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Sample records for human dc cell

  1. slan/M-DC8+ cells constitute a distinct subset of dendritic cells in human tonsils.

    Science.gov (United States)

    Micheletti, Alessandra; Finotti, Giulia; Calzetti, Federica; Lonardi, Silvia; Zoratti, Elisa; Bugatti, Mattia; Stefini, Stefania; Vermi, William; Cassatella, Marco A

    2016-01-05

    Human blood dendritic cells (DCs) include three main distinct subsets, namely the CD1c+ and CD141+ myeloid DCs (mDCs) and the CD303+ plasmacytoid DCs (pDCs). More recently, a population of slan/M-DC8+ cells, also known as "slanDCs", has been described in blood and detected even in inflamed secondary lymphoid organs and non-lymphoid tissues. Nevertheless, hallmarks of slan/M-DC8+ cells in tissues are poorly defined. Herein, we report a detailed characterization of the phenotype and function of slan/M-DC8+ cells present in human tonsils. We found that tonsil slan/M-DC8+ cells represent a unique DC cell population, distinct from their circulating counterpart and also from all other tonsil DC and monocyte/macrophage subsets. Phenotypically, slan/M-DC8+ cells in tonsils display a CD11c+HLA-DR+CD14+CD11bdim/negCD16dim/negCX3CR1dim/neg marker repertoire, while functionally they exhibit an efficient antigen presentation capacity and a constitutive secretion of TNFα. Notably, such DC phenotype and functions are substantially reproduced by culturing blood slan/M-DC8+ cells in tonsil-derived conditioned medium (TDCM), further supporting the hypothesis of a full DC-like differentiation program occurring within the tonsil microenvironment. Taken together, our data suggest that blood slan/M-DC8+ cells are immediate precursors of a previously unrecognizedcompetent DC subset in tonsils, and pave the way for further characterization of slan/M-DC8+ cells in other tissues.

  2. Role of DC-SIGN in Lassa virus entry into human dendritic cells.

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    Goncalves, Ana-Rita; Moraz, Marie-Laurence; Pasquato, Antonella; Helenius, Ari; Lozach, Pierre-Yves; Kunz, Stefan

    2013-11-01

    The arenavirus Lassa virus (LASV) causes a severe hemorrhagic fever with high mortality in humans. Antigen-presenting cells, in particular dendritic cells (DCs), are early and preferred targets of LASV, and their productive infection contributes to the virus-induced immunosuppression observed in fatal disease. Here, we characterized the role of the C-type lectin DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) in LASV entry into primary human DCs using a chimera of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) expressing the LASV glycoprotein (rLCMV-LASVGP). We found that differentiation of human primary monocytes into DCs enhanced virus attachment and entry, concomitant with the upregulation of DC-SIGN. LASV and rLCMV-LASVGP bound to DC-SIGN via mannose sugars located on the N-terminal GP1 subunit of LASVGP. We provide evidence that DC-SIGN serves as an attachment factor for rLCMV-LASVGP in monocyte-derived immature dendritic cells (MDDC) and can accelerate the capture of free virus. However, in contrast to the phlebovirus Uukuniemi virus (UUKV), which uses DC-SIGN as an authentic entry receptor, productive infection with rLCMV-LASVGP was less dependent on DC-SIGN. In contrast to the DC-SIGN-mediated cell entry of UUKV, entry of rLCMV-LASVGP in MDDC was remarkably slow and depended on actin, indicating the use of different endocytotic pathways. In sum, our data reveal that DC-SIGN can facilitate cell entry of LASV in human MDDC but that its role seems distinct from the function as an authentic entry receptor reported for phleboviruses.

  3. DC-SIGN Facilitates Fusion of Dendritic Cells with Human T-Cell Leukemia Virus Type 1-Infected Cells

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    Ceccaldi, Pierre-Emmanuel; Delebecque, Frédéric; Prevost, Marie-Christine; Moris, Arnaud; Abastado, Jean-Pierre; Gessain, Antoine; Schwartz, Olivier; Ozden, Simona

    2006-01-01

    Interactions between the oncogenic retrovirus human T-cell leukemia virus type 1 (HTLV-1) and dendritic cells (DCs) are poorly characterized. We show here that monocyte-derived DCs form syncytia and are infected upon coculture with HTLV-1-infected lymphocytes. We examined the role of DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), a C-type lectin expressed in DCs, in HTLV-1-induced syncytium formation. DC-SIGN is known to bind with high affinity to various viral envelope glycoproteins, including human immunodeficiency virus (HIV) and hepatitis C virus, as well as to the cellular receptors ICAM-2 and ICAM-3. After cocultivating DCs and HTLV-1-infected cells, we found that anti-DC-SIGN monoclonal antibodies (MAbs) were able to decrease the number and size of HTLV-1-induced syncytia. Moreover, expression of the lectin in epithelial-cell lines dramatically enhanced the ability to fuse with HTLV-1-positive cells. Interestingly, in contrast to the envelope (Env) glycoproteins of HIV and other viruses, that of HTLV-1 does not bind directly to DC-SIGN. The facilitating role of the lectin in HTLV-1 syncytium formation is mediated by its interaction with ICAM-2 and ICAM-3, as demonstrated by use of MAbs directed against these adhesion molecules. Altogether, our results indicate that DC-SIGN facilitates HTLV-1 infection and fusion of DCs through an ICAM-dependent mechanism. PMID:16641270

  4. FastDC derived from human monocytes within 48 h effectively prime tumor antigen-specific cytotoxic T cells.

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    Dauer, Marc; Schad, Katharina; Herten, Jan; Junkmann, Jana; Bauer, Christian; Kiefl, Rosemarie; Endres, Stefan; Eigler, Andreas

    2005-07-01

    Previously, we have shown that dendritic cells (DCs) with full T-cell stimulatory capacity can be derived from human monocytes after 48 h of in vitro culture (FastDC). Compared to a standard 7-day protocol, this new strategy not only reduces the time span and the amount of recombinant cytokines required, but may also resemble DC development in vivo more closely. Using a melanoma antigen model, we show here that FastDC prime CTL responses against tumor antigens as effectively as standard monocyte-derived DCs (moDCs). FastDC and moDCs derived from monocytes of HLA-A2(+) donors were loaded with the melanoma-associated, HLA-A(*)0201-restricted peptide Melan-A and cocultured with autologous CD3(+) T cells. After two weekly restimulations with freshly prepared, peptide-loaded FastDC or moDCs, binding of CD8(+) T cells to fluorescently labeled MHC-I/Melan-A-peptide complexes and intracellular cytokine staining revealed that the two DC preparations had an equal capacity to prime Melan-A-specific, IFN-gamma producing CD8(+) T cells. CTLs derived from cocultures with FastDC lysed Melan-A-loaded T2 cells even more effectively than CTLs primed by moDCs. Comparative analysis also revealed that FastDC possess an equal capacity to migrate in response to the chemokine receptor CCR-7 ligand 6Ckine. Importantly, DCs can be generated with higher yield and purity using the FastDC-protocol. The reliability and efficacy of this new strategy for DC development from monocytes may facilitate clinical investigation of DC-based tumor immunotherapy.

  5. Lentivirus-mediated RNA interference of DC-SIGN expression inhibits human immunodeficiency virus transmission from dendritic cells to T cells.

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    Arrighi, Jean-François; Pion, Marjorie; Wiznerowicz, Maciej; Geijtenbeek, Teunis B; Garcia, Eduardo; Abraham, Shahnaz; Leuba, Florence; Dutoit, Valérie; Ducrey-Rundquist, Odile; van Kooyk, Yvette; Trono, Didier; Piguet, Vincent

    2004-10-01

    In the early events of human immunodeficiency virus type 1 (HIV-1) infection, immature dendritic cells (DCs) expressing the DC-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) receptor capture small amounts of HIV-1 on mucosal surfaces and spread viral infection to CD4(+) T cells in lymph nodes (22, 34, 45). RNA interference has emerged as a powerful tool to gain insight into gene function. For this purpose, lentiviral vectors that express short hairpin RNA (shRNA) for the delivery of small interfering RNA (siRNA) into mammalian cells represent a powerful tool to achieve stable gene silencing. In order to interfere with DC-SIGN function, we developed shRNA-expressing lentiviral vectors capable of conditionally suppressing DC-SIGN expression. Selectivity of inhibition of human DC-SIGN and L-SIGN and chimpanzee and rhesus macaque DC-SIGN was obtained by using distinct siRNAs. Suppression of DC-SIGN expression inhibited the attachment of the gp120 envelope glycoprotein of HIV-1 to DC-SIGN transfectants, as well as transfer of HIV-1 to target cells in trans. Furthermore, shRNA-expressing lentiviral vectors were capable of efficiently suppressing DC-SIGN expression in primary human DCs. DC-SIGN-negative DCs were unable to enhance transfer of HIV-1 infectivity to T cells in trans, demonstrating an essential role for the DC-SIGN receptor in transferring infectious viral particles from DCs to T cells. The present system should have broad applications for studying the function of DC-SIGN in the pathogenesis of HIV as well as other pathogens also recognized by this receptor.

  6. Echinophora platyloba DC (Apiaceae crude extract induces apoptosis in human prostate adenocarcinoma cells (PC 3

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    Fatemeh Zare Shahneh

    2014-10-01

    Full Text Available Background: Prostate cancer is the second leading malignancy worldwide and the second prominent cause of cancer-related deaths among men. Therefore, there is a serious necessity for finding advanced alternative therapeutic measures against this lethal malignancy. In this article, we report the cytotoxicity and the mechanism of cell death of the methanolic extract prepared from Echinophora platyloba DC plant against human prostate adenocarcinoma PC 3 cell line and Human Umbilical Vein Endothelial Cells HUVEC cell line. Methods: Cytotoxicity and viability of the methanolic extract were assessed by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and dye exclusion assay. Cell death enzyme-linked immunosorbent assay (ELISA was employed to quantify the nucleosome production resulting from nuclear DNA fragmentation during apoptosis and determine whether the mechanism involves induction of apoptosis or necrosis. The cell death was identified as apoptosis using terminal deoxynucleotidyl transferase (TdT-mediated dUTP nick end labeling (TUNEL assay and DNA fragmentation gel electrophoresis. Results: E. platyloba could decrease cell viability in malignant cells in a dose- and time-dependent manner. The IC50 values against PC 3 were determined as 236.136 ± 12.4, 143.400 ± 7.2, and 69.383 ± 1.29 μg/ml after 24, 36, and 48 h, respectively, but there was no significant activity in HUVEC normal cell (IC50 > 800 μg/ml. Morphological characterizations and DNA laddering assay showed that the methanolic extract treated cells displayed marked apoptotic characteristics such as nuclear fragmentation, appearance of apoptotic bodies, and DNA laddering fragment. Increase in an early apoptotic population was observed in a dose-dependent manner. PC 3 cell death elicited by the extract was found to be apoptotic in nature based a clear indication of TUNEL assay and gel electrophoresis DNA fragmentation, which is a hallmark of apoptosis

  7. Lentivirus-mediated RNA interference of DC-SIGN expression inhibits human immunodeficiency virus transmission from dendritic cells to T cells.

    NARCIS (Netherlands)

    Arrighi, JF; Pion, M; Wiznerowicz, M; Geijtenbeek, T.B.H.; Garcia, E; Abraham, S.; Leuba, F; Dutoit, V; Ducrey-Rundquist, O; Kooijk, van Y.; Trono, D; Piguet, V

    2004-01-01

    In the early events of human immunodeficiency virus type 1 (HIV-1) infection, immature dendritic cells (DCs) expressing the DC-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) receptor capture small amounts of HIV-1 on mucosal surfaces and spread viral infection to CD4(+) T

  8. DC-SCRIPT Regulates IL-10 Production in Human Dendritic Cells by Modulating NF-κBp65 Activation.

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    Søndergaard, Jonas Nørskov; Poghosyan, Susanna; Hontelez, Saartje; Louche, Pauline; Looman, Maaike W G; Ansems, Marleen; Adema, Gosse J

    2015-08-15

    The balance between tolerance and immunity is important for the outcome of an infection or cancer, and dendritic cells (DCs) are key regulators of this balance. DC-specific transcript (DC-SCRIPT) is a protein expressed by DCs and has been demonstrated to suppress both TLR-mediated expression of IL-10 and glucocorticoid receptor-mediated transcription of glucocorticoid-induced leucine zipper (GILZ). Because GILZ is known to promote IL-10 production, we investigated whether these two processes are linked. Dual-knockdown and inhibition experiments demonstrated that neither GILZ nor glucocorticoid receptor play a role in TLR-induced IL-10 production after DC-SCRIPT knockdown. The NF-κB pathway is another route involved in IL-10 production after DC activation. Strikingly, inhibition of NF-κB led to a decreased TLR-mediated IL-10 production in DC-SCRIPT knockdown DCs. Moreover, DC-SCRIPT knockdown DCs showed enhanced phosphorylation, acetylation, and IL10 enhancer binding of the NF-κB subunit p65. These data demonstrate that besides nuclear receptor regulation, DC-SCRIPT also modulates activation of NF-κBp65 after TLR activation in human DCs.

  9. Porphyromonas gingivalis Evasion of Autophagy and Intracellular Killing by Human Myeloid Dendritic Cells Involves DC-SIGN-TLR2 Crosstalk

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    El-Awady, Ahmed R.; Miles, Brodie; Scisci, Elizabeth; Kurago, Zoya B.; Palani, Chithra D.; Arce, Roger M.; Waller, Jennifer L.; Genco, Caroline A.; Slocum, Connie; Manning, Matthew; Schoenlein, Patricia V.; Cutler, Christopher W.

    2015-01-01

    Signaling via pattern recognition receptors (PRRs) expressed on professional antigen presenting cells, such as dendritic cells (DCs), is crucial to the fate of engulfed microbes. Among the many PRRs expressed by DCs are Toll-like receptors (TLRs) and C-type lectins such as DC-SIGN. DC-SIGN is targeted by several major human pathogens for immune-evasion, although its role in intracellular routing of pathogens to autophagosomes is poorly understood. Here we examined the role of DC-SIGN and TLRs in evasion of autophagy and survival of Porphyromonas gingivalis in human monocyte-derived DCs (MoDCs). We employed a panel of P. gingivalis isogenic fimbriae deficient strains with defined defects in Mfa-1 fimbriae, a DC-SIGN ligand, and FimA fimbriae, a TLR2 agonist. Our results show that DC-SIGN dependent uptake of Mfa1+P. gingivalis strains by MoDCs resulted in lower intracellular killing and higher intracellular content of P. gingivalis. Moreover, Mfa1+P. gingivalis was mostly contained within single membrane vesicles, where it survived intracellularly. Survival was decreased by activation of TLR2 and/or autophagy. Mfa1+P. gingivalis strain did not induce significant levels of Rab5, LC3-II, and LAMP1. In contrast, P. gingivalis uptake through a DC-SIGN independent manner was associated with early endosomal routing through Rab5, increased LC3-II and LAMP-1, as well as the formation of double membrane intracellular phagophores, a characteristic feature of autophagy. These results suggest that selective engagement of DC-SIGN by Mfa-1+P. gingivalis promotes evasion of antibacterial autophagy and lysosome fusion, resulting in intracellular persistence in myeloid DCs; however TLR2 activation can overcome autophagy evasion and pathogen persistence in DCs. PMID:25679217

  10. Porphyromonas gingivalis evasion of autophagy and intracellular killing by human myeloid dendritic cells involves DC-SIGN-TLR2 crosstalk.

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    Ahmed R El-Awady

    2015-02-01

    Full Text Available Signaling via pattern recognition receptors (PRRs expressed on professional antigen presenting cells, such as dendritic cells (DCs, is crucial to the fate of engulfed microbes. Among the many PRRs expressed by DCs are Toll-like receptors (TLRs and C-type lectins such as DC-SIGN. DC-SIGN is targeted by several major human pathogens for immune-evasion, although its role in intracellular routing of pathogens to autophagosomes is poorly understood. Here we examined the role of DC-SIGN and TLRs in evasion of autophagy and survival of Porphyromonas gingivalis in human monocyte-derived DCs (MoDCs. We employed a panel of P. gingivalis isogenic fimbriae deficient strains with defined defects in Mfa-1 fimbriae, a DC-SIGN ligand, and FimA fimbriae, a TLR2 agonist. Our results show that DC-SIGN dependent uptake of Mfa1+P. gingivalis strains by MoDCs resulted in lower intracellular killing and higher intracellular content of P. gingivalis. Moreover, Mfa1+P. gingivalis was mostly contained within single membrane vesicles, where it survived intracellularly. Survival was decreased by activation of TLR2 and/or autophagy. Mfa1+P. gingivalis strain did not induce significant levels of Rab5, LC3-II, and LAMP1. In contrast, P. gingivalis uptake through a DC-SIGN independent manner was associated with early endosomal routing through Rab5, increased LC3-II and LAMP-1, as well as the formation of double membrane intracellular phagophores, a characteristic feature of autophagy. These results suggest that selective engagement of DC-SIGN by Mfa-1+P. gingivalis promotes evasion of antibacterial autophagy and lysosome fusion, resulting in intracellular persistence in myeloid DCs; however TLR2 activation can overcome autophagy evasion and pathogen persistence in DCs.

  11. Influence of Skin Epithelial cells and Human Umbilical VEIN CELLS Conditioned Media on Maturation of Type 1 Dendritic Cells(DC1

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    M Ganjybakhsh

    2011-06-01

    Full Text Available Introduction: Dendritic cells have a high potential in presentation of antigens and can be generated and manipulated in invitro culture conditions. Dendritic cells(DC are therefore used in cancer immunotherapy, in prevention of graft rejection, treatment of allergy, autoimmune diseases and certain infectious diseases. Methods: Dendritic cell was generated in two stages. IN the first stage, monocyte cells were converted to immature DC affected GM-CSF and IL-4 .In the second stage, dendritic cells were maturated in the presence of supernatant skin epithelial cells(A375 and human umbilical vein endothelial cells(HUVEC and maturation factors. The ability of phagocytosis, expression phenotype, stimulation of T lymphocytes and cytokines was studied. Results: Mature Dendritic cells decreased their power of phagocytosis and increased expression of their surface markers. The ability of T cells stimulation and cytokine production(IL-12 increased . Conclusion: Mixture condition medium of epithelial cells and human skin umbilical vein endothelium cells induces maturation of monocyte-derived DCs. This condition medium improves their phenotype and their functions. The mentioned condition medium generates DC1 and Th1 in vitro.

  12. Unique appearance of proliferating antigen-presenting cells expressing DC-SIGN (CD209) in the decidua of early human pregnancy.

    NARCIS (Netherlands)

    Kammerer, U; Eggert, AO; Kapp, M; McLellan, AD; Geijtenbeek, T.B.H.; Dietl, J; Kooijk, van Y.; Kampgen, E

    2003-01-01

    Intact human pregnancy can be regarded as an immunological paradox in that the maternal immune system accepts the allogeneic embryo without general immunosuppression. Because dendritic cell (DC) subsets could be involved in peripheral tolerance, the uterine mucosa (decidua) was investigated for DC p

  13. Interaction of the capsular polysaccharide A from Bacteroides fragilis with DC-SIGN on human dendritic cells is necessary for its processing and presentation to T cells.

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    Karien eBloem

    2013-05-01

    Full Text Available The zwitterionic capsular polysaccharide A (PSA of Bacteroides fragilis is the first carbohydrate antigen described to be presented in major histocompatibility complex (MHC class II for the induction of CD4+ T cell responses. However, the identity of the receptor mediating binding and internalization of PSA in antigen presenting cells remains elusive. C-type lectins are glycan-binding receptors known for their capacity to target ligands for antigen presentation to T cells. Here, we investigated whether C-type lectins were involved in the internalization of PSA and identified dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN as the main receptor for PSA on human dendritic cells. The induction of PSA-specific T cell proliferation appeared to be completely dependent on DC-SIGN. These data reveal a crucial role for DC-SIGN in the endocytosis and routing of PSA in human dendritic cells for the efficient stimulation of PSA-specific CD4+ T cells.

  14. Human DC-SIGN binds specific human milk glycans.

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    Noll, Alexander J; Yu, Ying; Lasanajak, Yi; Duska-McEwen, Geralyn; Buck, Rachael H; Smith, David F; Cummings, Richard D

    2016-05-15

    Human milk glycans (HMGs) are prebiotics, pathogen receptor decoys and regulators of host physiology and immune responses. Mechanistically, human lectins (glycan-binding proteins, hGBP) expressed by dendritic cells (DCs) are of major interest, as these cells directly contact HMGs. To explore such interactions, we screened many C-type lectins and sialic acid-binding immunoglobulin-like lectins (Siglecs) expressed by DCs for glycan binding on microarrays presenting over 200 HMGs. Unexpectedly, DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) showed robust binding to many HMGs, whereas other C-type lectins failed to bind, and Siglec-5 and Siglec-9 showed weak binding to a few glycans. By contrast, most hGBP bound to multiple glycans on other microarrays lacking HMGs. An α-linked fucose residue was characteristic of HMGs bound by DC-SIGN. Binding of DC-SIGN to the simple HMGs 2'-fucosyl-lactose (2'-FL) and 3-fucosyl-lactose (3-FL) was confirmed by flow cytometry to beads conjugated with 2'-FL or 3-FL, as well as the ability of the free glycans to inhibit DC-SIGN binding. 2'-FL had an IC50 of ∼1 mM for DC-SIGN, which is within the physiological concentration of 2'-FL in human milk. These results demonstrate that DC-SIGN among the many hGBP expressed by DCs binds to α-fucosylated HMGs, and suggest that such interactions may be important in influencing immune responses in the developing infant.

  15. Human tolerogenic DC-10: perspectives for clinical applications

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    Amodio Giada

    2012-09-01

    Full Text Available Abstract Dendritic cells (DCs are critically involved in inducing either immunity or tolerance. During the last decades efforts have been devoted to the development of ad hoc methods to manipulate DCs in vitro to enhance or stabilize their tolerogenic properties. Addition of IL-10 during monocyte-derived DC differentiation allows the induction of DC-10, a subset of human tolerogenic DCs characterized by high IL-10/IL-12 ratio and co-expression of high levels of the tolerogenic molecules HLA-G and immunoglobulin-like transcript 4. DC-10 are potent inducers of adaptive type 1 regulatory T cells, well known to promote and maintain peripheral tolerance. In this review we provide an in-depth comparison of the phenotype and mechanisms of suppression mediated by DC-10 and other known regulatory antigen-presenting cells currently under clinical development. We discuss the clinical therapeutic application of DC-10 as inducers of type 1 regulatory T cells for tailoring regulatory T-cell-based cell therapy, and the use of DC-10 as adoptive cell therapy for promoting and restoring tolerance in T-cell-mediated diseases.

  16. Rhesus macaque and chimpanzee DC-SIGN act as HIV/SIV gp120 trans-receptors, similar to human DC-SIGN.

    NARCIS (Netherlands)

    Geijtenbeek, T.B.; Koopman, G.; Duijnhoven, G.C.F. van; Vliet, S.J. van; Schijndel, J.C.H.W. van; Engering, A.J.; Heeney, J.L.; Kooyk, Y. van

    2001-01-01

    Dendritic cells (DC) have been implicated in the pathogenesis of both human and simian immunodeficiency viruses (HIV and SIV, respectively). The DC-specific HIV-1 trans-receptor DC-SIGN is thought to be essential for viral dissemination by DC. Abundant expression in lymphoid tissues also implies a f

  17. Rhesus macaque and chimpanzee DC-SIGN act as HIV/SIV gp120 trans-receptors, similar to human DC-SIGN.

    NARCIS (Netherlands)

    Geijtenbeek, T.B.; Koopman, G.; Duijnhoven, G.C.F. van; Vliet, S.J. van; Schijndel, J.C.H.W. van; Engering, A.J.; Heeney, J.L.; Kooyk, Y. van

    2001-01-01

    Dendritic cells (DC) have been implicated in the pathogenesis of both human and simian immunodeficiency viruses (HIV and SIV, respectively). The DC-specific HIV-1 trans-receptor DC-SIGN is thought to be essential for viral dissemination by DC. Abundant expression in lymphoid tissues also implies a f

  18. Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...

  19. A prominent role for DC-SIGN+ dendritic cells in initiation and dissemination of measles virus infection in non-human primates.

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    Annelies W Mesman

    Full Text Available Measles virus (MV is a highly contagious virus that is transmitted by aerosols. During systemic infection, CD150(+ T and B lymphocytes in blood and lymphoid tissues are the main cells infected by pathogenic MV. However, it is unclear which cell types are the primary targets for MV in the lungs and how the virus reaches the lymphoid tissues. In vitro studies have shown that dendritic cell (DC C-type lectin DC-SIGN captures MV, leading to infection of DCs as well as transmission to lymphocytes. However, evidence of DC-SIGN-mediated transmission in vivo has not been established. Here we identified DC-SIGN(hi DCs as first target cells in vivo and demonstrate that macaque DC-SIGN functions as an attachment receptor for MV. Notably, DC-SIGN(hi cells from macaque broncho-alveolar lavage and lymph nodes transmit MV to B lymphocytes, providing in vivo support for an important role for DCs in both initiation and dissemination of MV infection.

  20. High Efficiency Interleaved Active Clamped Dc-Dc Converter with Fuel Cell for High Voltage Applications

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    Sona P

    2014-02-01

    Full Text Available A high efficiency interleaved ZVS active clamped current fed dc-dc converter is proposed in this paper specially used for fuel cell applications. As the fuel cell output is very low we are in need of a step up dc-dc converter. Here a current fed dc-dc converter is used. Two current fed dc-dc converters are interleaved by connecting their inputs in parallel and outputs in series. With this proposed methodology input current ripples in the fuel cell stacks can be reduced and a regulated output voltage ripples can be obtained. The active clamping circuit used in this model absorbs the turn off voltage spikes hence low voltage devices with low on state resistance can be used.Voltage doubler circuits will give double the output voltage than normal with smaller transformer turns ratio and flexibility. The proposed method is simulated in MATLAB for verifying the accuracy of the proposed design.

  1. HLA-G expression levels influence the tolerogenic activity of human DC-10

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    Amodio, Giada; Comi, Michela; Tomasoni, Daniela; Gianolini, Monica Emma; Rizzo, Roberta; LeMaoult, Joël; Roncarolo, Maria-Grazia; Gregori, Silvia

    2015-01-01

    Human leukocyte antigen (HLA)-G is a non-classical HLA class I molecule with known immune-modulatory functions. Our group identified a subset of human dendritic cells, named DC-10, that induce adaptive interleukin-10-producing T regulatory type 1 (Tr1) cells via the interleukin-10-dependent HLA-G/ILT4 pathway. In this study we aimed at defining the role of HLA-G in DC-10-mediated Tr1 cell differentiation. We analyzed phenotype, functions, and genetic variations in the 3′ untranslated region of the HLA-G locus of in vitro-differentiated DC-10 from 67 healthy donors. We showed that HLA-G expression on DC-10 is donor-dependent. Functional studies demonstrated that DC-10, independently of HLA-G expression, secrete interleukin-10 and negligible levels of interleukin-12. Interestingly, DC-10 with high HLA-G promote allo-specific anergic T cells that contain a significantly higher frequency of Tr1 cells, defined as interleukin-10-producing (P=0.0121) or CD49b+LAG-3+ (P=0.0031) T cells, compared to DC-10 with low HLA-G. We found that the HLA-G expression on DC-10 is genetically imprinted, being associated with specific variations in the 3′ untranslated region of the gene, and it may be finely tuned by microRNA-mediated post-transcriptional regulation. These data highlight the important role of HLA-G in boosting DC-10 tolerogenic activity and confirm that interleukin-10 production by DC-10 is necessary but not sufficient to promote Tr1 cells at high frequency. These new insights into the role of HLA-G in DC-10-mediated induction of Tr1 cells provide additional information for clinical use in Tr1- or DC-10-based cell therapy approaches. PMID:25661445

  2. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

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    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  3. Simulation and Implementation of Interleaved Boost DC-DC Converter for Fuel Cell Application

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    Ahmad Saudi Samosir

    2011-10-01

    Full Text Available This paper deals with a boost dc-dc converter for fuel cell application. In fuel cell electric vehicles application, a high power boost dc-dc converter is adopted to adjust the output voltage, current and power of fuel cell engine to meet the vehicle requirements. One of challenge in designing a boost converter for high power application is how to handle the high current at the input side. In this paper an interleaved boost dc-dc converter is proposed for current sharing on high power application. Moreover, this converter also reduces the fuel ripple current. Performance of the interleaved boost converter is tested through simulation and experimental results. Keywords: component; Interleaved Boost Converter; Fuel Cell Electric Vehicle; high power application.  

  4. Immature Dengue Virus Is Infectious in Human Immature Dendritic Cells via Interaction with the Receptor Molecule DC-SIGN

    NARCIS (Netherlands)

    Richter, Mareike K. S.; Da Silva-Voorham, Júlia M.; Torres Pedraza, Silvia; Hoornweg, Tabitha E.; van de Pol, Denise P. I.; Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    2014-01-01

    Background: Dengue Virus (DENV) is the most common mosquito-borne viral infection worldwide. Important target cells during DENV infection are macrophages, monocytes, and immature dendritic cells (imDCs). DENV-infected cells are known to secrete a large number of partially immature and fully immature

  5. Identification of different binding sites in the dendritic cell-specific receptor DC-SIGN for intercellular adhesion molecule 3 and HIV-1.

    NARCIS (Netherlands)

    Geijtenbeek, T.B.; Duijnhoven, G.C.F. van; Vliet, S. van; Krieger, E.; Vriend, G.; Figdor, C.G.; Kooyk, Y. van

    2002-01-01

    The novel dendritic cell (DC)-specific human immunodeficiency virus type 1 (HIV-1) receptor DC-SIGN plays a key role in the dissemination of HIV-1 by DC. DC-SIGN is thought to capture HIV-1 at mucosal sites of entry, facilitating transport to lymphoid tissues, where DC-SIGN efficiently transmits HIV

  6. Identification of different binding sites in the dendritic cell-specific receptor DC-SIGN for intercellular adhesion molecule 3 and HIV-1.

    NARCIS (Netherlands)

    Geijtenbeek, T.B.; Duijnhoven, G.C.F. van; Vliet, S. van; Krieger, E.; Vriend, G.; Figdor, C.G.; Kooyk, Y. van

    2002-01-01

    The novel dendritic cell (DC)-specific human immunodeficiency virus type 1 (HIV-1) receptor DC-SIGN plays a key role in the dissemination of HIV-1 by DC. DC-SIGN is thought to capture HIV-1 at mucosal sites of entry, facilitating transport to lymphoid tissues, where DC-SIGN efficiently transmits HIV

  7. High Current Planar Magnetics for High Efficiency Bidirectional DC-DC Converters for Fuel Cell Applications

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    Efficiency is one of the main concerns during the design phase of switch mode power supply. Planar magnetics based on PCB windings have the potential to reduce the magnetic manufacturing cost however, one of their main drawbacks comes from their low filling factor and high stray capacitance....... This paper presents an analysis of different planar windings configurations focusing on dc and ac resistances in order to achieve highly efficiency in dc-dc converters. The analysis considers different copper thicknesses form 70 μm up to 1500 μm (extreme copper PCB) taking into account manufacturing...... complexity and challenges. The analysis is focused on a high current inductor for a dc-dc converter for fuel cell applications and it is based on FEM simulations. Analysis and results are verified on a 6 kW dc-dc isolated full bridge boost converter prototype based on fully planar magnetics achieving a peak...

  8. A suitable model plant for control of the set fuel cell-DC/DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)

    2008-04-15

    In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)

  9. Robust DC/DC converter control for polymer electrolyte membrane fuel cell application

    Science.gov (United States)

    Wang, Ya-Xiong; Yu, Duck-Hyun; Chen, Shi-An; Kim, Young-Bae

    2014-09-01

    This study investigates a robust controller in regulating the pulse width modulation (PWM) of a DC/DC converter for a polymer electrolyte membrane fuel cell (PEMFC) application. A significant variation in the output voltage of a PEMFC depends on the power requirement and prevents a PEMFC from directly connecting to a subsequent power bus. DC/DC converters are utilized to step-up or step-down voltage to match the subsequent power bus voltage. In this study, a full dynamic model, which includes a PEMFC and boost and buck DC/DC converters, is developed under MATLAB/Simulink environment for control. A robust PWM duty ratio control for the converters is designed using time delay control (TDC). This control enables state variables to accurately follow the dynamics of a reference model using time-delayed information of plant input and output information within a few sampling periods. To prove the superiority of the TDC performance, traditional proportional-integral control (PIC) and model predictive control (MPC) are designed and implemented, and the simulation results are compared. The efficacies of TDC for the PEMFC-fed PWM DC/DC converters are validated through experimental test results using a 100 W PEMFC as well as boost and buck DC/DC converters.

  10. Novel bidirectional DC-DC converters based on the three-state switching cell

    Science.gov (United States)

    da Silva Júnior, José Carlos; Robles Balestero, Juan Paulo; Lessa Tofoli, Fernando

    2016-05-01

    It is well known that there is an increasing demand for bidirectional DC-DC converters for applications that range from renewable energy sources to electric vehicles. Within this context, this work proposes novel DC-DC converter topologies that use the three-state switching cell (3SSC), whose well-known advantages over conventional existing structures are ability to operate at high current levels, while current sharing is maintained by a high frequency transformer; reduction of cost and dimensions of magnetics; improved distribution of losses, with consequent increase of global efficiency and reduction of cost associated to the need of semiconductors with lower current ratings. Three distinct topologies can be derived from the 3SSC: one DC-DC converter with reversible current characteristic able to operate in the first and second quadrants; one DC-DC converter with reversible voltage characteristic able to operate in the first and third quadrants and one DC-DC converter with reversible current and voltage characteristics able to operate in four quadrants. Only the topology with bidirectional current characteristic is analysed in detail in terms of the operating stages in both nonoverlapping and overlapping modes, while the design procedure of the power stage elements is obtained. In order to validate the theoretical assumptions, an experimental prototype is also implemented, so that relevant issues can be properly discussed.

  11. Efficient and ripple-mitigating dc-dc converter for residential fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yong [Danfoss Solar Inverters, Hardware, Jyllandsgade 28, 6400 Soenderborg (Denmark); Choi, Seeyoung [Digital Appliance Division, Samsung Electronics Co. Ltd., Maetan-3Dong, Suwon, Gyeonggi (Korea); Lee, Eunchul [Willings Co. Ltd., SK Ventium, 522 Dangjung-Dong, Gunpo-Si, Gyeonggi-Do (Korea)

    2009-01-15

    Proton exchange membrane fuel cell (PEMFC) systems for residential application require efficient and ripple-mitigating power conditioning system (PCS). The key point to reach it, is the design and control of the dc-dc converter. Based on the theoretical and experimental analysis of the traditional converter, this paper proposes a novel parallel-series full bridge (P-SFB) dc-dc converter, and improves its phase shifting scheme. This paper also proposes a novel controller for low frequency ripple current suppressing applied on the converter. The experimental results verify that, the dc-dc converter achieves a peak efficiency of 95.5%. Therefore PCS's maximum efficiency reaches 92.9%. And the input current ripple is reduced significantly with the new controller. (author)

  12. DC-SIGN-mediated infectious synapse formation enhances X4 HIV-1 transmission from dendritic cells to T cells.

    Science.gov (United States)

    Arrighi, Jean-François; Pion, Marjorie; Garcia, Eduardo; Escola, Jean-Michel; van Kooyk, Yvette; Geijtenbeek, Teunis B; Piguet, Vincent

    2004-11-15

    Dendritic cells (DCs) are essential for the early events of human immunodeficiency virus (HIV) infection. Model systems of HIV sexual transmission have shown that DCs expressing the DC-specific C-type lectin DC-SIGN capture and internalize HIV at mucosal surfaces and efficiently transfer HIV to CD4+ T cells in lymph nodes, where viral replication occurs. Upon DC-T cell clustering, internalized HIV accumulates on the DC side at the contact zone (infectious synapse), between DCs and T cells, whereas HIV receptors and coreceptors are enriched on the T cell side. Viral concentration at the infectious synapse may explain, at least in part, why DC transmission of HIV to T cells is so efficient.Here, we have investigated the role of DC-SIGN on primary DCs in X4 HIV-1 capture and transmission using small interfering RNA-expressing lentiviral vectors to specifically knockdown DC-SIGN. We demonstrate that DC-SIGN- DCs internalize X4 HIV-1 as well as DC-SIGN+ DCs, although binding of virions is reduced. Strikingly, DC-SIGN knockdown in DCs selectively impairs infectious synapse formation between DCs and resting CD4+ T cells, but does not prevent the formation of DC-T cells conjugates. Our results demonstrate that DC-SIGN is required downstream from viral capture for the formation of the infectious synapse between DCs and T cells. These findings provide a novel explanation for the role of DC-SIGN in the transfer and enhancement of HIV infection from DCs to T cells, a crucial step for HIV transmission and pathogenesis.

  13. Human dendritic cell DC-SIGN and TLR-2 mediate complementary immune regulatory activities in response to Lactobacillus rhamnosus JB-1.

    Science.gov (United States)

    Konieczna, Patrycja; Schiavi, Elisa; Ziegler, Mario; Groeger, David; Healy, Selena; Grant, Ray; O'Mahony, Liam

    2015-01-01

    The microbiota is required for optimal host development and ongoing immune homeostasis. Lactobacilli are common inhabitants of the mammalian large intestine and immunoregulatory effects have been described for certain, but not all, strains. The mechanisms underpinning these protective effects are beginning to be elucidated. One such protective organism is Lactobacillus rhamnosus JB-1 (Lb. rhamnosus JB-1). Lb. murinus has no such anti-inflammatory protective effects and was used as a comparator organism. Human monocyte-derived dendritic cells (MDDCs) were co-incubated with bacteria and analysed over time for bacterial adhesion and intracellular processing, costimulatory molecule expression, cytokine secretion and induction of lymphocyte polarization. Neutralising antibodies were utilized to identify the responsible MDDC receptors. Lb. rhamnosus JB-1 adhered to MDDCs, but internalization and intracellular processing was significantly delayed, compared to Lb. murinus which was rapidly internalized and processed. Lb. murinus induced CD80 and CD86 expression, accompanied by high levels of cytokine secretion, while Lb. rhamnosus JB-1 was a poor inducer of costimulatory molecule expression and cytokine secretion. Lb. rhamnosus JB-1 primed MDDCs induced Foxp3 expression in autologous lymphocytes, while Lb. murinus primed MDDCs induced Foxp3, T-bet and Ror-γt expression. DC-SIGN was required for Lb. rhamnosus JB-1 adhesion and influenced IL-12 secretion, while TLR-2 influenced IL-10 and IL-12 secretion. Here we demonstrate that the delayed kinetics of bacterial processing by MDDCs correlates with MDDC activation and stimulation of lymphocytes. Thus, inhibition or delay of intracellular processing may be a novel strategy by which certain commensals may avoid the induction of proinflammatory responses.

  14. Human dendritic cell DC-SIGN and TLR-2 mediate complementary immune regulatory activities in response to Lactobacillus rhamnosus JB-1.

    Directory of Open Access Journals (Sweden)

    Patrycja Konieczna

    Full Text Available The microbiota is required for optimal host development and ongoing immune homeostasis. Lactobacilli are common inhabitants of the mammalian large intestine and immunoregulatory effects have been described for certain, but not all, strains. The mechanisms underpinning these protective effects are beginning to be elucidated. One such protective organism is Lactobacillus rhamnosus JB-1 (Lb. rhamnosus JB-1. Lb. murinus has no such anti-inflammatory protective effects and was used as a comparator organism. Human monocyte-derived dendritic cells (MDDCs were co-incubated with bacteria and analysed over time for bacterial adhesion and intracellular processing, costimulatory molecule expression, cytokine secretion and induction of lymphocyte polarization. Neutralising antibodies were utilized to identify the responsible MDDC receptors. Lb. rhamnosus JB-1 adhered to MDDCs, but internalization and intracellular processing was significantly delayed, compared to Lb. murinus which was rapidly internalized and processed. Lb. murinus induced CD80 and CD86 expression, accompanied by high levels of cytokine secretion, while Lb. rhamnosus JB-1 was a poor inducer of costimulatory molecule expression and cytokine secretion. Lb. rhamnosus JB-1 primed MDDCs induced Foxp3 expression in autologous lymphocytes, while Lb. murinus primed MDDCs induced Foxp3, T-bet and Ror-γt expression. DC-SIGN was required for Lb. rhamnosus JB-1 adhesion and influenced IL-12 secretion, while TLR-2 influenced IL-10 and IL-12 secretion. Here we demonstrate that the delayed kinetics of bacterial processing by MDDCs correlates with MDDC activation and stimulation of lymphocytes. Thus, inhibition or delay of intracellular processing may be a novel strategy by which certain commensals may avoid the induction of proinflammatory responses.

  15. Simian virus 40 inhibits differentiation and maturation of rhesus macaque DC-SIGN+-dendritic cells

    Directory of Open Access Journals (Sweden)

    Changyong G

    2010-09-01

    Full Text Available Abstract Dendritic cells (DC are the initiators and modulators of the immune responses. Some species of pathogenic microorganisms have developed immune evasion strategies by controlling antigen presentation function of DC. Simian virus 40 (SV40 is a DNA tumor virus of rhesus monkey origin. It can induce cell transformation and tumorigenesis in many vertebrate species, but often causes no visible effects and persists as a latent infection in rhesus monkeys under natural conditions. To investigate the interaction between SV40 and rhesus monkey DC, rhesus monkey peripheral blood monocyte-derived DC were induced using recombinant human Interleukin-4 (rhIL-4 and infective SV40, the phenotype and function of DC-specific intracellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN+ DC were analyzed by flow cytometry (FCM and mixed lymphocyte reaction (MLR. Results showed that SV40 can down-regulate the expression of CD83 and CD86 on DC and impair DC-induced activation of T cell proliferation. These findings suggest that SV40 might also cause immune suppression by influencing differentiation and maturation of DC.

  16. Analysis of the Coupling Behavior of PEM Fuel Cells and DC-DC Converters

    Directory of Open Access Journals (Sweden)

    Achim Kienle

    2009-03-01

    Full Text Available The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable.

  17. Analysis of the coupling behavior of PEM fuel cells and DC-DC converters

    Energy Technology Data Exchange (ETDEWEB)

    Groetsch, M.; Mangold, M.; Kienle, A. [Max Planck Institute for Dynamics of Complex Technical Systems, Process Synthesis and Process Dynamics Group, Sandtorstrasse 1, 39106 Magdeburg (Germany); Kienle, A. [Otto-von-Guericke-Universitaet Magdeburg, Lehrstuhl fuer Automatisierungstechnik / Modellbildung, Universitaetsplatz 2, 39106 Magdeburg (Germany)

    2009-07-01

    The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable. (author)

  18. DC-SCRIPT regulates glucocorticoid receptor function and expression of its target GILZ in dendritic cells.

    Science.gov (United States)

    Hontelez, Saartje; Karthaus, Nina; Looman, Maaike W; Ansems, Marleen; Adema, Gosse J

    2013-04-01

    Dendritic cells (DCs) play a central role in the immune system; they can induce immunity or tolerance depending on diverse factors in the DC environment. Pathogens, but also tissue damage, hormones, and vitamins, affect DC activation and maturation. In particular, glucocorticoids (GCs) are known for their immunosuppressive effect on DCs, creating tolerogenic DCs. GCs activate the type I nuclear receptor (NR) glucocorticoid receptor (GR), followed by induced expression of the transcription factor glucocorticoid-inducible leucine zipper (GILZ). GILZ has been shown to be necessary and sufficient for GC-induced tolerogenic DC generation. Recently, we have identified the DC-specific transcript (DC-SCRIPT) as an NR coregulator, suppressing type I steroid NRs estrogen receptor and progesterone receptor. In this study, we analyzed the effect of DC-SCRIPT on GR activity. We demonstrate that DC-SCRIPT coexists with GR in protein complexes and functions as a corepressor of GR-mediated transcription. Coexpression of DC-SCRIPT and GR is shown in human monocyte-derived DCs, and DC-SCRIPT knockdown enhances GR-dependent upregulation of GILZ mRNA expression in DCs. This demonstrates that DC-SCRIPT serves an important role in regulating GR function in DCs, corepressing GR-dependent upregulation of the tolerance-inducing transcription factor GILZ. These data imply that by controlling GR function and GILZ expression DC-SCRIPT is potentially involved in the balance between tolerance and immunity.

  19. Time delay control for fuel cells with bidirectional DC/DC converter and battery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.B. [Mechanical Engineering Department, Chonnam National University, Gwangju (Korea); Kang, S.J. [Mechatronics Engineering Department, Korea Polytechnic College V, Gwangju (Korea)

    2010-08-15

    Transient behavior is a key property in the vehicular application of proton exchange membrane (PEM) fuel cells. A better control technology is constructed to increase the transient performance of PEM fuel cells. A steady-state isothermal analytical fuel cell model is constructed to analyze mass transfer and water transport in the membrane. To prevent the starvation of air in the PEM fuel cell, time delay control is used to regulate the optimum stoichiometric amount of oxygen, although dynamic fluctuations exist in the PEM fuel cell power. A bidirectional DC/DC converter connects the battery to the DC link to manage the power distribution between the fuel cell and the battery. Dynamic evolution control (DEC) allows for adequate pulse-width modulation (PWM) control of the bidirectional DC/DC converter with fast response. Matlab/Simulink/Simpower simulation is performed to validate the proposed methodology, increase the transient performance of the PEM fuel cell system and satisfy the requirement of energy management. (author)

  20. AM3 modulates dendritic cell pathogen recognition capabilities by targeting DC-SIGN.

    Science.gov (United States)

    Serrano-Gómez, Diego; Martínez-Nuñez, Rocío T; Sierra-Filardi, Elena; Izquierdo, Nuria; Colmenares, María; Pla, Jesús; Rivas, Luis; Martinez-Picado, Javier; Jimenez-Barbero, Jesús; Alonso-Lebrero, José Luis; González, Salvador; Corbí, Angel L

    2007-07-01

    AM3 (Inmunoferon) is an orally effective immunomodulator that influences the regulatory and effector functions of the immune system whose molecular mechanisms of action are mostly unknown. We hypothesized that the polysaccharide moiety of AM3 (IF-S) might affect immune responses by modulating the lectin-dependent pathogen recognition abilities of human dendritic cells. IF-S inhibited binding of viral, fungal, and parasite pathogens by human monocyte-derived dendritic cells in a dose-dependent manner. IF-S specifically impaired the pathogen recognition capabilities of DC-SIGN, as it reduced the attachment of Candida, Aspergillus, and Leishmania to DC-SIGN transfectants. IF-S also inhibited the interaction of DC-SIGN with both its cellular counterreceptor (intercellular adhesion molecule 3) and the human immunodeficiency virus (HIV) type 1 gp120 protein and blocked the DC-SIGN-dependent capture of HIV virions and the HIV trans-infection capability of DC-SIGN transfectants. IF-S promoted DC-SIGN internalization in DCs without affecting mannose receptor expression, and (1)D saturation transfer difference nuclear magnetic resonance demonstrated that IF-S directly interacts with DC-SIGN on the cell surface. Therefore, the polysaccharide moiety of AM3 directly influences pathogen recognition by dendritic cells by interacting with DC-SIGN. Our results indicate that DC-SIGN is the target for an immunomodulator and imply that the adjuvant and immunomodulatory actions of AM3 are mediated, at least in part, by alteration of the DC-SIGN functional activities.

  1. Lentivirus-Induced Dendritic Cells (iDC for Immune-Regenerative Therapies in Cancer and Stem Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Renata Stripecke

    2014-08-01

    Full Text Available Conventional dendritic cells (cDC are ex vivo differentiated professional antigen presenting cells capable of potently stimulating naïve T cells and with vast potential for immunotherapeutic applications. The manufacture of clinical-grade cDC is relatively complex and requires several days for completion. Clinical trials showed poor trafficking of cDC from subcutaneous injection sites to lymph nodes (LN, where DC can optimally stimulate naïve lymphocytes for long-lasting memory responses. We demonstrated in mouse and human systems that a single overnight ex vivo lentiviral (LV gene transfer into DC precursors for production of combination of cytokines and antigens was capable to induce autonomous self-differentiation of antigen-loaded DC in vitro and in vivo. These highly viable induced DC (iDC effectively migrated from the injected skin to LN, where they effectively activated de novo antigen-specific effector memory T cells. Two iDC modalities were validated in relevant animal models and are now in clinical development: Self-differentiated Myeloid-derived Antigen-presenting-cells Reactive against Tumors co-expressing GM-CSF/IL-4/TRP2 for melanoma immunotherapy in the autologous setting (SmartDCtrp2, and Self-differentiated Myeloid-derived Lentivirus-induced against human cytomegalovirus as an allogeneic matched adoptive cell after stem cell transplantation (SmyleDCpp65. The lentiviral vector design and packaging methodology has “evolved” continuously in order to simplify and optimize function and biosafety of in vitro and in vivo genetic reprogramming of iDC. Here, we address the challenges seeking for new creations of genetically programmed iDC and integrase-defective LV vaccines for immune regeneration.

  2. Dynamic Contrast-Enhanced Magnetic Resonance Imaging Rapidly Indicates Vessel Regression in Human Squamous Cell Carcinomas Grown in Nude Mice Caused by VEGF Receptor 2 Blockade with DC101

    Directory of Open Access Journals (Sweden)

    Fabian Kiessling

    2004-05-01

    Full Text Available The purpose of our study was the investigation of early changes in tumor vascularization during antiangiogenic therapy with the vascular endothelial growth factor (VEGF receptor 2 antibody (DC101 using dynamic contrast-enhanced magnetic resonance imaging (DCE MRI. Subcutaneous heterotransplants of human skin squamous cell carcinomas in nude mice were treated with DC101. Animals were examined before and repeatedly during 2 weeks of antiangiogenic treatment using Gd-DTPA-enhanced dynamic T1-weighted MRI. With a two-compartment model, dynamic data were parameterized in "amplitude" (increase of signal intensity relative to precontrast value and kep (exchange rate constant. Data obtained by MRI were validated by parallel examinations of histological sections immunostained for blood vessels (CD31. Already 2 days after the first DC101 application, a decrease of tumor vascularization was observed, which preceded a reduction of tumor volume. The difference between treated tumors and controls became prominent after 4 days, when amplitudes of treated tumors were decreased by 61% (P = .02. In line with change of microvessel density, the decrease in amplitudes was most pronounced in tumor centers. On day 7, the mean tumor volumes of treated (153 ± 843 mm3 and control animals (596 ± 384 mm3 were significantly different (P = .03. After 14 days, treated tumors showed further growth reduction (83 ± 93 mm3, whereas untreated tumors (1208±822 mm3 continued to increase (P=.02. Our data underline the efficacy of DC101 as antiangiogenic treatment in human squamous cell carcinoma xenografts in nude mice and indicate DCE MRI as a valuable tool for early detection of treatment effects before changes in tumor volume become apparent.

  3. SUBCONTRACT REPORT: DC-DC Converter for Fuel Cell and Hybrid Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Marlino, Laura D [ORNL; Zhu, Lizhi [Ballard Power Systems/Siemens VDO

    2007-07-01

    The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.

  4. A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side...... and voltage doubler circuit in secondary side. Boost type converter can limit the output ripple current of the fuel cells; hybrid full-bridge structure can change operating modes according to the different input voltage; phase-shift with duty cycle control scheme is utilized to control the bidirectional power...

  5. High voltage conversion ratio, switched C & L cells, step-down DC-DC converter

    DEFF Research Database (Denmark)

    Pelan, Ovidiu; Muntean, Nicolae; Cornea, Octavian;

    2013-01-01

    The paper presents a high voltage conversion ratio DC-DC step-down topology obtained from a classical buck converter associated with an input switched-capacitor cell and an output switched-inductor cell. Analytical descriptions, the voltage and current limits of the main components are synthesized...... in a comparative form, related to the classical buck structure, in order to emphasis the advantages of the proposed converter. Digital simulations and experimental results obtained with a built prototype are compared. From the first evaluation, the proposed converter is expected to be effectively used at input...

  6. Elevation of HLA-G-expressing DC-10 cells in patients with gastric cancer.

    Science.gov (United States)

    Xu, Dan-Ping; Shi, Wei-Wu; Zhang, Tong-Tong; Lv, Hai-Yan; Li, Jing-Bo; Lin, Aifen; Yan, Wei-Hua

    2016-09-01

    DC-10 is a distinct subset of human tolerogenic dendritic cells (DCs) which express high levels of human leukocyte antigen-G (HLA-G). DC-10 could induce adaptive type 1 regulatory T cells through the IL-10 dependent ILT4/HLA-G signaling pathway. However, the significance of DC-10 in malignancies remains unclear. In this study, the frequency and mean fluorescence intensity (MFI) of HLA-G+ DC-10 in the peripheral blood of 124 patients with gastric cancer (GC) and 130 normal controls was analyzed with flow cytometry. Plasma sHLA-G was analyzed with ELISA. Results showed both the percentages of peripheral HLA-G+ DC-10 (median: 0.13% vs 0.01%; pG on these cells (median: 310.0 vs 91.5; pG+ DC-10 in GC patients was strongly relative to the tumor grade (p=0.021). sHLA-G levels in GC patients were significantly higher than in healthy controls (median: 85.80U/ml vs 61.20U/ml; pG (p>0.05). However, the increased HLA-G+ DC-10, HLA-G MFI and plasma sHLA-G in patients with gastric cancer could be a diagnostic factor with the area under the ROC curve with 0.947 (p<0.01), 0.882 (p<0.01) and 0.700 (p<0.01) respectively. Given the immune tolerant function of DC-10 could play, the increased DC-10 might play an important role in immune suppression for patients with gastric cancer, while more studies are necessary to illustrate the clinical relevance of DC-10 in cancer patients.

  7. Technical advance: Generation of human pDC equivalents from primary monocytes using Flt3-L and their functional validation under hypoxia.

    Science.gov (United States)

    Sekar, Divya; Brüne, Bernhard; Weigert, Andreas

    2010-08-01

    The division of labor between DC subsets is evolutionarily well-defined. mDC are efficient in antigen presentation, whereas pDC act as rheostats of the immune system. They activate NK cells, cause bystander activation of mDC, and interact with T cells to induce tolerance. This ambiguity positions pDC at the center of inflammatory diseases, such as cancer, arthritis, and autoimmune diseases. The ability to generate human mDC ex vivo made it possible to engineer them to suit therapy needs. Unfortunately, a similar, easily accessible system to generate human pDC is not available. We describe a method to generate human pDC equivalents ex vivo, termed mo-pDC from peripheral blood monocytes using Flt3-L. mo-pDC showed a characteristic pDC profile, such as high CD123 and BDCA4, but low CD86 and TLR4 surface expression and a low capacity to induce autologous lymphocyte proliferation and to phagocytose apoptotic debris in comparison with mDC. Interestingly, mo-pDC up-regulated the pDC lineage-determining transcription factor E2-2 as well as expression of BDCA2, which is under the transcriptional control of E2-2 but not its inhibitor ID2, during differentiation. mo-pDC produced high levels of IFN-alpha when pretreated overnight with TNF-alpha. Under hypoxia, E2-2 was down-regulated, and ID2 was induced in mo-pDC, whereas surface expression of MHCI, CD86, and BDCA2 was decreased. Furthermore, mo-pDC produced high levels of inflammatory cytokines when differentiated under hypoxia compared with normoxia. Hence, mo-pDC can be used to study differentiation and functions of human pDC under microenvironmental stimuli.

  8. Planar Integrated Magnetics (PIM) Module in Hybrid Bidirectional DC-DC Converter for Fuel Cell Application

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Zhang, Zhe; Thomsen, Ole Cornelius

    2011-01-01

    , hereby increasing the power density of converters. In this paper, a new planar integrated magnetics (PIM) module for a phase-shift plus duty cycle controlled hybrid bi-directional dc-dc converter is proposed, which assembles one boost inductor and two transformers into an E-I-E core geometry, reducing...... and theoretical analysis, a lab prototype employing the PIM module is implemented for a fuel cell application with 20~40 V input voltage and 400 V output voltage. Detailed results from the experimental comparisons demonstrate that the PIM module is fully functional and electromagnetically equivalent...

  9. Killing of naive T cells by CD95L-transfected dendritic cells (DC): in vivo study using killer DC-DC hybrids and CD4(+) T cells from DO11.10 mice.

    Science.gov (United States)

    Kusuhara, Masahiro; Matsue, Keiko; Edelbaum, Dale; Loftus, Julie; Takashima, Akira; Matsue, Hiroyuki

    2002-04-01

    Dendritic cells (DC) play the dual task of initiating cellular immunity against potentially harmful foreign antigens (Ag), while maintaining immunological tolerance to self-Ag and environmental Ag. As an approach to induce Ag-specific suppression, we and others introduced CD95 ligand (L) cDNA into DC. The resulting "killer" DC delivered apoptotic signals, instead of activation signals, to primed CD4(+) T cells in vitro and induced Ag-specific immunosuppression in vivo. To study the impact of killer DC on naive T cells, the fate of Ag-reactive T cells and the extent of their depletion after killer DC treatment, we performed in vitro and in vivo reconstitution experiments using: (a) killer DC-DC hybrids created between CD95L-transduced XS106 DC clone (A/J origin) and splenic DC from BALB/c mice, (b) CD4(+) T cells isolated from DO11.10 transgenic mice (BALB/c background), and (c) OVA(323-339) peptide as relevant Ag. Ovalbumin (OVA)-pulsed killer DC-DC hybrids inhibited DO11.10 T cell activation triggered by conventional DC, instead of inducing their activation. Rapid apoptosis of T cells was observed after co-culture with OVA-pulsed killer DC-DC hybrids, but not with non-pulsed killer DC-DC hybrids or OVA-pulsed control DC-DC hybrids. For in vivo reconstitution, (BALB/cxA/J)F1 mice received subcutaneous administration of killer DC-DC hybrids, followed by intravenous inoculation of DO11.10 T cells. Killer DC-DC hybrids migrated preferentially to draining lymph nodes albeit with relatively low efficiency (0.5-1% recovery) and they induced significant, but incomplete (30-40%) killing of DO11.10 T cells in this location. These results document the abilities of CD95L-transduced DC to trigger apoptosis of naive T cells in an Ag-specific manner, to overrule T cell activation signals delivered by conventional DC, and to reduce local frequencies of Ag-reactive T cells in vivo. Our data also uncover two major limitations (relatively low homing efficiency and incomplete

  10. Comparison of control schemes for a fuel cell hybrid tramway integrating two dc/dc converters

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, L.M.; Garcia, P.; Garcia, C.A. [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n, 11202 Algeciras (Cadiz) (Spain); Torreglosa, J.P.; Jurado, F. [Department of Electrical Engineering, EPS Linares, University of Jaen, C/Alfonso X, n 28. 23700 Linares (Jaen) (Spain)

    2010-06-15

    This paper describes a comparative study of two control schemes for the energy management system of a hybrid tramway powered by a Polymer Electrolyte Membrane (PEM) Fuel Cell (FC) and an Ni-MH battery. The hybrid system was designed for a real surface tramway of 400 kW. It is composed of a PEM FC system with a unidirectional dc/dc boost converter (FC converter) and a rechargeable Ni-MH battery with a bidirectional dc/dc converter (battery converter), both of which are coupled to a traction dc bus. The PEM FC and Ni-MH battery models were designed from commercially available components. The function of the two control architectures was to effectively distribute the power of the electrical sources. One of these control architectures was a state machine control strategy, based on eight states. The other was a cascade control strategy which was used to validate the results obtained. The simulation results for the real driving cycle of the tramway reflected the optimal performance of the control systems compared in this study. (author)

  11. The known unknowns of the human dendritic cell network

    Directory of Open Access Journals (Sweden)

    Mélanie eDurand

    2015-03-01

    Full Text Available Dendritic cells (DC initiate and orient immune responses and comprise several subsets that display distinct phenotypes and properties. Most of our knowledge of DC subsets biology is based on mouse studies. In the past few years, the alignment of the human DC network with the mouse DC network has been the focus of much attention. Although comparative phenotypic and transcriptomic analysis have shown a high level of homology between mouse and human DC subsets, significant differences in phenotype and function have also been evidenced. Here we review recent advances in our understanding of the human DC network and discuss some remaining gaps and future challenges of the human DC field.

  12. The Human Glycoprotein Salivary Agglutinin Inhibits the Interaction of DC-SIGN and Langerin with Oral Micro-Organisms.

    Science.gov (United States)

    Boks, Martine A; Gunput, Sabrina T G; Kosten, Ilona; Gibbs, Susan; van Vliet, Sandra J; Ligtenberg, Antoon J M; van Kooyk, Yvette

    2016-01-01

    Salivary agglutinin (SAG), also known as gp340 or SALSA, is a glycoprotein encoded by the Deleted in Malignant Brain Tumours 1 gene and is abundantly present in human saliva. SAG aggregates bacteria and viruses, thereby promoting their clearance from the oral cavity. The mucosa lining the oral cavity contains dendritic cells (DC) and Langerhans cells (LC), which express the C-type lectin receptors (CLR) DC-SIGN and Langerin, respectively. Both DC-SIGN and Langerin recognise mannose and fucose carbohydrate structures on pathogens and self-glycoproteins to regulate immunity and homeostasis. The purpose of this study was to investigate whether SAG interacts with these CLR and whether this interferes with the binding to oral pathogens. We show that whole parotid saliva and SAG, when coated to microplates, strongly interact with DC-SIGN and Langerin, probably via mannose and fucose structures. Also, primary human DC and LC bind parotid saliva and SAG via DC-SIGN and Langerin, respectively. Furthermore, SAG binding to DC-SIGN or Langerin prevented binding to the micro-organisms Candida albicans and Escherichia coli which express mannose and fucose-containing glycan structures. Thus, binding of saliva glycoprotein SAG to DC-SIGN and Langerin may inhibit pathogen-DC/LC interactions, and could prove to be a new immunomodulatory mechanism of SAG.

  13. [Dendritic cells (DC) induced from acute myeloid leukemia (AML) cells with cytokine cocktails].

    Science.gov (United States)

    Yan, Kuang-hua; You, Sheng-guo; Bian, Shou-geng; Ma, Guan-jie; Ge, Wei; Ma, Shuang; Liu, Shi-he; Zhao, Chun-hua

    2003-07-01

    To explore the feasibility of DC being in vitro induced from AML cells with cytokine cocktails and their biological properties. AML cells were cultured in either presence or absence of cytokine cocktails. DC were studied for morphology, and cytochemical and immunofluorescent staining. Functions of DC were examined by MLC, FITC-conjugated dextran uptake test, and LDH release assay. RT-PCR and FISH were used to analyze the specific fusion genes of culture-derived DC. Classical DC morphological changes occurred in all 15 cultured AML cells. DC-associated surface molecules such as CD(1a), CD(80), CD(86), CD(106), CD(83) and HLA-DR were upregulated (P AML cells uncultured or cultured in the absence of cytokines (P CTL assay was performed in 5 of the 15 samples. At effector/target ratio of 20:1, auto-T lymphocytes primed with the culture-derived DC exhibited no more killing activity to auto-AML cells than those stimulated by IL-2 or uncultured AML cells. Culture-derived DC presenced the native AML-specific aberrant karyotype and related fusion gene. Cytokine cocktails could in vitro induce AML cells into DC with classical morphology, immunophenotype and function. DC maturity induced by different cytokine cocktails could be variable. Culture-derived DC were originated from the native AML cells. AML cells could make the auto-T lymphocyte anergy.

  14. 外周血DC-CIK对人舌鳞癌细胞系Tca8113的抑瘤作用%The anti-tumor effect of co-cultured DC-CIK from peripheral blood to human tongue SCC cell line Tca8113in vivo

    Institute of Scientific and Technical Information of China (English)

    李思毅; 张尚权; 张陈平; 陈万涛

    2011-01-01

    目的:探讨体外致敏成熟树突状细胞(DC)与细胞因子诱导杀伤细胞(CIK)共培养细胞群对人舌鳞癌细胞系Tca8113移植瘤裸鼠的体内抑瘤效果.方法:人舌鳞癌外周血分离培养DC,体外诱导培养CIK细胞,将致敏成熟的DC与CIK体外扩增获得共培养细胞群DC-CIK细胞;于裸鼠单侧腋下接种Tca8113,将实验动物分为对照组A、实验组B和实验组C;接种后24h,A组移植瘤区注射生理盐水,B组于对侧腋下注射DC-CIK,C组同侧腋下注射DC-CIK,饲养4周;观察移植瘤的成瘤时间、成瘤率、生长曲线及组织学观察,采用SAS 6.12软件包对数据进行t检验、方差分析和x2检验.结果:A组平均成瘤时间为7.63d,B组为9.5d,C组为12d,A、C组有显著差异(P=-0.0132);注射后2周,A组成瘤率为100%,B组为87.5%,C组为62.5%,P>O.05;观察期内,从移植瘤生长曲线观察,A组瘤体增长最快,B组其次,C组最慢,A、B组无显著差异(P>0.05),A、C组差异显著(P=0.036).结论:致敏DC-CIK共培养细胞对Tca8113移植瘤裸鼠有一定的体内抑瘤效应.%PURPOSE: To evaluate the anti-tumor effect of co-cultured sensitized dendritic cell (DC) and cytokine-induced killer cell (CIK) separated from peripheral blood to human tongue SCC nude mice cancer model in vivo. METHOD: Both DC and CIK were separated and cultured in vitro from peripheral blood of oral tongue cancer patients. The sensitized DC was co-cultured with CIK. Tca8113 cells were injected into the right oxter of 24 BALB/c nude mice which were divided into control group A, experiment group B and group C. 24 hours later, group A received normal saline injection in one site with Tea 8113 transplantation, group B were injected DC-CIK in opposite side, group C were injected the same dose of DC-CIK in right oxter. The number and size of induced tumors were observed in the next 4 weeks.The data was analyzed with SAS 6.12 software package for student's t test, ANOVA and Chi-square test

  15. Cytotoxicity and genotoxicity of coronaridine from Tabernaemontana catharinensis A.DC in a human laryngeal epithelial carcinoma cell line (Hep-2

    Directory of Open Access Journals (Sweden)

    Walace Fraga Rizo

    2013-01-01

    Full Text Available Cancer has become a major public health problem worldwide and the number of deaths due to this disease is increasing almost exponentially. In the constant search for new treatments, natural products of plant origin have provided a variety of new compounds to be explored as antitumor agents. Tabernaemontana catharinensis is a medicinal plant that produces alkaloids with expressive antitumor activity, such as heyneanine, coronaridine and voacangine. The aim of present study was firstly to screen the cytotoxic activity of the indole alkaloids heyneanine, coronaridine and voacangine against HeLa (human cervix tumor, 3T3 (normal mouse embryo fibroblasts, Hep-2 (human laryngeal epithelial carcinoma and B-16 (murine skin cell lines by MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide; and secondly to analyze the apoptotic activity, cell membrane damage and genotoxicity of the compound that showed the best cytotoxic activity against the tumor cell lines tested. Coronaridine was the one that exhibited greater cytotoxic activity in the laryngeal carcinoma cell line Hep-2 (IC50 = 54.47 µg/mL than the other alkaloids tested (voacangine IC50 = 159.33 µg/mL, and heyneanine IC50 = 689.45 µg/mL. Coronaridine induced apoptosis in cell lines 3T3 and Hep-2, even at high concentrations. The evaluation of genotoxicity by comet assay showed further that coronaridine caused minimal DNA damage in the Hep-2 tumor cell line, and the LDH test showed that it did not affect the plasma membrane. These results suggest that further investigation of coronaridine as an antitumor agent has merit.

  16. Advanced DC-DC converter for power conditioning in hydrogen fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Kovacevic, G.; Tenconi, A.; Bojoi, R. [Department of Electrical Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2008-06-15

    The fuel cell (FC) generators can produce electric energy directly from hydrogen and oxygen. The DC voltage generated by FC is generally low amplitude and it is not constant, depending on the operating conditions. Furthermore, FC systems have dynamic response that is slower than the transient responses typically requested by the load. For this reason, in many applications the FC generators must be interfaced with other energy/power sources by means of an electronic power converter. An advanced full-bridge (FB) DC-DC converter, which effectively achieves zero-voltage switching and zero-current switching (ZVS-ZCS), is proposed for power-conditioning (PC) in hydrogen FC applications. The operation and features of the converter are analyzed and verified by simulations results. The ZVS-ZCS operation is obtained by means of a simple auxiliary circuit. Introduction of the soft-switching operation in PC unit brings improvements not only from the converter efficiency point of view, but also in terms of increased converter power density. Quantitative analysis of hard and soft-switching operating of the proposed converter is also made, bringing in evidence the benefits of soft-switching operation mode. The proposed converter can be a suitable solution for PC in hydrogen FC systems, especially for the medium to high-power applications. (author)

  17. Fluorescent activated cell sorting: an effective approach to study dendritic cell subsets in human atherosclerotic plaques.

    Science.gov (United States)

    Van Brussel, Ilse; Ammi, Rachid; Rombouts, Miche; Cools, Nathalie; Vercauteren, Sven R; De Roover, Dominique; Hendriks, Jeroen M H; Lauwers, Patrick; Van Schil, Paul E; Schrijvers, Dorien M

    2015-02-01

    Different immune cell types are present within atherosclerotic plaques. Dendritic cells (DC) are of special interest, since they are considered as the 'center of the immuniverse'. Identifying inflammatory DC subtypes within plaques is important for a better understanding of the lesion pathogenesis and pinpoints their contribution to the atherosclerotic process. We have developed a flow cytometry-based method to characterize and isolate different DC subsets (i.e. CD11b(+), Clec9A(+) and CD16(+) conventional (c)DC and CD123(+) plasmacytoid (p)DC) in human atherosclerotic plaques. We revealed a predominance of pro-inflammatory CD11b(+) DC in advanced human lesions, whereas atheroprotective Clec9A(+) DC were almost absent. CD123(+) pDC and CD16(+) DC were also detectable in plaques. Remarkably, plaques from distinct anatomical locations exhibited different cellular compositions: femoral plaques contained less CD11b(+) and Clec9A(+) DC than carotid plaques. Twice as many monocytes/macrophages were observed compared to DC. Moreover, relative amounts of T cells/B cells/NK cells were 6 times as high as DC numbers. For the first time, fluorescent activated cell sorting analysis of DC subsets in human plaques indicated a predominance of CD11b(+) cDC, in comparison with other DC subsets. Isolation of the different subsets will facilitate detailed functional analysis and may have significant implications for tailoring appropriate therapy.

  18. Integrated modeling and control of a PEM fuel cell power system with a PWM DC/DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Song-Yul; Ahn, Jong-Woo [Mechanical Engineering Department, Auburn University, Auburn, AL 36848 (United States); Lee, Jung-Gi [Electrical Engineering Department, Pohang University of Science and Technology, Pohang (Korea); Baek, Soo-Hyun [Electrical Engineering Department, Dong-guk University, Seoul (Korea)

    2007-02-10

    A fuel cell powered system is regarded as a high current and low voltage source. To boost the output voltage of a fuel cell, a DC/DC converter is employed. Since these two systems show different dynamics, they need to be coordinated to meet the demand of a load. This paper proposes models for the two systems with associated controls, which take into account a PEM fuel cell stack with air supply and thermal systems, and a PWM DC/DC converter. The integrated simulation facilitates optimization of the power control strategy, and analyses of interrelated effects between the electric load and the temperature of cell components. In addition, the results show that the proposed power control can coordinate the two sources with improved dynamics and efficiency at a given dynamic load. (author)

  19. An Interleaved Reduced-Component-Count Multivoltage Bus DC/DC Converter for Fuel Cell Powered Electric Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

    2008-01-01

    An interleaved reduced-component-count dc/dc converter is proposed for power management in fuel cell powered vehicles with a multivoltage electric net. The converter is based on a simplified topology and can handle more power with less ripple current, therefore reducing the capacitor requirements, making it more suited for fuel cell powered vehicles in the near future. A prototype rated at 4.3 kW was built and tested to verify the proposed topology.

  20. Analysis and Design of Bi-Directional DC-DC Converter in the Extended Run Time DC UPS System Based on Fuel Cell and Supercapacitor

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    input voltage combined with load current feedback using PI controller with anti-windup scheme to realize closed-loop control of the whole system, and verify the feasibility of the control scheme proposed by simulation. A 1kW prototype controlled by TMS320F2808 DSP is implemented and tested. Experimental......Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes...

  1. Application of Multi-port Bidirectional DC-DC Converter to Fuel Cell Vehicle Driving in JC08 Mode

    Science.gov (United States)

    Tanaka, Katsunori; Katayama, Noboru; Kogoshi, Sumio; Fukada, Takafumi; Ogawa, Makoto

    A fuel cell-EDLC hybrid power system with a multi-port bidirectional DC-DC converter has been recently proposed for extending lifetime of a fuel cell due to smoothing the output current of the fuel cell. This paper studies the performance of the hybrid power system when a fuel cell vehicle drives in the JC08 mode using a simulation model. The simulation results indicate that even if the load current fluctuates, the output current of the fuel cell could be maintained at almost constant values with an assist from the EDLC although small spikes are observed.

  2. DC electric fields direct breast cancer cell migration, induce EGFR polarization, and increase the intracellular level of calcium ions.

    Science.gov (United States)

    Wu, Dan; Ma, Xiuli; Lin, Francis

    2013-01-01

    Migration of cancer cells leads to invasion of primary tumors to distant organs (i.e., metastasis). Growing number of studies have demonstrated the migration of various cancer cell types directed by applied direct current electric fields (dcEF), i.e., electrotaxis, and suggested its potential implications in metastasis. MDA-MB-231 cell, a human metastatic breast cancer cell line, has been shown to migrate toward the anode of dcEF. Further characterizations of MDA-MB-231 cell electrotaxis and investigation of its underlying signaling mechanisms will lead to a better understanding of electrically guided cancer cell migration and metastasis. Therefore, we quantitatively characterized MDA-MB-231 cell electrotaxis and a few associated signaling events. Using a microfluidic device that can create well-controlled dcEF, we showed the anode-directing migration of MDA-MB-231 cells. In addition, surface staining of epidermal growth factor receptor (EGFR) and confocal microscopy showed the dcEF-induced anodal EGFR polarization in MDA-MB-231 cells. Furthermore, we showed an increase of intracellular calcium ions in MDA-MB-231 cells upon dcEF stimulation. Altogether, our study provided quantitative measurements of electrotactic migration of MDA-MB-231 cells, and demonstrated the electric field-mediated EGFR and calcium signaling events, suggesting their involvement in breast cancer cell electrotaxis.

  3. Quasi-Periodicity, Chaos and Coexistence in the Time Delay Controlled Two-Cell DC-DC Buck Converter

    Science.gov (United States)

    Koubaâ, Karama; Feki, Moez

    In addition to border collision bifurcation, the time delay controlled two-cell DC/DC buck converter is shown to exhibit a chaotic behavior as well. The time delay controller adds new design parameters to the system and therefore the variation of a parameter may lead to different types of bifurcation. In this work, we present a thorough analysis of different scenarios leading to bifurcation and chaos. We show that the time delay controlled two-cell DC/DC buck converter may also exhibit a Neimark-Sacker bifurcation which for some parameter set may lead to a 2D torus that may then break yielding a chaotic behavior. Besides, the saturation of the controller can also lead to the coexistence of a stable focus and a chaotic attractor. The results are presented using numerical simulation of a discrete map of the two-cell DC/DC buck converter obtained by expressing successive crossings of Poincaré section in terms of each other.

  4. Overexpression of DcR3 and Its Significance on Tumor Cell Differentiation and Proliferation in Glioma

    Directory of Open Access Journals (Sweden)

    Suning Huang

    2014-01-01

    Full Text Available Background. Overexpression of decoy receptor 3 (DcR3 have been reported in various classes of malignancies. However, its expression and clinicopathological contribution in gliomas has not been fully elucidated. Objective. To explore the expression and clinical significance of DcR3 protein in relation to tumor cell differentiation and proliferation in glioma cell lines and tissues. Methods. One hundred and twenty-five samples of glioma patients and 18 cases of normal brain tissues were recruited. The expression of DcR3 protein was detected using immunohistochemistry. Tumor differentiation was assessed by histologic characters and the status of glial fibrillary acidic protein (GFAP. Tumor cell labeling indexes (LIs of Ki-67 and PCNA were also obtained. The relationship between the DcR3 level and clinicopathological features was investigated, including tumor differentiation, LIs, and survival. Meanwhile, the expression of DcR3 protein was also measured in the supernatants of 8 glioma cell lines and glioma cells freshly prepared from 8 human glioblastoma specimens by using western blot. Results. The level of DcR3 protein in gliomas was significantly higher than that in normal brain tissues (P<0.01. DcR3 expression showed positive correlations with tumor pathological grade (r=0.621, P<0.01 and negative with GFAP expression (r=-0.489, P<0.01. Furthermore, there were positive correlations between DcR3 expression and Ki-67, PCNA LIs (r=0.529, P<0.01; r=0.556, P<0.01. The survival in the DcR3 negative group was 50 ± 1.79 months, longer than that of the DcR3 positive group (48.36 ± 2.90, however, without significance (P=0.149. Different levels of DcR3 could also be detected in the culturing supernatants of all the 8 glioma cell lines and glioma cells freshly obtained from 8 human glioblastoma specimens. Conclusions. The overexpression of DcR3 might play a crucial role in the tumorigenesis, differentiation, and proliferation of glioma.

  5. A Low-Cost Soft-Switched DC/DC Converter for Solid-Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Jason Lai

    2009-03-03

    A highly efficient DC to DC converter has been developed for low-voltage high-current solid oxide fuel cells. The newly developed 'V6' converter resembles what has been done in internal combustion engine that split into multiple cylinders to increase the output capacity without having to increase individual cell size and to smooth out the torque with interleaving operation. The development was started with topology overview to ensure that all the DC to DC converter circuits were included in the study. Efficiency models for different circuit topologies were established, and computer simulations were performed to determine the best candidate converter circuit. Through design optimization including topology selection, device selection, magnetic component design, thermal design, and digital controller design, a bench prototype rated 5-kW, with 20 to 50V input and 200/400V output was fabricated and tested. Efficiency goal of 97% was proven achievable through hardware experiment. This DC to DC converter was then modified in the later stage to converter 35 to 63 V input and 13.8 V output for automotive charging applications. The complete prototype was tested at Delphi with their solid oxide fuel cell test stand to verify the performance of the modified DC to DC converter. The output was tested up to 3-kW level, and the efficiency exceeded 97.5%. Multiple-phase interleaving operation design was proved to be reliable and ripple free at the output, which is desirable for the battery charging. Overall this is a very successful collaboration project between the SECA Core Technology Team and Industrial Team.

  6. Design and Simulation of Dc-Dc Converter for Fuel Cell Operated Vehicle with Single Reference Six Pulse Modulation

    Directory of Open Access Journals (Sweden)

    1V.Chaitanya,P.G.scholar,

    2015-10-01

    Full Text Available : Even though electrical vehicle concept is introduced in early 1800’s, it gained importance in past couple of decades due to growing conscience on environmental aspects. Different types of electrical vehicles are manufactured in the past centuries and now onboard generation is seems to be promising by fulfilling the needs of a vehicle. Fuel cells or fuel cell stack produces typically 32-68V of EMF, which has to be conditioned before it fed to motor. The conditioning involves two stages DCDC conversion and then to DC-AC conversion .DC-AC conversion is done through inverter. For DC-DC to conversion various topologies are proposed such as fly back, forward, buck-boost are proposed. This paper deals with the front end DC-DC converter and inverter switching. A hybrid modulation scheme is used to produce pulses to switch the source end full bridge rectifier and inverter at load end. In this modulation scheme high frequency pulses given to full bridge rectifier and 33% modulation scheme based pulses are produced for inverter switching.

  7. The dendritic cell-specific adhesion receptor DC-SIGN internalizes antigen for presentation to T cells.

    NARCIS (Netherlands)

    Engering, A.J.; Geijtenbeek, T.B.; Vliet, S.J. van; Wijers-Rouw, M.J.P.; Liempt, E. van; Demaurex, N.; Lanzavecchia, A.; Fransen, J.A.M.; Figdor, C.G.; Piguet, V.; Kooyk, Y. van

    2002-01-01

    Dendritic cells (DCs) capture Ags or viruses in peripheral tissue to transport them to lymphoid organs to induce cellular T cell responses. Recently, a DC-specific C-type lectin was identified, DC-specific ICAM-grabbing non-integrin (DC-SIGN), that functions as cell adhesion receptor mediating both

  8. Planar integrated magnetics design in wide input range DC-DC converter for fuel cell application

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Zhang, Zhe; Thomsen, Ole Cornelius

    2010-01-01

    , hereby increasing the power density of converters. A new planar integrated magnetics (PIM) technique for a phase-shift plus duty cycle controlled hybrid bi-directional DC/DC converter is presented and investigated in this paper. The main magnetic components including one boost inductor and two...

  9. Isolated Full Bridge Boost DC-DC Converter Designed for Bidirectional Operation of Fuel Cells/Electrolyzer Cells in Grid-Tie Applications

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    an attractive technology for energy storage grid-tie applications. In this application dc-dc converter optimization is very challenging due to the large voltage range that the converter is expected to operate. Moreover, the fuel-electrolyzer cell side of the converter is characterized by low voltage and high......Energy production from renewable energy sources is continuously varying, for this reason energy storage is becoming more and more important as the percentage of green energy increases. Newly developed fuel cells can operate in reverse mode as electrolyzer cells; therefore, they are becoming......-dc converter (IFBBC) designed for this new application focusing on losses analysis. The system topology is briefly discussed and the major concerns related to the system, cells stacks and converter operating points are analyzed. The dc-dc converter losses are modeled and presented in detail; the analysis...

  10. Hybrid electric system based on fuel cell and battery and integrating a single dc/dc converter for a tramway

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Luis M., E-mail: luis.fernandez@uca.e [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras (Cadiz) (Spain); Garcia, Pablo, E-mail: pablo.garcia@uca.e [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras (Cadiz) (Spain); Garcia, Carlos Andres, E-mail: carlosandres.garcia@uca.e [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras (Cadiz) (Spain); Jurado, Francisco, E-mail: fjurado@ujaen.e [Department of Electrical Engineering, EPS Linares, University of Jaen, C/Alfonso X, No. 28. 23700 Linares (Jaen) (Spain)

    2011-05-15

    Research highlights: {yields} Hybrid electric power system for a real surface tramway. {yields} Hybrid system based on PEM fuel cell with dc/dc converter and Ni-MH battery. {yields} New control strategy for the energy management of the tramway. {yields} Hybrid system demonstrated to meet appropriate driving cycle of the tramway. -- Abstract: This paper presents a hybrid electric power system for a real surface tramway. The hybrid system consists of two electrical energy sources integrating a single dc/dc converter to provide the power demanded by the tramway loads (four electric traction motors and auxiliary services): (1) a Polymer Electrolyte Membrane (PEM) fuel cell (FC) as the primary and (2) a rechargeable Ni-MH battery as electrical energy storage to supplement the FC over the driving cycle. According to the requirements of the real driving cycle of the tramway, it was considered a 200 kW PEM FC system with two FCs connected in parallel and a 34 Ah Ni-MH battery. The PEM FC and Ni-MH battery models were designed from commercially available components. The power conditioning system provides the appropriate power for the tramway. It is composed of: (1) a unique dc/dc boot converter which adapts the FC output voltage to the 750 V traction standard dc bus; (2) three phase inverters to drive properly each electric motors; and (3) a braking chopper to dissipate excess of regenerative braking energy. Suitable state machine control architecture is presented for the hybrid system, its objective being to provide demanded power by the driving cycle, optimizing the energy generated. Following this objective, a new state machine control strategy based on eight states decides the operating point of each component of the system and a cascade control structure allows achieving the operating points determined by the strategy. Simulation results of the real driving cycle of the tramway check the adequacy of the hybrid electric power system.

  11. The DC-HIL/syndecan-4 pathway regulates autoimmune responses through myeloid-derived suppressor cells.

    Science.gov (United States)

    Chung, Jin-Sung; Tamura, Kyoichi; Akiyoshi, Hideo; Cruz, Ponciano D; Ariizumi, Kiyoshi

    2014-03-15

    Having discovered that the dendritic cell (DC)-associated heparan sulfate proteoglycan-dependent integrin ligand (DC-HIL) receptor on APCs inhibits T cell activation by binding to syndecan-4 (SD-4) on T cells, we hypothesized that the DC-HIL/SD-4 pathway may regulate autoimmune responses. Using experimental autoimmune encephalomyelitis (EAE) as a disease model, we noted an increase in SD-4(+) T cells in lymphoid organs of wild-type (WT) mice immunized for EAE. The autoimmune disease was also more severely induced (clinically, histologically, and immunophenotypically) in mice knocked out for SD-4 compared with WT cohorts. Moreover, infusion of SD-4(-/-) naive T cells during EAE induction into Rag2(-/-) mice also led to increased severity of EAE in these animals. Similar to SD-4 on T cells, DC-HIL expression was upregulated on myeloid cells during EAE induction, with CD11b(+)Gr-1(+) myeloid-derived suppressor cells (MDSCs) as the most expanded population and most potent T cell suppressor among the myeloid cells examined. The critical role of DC-HIL was supported by DC-HIL gene deletion or anti-DC-HIL treatment, which abrogated T cell suppressor activity of MDSCs, and also by DC-HIL activation inducing MDSC expression of IFN-γ, NO, and reactive oxygen species. Akin to SD-4(-/-) mice, DC-HIL(-/-) mice manifested exacerbated EAE. Adoptive transfer of MDSCs from EAE-affected WT mice into DC-HIL(-/-) mice reduced EAE severity to the level of EAE-immunized WT mice, an outcome that was precluded by depleting DC-HIL(+) cells from the infused MDSC preparation. Our findings indicate that the DC-HIL/SD-4 pathway regulates autoimmune responses by mediating the T cell suppressor function of MDSCs.

  12. DC electric stimulation upregulates angiogenic factors in endothelial cells through activation of VEGF receptors.

    Science.gov (United States)

    Bai, Huai; Forrester, John V; Zhao, Min

    2011-07-01

    Small direct current (DC) electric fields direct some important angiogenic responses of vascular endothelial cells. Those responses indicate promising use of electric fields to modulate angiogenesis. We sought to determine the regulation of electric fields on transcription and expression of a serial of import angiogenic factors by endothelial cells themselves. Using semi-quantitative PCR and ELISA we found that electric stimulation upregulates the levels of mRNAs and proteins of a number of angiogenic proteins, most importantly VEGF165, VEGF121 and IL-8 in human endothelial cells. The up-regulation of mRNA levels might be specific, as the mRNA encoding bFGF, TGF-beta and eNOS are not affected by DC electric stimulation at 24h time-point. Inhibition of VEGF receptor (VEGFR1 or VEGFR2) signaling significantly decreased VEGF production and completely abolished IL-8 production. DC electric stimulation selectively regulates production of some growth factors and cytokines important for angiogenesis through a feed-back loop mediated by VEGF receptors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Digital Simulation of Closed Loop Zvs-Zcs Bidirectional Dc-Dc Converter for Fuel Cell and Battery Application

    Directory of Open Access Journals (Sweden)

    V. V. Subrahmanya Kumar Bhajana

    2010-08-01

    Full Text Available A closed loop ZVS-ZCS bidirectional dc-dc converter is modeled and appropriate digital simulations are provided. With the ZVS-ZCS concept, the MATLAB simulation results of application to a fuel cell and battery application have been obtained whenever the input voltage exceeds the given 24V, at that time the load voltage will change from 180V to 230V. But due to this usage the load is disturbed and there is instability in the model. Using closed loop the output voltage is stabilized.

  14. Dendritic cells engineered to secrete anti-DcR3 antibody augment cytotoxic T lymphocyte response against pancreatic cancer in vitro

    Science.gov (United States)

    Chen, Jiang; Guo, Xiao-Zhong; Li, Hong-Yu; Zhao, Jia-Jun; Xu, Wen-Da

    2017-01-01

    AIM To investigate the enhanced cytotoxic T lymphocyte responses against pancreatic cancer (PC) in vitro induced by dendritic cells (DCs) engineered to secrete anti-DcR3 monoclonal antibody (mAb). METHODS DCs, T lymphocytes and primary PC cells were obtained from PC patients. DCs were transfected with a designed humanized anti-DcR3 monoclonal antibody heavy and light chain mRNA and/or total tumor RNA (DC-tumor-anti-DcR3 RNA or DC-total tumor RNA) by using electroporation technology. The identification, concentration and function of anti-DcR3 mAb secreted by DC-tumor-anti-DcR3 RNA were determined by western blotting and enzyme-linked immunosorbent assay. After co-culturing of autologous isolated PC cells with target DCs, the effects of secreting anti-DcR3 mAb on RNA-DCs’ viability and apoptosis were assessed by MTT assay and flow cytometry. Analysis of enhanced antigen-specific immune response against PC induced by anti-DcR3 mAb secreting DCs was performed using a 51Cr releasing test. T cell responses induced by RNA-loaded DCs were analyzed by measuring cytokine levels, including IFN-γ, IL-10, IL4, TNF-α and IL-12. RESULTS The anti-DcR3 mAb secreted by DCs reacted with recombinant human DcR3 protein and generated a band with 35 kDa molecular weight. The secreting mAb was transient, peaking at 24 h and becoming undetectable after 72 h. After co-incubation with DC-tumor-anti-DcR3 RNA for designated times, the DcR3 level in the supernatant of autologous PC cells was significantly down-regulated (P < 0.05). DCs secreting anti-DcR3 mAb could improve cell viability and slow down the apoptosis of RNA-loaded DCs, compared with DC-total tumor RNA (P < 0.01). The anti-DcR3 mAb secreted by DC-tumor-anti-DcR3 RNA could enhance the induction of cytotoxic T lymphocytes (CTLs) activity toward RNA-transfected DCs, primary tumor cells, and PC cell lines, compared with CTLs stimulated by DC-total tumor RNA or control group (P < 0.05). Meanwhile, the antigen-specific CTL responses

  15. Human milk blocks DC-SIGN - pathogen interaction via MUC1

    Directory of Open Access Journals (Sweden)

    Nathalie eKoning

    2015-03-01

    Full Text Available Beneficial effects of breastfeeding are well-recognized and include both immediate neonatal protection against pathogens, as well as long term protection against allergies and autoimmune diseases. Although several proteins have been identified to have anti-viral or anti-bacterial effects like secretory IgA or lactoferrin, the mechanisms of immune modulation are not fully understood. Recent studies identified important beneficial effects of glycans in human milk, such as those expressed in oligosaccharides or on glycoproteins. Glycans are recognized by the carbohydrate receptors C-type lectins on DC and specific tissue macrophages, which exert important functions in immune modulation and immune homeostasis. A well-characterized C-type lectin is DC-SIGN, which binds terminal fucose. The present study shows that in human milk, MUC1 is the major milk glycoprotein that binds to the lectin domain of DC-SIGN and prevents pathogen interaction through the presence of Lewis x-type oligosaccharides. Surprisingly, this was specific for human milk, as formula, bovine or camel milk did not show any presence of proteins that interacted with DC-SIGN. The expression of DC-SIGN is found in young infants along the entire gastro-intestinal tract. Our data thus suggest the importance of human milk glycoproteins for blocking pathogen interaction to DC in young children. Moreover, a potential benefit of human milk later in life in shaping the infants immune system through DC-SIGN cannot be ruled out.

  16. Targeting self- and foreign antigens to dendritic cells via DC-ASGPR generates IL-10-producing suppressive CD4+ T cells.

    Science.gov (United States)

    Li, Dapeng; Romain, Gabrielle; Flamar, Anne-Laure; Duluc, Dorothée; Dullaers, Melissa; Li, Xiao-Hua; Zurawski, Sandra; Bosquet, Nathalie; Palucka, Anna Karolina; Le Grand, Roger; O'Garra, Anne; Zurawski, Gerard; Banchereau, Jacques; Oh, Sangkon

    2012-01-16

    Dendritic cells (DCs) can initiate and shape host immune responses toward either immunity or tolerance by their effects on antigen-specific CD4(+) T cells. DC-asialoglycoprotein receptor (DC-ASGPR), a lectinlike receptor, is a known scavenger receptor. Here, we report that targeting antigens to human DCs via DC-ASGPR, but not lectin-like oxidized-LDL receptor, Dectin-1, or DC-specific ICAM-3-grabbing nonintegrin favors the generation of antigen-specific suppressive CD4(+) T cells that produce interleukin 10 (IL-10). These findings apply to both self- and foreign antigens, as well as memory and naive CD4(+) T cells. The generation of such IL-10-producing CD4(+) T cells requires p38/extracellular signal-regulated kinase phosphorylation and IL-10 induction in DCs. We further demonstrate that immunization of nonhuman primates with antigens fused to anti-DC-ASGPR monoclonal antibody generates antigen-specific CD4(+) T cells that produce IL-10 in vivo. This study provides a new strategy for the establishment of antigen-specific IL-10-producing suppressive T cells in vivo by targeting whole protein antigens to DCs via DC-ASGPR.

  17. DC-HIL-expressing myelomonocytic cells are critical promoters of melanoma growth.

    Science.gov (United States)

    Chung, Jin-Sung; Tamura, Kyoichi; Cruz, Ponciano D; Ariizumi, Kiyoshi

    2014-11-01

    A major barrier to successful cancer immunotherapy is the tumor's ability to induce T-cell tolerance by exploiting host regulatory mechanisms. Having discovered the DC-HIL receptor, which inhibits T-cell responses by binding to syndecan-4 on effector T cells, we posited the DC-HIL/syndecan-4 pathway to have an important role in cancer promotion. Among DC-HIL(+) myelomonocytic cells, during growth of implanted mouse melanoma, CD11b(+)Gr1(+) cells were the most expanded population and the most potent at suppressing T-cell activation. Deletion of the DC-HIL gene or infusion of anti-DC-HIL mAb abrogated these cells' suppressor function and expansion, and markedly diminished melanoma growth and metastasis. IL-1β and IFN-γ were elevated in mice bearing melanoma, and concurrent exposure to both cytokines optimally induced DC-HIL expression by tumor-infiltrating CD11b(+)Gr1(+) cells. Ligation of DC-HIL transduced phosphorylation of its intracellular immunoreceptor tyrosine-based activation motif, which in turn induced intracellular expression of IFN-γ and inducible nitric oxide synthase (iNOS), known to mediate T-cell suppression by CD11b(+)Gr1(+) cells. Thus, DC-HIL is the critical mediator of these cells' suppressor function in melanoma-bearing mice and a potential target for improving melanoma immunotherapy.

  18. Effect of DC-CIK cells combined with oridonin on cytotoxicity against RPMI 8226 cells%冬凌草甲素联合DC-CIK细胞杀伤RPMI 8226细胞的研究

    Institute of Scientific and Technical Information of China (English)

    曲佳; 詹昱; 冯可欣; 陈玲珍; 巫进明; 杨郁青

    2014-01-01

    目的:探讨冬凌草甲素(oridonin, Ori)干预前后,DC-CIK细胞对人多发性骨髓瘤RPMI 8226细胞杀伤活性的改变。方法:分离健康人外周血单个核细胞,诱导为DC-CIK细胞,LDH释放法检测DC-CIK细胞对药物作用前后RPMI 8226细胞的杀伤活性,流式细胞术检测药物作用下肿瘤细胞表面NKG2D配体的改变情况。结果:外周血单个核细胞成功诱导生成DC-CIK细胞;在相同效靶比时,Ori能明显提高DC-CIK细胞对肿瘤细胞的杀伤活性(P<0.01);流式检测结果显示,Ori作用后,RPMI8226细胞NKG2D配体ULBP1的表达增加最为显著(9.19±1.85)(15.47±0.67),(P<0.01);相关分析提示杀伤活性与ULBP1变化呈正相关(P<0.05)。结论:Ori能提升DC-CIK细胞对人多发性骨髓瘤RPMI 8226细胞的杀伤活性,可能与上调肿瘤细胞表面NKG2D配体的表达有关。%Objective To investigate the changes in cytotoxicity of DC-CIK cells to human multiple myeloma RPMI 8226 cells before and after treatment with oridonin. Methods Normal human peripheral blood mononuclear cells were isolated and induced to obtain DC-CIK cells. Cytotoxicity of DC-CIK cells against RPMI 8226 cells which were treated by oridonin was analyzed by LDH releasing assay. The variation for expression of NKG2D ligands on RPMI 8226 cells were measured by flow cytometry. Results DC-CIK cells were successfully induced from the peripheral blood mononuclear cells. At the same effector to target ratio, oridonin obviously enhanced the cytotocixity of DC-CIK cells against RPMI 8226 cells (P<0.01). Flow cytometry showed the expression of NKG2D ligands ULBP1 of RPMI8226 cells was most significantly increased as the cells were treated by oridonin [(9.19 ± 1.85) vs. (15.47 ± 0.67), P<0.01]. Correlation analysis indicated that cytotocixity was positively correlated with changes in ULBP1. Conclusions Oridonin can improve the cytotoxicity of DC

  19. Determinants of substrate and cation transport in the human Na+/dicarboxylate cotransporter NaDC3.

    Science.gov (United States)

    Schlessinger, Avner; Sun, Nina N; Colas, Claire; Pajor, Ana M

    2014-06-13

    Metabolic intermediates, such as succinate and citrate, regulate important processes ranging from energy metabolism to fatty acid synthesis. Cytosolic concentrations of these metabolites are controlled, in part, by members of the SLC13 gene family. The molecular mechanism underlying Na(+)-coupled di- and tricarboxylate transport by this family is understood poorly. The human Na(+)/dicarboxylate cotransporter NaDC3 (SLC13A3) is found in various tissues, including the kidney, liver, and brain. In addition to citric acid cycle intermediates such as α-ketoglutarate and succinate, NaDC3 transports other compounds into cells, including N-acetyl aspartate, mercaptosuccinate, and glutathione, in keeping with its dual roles in cell nutrition and detoxification. In this study, we construct a homology structural model of NaDC3 on the basis of the structure of the Vibrio cholerae homolog vcINDY. Our computations are followed by experimental testing of the predicted NaDC3 structure and mode of interaction with various substrates. The results of this study show that the substrate and cation binding domains of NaDC3 are composed of residues in the opposing hairpin loops and unwound portions of adjacent helices. Furthermore, these results provide a possible explanation for the differential substrate specificity among dicarboxylate transporters that underpin their diverse biological roles in metabolism and detoxification. The structural model of NaDC3 provides a framework for understanding substrate selectivity and the Na(+)-coupled anion transport mechanism by the human SLC13 family and other key solute carrier transporters.

  20. Sphingosylphosphorylcholine stimulates human monocyte-derived dendritic cell chemotaxis

    Institute of Scientific and Technical Information of China (English)

    Ha-young LEE; Eun-ha SHIN; Yoe-sik BAE

    2006-01-01

    Aim: To investigate the effects of Sphingosylphosphorylcholine (SPC) on human monocyte-derived dendritic cell (DC) chemotaxis. Methods: Human DC were generated from peripheral blood monocytes by culturing them with granulocyte macrophage-colony stimulating factor and interleukin-4. The effect of SPC on the DC chemotactic migration was measured by chemotaxis assay. Intracellular signaling event involved in the SPC-induced DC chemotaxis was investigated with several inhibitors for specific kinase. The expression of the SPC receptors was examined by reverse transcription polymerase chain reaction. Results: We found that SPC induced chemotactic migration in immature DC (iDC) and mature DC (mDC). In terms of SPC-induced signaling events, mitogen activated protein kinase activation and Akt activation in iDC and mDC were stimulated. SPC-induced chemotaxis was mediated by extracellular signal-regulated protein kinase and phosphoino-sitide-3-kinase, but not by calcium in both iDC and mDC. Although mDC express ovarian cancer G protein-coupled receptor 1, but not G protein-coupled receptor 4, iDC do not express any of these receptors. To examine the involvement of sphin-gosine-1-phosphate (SIP) receptors, we checked the effect of an SIP receptor antagonist (VPC23019) on SPC-induced DC chemotaxis. VPC23019 did not affect SPC-induced DC chemotaxis. Conclusion: The results suggest that SPC may play a role in regulating DC trafficking during phagocytosis and the T cell-stimulating phase, and the unique SPC receptor, which is different from SIP receptors, is involved in SPC-induced chemotaxis.

  1. Electroporation of DC-3F cells is a dual process.

    Science.gov (United States)

    Wegner, Lars H; Frey, Wolfgang; Silve, Aude

    2015-04-01

    Treatment of biological material by pulsed electric fields is a versatile technique in biotechnology and biomedicine used, for example, in delivering DNA into cells (transfection), ablation of tumors, and food processing. Field exposure is associated with a membrane permeability increase usually ascribed to electroporation, i.e., formation of aqueous membrane pores. Knowledge of the underlying processes at the membrane level is predominantly built on theoretical considerations and molecular dynamics (MD) simulations. However, experimental data needed to monitor these processes with sufficient temporal resolution are scarce. The whole-cell patch-clamp technique was employed to investigate the effect of millisecond pulsed electric fields on DC-3F cells. Cellular membrane permeabilization was monitored by a conductance increase. For the first time, to our knowledge, it could be established experimentally that electroporation consists of two clearly separate processes: a rapid membrane poration (transient electroporation) that occurs while the membrane is depolarized or hyperpolarized to voltages beyond so-called threshold potentials (here, +201 mV and -231 mV, respectively) and is reversible within ∼100 ms after the pulse, and a long-term, or persistent, permeabilization covering the whole voltage range. The latter prevailed after the pulse for at least 40 min, the postpulse time span tested experimentally. With mildly depolarizing or hyperpolarizing pulses just above threshold potentials, the two processes could be separated, since persistent (but not transient) permeabilization required repetitive pulse exposure. Conductance increased stepwise and gradually with depolarizing and hyperpolarizing pulses, respectively. Persistent permeabilization could also be elicited by single depolarizing/hyperpolarizing pulses of very high field strength. Experimental measurements of propidium iodide uptake provided evidence of a real membrane phenomenon, rather than a mere

  2. CD56 marks human dendritic cell subsets with cytotoxic potential

    NARCIS (Netherlands)

    Roothans, D.; Smits, E.; Lion, E.; Tel, J.; Anguille, S.

    2013-01-01

    Human plasmacytoid and myeloid dendritic cells (DCs), when appropriately stimulated, can express the archetypal natural killer (NK)-cell surface marker CD56. In addition to classical DC functions, CD56+ DCs are endowed with an unconventional cytotoxic capacity.

  3. Human natural killer cells promote cross-presentation of tumor cell-derived antigens by dendritic cells.

    Science.gov (United States)

    Deauvieau, Florence; Ollion, Vincent; Doffin, Anne-Claire; Achard, Carole; Fonteneau, Jean-François; Verronese, Estelle; Durand, Isabelle; Ghittoni, Raffaella; Marvel, Jacqueline; Dezutter-Dambuyant, Colette; Walzer, Thierry; Vie, Henri; Perrot, Ivan; Goutagny, Nadège; Caux, Christophe; Valladeau-Guilemond, Jenny

    2015-03-01

    Dendritic cells (DCs) cross-present antigen (Ag) to initiate T-cell immunity against most infections and tumors. Natural killer (NK) cells are innate cytolytic lymphocytes that have emerged as key modulators of multiple DC functions. Here, we show that human NK cells promote cross-presentation of tumor cell-derived Ag by DC leading to Ag-specific CD8(+) T-cell activation. Surprisingly, cytotoxic function of NK cells was not required. Instead, we highlight a critical and nonredundant role for IFN-γ and TNF-α production by NK cells to enhance cross-presentation by DC using two different Ag models. Importantly, we observed that NK cells promote cell-associated Ag cross-presentation selectively by monocytes-derived DC (Mo-DC) and CD34-derived CD11b(neg) CD141(high) DC subsets but not by myeloid CD11b(+) DC. Moreover, we demonstrate that triggering NK cell activation by monoclonal antibodies (mAbs)-coated tumor cells leads to efficient DC cross-presentation, supporting the concept that NK cells can contribute to therapeutic mAbs efficiency by inducing downstream adaptive immunity. Taken together, our findings point toward a novel role of human NK cells bridging innate and adaptive immunity through selective induction of cell-associated Ag cross-presentation by CD141(high) DC, a process that could be exploited to better harness Ag-specific cellular immunity in immunotherapy. © 2014 UICC.

  4. Human XCR1+ dendritic cells derived in vitro from CD34+ progenitors closely resemble blood dendritic cells, including their adjuvant responsiveness, contrary to monocyte-derived dendritic cells.

    Science.gov (United States)

    Balan, Sreekumar; Ollion, Vincent; Colletti, Nicholas; Chelbi, Rabie; Montanana-Sanchis, Frédéric; Liu, Hong; Vu Manh, Thien-Phong; Sanchez, Cindy; Savoret, Juliette; Perrot, Ivan; Doffin, Anne-Claire; Fossum, Even; Bechlian, Didier; Chabannon, Christian; Bogen, Bjarne; Asselin-Paturel, Carine; Shaw, Michael; Soos, Timothy; Caux, Christophe; Valladeau-Guilemond, Jenny; Dalod, Marc

    2014-08-15

    Human monocyte-derived dendritic cell (MoDC) have been used in the clinic with moderately encouraging results. Mouse XCR1(+) DC excel at cross-presentation, can be targeted in vivo to induce protective immunity, and share characteristics with XCR1(+) human DC. Assessment of the immunoactivation potential of XCR1(+) human DC is hindered by their paucity in vivo and by their lack of a well-defined in vitro counterpart. We report in this study a protocol generating both XCR1(+) and XCR1(-) human DC in CD34(+) progenitor cultures (CD34-DC). Gene expression profiling, phenotypic characterization, and functional studies demonstrated that XCR1(-) CD34-DC are similar to canonical MoDC, whereas XCR1(+) CD34-DC resemble XCR1(+) blood DC (bDC). XCR1(+) DC were strongly activated by polyinosinic-polycytidylic acid but not LPS, and conversely for MoDC. XCR1(+) DC and MoDC expressed strikingly different patterns of molecules involved in inflammation and in cross-talk with NK or T cells. XCR1(+) CD34-DC but not MoDC efficiently cross-presented a cell-associated Ag upon stimulation by polyinosinic-polycytidylic acid or R848, likewise to what was reported for XCR1(+) bDC. Hence, it is feasible to generate high numbers of bona fide XCR1(+) human DC in vitro as a model to decipher the functions of XCR1(+) bDC and as a potential source of XCR1(+) DC for clinical use.

  5. DC within the pregnant mouse uterus influence growth and functional properties of uterine NK cells.

    Science.gov (United States)

    Karsten, Christian M; Behrends, Jochen; Wagner, Arnika K; Fuchs, Franca; Figge, Julia; Schmudde, Inken; Hellberg, Lars; Kruse, Andrea

    2009-08-01

    The vascular addressins mucosal addressin cell adhesion molecule-1, P-selectin and ICAM-1 permit alpha(4)beta(7)-integrin-expressing DC, especially those of the myeloid lineage (CD11c(+)CD11b(+) DC), to access the pregnant mouse uterus. Injection of blocking monoclonal antibodies against mucosal addressin cell adhesion molecule-1 in P-selectin(-/-) mice or experimental approaches with beta7-integrin(-/-) or ICAM-1(-/-) mice revealed that limited access or absence of CD11c(+)CD11b(+) DC at the maternal/fetal interface negatively affects the frequency, size and functional properties of uterine NK (uNK) cells. Adoptive transfer of DC obtained from WT mice into beta7-integrin(-/-) mice abrogates these effects and emphasizes the importance of DC in uNK cell differentiation. Interestingly, those implantation sites lacking CD11c(+)CD11b(+) DC are characterized by decreased IL-15 and IL-12 mRNA and/or protein levels. Chronic administration of IL-15 in these mice gives rise to uNK cell numbers and size comparable to those of WT mice, whereas additional injection of IL-12 positively affects the IFN-gamma expression of uNK cells. Real-time RT-PCR and protein arrays performed with isolated uterine DC underline the role of DC as a source of IL-15 and IL-12 in the pregnant mouse uterus.

  6. Human rhinoviruses induce IL-35-producing Treg via induction of B7-H1 (CD274) and sialoadhesin (CD169) on DC.

    Science.gov (United States)

    Seyerl, Maria; Kirchberger, Stefanie; Majdic, Otto; Seipelt, Joachim; Jindra, Christoph; Schrauf, Catharina; Stöckl, Johannes

    2010-02-01

    IL-35 is a heterodimer of EBV-induced gene 3 and of the p35 subunit of IL-12, and recently identified as an inhibitory cytokine produced by natural Treg in mice, but not in humans. Here we demonstrate that DC activated by human rhinoviruses (R-DC) induce IL-35 production and release, as well as a suppressor function in CD4(+) and CD8(+) T cells derived from human peripheral blood but not in naïve T cells from cord blood. The induction of IL-35-producing T cells by R-DC was FOXP3-independent, but blocking of B7-H1 (CD274) and sialoadhesin (CD169) on R-DC with mAb against both receptors prevented the induction of IL-35. Thus, the combinatorial signal delivered by R-DC to T cells via B7-H1 and sialoadhesin is crucial for the induction of human IL-35(+) Treg. These results demonstrate a novel pathway and its components for the induction of immune-inhibitory T cells.

  7. Optimizing the dynamics of a two-cell DC-DC buck converter by time delayed feedback control

    Science.gov (United States)

    Feki, M.; El Aroudi, A.; Robert, B. G. M.; Martínez-Salamero, L.

    2011-11-01

    A study of the dynamical behavior of a two-cell DC-DC buck converter under a digital time delayed feedback control (TDFC) is presented. Various numerical simulations and dynamical aspects of this system are illustrated in the time domain and in the parameter space. Without TDFC, the system may present many undesirable behaviors such as sub-harmonics and chaotic oscillations. TDFC is able to widen the stability range of the system. Optimum values of parameters giving rise to fast response while maintaining stable periodic behavior are given in closed form. However, it is detected that in a certain region of the parameter space, the stabilized periodic orbit may coexist with a chaotic attractor. Boundary between basins of attraction are obtained by means of numerical simulations.

  8. Uterine NK cells are critical in shaping DC immunogenic functions compatible with pregnancy progression.

    Directory of Open Access Journals (Sweden)

    Irene Tirado-González

    Full Text Available Dendritic cell (DC and natural killer (NK cell interactions are important for the regulation of innate and adaptive immunity, but their relevance during early pregnancy remains elusive. Using two different strategies to manipulate the frequency of NK cells and DC during gestation, we investigated their relative impact on the decidualization process and on angiogenic responses that characterize murine implantation. Manipulation of the frequency of NK cells, DC or both lead to a defective decidual response characterized by decreased proliferation and differentiation of stromal cells. Whereas no detrimental effects were evident upon expansion of DC, NK cell ablation in such expanded DC mice severely compromised decidual development and led to early pregnancy loss. Pregnancy failure in these mice was associated with an unbalanced production of anti-angiogenic signals and most notably, with increased expression of genes related to inflammation and immunogenic activation of DC. Thus, NK cells appear to play an important role counteracting potential anomalies raised by DC expansion and overactivity in the decidua, becoming critical for normal pregnancy progression.

  9. Uterine NK Cells Are Critical in Shaping DC Immunogenic Functions Compatible with Pregnancy Progression

    Science.gov (United States)

    Freitag, Nancy; Otto, Teresa; Thijssen, Victor L. J. L.; Moschansky, Petra; von Kwiatkowski, Petra; Klapp, Burghard F.; Winterhager, Elke; Bauersachs, Stefan; Blois, Sandra M.

    2012-01-01

    Dendritic cell (DC) and natural killer (NK) cell interactions are important for the regulation of innate and adaptive immunity, but their relevance during early pregnancy remains elusive. Using two different strategies to manipulate the frequency of NK cells and DC during gestation, we investigated their relative impact on the decidualization process and on angiogenic responses that characterize murine implantation. Manipulation of the frequency of NK cells, DC or both lead to a defective decidual response characterized by decreased proliferation and differentiation of stromal cells. Whereas no detrimental effects were evident upon expansion of DC, NK cell ablation in such expanded DC mice severely compromised decidual development and led to early pregnancy loss. Pregnancy failure in these mice was associated with an unbalanced production of anti-angiogenic signals and most notably, with increased expression of genes related to inflammation and immunogenic activation of DC. Thus, NK cells appear to play an important role counteracting potential anomalies raised by DC expansion and overactivity in the decidua, becoming critical for normal pregnancy progression. PMID:23056436

  10. Escape of HIV-1-infected dendritic cells from TRAIL-mediated NK cell cytotoxicity during NK-DC cross-talk--a pivotal role of HMGB1.

    Directory of Open Access Journals (Sweden)

    Marie-Thérèse Melki

    2010-04-01

    Full Text Available Early stages of Human Immunodeficiency Virus-1 (HIV-1 infection are associated with local recruitment and activation of important effectors of innate immunity, i.e. natural killer (NK cells and dendritic cells (DCs. Immature DCs (iDCs capture HIV-1 through specific receptors and can disseminate the infection to lymphoid tissues following their migration, which is associated to a maturation process. This process is dependent on NK cells, whose role is to keep in check the quality and the quantity of DCs undergoing maturation. If DC maturation is inappropriate, NK cells will kill them ("editing process" at sites of tissue inflammation, thus optimizing the adaptive immunity. In the context of a viral infection, NK-dependent killing of infected-DCs is a crucial event required for early elimination of infected target cells. Here, we report that NK-mediated editing of iDCs is impaired if DCs are infected with HIV-1. We first addressed the question of the mechanisms involved in iDC editing, and we show that cognate NK-iDC interaction triggers apoptosis via the TNF-related apoptosis-inducing ligand (TRAIL-Death Receptor 4 (DR4 pathway and not via the perforin pathway. Nevertheless, once infected with HIV-1, DC(HIV become resistant to NK-induced TRAIL-mediated apoptosis. This resistance occurs despite normal amounts of TRAIL released by NK cells and comparable DR4 expression on DC(HIV. The escape of DC(HIV from NK killing is due to the upregulation of two anti-apoptotic molecules, the cellular-Flice like inhibitory protein (c-FLIP and the cellular inhibitor of apoptosis 2 (c-IAP2, induced by NK-DC(HIV cognate interaction. High-mobility group box 1 (HMGB1, an alarmin and a key mediator of NK-DC cross-talk, was found to play a pivotal role in NK-dependent upregulation of c-FLIP and c-IAP2 in DC(HIV. Finally, we demonstrate that restoration of DC(HIV susceptibility to NK-induced TRAIL killing can be obtained either by silencing c-FLIP and c-IAP2 by specific

  11. Pulsed DC Electric Field-Induced Differentiation of Cortical Neural Precursor Cells.

    Directory of Open Access Journals (Sweden)

    Hui-Fang Chang

    Full Text Available We report the differentiation of neural stem and progenitor cells solely induced by direct current (DC pulses stimulation. Neural stem and progenitor cells in the adult mammalian brain are promising candidates for the development of therapeutic neuroregeneration strategies. The differentiation of neural stem and progenitor cells depends on various in vivo environmental factors, such as nerve growth factor and endogenous EF. In this study, we demonstrated that the morphologic and phenotypic changes of mouse neural stem and progenitor cells (mNPCs could be induced solely by exposure to square-wave DC pulses (magnitude 300 mV/mm at frequency of 100-Hz. The DC pulse stimulation was conducted for 48 h, and the morphologic changes of mNPCs were monitored continuously. The length of primary processes and the amount of branching significantly increased after stimulation by DC pulses for 48 h. After DC pulse treatment, the mNPCs differentiated into neurons, astrocytes, and oligodendrocytes simultaneously in stem cell maintenance medium. Our results suggest that simple DC pulse treatment could control the fate of NPCs. With further studies, DC pulses may be applied to manipulate NPC differentiation and may be used for the development of therapeutic strategies that employ NPCs to treat nervous system disorders.

  12. Pulsed DC Electric Field–Induced Differentiation of Cortical Neural Precursor Cells

    Science.gov (United States)

    Chang, Hui-Fang; Lee, Ying-Shan; Tang, Tang K.; Cheng, Ji-Yen

    2016-01-01

    We report the differentiation of neural stem and progenitor cells solely induced by direct current (DC) pulses stimulation. Neural stem and progenitor cells in the adult mammalian brain are promising candidates for the development of therapeutic neuroregeneration strategies. The differentiation of neural stem and progenitor cells depends on various in vivo environmental factors, such as nerve growth factor and endogenous EF. In this study, we demonstrated that the morphologic and phenotypic changes of mouse neural stem and progenitor cells (mNPCs) could be induced solely by exposure to square-wave DC pulses (magnitude 300 mV/mm at frequency of 100-Hz). The DC pulse stimulation was conducted for 48 h, and the morphologic changes of mNPCs were monitored continuously. The length of primary processes and the amount of branching significantly increased after stimulation by DC pulses for 48 h. After DC pulse treatment, the mNPCs differentiated into neurons, astrocytes, and oligodendrocytes simultaneously in stem cell maintenance medium. Our results suggest that simple DC pulse treatment could control the fate of NPCs. With further studies, DC pulses may be applied to manipulate NPC differentiation and may be used for the development of therapeutic strategies that employ NPCs to treat nervous system disorders. PMID:27352251

  13. Design of current source DC/DC converter and inverter for 2kW fuel cell application

    DEFF Research Database (Denmark)

    Andreiciks, A.; Steiks, I.; Krievs, O.

    2013-01-01

    of a DC/DC converter and an inverter. In this paper a detailed simulation study of such interfacing converter system comprising a double inductor push-pull step-up DC/DC converter and a cascaded H-bridge inverter has been carried out and further confirmed with experimental results. The power converter...

  14. DC3-decorated polyplexes for targeted gene delivery into dendritic cells.

    Science.gov (United States)

    Golani-Armon, Adi; Golan, Moran; Shamay, Yosi; Raviv, Lior; David, Ayelet

    2015-02-18

    Dendritic cells (DCs) are a family of specialized antigen presenting cells (APCs) that detect antigens and initiate a wide spectrum of immune responses against them. These characteristics make them promising candidates for immunotherapy manipulations. In this study we designed and synthesized DC-targeted block copolymers composed of linear polyethylenimine (PEI) conjugated to hydrophilic polyethylene glycol (PEG) installed with a DC-targeting peptide (DC3, primary sequence FYPSYHSTPQRP). Two different conjugation procedures (basic and modified) were employed to synthesize the DC3-PEG-b-PEI and the control SCRM-PEG-b-PEI (with a scrambled DC3 peptide sequence) by one-pot synthesis, in two steps. In the first, basic conjugation procedure, PEG with N-hydroxysuccinimide (NHS) ester and maleimide (MAL) groups (NHS-PEG-MAL, 3.5 kDa) was first coupled to linear PEI (25 kDa) via the NHS group to yield the intermediate MAL-PEG-b-PEI, that was then conjugated to N-terminus-cysteine harboring peptides DC3 or SCRM via the MAL double bond to yield the final DC3-PEG-b-PEI or SCRM-PEG-b-PEI copolymers, respectively. In the second, modified conjugation procedure, Fmoc-cysteine harboring DC3 or SCRM peptides were first conjugated to NHS-PEG-MAL via the MAL group followed by coupling to linear PEI via the NHS functional group. Fmoc cleavage yielded the same final product as in the basic procedure. The modified conjugation procedure was capable of yielding block copolymers richer with peptides, as determined by (1)H NMR analysis. Self-assembly of DC3-PEG-b-PEI copolymers and DNA molecules yielded nanosized polyion complexes (polyplexes), with lower surface charge and limited cytotoxicity when compared to the PEI building block. Significant transfection efficiency of the DC-targeted polyplexes by murine dendritic DC2.4 cells was observed only in DC3-PEG-b-PEI/DNA polyplexes synthesized by the modified conjugation procedure. These polyplexes, with higher peptide-load, showed greater

  15. Immunity to pathogens taught by specialized human dendritic cell subsets.

    Directory of Open Access Journals (Sweden)

    Jens A. E. Geginat

    2015-10-01

    Full Text Available Dendritic cells (DC are specialized antigen-presenting cells (APC that have a key role in immune responses, because they bridge the innate and adaptive arms of the immune system. They mature upon recognition of pathogens and up-regulate MHC molecules and co-stimulatory receptors to activate antigen-specific CD4+ and CD8+ T-cells. It is now well established that DC are not a homogeneous population, but are composed of different subsets with specialized functions in immune responses to specific pathogens. Upon viral infections, plasmacytoid DC (pDC rapidly produce large amounts of IFN-α, which has potent anti-viral functions and activates several other immune cells. However, pDC are not particularly potent APC and induce the tolerogenic cytokine IL-10 in CD4+ T-cells. In contrast, myeloid DC (mDC are very potent APC and possess the unique capacity to prime naïve T-cells and consequently to initiate a primary adaptive immune response. Different subsets of myeloid DC with specialized functions have been identified. In mice, CD8α+ mDC capture antigenic material from necrotic cells, secrete high levels of IL-12, and prime Th1 and cytotoxic T cell responses to control intracellular pathogens. Conversely, CD8α- mDC preferentially prime CD4+ T-cells and promote Th2 or Th17 differentiation. BDCA-3+ mDC2 are the human homologue of CD8α+ mDC, since they share the expression of several key molecules, the capacity to cross-present antigens to CD8+ T-cells and to produce IFN-λ. However, although several features of the DC network are conserved between humans and mice, the expression of several relevant toll-like receptors as well as the production of cytokines that regulate T-cell differentiation are different. Intriguingly, recent data suggests specific roles for human DC subsets in immune responses against individual pathogens. The biology of human DC subsets holds the promise to be exploitable in translational medicine, in particular for the

  16. Interleaved Boost-Half-Bridge Dual–Input DC-DC Converter with a PWM plus Phase-Shift Control for Fuel Cell Applications

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    This paper presents an isolated dual-input DC-DC converter with a PWM plus phase-shift control for fuel cell hybrid energy systems. The power switches are controlled by phase shifted PWM signals with a variable duty cycle, and thus the two input voltages as well as the output voltage can...

  17. Haemophilus ducreyi partially activates human myeloid dendritic cells.

    Science.gov (United States)

    Banks, Keith E; Humphreys, Tricia L; Li, Wei; Katz, Barry P; Wilkes, David S; Spinola, Stanley M

    2007-12-01

    Dendritic cells (DC) orchestrate innate and adaptive immune responses to bacteria. How Haemophilus ducreyi, which causes genital ulcers and regional lymphadenitis, interacts with DC is unknown. H. ducreyi evades uptake by polymorphonuclear leukocyte and macrophage-like cell lines by secreting LspA1 and LspA2. Many H. ducreyi strains express cytolethal distending toxin (CDT), and recombinant CDT causes apoptosis of DC in vitro. Here, we examined interactions between DC and H. ducreyi 35000HP, which produces LspA1, LspA2, and CDT. In human volunteers infected with 35000HP, the ratio of myeloid DC to plasmacytoid DC was 2.8:1 in lesions, compared to a ratio of 1:1 in peripheral blood. Using myeloid DC derived from monocytes as surrogates for lesional DC, we found that DC infected with 35000HP remained as viable as uninfected DC for up to 48 h. Gentamicin protection and confocal microscopy assays demonstrated that DC ingested and killed 35000HP, but killing was incomplete at 48 h. The expression of LspA1 and LspA2 did not inhibit the uptake of H. ducreyi, despite inactivating Src kinases. Infection of DC with live 35000HP caused less cell surface marker activation than infection with heat-killed 35000HP and lipopolysaccharide (LPS) and inhibited maturation by LPS. However, infection of DC with live bacteria caused the secretion of significantly higher levels of interleukin-6 and tumor necrosis factor alpha than infection with heat-killed bacteria and LPS. The survival of H. ducreyi in DC may provide a mechanism by which the organism traffics to lymph nodes. Partial activation of DC may abrogate the establishment of a full Th1 response and an environment that promotes phagocytosis.

  18. Plasmacytoid dendritic cells are inefficient in activation of human regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Mario Hubo

    Full Text Available BACKGROUND: Dendritic cells (DC play a key role in initiation and regulation of immune responses. Plasmacytoid DC (pDC, a small subset of DC, characterized as type-I interferon producing cells, are critically involved in anti-viral immune responses, but also mediate tolerance by induction of regulatory T cells (Treg. In this study, we compared the capacity of human pDC and conventional DC (cDC to modulate T cell activity in presence of Foxp3(+ Treg. PRINCIPAL FINDINGS: In coculture of T effector cells (Teff and Treg, activated cDC overcome Treg anergy, abrogate their suppressive function and induce Teff proliferation. In contrast, pDC do not break Treg anergy but induce Teff proliferation even in coculture with Treg. Lack of Treg-mediated suppression is independent of proinflammatory cytokines like IFN-α, IL-1, IL-6 and TNF-α. Phenotyping of pDC-stimulated Treg reveals a reduced expression of Treg activation markers GARP and CTLA-4. Additional stimulation by anti-CD3 antibodies enhances surface expression of GARP and CTLA-4 on Treg and consequently reconstitutes their suppressive function, while increased costimulation with anti-CD28 antibodies is ineffective. CONCLUSIONS/SIGNIFICANCE: Our data show that activated pDC induce Teff proliferation, but are insufficient for functional Treg activation and, therefore, allow expansion of Teff also in presence of Treg.

  19. Inhibition of DC-SIGN-mediated transmission of human immunodeficiency virus type 1 by Toll-like receptor 3 signalling in breast milk macrophages

    Science.gov (United States)

    Yagi, Yukie; Watanabe, Eri; Watari, Eiji; Shinya, Eiji; Satomi, Misao; Takeshita, Toshiyuki; Takahashi, Hidemi

    2010-01-01

    The majority of cells in early/colostrum milk are breast milk macrophages (BrMMø) expressing dendritic cell (DC)-specific intercellular adhesion molecule 3 (ICAM3) grabbing nonintegrin (DC-SIGN), and the expression level of DC-SIGN on BrMMø will determine cell-to-cell human immunodeficiency virus type 1 (HIV-1) transmissibility. Thus, one of the strategies to prevent vertical transmission of HIV-1 through breast-feeding is to find a way to suppress DC-SIGN expression on BrMMø. As for the expression of Toll-like receptors (TLRs) in BrMMø, TLR3 was always seen in BrMMø but not in peripheral blood monocytes (PBMo). Also, the expression of TLR3 was slightly enhanced in BrMMø when the cells were treated with interleukin (IL)-4. Moreover, when TLR3 was stimulated with its specific ligand, the double-stranded RNA (dsRNA) poly(I:C), DC-SIGN expression on BrMMø was reduced even in the IL-4-mediated enhanced state. Some reduction may be caused by type I interferons (IFNs), such as IFN-α/β, secreted from BrMMø. Indeed, both IFNs, particularly IFN-β, showed a strong capacity to suppress the enhancement of DC-SIGN expression on IL-4-treated BrMMø and such TLR3-mediated DC-SIGN suppression was partially abrogated by the addition of anti-IFN-α/β-receptor-specific antibodies. As expected, DC-SIGN-mediated HIV-1 transmission to CD4-positive cells by BrMMø was inhibited by either poly(I:C) stimulation or by treatment with type I IFNs. These findings suggest a possible strategy for preventing mother-to-child transmission (MTCT) of HIV-1 via breast-feeding through TLR3 signalling. PMID:20406303

  20. Human XCR1+ Dendritic Cells Derived In Vitro from CD34+ Progenitors Closely Resemble Blood Dendritic Cells, Including Their Adjuvant Responsiveness, Contrary to Monocyte-Derived Dendritic Cells

    OpenAIRE

    S. Balan; Ollion, V.; Colletti, N.; Chelbi, R.; Montanana-Sanchis, F.; LIU, H.; Vu Manh, T.-P.; Sanchez, C.; Savoret, J.; Perrot, I.; Doffin, A.-C.; Fossum, E.; Bechlian, D.; Chabannon, C.; Bogen, B

    2014-01-01

    Human monocyte-derived dendritic cell (MoDC) have been used in the clinic with moderately encouraging results. Mouse XCR1+ DC excel at cross-presentation, can be targeted in vivo to induce protective immunity, and share characteristics with XCR1+ human DC. Assessment of the immunoactivation potential of XCR1+ human DC is hindered by their paucity in vivo and by their lack of a well-defined in vitro counterpart. We report in this study a protocol generating both XCR1+ and XCR1− human DC in CD3...

  1. Microprocessor control of multiple peak power tracking DC/DC converters for use with solar cell arrays

    Science.gov (United States)

    Frederick, Martin E. (Inventor); Jermakian, Joel (Inventor)

    1991-01-01

    A method and an apparatus is provided for efficiently controlling the power output of a solar cell array string or a plurality of solar cell array strings to achieve a maximum amount of output power from the strings under varying conditions of use. Maximum power output from a solar array string is achieved through control of a pulse width modulated DC/DC buck converter which transfers power from a solar array to a load or battery bus. The input voltage from the solar array to the converter is controlled by a pulse width modulation duty cycle, which in turn is controlled by a differential signal controller. By periodically adjusting the control voltage up or down by a small amount and comparing the power on the load or bus with that generated at different voltage values a maximum power output voltage may be obtained. The system is totally modular and additional solar array strings may be added to the system simply by adding converter boards to the system and changing some constants in the controller's control routines.

  2. Generation of dendritic cells and macrophages from human induced pluripotent stem cells aiming at cell therapy.

    Science.gov (United States)

    Senju, S; Haruta, M; Matsumura, K; Matsunaga, Y; Fukushima, S; Ikeda, T; Takamatsu, K; Irie, A; Nishimura, Y

    2011-09-01

    This report describes generation of dendritic cells (DCs) and macrophages from human induced pluripotent stem (iPS) cells. iPS cell-derived DC (iPS-DC) exhibited the morphology of typical DC and function of T-cell stimulation and antigen presentation. iPS-DC loaded with cytomegalovirus (CMV) peptide induced vigorous expansion of CMV-specific autologous CD8+ T cells. Macrophages (iPS-MP) with activity of zymosan phagocytosis and C5a-induced chemotaxis were also generated from iPS cells. Genetically modified iPS-MPs were generated by the introduction of expression vectors into undifferentiated iPS cells, isolation of transfectant iPS cell clone and subsequent differentiation. By this procedure, we generated iPS-MP expressing a membrane-bound form of single chain antibody (scFv) specific to amyloid β (Aβ), the causal protein of Alzheimer's disease. The scFv-transfectant iPS-MP exhibited efficient Aβ-specific phagocytosis activity. iPS-MP expressing CD20-specific scFv engulfed and killed BALL-1 B-cell leukemia cells. Anti-BALL-1 effect of iPS-MP in vivo was demonstrated in a xeno-transplantation model using severe combined immunodeficient mice. In addition, we established a xeno-free culture protocol to generate iPS-DC and iPS-MP. Collectively, we demonstrated the possibility of application of iPS-DC and macrophages to cell therapy.

  3. A Two-stage DC-DC Converter for the Fuel Cell-Supercapacitor Hybrid System

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    A wide input range multi-stage converter is proposed with the fuel cells and supercapacitors as a hybrid system. The front-end two-phase boost converter is used to optimize the output power and to reduce the current ripple of fuel cells. The supercapacitor power module is connected by push......-pull-forward half bridge (PPFHB) converter with coupled inductors in the second stage to handle the slow transient response of the fuel cells and realize the bidirectional power flow control. Moreover, this cascaded structure simplifies the power management. The control strategy for the whole system is analyzed...

  4. Study on the immune responses against pancreatic cancer induced by mucin 4 and human telomerase reverse transcriptase mRNA co-transfected dendritic cells in vitro

    Institute of Scientific and Technical Information of China (English)

    陈江

    2014-01-01

    Objective To investigate the anti-tumor immune response induced by human pancreatic cancer mucin 4mRNA and human telomerase reverse transcriptase(hTERT)mRNA cotransfected dendritic cells(DC),and to provide the experimental evidences for the treatment of pancreatic cancer with multi-epitope loaded DC vaccine.Methods DC were isolated from peripheral DC.

  5. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x.

    NARCIS (Netherlands)

    Die, van I.M.; Vliet, van SJ; Nyame, AK; Cummings, RD; Bank, CM; Appelmelk, B.J.; Geijtenbeek, T.B.H.; Kooijk, van Y.

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies agai

  6. DC generation from peripheral blood mononuclear cells in patients with chronic myeloid leukemia: Influence of interferons on DC yield and functional properties.

    Science.gov (United States)

    Flörcken, Anne; Kopp, Joachim; Kölsch, Uwe; Meisel, Christian; Dörken, Bernd; Pezzutto, Antonio; Westermann, Jörg

    2016-05-03

    In Chronic Myeloid Leukemia (CML), standard treatment consists of modern tyrosine-kinase inhibitors (TKI). Nevertheless, there is evidence that immune responses against leukemia-associated antigens (LAA) may play an important role in disease control. Dendritic cell (DC)- based immunotherapy is able to induce T cell responses against LAA and might therefore pose an interesting therapeutic option in CML, especially in the setting of minimal residual disease (MRD). GMP production of DC for clinical vaccination remains a time- and cost- intensive procedure and standardized DC generation is warranted. We asked whether maturation-induction with IFN-γ and IFN-α has an influence on functional properties of DC derived from peripheral blood mononuclear cells (PBMC) in CML patients. Monocyte-derived DC from healthy donors and from patients with CML were analyzed after maturation-induction with our TNF-α-containing standard cytokine cocktail with or without addition of IFN-α and/or IFN-γ. Our results confirm that the addition of IFN-γ leads to enhanced IL-12 secretion in healthy donors. In contrast, in CML patients, IFN-γ was not able to increase IL-12 secretion, possibly due to a higher degree of cell adherence and lower cell yield during the cell culture. Our data suggest, that- in contrast to healthy donors-, additional interferons are not beneficial for maturation induction during large-scale DC production in patients with CML.

  7. Design of tumour-specific immunotherapies using dendritic cells – analyses of IL15-DC

    OpenAIRE

    Al-Mahdi, Rania Ali Muhsen

    2009-01-01

    Immunotherapy of malignancies aims at activating the patient’s own immune system to fight the tumour affecting the patient. Even though the use of dendritic cells (DC) has shown promising results, the DC vaccination strategy needs improvement, as only few relevant clinical responses could be documented so far. Aim: In this study, the standard protocol to generate monocyte derived DC using GM-CSF and IL-4 was compared to the use of GM-CSF and IL-15. Methods: Monocytes were isolated by plastic ...

  8. High efficiency isolated DC/DC converter inherently optimized for fuel cell applications

    DEFF Research Database (Denmark)

    Petersen, Lars Press; Jensen, Lasse Crone; Larsen, Martin Norgaard

    2013-01-01

    The isolated full-bridge boost converter has been suggested as the best choice for fuel cell applications. Comparisons have been carried out in the literature using both stress factors and experimental verified designs to determine the optimal converter. Never the less, this paper suggests a diff...

  9. Assessment of flhDC mRNA levels in Serratia liquefaciens swarm cells

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Christensen, Allan Beck; Holmstrøm, K.;

    2000-01-01

    We reported previously that artificial overexpression of the flhDC operon in liquid-grown Serratia liquefaciens resulted in the formation of filamentous, multinucleated, and hyperflagellated cells that were indistinguishable from surface-induced swarm cells (L. Eberl, G. Christiansen, S. Molin, a......, vegetative cells. This suggests that surface-induced S. liquefaciens swarm cell differentiation, although dependent on flhDC gene expression, does not occur through elevated flhDC mRNA levels.......We reported previously that artificial overexpression of the flhDC operon in liquid-grown Serratia liquefaciens resulted in the formation of filamentous, multinucleated, and hyperflagellated cells that were indistinguishable from surface-induced swarm cells (L. Eberl, G. Christiansen, S. Molin......, and M. Givskov, J. Bacteriol. 178:554-559, 1996). In the present report we show by means of reporter gene measurements, Northern analysis, and in situ reverse transcription-PCR that the amount of flhDC mRNA in surface-grown swarm cells does not exceed the maximum level found in nondifferentiated...

  10. The equivalents of human blood and spleen dendritic cell subtypes can be generated in vitro from human CD34+ stem cells in the presence of fms-like tyrosine kinase 3 ligand and thrombopoietin

    OpenAIRE

    Proietto, AI; Mittag, D; Roberts, AW; Sprigg, N; L. Wu

    2012-01-01

    Dendritic cells (DCs) are immune cells specialized to capture, process and present antigen to T cells in order to initiate an appropriate adaptive immune response. The study of mouse DC has revealed a heterogeneous population of cells that differ in their development, surface phenotype and function. The study of human blood and spleen has shown the presence of two subsets of conventional DC including the CD1b/c+ and CD141+CLEC9A+ conventional DC (cDC) and a plasmacytoid DC (pDC) that is CD304...

  11. Regulatory T cells and human myeloid dendritic cells promote tolerance via programmed death ligand-1.

    Directory of Open Access Journals (Sweden)

    Shoba Amarnath

    2010-02-01

    Full Text Available Immunotherapy using regulatory T cells (Treg has been proposed, yet cellular and molecular mechanisms of human Tregs remain incompletely characterized. Here, we demonstrate that human Tregs promote the generation of myeloid dendritic cells (DC with reduced capacity to stimulate effector T cell responses. In a model of xenogeneic graft-versus-host disease (GVHD, allogeneic human DC conditioned with Tregs suppressed human T cell activation and completely abrogated posttransplant lethality. Tregs induced programmed death ligand-1 (PD-L1 expression on Treg-conditioned DC; subsequently, Treg-conditioned DC induced PD-L1 expression in vivo on effector T cells. PD-L1 blockade reversed Treg-conditioned DC function in vitro and in vivo, thereby demonstrating that human Tregs can promote immune suppression via DC modulation through PD-L1 up-regulation. This identification of a human Treg downstream cellular effector (DC and molecular mechanism (PD-L1 will facilitate the rational design of clinical trials to modulate alloreactivity.

  12. Identification of Barramundi (Lates calcarifer) DC-SCRIPT, a Specific Molecular Marker for Dendritic Cells in Fish.

    Science.gov (United States)

    Zoccola, Emmanuelle; Delamare-Deboutteville, Jérôme; Barnes, Andrew C

    2015-01-01

    Antigen presentation is a critical step bridging innate immune recognition and specific immune memory. In mammals, the process is orchestrated by dendritic cells (DCs) in the lymphatic system, which initiate clonal proliferation of antigen-specific lymphocytes. However, fish lack a classical lymphatic system and there are currently no cellular markers for DCs in fish, thus antigen-presentation in fish is poorly understood. Recently, antigen-presenting cells similar in structure and function to mammalian DCs were identified in various fish, including rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio). The present study aimed to identify a potential molecular marker for DCs in fish and therefore targeted DC-SCRIPT, a well-conserved zinc finger protein that is preferentially expressed in all sub-types of human DCs. Putative dendritic cells were obtained in culture by maturation of spleen and pronephros-derived monocytes. DC-SCRIPT was identified in barramundi by homology using RACE PCR and genome walking. Specific expression of DC-SCRIPT was detected in barramundi cells by Stellaris mRNA FISH, in combination with MHCII expression when exposed to bacterial derived peptidoglycan, suggesting the presence of DCs in L. calcarifer. Moreover, morphological identification was achieved by light microscopy of cytospins prepared from these cultures. The cultured cells were morphologically similar to mammalian and trout DCs. Migration assays determined that these cells have the ability to move towards pathogens and pathogen associated molecular patterns, with a preference for peptidoglycans over lipopolysaccharides. The cells were also strongly phagocytic, engulfing bacteria and rapidly breaking them down. Barramundi DCs induced significant proliferation of responder populations of T-lymphocytes, supporting their role as antigen presenting cells. DC-SCRIPT expression in head kidney was higher 6 and 24 h following intraperitoneal challenge with peptidoglycan and

  13. DC疫苗对人免疫重建荷人膀胱癌NOD/SCID小鼠的抑瘤作用%Antitumor efficiency of DC vaccine in human bladder cancer-bearing NOD/ SCID mice with reconstituted human immune system

    Institute of Scientific and Technical Information of China (English)

    颜汝平; 李翀; 周海滨; 王剑松; 王伟; 赵献; 石永福

    2011-01-01

    We aimed to evaluate the antitumor efficiency of DC vaccine in human bladder cancer-bearing NOD/SCID mice with reconstituted human immune system. We isolated mononuclear cells from healthy human peripheral blood, and in vitro inducted the peripheral blood mononuclear cells (PBMCs) for obtaining dendritic cells (DCs). Then the DCs were loaded with the tumor antigen acquired from human EJ bladder cancer cell lysate for preparing DC vaccine. Human bladder cancer-bearing NOD/SCID mice with reconstituted human immune system model was established by intraperitoneal injection of human PBMCs and subcutaneous inoculation with human bladder cancer cell line EJ. Twenty NOD/SCID model mice were randomly divided into experimental group (DC-EJ group) and control group (DC group) of equal number. DC vaccines were injected intraperitoneally in DCEJ group, and DCs were injected intraperitoneally in control group. We observed the tumor growth and mice survival. Also serum IFN-γ, human T lymphocytes cells and mature DCs in transplanted tumor were detected in tumor-bearing mice. In DC-EJ group, the mouse transplanted tumor grew slowly and survival period of tumor bearing mice was prolonged as compared with the control group; the IFN-γlevels in DC-EJ group was significantly higher than that of control group (P<0.05). CD3, CD4, CD8 T lymphocytes and mature DC infiltration were all found in tumor tissues. The above results indicate that DC vaccine loaded with the bladder tumor antigen could effectively inhibit transplanted tumor to grow in NOD/SCID mice with reconstituted human immune system, which provides the experimental evidence for immunotherapy of bladder carcinoma.%目的 探讨Dc疫苗对人免疫重建荷人膀胱癌NOD/SCID小鼠的抑瘤作用.方法 从健康人外周血中分离单个核细胞(peripheral blood mononuclear cell,PBMC),经体外诱导培养获取树突状细胞(dendritic cell,DC),并负载人膀胱癌EJ细胞裂解物中提

  14. A Bidirectional, Triple-Voltage DC-DC Converter for Hybrid and Fuel Cell Vehicle Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

    2007-01-01

    Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage (14V, 42V and high voltage (HV)) nets. These will be necessary to accommodate existing 14V loads as well as efficiently handle new heavy loads at the 42V net and an electrical traction drive on the HV bus. A low-cost bi-directional dc-dc converter was proposed in (10) for connecting the three voltage nets. The converter consists of two half-bridges and a high-frequency transformer; thus minimizing the number of switching devices and their associated gate driver components. One salient feature is that the half-bridge on the 42V bus is also utilized to provide the 14V bus by operating its duty ratio around an atypical value of 1/3. This eliminates the need for an additional 14V/42V converter. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft-switching; no extra active switches or passive resonant components are required. The use of half-bridges makes the topology suitable for interleaved multi-phase configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with the atypical duty ratio on the transformer and a preferred multi-phase configuration to minimize capacitor ripple currents.

  15. Rapamycin Conditioning of Dendritic Cells Differentiated from Human ES Cells Promotes a Tolerogenic Phenotype

    Directory of Open Access Journals (Sweden)

    Kathryn M. Silk

    2012-01-01

    Full Text Available While human embryonic stem cells (hESCs may one day facilitate the treatment of degenerative diseases requiring cell replacement therapy, the success of regenerative medicine is predicated on overcoming the rejection of replacement tissues. Given the role played by dendritic cells (DCs in the establishment of immunological tolerance, we have proposed that DC, rendered tolerogenic during their differentiation from hESC, might predispose recipients to accept replacement tissues. As a first step towards this goal, we demonstrate that DC differentiated from H1 hESCs (H1-DCs are particularly responsive to the immunosuppressive agent rapamycin compared to monocyte-derived DC (moDC. While rapamycin had only modest impact on the phenotype and function of moDC, H1-DC failed to upregulate CD40 upon maturation and displayed reduced immunostimulatory capacity. Furthermore, coculture of naïve allogeneic T cells with rapamycin-treated H1-DC promoted an increased appearance of CD25hi Foxp3+ regulatory T cells, compared to moDC. Our findings suggest that conditioning of hESC-derived DC with rapamycin favours a tolerogenic phenotype.

  16. Introduction: characterization and functions of human T regulatory cells.

    Science.gov (United States)

    Romagnani, Sergio

    2005-06-01

    The field of human T regulatory (Treg) cells is a rapidly progressing, but still confused field of immunology. The effects of dendritic cell (DC) manipulation in Treg generation and the main features of human "natural" Treg cells, as well as of different populations of adaptive Treg subsets, are still partially unclear. However, it is clear that Treg cells play an important role in human diseases, such as autoimmune disorders, allergy, HIV infection, tumors and graft-versus-host disease.

  17. Dendritic Cells in the Context of Human Tumors: Biology and Experimental Tools.

    Science.gov (United States)

    Volovitz, Ilan; Melzer, Susanne; Amar, Sarah; Bocsi, József; Bloch, Merav; Efroni, Sol; Ram, Zvi; Tárnok, Attila

    2016-01-01

    Dendritic cells (DC) are the most potent and versatile antigen-presenting cells (APC) in the immune system. DC have an exceptional ability to comprehend the immune context of a captured antigen based on molecular signals identified from its vicinity. The analyzed information is then conveyed to other immune effector cells. Such capability enables DC to play a pivotal role in mediating either an immunogenic response or immune tolerance towards an acquired antigen. This review summarizes current knowledge on DC in the context of human tumors. It covers the basics of human DC biology, elaborating on the different markers, morphology and function of the different subsets of human DC. Human blood-borne DC are comprised of at least three subsets consisting of one plasmacytoid DC (pDC) and two to three myeloid DC (mDC) subsets. Some tissues have unique DC. Each subset has a different phenotype and function and may induce pro-tumoral or anti-tumoral effects. The review also discusses two methods fundamental to the research of DC on the single-cell level: multicolor flow cytometry (FCM) and image-based cytometry (IC). These methods, along with new genomics and proteomics tools, can provide high-resolution information on specific DC subsets and on immune and tumor cells with which they interact. The different layers of collected biological data may then be integrated using Immune-Cytomics modeling approaches. Such novel integrated approaches may help unravel the complex network of cellular interactions that DC carry out within tumors, and may help harness this complex immunological information into the development of more effective treatments for cancer.

  18. The Effect of dcEFs on migration behavior of A549 cells and Integrin beta1 expression

    Directory of Open Access Journals (Sweden)

    Yunjie WANG

    2008-04-01

    Full Text Available Background and objective The effect of direct-current electric fields (dcEFs on cells attracted extensive attention. Moreover the metastasis and its potential are considered to be related to dcEFs. The aim is to study the effect of dcEFs on migration behavior of A549 cells, Integrin ?1 and its signal pathways. Methods According to exposure to 5 V/cm dcEFs or not and the time of exposure, the A549 cells were divided into 4 groups. Images were taken per 5 min within 2 h to recode the migration of the cells. The data of results were analyzed statistically. Results Most of A549cells exposed to the dcEFs aligned and elongated perpendicularly to the electric field lines and migrated to the cathode continually during 2 h. On the contrary, cells unexposed to dcEFs showed slightly random movements. Immunofluorescence showed that Integrin ?1 on plasma membrane polarized to the cathode of the dcEFs. Western blot showed that Integrin beta1 downstream signal pathways p-FAK and p-ERK were overexpressed in the dcEFs. Conclusion A549 cells have a galvanotatic feature of cathodal directed migration while exposed to the dcEFs. The polarization of Integrin beta1 and the promotion of its downstream signal pathways may play an important roles in the galvanotaxis of A549 cells.

  19. Crystal Structure of the Complex of Human FasL and Its Decoy Receptor DcR3.

    Science.gov (United States)

    Liu, Weifeng; Ramagopal, Udupi; Cheng, Huiyong; Bonanno, Jeffrey B; Toro, Rafael; Bhosle, Rahul; Zhan, Chenyang; Almo, Steven C

    2016-11-01

    The apoptotic effect of FasL:Fas signaling is disrupted by DcR3, a unique secreted member of the tumor necrosis factor receptor superfamily, which also binds and neutralizes TL1A and LIGHT. DcR3 is highly elevated in patients with various tumors and contributes to mechanisms by which tumor cells to evade host immune surveillance. Here we report the crystal structure of FasL in complex with DcR3. Comparison of FasL:DcR3 structure with our earlier TL1A:DcR3 and LIGHT:DcR3 structures supports a paradigm involving the recognition of invariant main-chain and conserved side-chain functionalities, which is responsible for the recognition of multiple TNF ligands exhibited by DcR3. The FasL:DcR3 structure also provides insight into the FasL:Fas recognition surface. We demonstrate that the ability of recombinant FasL to induce Jurkat cell apoptosis is significantly enhanced by native glycosylation or by structure-inspired mutations, both of which result in reduced tendency to aggregate. All of these activities are efficiently inhibited by recombinant DcR3.

  20. Distribution and lateral mobility of DC-SIGN on immature dendritic cells--implications for pathogen uptake.

    Science.gov (United States)

    Neumann, Aaron K; Thompson, Nancy L; Jacobson, Ken

    2008-03-01

    The receptor C-type lectin DC-SIGN (CD209) is expressed by immature dendritic cells, functioning as an antigen capture receptor and cell adhesion molecule. Various microbes, including HIV-1, can exploit binding to DC-SIGN to gain entry to dendritic cells. DC-SIGN forms discrete nanoscale clusters on immature dendritic cells that are thought to be important for viral binding. We confirmed that these DC-SIGN clusters also exist both in live dendritic cells and in cell lines that ectopically express DC-SIGN. Moreover, DC-SIGN has an unusual polarized lateral distribution in the plasma membrane of dendritic cells and other cells: the receptor is preferentially localized to the leading edge of the dendritic cell lamellipod and largely excluded from the ventral plasma membrane. Colocalization of DC-SIGN clusters with endocytic activity demonstrated that surface DC-SIGN clusters are enriched near the leading edge, whereas endocytosis of these clusters occurred preferentially at lamellar sites posterior to the leading edge. Therefore, we predicted that DC-SIGN clusters move from the leading edge to zones of internalization. Two modes of lateral mobility were evident from the trajectories of DC-SIGN clusters at the leading edge, directed and non-directed mobility. Clusters with directed mobility moved in a highly linear fashion from the leading edge to rearward locations in the lamella at remarkably high velocity (1420+/-260 nm/second). Based on these data, we propose that DC-SIGN clusters move from the leading edge--where the dendritic cell is likely to encounter pathogens in tissue--to a medial lamellar site where clusters enter the cell via endocytosis. Immature dendritic cells may acquire and internalize HIV and other pathogens by this process.

  1. Interferon-α abrogates tolerance induction by human tolerogenic dendritic cells.

    Directory of Open Access Journals (Sweden)

    Nicole Bacher

    Full Text Available BACKGROUND: Administration of interferon-α (IFN-α represents an approved adjuvant therapy as reported for malignancies like melanoma and several viral infections. In malignant diseases, tolerance processes are critically involved in tumor progression. In this study, the effect of IFN-α on tolerance induction by human tolerogenic dendritic cells (DC was analyzed. We focussed on tolerogenic IL-10-modulated DC (IL-10 DC that are known to induce anergic regulatory T cells (iTregs. METHODOLOGY/PRINCIPAL FINDINGS: IFN-α promoted an enhanced maturation of IL-10 DC as demonstrated by upregulation of the differentiation marker CD83 as well as costimulatory molecules. IFN-α treatment resulted in an increased capacity of DC to stimulate T cell activation compared to control tolerogenic DC. We observed a strengthened T cell proliferation and increased IFN-γ production of CD4(+ and CD8(+ T cells stimulated by IFN-α-DC, demonstrating a restoration of the immunogenic capacity of tolerogenic DC in the presence of IFN-α. Notably, restimulation experiments revealed that IFN-α treatment of tolerogenic DC abolished the induction of T cell anergy and suppressor function of iTregs. In contrast, IFN-α neither affected the priming of iTregs nor converted iTregs into effector T cells. CONCLUSIONS/SIGNIFICANCE: IFN-α inhibits the induction of T cell tolerance by reversing the tolerogenic function of human DC.

  2. Antithymocyte Globulin Induces a Tolerogenic Phenotype in Human Dendritic Cells.

    Science.gov (United States)

    Roider, Tobias; Katzfuß, Michael; Matos, Carina; Singer, Katrin; Renner, Kathrin; Oefner, Peter J; Dettmer-Wilde, Katja; Herr, Wolfgang; Holler, Ernst; Kreutz, Marina; Peter, Katrin

    2016-12-11

    Antithymocyte globulin (ATG) is used in the prevention of graft-versus-host disease during allogeneic hematopoietic stem cell transplantation. It is generally accepted that ATG mediates its immunosuppressive effect primarily via depletion of T cells. Here, we analyzed the impact of ATG-Fresenius (now Grafalon(®)) on human monocyte-derived dendritic cells (DC). ATG induced a semi-mature phenotype in DC with significantly reduced expression of CD14, increased expression of HLA-DR, and intermediate expression of CD54, CD80, CD83, and CD86. ATG-DC showed an increase in IL-10 secretion but no IL-12 production. In line with this tolerogenic phenotype, ATG caused a significant induction of indoleamine 2,3-dioxygenase expression and a concomitant increase in levels of tryptophan metabolites in the supernatants of DC. Further, ATG-DC did not induce the proliferation of allogeneic T cells in a mixed lymphocyte reaction but actively suppressed the T cell proliferation induced by mature DC. These data suggest that besides its well-known effect on T cells, ATG modulates the phenotype of DC in a tolerogenic way, which might constitute an essential part of its immunosuppressive action in vivo.

  3. Antithymocyte Globulin Induces a Tolerogenic Phenotype in Human Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Tobias Roider

    2016-12-01

    Full Text Available Antithymocyte globulin (ATG is used in the prevention of graft-versus-host disease during allogeneic hematopoietic stem cell transplantation. It is generally accepted that ATG mediates its immunosuppressive effect primarily via depletion of T cells. Here, we analyzed the impact of ATG-Fresenius (now Grafalon® on human monocyte-derived dendritic cells (DC. ATG induced a semi-mature phenotype in DC with significantly reduced expression of CD14, increased expression of HLA-DR, and intermediate expression of CD54, CD80, CD83, and CD86. ATG-DC showed an increase in IL-10 secretion but no IL-12 production. In line with this tolerogenic phenotype, ATG caused a significant induction of indoleamine 2,3-dioxygenase expression and a concomitant increase in levels of tryptophan metabolites in the supernatants of DC. Further, ATG-DC did not induce the proliferation of allogeneic T cells in a mixed lymphocyte reaction but actively suppressed the T cell proliferation induced by mature DC. These data suggest that besides its well-known effect on T cells, ATG modulates the phenotype of DC in a tolerogenic way, which might constitute an essential part of its immunosuppressive action in vivo.

  4. Research on the biological activity and anti-tumor effect against lymphoma cells of DC-CIK cells%DC-CIK细胞的生物学活性及抗淋巴瘤细胞的作用

    Institute of Scientific and Technical Information of China (English)

    Xucang Wei; Xinhui Zhai; Wenli Zhao; Didi Yang; Xiurui Han

    2008-01-01

    Objective: To investigate the proliferation capabilities, immunophenotype changes, level of secreted cytokines and activities against lymphoma cells under the condition that cytokine-induced killer (CIK) cells co-cultured with dendritic cells (DC) in vitro. Methods: DC and CIK cells were induced from peripheral blood mononuclear cells of healthy volunteers. They were co-cultured meanwhile CIK ceils were cultured alone as controls. Increased number of cells were counted by tapan-blue staining, killing activities were detected by MTT assay, immunophenotype changes were analyzed by flow cytometry, the IL-12 and INF-γ levels of the cultured supematants were detected by ELBA kits. Results: The proliferation capabilities of DC-CIK cells were significantly higher than that of CIK cells (P < 0.05). Under the same condition, the ratio of double positive cells such as CD3+ CD8+, CD3+ CD56+ in CIK cells was significantly enhanced by co-cultured with DC cells (P < 0.05). The level of IL-12 and INF-γ secreted in supematants was increased noticeably by co-cultured DC-CIK cells on day 3 compared to CIK cells which were cultured alone (P < 0.01 and P < 0.05). Within the effector-target ratio range between 5:1 to 40:1, the activities against lymphoma cells of DC-CIK cells were much higher than that of CIK cells (P < 0.05), and this effect was showed a positive correlation with the effector-target ratio. Conclusion: The proliferation capabilities, the level of secreted cytokines and the activities against lymphoma cells of DC-CIK cells were significantly higher than those of CIK cells. The research might provides theoretical and experimental basis for clinical immunotherapy of DC-CIK cells.

  5. Mycobacterium tuberculosis impairs dendritic cell response by altering CD1b, DC-SIGN and MR profile.

    Science.gov (United States)

    Balboa, Luciana; Romero, María Mercedes; Yokobori, Noemí; Schierloh, Pablo; Geffner, Laura; Basile, Juan I; Musella, Rosa M; Abbate, Eduardo; de la Barrera, Silvia; Sasiain, María C; Alemán, Mercedes

    2010-10-01

    During a chronic infection such as tuberculosis, the pool of tissue dendritic cells (DC) must be renewed by recruitment of both circulating DC progenitors and monocytes (Mo). However, the microenvironment of the inflammatory site affects Mo differentiation. As DC are critical for initiating a Mycobacterium tuberculosis-specific T-cell response, we argue that interference of M. tuberculosis with a correct DC generation would signify a mechanism of immune evasion. In this study, we showed that early interaction of γ-irradiated M. tuberculosis with Mo subverts DC differentiation in vitro. We found that irradiated M. tuberculosis effect involves (1) the loss of a significant fraction of monocyte population and (2) an altered differentiation process of the surviving monocyte subpopulation. Moreover, in the absence of irradiated M. tuberculosis, DC consist in a major DC-specific intercellular adhesion molecule 3-grabbing non-integrin receptor (DC-SIGN(high))/CD86(low) and minor DC-SIGN(low)/CD86(high) subpopulations, whereas in the presence of bacteria, there is an enrichment of DC-SIGN(low)/CD86(high) population. Besides, this population enlarged by irradiated M. tuberculosis, which is characterized by a reduced CD1b expression, correlates with a reduced induction of specific T-lymphocyte proliferation. The loss of CD1molecules partially involves toll-like receptors (TLR-2)/p38 MAPK activation. Finally, several features of Mo, which have been differentiated into DC in the presence of irradiated M. tuberculosis, resemble the features of DC obtained from patients with active tuberculosis. In conclusion, we suggest that M. tuberculosis escapes from acquired immune response in tuberculosis may be caused by an altered differentiation into DC leading to a poor M. tuberculosis-specific T-cell response.

  6. PGE2 confers survivin-dependent apoptosis resistance in human monocyte-derived dendritic cells.

    Science.gov (United States)

    Baratelli, Felicita; Krysan, Kostyantyn; Heuzé-Vourc'h, Nathalie; Zhu, Li; Escuadro, Brian; Sharma, Sherven; Reckamp, Karen; Dohadwala, Mariam; Dubinett, Steven M

    2005-08-01

    Control of apoptosis is fundamental for dendritic cell (DC) homeostasis. Numerous factors maintain DC viability throughout their lifespan, including inhibitor of apoptosis proteins. Among them, survivin is overexpressed in many human malignancies, but its physiological function in normal cells has not been fully delineated. Prostaglandin E2 (PGE2), also overproduced in several malignancies, has shown to induce proapoptotic and antiapoptotic effects in different cell types, including immune cells. In DC, PGE2 predominantly affects maturation and modulates immune functions. Here, we show that exposure of monocyte-derived DC to PGE2 (10(-5) M) for 72 h significantly increased DC survivin mRNA and protein expression. In contrast, DC, matured with lipopolysaccharide or tumor necrosis factor alpha, did not reveal survivin induction in response to PGE2. Following exposure to apoptotic stimuli, DC treated with PGE2 exhibited an overall increased viability compared with control DC, and this effect was correlated inversely with caspase-3 activation. Moreover, PGE2-treated, survivin-deficient DC demonstrated reduced viability in response to apoptotic stimuli. Further analysis indicated that PGE2 induced DC survivin expression in an E prostanoid (EP)2/EP4 receptor and phosphatidylinositol-3 kinase-dependent manner. These findings suggest that PGE2-dependent regulation of survivin is important in modulating apoptosis resistance in human DC.

  7. The role of cDC1s in vivo: CD8 T cell priming through cross-presentation

    Science.gov (United States)

    Theisen, Derek; Murphy, Kenneth

    2017-01-01

    The cDC1 subset of classical dendritic cells is specialized for priming CD8 T cell responses through the process of cross-presentation. The molecular mechanisms of cross-presentation remain incompletely understood because of limited biochemical analysis of rare cDC1 cells, difficulty in their genetic manipulation, and reliance on in vitro systems based on monocyte- and bone-marrow-derived dendritic cells. This review will discuss cross-presentation from the perspective of studies with monocyte- or bone-marrow-derived dendritic cells while highlighting the need for future work examining cDC1 cells. We then discuss the role of cDC1s as a cellular platform to combine antigen processing for class I and class II MHC presentation to allow the integration of “help” from CD4 T cells during priming of CD8 T cell responses. PMID:28184299

  8. Genetically modified lactococcus lactis for delivery of human interleukin-10 to dendritic cells

    NARCIS (Netherlands)

    H. Braat (Henri); I.L. Huibregtse (Inge ); S.A.J. Zaat (Sebastiaan); M.L. Kapsenberg (Martien ); M.A. Sartori da Silva; M.P. Peppelenbosch (Maikel); S. van Deventer (Sander)

    2012-01-01

    textabstractInterleukin-10 (IL-10) plays an indispensable role in mucosal tolerance by programming dendritic cells (DCs) to induce suppressor Th-cells. We have tested the modulating effect of L. lactis secreting human IL-10 (L.lacti s IL-10) on DC function in vitro. Monocyte-derived DC incubated wit

  9. DC-SCRIPT is a novel regulator of the tumor suppressor gene CDKN2B and induces cell cycle arrest in ERα-positive breast cancer cells.

    Science.gov (United States)

    Ansems, Marleen; Søndergaard, Jonas Nørskov; Sieuwerts, Anieta M; Looman, Maaike W G; Smid, Marcel; de Graaf, Annemarie M A; de Weerd, Vanja; Zuidscherwoude, Malou; Foekens, John A; Martens, John W M; Adema, Gosse J

    2015-02-01

    Breast cancer is one of the most common causes of cancer-related deaths in women. The estrogen receptor (ERα) is well known for having growth promoting effects in breast cancer. Recently, we have identified DC-SCRIPT (ZNF366) as a co-suppressor of ERα and as a strong and independent prognostic marker in ESR1 (ERα gene)-positive breast cancer patients. In this study, we further investigated the molecular mechanism on how DC-SCRIPT inhibits breast cancer cell growth. DC-SCRIPT mRNA levels from 190 primary ESR1-positive breast tumors were related to global gene expression, followed by gene ontology and pathway analysis. The effect of DC-SCRIPT on breast cancer cell growth and cell cycle arrest was investigated using novel DC-SCRIPT-inducible MCF7 breast cancer cell lines. Genome-wide expression profiling of DC-SCRIPT-expressing MCF7 cells was performed to investigate the effect of DC-SCRIPT on cell cycle-related gene expression. Findings were validated by real-time PCR in a cohort of 1,132 ESR1-positive breast cancer patients. In the primary ESR1-positive breast tumors, DC-SCRIPT expression negatively correlated with several cell cycle gene ontologies and pathways. DC-SCRIPT expression strongly reduced breast cancer cell growth in vitro, breast tumor growth in vivo, and induced cell cycle arrest. In addition, in the presence of DC-SCRIPT, multiple cell cycles related genes were differentially expressed including the tumor suppressor gene CDKN2B. Moreover, in 1,132 primary ESR1-positive breast tumors, DC-SCRIPT expression also correlated with CDKN2B expression. Collectively, these data show that DC-SCRIPT acts as a novel regulator of CDKN2B and induces cell cycle arrest in ESR1-positive breast cancer cells.

  10. S-layer proteins from Lactobacillus sp. inhibit bacterial infection by blockage of DC-SIGN cell receptor.

    Science.gov (United States)

    Prado Acosta, Mariano; Ruzal, Sandra M; Cordo, Sandra M

    2016-11-01

    Many species of Lactobacillus sp. possess Surface(s) layer proteins in their envelope. Among other important characteristics S-layer from Lactobacillus acidophilus binds to the cellular receptor DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin; CD209), which is involved in adhesion and infection of several families of bacteria. In this report we investigate the activity of new S-layer proteins from the Lactobacillus family (Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus helveticus and Lactobacillus kefiri) over the infection of representative microorganisms important to human health. After the treatment of DC-SIGN expressing cells with these proteins, we were able to diminish bacterial infection by up to 79% in both gram negative and mycobacterial models. We discovered that pre-treatment of the bacteria with S-layers from Lactobacillus acidophilus and Lactobacillus brevis reduced bacteria viability but also prevent infection by the pathogenic bacteria. We also proved the importance of the glycosylation of the S-layer from Lactobacillus kefiri in the binding to the receptor and thus inhibition of infection. This novel characteristic of the S-layers proteins may contribute to the already reported pathogen exclusion activity for these Lactobacillus probiotic strains; and might be also considered as a novel enzymatic antimicrobial agents to inhibit bacterial infection and entry to host cells.

  11. MUC1 in human milk blocks transmission of human immunodeficiency virus from dendritic cells to T cells

    NARCIS (Netherlands)

    Saeland, E.; Jong, de M.A.W.P.; Nabatov, A.; Kalay, H.; Kooijk, van Y.; Geijtenbeek, T.B.H.

    2009-01-01

    Mother-to-child transmission of human immunodeficiency virus-1 (HIV-1) occurs frequently via breast-feeding. HIV-1 targets DC-SIGN+ dendritic cells (DCs) in mucosal areas that allow efficient transmission of the virus to T cells. Here, we demonstrate that the epithelial mucin MUC1, abundant in milk,

  12. MUC1 in human milk blocks transmission of human immunodeficiency virus from dendritic cells to T cells

    NARCIS (Netherlands)

    Saeland, E.; Jong, de M.A.W.P.; Nabatov, A.; Kalay, H.; Kooijk, van Y.; Geijtenbeek, T.B.H.

    2009-01-01

    Mother-to-child transmission of human immunodeficiency virus-1 (HIV-1) occurs frequently via breast-feeding. HIV-1 targets DC-SIGN+ dendritic cells (DCs) in mucosal areas that allow efficient transmission of the virus to T cells. Here, we demonstrate that the epithelial mucin MUC1, abundant in milk,

  13. [Effect of 5-aza-2'-deoxycytidine on DAPK gene expression in human HL-60 cells].

    Science.gov (United States)

    Wang, Chun-Yan; Liu, Wen-Jun

    2014-06-01

    This study was aimed to investigate the effect of methylation transferase inhibitor 5-aza-2'-deoxycytidine (5-aza-2dC) of different concentrations on the apoptosis of human acute myeloid leukemia (AML) cell line HL-60 and the expression of DAPK gene in HL-60 cells, as well as to explore the possible anti-AML mechanism of 5-aza-2dC. HL-60 cells were treated by 5-aza-2dC of different concentrations. The effect of 5-aza-2dC on the HL-60 cell morphology was observed by Wright's staining. The effect of 5-aza-2dC on HL-60 cell apoptosis and DAPK mRNA expression was detected by flow cytometry and reverse transcription-polymerize chain reaction (RT-PCR) respectively. The results showed that the 5-aza-2dC induced the apoptosis of HL-60 cells in a concentration-dependent manner; the 5-aza-2dC increased the expression levels of DAPK mRNA in HL-60 cells in a concentration-dependent manner. It is concluded that the apoptosis rate of HL-60 cells and DAPK mRNA expression level displayed a rising trend with 5-aza-2dC concentration increasing. Therefore, DAPK gene may participate in HL-60 cell apoptosis induced by 5-aza-2dC.

  14. DC-SIGN:Binding receptor for HCV?

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua Feng; Quan-Chu Wang; Qing-He Nie; Zhan-Sheng Jia; Yong-Xin Zhou

    2004-01-01

    DC-SIGN, a dendritic Cell-specific adhesion receptor and a type Ⅱ transmembrane mannose-binding C-type lectin, is very important in the function of DC, both in mediating naive T cell interactions through ICAM-3 and as a rolling receptor that mediates the DC-specific ICAM-2-dependent migration processes. It can be used by viral and bacterial pathogens including Human Immunodeficiency Virus (HIV), HCV, Ebola Virus, CMV and Mycobacterium tuberculosis to facilitate infection. Both DC-SIGN and DC-SIGNR can act either in cis,by concentrating virus on target cells, or in trans, by transmission of bound virus to a target cell expressing appropropriate entry receptors. Recent work showed that DC-SIGN are highaffinity binding receptors for HCV. Besides playing a role in entry into DC, HCV E2 interaction with DC-SIGN might also be detrimental for the interaction of DC with T cells during antigen presentation. The clinical strategies that target DCSIGN may be successful in restricting HCV dissemination and pathogenesis as well as directing the migration of DCs to manipulate appropriate immune responses in autoimmunity and tumorigenic situations.

  15. DC-DC converters for fuel cell systems. Analysis, comparision and evaluation of different concepts; Gleichspannungswandler fuer Brennstoffzellensysteme. Analyse, Vergleich und Bewertung unterschiedlicher Konzepte

    Energy Technology Data Exchange (ETDEWEB)

    Averberg, Andreas

    2009-07-01

    Fuel cells in the kW range have relatively high output currents and low output voltages, which strongly depend on the load. Furthermore, ripple currents have a negative impact on efficiency and lifetime of the cells. These characteristics have to be taken into consideration in the design process of a dc-dc converter for fuel cell applications. This work focuses on the investigation of voltage-fed, current-fed and two-stage converters, comparing them with respect to their suitability for the use in fuel cell systems. For this purpose, analytical calculations are given, completely describing the operating behaviour of each individual topology. As a consequence, it is possible to present the trend of characteristic values as e.g. rms currents in all devices and the magnetic stress in the inductive components, depending on topology and operating parameters. The impact of switching frequency, the transformer's leakage inductance and its winding ratio and the value of an optional input or output inductor is clearly and completely stated out. Furthermore, depending on the aforementioned papameters, the location of optimum efficiency can be specified for all operating conditions. The power losses can be divided into their single parts. In this way, an optimised converter design is provided. Due to the leakage inductance in combination with a high switching frequency, the transferable power is limited in the investigated one-stage converters. This can especially be noticed in low input voltage applications, as is the case in fuel cell systems. An analytical equation for the maximum power of each dc-dc converter is deduced. Base on the analytical investigations, a comparison of the different dc-dc converters is done. Assuming equal chip areas of the semiconductor devices, equal ripple currents at the input of each topology and with consideration of the overall installed size, the converter efficiencies are calculated for full load as well as for partial load. This

  16. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    Science.gov (United States)

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter.

  17. Directing migration of endothelial progenitor cells with applied DC electric fields.

    Science.gov (United States)

    Zhao, Zhiqiang; Qin, Lu; Reid, Brian; Pu, Jin; Hara, Takahiko; Zhao, Min

    2012-01-01

    Naturally-occurring, endogenous electric fields (EFs) have been detected at skin wounds, damaged tissue sites and vasculature. Applied EFs guide migration of many types of cells, including endothelial cells to migrate directionally. Homing of endothelial progenitor cells (EPCs) to an injury site is important for repair of vasculature and also for angiogenesis. However, it has not been reported whether EPCs respond to applied EFs. Aiming to explore the possibility to use electric stimulation to regulate the progenitor cells and angiogenesis, we tested the effects of direct-current (DC) EFs on EPCs. We first used immunofluorescence to confirm the expression of endothelial progenitor markers in three lines of EPCs. We then cultured the progenitor cells in EFs. Using time-lapse video microscopy, we demonstrated that an applied DC EF directs migration of the EPCs toward the cathode. The progenitor cells also align and elongate in an EF. Inhibition of vascular endothelial growth factor (VEGF) receptor signaling completely abolished the EF-induced directional migration of the progenitor cells. We conclude that EFs are an effective signal that guides EPC migration through VEGF receptor signaling in vitro. Applied EFs may be used to control behaviors of EPCs in tissue engineering, in homing of EPCs to wounds and to an injury site in the vasculature.

  18. Expression of DC-SIGN and DC-SIGNRs in placentas of HIV-positive patients

    Directory of Open Access Journals (Sweden)

    Komala Pillay

    2014-09-01

    Full Text Available Background. Human dendritic cell-specific intracellular adhesion molecule-3 (ICAM3-grabbing non-integrin (DC-SIGN is a mannose-binding lectin that initiates interaction between dendritic cells and resting T-lymphocytes. DC-SIGN is highly expressed in placental tissue on dendritic cells and Hofbauer cells, and it is suggested that HIV may become adsorbed to DC-SIGN on Hofbauer cells as part of the mechanism of mother-to-child HIV transmission. A possible mechanism of transfer of the virus from the Hofbauer cells to the fetus is the subsequent adsorption to DC-SIGN-related molecules (DC-SIGNRs, present on immediately adjacent capillary vascular endothelium. However, data on DC-SIGN and DC-SIGNR expression in the placenta are few.Methods. Forty term placentas from HIV-positive mothers and 21 term placentas from HIV-negative mothers underwent immunohistochemistry staining for DC-SIGN and DC-SIGNR expression. Five random sets of 10 villi were assessed, and the average number of positive cells were counted in each case. In addition, where possible, maternal and cord blood viral loads and maternal CD4+ counts were performed in the HIV-positive group only.Results. The median maternal CD4+ count was 377 cells/µl and 27% of participants had undetectable viral loads; the median detectable viral load was 3.72 log. Most (97% of the cord bloods tested in infants from HIV-positive mothers had lower than detectable viral loads. HIV-positive cases had significantly greater expression of both DC-SIGNRs (median values in HIV-positive cases, 14.5 positive cells/10 villi (pc/10villi, compared with 11 pc/10villi in HIV-negative cases, p=0.020 and DC-SIGN (median value in HIV-positive cases, 26.5 pc/10villi, compared with 23 pc/10villi in HIV-negative cases, p=0.037. DC-SIGNR expression was also noted in Hofbauer cells and decidual macrophages in addition to endothelium (reported currently. There was no difference in expression of DC-SIGN and DC-SIGNRs in patients

  19. Multiphase soft switched DC/DC converter and active control technique for fuel cell ripple current elimination

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Jih-Sheng (Blacksburg, VA); Liu, Changrong (Sunnyvale, CA); Ridenour, Amy (Salem, VA)

    2009-04-14

    DC/DC converter has a transformer having primary coils connected to an input side and secondary coils connected to an output side. Each primary coil connects a full-bridge circuit comprising two switches on two legs, the primary coil being connected between the switches on each leg, each full-bridge circuit being connected in parallel wherein each leg is disposed parallel to one another, and the secondary coils connected to a rectifying circuit. An outer loop control circuit that reduces ripple in a voltage reference has a first resistor connected in series with a second resistor connected in series with a first capacitor which are connected in parallel with a second capacitor. An inner loop control circuit that reduces ripple in a current reference has a third resistor connected in series with a fourth resistor connected in series with a third capacitor which are connected in parallel with a fourth capacitor.

  20. Brugia malayi infective larvae fail to activate Langerhans cells and dermal dendritic cells in human skin.

    Science.gov (United States)

    Cotton, R N; McDonald-Fleming, R; Boyd, A; Spates, K; Nutman, T B; Tolouei Semnani, R

    2015-02-01

    Filarial infection in humans is initiated when a mosquito deposits third-stage parasite larvae (L3) in the skin. Langerhans cells (LCs) and dermal dendritic cells (DDCs) are the first cells that the parasite encounters, and L3s must evade these highly effective antigen-presenting cells to establish infection. To assess LC and DDC responses to L3 in human skin, we employed three models of increasing physiologic relevance: in vitro-generated LCs, epidermal blister explants and full-thickness human skin sections. In vitro-generated LCs expressed TLR1-10 and robustly produced IL-6 and TNF-α in response to PolyI:C, but pre-exposure to L3s did not alter inflammatory cytokine production or TLR expression. L3s did not modulate expression of LC markers CDH1, CD207, or CD1a, or the regulatory products TSLP or IDO in epidermal explants or in vitro-generated LC. LC, CD14+ DDC, CD1c+ DC and CD141+ DC from human skin sections were analysed by flow cytometry. While PolyI:C potently induced CCL22 production in LC, CD1c+ DC, and CD141+ DC, and IL-10 production in LC, L3s did not modulate the numbers of or cytokine production by any skin DC subset. L3s broadly failed to activate or modulate LCs or DDCs, suggesting filarial larvae expertly evade APC detection in human skin.

  1. Impute DC link (IDCL) cell based power converters and control thereof

    Energy Technology Data Exchange (ETDEWEB)

    Divan, Deepakraj M.; Prasai, Anish; Hernendez, Jorge; Moghe, Rohit; Iyer, Amrit; Kandula, Rajendra Prasad

    2016-04-26

    Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.

  2. Genetically Modified Lactococcus lactis for Delivery of Human Interleukin-10 to Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Inge L. Huibregtse

    2012-01-01

    Full Text Available Interleukin-10 (IL-10 plays an indispensable role in mucosal tolerance by programming dendritic cells (DCs to induce suppressor Th-cells. We have tested the modulating effect of L. lactis secreting human IL-10 (L.  lactisIL-10 on DC function in vitro. Monocyte-derived DC incubated with L.  lactisIL-10 induced effector Th-cells that markedly suppressed the proliferation of allogenic Th-cells as compared to L. lactis. This suppressive effect was only seen when DC showed increased CD83 and CD86 expression. Furthermore, enhanced production of IL-10 was measured in both L.  lactisIL-10-derived DC and Th-cells compared to L. lactis-derived DC and Th-cells. Neutralizing IL-10 during DC-Th-cell interaction and coculturing L.  lactisIL-10-derived suppressor Th-cells with allogenic Th-cells in a transwell system prevented the induction of suppressor Th-cells. Only 130 pg/mL of bacterial-derived IL-10 and 40 times more exogenously added recombinant human IL-10 were needed during DC priming for the generation of suppressor Th-cells. The spatially restricted delivery of IL-10 by food-grade bacteria is a promising strategy to induce suppressor Th-cells in vivo and to treat inflammatory diseases.

  3. Correlation between Expression of DcR3 on Tumor Cells and Sensitivity to FasL

    Institute of Scientific and Technical Information of China (English)

    Wenzhu Li; Changgong Zhang; Caixia Chen; Guohong Zhuang

    2007-01-01

    To investigate the correlation between sensitivity to Fas ligand (FasL) and expression level of decoy receptor 3(DcR3) on tumor cell surface, Fas/DcR3 mRNA expression was detected by RT-PCR. Anti-DcR3 mAb was used to detect expression level of DcR3 on surface of tumor cells by flow cytometry. Caspase-8, caspase-9, caspase-3, Bcl-2expressions were analyzed by Western blot, respectively. Sensitivity to apoptosis induced by FasL was determined by Annexin V apoptosis kit. The expressions of DcR3 on the surface of tumor cells from high to low were approximately 35.3% in BGC823 cells, and 21.6% in MCF-7 cells, respectively. The apoptotic rates induced by FasL from low to high were 15.6% in BGC823 cells, and 58.2% in MCF-7 cells, respectively. There was a significant correlation between the expression levels of DcR3 with FasL-inducing apoptosis.

  4. Monitoring the initiation and kinetics of human dendritic cell-induced polarization of autologous naive CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Tammy Oth

    Full Text Available A crucial step in generating de novo immune responses is the polarization of naive cognate CD4+ T cells by pathogen-triggered dendritic cells (DC. In the human setting, standardized DC-dependent systems are lacking to study molecular events during the initiation of a naive CD4+ T cell response. We developed a TCR-restricted assay to compare different pathogen-triggered human DC for their capacities to instruct functional differentiation of autologous, naive CD4+ T cells. We demonstrated that this methodology can be applied to compare differently matured DC in terms of kinetics, direction, and magnitude of the naive CD4+ T cell response. Furthermore, we showed the applicability of this assay to study the T cell polarizing capacity of low-frequency blood-derived DC populations directly isolated ex vivo. This methodology for addressing APC-dependent instruction of naive CD4+ T cells in a human autologous setting will provide researchers with a valuable tool to gain more insight into molecular mechanisms occurring in the early phase of T cell polarization. In addition, it may also allow the study of pharmacological agents on DC-dependent T cell polarization in the human system.

  5. Converter DC/AC Multilevel of Three Cells: Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    Julián Peláez-Restrepo

    2013-11-01

    Full Text Available This paper presents a three-cell converter DC / AC. Multilevel topologies are attracting attention in the industry, obtained as a ripple on the state variables much smaller, and reduces stress on the switching devices. The topology used in this work is known in the technical literature as floating capacitor multilevel inverter, which imposes the challenge of balancing the voltage across each cell switching using floating capacitors, besides obtaining a sinusoidal signal regulated. The paper presents the averaged model of the inverter, and results obtained through simulation.

  6. A Rapid Culture Technique Produces Functional Dendritic-Like Cells from Human Acute Myeloid Leukemia Cell Lines

    Directory of Open Access Journals (Sweden)

    Jian Ning

    2011-01-01

    Full Text Available Most anti-cancer immunotherapeutic strategies involving dendritic cells (DC as vaccines rely upon the adoptive transfer of DC loaded with exogenous tumour-peptides. This study utilized human acute myeloid leukemia (AML cells as progenitors from which functional dendritic-like antigen presenting cells (DLC were generated, that constitutively express tumour antigens for recognition by CD8+ T cells. DLC were generated from AML cell lines KG-1 and MUTZ-3 using rapid culture techniques and appropriate cytokines. DLC were evaluated for their cell-surface phenotype, antigen uptake and ability to stimulate allogeneic responder cell proliferation, and production of IFN-γ; compared with DC derived from normal human PBMC donors. KG-1 and MUTZ-3 DLC increased expression of CD80, CD83, CD86, and HLA-DR, and MUTZ-3 DLC downregulated CD14 and expressed CD1a. Importantly, both KG-1 and MUTZ-3-derived DLC promoted proliferation of allogeneic responder cells more efficiently than unmodified cells; neither cells incorporated FITC-labeled dextran, but both stimulated IFN-γ production from responding allogeneic CD8+ T cells. Control DC produced from PBMC using the FastDC culture also expressed high levels of critical cell surface ligands and demonstrated good APC function. This paper indicates that functional DLC can be cultured from the AML cell lines KG-1 and MUTZ-3, and FastDC culture generates functional KG-1 DLC.

  7. Methanolic extract of Pereskia bleo (Kunth) DC. (Cactaceae) induces apoptosis in breast carcinoma, T47-D cell line.

    Science.gov (United States)

    Tan, M L; Sulaiman, S F; Najimuddin, N; Samian, M R; Muhammad, T S Tengku

    2005-01-04

    Currently, breast cancer is the leading cause of cancer-related death in women. Therefore, there is an urgent need to develop alternative therapeutic measures against this deadly disease. Here, we report the cytotoxicity activity and the mechanism of cell death exhibited by the methanol extract prepared from Pereskia bleo (Kunth) DC. (Cactaceae) plant against human breast carcinoma cell line, T-47D. In vitro cytotoxicity screening of methanol extract of Pereskia bleo plant indicated the presence of cytotoxicity activity of the extract against T-47D cells with EC50 of 2.0 microg/ml. T-47D cell death elicited by the extract was found to be apoptotic in nature based a clear indication of DNA fragmentation which is a hallmark of apoptosis. In addition, ultrastructural analysis also revealed apoptotic characteristics (the presence of chromatin margination and apoptotic bodies) in the extract-treated cells. RT-PCR analysis showed the mRNA expression levels of c-myc, and caspase 3 were markedly increased in the cells treated with the plant extract. However, p53 expression was only slightly increased as compared to caspase 3 and c-myc. Thus, the results from this study strongly suggest that the methanol extract of Pereskia bleo may contain bioactive compound(s) that caused breast carcinoma, T-47D cell death by apoptosis mechanism via the activation of caspase-3 and c-myc pathways.

  8. PWM DC/DC Converter

    OpenAIRE

    Chen, Juan

    2008-01-01

    This report is the result of a Master Thesis work done at Seaward Electronics Inc. in Beijing, China from June to December in 2007. The main goal for this thesis is to verify and improve the performance of Honey-PWM DC-DC converter, which has been fabricated by a standard 0.6um CMOS processes. The project was started with studying of Buck converter structure. After the understanding of the converter structure, the project goes in to the analyses phase for each sub-cells, including the theory,...

  9. C5a regulates IL-12+ DC migration to induce pathogenic Th1 and Th17 cells in sepsis.

    Directory of Open Access Journals (Sweden)

    Ning Ma

    Full Text Available OBJECTIVE: It is well known that complement system C5a is excessively activated during the onset of sepsis. However, it is unclear whether C5a can regulate dentritic cells (DCs to stimulate adaptive immune cells such as Th1 and Th17 in sepsis. METHODS: Sepsis was induced by cecal ligation and puncture (CLP. CLP-induced sepsis was treated with anti-C5a or IL-12. IL-12(+DC, IFNγ(+Th1, and IL-17(+Th17 cells were analyzed by flow cytometry. IL-12 was measured by ELISA. RESULTS: Our studies here showed that C5a induced IL-12(+DC cell migration from the peritoneal cavity to peripheral blood and lymph nodes. Furthermore, IL-12(+DC cells induced the expansion of pathogenic IFNγ(+Th1 and IL-17(+Th17 cells in peripheral blood and lymph nodes. Moreover, IL-12, secreted by DC cells in the peritoneal cavity, is an important factor that prevents the development of sepsis. CONCLUSION: Our data suggests that C5a regulates IL-12(+DC cell migration to induce pathogenic Th1 and Th17 cells in sepsis.

  10. Human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem; Kassem, Moustapha

    2008-01-01

    Mesenchymal stem cells (MSC) are a group of clonogenic cells present among the bone marrow stroma and capable of multilineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. Due to their ease of isolation and their differentiation potential, MSC are being...... introduced into clinical medicine in variety of applications and through different ways of administration. Here, we discuss approaches for isolation, characterization and directing differentiation of human mesenchymal stem cells (hMSC). An update of the current clinical use of the cells is also provided....

  11. Tobacco Mosaic Virus Efficiently Targets DC uptake, Activation and Antigen-specific T Cell Responses in vivo

    Science.gov (United States)

    Kemnade, Jan Ole; Seethammagari, Mamatha; Collinson-Pautz, Mathew; Kaur, Hardeep; Spencer, David M.

    2015-01-01

    Over the past 20 years, dendritic cells (DCs) have been utilized to activate immune responses capable of eliminating cancer cells. Currently, ex vivo DC priming has been the mainstay of DC cancer immunotherapies. However, cell-based treatment modalities are inherently flawed due to a lack of standardization, specialized facilities and personnel, and cost. Therefore, direct modes of DC manipulation, circumventing the need for ex vivo culture, must be investigated. To facilitate the development of next-generation, in vivo targeted DC vaccines, we characterized the DC interaction and activation potential of the Tobacco Mosaic virus (TMV), a plant virus that enjoys a relative ease of production and the ability to deliver protein payloads via surface conjugation. In this study we show that TMV is readily taken up by mouse bone marrow-derived DCs, in vitro. Footpad injection of fluorophore-labeled TMV reveals preferential uptake by draining lymph node resident DCs in vivo. Uptake leads to activation, as measured by the upregulation of key DC surface markers. When peptide antigen-conjugated TMV is injected into the footpad of mice, DC-mediated uptake and activation leads to robust antigen-specific CD8+ T cell responses, as measured by antigen-specific tetramer analysis. Remarkably, TMV priming induced a greater magnitude T cell response than Adenovirus (Ad) priming. Finally, TMV is capable of boosting either Ad-induced or TMV-induced antigen-specific T cell responses, demonstrating that TMV, uniquely, does not induce neutralizing self-immunity. Overall, this study elucidates the in vivo DC delivery and activation properties of TMV, and indicates its potential as a vaccine vector in stand alone or prime-boost strategies. PMID:24923637

  12. Optimal State Feedback Control Design and Stability Analysis of Boost DC-DC Converters in Fuel Cell Power Systems Using PSO

    Directory of Open Access Journals (Sweden)

    A.R Alfi

    2012-06-01

    Full Text Available This paper presents an intelligent optimal design control strategy for current and voltage of boost DC-DC convertors in fuel cell power systems by considering detailed model for different operating points. The proposed control strategy is designed based on a state feedback whereas the controllability and the stability region are analyzed. Moreover, in order to determine of the optimal coefficients of state feedback and zero steady state error in voltage signal, in the core of the proposed control method a heuristic algorithm namely Particle Swarm Optimization (PSO is utilized. The results are presented in the different load conditions. In order to show the feasibility of the proposed control strategy, the controller is implemented both average model and detailed model of convertor and the results are compared.

  13. Medroxyprogesterone acetate impairs human dendritic cell activation and function.

    Science.gov (United States)

    Quispe Calla, N E; Ghonime, M G; Cherpes, T L; Vicetti Miguel, R D

    2015-05-01

    Does medroxyprogesterone acetate (MPA) impair human dendritic cell (DC) activation and function? In vitro MPA treatment suppressed expression of CD40 and CD80 by human primary DCs responding to Toll-like receptor 3 (TLR3) agonist stimulation (i.e. DC activation). Moreover, this MPA-mediated decrease in CD40 expression impaired DC capacity to stimulate T cell proliferation (i.e. DC function). MPA is the active molecule in Depo-Provera(®) (DMPA), a commonly used injectable hormonal contraceptive (HC). Although DMPA treatment of mice prior to viral mucosal tissue infection impaired the capacity of DCs to up-regulate CD40 and CD80 and prime virus-specific T cell proliferation, neither DC activation marker expression nor the ability of DCs to promote T cell proliferation were affected by in vitro progesterone treatment of human DCs generated from peripheral blood monocytes. This cross-sectional study examined MPA-mediated effects on the activation and function of human primary untouched peripheral blood DCs. Human DCs isolated from peripheral blood mononuclear cells by negative immunomagnetic selection were incubated for 24 h with various concentrations of MPA. After an additional 24 h incubation with the TLR3 agonist polyinosinic:polycytidylic acid (poly I:C), flow cytometry was used to evaluate DC phenotype (i.e. expression of CD40, CD80, CD86, and HLA-DR). In separate experiments, primary untouched human DCs were sequentially MPA-treated, poly I:C-activated, and incubated for 7 days with fluorescently labeled naïve allogeneic T cells. Flow cytometry was then used to quantify allogeneic T cell proliferation. Several pharmacologically relevant concentrations of MPA dramatically reduced CD40 and CD80 expression in human primary DCs responding to the immunostimulant poly I:C. In addition, MPA-treated DCs displayed a reduced capacity to promote allogeneic CD4(+) and CD8(+) T cell proliferation. In other DC: T cell co-cultures, the addition of antibody blocking the CD40

  14. Immunoregulatory effects of freeze injured whole tumour cells on human dendritic cells using an in vitro cryotherapy model.

    Science.gov (United States)

    Ismail, Mohamed; Morgan, Richard; Harrington, Kevin; Davies, John; Pandha, Hardev

    2010-12-01

    Tumour cryotherapy has been described as both immunostimulatory and immunoinhibitory in previous studies. However, previous studies have not accurately reproduced the precise conditions of current clinical cryotherapy. The objective of this study is to assess the immunological effects of cryotreated whole tumour cells on dendritic cells (DC) maturation and function using an in vitro model. Prostate cancer cells were cooled using Endocare cryo-system to mimic temperatures achieved during clinical cryotherapy. Human DC were prepared from cluster of differentiation (CD) 14 monocytes and matured with lipopolysaccharide (LPS). Cryotreated cancer cells were added to DC on day 3. On day 7, DC were harvested and phenotyped. Cytokine gene expression was assessed using real time quantitative polymerase chain reaction (RT-PCR). Functional activity of DC was assessed in allogenic mixed lymphocyte reaction (MLR) and the molecular changes using gene microarray technology. There was statistically significant upregulation of costimulatory molecules and maturation markers (CD86, CD83, CD80 and CL II) in DC loaded with cryotreated whole tumour cells compared to both control DC and DC matured with LPS (P cells are exposed to sub-lethal temperature.

  15. Immature human dendritic cells enhance their migration through KCa3.1 channel activation.

    Science.gov (United States)

    Crottès, David; Félix, Romain; Meley, Daniel; Chadet, Stéphanie; Herr, Florence; Audiger, Cindy; Soriani, Olivier; Vandier, Christophe; Roger, Sébastien; Angoulvant, Denis; Velge-Roussel, Florence

    2016-04-01

    Migration capacity is essential for dendritic cells (DCs) to present antigen to T cells for the induction of immune response. The DC migration is supposed to be a calcium-dependent process, while not fully understood. Here, we report a role of the KCa3.1/IK1/SK4 channels in the migration capacity of both immature (iDC) and mature (mDC) human CD14(+)-derived DCs. KCa3.1 channels were shown to control the membrane potential of human DC and the Ca(2+) entry, which is directly related to migration capacities. The expression of migration marker such as CCR5 and CCR7 was modified in both types of DCs by TRAM-34 (100nM). But, only the migration of iDC was decreased by use of both TRAM-34 and KCa3.1 siRNA. Confocal analyses showed a close localization of CCR5 with KCa3.1 in the steady state of iDC. Finally, the implication of KCa3.1 seems to be limited to the migration capacities as T cell activation of DCs appeared unchanged. Altogether, these results demonstrated that KCa3.1 channels have a pro-migratory effect on iDC migration. Our findings suggest that KCa3.1 in human iDC play a major role in their migration and constitute an attractive target for the cell therapy optimization.

  16. Maturation of dendritic cells by recombinant human CD40L-trimer leads to a homogeneous cell population with enhanced surface marker expression and increased cytokine production

    DEFF Research Database (Denmark)

    Würtzen, P A; Nissen, Mogens Holst; Claesson, M H

    2001-01-01

    . Effective differentiation of monocytes derived from freshly isolated peripheral blood mononuclear cells (PBMC) was obtained with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4. The DC expression of human leucocyte antigen (HLA) molecules, CD80, CD83, and CD86 was markedly......-cell activating capacity of the DC. We studied DC phenotype and cytokine production as well as the T-cell proliferation and cytotoxic T lympocyte (CTL) activation induced by DC generated in vitro. In addition, the effect of exposure to recombinant human CD40L-trimer (huCD40LT) on these parameters was investigated...... marker expression and high production of pro-inflammatory cytokines. In addition, the induction of responses to allo or recall antigens presented by huCD40LT maturated DC was comparable to the responses obtained with the DC maturated through TNF-alpha exposure....

  17. Dual-Input Soft-Switched DC-DC Converter with Isolated Current-Fed Half-Bridge and Voltage-Fed Full-Bridge for Fuel Cell or Photovoltaic Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    This paper introduces a new zero-voltage-switching (ZVS) isolated DC-DC converter with two input ports which can be utilized in hybrid energy systems, for instance, in a fuel cell and super-capacitor system. By fully using two high frequency transformers, the proposed converter can effectively...

  18. Isolation and culture of human hematopoietic progenitors for studies of dendritic cell biology.

    Science.gov (United States)

    Svensson, Mattias

    2009-01-01

    Understanding the regulation of distinct dendritic cell (DC) function and differentiation pathways is important in many physiological and pathophysiological processes. This includes infectious and neoplastic diseases, vaccination and immunotherapy, allograft rejection, and the pathogenesis of autoimmune diseases. Isolation and culture of human hematopoietic progenitor cells provide a valuable model for studies on DC biology and may help uncover new means to manipulate DC differentiation and function in therapeutic settings. Here, a detailed protocol for the isolation of CD34+ hematopoietic progenitor cells from human cord blood is described. The isolated cell population consists of approximately 85% CD34+ CD45+ hematopoietic progenitor cells that in response to granulocyte-macrophage colony-stimulating factor (GM-CSF) plus tumor necrosis factor (TNF) expand and differentiate into CD11c+ HLA-DR+ DC-expressing CD1a.

  19. Interleaved soft-switched active-clamped L-L type current-fed half-bridge DC-DC converter for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Rathore, Akshay K. [Electrical Machines and Drives Research Lab, University of Wuppertal, Rainer Gruenter Str. 21, University Campus Freudenberg, 42119 Wuppertal, NRW (Germany)

    2009-12-15

    In this paper, an interleaved soft-switched active-clamped L-L type current-fed half-bridge isolated dc-dc converter has been proposed. The L-L type active-clamped current-fed converter is able to maintain zero-voltage switching (ZVS) of all switches for the complete operating range of wide fuel cell stack voltage variation at full load down to light load conditions. Active-clamped circuit absorbs the turn-off voltage spike across the switches. Half-bridge topology maintains higher efficiency due to lower conduction losses. Soft-switching permits higher switching frequency operation, reducing the size, weight and cost of the magnetic components. Interleaving of the two isolated converters is done using parallel input series output approach and phase-shifted modulation is adopted. It reduces the input current ripple at the fuel cell input, which is required in a fuel cell system and also reduces the output voltage ripples. In addition, the size of the magnetic/passive components, current rating of the switches and voltage ratings of the rectifier diodes are reduced. (author)

  20. Killing effect of CIK cells and DC-CIK cells on neuroblastoma cells%CIK、DC-CIK细胞对神经母细胞瘤细胞杀伤作用的研究

    Institute of Scientific and Technical Information of China (English)

    邢准; 王秋实; 佟海侠

    2014-01-01

    Objective:To study the killing effects on neuroblastoma( NB)cells of cytokine-induced killer cells ( CIK)co-cultured with dendritic cells( DC). Methods:Peripheral blood mononuelear cells( PBMC)were isolated from healthy subjects and tumor patients. DC and CIK cells were induced by different cytokines. The phenotypes of CIK and DC cells before and after culture were determined by flow cytometry. The killing activity of different CIK groups against NB was determined by MTT. Results:The percentage of CD3+CD56+ cells as well as the cytotoxicity activity of CIK cells originated from PBMC of peripheral blood of healthy people were significantly higher than those of tumor patients(P<0. 05). In addition,compared with CIK cells,the DC-CIK cells presented a significantly higher killing effects on NB cells(P<0. 05). Conclusion:DC-CIK cell is a kind of immune cell which has a higher cyto-toxicity than that in CIK cell. CIK cells generated from PBMC of healthy subjects and tumor patients have significant differences,and provide further experimental basis for improving the clinical curative effect of CIK cells.%目的:研究细胞因子诱导的杀伤细胞( CIK)与树突状细胞( DC)共培养后对神经母细胞瘤( neuro-blastoma,NB)细胞株的杀伤作用。方法:取健康人和肿瘤患者外周血单个核细胞( PBMC),加入不同的细胞因子分别诱导出DC和CIK细胞,用流式细胞术测定诱导培养前后DC和CIK细胞的表型,MTT法测定不同组CIK细胞对NB细胞株的杀伤活性。结果:流式细胞仪检测健康人PBMC培养后CD3+CD56+淋巴细胞百分比以及对NB细胞株的杀伤活性均显著高于肿瘤患者( P<0.05)。此外,与单纯CIK细胞相比,DC-CIK细胞具有更强的杀伤NB细胞株的活性( P<0.05)。结论:DC-CIK细胞是一种细胞毒作用高于单纯CIK细胞的免疫活性细胞。健康人和肿瘤患者的PBMC经诱导培养获得的CIK细胞有显著差别,为临床进

  1. The Structure and Properties of Pulsed dc Sputtered Nanocrystalline NbN Coatings for Proton Exchange Membrane Fuel Cell.

    Science.gov (United States)

    Chun, Sung-Yong

    2016-02-01

    Niobium nitride coatings for the surface modified proton exchange membrane fuel cells with various pulse parameters have been prepared using dc (direct current) and asymmetric-bipolar pulsed dc magnetron sputtering. The pulse frequency and the duty cycle were varied from 5 to 50 kHz and 50 to 95%, respectively. The deposition rate, grain size and resistivity of pulsed dc sputtered films were decreased when the pulse frequency increased, while the nano hardness of niobium nitride films increased. We present in detail coatings (e.g., deposition rate, grain size, prefer-orientation, resistivity and hardness). Our studies show that niobium nitride coatings with superior properties can be prepared using asymmetric-bipolar pulsed dc sputtering.

  2. DC-based immunotherapy for hematological malignancies.

    Science.gov (United States)

    Kitawaki, Toshio

    2014-02-01

    Great advances have been made in the treatment of hematological malignancies, but achieving a definitive cure remains an elusive goal for the majority of patients. Antigen-specific tumor immunotherapy has the potential to improve clinical outcome in patients with such diseases by eradicating chemotherapy-resistant tumor cell clones without damaging normal tissues. Dendritic cells (DCs) serve as an essential link between the innate and the adaptive immune systems, acting as key controllers of antigen-specific T cell responses. Molecular identification of tumor-specific antigens recognized by T lymphocytes and technical advances in ex vivo generation of human DCs has enabled us to develop DC-based tumor immunotherapies (also called "DC vaccines"). To date, a large number of clinical trials of DC vaccines have been conducted for a variety of tumors, including hematological malignancies. Overall, these trials have demonstrated that DC vaccines have excellent safety profiles, moderate immunological activity, and mild clinical efficacy. To establish a role for DC vaccines in the treatment of hematological malignancies, we need both to define patient populations that can obtain clinical benefit from DC vaccines and to develop combination therapies that augment clinical efficacy of DC vaccines. In this review, I will describe current status of DC-based immunotherapy for hematological malignancies, and discuss future perspectives in this field.

  3. HCV and HIV binding lectin, DC-SIGNR, is expressed at all stages of HCV induced liver disease.

    Science.gov (United States)

    Cole, G; Coleman, N; Soilleux, E

    2004-01-01

    The process by which hepatitis C virus (HCV) enters cells and the reason for its hepatotropism remain obscure. Recently, the human immunodeficiency virus (HIV) binding lectins, DC-SIGN and DC-SIGNR, were shown to bind HCV. This article reports the expression of DC-SIGN and DC-SIGNR in HCV related liver disease and discusses whether these lectins, in particular DC-SIGNR, are responsible for HCV hepatotropism.

  4. DcR3 binds to ovarian cancer via heparan sulfate proteoglycans and modulates tumor cells response to platinum with corresponding alteration in the expression of BRCA1

    Directory of Open Access Journals (Sweden)

    Connor Joseph P

    2012-05-01

    Full Text Available Abstract Background Overcoming platinum resistance is a major obstacle in the treatment of Epithelial Ovarian Cancer (EOC. In our previous work Decoy Receptor 3 (DcR3 was found to be related to platinum resistance. The major objective of this work was to define the cellular interaction of DcR3 with EOC and to explore its effects on platinum responsiveness. Methods We studied cell lines and primary cultures for the expression of and the cells ability to bind DcR3. Cells were cultured with DcR3 and then exposed to platinum. Cell viability was determined by MTT assay. Finally, the cells molecular response to DcR3 was studied using real time RT-PCR based differential expression arrays, standard RT-PCR, and Western blot. Results High DcR3 in the peritoneal cavity of women with EOC is associated with significantly shorter time to first recurrence after platinum based therapy (p = 0.02. None-malignant cells contribute DcR3 in the peritoneal cavity. The cell lines studied do not secrete DcR3; however they all bind exogenous DcR3 to their surface implying that they can be effected by DcR3 from other sources. DcR3s protein binding partners are minimally expressed or negative, however, all cells expressed the DcR3 binding Heparan Sulfate Proteoglycans (HSPGs Syndecans-2, and CD44v3. DcR3 binding was inhibited by heparin and heparinase. After DcR3 exposure both SKOV-3 and OVCAR-3 became more resistant to platinum with 15% more cells surviving at high doses. On the contrary CaOV3 became more sensitive to platinum with 20–25% more cell death. PCR array analysis showed increase expression of BRCA1 mRNA in SKOV-3 and OVCAR-3 and decreased BRCA1 expression in CaOV-3 after exposure to DcR3. This was confirmed by gene specific real time PCR and Western blot analysis. Conclusions Non-malignant cells contribute to the high levels of DcR3 in ovarian cancer. DcR3 binds readily to EOC cells via HSPGs and alter their responsiveness to platinum chemotherapy. The

  5. The study on specific umbilical blood Dc vaccine for Beige nude mice loaded human colorectal carcinoma to induce anti-tumor immunity.

    Science.gov (United States)

    Fu, Z-X; Han, J-S; Liu, F; Zhao, Z-L; Li, D-B; Shi, L; Dong, J-T; Zhou, Y; Cai, J-H

    2017-05-01

    This study is to observe the immunosuppression of CD137L transfected umbilical blood Dcs (Dendritic cell) vaccine to tumor development of SCID/ Beige nude mice. Samples of umbilical blood in the childbirth pregnant women were collected by density gradient centrifugation. Umbilical cord blood dendritic cells (Dcs) were transfected by specific CD137L via LipofectamineTM method and cells were harvested. Meanwhile, the peripheral blood of volunteers was collected to isolate Dcs, the Dcs were cultured for 5 days and hatched with SW-1116 cells antigen. The mature Dcs were harvested. The male SCID/Beige nude mice were subcutaneously injected with human SW-1116 cells in axillary to build colorectal carcinoma model as blank control (Blank). The naked peripheral blood Dc vaccine group (cPBMCs), the SW-1116 antigen-specific peripheral blood Dc vaccine group (pDcs) and the CD137L specific umbilical blood Dc vaccine group (tuDcs) were injected 24 h before tumor cells injection, respectively to recur the humanized immune reconstruction. The general life, living habits changes, tumor growing time and tumor size were observed. The nude mice were sacrificed 18 days after tumor formation. The tumor size, mice weight, in vitro tumor weight, liver weight and spleen weight of mice were recorded to evaluate the anti-tumor effect of the specific immune cells. The nude mice in pDcs group showed better general living condition, slower tumor growth, smaller tumor volume and no ulceration, necrosis, and death in nude mice. The tumor formation time in different groups was 4.71 ± 0.18 ds (blank), 7.71 ± 0.29 ds (cPBMCs), 7.86 ± 0.26 ds (pDcs) and 8.14 ± 0.69 ds (tuDcs) respectively. There were significant differences between blank and other three groups (F = 40.96, p human colon cancer in nude mice via increasing the number of immune effector cell in tumor microenvironment.

  6. Design and Simulation of Dc-Dc Converter for Fuel Cell Operated Vehicle with Single Reference Six Pulse Modulation

    OpenAIRE

    2015-01-01

    : Even though electrical vehicle concept is introduced in early 1800’s, it gained importance in past couple of decades due to growing conscience on environmental aspects. Different types of electrical vehicles are manufactured in the past centuries and now onboard generation is seems to be promising by fulfilling the needs of a vehicle. Fuel cells or fuel cell stack produces typically 32-68V of EMF, which has to be conditioned before it fed to motor. The conditioning invo...

  7. TLR9-dependent recognition of MCMV by IPC and DC generates coordinated cytokine responses that activate antiviral NK cell function.

    Science.gov (United States)

    Krug, Anne; French, Anthony R; Barchet, Winfried; Fischer, Jens A A; Dzionek, Andrzej; Pingel, Jeanette T; Orihuela, Michael M; Akira, Shizuo; Yokoyama, Wayne M; Colonna, Marco

    2004-07-01

    Natural interferon-producing cells (IPC) respond to viruses by secreting type I interferon (IFN) and interleukin-12 (IL-12). Toll-like receptor (TLR) 9 mediates IPC recognition of some of these viruses in vitro. However, whether TLR9-induced activation of IPC is necessary for an effective antiviral response in vivo is not clear. Here, we demonstrate that IPC and dendritic cells (DC) recognize murine cytomegalovirus (MCMV) through TLR9. TLR9-mediated cytokine secretion promotes viral clearance by NK cells that express the MCMV-specific receptor Ly49H. Although depletion of IPC leads to a drastic reduction of the IFN-alpha response, this allows other cell types to secrete IL-12, ensuring normal IFN-gamma and NK cell responses to MCMV. We conclude that the TLR9/MyD88 pathway mediates antiviral cytokine responses by IPC, DC, and possibly other cell types, which are coordinated to promote effective NK cell function and MCMV clearance.

  8. Interferon γ Stimulates Cellular Maturation of Dendritic Cell Line DC2.4 Leading to Induction of Efficient Cytotoxic T Cell Responses and Antitumor Immunity

    Institute of Scientific and Technical Information of China (English)

    Tianpei He; Chaoke Tang; Shulin Xu; Terence Moyana; Jim Xiang

    2007-01-01

    Dendritic cells (DCs) are the most potent antigen-presenting cells (APCs) for the initiation of antigen (Ag)-specific immune responses. In most studies, mature DCs are generated from bone marrow cells or peripheral monocytes; in either case, the harvested cells are then cultured in medium containing recombinant GM-CSF, IL-4 and TNF-α for 7-10 days and stimulated with lipopolysaccharide (LPS). However, this approach is time-consuming and expensive. There is another less cost approach of using immobilized DC cell lines, which can easily grow in the medium. A disadvantage with the immobilized DC cell lines, however, is that they are immature DCs and lack expression of MHC class Ⅱ and costimulatory CD40 and CD80 molecules. This, therefore, limits their capacity for inducing efficient antitumor immunity. In the current study, we investigated the possible efficacy of various stimuli (IL-1β,IFN-γ, TNF-α, CpG and LPS) in converting the immature dendritic cell line DC2.4 to mature DCs. Our findings were quite interesting since we demonstrated for the first time that IFN-γ was able to stimulate the maturation of DC2.4 cells. The IFN-γ-activated ovalbumin (OVA)-pulsed DC2.4 cells have capacity to upregulate MHC class Ⅱ,CD40, CD80 and CCR7, and to more efficiently stimulate in vitro and in vivo OVA-specific CD8+ T cell responses and antitumor immunity. Therefore, IFN-γ-activated immortal DC2.4 cells may prove to be useful in the study of DC biology and antitumor immunity.

  9. DC-SIGN:binding receptors for hepatitis C virus

    Institute of Scientific and Technical Information of China (English)

    王全楚; 冯志华; 聂青和; 周永兴

    2004-01-01

    Objective To review the recent developments in and research into binding receptors of hepatitis C virus (HCV) and especially the role of dendritic cell-specitic adhesion receptor (DC-SIGN) in HCV.Data sources Both Chinese- and English-languge literature was searched using MEDLINE (2000-2003) and the databank of Chinese-language literature (2000-2003).Study selection Relevant articles on DC-SIGN and HCV binding receptors in recent domestic and foreign literature were selected.Data extraction Data were mainly extracted from 40 articles which are listed in the references section of this review. Results DC-SIGN, a dendritic cell-specific adhesion receptor and a type Ⅱ transmembrane mannose-binding C-type lectin, is very important in the function of dendritic cells (DC), both in mediating na(I)ve T cell interactions through ICAM-3 and as a rolling receptor that mediates the DC-specific ICAM-2-dependent migration processes-It can be used by HCV and other viral and bacterial pathogens including human immunodeficiency virus (HIV), Ebola virus, CMV and Mycobacterium tuberculosis- to facilitate infection. Both DC-SIGN and DC-SIGNR can act either in cis, by concentrating virus on target cells, or in trans, by transmission of bound virus to a target cell expressing appropriate entry receptors. Recent report showed that DC-S IGN not only plays a role in entry into DC, HCV E2 interaction with DC-SIGN might also be detrimental to the interaction of DC with T cells during antigen presentation.Conclusions DC-SIGNs are high-affinity binding receptors for HCV.The clinical strategies that target DC-SIGN may be successful in restricting HCV dissemination and pathogenesis as well as directing the migration of DCs to manipulate appropriate immune responses in autoimmunity and tumorigenic situations.

  10. NADPH oxidase-2 derived ROS dictates murine DC cytokine-mediated cell fate decisions during CD4 T helper-cell commitment.

    Directory of Open Access Journals (Sweden)

    Meghan A Jendrysik

    Full Text Available NADPH oxidase-2 (Nox2/gp91(phox and p47(phox deficient mice are prone to hyper-inflammatory responses suggesting a paradoxical role for Nox2-derived reactive oxygen species (ROS as anti-inflammatory mediators. The molecular basis for this mode of control remains unclear. Here we demonstrate that IFNγ/LPS matured p47(phox-/--ROS deficient mouse dendritic cells (DC secrete more IL-12p70 than similarly treated wild type DC, and in an in vitro co-culture model IFNγ/LPS matured p47(phox-/- DC bias more ovalbumin-specific CD4(+ T lymphocytes toward a Th1 phenotype than wild type (WT DC through a ROS-dependent mechanism linking IL-12p70 expression to regulation of p38-MAPK activation. The Nox2-dependent ROS production in DC negatively regulates proinflammatory IL-12 expression in DC by constraining p38-MAPK activity. Increasing endogenous H(2O(2 attenuates p38-MAPK activity in IFNγ/LPS stimulated WT and p47(phox-/- DC, which suggests that endogenous Nox 2-derived ROS functions as a secondary messenger in the activated p38-MAPK signaling pathway during IL-12 expression. These findings indicate that ROS, generated endogenously by innate and adaptive immune cells, can function as important secondary messengers that can regulate cytokine production and immune cell cross-talk to control during the inflammatory response.

  11. Determinants of Substrate and Cation Transport in the Human Na+/Dicarboxylate Cotransporter NaDC3*

    OpenAIRE

    Schlessinger, A; Sun, NN; Colas, C; Pajor, AM

    2014-01-01

    Metabolic intermediates, such as succinate and citrate, regulate important processes ranging from energy metabolism to fatty acid synthesis. Cytosolic concentrations of these metabolites are controlled, in part, by members of the SLC13 gene family. The molecular mechanism underlying Na+-coupled di- and tricarboxylate transport by this family is understood poorly. The human Na+/dicarboxylate cotransporter NaDC3 (SLC13A3) is found in various tissues, including the kidney, liver, and brain. In a...

  12. Cell encoding recombinant human erythropoietin

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A.K.; Withy, R.M.; Zabrecky, J.R.; Masiello, N.C.

    1990-09-04

    This patent describes a C127 cell transformed with a recombinant DNA vector. It comprises: a DNA sequence encoding human erythropoietin, the transformed cell being capable of producing N-linked and O-linked glycosylated human erythropoietin.

  13. Inhibition of Growth and Induction of Apoptosis in Fibrosarcoma Cell Lines by Echinophora platyloba DC: In Vitro Analysis

    Directory of Open Access Journals (Sweden)

    Fatemeh Zare Shahneh

    2013-01-01

    Full Text Available Echinophora platyloba DC plant (Khousharizeh is one of the indigenous medicinal plants which is used as a food seasoning and medicine in Iran. The objective of this study was to examine the in vitro cytotoxic activity and the mechanism of cell death of crude methanolic extracts prepared from Echinophora platyloba DC, on mouse fibrosarcoma cell line (WEHI-164. Cytotoxicity and viability of methanolic extract was assessed by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT and dye exclusion assay. Cell death ELISA was employed to quantify the nucleosome production result from nuclear DNA fragmentation during apoptosis and determine whether the mechanism involves induction of apoptosis or necrosis. The cell death was identified as apoptosis using terminal deoxynucleotidyl transferase- (TdT- mediated dUTP nick end labeling (TUNEL assay. Our results demonstrated that the extract decreased cell viability, suppressed cell proliferation, and induced cell death in a time- and dose-dependent manner in WEHI-164 cells (IC50 = 196.673 ± 12.4 μg/mL when compared with a chemotherapeutic anticancer drug, Toxol. Observation proved that apoptosis was the major mechanism of cell death. So the Echinophora platyloba DC extract was found to time- and dose-dependently inhibit the proliferation of fibrosarcoma cell possibly via an apoptosis-dependent pathway.

  14. Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae) Sensitizes THP-1 Cells to Radiation-induced Cell Death.

    Science.gov (United States)

    Allen, Lisa; Buckner, Alison; Buckner, Carly A; Cano, Pablo; Lafrenie, Robert M

    2017-01-01

    Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae), known as Cat's Claw or Uña de gato, is a traditionally used medicinal plant native to Peru. Some studies have shown that U. tomentosa can act as an antiapoptotic agent and enhance DNA repair in chemotherapy-treated cells although others have shown that U. tomentosa enhanced apoptosis. To determine if treatment with U. tomentosa can significantly enhance cell death in THP-1 cells exposed to ionizing radiation. THP-1 monocyte-like cells were treated with ethanolic extracts of U. tomentosa in the presence or absence of bacterial lipopolysaccharide and then exposed to ionizing radiation. Cell proliferation was assessed by MTT and clonogenic assays and the effects on cell cycle measured by flow cytometry and immunoblotting. Changes in cell signaling were determined by immunoblotting and cytokine ELISA and activation of apoptosis measured by caspase activation and DNA fragmentation analysis. Treatment of THP-1 cells with U. tomentosa had a small effect on cell proliferation. However, when the U. tomentosa-pretreated cells were also subjected to 5-9 Gy ionizing radiation, they showed a significant decrease in cell proliferation and increased cellular apoptosis as measured by DNA fragmentation and caspase activation. Treatment with U. tomentosa also decreased the expression of Cyclin E and Cyclin B, key regulators of normal cell cycle progression, and decreased the phosphorylation of various stress-activated, cell survival proteins including p38, ERK, and SAP/JNK kinase. These results suggest that U. tomentosa could be useful in enhancing cell death following anticancer therapies including ionizing radiation. Treatment of THP-1 cells with Uncaria tomentosa increases their susceptibility to X-rays. The combination of Uncaria tomentosa and X-ray exposure strongly inhibits cell signaling and promotes apoptosis. Abbreviations Used: LPS: Lipopolysaccharide, TNF: Tumor necrosis factor: IL-1, Interleukin-1: SDS: Sodium

  15. The effect of HTLV-1 Tax protein on the DcR3 gene expression in T cells%HTLV-1病毒Tax蛋白对T淋巴细胞DcR3基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    吕壮伟; 牛志国; 陈丽媛; 王金恒; 陈琳; 王辉

    2011-01-01

    目的 探讨HTLV-1病毒Tax蛋白对T淋巴细胞DcR3基因表达的影响.方法 构建pGL3-DcR3-luc( -1010 bp- +114 bp)荧光素酶报告基因;利用脂质体介导的方法将pGL3 -DcR3 -luc转染到MT-2、TaxP、Jurkat细胞中,48h后检测DcR3荧光素酶报告基因的活性;利用脂质体介导的方法将梯度剂量的pCMV -Tax转染入Jurkat细胞,48 h后提RNA逆转录,real-time PCR检测DcR3 mRNA 的表达的变化;选用流式细胞技术检测MT-2、TaxP、Jurkat细胞表面DcR3蛋白的表达.结果 成功构建DcR3基因调控序列荧光素酶报告基因pGL3-DcR3-luc;荧光素酶活性的检测显示,与对照组相比,MT2细胞荧光素酶活性升高了32.07± 12.43倍,TaxP细胞荧光素酶活性升高了13.27±4.04倍,Jurkat细胞荧光素酶活性升高了1.26±0.49倍.与Jurkat细胞相比,MT2细胞和TaxP细胞的相对荧光素酶活性明显升高(P<0.01);Real-time PCR结果显示,4组Ct内参/Ct目的基因的值依次是0.40±0.02、0.44±0.01、0.47±0.02、0.53±0.02; DcR3 mRNA的表达与转染pCMV-Tax存在着剂量依赖性(P<0.05).流式细胞技术检测,MT2和TaxP细胞实验组DcR3蛋白的表达较对照组Jurkat细胞表达的高(P<0.05).MT2细胞的结果是33.1 ±9.9,TaxP细胞的结果是35.1 ±4.8,Jurkat细胞的结果是16.9±2.3.结论 Tax蛋白能够促进DcR3基因在T细胞中的表达.%Objective To explore the effect of HTLV-1 (human T-cell leukemia virus type 1 ) Tax protein on the DcR3 gene expression in T cells.Methods The construction of DcR3 (-1010 bp to +114 bp) luciferase reporter gene; MT2,TaxP,and Jurkat E6-1 cells were transfected with DcR3 luciferase reporter gene (pGL3-DcR3-1uc) using liposomes according to the manufacturer's instructions.For the control group,pGL3-basic replaced it respectively.At 48 h after incubation,luciferase activity was measured with a luciferase assay system; Jurkat cells were transfected with pCMV-Tax-Bam using liposomes,and total RNA was extracted from the

  16. Adenovirus-mediated expression of both antisense ODC and AdoMetDC inhibited colorectal cancer cell growth in vitro

    Institute of Scientific and Technical Information of China (English)

    Bing ZHANG; Xian-xi LIU; Yan ZHANG; Chun-ying JIANG; Qing-shan TENG; Hai-yan HU; Wei WANG; Lei GONG

    2006-01-01

    Aim: To construct a recombinant adenovirus that can simultaneously express both antisense ornithine decarboxylase (ODC) and adenosylmethionine decarboxylase (AdoMetDC) and detect its inhibitory effect on the intracellular polyamine pool and colorectal cancer cell growth. Methods: A 205-bp cDNA of AdoMetDC was reverse-inserted into recombinant pAdTrack-ODCas vectors and recombined with pAdEasy-1 vectors in AdEasy-1 cells. Positive clones were selected and transfected into the packaging cell HEK293 after they were linearized by Pad. Green fluorescent protein expression was used to monitor the process of adenovirus packaging. The ODC and AdoMetDC protein levels were identified by western blotting, and intracellular polyamine content was detected by reverse-phase high performance liquid chromatography. A viable cell count was used to determine the growth of HT-29 cells with or without exogenous polyamine. Results: Sequencing confirmed that AdoMetDC cDNA was successfully ligated into the pAdTrack-ODCas vector. GFP expression in 293 cells during virus packing and amplification was observed by fluorescence microscopy. Western blotting demonstrated that both ODC and AdoMetDC were downregulated by Ad-ODC-AdoMetDCas, and consequently 3 kinds of polyamine (putrescine, spermidine and spermine) were reduced to very low levels. HT-29 cell growth was significantly inhibited as compared with control conditions, and growth arrest was not reversed by exogenous putrescine. Conclusion: The successfully constructed recombinant adenovirus, Ad-ODC-AdoMetDCas, blocked polyamine synthesis and has therapeutic potential for treating colorectal cancer in vitro.

  17. Co-culture of apoptotic breast cancer cells with immature dendritic cells: a novel approach for DC-based vaccination in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jin [Department of Oncology, State Key Discipline of Cell Biology, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Department of Traditional Chinese and Western Medicine of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Liu, Qiang [Department of Hematology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Yang, Jiandong [Department of Hepatobiliary Surgery, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Ren, Qinyou [Department of Traditional Chinese and Western Medicine of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Cao, Wei [Department of Interventional Radiology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Yang, Jingyue; Yu, Zhaocai [Department of Oncology, State Key Discipline of Cell Biology, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Yu, Fang [Department of Gastrointestinal Surgery, Xijing Hospital of Digestive Diseases, the Fourth Military Medical University, Xi' an, Shaanxi (China); Wu, Yanlan [Department of Infectious Diseases, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Shi, Hengjun [Department of Traditional Chinese and Western Medicine of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Liu, Wenchao [Department of Oncology, State Key Discipline of Cell Biology, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China)

    2012-04-27

    A dendritic cell (DC)-based vaccine strategy could reduce the risk of recurrence and improve the survival of breast cancer patients. However, while therapy-induced apoptosis of hepatocellular and colorectal carcinoma cells can enhance maturation and antigen presentation of DCs, whether this effect occurs in breast cancer is currently unknown. In the present study, we investigated the effect of doxorubicin (ADM)-induced apoptotic MCF-7 breast cancer cells on the activation of DCs. ADM-induced apoptotic MCF-7 cells could effectively induce immature DC (iDC) maturation. The mean fluorescence intensity (MFI) of DC maturity marker CD83 was 23.3 in the ADM-induced apoptotic MCF-7 cell group compared with 8.5 in the MCF-7 cell group. The MFI of DC co-stimulatory marker CD86 and HLA-DR were also increased after iDCs were treated with ADM-induced apoptotic MCF-7 cells. Furthermore, the proliferating autologous T-lymphocytes increased from 14.2 to 40.3% after incubated with DCs induced by apoptotic MCF-7 cells. The secretion of interferon-γ by these T-lymphocytes was also increased. In addition, cell-cell interaction between apoptotic MCF-7 cells and iDCs, but not soluble factors released by apoptotic MCF-7 cells, was crucial for the maturation of iDCs. These findings constitute a novel in vitro DC-based vaccine strategy for the treatment of breast cancer by ADM-induced apoptotic MCF-7 cells.

  18. Co-culture of apoptotic breast cancer cells with immature dendritic cells: a novel approach for DC-based vaccination in breast cancer

    Directory of Open Access Journals (Sweden)

    Jin Zheng

    2012-06-01

    Full Text Available A dendritic cell (DC-based vaccine strategy could reduce the risk of recurrence and improve the survival of breast cancer patients. However, while therapy-induced apoptosis of hepatocellular and colorectal carcinoma cells can enhance maturation and antigen presentation of DCs, whether this effect occurs in breast cancer is currently unknown. In the present study, we investigated the effect of doxorubicin (ADM-induced apoptotic MCF-7 breast cancer cells on the activation of DCs. ADM-induced apoptotic MCF-7 cells could effectively induce immature DC (iDC maturation. The mean fluorescence intensity (MFI of DC maturity marker CD83 was 23.3 in the ADM-induced apoptotic MCF-7 cell group compared with 8.5 in the MCF-7 cell group. The MFI of DC co-stimulatory marker CD86 and HLA-DR were also increased after iDCs were treated with ADM-induced apoptotic MCF-7 cells. Furthermore, the proliferating autologous T-lymphocytes increased from 14.2 to 40.3% after incubated with DCs induced by apoptotic MCF-7 cells. The secretion of interferon-γ by these T-lymphocytes was also increased. In addition, cell-cell interaction between apoptotic MCF-7 cells and iDCs, but not soluble factors released by apoptotic MCF-7 cells, was crucial for the maturation of iDCs. These findings constitute a novel in vitro DC-based vaccine strategy for the treatment of breast cancer by ADM-induced apoptotic MCF-7 cells.

  19. AIRE is not essential for the induction of human tolerogenic dendritic cells.

    Science.gov (United States)

    Crossland, Katherine L; Abinun, Mario; Arkwright, Peter D; Cheetham, Timothy D; Pearce, Simon H; Hilkens, Catharien M U; Lilic, Desa

    2016-06-01

    Loss-of-function mutations of the Autoimmune Regulator (AIRE) gene results in organ-specific autoimmunity and disease Autoimmune Polyendocrinopathy type 1 (APS1)/Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED). The AIRE protein is crucial in the induction of central tolerance, promoting ectopic expression of tissue-specific antigens in medullary thymic epithelial cells and enabling removal of self-reactive T-cells. AIRE expression has recently been detected in myeloid dendritic cells (DC), suggesting AIRE may have a significant role in peripheral tolerance. DC stimulation of T-cells is critical in determining the initiation or lack of an immune response, depending on the pattern of costimulation and cytokine production by DCs, defining immunogenic/inflammatory (inflDC) and tolerogenic (tolDC) DC. In AIRE-deficient patients and healthy controls, we validated the role of AIRE in the generation and function of monocyte-derived inflDC and tolDCs by determining mRNA and protein expression of AIRE and comparing activation markers (HLA-DR/DP/DQ,CD83,CD86,CD274(PDL-1),TLR-2), cytokine production (IL-12p70,IL-10,IL-6,TNF-α,IFN-γ) and T-cell stimulatory capacity (mixed lymphocyte reaction) of AIRE+ and AIRE- DCs. We show for the first time that: (1) tolDCs from healthy individuals express AIRE; (2) AIRE expression is not significantly higher in tolDC compared to inflDC; (3) tolDC can be generated from APECED patient monocytes and (4) tolDCs lacking AIRE retain the same phenotype and reduced T-cell stimulatory function. Our findings suggest that AIRE does not have a role in the induction and function of monocyte-derived tolerogenic DC in humans, but these findings do not exclude a role for AIRE in peripheral tolerance mediated by other cell types.

  20. Analysis and Design of a Bidirectional Isolated DC-DC Converter for Fuel Cell and Super-Capacitor Hybrid System

    DEFF Research Database (Denmark)

    Zhang, Zhe; Ouyang, Ziwei; Thomsen, Ole Cornelius

    2012-01-01

    Electrical power system in future uninterruptible power supply (UPS) or electrical vehicle (EV) may employ hybrid energy sources, such as fuel cells and super-capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements...... for zero voltage switching (ZVS). Moreover, a phase-shift and duty cycle modulation method is utilized to control the bidirectional power flow flexibly and it also makes the converter operate under a quasi-optimal condition over a wide input voltage range. This paper describes the operation principle...

  1. High-risk human papilloma virus infection decreases the frequency of dendritic Langerhans' cells in the human female genital tract

    Science.gov (United States)

    Jimenez-Flores, Rafael; Mendez-Cruz, Rene; Ojeda-Ortiz, Jorge; Muñoz-Molina, Rebeca; Balderas-Carrillo, Oscar; de la Luz Diaz-Soberanes, Maria; Lebecque, Serge; Saeland, Sem; Daneri-Navarro, Adrian; Garcia-Carranca, Alejandro; Ullrich, Stephen E; Flores-Romo, Leopoldo

    2006-01-01

    Dendritic cells (DC) are often arranged in planar layers in tissues with high antigenic exposure, such as skin and mucosae. Providing an en face view, this arrangement optimizes in situ analysis regarding morphology (even of individual dendrites), topographic distribution (regular/clustered) and quantification. The few reports on human genital DC usually utilize single markers and conventional sections, restricting immunolabelling only to cell parts sectioned by the cut. To better assess DC in situ, we labelled epithelial sheets, prepared from fresh cervix biopsies, with antibodies to major histocompatibility complex (MHC)-CII, CD1a and Langerin, revealing (with each of these markers) a dense DC network in a planar-like, regular distribution. Using the hybrid capture system to detect the high-risk mucotropic human papilloma virus (HPV) group, 16 positive and five negative women were studied and the results were compared between these groups. DC frequency per area was substantially reduced (to ≈ 50% for the three markers) in samples from all HPV-infected patients compared with samples from controls. Unlike HPV– samples, Langerin+ DC in HPV+ cervix exhibited a highly accentuated dendritic appearance. We believe this to be the first study using these three DC-restricted markers (Langerin, CD1a and MHC-CII) in cervical epithelial sheets from high-risk HPV+ donors and also the first study to demonstrate the morphological and quantitative changes triggered by high-risk HPV infection. Cervical DC reduction in early, premalignant high-risk HPV infection might represent viral subversion strategies interfering with efficient antigen handling by the immune system's peripheral sentinels, the DC, perhaps hampering appropriate recruitment and subsequent development of effector (cytotoxic) T cells. PMID:16423058

  2. Natural IgM switches the function of LPS activated murine bone marrow dendritic cells (BMDC) to a “regulatory” DC that suppresses innate inflammation1

    OpenAIRE

    Lobo, Peter I.; Schlegel, Kailo H.; Bajwa, Amandeep; Huang, Liping; Kurmaeva, Elvira; Wang, Binru; Ye, Hong; Tedder, Thomas F.; Kinsey, Gilbert R.; Okusa, Mark D.

    2015-01-01

    We have previously shown that polyclonal natural IgM protects mice from renal IRI by inhibiting the reperfusion inflammatory response. We hypothesized that a potential mechanism involved IgM modulation of dendritic cells as we observed high IgM binding to splenic DC. To test this hypothesis, we pre-treated BMDC with polyclonal murine or human IgM prior to LPS activation and demonstrate that 0.5 × 106 IgM/LPS pretreated BMDC, when injected into WT-B6 mice, 24 hours before renal ischemia, prote...

  3. Mature dendritic cells derived from human monocytes within 48 hours: a novel strategy for dendritic cell differentiation from blood precursors.

    Science.gov (United States)

    Dauer, Marc; Obermaier, Bianca; Herten, Jan; Haerle, Carola; Pohl, Katrin; Rothenfusser, Simon; Schnurr, Max; Endres, Stefan; Eigler, Andreas

    2003-04-15

    It is widely believed that generation of mature dendritic cells (DCs) with full T cell stimulatory capacity from human monocytes in vitro requires 5-7 days of differentiation with GM-CSF and IL-4, followed by 2-3 days of activation. Here, we report a new strategy for differentiation and maturation of monocyte-derived DCs within only 48 h of in vitro culture. Monocytes acquire immature DC characteristics by day 2 of culture with GM-CSF and IL-4; they down-regulate CD14, increase dextran uptake, and respond to the inflammatory chemokine macrophage inflammatory protein-1alpha. To accelerate DC development and maturation, monocytes were incubated for 24 h with GM-CSF and IL-4, followed by activation with proinflammatory mediators for another 24 h (FastDC). FastDC expressed mature DC surface markers as well as chemokine receptor 7 and secreted IL-12 (p70) upon CD40 ligation in the presence of IFN-gamma. The increase in intracellular calcium in response to 6Ckine showed that chemokine receptor 7 expression was functional. When FastDC were compared with mature monocyte-derived DCs generated by a standard 7-day protocol, they were equally potent in inducing Ag-specific T cell proliferation and IFN-gamma production as well as in priming autologous naive T cells using tetanus toxoid as a model Ag. These findings indicate that FastDC are as effective as monocyte-derived DCs in stimulating primary, Ag-specific, Th 1-type immune responses. Generation of FastDC not only reduces labor, cost, and time required for in vitro DC development, but may also represent a model more closely resembling DC differentiation from monocytes in vivo.

  4. Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Stefania Bruno

    2016-01-01

    Full Text Available Human liver stem cells (HLSCs are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs, and dendritic cells (DCs in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2 and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs, HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

  5. Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation.

    Science.gov (United States)

    Bruno, Stefania; Grange, Cristina; Tapparo, Marta; Pasquino, Chiara; Romagnoli, Renato; Dametto, Ennia; Amoroso, Antonio; Tetta, Ciro; Camussi, Giovanni

    2016-01-01

    Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2) and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs), HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

  6. Energy Management Strategy Based on Multiple Operating States for a Photovoltaic/Fuel Cell/Energy Storage DC Microgrid

    Directory of Open Access Journals (Sweden)

    Ying Han

    2017-01-01

    Full Text Available It is a great challenge for DC microgrids with stochastic renewable sources and volatility loads to achieve better operation performance. This study proposes an energy management strategy based on multiple operating states for a DC microgrid, which is comprised of a photovoltaic (PV array, a proton exchange membrane fuel cell (PEMFC system, and a battery bank. This proposed strategy can share the power properly and keep the bus voltage steady under different operating states (the state of charge (SOC of the battery bank, loading conditions, and PV array output power. In addition, a microgrids test platform is established. In order to verify the effectiveness of the proposed energy management strategy, the strategy is implemented in a hardware system and experimentally tested under different operating states. The experimental results illustrate the good performance of the proposed control strategy for the DC microgrid under different scenarios of power generation and load demand.

  7. TLR4 and DC-SIGN receptors recognized Mycobacterium scrofulaceum promoting semi-activated phenotype on bone marrow dendritic cells.

    Science.gov (United States)

    Cruz-Aguilar, Marisa; Castillo-Rodal, Antonia I; Schcolnik-Cabrera, Alejandro; Bonifaz, Laura C; Molina, Gabriela; López-Vidal, Yolanda

    2016-07-01

    Nontuberculous mycobacteria (NTM) are recognized as emerging pathogens and their immune regulatory mechanisms are not well described yet. From them, Mycobacterium avium is known to be a weak activator of dendritic cells (DCs) that impairs the response induced by BCG vaccine. However, whether other NTM such as Mycobacterium scrofulaceum may modulate the activation of DCs, has not been extensively studied. Here, we exposed bone marrow-derived DCs (BMDCs) to M. scrofulaceum and we analyzed the effect on the activation of DCs. We found that M. scrofulaceum has a comparable ability to induce a semi-mature DC phenotype, which was produced by its interaction with DC-SIGN and TLR4 receptors in a synergic effect. BMDCs exposed to M. scrofulaceum showed high expression of PD-L2 and production of IL-10, as well as low levels of co-stimulatory molecules and pro-inflammatory cytokines. In addition to immunophenotype induced on DCs, changes in morphology, re-organization of cytoskeleton and decreased migratory capacity are consistent with a semi-mature phenotype. However, unlike other pathogenic mycobacteria, the DC-semi-mature phenotype induced by M. scrofulaceum was reversed after re-exposure to BCG, suggesting that modulation mechanisms of DC-activation used by M. scrofulaceum are different to other known pathogenic mycobacteria. This is the first report about the immunophenotypic characterization of DC stimulated by M. scrofulaceum.

  8. Quorum sensing in sourdough Lactobacillus plantarum DC400: induction of plantaricin A (PlnA) under co-cultivation with other lactic acid bacteria and effect of PlnA on bacterial and Caco-2 cells.

    Science.gov (United States)

    Di Cagno, Raffaella; De Angelis, Maria; Calasso, Maria; Vincentini, Olimpia; Vernocchi, Pamela; Ndagijimana, Maurice; De Vincenzi, Massimo; Dessì, Maria Rita; Guerzoni, Maria Elisabetta; Gobbetti, Marco

    2010-06-01

    This work aimed at showing the effect of pheromone plantaricin A (PlnA) by Lactobacillus plantarum DC400 towards other sourdough lactic acid bacteria and the potential of PlnA to protect the function of the human intestinal barrier. Growth and survival of sourdough lactic acid bacteria were differently affected by co-cultivation with L. plantarum DC400. Compared to mono-cultures, Lactobacillus sanfranciscensis DPPMA174 and Pediococcus pentosaceus 2XA3 showed growth inhibition and decreased viability when co-cultured with L. plantarum DC400. L. sanfranciscensis DPPMA174 induced the highest synthesis of PlnA. Survival of strain DPPMA174 only slightly varied by comparing the addition of PlnA to the culture medium and the co-cultivation with L. plantarum DC400. Compared to mono-culture, the proteome of L. sanfranciscensis DPPMA174 grown in co-culture with L. plantarum DC400 showed the variation of expression of 58 proteins (47 over expressed and 11 repressed). Thirty-four of them were also over expressed or repressed during growth of DPPMA174 with PlnA. Fifty-one of the above 58 proteins were identified. They had a central role in stress response, amino acid, energy and nucleotide metabolisms, membrane transport, regulation of transcription, and cell redox homeostasis. PlnA markedly increased the viability of human Caco-2/TC7 cells and the transepithelial electrical resistance.

  9. Natural killer (NK): dendritic cell (DC) cross talk induced by therapeutic monoclonal antibody triggers tumor antigen-specific T cell immunity.

    Science.gov (United States)

    Lee, Steve C; Srivastava, Raghvendra M; López-Albaitero, Andrés; Ferrone, Soldano; Ferris, Robert L

    2011-08-01

    Tumor antigen (TA)-targeted monoclonal antibodies (mAb), trastuzumab, cetuximab, panitumumab, and rituximab, have been among the most successful new therapies in the present generation. Clinical activity is observed as a single agent, or in combination with radiotherapy or chemotherapy, against metastatic colorectal cancer, head and neck cancer, breast cancer, and follicular lymphoma. However, the activity is seen only in a minority of patients. Thus, an intense need exists to define the mechanism of action of these immunoactive mAb. Here, we discuss some of the likely immunological events that occur in treated patients: antibody-dependent cellular cytotoxicity (ADCC), cross talk among immune cells including NK cells and dendritic cells (DCs), and generation of TA-specific T lymphocyte responses. We present evidence supporting the induction of "NK:DC cross talk," leading to priming of TA-specific cellular immunity. These observations show that mAb-mediated NK cell activation can be greatly enhanced by the action of stimulatory cytokines and surface molecules on maturing DC and that NK:DC interaction facilitates the recruitment of both NK cells and DC to the tumor site(s). The cooperative, reciprocal stimulatory activity of both NK cells and DC can modulate both the innate immune response in the local tumor microenvironment and the adaptive immune response in secondary lymphoid organs. These events likely contribute to clinical activity, as well as provide a potential biomarker of response to mAb therapy.

  10. The role of cDC1s in vivo: CD8 T cell priming through cross-presentation [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Derek Theisen

    2017-02-01

    Full Text Available The cDC1 subset of classical dendritic cells is specialized for priming CD8 T cell responses through the process of cross-presentation. The molecular mechanisms of cross-presentation remain incompletely understood because of limited biochemical analysis of rare cDC1 cells, difficulty in their genetic manipulation, and reliance on in vitro systems based on monocyte- and bone-marrow-derived dendritic cells. This review will discuss cross-presentation from the perspective of studies with monocyte- or bone-marrow-derived dendritic cells while highlighting the need for future work examining cDC1 cells. We then discuss the role of cDC1s as a cellular platform to combine antigen processing for class I and class II MHC presentation to allow the integration of “help” from CD4 T cells during priming of CD8 T cell responses.

  11. IL-10 conditioning of human skin affects the distribution of migratory dendritic cell subsets and functional T cell differentiation.

    Directory of Open Access Journals (Sweden)

    Jelle J Lindenberg

    Full Text Available In cancer patients pervasive systemic suppression of Dendritic Cell (DC differentiation and maturation can hinder vaccination efficacy. In this study we have extensively characterized migratory DC subsets from human skin and studied how their migration and T cell-stimulatory abilities were affected by conditioning of the dermal microenvironment through cancer-related suppressive cytokines. To assess effects in the context of a complex tissue structure, we made use of a near-physiological skin explant model. By 4-color flow cytometry, we identified migrated Langerhans Cells (LC and five dermis-derived DC populations in differential states of maturation. From a panel of known tumor-associated suppressive cytokines, IL-10 showed a unique ability to induce predominant migration of an immature CD14(+CD141(+DC-SIGN(+ DC subset with low levels of co-stimulatory molecules, up-regulated expression of the co-inhibitory molecule PD-L1 and the M2-associated macrophage marker CD163. A similarly immature subset composition was observed for DC migrating from explants taken from skin overlying breast tumors. Whereas predominant migration of mature CD1a(+ subsets was associated with release of IL-12p70, efficient Th cell expansion with a Th1 profile, and expansion of functional MART-1-specific CD8(+ T cells, migration of immature CD14(+ DDC was accompanied by increased release of IL-10, poor expansion of CD4(+ and CD8(+ T cells, and skewing of Th responses to favor coordinated FoxP3 and IL-10 expression and regulatory T cell differentiation and outgrowth. Thus, high levels of IL-10 impact the composition of skin-emigrated DC subsets and appear to favor migration of M2-like immature DC with functional qualities conducive to T cell tolerance.

  12. IL-10 conditioning of human skin affects the distribution of migratory dendritic cell subsets and functional T cell differentiation.

    Science.gov (United States)

    Lindenberg, Jelle J; Oosterhoff, Dinja; Sombroek, Claudia C; Lougheed, Sinéad M; Hooijberg, Erik; Stam, Anita G M; Santegoets, Saskia J A M; Tijssen, Henk J; Buter, Jan; Pinedo, Herbert M; van den Eertwegh, Alfons J M; Scheper, Rik J; Koenen, Hans J P M; van de Ven, Rieneke; de Gruijl, Tanja D

    2013-01-01

    In cancer patients pervasive systemic suppression of Dendritic Cell (DC) differentiation and maturation can hinder vaccination efficacy. In this study we have extensively characterized migratory DC subsets from human skin and studied how their migration and T cell-stimulatory abilities were affected by conditioning of the dermal microenvironment through cancer-related suppressive cytokines. To assess effects in the context of a complex tissue structure, we made use of a near-physiological skin explant model. By 4-color flow cytometry, we identified migrated Langerhans Cells (LC) and five dermis-derived DC populations in differential states of maturation. From a panel of known tumor-associated suppressive cytokines, IL-10 showed a unique ability to induce predominant migration of an immature CD14(+)CD141(+)DC-SIGN(+) DC subset with low levels of co-stimulatory molecules, up-regulated expression of the co-inhibitory molecule PD-L1 and the M2-associated macrophage marker CD163. A similarly immature subset composition was observed for DC migrating from explants taken from skin overlying breast tumors. Whereas predominant migration of mature CD1a(+) subsets was associated with release of IL-12p70, efficient Th cell expansion with a Th1 profile, and expansion of functional MART-1-specific CD8(+) T cells, migration of immature CD14(+) DDC was accompanied by increased release of IL-10, poor expansion of CD4(+) and CD8(+) T cells, and skewing of Th responses to favor coordinated FoxP3 and IL-10 expression and regulatory T cell differentiation and outgrowth. Thus, high levels of IL-10 impact the composition of skin-emigrated DC subsets and appear to favor migration of M2-like immature DC with functional qualities conducive to T cell tolerance.

  13. Mycobacterium tuberculosis infection induces non-apoptotic cell death of human dendritic cells

    LENUS (Irish Health Repository)

    Ryan, Ruth CM

    2011-10-24

    Abstract Background Dendritic cells (DCs) connect innate and adaptive immunity, and are necessary for an efficient CD4+ and CD8+ T cell response after infection with Mycobacterium tuberculosis (Mtb). We previously described the macrophage cell death response to Mtb infection. To investigate the effect of Mtb infection on human DC viability, we infected these phagocytes with different strains of Mtb and assessed viability, as well as DNA fragmentation and caspase activity. In parallel studies, we assessed the impact of infection on DC maturation, cytokine production and bacillary survival. Results Infection of DCs with live Mtb (H37Ra or H37Rv) led to cell death. This cell death proceeded in a caspase-independent manner, and without nuclear fragmentation. In fact, substrate assays demonstrated that Mtb H37Ra-induced cell death progressed without the activation of the executioner caspases, 3\\/7. Although the death pathway was triggered after infection, the DCs successfully underwent maturation and produced a host-protective cytokine profile. Finally, dying infected DCs were permissive for Mtb H37Ra growth. Conclusions Human DCs undergo cell death after infection with live Mtb, in a manner that does not involve executioner caspases, and results in no mycobactericidal effect. Nonetheless, the DC maturation and cytokine profile observed suggests that the infected cells can still contribute to TB immunity.

  14. Understanding MHC class I presentation of viral antigens by human dendritic cells as a basis for rational design of therapeutic vaccines.

    Science.gov (United States)

    van Montfoort, Nadine; van der Aa, Evelyn; Woltman, Andrea M

    2014-01-01

    Effective viral clearance requires the induction of virus-specific CD8(+) cytotoxic T lymphocytes (CTL). Since dendritic cells (DC) have a central role in initiating and shaping virus-specific CTL responses, it is important to understand how DC initiate virus-specific CTL responses. Some viruses can directly infect DC, which theoretically allow direct presentation of viral antigens to CTL, but many viruses target other cells than DC and thus the host depends on the cross-presentation of viral antigens by DC to activate virus-specific CTL. Research in mouse models has highly enhanced our understanding of the mechanisms underlying cross-presentation and the dendritic cells (DC) subsets involved, however, these results cannot be readily translated toward the role of human DC in MHC class I-antigen presentation of human viruses. Here, we summarize the insights gained in the past 20 years on MHC class I presentation of viral antigen by human DC and add to the current debate on the capacities of different human DC subsets herein. Furthermore, possible sources of viral antigens and essential DC characteristics for effective induction of virus-specific CTL are evaluated. We conclude that cross-presentation is not only an efficient mechanism exploited by DC to initiate immunity to viruses that do not infect DC but also to viruses that do infect DC, because cross-presentation has many conceptual advantages and bypasses direct immune modulatory effects of the virus on its infected target cells. Since knowledge on the mechanism of viral antigen presentation and the preferred DC subsets is crucial for rational vaccine design, the obtained insights are very instrumental for the development of effective anti-viral immunotherapy.

  15. Plasmacytoid dendritic cells suppress HIV-1 replication but contribute to HIV-1 induced immunopathogenesis in humanized mice.

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    Guangming Li

    2014-07-01

    Full Text Available The role of plasmacytoid dendritic cells (pDC in human immunodeficiency virus type 1 (HIV-1 infection and pathogenesis remains unclear. HIV-1 infection in the humanized mouse model leads to persistent HIV-1 infection and immunopathogenesis, including type I interferons (IFN-I induction, immune-activation and depletion of human leukocytes, including CD4 T cells. We developed a monoclonal antibody that specifically depletes human pDC in all lymphoid organs in humanized mice. When pDC were depleted prior to HIV-1 infection, the induction of IFN-I and interferon-stimulated genes (ISGs were abolished during acute HIV-1 infection with either a highly pathogenic CCR5/CXCR4-dual tropic HIV-1 or a standard CCR5-tropic HIV-1 isolate. Consistent with the anti-viral role of IFN-I, HIV-1 replication was significantly up-regulated in pDC-depleted mice. Interestingly, the cell death induced by the highly pathogenic HIV-1 isolate was severely reduced in pDC-depleted mice. During chronic HIV-1 infection, depletion of pDC also severely reduced the induction of IFN-I and ISGs, associated with elevated HIV-1 replication. Surprisingly, HIV-1 induced depletion of human immune cells including T cells in lymphoid organs, but not the blood, was reduced in spite of the increased viral replication. The increased cell number in lymphoid organs was associated with a reduced level of HIV-induced cell death in human leukocytes including CD4 T cells. We conclude that pDC play opposing roles in suppressing HIV-1 replication and in promoting HIV-1 induced immunopathogenesis. These findings suggest that pDC-depletion and IFN-I blockade will provide novel strategies for treating those HIV-1 immune non-responsive patients with persistent immune activation despite effective anti-retrovirus treatment.

  16. Complement regulates conventional DC-mediated NK-cell activation by inducing TGF-β1 in Gr-1+ myeloid cells.

    Science.gov (United States)

    Qing, Xiaoping; Koo, Gloria C; Salmon, Jane E

    2012-07-01

    Complement activation modulates DC-mediated T-cell activation, but whether complement affects DC-mediated priming of NK cells is unknown. Here, we demonstrated that conventional DCs (cDCs) from C3(-/-) and C5aR(-/-) mice are hyperresponsive to polyI:C, a TLR3 ligand, leading to enhanced NK-cell activation. We found that cDCs lack C5a receptor (C5aR) and do not respond to C5a directly. Depletion of Gr-1(+) myeloid cells augments polyI:C-induced cDC activation in WT but not in C3(-/-) or C5aR(-/-) mice, indicating that the effect of complement activation on cDCs is indirectly mediated through C5aR-expressing Gr-1(+) myeloid cells. We further demonstrated that the mechanism by which Gr-1(+) myeloid cells regulate the activity of cDCs involves C5a-dependent TGF-β1 production in Gr-1(+) myeloid cells. C5a enhances and blocking C5aR decreases TGF-β1 production in cultured bone marrow Gr-1(+) CD11b(+) cells. C5aR deficiency is associated with reduced circulating TGF-β1 levels, while depleting Gr-1(+) myeloid cells abrogates this difference between WT and C5aR(-/-) mice. Lastly, we showed that enhanced cDC-NK-cell activity in C3(-/-) mice led to delayed melanoma tumor growth. Thus, complement activation indirectly regulates cDC-NK-cell activation in response to inflammatory stimuli such as TLR3 by promoting TGF-β1 production in Gr-1(+) myeloid cells at steady state.

  17. Immature and maturation-resistant human dendritic cells generated from bone marrow require two stimulations to induce T cell anergy in vitro.

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    Thomas G Berger

    Full Text Available Immature dendritic cells (DC represent potential clinical tools for tolerogenic cellular immunotherapy in both transplantation and autoimmunity. A major drawback in vivo is their potential to mature during infections or inflammation, which would convert their tolerogenicity into immunogenicity. The generation of immature DC from human bone marrow (BM by low doses of GM-CSF (lowGM in the absence of IL-4 under GMP conditions create DC resistant to maturation, detected by surface marker expression and primary stimulation by allogeneic T cells. This resistence could not be observed for BM-derived DC generated with high doses of GM-CSF plus IL-4 (highGM/4, although both DC types induced primary allogeneic T cell anergy in vitro. The estabishment of the anergic state requires two subsequent stimulations by immature DC. Anergy induction was more profound with lowGM-DC due to their maturation resistance. Together, we show the generation of immature, maturation-resistant lowGM-DC for potential clinical use in transplant rejection and propose a two-step-model of T cell anergy induction by immature DC.

  18. Short-term effect of combined treatment ofDC-CIK cell and gamma knife in locally advanced hepatic carcinoma

    Institute of Scientific and Technical Information of China (English)

    Wei-Peng Zhang; Xi-Ming Xu; Wei Ge; Jian-Guo Wang; Yu-Xin Li; Jing-Jing Li; Shi-Yong Yang; Wei Liu

    2015-01-01

    Objective:To explore the clinical effect and significance of adoptive immunotherapy of dendritic cell and cytokine-induced killer cell (DC-CIK) combined with the gamma knife in the treatment of middle and advanced hepatic carcinoma.Methods:42 patients with the middle and advanced primary hepatic carcinoma were randomly divided into two groups: 20 cases in the combination group were given the adoptive immunotherapy of DC-CIK cells and gamma knife radiotherapy; 22 cases in the control group were only given the gamma knife radiotherapy. The short-term effect, quality of life, overall survival and toxic and side effects were compared between two groups after the operation.Results: 3 months after the treatment, the short-term effect of combination group and control group was 70% and 54.5% respectively (P<0.05). Patients in the combination group performed better in the overall survival, change of T-cell subsets, PS score, decrease rate of AFP and degree of liver function than the control group, while the adiodermatitis at II and over and bone marrow suppression were also better than the control group. Conclusion:The adoptive immunotherapy of DC-CIK cells combined with the gamma knife in the treatment of middle and advanced hepatic carcinoma can prolong the overall survival, improve the quality of life, reduce the toxic and side effect and effectively promote the short-term clinical effect for patients.

  19. The clinical effects of DC-CIK cells combined with chemotherapy in the treatment of advanced NSCLC%DC-CIK联合化疗治疗非小细胞肺癌的临床疗效评价

    Institute of Scientific and Technical Information of China (English)

    Junping Zhang; Jiangtao Wang; Tianliang Shi; Guanghua Mao; Yaping Han; Xiaoling Yang; Huijing Feng; Linzi Jia; Ting Zhi; Yan Xiao; Libin Zhang

    2012-01-01

    Objective: The aim of the study was to evaluate the safety and therapeutic effects of autologous dendritic cells co-cultured with cytokine-induced killer cells (DC-CIK) combined with chemotherapy in advanced non-small cell lung cancer (NSCLC) patients. Methods: Fifty patients with advanced NSCLC (stages III to IV), who had received therapies in our Center (Department of Biotherapy, Affiliated to Cancer Hospital of Shanxi Medical University, Taiyuan, China) from August 2008 to January 2010, were treated by DC-CIK + chemotherapy as the combined treatment group; fifty advanced NSCLC patients treated with chemotherapy at the same time served as controls. The immunologic function, short-term therapeutic effects, the 1-year survival rate, the life quality, the chemotherapy side effects were compared between the two groups, the safety and therapeutic effects of DC-CIK cells therapy were observed too. Results: There was no obvious change of subsets of T cells in peripheral blood before and after therapy in DC-CIK + chemotherapy group, and IFN-γ was improved after therapy in this group (P < 0.05); in chemotherapy alone group, the ratios of CD3+CD4+, CD3+CD8+, CD3-CD56+ cells and the secretion of IL-2, TNF-α decreased significantly after therapy (P < 0.05); the ratios of CD3+CD8+, CD3+CD56+ were improved after cell culture (P < 0.05). The disease control rate (DCR) of DC-CIK + chemotherapy group was higher than that in the chemotherapy alone group (78.0% vs 56.0%, P < 0.05); the 1-year survival rates of DC-CIK + chemotherapy group and chemotherapy alone group were 50% and 44% respectively, had no significant difference. Compared with chemotherapy alone group, the occurrence of chemotherapy side effects (including bone marrow suppression, nausea and vomiting, peripheral nerve toxicity) was less in the DC-CIK + chemotherapy group (P < 0.05). The physical and appetite were better in DC-CIK + chemotherapy group after therapy. Conclusion: To compare with simple chemotherapy, DC

  20. Fucose-based PAMPs prime dendritic cells for follicular T helper cell polarization via DC-SIGN-dependent IL-27 production.

    Science.gov (United States)

    Gringhuis, Sonja I; Kaptein, Tanja M; Wevers, Brigitte A; van der Vlist, Michiel; Klaver, Elsenoor J; van Die, Irma; Vriend, Lianne E M; de Jong, Marein A W P; Geijtenbeek, Teunis B H

    2014-10-03

    Dendritic cells (DCs) orchestrate antibody-mediated responses to combat extracellular pathogens including parasites by initiating T helper cell differentiation. Here we demonstrate that carbohydrate-specific signalling by DC-SIGN drives follicular T helper cell (TFH) differentiation via IL-27 expression. Fucose, but not mannose, engagement of DC-SIGN results in activation of IKKε, which collaborates with type I IFNR signalling to induce formation and activation of transcription factor ISGF3. Notably, ISGF3 induces expression of IL-27 subunit p28, and subsequent IL-27 secreted by DC-SIGN-primed DCs is pivotal for the induction of Bcl-6(+)CXCR5(+)PD-1(hi)Foxp1(lo) TFH cells, IL-21 secretion by TFH cells and T-cell-dependent IgG production by B cells. Thus, we have identified an essential role for DC-SIGN-induced ISGF3 by fucose-based PAMPs in driving IL-27 and subsequent TFH polarization, which might be harnessed for vaccination design.

  1. The activation of B cells enhances DC-SIGN expression and promotes susceptibility of B cells to HPAI H5N1 infection.

    Science.gov (United States)

    Na-Ek, Prasit; Thewsoongnoen, Jutarat; Thanunchai, Maytawan; Wiboon-Ut, Suwimon; Sa-Ard-Iam, Noppadol; Mahanonda, Rangsini; Thitithanyanont, Arunee

    2017-09-02

    The interplay between highly pathogenic avian influenza (HPAI) H5N1 virus and immune cells has been extensively studied for years, as host immune components are thought to play significant roles in promoting the systemic spread of the virus and responsible for cytokine storm. Previous studies suggested that the interaction of B cells and monocytes could promote HPAI H5N1 infection by enhancing avian influenza virus receptor expression. In this study, we further investigate the relationship between the HPAI H5N1 virus, activated B cells, and DC-SIGN expression. DC-SIGN has been described as an important factor for mediating various types of viral infection. Here, we first demonstrate that HPAI H5N1 infection could induce an activation of B cells, which was associated with DC-SIGN expression. Using CD40L and recombinant IL-4 for B cell stimulation, we determined that DC-SIGN expressed on activated B cells was able to enhance its susceptibility to HPAI H5N1 infection. Our findings uncover the interplay between this H5N1 virus and B cells and provide important information in understanding how the virus overcomes our immune system, contributing to its unusual immunopathogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Understanding MHC class I presentation of viral antigens by human dendritic cells as a basis for rational design of therapeutic vaccines

    Directory of Open Access Journals (Sweden)

    Nadine eVan Montfoort

    2014-04-01

    Full Text Available Effective viral clearance requires the induction of virus-specific CD8+ cytotoxic T lymphocytes (CTL. Since dendritic cells (DC have a central role in initiating and shaping virus-specific CTL responses, it is important to understand how DC initiate virus-specific CTL responses. Some viruses can directly infect DC, which theoretically allows direct presentation of viral antigens to CTL, but many viruses target other cells than DC and thus the host depends on the cross-presentation of viral antigens by DC to activate virus-specific CTL.Research in mouse models has highly enhanced our understanding of the mechanisms underlying cross-presentation and the DC subsets involved, however, these results cannot be readily translated towards the role of human DC in MHC class I antigen presentation of human viruses. Here, we summarize the insights gained in the past 20 years on MHC class I presentation of viral antigen by human DC and add to the current debate on the capacities of different human DC subsets herein. Furthermore, possible sources of viral antigens and essential DC characteristics for effective induction of virus-specific CTL are evaluated.We conclude that cross-presentation is not only an efficient mechanism exploited by DC to initiate immunity to viruses that do not infect DC but also to viruses that do infect DC, because cross-presentation has many conceptual advantages and bypasses direct immune modulatory effects of the virus on its infected target cells. Since knowledge on the mechanism of viral antigen presentation and the preferred DC subsets is crucial for rational vaccine design, the obtained insights are very instrumental for the development of effective anti-viral immunotherapy.

  3. Monomeric Immunoglobulin A from Plasma Inhibits Human Th17 Responses In Vitro Independent of FcαRI and DC-SIGN

    Science.gov (United States)

    Saha, Chaitrali; Das, Mrinmoy; Patil, Veerupaxagouda; Stephen-Victor, Emmanuel; Sharma, Meenu; Wymann, Sandra; Jordi, Monika; Vonarburg, Cédric; Kaveri, Srini V.; Bayry, Jagadeesh

    2017-01-01

    Circulating immunoglobulins including immunoglobulin G (IgG) and IgM play a critical role in the immune homeostasis by modulating functions of immune cells. These functions are mediated in part by natural antibodies. However, despite being second most abundant antibody in the circulation, the immunoregulatory function of IgA is relatively unexplored. As Th17 cells are the key mediators of a variety of autoimmune, inflammatory, and allergic diseases, we investigated the ability of monomeric IgA (mIgA) isolated from pooled plasma of healthy donors to modulate human Th17 cells. We show that mIgA inhibits differentiation and amplification of human Th17 cells and the production of their effector cytokine IL-17A. mIgA also suppresses IFN-γ responses under these experimental conditions. Suppressive effect of mIgA on Th17 responses is associated with reciprocal expansion of FoxP3-positive regulatory T cells. The effect of mIgA on Th17 cells is dependent on F(ab′)2 fragments and independent of FcαRI (CD89) and DC-SIGN. Mechanistically, the modulatory effect of mIgA on Th17 cells implicates suppression of phosphorylation of signal transducer and activator of transcription 3. Furthermore, mIgA binds to CD4+ T cells and recognizes in a dose-dependent manner the receptors for cytokines (IL-6Rα and IL-1RI) that mediate Th17 responses. Our findings thus reveal novel anti-inflammatory functions of IgA and suggest potential therapeutic utility of mIgA in autoimmune and inflammatory diseases that implicate Th17 cells. PMID:28352269

  4. Genome engineering in human cells.

    Science.gov (United States)

    Song, Minjung; Kim, Young-Hoon; Kim, Jin-Soo; Kim, Hyongbum

    2014-01-01

    Genome editing in human cells is of great value in research, medicine, and biotechnology. Programmable nucleases including zinc-finger nucleases, transcription activator-like effector nucleases, and RNA-guided engineered nucleases recognize a specific target sequence and make a double-strand break at that site, which can result in gene disruption, gene insertion, gene correction, or chromosomal rearrangements. The target sequence complexities of these programmable nucleases are higher than 3.2 mega base pairs, the size of the haploid human genome. Here, we briefly introduce the structure of the human genome and the characteristics of each programmable nuclease, and review their applications in human cells including pluripotent stem cells. In addition, we discuss various delivery methods for nucleases, programmable nickases, and enrichment of gene-edited human cells, all of which facilitate efficient and precise genome editing in human cells.

  5. In Vitro Generation of Human XCR1(+) Dendritic Cells from CD34(+) Hematopoietic Progenitors.

    Science.gov (United States)

    Balan, Sreekumar; Dalod, Marc

    2016-01-01

    Dendritic cells (DCs) are a heterogeneous population of professional antigen-presenting cells which play a key role in orchestrating immune defenses. Most of the information gained on human DC biology was derived from studies conducted with DCs generated in vitro from peripheral blood CD14(+) monocytes (MoDCs) or from CD34(+) hematopoietic progenitors. Recent advances in the field revealed that these types of in vitro-derived DCs strikingly differ from the DC subsets that are naturally present in human lymphoid organs, in terms of global gene expression, of specialization in the sensing of different types of danger signals, and of the ability to polarize T lymphocytes toward different functions. Major efforts are being made to better characterize the biology and the functions of lymphoid organ-resident DC subsets in humans, as an essential step for designing innovative DC-based vaccines against infections or cancers. However, this line of research is hampered by the low frequency of certain DC subsets in most tissues, their fragility, and the complexity of the procedures necessary for their purification. Hence, there is a need for robust procedures allowing large-scale in vitro generation of human DC subsets, under conditions allowing their genetic or pharmacological manipulation, to decipher their functions and their molecular regulation. Human CD141(+)CLEC9A(+)XCR1(+) DCs constitute a very interesting DC subset for the design of immunotherapeutic treatments against infections by intracellular pathogens or against cancer, because these cells resemble mouse professional cross-presenting CD8α(+)Clec9a(+)Xcr1(+) DCs. Human XCR1(+) DCs have indeed been reported by several teams to be more efficient than other human DC subsets for cross-presentation, in particular of cell-associated antigens but also of soluble antigens especially when delivered into late endosomes or lysosomes. However, human XCR1(+) DCs are the rarest and perhaps the most fragile of the human DC

  6. Highly efficient transduction of human plasmacytoid dendritic cells without phenotypic and functional maturation

    Directory of Open Access Journals (Sweden)

    Plumas Joel

    2009-01-01

    Full Text Available Abstract Background Gene modified dendritic cells (DC are able to modulate DC functions and induce therapeutic immunity or tolerance in an antigen-specific manner. Among the different DC subsets, plasmacytoid DC (pDC are well known for their ability to recognize and respond to a variety of viruses by secreting high levels of type I interferon. Methods We analyzed here, the transduction efficiency of a pDC cell line, GEN2.2, and of pDC derived from CD34+ progenitors, using lentiviral vectors (LV pseudotyped with different envelope glycoproteins such as the vesicular stomatitis virus envelope (VSVG, the gibbon ape leukaemia virus envelope (GaLV or the feline endogenous virus envelope (RD114. At the same time, we evaluated transgene expression (E-GFP reporter gene under the control of different promoters. Results We found that efficient gene transfer into pDC can be achieved with VSVG-pseudotyped lentiviral vectors (LV under the control of phoshoglycerate kinase (PGK and elongation factor-1 (EF1α promoters (28% to 90% of E-GFP+ cells, respectively in the absence of phenotypic and functional maturation. Surprisingly, promoters (desmin or synthetic C5–12 described as muscle-specific and which drive gene expression in single strand AAV vectors in gene therapy protocols were very highly active in pDC using VSVG-LV. Conclusion Taken together, our results indicate that LV vectors can serve to design pDC-based vaccines in humans, and they are also useful in vitro to evaluate the immunogenicity of the vector preparations, and the specificity and safety of given promoters used in gene therapy protocols.

  7. Epitope mapping on the dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN) pathogen-attachment factor.

    Science.gov (United States)

    Sierra-Filardi, Elena; Estecha, Ana; Samaniego, Rafael; Fernández-Ruiz, Elena; Colmenares, María; Sánchez-Mateos, Paloma; Steinman, Ralph M; Granelli-Piperno, Angela; Corbí, Angel L

    2010-01-01

    DC-SIGN (dendritic cell-specific ICAM-3-grabbing non-integrin) is a myeloid pathogen-attachment factor C-type lectin which recognizes mannose- and fucose-containing oligosaccharide ligands on clinically relevant pathogens. Intracellular signaling initiated upon ligand engagement of DC-SIGN interferes with TLR-initiated signals, and modulates the T cell activating and polarizing ability of antigen-presenting cells. The C-terminal carbohydrate-recognition domain (CRD) of DC-SIGN is preceded by a neck domain composed of eight 23-residue repeats which mediate molecule multimerization, and whose polymorphism correlates with altered susceptibility to SARS and HIV infection. Naturally occurring isoforms and chimaeric molecules, in combination with established recognition properties, were used to define seven structural and functional epitopes on DC-SIGN. Three epitopes mapped to the CRD, one of which is multimerization-dependent and only exposed on DC-SIGN monomers. Epitopes within the neck domain were conformation-independent and unaltered upon molecule multimerization, but were differentially affected by neck domain truncations. Although neck-specific antibodies exhibited lower function-blocking ability, they were more efficient at inducing molecule internalization. Moreover, crosslinking of the different epitopes resulted in distinct levels of microclustering on the cell surface. The identification of independent epitopes on the DC-SIGN molecule might facilitate the design of reagents that modulate the T cell activating and polarizing ability of DC-SIGN-expressing cells without preventing its antigen- and pathogen-recognition capacities.

  8. In-Vitro differentiation of mature dendritic cells from human blood monocytes

    OpenAIRE

    Robert Gieseler; Dirk Heise; Afsaneh Soruri; Peter Schwartz; J. Hinrich Peters

    1998-01-01

    Representing the most potent antigen-presenting cells, dendritic cells (DC) can now be generated from human blood monocytes. We recently presented a novel protocol employing GM-CSF, IL-4, and IFN-γ to differentiate monocyte-derived DC in vitro. Here, such cells are characterized in detail. Cells in culture exhibited both dendritic and veiled morphologies, the former being adherent and the latter suspended. Phenotypically, they were CD1a-/dim, CD11a+, CD11b++, CD11c+, CD14dim/-, CD16a-/dim, CD...

  9. Class 3 semaphorins induce F-actin reorganization in human dendritic cells: Role in cell migration.

    Science.gov (United States)

    Curreli, Sabrina; Wong, Bin Sheng; Latinovic, Olga; Konstantopoulos, Konstantinos; Stamatos, Nicholas M

    2016-12-01

    Class 3 semaphorins (Semas) are soluble proteins that are well recognized for their role in guiding axonal migration during neuronal development. In the immune system, Sema3A has been shown to influence murine dendritic cell (DC) migration by signaling through a neuropilin (NRP)-1/plexin-A1 coreceptor axis. Potential roles for class 3 Semas in human DCs have yet to be described. We tested the hypothesis that Sema3A, -3C, and -3F, each with a unique NRP-1 and/or NRP-2 binding specificity, influence human DC migration. In this report, we find that although NRP-1 and NRP-2 are expressed in human immature DCs (imDCs), NRP-2 expression increases as cells mature further, whereas expression of NRP-1 declines dramatically. Elevated levels of RNA encoding plexin-A1 and -A3 are present in both imDCs and mature DC (mDCs), supporting the relevance of Sema/NRP/plexin signaling pathways in these cells. Sema3A, -3C, and -3F bind to human DCs, with Sema3F binding predominantly through NRP-2. The binding of these Semas leads to reorganization of actin filaments at the plasma membrane and increased transwell migration in the absence or presence of chemokine CCL19. Microfluidic chamber assays failed to demonstrate consistent changes in speed of Sema3C-treated DCs, suggesting increased cell deformability as a possible explanation for enhanced transwell migration. Although monocytes express RNA encoding Sema3A, -3C, and -3F, only RNA encoding Sema3C increases robustly during DC differentiation. These data suggest that Sema3A, -3C, and -3F, likely with coreceptors NRP-1, NRP-2, and plexin-A1 and/or -A3, promote migration and possibly other activities of human DCs during innate and adaptive immune responses.

  10. Cu2ZnSnS4 solar cells prepared with sulphurized dc-sputtered stacked metallic precursors

    OpenAIRE

    Fernandes, P. A.; Salomé, P M P; Cunha, A. F. da; Schubert, Björn-Arvid

    2010-01-01

    In the present work we report the details of the preparation and characterization results of Cu2ZnSnS4 (CZTS) based solar cells. The CZTS absorber was obtained by sulphurization of dc magnetron sputtered Zn/Sn/Cu precursor layers. The morphology, composition and structure of the absorber layer were studied by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and Raman scattering. The majority carrier type was identified via a hot point probe analysis....

  11. The Preparation for Human B7-2 and DC Vaccines and their Roles in Anti-tumor Immunity Against Esophageal CancerIn Vitro

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionB7-2 molecule is the initial co-stimulatory ligand expressed on APC by its abundant,early and easily induced expression pattern, which so is known as its important role at the initial stage of the immune response. Some tumor cells can not express B7-2 or its expression is low, which leads to tumor's immune escape. Dendritic cells(DC) is the most powerful professional antigen presenting cells(APC), and can activate naive or resting T cells. The cellular immunity response activated by DC plays a...

  12. Anti-proliferative effects of Atractylis lancea (Thunb.) DC. via down-regulation of the c-myc/hTERT/telomerase pathway in Hep-G2 cells.

    Science.gov (United States)

    Guo, Wei-Qiang; Li, Liang-Zhi; He, Zhuo-Yang; Zhang, Qi; Liu, Jia; Hu, Cui-Ying; Qin, Fen-Ju; Wang, Tao-Yun

    2013-01-01

    Atractylis lancea (Thunb.) DC. (AL), an important medicinal herb in Asia, has been shown to have anti-tumor effects on cancer cells, but the involved mechanisms are poorly understood. This study focused on potential effects and molecular mechanisms of AL on the proliferation of the Hep-G2 liver cancer cell line in vitro. Cell viability was assessed by MTT test in Hep-G2 cells incubated with an ethanol extract of AL. Then, the effects of AL on apoptosis and cell cycle progression were determined by flow cytometry. Telomeric repeat amplification protocol (TRAP) assays was performed to investigate telomerase activity. The mRNA and protein expression of human telomerase reverse transcriptase (hTERT) and c-myc were determined by real-time RT-PCR and Western blotting. Our results show that AL effectively inhibits proliferation in Hep-G2 cells in a concentration- and time-dependent manner. When Hep-G2 cells were treated with AL after 48h,the IC50 was about 72.1 μg/ mL. Apoptosis was induced by AL via arresting the cells in the G1 phase. Furthermore, AL effectively reduced telomerase activity through inhibition of mRNA and protein expression of hTERT and c-myc. Hence, these data demonstrate that AL exerts anti-proliferative effects in Hep-G2 cells via down-regulation of the c-myc/hTERT/ telomerase pathway.

  13. Helicobacter pylori modulates the T helper cell 1/T helper cell 2 balance through phase-variable interaction between lipopolysaccharide and DC-SIGN.

    NARCIS (Netherlands)

    Bergman, M.P.; Engering, A.J.; Smits, HH; Vliet, van SJ; Bodegraven, van A.A.; Wirth, HP; Kapsenberg, ML; Vandenbroucke-Grauls, C.M.J.E.; Kooijk, van Y.; Appelmelk, B.J.

    2004-01-01

    The human gastric pathogen Helicobacter pylori spontaneously switches lipopolysaccharide (LPS) Lewis (Le) antigens on and off (phase-variable expression), but the biological significance of this is unclear. Here, we report that Le+ H. pylori variants are able to bind to the C-type lectin DC-SIGN and

  14. Human monocytes undergo functional re-programming during differentiation to dendritic cell mediated by human extravillous trophoblasts

    Science.gov (United States)

    Zhao, Lei; Shao, Qianqian; Zhang, Yun; Zhang, Lin; He, Ying; Wang, Lijie; Kong, Beihua; Qu, Xun

    2016-01-01

    Maternal immune adaptation is required for a successful pregnancy to avoid rejection of the fetal–placental unit. Dendritic cells within the decidual microenvironment lock in a tolerogenic profile. However, how these tolerogenic DCs are induced and the underlying mechanisms are largely unknown. In this study, we show that human extravillous trophoblasts redirect the monocyte-to-DC transition and induce regulatory dendritic cells. DCs differentiated from blood monocytes in the presence of human extravillous trophoblast cell line HTR-8/SVneo displayed a DC-SIGN+CD14+CD1a− phenotype, similar with decidual DCs. HTR8-conditioned DCs were unable to develop a fully mature phenotype in response to LPS, and altered the cytokine secretory profile significantly. Functionally, conditioned DCs poorly induced the proliferation and activation of allogeneic T cells, whereas promoted CD4+CD25+Foxp3+ Treg cells generation. Furthermore, the supernatant from DC and HTR-8/SVneo coculture system contained significant high amount of M-CSF and MCP-1. Using neutralizing antibodies, we discussed the role of M-CSF and MCP-1 during monocyte-to-DCs differentiation mediated by extravillous trophoblasts. Our data indicate that human extravillous trophoblasts play an important role in modulating the monocyte-to-DC differentiation through M-CSF and MCP-1, which facilitate the establishment of a tolerogenic microenvironment at the maternal–fetal interface. PMID:26857012

  15. TAP-deficient human iPS cell-derived myeloid cell lines as unlimited cell source for dendritic cell-like antigen-presenting cells.

    Science.gov (United States)

    Haruta, M; Tomita, Y; Yuno, A; Matsumura, K; Ikeda, T; Takamatsu, K; Haga, E; Koba, C; Nishimura, Y; Senju, S

    2013-05-01

    We previously reported a method to generate dendritic cell (DC)-like antigen-presenting cells (APC) from human induced pluripotent stem (iPS) cells. However, the method is relatively complicated and laborious. In the current study, we attempted to establish a method through which we could obtain a large number of functional APC with a simple procedure. We transduced iPS cell-derived CD11b(+) myeloid cells with genes associated with proliferative or anti-senescence effects, enabling the cells to propagate for more than 4 months in a macrophage colony-stimulating factor (M-CSF)-dependent manner while retaining their capacity to differentiate into functional APC. We named these iPS cell-derived proliferating myeloid cells 'iPS-ML', and the iPS-ML-derived APC 'ML-DC'. In addition, we generated TAP2-deficient iPS cell clones by zinc finger nuclease-aided targeted gene disruption. TAP2-deficient iPS cells and iPS-ML avoided recognition by pre-activated allo-reactive CD8(+) T cells. TAP2-deficient ML-DC expressing exogenously introduced HLA-A2 genes stimulated HLA-A2-restricted MART-1-specific CD8(+) T cells obtained from HLA-A2-positive allogeneic donors, resulting in generation of MART-1-specific cytotoxic T lymphocyte (CTL) lines. TAP-deficient iPS-ML introduced with various HLA class I genes may serve as an unlimited source of APC for vaccination therapy. If administered into allogeneic patients, ML-DC with appropriate genetic modifications may survive long enough to stimulate antigen-specific CTL and, after that, be completely eliminated. Based on the present study, we propose an APC-producing system that is simple, safe and applicable to all patients irrespective of their HLA types.

  16. Clinical efficacy of sunitinib combined with autologous DC and CIK for patients with metastatic renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Liang ZHANG

    2014-01-01

    Full Text Available Objective To analyze the clinical efficacy and safety of sunitinib combined with autologous dentritic cell (DC and cytokine induced killer cell (CIK for patients suffering from metastatic renal cell carcinoma (mRCC. Methods Clinical data of 27 mRCC patients treated with sunitinib combined with autologous DC and CIK were reviewed retrospectively. Efficacy, quality of life, immunology and safety of this treatment were evaluated. Results Follow-up time ranged from 4 to 25 months. Out of all the patients, sunitinib was reduced in 1 and discontinued in 2 due to side effects; 1 patient quit for personal reasons; 14 patients developed progressive disease. The progression-free survival (PFS was 4 to 19.5 months. Ten patients died from tumor, the overall survival time (OS was 6 to 21 months. The median PFS was 16 months (95%CI 12.5-19.5. The OS was not achieved. The efficacy was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST. All the patients received treatment over 1 cycle. After one course of treatment, among 27 patients, 0 had complete remission (CR, 4 had partial remission (PR, 17 had stable disease (SD, and 6 had progressive disease (PD. The overall objective remission rate (ORR and disease control rate (DCR were 14.8% (4/27 and 77.8% (21/27, respectively. Sunitinib and autologous transfusion of DC and CIK improved the immune function and quality of life. The major adverse events were fatigue, hand-foot syndrome, hypertension, hypothyroidism, thrombocytopenia, neutropenia and fever. Most of the adverse events were ameliorated by supportive treatment or dose reduction. Conclusions  Sunitinib combined with autologous DC and CIK may be beneficial in the treatment of mRCC with acceptable toxic reactions, and it may be considered as a new approach for the comprehensive treatment of RCC. DOI: 10.11855/j.issn.0577-7402.2013.12.06

  17. Human gut dendritic cells drive aberrant gut-specific t-cell responses in ulcerative colitis, characterized by increased IL-4 production and loss of IL-22 and IFNγ.

    Science.gov (United States)

    Mann, Elizabeth R; Bernardo, David; Ng, Siew C; Rigby, Rachael J; Al-Hassi, Hafid O; Landy, Jon; Peake, Simon T C; Spranger, Henning; English, Nicholas R; Thomas, Linda V; Stagg, Andrew J; Knight, Stella C; Hart, Ailsa L

    2014-12-01

    : The pathogenesis of inflammatory bowel disease is incompletely understood but results from a dysregulated intestinal immune response to the luminal microbiota. CD4 T cells mediate tissue injury in the inflammatory bowel disease-associated immune response. Dendritic cells (DC) generate primary T-cell responses and mediate intestinal immune tolerance to prevent overt inflammation in response to the gut microbiota. However, most information regarding function of intestinal DC has come from mouse models, and information in humans is scarce. We show here that intestinal DC subsets are skewed in ulcerative colitis (UC) in humans, with a loss of CD103 lymph-node homing DC; this intestinal DC subset preferentially generates regulatory T cells in mice. We show infiltrates of DC negative for myeloid marker CD11c, with enhanced expression of Toll-like receptors for bacterial recognition. After mixed leukocyte reaction, DC from the inflamed UC colon had an enhanced ability to generate gut-specific CD4 T cells with enhanced production of interleukin-4 but a loss of interferon γ and interleukin-22 production. Conditioning intestinal DC with probiotic strain Lactobacillus casei Shirota in UC partially restored their normal function indicated by reduced Toll-like receptor 2/4 expression and restoration of their ability to imprint homing molecules on T cells and to generate interleukin-22 production by stimulated T cells. This study suggests that T-cell dysfunction in UC is driven by DC. T-cell responses can be manipulated indirectly through effects of bacterial conditioning on gut DC with implications for immunomodulatory effects of the commensal microbiota in vivo. Manipulation of DC to allow generation of DC-specific therapy may be beneficial in inflammatory bowel disease.

  18. Antigen-specific IL-23/17 pathway activation by murine semi-mature DC-like cells

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaka, Shinya; Iwasaki, Takumi; Okano, Tomoko [Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510 (Japan); Chiba, Joe, E-mail: chibaj@rs.noda.tus.ac.jp [Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510 (Japan)

    2009-09-11

    We analyzed the phenotype and function of bone marrow-derived dendritic cells (DCs) induced in vitro without using any serum during the late stage of cultivation. These 'serum-free' DCs (SF-DCs) possessed the ability to induce T cell proliferation as well as antibody responses, indicating that they were functional DCs. Surprisingly, the SF-DCs akin to semi-mature DCs in terms of both phenotypic and functional characteristics. The SF-DCs did not produce IL-12 but produced large amounts of IL-23 following lipopolysaccharide stimulation. The antigen-specific production of IL-17 by CD4{sup +} T cells co-cultured with OVA-loaded SF-DCs was significantly higher than that with OVA-loaded conventional DCs. These results suggest that SF-DCs tend to produce IL-23 and can consequently induce the IL-17 producing CD4{sup +} T cells. The semi-mature DC-like cells reported here will be useful vehicles for DC immunization and might contribute to studies on the possible involvement of semi-mature DCs in Th17 cell differentiation.

  19. MODELLING AND SIMULATION OF TWO-LEVEL SPACE VECTOR PWM INVERTER USING PHOTOVOLTAIC CELLS AS DC SOURCE

    Directory of Open Access Journals (Sweden)

    Ayse KOCALMIS BILHAN

    2013-01-01

    Full Text Available A space vector PWM method for a two level inverter is proposed in this paper. A two level inverter using space vector modulation strategy has been modeled and simulated with a passive R-L load. Photovoltaic cells are used as DC source for input of two-level inverter. Simulation results are presented for various operation conditions to verify the system model. In this paper, MATLAB/Simulink package program has been used for modeling and simulation of PV cells and two-level space vector pulse width modulation (SVPWM inverter.

  20. Mechanistic studies of flux variability of neutral and ionic permeants during constant current dc iontophoresis with human epidermal membrane.

    Science.gov (United States)

    Li, S Kevin; Higuchi, William I; Kochambilli, Rajan P; Zhu, Honggang

    2004-04-01

    Although constant current iontophoresis is supposed to provide constant transdermal transport, significant flux variability and/or time-dependent flux drifts are observed during iontophoresis with human skin in vitro and human studies in vivo. The objectives of the present study were to determine (a) the causes of flux variability in constant current dc transdermal iontophoresis and (b) the relationships of flux variabilities among permeants of different physicochemical properties. Changes in the human epidermal membrane (HEM) effective pore size and/or electroosmosis during constant current dc iontophoresis were examined. Tetraethylammonium ion (TEA), urea, and mannitol were the model permeants. For the neutral permeants, the results in the present study showed a significant increase of fluxes with time in a given experiment and large HEM sample-to-sample variability. Although both effective pore size and pore charge density variations contributed to the time-dependent flux drifts observed in electroosmotic transport, the significant flux drifts observed were found to be primarily a result of the time-dependent increase in effective pore charge density. For the ionic permeant, the observed flux variability was smaller than that of the neutral permeants and was believed to be primarily due to effective pore size alteration in HEM during iontophoresis as suggested in a previous study. The different extents of flux variability observed between neutral and ionic permeants are consistent with the different iontophoretically enhanced transport mechanisms for the neutral and ionic permeants (i.e. electroosmosis and electrophoresis, respectively). The results of the present study also demonstrate that flux variability of two neutral permeants are inter-related, so the flux of one neutral permeant can be predicted if the permeability coefficient of the other neutral permeant is known.

  1. Cross-Presentation in Mouse and Human Dendritic Cells.

    Science.gov (United States)

    Segura, Elodie; Amigorena, Sebastian

    2015-01-01

    Cross-presentation designates the presentation of exogenous antigens on major histocompatibility complex class I molecules and is essential for the initiation of cytotoxic immune responses. It is now well established that dendritic cells (DCs) are the best cross-presenting cells. In this chapter, we will discuss recent advances in our understanding of the molecular mechanisms of cross-presentation. We will also describe the different DC subsets identified in mouse and human, and their functional specialization for cross-presentation. Finally, we will summarize the current knowledge of the role of cross-presentation in pathological situations.

  2. Formation of bipolar spindles with two centrosomes in tetraploid cells established from normal human fibroblasts.

    Science.gov (United States)

    Ohshima, Susumu; Seyama, Atsushi

    2012-09-01

    Tetraploid cells with unstable chromosomes frequently arise as an early step in tumorigenesis and lead to the formation of aneuploid cells. The mechanisms responsible for the chromosome instability of polyploid cells are not fully understood, although the supernumerary centrosomes in polyploid cells have been considered the major cause of chromosomal instability. The aim of this study was to examine the integrity of mitotic spindles and centrosomes in proliferative polyploid cells established from normal human fibroblasts. TIG-1 human fibroblasts were treated with demecolcine (DC) for 4 days to induce polyploidy, and the change in DNA content was monitored. Localization of centrosomes and mitotic spindles in polyploid mitotic cells was examined by immunohistochemistry and laser scanning cytometry. TIG-1 cells treated with DC became almost completely tetraploid at 2 weeks after treatment and grew at the same rate as untreated diploid cells. Most mitotic cells with 8C DNA content had only two centrosomes with bipolar spindles in established tetraploid cells, although they had four or more centrosomes with multipolar spindles at 3 days after DC treatment. The frequency of aneuploid cells increased as established tetraploid cells were propagated. These results indicate that tetraploid cells that form bipolar spindles with two centrosomes in mitosis can proliferate as diploid cells. These cells may serve as a useful model for studying the chromosome instability of polyploid cells.

  3. Advanced DC/DC converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    INTRODUCTIONHistorical ReviewMultiple Quadrant ChoppersPump CircuitsDevelopment of DC/DC Conversion TechniqueCategorize Prototypes and DC/DC Converters Family TreeVOLTAGE-LIFT CONVERTERSIntroductionSeven Self-Lift ConvertersPositive Output Luo-ConvertersNegative Output Luo-ConvertersModified Positive Output Luo-Converters Double Output Luo-ConvertersPOSITIVE OUTPUT SUPER-LIFT LUO-CONVERTERS IntroductionMain SeriesAdditional SeriesEnhanced Series Re-Enhanced Series Multiple-Enhanced Series Summary of Positive Output

  4. Assessment of serum tumor markers, tumor cell apoptosis and immune response in patients with advanced colon cancer after DC-CIK combined with intravenous chemotherapy

    Institute of Scientific and Technical Information of China (English)

    Lei-Fan Li; Xiu-Yun Wang; Hui-Qiong Xu; Xia Liu

    2016-01-01

    Objective:To study the effect of DC-CIK combined with intravenous chemotherapy on serum tumor markers, tumor cell apoptosis and immune response in patients with advanced colon cancer.Methods:A total of 79 patients with advanced colon cancer conservatively treated in our hospital between May 2012 and October 2015 were retrospectively studied and divided into DC-CIK group and intravenous chemotherapy group according to different therapeutic regimens, DC-CIK group received DC-CIK combined with intravenous chemotherapy and intravenous chemotherapy group received conventional intravenous chemotherapy. After three cycles of chemotherapy, the content of tumor markers in serum, expression levels of apoptotic molecules in tumor lesions as well as immune function indexes were determined.Results:After 3 cycles of chemotherapy, CEA, CA199, CA242, HIF-1α, IL-4, IL-5 and IL-10 content in serum of DC-CIK group were significantly lower than those of intravenous chemotherapy group;p53, FAM96B, PTEN, PHLPP, ASPP2and RASSF10 mRNA content in tumor lesions of DC-CIK group were significantly higher than those of intravenous chemotherapy group; the fluorescence intensity of CD3, CD4 and CD56 on peripheral blood mononuclear cell surface of DC-CIK group were significantly higher than those of intravenous chemotherapy group while the fluorescence intensity of CD8 and CD25 were significantly lower than those of intravenous chemotherapy group; IL-2 and IFN-γ content in serum of DC-CIK group were significantly higher than those of intravenous chemotherapy group while IL-4, IL-5 and IL-10 content were significantly lower than those of intravenous chemotherapy group.Conclusions: DC-CIK combined with intravenous chemotherapy has better effect on killing colon cancer cells and inducing colon cancer cell apoptosis than conventional intravenous chemotherapy, and can also improve the body's anti-tumor immune response.

  5. DC + RSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne

    1996-01-01

    This document gives some initial ideas of how the Duration Calculus (DC) can be integrated with the RAISE Specification Language (RSL).......This document gives some initial ideas of how the Duration Calculus (DC) can be integrated with the RAISE Specification Language (RSL)....

  6. Diffusion inside living human cells

    DEFF Research Database (Denmark)

    Leijnse, N.; Jeon, J. -H.; Loft, Steffen

    2012-01-01

    Naturally occurring lipid granules diffuse in the cytoplasm and can be used as tracers to map out the viscoelastic landscape inside living cells. Using optical trapping and single particle tracking we found that lipid granules exhibit anomalous diffusion inside human umbilical vein endothelial...... cells. For these cells the exact diffusional pattern of a particular granule depends on the physiological state of the cell and on the localization of the granule within the cytoplasm. Granules located close to the actin rich periphery of the cell move less than those located towards to the center...... of the cell or within the nucleus. Also, granules in cells which are stressed by intense laser illumination or which have attached to a surface for a long period of time move in a more restricted fashion than those within healthy cells. For granules diffusing in healthy cells, in regions away from the cell...

  7. Clinical Tolerogenic Dendritic Cells: Exploring Therapeutic Impact on Human Autoimmune Disease

    Directory of Open Access Journals (Sweden)

    Brett Eugene Phillips

    2017-10-01

    Full Text Available Tolerogenic dendritic cell (tDC-based clinical trials for the treatment of autoimmune diseases are now a reality. Clinical trials are currently exploring the effectiveness of tDC to treat autoimmune diseases of type 1 diabetes mellitus, rheumatoid arthritis, multiple sclerosis (MS, and Crohn’s disease. This review will address tDC employed in current clinical trials, focusing on cell characteristics, mechanisms of action, and clinical findings. To date, the publicly reported human trials using tDC indicate that regulatory lymphocytes (largely Foxp3+ T-regulatory cell and, in one trial, B-regulatory cells are, for the most part, increased in frequency in the circulation. Other than this observation, there are significant differences in the major phenotypes of the tDC. These differences may affect the outcome in efficacy of recently launched and impending phase II trials. Recent efforts to establish a catalog listing where tDC converge and diverge in phenotype and functional outcome are an important first step toward understanding core mechanisms of action and critical “musts” for tDC to be therapeutically successful. In our view, the most critical parameter to efficacy is in vivo stability of the tolerogenic activity over phenotype. As such, methods that generate tDC that can induce and stably maintain immune hyporesponsiveness to allo- or disease-specific autoantigens in the presence of powerful pro-inflammatory signals are those that will fare better in primary endpoints in phase II clinical trials (e.g., disease improvement, preservation of autoimmunity-targeted tissue, allograft survival. We propose that pre-treatment phenotypes of tDC in the absence of functional stability are of secondary value especially as such phenotypes can dramatically change following administration, especially under dynamic changes in the inflammatory state of the patient. Furthermore, understanding the outcomes of different methods of cell delivery and sites

  8. Intestinal colonization of IL-2 deficient mice with non-colitogenic B. vulgatus prevents DC maturation and T-cell polarization.

    Directory of Open Access Journals (Sweden)

    Martina Müller

    Full Text Available BACKGROUND: IL-2 deficient (IL-2(-/- mice mono-colonized with E. coli mpk develop colitis whereas IL-2(-/--mice mono-colonized with B. vulgatus mpk do not and are even protected from E. coli mpk induced colitis. METHODOLOGY/PRINCIPAL FINDINGS: We investigated if mono-colonization with E. coli mpk or B. vulgatus mpk differentially modulates distribution, activation and maturation of intestinal lamina propria (LP dendritic cells (DC. LP DC in mice mono-colonized with protective B. vulgatus mpk or co-colonized with E. coli mpk/B. vulgatus mpk featured a semi-mature LP DC phenotype (CD40(loCD80(loMHC-II(hi whereas mono-colonization with colitogenic E. coli mpk induced LP DC activation and maturation prior to onset of colitis. Accordingly, chemokine receptor (CCR 7 surface expression was more strikingly enhanced in mesenteric lymph node DC from E. coli mpk than B. vulgatus mpk mono- or co-colonized mice. Mature but not semi-mature LP DC promoted Th1 polarization. As B. vulgatus mpk promotes differentiation of semi-mature DC presumably by IL-6, mRNA and protein expression of IL-6 was investigated in LP DC. The data demonstrated that IL-6 mRNA and protein was increased in LP DC of B. vulgatus mpk as compared to E. coli mpk mono-colonized IL-2(-/--mice. The B. vulgatus mpk mediated suppression of CCR7 expression and DC migration was abolished in IL-6(-/--DC in vitro. CONCLUSIONS/SIGNIFICANCE: From this data we conclude that the B. vulgatus triggered IL-6 secretion by LP DC in absence of proinflammatory cytokines such as IL-12 or TNF-alpha induces a semi-mature LP DC phenotype, which might prevent T-cell activation and thereby the induction of colitis in IL-2(-/--mice. The data provide new evidence that IL-6 might act as an immune regulatory cytokine in the mucosa by targeting intestinal DC.

  9. Preferential production of the IL-12(p40)/IL-23(p19) heterodimer by dendritic cells from human newborns.

    Science.gov (United States)

    Vanden Eijnden, Serge; Goriely, Stanislas; De Wit, Dominique; Goldman, Michel; Willems, Fabienne

    2006-01-01

    Human newborns present impaired T helper type 1 cell responses, associated with a defect in the synthesis of IL-12 by dendritic cells (DC). IL-23 is a heterodimeric cytokine structurally related to IL-12, implicated in protective and autoimmune responses. We recently showed that upon activation neonatal T cells up-regulate a functional IL-23 receptor and that this cytokine polarizes the differentiation of naive T cells. We therefore investigated the capacity of neonatal DC to secrete IL-23. Lipopolysaccharide (LPS) stimulation induced the transcription of IL-23(p19) mRNA in both adult and neonatal DC, in sharp contrast to the repressed IL-12(p35) gene expression observed in neonatal cells. In comparison to adult DC, neonatal DC produced similar levels of IL-23 protein, in reponse to Toll-like receptor (TLR)-2- and TLR-3 ligands, and higher levels in response to TLR-4- or TLR-8 ligands. The same profile was observed in neonatal mononuclear cells. The supernatant of LPS-stimulated DC induced the secretion of IL-17 by polyclonally activated neonatal CD8(+) T cells, confirming the IL-23 bioactivity. Altogether, these observations strongly suggest that IL-23 could play a role in the immune system of human newborns. In particular, a functional IL-23/IL-17 axis might compensate a suboptimal IL-12/IFN-gamma pathway in early life.

  10. Does DcR1 (TNF-related apoptosis-inducing-ligand Receptor 3) have any role in human AMD pathogenesis?

    Science.gov (United States)

    Anand, Akshay; Sharma, Neel K; Singh, Ramandeep; Gupta, Amod; Prabhakar, Sudesh; Jindal, Neeru; Bhatt, Arvind K; Sharma, Suresh K; Gupta, Pawan K

    2014-02-18

    It has been postulated that there is a link between age related degenerative diseases and cancer. The TNF-related apoptosis-inducing ligand (TRAIL) has been shown to selectively kill tumor cells by binding to pro-apoptotic and anti-apoptotic receptors. Our aim was to study the levels of anti-apoptotic receptor (DcR1) in age related macular degeneration (AMD) and controls. AMD patients (115) were classified into two groups: Dry and Wet AMD. Wet AMDs were further classified into occult, predominant classic and minimal classic. 61 healthy individuals were recruited as normal controls. After normalization with total protein, DcR1 levels were analyzed by ELISA. Mann Whitney U-statistic was used for analysis of DcR1 ELISA results. We have observed DcR1 levels in serum sample which were significantly lower in AMD patients as compared to controls (p = 0.001). On the other hand, we did not find difference in DcR1 levels between wet and dry AMD. The present study defines the plausible role of DcR1 in AMD pathology signifying a new therapeutic target for AMD.

  11. Expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin on dendritic cells generated from human peripheral blood monocytes

    Institute of Scientific and Technical Information of China (English)

    Jun Li; Zhi-Hua Feng; Guang-Yu Li; Dan-Lei Mou; Qing-He Nie

    2006-01-01

    AIM: To generate dendritic cells (DCs) from human peripheral blood and to detect the expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin (DC-SIGN; CD209) for the further study of DC-SIGN in hepatitis C virus (HCV) transmission.METHODS: Peripheral blood monocytes were isolated from blood of healthy individuals by Ficoll-Hypaque sedimentation and cultured in complete medium containing rhGM-CSF and rhIL-4. Cells were cultured for seven days, with cytokine addition every two days to obtain immature DCs. Characteristics of the cultured cells were observed under light and scanning microscope, and the expression of DC-SIGN was detected by immunofluorescence staining.RESULTS: After seven-day culture, a large number of cells with typical characteristics of DCs appeared. Their characteristics were observed under light and scanning electron microscope. These cells had a variety of cell shapes such as those of bipolar elongate cells, elaborate stellate cells and DCs. DC-SIGN was detected by immunofluorescence staining and its expression level on cultivated dendritic cells was high.CONCLUSION: DCs with a high expression of DC-SIGN can be generated from human peripheral blood monocytes in complete medium containing rhGM-CSF and rhIL-4.

  12. Herpes simplex virus type 2 induces rapid cell death and functional impairment of murine dendritic cells in vitro

    NARCIS (Netherlands)

    Jones, CA; Fernandez, M; Herc, K; Bosnjak, L; Miranda-Saksena, M; Boadle, RA; Cunningham, A

    2003-01-01

    Dendritic cells (DC) are critical for stimulation of naive T cells. Little is known about the effect of herpes simplex virus type 2 (HSV-2) infection on DC structure or function or if the observed effects of HSV-1 on human DC are reproduced in murine DC. Here, we demonstrate that by 12 h

  13. Human stromal (mesenchymal) stem cells

    DEFF Research Database (Denmark)

    Aldahmash, Abdullah; Zaher, Walid; Al-Nbaheen, May

    2012-01-01

    Human stromal (mesenchymal) stem cells (hMSC) represent a group of non-hematopoietic stem cells present in the bone marrow stroma and the stroma of other organs including subcutaneous adipose tissue, placenta, and muscles. They exhibit the characteristics of somatic stem cells of self-renewal and......Human stromal (mesenchymal) stem cells (hMSC) represent a group of non-hematopoietic stem cells present in the bone marrow stroma and the stroma of other organs including subcutaneous adipose tissue, placenta, and muscles. They exhibit the characteristics of somatic stem cells of self...... of clinical applications, e.g., non-healing bone fractures and defects and also non-skeletal degenerative diseases like heart failure. Currently, the numbers of clinical trials that employ MSC are increasing. However, several biological and biotechnological challenges need to be overcome to benefit from...

  14. A three-phase current-fed dc/dc converter with a three-leg high frequency transformer for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Hanju [Department of Electrical Engineering, Chungnam National University, 220 Gung-dong Yuseong-gu, Daejeon 305-764 (Korea); Choi, Jungwan [National Fusion Research Institute, Daejeon (Korea); Enjeti, Prasad [Texas A and M University, College Station, TX 77843-3128 (United States)

    2008-07-15

    In this paper, a three-phase current-fed dc/dc converter with an active clamp is introduced, and a new three-phase three-leg high frequency transformer is proposed for the converter. The three-phase dc/dc converter transfers power through transformer leakage inductances in the discontinuous current mode; a single common active clamp branch is employed for zero-voltage switching (ZVS) in all active switches. Further, the converter's three-phase power configuration increases power transfer, and it reduces the rms current per phase, thus reduces conduction losses. Moreover, a delta-delta connection on the three-phase transformer provides parallel current paths and reduces conduction losses in the transformer windings. A three-phase transformer can be constructed by connecting three discrete single-phase transformers, but this process results in a higher volume and higher material costs. Therefore, a new three-phase three-leg high frequency transformer is designed with three discrete cores integrated into a single transformer core. The proposed transformer is analyzed according to the several operating modes of the converter, and its design rules are determined. Experimental results are obtained on a 500-W prototype unit; the design is fully verified and analyzed. (author)

  15. Immune effects of DC-CIK cells against prostate cancer cells%树突状细胞与细胞因子诱导的杀伤细胞抗前列腺癌细胞的免疫效应

    Institute of Scientific and Technical Information of China (English)

    匡幼林; 邓远忠; 梁思敏; 苟欣

    2014-01-01

    Objective To study the anti-prostate cancer immunological effect of dentritic cells(DC)and cytokine induced killers (CIK)cells after co-culture.Methods Peripheral blood mononuclear cells were isolated from healthy human and used for genera-ting DC with the treatment of recombinant human granulocyte macrophage colony stimulating factor(rhGM-CSF)and recombinant human interleukin-4(rhIL-4)as well producing CIK with interferon-γ(IFN-γ),CD3 and rhIL-2 in vitro,and then the DC and CIK were cocultured together to produce DC-CIK.The experiment was performed with four groups composed of DC group,DC-CIK group,DC-T group and CIK group.ELISA was used to detect the concentration of IL-12 and IFN-γin cultured supernatant,and the flow cytometry (FCM)was used to measure the cell phenotype,including CD3,CD8 and CD56.The lymphocytes cytotoxic activity against prostate cancer cell was analyzed by the CCK-8 way.Results The concentrations of IL-1 2 and IFN-γin the cutural super-matant in the DC-CIK group were (105.14±2.16)pg/mL and (726.28±21.35)pg/mL respectively,which were significantly higher than those in other three groups (P<0.05).Meanwhile,the expression of CD3+/CD8+ and CD3+/CD56+ were up-regula-ted significantly[(60.9±1.28)% and (27.8±1.01)%,P<0.05)].However,there is no statistics difference among the DC-CIK, DC-T and CIK groups in the CD3 expression.The cytotoxicity against prostate cancer cells was (52.31±2.14)% in the DC-CIK group,(11.14±1.02)% in the DC group,(14.19±1.63)% in the DC-T group and (34.43±2.01)% in the CIK group,the differ-ences among them had statistical significance (P<0.05).Conclusion DC-CIK can induce potent immunological effect against pros-tate cancer cells,which provides the experimental and theoretical basis for the immunotherapy of prostate cancer.%目的:探讨树突状细胞(DC)与细胞因子诱导的杀伤细胞(CIK)共培养后抗前列腺癌细胞的免疫效应。方法采集健康人外周血单个核细胞,用含重

  16. Detection of plasmacytoid dendritic cell (pDC) content in peripheral blood and renal tissue of children with henoch-schonlein purpura and its clinical value

    Institute of Scientific and Technical Information of China (English)

    Rong-Mei Xiang

    2016-01-01

    Objective:To study the plasmacytoid dendritic cell (pDC) content in peripheral blood and renal tissue of children with henoch-schonlein purpura and its clinical value.Methods:30 cases of henoch-schonlein purpura children with renal damage were enrolled in HSPN group, 30 cases of henoch-schonlein purpura children without renal damage were enrolled in NHSPN group, and 30 cases of healthy volunteers were enrolled in the control group. Then contents of pDC, Th2 cell, IL-4, IL-5, IL-10 and IL-13 in peripheral blood as well as contents of pDC, Th17 cell, IL-17, IL-21 and IL-23 in renal tissue of three groups were detected.Results: (1) pDC contents in peripheral blood of HSPN group and NHSPN group were lower than those of control group and the decrease of pDC contents in peripheral blood of HSPN group was more obvious; CD304 contents in renal tissue of HSPN group and NHSPN group were higher than those of control group and the increase of CD304 contents in renal tissue of HSPN group was more obvious; (2) Th2 cell as well as IL-4, IL-5, IL-10 and IL-13 contents in peripheral blood of HSPN group and NHSPN group were higher than those of control group and the increase of related indexes in peripheral blood of HSPN group was more obvious; Th17 cell as well as IL-17, IL-21 and IL-23 contents in kidney tissue of HSPN group were higher than those of NHSPN group; (3) in peripheral blood, pDC content was negatively correlated with Th2 cell level as well as IL-4, IL-5, IL-10 and IL-13 contents, and in renal tissue, pDC content was positively correlated with Th17 cell level as well as IL-17, IL-21 and IL-23 contents. Conclusions:Abnormal pDC content correlates with the pathogenesis of henoch-schonlein purpura, pDC content decreases in peripheral blood and will result in enhancement of Th2 cell function, and pDC content increases in kidney and will result in enhancement of Th17 cell function.

  17. In vitro priming of tumor-specific cytotoxic T lymphocytes using allogeneic dendritic cells derived from the human MUTZ-3 cell line.

    Science.gov (United States)

    Santegoets, Saskia J A M; Schreurs, Marco W J; Masterson, Allan J; Liu, Ying Poi; Goletz, Steffen; Baumeister, Hans; Kueter, Esther W M; Lougheed, Sinéad M; van den Eertwegh, Alfons J M; Scheper, Rik J; Hooijberg, Erik; de Gruijl, Tanja D

    2006-12-01

    The adoptive transfer of in vitro-induced and expanded tumor-specific cytotoxic T lymphocytes (CTL) presents a promising immunotherapeutic approach for the treatment of cancer. The in vitro induction of tumor-reactive CTL requires repeated stimulation of CTL precursors with dendritic cells (DC). To circumvent problems like scarcity of blood DC precursors and donor variability, it would be attractive to use DC from a non-autologous, unlimited source. DCs derived from the human acute myeloid leukemia (AML) cell line MUTZ-3 are attractive candidates since these DCs closely resemble monocyte-derived DC (MoDC) in terms of phenotype and T cell stimulatory capacity. Here we demonstrate that functional CTL clones could be generated against multiple tumor-associated antigens, i.e., human telomerase reverse transcriptase (hTERT), ErbB3-binding protein-1 (Ebp1), carcinoembryonic antigen (CEA) and Her-2/neu, by stimulating CD8beta(+) CTL precursors with peptide-loaded allogeneic, HLA-A2-matched MUTZ-3-derived DC. A consistent induction capacity, as determined by MHC tetramer-binding, was found in multiple donors and comparable to autologous peptide-loaded MoDC. Functional characterization at the clonal level revealed the priming of CTL that recognized endogenously processed epitopes on tumor cell lines in an HLA-A2-restricted fashion. Our data indicate that MUTZ-3-derived DC can be used as stimulator cells for in vitro priming and expansion of functional TAA-specific effector CTL. MUTZ-3-derived DCs thus represent a ready and standardized source of allogeneic DC to generate CTL for therapeutic adoptive transfer strategies.

  18. The Influence of Ouabain on Human Dendritic Cells Maturation

    Directory of Open Access Journals (Sweden)

    C. R. Nascimento

    2014-01-01

    Full Text Available Although known as a Na,K-ATPase inhibitor, several other cellular and systemic actions have been ascribed to the steroid Ouabain (Oua. Particularly in the immune system, our group showed that Ouabain acts on decreasing lymphocyte proliferation, synergizing with glucocorticoids in spontaneous thymocyte apoptosis, and also lessening CD14 expression and blocking CD16 upregulation on human monocytes. However, Ouabain effects on dendritic cells (DCs were not explored so far. Considering the peculiar plasticity and the importance of DCs in immune responses, the aim of our study was to investigate DC maturation under Ouabain influence. To generate immature DCs, human monocytes were cultured with IL-4 and GM-CSF (5 days. To investigate Ouabain role on DC activation, DCs were stimulated with TNF-α for 48 h in the presence or absence of Ouabain. TNF-induced CD83 expression and IL-12 production were abolished in DCs incubated with 100 nM Ouabain, though DC functional capacity concerning lymphocyte activation remained unaltered. Nevertheless, TNF-α-induced antigen capture downregulation, another maturation marker, occurred even in the presence of Ouabain. Besides, Ouabain increased HLA-DR and CD86 expression, whereas CD80 expression was maintained. Collectively, our results suggest that DCs respond to Ouabain maturating into a distinct category, possibly contributing to the balance between immunity and tolerance.

  19. Danger signal-dependent activation of human dendritic cells by plasma-derived factor VIII products.

    Science.gov (United States)

    Miller, L; Weissmüller, S; Ringler, E; Crauwels, P; van Zandbergen, G; Seitz, R; Waibler, Z

    2015-08-01

    Treatment of haemophilia A by infusions of the clotting factor VIII (FVIII) results in the development of inhibitors/anti-drug antibodies in up to 25 % of patients. Mechanisms leading to immunogenicity of FVIII products are not yet fully understood. Amongst other factors, danger signals as elicited upon infection or surgery have been proposed to play a role. In the present study, we focused on effects of danger signals on maturation and activation of dendritic cells (DC) in the context of FVIII application. Human monocyte-derived DC were treated with FVIII alone, with a danger signal alone or a combination of both. By testing more than 60 different healthy donors, we show that FVIII and the bacterial danger signal lipopolysaccharide synergise in increasing DC activation, as characterised by increased expression of co-stimulatory molecules and secretion of pro-inflammatory cytokines. The degree and frequency of this synergistic activation correlate with CD86 expression levels on immature DC prior to stimulation. In our assay system, plasma-derived but not recombinant FVIII products activate human DC in a danger signal-dependent manner. Further tested danger signals, such as R848 also induced DC activation in combination with FVIII, albeit not in every tested donor. In our hands, human DC but not human B cells or macrophages could be activated by FVIII in a danger signal-dependent manner. Our results suggest that immunogenicity of FVIII is a result of multiple factors including the presence of danger, predisposition of the patient, and the choice of a FVIII product for treatment.

  20. cGAS Senses Human Cytomegalovirus and Induces Type I Interferon Responses in Human Monocyte-Derived Cells

    Science.gov (United States)

    Paijo, Jennifer; Döring, Marius; Spanier, Julia; Grabski, Elena; Nooruzzaman, Mohammed; Schmidt, Tobias; Witte, Gregor; Messerle, Martin; Hornung, Veit; Kaever, Volkhard; Kalinke, Ulrich

    2016-01-01

    Human cytomegalovirus (HCMV) infections of healthy individuals are mostly unnoticed and result in viral latency. However, HCMV can also cause devastating disease, e.g., upon reactivation in immunocompromised patients. Yet, little is known about human immune cell sensing of DNA-encoded HCMV. Recent studies indicated that during viral infection the cyclic GMP/AMP synthase (cGAS) senses cytosolic DNA and catalyzes formation of the cyclic di-nucleotide cGAMP, which triggers stimulator of interferon genes (STING) and thus induces antiviral type I interferon (IFN-I) responses. We found that plasmacytoid dendritic cells (pDC) as well as monocyte-derived DC and macrophages constitutively expressed cGAS and STING. HCMV infection further induced cGAS, whereas STING expression was only moderately affected. Although pDC expressed particularly high levels of cGAS, and the cGAS/STING axis was functional down-stream of STING, as indicated by IFN-I induction upon synthetic cGAMP treatment, pDC were not susceptible to HCMV infection and mounted IFN-I responses in a TLR9-dependent manner. Conversely, HCMV infected monocyte-derived cells synthesized abundant cGAMP levels that preceded IFN-I production and that correlated with the extent of infection. CRISPR/Cas9- or siRNA-mediated cGAS ablation in monocytic THP-1 cells and primary monocyte-derived cells, respectively, impeded induction of IFN-I responses following HCMV infection. Thus, cGAS is a key sensor of HCMV for IFN-I induction in primary human monocyte-derived DC and macrophages. PMID:27058035

  1. Human plasmacytoid dendritic cells: from molecules to intercellular communication network

    Directory of Open Access Journals (Sweden)

    Till Sebastian Manuel Mathan

    2013-11-01

    Full Text Available Plasmacytoid Dendritic Cells (pDCs are a specific subset of naturally occurring dendritic cells, that secrete large amounts of Type I interferon and play an important role in the immune response against viral infection. Several studies have highlighted that they are also effective antigen presenting cells (APCs, making them an interesting target for immunotherapy against cancer. However, the modes of action of pDCs are not restricted to antigen presentation and IFN secretion alone. In this review we will highlight a selection of cell surface proteins expressed by human pDCs that may facilitate communication with other immune cells, and we will discuss the implications of these molecules for pDC-driven immune responses.

  2. Nonviral and viral gene transfer into different subsets of human dendritic cells yield comparable efficiency of transfection.

    Science.gov (United States)

    Lundqvist, Andreas; Noffz, Gabriele; Pavlenko, Maxim; Saebøe-Larssen, Stein; Fong, Timothy; Maitland, Norman; Pisa, Pavel

    2002-01-01

    Among the many promising cancer immunotherapeutic strategies, dendritic cells (DC) have become of particular interest. This study aims to optimize a clinical grade protocol for culture and transfection of human DC. Monocytes and CD34(+) hematopoietic stem cells (HSC) from same donor were differentiated under serum-free conditions and analyzed for their susceptibility to several recently described nonviral transfection methods as compared with established virally mediated gene transfer. Nonviral gene transfer methods studied were square-wave electroporation, lipofection, and particle-mediated transfer of plasmid DNA or in vitro transcribed mRNA. We conclude that DNA is not suitable for transduction of DC using nonviral methods. In contrast, mRNA and square-wave electroporation reproducibly yields 60% and 50% transfected monocyte- and CD34(+)-derived DC, respectively, measured at protein level, without affecting the cell viability. Thus, the transfection efficiency of this method is comparable with the 40-90% transgene expression obtained using retroviral (RV) or adenoviral (AdV) vectors in CD34(+)- and monocyte-derived DC, respectively. In monocyte-derived DC, however, the amount of protein expressed per-cell basis was higher after AdV (MOI = 1000) compared with mRNA electroporation-mediated transfer. This is the first study directly demonstrating side-by-side that mRNA electroporation into DC of different origin indeed results in a comparable number of transduced cells as when using virus-mediated gene transfer.

  3. Messenger RNA electroporation of human monocytes, followed by rapid in vitro differentiation, leads to highly stimulatory antigen-loaded mature dendritic cells.

    Science.gov (United States)

    Ponsaerts, Peter; Van den Bosch, Glenn; Cools, Nathalie; Van Driessche, Ann; Nijs, Griet; Lenjou, Marc; Lardon, Filip; Van Broeckhoven, Christine; Van Bockstaele, Dirk R; Berneman, Zwi N; Van Tendeloo, Viggo F I

    2002-08-15

    Dendritic cells (DC) are professional Ag-capturing and -presenting cells of the immune system. Because of their exceptional capability of activating tumor-specific T cells, cancer vaccination research is now shifting toward the formulation of a clinical human DC vaccine. We developed a short term and serum-free culture protocol for rapid generation of fully mature, viable, and highly stimulatory CD83(+) DC. Human monocytes were cultured for 24 h in serum-free AIM-V medium, followed by 24-h maturation by polyriboinosinic polyribocytidylic acid (polyI:C). Short term cultured, polyI:C-maturated DC, far more than immature DC, showed typical mature DC markers and high allogeneic stimulatory capacity and had high autologous stimulatory capacity in an influenza model system using peptide-pulsed DC. Electroporation of mRNA as an Ag-loading strategy in these cells was optimized using mRNA encoding the enhanced green fluorescent protein (EGFP). Monocytes electroporated with EGFP mRNA, followed by short term, serum-free differentiation to mature DC, had a phenotype of DC, and all showed positive EGFP fluorescence. Influenza matrix protein mRNA-electroporated monocytes cultured serum-free and maturated with polyI:C showed high stimulatory capacity in autologous T cell activation experiments. In conclusion, the present short term and serum-free ex vivo DC culture protocol in combination with mRNA electroporation at the monocyte stage imply an important reduction in time and consumables for preparation of Ag-loaded mature DC compared with classical DC culture protocols and might find application in clinical immunotherapy settings.

  4. Soft-Switched Dual-Input DC-DC Converter Combining a Boost-Half-Bridge Cell and a Voltage-Fed Full-Bridge Cell

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    for various applications, such as fuel cell and super-capacitor hybrid energy system. By fully using two high frequency transformers and a shared leg of switches, number of the power devices and associated gate driver circuits can be reduced. With phase-shift control, the converter can achieve ZVS turn...

  5. DC-SIGN/DC-SIGNR基因多态性与病原微生物感染%Polymorphisms of DC-SIGN/DC-SIGNR and pathogen infection

    Institute of Scientific and Technical Information of China (English)

    许利军; 潘晨; 李勤光

    2010-01-01

    DC-SIGN和DC-SIGNR是两种表达于DC表面的蛋白,被认为是许多病原微生物的黏附受体,参与很多病原微生物的感染.DC-SIGN和DC-SIGNR(DC-SIGN/DC-SIGNR)的多态性或许影响病原微生物的感染过程和结果.此文对DC-SIGN/DC-SIGNR的结构功能以及与HIV、HCV感染、肺结核、登革热的关系进行了综述.%DC-SIGN and DC-SIGNR are two surface proteins on dendritic cells with complex stmction, and are regarded as attachment receptors of many pathogens, DC-SIGN/DC-SIGNR participate in pathogen infection.Polymorphisms of DC-SIGN/DC-SIGNR probably influence the procedure and outcome of pathogen infection. In this article, the structure and function of DC-SIGN/DC-SIGNR are discussed as well as the relation between the DC-SIGN/DC-SIGNR and pathogens such as HIV, HCV infection, pulmonary tuberculosis, dengue fever.

  6. Levamisole enhances immune response by affecting the activation and maturation of human monocyte-derived dendritic cells

    Science.gov (United States)

    Chen, L-Y; Lin, Y-L; Chiang, B-L

    2008-01-01

    Levamisole is a synthetic phenylimidazolthiazole that was first introduced in 1966 as an anti-helmintic agent. Current studies have been focused upon its effect on immune response and on cancer treatment. We examined the molecular mechanisms of levamisole in the activation and maturation of human monocyte-derived dendritic cells (DC) and human T cells. Treatment of DC with levamisole increased the presentation of CD80, CD86, CD83 and human leucocyte antigen D-related (HLA-DR) molecules on the cell membrane, as well as the production of interleukin (IL)-12 p40 and IL-10. Levamisole-treated human DC also enhanced T cell activation towards type 1 T helper immune response by inducing interferon-γ secretion. Neutralization with antibodies against Toll-like receptor (TLR)-2 inhibited levamisole-induced production of IL-12 p40 and IL-10, suggesting a vital role for TLR-2 in signalling DC upon incubation with levamisole. The inhibition of nuclear factor-κB, extracellular signal-regulated kinases 1/2 or c-Jun N-terminal kinases pathways also prevented the effects of levamisole on DC in producing IL-12 p40 or IL-10. Taken together, levamisole could enhance immune response towards T helper 1 development through the activation of dendritic cells or T cell aspects. PMID:18005262

  7. Human monocyte-derived dendritic cells from leukoreduction system chambers after plateletpheresis are functional in an in vitro co-culture assay with intestinal epithelial cells.

    Science.gov (United States)

    Tiscornia, Inés; Sánchez-Martins, Viviana; Hernández, Ana; Bollati-Fogolín, Mariela

    2012-10-31

    The dendritic cells (DC) found in the intestine are involved both in the maintenance of tolerance towards commensal microbiota, and in the generation of protective immune responses against pathogens, thus contributing to gut immune homeostasis. There is an increasing interest in the use of lactic acid bacteria (LAB) as probiotics; among their beneficial effects we highlight the modulation of the immune system which is one of their fundamental properties. As these effects are strain-dependent, it is important to have in vitro systems that include DC and intestinal epithelial cells (IEC), which are crucial for intestinal homeostasis, to identify candidates by means of bacterial screening. Obtaining enough human cells, necessary to simultaneously test several bacteria, is a major challenge for researchers. In this study we analyzed the usefulness of the cellular fraction retained in leukoreduction system chambers following plateletpheresis (PP) as a source of DC. We compared the capacity of peripheral blood mononuclear cells (PBMC) from buffy coats (BC) or PP to generate DC using a short differentiation protocol. The functionality of the DC obtained was analyzed in co-cultures together with intestinal epithelial HT-29 cells, stimulating with LPS alone or with two LAB commonly used in the food industry, Streptococcus thermophilus and Lactobacillus delbrueckii. DC surface markers CD86, HLA-DR and cytokine production were measured. The behavior of DC derived from PP was similar to the behavior observed for DC derived from BC. When we tested the response of DC to bacteria, we found significant differences in cytokine secretion, especially for IL-10, suggesting that the system has the ability to discriminate LAB with different immunomodulatory properties. We also found that DC derived from both sources displayed a similar ability to phagocyte bacteria. In conclusion, we hereby propose a modification of the two-day protocol for obtaining human DC previously described, using

  8. Gene expression profiling of human monocyte-derived dendritic cells - Searching for molecular regulators of tolerogenicity

    Directory of Open Access Journals (Sweden)

    Katina eSchinnerling

    2015-10-01

    Full Text Available The ability of dendritic cells (DCs to initiate and modulate antigen-specific immune responses has made them attractive targets for immunotherapy. Since DC research in humans is limited by the scarcity of DC populations in the blood circulation, most of our knowledge about DC biology and function has been obtained in vitro from monocyte-derived DCs (moDCs, which can be readily generated in sufficient numbers and are able to differentiate into distinct functional subsets depending on the nature of stimulus. In particular, moDCs with tolerogenic properties (tolDCs possess great therapeutic potential for the treatment of autoimmune diseases. Several protocols have been developed to generate tolDCs in vitro, able to reinstruct auto-reactive T cells and to promote regulatory cells. While ligands and soluble mediators, by which DCs shape immune responses, have been vastly studied, the intracellular pathways and transcriptional regulators that govern tolDC differentiation and function are poorly understood. Whole-genome microarrays and proteomics provide useful strategies to dissect the complex molecular processes that promote tolerogenicity. Only few attempts have been made to understand tolDC biology through a global view on ‘omics’ profiles. So far, the identification of a common regulator of tolerogenicity has been hampered by the fact that each protocol, used for tolDC generation, targets distinct signaling pathways. Here we review the progress in understanding the transcriptional regulation of moDC differentiation, with a special focus on tolDCs, and highlight candidate molecules that might be associated with DC tolerogenicity.

  9. Molecular Mechanisms Regulating Human Dendritic Cell Development, Survival and Function

    NARCIS (Netherlands)

    L. van de Laar (Lianne)

    2011-01-01

    textabstractDendritic cells (DC) are professional antigen presenting cells (APC) with a dual function in the immune system. On the one hand, these specialized leukocytes are equipped to alert the immune system to invading pathogens or other danger signals. On the other, DC can promote tolerogenic re

  10. Dysregulated immune profiles for skin and dendritic cells are associated with increased host susceptibility to Haemophilus ducreyi infection in human volunteers.

    Science.gov (United States)

    Humphreys, Tricia L; Li, Lang; Li, Xiaoman; Janowicz, Diane M; Fortney, Kate R; Zhao, Qianqian; Li, Wei; McClintick, Jeanette; Katz, Barry P; Wilkes, David S; Edenberg, Howard J; Spinola, Stanley M

    2007-12-01

    In experimentally infected human volunteers, the cutaneous immune response to Haemophilus ducreyi is orchestrated by serum, polymorphonuclear leukocytes, macrophages, T cells, and myeloid dendritic cells (DC). This response either leads to spontaneous resolution of infection or progresses to pustule formation, which is associated with the failure of phagocytes to ingest the organism and the presence of Th1 and regulatory T cells. In volunteers who are challenged twice, some subjects form at least one pustule twice (PP group), while others have all inoculated sites resolve twice (RR group). Here, we infected PP and RR subjects with H. ducreyi and used microarrays to profile gene expression in infected and wounded skin. The PP and RR groups shared a core response to H. ducreyi. Additional transcripts that signified effective immune function were differentially expressed in RR infected sites, while those that signified a hyperinflammatory, dysregulated response were differentially expressed in PP infected sites. To examine whether DC drove these responses, we profiled gene expression in H. ducreyi-infected and uninfected monocyte-derived DC. Both groups had a common response that was typical of a type 1 DC (DC1) response. RR DC exclusively expressed many additional transcripts indicative of DC1. PP DC exclusively expressed differentially regulated transcripts characteristic of DC1 and regulatory DC. The data suggest that DC from the PP and RR groups respond differentially to H. ducreyi. PP DC may promote a dysregulated T-cell response that contributes to phagocytic failure, while RR DC may promote a Th1 response that facilitates bacterial clearance.

  11. Sustained excitability elevations induced by transcranial DC motor cortex stimulation in humans.

    Science.gov (United States)

    Nitsche, M A; Paulus, W

    2001-11-27

    The authors show that in the human transcranial direct current stimulation is able to induce sustained cortical excitability elevations. As revealed by transcranial magnetic stimulation, motor cortical excitability increased approximately 150% above baseline for up to 90 minutes after the end of stimulation. The feasibility of inducing long-lasting excitability modulations in a noninvasive, painless, and reversible way makes this technique a potentially valuable tool in neuroplasticity modulation.

  12. Peptide-loaded dendritic cells prime and activate MHC-class I-restricted T cells more efficiently than protein-loaded cross-presenting DC

    DEFF Research Database (Denmark)

    Met, Ozcan; Buus, Søren; Claesson, Mogens H

    2003-01-01

    -pulsed DC. Moreover, SIINFEKL-loaded DC were up to 50 times more efficient than DC-pulsed with OVA-protein for generation of an H-2K(b)-restricted response. Immunization of mice with SIINFEKL-loaded DC resulted in a much stronger H-2K(b)-restricted response than immunization with OVA-pulsed DC. These data...

  13. Differential cytotoxicity of long-chain bases for human oral gingival epithelial keratinocytes, oral fibroblasts, and dendritic cells

    Directory of Open Access Journals (Sweden)

    Leslie A. Mehalick

    2015-12-01

    Full Text Available Long-chain bases, found in the oral cavity, have potent antimicrobial activity against oral pathogens. In an article associated with this dataset, Poulson and colleagues determined the cytotoxicities of long-chain bases (sphingosine, dihydrosphingosine, and phytosphingosine for human oral gingival epithelial (GE keratinocytes, oral gingival fibroblasts (GF, dendritic cells (DC, and squamous cell carcinoma (SCC cell lines [1]. Poulson and colleagues found that GE keratinocytes were more resistant to long-chain bases as compared to GF, DC, and SCC cell lines [1]. In this study, we assess the susceptibility of DC to lower concentrations of long chain bases. 0.2–10.0 µM long-chain bases and GML were not cytotoxic to DC; 40.0–80.0 µM long-chain bases, but not GML, were cytotoxic for DC; and 80.0 µM long-chain bases were cytotoxic to DC and induced cellular damage and death in less than 20 mins. Overall, the LD50 of long-chain bases for GE keratinocytes, GF, and DC were considerably higher than their minimal inhibitory concentrations for oral pathogens, a finding important to pursuing their future potential in treating periodontal and oral infections.

  14. Simplified dc to dc converter

    Science.gov (United States)

    Gruber, R. P. (Inventor)

    1984-01-01

    A dc to dc converter which can start with a shorted output and which regulates output voltage and current is described. Voltage controlled switches directed current through the primary of a transformer the secondary of which includes virtual reactance. The switching frequency of the switches is appropriately varied to increase the voltage drop across the virtual reactance in the secondary winding to which there is connected a low impedance load. A starting circuit suitable for voltage switching devices is provided.

  15. Human embryonic stem cells handbook

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Redi

    2013-03-01

    Full Text Available After the Nobel prize in physiology or medicine was awarded jointly to Sir John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent it became imperative to write down the review for a book entirely devoted to human embryonic stem cells (hES, those cells that are a urgent need for researchers, those cells that rekindle the ethical debates and finally, last but not least, those cells whose study paved the way to obtain induced pluripotent stem cells by the OSKC’s Yamanaka method (the OSKC acronim refers, for those not familiar with the topic, to the four stemness genes used to transfect somatic fibroblasts: Oct4, Sox2, Klf4 and c-Myc....

  16. Gene expression profiles of human dendritic cells interacting with Aspergillus fumigatus in a bilayer model of the alveolar epithelium/endothelium interface.

    Directory of Open Access Journals (Sweden)

    Charles Oliver Morton

    Full Text Available The initial stages of the interaction between the host and Aspergillus fumigatus at the alveolar surface of the human lung are critical in the establishment of aspergillosis. Using an in vitro bilayer model of the alveolus, including both the epithelium (human lung adenocarcinoma epithelial cell line, A549 and endothelium (human pulmonary artery epithelial cells, HPAEC on transwell membranes, it was possible to closely replicate the in vivo conditions. Two distinct sub-groups of dendritic cells (DC, monocyte-derived DC (moDC and myeloid DC (mDC, were included in the model to examine immune responses to fungal infection at the alveolar surface. RNA in high quantity and quality was extracted from the cell layers on the transwell membrane to allow gene expression analysis using tailored custom-made microarrays, containing probes for 117 immune-relevant genes. This microarray data indicated minimal induction of immune gene expression in A549 alveolar epithelial cells in response to germ tubes of A. fumigatus. In contrast, the addition of DC to the system greatly increased the number of differentially expressed immune genes. moDC exhibited increased expression of genes including CLEC7A, CD209 and CCL18 in the absence of A. fumigatus compared to mDC. In the presence of A. fumigatus, both DC subgroups exhibited up-regulation of genes identified in previous studies as being associated with the exposure of DC to A. fumigatus and exhibiting chemotactic properties for neutrophils, including CXCL2, CXCL5, CCL20, and IL1B. This model closely approximated the human alveolus allowing for an analysis of the host pathogen interface that complements existing animal models of IA.

  17. Gene expression profiles of human dendritic cells interacting with Aspergillus fumigatus in a bilayer model of the alveolar epithelium/endothelium interface.

    Science.gov (United States)

    Morton, Charles Oliver; Fliesser, Mirjam; Dittrich, Marcus; Mueller, Tobias; Bauer, Ruth; Kneitz, Susanne; Hope, William; Rogers, Thomas Richard; Einsele, Hermann; Loeffler, Juergen

    2014-01-01

    The initial stages of the interaction between the host and Aspergillus fumigatus at the alveolar surface of the human lung are critical in the establishment of aspergillosis. Using an in vitro bilayer model of the alveolus, including both the epithelium (human lung adenocarcinoma epithelial cell line, A549) and endothelium (human pulmonary artery epithelial cells, HPAEC) on transwell membranes, it was possible to closely replicate the in vivo conditions. Two distinct sub-groups of dendritic cells (DC), monocyte-derived DC (moDC) and myeloid DC (mDC), were included in the model to examine immune responses to fungal infection at the alveolar surface. RNA in high quantity and quality was extracted from the cell layers on the transwell membrane to allow gene expression analysis using tailored custom-made microarrays, containing probes for 117 immune-relevant genes. This microarray data indicated minimal induction of immune gene expression in A549 alveolar epithelial cells in response to germ tubes of A. fumigatus. In contrast, the addition of DC to the system greatly increased the number of differentially expressed immune genes. moDC exhibited increased expression of genes including CLEC7A, CD209 and CCL18 in the absence of A. fumigatus compared to mDC. In the presence of A. fumigatus, both DC subgroups exhibited up-regulation of genes identified in previous studies as being associated with the exposure of DC to A. fumigatus and exhibiting chemotactic properties for neutrophils, including CXCL2, CXCL5, CCL20, and IL1B. This model closely approximated the human alveolus allowing for an analysis of the host pathogen interface that complements existing animal models of IA.

  18. Efficacy of DC-CIK combined with chemotherapy in the treatment of advanced non small cell lung cancer%DC-CIK联合化疗治疗晚期非小细胞肺癌的疗效分析

    Institute of Scientific and Technical Information of China (English)

    张士法

    2016-01-01

    Objective:To investigate the therapeutic effect of DC-CIK combined with chemotherapy in patients with advanced non-small cell lung cancer.Methods:120 patients with advanced non small cell lung cancer were selected.They were divided into two groups.The control group was treated with chemotherapy alone.The observation group was treated with DC-CIK combined with chemotherapy.The treatment effect and adverse reaction of the two groups were compared.Results:The effective rate of the observation group was significantly higher than that of the control group,and the incidence of adverse reactions was significantly lower than that of the control group(P<0.05).Conclusion:DC-CIK combined with chemotherapy in the treatment of advanced non-small cell lung cancer can significantly improve the patient's treatment effect,enhance the ability to resist cancer,and reduce the incidence of adverse reactions.%目的:探讨 DC-CIK 联合化疗在晚期非小细胞肺癌中的治疗效果。方法:收治晚期非小细胞肺癌患者120例,分两组,对照组给予单纯化疗治疗,观察组给予DC-CIK联合化疗治疗,比较两组患者的治疗效果和不良反应的发生情况。结果:观察组的治疗有效率明显高于对照组,不良反应的发生率明显低于对照组(P<0.05)。结论:DC-CIK联合化疗在晚期非小细胞肺癌的治疗中,能够明显提高患者的治疗效果,增强抗肿瘤能力,减少不良反应的发生。

  19. HIV delays IFN-α production from human plasmacytoid dendritic cells and is associated with SYK phosphorylation.

    Directory of Open Access Journals (Sweden)

    Calvin C Lo

    Full Text Available Plasmacytoid dendritic cells (pDC are the major producers of type I interferons (IFNs in humans and rapidly produce IFN-α in response to virus exposure. Although HIV infection is associated with pDC activation, it is unclear why the innate immune response is unable to effectively control viral replication. We systematically compared the effect of HIV, Influenza, Sendai, and HSV-2 at similar target cell multiplicity of infection (M.O.I. on human pDC function. We found that Influenza, Sendai, HSV-2 and imiquimod are able to rapidly induce IFN-α production within 4 hours to maximal levels, whereas HIV had a delayed induction that was maximal only after 24 hours. In addition, maximal IFN-α induction by HIV was at least 10 fold less than that of the other viruses in the panel. HIV also induced less TNF-α and MIP-1β but similar levels of IP-10 compared to other viruses, which was also mirrored by delayed upregulation of pDC activation markers CD83 and CD86. BDCA-2 has been identified as an inhibitory receptor on pDC, signaling through a pathway that involves SYK phosphorylation. We find that compared to Influenza, HIV induces the activation of the SYK pathway. Thus, HIV delays pDC IFN-α production and pDC activation via SYK phosphorylation, allowing establishment of viral populations.

  20. Modelling the electric field and the current density generated by cerebellar transcranial DC stimulation in humans.

    Science.gov (United States)

    Parazzini, Marta; Rossi, Elena; Ferrucci, Roberta; Liorni, Ilaria; Priori, Alberto; Ravazzani, Paolo

    2014-03-01

    Transcranial Direct Current Stimulation (tDCS) over the cerebellum (or cerebellar tDCS) modulates working memory, changes cerebello-brain interaction, and affects locomotion in humans. Also, the use of tDCS has been proposed for the treatment of disorders characterized by cerebellar dysfunction. Nonetheless, the electric field (E) and current density (J) spatial distributions generated by cerebellar tDCS are unknown. This work aimed to estimate E and J distributions during cerebellar tDCS. Computational electromagnetics techniques were applied in three human realistic models of different ages and gender. The stronger E and J occurred mainly in the cerebellar cortex, with some spread (up to 4%) toward the occipital cortex. Also, changes by ±1cm in the position of the active electrode resulted in a small effect (up to 4%) in the E and J spatial distribution in the cerebellum. Finally, the E and J spreads to the brainstem and the heart were negligible, thus further supporting the safety of this technique. Despite inter-individual differences, our modeling study confirms that the cerebellum is the structure mainly involved by cerebellar tDCS. Modeling approach reveals that during cerebellar tDCS the current spread to other structures outside the cerebellum is unlike to produce functional effects. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Zeuthen, Louise Hjerrild; Ferlazzo, Guido

    2007-01-01

    , in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells......The intestinal microbiota is essential for homeostasis of the local and systemic immune system, and particularly strains of lactic acid bacteria and Escherichia coli have been shown to have balancing effects on inflammatory conditions such as allergy and inflammatory bowel disease. However...... (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production...

  2. Low CCR7-mediated migration of human monocyte derived dendritic cells in response to human respiratory syncytial virus and human metapneumovirus.

    Directory of Open Access Journals (Sweden)

    Cyril Le Nouën

    2011-06-01

    Full Text Available Human respiratory syncytial virus (HRSV and, to a lesser extent, human metapneumovirus (HMPV and human parainfluenza virus type 3 (HPIV3, can re-infect symptomatically throughout life without significant antigenic change, suggestive of incomplete or short-lived immunity. In contrast, re-infection by influenza A virus (IAV largely depends on antigenic change, suggestive of more complete immunity. Antigen presentation by dendritic cells (DC is critical in initiating the adaptive immune response. Antigen uptake by DC induces maturational changes that include decreased expression of the chemokine receptors CCR1, CCR2, and CCR5 that maintain DC residence in peripheral tissues, and increased expression of CCR7 that mediates the migration of antigen-bearing DC to lymphatic tissue. We stimulated human monocyte-derived DC (MDDC with virus and found that, in contrast to HPIV3 and IAV, HMPV and HRSV did not efficiently decrease CCR1, 2, and 5 expression, and did not efficiently increase CCR7 expression. Consistent with the differences in CCR7 mRNA and protein expression, MDDC stimulated with HRSV or HMPV migrated less efficiently to the CCR7 ligand CCL19 than did IAV-stimulated MDDC. Using GFP-expressing recombinant virus, we showed that the subpopulation of MDDC that was robustly infected with HRSV was particularly inefficient in chemokine receptor modulation. HMPV- or HRSV-stimulated MDDC responded to secondary stimulation with bacterial lipopolysaccharide or with a cocktail of proinflammatory cytokines by increasing CCR7 and decreasing CCR1, 2 and 5 expression, and by more efficient migration to CCL19, suggesting that HMPV and HRSV suboptimally stimulate rather than irreversibly inhibit MDDC migration. This also suggests that the low concentration of proinflammatory cytokines released from HRSV- and HMPV-stimulated MDDC is partly responsible for the low CCR7-mediated migration. We propose that inefficient migration of HRSV- and HMPV-stimulated DC to

  3. Synthesis of ZnO nanopowders by DC thermal plasma for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo-Jung; Choi, Jinsub [Department of Chemical Engineering, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of); Park, Dong-Wha, E-mail: dwpark@inha.ac.kr [Department of Chemical Engineering, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of)

    2013-05-01

    Highlights: ► ZnO nanopowders were synthesized using DC thermal plasma process. ► Type and flow rate of reaction gas were controlled as experimental variables. ► Various morphologies were identified by changing the reaction gas. ► The photovoltaic performances were promoted by removing the unreacted precursors. ► DSSCs based on 1D nanostructure ZnO show the enhanced energy conversion efficiency. -- Abstract: Zinc oxide (ZnO) nanopowders were synthesized from commercially available micro-sized zinc powders (Aldrich Co., 98%, 10 μm) by a DC thermal plasma process at atmospheric pressure. The micro-sized zinc powders were vaporized in the plasma region, after which the plasma processing equipment was rapidly quenched, resulting in the formation of ZnO nanopowders with a size of less than 300 nm. Two different reaction gases of oxygen and carbon dioxide were used as the oxygen source and each gas flow rate was controlled as a process variable. The obtained ZnO nanopowders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). All synthesized ZnO nanopowders showed high crystalline wurtzite structures and the differences in their morphologies were strongly dependent on the operating variables. The photocurrent–voltage (J–V) curve of the ZnO nanopowders with a dye of ruthenium (II) 535 bis-TBA (N719, Solaronix) in redox electrolyte showed an overall energy conversion efficiency (η) of 2.54%, demonstrating that the application of the mass-producible ZnO nanopowders by thermal plasma processing to DSSC was feasible.

  4. The anti-cancer effect of PC-3 sensitized DC vaccine on human immune reconstruction NOD/SCID mice model bearing human prostate carcinoma%DC疫苗对荷人前列腺癌免疫重建NOD/SCID小鼠的抑瘤作用

    Institute of Scientific and Technical Information of China (English)

    周海滨; 付强

    2016-01-01

    目的 探讨PC-3细胞冻融抗原致敏的树突状细胞(dendritic cells,DC)疫苗(PC-3-DC)对荷人前列腺癌免疫重建NOD/SCID小鼠(hu-PBL-NOD/SCID)的抑瘤作用.方法 采用人外周血淋巴细胞(peripheral blood lymphocytes,PBL)腹腔注射法建立hu-PBL-NOD/SCID小鼠模型,随机分为实验组(PC-3-DC组)和对照组(DC组、PBS组),腹腔分别注射PC-3-DC疫苗、未致敏的DC和PBS.每周1次,共2次,然后接种1×107 PC-3细胞,观察鼠成瘤率、成瘤潜伏期、肿瘤体积以及测定特异性CTL活性.结果 ELISA法可检测到小鼠血清中人IgG水平,hu-PBL-NOD/SCID嵌合模型重建成功,各组小鼠间成瘤率无明显差异,但PC-3-DC组成瘤潜伏期延长,肿瘤生长缓慢,2周后肿瘤体积明显小于DC组和PBS组,差异有统计学意义(P<0.05),实验组脾淋巴细胞对PC-3细胞有特异性杀伤效应,而对K562细胞则无杀伤活性.结论 负载PC-3冻融抗原的DC疫苗可诱导人T淋巴细胞活化增殖,能有效抑制hu-PBL-NOD/SCID小鼠肿瘤的生长.%Objectives To investigate the effect of dendritic cells (DC) stimulated with PC-3 cells lysate inhibiting tumor action in human immune reconstruction NOD/SCID mice model bearing human prostate carcinoma.Methods Human immune reconstruction NOD/SCID mice model was established by intraperitoneal injection of human peripheral blood lymphocytes.The PC-3 DC vaccine,naive DC,PBS were injected respectively,and then they were injected subcutaneously with 1 × 107 PC -3 cells.Tumorigenic rate,latent period,and tumor volume were observed,and specific CTL activity was measured.Results The serum concentration of human lgG in hu-PBL-NOD/SCID mice model was confirmed by ELISA that suggested that the hu-PBL-NOD/SCID mice model was established successfully.Tumorigenic rates were the same among these groups.However,tumors grew slowly in PC-3 DC vaccine groups,and its latent period was prolonged.Tumor volumes were significantly smaller than those in control group

  5. Human IDO-competent, long-lived immunoregulatory dendritic cells induced by intracellular pathogen, and their fate in humanized mice

    Science.gov (United States)

    Tyagi, Rajeev K.; Miles, Brodie; Parmar, Rajesh; Garg, Neeraj K.; Dalai, Sarat K.; Baban, Babak; Cutler, Christopher W.

    2017-01-01

    Targeting of myeloid-dendritic cell receptor DC-SIGN by numerous chronic infectious agents, including Porphyromonas gingivalis, is shown to drive-differentiation of monocytes into dysfunctional mDCs. These mDCs exhibit alterations of their fine-tuned homeostatic function and contribute to dysregulated immune-responses. Here, we utilize P. gingivalis mutant strains to show that pathogen-differentiated mDCs from primary human-monocytes display anti-apoptotic profile, exhibited by elevated phosphorylated-Foxo1, phosphorylated-Akt1, and decreased Bim-expression. This results in an overall inhibition of DC-apoptosis. Direct stimulation of complex component CD40 on DCs leads to activation of Akt1, suggesting CD40 involvement in anti-apoptotic effects observed. Further, these DCs drove dampened CD8+ T-cell and Th1/Th17 effector-responses while inducing CD25+Foxp3+CD127− Tregs. In vitro Treg induction was mediated by DC expression of indoleamine 2,3-dioxygenase, and was confirmed in IDO-KO mouse model. Pathogen-infected & CMFDA-labeled MoDCs long-lasting survival was confirmed in a huMoDC reconstituted humanized mice. In conclusion, our data implicate PDDCs as an important target for resolution of chronic infection. PMID:28198424

  6. Cytotoxic components of Pereskia bleo (Kunth) DC. (Cactaceae) leaves.

    Science.gov (United States)

    Malek, Sri Nurestri Abdul; Shin, Sim Kae; Wahab, Norhanom Abdul; Yaacob, Hashim

    2009-05-06

    Dihydroactinidiolide (1) and a mixture of sterols [campesterol (2), stigmasterol (3) and beta-sitosterol (4)], together with the previously isolated individual compounds beta-sitosterol (4), 2,4-di-tert-butylphenol (5), alpha-tocopherol (6), phytol (7) were isolated from the active ethyl acetate fraction of Pereskia bleo (Kunth) DC. (Cactaceae) leaves. Cytotoxic activities of the above mentioned compounds against five human carcinoma cell lines, namely the human nasopharyngeal epidermoid carcinoma cell line (KB), human cervical carcinoma cell line (CasKi), human colon carcinoma cell line (HCT 116), human hormone-dependent breast carcinoma cell line (MCF7) and human lung carcinoma cell line (A549); and non-cancer human fibroblast cell line (MRC-5) were investigated. Compound 5 possessed very remarkable cytotoxic activity against KB cells, with an IC(50 )value of 0.81microg/mL. This is the first report on the cytotoxic activities of the compounds isolated from Pereskia bleo.

  7. Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation.

    Science.gov (United States)

    Fink, Lisbeth N; Zeuthen, Louise H; Ferlazzo, Guido; Frøkiaer, Hanne

    2007-12-01

    The intestinal microbiota is essential for homeostasis of the local and systemic immune system, and particularly strains of lactic acid bacteria and Escherichia coli have been shown to have balancing effects on inflammatory conditions such as allergy and inflammatory bowel disease. However, in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN-gamma production was also mediated by all types of APC. The most potent responses were induced by monocyte-derived DC, which thus constitute a sensitive screening model.

  8. NF-κBp50参与IL-4在THP-1细胞中诱导DC-SIGN的表达%NF-κBp50 is Associated With DC-SIGN Expression Induced by IL-4 in THP-1 Cells

    Institute of Scientific and Technical Information of China (English)

    许利军; 常秀春; 姚航平; 吴南屏

    2008-01-01

    DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) is specific receptor on Dendritic cells, and plays a pivotal role on antigens presentation. Uptodate, the clear regulation mechanisms for DC-SIGN expression are not available.IL-4 is one of the most important cytokines inducing DC-SIGN production, while, NF-κB is an important transcription factor controlling signaling transduction. Both IL-4 and NF-κB are closely related to DC-SIGN regulation. NF-κB and IL-4 actions on DC-SIGN promoter activity, DC-SIGN expression as well as interactions between IL-4 and NF-κB were investigated in THP-1 cell. It was found that the mutation of NF-κB binding site in DC-SIGN promoter results in DC-SIGN promoter activity decrease about 50%.NF-κBp50 stimulates DC-SIGN expression in THP-1 cells. IL-4 upregulates DC-SIGN expression on THP-1 cells as well as NF-κB production. These data reveal that NF-κB is associated with IL-4 induced DC-SIGN expression.%树突状细胞表面特异的胞间黏附分子3捕获非整合素(DC-specific intercellular adhesion molecule-3-grabbing nonintegrin,DC-SIGN)是树突状细胞表面特异的蛋白,在抗原呈递过程中起关键作用.这种特异性的表达和DC-SIGN的调节机制有关.到目前为止,DC-SIGN表达调控的机制还不是很清楚.IL-4是诱导DC-SIGN表达的最重要的细胞因子之一,而NF-κB是调控细胞信号转导的一个重要调控因子,两者都和DC-SIGN的表达调节相关.研究了IL-4和NF-κB对DC-SIGN启动子活性、对DC-SIGN表达的影响以及IL-4和NF-κB之间相互作用的关系.发现:DC-SIGN启动子中NF-κB位点缺失可以使DC-SIGN启动子活性下降大约50%,NF-κBp50可以促进DC-SIGN在THP-1细胞的表达,IL-在THP-1细胞诱导DC-SIGN表达的同时,也促进了NF-κBp50的表达.这些结果显示,在THP-1细胞中NF-κBp50参与IL-4诱导的DC-SIGN表达.

  9. Human fetal mesenchymal stem cells.

    Science.gov (United States)

    O'Donoghue, Keelin; Chan, Jerry

    2006-09-01

    Stem cells have been isolated at all stages of development from the early developing embryo to the post-reproductive adult organism. However, the fetal environment is unique as it is the only time in ontogeny that there is migration of stem cells in large numbers into different organ compartments. While fetal neural and haemopoietic stem cells (HSC) have been well characterised, only recently have mesenchymal stem cells from the human fetus been isolated and evaluated. Our group have characterised in human fetal blood, liver and bone marrow a population of non-haemopoietic, non-endothelial cells with an immunophenotype similar to adult bone marrow-derived mesenchymal stem cells (MSC). These cells, human fetal mesenchymal stem cells (hfMSC), are true multipotent stem cells with greater self-renewal and differentiation capacity than their adult counterparts. They circulate in first trimester fetal blood and have been found to traffic into the maternal circulation, engrafting in bone marrow, where they remain microchimeric for decades after pregnancy. Though fetal microchimerism has been implicated in the pathogenesis of autoimmune disease, the biological role of hfMSC microchimerism is unknown. Potential downstream applications of hfMSC include their use as a target cell for non-invasive pre-natal diagnosis from maternal blood, and for fetal cellular and gene therapy. Using hfMSC in fetal therapy offers the theoretical advantages of avoidance of immune rejection, increased engraftment, and treatment before disease pathology sets in. Aside from allogeneic hfMSC in utero transplantation, the use of autologous hfMSC has been brought a step forward with the development of early blood sampling techniques, efficient viral transduction and clonal expansion. Work is ongoing to determine hfMSC fate post-transplantation in murine models of genetic disease. In this review we will examine what is known about hfMSC biology, as well as discussing areas for future research. The

  10. DAP12 deficiency in liver allografts results in enhanced donor DC migration, augmented effector T cell responses and abrogation of transplant tolerance.

    Science.gov (United States)

    Yoshida, O; Kimura, S; Dou, L; Matta, B M; Yokota, S; Ross, M A; Geller, D A; Thomson, A W

    2014-08-01

    Liver interstitial dendritic cells (DC) have been implicated in immune regulation and tolerance induction. We found that the transmembrane immuno-adaptor DNAX-activating protein of 12 kDa (DAP12) negatively regulated conventional liver myeloid (m) DC maturation and their in vivo migratory and T cell allostimulatory ability. Livers were transplanted from C57BL/6(H2(b) ) (B6) WT or DAP12(-/-) mice into WT C3H (H2(k) ) recipients. Donor mDC (H2-K(b+) CD11c(+) ) were quantified in spleens by flow cytometry. Anti-donor T cell reactivity was evaluated by ex vivo carboxyfluorescein diacetate succinimidyl ester-mixed leukocyte reaction and delayed-type hypersensitivity responses, while T effector and regulatory T cells were determined by flow analysis. A threefold to fourfold increase in donor-derived DC was detected in spleens of DAP12(-/-) liver recipients compared with those given WT grafts. Moreover, pro-inflammatory cytokine gene expression in the graft, interferon gamma (IFNγ) production by graft-infiltrating CD8(+) T cells and systemic levels of IFNγ were all elevated significantly in DAP12(-/-) liver recipients. DAP12(-/-) grafts also exhibited reduced incidences of CD4(+) Foxp3(+) cells and enhanced CD8(+) T cell IFNγ secretion in response to donor antigen challenge. Unlike WT grafts, DAP12(-/-) livers failed to induce tolerance and were rejected acutely. Thus, DAP12 expression in liver grafts regulates donor mDC migration to host lymphoid tissue, alloreactive T cell responses and transplant tolerance.

  11. Harnessing human plasmacytoid dendritic cells as professional APCs

    NARCIS (Netherlands)

    Tel, J.; Leun, A.M. van der; Figdor, C.G.; Torensma, R.; Vries, I.J.M. de

    2012-01-01

    The plasmacytoid dendritic cell (pDC) constitutes a unique DC subset that links the innate and adaptive arm of the immune system. Whereas the unique capability of pDCs to produce large amounts of type I IFNs in response to pathogen recognition is generally accepted,their antigen-presenting function

  12. CLEC12A-Mediated Antigen Uptake and Cross-Presentation by Human Dendritic Cell Subsets Efficiently Boost Tumor-Reactive T Cell Responses.

    Science.gov (United States)

    Hutten, Tim J A; Thordardottir, Soley; Fredrix, Hanny; Janssen, Lisanne; Woestenenk, Rob; Tel, Jurjen; Joosten, Ben; Cambi, Alessandra; Heemskerk, Mirjam H M; Franssen, Gerben M; Boerman, Otto C; Bakker, Lex B H; Jansen, Joop H; Schaap, Nicolaas; Dolstra, Harry; Hobo, Willemijn

    2016-10-01

    Potent immunotherapies are urgently needed to boost antitumor immunity and control disease in cancer patients. As dendritic cells (DCs) are the most powerful APCs, they are an attractive means to reinvigorate T cell responses. An appealing strategy to use the effective Ag processing and presentation machinery, T cell stimulation and cross-talk capacity of natural DC subsets is in vivo tumor Ag delivery. In this context, endocytic C-type lectin receptors are attractive targeting molecules. In this study, we investigated whether CLEC12A efficiently delivers tumor Ags into human DC subsets, facilitating effective induction of CD4(+) and CD8(+) T cell responses. We confirmed that CLEC12A is selectively expressed by myeloid cells, including the myeloid DC subset (mDCs) and the plasmacytoid DC subset (pDCs). Moreover, we demonstrated that these DC subsets efficiently internalize CLEC12A, whereupon it quickly translocates to the early endosomes and subsequently routes to the lysosomes. Notably, CLEC12A Ab targeting did not negatively affect DC maturation or function. Furthermore, CLEC12A-mediated delivery of keyhole limpet hemocyanin resulted in enhanced proliferation and cytokine secretion by keyhole limpet hemocyanin-experienced CD4(+) T cells. Most importantly, CLEC12A-targeted delivery of HA-1 long peptide resulted in efficient Ag cross-presentation by mDCs and pDCs, leading to strong ex vivo activation of HA-1-specific CD8(+) T cells of patients after allogeneic stem cell transplantation. Collectively, these data indicate that CLEC12A is an effective new candidate with great potential for in vivo Ag delivery into mDCs and pDCs, thereby using the specialized functions and cross-talk capacity of these DC subsets to boost tumor-reactive T cell immunity in cancer patients.

  13. Modulation of tolerogenic dendritic cells and autoimmunity.

    Science.gov (United States)

    Kim, Sun Jung; Diamond, Betty

    2015-05-01

    A key function of dendritic cells (DCs) is to induce either immune tolerance or immune activation. Many new DC subsets are being recognized, and it is now clear that each DC subset has a specialized function. For example, different DC subsets may express different cell surface molecules and respond differently to activation by secretion of a unique cytokine profile. Apart from intrinsic differences among DC subsets, various immune modulators in the microenvironment may influence DC function; inappropriate DC function is closely related to the development of immune disorders. The most exciting recent advance in DC biology is appreciation of human DC subsets. In this review, we discuss functionally different mouse and human DC subsets both in lymphoid organs and non-lymphoid organs, the molecules that regulate DC function, and the emerging understanding of the contribution of DCs to autoimmune diseases.

  14. Fucose-specific DC-SIGN signalling directs T helper cell type-2 responses via IKKε- and CYLD-dependent Bcl3 activation.

    Science.gov (United States)

    Gringhuis, Sonja I; Kaptein, Tanja M; Wevers, Brigitte A; Mesman, Annelies W; Geijtenbeek, Teunis B H

    2014-05-28

    Carbohydrate-specific signalling through DC-SIGN provides dendritic cells with plasticity to tailor immunity to the nature of invading microbes. Here we demonstrate that recognition of fucose-expressing extracellular pathogens like Schistosoma mansoni and Helicobacter pylori by DC-SIGN favors T helper cell type-2 (TH2) responses via activation of atypical NF-κB family member Bcl3. Crosstalk between TLR and DC-SIGN signalling results in TLR-induced MK2-mediated phosphorylation of LSP1, associated with DC-SIGN, upon fucose binding. Subsequently, IKKε and CYLD are recruited to phosphorylated LSP1. IKKε activation is pivotal for suppression of CYLD deubiquitinase activity and subsequent nuclear translocation of ubiquitinated Bcl3. Bcl3 activation represses TLR-induced proinflammatory cytokine expression, while enhancing interleukin-10 (IL-10) and TH2-attracting chemokine expression, shifting TH differentiation from TH1 to TH2 polarization. Thus, DC-SIGN directs adaptive TH2 immunity to fucose-expressing pathogens via an IKKε-CYLD-dependent signalling pathway leading to Bcl3 activation, which might be targeted in vaccination strategies or to prevent aberrant inflammation and allergy.

  15. Differentiated human stem cells resemble fetal, not adult, β cells.

    Science.gov (United States)

    Hrvatin, Sinisa; O'Donnell, Charles W; Deng, Francis; Millman, Jeffrey R; Pagliuca, Felicia Walton; DiIorio, Philip; Rezania, Alireza; Gifford, David K; Melton, Douglas A

    2014-02-25

    Human pluripotent stem cells (hPSCs) have the potential to generate any human cell type, and one widely recognized goal is to make pancreatic β cells. To this end, comparisons between differentiated cell types produced in vitro and their in vivo counterparts are essential to validate hPSC-derived cells. Genome-wide transcriptional analysis of sorted insulin-expressing (INS(+)) cells derived from three independent hPSC lines, human fetal pancreata, and adult human islets points to two major conclusions: (i) Different hPSC lines produce highly similar INS(+) cells and (ii) hPSC-derived INS(+) (hPSC-INS(+)) cells more closely resemble human fetal β cells than adult β cells. This study provides a direct comparison of transcriptional programs between pure hPSC-INS(+) cells and true β cells and provides a catalog of genes whose manipulation may convert hPSC-INS(+) cells into functional β cells.

  16. Vaccination of metastatic melanoma patients with autologous dendritic cell (DC derived-exosomes: results of thefirst phase I clinical trial

    Directory of Open Access Journals (Sweden)

    Piperno Sophie

    2005-03-01

    Full Text Available Abstract Background DC derived-exosomes are nanomeric vesicles harboring functional MHC/peptide complexes capable of promoting T cell immune responses and tumor rejection. Here we report the feasability and safety of the first Phase I clinical trial using autologous exosomes pulsed with MAGE 3 peptides for the immunization of stage III/IV melanoma patients. Secondary endpoints were the monitoring of T cell responses and the clinical outcome. Patients and methods Exosomes were purified from day 7 autologous monocyte derived-DC cultures. Fifteen patients fullfilling the inclusion criteria (stage IIIB and IV, HLA-A1+, or -B35+ and HLA-DPO4+ leukocyte phenotype, tumor expressing MAGE3 antigen were enrolled from 2000 to 2002 and received four exosome vaccinations. Two dose levels of either MHC class II molecules (0.13 versus 0.40 × 1014 molecules or peptides (10 versus 100 μg/ml were tested. Evaluations were performed before and 2 weeks after immunization. A continuation treatment was performed in 4 cases of non progression. Results The GMP process allowed to harvest about 5 × 1014 exosomal MHC class II molecules allowing inclusion of all 15 patients. There was no grade II toxicity and the maximal tolerated dose was not achieved. One patient exhibited a partial response according to the RECIST criteria. This HLA-B35+/A2+ patient vaccinated with A1/B35 defined CTL epitopes developed halo of depigmentation around naevi, a MART1-specific HLA-A2 restricted T cell response in the tumor bed associated with progressive loss of HLA-A2 and HLA-BC molecules on tumor cells during therapy with exosomes. In addition, one minor, two stable and one mixed responses were observed in skin and lymph node sites. MAGE3 specific CD4+ and CD8+ T cell responses could not be detected in peripheral blood. Conclusion The first exosome Phase I trial highlighted the feasibility of large scale exosome production and the safety of exosome administration.

  17. Characterization of CD8+ T-Cell Responses in the Peripheral Blood and Skin Injection Sites of Melanoma Patients Treated with mRNA Electroporated Autologous Dendritic Cells (TriMixDC-MEL

    Directory of Open Access Journals (Sweden)

    Daphné Benteyn

    2013-01-01

    Full Text Available Treatment of melanoma patients with mRNA electroporated dendritic cells (TriMixDC-MEL stimulates T-cell responses against the presented tumor-associated antigens (TAAs. In the current clinical trials, melanoma patients with systemic metastases are treated, requiring priming and/or expansion of preexisting TAA-specific T cells that are able to migrate to both the skin and internal organs. We monitored the presence of TAA-specific CD8+ T cells infiltrating the skin at sites of intradermal TriMixDC-MEL injection (SKILs and within the circulation of melanoma patients treated in two clinical trials. In 10 out of fourteen (71% patients screened, CD8+ T cells recognizing any of the four TAA presented by TriMixDC-MEL cellular vaccine were found in both compartments. In total, 30 TAA-specific T-cell responses were detected among the SKILs and 29 among peripheral blood T cells, of which 24 in common. A detailed characterization of the antigen specificity of CD8+ T-cell populations in four patients indicates that the majority of the epitopes detected were only recognized by CD8+ T cells derived from either skin biopsies or peripheral blood, indicating that some compartmentalization occurs after TriMix-DC therapy. To conclude, functional TAA-specific CD8+ T cells distribute both to the skin and peripheral blood of patients after TriMixDC-MEL therapy.

  18. Alignment and Elongation of Human Adipose-Derived Stem Cells in Response to Direct-Current Electrical Stimulation

    OpenAIRE

    Tandon, Nina; Goh, Brian; Marsano, Anna; Chao, Pen-Hsiu Grace; Montouri-Sorrentino, Chrystina; Gimble, Jeffrey; Vunjak-Novakovic, Gordana

    2009-01-01

    In vivo, direct current electric fields are present during embryonic development and wound healing. In vitro, direct current (DC) electric fields induce directional cell migration and elongation. For the first time, we demonstrate that cultured human adipose tissue-derived stem cells (hASCs) respond to the presence of direct-current electric fields. Cells were stimulated for 2–4 hours with DC electric fields of 6 V/cm that were similar to those encountered in vivo post-injury. Upon stimulatio...

  19. GENETICALLY MODIFIED DENDRITIC CELLS INDUCED SPECIFIC CYTOTOXITY AGAINST HUMAN HCC CELLS IN VITRO

    Institute of Scientific and Technical Information of China (English)

    刘彬彬; 叶胜龙; 贺平; 郑宁; 赵燕; 孙瑞霞; 刘银坤; 汤钊猷

    2004-01-01

    Objective: to transduce the tumor associated antigen gene MAGE-1 and/or IL-12 gene into dendritic cells (DC) and to observe the in vitro cytotoxic effect induced by the genetically modified DC against the human hepatocellular carcinoma (HCC) cell line SMMC7721. Methods: the MAGE-1 gene was inserted into the retrovirus vector LXSN to construct the recombinant retrovirus LMSN. The monocyte-derived DCs were transfected at appropriate differentiation stage by LMSN and/or a recombinant adenovirus AdmiL-12, which containing murine IL-12 gene. The control groups included retrovirus LXSN transfected, adenovirus AdBGFP transfected and non-transfected DCs. The MAGE-1 gene expression was identified by western blot and the mIL-12 p70 secretion was detected by ELISA assay. The in vitro cytotoxicities against SMMC7721 induced by genetically modified and control groups of DC were tested by MTT assay. Results: The MAGE-1 expression was detected by a monoclonal antibody in DCs tranfected with LMSN but not in control groups. At 16 h, 24 h and 48 h after transfection with AdmIL-12, the concentration of the mIL-12 p70 in the culture medium was 580pg/106 cells, 960pg/106 cells and 1100pg/106 cells respectively. The mIL-12 p70 secretions were not detected in other groups. The lytic activity (as judged by % lysis) induced by each groups of DC was 94.2(5.2% (LMSN and AdmIL-12 cotransfected group), 78.9(3.6% (LMSN transfected groups), 52.6(9.7% (AdmIL-12 transfected group), 34.7(4.3% (LXSN transfected group), 36.3(3.8% (AdBGFP transfected group) and 3.9(2.0% (non-transfected group) respectively. Except for LXSN transfected and AdBGFP transfected group, the difference of the lytic activities between other groups were statistically significant (P<0.05). Conclusion: The MAGE-1 gene modified DCs can induce relatively specific cytotoxicty against SMMC7721 in vitro and thus suggested that those genetically engineered DCs have the potential to serve as novel vaccine for HCC. Transduction of

  20. Characterization of hematopoietic GATA transcription factor expression in mouse and human dendritic cells.

    Science.gov (United States)

    Scheenstra, Maaike R; Salunkhe, Vishal; De Cuyper, Iris M; Hoogenboezem, Mark; Li, Eveline; Kuijpers, Taco W; van den Berg, Timo K; Gutiérrez, Laura

    2015-12-01

    Dendritic cells (DCs) are key initiators and regulators of the immune response. The development of the DC lineage and their subsets requires an orchestrated regulation of their transcriptional program. Gata1, a transcription factor expressed in several hematopoietic cell lineages, has been recently reported to be required for mouse DC development and function. In humans, GATA1 is involved in the lineage separation between monocyte-derived DCs and Langerhans cells (LC) and loss of GATA1 results in differentiation arrest at the monocyte stage. The hematopoietic GATA factors (i.e. Gata1, Gata2, Gata3) are known to regulate each other's expression and to function consecutively throughout lineage commitment (so-called GATA switch). In humans, mutations in GATA2 are causative of MonoMAC disease, a human immunodeficiency syndrome characterized by loss of DCs, monocytes, B and NK cells. However, additional data on the expression of hematopoietic GATA factors in the DC lineage is missing. In this study, we have characterized the expression of hematopoietic GATA factors in murine and human DCs and their expression dynamics upon TLR stimulation. We found that all hematopoietic GATA factors are expressed in DCs, but identified species-specific differences in the relative expression of each GATA factor, and how their expression fluctuates upon stimulation.

  1. The lectins griffithsin, cyanovirin-N and scytovirin inhibit HIV-1 binding to the DC-SIGN receptor and transfer to CD4+ cells

    CSIR Research Space (South Africa)

    Alexandre, Kabamba B

    2012-02-01

    Full Text Available -1 Virology 423 (2012) 175?186 The lectins griffithsin, cyanovirin-N and scytovirin inhibit HIV-1 binding to the DC-SIGN receptor and transfer to CD4+ cells Kabamba B. Alexandre a, Elin S. Gray a, Hazel Mufhandu b, James B. McMahon c, Ereck Chakauya b...

  2. Borrelia burgdorferi infection regulates CD1 expression in human cells and tissues via IL1-β.

    Science.gov (United States)

    Yakimchuk, Konstantin; Roura-Mir, Carme; Magalhaes, Kelly G; de Jong, Annemieke; Kasmar, Anne G; Granter, Scott R; Budd, Ralph; Steere, Allen; Pena-Cruz, Victor; Kirschning, Carsten; Cheng, Tan-Yun; Moody, D Branch

    2011-03-01

    The appearance of group 1 CD1 proteins (CD1a, CD1b and CD1c) on maturing myeloid DC is a key event that converts myeloid DC to effective lipid APC. Here, we show that Borrelia burgdorferi, the causative agent of Lyme disease, triggers appearance of group 1 CD1 proteins at high density on the surface of human myeloid DC during infection. Within human skin, CD1b and CD1c expression was low or absent prior to infection, but increased significantly after experimental infections and in erythema migrans lesions from Lyme disease patients. The induction of CD1 was initiated by borrelial lipids acting through TLR-2 within minutes, but required 3 days for maximum effect. The delay in CD1 protein appearance involved a multi-step process whereby TLR-2 stimulated cells release soluble factors, which are sufficient to transfer the CD1-inducing effect in trans to other cells. Analysis of these soluble factors identified IL-1β as a previously unknown pathway leading to group 1 CD1 protein function. This study establishes that upregulation of group 1 CD1 proteins is an early event in B. burgdorferi infection and suggests a stepwise mechanism whereby bacterial cell walls, TLR activation and cytokine release cause DC precursors to express group 1 CD1 proteins.

  3. DC-ATLAS : a systems biology resource to dissect receptor specific signal transduction in dendritic cells

    NARCIS (Netherlands)

    Cavalieri, D.; Rivero, D.; Beltrame, L.; Buschow, S.I.; Calura, E.; Rizzetto, L.; Gessani, S.; Gauzzi, M.C.; Reith, W.; Baur, A.; Bonaiuti, R.; Brandizi, M.; Filippo, C. De; D'Oro, U.; Draghici, S.; Dunand-Sauthier, I.; Gatti, E.; Granucci, F.; Gundel, M.; Kramer, M.; Kuka, M.; Lanyi, A.; Melief, C.J.; Montfoort, N. van; Ostuni, R.; Pierre, P.; Popovici, R.; Rajnavolgyi, E.; Schierer, S.; Schuler, G.; Soumelis, V.; Splendiani, A.; Stefanini, I.; Torcia, M.G.; Zanoni, I.; Zollinger, R.; Figdor, C.G.; Austyn, J.M.

    2010-01-01

    BACKGROUND: The advent of Systems Biology has been accompanied by the blooming of pathway databases. Currently pathways are defined generically with respect to the organ or cell type where a reaction takes place. The cell type specificity of the reactions is the foundation of immunological research,

  4. DC-ATLAS : a systems biology resource to dissect receptor specific signal transduction in dendritic cells

    NARCIS (Netherlands)

    Cavalieri, D.; Rivero, D.; Beltrame, L.; Buschow, S.I.; Calura, E.; Rizzetto, L.; Gessani, S.; Gauzzi, M.C.; Reith, W.; Baur, A.; Bonaiuti, R.; Brandizi, M.; Filippo, C. De; D'Oro, U.; Draghici, S.; Dunand-Sauthier, I.; Gatti, E.; Granucci, F.; Gundel, M.; Kramer, M.; Kuka, M.; Lanyi, A.; Melief, C.J.; Montfoort, N. van; Ostuni, R.; Pierre, P.; Popovici, R.; Rajnavolgyi, E.; Schierer, S.; Schuler, G.; Soumelis, V.; Splendiani, A.; Stefanini, I.; Torcia, M.G.; Zanoni, I.; Zollinger, R.; Figdor, C.G.; Austyn, J.M.

    2010-01-01

    BACKGROUND: The advent of Systems Biology has been accompanied by the blooming of pathway databases. Currently pathways are defined generically with respect to the organ or cell type where a reaction takes place. The cell type specificity of the reactions is the foundation of immunological research,

  5. Feasibility Study of Coal Gasification/Fuel Cell/Cogeneration Project. Washington, DC Site. Project Description

    Science.gov (United States)

    1985-06-01

    the cell stacks; - Maintenance for the expander, compresor and generator is typical of that for rotating equipment. Fuel cell stacks are periodically...steel, with mist eliminator designed for 157 psig at 150OF, 3’-8" diameter x 7’-6" high 0-204 Tar separator - coalescer plates in- stalled in fabricated

  6. Myeloid dendritic cells are potential players in human neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Paola eBossù

    2015-12-01

    Full Text Available Alzheimer’s (AD and Parkinson’s (PD diseases are devastating neurodegenerative disturbances wherein neuroinflammation is a chronic pathogenic process with high therapeutic potential. Major mediators of AD/PD neuroimmune processes are resident immune cells, but immune cells derived from periphery may also participate and to some extent modify neuroinflammation. Specifically, blood borne myeloid cells emerge as crucial components of AD/PD progression and susceptibility. Among these, dendritic cells (DCs are key immune orchestrators and players of brain immune surveillance: we candidate them as potential mediators of both AD and PD and as relevant cell model for unraveling myeloid cell role in neurodegeneration. Hence, we recapitulate and discuss emerging data suggesting that blood-derived DCs play a role in experimental and human neurodegenerative diseases. In humans, in particular, DCs are modified by in vitro culture with neurodegeneration-associated pathogenic factors and dysregulated in AD patients, while the levels of DC precursors are decreased in AD and PD patients’ blood, possibly as an index of their recruitment to the brain. Overall, we emphasize the need to explore the impact of DCs on neurodegeneration to uncover peripheral immune mechanisms of pathogenic importance, recognize potential biomarkers and improve therapeutic approaches for neurodegenerative diseases.

  7. Indoor pollutant hexabromocyclododecane enhances house dust mite-induced activation of human monocyte-derived dendritic cells.

    Science.gov (United States)

    Canbaz, Derya; Lebre, M Cristina; Logiantara, Adrian; van Ree, Ronald; van Rijt, Leonie S

    2016-11-01

    The indoor pollutant hexabromocyclododecane (HBCD) has been added as flame retardant to many consumer products but detaches and accumulates in house dust. Inhalation of house dust leads to exposure to house dust mite (HDM) allergens in the presence of HBCD. Activation of dendritic cells is crucial in the sensitization to HDM allergens. The current study examined whether exposure to HBCD affected activation/maturation of HDM-exposed human dendritic cells (DC). Human monocyte-derived DC (moDC) were exposed simultaneously to HDM and a concentration range of HBCD (0.1-20 μM) in vitro. HDM exposure of moDC induced expression of co-stimulatory molecule CD80 and production of pro-inflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α. However, simultaneous exposure of moDC to HBCD and HDM enhanced the expression of antigen presenting molecule HLA-DR, co-stimulatory molecule CD86 and pro-inflammatory cytokine IL-8 depending on the dose of HBCD. Our results indicate that simultaneous exposure of HDM and HBCD can enhance the antigen presentation and maturation/activation of DC.

  8. Indium-tin oxide films obtained by DC magnetron sputtering for improved Si heterojunction solar cell applications

    Science.gov (United States)

    Gu, Jin-Hua; Si, Jia-Le; Wang, Jiu-Xiu; Feng, Ya-Yang; Gao, Xiao-Yong; Lu, Jing-Xiao

    2015-11-01

    The indium-tin oxide (ITO) film as the antireflection layer and front electrodes is of key importance to obtaining high efficiency Si heterojunction (HJ) solar cells. To obtain high transmittance and low resistivity ITO films by direct-current (DC) magnetron sputtering, we studied the impacts of the ITO film deposition conditions, such as the oxygen flow rate, pressure, and sputter power, on the electrical and optical properties of the ITO films. ITO films of resistivity of 4×10-4 Ω·m and average transmittance of 89% in the wavelength range of 380-780 nm were obtained under the optimized conditions: oxygen flow rate of 0.1 sccm, pressure of 0.8 Pa, and sputtering power of 110 W. These ITO films were used to fabricate the single-side HJ solar cell without an intrinsic a-Si:H layer. However, the best HJ solar cell was fabricated with a lower sputtering power of 95 W, which had an efficiency of 11.47%, an open circuit voltage (Voc) of 0.626 V, a filling factor (FF) of 0.50, and a short circuit current density (Jsc) of 36.4 mA/cm2. The decrease in the performance of the solar cell fabricated with high sputtering power of 110 W is attributed to the ion bombardment to the emitter. The Voc was improved to 0.673 V when a 5 nm thick intrinsic a-Si:H layer was inserted between the (p) a-Si:H and (n) c-Si layer. The higher Voc of 0.673 V for the single-side HJ solar cell implies the excellent c-Si surface passivation by a-Si:H. Project supported by the National High Technology Research and Development Program of China (Grant No. 2011AA050501).

  9. Indium-tin oxide films obtained by DC magnetron sputtering for improved Si heterojunction solar cell applications

    Institute of Scientific and Technical Information of China (English)

    谷锦华; 司嘉乐; 王九秀; 冯亚阳; 郜小勇; 卢景霄

    2015-01-01

    The indium–tin oxide (ITO) film as the antireflection layer and front electrodes is of key importance to obtaining high efficiency Si heterojunction (HJ) solar cells. To obtain high transmittance and low resistivity ITO films by direct-current (DC) magnetron sputtering, we studied the impacts of the ITO film deposition conditions, such as the oxygen flow rate, pressure, and sputter power, on the electrical and optical properties of the ITO films. ITO films of resistivity of 4×10−4Ω·m and average transmittance of 89%in the wavelength range of 380–780 nm were obtained under the optimized conditions:oxygen flow rate of 0.1 sccm, pressure of 0.8 Pa, and sputtering power of 110 W. These ITO films were used to fabricate the single-side HJ solar cell without an intrinsic a-Si:H layer. However, the best HJ solar cell was fabricated with a lower sputtering power of 95 W, which had an efficiency of 11.47%, an open circuit voltage (Voc) of 0.626 V, a filling factor (FF) of 0.50, and a short circuit current density (Jsc) of 36.4 mA/cm2. The decrease in the performance of the solar cell fabricated with high sputtering power of 110 W is attributed to the ion bombardment to the emitter. The Voc was improved to 0.673 V when a 5 nm thick intrinsic a-Si:H layer was inserted between the (p) a-Si:H and (n) c-Si layer. The higher Voc of 0.673 V for the single-side HJ solar cell implies the excellent c-Si surface passivation by a-Si:H.

  10. The potency of human testicular stem cells

    NARCIS (Netherlands)

    Chikhovskaya, J.V.

    2013-01-01

    In this thesis, we evaluate the stem cell state of cells present in primary human testicular cell cultures as well as their origin and relation to germ or somatic lineages within testicular tissue. We conclude that human testis-derived embryonic stem cell-like (htES-like) colonies arising in primary

  11. Isolerad DC/DC-omvandlare

    OpenAIRE

    Andersson, Martin

    2011-01-01

    1 SammanfattningCrossControl är ett företag som bland annat tillverkar integrerade datorlösningar. Datorerna drivs normalt med 18-30 VDC och förbrukar som mest 50W. Datorerna säljs till flertalet olika kunder som monterar dem i allt från skogsmaskiner till tåg. I de olika fordonen varierar spänningen i de befintliga elnäten. Detta skapar behovet av att omvandla spänningen till en nivå som datorerna klarar av. En sådan apparat kallas DC/DC-omvandlare. Spänningsomvandling kan utföras genom linj...

  12. NOD/scid IL-2Rgnull mice: a preclinical model system to evaluate human dendritic cell-based vaccine strategies in vivo

    Directory of Open Access Journals (Sweden)

    Spranger Stefani

    2012-02-01

    Full Text Available Abstract Background To date very few systems have been described for preclinical investigations of human cellular therapeutics in vivo. However, the ability to carry out comparisons of new cellular vaccines in vivo would be of substantial interest for design of clinical studies. Here we describe a humanized mouse model to assess the efficacy of various human dendritic cell (DC preparations. Two reconstitution regimes of NOD/scid IL2Rgnull (NSG mice with adult human peripheral blood mononuclear cells (PBMC were evaluated for engraftment using 4-week and 9-week schedules. This led to selection of a simple and rapid protocol for engraftment and vaccine evaluation that encompassed 4 weeks. Methods NSG recipients of human PBMC were engrafted over 14 days and then vaccinated twice with autologous DC via intravenous injection. Three DC vaccine formulations were compared that varied generation time in vitro (3 days versus 7 days and signals for maturation (with or without Toll-like receptor (TLR3 and TLR7/8 agonists using MART-1 as a surrogate antigen, by electroporating mature DC with in vitro transcribed RNA encoding full length protein. After two weekly vaccinations, the splenocyte populations containing human lymphocytes were recovered 7 days later and assessed for MART-1-specific immune responses using MHC-multimer-binding assays and functional assessment of specific killing of melanoma tumor cell lines. Results Human monocyte-derived DC generated in vitro in 3 days induced better MART-1-specific immune responses in the autologous donor T cells present in the humanized NSG mice. Moreover, consistent with our in vitro observations, vaccination using mature DC activated with TLR3 and TLR7/8 agonists resulted in enhanced immune responses in vivo. These findings led to a ranking of the DC vaccine effects in vivo that reflected the hierarchy previously found for these mature DC variations in vitro. Conclusions This humanized mouse model system enables

  13. Anti-tumor effects of fusion vaccine prepared by renal cell carcinoma 786-O cell line and peripheral blood dendritic cells of healthy volunteers in vitro and in human immune reconstituted SCID mice.

    Science.gov (United States)

    Hu, Zhi; Liu, Shihui; Mai, Xuancheng; Hu, Zili; Liu, Chuan

    2010-01-01

    Dendritic cells (DC), as professional antigen presenting cells, play the central role in the process of body initiating the anti-tumor immunity, and the study on DC anti-tumor vaccine has become heated in recent years. In this study, we used polyethylene glycol (PEG) to induce renal cell carcinoma (RCC) 786-O cell line fused with peripheral blood DC of healthy volunteers, and discuss the biological characteristics of fusion vaccine and its anti-tumor effects in vitro and in human immune reconstituted SCID mice model of RCC. The study found that PEG could effectively induce cell fusion, and the expressions of CD86 and HLA-DR in fusion vaccine group were significantly up-regulated compared with the DC control group; the secretion of IL-12 was much higher and longer than that of the control; the functions of dendritic cell-tumor fusion vaccine to stimulate the proliferation of allogenic T lymphocytes and to kill RCC786-O cells in vitro were significantly higher than those of the control group, and after the killing, apoptosis body was observed in the target cells; after the injection of fusion vaccine into human immune reconstituted SCID mice model of RCC786-O via vena caudalis, the volume of mice tumor was reduced significantly, proliferation index of tumor cells decreased obviously compared with that of the control group, and more hemorrhage and putrescence focuses presented, accompanying large quantity of lymphocytes soakage. The results of this experimental study shows that fusion vaccine of RCC786-O cell line and DC can significantly stimulate the proliferation of allogenic T cells and specifically inhibit and kill RCC cells in vitro and in vivo, which makes the DC-RCC786-O fusion vaccine a possible new way of effective RCC immunotherapy.

  14. Characterization of expression, cytokine regulation, and effector function of the high affinity IgG receptor Fc gamma RI (CD64) expressed on human blood dendritic cells.

    Science.gov (United States)

    Fanger, N A; Voigtlaender, D; Liu, C; Swink, S; Wardwell, K; Fisher, J; Graziano, R F; Pfefferkorn, L C; Guyre, P M

    1997-04-01

    The mechanisms responsible for efficient sequestration of Ag by cells of the dendritic cell (DC) lineage remain incompletely characterized. One pathway, internalization of Ag-IgG complexes via CD32 (the type II IgG FcR, Fc gamma RII) enhances Ag presentation 100-fold over noncomplexed Ag. Blood leukocytes differentially express two additional IgG FcR, Fc gamma RI (CD64) and Fc gamma RIII (CD16), which may also participate in leukocyte functions such as phagocytosis, Ab-dependent cellular cytotoxicity (ADCC), release of oxygen intermediates, and enhancement of Ag presentation. A phagocytically active form of CD64 was recently demonstrated on human blood DC, but complete functional potential of CD64 on the DC lineage remains undefined. Therefore, highly purified human blood DC (CD33(2)+, CD14-, CD11c2+, HLA-DR3+, CD64+ (CD83+ after overnight culture)) and monocytes (CD33(2)+, CD14(3)+, CD11c2+, HLA-DR+, CD64(2)+, CD83-) were compared for cytokine modulation and effector functions of CD64. Both DC and monocyte CD64 expression was increased by IFN-gamma and IL-10, but while monocyte CD64 was decreased by IL-4, DC CD64 remained unchanged. FcR-mediated functional differences were also evident between the DC and the monocytes. Monocytes generated robust Fc gamma R-dependent superoxide anion release and ADCC activity, while DC failed to release reactive oxygen intermediates and demonstrated minimal ADCC activity, despite apparently normal expression of the gamma-chain subunit and the signaling molecule Syk. In contrast, DC were more efficient than monocytes with respect to T cell activation when Ag was targeted specifically to CD64. These new findings suggest a previously unappreciated potential for CD64 to shape the immune response by dramatically increasing the efficiency with which DC sequester Ag prior to achieving full T cell stimulatory potential.

  15. Human Dendritic Cell Functional Specialization in Steady-State and Inflammation

    OpenAIRE

    Arjan eBoltjes; Femke eVan Wijk

    2014-01-01

    Dendritic cells (DC) represent a heterogeneous population of antigen-presenting cells that are crucial in initiating and shaping immune responses. Although all DC are capable of antigen-uptake, processing, and presentation to T cells, DC subtypes differ in their origin, location, migration patterns, and specialized immunological roles. While in recent years, there have been rapid advances in understanding DC subset ontogeny, development, and function in mice, relatively little is known about ...

  16. Stem cell differentiation and human liver disease

    Institute of Scientific and Technical Information of China (English)

    Wen-Li Zhou; Claire N Medine; Liang Zhu; David C Hay

    2012-01-01

    Human stem cells are scalable cell populations capable of cellular differentiation.This makes them a very attractive in vitro cellular resource and in theory provides unlimited amounts of primary cells.Such an approach has the potential to improve our understanding of human biology and treating disease.In the future it may be possible to deploy novel stem cell-based approaches to treat human liver diseases.In recent years,efficient hepatic differentiation from human stem cells has been achieved by several research groups including our own.In this review we provide an overview of the field and discuss the future potential and limitations of stem cell technology.

  17. New sample cell configuration for wide-frequency dielectric spectroscopy: DC to radio frequencies.

    Science.gov (United States)

    Nakanishi, Masahiro; Sasaki, Yasutaka; Nozaki, Ryusuke

    2010-12-01

    A new configuration for the sample cell to be used in broadband dielectric spectroscopy is presented. A coaxial structure with a parallel plate capacitor (outward parallel plate cell: OPPC) has made it possible to extend the frequency range significantly in comparison with the frequency range of the conventional configuration. In the proposed configuration, stray inductance is significantly decreased; consequently, the upper bound of the frequency range is improved by two orders of magnitude from the upper limit of conventional parallel plate capacitor (1 MHz). Furthermore, the value of capacitance is kept high by using a parallel plate configuration. Therefore, the precision of the capacitance measurement in the lower frequency range remains sufficiently high. Finally, OPPC can cover a wide frequency range (100 Hz-1 GHz) with an appropriate admittance measuring apparatus such as an impedance or network analyzer. The OPPC and the conventional dielectric cell are compared by examining the frequency dependence of the complex permittivity for several polar liquids and polymeric films.

  18. U.S. Department of Energy Hydrogen and Fuel Cells Program 2016 Annual Merit Review and Peer Evaluation Report: June 6-10, 2016, Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    Popovich, Neil

    2016-10-01

    The fiscal year 2016 U.S. Department of Energy (DOE) Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting (AMR), in conjunction with DOE's Vehicle Technologies Office AMR, was held from June 6-10, 2015, in Washington, D.C.. This report is a summary of comments by AMR peer reviewers about the hydrogen and fuel cell projects funded by DOE's Office of Energy Efficiency and Renewable Energy.

  19. A role for multidrug resistance protein 4 (MRP4; ABCC4) in human dendritic cell migration.

    Science.gov (United States)

    van de Ven, Rieneke; Scheffer, George L; Reurs, Anneke W; Lindenberg, Jelle J; Oerlemans, Ruud; Jansen, Gerrit; Gillet, Jean-Pierre; Glasgow, Joel N; Pereboev, Alexander; Curiel, David T; Scheper, Rik J; de Gruijl, Tanja D

    2008-09-15

    The capacity of dendritic cells (DCs) to migrate from peripheral organs to lymph nodes (LNs) is important in the initiation of a T cell-mediated immune response. The ATP-binding cassette (ABC) transporters P-glycoprotein (P-gp; ABCB1) and the multidrug resistance protein 1 (MRP1; ABCC1) have been shown to play a role in both human and murine DC migration. Here we show that a more recently discovered family member, MRP4 (ABCC4), is expressed on both epidermal and dermal human skin DCs and contributes to the migratory capacity of DCs. Pharmacological inhibition of MRP4 activity or down-regulation through RNAi in DCs resulted in reduced migration of DCs from human skin explants and of in vitro generated Langerhans cells. The responsible MRP4 substrate remains to be identified as exogenous addition of MRP4's known substrates prostaglandin E(2), leukotriene B(4) and D(4), or cyclic nucleotides (all previously implicated in DC migration) could not restore migration. This notwithstanding, our data show that MRP4 is an important protein, significantly contributing to human DC migration toward the draining lymph nodes, and therefore relevant for the initiation of an immune response and a possible target for immunotherapy.

  20. The effects of T-cell conditioned media on the induction of dendritic cell (DC1 maturation for effective tumor immunotherapy

    Directory of Open Access Journals (Sweden)

    Asadi M

    2011-04-01

    Full Text Available "n 800x600 Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Background: Nowadays, dendritic cells (DC are used for tumor immunotherapy as they can induce immune responses against tumor cells. In this research, we comprehensively studied the maturation stimulus addition, PHA-activated T-cell (PHA-TCM conditioned medium, autologous monocyte-conditioned medium (MCM and TNF-α for their ability to promote uniformly mature dendritic cells that elicit T-cell responses."n"nMethods: Plastic adherent monocytes were cultured with granulocyte-macrophage colony stimulating factor (GM-CSF and interleukin-4 (IL-4 for five days and two days with monocyte-conditioned medium (MCM, tumor necrotizing factor-α (TNF-α without TCM (PHA-activated T-cell conditioned medium. Phenotypic and functional analyses were carried out using anti-CD14, anti-CD80, anti-CD86, anti-CD83 monoclonal antibodies. Phagocytic activity, mixed lymphocyte reaction (MLR and cytokine production were also evaluated."n"nResults: The generated dendritic cells had high expression of surface molecules i.e. CD80, CD83, CD86 and HLA-DR. Moreover, the cells had low phagocytic and high T-lymphocyte stimulating activities. Measurement of the produced cytokines showed the generation of type-1 dendritic cells (DC1 in the study."n"nConclusion: The findings indicated that more efficient maturation of dendritic cells could be achieved by the use of PHA-activated T-lymphocyte conditioned medium in the culture medium. The aforesaid supernatant can be used as a maturation factor for the production of efficient

  1. The human airway epithelial basal cell transcriptome.

    Directory of Open Access Journals (Sweden)

    Neil R Hackett

    Full Text Available BACKGROUND: The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem/progenitor cells for the other airway cell types. The objective of this study is to better understand human airway epithelial basal cell biology by defining the gene expression signature of this cell population. METHODOLOGY/PRINCIPAL FINDINGS: Bronchial brushing was used to obtain airway epithelium from healthy nonsmokers. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium in comparison to the transcriptome of the differentiated airway epithelium. This analysis identified the "human airway basal cell signature" as 1,161 unique genes with >5-fold higher expression level in basal cells compared to differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The basal cell signature displayed overlap with genes expressed in basal-like cells from other human tissues and with that of murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the human airway basal cell signature was characterized by genes encoding extracellular matrix components, growth factors and growth factor receptors, including genes related to the EGF and VEGF pathways. Interestingly, while the basal cell signature overlaps that of basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. CONCLUSION/SIGNIFICANCE: The human airway epithelial basal cell signature identified in the present study provides novel insights into the molecular phenotype and biology of

  2. Influence of organophosphate poisoning on human dendritic cells.

    Science.gov (United States)

    Schäfer, Marina; Koppe, Franziska; Stenger, Bernhard; Brochhausen, Christoph; Schmidt, Annette; Steinritz, Dirk; Thiermann, Horst; Kirkpatrick, Charles James; Pohl, Christine

    2013-12-05

    Organophosphourus compounds (OPC, including nerve agents and pesticides) exhibit acute toxicity by inhibition of acetylcholinesterase. Lung affections are frequent complications and a risk factor for death. In addition, epidemiological studies reported immunological alterations after OPC exposure. In our experiments we investigated the effects of organophosphourus pesticides dimethoate and chlorpyrifos on dendritic cells (DC) that are essential for the initial immune response, especially in the pulmonary system. DC, differentiated from the monocyte cell line THP-1 by using various cytokines (IL-4, GM-CSF, TNF-α, Ionomycin), were exposed to organophosphourus compounds at different concentrations for a 24h time period. DC were characterized by flow cytometry and immunofluorescence using typical dendritic cell markers (e.g., CD11c, CD209 and CD83). After OPC exposure we investigated cell death, the secretion profile of inflammatory mediators, changes of DC morphology, and the effect on protein kinase signalling pathways. Our results revealed a successful differentiation of THP-1 into DC. OPC exposure caused a significant concentration-dependent influence on DC: Dendrites of the DC were shortened and damaged, DC-specific cell surface markers (i.e., CD83and CD209) decreased dramatically after chlorpyrifos exposure. Interestingly, the effects caused by dimethoate were in general less pronounced. The organophosphourus compounds affected the release of inflammatory cytokines, such as IL-1ß and IL-8. The anti-inflammatory cytokine IL-10 was significantly down regulated. Protein kinases like the Akt family or ERK, which are essential for cell survival and proliferation, were inhibited by both OPC. These findings indicate that the tested organophosphourus compounds induced significant changes in cell morphology, inhibited anti-inflammatory cytokines and influenced important protein signalling pathways which are involved in regulation of apoptosis. Thus our results highlight

  3. Endocannabinoids and Human Sperm Cells

    Directory of Open Access Journals (Sweden)

    Giovanna Zolese

    2010-10-01

    Full Text Available N-acylethanolamides (NAEs are naturally occurring signaling lipids consisting of amides and esters of long-chain polyunsaturated fatty acids. Usually they are present in a very small amounts in many mammalian tissues and cells, including human reproductive tracts and fluids. Recently, the presence of N-arachidonoylethanolamide (anandamide, AEA, the most characterised member of endocannabinoids, and its congeners palmitoylethanolamide (PEA and oleylethanolamide (OEA in seminal plasma, oviductal fluid, and follicular fluids was demonstrated. AEA has been shown to bind not only type-1 (CB1 and type-2 (CB2 cannabinoid receptors, but also type-1 vanilloid receptor (TRPV1, while PEA and OEA are inactive with respect to classical cannabinoid CB1 and CB2 but activate TRPV1 or peroxisome proliferator activate receptors (PPARs. This review concerns the most recent experimental data on PEA and OEA, endocannabinoid-like molecules which appear to exert their action exclusively on sperm cells with altered features, such as membrane characteristics and kinematic parameters. Their beneficial effects on these cells could suggest a possible pharmacological use of PEA and OEA on patients affected by some forms of idiopathic infertility.

  4. Adaptable DC offset correction

    Science.gov (United States)

    Golusky, John M. (Inventor); Muldoon, Kelly P. (Inventor)

    2009-01-01

    Methods and systems for adaptable DC offset correction are provided. An exemplary adaptable DC offset correction system evaluates an incoming baseband signal to determine an appropriate DC offset removal scheme; removes a DC offset from the incoming baseband signal based on the appropriate DC offset scheme in response to the evaluated incoming baseband signal; and outputs a reduced DC baseband signal in response to the DC offset removed from the incoming baseband signal.

  5. In vitro culture and characterization of human umbilical cord blood-derived plasmacytoid dendritic cell subsets

    Directory of Open Access Journals (Sweden)

    PENG Jianping

    2015-11-01

    Full Text Available ObjectiveTo establish a method for in vitro culture of plasmacytoid dendritic cell (pDC. MethodsUmbilical cord blood (40 ml was collected from healthy parturients in the First Affiliated Hospital of Hunan University of Chinese Medicine, and cord blood mononuclear cell (CBMC were isolated. The CBMC were cultured for 7 days with RPMI 1640 complete medium containing rh Flt3-ligand (Flt3-L (100 ng/ml and rh interleukin (IL-3 (10 ng/ml, and the medium was half changed every 2 days. On the eighth day, CpG ODN (2 μg/ml was added to the cells, and the attached cells and supernatant were collected 24 h later for flow cytometry and interferon (IFNα measurement, respectively. On days 1, 3, 5, 7, and 8 of cell culture, the morphological changes of pDC were observed. Results After 2 h of culture, the CBMC showed circular, flat morphology. Twenty-four hours later, the cells began to adhere to the wall, with extended cytoplasm and increased volumes, and they became round and translucent, with scattered small colonies. On days 3-4 of culture, the cell volume continued increasing; most cells were round, and some had small protrusions; few cells were spindle-, tadpole-, star- or irregularly shaped; the number and volumes of colonies increased substantially. On days 5-8 of culture, the number of colonies and the number of cells in colonies gradually decreased, and suspended cells that were round or had small protrusions gradually increased in the medium. The cells expressing CD123, BDCA-2, and BDCA-4, which were considered pDC, were detected by flow cytometry. Flow cytometry revealed that the proportion of pDC in CBMC increased during the culture: increasing from 1.08% at the beginning of culture to 5.32% on day 4, and finally reaching a peak of 19.8% on day 8. On day 8, the level of IFNα in pDC culture supernatant was(11 302.61±1745.31 pg/ml. ConclusionpDC can be successfully induced in vitro by rh Flt3-L combined with IL-3 from human umbilical CBMC.

  6. Cytotoxic effect of Argentine medicinal plant extracts on human hepatocellular carcinoma cell line.

    Science.gov (United States)

    Ruffa, M J; Ferraro, G; Wagner, M L; Calcagno, M L; Campos, R H; Cavallaro, L

    2002-03-01

    Methanolic extracts from Achyrocline satureioides (Dc.) Lam, Aristolochia macroura Gomez, Lithraea molleoides (Vell.) Engl., Schinus molle L., unlike those from Celtis spinosa Spreng, Chenopodium ambrosioides L., Petiveria alliacea L., and Plantago major L. showed cytotoxic activity against a human hepatocellular carcinoma cell line, Hep G2. Schinus molle L. was the most active (IC50=50+/-7 microg/ml). These results call for further studies of these extracts.

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

    Science.gov (United States)

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

    2017-07-01

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

  8. Characterization of Yellow Fever Virus Infection of Human and Non-human Primate Antigen Presenting Cells and Their Interaction with CD4+ T Cells.

    Directory of Open Access Journals (Sweden)

    Yu Cong

    2016-05-01

    Full Text Available Humans infected with yellow fever virus (YFV, a mosquito-borne flavivirus, can develop illness ranging from a mild febrile disease to hemorrhagic fever and death. The 17D vaccine strain of YFV was developed in the 1930s, has been used continuously since development and has proven very effective. Genetic differences between vaccine and wild-type viruses are few, yet viral or host mechanisms associated with protection or disease are not fully understood. Over the past 20 years, a number of cases of vaccine-associated disease have been identified following vaccination with 17D; these cases have been correlated with reduced immune status at the time of vaccination. Recently, several studies have evaluated T cell responses to vaccination in both humans and non-human primates, but none have evaluated the response to wild-type virus infection. In the studies described here, monocyte-derived macrophages (MDM and dendritic cells (MoDC from both humans and rhesus macaques were evaluated for their ability to support infection with either wild-type Asibi virus or the 17D vaccine strain and the host cytokine and chemokine response characterized. Human MoDC and MDM were also evaluated for their ability to stimulate CD4+ T cells. It was found that MoDC and MDM supported viral replication and that there were differential cytokine responses to infection with either wild-type or vaccine viruses. Additionally, MoDCs infected with live 17D virus were able to stimulate IFN-γ and IL-2 production in CD4+ T cells, while cells infected with Asibi virus were not. These data demonstrate that wild-type and vaccine YFV stimulate different responses in target antigen presenting cells and that wild-type YFV can inhibit MoDC activation of CD4+ T cells, a critical component in development of protective immunity. These data provide initial, but critical insight into regulatory capabilities of wild-type YFV in development of disease.

  9. Characterization of Yellow Fever Virus Infection of Human and Non-human Primate Antigen Presenting Cells and Their Interaction with CD4+ T Cells.

    Science.gov (United States)

    Cong, Yu; McArthur, Monica A; Cohen, Melanie; Jahrling, Peter B; Janosko, Krisztina B; Josleyn, Nicole; Kang, Kai; Zhang, Tengfei; Holbrook, Michael R

    2016-05-01

    Humans infected with yellow fever virus (YFV), a mosquito-borne flavivirus, can develop illness ranging from a mild febrile disease to hemorrhagic fever and death. The 17D vaccine strain of YFV was developed in the 1930s, has been used continuously since development and has proven very effective. Genetic differences between vaccine and wild-type viruses are few, yet viral or host mechanisms associated with protection or disease are not fully understood. Over the past 20 years, a number of cases of vaccine-associated disease have been identified following vaccination with 17D; these cases have been correlated with reduced immune status at the time of vaccination. Recently, several studies have evaluated T cell responses to vaccination in both humans and non-human primates, but none have evaluated the response to wild-type virus infection. In the studies described here, monocyte-derived macrophages (MDM) and dendritic cells (MoDC) from both humans and rhesus macaques were evaluated for their ability to support infection with either wild-type Asibi virus or the 17D vaccine strain and the host cytokine and chemokine response characterized. Human MoDC and MDM were also evaluated for their ability to stimulate CD4+ T cells. It was found that MoDC and MDM supported viral replication and that there were differential cytokine responses to infection with either wild-type or vaccine viruses. Additionally, MoDCs infected with live 17D virus were able to stimulate IFN-γ and IL-2 production in CD4+ T cells, while cells infected with Asibi virus were not. These data demonstrate that wild-type and vaccine YFV stimulate different responses in target antigen presenting cells and that wild-type YFV can inhibit MoDC activation of CD4+ T cells, a critical component in development of protective immunity. These data provide initial, but critical insight into regulatory capabilities of wild-type YFV in development of disease.

  10. Effect of Reishi polysaccharides on human stem/progenitor cells.

    Science.gov (United States)

    Chen, Wan-Yu; Yang, Wen-Bin; Wong, Chi-Huey; Shih, Daniel Tzu-Bi

    2010-12-15

    The polysaccharide fraction of Ganoderma lucidum (F3) was found to benefit our health in many ways by influencing the activity of tissue stem/progenitor cells. In this study, F3 was found to promote the adipose tissue MSCs' aggregation and chondrosphere formation, with the increase of CAM (N-CAM, I-CAM) expressions and autokine (BMP-2, IL-11, and aggrecan) secretions, in an in vitro chondrogenesis assay. In a stem cell expansion culture, it possesses the thrombopoietin (TPO) and GM-CSF like functions to enhance the survival/renewal abilities of primitive hematopoietic stem/progenitor cells (HSCs). F3 was found to promote the dendrite growth of blood mononuclear cells (MNCs) and the expression of cell adhesion molecules in the formation of immature dendritic cells (DC). On the other hand, F3 exhibited inhibitory effects on blood endothelial progenitor (EPC) colony formation, with concomitant reduction of cell surface endoglin (CD105) and vascular endothelial growth factor receptor-3 (VEGFR-3) marker expressions, in the presence of angiogenic factors. A further cytokine array analysis revealed that F3 indeed inhibited the angiogenin synthesis and enhanced IL-1, MCP-1, MIP-1, RANTES, and GRO productions in the blood EPC derivation culture. Collectively, we have demonstrated that the polysaccharide fraction of G. lucidum F3 exhibits cytokine and chemokine like functions which are beneficial to human tissue stem/progenitor cells by modulating their CAM expressions and biological activities. These findings provide us a better the observation that F3 glycopolysaccharides indeed possesses anti-angiogenic and immune-modulating functions and promotes hematopoietic stem/progenitor cell homing for better human tissue protection, reducing disease progression and health.

  11. Satellite cells in human skeletal muscle plasticity.

    Science.gov (United States)

    Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

    2015-01-01

    Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

  12. Development of a new protocol for 2-day generation of mature dendritic cells from human monocytes.

    Science.gov (United States)

    Obermaier, Bianca; Dauer, Marc; Herten, Jan; Schad, Katharina; Endres, Stefan; Eigler, Andreas

    2003-01-01

    We developed a new 2-day protocol for the generation of dendritic cells (DCs) from human monocytes in vitro. First, we demonstrated that 24 hours of culture with GM-CSF and IL-4 are sufficient to generate immature DCs capable of antigen uptake. We then compared two different strategies for DC maturation: proinflammatory mediators were either added together with GM-CSF and IL-4 from the beginning of cell culture or added after 24 hours of differentiation with GM-CSF and IL-4. After 48 hours of total culture period, expression of activation markers was more pronounced in cells generated by the 2-step differentiation and activation method. Our new protocol for 2-day DC differentiation reduces labor, cost and time and also reliably renders high numbers of mature and viable DCs.

  13. Development of a new protocol for 2-day generation of mature dendritic cells from human monocytes

    Directory of Open Access Journals (Sweden)

    Obermaier Bianca

    2003-01-01

    Full Text Available We developed a new 2-day protocol for the generation of dendritic cells (DCs from human monocytes in vitro. First, we demonstrated that 24 hours of culture with GM-CSF and IL-4 are sufficient to generate immature DCs capable of antigen uptake. We then compared two different strategies for DC maturation: proinflammatory mediators were either added together with GM-CSF and IL-4 from the beginning of cell culture or added after 24 hours of differentiation with GM-CSF and IL-4. After 48 hours of total culture period, expression of activation markers was more pronounced in cells generated by the 2-step differentiation and activation method. Our new protocol for 2-day DC differentiation reduces labor, cost and time and also reliably renders high numbers of mature and viable DCs.

  14. Salvianolic acid B suppresses maturation of human monocyte-derived dendritic cells by activating PPARγ

    Science.gov (United States)

    Sun, Aijun; Liu, Hongying; Wang, Shijun; Shi, Dazhuo; Xu, Lei; Cheng, Yong; Wang, Keqiang; Chen, Keji; Zou, Yunzeng; Ge, Junbo

    2011-01-01

    BACKGROUND AND PURPOSE Salvianolic acid B (Sal B), a water-soluble antioxidant derived from a Chinese medicinal herb, is known to be effective in the prevention of atherosclerosis. Here, we tested the hypothesis that the anti-atherosclerotic effect of Sal B might be mediated by suppressing maturation of human monocyte-derived dendritic cells (h-monDC). EXPERIMENTAL APPROACH h-monDC were derived by incubating purified human monocytes with GM-CSF and IL-4. h-monDC were pre-incubated with or without Sal B and stimulated by oxidized low-density lipoprotein (ox-LDL) in the presence or absence of PPARγ siRNA. Expression of h-monDC membrane molecules (CD40, CD86, CD1a, HLA-DR) were analysed by FACS, cytokines were measured by elisa and the TLR4-associated signalling pathway was determined by Western blotting. KEY RESULTS Ox-LDL promoted h-monDC maturation, stimulated CD40, CD86, CD1a, HLA-DR expression and IL-12, IL-10, TNF-α production; and up-regulated TLR4 signalling. These effects were inhibited by Sal B. Sal B also triggered PPARγ activation and promoted PPARγ nuclear translocation, attenuated ox-LDL-induced up-regulation of TLR4 and myeloid differentiation primary-response protein 88 and inhibited the downstream p38-MAPK signalling cascade. Knocking down PPARγ with the corresponding siRNA blocked these effects of Sal B. CONCLUSIONS AND IMPLICATIONS Our data suggested that Sal B effectively suppressed maturation of h-monDC induced by ox-LDL through PPARγ activation. PMID:21649636

  15. Maturation of human dendritic cells by monocyte-conditioned medium is dependent upon trace amounts of lipopolysaccharide inducing tumour necrosis factor alpha

    DEFF Research Database (Denmark)

    Nersting, Jacob; Svenson, Morten; Andersen, Vagn

    2003-01-01

    We investigated the ability of monocyte-conditioned medium (MCM), generated by monocytes cultured on plastic-immobilised immunoglobulin, to stimulate maturation of human monocyte-derived dendritic cells (DC). Earlier reports suggest that MCM is a strong inducer of irreversible DC maturation......-stimulatory potency of LPS. Maturation by this procedure is mediated mainly by tumour necrosis factor alpha secreted from monocytes during the medium-conditioning period....

  16. IMMUNORESPONSES OF HUMANIZED SCID MICE TO HUMAN LUNG CANCER CELLS

    Institute of Scientific and Technical Information of China (English)

    陈力真; 王树蕙; 张云; 王世真

    1996-01-01

    HuPBL-SCID mice were used to explore how they would response to human ttmoor cells of 801/MLC.Living 801/MLC cells appeared to be fetal to the the mice due to the production of human TNF. The huP-BL-SCID rniee did not generate any noticeable amotmt of specific human immunoglobttlin either by single immunization with living 801/MLC cells or by repeated immunization with irradiated 801/MLC cells. Our preliminary experiments with huPBL-SCID mice showed that such chimeras would he a very useful models for tumor immunological researches.

  17. Search for naive human pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Simone Aparecida Siqueira Fonseca; Roberta Montero Costas; Lygia Veiga Pereira

    2015-01-01

    Normal mouse pluripotent stem cells were originallyderived from the inner cell mass (ICM) of blastocystsand shown to be the in vitro equivalent of those preimplantationembryonic cells, and thus were calledembryonic stem cells (ESCs). More than a decade later,pluripotent cells were isolated from the ICM of humanblastocysts. Despite being called human ESCs, thesecells differ significantly from mouse ESCs, includingdifferent morphology and mechanisms of control ofpluripotency, suggesting distinct embryonic originsof ESCs from the two species. Subsequently, mousepluripotent stem cells were established from the ICMderivedepiblast of post-implantation embryos. Thesemouse epiblast stem cells (EpiSCs) are morphologicaland epigenetically more similar to human ESCs. Thisraised the question of whether cells from the humanICM are in a more advanced differentiation stage thantheir murine counterpart, or whether the availableculture conditions were not adequate to maintain thosehuman cells in their in vivo state, leading to a transitioninto EpiSC-like cells in vitro . More recently, novel cultureconditions allowed the conversion of human ESCs intomouse ESC-like cells called naive (or ground state)human ESCs, and the derivation of naive human ESCsfrom blastocysts. Here we will review the characteristicsof each type of pluripotent stem cells, how (andwhether) these relate to different stages of embryonicdevelopment, and discuss the potential implications ofnaive human ESCs in research and therapy.

  18. Akt and SHP-1 are DC-intrinsic checkpoints for tumor immunity

    Science.gov (United States)

    Prestwood, Tyler R.; Spitzer, Matthew H.; Linde, Ian L.; Chabon, Jonathan; Reticker-Flynn, Nathan E.; Bhattacharya, Nupur; Zhang, Hong; Zhang, Xiangyue; Basto, Pamela A.; Burt, Bryan M.; Alonso, Michael N.; Engleman, Edgar G.

    2016-01-01

    BM-derived DC (BMDC) are powerful antigen-presenting cells. When loaded with immune complexes (IC), consisting of tumor antigens bound to antitumor antibody, BMDC induce powerful antitumor immunity in mice. However, attempts to employ this strategy clinically with either tumor-associated DC (TADC) or monocyte-derived DC (MoDC) have been disappointing. To investigate the basis for this phenomenon, we compared the response of BMDC, TADC, and MoDC to tumor IgG-IC. Our findings revealed, in both mice and humans, that upon exposure to IgG-IC, BMDC internalized the IC, increased costimulatory molecule expression, and stimulated autologous T cells. In contrast, TADC and, surprisingly, MoDC remained inert upon contact with IC due to dysfunctional signaling following engagement of Fcγ receptors. Such dysfunction is associated with elevated levels of the Src homology region 2 domain–containing phosphatase-1 (SHP-1) and phosphatases regulating Akt activation. Indeed, concomitant inhibition of both SHP-1 and phosphatases that regulate Akt activation conferred upon TADC and MoDC the capacity to take up and process IC and induce antitumor immunity in vivo. This work identifies the molecular checkpoints that govern activation of MoDC and TADC and their capacity to elicit T cell immunity. PMID:27812544

  19. Influence of infection of murine chemokine receptor-7 recombinant lentivirus on the immunogenicity and migration of DC 2.4 cells%小鼠趋化因子受体7重组慢病毒感染对DC2.4细胞免疫原性和迁移功能的影响

    Institute of Scientific and Technical Information of China (English)

    董志伟; 彭毅志; 张帅; 陈渝; 董凤娟

    2013-01-01

    observe the influence of infection of murine chemokine receptor-7 recombinant lentivirus on the immunogenicity and migration of dendritic cell strain DC 2.4 cells.Methods DC 2.4 cells were routinely cultured.Lentiviruses carrying GFP and those with up-regulated CCR7 were constructed.DC 2.4 cells were divided into DC 2.4 group (without any treatment),GFP-DC 2.4 group (infected with GFP-carrying lentivirus),and CCR7-DC 2.4 group (infected with CCR7-carrying lentivirus labeled by GFP) according to the random number table.The expressions of surface molecules MHC Ⅱ,CD80,CD86,and CCR7 were detected by flow cytometry,Western blotting,and confocal laser scanning microscope.The migration of cells was detected by chemotaxis assay in vitro.The immunogenicity of cells was detected with mixed lymphocyte reaction.LPS-DC 2.4 group was set up as positive control.Data were processed with one-way analysis of variance and t test.Results Lentiviruses carrying stably-expressing CCR7 were constructed,and the transfection rate of which into DC 2.4 cells was 87.4%.There was no statistically significant difference among DC 2.4,GFP-DC 2.4,and CCR7-DC 2.4 groups in the expressions of MHC Ⅱ,CD80,and CD86 as showed by flow cytometry (with F values from 0.17 to 1.19,P values all above 0.05).The protein expression of CCR7 of cells in CCR7-DC 2.4 group (45.1 ± 2.1) was obviously higher than that in DC 2.4 and GFP-DC 2.4 groups (25.3 ± 1.4,28.6 ± 0.9,F =162.90,P < 0.01),while the difference of which between DC 2.4 group and GFP-DC 2.4 group was not statistically significant (t =2.20,P > 0.05).The fluorescence intensity of CCR7 in CCR7-DC 2.4 group was obviously increased compared with that of DC 2.4 group.The chemotaxic migration rate of cells in CCR7-DC 2.4 group with the influence of CCL19 was (41.0 ± 2.0) %,which was significantly higher than that of DC 2.4 and GFP-DC 2.4 groups [(6.0 ± 0.5) %,(6.8 ± 0.3) %,F =84.21,P < 0.01].There was no statistically significant difference

  20. Endothelial cells derived from human embryonic stem cells

    Science.gov (United States)

    Levenberg, Shulamit; Golub, Justin S.; Amit, Michal; Itskovitz-Eldor, Joseph; Langer, Robert

    2002-04-01

    Human embryonic stem cells have the potential to differentiate into various cell types and, thus, may be useful as a source of cells for transplantation or tissue engineering. We describe here the differentiation steps of human embryonic stem cells into endothelial cells forming vascular-like structures. The human embryonic-derived endothelial cells were isolated by using platelet endothelial cell-adhesion molecule-1 (PECAM1) antibodies, their behavior was characterized in vitro and in vivo, and their potential in tissue engineering was examined. We show that the isolated embryonic PECAM1+ cells, grown in culture, display characteristics similar to vessel endothelium. The cells express endothelial cell markers in a pattern similar to human umbilical vein endothelial cells, their junctions are correctly organized, and they have high metabolism of acetylated low-density lipoprotein. In addition, the cells are able to differentiate and form tube-like structures when cultured on matrigel. In vivo, when transplanted into SCID mice, the cells appeared to form microvessels containing mouse blood cells. With further studies, these cells could provide a source of human endothelial cells that could be beneficial for potential applications such as engineering new blood vessels, endothelial cell transplantation into the heart for myocardial regeneration, and induction of angiogenesis for treatment of regional ischemia.

  1. Increased tubulointerstitial recruitment of human CD141(hi) CLEC9A(+) and CD1c(+) myeloid dendritic cell subsets in renal fibrosis and chronic kidney disease.

    Science.gov (United States)

    Kassianos, Andrew J; Wang, Xiangju; Sampangi, Sandeep; Muczynski, Kimberly; Healy, Helen; Wilkinson, Ray

    2013-11-15

    Dendritic cells (DCs) play critical roles in immune-mediated kidney diseases. Little is known, however, about DC subsets in human chronic kidney disease, with previous studies restricted to a limited set of pathologies and to using immunohistochemical methods. In this study, we developed novel protocols for extracting renal DC subsets from diseased human kidneys and identified, enumerated, and phenotyped them by multicolor flow cytometry. We detected significantly greater numbers of total DCs as well as CD141(hi) and CD1c(+) myeloid DC (mDCs) subsets in diseased biopsies with interstitial fibrosis than diseased biopsies without fibrosis or healthy kidney tissue. In contrast, plasmacytoid DC numbers were significantly higher in the fibrotic group compared with healthy tissue only. Numbers of all DC subsets correlated with loss of kidney function, recorded as estimated glomerular filtration rate. CD141(hi) DCs expressed C-type lectin domain family 9 member A (CLEC9A), whereas the majority of CD1c(+) DCs lacked the expression of CD1a and DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), suggesting these mDC subsets may be circulating CD141(hi) and CD1c(+) blood DCs infiltrating kidney tissue. Our analysis revealed CLEC9A(+) and CD1c(+) cells were restricted to the tubulointerstitium. Notably, DC expression of the costimulatory and maturation molecule CD86 was significantly increased in both diseased cohorts compared with healthy tissue. Transforming growth factor-β levels in dissociated tissue supernatants were significantly elevated in diseased biopsies with fibrosis compared with nonfibrotic biopsies, with mDCs identified as a major source of this profibrotic cytokine. Collectively, our data indicate that activated mDC subsets, likely recruited into the tubulointerstitium, are positioned to play a role in the development of fibrosis and, thus, progression to chronic kidney disease.

  2. Induced pluripotent stem cell lines derived from human somatic cells.

    Science.gov (United States)

    Yu, Junying; Vodyanik, Maxim A; Smuga-Otto, Kim; Antosiewicz-Bourget, Jessica; Frane, Jennifer L; Tian, Shulan; Nie, Jeff; Jonsdottir, Gudrun A; Ruotti, Victor; Stewart, Ron; Slukvin, Igor I; Thomson, James A

    2007-12-21

    Somatic cell nuclear transfer allows trans-acting factors present in the mammalian oocyte to reprogram somatic cell nuclei to an undifferentiated state. We show that four factors (OCT4, SOX2, NANOG, and LIN28) are sufficient to reprogram human somatic cells to pluripotent stem cells that exhibit the essential characteristics of embryonic stem (ES) cells. These induced pluripotent human stem cells have normal karyotypes, express telomerase activity, express cell surface markers and genes that characterize human ES cells, and maintain the developmental potential to differentiate into advanced derivatives of all three primary germ layers. Such induced pluripotent human cell lines should be useful in the production of new disease models and in drug development, as well as for applications in transplantation medicine, once technical limitations (for example, mutation through viral integration) are eliminated.

  3. Priming of Salmonella enterica serovar typhi-specific CD8(+ T cells by suicide dendritic cell cross-presentation in humans.

    Directory of Open Access Journals (Sweden)

    Rosângela Salerno-Goncalves

    Full Text Available BACKGROUND: The emergence of antibiotic-resistant strains of Salmonella enterica serovar Typhi (S. Typhi, the etiologic agent of typhoid fever, has aggravated an already important public health problem and added new urgency to the development of more effective typhoid vaccines. To this end it is critical to better understand the induction of immunity to S. Typhi. CD8(+ T cells are likely to play an important role in host defense against S. Typhi by several effector mechanisms, including killing of infected cells and IFN-gamma secretion. However, how S. Typhi regulates the development of specific CD8(+ responses in humans remains unclear. Recent studies in mice have shown that dendritic cells (DC can either directly (upon uptake and processing of Salmonella or indirectly (by bystander mechanisms elicit Salmonella-specific CD8(+ T cells. METHODOLOGY/PRINCIPAL FINDINGS: We report here that upon infection with live S. Typhi, human DC produced high levels of pro-inflammatory cytokines IL-6, IL-8 and TNF-alpha, but low levels of IL-12 p70 and IFN-gamma. In contrast, DC co-cultured with S. Typhi-infected cells, through suicide cross-presentation, uptake S. Typhi-infected human cells and release high levels of IFN-gamma and IL-12p70, leading to the subsequent presentation of bacterial antigens and triggering the induction of memory T cells, mostly CD3(+CD8(+CD45RA(-CD62L(- effector/memory T cells. CONCLUSIONS/SIGNIFICANCE: This study is the first to demonstrate the effect of S. Typhi on human DC maturation and on their ability to prime CD8(+ cells and highlights the significance of these phenomena in eliciting adaptive immunity to S. Typhi.

  4. Far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge triple-junction solar cell under forward DC bias

    Institute of Scientific and Technical Information of China (English)

    Xiao Wenbo; He Xingdao; Gao Yiqing; Zhang Zhimin; Liu Jiangtao

    2012-01-01

    The far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge solar cell are investigated under forward DC bias at room temperature in dark conditions.An electroluminescence viewgraph shows the clear device structures,and the electroluminescence intensity is shown to increases exponentially with bias voltage and linearly with bias current.The results can be interpreted using an equivalent circuit of a single ideal diode model for triple-junction solar cells.The good fit between the measured and calculated data proves the above conclusions.This work is of guiding significance for current solar cell testing and research.

  5. "Forback" Dc-To-Dc Converters

    Science.gov (United States)

    Lukemire, Alan T.

    1992-01-01

    Dc-to-dc power-converter circuits called "forback" resemble circuits of standard configurations called "forward", "flyback", and "Cuk". Circuit employs minor modifications to existing topologies, combines advantages, while eliminating disadvantages, of older circuits.

  6. In vitro generation of dendritic cells from human blood monocytes in experimental conditions compatible for in vivo cell therapy.

    Science.gov (United States)

    Cao, H; Vergé, V; Baron, C; Martinache, C; Leon, A; Scholl, S; Gorin, N C; Salamero, J; Assari, S; Bernard, J; Lopez, M

    2000-04-01

    DC are professional APC that are promising adjuvants for clinical immunotherapy. Methods to generate in vitro large numbers of functional human DC using either peripheral blood monocytes or CD34+ pluripotent HPC have been developed recently. However, the various steps of their in vitro production for further clinical use need to fit good manufacturing practice (GMP) conditions. Our study focused on setting up such a full procedure, including collection of mononuclear cells (MNC) by apheresis, separation of monocytes by elutriation, and culture of monocytes with GM-CSF + IL-13 + autologous serum (SAuto) in sterile Teflon bags. The procedure was first developed with apheresis products from 7 healthy donors. Its clinical feasibility was then tested on 7 patients with breast cancer. The characteristics of monocyte-derived DC grown with SAuto (or in some instances with a pooled AB serum) were compared with those obtained in the presence of FBS by evaluation of their phenotype, their morphology in confocal microscopy, and their capacity to phagocytize latex particles and to stimulate allogeneic (MLR) or autologous lymphocytes (antigen-presentation tests). The results obtained demonstrate that the experimental conditions we set up are easily applicable in clinical trials and lead to large numbers of well-defined SAuto-derived DC as efficient as those derived with FBS.

  7. Multiport Resonant DC-DC Converter

    OpenAIRE

    Tran, Yan-Kim; Dujic, Drazen; Barrade, Philippe

    2015-01-01

    his paper presents a multiport galvanically isolated LLC resonant DC-DC converter suitable for DC applications. A three-port structure is analyzed, with full bidirectional power flow capabilities, simple control and behavior similar to that expected from a DC transformer. Each port is equipped with half-bridge modules accompanied with tuned resonant tank, partly realized with elements of a multi- winding high frequency transformer. With some restrictions that are explained in the paper, each ...

  8. VLSI Hybrid DC-DC Regulator

    OpenAIRE

    Cosp Vilella, Jordi; Martínez García, Herminio

    2015-01-01

    Hybrid DC-DC regulators are structures that combine both a linear voltage regulator and a switching DC-DC converter. The main objective of this hybrid topology is to converge, in a single circuit topology, the best of both alternatives: a small voltage output ripple, which is a common characteristic of linear regulator circuits, and good energy efficiency, as in switching alternatives. While the linear regulator fixes the required output voltage to a fixed value with negligible steady-state r...

  9. Local Bifurcations in DC-DC Converters

    OpenAIRE

    2012-01-01

    Three local bifurcations in DC-DC converters are reviewed. They are period-doubling bifurcation, saddle-node bifurcation, and Neimark bifurcation. A general sampled-data model is employed to study the types of loss of stability of the nominal (periodic) solution and their connection with local bifurcations. More accurate prediction of instability and bifurcation than using the averaging approach is obtained. Examples of bifurcations associated with instabilities in DC-DC converters are given.

  10. Trophoblast lineage cells derived from human induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying, E-mail: ying.chen@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, 333 Bostwick NE, Grand Rapids, MI 49503 (United States); Wang, Kai; Chandramouli, Gadisetti V.R. [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, 333 Bostwick NE, Grand Rapids, MI 49503 (United States); Knott, Jason G. [Developmental Epigenetics Laboratory, Department of Animal Science, Michigan State University (United States); Leach, Richard, E-mail: Richard.leach@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, 333 Bostwick NE, Grand Rapids, MI 49503 (United States); Department of Obstetrics, Gynecology and Women’s Health, Spectrum Health Medical Group (United States)

    2013-07-12

    Highlights: •Epithelial-like phenotype of trophoblast lineage cells derived from human iPS cells. •Trophoblast lineage cells derived from human iPS cells exhibit trophoblast function. •Trophoblasts from iPS cells provides a proof-of-concept in regenerative medicine. -- Abstract: Background: During implantation, the blastocyst trophectoderm attaches to the endometrial epithelium and continues to differentiate into all trophoblast subtypes, which are the major components of a placenta. Aberrant trophoblast proliferation and differentiation are associated with placental diseases. However, due to ethical and practical issues, there is almost no available cell or tissue source to study the molecular mechanism of human trophoblast differentiation, which further becomes a barrier to the study of the pathogenesis of trophoblast-associated diseases of pregnancy. In this study, our goal was to generate a proof-of-concept model for deriving trophoblast lineage cells from induced pluripotency stem (iPS) cells from human fibroblasts. In future studies the generation of trophoblast lineage cells from iPS cells established from patient’s placenta will be extremely useful for studying the pathogenesis of individual trophoblast-associated diseases and for drug testing. Methods and results: Combining iPS cell technology with BMP4 induction, we derived trophoblast lineage cells from human iPS cells. The gene expression profile of these trophoblast lineage cells was distinct from fibroblasts and iPS cells. These cells expressed markers of human trophoblasts. Furthermore, when these cells were differentiated they exhibited invasive capacity and placental hormone secretive capacity, suggesting extravillous trophoblasts and syncytiotrophoblasts. Conclusion: Trophoblast lineage cells can be successfully derived from human iPS cells, which provide a proof-of-concept tool to recapitulate pathogenesis of patient placental trophoblasts in vitro.

  11. Guided migration of neural stem cells derived from human embryonic stem cells by an electric field.

    Science.gov (United States)

    Feng, Jun-Feng; Liu, Jing; Zhang, Xiu-Zhen; Zhang, Lei; Jiang, Ji-Yao; Nolta, Jan; Zhao, Min

    2012-02-01

    Small direct current (DC) electric fields (EFs) guide neurite growth and migration of rodent neural stem cells (NSCs). However, this could be species dependent. Therefore, it is critical to investigate how human NSCs (hNSCs) respond to EF before any possible clinical attempt. Aiming to characterize the EF-stimulated and guided migration of hNSCs, we derived hNSCs from a well-established human embryonic stem cell line H9. Small applied DC EFs, as low as 16 mV/mm, induced significant directional migration toward the cathode. Reversal of the field polarity reversed migration of hNSCs. The galvanotactic/electrotactic response was both time and voltage dependent. The migration directedness and distance to the cathode increased with the increase of field strength. (Rho-kinase) inhibitor Y27632 is used to enhance viability of stem cells and has previously been reported to inhibit EF-guided directional migration in induced pluripotent stem cells and neurons. However, its presence did not significantly affect the directionality of hNSC migration in an EF. Cytokine receptor [C-X-C chemokine receptor type 4 (CXCR4)] is important for chemotaxis of NSCs in the brain. The blockage of CXCR4 did not affect the electrotaxis of hNSCs. We conclude that hNSCs respond to a small EF by directional migration. Applied EFs could potentially be further exploited to guide hNSCs to injured sites in the central nervous system to improve the outcome of various diseases.

  12. High-Efficiency dc/dc Converter

    Science.gov (United States)

    Sturman, J.

    1982-01-01

    High-efficiency dc/dc converter has been developed that provides commonly used voltages of plus or minus 12 Volts from an unregulated dc source of from 14 to 40 Volts. Unique features of converter are its high efficiency at low power level and ability to provide output either larger or smaller than input voltage.

  13. Comparative study of clinical grade human tolerogenic dendritic cells

    Directory of Open Access Journals (Sweden)

    Martínez-Cáceres E

    2011-06-01

    Full Text Available Abstract Background The use of tolerogenic DCs is a promising therapeutic strategy for transplantation and autoimmune disorders. Immunomodulatory DCs are primarily generated from monocytes (MDDCs for in vitro experiments following protocols that fail to fulfil the strict regulatory rules of clinically applicable products. Here, we compared the efficacy of three different tolerance-inducing agents, dexamethasone, rapamycin and vitamin D3, on DC biology using GMP (Good Manufacturing Practice or clinical grade reagents with the aim of defining their use for human cell therapy. Methods Tolerogenic MDDCs were generated by adding tolerogenic agents prior to the induction of maturation using TNF-α, IL-β and PGE2. We evaluated the effects of each agent on viability, efficiency of differentiation, phenotype, cytokine secretion and stability, the stimulatory capacity of tol-DCs and the T-cell profiles induced. Results Differences relevant to therapeutic applicability were observed with the cellular products that were obtained. VitD3-induced tol-DCs exhibited a slightly reduced viability and yield compared to Dexa-and Rapa-tol-DCs. Phenotypically, while Dexa-and VitD3-tol-DCs were similar to immature DCs, Rapa-tol-DCs were not distinguishable from mature DCs. In addition, only Dexa-and moderately VitD3-tol-DCs exhibited IL-10 production. Interestingly, in all cases, the cytokine secretion profiles of tol-DCs were not modified by a subsequent TLR stimulation with LPS, indicating that all products had stable phenotypes. Functionally, clearly reduced alloantigen T cell proliferation was induced by tol-DCs obtained using any of these agent. Also, total interferon-gamma (IFN-γ secretion by T cells stimulated with allogeneic tol-DCs was reduced in all three cases, but only T cells co-cultured with Rapa-tol-DCs showed impaired intracellular IFN-γ production. In addition, Rapa-DCs promoted CD4+ CD127 low/negative CD25high and Foxp3+ T cells. Conclusions Our

  14. A Novel High Gain DC-DC Step up Converter

    Directory of Open Access Journals (Sweden)

    M. Al Mamun

    2016-07-01

    Full Text Available High gain dc-dc converters are widely used to maximize the energy harvest for renewable energy systems, for example, photovoltaic systems and fuel cell. Conventional boost converters usually operates at extreme duty cycle to obtain high voltage gain. Operation at extreme duty cycle leads to reverse recovery problem at the switches, high conduction loss, electromagnetic interference etc. This paper proposes a very high gain dc-dc step up converter operating at very low duty cycle (i.e. duty cycle <0.5. The additional advantage of the proposed converter is that a single control signal is used for the switches which reduces the operation complexity. The steady-state theoretical analysis described in this paper is finally verified by simulation results

  15. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-07-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  16. Human Neural Cell-Based Biosensor

    Science.gov (United States)

    2013-05-28

    including incubation with factors such as SHH ) and proceed to Human Neural Progenitor Cells Dopaminergic Differentiation β-III Tubulin/TH...exposure in human embryonic stem cells. J Recept Signal Transduct Res. 2011 Jun;31(3):206-13. Gerwe BA, Angel PM, West FD, Hasneen K, Young A

  17. Brugia malayi Antigen (BmA Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

    Directory of Open Access Journals (Sweden)

    Emily E I M Mouser

    Full Text Available One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA and excretory-secretory product 62 (ES-62 from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs.

  18. Phenotypic and functional characteristics of dendritic cells derived from human peripheral blood monocytes

    Institute of Scientific and Technical Information of China (English)

    TANG Ling-ling; ZHANG Zhe; ZHENG Jie-sheng; SHENG Ji-fang; LIU Ke-zhou

    2005-01-01

    Objective: This study is aimed at developing a simple and easy way to generate dendritic cells (DCs) from human peripheral blood monocytes (PBMCs) in vitro. Methods: PBMCs were isolated directly from white blood cell rather than whole blood and purified by patching methods (collecting the attached cell and removing the suspension cell). DCs were then generated by culturing PBMCs for six days with 30 ng/ml recombinant human granulocyte-macrophage stimulating factor (rhGM-CSF) and 20 ng/ml recombinant human interleukin-4 (rhIL-4) in vitro. On the sixth day, TNF-alpha (TNFα) 30 ng/ml was added into some DC cultures, which were then incubated for two additional days. The morphology was monitored by light microscopy and transmission electronic microscopy, and the phenotypes were determined by flow cytometry. Autologous mixed leukocyte reactions (MLR) were used to characterize DC function after TNFα or lipopolysaccharide (LPS) stimulations for 24 h. Results: After six days of culture, the monocytes developed significant dendritic morphology and a portion of cells expressed CD 1 a, CD80 and CD86, features of DCs. TNFα treatment induced DCs maturation and up-regulation of CD80, CD86 and CD83. Autologous MLR demonstrated that these DCs possess potent T-cell stimulatory capacity. Conclusion: This study developed a simple and easy way to generate DCs from PBMCs exposed to rhGM-CSF and rhIL-4. The DCs produced by this method acquired morphologic and antigenic characteristics of DCs.

  19. Novel Step-Up DC/DC Converter with No Right Half Plane Zero and Reduced Switched Voltage Stress Characteristics

    DEFF Research Database (Denmark)

    Mostaan, Ali; Alizadeh, Ebrahim; Soltani, Mohsen

    2014-01-01

    Novel step-up DC/DC converter is introduced in this paper. This converter is realized with adding the switched capacitor voltage multiplier cell to the three switch step-down DC/DC converter that has been proposed in the literature. The proposed converter is analyzed in the steady state and the v...

  20. Cell-Free versus Cell-to-Cell Infection by Human Immunodeficiency Virus Type 1 and Human T-Lymphotropic Virus Type 1: Exploring the Link among Viral Source, Viral Trafficking, and Viral Replication.

    Science.gov (United States)

    Dutartre, Hélène; Clavière, Mathieu; Journo, Chloé; Mahieux, Renaud

    2016-09-01

    Human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus type 1 (HTLV-1) are complex retroviruses mainly infecting CD4(+) T lymphocytes. In addition, antigen-presenting cells such as dendritic cells (DCs) are targeted in vivo by both viruses, although to a lesser extent. Interaction of HIV-1 with DCs plays a key role in viral dissemination from the mucosa to CD4(+) T lymphocytes present in lymphoid organs. While similar mechanisms may occur for HTLV-1 as well, most HTLV-1 data were obtained from T-cell studies, and little is known regarding the trafficking of this virus in DCs. We first compared the efficiency of cell-free versus cell-associated viral sources of both retroviruses at infecting DCs. We showed that both HIV-1 and HTLV-1 cell-free particles are poorly efficient at productively infecting DCs, except when DC-SIGN has been engaged. Furthermore, while SAMHD-1 accounts for restriction of cell-free HIV-1 infection, it is not involved in HTLV-1 restriction. In addition, cell-free viruses lead mainly to a nonproductive DC infection, leading to trans-infection of T-cells, a process important for HIV-1 spread but not for that of HTLV-1. Finally, we show that T-DC cell-to-cell transfer implies viral trafficking in vesicles that may both increase productive infection of DCs ("cis-infection") and allow viral escape from immune surveillance. Altogether, these observations allowed us to draw a model of HTLV-1 and HIV-1 trafficking in DCs.

  1. The Biomineralization of a Bioactive Glass-Incorporated Light-Curable Pulp Capping Material Using Human Dental Pulp Stem Cells

    Science.gov (United States)

    Jun, Soo-Kyung; Lee, Hae-Hyoung

    2017-01-01

    The aim of this study was to investigate the biomineralization of a newly introduced bioactive glass-incorporated light-curable pulp capping material using human dental pulp stem cells (hDPSCs). The product (Bioactive® [BA]) was compared with a conventional calcium hydroxide-incorporated (Dycal [DC]) and a light-curable (Theracal® [TC]) counterpart. Eluates from set specimens were used for investigating the cytotoxicity and biomineralization ability, determined by alkaline phosphatase (ALP) activity and alizarin red staining (ARS). Cations and hydroxide ions in the extracts were measured. An hDPSC viability of less than 70% was observed with 50% diluted extract in all groups and with 25% diluted extract in the DC. Culturing with 12.5% diluted BA extract statistically lowered ALP activity and biomineralization compared to DC (p 0.05). Ca (~110 ppm) and hydroxide ions (pH 11) were only detected in DC and TC. Ionic supplement-added BA, which contained similar ion concentrations as TC, showed similar ARS mineralization compared to TC. In conclusion, the BA was similar to, yet more cytotoxic to hDPSCs than, its DC and TC. The BA was considered to stimulate biomineralization similar to DC and TC only when it released a similar amount of Ca and hydroxide ions. PMID:28232937

  2. The Biomineralization of a Bioactive Glass-Incorporated Light-Curable Pulp Capping Material Using Human Dental Pulp Stem Cells

    Directory of Open Access Journals (Sweden)

    Soo-Kyung Jun

    2017-01-01

    Full Text Available The aim of this study was to investigate the biomineralization of a newly introduced bioactive glass-incorporated light-curable pulp capping material using human dental pulp stem cells (hDPSCs. The product (Bioactive® [BA] was compared with a conventional calcium hydroxide-incorporated (Dycal [DC] and a light-curable (Theracal® [TC] counterpart. Eluates from set specimens were used for investigating the cytotoxicity and biomineralization ability, determined by alkaline phosphatase (ALP activity and alizarin red staining (ARS. Cations and hydroxide ions in the extracts were measured. An hDPSC viability of less than 70% was observed with 50% diluted extract in all groups and with 25% diluted extract in the DC. Culturing with 12.5% diluted BA extract statistically lowered ALP activity and biomineralization compared to DC (p0.05. Ca (~110 ppm and hydroxide ions (pH 11 were only detected in DC and TC. Ionic supplement-added BA, which contained similar ion concentrations as TC, showed similar ARS mineralization compared to TC. In conclusion, the BA was similar to, yet more cytotoxic to hDPSCs than, its DC and TC. The BA was considered to stimulate biomineralization similar to DC and TC only when it released a similar amount of Ca and hydroxide ions.

  3. Impact of DC-power during Mo back contact sputtering on the alkali distribution in Cu(In,Ga)Se{sub 2}-based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lepetit, T., E-mail: thomas.lepetit@cnrs-imn.fr [Institut des Matériaux Jean Rouxel (IMN), UMR 6502 CNRS, 2 rue de la Houssinière BP 32229, 44322 Nantes Cedex 3 (France); Mangin, D. [Institut Jean Lamour, UMR 7198 CNRS — Université de Lorraine, Parc de Saurupt, CS 50840, 54011 Nancy Cedex (France); Gautron, E.; Tomassini, M.; Harel, S.; Arzel, L.; Barreau, N. [Institut des Matériaux Jean Rouxel (IMN), UMR 6502 CNRS, 2 rue de la Houssinière BP 32229, 44322 Nantes Cedex 3 (France)

    2015-05-01

    DC-sputtered Mo back contact layers were deposited on soda-lime glass (SLG) with different power densities applied on the Mo target to study its influence on the photovoltaic performance of Cu(In,Ga)Se{sub 2}-based (CIGSe) solar cell. CIGSe absorber was then deposited simultaneously on these SLG/Mo, following the 3-stage process. These devices have good but different photovoltaic performance (> 16% efficiency without MgF{sub 2} coating). To find a material origin, secondary ion mass spectroscopy (SIMS) profiles were carried out on complete cells, revealing that Na and K content and distribution in each layer depend on the deposition conditions of the back contact. Even before the CIGSe deposition and despite similar morphologies, Na content can vary 10-fold from one Mo layer to another. The same applies to the absorber; when grown on a different Mo they present the same grain boundary density but different alkali contents in bulk or at interfaces. This has an influence on the compositional grading in absorber, confirmed by X-ray diffraction and SIMS. - Highlights: • Mo films synthesized at different DC-power applied on the target during sputtering. • Similar macroscopic properties of Mo back contacts • The lowest alkali content in absorber with the highest DC-power applied during Mo sputtering.

  4. Cortical network from human embryonic stem cells

    OpenAIRE

    2010-01-01

    Abstract The connection of embryonic stem cell technology and developmental biology provides valuable tools to decipher the mechanisms underlying human brain development and diseases, especially among neuronal populations, that are not readily available in primary cultures. It is obviously the case of neurons forming the human cerebral cortex. In the images that are presented, the neurons were generated in vitro from human embryonic stem cells via forebrain-like progenitors. Maintained in cul...

  5. Differential Protein Pathways in 1,25-Dihydroxyvitamin D-3 and Dexamethasone Modulated Tolerogenic Human Dendritic Cells

    DEFF Research Database (Denmark)

    Ferreira, Gabriela Bomfim; Kleijwegt, Fleur S.; Waelkens, Etienne;

    2012-01-01

    Tolerogenic dendritic cells (DC) that are maturation-resistant and locked in a semimature state are promising tools in clinical applications for tolerance induction. Different immunomodulatory agents have been shown to induce a tolerogenic DC phenotype, such as the biologically active form...... is more potent than DEX in inducing a tolerogenic profile on human DCs. Moreover, we demonstrate that combining 1,25(OH)(2)D-3 with DEX induces a unique protein expression pattern with major imprinting of the 1,25(OH)(2)D-3 effect. Finally, protein interaction networks and pathway analysis suggest that 1...

  6. A novel approach for the generation of human dendritic cells from blood monocytes in the absence of exogenous factors.

    Science.gov (United States)

    Schanen, Brian C; Drake, Donald R

    2008-06-01

    Human dendritic cells (DCs) for research and clinical applications are typically derived from purified blood monocytes that are cultured in a cocktail of cytokines for a week or more. Because it has been suggested that these cytokine-derived DCs may be deficient in some important immunological functions and might not accurately represent antigen presenting cell (APC) populations found under normal conditions in vivo, there is an interest in developing methods that permit the derivation of DCs in a more physiologically relevant manner in vitro. Here, we describe a simple and reliable technique for generating large numbers of highly purified DCs that is based on a one-way migration of blood monocytes through a layer of human umbilical vein endothelial cells (HUVECs) that are cultured to confluency in the upper chamber of a Transwell device. The resultant APCs, harvested from the lower Transwell chamber, resemble other cultured DC populations in their expression of major histocompatibility (MHC) and costimulatory molecules, ability to phagocytose protein antigens and capacity to trigger primary antigen-specific T cell responses. This technique offers several advantages over the standard method of in vitro cytokine-driven DC development, including: (1) the rapidity of this approach, as DC differentiation occurs in only 2 days, (2) the differentiation process itself, which is more akin to the development of DCs under physiologic conditions and (3) the cost-effectiveness of the system, since no monocyte pre-selection is required and DC development occurs in the absence of expensive recombinant cytokines.

  7. U.S. Department of Energy Hydrogen and Fuel Cells Program 2014 Annual Merit Review and Peer Evaluation Report: June 16-20, 2014, Washington, D.C.

    Energy Technology Data Exchange (ETDEWEB)

    2014-10-01

    The fiscal year (FY) 2014 U.S. Department of Energy (DOE) Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting (AMR), in conjunction with DOE's Vehicle Technologies Office AMR, was held from June 16-20, 2014, at the Washington Marriott Wardman Park in Washington, D.C. This report is a summary of comments by AMR peer reviewers about the hydrogen and fuel cell projects funded by DOE's Office of Energy Efficiency and Renewable Energy (EERE).

  8. Intrinsic ZnO films fabricated by DC sputtering from oxygen-deficient targets for Cu(In,Ga)Se2 solar cell application

    Institute of Scientific and Technical Information of China (English)

    Chongyin Yang; DongyunWan; Zhou Wang; Fuqiang Huang

    2011-01-01

    Intrinsic zinc oxide films, normally deposited by radio frequency (RF) sputtering, are fabricated by direct current (DC) sputtering. The oxygen-deficient targets are prepared via a newly developed double crucible method. The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film. This is achieved by the widely used RF sputtering, which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells. The optimal ZnO film is used in a Cu (In, Ga) Se2 (CIGS) solar cell with a high efficiency of 11.57%. This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.%Intrinsic zinc oxide films,normally deposited by radio frequency (RF) sputtering,are fabricated by direct current (DC) sputtering.The oxygen-deficient targets are prepared via a newly developed double crucible method.The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film.This is achieved by the widely used RF sputtering,which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells.The optimal ZnO film is used in a Cu (In,Ga) Se2 (C1GS) solar cell with a high efficiency of 11.57%.This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.High resistance transparent intrinsic zinc oxide (i-ZnO)thin film has been widely nsed as the front electrode in transparent electronics and photovoltaic devices because of its low cost and nontoxicity.Owing to its unique characteristics of high transparency and adjustable resistivity in a certain range,the use of i-ZnO thin films as diffusion barrier layers of a-Si/μc-Si,CdTe,and CIGS thin-film solar cells has been advantageous

  9. Human monocyte-derived dendritic cells expressing both chemotactic cytokines IL-8, MCP-1, RANTES and their receptors,and their selective migration to these chemokines

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To characterize the mRNA expression of CXC chemokine IL-8, CC chemokine monocyte chemothractant protein-1 (MCP-1) and regulated on activation,normal T cell expressed and secreted (RANTES), and a newly defined DC chemokine DC- CK1 as well as the expression of IL-8 receptor, MCP-1 receptor and RANTES receptor in human monocyte derived dendritic cells (MoDCs).The migratory responsiveness of MoDC to IL-8, MCP-1 and RANTES was alsso studied. Methods In vitro generated MoDCs were obtained by differentiating monocytes in the presence of GM-CSF and IL-4 for 5 days. The time course of RNA expression was analyzed by RT-PCR and migratoly ability was assessed by a micromultiwell chemotaxis chamber assay. Results IL-8, MCP-1, RANTES and their corres ponding receptors were consistently expressed in MoDCs. DC-CK-1 expression was detectable efter 48 hours of differentiation. MoDC selectively migrated in response to MCP-1 and RANTES but not to IL-8 though transcripts of IL-8 receptor were present. Conclusion Because the capacity of dendritic cells to initiate immune responses depends on their specialized migratory and tissue homing properties, the expression of chemokines and their receptors along with the migratory responsiveness to chemokines of MoDC in our study suggests a potential role of chemokines in the interaction between dendritic cells and T cells and the induction of immune responses.

  10. Dendritic Cells Enhance HIV Infection of Memory CD4(+) T Cells in Human Lymphoid Tissues.

    Science.gov (United States)

    Reyes-Rodriguez, Angel L; Reuter, Morgan A; McDonald, David

    2016-02-01

    Dendritic cells (DCs) play a key role in controlling infections by coordinating innate and adaptive immune responses to invading pathogens. Paradoxically, DCs can increase HIV-1 dissemination in vitro by binding and transferring infectious virions to CD4(+) T cells, a process called transinfection. Transinfection has been well characterized in cultured cell lines and circulating primary T cells, but it is unknown whether DCs enhance infection of CD4(+) T cells in vivo. In untreated HIV infection, massive CD4(+) T-cell infection and depletion occur in secondary lymphoid tissues long before decline is evident in the peripheral circulation. To study the role of DCs in HIV infection of lymphoid tissues, we utilized human tonsil tissues, cultured either as tissue blocks or as aggregate suspension cultures, in single-round infection experiments. In these experiments, addition of monocyte-derived DCs (MDDCs) to the cultures increased T-cell infection, particularly in CD4(+) T cells expressing lower levels of HLA-DR. Subset analysis demonstrated that MDDCs increased HIV-1 infection of central and effector memory T-cell populations. Depletion of endogenous myeloid DCs (myDCs) from the cultures decreased memory T-cell infection, and readdition of MDDCs restored infection to predepletion levels. Using an HIV-1 fusion assay, we found that MDDCs equally increased HIV delivery into naïve, central, and effector memory T cells in the cultures, whereas predepletion of myDCs reduced fusion into memory T cells. Together, these data suggest that resident myDCs facilitate memory T-cell infection in lymphoid tissues, implicating DC-mediated transinfection in driving HIV dissemination within these tissues in untreated HIV/AIDS.

  11. Particle size and surface charge affect particle uptake by human dendritic cells in an in vitro model

    DEFF Research Database (Denmark)

    Foged, Camilla; Brodin, Birger; Frøkjær, Sven;

    2005-01-01

    Current vaccine development includes optimization of antigen delivery to antigen presenting cells, such as dendritic cells (DC). Particulate systems have attracted increasing attention in the development of vaccine delivery systems. In the present study, we investigated DC uptake of model...

  12. Distinct molecular signature of human skin Langerhans cells denotes critical differences in cutaneous dendritic cell immune regulation.

    Science.gov (United States)

    Polak, Marta E; Thirdborough, Stephen M; Ung, Chuin Y; Elliott, Tim; Healy, Eugene; Freeman, Tom C; Ardern-Jones, Michael R

    2014-03-01

    Langerhans cells (LCs) are professional antigen-presenting cells (APCs) residing in the epidermis. Despite their high potential to activate T lymphocytes, current understanding of human LC biology is limited. Genome-wide comparison of the transcriptional profiles of human skin migratory CD1a+ LCs and CD11c+ dermal dendritic cells (DDCs) demonstrated significant differences between these "dendritic cell (DC)" types, including preferential expression of 625 genes (Pmolecular networks activated after stimulation with tumor necrosis factor-α (TNF-α) confirmed the unique molecular signature of LCs. Although LCs conformed to the phenotype of professional APC, inflammatory signaling activated primarily genes associated with cellular metabolism and mitochondrial activation (e.g., CYB561 and MRPS35), cell membrane re-organization, and antigen acquisition and degradation (CAV1 and PSMD14; P<0.05-P<0.0001). Conversely, TNF-α induced classical activation in DDCs with early downregulation of surface receptors (mannose receptor-1 (MRC1) and C-type lectins), and subsequent upregulation of cytokines, chemokines (IL1a, IL1b, and CCL18), and matrix metalloproteinases (MMP1, MMP3, and MMP9; P<0.05-P<0.0001). Functional interference of caveolin abrogated LCs superior ability to cross-present antigens to CD8+ T lymphocytes, highlighting the importance of these networks to biological function. Taken together, these observations support the idea of distinct biological roles of cutaneous DC types.

  13. NaDC3 Induces Premature Cellular Senescence by Promoting Transport of Krebs Cycle Intermediates, Increasing NADH, and Exacerbating Oxidative Damage.

    Science.gov (United States)

    Ma, Yuxiang; Bai, Xue-Yuan; Du, Xuan; Fu, Bo; Chen, Xiangmei

    2016-01-01

    High-affinity sodium-dependent dicarboxylate cotransporter 3 (NaDC3) is a key metabolism-regulating membrane protein responsible for transport of Krebs cycle intermediates. NaDC3 is upregulated as organs age, but knowledge regarding the underlying mechanisms by which NaDC3 modulates mammalian aging is limited. In this study, we showed that NaDC3 overexpression accelerated cellular senescence in young human diploid cells (MRC-5 and WI-38) and primary renal tubular cells, leading to cell cycle arrest in G1 phase and increased expression of senescent biomarkers, senescence-associated β-galactosidase and p16. Intracellular levels of reactive oxygen species, 8-hydroxy-2'-deoxyguanosine, malondialdehyde, and carbonyl were significantly enhanced, and activities of respiratory complexes I and III and ATP level were significantly decreased in NaDC3-infected cells. Stressful premature senescent phenotypes induced by NaDC3 were markedly ameliorated via treatment with the antioxidants Tiron and Tempol. High expression of NaDC3 caused a prominent increase in intracellular levels of Krebs cycle intermediates and NADH. Exogenous NADH and NAD(+) may aggravate and attenuate the aging phenotypes induced by NaDC3, respectively. These results suggest that NaDC3 can induce premature cellular senescence by promoting the transport of Krebs cycle intermediates, increasing generation of NADH and reactive oxygen species and leading to oxidative damage. Our results clarify the aging signaling pathway regulated by NaDC3.

  14. Human hematopoietic cell culture, transduction, and analyses

    DEFF Research Database (Denmark)

    Bonde, Jesper; Wirthlin, Louisa; Kohn, Donald B;

    2008-01-01

    This unit provides methods for introducing genes into human hematopoietic progenitor cells. The Basic Protocol describes isolation of CD34(+) cells, transduction of these cells with a retroviral vector on fibronectin-coated plates, assaying the efficiency of transduction, and establishing long...

  15. Human embryonic stem cells derived by somatic cell nuclear transfer.

    Science.gov (United States)

    Tachibana, Masahito; Amato, Paula; Sparman, Michelle; Gutierrez, Nuria Marti; Tippner-Hedges, Rebecca; Ma, Hong; Kang, Eunju; Fulati, Alimujiang; Lee, Hyo-Sang; Sritanaudomchai, Hathaitip; Masterson, Keith; Larson, Janine; Eaton, Deborah; Sadler-Fredd, Karen; Battaglia, David; Lee, David; Wu, Diana; Jensen, Jeffrey; Patton, Phillip; Gokhale, Sumita; Stouffer, Richard L; Wolf, Don; Mitalipov, Shoukhrat

    2013-06-06

    Reprogramming somatic cells into pluripotent embryonic stem cells (ESCs) by somatic cell nuclear transfer (SCNT) has been envisioned as an approach for generating patient-matched nuclear transfer (NT)-ESCs for studies of disease mechanisms and for developing specific therapies. Past attempts to produce human NT-ESCs have failed secondary to early embryonic arrest of SCNT embryos. Here, we identified premature exit from meiosis in human oocytes and suboptimal activation as key factors that are responsible for these outcomes. Optimized SCNT approaches designed to circumvent these limitations allowed derivation of human NT-ESCs. When applied to premium quality human oocytes, NT-ESC lines were derived from as few as two oocytes. NT-ESCs displayed normal diploid karyotypes and inherited their nuclear genome exclusively from parental somatic cells. Gene expression and differentiation profiles in human NT-ESCs were similar to embryo-derived ESCs, suggesting efficient reprogramming of somatic cells to a pluripotent state.

  16. Morusin Induces TRAIL Sensitization by Regulating EGFR and DR5 in Human Glioblastoma Cells.

    Science.gov (United States)

    Park, Dain; Ha, In Jin; Park, Sang-Yoon; Choi, Minji; Lim, Sung-Lyul; Kim, Sung-Hoon; Lee, Jun-Hee; Ahn, Kwang Seok; Yun, Miyong; Lee, Seok-Geun

    2016-02-26

    Glioblastoma is one of the most malignant primary tumors, and the prognosis for glioblastoma patients remains poor. Tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL) is considered a promising anticancer agent due to its remarkable ability to selectively kill tumor cells. However, since many cancers are resistant to TRAIL, strategies to overcome resistance are required for the successful use of TRAIL in the clinic. In the present study, the potential of morusin as a TRAIL sensitizer in human glioblastoma cells was evaluated. Treatment with TRAIL or morusin alone showed weak cytotoxicity in human glioblastoma cells. However, combination treatment of TRAIL with morusin synergistically decreased cell viability and increased apoptosis compared with single treatment. Morusin induced expression of death receptor 5 (DR5), but not DR4 or decoy receptors (DcR1 and DcR2). Furthermore, morusin significantly decreased anti-apoptotic molecules survivin and XIAP. In addition, morusin reduced expression of EGFR and PDFGR as well as phosphorylation of STAT3, possibly mediating down-regulation of survivin and XIAP. Together these results suggest that morusin enhances TRAIL sensitivity in human glioblastoma cells through regulating expression of DR5 and EGFR. Therefore, the combination treatment of TRAIL and morusin may be a new therapeutic strategy for malignant glioma patients.

  17. Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Jahns, Jutta [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Anderegg, Ulf; Saalbach, Anja [Department for Dermatology, Venerology and Allergology, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Rosin, Britt; Patties, Ina; Glasow, Annegret [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Kamprad, Manja [Institute for Clinical Immunology and Transfusion Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Scholz, Markus [Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Haertelstr. 16-18, 04103 Leipzig (Germany); Hildebrandt, Guido, E-mail: Guido.Hildebrandt@uni-rostock.de [Department of Radiotherapy and Radiation Oncology, University of Rostock, Suedring 75, 18059 Rostock (Germany); Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany)

    2011-05-10

    Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded.

  18. Human Neuroepithelial Cells Express NMDA Receptors

    Directory of Open Access Journals (Sweden)

    Cappell B

    2003-11-01

    Full Text Available Abstract L-glutamate, an excitatory neurotransmitter, binds to both ionotropic and metabotropic glutamate receptors. In certain parts of the brain the BBB contains two normally impermeable barriers: 1 cerebral endothelial barrier and 2 cerebral epithelial barrier. Human cerebral endothelial cells express NMDA receptors; however, to date, human cerebral epithelial cells (neuroepithelial cells have not been shown to express NMDA receptor message or protein. In this study, human hypothalamic sections were examined for NMDA receptors (NMDAR expression via immunohistochemistry and murine neuroepithelial cell line (V1 were examined for NMDAR via RT-PCR and Western analysis. We found that human cerebral epithelium express protein and cultured mouse neuroepithelial cells express both mRNA and protein for the NMDA receptor. These findings may have important consequences for neuroepithelial responses during excitotoxicity and in disease.

  19. Exogenous Thyropin from p41 Invariant Chain Diminishes Cysteine Protease Activity and Affects IL-12 Secretion during Maturation of Human Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Tina Zavašnik-Bergant

    Full Text Available Dendritic cells (DC play a pivotal role as antigen presenting cells (APC and their maturation is crucial for effectively eliciting an antigen-specific immune response. The p41 splice variant of MHC class II-associated chaperone, called invariant chain p41 Ii, contains an amino acid sequence, the p41 fragment, which is a thyropin-type inhibitor of proteolytic enzymes. The effects of exogenous p41 fragment and related thyropin inhibitors acting on human immune cells have not been reported yet. In this study we demonstrate that exogenous p41 fragment can enter the endocytic pathway of targeted human immature DC. Internalized p41 fragment has contributed to the total amount of the immunogold labelled p41 Ii-specific epitope, as quantified by transmission electron microscopy, in particular in late endocytic compartments with multivesicular morphology where antigen processing and binding to MHC II take place. In cell lysates of treated immature DC, diminished enzymatic activity of cysteine proteases has been confirmed. Internalized exogenous p41 fragment did not affect the perinuclear clustering of acidic cathepsin S-positive vesicles typical of mature DC. p41 fragment is shown to interfere with the nuclear translocation of NF-κB p65 subunit in LPS-stimulated DC. p41 fragment is also shown to reduce the secretion of interleukin-12 (IL-12/p70 during the subsequent maturation of treated DC. The inhibition of proteolytic activity of lysosomal cysteine proteases in immature DC and the diminished capability of DC to produce IL-12 upon their subsequent maturation support the immunomodulatory potential of the examined thyropin from p41 Ii.

  20. IRX-2, a novel immunotherapeutic, enhances functions of human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Bastian Schilling

    Full Text Available BACKGROUND: In a recent phase II clinical trial for HNSCC patients, IRX-2, a cell-derived biologic, promoted T-cell infiltration into the tumor and prolonged overall survival. Mechanisms responsible for these IRX-2-mediated effects are unknown. We hypothesized that IRX-2 enhanced tumor antigen-(TA-specific immunity by up-regulating functions of dendritic cells (DC. METHODOLOGY/PRINCIPAL FINDINGS: Monocyte-derived DC obtained from 18 HNSCC patients and 12 healthy donors were matured using IRX-2 or a mix of TNF-α, IL-1β and IL-6 ("conv. mix". Multicolor flow cytometry was used to study the DC phenotype and antigen processing machinery (APM component expression. ELISPOT and cytotoxicity assays were used to evaluate tumor-reactive cytotoxic T lymphocytes (CTL. IL-12p70 and IL-10 production by DC was measured by Luminex® and DC migration toward CCL21 was tested in transwell migration assays. IRX-2-matured DC functions were compared with those of conv. mix-matured DC. IRX-2-matured DC expressed higher levels (p<0.05 of CD11c, CD40, CCR7 as well as LMP2, TAP1, TAP2 and tapasin than conv. mix-matured DC. IRX-2-matured DC migrated significantly better towards CCL21, produced more IL-12p70 and had a higher IL12p70/IL-10 ratio than conv. mix-matured DC (p<0.05 for all. IRX-2-matured DC carried a higher density of tumor antigen-derived peptides, and CTL primed with these DC mediated higher cytotoxicity against tumor targets (p<0.05 compared to the conv. mix-matured DC. CONCLUSION: Excellent ability of IRX-2 to induce ex vivo DC maturation in HNSCC patients explains, in part, its clinical benefits and emphasizes its utility in ex vivo maturation of DC generated for therapy.

  1. Development of a new protocol for 2-day generation of mature dendritic cells from human monocytes

    OpenAIRE

    Obermaier Bianca; Dauer Marc; Herten Jan; Schad Katharina; Endres Stefan; Eigler Andreas

    2003-01-01

    We developed a new 2-day protocol for the generation of dendritic cells (DCs) from human monocytes in vitro. First, we demonstrated that 24 hours of culture with GM-CSF and IL-4 are sufficient to generate immature DCs capable of antigen uptake. We then compared two different strategies for DC maturation: proinflammatory mediators were either added together with GM-CSF and IL-4 from the beginning of cell culture or added after 24 hours of differentiation with GM-CSF and IL-4. After 48 hours of...

  2. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  3. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  4. CMOS Integrated Capacitive DC-DC Converters

    CERN Document Server

    Van Breussegem, Tom

    2013-01-01

    This book provides a detailed analysis of all aspects of capacitive DC-DC converter design: topology selection, control loop design and noise mitigation. Readers will benefit from the authors’ systematic overview that starts from the ground up, in-depth circuit analysis and a thorough review of recently proposed techniques and design methodologies.  Not only design techniques are discussed, but also implementation in CMOS is shown, by pinpointing the technological opportunities of CMOS and demonstrating the implementation based on four state-of-the-art prototypes.  Provides a detailed analysis of all aspects of capacitive DC-DC converter design;  Analyzes the potential of this type of DC-DC converter and introduces a number of techniques to unleash their full potential; Combines system theory with practical implementation techniques; Includes unique analysis of CMOS technology for this application; Provides in-depth analysis of four fabricated prototypes.

  5. Cytotoxicity effect of alkaloidal extract from Prosopis juliflora Sw. D.C. (Algaroba pods on glial cells

    Directory of Open Access Journals (Sweden)

    Juliana Bentes Hughes

    2006-12-01

    Full Text Available Prosopis juliflora is largely used for feeding cattle and humans. Neurological signals have been reported in cattle due to intoxication with this plant. In this study, an alkaloidal fraction (AF obtained from P. juliflora pods was tested on astrocyte primary cultures. Astrocytes display physiological functions essential to development, homeostasis and detoxification in the central nervous system (CNS. These cells are known for their role on energetic support and immune response in the CNS. Concentrations between 0.03 to 30 µg/ml AF were assayed for 24 - 72 h. The mitochondrial activity, assayed by MTT test, showed cytotoxicity at 30 µg/ml AF after 24 h. At concentrations ranging between 0.3 - 3 µg/ml, the AF induced an increase on mitochondrial activity, indicating cell reactivity. Immunocytochemistry assay for GFAP cytoskeletal protein, revealed alterations on cell morphology after treatment with 0.3 - 3 µg/ml AF for 72 h. This result corroborates with western blot analysis when cells treated with 0.3 - 3 µg/ml AF for 72 h showed GFAP upregulation. The vimentin expression was not significantly altered in all tested concentrations. These results suggest that alkaloids induce astrocyte reactivity and might be involved in the neurotoxic effects induced by P. juliflora consumption.

  6. Derivation of naive human embryonic stem cells.

    Science.gov (United States)

    Ware, Carol B; Nelson, Angelique M; Mecham, Brigham; Hesson, Jennifer; Zhou, Wenyu; Jonlin, Erica C; Jimenez-Caliani, Antonio J; Deng, Xinxian; Cavanaugh, Christopher; Cook, Savannah; Tesar, Paul J; Okada, Jeffrey; Margaretha, Lilyana; Sperber, Henrik; Choi, Michael; Blau, C Anthony; Treuting, Piper M; Hawkins, R David; Cirulli, Vincenzo; Ruohola-Baker, Hannele

    2014-03-25

    The naïve pluripotent state has been shown in mice to lead to broad and more robust developmental potential relative to primed mouse epiblast cells. The human naïve ES cell state has eluded derivation without the use of transgenes, and forced expression of OCT4, KLF4, and KLF2 allows maintenance of human cells in a naïve state [Hanna J, et al. (2010) Proc Natl Acad Sci USA 107(20):9222-9227]. We describe two routes to generate nontransgenic naïve human ES cells (hESCs). The first is by reverse toggling of preexisting primed hESC lines by preculture in the histone deacetylase inhibitors butyrate and suberoylanilide hydroxamic acid, followed by culture in MEK/ERK and GSK3 inhibitors (2i) with FGF2. The second route is by direct derivation from a human embryo in 2i with FGF2. We show that human naïve cells meet mouse criteria for the naïve state by growth characteristics, antibody labeling profile, gene expression, X-inactivation profile, mitochondrial morphology, microRNA profile and development in the context of teratomas. hESCs can exist in a naïve state without the need for transgenes. Direct derivation is an elusive, but attainable, process, leading to cells at the earliest stage of in vitro pluripotency described for humans. Reverse toggling of primed cells to naïve is efficient and reproducible.

  7. A human dendritic cell-based in vitro model to assess Mycobacterium tuberculosis SO2 vaccine immunogenicity.

    Science.gov (United States)

    Etna, Marilena P; Giacomini, Elena; Severa, Martina; Pardini, Manuela; Aguilo, Nacho; Martin, Carlos; Coccia, Eliana M

    2014-01-01

    Among the tuberculosis (TB) vaccine candidates, SO2 is the prototype of the first live-attenuated vaccine that recently entered into clinical trials. To investigate the capacity of SO2 to stimulate an appropriate immune response in vitro within a human immunological context, a comparative analysis of the effects promoted by SO2, the current Bacille Calmette-Guerin (BCG) vaccine and Mycobacterium tuberculosis (Mtb) was conducted in human primary dendritic cells (DC), which are critical modulators of vaccine-induced immunity. In particular, we found that SO2 promotes the expression of maturation markers similarly to BCG but at a lower extent than Mtb. Moreover, SO2-infected DC released higher levels of interleukin (IL)-23 than BCG-infected cells, which account for the expansion of interferon (IFN)-γ-producing T cells in an IL-12-independent manner. In the autologous mixed leukocyte reaction setting, the expansion of IL-17-producing T cells was also observed in response to SO2 infection. Interestingly, apoptosis and autophagic flux, events required for the antigen presentation within MHC class II complex, were not affected in DC infected with SO2, conversely to what observed upon Mtb stimulation. Collectively, our results indicate that SO2 represents a promising TB vaccine candidate, which displays an attenuated phenotype and promotes in DC a stronger capacity to stimulate the Th response than BCG vaccine. Interestingly, the data obtained by using the human DC-based experimental setting mirrored the results derived from studies in animal models, suggesting that this system could be used for an efficient and rapid down-selection of new TB vaccine candidates, contributing to achieve the "3Rs" objective.

  8. Differential interleukin-10 (IL-10) and IL-23 production by human blood monocytes and dendritic cells in response to commensal enteric bacteria.

    Science.gov (United States)

    Manuzak, Jennifer; Dillon, Stephanie; Wilson, Cara

    2012-08-01

    Human peripheral blood contains antigen-presenting cells (APC), including dendritic cells (DC) and monocytes, that may encounter microbes that have translocated from the intestine to the periphery in disease states like HIV-1 infection and inflammatory bowel disease. We investigated the response of DC and monocytes in peripheral blood mononuclear cells (PBMC) to a panel of representative commensal enteric bacteria, including Escherichia coli, Enterococcus sp., and Bacteroides fragilis. All three bacteria induced significant upregulation of the maturation and activation markers CD40 and CD83 on myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC). However, only mDC produced cytokines, including interleukin-10 (IL-10), IL-12p40/70, and tumor necrosis factor alpha (TNF-α), in response to bacterial stimulation. Cytokine profiles in whole PBMC differed depending on the stimulating bacterial species: B. fragilis induced production of IL-23, IL-12p70, and IL-10, whereas E. coli and Enterococcus induced an IL-10-predominant response. mDC and monocyte depletion experiments indicated that these cell types differentially produced IL-10 and IL-23 in response to E. coli and B. fragilis. Bacteroides thetaiotaomicron did not induce levels of IL-23 similar to those of B. fragilis, suggesting that B. fragilis may have unique proinflammatory properties among Bacteroides species. The addition of recombinant human IL-10 to PBMC cultures stimulated with commensal bacteria abrogated the IL-23 response, whereas blocking IL-10 significantly enhanced IL-23 production, suggesting that IL-10 controls the levels of IL-23 produced. These results indicate that blood mDC and monocytes respond differentially to innate stimulation with whole commensal bacteria and that IL-10 may play a role in controlling the proinflammatory response to translocated microbes.

  9. Regulatory T Cells in Human Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Dong-Jun Peng

    2012-01-01

    Full Text Available Multiple layers of suppressive components including regulatory T (TReg cells, suppressive antigen-presenting cells, and inhibitory cytokines form suppressive networks in the ovarian cancer microenvironment. It has been demonstrated that as a major suppressive element, TReg cells infiltrate tumor, interact with several types of immune cells, and mediate immune suppression through different molecular and cellular mechanisms. In this paper, we focus on human ovarian cancer and will discuss the nature of TReg cells including their subsets, trafficking, expansion, and function. We will briefly review the development of manipulation of TReg cells in preclinical and clinical settings.

  10. Monocyte derived dendritic cells generated by IFN-α acquire mature dendritic and natural killer cell properties as shown by gene expression analysis

    OpenAIRE

    Czibere Akos; Winter Meike; Diaz Blanco Elena; Papewalis Claudia; Schott Matthias; Maihöfer Dagmar; Kronenwett Ralf; Safaian Nancy; Korthals Mark; Haas Rainer; Kobbe Guido; Fenk Roland

    2007-01-01

    Abstract Background Dendritic cell (DC) vaccines can induce antitumor immune responses in patients with malignant diseases, while the most suitable DC culture conditions have not been established yet. In this study we compared monocyte derived human DC from conventional cultures containing GM-CSF and IL-4/TNF-α (IL-4/TNF-DC) with DC generated by the novel protocol using GM-CSF and IFN-α (IFN-DC). Methods To characterise the molecular differences of both DC preparations, gene expression profil...

  11. Generation of pancreatic islet cells from human embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG DongHui; JIANG Wei; SHI Yan; DENG HongKui

    2009-01-01

    Efficiently obtaining functional pancreaUc islet cells derived from human embryonic stem (hES) cells not only provides great potential to solve the shortage of islets sources for type I diabetes cell therapy,but also benefits the study of the development of the human pancreas and diabetes pathology. In 2001,hES cells were reported to have the capacity to generate insulin-producing cells by spontaneous differentiation in vitro. Since then, many strategies (such as overexpression of key transcription factors,delivery of key proteins for pancreatic development, co-transplantation of differentiated hES cells along with fetal pancreas, stepwise differentiation by mimicking in vivo pancreatic development) have been employed in order to induce the differentiation of pancreatic islet cells from hES cells. Moreover, patient-specific induced pluripotent stem (iPS) cells can be generated by reprogramming somatic cells.iPS cells have characteristics similar to those of ES cells and offer a new cell source for type I diabetes cell therapy that reduces the risk of immunologic rejection. In this review, we summarize the recent progress made in the differentiation of hES and iPS cells into functional pancreatic islet cells and discuss the challenges for their future study.

  12. Generation of pancreatic islet cells from human embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Efficiently obtaining functional pancreatic islet cells derived from human embryonic stem(hES) cells not only provides great potential to solve the shortage of islets sources for type I diabetes cell therapy,but also benefits the study of the development of the human pancreas and diabetes pathology.In 2001,hES cells were reported to have the capacity to generate insulin-producing cells by spontaneous differentiation in vitro.Since then,many strategies(such as overexpression of key transcription factors,delivery of key proteins for pancreatic development,co-transplantation of differentiated hES cells along with fetal pancreas,stepwise differentiation by mimicking in vivo pancreatic development) have been employed in order to induce the differentiation of pancreatic islet cells from hES cells.Moreover,patient-specific induced pluripotent stem(iPS) cells can be generated by reprogramming somatic cells.iPS cells have characteristics similar to those of ES cells and offer a new cell source for type I diabetes cell therapy that reduces the risk of immunologic rejection.In this review,we summarize the recent progress made in the differentiation of hES and iPS cells into functional pancreatic islet cells and discuss the challenges for their future study.

  13. DC/DC Converter Stability Testing Study

    Science.gov (United States)

    Wang, Bright L.

    2008-01-01

    This report presents study results on hybrid DC/DC converter stability testing methods. An input impedance measurement method and a gain/phase margin measurement method were evaluated to be effective to determine front-end oscillation and feedback loop oscillation. In particular, certain channel power levels of converter input noises have been found to have high degree correlation with the gain/phase margins. It becomes a potential new method to evaluate stability levels of all type of DC/DC converters by utilizing the spectral analysis on converter input noises.

  14. Plasma membrane proteomics of human embryonic stem cells and human embryonal carcinoma cells.

    NARCIS (Netherlands)

    Dormeyer, W.; van Hoof, D.; Braam, S.R.; Heck, A.J.R.; Mummery, C.L.; Krijgsveld, J.

    2008-01-01

    Human embryonic stem cells (hESCs) are of immense interest in regenerative medicine as they can self-renew indefinitely and can give rise to any adult cell type. Human embryonal carcinoma cells (hECCs) are the malignant counterparts of hESCs found in testis tumors. hESCs that have acquired chromosom

  15. Effects of dendritic cells from cord blood CD34+ cells on human hepatocarcinoma cell line BEL-7402 in vitro and in SCID mice

    Institute of Scientific and Technical Information of China (English)

    Zhong-Jing Su; Hai-Bin Chen; Jin-Kun Zhang; Lan Xu

    2005-01-01

    AIM: To develop a cancer vaccine of dendritic cells derived from human cord blood CD34+ cells and to investigate its cytotoxicity on human hepatocarcinoma cells in vitro and in sever combined immunodeficiency (SCTD) mice.METHODS: Lymphocytes from cord blood or peripheral blood were primed by DCs, which were derived from cord blood and pulsed with whole tumor cell lysates. Nonradiative neutral red uptake assay was adopted to detect the cytotoxicity of primed lymphocytes on human hepatocarcinoma cell line BEL-7402 in vitro. The anti-tumor effect of primed lymphocytes in vivo was detected in SCID mice, including therapeutic effect and vaccination effect.RESULTS: The cytotoxicity of DC vaccine primed lymphocytes from cord blood or peripheral blood on human hepatocarcinoma cell line BEL-7402 was significantly higher than that of unprimed lymphocytes in vitro (44.09% vs 14.69%,47.92% vs 19.44%, P<0.01). There was no significant difference between the cytotoxicity of primed lymphocytes from cord blood and peripheral blood (P>0.05). The tumor growth rate and tumor size were smaller in SCID mice treated or vaccinated with primed lymphocytes than those with unprimed lymphocytes. SCID mice vaccinated with primed lymphocytes had a lower tumor incidence (80%vs 100%, P<0.05) and delayed tumor latent period compared with mice vaccinated with unprimed lymphocytes (11 d vs 7 d, P<0.01).CONCLUSION: Vaccine of cord blood derived-DCs has an inhibitory activity on growth of human hepatocarcinoma cells in vitro and in SCID mice. The results also implicate the potential role of cord blood derived-DC vaccine in clinical tumor immunotherapy.

  16. Human dendritic cells mediate cellular apoptosis via tumor necrosis factor-related apoptosis-inducing ligand (TRAIL).

    Science.gov (United States)

    Fanger, N A; Maliszewski, C R; Schooley, K; Griffith, T S

    1999-10-18

    TRAIL (TNF-related apoptosis-inducing ligand) is a member of the TNF family that induces apoptosis in a variety of cancer cells. In this study, we demonstrate that human CD11c(+) blood dendritic cells (DCs) express TRAIL after stimulation with either interferon (IFN)-gamma or -alpha and acquire the ability to kill TRAIL-sensitive tumor cell targets but not TRAIL-resistant tumor cells or normal cell types. The DC-mediated apoptosis was TRAIL specific, as soluble TRAIL receptor blocked target cell death. Moreover, IFN-stimulated interleukin (IL)-3 receptor (R)alpha(+) blood precursor (pre-)DCs displayed minimal cytotoxicity toward the same target cells, demonstrating a clear functional difference between the CD11c(+) DC and IL-3Ralpha(+) pre-DC subsets. These results indicate that TRAIL may serve as an innate effector molecule on CD11c(+) DCs for the elimination of spontaneously arising tumor cells and suggest a means by which TRAIL-expressing DCs may regulate or eliminate T cells responding to antigen presented by the DCs.

  17. Derivation of Human Skin Fibroblast Lines for Feeder Cells of Human Embryonic Stem Cells.

    Science.gov (United States)

    Unger, Christian; Felldin, Ulrika; Rodin, Sergey; Nordenskjöld, Agneta; Dilber, Sirac; Hovatta, Outi

    2016-02-03

    After the first derivations of human embryonic stem cell (hESC) lines on fetal mouse feeder cell layers, the idea of using human cells instead of mouse cells as feeder cells soon arose. Mouse cells bear a risk of microbial contamination, and nonhuman immunogenic proteins are absorbed from the feeders to hESCs. Human skin fibroblasts can be effectively used as feeder cells for hESCs. The same primary cell line, which can be safely used for up to 15 passages after stock preparations, can be expanded and used for large numbers of hESC derivations and cultures. These cells are relatively easy to handle and maintain. No animal facilities or animal work is needed. Here, we describe the derivation, culture, and cryopreservation procedures for research-grade human skin fibroblast lines. We also describe how to make feeder layers for hESCs using these fibroblasts.

  18. Phenotype comparison between bone marrow derived dendritic cell and DC2.4 cell stimulated with antigen from Schistosoma japonicum%血吸虫抗原刺激小鼠骨髓来源的树突状细胞与DC2.4细胞的表型比较

    Institute of Scientific and Technical Information of China (English)

    李小红; 曹建平; 汤林华; 王胜军; 成静

    2011-01-01

    目的 研究比较小鼠树突状细胞DC2.4和骨髓来源树突状细胞(bone marrow derived dendritic cell,BMDC)经血吸虫抗原谷胱甘肽转移酶(GST)刺激后表面分子的表达异同.方法 骨髓来源的细胞经白介素4(interleukin 4,IL-4)、粒细胞-巨噬细胞集落刺激因子(granulocyte-macrophage colonystimulating factor,GM-CSF)诱导培养,获得树突状细胞.常规方法培养DC2.4.体外用日本血吸虫抗原GST刺激前述两种细胞,以PBS和脂多糖(lipopolysaccharide,LPS)作对照,流式细胞仪检测细胞表面分子CD40、CDSO、CD86的平均荧光强度,并进行统计学分析.结果 日本血吸虫抗原GST刺激BMDC后,表面分子CD40、CD80、CD86的平均荧光强度依次为100.39、42.38、170.83,与PBS对照组比较,CD40无明显变化,而CD80、CD86表达上调(P<0.01);GST刺激DC2.4后,细胞表面分子CD40、CD80、CD86的平均荧光强度依次为23.73、72.13、59.58,与PBS对照组比较,CD40和CD86表达上调(P<0.01),而CD80变化不明显.结论 DC2.4与BMDC经日本血吸虫抗原刺激后表面分子的表达变化不同.%Objective To compare the phenotypes of bone marrow derived dendritic cell(BMDC)and DC2.4 cell stimulated with GST from Schistosoma japonicum.Methods Bone marrow cells were cultured in the presence of IL-4 and GM-CSF to induce dendritic cells.DC2.4 cells were cultured as routine.Both cells were stimulated with GST and the expressions of CD40,CD80 and CD86 on the cells'surface were analyzed by FACS,using PBS and lipopolysaccharide as controls. Results After stimulating with GST,the means of fluorescence intensity(MFI)for CD40,CD80 and CD86 on BMDC surface were 100.39,42.38 and 170.83,respectively.Compared with PBS control,the MFI of CD80 and CD86 on BMDC,but not CD40,enhanced significantly.The MFIs of CD40.CD80 and CD86 on DC2.4 loaded by GST were 23.73,72.13 and 59.58 respectively.Compared with PBS control,the expressions of CD40 and CD86 enhanced significantly after schistosome

  19. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Nora [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Vereb, Zoltan; Rajnavoelgyi, Eva [Department of Immunology, Medical and Health Science Centre, University of Debrecen, Debrecen (Hungary); Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Apati, Agota, E-mail: apati@kkk.org.hu [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  20. Therapeutic outcomes of combining cryotherapy, chemotherapy and DC-CIK immunotherapy in the treatment of metastatic non-small cell lung cancer.

    Science.gov (United States)

    Yuanying, Yuan; Lizhi, Niu; Feng, Mu; Xiaohua, Wang; Jianying, Zeng; Fei, Yao; Feng, Jiang; Lihua, He; Jibing, Chen; Jialiang, Li; Kecheng, Xu

    2013-10-01

    Currently there are no effective therapies for the treatment of metastatic non-small cell lung cancer (NSCLC). Here, we conducted a retrospective study of 161 patients to evaluate the therapeutic effects of combining cryosurgery, chemotherapy and dendritic cell-activated cytokine-induced killer cells (DC-CIK) immunotherapy. The overall survival (OS) after diagnosis of metastatic NSCLC to patient death was assessed during a 5-years follow-up period. OS of patients who received comprehensive cryotherapy was (median OS, 20 months; n = 86) significantly longer than that of patients who did not received cryotherapy (median OS, 10 months; n = 75; P < 0.0001). Five treatment combinations were selected: chemotherapy (n = 44); chemo-immunotherapy (n = 31); cryo-chemotherapy (n = 32); cryo-immunotherapy (n = 21); and cryo-chemo-immunotherapy (n = 33). A combination of cryotherapy with either chemotherapy or immunotherapy lead to significantly longer OS (18 months and 17 months, respectively) compared to chemotherapy and chemo-immunotherapy (8.5 months and 12 months, respectively; P < 0.001); however, the median OS of patients who underwent cryo-chemo-immunotherapy was significantly longer (27 months) compared to the other treatment programs (P < 0.001). In conclusion, a combination of cryotherapy, chemotherapy and DC-CIK immunotherapy proved the best treatment option for metastatic NSCLC in this group of patients. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. 76 FR 31462 - Airworthiness Directives; The Boeing Company Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10...

    Science.gov (United States)

    2011-06-01

    ... Model DC-10-10, DC- 10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F... Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.... Applicability (c) This AD applies to all The Boeing Company Model DC-10-10, DC-10-10F, DC-10-15,......

  2. Stem cells in the human breast

    DEFF Research Database (Denmark)

    Petersen, Ole William; Polyak, Kornelia

    2010-01-01

    The origins of the epithelial cells participating in the development, tissue homeostasis, and cancer of the human breast are poorly understood. However, emerging evidence suggests a role for adult tissue-specific stem cells in these processes. In a hierarchical manner, these generate the two main...

  3. Human hair genealogies and stem cell latency

    Directory of Open Access Journals (Sweden)

    Tavaré Simon

    2006-02-01

    Full Text Available Abstract Background Stem cells divide to reproduce themselves and produce differentiated progeny. A fundamental problem in human biology has been the inability to measure how often stem cells divide. Although it is impossible to observe every division directly, one method for counting divisions is to count replication errors; the greater the number of divisions, the greater the numbers of errors. Stem cells with more divisions should produce progeny with more replication errors. Methods To test this approach, epigenetic errors (methylation in CpG-rich molecular clocks were measured from human hairs. Hairs exhibit growth and replacement cycles and "new" hairs physically reappear even on "old" heads. Errors may accumulate in long-lived stem cells, or in their differentiated progeny that are eventually shed. Results Average hair errors increased until two years of age, and then were constant despite decades of replacement, consistent with new hairs arising from infrequently dividing bulge stem cells. Errors were significantly more frequent in longer hairs, consistent with long-lived but eventually shed mitotic follicle cells. Conclusion Constant average hair methylation regardless of age contrasts with the age-related methylation observed in human intestine, suggesting that error accumulation and therefore stem cell latency differs among tissues. Epigenetic molecular clocks imply similar mitotic ages for hairs on young and old human heads, consistent with a restart with each new hair, and with genealogies surreptitiously written within somatic cell genomes.

  4. Dual Input High Step-up DC-DC Converters With Voltage Multiplier Cells%一种基于倍压单元的双输入高增益直流变换器

    Institute of Scientific and Technical Information of China (English)

    孙鹏菊; 李正宇; 张冀; 周雒维

    2016-01-01

    According to the problems that more than one energy source, low output voltage of the battery module and unstable output power in the distributed photovoltaic power generation system, a dual input high step-up DC-DC converter with capacitor-diode multiplier cells was proposed in this paper. The proposed topology has the following advantages: the voltage gain is high, the voltage stress of the switches is low, there are more control freedoms and the sources can deliver power to the load with flexible power management methods. Firstly, the operation mode and the performance characteristics of the converter were presented in detail. Secondly, the steady state analysis, the voltage and current stresses of the switches and the relationship between the input currents were also introduced. Finally, the correctness and feasibility of the proposed circuit topology and the theoretical analysis were fully verified by a 1000W prototype.%针对分布式光伏发电系统电池模块多、输出电压低、功率不稳定等问题,提出了一种基于电容-二极管倍压单元的双输入高增益Boost型直流变换器。该变换器具有电压调节增益高、开关器件电压应力小、控制自由度多、各输入源功率可灵活分配等优点。首先分析了双输入高增益 Boost变换器的工作原理及性能特点,给出了变换器的稳态关系式及开关管电压电流应力计算结果,最后通过一台1000W的实验样机,验证了电路拓扑和理论分析的可行性和正确性。

  5. Human neutrophils facilitate tumor cell transendothelial migration.

    LENUS (Irish Health Repository)

    Wu, Q D

    2012-02-03

    Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

  6. DC to DC converters: operation; Hacheurs: fonctionnement

    Energy Technology Data Exchange (ETDEWEB)

    Bernot, F. [Ecole d' Ingenieurs de Tours, 37 (France)

    2002-05-01

    This article deals with pulse width modulation (PWM) and pulse position modulation (PPM) DC to DC converters. A tri-phase PWM converter is made of 6 simple DC/DC converters grouped together into 3 reversible converters of the same type: 1 - single-quadrant voltage lowering converters (hydraulic analogy, study with ideal elements, full scheme with input and output filters); 2 - single-quadrant voltage raising converters (hydraulic analogy, operation); 3 - two quadrants reversible converters (structure construction, quadrants of operation, reversible converter connected to a DC motor); 4 - four-quadrants reversible converters; 5 - other converters structure (current converters and converters with intermediate storage, asymmetrical converters, converters with capacitive storage, insulated converters, resonating converters, status); 6 - conclusion. (J.S.)

  7. Antitumor activities of human dendritic cells derived from peripheral and cord blood

    Institute of Scientific and Technical Information of China (English)

    Jin-Kun Zhang; Jun Li; Hai-Bin Chen; Jin-Lun Sun; Yao-Juan Qu; Juan-Juan Lu

    2002-01-01

    AIM: To observe the biological specialization of humanperipheral blood dendritic cells (DC) and cord blood derivedDC and its effects on effector cells killing humanhepatocarcinoma cell line BEL-7402 in vitro.METHODS: The DC biological characteristics were detectedwith immunohistochemical and MTT assay. Two antitumorexperimental groups are: peripheral blood DC and cordblood DC groups. Peripheral blood DC groups used LAKcells as the effector cells and BEL-7402 as target cells, whilecord blood DC groups used CTL induced by tumor antigentwice pulsed DC as effector cells and BEL-7402 as targetcells, additional peripheral blood DC and cord blood DC areadded to observe its stimulating activities to effector cells.The effector's cytotoxicity to tumor cells were detected withneutral red colorimetric assay at two effector/target ratios of5:1 and 10: 1.RESULTS: Peripheral blood DC and cord blood DC highlyexpressed HLA-ABC, HLA-DR, HLA-DQ, CD54 and S-100protein. The stimulating activities to lymphocyteproliferation were compared between experimental groups(DC added) and control group (no DC added). In sixexperiment subgroups, the DC/lymphocyte ratio wassequentially 0.25: 100, 0.5: 100, 1: 100, 2: 100, 4: 100 and 8:100, A values(x± s) were 0.75396± 0.009, 0.84916± 0.010,0.90894± 0.012, 0.98371 ± 0.007, 1.01299 ± 0.006 and 1.20384± 0.006 in peripheral blood DC groups and 0.77650 ± 0.005,0.83008± 0.007, 0.92725 ± 0.007, 1.05990 ± 0.010, 1.15583 ±0.011, 1.22983 ± 0.011 in cord blood DC groups. A value was0.59517 ± 0.005 in control group. The stimulating activitieswere higher in experimental groups than in control group ( P< 0.01 ), which were increased when the DC concentrationwas enlarged ( P < 0.01 ). Two differently derived DCs hadthe same phenotypes and similar stimulating activities ( P >0.05). In peripheral blood DC groups, the cytotoxicity (x ±s) of the LD groups (experimental groups) and L groups(control group) was 58.16% ± 2.03% (5: 1), 46.18% ±2

  8. Macrophage galactose-type C-type lectin receptor for DC targeting of antitumor glycopeptide vaccines

    DEFF Research Database (Denmark)

    Nuti, M; Zizzari, I; Napoletano, C;

    2011-01-01

    e13528 Background: Dendritic cells (DCs) are the most potent antigen presenting cells and are employed in cancer vaccination. Several receptors are being studied in order to identif strategies to increase DCs activating capacity. The C-type lectin macrophage galactose type C-type lectin (MGL...... of IFNg and IL-2 secretion by both CD8 and CD4 T cells. CONCLUSIONS: These results demonstrate that MGL engagement profoundly affects DC plasticity inducing and directing a Th1 immune response. Moreover, MGL receptor expressed on human DC can be targeted by glycopeptide based vaccines with adjuvant...

  9. IL-10 promotes homeostatic proliferation of human CD8(+) memory T cells and, when produced by CD1c(+) DCs, shapes naive CD8(+) T-cell priming.

    Science.gov (United States)

    Nizzoli, Giulia; Larghi, Paola; Paroni, Moira; Crosti, Maria Cristina; Moro, Monica; Neddermann, Petra; Caprioli, Flavio; Pagani, Massimiliano; De Francesco, Raffaele; Abrignani, Sergio; Geginat, Jens

    2016-07-01

    IL-10 is an anti-inflammatory cytokine that inhibits maturation and cytokine production of dendritic cells (DCs). Although mature DCs have the unique capacity to prime CD8(+) CTL, IL-10 can promote CTL responses. To understand these paradoxic findings, we analyzed the role of IL-10 produced by human APC subsets in T-cell responses. IL-10 production was restricted to CD1c(+) DCs and CD14(+) monocytes. Interestingly, it was differentially regulated, since R848 induced IL-10 in DCs, but inhibited IL-10 in monocytes. Autocrine IL-10 had only a weak inhibitory effect on DC maturation, cytokine production, and CTL priming with high-affinity peptides. Nevertheless, it completely blocked cross-priming and priming with low-affinity peptides of a self/tumor-antigen. IL-10 also inhibited CD1c(+) DC-induced CD4(+) T-cell priming and enhanced Foxp3 induction, but was insufficient to induce T-cell IL-10 production. CD1c(+) DC-derived IL-10 had also no effect on DC-induced secondary expansions of memory CTL. However, IL-15-driven, TCR-independent proliferation of memory CTL was enhanced by IL-10. We conclude that DC-derived IL-10 selects high-affinity CTL upon priming. Moreover, IL-10 preserves established CTL memory by enhancing IL-15-dependent homeostatic proliferation. These combined effects on CTL priming and memory maintenance provide a plausible mechanism how IL-10 promotes CTL responses in humans.

  10. Transcriptional profiling of human dendritic cell populations and models--unique profiles of in vitro dendritic cells and implications on functionality and applicability.

    Directory of Open Access Journals (Sweden)

    Kristina Lundberg

    Full Text Available BACKGROUND: Dendritic cells (DCs comprise heterogeneous populations of cells, which act as central orchestrators of the immune response. Applicability of primary DCs is restricted due to their scarcity and therefore DC models are commonly employed in DC-based immunotherapy strategies and in vitro tests assessing DC function. However, the interrelationship between the individual in vitro DC models and their relative resemblance to specific primary DC populations remain elusive. OBJECTIVE: To describe and assess functionality and applicability of the available in vitro DC models by using a genome-wide transcriptional approach. METHODS: Transcriptional profiling was performed with four commonly used in vitro DC models (MUTZ-3-DCs, monocyte-derived DCs, CD34-derived DCs and Langerhans cells (LCs and nine primary DC populations (dermal DCs, LCs, blood and tonsillar CD123(+, CD1c(+ and CD141(+ DCs, and blood CD16(+ DCs. RESULTS: Principal Component Analysis showed that transcriptional profiles of each in vitro DC model most closely resembled CD1c(+ and CD141(+ tonsillar myeloid DCs (mDCs among primary DC populations. Thus, additional differentiation factors may be required to generate model DCs that more closely resemble other primary DC populations. Also, no model DC stood out in terms of primary DC resemblance. Nevertheless, hierarchical clustering showed clusters of differentially expressed genes among individual DC models as well as primary DC populations. Furthermore, model DCs were shown to differentially express immunologically relevant transcripts and transcriptional signatures identified for each model DC included several immune-associated transcripts. CONCLUSION: The unique transcriptional profiles of in vitro DC models suggest distinct functionality in immune applications. The presented results will aid in the selection of an appropriate DC model for in vitro assays and assist development of DC-based immunotherapy.

  11. Effects of human respiratory syncytial virus, metapneumovirus, parainfluenza virus 3 and influenza virus on CD4+ T cell activation by dendritic cells.

    Directory of Open Access Journals (Sweden)

    Cyril Le Nouën

    Full Text Available BACKGROUND: Human respiratory syncytial virus (HRSV, and to a lesser extent human metapneumovirus (HMPV and human parainfluenza virus type 3 (HPIV3, re-infect symptomatically throughout life without antigenic change, suggestive of incomplete immunity. One causative factor is thought to be viral interference with dendritic cell (DC-mediated stimulation of CD4+ T cells. METHODOLOGY, PRINCIPAL FINDINGS: We infected human monocyte-derived DC with purified HRSV, HMPV, HPIV3, or influenza A virus (IAV and compared their ability to induce activation and proliferation of autologous CD4+ T cells in vitro. IAV was included because symptomatic re-infection without antigenic change is less frequent, suggesting that immune protection is more complete and durable. We examined virus-specific memory responses and superantigen-induced responses by multiparameter flow cytometry. Live virus was more stimulatory than inactivated virus in inducing DC-mediated proliferation of virus-specific memory CD4+ T cells, suggesting a lack of strong suppression by live virus. There were trends of increasing proliferation in the order: HMPVcells in response to IAV, but differences were not significant. Exposure of DC to HRSV, HPIV3, or IAV reduced CD4+ T cell proliferation in response to secondary stimulus with superantigen, but the effect was transitory and greatest for IAV. T cell cytokine production was similar, with no evidence of Th2 or Th17 skewing. CONCLUSIONS, SIGNIFICANCE: Understanding the basis for the ability of HRSV in particular to symptomatically re-infect without significant antigenic change is of considerable interest. The present results show that these common respiratory viruses are similar in their ability to induce DC to activate CD4+ T cells. Thus, the results do not support the common model in which viral suppression of CD4+ T cell activation and

  12. INTERACTIONS BETWEEN THE HUMAN GASTRIC CARCINOMA CELL AND THE HUMAN VASCULAR ENDOTHELIAL CELL

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To definite the interactions between the human gastric carcinoma cell and the human vascular endothelial cell during the establishment and maintenance of the tumor vascular system and the tumor hematogenous metastasis.Methods We prepared the conditioned mediums of each cell so as to study the effect of the conditioned medium on itself or others by MTT colorimetry. The comprehensive effect of interactions between two cells was determined by stratified transfilter co-culture or direct contact co-culture.Results The conditioned medium of human gastric carcinoma cell can stimulate the proliferation of the human vascular endothelial cell, but the CM of HVEC can inhibit the growth of HGCC. Both kinds of cells can inhibit the growth of itself. The ultimate comprehensive effect of the interactions between two kinds of cells was increase of total cell numbers.Conclusion There exist the complicated interactions between the human gastric carcinoma cell and the human vascular endothelial cell during the tumor angiogenesis and the tumor hematogenous metastasis. The ultimate comprehensive effect of the interactions is increase of total cells numbers and tumor volume.

  13. DC-CIK细胞用于治疗急性髓系白血病MRD的研究%Clinical study of DC-CIK cells for the treatment of acute myeloid leukemia MRD

    Institute of Scientific and Technical Information of China (English)

    王漪; 张曦; 李罡灿; 宋艳萍; 郭亮

    2013-01-01

    Objective:to evaluate the efficacy of DC-CIK immunotherapy on the minimal residual disease (MRD)of acute myeloid leukemia.Methods:11 acute myeloid leukemia patients of MRD positive were treated with DC-CIK adoptive immunotherapy,and monitored change of MRD by flow cytometry(FCM).Results:MRD in the 7 cases became negative,and in continuous complete remission; The other 4 cases were relapsed.Conclusion:DC-CIK adoptive immunotherapy can be used to eradicate MRD in AML.%目的:探讨DC-CIK细胞治疗急性髓系白血病微小残留病灶的疗效.方法:对11例经化疗后MRD阳性的急性髓系白血病患者进行DC-CIK过继免疫治疗,并用FCM监测MRD变化.结果:经FCM检测,11例患者中7例MRD转阴,并处于持续完全缓解状态,其余4例(M21例,M4 2例,M5 1例)均复发.结论:DC-CIK过继免疫治疗具有清除急性髓系白血病MRD的作用.

  14. ANALYSIS OF THE EXPRESSION OF MRP, THE GENE FOR A NEW PUTATIVE TRANSMEMBRANE DRUG TRANSPORTER, IN HUMAN MULTIDRUG RESISTANT LUNG-CANCER CELL-LINES

    NARCIS (Netherlands)

    ZAMAN, GJR; VERSANTVOORT, CHM; SMIT, JJM; EIJDEMS, EWHM; DEHAAS, M; SMITH, AJ; BROXTERMAN, HJ; MULDER, NH; DEVRIES, EGE; BAAS, F; BORST, P

    1993-01-01

    Human cells can become multidrug resistant (MDR) by an increase in the activity of the MDR1 P-glycoprotein or by other, as vet unknown mechanisms, referred to as non-P-glycoprotein mediated MDR (non-Pgp MDR). S. P. C. Cole et al. [Science (Washington DC), 258: 1650-1654, 1992] recently reported that

  15. Fibronectin production by human mammary cells

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, M.R. (Univ. of California, Berkeley); Vlodavsky, I.; Smith, H.S.; Ford, R.; Becker, F.F.; Riggs, J.

    1981-01-01

    Human mammary cells were examined for the presence of the high-molecular-weight surface glycoprotein fibronectin. Early passage mammary epithelial cell and fibroblast cultures from both carcinomas and normal tissues were tested for the presence of cell-associated fibronectin by immunofluorescence microscopy and for the synthesis and secretion of fibronectin by specific immunoprecipitation of metabolically labeled protein. In vivo frozen sections of primary carcinomas and normal tissues were tested for the localization of fibronectin by immunofluorescence microscopy. In contrast to the extensive fibrillar networks of fibronectin found in the fibroblast cultures, the epithelial cell cultures from both tissue sources displayed a pattern of cell-associated fibronectin characterizd by powdery, punctate staining. However, the cultured epithelial cells, as well as the fibroblasts, secreted large quantities of fibronectin into the medium. Putative myoepithelial cells also displayed extensive fibrillar networks of fibronectin. The difference in cell-associated fibronectin distribution between the epithelial cells and the fibroblasts and putative myoepithelial cells provided a simple means of quantitating stromal and myoepithelial cell contamination of the mammary epithelial cells in culture. In vivo, normal tissues showed fibronectin primarily localized in the basement membrane surrounding the epithelial cells and in the stroma. Most primary carcinomas displayed powdery, punctate staining on the epithelial cells in addition to the fibronectin present in the surrounding stroma.

  16. Deciphering the role of DC subsets in MCMV infection to better understand immune protection against viral infections

    Directory of Open Access Journals (Sweden)

    Marc eDALOD

    2014-07-01

    Full Text Available Infection of mice with murine cytomegalovirus (MCMV recapitulates many physiopathological characteristics of human CMV infection and enables studying the interactions between a virus and its natural host. Dendritic cells (DC are mononuclear phagocytes linking innate and adaptive immunity which are both necessary for MCMV control. DC are critical for the induction of cellular immunity because they are uniquely efficient for the activation of naïve T cells during their first encounter with a pathogen. DC are equipped with a variety of innate immune recognition receptors (I2R2 allowing them to detect pathogens or infections and to engulf molecules, microorganisms or cellular debris. The combinatorial engagement of I2R2 during infections controls DC maturation and shapes their response in terms of cytokine production, activation of natural killer (NK cells and functional polarization of T cells. Several DC subsets exist which express different arrays of I2R2 and are specialized in distinct functions. The study of MCMV infection helped deciphering the physiological roles of DC subsets and their molecular regulation. It allowed the identification and first in vivo studies of mouse plasmacytoid DC which produce high level of interferons-α/β early after infection. Despite its ability to infect DC and dampen their functions, MCMV induces very robust, efficient and long-lasting CD8 T cell responses. Their priming may rely on the unique ability of uninfected XCR1+ DC to cross-present engulfed viral antigens and thus to counter MCMV interference with antigen presentation. A balance appears to have been reached during co-evolution, allowing controlled replication of the virus for horizontal spread without pathological consequences for the immunocompetent host. We will discuss the role of the interplay between the virus and DC in setting this balance, and how advancing this knowledge further could help develop better vaccines against other intracellular

  17. Deciphering the role of DC subsets in MCMV infection to better understand immune protection against viral infections.

    Science.gov (United States)

    Alexandre, Yannick O; Cocita, Clément D; Ghilas, Sonia; Dalod, Marc

    2014-01-01

    Infection of mice with murine cytomegalovirus (MCMV) recapitulates many physiopathological characteristics of human CMV infection and enables studying the interactions between a virus and its natural host. Dendritic cells (DC) are mononuclear phagocytes linking innate and adaptive immunity which are both necessary for MCMV control. DC are critical for the induction of cellular immunity because they are uniquely efficient for the activation of naïve T cells during their first encounter with a pathogen. DC are equipped with a variety of innate immune recognition receptors (I2R2) allowing them to detect pathogens or infections and to engulf molecules, microorganisms or cellular debris. The combinatorial engagement of I2R2 during infections controls DC maturation and shapes their response in terms of cytokine production, activation of natural killer (NK) cells and functional polarization of T cells. Several DC subsets exist which express different arrays of I2R2 and are specialized in distinct functions. The study of MCMV infection helped deciphering the physiological roles of DC subsets and their molecular regulation. It allowed the identification and first in vivo studies of mouse plasmacytoid DC which produce high level of interferons-α/β early after infection. Despite its ability to infect DC and dampen their functions, MCMV induces very robust, efficient and long-lasting CD8 T cell responses. Their priming may rely on the unique ability of uninfected XCR1(+) DC to cross-present engulfed viral antigens and thus to counter MCMV interference with antigen presentation. A balance appears to have been reached during co-evolution, allowing controlled replication of the virus for horizontal spread without pathological consequences for the immunocompetent host. We will discuss the role of the interplay between the virus and DC in setting this balance, and how advancing this knowledge further could help develop better vaccines against other intracellular infectious

  18. One novel quinoxaline derivative as a potent human cyclophilin A inhibitor shows highly inhibitory activity against mouse spleen cell proliferation.

    Science.gov (United States)

    Li, Jian; Chen, Jing; Zhang, Li; Wang, Feng; Gui, Chunshan; Zhang, Li; Qin, Yu; Xu, Qiang; Liu, Hong; Nan, Fajun; Shen, Jingkang; Bai, Donglu; Chen, Kaixian; Shen, Xu; Jiang, Hualiang

    2006-08-15

    Cyclophilin A (CypA) is a ubiquitous cellular enzyme playing critical roles in many biological processes, and its inhibitor has been reported to have potential immunosuppressive activity. In this work, we reported a novel quinoxaline derivative, 2,3-di(furan-2-yl)-6-(3-N,N-diethylcarbamoyl-piperidino)carbonylamino quinoxaline (DC838, 3), which was confirmed to be a potent inhibitor against human CypA. By using the surface plasmon resonance (SPR) and fluorescence titration techniques, the kinetic analysis of CypA/DC838 interaction was quantitatively performed. CypA peptidyl prolyl cis-trans isomerase (PPIase) activity inhibition assay showed that DC838 demonstrated highly CypA PPIase inhibitory activity. In vivo assay results showed that DC838 could inhibit mouse spleen cell proliferation induced by concanavalin A (Con A). Molecular docking simulation further elucidated the specific DC838 binding to CypA at the atomic level. The current work should provide useful information in the discovery of immunosuppressor based on CypA inhibitor.

  19. Whole inactivated avian Influenza H9N2 viruses induce nasal submucosal dendritic cells to sample luminal viruses via transepithelial dendrites and trigger subsequent DC maturation.

    Science.gov (United States)

    Qin, Tao; Yin, Yinyan; Wang, Xiaoqing; Liu, Haofei; Lin, Jian; Yu, Qinghua; Yang, Qian

    2015-03-10

    Nasal mucosal barrier is a key impediment for the absorption of influenza whole inactivated virus (WIV) intranasal vaccine. Yet it is still unclear how WIV cross the epithelial cells (ECs) in nasal cavity. Here, in vitro, a coculture system was well established, consisting of surrogate nasal ECs (Calu-3) and dendritic cells (DCs). After adding H9N2 WIV on the apical side of ECs, we found that submucosal DCs extended their transepithelial dendrites (TEDs) and sampled luminal viruses. However, ECs were not involved in the transepithelial transport of viruses. Subsequently, the phenotypic and functional maturation of DCs were also enhanced, whereas they were attenuated after blocking of TED formation by anti-JAM1 antibody. In vivo, we confirmed that H9N2 WIV were capable of inducing nasal submucosal DCs to sample luminal viruses via TEDs in the nasal passage but not nasal-associated lymphoid tissue (NALT). CD103(+) and CD103(-) DC subsets participated in this process. Of note, chemokine CCL20, released from the H9N2 WIV-induced ECs, played a vital role in DC recruitment and TED formation. Taken together, our findings indicated that TEDs played a critical role in facilitating viral transport across the epithelial barrier, which may guide the design of novel nasal mucosal vaccine strategies.

  20. Identification of transport pathways for citric acid cycle intermediates in the human colon carcinoma cell line, Caco-2.

    Science.gov (United States)

    Weerachayaphorn, Jittima; Pajor, Ana M

    2008-04-01

    Citric acid cycle intermediates are absorbed from the gastrointestinal tract through carrier-mediated mechanisms, although the transport pathways have not been clearly identified. This study examines the transport of citric acid cycle intermediates in the Caco-2 human colon carcinoma cell line, often used as a model of small intestine. Inulin was used as an extracellular volume marker instead of mannitol since the apparent volume measured with mannitol changed with time. The results show that Caco-2 cells contain at least three distinct transporters, including the Na+-dependent di- and tricarboxylate transporters, NaDC1 and NaCT, and one or more sodium-independent pathways, possibly involving organic anion transporters. Succinate transport is mediated mostly by Na+-dependent pathways, predominantly by NaDC1, but with some contribution by NaCT. RT-PCR and functional characteristics verified the expression of these transporters in Caco-2 cells. In contrast, citrate transport in Caco-2 cells occurs by a combination of Na+-independent pathways, possibly mediated by an organic anion transporter, and Na+-dependent mechanisms. The non-metabolizable dicarboxylate, methylsuccinate, is also transported by a combination of Na+-dependent and -independent pathways. In conclusion, we find that multiple pathways are involved in the transport of di- and tricarboxylates by Caco-2 cells. Since many of these pathways are not found in human intestine, this model may be best suited for studying Na+-dependent transport of succinate by NaDC1.

  1. Laser printing of skin cells and human stem cells.

    Science.gov (United States)

    Koch, Lothar; Kuhn, Stefanie; Sorg, Heiko; Gruene, Martin; Schlie, Sabrina; Gaebel, Ralf; Polchow, Bianca; Reimers, Kerstin; Stoelting, Stephanie; Ma, Nan; Vogt, Peter M; Steinhoff, Gustav; Chichkov, Boris

    2010-10-01

    Laser printing based on laser-induced forward transfer (LIFT) is a new biofabrication technique for the arrangement of biological materials or living cells in well-defined patterns. In the current study, skin cell lines (fibroblasts/keratinocytes) and human mesenchymal stem cells (hMSC) were chosen for laser printing experiments due to their high potential in regeneration of human skin and new application possibilities of stem cell therapy. To evaluate the influence of LIFT on the cells, their survival rate, their proliferation and apoptotic activity, and the DNA damages and modifications of their cell surface markers were assessed and statistically evaluated over several days. The cells survived the transfer procedure with a rate of 98%  +/- 1% standard error of the mean (skin cells) and 90%  +/- 10% (hMSC), respectively. All used cell types maintain their ability to proliferate after LIFT. Further, skin cells and hMSC did not show an increase of apoptosis or DNA fragmentation. In addition, the hMSC keep their phenotype as proven by fluorescence activated cell sorting (FACS) analysis. This study demonstrates LIFT as a suitable technique for unharmed computer-controlled positioning of different cell types and a promising tool for future applications in the ex vivo generation of tissue replacements.

  2. Selective susceptibility of human skin antigen presenting cells to productive dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Daniela Cerny

    2014-12-01

    Full Text Available Dengue is a growing global concern with 390 million people infected each year. Dengue virus (DENV is transmitted by mosquitoes, thus host cells in the skin are the first point of contact with the virus. Human skin contains several populations of antigen-presenting cells which could drive the immune response to DENV in vivo: epidermal Langerhans cells (LCs, three populations of dermal dendritic cells (DCs, and macrophages. Using samples of normal human skin we detected productive infection of CD14(+ and CD1c(+ DCs, LCs and dermal macrophages, which was independent of DC-SIGN expression. LCs produced the highest viral titers and were less sensitive to IFN-β. Nanostring gene expression data showed significant up-regulation of IFN-β, STAT-1 and CCL5 upon viral exposure in susceptible DC populations. In mice infected intra-dermally with DENV we detected parallel populations of infected DCs originating from the dermis and migrating to the skin-draining lymph nodes. Therefore dermal DCs may simultaneously facilitate systemic spread of DENV and initiate the adaptive anti-viral immune response.

  3. A resonant dc-dc power converter assembly

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...... and second resonant DC-DC power converters. The first and second inductors are corresponding components of the first and second resonant DC-DC power converters....

  4. Human spleen and red blood cells

    Science.gov (United States)

    Pivkin, Igor; Peng, Zhangli; Karniadakis, George; Buffet, Pierre; Dao, Ming

    2016-11-01

    Spleen plays multiple roles in the human body. Among them is removal of old and altered red blood cells (RBCs), which is done by filtering cells through the endothelial slits, small micron-sized openings. There is currently no experimental technique available that allows us to observe RBC passage through the slits. It was previously noticed that people without a spleen have less deformable red blood cells, indicating that the spleen may play a role in defining the size and shape of red blood cells. We used detailed RBC model implemented within the Dissipative Particle Dynamics (DPD) simulation framework to study the filter function of the spleen. Our results demonstrate that spleen indeed plays major role in defining the size and shape of the healthy human red blood cells.

  5. Rotating cell culture systems for human cell culture: human trophoblast cells as a model.

    Science.gov (United States)

    Zwezdaryk, Kevin J; Warner, Jessica A; Machado, Heather L; Morris, Cindy A; Höner zu Bentrup, Kerstin

    2012-01-18

    The field of human trophoblast research aids in understanding the complex environment established during placentation. Due to the nature of these studies, human in vivo experimentation is impossible. A combination of primary cultures, explant cultures and trophoblast cell lines support our understanding of invasion of the uterine wall and remodeling of uterine spiral arteries by extravillous trophoblast cells (EVTs), which is required for successful establishment of pregnancy. Despite the wealth of knowledge gleaned from such models, it is accepted that in vitro cell culture models using EVT-like cell lines display altered cellular properties when compared to their in vivo counterparts. Cells cultured in the rotating cell culture system (RCCS) display morphological, phenotypic, and functional properties of EVT-like cell lines that more closely mimic differentiating in utero EVTs, with increased expression of genes mediating invasion (e.g. matrix metalloproteinases (MMPs)) and trophoblast differentiation. The Saint Georges Hospital Placental cell Line-4 (SGHPL-4) (kindly donated by Dr. Guy Whitley and Dr. Judith Cartwright) is an EVT-like cell line that was used for testing in the RCCS. The design of the RCCS culture vessel is based on the principle that organs and tissues function in a three-dimensional (3-D) environment. Due to the dynamic culture conditions in the vessel, including conditions of physiologically relevant shear, cells grown in three dimensions form aggregates based on natural cellular affinities and differentiate into organotypic tissue-like assemblies. The maintenance of a fluid orbit provides a low-shear, low-turbulence environment similar to conditions found in vivo. Sedimentation of the cultured cells is countered by adjusting the rotation speed of the RCCS to ensure a constant free-fall of cells. Gas exchange occurs through a permeable hydrophobic membrane located on the back of the bioreactor. Like their parental tissue in vivo, RCCS

  6. Longitudinal changes of peripheral blood DC subsets and regulatory T cells in Chinese chronic HIV-1-infected patients during antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Mei Zhang

    Full Text Available It has been emphasized that chronic generalized immune dysfunction is the leading event in the pathogenesis of HIV infection, in which the contribution of dendritic cells (DCs and regulatory T cells (Tregs should not be underestimated. In current study, we assessed the longitudinal changes of peripheral blood DC subsets and Tregs in chronically asymptomatic treatment-naive HIV-1-infected patients during 60 weeks of antiretroviral therapy (ART, and compared with those in healthy controls and long term non-progressors (LTNPs. Blood samples were collected at week 0, 4, 12, 24, 48 and 60 of treatment to measure the counts of DC subsets and Tregs by flow cytometry and IFN-a plasma levels by ELISA. The counts of myeloid dendritic cells (mDCs increased during ART, reaching similar levels to healthy controls at week 60 post ART but still lower than those of LTNPs. In HIV-1-infected patients, the mDCs counts were directly correlated with CD4 counts during ART. Changes in mDCs at week 8 were positively correlated with the changes in CD4 counts at week 60 post ART. However, the counts and function of plasmacytoid dendritic cells (pDCs remained relatively stable during ART, and similar to those in healthy controls and LTNPs. The percentage of Tregs increased before ART and normalized after ART. Importantly, we found pDCs counts were associated with percentage of Tregs during ART, which may help in understanding of the role of these cells in HIV infection.

  7. Autophagy in human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Thien Tra

    Full Text Available Autophagy (macroautophagy is a degradative process that involves the sequestration of cytosolic material including organelles into double membrane vesicles termed autophagosomes for delivery to the lysosome. Autophagy is essential for preimplantation development of mouse embryos and cavitation of embryoid bodies. The precise roles of autophagy during early human embryonic development, remain however largely uncharacterized. Since human embryonic stem cells constitute a unique model system to study early human embryogenesis we investigated the occurrence of autophagy in human embryonic stem cells. We have, using lentiviral transduction, established multiple human embryonic stem cell lines that stably express GFP-LC3, a fluorescent marker for the autophagosome. Each cell line displays both a normal karyotype and pluripotency as indicated by the presence of cell types representative of the three germlayers in derived teratomas. GFP expression and labelling of autophagosomes is retained after differentiation. Baseline levels of autophagy detected in cultured undifferentiated hESC were increased or decreased in the presence of rapamycin and wortmannin, respectively. Interestingly, autophagy was upregulated in hESCs induced to undergo differentiation by treatment with type I TGF-beta receptor inhibitor SB431542 or removal of MEF secreted maintenance factors. In conclusion we have established hESCs capable of reporting macroautophagy and identify a novel link between autophagy and early differentiation events in hESC.

  8. Identification of the Common Origins of Osteoclasts, Macrophages, and Dendritic Cells in Human Hematopoiesis

    Directory of Open Access Journals (Sweden)

    Yanling Xiao

    2015-06-01

    Full Text Available Osteoclasts (OCs originate from the myeloid cell lineage, but the successive steps in their lineage commitment are ill-defined, especially in humans. To clarify OC origin, we sorted cell populations from pediatric bone marrow (BM by flow cytometry and assessed their differentiation potential in vitro. Within the CD11b−CD34+c-KIT+ BM cell population, OC-differentiation potential was restricted to FLT3+ cells and enriched in an IL3 receptor (Rαhigh subset that constituted less than 0.5% of total BM. These IL3Rαhigh cells also generated macrophages (MΦs and dendritic cells (DCs but lacked granulocyte (GR-differentiation potential, as demonstrated at the clonal level. The IL3Rαlow subset was re-defined as common progenitor of GR, MΦ, OC, and DC (GMODP and gave rise to the IL3Rαhigh subset that was identified as common progenitor of MΦ, OC, and DC (MODP. Unbiased transcriptome analysis of CD11b−CD34+c-KIT+FLT3+ IL3Rαlow and IL3Rαhigh subsets corroborated our definitions of the GMODP and MODP and their developmental relationship.

  9. Identification of the Common Origins of Osteoclasts, Macrophages, and Dendritic Cells in Human Hematopoiesis.

    Science.gov (United States)

    Xiao, Yanling; Zijl, Sebastiaan; Wang, Liqin; de Groot, Daniel C; van Tol, Maarten J; Lankester, Arjan C; Borst, Jannie

    2015-06-01

    Osteoclasts (OCs) originate from the myeloid cell lineage, but the successive steps in their lineage commitment are ill-defined, especially in humans. To clarify OC origin, we sorted cell populations from pediatric bone marrow (BM) by flow cytometry and assessed their differentiation potential in vitro. Within the CD11b(-)CD34(+)c-KIT(+) BM cell population, OC-differentiation potential was restricted to FLT3(+) cells and enriched in an IL3 receptor (R)α(high) subset that constituted less than 0.5% of total BM. These IL3Rα(high) cells also generated macrophages (MΦs) and dendritic cells (DCs) but lacked granulocyte (GR)-differentiation potential, as demonstrated at the clonal level. The IL3Rα(low) subset was re-defined as common progenitor of GR, MΦ, OC, and DC (GMODP) and gave rise to the IL3Rα(high) subset that was identified as common progenitor of MΦ, OC, and DC (MODP). Unbiased transcriptome analysis of CD11b(-)CD34(+)c-KIT(+)FLT3(+) IL3Rα(low) and IL3Rα(high) subsets corroborated our definitions of the GMODP and MODP and their developmental relationship.

  10. The Biomineralization of a Bioactive Glass-Incorporated Light-Curable Pulp Capping Material Using Human Dental Pulp Stem Cells

    OpenAIRE

    Soo-Kyung Jun; Jung-Hwan Lee; Hae-Hyoung Lee

    2017-01-01

    The aim of this study was to investigate the biomineralization of a newly introduced bioactive glass-incorporated light-curable pulp capping material using human dental pulp stem cells (hDPSCs). The product (Bioactive® [BA]) was compared with a conventional calcium hydroxide-incorporated (Dycal [DC]) and a light-curable (Theracal® [TC]) counterpart. Eluates from set specimens were used for investigating the cytotoxicity and biomineralization ability, determined by alkaline phosphatase (ALP) a...

  11. Delivery of granulocyte-macrophage colony-stimulating factor in bioadhesive hydrogel stimulates migration of dendritic cells in models human papillomavirus-associated (pre)neoplastic epithelial lesions

    OpenAIRE

    Hubert, Pascale; Evrard, Brigitte; Maillard, Catherine; Franzen-Detrooz, E.; Delattre, Luc; Foidart, Jean-Michel; Noël, Agnès; Boniver, Jacques; Delvenne, Philippe

    2004-01-01

    Because of the central role of dendritic cells and/or Langerhans cells(DC/LC) in the induction of cellular immune responses, pharmacological agents that modulate the recruitment of these cells might have a clinical interest. The present study was designed to evaluate the capacity of several pharmaceutical formulations to topically deliver granulocyte-macrophage colony-stimulating factor (GM-CSF) on human papillomavirus (HPV)-associated genital (pre)neoplastic lesions. The formulations were ev...

  12. Human embryonic stem cells for neuronal repair.

    Science.gov (United States)

    Ben-Hur, Tamir

    2006-02-01

    Human embryonic stem cells may serve as a potentially endeless source of transplantable cells to treat various neurologic disorders. Accumulating data have shown the therapeutic value of various neural precursor cell types in experimental models of neurologic diseases. Tailoring cell therapy for specific disorders requires the generation of cells that are committed to specific neural lineages. To this end, protocols were recently developed for the derivation of dopaminergic neurons, spinal motor neurons and oligodendrocytes from hESC. These protocols recapitulate normal development in culture conditions. However, a novel concept emerging from these studies is that the beneficial effect of transplanted stem cells is not only via cell replacement in damaged host tissue, but also by trophic and protective effects, as well as by an immunomodulatory effect that down-regulates detrimental brain inflammation.

  13. The human glycoprotein salivary agglutinin inhibits the interaction of dc-sign and langerin with oral micro-organisms

    NARCIS (Netherlands)

    Boks, M.A.; Gunput, S.T.G.; Kosten, I.; Gibbs, S.; van Vliet, S.J.; Ligtenberg, A.J.M.; van Kooyk, Y.

    2016-01-01

    Salivary agglutinin (SAG), also known as gp340 or SALSA, is a glycoprotein encoded by the Deleted in Malignant Brain Tumours 1 gene and is abundantly present in human saliva. SAG aggregates bacteria and viruses, thereby promoting their clearance from the oral cavity. The mucosa lining the oral cavit

  14. Novel agents inhibit human leukemic cells

    Institute of Scientific and Technical Information of China (English)

    Wei-ping YU; Juan LI

    2012-01-01

    Ouabain (OUA) and pyrithione zinc (PZ) have been proved as the potential drugs for treating acute myeloid leukemia (AML).Selected from a screening among 1040 Food and Drug Administration-approved pharmacological agents,both drugs showability to induce apoptosis of the culturing AML cells,exhibiting the poisoning effect on the cells.Studies also reveal the efficiency of the drugs in inhibiting the growth of human AML cells injected into the mice lacking of immunity and killing primary AML cells from the peripheral blood of AML patients[1].

  15. 3 CFR - Guidelines for Human Stem Cell Research

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Guidelines for Human Stem Cell Research Presidential Documents Other Presidential Documents Memorandum of July 30, 2009 Guidelines for Human Stem Cell Research..., scientifically worthy human stem cell research, including human embryonic stem cell research, to the extent...

  16. Charge pump DC-DC converter comprising solid state batteries

    NARCIS (Netherlands)

    Reefman, D.; Roozeboom, F.; Notten, P.H.L.; Klootwijk, J.H.

    2013-01-01

    An electronic device is provided which comprises a DC-DC converter. The DC-DC converter comprises at least one solid-state rechargeable battery (B1, B2) for storing energy for the DC-DC conversion and an output capacitor (C2).

  17. Myristoylation profiling in human cells and zebrafish

    Directory of Open Access Journals (Sweden)

    Malgorzata Broncel

    2015-09-01

    Full Text Available Human cells (HEK 293, HeLa, MCF-7 and zebrafish embryos were metabolically tagged with an alkynyl myristic acid probe, lysed with an SDS buffer and tagged proteomes ligated to multifunctional capture reagents via copper-catalyzed alkyne azide cycloaddition (CuAAC. This allowed for affinity enrichment and high-confidence identification, by delivering direct MS/MS evidence for the modification site, of 87 and 61 co-translationally myristoylated proteins in human cells and zebrafish, respectively. The data have been deposited to ProteomeXchange Consortium (Vizcaíno et al., 2014 Nat. Biotechnol., 32, 223–6 (PXD001863 and PXD001876 and are described in detail in Multifunctional reagents for quantitative proteome-wide analysis of protein modification in human cells and dynamic protein lipidation during vertebrate development׳ by Broncel et al., Angew. Chem. Int. Ed.

  18. Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults.

    Science.gov (United States)

    Szpakowski, Piotr; Biet, Franck; Locht, Camille; Paszkiewicz, Małgorzata; Rudnicka, Wiesława; Druszczyńska, Magdalena; Allain, Fabrice; Fol, Marek; Pestel, Joël; Kowalewicz-Kulbat, Magdalena

    2015-01-01

    Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4(+) T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

  19. Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults

    Directory of Open Access Journals (Sweden)

    Piotr Szpakowski

    2015-01-01

    Full Text Available Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG, the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18 and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4+ T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

  20. Establishment of Human Neural Progenitor Cells from Human Induced Pluripotent Stem Cells with Diverse Tissue Origins

    Science.gov (United States)

    Fukusumi, Hayato; Shofuda, Tomoko; Bamba, Yohei; Yamamoto, Atsuyo; Kanematsu, Daisuke; Handa, Yukako; Okita, Keisuke; Nakamura, Masaya; Yamanaka, Shinya; Okano, Hideyuki; Kanemura, Yonehiro

    2016-01-01

    Human neural progenitor cells (hNPCs) have previously been generated from limited numbers of human induced pluripotent stem cell (hiPSC) clones. Here, 21 hiPSC clones derived from human dermal fibroblasts, cord blood cells, and peripheral blood mononuclear cells were differentiated using two neural induction methods, an embryoid body (EB) formation-based method and an EB formation method using dual SMAD inhibitors (dSMADi). Our results showed that expandable hNPCs could be generated from hiPSC clones with diverse somatic tissue origins. The established hNPCs exhibited a mid/hindbrain-type neural identity and uniform expression of neural progenitor genes. PMID:27212953

  1. Establishment of Human Neural Progenitor Cells from Human Induced Pluripotent Stem Cells with Diverse Tissue Origins.

    Science.gov (United States)

    Fukusumi, Hayato; Shofuda, Tomoko; Bamba, Yohei; Yamamoto, Atsuyo; Kanematsu, Daisuke; Handa, Yukako; Okita, Keisuke; Nakamura, Masaya; Yamanaka, Shinya; Okano, Hideyuki; Kanemura, Yonehiro

    2016-01-01

    Human neural progenitor cells (hNPCs) have previously been generated from limited numbers of human induced pluripotent stem cell (hiPSC) clones. Here, 21 hiPSC clones derived from human dermal fibroblasts, cord blood cells, and peripheral blood mononuclear cells were differentiated using two neural induction methods, an embryoid body (EB) formation-based method and an EB formation method using dual SMAD inhibitors (dSMADi). Our results showed that expandable hNPCs could be generated from hiPSC clones with diverse somatic tissue origins. The established hNPCs exhibited a mid/hindbrain-type neural identity and uniform expression of neural progenitor genes.

  2. DC source assemblies

    Science.gov (United States)

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  3. Uptake of antigen-antibody complexes by human dendritic cells.

    Science.gov (United States)

    Fanger, N A; Guyre, P M; Graziano, R F

    2001-01-01

    Fc receptors specific for IgG (FcγR) potentiate the immune response by facilitating the interaction between myeloid cells and antibody-coated targets (1-3). Monocyte and neutrophil FcyR engagement can lead to the induction of lytic-type mechanisms associated with innate responses. FcyR triggering can also play a key role in adaptive immune responses. For example, FcyR-directed capture and uptake of antigens (Ag) by dendritic cells (DC) results in processing and presentation to naive Ag-specific T cells, leading to their expansion and maturation into effector T-cell populations. This chapter describes methodology currently in use to explore and manipulate antigen-antibody (Ag-Ab) uptake by FcyR expressed on DC.

  4. Plasmodium falciparum Expressing Domain Cassette 5 Type PfEMP1 (DC5-PfEMP1) Bind PECAM1

    DEFF Research Database (Denmark)

    Berger, Sanne S; Turner, Louise; Wang, Christian W

    2013-01-01

    associated with the expression of particular subsets of PfEMP1 molecules. PfEMP1 are grouped into subtypes based on upstream sequences and the presence of semi-conserved PfEMP1 domain compositions named domain cassettes (DCs). Earlier studies have indicated that DC5-containing PfEMP1 (DC5-PfEMP1) are more......, and show that two genetically different parasite lines expressing DC5-PfEMP1 bind PECAM1, and that anti-DC5-specific antibodies inhibit binding of DC5-PfEMP1-expressing parasites to transformed human bone marrow endothelial cells (TrHBMEC). We also show that antibodies against each of the four domains...

  5. Efficient derivation and genetic modifications of human pluripotent stem cells on engineered human feeder cell lines.

    Science.gov (United States)

    Zou, Chunlin; Chou, Bin-Kuan; Dowey, Sarah N; Tsang, Kitman; Huang, Xiaosong; Liu, Cyndi F; Smith, Cory; Yen, Jonathan; Mali, Prashant; Zhang, Yu Alex; Cheng, Linzhao; Ye, Zhaohui

    2012-08-10

    Derivation of pluripotent stem cells (iPSCs) induced from somatic cell types and the subsequent genetic modifications of disease-specific or patient-specific iPSCs are crucial steps in their applications for disease modeling as well as future cell and gene therapies. Conventional procedures of these processes require co-culture with primary mouse embryonic fibroblasts (MEFs) to support self-renewal and clonal growth of human iPSCs as well as embryonic stem cells (ESCs). However, the variability of MEF quality affects the efficiencies of all these steps. Furthermore, animal sourced feeders may hinder the clinical applications of human stem cells. In order to overcome these hurdles, we established immortalized human feeder cell lines by stably expressing human telomerase reverse transcriptase, Wnt3a, and drug resistance genes in adult mesenchymal stem cells. Here, we show that these immortalized human feeders support efficient derivation of virus-free, integration-free human iPSCs and long-term expansion of human iPSCs and ESCs. Moreover, the drug-resistance feature of these feeders also supports nonviral gene transfer and expression at a high efficiency, mediated by piggyBac DNA transposition. Importantly, these human feeders exhibit superior ability over MEFs in supporting homologous recombination-mediated gene targeting in human iPSCs, allowing us to efficiently target a transgene into the AAVS1 safe harbor locus in recently derived integration-free iPSCs. Our results have great implications in disease modeling and translational applications of human iPSCs, as these engineered human cell lines provide a more efficient tool for genetic modifications and a safer alternative for supporting self-renewal of human iPSCs and ESCs.

  6. Human Dendritic Cell Response Signatures Distinguish 1918, Pandemic, and Seasonal H1N1 Influenza Viruses.

    Science.gov (United States)

    Hartmann, Boris M; Thakar, Juilee; Albrecht, Randy A; Avey, Stefan; Zaslavsky, Elena; Marjanovic, Nada; Chikina, Maria; Fribourg, Miguel; Hayot, Fernand; Schmolke, Mirco; Meng, Hailong; Wetmur, James; García-Sastre, Adolfo; Kleinstein, Steven H; Sealfon, Stuart C

    2015-10-01

    Influenza viruses continue to present global threats to human health. Antigenic drift and shift, genetic reassortment, and cross-species transmission generate new strains with differences in epidemiology and clinical severity. We compared the temporal transcriptional responses of human dendritic cells (DC) to infection with two pandemic (A/Brevig Mission/1/1918, A/California/4/2009) and two seasonal (A/New Caledonia/20/1999, A/Texas/36/1991) H1N1 influenza viruses. Strain-specific response differences included stronger activation of NF-κB following infection with A/New Caledonia/20/1999 and a unique cluster of genes expressed following infection with A/Brevig Mission/1/1918. A common antiviral program showing strain-specific timing was identified in the early DC response and found to correspond with reported transcript changes in blood during symptomatic human influenza virus infection. Comparison of the global responses to the seasonal and pandemic strains showed that a dramatic divergence occurred after 4 h, with only the seasonal strains inducing widespread mRNA loss. Continuously evolving influenza viruses present a global threat to human health; however, these host responses display strain-dependent differences that are incompletely understood. Thus, we conducted a detailed comparative study assessing the immune responses of human DC to infection with two pandemic and two seasonal H1N1 influenza strains. We identified in the immune response to viral infection both common and strain-specific features. Among the stain-specific elements were a time shift of the interferon-stimulated gene response, selective induction of NF-κB signaling by one of the seasonal strains, and massive RNA degradation as early as 4 h postinfection by the seasonal, but not the pandemic, viruses. These findings illuminate new aspects of the distinct differences in the immune responses to pandemic and seasonal influenza viruses. Copyright © 2015, American Society for Microbiology. All

  7. [Human pluripotent stem cell and neural differentiation].

    Science.gov (United States)

    Wataya, Takafumi; Muguruma, Keiko; Sasai, Yoshiki

    2008-10-01

    Recovery of lost brain function is an important issue in medical studies because neurons of the central nervous system (CNS) have poor potential for regeneration. Since few CNS diseases can be treated completely by medicines, regenerative therapy by using stem cells should be studied as a new type of therapeutic intervention. The efficacy of cell replacement therapy in Parkinson's disease has been well investigated. Several studies on fetal tissue transplantation have revealed that quantity and purity of transplanted cells are necessary for recovery of symptoms. SFEB (Serum-free floating culture of embryoid body-like aggregates) method is capable of inducing multi-potential CNS progenitors that can be steered to differentiate into region-specific tissues. On the basis of the existing knowledge of embryology, we have succeeded in the generating of various types of neurons such as telencephalic, cerebeller (Purkinje and granule cells), retinal (photoreceptor cells) and hypothalamic neurons. Application of this culture method to human ES (hES) cells is necessary for clinical purpose: however, poor survival of hES cells in SFEB culture might limit the possibility of using these cells for future medical applications. We found that a selective Rho-associated kinase (ROCK) inhibitor, Y-27632, markedly diminished the dissociation-induced apoptosis of hES cells and enabled the cells to form aggregates in SFEB culture. For both mouse and human ES cells, SFEB culture is a favorable method that can generate large amounts of region-specific neurons. However, stem cell-based therapy continues to face several obstacles. It is important that researchers in the basic sciences and clinical medicine should discuss these problems together to overcome both scientific and ethical issues related to stem cells.

  8. Targeting dendritic cells in vivo for cancer therapy

    Directory of Open Access Journals (Sweden)

    Irina eCaminschi

    2012-02-01

    Full Text Available Monoclonal antibodies that recognise cell surface molecules have been used deliver antigenic cargo to dendritic cells (DC for induction of immune responses. The encouraging anti-tumour immunity elicited using this immunisation strategy suggests its suitability for clinical trials. This review discusses the complex network of DC, the functional specialisation of DC-subsets, the immunological outcomes of targeting different DC-subsets and their cell surface receptors, and the requirements for the induction of effective anti-tumour immunity. Finally, we review preclinical experiments and the progress towards targeting human DC in vivo.

  9. T-cell response in human leishmaniasis

    DEFF Research Database (Denmark)

    Kharazmi, A; Kemp, K; Ismail, A

    1999-01-01

    In the present communication we provide evidence for the existence of a Th1/Th2 dichotomy in the T-cell response to Leishmania antigens in human leishmaniasis. Our data suggest that the pattern of IL-4 and IFN-gamma response is polarised in these patients. Lymphocytes from individuals recovered......+. Furthermore, IL-10 plays an important role in the development of post kala azar dermal leishmaniasis (PKDL) from VL. The balance between the parasitic-specific T-cell response plays an important regulatory role in determining the outcome of Leishmania infections in humans....

  10. Characterization of human pluripotent stem cells.

    Science.gov (United States)

    Gokhale, Paul J; Andrews, Peter W

    2013-12-18

    Human pluripotent stem cells (PSCs), whether embryonic stem cells or induced PSCs, offer enormous opportunities for regenerative medicine and other biomedical applications once we have developed the ability to harness their capacity for extensive differentiation. Central to this is our ability to identify and characterize such PSCs, but this is fraught with potential difficulties that arise from a tension between functional definitions of pluripotency and the more convenient use of 'markers', a problem exacerbated by ethical issues, our lack of knowledge of early human embryonic development, and differences from the mouse paradigm.

  11. CLOSTRIDIUM SPORE ATTACHMENT TO HUMAN CELLS

    Energy Technology Data Exchange (ETDEWEB)

    PANESSA-WARREN,B.; TORTORA,G.; WARREN,J.

    1997-08-10

    This paper uses high resolution scanning electron microscopy (SEM) with a LaB6 gun and the newest commercial field emission guns, to obtain high magnification images of intact clostridial spores throughout the activation/germination/outgrowth process. By high resolution SEM, the clostridial exosporial membrane can be seen to produce numerous delicate projections (following activation), that extend from the exosporial surface to a nutritive substrate (agar), or cell surface when anaerobically incubated in the presence of human cells (embryonic fibroblasts and colon carcinoma cells). Magnifications of 20,000 to 200,000Xs at accelerating voltages low enough to minimize or eliminate specimen damage (1--5 kV) have permitted the entire surface of C.sporogenes and C.difficile endospores to be examined during all stages of germination. The relationships between the spore and the agar or human cell surface were also clearly visible.

  12. Human pluripotent stem cells in contemporary medicine

    Directory of Open Access Journals (Sweden)

    S. A. Rodin

    2015-01-01

    Full Text Available Human pluripotent stem cells (hPSCs are capable of indefinite proliferation and can be differentiated into any cell type of the human body. Therefore, they are a promising source of cells for treatment of numerous degenerative diseases and injuries. Pluripotent stem cells are also associated with a number of ethical, safety and technological issues. In this review, we describe various types of hPSCs, safety issues that concern all or some types of hPSCs and methods of clinical-grade hPSC line development. Also, we discuss current and past clinical trials involving hPSCs, their outcomes and future perspectives of hPSC-based therapy. 

  13. Cell pattern in adult human corneal endothelium.

    Directory of Open Access Journals (Sweden)

    Carlos H Wörner

    Full Text Available A review of the current data on the cell density of normal adult human endothelial cells was carried out in order to establish some common parameters appearing in the different considered populations. From the analysis of cell growth patterns, it is inferred that the cell aging rate is similar for each of the different considered populations. Also, the morphology, the cell distribution and the tendency to hexagonallity are studied. The results are consistent with the hypothesis that this phenomenon is analogous with cell behavior in other structures such as dry foams and grains in polycrystalline materials. Therefore, its driving force may be controlled by the surface tension and the mobility of the boundaries.

  14. Merkel cell distribution in the human eyelid

    Directory of Open Access Journals (Sweden)

    C.A. May

    2013-10-01

    Full Text Available Although Merkel cell carcinoma of the eye lid is reported frequently in the literature, only limited information exists about the distribution of Merkel cells in this tissue. Therefore, serial sections of 18 human cadaver eye lids (donors ages ranging between 63 and 97 years were stained for cytokeratin 20 in various planes. The overall appearance of Merkel cells in these samples was low and mainly located in the outer root layer of the cilia hair follicles. Merkel cells were more frequent in the middle, and almost not detectable at the nasal and temporal edges. The localization is in accordance with that of Merkel cell carcinoma, but concerning the scarce appearance within this adulthood group, a specific physiological role of these cells in the eye lid is difficult to establish.

  15. Natural killer cells in human autoimmune disorders

    Science.gov (United States)

    2013-01-01

    Natural killer (NK) cells are innate lymphocytes that play a critical role in early host defense against viruses. Through their cytolytic capacity and generation of cytokines and chemokines, NK cells modulate the activity of other components of the innate and adaptive immune systems and have been implicated in the initiation or maintenance of autoimmune responses. This review focuses on recent research elucidating a potential immunoregulatory role for NK cells in T-cell and B-cell-mediated autoimmune disorders in humans, with a particular focus on multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematous. A better understanding of the contributions of NK cells to the development of autoimmunity may lead to novel therapeutic targets in these diseases. PMID:23856014

  16. Ixazomib suppresses human dendritic cell and modulates murine graft-versus-host disease in a schedule-dependent fashion.

    Science.gov (United States)

    Al-Homsi, Ahmad Samer; Goodyke, Austin; Cole, Kelli; Muilenburg, Marlee; McLane, Michael; Abdel-Mageed, Sarah; Feng, Yuxin

    2017-04-01

    There is an abiding need for innovative approaches to the prevention of graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation (HSCT). Interest in prevention of GvHD by dendritic cell (DC) suppression has re-emerged since the introduction of proteasome inhibitors into clinical practice. Ixazomib is an orally bioavailable proteasome inhibitor with a rapid proteasome dissociation rate. We studied the effects of ixazomib on human DC maturation, viability, and cytokine production in vitro. We also determined the effects of ixazomib in a murine GvHD model. Although ixazomib suppressed naïve human DC maturation, it had only a limited effect on cell viability. Ixazomib decreased pro-inflammatory cytokine production of resting DCs. This effect was diminished or reversed when DCs were pre-stimulated. In vivo, ixazomib administered post-transplantation on days +1 and +4 or days -1, +2, and +5 ameliorated GvHD in comparison to the GvHD group. Although a fraction of mice treated according to the prolonged schedule died abruptly after the day +5 treatment, both schedules resulted in improved overall survival. When we examined the effects of ixazomib on splenic cells and serum cytokines, we found that ixazomib exerted complex schedule-dependent immunomodulatory effects. Our study provides a rationale for the potential use of ixazomib in the prevention of GvHD. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  17. Borrelia burgdorferi Induces TLR2-Mediated Migration of Activated Dendritic Cells in an Ex Vivo Human Skin Model

    Science.gov (United States)

    Wagemakers, Alex; van ‘t Veer, Cornelis; Oei, Anneke; van der Pot, Wouter J.; Ahmed, Kalam; van der Poll, Tom; Geijtenbeek, Teunis B. H.; Hovius, Joppe W. R.

    2016-01-01

    Borrelia burgdorferi is transmitted into the skin of the host where it encounters and interacts with two dendritic cell (DC) subsets; Langerhans cells (LCs) and dermal DCs (DDCs). These cells recognize pathogens via pattern recognition receptors, mature and migrate out of the skin into draining lymph nodes, where they orchestrate adaptive immune responses. In order to investigate the response of skin DCs during the early immunopathogenesis of Lyme borreliosis, we injected B. burgdorferi intradermally into full-thickness human skin and studied the migration of DCs out of the skin, the activation profile and phenotype of migrated cells. We found a significant increase in the migration of LCs and DDCs in response to B. burgdorferi. Notably, migration was prevented by blocking TLR2. DCs migrated from skin inoculated with higher numbers of spirochetes expressed significantly higher levels of CD83 and produced pro-inflammatory cytokines. No difference was observed in the expression of HLA-DR, CD86, CD38, or CCR7. To conclude, we have established an ex vivo human skin model to study DC-B. burgdorferi interactions. Using this model, we have demonstrated that B. burgdorferi-induced DC migration is mediated by TLR2. Our findings underscore the utility of this model as a valuable tool to study immunity to spirochetal infections. PMID:27695100

  18. Human Colon Cancer Cells Cultivated in Space

    Science.gov (United States)

    1995-01-01

    Within five days, bioreactor cultivated human colon cancer cells (shown) grown in Microgravity on the STS-70 mission in 1995, had grown 30 times the volume of the control specimens on Earth. The samples grown in space had a higher level of cellular organization and specialization. Because they more closely resemble tumors found in the body, microgravity grown cell cultures are ideal for research purposes.

  19. E-cadherin interactions are required for Langerhans cell differentiation

    OpenAIRE

    Mayumi, Nobuko; Watanabe, Eri; Norose, Yoshihiko; Watari, Eiji; Kawana, Seiji; Geijtenbeek, Teunis B H; Takahashi, Hidemi

    2012-01-01

    Human skin contains the following two distinct DC subsets: (i) Langerhans cells (LCs), expressing Langerin but not DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), are predominantly localized in the epidermis; and (ii) dermal DCs, expressing DC-SIGN but not Langerin, are observed mainly in the dermis. It is not known whether localization in the epidermis provides cues for LC differentiation. Here, we show that E-cadherin expressed by epidermal keratinocytes (KCs) ...

  20. Quercetin Inhibits Cell Migration and Invasion in Human Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Haifeng Lan

    2017-09-01

    Full Text Available Background/Aims: Osteosarcoma is a malignant tumor associated with high mortality; however, no effective therapies for the disease have been developed. Several studies have focused on elucidating the pathogenesis of osteosarcoma and have aimed to develop novel therapies for the disease. Quercetin is a vital dietary flavonoid that has been shown to have a variety of anticancer effects, as it induces cell cycle arrest, apoptosis, and differentiation and is involved in cell adhesion, metastasis and angiogenesis. Herein, we aimed to investigate the effects of quercetin on osteosarcoma migration and invasion in vitro and in vivo and to explore the molecular mechanisms underlying its effects on osteosarcoma migration and invasion. Methods: Cell viability, cell cycle activity and cell apoptosis were measured using CCK-8 assay and flow cytometry, and cell migration and invasion were evaluated by wound healing and transwell assays, respectively. The mRNA and protein expression levels of several proteins of interest were assessed by real-time quantitative PCR and western blotting, respectively. Moreover, a nude mouse model of human osteosarcoma lung metastasis was established to assess the anti-metastatic effects of quercetin in vivo. Results: We noted no significant differences in cell cycle activity and apoptosis between HOS and MG63 cells and control cells. Treatment with quercetin significantly attenuated cell migration and invasion in HOS and MG63 cells compared with treatment with control medium. Moreover HIF-1α, VEGF, MMP2, and MMP9 mRNA and protein expression levels were significantly downregulated in HOS cells treated with quercetin compared with HOS cells treated with controls. Additionally, treatment with quercetin attenuated metastatic lung tumor formation and growth in the nude mouse model of osteosarcoma compared with treatment with controls. Conclusion: Our findings regarding the inhibitory effects of quercetin on cell migration and

  1. Human Mammary Luminal Epithelial Cells Contain Progenitors to Myoepithelial Cells

    Energy Technology Data Exchange (ETDEWEB)

    Pechoux, Christine; Gudjonsson, Thorarinn; Ronnov-Jessen, Lone; Bissell, Mina J; Petersen, Ole

    1999-02-01

    The origin of the epithelial and myoepithelial cells in the human breast has not been delineated. In this study we have addressed whether luminal epithelial cells and myoepithelial cells are vertically connected, i.e., whether one is the precursor for the other. We used a primary culture assay allowing preservation of basic phenotypic traits of luminal epithelial and myoepithelial cells in culture. The two cell types were then separated immunomagnetically using antibodies directed against lineage-specific cell surface antigens into at best 100% purity. The cellular identity was ascertained by cytochemistry, immunoblotting, and 2-D gel electrophoresis. Luminal epithelial cells were identified by strong expression of cytokeratins 18 and 19 while myoepithelial cells were recognized by expression of vimentin and {alpha}-smooth muscle actin. We used a previously devised culture medium (CDM4) that allows vigorous expansion of proliferative myoepithelial cells and also devised a medium (CDM6) that allowed sufficient expansion of differentiated luminal epithelial cells based on addition of hepatocyte growth factor/scatter factor. The two different culture media supported each lineage for at least five passages without signs of interconversion. We used parallel cultures where we switched culture media, thus testing the ability of each lineage to convert to the other. Whereas the myoepithelial lineage showed no signs of interconversion, a subset of luminal epithelial cells, gradually, but distinctly, converted to myoepithelial cells. We propose that in the mature human breast, it is the luminal epithelial cell compartment that gives rise to myoepithelial cells rather than the other way around.

  2. Genetic Manipulation of Human Embryonic Stem Cells.

    Science.gov (United States)

    Eiges, Rachel

    2016-01-01

    One of the great advantages of embryonic stem (ES) cells over other cell types is their accessibility to genetic manipulation. They can easily undergo genetic modifications while remaining pluripotent, and can be selectively propagated, allowing the clonal expansion of genetically altered cells in culture. Since the first isolation of ES cells in mice, many effective techniques have been developed for gene delivery and manipulation of ES cells. These include transfection, electroporation, and infection protocols, as well as different approaches for inserting, deleting, or changing the expression of genes. These methods proved to be extremely useful in mouse ES cells, for monitoring and directing differentiation, discovering unknown genes, and studying their function, and are now being extensively implemented in human ES cells (HESCs). This chapter describes the different approaches and methodologies that have been applied for the genetic manipulation of HESCs and their applications. Detailed protocols for generating clones of genetically modified HESCs by transfection, electroporation, and infection will be described, with special emphasis on the important technical details that are required for this purpose. All protocols are equally effective in human-induced pluripotent stem (iPS) cells.

  3. A High-Gain Three-Port Power Converter with Fuel Cell, Battery Sources and Stacked Output for Hybrid Electric Vehicles and DC-Microgrids

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2016-03-01

    Full Text Available This paper proposes a novel high-gain three-port power converter with fuel cell (FC, battery sources and stacked output for a hybrid electric vehicle (HEV connected to a dc-microgrid. In the proposed power converter, the load power can be flexibly distributed between the input sources. Moreover, the charging or discharging of the battery storage device can be controlled effectively using the FC source. The proposed converter has several outputs in series to achieve a high-voltage output, which makes it suitable for interfacing with the HEV and dc-microgrid. On the basis of the charging and discharging states of the battery storage device, two power operation modes are defined. The proposed power converter comprises only one boost inductor integrated with a flyback transformer; the boost and flyback circuit output terminals are stacked to increase the output voltage gain and reduce the voltage stress on the power devices. This paper presents the circuit configuration, operating principle, and steady-state analysis of the proposed converter, and experiments conducted on a laboratory prototype are presented to verify its effectiveness.

  4. Rapid detection of dendritic cell and monocyte disorders using CD4 as a lineage marker of the human peripheral blood antigen presenting cell compartment

    Directory of Open Access Journals (Sweden)

    Laura eJardine

    2013-12-01

    Full Text Available Dendritic cells (DCs and monocytes are critical regulators and effectors of innate and adaptive immune responses. Monocyte expansion has been described in many pathological states while monocyte and DC deficiency syndromes are relatively recent additions to the catalogue of human primary immunodeficiency disorders. Clinically applicable screening tests to diagnose and monitor these conditions are lacking. Conventional strategies for identifying human DCs and monocytes have been based on the use of a lineage gate to exclude lymphocytes, thus preventing simultaneous detection of DCs, monocytes and lymphocyte subsets. Here we demonstrate that CD4 is a reliable lineage marker for the human peripheral blood antigen presenting cell compartment that can be used to identify DCs and monocytes in parallel with lymphocytes. Based on this principle, simple modification of a standard lymphocyte phenotyping assay permits simultaneous enumeration of four lymphocyte and five DC/monocyte populations from a single sample. This approach is applicable to clinical samples and facilitates the diagnosis of DC and monocyte disorders in a wide range of clinical settings, including genetic deficiency, neoplasia and inflammation.

  5. Enriched retinal ganglion cells derived from human embryonic stem cells

    Science.gov (United States)

    Gill, Katherine P.; Hung, Sandy S. C.; Sharov, Alexei; Lo, Camden Y.; Needham, Karina; Lidgerwood, Grace E.; Jackson, Stacey; Crombie, Duncan E.; Nayagam, Bryony A.; Cook, Anthony L.; Hewitt, Alex W.; Pébay, Alice; Wong, Raymond C. B.

    2016-01-01

    Optic neuropathies are characterised by a loss of retinal ganglion cells (RGCs) that lead to vision impairment. Development of cell therapy requires a better understanding of the signals that direct stem cells into RGCs. Human embryonic stem cells (hESCs) represent an unlimited cellular source for generation of human RGCs in vitro. In this study, we present a 45-day protocol that utilises magnetic activated cell sorting to generate enriched population of RGCs via stepwise retinal differentiation using hESCs. We performed an extensive characterization of these stem cell-derived RGCs by examining the gene and protein expressions of a panel of neural/RGC markers. Furthermore, whole transcriptome analysis demonstrated similarity of the hESC-derived RGCs to human adult RGCs. The enriched hESC-RGCs possess long axons, functional electrophysiological profiles and axonal transport of mitochondria, suggestive of maturity. In summary, this RGC differentiation protocol can generate an enriched population of functional RGCs from hESCs, allowing future studies on disease modeling of optic neuropathies and development of cell therapies. PMID:27506453

  6. Fcγ receptor antigen targeting potentiates cross-presentation by human blood and lymphoid tissue BDCA-3+ dendritic cells.

    Science.gov (United States)

    Flinsenberg, Thijs W H; Compeer, Ewoud B; Koning, Dan; Klein, Mark; Amelung, Femke J; van Baarle, Debbie; Boelens, Jaap Jan; Boes, Marianne

    2012-12-20

    The reactivation of human cytomegalovirus (HCMV) poses a serious health threat to immune compromised individuals. As a treatment strategy, dendritic cell (DC) vaccination trials are ongoing. Recent work suggests that BDCA-3(+) (CD141(+)) subset DCs may be particularly effective in DC vaccination trials. BDCA-3(+) DCs had however been mostly characterized for their ability to cross-present antigen from necrotic cells. We here describe our study of human BDCA-3(+) DCs in elicitation of HCMV-specific CD8(+) T-cell clones. We show that Fcgamma-receptor (FcγR) antigen targeting facilitates antigen cross-presentation in several DC subsets, including BDCA-3(+) DCs. FcγR antigen targeting stimulates antigen uptake by BDCA-1(+) rather than BDCA-3(+) DCs. Conversely, BDCA-3(+) DCs and not BDCA-1(+) DCs show improved cross-presentation by FcγR targeting, as measured by induced release of IFNγ and TNF by antigen-specific CD8(+) T cells. FcγR-facilitated cross-presentation requires antigen processing in both an acidic endosomal compartment and by the proteasome, and did not induce substantial DC maturation. FcγRII is the most abundantly expressed FcγR on both BDCA-1(+) and BDCA-3(+) DCs. Furthermore we show that BDCA-3(+) DCs express relatively more stimulatory FcγRIIa than inhibitory FcγRIIb in comparison with BDCA-1(+) DCs. These studies support the exploration of FcγR antigen targeting to BDCA-3(+) DCs for human vaccination purposes.

  7. Human ES cells: starting culture from frozen cells.

    Science.gov (United States)

    Trish, Erin; Dimos, John; Eggan, Kevin

    2006-11-09

    Here we demonstrate how our lab begins a HuES human embryonic stem cell line culture from a frozen stock. First, a one to two day old ten cm plate of approximately one (to two) million irradiated mouse embryonic fibroblast feeder cells is rinsed with HuES media to remove residual serum and cell debris, and then HuES media added and left to equilibrate in the cell culture incubator. A frozen vial of cells from long term liquid nitrogen storage or a -80 C freezer is sourced and quickly submerged in a 37 C water bath for quick thawing.