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Sample records for b-cell regulatory molecule

  1. Impaired regulatory B cells in myasthenia gravis.

    Science.gov (United States)

    Sheng, Jian Rong; Rezania, Kourosh; Soliven, Betty

    2016-08-15

    Regulatory B cells (Bregs) attenuate the severity of experimental autoimmune myasthenia gravis (EAMG) in an interleukin-10 (IL-10)-dependent manner. The goal of this study was to investigate the role of human Bregs in MG focusing on CD19(+)CD1d(hi) CD5(+) and CD19(+)CD24(hi)CD38(hi) subsets. We found that MG patients exhibited a decrease in the frequency of both Breg subsets and IL-10 producing B cells within each subset, which correlated with disease severity. In addition, there was impaired suppression of Th1 polarization in MG. These findings, taken together with EAMG data, indicate that Bregs play an important role in regulating the severity of MG. PMID:27397074

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

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

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

  3. CNS accumulation of regulatory B cells is VLA-4-dependent

    Science.gov (United States)

    Lehmann-Horn, Klaus; Sagan, Sharon A.; Winger, Ryan C.; Spencer, Collin M.; Bernard, Claude C.A.; Sobel, Raymond A.

    2016-01-01

    Objective: To investigate the role of very late antigen-4 (VLA-4) on regulatory B cells (Breg) in CNS autoimmune disease. Methods: Experimental autoimmune encephalomyelitis (EAE) was induced in mice selectively deficient for VLA-4 on B cells (CD19cre/α4f/f) by immunization with myelin oligodendrocyte glycoprotein (MOG) peptide (p)35–55 or recombinant human (rh) MOG protein. B-cell and T-cell populations were examined by flow cytometry and immunohistochemistry. Breg were evaluated by intracellular IL-10 staining of B cells and, secondly, by coexpression of CD1d and CD5. Results: As previously reported, EAE was less severe in B-cell VLA-4-deficient vs control CD19cre mice when induced by rhMOG, a model that is B-cell-dependent and leads to efficient B-cell activation and antibody production. Paradoxically, B-cell VLA-4-deficient mice developed more severe clinical disease than control mice when EAE was induced with MOG p35-55, a B-cell-independent encephalitogen that does not efficiently activate B cells. Peripheral T-cell and humoral immune responses were not altered in B-cell VLA-4-deficient mice. In MOG p35-55-induced EAE, B-cell VLA-4 deficiency reduced CNS accumulation of B but not T cells. Breg were detected in the CNS of control mice with MOG p35-55-induced EAE. However, more severe EAE in B-cell VLA-4-deficient mice was associated with virtual absence of CNS Breg. Conclusions: Our results demonstrate that CNS accumulation of Breg is VLA-4-dependent and suggest that Breg may contribute to regulation of CNS autoimmunity in situ. These observations underscore the need to choose the appropriate encephalitogen when studying how B cells contribute to pathogenesis or regulation of CNS autoimmunity. PMID:27027096

  4. The regulatory role of B cells in autoimmunity, infections and cancer: Perspectives beyond IL10 production.

    Science.gov (United States)

    Gorosito Serrán, Melisa; Fiocca Vernengo, Facundo; Beccaria, Cristian G; Acosta Rodriguez, Eva V; Montes, Carolina L; Gruppi, Adriana

    2015-11-14

    The term regulatory B cells (B regs) is ascribed to a heterogeneous population of B cells with the function of suppressing inflammatory responses. They have been described mainly during the last decade in the context of different immune-mediated diseases. Most of the work on B regs has been focused on IL-10-producing B cells. However, B cells can exert regulatory functions independently of IL-10 production. Here we discuss the phenotypes, development and effector mechanisms of B regs and advances in their role in autoimmunity, infections and cancer. PMID:26424657

  5. 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.

  6. Systemic Sclerosis Patients Present Alterations in the Expression of Molecules Involved in B-Cell Regulation

    Science.gov (United States)

    Soto, Lilian; Ferrier, Ashley; Aravena, Octavio; Fonseca, Elianet; Berendsen, Jorge; Biere, Andrea; Bueno, Daniel; Ramos, Verónica; Aguillón, Juan Carlos; Catalán, Diego

    2015-01-01

    The activation threshold of B cells is tightly regulated by an array of inhibitory and activator receptors in such a way that disturbances in their expression can lead to the appearance of autoimmunity. The aim of this study was to evaluate the expression of activating and inhibitory molecules involved in the modulation of B cell functions in transitional, naive, and memory B-cell subpopulations from systemic sclerosis patients. To achieve this, blood samples were drawn from 31 systemic sclerosis patients and 53 healthy individuals. Surface expression of CD86, MHC II, CD19, CD21, CD40, CD22, Siglec 10, CD35, and FcγRIIB was determined by flow cytometry. IL-10 production was evaluated by intracellular flow cytometry from isolated B cells. Soluble IL-6 and IL-10 levels were measured by ELISA from supernatants of stimulated B cells. Systemic sclerosis patients exhibit an increased frequency of transitional and naive B cells related to memory B cells compared with healthy controls. Transitional and naive B cells from patients express higher levels of CD86 and FcγRIIB than healthy donors. Also, B cells from patients show high expression of CD19 and CD40, whereas memory cells from systemic sclerosis patients show reduced expression of CD35. CD19 and CD35 expression levels associate with different autoantibody profiles. IL-10+ B cells and secreted levels of IL-10 were markedly reduced in patients. In conclusion, systemic sclerosis patients show alterations in the expression of molecules involved in B-cell regulation. These abnormalities may be determinant in the B-cell hyperactivation observed in systemic sclerosis. PMID:26483788

  7. The role of regulatory B cells (Bregs) in the Tregs-amplifying effect of Sirolimus.

    Science.gov (United States)

    Song, Jiyong; Xiao, Li; Du, Guosheng; Gao, Yu; Chen, Wen; Yang, Shaozhen; Fan, Wenmei; Shi, Bingyi

    2016-09-01

    Sirolimus can significantly amplify regulatory T cells (Tregs) in vivo and in vitro, but the specific mechanism of this has not been well documented. The role of regulatory B cells (Bregs) in the Tregs-amplifying effect of Sirolimus was investigated in peripheral blood mononuclear cells (PBMCs) in vitro in this study. The results showed that the percentages of both CD19+CD24+CD38+TGF-β1+ Bregs and CD19+CD24+CD38+IL-10+ Bregs to B cells were elevated by Sirolimus in PBMCs including B cells. Sirolimus significantly enhances the cytokine production of transforming growth factor-β1 (TGF-β1) and interleukin-10 (IL-10) in PBMCs with B cells, and the enhancement significantly decreased in PBMCs without B cells. The percentage of CD4+CD25+Foxp3+ Tregs to T cells was also elevated by Sirolimus in PBMCs including B cells. The elevation of Tregs percentage decreased in PBMCs without B cells and recovered when additional TGF-β1 and IL-10 were added. The amplification of Tregs by Sirolimus was partially inhibited when either TGF-β1 or IL-10 was neutralized, and it even disappeared when these two cytokines were both neutralized. These results indicate that Sirolimus can amplify Bregs and Tregs in PBMCs in vitro, and Bregs may be the why Sirolimus amplifies Tregs. PMID:27258186

  8. Cutting Edge: Integrin α4 Is Required for Regulatory B Cell Control of Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Glatigny, Simon; Wagner, Catriona A; Bettelli, Estelle

    2016-05-01

    The neutralization of integrin α4 (Itga4) is currently used as treatment in multiple sclerosis. Although most studies have focused on its function on lymphocyte migration to the CNS, we have uncovered the importance of Itga4 for the generation of regulatory B cells in peripheral immune organs and their control of pathogenic T cell response and CNS pathology. Our study underscores the importance of looking at the dual role of B cells in CNS autoimmunity and provides important perspectives regarding the efficacy and side effects associated with Itga4 neutralization and other B cell-targeting therapies. PMID:27016608

  9. TGF-β-Induced Regulatory T Cells Directly Suppress B Cell Responses through a Noncytotoxic Mechanism.

    Science.gov (United States)

    Xu, Anping; Liu, Ya; Chen, Weiqian; Wang, Julie; Xue, Youqiu; Huang, Feng; Rong, Liming; Lin, Jin; Liu, Dahai; Yan, Mei; Li, Quan-Zhen; Li, Bin; Song, Jianxun; Olsen, Nancy; Zheng, Song Guo

    2016-05-01

    Foxp3(+) regulatory T cells (Treg) playing a crucial role in the maintenance of immune tolerance and prevention of autoimmune diseases consist of thymus-derived naturally occurring CD4(+)Foxp3(+) Treg cells (nTreg) and those that can be induced ex vivo with TGF-β (iTreg). Although both Treg subsets share similar phenotypes and functional characteristics, they also have potential biologic differences on their biology. The role of iTreg in regulating B cells remains unclear so far. The suppression assays of Treg subsets on activation, proliferation, and Abs production of B cells were measured using a Treg and B cell coculture system in vitro. Transwell and Ab blockade experiments were performed to assess the roles of cell contact and soluble cytokines. Treg were adoptively transferred to lupus mice to assess in vivo effects on B cells. Like nTreg, iTreg subset also directly suppressed activation and proliferation of B cells. nTreg subset suppressed B cell responses through cytotoxic manner related to expression of granzyme A, granzyme B, and perforin, whereas the role of iTreg subset on B cells did not involve in cytotoxic action but depending on TGF-β signaling. Furthermore, iTreg subset can significantly suppress Ab produced by lupus B cells in vitro. Comparison experiments using autoantibodies microarrays demonstrated that adoptive transfer of iTreg had a superior effect than nTreg subset on suppressing lupus B cell responses in vivo. Our data implicate a role and advantage of iTreg subset in treating B cell-mediated autoimmune diseases, boosting the translational potential of these findings. PMID:27001954

  10. Single molecule analysis of B cell receptor motion during signaling activation

    Science.gov (United States)

    Rey Suarez, Ivan; Koo, Peter; Mochrie, Simon; Song, Wenxia; Upadhyaya, Arpita

    B cells are an essential part of the adaptive immune system. They patrol the body looking for signs of infection in the form of antigen on the surface of antigen presenting cells. The binding of the B cell receptor (BCR) to antigen induces signaling cascades that lead to B cell activation and eventual production of high affinity antibodies. During activation, BCR organize into signaling microclusters, which are platforms for signal amplification. The physical processes underlying receptor movement and aggregation are not well understood. Here we study the dynamics of single BCRs on activated murine primary B cells using TIRF imaging and single particle tracking. The tracks obtained are analyzed using perturbation expectation-maximization (pEM) a systems-level analysis that allows the identification of different short-time diffusive states from a set of single particle tracks. We identified five different diffusive states on wild type cells, which correspond to different molecular states of the BCR. By using actin polymerization inhibitors and mutant cells lacking important actin regulators we were able to identify the BCR molecule configuration associated with each diffusive state.

  11. Distinct cytokines balance the development of regulatory T cells and interleukin-10-producing regulatory B cells

    Czech Academy of Sciences Publication Activity Database

    Holáň, Vladimír; Zajícová, Alena; Javorková, Eliška; Trošan, Peter; Chudičková, Milada; Pavlíková, M.; Krulová, Magdaléna

    2014-01-01

    Roč. 141, č. 4 (2014), s. 577-586. ISSN 0019-2805 R&D Projects: GA MZd(CZ) NT14102; GA ČR(CZ) GAP301/11/1568; GA ČR GAP304/11/0653 Grant ostatní: GA MŠk(CZ) MSM0021620858 Institutional support: RVO:68378041 Keywords : Autoregulation * B cells * Cytokines Subject RIV: FF - HEENT, Dentistry Impact factor: 3.795, year: 2014

  12. Differential expression of Toll-like receptor (TLR) and B cell receptor (BCR) signaling molecules in primary diffuse large B-cell lymphoma of the central nervous system.

    Science.gov (United States)

    Akhter, Ariz; Masir, Noraidah; Elyamany, Ghaleb; Phang, Kean-Chang; Mahe, Etienne; Al-Zahrani, Ali Matar; Shabani-Rad, Meer-Taher; Stewart, Douglas Allan; Mansoor, Adnan

    2015-01-01

    Primary diffuse large B-cell lymphoma of the central nervous system (CNS DLBCL) is a distinct and aggressive lymphoma that is confined to CNS. Since, central nervous system is barrier-protected and immunologically silent; role of TLR/BCR signaling in pathogenesis and biology of CNS DLBCL is intriguing. Genomic mutations in key regulators of TLR/BCR signaling pathway (MYD88/CD79B/CARD11) have recently been reported in this disease. These observations raised possible implications in novel targeted therapies; however, expression pattern of molecules related to TLR/BCR pathways in this lymphoma remains unknown. We have analyzed the expression of 19 genes encoding TLR/BCR pathways and targets in CNS DLBCLs (n = 20) by Nanostring nCounter™ analysis and compared it with expression patterns in purified reactive B-lymphocytes and systemic diffuse large B cell lymphoma (DLBCL) (n = 20). Relative expression of TLR4, TLR5, TLR9, CD79B and BLNK was higher in CNS DLBCLs than in control B-lymphocytes; where as TLR7, MALT1, BCL10, CD79A and LYN was lower in CNS DLBCLs (P 1.5 fold change; P < 0.01). The B cell receptor molecules like BLNK and CD79B were also associated with higher expression of MYD88 dependent TLRs (TLR4/5/9). In conclusion, we have shown over expression of TLR/BCR related genes or their targets, where genomic mutations have commonly been identified in CNS DLBCL. We have also demonstrated that TLR over expression closely relate with up regulation of genes associated with BCR pathway like CD79B/BLNK and CARD11, which play an important role in NF-kB pathway activation. Our results provide an important insight into the possibility of TLR and/or B-cell receptor signaling molecules as possible therapeutic targets in CNS DLBCL. PMID:25391967

  13. Mesenteric IL-10-producing CD5(+) regulatory B cells suppress cow's milk casein-induced allergic responses in mice.

    Science.gov (United States)

    Kim, A-Ram; Kim, Hyuk Soon; Kim, Do Kyun; Nam, Seung Taek; Kim, Hyun Woo; Park, Young Hwan; Lee, Dajeong; Lee, Min Bum; Lee, Jun Ho; Kim, Bokyung; Beaven, Michael A; Kim, Hyung Sik; Kim, Young Mi; Choi, Wahn Soo

    2016-01-01

    Food allergy is a hypersensitive immune reaction to food proteins. We have previously demonstrated the presence of IL-10-producing CD5(+) B cells and suggested their potential role in regulating cow's milk casein allergy in humans and IgE-mediated anaphylaxis in mice. In this study, we determined whether IL-10-producing CD5(+) regulatory B cells control casein-induced food allergic responses in mice and, if so, the underlying mechanisms. The induction of oral tolerance (OT) by casein suppressed casein-induced allergic responses including the decrease of body temperature, symptom score, diarrhea, recruitment of mast cells and eosinophils into jejunum, and other biological parameters in mice. Notably, the population of IL-10-producing CD5(+) B cells was increased in mesenteric lymph node (MLN), but not in spleen or peritoneal cavity (PeC) in OT mice. The adoptive transfer of CD5(+) B cells from MLN, but not those from spleen and PeC, suppressed the casein-induced allergic responses in an allergen-specific and IL-10-dependent manner. The inhibitory effect of IL-10-producing CD5(+) B cells on casein-induced allergic response was dependent on Foxp3(+) regulatory T cells. Taken together, mesenteric IL-10-producing regulatory B cells control food allergy via Foxp3(+) regulatory T cells and could potentially act as a therapeutic regulator for food allergy. PMID:26785945

  14. A Regulatory Feedback between Plasmacytoid Dendritic Cells and Regulatory B Cells Is Aberrant in Systemic Lupus Erythematosus.

    Science.gov (United States)

    Menon, Madhvi; Blair, Paul A; Isenberg, David A; Mauri, Claudia

    2016-03-15

    Signals controlling the generation of regulatory B (Breg) cells remain ill-defined. Here we report an "auto"-regulatory feedback mechanism between plasmacytoid dendritic cells (pDCs) and Breg cells. In healthy individuals, pDCs drive the differentiation of CD19(+)CD24(hi)CD38(hi) (immature) B cells into IL-10-producing CD24(+)CD38(hi) Breg cells and plasmablasts, via the release of IFN-α and CD40 engagement. CD24(+)CD38(hi) Breg cells conversely restrained IFN-α production by pDCs via IL-10 release. In systemic lupus erythematosus (SLE), this cross-talk was compromised; pDCs promoted plasmablast differentiation but failed to induce Breg cells. This defect was recapitulated in healthy B cells upon exposure to a high concentration of IFN-α. Defective pDC-mediated expansion of CD24(+)CD38(hi) Breg cell numbers in SLE was associated with altered STAT1 and STAT3 activation. Both altered pDC-CD24(+)CD38(hi) Breg cell interactions and STAT1-STAT3 activation were normalized in SLE patients responding to rituximab. We propose that alteration in pDC-CD24(+)CD38(hi) Breg cell interaction contributes to the pathogenesis of SLE. PMID:26968426

  15. Perioperative dynamic alterations in peripheral regulatory T and B cells in patients with hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Chen Tianxiang

    2012-01-01

    Full Text Available Abstract Background Intratumoral and circulating regulatory T cells (Tregs have been shown to be critical in the pathogenesis of hepatocellular carcinoma (HCC. However there is limited knowledge on the alterations of regulatory B cells (Bregs. We here investigated perioperative dynamic alterations of peripheral circulating Tregs and Bregs in HCC patients to reveal the relationship between regulatory lymphocytes and its clinical implications. Methods 36 patients with HCC, 6 with chronic hepatitis B infection and 10 healthy donors were enrolled for this study. Frequencies of peripheral Tregs and Bregs were measured by flow cytometry with antibodies against CD4, CD25, CD127, CD19 and IL-10 before, and after radical surgery. Then, clinical informatics of HCC patients was achieved through Digital Evaluation Score System (DESS for the assessment of disease severity. Finally, we analysed correlations between digitalized clinical features and kinetics of circulating regulatory lymphocytes. Results Level of circulating CD4+CD25+CD127- Tregs in HCC patients was significantly lower than that in healthy donors and patients with chronic hepatitis B infection before surgery, but was increased after surgery. Preoperative level of CD19+ IL-10+ Bregs in HCC patients was also significantly lower than the other groups. However it dramatically was elevated right after surgery and remained elevated compared to controls (about 7 days after surgery, P = 0.04. Frequency of circulating Tregs was correlated with circulating leukocytes, ferritin, and clinical features suggesting tumor aggressiveness including portal vein thrombosis, hepatic vein involvement and advanced clinical stages. Frequency of circulating Bregs was associated with Hepatitis B e Antigen (HBeAg and Hepatitis B virus (HBV DNA copy number. In addition, DESS was significantly and positively correlated with other staging systems. Conclusion Frequencies of peripheral Tregs and Bregs in HCC patients

  16. Characterization of Regulatory B Cells in Graves' Disease and Hashimoto's Thyroiditis

    DEFF Research Database (Denmark)

    Kristensen, Birte; Hegedüs, Laszlo; Lundy, Steven K;

    2015-01-01

    cells from patients with HT. In GD, B cells primed with TG induced IL-10-producing CD4+ T cells. To assess the maximal frequency of inducible IL-10+ B cells in the three donor groups PBMCs were stimulated with PMA/ionomycin. The resulting IL-10+ B-cell frequency was similar in the three groups and...

  17. BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

    International Nuclear Information System (INIS)

    Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs) play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF) is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment

  18. BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2013-10-01

    Full Text Available Primary biliary cirrhosis (PBC is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.

  19. BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo; Hu, Mintao [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China); Zhang, Peng [Nanjing Medical University, Nanjing, Jiangsu (China); Cao, Hong [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China); Wang, Yongzhen [The Second Hospital of Nanjing, Nanjing, Jiangsu (China); Wang, Zheng; Su, Tingting [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China)

    2013-05-10

    Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs) play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF) is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.

  20. BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2013-05-01

    Full Text Available Primary biliary cirrhosis (PBC is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.

  1. Functional role of regulatory T cells in B cell lymphoma and related mechanisms.

    Science.gov (United States)

    Wu, Wei; Wan, Jun; Xia, Ruixiang; Huang, Zhenqi; Ni, Jing; Yang, Mingzhen

    2015-01-01

    B cell lymphoma (BCL) has a higher degree of malignancy and complicated pathogenic mechanism. Regulatory T cells (Treg cells) are known to exert certain immune suppression functions, in addition to immune mediating effects. Recent studies have revealed the role of Treg cells in pathogenesis and progression of multiple malignant tumors. This study therefore investigated the functional role and related mechanism of Treg cells in BCL. A cohort of thirty patients who were diagnosed with BCL in our hospital between January 2013 and December 2014. Another thirty healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were separated and analyzed for the ratio of CD4+/CD25+ Treg cells. The mRNA expression levels of Foxp3, transforming growth factor (TGF)-β1 and interleukin (IL)-10 genes were quantified by real-time PCR, while their serum levels were determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile all laboratory indexes for patients were monitored during the complete remission (CR) stage. BCL patients significantly elevated ratio of CD4+/CD25+ Treg cells, which were decreased at CR stage. mRNA levels of Foxp3, TGF-β1 and IL-10, in addition to protein levels of TGF-β1 and IL-10 were potentiated in lymphoma patients but decreased in CR patients (Pregulating cytokines, thereby facilitating the pathogenesis and progression of lymphoma. PMID:26464657

  2. Identification of a negative regulatory role for spi-C in the murine B cell lineage.

    Science.gov (United States)

    Li, Stephen K H; Solomon, Lauren A; Fulkerson, Patricia C; DeKoter, Rodney P

    2015-04-15

    Spi-C is an E26 transformation-specific family transcription factor that is highly related to PU.1 and Spi-B. Spi-C is expressed in developing B cells, but its function in B cell development and function is not well characterized. To determine whether Spi-C functions as a negative regulator of Spi-B (encoded by Spib), mice were generated that were germline knockout for Spib and heterozygous for Spic (Spib(-/-)Spic(+/-)). Interestingly, loss of one Spic allele substantially rescued B cell frequencies and absolute numbers in Spib(-/-) mouse spleens. Spib(-/-)Spic(+/-) B cells had restored proliferation compared with Spib(-/-) B cells in response to anti-IgM or LPS stimulation. Investigation of a potential mechanism for the Spib(-/-)Spic(+/-) phenotype revealed that steady-state levels of Nfkb1, encoding p50, were elevated in Spib(-/-)Spic(+/-) B cells compared with Spib(-/-) B cells. Spi-B was shown to directly activate the Nfkb1 gene, whereas Spi-C was shown to repress this gene. These results indicate a novel role for Spi-C as a negative regulator of B cell development and function. PMID:25769919

  3. Regulatory IgDhi B Cells Suppress T Cell Function via IL-10 and PD-L1 during Progressive Visceral Leishmaniasis.

    Science.gov (United States)

    Schaut, Robert G; Lamb, Ian M; Toepp, Angela J; Scott, Benjamin; Mendes-Aguiar, Carolina O; Coutinho, Jose F V; Jeronimo, Selma M B; Wilson, Mary E; Harty, John T; Waldschmidt, Thomas J; Petersen, Christine A

    2016-05-15

    During visceral leishmaniasis (VL), Th1-based inflammation is induced to control intracellular parasites. Inflammation-based pathology was shown to be dampened by IL-10 and eventual programmed death 1-mediated T cell exhaustion. Cell type(s) responsible for the initiation of T cell-produced IL-10 during VL are unknown. CD19(+), CD5(-), CD1d(-), IgD(hi) regulatory B cells from healthy controls produced IL-10 in the absence of infection or stimulation, in contrast to IgD(lo/neg) B cells. IgD(hi) B cells may have a de novo versus induced regulatory program. The population of IgD(hi) B cells increased 3-fold as VL progressed. B cells from VL dogs were necessary and sufficient to suppress Th1 cell effector function. IgD(hi) B cells induced IL-10 production by T cells and IgD(lo) B cells. Blockage of B cell-specific PD-L1 restored Th1 responses. IgD(hi) regulatory B cells represent a novel regulatory B cell that may precipitate T cell exhaustion during VL. PMID:27076677

  4. B cell receptor-mediated apoptosis of human lymphocytes is associated with a new regulatory pathway of Bim isoform expression.

    Science.gov (United States)

    Mouhamad, Shahul; Besnault, Laurence; Auffredou, Marie Thérèse; Leprince, Corinne; Bourgeade, Marie Françoise; Leca, Gérald; Vazquez, Aimé

    2004-02-15

    Studies in Bim-deficient mice have shown that the proapoptotic molecule Bim plays a key role in the control of B cell homeostasis and activation. However, the role of Bim in human B lymphocyte apoptosis is unknown. We show in this study that, depending on the degree of cross-linking, B cell receptors can mediate both Bim-dependent and apparent Bim-independent apoptotic pathways. Cross-linked anti-mu Ab-mediated activation induces an original pathway governing the expression of the various Bim isoforms. This new pathway involves the following three sequential steps: 1) extracellular signal-regulated kinase-dependent phosphorylation of the BimEL isoform, which is produced in large amounts in healthy B cells; 2) proteasome-mediated degradation of phosphorylated BimEL; and 3) increased expression of the shorter apoptotic isoforms BimL and BimS. PMID:14764673

  5. Signaling through intercellular adhesion molecule 1 (ICAM-1) in a B cell lymphoma line

    DEFF Research Database (Denmark)

    Holland, J; Owens, T

    1997-01-01

    Intercellular adhesion molecule 1 (ICAM-1) (CD54) is an adhesion molecule of the immunoglobulin superfamily. The interaction between ICAM-1 on B lymphocytes and leukocyte function-associated antigen 1 on T cells plays a major role in several aspects of the immune response, including T-dependent B...

  6. Fingolimod therapy modulates circulating B cell composition, increases B regulatory subsets and production of IL-10 and TGFβ in patients with Multiple Sclerosis.

    Science.gov (United States)

    Blumenfeld, Shiri; Staun-Ram, Elsebeth; Miller, Ariel

    2016-06-01

    Fingolimod, an oral therapeutic agent approved for patients with relapsing-remitting Multiple Sclerosis (MS), has been shown to prevent lymphocyte egress from secondary lymphoid tissues; however the specific drug effect on B cells in fingolimod-treated patients remains to be fully elucidated. We present here a comprehensive analysis on the proportions of B cell subsets in the periphery, and the levels of activation, functional surface markers and cytokine profile of B cells in MS patients, following initiation of fingolimod therapy, using flow cytometry and cytokine bead array. Fingolimod therapy increased the ratio of naïve to memory cells, elevated the percentage of plasma cells and highly increased the proportion of transitional B cells as well as additional regulatory subsets, including: IL10(+), CD25(+) and CD5(+) B cells. The percentage of activated CD69(+) cells was highly elevated in the remaining circulating B cells, which produced increased levels of IL10, TGFβ, IL6, IL4, LTα, TNFα and IFNγ cytokines, with an overall increased ratio of TGFβ to pro-inflammatory cytokines. Furthermore, fingolimod therapy reduced ICAM-1(+) cells, suggesting a possible reduction in antigen-presenting capacity. Phosphorylated-fingolimod was shown in vitro to reduce S1PR1 RNA and protein, to slightly increase viability and to activate anti-apoptotic Bcl2 in transformed B cells of patients with MS. In conclusion, fingolimod therapy modulates significantly the composition of circulating B cells, promoting regulatory subsets and an anti-inflammatory cytokine repertoire. PMID:27055778

  7. Mesenteric IL-10-producing CD5+ regulatory B cells suppress cow’s milk casein-induced allergic responses in mice

    Science.gov (United States)

    Kim, A-Ram; Kim, Hyuk Soon; Kim, Do Kyun; Nam, Seung Taek; Kim, Hyun Woo; Park, Young Hwan; Lee, Dajeong; Lee, Min Bum; Lee, Jun Ho; Kim, Bokyung; Beaven, Michael A.; Kim, Hyung Sik; Kim, Young Mi; Choi, Wahn Soo

    2016-01-01

    Food allergy is a hypersensitive immune reaction to food proteins. We have previously demonstrated the presence of IL-10-producing CD5+ B cells and suggested their potential role in regulating cow’s milk casein allergy in humans and IgE-mediated anaphylaxis in mice. In this study, we determined whether IL-10-producing CD5+ regulatory B cells control casein-induced food allergic responses in mice and, if so, the underlying mechanisms. The induction of oral tolerance (OT) by casein suppressed casein-induced allergic responses including the decrease of body temperature, symptom score, diarrhea, recruitment of mast cells and eosinophils into jejunum, and other biological parameters in mice. Notably, the population of IL-10-producing CD5+ B cells was increased in mesenteric lymph node (MLN), but not in spleen or peritoneal cavity (PeC) in OT mice. The adoptive transfer of CD5+ B cells from MLN, but not those from spleen and PeC, suppressed the casein-induced allergic responses in an allergen-specific and IL-10-dependent manner. The inhibitory effect of IL-10-producing CD5+ B cells on casein-induced allergic response was dependent on Foxp3+ regulatory T cells. Taken together, mesenteric IL-10-producing regulatory B cells control food allergy via Foxp3+ regulatory T cells and could potentially act as a therapeutic regulator for food allergy. PMID:26785945

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

    Directory of Open Access Journals (Sweden)

    Tadafumi Yokoyama

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

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

    Science.gov (United States)

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

    2016-04-01

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

  10. IL-10-producing regulatory B-cells suppressed effector T-cells but enhanced regulatory T-cells in chronic HBV infection.

    Science.gov (United States)

    Liu, Yun; Cheng, Li-Sha; Wu, Sheng-di; Wang, Si-Qi; Li, Lei; She, Wei-Min; Li, Jing; Wang, Ji-Yao; Jiang, Wei

    2016-06-01

    Non-specific immune responses to antigens have been demonstrated as being enhanced during chronic hepatitis B virus (HBV) infection. Here, we evaluated the role of interleukin-10 (IL-10)-producing regulatory B-cells (Bregs) in the pathogenesis of HBV-related liver fibrosis (HBV-LF) and assessed their immunoregulatory effects. Sixty-seven patients diagnosed with chronic hepatitis B (CHB) were enrolled in this study. Numbers and frequencies of peripheral B-cells (memory CD19(+)CD24(hi)CD27(+) cells, immature/transitional CD19(+)CD24(hi)CD38(hi) cells, mature CD19(+)CD24(int)CD38(int) cells) were tested and analysed. Flow cytometry-sorted CD4(+)T cells were cultured with autologous Bregs to elucidate the effects of Bregs on CD4(+)T cells, including effector T and regulatory T-cells (Tregs). The potential immunoregulatory mechanism of Bregs was also investigated. The numbers of total B-cells and Bregs were enriched in CHB patients. The frequency of Bregs was negatively correlated with elevated alanine aminotransferase (ALT) and histological inflammation grades (G), but positively correlated with advanced histological fibrosis stages (S) and enhanced HBV replication. The phenotype of Bregs was predominantly characterized as CD19(+)CD24(hi)CD38(hi) In co-culture with Bregs, CD4(+)CD25(-)T cells from CHB patients produced less interferon-γ (IFN-γ) and IL-17 but more IL-4 than CD4(+)CD25(-)T cells alone, whereas their conversions into Tregs and IL-10(+)T cells were enhanced. In addition, Breg depletion in CHB samples dramatically decreased Treg numbers and expression of cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), IL-10 and transforming growth factor-β (TGF-β). Moreover, the observed regulatory effect was partly dependent on IL-10 release and cell-to-cell contact. Elevated Bregs can suppress effector T but enhance Treg functions, which might influence immune tolerance in chronic HBV infection. PMID:26980345

  11. Rational design of selective small-molecule inhibitors for β-catenin/B-cell lymphoma 9 protein-protein interactions.

    Science.gov (United States)

    Hoggard, Logan R; Zhang, Yongqiang; Zhang, Min; Panic, Vanja; Wisniewski, John A; Ji, Haitao

    2015-09-30

    Selective inhibition of α-helix-mediated protein-protein interactions (PPIs) with small organic molecules provides great potential for the discovery of chemical probes and therapeutic agents. Protein Data Bank data mining using the HippDB database indicated that (1) the side chains of hydrophobic projecting hot spots at positions i, i + 3, and i + 7 of an α-helix had few orientations when interacting with the second protein and (2) the hot spot pockets of PPI complexes had different sizes, shapes, and chemical groups when interacting with the same hydrophobic projecting hot spots of α-helix. On the basis of these observations, a small organic molecule, 4'-fluoro-N-phenyl-[1,1'-biphenyl]-3-carboxamide, was designed as a generic scaffold that itself directly mimics the binding mode of the side chains of hydrophobic projecting hot spots at positions i, i + 3, and i + 7 of an α-helix. Convenient decoration of this generic scaffold led to the selective disruption of α-helix-mediated PPIs. A series of small-molecule inhibitors selective for β-catenin/B-cell lymphoma 9 (BCL9) over β-catenin/cadherin PPIs was designed and synthesized. The binding mode of new inhibitors was characterized by site-directed mutagenesis and structure-activity relationship studies. This new class of inhibitors can selectively disrupt β-catenin/BCL9 over β-catenin/cadherin PPIs, suppress the transactivation of canonical Wnt signaling, downregulate the expression of Wnt target genes, and inhibit the growth of Wnt/β-catenin-dependent cancer cells. PMID:26352795

  12. Anti-CD20 antibody promotes cancer escape via enrichment of tumor-evoked regulatory B cells expressing low levels of CD20 and CD137L.

    Science.gov (United States)

    Bodogai, Monica; Lee Chang, Catalina; Wejksza, Katarzyna; Lai, Jinping; Merino, Maria; Wersto, Robert P; Gress, Ronald E; Chan, Andrew C; Hesdorffer, Charles; Biragyn, Arya

    2013-04-01

    The possible therapeutic benefits of B-cell depletion in combating tumoral immune escape have been debated. In support of this concept, metastasis of highly aggressive 4T1 breast cancer cells in mice can be abrogated by inactivation of tumor-evoked regulatory B cells (tBreg). Here, we report the unexpected finding that B-cell depletion by CD20 antibody will greatly enhance cancer progression and metastasis. Both murine and human tBregs express low levels of CD20 and, as such, anti-CD20 mostly enriches for these cells. In the 4T1 model of murine breast cancer, this effect of enriching for tBregs suggests that B-cell depletion by anti-CD20 may not be beneficial at all in some cancers. In contrast, we show that in vivo-targeted stimulation of B cells with CXCL13-coupled CpG oligonucleotides (CpG-ODN) can block cancer metastasis by inhibiting CD20(Low) tBregs. Mechanistic investigations suggested that CpG-ODN upregulates low surface levels of 4-1BBL on tBregs to elicit granzyme B-expressing cytolytic CD8(+) T cells, offering some explanative power for the effect. These findings underscore the immunotherapeutic importance of tBreg inactivation as a strategy to enhance cancer therapy by targeting both the regulatory and activating arms of the immune system in vivo. PMID:23365136

  13. Tumor-evoked regulatory B cells promote breast cancer metastasis by converting resting CD4⁺ T cells to T-regulatory cells.

    Science.gov (United States)

    Olkhanud, Purevdorj B; Damdinsuren, Bazarragchaa; Bodogai, Monica; Gress, Ronald E; Sen, Ranjan; Wejksza, Katarzyna; Malchinkhuu, Enkhzol; Wersto, Robert P; Biragyn, Arya

    2011-05-15

    Pulmonary metastasis of breast cancer requires recruitment and expansion of T-regulatory cells (Treg) that promote escape from host protective immune cells. However, it remains unclear precisely how tumors recruit Tregs to support metastatic growth. Here we report the mechanistic involvement of a unique and previously undescribed subset of regulatory B cells. These cells, designated tumor-evoked Bregs (tBreg), phenotypically resemble activated but poorly proliferative mature B2 cells (CD19(+) CD25(High) CD69(High)) that express constitutively active Stat3 and B7-H1(High) CD81(High) CD86(High) CD62L(Low) IgM(Int). Our studies with the mouse 4T1 model of breast cancer indicate that the primary role of tBregs in lung metastases is to induce TGF-β-dependent conversion of FoxP3(+) Tregs from resting CD4(+) T cells. In the absence of tBregs, 4T1 tumors cannot metastasize into the lungs efficiently due to poor Treg conversion. Our findings have important clinical implications, as they suggest that tBregs must be controlled to interrupt the initiation of a key cancer-induced immunosuppressive event that is critical to support cancer metastasis. PMID:21444674

  14. Histological analysis on adhesive molecules of renal intravascular large B cell lymphoma treated with CHOP chemotherapy and rituximab.

    Science.gov (United States)

    Kusaba, T; Hatta, T; Tanda, S; Kameyama, H; Tamagaki, K; Okigaki, M; Inaba, T; Shimazaki, C; Sasaki, S

    2006-03-01

    A 48-year-old man was admitted to our hospital for investigation of mild renal dysfunction. A blood examination revealed mild elevation of creatinine level (1.77 mg/dl). Urinary examination revealed mild protein excretion (0.54 g/day) and microhematuria; renal biopsy revealed the focal proliferation of large mononuclear cells with mitosis in glomerular capillaries. According to immunohistochemical analysis, the intravascular lymphomatous cells stained positively with anti-leukocyte common antigen (LCA: CD45) and CD20, indicating a B lymphocyte lineage. In electron microscopy, the glomerular capillary was filled with lymphoma cells and epithelial foot process fusion was noted. Immunohistochemical analysis on adhesive molecules revealed a lack of CD11a expression on lymphoma cells, but positive CD54 expression on endothelial cells. Systemic 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) revealed no abnormal uptake of isotopes. On the basis of these findings, we diagnosed intravascular diffuse large B cell lymphoma localized in the kidney. Despite treatment with rituximab and CHOP (prednisolone, doxorubicin, vincristine, cyclophosphamide) for 3 cycles at 1-month intervals, the renal dysfunction did not change. In histopathological analysis of the second biopsy, lymphoma cells disappeared, but focal segmental glomerulosclerosis and moderate interstitial fibrosis were noted. Electron microscopic findings revealed severe subendothelial edema with mesangial interposition, indicating severe endothelial damage. Epithelial foot process fusion was improved. These pathological analyses let us conclude that a lack of CD11a could be a candidate factor for prevention of the extravasation of lymphoma cells from blood vessels in our patient. We also presumed that the intraglomerular endothelial damage occurred due to chemotherapy-associated cell injury. PMID:16550755

  15. CD54/intercellular adhesion molecule 1 and major histocompatibility complex II signaling induces B cells to express interleukin 2 receptors and complements help provided through CD40 ligation

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1994-01-01

    We have examined signaling roles for CD54 intercellular adhesion molecule 1 and major histocompatibility complex (MHC) II as contact ligands during T help for B cell activation. We used a T helper 1 (Th1)-dependent helper system that was previously shown to be contact as well as interleukin 2 (IL-2......) dependent to demonstrate the relative roles of CD54, MHC II, and CD40 signaling in the events leading to the induction of B cell proliferation and responsiveness to IL-2. Paraformaldehyde-fixed activated Th1-induced expression of IL-2R alpha, IL-2R beta, and B7, and upregulated MHC II and CD54 on B cells...

  16. IL-9 contributes to immunosuppression mediated by regulatory T cells and mast cells in B-cell non-hodgkin's lymphoma.

    Science.gov (United States)

    Feng, Li-Li; Gao, Jun-Ming; Li, Pei-Pei; Wang, Xin

    2011-12-01

    It has been known that regulatory T (Treg) cells and mast cells (MCs) are involved in tumor immunity regulation, but the exact roles and mechanisms of Treg cells and MCs in B-cell non-Hodgkin's lymphoma (NHL) are incompletely defined. In the present study, we found that the number of Foxp3(+) Treg cells and CD117(+) MCs increased in B-cell NHL patients. Concomitantly, a high level of interleukin (IL)-9 was observed in the sera from B-cell NHL patients. Neutralizing IL-9 significantly inhibited tumor growth in the lymphoma model of murine, and this process was associated with down-regulation of Treg cells and MCs. Furthermore, IL-9 was also demonstrated to induce expression of MC-related genes and proliferation of MCs from the bone marrow stem cells. Collectively, our results indicate that Treg cell and MCs are involved in immunosuppression in B-cell NHL, and IL-9 is a key mediator of Treg cells and MCs in that process. These findings provide novel insight for the pathogenesis and possible therapeutic strategy of B-cell NHL. PMID:21898141

  17. Characterization and functional studies of forkhead box protein 3(-) lymphocyte activation gene 3(+) CD4(+) regulatory T cells induced by mucosal B cells.

    Science.gov (United States)

    Chu, K-H; Chiang, B-L

    2015-05-01

    The induction of mucosal tolerance has been demonstrated to be an effective therapeutic approach for the treatment of allergic diseases. Our previous study demonstrated that Peyer's patch B cells could convert naive T cells into regulatory T cells (so-called Treg -of-B(P) cells); however, it is important to characterize this particular subset of Treg -of-B cells for future applications. This study aimed to investigate the role of lymphocyte activating gene 3 (LAG3) in mediating the regulatory function of Treg -of-B(P) cells induced by mucosal follicular B (FOB) cells. Microarray analysis and real-time polymerase chain reaction (PCR) were used to assess the gene expression pattern of Treg -of-B(P) cells. To evaluate the role of LAG3, the in-vitro suppressive function and the alleviation of airway inflammation in a murine model of asthma was assessed. Our data indicated that FOB cells isolated from Peyer's patches had the ability to generate more suppressive Treg -of-B cells with LAG3 expression, compared with CD23(lo) CD21(lo) B cells. LAG3 is not only a marker for Treg -of-B(P) cells, but also participate in the suppressive ability. Moreover, CCR4 and CCR6 could be detected on the LAG3(+) , not LAG3(-) , Treg -of-B(P) cells and would help cells homing to allergic lung. In the murine model of asthma, the adoptive transfer of LAG3(+) Treg -of-B(P) cells was able to sufficiently suppress T helper type 2 (Th2) cytokine production, eosinophil infiltration and alleviate asthmatic symptoms. LAG3 was expressed in Treg -of-B(P) cells and was also involved in the function of Treg -of-B(P) cells. In the future, this particular subset of Treg -of-B cells might be used to alleviate allergic symptoms. PMID:25581421

  18. B cells and immunological tolerance.

    Science.gov (United States)

    Manjarrez-Orduño, Nataly; Quách, Tâm D; Sanz, Iñaki

    2009-02-01

    Work from multiple groups continues to provide additional evidence for the powerful and highly diverse roles, both protective and pathogenic, that B cells play in autoimmune diseases. Similarly, it has become abundantly clear that antibody-independent functions may account for the opposing influences that B cells exercise over other arms of the immune response and ultimately over autoimmunity itself. Finally, it is becoming apparent that the clinical impact of B-cell depletion therapy may be, to a large extent, determined by the functional balance between different B-cell subsets that may be generated by this therapeutic intervention. In this review, we postulate that our perspective of B-cell tolerance and our experimental approach to its understanding are fundamentally changed by this view of B cells. Accordingly, we first discuss current knowledge of B-cell tolerance conventionally defined as the censoring of autoantibody-producing B cells (with an emphasis on human B cells). Therefore, we discuss a different model that contemplates B cells not only as targets of tolerance but also as mediators of tolerance. This model is based on the notion that the onset of clinical autoimmune disease may require a B-cell gain-of-pathogenic function (or a B-cell loss-of-regulatory-function) and that accordingly, disease remission may depend on the restoration of the physiological balance between B-cell pathogenic and protective functions. PMID:19148217

  19. Regulatory B Cells from Hilar Lymph Nodes of Tolerant Mice in a Murine Model of Allergic Airway Disease are CD5+, Express TGF-β and Co-localize with CD4+Foxp3+ T Cells

    OpenAIRE

    Natarajan, Prabitha; Singh, Anurag; McNamara, Jeffrey T.; Secor, Eric R.; Guernsey, Linda A.; Thrall, Roger S.; Craig M. Schramm

    2012-01-01

    In a biphasic, ovalbumin (OVA)-induced murine asthma model where allergic airway disease is followed by resolution and the development of local inhalational tolerance (LIT), TGFβ-expressing CD5+ B cells were selectively expanded locally in hilar lymph nodes (HLN) of LIT mice. LIT HLN CD5+ B cells but not LIT HLN CD5− B cells induced expression of Foxp3 in CD4+ CD25− T cells in vitro. These CD5+ regulatory B cells and CD4+Foxp3+ T cells demonstrated similar increases in expression of chemokine...

  20. From the regulatory functions of B cells to the identification of cytokine-producing plasma cell subsets.

    Science.gov (United States)

    Dang, Van Duc; Hilgenberg, Ellen; Ries, Stefanie; Shen, Ping; Fillatreau, Simon

    2014-06-01

    B lymphocytes have a unique role as antibody-producing cells. Antibodies are key mediators of humoral immunity against infections, and are thought to account for the protection afforded by successful vaccines. B cells can also secrete cytokines and subsequently regulate immune responses mediated by T and innate cells. Remarkably, recent studies identified plasma blasts/plasma cells as the main types of activated B cells producing the cytokines interleukin (IL)-10, IL-35, tumor necrosis factor (TNF)-α, IL-17, and GM-CSF in various contexts in mice. Here, we discuss these observations, which suggest the existence of various subsets of plasma blast/plasma cells distinguishable through their cytokine expression pattern. PMID:24637161

  1. An in silico approach reveals associations between genetic and epigenetic factors within regulatory elements in B cells from primary Sjögren’s syndrome patients

    Directory of Open Access Journals (Sweden)

    Orsia D. Konsta

    2015-08-01

    Full Text Available Recent advances in genetics have highlighted several regions and candidate genes associated with primary Sjögren's syndrome (SS, a systemic autoimmune epithelitis that combines exocrine gland dysfunctions, and focal lymphocytic infiltrations. In addition to genetic factors, it is now clear that epigenetic deregulations are present during SS and restricted to specific cell type subsets such as lymphocytes and salivary gland epithelial cells. In this study, 72 single nucleotide polymorphisms (SNPs associated with 43 SS gene risk factors were selected from publicly available and peer reviewed literature for further in silico analysis. SS risk variant location was tested revealing a broad distribution in coding sequences (5.6%, intronic sequences (55.6%, upstream/downstream genic regions (30.5%, and intergenic regions (8.3%. Moreover, a significant enrichment of regulatory motifs (promoter, enhancer, insulator, DNAse peak and eQTL characterizes SS risk variants (94.4%. Next, screening SNPs in high linkage disequilibrium (r2 ≥ 0.8 in Caucasians revealed 645 new variants including 5 SNPs with missense mutations, and indicated an enrichment of transcriptionally active motifs according to the cell type (B cells > monocytes > T cells >> A549. Finally, we looked at SS risk variants for histone markers in B cells (GM12878, monocytes (CD14+ and epithelial cells (A548. Active histone markers were associated with SS risk variants at both promoters and enhancers in B cells, and within enhancers in monocytes. In conclusion and based on the obtained in silico results, that need further confirmation, associations were observed between SS genetic risk factors and epigenetic factors and these associations predominate in B cells such as those observed at the FAM167A-BLK locus.

  2. Similar disturbances in B cell activity and regulatory T cell function in Henoch-Schonlein purpura and systemic lupus erythematosus

    International Nuclear Information System (INIS)

    The immunoglobulin synthesizing activities of peripheral mononuclear cells (MNC) from five patients with Henoch-Schonlein purpura (HSP) and eight patients with active systemic lupus erythematosus (SLE) were compared. Cumulative amounts of IgM, IgG, and IgA synthesized and secreted by unstimulated and PWM-stimulated patient cells over a 12-day period were determied in a solid-phase radioimmunoassay. In unstimulated control cultures mean rates of IgM, IgG, and IgA synthesis were less than 250 ng/ml. The synthetic activities of patient MNC were markedly increased. In HSP cultures IgA was the major immunoglobulin class produced (2810 x/divide 1.33 ng/ml) followed by IgG (1754 x/divide 1.32 ng/ml) and IgM (404 x/divide 1.16 ng/ml). In SLE cultures IgA and IgG syntheses were equally elevated (4427 x/divide 1.20 and 4438 x/divide 1.49 ng/ml, respectively) whereas IgM synthesis averaged 967 x/divide 1.66 ng/ml. PWM stimulation of pateient MNC caused a sharp decline in the synthesis of all three immunoglobulin classes. After T cell depletion B cell-enriched fractions from HSP and SLE patients maintained high levels of IgA and IgG synthesis that were inhibited by PWM and by normal allogeneic but not autologous T cells. In PWM-stimulted co-cultures, patient T cells nonspecifically suppressed the synthetic activities of autologous and control B cells. in contrast patient B cells achieved normal levels of immunoglobulin synthesis when cultured with control T cells plus PWM. In longitudinal studies patient B and T cell disturbances persisted despite clinical improvement

  3. An in silico Approach Reveals Associations between Genetic and Epigenetic Factors within Regulatory Elements in B Cells from Primary Sjögren's Syndrome Patients.

    Science.gov (United States)

    Konsta, Orsia D; Le Dantec, Christelle; Charras, Amandine; Brooks, Wesley H; Arleevskaya, Marina I; Bordron, Anne; Renaudineau, Yves

    2015-01-01

    Recent advances in genetics have highlighted several regions and candidate genes associated with primary Sjögren's syndrome (SS), a systemic autoimmune epithelitis that combines exocrine gland dysfunctions, and focal lymphocytic infiltrations. In addition to genetic factors, it is now clear that epigenetic deregulations are present during SS and restricted to specific cell type subsets, such as lymphocytes and salivary gland epithelial cells. In this study, 72 single nucleotide polymorphisms (SNPs) associated with 43 SS gene risk factors were selected from publicly available and peer reviewed literature for further in silico analysis. SS risk variant location was tested revealing a broad distribution in coding sequences (5.6%), intronic sequences (55.6%), upstream/downstream genic regions (30.5%), and intergenic regions (8.3%). Moreover, a significant enrichment of regulatory motifs (promoter, enhancer, insulator, DNAse peak, and expression quantitative trait loci) characterizes SS risk variants (94.4%). Next, screening SNPs in high linkage disequilibrium (r (2) ≥ 0.8 in Caucasians) revealed 645 new variants including 5 SNPs with missense mutations, and indicated an enrichment of transcriptionally active motifs according to the cell type (B cells > monocytes > T cells ≫ A549). Finally, we looked at SS risk variants for histone markers in B cells (GM12878), monocytes (CD14(+)) and epithelial cells (A548). Active histone markers were associated with SS risk variants at both promoters and enhancers in B cells, and within enhancers in monocytes. In conclusion and based on the obtained in silico results that need further confirmation, associations were observed between SS genetic risk factors and epigenetic factors and these associations predominate in B cells, such as those observed at the FAM167A-BLK locus. PMID:26379672

  4. Down modulation of MHC surface molecules on B cells by suppressive immune complexes obtained from chronic intestinal schistosomiasis patients.

    Science.gov (United States)

    Rezende, S A; Gollob, K J; Correa-Oliveira, R; Goes, A M

    1998-06-01

    Granulomatous inflammation around parasite eggs is the prominent lesion in human schistosomiasis. Studies have suggested the involvement of a series of suppressive mechanisms in the control of this reaction, such as macrophages, cytokines, idiotypic interactions and immune complexes (IC). The studies examine the role of IC obtained from chronic intestinal schistosomiasis patients (ISP) in the reactivity of peripheral blood mononuclear cells (PBMC). The results have shown that these immune complexes are able to suppress cell reactivity by inducing an increase in the production of soluble mediators such as prostaglandins and IL-10. To gain a better understanding of how this suppression occurs the present study examines the phenotypic pattern of PBMC after immune complex treatment in cell proliferation assays. These data show that cultures including immune complex present a higher percentage of B lymphocytes in which a lower expression of a MHC-class II gene product, HLA-DR was detected. This altered expression of the HLA-DR molecule on B lymphocytes after IC treatment suggests a novel mechanism for the suppression observed, that is, IC might decrease the antigen-presenting function of B lymphocytes. PMID:9698100

  5. 关键分子SYK和BTK活性的动态调节控制B细胞受体信号转导过程%Dynamic regulating of the reactivity of key molecules SYK and BTK controls the B cell receptor signaling pathway

    Institute of Scientific and Technical Information of China (English)

    刘顺会; 肖兰凤; 黄树林

    2009-01-01

    Objective To develop and simulate a dynamic model dealing with the quantitatively regulatory relationship among interacting molecules involved in B cell receptor signaling pathway. Methods Based on KEGG database and related literatures in Eng- fish and Chinese, the interaction mode and quantitative relationship of the related molecules involved in B cell receptor signaling path-way were illustrated. By using Simulink'toolbox of Matlab7.0, a dynamic model of B cell receptor signaling pathway was developed and simulated. Results Model simulation results could reflect quantitatively the complex regulatory relationship among the interacting mole-cules involved in B cell receptor signaling pathway. In addition, model simulation could help to find and identify the key molecules in this signaling pathway. Conclusion Dynamic regulating of the reactivity of key molecules SYK and BTK controls the dynamics of B cell receptor signaling pathway.%目的 建立B细胞受体信号途径的动力学模型,通过模型仿真揭示B细胞受体信号途径各分子间的动态调控过程.方法 根据数据库KEGG及相关中英文文献,提取B细胞受体信号转导各条通路相关分子作用的方式及数量关系,利用Matlab7.0的Simulink工具箱构建信号途径的动力学模型并仿真.结果 模型仿真结果能够从数量上反映B细胞受体信号途径中各分子间复杂的调控关系,并能通过模型仿真发现和验证该信号途径中的关键分子.结论 关键分子SYK和BTK活性的动态调节机制控制着B细胞受体信号途径的动力学过程.

  6. Alteration of circulating type 2 follicular helper T cells and regulatory B cells underlies the comorbid association of allergic rhinitis with bronchial asthma.

    Science.gov (United States)

    Kamekura, Ryuta; Shigehara, Katsunori; Miyajima, Satsuki; Jitsukawa, Sumito; Kawata, Koji; Yamashita, Keiji; Nagaya, Tomonori; Kumagai, Ayako; Sato, Akinori; Matsumiya, Hiroshi; Ogasawara, Noriko; Seki, Nobuhiko; Takano, Kenichi; Kokai, Yasuo; Takahashi, Hiroki; Himi, Tetsuo; Ichimiya, Shingo

    2015-06-01

    Allergic rhinitis (AR), the most common allergic disorder of the airway, is often accompanied by bronchial asthma. However, little is known about the mechanism by which AR advances to AR comorbid with bronchial asthma (AR+Asthma). To determine the pathophysiologic features of AR and AR+Asthma, we examined subsets of follicular helper T (Tfh) cells and regulatory B (Breg) cells in peripheral blood from AR and AR+Asthma patients. The results showed polarization of Tfh2 cells within Tfh cell subsets in both AR and AR+Asthma cases. Interestingly, the %Breg cells in total B cells were decreased in AR cases and, more extensively, in AR+Asthma cases. Moreover, we found significant correlations of fractional exhaled nitric oxide and blood eosinophil levels with the index %Tfh2 cells per %Breg cells. Our findings indicate that relative decrease in Breg cells under the condition of Tfh2 cell skewing is a putative exaggerating factor of AR to bronchial asthma. PMID:25829231

  7. Antidiabetic effects of glucokinase regulatory protein small-molecule disruptors

    Science.gov (United States)

    Lloyd, David J.; St Jean, David J.; Kurzeja, Robert J. M.; Wahl, Robert C.; Michelsen, Klaus; Cupples, Rod; Chen, Michelle; Wu, John; Sivits, Glenn; Helmering, Joan; Komorowski, Renée; Ashton, Kate S.; Pennington, Lewis D.; Fotsch, Christopher; Vazir, Mukta; Chen, Kui; Chmait, Samer; Zhang, Jiandong; Liu, Longbin; Norman, Mark H.; Andrews, Kristin L.; Bartberger, Michael D.; van, Gwyneth; Galbreath, Elizabeth J.; Vonderfecht, Steven L.; Wang, Minghan; Jordan, Steven R.; Véniant, Murielle M.; Hale, Clarence

    2013-12-01

    Glucose homeostasis is a vital and complex process, and its disruption can cause hyperglycaemia and type II diabetes mellitus. Glucokinase (GK), a key enzyme that regulates glucose homeostasis, converts glucose to glucose-6-phosphate in pancreatic β-cells, liver hepatocytes, specific hypothalamic neurons, and gut enterocytes. In hepatocytes, GK regulates glucose uptake and glycogen synthesis, suppresses glucose production, and is subject to the endogenous inhibitor GK regulatory protein (GKRP). During fasting, GKRP binds, inactivates and sequesters GK in the nucleus, which removes GK from the gluconeogenic process and prevents a futile cycle of glucose phosphorylation. Compounds that directly hyperactivate GK (GK activators) lower blood glucose levels and are being evaluated clinically as potential therapeutics for the treatment of type II diabetes mellitus. However, initial reports indicate that an increased risk of hypoglycaemia is associated with some GK activators. To mitigate the risk of hypoglycaemia, we sought to increase GK activity by blocking GKRP. Here we describe the identification of two potent small-molecule GK-GKRP disruptors (AMG-1694 and AMG-3969) that normalized blood glucose levels in several rodent models of diabetes. These compounds potently reversed the inhibitory effect of GKRP on GK activity and promoted GK translocation both in vitro (isolated hepatocytes) and in vivo (liver). A co-crystal structure of full-length human GKRP in complex with AMG-1694 revealed a previously unknown binding pocket in GKRP distinct from that of the phosphofructose-binding site. Furthermore, with AMG-1694 and AMG-3969 (but not GK activators), blood glucose lowering was restricted to diabetic and not normoglycaemic animals. These findings exploit a new cellular mechanism for lowering blood glucose levels with reduced potential for hypoglycaemic risk in patients with type II diabetes mellitus.

  8. Various domains of the B-cell regulatory molecule CD72 has diverged at different rates in mammals

    DEFF Research Database (Denmark)

    Petersen, Cathrine Bie; Hillig, Ann-Britt Nygaard; Fredholm, Merete;

    2007-01-01

    highly transcribed in lymph node, thymus and lung tissues as well as in pulmonary alveolar macrophages. The predicted porcine CD72 polypeptide shows conservation of immunoreceptor tyrosine-based inhibitory motifs and an extracellular C-type lectin domain. Compared to CD72 sequences from other mammals as...

  9. Tris (dibenzylideneacetone) dipalladium: a small-molecule palladium complex is effective in inducing apoptosis in chronic lymphocytic leukemia B-cells.

    Science.gov (United States)

    Kay, Neil E; Sassoon, Traci; Secreto, Charla; Sinha, Sutapa; Shanafelt, Tait D; Ghosh, Asish K; Arbiser, Jack L

    2016-10-01

    Here we tested impact of Tris (dibenzylideneacetone) dipalladium (Tris-DBA) on chronic lymphocytic leukemia (CLL) B-cell survival. Indeed, treatment of CLL B-cells with Tris-DBA induced apoptosis in a dose-dependent manner irrespective of IgVH mutational status. Further analyses suggest that Tris-DBA-induced apoptosis involves reduced expression of the anti-apoptotic proteins Bcl-xL, and XIAP with an upregulation of the pro-apoptotic protein BIM in CLL B-cells. Our findings also indicate that Tris-DBA targets the ribosomal protein (rp)-S6, an essential component of the Akt/mTOR signaling axis in CLL B-cells. Of interest, CLL bone marrow stromal cells were unable to protect the leukemic B cells from Tris-DBA-induced apoptosis in an in vitro co-culture system. Finally, co-administration of Tris-DBA and the purine nucleoside analog fludarabine (F-ara-A) augmented CLL B-cell apoptosis levels in vitro showing synergistic effects. In total, Tris-DBA is effective at inducing apoptosis in CLL B-cells even in the presence of stromal cells likely by targeting directly the signal mediator, rpS6. PMID:27189785

  10. 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. PMID:22609854

  11. 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....

  12. HIV-Infected Spleens Present Altered Follicular Helper T Cell (Tfh Subsets and Skewed B Cell Maturation.

    Directory of Open Access Journals (Sweden)

    Lucie Colineau

    Full Text Available Follicular helper T (Tfh cells within secondary lymphoid organs control multiple steps of B cell maturation and antibody (Ab production. HIV-1 infection is associated with an altered B cell differentiation and Tfh isolated from lymph nodes of HIV-infected (HIV+ individuals provide inadequate B cell help in vitro. However, the mechanisms underlying this impairment of Tfh function are not fully defined. Using a unique collection of splenocytes, we compared the frequency, phenotype and transcriptome of Tfh subsets in spleens from HIV negative (HIV- and HIV+ subjects. We observed an increase of CXCR5+PD-1highCD57-Tfh and germinal center (GC CD57+ Tfh in HIV+ spleens. Both subsets showed a reduced mRNA expression of the transcription factor STAT-3, co-stimulatory, regulatory and signal transduction molecules as compared to HIV- spleens. Similarly, Foxp3 expressing follicular regulatory T (Tfr cells were increased, suggesting sustained GC reactions in chronically HIV+ spleens. As a consequence, GC B cell populations were expanded, however, complete maturation into memory B cells was reduced in HIV+ spleens where we evidenced a compromised production of B cell-activating cytokines such as IL-4 and IL-10. Collectively our data indicate that, although Tfh proliferation and GC reactions seem to be ongoing in HIV-infected spleens, Tfh "differentiation" and expression of costimulatory molecules is skewed with a profound effect on B cell maturation.

  13. Epigenetic Control of B Cell Development and B-Cell-Related Immune Disorders.

    Science.gov (United States)

    Bao, Yan; Cao, Xuetao

    2016-06-01

    B lymphocytes are generally recognized as the essential component of humoral immunity and also a regulator of innate immunity. The development of B cells is precisely regulated by a variety of factors via different mechanisms, including cytokine/cytokine receptors, signal transduction molecules, and transcription factors. Recent findings suggest that epigenetic factors, such as DNA methylation, histone modification, and non-coding RNA, play critical roles in establishing B cell lineage-specific gene expression profiles to define and sustain B cell identity and function. Epigenetic modifications are also sensitive to external stimuli and might bridge genetic and environmental factors in the pathogenesis or control of B-cell-related immune disorders, such as autoimmune diseases, lymphoma, and leukemia. Better understanding of the epigenetic mechanisms for regulating B cell development and involving B cell abnormal differentiation and function will shed light on the design of new therapeutic approaches to B-cell-related diseases, and potential candidates of epigenetic modulators may be identified to target epigenetic pathways to prevent or treat B cell disorders. We summarize the relevance of epigenetic marks and landscapes in the stages of B cell development, discuss the interaction of the transcriptional networks and epigenetic changes, and review the involvement of epigenetic risk in the pathogenesis of B-cell-related diseases. Understanding how specific epigenetic alterations contribute to the development of B-cell-related autoimmunity and malignancies is instrumental to control B cell disorders. PMID:26066671

  14. Illuminating vitamin D effects on B cells--the multiple sclerosis perspective.

    Science.gov (United States)

    Rolf, Linda; Muris, Anne-Hilde; Hupperts, Raymond; Damoiseaux, Jan

    2016-03-01

    Vitamin D is associated with many immune-mediated disorders. In multiple sclerosis (MS) a poor vitamin D status is a major environmental factor associated with disease incidence and severity. The inflammation in MS is primarily T-cell-mediated, but increasing evidence points to an important role for B cells. This has paved the way for investigating vitamin D effects on B cells. In this review we elaborate on vitamin D interactions with antibody production, T-cell-stimulating capacity and regulatory B cells. Although in vitro plasma cell generation and expression of co-stimulatory molecules are inhibited and the function of regulatory B cells is promoted, this is not supported by in vivo data. We speculate that differences might be explained by the B-cell-Epstein-Barr virus interaction in MS, the exquisite role of germinal centres in B-cell biology, and/or in vivo interactions with other hormones and vitamins that interfere with the vitamin D pathways. Further research is warranted to illuminate this tube-versus-body paradox. PMID:26714674

  15. MicroRNAs in B-cells

    DEFF Research Database (Denmark)

    Marques, Sara Correia; Laursen, Maria Bach; Bødker, Julie Støve; Kjeldsen, Malene Krag; Larsen, Steffen Falgreen; Schmitz, Alexander; Bøgsted, Martin; Johnsen, Hans Erik; Dybkær, Karen

    2015-01-01

    transformation due to their function as oncogenes or tumor suppressors. We know that miRNAs are involved in the development of normal B-cells and that different B-cell subsets express specific miRNA profiles according to their degree of differentiation. B-cell-derived malignancies contain transcription......MicroRNAs (miRNAs) are small non-coding RNAs that play important post-transcriptional regulatory roles in a wide range of biological processes. They are fundamental to the normal development of cells, and evidence suggests that the deregulation of specific miRNAs is involved in malignant...... signatures reminiscent of their cell of origin. Therefore, we believe that normal and malignant B-cells share features of regulatory networks controlling differentiation and the ability to respond to treatment. The involvement of miRNAs in these processes makes them good biomarker candidates. B...

  16. Detection of Critical Genes Associated with Overall Survival (OS) and Progression-Free Survival (PFS) in Reconstructed Canine B-Cell Lymphoma Gene Regulatory Network (GRN).

    Science.gov (United States)

    Zamani-Ahmadmahmudi, Mohamad; Najafi, Ali; Nassiri, Seyed Mahdi

    2016-01-01

    Canine B-cell lymphoma GRN was reconstructed from gene expression data in the STRING and MiMI databases. Critical genes of networks were identified and correlations of critical genes with overall survival (OS) and progression-free survival (PFS) were evaluated. Significant changes were detected in the expressions of GLUL, CD44, CD79A, ARF3, FOS, BLOC1S1, FYN, GZMB, GALNT3, IFI44, CD3G, GNG2, ESRP1, and CCND1 in the STRING network and of PECAM1, GLUL, CD44, GDI1, E2F4, TLE1, CD79A, UCP2, CCND1, FYN, RHOQ, BIN1, and A2M in the MiMI network. Final survival analysis highlighted CCND1 and FOS as genes with significant correlations with OS and PFS. PMID:26818715

  17. Intratumoral regulatory T cells upregulate immunosuppressive molecules in head and neck cancer patients

    OpenAIRE

    Jie, H-B; Gildener-Leapman, N; Li, J.; Srivastava, R. M.; Gibson, S P; Whiteside, T L; Ferris, R. L.

    2013-01-01

    Background: Although regulatory T cells (Treg) are highly enriched in human tumours compared with peripheral blood, expression of the immune-checkpoint receptors, immunosuppressive molecules and function of Treg in these two sites remains undefined. Methods: Tumour-infiltrating lymphocytes and peripheral blood lymphocytes were isolated from a cohort of head and neck squamous cell carcinoma (HNSCC) patients. The immunosuppressive phenotypes and function of intratumoral Treg were compared with ...

  18. Dissecting the regulatory microenvironment of a large animal model of non-Hodgkin lymphoma: evidence of a negative prognostic impact of FOXP3+ T cells in canine B cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Dammy Pinheiro

    Full Text Available The cancer microenvironment plays a pivotal role in oncogenesis, containing a number of regulatory cells that attenuate the anti-neoplastic immune response. While the negative prognostic impact of regulatory T cells (Tregs in the context of most solid tissue tumors is well established, their role in lymphoid malignancies remains unclear. T cells expressing FOXP3 and Helios were documented in the fine needle aspirates of affected lymph nodes of dogs with spontaneous multicentric B cell lymphoma (BCL, proposed to be a model for human non-Hodgkin lymphoma. Multivariable analysis revealed that the frequency of lymph node FOXP3(+ T cells was an independent negative prognostic factor, impacting both progression-free survival (hazard ratio 1.10; p = 0.01 and overall survival (hazard ratio 1.61; p = 0.01 when comparing dogs showing higher than the median FOXP3 expression with those showing the median value of FOXP3 expression or less. Taken together, these data suggest the existence of a population of Tregs operational in canine multicentric BCL that resembles thymic Tregs, which we speculate are co-opted by the tumor from the periphery. We suggest that canine multicentric BCL represents a robust large animal model of human diffuse large BCL, showing clinical, cytological and immunophenotypic similarities with the disease in man, allowing comparative studies of immunoregulatory mechanisms.

  19. Design of targeted B cell killing agents.

    Directory of Open Access Journals (Sweden)

    Alexey V Stepanov

    Full Text Available B cells play an important role in the pathogenesis of both systemic and organ-specific autoimmune diseases. Autoreactive B cells not only produce autoantibodies, but also are capable to efficiently present specific autoantigens to T cells. Furthermore, B cells can secrete proinflammatory cytokines and amplify the vicious process of self-destruction. B cell-directed therapy is a potentially important approach for treatment of various autoimmune diseases. The depletion of B cells by anti-CD20/19 monoclonal antibody Retuximab® used in autoimmune diseases therapy leads to systemic side effects and should be significantly improved. In this study we designed a repertoire of genetically engineered B cell killers that specifically affected one kind of cells carrying a respective B cell receptor. We constructed immunotoxins (ITs, fused with c-myc epitope as a model targeting sequence, based on barnase, Pseudomonas toxin, Shiga-like toxin E.coli and Fc domain of human antibody IgGγ1. C-MYC hybridoma cell line producing anti-c-myc IgG was chosen as a model for targeted cell depletion. C-myc sequence fused with toxins provided addressed delivery of the toxic agent to the target cells. We demonstrated functional activity of designed ITs in vitro and showed recognition of the fusion molecules by antibodies produced by targeted hybridoma. To study specificity of the proposed B cells killing molecules, we tested a set of created ITs ex vivo, using C-MYC and irrelevant hybridoma cell lines. Pseudomonas-containing IT showed one of the highest cytotoxic effects on the model cells, however, possessed promiscuous specificity. Shiga-like toxin construct demonstrated mild both cytotoxicity and specificity. Barnase and Fc-containing ITs revealed excellent balance between their legibility and toxic properties. Moreover, barnase and Fc molecules fused with c-myc epitope were able to selectively deplete c-myc-specific B cells and decrease production of anti

  20. Nitrogen modulation of legume root architecture signalling pathways involves phytohormones and small regulatory molecules

    Directory of Open Access Journals (Sweden)

    Nadiatul Akmal Mohd-Radzman

    2013-10-01

    Full Text Available Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

  1. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    D. Mesquita Júnior

    2014-08-01

    Full Text Available Regulatory T (TREG cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE. TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25+/highCD127Ø/lowFoxP3+, and effector T cells were defined as CD25+CD127+FoxP3Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4+TREG and CD28+TREG cells and an increased frequency of CD40L+TREG cells. There was a decrease in the TREG/effector-T ratio for GITR+, HLA-DR+, OX40+, and CD45RO+ cells, and an increased ratio of TREG/effector-T CD40L+ cells in patients with SLE. In addition, CD40L+TREG cell frequency correlated with the SLE disease activity index (P=0.0163. In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.

  2. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita Júnior, D. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cruvinel, W.M. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Departamento de Biomedicina, Universidade Católica de Goiás, Goiânia, GO (Brazil); Araujo, J.A.P. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Salmazi, K.C.; Kallas, E.G. [Disciplina de Imunologia Clínica e Alergia, Departamento de Clínica Médica, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Andrade, L.E.C. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-08-22

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25{sup +/high}CD127{sup Ø/low}FoxP3{sup +}, and effector T cells were defined as CD25{sup +}CD127{sup +}FoxP3{sup Ø}. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4{sup +}TREG and CD28{sup +}TREG cells and an increased frequency of CD40L{sup +}TREG cells. There was a decrease in the TREG/effector-T ratio for GITR{sup +}, HLA-DR{sup +}, OX40{sup +}, and CD45RO{sup +} cells, and an increased ratio of TREG/effector-T CD40L{sup +} cells in patients with SLE. In addition, CD40L{sup +}TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.

  3. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25+/highCD127Ø/lowFoxP3+, and effector T cells were defined as CD25+CD127+FoxP3Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4+TREG and CD28+TREG cells and an increased frequency of CD40L+TREG cells. There was a decrease in the TREG/effector-T ratio for GITR+, HLA-DR+, OX40+, and CD45RO+ cells, and an increased ratio of TREG/effector-T CD40L+ cells in patients with SLE. In addition, CD40L+TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease

  4. Ibrutinib for B cell malignancies

    OpenAIRE

    Novero, Aileen; Ravella, Pavan M; Chen, Yamei; Dous, George; Liu, Delong

    2014-01-01

    Research over the role of Bruton’s agammaglobulinemia tyrosine kinase (BTK) in B-lymphocyte development, differentiation, signaling and survival has led to better understanding of the pathogenesis of B-cell malignancies. Down-regulation of BTK activity is an attractive novel strategy for treating patients with B-cell malignancies. Ibrutinib (PCI-32765), a potent inhibitor of BTK induces impressive responses in B-cell malignancies through irreversible bond with cysteine-481 in the active site ...

  5. Evaluating of VDR Gene Variation and its Interaction with Immune Regulatory Molecules in Osteoporosis

    Directory of Open Access Journals (Sweden)

    A Hossein-nezhad

    2009-06-01

    Full Text Available "nBackground: To evaluate VDR gene variation and its interaction with immune regulatory molecules in osteoporosis."nMethods: Totally 205 pre and postmenopausal women were recruited in the study. After an overnight fast, peripheral blood was taken and centrifuged to sprat serum for measurement of serum parathyroid hormone, 25 hydroxyvitamin D, osteocal­cin and cross laps. The FokI polymorphism in exon 2 of the VDR gene was detected by PCR-RFLP. Expression of osteopro­tegrin, vitamin D receptor (VDR and β-actin genes were quantified by quantitative real-time reverse transcriptase. To design the experimental model we randomly selected five participants of each genotype groups. PBMC were cultured and induced with vitamin D. At several times, cells were harvested and total RNA was extracted .Then expression of target genes evaluated by real time PCR."nResults: The frequencies of Ff, FF and ff genotypes were 34.2%, 56.5% and 9.2%. The mean of bone mineral density in FF genotype was higher than other genotypes. Also in this genotype, mean of serum inflammatory cytokines was lower than other genotypes. The expressions of the VDR and osteoprotegrin were up regulated by 1, 25(OH2D3 in PBMC from participants with FF genotype. PBMC from healthy control comparison to osteoporotic patients had a clearly better response to vitamin D3 incubation."nConclusion: Inflammation may important role in osteoporosis whereas osteoporotic patients have elevated pro-inflamma­tory profile. This cytokine profile and gene expressions of VDR and Osteoprotegrin were different in VDR genotype groups.  

  6. 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.

  7. Role of Regulatory T Cells (Treg and the Treg Effector Molecule Fibrinogen-like Protein 2 in Alloimmunity and Autoimmunity

    Directory of Open Access Journals (Sweden)

    Andrzej Chruscinski

    2015-07-01

    Full Text Available CD4+CD25+Foxp3+ regulatory T cells (Treg are critical to the maintenance of immune tolerance. Treg are known to utilize a number of molecular pathways to control immune responses and maintain immune homeostasis. Fibrinogen-like protein 2 (FGL2 has been identified by a number of investigators as an important immunosuppressive effector of Treg, which exerts its immunoregulatory activity by binding to inhibitory FcγRIIB receptors expressed on antigen-presenting cells including dendritic cells, endothelial cells, and B cells. More recently, it has been suggested that FGL2 accounts for the immunosuppressive activity of a highly suppressive subset of Treg that express T cell immunoreceptor with Ig and ITIM domains (TIGIT. Here we discuss the important role of Treg and FGL2 in preventing alloimmune and autoimmune disease. The FGL2–FcγRIIB pathway is also known to be utilized by viruses and tumor cells to evade immune surveillance. Moving forward, therapies based on modulation of the FGL2–FcγRIIB pathway hold promise for the treatment of a wide variety of conditions ranging from autoimmunity to cancer.

  8. A method for selecting cis-acting regulatory sequences that respond to small molecule effectors

    Directory of Open Access Journals (Sweden)

    Allas Ülar

    2010-08-01

    Full Text Available Abstract Background Several cis-acting regulatory sequences functioning at the level of mRNA or nascent peptide and specifically influencing transcription or translation have been described. These regulatory elements often respond to specific chemicals. Results We have developed a method that allows us to select cis-acting regulatory sequences that respond to diverse chemicals. The method is based on the β-lactamase gene containing a random sequence inserted into the beginning of the ORF. Several rounds of selection are used to isolate sequences that suppress β-lactamase expression in response to the compound under study. We have isolated sequences that respond to erythromycin, troleandomycin, chloramphenicol, meta-toluate and homoserine lactone. By introducing synonymous and non-synonymous mutations we have shown that at least in the case of erythromycin the sequences act at the peptide level. We have also tested the cross-activities of the constructs and found that in most cases the sequences respond most strongly to the compound on which they were isolated. Conclusions Several selected peptides showed ligand-specific changes in amino acid frequencies, but no consensus motif could be identified. This is consistent with previous observations on natural cis-acting peptides, showing that it is often impossible to demonstrate a consensus. Applying the currently developed method on a larger scale, by selecting and comparing an extended set of sequences, might allow the sequence rules underlying the activity of cis-acting regulatory peptides to be identified.

  9. Evolution of B Cell Immunity

    OpenAIRE

    Parra, David; Takizawa, Fumio; Sunyer, J Oriol

    2013-01-01

    Two types of adaptive immune strategies are known to have evolved in vertebrates: the VLR-based system, which is present in jawless organisms and is mediated by VLRA and VLRB lymphocytes, and the BCR/TCR-based system, which is present in jawed species and is provided by B and T cell receptors expressed on B and T cells, respectively. Here we summarize features of B cells and their predecessors in the different animal phyla, focusing the review on B cells from jawed vertebrates. We point out t...

  10. Transgelin-2 in B-Cells Controls T-Cell Activation by Stabilizing T Cell - B Cell Conjugates

    Science.gov (United States)

    Chae, Myoung-Won; Kim, Hye-Ran; Kim, Chang-Hyun; Jun, Chang-Duk; Park, Zee-Yong

    2016-01-01

    The immunological synapse (IS), a dynamic and organized junction between T-cells and antigen presenting cells (APCs), is critical for initiating adaptive immunity. The actin cytoskeleton plays a major role in T-cell reorganization during IS formation, and we previously reported that transgelin-2, an actin-binding protein expressed in T-cells, stabilizes cortical F-actin, promoting T-cell activation in response to antigen stimulation. Transgelin-2 is also highly expressed in B-cells, although no specific function has been reported. In this study, we found that deficiency in transgelin-2 (TAGLN2-/-) in B-cells had little effect on B-cell development and activation, as measured by the expression of CD69, MHC class II molecules, and CD80/86. Nevertheless, in B-cells, transgelin-2 accumulated in the IS during the interaction with T-cells. These results led us to hypothesize that transgelin-2 may also be involved in IS stability in B-cells, thereby influencing T-cell function. Notably, we found that transgelin-2 deficiency in B-cells reduced T-cell activation, as determined by the release of IL-2 and interferon-γ and the expression of CD69. Furthermore, the reduced T-cell activation was correlated with reduced B-cell–T-cell conjugate formation. Collectively, these results suggest that actin stability in B-cells during IS formation is critical for the initiation of adaptive T-cell immunity. PMID:27232882

  11. Immune-inflammatory responses in atherosclerosis: Role of an adaptive immunity mainly driven by T and B cells.

    Science.gov (United States)

    Chistiakov, Dimitry A; Orekhov, Alexander N; Bobryshev, Yuri V

    2016-09-01

    Adaptive immune response plays an important role in atherogenesis. In atherosclerosis, the proinflammatory immune response driven by Th1 is predominant but the anti-inflammatory response mediated mainly by regulatory T cells is also present. The role of Th2 and Th17 cells in atherogenesis is still debated. In the plaque, other T helper cells can be observed such as Th9 and Th22 but is little is known about their impact in atherosclerosis. Heterogeneity of CD4(+) T cell subsets presented in the plaque may suggest for plasticity of T cell that can switch the phenotype dependening on the local microenvironment and activating/blocking stimuli. Effector T cells are able to recognize self-antigens released by necrotic and apoptotic vascular cells and induce a humoral immune reaction. Tth cells resided in the germinal centers help B cells to switch the antibody class to the production of high-affinity antibodies. Humoral immunity is mediated by B cells that release antigen-specific antibodies. A variety of B cell subsets were found in human and murine atherosclerotic plaques. In mice, B1 cells could spontaneously produce atheroprotective natural IgM antibodies. Conventional B2 lymphocytes secrete either proatherogenic IgG, IgA, and IgE or atheroprotective IgG and IgM antibodies reactive with oxidation-specific epitopes on atherosclerosis-associated antigens. A small population of innate response activator (IRA) B cells, which is phenotypically intermediate between B1 and B2 cells, produces IgM but possesses proatherosclerotic properties. Finally, there is a minor subset of splenic regulatory B cells (Bregs) that protect against atherosclerotic inflammation through support of generation of Tregs and production of anti-inflammatory cytokines IL-10 and TGF-β and proapoptotic molecules. PMID:27262513

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

    Science.gov (United States)

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

    2016-08-01

    The presence of inflammatory infiltrates with B cells, specifically plasma cells, is the hallmark of periodontitis lesions. The composition of these infiltrates in various stages of homeostasis and disease development is not well documented. Human tissue biopsies from sites with gingival health (n = 29), gingivitis (n = 8), and periodontitis (n = 21) as well as gingival tissue after treated periodontitis (n = 6) were obtained and analyzed for their composition of B cell subsets. Ag specificity, Ig secretion, and expression of receptor activator of NF-κB ligand and granzyme B were performed. Although most of the B cell subsets in healthy gingiva and gingivitis tissues were CD19(+)CD27(+)CD38(-) memory B cells, the major B cell component in periodontitis was CD19(+)CD27(+)CD38(+)CD138(+)HLA-DR(low) plasma cells, not plasmablasts. Plasma cell aggregates were observed at the base of the periodontal pocket and scattered throughout the gingiva, especially apically toward the advancing front of the lesion. High expression of CXCL12, a proliferation-inducing ligand, B cell-activating factor, IL-10, IL-6, and IL-21 molecules involved in local B cell responses was detected in both gingivitis and periodontitis tissues. Periodontitis tissue plasma cells mainly secreted IgG specific to periodontal pathogens and also expressed receptor activator of NF-κB ligand, a bone resorption cytokine. Memory B cells resided in the connective tissue subjacent to the junctional epithelium in healthy gingiva. This suggested a role of memory B cells in maintaining periodontal homeostasis. PMID:27335500

  13. A versatile method to design stem-loop primer-based quantitative PCR assays for detecting small regulatory RNA molecules.

    Directory of Open Access Journals (Sweden)

    Zsolt Czimmerer

    Full Text Available Short regulatory RNA-s have been identified as key regulators of gene expression in eukaryotes. They have been involved in the regulation of both physiological and pathological processes such as embryonal development, immunoregulation and cancer. One of their relevant characteristics is their high stability, which makes them excellent candidates for use as biomarkers. Their number is constantly increasing as next generation sequencing methods reveal more and more details of their synthesis. These novel findings aim for new detection methods for the individual short regulatory RNA-s in order to be able to confirm the primary data and characterize newly identified subtypes in different biological conditions. We have developed a flexible method to design RT-qPCR assays that are very sensitive and robust. The newly designed assays were tested extensively in samples from plant, mouse and even human formalin fixed paraffin embedded tissues. Moreover, we have shown that these assays are able to quantify endogenously generated shRNA molecules. The assay design method is freely available for anyone who wishes to use a robust and flexible system for the quantitative analysis of matured regulatory RNA-s.

  14. Bruton tyrosine kinase inhibitors: a promising novel targeted treatment for B cell lymphomas

    OpenAIRE

    Aalipour, Amin; Advani, Ranjana H.

    2013-01-01

    Constitutive or aberrant signalling of the B cell receptor signalling cascade has been implicated in the propagation and maintenance of a variety of B cell malignancies. Small molecule inhibitors of Bruton tyrosine kinase (BTK), a protein early in this cascade and specifically expressed in B cells, have emerged as a new class of targeted agents. There are several BTK inhibitors, including ONO-WG-307, LFM-A13, dasatinib, CC-292, and PCI-32765 (ibrutinib), in preclinical and/or clinical develop...

  15. Effect of ionizing radiation on expressions of regulatory T cells and related molecules in mice spleen

    International Nuclear Information System (INIS)

    Objective: To observe the changes in expressions of spleen regulatory T cells (Tregs) and the related factor forkhead box protein-3 (Foxp3) after irradiation with different doses of X-ray in mice at different times, and to elaborate the effects of X-rays on regulatory T cells and Foxp3. Methods: 112 male ICR mice were randomly divided into 2 groups and irradiated by X-rays at the doses of 0.075 and 2 Gy, respectively. The mice were killed at 0, 4, 8, 16, 24, 48, and 72 h post-irradiation and the spleens removed. Flow cytometry was used to detect the percentage of CD4 + CD25 + Treg and protein expression of (Foxp3), and RT-PCR was used to exmiamine the mRNA expression of Fox3. Results: Compared with those before irradiation, the CD4 + CD25 + Treg positive rates began to increase and peaked at 8 h post-irradiation with 0.075 Gy at 8, 16, 24, 72 h (t=8.73, 10.55, 4.21, 4.65, P<0.05) and 2 Gy at 8, 16, 48, 72 h (t=4.65, 4.28, 3.71, 2.88, P<0.05), and then slightly decreased, but still remained at high levels. The mRNA protein levels of Fox3 did not change significantly after exposure to the dose of 0.075 Gy, but began to significantly increase at 8 h after exposure to the dose of 2 Gy. However, the Fox3 protein level began to increase 4 h post-irradiation, peaked at 16 h, and then slightly decreased, but still remained at high levels (t=2.59, 3.37, 3.70, 3.20, P<0.05). Conclusions: The changes in expressions of Tregs and Foxp3 after high- and low-dose X-ray irradiation may be used to explain the differences in immune effects induced ionizing radiation at different doses. (authors)

  16. CEACAM1 mediates B cell aggregation in central nervous system autoimmunity.

    Science.gov (United States)

    Rovituso, Damiano M; Scheffler, Laura; Wunsch, Marie; Kleinschnitz, Christoph; Dörck, Sebastian; Ulzheimer, Jochen; Bayas, Antonios; Steinman, Lawrence; Ergün, Süleyman; Kuerten, Stefanie

    2016-01-01

    B cell aggregates in the central nervous system (CNS) have been associated with rapid disease progression in patients with multiple sclerosis (MS). Here we demonstrate a key role of carcinoembryogenic antigen-related cell adhesion molecule1 (CEACAM1) in B cell aggregate formation in MS patients and a B cell-dependent mouse model of MS. CEACAM1 expression was increased on peripheral blood B cells and CEACAM1(+) B cells were present in brain infiltrates of MS patients. Administration of the anti-CEACAM1 antibody T84.1 was efficient in blocking aggregation of B cells derived from MS patients. Along these lines, application of the monoclonal anti-CEACAM1 antibody mCC1 was able to inhibit CNS B cell aggregate formation and significantly attenuated established MS-like disease in mice in the absence of any adverse effects. CEACAM1 was co-expressed with the regulator molecule T cell immunoglobulin and mucin domain -3 (TIM-3) on B cells, a novel molecule that has recently been described to induce anergy in T cells. Interestingly, elevated coexpression on B cells coincided with an autoreactive T helper cell phenotype in MS patients. Overall, these data identify CEACAM1 as a clinically highly interesting target in MS pathogenesis and open new therapeutic avenues for the treatment of the disease. PMID:27435215

  17. Intravenous immunoglobulin replacement therapy in common variable immunodeficiency induces B cell depletion through differentiation into apoptosis-prone CD21(low) B cells.

    Science.gov (United States)

    Mitrevski, Milica; Marrapodi, Ramona; Camponeschi, Alessandro; Lazzeri, Cristina; Todi, Laura; Quinti, Isabella; Fiorilli, Massimo; Visentini, Marcella

    2014-12-01

    Intravenous immunoglobulin (IVIG), besides its use as replacement therapy in patients with antibody deficiencies, is broadly used as an immunomodulatory agent for the treatment of autoimmune and inflammatory disorders. The mechanisms of action of IVIG include Fc receptor blockade, inhibition of cytokines and growth factors, modulation of macrophages and dendritic cells, enhancement of regulatory T cells, and modulation of B cells through the FcγRIIB receptor and CD22. Recent studies suggest that in vitro exposure of human B cells to IVIG determines functional changes reminiscent of anergy and that IVIG treatment of patients with common variable immunodeficiency (CVID) induces in B cells ERK activation, a feature of anergy. Here, we show that IVIG therapy drives the B cells of patients with CVID to down-regulate CD21 expression and to assume the peculiar phenotype of the anergic-like, apoptosis-prone CD21(low) B cells that are spontaneously expanded in a subset of CVID and in some other immunological disorders. The CD21(low) B cells newly generated after IVIG infusion undergo spontaneous apoptosis upon in vitro culture. Furthermore, IVIG infusion is rapidly followed by a significant, although discrete, decrease in the number of circulating B cells, but not of T cells or of natural killer cells. These findings suggest that IVIG therapy may constrain antibody responses by inducing B cell depletion through differentiation into CD21(low) B cells that undergo accelerated apoptosis. PMID:25407649

  18. Immunomodulatory effect of Mesenchymal Stem Cells on B cells

    Directory of Open Access Journals (Sweden)

    Marcella eFranquesa

    2012-07-01

    Full Text Available The research on T cell immunosuppression therapies has attracted most of the attention in clinical transplantation. However, B cells and humoral immune responses are increasingly acknowledged as crucial mediators of chronic allograft rejection. Indeed, humoral immune responses can lead to renal allograft rejection even in patients whose cell-mediated immune responses are well controlled. On the other hand, newly studied B cell subsets with regulatory effects have been linked to tolerance achievement in transplantation. Better understanding of the regulatory and effector B cell responses may therefore lead to new therapeutic approaches.Mesenchymal Stem Cells (MSC are arising as a potent therapeutic tool in transplantation due to their regenerative and immunomodulatory properties. The research on MSCs has mainly focused on their effects on T cells and although data regarding the modulatory effects of MSCs on alloantigen-specific humoral response in humans is scarce, it has been demonstrated that MSCs significantly affect B cell functioning. In the present review we will analyze and discuss the results in this field.

  19. Selective loss of B-cell phenotype in lymphocyte predominant Hodgkin lymphoma.

    NARCIS (Netherlands)

    Tedoldi, S.; Mottok, A.; Ying, J.; Paterson, J.C.; Cui, Y.; Facchetti, F.; Krieken, J.H.J.M. van; Ponzoni, M.; Ozkal, S.; Masir, N.; Natkunam, Y.; Pileri, S.; Hansmann, M.L.; Mason, D.; Tao, Q.; Marafioti, T.

    2007-01-01

    The neoplastic Reed-Sternberg cells characteristic of classical Hodgkin's lymphoma (cHL) are of B-cell origin but they almost always show striking loss of a range of B-cell-associated molecules. In contrast, the neoplastic cells found in lymphocyte predominant Hodgkin's lymphoma (LPHL) (L&H cells) a

  20. New helping friends for B cells.

    OpenAIRE

    Cerutti, Andrea; Puga, Irene; Cols, Montserrat

    2012-01-01

    Over the past decade, a growing recognition of the importance of neutralizing antibodies in host defense combined with the success of B-cell depletion therapies in treating autoimmune disorders has led to an increased focus on better understanding the pathways underpinning B-cell antibody production. In general, B cells require cognate interaction with T helper cells in the germinal center of lymphoid follicles to generate protective antibodies. However, recent evidence shows that B cells rec...

  1. Tick-borne encephalitis (TBE) and hepatitis B nonresponders feature different immunologic mechanisms in response to TBE and influenza vaccination with involvement of regulatory T and B cells and IL-10.

    Science.gov (United States)

    Garner-Spitzer, Erika; Wagner, Angelika; Paulke-Korinek, Maria; Kollaritsch, Herwig; Heinz, Franz X; Redlberger-Fritz, Monika; Stiasny, Karin; Fischer, Gottfried F; Kundi, Michael; Wiedermann, Ursula

    2013-09-01

    Low responsiveness/nonresponsiveness is characterized by an insufficient immune response upon primary and/or booster vaccination and affects 1-10% of vaccinees. In the current study, we aimed to investigate whether nonresponsiveness is an Ag/vaccine-specific phenomenon and to clarify underlying immunological mechanisms. Nonresponders to tick-borne encephalitis (TBE) or hepatitis B Ag with a history of previous TBE vaccinations were booster vaccinated with TBE and influenza vaccine and compared with TBE high responders in terms of humoral and cellular immune response. Postboosters in TBE high responder existing TBE titers increased, and solid humoral responses to influenza vaccine were induced. In TBE nonresponders, low to undetectable prevaccination TBE titers remained low, whereas sufficient influenza Abs were induced. In both TBE groups, a positive correlation of humoral and cellular immune response was seen as high/low TBE titers were associated with sufficient/lack of Ag-specific T cell proliferation. Furthermore, responses to influenza were robust in terms of Abs and cytokine production. In contrast, in hepatitis B nonresponders, sufficient humoral responses to TBE and influenza Ags were induced despite lacking specific IL-2 and IFN-γ production. Importantly, these patients showed high IL-10 baseline levels in vitro. HLA-DR subtypes associated with hepatitis B nonresponsiveness were overrepresented in this group, and high IL-10 levels were linked to these subtypes. Whereas TBE and hepatitis B nonresponders had increased IL-10-producing FOXP3(+) T regulatory cells upon vaccination, only in hepatitis B nonresponders, showing elevated prevaccination IL-10 levels, a prominent population of B regulatory cells was detected. We conclude that immunological pathways of nonresponsiveness follow different patterns depending both on vaccine Ag and genetic predisposition of the vaccinee. PMID:23872054

  2. Modulation of Pantothenate Kinase 3 Activity by Small Molecules that Interact with the Substrate/Allosteric Regulatory Domain

    Energy Technology Data Exchange (ETDEWEB)

    Leonardi, Roberta; Zhang, Yong-Mei; Yun, Mi-Kyung; Zhou, Ruobing; Zeng, Fu-Yue; Lin, Wenwei; Cui, Jimmy; Chen, Taosheng; Rock, Charles O.; White, Stephen W.; Jackowski, Suzanne (SJCH)

    2010-09-27

    Pantothenate kinase (PanK) catalyzes the rate-controlling step in coenzyme A (CoA) biosynthesis. PanK3 is stringently regulated by acetyl-CoA and uses an ordered kinetic mechanism with ATP as the leading substrate. Biochemical analysis of site-directed mutants indicates that pantothenate binds in a tunnel adjacent to the active site that is occupied by the pantothenate moiety of the acetyl-CoA regulator in the PanK3 acetyl-CoA binary complex. A high-throughput screen for PanK3 inhibitors and activators was applied to a bioactive compound library. Thiazolidinediones, sulfonylureas and steroids were inhibitors, and fatty acyl-amides and tamoxifen were activators. The PanK3 activators and inhibitors either stimulated or repressed CoA biosynthesis in HepG2/C3A cells. The flexible allosteric acetyl-CoA regulatory domain of PanK3 also binds the substrates, pantothenate and pantetheine, and small molecule inhibitors and activators to modulate PanK3 activity.

  3. Anatomy of a new B-cell-specific enhancer.

    OpenAIRE

    Koch, W; Benoist, C.; Mathis, D

    1989-01-01

    The major histocompatibility complex class II molecules, like the immunoglobulins, are prominent B-lymphocyte markers. Herein, we describe a B-cell-specific enhancer associated with the murine class II gene, Ek alpha. This enhancer has a complex anatomy that suggests interactions between remotely spaced elements. Of particular interest is the finding that two CCAAT boxes spaced one kilobase apart are important for enhancer activity. Somewhat surprisingly, the E alpha and immunoglobulin enhanc...

  4. Innate B cells: oxymoron or validated concept?

    OpenAIRE

    Ware, Carl F.; Chris Benedict

    2012-01-01

    B lymphocytes promote the initial innate interferon response to viral pathogens without the need for antigen receptor activation. B cell dependent IFN production requires the cytokine, lymphotoxin-β. The LTβ pathway is well known to regulate lymphoid organogenesis and homeostasis by differentiating stromal cells and macrophages. However, in response to viral pathogens these same B cell-regulated populations rapidly produce type 1 interferons. Thus, B cells act as innate effector cells via LTβ...

  5. B-Cell Hematologic Malignancy Vaccination Registry

    Science.gov (United States)

    2015-09-15

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

  6. Tolerogenicity of resting and activated B cells

    OpenAIRE

    1994-01-01

    Antigen presentation by resting splenic B cells has been shown previously to induce T helper 1 cell (Th1) anergy. In contrast to expectations, it was found here that B cells treated with F(ab')2 goat anti-mouse immunoglobulin (IgM) for 24 or 48 h also presented antigen (Ag) to Th1 cells in a manner that induced dramatic Ag-specific proliferative inactivation. The tolerogenicity of the anti-Ig-treated B cells was consistent with the observation that these B cells were only slightly more effici...

  7. Role of Calcium Signaling in B Cell Activation and Biology.

    Science.gov (United States)

    Baba, Yoshihiro; Kurosaki, Tomohiro

    2016-01-01

    Increase in intracellular levels of calcium ions (Ca2+) is one of the key triggering signals for the development of B cell response to the antigen. The diverse Ca2+ signals finely controlled by multiple factors participate in the regulation of gene expression, B cell development, and effector functions. B cell receptor (BCR)-initiated Ca2+ mobilization is sourced from two pathways: one is the release of Ca2+ from the intracellular stores, endoplasmic reticulum (ER), and other is the prolonged influx of extracellular Ca2+ induced by depleting the stores via store-operated calcium entry (SOCE) and calcium release-activated calcium (CRAC) channels. The identification of stromal interaction molecule 1(STIM1), the ER Ca2+ sensor, and Orai1, a key subunit of the CRAC channel pore, has now provided the tools to understand the mode of Ca2+ influx regulation and physiological relevance. Herein, we discuss our current understanding of the molecular mechanisms underlying BCR-triggered Ca2+ signaling as well as its contribution to the B cell biological processes and diseases. PMID:26369772

  8. B-cell subsets, signaling and their roles in secretion of autoantibodies.

    Science.gov (United States)

    Iwata, S; Tanaka, Y

    2016-07-01

    B cells play a pivotal role in the pathogenesis of autoimmune diseases. In patients with systemic lupus erythematosus (SLE), the percentages of plasmablasts and IgD(-)CD27(-) double-negative memory B cells in peripheral blood are significantly increased, while IgD(+)CD27(+) IgM memory B cells are significantly decreased compared to healthy donors. The phenotypic change is significantly associated with disease activity and concentration of autoantibodies. Treatment of B-cell depletion using rituximab results in the reconstitution of peripheral B cells in SLE patients with subsequent improvement in disease activity. Numerous studies have described abnormalities in B-cell receptor (BCR)-mediated signaling in B cells of SLE patients. Since differences in BCR signaling are considered to dictate the survival or death of naïve and memory B cells, aberrant BCR signal can lead to abnormality of B-cell subsets in SLE patients. Although Syk and Btk function as key molecules in BCR signaling, their pathological role in SLE remains unclear. We found that Syk and Btk do not only transduce activation signal through BCR, but also mediate crosstalk between BCR and Toll-like receptor (TLR) as well as BCR and JAK-STAT pathways in human B cells in vitro. In addition, pronounced Syk and Btk phosphorylation was observed in B cells of patients with active SLE compared to those of healthy individuals. The results suggest the involvement of Syk and Btk activation in abnormalities of BCR-mediated signaling and B-cell phenotypes during the pathological process of SLE and that Syk, Btk and JAK are potential therapeutic targets in SLE. PMID:27252261

  9. Ikaros and Aiolos Inhibit Pre-B-Cell Proliferation by Directly Suppressing c-Myc Expression▿

    OpenAIRE

    Ma, Shibin; Pathak, Simanta; Mandal, Malay; Trinh, Long; Clark, Marcus R.; Lu, Runqing

    2010-01-01

    Pre-B-cell expansion is driven by signals from the interleukin-7 receptor and the pre-B-cell receptor and is dependent on cyclin D3 and c-Myc. We have shown previously that interferon regulatory factors 4 and 8 induce the expression of Ikaros and Aiolos to suppress pre-B-cell proliferation. However, the molecular mechanisms through which Ikaros and Aiolos exert their growth inhibitory effect remain to be determined. Here, we provide evidence that Aiolos and Ikaros bind to the c-Myc promoter i...

  10. Integration of B cells and CD8+ T in the protective regulation of systemic epithelial inflammation

    Science.gov (United States)

    Wei, Bo; McPherson, Michael; Turovskaya, Olga; Velazquez, Peter; Fujiwara, Daisuke; Brewer, Sarah; Braun, Jonathan

    2008-01-01

    Mechanisms that control abnormal CD4+ T cell-mediated tissue damage are a significant factor in averting and resolving chronic inflammatory epithelial diseases. B cells can promote such immunoregulation, and this is thought to involve interaction with MHC II- or CD1-restricted regulatory T cells. The purpose of this study is to genetically define the interacting cells targeted by protective B cells, and to elucidate their regulatory mechanisms in CD4+ T cell inflammation. Transfer of Gαi2−/− CD3+ T cells into lymphopenic mice causes a dose-dependent multi-organ inflammatory disease including the skin, intestine, and lungs. Disease activity is associated with elevated levels of serum TNF-α and IFN-γ and an activated IL-17 producing CD4+ T cell population. Mesenteric node B cells from wild type mice suppress disease activity, serum cytokine expression, and levels of CD4+ T cells producing TNF-α, IFN-γ, and IL-17. The protective function of B cells requires genetic sufficiency of IL-10, MHC I and TAP1. Regulatory B cells induce the expansion and activation of CD8+ T cells, which is correlated with disease protection. These results demonstrate that CD8+ T cells can ameliorate lymphopenic systemic inflammatory disease, through peptide/MHC I-dependent B cell interaction. PMID:18282744

  11. KLF2--a negative regulator of pre-B cell clonal expansion and B cell activation.

    Directory of Open Access Journals (Sweden)

    Rebecca Winkelmann

    Full Text Available Maturation as well as antigen-dependent activation of B cells is accompanied by alternating phases of proliferation and quiescence. We and others have previously shown that Krüppel-like factor 2 (KLF2, a regulator of T cell quiescence and migration, is upregulated in small resting precursor (pre-B cells after assembly of the immature pre-B cell receptor (pre-BCR and is downregulated upon antigen-induced proliferation of mature B cells. These findings suggest that KLF2, besides its function in maintaining follicular B cell identity, peripheral B cell homeostasis and homing of antigen-specific plasma cells to the bone marrow, also controls clonal expansion phases in the B cell lineage. Here, we demonstrate that enforced expression of KLF2 in primary pre-B cells results in a severe block of pre-BCR-induced proliferation, upregulation of the cell cycle inhibitors p21 and p27 and downregulation of c-myc. Furthermore, retroviral KLF2 transduction of primary B cells impairs LPS-induced activation, favors apoptosis and results in reduced abundance of factors, such as AID, IRF4 and BLIMP1, that control the antigen-dependent phase of B cell activation and plasma cell differentiation. Hence, we conclude that KLF2 is not only a key player in terminating pre-B cell clonal expansion but also a potent suppressor of B cell activation.

  12. Expression of PD-1 Molecule on Regulatory T Lymphocytes in Patients with Insulin-Dependent Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Valentina Perri

    2015-09-01

    Full Text Available Type 1 diabetes is caused by autoreactive T cells that destroy pancreatic beta cells. Animal models suggested that a CD4+CD25+ population has a regulatory function capable of preventing activation and effector functions of autoreactive T cells. However, the role of CD4+CD25high T cells in autoimmunity and their molecular mechanisms remain the subject of investigation. We therefore evaluated T regulatory cell frequencies and their PD-1 expression in the peripheral blood of long-standing diabetics under basal conditions and after CD3/CD28 stimulation. Under basal conditions, the percentages of T regulatory cells were significantly higher while that of T effector cells were significantly lower in patients than in controls. The ratio of regulatory to effector T cells was higher in patients than that in controls, suggesting that T regulatory cells were functional in patients. Percentages of total PD-1+, PD-1low and PD-1high expressing T regulatory cells did not change in patients and in controls. After stimulation, a defect in T regulatory cell proliferation was observed in diabetics and the percentages of total PD-1+, PD-1low and PD-1high expressing cells were lower in patients. Our data suggest a defective activation of T regulatory cells in long-standing diabetics due to a lower expression of PD-1 on their surface.

  13. Regulatory B cells in allergic asthma and schistosomiasis : controlling inflammation

    NARCIS (Netherlands)

    Vlugt, Elisabeth Petronella Maria van der

    2015-01-01

    In the last few decades, childhood allergy has alarmingly increased to epidemic levels in industrialized countries. Conversely, chronic helminth infections, which are highly prevalent in developing countries, are negatively associated with allergic disorders. The work in this thesis revealed that, u

  14. 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.

  15. Targeting HIV-1 Envelope Glycoprotein Trimers to B Cells by Using APRIL Improves Antibody Responses

    OpenAIRE

    Melchers M; Bontjer I; Tong T; Chung NP; Klasse PJ; Eggink D; Montefiori DC; Gentile M; Cerutti A; Olson WC; Berkhout B; Binley JM; Moore JP; Sanders RW

    2012-01-01

    An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality of the antibodies raised against the viral envelope glycoprotein complex (Env). We hypothesized that targeting Env vaccines directly to B cells, by fusing them to molecules that bind and activate these cells, would improve Env-specific antibody responses. Therefore, we fused trimeric Env gp140 to A PRoliferation-Inducing Ligand (APRIL), B-cell Activating Factor (BAFF), and CD40 Ligand (CD40L). The...

  16. Targeting neoplastic B cells and harnessing microenvironment: the “double face” of ibrutinib and idelalisib

    OpenAIRE

    Maffei, Rossana; Fiorcari, Stefania; Martinelli, Silvia; Potenza, Leonardo; Luppi, Mario; Marasca, Roberto

    2015-01-01

    Tyrosine kinase inhibitors (TKIs) targeting signaling molecules downstream B cell receptor (BCR) are powerfully spreading in the therapeutic landscape of B cell lymphoproliferative disease, due to a manageable toxicity profile and encouraging clinical effectiveness. In particular, ibrutinib, previously called PCI-32765, is a potent inhibitor of Bruton tyrosine kinase (Btk), recently approved for the treatment of relapsed mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL). Moreo...

  17. Bacterial regulatory networks—from self-organizing molecules to cell shape and patterns in bacterial communities

    OpenAIRE

    Hengge, Regine; Sourjik, Victor

    2013-01-01

    The ESF–EMBO Conference on ‘Bacterial Networks' was held in March, 2013. It brought together molecular microbiologists, bacteral systems biologists and synthetic biologists to discuss the architecture, function and dynamics of regulatory networks in bacteria.

  18. Adaptive Response of T and B Cells in Atherosclerosis.

    Science.gov (United States)

    Ketelhuth, Daniel F J; Hansson, Göran K

    2016-02-19

    Atherosclerosis is a chronic inflammatory disease that is initiated by the retention and accumulation of cholesterol-containing lipoproteins, particularly low-density lipoprotein, in the artery wall. In the arterial intima, lipoprotein components that are generated through oxidative, lipolytic, and proteolytic activities lead to the formation of several danger-associated molecular patterns, which can activate innate immune cells as well as vascular cells. Moreover, self- and non-self-antigens, such as apolipoprotein B-100 and heat shock proteins, can contribute to vascular inflammation by triggering the response of T and B cells locally. This process can influence the initiation, progression, and stability of plaques. Substantial clinical and experimental data support that the modulation of adaptive immune system may be used for treating and preventing atherosclerosis. This may lead to the development of more selective and less harmful interventions, while keeping host defense mechanisms against infections and tumors intact. Approaches such as vaccination might become a realistic option for cardiovascular disease, especially if they can elicit regulatory T and B cells and the secretion of atheroprotective antibodies. Nevertheless, difficulties in translating certain experimental data into new clinical therapies remain a challenge. In this review, we discuss important studies on the function of T- and B-cell immunity in atherosclerosis and their manipulation to develop novel therapeutic strategies against cardiovascular disease. PMID:26892965

  19. B cell remote-handled waste shipment cask alternatives study

    International Nuclear Information System (INIS)

    The decommissioning of the 324 Facility B Cell includes the onsite transport of grouted remote-handled radioactive waste from the 324 Facility to the 200 Areas for disposal. The grouted waste has been transported in the leased ATG Nuclear Services 3-82B Radioactive Waste Shipping Cask (3-82B cask). Because the 3-82B cask is a U.S. Nuclear Regulatory Commission (NRC)-certified Type B shipping cask, the lease cost is high, and the cask operations in the onsite environment may not be optimal. An alternatives study has been performed to develop cost and schedule information on alternative waste transportation systems to assist in determining which system should be used in the future. Five alternatives were identified for evaluation. These included continued lease of the 3-82B cask, fabrication of a new 3-82B cask, development and fabrication of an onsite cask, modification of the existing U.S. Department of Energy-owned cask (OH-142), and the lease of a different commercially available cask. Each alternative was compared to acceptance criteria for use in the B Cell as an initial screening. Only continued leasing of the 3-82B cask, fabrication of a new 3-82B cask, and the development and fabrication of an onsite cask were found to meet all of the B Cell acceptance criteria

  20. B-cell waste classification sampling plan

    Energy Technology Data Exchange (ETDEWEB)

    HOBART, R.L.

    1999-11-20

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

  1. B-cell waste classification sampling plan

    International Nuclear Information System (INIS)

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

  2. Dimethyl fumarate treatment of relapsing-remitting multiple sclerosis influences B-cell subsets

    Science.gov (United States)

    Lundy, Steven K.; Wu, Qi; Wang, Qin; Dowling, Catherine A.; Taitano, Sophina H.; Mao, Guangmei

    2016-01-01

    Objective: To test the hypothesis that dimethyl fumarate (Tecfidera, BG-12) affects B-cell subsets in patients with relapsing-remitting multiple sclerosis (RRMS). Methods: Peripheral blood B cells were compared for surface marker expression in patients with RRMS prior to initiation of treatment, after 4–6 months, and at more than 1 year of treatment with BG-12. Production of interleukin (IL)–10 by RRMS patient B cells was also analyzed. Results: Total numbers of peripheral blood B lymphocytes declined after 4–6 months of BG-12 treatment, due to losses in both the CD27+ memory B cells and CD27neg B-cell subsets. Some interpatient variability was observed. In contrast, circulating CD24highCD38high (T2-MZP) B cells increased in percentage in the majority of patients with RRMS after 4–6 months and were present in higher numbers in all of the patients after 12 months of treatment. The CD43+CD27+ B-1 B cells also increased at the later time point in most patients but were unchanged at 4–6 months compared to pretreatment levels. Purified B cells from 7 of the 9 patients with RRMS tested after 4–6 months of treatment were able to produce IL-10 following CD40 ligand stimulation, and the amount corresponded with the combined levels of T2-MZP and B-1 B cells in the sample. None of the patients with RRMS in this study have had a relapse while taking BG-12. Conclusions: These data suggest that BG-12 differentially affects B-cell subsets in patients with RRMS, resulting in increased numbers of circulating B lymphocytes with regulatory capacity. PMID:27006972

  3. 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. PMID:27424222

  4. 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.

  5. 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

    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...

  6. Increased levels of (class switched) memory B cells in peripheral blood of current smokers

    NARCIS (Netherlands)

    Brandsma, Corry-Anke; Hylkema, Machteld N.; Geerlings, Marie; van Geffen, Wouter; Postma, Dirkje S.; Timens, Wim; Kerstjens, Huib A. M.

    2009-01-01

    There is increasing evidence that a specific immune response contributes to the pathogenesis of COPD. B-cell follicles are present in lung tissue and increased anti-elastin titers have been found in plasma of COPD patients. Additionally, regulatory T cells (Tregs) have been implicated in its pathoge

  7. Exosomes from B cells and Dendritic cells: mechanisms of formation, secretion and targeting

    NARCIS (Netherlands)

    Buschow, S.I.

    2006-01-01

    Many cell types, including dendritic cells (DC) and B cells, secrete small vesicles called exosomes. Exosomes from immune cells are thought to have immuno-regulatory functions but their precise role remains unresolved. The aim of the studies presented in this thesis was to get more insight into the

  8. Specific blockade by CD54 and MHC II of CD40-mediated signaling for B cell proliferation and survival

    DEFF Research Database (Denmark)

    Doyle, I S; Hollmann, C A; Crispe, I N;

    2001-01-01

    Regulation of B lymphocyte proliferation is critical to maintenance of self-tolerance, and intercellular interactions are likely to signal such regulation. Here, we show that coligation of either the adhesion molecule ICAM-1/CD54 or MHC II with CD40 inhibited cell cycle progression and promoted...... apoptosis of mouse splenic B cells. This resulted from specific blockade of NF-kappa B induction, which normally inhibits apoptosis. LPS- or B cell receptor (BCR)-induced proliferation was not inhibited by these treatments, and mAb-induced association of CD40 with other B cell surface molecules did not have...

  9. 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.

  10. Cyclin Dl expression in B-cell non Hodgkin lymphoma.

    Science.gov (United States)

    Aref, Salah; Mossad, Y; El-Khodary, T; Awad, M; El-Shahat, E

    2006-10-01

    Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over-expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the effect of its expression on clinical behavior and outcome in B-cell Non-Hodgkin lymphoma (NHL). In this study, we investigated the expression of cyclin Dl in group of patients with NHL and correlated the results with the clinical and laboratory data. The degree of expression of cyclin Dl protein was evaluated by flow cytometry in a group of NHL patients (n = 46) and in normal control group (n = 10). Cyclin Dl over expression was detected in 10 out of 46 (21.7%) patients; they were 5/5-mantle cell lymphoma (MCL) (100%) and 5/28 large B-cell lymphoma (17.8%). All other NHL subtypes showed normal cyclin D1 expression. The clinical signs (hepatomegaly, splenomegaly and B-symptoms, clinical staging) and laboratory data (hemoglobin, white cell count (WBCs), platelet count, and bone marrow infiltration) were not significantly different between NHL subgroup with cyclin Dl over expression and that with normal cyclin Dl expression. Serum lactic dehydrogenase (LDH) levels and lymphadenopathy were significantly higher in NHL group with cyclin D1 over expression as compared to those without. Also, cyclin D1 over expression is associated with poor outcome of NHL patients. Cyclin Dl over expression was evident among all cases of MCL and few cases of large B-cell lymphoma. Cyclin Dl over expression might be used as adjuvant tool for diagnosis of MCL; has role in NHL biology and is bad prognostic index in NHL. PMID:17607588

  11. 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.

  12. 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.

  13. Levels of expression of CD19 and CD20 in chronic B cell leukaemias.

    Science.gov (United States)

    Ginaldi, L; De Martinis, M; Matutes, E; Farahat, N; Morilla, R; Catovsky, D

    1998-01-01

    AIMS: To investigate whether the antigen levels of the B cell lineage markers CD19 and CD20 can distinguish between normal and neoplastic B cells or characterise distinct expression patterns among the chronic B cell leukaemias. METHODS: Peripheral blood cells from 70 patients with B cell disorders and 17 healthy donors were analysed by quantitative flow cytometry. Direct immunofluorescence staining was performed with phycoerythrin conjugated CD19 and CD20 monoclonal antibodies. Standard microbeads with different capacities to bind mouse immunoglobulins were used to convert the mean fluorescence intensity (MFI) values into number of antigen molecules/cell, expressed as antibody binding capacity (ABC). RESULTS: CD19 and CD20 ABC values in leukaemic B cells differed from those of normal blood B lymphocytes. The results identified distinct profiles of CD19 and CD20 expression in the various types of B cell leukaemias. In all leukaemias studied except hairy cell leukaemia (HCL), CD19 expression was significantly lower than the mean (SD) value in normal B cells (22 (7) x 10(3) molecules/cell), as follows: chronic lymphocytic leukaemia (CLL), 13 (7) x 10(3); B prolymphocytic leukaemia (B-PLL), 16 (9) x 10(3); splenic lymphoma with villous lymphocytes (SLVL), 15 (11) x 10(3); mantle cell lymphoma (MCL), 10 (7) x 10(3). In HCL there was strong CD19 expression (38 (16) x 10(3)). In contrast, the level of expression of membrane CD20 was higher than the mean (SD) value in normal B cells (94 (16) x 10(3) molecules/cell) in MCL (123 (51) x 10(3)); B-PLL (129 (47) x 10(3)); SLVL (167 (72) x 10(3)); and HCL (312 (110) x 10(3)); while it was significantly lower (65 (11) x 10(3)) in CLL compared with normal B cells and the other B cell leukaemias. CONCLUSIONS: Quantitative determination of CD19 and CD20 may provide useful diagnostic information for the study of B lymphoproliferative disorders. PMID:9708202

  14. Targeting Syk-activated B cells in murine and human chronic graft-versus-host disease.

    Science.gov (United States)

    Flynn, Ryan; Allen, Jessica L; Luznik, Leo; MacDonald, Kelli P; Paz, Katelyn; Alexander, Kylie A; Vulic, Ante; Du, Jing; Panoskaltsis-Mortari, Angela; Taylor, Patricia A; Poe, Jonathan C; Serody, Jonathan S; Murphy, William J; Hill, Geoffrey R; Maillard, Ivan; Koreth, John; Cutler, Corey S; Soiffer, Robert J; Antin, Joseph H; Ritz, Jerome; Chao, Nelson J; Clynes, Raphael A; Sarantopoulos, Stefanie; Blazar, Bruce R

    2015-06-25

    Novel therapies for chronic graft-versus-host disease (cGVHD) are needed. Aberrant B-cell activation has been demonstrated in mice and humans with cGVHD. Having previously found that human cGVHD B cells are activated and primed for survival, we sought to further evaluate the role of the spleen tyrosine kinase (Syk) in cGVHD in multiple murine models and human peripheral blood cells. In a murine model of multiorgan system, nonsclerodermatous disease with bronchiolitis obliterans where cGVHD is dependent on antibody and germinal center (GC) B cells, we found that activation of Syk was necessary in donor B cells, but not T cells, for disease progression. Bone marrow-specific Syk deletion in vivo was effective in treating established cGVHD, as was a small-molecule inhibitor of Syk, fostamatinib, which normalized GC formation and decreased activated CD80/86(+) dendritic cells. In multiple distinct models of sclerodermatous cGVHD, clinical and pathological disease manifestations were not eliminated when mice were therapeutically treated with fostamatinib, though both clinical and immunologic effects could be observed in one of these scleroderma models. We further demonstrated that Syk inhibition was effective at inducing apoptosis of human cGVHD B cells. Together, these data demonstrate a therapeutic potential of targeting B-cell Syk signaling in cGVHD. PMID:25852057

  15. The mouse B cell repertoire : antibody specificities and immunoglobulin (sub) class distribution

    OpenAIRE

    Hooijkaas, Herbert

    1985-01-01

    textabstractThe total number of different immunoglobulin (I g) molecules that the immune system produces is often called the antibody specificity repertoire orB cell repertoire (Chapter 1). This repertoire can be subdivided into three categories: the potential, the available and the actual repertoires. The potential repertoire is determined by the number, structure and mechanisms of expression of the germl ine genes encoding lg molecules plus the possible somatic variants derived from them an...

  16. Comparison of human B cell activation by TLR7 and TLR9 agonists

    Directory of Open Access Journals (Sweden)

    Neys Lori

    2008-07-01

    Full Text Available Abstract Background Human B cells and plasmacytoid dendritic cells (pDC are the only cells known to express both TLR7 and TLR9. Plasmacytoid dendritic cells are the primary IFN-α producing cells in response to TLR7 and TLR9 agonists. The direct effects of TLR7 stimulation on human B cells is less understood. The objective of this study was to compare the effects of TLR7 and TLR9 stimulation on human B cell function. Results Gene expression and protein production of cytokines, chemokines, various B cell activation markers, and immunoglobulins were evaluated. Purified human CD19+ B cells (99.9%, containing both naïve and memory populations from peripheral blood were stimulated with a TLR7-selective agonist (852A, TLR7/8 agonist (3M-003, or TLR9 selective agonist CpG ODN (CpG2006. TLR7 and TLR9 agonists similarly modulated the expression of cytokine and chemokine genes (IL-6, MIP1 alpha, MIP1 beta, TNF alpha and LTA, co-stimulatory molecules (CD80, CD40 and CD58, Fc receptors (CD23, CD32, anti-apoptotic genes (BCL2L1, certain transcription factors (MYC, TCFL5, and genes critical for B cell proliferation and differentiation (CD72, IL21R. Both agonists also induced protein expression of the above cytokines and chemokines. Additionally, TLR7 and TLR9 agonists induced the production of IgM and IgG. A TLR8-selective agonist was comparatively ineffective at stimulating purified human B cells. Conclusion These results demonstrate that despite their molecular differences, the TLR7 and TLR9 agonists induce similar genes and proteins in purified human B cells.

  17. The B-cell identity factor Pax5 regulates distinct transcriptional programmes in early and late B lymphopoiesis

    Science.gov (United States)

    Revilla-i-Domingo, Roger; Bilic, Ivan; Vilagos, Bojan; Tagoh, Hiromi; Ebert, Anja; Tamir, Ido M; Smeenk, Leonie; Trupke, Johanna; Sommer, Andreas; Jaritz, Markus; Busslinger, Meinrad

    2012-01-01

    Pax5 controls the identity and development of B cells by repressing lineage-inappropriate genes and activating B-cell-specific genes. Here, we used genome-wide approaches to identify Pax5 target genes in pro-B and mature B cells. In these cell types, Pax5 bound to 40% of the cis-regulatory elements defined by mapping DNase I hypersensitive (DHS) sites, transcription start sites and histone modifications. Although Pax5 bound to 8000 target genes, it regulated only 4% of them in pro-B and mature B cells by inducing enhancers at activated genes and eliminating DHS sites at repressed genes. Pax5-regulated genes in pro-B cells account for 23% of all expression changes occurring between common lymphoid progenitors and committed pro-B cells, which identifies Pax5 as an important regulator of this developmental transition. Regulated Pax5 target genes minimally overlap in pro-B and mature B cells, which reflects massive expression changes between these cell types. Hence, Pax5 controls B-cell identity and function by regulating distinct target genes in early and late B lymphopoiesis. PMID:22669466

  18. Primary Hepatosplenic Large B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    M.R. Morales-Polanco

    2008-03-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  20. B cells contribute to MS pathogenesis through antibody-dependent and antibody-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Wilson HL

    2012-05-01

    Full Text Available Heather L Wilson1,21Vaccine and Infectious Disease Organization-International Vaccine Center, 2Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaAbstract: For many years, central dogma defined multiple sclerosis (MS as a T cell-driven autoimmune disorder; however, over the past decade there has been a burgeoning recognition that B cells contribute to the pathogenesis of certain MS disease subtypes. B cells may contribute to MS pathogenesis through production of autoantibodies (or antibodies directed at foreign bodies, which unfortunately cross-react with self-antigens, through promotion of T cell activation via antigen presentation, or through production of cytokines. This review highlights evidence for antibody-dependent and antibody-independent B cell involvement in MS pathogenesis.Keywords: autoantibodies, antibody targets, clinically isolated MS, primary progressive MS, secondary progressive MS, relapsing and remitting MS, T cells, T regulatory cells

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

    Science.gov (United States)

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

    2012-12-15

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

  2. B-Cell Response during Protozoan Parasite Infections

    OpenAIRE

    Amezcua Vesely, María C; Bermejo, Daniela A.; Montes, Carolina L.; Acosta-Rodríguez, Eva V.; Adriana Gruppi

    2012-01-01

    In this review, we discuss how protozoan parasites alter immature and mature B cell compartment. B1 and marginal zone (MZ) B cells, considered innate like B cells, are activated during protozoan parasite infections, and they generate short lived plasma cells providing a prompt antibody source. In addition, protozoan infections induce massive B cell response with polyclonal activation that leads to hypergammaglobulnemia with serum antibodies specific for the parasites and self and/or non relat...

  3. Resource Competition Determines Selection of B Cell Repertoires

    OpenAIRE

    de Boer, R J; Freitas, A. A.; Perelson, A. S.

    2001-01-01

    Previous experiments with mouse chimeras demonstrated that cellular competition for antigen- specific survival signals plays a crucial role in the maintenance of the naive B cell repertoire. Transgenic (Tg) B cell populations in these chimeras have a shortened lifespan and poor competitive abilities as compared to more diverse non-Tg populations in the same mice. We develop a mathematical model to investigate the mechanism of B cell competition. The model allows for various B cell clones, gen...

  4. Structural analysis of B-cell epitopes in antibody:protein complexes

    DEFF Research Database (Denmark)

    Kringelum, Jens Vindahl; Nielsen, Morten; Padkjær, Søren Berg; Lund, Ole

    developed a novel framework for comparing and superimposing B-cell epitopes and applied it on a dataset of 107 non-similar antigen:antibody structures extracted from the PDB database. With the presented framework, we were able to describe the general B-cell epitope as a flat, oblong, oval shaped volume......The binding of antigens to antibodies is one of the key events in an immune response against foreign molecules and is a critical element of several biomedical applications including vaccines and immunotherapeutics. For development of such applications, the identification of antibody binding sites...... (B-cell epitopes) is essential. However experimental epitope mapping is highly cost-intensive and computer-aided methods do in general have moderate performance. One major reason for this moderate performance is an incomplete understanding of what characterizes an epitope. To fill this gap, we here...

  5. Phenytoin Induced Cutaneous B Cell Pseudolymphoma.

    Science.gov (United States)

    Riyaz, Najeeba; Sasidharanpillai, Sarita; Aravindan, Karumathil P; Nobin, Babu K; Raghavan, Nisha T; Nikhila, Pappinissery K

    2015-01-01

    Cutaneous pseudolymphomas are benign lymphoproliferative processes mimicking lymphomas clinically and histologically. One of the precipitating factors for pseudolymphoma is drugs like anticonvulsants, antidepressants and angiotensin-converting enzyme inhibitors. According to existing literature phenytoin-induced cutaneous pseudolymphomas are usually T-cell predominant. Most often withdrawal of the drug with or without short-course systemic steroids can attain a cure. Rarely malignant transformation has been reported years later despite withdrawal of the offending drug, which necessitates a long-term follow up of the affected. We report an 80-year-old male patient who was receiving phenytoin sodium and who presented with diffuse erythema and infiltrated skin lesions which histologically resembled cutaneous B-cell lymphoma. Substituting phenytoin with levetiracetam achieved resolution of symptoms. Further evaluation was suggestive of a reactive process. A detailed drug history is of paramount importance in differentiating drug-induced pseudolymphoma from lymphoma. Searching literature we could not find any previous reports of phenytoin-induced cutaneous B-cell pseudolymphoma. PMID:26538730

  6. High-throughput combinatorial screening identifies drugs that cooperate with ibrutinib to kill activated B-cell-like diffuse large B-cell lymphoma cells.

    Science.gov (United States)

    Mathews Griner, Lesley A; Guha, Rajarshi; Shinn, Paul; Young, Ryan M; Keller, Jonathan M; Liu, Dongbo; Goldlust, Ian S; Yasgar, Adam; McKnight, Crystal; Boxer, Matthew B; Duveau, Damien Y; Jiang, Jian-Kang; Michael, Sam; Mierzwa, Tim; Huang, Wenwei; Walsh, Martin J; Mott, Bryan T; Patel, Paresma; Leister, William; Maloney, David J; Leclair, Christopher A; Rai, Ganesha; Jadhav, Ajit; Peyser, Brian D; Austin, Christopher P; Martin, Scott E; Simeonov, Anton; Ferrer, Marc; Staudt, Louis M; Thomas, Craig J

    2014-02-11

    The clinical development of drug combinations is typically achieved through trial-and-error or via insight gained through a detailed molecular understanding of dysregulated signaling pathways in a specific cancer type. Unbiased small-molecule combination (matrix) screening represents a high-throughput means to explore hundreds and even thousands of drug-drug pairs for potential investigation and translation. Here, we describe a high-throughput screening platform capable of testing compounds in pairwise matrix blocks for the rapid and systematic identification of synergistic, additive, and antagonistic drug combinations. We use this platform to define potential therapeutic combinations for the activated B-cell-like subtype (ABC) of diffuse large B-cell lymphoma (DLBCL). We identify drugs with synergy, additivity, and antagonism with the Bruton's tyrosine kinase inhibitor ibrutinib, which targets the chronic active B-cell receptor signaling that characterizes ABC DLBCL. Ibrutinib interacted favorably with a wide range of compounds, including inhibitors of the PI3K-AKT-mammalian target of rapamycin signaling cascade, other B-cell receptor pathway inhibitors, Bcl-2 family inhibitors, and several components of chemotherapy that is the standard of care for DLBCL. PMID:24469833

  7. Targeting neoplastic B cells and harnessing microenvironment: the "double face" of ibrutinib and idelalisib.

    Science.gov (United States)

    Maffei, Rossana; Fiorcari, Stefania; Martinelli, Silvia; Potenza, Leonardo; Luppi, Mario; Marasca, Roberto

    2015-01-01

    Tyrosine kinase inhibitors (TKIs) targeting signaling molecules downstream B cell receptor (BCR) are powerfully spreading in the therapeutic landscape of B cell lymphoproliferative disease, due to a manageable toxicity profile and encouraging clinical effectiveness. In particular, ibrutinib, previously called PCI-32765, is a potent inhibitor of Bruton tyrosine kinase (Btk), recently approved for the treatment of relapsed mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL). Moreover, idelalisib (formerly GS-1101 and CAL-101) is a selective reversible inhibitor of the p110δ isoform of phosphoinositol 3 kinase (PI3K) approved for the treatment of patients with relapsed follicular lymphoma (FL) and CLL. These agents directly affect the neoplastic clone, disrupting the supportive platform provided by BCR signaling cascade and by other microenvironmental mutualistic interactions, and also interfering with chemokine gradients and adhesive properties of neoplastic B cells. In the present review, we describe the clinical efficacy of ibrutinib and idelalisib in CLL and B cell non-Hodgkin lymphoma (B-NHL), then focusing on the mode of action (MOA) of these TKIs towards the neoplastic B cell compartment. At last, the review would further expand the view on potential additional targets of ibrutinib and idelalisib belonging to other microenvironmental cellular elements. PMID:26022368

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

    Science.gov (United States)

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

    2015-04-01

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

  9. Artery Tertiary Lymphoid Organs Control Multilayered Territorialized Atherosclerosis B-Cell Responses in Aged ApoE−/− Mice

    Science.gov (United States)

    Srikakulapu, Prasad; Hu, Desheng; Yin, Changjun; Mohanta, Sarajo K.; Bontha, Sai Vineela; Peng, Li; Beer, Michael; Weber, Christian; McNamara, Coleen A.; Grassia, Gianluca; Maffia, Pasquale; Manz, Rudolf A.

    2016-01-01

    Objective— Explore aorta B-cell immunity in aged apolipoprotein E-deficient (ApoE−/−) mice. Approach and Results— Transcript maps, fluorescence-activated cell sorting, immunofluorescence analyses, cell transfers, and Ig-ELISPOT (enzyme-linked immunospot) assays showed multilayered atherosclerosis B-cell responses in artery tertiary lymphoid organs (ATLOs). Aging-associated aorta B-cell–related transcriptomes were identified, and transcript atlases revealed highly territorialized B-cell responses in ATLOs versus atherosclerotic lesions: ATLOs showed upregulation of bona fide B-cell genes, including Cd19, Ms4a1 (Cd20), Cd79a/b, and Ighm although intima plaques preferentially expressed molecules involved in non–B effector responses toward B-cell–derived mediators, that is, Fcgr3 (Cd16), Fcer1g (Cd23), and the C1q family. ATLOs promoted B-cell recruitment. ATLO B-2 B cells included naive, transitional, follicular, germinal center, switched IgG1+, IgA+, and IgE+ memory cells, plasmablasts, and long-lived plasma cells. ATLOs recruited large numbers of B-1 cells whose subtypes were skewed toward interleukin-10+ B-1b cells versus interleukin-10− B-1a cells. ATLO B-1 cells and plasma cells constitutively produced IgM and IgG and a fraction of plasma cells expressed interleukin-10. Moreover, ApoE−/− mice showed increased germinal center B cells in renal lymph nodes, IgM-producing plasma cells in the bone marrow, and higher IgM and anti–MDA-LDL (malondialdehyde-modified low-density lipoprotein) IgG serum titers. Conclusions— ATLOs orchestrate dichotomic, territorialized, and multilayered B-cell responses in the diseased aorta; germinal center reactions indicate generation of autoimmune B cells within the diseased arterial wall during aging. PMID:27102965

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

    Science.gov (United States)

    Jain, Shweta; Chodisetti, Sathi Babu; Agrewala, Javed N

    2011-01-01

    Conventionally, signaling through BCR initiates sequence of events necessary for activation and differentiation of B cells. We report an alternative approach, independent of BCR, for stimulating resting B (RB) cells, by involving TLR-2 and CD40--molecules crucial for innate and adaptive immunity. CD40 triggering of TLR-2 stimulated RB cells significantly augments their activation, proliferation and differentiation. It also substantially ameliorates the calcium flux, antigen uptake capacity and ability of B cells to activate T cells. The survival of RB cells was improved and it increases the number of cells expressing activation induced deaminase (AID), signifying class switch recombination (CSR). Further, we also observed increased activation rate and decreased threshold period required for optimum stimulation of RB cells. These results corroborate well with microarray gene expression data. This study provides novel insights into coordination between the molecules of innate and adaptive immunity in activating B cells, in a BCR independent manner. This strategy can be exploited to design vaccines to bolster B cell activation and antigen presenting efficiency, leading to faster and better immune response. PMID:21674065

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

    Directory of Open Access Journals (Sweden)

    Shweta Jain

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

  12. Selective loss of B-cell phenotype in lymphocyte predominant Hodgkin lymphoma.

    Science.gov (United States)

    Tedoldi, S; Mottok, A; Ying, J; Paterson, J C; Cui, Y; Facchetti, F; van Krieken, J H J M; Ponzoni, M; Ozkal, S; Masir, N; Natkunam, Y; Pileri, Sa; Hansmann, M-L; Mason, Dy; Tao, Q; Marafioti, T

    2007-12-01

    The neoplastic Reed-Sternberg cells characteristic of classical Hodgkin's lymphoma (cHL) are of B-cell origin but they almost always show striking loss of a range of B-cell-associated molecules. In contrast, the neoplastic cells found in lymphocyte predominant Hodgkin's lymphoma (LPHL) (L&H cells) are traditionally thought of as possessing the full repertoire of features associated with germinal centre B cells (eg BCL-6 expression, 'ongoing' Ig gene mutation). In the present paper, we report an extensive phenotypic analysis of L&H cells which revealed down-regulation of a number of markers associated with the B-cell lineage (eg CD19, CD37) and with the germinal centre maturation stage (eg PAG, LCK). The promoter methylation status of three of these down-regulated genes (CD10, CD19, and LCK) was further studied in microdissected L&H cells, and this revealed that their promoters were unmethylated. In contrast, these genes showed promoter methylation in cell lines derived from CHL. Further investigation of the mechanisms responsible for the deregulation of these molecules in L&H cells may provide new insights into the genetic abnormalities underlying LPHL. PMID:17935142

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

    Science.gov (United States)

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

    2016-04-01

    The requirement for the B-cell transcription factor OCT2 (octamer-binding protein 2, encoded by Pou2f2) in germinal center B cells has proved controversial. Here, we report that germinal center B cells are formed normally after depletion of OCT2 in a conditional knockout mouse, but their proliferation is reduced and in vivo differentiation to antibody-secreting plasma cells is blocked. This finding led us to examine the role of OCT2 in germinal center-derived lymphomas. shRNA knockdown showed that almost all diffuse large B-cell lymphoma (DLBCL) cell lines are addicted to the expression of OCT2 and its coactivator OCA-B. Genome-wide chromatin immunoprecipitation (ChIP) analysis and gene-expression profiling revealed the broad transcriptional program regulated by OCT2 that includes the expression of STAT3, IL-10, ELL2, XBP1, MYC, TERT, and ADA. Importantly, genetic alteration of OCT2 is not a requirement for cellular addiction in DLBCL. However, we detected amplifications of the POU2F2 locus in DLBCL tumor biopsies and a recurrent mutation of threonine 223 in the DNA-binding domain of OCT2. This neomorphic mutation subtly alters the DNA-binding preference of OCT2, leading to the transactivation of noncanonical target genes including HIF1a and FCRL3 Finally, by introducing mutations designed to disrupt the OCT2-OCA-B interface, we reveal a requirement for this protein-protein interface that ultimately might be exploited therapeutically. Our findings, combined with the predominantly B-cell-restricted expression of OCT2 and the absence of a systemic phenotype in our knockout mice, suggest that an OCT2-targeted therapeutic strategy would be efficacious in both major subtypes of DLBCL while avoiding systemic toxicity. PMID:26993806

  14. Interleukin 2 receptors on human B cells. Implications for the role of interleukin 2 in human B cell function

    OpenAIRE

    1985-01-01

    In the present study, we examined the expression of interleukin 2 (IL- 2) receptors on normal human B cells as well as established B cell lines. Anti-Tac monoclonal antibody did not bind to freshly separated normal human B cells. Unexpectedly, with the appropriate activation of the normal B cells by anti-mu antibody, phorbol myristate acetate, or Staphylococcus aureus Cowan I (SAC), Tac antigen was induced on the activated B cells. Anti-Tac antibody showed consistent reactivity with two B cel...

  15. Genomic regions associated with multiple sclerosis are active in B cells.

    Directory of Open Access Journals (Sweden)

    Giulio Disanto

    Full Text Available More than 50 genomic regions have now been shown to influence the risk of multiple sclerosis (MS. However, the mechanisms of action, and the cell types in which these associated variants act at the molecular level remain largely unknown. This is especially true for associated regions containing no known genes. Given the evidence for a role for B cells in MS, we hypothesized that MS associated genomic regions co-localized with regions which are functionally active in B cells. We used publicly available data on 1 MS associated regions and single nucleotide polymorphisms (SNPs and 2 chromatin profiling in B cells as well as three additional cell types thought to be unrelated to MS (hepatocytes, fibroblasts and keratinocytes. Genomic intervals and SNPs were tested for overlap using the Genomic Hyperbrowser. We found that MS associated regions are significantly enriched in strong enhancer, active promoter and strong transcribed regions (p = 0.00005 and that this overlap is significantly higher in B cells than control cells. In addition, MS associated SNPs also land in active promoter (p = 0.00005 and enhancer regions more than expected by chance (strong enhancer p = 0.0006; weak enhancer p = 0.00005. These results confirm the important role of the immune system and specifically B cells in MS and suggest that MS risk variants exert a gene regulatory role. Previous studies assessing MS risk variants in T cells may be missing important effects in B cells. Similar analyses in other immunological cell types relevant to MS and functional studies are necessary to fully elucidate how genes contribute to MS pathogenesis.

  16. Dynamic changes of B-cell compartments in kidney transplantation: lack of transitional B cells is associated with allograft rejection.

    Science.gov (United States)

    Svachova, Veronika; Sekerkova, Alena; Hruba, Petra; Tycova, Irena; Rodova, Marketa; Cecrdlova, Eva; Slatinska, Janka; Honsova, Eva; Striz, Ilja; Viklicky, Ondrej

    2016-05-01

    B cells play an important role in the immune responses which affect the outcomes of kidney allografts. Dynamic changes of B-cell compartments in clinical kidney transplantation are still poorly understood. B-cell subsets were prospectively monitored using flow cytometry for 1 year in 98 kidney transplant recipients. Data were correlated with immunosuppression and clinical outcomes. An increase in the total population of B lymphocytes was observed during the first week after transplantation. The level of IgM(high) CD38(high) CD24(high) transitional B cells reduced significantly up until the third month, with partial repopulation in the first year. Lower numbers of transitional B cells in the third month were associated with higher risk of graft rejection. IgM(+) IgD(+) CD27(-) naive B cells did not change within follow-up. IgM(+) CD27(+) nonswitched memory B cells and IgM(-) CD27(+) switched memory B cells increased on post-operative day 7. IgM(-) CD38(high) CD27(high) plasmablasts showed similar kinetics during the first post-transplant year, similar to transitional B cells. In conclusion, sensitized kidney transplant recipients as well as those with either acute or chronic rejection within the first post-transplant year exhibited lower levels of transitional B cells. Therefore, these data further support the hypothesis that transitional B cells have a protective role in kidney transplantation. PMID:26839984

  17. Enhanced Expression of Bruton's Tyrosine Kinase in B Cells Drives Systemic Autoimmunity by Disrupting T Cell Homeostasis.

    Science.gov (United States)

    Corneth, Odilia B J; de Bruijn, Marjolein J W; Rip, Jasper; Asmawidjaja, Patrick S; Kil, Laurens P; Hendriks, Rudi W

    2016-07-01

    Upon BCR stimulation, naive B cells increase protein levels of the key downstream signaling molecule Bruton's tyrosine kinase (BTK). Transgenic CD19-hBtk mice with B cell-specific BTK overexpression show spontaneous germinal center formation, anti-nuclear autoantibodies, and systemic autoimmunity resembling lupus and Sjögren syndrome. However, it remains unknown how T cells are engaged in this pathology. In this study, we found that CD19-hBtk B cells were high in IL-6 and IL-10 and disrupted T cell homeostasis in vivo. CD19-hBtk B cells promoted IFN-γ production by T cells and expression of the immune-checkpoint protein ICOS on T cells and induced follicular Th cell differentiation. Crosses with CD40L-deficient mice revealed that increased IL-6 production and autoimmune pathology in CD19-hBtk mice was dependent on B-T cell interaction, whereas IL-10 production and IgM autoantibody formation were CD40L independent. Surprisingly, in Btk-overexpressing mice, naive B cells manifested increased CD86 expression, which was dependent on CD40L, suggesting that T cells interact with B cells in a very early stage of immune pathology. These findings indicate that increased BTK-mediated signaling in B cells involves a positive-feedback loop that establishes T cell-propagated autoimmune pathology, making BTK an attractive therapeutic target in autoimmune disease. PMID:27226091

  18. 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;

    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......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...

  19. CD27/CD70 interaction augments IgE secretion by promoting the differentiation of memory B cells into plasma cells.

    Science.gov (United States)

    Nagumo, H; Agematsu, K; Shinozaki, K; Hokibara, S; Ito, S; Takamoto, M; Nikaido, T; Yasui, K; Uehara, Y; Yachie, A; Komiyama, A

    1998-12-15

    The induction of IgE switching in B cells requires several signals given by cytokines and cell contact-delivered signals. Here, we investigated the role of CD27/CD70 interaction in B cell IgE synthesis. The addition of CD27 ligand (CD70) transfectants to B cell cultures increased the IgE synthesis synergistically in the presence of IL-4 plus anti-CD40 mAb (anti-CD40). The effect of CD70 transfectants was dose dependent and was completely blocked by anti-CD70 mAb. CD27+ B cells had the ability to produce IgE, which was increased by contact with CD70 transfectants, whereas CD27- B cells did not produce IgE. CD27/CD70 interaction enhanced B cell proliferation in the presence of IL-4 or IL-4 plus anti-CD40. The augmentation of B cell proliferation by CD70 transfectants was apparent in CD27+ B cells, but was mild in CD27- B cells. The helper activity for IgE synthesis by the CD27/CD70 interaction did not contribute to the enhancement of germline epsilon transcripts. Flow cytometric and morphological analyses demonstrated that the addition of CD70 transfectants to B cell cultures remarkably promoted differentiation into plasma cells in the presence of IL-4 and CD40 signaling. Finally, CD27 cross-linking resulted in the up-regulation of positive regulatory domain I-binding factor-1. Taken together, our findings indicate that signaling via CD27 on B cells induces IgE synthesis, in cooperation with IL-4 and CD40 signaling, by promoting the generation of plasma cells through up-regulation of positive regulatory domain I-binding factor-1. PMID:9862673

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

    Science.gov (United States)

    Dao, Phuong; Wojtowicz, Damian; Nelson, Steevenson; Levens, David; Przytycka, Teresa M

    2016-04-01

    Recent genome-wide analyses have uncovered a high accumulation of RNA polymerase II (Pol II) at the 5' end of genes. This elevated Pol II presence at promoters, referred to here as Poll II poising, is mainly (but not exclusively) attributed to temporal pausing of transcription during early elongation which, in turn, has been proposed to be a regulatory step for processes that need to be activated "on demand". Yet, the full genome-wide regulatory role of Pol II poising is yet to be delineated. To elucidate the role of Pol II poising in B cell activation, we compared Pol II profiles in resting and activated B cells. We found that while Pol II poised genes generally overlap functionally among different B cell states and correspond to the functional groups previously identified for other cell types, non-poised genes are B cell state specific. Focusing on the changes in transcription activity upon B cell activation, we found that the majority of such changes were from poised to non-poised state. The genes showing this type of transition were functionally enriched in translation, RNA processing and mRNA metabolic process. Interestingly, we also observed a transition from non-poised to poised state. Within this set of genes we identified several Immediate Early Genes (IEG), which were highly expressed in resting B cell and shifted from non-poised to poised state after B cell activation. Thus Pol II poising does not only mark genes for rapid expression in the future, but it is also associated with genes that are silenced after a burst of their expression. Finally, we performed comparative analysis of the presence of G4 motifs in the context of poised versus non-poised but active genes. Interestingly we observed a differential enrichment of these motifs upstream versus downstream of TSS depending on poising status. The enrichment of G4 sequence motifs upstream of TSS of non-poised active genes suggests a potential role of quadruplexes in expression regulation. PMID:27078128

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

    Directory of Open Access Journals (Sweden)

    Phuong Dao

    2016-04-01

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

  2. Identification of a sub-population of B cells that proliferates after infection with epstein-barr virus

    Directory of Open Access Journals (Sweden)

    Ye Jianjiang

    2011-02-01

    Full Text Available Abstract Background Epstein-Barr virus (EBV-driven B cell proliferation is critical to its subsequent persistence in the host and is a key event in the development of EBV-associated B cell diseases. Thus, inquiry into early cellular events that precede EBV-driven proliferation of B cells is essential for understanding the processes that can lead to EBV-associated B cell diseases. Methods Infection with high titers of EBV of mixed, primary B cells in different stages of differentiation occurs during primary EBV infection and in the setting of T cell-immunocompromise that predisposes to development of EBV-lymphoproliferative diseases. Using an ex vivo system that recapitulates these conditions of infection, we correlated expression of selected B cell-surface markers and intracellular cytokines with expression of EBV latency genes and cell proliferation. Results We identified CD23, CD58, and IL6, as molecules expressed at early times after EBV-infection. EBV differentially infected B cells into two distinct sub-populations of latently infected CD23+ cells: one fraction, marked as CD23hiCD58+IL6- by day 3, subsequently proliferated; another fraction, marked as CD23loCD58+, expressed IL6, a B cell growth factor, but failed to proliferate. High levels of LMP1, a critical viral oncoprotein, were expressed in individual CD23hiCD58+ and CD23loCD58+ cells, demonstrating that reduced levels of LMP1 did not explain the lack of proliferation of CD23loCD58+ cells. Differentiation stage of B cells did not appear to govern this dichotomy in outcome either. Memory or naïve B cells did not exclusively give rise to either CD23hi or IL6-expressing cells; rather memory B cells gave rise to both sub-populations of cells. Conclusions B cells are differentially susceptible to EBV-mediated proliferation despite expression of viral gene products known to be critical for continuous B cell growth. Cellular events, in addition to viral gene expression, likely play a

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

    Directory of Open Access Journals (Sweden)

    Vijaya Gadage

    2011-01-01

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

  4. Differential programming of B cells in AID deficient mice.

    Directory of Open Access Journals (Sweden)

    Marc A Hogenbirk

    Full Text Available The Aicda locus encodes the activation induced cytidine deaminase (AID and is highly expressed in germinal center (GC B cells to initiate somatic hypermutation (SHM and class switch recombination (CSR of immunoglobulin (Ig genes. Besides these Ig specific activities in B cells, AID has been implicated in active DNA demethylation in non-B cell systems. We here determined a potential role of AID as an epigenetic eraser and transcriptional regulator in B cells. RNA-Seq on different B cell subsets revealed that Aicda(-/- B cells are developmentally affected. However as shown by RNA-Seq, MethylCap-Seq, and SNP analysis these transcriptome alterations may not relate to AID, but alternatively to a CBA mouse strain derived region around the targeted Aicda locus. These unexpected confounding parameters provide alternative, AID-independent interpretations on genotype-phenotype correlations previously reported in numerous studies on AID using the Aicda(-/- mouse strain.

  5. Innate response activator B cells: origins and functions.

    Science.gov (United States)

    Chousterman, Benjamin G; Swirski, Filip K

    2015-10-01

    Innate response activator (IRA) B cells are a subset of B-1a derived B cells that produce the growth factors granulocyte macrophage colony stimulating factor and IL-3. In mouse models of sepsis and pneumonia, B-1a B cells residing in serosal sites recognize bacteria, migrate to the spleen or lung, and differentiate to IRA B cells that then contribute to the host response by amplifying inflammation and producing polyreactive IgM. In atherosclerosis, IRA B cells accumulate in the spleen, where they promote extramedullary hematopoiesis and activate classical dendritic cells. In this review, we focus on the ontogeny and function of IRA B cells in acute and chronic inflammation. PMID:25957266

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

    DEFF Research Database (Denmark)

    Faurschou, Mikkel; Jayne, David R W

    2014-01-01

    Several monoclonal antibodies targeting B cells have been tested as therapeutics for inflammatory rheumatic diseases. We review important observations from randomized clinical trials regarding the efficacy and safety of anti-B cell antibody-based therapies for rheumatoid arthritis, systemic lupus...... erythematosus, antineutrophil cytoplasmic antibody-associated vasculitis, polymyositis/dermatomyositis, and primary Sjögren's syndrome. For some anti-B cell agents, clinical benefits have been convincingly demonstrated, while other B cell-targeted therapies failed to improve outcomes when added to standard......-of-care treatment or were associated with increased rates of adverse events. Although the risk-benefit balance seems to be acceptable for currently licensed anti-B cell agents, additional studies are required to fully assess the safety of treatment regimens involving prolonged interference with B cell counts and...

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

    OpenAIRE

    2012-01-01

    The gut is the most common extranodal site where lymphomas arise. Although all histological lymphoma types may develop in the gut, small and large B-cell lymphomas predominate. The sometimes unexpected finding of a lymphoid lesion in an endoscopic biopsy of the gut may challenge both the clinician (who is not always familiar with lymphoma pathogenesis) and the pathologist (who will often be hampered in his/her diagnostic skill by the limited amount of available tissue). Moreover, the past 2 d...

  8. Overexpression of Fc receptor-like 1 associated with B-cell activation during hepatitis B virus infection

    International Nuclear Information System (INIS)

    The role of B cells in the pathogenesis of hepatitis B virus (HBV) infection has not been explored in depth. In the present study, the activation status of B cells from peripheral blood of healthy controls (N = 20) and patients with acute hepatitis B (AHB, N = 15) or chronic hepatitis B (CHB, N = 30) was evaluated by measuring the expression levels of B-cell activation markers CD69 and CD86, using quantitative real-time PCR and flow cytometry. Moreover, the potential mechanism underlying B-cell activation during HBV infection was further investigated by analyzing the expression profile of FCRL1, an intrinsic activation molecule of B cells. An elevation in the levels of B-cell activation markers including CD69 and CD86 was observed in the AHB patients (44.31 ± 9.27, 27.64 ± 9.26%) compared to CHB patients (30.35 ± 11.27, 18.41 ± 6.56%, P < 0.05), which was still higher than healthy controls (12.23 ± 7.84, 8.22 ± 3.43%, P < 0.05). Furthermore, the expression of FCRL1 was found to be similar to B-cell activation markers, which was highest in AHB patients (70.15 ± 17.11%), lowest in healthy donors (36.32 ± 9.98%, P < 0.05) and half-way between these levels in patients with CHB (55.17 ± 12.03%, P < 0.05). The results were positively associated with aberrant B-cell activation. These data suggest that B cells can play a role in HBV infection, and therefore more effort should be devoted to exploring their functions

  9. Self DNA from lymphocytes that have undergone activation-induced cell death enhances murine B cell proliferation and antibody production.

    Directory of Open Access Journals (Sweden)

    Qing Lu

    Full Text Available Systemic lupus erythematosus (SLE is characterized by prominent autoinflammatory tissue damage associated with impaired removal of dying cells and DNA. Self DNA-containing immune complexes are able to activate both innate and adaptive immune responses and play an important role in the maintenance and exacerbation of autoimmunity in SLE. In this study, we used DNA from lymphocytes that have undergone activation-induced cell death (ALD-DNA and analyzed its role on the activation and differentiation of B cells from normal BALB/c mice as well as lupus-prone MRL+/+ and MRL/lpr mice. We found that ALD-DNA directly increased the expression of costimulatory molecules and the survival of naïve B cells in vitro. Although ALD-DNA alone had little effect on the proliferation of naïve B cells, it enhanced LPS-activated B cell proliferation in vitro and in vivo. In addition, ALD-DNA increased plasma cell numbers and IgG production in LPS-stimulated cultures of naïve B cells, in part via enhancing IL-6 production. Importantly, B cells from lupus mice were hyperresponsive to ALD-DNA and/or LPS relative to normal control B cells in terminal plasma cell differentiation, as evidenced by increases in CD138+ cell numbers, IgM production, and mRNA levels of B lymphocyte-induced maturation protein-1 (Blimp-1 and the X-box binding protein 1 (XBP1. Furthermore, ALD-DNA enhanced CD40-activated naïve B cell proliferation. Collectively, these data indicate that self DNA can serve as a DAMP (damage-associated molecular pattern that cooperates with signals from both innate and adaptive immunity to promote polyclonal B cell activation, a common characteristic of autoimmune diseases.

  10. Overexpression of Fc receptor-like 1 associated with B-cell activation during hepatitis B virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ke [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu Province (China); Pei, Hao [Wuxi Hospital of Infectious Disease, Wuxi, Jiangsu Province (China); Huang, Biao; Yang, Run-Lin [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu Province (China); Wu, Hang-Yuan [Wuxi Hospital of Infectious Disease, Wuxi, Jiangsu Province (China); Zhu, Xue; Zhu, Lan [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu Province (China)

    2012-08-17

    The role of B cells in the pathogenesis of hepatitis B virus (HBV) infection has not been explored in depth. In the present study, the activation status of B cells from peripheral blood of healthy controls (N = 20) and patients with acute hepatitis B (AHB, N = 15) or chronic hepatitis B (CHB, N = 30) was evaluated by measuring the expression levels of B-cell activation markers CD69 and CD86, using quantitative real-time PCR and flow cytometry. Moreover, the potential mechanism underlying B-cell activation during HBV infection was further investigated by analyzing the expression profile of FCRL1, an intrinsic activation molecule of B cells. An elevation in the levels of B-cell activation markers including CD69 and CD86 was observed in the AHB patients (44.31 ± 9.27, 27.64 ± 9.26%) compared to CHB patients (30.35 ± 11.27, 18.41 ± 6.56%, P < 0.05), which was still higher than healthy controls (12.23 ± 7.84, 8.22 ± 3.43%, P < 0.05). Furthermore, the expression of FCRL1 was found to be similar to B-cell activation markers, which was highest in AHB patients (70.15 ± 17.11%), lowest in healthy donors (36.32 ± 9.98%, P < 0.05) and half-way between these levels in patients with CHB (55.17 ± 12.03%, P < 0.05). The results were positively associated with aberrant B-cell activation. These data suggest that B cells can play a role in HBV infection, and therefore more effort should be devoted to exploring their functions.

  11. Quantifying evolutionary constraints on B cell affinity maturation

    OpenAIRE

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

    2014-01-01

    The antibody repertoire of each individual is continuously updated by the evolutionary process of B cell receptor mutation and selection. It has recently become possible to gain detailed information concerning this process through high-throughput sequencing. Here, we develop modern statistical molecular evolution methods for the analysis of B cell sequence data, and then apply them to a very deep short-read data set of B cell receptors. We find that the substitution process is conserved acros...

  12. Monitoring B cell subsets and alloreactivity in kidney transplantation

    OpenAIRE

    Crespo Barrio, Marta; Heidtc, Sebastiaan; Redondo Pach??n, Mar??a Dolores; Pascual Santos, Julio

    2015-01-01

    B cells are the precursors of antibody producing plasma cells that can give rise to the formation of donor-specific antibodies. However, recent data suggest that besides their role in antibody production, B cells participate in antibody-independent responses, potentially leading to allograft rejection or allograft tolerance. The presence of CD20+ B cells in kidney graft biopsies has been shown during severe acute rejection episodes and during chronic rejection. Furthermore, operationally tole...

  13. B cells as a target of immune modulation

    Directory of Open Access Journals (Sweden)

    Hawker Kathleen

    2009-01-01

    Full Text Available B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts. MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell-targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target.

  14. Myelin Basic Protein-Induced Production of Tumor Necrosis Factor-α and Interleukin-6, and Presentation of the Immunodominant Peptide MBP85-99 by B Cells from Patients with Relapsing-Remitting Multiple Sclerosis.

    Science.gov (United States)

    Nielsen, Claus H; Börnsen, Lars; Sellebjerg, Finn; Brimnes, Marie K

    2016-01-01

    B cells are involved in driving relapsing-remitting multiple sclerosis (RRMS), as demonstrated by the positive effect of therapeutic B-cell depletion. Aside from producing antibodies, B cells are efficient antigen-presenting and cytokine-secreting cells. Diverse polyclonal stimuli have been used to study cytokine production by B cells, but here we used the physiologically relevant self-antigen myelin basic protein (MBP) to stimulate B cells from untreated patients with RRMS and healthy donors. Moreover, we took advantage of the unique ability of the monoclonal antibody MK16 to recognize the immunodominant peptide MBP85-99 presented on HLA-DR15, and used it as a probe to directly study B-cell presentation of self-antigenic peptide. The proportions of B cells producing TNF-α or IL-6 after stimulation with MBP were higher in RRMS patients than in healthy donors, indicating a pro-inflammatory profile for self-reactive patient B cells. In contrast, polyclonal stimulation with PMA + ionomycin and MBP revealed no difference in cytokine profile between B cells from RRMS patients and healthy donors. Expanded disability status scale (EDSS) as well as multiple sclerosis severity score (MSSS) correlated with reduced ability of B cells to produce IL-10 after stimulation with MBP, indicative of diminished B-cell immune regulatory function in patients with the most severe disease. Moreover, EDSS correlated positively with the frequencies of TNF-α, IL-6 and IL-10 producing B cells after polyclonal stimulation. Patient-derived, IL-10-producing B cells presented MBP85-99 poorly, as did IL-6-producing B cells, particulary in the healthy donor group. B cells from MS patients thus present antigen to T cells in a pro-inflammatory context. These findings contribute to understanding the therapeutic effects of B-cell depletion in human autoimmune diseases, including MS. PMID:26756931

  15. The B-cell receptor orchestrates environment-mediated lymphoma survival and drug resistance in B-cell malignancies

    OpenAIRE

    Shain, KH; Tao, J.

    2013-01-01

    Specific niches within the lymphoma tumor microenvironment (TME) provide sanctuary for subpopulations of tumor cells through stromal cell–tumor cell interactions. These interactions notably dictate growth, response to therapy and resistance of residual malignant B cells to therapeutic agents. This minimal residual disease (MRD) remains a major challenge in the treatment of B-cell malignancies and contributes to subsequent disease relapse. B-cell receptor (BCR) signaling has emerged as essenti...

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

    Directory of Open Access Journals (Sweden)

    E. L. Nazarova

    2014-01-01

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

  17. 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. PMID:22566852

  18. Tissue-specific B-cell dysfunction and generalized memory B-cell loss during acute SIV infection.

    Directory of Open Access Journals (Sweden)

    Sandrine Peruchon

    Full Text Available BACKGROUND: Primary HIV-infected patients display severe and irreversible damage to different blood B-cell subsets which is not restored by highly efficient anti-retroviral therapy (HAART. Because longitudinal investigations of primary HIV-infection is limited by the availability of lymphoid organs, we studied the tissue-specific B-cell dysfunctions in acutely simian immunodeficiency virus (SIV mac251-infected Cynomolgus macaques. METHODS AND FINDINGS: Experiments were performed on three groups of macaques infected for 14, 21 or 28 days and on three groups of animals treated with HAART for two-weeks either initiated at 4 h, 7 or 14 days post-infection (p.i.. We have simultaneously compared changes in B-cell phenotypes and functions and tissue organization of B-cell areas in various lymphoid organs. We showed that SIV induced a steady decline in SIgG-expressing memory (SIgD(-CD27(+ B-cells in spleen and lymph nodes during the first 4 weeks of infection, concomitant to selective homing/sequestration of B-cells to the small intestine and spleen. SIV non-specific Ig production was transiently increased before D14p.i., whereas SIV-specific Ig production was only detectable after D14p.i., coinciding with the presence of CD8(+ T-cells and IgG-expressing plasma cells within germinal centres. Transient B-cell apoptosis on D14p.i. and commitment to terminal differentiation contributed to memory B-cell loss. HAART abrogated B-cell apoptosis, homing to the small intestine and SIV-specific Ig production but had minimal effect on early Ig production, increased B-cell proportions in spleen and loss of memory B-cells. Therefore, virus-B-cell interactions and SIV-induced inflammatory cytokines may differently contribute to early B-cell dysfunction and impaired SIV/HIV-specific antibody response. CONCLUSIONS: These data establish tissue-specific impairments in B-cell trafficking and functions and a generalized and steady memory B-cell loss in secondary lymphoid

  19. Promoter methylation and expression levels of selected hematopoietic genes in pediatric B-cell acute lymphoblastic leukemia

    OpenAIRE

    Musialik, Ewa; Bujko, Mateusz; Kober, Paulina; Agnieszka WYPYCH; Gawle-Krawczyk, Karolina; Matysiak, Michal; Siedlecki, Janusz Aleksander

    2015-01-01

    Background Precursor B-cell acute lymphoblastic leukemia (B-cell ALL) is the most common neoplasm in children and is characterized by genetic and epigenetic aberrations in hematopoietic transcription factor (TF) genes. This study evaluated promoter DNA methylation and aberrant expression levels of early- and late-acting hematopoietic TF genes homeobox A4 and A5 (HOXA4 and HOXA5), Meis homeobox 1 (MEIS1), T-cell acute lymphocytic leukemia 1 (TAL1), and interferon regulatory factors 4 and 8 (IR...

  20. DNA breaks early in replication in B cell cancers

    Science.gov (United States)

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

  1. Therapeutic strategies targeting B-cells in multiple sclerosis.

    Science.gov (United States)

    Milo, Ron

    2016-07-01

    Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system (CNS) that traditionally has been considered to be mediated primarily by T-cells. Increasing evidence, however, suggests the fundamental role of B-cells in the pathogenesis of the disease. Recent strategies targeting B-cells in MS have demonstrated impressive and sometimes surprising results: B-cell depletion by monoclonal antibodies targeting the B-cell surface antigen CD20 (e.g. rituximab, ocrelizumab, ofatumumab) was shown to exert profound anti-inflammatory effect in MS with favorable risk-benefit ratio, with ocrelizumab demonstrating efficacy in both relapsing-remitting (RR) and primary-progressive (PP) MS in phase III clinical trials. Depletion of CD52 expressing T- and B-cells and monocytes by alemtuzumab resulted in impressive and durable suppression of disease activity in RRMS patients. On the other hand, strategies targeting B-cell cytokines such as atacicept resulted in increased disease activity. As our understanding of the biology of B-cells in MS is increasing, new compounds that target B-cells continue to be developed which promise to further expand the armamentarium of MS therapies and allow for more individualized therapy for patients with this complex disease. PMID:26970489

  2. Interaction between Mesenchymal Stem Cells and B-Cells

    Science.gov (United States)

    Fan, Linxiao; Hu, Chenxia; Chen, Jiajia; Cen, Panpan; Wang, Jie; Li, Lanjuan

    2016-01-01

    Mesenchymal stem cells (MSCs) are multipotent; non-hematopoietic stem cells. Because of their immunoregulatory abilities; MSCs are widely used for different clinical applications. Compared with that of other immune cells; the investigation of how MSCs specifically regulate B-cells has been superficial and insufficient. In addition; the few experimental studies on this regulation are often contradictory. In this review; we summarize the various interactions between different types or states of MSCs and B-cells; address how different types of MSCs and B-cells affect this interaction and examine how other immune cells influence the regulation of B-cells by MSCs. Finally; we hypothesize why there are conflicting results on the interaction between MSCs and B-cells in the literature. PMID:27164080

  3. CD83 Modulates B Cell Activation and Germinal Center Responses.

    Science.gov (United States)

    Krzyzak, Lena; Seitz, Christine; Urbat, Anne; Hutzler, Stefan; Ostalecki, Christian; Gläsner, Joachim; Hiergeist, Andreas; Gessner, André; Winkler, Thomas H; Steinkasserer, Alexander; Nitschke, Lars

    2016-05-01

    CD83 is a maturation marker for dendritic cells. In the B cell lineage, CD83 is expressed especially on activated B cells and on light zone B cells during the germinal center (GC) reaction. The function of CD83 during GC responses is unclear. CD83(-/-) mice have a strong reduction of CD4(+) T cells, which makes it difficult to analyze a functional role of CD83 on B cells during GC responses. Therefore, in the present study we generated a B cell-specific CD83 conditional knockout (CD83 B-cKO) model. CD83 B-cKO B cells show defective upregulation of MHC class II and CD86 expression and impaired proliferation after different stimuli. Analyses of GC responses after immunization with various Ags revealed a characteristic shift in dark zone and light zone B cell numbers, with an increase of B cells in the dark zone of CD83 B-cKO mice. This effect was not accompanied by alterations in the level of IgG immune responses or by major differences in affinity maturation. However, an enhanced IgE response was observed in CD83 B-cKO mice. Additionally, we observed a strong competitive disadvantage of CD83-cKO B cells in GC responses in mixed bone marrow chimeras. Furthermore, infection of mice with Borrelia burgdorferi revealed a defect in bacterial clearance of CD83 B-cKO mice with a shift toward a Th2 response, indicated by a strong increase in IgE titers. Taken together, our results show that CD83 is important for B cell activation and modulates GC composition and IgE Ab responses in vivo. PMID:26983787

  4. Differential and site specific impact of B cells in the protective immune response to Mycobacterium tuberculosis in the mouse.

    Directory of Open Access Journals (Sweden)

    Egídio Torrado

    Full Text Available Cell-mediated immune responses are known to be critical for control of mycobacterial infections whereas the role of B cells and humoral immunity is unclear. B cells can modulate immune responses by secretion of immunoglobulin, production of cytokines and antigen-presentation. To define the impact of B cells in the absence of secreted immunoglobulin, we analyzed the progression of Mycobacterium tuberculosis (Mtb infection in mice that have B cells but which lack secretory immunoglobulin (AID(-/-µS(-/-mice. AID(-/-µS(-/- mice accumulated a population of activated B cells in the lungs when infected and were more susceptible to aerosol Mtb when compared to wild type (C57BL/6 mice or indeed mice that totally lack B cells. The enhanced susceptibility of AID(-/-µS(-/- mice was not associated with defective T cell activation or expression of a type 1 immune response. While delivery of normal serum to AID(-/-µS(-/- mice did not reverse susceptibility, susceptibility in the spleen was dependent upon the presence of B cells and susceptibility in the lungs of AID(-/-µS(-/-mice was associated with elevated expression of the cytokines IL-6, GM-CSF, IL-10 and molecules made by alternatively activated macrophages. Blocking of IL-10 signaling resulted in reversal of susceptibility in the spleens and lungs of AID(-/-µS(-/- mice. These data support the hypothesis that B cells can modulate immunity to Mtb in an organ specific manner via the modulation of cytokine production and macrophage activation.

  5. Differential and site specific impact of B cells in the protective immune response to Mycobacterium tuberculosis in the mouse.

    Science.gov (United States)

    Torrado, Egídio; Fountain, Jeffrey J; Robinson, Richard T; Martino, Cynthia A; Pearl, John E; Rangel-Moreno, Javier; Tighe, Michael; Dunn, Robert; Cooper, Andrea M

    2013-01-01

    Cell-mediated immune responses are known to be critical for control of mycobacterial infections whereas the role of B cells and humoral immunity is unclear. B cells can modulate immune responses by secretion of immunoglobulin, production of cytokines and antigen-presentation. To define the impact of B cells in the absence of secreted immunoglobulin, we analyzed the progression of Mycobacterium tuberculosis (Mtb) infection in mice that have B cells but which lack secretory immunoglobulin (AID(-/-)µS(-/-)mice). AID(-/-)µS(-/-) mice accumulated a population of activated B cells in the lungs when infected and were more susceptible to aerosol Mtb when compared to wild type (C57BL/6) mice or indeed mice that totally lack B cells. The enhanced susceptibility of AID(-/-)µS(-/-) mice was not associated with defective T cell activation or expression of a type 1 immune response. While delivery of normal serum to AID(-/-)µS(-/-) mice did not reverse susceptibility, susceptibility in the spleen was dependent upon the presence of B cells and susceptibility in the lungs of AID(-/-)µS(-/-)mice was associated with elevated expression of the cytokines IL-6, GM-CSF, IL-10 and molecules made by alternatively activated macrophages. Blocking of IL-10 signaling resulted in reversal of susceptibility in the spleens and lungs of AID(-/-)µS(-/-) mice. These data support the hypothesis that B cells can modulate immunity to Mtb in an organ specific manner via the modulation of cytokine production and macrophage activation. PMID:23613902

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

    Science.gov (United States)

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

    2016-01-01

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

  7. 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.

  8. The Relationship between B-cell Epitope and Mimotope Sequences.

    Science.gov (United States)

    Zhang, Chunhua; Li, Yunyun; Tang, Weina; Zhou, Zhiguo; Sun, Pingping; Ma, Zhiqiang

    2016-01-01

    B-cell epitope is a group of residues which is on the surface of an antigen. It invokes humoral responses. Locating B-cell epitope is important for effective vaccine design, and the development of diagnostic reagents. Mimotope-based B-cell epitope prediction method is a kind of conformational B-cell epitope prediction, and the core idea of the method is mapping the mimotope sequences which are obtained from a random phage display library. However, current mimotope-based B-cell epitope prediction methods cannot maintain a high degree of satisfaction in the circumstances of employing only mimotope sequences. In this study, we did a multi-perspective analysis on parameters for conformational B-cell epitopes and characteristics between epitope and mimotope on a benchmark datasets which contains 67 mimotope sets, corresponding to 40 unique complex structures. In these 67 cases, there are 25 antigen-antibody complexes and 42 protein-protein interactions. We analyzed the two parts separately. The results showed the mimotope sequences do have some epitope features, but there are also some epitope properties that mimotope sequences do not contain. In addition, the numbers of epitope segments with different lengths were obviously different between the antigen-antibody complexes and the protein-protein interactions. This study reflects how similar do mimotope sequence and genuine epitopes have; and evaluates existing mimotope-based B-cell epitope prediction methods from a novel viewpoint. PMID:26715528

  9. YY1 Is Required for Germinal Center B Cell Development

    Science.gov (United States)

    Vuyyuru, Raja; Jha, Vibha; Hodewadekar, Suchita; Manser, Tim; Atchison, Michael L.

    2016-01-01

    YY1 has been implicated as a master regulator of germinal center B cell development as YY1 binding sites are frequently present in promoters of germinal center-expressed genes. YY1 is known to be important for other stages of B cell development including the pro-B and pre-B cells stages. To determine if YY1 plays a critical role in germinal center development, we evaluated YY1 expression during B cell development, and used a YY1 conditional knock-out approach for deletion of YY1 in germinal center B cells (CRE driven by the immunoglobulin heavy chain γ1 switch region promoter; γ1-CRE). We found that YY1 is most highly expressed in germinal center B cells and is increased 3 fold in splenic B cells activated by treatment with anti-IgM and anti-CD40. In addition, deletion of the yy1 gene by action of γ1-CRE recombinase resulted in significant loss of GC cells in both un-immunized and immunized contexts with corresponding loss of serum IgG1. Our results show a crucial role for YY1 in the germinal center reaction. PMID:27167731

  10. CCR 20th anniversary commentary: Radioactive Drones for B-cell lymphoma.

    Science.gov (United States)

    Knox, Susan J; Levy, Ronald

    2015-02-01

    In a study published in the March 1, 1996, issue of Clinical Cancer Research, Knox and colleagues (1) demonstrated the safety and efficacy of Yttirium-90 ((90)Y)-anti-CD20 monoclonal antibody therapy, as well as the benefit of preinfusion of unlabeled antibody on radiolabeled antibody biodistribution. Subsequent clinical trials with this radiolabeled antibody led to regulatory approval of this treatment for B-cell lymphoma. See related article by Knox et al., Clin Cancer Res 1996;2(3) Mar 1996; 457-70. PMID:25646179

  11. The role of B-cell receptor inhibitors in the treatment of patients with chronic lymphocytic leukemia.

    Science.gov (United States)

    Wiestner, Adrian

    2015-12-01

    Chronic lymphocytic leukemia is a malignancy of mature auto-reactive B cells. Genetic and functional studies implicate B-cell receptor signaling as a pivotal pathway in its pathogenesis. Full B-cell receptor activation requires tumor-microenvironment interactions in lymphoid tissues. Spleen tyrosine kinase, Bruton's tyrosine kinase, and the phosphatidylinositol 3-kinase (PI3K) δ isoform are essential for B-cell receptor signal transduction but also mediate the effect of other pathways engaged in chronic lymphocytic leukemia cells in the tissue-microenvironment. Orally bioavailable inhibitors of spleen tyrosine kinase, Bruton's tyrosine kinase, or PI3Kδ, induce high rates of durable responses. Ibrutinib, a covalent inhibitor of Bruton's tyrosine kinase, and idelalisib, a selective inhibitor of PI3Kδ, have obtained regulatory approval in chronic lymphocytic leukemia. Ibrutinib and idelalisib are active in patients with high-risk features, achieving superior disease control in difficult-to-treat patients than prior best therapy, making them the preferred agents for chronic lymphocytic leukemia with TP53 aberrations and for patients resistant to chemoimmunotherapy. In randomized trials, both ibrutinib, versus ofatumumab, and idelalisib in combination with rituximab, versus placebo with rituximab improved survival in relapsed/refractory chronic lymphocytic leukemia. Responses to B-cell receptor inhibitors are mostly partial, and within clinical trials treatment is continued until progression or occurrence of intolerable side effects. Ibrutinib and idelalisib are, overall, well tolerated; notable adverse events include increased bruising and incidence of atrial fibrillation on ibrutinib and colitis, pneumonitis and transaminase elevations on idelalisib. Randomized trials investigate the role of B-cell receptor inhibitors in first-line therapy and the benefit of combinations. This review discusses the biological basis for targeted therapy of chronic lymphocytic

  12. Bruton’s tyrosine kinase inhibitors and their clinical potential in the treatment of B-cell malignancies: focus on ibrutinib

    OpenAIRE

    Aalipour, Amin; Advani, Ranjana H.

    2014-01-01

    Aberrant signaling of the B-cell receptor pathway has been linked to the development and maintenance of B-cell malignancies. Bruton’s tyrosine kinase (BTK), a protein early in this pathway, has emerged as a new therapeutic target in a variety of such malignancies. Ibrutinib, the most clinically advanced small molecule inhibitor of BTK, has demonstrated impressive tolerability and activity in a range of B-cell lymphomas which led to its recent approval for relapsed mantle cell lymphoma and chr...

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

    Science.gov (United States)

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

    2016-02-01

    Hematopoietic stem cells are capable of self-renewal or differentiation along three main lineages: myeloid, erythroid, and lymphoid. One of the earliest lineage decisions for blood progenitor cells is whether to adopt the lymphoid or myeloid fate. Previous work had shown that myocyte enhancer factor 2C (MEF2C) is indispensable for the lymphoid fate decision, yet the specific mechanism of action remained unclear. Here, we have identified early B cell factor-1 (EBF1) as a co-regulator of gene expression with MEF2C. A genome-wide survey of MEF2C and EBF1 binding sites identified a subset of B cell-specific genes that they target. We also determined that the p38 MAPK pathway activates MEF2C to drive B cell differentiation. Mef2c knockout mice showed reduced B lymphoid-specific gene expression as well as increased myeloid gene expression, consistent with MEF2C's role as a lineage fate regulator. This is further supported by interaction between MEF2C and the histone deacetylase, HDAC7, revealing a likely mechanism to repress the myeloid transcription program. This study thus elucidates both activation and repression mechanisms, identifies regulatory partners, and downstream targets by which MEF2C regulates lymphoid-specific differentiation. PMID:26900922

  14. HIV-dependent depletion of influenza-specific memory B cells impacts B cell responsiveness to seasonal influenza immunisation.

    Science.gov (United States)

    Wheatley, Adam K; Kristensen, Anne B; Lay, William N; Kent, Stephen J

    2016-01-01

    Infection with HIV drives significant alterations in B cell phenotype and function that can markedly influence antibody responses to immunisation. Anti-retroviral therapy (ART) can partially reverse many aspects of B cell dysregulation, however complete normalisation of vaccine responsiveness is not always observed. Here we examine the effects of underlying HIV infection upon humoral immunity to seasonal influenza vaccines. Serological and memory B cell responses were assessed in 26 HIV+ subjects receiving ART and 30 healthy controls immunised with the 2015 Southern Hemisphere trivalent inactivated influenza vaccine (IIV3). Frequencies and phenotypes of influenza hemagglutinin (HA)-specific B cells were assessed by flow cytometry using recombinant HA probes. Serum antibody was measured using hemagglutination inhibition assays. Serological responses to IIV3 were comparable between HIV+ and HIV- subjects. Likewise, the activation and expansion of memory B cell populations specific for vaccine-component influenza strains was observed in both cohorts, however peak frequencies were diminished in HIV+ subjects compared to uninfected controls. Lower circulating frequencies of memory B cells recognising vaccine-component and historical influenza strains were observed in HIV+ subjects at baseline, that were generally restored to levels comparable with HIV- controls post-vaccination. HIV infection is therefore associated with depletion of selected HA-specific memory B cell pools. PMID:27220898

  15. HIV-dependent depletion of influenza-specific memory B cells impacts B cell responsiveness to seasonal influenza immunisation

    Science.gov (United States)

    Wheatley, Adam K.; Kristensen, Anne B.; Lay, William N.; Kent, Stephen J.

    2016-01-01

    Infection with HIV drives significant alterations in B cell phenotype and function that can markedly influence antibody responses to immunisation. Anti-retroviral therapy (ART) can partially reverse many aspects of B cell dysregulation, however complete normalisation of vaccine responsiveness is not always observed. Here we examine the effects of underlying HIV infection upon humoral immunity to seasonal influenza vaccines. Serological and memory B cell responses were assessed in 26 HIV+ subjects receiving ART and 30 healthy controls immunised with the 2015 Southern Hemisphere trivalent inactivated influenza vaccine (IIV3). Frequencies and phenotypes of influenza hemagglutinin (HA)-specific B cells were assessed by flow cytometry using recombinant HA probes. Serum antibody was measured using hemagglutination inhibition assays. Serological responses to IIV3 were comparable between HIV+ and HIV− subjects. Likewise, the activation and expansion of memory B cell populations specific for vaccine-component influenza strains was observed in both cohorts, however peak frequencies were diminished in HIV+ subjects compared to uninfected controls. Lower circulating frequencies of memory B cells recognising vaccine-component and historical influenza strains were observed in HIV+ subjects at baseline, that were generally restored to levels comparable with HIV− controls post-vaccination. HIV infection is therefore associated with depletion of selected HA-specific memory B cell pools. PMID:27220898

  16. B-Cell waste classification sampling and analysis plan

    International Nuclear Information System (INIS)

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

  17. B-Cell waste classification sampling and analysis plan

    Energy Technology Data Exchange (ETDEWEB)

    HOBART, R.L.

    1999-09-22

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

  18. B-cell survival factors in autoimmune rheumatic disorders

    Science.gov (United States)

    Morais, Sandra A.; Vilas-Boas, Andreia

    2015-01-01

    Autoimmune rheumatic disorders have complex etiopathogenetic mechanisms in which B cells play a central role. The importance of factors stimulating B cells, notably the B-cell activating factor (BAFF) and A proliferation inducing ligand (APRIL) axis is now recognized. BAFF and APRIL are cytokines essential for B-cell proliferation and survival from the immature stages to the development of plasma cells. Their levels are increased in some subsets of patients with autoimmune disorders. Several recent biologic drugs have been developed to block this axis, namely belimumab [already licensed for systemic lupus erythematosus (SLE) treatment], tabalumab, atacicept and blisibimod. Many clinical trials to evaluate the safety and efficacy of these drugs in several autoimmune disorders are ongoing, or have been completed recently. This review updates the information on the use of biologic agents blocking BAFF/APRIL for patients with SLE, rheumatoid arthritis, Sjögren’s syndrome and myositis. PMID:26288664

  19. Quantifying evolutionary constraints on B-cell affinity maturation

    OpenAIRE

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

    2015-01-01

    The antibody repertoire of each individual is continuously updated by the evolutionary process of B-cell receptor (BCR) mutation and selection. It has recently become possible to gain detailed information concerning this process through high-throughput sequencing. Here, we develop modern statistical molecular evolution methods for the analysis of B-cell sequence data, and then apply them to a very deep short-read dataset of BCRs. We find that the substitution process is conserved across indiv...

  20. Interleukin 2-induced proliferation of leukemic human B cells

    OpenAIRE

    1985-01-01

    The proliferative responses of purified leukemic human B cells from nine B cell chronic lymphocytic leukemias to recombinant interleukin 2 (IL-2), spontaneously, and after preactivation by Staphylococcus aureus Cowan I (SAC) or anti-mu antibodies were studied. Three patterns of response were observed: (a) no response (three cases); (b) a moderate spontaneous response enhanced by anti-mu (one case); (c) a high proliferative response after preactivation by anti-mu and/or SAC (five cases). IL-2 ...

  1. Trafficking of B cell antigen in lymph nodes

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Degn, Søren Egedal; Pitcher, Lisa A.; Woodruff, Matthew; Heesters, Balthasar A.; Carroll, Michael C.

    2011-01-01

    The clonal selection theory first proposed by Macfarlane Burnet is a cornerstone of immunology ( 1 ). At the time, it revolutionized the thinking of immunologists because it provided a simple explanation for lymphocyte specificity, immunological memory, and elimination of self-reactive clones ( 2...... microscopy ( 4, 5 ) have provided new insights into the trafficking of B cells and their antigen. In this review, we summarize these advances in the context of our current view of B cell circulation and activation....

  2. ALVAC-mediated gene transfer is efficient in lymphoid malignancies of T-and early B-cell origin, but not in tumors arising from mature B-cells.

    Science.gov (United States)

    Gitelson, E; Ghose, A; Buckstein, R; Imrie, K; Lim, M S; Reis, M; Spaner, D; Tartaglia, J; Berinstein, N L

    2001-09-01

    Natural attenuation of ALVAC virus in mammals makes it an attractive vector for cancer vaccine therapy of immunocompromised hosts, such as patients with lymphoid malignancies. However, the transduction efficiency of ALVAC constructs in lymphoid tumors has not yet been characterized. We studied a wide spectrum of human T- and B-cell leukemia and lymphomas and found significant heterogeneity of the ALVAC-mediated gene product expression in these tumors. While ALVAC-B7.1, ALVAC-B7.2, or ALVAC-luciferase vectors effectively expressed recombinant genes in malignancies arising from T- or early B-cell precursors, negative or low expression of ALVAC recombinant genes occurred in tumors arising from mature B-cells. We showed that ALVAC-encoded B7.1 or B7.2 was continuously expressed on the infected, and subsequently irradiated, leukemia cells, and only cells with ALVAC-mediated expression of costimulatory molecules (but not unmodified leukemia cells or those infected with the ALVAC-parental vector) induced significant proliferation and IFN-gamma production by alloreactive T-cells. These data provide the rationale for clinical studies using the ALVAC vector system for gene transfer into lymphoid tumors of T- and early B-cell origin to render them more immunogenic, while alternative strategies should be considered for immunotherapy of mature B-cell malignancies. PMID:11676394

  3. Specific Btk inhibition suppresses B cell- and myeloid cell-mediated arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Di Paolo, Julie A.; Huang, Tao; Balazs, Mercedesz; Barbosa, James; Barck, Kai H.; Bravo, Brandon J.; Carano, Richard A.D.; Darrow, James; Davies, Douglas R.; DeForge, Laura E.; Diehl, Lauri; Ferrando, Ronald; Gallion, Steven L.; Giannetti, Anthony M.; Gribling, Peter; Hurez, Vincent; Hymowitz, Sarah G.; Jones, Randall; Kropf, Jeffrey E.; Lee, Wyne P.; Maciejewski, Patricia M.; Mitchell, Scott A.; Rong, Hong; Staker, Bart L.; Whitney, J. Andrew; Yeh, Sherry; Young, Wendy B.; Yu, Christine; Zhang, Juan; Reif, Karin; Currie, Kevin S. (CGI); (Emerald); (Genentech)

    2011-09-20

    Bruton's tyrosine kinase (Btk) is a therapeutic target for rheumatoid arthritis, but the cellular and molecular mechanisms by which Btk mediates inflammation are poorly understood. Here we describe the discovery of CGI1746, a small-molecule Btk inhibitor chemotype with a new binding mode that stabilizes an inactive nonphosphorylated enzyme conformation. CGI1746 has exquisite selectivity for Btk and inhibits both auto- and transphosphorylation steps necessary for enzyme activation. Using CGI1746, we demonstrate that Btk regulates inflammatory arthritis by two distinct mechanisms. CGI1746 blocks B cell receptor-dependent B cell proliferation and in prophylactic regimens reduces autoantibody levels in collagen-induced arthritis. In macrophages, Btk inhibition abolishes Fc{gamma}RIII-induced TNF{alpha}, IL-1{beta} and IL-6 production. Accordingly, in myeloid- and Fc{gamma}R-dependent autoantibody-induced arthritis, CGI1746 decreases cytokine levels within joints and ameliorates disease. These results provide new understanding of the function of Btk in both B cell- or myeloid cell-driven disease processes and provide a compelling rationale for targeting Btk in rheumatoid arthritis.

  4. Pro-Apoptotic Activity of New Honokiol/Triphenylmethane Analogues in B-Cell Lymphoid Malignancies.

    Science.gov (United States)

    Mędra, Aleksandra; Witkowska, Magdalena; Majchrzak, Agata; Cebula-Obrzut, Barbara; Bonner, Michael Y; Robak, Tadeusz; Arbiser, Jack L; Smolewski, Piotr

    2016-01-01

    Honokiol and triphenylmethanes are small molecules with anti-tumor properties. Recently, we synthesized new honokiol analogues (HAs) that possess common features of both groups. We assessed the anti-tumor effectiveness of HAs in B-cell leukemia/lymphoma cells, namely in chronic lymphocytic leukemia (CLL) cells ex vivo and in pre-B-cell acute lymphoblastic leukemia (Nalm-6), Burkitt lymphoma (BL; Raji), diffuse large B-cell lymphoma (DLBCL; Toledo) and multiple myeloma (MM; RPMI 8226) cell lines. Four of these compounds appeared to be significantly active against the majority of cells examined, with no significant impact on healthy lymphocytes. These active HAs induced caspase-dependent apoptosis, causing significant deregulation of several apoptosis-regulating proteins. Overall, these compounds downregulated Bcl-2 and XIAP and upregulated Bax, Bak and survivin proteins. In conclusion, some of the HAs are potent tumor-selective inducers of apoptosis in ex vivo CLL and in BL, DLBCL and MM cells in vitro. Further preclinical studies of these agents are recommended. PMID:27483232

  5. Different sensitivity of germinal center B cell-like diffuse large B cell lymphoma cells towards ibrutinib treatment

    OpenAIRE

    Zheng, Xiaohui; Ding, Ning; Song, Yuqin; Feng, Lixia; Zhu, Jun

    2014-01-01

    Background Although rituximab in the combination of CHOP chemotherapy has been widely used as the standard treatment for several kinds of B-cell non-Hodgkin lymphoma (B-NHL), a great number of B-NHL patients treated with this immunotherapy still develop primary and secondary resistance. Recently Bruton’s tyrosine kinase (Btk) inhibitor ibrutinib showed promising therapeutic effect in relapsed/refractory CLL and B-cell NHL, which provided essential alternatives for these patients. Methods The ...

  6. Presentation of antigen by B cells subsets. Pt. 1. Lyb-5+ and Lyb-5- B cells differ in ability to stimulate specific T cells

    International Nuclear Information System (INIS)

    We have examined the antigen presenting cell (APC) function of different B cells. Resident, peritoneal B cells from normal mice were more efficient than splenic B cells in presenting antigen to CD4+ T cell lines. Peritoneal B cells from X-linked immunodeficient (Xid) mice, by contrast, stimulated no detectable responses. Xid splenic B cells were much less efficient APC than normal splenic B cells. B cells from neonatal mice also were very poor APC until the mice were 3 to 4 weeks old. Xid B cells presented antigen to T cell hybridomas as well as normal B cells showing that they process antigen normally. Thus, the defect is most likely in providing secondary signals. The ability of B cells to present antigen efficiency correlates with the percentage of B cells reported to express the Lyb-5 antigen. Anti-Lyb-5 serum and complement abrogated the APC activity of B cells suggesting that Lyb-5+, but not Lyb-5- cells are efficient APC. We also found that activated and resting normal splenic B cells, separated by buoyant density, presented antigen equally. Both populations also contained Lyb-5+ B cells although they were a larger fraction of the activated cells. Lyb-5 is now thought to be an activation antigen rather than a differentiation antigen. If this idea is correct, then our data indicate that anti-Lyb-5 more cleanly separates activated and resting B cells than buoyant density techniques. (author). 38 refs, 7 figs, 1 tab

  7. The B-cell receptor orchestrates environment-mediated lymphoma survival and drug resistance in B-cell malignancies.

    Science.gov (United States)

    Shain, K H; Tao, J

    2014-08-01

    Specific niches within the lymphoma tumor microenvironment (TME) provide sanctuary for subpopulations of tumor cells through stromal cell-tumor cell interactions. These interactions notably dictate growth, response to therapy and resistance of residual malignant B cells to therapeutic agents. This minimal residual disease (MRD) remains a major challenge in the treatment of B-cell malignancies and contributes to subsequent disease relapse. B-cell receptor (BCR) signaling has emerged as essential mediator of B-cell homing, survival and environment-mediated drug resistance (EMDR). Central to EMDR are chemokine- and integrin-mediated interactions between lymphoma and the TME. Further, stromal cell-B cell adhesion confers a sustained BCR signaling leading to chemokine and integrin activation. Recently, the inhibitors of BCR signaling have garnered a substantial clinical interest because of their effectiveness in B-cell disorders. The efficacy of these agents is, at least in part, attributed to attenuation of BCR-dependent lymphoma-TME interactions. In this review, we discuss the pivotal role of BCR signaling in the integration of intrinsic and extrinsic determinants of TME-mediated lymphoma survival and drug resistance. PMID:24037527

  8. Safety and Tolerability Study of PCI-32765 in B Cell Lymphoma and Chronic Lymphocytic Leukemia

    Science.gov (United States)

    2016-04-26

    B-cell Chronic Lymphocytic Leukemia; Small Lymphocytic Lymphoma; Diffuse Well-differentiated Lymphocytic Lymphoma; B Cell Lymphoma; Follicular Lymphoma,; Mantle Cell Lymphoma; Non-Hodgkin's Lymphoma; Waldenstrom Macroglobulinemia; Burkitt Lymphoma; B-Cell Diffuse Lymphoma

  9. TIM-1 signaling in B cells regulates antibody production

    International Nuclear Information System (INIS)

    Highlights: → TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. → Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. → TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3+ anti-CD28-stimulated CD4+ T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.

  10. Regulation of germinal center B-cell differentiation.

    Science.gov (United States)

    Zhang, Yang; Garcia-Ibanez, Laura; Toellner, Kai-Michael

    2016-03-01

    Germinal centers (GC) are the main sites where antigen-activated B-cell clones expand and undergo immunoglobulin gene hypermutation and selection. Iterations of this process will lead to affinity maturation, replicating Darwinian evolution on the cellular level. GC B-cell selection can lead to four different outcomes: further expansion and evolution, apoptosis (non-selection), or output from the GC with differentiation into memory B cells or plasma cells. T-helper cells in GC have been shown to have a central role in regulating B-cell selection by sensing the density of major histocompatibility complex (MHC):peptide antigen complexes. Antigen is provided on follicular dendritic cells in the form of immune complex. Antibody on these immune complexes regulates antigen accessibility by shielding antigen from B-cell receptor access. Replacement of antibody on immune complexes by antibody generated from GC-derived plasma cell output will gradually reduce the availability of antigen. This antibody feedback can lead to a situation where a slow rise in selection stringency caused by a changing environment leads to directional evolution toward higher affinity antibody. PMID:26864101

  11. B-cell depletion in the treatment of lupus nephritis.

    Science.gov (United States)

    Gregersen, Jon W; Jayne, David R W

    2012-09-01

    Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that is clinically heterogeneous and affects multiple organs. Lupus nephritis is the most frequent severe manifestation of SLE. Conventional immunosuppressive therapy has increased the life expectancy of patients diagnosed with lupus nephritis, but only 70-80% of patients respond to this treatment and its adverse effects are considerable. B cells are central to the pathogenesis of SLE and are, therefore, an attractive therapeutic target. B-cell depletion has been used successfully to treat other autoimmune diseases, such as rheumatoid arthritis and antineutrophil cytoplasmic antibody-associated vasculitis, and many case reports and small nonrandomized trials of B-cell-depleting agents in patients with lupus nephritis have reported positive results. By contrast, two large placebo-controlled trials designed to investigate the efficacy of the B-cell-depleting agents rituximab and ocrelizumab as a treatment for lupus nephritis, failed to meet their primary efficacy end points (LUNAR and BELONG, respectively). This Review discusses the current evidence on the use of B-cell depletion in the treatment of lupus nephritis, which is derived from case studies and clinical trials including a total of over 800 patients. PMID:22801948

  12. Novel Therapies for Aggressive B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Kenneth A. Foon

    2012-01-01

    Full Text Available Aggressive B-cell lymphoma (BCL comprises a heterogeneous group of malignancies, including diffuse large B-cell lymphoma (DLBCL, Burkitt lymphoma, and mantle cell lymphoma (MCL. DLBCL, with its 3 subtypes, is the most common type of lymphoma. Advances in chemoimmunotherapy have substantially improved disease control. However, depending on the subtype, patients with DLBCL still exhibit substantially different survival rates. In MCL, a mature B-cell lymphoma, the addition of rituximab to conventional chemotherapy regimens has increased response rates, but not survival. Burkitt lymphoma, the most aggressive BCL, is characterized by a high proliferative index and requires more intensive chemotherapy regimens than DLBCL. Hence, there is a need for more effective therapies for all three diseases. Increased understanding of the molecular features of aggressive BCL has led to the development of a range of novel therapies, many of which target the tumor in a tailored manner and are summarized in this paper.

  13. 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

    2015-09-01

    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

  14. Microenvironment-Centred Dynamics in Aggressive B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Matilde Cacciatore

    2012-01-01

    Full Text Available Aggressive B-cell lymphomas share high proliferative and invasive attitudes and dismal prognosis despite heterogeneous biological features. In the interchained sequence of events leading to cancer progression, neoplastic clone-intrinsic molecular events play a major role. Nevertheless, microenvironment-related cues have progressively come into focus as true determinants for this process. The cancer-associated microenvironment is a complex network of nonneoplastic immune and stromal cells embedded in extracellular components, giving rise to a multifarious crosstalk with neoplastic cells towards the induction of a supportive milieu. The immunological and stromal microenvironments have been classically regarded as essential partners of indolent lymphomas, while considered mainly negligible in the setting of aggressive B-cell lymphomas that, by their nature, are less reliant on external stimuli. By this paper we try to delineate the cardinal microenvironment-centred dynamics exerting an influence over lymphoid clone progression in aggressive B-cell lymphomas.

  15. Evolution of B-cell malignancy; Pre-B-cell leukemia resulting from MYC activation in a B-cell neoplasm with a rearranged BCL2 gene

    International Nuclear Information System (INIS)

    The authors have analyzed the molecular genetics of the breakpoints involved in the t(8;14) and t(14;18) translocations of an acute pre-B-cell leukemia from a patient with a history of follicular lymphoma. In this patient's leukemic cells, the breakpoint of the t(14;18) translocation occurred in the major breakpoint-cluster region of the BCL2 gene and became linked to the JH4 joining-region gene segment of the immunoglobulin heavy-chain locus on the 14q+ chromosome as previously observed in follicular lymphoma. An N region and heptamer and nonamer signal sequences indicated that this translocation occurred as a mistake in VH-DH-JH joining (where VH and DH are the variable and diversity segments). In the t(8;14) translocation, the breakpoint was located immediately 5' of the first exon of the MYC protooncogene, which was juxtaposed with the Cγ2 constant gene segment of the second 14q+ chromosome. The finding of repeated sequences typical of switch regions suggested that this translocation occurred during heavy-chain isotype switching, resulting in progression to pre-B-cell leukemia with both the 5(8;14) and the t(14;18) translocations. The terminal deoxynucleotidyltransferase-positive phenotype of the patient's leukemic cells further suggests that the pre-B-cell leukemia was derived from a pre-B cell carrying a t(14;18) translocation in the original follicular lymphoma. The polymerase chain reaction method was then used to identify cancer cells in the bone marrow of the patient

  16. Identification and expression profiling of regulatory molecules involved in immune homeostasis in the silkworm, Bombyx mori%家蚕免疫稳态调控分子的鉴定和表达模式分析

    Institute of Scientific and Technical Information of China (English)

    王菲; 李亚明; 化晓婷; 夏庆友

    2012-01-01

    maintenance Of insect immune homeostasis requires prompt activation and down-modulation of the key transcriptional factors: Dorsa/Dif in Toll signaling pathway or Relish in IMD signaling pathway. Several regulatory molecules which modulate the stability or activity of the transcriptional factors in immune response have been identified in Drosophila and some other insects- Mutation or silencing of these molecules leads to over activation of immune system. So far there is no report about the regulatory molecules limiting immune signaling in the silkworm, Bombyx mori. In this study, several molecules which are predicted to be involved in immune homeostasis, including Wnt family members, Ubc9, FAF and POSH, were identified in the silkworm genome by comparative genomic analysis. The expression patterns of these molecules in multiple tissues after microbial infection were recorded, and the results showed that their expression levels generally decreased after microbial infection. Although an increase of more than 1. 5-folds in expression level was observed in certain tissues, a rapid decrease followed and the high level was not maintained. Interestingly, the correspondence between the expression patterns of these molecules and the particular signaling pathway that microbes induced varied in different tissues. This is the first report of the regulatory molecules involved in silkworm immune homeostasis, which provides reference for further investigation on the molecular mechanism of immuno-negative modulation in the ilkworm.%昆虫免疫稳态的维持有赖于准确地激活和有效地抑制Toll或IMD信号通路中的关键转录因子——Dorsal/Dif或Relish.在果蝇等昆虫中,已报道了多种降低转录因子稳定性和活性的免疫稳态调控分子,突变或敲除这类分子导致免疫系统的过度激活.对家蚕Bombyx mori免疫信号通路的研究中,至今为止尚无对这类分子的探索.本研究通过比较基因组学,在家蚕基因组中

  17. Editing Anti-DNA B Cells by Vλx

    OpenAIRE

    Li, Yijin; Louzoun, Yoram; Weigert, Martin

    2004-01-01

    Receptor editing is performed by replacement of Vκ genes that contribute to autoreactivity. In addition, the Cκ locus can be deleted by Vκ rearrangement to intronic or 3′ of Cκ RS sequences (also referred to as κ deletion elements). B cells that delete the Cκ can then express λ light chains. However, the λ locus, either of man or mouse, does not allow V gene replacement. Nor does it appear to be deleted. Therefore, editing of autoreactive λ B cells may require alternative pathways. We have fo...

  18. Intranasal application of immuno-regulatory molecules: a method to investigate strategies for local cancer immuno-therapies in the lung

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Sarah Reppert, Katerina Andreev, Sandra Wittmann & Susetta Finotto ### Abstract Lung cancer is one of the most frequently occurring cancer types. Successful lung cancer therapies in patients require preliminary investigations of promising therapeutic reagents in animal models. This protocol describes a method to induce lung tumours in mice and to deliver an immunoregulatory molecule directly to the lung by intranasal application. Here we describe the usage of murine ce...

  19. Human B Cell-Derived Lymphoblastoid Cell Lines Constitutively Produce Fas Ligand and Secrete MHCII+FasL+ Killer Exosomes

    OpenAIRE

    Klinker, Matthew W.; Lizzio, Vincent; Reed, Tamra J.; Fox, David A.; Lundy, Steven K.

    2014-01-01

    Immune suppression mediated by exosomes is an emerging concept with potentially immense utility for immunotherapy in a variety of inflammatory contexts, including allogeneic transplantation. Exosomes containing the apoptosis-inducing molecule Fas ligand (FasL) have demonstrated efficacy in inhibiting antigen-specific immune responses upon adoptive transfer in animal models. We report here that a very high frequency of human B cell-derived lymphoblastoid cell lines (LCL) constitutively produce...

  20. Inhibition of COP9-signalosome (CSN) deneddylating activity and tumor growth of diffuse large B-cell lymphomas by doxycycline

    OpenAIRE

    Pulvino, Mary; Chen, Luojing; Oleksyn, David; Li, Jing; Compitello, George; Rossi, Randy; Spence, Stephen; Balakrishnan, Vijaya; Jordan, Craig; Poligone, Brian; Casulo, Carla; Burack, Richard; Shapiro, Joel L.; Bernstein, Steven; Friedberg, Jonathan W.

    2015-01-01

    In searching for small-molecule compounds that inhibit proliferation and survival of diffuse large B-cell lymphoma (DLBCL) cells and may, therefore, be exploited as potential therapeutic agents for this disease, we identified the commonly used and well-tolerated antibiotic doxycycline as a strong candidate. Here, we demonstrate that doxycycline inhibits the growth of DLBCL cells both in vitro and in mouse xenograft models. In addition, we show that doxycycline accumulates in DLBCL cells to hi...

  1. Transcriptome Analysis of B Cell Immune Functions in Periodontitis: Mucosal Tissue Responses to the Oral Microbiome in Aging.

    Science.gov (United States)

    Ebersole, Jeffrey L; Kirakodu, Sreenatha S; Novak, M John; Orraca, Luis; Martinez, Janis Gonzalez; Cunningham, Larry L; Thomas, Mark V; Stromberg, Arnold; Pandruvada, Subramanya N; Gonzalez, Octavio A

    2016-01-01

    Evidence has shown activation of T and B cells in gingival tissues in experimental models and in humans diagnosed with periodontitis. The results of this adaptive immune response are noted both locally and systemically with antigenic specificity for an array of oral bacteria, including periodontopathic species, e.g., Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. It has been recognized through epidemiological studies and clinical observations that the prevalence of periodontitis increases with age. This report describes our studies evaluating gingival tissue transcriptomes in humans and specifically exploiting the use of a non-human primate model of naturally occurring periodontitis to delineate gingival mucosal tissue gene expression profiles focusing on cells/genes critical for the development of humoral adaptive immune responses. Patterns of B cell and plasmacyte genes were altered in aging healthy gingival tissues. Substantial increases in a large number of genes reflecting antigen-dependent activation, B cell activation, B cell proliferation, and B cell differentiation/maturation were observed in periodontitis in adults and aged animals. Finally, evaluation of the relationship of these gene expression patterns with those of various tissue destructive molecules (MMP2, MMP9, CTSK, TNFα, and RANKL) showed a greater frequency of positive correlations in healthy tissues versus periodontitis tissues, with only MMP9 correlations similar between the two tissue types. These results are consistent with B cell response activities in healthy tissues potentially contributing to muting the effects of the tissue destructive biomolecules, whereas with periodontitis this relationship is adversely affected and enabling a progression of tissue destructive events. PMID:27486459

  2. Transcriptome Analysis of B Cell Immune Functions in Periodontitis: Mucosal Tissue Responses to the Oral Microbiome in Aging

    Science.gov (United States)

    Ebersole, Jeffrey L.; Kirakodu, Sreenatha S.; Novak, M. John; Orraca, Luis; Martinez, Janis Gonzalez; Cunningham, Larry L.; Thomas, Mark V.; Stromberg, Arnold; Pandruvada, Subramanya N.; Gonzalez, Octavio A.

    2016-01-01

    Evidence has shown activation of T and B cells in gingival tissues in experimental models and in humans diagnosed with periodontitis. The results of this adaptive immune response are noted both locally and systemically with antigenic specificity for an array of oral bacteria, including periodontopathic species, e.g., Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. It has been recognized through epidemiological studies and clinical observations that the prevalence of periodontitis increases with age. This report describes our studies evaluating gingival tissue transcriptomes in humans and specifically exploiting the use of a non-human primate model of naturally occurring periodontitis to delineate gingival mucosal tissue gene expression profiles focusing on cells/genes critical for the development of humoral adaptive immune responses. Patterns of B cell and plasmacyte genes were altered in aging healthy gingival tissues. Substantial increases in a large number of genes reflecting antigen-dependent activation, B cell activation, B cell proliferation, and B cell differentiation/maturation were observed in periodontitis in adults and aged animals. Finally, evaluation of the relationship of these gene expression patterns with those of various tissue destructive molecules (MMP2, MMP9, CTSK, TNFα, and RANKL) showed a greater frequency of positive correlations in healthy tissues versus periodontitis tissues, with only MMP9 correlations similar between the two tissue types. These results are consistent with B cell response activities in healthy tissues potentially contributing to muting the effects of the tissue destructive biomolecules, whereas with periodontitis this relationship is adversely affected and enabling a progression of tissue destructive events. PMID:27486459

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

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    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.

  4. ATAC-seq on biobanked specimens defines a unique chromatin accessibility structure in naïve SLE B cells.

    Science.gov (United States)

    Scharer, Christopher D; Blalock, Emily L; Barwick, Benjamin G; Haines, Robert R; Wei, Chungwen; Sanz, Ignacio; Boss, Jeremy M

    2016-01-01

    Biobanking is a widespread practice for storing biological samples for future studies ranging from genotyping to RNA analysis. However, methods that probe the status of the epigenome are lacking. Here, the framework for applying the Assay for Transposase Accessible Sequencing (ATAC-seq) to biobanked specimens is described and was used to examine the accessibility landscape of naïve B cells from Systemic Lupus Erythematosus (SLE) patients undergoing disease flares. An SLE specific chromatin accessibility signature was identified. Changes in accessibility occurred at loci surrounding genes involved in B cell activation and contained motifs for transcription factors that regulate B cell activation and differentiation. These data provide evidence for an altered epigenetic programming in SLE B cells and identify loci and transcription factor networks that potentially impact disease. The ability to determine the chromatin accessibility landscape and identify cis-regulatory elements has broad application to studies using biorepositories and offers significant advantages to improve the molecular information obtained from biobanked samples. PMID:27249108

  5. B Cells Are Critical to T-cell—Mediated Antitumor Immunity Induced by a Combined Immune-Stimulatory/Conditionally Cytotoxic Therapy for Glioblastoma

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    Marianela Candolfi

    2011-10-01

    Full Text Available We have demonstrated that modifying the tumor microenvironment through intratumoral administration of adenoviral vectors (Ad encoding the conditional cytotoxic molecule, i.e., HSV1-TK and the immune-stimulatory cytokine, i.e., fms-like tyrosine kinase 3 ligand (Flt3L leads to T-cell-dependent tumor regression in rodent models of glioblastoma. We investigated the role of B cells during immune-mediated glioblastoma multiforme regression. Although treatment with Ad-TK+Ad-Flt3L induced tumor regression in 60% of wild-type (WT mice, it completely failed in B-cell-deficient Igh6-/- mice. Tumor-specific T-cell precursors were detected in Ad-TK+Ad-Flt3L-treated WT mice but not in Igh6-/- mice. The treatment also failed in WT mice depleted of total B cells or marginal zone B cells. Because we could not detect circulating antibodies against tumor cells and the treatment was equally efficient in WT mice and in mice with B-cell-specific deletion of Prdm 1 (encoding Blimp-1, in which B cells are present but unable to fully differentiate into antibody-secreting plasma cells, tumor regression in this model is not dependent on B cells’ production of tumor antigen-specific immunoglobulins. Instead, B cells seem to play a role as antigen-presenting cells (APCs. Treatment with Ad-TK+Ad-Flt3L led to an increase in the number of B cells in the cervical lymph nodes, which stimulated the proliferation of syngeneic T cells and induced clonal expansion of antitumor T cells. Our data show that B cells act as APCs, playing a critical role in clonal expansion of tumor antigen-specific T cells and brain tumor regression.

  6. Generation of Recombinant Monoclonal Antibodies from Immunised Mice and Rabbits via Flow Cytometry and Sorting of Antigen-Specific IgG+ Memory B Cells.

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    Dale O Starkie

    Full Text Available Single B cell screening strategies, which avoid both hybridoma fusion and combinatorial display, have emerged as important technologies for efficiently sampling the natural antibody repertoire of immunized animals and humans. Having access to a range of methods to interrogate different B cell subsets provides an attractive option to ensure large and diverse panels of high quality antibody are produced. The generation of multiple antibodies and having the ability to find rare B cell clones producing IgG with unique and desirable characteristics facilitates the identification of fit-for-purpose molecules that can be developed into therapeutic agents or research reagents. Here, we describe a multi-parameter flow cytometry single-cell sorting technique for the generation of antigen-specific recombinant monoclonal antibodies from single IgG+ memory B cells. Both mouse splenocytes and rabbit PBMC from immunised animals were used as a source of B cells. Reagents staining both B cells and other unwanted cell types enabled efficient identification of class-switched IgG+ memory B cells. Concurrent staining with antigen labelled separately with two spectrally-distinct fluorophores enabled antigen-specific B cells to be identified, i.e. those which bind to both antigen conjugates (double-positive. These cells were then typically sorted at one cell per well using FACS directly into a 96-well plate containing reverse transcriptase reaction mix. Following production of cDNA, PCR was performed to amplify cognate heavy and light chain variable region genes and generate transcriptionally-active PCR (TAP fragments. These linear expression cassettes were then used directly in a mammalian cell transfection to generate recombinant antibody for further testing. We were able to successfully generate antigen-specific recombinant antibodies from both the rabbit and mouse IgG+ memory B cell subset within one week. This included the generation of an anti-TNFR2 blocking

  7. MicroRNA expression in nodal and extranodal Diffuse Large B-cell Lymphoma

    DEFF Research Database (Denmark)

    Mandrup, Charlotte; Petersen, Anders; Højfeldt, Anne Dirks;

    manifestations, and no way to predict the potential progression from nodal to extranodal disease. miRNA are small regulatory RNA molecules with core function to repress/cleave sequence complementary mRNA targets. Abnormalities in miRNA genetics and expression are known to affect initiation and development of...

  8. Characterization of intratumoral follicular helper T cells in follicular lymphoma: role in the survival of malignant B cells

    Science.gov (United States)

    Amé-Thomas, Patricia; Le Priol, Jérôme; Yssel, Hans; Caron, Gersende; Pangault, Céline; Jean, Rachel; Martin, Nadine; Marafioti, Teresa; Gaulard, Philippe; Lamy, Thierry; Fest, Thierry; Semana, Gilbert; Tarte, Karin

    2012-01-01

    Accumulating evidences indicate that the cellular and molecular microenvironment of follicular lymphoma (FL) plays a key role in both lymphomagenesis and patient outcome. Malignant FL B cells are found admixed to specific stromal and immune cell subsets, in particular CD4pos T cells displaying phenotypic features of follicular helper T cells (TFH). The goal of our study was to functionally characterize intratumoral CD4pos T cells. We showed that CXCR5hiICOShiCD4pos T cells sorted from FL biopsies comprise at least two separate cell populations with distinct genetic and functional features: i) CD25pos follicular regulatory T cells (TFR), and ii) CD25neg TFH displaying a FL-B cell supportive activity without regulatory functions. Furthermore, despite their strong similarities with tonsil-derived TFH, purified FL-derived TFH displayed a specific gene expression profile including an overexpression of several genes potentially involved directly or indirectly in lymphomagenesis, in particular TNF, LTA, IL4, or CD40LG. Interestingly, we further demonstrated that these two last signals efficiently rescued malignant B cells from spontaneous and Rituximab-induced apoptosis. Altogether, our study demonstrates that tumor-infiltrating CD4pos T cells are more heterogeneous than previously presumed, and underlines for the first time the crucial role of TFH in the complex set of cellular interactions within FL microenvironment. PMID:22015774

  9. Th1 and Th2 help for B cells

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1995-01-01

    IL-5 (125 U/ml) synergizes with Th1 cells to induce B cell responses to IL-2, that are maintained following T-cell removal, e.g. autonomous. Th1 help in the absence of IL-5 resulted in weak or undetectable responses following T cell removal. The mechanism of IL-5 synergy involved persistence of IL-2R...

  10. Isolation of human monoclonal antibodies from peripheral blood B cells.

    Science.gov (United States)

    Huang, Jinghe; Doria-Rose, Nicole A; Longo, Nancy S; Laub, Leo; Lin, Chien-Li; Turk, Ellen; Kang, Byong H; Migueles, Stephen A; Bailer, Robert T; Mascola, John R; Connors, Mark

    2013-10-01

    Isolation of monoclonal antibodies is an important technique for understanding the specificities and characteristics of antibodies that underlie the humoral immune response to a given antigen. Here we describe a technique for isolating monoclonal antibodies from human peripheral blood mononuclear cells. The protocol includes strategies for the isolation of switch-memory B cells from peripheral blood, the culture of B cells, the removal of the supernatant for screening and the lysis of B cells in preparation for immunoglobulin heavy-chain and light-chain amplification and cloning. We have observed that the addition of cytokines IL-2, IL-21 and irradiated 3T3-msCD40L feeder cells can successfully stimulate switch-memory B cells to produce high concentrations of IgG in the supernatant. The supernatant may then be screened by appropriate assays for binding or for other functions. This protocol can be completed in 2 weeks. It is adaptable to use in other species and enables the efficient isolation of antibodies with a desired functional characteristic without prior knowledge of specificity. PMID:24030440

  11. Innate B Cells Tell ILC How It's Done.

    Science.gov (United States)

    Nguyen, Trang T T; Baumgarth, Nicole

    2016-07-19

    Innate lymphoid cells (ILCs) are known as first responders to infections and as instructors of subsequent CD4(+) T cell cytokine profiles. In this issue of Immunity, Fan and colleagues now demonstrate that even earlier responding innate-like B cells (NKB) induce these protective ILC responses. PMID:27438761

  12. In silico quantitative prediction of B-cell epitope

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    Raúl Isea

    2015-11-01

    Full Text Available This paper shows a computational approach for quantitative prediction of B cell epitopes. The function was defined, which reflects the average value of B epitopes, according to eight predictors of different B epitopes, as well as structural and energetic considerations of the origin protein. The proposed methodology could be useful to develop both dengue and chikungunya vaccines

  13. In silico quantitative prediction of B-cell epitope

    OpenAIRE

    Raúl Isea

    2015-01-01

    This paper shows a computational approach for quantitative prediction of B cell epitopes. The function was defined, which reflects the average value of B epitopes, according to eight predictors of different B epitopes, as well as structural and energetic considerations of the origin protein. The proposed methodology could be useful to develop both dengue and chikungunya vaccines

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

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    Natacha Colliou

    2015-09-01

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

  15. T follicular regulatory cells.

    Science.gov (United States)

    Sage, Peter T; Sharpe, Arlene H

    2016-05-01

    Pathogen exposure elicits production of high-affinity antibodies stimulated by T follicular helper (Tfh) cells in the germinal center reaction. Tfh cells provide both costimulation and stimulatory cytokines to B cells to facilitate affinity maturation, class switch recombination, and plasma cell differentiation within the germinal center. Under normal circumstances, the germinal center reaction results in antibodies that precisely target foreign pathogens while limiting autoimmunity and excessive inflammation. In order to have this degree of control, the immune system ensures Tfh-mediated B-cell help is regulated locally in the germinal center. The recently identified T follicular regulatory (Tfr) cell subset can migrate to the germinal center and inhibit Tfh-mediated B-cell activation and antibody production. Although many aspects of Tfr cell biology are still unclear, recent data have begun to delineate the specialized roles of Tfr cells in controlling the germinal center reaction. Here we discuss the current understanding of Tfr-cell differentiation and function and how this knowledge is providing new insights into the dynamic regulation of germinal centers, and suggesting more efficacious vaccine strategies and ways to treat antibody-mediated diseases. PMID:27088919

  16. Maternal immunization with ovalbumin prevents neonatal allergy development and up-regulates inhibitory receptor FcγRIIB expression on B cells

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    Duarte Alberto JS

    2010-03-01

    Full Text Available Abstract Background Preconception allergen immunization prevents neonatal allergen sensitization in mice by a complex interaction between regulatory cells/factors and antibodies. The present study assessed the influence of maternal immunization with ovalbumin (OVA on the immune response of 3 day-old and 3 week-old offspring immunized or non-immunized with OVA and evaluated the effect of IgG treatment during fetal development or neonatal period. Results Maternal immunization with OVA showed increased levels of FcγRIIb expression in splenic B cells of neonates, which were maintained for up to 3 weeks and not affected by additional postnatal OVA immunization. Maternal immunization also exerted a down-modulatory effect on both IL-4 and IFN-γ-secreting T cells and IL-4 and IL-12- secreting B cells. Furthermore, immunized neonates from immunized mothers showed a marked inhibition of antigen-specifc IgE Ab production and lowered Th2/Th1 cytokine levels, whereas displaying enhanced FcγRIIb expression on B cells. These offspring also showed reduced antigen-specific proliferative response and lowered B cell responsiveness. Moreover, in vitro evaluation revealed an impairment of B cell activation upon engagement of B cell antigen receptor by IgG from OVA-immunized mice. Finally, in vivo IgG transference during pregnancy or breastfeeding revealed that maternal Ab transference was able to increase regulatory cytokines, such as IL-10, in the prenatal stage; yet only the postnatal treatment prevented neonatal sensitization. None of the IgG treatments induced immunological changes in the offspring, as it was observed for those from OVA-immunized mothers. Conclusion Maternal immunization upregulates the inhibitory FcγRIIb expression on offspring B cells, avoiding skewed Th2 response and development of allergy. These findings contribute to the advancement of prophylactic strategies to prevent allergic diseases in early life.

  17. Technical advance: soluble OX40 molecule mimics regulatory T cell modulatory activity on FcεRI-dependent mast cell degranulation.

    Science.gov (United States)

    Sibilano, Riccardo; Gri, Giorgia; Frossi, Barbara; Tripodo, Claudio; Suzuki, Ryo; Rivera, Juan; MacDonald, Andrew S; Pucillo, Carlo E

    2011-10-01

    Tregs play a central role in modulating FcεRI-dependent MC effector functions in the course of the allergic response. Cellular interaction depends on the constitutive expression of OX40 on Tregs and the OX40L counterpart on MCs. Study of OX40L signaling on MCs is hampered by the need of a highly purified molecule, which triggers OX40L specifically. We now report that sOX40 mimics the physiological activity of Treg interaction by binding to activated MCs. When treated with sOX40, activated MCs showed decreased degranulation and Ca(++) influx, whereas PLC-γ2 phosphorylation remained unaffected. Once injected into experimental animals, sOX40 not only located within the endothelium but also in parenchyma, where it could be found in close proximity and apparently bound to MCs. This soluble molecule triggers MC-OX40L without the requirement of Tregs, thus allowing study of OX40L signaling pathways in MCs and in other OX40L-expressing cell populations. Importantly, as sOX40 inhibits MC degranulation, it may provide an in vivo therapeutic tool in allergic disease. PMID:21653238

  18. Germinal center B cells recognize antigen through a specialized immune synapse architecture.

    Science.gov (United States)

    Nowosad, Carla R; Spillane, Katelyn M; Tolar, Pavel

    2016-07-01

    B cell activation is regulated by B cell antigen receptor (BCR) signaling and antigen internalization in immune synapses. Using large-scale imaging across B cell subsets, we found that, in contrast with naive and memory B cells, which gathered antigen toward the synapse center before internalization, germinal center (GC) B cells extracted antigen by a distinct pathway using small peripheral clusters. Both naive and GC B cell synapses required proximal BCR signaling, but GC cells signaled less through the protein kinase C-β-NF-κB pathway and produced stronger tugging forces on the BCR, thereby more stringently regulating antigen binding. Consequently, GC B cells extracted antigen with better affinity discrimination than naive B cells, suggesting that specialized biomechanical patterns in B cell synapses regulate T cell-dependent selection of high-affinity B cells in GCs. PMID:27183103

  19. Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mi [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiao, Xiubin [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China); Liu, Lianqing, E-mail: lqliu@sia.cn [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xi, Ning, E-mail: xin@egr.msu.edu [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China); Wang, Yuechao; Dong, Zaili [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, Weijing, E-mail: zhangwj3072@163.com [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)

    2013-11-01

    CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500×500 nm{sup 2}) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells. - Highlights: • Cancer cells were recognized from healthy cells by ROR1 fluorescence labeling. • The nanoscale distribution of CD20 on cancer cells was characterized. • The distribution of CD20 was non-uniform on the surface of cancer cells.

  20. Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients

    International Nuclear Information System (INIS)

    CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500×500 nm2) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells. - Highlights: • Cancer cells were recognized from healthy cells by ROR1 fluorescence labeling. • The nanoscale distribution of CD20 on cancer cells was characterized. • The distribution of CD20 was non-uniform on the surface of cancer cells

  1. The pan-B cell marker CD22 is expressed on gastrointestinal eosinophils and negatively regulates tissue eosinophilia.

    Science.gov (United States)

    Wen, Ting; Mingler, Melissa K; Blanchard, Carine; Wahl, Benjamin; Pabst, Oliver; Rothenberg, Marc E

    2012-02-01

    CD22 is currently recognized as a B cell-specific Siglec and has been exploited therapeutically with humanized anti-CD22 mAb having been used against B cell leukemia. In this study, tissue-specific eosinophil mRNA microarray analysis identified that CD22 transcript levels of murine gastrointestinal (GI) eosinophils are 10-fold higher than those of lung eosinophils. To confirm the mRNA data at the protein level, we developed a FACS-based protocol designed to phenotype live GI eosinophils isolated from the murine lamina propria. Indeed, we found that jejunum eosinophils expressed remarkably high levels of surface CD22, similar to levels found in B cells across multiple mouse strains. In contrast, CD22 was undetectable on eosinophils from the colon, blood, thymus, spleen, uterus, peritoneal cavity, and allergen-challenged lung. Eosinophils isolated from newborn mice did not express CD22 but subsequently upregulated CD22 expression to adult levels within the first 10 d after birth. The GI lamina propria from CD22 gene-targeted mice harbored more eosinophils than wild type control mice, whereas the GI eosinophil turnover rate was unaltered in the absence of CD22. Our findings identify a novel expression pattern and tissue eosinophilia-regulating function for the "B cell-specific" inhibitory molecule CD22 on GI eosinophils. PMID:22190185

  2. iNKT-cell help to B cells: a cooperative job between innate and adaptive immune responses.

    Science.gov (United States)

    Dellabona, Paolo; Abrignani, Sergio; Casorati, Giulia

    2014-08-01

    T-cell help to B lymphocytes is one of the most important events in adaptive immune responses in health and disease. It is generally delivered by cognate CD4(+) T follicular helper (T(FH)) cells via both cell-to-cell contacts and soluble mediators, and it is essential for both the clonal expansion of antibody (Ab)-secreting B cells and memory B-cell formation. CD1d-restricted invariant natural killer T (iNKT) cells are a subset of innate-like T lymphocytes that rapidly respond to stimulation with specific lipid antigens (Ags) that are derived from infectious pathogens or stressed host cells. Activated iNKT cells produce a wide range of cytokines and upregulate costimulatory molecules that can promote activation of dendritic cells (DCs), natural killer (NK) cells, and T cells. A decade ago, we discovered that iNKT cells can help B cells to proliferate and to produce IgG Abs in vitro and in vivo. This adjuvant-like function of Ag-activated iNKT cells provides a flexible set of helper mechanisms that expand the current paradigm of T-cell-B-cell interaction and highlights the potential of iNKT-cell targeting vaccine formulations. PMID:24782127

  3. Ibrutinib Before and After Stem Cell Transplant in Treating Patients With Relapsed or Refractory Diffuse Large B-cell Lymphoma

    Science.gov (United States)

    2016-09-01

    Activated B-Cell-Like Diffuse Large B-Cell Lymphoma; B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma

  4. An intrinsic propensity of murine peritoneal B1b cells to switch to IgA in presence of TGF-β and retinoic acid.

    Directory of Open Access Journals (Sweden)

    Bishnudeo Roy

    Full Text Available AIMS: In the present study we have investigated the comparative switching propensity of murine peritoneal and splenic B cell subpopulations to IgA in presence of retinoic acid (RA and TGF-β. METHODS AND RESULTS: To study the influence of RA and TGF-β on switching of B cell subpopulations to IgA, peritoneal (B1a, B1b and B2 cells and splenic (B1a, marginal zone, and B2 B cells from normal BALB/c mice were FACS purified, cultured for 4 days in presence of RA and TGF-β and the number of IgA producing cells was determined by ELISPOT assay or FACS analysis. In presence of TGF-β, peritoneal B1b cells switched to IgA more potently than other peritoneal B cell subpopulations. When TGF-β was combined with retinoic acid (RA, switching to IgA was even more pronounced. Under these conditions, "innate" B cells like peritoneal and splenic B1 cells and MZ B cells produced IgA more readily than B2 cells. Additionally, high frequency of nucleotide exchanges indicating somatic hypermutation in VH regions was observed. Besides IgA induction, RA treatment of sorted PEC and splenic B cells led to expression of gut homing molecules - α4β7 and CCR9. Intraperitoneal transfer of RA-treated B1 cells into Rag1(-/- recipients resulted in IgA in serum and gut lavage, most efficiently amongst B1b cell recipients. CONCLUSION: Present study demonstrates the differential and synergistic effect of RA and TGF-β on switching of different B cell subpopulations to IgA and establishes the prominence of peritoneal B1b cells in switching to IgA under the influence of these two factors. Our study extends our knowledge about the existing differences among B cell subpopulations with regards to IgA production and indicates towards their differential contribution to gut associated humoral immunity.

  5. Activation of human B cells by the agonist CD40 antibody CP-870,893 and augmentation with simultaneous toll-like receptor 9 stimulation

    Directory of Open Access Journals (Sweden)

    Rüter Jens

    2009-11-01

    Full Text Available Abstract Background CD40 activation of antigen presenting cells (APC such as dendritic cells (DC and B cells plays an important role in immunological licensing of T cell immunity. Agonist CD40 antibodies have been previously shown in murine models to activate APC and enhance tumor immunity; in humans, CD40-activated DC and B cells induce tumor-specific T cells in vitro. Although clinical translation of these findings for patients with cancer has been previously limited due to the lack of a suitable and available drug, promising clinical results are now emerging from phase I studies of the agonist CD40 monoclonal antibody CP-870,893. The most prominent pharmacodynamic effect of CP-870,893 infusion is peripheral B cell modulation, but direct evidence of CP-870,893-mediated B cell activation and the potential impact on T cell reactivity has not been reported, despite increasing evidence that B cells, like DC, regulate cellular immunity. Methods Purified total CD19+ B cells, CD19+ CD27+ memory, or CD19+ CD27neg subsets from peripheral blood were stimulated in vitro with CP-870,893, in the presence or absence of the toll like receptor 9 (TLR9 ligand CpG oligodeoxynucleotide (ODN. B cell surface molecule expression and cytokine secretion were evaluated using flow cytometry. Activated B cells were used as stimulators in mixed lymphocyte reactions to evaluate their ability to induce allogeneic T cell responses. Results Incubation with CP-870,893 activated B cells, including both memory and naïve B cells, as demonstrated by upregulation of CD86, CD70, CD40, and MHC class I and II. CP-870,893-activated B cells induced T cell proliferation and T cell secretion of effector cytokines including IFN-gamma and IL-2. These effects were increased by TLR9 co-stimulation via a CpG ODN identical in sequence to a well-studied clinical grade reagent. Conclusion The CD40 mAb CP-870,893 activates both memory and naïve B cells and triggers their T cell stimulatory

  6. miR290-5p/292-5p activate the immunoglobulin kappa locus in B cell development.

    Directory of Open Access Journals (Sweden)

    Patty B Garcia

    Full Text Available Regulated expression of miRNAs influences development in a wide variety of contexts. We report here that miR290-5p (100049710 and miR292-5p (100049711 are induced at the pre-B stage of murine B cell development and that they influence assembly of the Igκ light chain gene (243469 by contributing to the activation of germline Igκ transcription (κGT. We found that upon forced over-expression of miR290-5p/292-5p in Abelson Murine Leukemia Virus (AMuLV transformed pro-B cells, two known activators of κGT, E2A (21423 and NF-κB (19697, show increased chromosomal binding to the kappa intronic enhancer. Conversely, knockdown of miR290-5p/292-5p in AMuLV pro-B cells blunts drug-induced activation of κGT. Furthermore, miR290-5p/292-5p knockdown also diminishes κGT activation, but not Rag1/2 (19373, 19374 expression, in an IL-7 dependent primary pro-B cell culture system. In addition, we identified a deficiency in κGT induction in miR290 cluster knockout mice. We hypothesize that increased expression of miR290-5p and miR292-5p contributes to the induction of κGT at the pre-B stage of B cell development through increased binding of NF-κB and E2A to kappa locus regulatory sequences.

  7. miR290-5p/292-5p activate the immunoglobulin kappa locus in B cell development.

    Science.gov (United States)

    Garcia, Patty B; Cai, Amie; Bates, Jamie G; Nolla, Hector; Schlissel, Mark S

    2012-01-01

    Regulated expression of miRNAs influences development in a wide variety of contexts. We report here that miR290-5p (100049710) and miR292-5p (100049711) are induced at the pre-B stage of murine B cell development and that they influence assembly of the Igκ light chain gene (243469) by contributing to the activation of germline Igκ transcription (κGT). We found that upon forced over-expression of miR290-5p/292-5p in Abelson Murine Leukemia Virus (AMuLV) transformed pro-B cells, two known activators of κGT, E2A (21423) and NF-κB (19697), show increased chromosomal binding to the kappa intronic enhancer. Conversely, knockdown of miR290-5p/292-5p in AMuLV pro-B cells blunts drug-induced activation of κGT. Furthermore, miR290-5p/292-5p knockdown also diminishes κGT activation, but not Rag1/2 (19373, 19374) expression, in an IL-7 dependent primary pro-B cell culture system. In addition, we identified a deficiency in κGT induction in miR290 cluster knockout mice. We hypothesize that increased expression of miR290-5p and miR292-5p contributes to the induction of κGT at the pre-B stage of B cell development through increased binding of NF-κB and E2A to kappa locus regulatory sequences. PMID:22928038

  8. 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.

  9. Mutations in the HLA class II genes leading to loss of expression of HLA-DR and HLA-DQ in diffuse large B-cell lymphoma

    NARCIS (Netherlands)

    Jordanova, ES; Philippo, K; Giphart, MJ; Schuuring, E; Kluin, PM

    2003-01-01

    Loss of expression of human leukocyte antigen (HLA) class II molecules on tumor cells affects the onset and modulation of the immune response through lack of activation of CD4(+) T lymphocytes. Previously, we showed that the frequent loss of expression of HLA class II in diffuse large B-cell lymphom

  10. Targeting Endothelial Adhesion Molecule Transcription for Treatment of Inflammatory Disease: A Proof-of-Concept Study

    Directory of Open Access Journals (Sweden)

    Liam M. Ashander

    2016-01-01

    Full Text Available Targeting the endothelial adhesion molecules that control leukocyte trafficking into a tissue has been explored as a biological therapy for inflammatory diseases. However, these molecules also participate in leukocyte migration for immune surveillance, and inhibiting the physiological level of an adhesion molecule might promote infection or malignancy. We explored the concept of targeting endothelial adhesion molecule transcription during inflammation in a human system. Intercellular adhesion molecule 1 (ICAM-1 mediates leukocyte migration across the retinal endothelium in noninfectious posterior uveitis. We observed an increase in the transcription factor, nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NF-κB1, in parallel with ICAM-1, in human retinal endothelial cells treated with tumor necrosis factor-alpha (TNF-α, and identified putative binding sites for NF-κB1 within the ICAM-1 regulatory region. We targeted induced NF-κB1 expression in endothelial cells with small interfering (siRNA. Knockdown of NF-κB1 significantly decreased cell surface expression of ICAM-1 protein induced by TNF-α but did not reduce constitutive ICAM-1 expression. Consistently, NF-κB1 knockdown significantly reduced leukocyte binding to cell monolayers in the presence of TNF-α but did not impact baseline binding. Findings of this proof-of-concept study indicate that induced transcription of endothelial adhesion molecules might be targeted therapeutically for inflammatory disease in humans.

  11. 324 Facility B-cell quality process plan

    International Nuclear Information System (INIS)

    B-Cell is currently being cleaned out (i.e., removal of equipment, fixtures and residual radioactive materials) and deactivated. TPA Milestone M-89-02 dictates that all mixed waste and equipment be removed from B-Cell by 5/31/99. The following sections describe the major activities that remain for completion of the TPA milestone. These include: Size Reduce Tank 119 and Miscellaneous Equipment; Load and Ship Low-Level Waste; Remove and Size Reduce the 1B Rack; Collect Dispersible Material from Cell Floor; Remove and Size Reduce the 2A Rack; Size Reduce the 1A Rack; Load and Ship Mixed Waste to PUREX Tunnels; and Move Spent Fuel to A-Cell;

  12. 324 Facility B-cell quality process plan

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.L.

    1998-07-29

    B-Cell is currently being cleaned out (i.e., removal of equipment, fixtures and residual radioactive materials) and deactivated. TPA Milestone M-89-02 dictates that all mixed waste and equipment be removed from B-Cell by 5/31/99. The following sections describe the major activities that remain for completion of the TPA milestone. These include: Size Reduce Tank 119 and Miscellaneous Equipment; Load and Ship Low-Level Waste; Remove and Size Reduce the 1B Rack; Collect Dispersible Material from Cell Floor; Remove and Size Reduce the 2A Rack; Size Reduce the 1A Rack; Load and Ship Mixed Waste to PUREX Tunnels; and Move Spent Fuel to A-Cell;

  13. Specific Btk inhibition suppresses B cell- and myeloid cell-mediated arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Di Paolo, Julie A; Huang, Tao; Balazs, Mercedesz; Barbosa, James; Barck, Kai H; Bravo, Brandon J; Carano, Richard A.D.; Darrow, James; Davies, Douglas R; DeForge, Laura E; Diehl, Lauri; Ferrando, Ronald; Gallion, Steven L; Giannetti, Anthony M; Gribling, Peter; Hurez, Vincent; Hymowitz, Sarah G; Jones, Randall; Kropf, Jeffrey E; Lee, Wyne P; Maciejewski, Patricia M; Mitchell, Scott A; Rong, Hong; Staker, Bart L; Whitney, J Andrew; Yeh, Sherry; Young, Wendy B; Yu, Christine; Zhang, Juan; Reif, Karin; Currie, Kevin S [CGI; (Emerald); (Genentech)

    2011-08-29

    Bruton's tyrosine kinase (Btk) is a therapeutic target for rheumatoid arthritis, but the cellular and molecular mechanisms by which Btk mediates inflammation are poorly understood. Here we describe the discovery of CGI1746, a small-molecule Btk inhibitor chemotype with a new binding mode that stabilizes an inactive nonphosphorylated enzyme conformation. CGI1746 has exquisite selectivity for Btk and inhibits both auto- and transphosphorylation steps necessary for enzyme activation. Using CGI1746, we demonstrate that Btk regulates inflammatory arthritis by two distinct mechanisms. CGI1746 blocks B cell receptor–dependent B cell proliferation and in prophylactic regimens reduces autoantibody levels in collagen-induced arthritis. In macrophages, Btk inhibition abolishes FcγRIII-induced TNFα, IL-1β and IL-6 production. Accordingly, in myeloid- and FcγR-dependent autoantibody-induced arthritis, CGI1746 decreases cytokine levels within joints and ameliorates disease. These results provide new understanding of the function of Btk in both B cell– or myeloid cell–driven disease processes and provide a compelling rationale for targeting Btk in rheumatoid arthritis.

  14. Pathological Role of Tonsillar B Cells in IgA Nephropathy

    Directory of Open Access Journals (Sweden)

    Yusuke Suzuki

    2011-01-01

    Full Text Available Although impaired immune regulation along the mucosa-bone marrow axis has been postulated to play an important role, the pathogenesis of IgA nephropathy (IgAN is unknown; thus, no disease-specific therapy for this disease exists. The therapeutic efficacy of tonsillectomy or tonsillectomy in combination with steroid pulse therapy for IgAN has been discussed. Although randomized control trials for these therapies are ongoing in Japan, the scientific rationale for these therapies remains obscure. It is now widely accepted that abnormally glycosylated IgA1 and its related immune complex (IC are probably key molecules for the pathogenesis, and are thus considered possible noninvasive biomarkers for this disease. Emerging evidence indicates that B cells in mucosal infections, particularly in tonsillitis, may produce the nephritogenic IgA. In this paper, we briefly summarize characteristics of the nephritogenic IgA/IgA IC, responsible B cells, and underlying mechanisms. This clinical and experimental information may provide important clues for a therapeutic rationale.

  15. Assembly and Function of the Precursor B-Cell Receptor.

    Science.gov (United States)

    Übelhart, Rudolf; Werner, Markus; Jumaa, Hassan

    2016-01-01

    During early stages of development, precursor B lymphocytes express a characteristic type of antigen receptor known as the pre-B-cell receptor (pre-BCR). This receptor differs from conventional BCRs in that it possesses a germ line-encoded surrogate light chain (SLC), which is associated with the signal transduction machinery via heavy chain (HC) proteins that have been generated by productive rearrangement of the immunoglobulin HC genes. The pre-BCR marks a key step of B-cell commitment, as it activates the B-cell-specific signaling cascade and mediates the selection, expansion, and differentiation of cells expressing a productively rearranged HC protein. Another difference between the pre-BCR and conventional BCR might be the initial event that triggers receptor activation, as the pre-BCR is activated in the absence of external ligands, while conventional BCRs require antigen for activation. Nonetheless, the pre-BCR downstream signaling cascade is largely similar to that of the BCR suggesting that the characteristic LC of the pre-BCR mediates important receptor interactions thereby providing distinctive, germ line-encoded features to the pre-BCR. In fact, the SLC enables the pre-BCR to act as a surrogate autoreactive receptor. Here, we outline the structure and function of the pre-BCR and how the autonomous signaling capacity might be a direct consequence of pre-BCR assembly. In addition to its role in early B-cell development, we discuss how the ordered activation of downstream signaling cascades enables the pre-BCR to activate seemingly opposing cellular programs such as proliferation and differentiation. PMID:26415650

  16. Diffuse Large B Cell Lymphoma of the Breast

    OpenAIRE

    Feryal Karaca; Vehbi Ercolak; Cigdem Usul Afsar; Meral Gunaldi

    2015-01-01

    Primary breast lymphoma is rarely encountered in Non-Hodgkin Lymphomas. However, if early diagnosis is made, and treatment is started immediately in patients with low grade and stage, patient survival is increased. 39-year old female patient applied us due to a palpable mass. She was diagnosed with the Non-Hodgkin Lymphoma Diffuse Large B Cell Lymphoma after the investigations. Curative external radiotherapy was applied after 6 courses of CHOP-R chemotherapy to the patient with Stage-IIE favo...

  17. Regulation of B cell function by plasmacytoid dendritic cells

    OpenAIRE

    Gujer, Cornelia

    2011-01-01

    Dendritic cells (DCs) are early sentinels of pathogen exposure and central in the initiation and orchestration of adaptive immune responses. Apart from the prominent role of DCs in the activation of T cells, DCs have been shown to influence humoral B cell mediated responses. DCs are therefore important cells for regulating immune responses to vaccines. Many of the vaccines under development today are against pathogens such as Mycobacterium tuberculosis and HIV-1 that likely r...

  18. Sources of DNA for detecting B cell monoclonality using PCR.

    OpenAIRE

    Diss, T. C.; Pan, L.; Peng, H; Wotherspoon, A C; Isaacson, P G

    1994-01-01

    AIMS--To evaluate the polymerase chain reaction (PCR) demonstration of clonal immunoglobulin heavy chain gene rearrangements using routinely prepared, unstained, and stained formalin fixed, paraffin wax embedded tissue samples. METHODS--Extracts from (a) fresh frozen tissue samples, (b) unstained, and (c) haematoxylin and eosin stained formalin fixed, paraffin wax embedded 5 microns tissue sections from 42 cases of low grade B cell lymphoma, all shown to be monoclonal by Southern blot analysi...

  19. Refining the Neuberger Model: uracil processing by activated B cells

    OpenAIRE

    Maul, Robert W.; Gearhart, Patricia J.

    2014-01-01

    During the immune response, B cells undergo a programmed mutagenic cascade to promote increased affinity and expanded antibody function. The two processes, somatic hypermutation (SHM) and class switch recombination (CSR), are initiated by the protein activation-induced deaminase (AID), which converts cytosine to uracil in the immunoglobulin loci. The presence of uracil in DNA promotes DNA mutagenesis though a subset of DNA repair proteins. Two distinct mechanisms have been proposed to control...

  20. Antigen Processing by Autoreactive B Cells Promotes Determinant Spreading

    Institute of Scientific and Technical Information of China (English)

    Yang D.Dai; George Carayanniotis; Eli Sercarz

    2005-01-01

    Acute primary immune responses tend to focus on few immunodominant determinants using a very limited number of T cell clones for expansion, whereas chronic inflammatory responses generally recruit a large number of different T cell clones to attack a broader range of determinants of the invading pathogens or the inflamed tissues.In T cell-mediated organ-specific autoimmune disease, a transition from the acute to the chronic phase contributes to pathogenesis, and the broadening process is called determinant spreading. The cellular components catalyzing the spreading reaction are not identified. It has been suggested that autoreactive B cells may play a central role in diversifying autoreactive T cell responses, possibly through affecting antigen processing and presentation. The clonal identity and diversity of the B cells and antibodies seem critical in regulating T cell activity and subsequent tissue damage or repair. Here, we use two autoimmune animal models, experimental autoimmune thyroiditis (EAT)and type 1 diabetes (T1D), to discuss how autoreactive B cells or antibodies alter the processing and presentation of autoantigens to regulate specific T cell response.

  1. Small B cell lymphocytic lymphoma presenting as obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Chang Weng-Cheng

    2004-07-01

    Full Text Available Abstract Background Most lymphomas that involve the tonsil are large B cell lymphomas. Large B-cell lymphoma is a high grade malignancy which progresses rapidly. Tonsillar lymphoma usually presents as either a unilaterally enlarged palatine tonsil or as an ulcerative and fungating lesion over the tonsillar area. Small lymphocytic lymphomas (SLL of the Waldeyer's ring are uncommon. Case presentation We report a 41-year-old male who presented with a ten-year history of snoring. Physical examination revealed smooth bilateral symmetrically enlarged tonsils without abnormal surface change or cervical lymphadenopathy. Palatal redundancy and a narrowed oropharyngeal airway were also noted. The respiratory disturbance index (RDI was 66 per hour, and severe obstruction sleep apnea (OSA was suspected. No B symptoms, sore throat, odynophagia or dysphagia was found. We performed uvulopalatopharyngoplasty (UPPP and pathological examination revealed incidental small B-cell lymphocytic lymphoma (SLL. Conclusion It is uncommon for lymphoma to initially present as OSA. SLL is an indolent malignancy and is not easy to detect in the early stage. We conclude that SLL may be a contributing factor of OSA in the present case.

  2. The acquisition of cytokine responsiveness by murine B cells

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1994-01-01

    The mechanism whereby small resting (high buoyant density) murine B cells are induced to express interleukin-2 receptors (IL-2R) and to respond to IL-2 was addressed by staining with anti-IL-2R alpha and -IL-2R beta monoclonal antibodies (mAb), and using receptor-specific cDNA probes. Resting B...... staining and mRNA were induced by the combination of LPS plus IL-5. LPS+IL-5-treated B cells responded to IL-2 by Ig secretion. This indicates that B cells regulate their responsiveness to IL-2 similarly to T cells, via the combined level of expression of IL-2R beta and IL-2R alpha. The synergy between IL...... cells expressed undetectable levels of both IL-2R alpha and beta chains on their surface and did not respond to IL-2, even at supra-physiological concentrations. Sepharose-coupled, but not streptavidin-cross-linked, plastic-adsorbed or soluble, anti-mu up-regulated the expression of IL-2R alpha and beta...

  3. Ongoing Immunoglobulin Class Switch DNA Recombination in Lupus B Cells: Analysis of Switch Regulatory Regions

    OpenAIRE

    Liu, Shiquan; Cerutti, Andrea; Casali, Paolo; CROW, MARY K.

    2004-01-01

    Inflammation and tissue damage in systemic lupus erythematosus (SLE) are mediated by class-switched autoantibodies reactive with nucleic acids, nucleic acid-binding proteins, phospholipids and other self-antigens. While some healthy individuals produce IgM antibodies with specificities similar to those of lupus patients, immunoglobulin class switching to mature downstream isotypes appears to be required for the generation of pathogenic autoantibodies. To characterize the cellular and molecula...

  4. Heme oxygenase-1 prevents smoke induced B-cell infiltrates : a role for regulatory T cells?

    NARCIS (Netherlands)

    Brandsma, Corry-Anke; Hylkema, Machteld N.; van der Strate, Barry W. A.; Slebos, Dirk-Jan; Luinge, Marjan A.; Geerlings, Marie; Timens, Wim; Postma, Dirkje S.; Kerstjens, Huib A. M.

    2008-01-01

    Background: Smoking is the most important cause for the development of COPD. Since not all smokers develop COPD, it is obvious that other factors must be involved in disease development. We hypothesize that heme oxygenase-1 (HO-1), a protective enzyme against oxidative stress and inflammation, is in

  5. The role of regulatory T cells in the control of B cell mediated immune responses

    OpenAIRE

    Wollenberg, Ivonne

    2011-01-01

    Tese de doutoramento, Ciências Biomédicas (Imunologia), Universidade de Lisboa, Faculdade de Medicina, 2011 This thesis reports research on the regulation of immune responses leading to a humoral immune reaction. This type of immune phenomena is based on B-T cell interactions. The first part of the thesis is devoted to study the effect of OX40-ligand blockade in preventing allergic airways disease in mice. Allergic airways disease is a Th2-dependent pathology associated with production of ...

  6. 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; Johansen, P; Bøgsted, Martin; Nyegaard, Mette; Bukh, Anne; Fogd, Kirsten; Orfao, Alberto; Dybkær, Karen

    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, 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...

  7. Composite diffuse large B-cell lymphoma and follicular B-cell lymphoma - case report and review of literature.

    Science.gov (United States)

    Turbatu, Andrei; Stoian, Marilena; Brezean, Iulian; Stoica, Victor Constantin Ion; Colita, Andrei; Dobrea, Camelia; State, Nicoleta; Ionescu, Cosmin; Ivanescu, Ana-Maria; Oprea, Madalina; Ghimici, Cecilia; Lupu, Anca Roxana

    2014-06-01

    Composite lymphoma refers to the co-occurrence of two or more morphologically and immunophenotypically separate lymphomas in the same topographic site at the time of clinical presentation. It is an infrequent type of lymphoid neoplasm, present in lymphoid tissue and may be due to the existence of two genetically related neoplasms such as transformation of a single lymphoma into another more aggressive lymphoma or be due to the presence of two clonally unrelated lymphomas. This paper is presenting a case of diffuse non-Hodgkin large B-cell lymphoma with areas of low grade and high grade follicular non-Hodgkin B-cell lymphoma in a retroperitoneal lymph node and spleen of an 62 year old woman. Histopathological examination and immunohistochemistry features proved the diagnosis of composite lymphoma. PMID:25705280

  8. Composite Diffuse Large B-Cell Lymphoma and Follicular B-Cell Lymphoma – Case Report and Review of Literature

    Science.gov (United States)

    TURBATU, Andrei; STOIAN, Marilena; BREZEAN, Iulian; STOICA, Victor Constantin Ion; COLITA, Andrei; DOBREA, Camelia; STATE, Nicoleta; IONESCU, Cosmin; IVANESCU, Ana-Maria; OPREA, Madalina; GHIMICI, Cecilia; LUPU, Anca Roxana

    2014-01-01

    Composite lymphoma refers to the co-occurrence of two or more morphologically and immunophenotypically separate lymphomas in the same topographic site at the time of clinical presentation. It is an infrequent type of lymphoid neoplasm, present in lymphoid tissue and may be due to the existence of two genetically related neoplasms such as transformation of a single lymphoma into another more aggressive lymphoma or be due to the presence of two clonally unrelated lymphomas. This paper is presenting a case of diffuse non-Hodgkin large B-cell lymphoma with areas of low grade and high grade follicular non-Hodgkin B-cell lymphoma in a retroperitoneal lymph node and spleen of an 62 year old woman. Histopathological examination and immunohistochemistry features proved the diagnosis of composite lymphoma. PMID:25705280

  9. Epstein-Barr nuclear antigen 1 induces expression of the cellular microRNA hsa-miR-127 and impairing B-cell differentiation in EBV-infected memory B cells. New insights into the pathogenesis of Burkitt lymphoma

    International Nuclear Information System (INIS)

    Epstein-Barr Virus (EBV) is a γ-herpesvirus that infects >90% of the human population. Although EBV persists in its latent form in healthy carriers, the virus is also associated with several human cancers. EBV is strongly associated with Burkitt lymphoma (BL), even though there is still no satisfactory explanation of how EBV participates in BL pathogenesis. However, new insights into the interplay between viruses and microRNAs (miRNAs) have recently been proposed. In particular, it has been shown that B-cell differentiation in EBV-positive BL is impaired at the post-transcriptional level by altered expression of hsa-miR-127. Here, we show that the overexpression of hsa-miR-127 is due to the presence of the EBV-encoded nuclear antigen 1 (EBNA1) and give evidence of a novel mechanism of direct regulation of the human miRNA by this viral product. Finally, we show that the combinatorial expression of EBNA1 and hsa-miR-127 affects the expression of master B-cell regulators in human memory B cells, confirming the scenario previously observed in EBV-positive BL primary tumors and cell lines. A good understanding of these mechanisms will help to clarify the complex regulatory networks between host and pathogen, and favor the design of more specific treatments for EBV-associated malignancies

  10. Cutting Edge: IL-4, IL-21, and IFN-γ Interact To Govern T-bet and CD11c Expression in TLR-Activated B Cells.

    Science.gov (United States)

    Naradikian, Martin S; Myles, Arpita; Beiting, Daniel P; Roberts, Kenneth J; Dawson, Lucas; Herati, Ramin Sedaghat; Bengsch, Bertram; Linderman, Susanne L; Stelekati, Erietta; Spolski, Rosanne; Wherry, E John; Hunter, Christopher; Hensley, Scott E; Leonard, Warren J; Cancro, Michael P

    2016-08-15

    T-bet and CD11c expression in B cells is linked with IgG2c isotype switching, virus-specific immune responses, and humoral autoimmunity. However, the activation requisites and regulatory cues governing T-bet and CD11c expression in B cells remain poorly defined. In this article, we reveal a relationship among TLR engagement, IL-4, IL-21, and IFN-γ that regulates T-bet expression in B cells. We find that IL-21 or IFN-γ directly promote T-bet expression in the context of TLR engagement. Further, IL-4 antagonizes T-bet induction. Finally, IL-21, but not IFN-γ, promotes CD11c expression independent of T-bet. Using influenza virus and Heligmosomoides polygyrus infections, we show that these interactions function in vivo to determine whether T-bet(+) and CD11c(+) B cells are formed. These findings suggest that T-bet(+) B cells seen in health and disease share the common initiating features of TLR-driven activation within this circumscribed cytokine milieu. PMID:27430719

  11. RAG-mediated DNA double-strand breaks activate a cell type-specific checkpoint to inhibit pre-B cell receptor signals.

    Science.gov (United States)

    Bednarski, Jeffrey J; Pandey, Ruchi; Schulte, Emily; White, Lynn S; Chen, Bo-Ruei; Sandoval, Gabriel J; Kohyama, Masako; Haldar, Malay; Nickless, Andrew; Trott, Amanda; Cheng, Genhong; Murphy, Kenneth M; Bassing, Craig H; Payton, Jacqueline E; Sleckman, Barry P

    2016-02-01

    DNA double-strand breaks (DSBs) activate a canonical DNA damage response, including highly conserved cell cycle checkpoint pathways that prevent cells with DSBs from progressing through the cell cycle. In developing B cells, pre-B cell receptor (pre-BCR) signals initiate immunoglobulin light (Igl) chain gene assembly, leading to RAG-mediated DNA DSBs. The pre-BCR also promotes cell cycle entry, which could cause aberrant DSB repair and genome instability in pre-B cells. Here, we show that RAG DSBs inhibit pre-BCR signals through the ATM- and NF-κB2-dependent induction of SPIC, a hematopoietic-specific transcriptional repressor. SPIC inhibits expression of the SYK tyrosine kinase and BLNK adaptor, resulting in suppression of pre-BCR signaling. This regulatory circuit prevents the pre-BCR from inducing additional Igl chain gene rearrangements and driving pre-B cells with RAG DSBs into cycle. We propose that pre-B cells toggle between pre-BCR signals and a RAG DSB-dependent checkpoint to maintain genome stability while iteratively assembling Igl chain genes. PMID:26834154

  12. Murine gammaherpesvirus M2 protein induction of IRF4 via the NFAT pathway leads to IL-10 expression in B cells.

    Directory of Open Access Journals (Sweden)

    Udaya S Rangaswamy

    2014-01-01

    Full Text Available Reactivation of the gammaherpesviruses Epstein-Barr virus (EBV, Kaposi's sarcoma-associated herpesvirus (KSHV and murine gammaherpesvirus 68 (MHV68 from latently infected B cells has been linked to plasma cell differentiation. We have previously shown that the MHV68 M2 protein is important for virus reactivation from B cells and, when expressed alone in primary murine B cells, can drive B cell differentiation towards a pre-plasma cell phenotype. In addition, expression of M2 in primary murine B cells leads to secretion of high levels of IL-10 along with enhanced proliferation and survival. Furthermore, the absence of M2 in vivo leads to a defect in the appearance of MHV68 infected plasma cells in the spleen at the peak of MHV68 latency. Here, employing an inducible B cell expression system, we have determined that M2 activates the NFAT pathway in a Src kinase-dependent manner--leading to induction of the plasma cell-associated transcription factor, Interferon Regulatory Factor-4 (IRF4. Furthermore, we show that expression of IRF4 alone in a B cell line up-regulates IL-10 expression in culture supernatants, revealing a novel role for IRF4 in B cell induced IL-10. Consistent with the latter observation, we show that IRF4 can regulate the IL-10 promoter in B cells. In primary murine B cells, addition of cyclosporine (CsA resulted in a significant decrease in M2-induced IL-10 levels as well as IRF4 expression, emphasizing the importance of the NFAT pathway in M2- -mediated induction of IL-10. Together, these studies argue in favor of a model wherein M2 activation of the NFAT pathway initiates events leading to increased levels of IRF4--a key player in plasma cell differentiation--which in turn triggers IL-10 expression. In the context of previous findings, the data presented here provides insights into how M2 facilitates plasma cell differentiation and subsequent virus reactivation.

  13. Characterization of xenoantiserum produced against B cell acute lymphoblastic leukemia cell line

    Directory of Open Access Journals (Sweden)

    Akagi,Tadaatsu

    1982-10-01

    Full Text Available Antiserum was produced in white rabbit by intravenously injecting living cells of a B cell acute lymphoblastic leukemia (ALL line (BALL-1. The reactivity of the antiserum against various lymphoid cell lines was examined by membrane immunofluorescence after appropriate absorption. Serum absorbed with non-T, non-B (NALL-1 and T-ALL (TALL-1 cells recognized B cell antigens distinct from Ia-like antigens on both normal and neoplastic B cells. After further absorption with tonsillar cells or normal B cell line (KO-HL-3, it reacted only with BALL-1 cells and did not react with other leukemia/lymphoma and normal B cell lines. The serum absorbed with tonsillar cells reacted only with BALL-1 and some B cell lines. Thus we were able to obtain antisera with specificity to B cell antigen, B-ALL antigen, and B cell line antigen.

  14. B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma: Report of a case in the oral cavity

    Directory of Open Access Journals (Sweden)

    Jumana M Jaradat

    2013-01-01

    Full Text Available B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (DLBCL/BL is a new category of B-cell lymphoma according to the 4 th edition of the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008. The following report presents a case of this rare, newly described entity on the palate of a 59 year-old male.

  15. Identification of Functional Human Splenic Memory B Cells by Expression of CD148 and CD27

    OpenAIRE

    Tangye, Stuart G.; Liu, Yong-Jun; Aversa, Gregorio; Phillips, Joseph H.; Vries, Jan E. de

    1998-01-01

    Memory B cells isolated from human tonsils are characterized by an activated cell surface phenotype, localization to mucosal epithelium, expression of somatically mutated immunoglobulin (Ig) variable (V) region genes, and a preferential differentiation into plasma cells in vitro. In spleens of both humans and rodents, a subset of memory B cells is believed to reside in the marginal zone of the white pulp. Similar to tonsil-derived memory B cells, splenic marginal zone B cells can be distingui...

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

    OpenAIRE

    Traitanon, Opas; Mathew, James M.; La Monica, Giovanna; Xu, Luting; Mas, Valeria; Gallon, Lorenzo

    2015-01-01

    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 monit...

  17. Aggressive B-cell lymphomas: how many categories do we need?

    OpenAIRE

    Said, Jonathan W.

    2012-01-01

    Aggressive B-cell lymphomas are diverse group of neoplasms that arise at different stages of B-cell development and by various mechanisms of neoplastic transformation. The aggressive B-cell lymphomas include many types, subtypes and variants of diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), mantle cell lymphoma and its blastoid variant, and B lymphoblastic lymphoma. Differences in histology, cytogenetic and molecular abnormalities, as well as the relationship with the tumor mic...

  18. Targeting Bruton's tyrosine kinase signaling as an emerging therapeutic agent of B-cell malignancies

    OpenAIRE

    Xia, Bing; QU, FULIAN; Yuan, Tian; Zhang, Yizhuo

    2015-01-01

    It is becoming increasingly evident that B-cell receptor (BCR) signaling is central to the development and function of B cells. BCR signaling has emerged as a pivotal pathway and a key driver of numerous B-cell lymphomas. Disruption of BCR signaling can be lethal to malignant B cells. Recently, kinase inhibitors that target BCR signaling have induced notable clinical responses. These inhibitors include spleen tyrosine kinase, mammalian target of rapamycin, phosphoinositide 3′-kinase and Bruto...

  19. Diffuse large B-cell lymphoma of the oral cavity

    International Nuclear Information System (INIS)

    The authors report a case of diffuse large B-cell lymphoma (DLBL) of the oral cavity. The patient was a 73-year-old white man who first presented at the Division of Stomatology with a large nodular mass in the hard palate and a nodular lesion in the upper lip, which were diagnosed as DLBL. The patient was treated with eight cycles of CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone), but the disease recurred 22 months after the end of the therapy. Both primary sites hard palate and upper lip were involved again and the patient was resubmitted to chemotherapy. (author)

  20. Hepatitis C virus - associated B cell non-Hodgkin's lymphoma

    Science.gov (United States)

    Mihăilă, Romeo-Gabriel

    2016-01-01

    The hepatitis C virus (HCV) infected patients are prone to develop bone marrow or various tissue infiltrates with monoclonal B cells, monoclonal B lymphocytosis or different types of B cell non-Hodgkin’s lymphoma (BCNHL), of which the most common are splenic marginal zone BCNHL, diffuse large BCNHL and follicular lymphoma. The association between chronic HCV infection and non Hodgkin’s lymphoma has been observed especially in areas with high prevalence of this viral infection. Outside the limitations of some studies that have been conducted, there are also geographic, environmental, and genetic factors that contribute to the epidemiological differences. Various microenvironmental signals, such as cytokines, viral antigenic external stimulation of lymphocyte receptors by HCV antigens, and intercellular interactions contribute to B cell proliferation. HCV lymphotropism and chronic antigenic stimulation are involved in B-lymphocyte expansion, as mixted cryoglobulinemia or monoclonal gammopathy of undetermined significance, which can progress to BCNHL. HCV replication in B lymphocytes has oncogenic effect mediated by intracellular HCV proteins. It is also involved in an important induction of reactive oxygen species that can lead to permanent B lymphocyte damage, as DNA mutations, after binding to surface B-cell receptors. Post-transplant lymphoproliferative disorder could appear and it has a multiclonal potentiality that may develop into different types of lymphomas. The hematopoietic stem cell transplant made for lymphoma in HCV-infected patients can increase the risk of earlier progression to liver fibrosis and cirrhosis. HCV infected patients with indolent BCNHL who receive antiviral therapy can be potentially cured. Viral clearance was related to lymphoma response, fact that highlights the probable involvement of HCV in lymphomagenesis. Direct acting antiviral drugs could be a solution for the patients who did not tolerate or respond to interferon, as they

  1. B cell stimulatory factor 1 (BSF-1) prepares resting B cells to enter S phase in response to anti-IgM and lipopolysaccharide

    OpenAIRE

    1986-01-01

    BSF-1 prepares resting BALB/c, DBA/2, and BDF1 B cells to enter S phase more promptly in response to subsequent culture with anti-IgM-based stimulants. It prepares DBA/2 and BDF1 B cells to respond to LPS, but its preparative effect for LPS responses of BALB/c B cells is both inconstant and meager. Preparation mediated by BSF-1 requires extended contact of B cells with the stimulant for full effect. Half-maximal preparation requires approximately 12 h of contact, as judged by delayed addition...

  2. PAX5 promotes pre-B cell proliferation by regulating the expression of pre-B cell receptor and its downstream signaling.

    Science.gov (United States)

    Xue, Kai; Song, Jiazhe; Yang, Yan; Li, Zhi; Wu, Chunhua; Jin, Jinhua; Li, Wenzhe

    2016-05-01

    PAX5 is indispensable for the commitment of early lymphoid progenitors to the B cell lineage as well as for the development of B cells. Although previous studies have indicated that the Pax5-conditional-knockout mouse exhibited dedifferentiation of mature B cell and the development of aggressive lymphomas, the changes of Pax5 gene expressions in pre-B cells have not been analyzed. To understand the functional importance of Pax5 gene in the proliferation and survival of pre-B cells, we established a Pax5-knockdown model using 70Z/3 pre-B cell line. Pax5 knockdown 70Z/3 cells (70Z/3-KD cells) showed down-regulations of pre-BCR compounds such as CD19, BLNK, Id2 and λ5. The signaling via pre-BCRs was significantly diminished in the 70Z/3-KD cells, and this alteration was normalized by restored Pax5 gene expression. Loss of PAX5 reduced the growth rates in the 70Z/3-KD cells, compared to the mock cells. Meanwhile, the proliferation of pre-B cells was reduced by the knockdown of Pax5 gene. Moreover, further examinations showed that PAX5 was also activated in B cell acute lymphoblastic leukemia (B-ALL) as a cell proliferation enhancer. These findings suggested that pax5 is critically important for the proliferation and survival of pre-B cells. PMID:27016671

  3. R-ICE and Lenalidomide in Treating Patients With First-Relapse/Primary Refractory Diffuse Large B-Cell Lymphoma

    Science.gov (United States)

    2015-12-30

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

  4. Coordinate suppression of B cell lymphoma by PTEN and SHIP phosphatases

    DEFF Research Database (Denmark)

    Miletic, Ana V; Anzelon-Mills, Amy N; Mills, David M; Omori, Sidne A; Pedersen, Irene M; Shin, Dong-Mi; Ravetch, Jeffrey V; Bolland, Silvia; Morse, Herbert C; Rickert, Robert C

    2010-01-01

    , follicular or centroblastic lymphoma. bPTEN/SHIP(-/-) B cells exhibit enhanced survival and express more MCL1 and less Bim. These cells also express low amounts of p27(kip1) and high amounts of cyclin D3 and thus appear poised to undergo proliferative expansion. Unlike normal B cells, bPTEN/SHIP(-/-) B cells...

  5. B cells exposed to enterobacterial components suppress development of experimental colitis

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Larsen, Hjalte List; Kristensen, Nanna Ny; Poulsen, Steen Seier; Claesson, Mogens Helweg; Pedersen, Anders Elm

    2012-01-01

    development of colitis. Suppression was dependent on B cell-derived IL-10, as co-transfer of IL-10 knockout ebx-B cells failed to suppress colitis. Ebx-B cell-mediated suppression of colitis was associated with a decrease in interferon gamma (IFN-¿)-producing T(H) 1 cells and increased frequencies of Foxp3...

  6. File list: ALL.Bld.10.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.10.AllAg.Pro-B_cells mm9 All antigens Blood Pro-B cells SRX1553109,SRX15531...9,SRX1143902 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Bld.10.AllAg.Pro-B_cells.bed ...

  7. Modulation of B-cell receptor and microenvironment signaling by a guanine exchange factor in B-cell malignancies

    Institute of Scientific and Technical Information of China (English)

    Wei Liao; Sanjai Sharma

    2016-01-01

    Objective: Chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) cells over-express a guanine exchange factor (GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods: N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor (BCR) and chemokine signaling pathways were compared in the Rasgrf-1 over-expressing and a control transfected cell line. Results: Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions: This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.

  8. MicroRNA signatures in B-cell lymphomas

    International Nuclear Information System (INIS)

    Accurate lymphoma diagnosis, prognosis and therapy still require additional markers. We explore the potential relevance of microRNA (miRNA) expression in a large series that included all major B-cell non-Hodgkin lymphoma (NHL) types. The data generated were also used to identify miRNAs differentially expressed in Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) samples. A series of 147 NHL samples and 15 controls were hybridized on a human miRNA one-color platform containing probes for 470 human miRNAs. Each lymphoma type was compared against the entire set of NHLs. BL was also directly compared with DLBCL, and 43 preselected miRNAs were analyzed in a new series of routinely processed samples of 28 BLs and 43 DLBCLs using quantitative reverse transcription-polymerase chain reaction. A signature of 128 miRNAs enabled the characterization of lymphoma neoplasms, reflecting the lymphoma type, cell of origin and/or discrete oncogene alterations. Comparative analysis of BL and DLBCL yielded 19 differentially expressed miRNAs, which were confirmed in a second confirmation series of 71 paraffin-embedded samples. The set of differentially expressed miRNAs found here expands the range of potential diagnostic markers for lymphoma diagnosis, especially when differential diagnosis of BL and DLBCL is required

  9. 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.

  10. Dominant neurologic symptomatology in intravascular large B-cell lymphoma.

    Science.gov (United States)

    Kubisova, K; Martanovic, P; Sisovsky, V; Tomleinova, Z; Steno, A; Janega, P; Rychly, B; Babal, P

    2016-01-01

    Intravascular large B-cell lymphoma (IVLBCL) is a rare variant of extranodal large B-cell lymphoma and it is characterized by selective intravascular proliferation of malignant cells. Typical features of the disease include aggressive behavior, rapid and frequently fatal course. Clinical picture is non-specific and heterogeneous, depending on the affected organ. It is not uncommon that this unique type of lymphoma is diagnosed post mortem. Herein, we report two cases of IVLBCL with neurologic symptomatology. In our clinical study patient 1 was an 80-year-old male with mixed paraparesis of lower extremities and difficulties with sphincter control. Patient 2 (56-year-old male) had vision malfunction, mental status changes and defect in phatic and motor functions. In both cases definite diagnosis was established by histological examination of necroptic material. We propose to include IVLBCL in differential diagnostic considerations in patients presenting with gradually impairing neurological status and spinal cord damage of unknown etiology (Fig. 2, Ref. 9). PMID:27546361

  11. Quantifying evolutionary constraints on B-cell affinity maturation.

    Science.gov (United States)

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

    2015-09-01

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

  12. Mast cells, basophils and B cell connection network.

    Science.gov (United States)

    Merluzzi, Sonia; Betto, Elena; Ceccaroni, Alice Amaranta; Magris, Raffaella; Giunta, Marina; Mion, Francesca

    2015-01-01

    It has been proven that both resting and activated mast cells (MCs) and basophils are able to induce a significant increase in proliferation and survival of naïve and activated B cells, and their differentiation into antibody-producing cells. The immunological context in which this regulation occurs is of particular interest and the idea that these innate cells induce antibody class switching and production is increasingly gaining ground. This direct role of MCs and basophils in acquired immunity requires cell to cell contact as well as soluble factors and exosomes. Here, we review our current understanding of the interaction between B cells and MCs or basophils as well as the evidence supporting B lymphocyte-MC/basophil crosstalk in pathological settings. Furthermore, we underline the obscure aspects of this interaction that could serve as important starting points for future research in the field of MC and basophil biology in the peculiar context of the connection between innate and adaptive immunity. PMID:24671125

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

    Science.gov (United States)

    Troussard, Xavier; Cornet, Édouard

    2015-01-01

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

  14. CD137 is induced by the CD40 signal on chronic lymphocytic leukemia B cells and transduces the survival signal via NF-κB activation.

    Directory of Open Access Journals (Sweden)

    Yukana Nakaima

    Full Text Available CD137 is a member of the tumor necrosis factor receptor family that is expressed on activated T cells. This molecule provides a co-stimulatory signal that enhances the survival, and differentiation of cells, and has a crucial role in the development of CD8 cytotoxic T cells and anti-tumor immunity. Here we report that CD137 expression is also induced on normal or malignant human B cells by CD40 ligation by its ligand CD154. This CD137 induction was more prominent in chronic lymphocytic leukemia (CLL cells than in other types of B cells. CD137 stimulation on B cells by its ligand induced the nuclear translocation of p52 (a non-canonical NF-κB factor. In agreement with this finding, expression of the survival factor BCL-XL was upregulated. Consequently, the CD137 signal augmented the survival of CD154-stimulated CLL B cells in vitro. This unexpected induction of CD137 on B cells by CD40 signal may influence the clinical course of CLL.

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

    Directory of Open Access Journals (Sweden)

    Xavier Troussard

    2008-10-01

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

  16. All-or-none suppression of B cell terminal differentiation by environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qiang, E-mail: qzhang@thehamner.org [Institute for Chemical Safety Sciences, The Hamner Institutes for Health Sciences, RTP, NC 27709 (United States); Kline, Douglas E. [Department of Pharmacology and Toxicology and Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States); Bhattacharya, Sudin [Institute for Chemical Safety Sciences, The Hamner Institutes for Health Sciences, RTP, NC 27709 (United States); Crawford, Robert B. [Department of Pharmacology and Toxicology and Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States); Conolly, Rory B. [Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, RTP, NC 27711 (United States); Thomas, Russell S.; Andersen, Melvin E. [Institute for Chemical Safety Sciences, The Hamner Institutes for Health Sciences, RTP, NC 27709 (United States); Kaminski, Norbert E., E-mail: kamins11@msu.edu [Department of Pharmacology and Toxicology and Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States)

    2013-04-01

    Many environmental contaminants can disrupt the adaptive immune response. Exposure to the ubiquitous aryl hydrocarbon receptor (AhR) ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other agonists suppresses the antibody response. The underlying pathway mechanism by which TCDD alters B cell function is not well understood. The present study investigated the mechanism of AhR-mediated pathways and mode of suppression by which TCDD perturbs terminal differentiation of B cells to plasma cells and thereby impairs antibody production. An integrated approach combining computational pathway modeling and in vitro assays with primary mouse B cells activated by lipopolysaccharide was employed. We demonstrated that suppression of the IgM response by TCDD occurs in an all-or-none (binary) rather than graded mode: i.e., it reduces the number of IgM-secreting cells in a concentration-dependent manner without affecting the IgM content in individual plasma cells. The mathematical model of the gene regulatory circuit underpinning B cell differentiation revealed that two previously identified AhR-regulated pathways, inhibition of signaling protein AP-1 and activation of transcription factor Bach2, could account for the all-or-none mode of suppression. Both pathways disrupt the operation of a bistable-switch circuit that contains transcription factors Bcl6, Prdm1, Pax5, and Bach2 and regulates B cell fate. The model further predicted that by transcriptionally activating Bach2, TCDD might delay B cell differentiation and increase the likelihood of isotype switching, thereby altering the antibody repertoire. In conclusion, the present study revealed the mode and specific pathway mechanisms by which the environmental immunosuppressant TCDD suppresses B cell differentiation. - Highlights: ► TCDD suppresses B cell differentiation stimulated by LPS in an all-or-none mode. ► TCDD reduces the fraction of IgM-secreting cells, not the IgM level in those cells. ► A mathematical model

  17. Spectratyping analysis of the islet-reactive T cell repertoire in diabetic NOD Igμnull mice after polyclonal B cell reconstitution

    Directory of Open Access Journals (Sweden)

    Sercarz Eli E

    2011-07-01

    Full Text Available Abstract Background Non Obese Diabetic mice lacking B cells (NOD.Igμnull mice do not develop diabetes despite their susceptible background. Upon reconstitution of B cells using a chimera approach, animals start developing diabetes at 20 weeks of age. Methods We have used the spectratyping technique to follow the T cell receptor (TCR V beta repertoire of NOD.Igμnull mice following B cell reconstitution. This technique provides an unbiased approach to understand the kinetics of TCR expansion. We have also analyzed the TCR repertoire of reconstituted animals receiving cyclophosphamide treatment and following tissue transplants to identify common aggressive clonotypes. Results We found that B cell reconstitution of NOD.Igμnull mice induces a polyclonal TCR repertoire in the pancreas 10 weeks later, gradually diversifying to encompass most BV families. Interestingly, these clonotypic BV expansions are mainly confined to the pancreas and are absent from pancreatic lymph nodes or spleens. Cyclophosphamide-induced diabetes at 10 weeks post-B cell reconstitution reorganized the predominant TCR repertoires by removing potential regulatory clonotypes (BV1, BV8 and BV11 and increasing the frequency of others (BV4, BV5S2, BV9, BV16-20. These same clonotypes are more frequently present in neonatal pancreatic transplants under the kidney capsule of B-cell reconstituted diabetic NOD.Igμnull mice, suggesting their higher invasiveness. Phenotypic analysis of the pancreas-infiltrating lymphocytes during diabetes onset in B cell reconstituted animals show a predominance of CD19+ B cells with a B:T lymphocyte ratio of 4:1. In contrast, in other lymphoid organs (pancreatic lymph nodes and spleens analyzed by FACS, the B:T ratio was 1:1. Lymphocytes infiltrating the pancreas secrete large amounts of IL-6 and are of Th1 phenotype after CD3-CD28 stimulation in vitro. Conclusions Diabetes in NOD.Igμnull mice appears to be caused by a polyclonal repertoire of T cell

  18. All-or-none suppression of B cell terminal differentiation by environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin

    International Nuclear Information System (INIS)

    Many environmental contaminants can disrupt the adaptive immune response. Exposure to the ubiquitous aryl hydrocarbon receptor (AhR) ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other agonists suppresses the antibody response. The underlying pathway mechanism by which TCDD alters B cell function is not well understood. The present study investigated the mechanism of AhR-mediated pathways and mode of suppression by which TCDD perturbs terminal differentiation of B cells to plasma cells and thereby impairs antibody production. An integrated approach combining computational pathway modeling and in vitro assays with primary mouse B cells activated by lipopolysaccharide was employed. We demonstrated that suppression of the IgM response by TCDD occurs in an all-or-none (binary) rather than graded mode: i.e., it reduces the number of IgM-secreting cells in a concentration-dependent manner without affecting the IgM content in individual plasma cells. The mathematical model of the gene regulatory circuit underpinning B cell differentiation revealed that two previously identified AhR-regulated pathways, inhibition of signaling protein AP-1 and activation of transcription factor Bach2, could account for the all-or-none mode of suppression. Both pathways disrupt the operation of a bistable-switch circuit that contains transcription factors Bcl6, Prdm1, Pax5, and Bach2 and regulates B cell fate. The model further predicted that by transcriptionally activating Bach2, TCDD might delay B cell differentiation and increase the likelihood of isotype switching, thereby altering the antibody repertoire. In conclusion, the present study revealed the mode and specific pathway mechanisms by which the environmental immunosuppressant TCDD suppresses B cell differentiation. - Highlights: ► TCDD suppresses B cell differentiation stimulated by LPS in an all-or-none mode. ► TCDD reduces the fraction of IgM-secreting cells, not the IgM level in those cells. ► A mathematical model

  19. Invariant chain induces B cell maturation in a process that is independent of its chaperonic activity

    Science.gov (United States)

    Matza, Didi; Lantner, Frida; Bogoch, Yoel; Flaishon, Liat; Hershkoviz, Rami; Shachar, Idit

    2002-01-01

    Early stages of B cell development take place in the bone marrow, resulting in formation of immature B cells, which migrate to the spleen for their final differentiation into mature cells. This final maturation step is essential for B cells to become responsive to antigens and to participate in the immune response. Previously, we showed that the MHC class II chaperone, invariant chain (Ii), controls the differentiation of B cells from the immature to the mature stage. In this study, by generating transgenic mice expressing truncated Ii lacking its luminal domain, we could dissect the chaperonin activity of Ii from its role in B cell maturation. We demonstrate in vivo that Ii N-terminal domain is directly involved in the maturation of B cells and is sufficient to promote B cell differentiation. PMID:11867743

  20. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production

    Science.gov (United States)

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A.; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C.; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten; Westendorf, Astrid M.; Häussinger, Dieter; Lang, Florian; Dittmer, Ulf; Küppers, Ralf; Recher, Mike; Hardt, Cornelia; Scheffrahn, Inka; Beauchemin, Nicole; Göthert, Joachim R.; Singer, Bernhard B.; Lang, Philipp A.; Lang, Karl S.

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1−/− mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1−/− mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. PMID:25692415

  1. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production.

    Science.gov (United States)

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten; Westendorf, Astrid M; Häussinger, Dieter; Lang, Florian; Dittmer, Ulf; Küppers, Ralf; Recher, Mike; Hardt, Cornelia; Scheffrahn, Inka; Beauchemin, Nicole; Göthert, Joachim R; Singer, Bernhard B; Lang, Philipp A; Lang, Karl S

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1(-/-) mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1(-/-) mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. PMID:25692415

  2. Cutting Edge: Redox Signaling Hypersensitivity Distinguishes Human Germinal Center B Cells.

    Science.gov (United States)

    Polikowsky, Hannah G; Wogsland, Cara E; Diggins, Kirsten E; Huse, Kanutte; Irish, Jonathan M

    2015-08-15

    Differences in the quality of BCR signaling control key steps of B cell maturation and differentiation. Endogenously produced H2O2 is thought to fine tune the level of BCR signaling by reversibly inhibiting phosphatases. However, relatively little is known about how B cells at different stages sense and respond to such redox cues. In this study, we used phospho-specific flow cytometry and high-dimensional mass cytometry (CyTOF) to compare BCR signaling responses in mature human tonsillar B cells undergoing germinal center (GC) reactions. GC B cells, in contrast to mature naive B cells, memory B cells, and plasmablasts, were hypersensitive to a range of H2O2 concentrations and responded by phosphorylating SYK and other membrane-proximal BCR effectors in the absence of BCR engagement. These findings reveal that stage-specific redox responses distinguish human GC B cells. PMID:26157177

  3. 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

    Human B cells are able to secrete IL-10 after stimulation with mitogens, but their ability to produce IL-10 and regulate T-cell responses after stimulation with self-antigens is unclear. We co-cultured thyroglobulin-pulsed B cells from healthy donors with autologous T cells and observed production...... 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 0.13±0.15% of CD4(+) T cells (P=0.006) following TT-pulsing. Thyroglobulin-stimulated, IL-10-secreting B cells were enriched within CD5(+) and CD24(high) cells. While thyroglobulin-pulsed B cells induced only modest proliferation of CD4(+) T cells, B cells pulsed with TT induced vigorous...

  4. Intravascular Large B-Cell Lymphoma: A Difficult Diagnostic Challenge.

    Science.gov (United States)

    Khan, Maria S; McCubbin, Mark; Nand, Sucha

    2014-01-01

    Case Presentation. A 69-year-old Hispanic male, with a past history of diabetes and coronary disease, was admitted for fever, diarrhea, and confusion of 4 weeks duration. Physical examination showed a disoriented patient with multiple ecchymoses, possible ascites, and bilateral scrotal swelling. Hemoglobin was 6.7, prothrombin time (PT) 21.4 seconds with international normalized ratio 2.1, partial thromboplastin time (PTT) 55.6 seconds, fibrin split 10 µg/L, and lactate dehydrogenase (LDH) 1231 IU/L. Except for a positive DNA test for Epstein-Barr virus (EBV) infection, extensive diagnostic workup for infections, malignancy, or a neurological cause was negative. Mixing studies revealed a nonspecific inhibitor of PT and PTT but Factor VIII levels were normal. The patient was empirically treated with antibiotics but developed hypotension and died on day 27 of admission. At autopsy, patient was found to have intravascular diffuse large B-cell lymphoma involving skin, testes, lung, and muscles. The malignant cells were positive for CD20, CD791, Mum-1, and Pax-5 and negative for CD3, CD5, CD10, CD30, and Bcl-6. The malignant cells were 100% positive for Ki-67. Discussion. Intravascular large cell B-cell lymphoma (IVLBCL) is rare form of diffuse large B-cell lymphoma and tends to proliferate within small blood vessels, particularly capillaries and postcapillary venules. The cause of its affinity for vascular bed remains unknown. In many reports, IVLBCL was associated with HIV, HHV8, and EBV infections. The fact that our case showed evidence of EBV infection lends support to the association of this diagnosis to viral illness. The available literature on this subject is scant, and in many cases, the diagnosis was made only at autopsy. The typical presentation of this disorder is with B symptoms, progressive neurologic deficits, and skin findings. Bone marrow, spleen, and liver are involved in a minority of patients. Nearly all patients have elevated LDH, and about 65% are

  5. Switch-mediated activation and retargeting of CAR-T cells for B-cell malignancies.

    Science.gov (United States)

    Rodgers, David T; Mazagova, Magdalena; Hampton, Eric N; Cao, Yu; Ramadoss, Nitya S; Hardy, Ian R; Schulman, Andrew; Du, Juanjuan; Wang, Feng; Singer, Oded; Ma, Jennifer; Nunez, Vanessa; Shen, Jiayin; Woods, Ashley K; Wright, Timothy M; Schultz, Peter G; Kim, Chan Hyuk; Young, Travis S

    2016-01-26

    Chimeric antigen receptor T (CAR-T) cell therapy has produced impressive results in clinical trials for B-cell malignancies. However, safety concerns related to the inability to control CAR-T cells once infused into the patient remain a significant challenge. Here we report the engineering of recombinant antibody-based bifunctional switches that consist of a tumor antigen-specific Fab molecule engrafted with a peptide neo-epitope, which is bound exclusively by a peptide-specific switchable CAR-T cell (sCAR-T). The switch redirects the activity of the bio-orthogonal sCAR-T cells through the selective formation of immunological synapses, in which the sCAR-T cell, switch, and target cell interact in a structurally defined and temporally controlled manner. Optimized switches specific for CD19 controlled the activity, tissue-homing, cytokine release, and phenotype of sCAR-T cells in a dose-titratable manner in a Nalm-6 xenograft rodent model of B-cell leukemia. The sCAR-T-cell dosing regimen could be tuned to provide efficacy comparable to the corresponding conventional CART-19, but with lower cytokine levels, thereby offering a method of mitigating cytokine release syndrome in clinical translation. Furthermore, we demonstrate that this methodology is readily adaptable to targeting CD20 on cancer cells using the same sCAR-T cell, suggesting that this approach may be broadly applicable to heterogeneous and resistant tumor populations, as well as other liquid and solid tumor antigens. PMID:26759369

  6. Identification of a B cell-dependent subpopulation of multiple sclerosis by measurements of brain-reactive B cells in the blood.

    Science.gov (United States)

    Kuerten, Stefanie; Pommerschein, Giovanna; Barth, Stefanie K; Hohmann, Christopher; Milles, Bianca; Sammer, Fabian W; Duffy, Cathrina E; Wunsch, Marie; Rovituso, Damiano M; Schroeter, Michael; Addicks, Klaus; Kaiser, Claudia C; Lehmann, Paul V

    2014-01-01

    B cells are increasingly coming into play in the pathogenesis of multiple sclerosis (MS). Here, we screened peripheral blood mononuclear cells (PBMC) from patients with clinically isolated syndrome (CIS), MS, other non-inflammatory neurological, inflammatory neurological or autoimmune diseases, and healthy donors for their B cell reactivity to CNS antigen using the enzyme-linked immunospot technique (ELISPOT) after 96 h of polyclonal stimulation. Our data show that nine of 15 patients with CIS (60.0%) and 53 of 67 patients with definite MS (79.1%) displayed CNS-reactive B cells, compared to none of the control donors. The presence of CNS-reactive B cells in the blood of the majority of patients with MS or at risk to develop MS along with their absence in control subjects suggests that they might be indicative of a B cell-dependent subpopulation of the disease. PMID:24607792

  7. Diffuse Large B Cell Lymphoma of the Breast

    Directory of Open Access Journals (Sweden)

    Feryal Karaca

    2015-03-01

    Full Text Available Primary breast lymphoma is rarely encountered in Non-Hodgkin Lymphomas. However, if early diagnosis is made, and treatment is started immediately in patients with low grade and stage, patient survival is increased. 39-year old female patient applied us due to a palpable mass. She was diagnosed with the Non-Hodgkin Lymphoma Diffuse Large B Cell Lymphoma after the investigations. Curative external radiotherapy was applied after 6 courses of CHOP-R chemotherapy to the patient with Stage-IIE favorable, and B symptoms. After 48-month follow up, patient follow up is being continued without any progression, or recurrence or metastasis. [Cukurova Med J 2015; 40(1.000: 151-157

  8. B Cell Depletion: Rituximab in Glomerular Disease and Transplantation

    Directory of Open Access Journals (Sweden)

    S. Marinaki

    2013-12-01

    Full Text Available B cells play a central role in the pathogenesis of many autoimmune diseases. Selective targeting can be achieved with the use of the monoclonal antibody rituximab. In addition to being a drug for non-Hodgkin's lymphoma, rituximab is also an FDA-approved treatment for refractory rheumatoid arthritis and, since recently, ANCA vasculitis. It has shown efficacy in many autoimmune diseases. This review will discuss current evidence and the rationale of the use of rituximab in glomerular diseases, including randomized controlled trials. The focus will be on the use of rituximab in idiopathic membranous nephropathy, systemic lupus erythematosus and ANCA-associated vasculitis. The emerging role of rituximab in renal transplantation, where it seems to be important for the desensitization protocols for highly sensitized patients as well as for the preconditioning of ABO-incompatible recipients and the treatment of antibody-mediated rejection, will also be addressed.

  9. Regulation of the germinal center gene program by interferon (IFN) regulatory factor 8/IFN consensus sequence-binding protein

    OpenAIRE

    Lee, Chang Hoon; Melchers, Mark; Wang, Hongsheng; Torrey, Ted A.; Slota, Rebecca; Qi, Chen-Feng; Kim, Ji Young; Lugar, Patricia; Kong, Hee Jeong; Farrington, Lila; van der Zouwen, Boris; ZHOU, JEFF X.; Lougaris, Vassilios; Lipsky, Peter E.; Grammer, Amrie C.

    2006-01-01

    Interferon (IFN) consensus sequence-binding protein/IFN regulatory factor 8 (IRF8) is a transcription factor that regulates the differentiation and function of macrophages, granulocytes, and dendritic cells through activation or repression of target genes. Although IRF8 is also expressed in lymphocytes, its roles in B cell and T cell maturation or function are ill defined, and few transcriptional targets are known. Gene expression profiling of human tonsillar B cells and mouse B cell lymphoma...

  10. The Functional Response of B Cells to Antigenic Stimulation: A Preliminary Report of Latent Tuberculosis

    Science.gov (United States)

    du Plessis, Willem J.; Kleynhans, Léanie; du Plessis, Nelita; Stanley, Kim; Malherbe, Stephanus T.; Maasdorp, Elizna; Ronacher, Katharina; Chegou, Novel N.; Walzl, Gerhard; Loxton, Andre G.

    2016-01-01

    Mycobacterium tuberculosis (M.tb) remains a successful pathogen, causing tuberculosis disease numbers to constantly increase. Although great progress has been made in delineating the disease, the host-pathogen interaction is incompletely described. B cells have shown to function as both effectors and regulators of immunity via non-humoral methods in both innate and adaptive immune settings. Here we assessed specific B cell functional interaction following stimulation with a broad range of antigens within the LTBI milieu. Our results indicate that B cells readily produce pro- and anti-inflammatory cytokines (including IL-1β, IL-10, IL-17, IL-21 and TNF-α) in response to stimulation. TLR4 and TLR9 based stimulations achieved the greatest secreted cytokine-production response and BCG stimulation displayed a clear preference for inducing IL-1β production. We also show that the cytokines produced by B cells are implicated strongly in cell-mediated communication and that plasma (memory) B cells (CD19+CD27+CD138+) is the subset with the greatest contribution to cytokine production. Collectively our data provides insight into B cell responses, where they are implicated in and quantifies responses from specific B cell phenotypes. These findings warrant further functional B cell research with a focus on specific B cell phenotypes under conditions of active TB disease to further our knowledge about the contribution of various cell subsets which could have implications for future vaccine development or refined B cell orientated treatment in the health setting. PMID:27050308

  11. Induction of polyclonal B cell activation and differentiation by the AIDS retrovirus (HTLV-III/LAV)

    International Nuclear Information System (INIS)

    The immune systems of individuals infected with HTLV-III/LAV are characterized by a profound defect in cellular immunity together with paradoxical polyclonal B cell activation. The present study examined the direct effects of HTLV-III/LAV on B lymphocytes. Peripheral blood B cells from healthy donors were incubated with a variety of HTLV-III/LAV isolates for 1 h and 3H-thymidine incorporation was measured at multiple time points. Responses ranged from 9000-28,000 cpm and peaked on day 4. This B cell activation was not enhanced by the addition of interleukin-2 to culture, was not synergistic with Staphylococcus aureus Cowan I, was not modulated by the addition of T lymphocytes to culture, and was not associated with B cell transformation. Supernatant Ig could first be detected in virus-activated cultures at day 4, plateaued by day 8, and yielded a mean of 12,500 ng IgG+IgM/ml/50,000 B cells. Thus, HTLV-III/LAV is a potent T cell independent B cell mitogen capable of inducing B cell activation, proliferation, and differentiation comparable in magnitude to that of the most potent B cell activators. This biological property of HTLV-III/LAV may help explain the profound polyclonal B cell activation observed in patients with AIDS and may provide investigators with another probe for investigating the mechanisms of B cell activation

  12. CD19 CAR-targeted T cells induce long-term remission and B Cell Aplasia in an immunocompetent mouse model of B cell acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Marco L Davila

    Full Text Available Although many adults with B cell acute lymphoblastic leukemia (B-ALL are induced into remission, most will relapse, underscoring the dire need for novel therapies for this disease. We developed murine CD19-specific chimeric antigen receptors (CARs and an immunocompetent mouse model of B-ALL that recapitulates the disease at genetic, cellular, and pathologic levels. Mouse T cells transduced with an all-murine CD3ζ/CD28-based CAR that is equivalent to the one being used in our clinical trials, eradicate B-ALL in mice and mediate long-term B cell aplasias. In this model, we find that increasing conditioning chemotherapy increases tumor eradication, B cell aplasia, and CAR-modified T cell persistence. Quantification of recipient B lineage cells allowed us to estimate an in vivo effector to endogenous target ratio for B cell aplasia maintenance. In mice exhibiting a dramatic B cell reduction we identified a small population of progenitor B cells in the bone marrow that may serve as a reservoir for long-term CAR-modified T cell stimulation. Lastly, we determine that infusion of CD8+ CAR-modified T cells alone is sufficient to maintain long-term B cell eradication. The mouse model we report here should prove valuable for investigating CAR-based and other therapies for adult B-ALL.

  13. Physiology of B cells in mice with X-linked immunodeficiency. II. Influence of the thymus and mature T cells on B cell differentiation

    International Nuclear Information System (INIS)

    Evidence is presented that the in vivo differentiation of B cells expressing X-linked immunodeficiency (xid) is controlled by mature T cells. Normal (C57BL/6 X CBA/J)F1 mice were thymectomized (ATx), heavily irradiated, and reconstituted with CBA/N (xid) or CBA/Ca (nondefective) marrow. In contrast to sham-operated mice, ATx recipients of xid marrow showed an almost total absence of Ig+ B cells in lymph nodes (LN) and thoracic duct lymph at 2 mo post-reconstitution; B cells were markedly reduced in the spleen in some mice but only moderately in others. Addition of mature T cells soon after marrow reconstitution substantially abrogated the B cell depletion. In control experiments with nondefective B cells, the number of B cells developing in ATx irradiated recipients of normal (xid-) marrow cells was not detectably lower than in sham-operated recipients. These data imply that a subset of T-dependent B cells is either missing in normal mice or present in only very small numbers

  14. Regulatory activities

    International Nuclear Information System (INIS)

    This publication, compiled in 8 chapters, presents the regulatory system developed by the Nuclear Regulatory Authority (NRA) of the Argentine Republic. The following activities and developed topics in this document describe: the evolution of the nuclear regulatory activity in Argentina; the Argentine regulatory system; the nuclear regulatory laws and standards; the inspection and safeguards of nuclear facilities; the emergency systems; the environmental systems; the environmental monitoring; the analysis laboratories on physical and biological dosimetry, prenatal irradiation, internal irradiation, radiation measurements, detection techniques on nuclear testing, medical program on radiation protection; the institutional relations with national and international organization; the training courses and meeting; the technical information

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

    Directory of Open Access Journals (Sweden)

    Dufner Almut

    2011-03-01

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

  16. Integrated genetic approaches identify the molecular mechanisms of Sox4 in early B-cell development: intricate roles for RAG1/2 and CK1ε.

    Science.gov (United States)

    Mallampati, Saradhi; Sun, Baohua; Lu, Yue; Ma, Haiqing; Gong, Yun; Wang, Donghai; Lee, Ju-Seog; Lin, Kevin; Sun, Xiaoping

    2014-06-26

    Commitment of hematopoietic stem cells to B lineage precursors and subsequent development of B lineage precursors into mature B cells is stringently controlled by stage-specific transcription factors. In this study, we used integrated genetic approaches and systematically determined the role of Sry-related high mobility group box (Sox) 4 and the underlying molecular mechanisms in early B-cell development. We found that Sox4 coordinates multilevel controls in the differentiation of early stage B cells. At the molecular level, Sox4 orchestrates a unique gene regulatory program, and its function was predominantly mediated through a conventional Sox4-binding motif as well as an unconventional GA-binding protein α chain binding motif. Our integrated gene network and functional analysis indicated that Sox4 functions as a bimodular transcription factor and ensures B lineage precursor differentiation through 2 distinct mechanisms. It positively induces gene rearrangements at immunoglobulin heavy chain gene loci by transcriptionally activating the Rag1 and Rag2 genes and negatively regulates Wnt signaling, which is critical for self-renewal, by inducing the expression of casein kinase 1 ε. Our findings illustrate that Sox4 mediates critical fine-tuning of the 2 opposing forces in early B-cell development and also set forth a model for characterization of critical genes whose deficiency, like Sox4 deficiency, is detrimental to this process. PMID:24786772

  17. Cbl Suppresses B Cell Receptor–Mediated Phospholipase C (Plc)-γ2 Activation by Regulating B Cell Linker Protein–Plc-γ2 Binding

    OpenAIRE

    Yasuda, Tomoharu; Maeda, Akito; Kurosaki, Mari; Tezuka, Tohru; Hironaka, Katsunori; Yamamoto, Tadashi; Kurosaki, Tomohiro

    2000-01-01

    Accumulating evidence indicates that the Cbl protein plays a negative role in immune receptor signaling; however, the mode of Cbl action in B cell receptor (BCR) signaling still remains unclear. DT40 B cells deficient in Cbl showed enhanced BCR-mediated phospholipase C (PLC)-γ2 activation, thereby leading to increased apoptosis. A possible explanation for the involvement of Cbl in PLC-γ2 activation was provided by findings that Cbl interacts via its Src homology 2 (SH2) domain with B cell lin...

  18. MYC Negative Rectal B-Cell Lymphoma, Unclassifiable, with Features Intermediate between Diffuse Large B-Cell Lymphoma and Burkitt’s Lymphoma in an Immunocompetent Patient

    OpenAIRE

    Parikh, Jignesh G.; Ted Strom; Ilya Stone

    2013-01-01

    B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt’s lymphoma (BLUI) is a recently added entity to the World Health Organization (WHO) classification to address a grey zone between large B-cell lymphoma (DLBCL) and Burkitt’s lymphoma (BL). These are rare aggressive lymphomas, which were previously also known as Burkitt’s-like lymphoma (BLL). BL and BLUI/BLL of the colon mostly involve the ileocecal region. In the rectum, BL and BLUI/B...

  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. 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.

  1. Rehabilitation or the death penalty: autoimmune B cells in the dock.

    Science.gov (United States)

    Dahal, Lekh N; Cragg, Mark S

    2015-03-01

    CD20-based monoclonal antibodies have become established as treatments for lymphoma, rheumatoid arthritis, systemic lupus erythematosus, vasculitis and dermatomyositis, with the principle therapeutic mechanism relating to B-cell depletion through effector cell engagement. An article by Brühl et al. in this issue of the European Journal of Immunology [Eur. J. Immunol. 2015. 45: 705-715] reveals a fundamentally distinct mechanism of silencing autoimmune B-cell responses. Rather than B-cell depletion, the authors use anti-CD79b antibodies to induce B-cell tolerance and suppress humoral immune responses against collagen to prevent the development of arthritis in mice. Here we highlight the differences in the mechanisms used by anti-CD20 and anti-CD79b Ab therapy and discuss why depletion of B cells may not be required to treat autoimmune arthritis and other B-cell-associated pathologies. PMID:25639261

  2. Semiallogenic fusions of MSI+ tumor cells and activated B cells induce MSI-specific T cell responses

    Directory of Open Access Journals (Sweden)

    Klier Ulrike

    2011-09-01

    Full Text Available Abstract Background Various strategies have been developed to transfer tumor-specific antigens into antigen presenting cells in order to induce cytotoxic T cell responses against tumor cells. One approach uses cellular vaccines based on fusions of autologous antigen presenting cells and allogeneic tumor cells. The fusion cells combine antigenicity of the tumor cell with optimal immunostimulatory capacity of the antigen presenting cells. Microsatellite instability caused by mutational inactivation of DNA mismatch repair genes results in translational frameshifts when affecting coding regions. It has been shown by us and others that these mutant proteins lead to the presentation of immunogenic frameshift peptides that are - in principle - recognized by a multiplicity of effector T cells. Methods We chose microsatellite instability-induced frameshift antigens as ideal to test for induction of tumor specific T cell responses by semiallogenic fusions of microsatellite instable carcinoma cells with CD40-activated B cells. Two fusion clones of HCT116 with activated B cells were selected for stimulation of T cells autologous to the B cell fusion partner. Outgrowing T cells were phenotyped and tested in functional assays. Results The fusion clones expressed frameshift antigens as well as high amounts of MHC and costimulatory molecules. Autologous T cells stimulated with these fusions were predominantly CD4+, activated, and reacted specifically against the fusion clones and also against the tumor cell fusion partner. Interestingly, a response toward 6 frameshift-derived peptides (of 14 tested could be observed. Conclusion Cellular fusions of MSI+ carcinoma cells and activated B cells combine the antigen-presenting capacity of the B cell with the antigenic repertoire of the carcinoma cell. They present frameshift-derived peptides and can induce specific and fully functional T cells recognizing not only fusion cells but also the carcinoma cells. These

  3. Semiallogenic fusions of MSI+ tumor cells and activated B cells induce MSI-specific T cell responses

    International Nuclear Information System (INIS)

    Various strategies have been developed to transfer tumor-specific antigens into antigen presenting cells in order to induce cytotoxic T cell responses against tumor cells. One approach uses cellular vaccines based on fusions of autologous antigen presenting cells and allogeneic tumor cells. The fusion cells combine antigenicity of the tumor cell with optimal immunostimulatory capacity of the antigen presenting cells. Microsatellite instability caused by mutational inactivation of DNA mismatch repair genes results in translational frameshifts when affecting coding regions. It has been shown by us and others that these mutant proteins lead to the presentation of immunogenic frameshift peptides that are - in principle - recognized by a multiplicity of effector T cells. We chose microsatellite instability-induced frameshift antigens as ideal to test for induction of tumor specific T cell responses by semiallogenic fusions of microsatellite instable carcinoma cells with CD40-activated B cells. Two fusion clones of HCT116 with activated B cells were selected for stimulation of T cells autologous to the B cell fusion partner. Outgrowing T cells were phenotyped and tested in functional assays. The fusion clones expressed frameshift antigens as well as high amounts of MHC and costimulatory molecules. Autologous T cells stimulated with these fusions were predominantly CD4+, activated, and reacted specifically against the fusion clones and also against the tumor cell fusion partner. Interestingly, a response toward 6 frameshift-derived peptides (of 14 tested) could be observed. Cellular fusions of MSI+ carcinoma cells and activated B cells combine the antigen-presenting capacity of the B cell with the antigenic repertoire of the carcinoma cell. They present frameshift-derived peptides and can induce specific and fully functional T cells recognizing not only fusion cells but also the carcinoma cells. These hybrid cells may have great potential for cellular immunotherapy and

  4. APECED: Is this a model for failure of T-cell and B-cell tolerance?

    Directory of Open Access Journals (Sweden)

    Nicolas eKluger

    2012-08-01

    Full Text Available APECED and IPEX syndromes show similarities in the clinical presentations and immunological alterations, mainly regarding regulatory T-cells function. T-cell defect may lead to tissue destruction chiefly in endocrine organs. Besides, APECED is characterized by high-titer antibodies against a wide variety of cytokines, that could partly be responsible for the clinical symptoms during APECED, mainly chronic mucocutaneous candidiasis, and linked to antibodies against Th17 cells effector molecules, IL-17 and IL-22. On the other hand, the same antibodies, together with antibodies against type I interferons may be prevent from other immunological diseases, such as psoriasis and systemic lupus erythematous. The same effector Th17 cells, present in the lymphocytic infiltrate of target organs of APECED, could be responsible for the tissue destruction. Here again, the antibodies against the corresponding effector molecules, anti-IL-17 and anti-IL-22 could be protective. The occurrence of several effector mechanisms (CD4+ Th17 cell and CD8+ CTL and the effector cytokines IL-17 and IL-22, and simultaneous existence of regulatory mechanisms (CD4+ and CD8+ Treg and antibodies neutralizing the effect of the effector cytokines may explain the polymorphism of APECED. Almost all the patients develop the characteristic manifestations of the complex, but temporal course and symptoms severity vary considerably, even among siblings. The autoantibody profile does not correlate with the clinical picture. One could speculate that a secondary homeostatic balance between the harmful effector mechanisms, and the favorable regulatory mechanisms, finally define both the extent and severity of the clinical condition in the AIRE defective individuals. The proposed hypothesis that in APECED, in addition to strong tissue destructive mechanisms, a controlling regulatory mechanism does exist, allow us to conclude that APECED could be treated, and even cured, with immunological

  5. Characterization of xenoantiserum produced against B cell acute lymphoblastic leukemia cell line

    OpenAIRE

    Akagi,Tadaatsu; Sonobe, Hiroshi; Miyoshi, Isao; Yoshimoto,Shizuo

    1982-01-01

    Antiserum was produced in white rabbit by intravenously injecting living cells of a B cell acute lymphoblastic leukemia (ALL) line (BALL-1). The reactivity of the antiserum against various lymphoid cell lines was examined by membrane immunofluorescence after appropriate absorption. Serum absorbed with non-T, non-B (NALL-1) and T-ALL (TALL-1) cells recognized B cell antigens distinct from Ia-like antigens on both normal and neoplastic B cells. After further absorption with tonsillar cells or n...

  6. T Cells That Promote B-Cell Maturation in Systemic Autoimmunity

    OpenAIRE

    Weinstein, Jason S.; Hernandez, Sairy G.; Craft, Joe

    2012-01-01

    Follicular helper T (Tfh) cells play an essential role in helping B cells generate antibodies upon pathogen encounters. Such T-cell help classically occurs in germinal centers (GCs) located in B-cell follicles of secondary lymphoid organs, a site of immunoglobulin affinity maturation and isotype switching. B-cell maturation also occurs extrafollicularly, in the red pulp of the spleen and medullary cords in lymph nodes, with plasma cell formation and antibody production. Development of extrafo...

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

    OpenAIRE

    Kulis, Marta; Merkel, Angelika; Heath, Simon; Queirós, Ana C; Schuyler, Ronald P.; Castellano, Giancarlo; Beekman, Renée; Raineri, Emanuele; Esteve, Anna; Clot, Guillem; Verdaguer-Dot, Néria; Duran-Ferrer, Martí; Russiñol, Nuria; Vilarrasa-Blasi, Roser; Ecker, Simone

    2015-01-01

    International audience 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 CpG sites. Early differentiation stages mainly displayed enhancer demethylation, whic...

  8. B cell infection and activation by rabies virus-based vaccines.

    Science.gov (United States)

    Lytle, Andrew G; Norton, James E; Dorfmeier, Corin L; Shen, Shixue; McGettigan, James P

    2013-08-01

    Replication-deficient rabies viruses (RABV) are promising rabies postexposure vaccines due to their prompt and potent stimulation of protective virus neutralizing antibody titers, which are produced in mice by both T-dependent and T-independent mechanisms. To promote such early and robust B cell stimulation, we hypothesized that live RABV-based vaccines directly infect B cells, thereby activating a large pool of antigen-presenting cells (APCs) capable of providing early priming and costimulation to CD4(+) T cells. In this report, we show that live RABV-based vaccine vectors efficiently infect naive primary murine and human B cells ex vivo. Infection of B cells resulted in the significant upregulation of early markers of B cell activation and antigen presentation, including CD69, major histocompatibility complex class II (MHC-II), and CD40 in murine B cells or HLA-DR and CD40 in human B cells compared to mock-infected cells or cells treated with an inactivated RABV-based vaccine. Furthermore, primary B cells infected with a live RABV expressing ovalbumin were able to prime and stimulate naive CD4(+) OT-II T cells to proliferate and to secrete interleukin-2 (IL-2), demonstrating a functional consequence of B cell infection and activation by live RABV-based vaccine vectors. We propose that this direct B cell stimulation by live RABV-based vaccines is a potential mechanism underlying their induction of early protective T cell-dependent B cell responses, and that designing live RABV-based vaccines to infect and activate B cells represents a promising strategy to develop a single-dose postexposure rabies vaccine where the generation of early protective antibody titers is critical. PMID:23760241

  9. Recombinant human interleukin 2 acts as a B cell growth and differentiation promoting factor

    OpenAIRE

    Emmrich, F.; Moll, Heidrun; Markus M Simon

    2009-01-01

    Human B cells appropriately activated by a B cell mitogen are rendered susceptible to human Interleukin 2 (IL-2) as demonstrated with recombinant human IL-2 (rec. h IL-2). They show increased proliferation and drastically enhanced immunoglobulin secretion. Susceptibility to IL-2 is accompanied with the expression of the IL-2 receptor (Tac antigen) on B cells. The data suggest that IL-2 is one of the lymphokines directly involved in the activation of B lymphocytes.

  10. 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.

  11. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

    OpenAIRE

    Shin, Jung Hoon; Park, Se-Ho

    2013-01-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-γ by NKT cells, concomitant with a d...

  12. B cells help alloreactive T cells differentiate into memory T cells1

    OpenAIRE

    Ng, Yue-Harn; Oberbarnscheidt, Martin H.; Chandramoorthy, Harish Chinna Konda; Hoffman, Rosemary; Chalasani, Geetha

    2010-01-01

    B cells are recognized as effector cells in allograft rejection that are dependent upon T cell help to produce alloantibodies causing graft injury. It is not known if B cells can also help T cells differentiate into memory cells in the alloimmune response. We found that in B cell-deficient hosts, differentiation of alloreactive T cells into effectors was intact whereas their development into memory T cells was impaired. To test if B cell help for T cells was required for their continued diffe...

  13. Affinity-purified interleukin 2 induces proliferation of large but not small B cells.

    OpenAIRE

    Mond, J J; C. Thompson; Finkelman, F.D.; Farrar, J.; Schaefer, M.; Robb, R J

    1985-01-01

    Immunoaffinity-purified interleukin 2 (IL2) stimulated proliferation of large but not small B cells. Stimulation was observed even when B cells were cultured at very low cell densities (3 X 10(4) per microwell containing 0.2 ml of medium). Addition of small numbers of purified splenic T cells did not enhance the IL2-induced B-cell proliferative response. These results suggest that IL2 was not operating through contaminating T cells. B cells cultured with anti-Ig antibody in vitro showed enhan...

  14. Clonal expansion of immunoglobulin M+CD27+ B cells in HCV-associated mixed cryoglobulinemia

    OpenAIRE

    Charles, Edgar D.; Green, Rashidah M.; Marukian, Svetlana; Talal, Andrew H.; Lake-Bakaar, Gerond V.; Jacobson, Ira M.; Rice, Charles M.; Dustin, Lynn B.

    2008-01-01

    Hepatitis C virus (HCV) is associated with B-cell lymphoproliferative disorders such as mixed cryoglobulinemia (MC) and B-cell non-Hodgkin lymphoma (B-NHL). The pathogenesis of these disorders remains unclear, and it has been proposed that HCV drives the pro-liferation of B cells. Here we demonstrate that certain HCV+MC+ subjects have clonal expansions of immunoglobulin M (IgM)+κ+IgDlow/−CD21lowCD27+ B cells. Using RT-PCR to amplify Ig from these singly sorted cells, we show that these predom...

  15. Infection and Persistence of Rhesus Monkey Rhadinovirus in Immortalized B-Cell Lines

    OpenAIRE

    Bilello, John P.; Lang, Sabine M.; Wang, Fred; Aster, Jon C.; Desrosiers, Ronald C.

    2006-01-01

    Similar to its close relative human herpesvirus 8, rhesus monkey rhadinovirus (RRV) persists predominantly in B cells of its natural host. Rhesus monkey B-cell lines immortalized by the Epstein-Barr-related virus from rhesus monkeys (rhEBV) were used as targets for infection by RRV. These cultured B cells were susceptible to infection by RRV and continued to produce low titers of RRV for months of continuous culture. Infection by RRV did not detectably alter the growth rates of these B-cell l...

  16. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production

    OpenAIRE

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C.; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1 −/− mice limits...

  17. Multifocal Extranodal Involvement of Diffuse Large B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Devrim Cabuk

    2013-01-01

    Full Text Available Endobronchial involvement of extrapulmonary malignant tumors is uncommon and mostly associated with breast, kidney, colon, and rectum carcinomas. A 68-year-old male with a prior diagnosis of colon non-Hodgkin lymphoma (NHL was admitted to the hospital with a complaint of cough, sputum, and dyspnea. The chest radiograph showed right hilar enlargement and opacity at the right middle zone suggestive of a mass lesion. Computed tomography of thorax revealed a right-sided mass lesion extending to thoracic wall with the destruction of the third and the fourth ribs and a right hilar mass lesion. Fiberoptic bronchoscopy was performed in order to evaluate endobronchial involvement and showed stenosis with mucosal tumor infiltration in right upper lobe bronchus. The pathological examination of bronchoscopic biopsy specimen reported diffuse large B-cell lymphoma and the patient was accepted as the endobronchial recurrence of sigmoid colon NHL. The patient is still under treatment of R-ICE (rituximab-ifosfamide-carboplatin-etoposide chemotherapy and partial regression of pulmonary lesions was noted after 3 courses of treatment.

  18. Primary Mediastinal Large B-Cell Lymphoma during Pregnancy

    Directory of Open Access Journals (Sweden)

    Cesar A. Perez

    2012-01-01

    Full Text Available Non-Hodgkin’s Lymphoma (NHL rarely presents during pregnancy and primary mediastinal large B-cell lymphoma (PMLBCL accounts for approximately 2.5% of patients with NHL. The case of a 22-year-old woman who was diagnosed with Stage IIA PMLBCL during week 13 of her intrauterine pregnancy is described. The staging consisted in computed tomography (CT of the chest and magnetic resonance imaging (MRI of the abdomen and pelvis. She was managed with R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for a total of six cycles and, because of the early presentation during the second trimester, she received the entire chemotherapy course during the pregnancy. She delivered a healthy baby at 34 weeks of pregnancy and a 18FDG-PET/CT scan demonstrated complete remission after delivery. After 20 months of follow up she remains with no evidence of disease and her 1-year-old son has shown no developmental delays or physical abnormalities. PMLBCL, although an uncommon subgroup of DLBCL, may present during pregnancy and R-CHOP should be considered as one suitable option in this complex scenario.

  19. Induction of apoptosis in chicken bursal B cells

    International Nuclear Information System (INIS)

    Cell death in general can be a physiological process of cell number regulation in tissue, or it can be the result of exo or endogenous injuries, such a low-dose of radiation. Chicken B cell population in the bursa of Fabricius are very susceptible to PCD. Our present studies concern the development of radiation damage of chicken defence mechanisms. In 6 experiments pathogen free chicken were irradiated by gamma rays with the total doses of 0.25, 0.5, 1.0, 2.0 and 4.0 Gy. The induction of apoptosis was checked by Flow-cyto-meter 12 h after irradiation in bursa cell suspension. There is some increase in the number of induced apoptotic cells 12 h after irradiation at the dose 0.5-.4.0 Gy. There were no significant changes in the proportion of proliferating lymphocytes (G2 M), but cellularity decreased significantly at dose 2.0 and 4.0 Gy/12 h after irradiation. (author)

  20. Antibody and B cell responses to Plasmodium sporozoites

    Directory of Open Access Journals (Sweden)

    Johanna N Dups

    2014-11-01

    Full Text Available Antibodies are capable of blocking infection of the liver by Plasmodium sporozoites. Accordingly the induction of anti-sporozoite antibodies is a major aim of various vaccine approaches to malaria. In recent years our knowledge of the specificity and quantities of antibodies required for protection has been greatly expanded by clinical trials of various whole sporozoite and subunit vaccines. Moreover, the development of humanized mouse models and transgenic parasites have also aided our ability to assess the specificity of antibodies and their ability to block infection. Nonetheless, considerable gaps remain in our knowledge - in particular in understanding what antigens are recognized by infection blocking antibodies and in knowing how we can induce robust, long-lived antibody responses. Maintaining high levels of circulating antibodies is likely to be of primary importance, as antibodies must block infection in the short time it takes for sporozoites to reach the liver from the skin. It is clear that a better understanding of the development of protective B cell-mediated immunity will aid the development and refinement of malaria vaccines.

  1. B regulatory cells are increased in hypercholesterolaemic mice and protect from lesion development via IL-10.

    Science.gov (United States)

    Strom, Asa C; Cross, Amanda J; Cole, Jennifer E; Blair, Paul A; Leib, Christoph; Goddard, Michael E; Rosser, Elizabeth C; Park, Inhye; Hultgårdh Nilsson, Anna; Nilsson, Jan; Mauri, Claudia; Monaco, Claudia

    2015-10-01

    Whilst innate B1-B cells are atheroprotective, adaptive B2-B cells are considered pro-atherogenic. Different subsets of B regulatory cells (B(reg)) have been described. In experimental arthritis and lupus-like disease, B(reg) are contained within the CD21(hi)CD23(hi)CD24(hi) B cell pool. The existence and role of B(reg) in vascular disease is not known. We sought to investigate the existence, identity and location of B(reg) in vascular disease. The representation of B2-B cell subsets in the spleens and lymph nodes (LNs) of Apolipoprotein E(-/-) (ApoE(-/-)) mice compared to controls was characterised by flow cytometry. Additionally, we utilised a model of neointima formation based on the placement of a perivascular collar around the carotid artery in ApoE(-/-) mice to ascertain whether B cells and B cell subsets confer protection against lesion development. Adoptive transfer of B cells was performed from wild type or genetically modified mice. We showed that CD21(hi)CD23(hi)CD24(hi) B cells are unexpectedly increased in the draining LNs of ApoE(-/-) mice. Adoptive transfer of LN-derived B2-B cells or purified CD21(hi)CD23(hi)CD24(hi) B cells to syngeneic mice reduced lesion size and inflammation without changing serum cholesterol levels. Follicular B2-B cells did not confer protection. IL-10 blockade or transfer of IL10-deficient B cells prevented LN-derived B cell-mediated protection. This is the first identification of a specific LN-derived B2-B(reg) subset that confers IL-10 mediated protection from neointima formation. This may open the way for immune modulatory approaches in cardiovascular disease. PMID:26063196

  2. OCA-B integrates B cell antigen receptor-, CD40L- and IL 4-mediated signals for the germinal center pathway of B cell development.

    OpenAIRE

    Qin, X F; Reichlin, A; Luo, Y.; Roeder, R. G.; Nussenzweig, M.C.

    1998-01-01

    Many of the key decisions in lymphocyte differentiation and activation are dependent on integration of antigen receptor and co-receptor signals. Although there is significant understanding of these receptors and their signaling pathways, little is known about the molecular requirements for signal integration at the level of activation of gene expression. Here we show that in primary B cells, expression of the B-cell specific transcription coactivator OCA-B (also known as OBF-1 or Bob-1) is re...

  3. 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. PMID:27125377

  4. Photoisomerisable molecules

    OpenAIRE

    Peris Fajarnes, Eduardo Víctor; Mata Martínez, José Antonio; Márquez Linares, Francisco Manuel; Sabater Picot, María José

    2005-01-01

    [EN] The invention relates to a molecule comprising at least one carbon-carbon double bond which is substituted by at least one cyclopentadienyl-metal-cyclopentadienyl complex, having the cis/trans isomerisation property, in a reversible manner in response to the absorption of light. Preferably, the rest of the molecule comprises a dendrimer of any generation, advantageously of the polypropylenimine octaamine type. The inventive molecule can be used as a molecular switch and in various differ...

  5. The Analysis of B-Cell Epitopes of Influenza Virus Hemagglutinin.

    Science.gov (United States)

    Shcherbinin, D N; Alekseeva, S V; Shmarov, M M; Smirnov, Yu A; Naroditskiy, B S; Gintsburg, A L

    2016-01-01

    Vaccination has been successfully used to prevent influenza for a long time. Influenza virus hemagglutinin (HA), which induces a humoral immune response in humans and protection against the flu, is the main antigenic component of modern influenza vaccines. However, new seasonal and pandemic influenza virus variants with altered structures of HA occasionally occur. This allows the pathogen to avoid neutralization with antibodies produced in response to previous vaccination. Development of a vaccine with the new variants of HA acting as antigens takes a long time. Therefore, during an epidemic, it is important to have passive immunization agents to prevent and treat influenza, which can be monoclonal or single-domain antibodies with universal specificity (broad-spectrum agents). We considered antibodies to conserved epitopes of influenza virus antigens as universal ones. In this paper, we tried to characterize the main B-cell epitopes of hemagglutinin and analyze our own and literature data on broadly neutralizing antibodies. We conducted a computer analysis of the best known conformational epitopes of influenza virus HAs using materials of different databases. The analysis showed that the core of the HA molecule, whose antibodies demonstrate pronounced heterosubtypic activity, can be used as a target for the search for and development of broad-spectrum antibodies to the influenza virus. PMID:27099781

  6. Pathophysiological significance and therapeutic targeting of germinal center kinase in diffuse large B-cell lymphoma.

    Science.gov (United States)

    Matthews, Julie Marie; Bhatt, Shruti; Patricelli, Matthew P; Nomanbhoy, Tyzoon K; Jiang, Xiaoyu; Natkunam, Yasodha; Gentles, Andrew J; Martinez, Ezequiel; Zhu, Daxing; Chapman, Jennifer Rose; Cortizas, Elena; Shyam, Ragini; Chinichian, Shideh; Advani, Ranjana; Tan, Li; Zhang, Jianming; Choi, Hwan Geun; Tibshirani, Robert; Buhrlage, Sara J; Gratzinger, Dita; Verdun, Ramiro; Gray, Nathanael S; Lossos, Izidore S

    2016-07-14

    Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma, yet 40% to 50% of patients will eventually succumb to their disease, demonstrating a pressing need for novel therapeutic options. Gene expression profiling has identified messenger RNAs that lead to transformation, but critical events transforming cells are normally executed by kinases. Therefore, we hypothesized that previously unrecognized kinases may contribute to DLBCL pathogenesis. We performed the first comprehensive analysis of global kinase activity in DLBCL, to identify novel therapeutic targets, and discovered that germinal center kinase (GCK) was extensively activated. GCK RNA interference and small molecule inhibition induced cell-cycle arrest and apoptosis in DLBCL cell lines and primary tumors in vitro and decreased the tumor growth rate in vivo, resulting in a significantly extended lifespan of mice bearing DLBCL xenografts. GCK expression was also linked to adverse clinical outcome in a cohort of 151 primary DLBCL patients. These studies demonstrate, for the first time, that GCK is a molecular therapeutic target in DLBCL tumors and that inhibiting GCK may significantly extend DLBCL patient survival. Because the majority of DLBCL tumors (∼80%) exhibit activation of GCK, this therapy may be applicable to most patients. PMID:27151888

  7. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...

  8. Epstein-Barr virus nuclear protein EBNA3C directly induces expression of AID and somatic mutations in B cells.

    Science.gov (United States)

    Kalchschmidt, Jens S; Bashford-Rogers, Rachael; Paschos, Kostas; Gillman, Adam C T; Styles, Christine T; Kellam, Paul; Allday, Martin J

    2016-05-30

    Activation-induced cytidine deaminase (AID), the enzyme responsible for induction of sequence variation in immunoglobulins (Igs) during the process of somatic hypermutation (SHM) and also Ig class switching, can have a potent mutator phenotype in the development of lymphoma. Using various Epstein-Barr virus (EBV) recombinants, we provide definitive evidence that the viral nuclear protein EBNA3C is essential in EBV-infected primary B cells for the induction of AID mRNA and protein. Using lymphoblastoid cell lines (LCLs) established with EBV recombinants conditional for EBNA3C function, this was confirmed, and it was shown that transactivation of the AID gene (AICDA) is associated with EBNA3C binding to highly conserved regulatory elements located proximal to and upstream of the AICDA transcription start site. EBNA3C binding initiated epigenetic changes to chromatin at specific sites across the AICDA locus. Deep sequencing of cDNA corresponding to the IgH V-D-J region from the conditional LCL was used to formally show that SHM is activated by functional EBNA3C and induction of AID. These data, showing the direct targeting and induction of functional AID by EBNA3C, suggest a novel role for EBV in the etiology of B cell cancers, including endemic Burkitt lymphoma. PMID:27217538

  9. The ibrutinib B-cell proliferation inhibition is potentiated in vitro by dexamethasone: Application to chronic lymphocytic leukemia.

    Science.gov (United States)

    Manzoni, Delphine; Catallo, Régine; Chebel, Amel; Baseggio, Lucile; Michallet, Anne-Sophie; Roualdes, Olivier; Magaud, Jean-Pierre; Salles, Gilles; Ffrench, Martine

    2016-08-01

    New B-cell receptor-targeted therapies such as ibrutinib, a Bruton tyrosine kinase inhibitor, are now proposed for lymphoid pathologies. The putative benefits of its combination with glucocorticoids were evaluated here. We compared the effects of dexamethasone (DXM), ibrutinib and their in vitro combination on proliferation and metabolic stress markers in stimulated normal B-lymphocytes and in malignant lymphocytes from chronic lymphocytic leukemia (CLL) patients. In both cellular models, cell cycle progression was globally inhibited by DXM and/or ibrutinib. This inhibition was significantly amplified by DXM addition to ibrutinib and was related to a significant decrease in the expression of the cell cycle regulatory proteins CDK4 and cyclin E. Apoptosis increased especially with DXM/ibrutinib combination and was associated with a significant decrease in Mcl-1 expression. Treatment effects on metabolic stress were evaluated by DNA damage recognition after 53BP1 foci labeling. The percentage of cells with more than five 53BP1 foci decreased significantly with ibrutinib in normal and CLL lymphocytes. This decrease was strongly reinforced, in CLL, by DXM addition. Our data indicated that, in vitro, DXM potentiated antiproliferative effects of ibrutinib and decreased DNA damage in lymphoid B-cells. Thus their combination may be proposed for CLL treatment. PMID:27235717

  10. IL-15 expression on RA synovial fibroblasts promotes B cell survival.

    Directory of Open Access Journals (Sweden)

    Marta Benito-Miguel

    Full Text Available INTRODUCTION: The purpose of this study was to examine the role of RA Synovial Fibroblast (RASFib IL-15 expression on B cell survival. METHODS: Magnetically sorted peripheral blood memory B cells from 15 healthy subjects were cocultured with RASFib. RESULTS: RASFib constitutively expressed membrane IL-15. Survival of isolated B cells cultured for 6 days, below 5%, was extended in coculture with RASFib to 52+/-8% (p<0.001. IL-15 neutralizing agents but not isotype controls, reduced this rate to 31+/-6% (p<0.05. Interestingly, rhIL-15 had no effect on isolated B cells but significantly increased their survival in coculture with RASFib. In parallel, B cell IL-15R chains were upregulated in cocultures. BAFF and VCAM-1, that are expressed on RASFib, were tested as potential candidates involved in upregulating B cell IL-15R. Culture of B cells in the presence of rhBAFF or rhVCAM-1 resulted in significantly increased survival, together with upregulation of all three IL-15R chains; in parallel, rhIL-15 potentiated the anti-apoptotic effect of BAFF and VCAM-1. Both BAFF and VCAM-1 neutralizing agents downmodulated the effect of RASFib on B cell survival and IL-15R expression. In parallel, rhIL-15 had a lower effect on the survival of B cells cocultured with RASFib in the presence of BAFF or VCAM-1 neutralizing agents. Peripheral blood B cells from 15 early RA patients demonstrated an upregulated IL-15R and increased survival in cocultures. CONCLUSION: IL-15 expression on RASFib significantly contributes to the anti-apoptotic effect of RASFib on B cells. IL-15 action is facilitated by BAFF and VCAM-1 expressed on RASFib, through an upregulation of IL-15R chains.

  11. Induction of heat shock proteins in B-cell exosomes.

    Science.gov (United States)

    Clayton, Aled; Turkes, Attilla; Navabi, Hossein; Mason, Malcolm D; Tabi, Zsuzsanna

    2005-08-15

    Exosomes are nanometer-sized vesicles secreted by a diverse range of live cells that probably have physiological roles in modulating cellular immunity. The extracellular factors that regulate the quantity and phenotype of exosomes produced are poorly understood, and the properties of exosomes that dictate their immune functions are not yet clear. We investigated the effect of cellular stress on the exosomes produced by B-lymphoblastoid cell lines. Under steady-state conditions, the exosomes were positive for hsp27, hsc70, hsp70 and hsp90, and other recognised exosome markers such as MHC class I, CD81, and LAMP-2. Exposing cells to heat stress (42 degrees C for up to 3 hours), resulted in a marked increase in these heat shock proteins (hsps), while the expression of other stress proteins such as hsp60 and gp96 remained negative, and other exosome markers remained unchanged. Stress also triggered a small increase in the quantity of exosomes produced [with a ratio of 1.245+/-0.07 to 1 (mean+/-s.e.m., n=20) of 3-hour-stress-exosomes to control-exosomes]. Flow-cytometric analysis of exosome-coated beads and immuno-precipitation of intact exosomes demonstrated that hsps were located within the exosome lumen, and not present at the exosome-surface, suggesting that such exosomes may not interact with target cells through cell-surface hsp-receptors. Functional studies further supported this finding, in that exosomes from control or heat-stressed B cells did not trigger dendritic cell maturation, assessed by analysis of dendritic-cell-surface phenotype, and cytokine secretion profile. Our findings demonstrate that specific alterations in exosome phenotype are a hitherto unknown component of the cellular response to environmental stress and their extracellular function does not involve the direct activation of dendritic cells. PMID:16046478

  12. SPIB and BATF provide alternate determinants of IRF4 occupancy in diffuse large B-cell lymphoma linked to disease heterogeneity.

    Science.gov (United States)

    Care, Matthew A; Cocco, Mario; Laye, Jon P; Barnes, Nicholas; Huang, Yuanxue; Wang, Ming; Barrans, Sharon; Du, Ming; Jack, Andrew; Westhead, David R; Doody, Gina M; Tooze, Reuben M

    2014-07-01

    Interferon regulatory factor 4 (IRF4) is central to the transcriptional network of activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL), an aggressive lymphoma subgroup defined by gene expression profiling. Since cofactor association modifies transcriptional regulatory input by IRF4, we assessed genome occupancy by IRF4 and endogenous cofactors in ABC-DLBCL cell lines. IRF4 partners with SPIB, PU.1 and BATF genome-wide, but SPIB provides the dominant IRF4 partner in this context. Upon SPIB knockdown IRF4 occupancy is depleted and neither PU.1 nor BATF acutely compensates. Integration with ENCODE data from lymphoblastoid cell line GM12878, demonstrates that IRF4 adopts either SPIB- or BATF-centric genome-wide distributions in related states of post-germinal centre B-cell transformation. In primary DLBCL high-SPIB and low-BATF or the reciprocal low-SPIB and high-BATF mRNA expression links to differential gene expression profiles across nine data sets, identifying distinct associations with SPIB occupancy, signatures of B-cell differentiation stage and potential pathogenetic mechanisms. In a population-based patient cohort, SPIBhigh/BATFlow-ABC-DLBCL is enriched for mutation of MYD88, and SPIBhigh/BATFlow-ABC-DLBCL with MYD88-L265P mutation identifies a small subgroup of patients among this otherwise aggressive disease subgroup with distinct favourable outcome. We conclude that differential expression of IRF4 cofactors SPIB and BATF identifies biologically and clinically significant heterogeneity among ABC-DLBCL. PMID:24875472

  13. Mouse dendritic cells pulsed with capsular polysaccharide induce resistance to lethal pneumococcal challenge: roles of T cells and B cells.

    Directory of Open Access Journals (Sweden)

    Noam Cohen

    Full Text Available Mice are exceedingly sensitive to intra-peritoneal (IP challenge with some virulent pneumococci (LD50 = 1 bacterium. To investigate how peripheral contact with bacterial capsular polysaccharide (PS antigen can induce resistance, we pulsed bone marrow dendritic cells (BMDC of C57BL/6 mice with type 4 or type 3 PS, injected the BMDC intra-foot pad (IFP and challenged the mice IP with supra-lethal doses of pneumococci. We examined the responses of T cells and B cells in the draining popliteal lymph node and measured the effects on the bacteria in the peritoneum and blood. We now report that: 1 The PS co-localized with MHC molecules on the BMDC surface; 2 PS-specific T and B cell proliferation and IFNγ secretion was detected in the draining popliteal lymph nodes on day 4; 3 Type-specific resistance to lethal IP challenge was manifested only after day 5; 4 Type-specific IgM and IgG antibodies were detected in the sera of only some of the mice, but B cells were essential for resistance; 5 Control mice vaccinated with a single injection of soluble PS did not develop a response in the draining popliteal lymph node and were not protected; 6 Mice injected with unpulsed BMDC also did not resist challenge: In unprotected mice, pneumococci entered the blood shortly after IP inoculation and multiplied exponentially in both blood and peritoneum killing the mice within 20 hours. Mice vaccinated with PS-pulsed BMDC trapped the bacteria in the peritoneum. The trapped bacteria proliferated exponentially IP, but died suddenly at 18-20 hours. Thus, a single injection of PS antigen associated with intact BMDC is a more effective vaccine than the soluble PS alone. This model system provides a platform for studying novel aspects of PS-targeted vaccination.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Identification of uniquely expressed transcription factors in highly purified B-cell lymphoma samples

    DEFF Research Database (Denmark)

    Andréasson, Ulrika; Edén, Patrik; Peterson, Carsten; Högerkorp, Carl-Magnus; Jerkeman, Mats; Andersen, Niels Smedegaard; Berglund, Mattias; Sundström, Christer; Rosenquist, Richard; Borrebaeck, Carl A K; Ek, Sara

    2010-01-01

    Transcription factors (TFs) are critical for B-cell differentiation, affecting gene expression both by repression and transcriptional activation. Still, this information is not used for classification of B-cell lymphomas (BCLs). Traditionally, BCLs are diagnosed based on a phenotypic resemblance ...

  16. T-dependent B-cell activation is signalled by an early increase in potassium influx

    DEFF Research Database (Denmark)

    Owens, T; Kaplan, J G

    1982-01-01

    (previously demonstrated when B and T lymphocytes were separately stimulated) also occurs when B cells are stimulated through cooperation with mitogen-activated T cells, and is also detectable early in culture. T-dependent activation of B cells is therefore detectable considerably earlier than by conventional...

  17. Study of BKM120 & Rituximab in Patients With Relapsed or Refractory Indolent B-Cell Lymphoma

    Science.gov (United States)

    2016-06-14

    Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

  18. DEFECTS IN INSULIN-SECRETION IN NIDDM - B-CELL GLUCOSE INSENSITIVITY OR GLUCOSE TOXICITY

    NARCIS (Netherlands)

    VANHAEFTEN, TW

    1993-01-01

    In NIDDM, first-phase insulin release to glucose is (almost) absent. However, in contrast to older studies which suggested that in NIDDM the B-cell is ''blind'' for glucose, recent evidence indicates that the B-cell is not insensitive for glucose as far as second phase release is concerned. This sug

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    . We show at the single cell level that natural Pf infection induces the development of classical memory B cells (CM) and atypical memory B cells (AtM) that produce broadly neutralizing antibodies against blood stage Pf parasites. CM and AtM contribute to anti-Pf serum IgG production, but only AtM show...

  20. Expression pattern of FCRL (FREB, FcRX) in normal and neoplastic human B cells.

    Science.gov (United States)

    Masir, Noraidah; Jones, Margaret; Pozzobon, Michela; Marafioti, Teresa; Volkova, Olga Y; Mechetina, Ludmila V; Hansmann, Martin-Leo; Natkunam, Yasodha; Taranin, Alexander V; Mason, David Y

    2004-11-01

    FCRL (also known as FREB and FcRX) is a recently described member of the family of Fc receptors for immunoglobulin G (IgG). In the present study we analysed its expression in normal and neoplastic lymphoid tissue using immunohistochemical techniques. FCRL was preferentially expressed in a proportion of germinal centre cells and, more weakly, in mantle zone B cells. In addition, strong labelling was observed in marginal zone B cells in the spleen, representing one of the few markers for this cell type. The majority of cases of small B-cell lymphoma, diffuse large B-cell lymphoma and lymphocyte predominance Hodgkin's disease were positive for FCRL. However, the number of positive cells varied widely, and in consequence we could not define a cut-off that distinguished subsets of diffuse large B-cell lymphoma. Our results also showed that FCRL tended to be negative in T-cell-rich B-cell lymphoma and in classical Hodgkin's disease. FCRL may therefore represent a novel marker for normal B cells (e.g. splenic marginal zone cells) and may also be useful as a potential marker of B-cell neoplasms. PMID:15491296

  1. A multi-scale model for correlation in B cell VDJ usage of zebrafish

    International Nuclear Information System (INIS)

    The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment

  2. A multi-scale model for correlation in B cell VDJ usage of zebrafish

    Science.gov (United States)

    Pan, Keyao; Deem, Michael W.

    2011-10-01

    The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment.

  3. A NOVel ELISPOT assay to quantify HLA-specific B cells in HLA-immunized individuals

    NARCIS (Netherlands)

    Heidt, S.; Roelen, D.L.; Vaal, Y.J. de; Kester, M.G.; Eijsink, C.; Thomas, S.; Besouw, N.M. van; Volk, H.D.; Weimar, W.; Claas, F.H.; Mulder, A.

    2012-01-01

    Quantification of the humoral alloimmune response is generally achieved by measuring serum HLA antibodies, which provides no information about the cells involved in the humoral immune response. Therefore, we have developed an HLA-specific B-cell ELISPOT assay allowing for quantification of B cells p

  4. B-cell clonality in the liver of hepatitis C virus-infected patients

    Institute of Scientific and Technical Information of China (English)

    He-Bin Fan; You-Fu Zhu; An-Shen Chen; Mu-Xiu Zhou; Fu-Ming Yan; Xiao-Ju Ma; Hao Zhou

    2009-01-01

    AIM: The association of hepatitis C virus (HCV) infection with type Ⅱ mixed cryoglobulinemia is well established, but the role of HCV in B-cell lymphoma remains controversial. In patients with HCV infection, B-cell clonal expansions have been detected in peripheral blood and bone marrow, and a high been documented. Liver biopsies in chronic HCV infection frequently show portal lymphoid infiltrates with features of B follicles, whose clonality has not yet been investigated. The object of this study was to determine the frequency of liver-infiltrating monoclonal B-cells in 40 patients with HCV infection. METHODS: Eight hundred and forty-eight patients were studied prospectively, including 40 HCV-positive patients and 808 patients with chronic hepatitis B virus (HBV) infection. Immunohistochemical study for B- and T-cell markers was performed on the paraffin-embedded liver tissue sections. The clonality of lymphoid B-cells was tested using a polymerase chain reaction (PCR) approach designed to identify immunoglobulin heavy chain gene ( IgH) rearrangements. RESULTS: Liver-infiltrating monoclonal B-cells were detected in the liver for 4 (10%) of 40 HCV-positive patients but were present in only 3 (0.37%) of 808 liver biopsy specimens with chronic HBV infection. Chi-square testing showed that the monoclonal B-cells infiltration in the liver was more frequent in the HCV-infected patients ( P = 0.000). A clonal IgH rearrangement was detected in 5 (71.4%) of 7 liver biopsy specimens with monoclonal B-cells infiltration. In 2 of 5 patients with both a clonal B-cell expansion and monoclonal B-cells infiltration in the liver, a definite B-cell malignancy was finally diagnosed. CONCLUSION: Liver-infiltrating monoclonal B-cells are detected in the liver of patients with chronic HCV and HBV infection. A high percentage of patients with monoclonal B-cells infiltration and B-cell clonality in the liver were finally diagnosed as having a definite B-cell malignancy.

  5. Virus-Like Display of a Neo-Self Antigen Reverses B Cell Anergy in a B Cell Receptor Transgenic Mouse Model1

    Science.gov (United States)

    Chackerian, Bryce; Durfee, Marisa R.; Schiller, John T.

    2012-01-01

    The ability to distinguish between self and foreign Ags is a central feature of immune recognition. For B cells, however, immune tolerance is not absolute, and factors that include Ag valency, the availability of T help, and polyclonal B cell stimuli can influence the induction of autoantibody responses. Here, we evaluated whether multivalent virus-like particle (VLP)-based immunogens could induce autoantibody responses in well-characterized transgenic (Tg) mice that express a soluble form of hen egg lysozyme (HEL) and in which B cell tolerance to HEL is maintained by anergy. Immunization with multivalent VLP-arrayed HEL, but not a trivalent form of HEL, induced high-titer Ab responses against HEL in both soluble HEL Tg mice and double Tg mice that also express a monoclonal HEL-specific BCR. Induction of autoantibodies against HEL was not dependent on coadministration of strong adjuvants, such as CFA. In contrast to previous data showing the T-independent induction of Abs to foreign epitopes on VLPs, the ability of HEL-conjugated VLPs to induce anti-HEL Abs in tolerant mice was dependent on the presence of CD4+ Th cells, and could be enhanced by the presence of pre-existing cognate T cells. In in vitro studies, VLP-conjugated HEL was more potent than trivalent HEL in up-regulating surface activation markers on purified anergic B cells. Moreover, immunization with VLP-HEL reversed B cell anergy in vivo in an adoptive transfer model. Thus, Ag multivalency and T help cooperate to reverse B cell anergy, a major mechanism of B cell tolerance. PMID:18424700

  6. Preparation of antisera specific for human B cells by immunization of rabbits with immune complexes

    International Nuclear Information System (INIS)

    Three rabbit antisera are described which are specific without absorption (titer 1:100) for separated human B cells, as measured by complement and non-complement fixing assays. The method of production of these sera involved injections of rabbits with precipitin lines formed between 10μ1 of three separate detergent solubilized membrane preparations and 4μ1 aliquots of rabbit antisera to human B cells. In addition to being B cell specific, the three sera block the MLC reaction, inhibit aggregated IgG binding to B cells, and show differential degrees of B cell lysis when tested on a panel of separated B and T cells. These and other properties suggest that the target specificities of the antibodies are the human equivalent of the murine Ia antigens. (author)

  7. 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

    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...... 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...

  8. 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.

  9. 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. PMID:1384316

  10. Patients with Tuberculosis Have a Dysfunctional Circulating B-Cell Compartment, Which Normalizes following Successful Treatment

    Science.gov (United States)

    del Nonno, Franca; Baiocchini, Andrea; Petrone, Linda; Vanini, Valentina; Smits, Hermelijn H.; Palmieri, Fabrizio; Goletti, Delia; Ottenhoff, Tom H. M.

    2016-01-01

    B-cells not only produce immunoglobulins and present antigens to T-cells, but also additional key roles in the immune system. Current knowledge on the role of B-cells in infections caused by intracellular bacteria is fragmentary and contradictory. We therefore analysed the phenotypical and functional properties of B-cells during infection and disease caused by Mycobacterium tuberculosis (Mtb), the bacillus causing tuberculosis (TB), and included individuals with latent TB infection (LTBI), active TB, individuals treated successfully for TB, and healthy controls. Patients with active or treated TB disease had an increased proportion of antibodies reactive with mycobacteria. Patients with active TB had reduced circulating B-cell frequencies, whereas only minor increases in B-cells were detected in the lungs of individuals deceased from TB. Both active TB patients and individuals with LTBI had increased relative fractions of B-cells with an atypical phenotype. Importantly, these B-cells displayed impaired proliferation, immunoglobulin- and cytokine- production. These defects disappeared upon successful treatment. Moreover, T-cell activity was strongest in individuals successfully treated for TB, compared to active TB patients and LTBI subjects, and was dependent on the presence of functionally competent B-cells as shown by cellular depletion experiments. Thus, our results reveal that general B-cell function is impaired during active TB and LTBI, and that this B-cell dysfunction compromises cellular host immunity during Mtb infection. These new insights may provide novel strategies for correcting Mtb infection-induced immune dysfunction towards restored protective immunity. PMID:27304615

  11. 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.

  12. YY1 plays an essential role at all stages of B-cell differentiation.

    Science.gov (United States)

    Kleiman, Eden; Jia, Haiqun; Loguercio, Salvatore; Su, Andrew I; Feeney, Ann J

    2016-07-01

    Ying Yang 1 (YY1) is a ubiquitously expressed transcription factor shown to be essential for pro-B-cell development. However, the role of YY1 in other B-cell populations has never been investigated. Recent bioinformatics analysis data have implicated YY1 in the germinal center (GC) B-cell transcriptional program. In accord with this prediction, we demonstrated that deletion of YY1 by Cγ1-Cre completely prevented differentiation of GC B cells and plasma cells. To determine if YY1 was also required for the differentiation of other B-cell populations, we deleted YY1 with CD19-Cre and found that all peripheral B-cell subsets, including B1 B cells, require YY1 for their differentiation. Transitional 1 (T1) B cells were the most dependent upon YY1, being sensitive to even a half-dosage of YY1 and also to short-term YY1 deletion by tamoxifen-induced Cre. We show that YY1 exerts its effects, in part, by promoting B-cell survival and proliferation. ChIP-sequencing shows that YY1 predominantly binds to promoters, and pathway analysis of the genes that bind YY1 show enrichment in ribosomal functions, mitochondrial functions such as bioenergetics, and functions related to transcription such as mRNA splicing. By RNA-sequencing analysis of differentially expressed genes, we demonstrated that YY1 normally activates genes involved in mitochondrial bioenergetics, whereas it normally down-regulates genes involved in transcription, mRNA splicing, NF-κB signaling pathways, the AP-1 transcription factor network, chromatin remodeling, cytokine signaling pathways, cell adhesion, and cell proliferation. Our results show the crucial role that YY1 plays in regulating broad general processes throughout all stages of B-cell differentiation. PMID:27335461

  13. Intrinsic and extrinsic factors influencing the clinical course of B-cell chronic lymphocytic leukemia: prognostic markers with pathogenetic relevance

    Directory of Open Access Journals (Sweden)

    Gaidano Gianluca

    2009-08-01

    Full Text Available Abstract B-cell chronic lymphocytic leukemia (CLL, the most frequent leukemia in the Western world, is characterized by extremely variable clinical courses with survivals ranging from 1 to more than 15 years. The pathogenetic factors playing a key role in defining the biological features of CLL cells, hence eventually influencing the clinical aggressiveness of the disease, are here divided into "intrinsic factors", mainly genomic alterations of CLL cells, and "extrinsic factors", responsible for direct microenvironmental interactions of CLL cells; the latter group includes interactions of CLL cells occurring via the surface B cell receptor (BCR and dependent to specific molecular features of the BCR itself and/or to the presence of the BCR-associated molecule ZAP-70, or via other non-BCR-dependent interactions, e.g. specific receptor/ligand interactions, such as CD38/CD31 or CD49d/VCAM-1. A putative final model, discussing the pathogenesis and the clinicobiological features of CLL in relationship of these factors, is also provided.

  14. Genetic features of B-cell chronic lymphocytic leukemia.

    Science.gov (United States)

    Stilgenbauer, S; Lichter, P; Döhner, H

    2000-03-01

    The genetic features of B-cell chronic lymphocytic leukemia (CLL) are currently being reassessed by molecular cytogenetic techniques such as fluorescence in situ hybridization (FISH). Conventional cytogenetic studies by chromosome banding are difficult in CLL mainly because of the low in vitro mitotic activity of the tumor cells, which leads to poor quantity and quality of metaphase spreads. Molecular genetic analyses are limited because candidate genes are known for only a few chromosomal aberrations that are observed in CLL. FISH was found to be a powerful tool for the genetic analysis of CLL as it overcomes both the low mitotic activity of the CLL cells and the lack of suitable candidate genes for analysis. Using FISH, the detection of chromosomal aberrations can be performed at the single cell level in both dividing and non-dividing cells, thus circumventing the need of metaphase preparations from tumor cells. Probes for the detection of trisomies, deletions and translocation breakpoints can be applied to the regions of interest with the growing number of clones available from genome-wide libraries. Using the interphase cytogenetic FISH approach with a disease specific set of probes, chromosome aberrations can be found in more than 80% of CLL cases. The most frequently observed abnormalities are losses of chromosomal material, with deletions in band 13q14 being the most common, followed by deletions in 11q22-q23, deletions in 17p13 and deletions in 6q21. The most common gains of chromosomal material are trisomies 12q, 8q and 3q. Translocation breakpoints, in particular involving the immunoglobulin heavy chain locus at 14q32, which are frequently observed in other types of non-Hodgkin's lymphoma, are rare events in CLL. Genes affected by common chromosome aberrations in CLL appear to be p53 in cases with 17p deletion and ataxia telangiectasia mutated (ATM), which is mutated in a subset of cases with 11q22-q23 aberrations. However, for the other frequently

  15. Increased B Regulatory Phenotype in Non-Metastatic Lymph Nodes of Node-Positive Breast Cancer Patients.

    Science.gov (United States)

    Mehdipour, F; Razmkhah, M; Hosseini, A; Bagheri, M; Safaei, A; Talei, A-R; Ghaderi, A

    2016-03-01

    Tumour-draining lymph nodes (TDLNs) are centre in orchestrating the immune responses against cancer. The cellularity and lymphocyte subpopulations change in the process of cancer progression and lymph node involvement. B lymphocyte subsets and their function in breast cancer-draining lymph nodes have not been well elucidated. Here, we studied the influence of tumour metastasis on the frequencies of different B cell subsets including naïve and memory B cells as well as those which are known to be enriched in the regulatory pool in TDLNs of 30 patients with breast cancer. Lymphocytes were obtained from a fresh piece of each lymph node and stained for CD19 and other B cell-associated markers and subjected to flow cytometry. Our investigation revealed that metastatic TDLN showed a significant decrease in active, memory and class-switched B cells while the frequencies of B cells with regulatory phenotypes were not changed. However, CD27(hi) CD25(+) and CD1d(hi) CD5(+) B regulatory subsets significantly increased in non-metastatic lymph nodes (nMLNs) of node-positive patients compared with node-negative patients. Our data provided evidence that in breast cancer, metastasis of tumour to axillary lymph nodes altered B cell populations in favour of resting, inactive and unswitched phenotypes. We assume that the lymphatic involvement may cause an increase in a subset of regulatory B cells in non-metastatic lymph nodes. PMID:26708831

  16. Improved method for linear B-cell epitope prediction using antigen's primary sequence.

    Directory of Open Access Journals (Sweden)

    Harinder Singh

    Full Text Available One of the major challenges in designing a peptide-based vaccine is the identification of antigenic regions in an antigen that can stimulate B-cell's response, also called B-cell epitopes. In the past, several methods have been developed for the prediction of conformational and linear (or continuous B-cell epitopes. However, the existing methods for predicting linear B-cell epitopes are far from perfection. In this study, an attempt has been made to develop an improved method for predicting linear B-cell epitopes. We have retrieved experimentally validated B-cell epitopes as well as non B-cell epitopes from Immune Epitope Database and derived two types of datasets called Lbtope_Variable and Lbtope_Fixed length datasets. The Lbtope_Variable dataset contains 14876 B-cell epitope and 23321 non-epitopes of variable length where as Lbtope_Fixed length dataset contains 12063 B-cell epitopes and 20589 non-epitopes of fixed length. We also evaluated the performance of models on above datasets after removing highly identical peptides from the datasets. In addition, we have derived third dataset Lbtope_Confirm having 1042 epitopes and 1795 non-epitopes where each epitope or non-epitope has been experimentally validated in at least two studies. A number of models have been developed to discriminate epitopes and non-epitopes using different machine-learning techniques like Support Vector Machine, and K-Nearest Neighbor. We achieved accuracy from ∼54% to 86% using diverse s features like binary profile, dipeptide composition, AAP (amino acid pair profile. In this study, for the first time experimentally validated non B-cell epitopes have been used for developing method for predicting linear B-cell epitopes. In previous studies, random peptides have been used as non B-cell epitopes. In order to provide service to scientific community, a web server LBtope has been developed for predicting and designing B-cell epitopes (http://crdd.osdd.net/raghava/lbtope/.

  17. Immunotherapy for B-cell lymphoma: current status and prospective advances.

    Science.gov (United States)

    Hollander, Nurit

    2012-01-01

    Therapy for non-Hodgkin's lymphoma has progressed significantly over the last decades. However, the majority of patients remain incurable, and novel therapies are needed. Because immunotherapy ideally offers target selectivity, an ever increasing number of immunotherapies, both passive and active, are undergoing development. The champion of passive immunotherapy to date is the anti-CD20 monoclonal antibody rituximab that revolutionized the standard of care for lymphoma. The great success of rituximab catalyzed the development of new passive immunotherapy strategies that are currently undergoing clinical evaluation. These include improvement of rituximab efficacy, newer generation anti-CD20 antibodies, drug-conjugated and radio labeled anti-CD20 antibodies, monoclonal antibodies targeting non-CD20 lymphoma antigens, and bispecific antibodies. Active immunotherapy aims at inducing long-lasting antitumor immunity, thereby limiting the likelihood of relapse. Current clinical studies of active immunotherapy for lymphoma consist largely of vaccination and immune checkpoint blockade. A variety of protein- and cell-based vaccines are being tested in ongoing clinical studies. Recently completed phase III clinical trials of an idiotype protein vaccine suggest that the vaccine may have clinical activity in a subset of patients. Efforts to enhance the efficacy of active immunotherapy are ongoing with an emphasis on optimization of antigen delivery and presentation of vaccines and modulation of the immune system toward counteracting immunosuppression, using antibodies against immune regulatory checkpoints. This article discusses results of the various immunotherapy approaches applied to date for B-cell lymphoma and the ongoing trials to improve their effect. PMID:22566889

  18. Immunotherapy for B-cell lymphoma: current status and prospective advances

    Directory of Open Access Journals (Sweden)

    Nurit eHollander

    2012-01-01

    Full Text Available Therapy for non-Hodgkin's lymphoma has progressed significantly over the last decades. However, the majority of patients remain incurable, and novel therapies are needed. Because immunotherapy ideally offers target selectivity, an ever increasing number of immunotherapies, both passive and active, are undergoing development. The champion of passive immunotherapy to date is the anti-CD20 monoclonal antibody rituximab that revolutionized the standard of care for lymphoma. The great success of rituximab catalyzed the development of new passive immunotherapy strategies that are currently undergoing clinical evaluation. These include improvement of rituximab efficacy, newer generation anti-CD20 antibodies, drug-conjugated and radiolabelled anti-CD20 antibodies, monoclonal antibodies targeting non-CD20 lymphoma antigens, and bispecific antibodies. Active immunotherapy aims at inducing long-lasting antitumor immunity, thereby limiting the likelihood of relapse. Current clinical studies of active immunotherapy for lymphoma consist largely of vaccination and immune checkpoint blockade. A variety of protein- and cell-based vaccines are being tested in ongoing clinical studies. Recently completed phase III clinical trials of an idiotype protein vaccine suggest that the vaccine may have clinical activity in a subset of patients. Efforts to enhance the efficacy of active immunotherapy are ongoing with an emphasis on optimization of antigen delivery and presentation of vaccines and modulation of the immune system toward counteracting immunosuppression, using antibodies against immune regulatory checkpoints. This article discusses results of the various immunotherapy approaches applied to date for B-cell lymphoma and the ongoing trials to improve their effect.

  19. Enumerating molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Donald Patrick, Jr. (, . Tennessee Technological University, Cookeville, TN); Faulon, Jean-Loup Michel; Roe, Diana C.

    2004-04-01

    This report is a comprehensive review of the field of molecular enumeration from early isomer counting theories to evolutionary algorithms that design molecules in silico. The core of the review is a detail account on how molecules are counted, enumerated, and sampled. The practical applications of molecular enumeration are also reviewed for chemical information, structure elucidation, molecular design, and combinatorial library design purposes. This review is to appear as a chapter in Reviews in Computational Chemistry volume 21 edited by Kenny B. Lipkowitz.

  20. Co-stimulation with TLR7/8 and TLR9 agonists induce down-regulation of innate immune responses in sheep blood mononuclear and B cells.

    Science.gov (United States)

    Booth, Jayaum S; Buza, Joram J; Potter, Andrew; Babiuk, Lorne A; Mutwiri, George K

    2010-05-01

    Toll-like receptors (TLRs) play an important role in the activation of innate and adaptive immune responses. Stimulation with multiple TLR agonists may result in synergistic, complimentary or inhibitory effects on innate immune responses. In this study, we investigated the effects of co-stimulation of sheep peripheral blood mononuclear cells (PBMC) and B cells with agonists for TLR3, 4, 7/8 and 9. Sheep PBMC stimulated with either CpG (TLR9 agonist) or RNA oligoribonucleotides ([ORNs], TLR7/8 agonist) exhibited significant IL-12 production, but only CpG induced IFNalpha, IgM and proliferative responses. In contrast, poly(I:C) (TLR3 agonist) and LPS (TLR4 agonist) did not induce any of these responses. Interestingly, we observed that co-stimulation of PBMC with CpG+ORN or CpG+imiquimod (another TLR7/8 agonist) resulted in significant reduction in CpG-induced IFNalpha production, B cell proliferation and IgM responses. Pre-incubation of cells with CpG prior to exposure of the cells to imiquimod resulted in similar inhibitory responses indicating that the down-regulatory mechanisms are not associated with competition for cellular uptake or for receptors of the two agonists. Sheep B cells constitutively expressed TLR7, TLR8 and TLR9 mRNA transcripts, suggesting a possible role of TLR cross-talk in the down-regulatory mechanisms. Down-regulation of responses by co-stimulation with closely related TLRs may be a regulatory mechanism by which the host prevents overstimulation of innate immune responses. PMID:20051250

  1. ICAM-1-based rabies virus vaccine shows increased infection and activation of primary murine B cells in vitro and enhanced antibody titers in-vivo.

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    James E Norton

    Full Text Available We have previously shown that live-attenuated rabies virus (RABV-based vaccines infect and directly activate murine and human primary B cells in-vitro, which we propose can be exploited to help develop a single-dose RABV-based vaccine. Here we report on a novel approach to utilize the binding of Intracellular Adhesion Molecule-1 (ICAM-1 to its binding partner, Lymphocyte Function-associated Antigen-1 (LFA-1, on B cells to enhance B cell activation and RABV-specific antibody responses. We used a reverse genetics approach to clone, recover, and characterize a live-attenuated recombinant RABV-based vaccine expressing the murine Icam1 gene (rRABV-mICAM-1. We show that the murine ICAM-1 gene product is incorporated into virus particles, potentially exposing ICAM-1 to extracellular binding partners. While rRABV-mICAM-1 showed 10-100-fold decrease in viral titers on baby hamster kidney cells compared to the parental virus (rRABV, rRABV-mICAM-1 infected and activated primary murine B cells in-vitro more efficiently than rRABV, as indicated by significant upregulation of CD69, CD40, and MHCII on the surface of infected B cells. ICAM-1 expression on the virus surface was responsible for enhanced B cell infection since pre-treating rRABV-mICAM-1 with a neutralizing anti-ICAM-1 antibody reduced B cell infection to levels observed with rRABV alone. Furthermore, 100-fold less rRABV-mICAM-1 was needed to induce antibody titers in immunized mice equivalent to antibody titers observed in rRABV-immunized mice. Of note, only 10(3 focus forming units (ffu/mouse of rRABV-mICAM-1 was needed to induce significant anti-RABV antibody titers as early as five days post-immunization. As both speed and potency of antibody responses are important in controlling human RABV infection in a post-exposure setting, these data show that expression of Icam1 from the RABV genome, which is then incorporated into the virus particle, is a promising strategy for the development of a

  2. Expansion of IgG+ B-cells during mitogen stimulation for memory B-cell ELISpot analysis is influenced by size and composition of the B-cell pool

    NARCIS (Netherlands)

    Scholzen, A.; Nahrendorf, W.; Langhorne, J.; Sauerwein, R.W.

    2014-01-01

    The memory B-cell (MBC) ELISpot assay is the main technique used to measure antigen-specific MBCs as a readout of humoral immune memory. This assay relies on the ability of MBCs to differentiate into antibody-secreting cells (ASC) upon polyclonal stimulation. The total number of IgG+ ASCs generated

  3. 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

    cells. How many virgin B cells eventually give rise to the total Ab response to a simple Ag is a fundamental immunologic question. In this report, we address this question in human adults by analyzing the rearranged VkappaJkappa genes of B cells responding to a single dose of the capsular polysaccharide......Restricted V region diversity is a key feature of Abs to many haptens and simple polysaccharides. Two possible mechanisms exist: 1) selection of many clonally unrelated B cells using very similar or identical VDJ and VJ rearrangements; and 2) selection of a heavily expanded progeny of few virgin B...... 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...

  4. Exosomes released from Mycoplasma infected tumor cells activate inhibitory B cells.

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    Chenjie Yang

    Full Text Available Mycoplasmas cause numerous human diseases and are common opportunistic pathogens in cancer patients and immunocompromised individuals. Mycoplasma infection elicits various host immune responses. Here we demonstrate that mycoplasma-infected tumor cells release exosomes (myco+ exosomes that specifically activate splenic B cells and induce splenocytes cytokine production. Induction of cytokines, including the proinflammatory IFN-γ and the anti-inflammatory IL-10, was largely dependent on the presence of B cells. B cells were the major IL-10 producers. In splenocytes from B cell deficient μMT mice, induction of IFN-γ+ T cells by myco+ exosomes was greatly increased compared with wild type splenocytes. In addition, anti-CD3-stimulated T cell proliferation was greatly inhibited in the presence of myco+ exosome-treated B cells. Also, anti-CD3-stimulated T cell signaling was impaired by myco+ exosome treatment. Proteomic analysis identified mycoplasma proteins in exosomes that potentially contribute to the effects. Our results demonstrate that mycoplasma-infected tumor cells release exosomes carrying mycoplasma components that preferentially activate B cells, which in turn, are able to inhibit T cell activity. These results suggest that mycoplasmas infecting tumor cells can exploit the exosome pathway to disseminate their own components and modulate the activity of immune cells, in particular, activate B cells with inhibitory activity.

  5. Kinetic modeling reveals a common death niche for newly formed and mature B cells.

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    Gitit Shahaf

    Full Text Available BACKGROUND: B lymphocytes are subject to elimination following strong BCR ligation in the absence of appropriate second signals, and this mechanism mediates substantial cell losses during late differentiation steps in the bone marrow and periphery. Mature B cells may also be eliminated through this mechanism as well as through normal turnover, but the population containing mature cells destined for elimination has not been identified. Herein, we asked whether the transitional 3 (T3 subset, which contains most newly formed cells undergoing anergic death, could also include mature B cells destined for elimination. METHODOLOGY/PRINCIPAL FINDINGS: To interrogate this hypothesis and its implications, we applied mathematical models to previously generated in vivo labeling data. Our analyses reveal that the death rate of T3 B cells is far higher than the death rates of all other splenic B cell subpopulations. Further, the model, in which the T3 pool includes both newly formed and mature primary B cells destined for apoptotic death, shows that this cell loss may account for nearly all mature B cell turnover. CONCLUSIONS/SIGNIFICANCE: This finding has implications for the mechanism of normal mature B cell turnover.

  6. Pro-B-cell-specific transcription and proapoptotic function of protein kinase Ceta.

    Science.gov (United States)

    Morrow, T A; Muljo, S A; Zhang, J; Hardwick, J M; Schlissel, M S

    1999-08-01

    Using a subtractive cloning scheme on cDNA prepared from primary pro-B and pre-B cells, we identified several genes whose products regulate apoptosis. We further characterized one of these genes, encoding protein kinase Ceta (PKCeta). PKCeta transcripts were readily detected in pro-B cells but were absent in pre-B cells. Although both a full-length and a truncated form of PKCeta were detectable in bone marrow pro-B cells, transition to the pre-B-cell stage was associated with increased relative levels of truncated PKCeta. We found that PKCeta is proteolyzed in apoptotic lymphocytes, generating a kinase-active fragment identical to the truncated form which is capable of inducing apoptosis when expressed in a pro-B cell line. Caspase-3 can generate an identical PKCeta cleavage product in vitro, and caspase inhibitors prevent the generation of this product during apoptosis in transfected cell lines. Inducible overexpression of either the full-length or truncated form of PKCeta results in cell cycle arrest at the G(1)/S transition. These results suggest that the expression and proteolytic activation of PKCeta play an important role in the regulation of cell division and cell death during early B-cell development. PMID:10409750

  7. Morphologic and Functional Effects of Gamma Secretase Inhibition on Splenic Marginal Zone B Cells

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    Maria Cristina de Vera Mudry

    2012-01-01

    Full Text Available The γ-secretase complex is a promising target in Alzheimer’s disease because of its role in the amyloidogenic processing of β-amyloid precursor protein. This enzyme also catalyzes the cleavage of Notch receptor, resulting in the nuclear translocation of intracellular Notch where it modulates gene transcription. Notch signaling is essential in cell fate decisions during embryogenesis, neuronal differentiation, hematopoiesis, and development of T and B cells, including splenic marginal zone (MZ B cells. This B cell compartment participates in the early phases of the immune response to blood-borne bacteria and viruses. Chronic treatment with the oral γ-secretase inhibitor RO4929097 resulted in dose-dependent decreased cellularity (atrophy of the MZ of rats and mice. Significant decreases in relative MZ B-cell numbers of RO4929097-treated animals were confirmed by flow cytometry. Numbers of MZ B cells reverted to normal after a sufficient RO4929097-free recovery period. Functional characterization of the immune response in relation to RO4929097-related MZ B cell decrease was assessed in mice vaccinated with inactivated vesicular stomatitis virus (VSV. Compared with the immunosuppressant cyclosporin A, RO4929097 caused only mild and reversible delayed early neutralizing IgM and IgG responses to VSV. Thus, the functional consequence of MZ B cell decrease on host defense is comparatively mild.

  8. Expansion of IgG+ B-cells during mitogen stimulation for memory B-cell ELISpot analysis is influenced by size and composition of the B-cell pool.

    Science.gov (United States)

    Scholzen, Anja; Nahrendorf, Wiebke; Langhorne, Jean; Sauerwein, Robert W

    2014-01-01

    The memory B-cell (MBC) ELISpot assay is the main technique used to measure antigen-specific MBCs as a readout of humoral immune memory. This assay relies on the ability of MBCs to differentiate into antibody-secreting cells (ASC) upon polyclonal stimulation. The total number of IgG+ ASCs generated by mitogen-stimulation is often used as a reference point; alternatively antigen-specific MBCs are expressed as a frequency of post-culture peripheral blood mononuclear cells (PBMC) as a surrogate for absolute frequencies. Therefore, it is important to know whether IgG+ B-cells are uniformly expanded during the preceding mitogen-culture as a true reflection of MBC frequencies ex vivo. We systematically compared B-cell phenotype and proportions before and after mitogen stimulation in cultures of 269 peripheral blood mononuclear cell samples from 62 volunteers by flow cytometry and analyzed the number of resulting ASCs. Our data show that the number of total IgG+ ASCs detected by ELISpot after mitogen stimulation correlates with the proportion of IgG+ MBCs ex vivo, highlighting its general robustness for comparisons of study cohorts at group level. The expansion of total and IgG+ B-cells during mitogen-stimulation, however, was not identical in all cultures, but influenced by size and composition of the ex vivo B-cell compartment. The uncorrected readout of antigen-specific MBCs per million post-culture PBMCs therefore only preserves the quality, but not the magnitude of differences in the ex vivo MBC response between groups or time points, particularly when comparing samples where the B-cell compartment substantially differs between cohorts or over time. Therefore, expressing antigen-specific cells per total IgG+ ASCs is currently the best measure to correct for mitogen-culture effects. Additionally, baseline information on the size and composition of the ex vivo B-cell compartment should be supplied to additionally inform about differences or changes in the size and

  9. Expansion of IgG+ B-cells during mitogen stimulation for memory B-cell ELISpot analysis is influenced by size and composition of the B-cell pool.

    Directory of Open Access Journals (Sweden)

    Anja Scholzen

    Full Text Available The memory B-cell (MBC ELISpot assay is the main technique used to measure antigen-specific MBCs as a readout of humoral immune memory. This assay relies on the ability of MBCs to differentiate into antibody-secreting cells (ASC upon polyclonal stimulation. The total number of IgG+ ASCs generated by mitogen-stimulation is often used as a reference point; alternatively antigen-specific MBCs are expressed as a frequency of post-culture peripheral blood mononuclear cells (PBMC as a surrogate for absolute frequencies. Therefore, it is important to know whether IgG+ B-cells are uniformly expanded during the preceding mitogen-culture as a true reflection of MBC frequencies ex vivo. We systematically compared B-cell phenotype and proportions before and after mitogen stimulation in cultures of 269 peripheral blood mononuclear cell samples from 62 volunteers by flow cytometry and analyzed the number of resulting ASCs. Our data show that the number of total IgG+ ASCs detected by ELISpot after mitogen stimulation correlates with the proportion of IgG+ MBCs ex vivo, highlighting its general robustness for comparisons of study cohorts at group level. The expansion of total and IgG+ B-cells during mitogen-stimulation, however, was not identical in all cultures, but influenced by size and composition of the ex vivo B-cell compartment. The uncorrected readout of antigen-specific MBCs per million post-culture PBMCs therefore only preserves the quality, but not the magnitude of differences in the ex vivo MBC response between groups or time points, particularly when comparing samples where the B-cell compartment substantially differs between cohorts or over time. Therefore, expressing antigen-specific cells per total IgG+ ASCs is currently the best measure to correct for mitogen-culture effects. Additionally, baseline information on the size and composition of the ex vivo B-cell compartment should be supplied to additionally inform about differences or changes in

  10. CD80 and CD86 differentially regulate mechanical interactions of T-cells with antigen-presenting dendritic cells and B-cells.

    Science.gov (United States)

    Lim, Tong Seng; Goh, James Kang Hao; Mortellaro, Alessandra; Lim, Chwee Teck; Hämmerling, Günter J; Ricciardi-Castagnoli, Paola

    2012-01-01

    Functional T-cell responses are initiated by physical interactions between T-cells and antigen-presenting cells (APCs), including dendritic cells (DCs) and B-cells. T-cells are activated more effectively by DCs than by B-cells, but little is known about the key molecular mechanisms that underpin the particular potency of DC in triggering T-cell responses. To better understand the influence of physical intercellular interactions on APC efficacy in activating T-cells, we used single cell force spectroscopy to characterize and compare the mechanical forces of interactions between DC:T-cells and B:T-cells. Following antigen stimulation, intercellular interactions of DC:T-cell conjugates were stronger than B:T-cell interactions. DCs induced higher levels of T-cell calcium mobilization and production of IL-2 and IFNγ than were elicited by B-cells, thus suggesting that tight intercellular contacts are important in providing mechanically stable environment to initiate T-cell activation. Blocking antibodies targeting surface co-stimulatory molecules CD80 or CD86 weakened intercellular interactions and dampen T-cell activation, highlighting the amplificatory roles of CD80/86 in regulating APC:T-cell interactions and T-cell functional activation. The variable strength of mechanical forces between DC:T-cells and B:T-cell interactions were not solely dependent on differential APC expression of CD80/86, since DCs were superior to B-cells in promoting strong interactions with T-cells even when CD80 and CD86 were inhibited. These data provide mechanical insights into the effects of co-stimulatory molecules in regulating APC:T-cell interactions. PMID:23024807

  11. CD80 and CD86 differentially regulate mechanical interactions of T-cells with antigen-presenting dendritic cells and B-cells.

    Directory of Open Access Journals (Sweden)

    Tong Seng Lim

    Full Text Available Functional T-cell responses are initiated by physical interactions between T-cells and antigen-presenting cells (APCs, including dendritic cells (DCs and B-cells. T-cells are activated more effectively by DCs than by B-cells, but little is known about the key molecular mechanisms that underpin the particular potency of DC in triggering T-cell responses. To better understand the influence of physical intercellular interactions on APC efficacy in activating T-cells, we used single cell force spectroscopy to characterize and compare the mechanical forces of interactions between DC:T-cells and B:T-cells. Following antigen stimulation, intercellular interactions of DC:T-cell conjugates were stronger than B:T-cell interactions. DCs induced higher levels of T-cell calcium mobilization and production of IL-2 and IFNγ than were elicited by B-cells, thus suggesting that tight intercellular contacts are important in providing mechanically stable environment to initiate T-cell activation. Blocking antibodies targeting surface co-stimulatory molecules CD80 or CD86 weakened intercellular interactions and dampen T-cell activation, highlighting the amplificatory roles of CD80/86 in regulating APC:T-cell interactions and T-cell functional activation. The variable strength of mechanical forces between DC:T-cells and B:T-cell interactions were not solely dependent on differential APC expression of CD80/86, since DCs were superior to B-cells in promoting strong interactions with T-cells even when CD80 and CD86 were inhibited. These data provide mechanical insights into the effects of co-stimulatory molecules in regulating APC:T-cell interactions.

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

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    Chaohong Liu

    2013-11-01

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

  13. 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. PMID:18611066

  14. 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.

  15. 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. PMID:26500142

  16. Germinal center B cell depletion diminishes CD4+ follicular T helper cells in autoimmune mice.

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    Isharat Yusuf

    Full Text Available BACKGROUND: Continuous support from follicular CD4(+ T helper (Tfh cells drives germinal center (GC responses, which last for several weeks to produce high affinity memory B cells and plasma cells. In autoimmune Sle1 and NZB/W F1 mice, elevated numbers of Tfh cells persist, promoting the expansion of self-reactive B cells. Expansion of circulating Tfh like cells have also been described in several autoimmune diseases. Although, the signals required for Tfh differentiation have now been well described, the mechanisms that sustain the maintenance of fully differentiated Tfh are less understood. Recent data demonstrate a role for GC B cells for Tfh maintenance after protein immunization. METHODS AND FINDING: Given the pathogenic role Tfh play in autoimmune disease, we explored whether B cells are required for maintenance of autoreactive Tfh. Our data suggest that the number of mature autoreactive Tfh cells is controlled by GC B cells. Depletion of B cells in Sle1 autoimmune mice leads to a dramatic reduction in Tfh cells. In NZB/W F1 autoimmune mice, similar to the SRBC immunization model, GC B cells support the maintenance of mature Tfh, which is dependent mainly on ICOS. The CD28-associated pathway is dispensable for Tfh maintenance in SRBC immunized mice, but is required in the spontaneous NZB/W F1 model. CONCLUSION: These data suggest that mature Tfh cells require signals from GC B cells to sustain their optimal numbers and function in both autoimmune and immunization models. Thus, immunotherapies targeting B cells in autoimmune disease may affect pathogenic Tfh cells.

  17. Molecular characterization and T and B cell epitopes prediction of Mycoplasma synoviae 53 strain VlhA hemagglutinin

    Directory of Open Access Journals (Sweden)

    Ilana Lopes Camargo

    2007-01-01

    Full Text Available Mycoplasma sinoviae is a major pathogen of poultry causing synovitis and respiratory infection. M. synoviae hemagglutinin (VlhA is a lipoprotein encoded by related multigene families that appear to have arisen by horizontal gene transfer. It is an abundant immunodominant surface protein involved in host-parasite interaction mediating binding to host erythrocytes. Herein, we have performed in silico analysis of the vlhA gene product from the Mycoplasma synoviae 53 strain and compared it to the VlhA protein of M. synoviae WUV1853 strain. The VlhA of the M. synoviae 53 strain possesses 569 amino acids and showed 85% identity with the VlhA protein of the M. synoviae WUV1853 strain. Further, a signal peptide was identified from amino acid M1 to D28 and a cleavage site between D28 and Q29, both located in the N-terminal domain of the molecule. Additionally, an insertion of PAPT amino acids was observed between T30-P35 and a deletion of the amino acids GTPGNP within the PRR region of the VlhA from the M. synoviae 53 strain, which may be related to its reduced virulence. Finally, we have identified 17 B cell epitopes and 22 T cells epitopes within the VlhA from the M. synoviae 53 strain. The B cell epitope S263-D277 and the T cell epitopes N45-N54 and G58-N67 showed 100% and 87-100% identity, respectively, with regions of VlhA protein of tested Mycoplasma synoviae and Mycoplasma galisepticum strains. Thus, these peptides represent new candidate molecules for the development of efficient diagnostic assays and new subunit vaccines.

  18. Epstein-Barr virus positive B-cell lymphoproliferative disorder/polymorphous B-cell lymphoma of the urinary bladder: A case report with review of literature

    OpenAIRE

    Sundaram, Sandhya; Zhang, Kai

    2009-01-01

    We report an unusual case of a localized Epstein-Barr virus (EBV)-positive B cell lymphoproliferative disorder (LPD)/polymorphous B cell lymphoma of the urinary bladder in a 67 years old female patient. She had no known predisposing immunodeficiencies and presented with recent onset of hematuria. The CT and cystoscopic examination revealed a localized 2.5 cm polypoid or plaque-like mucosal mass on the right posterior and lateral wall of the bladder. The biopsy sample showed a diffuse and dens...

  19. Monoclonal B-cell hyperplasia and leukocyte imbalance precede development of B-cell malignancies in uracil-DNA glycosylase deficient mice

    DEFF Research Database (Denmark)

    Andersen, Sonja; Ericsson, Madelene; Dai, Hong Yan;

    2005-01-01

    Ung-deficient mice have reduced class switch recombination, skewed somatic hypermutation, lymphatic hyperplasia and a 22-fold increased risk of developing B-cell lymphomas. We find that lymphomas are of follicular (FL) and diffuse large B-cell type (DLBCL). All FLs and 75% of the DLBCLs were...... interleukin 2 is clearly different in wild type and in Ung-deficient mice. This suggests that Ung-proteins, directly or indirectly, have important functions in the immune system, not only in the process of antibody maturation, but also for production and functions of immunologically important cell types. The...

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    OBJECTIVE: Hierarchical clusterings of diffuse large B-cell lymphoma (DLBCL) based on gene expression signatures have previously been used to classify DLBCL into Germinal Center B-cell (GCB) and Activated B-cell (ABC) types. To examine if it was feasible to perform a cross-platform validation on...... of classifier genes was generated by analysis of 34 patients that were consistently classified as GCB or ABC in the above analyses. Seventy-eight genes were selected and demonstrated on two previously published data sets (Shipp et al. Nat Med 2002;8:68-74 and Houldsworth et al. Blood 2004...

  1. Kinetic Analysis of CpG-Induced Mouse B Cell Growth and Ig Production

    OpenAIRE

    Kim, Young-Ha; Lee, Sang-Hoon; Yoo, Yung-Choon; Lee, Junglim; Park, Jong-Hwan; Park, Seok-Rae

    2012-01-01

    Immune cells express toll-like receptors (TLRs) and respond to molecular patterns of various pathogens. CpG motif in bacterial DNA activates innate and acquired immune systems through binding to TLR9 of immune cells. Several studies reported that CpG can directly regulate B cell activation, differentiation, and Ig production. However, the role of CpG in B cell growth and Ig production is not fully understood. In this study, we analyzed the effect of CpG on the kinetics of mouse B cell viabili...

  2. Comprehensive Assessment and Classification of High-Grade B-cell Lymphomas.

    Science.gov (United States)

    Behdad, Amir; Bailey, Nathanael G

    2016-03-01

    High-grade B-cell lymphomas (HGBCLs) are a heterogeneous group of neoplasms that include subsets of diffuse large B-cell lymphoma, Burkitt lymphoma, and lymphomas with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma. Morphologically indistinguishable HGBCLs may demonstrate variable clinical courses and responses to therapy. The morphologic evaluation and classification of these neoplasms must be followed by further genetic and immunophenotypic work-up. These additional diagnostic modalities lead to a comprehensive stratification of HGBCL that determines the prognosis and optimal therapy. This article reviews the well-established and emerging biomarkers that are most relevant to the clinical management of HGBCL. PMID:26940267

  3. Raji B cells, misidentified as THP-1 cells, stimulate DC-SIGN-mediated HIV transmission

    International Nuclear Information System (INIS)

    A number of studies examining interactions of dendritic cell (DC)-specific ICAM-3 grabbing nonintegrin (DC-SIGN) with viral pathogens have relied on monocytic transfectants as models for primary DCs. Here we show that the presumed 'THP-1' monocytic cells used in these studies are instead Raji B cells. Moreover, we demonstrate that true THP-1 cells do not support DC-SIGN-mediated HIV-1 transmission, whereas human B cell lines efficiently enhance this process. These data indicate that there are features common to B cells and DCs that facilitate transmission of HIV-1 and provide new insights toward the mechanism of DC-SIGN-mediated HIV-1 transmission

  4. Improved Method for Linear B-Cell Epitope Prediction Using Antigen’s Primary Sequence

    OpenAIRE

    Singh, Harinder; Ansari, Hifzur Rahman; Gajendra P. S. Raghava

    2013-01-01

    One of the major challenges in designing a peptide-based vaccine is the identification of antigenic regions in an antigen that can stimulate B-cell’s response, also called B-cell epitopes. In the past, several methods have been developed for the prediction of conformational and linear (or continuous) B-cell epitopes. However, the existing methods for predicting linear B-cell epitopes are far from perfection. In this study, an attempt has been made to develop an improved method for predicting ...

  5. Treatment of B-cells non-Hodgkin lymphomas with combined immunochemotherapy: ability to treatment optimization

    OpenAIRE

    Smirnova, N. V.; N. V. Myakova; M. B. Belogurova; O. V. Ryskal; O. E. Nikonova; G. R. Sharapova; A. S. Fedorova; N. A. Grigorieva; A. V. Shamardina; N. I. Ponomareva; D. S. Abramov; D. M. Konovalov; M. E. Dubrovina; A. A. Maschan; E. V. Samochatova

    2015-01-01

    The results of two consecutive multicenter clinical trials enrolled 241 patient with childhood mature B-cells non-Hodgkin lymphomas/leukemia are presented. Patients received treatment according B-NHL 2004mab protocol (n = 83) and B-NHL 2010M (n = 158) with combined immunochemotherapy (ICT) in Russian and Belarus pediatric clinics from 2004 to 2015 years. Primary patients with different mature B-NHL (Burkitt lymphoma/leukemia, diffuse large B-cell lymphoma and primary mediastinal B-cell lympho...

  6. B-Cell Activation and Non-Hodgkin Lymphoma Risk in an HIV Positive Population

    OpenAIRE

    Chang, Po-Yin

    2013-01-01

    Background: B-cell non-Hodgkin lymphoma (NHL) in HIV populations (AIDS-NHL) has become the leading cause of AIDS-defining cancers. Studies suggested that genetic or serum markers of B-cell activation are related to AIDS-NHL. However, associations between HIV viral load and AIDS-NHL risk have not been explicitly explored with consideration of B-cell activation markers. Furthermore, associations of hepatitis C virus (HCV) infection to AIDS-NHL risk are inconclusive. Methods: We used two nested ...

  7. Defective nonhomologous end joining blocks B-cell development in FLT3/ITD mice

    OpenAIRE

    Li, Li; Zhang, Li; Fan, Jinshui; Greenberg, Kathleen; Desiderio, Stephen; Rassool, Feyruz V.; Small, Donald

    2011-01-01

    We have generated an FLT3/ITD knock-in mouse model in which mice with an FLT3/ITD mutation develop myeloproliferative disease (MPD) and a block in early B-lymphocyte development. To elucidate the role of FLT3/ITD signaling in B-cell development, we studied VDJ recombination in the pro-B cells of FLT3/ITD mice and discovered an increased frequency of DNA double strand breaks (DSBs) introduced by the VDJ recombinase. Early pro-B cells from FLT3/ITD mice were found to have a lower efficiency and...

  8. Rationale for targeting the pre-B-cell receptor signaling pathway in acute lymphoblastic leukemia.

    Science.gov (United States)

    Müschen, Markus

    2015-06-11

    Inhibitors of B-cell receptor (BCR) and pre-BCR signaling were successfully introduced into patient care for various subtypes of mature B-cell lymphoma (e.g., ibrutinib, idelalisib). Acute lymphoblastic leukemia (ALL) typically originates from pre-B cells that critically depend on survival signals emanating from a functional pre-BCR. However, whether patients with ALL benefit from treatment with (pre-) BCR inhibitors has not been explored. Recent data suggest that the pre-BCR functions as tumor suppressor in the majority of cases of human ALL. However, a distinct subset of human ALL is selectively sensitive to pre-BCR antagonists. PMID:25878119

  9. Regulation of Bach2 by the aryl hydrocarbon receptor as a mechanism for suppression of B-cell differentiation by 2,3,7,8-tetrachlorodibenzo-p-dioxin

    International Nuclear Information System (INIS)

    Exposure to the aryl hydrocarbon receptor (AHR) agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters B-cell differentiation and suppresses antibody production. Previous genomic studies in mouse B cells identified Bach2 as a direct target of the AHR. Bach2 is known to repress expression of Prdm1, a key transcription factor involved in B-cell differentiation, by binding to Maf elements (MAREs) in the regulatory regions of the gene. Chromatin immunoprecipitation followed by quantitative PCR in TCDD-treated lipopolysaccharide (LPS)-activated B cells showed increased binding of the AHR within the first intron in the Bach2 gene. The binding was further confirmed by electrophoretic mobility shift assay (EMSA). TCDD also induced expression of Bach2 in activated as well as resting B cells from 2 to 24 h post-treatment in a time- and concentration-dependent manner. Expression of Prdm1 was decreased by TCDD at 24 h and was consistent with repression by Bach2. Increased DNA binding activity to the intron 5 MARE with increasing TCDD concentrations was observed by EMSA. Supershifts identified the presence of Bach2 in the DNA binding complex associated with the intron 5 MARE of Prdm1. Functional validation of the role of Bach2 in the suppression of B-cell differentiation by TCDD was performed using RNA interference (RNAi). Knockdown of Bach2 showed approximately 40% reversal in the TCDD-induced suppression of IgM secretion when compared to controls. The results suggest that the transcriptional regulation of Bach2 by the AHR is one of the mechanisms involved in the suppression of B-cell differentiation by TCDD.

  10. Functional screening identifies CRLF2 in precursor B-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Yoda, Akinori; Yoda, Yuka; Chiaretti, Sabina; Bar-Natan, Michal; Mani, Kartik; Rodig, Scott J; West, Nathan; Xiao, Yun; Brown, Jennifer R; Mitsiades, Constantine; Sattler, Martin; Kutok, Jeffrey L; DeAngelo, Daniel J; Wadleigh, Martha; Piciocchi, Alfonso; Dal Cin, Paola; Bradner, James E; Griffin, James D; Anderson, Kenneth C; Stone, Richard M; Ritz, Jerome; Foà, Robin; Aster, Jon C; Frank, David A; Weinstock, David M

    2010-01-01

    The prognosis for adults with precursor B-cell acute lymphoblastic leukemia (B-ALL) remains poor, in part from a lack of therapeutic targets. We identified the type I cytokine receptor subunit CRLF2 in a functional screen for B-ALL-derived mRNA transcripts that can substitute for IL3 signaling. We demonstrate that CRLF2 is overexpressed in approximately 15% of adult and high-risk pediatric B-ALL that lack MLL, TCF3, TEL, and BCR/ABL rearrangements, but not in B-ALL with these rearrangements or other lymphoid malignancies. CRLF2 overexpression can result from translocation with the IGH locus or intrachromosomal deletion and is associated with poor outcome. CRLF2 overexpressing B-ALLs share a transcriptional signature that significantly overlaps with a BCR/ABL signature, and is enriched for genes involved in cytokine receptor and JAK-STAT signaling. In a subset of cases, CRLF2 harbors a Phe232Cys gain-of-function mutation that promotes constitutive dimerization and cytokine independent growth. A mutually exclusive subset harbors activating mutations in JAK2. In fact, all 22 B-ALLs with mutant JAK2 that we analyzed overexpress CRLF2, distinguishing CRLF2 as the key scaffold for mutant JAK2 signaling in B-ALL. Expression of WT CRLF2 with mutant JAK2 also promotes cytokine independent growth that, unlike CRLF2 Phe232Cys or ligand-induced signaling by WT CRLF2, is accompanied by JAK2 phosphorylation. Finally, cells dependent on CRLF2 signaling are sensitive to small molecule inhibitors of either JAKs or protein kinase C family kinases. Together, these findings implicate CRLF2 as an important factor in B-ALL with diagnostic, prognostic, and therapeutic implications. PMID:20018760

  11. The Icsbp locus is a common proviral insertion site in mature B-cell lymphomas/plasmacytomas induced by exogenous murine leukemia virus

    International Nuclear Information System (INIS)

    ICSBP (interferon consensus sequence binding protein)/IRF8 (interferon regulatory factor 8) is an interferon gamma-inducible transcription factor expressed predominantly in hematopoietic cells, and down-regulation of this factor has been observed in chronic myelogenous leukemia and acute myeloid leukemia in man. By screening about 1200 murine leukemia virus (MLV)-induced lymphomas, we found proviral insertions at the Icsbp locus in 14 tumors, 13 of which were mature B-cell lymphomas or plasmacytomas. Only one was a T-cell lymphoma, although such tumors constituted about half of the samples screened. This indicates that the Icsbp locus can play a specific role in the development of mature B-lineage malignancies. Two proviral insertions in the last Icsbp exon were found to act by a poly(A)-insertion mechanism. The remaining insertions were found within or outside Icsbp. Since our results showed expression of Icsbp RNA and protein in all end-stage tumor samples, a simple tumor suppressor function of ICSBP is not likely. Interestingly, proviral insertions at Icsbp have not been reported from previous extensive screenings of mature B-cell lymphomas induced by endogenous MLVs. We propose that ICSBP might be involved in an early modulation of an immune response to exogenous MLVs that might also play a role in proliferation of the mature B-cell lymphomas

  12. An adaptive immune response driven by mature, antigen-experienced T and B cells within the microenvironment of oral squamous cell carcinoma.

    Science.gov (United States)

    Quan, Hongzhi; Fang, Liangjuan; Pan, Hao; Deng, Zhiyuan; Gao, Shan; Liu, Ousheng; Wang, Yuehong; Hu, Yanjia; Fang, Xiaodan; Yao, Zhigang; Guo, Feng; Lu, Ruohuang; Xia, Kun; Tang, Zhangui

    2016-06-15

    Lymphocyte infiltrates have been observed in the microenvironment of oral cancer; however, little is known about whether the immune response of the lymphocyte infiltrate affects tumor biology. For a deeper understanding of the role of the infiltrating-lymphocytes in oral squamous cell carcinoma (OSCC), we characterized the lymphocyte infiltrate repertoires and defined their features. Immunohistochemistry revealed considerable T and B cell infiltrates and lymphoid follicles with germinal center-like structures within the tumor microenvironment. Flow cytometry demonstrated that populations of antigen-experienced CD4+ and CD8+ cells were present, as well as an enrichment of regulatory T cells; and T cells expressing programmed death-1 (PD-1) and T cell Ig and mucin protein-3 (Tim-3), indicative of exhaustion, within the tumor microenvironment. Characterization of tumor-infiltrating B cells revealed clear evidence of antigen exposure, in that the cardinal features of an antigen-driven B cell response were present, including somatic mutation, clonal expansion, intraclonal variation and isotype switching. Collectively, our results point to an adaptive immune response occurring within the OSCC microenvironment, which may be sustained by the expression of specific antigens in the tumor. PMID:26815146

  13. Regulatory T and B lymphocytes in a spontaneous autoimmune polyneuropathy.

    Science.gov (United States)

    Quan, S; Sheng, J R; Abraham, P M; Soliven, B

    2016-04-01

    B7-2(-/-) non-obese diabetic (NOD) mice develop a spontaneous autoimmune polyneuropathy (SAP) that mimics the progressive form of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). In this study, we focused on the role of regulatory T cells (Tregs ) and regulatory B cells (Bregs ) in SAP. We found that deletion of B7-2 in female NOD mice led to a lower frequency and number of Tregs and Bregs in spleens and lymph nodes. Tregs but not Bregs suppressed antigen-stimulated splenocyte proliferation, whereas Bregs inhibited the T helper type 1 (Th1) cytokine response. Both Tregs and Bregs induced an increase in CD4(+) interleukin (IL)-10(+) cells, although less effectively in the absence of B7-2. Adoptive transfer studies revealed that Tregs , but not Bregs , suppressed SAP, while Bregs attenuated disease severity when given prior to symptom onset. B cell deficiency in B cell-deficient (muMT)/B7-2(-/-) NOD mice prevented the development of SAP, which would indicate that the pathogenic role of B cells predominates over its regulatory role in this model. We conclude that Bregs and Tregs control the immunopathogenesis and progression of SAP in a non-redundant fashion, and that therapies aimed at expansion of Bregs and Tregs may be an effective approach in autoimmune neuropathies. PMID:26671281

  14. The B-cell identity factor Pax5 regulates distinct transcriptional programmes in early and late B lymphopoiesis

    OpenAIRE

    Revilla-i-Domingo, Roger; Bilic, Ivan; Vilagos, Bojan; Tagoh, Hiromi; Ebert, Anja; Tamir, Ido M.; Smeenk, Leonie; Trupke, Johanna; Sommer, Andreas; Jaritz, Markus; Busslinger, Meinrad

    2012-01-01

    Genome-wide sequencing approaches reveal that the transcription factor Pax5 controls the identity and function of B cells by regulating the expression of distinct target genes in pro-B and mature B cells.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  16. B-cell inhibition by cross-linking CD79b is superior to B-cell depletion with anti-CD20 antibodies in treating murine collagen-induced arthritis

    Czech Academy of Sciences Publication Activity Database

    Bruhl, H.; Cihak, J.; Talke, Y.; Rodriguez-Gomez, M.; Hermann, F.; Goebel, N.; Renner, K.; Plachý, Jiří; Stangassinger, M.; Archemann, S.; Nimmerjahn, F.; Mack, M.

    2015-01-01

    Roč. 45, č. 3 (2015), s. 705-715. ISSN 0014-2980 Institutional support: RVO:68378050 Keywords : Arthritis * B cells * B-cell depletion * B-cell inhibition * CD79b * Humoral immune response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.034, year: 2014

  17. Alisertib and Romidepsin in Treating Patients With Relapsed or Refractory B-Cell or T-Cell Lymphomas

    Science.gov (United States)

    2016-06-15

    Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Mature T- and NK-Cell Non-Hodgkin Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Hodgkin Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Mature T-Cell and NK-Cell Non-Hodgkin Lymphoma

  18. Importance of gallium-67 scintigraphy in primary cutaneous B-cell lymphoma: report of two cases

    International Nuclear Information System (INIS)

    The authors describe two cases of cutaneous B-cell lymphoma where correct staging, treatment and follow-up could be achieved through a combination of conventional imaging studies and gallium-67 scintigraphy. (author)

  19. IgA production requires B cell interaction with subepithelial dendritic cells in Peyer's patches.

    Science.gov (United States)

    Reboldi, Andrea; Arnon, Tal I; Rodda, Lauren B; Atakilit, Amha; Sheppard, Dean; Cyster, Jason G

    2016-05-13

    Immunoglobulin A (IgA) induction primarily occurs in intestinal Peyer's patches (PPs). However, the cellular interactions necessary for IgA class switching are poorly defined. Here we show that in mice, activated B cells use the chemokine receptor CCR6 to access the subepithelial dome (SED) of PPs. There, B cells undergo prolonged interactions with SED dendritic cells (DCs). PP IgA class switching requires innate lymphoid cells, which promote lymphotoxin-β receptor (LTβR)-dependent maintenance of DCs. PP DCs augment IgA production by integrin αvβ8-mediated activation of transforming growth factor-β (TGFβ). In mice where B cells cannot access the SED, IgA responses against oral antigen and gut commensals are impaired. These studies establish the PP SED as a niche supporting DC-B cell interactions needed for TGFβ activation and induction of mucosal IgA responses. PMID:27174992

  20. Is B Cell-Targeted Therapy Effective in Systemic Lupus Erythematosus?

    Science.gov (United States)

    Paran, Daphna; Naparstek, Yaakov

    2015-02-01

    In the past decade we have witnessed a dramatic change in the management of autoimmune diseases, such as rheumatoid arthritis, due to the development of new biologic drugs designed to target key mediators in the autoimmune process. However, the development of similar target-specific drugs for the management of SLE has not been as successful. The B cell has long been considered central to the pathogenesis of SLE and has been regarded as an important target for biologic drugs. Several B cell-targeted drugs have been developed and although the mechanisms seem promising, most of the studies published to date have failed to achieve their primary endpoints, leading to an ongoing debate regarding the role of B cell therapy in SLE. The present report discusses the pros and cons of B cell-targeted therapy in SLE, reviews the clinical studies, and offers possible explanations forthe discrepancies between randomized control studies and real-life experience. PMID:26223085

  1. Phospho-specific flow cytometry identifies aberrant signaling in indolent B-cell lymphoma

    Directory of Open Access Journals (Sweden)

    Blix Egil S

    2012-10-01

    Full Text Available Abstract Background Knowledge about signaling pathways in malignant cells may provide prognostic and diagnostic information in addition to identify potential molecular targets for therapy. B-cell receptor (BCR and co-receptor CD40 signaling is essential for normal B cells, and there is increasing evidence that signaling via BCR and CD40 plays an important role in the pathogenesis of B-cell lymphoma. The aim of this study was to investigate basal and induced signaling in lymphoma B cells and infiltrating T cells in single-cell suspensions of biopsies from small cell lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL and marginal zone lymphoma (MZL patients. Methods Samples from untreated SLL/CLL and MZL patients were examined for basal and activation induced signaling by phospho-specific flow cytometry. A panel of 9 stimulation conditions targeting B and T cells, including crosslinking of the B cell receptor (BCR, CD40 ligand and interleukins in combination with 12 matching phospho-protein readouts was used to study signaling. Results Malignant B cells from SLL/CLL patients had higher basal levels of phosphorylated (p-SFKs, p-PLCγ, p-ERK, p-p38, p-p65 (NF-κB, p-STAT5 and p-STAT6, compared to healthy donor B cells. In contrast, anti-BCR induced signaling was highly impaired in SLL/CLL and MZL B cells as determined by low p-SFK, p-SYK and p-PLCγ levels. Impaired anti-BCR-induced p-PLCγ was associated with reduced surface expression of IgM and CD79b. Similarly, CD40L-induced p-ERK and p-p38 were also significantly reduced in lymphoma B cells, whereas p-p65 (NF-κB was equal to that of normal B cells. In contrast, IL-2, IL-7 and IL-15 induced p-STAT5 in tumor-infiltrating T cells were not different from normal T cells. Conclusions BCR signaling and CD40L-induced p-p38 was suppressed in malignant B cells from SLL/CLL and MZL patients. Single-cell phospho-specific flow cytometry for detection of basal as well as activation

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

    Directory of Open Access Journals (Sweden)

    Ling Liu

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

  3. Non-CpG Oligonucleotides Exert Adjuvant Effects by Enhancing Cognate B Cell-T Cell Interactions, Leading to B Cell Activation, Differentiation, and Isotype Switching

    Directory of Open Access Journals (Sweden)

    Melinda Herbáth

    2015-01-01

    Full Text Available Natural and synthetic nucleic acids are known to exert immunomodulatory properties. Notably, nucleic acids are known to modulate immune function via several different pathways and various cell types, necessitating a complex interpretation of their effects. In this study we set out to compare the effects of a CpG motif containing oligodeoxynucleotide (ODN with those of a control and an inhibitory non-CpG ODN during cognate B cell-T cell interactions. We employed an antigen presentation system using splenocytes from TCR transgenic DO11.10 mice and the ovalbumin peptide recognized by the TCR as model antigen. We followed early activation events by measuring CD69 expression, late activation by MHC class II expression, cell division and antibody production of switched, and nonswitched isotypes. We found that both of the tested non-CpG ODN exerted significant immunomodulatory effects on early T cell and on late B cell activation events. Importantly, a synergism between non-CpG effects and T cell help acting on B cells was observed, resulting in enhanced IgG production following cognate T cell-B cell interactions. We propose that non-CpG ODN may perform as better adjuvants when a strong antigen-independent immune activation, elicited by CpG ODNs, is undesirable.

  4. B Cells Regulate CD4+ T cell Responses to Papain Following BCR-Independent Papain Uptake

    OpenAIRE

    Dwyer, Daniel F.; Woodruff, Matthew C.; Carroll, Michael C.; Austen, K. Frank; Gurish, Michael F.

    2014-01-01

    Papain, a cysteine protease allergen with inherent adjuvant activity, induces potent IL4 expression by T cells in the popliteal lymph nodes (PLN) of mice following footpad immunization. Here we identify a novel, non-BCR mediated capacity for B cells to rapidly bind and internalize papain. B cells subsequently regulate the adaptive immune response by enhancing Inducible T cell Costimulator (ICOS) expression on CD4+ T cells and amplifying Th2 and T follicular helper induction. Antibody blockade...

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

    OpenAIRE

    Henry, C J; Casas-Selves, M.; Kim, J; Zaberezhnyy, V.; Aghili, L.; Daniel, A.E.; Jimenez, L; Azam, T.; McNamee, E.N.; Clambey, E.T.; Klawitter, J; Serkova, N.J.; Tan, A.C.; Dinarello, C A; DeGregori, J.

    2015-01-01

    The incidence of cancer is higher in the elderly; however, many of the underlying mechanisms for this association remain unexplored. Here, we have shown that B cell progenitors in old mice exhibit marked signaling, gene expression, and metabolic defects. Moreover, B cell progenitors that developed from hematopoietic stem cells (HSCs) transferred from young mice into aged animals exhibited similar fitness defects. We further demonstrated that ectopic expression of the oncogenes BCR-ABL, NRASV1...

  6. 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 of...... 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....

  7. Use of immune-nanoparticles containig chemiotherapeutic agents for the treatment of B-cell malignancies

    OpenAIRE

    Capolla, Sara

    2015-01-01

    B-cell malignancies are a heterogeneous group of clinical conditions including indolent diseases such as Chronic Lymphocytic Leukemia (CLL) and highly aggressive lymphoproliferative disorders such as Burkitt’s lymphoma. B-cell malignancies treatments take advantage of dose-intensive chemotherapeutic regimens and immunotherapy via monoclonal antibodies. Unfortunately, they may lead to insufficient tumor distribution of therapeutic agents and cause several adverse effects. Thus, we propose a...

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

    OpenAIRE

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

    2015-01-01

    A widely accepted model posits that activation of enhancers during differentiation goes through a priming step prior to lineage commitment. To investigate the chronology of enhancer repertoire establishment during hematopoiesis, we monitored epigenome dynamics during three developmental stages representing hematopoietic stem cells, B-cell progenitors and mature B-cells. We find that only a minority of enhancers primed in stem cells or progenitors become active at later stages. Furthermore, mo...

  9. B Cell Infection and Activation by Rabies Virus-Based Vaccines

    OpenAIRE

    Lytle, Andrew G.; Norton, James E.; Dorfmeier, Corin L.; Shen, Shixue; McGettigan, James P.

    2013-01-01

    Replication-deficient rabies viruses (RABV) are promising rabies postexposure vaccines due to their prompt and potent stimulation of protective virus neutralizing antibody titers, which are produced in mice by both T-dependent and T-independent mechanisms. To promote such early and robust B cell stimulation, we hypothesized that live RABV-based vaccines directly infect B cells, thereby activating a large pool of antigen-presenting cells (APCs) capable of providing early priming and costimulat...

  10. Deferoxamine Compensates for Decreases in B Cell Counts and Reduces Mortality in Enterovirus 71-Infected Mice

    OpenAIRE

    Yajun Yang; Jing Ma; Jinghui Xiu; Lin Bai; Feifei Guan; Li Zhang; Jiangning Liu; Lianfeng Zhang

    2014-01-01

    Enterovirus 71 is one of the major causative agents of hand, foot and mouth disease in children under six years of age. No vaccine or antiviral therapy is currently available. In this work, we found that the number of B cells was reduced in enterovirus 71-infected mice. Deferoxamine, a marine microbial natural product, compensated for the decreased levels of B cells caused by enterovirus 71 infection. The neutralizing antibody titer was also improved after deferoxamine treatment. Furthermore...

  11. Polyclonal B-cell stimulation by L3T4+ T cells in experimental leishmaniasis.

    Science.gov (United States)

    Lohoff, M; Matzner, C; Röllinghoff, M

    1988-01-01

    The well-established polyclonal B-cell stimulation in the lymphoid organs in mice infected with Leishmania major is thought to be dependent on T cells. Here we present clear experimental evidence that this is indeed the case by showing that BALB/c-derived, L3T4-positive L. major-specific T cells induce syngeneic B cells to polyclonal proliferation and immunoglobulin production. PMID:3260894

  12. Cyclophosphamide pharmacokinetics and pharmacogenetics in children with B-cell non-Hodgkin's lymphoma

    OpenAIRE

    Veal, Gareth J.; Cole, Michael; Chinnaswamy, Girish; Sludden, Julieann; Jamieson, David; Errington, Julie; Malik, Ghada; Hill, Christopher R.; Chamberlain, Thomas; Boddy, Alan V.

    2016-01-01

    Introduction Variation in cyclophosphamide pharmacokinetics and metabolism has been highlighted as a factor that may impact on clinical outcome in various tumour types. The current study in children with B-cell non-Hodgkin's lymphoma (NHL) was designed to corroborate previous findings in a large prospective study incorporating genotype for common polymorphisms known to influence cyclophosphamide pharmacology. Methods A total of 644 plasma samples collected over a 5 year period, from 49 B-cell...

  13. File list: NoD.Bld.10.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Bld.10.AllAg.Pro-B_cells mm9 No description Blood Pro-B cells SRX1553109,SRX155...3108,SRX1553107,SRX1553110 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Bld.10.AllAg.Pro-B_cells.bed ...

  14. Programming of marginal zone B-cell fate by basic Kruppel-like factor (BKLF/KLF3).

    Science.gov (United States)

    Turchinovich, Gleb; Vu, Thi Thanh; Frommer, Friederike; Kranich, Jan; Schmid, Sonja; Alles, Melanie; Loubert, Jean-Baptiste; Goulet, Jean-Philippe; Zimber-Strobl, Ursula; Schneider, Pascal; Bachl, Jürgen; Pearson, Richard; Crossley, Merlin; Agenès, Fabien; Kirberg, Jörg

    2011-04-01

    Splenic marginal zone (MZ) B cells are a lineage distinct from follicular and peritoneal B1 B cells. They are located next to the marginal sinus where blood is released. Here they pick up antigens and shuttle the load onto follicular dendritic cells inside the follicle. On activation, MZ B cells rapidly differentiate into plasmablasts secreting antibodies, thereby mediating humoral immune responses against blood-borne type 2 T-independent antigens. As Krüppel-like factors are implicated in cell differentiation/function in various tissues, we studied the function of basic Krüppel-like factor (BKLF/KLF3) in B cells. Whereas B-cell development in the bone marrow of KLF3-transgenic mice was unaffected, MZ B-cell numbers in spleen were increased considerably. As revealed in chimeric mice, this occurred cell autonomously, increasing both MZ and peritoneal B1 B-cell subsets. Comparing KLF3-transgenic and nontransgenic follicular B cells by RNA-microarray revealed that KLF3 regulates a subset of genes that was similarly up-regulated/down-regulated on normal MZ B-cell differentiation. Indeed, KLF3 expression overcame the lack of MZ B cells caused by different genetic alterations, such as CD19-deficiency or blockade of B-cell activating factor-receptor signaling, indicating that KLF3 may complement alternative nuclear factor-κB signaling. Thus, KLF3 is a driving force toward MZ B-cell maturation. PMID:21297003

  15. Targeting B cells in immune-mediated inflammatory disease: A comprehensive review of mechanisms of action and identification of biomarkers

    NARCIS (Netherlands)

    T. Dörner; N. Kinnman; P.P. Tak

    2010-01-01

    B cell-depletion therapy, particularly using anti-CD20 treatment, has provided proof of concept that targeting B cells and the humoral response may result in clinical improvements in immune-mediated inflammatory disease. In this review, the mechanisms of action of B cell-targeting drugs are investig

  16. A comparison between protein profiles of B cell subpopulations and mantle cell lymphoma cells

    Directory of Open Access Journals (Sweden)

    Lehtiö Janne

    2009-11-01

    Full Text Available Abstract Background B-cell lymphomas are thought to reflect different stages of B-cell maturation. Based on cytogenetics and molecular markers, mantle cell lymphoma (MCL is presumed to derive predominantly from naïve, pre-germinal centre (pre-GC B lymphocytes. The aim of this study was to develop a method to investigate the similarity between MCL cells and different B-cell compartments on a protein expression level. Methods Subpopulations of B cells representing the germinal centre (GC, the pre-GC mantle zone and the post-GC marginal zone were isolated from tonsils using automated magnetic cell sorting (AutoMACS of cells based on their expression of CD27 and IgD. Protein profiling of the B cell subsets, of cell lines representing different lymphomas and of primary MCL samples was performed using top-down proteomics profiling by surface-enhanced laser detection/ionization time-of-flight mass spectrometry (SELDI-TOF-MS. Results Quantitative MS data of significant protein peaks (p-value Conclusion AutoMACS sorting generates sufficient purity to enable a comparison between protein profiles of B cell subpopulations and malignant B lymphocytes applying SELDI-TOF-MS. Further validation with an increased number of patient samples and identification of differentially expressed proteins would enable a search for possible treatment targets that are expressed during the early development of MCL.

  17. Primary cutaneous diffuse large B-cell lymphoma of the upper limb: A fascinating entity

    Directory of Open Access Journals (Sweden)

    Manoj Madakshira Gopal

    2013-01-01

    Full Text Available Primary cutaneous lymphomas are defined as lymphoid neoplasms that present themselves clinically on the skin and do not have extra-cutaneous disease, when the diagnosis is made or even after 6 months of the diagnosis. Primary cutaneous lymphomas of B-cells are less frequent than lymphomas of T-cells. Primary B-cell lymphomas have a better prognosis than secondary B-cell lymphomas. Primary B-cell cutaneous lymphomas are classified into five types according to the World Health Organization and European Organization for Research and Treatment of Cancer classification. The primary diffuse large B-cell cutaneous lymphoma - leg type corresponds to approximately 5-10% of the B-cell cutaneous lymphomas. It is predominantly seen in elderly people and has a female preponderance. Skin lesions can be single, multiple, and even grouped. A 5-year survival rate ranges from 36 to 100% of the cases. The expression of Bcl-2, presence of multiple lesions, and involvement of both the upper limbs lead to a worse prognosis. Very few cases have been described in the literature.

  18. Clinical and pharmacologic aspects of blinatumomab in the treatment of B-cell acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Portell CA

    2013-04-01

    Full Text Available Craig A Portell, Candice M Wenzell, Anjali S Advani Leukemia Program, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA Abstract: Acute lymphoblastic leukemia (ALL in adults remains a challenging disease to treat, and novel therapies are needed. Precursor-B ALL comprises 80% of cases, and the CD19 antigen is expressed in nearly all precursor-B ALL patients. Bispecific T-cell-engaging antibodies are novel bioengineered proteins. The bispecific T-cell-engaging antibody blinatumomab engages polyclonal T cells to CD19-expressing B cells. By binding to both CD3 and CD19, blinatumomab physically brings these T cells in close proximity to malignant B cells and potentiates T-cell-induced cytotoxic cell kill. Blinatumomab requires continuous intravenous infusion due to its short half-life, the need for continuous exposure for the drug to exert sufficient efficacy, and lessened toxicity. A phase II trial of B-cell ALL patients with persistent or relapsed minimal residual disease demonstrated an 80% rate of complete molecular remission. Cytokine-release syndrome and central nervous system events, such as seizures and encephalopathy, are reversible toxicities. Promising results in B-cell ALL with minimal residual disease have led to further evaluation of this drug in newly diagnosed and relapsed B-cell ALL. Keywords: blinatumomab, B-cell acute lymphoblastic leukemia, CD19, BiTE antibodies

  19. My treatment approach to patients with diffuse large B-cell lymphoma.

    Science.gov (United States)

    Armitage, James O

    2012-02-01

    My favored treatment approach for patients with diffuse large B-cell lymphoma continues to evolve. Diffuse large B-cell lymphoma can now be cured in more than 50% of patients. This is a result of improved definitions of the disease, improved diagnostic capabilities, better staging and restaging techniques, a useful prognostic index to guide therapeutic decisions, and the development of increasingly effective therapies. Positron emission tomographic scans have improved the accuracy of both staging and restaging. Findings on a positron emission tomographic scan at the end of therapy are the best predictors of a good treatment outcome. Numerous subtypes of diffuse large B-cell lymphoma have been identified that require specific treatment approaches. For example, plasmablastic lymphoma typically lacks CD20 and does not benefit from treatment with rituximab. Diffuse large B-cell lymphoma originating in specific extranodal sites such as the central nervous system, testes, and skin presents special problems and requires specific treatment approaches. A subgroup of diffuse large B-cell lymphoma with a very high proliferative rate seems to have a poor outcome when treated with CHOP-R and does better with regimens used for patients with Burkitt lymphoma. New insights into the biology of these disorders are likely to further change treatment approaches. Recognition that diffuse large B-cell lymphoma is not one disease, but a variety of clinicopathologic syndromes provides the opportunity to further improve our ability to benefit patients. PMID:22305028

  20. Neisseria lactamica selectively induces mitogenic proliferation of the naive B cell pool via cell surface Ig.

    Science.gov (United States)

    Vaughan, Andrew T; Brackenbury, Louise S; Massari, Paola; Davenport, Victoria; Gorringe, Andrew; Heyderman, Robert S; Williams, Neil A

    2010-09-15

    Neisseria lactamica is a commensal bacteria that colonizes the human upper respiratory tract mucosa during early childhood. In contrast to the closely related opportunistic pathogen Neisseria meningitidis, there is an absence of adaptive cell-mediated immunity to N. lactamica during the peak age of carriage. Instead, outer membrane vesicles derived from N. lactamica mediate a B cell-dependent proliferative response in mucosal mononuclear cells that is associated with the production of polyclonal IgM. We demonstrate in this study that this is a mitogenic human B cell response that occurs independently of T cell help and any other accessory cell population. The ability to drive B cell proliferation is a highly conserved property and is present in N. lactamica strains derived from diverse clonal complexes. CFSE staining of purified human tonsillar B cells demonstrated that naive IgD(+) and CD27(-) B cells are selectively induced to proliferate by outer membrane vesicles, including the innate CD5(+) subset. Neither purified lipooligosaccharide nor PorB from N. lactamica is likely to be responsible for this activity. Prior treatment of B cells with pronase to remove cell-surface Ig or treatment with BCR-specific Abs abrogated the proliferative response to N. lactamica outer membrane vesicles, suggesting that this mitogenic response is dependent upon the BCR. PMID:20709949

  1. B-cell-specific conditional expression of Myd88p.L252P leads to the development of diffuse large B-cell lymphoma in mice.

    Science.gov (United States)

    Knittel, Gero; Liedgens, Paul; Korovkina, Darya; Seeger, Jens M; Al-Baldawi, Yussor; Al-Maarri, Mona; Fritz, Christian; Vlantis, Katerina; Bezhanova, Svetlana; Scheel, Andreas H; Wolz, Olaf-Oliver; Reimann, Maurice; Möller, Peter; López, Cristina; Schlesner, Matthias; Lohneis, Philipp; Weber, Alexander N R; Trümper, Lorenz; Staudt, Louis M; Ortmann, Monika; Pasparakis, Manolis; Siebert, Reiner; Schmitt, Clemens A; Klatt, Andreas R; Wunderlich, F Thomas; Schäfer, Stephan C; Persigehl, Thorsten; Montesinos-Rongen, Manuel; Odenthal, Margarete; Büttner, Reinhard; Frenzel, Lukas P; Kashkar, Hamid; Reinhardt, H Christian

    2016-06-01

    The adaptor protein MYD88 is critical for relaying activation of Toll-like receptor signaling to NF-κB activation. MYD88 mutations, particularly the p.L265P mutation, have been described in numerous distinct B-cell malignancies, including diffuse large B-cell lymphoma (DLBCL). Twenty-nine percent of activated B-cell-type DLBCL (ABC-DLBCL), which is characterized by constitutive activation of the NF-κB pathway, carry the p.L265P mutation. In addition, ABC-DLBCL frequently displays focal copy number gains affecting BCL2 Here, we generated a novel mouse model in which Cre-mediated recombination, specifically in B cells, leads to the conditional expression of Myd88(p.L252P) (the orthologous position of the human MYD88(p.L265P) mutation) from the endogenous locus. These mice develop a lymphoproliferative disease and occasional transformation into clonal lymphomas. The clonal disease displays the morphologic and immunophenotypical characteristics of ABC-DLBCL. Lymphomagenesis can be accelerated by crossing in a further novel allele, which mediates conditional overexpression of BCL2 Cross-validation experiments in human DLBCL samples revealed that both MYD88 and CD79B mutations are substantially enriched in ABC-DLBCL compared with germinal center B-cell DLBCL. Furthermore, analyses of human DLBCL genome sequencing data confirmed that BCL2 amplifications frequently co-occurred with MYD88 mutations, further validating our approach. Finally, in silico experiments revealed that MYD88-mutant ABC-DLBCL cells in particular display an actionable addiction to BCL2. Altogether, we generated a novel autochthonous mouse model of ABC-DLBCL that could be used as a preclinical platform for the development and validation of novel therapeutic approaches for the treatment of ABC-DLBCL. PMID:27048211

  2. 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

    2016-06-01

    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. PMID:26883634

  3. Regulatory Anatomy

    DEFF Research Database (Denmark)

    Hoeyer, Klaus

    2015-01-01

    This article proposes the term “safety logics” to understand attempts within the European Union (EU) to harmonize member state legislation to ensure a safe and stable supply of human biological material for transplants and transfusions. With safety logics, I refer to assemblages of discourses, le...... arise. In short, I expose the regulatory anatomy of the policy landscape....

  4. Humans with chronic granulomatous disease maintain humoral immunologic memory despite low frequencies of circulating memory B cells

    OpenAIRE

    Moir, Susan; De Ravin, Suk See; Santich, Brian H.; Kim, Jin Young; Posada, Jacqueline G.; Ho, Jason; Buckner, Clarisa M.; Wang, Wei; Kardava, Lela; Garofalo, Mary; Marciano, Beatriz E.; Manischewitz, Jody; King, Lisa R.; Khurana, Surender; Chun, Tae-Wook

    2012-01-01

    CD27+ memory B cells are reduced in the blood of patients with chronic granulomatous disease (CGD) for reasons and consequences that remain unclear. Here we confirm not only decreased CD27+ but also IgG+ B cells in the blood of CGD patients compared with healthy donors (HDs). However, among IgG+ B cells, the ratio of CD27− to CD27+ was significantly higher in CGD patients compared with HDs. Similar to conventional memory B cells, CD27−IgG+ B cells of CGD patients expressed activation markers ...

  5. Enhanced T cell responses to antigenic peptides targeted to B cell surface Ig, Ia, or class I molecules

    OpenAIRE

    1988-01-01

    The helper T cell recognition of soluble globular protein antigens requires that the proteins be processed by an APC, releasing a peptide that is transported to and held on the APC surface where it is recognized by the specific T cell in conjunction with Ia. When cellular processing functions are blocked, APC lose their ability to present native antigens while retaining the capacity to activate T cells when provided with a cognate peptide fragment that contains the T cell antigenic determinan...

  6. High-Dose Y-90-Ibritumomab Tiuxetan Added to Reduced-Intensity Allogeneic Stem Cell Transplant Regimen for Relapsed or Refractory Aggressive B-Cell Lymphoma

    Science.gov (United States)

    2016-07-08

    Post-Transplant Lymphoproliferative Disorder; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma

  7. Distinct TLR-mediated cytokine production and immunoglobulin secretion in human newborn naïve B cells.

    Science.gov (United States)

    Pettengill, Matthew A; van Haren, Simon D; Li, Ning; Dowling, David J; Bergelson, Ilana; Jans, Jop; Ferwerda, Gerben; Levy, Ofer

    2016-08-01

    Neonatal innate immunity is distinct from that of adults, which may contribute to increased susceptibility to infection and limit vaccine responses. B cells play critical roles in protection from infection and detect PAMPs via TLRs, that, when co-activated with CD40, can drive B-cell proliferation and Ab production. We characterized the expression of TLRs in circulating B cells from newborns and adults, and evaluated TLR- and CD40-mediated naïve B-cell class-switch recombination (CSR) and cytokine production. Gene expression levels of most TLRs was similar between newborn and adult B cells, except that newborn naïve B cells expressed more TLR9 than adult naïve B cells. Neonatal naïve B cells demonstrated impaired TLR2- and TLR7- but enhanced TLR9-mediated cytokine production. Significantly fewer newborn naïve B cells underwent CSR to produce IgG, an impairment also noted with IL-21 stimulation. Additionally, co-stimulation via CD40 and TLRs induced greater cytokine production in adult B cells. Thus, while newborn naïve B cells demonstrate adult-level expression of TLRs and CD40, the responses to stimulation of these receptors are distinct. Relatively high expression of TLR9 and impaired CD40-mediated Ig secretion contributes to distinct innate and adaptive immunity of human newborns and may inform novel approaches to early-life immunization. PMID:27252169

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

    Science.gov (United States)

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

    2015-01-13

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

  9. Identification of highly methylated genes across various types of B-cell non-hodgkin lymphoma.

    Directory of Open Access Journals (Sweden)

    Nicole Bethge

    Full Text Available Epigenetic alterations of gene expression are important in the development of cancer. In this study, we identified genes which are epigenetically altered in major lymphoma types. We used DNA microarray technology to assess changes in gene expression after treatment of 11 lymphoma cell lines with epigenetic drugs. We identified 233 genes with upregulated expression in treated cell lines and with downregulated expression in B-cell lymphoma patient samples (n = 480 when compared to normal B cells (n = 5. The top 30 genes were further analyzed by methylation specific PCR (MSP in 18 lymphoma cell lines. Seven of the genes were methylated in more than 70% of the cell lines and were further subjected to quantitative MSP in 37 B-cell lymphoma patient samples (diffuse large B-cell lymphoma (activated B-cell like and germinal center B-cell like subtypes, follicular lymphoma and Burkitt`s lymphoma and normal B lymphocytes from 10 healthy donors. The promoters of DSP, FZD8, KCNH2, and PPP1R14A were methylated in 28%, 67%, 22%, and 78% of the 36 tumor samples, respectively, but not in control samples. Validation using a second series of healthy donor controls (n = 42; normal B cells, peripheral blood mononuclear cells, bone marrow, tonsils and follicular hyperplasia and fresh-frozen lymphoma biopsies (n = 25, confirmed the results. The DNA methylation biomarker panel consisting of DSP, FZD8, KCNH2, and PPP1R14A was positive in 89% (54/61 of all lymphomas. Receiver operating characteristic analysis to determine the discriminative power between lymphoma and healthy control samples showed a c-statistic of 0.96, indicating a possible role for the biomarker panel in monitoring of lymphoma patients.

  10. Effects of B Cell Depletion on Early Mycobacterium tuberculosis Infection in Cynomolgus Macaques.

    Science.gov (United States)

    Phuah, Jiayao; Wong, Eileen A; Gideon, Hannah P; Maiello, Pauline; Coleman, M Teresa; Hendricks, Matthew R; Ruden, Rachel; Cirrincione, Lauren R; Chan, John; Lin, Philana Ling; Flynn, JoAnne L

    2016-05-01

    Although recent studies in mice have shown that components of B cell and humoral immunity can modulate the immune responses against Mycobacterium tuberculosis, the roles of these components in human and nonhuman primate infections are unknown. The cynomolgus macaque (Macaca fascicularis) model of M. tuberculosis infection closely mirrors the infection outcomes and pathology in human tuberculosis (TB). The present study used rituximab, an anti-CD20 antibody, to deplete B cells in M. tuberculosis-infected macaques to examine the contribution of B cells and humoral immunity to the control of TB in nonhuman primates during the acute phase of infection. While there was no difference in the overall pathology, disease profession, and clinical outcome between the rituximab-treated and untreated macaques in acute infection, analyzing individual granulomas revealed that B cell depletion resulted in altered local T cell and cytokine responses, increased bacterial burden, and lower levels of inflammation. There were elevated frequencies of T cells producing interleukin-2 (IL-2), IL-10, and IL-17 and decreased IL-6 and IL-10 levels within granulomas from B cell-depleted animals. The effects of B cell depletion varied among granulomas in an individual animal, as well as among animals, underscoring the previously reported heterogeneity of local immunologic characteristics of tuberculous granulomas in nonhuman primates. Taken together, our data clearly showed that B cells can modulate the local granulomatous response in M. tuberculosis-infected macaques during acute infection. The impact of these alterations on disease progression and outcome in the chronic phase remains to be determined. PMID:26883591

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Microenvironment interactions and B-cell receptor signaling in Chronic Lymphocytic Leukemia: Implications for disease pathogenesis and treatment.

    Science.gov (United States)

    Ten Hacken, Elisa; Burger, Jan A

    2016-03-01

    Chronic Lymphocytic Leukemia (CLL) is a malignancy of mature B lymphocytes which are highly dependent on interactions with the tissue microenvironment for their survival and proliferation. Critical components of the microenvironment are monocyte-derived nurselike cells (NLCs), mesenchymal stromal cells, T cells and NK cells, which communicate with CLL cells through a complex network of adhesion molecules, chemokine receptors, tumor necrosis factor (TNF) family members, and soluble factors. (Auto-) antigens and/or autonomous mechanisms activate the B-cell receptor (BCR) and its downstream signaling cascade in secondary lymphatic tissues, playing a central pathogenetic role in CLL. Novel small molecule inhibitors, including the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib and the phosphoinositide-3-kinase delta (PI3Kδ) inhibitor idelalisib, target BCR signaling and have become the most successful new therapeutics in this disease. We here review the cellular and molecular characteristics of CLL cells, and discuss the cellular components and key pathways involved in the cross-talk with their microenvironment. We also highlight the relevant novel treatment strategies, focusing on immunomodulatory agents and BCR signaling inhibitors and how these treatments disrupt CLL-microenvironment interactions. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance edited by Peter Ruvolo and Gregg L. Semenza. PMID:26193078

  13. Piperlongumine inhibits the proliferation and survival of B-cell acute lymphoblastic leukemia cell lines irrespective of glucocorticoid resistance

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seong-Su, E-mail: seong-su-han@uiowa.edu [Division of Pediatric Hematology-Oncology, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Han, Sangwoo [Health and Human Physiology, University of Iowa Carver College of Medicine, Iowa City, IA (United States); Kamberos, Natalie L. [Division of Pediatric Hematology-Oncology, University of Iowa Carver College of Medicine, Iowa City, IA (United States)

    2014-09-26

    Highlights: • PL inhibits the proliferation of B-ALL cell lines irrespective of GC-resistance. • PL selectively kills B-ALL cells by increasing ROS, but not normal counterpart. • PL does not sensitize majority of B-ALL cells to DEX. • PL represses the network of constitutively activated TFs and modulates their target genes. • PL may serve as a new therapeutic molecule for GC-resistant B-ALL. - Abstract: Piperlongumine (PL), a pepper plant alkaloid from Piper longum, has anti-inflammatory and anti-cancer properties. PL selectively kills both solid and hematologic cancer cells, but not normal counterparts. Here we evaluated the effect of PL on the proliferation and survival of B-cell acute lymphoblastic leukemia (B-ALL), including glucocorticoid (GC)-resistant B-ALL. Regardless of GC-resistance, PL inhibited the proliferation of all B-ALL cell lines, but not normal B cells, in a dose- and time-dependent manner and induced apoptosis via elevation of ROS. Interestingly, PL did not sensitize most of B-ALL cell lines to dexamethasone (DEX). Only UoC-B1 exhibited a weak synergistic effect between PL and DEX. All B-ALL cell lines tested exhibited constitutive activation of multiple transcription factors (TFs), including AP-1, MYC, NF-κB, SP1, STAT1, STAT3, STAT6 and YY1. Treatment of the B-ALL cells with PL significantly downregulated these TFs and modulated their target genes. While activation of AURKB, BIRC5, E2F1, and MYB mRNA levels were significantly downregulated by PL, but SOX4 and XBP levels were increased by PL. Intriguingly, PL also increased the expression of p21 in B-ALL cells through a p53-independent mechanism. Given that these TFs and their target genes play critical roles in a variety of hematological malignancies, our findings provide a strong preclinical rationale for considering PL as a new therapeutic agent for the treatment of B-cell malignancies, including B-ALL and GC-resistant B-ALL.

  14. Identification of Siglec-9 as the receptor for MUC16 on human NK cells, B cells, and monocytes

    Directory of Open Access Journals (Sweden)

    Rancourt Claudine

    2010-05-01

    Full Text Available Abstract Background MUC16 is a cell surface mucin expressed at high levels by epithelial ovarian tumors. Following proteolytic cleavage, cell surface MUC16 (csMUC16 is shed in the extracellular milieu and is detected in the serum of cancer patients as the tumor marker CA125. csMUC16 acts as an adhesion molecule and facilitates peritoneal metastasis of ovarian tumors. Both sMUC16 and csMUC16 also protect cancer cells from cytotoxic responses of natural killer (NK cells. In a previous study we demonstrated that sMUC16 binds to specific subset of NK cells. Here, we identify the csMUC16/sMUC16 binding partner expressed on immune cells. Results Analysis of immune cells from the peripheral blood and peritoneal fluid of ovarian cancer patients indicates that in addition to NK cells, sMUC16 also binds to B cells and monocytes isolated from the peripheral blood and peritoneal fluid. I-type lectin, Siglec-9, is identified as the sMUC16 receptor on these immune cells. Siglec-9 is expressed on approximately 30-40% of CD16pos/CD56dim NK cells, 20-30% of B cells and >95% of monocytes. sMUC16 binds to the majority of the Siglec-9pos NK cells, B cells and monocytes. sMUC16 is released from the immune cells following neuraminidase treatment. Siglec-9 transfected Jurkat cells and monocytes isolated from healthy donors bind to ovarian tumor cells via Siglec-9-csMUC16 interaction. Conclusions Recent studies indicate that csMUC16 can act as an anti-adhesive agent that blocks tumor-immune cell interactions. Our results demonstrate that similar to other mucins, csMUC16 can also facilitate cell adhesion by interacting with a suitable binding partner such as mesothelin or Siglec-9. Siglec-9 is an inhibitory receptor that attenuates T cell and NK cell function. sMUC16/csMUC16-Siglec-9 binding likely mediates inhibition of anti-tumor immune responses.

  15. Piperlongumine inhibits the proliferation and survival of B-cell acute lymphoblastic leukemia cell lines irrespective of glucocorticoid resistance

    International Nuclear Information System (INIS)

    Highlights: • PL inhibits the proliferation of B-ALL cell lines irrespective of GC-resistance. • PL selectively kills B-ALL cells by increasing ROS, but not normal counterpart. • PL does not sensitize majority of B-ALL cells to DEX. • PL represses the network of constitutively activated TFs and modulates their target genes. • PL may serve as a new therapeutic molecule for GC-resistant B-ALL. - Abstract: Piperlongumine (PL), a pepper plant alkaloid from Piper longum, has anti-inflammatory and anti-cancer properties. PL selectively kills both solid and hematologic cancer cells, but not normal counterparts. Here we evaluated the effect of PL on the proliferation and survival of B-cell acute lymphoblastic leukemia (B-ALL), including glucocorticoid (GC)-resistant B-ALL. Regardless of GC-resistance, PL inhibited the proliferation of all B-ALL cell lines, but not normal B cells, in a dose- and time-dependent manner and induced apoptosis via elevation of ROS. Interestingly, PL did not sensitize most of B-ALL cell lines to dexamethasone (DEX). Only UoC-B1 exhibited a weak synergistic effect between PL and DEX. All B-ALL cell lines tested exhibited constitutive activation of multiple transcription factors (TFs), including AP-1, MYC, NF-κB, SP1, STAT1, STAT3, STAT6 and YY1. Treatment of the B-ALL cells with PL significantly downregulated these TFs and modulated their target genes. While activation of AURKB, BIRC5, E2F1, and MYB mRNA levels were significantly downregulated by PL, but SOX4 and XBP levels were increased by PL. Intriguingly, PL also increased the expression of p21 in B-ALL cells through a p53-independent mechanism. Given that these TFs and their target genes play critical roles in a variety of hematological malignancies, our findings provide a strong preclinical rationale for considering PL as a new therapeutic agent for the treatment of B-cell malignancies, including B-ALL and GC-resistant B-ALL

  16. Double-Positive CD21+CD27+ B Cells Are Highly Proliferating Memory Cells and Their Distribution Differs in Mucosal and Peripheral Tissues

    OpenAIRE

    Das, Arpita; Xu, Huanbin; Wang, Xiaolei; Yau, Canddy L.; Veazey, Ronald S.; Pahar, Bapi

    2011-01-01

    Background Several B-cell defects arise in HIV infected patients, particularly in patients with chronic infection and high viral load. Loss of memory B cells (CD27+ B cells) in peripheral blood and lymphoid tissues is one of the major B cell dysfunctions in HIV and simian immunodeficiency virus (SIV) infection. Despite several studies, definitive identification of memory B cells based on CD27 surface expression has not been described. Similarly, the rates of cell turnover in different B cell ...

  17. Machine Learning-based Classification of Diffuse Large B-cell Lymphoma Patients by Their Protein Expression Profiles.

    Science.gov (United States)

    Deeb, Sally J; Tyanova, Stefka; Hummel, Michael; Schmidt-Supprian, Marc; Cox, Juergen; Mann, Matthias

    2015-11-01

    Characterization of tumors at the molecular level has improved our knowledge of cancer causation and progression. Proteomic analysis of their signaling pathways promises to enhance our understanding of cancer aberrations at the functional level, but this requires accurate and robust tools. Here, we develop a state of the art quantitative mass spectrometric pipeline to characterize formalin-fixed paraffin-embedded tissues of patients with closely related subtypes of diffuse large B-cell lymphoma. We combined a super-SILAC approach with label-free quantification (hybrid LFQ) to address situations where the protein is absent in the super-SILAC standard but present in the patient samples. Shotgun proteomic analysis on a quadrupole Orbitrap quantified almost 9,000 tumor proteins in 20 patients. The quantitative accuracy of our approach allowed the segregation of diffuse large B-cell lymphoma patients according to their cell of origin using both their global protein expression patterns and the 55-protein signature obtained previously from patient-derived cell lines (Deeb, S. J., D'Souza, R. C., Cox, J., Schmidt-Supprian, M., and Mann, M. (2012) Mol. Cell. Proteomics 11, 77-89). Expression levels of individual segregation-driving proteins as well as categories such as extracellular matrix proteins behaved consistently with known trends between the subtypes. We used machine learning (support vector machines) to extract candidate proteins with the highest segregating power. A panel of four proteins (PALD1, MME, TNFAIP8, and TBC1D4) is predicted to classify patients with low error rates. Highly ranked proteins from the support vector analysis revealed differential expression of core signaling molecules between the subtypes, elucidating aspects of their pathobiology. PMID:26311899

  18. Differential requirements of MyD88 and TRIF pathways in TLR4-mediated immune responses in murine B cells.

    Science.gov (United States)

    Yanagibashi, Tsutomu; Nagai, Yoshinori; Watanabe, Yasuharu; Ikutani, Masashi; Hirai, Yoshikatsu; Takatsu, Kiyoshi

    2015-01-01

    LPS stimulates the TLR4/Myeloid differentiation protein-2 (MD-2) complex and promotes a variety of immune responses in B cells. TLR4 has two main signaling pathways, MyD88 and Toll/IL-1R (TIR)-domain-containing adaptor-inducing interferon-β (TRIF) pathways, but relatively few studies have examined these pathways in B cells. In this study, we investigated MyD88- or TRIF-dependent LPS responses in B cells by utilizing their knockout mice. Compared with wild-type (WT) B cells, MyD88(-/-) B cells were markedly impaired in up-regulation of CD86 and proliferation induced by lipid A moiety of LPS. TRIF(-/-) B cells were also impaired in these responses compared with WT B cells, but showed better responses than MyD88(-/-) B cells. Regarding class switch recombination (CSR) elicited by lipid A plus IL-4, MyD88(-/-) B cells showed similar patterns of CSR to WT B cells. However, TRIF(-/-) B cells showed the impaired in the CSR. Compared with WT and MyD88(-/-) B cells, TRIF(-/-) B cells exhibited reduced cell division, fewer IgG1(+) cells per division, and decreased activation-induced cytidine deaminase (Aicda) mRNA expression in response to lipid A plus IL-4. Finally, IgG1 production to trinitrophenyl (TNP)-LPS immunization was impaired in TRIF(-/-) mice, while MyD88(-/-) mice exhibited increased IgG1 production. Thus, MyD88 and TRIF pathways differently regulate TLR4-induced immune responses in B cells. PMID:25448706

  19. Proliferation of resting B cells is modulated by CR2 and CR1.

    Science.gov (United States)

    Fingeroth, J D; Heath, M E; Ambrosino, D M

    1989-06-15

    Absence of the third component of complement, C3, is associated with impaired ability to synthesize antibody, particularly in the presence of limiting antigen [1-9]. The mature B lymphocyte bearing the surface immunoglobulin receptor transduces signals for proliferation and differentiation upon binding of specific antigen. This mature B cell also bears two related membrane proteins, CR2 (the C3d/Epstein-Barr virus receptor) (CD35) [15], which can mediate the binding of ligands to which appropriate cleavage fragments of C3 have become attached [16]. It has been suggested that these receptors play a direct role(s) in B cell activation [17-25]. In light of previous in vivo observations we decided to assess the function of CR2 and CR1 in relation to B cell activation through the membrane IgM receptor. Highly purified splenic B cells were prepared. No contaminating T cells or macrophages were detected by flow cytometric analysis and no proliferative activity was present upon PHA or ConA stimulation of the purified cells. The B cells were separated into low (activated), medium (preactivated) and high density (resting) fractions by Percoll gradient density centrifugation [26]. The responses of the B cell subpopulations to various concentrations of anti mu (DA4.4 monoclonal antibody) [27] were examined for proliferation at 72 h and for IgM/IgG production at 7 days. Low density B cells were maximally stimulated and no concentration of anti-mu was effective in enhancing their responses. High density B cells proliferated to anti-mu in a concentration dependent manner. When substimulatory concentrations of anti-mu were employed, concomitant crosslinking of CR2 (with either of 2 distinct monoclonal antibodies HB-5 [28] or OKB7 [17]) resulted in a 45% enhancement of B cell proliferation above that observed by crosslinking of SIgM alone. In these studies, total IgM and IgG did not increase in the absence of T cells or T cell factors, indicating that terminal differentiation did

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

    Directory of Open Access Journals (Sweden)

    Georg Lenz

    2015-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lenz, Georg [Translational Oncology, Department of Medicine A, Albert-Schweitzer Campus 1, University Hospital Münster, 48149 Münster (Germany); Cluster of Excellence EXC 1003, Cells in Motion, 48149 Münster (Germany)

    2015-05-22

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

  2. B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Burkitt's lymphoma: A case report and review

    Directory of Open Access Journals (Sweden)

    Tabita Joy Chettiankandy

    2016-01-01

    Full Text Available B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL and classical Burkitt's lymphoma (BL, is a diagnostic provisional category in the World Health Organization 2008 classification of lymphomas. This category was designed as a measure to accommodate borderline cases that cannot be reliably classified into a single distinct disease entity after all available morphological, immunophenotypical and molecular studies have been performed. Typically, these cases share features intermediate between DLBCL and classical BL or include characteristics of both lymphomas. The rarity of such cases poses a tremendous challenge to both pathologists and oncologists because its differential diagnosis has direct implications for management strategies. In this article, we present a “classical unclassifiable lymphoma with features intermediate between DLBCL and BL” in a young male patient and review of literature.

  3. NFATc1 supports imiquimod-induced skin inflammation by suppressing IL-10 synthesis in B cells.

    Science.gov (United States)

    Alrefai, Hani; Muhammad, Khalid; Rudolf, Ronald; Pham, Duong Anh Thuy; Klein-Hessling, Stefan; Patra, Amiya K; Avots, Andris; Bukur, Valesca; Sahin, Ugur; Tenzer, Stefan; Goebeler, Matthias; Kerstan, Andreas; Serfling, Edgar

    2016-01-01

    Epicutaneous application of Aldara cream containing the TLR7 agonist imiquimod (IMQ) to mice induces skin inflammation that exhibits many aspects of psoriasis, an inflammatory human skin disease. Here we show that mice depleted of B cells or bearing interleukin (IL)-10-deficient B cells show a fulminant inflammation upon IMQ exposure, whereas ablation of NFATc1 in B cells results in a suppression of Aldara-induced inflammation. In vitro, IMQ induces the proliferation and IL-10 expression by B cells that is blocked by BCR signals inducing NFATc1. By binding to HDAC1, a transcriptional repressor, and to an intronic site of the Il10 gene, NFATc1 suppresses IL-10 expression that dampens the production of tumour necrosis factor-α and IL-17 by T cells. These data indicate a close link between NFATc1 and IL-10 expression in B cells and suggest NFATc1 and, in particular, its inducible short isoform, NFATc1/αA, as a potential target to treat human psoriasis. PMID:27222343

  4. B cell-specific S1PR1 deficiency blocks prion dissemination between secondary lymphoid organs.

    Science.gov (United States)

    Mok, Simon W F; Proia, Richard L; Brinkmann, Volker; Mabbott, Neil A

    2012-05-15

    Many prion diseases are peripherally acquired (e.g., orally or via lesions to skin or mucous membranes). After peripheral exposure, prions replicate first upon follicular dendritic cells (FDC) in the draining lymphoid tissue before infecting the brain. However, after replication upon FDC within the draining lymphoid tissue, prions are subsequently propagated to most nondraining secondary lymphoid organs (SLO), including the spleen, by a previously underdetermined mechanism. The germinal centers in which FDC are situated produce a population of B cells that can recirculate between SLO. Therefore, we reasoned that B cells were ideal candidates by which prion dissemination between SLO may occur. Sphingosine 1-phosphate receptor (S1PR)1 stimulation controls the egress of T and B cells from SLO. S1PR1 signaling blockade sequesters lymphocytes within SLO, resulting in lymphopenia in the blood and lymph. We show that, in mice treated with the S1PR modulator FTY720 or with S1PR1 deficiency restricted to B cells, the dissemination of prions from the draining lymph node to nondraining SLO is blocked. These data suggest that B cells interacting with and acquiring surface proteins from FDC and recirculating between SLO via the blood and lymph mediate the initial propagation of prions from the draining lymphoid tissue to peripheral tissues. PMID:22504650

  5. Secondary pancreatic involvement by a diffuse large B-cell lymphoma presenting as acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    M Wasif Saif; Sapna Khubchandani; Marek Walczak

    2007-01-01

    Diffuse large B-cell lymphoma is the most common type of non-Hodgkin's lymphoma. More than 50% of patients have some site of extra-nodal involvement at diagnosis,including the gastrointestinal tract and bone marrow.However, a diffuse large B-cell lymphoma presenting as acute pancreatitis is rare. A 57-year-old female presented with abdominal pain and matted lymph nodes in her axilla. She was admitted with a diagnosis of acute pancreatitis. Abdominal computed tomography (CT) scan showed diffusely enlarged pancreas due to infiltrative neoplasm and peripancreatic lymphadenopathy. Biopsy of the axillary mass revealed a large B-cell lymphoma.The patient was classified as stage Ⅳ, based on the Ann Arbor Classification, and as having a high-risk lymphoma,based on the International Prognostic Index. She was started on chemotherapy with CHOP (cyclophosphamide,doxorubicin, vincristine and prednisone). Within a week after chemotherapy, the patient's abdominal pain resolved. Follow-up CT scan of the abdomen revealed a marked decrease in the size of the pancreas and peripancreatic lymphadenopathy. A literature search revealed only seven cases of primary involvement of the pancreas in B-cell lymphoma presenting as acute pancreatitis. However, only one case of secondary pancreatic involvement by B-cell lymphoma presenting as acute pancreatitis has been published. Our case appears to be the second report of such a manifestation.Both cases responded well to chemotherapy.

  6. Congenital B cell lymphocytosis explained by novel germline CARD11 mutations.

    Science.gov (United States)

    Snow, Andrew L; Xiao, Wenming; Stinson, Jeffrey R; Lu, Wei; Chaigne-Delalande, Benjamin; Zheng, Lixin; Pittaluga, Stefania; Matthews, Helen F; Schmitz, Roland; Jhavar, Sameer; Kuchen, Stefan; Kardava, Lela; Wang, Wei; Lamborn, Ian T; Jing, Huie; Raffeld, Mark; Moir, Susan; Fleisher, Thomas A; Staudt, Louis M; Su, Helen C; Lenardo, Michael J

    2012-11-19

    Nuclear factor-κB (NF-κB) controls genes involved in normal lymphocyte functions, but constitutive NF-κB activation is often associated with B cell malignancy. Using high-throughput whole transcriptome sequencing, we investigated a unique family with hereditary polyclonal B cell lymphocytosis. We found a novel germline heterozygous missense mutation (E127G) in affected patients in the gene encoding CARD11, a scaffolding protein required for antigen receptor (AgR)-induced NF-κB activation in both B and T lymphocytes. We subsequently identified a second germline mutation (G116S) in an unrelated, phenotypically similar patient, confirming mutations in CARD11 drive disease. Like somatic, gain-of-function CARD11 mutations described in B cell lymphoma, these germline CARD11 mutants spontaneously aggregate and drive constitutive NF-κB activation. However, these CARD11 mutants rendered patient T cells less responsive to AgR-induced activation. By reexamining this rare genetic disorder first reported four decades ago, our findings provide new insight into why activating CARD11 mutations may induce B cell expansion and preferentially predispose to B cell malignancy without dramatically perturbing T cell homeostasis. PMID:23129749

  7. Persistence of Marek's disease virus in a subpopulation of B cells that is transformed by avian leukosis virus, but not in normal bursal B cells.

    OpenAIRE

    Fynan, E; Block, T M; DuHadaway, J; Olson, W; Ewert, D L

    1992-01-01

    Previous studies have described an augmentation of avian leukosis virus (ALV)-induced lymphoid leukosis in chickens that were coinfected with a serotype 2 Marek's disease virus (MDV) strain, SB-1. As a first step toward understanding the mechanism of this augmentation, we have analyzed the tropism of the MDV for the ALV-transformed B cell. After hatching, chickens were coinfected with ALV and a nonpathogenic strain of MDV, SB-1. Seventy primary and metastatic ALV-induced lymphomas that develo...

  8. Membrane fluidity increases during apoptosis of sheep ileal Peyer's patch B cells

    International Nuclear Information System (INIS)

    To investigate specific plasma membrane structural changes associated with apoptosis, whole cells and purified plasma membranes of apoptotic B cells from the ileal Peyer's patch of sheep were analyzed for their 'membrane fluidity'. The ileal Peyer's patch of sheep provided a large number of B cells required for plasma membrane isolation (>5 x 109). As the incidence of apoptosis increased with time of culture, the fluidity of purified plasma membranes, as measured with the fluorophore DPH (diphenylhexatriene), increased. To evaluate this phenomenon with intact cells, B cells at different apoptotic stages were fractionated on discontinuous Percoll gradients. Similar results were obtained using the fluorophore TMA-DPH (trimethylammoniumdiphenylhexatriene), which has been shown to localize specifically to the plasma membrane. Functionally, the increase in plasma membrane fluidity associated with apoptosis may represent either a mechanism to cycle phosphatidylserine to the outer leaflet, mediating phagocytic recognition of apoptotic cells, or a consequence of this event. (author). 20 refs., 1 tab., 4 figs

  9. Breast schwannoma in a patient with diffuse large B-cell lymphoma: a case report

    Directory of Open Access Journals (Sweden)

    Salihoglu Ayse

    2012-12-01

    Full Text Available Abstract Introduction Schwannomas are mostly benign tumors arising from Schwann cells of the nerve sheaths. Breast schwannomas are very rare and account for only 2.6% of cases. As far as we know this is the first reported case of breast schwannoma discovered in a patient with diffuse large B-cell lymphoma. The breast schwannoma was evaluated with positron emission tomography and it exhibited moderate 18F-fluorodeoxyglucose uptake. Case presentation We present the case of a breast schwannoma in a 63-year-old Caucasian woman who was diagnosed with diffuse large B-cell lymphoma. Conclusion Imaging modalities including positron emission tomography-computed tomography failed to distinguish breast schwannoma from diffuse large B-cell lymphoma involvement of the breast.

  10. Hemophagocytic lymphohistiocytosis secondary to T-cell/histiocyte-rich large B-cell lymphoma

    Directory of Open Access Journals (Sweden)

    Katherine Devitt

    2014-01-01

    Full Text Available Hemophagocytic lymphohistiocytosis (HLH is a life-threatening clinical syndrome characterized by dysregulation of the immune system. Impaired function of cytotoxic T cells and natural killer cells is often seen, and T-cell malignancies represent most cases of lymphoma-associated HLH. HLH associated with B-cell lymphoma is rare. We describe a case of a 30-year-old man who presented with fever, splenomegaly, and hyperferritinemia. Bone marrow biopsy revealed T-cell/histiocyte-rich large B-cell lymphoma, a rare, aggressive B-cell malignancy. This case highlights the interplay between a pro-inflammatory cytokine microenvironment and tumor-mediated immune suppression, and addresses the importance of accurately diagnosing these entities for appropriate clinical management.

  11. Deferoxamine Compensates for Decreases in B Cell Counts and Reduces Mortality in Enterovirus 71-Infected Mice

    Directory of Open Access Journals (Sweden)

    Yajun Yang

    2014-07-01

    Full Text Available Enterovirus 71 is one of the major causative agents of hand, foot and mouth disease in children under six years of age. No vaccine or antiviral therapy is currently available. In this work, we found that the number of B cells was reduced in enterovirus 71-infected mice. Deferoxamine, a marine microbial natural product, compensated for the decreased levels of B cells caused by enterovirus 71 infection. The neutralizing antibody titer was also improved after deferoxamine treatment. Furthermore, deferoxamine relieved symptoms and reduced mortality and muscle damage caused by enterovirus 71 infection. This work suggested that deferoxamine has the potential for further development as a B cell-immunomodulator against enterovirus 71.

  12. Cancer Stem Cells of Differentiated B-Cell Malignancies: Models and Consequences

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Emilie; Quillet-Mary, Anne [INSERM, UMR1037-Cancer Research Center of Toulouse, 31300 Toulouse (France); ERL 5294 CNRS, BP3028 CHU Purpan, 31300 Toulouse (France); Université Toulouse III Paul-Sabatier, 31300 Toulouse (France); Ysebaert, Loic; Laurent, Guy [INSERM, UMR1037-Cancer Research Center of Toulouse, 31300 Toulouse (France); ERL 5294 CNRS, BP3028 CHU Purpan, 31300 Toulouse (France); Université Toulouse III Paul-Sabatier, 31300 Toulouse (France); Service d' Hématologie, CHU Purpan, 31300 Toulouse (France); Fournie, Jean-Jacques, E-mail: jean-jacques.fournie@inserm.fr [INSERM, UMR1037-Cancer Research Center of Toulouse, 31300 Toulouse (France); ERL 5294 CNRS, BP3028 CHU Purpan, 31300 Toulouse (France); Université Toulouse III Paul-Sabatier, 31300 Toulouse (France)

    2011-03-25

    The concept of cancer stem cells has revolutionized our current vision of cancer development and was validated in solid tumors and cancers of the primitive hematopoietic compartment. Proof of the principle is still lacking, however, in malignancies of differentiated B-cells. We review here the current literature, which nevertheless suggests hierarchical organizations of the tumor clone for mostly incurable B-cell cancers such as multiple myeloma, lymphomas and B-chronic lymphocytic leukemia. We propose two models accounting for cancer stem cells in these contexts: a “top-to-bottom” clonal hierarchy from memory B-cells and a “bottom-to-top” model of clonal reprogramming. Selection pressure on the growing tumor can drive such reprogramming and increase its genetic diversity.

  13. Towards a consensus on datasets and evaluation metrics for developing B-cell epitope prediction tools

    DEFF Research Database (Denmark)

    Greenbaum, Jason A.; Andersen, Pernille; Blythe, Martin;

    2007-01-01

    and immunology communities. Improving the accuracy of B-cell epitope prediction methods depends on a community consensus on the data and metrics utilized to develop and evaluate such tools. A workshop, sponsored by the National Institute of Allergy and Infectious Disease (NIAID), was recently held in Washington......, DC to discuss the current state of the B-cell epitope prediction field. Many of the currently available tools were surveyed and a set of recommendations was devised to facilitate improvements in the currently existing tools and to expedite future tool development. An underlying theme...... of the recommendations put forth by the panel is increased collaboration among research groups. By developing common datasets, standardized data formats, and the means with which to consolidate information, we hope to greatly enhance the development of B-cell epitope prediction tools. (c) 2007 John Wiley & Sons, Ltd....

  14. Retrospective Analysis of T and B Cells Flow-Cross Matches in Renal Transplant Recipients

    Directory of Open Access Journals (Sweden)

    Lakshmi Kiran C

    2008-01-01

    Full Text Available Complement-mediated cytotoxic antibodies in conventional cross match, often result in misappropriation of true positives and borderline positives which are detrimental to allograft survival. Flow cross matches (FCXM are sensitive to capture even non comple-ment fixing cytotoxic antibodies. This retrospective study evaluates the utility of FCXM in effectively predicting acute allograft rejection. A total of 17 cases were processed for FCXM (T and B cell of whom seven had no rejection episodes, while the remaining 11 had acute rejection despite negative cross match and panel reacting antibodies being ne-gative (less than 20%. The sensitivity and specificity of the FCXM outcome demons-trated that positive B-cell FCXM has potential to be a good tool in pre-transplant scree-ning. The current analysis proposes the possible utility of B-cell positive FCXM as a more sensitive parameter in predicting acute allograft rejection prior to transplantation.

  15. Cancer Stem Cells of Differentiated B-Cell Malignancies: Models and Consequences

    International Nuclear Information System (INIS)

    The concept of cancer stem cells has revolutionized our current vision of cancer development and was validated in solid tumors and cancers of the primitive hematopoietic compartment. Proof of the principle is still lacking, however, in malignancies of differentiated B-cells. We review here the current literature, which nevertheless suggests hierarchical organizations of the tumor clone for mostly incurable B-cell cancers such as multiple myeloma, lymphomas and B-chronic lymphocytic leukemia. We propose two models accounting for cancer stem cells in these contexts: a “top-to-bottom” clonal hierarchy from memory B-cells and a “bottom-to-top” model of clonal reprogramming. Selection pressure on the growing tumor can drive such reprogramming and increase its genetic diversity

  16. Antibody-independent control of gamma-herpesvirus latency via B cell induction of anti-viral T cell responses.

    Directory of Open Access Journals (Sweden)

    Kelly B McClellan

    2006-06-01

    Full Text Available B cells can use antibody-dependent mechanisms to control latent viral infections. It is unknown whether this represents the sole function of B cells during chronic viral infection. We report here that hen egg lysozyme (HEL-specific B cells can contribute to the control of murine gamma-herpesvirus 68 (gammaHV68 latency without producing anti-viral antibody. HEL-specific B cells normalized defects in T cell numbers and proliferation observed in B cell-/- mice during the early phase of gammaHV68 latency. HEL-specific B cells also reversed defects in CD8 and CD4 T cell cytokine production observed in B cell-/- mice, generating CD8 and CD4 T cells necessary for control of latency. Furthermore, HEL-specific B cells were able to present virally encoded antigen to CD8 T cells. Therefore, B cells have antibody independent functions, including antigen presentation, that are important for control of gamma-herpesvirus latency. Exploitation of this property of B cells may allow enhanced vaccine responses to chronic virus infection.

  17. Plasmacytoid dendritic cells regulate autoreactive B cell activation via soluble factors and in a cell-to-cell contact manner.

    Science.gov (United States)

    Ding, Chuanlin; Cai, Yihua; Marroquin, Jose; Ildstad, Suzanne T; Yan, Jun

    2009-12-01

    Plasmacytoid dendritic cells (pDCs) are specialized type I IFN producers, which play an important role in pathogenesis of autoimmune disorders. Dysregulated autoreactive B cell activation is a hallmark in most autoimmune diseases. This study was undertaken to investigate interactions between pDCs and autoreactive B cells. After coculture of autoreactive B cells that recognize self-Ag small nuclear ribonucleoprotein particles with activated pDCs, we found that pDCs significantly enhance autoreactive B cell proliferation, autoantibody production, and survival in response to TLR and BCR stimulation. Neutralization of IFN-alpha/beta and IL-6 abrogated partially pDC-mediated enhancement of autoreactive B cell activation. Transwell studies demonstrated that pDCs could provide activation signals to autoreactive B cells via a cell-to-cell contact manner. The involvement of the ICAM-1-LFA-1 pathway was revealed as contributing to this effect. This in vitro enhancement effect was further demonstrated by an in vivo B cell adoptive transfer experiment, which showed that autoreactive B cell proliferation and activation were significantly decreased in MyD88-deficient mice compared with wild-type mice. These data suggest the dynamic interplay between pDCs and B cells is required for full activation of autoreactive B cells upon TLR or BCR stimulation. PMID:19890051

  18. Mitogen-stimulated phospholipid synthesis in normal and immune-deficient human B cells

    International Nuclear Information System (INIS)

    Eight patients with common variable panhypogammaglobulinemia were shown in the in vitro Ig biosynthesis assay to have defective B cell responses to pokeweed mitogen (PWM). Phospholipid synthesis was assessed in the B cell plus monocyte fraction (MB) and irradiated T cells (T*) of patients and paired normal controls. Cell populations were studied separately and in the four possible combinations (1:1), with and without PWM, to reveal the effect of cell interactions. At 16 to 20 hr the mean stimulation index (SI) +/- standard error for MB cells alone was 1.01 +/- 0.02 for eight patients and 0.99 +/- 0.02 for the paired normals; the T* cell SI was 1.25 +/- 0.04 for patients and 1.28 +/- 0.05 for normals. Combinations of normal MB cells with normal T* cells showed significantly higher SI when compared with the combinations of normal MB cells with patient T* cells (p less than 0.005). However, the combination of patient MB cells with patient T* cells and the combination of patient MB cells with normal T* cells were not significantly different in SI (0.05 less than p less than 0.1). Isolation of patient and normal B cells, T* cells, and monocytes after the choline pulse showed that patient B cells gave a higher SI with normal T* help than with patient T* help. Of greatest interest is the finding that patient B cells that were defective in PWM-stimulated Ig production nevertheless showed a phospholipid synthesis response to PWM in the normal range, suggesting that the maturation defect in these B cells occurs later than the phospholipid synthesis acceleration step, or on a different pathway

  19. Diffuse large B-cell lymphoma in patient after treatment of angioimmunoblastic T-cell lymphoma.

    Science.gov (United States)

    Skugor, Nives Dzeko; Perić, Zinaida; Vrhovac, Radovan; Radić-Kristo, Delfa; Kardum-Skelin, Ika; Jaksić, Branimir

    2010-03-01

    Relatively few cases of Epstein-Barr (EBV)-positive B-cell lymphomas arising in patients with angioimmunoblastic T-cell lymphoma (AITL) have been reported. We report a case of AITL in which diffuse large B-cell lymphoma arose 13 months after the initial diagnosis of AITL. In a 36-year-old female patient, evaluated for moderate leukocytosis, peripheral and abdominal lymphadenopathy AITL was diagnosed in March 2008, based on results of fine-needle aspiration cytology (FNAC) of the enlarged cervical and supraclavicular lymph nodes. The diagnosis was also confirmed by immunophenotyping and histopathology of the cervical lymph nodes. The patient initially recieved FED chemotherapy (fludarabine, cyclophosphamide, dexamethasone) followed by elective autologous hematopoietic stem cell transplantation. In April 2009 the patient was hospitalized because of fever, pancytopenia, hyperbilirubinemia and peripheral lymphadenopathy. The FNAC of the enlarged cervical lymph nodes was performed again, but this time the smears were composed of polymorphous population of lymphocytes with the predomination of large cells, CD20+ on immunocytochemical stains. The immunophenotyping confirmed a predomination of monoclonal mature B-cells. Patient had high number of EBV DNA copies in plasma and serologic testing revealed increased titers of EBV VCA IgG and EBV EBNA IgG. CHOP-R chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab) was then administered, resulting in good partial response of the disease. Reduced intensity allogeneic stem cell transplantation performed thereafter, resulted in complete remission of the disease. AITL is a rare lymphoproliferative disorder in which the neoplastic T-cells represent the minority of the lymph node cell population and almost all cases harbor EBV-infected B-cells. Various authors postulated that immunodeficiency in AITL patients together with immunosuppressive effects of cytotoxic drugs, may be responsible for EBV

  20. B-cell Lymphoma in retrieved femoral heads: a long term follow up

    Directory of Open Access Journals (Sweden)

    van Kemenade Folkert J

    2009-05-01

    Full Text Available Abstract Background A relatively high incidence of pathological conditions in retrieved femoral heads, including a group of patients having low grade B-cell lymphoma, has been described before. At short term follow up none of these patients with low-grade B-cell lymphoma showed evidence of systemic disease. However, the long term follow up of these patients is not known. Methods From November 1994 up to and including December 2005 we screened all femoral heads removed at the time of primary total hip replacement histopathologically and included them in the bone banking protocol according to the guidelines of the American Associations of Tissue Banks (AATB and the European Association of Musculo-Skeletal Transplantation (EAMST. We determined the percentage of B-cell lymphoma in all femoral heads and in the group that fulfilled all criteria of the bone banking protocol and report on the long-term follow-up. Results Of 852 femoral heads fourteen (1.6% were highly suspicious for low-grade B-cell lymphoma. Of these 852 femoral heads, 504 were eligible for bone transplantation according to the guidelines of the AATB and the EAMST. Six femoral heads of this group of 504 were highly suspicious for low-grade B-cell lymphoma (1.2%. At long term follow up two (0.2% of all patients developed systemic malignant disease and one of them needed medical treatment for her condition. Conclusion In routine histopathological screening we found variable numbers of low-grade B-cell lymphoma throughout the years, even in a group of femoral heads that were eligible for bone transplantation. Allogenic transmission of malignancy has not yet been reported on, but surviving viruses are proven to be transmissible. Therefore, we recommend the routine histopathological evaluation of all femoral heads removed at primary total hip arthroplasty as a tool for quality control, whether the femoral head is used for bone banking or not.

  1. A comparative review of aging and B cell function in mice and humans

    OpenAIRE

    Scholz, Jean L.; Diaz, Alain; Riley, Richard L.; Cancro, Michael P.; Frasca, Daniela

    2013-01-01

    Immune system function declines with age. Here we review and compare age-associated changes in murine and human B cell pools and humoral immune responses. We summarize changes in B cell generation and homeostasis, as well as notable changes at the sub-cellular level; then discuss how these changes help to explain alterations in immune responses across the adult lifespan of the animal. In each section we compare and contrast findings in the mouse, arguably the best animal model of the aging im...

  2. Primary lymphoblastic B-cell lymphoma of the stomach: A case report

    Institute of Scientific and Technical Information of China (English)

    Miao-Xia He; Ming-Hua Zhu; Wei-Qiang Liu; Li-Li Wu; Xiong-Zeng Zhu

    2008-01-01

    Primary stomach lymphoblastic B-cell lymphoma (B-LBL) is a rare tumor. We describe a primary stomach B-LBL in a 38 years old female who presented with nonspecific complaints of fatigue and vomiting for 2 mo.Gastrofiberscopy revealed a large gastric ulcer, which was successfully resected. Pathology showed a lymphoblastic cell lymphoma arising from the stomach, and there was no evidence of disease at any extrastomach site.Immunohistochemical staining and gene rearrangement studies supported that the stomach tumor was a clonal B-cell lymphoma. Therefore, the diagnosis of B-LBL was made based on the stomach specimen.

  3. Blockade of B-cell-activating factor suppresses lupus-like syndrome in autoimmune BXSB mice

    OpenAIRE

    Ding, Hanlu; Wang, Li; Wu, Xiongfei; Yan, Jun; He, Yani; Ni, Bing; Gao, Wenda; Zhong, Xuemei

    2009-01-01

    Abstract B-cell-activating factor (BAFF), a member of the tumour necrosis factor superfamily, plays a critical role in the maturation, homeostasis and function of B cells. In this study, we demonstrated the biological outcome of BAFF blockade in BXSB murine lupus model, using a soluble fusion protein consisting of human BAFF-R and human mutant IgG4 Fc. Mutation of Leu235 to Glu in IgG4 Fc eliminated antibody-dependent cell cytotoxicity (ADCC) and complement lysis activity, and generated a pro...

  4. Early Postnatal B Cell Ontogeny and Antibody Repertoire Maturation in the Opossum, Monodelphis domestica

    OpenAIRE

    Wang, Xinxin; Sharp, Alana R.; Miller, Robert D.

    2012-01-01

    Marsupials are a lineage of mammals noted for giving birth to highly altricial young, which complete much of their “fetal” development externally attached to a teat. Postnatal B cell ontogeny and diversity was investigated in a model marsupial species, the gray short-tailed opossum, Monodelphis domestica. The results support the initiation of B cell development late in gestation and progressing into the first two weeks of postnatal life. Transcription of CD79a and CD79b was detected in embryo...

  5. Increased B Cell ADAM10 in Allergic Patients and Th2 Prone Mice.

    Directory of Open Access Journals (Sweden)

    Lauren Folgosa Cooley

    Full Text Available ADAM10, as the sheddase of the low affinity IgE receptor (CD23, promotes IgE production and thus is a unique target for attenuating allergic disease. Herein, we describe that B cell levels of ADAM10, specifically, are increased in allergic patients and Th2 prone WT mouse strains (Balb/c and A/J. While T cell help augments ADAM10 expression, Balb WT B cells exhibit increased ADAM10 in the naïve state and even more dramatically increased ADAM10 after anti-CD40/IL4 stimulation compared C57 (Th1 prone WT B cells. Furthermore, ADAM17 and TNF are reduced in allergic patients and Th2 prone mouse strains (Balb/c and A/J compared to Th1 prone controls. To further understand this regulation, ADAM17 and TNF were studied in C57Bl/6 and Balb/c mice deficient in ADAM10. C57-ADAM10B-/- were more adept at increasing ADAM17 levels and thus TNF cleavage resulting in excess follicular TNF levels and abnormal secondary lymphoid tissue architecture not noted in Balb-ADAM10B-/-. Moreover, the level of B cell ADAM10 as well as Th context is critical for determining IgE production potential. Using a murine house dust mite airway hypersensitivity model, we describe that high B cell ADAM10 level in a Th2 context (Balb/c WT is optimal for disease induction including bronchoconstriction, goblet cell metaplasia, mucus, inflammatory cellular infiltration, and IgE production. Balb/c mice deficient in B cell ADAM10 have attenuated lung and airway symptoms compared to Balb WT and are actually most similar to C57 WT (Th1 prone. C57-ADAM10B-/- have even further reduced symptomology. Taken together, it is critical to consider both innate B cell levels of ADAM10 and ADAM17 as well as Th context when determining host susceptibility to allergic disease. High B cell ADAM10 and low ADAM17 levels would help diagnostically in predicting Th2 disease susceptibility; and, we provide support for the use ADAM10 inhibitors in treating Th2 disease.

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

    Directory of Open Access Journals (Sweden)

    Sabyasachi Halder

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

  7. Murine retroviruses activate B cells via interaction with toll-like receptor 4

    OpenAIRE

    Rassa, John C.; Meyers, Jennifer L.; Zhang, Yuanming; Kudaravalli, Rama; Susan R Ross

    2002-01-01

    Although most retroviruses require activated cells as their targets for infection, it is not known how this is achieved in vivo. A candidate protein for the activation of B cells by either mouse mammary tumor virus (MMTV) or murine leukemia virus is the toll-like receptor 4 (TLR4), a component of the innate immune system. MMTV caused B cell activation in C3H/HeN mice but not in C3H/HeJ or BALB/c (C.C3H Tlr4lps-d) congenic mice, both of which have a mutant TLR4 gene. This activation was indepe...

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

    OpenAIRE

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

    2014-01-01

    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 m...

  9. Regulation of Anti-DNA B Cells in Recombination-activating Gene–deficient Mice

    OpenAIRE

    Xu, Hui; Li, Hui; Suri-Payer, Elisabeth; Hardy, Richard R.; Weigert, Martin

    1998-01-01

    Anti-DNA antibodies are regulated in normal individuals but are found in high concentration in the serum of systemic lupus erythematosus (SLE) patients and the MRL lpr/lpr mouse model of SLE. We previously studied the regulation of anti–double-stranded (ds)DNA and anti–single-stranded (ss)DNA B cells in a nonautoimmune background by generating mice carrying immunoglobulin transgenes coding for anti-DNAs derived from MRL lpr/lpr. Anti-dsDNA B cells undergo receptor editing, but anti-ssDNA B ce...

  10. Anti–DNA B Cells in MRL/lpr Mice Show Altered Differentiation and Editing Pattern

    OpenAIRE

    Li, Yijin; Li, Hui; Ni, Dongyao; Weigert, Martin

    2002-01-01

    We have studied the regulation of anti–DNA B cells in transgenic mice with a heavy chain transgene (3H9H/56R). This transgene codes for a heavy chain that forms anti–double-stranded DNA (dsDNA) antibody when paired with most members of the endogenous Vκ repertoire, but certain L chains, referred to as Vκ editors, do not sustain dsDNA binding in combination with 3H9H/56R. In the nonautoimmune 3H9H/56R BALB/c, most B cells generated do not bind DNA because the transgene itself is edited or is a...

  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. Acute Hepatitis A Induction of Precursor B-Cell Acute Lymphoblastic Leukemia: A Causal Relationship?

    OpenAIRE

    Senadhi, V.; Emuron, D.; R. Gupta

    2010-01-01

    Background Precursor B-cell acute lymphoblastic leukemia accounts for 2% of all lymphoid neoplasms in the United States and occurs most frequently in childhood, but can also occur in adults with a median age of 39 years. It is more commonly seen in males and in Caucasians. Case Report We present a case of a 51-year-old Caucasian female with the development of precursor B-cell acute lymphoblastic leukemia after suffering acute hepatitis A 4 weeks prior to her diagnosis. She presented with mala...

  13. Individualized leukemia cell-population profiles in common B-cell acute lymphoblastic leukemia patients

    OpenAIRE

    Xian-Ming Mo; Hong Xu; Ting-Ting Zeng; Neng-Gang Jiang; Yong-Qian Jia; Jing-Tao Dong; Jian-Hua Yu; Wen-Tong Meng

    2013-01-01

    Immunophenotype is critical for diagnosing common B-cell acute lymphoblastic leukemia (common ALL) and detecting minimal residual disease. We developed a protocol to explore the immunophenotypic profiles of common ALL based on the expression levels of the antigens associated with B lymphoid development, including IL-7R alpha (CD127), cytoplasmic CD79a (cCD79a), CD19, VpreB (CD179a), and sIgM, which are successive and essential for progression of B cells along their developmental pathway. Anal...

  14. B Cell Receptor Activation Predominantly Regulates AKT-mTORC1/2 Substrates Functionally Related to RNA Processing

    Science.gov (United States)

    Mohammad, Dara K.; Ali, Raja H.; Turunen, Janne J.; Nore, Beston F.; Smith, C. I. Edvard

    2016-01-01

    Protein kinase B (AKT) phosphorylates numerous substrates on the consensus motif RXRXXpS/T, a docking site for 14-3-3 interactions. To identify novel AKT-induced phosphorylation events following B cell receptor (BCR) activation, we performed proteomics, biochemical and bioinformatics analyses. Phosphorylated consensus motif-specific antibody enrichment, followed by tandem mass spectrometry, identified 446 proteins, containing 186 novel phosphorylation events. Moreover, we found 85 proteins with up regulated phosphorylation, while in 277 it was down regulated following stimulation. Up regulation was mainly in proteins involved in ribosomal and translational regulation, DNA binding and transcription regulation. Conversely, down regulation was preferentially in RNA binding, mRNA splicing and mRNP export proteins. Immunoblotting of two identified RNA regulatory proteins, RBM25 and MEF-2D, confirmed the proteomics data. Consistent with these findings, the AKT-inhibitor (MK-2206) dramatically reduced, while the mTORC-inhibitor PP242 totally blocked phosphorylation on the RXRXXpS/T motif. This demonstrates that this motif, previously suggested as an AKT target sequence, also is a substrate for mTORC1/2. Proteins with PDZ, PH and/or SH3 domains contained the consensus motif, whereas in those with an HMG-box, H15 domains and/or NF-X1-zinc-fingers, the motif was absent. Proteins carrying the consensus motif were found in all eukaryotic clades indicating that they regulate a phylogenetically conserved set of proteins. PMID:27487157

  15. The microRNA miR-148a functions as a critical regulator of B cell tolerance and autoimmunity.

    Science.gov (United States)

    Gonzalez-Martin, Alicia; Adams, Brian D; Lai, Maoyi; Shepherd, Jovan; Salvador-Bernaldez, Maria; Salvador, Jesus M; Lu, Jun; Nemazee, David; Xiao, Changchun

    2016-04-01

    Autoreactive B cells have critical roles in a large diversity of autoimmune diseases, but the molecular pathways that control these cells remain poorly understood. We performed an in vivo functional screen of a lymphocyte-expressed microRNA library and identified miR-148a as a potent regulator of B cell tolerance. Elevated miR-148a expression impaired B cell tolerance by promoting the survival of immature B cells after engagement of the B cell antigen receptor by suppressing the expression of the autoimmune suppressor Gadd45α, the tumor suppressor PTEN and the pro-apoptotic protein Bim. Furthermore, increased expression of miR-148a, which occurs frequently in patients with lupus and lupus-prone mice, facilitated the development of lethal autoimmune disease in a mouse model of lupus. Our studies demonstrate a function for miR-148a as a regulator of B cell tolerance and autoimmunity. PMID:26901150

  16. Analysis by Flow Cytometry of B-Cell Activation and Antibody Responses Induced by Toll-Like Receptors.

    Science.gov (United States)

    Pone, Egest J

    2016-01-01

    Toll-like receptors (TLRs) are expressed in B lymphocytes and contribute to B-cell activation, antibody responses, and their maturation. TLR stimulation of mouse B cells induces class switch DNA recombination (CSR) to isotypes specified by cytokines, and also induces formation of IgM(+) as well as class-switched plasma cells. B-cell receptor (BCR) signaling, while on its own inducing limited B-cell proliferation and no CSR, can enhance CSR driven by TLRs. Particular synergistic or antagonistic interactions among TLR pathways, BCR, and cytokine signaling can have important consequences for B-cell activation, CSR, and plasma cell formation. This chapter outlines protocols for the induction and analysis of B-cell activation and antibody production by TLRs with or without other stimuli. PMID:26803633

  17. Transmembrane signaling through major histocompatibility complex (MHC) encoded molecules

    International Nuclear Information System (INIS)

    The importance of the major histocompatibility complex (MHC) encoded molecules has traditionally been ascribed to the role these molecules play as restriction elements for T lymphocytes. This is, in order for T cell activation to occur the T cell must recognize antigen in association with MHC molecules. More controversial, however, is the potential role MHC molecules play as signal transducing receptors/acceptors to the B lymphocyte. In other words, do class II MHC molecules (Ia antigens) actively transduce a signal to the B cell which drives its differentiation into an antibody secreting cell? Two approaches to this question are described. The first involves biochemical characterization of those molecules which consistently copurify with I-A/sup k/ by two dimensional gel electrophoresis. The second approach utilizes two types of analyses: first, an examination of the biochemical changes which occur in the cell as a result of Ia ligation; and second, analysis of changes in the B cell's physiological response as a result of Ia perturbation. Molecules were examined which may couple the antigen binding event in the B lymphocyte to the antigen driven signal transduction cascade which ultimately leads to immunoglobulin secretion. In these experiments, cells were labelled with [32P] and stimulated cells with phorbol myristate acetate. The membrane form of immunoglobulin was then isolated from detergent lysates of whole cells and passed over an anti-k affinity column. The eluates were analyzed by SDS-PAGE

  18. Eicosapentaenoic and docosahexaenoic acid ethyl esters differentially enhance B-cell activity in murine obesity[S

    OpenAIRE

    Teague, Heather; Harris, Mitchel; Fenton, Jenifer; Lallemand, Perrine; Shewchuk, Brian M.; Shaikh, Saame Raza

    2014-01-01

    EPA and DHA are not biologically equivalent; however, their individual activity on B cells is unknown. We previously reported fish oil enhanced murine B-cell activity in obesity. To distinguish between the effects of EPA and DHA, we studied the ethyl esters of EPA and DHA on murine B-cell function as a function of time. We first demonstrate that EPA and DHA maintained the obese phenotype, with no improvements in fat mass, adipose inflammatory cytokines, fasting insulin, or glucose clearance. ...

  19. B-cell depletion in SLE: clinical and trial experience with rituximab and ocrelizumab and implications for study design

    OpenAIRE

    Reddy, V; Jayne, D; Close, D.; Isenberg, D

    2013-01-01

    B cells are believed to be central to the disease process in systemic lupus erythematosus (SLE), making them a target for new therapeutic intervention. In recent years there have been many publications regarding the experience in SLE of B-cell depletion utilising rituximab, an anti-CD20 mAb that temporarily depletes B cells, reporting promising results in uncontrolled open studies and in routine clinical use. However, the two large randomised controlled trials in extra-renal lupus (EXPLORER s...

  20. APRIL stimulates NF-κB-mediated HoxC4 induction for AID expression in mouse B cells

    OpenAIRE

    Park, Seok-Rae; Kim, Pyeung-Hyeun; Lee, Kyu-Seon; Lee, Sang-Hoon; Seo, Goo-Young; Yoo, Yung-Choon; Lee, Junglim; Casali, Paolo

    2012-01-01

    Activation-induced cytidine deaminase (AID) plays a key role in B cell immunoglobulin (Ig) class switch recombination (CSR) and somatic hypermutation (SHM). We have previously reported that the highly conserved homeodomain HoxC4 transcription factor binds to the Aicda (AID gene) promoter to induce AID expression. Here, we investigated the regulation of HoxC4 transcription by a proliferation-inducing ligand (APRIL) and B cell-activating factor belonging to the TNF family (BAFF) in mouse B cell...

  1. Innate lymphoid cells integrate stromal and immunological signals to enhance antibody production by splenic marginal zone B cells

    OpenAIRE

    Magri, Giuliana; Miyajima, Michio; Bascones, Sabrina; Mortha, Arthur; Puga, Irene; Cassis, Linda; Barra, Carolina M; Comerma, Laura; Chudnovskiy, Aleksey; Gentile, Maurizio; Llige, David; Cols, Montserrat; Serrano, Sergi; Aróstegui, Juan Ignacio; Juan, Manel

    2014-01-01

    Innate lymphoid cells (ILCs) regulate stromal, epithelial and immune cells, but their impact on B cells remains unclear. We identified RORγt+ ILCs nearby the marginal zone (MZ), a splenic compartment containing innate-like B cells that respond to circulating T cell-independent (TI) antigens. Spenic ILCs established a bidirectional crosstalk with MAdCAM-1+ marginal reticular cells by providing tumor necrosis factor (TNF) and lymphotoxin, and activated MZ B cells via BAFF, CD40 ligand and the N...

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

    Directory of Open Access Journals (Sweden)

    Alain Bordon

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

  3. Deficiency of the B Cell-Activating Factor Receptor Results in Limited CD169+ Macrophage Function during Viral Infection

    OpenAIRE

    Xu, Haifeng C.; Huang, Jun; Khairnar, Vishal; Duhan, Vikas; Pandyra, Aleksandra A; Grusdat, Melanie; Shinde, Prashant; McIlwain, David R.; Maney, Sathish Kumar; Gommerman, Jennifer; Löhning, Max; Ohashi, Pamela S.; Mak, Tak W; Pieper, Kathrin; Sic, Heiko

    2015-01-01

    The B cell-activating factor (BAFF) is critical for B cell development and humoral immunity in mice and humans. While the role of BAFF in B cells has been widely described, its role in innate immunity remains unknown. Using BAFF receptor (BAFFR)-deficient mice, we characterized BAFFR-related innate and adaptive immune functions following infection with vesicular stomatitis virus (VSV) and lymphocytic choriomeningitis virus (LCMV). We identified a critical role for BAFFR signaling in the gener...

  4. Interleukin 5, a T-cell-derived B-cell differentiation factor also induces cytotoxic T lymphocytes.

    OpenAIRE

    Takatsu, K; Kikuchi, Y; Takahashi, T.; Honjo, T; Matsumoto, M.; Harada, N.; Yamaguchi, N.; Tominaga, A

    1987-01-01

    We describe an interleukin, termed interleukin 5, that is the recombinant product previously referred to as T-cell-replacing factor (TRF), B-cell growth factor II (BCGF II), or killer-helper factor (KHF). TRF has been defined as a T-cell-derived lymphokine that acts on activated B cells as a B-cell differentiation factor. We have previously demonstrated that TRF is identical to BCGF II and induces expression of receptors for interleukin 2 (IL-2) on activated B cells. We also have reported tha...

  5. A simplified method for Ca2+ flux measurement on isolated human B cells that uses flow cytometry.

    OpenAIRE

    Gergely, L.; Cook, L.; Agnello, V

    1997-01-01

    A method for Ca2+ flux measurement on isolated human peripheral B cells that uses flow cytometry is described. B cells were isolated by anti-CD19 magnetic bead sorting, and Ca2+ flux was measured with the fluo-3 reagent on a standard single-laser flow cytometer. The response of B-cell stimulation by anti-immunoglobulin B (anti-IgM), anti-IgD, protein A, concanavalin A, and ionomycin was determined. Percentage of responder B cells, the level of Ca2+, and the time of peak stimulation were measu...

  6. B-Cell Activating Factor (BAFF) is elevated in Chronic Granulomatous Disease

    OpenAIRE

    Matharu, Kabir; Zarember, Kol A.; Marciano, Beatriz E.; Kuhns, Douglas B; Spalding, Christine; Garofalo, Mary; DiMaggio, Thomas; Estwick, Tyra; Huang, Chiung-yu; Fink, Danielle; Priel, Debra L.; Fleisher, Thomas A.; Holland, Steven M.; Malech, Harry L.; Gallin, John I.

    2013-01-01

    Chronic Granulomatous Disease (CGD) is an inherited defect in superoxide production leading to life-threatening infections, granulomas, and, possibly, abnormal immunoglobulin concentrations. We investigated whether factors controlling antibody production, such as B-cell activating factor (BAFF), were altered in CGD. CGD subjects had significantly increased mean (2.3-fold, p

  7. Molecular characterization of neoplastic and normal "sister" lymphoblastoid B-cell lines from chronic lymphocytic leukemia

    DEFF Research Database (Denmark)

    Lanemo Myhrinder, Anna; Hellqvist, Eva; Bergh, Ann-Charlotte;

    2013-01-01

    ) and DNA/short tandem repeat (STR) fingerprinting. Innate B-cell features, i.e. natural Ab production and CD5 receptors, were present in most CLL cell lines, but in none of the normal LCLs. This panel of immortalized CLL-derived cell lines is a valuable reference representing a renewable source of...

  8. Ocular Adnexal Diffuse Large B-cell LymphomaA Multicenter International Study

    DEFF Research Database (Denmark)

    Munch-Petersen, Helga D; Rasmussen, Peter K; Coupland, Sarah E;

    2015-01-01

    IMPORTANCE: The clinical features of diffuse large B-cell lymphoma (DLBCL) subtype of ocular adnexal lymphoma have not previously been evaluated in a large cohort to our knowledge. OBJECTIVE: To investigate the clinical features of ocular adnexal DLBCL (OA-DLBCL). DESIGN, SETTING, AND PARTICIPANT...

  9. Osteoclast cytomorphometry demonstrates an abnormal population in B cell malignancies but not in multiple myeloma.

    Science.gov (United States)

    Chappard, D; Rossi, J F; Bataille, R; Alexandre, C

    1991-01-01

    Increased bone resorption in the vicinity of myeloma cells is mediated by local stimulating factors. Other malignancies of the B cell lineage are also able to produce resorbing factors responsible for increased bone resorption. We have studied three groups of subjects: 10 patients with overt multiple myeloma, 10 patients with a B cell malignancy, and 10 healthy human subjects as controls. Patients were studied at the time of diagnosis and had a transiliac bone biopsy. Osteoclasts were evident on histological sections by their acid phosphatase activity. A software was developed on an automatic image analyzer (Leitz TAS+) for measuring the maximal Feret's diameter (Oc.Le) of each osteoclast (corresponding to the osteoclast length). The histogram of Oc.Le frequency distribution was supplied in each group. In myeloma patients, the Oc.Le frequency distribution was similar to that in normal subjects and showed the histogram to be asymetric with a positive skew (maximum peak at 20-25 microns). With a graphical analysis, this distribution was shown to follow a lognormal distribution corresponding to a homogeneous osteoclast population. In other B cell malignancies, Oc.Le displayed a bimodal distribution with a peak at 20-25 microns and a lower peak at 10-15 microns. The graphical analysis showed that small (mononucleated?) osteoclasts are present in B cell malignancies with normal osteoclasts. This might reflect the secretion of different soluble factors by malignant cells of the B lymphocyte lineage. PMID:1706639

  10. miR-155 as a Biomarker in B-Cell Malignancies

    Science.gov (United States)

    Due, Hanne; Svendsen, Pernille; Bødker, Julie Støve; Schmitz, Alexander; Bøgsted, Martin; Johnsen, Hans Erik; El-Galaly, Tarec Christoffer; Roug, Anne Stidsholt; Dybkær, Karen

    2016-01-01

    MicroRNAs have the potential to be useful biomarkers in the development of individualized treatment since they are easy to detect, are relatively stable during sample handling, and are important determinants of cellular processes controlling pathogenesis, progression, and response to treatment of several types of cancers including B-cell malignancies. miR-155 is an oncomiR with a crucial role in tumor initiation and development of several B-cell malignancies. The present review elucidates the potential of miR-155 as a diagnostic, prognostic, or predictive biomarker in B-cell malignancies using a systematic search strategy to identify relevant literature. miR-155 was upregulated in several malignancies compared to nonmalignant controls and overexpression of miR-155 was further associated with poor prognosis. Elevated expression of miR-155 shows potential as a diagnostic and prognostic biomarker in diffuse large B-cell lymphoma and chronic lymphocytic leukemia. Additionally, in vitro and in vivo studies suggest miR-155 as an efficient therapeutic target, supporting its oncogenic function. The use of inhibiting anti-miR structures indicates promising potential as novel anticancer therapeutics. Reports from 53 studies prove that miR-155 has the potential to be a molecular tool in personalized medicine. PMID:27294145

  11. Ocrelizumab: a step forward in the evolution of B-cell therapy.

    Science.gov (United States)

    Kausar, Fariha; Mustafa, Khader; Sweis, Ghaleb; Sawaqed, Ray; Alawneh, Khaldoon; Salloum, Rafah; Badaracco, Maria; Niewold, Timothy B; Sweiss, Nadera J

    2009-07-01

    Recent advances in our understanding of B-cell dysregulation and its important link to autoimmunity have brought about a radical change in the management of autoimmune diseases. Over the past few years, encouraging data from several clinical trials of rituximab, a chimeric anti-CD20 antibody, have led to its approval for use in rheumatoid arthritis (RA). These data, regarding clinical efficacy, safety, improved patient-reported outcomes and cost-effectiveness with the use of rituximab in patients with RA, have led to the exploration of other agents targeting B-cell functions. Ocrelizumab, a novel humanized anti-CD20 antibody, has shown clinical efficacy and safety in a recently reported trial in patients with RA. Future clinical trials will help evaluate further the role of ocrelizumab in RA and its potential use in other autoimmune diseases. This review describes current understanding of B-cell therapy, the role of rituximab in the treatment of RA and the evolving role of ocrelizumab as a B-cell-targeted therapy. PMID:19463076

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

    Directory of Open Access Journals (Sweden)

    Pilar M. Dominguez

    2015-09-01

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

  13. Early postnatal B cell ontogeny and antibody repertoire maturation in the opossum, Monodelphis domestica.

    Directory of Open Access Journals (Sweden)

    Xinxin Wang

    Full Text Available Marsupials are a lineage of mammals noted for giving birth to highly altricial young, which complete much of their "fetal" development externally attached to a teat. Postnatal B cell ontogeny and diversity was investigated in a model marsupial species, the gray short-tailed opossum, Monodelphis domestica. The results support the initiation of B cell development late in gestation and progressing into the first two weeks of postnatal life. Transcription of CD79a and CD79b was detected in embryonic tissue prior to birth, while immunoglobulin heavy chain locus transcription was not detected until the first postnatal 24 hours. Transcription of the Ig light chains was not detected until postnatal day 7 at the earliest. The predicted timing of the earliest appearance of mature B cells and completion of gene rearrangements is consistent with previous analyses on the timing of endogenous antibody responses in newborn marsupials. The diversity of early B cell IgH chains is limited, as has been seen in fetal humans and mice, but lacks bias in the gene segments used to encode the variable domains. Newborn light chain diversity is, from the start, comparable to that of the adult, consistent with an earlier hypothesis that light chains contribute extensively to antibody diversity in this species.

  14. The tumor microenvironment shapes hallmarks of mature B-cell malignancies.

    Science.gov (United States)

    Shain, K H; Dalton, W S; Tao, J

    2015-09-01

    B-cell tumorigenesis results from a host of known and unknown genetic anomalies, including non-random translocations of genes that normally function as determinants of cell proliferation or cell survival to regions juxtaposed to active immunoglobulin heavy chain enhancer elements, chromosomal aneuploidy, somatic mutations that further affect oncogenic signaling and loss of heterozygosity of tumor-suppressor genes. However, it is critical to recognize that even in the setting of a genetic disease, the B-cell/plasma cell tumor microenvironment (TME) contributes significantly to malignant transformation and pathogenesis. Over a decade ago, we proposed the concept of cell adhesion-mediated drug resistance to delineate a form of TME-mediated drug resistance that protects hematopoietic tumor cells from the initial effect of diverse therapies. In the interim, it has been increasingly appreciated that TME also contributes to tumor initiation and progression through sustained growth/proliferation, self-renewal capacity, immune evasion, migration and invasion as well as resistance to cell death in a host of B-cell malignancies, including mantle cell lymphoma, diffuse large B-cell lymphoma, Waldenstroms macroglobulinemia, chronic lymphocytic leukemia and multiple myeloma. Within this review, we propose that TME and the tumor co-evolve as a consequence of bidirectional signaling networks. As such, TME represents an important target and should be considered integral to tumor progression and drug response. PMID:25639873

  15. Aging affects B-cell antigen receptor repertoire diversity in primary and secondary lymphoid tissues.

    Science.gov (United States)

    Tabibian-Keissar, Hilla; Hazanov, Lena; Schiby, Ginette; Rosenthal, Noemie; Rakovsky, Aviya; Michaeli, Miri; Shahaf, Gitit Lavy; Pickman, Yishai; Rosenblatt, Kinneret; Melamed, Doron; Dunn-Walters, Deborah; Mehr, Ramit; Barshack, Iris

    2016-02-01

    The elderly immune system is characterized by reduced responses to infections and vaccines, and an increase in the incidence of autoimmune diseases and cancer. Age-related deficits in the immune system may be caused by peripheral homeostatic pressures that limit bone marrow B-cell production or migration to the peripheral lymphoid tissues. Studies of peripheral blood B-cell receptor spectratypes have shown that those of the elderly are characterized by reduced diversity, which is correlated with poor health status. In the present study, we performed for the first time high-throughput sequencing of immunoglobulin genes from archived biopsy samples of primary and secondary lymphoid tissues in old (74 ± 7 years old, range 61-89) versus young (24 ± 5 years old, range 18-45) individuals, analyzed repertoire diversities and compared these to results in peripheral blood. We found reduced repertoire diversity in peripheral blood and lymph node repertoires from old people, while in the old spleen samples the diversity was larger than in the young. There were no differences in somatic hypermutation characteristics between age groups. These results support the hypothesis that age-related immune frailty stems from altered B-cell homeostasis leading to narrower memory B-cell repertoires, rather than changes in somatic hypermutation mechanisms. PMID:26614343

  16. Diffuse Large B Cell Lymphoma in a Patient with Hypocomplementemic Urticarial Vasculitis

    Directory of Open Access Journals (Sweden)

    Calvo-Romero J

    2003-01-01

    Full Text Available Hypocomplementemic urticarial vasculitis (HUV is known to be associated with malignancies. Urticarial vasculitis has been linked to lymphomas, but to our knowledge, the association of HUV and non-Hodgkin lymphoma has not been described so far. A patient with HUV who developed 10 years later a diffuse large B cell lymphoma is reported here.

  17. Diffuse Large B Cell Lymphoma in a Patient with Hypocomplementemic Urticarial Vasculitis

    OpenAIRE

    Calvo-Romero J

    2003-01-01

    Hypocomplementemic urticarial vasculitis (HUV) is known to be associated with malignancies. Urticarial vasculitis has been linked to lymphomas, but to our knowledge, the association of HUV and non-Hodgkin lymphoma has not been described so far. A patient with HUV who developed 10 years later a diffuse large B cell lymphoma is reported here.

  18. Genetic Landscapes of Relapsed and Refractory Diffuse Large B-Cell Lymphomas

    DEFF Research Database (Denmark)

    Morin, Ryan D; Assouline, Sarit; Alcaide, Miguel; Mohajeri, Arezoo; Johnston, Rebecca L; Chong, Lauren; Grewal, Jasleen; Yu, Stephen; Fornika, Daniel; Bushell, Kevin; Nielsen, Torsten Holm; Petrogiannis-Haliotis, Tina; Crump, Michael; Tosikyan, Axel; Grande, Bruno M; MacDonald, David; Rousseau, Caroline; Bayat, Maryam; Sesques, Pierre; Froment, Remi; Albuquerque, Marco; Monczak, Yury; Oros, Kathleen Klein; Greenwood, Celia; Riazalhosseini, Yasser; Arseneault, Madeleine; Camlioglu, Errol; Constantin, André; Pan-Hammarstrom, Qiang; Peng, Roujun; Mann, Koren K; Johnson, Nathalie A

    2015-01-01

    PURPOSE: Relapsed or refractory diffuse large B-cell lymphoma (rrDLBCL) is fatal in 90% of patients, and yet little is known about its biology. EXPERIMENTAL DESIGN: Using exome sequencing, we characterized the mutation profiles of 38 rrDLBCL biopsies obtained at the time of progression after...

  19. Frequent disruption of the RB1 pathway in diffuse large B cell lymphoma

    DEFF Research Database (Denmark)

    Møller, M B; Kania, Per Walter; Ino, Y;

    2000-01-01

    In the present study, we analysed 34 de novo diffuse large B cell lymphoma (DLCL) from a population-based lymphoma registry for alterations of the RB1 pathway at the genetic (RB1 and CDK4) and protein (pRb, cyclin D1, cyclin D3, CDK4, and E2F-1) level. The results were correlated with the data fr...

  20. Chemokine receptor expression on B cells and effect of interferon-beta in multiple sclerosis

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke; Roed, Hanne; Sellebjerg, Finn

    We investigated the B-cell expression of chemokine receptors CXCR3, CXCR5 and CCR5 in the blood and cerebrospinal fluid (CSF) from patients in relapse of multiple sclerosis (MS) and in neurological controls. Chemokine receptor expression was also studied in interferon-beta-treated patients with r...