysomes, or in the number of ribosomes per polysomal mRNA. Myc stimulates VEGF production by a rapamycin- and LY294002-sensitive pathway, which does not involve alteration of eIF4E activity.

  20. Anti-CDR3 Therapy for B-Cell Malignancies

    Science.gov (United States)

    2014-10-01

    AWARD NUMBER: W81XWH-12-1-0548 TITLE: PRINCIPAL INVESTIGATOR: Anti-CDR3 Therapy for B-Cell Malignancies Dr. David Fitzgerald CONTRACTING...REPORT DATE October 2014 2. REPORT TYPE Annual 3. DATES COVERED (From - To) 30 Sep 2013 - 29 Sep 2014 "Anti-CDR3 Therapy for B-Cell Malignancies” 5a...and light chains, into a model antibody 4D5 (see figures 1-5 in the report). The "Tomlinson" human antibody phage library will be used to pan for

  1. Dimensiones del crecimiento humano Human growth dimensions

    Directory of Open Access Journals (Sweden)

    José María Barrio Maestre

    2007-06-01

    Full Text Available Desde la óptica propia de la Antropología Pedagógica, este artículo trata de poner de relieve el esencial inacabamiento de la persona, susceptible siempre de "ser más" como persona, y en qué medida la educación puede estimular su crecimiento. Analiza con cierto detalle las diversas facetas del desarrollo intelectual, haciendo especial hincapié en el sentido crítico y en las maneras adecuadas o impropias de promoverlo desde la actividad docente. También estudia las dimensiones esenciales del crecimiento moral de la persona, la posibilidad, necesidad y condiciones de legitimidad de una influencia asertiva explícitamente moralizante, así como la relación que existe entre la educación moral y la educación cívica. Se enfocan, igualmente, aspectos del desarrollo afectivo de la persona y su sinergia con las dimensiones del crecimiento ya mencionadas. Por último, se hacen algunas observaciones acerca del desarrollo de la dimensión religiosa y su importancia educativa.This paper, based on the findings of pedagogic anthropology, highlights the essential endlessness of the human person -who is always prone to "being more" as a person- and considers to what extent education can enhance human growth. The different stages of intellectual development are analyzed in some detail, emphasizing the critical sense and the adequate or inadequate ways of promoting such development through teaching. The paper also studies the essential domains of the person's moral growth and the possibility, necessity and legitimacy conditions of an explicitly moralizing assertive influence as well as the links between moral education and civic education. Likewise, aspects of the person's affective development and their synergy with the above mentioned growth domains are focused. Finally, some commentaries are made on the development of the religious domain and its educational importance.

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

    Science.gov (United States)

    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 EμCyclinD1 is not sufficient to induce lymphomas, EμCyclinD1 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.

  3. Early B-cell Specific Inactivation of ATM Synergizes with Ectopic CyclinD1 Expression to Promote Pre-germinal center B-cell Lymphomas in Mice

    Science.gov (United States)

    Yamamoto, Kenta; Lee, Brian J.; Li, Chen; Dubois, Richard L.; Hobeika, Elias; Bhagat, Govind; Zha, Shan

    2017-01-01

    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 (B-NHL), 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 naïve 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. While EμCyclinD1 is not sufficient to induce lymphomas, EμCyclinD1 accelerates the kinetics and increased the incidence of clonal lymphomas in ATM-deficient B-cells and skews the lymphomas towards pre-GC derived small lymphocytic neoplasms sharing morphological features of human MCL. This is in part due to CyclinD1-driven expansion of ATM-deficient naïve B cells with genomic instability, which promotes the deletions of additional tumor suppressor genes (i.g. Trp53, Mll2, Rb1 and Cdkn2a). Together these findings define a synergistic function of ATM and CyclinD1 in pre-germinal center B-cell proliferation and lymphomagenesis and provide a prototypic animal model to study the pathogenesis of human MCL. PMID:25676421

  4. [Single B cell monoclonal antibody technologies and applications].

    Science.gov (United States)

    Chi, Xiangyang; Yu, Changming; Chen, Wei

    2012-06-01

    Monoclonal antibodies (mAbs) contribute a lot to the development of numerous fields in life science as a pivotal tool in modern biological research. Development of the PCR methods and maturation of antibody production have made it possible to generate mAbs from single human B cells by single cell RT-PCR with successional cloning and expression in vitro. Compared to traditional monoclonal antibody technologies, single B cell technologies require relatively fewer cells, which are highly efficient in obtaining specific mAbs in a rapid way with preservation of the natural heavy and light chain pairing. With so many advantages, single B cell technologies have been proved to be an attractive approach for retrieval of naive and antigen-experienced antibody repertoires generated in vivo, design of rationale structure-based vaccine, evaluation and development of basic B cell biology concepts in health and autoimmunity, and prevention of infectious diseases by passive immunization and therapy for disorders. Accordingly, this review introduced recent progresses in the single B cell technologies for generating monoclonal antibodies and applications.

  5. BCR ligation antagonizes the IL-21 enhancement of anti-CD40/IL-4 plasma cell differentiation and IgE production found in low density human B cell cultures.

    Science.gov (United States)

    Caven, Timothy H; Sturgill, Jamie L; Conrad, Daniel H

    2007-05-01

    We sought to discover the mechanisms explaining increased IgE production seen at low cell densities when IL-21 is added to human B cell cultures activated with anti-CD40 and IL-4. When cells were cultured in the absence of BCR ligation, qPCR demonstrated dramatic increases in mRNA for the plasma cell transcription factors BLIMP1 and XBP1. Furthermore, a majority of viable cells expressed high levels of CD38 while losing expression of surface IgD. In contrast, in the presence of BCR stimulation, both the XBP1 mRNA levels and CD38 cell surface expression were markedly reduced, and a large population of cells retained IgD expression, indicating reduced plasma cell differentiation. IgE levels were reduced in the BCR stimulated cultures by 90%, while IgG4 levels remained unchanged. In summary, IL-21 enhances IgE production at low densities through stimulating cell division and plasma cell differentiation and this activity is reduced upon BCR cross-linking.

  6. Single dose and pulsatile treatment with human growth hormone in growth hormone deficiency.

    OpenAIRE

    P. J. Smith; Pringle, P J; Brook, C. G.

    1987-01-01

    The growth and growth hormone profiles in four children receiving three different regimens of treatment with human growth hormone (hGH) were compared. There was no significant difference in the rate of growth between the regimens; the rate of growth fell dramatically after treatment. Pulsatile administration of hGH was no better than conventional treatment.

  7. Human Capital Development and Economic Growth: The Nigeria Experience

    OpenAIRE

    God’stime Osekhebhen Eigbiremolen; Uchechi Shirley Anaduaka

    2014-01-01

    This study employs the augmented Solow human-capital-growth model to investigate the impact of human capital development on national output, a proxy for economic growth, using quarterly time-series data from 1999-2012. Empirical results show that human capita development, in line with theory, exhibits significant positive impact on output level. This implies that human capital development is indispensable in the achievement of sustainable economic growth in Nigeria, as there is an increase in...

  8. Regulatory B cells contribute to the impaired antitumor immunity in ovarian cancer patients.

    Science.gov (United States)

    Wei, Xin; Jin, Yangqiu; Tian, Yinpu; Zhang, Huiyuan; Wu, Jie; Lu, Wei; Lu, Xiaofen

    2016-05-01

    Multiple factors in the tumor microenvironment were found to inhibit antitumor adaptive immune responses, allowing tumor persistence and growth. In this study, ascites from ovarian cancer patients were collected. We observed that a population of interleukin-10(+) B (IL-10(+) B) cells was preferentially enriched in the ascites. This population was associated with naive B cell phenotype or IgM or class-switched memory B cell phenotypes. The frequencies of IL-10(+) B cells were negatively correlated with the frequencies of interferon gamma-producing (IFN-g(+)) CD8(+) T cells and were positively correlated with the frequencies of Foxp3(+) CD4(+) T cells. To examine whether increased IL-10(+) B cells in ascites could directly result in increased suppression of IFN-g production by CD8(+) T cells, we cocultured CD8(+) T cells with autologous blood B cells or ascitic B cells and found that CD8(+) T cells cocultured with ascitic B cells demonstrated significantly suppressed IFN-g production. This suppression was in part mediated by IL-10 as well as low CD80/CD86 expression, since depletion of IL-10 and stimulation of CD28 partially reverted IL-10(+) B cell-mediated suppression. Together, these data demonstrated an additional regulatory mechanism in the tumor microenvironment, which utilizes IL-10(+) B cells.

  9. How Does Human Capital Affect on Growth in Different Economies?

    Directory of Open Access Journals (Sweden)

    Mehdi Safdari

    2010-01-01

    Full Text Available Problem statement: The main objective of this study was to investigate how human capital can affect growth in different economies. Approach: For this purpose, we investigated the model, which the growth rate of total factor productivity depends on human capital stock level using a cross-country panel approach for 104 countries in five-year intervals during the 1980-2005. Results: The finding of this study showed that human capital through its effect on the speed of technology adoption from abroad has positive effect and significantly on growth in total samples of countries while human capital directly in developed countries enter negatively inverse developing countries. Conclusion: Moreover human capital affects growth in different ways it has more effects on per capital growth through technology/catch-up component than domestic innovation component. Moreover human capital of different ways has different effects on growth but in total it has positive effect on economic growth.

  10. Naïve and memory B cells exhibit distinct biochemical responses following BCR engagement.

    Science.gov (United States)

    Moens, Leen; Kane, Alisa; Tangye, Stuart G

    2016-09-01

    Immunological memory is characterized by the rapid reactivation of memory B cells that produce large quantities of high-affinity antigen-specific antibodies. This contrasts the response of naïve B cells, and the primary immune response, which is much slower and of lower affinity. Memory responses are critical for protection against infectious diseases and form the basis of most currently available vaccines. Although we have known about the phenomenon of long-lived memory for centuries, the biochemical differences underlying these diverse responses of naïve and memory B cells is incompletely resolved. Here we investigated the nature of B-cell receptor (BCR) signaling in human splenic naïve, IgM(+) memory and isotype-switched memory B cells following multivalent BCR crosslinking. We observed comparable rapid and transient phosphorylation kinetics for proximal (phosphotyrosine and spleen tyrosine kinase) and propagation (B-cell linker, phospholipase Cγ2) signaling components in these different B-cell subsets. However, the magnitude of activation of downstream components of the BCR signaling pathway were greater in memory compared with naïve cells. Although no differences were observed in the magnitude of Ca(2+) mobilization between subsets, IgM(+) memory B cells exhibited a more rapid Ca(2+) mobilization and a greater depletion of the Ca(2+) endoplasmic reticulum stores, while IgG(+) memory B cells had a prolonged Ca(2+) uptake. Collectively, our findings show that intrinsic signaling features of B-cell subsets contribute to the robust response of human memory B cells over naïve B cells. This has implications for our understanding of memory B-cell responses and provides a framework to modulate these responses in the setting of vaccination and immunopathologies, such as immunodeficiency and autoimmunity.

  11. Crystal structure of a Staphylococcus aureus protein A domain complexed with the Fab fragment of a human IgM antibody: structural basis for recognition of B-cell receptors and superantigen activity.

    Science.gov (United States)

    Graille, M; Stura, E A; Corper, A L; Sutton, B J; Taussig, M J; Charbonnier, J B; Silverman, G J

    2000-05-09

    Staphylococcus aureus produces a virulence factor, protein A (SpA), that contains five homologous Ig-binding domains. The interactions of SpA with the Fab region of membrane-anchored Igs can stimulate a large fraction of B cells, contributing to lymphocyte clonal selection. To understand the molecular basis for this activity, we have solved the crystal structure of the complex between domain D of SpA and the Fab fragment of a human IgM antibody to 2.7-A resolution. In the complex, helices II and III of domain D interact with the variable region of the Fab heavy chain (V(H)) through framework residues, without the involvement of the hypervariable regions implicated in antigen recognition. The contact residues are highly conserved in human V(H)3 antibodies but not in other families. The contact residues from domain D also are conserved among all SpA Ig-binding domains, suggesting that each could bind in a similar manner. Features of this interaction parallel those reported for staphylococcal enterotoxins that are superantigens for many T cells. The structural homology between Ig V(H) regions and the T-cell receptor V(beta) regions facilitates their comparison, and both types of interactions involve lymphocyte receptor surface remote from the antigen binding site. However, T-cell superantigens reportedly interact through hydrogen bonds with T-cell receptor V(beta) backbone atoms in a primary sequence-independent manner, whereas SpA relies on a sequence-restricted conformational binding with residue side chains, suggesting that this common bacterial pathogen has adopted distinct molecular recognition strategies for affecting large sets of B and T lymphocytes.

  12. Epigenetic Impact on EBV Associated B-Cell Lymphomagenesis

    Directory of Open Access Journals (Sweden)

    Shatadru Ghosh Roy

    2016-11-01

    Full Text Available Epigenetic modifications leading to either transcriptional repression or activation, play an indispensable role in the development of human cancers. Epidemiological study revealed that approximately 20% of all human cancers are associated with tumor viruses. Epstein-Barr virus (EBV, the first human tumor virus, demonstrates frequent epigenetic alterations on both viral and host genomes in associated cancers—both of epithelial and lymphoid origin. The cell type-dependent different EBV latent gene expression patterns appear to be determined by the cellular epigenetic machinery and similarly viral oncoproteins recruit epigenetic regulators in order to deregulate the cellular gene expression profile resulting in several human cancers. This review elucidates the epigenetic consequences of EBV–host interactions during development of multiple EBV-induced B-cell lymphomas, which may lead to the discovery of novel therapeutic interventions against EBV-associated B-cell lymphomas by alteration of reversible patho-epigenetic markings.

  13. Antigen-specific monoclonal antibodies isolated from B cells expressing constitutively active STAT5.

    Directory of Open Access Journals (Sweden)

    Ferenc A Scheeren

    Full Text Available BACKGROUND: Fully human monoclonal antibodies directed against specific pathogens have a high therapeutic potential, but are difficult to generate. METHODOLOGY/PRINCIPAL FINDINGS: Memory B cells were immortalized by expressing an inducible active mutant of the transcription factor Signal Transducer and Activator of Transcription 5 (STAT5. Active STAT5 inhibits the differentiation of B cells while increasing their replicative life span. We obtained cloned B cell lines, which produced antibodies in the presence of interleukin 21 after turning off STAT5. We used this method to obtain monoclonal antibodies against the model antigen tetanus toxin. CONCLUSIONS/SIGNIFICANCE: Here we describe a novel and relatively simple method of immortalizing antigen-specific human B cells for isolation of human monoclonal antibodies. These results show that STAT5 overexpression can be employed to isolate antigen specific antibodies from human memory B cells.

  14. Human placental lactogen and intrauterine growth retardation.

    Science.gov (United States)

    Spellacy, W N; Buhi, W C; Birk, S A

    1976-04-01

    Serum human placental lactogen levels were measured after 36 weeks' gestation in 264 serum samples from 109 women with normal pregnancies and in 137 serum samples from 70 women with pregnancies complicated by fetal intrauterine growth retardation (IGR). The fetal and placental weights were significantly lower in the IGR groups while the maternal ages were not different. There was a significantly lower hPL value at each week from 36 to 41 (except for the 39th) in the IGR group. Sixty percent of the women with IGR had hPL values less than 6 mug/ml, and 18.6% were less than 4 mug/ml. It is suggested that a low serum hPL value obtained during the last month of pregnancy should alert the physician to the possibility of intrauterine problems, including IGR.

  15. Dimerization of Human Growth Hormone by Zinc

    Science.gov (United States)

    Cunningham, Brian C.; Mulkerrin, Michael G.; Wells, James A.

    1991-08-01

    Size-exclusion chromatography and sedimentation equilibrium studies demonstrated that zinc ion (Zn2+) induced the dimerization of human growth hormone (hGH). Scatchard analysis of 65Zn2+ binding to hGH showed that two Zn2+ ions associate per dimer of hGH in a cooperative fashion. Cobalt (II) can substitute for Zn2+ in the hormone dimer and gives a visible spectrum characteristic of cobalt coordinated in a tetrahedral fashion by oxygen- and nitrogen-containing ligands. Replacement of potential Zn2+ ligands (His18, His21, and Glu174) in hGH with alanine weakened both Zn2+ binding and hGH dimer formation. The Zn2+-hGH dimer was more stable than monomeric hGH to denaturation in guanidine-HCl. Formation of a Zn2+-hGH dimeric complex may be important for storage of hGH in secretory granules.

  16. Autodecomposition of radiolabeled human growth hormone

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, G.; Amburn, K.

    1986-01-01

    Human growth hormone (hGH) was radiolabeled with /sup 125/I, using a gentle lactoperoxidase technique. The stability and decomposition products of this tracer were studied by frequent periodic analysis by Sephadex G-100 chromatography on a long column. Monomeric /sup 125/I-hGH showed an exponential decline, with a half-life of 61 days. The main radioactive degradation product was iodide, which appeared with a fractional appearance rate of 0.01136 per day. Secondary degradation products were a series of radioactive oligomers of hGH, which appeared with an overall fractional rate of 0.00525 per day. The kinetic data obtained should provide guidelines for the shelf-life and repurification schedule of radioiodinated polypeptides.

  17. Extrapituitary growth hormone synthesis in humans.

    Science.gov (United States)

    Pérez-Ibave, Diana Cristina; Rodríguez-Sánchez, Iram Pablo; Garza-Rodríguez, María de Lourdes; Barrera-Saldaña, Hugo Alberto

    2014-01-01

    The gene for pituitary growth hormone (GH-N) in man belongs to a multigene locus located at chromosome 17q24.2, which also harbors four additional genes: one for a placental variant of GH-N (named GH-V) and three of chorionic somatommamotropin (CSH) type. Their tandem arrangement from 5' to 3' is: GH-N, CSH-L, CSH-1, GH-V and CSH-2. GH-N is mainly expressed in the pituitary from birth throughout life, while the remaining genes are expressed in the placenta of pregnant women. Pituitary somatotrophs secrete GH into the bloodstream to act at receptor sites in most tissues. GH participates in the regulation of several complex physiological processes, including growth and metabolism. Recently, the presence of GH has been described in several extrapituitary sites, such as neural, ocular, reproductive, immune, cardiovascular, muscular, dermal and skeletal tissues. It has been proposed that GH has an autocrine action in these tissues. While the body of evidence for its presence is constantly growing, research of its possible function and implications lag behind. In this review we highlight the evidence of extrapituitary synthesis of GH in humans.

  18. Apoptosis of HL-60 human leukemia cells induced by Asiatic acid through modulation of B-cell lymphoma 2 family proteins and the mitogen-activated protein kinase signaling pathway.

    Science.gov (United States)

    Wu, Qiuling; Lv, Tingting; Chen, Yan; Wen, Lu; Zhang, Junli; Jiang, Xudong; Liu, Fang

    2015-07-01

    The toxicities of conventional chemotherapeutic agents to normal cells restrict their dosage and clinical efficacy in acute leukemia; therefore, it is important to develop novel chemotherapeutics, including natural products, which selectively target cancer-specific pathways. The present study aimed to explore the effect of the chemopreventive agent asiatic acid (AA) on the proliferation and apoptotic rate of the leukemia cell line HL-60 and investigated the mechanisms underlying its anti-tumor activity. The effect of AA on the proliferation of HL-60 cells was evaluated using the MTT assay. Annexin V-fluorescein isothiocyanate/propidium iodide double staining followed by flow cytometric analysis as well as Hoechst 33258 staining were used to analyze the apoptotic rate of the cells. Furthermore, changes of survivin, B-cell lymphoma 2 (Bcl-2), myeloid cell leukemia 1 (Mcl-1), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 expressions were detected by western blot analysis. AA blocked the growth of HL-60 cells in a dose- and time-dependent manner. The IC50-value of AA on HL-60 cells was 46.67 ± 5.08 µmol/l for 24 h. AA induced apoptosis in a dose-dependent manner, which was inhibited in the presence of Z-DEVD-FMK, a specific inhibitor of caspase. The anti-apoptotic proteins Bcl-2, Mcl-1 and survivin were downregulated by AA in a dose-dependent manner. Concurrently, AA inhibited ERK and p38 phosphorylation in a dose-dependent manner, while JNK phosphorylation was not affected. In conclusion, the present study indicated that the p38 and ERK pathways, as well as modulation of Bcl-2 family and survivin proteins were key regulators of apoptosis induced in HL-60 cells in response to AA.

  19. Human Population: Fundamentals of Growth and Change.

    Science.gov (United States)

    Stauffer, Cheryl Lynn, Ed.

    This booklet focuses on eight elements of population dynamics: "Population Growth and Distribution"; "Natural Increase and Future Growth"; "Effect of Migration on Population Growth"; "Three Patterns of Population Change"; "Patterns of World Urbanization"; "The Status of Women";…

  20. B cell depletion inhibits spontaneous autoimmune thyroiditis in NOD.H-2h4 mice.

    Science.gov (United States)

    Yu, Shiguang; Dunn, Robert; Kehry, Marilyn R; Braley-Mullen, Helen

    2008-06-01

    B cells are important for the development of most autoimmune diseases. B cell depletion immunotherapy has emerged as an effective treatment for several human autoimmune diseases, although it is unclear whether B cells are necessary for disease induction, autoantibody production, or disease progression. To address the role of B cells in a murine model of spontaneous autoimmune thyroiditis (SAT), B cells were depleted from adult NOD.H-2h4 mice using anti-mouse CD20 mAb. Anti-CD20 depleted most B cells in peripheral blood and cervical lymph nodes and 50-80% of splenic B cells. Flow cytometry analysis showed that marginal zone B cells in the spleen were relatively resistant to depletion by anti-CD20, whereas most follicular and transitional (T2) B cells were depleted after anti-CD20 treatment. When anti-CD20 was administered before development of SAT, development of SAT and anti-mouse thyroglobulin autoantibody responses were reduced. Anti-CD20 also reduced SAT severity and inhibited further increases in anti-mouse thyroglobulin autoantibodies when administered to mice that already had autoantibodies and thyroid inflammation. The results suggest that B cells are necessary for initiation as well as progression or maintenance of SAT in NOD.H-2h4 mice.

  1. Natalizumab treatment leads to an increase in circulating CXCR3-expressing B cells

    Science.gov (United States)

    Penttilä, Tarja-Leena; Airas, Laura

    2016-01-01

    Objective: To study the effects of natalizumab treatment on subgroups of circulating peripheral blood B cell populations. Methods: We studied the proportions and absolute numbers of CD19+CD20+, CD10+, and CD5+ B cell populations, and determined very late activation antigen-4 and chemokine receptor CXCR3, CCR5, and CCR6 expression on B cells in the peripheral blood of 14 natalizumab-treated patients with relapsing-remitting multiple sclerosis. Five blood samples per patient were obtained longitudinally before and during the first year of treatment. Blood samples were analyzed by 6-color flow cytometry. Results: Proportions of B cells and CD10+ pre–B cells were significantly increased, and very late activation antigen-4 expression on the B cell surface was significantly decreased already after 1 week of natalizumab treatment. Natalizumab-induced sustained increase in the proportion and absolute number of CXCR3-expressing B cells was statistically significant after 1 month of treatment. There were no changes in the proportions of CCR5- or CCR6-expressing B cells. Conclusions: The rapid and persistent increase in circulating CXCR3-expressing B cells in response to natalizumab treatment possibly reflects the relevance of this chemokine receptor in controlling migration of B cells into the CNS in humans in vivo. PMID:27800533

  2. Advances on molecular mechanism of B cell development related with lymphomagenesis in human germinal centres%生发中心B细胞发育和淋巴瘤发生的分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    欧阳斌燊

    2011-01-01

    生发中心是B细胞成熟和发育的场所,生发中心B细胞的活化和分化受复杂的内在信号和转录因子网络调控.正常情况下,这些转录因子之间的相互作用维持着生发中心内B细胞的动态稳定.当机体细胞遗传学发生改变、病毒感染等,多种转录因子的异常表达引起B细胞内在信号网络调节失去平衡,表现为B细胞增殖异常,凋亡、分化受阻.B细胞恶性肿瘤常与B细胞的遗传学改变及生发中心转录因子异常表达有关.%Germinal center is a site of B cell maturation and development, in which B cell activation and differentiation was regulated by inherent complexity signal and transcription factors networks. Under the normal condition, the interaction between these transcription factors maintain dynamic stability of B cell in germinal center. When cytogenetic abnormalities or viral infection appear, a variety of.abnormal expression of transcription factors induced the imbalance of B cell signal networks regulation. manifested as abnormal B cell proliferation, apoptosis, and differentiation was blocked. B cell malignancies were often associated with genetic change of B cell and abnormal expression of transcription factors.

  3. CD40 ligand is necessary and sufficient to support primary diffuse large B-cell lymphoma cells in culture: a tool for in vitro preclinical studies with primary B-cell malignancies

    Science.gov (United States)

    Ito, Daisuke; Frantz, Aric M.; Williams, Christina; Thomas, Rachael; Burnett, Robert C.; Avery, Anne C.; Breen, Matthew; Mason, Nicola J.; O’Brien, Timothy D.; Modiano, Jaime F.

    2013-01-01

    Established cell lines are utilized extensively to study tumor biology and preclinical therapeutic development; however, they may not accurately recapitulate the heterogeneity of their corresponding primary disease. B-cell tumor cells are especially difficult to maintain under conventional culture conditions, limiting access to samples that faithfully represent this disease for preclinical studies. Here, we used primary canine diffuse large B-cell lymphoma to establish a culture system that reliably supports the growth of these cells. CD40 ligand, either expressed by feeder cells or provided as a soluble two-trimeric form, was sufficient to support primary lymphoma cells in vitro. The tumor cells retained their original phenotype, clonality and known karyotypic abnormalities after extended expansion in culture. Finally, we illustrate the utility of the feeder cell-free culture system for comparable assessment of cytotoxicity using dog and human B-cell malignancies. We conclude this system has broad applications for in vitro preclinical development for B-cell malignancies. PMID:22229753

  4. MicroRNA-146a modulates B-cell oncogenesis by regulating Egr1.

    Science.gov (United States)

    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

    2015-05-10

    miR-146a is a NF-κB 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-κB 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.

  5. MicroRNA-146a modulates B-cell oncogenesis by regulating Egr1

    Science.gov (United States)

    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-κB 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-κB 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

  6. Clear cell variant of diffuse large B-cell lymphoma: a case report

    Directory of Open Access Journals (Sweden)

    Sahatciu-Meka Vjollca

    2011-05-01

    Full Text Available Abstract Introduction Diffuse large B-cell lymphoma is a diffuse proliferation of large neoplastic B lymphoid cells with a nuclear size equal to or exceeding the normal macrophage nuclei. We report a case of a clear cell variant of diffuse large B-cell lymphoma involving a lymph node in the neck, which was clinically suspected of being metastatic carcinoma. Case presentation A 39-year-old Caucasian ethnic Albanian man from Kosovo presented with a rapidly enlarging lymph node in his neck, but he also disclosed B symptoms and fatigue. A cytological aspirate of the lymph node revealed pleomorphic features. Our patient underwent a cervical lymph node biopsy (large excision. The mass was homogeneously fish-flesh, pale white tissue replacing almost the whole structure of the lymph node. The lymph node biopsy showed a partial alveolar growth pattern, which raised clinical suspicion that it was an epithelial neoplasm. With regard to morphological and phenotypic features, we discovered large nodules in diffuse areas, comprising large cells with slightly irregular nuclei and clear cytoplasm admixed with a few mononuclear cells. In these areas, there was high mitotic activity, and in some areas there were macrophages with tangible bodies. Staining for cytokeratins was negative. These areas had the following phenotypes: cluster designation marker 20 (CD20 positive, B-cell lymphoma (Bcl-2-positive, Bcl-6-, CD5-, CD3-, CD21+ (in alveolar patterns, prostate-specific antigen-negative, human melanoma black marker 45-negative, melanoma marker-negative, cytokeratin-7-negative and multiple myeloma marker 1-positive in about 30% of cells, and exhibited a high proliferation index marker (Ki-67, 80%. Conclusion According to the immunohistochemical findings, we concluded that this patient has a clear cell variant of diffuse large B-cell lymphoma of activated cell type, post-germinal center cell origin. Our patient is undergoing R-CHOP chemotherapy treatment.

  7. Interactions between fibroblastic reticular cells and B cells promote mesenteric lymph node lymphangiogenesis.

    Science.gov (United States)

    Dubey, Lalit Kumar; Karempudi, Praneeth; Luther, Sanjiv A; Ludewig, Burkhard; Harris, Nicola L

    2017-08-28

    Lymphatic growth (lymphangiogenesis) within lymph nodes functions to promote dendritic cell entry and effector lymphocyte egress in response to infection or inflammation. Here we demonstrate a crucial role for lymphotoxin-beta receptor (LTβR) signaling to fibroblastic reticular cells (FRCs) by lymphotoxin-expressing B cells in driving mesenteric lymph node lymphangiogenesis following helminth infection. LTβR ligation on fibroblastic reticular cells leads to the production of B-cell-activating factor (BAFF), which synergized with interleukin-4 (IL-4) to promote the production of the lymphangiogenic factors, vascular endothelial growth factors (VEGF)-A and VEGF-C, by B cells. In addition, the BAFF-IL-4 synergy augments expression of lymphotoxin by antigen-activated B cells, promoting further B cell-fibroblastic reticular cell interactions. These results underlie the importance of lymphotoxin-dependent B cell-FRC cross talk in driving the expansion of lymphatic networks that function to promote and maintain immune responsiveness.The growth of lymph nodes in response to infection requires lymphangiogenesis. Dubey et al. show that the mesenteric lymph node lymphangiogenesis upon helminth infection depends on the signaling loop between the B and fibroblastic reticular cells (FRCs), whereby the FRCs respond to lymphotoxin secreted by B cells by releasing B cell activating factor.

  8. Signaling Proteins and Transcription Factors in Normal and Malignant Early B Cell Development

    Directory of Open Access Journals (Sweden)

    Patricia Pérez-Vera

    2011-01-01

    Full Text Available B cell development starts in bone marrow with the commitment of hematopoietic progenitors to the B cell lineage. In murine models, the IL-7 and preBCR receptors, and the signaling pathways and transcription factors that they regulate, control commitment and maintenance along the B cell pathway. E2A, EBF1, PAX5, and Ikaros are among the most important transcription factors controlling early development and thereby conditioning mice homeostatic B cell lymphopoiesis. Importantly, their gain or loss of function often results in malignant development in humans, supporting conserved roles for these transcription factors. B cell acute lymphoblastic leukemia is the most common cause of pediatric cancer, and it is characterized by unpaired early B cell development resulting from genetic lesions in these critical signaling pathways and transcription factors. Fine mapping of these genetic abnormalities is allowing more specific treatments, more accurately predicting risk profiles for this disease, and improving survival rates.

  9. B Cells and Autoantibodies in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Anne-Katrin Pröbstel

    2015-07-01

    Full Text Available 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.

  10. The Asymmetric Impact of Growth Fluctuation on Human Development

    OpenAIRE

    Serap Bedir

    2015-01-01

    In this paper, we re-examine the impact of economic growth fluctuation on human development indicators. Using the per capita growth rate and human development indicators for 131 countries between 1974 and 2007, we find that growth acceleration and deceleration have significant impact on the human development indicators. We also find that the effects are asymmetric. This asymmetric effect is valid both in terms of acceleration and deceleration periods and countries which are classified accordi...

  11. Human severe combined immunodeficiency disease: phenotypic and functional characteristics of peripheral B lymphocytes.

    Science.gov (United States)

    Gougeon, M L; Drean, G; Le Deist, F; Dousseau, M; Fevrier, M; Diu, A; Theze, J; Griscelli, C; Fischer, A

    1990-11-01

    Human severe combined immunodeficiency disease (SCID) includes an X-chromosome-linked type characterized by a complete absence of mature T cells, hypogammaglobulinemia but normal or elevated number of B cells, suggesting that the disease results from a block in early T cell differentiation. It has been shown that B cells from obligate carrier women of this disorder exhibit the preferential use of the nonmutant X chromosome as the active X (as shown for T cells), suggesting that the SCID gene product has a direct effect on B cells as well as on T cells. To examine this question, we analyzed the phenotypic and functional characteristics of peripheral B cells from nine infants with SCID. We found a constant absence of spontaneously expressed activation Ag on B cell membrane from all SCID patients tested which contrasts with the phenotypic pattern exhibited by age-matched infants whom all cells bearing surface Ig express the 4F2 Ag and to a lesser extent the transferrin receptor. Concurrently, B cells from SCID patients have a profound impairment in their responses to stimuli that induce in vitro B cell proliferation and differentiation. Although rIL-2 and low-Mr B cell growth factor are potent inducers of proliferation on age-matched infants' B cells, they are poorly efficient in inducing proliferation of anti-mu-activated SCID B cells. This impairment is not related to the resting B cell phenotype of SCID B cells as shown by comparison with normal resting B cells. Furthermore, we observed an apparent block in B cell differentiation inasmuch as neither rIL-2 nor rIL-6 could support SAC-activated SCID B cell differentiation, both lymphokines being very efficient in inducing SAC-activated age-matched infants' B cell or purified resting B cell differentiation. These results suggest that the SCID gene defect has a direct effect on B cells and is required during B cell maturation.

  12. Establishment of multi-drug resistance human B-cell lymphoma cell line BJAB/ADR and preliminary research of its drug-resistance mechanism%人类B细胞淋巴瘤耐药细胞株BJAB/ADR的建立及其耐药机制的初步研究

    Institute of Scientific and Technical Information of China (English)

    鲍世琦; 姜琳琳; 张晓龙; 李真真; 邵晓枫; 齐怀丰; 杨雨琪; 熊冬生

    2014-01-01

    目的 建立人类淋巴瘤B JAB多药耐药细胞株BJAB/ADR,并初步研究其耐药机制.方法 采用多柔比星浓度梯度递增法建立人类B细胞淋巴瘤耐药细胞模型BJAB/ADR,观察其生长规律并绘制细胞生长曲线;用四甲基偶氮唑蓝(MTT)法鉴定耐药细胞株对多种化疗药物的耐药性并计算耐药指数;提取耐药细胞株RNA,实时定量聚合酶链反应(PCR)法检测相关耐药基因MDR1 mRNA的表达;流式细胞术检测细胞表面P糖蛋白(Pgp)的表达;通过罗丹明外排实验,检测Pgp功能.结果 成功建立B细胞淋巴瘤耐药细胞模型BJAB/ADR,并在160 ng/ml多柔比星溶液中稳定生长,耐药细胞较敏感细胞生长缓慢,细胞形态无明显变化.MTT检测结果表明BJAB/ADR细胞对多柔比星的耐药指数为43倍,同时对柔红霉素、依托泊苷、高三尖杉酯碱(HHT)及米托蒽醌(MX)也具有一定的耐药性.实时定量PCR结果表明,耐药细胞BJAB/ADR MDRl mRNA明显高于药物敏感细胞BJAB(P< 0.01).流式细胞术检测结果显示,耐药细胞表面Pgp高表达;罗丹明外排实验表明Pgp对多柔比星具有外排功能,使B JAB/ADR细胞获得耐药特性.结论 建立了人类B细胞淋巴瘤的耐药细胞株BJAB/ADR,其对多柔比星耐药性稳定,并呈现多药耐药细胞的基本生物学特性,为进一步研究肿瘤多药耐药发生的机制及逆转耐药提供有利的模型.%Objective To establish human multi-drug resistance (MDR) B-cell lymphoma cell line BJAB/ADR and investigate its biological characteristics.Methods Human B-cell lymphoma MDR cell line BJAB/ADR was induced by exposure to increasing dose of adriamycin.The growing features of BJAB/ADR were observed and cell growth was measured,IC50 of antitumor agents was evaluated by MTT assay.The expression of MDR1 mRNA was determined with real-time PCR,FACS was applied to study the expression of MDR protein P-glycoprotein (Pgp) and Rhodamine 123R efflux assay was used to

  13. Impaired precursor B cell differentiation in Bruton's tyrosine kinase-deficient mice

    NARCIS (Netherlands)

    S. Middendorp; G.M. Dingjan (Gemma); R.W. Hendriks (Rudi)

    2002-01-01

    textabstractBruton's tyrosine kinase (Btk) is a cytoplasmic signaling molecule that is crucial for precursor (pre-B) cell differentiation in humans. In this study, we show that during the transition of large cycling to small resting pre-B cells in the mouse, Btk-deficient cells fai

  14. Impaired precursor B cell differentiation in Bruton's tyrosine kinase-deficient mice

    NARCIS (Netherlands)

    S. Middendorp; G.M. Dingjan (Gemma); R.W. Hendriks (Rudi)

    2002-01-01

    textabstractBruton's tyrosine kinase (Btk) is a cytoplasmic signaling molecule that is crucial for precursor (pre-B) cell differentiation in humans. In this study, we show that during the transition of large cycling to small resting pre-B cells in the mouse, Btk-deficient cells

  15. B cell-specific lentiviral gene therapy leads to sustained B-cell functional recovery in a murine model of X-linked agammaglobulinemia.

    Science.gov (United States)

    Kerns, Hannah M; Ryu, Byoung Y; Stirling, Brigid V; Sather, Blythe D; Astrakhan, Alexander; Humblet-Baron, Stephanie; Liggitt, Denny; Rawlings, David J

    2010-03-18

    The immunodeficiency disorder, X-linked agammaglobulinemia (XLA), results from mutations in the gene encoding Bruton tyrosine kinase (Btk). Btk is required for pre-B cell clonal expansion and B-cell antigen receptor signaling. XLA patients lack mature B cells and immunoglobulin and experience recurrent bacterial infections only partially mitigated by life-long antibody replacement therapy. In pursuit of definitive therapy for XLA, we tested ex vivo gene therapy using a lentiviral vector (LV) containing the immunoglobulin enhancer (Emu) and Igbeta (B29) minimal promoter to drive B lineage-specific human Btk expression in Btk/Tec(-/-) mice, a strain that reproduces the features of human XLA. After transplantation of EmuB29-Btk-LV-transduced stem cells, treated mice showed significant, albeit incomplete, rescue of mature B cells in the bone marrow, peripheral blood, spleen, and peritoneal cavity, and improved responses to T-independent and T-dependent antigens. LV-treated B cells exhibited enhanced B-cell antigen receptor signaling and an in vivo selective advantage in the peripheral versus central B-cell compartment. Secondary transplantation showed sustained Btk expression, viral integration, and partial functional responses, consistent with long-term stem cell marking; and serial transplantation revealed no evidence for cellular or systemic toxicity. These findings strongly support pursuit of B lineage-targeted LV gene therapy in human XLA.

  16. Germinal Center B-Cell-Associated Nuclear Protein (GANP) Involved in RNA Metabolism for B Cell Maturation.

    Science.gov (United States)

    Sakaguchi, N; Maeda, K

    2016-01-01

    Germinal center B-cell-associated nuclear protein (GANP) is upregulated in germinal center B cells against T-cell-dependent antigens in mice and humans. In mice, GANP depletion in B cells impairs antibody affinity maturation. Conversely, its transgenic overexpression augments the generation of high-affinity antigen-specific B cells. GANP associates with AID in the cytoplasm, shepherds AID into the nucleus, and augments its access to the rearranged immunoglobulin (Ig) variable (V) region of the genome in B cells, thereby precipitating the somatic hypermutation of V region genes. GANP is also upregulated in human CD4(+) T cells and is associated with APOBEC3G (A3G). GANP interacts with A3G and escorts it to the virion cores to potentiate its antiretroviral activity by inactivating HIV-1 genomic cDNA. Thus, GANP is characterized as a cofactor associated with AID/APOBEC cytidine deaminase family molecules in generating diversity of the IgV region of the genome and genetic alterations of exogenously introduced viral targets. GANP, encoded by human chromosome 21, as well as its mouse equivalent on chromosome 10, contains a region homologous to Saccharomyces Sac3 that was characterized as a component of the transcription/export 2 (TREX-2) complex and was predicted to be involved in RNA export and metabolism in mammalian cells. The metabolism of RNA during its maturation, from the transcription site at the chromosome within the nucleus to the cytoplasmic translation apparatus, needs to be elaborated with regard to acquired and innate immunity. In this review, we summarize the current knowledge on GANP as a component of TREX-2 in mammalian cells.

  17. The early history of B cells.

    Science.gov (United States)

    Cooper, Max D

    2015-03-01

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

  18. SMI of Bcl-2 TW-37 is active across a spectrum of B-cell tumors irrespective of their proliferative and differentiation status.

    Science.gov (United States)

    Al-Katib, Ayad M; Sun, Yuan; Goustin, Anton Scott; Azmi, Asfar Sohail; Chen, Ben; Aboukameel, Amro; Mohammad, Ramzi M

    2009-02-16

    The Bcl-2 family of proteins is critical to the life and death of malignant B-lymphocytes. Interfering with their activity using small-molecule inhibitors (SMI) is being explored as a new therapeutic strategy for treating B-cell tumors. We evaluated the efficacy of TW-37, a non-peptidic SMI of Bcl-2 against a range spectrum of human B-cell lines, fresh patient samples and animal xenograft models. Multiple cytochemical and molecular approaches such as acridine orange/ethidium bromide assay for apoptosis, co-immunoprecipitation of complexes and western blot analysis, caspase luminescent activity assay and apoptotic DNA fragmentation assay were used to demonstrate the effect of TW-37 on different B-cell lines, patient derived samples, as well as in animal xenograft models. Nanomolar concentrations of TW-37 were able to induce apoptosis in both fresh samples and established cell lines with IC50 in most cases of 165-320 nM. Apoptosis was independent of proliferative status or pathological classification of B-cell tumor. TW-37 was able to block Bim-Bcl-XL and Bim-Mcl-1 heterodimerization and induced apoptosis via activation of caspases -9, -3, PARP and DNA fragmentation. TW-37 administered to tumor-bearing SCID mice led to significant tumor growth inhibition (T/C), tumor growth delay (T-C) and Log10kill, when used at its maximum tolerated dose (40 mg/kg x 3 days) via tail vein. TW-37 failed to induce changes in the Bcl-2 proteins levels suggesting that assessment of baseline Bcl-2 family proteins can be used to predict response to the drug. These findings indicate activity of TW-37 across the spectrum of human B-cell tumors and support the concept of targeting the Bcl-2 system as a therapeutic strategy regardless of the stage of B-cell differentiation.

  19. Cord blood transplants for SCID: better B-cell engraftment?

    Science.gov (United States)

    Chan, Wan-Yin; Roberts, Robert Lloyd; Moore, Theodore B; Stiehm, E Richard

    2013-01-01

    Hematopoietic stem-cell transplantation is the treatment of choice for severe combined immunodeficiency (SCID). Despite successful T-cell engraftment in transplanted patients, B-cell function is not always achieved; up to 58% of patients require immunoglobulin therapy after receiving haploidentical transplants. We report 2 half-sibling males with X-linked γ-chain SCID treated with different sources of stem cells. Sibling 1 was transplanted with T-cell-depleted haploidentical maternal bone marrow and sibling 2 was transplanted with 7/8 human leukocyte antigen-matched unrelated umbilical cord blood. Both patients received pretransplant conditioning and posttransplant graft-versus-host-disease prophylaxis. B-cell engraftment and function was achieved in sibling 1 but not in sibling 2. This disparate result is consistent with a review of 19 other SCID children who received cord blood transplants. B-cell function, as indicated by no need for immunoglobulin therapy, was restored in 42% of patients given haploidentical transplants and in 68% of patients given matched unrelated donor transplants compared with 80% of patients given cord blood transplants. Cord blood is an alternative source of stem cells for transplantation in children with SCID and has a higher likelihood of B-cell reconstitution.

  20. Immunomodulatory effect of Mesenchymal Stem Cells on B cells

    Directory of Open Access Journals (Sweden)

    Marcella eFranquesa

    2012-07-01

    Full Text Available The research on T cell immunosuppression therapies has attracted most of the attention in clinical transplantation. However, B cells and humoral immune responses are increasingly acknowledged as crucial mediators of chronic allograft rejection. Indeed, humoral immune responses can lead to renal allograft rejection even in patients whose cell-mediated immune responses are well controlled. On the other hand, newly studied B cell subsets with regulatory effects have been linked to tolerance achievement in transplantation. Better understanding of the regulatory and effector B cell responses may therefore lead to new therapeutic approaches.Mesenchymal Stem Cells (MSC are arising as a potent therapeutic tool in transplantation due to their regenerative and immunomodulatory properties. The research on MSCs has mainly focused on their effects on T cells and although data regarding the modulatory effects of MSCs on alloantigen-specific humoral response in humans is scarce, it has been demonstrated that MSCs significantly affect B cell functioning. In the present review we will analyze and discuss the results in this field.

  1. Changes in Circulating B Cell Subsets Associated with Aging and Acute SIV Infection in Rhesus Macaques

    Science.gov (United States)

    Gonzalez, Denise F.; Kieu, Hung T.; Castillo, Luis D.; Messaoudi, Ilhem; Shen, Xiaoying; Tomaras, Georgia D.; Shacklett, Barbara L.; Barry, Peter A.; Sparger, Ellen E.

    2017-01-01

    Aging and certain viral infections can negatively impact humoral responses in humans. To further develop the nonhuman primate (NHP) model for investigating B cell dynamics in human aging and infectious disease, a flow cytometric panel was developed to characterize circulating rhesus B cell subsets. Significant differences between human and macaque B cells included the proportions of cells within IgD+ and switched memory populations and a prominent CD21-CD27+ unswitched memory population detected only in macaques. We then utilized the expanded panel to analyze B cell alterations associated with aging and acute simian immunodeficiency virus (SIV) infection in the NHP model. In the aging study, distinct patterns of B cell subset frequencies were observed for macaques aged one to five years compared to those between ages 5 and 30 years. In the SIV infection study, B cell frequencies and absolute number were dramatically reduced following acute infection, but recovered within four weeks of infection. Thereafter, the frequencies of activated memory B cells progressively increased; these were significantly correlated with the magnitude of SIV-specific IgG responses, and coincided with impaired maturation of anti-SIV antibody avidity, as previously reported for HIV-1 infection. These observations further validate the NHP model for investigation of mechanisms responsible for B cells alterations associated with immunosenescence and infectious disease. PMID:28095513

  2. 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

    NARCIS (Netherlands)

    Hawthorn, L; Roberts, T; Verlind, E; Kooy, RF; Cowell, JK

    1995-01-01

    Abnormalities involving chromosome 13 have been 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

  3. T-cell leukemia 1 expression in nodal Epstein-Barr virus-negative diffuse large B-cell lymphoma and primary mediastinal B-cell lymphoma.

    Science.gov (United States)

    Gualco, Gabriela; Weiss, Lawrence M; Barber, Glen N; Bacchi, Carlos E

    2010-09-01

    The physiologic expression of the product of the proto-oncogene TCL1 (T-cell leukemia 1) is primarily restricted to early embryonic cells. In nonneoplastic B cells, the expression of TCL1 is determined by the differentiation step with silencing at the germinal center stage. TCL1 protein is overexpressed in a wide variety of human diseases. It has been shown that TCL1 is a powerful B-cell oncogene, which has been implicated in the pathogenesis of various types of mature B-cell lymphomas. There is no comparative information in the literature addressing the expression of TCL1 in pediatric and adult nodal diffuse large B-cell lymphoma or primary mediastinal large B-cell lymphoma. We studied 55 cases of adult and pediatric diffuse large B-cell lymphoma and primary mediastinal large B-cell lymphoma to analyze the phenotypic profile of these lymphomas, including TCL1 expression, and its relationship with clinical outcome in different age groups. The cases were analyzed by immunohistochemistry for the expression of TCL1, CD10, BCL-2, BCL-6, and MUM1. We also evaluated c-MYC translocation by fluorescence in situ hybridization. TCL1 was observed in 11 cases, 5 pediatric and 6 adult cases, all but one diffuse large B-cell lymphoma. Pediatric cases showed a significant association between TCL1 expression, high proliferative index, and presence of c-MYC translocation. TCL1 positivity was predominantly found in germinal center phenotype diffuse large B-cell lymphoma. Overall survival was worse in adult TCL1-positive cases than pediatric ones. Primary mediastinal large B-cell lymphomas infrequently expressed TCL1 in both age groups.

  4. Regulation of B Cell to Plasma Cell Transition within the Follicular B Cell Response.

    Science.gov (United States)

    Nera, K-P; Kyläniemi, M K; Lassila, O

    2015-09-01

    Persistent humoral immunity depends on the follicular B cell response and on the generation of somatically mutated high-affinity plasma cells and memory B cells. Upon activation by an antigen, cognately activated follicular B cells and follicular T helper (TFH ) cells initiate germinal centre (GC) reaction during which high-affinity effector cells are generated. The differentiation of activated follicular B cells into plasma cells and memory B cells is guided by complex selection events, both at the cellular and molecular level. The transition of B cell into a plasma cell during the GC response involves alterations in the microenvironment and developmental state of the cell, which are guided by cell-extrinsic signals. The developmental cell fate decisions in response to these signals are coordinated by cell-intrinsic gene regulatory network functioning at epigenetic, transcriptional and post-transcriptional levels.

  5. B cell autophagy mediates TLR7-dependent autoimmunity and inflammation.

    Science.gov (United States)

    Weindel, Chi G; Richey, Lauren J; Bolland, Silvia; Mehta, Abhiruchi J; Kearney, John F; Huber, Brigitte T

    2015-01-01

    Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease, defined by loss of B cell self-tolerance that results in production of antinuclear antibodies (ANA) and chronic inflammation. While the initiating events in lupus development are not well defined, overexpression of the RNA-recognizing toll-like receptor (TLR)7 has been linked to SLE in humans and mice. We postulated that autophagy plays an essential role in TLR7 activation of B cells for the induction of SLE by delivering RNA ligands to the endosomes, where this innate immune receptor resides. To test this hypothesis, we compared SLE development in Tlr7 transgenic (Tg) mice with or without B cell-specific ablation of autophagy (Cd19-Cre Atg5(f/f)). We observed that in the absence of B cell autophagy the 2 hallmarks of SLE, ANA and inflammation, were eliminated, thus curing these mice of lupus. This was also evident in the significantly extended survival of the autophagy-deficient mice compared to Tlr7.1 Tg mice. Furthermore, glomerulonephritis was ameliorated, and the serum levels of inflammatory cytokines in the knockout (KO) mice were indistinguishable from those of control mice. These data provide direct evidence that B cells require TLR7-dependent priming through an autophagy-dependent mechanism before autoimmunity is induced, thereafter involving many cell types. Surprisingly, hyper-IgM production persisted in Tlr7.1 Tg mice in the absence of autophagy, likely involving a different activation pathway than the production of autoantibodies. Furthermore, these mice still presented with anemia, but responded with a striking increase in extramedullary hematopoiesis (EMH), possibly due to the absence of pro-inflammatory cytokines.

  6. B-cell-independent lymphoid tissue infection by a B-cell-tropic rhadinovirus.

    Science.gov (United States)

    Chao, Brittany; Frederico, Bruno; Stevenson, Philip G

    2015-09-01

    Lymphocytes provide gammaherpesviruses with a self-renewing substrate for persistent infection and with transport to mucosal sites for host exit. Their role in the initial colonization of new hosts is less clear. Murid herpesvirus 4 (MuHV-4), an experimentally accessible, B-cell-tropic rhadinovirus (gamma-2 herpesvirus), persistently infects both immunocompetent and B-cell-deficient mice. A lack of B-cells did not compromise MuHV-4 entry into lymphoid tissue, which involved myeloid cell infection. However, it impaired infection amplification and MuHV-4 exit from lymphoid tissue, which involved myeloid to B-cell transfer.

  7. Human Capital and Economic Growth - How Strong is the Nexus?

    Directory of Open Access Journals (Sweden)

    Marinko Škare

    2016-08-01

    Full Text Available The link between human capital and economic growth still remains unexplained because of the measurement issues connected to the human capital stock. This study investigates the link between human capital stock and economic growth using inclusive wealth index and ratio of engaged to actively disengaged employees as proxy for human capital stock. Data from the global workplace and inclusive wealth reports are used in order to provide an international comparison of the link between human capital and inclusive wealth. Cross country comparison show human capital largerly contribute to the inclusive wealth formation. Formal education is important but also motivating working environment is needed to achieve sustainable economic growth. The finding further indicates that standard human capital growth model should be revised taking into the account variables addressing sustainable growth (not just growth and environmental variables (work conditions affecting human capital stock. Countries encouraging investments in the development of individuals both through formal education and inspiring work environments achieve higher sustainable economic growth

  8. Novel Function of TNF Cytokines in Regulating Bone Marrow B Cell Survival

    Institute of Scientific and Technical Information of China (English)

    MinZhang; King-HungKo; QueenieLaiKwanLam; CherryKamChunLo; DanielJiaLinXu; LijunShen; BojianZheng; GopeshSrivastava; LiweiLu

    2004-01-01

    Two newly identified tumor necrosis factor (TNF) family cytokines, B cell activation factor from the TNF family (BAFF) and a proliferation-inducing ligand (APRIL), have recently been shown to enhance the maturation and survival of peripheral B cells. However, whether BAFF and APRIL are expressed in the bone marrow (BM) microenvironment and if these two cytokines modulate early B cell development remain unclear.In the present study, we have detected the abundant expression of BAFF and APRIL transcripts in BM non-lymphoid cells. Low levels of BAFF and APRIL mRNA are also found in developing B cells. Furthermore,we have determined the expression patterns of BAFF receptors during B lymphopoiesis. In cultures, both recombinant BAFF and APRIL significantly promote the survival of precursor B cells whereas only BAFF can suppress apoptosis of immature B cells. These findings suggest that BAFF and APRIL, in addition to their well established role in regulating peripheral B cell growth, can modulate the survival of developing B cells in the BM. Cellular & Molecular Immunology. 2004;1(6):447-453.

  9. [Human growth hormone and Turner syndrome].

    Science.gov (United States)

    Sánchez Marco, Silvia Beatriz; de Arriba Muñoz, Antonio; Ferrer Lozano, Marta; Labarta Aizpún, José Ignacio; Garagorri Otero, Jesús María

    2017-02-01

    The evaluation of clinical and analytical parameters as predictors of the final growth response in Turner syndrome patients treated with growth hormone. A retrospective study was performed on 25 girls with Turner syndrome (17 treated with growth hormone), followed-up until adult height. Auxological, analytical, genetic and pharmacological parameters were collected. A descriptive and analytical study was conducted to evaluate short (12 months) and long term response to treatment with growth hormone. A favourable treatment response was shown during the first year of treatment in terms of height velocity gain in 66.6% of cases (height-gain velocity >3cm/year). A favourable long-term treatment response was also observed in terms of adult height, which increased by 42.82±21.23cm (1.25±0.76 SDS), with an adult height gain of 9.59±5.39cm (1.68±1.51 SDS). Predictors of good response to growth hormone treatment are: A) initial growth hormone dose, B) time on growth hormone treatment until starting oestrogen therapy, C) increased IGF1 and IGFBP-3 levels in the first year of treatment, and D) height gain velocity in the first year of treatment. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Multiphasic growth models and the evolution of prolonged growth exemplified by human brain evolution.

    Science.gov (United States)

    Vrba, E S

    1998-02-07

    New models for multiphasic growth are presented. They are illustrated by analysis of brain growth in humans and chimpanzees, and the results are used to test the hypothesis of evolution by proportional growth prolongation: that all descendant growth phases are extended by the same factor while each remains at the ancestral growth rate. The results are consistent with the hypothesis and imply that gross brain weight increase towards humans required change in only one growth parameter: prolongation of the nonlinear ancestral growth phases. The restricted and orderly nature of the developmental changes hints at a basis in few genetic changes. Proportional growth prolongation is of general evolutionary importance because it can reorganize body proportions.

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

    Directory of Open Access Journals (Sweden)

    Emmanuelle Dugas-Bourdages

    2014-01-01

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

  12. Non-invasive bioluminescence imaging to monitor the immunological control of a plasmablastic lymphoma-like B cell neoplasia after hematopoietic cell transplantation.

    Directory of Open Access Journals (Sweden)

    Martin Chopra

    Full Text Available To promote cancer research and to develop innovative therapies, refined pre-clinical mouse tumor models that mimic the actual disease in humans are of dire need. A number of neoplasms along the B cell lineage are commonly initiated by a translocation recombining c-myc with the immunoglobulin heavy-chain gene locus. The translocation is modeled in the C.129S1-Igha(tm1(MycJanz/J mouse which has been previously engineered to express c-myc under the control of the endogenous IgH promoter. This transgenic mouse exhibits B cell hyperplasia and develops diverse B cell tumors. We have isolated tumor cells from the spleen of a C.129S1-Igha(tm1(MycJanz/J mouse that spontaneously developed a plasmablastic lymphoma-like disease. These cells were cultured, transduced to express eGFP and firefly luciferase, and gave rise to a highly aggressive, transplantable B cell lymphoma cell line, termed IM380. This model bears several advantages over other models as it is genetically induced and mimics the translocation that is detectable in a number of human B cell lymphomas. The growth of the tumor cells, their dissemination, and response to treatment within immunocompetent hosts can be imaged non-invasively in vivo due to their expression of firefly luciferase. IM380 cells are radioresistant in vivo and mice with established tumors can be allogeneically transplanted to analyze graft-versus-tumor effects of transplanted T cells. Allogeneic hematopoietic stem cell transplantation of tumor-bearing mice results in prolonged survival. These traits make the IM380 model very valuable for the study of B cell lymphoma pathophysiology and for the development of innovative cancer therapies.

  13. Transcription factor ABF-1 suppresses plasma cell differentiation but facilitates memory B cell formation.

    Science.gov (United States)

    Chiu, Yi-Kai; Lin, I-Ying; Su, Shin-Tang; Wang, Kuan-Hsiung; Yang, Shii-Yi; Tsai, Dong-Yan; Hsieh, Yi-Ting; Lin, Kuo-I

    2014-09-01

    Ag-primed B cells that result from an immune response can form either memory B cells or Ab-secreting plasma cells; however, the molecular machinery that controls this cellular fate is poorly understood. In this study, we show that activated B cell factor-1 (ABF-1), which encodes a basic helix-loop-helix transcriptional repressor, participates in this regulation. ABF-1 was prevalently expressed in purified memory B cells and induced by T follicular helper cell-mediated signals. ABF-1 expression declined by the direct repression of B lymphocyte-induced maturation protein-1 during differentiation. Ectopic expression of ABF-1 reduced the formation of Ab-secreting cells in an in vitro differentiation system of human memory B cells. Accordingly, knockdown of ABF-1 potentiates the formation of Ab-secreting cells. A transgenic mouse that expresses inducible ABF-1 in a B cell-specific manner was generated to demonstrate that the formation of germinal center and memory B cells was augmented by induced ABF-1 in an immune response, whereas the Ag-specific plasma cell response was dampened. This effect was associated with the ability of ABF-1 to limit cell proliferation. Together, our results demonstrate that ABF-1 facilitates formation of memory B cells but prevents plasma cell differentiation.

  14. B-cell-targeted therapy for systemic lupus erythematosus: an update.

    Science.gov (United States)

    Ding, Changhai; Foote, Simon; Jones, Graeme

    2008-01-01

    Systemic lupus erythematosus (SLE) is a classic autoimmune disease characterized by a myriad of immune system aberrations, most likely resulting from pathogenic autoantibody production, immune complex deposition, and subsequent end-organ damage. B cells play a key role in the pathogenesis; therefore, B-cell-targeted therapies, including B-cell depletion and blockage of B-cell survival factors such as B-lymphocyte stimulator (BLyS), are potential therapeutic targets for SLE. In uncontrolled clinical trials from approximately 20 studies, rituximab--a mouse-human chimeric anti-CD20 monoclonal antibody that effectively depletes B cells--has been demonstrated to reduce disease activity and decrease serum autoantibodies, with a clinical response of 86% in a case series of approximately 400 SLE patients with refractory disease, with or without concomitant use of cyclophosphamide. Epratuzumab, a humanized anti-CD22 monoclonal antibody that partially depletes B cells, has also been shown to reduce disease activity but not to decrease autoantibody levels in patients with moderately active SLE. Randomized controlled phase I/II trials in patients with active SLE have documented that belimumab, a humanized anti-BLyS monoclonal antibody, reduces B-cell numbers, inhibits disease activity and decreases anti-double-stranded DNA autoantibody in SLE patients. All these therapies are well tolerated, but accompanying infectious complications have been observed. Other B-cell-targeted therapies such as 'humanized' monoclonal antibodies to CD20 (e.g. ocrelizumab) and agents that interrupt B-cell/T-cell interactions also have potential, and the efficacy of these, along with rituximab, belimumab and epratuzumab, needs to be determined by randomized controlled trials.

  15. PPARγ activation inhibits growth and survival of human endometriotic cells by suppressing estrogen biosynthesis and PGE2 signaling.

    Science.gov (United States)

    Lebovic, Dan I; Kavoussi, Shahryar K; Lee, JeHoon; Banu, Sakhila K; Arosh, Joe A

    2013-12-01

    Endometriosis is a chronic inflammatory disease of reproductive age women leading to chronic pelvic pain and infertility. Current antiestrogen therapies are temporizing measures, and endometriosis often recurs. Potential nonestrogenic or nonsteroidal targets are needed for treating endometriosis. Peroxisome proliferator-activated receptor (PPAR)γ, a nuclear receptor, is activated by thiazolidinediones (TZDs). In experimental endometriosis, TZDs inhibit growth of endometriosis. Clinical data suggest potential use of TZDs for treating pain and fertility concurrently in endometriosis patients. Study objectives were to 1) determine the effects of PPARγ action on growth and survival of human endometriotic epithelial and stromal cells and 2) identify the underlying molecular links between PPARγ activation and cell cycle regulation, apoptosis, estrogen biosynthesis, and prostaglandin E2 biosynthesis and signaling in human endometriotic epithelial and stromal cells. Results indicate that activation of PPARγ by TZD ciglitazone 1) inhibits growth of endometriotic epithelial cells 12Z up to 35% and growth of endometriotic stromal cells 22B up to 70% through altered cell cycle regulation and intrinsic apoptosis, 2) decreases expression of PGE2 receptors (EP)2 and EP4 mRNAs in 12Z and 22B cells, and 3) inhibits expression and function of P450 aromatase mRNA and protein and estrone production in 12Z and 22B cells through EP2 and EP4 in a stromal-epithelial cell-specific manner. Collectively, these results indicate that PGE2 receptors EP2 and EP4 mediate actions of PPARγ by incorporating multiple cell signaling pathways. Activation of PPARγ combined with inhibition of EP2 and EP4 may emerge as novel nonsteroidal therapeutic targets for endometriosis-associated pain and infertility, if clinically proven safe and efficacious.

  16. Proliferative activity of a blend of Echinacea angustifolia and Echinacea purpurea root extracts in human vein epithelial, HeLa, and QBC-939 cell lines, but not in Beas-2b cell lines.

    Science.gov (United States)

    Cichello, Simon Angelo; Yao, Qian; He, Xiao Qiong

    2016-04-01

    Echinacea is used for its immunostimulating properties and may have a role in modulating adverse immune effects of chemotherapy (i.e., use of 5-fluorouracil (5-FU); fluorouracil and its immunosuppressive effect). Patients may seek herbal remedies such as Echinacea (Echinacea angustifolia and Echinacea purpurea) for immune stimulation. Echinacea extracts have been prescribed to supplement cancer chemotherapy for their immune-supportive effects; however, the extracts may also influence tumourgenesis. Our study aimed to determine the proliferative effect of the ethanolic blend of E. angustifolia and E. purpurea on various cancer cervical and bile duct cell lines, including HELA and QBC-939. Various cancer cells (HeLa and QBC-939) and human vein epithelial cells (HUVEC) were treated with the Echinacea blend sample that was evaporated and reconstituted in Dimethyl sulfoxide (DMSO). As the extract concentration of Echinacea was increased from 12.5 μg/mL to 25 μg/mL, there was an increase in cell inhibition up to 100%, which then reduced to 90% over the next three concentrations, 50 μg/mL, 100 μg/mL, and 200 μg/mL, in HeLa cells; further inhibitory effects were observed in QBC-939 cells, from 9% inhibition at a concentration of 25 μg/mL up to 37.96% inhibition at 100 μg/mL concentration. Moreover, this is the first study to report the growth-promoting effects of this Echinacea blend in HUVEC, up to 800% at a dose concentration of 200 μg/mL. Previous studies have suggested that chicoric acid of Echinacea spp. is responsible for the increased cell growth. The results of this study show that the hydroethanolic extract of Echinacea herbal medicine promotes the growth of HeLa cells and QBC-939 cancer cell proliferation, and may interfere with cancer treatment (i.e., chemotherapy drugs such as 5-fluorouracil and Cisplatin (DDP)). However, the Echinacea blend shows potential in neurodegenerative diseases with growth-promoting effects in HUVEC. Further animal

  17. Proliferative activity of a blend of Echinacea angustifolia and Echinacea purpurea root extracts in human vein epithelial, HeLa, and QBC-939 cell lines, but not in Beas-2b cell lines

    Directory of Open Access Journals (Sweden)

    Simon Angelo Cichello

    2016-04-01

    Full Text Available Echinacea is used for its immunostimulating properties and may have a role in modulating adverse immune effects of chemotherapy (i.e., use of 5-fluorouracil (5-FU; fluorouracil and its immunosuppressive effect. Patients may seek herbal remedies such as Echinacea (Echinacea angustifolia and Echinacea purpurea for immune stimulation. Echinacea extracts have been prescribed to supplement cancer chemotherapy for their immune-supportive effects; however, the extracts may also influence tumourgenesis. Our study aimed to determine the proliferative effect of the ethanolic blend of E. angustifolia and E. purpurea on various cancer cervical and bile duct cell lines, including HELA and QBC-939. Various cancer cells (HeLa and QBC-939 and human vein epithelial cells (HUVEC were treated with the Echinacea blend sample that was evaporated and reconstituted in Dimethyl sulfoxide (DMSO. As the extract concentration of Echinacea was increased from 12.5 μg/mL to 25 μg/mL, there was an increase in cell inhibition up to 100%, which then reduced to 90% over the next three concentrations, 50 μg/mL, 100 μg/mL, and 200 μg/mL, in HeLa cells; further inhibitory effects were observed in QBC-939 cells, from 9% inhibition at a concentration of 25 μg/mL up to 37.96% inhibition at 100 μg/mL concentration. Moreover, this is the first study to report the growth-promoting effects of this Echinacea blend in HUVEC, up to 800% at a dose concentration of 200 μg/mL. Previous studies have suggested that chicoric acid of Echinacea spp. is responsible for the increased cell growth. The results of this study show that the hydroethanolic extract of Echinacea herbal medicine promotes the growth of HeLa cells and QBC-939 cancer cell proliferation, and may interfere with cancer treatment (i.e., chemotherapy drugs such as 5-fluorouracil and Cisplatin (DDP. However, the Echinacea blend shows potential in neurodegenerative diseases with growth-promoting effects in HUVEC

  18. Pattern of hormone receptors and human epidermal growth factor ...

    African Journals Online (AJOL)

    2015-02-05

    Feb 5, 2015 ... Key words: Breast cancer, human epidermal growth factor receptor 2/neu, immunohistochemistry, ... therapy.[6‑8] Of all these prognostic and predictive factors, ... one of the biggest private medical laboratories in Nigeria.

  19. IL-35-producing B cells are critical regulators of immunity during autoimmune and infectious diseases.

    Science.gov (United States)

    Shen, Ping; Roch, Toralf; Lampropoulou, Vicky; O'Connor, Richard A; Stervbo, Ulrik; Hilgenberg, Ellen; Ries, Stefanie; Dang, Van Duc; Jaimes, Yarúa; Daridon, Capucine; Li, Rui; Jouneau, Luc; Boudinot, Pierre; Wilantri, Siska; Sakwa, Imme; Miyazaki, Yusei; Leech, Melanie D; McPherson, Rhoanne C; Wirtz, Stefan; Neurath, Markus; Hoehlig, Kai; Meinl, Edgar; Grützkau, Andreas; Grün, Joachim R; Horn, Katharina; Kühl, Anja A; Dörner, Thomas; Bar-Or, Amit; Kaufmann, Stefan H E; Anderton, Stephen M; Fillatreau, Simon

    2014-03-20

    B lymphocytes have critical roles as positive and negative regulators of immunity. Their inhibitory function has been associated primarily with interleukin 10 (IL-10) because B-cell-derived IL-10 can protect against autoimmune disease and increase susceptibility to pathogens. Here we identify IL-35-producing B cells as key players in the negative regulation of immunity. Mice in which only B cells did not express IL-35 lost their ability to recover from the T-cell-mediated demyelinating autoimmune disease experimental autoimmune encephalomyelitis (EAE). In contrast, these mice displayed a markedly improved resistance to infection with the intracellular bacterial pathogen Salmonella enterica serovar Typhimurium as shown by their superior containment of the bacterial growth and their prolonged survival after primary infection, and upon secondary challenge, compared to control mice. The increased immunity found in mice lacking IL-35 production by B cells was associated with a higher activation of macrophages and inflammatory T cells, as well as an increased function of B cells as antigen-presenting cells (APCs). During Salmonella infection, IL-35- and IL-10-producing B cells corresponded to two largely distinct sets of surface-IgM(+)CD138(hi)TACI(+)CXCR4(+)CD1d(int)Tim1(int) plasma cells expressing the transcription factor Blimp1 (also known as Prdm1). During EAE, CD138(+) plasma cells were also the main source of B-cell-derived IL-35 and IL-10. Collectively, our data show the importance of IL-35-producing B cells in regulation of immunity and highlight IL-35 production by B cells as a potential therapeutic target for autoimmune and infectious diseases. This study reveals the central role of activated B cells, particularly plasma cells, and their production of cytokines in the regulation of immune responses in health and disease.

  20. Engagement of CD22 on B cells with the monoclonal antibody epratuzumab stimulates the phosphorylation of upstream inhibitory signals of the B cell receptor.

    Science.gov (United States)

    Lumb, Simon; Fleischer, Sarah J; Wiedemann, Annika; Daridon, Capucine; Maloney, Alison; Shock, Anthony; Dörner, Thomas

    2016-06-01

    The binding of antigen to the B cell receptor (BCR) results in a cascade of signalling events that ultimately drive B cell activation. Uncontrolled B cell activation is regulated by negative feedback loops that involve inhibitory co-receptors such as CD22 and CD32B that exert their functions following phosphorylation of immunoreceptor tyrosine-based inhibition motifs (ITIMs). The CD22-targeted antibody epratuzumab has previously been shown to inhibit BCR-driven signalling events, but its effects on ITIM phosphorylation of CD22 and CD32B have not been properly evaluated. The present study therefore employed both immunoprecipitation and flow cytometry approaches to elucidate the effects of epratuzumab on direct phosphorylation of key tyrosine (Tyr) residues on both these proteins, using both transformed B cell lines and primary human B cells. Epratuzumab induced the phosphorylation of Tyr(822) on CD22 and enhanced its co-localisation with SHP-1. Additionally, in spite of high basal phosphorylation of other key ITIMs on CD22, in primary human B cells epratuzumab also enhanced phosphorylation of Tyr(807), a residue involved in the recruitment of Grb2. Such initiation events could explain the effects of epratuzumab on downstream signalling in B cells. Finally, we were able to demonstrate that epratuzumab stimulated the phosphorylation of Tyr(292) on the low affinity inhibitory Fc receptor CD32B which would further attenuate BCR-induced signalling. Together, these data demonstrate that engagement of CD22 with epratuzumab leads to the direct phosphorylation of key upstream inhibitory receptors of BCR signalling and may help to explain how this antibody modulates B cell function.

  1. Human Capital, Population Growth and Economic Development: Beyond Correlations

    OpenAIRE

    Rosenzweig, Mark R.

    1987-01-01

    Empirical evidence on three assertions commonly-made by population policy advocates about the relationships among population growth, human capital formation and economic development is discussed and evaluated in the light of economic-biological models of household behavior and of its relevance to population policy. The three assertions are that (a) population growth and human capital investments jointly reflect and respond to changes in the economic environment, (b) larger families directly i...

  2. Phenotypic and functional characteristics of human newborns' B lymphocytes.

    Science.gov (United States)

    Durandy, A; Thuillier, L; Forveille, M; Fischer, A

    1990-01-01

    It has been demonstrated two major facts concerning human newborns' B lymphocytes: 1) they differentiate poorly into Ig-producing cells and 2) they express CD5 and CD1c membrane proteins. We have further analyzed human newborns' B cell characteristics and found that approximately half of them express activation Ag, i.e., 4F2 and IL-2R, both associated in significant proportions with CD23 and Bac-1. These membrane Ag were found both on CD5(+) and CD5(-) B cells. Newborns' B cells do not exhibit other activation markers because they express surface IgD, and because their size, RNA, and DNA contents do not differ from those of adults' B cells, indicating that they are in the G0/G1 cell cycle phase. Newborns' B cell proliferation can be induced by rIL-2, rIL-4, low m.w. B cell growth factor, and by Staphylococcus aureus protein A. It is presently difficult to build a hypothesis accounting for all the specific findings made on newborns' B cells. It is not known for instance whether CD5(+) and (-) B cells belong to distinct subsets as suggested by the fluorescence intensity curve obtained with an anti-CD5 antibody or to distinct stages in a unique pattern of B cell maturation during fetal and newborn life. This may indicate that partially activated B cells actually produce natural polyspecific autoantibodies of the IgM isotype found in newborns' human serum.

  3. Population growth and human capital: a welfarist approach

    OpenAIRE

    Thomas Renstrom; Luca Spataro

    2014-01-01

    In this paper we investigate the relationship between economic and population growth in an endogenous growth model driven by human capital accumulation à la Lucas (1988). Since we allow for endogenous population growth, we adopt the population criterion Relative Critical Level Utilitarianism (an extension of Critical Level Utilitarianism, Blackorby et al. 1995) which allows axiomatically founded welfare orderings under variable population. Under this extension the Critical Level Utility is de...

  4. Electrochemical Methods for Human Growth Hormone Doping Detection

    OpenAIRE

    2015-01-01

    Human Growth Hormone (GH) is produced by the anterior pituitary gland and promotes growth of tissue through direct uptake at target tissue sites, or alternatively, by regulating production of insulin-like growth factor-1. The World Anti-Doping Agency considers GH a performance enhancing substance, so the use of GH by athletes is prohibited in most sports. The current immunoassay for GH detection is suboptimal for routine screening of blood samples because of the large resources required for c...

  5. Does Human Capital Contribute to Economic Growth in Mauritius?

    Science.gov (United States)

    Neeliah, Harris; Seetanah, Boopen

    2016-01-01

    Purpose: Real gross domestic product (GDP) growth for Mauritius has averaged more than 5 per cent since 1970 and GDP per capita has increased more than tenfold between 1970 and 2012, from less than $500 to more than $9,000. It has often been reported that human capital, along with other growth enablers, has played an important role in this…

  6. Does Human Capital Contribute to Economic Growth in Mauritius?

    Science.gov (United States)

    Neeliah, Harris; Seetanah, Boopen

    2016-01-01

    Purpose: Real gross domestic product (GDP) growth for Mauritius has averaged more than 5 per cent since 1970 and GDP per capita has increased more than tenfold between 1970 and 2012, from less than $500 to more than $9,000. It has often been reported that human capital, along with other growth enablers, has played an important role in this…

  7. Farnesyl transferase inhibitors induce extended remissions in transgenic mice with mature B cell lymphomas

    Directory of Open Access Journals (Sweden)

    Refaeli Yosef

    2008-05-01

    Full Text Available Abstract Background We have used a mouse model based on overexpression of c-Myc in B cells genetically engineered to be self-reactive to test the hypothesis that farnesyl transferase inhibitors (FTIs can effectively treat mature B cell lymphomas. FTIs are undergoing clinical trials to treat both lymphoid and non-lymphoid malignancies and we wished to obtain evidence to support the inclusion of B cell lymphomas in future trials. Results We report that two FTIs, L-744,832 and SCH66336, blocked the growth of mature B cell lymphoma cells in vitro and in vivo. The FTI treatment affected the proliferation and survival of the transformed B cells to a greater extent than naïve B cells stimulated with antigen. In syngeneic mice transplanted with the transgenic lymphoma cells, L-744,832 treatment prevented the growth of the tumor cells and the morbidity associated with the resulting lymphoma progression. Tumors that arose from transplantation of the lymphoma cells regressed with as little as three days of treatment with L-744,832 or SCH66336. Treatment of these established lymphomas with L-744,832 for seven days led to long-term remission of the disease in approximately 25% of animals. Conclusion FTI treatment can block the proliferation and survival of self-reactive transformed B cells that overexpress Myc. In mice transplanted with mature B cell lymphomas, we found that FTI treatment led to regression of disease. FTIs warrant further consideration as therapeutic agents for mature B cell lymphomas and other lymphoid tumors.

  8. The Pre-B Cell Receptor and Its Function during B Cell Development

    Institute of Scientific and Technical Information of China (English)

    MinZhang; GopeshSrivastava; LiweiLu

    2004-01-01

    The process of B cell development in the bone marrow occurs by the stepwise rearrangements of the V, D, and J segments of the Ig H and L chain gene loci. During early B cell genesis, productive IgH chain gene rearrangement leads to assembly of the pre-B cell receptor (pre-BCR), which acts as an important checkpoint at the pro-B/preB transitional stage. The pre-BCR, transiently expressed by developing precursor B cells, comprises the Ig μH chain, surrogate light (SL) chains VpreB and λ5, as well as the signal-transducing hetero-dimer Igα/Igβ. Signaling through the pre-BCR regulates allelic exclusion at the Ig H locus, stimulates cell proliferation, and induces differentiation to small post-mitotic pre-B cells that further undergo the rearrangement of the IgL chain genes. Recent advances in elucidating the key roles of pre-BCR in B cell development have provided a better understanding of normal B lymphopoiesis and its dysregulated state leading to B cell neoplasia. Cellular & Molecular Immunology. 2004;1(2):89-94.

  9. The Pre-B Cell Receptor and Its Function during B Cell Development

    Institute of Scientific and Technical Information of China (English)

    Min Zhang; Gopesh Srivastava1; Liwei Lu

    2004-01-01

    The process of B cell development in the bone marrow occurs by the stepwise rearrangements of the V, D, and Jsegments of the Ig H and L chain gene loci. During early B cell genesis, productive IgH chain generearrangement leads to assembly of the pre-B cell receptor (pre-BCR), which acts as an important checkpointat the pro-B/preB transitional stage. The pre-BCR, transiently expressed by developing precursor B cells,comprises the Ig μH chain, surrogate light (SL) chains VpreB and λ5, as well as the signal-transducing heterodimer Igα/Igβ. Signaling through the pre-BCR regulates allelic exclusion at the Ig H locus, stimulates cell proliferation, and induces differentiation to small post-mitotic pre-B cells that further undergo the rearrangement of the IgL chain genes. Recent advances in elucidating the key roles of pre-BCR in B cell development have provided a better understanding of normal B lymphopoiesis and its dysregulated state leading to B cell neoplasia.

  10. B cells in the Multiple Sclerosis Central Nervous System: Trafficking and contribution to CNS-compartmentalized inflammation

    Directory of Open Access Journals (Sweden)

    Laure eMichel

    2015-12-01

    Full Text Available Clinical trial results of peripheral B cell depletion indicate abnormal pro-inflammatory B cell properties, and particularly antibody-independent functions, contribute to relapsing MS disease activity. However, potential roles of B cells in progressive forms of disease continue to be debated. Prior work indicates that presence of B cells is fostered within the inflamed MS central nervous system (CNS environment, and that B cell-rich immune-cell collections may be present within the meninges of patients. A potential association is reported between such meningeal immune-cell collections and the sub-pial pattern of cortical injury that is now considered important in progressive disease. Elucidating the characteristics of B cells that populate the MS CNS, how they traffic into the CNS and how they may contribute to progressive forms of the disease has become of considerable interest. Here, we will review characteristics of human B cells identified within distinct CNS sub-compartments of patients with MS, including the cerebrospinal fluid (CSF, parenchymal lesions and meninges, as well as the relationship between B cell populations identified in these sub-compartments and the periphery. We will further describe the different barriers of the CNS and the possible mechanisms of migration of B cells across these barriers. Finally, we will consider the range of human B cell responses (including potential for antibody production, cytokine secretion and antigen presentation that may contribute to propagating inflammation and injury cascades thought to underlie MS progression.

  11. Bryostatin-1, Fenretinide and 1α,25 (OH)2D3 Induce Growth Inhibition, Apoptosis and Differentiation in T and B Cell-Derived Acute Lymphoblastic Leukemia Cell Lines (CCRF-CEM and Nalm-6)

    Science.gov (United States)

    Ardekani, Ali M.; Fard, Shahrzad Soleymani; Jeddi-Tehrani, Mahmood; Ghahremanzade, Ramin

    2011-01-01

    In many acute leukemias, normal differentiation does not occur. However, in many cell lines derived from hematologic malignancies, differentiation or apoptosis can be induced by variety of agents. Despite advances in the treatment of Acute Lymphoblastic Leukemia (ALL), in most patients long-term survival rates remain unsatisfactory, especially in T-cell derived ALL. Thus we studied the anti-cancer effects of fenretinide, 1α,25(OH)2D3, and bryostatin-1 in CCRF-CEM (T-cell derived) and Nalm-6 (B-cell derived) ALL cell lines. Using MTT assays, both cell lines were shown to exhibit increased inhibition of proliferation at micro (fenretinide) and nanomolar (1α,25(OH)2D3, bryostatin-1) concentrations. These anti-cancer agents were shown to induce apoptosis and activate caspase-3 pathway in both ALL cell lines. Furthermore, for the first time we are reporting consistent anti-proliferative and apoptotic effects of Bryostatin-1 in ALL T-cell derived cell line with the lowest ED50 (ranging 4.6-7.4 nM). To evaluate the differentiation induction by fenretinide, 1α,25(OH)2D3, and bryostatin-1 in ALL cell lines, we assayed for the expressions of CD19, CD38 markers on Nalm-6 and CD7 marker on CCRF-CEM cell line. The flow cytometric analysis showed a significant increase in expression of CD markers in response to anti-cancer drug treatments. To assay the effects of anti-cancer drugs on cell cycle distribution, cell cycle analysis using flow cytometry was employed. These anti-cancer drugs appear to affect the CCRF-CEM and Nalm-6 cell cycles differently (G0/G1 and G2/M arrest, respectively). Overall results demonstrate that the anti-cancer agents used in this study are strong inhibitors of ALL cell proliferation and inducers of apoptosis and differentiation in vitro. These findings may be quite helpful if these drugs are to be used for differentiation therapy of ALL patients in clinics in the future. Further studies are warranted to establish the in vivo effect of these drugs

  12. Bryostatin-1, Fenretinide and 1α,25 (OH)(2)D(3) Induce Growth Inhibition, Apoptosis and Differentiation in T and B Cell-Derived Acute Lymphoblastic Leukemia Cell Lines (CCRF-CEM and Nalm-6).

    Science.gov (United States)

    Ardekani, Ali M; Fard, Shahrzad Soleymani; Jeddi-Tehrani, Mahmood; Ghahremanzade, Ramin

    2011-10-01

    In many acute leukemias, normal differentiation does not occur. However, in many cell lines derived from hematologic malignancies, differentiation or apoptosis can be induced by variety of agents. Despite advances in the treatment of Acute Lymphoblastic Leukemia (ALL), in most patients long-term survival rates remain unsatisfactory, especially in T-cell derived ALL. Thus we studied the anti-cancer effects of fenretinide, 1α,25(OH)(2)D(3), and bryostatin-1 in CCRF-CEM (T-cell derived) and Nalm-6 (B-cell derived) ALL cell lines. Using MTT assays, both cell lines were shown to exhibit increased inhibition of proliferation at micro (fenretinide) and nanomolar (1α,25(OH)(2)D(3), bryostatin-1) concentrations. These anti-cancer agents were shown to induce apoptosis and activate caspase-3 pathway in both ALL cell lines. Furthermore, for the first time we are reporting consistent anti-proliferative and apoptotic effects of Bryostatin-1 in ALL T-cell derived cell line with the lowest ED(50) (ranging 4.6-7.4 nM). To evaluate the differentiation induction by fenretinide, 1α,25(OH)(2)D(3), and bryostatin-1 in ALL cell lines, we assayed for the expressions of CD19, CD38 markers on Nalm-6 and CD7 marker on CCRF-CEM cell line. The flow cytometric analysis showed a significant increase in expression of CD markers in response to anti-cancer drug treatments. To assay the effects of anti-cancer drugs on cell cycle distribution, cell cycle analysis using flow cytometry was employed. These anti-cancer drugs appear to affect the CCRF-CEM and Nalm-6 cell cycles differently (G0/G1 and G2/M arrest, respectively). Overall results demonstrate that the anti-cancer agents used in this study are strong inhibitors of ALL cell proliferation and inducers of apoptosis and differentiation in vitro. These findings may be quite helpful if these drugs are to be used for differentiation therapy of ALL patients in clinics in the future. Further studies are warranted to establish the in vivo effect of

  13. B cell activation by outer membrane vesicles--a novel virulence mechanism.

    Science.gov (United States)

    Vidakovics, Maria Laura A Perez; Jendholm, Johan; Mörgelin, Matthias; Månsson, Anne; Larsson, Christer; Cardell, Lars-Olaf; Riesbeck, Kristian

    2010-01-15

    Secretion of outer membrane vesicles (OMV) is an intriguing phenomenon of Gram-negative bacteria and has been suggested to play a role as virulence factors. The respiratory pathogens Moraxella catarrhalis reside in tonsils adjacent to B cells, and we have previously shown that M. catarrhalis induce a T cell independent B cell response by the immunoglobulin (Ig) D-binding superantigen MID. Here we demonstrate that Moraxella are endocytosed and killed by human tonsillar B cells, whereas OMV have the potential to interact and activate B cells leading to bacterial rescue. The B cell response induced by OMV begins with IgD B cell receptor (BCR) clustering and Ca(2+) mobilization followed by BCR internalization. In addition to IgD BCR, TLR9 and TLR2 were found to colocalize in lipid raft motifs after exposure to OMV. Two components of the OMV, i.e., MID and unmethylated CpG-DNA motifs, were found to be critical for B cell activation. OMV containing MID bound to and activated tonsillar CD19(+) IgD(+) lymphocytes resulting in IL-6 and IgM production in addition to increased surface marker density (HLA-DR, CD45, CD64, and CD86), whereas MID-deficient OMV failed to induce B cell activation. DNA associated with OMV induced full B cell activation by signaling through TLR9. Importantly, this concept was verified in vivo, as OMV equipped with MID and DNA were found in a 9-year old patient suffering from Moraxella sinusitis. In conclusion, Moraxella avoid direct interaction with host B cells by redirecting the adaptive humoral immune response using its superantigen-bearing OMV as decoys.

  14. B Cell Activation by Outer Membrane Vesicles—A Novel Virulence Mechanism

    Science.gov (United States)

    Perez Vidakovics, Maria Laura A.; Jendholm, Johan; Mörgelin, Matthias; Månsson, Anne; Larsson, Christer; Cardell, Lars-Olaf; Riesbeck, Kristian

    2010-01-01

    Secretion of outer membrane vesicles (OMV) is an intriguing phenomenon of Gram-negative bacteria and has been suggested to play a role as virulence factors. The respiratory pathogens Moraxella catarrhalis reside in tonsils adjacent to B cells, and we have previously shown that M. catarrhalis induce a T cell independent B cell response by the immunoglobulin (Ig) D-binding superantigen MID. Here we demonstrate that Moraxella are endocytosed and killed by human tonsillar B cells, whereas OMV have the potential to interact and activate B cells leading to bacterial rescue. The B cell response induced by OMV begins with IgD B cell receptor (BCR) clustering and Ca2+ mobilization followed by BCR internalization. In addition to IgD BCR, TLR9 and TLR2 were found to colocalize in lipid raft motifs after exposure to OMV. Two components of the OMV, i.e., MID and unmethylated CpG-DNA motifs, were found to be critical for B cell activation. OMV containing MID bound to and activated tonsillar CD19+ IgD+ lymphocytes resulting in IL-6 and IgM production in addition to increased surface marker density (HLA-DR, CD45, CD64, and CD86), whereas MID-deficient OMV failed to induce B cell activation. DNA associated with OMV induced full B cell activation by signaling through TLR9. Importantly, this concept was verified in vivo, as OMV equipped with MID and DNA were found in a 9-year old patient suffering from Moraxella sinusitis. In conclusion, Moraxella avoid direct interaction with host B cells by redirecting the adaptive humoral immune response using its superantigen-bearing OMV as decoys. PMID:20090836

  15. B cell activation by outer membrane vesicles--a novel virulence mechanism.

    Directory of Open Access Journals (Sweden)

    Maria Laura A Perez Vidakovics

    2010-01-01

    Full Text Available Secretion of outer membrane vesicles (OMV is an intriguing phenomenon of Gram-negative bacteria and has been suggested to play a role as virulence factors. The respiratory pathogens Moraxella catarrhalis reside in tonsils adjacent to B cells, and we have previously shown that M. catarrhalis induce a T cell independent B cell response by the immunoglobulin (Ig D-binding superantigen MID. Here we demonstrate that Moraxella are endocytosed and killed by human tonsillar B cells, whereas OMV have the potential to interact and activate B cells leading to bacterial rescue. The B cell response induced by OMV begins with IgD B cell receptor (BCR clustering and Ca(2+ mobilization followed by BCR internalization. In addition to IgD BCR, TLR9 and TLR2 were found to colocalize in lipid raft motifs after exposure to OMV. Two components of the OMV, i.e., MID and unmethylated CpG-DNA motifs, were found to be critical for B cell activation. OMV containing MID bound to and activated tonsillar CD19(+ IgD(+ lymphocytes resulting in IL-6 and IgM production in addition to increased surface marker density (HLA-DR, CD45, CD64, and CD86, whereas MID-deficient OMV failed to induce B cell activation. DNA associated with OMV induced full B cell activation by signaling through TLR9. Importantly, this concept was verified in vivo, as OMV equipped with MID and DNA were found in a 9-year old patient suffering from Moraxella sinusitis. In conclusion, Moraxella avoid direct interaction with host B cells by redirecting the adaptive humoral immune response using its superantigen-bearing OMV as decoys.

  16. Aging-dependent decline of IL-10 producing B cells coincides with production of antinuclear antibodies but not rheumatoid factors.

    Science.gov (United States)

    van der Geest, Kornelis S M; Lorencetti, Pedro G; Abdulahad, Wayel H; Horst, Gerda; Huitema, Minke; Roozendaal, Caroline; Kroesen, Bart-Jan; Brouwer, Elisabeth; Boots, Annemieke M H

    2016-03-01

    Aging is associated with development of autoimmunity. Loss of B cell tolerance in the elderly is suggested by an increased prevalence of anti-nuclear antibodies (ANAs) and rheumatoid factors (RFs). Accumulating evidence indicates that B cells also impact autoimmunity via secretion of cytokines. So far, few studies have directly assessed the effect of aging on the latter B cell function. Here, we determined if and how human aging influences the production of cytokines by B cells. In a cross-sectional study, we found that absolute numbers of circulating B cells were similar in 31 young (ages 19-39) and 73 old (age ≥ 60) individuals. Numbers of transitional B cells (CD19(+)CD27(-)CD38(High)CD24(High)) were decreased in old individuals, whereas numbers of naive and memory B cell subsets were comparable in young and old individuals. Short-term in vitro stimulation of whole blood samples revealed that numbers of B cells capable of producing TNF-α were similar in young and old individuals. In contrast, B cells capable of IL-10 production were decreased in old subjects. This decline of IL-10(+) B cells was observed in old individuals that were ANA positive, and in those that were negative for both ANAs and RFs. However, IL-10(+) B cells were remarkably well retained in the circulation of old subjects that were RF positive. Thus, pro-inflammatory TNF-α(+) B cells are retained in the elderly, whereas IL-10(+) B cells generally decline. In addition, our findings indicate that IL-10(+) B cells may differentially impact the development of ANAs and RFs in the elderly.

  17. 21 CFR 862.1370 - Human growth hormone test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Human growth hormone test system. 862.1370 Section 862.1370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

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

    Science.gov (United States)

    Pang, S H M; Minnich, M; Gangatirkar, P; Zheng, Z; Ebert, A; Song, G; Dickins, R A; Corcoran, L M; Mullighan, C G; Busslinger, M; Huntington, N D; Nutt, S L; Carotta, S

    2016-06-01

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

  19. Autocrine growth regulation of human glomerular mesangial cells is primarily mediated by basic fibroblast growth factor.

    OpenAIRE

    Francki, A.; Uciechowski, P.; Floege, J; von der Ohe, J.; Resch, K.; Radeke, H. H.

    1995-01-01

    For various forms of human glomerulonephritis a close relationship between inflammatory injury and a local mesangial proliferative response has been described. Herein, we used primary cultures of human glomerular mesangial cells (HMCs) from five different donors to determine the autocrine growth-inducing capacity of their supernatants after stimulation with different cytokines and lipopolysaccharide (LPS) to determine whether this effect is due to basic fibroblast growth factor (bFGF). The ba...

  20. Essential role of MALT1 protease activity in activated B cell-like diffuse large B-cell lymphoma.

    Science.gov (United States)

    Hailfinger, Stephan; Lenz, Georg; Ngo, Vu; Posvitz-Fejfar, Anita; Rebeaud, Fabien; Guzzardi, Montserrat; Penas, Eva-Maria Murga; Dierlamm, Judith; Chan, Wing C; Staudt, Louis M; Thome, Margot

    2009-11-24

    A key element for the development of suitable anti-cancer drugs is the identification of cancer-specific enzymatic activities that can be therapeutically targeted. Mucosa-associated lymphoid tissue transformation protein 1 (MALT1) is a proto-oncogene that contributes to tumorigenesis in diffuse large B-cell lymphoma (DLBCL) of the activated B-cell (ABC) subtype, the least curable subtype of DLBCL. Recent data suggest that MALT1 has proteolytic activity, but it is unknown whether this activity is relevant for tumor growth. Here we report that MALT1 is constitutively active in DLBCL lines of the ABC but not the GCB subtype. Inhibition of the MALT1 proteolytic activity led to reduced expression of growth factors and apoptosis inhibitors, and specifically affected the growth and survival of ABC DLBCL lines. These results demonstrate a key role for the proteolytic activity of MALT1 in DLBCL of the ABC subtype, and provide a rationale for the development of pharmacological inhibitors of MALT1 in DLBCL therapy.

  1. Bim regulates B-cell receptor-mediated apoptosis in the presence of CD40 signaling in CD40-pre-activated splenic B cells differentiating into plasma cells.

    Science.gov (United States)

    Gao, Yuanyuan; Kazama, Hirotaka; Yonehara, Shin

    2012-05-01

    B-cell receptor (BCR)-mediated apoptosis is critical for B-cell development and homeostasis. CD40 signaling has been shown to protect immature or mature B cells from BCR-mediated apoptosis. In this study, to understand the fate of CD40-pre-activated splenic B cells stimulated by BCR engagement in the presence of CD40 signaling, murine splenic B cells were cultured with anti-Igκ and anti-CD40 antibodies after pre-activation with anti-CD40 antibody. We found that apoptosis was induced in the cultured B cells even in the presence of CD40 signaling during the 3-4 days cultivation. We detected up-regulation of Bim expression followed by Bax activation in this apoptotic process and cessation of the apoptosis in Bim-deficient B cells, indicating that Bim is a key regulator of the BCR-mediated apoptosis in the presence of CD40 signaling in CD40-pre-activated B cells. Importantly, this BCR-mediated apoptosis in CD40-pre-activated B cells was shown to be induced at the initiation of plasma cell differentiation at around the preplasmablast stage, and Bim-deficient B cells cultured under these conditions differentiated into plasma cells. Additionally, transforming growth factor-β was found to protect CD40-pre-activated B cells from BCR-mediated apoptosis in the presence of CD40 signaling. Our identified BCR-mediated apoptosis, which is unpreventable by CD40 signaling, suggests a potential mechanism that regulates the elimination of peripheral B cells, which should be derived from nonspecific T-dependent activation of bystander B cells and continuous stimulation with antigens including self-antigens in the presence of T cell help through CD40.

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

    Science.gov (United States)

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

    2017-01-01

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

  3. CD80 expression on B cells regulates murine T follicular helper development, germinal center B cell survival, and plasma cell generation.